JP2019084635A - Chuck device - Google Patents

Abstract

To provide a chuck device having a taper spigot structure.SOLUTION: The chuck device comprises: a chuck mechanism that holds a work-piece in a rotary shaft direction; a guide member, fixed to a base member, which has a first inner taper formed on an inner peripheral surface of an insertion part of a guide hole; a cylindrical support member, which can be inserted into the guide member by moving in a shaft direction and has a first outer taper corresponding to the first inner taper molded therein; a shaft member for spin finishing, fixed to the support member, which has a second outer taper formed at a tip part thereof; a claw member for spin finishing, arranged outside the shaft member for spin finishing, which has a second inner taper corresponding to the second outer taper formed therein; and a transmission member, connected to the claw member for spin finishing, which can move the inside of the support member in the shaft direction.SELECTED DRAWING: Figure 2

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a chuck device having a centering mechanism for centering a workpiece to be gripped, and a portion of the centering mechanism moving largely.

  In a machine tool or the like, a chuck device is used as a configuration for setting a work to be processed on a spindle. The chuck device has, for example, a structure having a structure for gripping the work while performing centering on the work. Patent Document 1 below discloses a chuck device provided with the centering function. The chuck device of the same document is a collet chuck, and a configuration is disclosed in which a workpiece is clamped from inside by centering by enlarging a diameter of a gripping portion thereof. Specifically, the gripping member is connected to the rod passing through the main shaft, and by retracting by the rotating cylinder, the gripping claws are expanded in diameter by the tapered surface with the centering cylinder, and the workpiece is clamped from the inside It has become. On the other hand, when the gripping member advances, the gripping claws are closed by the thin-walled portion displaced in the radial direction, and the workpiece is unclamped.

JP 11-114706 A

  In the conventional chuck device, a shaft member connecting the rod and the gripping member is configured to slide in the central hole on the base side so as to stabilize the axial movement of the gripping member. And, the shaft member and the center hole are inlaid with each other with almost no gap. However, such a spigot structure is preferable when the amount of movement of the centering member for centering is small as in the conventional example, but when the centering member moves largely, the center of the shaft member and the base side It becomes difficult to obtain hole processing accuracy. Then, if the processing accuracy of the parts is lowered, the centering accuracy is lowered, and in turn, the processing accuracy for the workpiece is lowered.

  Then, this invention aims at providing the chuck device of a taper-in-row structure, in order to solve this subject.

  The chuck device according to the present invention comprises: a chuck mechanism for gripping a workpiece in the rotational axis direction; a guide member fixed to the base member and having a first inner taper formed on the inner peripheral surface of the insertion portion of the guide hole; The tubular support member is insertable into the guide member and is formed with a first outer taper corresponding to the first inner taper, and is fixed to the support member, and a second outer taper is formed at the tip. And the centering claw member disposed outside the centering shaft member and on which the second inner taper corresponding to the second outer taper is formed, and the inside of the support member. A transfer member axially movable and coupled to the centering pawl member;

  According to the above configuration, the support member is coaxially positioned with respect to the guide member by the fitting of the first inner taper and the first inner taper, and centering is performed by the tapered inlay structure. Then, the centering claw member is moved via the transmission member provided inside the support member, whereby the second outside between the centering shaft member fixed to the support member and the centering claw member Fitting of the taper and the second inner taper is performed, and centering of the work by the centering claw member is performed.

It is a sectional view showing a spindle device of a machine tool. It is a sectional view at the time of centering which showed one embodiment of a chuck device, and a work clamp. It is a sectional view at the time of work processing which showed one embodiment of a chuck device. It is a front view showing one embodiment of a chuck device. It is an expanded sectional view showing a centering mechanism part of a chuck device.

  Next, an embodiment of a chuck device according to the present invention will be described below with reference to the drawings. In the present embodiment, a chuck device assembled to a spindle of a machine tool will be described as an example. FIG. 1 is a cross-sectional view showing a spindle device of a machine tool. This spindle device 1 is a face clamp type in which a spindle 12 is rotatably assembled inside a cylindrical spindle head 11, and the workpiece is gripped in the direction of the rotation axis (X-axis direction) with respect to the tip of the spindle 12. The chuck device 5 is assembled.

  A pulley 13 is fixed to the spindle 12 and a belt is stretched between it and a pulley fixed to the rotation shaft of a spindle motor (not shown). Further, an encoder (not shown) is provided on the spindle 12 to detect the number of rotations. Therefore, in the spindle device 1, rotation is applied to the spindle 12 from the spindle motor whose rotation is controlled via the pulley 13, and the rotation is transmitted to the chuck device 5, and rotation at the time of processing is performed on the workpiece clamped there. It will be given.

  In the spindle device 1, first to third drawbars 15, 16, and 17 connected to the chuck device 5 are coaxially assembled inside the spindle 12. Specifically, a cylindrical second drawbar 16 is inserted into the cylindrical first drawbar 15, and a solid rod third drawbar 17 is inserted inside the second drawbar 16. Each of the drawbars 15, 16 and 17 is constituted by connecting a plurality of members in the axial direction, and each has an actuator for driving each mechanism of the chuck device 5. In the present embodiment, a hydraulic cylinder is used as an actuator.

  The outermost first drawbar 15 is connected to the piston of the chuck cylinder 21. The second drawbar 16 is connected to the advancing / retracting cylinder 23 via the connecting rod 22 on the rear side (XL side). The expansion and contraction operation of the advancing and retracting cylinder 23 is such that an axial stroke larger than the first and third drawbars 15 and 17 is given to the second drawbar 16. The third draw bar 17 is connected to the piston of the centering cylinder 25 formed in the connecting rod 22. That is, the third drawbar 17 is axially movable integrally with the second drawbar 16, and the axial movement of the centering cylinder 25 is enabled inside the second drawbar 16. There is.

  Next, FIGS. 2 and 3 are cross-sectional views showing the chuck device 5 of the present embodiment, and in particular, FIG. 2 is a view showing the state at the time of centering and work clamping. It is the figure which showed the state at the time of the workpiece | work process which evacuated the protrusion part. And FIG. 4 is a front view showing the chuck device 5 from the axial direction (right side of FIG. 2). The chuck device 5 of the present embodiment is provided with a face clamp type chuck mechanism for gripping the work W in the rotational axis direction (X axis direction), and a centering mechanism for centering the work W with respect to the rotational axis.

  In the chuck device 5, the base member 31 is fixed to the spindle 12, and the chuck mechanism and the centering mechanism are integrally assembled to the rotating base member 31. In the chuck mechanism, the first drawbar 15 is slidably inserted in a bearing member 32 fixed to the base member 31, and a radially extending arm member 33 is connected to the tip of the first drawbar 15. . An operating shaft (not shown) extending in the axial direction is connected to the arm member 33, and a rotating shaft 34 is connected to the operating shaft.

  The rotary shaft 34 is formed with an obliquely cut lead groove so that axial movement from the first drawbar 15 can be transmitted also in the rotational direction. Accordingly, the pivot shown in FIG. 4 is given to the top jaw 35 fixed to the rotation shaft 34 together with the axial displacement. That is, when the top jaw 35 located at the retracted position indicated by the alternate long and short dash line pivots to the chuck position indicated by the solid line, the top jaw 35 also moves in the direction (XL direction) to reduce the distance to the work metal 36. Clamping is performed. Then, when turning in the opposite direction, the top jaw 35 moves to the retracted position shown by the solid line and moves in the direction away from the work metal 36 (XR direction), and unclamping with the work W released is performed. .

  Next, the tip end of the second drawbar 16 inserted into the first drawbar 15 extends to the inside of the chuck device 5, and the support member 41 is coaxially fixed by the screw. The support member 41 has a cylindrical shape, and a centering mechanism is incorporated inside thereof. FIG. 5 is an enlarged sectional view showing the centering mechanism portion 8 at the time of centering shown in FIG. The centering mechanism portion 8 is configured to move largely inside the chuck device 5 in the axial direction as shown in FIGS. 2 and 3 with the support member 41 as a base. Specifically, in the centering state shown in FIG. 2, the support member 41 is inserted into the guide member 42, and in the retracted state shown in FIG. 3, the support member 41 moves to a position out of the guide member 42. There is.

  The guide member 42 is a cylindrical member fixed to the base member 31 side of the chuck device 5. On the other hand, the support member 41 is composed of an outer cylindrical portion 411 fitted into the inside of the guide member 42 and an inner cylindrical portion 412 fixed to the second drawbar 16 via a screw portion. The outer cylindrical portion 411 is formed with a flange portion and a step portion in the axial direction, but a first outer taper 415 is formed on a part of the outer peripheral surface near the flange. In the guide member 42, a first inner taper 425 corresponding to the first outer taper 415 is formed on the inner peripheral surface of the insertion side end portion of the support member 41. That is, in the present embodiment, the tapered inlay structure in which the support member 41 is coaxially positioned with respect to the guide member 42 is obtained by fitting the first outer taper 415 and the first inner taper 425 at the time of centering shown in FIG. It is taken.

  Subsequently, a cylindrical centering shaft member 43 is fixed to the support member 41. The flange portion 431 of the centering shaft member 43 is fixed to the end portion of the support member 41 by screwing, and a second outer taper 435 is formed on the outer peripheral surface of the axially opposite tip portion. A cylindrical collet member 44 is coaxially attached to the outside of the centering shaft member 43. The collet member 44 is formed with a thin-walled cylindrical portion 441 having a cut and a claw portion 442 on the block at the tip end portion of the cylindrical portion 44, and the claw portion 442 has a second outer taper on its inner circumferential surface A second inner taper 445 corresponding to 435 is formed.

  The collet member 44 is provided with a construction for transmitting the axial movement of the third drawbar 17. Particularly in the present embodiment, the transmission member 46 is provided with an adjusting means between the third drawbar 17 and the collet member 44. Is incorporated. An adjusting female screw portion 171 is formed at an end of the third drawbar 17, and an adjusting male screw 451 formed at the tip of the adjusting rod 45 is screwed in and both are connected in the axial direction. On the other hand, a hexagonal hole 453 is formed in the end face on the opposite side of the male screw 451 in the adjusting rod 45, and it is possible to adjust the screwing amount of the adjusting rod 45 by a hexagonal wrench. That is, the axial position adjustment of the adjustment rod 45 with respect to the third draw bar 17 is possible.

  The adjustment rod 45 is incorporated in the transmission member 46 so that the flange portion 455 is contained. The transmission member 46 is formed with a cylindrical portion 461 which can slide in the inner cylindrical portion 412 of the support member 41, and the adjustment rod 45 penetrates the cylindrical portion 461 in a slidable manner. The transmission member 46 is formed with a bowl-shaped receiving portion 462, and the flange portion 455 of the adjustment rod 45 is incorporated therein. Further, the transmission member 46 is formed with a connecting portion 463 passing through a through hole formed in the flange portion 431 of the support member 41, and the flange portion 443 of the collet member 44 is screwed there.

  The transmission member 46 is incorporated inside the support member 41 so as to be movable in the axial direction, and the axial movement from the third draw bar 17 for operating the collet member 44 is transmitted via the adjustment rod 45 It is supposed to be That is, the flange portion 455 is prevented from coming off by the clasp 47 fixed to the receiving portion 462 by a bolt, and the adjusting rod 45 and the transmission member 46 are integrally configured. Specifically, the flange portion 455 of the adjustment rod 45 is loosely fitted in the receiving portion 462 of the transmission member 46, so that the adjustment rod 45 can be rotated without rotating the transmission member 46. .

  In the flange portion 455, one hole is formed on one side in the axial direction, and a spring 48 holding the ball 49 is inserted therein. Then, the biased ball 49 is fitted into the positioning hole 465 formed in the transmission member 46. The positioning holes 465 are formed, for example, at four positions on the same circumference at intervals of 90 degrees with respect to the transmission member 46, and the adjustment in the adjustment rod 45 is performed at 90 degrees intervals where the balls 49 enter the positioning holes 465. It has become. That is, the position of the adjustment rod 45 with respect to the third drawbar 17 is axially displaced by the screwing amount of the male screw 451 at a 90 degree interval, and the pressing condition for closely attaching the second inner taper 445 to the second outer taper 435 Can be adjusted.

  Subsequently, the operation of the chuck device 5 of the present embodiment will be described. First, when the spindle device 1 is operated, the operator adjusts the centering mechanism 8 with respect to the chuck device 5. That is, in the chuck device 5, the lid member 50 for closing the tip of the centering shaft member 43 is removed, and the hexagonal wrench inserted into the through hole 433 is fitted into the hexagonal hole 453. Then, the adjustment rod 45 is rotated by a predetermined amount to perform axial position adjustment. That is, the second inner taper 445 of the collet member 44 is pressed against the second outer taper 435 of the centering shaft member 43 with a light force, and adjustment is performed so as to eliminate a gap where chips enter between the closely-adhered tapers. . Then, the following operation of the chuck device 5 of the spindle device 1 is performed.

  In the spindle device 1, at the time of clamping the workpiece W, the advancing / retracting cylinder 23 is first activated, and the output thereof is transmitted to the chuck device 5 via the second drawbar 16, and the centering mechanism portion 8 shown in FIG. Then, it is set in the centering state shown in FIG. At this time, the first outer taper 415 fits into the first inner taper 425, and the support member 41 becomes a tapered inlay coaxially with the guide member 42. Therefore, the centers of the centering shaft member 43 and the collet member 44 located inside the support member 41 are aligned on the rotation axis. Then, the workpiece W transported from the outside by the workpiece transport device is arranged as indicated by a dashed dotted line in FIG. 2 with respect to the chuck device 5.

  Then, the centering cylinder 25 of the spindle device 1 operates, and a force acts on the adjusting rod 45 via the third draw bar 17 in the XL direction, and the collet member 44 is pulled in the same direction. Then, the collet member 44 in which the second inner taper 445 is in close contact with the second outer taper 435 of the centering shaft member 43 receives force in the direction in which the claws 442 expand radially outward, and the inner side of the workpiece W Be pressed against. Therefore, the workpiece W which received the uniform pressing force which spreads in the radial direction is centered with the center position thereof aligned with the rotation center of the chuck device 5.

  When centering of the work W is performed, the chuck cylinder 21 is operated, and the output in the axial direction transmitted to the arm member 33 via the first drawbar 15 causes the top jaw 35 via the rotation shaft 34. Is given a turn. The top jaw 35 located at the retracted position shown by the alternate long and short dash line in FIG. 4 turns to the chuck position shown by the solid line and is displaced in the XL direction, and the work W is gripped in the axial direction by the contact metal 36 and the top jaw 35 . After the work W is clamped by the chuck device 5, the collet member 44 is pushed in the XR direction via the adjustment rod 45, and the claw portion 442 moves radially inward according to the second outer taper 435. Centering condition is released. Then, the advancing / retracting cylinder 23 of the spindle device 1 operates, and the centering mechanism portion 8 shown in FIG. 5 moves to the position shown in FIG. 2 to FIG. 3 and retracts.

  In the spindle device 1, rotation is given to the spindle 12 from the spindle motor (not shown) via the pulley 13, and rotation is given to the chuck device 5 via the base member 31 fixed to the spindle 12. On the other hand, in the chuck device 5, since the space is made inside the work W by the retraction of the centering mechanism portion 8, boring is performed by the cutting tool 51 inserted into the inside of the work W.

  When boring of the work W is performed as described above, the centering mechanism portion 8 needs to move largely as shown in FIGS. 2 to 3. However, the support member 41 in the centering state, which has been largely moved forward, must be centered with the guide member 42. However, as described in the above-mentioned task, the inlay structure provides sufficient processing accuracy. It becomes difficult. In that respect, in the present embodiment, a tapered inlay structure is adopted in which the first outer taper 415 and the first inner taper 425 are fitted and the center of the support member 41 is aligned with the guide member 42. Therefore, even if the movement distance in the axial direction is large, machining accuracy can be easily obtained, and as a result, sufficient centering accuracy with respect to the workpiece W can be obtained.

  In the chuck device 5, as shown in FIG. 3, machining is performed near the end surfaces of the centering shaft member 43 and the collet member 44, and chips and coolant of the workpiece W are scattered. Therefore, if there is a gap between the second outer taper 435 and the second inner taper 445, chips enter there and the centering of the work W becomes impossible. As a result, processing defects on the workpiece W will be caused. In that respect, in the present embodiment, since the second outer taper 435 can be brought into close contact with the second inner taper 445 by the adjustment rod 45 contained in the transmission member 46, chips and the like generated during processing can be both There is no possibility of invading between the tapers, and the proper centering operation for the work W can be maintained.

  In particular, since an appropriate close contact state that does not apply an excessive load by the operation of the adjustment rod 45 is created, a large load is not applied to the thin cylindrical portion 441, and the life of the collet member 44 is sufficiently obtained. be able to. And in this embodiment, the adjustment means which consists of the rod 45 for adjustment, the transmission member 46, etc. is integrated inside the support member 41, and it has a compact structure. In addition, a spring 48 and a ball 49 for positioning the adjustment rod 45 after adjustment are incorporated in the transmission member 46, which is also a compact configuration. Therefore, the axial dimension of the chuck device 5 in which the moving distance of the centering mechanism portion 8 is large can be suppressed to a small size, and furthermore, it contributes to suppressing the enlargement of the main spindle device 1 which is the main body.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.

Reference Signs List 1 spindle device 5 chuck device 8 centering mechanism 12 spindle 15 first draw bar 16 second draw bar 17 third draw bar 21 chuck cylinder 23 advancing / retracting cylinder 25 centering cylinder 41 Support member 42 Guide member 43 Centering shaft member 44 Collet member 45 Adjustment rod 46 Transmission member 47 Clamp 415 First outer taper 425 First inner taper 435 Second outer taper 445 Second inner taper

Claims (4)

A chuck mechanism that holds the work in the rotational axis direction,
A guide member fixed to the base member and having a first inner taper formed on the inner peripheral surface of the insertion portion of the guide hole;
A cylindrical support member insertable into the guide member by axial movement and having a first outer taper formed corresponding to the first inner taper;
A centering shaft member fixed to the support member and having a second outer taper formed at a tip end thereof;
A centering claw member disposed outside the centering shaft member and having a second inner taper corresponding to the second outer taper;
And a transmission member which is axially movable inside the support member and is connected to the centering claw member.   The chucking device according to claim 1, wherein the transmission member is connected to a transmission rod that transmits an axial output via an adjustment rod screwed by the transmission rod and an adjustment screw.   The chuck device according to claim 2, wherein the adjustment rod is incorporated such that the flange portion is included in the transmission member, and the screw portion is formed at a tip portion which penetrates the transmission member in the axial direction. A spring member holding a ball is inserted into a hole formed in a flange portion of the adjustment rod, and the spring member is fitted into a plurality of positioning holes formed on the same circumference with respect to the transmission member. The chuck device according to claim 3, wherein a ball is biased by the spring member.

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