JPH0539809U - Check - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the gripping accuracy and prevent the gripping force from decreasing in the chuck in which the clamping claws are replaced in the radial direction. [Structure] The tightening claw 2 and the wedge portions 7 and 18 of the sliding member 17 are engaged with the wedge groove 14 of the wedge member 10. A retaining hole 8 is formed on the back surface of the tightening claw 2, and a sliding member 17 is provided with a retaining member 20 which can be engaged with and disengaged from the retaining hole 8 and a push pin 29 which is disengaged from the retaining hole 8. The draw plate 33 engages the retaining member 20 with the retaining hole 8 to restrict the movement of the fastening claw 2 inward in the radial direction. Wedge member 10 is tightening claw 2
When it is disengaged from, the restriction groove 27 of the sliding member 17 receives the positioning pin 26 of the tightening claw 2 and restricts the movement of the tightening claw 2 to the chuck center side. A chip escape section 24 is continuously provided on the outer peripheral side of the chuck of the retaining hole 8, and the chip is shaken off and discharged to the outside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a chuck in which a plurality of tightening claws are detached and replaced in the radial direction.

[0002]

[Prior Art]

 Conventionally, as this type of chuck, 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 operating the claws, 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 to slide the master jaw. Along with the movement, the base jaw with top jaw is moved inward in the radial direction. When the pawl is replaced, the engaging member is retracted by the operation pin and disengaged from the base jaw, and the base jaw with the top jaw is replaced in the radial direction.

[0003]

[Problems to be solved by the device]

 However, according to the conventional chuck, the master jaw and the base jaw with the top jaw are integrated by the meshing member with the rack, so that the rack jaw is erroneously processed and the base jaw after the replacement has a radial direction with respect to the master jaw. The position may be slightly displaced, which may reduce the accuracy of gripping the top jaw with respect to the workpiece. Also, since the top jaw is attached to the base jaw that meshes with the master jaw, the mass of the entire clamping claw becomes large, and there is a problem that the gripping force decreases due to centrifugal force. Therefore, an object of the present invention is to provide a chuck that can improve the gripping accuracy and can reduce the reduction in gripping force during rotation.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the chuck of the present invention has a plurality of tightening claws provided with wedge portions mounted on a chuck body so as to be movable in the radial direction, and engaging parts that mesh with the wedge parts of each tightening claw. A wedge member provided with is provided so as to be movable in the axial direction, and a sliding member having a wedge portion that meshes with the engaging portion of the wedge member is attached to the back side of each tightening claw so as to be slidable in the radial direction and tightened. A retaining hole is formed on the back surface of the attachment claw, and the sliding member supports a retaining member that engages with the retaining hole and regulates the movement of the tightening claw to the outer circumference of the chuck. An operation mechanism that engages and disengages with the wedge is provided, and a restricting member that restricts the movement of the clamping claw toward the center of the chuck when the wedge member disengages from the clamping claw is provided. Is also formed by continuously arranging chip escape portions located on the outer peripheral side of the chuck.

[0005]

[Action]

 In the chuck of this invention, the engagement claw of the wedge member is disengaged from the wedge part of the tightening claw, and the tightening claw is removed from the chuck body in the radial direction with the retaining member disengaged from the retaining hole by the operation mechanism. Will be exchanged. After the pawl is replaced, the retaining member engages with the retaining hole to restrict the movement of the tightening pawl toward the outer circumference of the chuck, and the restricting member restricts the movement of the clamping pawl toward the chuck center. Therefore, it is possible to accurately position each tightening claw at a predetermined radial position and improve the gripping accuracy for the workpiece. In addition, even if fine chips enter the retaining hole, the chips will be blown by the centrifugal force to the chip escape area on the outer periphery of the chuck than the retaining member, so there will be a gap between the retaining hole and the retaining member. There is no risk of powder clogging. As a result, it is possible to prevent the centrifugal force generated in the sliding member from being directly transmitted to the tightening claw via the cutting chips and the gripping force of the tightening claw being reduced.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 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 the 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 bolts 5. Has been done. On both side surfaces of the master jaw 3, there are formed convex portions 6 that fit into guide grooves (not shown) 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. Has been done. A wedge portion 7 having a T-shaped cross section is provided at the inner end portions 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 in the central portion of the chuck body 1 so as to be movable in the axial direction of the chuck body 1. A pilot plate 11 is fixed to the front surface of the chuck body 1, and a boss portion 12 of the pilot plate 11 is inserted into a central hole 13 of the wedge member 10. A wedge groove 14 is formed on the outer peripheral portion of the wedge member 10 as a meshing portion that meshes with the wedge portion 7 of the master jaw 3, and a cylindrical portion 15 is provided on the rear portion of the wedge groove 14. A draw tube 16 is coupled to the cylindrical 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 rear surface side of each tightening claw 2 so as to be slidable in the radial direction in a state of being joined to the rear surface of the master jaw 3. On the outer surface of the inner end portion of the sliding member 17, a wedge portion 18 having the same inclination angle as the wedge portion 7 of the tightening claw 2 is provided so as to project. 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, only the wedge portion 7 of the tightening claw 2 is disengaged from the wedge groove 14 of the wedge member 10.

A guide hole 19 is axially provided in the central portion of the sliding member 17, and the guide hole 19 engages with the retaining hole 8 of the tightening pawl 2 and the chuck outer peripheral side of the tightening pawl 2. The 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. By fitting the V groove 21 and the notch ball 22, the retaining member 20 is inserted into the retaining hole 8. It is held in the engaged position. As shown in FIGS. 2 and 3, the removal prevention hole 8 has a shape including a curved surface where the chip escape portion 24 located on the outer circumferential side of the chuck with respect to the removal prevention member 20 is gradually shallowed outward in the radial direction. It is lined up. 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 at the side of the chip discharge groove 25, while a regulation groove 27 into which the positioning pin 26 is fitted is provided on the front surface of the sliding member 17. It is formed so as to open on the outer peripheral surface of the chuck. When the wedge member 10 is disengaged from the fastening claw 2, the inner end surface of the regulation groove 27 receives the positioning pin 26 and the chuck center of the fastening claw 2 is formed. The movement to the side is regulated. 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. It is preferable to provide it on the sliding member 17 side so that it can be discharged. In addition, 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 minute gaps 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 on 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. When the push pin 29 is pushed down, the retaining member 20 is prevented from moving into the retaining hole 8. Dissociated from. A back plate 32 and a draw plate 33 are arranged at the rear 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 33 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 this, so that the retaining member 20 is engaged with the retaining hole 8. 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 configured as described above will be described. FIG. 1 shows a state in which the chuck is used. At this time, the wedge member 10 is arranged at the meshing position, and the wedge groove 14 thereof meshes with the tightening claw 2 and the wedge portions 7 and 18 of the sliding member 17 to draw it. The plate 33 is pressed against the retaining member 20 by the urging force of the spring 34, so that the retaining member 20 is engaged with the retaining hole 8. In this state, when the wedge member 10 is slid back and forth, the wedge action of the wedge groove 14 and the wedge portions 7 and 18 causes both the tightening claws 2 and the sliding member 17 to move the radius of the chuck body 1 together. The workpieces (not shown) are attached to and detached from the top jaws 4 of the tightening claws 2 by opening and closing all at once. 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 intrude into the retaining hole 8 due to the machining of the workpiece, 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. Is discharged to the outside of the chuck. Therefore, there is no possibility that cutting chips will get stuck 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, so that the clamping claw 2 can be gripped. It is possible to prevent the phenomenon that the power decreases. Therefore, an expensive dustproof device such as a chuck cover, a dust seal or an air purge is unnecessary. 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. However, the centrifugal force is significantly attenuated by the wedge action and is attached to the cylinder that drives the wedge member 10. The wedge member 10 is not likely to be moved by centrifugal force because it has a slight value compared with the force.

When exchanging the tightening claw 2 according to the diameter of the workpiece, in the state shown in FIG. 1, the wedge member 10 is retracted by the draw tube 16 and the wedge groove 14 and the wedge portions 7 and 18 are meshed with each other. As a result, the tightening claws 2 and the sliding member 17 are simultaneously closed and moved, and the draw plate 33 is pushed rearward by the wedge member 10 to be separated from the retaining member 20. When the wedge member 10 reaches the retracted end position, each fastening claw 2 is completely disengaged from the wedge member 10, but the engagement of the retaining member 20 and the retaining hole 8 chucks the clamping claw 2. Since the movement to the outer peripheral side is restricted, each tightening claw 2 is securely held on the chuck body 1 without coming 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 tightening claw 2 is disengaged from the chuck body 1. Therefore, the tightening claw 2 can be moved to the outer side in the radial direction and removed from the chuck body 1, and the new tightening 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 tightening claw 2 toward the chuck center, and accurately positions the tightening claw 2 at the position where the retaining hole 8 faces the retaining member 20. ..

When the new tightening claw 2 is attached, the wedge member 10 is then advanced and the drawer plate 33 is moved forward by the spring 34. The draw plate 33 pushes the retaining member 20 into engagement with the retaining hole 8, whereby the new fastening claw 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 manner 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 of the lever 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 jaw 3 is provided with a weight-reducing hole 36 for reducing the weight thereof so as to open on the outer peripheral surface of the chuck. A chip escape portion 24 is obliquely connected to the removal preventing hole 8 so as to be positioned closer to the outer circumference of the chuck than the removal preventing member 20, and the prevention hole 8 is connected to the weight-reducing hole 36 via the chip escape portion 24. Has been done. The fine chips that have entered the removal-preventing hole 8 are blown off by the centrifugal force to the chip escape portion 24, and then discharged through the weight-reducing hole 36 to the outside of the chuck. 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, the chuck outer peripheral side of the retaining member 20. A chip escape portion 24 is continuously provided at a portion located at. Also in this case, since 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, there is no possibility that the cutting chips will be 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 retained by the holding plate 38. The eccentric pin 37 includes an insertion hole 39 into which a wrench (not shown) is inserted and removed, and an eccentric protrusion 41 that fits into the circumferential groove 40 of the retaining member 20. The eccentric pin 37 is rotated by the wrench to prevent the retaining member. 20 is configured to be able to engage with and disengage from 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 a draw screw 46 via a screw sleeve 44 and a retaining ring 45. The other structure and operation, 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 may be used as the wedge member, or the wedge member 10 and the draw plate 33 may be used as the parent-child cylinder. Drive each separately, integrally configure the wedge member 10 and the draw plate 33, appropriately change the shapes of the retaining hole 8, the retaining member 20 and the chip escape portion 24, push pin 29 and eccentricity. The shape and configuration of each part can be arbitrarily changed without departing from the gist of the present invention, for example, the pin 37 is operated by the robot arm of the pawl exchanging device to automatically exchange the fastening pawls 2. It is also possible to materialize.

[0020]

[Effect of the device]

 As described above in detail, according to the present invention, even when exchanging the pawl, the wedge portion of the clamping pawl is engaged with the engaging portion of the wedge member, so that the clamping pawl can be grasped with respect to the workpiece. Precision can be maintained. Also, since the entire tightening claw is replaced, the conventional base jaw can be omitted, and 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 outer peripheral side of the chuck, 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 replacement of the claw. In addition, the chips that have penetrated the retaining holes are spun off by the centrifugal force to the chip escape section, so there is no risk of chips getting stuck between the retaining holes and the retaining member, and the sliding members are tightened by the centrifugal force. It is possible to prevent the phenomenon that the gripping force of the nail decreases.

[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 a 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 ・ ・ Clamping jaws 3 ・ ・ Master jaws 4 ・ ・ Top jaws 7 ・ ・ Wedges 8 ・ ・ Retaining holes 10 ・ ・ Wedge members 11 ・ ・ Pilot plates 12 ..Boss portions, 14 ... Wedge grooves, 16 ... Draw tubes, 17 ... Sliding members, 20 ...
・ Notch ball, 24 ・ ・ Chip escape part, 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 wedge portions are mounted on a chuck body so as to be movable in the radial direction, and a wedge member having an engaging portion that meshes with the wedge parts 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 that it can slide 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 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 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 portion located in the chuck outer peripheral side of the retaining hole is located in the retaining hole. A chuck that is characterized by being formed in series.