JPH0526210U - Chuck for machine tools - Google Patents

Abstract

(57) [Abstract] [Purpose] The shape of a single jaw of a chuck for machine tools,
Allows gripping of multiple types of workpieces of different sizes,
To shorten the work time for setup change when changing the work. A top jaw having a plurality of work gripping portions that are different from each other in a radial direction of a peripheral portion is rotatably fitted to a base jaw, and the base jaw and the top jaw are fixed by a positioning member and a fixing member.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a jaw of a chuck mounted on a machine tool such as a lathe.

[0002]

[Prior Art]

 A chuck installed on a machine tool such as a lathe has a plurality of jaws fixed to it, and this jaw is used to open or close the work manually or by air pressure, hydraulic pressure, etc. to fix the work. A suitable jaw is selected and fixed.

FIG. 4 shows an example of a drawdown type power chuck in which conventional air pressure, hydraulic pressure, etc. are used. The jaw B is fixed to the tip surface of the drawbar A with bolts C and D, and the chuck body E The work is gripped by a plurality of jaws B arranged on the front face F in the circumferential direction.

The jaw B of the conventional chuck is used by selecting and fixing a jaw suitable for the shape and size of the work, and when the work is changed and the bolts are changed every time the setup is changed. C and D must be removed, replaced with another jaw, and fixed again with bolts C and D, which causes a problem that the preparation work time becomes long.

[0005]

[Problems to be solved by the device]

 In order to solve the above-mentioned problems of the prior art, the present invention only needs to provide different work gripping portions on the outer peripheral edge of a single jaw, and rotate the jaw around the center thereof as a rotation center. It is an object of the present invention to provide a chuck for a machine tool that can bring a work gripping part suitable for a work of different shape and size to the work gripping position and reduce the preparation work time.

[0006]

[Means for Solving the Problems]

 According to the present invention, in order to solve the above problems, a top jaw attached to each of a plurality of base jaws assembled to a chuck body is provided so as to project from the center of the top jaw in parallel with the axis of the chuck body. A cylindrical boss portion is rotatably fitted to the base jaw, and a plurality of workpiece gripping portions different from each other are radially formed on the outer peripheral edge portion of the top jaw, and the base jaw and the top jaw are formed. The jaw has a structure in which a positioning member when the selected workpiece gripping portion occupies the workpiece gripping position and a fixing member for both jaws are provided.

[0007]

[Action]

 The chuck with the jaw according to the present invention loosens or removes the fixing member for the base jaw and the top jaw and the positioning member for the top jaw, and then the work gripping portion suitable for the shape and size of the work is provided. The preparation work is completed by rotating the top jaw around the cylindrical boss so as to occupy the work gripping position, and fixing the positioning member and the fixing member.

When the setup is changed due to the change of the work, it is sufficient to repeat the above work again.

[0009]

【Example】

 FIGS. 1, 2 and 3 show an example of an embodiment applied to a drawdown type power chuck, in which a bolt 2 and a positioning projection 3 are attached to a drawbar 1 assembled to a chuck body (not shown). And the base jaw 4 is fixed.

As described with reference to FIG. 4, a plurality of drawbars 1 and base jaws 4 are arranged in a circumferentially even arrangement in front of the chuck body, but only one is shown in FIG. There is.

The top jaw 5 attached to the base jaw 4 has a cylindrical boss portion 6 projecting from the center of the top jaw in parallel with the axis of the chuck body. It is rotatably fitted in the hole 7 and is fixed to the base jaw 4 and the draw bar 1 by a fixing member 8 which is a bolt passing through the central portion.

A plurality of work gripping portions 9, 10, 11 having different shapes and sizes from each other are radially formed on the outer peripheral edge portion of the top jaw 5.

As shown in FIG. 3, the work holding parts 9, 10, 11 in the illustrated example are arc surfaces having different radii, and relief recesses 12, 13, 14 are cut in the center to remove chips. In order to ensure the close contact between the work and the work gripping parts 9, 10, 11, the through hole of the fixing member 8 as the bolt penetrates through the center of the cylindrical boss part 6. 15 have been opened.

A positioning member 19 including pin holes 16 and 17 and a bolt pin 18 is provided in the base jaw 4 and the top jaw 5, and is selected from the workpiece gripping portions 9, 10 and 11, for example. As shown in FIGS. 1 and 2, the work gripping portion 9 is arranged so that it can be positioned and fixed when the work gripping position is occupied.

Although three sets of positioning members 19 are provided in the illustrated example, one set may be provided.

In FIG. 2, the cutout portion 20 formed in the base jaw 4 directly below the work gripping portion 9 prevents interference between the work and the base jaw 4 regardless of which work gripping portion is selected. To do.

Although the illustrated example is an embodiment applied to a drawdown type power chuck, in the case of a wedge type chuck, a base jaw 4 and a top jaw 5 are attached to a master jaw.

As shown in FIGS. 1 and 2, when the work gripping portion 9 occupies the work gripping position, in order to bring the work gripping portion 10 to the work gripping position by setup change, for example, the bolt pin of the positioning member 19 is used. 18 is removed, the bolt serving as the fixing member 8 is loosened, the top jaw 5 is rotated with respect to the base jaw 4 about the cylindrical boss portion 6 as a rotation center, and the work gripping portion 10 is brought to the work gripping position, and the positioning member 19 is positioned. The bolt pin 18 is inserted into the pin holes 16 and 17 and screwed to determine the position of the work grip 10 and fix it.

In order to prevent the bolt pin 18 from falling off or being lost during the above-mentioned setup change, the tip of the bolt pin 18 is a large diameter portion 21, and this large diameter portion is a large diameter hole at the bottom of the pin hole 17 of the top jaw 5. 16 and the large diameter pin hole 22 of the base jaw 4.

Then, the top jaw 5 is fixed to the base jaw 4 by screwing the bolt as the fixing member 8, and the work for holding the work by the work holding portion 10 is completed.

[0021]

[Effect of the device]

 In the present invention, since a plurality of different work gripping portions are formed on the outer peripheral edge of one top jaw, one top jaw can grip a plurality of works having different shapes and sizes. This has the effect of reducing the man-hours for managing the chuck jaws.

The top jaw is rotatably fitted to the base jaw by the cylindrical boss portion, and the top jaw and the base jaw can be firmly fixed and firmly positioned and fixed by the positioning member and the fixing member. By simply loosening or removing the fixing member and the fixing member, rotating the top jaws, fixing and fixing again with both members, the setup change is completed, so the preparation work can be speeded up and the workability can be improved. Have a positive effect.

Further, the top jaw is fitted to the base jaw by the cylindrical boss portion, and is rotated while keeping the fitted posture to bring the selected work gripping portion to the work gripping position, which serves as a mounting reference for the top jaw. No foreign matter is caught in the mounting surface, which has the effect of enabling highly accurate work gripping.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an example of an embodiment.

FIG. 2 is a perspective view of only a main part of what is shown in FIG.

3 is a plan view of the top jaw shown in FIG. 1. FIG.

FIG. 4 is a side view showing a cross section of a part of a conventional drawdown type power chuck.

[Explanation of symbols]

 4 Base Jaw 5 Top Jaw 6 Cylindrical Boss 8 Fixing Member 9, 10, 11 Work Holding Part 19 Positioning Member

Claims (1)

[Scope of utility model registration request] 1. A top jaw attached to each of a plurality of base jaws assembled to a chuck body has a cylindrical boss portion projecting from a central portion of the top jaw in parallel with an axis of the chuck body. The top jaw is rotatably fitted, and a plurality of work gripping portions different from each other are radially formed on the outer peripheral edge portion of the top jaw, and the base jaw and the top jaw are selected. A jaw of a machine tool chuck provided with a positioning member and a fixing member for both jaws when the workpiece gripping portion occupies the workpiece gripping position.