JP3466445B2 - Double-acting die device for forging - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable first die, a fixed second die, a first punch slidably inserted in the first die, and a second die. And a second punch inserted into the first die, and the first die is clamped to the second die to perform the first stage forging, and then the first die is placed in the forming space between the two dies.
And a double-action die device for forging in which the second punch is pushed in to perform the second stage forging.

[0002]

2. Description of the Related Art Conventionally, as a mold apparatus of this type, as shown in FIG. 8, a first die holder c1 for a first die b1 which interlocks with a press ram a, and a first die b with respect to a second die b2 are provided.
The first punch chamber f1 and the first oil chamber e1 that receives the mold clamping reaction force of No. 1 via the first piston d1 connected to the first die b1.
Forming a second oil chamber e2 that presses the second piston d2 that is connected to the second die b2 side, and a third oil chamber e3 that faces the second oil chamber e2 with the second piston d2 interposed therebetween. Along with the second die holder c2 for the second die b2, a third oil chamber e4 that presses the third piston d3 connected to the second punch f2 to the first die b1 side, and a third piston d3 that sandwiches the third oil chamber e4. And a fifth oil chamber e5 facing the fourth oil chamber e4,
The first oil chamber e1, the second oil chamber e2, and the fourth oil chamber e4 are constantly communicated with each other via the closed hydraulic circuit g, and the third oil chamber e3 and the fifth oil chamber e5 are respectively connected. It is known to input the hydraulic pressure from the hydraulic pressure source h (see Japanese Patent Laid-Open No. 2-75433).

In this type, the second and third pistons d2 and d2 are moved until the die clamping of the first die b1 to the second die b2 is completed by advancing the first die holder c1 in the die clamping direction.
d3 is the hydraulic pressure distributed from the first oil chamber e1 to the second and fourth oil chambers e2, e4 via the closed hydraulic circuit g by the hydraulic pressures of the third and fifth oil chambers e3, e5. Against the retracted position, the hydraulic pressure distributed from the first oil chamber e1 to the second and fourth oil chambers e2, e4 is further increased by the further advance of the first die holder c1. The second and third pistons d2 and d3 move forward to move the first die b1 and the second die b2.
The first and second punches f1 and f2 are pushed into the molding space between and.

[0004]

In the conventional example described above, the hydraulic pressures that can oppose the hydraulic pressures corresponding to the forging load of the first stage generated in the first oil chamber e1 during mold clamping are set to the third and fifth oil pressures. Room e
3 and e5 must be supplied, and the hydraulic pressure source h becomes a high-pressure output and expensive.

In the hydraulic pipe for the closed hydraulic circuit g between the first oil chamber e1, the second oil chamber e2 and the fifth oil chamber e5, the first oil chamber e1 and the second oil chamber e2 are connected. Since the oil chamber e2 is formed in the movable first die holder c1, it is necessary to use a flexible tube. Further, since high pressure oil pressure acts on these hydraulic pipes, the durability of the hydraulic pipes is ensured. Difficult to do.

In view of the above points, it is an object of the present invention to provide a forging double-acting die device which is inexpensive and has excellent durability.

[0007]

[Means for Solving the Problems] In order to solve the above problems,
The present invention includes a movable-side first die, a fixed-side second die,
A first punch slidably inserted in the first die and a second punch slidably inserted in the second die, and the first die is clamped to the second die to perform a first step In the double-acting die machine for forging, in which the first and second punches are pushed into the forming space between the dies and the second stage forging is performed after the forging of the first die, A first oil chamber that receives the mold clamping reaction force of the first die with respect to the second die via a first piston connected to the first die is formed in the one die holder, and the first piston faces the first oil chamber. A second piston formed into a hollow shape having a pressure receiving wall and having a first punch connected to the first piston is inserted, and a second oil chamber between the second piston and the pressure receiving wall is inserted into the first piston. An air chamber facing the second oil chamber is defined by sandwiching the second piston, and the first oil chamber and the second oil chamber are communicated with the pressure receiving wall. The second piston is pressed against the pressure receiving wall by the air pressure of the air chamber to close the communication hole until the mold clamping is completed, and the communication hole is exhausted after the mold clamping is completed and the second piston is used. The communication hole should be unblocked, and the second die holder for the second die should be
A third oil chamber is formed that presses the third piston connected to the second punch toward the first die side, and the first piston and the second die holder are respectively connected to the first joint and the third oil chamber. A second joint communicating with the chamber is provided, and the first joint and the second joint are docked in a mold clamped state so that the second oil chamber and the third oil chamber are communicated with each other.

According to the present invention, while the communication hole is closed by the second piston, the portion of the second piston that receives the hydraulic pressure of the first oil chamber is limited to the portion of the communication hole, and the hydraulic pressure of the first oil chamber is limited. Even if the pressure rises to the hydraulic pressure corresponding to the forging load in the first stage due to the mold clamping, the second piston can be held in the retracted position where it abuts the pressure receiving wall by the relatively low air pressure of the air chamber. Here, since the factory air source can be used as the pressure source for the air chamber, it is inexpensive.

After the mold clamping is completed, that is, after the forging in the first stage is completed, the air is exhausted from the air chamber to release the blockage of the communication hole, and the oil flows from the first oil chamber into the second oil chamber through the communication hole. Furthermore, in this state, since the first and second joints are docked, oil also flows into the third oil chamber from the second oil chamber through both joints, and the second and third pistons The first and second punches are pushed into the forming space by the hydraulic pressures of the second and third oil chambers that act on the second stage forging. In the present invention, since the closed hydraulic circuit that connects the second and third oil chambers is formed by docking the first and second joints, a flexible tube is used as piping for the closed hydraulic circuit. There is no need to use it, and durability is secured.

When manufacturing a product with holes, generally, in the second stage of forging, the parts where holes are to be formed are forged from both sides by both the first and second punches, and the lacking part of the part that remains as a product. The remaining portion between the punches is filled and the remaining portion is removed and punched in a later step, but this increases the number of steps. On the other hand, when the moving stroke of the second piston with respect to the first piston toward the second die becomes a predetermined value or more for completing the second stage forging, the communication between the second oil chamber and the first joint is made. If a valve for shutting off is provided and oil is drained from the third oil chamber after the second stage forging, the second oil pressure in the third oil chamber
The pressing of the punch is released, and only the first punch is pressed by the hydraulic pressure of the second oil chamber. While pushing the second punch out of the molding space, the first punch is further pushed into the molding space, and the surplus portion is removed. It is punched out by the first punch. Therefore, it is not necessary to make a hole in the subsequent process, and it is possible to reduce the number of steps and reduce the processing cost of the product.

By the way, it is possible to perform die clamping of the first die by interlocking the first die holder with the press ram, but in this case, the forging load is limited to the pressing force of the press ram. On the other hand, the ram piston interlocking with the press ram is inserted into the first die holder,
If the first oil chamber is defined between the piston and the piston, the forging load can be made larger than the pressing force of the press ram by making the first piston larger in diameter than the ram piston.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a forging double-acting die apparatus for cold forging the connecting rod W of the engine shown in FIG. 7 (A). The mold apparatus includes an upper first die 1 that is a movable side, a second die 2 that is a fixed side, and a pair of left and right first punches 3L and 3R slidably inserted in the first die 1. When,
The second die 2 is provided with a pair of left and right second punches 4L and 4R slidably inserted therein. Left punch 3L, 4L
Faces the punched portion of the large end Wa of the connecting rod W, and the right punches 3R and 4R face the punched portion of the small end Wb of the connecting rod W.

The first die 1 is attached to a first piston 6 which is vertically movably inserted in an upper first die holder 5. In addition, the ram piston 8 which is located above the first piston 6 and interlocks with the press ram 7 is mounted on the first die holder 5.
Is vertically movably inserted to define a first oil chamber 9 between the first piston 6 and the ram piston 8. Then, the first piston 6 is formed to have a larger diameter than the ram piston 8 so that the first piston 6 can be pushed down with a pressure force larger than the pressure force of the press ram 7.

The first piston 6 is formed in a hollow shape having a pressure receiving wall 6a at the upper end facing the first oil chamber 9 and a cover plate 6b at the lower end, and the first die 1 is provided on the lower surface of the cover plate 6b. It is installed. In addition, the first punch 3L, 3R on the first piston 6
A second oil chamber 11 between the pressure receiving wall 6a and the second piston 10, and a second piston 10 sandwiching the second piston 10 between the A lower air chamber 12 that faces the oil chamber 11 is defined.
Further, the pressure receiving wall 6a is formed with a communication hole 6c which connects the first oil chamber 9 and the second oil chamber 11 to each other, and the second piston 10 is fixed to the pressure receiving wall 6a.
The communication hole 6c is closed by the second piston 10 when pressed against a.

The second die 2 has a lower second die holder 13
It is attached to the upper pedestal 13a. Second die holder 1
3, a third piston 14 that connects the second punches 4L and 4R is vertically movably inserted.
Is pressed by the hydraulic pressure of the third oil chamber 15 formed in the second die holder 13 to the first die 1 side, that is, upward. A stopper plate 13b that regulates the lower end position of the first piston 6 is fixed on the pedestal 13a.

Further, the first piston 6 and the second die holder 1
The first joint 16 communicating with the second oil chamber 11
And a second joint 17 communicating with the third oil chamber 15 are provided, and when the first piston 6 descends by a predetermined stroke or more, both the first and second joints 16 and 17 are docked, and the second oil chamber 11 And the third oil chamber 15 are communicated with each other. The first joint 16 is a sleeve 16a extending downward and fixed to a cover plate 6b at the lower end of the first piston 6.
And a valve body 16c that is urged downward by a spring 16b that closes the open end of the sleeve 16a, and the second joint 17 is a pedestal 13 at the upper end of the second die holder 13.
Sleeve 17 attached to a by biasing upward by spring 17b
a and the pedestal 13a for closing the open end of the sleeve 17a
And the valve body 17c fixed to the. Then, when the first piston 6 descends by a predetermined stroke or more, the sleeve 16a of the first joint 16 comes into contact with the sleeve 17a of the second joint 17 and pushes down the sleeve 17a, and the valve body 17c of the second joint 17 moves. The valve body 16c is pushed up by contacting the valve body 16c of the first joint 16, and the joints 16 and 17 are connected to the sleeve 16
The open ends of a and 17a are docked in a state where the closed ends are released.

The communication passages between the second and third oil chambers 11 and 15 and the joints 16 and 17 may be formed so as to bypass the second and third pistons 10 and 14, respectively. In the present embodiment, communication pipes 10a and 14a that slidably fit into the respective pistons 10 and 14 with the cover plate 6b and the pedestal 13a, respectively.
And the oil chambers 11 and 15 are formed in the pistons 10 and 14, and the communication holes 10b and 14b and the communication pipes 10a and 14a.
It is connected to each joint 16 and 17 via.

Further, the communication pipe 10a attached to the second piston 10 can be externally fitted to the valve guide 16d for the valve element 16c attached to the cover plate 6b. With this external fitting, the second oil chamber 11 and the first joint 16 can be fitted. The communication with and is cut off. That is, the communication pipe 10a and the valve guide 16d form the second
A valve 18 that blocks the communication between the oil chamber 11 and the first joint 16 is configured.

The first die holder 5 includes the second die holder 1
A cylinder portion 20 that receives a fixed piston 19a is provided on a tie rod 19 that is erected on the upper portion of the cylinder 3. When the hydraulic pressure is input to the upper chamber 20a of the cylinder portion 20, the first die holder 5 is pushed up, and the lower chamber of the cylinder portion 20 is pushed. When hydraulic pressure is input to 20b, the first die holder 5 moves the tie rod 19
It is configured to be pushed down to the lower end position regulated by the stopper 19b on the outer periphery of the.

Further, in the first die holder 5, a fourth oil chamber 21 facing the downward step surface formed in the middle of the first piston 6 is formed, and the first piston 6 is hydraulically moved to the fourth oil chamber 21. It is designed to be pushed up to the rising end position by inputting.

The second die 2 is composed of an outer die portion 2a for receiving the first die 1 and an inner die portion 2b opposed to the first die 1. The inner die portion 2b is knocked out to fix the pin 22a. It can be pushed up through.

FIG. 2 shows a fluid circuit of the mold apparatus, which enables the oil from the hydraulic pump 23 to be supplied to the first oil chamber 9 through the first electromagnetic valve 24 ₁ and the check valve 25. At the same time, the upper limit value of the hydraulic pressure of the first oil chamber 9 can be set by the relief valve 26. Third oil chamber 1
Oil can be supplied to and discharged from No. 5 via the second electromagnetic valve 24 ₂ . Furthermore, while as the air from the factory air source 27 can be supplied to the air chamber 12 via the third solenoid valve 24 ₃ by regulating the regulator 28, between the third solenoid valve 24 ₃ and the air chamber 12 A supply / exhaust shuttle valve 29 is provided so that air is exhausted from the air chamber 12 through the exhaust port 29a of the shuttle valve 29 when the third electromagnetic valve 24 ₃ is closed. Oil can be supplied to and discharged from the fourth oil chamber 21 via a fourth electromagnetic valve 24 ₄ . The upper chamber 20a and the lower chamber 20b of the cylinder portion 20 can be selectively refueled via the fifth electromagnetic valve 24 ₅ , and the upper and lower chambers 20a and 20b and the fifth electromagnetic valve 2
4 ₅ and pilot check valves 30 ₁ and 30 respectively
₂ , the pilot check valve 30 ₂ is opened when oil is supplied to the upper chamber 20a, and oil is discharged from the lower chamber 20b, and the pilot check valve 30 ₁ is supplied when oil is supplied to the lower chamber 20b.
Is opened and oil is drained from the upper chamber 20a.

Since high pressure acts on the oil passage between the check valve 25 and the relief valve 26 and the first oil chamber 9 and the oil passage between the pilot check valve 30 ₂ and the lower chamber 20b, at least these pressures are applied. The valve is the first die holder 5
To prevent the high pressure from acting on the flexible tube that is connected to the first die holder 5.

When the connecting rod W is forged, the preform W'shown in FIG. 7 (B), which is molded so that the volume distribution is substantially equal to that of the product, is set in the second die 2 and then the lower chamber of the cylinder portion 20 is set. Oil is supplied to 20b and the first die holder 5 is pushed down to the lower end position. When the first die holder 5 reaches the descending end position and this is detected by a position sensor (not shown), the press ram 7 starts to descend, and the fourth oil chamber 21 is drained to preform the first die 1. The first piston 6 descends by its own weight to the position where it abuts against W ′, and the state shown in FIG. 3 is obtained.

Next, the press ram 7 comes into contact with the ram piston 8 to push down the ram piston 8, and the hydraulic pressure in the first oil chamber 9 pushes down the first piston 10 with a pressure force larger than that of the press ram 7. The first stage forging of the reform W'is started. Then, as shown in FIG. 4, when the first piston 10 reaches the descending end position regulated by the stopper plate 13b and the first die 1 is clamped to the second die 2, the first stage forging is completed. To do.
In this state, the first and second joints 16 and 17 are docked, and the second oil chamber 11 and the third oil chamber 15 are in communication, but the second piston 10 is in communication by the air pressure of the air chamber 12. It is held in the retracted position to close the hole 6c,
And the hydraulic pressure is not acting on the third oil chambers 11 and 15.

When the press ram 7 descends to the position where the mold clamping is completed and this is detected by a position sensor (not shown), the air chamber 1
Air supply to the air conditioner 2 is stopped, and the air chamber 12 is rapidly exhausted via the shuttle valve 29. According to this, the blockage of the communication hole 6c by the second piston 10 is released, and the oil in the first oil chamber 9 is removed by the subsequent lowering of the press ram 7.
1 and the third oil chamber 15 and the second piston 10 moves to the second
While being pushed down by the oil pressure in the oil chamber 11, the third piston 14 is pushed up by the oil pressure in the third oil chamber 15, and as shown in FIG. 5, the first punches 3L, 3R and the second punches 4L, 4R are moved to the first position. The second stage forging is performed by being pushed into the molding space between the second dies 1 and 2 from above and below. In this second-stage forging, the drilled portion of the large end Wa and the drilled portion of the small end Wb of the connecting rod W are forged, and the portions other than the drilled portions of the large end Wa and the small end Wb are formed. Meat flows into the remaining flesh portion and fills the flesh portion. When the first piston 6 descends to a position where the second stage forging is completed, the communication pipe 10
a reaches the valve guide 16d, that is, the valve 18 is closed and the communication between the second oil chamber 11 and the third oil chamber 15 is cut off.

The press ram 7 descends to a position where the second stage forging is completed, and when this is detected by a position sensor (not shown), oil is discharged from the third oil chamber 15. According to this, the pushing up of the third piston 14 is released, and the oil further flows into the second oil chamber 11 due to the descending of the press ram 7.
0 is pushed further down. Then, as shown in FIG. 6, when the second punches 4L and 4R are immersed in the second die 2,
The punches 3L and 3R are pushed deeper into the forming space, and the surplus thicknesses Wc and Wd left between the first punches 3L and 3R and the second punches 4L and 4R are punched out.

After the forging is completed, first the press ram 7 is raised, then the upper chamber 20a of the cylinder portion 20 is lubricated to raise the first die holder 5, and then the air chamber 12 is supplemented with the second air.
The piston 10 is raised, then the fourth oil chamber 21 is filled with oil, the first piston 6 is raised, then the first oil chamber 9 is filled with oil, and the ram piston 9 is raised. 5, the first piston 6 and the second piston 10 are returned to their original positions. Then, the knockout 22 is actuated to push up the inner die portion 2b of the second die 2 to take out the forged connecting rod W, and then feed the third oil chamber 15 to push up the third piston 14 to push up the second punch 4L. , 4R pushes the excess thicknesses Wc and Wd from the second die 2 and blows them off with air, finally drains the third oil chamber 15 and lowers the third piston 14 by a spring (not shown) to perform one forging cycle. To complete.

Although the double-action die device for forging of connecting rod has been described above, the present invention can be similarly applied to the double-action die device for forging of other products.

[0030]

As is apparent from the above description, according to the present invention, as a pressure source for holding the first and second punches at the retracted position until the first stage forging is completed. Since an air source can be used, an expensive hydraulic source that generates high hydraulic pressure is not required, and the cost is reduced.
Since the oil chamber and the third oil chamber can communicate with each other without using a flexible tube, durability is also improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of the device of the present invention.

FIG. 2 is a fluid circuit diagram of the apparatus of FIG.

FIG. 3 is a sectional view showing a state before the start of forging.

FIG. 4 is a sectional view showing a state at the time of completion of forging in the first stage.

FIG. 5 is a sectional view showing a state at the time of completion of forging in the second stage.

FIG. 6 is a sectional view showing a state at the final point of forging.

7A is a perspective view showing a product, and FIG. 7B is a perspective view showing a preform.

FIG. 8 is a sectional view showing a conventional mold device.

[Explanation of symbols]

1 1st die 2 2nd die 3L, 3
R 1st punch 4L, 4R 2nd punch 5 1st die holder
6 1st piston 7 Plus ram 8 Ram piston 9
First oil chamber 10 Second piston 11 Second oil chamber 1
2 Air chamber 13 Second die holder 14 Third piston 1
5 3rd oil chamber 16 1st joint 17 2nd joint 1
8 valves

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Sugita 1-10-1 Shin-Sayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. (72) Inventor Yoshiro Akiyama 8-1 Hommachi, Wako-shi, Saitama Company Saitama Factory Wako Factory (72) Inventor Seiichi Akimoto 8-1 Honmachi, Wako City, Saitama Honda Motor Co., Ltd. Saitama Factory Wako Factory (56) Reference JP-A-5-253696 (JP, A) Hei 2-75433 (JP, A) JP 4-288997 (JP, A) JP 60-30545 (JP, A) Actual development 59-162135 (JP, U) (58) Fields investigated (Int .Cl. ⁷ , DB name) B21J 1/00-13/14 B21J 17/00-19/04 B21K 1/00-31/00

Claims (3)

(57) [Claims] 1. A first die on a movable side, a second die on a fixed side, a first punch slidably inserted in the first die, and a second die.
A second punch slidably inserted in the die, and after performing the first stage forging by clamping the first die to the second die, the first and the second die are formed in the forming space between the two dies. In a forging double-acting die apparatus in which both second punches are pushed in to perform the second stage forging, a first die holder for the first die is provided with a first die for the second die.
Forming a first oil chamber for receiving a die clamping reaction force through a first piston connected to the first die, forming the first piston in a hollow shape having a pressure receiving wall facing the first oil chamber, A second piston in which the first punch is connected to the first piston is inserted, and a second oil chamber between the second piston and the pressure receiving wall and a second oil chamber sandwiching the second piston are inserted into the first piston. And a communication hole that connects the first oil chamber and the second oil chamber to each other is formed in the pressure receiving wall, and the second piston is driven by the air pressure in the air chamber until mold clamping is completed. Is pressed against the pressure receiving wall to close the communication hole, and after completion of the mold clamping, the air chamber is exhausted to release the communication hole from the second piston, and the second die holder for the second die is While forming a third oil chamber that presses the third piston that connects the two punches to the first die side, A first joint that communicates with the second oil chamber and a second joint that communicates with the third oil chamber are provided in the first piston and the second die holder, respectively, and the first joint and the second joint are docked in a mold clamped state. The second oil chamber and the third oil chamber are communicated with each other. 2. The communication between the second oil chamber and the first joint when the moving stroke of the second piston with respect to the first piston toward the second die exceeds a predetermined value for completing the second stage forging. A double-acting die device for forging according to claim 1, wherein a valve for shutting off the oil is provided and the oil is drained from the third oil chamber after the forging in the second stage. 3. A ram piston interlocking with a press ram is inserted into the first die holder, and a first oil chamber is defined between the ram piston and the first piston.
Or the double-acting die device for forging according to 2.