JP2015174181A - Fixing member of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collet of a machine tool which inhibits plastic deformation and damage in a state where the collet does not hold a workpiece.SOLUTION: A collet 30 includes: a body part 31 to which a workpiece is fixed; and a deformation restriction ring 52 which restricts deformation of the body part 31. The body part 31 includes a protruding part 31c formed at an outer periphery part of an end surface. The deformation restriction ring 52 includes a contact part 52a disposed at the inner side of the protruding part 31c. The protruding part 31c contacts with the contact part 52a when the body part 31 deforms and a diameter of an area enclosed by the protruding part 31c becomes a predetermined value.

Description

  The present invention relates to a fixing member that is disposed on a machine tool and fixes an object to be held.

  A machine tool can process a workpiece into various shapes by moving a tool, a grindstone, or the like relative to the workpiece. When machining a workpiece with a machine tool, the tool, workpiece or grindstone can be held by a holding device such as a chuck device. As the holding device, it is known to use a collet in which the diameter of an insertion hole into which a tool or the like is inserted changes.

  The collet is formed in a cylindrical shape and has a plurality of slits extending in the axial direction. The slit is formed at the end on the side where a tool or the like is inserted. By forming the slit, the end of the collet is divided into a plurality of parts. When the end of the collet is pressed in the radial direction from the outside, the inner diameter of the insertion hole of the collet becomes small, and the tool or the like inserted into the insertion hole can be fixed.

  For example, Patent Document 1 discloses a tool holder in which a tapered portion is formed on a collet bush and presses the collet bush inward. In this tool holder, when the nut is tightened, the collet bush is pressed inward via the collet holder to fix the tool.

  In a normal collet, a slit formed at an end where a tool or the like is inserted extends to the end surface of the collet. That is, the end face of the collet is divided into a plurality of parts by the slits. On the other hand, Non-Patent Document 1 discloses a collet in which an end surface is integrally formed without a slit reaching the end surface of the collet. In this collet, it is disclosed that an oil passage is formed inside the collet and the tool is pressed and fixed by hydraulic pressure.

Japanese Utility Model Publication No. 6-50712

Shunk Japan Co., Ltd., catalog “SCHUNK TENDO E compact”, September 2010, p. 8-p. 9

  When the end of the collet is pressed in the radial direction, the inner surface of the insertion hole at the end of the collet comes into contact with the object to be held in a state where the object to be held such as a tool is mounted. For this reason, the insertion hole at the end of the collet is maintained at a predetermined inner diameter. However, in a state where the object to be held is not attached to the collet, when the end of the collet is pressed from the outside, the parts divided by the slits come into contact with each other, and the end of the collet is plastically deformed or damaged. There is a risk of doing. Therefore, in the conventional holding device, for example, a stopper that restricts the movement of the draw bar that pulls the collet is disposed.

  Moreover, when fixing a to-be-held object to a collet, it is preferable to position a to-be-held object correctly. For example, when the object to be held rotates, it is preferable to accurately align the center axis of the object to be held with the rotation axis. In the collet in which the end surface is integrally formed without the slit reaching the end surface, the shape of the insertion hole on the end surface is constant, so that the positioning accuracy of the object to be held can be improved. However, in the collet having the end face formed integrally, if the end is pressed without the object to be held attached, a large stress is applied to the end where the slit is not formed, and plastic deformation may occur. There is a problem that it is easily damaged.

  An object of this invention is to provide the fixing member of the machine tool which suppresses plastic deformation and breakage in the state which is not holding the to-be-held object.

  The fixing member of the machine tool of the present invention is a fixing member that is disposed in the holding device of the machine tool and fixes the object to be held, has a slit and an insertion hole for inserting the object to be held, and is pressed from the outside. And a main body for fixing the object to be held with the inner diameter of the insertion hole being reduced, and a deformation limiting ring for restricting deformation of the main body. The main body portion includes a protruding portion that protrudes from the end surface on the side where the object to be held is inserted and has an insertion hole therein, and a convex portion that is formed on the outer peripheral portion of the end surface and extends in the circumferential direction. The deformation limiting ring includes a contact portion disposed inside the convex portion. The contact portion has an outer diameter that restricts deformation of the main body portion when the main portion is deformed and the diameter of the region surrounded by the convex portion reaches a predetermined size.

  In the above invention, the protrusion may have a structure in which the slit is not extended to the end face of the protrusion and the tip is connected in the circumferential direction.

  In the above invention, the insertion hole has a first inclined portion whose inner diameter gradually decreases from the end face of the projecting portion, and a second inclined portion whose inner diameter gradually increases continuously from the first inclined portion. be able to.

  In the above invention, the deformation limiting ring has a shape that protrudes laterally from the contact portion, and can include a cover portion that covers the end surface of the convex portion.

  According to the present invention, it is possible to provide a fixing member for a machine tool that suppresses plastic deformation and breakage in a state in which an object to be held is not held.

1 is a schematic perspective view of a machine tool in an embodiment. It is a schematic sectional drawing of the workpiece spindle head in embodiment. It is a general | schematic disassembled perspective view of the collet in embodiment. It is an expansion schematic sectional drawing of the part of the front-end | tip of the workpiece spindle head in embodiment. It is an expanded sectional view of the tip part of a collet in an embodiment. It is another expanded sectional view of the front-end | tip part of the collet in embodiment.

  With reference to FIG. 1 to FIG. 6, the fixing member of the machine tool in the embodiment will be described. In the present embodiment, a tool grinder for manufacturing a tool such as a drill or an end mill will be described as an example of a machine tool. A numerically controlled machine tool that automatically processes a workpiece based on a machining program will be described as an example.

  FIG. 1 is a schematic perspective view of a machine tool in the present embodiment. The machine tool 10 includes a bed 11 installed on a floor surface of a factory or the like. The machine tool 10 includes a column 13 erected from the upper surface of the bed 11. The column 13 is supported on the bed 11 via the Y-axis slide base 12. A grindstone head 18 for rotating the rotating grindstone 5 is disposed on the front surface of the column 13. The grinding wheel head 18 is supported by the column 13 via the Z-axis slide base 14.

  The machine tool 10 includes a workpiece spindle head 20 that holds the workpiece 1. The machine tool 10 includes a swivel base 17 that supports a workpiece spindle head 20 so as to be rotatable around a W axis. The swivel base 17 is supported on the bed 11 via the X-axis slide base 16.

  The machine tool 10 includes a moving device that moves the rotating grindstone 5 relative to the workpiece 1. The X-axis slide base 16 is formed to be movable in the X-axis direction indicated by an arrow 91 by a ball screw mechanism. The swivel base 17 and the work spindle head 20 are formed to be movable in the X-axis direction. The Y-axis slide base 12 is formed to be movable in the Y-axis direction indicated by an arrow 92 by a ball screw mechanism. The column 13, the grindstone head 18 and the rotating grindstone 5 are formed to be movable in the Y-axis direction. The Z-axis slide base 14 is formed to be movable in the Z-axis direction indicated by an arrow 93 by a ball screw mechanism. The grindstone head 18 and the rotating grindstone 5 are formed to be movable in the Z-axis direction.

  Further, the moving device can rotate the work spindle head 20 and the work 1 in the W-axis direction by rotating the swivel base 17. Furthermore, the workpiece spindle head 20 can rotate the workpiece 1 in the A-axis direction.

  As described above, the moving device of the machine tool 10 according to the present embodiment performs relative movement by using the three linear motion shafts and the two rotary feed shafts. Machine tool 10 of the present embodiment includes a control device. A moving device that performs relative movement in each axial direction is controlled by a control device. A rotating machine such as a motor is disposed inside the grinding wheel head 18, and the rotating wheel 5 can be rotated by driving the rotating machine.

  The machine tool 10 can grind the workpiece 1 while moving the rotary grindstone 5 relative to the workpiece 1. As a result, the workpiece 1 can be ground into a desired shape. In addition, as a machine tool, it is not restricted to this form, Arbitrary machine tools, such as a machine tool which performs cutting, and an electric discharge machine, are employable.

  In the present embodiment, a workpiece spindle head 20 will be described as an example of a machine tool holding device. The object to be held is a work 1. The workpiece spindle head 20 in the present embodiment is formed so that the rod-shaped workpiece 1 can be attached and detached.

  FIG. 2 shows a schematic cross-sectional view of the workpiece spindle head in the present embodiment. The work spindle head 20 includes a spindle 33 that rotates while supporting the work 1, and a housing 34 that is formed to cover the spindle 33.

  The spindle 33 is formed in a cylindrical shape and is rotatably supported by the housing 34. The rotation axis of the spindle 33 corresponds to the rotation center line of the A axis (see FIG. 1). One end of the spindle 33 is supported by the housing 34 via bearings 44a and 44b. The other end of the spindle 33 is supported by the housing 34 via a bearing 44c.

  The work spindle head 20 of the present embodiment includes a built-in type rotating machine. A stator 41 is disposed on the inner surface of the housing 34. A rotor 42 is disposed on the outer surface of the spindle 33. The stator 41 and the rotor 42 constitute a rotating machine.

  The work spindle head 20 includes a collet 30 as a fixing member for fixing the work 1 and an adapter 32 for fixing the collet 30 to the spindle 33. A plurality of slits extending in the direction of the central axis of the collet 30 are formed at the end of the collet 30 that holds the work 1. The collet 30 holds or opens the workpiece 1 by changing the inner diameter of the insertion hole 31b into which the workpiece 1 is inserted. The collet 30 is formed with a fitting portion 31a whose outer diameter gradually changes.

  A pull stud 35 is fixed to the end of the collet 30 opposite to the end where the work 1 is inserted. The adapter 32 is disposed between the collet 30 and the spindle 33. The adapter 32 has a cylindrical portion 32d formed in a cylindrical shape, and a collar portion 32b that protrudes outward from the cylindrical portion 32d. The cylindrical portion 32 d of the adapter 32 has an insertion hole 32 f into which the collet 30 is inserted. Bolts 51 are arranged in the region of the collar portion 32b. The adapter 32 is fixed to the spindle 33 by a bolt 51. The adapter 32 is formed with a fitting portion 32a in which the inner diameter of the insertion hole 32f gradually changes.

  A draw bar 37 extending along the rotation axis of the spindle 33 is arranged inside the spindle 33. A spring 43 is disposed around the draw bar 37. An engaging claw 36 is engaged with the draw bar 37. A plurality of engaging claws 36 are arranged in the circumferential direction. Further, the engaging claw 36 engages with the pull stud 35.

  The work spindle head 20 includes a pressing device that presses the end of the collet 30 from the outside in the radial direction. The pressing device includes a draw bar 37 and a spring 43 that biases the draw bar 37 in the direction indicated by the arrow 94. The engaging claw 36 is pulled in the direction indicated by the arrow 94 by the biasing force of the spring 43. The engaging claw 36 is urged in the direction in which the end portion closes and engages with the pull stud 35. Then, the pull stud 35 and the collet 30 are biased toward the side that is drawn into the spindle 33. As a result, the fitting part 31 a of the collet 30 is pressed against the fitting part 32 a of the adapter 32. That is, the fitting part 31a of the collet 30 is pressed toward the central axis. The inner diameter of the insertion hole 31b of the collet 30 is reduced, and the work 1 can be fixed. The workpiece 1 held by the collet 30 rotates integrally with the spindle 33.

  The work spindle head 20 includes a drive device that drives the draw bar 37. The drive device of this embodiment is driven by hydraulic pressure. The drive device includes a piston 38. Around the piston 38, oil chambers 39a and 39b into which pressurized control oil is injected are formed. When processing the workpiece 1, the control oil is supplied to the oil chamber 39b. The pressing of the draw bar 37 by the piston 38 is avoided.

  On the other hand, when the workpiece 1 is removed, the pressurized control oil is supplied to the oil chamber 39a. The piston 38 moves in the direction indicated by the arrow 95. Then, the draw bar 37 is pressed, and the pull stud 35 and the collet 30 are pressed outward along the axial direction. As a result, the pressing of the fitting portion 31a of the collet 30 by the fitting portion 32a of the adapter 32 is released. The inner diameter of the insertion hole 31b of the collet 30 is increased, and the workpiece 1 can be removed.

  FIG. 3 shows a schematic exploded perspective view of the collet of the present embodiment. The collet 30 includes a cylindrical main body 31 in which a fitting portion 31 a is formed, and a deformation limiting ring 52 disposed on one end surface of the main body 31. The end on the side where the workpiece 1 is inserted has a slit 31h cut at a predetermined width. The slit 31 h extends along the axial direction of the main body 31. The slits 31h are formed with a predetermined interval. As for the main-body part 31, the area | region in which the slit 31h is formed elastically deforms.

  The main body 31 has a protruding portion 31d that protrudes from the end surface on the side where the workpiece 1 is inserted. The protrusion 31d of the present embodiment is formed in a cylindrical shape. The main body 31 has a convex portion 31c formed on the end surface on the side where the workpiece 1 is inserted. The convex portion 31 c is formed on the outer peripheral portion of the end surface of the main body portion 31. The convex portion 31 c extends along the circumferential direction of the end surface of the main body portion 31. A recess is formed between the protrusion 31d and the protrusion 31c.

  The deformation restriction ring 52 is a member that restricts deformation of the region of the main body 31 where the slit 31 h is formed. The deformation limiting ring 52 is attached to the main body 31 with the hole 52c inserted into the protruding portion 31d. The deformation limiting ring 52 has a contact portion 52a. The abutting portion 52a is disposed in a recess formed between the protruding portion 31d and the protruding portion 31c of the main body portion 31.

  FIG. 4 shows an enlarged schematic cross-sectional view of the tip portion of the collet of the holding device of the present embodiment. The hole 52c of the deformation limiting ring 52 is fitted in the protruding portion 31d. An O-ring 53 is disposed around the protrusion 31d in order to prevent the deformation limiting ring 52 from coming off the protrusion 31d.

  An insertion hole 31b for inserting the workpiece 1 is formed in the protrusion 31d of the main body 31. A slit 31h is also formed in the protruding portion 31d. Here, the slit 31h is interrupted without extending to the end face of the protruding portion 31d. The protrusion 31d has a tip 31j connected in the circumferential direction. That is, the tip 31j of the collet for inserting the workpiece 1 is integrally formed without being divided. Thus, the protrusion 31d has a structure in which the tip is closed.

  In a state where the fitting portion 31a of the collet 30 is not pressed against the fitting portion 32a of the adapter 32, the contact portion 52a of the deformation limiting ring 52 is a portion of the outer diameter d1 surrounded by the convex portion 31c of the main body portion 31. It is formed to be smaller than the diameter d2. For this reason, a gap is formed between the contact portion 52a and the convex portion 31c. Even when the workpiece 1 is mounted, a gap is formed between the contact portion 52a and the convex portion 31c.

  Referring to FIGS. 2 and 4, even when workpiece 1 is not inserted into collet 30, collet 30 is biased in the direction indicated by arrow 94 by the action of spring 43. When the fitting portion 31a of the main body 31 is pressed, the region of the main body 31 where the slit 31h is formed is elastically deformed. A force acts on the protruding portion 31d in such a direction that the inner diameter of the insertion hole 31b decreases. The convex portion 31 c is deformed toward the central axis of the main body portion 31 as indicated by an arrow 96. At this time, since the tip 31j of the protrusion 31d has an integral structure, the amount of deformation is large and a large stress is generated inside.

  In the present embodiment, the convex portion 31c of the main body portion 31 contacts the contact portion 52a of the deformation limiting ring 52 before a large internal stress is applied to the tip portion 31j of the protruding portion 31d. The deformation of the main body 31 is limited by the protrusion 31c coming into contact with the contact part 52a. The deformation of the protruding portion 31d is also limited. For this reason, it is possible to avoid applying excessive force to the tip 31j of the protruding portion 31d.

  Thus, in the collet 30 of the present embodiment, when the diameter of the portion surrounded by the convex portion 31c reaches a predetermined value, the convex portion 31c comes into contact with the abutting portion 52a, and the main body portion 31. Limit deformation. The deformation limiting ring 52 can prevent the tip portion 31j of the protruding portion 31d from being plastically deformed or damaged in a state where the workpiece 1 is not mounted.

  Referring to FIG. 2, a stopper 45 that limits the amount of movement of the draw bar 37 is disposed on the workpiece spindle head 20. When the collet 30 is pulled by a predetermined movement amount with the workpiece 1 removed, the movement of the draw bar 37 can be stopped by the stopper 45. For this reason, the distance by which the collet 30 is drawn by the stopper 45, that is, the force pressing the fitting portion 31a by the fitting portion 32a can be adjusted. However, each time the collet 30 is replaced, it is necessary to adjust the position of the stopper 45, which is troublesome. On the other hand, in the collet 30 of the present embodiment, it is only necessary to adjust the size of the deformation limiting ring 52 when the collet 30 is manufactured, and adjustment of a stopper or the like when replacing the collet 30 becomes unnecessary. Further, even if the position of the stopper 45 is incorrectly adjusted, it is possible to suppress plastic deformation and breakage of the collet.

  In FIG. 4, the difference between the diameter d2 of the region surrounded by the convex portion 31c and the outer diameter d1 in the circumferential direction of the contact portion 52a of the deformation limiting ring 52 is exaggerated. In a state where the workpiece 1 is removed, the gap between the convex portion 31c and the contact portion 52a is, for example, a slight gap of about 0.05 mm formed as a clamping allowance. The deformation limiting ring 52 may limit the movement of the convex portion 31c so that the tip portion 31j of the protruding portion 31d is not plastically deformed or damaged, and the tip portion 31j may be elastically deformed.

  The deformation limiting ring 52 of the present embodiment has a cover portion 52 b that covers the end surface of the convex portion 31 c of the main body portion 31. The cover part 52b has a shape that protrudes laterally from the contact part 52a. The cover part 52b protruding in the radial direction is formed so as to cover the gap between the convex part 31c and the contact part 52a.

  In the collet 30 of the present embodiment, when the workpiece 1 is mounted, a gap is formed between the convex portion 31c and the contact portion 52a. In some cases, foreign substances such as grinding fluid, cemented carbide cutting powder, and sludge enter. In particular, foreign matter may enter the work spindle head 20 through the slit 31h. If foreign matter enters the sliding surface inside the work spindle head 20, the constituent members of the work spindle head 20 may slide and wear. In addition, the centering accuracy of the workpiece 1 may be affected.

  For example, the foreign matter that has entered the inside of the collet 30 may enter the boundary portion between the fitting portion 31a of the collet 30 and the fitting portion 32a of the adapter 32 through the slit 31h. When the workpiece 1 is fixed and released, the fitting portion 31a and the fitting portion 32a slide with each other. For this reason, there exists a possibility that the sliding part of the fitting part 31a and the fitting part 32a may wear. On the other hand, by providing the deformation limiting ring 52 with the cover 52b as in the collet 30 of the present embodiment, foreign matter can be prevented from entering the work spindle head 20. It can suppress that the structural members of the work spindle head 20 slide and wear. Moreover, the deterioration of the centering accuracy of the workpiece 1 can be suppressed.

  In the tip portion 31j of the protruding portion 31d of the present embodiment, the slit 31h does not extend to the end surface but is connected in the circumferential direction. In such a collet 30, since a large stress is applied to the tip portion 31j when the main body portion 31 is deformed, the effect of suppressing plastic deformation and breakage of the tip portion 31j becomes remarkable. The protrusion 31d of the main body 31 is not limited to this form, and the slit 31h may be formed up to the end surface into which the workpiece 1 is inserted. That is, the tip end 31j of the protrusion 31d may be divided into a plurality of parts. Even in such a collet, by arranging the deformation limiting ring, it is possible to suppress the tip portion of the protruding portion from being plastically deformed or damaged without using a stopper.

  FIG. 5 shows an enlarged schematic cross-sectional view of the tip of the protruding portion of the collet of the present embodiment. The tip part 31j of the protruding part 31d has a structure in which the slit 31h is not formed up to the end face. For this reason, the shape of the insertion slot into which the workpiece 1 is inserted is maintained constant, and the positioning accuracy of the center axis 62 of the workpiece 1 is improved. However, when trying to insert the workpiece 1 with the central axis 62 of the workpiece 1 tilted with respect to the central axis 61 of the collet 30, the insertion of the workpiece 1 may be hindered. As a result, it may take time for the operator to insert the workpiece 1 into the collet 30.

  In the collet 30 of the present embodiment, the insertion hole 31b of the protruding portion 31d has a first inclined portion 31e that gradually decreases in inner diameter along the axial direction from the end surface of the protruding portion 31d. The insertion hole 31b has a second inclined portion 31f that is continuous with the first inclined portion 31e and has an inner diameter that gradually increases along the axial direction. A top portion 31i is formed at the boundary between the first inclined portion 31e and the second inclined portion 31f. Moreover, the insertion hole 31b has the 3rd inclination part 31g which becomes continuous with the 2nd inclination part 31f, and an internal diameter becomes small gradually along an axial direction. Each inclined portion 31 e, 31 f, 31 g is inclined with respect to the central axis 61 of the collet 30. The insertion hole 31b has a supporting portion 31k for supporting the workpiece 1 on the inner side of a region where such inclined portions are continuous. The supporting portion 31k has no inclined portion and has an almost constant inner diameter.

  When the work 1 is inserted into the insertion hole 31b as indicated by the arrow 97, the center axis 62 of the work 1 may be inclined with respect to the center axis 61 of the collet 30. Even if the central axis 61 and the central axis 62 of the workpiece 1 are parallel, the position may be shifted. In any case, the tip of the workpiece 1 can be guided into the insertion hole 31b by the tip of the workpiece 1 coming into contact with the first inclined portion 31e. In particular, the tip of the work 1 can be guided to the inside from the top 31i.

  FIG. 6 shows another enlarged schematic cross-sectional view of the tip of the protruding portion of the collet of the present embodiment. When the workpiece 1 is further inserted, the second inclined portion 31f is formed so that the insertion of the workpiece 1 can be continued even if the center axis 62 of the workpiece 1 is inclined with respect to the center axis 61. it can. When the tip of the workpiece 1 comes into contact with the third inclined portion 31g, the tip of the workpiece 1 can be guided to the carrying portion 31k of the insertion hole 31b along the third inclined portion 31g. The inclination of the workpiece 1 is corrected, and the workpiece 1 can be inserted into the insertion hole 31b to a predetermined depth.

  Thus, in the collet 30 of the present embodiment, when the center axis 62 of the workpiece 1 is inserted with the center axis 61 tilted with respect to the center axis 61 of the protruding portion 31d, the workpiece 1 is moved while correcting the tilt. It can be inserted into the insertion hole 31b. Even when the center axis 62 of the workpiece 1 is tilted with respect to the center axis 61 of the projecting portion 31d, or when the position is shifted even if it is almost parallel, the workpiece 1 can be easily inserted while correcting the tilt and the position shift. It can be inserted into the hole 31b.

  The machine tool may include an exchange device that automatically exchanges the object to be held. For example, the machine tool may include a workpiece exchange device that automatically exchanges the workpiece 1. The workpiece changer can pull out or insert the workpiece 1 from the collet 30. In the prior art, when a workpiece is exchanged by a workpiece exchange device using a collet whose tip is closed, there is a high probability that the workpiece insertion will fail. For this reason, it has been substantially impossible to automatically change the workpiece. On the other hand, by adopting the collet of the present embodiment as the workpiece spindle head, the probability of succeeding in the insertion of the workpiece by the workpiece exchange device is significantly improved. As a result, the workpiece can be automatically changed by the workpiece changing device.

  Here, if the inclination angle θ1 of the first inclined portion 31e with respect to the central axis 61 of the collet 30 is too small, the position shift is caused when the position of the central axis 62 of the workpiece 1 is shifted from the central axis 61 of the protruding portion 31d. The range that can be corrected becomes smaller. On the other hand, if the inclination angle θ1 is too large, the tip of the workpiece 1 can be smoothly slid on the first inclined portion 31e and the workpiece 1 cannot be guided into the insertion hole 31b. For example, the inclination angle θ1 is preferably 20 ° or more and less than 45 °. In the present embodiment, the inclination angle θ1 is set to 30 °.

  The inclination angle θ2 formed by the second inclined portion 31f and the central axis 61 is preferably smaller than the inclination angle θ1. The inclination angle θ2 is preferably 10 ° or more and less than 30 °, for example. The inclination angle θ2 of the present embodiment is set to 15 °.

  Moreover, it is preferable that the connection part of the 1st inclination part 31e and the 2nd inclination part 31f, ie, the top part 31i, is not a sharp corner | angular part but a curved surface shape. That is, it is preferable that the top portion 31i has an arc shape in cross section. With this configuration, the workpiece 1 can be smoothly inserted into the interior from the top portion 31i.

  The inclination angle θ3 formed by the third inclined portion 31g and the central axis 61 is smaller than the inclination angle θ1 and the inclination angle θ2 so that the inclination of the work 1 is gradually corrected and the work 1 slides smoothly. It is preferable. For example, the inclination angle θ3 is preferably 4 ° or more and less than 10 °. In the present embodiment, the inclination angle θ3 is set to 6 °.

  The diameter d3 of the part surrounded by the top part 31i can be formed larger than the diameter d4 of the supporting part 31k to which the workpiece 1 is substantially fixed. For example, when the diameter of the workpiece 1 is 6.0 mm, the diameter d4 can be set to about 6 mm so that the workpiece 1 can be fitted. On the other hand, the diameter d3 can be set to 6.1 mm. The diameter d3 is larger than the major axis of the ellipse having a cross-sectional shape when the workpiece 1 is cut along a plane perpendicular to the central axis 61 when the inclination of the central axis 62 of the workpiece 1 is inserted at an inclination angle θ2 or less. Is preferred.

  In the collet of the present embodiment, the end of the collet is pressed by the fitting part of the main body part coming into contact with the fitting part of the adapter, but the collet is not limited to this form. The end of the fixing member to which the object to be held is attached can be pressed from the outside.

  In the present embodiment, the fixing member of the holding device that holds the workpiece as the object to be held has been described as an example. However, the present invention is not limited to this configuration, and the fixing member of the holding device that holds the tool or the rotating grindstone is also described. The invention can be applied. For example, the fixing member of the present invention can be arranged in a spindle device that holds a tool such as an end mill. Or when a machine tool is provided with the tool change apparatus which changes a tool, the fixing member of this invention can be employ | adopted for a tool change apparatus. Or when providing the workpiece | work exchange apparatus which replace | exchanges a workpiece | work, the fixing member of this invention can be arrange | positioned at a workpiece | work exchange apparatus.

  The above embodiments can be combined as appropriate. In the respective drawings described above, the same or equivalent parts are denoted by the same reference numerals. In addition, said embodiment is an illustration and does not limit invention. Further, in the embodiment, changes of the embodiment shown in the claims are included.

DESCRIPTION OF SYMBOLS 1 Work 10 Machine tool 20 Work spindle head 30 Collet 31 Main part 31b Insertion hole 31c Protrusion part 31d Protrusion part 31e, 31f, 31g Inclination part 31h Slit 31j Tip part 52 Deformation | restriction ring 52a Contact part 52b Cover part 61,62 Center Shaft d1 outer diameter d2 diameter

Claims (4)

A fixing member that is arranged in a holding device of a machine tool and fixes an object to be held,
A main body portion that has a slit and an insertion hole for inserting the object to be held, and when pressed from the outside, the inner diameter of the insertion hole is reduced to fix the object to be held;
A deformation limiting ring for limiting deformation of the main body,
The main body portion includes a protruding portion that protrudes from an end surface on the side where the object to be held is inserted and has the insertion hole therein, and a convex portion that is formed on the outer peripheral portion of the end surface and extends in the circumferential direction.
The deformation limiting ring includes an abutting portion disposed inside the convex portion,
The contact portion has an outer diameter that restricts deformation of the main body portion when the main body portion is deformed and the diameter of the region surrounded by the convex portion reaches a predetermined size. A machine tool fixing member.   2. The fixing member for a machine tool according to claim 1, wherein the protruding portion has a slit that does not extend to an end surface of the protruding portion and a tip portion is connected in a circumferential direction.   The insertion hole has a first inclined portion whose inner diameter gradually decreases from an end surface of the projecting portion, and a second inclined portion whose inner diameter gradually increases continuously from the first inclined portion. The fixing member of the machine tool of 2.   The fixing member for a machine tool according to any one of claims 1 to 3, wherein the deformation limiting ring has a shape projecting laterally from the contact portion, and includes a cover portion that covers an end surface of the convex portion.

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