JP6280750B2 - Forging equipment - Google Patents

Description

  The present invention relates to a forging device that includes a plurality of punches, supports any one of these punches with hydraulic pressure, and releases the hydraulic pressure immediately before bottom dead center.

In the extrusion process, a material is placed on a die, a punch is extruded onto the die, and the material is plastically deformed. Since a large load acts on a die composed of a die and a punch, the life of the die is shortened.
One technique for extending the life of a mold is to reduce the maximum load applied to the mold by releasing the pressure of the pressure member before the end of the extrusion process (for example, Patent Document 1 (FIG. 1 See 1).).

The extrusion processing apparatus shown in FIG. 1 of Patent Document 1 includes an upper die set (21) (the numbers in parentheses indicate the symbols described in Patent Document 1. The same applies hereinafter), and a cylindrical punch (25). And a plurality of punches comprising pressure members (39). The cylindrical punch (25) is fixed to the upper die set (21). The pressurizing member (39) is movable up and down with respect to the upper die set (21) and supported by a hydraulic cylinder (43). A hydraulic pressure supply pipe (47) and a hydraulic pressure discharge pipe (49) are connected to the hydraulic cylinder (43). By switching the solenoid valve (51), the hydraulic pressure of the hydraulic cylinder (43) is released before the end of the extrusion process.
As a result, the maximum load applied to the mold is reduced, and the life of the mold is extended.

The extrusion process includes cold forging performed at room temperature and hot forging performed at high temperature.
In cold forging, since the temperature change does not become a problem, the processing time may be long.
On the other hand, in hot forging, it is necessary to finish plastic working while the temperature of a raw material is in a predetermined temperature range, and it is required to shorten the working time.

  The electromagnetic valve (51) is a valve that moves the plunger with an electromagnetic coil (solenoid). When the valve opening signal is received, the electromagnetic coil is energized to generate an electromagnetic force, and the plunger is moved by the generated electromagnetic force. The time required for energization, excitation, and movement is accumulated, and a time delay (time lag) of 0.1 second level occurs in a general-purpose solenoid valve. A special solenoid valve that is speeded up can shorten the valve opening time, but it is very expensive, and the effect of shortening the time is small for the cost increase.

Therefore, the technique of Patent Document 1 including a solenoid valve is suitable for cold forging with a relatively slow pressing speed.
However, in hot forging with a high press speed, it is necessary to operate the valve instantaneously at a level of, for example, 0.01 seconds, and the operation is not in time with an electromagnetic valve, and there is a problem that pressure cannot be reduced at an appropriate timing.

Japanese Patent No. 2534899

  It is an object of the present invention to provide a forging device that can reliably release hydraulic pressure even with an ultra-high speed press.

The invention according to claim 1 is a forging device including a die set having a plurality of punches and a hydraulic circuit for receiving any one of the plurality of punches by hydraulic pressure, and releasing the hydraulic pressure immediately before the bottom dead center of the press. And
This forging device comprises a bypass valve that opens and closes the flow path of the hydraulic circuit,
The die set includes a die holder that supports a die, and a punch holder that moves relative to the die holder and supports the plurality of punches,
A strike member is provided so as not to move relative to one of the die holder and the punch holder, and the bypass valve is provided so as not to move relative to the other.
The valve body of the bypass valve is pushed to the valve opening side by the strike member immediately before the bottom dead center, and the flow path of the hydraulic circuit is mechanically opened.

  The invention according to claim 2 is the forging device according to claim 1, wherein the bypass valve is provided in the punch holder.

  The invention according to claim 3 is the forging device according to claim 1 or 2, wherein the strike member is provided with a height adjustment mechanism for adjusting the height.

According to a fourth aspect of the present invention, in the forging device according to any one of the first to third aspects, a punch for forming a part to be processed in a subsequent process among a plurality of punches is received by hydraulic pressure. It is characterized by that.

  In the invention according to claim 1, the material is shunted by removing the hydraulic power of any punch immediately before the bottom dead center of the press. Therefore, the load applied to the mold at the end of molding can be reduced, and the mold life can be improved. Here, since the valve body is moved and mechanically switched just before the bottom dead center, there is no time delay like a solenoid valve, and even if the press speed is very fast such as hot forging, it follows the press speed. By operating the bypass valve at the appropriate timing, the hydraulic pressure can be released.

In the invention according to claim 2, the bypass valve is provided in the punch holder. If the bypass valve is provided in the die holder, the bypass valve is separated from the punch, the hydraulic circuit connecting the two becomes longer, the responsiveness is lowered, and a flexible pipe needs to be provided in the hydraulic circuit.
In this respect, according to the present invention, since the bypass valve is provided in the punch holder, the bypass valve can be brought close to the punch, and the responsiveness can be enhanced and the flexible tube can be eliminated.

  In the invention according to claim 3, since the strike member has a height adjustment mechanism for adjusting the height, the height of the strike member is set to a height required from the die set side after the die set is changed. Can be combined.

In the invention which concerns on Claim 4, the punch which shape | molds the site | part to which a process is added by a post process among several punches was received by hydraulic pressure. In other words, since the entire load is reduced by using a part whose accuracy is not so high, the precision of other parts can be increased.

It is a front view of the forging device concerning the present invention. It is sectional drawing of a bypass valve. It is sectional drawing of a strike member. It is a figure explaining the action | operation of a bypass valve. It is a figure explaining a forge process. It is an example of a change of a strike member.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

As shown in FIG. 1, the forging device 10 is a device having a die set 12 as a main element.
The die set 12 includes a die holder 14, a punch holder 16 disposed above the die holder 14, a guide post 18 extending upward from a corner of the die holder 14, and a downward from the punch holder 16 so as to surround the guide post 18. The guide bush 19 extends.

  Since the guide bush 19 is guided by the guide post 18, the punch holder 16 moves up and down accurately with respect to the die holder 14. In this example, the die holder 14 is a stationary member and the punch holder 16 is a moving member. However, the die holder 14 may be a moving member and the punch holder 16 may be a stationary member. Both holders 16 may be moving members.

  A die 22 is placed on the die holder 14 via a lower holder block 21, and the die 22 is fixed by a die presser 23.

  A first punch 26 is applied to the punch holder 16 via an upper holder block 25, and the first punch 26 is fixed by a punch press 27. A second punch 28 is disposed so as to penetrate the first punch 26 vertically, and a base portion (upper end portion in the drawing) of the second punch 28 is fixed to a horizontally long punch plate 29. The punch plate 29 is housed in a recess 31 provided in the upper holder block 25.

The punch holder 16 is provided with a donut-shaped cylinder hole 32, and a donut-shaped piston 33 is inserted into the cylinder hole 32, and piston rods 34, 34 extend downward from the piston 33, and the tip ends of these piston rods 34, 34. (The lower end in the drawing) is fixed to the punch plate 29.
After the piston 33 is accommodated, the upper opening of the cylinder hole 32 is closed with the lid 35, whereby a closed oil chamber 36 can be formed between the lid 35 and the piston 33.

  A strike member 40 is provided on the die holder 14 so as to extend upward, and a bypass valve 50 is provided on the punch holder 16 so as to be coaxial with the strike member 40. The valve body 51 of the bypass valve 50 protrudes downward.

A reserve tank 62 containing hydraulic oil 61 is disposed outside the die holder 14.
The reserve tank 62 is a sealed container, and an air pipe 64 extending from the high-pressure air source 63 is connected to the upper part.
The air pipe 64 is provided with a pressure adjustment valve 65 that makes the secondary air pressure constant. The pressure regulating valve 65 may be provided at the tip or base of the air pipe 64 in addition to the middle of the air pipe 64.

The reserve tank 62 and the oil chamber 36 are connected by a hydraulic circuit 70.
The hydraulic circuit 70 includes a first oil passage 71 that directly connects the reserve tank 62 and the oil chamber 36, and allows a flow from the reserve tank 62 to the oil chamber 36 that is provided in the first oil passage 71 to allow the oil tank 36 to reach the reserve tank. A first check valve 72 for blocking the flow to 62, a bypass 73 provided in the first oil passage 71 so as to bypass the first check valve 72, and an oil chamber 36 provided in the bypass 73. Between the relief valve 74 that opens when the pressure on the side exceeds the set pressure (higher than the normal pressure and, for example, the maximum pressure allowed in the facility), and between the oil chamber 36 and the first check valve 72. A second oil passage 76 that branches from the oil passage 71 and extends to the first port 75 of the bypass valve 50; a third oil passage 78 that connects the second port 77 of the bypass valve 50 and the reserve tank 62; Reservoir from the second port 77 provided in the oil passage 78 It permits a flow of the click 62 flows from the reserve tank 62 to the second port 77 and a second check valve 79 for blocking.

Detailed structures of the bypass valve 50 and the strike member 40 described above will be described with reference to FIGS.
As shown in FIG. 2, the bypass valve 50 includes a bottomed cylindrical valve box 52, a valve body 51 attached to the valve box 52 so as to be movable in the axial direction, and the valve body 51 in the valve closing direction. A valve spring 53 is provided, and a valve lid 54 that closes the valve box 52 after the valve spring 53 is housed in the valve box 52 is provided.

Furthermore, a conical surface valve seat 55 is integrally formed in the valve box 52, and a first port 75 and a second port 77 are provided to communicate between the inside and the outside of the valve box 52 so as to sandwich the valve seat 55. .
The valve body 51 includes a large-diameter portion 51a accommodated in the valve box 52 via the first O-ring 56, a seal surface 51b formed at one end of the large-diameter portion 51a and abutting on the valve seat 55, The small-diameter portion 51c is smaller in diameter than the large-diameter portion 51a and extends from one end of the large-diameter portion 51a to the outside of the valve box 52, and an abutting member 51d attached to the tip of the small-diameter portion 51c in a replaceable manner. A space between the small diameter portion 51 c and the valve box 52 is sealed with a second O-ring 57.

  In FIG. 2, the valve body 51 is urged by the valve spring 53, and the seal surface 51 b is in contact with the valve seat 55, so that the bypass valve 50 is in the valve closed state.

  As shown in FIG. 3, the strike member 40 includes a base member 42 with a flange 41 and a pillar member 43 extending upward from the base member 42 as basic elements. Therefore, the strike member 40 may have a form in which the column member 43 is directly coupled to the base member 42.

Preferably, the basic element includes a height adjusting mechanism 90.
The height adjusting mechanism 90 extends from the base member 42 and has a rod 92 having an external thread 91 on the outer peripheral surface, a lock nut 93 that is rotatably screwed into the base of the rod 92, and a column member 43. And an internal thread 94.

  The lock nut 93 is put on standby at the unlock position. Next, the column member 43 is turned right or left. When it is hard, a spanner may be hung on the spanner hooks 95, 95 provided on the column member 43 and rotated with this spanner. By rotating, the column member 43 can be raised or lowered to a desired height.

When the pillar member 43 reaches a desired height, the lock nut 93 at the standby position is raised while rotating, and the pillar member 43 is forcibly pushed up. Thus, the female screw 94 is more strongly engaged with the male screw 91, and a loosening prevention action is obtained.
Note that when the lock nut 93 is rotated, the column member 43 is slightly but may rotate together . When the lock nut 93 is turned in a state where the spanner is hung on the spanner hooks 95, 95, the common rotation can be prevented.

Next, the hot forging method implemented using the forging apparatus 10 having the above configuration will be described.
In FIG. 1, since the hydraulic pressure of the reserve tank 62 is transmitted to the oil chamber 36 via the first oil passage 71 and the first check valve 72, the hydraulic pressure of the reserve tank 62 is equal to the hydraulic pressure of the oil chamber 36. In this state, a material (FIG. 5A, reference numeral 97) heated to the forging temperature is set on the die 22. Next, the punch holder 16 is lowered at a high speed. The first punch 26 is supported by the punch holder 16, and the second punch 28 is supported by hydraulic pressure.

  At the start of the descent, as shown in FIG. 4 (a), there is a gap between the column member 43 of the strike member 40 and the valve body 51 of the bypass valve 50. Therefore, as shown in FIG. The valve is closed.

  As shown in FIG. 5A, the material 97 is crushed by the first and second punches 26 and 28 that descend at a high speed. Further, when the first and second punches 26 and 28 are lowered, plastic deformation proceeds as shown in FIG.

  When the first and second punches 26 and 28 are further lowered from FIG. 5 (b), a form immediately before the bottom dead center of the press is obtained. At this time, as shown in FIG. 4B, the valve body 51 hits the pillar member 43, and thereafter, the valve body 51 remains at the height. On the other hand, since the valve box 52 continues to descend, a gap is generated between the valve seat 55 and the seal surface 51b, and the first port 75 and the second port 77 communicate with each other as shown by arrows.

Due to this communication, in FIG. 1, the hydraulic pressure in the oil chamber 36 is released to the reserve tank 62 via the second oil passage 76, the bypass valve 50, the third oil passage 78, and the valve-opened second check valve 79. It is.
Then, as shown in FIG. 5C, the first punch 26 is lowered, but the second punch 28 is raised. In the material 97, the meat in the peripheral portion flows to the central portion.
As a result, the load applied to the die 22 and the first and second punches 26 and 28 is reduced.

  In addition, it cannot be said that the bypass valve 50 shown in FIG. If the bypass valve 50 cannot be opened due to a failure, the relief valve 74 is opened and the hydraulic pressure is released to the reserve tank 62 via the first oil passage 71 and the detour path 73. Therefore, there is no concern that excessive hydraulic pressure acts on the piston 33 or the like.

  By the way, in FIG. 2, when an upward striking force is applied to the valve body 51, there is a concern that the valve body 51 will jump up due to the reaction. However, since the valve body 51 is urged downward by the valve spring 53, there is no worry about that. Therefore, even at the 0.01 second level, the bypass valve 50 operates normally.

  As described with reference to FIG. 5, the central portion of the material 97 is plastically processed by the second punch 28. The second punch 28 is supported by hydraulic pressure as described in FIG. As shown in FIG. 5C, the peripheral portion formed by the first punch 26 has a highly accurate shape, but the central portion formed by the second punch 28 has a low accuracy. However, since the central portion is formed by punching a shaft hole in a later process and further finished by machining, accuracy is not required at the forging stage. That is, the punch (in this example, the second punch 28) for forming the portion (the central portion in this example) where the highest accuracy is required is received by hydraulic pressure.

Further, in FIG. 1, the die holder 14 may be provided with the bypass valve 50, and the punch holder 16 may be provided with the strike member 40. However, since the 2nd oil path 76 becomes long, response time becomes long. Further, it is necessary to provide a flexible pipe in the second oil passage 76.
In this regard, as shown in FIG. 1, when the bypass valve 50 is provided in the punch holder 16, the second oil passage 76 is shortened, and it is not necessary to provide a flexible pipe in the second oil passage 76.

Next, a modification example of the height adjustment mechanism 90 will be described.
As shown in FIG. 6, the height adjusting mechanism 90 </ b> B includes a driven side taper liner 101 that is integrally formed or attached to the lower end of the column member 43, and a drive side taper liner that is applied to the driven side taper liner 101 from below. 102, a flat liner 103 provided on the die holder 14 to support the drive side taper liner 102 so as to be horizontally movable, and an electric cylinder 104 provided on the die holder 14 for driving (moving) the drive side paper liner 102 The guide member 105 is provided on the die holder 14 and guides the column member 43 so as to be movable up and down.

The electric cylinder 104 includes a ball screw shaft, a ball nut screwed into the ball screw shaft, and a servo motor that rotates the ball nut, and can move the ball screw shaft back and forth with high accuracy.
When the driving side taper liner 102 is pushed by the ball screw shaft, the driven side taper liner 101 is pushed up by the taper action, and as a result, the column member 43 rises.
When the driving side taper liner 102 is pulled by the ball screw shaft, the driven side taper liner 101 is lowered and the column member 43 is lowered.

During this time, since the column member 43 is guided by the guide member 105, it moves up and down without swinging left and right.
Since the electric cylinder 104 is suitable for remote operation and automatic operation, the setting change of the strike member 40 can be easily performed when the setting change or the pattern change of the die set 12 is executed.

When a downward load is applied to the column member 43, the load is supported by the taper liners 101 and 102, and there is no fear that a downward force is applied to the electric cylinder 104. Although the ball screw mechanism is said to be a precision component, it is said that it is weak against impact force. However, since no downward force is applied, there is no concern that the life of the electric cylinder 104 will be shortened.
In addition, since it is not necessary to increase the rigidity of the electric cylinder 104, the electric cylinder 104 can be reduced in size and weight.

The bypass valve 50 and the height adjusting mechanism 90 are not limited to the embodiment, and the structure may be changed as appropriate.
The forging device 10 is suitable for hot forging, but may be applied to warm forging and cold forging.

Furthermore, the Strike member 40 provided on one die holder 14 and the punch holder 16, while the other providing a bypass valve 70, the strike member 40 or the bypass valve 70 can be provided on the floor in place of the die holder 14. Therefore, the strike member 40 may be provided so as not to be relatively movable with respect to one of the die holder 14 and the punch holder 16, the attachment portion is arbitrary, and the bypass valve 70 may be provided so as not to be relatively movable with respect to the other. The attachment site is arbitrary.

  DESCRIPTION OF SYMBOLS 10 ... Forging device, 12 ... Die set, 14 ... Die holder, 16 ... Punch holder, 22 ... Die, 26 ... First punch, 28 ... Second punch, 40 ... Strike member, 50 ... Bypass valve, 70 ... Hydraulic circuit, 90, 90B: Height adjustment mechanism.

Claims (4)

A forging device comprising a die set having a plurality of punches and a hydraulic circuit for receiving any one of the plurality of punches by hydraulic pressure, and releasing the hydraulic pressure immediately before the bottom dead center of the press,
This forging device comprises a bypass valve that opens and closes the flow path of the hydraulic circuit,
The die set includes a die holder that supports a die, and a punch holder that moves relative to the die holder and supports the plurality of punches,
A strike member is provided so as not to move relative to one of the die holder and the punch holder, and the bypass valve is provided so as not to move relative to the other.
A forging device characterized in that the valve body of the bypass valve is pushed to the valve opening side by the strike member immediately before the bottom dead center, and the flow path of the hydraulic circuit is mechanically opened. The forging device according to claim 1, wherein
The forging device, wherein the bypass valve is provided in the punch holder. In the forging device according to claim 1 or 2,
The forging device, wherein the strike member includes a height adjusting mechanism for adjusting a height. In the forging device according to any one of claims 1 to 3,
A forging device characterized in that, among the plurality of punches, a punch for forming a portion to be processed in a subsequent process is received by the hydraulic pressure.

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