JPS6363534A - Press impact noise absorber for press machine - Google Patents

Abstract

PURPOSE:To restrain the generation of the impact noise of the case of an upper die coming into contact with a material initially by actuating a servo valve at the position just before the upper die abutting to a material and feeding the press oil for an accumulator to the upper part oil chamber of a cushion cylinder via the servo valve. CONSTITUTION:A limit switch 21 detects it just before the upper die 19 coming into contact with a material 20 with its descent at the time of a press work. The servo valve 10 is actuated via a control device 22 with this detection signal and the press oil is fed to the upper oil chamber 6 of a cushion cylinder 1 in a short time from an oil accumulator 13. A cushion pad 2 is then pushed down by compressing a lower cushion chamber 4 and the sealed gaseous body of a gaseous body cushion tank 5. The generation of the impact noise at the clamping time of the material 20 by the upper die 19 and lower die outer 24 can almost be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 11 The present invention relates to a press impact sound damping device for a press machine.

[Prior Art] Fig. 2 shows an example of a conventional press machine, in which a lower mold C is provided on a bolster plate b provided on a bed a, and a lower mold C is provided on a bolster plate b provided on a bed a. A pin f having a lower mold outer e for receiving a material d is provided, a pin plate g provided at the lower end of the pin f is supported on a die cushion h, and during pressing, the upper mold i is First, the material d is pressed against the lower mold outer e to clamp the material d, and then lowered in the clamped state, the material d is formed by the upper and lower molds i and c. is now being carried out.

The figure shows a soundproof wall installed to cover the press equipment!
indicates an opening/closing W provided on the soundproof wall k for taking in and out the mold when replacing the mold.

[Problems to be solved by the invention] However, in the above-mentioned press machine, when the upper mold j first hits the material d (when the material is clamped by the upper mold and lower mold outer), an emergency occurs. This is causing a problem as it makes a loud impact sound (metallic sound).

For this reason, in the past, a heavy soundproof wall k was installed, and at this time, an opening/closing door was installed on the soundproof wall k for exchanging molds, etc. However, despite having a very large and expensive structure, it has not been very effective in soundproofing.

The present invention was made by focusing on the above-mentioned conventional problems.
The purpose is to suppress the impact noise generated when the upper mold first contacts the material.

[Means for solving the problems] The present invention attempts to solve the above technical problems, and
In a press machine that has a die cushion that maintains the clamped state of the material by the upper and lower molds by a cushion cylinder that has a piston connected to a cushion pad and forms a lower cushion chamber and an upper oil chamber, pressurized oil of an oil accumulator is used. is supplied to the upper oil chamber of the cushion cylinder via a servo valve, and a position detector is provided to detect the position just before the upper mold contacts the material, and the upper oil is supplied to the upper oil chamber via a servo valve. This invention relates to a press impact sound damping device for a press machine, characterized in that a control device is provided that operates the servo valve to immediately supply pressurized oil to the chamber to push down the cushion pad.

[Function] Therefore, in the present invention, the pressure oil of the accumulator is transferred to the cushion cylinder so that the position just before the upper mold first contacts the material is detected, and the detection signal immediately operates the servo valve to lower the cushion pad. Since the oil is supplied to the upper oil chamber of the upper mold, the lowering speed of the upper mold and the lowering speed of the cushion pad at the time of contact can be made substantially equal to each other, thereby preventing the generation of impact noise.

[Implementation example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the present invention. In the figure, 1 is a cushion cylinder. Inside the cushion cylinder l, there is provided a piston 3 connected to an upper cushion pad 2, and in a lower cushion chamber 4. is filled with gas from the gas cushion tank 5.

Further, oil from an oil tank 7 is supplied to the upper oil chamber 6 of the cushion cylinder 1 via a pump 8, a check valve 9, and a servo valve 10.

Further, an oil accumulator 13 is provided between the check valve 9 and the servo valve IO, and a relief valve 14 and a switching valve 15 are provided between the pump 8 and the check valve 9. An unload circuit is provided to return the oil to the oil tank 7.

Further, the oil chamber 6 and the oil tank 7 are connected by a circuit including a check valve 16, a switching valve 17, and a throttle valve II in parallel. 18 is a charging hose connected to the gas cushion tank 5.

In the configuration described in item 1, a position detector 21 such as a limit switch is provided to detect the position immediately before the upper mold 19 contacts the material 20, and a signal from the position detector 21 is transmitted to the control device 2.
2 to perform switching control of the servo valve 10. In the figure, 23 indicates a lower mold, and 24 indicates a lower mold outer.

In the above configuration, the lower cushion chamber 4 of the cushion cylinder 1 is filled with compressed gas from the gas cushion tank 5, and the changeover valve 17 is switched to the A side so that the oil chamber 6
is in communication with the oil tank 7, so the piston 3 is located at the upper limit.

During press work, when the upper mold 19 descends, the material 20
The limit switch 21 detects it just before it comes into contact with
Based on the detection signal, the servo valve 10 is
is activated, the pressure oil in the oil accumulator 13 is supplied to the upper oil chamber 6 of the cushion cylinder 1 in a short time (at this time, the switching valve] 7 is in position B), and the lower cushion chamber 4 of the cushion cylinder 1 and the gas cushion are The gas enclosed in the tank 5 is compressed to push down the cushion pad 2.

-6= At this time, the amount of oil supplied is controlled by the servo valve 10 so that the descending speed of the upper mold 19 when it comes into contact with the material 20 and the descending speed of the cushion pad 2 are approximately equal. do. Thereby, it is possible to almost prevent the occurrence of impact noise when the material is clamped by the mold 19 and the lower mold outer 24.

After the material 20 is clamped, the cushion pad 2 and the piston 3 are pushed down by the pressing force of the press, but at this time, the oil in the oil tank 7 is sucked into the upper oil chamber 6 through the check valve 16 and is lowered to the lower limit of the stroke. During this time, the material 20 is molded by the mold 19° 23.

When the stopper mold 19 is raised, the cushion pad 2 is pushed up by the gas pressure in the lower cushion chamber 4 of the cushion cylinder 1, and at the same time, the oil in the upper oil chamber 6 flows into the switching valve 17 A.
Through the throttle valve 11, the throttle is adjusted and the oil is drained into the oil tank 7.

The used oil in the oil accumulator 13 is replenished by the pump 8 until the next cycle, and after being replenished, it is unloaded by the relief valve 14 and the switching valve 15 and returned to the oil tank 7.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and that the detection method and detection position of the position detector can be changed in various ways, that various gases can be used as the cushioning gas, and that various modifications can be made. It goes without saying that the present invention can be applied to a die cushion of a press machine, and that various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As described above, the press impact sound damping device of the press machine of the present invention operates so that when the upper die comes into contact with the material, the cushion pad is lowered and brought into gentle contact. Therefore, the generation of impact noise at the time of contact can be significantly reduced, and the structure of the soundproof wall can be significantly simplified or omitted, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing an example of a conventional press machine. 1 is a cushion cylinder, 2 is a cushion pad, 3 is a piston, 4 is a lower cushion chamber, 5 is a gas cushion tank, 6 is an upper oil chamber, 7 is an oil tank, 8 is a pump, 1
0 is a servo valve, 13 is an oil accumulator, 16 is a check valve, 17 is a switching valve, 19 is an upper mold, 20 is a material, 21
2 is a position detector, 22 is a control device, and 23 is a lower mold.

Claims (1)

[Claims] 1) In a press machine having a die cushion, the material is kept clamped by the upper and lower molds by a cushion cylinder having a piston connected to a cushion pad and forming a lower cushion chamber and an upper oil chamber,
The pressure oil of the oil accumulator is configured to be supplied to the upper oil chamber of the cushion cylinder via a servo valve, and a position detector is provided to detect the position just before the upper mold contacts the material, and A press impact sound damping device for a press machine, characterized in that a control device is provided that operates the servo valve to immediately supply pressurized oil to the upper oil chamber in response to a signal to push down the cushion pad.