JP4522108B2 - Collet chuck device - Google Patents

Description

  The present invention relates to a collet chuck device for grasping an inner peripheral surface of a workpiece during lathe processing or the like.

  For example, as shown in FIG. 5A, the conventional collet chuck device has a cylindrical shape having a grip portion 3 that holds an inner peripheral surface of a workpiece W on a shank 1 that protrudes from a front portion of a cylindrical chuck body 20. The collet 2 is attached to the shank 1 so as to be movable back and forth in the axial direction (front-rear direction). A tapered surface 1a that tapers toward the front is formed on the outer peripheral surface of the tip of the shank 1, and a tapered taper corresponding to the tapered surface 1 a of the shank 1 is formed on the inner peripheral surface of the collet 2. Surface 2a is formed.

By fitting the collet 2 to the tip of the shank 1, both tapered surfaces 1a, 2a are brought into close contact with each other, and the tapered surface 1a, 2a slides as the collet 2 advances and retreats. A plurality of split grooves 4 are formed around the cylinder axis of the collet 2 from the front surface in the cylinder axis direction, and the collet 2 is divided around the circumference by the split grooves 4 so that the outer diameter is a radius. It is easy to expand and contract in the direction.

  As shown in FIG. 5A, the workpiece W is fitted from the front surface side of the chuck body 20 toward the stopper 5, and in this state, the collet 2 advances and retracts in the front-rear direction of the chuck body 20. Both the tapered surfaces 1a and 2a slide, and the grip portion 3 provided to protrude from the outer periphery of the collet 2 expands and contracts in the radial direction. By this expansion / contraction, the grip portion 3 grasps and releases the workpiece W from its inner peripheral surface (see, for example, Patent Document 1).

  Further, as another collet chuck device, the gripping part is separated from the collet to be a separate body, and the collet is divided into a body diameter member which is a main body and a diameter member which is the gripping part, and the diameter member is arbitrarily set. There is one that can be replaced with one with an outer diameter.

  A split groove is also formed at the front side end of the body diameter member, and the split groove forming portion (front side end) can be expanded and contracted in the radial direction. It is divided into a plurality of parts around and is fitted in an annular shape along the front side end of the body diameter member. According to this apparatus, when grasping a workpiece, it is possible to cope with workpieces of different diameters by using the diameter member in common and selectively using the aperture member according to the size. (For example, refer to Patent Document 2).

In addition, in order to prevent the collet from being damaged due to a significant deformation of the gripping part, there is also an apparatus in which an elastic material is wound around the outer periphery of the collet so as to restrain expansion more than necessary in the radial direction (for example, (See Patent Document 3).
Japanese Patent Laid-Open No. 64-45501 JP 2000-158216 A JP 2000-33503 A

  In the above collet chuck device, when it is desired to grasp a workpiece having a different diameter without replacing the entire chuck body, for example, as shown in FIGS. It is necessary to widen the outer diameter of the part in contact with the workpiece by replacing with a different collet.

  However, when the amount of protrusion increases, the amount of deformation of the protrusion accompanying the movement of the collet in the front-rear direction increases. For example, as shown by the chain line in FIG. And the main shaft are likely to be displaced. Further, if this deformation occurs repeatedly, it is not preferable because there is a risk that the collet may be damaged due to metal fatigue.

  Therefore, an object of the present invention is to make it possible to easily and accurately grasp workpieces having greatly different diameters with the same chuck device.

  In order to solve the above problems, the present invention provides a collet opening / closing shank of a chuck body, a collet attached directly to the shank with a sleeve interposed between the collet, and a slightly larger collet attached via a sleeve. It was made possible to handle both. In this way, a larger collet can be used for a workpiece having a diameter that exceeds the corresponding range of one collet, so the collet has a larger diameter by extending the workpiece gripping part to the outside. It is possible to cope with a workpiece having a larger diameter by using a predetermined collet with a small amount of overhang without using the. For this reason, the distortion of the collet can be reduced.

  Specifically, a collet opening / closing shank is provided in the chuck body, and the collet is fitted concentrically into the shank so as to be detachable, the tip outer peripheral surface of the shank is formed as a tapered surface toward the outside, and the taper of the shank of the collet is provided. The inner peripheral surface fitted to the surface is also a tapered surface corresponding to the tapered surface. The present invention relates to a collet chuck device for opening and closing the collet by the axial displacement of both tapered surfaces due to the relative advancement and retraction of the shank and the collet in the axial direction.

  The configuration enables the attachment sleeve to be concentrically detachably fitted and fixed to the shank, and allows the sub-collet different from the collet to be concentrically fitted to the attachment sleeve. Further, the outer peripheral surface of the tip of the attachment sleeve and the inner peripheral surface of the sub-collet fitted to the outer peripheral surface are tapered surfaces having the same taper as both tapered surfaces of the shank and the collet.

  In this way, the collet and sub-collet have the same amount of collet expansion / reduction relative to the degree of advancement / retraction relative to the shank. Therefore, even if the collet is replaced, the same grasping power can be maintained.

  Further, in the collet chuck device having the above-described configuration, a radial wall surface is provided on the rear outer peripheral surface of the shank, and the rear surface of the attachment sleeve is brought into contact with the wall surface to position the attachment sleeve in the axial direction. In addition, a cylindrical surface is provided behind the tapered surface of the shank, and the attachment sleeve inner peripheral surface is in contact with the tapered surface of the shank and the cylindrical surface so that the attachment sleeve is fixed to the shank. obtain.

  In this way, since the rear surface of the sleeve abuts against the wall surface of the shank, when the shank and the attachment sleeve are fixed, the positional relationship in the axial direction between them is always constant. As a result, the taper surface of the shank and the taper surface of the attachment sleeve can be easily maintained at the same taper. For this reason, the accuracy of the expansion / contraction degree of the sub collet when the attachment sleeve is used can be made equal to the expansion / contraction degree of the collet when the attachment sleeve is not used. Further, since the inner peripheral surface of the attachment sleeve is in contact with the tapered surface of the shank and the cylindrical surface thereof, the shank and the attachment sleeve are supported by a plurality of surfaces in the axial direction, and the surface is along the axis. Since the cross-sections are oriented in a plurality of different directions, the axial centers of the two are hardly displaced.

  Since the present invention is configured as described above, it can easily cope with chucking of workpieces having greatly different diameters with the same chuck device.

  1 to 3 show an embodiment of the chuck device according to the present invention, in which a chuck body 10 fixed concentrically to a spindle center c (hereinafter referred to as an axis c) of a lathe is connected to a chuck body 10 as shown in FIG. A disc-like base 31 provided with a collet opening / closing shank 1 protruding is attached to the front surface of the rear wall 30 of the chuck body 10. As shown in the figure, the bolt 34a inserted through the hole 34 of the base 31 is attached to the front surface of the rear wall 30 of the chuck body 10 so that the shaft center of the shank 1 is concentric with the axis c of the main shaft. It is fixed by screwing.

  The shank 1 fixed to the chuck body 10 is formed with a tapered surface 1a that gradually becomes thinner on the outer peripheral surface of the tip thereof toward the outer side, and a cylindrical surface 1b and its back are formed behind the tapered surface 1a. A cylindrical surface 36 having a diameter slightly larger than that of the cylindrical surface 1b is formed in order from the front to the rear. Further, a circular wall surface 37 extending in the radial direction and orthogonal to the axis c is provided on the rear outer peripheral surface of the cylindrical surface 36 of the shank 1.

  On the outer periphery of the shank 1, a cylindrical collet 2 or another cylindrical collet 22 having a diameter larger than that of the collet 2 via a cylindrical attachment sleeve 12 is selectively fitted. It is removable.

  As shown in FIG. 1, the attachment sleeve 12 is configured such that when attached to the shank 1, the rear surface 17, which is the rear end surface of the cylindrical attachment sleeve 12, is formed on the wall surface 37 at the rear of the shank 1. It abuts and the attachment sleeve 12 is positioned in the axial direction with respect to the shank 1. Further, the inner tapered surface 12a and the inner cylindrical surface 15 provided on the inner peripheral surface of the attachment sleeve 12 abut on the tapered surface 1a of the shank 1 and the cylindrical surface 36 behind the tapered surface 1a, respectively, and the attachment sleeve. 12 is fixed to the shank 1. The outer cylindrical surface 16 of the attachment sleeve 12 is flush with a cylindrical surface 38 formed toward the base 31 at the periphery of the wall surface 37.

  In this state, as shown in FIG. 1, the fixing bolt 14 inserted through the hole 13 of the sleeve 12 is screwed into the screw hole 33 of the wall surface 37 of the shank 1 to fix the attachment sleeve 12 to the shank 1. At this time, since both the shank 1 and the attachment sleeve 12 are fixed in surface contact with the tapered surfaces 1a and 12a, the cylindrical surfaces 36 and 15, the wall surface 37 and the rear surface 17, respectively, it is difficult to cause misalignment, etc. Even in the case of an external force acting on the attachment sleeve 12 in the radial direction or the torsional direction, both of them are in close contact with each other and are difficult to move.

  As shown in FIG. 2, the sub-collet 22 used when the attachment sleeve 12 is interposed on the outer periphery of the shank 1 is in close contact with the inner peripheral surface of the front portion corresponding to the outer tapered surface 12b of the sleeve 12. The sub-collet taper surface 22a is provided behind the sub-collet taper surface 22a with a cylindrical surface 26 that is in close contact with the outer cylindrical surface 16 on the outer periphery of the sleeve 12. As shown in the figure, the sub-collet 22 can be fitted concentrically on the outer periphery of the attachment sleeve 12, and in this fitted state, the sub-collet is attached to the outer tapered surface 12 b of the attachment sleeve 12 as shown in the figure. The tapered surface 22a is configured such that the cylindrical surface 26 of the sub collet slides in close contact with the outer cylindrical surface 16 of the sleeve 12 and the cylindrical surface 38 of the shank 1. Further, the collet 22 is formed with a plurality of split grooves 24 around the circumference thereof along the axial direction.

  The tapered surface 1a of the shank 1, the inner and outer tapered surfaces 12a and 12b of the attachment sleeve 12, and the sub-collet tapered surface 22a all have the same taper that equalizes the gradient with respect to the axis c. The same taper means that the angles formed by the inclined surfaces with respect to the axis c in the cross section along the axis c are equal.

  As shown in FIG. 3, the collet 2 used when the attachment sleeve 12 is not interposed has a collet taper surface 2 a that closely contacts the inner peripheral surface of the collet 2 corresponding to the taper surface 1 a of the shank 1. Behind the collet taper surface 2a, there is a cylindrical surface 6 that closely contacts the outer cylindrical surface 36 on the outer periphery of the shank 1. The collet 2 can be fitted concentrically on the outer periphery of the shank 1, and in the fitted state, the inner cylindrical surface 6 of the collet slides in close contact with the cylindrical surface 36 of the shank 1 as shown in the figure. It is like that. Further, the collet 2 has a plurality of split grooves 4 formed around the circumference thereof along the axial direction.

  The tapered surface 1a and the collet tapered surface 2a of the shank 1 have the same taper that equalizes the gradient with respect to the axis c. At this time, the taper surfaces of the same taper that do not slide relative to each other, for example, the inner and outer taper surfaces 12a, 12b, the axial positions and ranges of the taper surfaces 12a, 12b with respect to the axis c are When the collet 2 and the sub-collet 22 are attached, the axial positions and ranges of the gripping portions 3 and 23 must be completely matched as long as they do not hinder the work W. There is no freedom. However, as shown in FIG. 1, it is desirable that the position and the range are completely the same in order to stabilize the gripping force of the workpiece W or to stabilize the attachment sleeve 12 to the shank 1. Not too long.

  As shown in FIGS. 3 and 1, the collet 2 and the sub collet 22 are connected to an advancing / retracting plate 39 housed in a cylinder 35 in the rear wall 30. In the connection method, bolts 9 and 29 are inserted into holes 8 and 28 provided in the flanges 7 and 27 of the collets 2 and 22, and the bolts 9 and 29 slidably pass through the through holes 32 of the base 31. The spacers 9a and 29a are screwed into the advance / retreat plate 39, and the advance / retreat plates 39 and the collets 2 and 22 are connected via the spacers 9a and 29a. Since the spacers 9a and 29a are slidable in the through holes 32 of the base 31, as the advance / retreat plate 39 moves in the axial direction in the cylinder 35, the collets 2 and 22 are also integrally formed with the advance / retreat plate 39. It is designed to move in the direction.

  The cylinder 35 communicates with a fluid supply means (not shown), and the advance / retreat plate 39 is pressed by the fluid pressure supplied by the fluid supply means so as to be movable in the axial direction.

  Hereinafter, the operation when grasping the workpiece W will be described. First, when grasping the workpiece W having a relatively small diameter, the attachment sleeve 12 is not used and the outer circumference of the shank 1 is directly used as shown in FIG. Install collet 2. The work W is attached to the chuck body 10 so that the inner peripheral surface of the work W is fitted to the grip portion 3 on the outer periphery of the collet 2. At this time, the end surface of the workpiece W abuts against the stopper 5, so that the workpiece W can be easily positioned in the axial direction.

  When the advancing / retracting plate 39 moves rearward (leftward in the figure), the collet 2 is drawn backward, and the taper surface 1a of the shank 1 and the collet taper surface 2a of the collet 2 slide while the shank 1 and the collet. The positional relationship in the axial direction with 2 shifts. Due to this axial displacement, the collet 2 is expanded in diameter, the outer diameter of the grip portion 3 is expanded, and the inner peripheral surface of the workpiece W is grasped.

  When removing the workpiece W, conversely, the advance / retreat plate 39 moves forward (rightward in the figure), and the collet 2 is pushed forward. While the taper surface 1a of the shank 1 and the collet taper surface 2a of the collet 2 slide, the grip portion 3 of the collet 2 is reduced to the original diameter to open the workpiece W.

  Next, when grasping a workpiece W having a relatively large diameter, the attachment sleeve 12 is used to attach the attachment sleeve 12 to the outer periphery of the shank 1 and the sub collet 22 to the outer periphery thereof as shown in FIG. Install. The workpiece W is attached to the chuck body 10 so that the inner peripheral surface of the workpiece W is fitted to the gripping portion 23 on the outer periphery of the sub collet 22. At this time, the stopper 5 is replaced with a stopper 25 having a size larger than that of the sub collet 22, and the end surface of the workpiece W abuts against the stopper 25, so that the workpiece W extends in the axial direction. Can be easily positioned.

  The advancing / retreating of the collet 22 and the expansion / contraction action of the gripping part 23 accompanying the movement of the advance / retreat plate 39 are the same as those of the collet 2 described above.

  In this embodiment, the inner cylindrical surface 26 of the sub-collet 22 slides in close contact with the outer cylindrical surface 16 of the sleeve 12 and the cylindrical surface 38 of the shank 1, but is limited to this embodiment. Alternatively, only the outer cylindrical surface 16 of the sleeve 12 and the cylindrical surface 38 of the shank 1 may be slid in close contact with each other. Further, in this embodiment, the collets 2 and 22 are advanced and retracted with respect to the shank 1, but the shank 1 may be advanced and retracted with respect to the collets 2 and 22.

  It should be noted that the amount of the collets 2 and 22 protruding outward from the outer peripheral surface of the collets 2 and 22 can be freely changed, and the amount is as shown by the broken line in FIG. It can be set as long as the protrusion amount is such that the excessive deformation of 3 is not caused. In this way, by extending the gripping portions 3 and 23 outward by a necessary amount and selectively using several collets 2 and 22 having different protrusion amounts, the range of the diameter of the work W that can be handled is further widened. It can be of a range.

The method of fixing the shank 1 and the attachment sleeve 12 is such that the bolt 14 is inserted into the hole 13 parallel to the axial direction of the sleeve 12 and screwed into the wall surface 37 to press the sleeve 12 against the wall surface 37 as in this embodiment. However, the fixing method is not limited. For example, as shown in FIG. 4, a screw having a hollow type tip is screwed inward in the radial direction of the attachment sleeve 12, and the screw tip is fixed. You may use it so that the cross-section triangle tip may fit in the hollow of the same cross-sectional triangle provided in the shank 1 surrounding surface.
For example, when the sleeve 12 indicated by the solid line in the drawing is slightly displaced forward, the central axis of the screw is positioned slightly forward (right side in the drawing) with respect to the central axis of the recess. By tightening the screw and screwing it in the direction of the arrow, the sleeve 12 comes into close contact with the cylindrical surface 36, and the rear surface 17 of the sleeve 12 faces toward the wall surface 37 (left side in the drawing) as shown by a chain line in the drawing. The two can be fixed in close contact with each other.

  The sleeve 12 is fixed to the shank 1, as in this embodiment, the tapered surface 1a of the shank 1 and the inner tapered surface 12a of the sleeve 12 are in close contact, and the rear surface 17 of the sleeve 12 is attached to the wall surface 37. Although it is desirable in terms of stability that the inner cylindrical surface 15 of the sleeve 12 is in close contact with the cylindrical surface 36, the tapered surface 1a and the taper surface 1a can be used as long as both the positioning means and the means capable of maintaining stable fixation are provided. The inner tapered surface 12a of the sleeve 12, the wall surface 37 and the rear surface 17 of the sleeve 12, or the cylindrical surface 36 and the inner cylindrical surface 15 of the sleeve 12 may not be in close contact with each other.

1 shows an embodiment, (a) is a cross-sectional view, (b) is a side view. 1 is an exploded view of the main part of FIG. In the embodiment of FIG. 1, the case where an attachment sleeve is not used is shown, (a) is a sectional view, (b) is a side view. The principal part enlarged view of other embodiment It is explanatory drawing of an effect | action of a prior art example, (a) is a small diameter workpiece | work, (b) is sectional drawing corresponding to a large diameter workpiece | work.

Explanation of symbols

1 Shank 1a Tapered surface (Shank tapered surface)
1b Cylindrical surface (shank cylindrical surface)
2 Collet 2a Collet taper surface 3, 23 Grip part 4, 24 Split groove 5, 25 Stopper 6, 26 Collet cylindrical surface 7, 27 Flange 8, 28 Hole 9, 29 Bolt 10, 20 Chuck body 12 Attachment sleeve 12a Inner taper surface 12b outer tapered surface 13 hole 14 bolt 15 inner cylindrical surface 16 outer cylindrical surface 17 rear surface 22 sub collet 22a sub collet tapered surface 30 rear wall 31 base 32 through hole 33, 34 screw hole 35 cylinder 36, 38 cylindrical surface 37 wall surface 39 advance / retreat Board

Claims (1)

A collet opening / closing shank 1 is provided on the chuck body 10, and a collet 2 is concentrically fitted to the shank 1 so as to be detachable, and an outer peripheral surface of the tip end of the shank 1 is formed as a tapered surface 1 a toward the outside, and the shank of the collet 2 An inner peripheral surface fitted to one tapered surface 1a is also a tapered surface 2a corresponding to the tapered surface 1a, and the shafts of both tapered surfaces 1a, 2a due to relative advancement and retraction of the shank 1 and the collet 2 in the axial direction are used. In a collet chuck device that opens and closes the collet 2 due to a deviation in direction,
An attachment sleeve 12 can be detachably fitted and fixed to the shank 1 in a concentric manner, and a sub-collet 22 different from the collet 2 can be fitted to the attachment sleeve 12 concentrically. And the inner peripheral surface of the sub-collet 22 fitted to the outer peripheral surface thereof are tapered surfaces 12a, 22a having the same taper as both the tapered surfaces 1a, 2a of the shank 1 and the collet 2 ,
A radial wall surface 37 is provided on the rear outer peripheral surface of the shank 1, and the rear surface 17 of the attachment sleeve 12 is brought into contact with the wall surface 37 to position the attachment sleeve 12 in the axial direction. A cylindrical surface 36 is provided behind the tapered surface 1a, and the inner peripheral surface of the attachment sleeve 12 is in contact with the tapered surface 1a of the shank 1 and the cylindrical surface 36 to fix the attachment sleeve 12 to the shank 1. collet chuck device shall be the features.

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