JPH10220425A - Clamp device for machining turntable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid applying a radial clamping force, and apply an enough clamping force only in a vertical direction. regarding a device of such a type as clamping a turntable via the application of a hydraulic brake force to a disc formed on a spindle having the turntable fixed. SOLUTION: A peripheral flange 30 is formed on a spindle having a turntable 1 fixed, and a collar type disc 31 is projected from the peripheral flange 30 along a radial direction. A ring 7 is inserted in an annular gap 6 formed out of the external surface of the peripheral flange 30, the internal surface of the peripheral flange housing circular recess of a base frame 5 and the disc 31, and fixed to the base frame 5. Also, a piston 9 is laid between the external surface of the body of the ring 7 and the internal surface of the base frame 5, so as to be vertically movable and come in contact with the outer end of the thin part 74 of the ring 7 at the edge in a travel direction. In addition, pressure oil feed passage 2 is formed on the base frame 5 for pressing the piston 9 toward the disc 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamping device for a rotary table for machining, and more particularly to a rotary table clamping device which applies hydraulic force to a disk formed on a spindle to which the rotary table is fixed. The present invention relates to an improvement in the clamping ability of a device of the type that performs clamping.

[0002]

2. Description of the Related Art First, an overall structure of a rotary table for machining to which the present invention is applied will be schematically described with reference to FIG. The spindle 3 is rotatably fitted into the center hole of the base frame 5 via a bearing, and its outer peripheral flange 30
Are concentrically accommodated in a circular concave portion formed on the upper surface of the base frame 5. The rotary table 1 is fixed on the outer peripheral flange 30. That is, the rotary table 1 and the spindle 3 are integrated with the base frame 5
Rotate about a vertical axis within. A clamp device CP is interposed inside the base frame.

As a clamp device as described above, there is a clamp device for a rotary table proposed in Japanese Utility Model Publication No. 8-8028, the main part of which is shown in FIG. A flange-shaped disk 31 is formed to protrude radially outward from the lower part of the outer peripheral flange 30 of the spindle 3 in the circular concave portion of the base frame 5. The lower surface of the outer edge of the turntable 1, the upper surface of the disk 31, the outer peripheral surface of the main body of the outer peripheral flange 30, and the inner peripheral surface of the circular recess of the base frame 5 define and define an annular space 6. , A ring 7 is inserted and fixed to the base frame 5.

[0004] Inside the ring 7, a lower thin portion 73 that can contact the disk 31, an inner thin portion 75 that can contact the outer peripheral surface of the outer peripheral flange 30, and an inner peripheral surface of the circular recess of the base frame 5. A hydraulic chamber 71 is defined and defined, and the hydraulic chamber 71 is connected to an appropriate pressure oil supply passage (not shown) formed in the base frame 5. The thin portions 73 and 75 are set to have a thickness such that when the pressure oil is inserted into the hydraulic chamber 71, the thin portions 73 and 75 are elastically deformed by the pressure. In addition, the space between the outer peripheral surface of the lower thin portion 73 of the ring 7 and the inner peripheral surface of the circular concave portion of the base frame 5 is sealed so that pressure oil does not leak.

When pressurized oil is inserted into the hydraulic chamber 71 of the ring 7, the pressure causes the lower thin portion 73 to bend downward, thereby holding the disk 31 of the spindle 3 in pressure contact with the base frame 5. And clamp the spindle so that it does not rotate. At the same time, the inner thin portion 75 bends inward and comes into pressure contact with the outer peripheral surface of the main body of the outer peripheral flange 30, and further clamps the spindle 3.

[0006]

However, this conventional clamping device has several problems. First the inner thin part 75
This is the point where the clamp is applied via If there is a manufacturing error in the related parts, the radial force acting on the spindle 3 at the time of clamping will not be uniform in each direction, so the spindle will be clamped in a deviated state shifted from the correct axis center position, As a result, a processing error occurs when processing the work on the rotary table.

Further, the clamp is applied via the lower thin portion 73. In this case, the force relationship between the hydraulic pressure in the hydraulic chamber 71 and the disk 31 of the spindle is just equal load (hydraulic). This corresponds to a state of being hung on a beam (disk 31). That is, since the force due to the hydraulic pressure is distributed over the entire radial direction of the disk 31, the deflection of the disk 31 corresponding to the beam is reduced, and the clamp is insufficient. As a result, the work of the spindle and hence the worktable on the rotary table moves during the machining, which also causes a machining error.
Further, in order to complete the sealing, the thickness of the sealing portion at the outer edge of the lower thin portion 75 must be increased. As a result, there is a problem that the deformation of the ring is small and a sufficient clamping force cannot be obtained.

In view of the circumstances of the prior art, an object of the present invention is to provide an apparatus of a type in which a rotating table is clamped by applying a braking force to a disk formed on a spindle to which the rotating table is fixed, in a vertical direction with respect to the disk. In other words, a sufficient clamp may be provided only by the clamp by pressing and holding the pressure.

[0009]

According to the present invention, there is provided a thin flange-shaped disk protruding radially outward from a spindle to which a rotary table is fixed, and a disk provided on a base frame and facing the disk. A clamping surface, a ring fixed to the base frame and projecting radially outward along a surface of the disk opposite to the surface facing the clamping surface, and a spindle at a position where the ring is sandwiched between the disks. A piston provided on the base frame so as to be movable along the axis, and when the pressurized oil is supplied, the piston presses the ring in the disk direction to press and clamp the disk between the ring and the clamp surface. In the clamping device of the type that clamps the rotary table, the piston is configured to press the end of the ring, and the area of the pressing surface is Is obtained by setting such that less than the pressure receiving area of the piston of the hydraulic fluid.

[0010]

When the piston is pushed toward the disk by the insertion of pressure oil and moves, the end face of the piston pushes the disk of the spindle through the outer edge of the thin portion of the ring. (Pressing force of the piston) is applied to the end of the cantilever (ring). That is, the force is concentrated only on the radial end of the ring,
The ring corresponding to the cantilever bends significantly. As a result, the ring presses the disk, and the deformed disk is strongly pressed and clamped by the ring and the clamp surface provided on the base frame, thereby increasing the number of clamps.

[0011]

FIG. 2 shows a first embodiment of a clamping device according to the present invention.
Is formed on the outer peripheral flange 30 for fixing the fixing member.
A thin flange-like disk 31 that is easily deformed is formed to protrude in the radial direction from a substantially central portion in the vertical direction of the outer peripheral flange 30. The disk 31 extends to a position facing the inner peripheral surface of the circular concave portion of the base frame 5.

An annular gap 6 is defined by the outer peripheral surface of the outer peripheral flange 30 main body, the inner peripheral surface and the bottom surface of the circular concave portion of the base frame 5 and the disk 31, and a ring 7 is inserted into the annular gap 6. And it is fixed to the base frame 5. A thin portion 74 protruding in the radial direction is fixed above the main body of the ring 7, and the thin portion 74 is configured to be able to make surface contact with the disk 31 of the spindle at least in part. A ring-shaped piston 9 having the spindle 3 as a central axis is interposed in a gap left between the outer peripheral surface of the ring 7 main body and the inner peripheral surface of the circular concave portion of the base frame 5 so as to be vertically movable. ing. This piston 9
The upper end face of the ring 7 has a stepped structure in the radial direction, that is, a projection 91 projecting from the outer edge of the upper end face.
Is set so as to contact only the outer edge of the thin portion 74. Here, the part where the piston presses the ring 7 is an end of the ring 7 and the area of the pressing surface is set to be smaller than the pressure receiving area of the piston from the pressurized oil. However, instead of forming the protrusion 91 on the piston 9 side, a downward protrusion may be formed on the outer edge of the thin portion 74 of the ring 7.

In the configuration of the ring 7, the main body and the thin portion 74 are formed as separate members and are integrally fixed by bolts for convenience in processing and function. It does not need to be formed of a material. For example, it is desirable that only the thin portion 74 be formed of a material having excellent spring properties and abrasion resistance.

The base frame 5 has a pressure oil supply passage 2 formed therein. The supply passage 2 opens into a cylinder chamber 51 located below the piston 9. In addition, in order to smoothly supply the first pressurized oil, as shown in FIG. 3, an exhaust passage 21 is formed in the base frame 5 so as to communicate with the cylinder chamber 51, and the outlet thereof is plugged (screw type). It is desirable to make it closed. At the time of pressurized oil supply, the plug 22 is removed to release the air in the pressurized oil supply passage 2, and after the first pressurized oil supply, the outlet of the exhaust passage 21 is closed again by the plug 22. I do.

When the pressure oil in the cylinder chamber 51 is inserted through the pressure oil supply passage 2 in the configuration shown in FIG. 2, the piston 9 is pushed upward by the pressure as shown in FIG. As a result, the deformed ring 7 clamps the spindle 3 by holding the disk 31 between the disk 31 and the base cover 52 fixed to the base frame 5. At this time, the pressing force of the piston 9 acts only on the outer edge of the thin portion 74 of the ring 7 only via the projection 91 on the outer edge of the upper end surface of the piston, so that the force relationship is concentrated only on the end of the cantilever. This corresponds to a state where a load is applied, and the thin portion 74 of the ring 7 corresponding to the cantilever and the disk 31 are largely bent. As a result, the clamping force is also sufficient. When the supply of the pressure oil is stopped and the pressure in the cylinder chamber 51 decreases, the thin portion 74 of the ring and the disk 31 return to their original states by their own spring properties, and the piston 9 also returns to the spring state of the thin portion 74 of the ring. It is returned to the original position by the restoration by sex. Therefore, the press-clamp state of the disk 31 is released, and the disk 31 enters the non-clamp state.

FIG. 4 shows a second embodiment of the present invention, in which the overall structure is substantially the same as that of the embodiment shown in FIG. 2 is different from that of FIG. 2 in that the main body and the thin portion 74 have an integral structure. Further, not only the piston 9 but also the thin portion 74 of the ring 7 has an upwardly projecting portion at the outer edge thereof, and comes into contact with the disk 31 via this projecting portion. Also in this case, the contact structure between the piston 9 and the thin portion 74 of the ring 7 can be reversed.

FIG. 5 shows a third embodiment of the clamping device according to the present invention, wherein an outer peripheral flange 30 for fixing the rotary table 1 is formed on the spindle 3. A thin and easily deformable flange-shaped disk 31 is formed to protrude outward in the radial direction from near the lower portion of the outer peripheral flange 30. The disk 31 extends to a position facing the inner peripheral surface of the circular concave portion of the base frame 5.

An annular gap 6 is defined by the outer peripheral surface of the outer peripheral flange 30 main body, the inner peripheral surface of the circular concave portion of the base frame 5, the lower surface of the turntable 1, and the disk 31. The base cover 52 fixed to the upper surface of the frame 5 is inserted, and the ring 7 is fixed to the lower part inside the base cover 52. A thin portion 74 is formed to protrude from the lower portion of the main body of the ring 7 in the radial direction, and the thin portion 74 is configured to be in surface contact with the spindle disk 31 at the outer edge.

A piston 9 is vertically movably mounted on a base cover 52 which forms a part of the base frame 5. The lower end surface of the piston 9 has a stepped structure in the radial direction, and the convex portion 93 projecting from the outer edge of the lower end surface is set so as to contact only the outer edge of the thin portion 74 of the ring 7. Have been. Also in this case, the contact structure between the two can be reversed.

The base frame 5 has a pressure oil supply passage 2 formed therein, and the supply passage 2 opens into a cylinder chamber 51 facing the upper end surface of the piston 9. As in the case of the embodiment shown in FIG. 2, it is desirable to connect an appropriate exhaust path to the pressure oil supply path.

When the pressure oil is inserted through the pressure oil feed passage 2 in the configuration shown in FIG. 5, the piston 9 is pushed downward by the pressure and presses the outer edge of the thin portion 74 of the ring 7, and as a result, The deformed ring 7 clamps the spindle 3 by holding the disk 31 between the base frame 5 and the disk 31. At this time, since the pressing force of the piston 9 acts only on the outer edge of the thin portion 74, the force relationship corresponds to a state where concentrated load is applied only to the end of the cantilever, and the thin portion corresponding to the cantilever 74 and the disk 31 bend significantly. As a result, the clamping force is also sufficient.

[0022]

According to the present invention, only the vertical clamp acts on the spindle by the movement of the piston, and no radial force is applied to the spindle during this clamp. Therefore, there is no uneven clamping due to the displacement of the spindle, and the processing error is reduced accordingly.

Further, since the piston presses the disk of the spindle through the thin portion of the ring in such a manner that a concentrated load is applied only to the end of the cantilever, the disk bends accordingly and the sufficient clamping force can be obtained. Will be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view showing an overall configuration of a processing turntable provided with a clamping device of the present invention.

FIG. 2 is a sectional side view showing a first embodiment of the clamp device of the present invention.

FIG. 3 is a sectional side view showing an example of the pressure oil supply mechanism.

FIG. 4 is a sectional side view showing a second embodiment of the clamp device of the present invention.

FIG. 5 is a sectional side view showing a third embodiment of the clamp device of the present invention.

FIG. 6 is a sectional side view showing a configuration of a conventional clamping device.

[Explanation of symbols]

 1: Rotary table 2: Pressurized oil supply path 22: Plug 3: Spindle 30: Outer peripheral flange 31: Disk 5: Base frame 7: Ring 74: Thin portion 76: Thin portion 9: Piston

Claims (3)

[Claims] A thin flange-shaped disk protruding radially outward from a spindle to which a rotary table is fixed; a clamp surface provided on a base frame facing the disk; and a clamp surface fixed to the base frame. A ring protruding radially outward along the surface of the disk opposite to the side facing the clamping surface of the disk, and the base frame movably along the spindle axis at a position where the ring is sandwiched between the disks. Provided with a piston, wherein when the pressurized oil is supplied, the piston presses the ring in the disk direction and clamps the disk by pressing the disk between the ring and the clamp surface, thereby clamping the rotary table, The piston is configured to press the end of the ring, and the area of the pressing surface is smaller than the pressure receiving area of the piston from pressurized oil. Clamping device for machining rotating table to. 2. The clamp device according to claim 1, wherein a convex portion is provided on at least one side of the piston and the ring, and the convex surface is a pressing surface of each other. 3. The clamping device according to claim 1, wherein the main body and the thin portion of the ring are formed separately from each other and removably attached to each other.