JPH0356844B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a workpiece holding device using a collect chuck used in a machine tool.

<Prior Art> When a workpiece is held by a collect chuck, chips enter through the slits in the collet part that expand and contract in the radial direction, impeding the workpiece holding function. In order to prevent the intrusion of these chips,
As disclosed in No. 1, the spaces between the slits are closed with a shielding plate, or elastic rubber or the like is inserted between the slits. In other words, since the collet portion must allow expansion and contraction in the radial direction, it is intended to prevent chips from entering only from between the slits.
Chips and coolant can enter not only between the slits but also from the taper fitting surface on the outer periphery of the collet, but in the past, there has been little sealing performance to prevent chips and coolant from entering the taper fitting surface. I was in a terrible state.

<Object of the Invention> An object of the invention is to reliably prevent chips, coolant, etc. from entering not only the slit of the collet portion but also the taper fitting surface.

<Structure of the Invention> The structure of the present invention is such that a plurality of collect parts formed in the collector chuck are interconnected by a thin, flexible cylindrical part, and both inner and outer surfaces perpendicular to the direction of expansion and contraction of the collect part are connected to each other by a thin cylindrical part having flexibility. A protective sleeve is disposed to sandwich the thin cylindrical portion, and an end sealing material that contacts the thin-walled cylindrical portion is held in the protective sleeve.

<Examples> Examples of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is the chuck body.
A collector chuck 2 protruding in the axial direction from the front surface of the chuck body 1 is fixed concentrically with the chuck body 1. Reference numeral 3 designates a plurality of collect parts formed at the tip of the collect chuck 2. These collect parts 3 can be expanded and contracted in the radial direction, and a grip part for gripping the workpiece W is bent toward the center at the tip. There is. Reference numeral 4 designates an operating sleeve that is tapered fitted 14 to the outer periphery of the collet portion 3 and moves forward and backward in the axial direction to expand and contract the collet portion 3. The actuating sleeve 4 is held movably back and forth within a fixed sleeve 5 which is fixed to the chuck body 1 and has a gap on its outer periphery via a stroke bearing 6 interposed between the gaps. As shown in FIG. 2, it is operated by a fork-shaped operating lever 8 that is connected to a clamp cylinder 7 fixedly attached to the chuck body 1 and swings about a fulcrum part 9. be.

The plurality of collet parts 3 are interconnected by a flexible thin cylindrical part 10. Further, a first protective sleeve 11a fixed to the chuck body 1 is disposed on the distal end surface of the gripping portion formed at the tip of the collet portion 3, and a first protective sleeve 11a fixed to the chuck body 1 is disposed on the rear end surface of the gripping portion. A second protective sleeve 11b fixed to the first protective sleeve 11b is arranged to sandwich the gripping portion between the first protective sleeve 11a and the thin-walled cylindrical portion 10. A contacting ring-shaped end face sealing material 12 is held respectively. 13 is a positioning pin for the workpiece W that protrudes from the outer protective sleeve 11a.

Since the present invention is constructed as described above, when the actuating sleeve 4 is moved backward (moved to the left in Fig. 1) by the operation of the actuating lever 8, the collet part 3 of the collet chuck 2 is expanded and unclamped, and the collet part 3 of the collet chuck 2 is unclamped. Due to the movement (rightward movement in FIG. 1), the collet portion 3 is contracted by the taper fitting 14 and clamps the workpiece W. Then, the thin-walled cylindrical portion 1 is opened by allowing the collet portion 3 to expand and contract in the radial direction.
0 and the protective sleeves 11a and 11b prevent chips, coolant, etc. from entering between the slits of the collector portion 3 and into the taper fitting 14.

<Effects> As described above, the present invention forms workpiece gripping portions bent toward the center at the tips of a plurality of collet portions, and also connects the plurality of collet portions to each other by a thin, flexible cylindrical portion. A first protective sleeve fixed to the chuck body is arranged on the front end side of the workpiece gripping part of the collet part, and a second protective sleeve fixed to the chuck body is arranged on the rear end side of the workpiece gripping part of the collet part. Since the first and second protective sleeves each hold an end sealing material that contacts the thin cylindrical portion of the collet portion, the expansion and contraction function of the collet portion is not impaired in any way. It is now possible to reliably prevent chips, coolant, etc. from entering the taper fitting surface on the outer periphery of the collet from the inner circumferential side of the collet that grips the workpiece, and the workpiece can be held with high precision at all times. be.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the apparatus of the present invention, FIG. 2 is a cross-sectional view taken along the line of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line of FIG. DESCRIPTION OF SYMBOLS 1...Chuck body, 2...Collection chuck, 3...Collection part, 4...Operation sleeve, 1
0... Thin cylindrical portion, 11a, 11b... Protective sleeve, 12... End face sealing material.

Claims (1)

[Claims] 1. A workpiece holding device using a collect chuck, in which a plurality of collet parts are provided at the tip of the chuck so as to be expandable and retractable in the radial direction, and an operating sleeve that is tapered fitted to these collet parts to expand and retract the collet parts is provided in the chuck body so as to be movable forward and backward. A workpiece gripping portion bent toward the center is formed at the tip of the plurality of collet portions, and the plurality of collet portions are interconnected by a flexible thin-walled cylindrical portion, and the machining of the collet portion is performed. A first protective sleeve fixed to the chuck body is arranged on the front end side of the workpiece gripping part, and a second protective sleeve fixed to the chuck body is arranged on the rear end side of the workpiece gripping part of the collet part. A workpiece holding device using a collect chuck, wherein the first and second protective sleeves each hold an end sealing material that contacts the thin cylindrical portion of the collect portion.