JP2021074767A - Double-acting press die - Google Patents

Abstract

To provide a double-acting press die that can shorten a distance between upper and lower dies by driving a punch separately inside a die and can be fitted to an existing press device.SOLUTION: A double-acting press die includes: a deep drawing die for disposing a blank between an upper die and a lower die and molding the blank into a cylindrical shape; and a drawing punch part stored in any one of the dies and projecting only in performing drawing.SELECTED DRAWING: Figure 1

Description

The present invention relates to a double-acting press die that can be mounted on a compact press machine that can handle deep drawing.

A press device is used to mold the metal plate. The press device is also used in the process of forming a cylinder from a metal plate called drawing, but as the drawing depth becomes deeper, the lower bolster and upper slide are used to take out the work piece after drawing. A larger press device was needed because the distance had to be increased.

For example, Patent Document 1 discloses a vertically double-acting hydraulic press device for deep drawing, in which a deep drawing is performed by a step of lowering an upper ram slide on which a die is attached and a step of raising a lower punch. How to do it is shown. This device requires a hydraulic device on the top and bottom, and has a problem that the press device is large and expensive.

Further, Patent Document 2 discloses a method for forming an opposed hydraulic pressure of a container. In this method, it is shown that a tubular container is formed by lowering a punch from the upper side in a water chamber arranged on the lower side of the device. In the case of this method, since a dedicated press device having a water chamber is required, there is a problem that production flexibility is lacking.

Japanese Unexamined Patent Publication No. 52-106175 Japanese Unexamined Patent Publication No. 8-150420

In view of the above-mentioned problems, the present invention provides a double-acting press die that can reduce the distance between the upper and lower dies by separately driving the punch in the die and can be mounted on an existing press die. Is the subject.

In order to solve the above problems, the double-acting press die according to the present invention is a deep drawing die in which a blank is arranged between the upper die and the lower die and the blank is molded into a tubular shape. It is housed in the mold of the above, and is characterized in that it is configured to protrude only when squeezing.

It is desirable that the squeeze punch portion is housed in the mold and the punch tip portion does not protrude at least from the outer surface of the blank holder. Further, it is also preferable that the drawing punch is configured to protrude from the die near the bottom dead center of the pressing operation with the die attached to the press machine.

In the double-acting press die according to the present invention, since the punch is stored in the die and the punch is projected from the blank holder when necessary, the drawing is performed, so that the distance between the upper and lower dies can be shortened. Further, since it is a die, it can be mounted on an existing press device, and deep drawing can be performed with a compact press device.

Hereinafter, preferred embodiments of the present invention will be described based on examples. FIG. 1 shows an example of a double-acting press die according to the present invention. This figure shows a state in which a die set including an upper die 11 and a lower die 21 is attached to the press main body 1. The upper mold 11 is fixed to the slide 2 of the press machine 1, and the punch 13 is arranged in the stored state. The punch 13 is configured to be vertically movable with respect to the upper die 11 by the punch actuator 12. Further, on the lower surface side of the upper die 11, a blank holder 15 is arranged with a certain distance A except for the movable range of the punch 13, and the blank holder shock absorber 14 is configured to be movable up and down within a certain range. ing. On the other hand, the lower mold 21 is fixed to the bolster 3 of the press machine 1 and has a hole for deep drawing. A knockout plate 22 is arranged in this hole, and is configured to be vertically movable by a knockout device 23.

Next, the operation of the double-acting press die according to the present invention will be described. FIG. 3 shows a series of operation explanatory views for one embodiment of the present invention as a cross-sectional view of a main part. (1) indicates the state before operation. The punch 13 is housed in the upper die 11, and is arranged so that the tip end portion of the punch 13 is located on substantially the same surface as the lower surface of the blank holder 15. Further, a blank 31 is arranged on the lower mold 21. (2) indicates the initial state of the deep drawing operation. The upper mold 11 descends to the surface of the blank 31, and the blank holder 15 holds the blank 31. In (3), while the blank holder 15 holds the blank 31, only the punch 13 further lowers to perform deep drawing. (4) is the state after the deep drawing is completed, the punch 13 is housed in the upper mold 11, the upper mold 11 rises, and the knockout plate pushes up to the mold 21 on which the molded product 32 is formed. In the above operation, the punch actuator operates after the blank holder holds the blank, at which stage the press reaches near bottom dead center and moves slowly. By driving the punch at this stage, more uniform drawing becomes possible.

A comparison between the double-acting press die according to the present invention and the conventional die will be described. In the deep drawing, as can be seen from (4) in FIG. 3, a distance equal to or longer than the length of the deep drawing is required between the upper mold (or blank holder) and the lower mold in order to take out the molded product. A cross-sectional view of a conventional mold is shown in FIG. In this mold, since the punch 13 is fixed on the upper mold 11, the length of the upper mold 11 becomes long. Further, the stroke of the press is a distance A (punch length) + a distance B (distance between dies). Therefore, C (deep drawing length) is less than half of A + B, and is generally about one-third. On the other hand, in the mold according to the present invention shown in FIG. 1, since the punch 13 is housed in the mold, the distance A can be made as small as possible. Therefore, when the die is mounted on a press machine having the same distance between the slide and the bolster, the die according to the present invention enables deeper drawing. Alternatively, when drawing at the same depth, according to the mold of the present invention, it is possible to perform drawing with a more compact press machine.

As described above, in the double-acting press die according to the present invention, deeper drawing is possible by storing the punch in the upper die and driving it only when necessary, or when drawing at the same depth. A more compact press machine can be used. Further, since the die according to the present invention can be mounted on an existing press machine, it is not necessary to use a press machine having a long stroke for deep drawing. As described above, it is very useful in deep drawing press molding.

It is a side sectional view which shows the Example of the double-acting press die by this invention. It is a side sectional view which shows the conventional press die. It is explanatory drawing which shows the operation state of the double-acting press die of this invention.

1: Press machine body 2: Slider 3: Bolster 11: Upper mold 12: Punch actuator 13: Punch 14: Blank holder shock absorber 15: Blank holder 21: Lower mold 22: Knockout plate 23: Knockout device 31: Blank 32: Molding Later product

Claims (3)

In a deep drawing die in which a blank is placed between the upper die and the lower die and the blank is molded into a tubular shape, the drawing punch portion is housed in one of the dies, and only when drawing is performed. A double-acting press die characterized by being configured to protrude. The double-moving press die according to claim 1, wherein the drawing punch portion is housed in the mold, and the punch tip portion does not protrude at least from the outer surface of the blank holder. The double-acting press according to claim 1 or 2, wherein the drawing punch is configured to protrude from the die in the vicinity of the bottom dead center of the pressing operation with the die attached to the press machine. Mold.

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