JPS6243698Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a workpiece gripping device that grips the inner circumference of a cylindrical workpiece using a collect chuck. The purpose is to make it easy to grasp.

Generally, when grinding the outer circumference of a cylindrical workpiece, the inner circumference of the workpiece is gripped by a collect chuck and the workpiece is rotated. Since the expanding and contracting actuating rod is connected to a reciprocating device such as a hydraulic cylinder, it is extremely difficult to replace the collet chuck, making it virtually difficult to grip workpieces with different inner diameters.

The present invention has been devised in view of the above-mentioned conventional problems, and embodiments thereof will be described below with reference to the drawings. 1 and 2, reference numeral 10 indicates a headstock, and a main shaft 11 connected to a drive motor (not shown) is rotatably supported on the headstock 10. As shown in FIG. A chuck unit 12 is attached to the tip of the main shaft 11.
The chuck unit 12 is made up of a support face plate 13, a collection chuck 14, an actuating rod 15, and a spring 16.

The support face plate 13 has a plurality of round holes 17 at equal positions on the circumference, and is fixed to the tip end surface of the main shaft 11 by tightening bolts 18 passing through the small diameter portions of these round holes 17. . The collector chuck 14 is fixed to the inner surface of the support face plate 13 concentrically with the main shaft 11, and the support face plate 13 is attached to the tip end thereof.
An expandable and retractable collet portion 19 is provided which penetrates through the support face plate 13 and protrudes to the front of the support face plate 13 to grip and clamp the inner periphery of the cylindrical workpiece W. The actuating rod 15 is fitted into the collet chuck 14 so as to be movable in the axial direction, and the collet portion 19 is attached to the distal end of the actuating rod 15.
A tapered part 20 is formed to expand and contract the collector chuck 14, and a stop plate 21 is fixed to the rear end of the collect chuck 14 at the rear end.
It passes through and faces into the main shaft 11. The spring 16 is connected to the collector chuck 14 and the actuating rod 1.
The normally operating rod 15 is held at the retracted end position in contact with the stop plate 21 by the force of the spring 16, and the collet portion 19
is usually kept in a reduced size.

A plurality of chuck units 12 having such a configuration are provided with collect chucks 14 having different gripping diameters so as to be able to handle workpieces W having different inner diameters.

In addition, a forward/backward driving cylinder 23 is provided in the main shaft 11.
A pressing rod 24 connected to the pressing rod 24 is inserted so as to be movable axially forward and backward, and the tip of the pressing rod 24 faces the rear end of the operating rod 15. When the pressing rod 24 is advanced by the forward and backward drive cylinder 23, the pressing rod 24 advances the operating rod 15 against the spring 16, and the taper portion 2
The collet portion 19 is enlarged by the insertion of the collet 19a. Reference numeral 25 denotes a tailstock center for supporting one end of the workpiece W at the center, and 26 denotes a grinding wheel for grinding the outer periphery of the workpiece W.

Since the device of the present invention is constructed as described above, the cylindrical portion of the workpiece W is attached to the collet portion 19 of the collet chuck 14, and the forward and backward drive cylinder 23
When the workpiece W is moved forward, the actuating rod 15 is moved forward by the pressing rod 24 against the spring 16, and the collet part 19 is expanded by the taper part 20, so that the inner periphery of the workpiece W is firmly gripped and clamped.

In addition, when gripping a workpiece W with a different inner diameter, slightly loosen the tightening bolt 18 and tighten the support face plate 13.
The chuck unit 12 can be quickly removed by simply rotating the chuck clockwise by an angle θ in FIG. A chuck unit 12 including a chuck unit 15 is attached to the tip of the main shaft 11.

Therefore, according to the present invention, the chuck unit can be quickly installed and removed by the round holes formed in the support face plate, and can be converted to a collect chuck according to the inner diameter of the workpiece with extremely simple setup changes. The effect is produced.

Moreover, according to the present invention, since the actuating rod holds the collet section in the direction of contraction due to the action of the spring, no unreasonable force is applied to the collet section even when the chuck unit is removed from the main shaft. Therefore, the effect of not damaging the collet part can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a workpiece gripping device showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the - line in FIG. 10... Headstock, 11... Spindle, 12... Chuck unit, 13... Support face plate, 14... Collet chuck, 15... Operating rod, 16... Spring, 19... Collet section, 23... Advance/retreat drive means , 24... Pressing rod, W... Workpiece.

Claims (1)

[Scope of utility model registration request] A spindle is rotatably supported on the headstock, and a chuck unit is removably inserted into the tip of the spindle.
This chuck unit includes a supporting face plate which has a plurality of round holes on the circumference and is removably fixed to the tip surface of the main shaft by means of tightening bolts passing through the round holes, and a collector chuck fixed to the inner surface of the supporting face plate. The collet chuck has an expandable and retractable collet part provided on the collet chuck and protrudes forward from the support face plate to grip the inner periphery of the workpiece, and a taper part for expanding and contracting the collet part. It consists of an actuating rod held movably in the axial direction within the collet chuck, a spring that presses the actuating rod in a direction to contract the collet portion, and a pressing rod facing one end of the actuating rod. A workpiece gripping device, which is provided in the main shaft so as to be movable in the axial direction, and is connected to the pressing rod with a reciprocating driving means for pressing the actuating rod in a direction to enlarge the collet portion against the spring.