JP3273824B2 - Lathe chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lathe chuck for correctly grasping a rectangular work with four claws.

[0002]

2. Description of the Related Art When grasping a rectangular work, there is a work in which the work is grasped by four chuck claws arranged at a phase of 90 ° with respect to the center of rotation of the chuck body.

[0003]

In the case of a four-jaw chuck as described above, if each chuck is structured so as to advance and retreat at the same time with one draw bar, if the work is not square, any one of the pieces of the work is used. There is a gap between the chuck claws, and it is not possible to accurately grasp them. In addition, even if the work is square, if there is a slight error, any of the chuck claws will float.

An object of the present invention is to solve the above-mentioned problems of the conventional chuck for lathes, and to move four chuck claws by moving one draw bar forward and backward to form a quadrangular shape having a vertical and horizontal dimension difference. An object of the present invention is to provide a lathe chuck capable of accurately and strongly grasping even a work.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a pair of main chuck claws which are opened and closed by an opening / closing mechanism which is directly operated by a reciprocating movement of a draw bar provided at a rear portion of a chuck body. On the front of the body,
A pair of auxiliary chuck claws, which are arranged so as to face each other with the rotation center interposed therebetween and are opened and closed by an interlocking mechanism that transmits the action of the draw bar via a spring, are provided on the front surface of the chuck main body at 90 ° with the main chuck jaws. A configuration is adopted in which the phase is provided so as to oppose the rotation center of the chuck body with a phase therebetween.

[0006]

[Effect] A rectangular work is inserted between four chuck claws arranged on the front surface of the chuck body. Next, when the draw bar is retracted, an interlocking mechanism with a spring intervening first acts, and each sub chuck pawl grasps one side surface of the work.

Further, when the draw bar is retracted, an interlocking mechanism for directly transmitting the movement of the draw bar to the main chuck acts to activate the main chuck pawls, thereby firmly fixing the other two side surfaces of the work.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, reference numeral 1 denotes a chuck mounting plate fixed to the tip of a main shaft of a lathe (not shown) by bolts, and reference numeral 2 denotes a rear wall of a chuck body 3 fixed to the front surface by bolts. As shown in FIG. 2, a pair of inclined holes 4 extending from the front surface to the rear portion are formed in the main body 3 so as to extend forward from the center of rotation of the main body 3 at positions equal to the center.

Also, as shown in FIG. 3, the main body 3 has a pair of inclined holes 5 extending from the front surface to the rear with a phase of 90.degree. It is formed in a front spread shape at the position.

In FIG. 2, reference numeral 6 denotes a rod-like body fitted in the inclined hole 4 for sliding use, and a main chuck pawl 7 is fixed to a tip end thereof with a bolt 9. A recess 10 is formed at the center of the rear part of the main body 3, and a guide hole 11 concentric with the main body 3 is provided at the center thereof,
The front opening is closed with a removable lid 12. 3 in FIG.
Reference numeral 3 denotes a rod-like body which is slidably fitted in the inclined hole, and a sub-chuck claw 14 is fixed to a tip end thereof with a bolt 15.

Reference numeral 16 in FIGS. 2 and 3 denotes a draw bar penetrating through the main shaft of the lathe, and a bolt 17 is fixed to the tip of the draw bar. The bolt 17 slidably penetrates the center hole of the rear end wall of the outer cylinder 19 slidably fitted in the center hole of the rear wall 2. An inner cylinder 20 is slidably fitted in the outer cylinder 19, and a front portion of the bolt 17 is slidably fitted in a center hole of the inner cylinder 20. Is fitted in the large-diameter hole 22 at the front of the inner cylinder 20.

A pressing spring 23 is fitted on the rear portion of the outer cylinder 19 to push the rear end of the inner cylinder 20 forward. The front part of the inner cylinder 20 is slidably fitted in the guide hole 11,
A pair of engaging pieces 25 are integrally provided on both sides of the outer peripheral intermediate portion of the inner cylinder 20, and the respective pieces 25 are fitted into engaging recesses 26 inside the rear portion of each rod 6 as shown in FIGS. 1 and 2. Engage.

The engaging pieces 2 are provided above and below the front part of the outer cylinder 19.
5 is formed from the front end, and a pair of engaging pieces 3 are provided on both sides of the outer cylinder 19 between the notches 27.
0 are integrally formed. Then, the two engagement pieces 30 are connected to each other as shown in FIG.
As described above, each of the rods 13 is engaged with the engagement recess 31 inside the rear part.

A nut 32 is screwed into the male screw of the bolt 17, and an appropriate gap is provided between the nut 32 and the rear end of the outer cylinder 19. In addition, reference numeral 33 in FIG. 2 denotes a groove at the front part of the inner periphery of the outer cylinder 19, which is engaged with a detent pin 34 fixed to the outer periphery of the inner cylinder 20. The projecting detent pin 36 is engaged with the engaging recess 26 of the body 6. It is preferable that the cross section of each of the inclined holes 4 and 5 and the rods 6 and 13 is formed in a partially circular shape so as not to turn over a predetermined range.

Next, the operation of the above embodiment will be described. FIG.
Or FIG. 3 shows a state where a square work A is grasped,
At this time, the draw bar 16 is at the most retracted position, the upper and lower main chuck claws 7 sandwich the upper and lower surfaces of the work A, and the left and right auxiliary chuck claws 14 sandwich the both side surfaces of the work A.

The upper and lower main chuck pawls 7 pull the inner cylinder 20 rearward on the rear side of the large-diameter head 21 of the bolt 17 integrated with the draw bar 16, and engage the engaging piece 25 of the inner cylinder 20 with the rod 6. Since the upper and lower surfaces of the work A are grasped by pulling the rod-shaped body 6 backward through the engagement of the joint concave portion 26, a large grasping force can be obtained.

The rear end of the inner cylinder 20, which is pulled by the draw bar 16, compresses the spring 23 of the left and right auxiliary chuck claws 14, and pulls the outer cylinder 19 rearward by the compression force of the spring 23. 19 engagement piece 30 and rod-shaped body 13 engagement recess 31
The two side surfaces of the work A are grasped by pulling the rod 13 backward through the engagement of.

Therefore, even if the upper and lower widths and the left and right widths of the work A are not the same, the chuck claws 7 and 14 come into close contact with the respective surfaces of the work A and reliably grasp the work A due to the difference in the amount of compression of the spring 23. Accurate cutting can be performed.

When the processing is completed, the draw bar 16 is advanced. When the draw bar 16 moves forward, the inner cylinder 20 moves forward first, and the upper and lower main chuck claws 7 are opened to release the work A from being grasped vertically. During this time, the left and right auxiliary chuck claws 14 keep grasping the work A because the spring 23 is working.
The draw bar 16 is further advanced, and the nut 32 is moved to the outer cylinder 19.
When the outer cylinder 19 is advanced by pushing the rear end of the
Moves forward, and the auxiliary chuck claws 14 release the left and right grasp of the work A.

Accordingly, the work A which has been processed is taken out by a manipulator or the like at an appropriate stage until the auxiliary chuck pawl 14 is completely separated from the work A.

When the grasp of the work A is released in this way,
The draw bar 16 advances most, the front end of the outer cylinder 19 and the front surface of the engagement piece 25 of the inner cylinder 20 hit the bottom of the recess 10, the rear surface of the large-diameter head 21 of the bolt 17 and the inner end surface of the large-diameter hole 22. There is a gap between them.

In the above-mentioned unclamped state, the work A to be processed next is inserted between the chuck claws 7 and 14 by a manipulator or the like, and the draw bar 16 is retracted. The left and right auxiliary chuck claws 14 grasp both sides of the work A lightly.
The rear side of the large-diameter head 21 of the bolt 17 is the large-diameter hole 2 of the inner cylinder 20.
2, the bar 6 starts to retreat together with the draw bar 16, and the upper and lower main chuck claws 7
Between the upper and lower surfaces.

[0023]

According to the lathe chuck of the present invention, one side surface of a rectangular work is grasped by a pair of main chuck claws which advance and retreat together with a draw bar, and a pair of sub chucks grasping the other side surface are not directly moved by a draw bar. In addition, since the workpiece is moved via a spring, even a rectangular work having a width on one side surface and a width on the other side surface different from each other can be accurately grasped by operating each chuck claw by one draw bar.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment.

FIG. 2 is a longitudinal sectional side view taken along line II of FIG. 1;

FIG. 3 is a cross-sectional plan view taken along the line II-II of FIG.

FIG. 4 is an exploded perspective view of a main part of the same.

[Explanation of symbols]

 Reference Signs List 3 chuck body 4 inclined hole 5 inclined hole 6 rod 7 main chuck pawl 13 rod 14 sub chuck pawl 16 draw bar 17 bolt 19 outer cylinder 20 inner cylinder 21 large diameter head 22 large diameter hole 23 pressing spring 25 engagement piece 26 Engaging recess 30 Engaging piece 31 Engaging concave 32 Nut

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23B 31/173 B23B 31/10 B23B 31/12

Claims (1)

(57) [Claims] 1. An opening / closing mechanism which is directly operated by a forward / backward movement of a draw bar 16 provided at a rear portion of the chuck body 3 .
A pair of main chuck claws 7 that are opened and closed in the radial direction of the chuck body 3 are arranged on the front surface of the chuck body 3 so as to face each other with the center of rotation therebetween, and the action of the draw bar 16 is performed via a spring 23 . the blood by interlocking mechanism for transmitting Te
A pair of auxiliary chuck claws 1 that open and close in the radial direction of the jack body 3
4, the front of the chuck body 3, with the main chuck claws 7 and 90 ° of phase, the lathe chuck provided so as to face across the rotational center of the chuck body 3, integrated with the main chuck claws 7 The inner cylinder 20 linked to
Slidably fits on the outer cylinder 19 that interlocks with the hook 14
And the spring 23 is interposed between the inner cylinder 20 and the outer cylinder 19.
And the bolt 17 is slidable on the inner cylinder 20 and the outer cylinder 19
When the drawbar 16 is retracted, it is screwed into the drawbar 16 and fixed through the spring 23.
Then, the outer cylinder 19 is retracted, and
Close the pair of auxiliary chuck claws 14, and move the large-diameter head of the bolt 17.
21 hits the inner cylinder 20 and retracts the inner cylinder 20
And the inner cylinder 20 and the opening / closing mechanism that operates directly
When the pair of main chuck claws 7 are closed and the draw bar 16 is advanced , the draw bar 16 is moved through the spring 23.
Then, the inner cylinder 20 moves forward and works directly with the inner cylinder 20.
The pair of main chuck claws 7 are opened by a moving opening / closing mechanism,
The draw bar 16 pushes the rear end of the outer cylinder 19 to
The outer cylinder 19 moves forward and the pair of sub
A chuck for a lathe, characterized in that the chuck jaws 14 are opened.