JPH0280148A - Method and device for extrusion working - Google Patents

Abstract

PURPOSE:To remarkably reduce the maximum load for working on a die by placing a pressure member in a hole part of a cylindrical punch or the outside periphery, bringing a release end to extrusion working thereby and reducing pressure of the pressure member before working is ended. CONSTITUTION:As shown on the left side in the figure of a working device, hydraulic pressure is supplied to a hydraulic cylinder 43 from a hydraulic pressure supply piping 7, a cylindrical punch 25 is moved toward a stock 55 in a state that prescribed pressure is applied to the stock 55 side of a pressure member 39 through an intermediate pin 41 and extrusion working is executed. When the cylindrical punch 25 approaches the bottom dead center, pressure to the pressure member 39 is eliminated by switching the hydraulic cylinder 43 to a hydraulic pressure exhaust piping 49, and it becomes a state shown on the right side in the figure of the working device. In such a way, it can be prevented that pressure of the cylindrical punch 25 and pressure of the pressure member 39 are compounded and applied to a die, and the maximum load applied to the die can be reduced remarkably.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an extrusion processing method and an apparatus thereof, and particularly relates to an extrusion processing method and an apparatus thereof, and in particular, to a product having a central convex portion in the center and a cylindrical portion on the outside thereof. The present invention relates to an extrusion processing method for molding and an apparatus therefor.

(Prior Art) For example, as shown in FIG. 6, in extrusion molding of a product having a central convex portion 11 at the center and a cylindrical portion 13 on the outside, the length of the central convex portion 11 is cylindrical. If the length is longer than the length of the central convex part 13, a predetermined normal pressure is separately applied to the central convex part 11 during extrusion molding, thereby adjusting the length of the central convex part 11 and the cylindrical part 13. ing.

[Problem to be solved by the invention]

However, in such conventional extrusion processing methods,
Since normal pressure is applied to the central convex portion 11, as shown in FIG. 7, the load acting on the mold increases, the life of the mold decreases, and molding accuracy decreases due to deformation of the mold. There is a problem.

In particular, in extrusion processing where the bottom thickness is reduced, the load increases significantly near the bottom dead center, but if normal pressure is applied, this will increase further.

That is, when normal pressure is not applied, the maximum load acting on the mold is X at the bottom dead center, as shown by the solid line in Figure 7, but when normal pressure is applied, the maximum load acting on the mold is X as shown in the figure. As shown by the two-dot chain line, it becomes Y and the load acting on the mold increases significantly.

The present invention solves the above-mentioned problems, and aims to provide an extrusion method and apparatus that can significantly reduce the maximum load acting on a mold compared to the conventional method.

[Means to solve the problem]

In the extrusion processing method according to the present invention, a material housed in a die is extruded using a cylindrical punch having a hole in the center, a central convex portion is formed by the hole of the cylindrical punch, and the material is extruded into a die. In an extrusion processing method in which a cylindrical part is formed by an inner periphery and an outer periphery of a cylindrical punch, a pressure member is arranged in the hole or outer periphery of the cylindrical punch, and the pressure member is used to press the central convex part or the cylindrical part. The extrusion process is performed while the open end of the press member is pressed at a predetermined pressure, and the pressure of the pressure member is reduced or removed before the extrusion process is completed.

Further, the extrusion processing apparatus according to the present invention extrudes the material housed in the die using a cylindrical punch having a hole in the center, and forms a central convex portion by the hole of the cylindrical punch. In an extrusion processing device that forms a cylindrical part by the inner periphery of the die and the outer periphery of the cylindrical punch, a pressure member is disposed in the hole or outer periphery of the cylindrical punch, and the pressure member is applied to the material side at a predetermined pressure. A pressurizing means for applying pressure is provided, and a pressure releasing means is further provided for reducing or removing the pressure of the pressurizing means before the end of the extrusion process.

[For production]

In the extrusion processing method of the present invention, a pressure member is placed in the hole or the outer periphery of the cylindrical punch, and the pressure member presses the central convex portion or the open end of the cylindrical portion with a predetermined pressure, and then extrudes. However, the pressure of the pressure member is reduced or removed before the extrusion process is completed.

Further, in the extrusion processing apparatus according to the present invention, a pressure member is arranged in the hole or the outer periphery of the cylindrical punch, and by pressing the pressure member with the pressure means, the central convex part or the open end of the cylindrical part is pressed. The extrusion process is carried out under a predetermined pressure, but the pressure of the pressure member is reduced or removed by the pressure release means before the extrusion process is completed.

〔Example〕

Hereinafter, details of the present invention will be explained using the drawings.

FIG. 1 shows an embodiment of the extrusion apparatus of the present invention, with the left side of the figure showing the initial state of extrusion, and the right side of the figure showing the state at the end of extrusion.

In the figure, reference numeral 21 indicates an upper die set fixed to the lower surface of the slide, and this upper die set 21
A cylindrical punch 25 is attached to the lower surface of the
is fixed.

On the other hand, in the figure, reference numeral 27 indicates a lower die set, and a die holder 29 is fixed to the upper surface of this lower die set 27, and a die 31 is placed on the upper surface of this die holder 29. has been done.

The die 31 is fixed by a die holder 33 fixed to the lower die set 27, and has a counter punch 35 inside.
The tip of the is inserted.

Therefore, in this embodiment, the hole 37 of the cylindrical punch 25
A pressure member 39 is inserted into.

The lower end of an intermediate pin 41 inserted through the upper die set 21 is in contact with the upper end of the pressure member 39 .

The upper end of the intermediate pin 41 is inserted into a hydraulic cylinder 43, which is a pressurizing means fixed to the upper surface of the upper die set 21, and is in contact with the lower surface of a piston 45 within the hydraulic cylinder 43.

A hydraulic pressure supply pipe 47 and a hydraulic discharge pipe 49 are opened in the hydraulic cylinder 43, and these pipes communicate with a hydraulic pressure source 53 via a solenoid valve 51 which is a pressure release means.

In the extrusion processing apparatus configured as described above, as shown on the left side of FIG.
The boat of the solenoid valve 51 is switched so that hydraulic pressure is supplied from 7, and the slide is moved downward while the pressure member 39 is urged toward the material 55 at a predetermined normal pressure via the intermediate pin 41. Then, extrusion processing is performed by moving the cylindrical punch 25 toward the material 55.

When the slide approaches the bottom dead center, this is detected by an appropriate means such as a limit switch, and this detection signal causes the hydraulic cylinder 43 to be disconnected from the hydraulic discharge pipe 49, as shown on the right side of FIG. The port of the electromagnetic valve 51 is switched so that hydraulic pressure is supplied, and the pressure on the pressure member 39 is removed.

Figure 2 shows the change in load in the extrusion processing apparatus configured as described above.As shown by the dashed line in the figure, normal pressure is applied up to the position near the bottom dead center. ,
After the solenoid valve 51 is switched, normal pressure is released.

That is, in the extrusion processing apparatus configured as described above, the pressure member 39 is arranged in the hole 37 of the cylindrical punch 25, and the pressure member 39 is pressed against the material 55 side with a predetermined pressure. A hydraulic cylinder 43 as a means is provided, and an electromagnetic valve 51 as a pressure release means for removing the pressure of the hydraulic cylinder 43 before the end of the extrusion process is provided. This means that in extrusion processes where the maximum load is applied near the bottom dead center, especially in extrusion processes where the bottom thickness is thin, the maximum load acting on the mold can be significantly reduced compared to before. Become.

In the extrusion processing method of the present invention, the cylindrical punch 25
A pressure member 39 is placed in the hole 37 of the pressure member 39 .
As a result, the open end of the central convex portion 11 is extruded with a predetermined pressure applied, and the pressure of the pressure member 39 is removed before the end of the extrusion process. This allows the maximum load acting on the mold to be significantly reduced compared to the conventional method.

Further, in the extrusion processing method of the present invention, the heights of the central convex portion 11 and the cylindrical portion 13 can be adjusted by appropriately adjusting the timing of applying pressure to the pressure member 39 and releasing the pressure. Become.

(a) to (0) in FIG. 3 illustrate products to which the extrusion processing method of the present invention can be applied, and (a), (b), (
C), (d), and (Q) are produced by backward extrusion molding (f
), (g), (h) are further formed by forward extrusion, and (e), (i).

N), (k), (1), (m), (n
) is molded by front-to-back extrusion molding.

In addition, (b), (g), (i), (j), (1), (n
) and (o), by applying the method of the present invention, the load can be reduced and the following effects can be obtained.

That is, when extruding a product having a shape as shown in FIG. Sink marks may occur at the base of the convex portion 11, or
Although the central convex part 11 may be separated, the method of the present invention applies a large amount of pressure to the central convex part 11 at the start of machining, suppresses the flow of material toward the central convex part, and closes the central convex part near the bottom dead center. By releasing this pressure, as shown in FIG. 5, plastic flow toward the central convex portion 11 occurs near the bottom dead center, making it possible to effectively solve the above-mentioned problem.

In the embodiments described above, the hydraulic pressure is suddenly released by the electromagnetic valve 51, but the present invention is not limited to such embodiments, and a throttle or the like may be arranged in the hydraulic pressure supply pipe 47, etc. By doing so, the hydraulic pressure can be gradually released, and in this case, it is possible to equalize the load.

Further, in the embodiments described above, an example was described in which pressure was applied to the pressure member 39 using the hydraulic cylinder 43, but the present invention is not limited to such an embodiment. Of course, it is also possible to apply pressure to the pressure member 39 by mechanical means.

Furthermore, in the embodiment described above, an example was described in which the pressure member 39 was arranged in the hole 37 of the cylindrical bunch 25 and pressure was applied to the central convex part 11, but the present invention is not limited to such an embodiment. Of course, the pressure member 39 may be placed outside the cylindrical bunch 25 to apply pressure to the cylindrical portion 13.

〔Effect of the invention〕

As described above, in the extrusion processing method of the present invention, a pressure member is arranged in the hole or the outer periphery of the cylindrical bunch, and the pressure member presses the central convex part or the open end of the cylindrical part with a predetermined pressure. Since the extrusion process was carried out in a state where the In such extrusion processing, the maximum load acting on the mold can be significantly reduced compared to conventional methods.

Further, in the extrusion processing apparatus of the present invention, a pressure member is arranged in the hole or the outer periphery of the cylindrical bunch, and a pressure means is provided for pressing the pressure member against the material side with a predetermined pressure. Since we have provided a pressure release means that removes the pressure from the pressurizing means before the extrusion process ends, the pressure from the pressurizing means is removed before the extrusion process ends, making it possible to avoid machining in which the maximum load is applied near the bottom dead center. This has the advantage that the maximum load acting on the mold can be significantly reduced compared to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the extrusion processing apparatus of the present invention. FIG. 2 is a graph showing changes in the load of the extrusion processing apparatus shown in FIG. FIG. 3 is an explanatory diagram showing an example of a product to which the extrusion processing method of the present invention is applied. FIGS. 4 and 5 are explanatory diagrams for explaining other effects of the method of the present invention. FIG. 6 is an explanatory diagram showing a conventional extrusion processing method. FIG. 7 is a graph showing changes in load in a conventional extrusion method. [Explanation of symbols of main parts] 11...Central convex part 13...Cylindrical part 25...Cylindrical bunch 31...Gui 37...Hole part 39...Press member 43... ... Hydraulic cylinder (pressurizing means) 51 ... Solenoid valve (pressure release means) 55 ... Material. Patent Applicant AIDA Engineering Co., Ltd. (C1) (f) (b) (C) (h) i) j) ) (of(m) (n)

Claims (2)

[Claims] (1) The material to be accommodated in the die is extruded using a cylindrical punch having a hole in the center, and the hole of the cylindrical punch forms a central protrusion, and the inner periphery of the die and the cylindrical punch In an extrusion processing method for forming a cylindrical part with an outer periphery, a pressure member is arranged in the hole or outer periphery of the cylindrical punch, and the pressure member applies a predetermined pressure to the central convex part or the open end of the cylindrical part. extrusion processing under pressure,
An extrusion processing method characterized by reducing or removing the pressure of the pressure member before the end of extrusion processing. (2) The material accommodated in the die is extruded using a cylindrical punch having a hole in the center, and the hole of the cylindrical punch forms a central protrusion, and the inner periphery of the die and the cylindrical punch In an extrusion processing device that forms a cylindrical part by an outer periphery, a pressure member is disposed in the hole or outer periphery of the cylindrical punch, and a pressure means is provided for pressing the pressure member against the material side with a predetermined pressure. An extrusion processing apparatus further comprising a pressure release means for reducing or removing the pressure of the pressure means before the end of extrusion processing.