JPS6238062B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a closed forging device for performing closed forging.

(Problems of the Prior Art to be Solved by the Invention) In closed forging, a closed mold is first constructed, and then a punch is inserted into the mold to pressure-form the material in the mold. When this closed forging is carried out using a mechanical single-acting press, a double-acting mechanism is incorporated into the mold or the like in order to obtain the double-acting action of the closed forging with one press operation.

However, in conventional wedge-type double-acting mechanisms and link-type double-acting mechanisms, the size of the closing mold and the entry position of the punch are determined mechanically, which results in uneven product thickness due to the amount of material used. This resulted in problems such as decreased accuracy and shortened mold life. Further, in the conventional spring-type double-acting mechanism in which the lower mold is vertically movably supported by a disc spring within a guide, problems such as wear and seizure are likely to occur between the lower mold and its vertically movable guide. Since it is a disc spring, the vertical movement stroke of the lower mold is small, and since it is impossible to change the lower mold push-up load, there are problems such as restrictions on the steel type of material that can be processed.

(Object of the Invention) The present invention was devised in order to solve the above-mentioned problems of the conventional art. The upper power of the inner punch can be automatically supplied hydraulically by the downward movement of the slide, and variations in material weight can be absorbed by changing the thickness of the burr in the hole in the center of the molded product formed by the upper and lower inner punches. The purpose is to provide a closed forging device.

(Structure of the Invention) In the closed forging device of the present invention, an upper die holder body mounted on a slide is provided with an operating cylinder capable of lowering an upper outer punch and an upper inner punch, and each of the operating cylinders is used for setting punch pressure force. A hydraulic circuit equipped with a relief valve is connected, and the lower die holder body mounted on the head is equipped with an operating cylinder that can raise the lower inner punch, and a lower cylinder into which the upper outer punch can be inserted and which can stop the lowering of the outer punch. A mold, a lower outer punch fitted into the lower mold, and a hydraulic pressure generating device that generates hydraulic pressure by the downward movement of the slide, the hydraulic pressure generating device being attached to the lower inner punch operating cylinder, It is characterized by being connected to a hydraulic circuit equipped with a relief valve for setting punch pressure force.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

An upper die holder main body 2 is attached to the slide 1 of the mechanical single-action press, and a ram is fitted inside the upper die holder main body 2 so as to be movable up and down.
Working cylinders 3, 4 are provided. An upper outer punch 6 is attached to the lower end of the upper outer ram 5 of the operating cylinder 3.

An upper inner punch 8 is attached to the lower end of the upper inner ram 7 fitted into the operating cylinder 3, and is fitted into the upper outer punch 6 so as to be movable up and down. Hydraulic pressure circuits 11 and 12 each having relief valves 9 and 10 for setting punch pressure force are connected to the actuation cylinders 3 and 4.

Further, a lower die holder main body 14 is attached to the bed 13 of the mechanical single-action press, and the upper outer punch 6 has a cylindrical shape into which the upper outer punch 6 can be inserted and which can stop the upper outer punch 6. A lower mold 15 is attached. A lower outer punch 16 is mounted in the lower part of the lower mold 15 so as to be movable upward, and placed on the bed 13.
Inside the lower die holder main body 14, there is a discharge cylinder 18 equipped with a knockout pin 17 that can move the lower outer punch 16 upwardly, and a ram is fitted into the piston 19 of the discharge cylinder 18 and the lower outer punch 16 so as to be able to move vertically. An operating cylinder 20 and a vertical cylinder type hydraulic pressure generating device 21 having a ram protruding above the lower die holder main body 14 are provided.

A lower inner punch 23 is attached to the upper end of the ram 22 of the operating cylinder 20. This actuating cylinder 20 includes a hydraulic circuit 25 equipped with a relief valve 24 for setting the punch pressure force, and a hydraulic pressure generating device 2.
1 is connected.

The hydraulic circuits 11, 12, and 25 are configured so that insufficient liquid is replenished by the same hydraulic pump 26 via a check valve 27.

The hydraulic pressure generating device 21 is configured to generate hydraulic pressure by pushing down a ram 29 with an operating rod 28 hanging from the upper die holder main body 26 when the slide 1 is being moved downward.

A hydraulic pump 30 is connected to the discharge cylinder 18 via a pressure reducing valve 31 with relief and an electromagnetic switching valve 32.

(Function) The upper outer punch 6 and the upper inner punch 8 are placed at the lower limit position by the actuating cylinders 3 and 4, which are held in an extended operating state by hydraulic circuits 11 and 12, respectively. The operating cylinder 20 is simply supplied with a constant flow of liquid by the hydraulic pressure circuit 25 so that the lower inner punch 23 can be moved upward by supplying the amount of liquid by the hydraulic pressure generating device 21 . Therefore, the lower inner punch 23 is also placed at the lower limit position.

In this state, when the single-acting press is driven and the slide is moved downward, the upper outer punch 6 is fitted into the lower mold 15 together with the upper inner punch 8, and the upper outer punch 6 is inserted into the lower mold 15. It is stopped by engaging with the inner peripheral portion of the upper end. At this time, a complete closed mold is constituted by the lower mold 15, the upper outer punch 6, the upper inner punch 8, the lower outer punch 16, and the lower inner punch 23, and the upper outer punch 6 is attached to the material M in the closed mold. The upper inner punch 8 comes into contact with the upper inner punch 8.

When the slide 1 further descends, the pressure in the liquid chamber of the operating cylinder 3 that supports the upper outer punch 6 increases, and the pressure exceeding the punch pressure set by the relief valve 9 is released to the outside by the relief valve 9, and the pressure in the liquid chamber of the operating cylinder 3 that supports the upper outer punch 6 increases. 3 is shortened as the slide 1 is lowered. On the other hand, the upper inner punch 8 comes into contact with the material M and receives downward resistance, and the pressure in the liquid chamber of the actuating cylinder 4 that supports the upper inner punch 8 increases until it reaches the punch pressure set by the relief valve 10. In this case, upper inner punch 8 is slide 1
The material M continues to descend, compressing and deforming the material M.

At the same time, as the slide 1 descends, the ram 29 of the hydraulic pressure generating device 21 is pushed down by the actuating rod 28, and the amount of liquid is supplied from the ram 29 into the liquid chamber of the actuating cylinder 20. The operating cylinder 20 is extended until the pressure reaches the punch pressure set by the relief valve 24. The lower inner punch 23 is connected to this operating cylinder 2.
0, and the material M is compressed and deformed from below.

Here, by the time slide 1 reaches the dead point,
If the material M completely fills the closed mold, the pressure in the liquid chamber of the actuating cylinder 4 and the pressure in the liquid chamber of the actuating cylinder 20 (pressure in the liquid chamber of the liquid pressure generator 21) will be controlled by the relief valves 10 and 24, respectively. The punch pressure increases higher than the punch pressure set in , and the relief valve 10,
24, the movement of the upper inner punch 8 and lower inner punch 23 stops at this time.

Therefore, closed forging is performed by the closed type configuration operation and the compressive deformation operation of the material M by the upper inner punch 8 and the lower inner punch 23, and if there is variation in the weight (volume) of the material M, the variation will be The burr is absorbed by the thickness of the hole in the center of the molded product formed by the upper and lower inner punches 8 and 23, and does not affect the thickness of the molded product.

After the molding operation is completed, when the slide 1 starts to rise, the pressure in the liquid chambers of the working cylinders 3, 4, 20 decreases, but the working cylinders 3, 4, 20 are supplied with the insufficient liquid amount by the hydraulic pump 26. Therefore, the upper outer punch 6 and the upper and lower inner punches 8, 2
3 is returned to its original position.

On the other hand, when the amount of working fluid is supplied from the hydraulic pump 30 to the discharge cylinder 18 by the electromagnetic switching valve 32, the lower outer punch 16 is moved upward in the lower mold 15 by the discharge cylinder 18 via the knockout pin 17, so that the molding The product is ejected from the lower mold 15 by the lower outer punch 16. After discharging the molded product, the electromagnetic switching valve 32 is switched in the opposite direction to return the lower outer punch 16 to its original position.

The above is one cycle of closed forging.

(Effects of the Invention) As described above, the present invention allows the pushing pressure (punch pressure force) of the upper and lower inner punches to be freely set using the relief valve, and thereby allows the hole in the center of the molded product formed by the upper and lower inner punches to Since the structure is such that variations in material weight can be absorbed by changing the middle burr thickness, the thickness of the molded product can be kept constant. This prevents overload from acting on the mold and protects it. Forming is easy because the material is pressure-formed from above and below using upper and lower inner punches. Closed forging using existing single-acting mechanical presses is easily possible.

[Brief explanation of the drawing]

The drawing is a schematic view showing the closed forging device of the present invention in a closed die configuration. 1...Slide, 2...Upper die holder body,
3, 4, 20... Operating cylinder, 5... Upper outer ram, 6... Upper outer punch, 7... Upper inner ram, 8... Upper inner punch, 9, 10, 24...
Relief valve, 11, 12, 25...hydraulic pressure circuit, 1
3...Bed, 14...Lower die holder body, 15
...Lower mold, 16...Lower outer punch, 17...
Knockout pin, 18...Ejection cylinder, 19
... Piston, 21 ... Hydraulic pressure generator, 22,2
9... Ram, 23... Lower inner punch, 26,3
0...Hydraulic pump, 27...Check valve, 28...
...Operating rod, 31...Pressure reducing valve, 32...Solenoid switching valve.

Claims (1)

[Claims] 1 Attach the upper die holder body attached to the slide.
An operating cylinder capable of lowering the upper outer punch and the upper inner punch is provided, a hydraulic circuit equipped with a relief valve for setting the punch pressure force is connected to each of the operating cylinders, and the lower die holder body mounted on the bed is connected to the operating cylinder. A working cylinder capable of raising a lower inner punch, a lower mold into which an upper outer punch can be inserted and which can stop the outer punch from descending, a lower outer punch fitted into the lower mold, and a hydraulic pressure generated by the downward movement of the slide. and a hydraulic pressure generating device that generates a pressure, and the hydraulic pressure generating device and a hydraulic pressure circuit equipped with a relief valve for setting punch pressure force are connected to the lower inner punch operating cylinder. Forging equipment.