JPH065813U - Multi-point gripping chucking device - Google Patents

Abstract

(57) [Summary] [Purpose] Attach to an existing 3-jaw power chuck,
Securely grips the workpiece at multiple points without deforming it. [Structure] A base 5 is detachably attached to the front surface of the three-jaw power chuck 1. A claw member 8 is inserted into the taper hole 7 of the base 5 and is fastened to the center of the power chuck 1 by the bolt 9 of the work positioning stopper 13. Six gripping claws 11 are integrally provided on the claw member 8 via slits 10. The slider 16 is inserted into the guide hole 15 of the base 5, and the slanted cam portion 17 is attached to the engaging portion 18 of the chuck claw 2.
Bite into. A cover plate 20 is connected to the slider 16, and a taper hole 21 for opening and closing each grip claw 11 is formed in the cover plate 20. Each grip claw 11 is interlocked with the opening and closing of the chuck claw 2 and is opened and closed in the opposite direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multi-point gripping chucking device which is attached to a three-jaw power chuck and grips a work at, for example, six points.

[0002]

[Prior art]

 Conventionally, a 3-jaw power chuck 1 as shown in FIGS. 6 and 7 has been widely used in lathes and the like. However, since the power chuck 1 is provided with only three chuck claws 2, when the thin cylindrical work W is gripped, the gripping force of the chuck claw 2 deforms the work W into a rice ball shape. However, there is a problem in that it is easy and the finishing accuracy such as roundness is deteriorated. Further, since there are three gripping points, the work W may not be gripped reliably, which is a problem in terms of safety. Therefore, it is possible to use another power chuck with more chuck jaws, but in this case, the power chuck must be replaced according to the type of work piece, which is a very troublesome work. Met.

[0003]

[Problems to be solved by the device]

 An object of the present invention is to provide a chucking device which can be attached to an existing three-jaw power chuck and used, and which can securely grip at multiple points without deforming the work.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the multi-point gripping chucking device of the present invention has a base removably attached to the front surface of a three-jaw power chuck, and the base can be opened and closed around the same axis as the power chuck. A plurality of gripping claws mounted on the power tool and an opening / closing mechanism that opens and closes each gripping claw in synchronization with the chuck claws of the power chuck. The opening / closing mechanism opens and closes the gripping claws in the direction opposite to the chuck claws. Is provided.

[0005]

[Action]

 Since the chucking device of the present invention is provided with a plurality of gripping claws, the gripping force per point can be reduced, and even when gripping a thin cylindrical work, there is no risk of deformation of the work, and a highly accurate circular shape is obtained. Processing becomes possible. Further, since there are a plurality of grip points, the work can be gripped reliably and safety is improved. Moreover, the chucking device can be easily attached to and detached from the existing three-jaw power chuck via the base, and in the mounted state, the opening / closing mechanism uses the movement of the chuck jaws to open and close the gripping jaws. There is no need to provide any drive source on the device side. Furthermore, since the cam part of the opening / closing mechanism opens and closes the grip claw in the direction opposite to the chuck claw, when the chuck claw is urged in the opening direction by centrifugal force, the grip claw will The work piece is urged in the closing direction, so that the gripping force can be further enhanced and the work can be chucked reliably and safely.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, 1 is a power chuck similar to the conventional one, which has three chuck claws 2 and is mounted on a spindle 3. Reference numeral 4 denotes the entire chucking device of this embodiment, and the base 5 of the device 4 is detachably attached to the front surface of the power chuck 1 by means of bolts 6.

An open taper hole 7 is bored in the center of the base 5, and a hollow truncated cone-shaped claw member 8 is inserted into the taper hole 7. It is fastened to the center of the ku 1. A slit 10 is formed on the claw member 8 at a position that divides the circumference into six equal parts, and six elastically deformable gripping claws 11 are integrally provided by each slit 10, and the same axis line as that of the power chuck 1 is provided. It can be opened and closed around. A grip portion 12 for gripping the work W is formed in an arc shape on the inner peripheral surface of the tip of each grip claw 11 (see FIG. 5). The bolt 9 is provided at the base end of the stopper 13 that determines the gripping position of the work W in the axial direction of the claw member 8.

A recess 14 for accommodating the chuck claw 2 is formed on the back surface of the base 5, and a guide hole 15 communicating with the recess 14 is formed in the outer peripheral portion of the base 5 in parallel with the axis of the claw member 8. ing. A slider 16 is slidably inserted in the guide hole 15, and a cam portion 17 formed of an inclined groove is formed at the inner end of the guide hole 15, as shown in FIGS. An engaging portion 18 meshing with the cam portion 17 is formed obliquely on the outer surface of the chuck claw 2, and the slider 16 is moved along with the opening movement of the chuck claw 2 through the engagement of the cam portion 17 and the engaging portion 18. It is adapted to be projected from the base 5 and to be immersed in the base 5 as the chuck claw 2 is closed and moved.

A cover plate 20 is integrally movably coupled to the outer end of the slider 16 by a bolt 19, and a taper hole 21 for opening and closing the grip claw 11 is formed in the center of the cover plate 20. An opening / closing mechanism is configured by the cover plate 20 and the slider 16, and the gripping claws 11 are opened and closed in the opposite direction in association with the opening and closing of the chuck claws 2 by the mechanism.

Next, the operation of the chucking device 4 configured as described above will be described. When gripping the work W, the chuck claw 2 of the power chuck 1 is driven in the opening direction with the work W inserted into the claw member 8 and positioned by the stopper 13. Then, the slider 16 slides in the direction of protruding from the base 5 by the action of the inclined surfaces of the engaging portion 18 and the cam portion 17. Then, the cover plate 20 is moved together with the slider 16, and the respective gripping claws 11 are simultaneously closed around the same axis as the power chuck 1 by the taper hole 21 to grip the work W.

In this case, since the gripping members 8 are provided with the six gripping claws 11, the gripping force per point can be reduced, and the work W is deformed even when gripping a thin cylindrical work W. There is no fear of this, and high-precision round machining is possible. Further, since there are 6 gripping points, the work W can be reliably gripped and the safety is improved. In addition, since the cam portion 17 of the opening / closing mechanism acts to open and close the grip claw 11 in the direction opposite to the chuck claw 2, when the chuck claw 2 is urged in the opening direction by centrifugal force during high speed rotation, On the contrary, the gripping claw 11 is biased in the closing direction, whereby the gripping force can be further enhanced, and the workpiece W can be chucked reliably and safely.

On the other hand, when the work W is released, the chuck claw 2 is driven in the closing direction. Then, the slider 16 is slid in the direction in which the slider 16 is retracted into the base 5 due to the engagement between the engaging portion 18 and the cam portion 17. At the same time, the cover plate 20 is moved to the base 5 side, the tapered hole 21 thereof is disengaged from the gripping claws 11, and the respective gripping claws 11 open simultaneously and release the work W by their elasticity.

As described above, the chucking device 4 of this embodiment can be easily attached to and detached from the existing three-jaw power chuck 1 via the base 5 for use. Further, in the mounted state, since the opening / closing mechanism uses the movement of the chuck claw 2 to open and close the grip claw 11, it is not necessary to provide any driving source on the chucking device 4 side, and the entire device is simple and lightweight. It is possible to Moreover, since the grip portion 12 of the grip claw 11 is formed in an arc shape, as shown in the upper side of FIG. 5, when the diameter of the work W is small, the tip of the grip portion 12 (point C) is the work W. In addition, as shown in the lower side of FIG. 5, when the diameter of the work W is large, the inner back part (point D) of the gripping part 12 makes line contact with the work W. The range of work diameters that can be gripped can be expanded, improving versatility. When the work W having a small diameter is gripped, an adjustment washer 22 having an appropriate thickness is attached to the bolt 9 so that the stopper 13 can accurately position the work W.

In the above embodiment, the gripping claws 11 are provided on the claw member 8 in six pieces, but the present invention is not limited to this, and the number of the gripping claws 11 is four, five, or seven or more. It can also be implemented. In addition, the shape and configuration of each part may be appropriately changed and embodied, for example, by changing the shape of the grip claw 11 or changing the configuration of the opening / closing mechanism, without departing from the spirit of the present invention. It is possible.

[0015]

As described in detail above, according to the present invention, a plurality of gripping claws are attached to the base, and the gripping claws are configured to be opened / closed by the opening / closing mechanism in conjunction with the chuck claws. By attaching the chucking device to the existing three-claw power chuck, it is possible to reliably grip the workpiece at multiple points without deforming it.

Further, since the opening / closing mechanism is provided with the cam portion that opens and closes the grip claw in the direction opposite to the chuck claw, when the chuck claw is urged in the opening direction by the centrifugal force, the grip claw is urged in the closing direction. The gripping force can be further increased by urging the work, and thus the work can be reliably and safely chucked.

[Brief description of drawings]

FIG. 1 is a sectional view of a chucking device showing an embodiment of the present invention.

FIG. 2 is a front view of the chucking device of FIG.

FIG. 3 is an enlarged view of a portion A of FIG.

4 is a cross-sectional view taken along the line BB of FIG.

5 is an enlarged view of the grip claw of FIG. 1. FIG.

FIG. 6 is a front view of a power chuck for explaining conventional problems.

FIG. 7 is a side view of the power chuck of FIG.

[Explanation of symbols]

1 ... power chuck, 2 chuck chuck, 3 main spindle, 4 chucking device, 5 base, 6, 9,
19 ... Bolts, 7 and 21 ... Tapered holes, 8 ... Claw members, 10 ... Slits, 11 ... Gripping claws, 12 ... Gripping sections, 13 ... Stoppers, 14 ... Recesses, 15 ... Holes, 16-slider, 17-cam part, 18-engagement part, 20-cover plate, 22-washer.

Claims (1)

[Scope of utility model registration request] 1. A base removably attached to the front surface of a three-jaw power chuck, a plurality of gripping claws mounted on the base so as to be openable and closable around the same axis as the power chuck, and the gripping claw is a power chuck. It is composed of an opening and closing mechanism that opens and closes in conjunction with the chuck claw of
A multi-point gripping chucking device comprising a cam portion that opens and closes the grip claw in a direction opposite to the chuck claw.