JPS5920914Y2 - Machine tool hydraulic clamper_drive device - Google Patents

Description

[Detailed explanation of the invention] This invention is suitable for machine tools (metal processing machines, cutting machines, etc.)
Among devices that drive a hydraulic clamper that fixes tools, etc. (tools or workpieces), this type uses a booster to increase the pressure of the pressure fluid (gas or liquid) from the fluid pressure source to drive the clamp cylinder of the hydraulic clamper. relating to things.

In this type of device, when the pressure of the fluid pressure source disappears, the pressure fluid flows backward, the clamper becomes unclamped, and the tools fall off, causing damage to the tools and machinery.

In order to solve this problem, the present invention prevents the pressure fluid from flowing back even if the pressure of the fluid pressure source disappears, and also allows the pressure fluid to flow back without any problem during the unclamping operation.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a compressor, and the air pressure in its pressure accumulator tank 2 (fluid pressure source) is increased by a booster 3, and the clamp cylinder 5 of the hydraulic clamper 4 is operated in accordance with the switching of the directional control valve 6. The upper and lower mold mounting dies 8 are fixed or unfixed to the mechanical press 7 using a hydraulic clamper by telescopic operation.

That is, a clamp side chamber 10 and an unclamp side chamber 11 of the input chamber 9 of the booster 3 are connected to the pressure accumulator tank 2 via the directional switching valve 6 and the low pressure clamp flow path 12 and the low pressure unclamp flow path 13, respectively. .

A clamp cylinder 5 of a hydraulic clamper 4 is connected to an output chamber 14 of the booster 3 through a high pressure oil passage 15 .

The output chamber 14 is automatically supplied with hydraulic oil from an oil storage tank 16.

As a result, when the directional control valve 6 is set at the clamp position by the spring 17, pressurized air is forced into the clamp side chamber 10, the cylinder 5 is expanded, and the clamper 4 is placed in the clamp position.

When the directional control valve 6 is manually operated to the unclamping position, pressurized air is forced into the unclamping side chamber 11,
The cylinder 5 contracts and the clamper 4 becomes unclamped.

When the pressure in the pressure accumulator tank 2 decreases or disappears, the directional control valve 6 is moved to the clamp position by the spring 17,
Despite this, pressurized air and oil flow back,
The clamper 4 becomes unclamped and the die 8 falls off.

To prevent this, check valve 18 prevents the backflow.
A return valve 19 that allows the reverse flow is interposed in the high pressure oil passage 15.

That is, the check valve 18 is turned on by the spring 20 with respect to the high pressure oil passage 15, and the return valve 19 is turned on to the offset valve 1.

Further, the check valve 18 is turned off and one return valve is turned on by the pilot pressure in the pilot passage 21 communicated and led out from the unclamping side chamber 11.

As a result, when the directional control valve 6 is ON-set by the spring 17, there is no pilot pressure in the pilot passage 21, the check valve 18 is turned ON by the spring 20, and the return valve 1
9 is offset, and by the check action of the check valve 18, oil can be supplied to the cylinder 5, but the oil is prevented from being drained, and the clamper 4 is fixed in a clamped state.

Therefore, even if there is no pressure in the pressure storage tank 2, the clamper 4 continues to clamp correctly.

Furthermore, when the directional control valve 6 is manually operated to the unclamp position, the pressure from the pyrower 1 in the pilot passage 21 increases and overcomes the spring 20, turning off the check valve 18 and turning on the return valve 19. As a result, the air pressure in the unclamping chamber 11 causes the hydraulic oil to flow back without any problem, causing the cylinder 5 to contract, and the clamper 4 to be switched to the unclamping state.

As a modification of the above embodiment, it is possible to change a part of it as shown in the following items.

(4) As shown in FIG. 2, check valve 18 and return valve 19
is interposed in the low pressure clamp flow path 12.

(B) As shown in FIG. 3, the check valve 18 and the return valve 19 are constructed integrally with the directional switching valve 6.

That is, the check valve 18 is interposed in the press-in passage 23 of the clamp side part 22 of the directional switching valve 6, and the discharge passage of the unclamp side part 24 also serves as a return valve 19.

(C) In B above, the check valve 18 is relocated to the pressure feed channel 25 that connects the pressure accumulation tank 2 and the directional switching valve 6.

(D) As shown in FIG. 4, the return valve 19 has a structure that releases the check action of the reverse IL valve 18.

The circuit diagram of both valves 18 and 19 in this case is as shown in FIG.

(E) As shown in FIG. 6, the check valve 18 and the return valve 1
9 are formed separately and connected in parallel.

(F) A hydraulic pump is used as a fluid pressure source instead of the pressure storage tank 2 of the compressor 1.

Since the present invention is constructed and operates as described above, as long as the directional valve is in the clamp position, the return valve is turned off;
Since the check valve acts as a check, even if the pressure of the fluid pressure source decreases or disappears, the clamp cylinder remains blocked and the clamper continues to be fixed in the clamped state, preventing the clamped tools, etc. Falling accidents can be eliminated.

Furthermore, since the return valve is turned on when the directional control valve is operated to the unclamped position, the clamp cylinder can be contracted and the clamper can be brought into the unclamped state without any problem.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a pneumatic/hydraulic circuit diagram, FIGS. 2 and 3 are variations of FIG. 1, and FIG. 4 is a vertical cross-section of a check valve and a return valve. FIG. 5 is a top view, FIG. 5 is a circuit diagram of FIG. 4, and FIG. 6 is a modification of the combination of a check valve and a return valve. 2... Fluid pressure source, 3... Booster, 4.
... Hydraulic clamper, 5 ... Clamp cylinder, 6 ... Directional switching valve, 9 ... Input chamber, 12 ... Low pressure clamp flow path , 14...
...Output chamber, 18...Check valve, 19...
...Return valve.

Claims (1)

[Claims for Utility Model Registration] 1. The input chamber 9 of the booster 3 is connected to the fluid pressure source 2 via the directional control valve 6, and the clamp cylinder 5 of the hydraulic clamper 4 is connected to the output chamber 14 of the booster 3. , a check valve 18 that prevents backflow from the cylinder 5 to the fluid pressure source 2 via the booster 3, and a return valve 19 that allows the backflow from the fluid pressure source 2 to the booster 3.
The return valve 19 is placed in the pressure flow path leading to the cylinder 5 through the cylinder 5, and the return valve 19 is switchable between an on position and an off position. A hydraulic clamper drive device for a machine tool configured to switch to the on position when the clamper is in the unclamping position. 2 Utility Model Registration Scope In the hydraulic clamper drive device according to claim 1, the check valve 18 and the return valve 19 are interposed in the high pressure oil passage 15 that connects the output chamber 14 of the booster 3 and the cylinder 5. thing. 3 Utility Model Registration Scope of Claims In the hydraulic clamper drive device according to claim 1, the check valve 18 and the return valve 19 are connected to the low pressure clamp flow path 12 that connects the input chamber 9 of the booster 3 and the directional control valve 6. something that was mediated. 4 Utility Model Registration Scope of Claims The hydraulic clamper drive device according to claim 1, in which the check valve 18 and the return valve 19 are integrated with the directional switching valve 6.