Study of Forging Hammers with Valve Distribution

Forging hammers with valve distribution are found at a number of Soyuz plants. The fact that there are no instructions of any kind in the literature either on the adjustment of these hammers during operation or on their design indicates that they have not been sufficiently studied experimentally. Particularly uncertain are the questions of selecting pressure differences caused by the compression of the working medium (steam, air) in the various sections of the ram stroke, constructing diagrams of valve opening versus handle travel, determining the character of the curves of handle displacement versus ram stroke under different operating regimes of the hammers, and others.

Tests of hammers with valve distributions of the “Eumuco” firm, undertaken by the Central Scientific Research Institute of Mechanical Engineering¹, made it possible to obtain sufficient material illuminating the indicated questions. In addition, on the basis of the hammer tests, technical performance indices of the hammers were determined that corresponded to the conditions existing during the tests. Analysis of the data obtained made it possible to develop a number of measures aimed at improving the technical performance indices of the hammers. Subsequent tests, carried out under modified conditions, showed the correctness of the indicated measures.

The purpose of the present article is—using as an example the investigations of two hammers, a 3-ton hammer of the “Eumuco” firm and a 6-ton hammer—to set forth the investigation procedure and the results obtained.

Descriptive Part

Forging hammers of “Eumuco” with valve distributions (Figs. 1 and 2), of various tonnage, are built on one and the same principle of carrying out air (steam) cutoffs in the working cylinder by means of valves. The hammers can operate both on air and on steam. The operation of the hammers that served as the objects of the present investigation took place exclusively on air. In accordance with this, in the further exposition we take air as the working medium.

The valves are moved manually from a special control handle. Corresponding to the number of air cutoffs in the working cylinder, the total number of working valves on each hammer is four. Thus each valve controls only one definite working process occurring in the cylinder.

Assigning to each valve the corresponding number, we have:

1. Valve for the admission of compressed air into the upper cavity of the cylinder (upper admission).

2. Valve for the discharge of spent air from the upper cavity of the cylinder (upper exhaust).

3. Valve for the admission of compressed air into the lower cavity of the cylinder (lower admission).

4. Valve for exhausting spent air from the lower cavity of the cylinder (lower exhaust).

The valve-shifting mechanism is arranged in such a way that, when the handle moves upward, valves 2 and 3 are raised, while valves 1 and 4 are lowered. When the direction of motion of the handle is reversed, the valves move in the reverse order. The moments of their opening and closing, depending on the positions of the handle, are determined by adjustment of the valve motion. The adjustment is made for each valve separately by changing the amount of lost motion in the handle–valve system.

To facilitate operation of the handle when raising the valves, the pressures acting on the valves are equalized by the preliminary opening of special unloading valves.

When the hammers are not in operation, the control handle is approximately in the middle position; since both inlet valves (1st and 3rd) must then be closed, the piston experiences no pressure from the compressed air, and the tup rests freely on the dies.

When the handle is raised from the middle position, the valves are opened successively: first the upper exhaust valve (2), and then the lower inlet valve (3). Under the action of compressed air on the lower area of the piston, the tup rushes upward. If the handle is left in the upper position throughout the entire upward stroke, the piston will strike the upper spring buffer, since the upper cavity of the cylinder is at that time connected with the atmosphere and the piston experiences no braking action. The energy of such a blow is so great that the bolts of the buffer and cylinder covers may be torn off, and the covers themselves destroyed. To avoid this, the operator must quickly move the handle to a position below the middle one some time before the piston reaches the highest point of its stroke. This seats valves 2 and 3 and opens valves 1 and 4. Under the force of inertia, the tup still continues its upward motion; however, the compressed air above the piston serves as a cushion and prevents the piston from striking the cylinder cover. It should be noted that the moment at which the handle begins to be moved downward must be quite definite. If the moment of lowering the handle is delayed, there will be a blow against the cover; if it is lowered too early, the piston will stop short of the highest point, and thus the hammer will operate without full use of the stroke.

To obtain blows of maximum energy, the handle should be held in the lower position throughout the entire time of the downward stroke of the tup, and only after the blow should the handle be raised to obtain the next idle upward stroke. In the interests of using the full power of the hammer, the raising of the handle should be carried out immediately after the blow. If the handle is held in the lower position, the tup will for some time carry out the cycle of the so-called “pressing.” Operation of the hammer according to such a cycle, while giving no appreciable advantages in relation to the technological process, slows the rate of operation of the hammer. If the handle is raised before the blow and the valves of the lower inlet (3) and upper exhaust (2) are opened during the downward stroke of the tup—before the blow—the latter is weakened by the presence of a lower air cushion and by the shutting off of the upper air. In practice, such a mode of hammer operation (with a lower cushion) is resorted to in those cases when light but frequent blows are required. Indeed, in this case, by the moment when the tup begins to rise, the lower cavity of the working cylinder is already filled with compressed air, and the time of “pressing” is practically equal to zero. The energy of such blows decreases to the greater extent, the earlier during the downward stroke of the piston the control handle was raised.

Thus, with sufficient experience on the part of the operator, a properly adjusted hammer can meet the most varied requirements imposed on it by the technological conditions of operation. The position of “holding the ram suspended” is created by slowly and carefully raising the handle from the middle position to the moment corresponding to the beginning of the ram’s rise. In this way there will occur a slow “pulling up” of the ram upward under a slight pressure until the piston stops against the shock-absorber pin.

The structural design of the 3-ton and 6-ton types of valve hammers is different. The former are arch-type hammers with a cast frame. The latter are bridge-type hammers with a riveted frame. The general view of the 6-ton hammers of the Eumuco firm is shown in Figs. 1 and 2. The principal distinguishing

Fig. 1.

feature of each type of hammer is also the arrangement of the working valves, which in turn causes changes in the design of the valve chest and in the arrangement of the valve-travel mechanism.

The valve chest of the 3-ton hammer with valves is shown in Fig. 3. Both exhaust valves (2) and (4) are located directly beneath the corresponding inlet valves (1) and (3). Each valve has 10 ports arranged around the circumference of the bushings. The ports are surrounded on the outside by annular spaces. The annular spaces of the inlet valves (upper pair) are connected to one another by a single intermediate channel, permanently communicating with the compressed main air line. The annular spaces of the exhaust valves (lower pair), connected with one another by

of their own channel, constantly communicating with the atmosphere. The spaces between the admission and exhaust valves are directly connected with channels communicating with the corresponding cavities of the cylinder (the spaces between valves 1 and 2—with the upper cavity, and the spaces between valves 3 and 4—with the lower cavity of the cylinder).

Fig. 2.

Besides this, in this design the arrangement of the valves ensures sufficient compactness of the valve chest.

Fig. 3.

Let us consider the mechanism for shifting the valves of a 3-ton hammer. When the control handle is moved, the vertical rod connected with it sets into rotary motion the crosshead shown in the diagrams (Fig. 4). The rod from the handle is attached to the left-hand part of the crosshead crossbar.

Fig. 4.

On the right-hand part of the crossbar is suspended a weight that balances the mechanism. When the crosshead rotates, the bolts \(b\), hinge-mounted to its vertical part (Fig. 5), are displaced. The bronze bushings \(a\), seated on the bolt threads and provided with collars, will slide freely in the holes of the valve tappets \(e\) until their collars touch the end face of the tappets. Since the latter are hinge-fastened between two strips forming the levers \(d\), then with further displace-

when the bolts are shifted, rotation of levers \(d\) and of the shafts \(O\), keyed to them, will take place. The shafts \(O\) rotate in bearings and enter

View along arrow A.

Fig. 5.

into the valve chest. The pins, eccentrically located at the ends of the shafts, are connected with the axes of the valves. In view of the fact that the motion of the shaft pins takes place along a circumference, while the valves must move vertically, in order to make possible the free sliding of the pins in the horizontal direction, the corresponding sockets for them have the form of horizontal slots. It is clear that the greater the value of the clearance \(c\) between the collar of the bushing and the end plane of the split block, i.e., the greater the lost motion of the handle–valve system, the later the lifting of the given valve will begin, and the earlier, during the reverse motion of the handle, it will seat in the socket.

Thus the adjustment of each valve is carried out by changing the dimensions \(c\), by screwing in or unscrewing the bushings \(a\), seated on the threaded bolts \(b\). The fixing of the adjustment is most conveniently performed according to dimension \(u\).

The design of the valve chest of the 6-ton hammer (Fig. 6) provides for the arrangement of all 4 valves on one horizontal line.

Consideration of the diagrams (Fig. 7) gives, without special explanations, a sufficiently clear idea of the motion of air in the valves of the valve chest. The upper diagram corresponds to the position of the handle upward, and the lower one—to downward. The change in the arrangement of the valves, in comparison with the 3-ton hammer, necessitated 2 additional passages, which cannot be considered

a negative factor. Indeed, the compressed air entering the lower cavity of the cylinder, during the upward stroke of the ram, must first

Fig. 6.

Valve chest of a 6-ton hammer.

1. Upper inlet valve.
2. Upper exhaust valve.
3. Lower inlet valve.
4. Lower exhaust valve.

Section along \(CD\).
Section \(EF\).

pass through an extra channel with a local resistance in the form of a turn. The exhaust air leaving the upper cavity of the cylinder at this time must overcome the same additional resistance. Both of these phenomena entail a slowing of the ram’s rise and, consequently, a reduction in the number of blows of the hammer per unit time. As a positive feature inherent in the valve arrangement adopted in 6-ton hammers, one should note the simplicity of the mechanism for moving the valves (Fig. 8).

Adjustment of the valves (Fig. 9) is carried out here by changing the dimensions \(u\) by screwing in or unscrewing the valve tappets seated in bushings \(a\). The magnitudes of the dead strokes of the handle–valve system, in turn, depend on the dimensions \(u\). Unlike the 3-ton hammer, changing the dimensions \(u\) here precisely expresses the magnitudes of the changes in valve travel. This circumstance considerably simplifies and facilitates adjustment of the hammer.

Fig. 7.

![Diagram with valve positions and handle positions.]

Opening — 44 mm
Clearance — \(C = 0\)

Opening — 31 mm
Clearance — \(C = 0\)

Opening — 0
Clearance — \(C = 14\) mm

Opening — 0
Clearance — \(C = 34\) mm

Handle position

Opening — 0
Clearance — \(C = 69\) mm

Opening — 0
Clearance — \(C = 34\) mm

Opening — 50 mm
Clearance — \(C = 0\)

Opening — 31 mm
Clearance — \(C = 0\)

Handle position

Opening — 12 mm
Clearance — \(C = 0\)

Opening — 0
Clearance — \(C = 0\)

Opening — 13 mm
Clearance — \(C = 0\)

Opening — 0
Clearance — \(C = 0\)

Handle position

Hammer No. 2, “EUMUO,” 6 t.
Diagram of the principal positions of the valves
(pressure hammers, TsGZ)
and of the mechanism for moving them:

1 — upper admission valve
2 — upper exhaust valve
3 — lower admission valve
4 — lower exhaust valve

Fig. 8.

![Diagram of 6-ton hammer mechanism.]

Hammer, 6 tons

Fig. 9.

RESEARCH PART.

I. Determination of the Existing Condition of the Hammers.

The methods for carrying out all necessary measurements and calculations for determining the “existing condition” of the hammers, for the convenience of systematic monitoring of hammer operation by the shop technical personnel, are set forth in the form of special protocols¹.

From these protocols the parameters of the hammers and their kinematic characteristics are determined.

1. Principal parameters (protocols No. 1).

a) Weight of the falling parts (piston, rod, ram, tup)—\(G_{kg}\)

b) Values of the maximum design stroke of the ram—\(H_{max}\); of the maximum actual stroke of the ram—\(H_o\)

c) Working areas of the piston: upper \(F \text{ cm}^2\), lower—\(\alpha F \text{ cm}^2\)

d) Values of the actual harmful spaces:

\[ \text{upper } Y_o = V_o + v_o + v_{ok}\ \text{cm}^3 \]

\[ \text{lower } Y_u = V_{2h\delta} + v_u + v_{uk}\ \text{cm}^3, \]

where \(\overline{V}_o\) and \(V_{2h\delta}\) are, respectively, the volumes of the upper and lower harmful spaces directly in the cylinder cavity;

\(v_o\) and \(v_u\) are, respectively, the volumes of the upper and lower harmful spaces in the cylinder passages;

\(v_{ok}\) and \(v_{uk}\) are, respectively, the volumes of the upper and lower harmful spaces in the valve chest.

The parameter \(G\)—the weight of the falling parts of the hammer—is determined by weighing with a dynamometer, followed by comparison with the results of calculations according to drawing data. The remaining parameters are determined by measurement and the corresponding calculations.

Determination of \(V_{2h\delta}\) is carried out by measuring the distances \((A)\) from the lower plane of the ram to the upper plane of the tup holder, with the piston lowered onto the lower cover (Fig. 10)¹.

The dimension \(A\), determined in this way, also has independent significance as a factor correcting the correctness of the established height of the tups. Indeed, the total height of the tups \(2h_\delta\) must exceed the dimension \(A\) by the amount necessary to ensure the normal height of the lower harmful space.

The dimensions \(J\) and \(B\) are measured directly; the dimension \(k\) is determined by measuring the auxiliary dimensions \(\gamma\), \(\varepsilon\), and the dimension \(e\), with subsequent calculation from the expressions:

\[ k = \gamma + \varepsilon - e\ \text{mm} \quad \text{— for a 3 t hammer} \]

\[ k = \gamma + \varepsilon - e + 170\ \text{mm} \quad \text{— for a 6 t hammer}. \]

All the dimensions necessary for determining the parameters are brought together in Table 1 and, according to the technique of their measurement, are divided into four groups.

The first group of dimensions (from \(B\) to \(\varepsilon\) inclusive) can be obtained without any preliminary disassembly of the hammer.

The second group of dimensions (from \(t\) to \(\gamma\) inclusive) can be obtained only with the upper cover removed and with the tups present.

The third group of dimensions \((H_2\) and \(A)\) is determined in the same way as the second group of dimensions, but with the piston lowered onto the lower cylinder cover.

The fourth group of dimensions (from \(l\) to \(l_u\)), owing to the difficulty of measuring them on the actual machine, is determined only from the cylinder drawings.

The results of the calculations of the principal hammer parameters are given below.

The results obtained are collected in Table 2.

2. Kinematic Characteristics of the Distributing Mechanisms of Hammers (records No. 2)\(^1\)

The kinematic characteristics of hammers are determined by:

1. The law of displacement of the valves as a function of the position of the control handle on the sector.

2. The positions of the control handle corresponding to the instants at which the valves seat.

In turn, both the law of displacement and the instants of valve seating depend on:

a) the relative arrangement and dimensions of the links of the distributing mechanism;

b) the dimensions fixing the adjustment of the hammer;

c) the magnitudes of clearances and lost motions in the links of the distributing mechanism.

For rapid determination of all the indicated dependencies, records No. 2 were compiled. The records give the procedure for determining the data needed to fill in Tables 1, 2, and 3 and to construct the graph of valve displacement as a function of handle position.

Thus, for example, it is indicated that, in order to determine the relative arrangement of the links of the distributing mechanism, link \(d\) must be set in the horizontal position and the position of the control handle on the sector must then be marked. In testing the 3 t hammer, the horizontal position of link \(d\) (Fig. 11) was set by means of a spirit level, while in tests of the 6 t hammers it was set by equality of the heights \(X\) of the cups projecting from the cover of the valve-box stand (Fig. 20). As already indicated earlier, the arrangement of the links of the distributing mechanism must be fixed relative to definite positions of the control handle on the sector. For this purpose it is necessary to mark out the full travel of the handle (Figs. 11 and 17)\(^1\).

The relative arrangement of the links of the distributing mechanism depends on the linear dimensions of the individual links of the mechanism. All dimensions that affect the relative arrangement of the links, but do not change with different adjustments of the hammer operation, are collected in Table 1 (Figs. 11 and 17). The dimensions whose change determines a given adjustment of the hammer operation are collected in Table 2. Finally, Table 3 contains the dimensions affecting the operation of each valve (Figs. 12 and 18)\(^1\).

The law of valve displacement as a function of the positions of the control handle is established experimentally, by recording the displacements of each valve at different positions of the handle on the sector.

Measurement of the indicated valve displacements, denoted in Tables 4 and 4a by \(y\), was performed with the upper covers of the valve box removed.

It should be noted, however, that the data of Table 4 do not yet give an idea of the exact position of the control handle at the instants when the working and exhaust valves seat. Determination of the indicated handle positions reduces to finding, on the sector, those positions at which the working and exhaust valves lift and seat. The results of the determinations are collected in Table 5.

\(^1\) See the appendix.

In these tables it is assumed that:

the dimensions \(t_1\) are measured at the moments when the beginning of the lifting of the exhaust valves is observed (the working valves are seated);

the dimensions \(t_2\)—at the moments when the exhaust valves are raised to the stop, while the working valves are still seated;

the dimensions \(y_2\)—at the moments when the beginning of the lifting of the working valves is observed;

the dimensions \(t_0\)—at the moments when the exhaust valves are seated;

the dimensions \(y_1\)—at the moments when the working valves are seated.

The magnitudes of the strokes \(\lambda\) of the exhaust valves are determined as the differences of the readings of the measurements \(t_0\) and \(t_2\).

The displacements of the valves, determined in the manner described above, and the relative positions of the handle at the moments when they seat, include the influence of lost motions (clearances) in the distributing mechanisms. These lost motions reduce the magnitudes of valve lift, and a point may occur in the operation of the distributing mechanisms when, upon movement of the control handle, the valves will not lift at all. Hence follows the necessity of checking the magnitudes of the lost motions. Determining the magnitudes of the lost motions in the distributing mechanisms from the control handle to link \(d\) (Figs. 11 and 17) presents no difficulty; determining the lost motions in the links from link \(d\) to the working valves, however, requires a number of additional operations. One of these operations is the measurement of the dimensions \(X\) (the obtained dimensions \(X\) are entered in Table 6).

On a \(3\,t\) hammer, the reference for the dimensions \(X\) is made between verticals, one of which passes through the axis of rotation of the levers, and the other through the center of the lower opening of the lever (Fig. 14). The direction of the verticals is established with the aid of a straightedge and a plumb line.

The vertical displacements of the valves corresponding to the obtained dimensions \(X\) are determined graphically, since the angle \(\alpha\) (Fig. 12) is known for each valve. For \(6\,t\) hammers the dimensions \(X\) are the heights of the cups protruding from the cover of the pedestal of the valve-box tumblers (Fig. 20). Owing to the coincidence of the direction of displacement of the cups with the directions of displacement of the valves, it is natural that, in order to determine the magnitudes of valve displacement, no recalculations are required in this case.

From the data of Tables 4, 5, and 6, graphs of valve displacement as a function of the position of the control handle are constructed. We give a description of the construction of these graphs.

For a \(3\,t\) hammer the graph (Fig. 15) is constructed as follows. A number of verticals are drawn at equal distances from one another; the number of intervals between them corresponds to the number of sector divisions contained between the extreme positions of the control handle. On the grid thus drawn, an arbitrary horizontal line is drawn, and from it upward are laid off the magnitudes of the strokes \((\lambda)\) of the exhaust valves. Since the magnitudes of the strokes are approximately the same, one common horizontal line is drawn, on which the graph of valve opening is constructed. From this line, along the corresponding ordinates, the magnitudes of opening of the working valves from Tables 4 and 6 are laid off upward.

The curves constructed according to Table 4 and represented on the graph by solid lines give the graph of the actual openings of the valves. The curves constructed in accordance with Table 6 and shown on the graph by a dotted line give an idea of the magnitudes of opening of the working valves in the case of absence of lost motions in the distributing mechanism.

For \(6\,t\) hammers the construction of the graphs (Fig. 21) is carried out as follows. First, on the basis of the considerations given above, [[unclear: text continues on next page]]

a row of verticals. Approximately through the middle of the grid thus drawn an arbitrary horizontal line is drawn, from which the clearances \(T\) (the differences between the travels of the cups and the travels of the valves, found from Tables 4 and 6), formed between the tappets and the valves at the extreme positions on the sector of the control handle, are plotted downward along the verticals.

The points \(a, б, в, г\) obtained in this way are the initial points for constructing, from Table 6, the curves of cup displacement. To facilitate the construction of these curves, from the points \(a, б, в, г\) the corresponding initial (minimum) values \(X\) from Table 6 are plotted vertically downward. Through the points thus found, \(a', б', в', г'\), horizontal lines are drawn, parallel to the line drawn earlier. From these lines, along the corresponding verticals, the values \(X\) from Table 6 are plotted upward.

To check the correctness of the curves obtained, as well as their accuracy, the curves of valve opening are constructed according to Table 4.

II. Taking and Processing Indicator Diagrams

The purpose of taking indicator diagrams was to give a complete representation of the character of the pressure changes in the lower and upper cavities of the cylinder, and also above the upper admission valve during the motion of the hammer piston. To accomplish this, the following arrangement of indicators was made.

In the upper and lower cavities of the cylinder, “Maihak” indicators were installed with limiting spring pressures of \(8\ \mathrm{kg}\) and a pressure scale of \(1\ \mathrm{kg}/\mathrm{cm}^2 = 6\ \mathrm{mm}\). On the cover of the upper admission valve a “Maihak” indicator was installed with a limiting spring pressure of \(16\ \mathrm{kg}\) and a pressure scale of \(1\ \mathrm{kg}/\mathrm{cm}^2 = 3\ \mathrm{mm}\). The drums of the installed indicators were connected with the motion of the ram by means of a cord, one of the ends of which was fastened to the wedge securing the upper die in the ram. The motion of the ram was transmitted to the drums through a travel reducer; the latter provided the following ratios of the ram travel to the displacement of a point on the lateral surface of the indicator drums:

\[ \alpha=\frac{D+\delta}{d+\delta}=\frac{130+1}{7+1}=16.375, \]

where \(D\) is the diameter of the drum of the travel reducer,
\(d\) is the diameter of the roller,
\(\delta\) is the diameter of the cord.

1. Determination of the Character of the Displacement of the Control Handle over the Ram Stroke

The forging hammers under investigation, “Eumuco,” are equipped with manual controls. The mechanism for moving the valves here is not mechanically connected with the motion of the ram, as is the case in stamping hammers with slide-valve distribution. As a consequence, establishing the character of the change in the working air processes in the cylinder can be carried out if the character of the displacement of the control handle over the ram stroke is known. The character of the displacement of the control handle as a function of the ram stroke was established by means of specially designed devices (Figs. 22 and 23). These devices, which were ordinary three-link mechanisms, ensured the transmission and fixing of the vertical displacements of the control handle. The vertical displacements of the extreme upper link of the device were marked in pencil on the paper of an indicator drum mounted on...

Fig. 23.

• Engagement for locking the handle along the travel of the ram
• Indicator drum
• Ellis hammer
• Compressed air
• Locknut
• Hinge
• Hinge
• Lever
• Center of rotation of the lever

• Compressed air

• Ellis ram, 0.5 t

• Compressed air
• Hinge
• Center of rotation of the lever
• Lever

• Engagement for locking the handle along the travel of the ram
• Indicator drum
• Ellis ram, 0.5 t
• Tensioning device
• Compressed air
• Hinge
• Wedge handle
• Hinge
• Center of rotation of the lever
• Air
• Vertical adjustment of the wedge

… the upper inlet valve opens. In order to know the character and magnitude of these displacements, it is necessary to determine them experimentally for each test (with the air-line valve closed). For this purpose, the control handle must be placed in its lowest position and the corresponding position of the pencil marked on the indicator paper. Then, while gradually raising the control handle, the positions of the pencil are marked which it assumes at the moments when the upper edge of the control handle coincides with the divisions marked on the sector. The same must also be done when lowering the handle from its uppermost position. The marks obtained must coincide with the previously obtained marks.

In testing the 3-ton hammer, the device was attached to the lever of the crosshead at a distance of 38 mm from the center of oscillation of the crosshead (Fig. 22), thereby providing a height of the recorded diagram on the indicator of 20 mm.

In testing the 6-ton hammer, the device was attached to the control lever (Fig. 23) at a distance of 60 mm from the center of rotation of the rocker, thereby providing a height of the recorded diagram of 25 mm. It should be noted, however, that the locations for attaching the devices were chosen in this way solely for reasons of the possibility of placing on one indicator drum, installed above the inlet valve, two diagrams—the diagram of displacement of the control handle and the diagram of changes in pressure above the upper inlet valve along the piston stroke.

2. Determination of the Character of the Pressure Curve above the Upper Inlet Valve

For this purpose, on the indicator installed on the cover of valve 1 of the upper inlet, whose piston, with the cock open, was under the pressure of the air in the space above the valve, a pressure curve was recorded, giving an idea of the magnitude of the forces pressing the valve against the seat and of the magnitude of the forces required to lift it.

No curve of pressure changes above valve 3 of the lower inlet was taken, since it may be assumed that the character of this curve, given identical lateral clearances in the valve and the same arrangement of the unloading valve, is identical with the pressure curve in the space above the upper inlet valve.

3. Determination of the Character of the Working Processes of the Air in the Cylinder along the Piston Stroke

The determination is reduced to finding on the indicator diagrams the cut-off points, i.e., the points corresponding to the moments of lifting and seating of the working valves in the course of the piston motion. The method for finding the cut-off points is as follows.

In the upper part of the sheet (Fig. 26), on which all the indicator diagrams subsequently obtained for the given hammer setting will be plotted, a scale of displacements of the control handle is drawn. Then, on the scale thus drawn, the valve-opening graphs (according to protocols No. 2) and the diagrams of displacement of the control handle along the ram stroke are constructed.

After this, below the displacement diagram of the handle, the diagram of air pressures above valve 1 of the upper inlet and the indicator diagrams of the upper and lower cavities of the cylinder are plotted.

Next, after all the indicated constructions have been made, the finding of the cut-off points presents no difficulty. For example, in order to determine from what moment of the upward stroke of the piston valve 1 of the upper inlet begins to open, it is sufficient from the opening graph of this valve to take …

horizontally to the point corresponding to the moment of its opening on the handle-displacement diagram (on the branch corresponding to the downward motion of the handle). The point of intersection of the diagram thus found is projected vertically downward onto the lower branch of the indicator diagram of the upper cylinder cavity. The point obtained in this way indicates the beginning of the upper air admission during the upward stroke of the ram.

In the same way, on the basis of the opening diagram of valve 3, one can find on the indicator diagram of the lower cavity the point of the beginning of the lower air admission, etc.

4. Determination of Air Consumption

The air consumption was calculated from the indicator diagrams. For this purpose, cutoff points were marked on these diagrams, determining the magnitudes of the periods of the air working process and the air pressures at these points.

\(p_1\)—at the end of the filling period below the piston during upward motion.
\(p_2\)—at the end of the exhaust period below the piston during downward motion.
\(p_3\)—at the end of the filling period above the piston during downward motion.
\(p_4\)—at the end of the exhaust period above the piston during upward motion.

The values of the indicated air pressures are given in Tables \(a\) for each test. In the same tables are given the specific volumes \(v\) of the air under the indicated conditions; these volumes were calculated from the change of air pressure in the hammer cylinder according to the law

\[ p_0 v_0^k = p_1 v_1^k = p_2 v_2^k = p_3 v_3^k = p_4 v_4^k, \]

where \(p_0\) is the air pressure in the main line,

\[ k = 1.41 \]

is the adiabatic exponent.

The indicated volume of main-line air was determined from the formula

\[ 10\,000\, P V = G R T. \]

\[ v_0 = \frac{V}{G} = \frac{R \cdot T}{10\,000\, p_0}\ \text{m}^3/\text{kg}, \]

where \(R\) is the gas constant of air, equal to 29.27,
\(T\) is the absolute temperature of the air, \(T = 273^\circ + t\),
\(p_0\) is the pressure in absolute atmospheres.

In order to determine the weight flow rate of air, it is first necessary to calculate its volumetric flow rate.

The volume below the piston at the end of the filling period \(\gamma H_m\), at the instant of cutoff during upward motion of the piston, is equal to:

\[ V_1 = (\varphi_u + \gamma) H_m \alpha F\ \text{cm}^3, \]

where \(\varphi_u H_m\) is the lower reduced harmful space.

The volume below the piston at the end of the exhaust period \((1 - \gamma_1 - \beta_1)H_m\), during downward motion of the piston, is equal to

\[ V_2 = (\varphi_u + \gamma_1 + \beta_1) H_m \alpha F\ \text{cm}^3. \]

The volume above the piston at the end of the filling period during downward motion is

\[ V_3 = (\varphi_o + \gamma') H_m F\ \text{cm}^3, \]

where \(\varphi_o\) is the upper reduced harmful space.

The volume above the piston at the end of the exhaust period \([1 - \gamma_1' - \beta_1']H_m\), during upward motion, is equal to:

\[ V_4 = (\varphi_o + \gamma_1' + \beta_1') H_m F\ \text{cm}^3. \]

Below is an illustration of the adopted letter designations (Fig. 24).

Fig. 24.

On the basis of the processed indicator diagrams of each test, Table 6 is compiled, containing the quantities necessary for determining the volumetric air consumption.

The weight consumption of lower air for one double stroke of the hammer tup is determined as follows:

\[ Q_{\mathrm{н}}=\frac{V_1}{v_1}-\frac{V_2}{v_2}=Q_1-Q_2\ \text{kg} \]

where \(V_1\) and \(V_2\) are the corresponding volumes occupied by the air,
\(v_1\) and \(v_2\) are the specific volumes of the air.

The weight consumption of upper air for one double stroke of the hammer tup is

\[ Q_{\mathrm{в}}=\frac{V_3}{v_3}-\frac{V_4}{v_4}=Q_3-Q_4\ \text{kg}. \]

The total weight consumption is

\[ Q=Q_{\mathrm{н}}+Q_{\mathrm{в}}\ \text{kg}. \]

Next, the total volumetric air consumption \((V)\) is determined at a pressure of 760 mm of mercury and \(t=20^\circ\mathrm{C}\) from the following relation:

\[ V=\frac{Q}{v}\ \text{m}^3, \]

where

\[ v=1.3-0.004\,t\ \text{kg/m}^3. \]

And, finally, the air consumption per 1 kgm of impact energy is determined.

The results of the calculations are brought together in Table 8, and on the basis of the latter graphs of the volumetric and specific air consumptions are constructed.

5. Determination of the Average Friction Force.

In view of the fact that the weight of the falling parts of the hammer is precisely determined by dynamometer, the average value of the friction forces during the upward stroke of the piston can be determined from the indicator diagrams with the smallest stroke.

Indeed, the indicated work \(L_{in}\) of the air in the lower cavity, during the upward stroke of the piston (there is no blow against the safety device), is expended in overcoming the work of resistance of the upper air \(L_{iв}\), the work of resistance due to gravity \(L_G\), and that due to the friction force \(L_R\):

\[ L_{in}=L_{iв}+L_G+L_R \]

\[ L_{in}-L_{iв}=L_G+L_R \]

Here the difference \(L_{in}-L_{iв}\) represents the free work going exclusively to overcoming the work of resistance due to gravity and the friction force.

These forces act simultaneously over the entire length of the piston stroke; consequently, the equation of work may be represented in the form—

\[ L_{in}-L_{iв}=(G+R)H_m \]

\[ G+R=\frac{L_{in}-L_{iв}}{H_m}, \]

where

\[ \frac{L_{in}-L_{iв}}{H_m}=P_{cв}\text{—free indicated force.} \]

whence

\[ R=P_{cв}-G \ \text{kg}. \]

For determining the friction \((R)\), the processing of the indicator diagrams is carried out in the following order:

a) From the indicator diagram there is determined:
the actual piston stroke \(H_m\)

\[ H_m=0.001 \cdot l \cdot \alpha \ \text{m} \]

where \(l\) is the length of the indicator diagram in mm,
\(\alpha\) is the length scale, equal to 16.375.

b) The areas of the indicator diagrams of the lower and upper cavities of the cylinder, \(\Phi_n\) and \(\Phi_в\), corresponding to the indicated works during the upward stroke of the piston, are planimetered; namely, the areas located between the atmospheric line and the upper branch on the diagram of the lower cavity, and between the atmospheric line and the lower branch on the diagram of the upper cavity.

c) The mean heights of the diagrams of the upper and lower cavities \(h_в\) and \(h_n\) are determined:

\[ h_в=\frac{\Phi_в}{l}\ \text{mm}; \qquad h_n=\frac{\Phi_n}{l}\ \text{mm}. \]

d) The mean indicated pressures in the upper \(p_в\) and lower \(p_n\) cavities are determined:

\[ p_в=\frac{h_в}{m}\ \text{kg/cm}^2; \qquad p_n=\frac{h_n}{m}\ \text{kg/cm}^2, \]

where \(m\) is the scale of the indicator spring, equal to \(6\ \mathrm{mm/kg}\).

d) The mean indicator forces in the upper \(P_v\) and lower \(P_n\) cavities are determined:

\[ P_v = p_v F\ \mathrm{kg}; \qquad P_n = p_n \alpha F\ \mathrm{kg}. \]

e) The free force is determined:

\[ P_{sv} = P_n - P_v\ \mathrm{kg}. \]

f) The mean friction force is determined:

\[ R = P_{sv} - G\ \mathrm{kg}. \]

The mean friction force during the upward stroke of the piston may also be determined from the expression

\[ R = -\frac{F}{l \cdot m}\left(\Phi_v - \alpha \Phi_n\right)\ \mathrm{kg}. \]

The results of the determinations are summarized in Table 2.

6. Determination of the Ram Velocity and Impact Energy

The determination of the velocity and impact energy from the indicator diagrams consists of the following.

First, by planimetry, the areas of the diagrams of the upper and lower air spaces corresponding to the downward stroke of the piston are determined; namely, the areas located between the atmospheric line and the upper branch on the diagram of the upper cavity, and between the atmospheric line and the lower branch on the diagram of the lower cavity.

Next, by the method given in the section on determining the mean force from the work of friction, the following are determined: the actual stroke \(H_m\), the mean heights \(h'_v\), \(h'_n\), and the mean pressures \(p'_v\), \(p'_n\) on the diagrams, the mean indicator forces \(P'_v\) and \(P'_n\), and the free force during the downward stroke of the piston.

After the free force has been determined, the values of the energy and impact velocity can be determined. Indeed, the balance of the work of the active forces and the resistance forces at the moment of impact is equal to the effective energy of the hammer. The latter can be determined from the expression

\[ L_e = P'_{sv} H_m + G H_m - R H_m = P'_{sv} H_m + (G - R)H_m = L'_i + L'_m. \]

As soon as the effective energy of the hammer becomes known, the magnitude of the velocity at the moment of impact is determined at once:

\[ L_e = \frac{m v^2}{2}, \]

where \(m\) is the mass of the falling parts of the hammer,

\(v\) is the actual velocity:

\[ v = \sqrt{\frac{2g}{G} L_e} = K \sqrt{L_e}\ \mathrm{m/sec}. \]

The results of processing the indicator diagrams of each test, for determining the impact energy and velocity, are summarized in Table 9.

7. Determination of the Time of the Downward and Upward Strokes of the Ram During Operation of the Hammer

For this purpose, a hodograph was initially used. A description of its operation and design is given in the journal Orgenergo, No. 4 for 1936. The recor-

obtained with the aid of the hodograph curves (Fig. 25) showed that the time spent on one double stroke of the hammer ram consists of:

1. The time required for the fall of the ram.
2. The time required for pressing (holding the ram on the forging).
3. The time required for lifting the ram.

Fig. 25.

The duration of the individual sections of the curves is different. The time required for lifting and falling of the ram depends on the working air processes taking place in the lower and upper cavities of the hammer cylinder. These, in turn, depend on the adjustment of the hammer. The time required for pressing depends almost entirely on the individual ability of the operator.

Consequently, calculating the number of blows of the hammer ram with allowance for pressing does not give a complete idea of the degree of perfection of the hammer’s operation. In order to judge the operation of the hammer under one adjustment or another, it is necessary to calculate the machine time, i.e., the time required for lifting and falling of the ram. However, the use of the hodograph did not make it possible to evaluate individual adjustments from the standpoint of minimum expenditure of machine time, because it did not ensure a constant speed of motion of the tape.

Owing to the presence of this defect in the operation of the hodograph, the determination of the time of lifting and falling of the ram was carried out by a graphical method. This method consists of a series of successive graphical constructions (Fig. 32). The graphical method for determining energy and velocity as a function of travel is set forth in the journal Vestnik metallopromyshlennosti, No. 4 for 1936, in the article “On the Study of Indicator Diagrams of Steam-Air Hammers.” After the velocity curves of the ram motion have been found, curves of time as a function of travel are constructed. The construction described below is given.

Having the curves \(v=f(H)\) and knowing that

\[ v=\frac{dH}{dt}, \qquad v=\beta y; \qquad H=\alpha x \]

(\(\alpha, \beta\)—scales), we obtain

\[ dt=\frac{dH}{v}=\frac{\alpha}{\beta}\cdot \frac{dx}{y} \tag{1} \]

As is known, graphical integration of equation (1) is impossible. To obtain \(t\) by graphical integration, a new variable \(z\) is introduced, connected with the ordinate \(y\) by the following relation:

\[ y\cdot z=a^2, \]

where \(a\) is a constant segment.

Making the substitution in equation (1), we have

\[ dt=\frac{\alpha}{\beta a^2}\,z\,dx \]

\[ t=\frac{\alpha}{\beta a^2}\int_0^H z\,dx=\tau\int_0^H z\,dx \tag{2} \]

(\(\tau\)—scale).

From the obtained equation (2) it is clear that the determination of the time is reduced to the construction of the auxiliary curve \(z=f(H)\) and its graphical integration.

However, in constructing the curve \(z=f(H)\) a difficulty is encountered, which consists in the fact that at those points of the piston stroke where the velocity is equal to zero (\(y=0\)), the ordinates of the auxiliary curve become infinitely large (\(H\) is a finite quantity). It is therefore necessary to limit the portions of construction of the auxiliary curve to such ordinates (\(y_c\) and \(y_k\)) on the velocity curve that, for the selected segment \(a\), the magnitude of the ordinate of the auxiliary curve would fit on the drawing. The values \(y_c\) and \(y_k\) should be taken as small as possible, so that the remaining portions of the piston stroke (from \(y_c\) to \(y=0\) and from \(y_k\) to \(y=0\)) would not exceed, in total, 6–8% of the full stroke.

The ordinates of the auxiliary curve are found in the following way.

On the abscissa axis of the curve \(v=f(H)\), a square is constructed with side equal to \(a\) (see the construction for one point, Fig. 32), and the points of the curve \(v=f(H)\) are projected onto the vertical side of the square or onto its extension.

Through the obtained points and the point \(O\) of the square, rays are drawn. The intersection of these rays with the horizontal side of the square or with its extension forms a series of segments. Transferring the segments to the corresponding points of the piston stroke gives the ordinates of the auxiliary curve. From the obtained auxiliary curve \(z=f(H)\), the curve \(t=f(H)\) is constructed by graphical integration.

In the case where, in the integration, the same segment \(a\) is taken as the constant segment which was used in constructing the auxiliary curve, the scale of the curve \(t=f(H)\) is expressed by the following relation:

\[ \tau=\frac{\alpha}{\beta\cdot a},\ \text{sec},\ \text{mm}^{-1} \]

The time over the portion of the piston stroke from the ordinate \(y_c\) to the ordinate \(y=0\) of the curve \(v=f(H)\) is determined by the formula:

\[ \Delta t=\sqrt{\frac{2\Delta H}{j_{cp}}}, \]

where \(j_{cp}\) is the mean value of the acceleration over the given portion \(\Delta H\).

The time obtained, expressed on the adopted scale, is laid off on the ordinate drawn at the end of the path segment \(\Delta H\) (the velocity is equal to \(y_c\)). The end point of the time segment is the initial point for constructing the curve \(t=f(H)\). The time over the section of piston travel from the ordinate \(y_k\) to \(y=0\) is determined in exactly the same way as it is determined over the section from the ordinate \(y_c\) to the ordinate \(y=0\).

The time found is added to the final ordinate of time, which is the result of determining the time over the sections of the path from \(y=0\) to \(y=y_k\). The ordinate obtained, on the corresponding scale, determines the time of the piston’s upward travel. The results of the determination of time are summarized in Table e.

8. Determination of the Coefficients Characterizing the Efficiency of Hammer Operation

The operation of the hammer may be evaluated from two points of view: from the standpoint of the utilization of energy and from the standpoint of the utilization of time. In accordance with this, the following coefficients are introduced:

a) Coefficient of Energy Utilization

If we denote:

\(L_v\)—the actual energy of the blow, expressed in kgm,

\(L_m\)—the energy of the blow without taking account of the influence of friction, i.e.

\[ L_m=L_i' + G\cdot H_m\ \text{kgm}, \]

\(L_{\mathrm{в}}\)—the energy of the blow without taking account of the influence of friction under the condition of the piston moving downward with the pressure in the lower cavity of the cylinder equal to \(p_k\)—the exhaust pressure,

i.e.

\[ L_{\mathrm{в}}=(P_{\mathrm{в}}' + G - P_k)H_m\ \text{kgm}; \]

where

\[ P_{\mathrm{в}}'=p_{\mathrm{в}}F \]

\[ P_k=p_k\alpha F, \]

\(L_o\)—the energy of the blow without taking account of the influence of friction under the condition of the piston moving downward with pressure \(p_{\mathrm{в}}\) in the lower cavity and with pressure \(p_o\) (main-line pressure) in the upper cavity, i.e.

\[ L_o=(P_o+G-P_k)H_m\ \text{kgm}, \]

where

\[ P_o=p_oF, \]

\(L_n\)—the blow energy representing the energy under the condition of utilizing the full stroke \((H_{max})\) of the piston, i.e.

\[ L_n=(P_o+G-P_k)H_{max}\ \text{kgm}. \]

Note. \(L_v\); \(L_m\); \(L_{\mathrm{в}}\); \(L_o\)—are determined for the actual piston stroke.

\[ K_m=\frac{L_v}{L_m} \]
—the mechanical coefficient of energy utilization;

\[ K_{\mathrm{в}}=\frac{L_m}{L_{\mathrm{в}}} \]
—the coefficient of utilization of the exhaust process;

\[ K_o=\frac{L_{\mathrm{в}}}{L_o} \]
—the coefficient of utilization of the admission process;

\[ K_n=\frac{L_o}{L_n} \]
—the coefficient of utilization of the piston stroke;

\[ K=K_m\cdot K_{\mathrm{в}}\cdot K_o\cdot K_n \]
—the total coefficient of energy utilization.

b) Coefficient of Time Utilization

\[ \frac{t_o}{t_0} \]
—the coefficient of time utilization during the upward stroke of the piston;

\(\dfrac{t_0'}{t_\partial'}\)—coefficient of utilization of time during the downward stroke of the piston;

\[ \lambda=\frac{t_0+t_0'}{t_\partial+t_\partial'} \]

—the overall coefficient of utilization of time.

Here the following are denoted:

\(t_\partial\)—actual time of the upward stroke of the piston, expressed in seconds;
\(t_\partial'\)—actual time of the downward stroke of the piston;
\(t_0\)—theoretical time of the upward stroke of the piston;
\(t_0'\)—theoretical time of the downward stroke of the piston.

\[ t_0=\sqrt{\frac{2h_\partial}{j}}\ \text{sec}, \quad \text{where} \quad j=\frac{\left[F(\alpha p_0-p_в)-G\right]g}{G}\ \text{m/sec}^2 \]

\[ t_0'=\sqrt{\frac{2h_\partial}{j'}}\ \text{sec}, \quad \text{where} \quad j'=\frac{\left[F(p_0-\alpha p_в)+G\right]g}{G}\ \text{m/sec}^2 \]

Note. The actual and theoretical times are determined for the actual piston stroke \(H\).

\(F\)—upper area of the piston in \(\text{cm}^2\);
\(\alpha\)—ratio of the areas below and above the piston;
\(G\)—actual weight of the falling parts;
\(p_0\)—air pressure in the supply pipeline, in ati;
\(p_в\)—air pressure in the exhaust pipeline, in ati.

c) Power coefficient.

The power coefficient \((R)\) gives a complete representation of the effectiveness of the hammer’s operation. This coefficient is the product of the energy-utilization coefficient and the time-utilization coefficient

\[ R=K\lambda. \]

The results for determining these coefficients are summarized in Table zh. Comparing the individual columns of the table, one can easily judge the advantages and disadvantages of each adjustment.

III. Tests and Analysis of the Operation of the 3-Ton Hammer.

1. Results of the first hammer test (under the existing conditions).

By the time of the first hammer test, its principal parameters had not undergone any changes, with the exception only of the height of the dies. The total height of the dies was \(2h_\partial=545\ \text{mm}\). The height of the upper die was \(h_\partial=280\ \text{mm}\).

Table a.

Air consumption according to indicator diagrams.

Nos. of ind. diagr.	\(p_0\) ati	\(t^\circ\) C	\(T\)	\(v_0\), m³/kg	\(p_1\) ati	\(p_2\)	\(p_3\)	\(p_4\)	\(v_1\), m³/kg	\(v_2\), m³/kg	\(v_3\), m³/kg	\(v_4\), m³/kg
1	7.2	33	306	0.124	5.1	3.8	4.2	2.5	0.158	0.196	0.181	0.263
2	"	"	"	"	5.2	4.3	4.6	2.5	0.156	0.179	0.189	0.263
3	"	"	"	"	4.7	3.3	3.6	2.2	0.167	0.216	0.203	0.286
4	"	"	"	"	4.6	3.3	3.9	2.5	0.170	0.216	0.191	0.263
5	"	"	"	"	4.7	3.1	3.7	2.2	0.167	0.226	0.200	0.286

Table b.

Nos. of indicator diagrams	Bottom air, \(aF = 1356\ \mathrm{cm}^2\): \(\varphi_h H_m\), m	Bottom air, \(aF = 1356\ \mathrm{cm}^2\): \(\gamma H_m\), m	\(\gamma_1 H_m\), m	\(\beta_1 H_m\), m	\(\varphi_0 H_m\), m	Top air, \(F = 1611\ \mathrm{cm}^2\): \(\gamma_1' H_m\), m	Top air, \(F = 1611\ \mathrm{cm}^2\): \(\gamma_1' H_m\), m	Top air, \(F = 1611\ \mathrm{cm}^2\): \(\beta_1' H_m\), m
1	0.520	0.450	0	0	0.491	0.640	0.100	0.082
2	0.520	0.447	0	0	0.486	0.645	0.096	0.073
3	0.488	0.573	0	0	0.376	0.787	0.095	0.085
4	0.500	0.622	0	0	0.311	0.840	0.098	0.107
5	0.515	0.680	0	0	0.246	0.890	0.093	0.125

Table c.

No. of indicator diagram	\(V_1\), \(\mathrm{m}^3\)	\(V_2\), \(\mathrm{m}^3\)	\(V_3\), \(\mathrm{m}^3\)	\(V_4\), \(\mathrm{m}^3\)	\(Q_1\), kg	\(Q_2\), kg	\(Q_3\), kg	\(Q_4\), kg	\(Q_h\), kg	\(Q_v\), kg	\(Q\), kg	\(V\), \(\mathrm{m}^3\)	\(\dfrac{V}{L_e}\), \(\mathrm{m}^3/\mathrm{kg}\)
1	0.132	0.070	0.182	0.108	0.835	0.357	1.005	0.410	0.478	0.595	1.075	0.88	0.00023
2	0.131	0.070	0.182	0.105	0.840	0.390	0.962	0.400	0.450	0.562	1.012	0.83	0.00024
3	0.144	0.066	0.187	0.089	0.862	0.306	0.920	0.311	0.556	0.609	1.165	0.95	0.00021
4	0.152	0.068	0.185	0.083	0.894	0.315	0.968	0.316	0.579	0.652	1.231	1.01	0.00019
5	0.170	0.070	0.183	0.075	1.020	0.310	0.915	0.262	0.710	0.655	1.363	1.12	0.00020

Mean force from the work of friction.

Table g.

No. of indicator diagram	\(l\), mm	\(H_m\), m	\(\Phi_h\), \(\mathrm{mm}^2\)	\(h_h\), mm	\(p_h\), \(\mathrm{kg}/\mathrm{cm}^2\)	\(\Phi_v\), \(\mathrm{mm}^2\)	\(h_v\), mm	\(p_v\), \(\mathrm{kg}/\mathrm{cm}^2\)	\(P_h\), kg	\(P_v\), kg	\(P_{sv}\), kg	\(G\), kg	\(R\), kg	\(R\%\)
1	39.0	0.640	1080	27.7	4.62	380	9.75	1.65	6120	2660	3460	3010	450	15

Velocity of the ram and energy of impact.

Table d.

No. of indicator diagram	\(l\), mm	\(H_m\), m	\(\Phi_v'\), mm	\(h_v'\), mm	\(p_v'\), \(\mathrm{kg}/\mathrm{cm}^2\)	\(\Phi_h'\), mm	\(h_h'\), mm	\(p_h'\), \(\mathrm{kg}/\mathrm{cm}^2\)	\(P_v'\), kg	\(P_h'\), kg	\(P_{sv}'\), kg	\(L_i\), kgm	\(L_m'\), kgm	\(L_e\), kgm	\(v\), m/sec
1	39.0	0.640	900	23.0	3.85	510	13.0	2.17	6200	2950	3250	2078	1635	3715	4.9
2	39.4	0.645	900	22.8	3.80	600	15.2	2.54	6120	3450	2670	1720	1650	3370	4.7
3	48.0	0.787	980	20.4	3.40	510	10.65	1.78	5480	2420	3060	2420	2010	4430	5.4
4	51.3	0.840	1200	23.4	3.90	560	10.9	1.82	6280	2470	3810	3210	2150	5360	5.90
5	54.3	0.890	1180	21.9	3.65	530	9.70	1.62	5720	2200	3520	3150	2280	5410	5.90

Note: The velocity at the moment of impact was computed from the relation

\[ v = K \sqrt{L_e}, \]

where

\[ K = \sqrt{\frac{2g}{G}} = \sqrt{\frac{2 \cdot 9{,}81}{3010}} = 0{,}06. \]

Table e.

Results of determining the time by the graphical method (Fig. 32).

Nos. of indicator diagrams	Time in sec. per ram stroke	Time in sec. per ram stroke	Time in sec. per ram stroke
	Down	Up	Down and up
4	0,242	0,59	0,832

Table zh.

Values of coefficients characterizing the efficiency of hammer operation.

Nos. of indicator diagrams	\(L_e\), kgm	\(H_m\), m	\(K_m\)	\(K_v\)	\(K_o\)	\(K_n\)	\(K\)	\(\lambda\)	\(R\)	Theoretical number of blows**)
3	4430	0,79	0,92	0,72	0,65	0,65	0,27	0,69*)	0,18	85
4	5360	0,84	0,94	0,74	0,71	0,67	0,32	0,62	0,19	72
5	5410	0,89	0,93	0,75	0,67	0,72	0,33	0,69*)	0,22	79

Note: ) Coeff. \(\lambda\) was calculated from data obtained by the hodograph.
*) The theoretical number of blows per minute is calculated from the machine time, i.e.

\[ n = \frac{60}{t_o + t_o'}. \]

2. Analysis of the Hammer Operation.

On the basis of an analysis of the results obtained, it follows that the hammer has a number of shortcomings.

1) Excessive height of the lower harmful space.

The excessive height of the lower harmful space results from the overly great height of the dies \(2h_0 = 545\) mm and the excessive length of the rod \(k\).

The resulting excessive height of the lower harmful space entails incomplete utilization of the energy capabilities of the hammer.

Thus, the actual maximum possible value of the piston stroke (see Fig. 10 of protocol No. 1), with dies having \(2h_0 = 545\) mm, is:

\[ H_2 - t - U_0 = 1435 - 190 - 275 = 970 \text{ mm}, \]

where

\(H_2\) — the height of the cylinder from the upper plane of the piston, lowered onto the lower cover, to the lower plane of the upper cover,

\(t\)—height of the safety device,

\(U_o\)—height of the actual harmful space,

\[ U_o = 2h_o - A = 545 - 270 = 275\ \text{mm}. \]

In the case of a normal value of the lower harmful space, \(U_n — 70\ \text{mm}\), the piston stroke will be

\[ H_2 - t - U_n = 1435 - 190 - 70 = 1175\ \text{mm}. \]

Thus the actual maximum piston stroke turned out to be less than the normal one by \(1175 - 970 = 205\ \text{mm}\).

This indicates incomplete use of the stroke, and consequently a reduction in impact energy, as well as unproductive consumption of air.

A measure for eliminating this shortcoming may be the installation of dies calculated in such a way that their total height lies within the range of \(340—420\ \text{mm}\).

However, in the event of shortening the rod, the indicated limits may be raised accordingly.

2) Incorrect adjustment.

From the diagram of valve opening (Fig. 26) it is evident that the distribution of the points of seating and lifting of the valves allows the presence, in both cavities of the cylinder, of processes of compression and expansion of air over a considerable portion of the stroke. The presence of such processes in the cylinder entails a reduction in the speed of piston motion and, as a consequence, a reduction in impact energy. This gives grounds for considering the existing valve setting incorrect.

In addition, from Table ж it is evident that the value of the utilization coefficient of the exhaust process is low. This is caused by increased pressure in the lower cavity of the cylinder during the downward stroke of the piston. From the indicator diagrams (Fig. 26) it follows that the average pressures over these sections of the piston stroke are from \(2.17\) to \(2.54\ \text{kg}/\text{cm}^2\) for light blows and from \(1.62\) to \(1.82\ \text{kg}/\text{cm}^2\) for heavy blows.

Such increased back pressures are caused by insufficient opening of valve (4) of the lower exhaust. Indeed, at the moment when the ram comes into contact with the forging, for light blows the valve lift is \(10\ \text{mm}\), and for heavy blows \(17\ \text{mm}\). These openings provide, respectively, live cross sections for the passage of air

\[ f_3' = 1.0 \cdot 3 \cdot 10 = 30\ \text{cm}^2 \]

and

\[ f_3'' = 1.7 \cdot 3 \cdot 10 = 51\ \text{cm}^2. \]

With the final speed of piston motion \(v = 4.9\ \text{m/sec}\), in the first approximation, the velocity of air outflow for light blows is

\[ \omega_o = \frac{v \cdot aF}{f_3'} = \frac{4.9 \cdot 1356}{30} = 222\ \text{m/sec}. \]

With the final speed of piston motion \(v = 5.9\ \text{m/sec}\), the velocity of air outflow for heavy blows is

\[ \omega_1 = \frac{v \cdot aF}{f_3''} = \frac{5.9 \cdot 1356}{51} = 157\ \text{m/sec}. \]

The obtained outflow velocities once again confirm the opinion expressed above regarding insufficient opening of valve (4). To obtain dia-

Fig. 26.

Labels visible in the figure:

• lower admission
• upper exhaust
• exhaust line
• upper exhaust
• upper admission
• opening of the valves
• diagram of the stroke of the admission valves according to the cutoff of the ram stroke
• indicator diagrams of the upper cavity of the cylinder
• indicator diagrams of the lower cavity of the cylinder
• scale: \(1\ \mathrm{mm} = 16.375\ \mathrm{mm}\)
• \(1\ \mathrm{kg}/\mathrm{cm}^{2} = 6\ \mathrm{mm}\)
• 100% opening
• 100% exhaust
• [[unclear: handwritten note at top, apparently “graph of theoretical lines …”]]

without significant back pressure from below it is necessary to have the maximum value of the air outflow velocity \(\omega = 80\ \text{m/sec}\).

The indicated air outflow velocity can be ensured by the effective area

\[ f=\frac{v \cdot \alpha F}{\omega_{\max}}=\frac{5.9 \cdot 1356}{80}=100\ \text{cm}^2. \]

However, it makes no sense to obtain such a lift of the valve, at which such an effective area is provided, because along the path of air motion from the lower cavity of the cylinder there is a constant section \(f_7=80.5\ \text{cm}^2\) (Fig. 27); the latter will limit the pressure in the cylinder. Thus, it is expedient to increase the opening only to

\[ h=\frac{80.5}{3 \cdot 10}\simeq 2.7\ \text{cm}\simeq 27\ \text{mm}. \]

Analysis of the value of the maximum opening of valve 1 of the upper admission also indicates that its opening is insufficient for creating normal, for the given design of the valve chest, velocities of air inflow. Indeed, opening the valve by \(13\ \text{mm}\) provides an effective area \(f_3=1.3 \cdot 3.10=39\ \text{cm}^2\), limiting the pressure in the upper cavity of the cylinder, since the value of the constant section \(f_7=80.5\ \text{cm}^2\) is greater than \(f_3\).

Consequently, the amount of valve lift must be brought to

\[ h=\frac{80.5}{3.10}\simeq 2.7\ \text{cm}\simeq 27\ \text{mm}. \]

Fig. 27.

Ram stroke	Direction of air motion	$f_1$	$10 f_{3\max}$	$f_4$	$4 f_5$	$2 f_6$	$f_7$	$f_8$	$10 f_{9\max}$	$f_{10}$	$f_{11}$	$f_{12}$
Down	Admission	189	105	113	84	154	80.5	115	—	—	—	—
Down	Exhaust	—	—	—	—	—	—	—	105	113	172	122
Up	Admission	189	105	113	84	154	80.5	115	—	—	—	—
Up	Exhaust	—	—	—	—	—	—	—	105	113	172	122

Top view.  Section along C–D.

Fig. 28.

3) Insufficient lifting of the valves for a given handle travel.

Insufficient lifting of the valves of the lower exhaust (4) and the upper admission (1) is not only the result of improper adjustment, but also of the presence of considerable lost motion in the links of the distributing mechanism. The influence of lost motion (from link $d$ to the valves) on the magnitude of the valve lifts can be judged from the dotted lines plotted on the valve-opening diagram (Fig. 15).

In the principal positions of the distributing mechanism shown (Fig. 4), the valve openings were obtained by graphical constructions. These constructions do not take into account the influence of lost motion on the opening of the valves. During operation of the hammer it was observed that the lever carrying the weight comes up against the link of the distributing mechanism of valve 4 of the lower exhaust. This leads to the fact that, over the portion of the control-handle travel from the 7th to the 8th division, valves 2 and 5 do not lift at all, despite the continuing movement of the handle.

Thus it turned out that the maximum opening values of valves 2 and 5 corresponded to the valve-opening values at the 7th position of the handle on the sector.

The latter is also marked on the handle-displacement graphs by a dashed line (Fig. 26). The excess of the curves of these graphs above the dashed line indicates the magnitude of the elastic deformation of the lever carrying the load.

4) Excessive pressures above the valves of the upper (1) and lower (3) admissions.

When the upper covers of the slide-valve box were removed, it was found that:

1. The clearance between the lateral surfaces of the valves and the bushings reaches 0.5 mm on each side.

2. Under the unloading valves of the upper and lower admission valves, washers with slots had been placed.

The pressure diagrams shown in Fig. 26 correspond to the indicated condition of valve 1. Considering these diagrams, one may note that the pressure curve \(ab\), corresponding to the downward stroke of the piston, has the same character as the pressure curve in the upper cavity of the cylinder corresponding to this period. This becomes entirely clear if one takes into account that during this period of time the space above the valve is connected with the upper cavity of the cylinder (Fig. 27). The curve \(vgda\) corresponds to the upward motion of the piston. Part \(vg\) of this curve indicates that in the first part of the upward piston stroke valve 1 of the upper admission is closed, and above it, owing to the presence of a large clearance between its lateral surface and the surface of the bushing, a pressure almost equal to the main-line pressure is established.

However, beginning from the moment the unloading valve opens, this pressure drops sharply, and by the end of the opening of the unloading valve it almost reaches the value of the pressure then present in the upper cavity of the cylinder. Then, after valve 1 has begun to open, the space above the valve is connected with the upper cavity, and the character of the pressure curve above the valve becomes completely identical with the character of the pressure curve in the upper cavity of the cylinder.

If the pressure drop as the air passes through the openings of the unloading valve is neglected, it may be assumed that the difference between the ordinates of the pressures at the beginning and at the end of the stroke of the unloading valve constitutes the pressing force which holds valve 1 on its seat. Obviously, with an increase in the pressing force, the force required to move the control handle will also increase.

In order to reduce the pressure in the spaces above the valves, it is necessary to reduce the clearance between the lateral surfaces of the working valves and the bushings. It should be noted that if the pressures above valves 1 and 3 are reduced too much, they may open spontaneously. The use by shop workers of washers with slots leads to an excessive consumption of compressed air.

Thus, for example, when the exhaust valves are open (Figs. 27 and 28), air from the main line, passing through the lateral clearances of the admission valves into the slots in the washers, can escape into the atmosphere. In addition to the indicated leakage, which occurs over the greater part of the upward and downward piston strokes, part of the compressed air enters the corresponding cavities of the cylinder and thereby contributes to an increase in back pressure in these cavities. The foregoing gives grounds for recognizing that the use of washers with slots for unloading valves is inadmissible.

5) Measures eliminating deficiencies in the operation of the hammer.

On the basis of the above analysis, the following measures were outlined to ensure an increase in the efficiency of the hammer:

1. Installation of an upper die with height \(h = 160\) mm, instead of the existing die \(h = 280\) mm.

1. Changing the existing adjustment in the direction of obtaining maximum coefficients \(K_v\), \(K_o\) and

2. Eliminating dead travel in the links of the distributing mechanism.

3. Lapping the valves.

Before carrying out tests after implementation of all four measures, it was of interest to determine the role of the individual factors. For this purpose a second test was carried out.

Fig. 29.

3. Results of the Second Test.

The second test was carried out with the hammer adjustment changed. All other factors during the second test remained unchanged. The change in adjustment consisted in creating an increased opening of valve 4 of the lower exhaust. The indicator diagrams taken (Fig. 29) indicate a sharp decrease in pressure in the sections of the lower exhaust.

A decrease in pressure in the sections of the lower exhaust usually entails an increase in the velocity and energy of the blow. Below are given the results for determining the velocity and energy of the blow.

After the second test the hammer was sent for major overhaul, during which measures 3 and 4 were carried out.

When the hammer was started, it was found that the hammer could not operate, owing to spontaneous openings of the valves. As a temporary measure, to eliminate spontaneous openings of valves 1 and 3, washers with slots were installed on the seats of the unloading valves. However, this measure did not completely eliminate the spontaneous opening of the valves.

Speed of the ram and impact energy.
Table d.

Nos. of indicator diagrams	$l$, mm	$H_m$, m	$\Phi_v'$, mm²	$h_v'$, mm	$p_v'$, kg/cm²	$\Phi_n'$, mm²	$h_n'$, mm	$p_n'$, kg/cm²	$P_v'$, kg	$P_n'$, kg	$P_{sv}$, kg	$L_i'$, kg·m	$L_m'$, kg·m	$L_e$, kg·m	$v$, m/sec
6	48	0.780	990	20.6	3.44	170	3.54	0.59	5540	800	4740	3700	2000	5700	6.1
7	50	0.815	1100	22.0	3.67	230	4.60	0.77	5920	1040	4880	3980	2080	6060	6.3
8	51.5	0.845	1150	22.4	3.72	70	1.36	0.23	6000	304	5696	4800	2160	6960	6.7

4. Results of the Third Test.

In the third test of the hammer, emphasis was placed on identifying those results that are introduced by the changed adjustment into the operation of the hammer. The following considerations were taken as the basis for changing the adjustment:

1. Preventing the simultaneous opening of the admission and exhaust valves belonging to one and the same cylinder cavity.

2. Bringing the openings of valves 1 and 4 up to normal values in order to increase the coefficients $K_v$ and $K_o$.

3. Bringing the openings of valves 2 and 3 to such values that, while creating a normal sequence of the processes of upper exhaust and lower admission, they could produce an increase in the coefficient $\lambda$.

In view of the fact that one and the same adjustment cannot be perfect both from the standpoint of maximum utilization of energy (coefficient $K$) and from the standpoint of maximum utilization of time (coefficient $\lambda$), two variants of adjustment were established:

1. An adjustment providing for operation of the hammer with the maximum number of blows.

2. An adjustment providing for the greatest output of the hammer in terms of impact energy.

The third test of the hammer was carried out after all four of the above measures had been implemented.

Below are given the results for determining the speed and energy of the blows.

Average force from friction work.
Table g.

Nos. of indicator diagrams	$l$, mm	$H_m$, m	$\Phi_n$, mm²	$h_n$, mm	$p_n$, kg/cm²	$\Phi_v$, mm²	$h_v$, mm	$p_v$, kg/cm²	$P_n$, kg	$P_v$, kg	$P_{sv}$, kg	$G$, kg	$R$, kg	$R\%$
10	66	1.085	1350	20.7	3.5	380	5.7	0.96	4770	1520	3260	3010	250	8.2

Speed of the ram and impact energy.
Table d.

Nos. of indicator diagrams	$l$, mm	$H_m$, m	$\Phi_v'$, mm²	$h_v'$, mm	$p_v'$, kg/cm²	$\Phi_n'$, mm²	$h_n'$, mm	$p_n'$, kg/cm²	$P_v'$, kg	$P_n'$, kg	$P_{sv}'$, kg	$L_i'$, kg·m	$L_m'$, kg·m	$L_e$, kg·m	$v$, m/sec
9	60.0	0.980	1260	21.0	3.50	460	7.66	1.28	5640	1735	3905	3825	2700	6525	6.5
10	66.0	1.085	1260	19.1	3.17	410	6.20	1.04	5120	1405	3715	4030	3000	7030	6.75

Figure 30.

Indicator diagrams taken with the upper valves lowered to their seats.
Valve-opening graph as a function of handle position.
1st adjustment.

Labels in the left small graph:

• Valve lift
• Lower valve
• Upper exhaust valve
• Lower exhaust valve
• Upper valve
• Valve opening

Labels in the left indicator-diagram group:

• No. 9
• Heavy blow
• Valve opening
• Diagram at bringing the upper valves to their seats
• Indicator diagram of the upper cylinder cavity
• Indicator diagram of the lower cylinder cavity
• Maximum, \(1\ \mathrm{mm} = 14.88\ \mathrm{atm}\)

At insufficient bringing of the valves to the seats.
Valve-opening graph as a function of handle position.
2nd adjustment.

Labels in the right small graph:

• Valve lift
• Lower valve
• Upper valve
• Lower exhaust valve
• Upper exhaust valve
• Valve opening

Labels in the right indicator-diagram group:

• No. 10
• Heavy blow
• Valve opening
• Additional opening of the hand-distribution valve to the full stroke
• Maximum, \(1\ \mathrm{mm} = 16.35\ \mathrm{atm}\)

Additional handwritten labels and scale markings visible in the diagrams:

• \(1\ \mathrm{mm} = 6\ \mathrm{atm}\)
• \(1\ \mathrm{mm} = 6\ \mathrm{atm}\)
• \(800\)
• \(900\)
• \(1100\)
• \(1300\)
• \(75\)
• \(26\)
• \(8, 7, 6, 5, 4, 3, 2, 1, 0\)
• \(7, 6, 5, 4, 3, 2, 1, 0\)

The tables indicate that the third test did not give the desired results. This occurred because the character of the indicator diagrams (Fig. 30) proved unsatisfactory. The latter was expressed in a sharp fall of the pressure curve of the upper admission downward, and also in a rise of the pressure curve of the lower exhaust.

Observation of the hammer’s operation showed that the reason for this lay in the spontaneous opening of valve 3 of the lower admission during the downward stroke of the ram.

In order to eliminate the indicated defect, 4 holes were drilled in each of valves 1 and 3. The holes were threaded so that threaded plugs, provided with holes of various diameters, could be screwed into them.

5. Results of the fourth test.

By the time of the fourth test the condition of the hammer was not entirely satisfactory, owing to leakage of compressed air through the gasket of the upper cylinder cover. The dies were installed with a total height \(2h_0 = 420\) mm. (Height of the upper die \(h_0 = 160\) mm).

Table a.

Air consumption according to indicator diagrams.

Nos. of indicator diagrams	\(p_0\)	\(t^\circ C\)	\(T\)	\(v_0,\ m^3/kg\)	\(p_1\) atm	\(p_2\) atm	\(p_3\) atm	\(p_4\) atm	\(v_1,\ m^3/kg\)	\(v_2,\ m^3/kg\)	\(v_3,\ m^3/kg\)	\(v_4,\ m^3/kg\)
11	7,0	34°	307	0,128	3,0	2,0	3,8	2,3	0,163	0,311	0,197	0,244
12	7,0	34°	307	0,128	4,8	2,2	3,5	1,8	0,167	0,304	0,240	0,334
13	7,0	31°	304	0,128	5,0	2,0	3,7	2,1	0,161	0,308	0,199	0,298

Table b.

Nos. of indicator diagrams	Lower air \(\alpha F = 1356\ cm^2\) \(\varphi_u H_m,\ m\)	Lower air \(\alpha F = 1356\ cm^2\) \(\gamma H_m,\ m\)	Lower air \(\alpha F = 1356\ cm^2\) \(\gamma_1 H_m,\ m\)	Lower air \(\alpha F = 1356\ cm^2\) \(\beta_1 H_m,\ m\)	Upper air \(F = 1611\ cm^2\) \(\varphi_0 H_m,\ m\)	Upper air \(F = 1611\ cm^2\) \(\gamma' H_m,\ m\)	Upper air \(F = 1611\ cm^2\) \(\gamma_1' H_m,\ m\)	Upper air \(F = 1611\ cm^2\) \(\beta_1' H_m,\ m\)
11	0,380	0,565	0	0	0,301	0,970	0,265	0
12	0,408	0,615	0	0	0,263	0,980	0,293	0
13	0,350	0,492	0	0	0,325	0,976	0,276	0

Table c.

Nos. of indicator diagrams	\(Y_1\), \(m^3\)	\(Y_2\), \(m^3\)	\(Y_3'\), \(m^3\)	\(Y_4\), \(m^3\)	\(Q_1\), kg	\(Q_2\), kg	\(Q_3\), kg	\(Q_4\), kg	\(Q_n\), kg	\(Q_v\), kg	\(Q\), kg	\(Y_0\), \(m^3\)	\(\dfrac{Y_0}{L_\mathrm{э}}\), \(m^3/kg\)
11	0,128	0,051	0,204	0,091	0,786	0,016	1,036	0,373	0,77	0,663	1,433	1,17	0,00014
12	0,138	0,055	0,200	0,039	0,827	0,018	0,952	0,266	0,809	0,686	1,495	1,22	0,00017
13	0,114	0,047	0,209	0,097	0,708	0,015	1,050	0,326	0,693	0,724	1,417	1,16	0,00015

Table g.

Mean force from friction work.

Nos. of indicator diagrams	$l$, mm	$H_m$, m	$\Phi_n$, mm²	$h_n$, mm	$p_n$, kg/cm²	$\Phi_v$, mm²	$h_v$, mm	$p_v$, kg/cm²	$P$, kg	$P_v$, kg	$P_{sv}$, kg	$G$, kg	$R$, kg	$R\%$
13	59,5	0,976	1390	23,4	3,9	450	7,55	1,26	5290	2025	3265	3010	250	8,05

Table d.

Ram velocity and blow energy.

Nos. of indicator diagrams	$l'$, mm	$H_m'$, m	$\Phi_v'$, mm²	$h_v'$, mm	$p_v'$, kg/cm²	$\Phi_n'$, mm²	$h_n'$, mm	$p_n'$, kg/cm²	$P_v'$, kg	$P_n'$, kg	$P_{sv}'$, kg	$L_1'$, kgm	$L_m'$, kgm	$L_e'$, kgm	$v$, m/sec
11	59,2	0,970	1440	24,4	4,07	220	3,72	0,62	6550	840	5710	2680	5520	8200	7,3
12	59,7	0,980	1240	20,7	3,46	280	4,68	0,78	5570	1008	4512	2700	4420	7120	6,8
13	59,5	0,976	1360	22,8	3,80	230	3,86	0,64	6120	867	5253	3690	5130	7820	7,15

Table e.

Results of determining the times of the ram strokes upward and downward by the graphical method (Fig. 32).

Nos. of indicator diagrams	Down	Up	Down and up
11	0,226	0,52	0,746
13	0,24	0,58	0,82

Table zh.

Values of coefficients characterizing the efficiency of hammer operation.

Nos. of indicator diagrams	$L_e$	$H_m$	$K_m$	$K_v$	$K_o$	$K_n$	$K$	$\lambda$	$R$	Theoretical number of blows
11	8200	0,97	0,97	0,92	0,75	0,77	0,52	0,77	0,4	81
12	7120	0,98	0,97	0,88	0,68	0,78	0,45	—	—	—
13	7820	0,976	0,97	0,91	0,72	0,77	0,49	0,68	0,33	73

Indicator diagrams taken in the study of the “Bêché” hammer, 3 t.

Increase in the quantity of steam led in through the channels, depending on the position of the handle.

1st adjustment

No. 11
Strong blow

Position of the handle

• lower release
• upper release
• upper admission
• lower admission

Opening of the valve for admission of steam to the cylinder from the moment of its admission.

Indicator diagrams of the upper and lower cylinder chambers.

Valve lift \(h_{\max}=16.375\) mm.

Scale 1 mm = 16.375 mm.

2nd adjustment

Dependence of the opening of the channels in the slide valve on the position of the handle.

2nd adjustment

No. 12
Strong blow

Position of the handle

• lower release
• upper release
• upper admission
• lower admission

Opening of the valve for admission of steam to the cylinder from the moment of its admission.

Indicator diagrams of the upper and lower cylinder chambers.

Scale 1 mm = 16.375 mm.

No. 13
Strong blow

Position of the handle

• lower release
• upper release
• upper admission
• lower admission

Scale 1 mm = 16.375 mm.

When testing, the number of strokes per minute was 86; the steam pressure at the boilers was 4½ atm.

Fig. 31.

Comparing the indicator diagrams of the first test (Fig. 26) with the indicator diagrams of the fourth test (Fig. 31), one may conclude that the magnitude of the force pressing valve 1 to its seat in the fourth test is less than in the first test.

The latter indicates that less force will be required to move the control handle, and, in striving to facilitate the operator’s work, there is no need to place washers with slots under the unloading valves. As already indicated, the fourth hammer test was carried out with two adjustments. The character of each adjustment is revealed by the corresponding graph of valve opening (Fig. 31) as a function of the positions of the handle. Both adjustments have one common feature, namely that the moments of lifting and seating of the working valves of one and the same cavity coincide.

The first adjustment is designed for the maximum possible reduction of the time spent in lifting the ram. For this purpose, the point corresponding to the beginning of the opening of valve 3 of the lower inlet occupies a comparatively low position in the handle sector (the 4th division). This ensures sufficient opening of valves 2 and 3 during the upward stroke of the ram.

The second adjustment is aimed at obtaining the greatest possible blow energy. The latter is achieved by shifting the points corresponding to valve seating under the first adjustment upward by one division. Thus, in the second adjustment the seating moment of valves 1 and 2 of the upper cavity corresponds to the fourth division instead of the third, and the seating moment of valves 3 and 4 of the lower cavity to the fifth instead of the fourth. This makes it possible, at the lowest position (zero position) of the handle, to increase the opening of the upper-inlet valve 1 and the lower-exhaust valve 4, i.e., to create the most favorable conditions for obtaining the maximum blow energy.

Comparing the indicator diagrams of the first and fourth tests, it may be established that in the fourth test the hammer operated with better indices. Namely:

1. The magnitude of the ram stroke increased.
2. The mean pressure \(p'_{в}\) in the upper cavity over the inlet portion increased.
3. The mean pressure \(p'_{н}\) in the lower cavity over the exhaust portion decreased.
4. The mean pressure \(p'_{в}\)—of the upper cavity over the exhaust portion—decreased.

A graphical comparative study of the indicator diagrams obtained in the 1st, 3rd, and 4th tests is given in Fig. 32.

All the changes obtained in the indicator diagrams (Fig. 31) may be assessed only as positive factors.

Indeed, comparing the operating indices of the hammer (Fig. 33) under the new conditions, one can note a significant increase in the efficiency of the hammer’s operation. Thus, for example, the increase in blow energy reached

\[ \frac{8200-5360}{5360}\cdot 100 = 53\%. \]

A fuller characterization of the degree of increase in the efficiency of the hammer’s operation, under the changed conditions as compared with those existing before the changes were introduced, may be seen from the following table. (This table refers to blows with the greatest energy.)

Test conditions	Test No.	Regulation	Indicator diagram Nos. \(u_1\)	Indicator diagram Nos. \(u_2\)	Indicator diagram Nos. \(u_3\)	Indicator diagram Nos. \(u_4\)	Indicators \(L_{\mathrm{e}}\)	Indicators \(v\)	Indicators \(n\)	Indicators \(\gamma_0\)	Indicators \(\dfrac{\gamma_0}{L_{\mathrm{e}}}\)	Coefficients of use \(K_m\)	Coefficients of use \(K_v\)	Coefficients of use \(K_0\)	Coefficients of use \(K_{\mathrm{c}}\)	Coefficients of use \(K\)	Coefficients of use \(\lambda\)
Existing . . . . . . . . . . . . . . . . . .	1	Exist.	—	—	—	—	5360	5,9	72	1,01	0,00019	0,94	0,74	0,71	0,67	0,32	0,62
Change . . . . . . . . . . . . . . . . . .	4	1	1	10	22	12	8200	7,3	81	1,17	0,00014	0,97	0,92	0,75	0,77	0,52	0,7
Change . . . . . . . . . . . . . . . . . .	4	2	9	2	20	22	7820*)	7,15	73	1,16	0,00015	0,97	0,91	0,72	0,77	0,49	0,68

*) The reduced impact energy, when the areas of the indicator diagram of the upper cylinder passage are taken into account, was taken.

In the absence of this energy, the indicator diagram would have a higher value, since the curve of the upper-air pressure on the diagram would be below the exhaust (1).

This conclusion is confirmed by a third test.

Notes: 1. Methods for measuring dimensions fixing adjustment (setting) of the hammer are indicated in Protocol No. 2.

1. The specified air consumption does not take into account the leakage of air through leaks.

2. The coefficient \(\lambda\) is calculated on the basis of graphical plotting (Fig. 32).

Fig. 32.

Fig. 33-a.

Fig. 33-b.

IV. Tests and analysis of the operation of the 6-ton hammer.

1. Results of the first test (under the existing conditions).

Air consumption according to indicator diagrams. Table a.

Nos. of indicator diagrams	$p_0$ atm	$t^\circ C$	$T^\circ$	$v_0$, m³/kg	$p_1$ kg/cm²	$p_2$ kg/cm²	$p_3$ kg/cm²	$p_4$ kg/cm²	$v_1$ m³/kg	$v_2$ m³/kg	$v_3$ m³/kg	$v_4$ m³/kg
1	7,5	29	302	0,110	3,1	5,0	2,4	1,8	0,206	0,147	0,246	0,298
2	6,9	27	300	0,127	4,6	2,2	3,9	1,5	0,169	0,288	0,190	0,375
3	7,4	29	302	0,120	4,6	2,4	4,0	1,4	0,165	0,264	0,184	0,387

Table b.

Nos. of indicator diagrams	Lower air: $\alpha F = 1810$ cm², $\varphi_i H_t$ m	Lower air: $\alpha F = 1810$ cm², $\gamma H_t$ m	Lower air: $\alpha F = 1810$ cm², $\gamma_1 H_t$ m	Lower air: $\alpha F = 1810$ cm², $\beta_1 H_t$ m	Upper air: $F = 2124$ cm², $\varphi_0 H_t$ m	Upper air: $F = 2124$ cm², $\gamma' H_t$ m	Upper air: $F = 2124$ cm², $\gamma_1' H_t$ m	Upper air: $F = 2124$ cm², $\beta_1' H_t$ m
1	0,578	1,425	0,262	0	0,326	0,425	0,150	0,220
2	0,588	1,205	0	0	0,456	1,285	0,157	0,138
3	0,553	1,285	0	0	0,366	1,410	0,245	0,172

Table c.

Nos. of indicator diagrams	$V_1$ m³	$V_2$ m³	$V_3$ m³	$V_4$ m³	$Q_1$ kg	$Q_2$ kg	$Q_3$ kg	$Q_4$ kg	$Q_n$ kg	$Q_v$ kg	$Q$ kg	$V_0$	$\dfrac{V_0}{L_\mathrm{e}}$
1	0,362	0,105	0,318	0,144	1,76	0,51	1,29	0,48	1,25	0,81	2,06	1,69	0,00012
2	0,324	0,107	0,370	0,159	1,92	0,37	1,95	0,42	1,55	1,53	3,08	2,52	0,00017
3	0,332	0,100	0,378	0,166	1,99	0,38	2,05	0,43	1,61	1,62	3,23	2,66	0,00016

Mean force from friction work. Table d.

Nos. of indicator diagrams	$l$ mm	$H_t$ m	$\Phi_n$ mm²	$h_n$ mm	$p_n$ kg/cm²	$\Phi_v$ mm²	$h_v$ mm	$p_v$ kg/cm²	$P_n$ kg	$P_v$ kg	$P_{cv}$ kg	$G$ kg	$R$ kg	$R\%$
2	78,5	1,285	2220	28,3	4,71	260	3,31	0,55	8530	1960	7370	6550	820	12,5

Ram velocity and impact energy. Table e.

Nos. of indicator diagrams	$l$ mm	$H_t$ m	$\Phi_v'$ mm²	$h_v'$ mm	$p_v'$ kg/cm²	$\Phi_n'$ mm²	$h_n'$ mm	$p_n'$ kg/cm²	$P_v'$ kg	$P_n'$ kg	$P_{cv}$ kg	$L_i'$ kg m	$L_m'$ kg m	$L_\mathrm{e}$ kg m	$v$ m/sec
1	87	1,425	1760	20,2	3,37	800	9,2	1,53	6770	2770	4000	5700	8260	13960	6,5
2	78,5	1,285	1870	23,8	3,97	470	6,0	1,00	7980	1810	6170	7940	7360	15300	6,8
3	86	1,410	2170	25,2	4,2	560	6,5	1,08	8350	1950	6400	9030	8070	17100	7,2

Note: The velocity at the moment of impact was calculated from the relation:

\[ v = K \sqrt{L_\mathrm{e}}, \quad \text{where } K = \sqrt{\frac{2g}{G}} = \sqrt{\frac{2 \cdot 9{,}81}{6550}} = 0{,}055 \]

Table 4

Values of the coefficients characterizing the effectiveness of hammer operation.

Nos. of indicator diagrams	$L$, kg·m	$H_m$, m	$K_m$	$K_v$	$K_o$	$K_n$	$K$
1	13960	1.425	0.93	0.79	0.65	0.84	0.4
2	15300	1.285	0.93	0.87	0.76	0.76	0.47
3	17100	1.41	0.93	0.87	0.73	0.83	0.49

2. Analysis of the test results.

The analysis carried out made it possible to reveal a number of deficiencies.

1) Incorrect adjustment.

From the graph of valve opening (Fig. 34) it is evident that valve 1 of the upper admission and valve 2 of the upper exhaust rise and seat not simultaneously. Valve 1 rises and seats at those moments when the control handle occupies the third division on the sector, while valve 2 does so only when the handle is at the fifth division.

Thus, when the handle moves from the fifth division to the third, a process of air compression takes place in the upper cavity of the cylinder. As was indicated above, the presence of the air-compression process in the cylinder reduces the speed of motion of the piston, and consequently, with proper adjustment of the hammer, the compression process should not take place.

Considering further the valve-opening graph, it may be observed that valve 3 of the lower admission and valve 4 of the lower exhaust also rise and seat not simultaneously. Valve 3 rises and seats at those moments when the control handle is between the first and second divisions, while valve 4 does so only when the handle is at the fourth division. As a result of this arrangement of the seating and lifting points of valves 3 and 4, it follows that, when the handle is moved from the fourth division to the first (Fig. 8), the valves of the lower admission 3 and lower exhaust 4 are open.

In order to understand what happens at these moments to the air flow, it is necessary to refer to the diagram of air motion in the valve box (Fig. 7). It is quite obvious that at those moments when valve 4 of the lower exhaust is raised, with valve 3 of the lower admission open, the main air, without performing useful work, tends, together with the spent air from the lower cavity of the cylinder, to escape into the exhaust pipe. Analysis of the examined positions of seating and lifting of the valves makes it possible to conclude that the existing adjustment of the hammer is incorrect and leads to unproductive consumption of air.

In order to eliminate the unproductive consumption of air and avoid cycles of expansion and compression of air during its operation in the cylinder cavity, it is necessary to seat valves 3, 4 and valves 1, 2 so that the lifting and seating of each pair occur simultaneously.

As before, by virtue of the considerations set forth above, it is necessary to establish two adjustments: an adjustment ensuring the maximum number of blows (the first adjustment), and an adjustment ensuring the maximum energy of the blow (the second adjustment).

2) Presence of large dead travels in the links of the distributing mechanism.

Considering the valve-opening graph (Fig. 21 of protocol No. 2), it may be observed that the lifting of the valves is uneven over the entire travel of the handle;

the control handle. There are also portions on the graph where movement of the valves is almost not observed.

The presence of such portions on the graph indicates the appearance, in the links of the distributing mechanism, of very large clearances (obviously, the larger these portions, the larger the clearances in the links).

It should be noted, however, that the harmful influence of clearances is manifested not only in the unproductive movement of the handle over a certain sector, but also leads to a reduction in the magnitudes of valve opening. All reductions in valve opening as the clearances increase, in turn, lead to a lowering of the efficiency of the hammer’s operation. Therefore, for better operation of the hammer it is necessary to eliminate the existing lost motion in the distributing mechanism.

Particular attention must be paid to the joints of the ends of the levers (rockers) with the cups.

3) Insufficient dimensions of the ports in the valve bushings (liners).

Tracing, according to the diagrams (Fig. 7), the movement of the air flow when it is admitted into the cylinder cavities, and calculating from the drawings the “live” cross sections of the passing channels and openings (Fig. 6), it can be observed that the limiting sections (minimum sections) are the sections of the inlet ports \((12 f_{3max}\) and \(12 f'_{2max})\).

Hence, any deviations from the port dimensions indicated in the drawing, in the direction of reducing them, will adversely affect the efficiency of the hammer’s operation.

4) Exaggerated height of the lower harmful space.

The existing height of the lower harmful space \(U_g = 2h_g - A = 195\) mm should be recognized as exaggerated in comparison with the normal height, which should be equal to \(U_n = 70\) mm. In view of the fact that, on the hammers investigated, the rod is connected with the ram by means of a taper, in the course of operation of the hammer a reduction in the length of the rod is possible; the latter entails a reduction of the lower harmful space. Taking this into account, the above-indicated dimension \(U_n\) is established for a run-in rod, and, in addition, it is considered necessary to carry out a systematic check of the actual height of the lower harmful space in order to prevent impacts of the piston against the lower packing gland.

5) Exaggerated air pressure above the inlet valves.

Considering the indicator diagrams (Fig. 34), it can be established that the pressure above valve 1 is high.

With the existing pressures above inlet valves 1 and 3, in order to move the control handle, the operator has to exert considerable effort. The desire to ease the operator’s work at one time led to an increase in the length of the handle.

However, the increased length of the handle created a very large travel (swing) of its end, so that although the operator has to exert less effort when working the handle, this work nevertheless requires from him more complicated and difficult movements.

As can be seen, the problem of easing the operator’s working conditions has not been fully solved.

In order for this problem to be fully solved, it is necessary to proceed along the line of creating normal clearances (0.07 mm per side) between the side—

Indicator diagrams taken with the existing settings of the operation of the steam distribution of the “Beche” 6‑t hammer, No. 2.

Graph of valve openings as a function of the handle position.

Position of the handle

No. 1 — light blow
No. 2 — strong blow
No. 3 — medium blow

Opening of valves →

Diagram of the motion of the lower inlet and upper exhaust valves in accordance with the stroke of the ram.

Indicator diagram of the upper part of the cylinder.

Indicator diagram of the lower part of the cylinder.

Scale: 1 mm = 16.375 mm.

Scale: 1 kg/cm² = 9 mm.

Fig. 34.

Fig. 35.

No. 4

Steam cylinder

Graph of changes in pressure depending on the opening of the supply valves.

Scale: \(p\) in \(\mathrm{kg/cm^2}\) \(= 6\) atm.

Labels on the small diagram:

• pressure increase
• closing
• upper valve
• lower valve
• opening

Indicated positions:

• opening of the upper valve
• closing of the upper valve
• beginning of admission
• end of admission
• \(100\%\) outlet

Additional labels:

• indicator diagrams of the upper cylinder chamber
• indicator diagrams of the lower cylinder chamber
• \(100\%\) exhaust

No. 5

Steam cylinder

Graph of changes in pressure depending on the opening of the supply valves.

Scale: \(p\) in \(\mathrm{kg/cm^2}\) \(= 6\) atm.

Labels on the small diagram:

• pressure increase
• closing
• upper valve
• lower valve
• opening

Indicated positions:

• opening of the upper valve
• closing of the upper valve
• beginning of admission
• end of admission
• \(100\%\) outlet

Additional labels:

• indicator diagrams of the upper cylinder chamber
• indicator diagrams of the lower cylinder chamber
• \(100\%\) exhaust

No. 6

Steam cylinder

Graph of changes in pressure depending on the stroke of the ram.

Scale: \(p\) in \(\mathrm{kg/cm^2}\) \(= 6\) atm.

Indicated positions:

• beginning of admission
• end of admission
• \(100\%\) outlet
• \(100\%\) exhaust

... by the end surfaces of the bushings and valves, and also along the line of selection of the summary cross-sections of the longitudinal grooves on the side surfaces of the valves.

Carrying out these measures will make it possible to reduce the air pressure over the valves and, consequently, will make it possible to create normal working conditions for the operator.

3. Results of the second test of the hammer.

By the time of the second test the adjustment had been changed; the remaining measures had not been carried out, since carrying out these measures is possible only during a major overhaul of the hammer. During the test, dies with a total height \(2h_0 = 1120\) mm were installed. (Height of the upper die \(h_0 = 505\) mm.)

Table a.

Air consumption according to indicator diagrams.

Nos. of indicator diagrams	by test	\(t^\circ C\)	\(T^\circ\)	\(w_0\), m³/kg	\(p_1\), kg/cm²	\(p_2\), kg/cm²	\(p_3\), kg/cm²	\(p_4\), kg/cm²	\(v_1\), m³/kg	\(v_2\), m³/kg	\(v_3\), m³/kg	\(v_4\), m³/kg
4	7.0	32	305	0.128	4.4	2.4	3.8	1.2	0.178	0.283	0.197	0.447
5	—	32	305	—	4.3	1.9	4.2	1.4	0.180	0.321	0.184	0.402
6	—	33	306	—	4.4	2.4	4.0	1.6	0.178	0.283	0.191	0.365

Table b.

Nos. of indicator diagrams	Lower air, \(F = 1810\) cm²: \(\varphi_u H_m\), m	Lower air, \(F = 1810\) cm²: \(\gamma H_m\), m	Lower air, \(F = 1810\) cm²: \(\gamma_1 H_m\), m	Lower air, \(F = 1810\) cm²: \(\beta_1 H_m\), m	Upper air, \(F = 2124\) cm²: \(\varphi_0 H_m\), m	Upper air, \(F = 2124\) cm²: \(\gamma H_m\), m	Upper air, \(F = 2124\) cm²: \(\gamma_1 H_m\), m	Upper air, \(F = 2124\) cm²: \(\beta_1 H_m\), m
4	0.548	1.270	0	0	0.236	1.435	0.060	0.105
5	0.563	1.315	0	0	0.246	1.410	0.065	0.130
6	0.538	1.200	0	0	0.301	1.380	0.090	0.090

Table c.

Nos. of indicator diagrams	\(V_1\), m³	\(V_2\), m³	\(V_3\), m³	\(V_4\), m³	\(Q_1\), kg	\(Q_2\), kg	\(Q_3\), kg	\(Q_4\), kg	\(Q_6\), kg	\(Q_n\), kg	\(Q\), kg	\(V_0\), m³	\(V_0/L\), m³/kg·m
4	0.329	0.099	0.355	0.085	1.85	0.35	1.80	0.43	1.37	1.50	2.87	2.35	0.00014
5	0.319	0.102	0.352	0.094	1.77	0.32	1.91	0.23	1.68	1.46	3.14	2.58	0.00014
6	0.316	0.097	0.357	0.102	1.77	0.34	1.87	0.28	1.59	1.43	3.02	2.48	0.00015

Table g.

Average force due to friction work.

Nos. of indicator diagrams	\(l\), mm	\(H_m\), m	\(\Phi_n\), mm²	\(h_n\), mm	\(p_n\), kg/cm²	\(\Phi_v\), mm²	\(h_v\), mm	\(p_v\), kg/cm²	\(P_n\), kg	\(P_v\), kg	\(P_{cb}\), kg	\(G\), kg	\(R\), kg	\(R\%\)
6	84.2	1.38	2300	27.7	4.55	250	2.9	0.49	8230	1050	7180	6500	680	10.5

Table d.

Ram speed and impact energy.

Nos. of indicator diagrams	$l$, mm	$H_m$, m	$\Phi'_v$, mm$^2$	$h'_v$, mm	$p'_v$, kg/cm$^2$	$\Phi'_n$, mm$^2$	$h'_n$, mm	$p'_n$, kg/cm$^2$	$P'_v$, kg	$P'_n$, kg	$P'_{sv}$, kg	$L'_i$, kg m	$L'_m$, kgm	$L_e$, kgm	$v$, m/sec
4	87.6	1.435	1890	21.6	3.6	530	6.05	1.01	7630	1830	5800	8300	8350	16650	7.1
5	86.1	1.410	2190	25.4	4.2	430	5.0	0.83	9000	1500	7500	10600	8200	18800	7.55
6	84.2	1.380	2010	23.9	3.9	530	6.3	1.05	8450	1900	6550	9040	8000	17040	7.16

Table zh.

Values of the coefficients characterizing the efficiency of hammer operation.

Nos. of indicator diagrams	$L_e$, kg m	$H_m$, m	$K_m$	$K_v$	$K_o$	$K_n$	$K$
4	16650	1.435	0.94	0.87	0.74	0.85	0.51
5	18800	1.41	0.95	0.90	0.80	0.83	0.57
6	17040	1.38	0.95	0.87	0.78	0.81	0.52

Comparison of the indicator diagrams showed that the character of the diagrams with the existing adjustment (Fig. 34) and with the modified adjustment (Fig. 35) is almost identical.

However, the indicator diagrams with the existing adjustment were obtained with unproductive air expenditures as a result of valve overlap. With the modified adjustment this shortcoming is eliminated.

In comparing the performance indicators of the hammer (Fig. 36) in the first and second tests, it may be noted that the following results were achieved:

1. The unproductive consumption of air was eliminated.
2. The impact energy increased by 10%.

A more complete characterization of the degree of increase in the efficiency of hammer operation, with the modified adjustments, as compared with the existing one, may be seen from the following table. (The data in the table refer to blows with the greatest energy.)

Fig. 36.

Visible labels in the figure:

• Impact energy
• Impact speed
• Test number
• Air consumption
• Specific air consumption
• Impact air cutoff angle
• $V_o$, m$^3$
• $V_i/L_e$, m$^3$/kgm
• I
• II
• 17000
• 18800
• 7.2
• 7.55
• 2.65
• 2.58
• 0.00016
• 0.00014
• 200
• 8000
• 10000
• 12000
• 14000
• 16000
• 18000
• 20000
• 0
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8

Test No.	Indicator diagram No.	Fixing dimensions of adjustment	Fixing dimensions of adjustment	Fixing dimensions of adjustment	Fixing dimensions of adjustment	Indicators	Indicators	Indicators	Indicators	Utilization coeff.	Utilization coeff.	Utilization coeff.	Utilization coeff.	Utilization coeff.
		$u_1$	$u_2$	$u_3$	$u_4$	$L_e$	$v$	$V_0$	$\dfrac{V_0}{L_e}$	$K_m$	$K$	$K_0$	$K$	$K$
1	3	96	97	125	112	17100	7.2	2.65	0.00016	0.93	0.87	0.73	0.83	0.49
2	4	107	101	113	104	16650	7.1	2.35	0.00014	0.94	0.87	0.74	0.85	0.51
3	5	100	111	112	110	18800	7.55	2.58	0.00014	0.95	0.90	0.80	0.83	0.57

Notes:
1) The methods for measuring the dimensions fixing the hammer adjustment are indicated in protocol No. 2.
2) In calculating the air consumption from indicator diagram No. 3, the following were not taken into account:
1. Air leakage through loose joints.
2. Air leakage due to improper adjustment of the hammer.

V. Conclusion.

As a result of the work carried out, it may be noted that the following changes occurred in the operation of the hammers:

1. The specific air consumptions were reduced.
2. The effective energy of the blow was increased.
3. The number of blows of the 3-ton hammer was increased.
4. Control of the 3-ton hammer was made easier.

Comparisons of the changes that took place with the results of the first test are given in the following table.

Hammers	Increase in effective blow energy, in percent of the existing value	Increase in effective blow energy, in percent of the existing value	Reduction of specific air consumption, in percent of the existing consumption	Reduction of specific air consumption, in percent of the existing consumption	Increase in the number of blows, in percent of the existing value	Increase in the number of blows, in percent of the existing value
	1st adj.	2nd adj.	1st adj.	2nd adj.	1st adj.	2nd adj.
3-ton	+53	+46	26	21	12.5	1.4
6-ton	−2.6	+10	12.5	12.5	—	—

APPENDICES

Protocols for Determining the Condition of the Forging Hammer of the Firm “Eumuco”

Weight of falling parts: 3 tons.

Inventory No. 1.

PROTOCOL No. 1

Date: November 7, 1936.

Weighing of the falling parts of the hammer and determination of the main parameters of the hammer

Procedure for determination

Fig. 10.

1. Fill in Table 1 with data from the drawings and calculate from them the values for Table 2.

2. Determine the dimensions: \(B\); \(d\); \(l\); \(2h\); \(e\) directly on the machine according to the sketch (Fig. 10).

3. Remove the upper cover of the cylinder.

4. Determine the dimensions: \(t\); \(D\); \(D_1\); \(i\).

5. Measure the distance \(H_1\) and, laying it off on the outside of the cylinder, determine \(\gamma\).

6. Weigh the falling parts (with the die) by dynamometer.

7. Lower the ram onto the spacer block and remove the dies—strikers.

8. Lower the piston onto the gland cover.

9. Measure the distance \(H_2\) and \(A\).

10. Fill in Table 2 with data calculated from the dimensions taken directly from the machine, using the formulas given (see following page).

Table 1.

	B	d	l	2h	ε	t	D	e	r/i	H₁	γ	H₂	A
According to the drawing . . .	800	180	—	—	—	—	450	—	—	—	—	—	—
In actual size . . .	800	180	2800	420	1580	190	453	125	10/40	1295	395	1435	270

Continuation of Table 1.

	l₁	g/p	l″	c/m	l‴	lᵤ′	lᵤ″	a/b	lᵤ‴
According to the drawing . . .	62.5	230/45	662.5	230/45	157.5	62.5	902.5	230/45	157.5
In actual size . . .	—	—	—	—	—	—	—	—	—

Processing of the results.

\[ k=\varepsilon+\gamma-e=1580+395-125=1850\ \text{mm}. \]

\[ H_{\mathrm{d}}=H_1-t=1285-190=1095\ \text{mm}. \]

\[ H_{\max}=H_2-t=1435-190=1245\ \text{mm}. \]

\[ F=\frac{\pi\cdot D^2}{4}=\frac{3{,}14\cdot45{,}3^2}{4}=1611\ \text{cm}^2. \]

\[ \alpha F=\frac{\pi\cdot(D^2-d^2)}{4} =\frac{3{,}14\,(45{,}3^2-18{,}0^2)}{4}=1356\ \text{cm}^2. \]

\[ \alpha=\frac{\alpha F}{F}=\frac{1356}{1611}=0{,}842. \]

\[ v_0=l'(g\cdot p)+l''(c\cdot m)+l'''(g\cdot p) =6{,}25(23{,}0\times4{,}5)+66{,}25(23{,}0\times4{,}5)+ \]

\[ +15{,}75(23{,}0\times4{,}5)=647+6857+1630=9134\ \text{cm}^3. \]

\[ v_0=F\cdot t-(F_{\mathrm{buf}})=1611\cdot20-(F_{\mathrm{buf}}) =32220-7410=24810\ \text{cm}^3. \]

\[ v_{0k}=7400\ \text{cm}^3. \]

\[ Y_0=v_0+V_0+v_{0k}=9134+24810+7400=41344\ \text{cm}^3. \]

\[ v_{\mathrm{u}}=(g\cdot p)l_{\mathrm{u}}'+l_{\mathrm{u}}''(a\cdot b)+l_{\mathrm{u}}'''(g\cdot p) =6{,}25(23{,}0\times4{,}5)+ \]

\[ +90{,}25(23\times4{,}5)+15{,}75(23\times4{,}5)=11618\ \text{cm}^3. \]

\[ Y_{2h\mathrm{d}}=(2h_{\mathrm{d}}-A)\alpha F=(42{,}0-27{,}0)=15\cdot1356=20340\ \text{cm}^3. \]

\[ v_{0k}=7400\ \text{cm}^3. \]

\[ Y_{2h\mathrm{d}}=v_{\mathrm{u}}+v_{2h\mathrm{d}}+v_{\mathrm{uk}} =11618+20340+7400=39358\ \text{cm}^3. \]

Table 2.

	G	R	F	αF	α	H₀	K	Hmax	Hд
According to the drawing . . .	3010	—	1590	—	—	1690	1795	—	—
In actual size . . .	3000	—	1611	1356	0.842	1690	1850	1245	1095

Continuation of Table 2.

	\(2h_0\)	\(v_0\)	\(V_0\)	\(v_{ok}\)	\(Y_0\)	\(v_a\)	\(V_{2h0}\)	\(v_{uk}\)	\(Y_{2h0}\)
According to drawing . . .	—	9134	24810	7400	71374	11618	20340	7400	39358
In kind . . . .	420	—	—	—	—	—	—	—	—

Supervisor ____

The determination was performed ____

Plant representative ____

PROTOCOL No. 2.

Date: November 9, 1936.

Determination of the characteristics of the distributing mechanism.

Procedure for determination.

1. Determine the dimensions of Table 1 (Fig. 11) and Table 2 (Fig. 12) in kind and according to the drawings.

2. Mark off the full travel of the control handle along the sector into 8 equal divisions, in accordance with Fig. 11.

Note. If there is no handle sector, install one.

1. Determine the relative position of the links of the distributing mechanism with the link \(d\) horizontal (crosshead, link block—Fig. 11).

2. Record the existing adjustment of the hammer according to Table 2 and Fig. 12.

3. Establish the law of displacement of valves 1, 2, 3, and 4 (Table 4) as a function of the displacement of the handle, recording the dimensions \(y_1, y_2, y_3, y_4\) (Fig. 13) at each division of the sector.

4. Determine the position of the handle on the sector corresponding to the moment of lift of the exhaust and working valves (Table 5).

5. On the basis of the obtained Tables 4 and 5, plot a graph of valve displacement as a function of the motion of the handle.

Fig. 11.

When link \(d\) is horizontal, the handle is located at 3.5 divisions of the sector.

Table 1.

	\(a\)	\(b\)	\(c\)	\(k\)	\(l\)	\(i\)	\(d\)	\(e\)	\(g\)	\(s\)
According to drawing	1375	275	—	110	—	—	300	85	150	135
As built	1375	275	85	115	2515	60	300	85	150	135

Table 2.

Valve No.	\(u\)
1	—
2	—
3	—
4	—

View along arrow A.

Fig. 12.

Table 3.

Valve		\(p\)	\(o\)	\(m\)	\(n\)	\(a\)	\(\lambda\)	\(h/f\)	\(\delta\)	\(\omega\)	\(\varepsilon\)	\(D_1\)	\(D_2\)	\(\dfrac{D_1-D_2}{2}\)
1st valve, upper inlet	According to drawing	143	95	55	40	22	4	35/30	—	25	25	130	130	—
1st valve, upper inlet	As built	143	95	55	40	22	3	—	—	26	26	—	—	0.5
2nd valve, upper exhaust	According to drawing	143	95	55	40	22	—	35/30	—	25	25	130	130	—
2nd valve, upper exhaust	As built	143	95	55	40	22	—	—	—	—	—	—	—	0.5
3rd valve, lower inlet	According to drawing	143	95	55	40	22	4	35/30	—	25	25	130	130	—
3rd valve, lower inlet	As built	143	95	55	40	22	4	—	—	26	24	—	—	0.5
4th valve, lower exhaust	According to drawing	143	95	55	40	22	—	35/30	—	25	25	130	130	—
4th valve, lower exhaust	As built	143	95	55	40	22	—	—	—	—	—	—	—	0.5

Number of ports for valves 1 and 3—10 pcs.
Number of ports for valves 2 and 4—10 pcs.

When raising the handle.

Table 4.

Handle position	Valve 1: \(y\)	Valve 1: valve travel	Valve 2: \(y\)	Valve 2: valve travel	Valve 3: \(y\)	Valve 3: valve travel	Valve 4: \(y\)	Valve 4: valve travel
0	22	13	304	0	35	0	287	17
1	25	10	304	0	35	0	291	13
2	30	5	304	0	35	0	296	8
3	35	0	304	0	35	0	300	4
4	35	0	304	0	35	0	304	0
5	35	0	299	5	33	2	304	0
6	35	0	290	14	30	5	304	0
7	35	0	283	21	25	10	304	0
8	35	0	279	25	23	12	304	0

Table 4-a.

When lowering the handle.

Handle position	Valve 1: \(y\)	Valve 1: valve travel	Valve 2: \(y\)	Valve 2: valve travel	Valve 3: \(y\)	Valve 3: valve travel	Valve 4: \(y\)	Valve 4: valve travel
8	—	—	—	—	—	—	—	—
7	—	—	—	—	—	—	—	—
6	—	—	—	—	—	—	—	—
5	—	—	—	—	—	—	—	—
4	—	—	—	—	—	—	—	—
3	—	—	—	—	—	—	—	—
2	—	—	—	—	—	—	—	—
1	—	—	—	—	—	—	—	—
0	—	—	—	—	—	—	—	—

Fig. 13.

Table 5.

Valve Nos.	Unloading valve: \(t_0\)	Unloading valve: \(t_1\)	Unloading valve: \(t_2\)	Unloading valve: handle position corresponding to \(t_1\)	Working valve: \(y_1\)	Working valve: \(y_2\)	Working valve: handle position corresponding to [[unclear: heading]]	Working valve: travel of unloading valve
1	—	—	—	4,0	—	—	3,0	3
2	—	—	—	0,0	—	—	4,10	—
3	—	—	—	0,5	—	—	4,30	4
4	—	—	—	4,50	—	—	3,40	—

Table 6. “\(x\)”

When raising the handle

Handle position	Valve 1	Valve 2	Valve 3	Valve 4
0	28	16	6	27
1	—	—	—	—
2	17	10	11	20
3	10	3	15	12
4	3	51	20	3
5	0	10	22	−5
6	0	18	25	−5
7	0	27	29	−5
8	0	35	32	−5

Table 6-a. “\(x\)”

When lowering the handle

Handle position	Valve 1	Valve 2	Valve 3	Valve 4
8	—	—	—	—
7	—	—	—	—
6	—	—	—	—
5	—	—	—	—
4	—	—	—	—
3	—	—	—	—
2	—	—	—	—
1	—	—	—	—
0	—	—	—	—

Fig. 14.

Graph of port opening \(b\) as a function of the handle position.

Fig. 15.

Supervisor ____

Determination performed by ____

Representative of the plant ____

Records for Determining the Condition of the Forging Hammer of the Firm “Eumuco”

Weight of falling parts: 6 tons.

Inventory No. 2.

RECORD No. 1.

Date: January 2, 1937.

Weighing the falling parts of the hammer and determining the basic parameters of the hammer.

Fig. 16.

Procedure for determination.

1. Fill in Table 1 with data from the drawings and calculate from them the values for Table 2.

2. Determine the dimensions: \(B; d; l; 2h; \varepsilon\) in situ, according to the sketch in Fig. 16.

3. Remove the upper cover of the cylinder.

4. Determine the dimensions: \(t; D; i\).

5. Measure the distance \(H_1\) and, subtracting it from the outside of the cylinder, determine \(\gamma\).

6. Weigh the falling parts (with the die) using a dynamometer.

7. Lower the ram onto a spacer and remove the dies—strikers.

8. Lower the piston onto the gland cover.

9. Measure the distance \(H_2\) and \(A\).

10. Fill in Table 2 with the data calculated from the dimensions taken in situ, using the formulas given (see next page).

Table 1.

| | \multicolumn{5}{c}{Determined at any moment} | \multicolumn{6}{c}{Determined with cover removed} | \multicolumn{2}{c}{Without die} |
|---|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|
| | \(B\) | \(d\) | \(l\) | \(2h\) | \(\varepsilon\) | \(t\) | \(D\) | \(e\) | \(r/i\) | \(H_1\) | \(\gamma\) | \(H_2\) | \(A\) |
| According to drawing . . . | 1000 | 200 | — | — | — | 110 | 520 | 150 | 35/35 | — | — | 1990 | — |
| In situ . . . | 1000 | 200 | 4280 | 1140 | 2140 | 110 | 520 | 150 | 35/35 | 1645 | 380 | 1990 | 945 |

Continuation of Table 1.

Determination from the drawings

	\(l'\)	\(g/p\)	\(l''\)	\(c/m\)	\(l'''\)	\(l_u'\)	\(l_u''\)	\(a/b\)	\(l_u'''\)
According to the drawing . . .	—	170/140	925	270/65	222	1200	—	—	222
From actual measurements . . .	—	—	—	—	—	—	—	—	—

Processing of the results.

\[ k=\gamma+\varepsilon-e+170=380+2140-150+170=2540\ \text{mm}. \]

\[ H_0=H_1-t-r=1645-110-35=1500\ \text{mm}. \]

\[ H_{\max}=H_2-t-e-r=1990-110-150-35=1695\ \text{mm}. \]

\[ F=\frac{\pi D^2}{4}=\frac{3{,}14\cdot 52^2}{4}=2124\ \text{cm}^2. \]

\[ \alpha F=\frac{\pi(D^2-d^2)}{4} =\frac{3{,}14\cdot(52^2-20^2)}{4} =1810\ \text{cm}^2;\qquad \alpha=\frac{\alpha F}{F}=\frac{1810}{2124}=0{,}852 \]

\[ v_0=l'''(g\cdot p)+l''(c\cdot m) =22{,}2(17\times 14)+92{,}5(27\times 6{,}5) =21500\ \text{cm}^3. \]

\[ V_0=t\cdot F=11\cdot 2124=23400\ \text{cm}^3. \]

\[ v_{0k}=2550\ \text{cm}^3. \]

\[ Y_0=v_0+V_0+v_{0k}=21500+23400+25500=70400\ \text{cm}^3. \]

\[ v_n=l_u'''(p\cdot g)+l_u(c\cdot m) =22{,}2(14\times 17)+120(27{,}0\times 6{,}5)=26300\ \text{cm}^3. \]

\[ V2h_0=(2h_0-A)\cdot \alpha F+v_n^{*})=39600\ \text{cm}^3. \]

\[ v_{uk}=24200\ \text{cm}^3. \]

\[ Y2h_0=v_n+V2h_0+v_{uk}=26300+39600+24200=90100\ \text{cm}^3. \]

Table 2.

	\(G\)	\(R\)	\(F\)	\(\alpha F\)	\(\alpha\)	\(H_0\)	\(K\)	\(H_{\max}\)	\(H_0\)
According to the drawing . . .	6550	—	2124	1810	0,852	2050	—	1695	—
From actual measurements . . .	—	820	2124	1810	0,852	2050	2540	1695	1500

Continuation of Table 2.

	\(2h_0\)	\(v_0\)	\(V_0\)	\(v_{0k}\)	\(Y_0\)	\(v_n\)	\(V2h_0\)	\(v_{uk}\)	\(Y2h_0\)
According to the drawing . . .	—	21500	23400	25500	70400	26300	39600	24200	90100
From actual measurements . . .	1140	—	—	—	—	—	—	—	—

Supervisor ____

The determination was made by ____

Representative of the plant ____

*) Volume of the piston cavity (see piston drawing) \(v_n=4600\ \text{cm}^3\).

PROTOCOL No. 2.

Date: January 10, 1937.

Determination of the Characteristic of the Distribution Mechanism

Fig. 17.

Procedure for determination.

1. Determine the dimensions of Table 1 (Fig. 17) and Table 2 (Fig. 18) from the actual object and from the drawings.

2. Mark off the full travel of the control handle along the sector into 8 equal divisions according to Fig. 17.

Note. In the absence of the handle sector, install it.

1. Determine the relative arrangement of the links of the distribution mechanism when link $d$ is in the horizontal position (crosshead, rocker, Fig. 17).

2. Record the existing adjustment of the hammer according to Table 2 and Fig. 18.

3. Establish the law of displacement of valves 1, 2, 3, and 4 (Table 4) as a function of the displacement of the handle, recording dimensions $y_1$ (Fig. 19) at each division of the sector.

4. Determine the position of the handle on the sector corresponding to the moment of lifting of the exhaust and working valves (Table 5).

5. On the basis of Tables 4 and 5, plot the graph of valve displacement as a function of the motion of the handle (Fig. 21).

With link $d$ in the horizontal position, the handle is located at 3.5 divisions of the sector.

Table 1.

	$a$	$b$	$l$	$i$	$d$
According to drawing	1550	150	—	—	150
From actual object	1900	160	4510	62	150

Table 2.

Valve No.	$u$
1	96
2	97
3	125
4	112

Fig. 18.
View along arrow “A”.

Table 3.

Valve	Measurement	\(p\)	\(o\)	\(n\)	\(\lambda\)	\(n/f\)	\(\omega\)	\(\varepsilon\)	\(D_1\)	\(D_2\)	\(\dfrac{D_1-D_2}{2}\)
1st valve, upper admission	By drawing	380	51	152.5	5	40/36	51	50	150	150	—
1st valve, upper admission	In kind	376	51	—	6	25/28	52	—	150	150	0.3
2nd valve, upper admission	By drawing	380	51	152.5	5	30/26	51	50	120	120	—
2nd valve, upper admission	In kind	380	52	—	6	28/25	52	—	119	118	0.5
3rd valve, lower exhaust	By drawing	380	51	152.5	5	30/26	51	50	120	120	—
3rd valve, lower exhaust	In kind	377	51	—	6	25/25	52	—	120	120	0.3
4th valve, lower exhaust	By drawing	380	51	152.5	5	40/36	51	50	150	150	—
4th valve, lower exhaust	In kind	376	52	—	6	28/29	52	—	151	150	0.5

Number of ports for valves 1 and 3 — 12 pcs.
Number of ports for valves 2 and 4 — 12 pcs.

With lifting of the handle.

Table 4.

Handle position	Valve 1 \(y\)	Valve 1 stroke	Valve 2 \(y\)	Valve 2 stroke	Valve 3 \(y\)	Valve 3 stroke	Valve 4 \(y\)	Valve 4 stroke
0	35	29	61	0	62	0	17	45
1	46	18	61	0	62	0	30	32
2	59	5	61	0	57	5	42	20
3	64	0	61	0	47	15	53	9
4	64	0	61	0	41	21	62	0
5	64	0	59	2	38	24	62	0
6	64	0	49	12	28	34	62	0
7	64	0	38	23	15	47	62	0
8	64	0	30	31	8	54	62	0

Table 4-a.

When lowering the handle.

Handle position	Valve No. 1 — $y$	Valve No. 1 — valve travel	Valve No. 2 — $y$	Valve No. 2 — valve travel	Valve No. 3 — $y$	Valve No. 3 — valve travel	Valve No. 4 — $y$	Valve No. 4 — valve travel
8	64	0	30	31	8	54	62	0
7	64	0	38	23	18	44	62	0
6	64	0	49	12	28	34	62	0
5	64	0	60	1	36	26	62	0
4	64	0	61	0	39	23	62	0
3	64	0	61	0	47	15	51	3
2	58	6	61	0	58	4	40	12
1	45	19	61	0	62	0	29	33
0	33	31	61	0	62	0	19	43

Fig. 19.

Table 5.

Valve Nos.	Unloading valve — $t_0$	Unloading valve — $t_1$	Unloading valve — $t_2$	Unloading valve — corresponding handle position	Working valve — $y_1$	Working valve — $y_2$	Working valve — corresponding handle position $y_2$	Travel of unloading valve $\lambda$
1	75	—	69	4,30	—	64	2,35	6
2	74	—	69	4,10	—	61	4,45	5
3	77	—	71	0,10	—	62	1,35	6
4	74	—	68	4,45	—	62	4,10	6

Table 6. “x”

When raising the handle.

Handle position	Valve No. 1	Valve No. 2	Valve No. 3	Valve No. 4
0	74	45	10	81
1	62	26	20	68
2	49	38	28	56
3	42	45	38	45
4	41	45	46	35
5	37	49	47	35
6	26	60	59	21
7	15	72	70	14
8	9	79	78	8

Fig. 20.

Table 6-a. “x”

When lowering the handle.

Handle position	Valve No. 1	Valve No. 2	Valve No. 3	Valve No. 4
8	9	79	78	8
7	15	69	70	14
6	26	58	59	25
5	37	48	48	35
4	39	46	46	36
3	42	42	38	46
2	50	36	27	58
1	63	24	19	68
0	75	13	10	80

Fig. 21.

Labels in the figure:

• mm
• Opening
• Closing
• lower exhaust
• lower inlet
• upper exhaust
• upper inlet
• Lift of the working valve
• Lift of the air valve
• handle position

Supervisor ________

The determination was performed by ________

Plant representative ________

1. See the appendix and Figures 10–20. ↩↩↩