JPH0750086Y2 - Chuck - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck in which a plurality of tightening claws are detachably attached and replaced in the radial direction.

[0002]

2. Description of the Related Art Conventionally, as a chuck of this type, for example, a technique disclosed in Japanese Patent Publication No. 63-15085 is known. Here, a master jaw and a base jaw with a top jaw are mounted on a chuck body so as to be slidable in the radial direction in a state of facing each other. A rack is formed on the back surface of the base jaw, and a mating member that meshes with the rack is provided on the master jaw so as to be movable in the axial direction by an operation pin. When the claws are operated, the wedge member of the master jaw is fitted in the wedge groove of the wedge member, and the wedge member is moved in the axial direction while the meshing member is meshed with the rack of the base jaw. Along with the movement, the base jaw with top jaw is moved inward in the radial direction. When replacing the claws, the operating pin retracts the engaging member to disengage it from the base jaws, and the base jaws with top jaws are replaced in the radial direction.

[0003]

However, according to the conventional chuck, since the master jaw and the base jaw with the top jaw are integrated by the meshing member provided with the rack, a rack machining error may cause an error after the replacement. The position of the base jaw in the radial direction may be slightly displaced from the master jaw, which may reduce the accuracy of gripping the top jaw with respect to the workpiece. Further, since the top jaw is attached to the base jaw that meshes with the master jaw, there is a problem that the mass of the entire fastening claw is increased and the gripping force is reduced due to centrifugal force. Therefore, an object of the present invention is to provide a chuck that can improve the gripping accuracy and reduce the reduction of the gripping force during rotation.

[0004]

In order to solve the above-mentioned problems, the chuck of the present invention has a plurality of tightening claws provided with wedge portions movably mounted in the chuck body in the radial direction, and each tightening is performed. A wedge member having a meshing portion that meshes with the wedge portion of the claw is provided movably in the axial direction, and a sliding member having a wedge portion that meshes with the meshing portion of the wedge member is provided on the rear surface side of each tightening claw in the radial direction. Slidably mounted on the back side of the tightening claw,
The sliding member is provided with an operation mechanism that supports a retaining member that engages with the retaining hole and restricts the movement of the tightening claw to the chuck outer peripheral side, and that engages and disengages the retaining member with respect to the retaining hole. A restricting member that restricts the movement of the tightening claw toward the chuck center when the member is disengaged from the tightening claw is provided, and the chip escape hole is connected to the chip escape portion located closer to the chuck outer circumference than the removal preventing member. Set up and configured.

[0005]

In the chuck of the present invention, the engaging claw of the wedge member is disengaged from the wedge part of the tightening claw, and the retaining claw is disengaged from the retaining hole by the operating mechanism. It is removed and replaced. After the pawl is replaced, the retaining member engages with the retaining hole to restrict the movement of the tightening pawl to the chuck outer peripheral side, and the restricting member restricts the movement of the clamping pawl to the chuck center side. Therefore, it is possible to accurately position each tightening claw at a predetermined radial position and improve the gripping accuracy for the workpiece. Even if fine chips enter the removal hole, the chips are blown off by the centrifugal force to the chip escape area on the outer circumference of the chuck than the removal member.Therefore, there is a gap between the removal hole and the removal member. There is no risk of powder clogging. As a result, it is possible to prevent the phenomenon in which the centrifugal force generated in the sliding member is directly transmitted to the tightening claw via the cutting chips and the gripping force of the tightening claw is reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention is shown in FIG.
~ It demonstrates based on FIG. As shown in FIG. 1, in the chuck of this embodiment, a plurality of tightening claws 2 (only one is shown) are attached to the front part of a chuck body 1. Each tightening claw 2 is composed of a master jaw 3 housed inside the chuck body 1 and a top jaw 4 protruding forward of the chuck body 1. The top jaw 4 is connected to the master jaw 3 by a bolt 5. There is. Master Joe 3
Convex portions 6 that fit into guide grooves (not shown) of the chuck body 1 are formed on both side surfaces of the chuck body 1, whereby the tightening claws 2 are attached to the chuck body 1 so as to be movable in the radial direction. A wedge portion 7 having a T-shaped cross section is provided at the inner ends of both side surfaces of the master jaw 3, and a retaining hole 8 is formed on the back surface of the master jaw 3.

A wedge member 10 is inserted into a sliding hole 9 formed at the center of the chuck body 1 so as to be movable in the axial direction of the chuck body 1. Chuck body 1
A pilot plate 11 is fixed to the front surface of the, and its boss portion 12 is inserted into the center hole 13 of the wedge member 10. The master jaw 3 is provided on the outer peripheral portion of the wedge member 10.
A wedge groove 14 is formed as a meshing portion that meshes with the wedge portion 7, and a cylindrical portion 15 is projectingly provided on the rear portion. A draw tube 16 is connected to the tubular portion 15, and the wedge member 10 is moved back and forth between the meshing position and the disengaging position via the draw tube 16 by a cylinder (not shown). It should be noted that chamfers 7a and 14a are provided at the rear end of the wedge portion 7 and the front end of the wedge groove 14 so that they can mesh smoothly.

A sliding member 17 is mounted on the chuck body 1 on the back side of each tightening claw 2 so as to be slidable in the radial direction while being joined to the back surface of the master jaw 3. A wedge portion 18 having the same inclination angle as the wedge portion 7 of the tightening claw 2 is projectingly provided on the outer surface of the inner end portion of the sliding member 17. Then, the wedge portion 18 meshes with the wedge portion 7 of the tightening claw 2 in the wedge groove 14 of the wedge member 10, and as the wedge member 10 moves back and forth, the tightening claw 2 and the sliding member 17 are integrated in the radial direction. When the wedge member 10 reaches the disengaged position while being moved to, the wedge portion 7 of the tightening claw 2 is the wedge groove 1 of the wedge member 10.
It is designed to be dissociated from 4.

A guide hole 19 is axially formed in the central portion of the sliding member 17, and the guide hole 19 engages with the retaining hole 8 of the tightening claw 2 and the chuck claw 2 has a chuck outer peripheral side. A retaining member 20 that restricts the movement to the slide is inserted slidably. The retaining member 20 has a chamfer 20a at the front end and a V groove 21 at the rear end. The sliding member 17 is provided with a notch ball 22 that fits into the V groove 21 and a spring 23 that urges the notch ball 22, and the engagement of the V groove 21 and the notch ball 22 causes the retaining member 20 to engage with the retaining hole 8. It is held in a matching position. As shown in FIGS. 2 and 3, a chip escape portion 24, which is located on the outer peripheral side of the chuck with respect to the retaining member 20, is continuously provided in the retaining hole 8 in a shape including a curved surface which gradually becomes shallower toward the outer side in the radial direction. ing. Further, a chip discharge groove 25 is formed on the back surface of the master jaw 3 so as to extend from the chip escape portion 24 to the outer peripheral surface of the chuck. The chip discharge groove 25 is not necessary when the gap between the master jaw 3 and the tightening claw 2 is large.

A positioning pin 26 is provided on the rear surface of the master jaw 3 on the side of the chip discharging groove 25, while a regulation groove 27 into which the positioning pin 26 is fitted is chucked on the front surface of the sliding member 17. It is formed so as to open to the outer peripheral surface. The positioning pin 26 and the restriction groove 27 constitute a restriction member, and when the wedge member 10 is disengaged from the tightening claw 2, the inner end surface of the restriction groove 27 has the positioning pin 26.
In response to this, the movement of the tightening claw 2 toward the chuck center side is restricted. The positioning pin 26 may be provided on the sliding member 17 side and the regulation groove 27 may be provided on the master jaw 3 side to form the regulation member. However, the regulation groove 27 discharges the chips invading there by centrifugal force. It is preferable to provide it on the sliding member 17 side so that it can be performed. In addition, a small gap is provided between the retaining hole 8 and the retaining member 20 and between the positioning pin 26 and the inner end surface of the regulating groove 27 so that the tightening claw 2 and the wedge member 10 engage with each other with a slight play. Since the a and b (see FIG. 3) are provided, it is not necessary to design the retaining hole 8 and the retaining member 20 concentrically.

As shown in FIG. 1, an insertion hole 28 is formed in the sliding member 17 so as to open to the outer peripheral surface of the chuck, and a push pin 29 is inserted into the insertion hole 28 so as to be slidable in the radial direction. Has been done. On the outer peripheral surface of the push pin 29, a cam groove 31 that engages with the pin 30 protruding from the retaining member 20 is obliquely formed, and by pushing down the push pin 29, the retaining member 20 is disengaged from the retaining hole 8. To be done. A back plate 32 and a draw plate 33 are arranged at the rear portion of the chuck body 1, and a spring 34 for urging the draw plate 33 forward is interposed between the back plate 32 and the draw plate 33. When the wedge member 10 is retracted, the draw plate 3
3 is pushed rearward by the wedge member 10 and separated from the retaining member 20. When the wedge member 10 moves forward,
The draw plate 33 is moved forward by the urging force of the spring 34, and is pushed by the urging force of the spring 34 so that the retaining member 20 is retained in the retaining hole 8
Is engaged with. Therefore, the push pin 29 and the draw plate 33 constitute the operation mechanism of this embodiment. Reference numeral 35 is a bolt for attaching the chuck to a spindle of a machine tool (not shown).

Next, the operation of the chuck of this embodiment constructed as described above will be described. FIG. 1 shows a usage state of the chuck, in which the wedge member 10 is arranged at the meshing position, and the wedge groove 14 of the wedge member 10 is arranged in the clamping claw 2 and the sliding member 17.
The draw plate 33 is brought into pressure contact with the retaining member 20 by the urging force of the spring 34, whereby the retaining member 20 is engaged with the retaining hole 8.
In this state, when the wedge member 10 slides back and forth,
By the wedge action of the wedge groove 14 and the wedge portions 7 and 18, both the fastening claws 2 and the sliding members 17 are simultaneously opened and closed in the radial direction of the chuck body 1, and the top jaws 4 of the respective fastening claws 2 are moved. A workpiece (not shown) is attached and detached. In this case, since the wedge portion 7 of the tightening claw 2 meshes with the wedge groove 14 of the wedge member 10, the accuracy of grasping the workpiece can be maintained.

When fine chips such as casting powder enter the retaining hole 8 as the workpiece is machined, the chips are blown off by the centrifugal force to the chip escape portion 24, and the chip discharge groove 25 is ejected from there. And is discharged to the outside of the chuck. For this reason, there is no possibility that cutting chips will be clogged between the retaining hole 8 and the retaining member 20, and the centrifugal force generated in the sliding member 17 is directly transmitted to the tightening claw 2 through the chip, and the clamping claw 2 is gripped. It is possible to prevent the phenomenon that the power is reduced. Therefore, an expensive dustproof device such as a chuck cover, a dust seal or an air purge is unnecessary.
Although the centrifugal force generated in the sliding member 17 is transmitted to the wedge member 10 via the wedge portion 18 and the wedge groove 14, the centrifugal force is greatly attenuated by the wedge action and the wedge member 1
Since it is a small value compared with the urging force of the cylinder that drives 0, there is no possibility that the wedge member 10 will be moved by the centrifugal force.

When the tightening claw 2 is to be replaced according to the diameter of the workpiece, the draw tube 16 is used in the state shown in FIG.
The wedge member 10 is retracted by the wedge groove 14 and the wedge portions 7 and 18 are engaged with each other to simultaneously close and move the tightening claws 2 and the sliding members 17, and the wedge member 10 causes the draw plate 33 to move backward. Push-out prevention member 20
Away from. When the wedge member 10 reaches the retracted end position, each tightening claw 2 is completely disengaged from the wedge member 10, but the engagement of the retaining member 20 and the retaining hole 8 causes the clamping claw 2 to move toward the chuck outer peripheral side. Because movement is regulated,
Each tightening claw 2 is securely held on the chuck body 1 without falling off. When the push pin 29 is pushed down in this state, the retaining member 20 is retracted from the retaining hole 8 via the pin 30 and the cam groove 31, and the fastening claw 2 is disengaged from the chuck body 1. Therefore, the fastening claw 2 can be moved to the outer side in the radial direction and removed from the chuck body 1, and a new fastening claw 2 can be inserted to the inner side in the radial direction and mounted on the chuck body 1. In this case, the regulation groove 27 receives the positioning pin 26 to regulate the movement of the fastening claw 2 toward the chuck center side, and accurately positions the fastening claw 2 at the position where the retaining hole 8 faces the retaining member 20.

When a new tightening claw 2 is installed, then,
The wedge member 10 is advanced, and the draw plate 33 is moved forward by the spring 34. Then, the draw-out prevention member 20 is pushed by the draw plate 33 and
, Whereby a new clamping pawl 2 is joined to the chuck body 1. After that, the chuck body 1 is rotated and the next tightening claw 2 is indexed to the working position. Therefore, if the remaining tightening claws 2 are sequentially replaced in the same procedure as described above, the claw replacement work is completed and the chuck is ready for use. After the claws are replaced, the retaining member 20 engages with the retaining holes 8 in all the clamping claws 2 to restrict the movement of the clamping claws 2 to the chuck outer peripheral side.

Next, another embodiment of the present invention will be described.
In the embodiment shown in FIG. 4, the restricting member is constituted by the boss portion 12 of the pilot plate 11, and when the fastening claw 2 is disengaged from the wedge member 13, the boss portion 12 receives the inner end surface of the fastening claw 2. The movement inward in the radial direction is restricted. A minute gap c is provided between the boss portion 12 and the inner end surface of the tightening claw 2 so that the tightening claw 2 and the wedge member 10 can be engaged with each other with some play.

In the embodiment shown in FIGS. 5 and 6, the master jog 3 has a lightening hole 36 for reducing its weight.
Are provided so as to open on the outer peripheral surface of the chuck. A chip escape portion 24 is obliquely connected to the retaining hole 8 so as to be located closer to the chuck outer circumference than the retaining member 20, and the retaining hole 8 is connected to the weight-reducing hole 36 via the chip releasing portion 24. Has been done. The fine chips that have entered the retaining hole 8 are blown off by the centrifugal force to the chip escape portion 24, and then discharged from the chuck through the weight reduction hole 36. According to this, the chips can be surely discharged by utilizing the weight-reducing holes 36.

In the embodiment of FIGS. 7 and 8, the retaining hole 8 is formed on the back surface of the master jaw 3 in the shape of an elongated hole extending in the radial direction, and a part thereof, that is, on the chuck outer peripheral side of the retaining member 20. The chip escape portion 24 is continuously provided at the position where it is located. Also in this case, the cutting chips are blown off by the centrifugal force to the cutting chip escape portion 24 and are separated from the retaining member 20, so that there is no possibility that the cutting chips are clogged between the retaining holes 8 and the retaining member 20. The eccentric pin 37, which constitutes the operation mechanism, is rotatably inserted into the insertion hole 28 of the sliding member 17 and is prevented from coming off by the pressing plate 38. The eccentric pin 37 is a wrench (not shown).
Insertion hole 39 for inserting and removing the peripheral groove 40 of the retaining member 20
And an eccentric projection 41 that fits in with the eccentric projection 41. The eccentric projection 41 is configured to be rotated by a wrench to engage and disengage the retaining member 20 with respect to the retaining hole 8. The sliding member 17 is provided with a steel ball 42 and a spring 43 that regulate the rotation of the eccentric pin 37. The wedge member 10 is attached to the draw screw 46 via a screw sleeve 44 and a retaining ring 45. Other configurations and operations and the claw replacement procedure are the same as those in the above embodiment.

The present invention is not limited to the configuration of each of the above-described embodiments. For example, a wedge bar moved by a plunger is used as the wedge member, or the wedge member 10 and the draw plate 33 are formed by a parent-child cylinder. Each of them is driven separately, the wedge member 10 and the draw plate 33 are integrally formed, the shapes of the retaining hole 8, the retaining member 20 and the chip escape portion 24 are appropriately changed, and the push pin 29 and the eccentric pin 37 are used. Is configured to operate by the robot arm of the pawl exchanging device so as to automatically exchange each clamping pawl 2 and the like, and is embodied by arbitrarily changing the shape and configuration of each part without departing from the spirit of the present invention. It is also possible to do so.

[0020]

As described above in detail, according to the present invention, even in the case of exchanging the claws, the wedge part of the tightening claw is meshed with the meshing part of the wedge member, so that the workpiece can be replaced. The accuracy of grasping the tightening claw can be maintained. Also, since the entire tightening claw is replaced, the conventional base jaw can be omitted,
The reduction in gripping force due to centrifugal force can be reduced. Further, the retaining member engages with the retaining hole to restrict the movement of the tightening claw to the chuck outer peripheral side, and the restricting member restricts the movement of the tightening claw to the chuck center side. It can be securely engaged with the wedge part of the tightening claw to ensure the claw replacement.
Also, since the chips that have entered the retaining holes are blown off by the centrifugal force to the chip escape portion, there is no risk of the chips getting stuck between the retaining holes and the retaining member, and the centrifugal force of the sliding member tightens the clamping claws. It is possible to prevent the phenomenon that the gripping force of the is reduced.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a chip escape portion of a tightening claw in the chuck of FIG.

FIG. 3 is a rear view of the tightening claw of FIG.

FIG. 4 is a rear view of the vicinity of the tightening claw showing another configuration of the restriction member.

FIG. 5 is a cross-sectional view showing another example of the chip escape portion of the tightening claw.

FIG. 6 is a rear view of the tightening claw of FIG.

FIG. 7 is a sectional view of a chuck showing another embodiment of the present invention.

FIG. 8 is a plan view of FIG.

[Explanation of symbols]

1 ・ ・ Chuck body 2 ・ ・ Tightening claws 3 ・ ・ Master jaws 4 ・ ・ Top jaws 7 ・ ・ Wedges 8 ・ ・ Retaining holes 10 ・ ・ Wedge members 11 ..Boss portions, 14 ... Wedge grooves, 16 ... Draw tubes, 17 ... Sliding members, 20 ...
・ Notch ball, 24 ・ ・ Chip escape section, 25 ・ ・ Chip discharging groove, 26 ・ ・ Positioning pin, 27 ・ ・ Regulating groove, 29 ・
・ Push pin, 31 ・ ・ Cam groove, 32 ・ ・ Back plate, 33 ・ ・ Draw plate, 34 ・ ・ Spring,
36 ・ ・ Lightweight hole, 37 ・ ・ Eccentric pin, 41 ・ ・ Eccentric projection, 46 ・ ・ Draw screw.

Claims (1)

[Scope of utility model registration request] 1. A plurality of tightening claws having wedges are mounted on a chuck body so as to be movable in a radial direction, and a wedge member having a meshing part that meshes with the wedges of each tightening claw is moved in the axial direction. A sliding member, which is freely provided and has a wedge portion that meshes with the meshing portion of the wedge member, is mounted on the back side of each tightening claw so as to be slidable in the radial direction, and a retaining hole is formed on the back side of the tightening claw. The slide member is provided with an operation mechanism that engages with the retaining hole and supports the retaining member that restricts the movement of the tightening claw to the chuck outer peripheral side, and that engages and disengages the retaining member with respect to the retaining hole. , A regulating member for regulating the movement of the clamping claw toward the chuck center side when the wedge member is disengaged from the clamping claw is provided, and the chip escape hole located in the outer peripheral side of the chuck with respect to the retaining hole in the retaining hole. A chuck characterized in that it is formed by arranging.