JP6809668B2 - Mechanical hydraulic back pressure and diversion device in forging machines - Google Patents

Description

The present invention is a mechanical hydraulic back pressure and diversion device in a forging machine, specifically, a mechanical hydraulic back pressure and flow dividing device of a horizontal multi-stage forging machine that mainly forms a blank supplied to a plurality of forging stations into a product having a predetermined shape by forging. It relates to a flow dividing device.

In general, in a horizontal multi-stage forging machine, a plurality of dies are arranged side by side on a die block fixed at a predetermined position on the machine base frame, and each die is placed in front of a ram that moves forward and backward with respect to the die block. A plurality of punches are mounted facing each other, and these corresponding dies and punches constitute a multi-stage forging station. Then, a blank having a predetermined length is supplied to the forging station side, and the supplied blank is sequentially forged at a plurality of juxtaposed forging stations in a stepwise manner to form a product having a predetermined shape. There is.

By the way, when it is attempted to form a spur gear G having a large number of spur teeth a ... a and a shaft hole b having a very complicated shape as shown in FIG. 10, for example, by using the conventional horizontal multi-stage forging machine described above. As shown in the spur gear G'shown in FIG. 11, both end portions of the spur tooth a are not short enough and are curved round toward the center side toward both end sides, and the corner portion of the spur tooth a is not reached, resulting in a lack of meat. The rounded and inaccurate shape was far from the desired sharp spur gear shape, and it was difficult to forge a highly accurate spur gear. The reason is that it is very difficult to accurately form the part of the flat tooth a having a complicated shape by extruding a columnar blank that has been embedded and greatly extruded in the radial direction in one forging process. Even if an attempt is made to form the portions of the flat teeth a ... a stepwise over a plurality of times at a plurality of forging stations, a hardening phenomenon occurs in the blank as the number of forgings increases, so that the amount of forming by the second and subsequent forgings is extremely small. In addition, a larger molding load is also required, which makes it difficult to mold sharp flat teeth a ... a with high accuracy. From the above, at present, a spur gear G having a large number of sharp flat teeth a ... A as shown in FIG. 10 and a product having a complicated shape similar to the spur gear G are molded with high accuracy by the above-mentioned conventional horizontal multi-stage forging machine. It is difficult to do this, and it is rarely done, and it is currently formed by cutting with a milling machine or hobbing machine.

Therefore, in order to solve the above-mentioned problems, the present invention can perform both back pressure forging and diversion forging mechanically hydraulically by incorporating a die block cylinder inside the die block and generating hydraulic pressure by the movement of the ram. In addition to making it possible to form complex shaped parts such as spur gears with a forging machine, the forging load is reduced and the mold life is improved, and back pressure is also achieved during high-speed use by controlling the machining speed. An object of the present invention is to provide a mechanical hydraulic back pressure and diversion device in a forging machine capable of accurately controlling the operation of forging and diversion forging.

In order to solve the above problem, the invention according to claim 1 of the present application is between a die provided on a die block fixed to the machine base and a punch attached to the front surface of the ram so as to face the die. It is a mechanical hydraulic back pressure and diversion device in a forging machine that forges a blank into a product of a predetermined shape, and is built into a die block in a unitized state together with a hydraulic pump for initial pressure supply and a blank. It is equipped with a die block cylinder having a piston with a back pressure tool that applies back pressure against the molding load, a pressure adjustment hydraulic cylinder that sets the back pressure to a desired pressure, and an opening cylinder that releases the back pressure. The initial pressure supply hydraulic pump is connected to the die block cylinder via the first hydraulic pipe, and in the middle of the first hydraulic pipe, the pressure adjusting hydraulic cylinder and the opening cylinder are connected to the second hydraulic pipe and the third hydraulic pressure. The rams are located in front of the front dead point in the middle of the third hydraulic pipe, while the hydraulic circuits for back pressure and diversion are formed by these first to third hydraulic pipes, which are connected to each other via the pipes. A mechanical valve for releasing back pressure that opens at the timing of opening to release the hydraulic oil into the opening cylinder to reduce the pressure in the hydraulic circuit and closes at the timing after the ram passes the front dead point, and a cylinder for releasing from the first hydraulic pipe. with a check valve for preventing backflow of the hydraulic oil is provided in parallel to, the ram, hydraulic oil within the cylinder to reduce the open cylinder at a timing that leads to the rear dead center from the middle retraction of the ram Is provided with a pressing member that returns the flood control to the first hydraulic pipe, and the piston with back pressure tool enters the die by supplying the initial pressure of hydraulic oil to the cylinder chamber of the die block cylinder by the hydraulic pump for initial pressure supply. At the same time, from the start of molding to just before the front dead point when the ram is moving forward, the blank is given a back pressure that opposes the molding load by increasing the working pressure by compressing the hydraulic oil and adjusting the pressure by the pressure adjusting hydraulic cylinder. It is also characterized in that the ram is configured to retreat from the inside of the die from the front to the front dead point by lowering the operating pressure by releasing the hydraulic oil to the opening cylinder.

In the invention according to claim 2 of the present application, the back pressure release mechanical valve according to the invention according to claim 1 always comes into contact with a drive shaft having a drive cam and rotating in conjunction with the drive system of the machine. It is characterized by having a valve operating rod that moves forward and backward in synchronization with the forging operation by the rotation of the drive cam, and is configured to be opened and closed by mechanical valve control by the cam drive.

In the invention according to claim 3 of the present application, the hydraulic oil in the pressure adjusting hydraulic cylinder is first opened in the middle of the second hydraulic pipe according to the invention according to claim 1 at the timing when the ram starts to retreat from the front dead point. A solenoid valve that returns to the flood control pipe and closes when the ram is located before the rear dead point and a check valve that prevents the backflow of hydraulic oil from the pressure adjusting hydraulic cylinder to the first hydraulic pipe are provided in parallel. It is characterized by.

According to the invention according to claim 1 of the present application, the die block cylinder is built in the die block as described above, and the movement of the ram generates hydraulic pressure to perform back pressure forging and diversion forging in a mechanical hydraulic manner. Because of the configuration, that is, from the start of forging to just before the front dead center during the forward movement of the ram, the back pressure of the high operating pressure set by the pressure adjusting hydraulic cylinder is applied to the back pressure tool piston of the die block cylinder. Back pressure forging is performed, and from the front dead center to the front dead center of the remaining ram, the back pressure release mechanical valve is opened to release the back pressure, and the back pressure tool piston of the die block cylinder retreats from the die. Since it is configured so that the diversion forging can be performed, it is possible to form a spur gear having sharp spur teeth with high accuracy, which requires a complicated shape part such as a spur gear without any thinning. In addition, the forging load can be reduced and the mold life can be improved. Moreover, since it is configured to generate hydraulic pressure by the movement of the ram and perform back pressure forging and diversion forging in a mechanical hydraulic system, the operation control between back pressure forging and diversion forging even during high-speed use by controlling the machining speed. Can be done accurately. In addition, even if something goes wrong with the motion control mechanism, it does not require advanced and specialized knowledge, which can improve maintainability by workers in the field, and save space and cost. Can be done.

According to the invention according to claim 2 of the present application, the back pressure release mechanical valve is configured to be opened and closed by a mechanical valve control by a cam drive. Therefore, a servomotor is particularly used as a drive source of the machine. , Even when controlling the speed of the ram, such as maintaining the forward speed during forging of the ram at a predetermined speed and increasing the speed when retreating, the drive cam provided on the drive shaft linked to the drive system of the machine. The back pressure release mechanical valve can be opened and closed according to the rotation speed of. As a result, back pressure forging and diversion forging are always performed at an appropriate timing, and productivity can be improved.

According to the invention according to claim 3 of the present application, the ram is opened in the middle of the second hydraulic pipe at the timing when the ram starts to retreat from the front dead point, and the hydraulic oil in the pressure adjusting hydraulic cylinder is returned to the first hydraulic pipe and the ram. Since an electromagnetic valve that closes at the timing before the rear dead point and a check valve that prevents the backflow of hydraulic oil from the pressure regulating hydraulic cylinder to the first hydraulic pipe are provided in parallel, each stroke of the ram The hydraulic oil in the pressure adjusting hydraulic cylinder is once returned to the first hydraulic pipe, the back pressure is newly set for each stroke of the ram, and the back pressure forging can be performed in a state where the same back pressure is always applied.

It is a schematic plan view of the multi-stage horizontal forging machine provided with the mechanical hydraulic back pressure and diversion device which concerns on this invention. It is a process diagram by the forging machine. It is a hydraulic circuit diagram of the mechanical hydraulic back pressure and diversion device provided in the forging station of the 4th process. It is explanatory drawing of the forging station of the 4th process. It is operation explanatory drawing of the forging station. It is a molding process diagram of the flat tooth at the forging station. It is a diversion operation circuit diagram just before the dead center before the ram at the forging station. It is a flood control circuit diagram at the start of ram retreat at the forging station. It is a flood control circuit diagram just before the dead center after the ram at the forging station. It is explanatory drawing of the required spur gear. It is explanatory drawing of the conventional spur gear.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a horizontal multi-stage forging machine provided with a mechanical hydraulic back pressure and diversion device according to the present invention, and the forging machine 1 is a die block 3 fixed at a predetermined position of a machine base frame 2. A plurality of dies 4a ... 4g are arranged side by side, and a ram 5 that moves forward and backward with respect to the die block 3 is arranged, and a plurality of punches 6a ... 6g are arranged in front of the ram 5 so as to face each die 4a ... 4g. It is installed side by side. A plurality of stages (7 stages in the figure) of forging stations S1 to S7 are configured by the corresponding dies 4a ... 4 g and punches 6a ... 6 g.

A quill 7 is provided on one side of the machine base frame 2, and a cutting mechanism 8 for cutting the wire A across the quill 7 is provided immediately before the quill 7, and the cutting mechanism 8 cuts the wire A into a predetermined size. Blank B is formed by cutting into. In the embodiment, the wire rod A is cut by the cutting mechanism 8 to form a blank B having a predetermined size, and the blank B is forged by the forging stations S1 to S7. However, the cutting mechanism 8 is not provided and the blank B is predetermined in advance. The blank B formed in the dimensions may be used directly.

Then, the blank B is sequentially supplied to the forging stations S1 to 7 by a material transfer chuck (not shown), and predetermined molding is performed at each forging station S1 to 7 to obtain the blank B as shown in FIG. Spur gears having a large number of sharp, highly accurate spur teeth are formed. Specifically, in the forging stations S1 to S3, the cutting blank B shown in (a) of FIG. 2 is subjected to a stationary process, and the blank as shown in (b), (c), and (d) of FIG. B1 to B3 are formed, and then the blank B3 is turned 180 degrees and then back pressure forging and diversion are performed by the mechanical hydraulic back pressure and diversion device 10 of the present invention described later at the forging station S4 in the fourth step. Both forging and forging are performed to form a blank B4 having a large number of sharp flat teeth a ... a with high accuracy as shown in FIG. 2 (e). After that, in the forging stations S5 to S7, a shaft hole b having a predetermined diameter is punched in the center of the blank B4 as in the blank B5, and further, through an idle process like the blanks B6 and G, as shown in FIG. A high-precision spur gear (final product) G as shown is formed. In the embodiment shown in the figure, the blank B3 is turned 180 degrees and transferred to the forging station S4 in the fourth step, but the blank B3 is transferred in a parallel state without being turned 180 degrees. Of course, it may be formed by molding.
Further, although not shown, a servomotor is used as a drive source of the machine, and the cycle time of the ram 5 is increased, for example, while maintaining the forward speed at the time of forging the ram 5 at a predetermined speed and increasing the speed at the time of backward movement. It has a controllable configuration to improve productivity.

Next, the mechanical hydraulic back pressure and diversion device 10 of the forging station S4 in the fourth step constituting the characteristic portion of the present invention will be described.

As shown in FIG. 3, the mechanical hydraulic back pressure and diversion device 10 includes an initial pressure supply hydraulic pump 11 and a die 12 (this die 12 basically corresponds to the die 4d described above. It is interchangeably built in the die block 3 in a unitized state together with the die 12), and the ram 5 moves forward to compress the hydraulic oil, so that it enters the die 12 and enters the blank B4. A die block cylinder 15 having a piston 14 with a back pressure tool 13 that retreats from the inside of the die 12 to release the back pressure on the blank B4 by applying a back pressure to counter the molding load and lowering the operating pressure. It includes a pressure adjusting hydraulic cylinder 16 and a pressure adjusting air cylinder 17 for setting a pressure to a desired pressure, and an opening hydraulic cylinder 18 having one end that releases back pressure to the atmosphere.

As shown in FIG. 4, the die block cylinder 15 is a unitized die 12 and a hydraulic cylinder, and is built in the die block 3 at the fourth process position. A die 12 having a forming hole 12a for forming flat teeth is provided in the front portion of the die block cylinder 15, a cylinder chamber 15a is formed in the rear portion, and a piston 14 is moved in the front-rear direction in the cylinder chamber 15a. The interior is reciprocating. A back pressure tool 13 that also serves as a knockout pin is arranged at the tip of the piston 14. The back pressure tool 13 is supported by a shaft hole 12b formed on the rear side of the die 12 so as to be reciprocating in the axial direction, and when the piston 14 moves forward, the die 12 is formed as shown in FIG. The tip portion enters the hole 12a to apply back pressure to the blank B4 at the time of molding to enable back pressure forging, and when the piston 14 is restored, the die 12 is outward from the inside of the molding hole 12a. It is configured to release the back pressure on the blank B4 at the operation timing immediately before the front dead center of the ram 5 to enable diversion forging. A kickout pin mechanism is formed at the center of the piston 14 to kick the blank B4 out of the die 12 with the back pressure tool 13 in accordance with the operation of the punch 6d retracting from the die 12 after the molding is completed. The member 19 is incorporated. Since this knockout pin mechanism has a well-known configuration, the description of its structure and operation will be omitted.

Then, as shown in FIG. 3, the initial pressure supply hydraulic pump 11 is communicated and connected to the cylinder chamber 15a of the die block cylinder 15 by the first hydraulic pipe 20, and the pressure adjusting hydraulic cylinder is connected in the middle of the first hydraulic pipe 20. 16 is communicated and connected via a second hydraulic pipe 21 and an opening cylinder 18 is communicated with each other via a third hydraulic pipe 22, and these first to third hydraulic pipes 20 to 22 are hydraulic circuits for back pressure and diversion forging. Is formed.

In the middle of the second hydraulic pipe 21, the ram 5 opens at the timing when the ram 5 starts to retreat from the front dead point, the hydraulic oil in the pressure adjusting hydraulic cylinder 16 is returned to the first hydraulic pipe 20, and the ram 5 is before the rear dead point. An electromagnetic valve 23 that closes at a position timing and a check valve 24 that prevents backflow of hydraulic oil from the pressure adjusting hydraulic cylinder 16 to the first hydraulic pipe 20 are provided in parallel. In the embodiment shown in the figure, the pressure adjusting hydraulic cylinder 16 is continuously provided with a pressure adjusting air cylinder 17 as a means for setting a desired back pressure.

In the middle of the third hydraulic pipe 22, the ram 5 opens at the timing when it is located before the front dead point, and the hydraulic oil flows (releases) into the opening hydraulic cylinder 18 to reduce the back pressure in the hydraulic circuit and the ram. A back pressure release mechanical valve 25 that 5 closes at the timing after the front dead point passing vortex and a check valve 26 that prevents the backflow of hydraulic oil from the first hydraulic pipe 20 to the release hydraulic cylinder 18 are provided in parallel. There is. It should be noted that reducing the back pressure is a concept including eliminating the back pressure.

The back pressure release mechanical valve 25 advances and retreats in synchronization with the forging operation by the drive shaft 28 having the drive cam 27 and rotating in conjunction with the drive system of the machine, and the drive cam 27 constantly in contact with the drive cam 27. The valve operating rod 25a is provided, and opening and closing is performed by a mechanical valve control driven by a cam.
Specifically, at the timing when the ram 5 is located before the front dead center, the valve operating rod 25a rides up from the small diameter portion to the large diameter portion of the drive cam 27, and the valve operating rod 25a is pushed down to release the back pressure. The mechanical valve 25 is opened, and the valve operating rod 25a falls from the large diameter portion to the small diameter portion of the drive cam 27 at the timing after the ram 5 passes the front dead center, thereby pushing up the valve operating rod 25a and closing the back pressure release mechanical valve 25. The valve is controlled so as to.

In the opening hydraulic cylinder 18, the piston 18a abuts on the pressing member 5a provided on the ram 5 at the timing when the ram 5 is retreating, and the piston 18a is pushed in the shortening direction to push the hydraulic oil in the opening hydraulic cylinder 18. Is configured to be returned to the first hydraulic pipe 20 via the check valve 26.

Further, an initial pressure of, for example, 2 MPa is supplied from the initial pressure supply hydraulic pump 11. Further, in the embodiment shown in the figure, the ram 5 is opened near the initial pressure supply hydraulic pump 11 of the first hydraulic pipe 20 at the timing from the middle of the retreat of the ram 5 to the rear dead center to regulate the initial pressure supply timing. A mechanical valve 29 for supplying initial pressure is provided. The initial pressure supply mechanical valve 29 is driven by constantly contacting the drive shaft 31 which has a drive cam 30 and rotates in conjunction with the drive system of the machine, as in the structure of the back pressure release mechanical valve 25 described above, and the drive cam 30. It is equipped with a valve operating rod 29a that moves forward and backward in synchronization with the forging operation by the rotation of the cam 30, and is opened and closed by mechanical valve control by the cam drive.

With the above configuration, the back pressure of a high operating pressure of, for example, 18 MPa set by the pressure adjusting hydraulic cylinder 16 is applied to the piston 14 with the back pressure tool 13 from the start of forging to the front of the front dead center during the forward operation of the ram 5. Then, back pressure forging is performed, and from the remaining front dead center to the front dead center, the back pressure release mechanical valve 25 is opened and the back pressure is released by the release hydraulic cylinder 18, whereby the back pressure tool 13 is attached. The diversion forging can be performed by allowing the piston 14 to retreat from the molding hole 12a of the die 12.

Next, the operation of the mechanical hydraulic back pressure and diversion device 10 when molding the plank B4 shown in FIG. 6 (d) at the forging station S4 in the fourth step will be described.

First, as shown in FIG. 3, the ram 5 moves forward from the back dead center, and from immediately after the start of forming the blank B3 to before the front dead center of the ram 5, the pressure adjusting hydraulic cylinder 16 is set, for example, 18 MPa. Back pressure forging is performed under a state in which a high back pressure is applied to the piston 14 with the back pressure tool 13.
Specifically, at the start of molding, the molding is performed as shown in (a) of FIG. 5 under a low working pressure, and is formed into the shape shown in (a) of FIG.
Then, when the back pressure is turned on immediately after the start of molding, the molding is performed as shown in FIG. 5 (b) under the above high operating pressure, and the lower portion of the flat teeth is slightly formed as shown in FIG. 6 (b). Will be done.
Next, when the back pressure is turned off before the front dead center of the ram 5, the drive cam 27 opens the back pressure release mechanical valve 25 to allow the hydraulic oil to flow into the release hydraulic cylinder 18, and the hydraulic circuit. The back pressure inside is eliminated and the piston 14 is allowed to retreat in the cylinder chamber 15a (see (c) in FIG. 5). Then, as shown in FIG. 6 (c), the middle to lower portion of the flat tooth is roughly formed.

After that, as shown in FIG. 7, the drive cam 27 keeps the back pressure release mechanical valve 25 open and the hydraulic oil is released even when the ram 5 reaches the front dead center from the front dead center. The piston 14 is retracted by flowing into the hydraulic cylinder 18 to eliminate the back pressure in the hydraulic circuit. Along with this, the back pressure tool 13 together with the piston 14 allows the die 12 to retreat from the forming hole 12a. As a result, as shown in FIG. 5D, diversion forging is performed from before the front dead center to the front dead center of the ram 5. In this diversion forging, the flow direction of the material is positively controlled and flowed to the outer portion in the radial direction and the central discard shaft portion, so that the pressure can be reduced and the wall loss at the corner can be eliminated. As a result, a blank B4 having sharp flat teeth a ... a with high accuracy and a discard shaft portion as shown in (d) of FIG. 6 is formed.

After that, as shown in FIG. 8, the solenoid valve 23 in the middle of the second hydraulic pipe 21 is opened at the timing when the ram 5 starts to retreat from the front dead center, and the hydraulic oil in the pressure adjusting hydraulic cylinder 16 is released. 1 When it is returned to the hydraulic pipe 20, the push-in by the drive cam 27 is eliminated and the back pressure release mechanical valve 25 is closed.

Further, as shown in FIG. 9, the piston rod 18a of the opening hydraulic cylinder 18 comes into contact with the pressing member 5a provided on the ram 5 at the timing during the retreat of the ram 5, and the piston rod 18a is pushed in the shortening direction to open. The hydraulic oil in the hydraulic cylinder 18 is returned to the first hydraulic pipe 20. Further, at the same timing as this, the solenoid valve 23 is closed, the initial pressure supply mechanical valve 29 is opened by the drive cam 30, and an initial pressure of, for example, 2 MPa is supplied from the initial pressure supply pump 11, and the next back pressure is supplied. Prepare for combined flow forging.

After that, a series of forging operations starting from the post-dead center of the ram 5 described above will be repeated.

In the above-described embodiment, the case where the mechanical hydraulic back pressure and diversion device 10 of the present invention is used in a horizontal multi-stage forging machine for forging spur gears has been described, but it is not limited to spur gears. Of course, it can be widely applied to other complex-shaped parts.

Further, in the mechanical hydraulic back pressure and diversion device 10 of the present invention described above, a mechanical valve switching means (not shown) for selectively switching the back pressure release mechanical valve 25 to the ON / OFF state may be separately provided, or a large size may be provided. The pressure adjusting hydraulic cylinder 16 may be specially installed. By providing the mechanical valve switching means and the large pressure adjusting hydraulic cylinder 16 in this way, for example, when the desired molded product has a relatively simple shape, the set pressure of the pressure adjusting hydraulic cylinder 16 can be set to the desired shape of the molded product. It is possible to perform back pressure forging by using only the back pressure action in a state where the back pressure release mechanical valve 25 is not actuated while the back pressure is set appropriately low according to the above. As a result, a wider range of molded products can be forged, and optimum forging can be performed according to the molded product. As the mechanical valve switching means, for example, the large diameter portion (cam ridge portion) of the drive cam 27 of the valve operating rod 25a is formed separately from the small diameter portion, and the cam ridge portion is replaced with a chip with respect to the small diameter portion. It may be fixed with bolts so that it can be attached and detached according to the forging state to be adopted.

1 Horizontal multi-stage forging machine 3 Die block 4a ... 4g Die 5 Lamb 5a Pressing member 6a ... 6g Punch 10 Mechanical hydraulic back pressure and diversion device 11 Initial pressure supply hydraulic pump 12 (4d) Die 15 Die block cylinder 16 For pressure adjustment Hydraulic cylinder 18 Release hydraulic cylinder 18a Piston 20 1st hydraulic pipe 21 2nd hydraulic pipe 25 Back pressure release mechanical valve 26 Check valve 27 Drive cam 28 Drive shaft S1 to S7 Forging station

Claims (3)

Mechanical hydraulic back pressure in a forging machine that forges a blank into a product of a predetermined shape between a die provided on a die block fixed to the machine base and a punch attached to the front surface of the ram so as to face the die. It is a dual flow device and has a hydraulic pump for initial pressure supply and a piston with a back pressure tool that is built into the die block in a unitized state together with the die and applies back pressure to the blank to counter the molding load. A die block cylinder, a pressure adjusting hydraulic cylinder for setting the back pressure to a desired pressure, and an opening cylinder for releasing the back pressure are provided, and an initial pressure supply hydraulic pump is connected to the die block cylinder via a first hydraulic pipe. In addition to being communicated and connected, the pressure adjusting hydraulic cylinder and the opening cylinder are communicated and connected via the second hydraulic pipe and the third hydraulic pipe, respectively, in the middle of the first hydraulic pipe, and these first to third hydraulic pipes are connected. While a hydraulic circuit for back pressure and diversion is formed by this, the ram opens at the timing when it is located before the front dead point in the middle of the third hydraulic pipe to release the hydraulic oil into the opening cylinder and inside the hydraulic circuit. reducing the pressure of and the ram and the timing mosquito valve before top dead center after passing, together with a check valve for preventing back flow of hydraulic fluid to the open cylinder of the first hydraulic pipe are provided in parallel, the ram A pressing member is provided to shorten the opening cylinder and return the hydraulic oil in the cylinder to the first flood control pipe at the timing from the middle of the retreat of the ram to the rear dead point, and further, the piston with a back pressure tool is provided. The initial pressure of the hydraulic oil to the cylinder chamber of the die block cylinder by the initial pressure supply hydraulic pump enters the die, and the hydraulic oil is compressed from the start of molding to just before the front dead point when the ram advances. By increasing the working pressure and adjusting the pressure by the pressure adjusting hydraulic cylinder, the blank is given a back pressure against the molding load, and the hydraulic oil to the opening cylinder is applied to the ram from the front dead point to the front dead point. A mechanical hydraulic back pressure and diversion device in a forging machine characterized in that it is configured to retreat from inside the die by lowering the operating pressure by opening the . The back pressure release mechanical valve has a drive cam that rotates in conjunction with the drive system of the machine, and a valve operating rod that constantly contacts the drive cam and moves forward and backward in synchronization with the forging operation due to the rotation of the drive cam. The mechanical hydraulic back pressure and diversion device in the forging machine according to claim 1, further comprising a cam-driven mechanical valve control for opening and closing. Electromagnetic waves that open in the middle of the second hydraulic pipe at the timing when the ram starts to retreat from the front dead point, return the hydraulic oil in the pressure adjusting hydraulic cylinder to the first hydraulic pipe, and close at the timing when the ram is located before the rear dead point. The mechanical hydraulic back pressure type in the forging machine according to claim 1, wherein a valve and a check valve for preventing the backflow of hydraulic oil from the pressure adjusting hydraulic cylinder to the first hydraulic pipe are provided in parallel. Divergence device.

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