JP2000334537A - Closed forging method and closed forging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the excessive load on a die and a punch even when the volume of a material is larger than the volume of a target completed forged stock by advancing a part of an inner wall of a closed space to a first position when the volume of the material is not less than the first volume, and retracting the other part of the inner wall of the closed space to set the volume of the closed space to be equal to the volume of the material. SOLUTION: After a forging stock 13 is set in a forming die hole 7 to a lower die 4, a holding force larger than the load applied on a die pin 5 is added to the die pin 5 when the forging stock 13 is filled in a forming die cavity, and the die pin 5 is held at the specified position. An upper die 8 is lowered to achieve the forging, the load on the die pin 5 becomes equal to the holding force of the die pin 5 during the forging. When the upper die 8 is further lowered and the load on the die pin 5 is larger than the holding force of the die pin 5, the excessive forging stock 13 is abutted on the die pin 5 to overcome the holding force of the die pin 5, and the die pin 5 is retracted to form a discharge margin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a closed forging method and a closed forging apparatus.

[0002]

2. Description of the Related Art Conventionally, in a closed forging method, when the volume of a material is smaller than the volume of a target forged product,
Since the material is not filled and the dimensional accuracy is not obtained, the volume of the material is made larger than the target volume of the forged product.

[0003] On the other hand, when the volume of the forging material is increased as described above, the inside of the molding cavity is closed before the forging process is completed, and a large load is applied to the mold and the punch. was there.

To address this problem, Japanese Patent Publication No. Sho 58-8
No. 4632 describes a closed die forging method using a superplastic metal. In this forging method, when the forming force reaches a certain value during the forging, a movable space provided in a part of the mold is moved to form a filling gap inside the mold, and excess metal is formed there. There is a description that the dimensional accuracy is improved by removing the surplus portion after flowing in.

[0005]

In the forging method described in the above-mentioned publication, since a void is generated in the closed space at the time of completion of forging, the material excessively flows to the disposal allowance 3a side and flows to the molded article main body side. An unfilled part was generated.

In addition, when excess metal flows into the gap, there is no restriction on the flow direction of the metal. Therefore, when the metal flows into the gap, friction occurs between the molding cavity and the gap. Cracking defects may occur.

[0007] An object of the present invention is to prevent the mold or punch from being subjected to an excessive load even when the volume of the material is larger than the target volume of the completed forged product, and to allow the material to be unfilled when the forging is completed. It is an object of the present invention to provide a closed forging method which can be reduced in size.

Another object of the present invention is to prevent a mold or a punch from being subjected to an excessive load even if the volume of a material is larger than a target volume of a forged product, and to prevent cracking of the material at the completion of forging. An object of the present invention is to provide a closed forging device that reduces as much as possible.

[0009]

According to a first aspect of the present invention, there is provided a closed forging method in which a material disposed in a closed space is pressurized by a part of an inner wall of the closed space to fill the closed space. In the above, when the volume of the material is equal to or less than the first volume, the closed space volume is made equal to the first volume by advancing a part of the inner wall to the first position, When the volume is larger than the first volume, a part of the inner wall is advanced to the first position, and another part of the inner wall of the closed space is retracted to reduce the closed space volume to the volume of the material. By providing a closed forging method that is equivalent to, for example, even if the volume of the material placed in the mold exceeds the volume of the target product initially, the volume of the closed space in the mold is increased toward the volume of the material. Since they can be matched, And it can be forged without causing insufficient filling also without such force is applied.

According to a second aspect of the present invention, in the closed forging method according to the first aspect, when the closed space volume is formed to be equal to the volume of the material, the volume of the molded product is equal to the first volume. By providing a closed forging method having a step of removing a surplus part so that the volume of the material arranged in the mold exceeds the volume of the target product in addition to the effect of claim 1. Even so, it becomes easy to obtain a desired product shape by removing the excess portion.

According to a third aspect of the present invention, there is provided a closed forging method in which a material disposed in the closed space is pressurized by a part of an inner wall of the closed space to fill the closed space. The filling of the material into the closed space is completed by causing the portion to advance to the first position, and the internal pressure of the closed space when a part of the inner wall is advanced to the first position, If greater than the first pressure,
When the internal pressure of the closed space when retreating another part of the inner wall of the closed space and advancing a part of the inner wall to the first position is equal to or lower than a first pressure, By providing a closed forging method that does not cause the rest of the inner wall of the closed space to recede, for example, even if the volume of the material placed in the mold exceeds the volume of the initially intended product, the volume of the closed space in the mold is reduced. Can be adjusted to the volume of the material, so that forging can be performed without applying unnecessary force to the mold or punch and without causing poor filling. In addition, since the volume of the closed space in the mold is made variable according to the internal pressure, the internal pressure does not increase more than the first pressure to be set, so that damage to the mold can be reduced.

According to a fourth aspect of the present invention, in the process of causing a part of the inner wall to advance to the first position, when the internal pressure of the closed space fluctuates in a transient state, the internal pressure of the closed space is increased to the first position. Even when the internal pressure of the closed space is larger than the first pressure, the other portion of the inner wall of the closed space is not retreated, and when the internal pressure fluctuation of the closed space is in a steady state, the internal pressure of the closed space is larger than the first pressure. By providing the closed forging method according to claim 3, wherein the other part of the inner wall of the closed space is retracted, for example, in a case where the pressure is intensively increased at an early stage of the forging process, When it is better not to retreat the other part, normal molding can be performed.

According to a fifth aspect of the present invention, there is provided an urging means for urging the inner wall of the closed space in a direction that prevents the other portion of the inner wall from retracting, and when the internal pressure fluctuation changes from a transient state to a steady state, By providing the closing forging method according to claim 4, wherein the urging force of the urging means is reduced,
For example, in the initial stage of the forging process, when the pressure is intensively increased and it is better not to retract the other part of the inner wall, the other part of the inner wall may be retracted by the urging force. When the other portion of the inner wall is to be retracted at a later stage of the forging process, the portion can be retracted by reducing the urging force of the urging means so that normal molding can be performed. can do.

According to a sixth aspect of the present invention, the determination of whether the internal pressure fluctuation is in a transient state or a steady state is performed based on detection of a position of a part of an inner wall of the closed space. By providing the method, the progress of the forging process can be accurately grasped, and the effect according to claim 4 or 5 can be further enhanced.

According to a seventh aspect of the present invention, the determination as to whether the internal pressure fluctuation is a transient state or a steady state is made based on an elapsed time after a part of the inner wall of the closed space is moved. By providing the closed forging method according to 5,
Even in a situation where it is difficult to measure the pressure or a situation where it is difficult to detect the position of a part of the inner wall, the movement of the other part of the inner wall can be accurately grasped, and the effect of claim 4 or 5 can be obtained. Can be even higher.

In another embodiment, the other portion of the inner wall is
2. A part of the inner wall has advanced to the second position while pressing the material before the part has advanced to the first position.
By providing the closed forging method according to any one of to 7, since the pressure is applied to another part of the inner wall and then the pressure is applied to a part of the inner wall, the filling of the material is performed regardless of the material shape or the like. It can be more reliable.

According to a ninth aspect of the present invention, there is provided a forging die having a closed space, wherein a material disposed inside the closed space is pressed by a part of an inner wall of the closed space. By providing a forging die that can be retracted,
For example, even if the volume of the material placed in the mold exceeds the volume of the target product initially, the volume of the closed space in the mold can be adjusted to the volume of the material, so unnecessary force on the mold and punch However, forging can be performed without such a problem and without causing poor filling.

According to a tenth aspect of the present invention, the portion which can be retracted is held by a predetermined urging force.
By providing the forging die described, it is possible to control the portion that can be retracted in accordance with the internal pressure, so, for example, even if the volume of the material arranged in the die exceeds the volume of the initially targeted product, Since the volume of the closed space can be adjusted to the volume of the material, forging can be performed without applying unnecessary force to the mold or punch and without causing poor filling. In addition, since the volume of the closed space in the mold is made variable according to the internal pressure, the internal pressure does not increase more than the first pressure to be set, so that damage to the mold can be reduced.

In the eleventh aspect, by providing the forging die according to the tenth aspect, the biasing force is variable.
For example, in the initial stage of the forging process, when the pressure is intensively increased and it is better not to retract the other part of the inner wall, the other part of the inner wall may be retracted by the urging force. When the other portion of the inner wall is to be retracted at a later stage of the forging process, the portion can be replaced by reducing the urging force of the urging means, so that normal molding can be performed. can do.

According to a twelfth aspect of the present invention, another part of the inner wall can be retracted in conjunction with a part of the inner wall.
Provision of the forging die according to any one of to 11 can realize an accurate forging according to the progress of the forging process,
The effects of claims 9 to 11 can be further enhanced.

In a fourteenth aspect, by providing a forging die according to any one of the eighth to twelfth aspects, a part of the inner wall is urged by hydraulic pressure.
The control of the movement of a part of the inner wall becomes easier.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a closed forging method and a closed forging apparatus according to the present invention will be described below with reference to FIGS.

This closed forging device has a main body frame (not shown), a lower mold 2 provided on the main body frame, and an upper mold 3 provided on the main body frame so as to face the lower mold. The lower die 2 includes a lower die 4, a die spin 5, and a first hydraulic cylinder 19 that holds the die spin 5 and can be driven up and down. The lower die 4 is fixedly arranged, the upper surface 11 of the lower die 4 is formed in a horizontal plane, and a pin insertion hole 6 having a vertical circular cross section is formed in the center of the lower die 4 so that excess material flows. A pin insertion hole 6 is formed to allow the pin to pass therethrough. The die pin 5 is mounted in the pin insertion hole 6 so as to be slidable up and down.

At a position corresponding to the pin insertion hole 6, a lower forming hole 7 is formed near the upper surface of the lower die 4 so as to communicate with the upper end of the pin insertion hole 6. The first hydraulic cylinder 19 is disposed vertically below the die pin 5, and
The upper end of the piston rod 19 a of the hydraulic cylinder 19 is in contact with the die pin 5. First hydraulic cylinder 19
To hold the die pin 5 at the position shown in FIGS. 1 and 2, lower the die pin 5 while applying a holding force to the die pin 5, and raise the die pin 5 to eject the molded product after molding. Is possible.

The upper die 3 has an upper die 8, an upper outer punch 9, and a main hydraulic cylinder 20 (corresponding to a vertical driving means and a second hydraulic cylinder) for driving the upper die 8 up and down. The upper die 8 is vertically slidably guided through a guided portion slidably engaged with a guide portion formed on the main body frame.
Can be driven up and down.

The lower surface 10 of the upper die 8 is formed in a horizontal plane in contact with the upper surface 11 of the lower die 4. At the center of the upper die 8, an upper outer punch 9 projects downward integrally with the upper die 8. Is formed. A molding hole 12 is formed near the lower center of the upper outer punch 9.

Next, the hydraulic control device 18 of the closed forging device 1 will be described. As shown in FIG. 6, this hydraulic control device 18 (corresponding to hydraulic control means) includes one or more main hydraulic cylinders 20 and first hydraulic cylinders 1.
9 and a hydraulic supply device 22 (having a hydraulic pump, a pump drive motor, an oil tank and the like) for supplying and discharging hydraulic pressure to and from the third hydraulic cylinder 21, and electromagnetic directional control valves 23 to 25 and electromagnetic proportional relief valves 26 and 27. Control unit 2 for controlling a hydraulic circuit including a plurality of detection switches 28, a hydraulic supply device 22, and solenoid valves (23 to 25, 26, 27)
9 are provided.

The piston rod 20a of the double-acting main hydraulic cylinder 20 is connected to the upper die 8, and a double-acting first hydraulic cylinder 20 is provided.
The piston rod 19 a of the hydraulic cylinder 19 is in contact with the die pin 5. The electromagnetic directional control valve 23 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the main hydraulic cylinder 20, and the electromagnetic directional control valve 24 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the first hydraulic cylinder 19. The switching valves 23 and 24 are controlled by a control unit 29.

The electromagnetic proportional relief valve 26 is connected to a supply oil passage to the first hydraulic cylinder 19, and is connected to the first hydraulic cylinder 19.
Is supplied with the hydraulic pressure set by the electromagnetic proportional relief valve 26. This electromagnetic proportional relief valve 26 is connected to a control unit 29
Is controlled by

The plurality of detection switches 28 are connected to the upper die 8.
And a detection switch for detecting the upper limit position and the lower limit position. The control unit 29 has a microcomputer and an input / output interface, and the ROM of the microcomputer stores the hydraulic supply device 22 and the solenoid valves (23 to 25, 2) based on a detection signal from the detection switches 28.
6, 27) are previously input and stored.

A method of forging the forging material 13 with the above configuration will be described with reference to FIGS.

First, as shown in FIG. 1, the upper die 8 is held at the upper limit position, and the forging material 13 is inserted into the forming hole 7 of the lower die 4.
Is set.

Next, a holding force larger than the load applied to the die spin 5 when the forging material 13 fills the molding cavity C1 is applied to the die spin 5, and the die spin 5 is held at a predetermined position shown in FIG. In this case, the set pressure of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, and the upper end of the die pin 5 is formed through the electromagnetic directional switching valve 24 and the first hydraulic cylinder 19 as shown in FIG. After the height position of the die pin 5 is set so as to be flush with the lower end of the, the electromagnetic directional control valve 24 is switched to the block position a.

Next, in a state where the setting of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the electromagnetic directional control valve 23 is switched, and the piston rod 20 of the main hydraulic cylinder 20 is switched.
By driving a downward, the upper die 8 is driven downward to forge the forged material 13.

FIG. 2 shows a state in which the load applied to the die spin 5 during forging has become equal to the holding force of the die spin 5. When the upper die 8 is further driven downward and the load applied to the die spin 5 becomes larger than the holding force of the die spin 5, the excess forging material 13a contacts the die spin 5 and holds the die spin 5, as shown in FIG. Die-spin 5 retreats, flows into pin insertion hole 6 and is discarded 13
a is formed. When the upper die 8 moves to a predetermined position, the processing is completed and the forged material 13 is processed to a predetermined size. Note that the disposal allowance 13a of the forging material 13 formed in the pin insertion hole formed by retreating the die spin 5 may be removed later.

During this molding, a holding force larger than the load applied to the die spin 5 when the forging material 13 fills the molding cavity C1 is applied to the die spin 5. The first holding means for holding the die pin 5 is a first means.
Since the hydraulic pressure of the hydraulic cylinder 19 can be set variously using the hydraulic cylinder 19, when the forging material 13 fills the molding cavity C1, the load applied to the die pin 5 can be easily grasped. Therefore, forging can be performed with a minimum necessary forming force.

After the completion of the forging, the upper die 3 is returned to the upper limit position, and the die spin 5 is raised to the upper limit position, so that the forging material 13 is taken out from the lower die 2.

FIG. 4 is a perspective view and a cross-sectional view of the product forged as described above, and FIG. 5 is a perspective view of the product completed by removing the allowance 13a by post-processing such as cutting after molding. It is a figure and a sectional view.

According to the above-mentioned forging method, when the forging material 13 fills the molding cavity C1, a holding force larger than the load applied to the die spin 5 is applied to the die spin 5. Therefore, the forging material 13 is formed in the molding cavity C1. The forged material flows into the pin insertion hole 6 without fail. Therefore, no underfill occurs.

Even if the forging material 13a becomes full during the forging, the excess forging material 13a abuts on the die spin 5 and overcomes the holding force of the die spin 5, so that the pin insertion hole is moved as shown in FIG. 6, the forging is not interrupted due to the closed high pressure state, and the load on the mold can be reduced.

Further, since the forging is not interrupted and the process is completed up to the final step, a forged product with high dimensional accuracy can be obtained by removing the surplus part (the discarding allowance 13a) after forging.

It is not necessary to strictly control the weight of the forging material 13 in advance, and the disposal allowance can be set so as to be convenient for the post-processing.

By giving the die spin 5 a holding force,
Since a pressure in a direction opposite to the flow direction of the excess forging material 13a is applied, cracking defects due to a frictional force acting between the molding hole 7 and the vicinity of the entrance of the pin insertion hole 6 are less likely to occur.

A first hydraulic cylinder 19 is used as a holding means for holding the die pin 5, and the first hydraulic cylinder 19
Is changed to change the holding force of the die spin 5, so that the holding force of the die spin 5 can be appropriately adjusted.

FIGS. 7 to 12 show a second embodiment.
A second embodiment will be described with reference to FIGS. 6, 7 to 12. FIG.

The closed forging device 30 has a main frame (not shown), a lower die 31 provided on the main frame, and an upper die 32 provided on the main frame to face the lower die 31. The lower die 31 includes a lower die 33 and a die spin 3
4 and the first capable of holding the die pin 34 and driving up and down.
And a hydraulic cylinder 19. The lower die 33 is fixedly arranged, the upper surface 42 of the lower die 33 is formed in a horizontal plane, and a pin insertion hole 35 having a vertical circular cross section is formed in a central portion of the lower die 33 so that excess material flows therein. A pin insertion hole 35 is formed to allow the pin to pass therethrough. The die pin 34 is mounted in the pin insertion hole 35 so as to be slidable up and down.

At a position corresponding to the pin insertion hole 35, a lower forming hole 36 is formed near the upper surface of the lower die 33 so as to communicate with the upper end of the pin insertion hole 35. The first hydraulic cylinder 19 is disposed vertically below the die pin 34, and the upper end of the piston rod 19 a of the first hydraulic cylinder 19 is in contact with the die pin 34. The first hydraulic cylinder 19 holds the die spin 34 at the position shown in FIGS. 7, 8 and 9, lowers the die spin 34 while applying a holding force to the die spin 34, and ejects the molded product after molding. 34 can be raised.

The upper die 32 includes an upper die 37 and a punch 38.
And the main hydraulic cylinder 2 that drives the upper die 37 up and down
0 (corresponding to the lifting drive means and the second hydraulic cylinder) and the third hydraulic cylinder 2 for driving the punch 38 up and down.
And 1. The upper die 37 is vertically movably guided via a guided portion slidably engaged with a guide portion formed on the main body frame, and can be driven up and down by the main hydraulic cylinder 20.

The lower surface 41 of the upper die 37 is in contact with the lower die 33.
A punch insertion hole 39 having a circular cross section is formed in the center of the upper die 37.

In a portion corresponding to the punch insertion hole 39, an upper molding hole 40 is formed near the lower surface of the upper die 37 so as to communicate with the lower end of the punch insertion hole 39. In a state where the upper die 37 is clamped, the upper molding 40 is in the lower molding hole 3.
6 (see FIG. 8).

The punch 38 is for transmitting the processing force to the material 43 and is formed in a circular cross section.
Are arranged so as to be vertically movable through a punch insertion hole 39 at the center of the upper die. The punch 38 is connected to a piston rod 21a of a third hydraulic cylinder 21 disposed above the punch 38, and is driven by the third hydraulic cylinder 21 to move up and down.

Next, the hydraulic control device 18 of the closed forging device 30 will be described. As shown in FIG. 6, this hydraulic control device 18 (corresponding to hydraulic control means) supplies and discharges hydraulic pressure to one or more main hydraulic cylinders 29, the first hydraulic cylinder 19, and the third hydraulic cylinder 21. A hydraulic circuit including a hydraulic supply device 22 (having a hydraulic pump, a pump drive motor, an oil tank, etc.), electromagnetic directional control valves 23 to 25 and electromagnetic proportional relief valves 26 and 27, a plurality of detection switches 28, Control unit 2 for controlling hydraulic supply device 22 and solenoid valves (23 to 25, 26, 27)
9 are provided.

The piston rod 20a of the double-acting main hydraulic cylinder 20 is connected to the upper die 37, the piston rod 19a of the double-acting first hydraulic cylinder 19 abuts on the die pin 34, and the double-acting third hydraulic cylinder 19 The piston rod 21 a of the hydraulic cylinder 21 is connected to a punch 38. The electromagnetic directional control valve 23 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the main hydraulic cylinder 20, and the electromagnetic directional control valve 24 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the first hydraulic cylinder 19. The valve 25 is provided in an oil passage for supplying and discharging hydraulic pressure to and from the third hydraulic cylinder 21, and these electromagnetic direction switching valves 23 to 25 are controlled by a control unit 29.

The electromagnetic proportional relief valve 26 is connected to a supply oil passage to the first hydraulic cylinder 19, and is connected to the first hydraulic cylinder 19.
Is supplied with the hydraulic pressure set by the electromagnetic proportional relief valve 26. This electromagnetic proportional relief valve 26 is connected to a control unit 29
Is controlled by Similarly, the electromagnetic proportional relief valve 27 is connected to a supply oil passage to the third hydraulic cylinder 21, and the hydraulic pressure set by the electromagnetic proportional relief valve 27 is supplied to the third hydraulic cylinder 21. The electromagnetic proportional relief valve 27 is controlled by the control unit 29.

The plurality of detection switches 28 are connected to the upper die 3.
7, a detection switch for detecting the upper limit position and the lower limit position of the punch 38, a detection switch for detecting the upper limit position and the lower limit position of the punch 38, and the like. The control unit 29 has a microcomputer and an input / output interface. The ROM of the microcomputer stores the hydraulic pressure supply device 22 and the solenoid valves (23 to 2) based on a detection signal from the detection switches 28.
5, 26, 27) are input and stored in advance.

A method of forging the forging material 43 with the above configuration will be described with reference to FIGS. 6, 7 to 12.

First, as shown in FIG.
The punch 38 is held at the upper limit position, and the forging material 43 is set in the forming hole 36 of the lower die 33.

Next, as shown in FIG. 8, the electromagnetic directional control valve 23 is switched to extend the piston rod 20a of the main hydraulic cylinder 20, and the upper die 37 is lowered.
The upper die 32 is clamped to the lower die 31, and the punch 38 is brought into a predetermined positional relationship with the upper die 37.

Next, a predetermined holding force is set on the die pin 34, and the die pin 34 is held at a predetermined position shown in FIG. In this case, the set pressure of the electromagnetic proportional relief valve 26 is set to a predetermined pressure,
Via the electromagnetic directional control valve 24 and the first hydraulic cylinder 19,
As shown in FIG. 8, the upper end of the die pin 34
After setting the height position of the die pin 34 so as to be flush with the lower end of the solenoid valve 6, the electromagnetic directional control valve 24 is moved to the block position a.
Switch to.

Next, in a state where the setting of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the electromagnetic direction switching valve 25 is switched, and the piston rod 21a of the third hydraulic cylinder 21 is switched.
When the punch 3 is driven downward, as shown in FIG.
8 is driven downward to process the forged material 43. Then, the forged material 43 is plastically deformed. FIG. 9 shows a state in which the load applied to the die spin 34 during forging becomes equal to the holding force of the die spin 34. Further, when the punch 38 is driven to move downward and the load applied to the die spin 34 becomes larger than the holding force of the die spin 34, as shown in FIG. 10, the excess forging material 43a comes into contact with the die spin 34 and the holding force of the die spin 34 is reduced. Wins, dice pin 34 retreats,
It flows into the pin insertion hole 35, and a disposal margin 43a is formed. When the punch 38 moves to a predetermined position, the processing is completed and the forged material 43 is processed to a predetermined size. It is to be noted that the forging material 43 formed in the pin insertion hole formed by retracting the die pin 34 has a disposal margin 43.
a may be removed later.

During this molding, the holding force of the die spin 34 is set to be larger than the load applied to the die spin 34 when the forging material 43 fills the molding cavity C. The first hydraulic cylinder 19 is used as holding means for holding the die pin 34, and the hydraulic cylinder 19
The forging material 4 can be set in various ways.
When 3 fills the molding cavity C2, the die spin 3
The load applied to 4 can be easily grasped. Therefore, forging can be performed with a minimum necessary forming force.

After the completion of the forging, the upper die 32 is returned to the upper limit position, and the die spin 34 is raised to the upper limit position, whereby the forged material 43 is taken out from the lower die 31.

FIG. 11 is a perspective view and a cross-sectional view of the product forged as described above, and FIG. 12 is a perspective view of the product completed by removing post-processing 43a by post-processing such as cutting after molding. FIG.

Next, according to the above forging method, the forged material 4
When the die cavity 3 fills the molding cavity C2, the die spin 3
4, a holding force greater than the load applied to the die spin 34 is applied to the forged material 43.
The surplus forging material 43a flows into the pin insertion hole 35 without fail. Therefore, no underfill occurs.

Even if the forged material 43a becomes full during forging, the excess forged material 43a contacts the die spin 34, overcomes the holding force of the die spin 34, and moves the die spin 34 while moving the pin through hole as shown in FIG. 35, the forging does not interrupt due to the sealed high pressure state, and the load on the mold can be reduced.

Further, since the forging is not interrupted and the process is completed up to the final step, a forged product having good dimensional accuracy can be obtained by removing the surplus part (discard allowance 43a) after forging.

It is not necessary to strictly control the weight of the forged material 43 in advance, and the disposal allowance can be set so as to be convenient for the post-processing.

By giving the holding force to the die pin 34, a pressure in a direction opposite to the flow direction of the excess forging material 43a is applied, so that the molding hole 36 and the pin insertion hole 3
Also, cracking defects caused by a frictional force acting between the vicinity of the entrance of No. 5 hardly occur.

The first hydraulic cylinder 19 is used as holding means for holding the die pin 34, and the first hydraulic cylinder 1
Since the holding force of the die spin 34 is changed by changing the pressure of No. 9, the holding force of the die spin 34 can be appropriately adjusted.

FIGS. 13 to 17 show a third embodiment. A third embodiment will be described with reference to FIGS.

This closed forging apparatus has a main frame (not shown), a lower die 45 provided on the main frame, and an upper die 46 provided on the main frame opposite to the lower die. The lower die 45 includes a lower die A47, a lower die B48, a ring die spin 49, and a first hydraulic cylinder 19 that holds the ring die spin 49 and can be driven up and down. The lower die A47 and the lower die B48 are fixedly arranged, the upper surface 54 of the lower die A47 is formed in a horizontal plane, and the lower die A47 and the lower die B48 form a ring-shaped pin insertion hole 50 having a vertical ring-shaped cross section. However, a ring-shaped pin insertion hole 50 for letting excess material flow is formed. The ring die pin 49 has a ring-shaped pin insertion hole 50.
Slidable up and down.

At a portion corresponding to the ring-shaped pin insertion hole 50, a lower forming hole 51 is formed by the lower die A 47 and the lower die B 48 so as to communicate with the upper end of the ring-shaped pin insertion hole 50. The first hydraulic cylinder 19 is disposed vertically below the ring die pin 49, and the upper end of the piston rod 19 a of the first hydraulic cylinder 19 is in contact with the ring die pin 49. 1st hydraulic cylinder 1
9 to hold the ring die spin 49 at the position shown in FIGS. 13 and 14, lower the ring die spin 49 while applying a holding force thereto, and eject the molded product after molding. Can be raised.

The upper die 46 has an upper die 52, an upper outer punch 55, and a main hydraulic cylinder 20 for driving the upper die 52 up and down (corresponding to a lifting drive means and corresponding to a second hydraulic cylinder). The upper die 52 is guided vertically vertically movably via a guided portion slidably engaged with a guide portion formed on the main body frame, and can be driven up and down by the main hydraulic cylinder 20.

The lower surface 53 of the upper die 52 is connected to the lower die A4.
The upper die 52 is formed in a horizontal plane in contact with the upper surface 54, and an upper outer punch 55 is formed at the center of the upper die 52 integrally with the upper die 52 so as to protrude downward. A molding hole 56 is formed near the lower center of the upper outer punch 55.

Next, the hydraulic control device 18 of the closed forging device 44 will be described. As shown in FIG. 6, this hydraulic control device 18 (corresponding to hydraulic control means) supplies and discharges hydraulic pressure to one or more main hydraulic cylinders 20, first hydraulic cylinder 19, and third hydraulic cylinder 21. A hydraulic circuit including a hydraulic supply device 22 (having a hydraulic pump, a pump drive motor, an oil tank, etc.), electromagnetic directional control valves 23 to 25 and electromagnetic proportional relief valves 26 and 27, a plurality of detection switches 28, Control unit 2 for controlling hydraulic supply device 22 and solenoid valves (23 to 25, 26, 27)
9 are provided.

The piston rod 20 a of the double-acting main hydraulic cylinder 20 is connected to the upper die 52, and the piston rod 19 a of the double-acting first hydraulic cylinder 19 is in contact with a ring die pin 49. The electromagnetic directional control valve 23 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the main hydraulic cylinder 20, and the electromagnetic directional control valve 24 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the first hydraulic cylinder 19. Switching valve 2
3 and 24 are controlled by the control unit 29.

The electromagnetic proportional relief valve 26 is connected to a supply oil passage to the first hydraulic cylinder 19, and is connected to the first hydraulic cylinder 19.
Is supplied with the hydraulic pressure set by the electromagnetic proportional relief valve 26. This electromagnetic proportional relief valve 26 is connected to a control unit 29
Is controlled by

The plurality of detection switches 28 are connected to the upper die 8.
And a detection switch for detecting the upper limit position and the lower limit position. The control unit 29 has a microcomputer and an input / output interface, and the ROM of the microcomputer stores the hydraulic supply device 22 and the solenoid valves (23 to 25, 2) based on a detection signal from the detection switches 28.
6, 27) are previously input and stored.

A method for forging the forging material 57 with the above configuration will be described with reference to FIG. 6, FIG. 13 to FIG.

First, as shown in FIG.
At the upper limit position, the lower die A47 and the lower die B
A forging material 57 is set in a molding hole 51 formed by 48.

Next, a holding force larger than the load applied to the ring die spin 49 when the forging material 57 fills the molding cavity C3 is applied to the ring die spin 49, as shown in FIG. It is held at a predetermined position 58. In this case, the set pressure of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, and the upper end of the ring die pin 49 is set to the predetermined position 58 shown in FIG. 1 via the electromagnetic direction switching valve 24 and the first hydraulic cylinder 19. After setting to the height position, the electromagnetic direction switching valve 24 is switched to the block position a.

Next, in a state where the setting of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the electromagnetic directional control valve 23 is switched, and the piston rod 20 of the main hydraulic cylinder 20 is switched.
By driving a downward, the upper die 52 is driven downward to forge the forged material 57.

FIG. 14 shows a state in which the load applied to the ring die spin 49 during forging is equal to the holding force of the ring die spin 49. Further, when the upper die 52 is driven to descend and the load applied to the ring die spin 52 becomes larger than the holding force of the ring die spin 49, as shown in FIG.
9 and overcomes the holding force of the ring die spin 49, retreats the ring die spin 49, flows into the ring-shaped pin insertion hole 50, and forms a disposal margin 57a. When the upper die 52 moves to a predetermined position, the processing is completed and the forged material 57 is processed to a predetermined size. It is to be noted that the forging blank 57a formed in the ring-shaped pin insertion hole formed by retreating the ring die pin 49 is disposed aside.
May be removed later.

During this molding, the ring die spin 4
9, a holding force greater than the load applied to the ring die spin 49 when the forging material 57 fills the molding cavity C3.

Since the first hydraulic cylinder 19 is used as holding means for holding the ring die pin 49 and the hydraulic pressure of the hydraulic cylinder 19 can be set variously,
When the forging material 57 fills the molding cavity C3, the load applied to the ring die spin 49 can be easily grasped. Therefore, forging can be performed with a minimum necessary forming force.

After the completion of the forging, the upper die 46 is returned to the upper limit position, and the ring die spin 49 is raised to the upper limit position, whereby the forging material 57 is taken out from the lower die 45.

FIG. 16 is a perspective view and a sectional view of the product forged as described above, and FIG. 17 is a perspective view of the product completed by removing post-processing allowance 57a by post-processing such as cutting after molding. It is a figure and a sectional view.

According to the forging method described above, when the forging material 57 fills the molding cavity C3, the ring die spin 4
Since a holding force greater than the load applied to the load 9 is applied to the ring die spin 49, the forged material 57 reliably fills the details of the molding cavity C 3, and the excess forged material flows into the ring-shaped pin insertion hole 50. Therefore, no underfill occurs.

Even if the forging material becomes full during forging, the surplus forging material 57a contacts the ring die pin 49,
As the holding force of the ring die pin 49 is exceeded and the ring die pin 49 is moved and flows into the ring-shaped pin insertion hole 50 as shown in FIG. 15, the forging caused by the sealed high pressure state does not occur, The load on the mold can also be reduced.

Further, since the forging is not interrupted and the process is completed up to the final step, a forged product with high dimensional accuracy can be obtained by removing the surplus part (discard allowance 57a) after forging.

It is not necessary to strictly control the weight of the forged material 57 in advance, and the disposal allowance can be set so as to be convenient for the post-processing, so that the workability is greatly improved.

By providing the ring die spin 49 with a holding force, a pressure in a direction opposite to the flow direction of the surplus forging material 57a is applied, so that the vicinity of the inlet of the molding hole 51 and the ring-shaped pin insertion hole 50 is provided. Cracks due to the frictional force acting between them are less likely to occur.

The first hydraulic cylinder 19 is used as holding means for holding the ring die pin 49, and the holding force of the ring die pin 49 is changed by changing the pressure of the first hydraulic cylinder 19. The holding force can be adjusted appropriately.

Next, a description will be given of a modification in which the above embodiment is partially modified.

1] In the closed forging apparatuses 1 and 30, a booster that generates a hydraulic pressure by an air cylinder driven by a pneumatic pressure is applied as a hydraulic pressure supply means for supplying a hydraulic pressure to the first hydraulic cylinder 19, and the air pressure is switched between high and low. Thus, the holding force of the die spin 5 and the die spin 34 may be switched between high and low. In addition, relief valve 2
Instead of 6, 27, a regulator capable of adjusting the set pressure may be applied.

2] The closed forging devices 1 and 30 may be incorporated in a crank press or a friction press, and the upper die 8 and the upper die 37 may be driven up and down by the crank press.

Further, the above-described embodiment is merely an example, and it is a matter of course that the present invention can be implemented in a form in which various changes are added without departing from the gist of the present invention.

FIGS. 18 to 24 show a fourth embodiment. A fourth embodiment will be described with reference to FIGS.

The closed forging apparatus 100 includes a main body frame (not shown) and a lower mold 101 provided on the main body frame.
An upper mold 102 is provided on the main body frame so as to face the lower mold 101. The lower die 101 includes a lower die 103,
It has a die spin 104 and a first hydraulic cylinder 19 that holds the die spin 104 and can be driven up and down. The lower die 103 is fixedly disposed, and the upper surface 1 of the lower die 103 is fixed.
Reference numeral 12 is formed on a horizontal surface, and a pin insertion hole 105 having a vertical circular cross section for allowing surplus material to flow is formed at the center of the lower die 103. The die pin 104 is mounted in the pin insertion hole 105 so as to be vertically slidable.

At a position corresponding to the pin insertion hole 105, a lower forming hole 106 is formed near the upper surface of the lower die 103 so as to communicate with the upper end of the pin insertion hole 105. The first hydraulic cylinder 19 is disposed vertically below the die pin 104, and the upper end of the piston rod 19 a of the first hydraulic cylinder 19 is in contact with the die pin 104. The first hydraulic cylinder 19 holds the die spin 104 at the position shown in FIGS. 18, 19, and 20, lowers the die spin 104 while applying a holding force to the die spin 104, and ejects the molded product after molding. 104 can be raised.

The upper die 102 includes an upper die 107, a punch 108, a main hydraulic cylinder 20 for driving the upper die 107 up and down (corresponding to a vertical drive unit, and corresponding to a second hydraulic cylinder), and raising and lowering the punch 108. A third hydraulic cylinder 21 to be driven. The upper die 107 is vertically vertically movably guided via a guided portion slidably engaged with a guide portion formed on the main body frame, and can be driven up and down by the main hydraulic cylinder 20.

The lower surface 111 of the upper die 107 is formed in a horizontal plane in contact with the upper surface 112 of the lower die 103.
09 is formed.

At a position corresponding to the punch insertion hole 109, an upper molding hole 110 is formed near the lower surface of the upper die 107.
Are formed at the lower end of the punch insertion hole 109 so as to communicate with each other. When the upper die 107 is clamped, the upper die 11
0 communicates with the lower molding hole 106 (see FIG. 19).

The punch 108 is for transmitting a processing force to the material 113, and is formed in a circular cross section. The punch 108 is disposed so as to be vertically movable through a punch insertion hole 109 at the center of the upper die. . The punch 108 is connected to a piston rod 21a of a third hydraulic cylinder 21 disposed above the punch 108, and is driven by the third hydraulic cylinder 21 to move up and down.

Next, the hydraulic control device 18 of the closed forging device 100 will be described. As shown in FIG. 6, this hydraulic control device 18 (corresponding to hydraulic control means)
A hydraulic supply device 22 (having a hydraulic pump, a pump drive motor, an oil tank, and the like) for supplying and discharging hydraulic pressure to one or a plurality of main hydraulic cylinders 29, the first hydraulic cylinder 19, and the third hydraulic cylinder 21, and an electromagnetic direction switching valve A hydraulic circuit including 23 to 25 and electromagnetic proportional relief valves 26 and 27, a plurality of detection switches 28, a control unit 29 for controlling the hydraulic supply device 22 and the electromagnetic valves (23 to 25, 26, 27); Is provided.

The piston rod 20a of the double-acting main hydraulic cylinder 20 is connected to the upper die 107, the piston rod 19a of the double-acting first hydraulic cylinder 19 abuts on the die pin 104, and the double-acting third hydraulic cylinder Hydraulic cylinder 21
The piston rod 21a is connected to the punch 108. The electromagnetic directional control valve 23 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the main hydraulic cylinder 20, and the electromagnetic directional control valve 24 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the first hydraulic cylinder 19.
The electromagnetic directional control valve 25 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the third hydraulic cylinder 21.
5 is controlled by the control unit 29.

The electromagnetic proportional relief valve 26 is connected to a supply oil passage to the first hydraulic cylinder 19, and is connected to the first hydraulic cylinder 19.
Is supplied with the hydraulic pressure set by the electromagnetic proportional relief valve 26. This electromagnetic proportional relief valve 26 is connected to a control unit 29
Is controlled by Similarly, the electromagnetic proportional relief valve 27 is connected to a supply oil passage to the third hydraulic cylinder 21, and the hydraulic pressure set by the electromagnetic proportional relief valve 27 is supplied to the third hydraulic cylinder 21. The electromagnetic proportional relief valve 27 is controlled by the control unit 29.

The plurality of detection switches 28 are connected to the upper die 1
A detection switch for detecting an upper limit position and a lower limit position of 07,
A detection switch for detecting the upper limit position and the lower limit position of the punch 108 is included. The control unit 29 has a microcomputer and an input / output interface. The ROM of the microcomputer stores the hydraulic pressure supply device 22 and the solenoid valves (23 to 23) based on a detection signal from the detection switches 28.
25, 26, 27) are input and stored in advance.

A method of forging the forging material 113 with the above configuration will be described with reference to FIGS. 6, 18 to 24.

First, as shown in FIG.
7. Holding the punch 108 at the upper limit position, the lower die 103
A forging material 113 is set in the molding hole 106 of FIG.

Next, as shown in FIG. 19, the electromagnetic directional control valve 23 is switched to extend the piston rod 20a of the main hydraulic cylinder 20, lower the upper die 107, and move the upper die 107 relative to the lower die 101. The mold 102 is clamped, and the punch 108 is set in a predetermined positional relationship with respect to the upper die 107.

Next, a predetermined holding force is set on the punch 108, and the punch 108 is held at a predetermined position shown in FIG. In this case, the set pressure of the electromagnetic proportional relief valve 27 is set to a predetermined pressure,
Via the electromagnetic directional switching valve 25 and the third hydraulic cylinder 21,
After setting the height position of the punch 108 so that the lower end of the punch 108 is at the position shown in FIG. 19, the electromagnetic direction switching valve 25 is switched to the block position a.

Next, in a state where the setting of the electromagnetic proportional relief valve 27 is set to a predetermined pressure, the electromagnetic directional control valve 24 is switched, and the piston rod 19a of the first hydraulic cylinder 19 is switched.
As shown in FIG. 20, the die spin 104 is driven up to a predetermined position to drive the forging material 113 upward.
To process. Then, forging material 113 is plastically deformed.

At this time, the holding force of the punch 108 is set to be larger than the load applied to the punch 108, or the upward movement of the punch 108 is restricted by a mold or the like, so that the punch 108 is moved upward. Can be prevented.

Next, a predetermined holding force is set on the die spin 104, and the die pin 104 is held at a predetermined position shown in FIG. In this case, the set pressure of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the die pin 104 is set to a predetermined position via the electromagnetic direction switching valve 24 and the first hydraulic cylinder 19, and then the electromagnetic direction switching valve 24 is set. To the block position a.

Next, in a state where the setting of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the electromagnetic directional control valve 25 is switched, and the piston rod 21a of the third hydraulic cylinder 21 is switched.
Is driven downward to drive the punch 108 downward to process the forged material 113 as shown in FIG. Then, forging material 113 is plastically deformed. FIG. 21 shows that the load applied to the die spin 104 during forging is the die spin 1
This shows a state where the holding force becomes equal to the holding force of No. 04. Further, when the punch 108 is driven to move downward and the load applied to the die spin 104 becomes larger than the holding power of the die spin 104, as shown in FIG. The die wins, the die spin 104 is retracted, flows into the pin insertion hole 105, and a disposal margin 113a is formed. When the punch 108 moves to a predetermined position, the processing is finished and the forged material 113 is processed to a predetermined size. Note that the disposal allowance 113a of the forging material 113 formed in the pin insertion hole formed by retreating the die spin 104 may be removed later.

During the molding, the holding force of the die spin 104 is set to be larger than the load applied to the die spin 104 when the forging material 113 fills the molding cavity C. The first hydraulic cylinder 19 is used as a holding means for holding the die pin 104, and the hydraulic pressure of the hydraulic cylinder 19 can be set variously. Therefore, when the forging material 113 fills the molding cavity C2, it is applied to the die pin 104. The load can be easily grasped. Therefore, forging can be performed with a minimum necessary forming force.

After the forging, the upper die 102 is returned to the upper limit position, and the die spin 104 is raised to the upper limit position, so that the forging material 113 is taken out from the lower die 101.

FIG. 23 is a perspective view and a cross-sectional view of the product forged as described above, and FIG. 24 is a perspective view of a product completed by removing post-processing allowance 113a by post-processing such as cutting after molding. It is a figure and a sectional view.

Next, according to the forging method described above, the forged material 1
13 has a holding force larger than the load applied to the die spin 104 when the mold cavity C2 is filled.
04, the forged material 113 reliably fills the details of the molding cavity C2, and the excess forged material 113
a flows into the pin insertion hole 105. Therefore, no underfill occurs.

Even when the forging material becomes full during forging, the excess forged material 113a abuts on the die spin 104, overcomes the holding power of the die spin 104, and
22, the forging is caused to flow into the pin insertion hole 105 as shown in FIG. 22, so that the forging is not interrupted due to the sealed high pressure state, and the load on the mold can be reduced.

Further, since the forging is not interrupted and the process is completed up to the final step, a forged product having good dimensional accuracy can be obtained by removing the surplus portion (the waste allowance 113a) after forging.

It is not necessary to strictly control the weight of the forged material 113 in advance, and the disposal allowance can be set so as to be convenient for the post-processing, so that the workability is greatly improved.

By providing a holding force to the die spin 104, a pressure in a direction opposite to the flow direction of the surplus forging material 113a is applied, so that a force acts between the molding hole 106 and the vicinity of the entrance of the pin insertion hole 105. Also, cracking defects due to frictional force generated are less likely to occur.

Since the first hydraulic cylinder 19 is used as holding means for holding the die pin 104, and the pressure of the first hydraulic cylinder 19 is changed to change the holding force of the die pin 104, the holding force of the die pin 104 is appropriately adjusted. be able to.

FIGS. 25 to 31 show a fifth embodiment. A fifth embodiment will be described with reference to FIGS.

The closed forging apparatus 200 includes a main body frame (not shown) and a lower mold 201 provided on the main body frame.
An upper mold 202 is provided on the main body frame so as to face the lower mold 201. The lower die 201 includes a lower die 203,
It has a die pin 204 and a first hydraulic cylinder 19 that holds the die pin 204 and can be driven up and down. The lower die 203 is fixedly disposed, and the upper surface 2 of the lower die 203 is fixed.
Reference numeral 12 denotes a horizontal surface, and a pin insertion hole 205 having a vertical circular cross section for allowing surplus material to flow is formed in the center of the lower die 203. The die pin 204 is mounted in the pin insertion hole 205 so as to be slidable up and down.

At a portion corresponding to the pin insertion hole 205, a lower forming hole 206 is formed near the upper surface of the lower die 203 so as to communicate with the upper end of the pin insertion hole 205. The first hydraulic cylinder 19 is disposed vertically below the die pin 204, and the upper end of the piston rod 19 a of the first hydraulic cylinder 19 is in contact with the die pin 204. The first hydraulic cylinder 19 holds the die spin 204 at the position shown in FIGS. 25, 26, and 27, lowers the die spin 204 while applying a holding force to the die spin 204, and ejects the molded product after molding. 204 can be raised.

The upper die 202 includes an upper die 207, a punch 208, a main hydraulic cylinder 20 for driving the upper die 207 up and down (corresponding to an up / down driving means, corresponding to a second hydraulic cylinder), and raising and lowering the punch 208. A third hydraulic cylinder 21 to be driven. The upper die 207 is vertically movably guided via a guided portion slidably engaged with a guide portion formed on the main body frame, and can be driven up and down by the main hydraulic cylinder 20.

The lower surface 211 of the upper die 207 is formed in a horizontal plane in contact with the upper surface 212 of the lower die 203.
09 is formed.

At a position corresponding to the punch insertion hole 209, an upper molding hole 210 is formed near the lower surface of the upper die 207.
Are formed at the lower end of the punch insertion hole 209 so as to communicate with each other. When the upper die 207 is clamped, the upper die 21
0 communicates with the lower molding hole 206 (see FIG. 26).

The punch 208 is for transmitting a processing force to the material 213, and is formed in a circular cross section. The punch 208 is disposed so as to be vertically movable through a punch insertion hole 209 at the center of the upper die. . The punch 208 is connected to a piston rod 21a of a third hydraulic cylinder 21 disposed above the punch 208, and is driven up and down by the third hydraulic cylinder 21.

Next, the hydraulic control device 18 of the closed forging device 200 will be described. As shown in FIG. 6, this hydraulic control device 18 (corresponding to hydraulic control means)
A hydraulic supply device 22 (having a hydraulic pump, a pump drive motor, an oil tank, and the like) for supplying and discharging hydraulic pressure to one or a plurality of main hydraulic cylinders 29, the first hydraulic cylinder 19, and the third hydraulic cylinder 21, and an electromagnetic direction switching valve A hydraulic circuit including 23 to 25 and electromagnetic proportional relief valves 26 and 27, a plurality of detection switches 28, a control unit 29 for controlling the hydraulic supply device 22 and the electromagnetic valves (23 to 25, 26, 27); Is provided.

The piston rod 20a of the double-acting main hydraulic cylinder 20 is connected to the upper die 207, the piston rod 19a of the double-acting first hydraulic cylinder 19 abuts on the die pin 204, and the double-acting third hydraulic cylinder Hydraulic cylinder 21
Is connected to the punch 208. The electromagnetic directional control valve 23 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the main hydraulic cylinder 20, and the electromagnetic directional control valve 24 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the first hydraulic cylinder 19.
The electromagnetic directional control valve 25 is provided in an oil passage that supplies and discharges hydraulic pressure to and from the third hydraulic cylinder 21.
5 is controlled by the control unit 29.

The electromagnetic proportional relief valve 26 is connected to a supply oil passage to the first hydraulic cylinder 19, and is connected to the first hydraulic cylinder 19
Is supplied with the hydraulic pressure set by the electromagnetic proportional relief valve 26. This electromagnetic proportional relief valve 26 is connected to a control unit 29
Is controlled by Similarly, the electromagnetic proportional relief valve 27 is connected to a supply oil passage to the third hydraulic cylinder 21, and the hydraulic pressure set by the electromagnetic proportional relief valve 27 is supplied to the third hydraulic cylinder 21. The electromagnetic proportional relief valve 27 is controlled by the control unit 29.

A plurality of detection switches 28 are provided on the upper die 2.
A detection switch for detecting an upper limit position and a lower limit position of 07,
A detection switch for detecting the upper limit position and the lower limit position of the punch 208 is included. The control unit 29 has a microcomputer and an input / output interface. The ROM of the microcomputer stores the hydraulic pressure supply device 22 and the solenoid valves (23 to 23) based on a detection signal from the detection switches 28.
25, 26, 27) are input and stored in advance.

A method for forging the forging material 213 with the above configuration will be described with reference to FIGS. 6, 25 to 31.

First, as shown in FIG.
7. Holding the punch 208 at the upper limit position, the lower die 203
The forging material 213 is set in the molding hole 206 of.

Next, as shown in FIG. 26, the electromagnetic directional control valve 23 is switched to extend the piston rod 20a of the main hydraulic cylinder 20, lower the upper die 207, and lower the upper die 201 with respect to the lower die 201. The mold 202 is clamped, and the punch 208 is set in a predetermined positional relationship with respect to the upper die 207.

Next, a predetermined holding force is set on the punch 208, and the punch 208 is held at a predetermined position shown in FIG. In this case, the set pressure of the electromagnetic proportional relief valve 27 is set to a predetermined pressure,
Via the electromagnetic directional switching valve 25 and the third hydraulic cylinder 21,
The height position of the punch 208 is set so that the lower end of the punch 208 is positioned as shown in FIG. 26, and then the electromagnetic directional control valve 25 is switched to the block position a.

Next, in a state where the setting of the electromagnetic proportional relief valve 27 is set to a predetermined pressure, the electromagnetic direction switching valve 24 is switched, and the piston rod 19a of the first hydraulic cylinder 19 is switched.
27, the die pin 204 is driven up to a predetermined position as shown in FIG.
To process. Then, the forged material 213 is plastically deformed.

At this time, the holding force of the punch 208 is set to be larger than the load applied to the punch 208, or the upward movement of the punch 208 is restricted by a mold or the like, so that the punch 208 is moved upward. Can be prevented.

Next, a predetermined holding force is set on the die pin 204, and the die pin 204 is held at a predetermined position shown in FIG. In this case, the set pressure of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the die pin 204 is set to a predetermined position via the electromagnetic direction switching valve 24 and the first hydraulic cylinder 19, and then the electromagnetic direction switching valve 24 is set. To the block position a.

Next, in a state where the setting of the electromagnetic proportional relief valve 26 is set to a predetermined pressure, the electromagnetic directional control valve 25 is switched, and the piston rod 21a of the third hydraulic cylinder 21 is switched.
Is driven downward to drive the punch 208 downward to process the forged material 213 as shown in FIG. Then, the forged material 213 is plastically deformed. FIG. 28 shows that the load applied to die spin 204 during forging is
This shows a state where the holding force becomes equal to the holding force of No. 04. Further, when the punch 208 is driven downward and the load applied to the die spin 204 becomes larger than the holding force of the die spin 204, as shown in FIG. The die wins, the die spin 204 is retracted, flows into the pin insertion hole 205, and a throw-away margin 213a is formed. When the punch 208 moves to a predetermined position, the processing is completed and the forged material 213 fills the inside of the molding cavity C2 and is processed to a predetermined size. Note that the disposal allowance 213a of the forging material 213 formed in the pin insertion hole formed by retracting the die spin 204 may be removed later.

During the molding, the holding force of the die spin 204 is such that the forging material 213 fills the molding cavity C and the excess forging material 213
It is set to flow into. In addition, die spin 2
The first hydraulic cylinder 19 is used as holding means for holding the hydraulic cylinder 04, and the hydraulic pressure of the hydraulic cylinder 19 can be set variously.
, The load on the die spin 204 can be easily grasped. Therefore, forging can be performed with a minimum necessary forming force.

After the completion of the forging, the upper die 202 is returned to the upper limit position, and the die pin 204 is raised to the upper limit position, so that the forging material 213 is taken out from the lower die 201.

FIG. 30 is a perspective view and a sectional view of the product forged as described above, and FIG. 31 is a perspective view of a product completed by removing post-processing allowance 213a by post-processing such as cutting after molding. It is a figure and a sectional view.

Next, according to the forging method described above, the forged material 2
13 is larger than the load applied to the die spin 204 when the molding cavity C2 is filled.
04, the forged material 213 reliably fills the details of the molding cavity C2, and the excess forged material 213
a flows into the pin insertion hole 205. Therefore, no underfill occurs.

Even when the forging material is filled during the forging, the excess forging material 213a contacts the die spin 204, overcomes the holding force of the die spin 204, and
As shown in FIG. 29, the forging flows into the pin insertion hole 205, so that forging is not interrupted due to the sealed high pressure state, and the load on the mold can be reduced.

Further, since the forging is not interrupted and the process is completed up to the final step, a forged product having high dimensional accuracy can be obtained by removing the surplus portion (the allowance 213a) after forging.

It is not necessary to strictly control the weight of the forged material 213 in advance, and the disposal allowance can be set so as to be convenient for the post-processing, which greatly contributes to the improvement of workability.

By providing the die pin 204 with a holding force, a pressure in a direction opposite to the flow direction of the surplus forging material 213a is applied, so that an action is provided between the molding hole 206 and the vicinity of the entrance of the pin insertion hole 205. Also, cracking defects due to frictional force generated are less likely to occur.

Since the first hydraulic cylinder 19 is used as holding means for holding the die pin 204, and the pressure of the first hydraulic cylinder 19 is changed to change the holding force of the die pin 204, the holding force of the die pin 204 is appropriately adjusted. be able to.

[Brief description of the drawings]

FIG. 1: Main parts of lower and upper dies of closed forging device (initial state)
FIG.

FIG. 2 is a vertical cross-sectional view of a main part (in the middle of molding) of a lower die and an upper die of a closed forging device.

FIG. 3 is a vertical cross-sectional view of a main part (forming completion state) of a lower die and an upper die of the closed forging device.

FIG. 4 is a perspective view and a cross-sectional view of a product (with discarding allowance) made by the closed forging method according to the present invention.

FIG. 5 is a perspective view and a cross-sectional view of a product prepared by the closed forging method according to the present invention and from which a disposal allowance has been removed.

FIG. 6 is a configuration diagram of a hydraulic control device of the closed forging device.

FIG. 7 is a main portion of the lower and upper dies of the closed forging device (initial state).
FIG.

FIG. 8 is a longitudinal cross-sectional view of a main part (mold clamping state) of a lower die and an upper die of the closed forging device.

FIG. 9 is a vertical cross-sectional view of a main part of the lower die and the upper die (in the middle of molding) of the closed forging device.

FIG. 10 is a vertical cross-sectional view of a main part (forming completion state) of a lower die and an upper die of the closed forging device.

FIG. 11 is a perspective view and a cross-sectional view of a product (with a throw-away allowance) made by the closed forging method according to the present invention.

FIG. 12 is a perspective view and a cross-sectional view of a product prepared by the closed forging method according to the present invention and from which a disposal allowance has been removed.

FIG. 13 is a longitudinal sectional view of a main part (initial state) of a lower die and an upper die of the closed forging device.

FIG. 14 is a vertical cross-sectional view of a main part (in the middle of molding) of a lower die and an upper die of the closed forging device.

FIG. 15 is a vertical cross-sectional view of a main part (forming completion state) of a lower die and an upper die of the closed forging device.

FIG. 16 is a perspective view and a cross-sectional view of a product (with a throw-away allowance) made by the closed forging method according to the present invention.

FIG. 17 is a perspective view and a cross-sectional view of a product prepared by the closed forging method according to the present invention and from which a disposal allowance has been removed.

FIG. 18 is a longitudinal sectional view of a main part (initial state) of a lower die and an upper die of the closed forging device.

FIG. 19 is a longitudinal cross-sectional view of a main part (mold clamping state) of a lower die and an upper die of the closed forging device.

FIG. 20 is a longitudinal sectional view of a main part (forming start state) of a lower die and an upper die of the closed forging device.

FIG. 21 is a longitudinal sectional view of a main part (in the middle of molding) of a lower die and an upper die of the closed forging device.

FIG. 22 is a longitudinal sectional view of a main part of a lower die and an upper die (forming completion state) of the closed forging device.

FIG. 23 is a perspective view and a cross-sectional view of a product (with a throw-away allowance) made by the closed forging method according to the present invention.

FIG. 24 is a perspective view and a cross-sectional view of a product prepared by the closed forging method according to the present invention and from which a disposal allowance has been removed.

FIG. 25 is a longitudinal sectional view of a main part (initial state) of a lower die and an upper die of the closed forging device.

FIG. 26 is a vertical cross-sectional view of a main part (mold clamping state) of a lower die and an upper die of the closed forging device.

FIG. 27 is a longitudinal sectional view of a main part (forming start state) of a lower die and an upper die of the closed forging device.

FIG. 28 is a longitudinal sectional view of a main part (in the middle of molding) of a lower die and an upper die of the closed forging device.

FIG. 29 is a longitudinal sectional view of a main part of a lower die and an upper die (forming completion state) of the closed forging device.

FIG. 30 is a perspective view and a sectional view of a product (with a throw-away allowance) made by the closed forging method according to the present invention.

FIG. 31 is a perspective view and a cross-sectional view of a product produced by the closed forging method according to the present invention and from which a disposal allowance has been removed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Forging apparatus 2 Lower die 3 Upper die 4 Lower die 5 Die spin 8 Upper die 9 Upper outer punch 18 Hydraulic control device 19 1st hydraulic cylinder 20 Main hydraulic cylinder 21 3rd hydraulic cylinder 22 Hydraulic supply device 23-25 Electromagnetic direction switching valve 26, 27 Electromagnetic proportional relief valve 28 Detection switches 29 Control unit 30 Forging device 31 Lower die 32 Upper die 33 Lower die 34 Diespin 37 Upper die 38 Punch 44 Forging device 45 Lower die 46 Upper die 47 Lower die A 48 Lower die B 49 Ring die spin 52 Upper die 55 Upper outer punch

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E087 AA03 AA05 AA08 AA09 CA14 DB03 DB24 EA12 EC13 EC50 GA02 GA03 GB02

Claims (14)

[Claims] 1. A closed forging method in which a material disposed inside a closed space is pressed by a part of an inner wall of the closed space so as to fill the closed space, wherein the volume of the material is a first volume. When the volume is equal to or less than the volume, the closed space volume is made equal to the first volume by advancing a part of the inner wall to the first position, and the volume of the material is larger than the first volume. In
A closed forging method in which a part of the inner wall is advanced to a first position and another part of the inner wall of the closed space is retracted to make the volume of the closed space equal to the volume of the material. 2. The closed forging method according to claim 1, wherein when the closed space volume is formed to be equal to the volume of the material, the volume of the formed product is equal to the first volume. A closed forging method including a step of removing an excess portion. 3. A closed forging method in which a material disposed inside a closed space is pressed by a part of an inner wall of the closed space to fill the inside of the closed space. , The filling of the material into the closed space is completed, and the internal pressure of the closed space when a part of the inner wall is advanced to the first position is the first pressure. If greater than, the other part of the inner wall of the closed space is retracted, and the internal pressure of the closed space when a part of the inner wall is advanced to the first position is equal to or less than the first pressure. If
A closed forging method that does not retreat other portions of the inner wall of the closed space. 4. In the step of causing a part of the inner wall to advance to the first position, when the internal pressure fluctuation of the closed space is in a transient state, the internal pressure of the closed space is larger than the first pressure. Even in the case, the other part of the inner wall of the closed space is not retracted, and when the internal pressure fluctuation of the closed space is in a steady state, when the internal pressure of the closed space is larger than the first pressure, the closed space 4. The closed forging method according to claim 3, wherein the other part of the inner wall is retracted. 5. When a biasing means is provided for biasing another portion of the inner wall of the closed space in a direction to prevent the inner space from retreating, and when the internal pressure fluctuation changes from a transient state to a steady state,
The closed forging method according to claim 4, wherein the urging force of the urging means is reduced. 6. The closed forging method according to claim 4, wherein the determination whether the internal pressure fluctuation is in a transient state or a steady state is performed based on detection of a position of a part of an inner wall of the closed space. 7. The blockage according to claim 4, wherein the determination as to whether the internal pressure fluctuation is in a transient state or a steady state is made based on an elapsed time after a part of the inner wall of the closed space is moved. Forging method. 8. The other portion of the inner wall has been advanced to a second position while pressurizing the material before a portion of the inner wall has advanced to the first position. ~
8. The closed forging method according to any one of 7 above. 9. A forging die having a closed space, wherein a material disposed inside the closed space is pressed by a part of an inner wall of the closed space, wherein another part of the inner wall of the closed space is provided inside the closed space. A forging die configured to be retracted as the material arranged in the overhang protrudes. 10. The forging die according to claim 9, wherein said retreatable portion is held by a predetermined urging force. 11. The forging die according to claim 10, wherein said urging force is variable. 12. The device according to claim 9, wherein the other part of the inner wall is retreatable in conjunction with a part of the inner wall.
Forging die described in the item. 13. The forging die according to claim 9, wherein a part of the inner wall is a punch. 14. The forging die according to claim 9, wherein a part of the inner wall is urged by hydraulic pressure.