JPH08294835A - Clamp device of index table - Google Patents

Abstract

PURPOSE: To provide an index table by which large clamp force can be obtained under small fluid pressure by arranging a swelling pressure body of shape memory allay so as to extremely contact with a clamp face plate. CONSTITUTION: In an index table 1, its turning body 2 is rotatably supported so as to be indexed by a prescribed quantity, and a clamp face plate 5 of the index table 1 is pressed by a pressing surface of a swelling pressure body 23 swollen and deformed by fluid pressure P through a pressing clamp member 20 provided on the fixing side. The swelling pressure body 23 of shape memory allay is arranged so as to extremely contact with the clamp face plate 5 of the index table 1 by recessing a central surface part of a pressing surface 23A when the fluid pressure P is not applied. In a clamp device 10, this pressing surface is strongly brought into pressure contact with and fixed to the clamp face plate since elastic projecting force possessed by itself is added when the pressing surface 23A is swollen and deformed on the clamp face plate 5 by high temperature fluid pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device for an index table of a machine tool, and more particularly to a clamp mechanism improved to obtain a strong gripping force with a simple structure.

[0002]

2. Description of the Related Art Conventionally, a clamp device for an index table that supports a pallet of a machine tool has a revolving body of the index table rotatably fitted to a support shaft portion. The index table is swung to an arbitrary indexing angle by a swivel driving member, and at a predetermined position of the index table, a clamp face plate of the index table is pressed and held by a pressing clamp member provided on the fixed side of the support shaft portion. is there. As shown in FIGS. 7 and 8, this pressing type clamp member is a pressing type in which a bulging pressure body 110 having a pressing surface 100 that bulges and deforms with a fluid pressure P is firmly pressed into contact with a clamp face plate 120 of an index table. It has a structure of the clamp member 200.

[0003]

However, according to the pressing clamp member 200, a large gap X is formed between the pressing surface 100 and the clamp face plate 120 in the unclamping state of FIG. Here, the bulging pressure body 110 that presses and grips the clamp face plate 120 of the index table by bulging and deforming with the fluid pressure P is deformed such that the bulging deformation is bulging like a belly belly as shown in FIG. Will be forced to. In this case, the total pressure of the fluid pressure P acting on the clamp face plate 120 of the index table does not function effectively, and most of it is spent on the energy for bulging and deforming the bulging pressure body 110, so that a large clamping force is obtained. Absent. Furthermore, since there is a large gap X between the pressing surface 100 and the clamp face plate 120, the stroke from unclamping to clamping is long, and the durability and centering accuracy of the bulging pressure body 110 are poor.

SUMMARY OF THE INVENTION In view of the problems of the conventional index table clamping device, an object of the present invention is to provide a clamping device that can obtain a large clamping force with a small fluid pressure.

[0005]

In order to achieve the above object, the present invention provides a pressure clamp member according to claim 1, wherein the index table is supported so as to rotatably and predeterminedly index the revolving structure and is provided on the fixed side. Thus, in the index table clamping device in which the clamp face plate of the index table is pressed by the pressing surface of the bulging pressure body that bulges and deforms by fluid pressure, the bulging pressure body is made of a shape memory alloy and If not, dent the central surface of the pressing surface and place it in contact with the clamp face plate of the index table so that when the pressing face bulges and deforms to the clamp face plate due to high-temperature fluid pressure, the elastic protrusion output of this pressing face adds The index table clamping device is characterized in that it is strongly pressed and fixed to the clamp face plate.

[0006]

According to the index table clamp device of the present invention, the bulging pressure body that controls the clamp is separated from the clamp face plate of the index table by denting the central surface portion of the pressing surface when unclamping without high temperature fluid pressure. Therefore, the index table can be freely rotated. Then, when the pressing surface bulges and deforms to the clamp face plate due to the high temperature fluid pressure, the elastic protrusion output of the pressing face is added, and the pressing face is firmly and quickly pressed and fixed to the clamp face plate. As a result, a large clamping force can be obtained even with a small fluid pressure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below. FIG. 1 is a vertical cross-sectional view showing an entire clamp device for an index table of a machine tool according to the present invention, and FIG. 2 is a cross-sectional view of a main part according to the present invention.

1 and 2 show a clamp device 10 for an index table. The index table 1 is supported by a bearing 4 of a table body 3 so that a revolving structure 2 arranged at the center of the revolving structure can be rotatably and predetermined indexed. Has been done. A fixed work carrier such as a pallet P is detachably mounted on the index table 1. A clamp device 10 is provided between the lower surface of the index table 1 and the table body 3. In this clamp device 10, a clamp face plate 5 (a ring-shaped face plate) attached to the lower surface of the index table 1 is made to face a pressure receiving surface 3A recessed in the outer periphery of the upper surface of the table body 3 under a narrow gap X. A press clamp member 20 for pressing and holding the clamp face plate 5 is provided on the upper surface middle abdomen of the table body 3 on the fixed side. The pressing clamp member 20 includes a cantilever block body 21 and a bulging pressure body 23 of a shape memory alloy attached to the lower surface 22, and the pressing surface of the bulging pressure body 23 by the high temperature fluid pressure P from the passage A. By bulging and deforming 23A, the clamp face plate 5 of the index table 1 is pressed by the pressing face 23A of the bulging pressure body.

When the fluid pressure P at high temperature is absent, the bulging pressure body 23 is depressed in the central surface portion of the pressing surface 23A so as to be disposed in the clamp face plate 5 of the index table 1 with a gap X1 and is pressed by the fluid pressure P. When the surface 23A is bulged and deformed to the clamp face plate 5, the pressing face is configured to add its own elastic projection output to strongly press and fix the clamp face plate. The bulging pressure body 23 and the clamp face plate 5 are arranged on one side as shown in FIGS. 3 and 4, and the bulging pressure body 23 is placed above and below the clamp face plate 5 as shown in FIGS. It is prepared in a pair and arranged on both sides.

The clamp device 10 for the index table 1 according to the present invention is constructed as described above and operates as follows. First, in FIGS. 3 and 4, the bulging pressure body 23, which controls the clamp, is depressed at the center surface portion of the pressing surface 23A during unclamping without the high-temperature fluid pressure P so that the gap X1 extends from the clamp surface plate 5 of the index table 1. They are apart in contact with each other. In this state, the index table 1 can freely rotate. When the pressing surface 23A is bulged and deformed to the upper surface of the clamp face plate 5 by the high temperature fluid pressure P, the pressing face 23A adds its own elastic projection output to firmly and quickly press and fix it to one side of the clamp face plate 5. To do.
At this time, the clamp face plate 5 bends slightly downward and also abuts against the pressure receiving face 3A of the table body 3 and presses the pressing face 23.
Press and grip with A in a sandwich shape. Thus, a strong clamping force K can be obtained with a small fluid pressure P.

5 and 6, the pair of upper and lower bulging pressure bodies 23, 23, which control the clamp, dent the central surface portions of the pressing surfaces 23A, 23A at the time of unclamping without the fluid pressure P, and thus the index table 1 The clamp face plates 5 are separated from each other by being in contact with the gap X1. In this state, the index table 1 can freely rotate. When the pressing surfaces 23A, 23A are bulged and deformed to the upper and lower surfaces of the clamp face plate 5 by the high-temperature fluid pressure P, the pressing surfaces 2
3A and 23A add their own elastic protrusion outputs to firmly and quickly press and fix them to both sides of the clamp face plate 5. At this time, the clamp face plate 5 is crimped and gripped from above and below in a sandwich shape. Therefore, a large clamping force K, K can be obtained with a small fluid pressure P.

The present invention is not limited to the above-mentioned embodiment, but the design of the essential structure can be changed. For example, the bulging pressure body of the shape memory alloy may be made of bimetal, or the number of sets of the clamp devices 10 arranged around the index table 1 may be changed and set to an appropriate number.

[0013]

According to the present invention, the bulging pressure body of the shape memory alloy is recessed in the central surface portion of the pressing surface when there is no fluid pressure so as to be disposed so as to be in close contact with the clamp face plate of the index table, and the pressing face is pressed by the fluid pressure at high temperature. When bulging and deforming to the clamp face plate, this pressing face adds its own elastic projection output and strongly presses and fixes to the clamp face plate, so the bulging pressure body that controls the clamp is the center of the pressing face when unclamping without fluid pressure. The surface of the index table is recessed to separate it from the clamp face plate of the index table, and the index table can freely rotate.When the pressing face bulges and deforms to the clamp face plate due to high-temperature fluid pressure, this pressing face has its own elastic projection output. Is added to firmly and quickly press-bond to the clamp face plate, and a large clamping force can be obtained with a small fluid pressure.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing a clamp device for an index table according to the present invention.

FIG. 2 is an enlarged sectional view of a main part according to the present invention.

FIG. 3 is a sectional view of an essential part of the first embodiment according to the present invention.

FIG. 4 is a cross-sectional view showing the operation of the first embodiment according to the present invention.

FIG. 5 is a sectional view of an essential part of a second embodiment according to the present invention.

FIG. 6 is a sectional view showing the operation of the second embodiment according to the present invention.

FIG. 7 is a cross-sectional view of a main part according to a conventional example.

FIG. 8 is a sectional view showing an operation according to a conventional example.

[Explanation of symbols]

 1 Index table 2 Revolving body 3 Table body 3A Pressure receiving surface 5 Clamping face plate P Fluid pressure 10 Clamping device 20 Pressing clamp member 21 Block body 22 Bottom surface 23 Shape memory alloy bulging pressure body 23A Pressing surface K Clamping force

Claims (1)

[Claims] 1. A swelling pressure body for swelling and deforming a clamp face plate of the index table by a fluid pressure by a pressing clamp member supported on the index table so as to rotatably and predeterminedly index the revolving body and provided on the fixed side. In an index table clamping device that presses by a pressing surface, the bulging pressure body is made of a shape memory alloy, and when there is no high temperature fluid pressure, the central surface portion of the pressing surface is dented and arranged in a pole contact with the clamping surface plate of the index table. When the pressing surface is bulged and deformed by the high temperature fluid pressure to the clamp surface plate, the pressing surface is added with its own elastic projection output to strongly press and fix to the clamp surface plate.