JP2007283408A - Collet chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collet chuck having a limited outside diameter size of a collet cylinder, allowing replacement of a collet claw in a short time when an object to be held changes in its diameter, in the collet claw replacement structure of the collet chuck. <P>SOLUTION: The collet claw 1 can be removed from a pull rod 6 and fixed thereto by single operation. The base end of the collet claw 1 is fixed to the tip of the pull rod 6 by twisting in the engagement direction, and the base end of the collet claw is separated from the tip of the pull rod 6 by twisting in the reverse direction. The thus constructed engagement pair 10, 11 are provided between the base end of the collet claw 1 inserted in a collet cylinder 3 and the tip of the pull rod 6, and a spring 15 for always energizing the collet claw 1 in the direction of holding the engagement state of the engagement pair 10, 11 is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a collet claw replacement structure of a collet chuck.

  The collet chuck is provided with a conical surface on the outer periphery of a collet claw having a plurality of gripping claws located on the circumference, and a collet claw between a collet cylinder provided with a conical surface in sliding contact with the conical surface on the inner periphery. By moving in the relative axial direction, the gripping claw is reduced in diameter by a wedge action caused by sliding between the conical surfaces, and the object (work) inserted between the collet claws is gripped.

  The collet chuck has a relatively simple structure and can have a small diameter, so it does not require high gripping accuracy or strong gripping force. For example, a tool chuck for a small drilling machine or a loader / unloader that transports a cylindrical workpiece to a machine tool. Widely used as a workpiece gripping chuck.

  FIG. 5 is a view showing an example of a collet chuck used in an unloader for unloading a workpiece from a lathe. Two spindles 40L and 40R located on the same axis and machining in cooperation with these spindles. An example in which a bar material is processed by a two-spindle opposed lathe provided with two tool rests 41L and 41R to be performed is shown. The two main shafts 40L and 40R of the lathe shown in the drawing are both hollow shafts, and chucks 42L and 42R for gripping a workpiece are attached to their opposing ends.

  The bar material 35 to be processed is carried by a loader (a pusher or a bar feeder) (not shown) through the hollow hole of the main shaft 40L on the left side of the drawing. The loaded workpiece 35 is gripped by the chuck 42L with its tip (right end in FIG. 5) protruding from the chuck 42L, and processed by the tool 43L mounted on the left tool post 41L in the drawing. Next, the bar material 35 is transferred to the chuck 42R on the right side of the figure by the approaching / separating operation of the main shafts 40L, 40R and the alternating opening / closing operation of the chucks 42L, 42R. A long bar material that needs to be processed in the intermediate portion is processed in the state in which the both ends of the bar material are gripped by the chucks 42L and 42R and the main shafts 40L and 40R are synchronously rotated during the delivery. The bar material delivered to the chuck 42R on the right side of the drawing is processed at the rear end (left side end portion in the drawing) by the tool 43R mounted on the tool post 41R on the right side of the drawing, and then the chuck 42R is opened and the right side is opened. It is carried out through the hollow hole of the main shaft 40R.

  FIG. 5 shows an unloader 45 that carries out the bar material. The unloader 45 is an elongated member having a collet chuck 46 at the tip and an outer diameter that can be inserted into the hollow hole of the main shaft 40R. The unloader 45 reciprocates in the axial direction of the main shaft 40R by a conveyor or a cylinder not shown in the drawing.

  When the processing of the bar material 35 is completed while being held by the right chuck 42R of the lathe, the unloader 45 moves forward, the tip portion thereof is inserted into the hollow hole of the main shaft 40R, and the processed bar material 35 is processed by the collet chuck 46. The tip is gripped. Next, the chuck 42R is opened, the unloader 45 is retracted, and the processed bar material 35 is pulled out from the hollow hole of the main shaft 40R. Next, the collet chuck 46 is opened, and a push rod built in the collet chuck 46 pushes the tip of the work 35 out of the collet chuck, and the processed bar material is a work such as a conveyor 47 provided between the lathe and the unloader 45. Drop onto the transfer device.

  FIG. 6 is a cross-sectional view showing a collet chuck having a conventional structure used for the unloader described above. Reference numeral 3 denotes a collet cylinder, which is provided with a conical inner peripheral surface 48 in a direction in which the front end side expands on the inner periphery of the front end, and a base end is fixed to the outer cylinder 2 of the unloader by a fixing screw 49. A collet claw 1 is formed with a conical outer peripheral surface 50 whose front end is widened on the outer periphery of the distal end portion, and a proximal end is screwed into a hollow pull rod 6 of an unloader and fixed with a set screw 51. The collet claw 1 is a cylindrical member, and by providing a dividing groove that divides the circumference into, for example, six equal parts from the front end side, the equally divided number of gripping claws are formed at the front end portion. The push rod 4 is inserted into the hollow hole of the pull rod 6, and in the example shown in the figure, a knockout piece 5 is fixed to the tip of the push rod 4 with a screw so as not to damage the product.

  The collet chuck 46 pulls the pull rod 6 while the push rod 4 is retracted, whereby the collet claw 1 is pulled to the back side of the collet cylinder 3, and the cone inner peripheral surface 48, the cone outer peripheral surface 50, The plurality of gripping claws 27 divided and formed by the sliding movement are pushed toward the inner diameter side to grip the work inserted into the collet claw 1. Then, after the unloader 45 is retracted and the workpiece is pulled out, the pull rod 6 is moved forward, whereby the collet claw 1 is released from the conical inner peripheral surface 48 of the collet cylinder and is moved to the outer diameter side by its own elasticity. Return and release the workpiece. Thereafter, the push rod 4 is advanced, and the work is pushed out from the collet chuck 46 by the knockout piece 5.

The forward / backward movement of the pull rod 6 and the forward / backward movement of the push rod 4 with respect to the outer cylinder 2 of the unloader are performed by a cylinder or the like disposed at the base end of the unloader (the right end in FIG. 5 and the left end in FIG. 6). . Accordingly, the base ends of the pull rod 6 and the push rod 4 are connected to these advance / retreat devices by screws, bolts, and the like.
Japanese Patent Laid-Open No. 9-123055

  Like the collet chuck used in unloaders with the above structure, the collet chuck used in devices that pull out and insert objects to be grasped through hollow holes or recesses is limited to the outer diameter of the collet cylinder For this reason, the collet claw gripping stroke (radial opening / closing stroke) cannot be increased. Therefore, when the diameter of the object to be grasped changes and deviates from the collet claw stroke, it is necessary to replace the collet claw.

  At this time, in the collet chuck having the conventional structure as shown in FIG. 6, it is necessary to pull out the collet claw 1 fixed to the tip of the pull rod 6, loosen the set screw 51, and replace the collet claw. And when pulling out the pull rod 6, it is necessary to release the connection between the advancing / retreating device connected to the base end and the pull rod, and in general, the bolts and screws of the connecting portion covered by the cover are removed, After replacing the collet claw, it is necessary to further connect the base end of the pull rod 6 and the advancing / retracting device and close the cover. For these operations, the collet claw 1 needs to be replaced for about 20 minutes. It took work time.

  An object of the present invention is to provide a collet chuck in which the outer diameter of the collet cylinder is limited, and the collet chuck can be replaced in a short time when the diameter of the object to be grasped changes. It is said.

  In the present invention, the above-mentioned problem is solved by allowing the collet claw 1 to be detached from the pull rod 6 and fixed to the pull rod 6 at the time of collet claw replacement.

  That is, in the collet chuck of the present invention, the base end of the collet claw 1 is fixed to the front end of the pull rod 6 by being twisted in a predetermined direction (fitting direction), and the base of the collet claw is twisted in the reverse direction. An engagement pair 10, 11 having a structure in which the end is detached from the distal end of the pull rod 6 is provided between the proximal end of the collet claw 1 inserted into the collet cylinder 3 and the distal end of the pull rod 6. The above-mentioned problem is solved by providing a spring 15 that constantly biases the collet claw 1 in a direction in which the state where the 11 is engaged is maintained.

  The preferred engagement pair is a pair of a plurality of engagement pins 10 planted in the radial direction at the distal end of the pull rod 6 and an L-shaped groove 11 provided at the proximal end of the collet claw 1 for receiving it. The L-shaped groove 11 includes an axial direction portion 18 and a circumferential direction portion 19 extending from the back end to one side in the circumferential direction. A preferable shape of the L-shaped groove 11 includes an inclined portion 20 that is inclined in a direction returning to the axial direction portion 18 between the inner end of the circumferential direction portion 19 and the connecting portion to the axial direction portion 18.

  The spring 15 is a compression spring or a torsion spring disposed on the inner diameter side of the collet claw 1. The spring 15 includes an elastic body having a spring property. In a preferred structure, the compression spring is a coil spring that urges the collet claw 1 in the direction of detachment from the tip of the pull rod 6, that is, in the direction of pushing the collet claw 1 out of the collet cylinder 3. The urging force of the compression coil spring 15 is applied to the collet claw 1 by the engagement between the outer periphery of the spring receiver and the step 12 provided on the inner periphery of the collet claw 1 via the spring receiver 14 inserted through the push rod 4. Communicated.

  The collet chuck according to the invention of claim 1 of the present application is a collet chuck that grips an object to be gripped by pulling the collet claw 1 inserted into the collet cylinder 3 in the axial direction with a pull rod 6, and a radial engagement pin 10 and An engagement pair formed by an L-shaped groove 11 into which the engagement pin is inserted is provided between the base end of the collet claw 1 and the tip of the pull rod 6, and is located on the inner peripheral side of the collet claw 1. The collet chuck is provided with a spring 15 that biases the engagement pair in a direction in which the engagement pair is always engaged.

  The collet chuck according to claim 2 of the present application is the collet chuck having the structure according to claim 1, wherein the L-shaped groove 11 is engaged with the engagement pin 10 without causing any axial movement. And a slanted portion 20 that is slanted in the return direction of the axial direction portion between the deep end and the axial direction portion 18.

  A collet chuck according to a third aspect of the present invention is a collet chuck having the configuration according to the first or second aspect, wherein the collet chuck is inserted into a push rod 4 provided at the shaft center of the collet claw 1. 1 is provided, and the spring 15 is a coil spring mounted between the spring receiver and the tip of the push rod 4. is there.

  The collet chuck of the present invention can be removed from the tip of the pull rod 6 by pushing the tip of the collet claw 1 toward the back of the collet tube 3 and twisting it. Also, the collet claw to be newly mounted is inserted into the collet tube 3 at the base end, the collet claw 1 is rotated to align the positions of the engagement pairs 10 and 11, and the collet claw 1 is further pushed in and removed. By twisting in the opposite direction, it can be attached to the tip of the pull rod 6.

  Therefore, the collet claw 1 can be attached to and detached from the tip of the pull rod 6 by one operation of twisting while pushing the collet claw 1, so that the collet claw can be easily replaced in a very short time. effective.

  1 to 4 are views showing an example of a preferred embodiment of a collet chuck according to the present invention. FIG. 1 is a cross-sectional view taken along the line AA of FIG. 2 is a side view of the collet claw, FIG. 3 is a front view of the collet claw, and FIG. 4 is a view showing an L-shaped groove.

  In the figure, 2 is an outer cylinder, 3 is a collet cylinder fixed to the tip of the outer cylinder 2, 4 is a push rod, 5 is a knockout piece fixed to the tip of the push rod, and the collet claw 1 has a split groove 28. A split claw 27 is provided. These are not different from those of the conventional structure shown in FIG. Reference numeral 6 denotes a pull rod, and an engagement pin 10 is planted at a position that divides the circumference of the outer periphery of the tip into three equal parts.

  Reference numeral 1 denotes a collet claw, and three L-shaped grooves 11 to be engaged with the engagement pin 10 are provided at the base end thereof. An inner flange 13 for forming the stepped portion 12 is provided on the inner peripheral surface of the collet claw 1, preferably at a position proximal to the center. A spring receiver 14 is inserted into the push rod 4, and a compression coil spring 15 is mounted between the spring receiver 14 and the tip of the pull rod 6 in a state of being inserted into the push rod 4. The spring receiver 14 in the figure has a hat shape, and an outer flange 16 on the outer periphery thereof is engaged with a step 12 provided on the inner periphery of the collet claw by the urging force of the compression coil spring 15. Yes.

  As shown in FIG. 4, the L-shaped groove 11 provided at the base end of the collet claw 1 has an L shape including an axial direction portion 18 and a circumferential direction portion 19, and the return of the axial direction portion 18 to the circumferential direction portion 19. An inclined portion 20 is provided which is inclined in the direction (the direction in which the L-shape is the shape). The L-shaped groove 11 having the same shape is provided at a position that divides the circumference of the base end of the collet claw 1 into three equal parts. Although it is not equally divided and it is good also as 2 or 4 or more, it is most preferable to provide 3 in the position of equally divided. The groove width of the L-shaped groove 11 is wider than the diameter of the engagement pin 10 implanted radially at the tip of the pull rod 6, but the groove width of the rear end 21 of the circumferential portion 19 is that of the engagement pin 10. The minimum fitting tolerance required for insertion / removal should be provided so that excessive play is not generated between the engagement pin 10 and the connector.

  In the collet chuck having the above structure, the collet claw 1 is inserted into the collet cylinder 3, and the collet claw 1 is rotated in a state where the back end of the collet claw 1 collides with the engagement pin 10, thereby engaging the engagement pin 10 and the L-shaped groove. In this state, the collet claw 1 is further pushed, and the collet claw 1 is twisted so that the engaging pin 10 moves to the circumferential direction portion 19 of the L-shaped groove, and then the pushing force By releasing the twisting force, the engagement pin 10 is fixed to the tip of the pull rod 6 in a state where the engagement pin 10 is engaged with the inner end 21 of the circumferential portion of the L-shaped groove.

  If the pull rod 6 is pulled in this state, the collet claw 1 moves in the direction of being pulled into the back side of the collet cylinder 3, and the gripping claw 27 is squeezed to the inner diameter side, and the gripping object inserted inside the collet claw 1 Hold an object. Further, when the pull rod 6 is advanced, the collet claw 1 is advanced by the engagement between the engagement pin 10 and the rear end of the circumferential portion 19 of the L-shaped groove, and the grip claw 27 is opened to release the gripping object. To do. The operation of the push rod 4 is the same as that of the conventional structure.

  When removing the collet claw 1, the engagement pin 10 is twisted so as to move toward the axial direction portion 18 while pushing the collet claw 1 into the back side of the collet cylinder 3, and when the pushing force and the twisting force are released, the spring 15 Since the collet claw 1 is pushed out by this urging force, the tip of the pushed collet claw may be picked and pulled out from the collet tube 3. If the collet claw to be newly attached is fixed to the tip of the pull rod 6 by the above-described operation, the collet claw 1 can be replaced.

  The jig 23 shown in FIG. 1 is a jig that allows the collet claw 1 to be easily pushed and twisted when the collet claw 1 is attached and detached. The illustrated jig 23 includes an insertion plate 24 that is inserted into the tip of the collet cylinder 3 and a handle 25 that is fixed to the insertion plate. The insertion plate 24 includes a fin 26. A diametrical groove 22 into which the fin 26 is fitted is provided at the tip of the collet claw 1, and the fin 26 is inserted into the groove 22 to perform the above-described pushing and twisting operation of the collet claw 1 at the time of attachment / detachment. By using such a jig, it is easy to push and twist the collet claw 1 when the collet claw is attached or detached.

  Since the collet chuck according to the present invention does not require the pull rod 6 to be pulled out when the collet claw 1 is replaced as described above, the base end of the pull rod 6 may remain connected to the advance / retreat apparatus, and the troublesome pull rod and the advance / retreat apparatus can be attached and detached. No work is required.

  Further, the structure in which the collet claw is fixed by the engagement pair of the L-shaped groove 11 having the inclined portion 20 in the return direction and the engagement pin 10 between the axial direction portion 18 and the back end 21 of the circumferential direction portion 19 is as follows. The engagement pin 10 is stably held at the back end 21 of the circumferential portion 19 by the biasing force of the spring 15, and the axial movement of the pull rod 6 is lost due to the loose movement between the engagement pin 10 and the L-shaped groove 11. The collet claw 1 is transmitted to the collet claw 1 without causing the movement of the pull rod 6, so that the collet claw 1 is accurately opened and closed as the pull rod 6 moves back and forth, and the engagement pin 10 and the rear end 21 of the L-shaped groove are urged by the biasing force of the spring 15. The engagement state is stably maintained.

  In the present invention, the spring 15 for holding the engagement between the pull rod 6 and the collet claw 1 is provided on the inner diameter side of the collet claw, so that the outer diameter of the collet chuck is not increased and the spring is pushed. By mounting it in a state of being inserted through the rod 4, there is a feature that the position of the spring 15 can be stably maintained.

Sectional drawing which shows one Embodiment of the collet chuck | zipper of this invention Side view of the collet claw of the collet chuck of FIG. Front view of collet claw Development view showing the shape of the L-shaped groove provided at the base end of the collet claw A diagram schematically showing the relationship between a lathe and an unloader equipped with a collet chuck. Sectional view showing an example of a collet chuck having a conventional structure

Explanation of symbols

1 Collet claw 3 Collet tube 4 Push rod 6 Pull rod
10 Engagement pin
11 L-shaped groove
14 Spring support
15 Spring
18 Axial section
20 Inclined part
21 Circumferential end

Claims (3)

  In the collet chuck that grips the object to be grasped by pulling the collet claw (1) inserted into the collet cylinder (3) in the axial direction with the pull rod (6), the radial engagement pin (10) and the engagement pin are An engagement pair formed by an L-shaped groove (11) to be inserted is provided between the base end of the collet claw (1) and the tip of the pull rod (6), and the inner peripheral side of the collet claw (1) A collet chuck provided with a spring (15) that is positioned at a position and biases the engagement pair in a direction in which the engagement pair is always engaged.   The L-shaped groove (11) engages the engaging pin (10) without causing axial movement, and the circumferential portion back end (21), and the back end and the axial direction portion (18). The collet chuck according to claim 1, further comprising an inclined portion (20) inclined in the return direction of the axial portion.   A spring receiver (14) is inserted through a push rod (4) provided at the axis of the collet claw (1) and engaged with the inner periphery of the collet claw (1), the spring (15), The collet chuck according to claim 1 or 2, wherein the collet chuck is a coil spring mounted between the spring receiver and the tip of the push rod (4).

Images