JPS6116003Y2 - - Google Patents

Description

[Detailed Description of the Invention] The object of this invention is to provide a collet chuck in which the diameter of the collet is reduced in accordance with the external precision of the object to be held, and the holding force for the object to be held is uniform.

In conventional collector chucks, the axial generatrix of the conical hole in the sleeve that engages the conical portion of the collector is a straight line. Therefore, depending on the degree of diameter reduction of the collect, the contact between the conical part and the conical hole may be uneven, or the error in the cone angle of the conical part or the conical hole, or the cylindricity or roundness of the object to be held may be affected. As a result, the holding force becomes uneven, and the object to be held is partially deformed, which has an adverse effect on the accuracy of inner diameter machining and assembly of the object.

This invention solves the above-mentioned conventional drawbacks, and is characterized in that the axial generatrix of the conical hole of the sleeve that engages with the conical part of the outer diameter collet is formed to have a slightly convex shape. . An embodiment of this invention will be described below with reference to the drawings. Reference numeral 1 denotes a spindle, which is rotatably supported by a headstock 2 via a bearing 3. A sleeve 5 is inserted into the tip of the spindle 1 so as to be slidable in the axial direction, and is moved left and right by a known push/pull means. This sleeve 5
A conical hole 51 is formed at the tip of the conical hole, and the axial generatrix of this conical hole is formed into an arcuate curve with a large radius of curvature, with the center of the generatrix protruding a small amount toward the axis, as shown in the figure. has been done. Reference numeral 6 denotes a collet, the outer diameter 61 of which is formed in a conical shape with a linear generatrix, and the collet 6 has a conical hole 51 in the shape of a flap in the sleeve 5.
The object W to be held is held by the parts B and C at both ends of the collet 6. It's becoming like that. Note that 4 is a foot for positioning the collet 6 with respect to the spindle 1.

In the collect chuck of the present invention having the above configuration,
When the sleeve 5 is pushed in the direction of the arrow by the known push/pull means, the contact portion A presses the collet 6.
The outer diameter of the object W to be held is held at the portions B and C. At this time, due to the force relationship between the three points A, B, and C, a uniform holding force is applied to parts B and C, and the collet 6 maintains the outer diameter accuracy (cylindricity, roundness) of the object to be held. Since the diameter is reduced, the object to be held can be prevented from being deformed.

As is clear from the above explanation, since the collect chuck of the present invention applies a uniform force to hold the object, the above-mentioned conventional drawbacks are overcome, and the accuracy of the cone angle of the sleeve and the collect or the object to be held is improved. Even if the outer diameter accuracy is slightly off, the object to be held can be held securely without being deformed. This is particularly effective when the object to be held is thin-walled and tubular.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of an embodiment of the present invention. Explanation of symbols: 1...Spindle, 5...Sleeve, 6...Collection, W...Object to be held.

Claims (1)

[Scope of utility model registration request] The central part of the axial generatrix of the conical hole that engages with the conical part of the sleeve of the sleeve that compresses the conical part of the outer diameter collet to reduce the diameter of the collet is made to protrude a small amount toward the axis side, and the generatrix is A correct chuck characterized by being formed into an arcuate curve with a large radius of curvature.