US3098402A - Forging machine - Google Patents

Description

July 23, 1963 B. KRALowETz 3,098,402-

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FoRGING MACHINE Filed March 14, 1961 6 Sheets-Sheet 6 Iwusrvfom ,figc/Nalgene wf'rL www United States Patent O tiEAZ ldlRGlNG MACHNE Bruno Kralowetz, St. Ulrich, near Steyr, Austria Filed Mar. 14, i961, Ser. No. 95,559 Claims priority, application Austria Mar. 1S, 1960 9 creams. (ci. 1a- 20) This invention relates to a forging machine which comprises hammers consisting of connecting rods and driven by eccentric shafts eccentrically mounted in angularly adjustable housings, and hydraulic working pistons for the longitudinal movement of the workpiece and for the angular adjustment of the bearing housings, which working pistons have associated with them two stepping rollers coupled for rotation in unison. The rollers are stepped forward at the end of the respective Working piston movement and by such forward step act on a valve system for automatically controlling the working pistons. The eccentric shafts for driving the connecting rod-like hammers being eccentricall'y arranged in their bearing housings, the angular adjustment of these bearing housings will change the stroke position of the connecting rods and with it the respective depth of penetration of the hammers into the workpiece. The working piston which causes the angular adjustment of the bearing housings controls the radial dimensions of the workpiece whereas the other working piston, which causes the longitudinal movement of the workpiece controls the respective length dimensions.

Stop discs connected for rotation with the stepping rollers have previously lbeen provided and stop members may be selectively secured to these discs. Each of these stop discs supports a valve by means of a feeler lever or the like. rhe valve is hydraulically urged against the disc. Depending on the height of the stop members, the valve will be displaced through different distances, This displacement of the valve will cause the application of hydraulic pressure to the Working pistons in one sense or the other. As each angular movement of the stepping rollers causes another stop member to be moved to its operative position, the stepping roller will be rotated by the Working piston at the end of its movement to change the valve system in such a manner that the desired sequence of operations will be obtained. It has now been found that the setting up of the stop discs for the desired sequence of operations, i.e., the selection land mounting of the required stop members and the change in the positions thereof, is a complicated, time-consuming operation which requires extreme attention and that relatively complex valve structures are required, particularly because it is not suicient to eiect a reversal of the movement, but a flow through a throttle may also be required.

It `is an object of the invention to improve the forging machine described hereinbefore in this respect so that the setting up for a desired sequence of operations is simplified.

The valve system of the invention comprises a common rotary valve, to which a stepping movement is imparted by one of the stepping rolls, and preaadjustable pairs of control valves corresponding in number to the positions of the stepping rollers and of the rotary valve. One of the control valves of each pair controls the application of hydraulic pressure to one working piston and the other control valve controls the application of hydraulic pressure to the other working piston, whereas the rotary valve connects in each of its positions the conduits of the cylinders of the working pistons to one pair of control valves. The control valves yare arranged to connect said conduits to the pressure fluid supply conduit or to the drain conduit or for shutting oit the cylinder conduits ice entirely. Thus, in each position of the stepping rollers and rotary valve, another pair of control valves will determine the application yof pressure to the working pistons and it is suficient to move the control valves into the position which corresponds to the desired operation. Instead of the time-consuming setting up of two stop` dises previously required, it `is now sufiicient to adjust two control valves for each position of the control roller and rotary 'valve in such a manner that lthe desired working piston movement will be effected. A simple inscription is suilicient to avoid errors in setting up and a special tool is not required for adjusting the valves.

In order to enable a pre-setting not only of the direction of movement but also of the speed of the working pistons, a throttle may tbe associated with each control valve. The control valve and throttle are preferably combined in a unit. The control valves are preferably plug valves and an independently rotatable throttle member is coaxially mounted in the valve plug. Depending on the position of the throttle, the working piston movement is accelerated or delayed so that the entire sequence of operations can be pre-set with the aid of the throttles. Since the plug valves and the throttle members are coaxially mounted, the adjustment is limited to two rotary H movements which can be performed quickly and Without diiculty.

The control valves may be accommodated in a common block and disposed in two concentric circles around the rotary valve, the valu/es of each pair lying preferably in a common radial plane. This will result in a clearly arranged and space-saving design. The central valve may be provided with a pointer which will indicate the operating pair of control valves. It is possible to change the operations while the machine is running. This would not have been possible, of course, with the known stop discs.

A particular simpliiication of the entire hydraulic system can be achieved if only the cover-side conduits of the working piston cylinders pass through the rotary valve and control valves whereas pressure is permanently applied in a known manner to the rod side of the working pistons. In this case it is sufficient to eiect changes in connections on the cover side of the cylinders and the design of the con-trol valves and the rotary valve can be simplified. Nevertheless the Working pistons Ican be moved in both directions because the effective piston area is smaller on the rod side than on the cover side.

For the angular movement of the stepping rollers, there is provided a separate hydraulic piston drive, which is controlled by a magnetic valve. The magnetic valve is energized by a limit switch operable by a cam wheel which rotates with the control rollers. 'Ihe working pistons cause only a short rotation of the rollers for generating a control impulse at the end of the piston movement. This results in a substantial simpliiication as compared to known devices As soon as one of the working pistons .impinges on one of the stepping roller stops, the stepping rollers are rotated by a small amount. 'Ihis rotation is sucient, however, to operate the limit switch, which will then `displace the magnetic valve so that the piston `drive is operated to rotate the stepping rollers. The displaceable part of the piston drive may be a rack in mesh with a pinion, which by a ratchet coupling is coupled to one of the stepping rollers. At the end of the rotation of the stepping rollers this pinion will operate an additional limit switch for resetting the magnetic valve.

When the forging cycles available are not fully utilized so that the work is completed before the stepping rollers return to their initial position provision must be made that the rotation of the stepping rollers is continued to the initial position even though there is no impulse-generating working piston movement. To this end, a second disc,

which is provided with detachable cams and rotates with the stepping rollers, and an additional limit switch operated by the detachable earns are provided for displacing the magnetic valve. The operation of this limit switch due to an appropriate cam position will cause a displacement of the magnetic valve to rotate the stepping roller so that the stepping movement is continued without action of the working pistons.

A movement of one working piston is usually followed by another working piston movement, due to the further rotation of the stepping rollers. It may be desirable to work for a longer time without a longitudinal movement of the workpiece and with the hammers set to the same depth, e.g., for an exact forging of collars. In such case, the succession of the working piston movements must be delayed. This is only possible if the further stepping of the stepping rollers and of the rotary valve at the end of the preceding working piston movement is delayed. The invention therefore provides a time limit relay for the magnetic valve, which relay is selectively operable in each position of the stepping rollers and rotary valve. A feller pin is preferably slidably mounted in the rotary valve and is urged radially outwardly by a spring against rotatable stops by spring force. According to `the stop position the pin acts by means of a linkage on a limit switch of the time limit relay. Thus, any desired interval between the forging cycles may be preset by rotation of stops at the block which encloses the rotary valve, the control valves and the throttles.

An illustrative embodiment of the invention is shown in the accompanying drawings, in which `FIG. 1 is an elevation view of the entire machine;

FIG. 2 is a top plan view of the hammer drive;

FIG. 3 a sectional view taken on line III-III of FIG. 1 and showing the piston drive for rotating the stepping rollers on a larger scale;

FIG. 4 is a diagram of the corresponding hydraulic system;

FIG. 5 is a sectional view taken on line V-V of FIG. 1, also on a larger scale;

FIG. 6 is a radially sectional view of the block which encloses the rotary valve and the control valves;

FIG. 7 shows the block in fragmentary elevation and FIG. 8 is a diagram of the hydraulic system for controlling the working piston.

Four hammers 1 constituting connecting rods are horizontally guided in the forging box not shown in detail. The shafts 2 driving said hammers are eccentrically mounted in rotatably adjustable housings. Each of these bearing housings, which are rotatable in the forging box, comprises a gear rim 3, which is in mesh with a central gear 4. By rotating this central gear, the distance of the driving shaft axes from the workpiece axis and thus the stroke position of the connecting rod-like hammers will vary owing to the eccentric mounting of the drive shafts 2 in the housings so that the depth of the penetration of the hammers into the workpiece and the corresponding radial dimension of hte workpiece can be adjusted by an appropriate rotation of the central gear. To effect this adjustment, a working piston 5 is provided, the piston rod 6 of which carries a rack 7 By means of several pinions 8, the movement of the piston or rack is transmitted to the central gear 4 and from the latter by the gear rims 3 to the bearing housings of the driving eccentric shafts 2.

The workpiece is held by a gripping head 9, which is vertically slidably guided in the machine frame and which may impart to the workpiece a rotary movement about its axis, if desired. The gripping head 9 is moved up and down with the aid of an additional working piston 10. The cylinders of the two working pistons 'are designated l11 and 12.

`Each of the two pistons 5 and 10 is Iassociated with a stepping roller 13, 14. The rollers 13, 14 are parallel to the direction of movement of the respective piston and are coupled for rotation in unison by a pair of helical gears 4 15. Limit stops 16, 17 are longitudinally adjustably secured to the stepping rollers 13, 14 on generatrices thereof which correspond to the steps of the movement of the rollers, The limit stops 16, 17 have an inclined run-up surface 18 and the pistons 5, 10, the racks 7 and the gripping head 9 are provided with rollers 19 which act on the stops. The machine described thus far corresponds to the known forging machines of the present type.

When one of the rollers 19 impinges on the run-up face 13 of one of the limit stops 16 or 17, the inclination of this face will result in a small angular movement of the stepping roller. This `angular movement does not correspond to a complete step of the stepping roller but only initiates such step. The stepping roller 13 is con nected for rotation in unison to a `camwheel 20, which operates a limit switch 21 as soon as the short angular movement of the stepping roller is effected by the run-up -face of the stops. As seen in FIG. 5 a bell-crank lever 23 having a feeler roller 24 is provided, which is biased by a spring 22 and bears on the camwheel 2t) and with its back acts on the operating lever 25 of the limit switch 21. With the aid of an eccentric lever 26 the limit switch 21 can be pressed by hand, independently of the rotation of the stepping roller. The limit switch 21 controls a magnetic valve 27, which controls the application of hydraulic pressure to a piston drive consisting of a cylinder Ztl and a piston 29` formed with a rack.

The shaft of the stepping roller 13 carries a freely rotatable gear 30, which is coupled to the stepping roller in one direction of rotation by a ratchet coupling 31. When Ithe limit switch 21 is operated during the short angular movement of the stepping -roller by the impact of one of the rollers 19 on one of the stops 16 or 17, the magnetic valve 27 will assume the position shown in FIG. 4, in which pressure oil from the pressure conduit 32 can ow through conduit 33 to the left-hand end of the cylinder 28 whereas the right-hand end of the cylinder is connected by the conduit 34 to the drain 35. As a result, the piston 29 is moved to the right and the gear 30 is rotated in a oounterclockwise direction and drives the stepping roller by means of the ratchet coupling 31. At the end of this angular movement a stop member 36 engages a limit switch 37, which returns the magnetic valve 27 to that position in which the conduit 33 is connected to the drain and the conduit 34 is connected to the pressure uid supply conduit so that the piston 29 and the gear 30 perform the opposite movement. The ratchet coupling 31 Adoes not transmit this movement to the stepping rollers.

The limit switch 21 energizes an additional magnetic valve 38 (FIG. l), which controls the application of pressure to the pistonlike displaeeable part of the ratchet coupling 31 so that pressure is applied to the pistonlike ratchet part during a rotation in the forward stepping sense whereas it is pressure-relieved during the resetting movement. The limit switch 37 also resets the magnetic valve 38. Another limit switch 39, which is also operable by the gear 30, is a safety device. In the event of impulses succeeding each other at intervals shorter than those required for the stepping operation the switch 39 operates in such a manner that the piston 29 will return to its end position and the ratchet coupling 31 will be locked again before the next stepping movement.

A rotary valve 42 is coupled by a pair of gears 40, 41 to the stepping roller 13 and is centrally disposed in a block 43, in which control valves 44, 45 are accommodated in two concentric circles. A pair of control valves is associated with each position of the stepping roller and rotary valve. The valves of each pair lie in one radial plane. The valves 44 disposed on the outer circle control the application of hydraulic pressure to the working piston 10 for the gripping head 9. The values 45 of the inner circle are associated with the working piston 5 for setting the hammers. The valves 44, 45 are plug valvesf An independently rotatable throttle member 47 is coaxially mounted in each valve plug 46. As is apparent from FIG. 8, pressure is permanently applied to the working pistons 5 and 10 on their rod side from vthe conduit 48 land the conduits 49 and 5t). From the cover side of the cylinder 11 a conduit 51, 52 extends to the rotary valve 42 and from the same through bores 53, 54 to the operative control valve 45. In the position shown in FIG. 8 this control valve 45 establishes a connection through conduit 5S to the oil drain 56. Oil under pressure is suppl-ied to conduit 4S by a pump 76 from a container 77, into which the oil from drain 56 is returned. Because the cover side of the cylinder 11 is yconnected to the drain whereas the rod side receives pressure oil, the piston 5 moves to the right, as viewed in FIG. 8, and the hammers open. This opening movement of the hammers is slow because the throttle member `47 obstructs a large part of the outlet opening lof the plug 46. If the valve plug 46 of the illustrated control valve 45 is rotated by 180, pressure oil ows from conduit 48 through conduit 57, the bores 53, 54, and the conduits 52 and 51 to the cover side of the cylinder 11. Since the effective piston area is much larger yon the cover side than ton the rod side, the piston 5 moves in the opposite direction and the oil on the rod side is discharged through the conduit system.

rI`he conduit 58 from the cover side of the cylinder 12 is also connected to the drain through the conduit 59, the bores 60 and |61 and the control vve 44 and the conduit 62 so that the working piston 10` moves upwardly, as seen in FIG. 8, under fluid pressure applied to the rod side. Depending on the position of the throttle member 47 relative to the valve plug y46K, the speed of this movement will be low or high. Upon rotation of the plug of the valve 44 through 180 a connection of the cover side of the cylinder 12 to the pressure conduit 48, 57 is established, so that the piston 10, the gripping head 9 and the workpiece descend. It is apparent that a rotation of the valve plugs of the valves 44 and 45 through only 90 degrees will shutoff the conduits leading to the cover sides of the cylinders 111, 12 so that the working pistons 5 and 1th are at a standstill.

In each position of the stepping rollers, the rotary valve 42 connects the cover side conduits o-f the cylinders lil, 11 to a different pair of control valves 44, 45 and these can be preset, by a simple rotation of the valve plug, to cause any desired sequence of Working piston movements. The speed `of the work-ing piston movement resulting from the respective control valve position can be predetermined by means of the throttle members, and any desired working program can therefore be preset at the block 43. A suitable inscription is provided for the position of the plug valve 46 and of the throttle member 47 so that the setting up does not involve any diiculty. The rotary valve has a radial pointer 63 (FIG. 7), which indicates the pair of control valves which are operative in each stepping roller and rotary valve position. FIG. 8 shows also manually adjustable valves 64, 65 with associated throttles 66, 67. These are emergency valves, which enable the establishment of a direct connection from the cover side of the cylinders 11, 12 to the drain so that a movement of the valves will immediately cause an opening of the hammers or an upward movement of the gripping head and workpiece.

The entire forging p-rogram is started by hand with the aid of a limit switch, not shown, which is connected in parallel to the limit switch 21 and actuates the magnetic valve 27, the piston drive 29, 60 and the ratchet 3x1 so as to initiate the lfirst stepping movement .of the stepping rollers. The shaft of the stepping roller 13 carries a second disc 68 provided with detachable cams. A camwheel rotating in unison with a stepping roller and carrying detachable cams is disclosed in the U.S. patent specification No. 2,793,548, particularly in FIGS. 2, 6 and 7 thereof. By this reference thereto, said patent specification is included in the present disclosure. A limit switch 69 is provided which is operated by the detaehably mounted cams and controls the energization of the magnetic valve 27. When operated by the cams, the limit switch 69 causes the magnetic valve 27 to assume the position shown in FIG. 4, in which the valve 27 causes the stepping -roller to be rotated by the rack piston 29, the gear Sti and the ratchet coupling 31, as has been described hereinhefore. This arrangement serves to ensure the return of the stepping rollers and off the rotary valve to the initial position when the working program has been completed beore the stepping roller and rotary valve have reached their end position, i.e., when the angular positions and forging cycles available are not all utilized and the working pistons do no longer generate impulses for the continued rotation to the final or initial position. in this case the continued rotation through the remaining cycles is effected with the aid of the stop members on the disc 68 and of the limit switch 69'.

To delay the stepping from one stepping noller and rotary valve position to the next, in order to enable a prolonged ifo-rging at the same point of the workpiece, eg., for an exact forging of collars, a time limit relay 70 can be connected to the limit switch 2 1 and with the normally open contact of this relay interposed between the limit switch and the magnetic valve. Thus the response of the valve 27 to the operation of switch 21 is delayed lfor a predetermined period of time so that the hammers can work during this time delay without a change of the axial position of the workpiece and without a change of the depth setting of the hammers. A radial feeler pin 71 is displacea-bly mounted in the rotary valve y42 and zby a bell-crank lever 72 and a rod 73 engages a switch combined with the relay 70 and operable to connect it to the limit switch 21. Its normally open contact is interposed between the switch 21 and valve 27. A spring 74 urges the ieeler pin 71 radially outwardly. Angularly adjustable stops 75 are carried by the block 43 with a spacing which corresponds to the stepping angles. Depending on the position of these stops '75, the feeler pin '71 is displaced radially inwardly so that the switch of relay 70 is actuated by the linkage 72, 713, or the `feeler pin remains in its position to which it is urged outwardly by the spring 74 and does not act on the switch of relay 70X. The angular adjustment o-f the stops 75 enables -diiierent `faces of the stops to be presented to the feeler pin 71 so as to engage or clear the same (FIG. 7). Thus, the ent-ire operation, i.e., the direction and speed of the movements of the working pistons in each control position and the so-called collar 'delay can be preset at the block 43 by a simple rotation of the valve plugs 46 and tof the throttle members 47 and stops 'l5 and it is sufficient to determine the workpiece diameters and the desired =forging lengths with the aid of the stops 16 and 17 on the stepping rollers 13, 14.

What 4I claim is:

l. A forging machine which comprises hammers -formed las connecting rods, eccentric shafts operable to drive said hammers, angularly adjustable housings eccentrcally mounting said shafts, workpiece feed means, a irst hydraulic setting piston operable to axially move said workpiece feed means, a second hydraulic setting piston operable to eiect an angular movement of said housings, iirst and second control conduits adapted to apply hydraulic pressure to said iirst and second pistons, respectively, two stepping rollers Iwhich are coupled for joint rotation to a plurality of predetermined positions and associated each with one of said pistons and arranged to perform an angular movement to the next of said predetermined positions in response to the completion of a movement of one of said pistons, and a valve system arranged to control said setting pistons in dependence on the. position of said stepping rollers, said valve system. compr-ismg a common rotary valve arranged to be moved by said stepping rollers to a plurality of positions corresponding to said positions of said stepping rollers, a plurality of pairs of control valves, each of said pairs of valves being associated with one of said predetermined positions, said rotary v-alve being arranged to connect in each of said predetermined positions said irst control conduit to one and said second control conduit to the other of said control valves of the pair associated with said position, said machine comprising further a pressure lluid supply conduit and a drain conduit, each of said control valves being arbitrarily pre-adjustable to three positions, in one of which it is connected to said supply conduit, in the second of which it is connected to said drain conduit and in the third of which it is closed.

2. A forging machine as set forth in claim l, which comprises a throttle associated with each of said control valves and means selectively operable to connect said throttle in series with said control valve.

3. A forging machine as set forth in claim 2, in which said throttle and control valve are combined in a unit.

4. A `forging machine as set forth in clai-m 2, in -Which each of said control valves consists of a plug valve having a valve plug and an independently rotatable throttle member is coaxially mounted in said valve plug.

5. A forging machine as set forth in claim l, which comprises a valve block accommodating said rotary valve and said control valves, said control valves being arranged in two concentric circles and said rotary valve being disposed at the center of said circles.

6. A forging machine as set forth in claim 5, in which the centers of the control valves of each of said pairs lie in a common radial plane.

7. A 4forging machine as set forth in claim 1, in which each of said pistons has a piston rod connected to one 8 end of the piston and lis slidably movable in a cylinder, to which said control conduit is connected on the side opposite to said piston rod, said machine further comprising irneans for permanently applying hydraulic pressure to said pistons at said one end thereof.

8. A forging machine as set forth in claim l, in which said setting pistons are adapted to impart at the end of each of their movements to said stepping rollers an angular movement which s only a fraction of the movement required to reach the next of said predetermined positions, and which comprises a hydraulic piston drive operable to continue the angular movement of said stepping rollers until said next predetermined position has been reached, a magnetic valve arranged to control said hydraulic piston drive, a lirnit switch arranged to control said magnetic valve, and a camwheel arranged to rotate in unison with said stepping rollers and to operate said limit switch.

9. A forging machine as set forth in claim 8, in which said piston drive comprises a displaceable part formed as a rack, and which comprises a pinion in rnesh with said rack, a ratchet coupling for coupling said pinion to one of said stepping rollers, and an additional limit switch operable to reset said magnetic valve, said pinion being arranged to operate said additional limit switch when said stepping rollers have reached said next predetermined position.

References Cited in the tile of this patent UNITED STATES PATENTS 2,776,584 Burg Ian. 8, 1957 2,793,548 Kralowetz May 28, 1957 2,837,943 Saxer June l0, 1958

Claims (1)

1. A FORGING MACHINE WHICH COMPRISIES HAMMERS FORMED AS CONNECTING RODS, ECCENTRIC SHAFTS OPERABLE TO DRIVE SAID HAMMERS, ANGULARLY ADJUSTABLE HOUSINGS ECCENTRICALLY MOUNTING SAID SHAFTS, WORKPIECE FEED MEANS, A FIRST HYDRAULIC SETTING PISTON OPERABLE TO AXIALLY MOVE SAID WORKPIECE FEED MEANS, A SEOCND HYDRAULIC SETTING PISTON OPERABLE TO EFFECT AN ANGUALAR MOVEMENT OF SAID HOUSING, FIRST AND SECOND CONTROL CONDUITS ADPATED TO APPLY HYDRAULIC PRESSURE TO SAID FIRST AND SECOND PISTONS, RESPECTIVELY, TWO STEPPING ROLLERS WHICH ARE COUPLED FOR JOINT ROTATION TO A PLURALITY OF PREDETERMINED POSITIONS AND ASSOCIATED EACH WITH ONE OF SAID PISTONS AND ARRANGED TO PERFORM AN ANGULAR MOVEMENT TO THE NEXT OF SAID PREDETERMINED POSITIONS IN RESPONSE TO THE COMPLETION OF A MOVEMENT OF ONE OF SAID PISTONS, AND A VALVE SYSTEM ARRANGED TO CONTROL SAID SETTING PISTONS IN DEPENDENCE ON THE POSITION OF SAID STEPPING ROLLERS, SAID VALVE SYSTEM COMPRISING A COMMON ROTARY VALVE ARRANGED TO BE MOVED BY SAID STEPPING ROLLERS TO A PLURALITY OF POSITIONS CORRESPONDING TO SAID POSITIONS OF SAID STEPPING ROLLERS, A PLURALITY OF PAIRS OF CONTROL VALVES, EACH OF SAID PAIRS OF VALVES BEING ASSOCIATED WITH ONE OF SAID PREDETERMINED POSITIONS, SAID ROTARY VALVE BEING ARRANGED TO CONNECT IN

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