JPS6122749Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positioning device for pallets placed on a table of a machine tool.

There are various main stages for positioning and fixing the workpiece on the machine tool table, but the conventional ones are
Since the workpiece was placed directly on the table, it was common to hold the workpiece down from the outside using a yaw or jig.

However, automation in machine shops in recent years has finally reached automatic transport of workpieces. In such automatic transport of workpieces, the workpieces are fixed in fixed positions on pallets, and the workpieces are transported on this pallet. At the same time, the workpiece is fixed to the table via the pallet. Therefore, in order to improve the positioning accuracy of the workpiece, it is necessary to improve the positioning accuracy of the pallet on the table.

The present invention was developed based on such a request, and an object of the present invention is to easily and accurately position a pallet on a table.

Embodiments embodying the present invention will be described in detail below with reference to the attached drawings. FIG. 1 is a front sectional view of a fluid cylinder used in a positioning device according to an embodiment of the present invention, and FIG. 2 is a front sectional view of the table and pallet used in the same device, showing a state in which the pallet is positioned on the table. , FIG. 3 is a front sectional view of a clamper used for fixing pallets.

In these figures, 1 is a fluid cylinder built into a table 2, and has a piston 3 that is slidable in the axial direction inside. Opening 4 of cylinder 1
A lid 5 that closes the opening 4 is attached via a seal ring 6. A bush 9 having a conical tapered surface 8 at the tip is slidably inserted into the sliding hole 7 bored in the center of the lid 5, and the lower end of the bush 9 is inserted into the nut 10. Therefore, it is fixed to the piston 3. When the bush 9 advances in the direction of arrow 12, the outer circumferential tapered surface 11 of the conical flange integrally provided on the intermediate body of the bush 9 opens the piston upper chamber 1 in the center of the lid member 5.
It has a shape that closely contacts the conical tapered inner surface 14 bored on the third side. The upper chamber 13 of the piston 3 in the piston chamber communicates with a fluid inlet 16 via a passage 15, and the lower chamber 17 of the piston 3 communicates with a fluid inlet 19 via a passage 18 bored in the cylinder 1 and the lid member 5. It's communicating. 20 and 21 are seal rings.

The lid member 5 is attached to the table 2 in an accurately positioned manner.

On the other hand, on the pallet p side, two positioning holes 22 are provided at positions corresponding to the bushes 9, into which the bushes are slidably and tightly fitted.
The tapered surface 8 may be formed at the end of the positioning hole 22 instead of being formed at the head 9' of the bush 9. This positioning hole 22 is configured as an inner hole of a replaceable cylindrical body 23 fixed to the pallet p.

Such pallets are transferred to the table 2 parallel to the top surface 24 of the table by an automatic pallet changer.
sent upwards. A guide roller 25 rotatably provided on a clamper 28 (described later) above the table
guides the pallet onto the table by supporting the ceiling surface of a long groove-like recess 26 with a generally T-shaped cross section formed on the lower surface of the pallet p. At this time, since the pressure at the fluid inlet 16 is high and the pressure at the fluid inlet 19 is controlled low, the piston 3 and the bushing 9 fixed thereto are
is pressed down, and the head 9' of the bush 9 is hidden below the table top surface 24. When the pallet p is brought to a fixed position on the table, the pressure at the fluid inlet 19 increases and the pressure at the fluid inlet 16 decreases, so that the piston 3 pushes up the bush 9. Since the bush 9 has a conical tapered surface 8 on its upper part, even if the center is slightly misaligned, the positioning hole 2 can be adjusted while correcting the position of the pallet p.
Go inside 2. Finally, the outer peripheral tapered surface 11 of the conical flange of the piston 3 fits into the tapered inner surface 14 at a fixed position, and the position of the bush 9 is determined accurately, so that the position on the pallet side is also corrected with high precision. Although the piston 3 is originally fitted into the sliding hole 7 with some play, the bush 9 is accurately positioned by the fit between the tapered inner surface 14 and the tapered collar 11. Once the position of the pallet is determined in this way, the clamper 28 on the table 2, which has entered the recess of the pallet p, is operated, and the pallet p is fixed to the table 2. The clamper 28 applies hydraulic pressure to a cylinder 30 that drives the clamp bar 29 up and down, so that the clamp bar 29 clamps (fixes) the pallet p to the table 2 by pressing down the upper surface 31 of the pallet recess. )do.

As described above, the present invention is provided with a bush 9 on the table 2 side that is vertically retractable from the top surface 24 of the table 2, and a head 9' of the bush 9 or a pallet p into which the bush 9 is inserted. A first tapered surface 8 is provided at the end of the side positioning hole 22.
Also, a second tapered surface 11 is formed on the intermediate barrel of the bush 9, and a tapered inner surface 14 corresponding to the second tapered surface is formed on the sliding portion 7 of the bush 9 formed on the table 2 side. On the other hand, a long groove-like recess 26 having a substantially T-shaped cross section is formed on the lower surface of the pallet p, and a clamper 2 that can engage with the upper surface 31 of the long groove-like recess 26 is formed on the table 2 side.
8 is provided to be movable up and down, and this clamper 28 has a
When the clamper 28 is raised, the long groove-shaped recess 2
A guide roller 25 is provided which supports the pallet p by rolling contact with the ceiling surface of the table 6, and when the clamper 28 is lowered, the pallet p comes into contact with the upper surface 24 of the table 2 and then moves away from the ceiling surface. Because it is a pallet positioning device for a table that moves, it is possible to position the pallet with extremely high precision and easily just by the protruding action of the bushing. Since it can be used for both movement and movement, the operation is simplified and reliable.Furthermore, since the pallet is clamped after the guide roller comes off the pallet, there is no possibility that the clamped pallet will easily move on the table. There are no inconveniences and it is suitable for use in machine tools that automatically exchange pallets.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a fluid cylinder used in a positioning device according to an embodiment of the present invention, FIG. FIG. 3 is a front sectional view of a clamper used for fixing pallets to a table. FIG. 4 is a perspective view of the clamper 28. Explanation of symbols: p...Pallet, 1...Cylinder, 2...Table, 9...Button, 8...Tapered surface, 14...Tapered inner surface, 11...Tapered collar.

Claims (1)

[Claims for Utility Model Registration] A bush 9 is provided on the side of the table 2, which is vertically retractable from the top surface 24 of the table 2, and a head 9' of the bush 9 or a pallet p into which the bush 9 is inserted is provided. A first tapered surface 8 is formed at the end of the positioning hole 22 on the side, and a second tapered surface 11 is formed at the intermediate body portion of the bush 9, and the sliding portion 7 of the bush 9 is formed on the table 2 side. A tapered inner surface 14 corresponding to the second tapered surface is formed, while a long groove-like recess 2 having a substantially T-shaped cross section is formed on the lower surface of the pallet p.
6, and a clamper 28 that can be engaged with the upper surface 31 of the long groove-shaped recess 26 on the table 2 side.
is provided to be movable up and down, and when the clamper 28 is raised, it rolls into contact with the ceiling surface of the long groove-shaped recess 26 to support the pallet p, and when the clamper 28 is lowered, the pallet p is placed on the table. The guide roller 25 separates from the ceiling surface after coming into contact with the upper surface 24 of 2.
A pallet positioning device for a table, characterized in that it is provided with.