JPS6138793Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a back pressure device for applying back pressure in the opposite direction to the pressurizing force during processing on the slide of a press. The invention relates to the above device.

As is well known, when punching is performed using a press, a breakthrough phenomenon occurs. A backpressure device is intended to prevent this phenomenon. Also, with hydraulic presses, unlike mechanical presses, the lower limit of the slide stroke is not positioned.
Even if a lower limit stop command is issued, the slide does not stop immediately and an overrun occurs. This overrun, similar to the breakthrough phenomenon, causes the upper and lower molds to be embedded more than necessary, reducing the durability of the mold, causing vibrations and
This causes noise, which can be prevented or reduced by the above device.

An example of a press equipped with this type of back pressure device is shown in FIGS. 1 and 2. In this press, a bolster 2 is provided so as to be freely drawn out forward from between the left and right uprights 1. A back pressure cylinder 3 and a bracket 4 of a back pressure device are arranged in the opening portion 1A of the left and right uprights 1. The bracket 4 is attached to both left and right sides of the slide 5 so that its lower surface is approximately at the same height as the lower surface of the slide 5, and is located above the back pressure cylinder 3. The back pressure cylinder 3 has its ram 3a
A predetermined stroke S upward from the height of the lower surface of the slide (indicated by the chain line in Figure 1) at the lower limit position.
It is supported by the upright 1 so that it can be raised and lowered. In its downward stroke, the slide 5 descends while pushing down the ram 3a by the distance S through the bracket 4 near the lower limit. As a result, back pressure acts on the slide 5,
Breakthrough phenomena are prevented.

Incidentally, the running direction of the bolster may be not only the front-rear direction as in the above example but also the left-right direction perpendicular thereto. In presses equipped with such bolsters, uprights are installed at the front and rear of the bolster so that the bolster can be pulled out from between them in the left and right directions. If a pressure cylinder is installed, this cylinder will get in the way of bolster driving.
In such presses, there are known examples in which a back pressure cylinder is suspended from the crown like a balance cylinder and installed between the slide and the back pressure is applied between the crown and the slide. However, this back pressure does not act on deformation of the upright, etc., so it is less effective in preventing breakthrough than when back pressure is applied between the slide and the bed.

This idea was made in view of the above-mentioned circumstances, and was designed to prevent the slide and the breakthrough phenomenon effectively in presses equipped with movable bolsters that run in the left and right directions without hindering the running of the bolsters. It is an object of the present invention to provide a back pressure device in which back pressure is applied between the bed and the bed.

Hereinafter, an embodiment of this invention will be described based on FIGS. 3 and 4.

FIG. 3 shows a part of the right side of the press, which is equipped with a movable bolster that runs in the left-right direction, when viewed from the front. That is, in FIG. 3, the left and right are the left and right directions of the press (indicated by arrow A),
The direction perpendicular to this is the front and back. Note that the device according to this invention has the same configuration on the left side of the press (not shown) as on the right side. In FIGS. 3 and 4, 11 shows the slide at the lower limit position of the slide stroke, 12 shows the movable bolster installed in the press, and 13 shows the bed. The bolster 12 has wheels 14 placed on a bolster rail (not shown) laid in the left-right direction, and a drive motor 15 and a transmission mechanism 16 for transmitting the rotation of the motor 15 to the wheels 14. It is equipped with By rotationally driving the motor 15, the wheels 14 are rotated, and the bolster 12, which is in the illustrated installation position, is pulled out from between the uprights 17 and 18 provided before and after the bolster 12.

A bracket 19 is attached to the side surface of the lower end of the slide 11.
is installed. Immediately below this bracket 19 there is a distance piece 20 and a back pressure cylinder 21. The back pressure cylinder 21 is a hydraulic cylinder, and when the ram 21a projects upward and the ram 21a is in the retracted position shown in FIG. It is installed perpendicularly to the bed 13 so that it is lower than the bed. Distance piece 20
is a round rod-shaped rod having approximately the same diameter as the ram 21a, and is fitted into the insertion hole 22 that vertically passes through the end of the bolster 12, and its upper and lower end surfaces are connected to the bracket 1.
9 and the ram 21a. Insertion hole 22
has an inner circumferential surface with a slightly larger diameter than the outer diameter of the distance piece 20, and a guide member 24 having a sliding guide bush 23 inside is fitted and fixed in the upper part, and a guide member 24 is fitted and fixed in the lower part. In order to prevent the stance piece 20 from falling off, an inward annular protrusion 2 is provided.
2a is formed. Distance piece 2
0 is formed with an outward annular protrusion 20a corresponding to the protrusion 22a, and a large diameter portion 20b is provided directly above the protrusion 20a. Another sliding guide bush 25 is fitted and fixed in this large diameter portion 20b. The distance piece 20 is movable up and down, and its large diameter portion 20b and bush 25 can move between the guide member 24 of the insertion hole 22 and the annular protrusion 22a. Then press the bolster 12
The insertion hole 22 is located directly above the back pressure cylinder 21 when the press is installed in the press. In this state, the ram 21 enters the insertion hole 22 and raises the distance piece 20.

When the slide 11 is lowered, the ram 21a is pushed down via the distance piece 20, thereby causing the slide 11 and the bed 13 to be pressed down, as in the case of the back pressure device shown in FIGS. 1 and 2. Back pressure is applied during this period, effectively preventing the breakthrough phenomenon. And bolster 1
When moving the ram 21a, by holding the ram 21a in the retracted position, the bolster 12 can pass above it without any trouble.

As explained above, according to this invention, there is no problem in running on the bolster, and back pressure acts between the slide and the bed, so that the breakthrough phenomenon can be effectively prevented.

[Brief description of the drawings]

1 and 2 show an example of a press equipped with a back pressure device, with FIG. 1 being a front view thereof and FIG. 2 being a side view thereof. 3 and 4 show an embodiment of this invention, with FIG. 3 being a perspective view showing the right side of the press, and FIG. 4 being a sectional view taken along the line -- in FIG. 11...Slide, 12...Movable bolster, 1
3...Betsudo, 20...Distance Peace,
21... Back pressure cylinder, 21a... Ram, 22...
...insertion hole.

Claims (1)

[Scope of utility model registration request] A back pressure cylinder 21 is provided upwardly below the slide 11 on both left and right sides of the bed 13, and a ram 21a of the back pressure cylinder 21 is retracted to a height lower than the upper surface of the bed 13, and When the bolster 12 is installed on the brace, it can enter an insertion hole 22 made in the bolster 12.
A back pressure device in a press equipped with a movable bolster for left and right running, into which a distance piece 20 protruding from the top surface is inserted so as to be able to rise and fall freely.