JPH075960Y2 - Clamp device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a clamp device for a workpiece to be machined by a machine tool or the like.

[Conventional technology]

Conventionally, a machine tool having a turntable is provided with a clamp device for fixing a work on the turntable.

In the clamp device, as shown in FIG. 3, for example, a clamp cylinder c is provided between one end side of a clamp arm a having an intermediate portion supported and a turntable b, and one end of the clamp arm a is provided by the clamp cylinder c. By pushing up, the work d can be fixed between the other end of the clamp arm a and the turntable b, and between the clamp cylinder c and the hydraulic pressure source e via an accumulator f or a non-leak valve. By connecting, the clamping force does not decrease even if the hydraulic pressure source e is disconnected after clamping.

Further, the clamp device shown in FIG. 4 is provided with a pressure spring g such as a disc spring that generates a clamping force on the upper part of the clamp cylinder c. The work d is clamped by the spring force of the compression spring g and the clamp cylinder c is moved to the clamp cylinder c. The workpiece d is unclamped by supplying hydraulic pressure, and the clamp cylinder c is configured as shown in FIG.

[Problems to be solved by the device]

However, in the former case in which the accumulator f and the non-leak valve are provided between the clamp cylinder c and the hydraulic pressure source e, when the hydraulic pressure in the clamp cylinder c leaks or the hydraulic pipe is damaged, the clamping force of the work d is increased. There is a risk that the work d may fall and separate from the turntable b during processing.

In addition, although the latter one using the compression spring g does not have the above danger, since the stroke of the compression spring g is short, it cannot be clamped when the size of the work d is changed, and the versatility is low. There were problems such as high price with the clamp device.

The present invention has been made for the purpose of improving the above-mentioned problems, and an object thereof is to provide a clamp device having a simple structure, which is inexpensive and does not cause the work to come off during machining.

[Means and Actions for Solving the Problems]

In order to achieve the above-mentioned object, the present invention provides a clamp device which is provided with a clamp arm swingable by a clamp cylinder on a turntable, and clamps a work piece placed on the turntable at the tip of the clamp arm. An elastic body made of urethane rubber for urging the clamp arm upward is provided on the outer peripheral portion of the piston rod protruding upward from the clamp cylinder. The elastic body is detachably provided outside the clamp cylinder. Therefore, when elastic bodies having different heights are selected according to the work, they can be easily replaced, and the elastic bodies are not deteriorated early by the oil supplied to the clamp cylinder.

〔Example〕

The present invention will be described in detail with reference to one embodiment shown in the drawings. In the drawing, reference numeral 1 is a clamp body provided on a turntable 2 of a machine tool, and an intermediate portion is provided on a support rod 3 protruding from the turntable 2. Has a clamp arm 4 supported thereon, and the tip end of the piston rod 5b of the clamp cylinder 5 is screwed to one end of the clamp arm 4.

The bottom side of the clamp cylinder 5 is the turntable 2
A quick coupler 7, which is fixed on a mount 6 provided above and is detachable in the rod-side chamber 5c in the cylinder 5a, is connected to a hydraulic power source 9 via a pipe line 8 provided midway.

An elastic body 10 made of urethane rubber is interposed between the upper surface of the cylinder 5a and the lower surface of the clamp arm 4.

The elastic body 10 is a cylindrical body having substantially the same diameter as that of the cylinder 5a, is fitted and inserted into the piston rod 5b, and a plurality of different heights are prepared in advance, and the height differs depending on the work 11. By selecting one, an arbitrary stroke can be obtained.

Next, the operation will be described. When clamping the workpiece 11 to be processed on the turntable 2, first, the hydraulic pressure is supplied from the hydraulic pressure source 9 to the rod side chamber 5c of the clamp cylinder 5,
Push down one end of the clamp arm 4 against the elastic body 10,
The work 11 is positioned between the other end of the clamp arm 4 and the upper surface of the turntable 2.

Next, when the hydraulic pressure in the rod side chamber 5c of the clamp cylinder 5 is released in this state, the other end of the clamp arm 4 is pushed down by the restoring force of the elastic body 10, and the work 11 is fixed on the turntable 2 by the clamp arm 4. Therefore, by disconnecting the quick coupler 7 thereafter, the worktable 11 can be processed by rotating the turntable 2.

[Effect of device]

As described in detail above, this invention uses the elastic force made of urethane rubber or the like to generate the clamping force when clamping the workpiece with the clamp arm. Compared to the one that generates force, the clamping force does not decrease during machining due to the leak of the clamp cylinder or the failure of the hydraulic piping, and the work can be completely machined.

In addition, since the elastic body is detachably installed on the outside of the clamp cylinder, it is easy to replace the elastic body with different height depending on the size of the workpiece to be clamped, and the elastic body is supplied to the clamp cylinder. Since the elastic body is not deteriorated early by the oil contained in the elastic body, a good clamping force can be obtained for a long period of time.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is an overall side view, FIG. 2 is an enlarged sectional view of a clamp cylinder, and FIGS. 3 to 5 are conventional explanatory views. 2 is a turntable, 4 is a clamp arm, 5 is a clamp cylinder, 10 is an elastic body, and 11 is a work.

Claims (1)

[Scope of utility model registration request] 1. A turntable 2 is provided with a clamp arm 4 swingable by a clamp cylinder 5 composed of a hydraulic cylinder, and a tip of the clamp arm 4 clamps a work 11 placed on the turntable 2. In the clamp device, an elastic body 10 made of urethane rubber for urging the clamp arm 4 upward is detachably provided on the outer peripheral portion of the piston rod 5b protruding upward from the clamp cylinder 5.