JP3284579B2 - Finger chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a finger chuck used by being attached to a spindle of a machine tool.

[0002]

2. Description of the Related Art Conventionally, there are various types of finger chucks for holding works of a plurality of sizes, such as aluminum wheels, and for example, a "finger chuck" invented by the present applicant is disclosed in Japanese Utility Model Publication No. Sho 62-12487. The finger chuck is disclosed as shown in FIG.
A spider 10 is provided in the chuck body 1 so as to be movable in the same direction as the axis of the chuck body 1, and a sliding block 19 is slidably fitted in a radially elongated slot 13 of the chuck body 1 in the longitudinal direction. , The shaft holes 2 in their sliding blocks 19
0 and a female screw hole 21 are provided, and the claw shaft 2 is
3 and the rear end of the claw shaft 23 is
, And a feed screw shaft 29 rotatable from the outside of the chuck body 1 is screwed into the female screw hole 21.

Then, the slide block 19 is slid in the radial direction by the feed screw shaft 29, whereby each claw shaft 2 is moved.
3 is set to a desired position in the radial direction of the chuck main body 1, and then the spider 10 is moved to the front end, and the claw 2 of each claw shaft 23 is moved.
When the spider 10 is pulled backward by bringing the workpiece into contact with the chuck body 1 and the spider 10 is pulled rearward, the respective pawl shafts 23 slide and rotate rearward, and the respective pawls 22 face the center of the workpiece. The work was held between the chuck body 1 by moving the claw 22 backward. In addition, real public sho 64-3
Japanese Patent Application Laid-Open No. 606 discloses a technique corresponding to a plurality of types of workpieces by a rotation amount of a jaw and a receiving member as a "chuck capable of holding a plurality of types of objects".

[0004]

In the prior art described above, the former can set each claw shaft 23 at a desired position in the radial direction of the chuck main body 1, so that it can cope with a plurality of types of works having different outer diameters. Since the position adjustment of each claw shaft 23 is interlocking, it is not possible to chuck a deformed work. And a sliding block 1 for supporting the pawl shaft 23.
9 is not fastened to the chuck body 1,
In addition, the rigidity of the claw 22 is insufficient, and there is a problem that it is not suitable for high-speed rotation and high gripping force.

In the latter, the length of the jaw is determined by the corresponding minimum work, and when the jaw is lengthened, a large bending moment is generated at the connecting portion between the jaw and the drawbar, and the centrifugal force accompanying rotation is generated. There have been problems such as the jaw gripping force being reduced by the force, and the height of the end face of the stopper serving as a reference surface when the work is mounted being uneven.

Accordingly, an object of the present invention is to mount a plurality of types of workpieces such as a workpiece having a diameter difference and a workpiece having a different shape, prevent a generation of a bending moment, and prevent a reduction in gripping force due to insufficient rigidity, and perform high-speed rotation. And to provide a finger chuck suitable for high gripping force.

[0007]

According to a first aspect of the present invention, there is provided a finger chuck in which a plurality of jaw actuating drawbars are disposed in a chuck body in parallel with a rotation axis of the chuck body. In a finger chuck in which the drawbars are moved in the direction of the rotation axis by a spider and the work is held on the chuck body by a jaw at the tip of the drawbar, each of the drawbars is supported movably in the direction of the rotation axis by a bearing body. The body is individually attached to the chuck body so that the axis of the drawbar can be moved in the direction of the center of rotation of the chuck body and can be fixed at the moving position, and the spider is free from movement of the axis position of each drawbar. It is configured with a degree.

[0008]

[Function] When the axis of each drawbar is moved by the support so as to match the outer diameter of the workpiece to be machined, the spider allows the axis to move without interfering with the movement of the drawbar. Since the positions of the drawbars are adjusted, when the drawbars are pulled in the direction of the central axis by a spider, the workpiece is gripped by the chuck body by the jaws at the ends of the drawbars.
Therefore, by appropriately adjusting the position of each drawbar, one finger chuck can cope with several types of workpieces having different diameters, and can chuck workpieces having different shapes. Even when the outer diameter of the work is small, it is not necessary to lengthen the jaw simply by bringing the position of each drawbar close to the rotation axis of the chuck body, so a large bending moment is required at the joint between the jaw and the drawbar. Does not occur, and the jaw grasping force is prevented from lowering due to the centrifugal force accompanying the rotation. Furthermore, since the support body is integrally fixed to the chuck body, the rigidity of the drawbar and the jaw supported by the support body increases,
Suitable for high speed rotation and high gripping force.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a finger chuck according to the present invention will be described below with reference to the accompanying drawings. 1 is a plan view of the first embodiment, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is a partially enlarged view of FIG. ), A front body 1b fixed to the main body 1a by mounting bolts 2a, a central body 1c fixed to the front body 1b by mounting bolts 2b, and a mounting bolt to the main body 1a. 3 and a rear body 1d fixed by the rear body 3 and a central body 1c is formed in the rear body 1d.
The rear body 1d is fixed to the spindle 6 by a mounting bolt 5b via a spacer 4 fixed to the spindle 6 by a mounting bolt 5a.

A main body sleeve 7 is fixed to the front central portion of the center body 1c by a mounting bolt 7a, and a chuck body 8 of a centering chuck is fixed to the main body sleeve 7 by a mounting bolt 8a. The chuck body 8 is rotated integrally with the body 1. On the front surface of the chuck body 8, three claws 9 for gripping the center hole of the work W are slidably provided, and these claws 9 are similar to a well-known chuck.
It is oscillated by a draw rod 10 that moves back and forth by a rotating cylinder or the like (not shown). A draw member 11 is slidably fitted around the outer periphery of the central body 1c and the main body sleeve 7, and is prevented from rotating by a key 11a. A spherical seat is provided on the flange portion 11b of the draw member 11.

In a hollow chamber 1e formed in the body 1,
A substantially triangular spider 12 is stored. The center hole 12a of the spider 12 is rotatably and tiltably fitted to the flange 11b, and is prevented from coming off by a retaining plate 11c fixed to the flange 11b. Further, the spider 12 is formed with a radially extending long hole 12b at a position where the circumference of the chuck rotation axis X is equally divided into three (two or four in the case of two claws or four claws, respectively). Have been. A draw sleeve 13 is screwed onto the rear end portion 11d of the draw member 11, and the spider 12 moves forward and backward in accordance with the forward and backward movement of the draw sleeve 13 operated by a rotating cylinder (not shown) or the like (not shown). It has become.

Further, each fitting long hole 12b of the spider 12
The front body 1b opposing the front end is provided with a fitting hole 14, and the fitting hole 14 is provided with a bush 1 as a support body.
5 are fitted rotatably.
The bush 15 has a plate fitting portion 15b which is eccentric with respect to the mounting fitting portion 15a.
The center hole 16a of the jaw support plate 16 is rotatably fitted to 5b. Flange 15c of bush 15
Is detachably fixed to the front body 1b by a fixing screw 17 together with the jaw supporting plate 16 in a superposed state. The fixing screw 17 penetrates through the mounting holes 16b and 15d of the jaw support plate 16 and the flange portion 15c and is screwed into the screw hole 1f of the front body 1b. Further, the bush 15 has a drawbar holding hole 18 parallel to the chuck rotation axis X so as to be concentric with the axis of the plate fitting portion 15b, that is, eccentric with respect to the mounting fitting portion 15a. Is formed.

A draw bar 20 for operating a jaw, which has a jaw 19 at its tip end, is slidably fitted in the draw bar holding hole 18 in the axial direction as described later.
A work receiver 21 having a semicircular surface is attached to the jaw support plate 16 by an attachment bolt 22, and a pair of jaw support arms 16 c are integrally protruded.
The rear end of the draw bar 20 is reduced in diameter, and the reduced diameter portion 20a is movably fitted in the long fitting hole 12b of the spider 12 formed to face each fitting hole 14 in the longitudinal direction. It is inserted and furthermore is prevented by a washer 23 and a nut 24. Accordingly, in a state where the fixing screw 17 is removed and the mounting fitting portion 15a of the bush 15 is disengaged from the fitting hole 14, the draw bar 20 is moved in the fitting long hole 12b to rotate the bush 15 to rotate the body 1. By moving the bush 15 by 180 degrees about the draw bar 20 at that position, the mounting fitting portion 15a of the bush 15 can be moved.
Can be fitted into the fitting hole 14 again.

The jaw support plate 16 can rotate about the plate fitting portion 15b, so that the bush 15
Support plate 1 even when the plate is rotated 180 degrees.
6 can be kept in the original state, and in this state, the mounting holes 16b are formed in the flange portion 15c and the front body 1b.
A mounting hole (also used as the mounting hole 15d) and a screw hole 1f are formed at positions opposite to the above.

The jaw 19 is rotatably mounted on a tip end of the draw bar 20 by a support pin 25, and an intermediate portion thereof has a support pin 26 extending in a direction intersecting the radius of the body 1.
Thus, it is rotatably attached to the pair of jaw support arms 16c. The jaw 19 includes a jaw main body 19a and a jaw piece 19b detachably attached to a tip of the jaw main body 19a by an attachment bolt 27.
The jaw piece 19b is replaced with a new consumable,
The jaw main body 19a can be replaced with an appropriate one according to the shape of the work. The jaw 19 may be fixed to the draw bar 20 by welding or the like.

In order to grasp a work using the finger chuck configured as described above, first, the draw sleeve 13 is moved forward by a rotating cylinder (not shown) or the like to move the spider 12 to the forward end. Since each draw bar 20 moves forward and the jaw 19 opens outward as shown by the imaginary line in the figure, the work W is placed on the work receiver 21, and in this state, the draw rod 10 is moved backward by a rotating cylinder (not shown). The three claws 9 swing outward to hold the peripheral edge of the center hole of the work W. Next, when the draw sleeve 13 is retracted by a rotary cylinder (not shown) or the like and the spider 12 is pulled, the draw bar 20 is retracted, the jaw 19 rotates inward with the support pin 26 as a rotation support shaft, and the jaw piece 19b is rotated. The work W is gripped. In this state, the spindle 6 is rotated, and the work W is processed together with the body 1 by rotating the work W.

[0017] Next, when to be'll grip the smaller diameter of the workpiece W ₁ than in the previous case, when advancing the spider 12 on the back front body 1b to the most advanced end abutting, drawbar 20 and jaws 19 are advanced Therefore, a space is provided in front of the jaw support plate 16 so that the fixing screw 17
Is removed from the front body 1b so that the drawbar 20 can be moved in the direction of the rotation center of the body 1 using the fitting long hole 12b as described above.

Now, only the bush 15 is moved from the position shown in FIG.
Rotate the fitting fitting 15a again by 80 degrees to fit the fitting hole 14a again.
, The axis position of the draw bar 20 approaches the chuck rotation axis X as much as possible due to eccentricity, and the distance from the chuck rotation axis X to the axis position of the draw bar 20 is minimized. In this state, the jaw supporting plate 16
Mounting hole 16b of the flange portion 15c.
d and the screw hole 1f of the front body 1b. In this state, when the fixing screw 17 is inserted into the mounting hole 16b and screwed into the screw hole 1f, and the bush 15 is again fixed to the front body 1b together with the jaw supporting plate 16, as shown in FIGS. , Work W having a smaller diameter than work W shown in FIG.
₁ can be gripped.

When the bush 15 is rotated left and right by 180 degrees or less, the position of the axis of the draw bar 20 moves in the radial direction of the body 1, for example, as shown in FIG. It is located at an intermediate position between about 180 degrees, so that the mounting hole 15d of the flange portion 15c and the front body 1
By increasing the number of screw holes 1f of b, the axial center position of the drawbar 20 can be changed in multiple stages. Therefore, by appropriately adjusting and using the axial position of the draw bar 20 according to the shape of the workpiece, there is no need to prepare and replace the jaws of various sizes each time. Can be easily adapted to work. When the shape of the long fitting hole 12 b of the spider 12 is formed in a semicircular shape centered on the center line of the fitting hole 14, the mounting fitting portion 15 a of the bush 15 is formed inside the fitting hole 14. It is convenient because it can rotate. In addition, instead of the centering chuck, the body 1
May be used.

As described above, since the position of the axis of each draw bar 20 can be appropriately moved, it is possible to grip a workpiece having a different diameter and a workpiece having a different shape, and it is necessary to lengthen the jaw even when gripping a workpiece having a small diameter. Since there is no jaw, it is possible to prevent a decrease in gripping force due to deformation of the jaw. Further, since the bush 15 as a support for supporting the drawbar 20 is integrally fixed to the body 1 by the fixing screw 17, there is no backlash between the bush 15 and the body 1, and their rigidity can be kept high. It is suitable for high-speed rotation and high gripping force.

FIG. 6 shows a first modified embodiment of the present invention.
Is a partially cut-away longitudinal sectional view of a finger chuck in which the shape and mounting position of the jaw 19 are changed. And FIG.
FIG. 6 shows a state in which the bush 15 of the finger chuck shown in FIG. 6 is rotated by 180 degrees from the initial position to bring the axis of the draw bar 20 closer to the chuck rotation axis X. The jaw 19 is indicated by a two-dot chain line. The work with the indicated diameter can be gripped.

FIGS. 8 and 9 show a second modification of the present invention. The same components and parts as those in FIGS. 2 and 3 are denoted by the same reference numerals, and their description is omitted. A long sliding hole 31a is formed in the front surface of the body 1, and a fitting portion 32a of the bush 32 is slidably fitted in the long sliding hole 31a. A rack plate 33 is fixed to the front surface of the body 1, and rack teeth formed on the flange portion 32 b of the bush 32 mesh with the rack of the rack plate 33. Further, a groove 31b for moving the mounting bolt 34 is formed in the body 1. Flange part 32b of the bush 32
Are the mounting bolt 34 and the nut 3 together with the work receiver 21.
5, the draw bar 20 is inserted into the bush 32 so as to be slidable in the axial direction, the rotation is restricted by the cam pin 36 and the cam groove 20 b, and the draw bar 20 is moved forward and backward by the draw bar 20. Rotates. The work receiver 21 is provided with a bolt operation hole 21a. The jaw 19 is fixedly attached to the tip of the draw bar 20 by an attachment bolt 37.

When grasping a workpiece using the finger chuck configured as described above, first, the spider 12 is moved to the forward end, each draw bar 20 is advanced, and the jaw 19 is advanced and rotated. When the work W is placed on the work receiver 21 and then the spider 12 is pulled by a rotating cylinder (not shown) or the like, the draw bar 20 is retracted, and the jaw 19 is pulled backward, so that the work W
To grip.

Next, when trying to grip a work having a smaller diameter than the above-mentioned case, the mounting bolt 34 is loosened to release the engagement between the bush 32 and the rack plate 33, and the bush 32 is chucked according to the diameter of the work. By appropriately moving in the radial direction of the rotation axis X, the position of the axis of the draw bar 20 also moves. Thereafter, the rack teeth of the bush 32 and the rack of the rack plate 33 are engaged again, and the bush 32 is fixed to the body 1 with the mounting bolts 34, and the small-diameter work is gripped in the manner described above. Since it is configured and operated as described above, it has substantially the same effects as the first embodiment.

FIG. 10 shows a third modified embodiment of the present invention. The same components and components as those in FIGS. 8 and 9 are denoted by the same reference numerals, and their description and illustration are omitted. A slider 41 as a support body is attached to the body 1 with mounting bolts 34.
The draw bar 20 is inserted into the slider 41 so as to be slidable in the axial direction, and a work receiver 21 is attached to the front part. A jaw 19 is fixedly attached to the tip of the draw bar 20. A dovetail groove 42 and a dovetail 43 are slidably provided between the front surface of the body 1 and the rear portion of the slider 41, respectively.

The procedure for gripping the work with this finger chuck is the same as in each of the above embodiments, except that the draw bar 20 is used.
In order to hold the work of different diameter by moving the axial position of the work, it is preferable to loosen the mounting bolt 34 and slide the slider 41 as appropriate according to the diameter of the work to be held. Since it is configured and operated as described above, it has substantially the same effects as the first embodiment.

The structure of moving the slider 41 to move the axial center position of the draw bar 20 may be a serration, a key groove, a pin hole, or the like, in addition to the long hole and the dovetail groove in each of the above embodiments. In short, the structure and function of the present invention can be appropriately changed without departing from the purpose and spirit of the present invention.

[0028]

As described in detail above, according to the present invention,
Since the axis position of each drawbar can be moved as needed, there is no need to prepare jaws of various sizes, it is easy to change the setup, and it is possible to grip not only works with different diameters but also works with irregular shapes. In addition, since it is not necessary to lengthen the jaw when gripping a small-diameter work, it is possible to prevent a decrease in gripping force due to a bending moment. Furthermore, since the support that supports the drawbar is integrally fixed to the chuck body with mounting bolts, there is no backlash between the support and the body, and their rigidity can be kept high, making them suitable for high-speed rotation and high gripping force. However, its practical value is great.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a partially enlarged view of FIG. 1;

FIG. 5 is an explanatory diagram showing a state in which the bush is rotated 90 degrees to move the position of the axis of the draw bar.

FIG. 6 is a longitudinal sectional view with a part broken away of a first modified embodiment of the present invention.

FIG. 7 is an explanatory view showing a state in which the bush in FIG. 6 is rotated by 180 degrees to move the axial position of the draw bar.

FIG. 8 is a longitudinal sectional view with a part broken away of a second modified embodiment of the present invention.

9 is a vertical sectional view of a main part of FIG.

FIG. 10 is a longitudinal sectional view of a main part of a third modified example of the present invention.

FIG. 11 is a longitudinal sectional view, partially broken away, showing a conventional example.

[Explanation of symbols]

1. ・ Chuck body, 12 ・ Spider, 15 ・ ・
Bush (support body), 17-fixing screw, 19-jow, 20-drawbar, W-work, X-chuck rotation axis.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23B 31/10 B23B 31/16 B23B 31/18 B23B 31/36

Claims (1)

(57) [Claims] 1. A plurality of drawbars for operating a jaw are disposed in a chuck body in parallel with a rotation axis of the chuck body, and the drawbars are moved in a direction of the rotation axis by a spider, and a workpiece is chucked by a jaw at a tip of the drawbar. In a finger chuck to be gripped by a body, each of the drawbars is movably supported in a rotation axis direction by a support body, and each of the support bodies is movably moved along the axis of the drawbar in the direction of the rotation center of the chuck body. A finger chuck, wherein the spider is individually attached to the chuck body so as to be fixable, and the spider has a degree of freedom with respect to the movement of the axial center position of each drawbar.