JP6527071B2 - Machine tool holder - Google Patents

Description

  The present invention relates to a machine tool holder having a holding portion that holds a gripped member such as a tool or a work, and in particular, suppresses movement of the gripped member along the circumferential direction and the axial direction with respect to the holding portion. It relates to technology.

  The machine tool has a holder for gripping a gripped member (tool or work). The holder has a holding portion, and the member to be held is inserted directly or through a collet into an insertion space formed by the inner circumferential surface of the holding portion. Here, during the processing operation, the gripped member held by the holding unit may move along the circumferential direction (rotational direction) or the axial direction with respect to the holding unit. For example, due to cutting resistance at the time of cutting, the cutting tool may slip in the rotational direction and may slip out from the tip end along the axial direction or may be pushed toward the rear end. Then, the tool holder which suppressed that a to-be-held member moves along the circumferential direction and axial direction with respect to a holding | maintenance part is proposed (refer patent document 1). In the conventional tool holder disclosed in Patent Document 1, a long groove extending in the axial direction is formed on the inner peripheral surface of the holding portion, and a long diameter larger than the width of the long groove is formed on the tip end of the long groove. A retaining hole is formed.

Unexamined-Japanese-Patent No. 2006-26830

The conventional holder for a machine tool can suppress movement of the gripped member along the circumferential direction and the axial direction with respect to the holding portion. However, there is a limit in enhancing the effect of suppressing movement of the gripped member along the circumferential direction and the axial direction with respect to the holding portion.
The present invention has been made in view of such a point, and provides a technique capable of effectively suppressing movement of the gripped member relative to the holding portion along the circumferential direction and the axial direction. The purpose is to

The holder for a machine tool of the present invention is provided with a holding portion for holding a member to be held such as a tool or a work. The holding portion has a holding portion inner circumferential surface which forms a first insertion space inside, and a pressing area which receives a pressing force for reducing the diameter of the holding portion inner circumferential surface. Preferably, the holding portion is a cylindrical sleeve having a sleeve inner peripheral surface (corresponding to "holding portion inner peripheral surface") forming a first insertion space inside and a sleeve outer peripheral surface, and a sleeve into which the sleeve is inserted It is comprised by the main-body part which has a main-body part inner peripheral surface which forms insertion space inside. "Pressing region" indicates a region of the holding portion that receives a pressing force that causes the diameter of the inner circumferential surface of the holding portion to be reduced. For example, when the holding portion is constituted by the main body portion and the sleeve, and a pressurized space into which the pressurized medium is injected is formed between the inner circumferential surface of the main body portion and the sleeve outer circumferential surface, the pressurized space is formed. The part of a sleeve outer peripheral surface is shown. The diameter of the inner circumferential surface of the holding portion is reduced by the pressure applied to the pressure area, whereby the gripped member inserted in the first insertion space is gripped.
In the present invention, at least two pressing regions are provided along the axial direction.
A first groove (longitudinal groove) extending along the axial direction and a second groove (circumferential groove) extending along the circumferential direction are formed on the inner circumferential surface of the holding portion. The first groove is formed at a position corresponding to one of the at least two pressure regions, and the second groove is formed at a position corresponding to the other pressure region. The “location corresponding to the pressing region” indicates a region obtained by projecting the pressing region along the radial direction on the inner circumferential surface of the holding portion. In addition, the description “formed in a portion corresponding to the pressure area” is a configuration in which the first groove (second groove) is formed in at least a part of the portion corresponding to the pressure area. It means that it may be formed over the entire area corresponding to the pressure area or the area corresponding to the pressure area. The shapes (length, width) of the first groove and the second groove are appropriately set. Preferably, a plurality of first grooves are disposed along the circumferential direction, and a plurality of second grooves are disposed along the axial direction. The first groove and the second groove are preferably formed so as not to communicate (spaced along the axial direction), but may be formed to communicate.
In the present invention, the first groove (longitudinal groove) extending along the axial direction and the second groove (circumferential groove) extending along the circumferential direction are respectively separated along the axial direction Since it is formed at a position corresponding to one and the other of the at least two pressure regions, movement (slip) and movement along the axial direction of the gripped member relative to the holding portion It is possible to effectively suppress (disengagement, pushing). Thereby, processing accuracy can be improved.
According to another aspect of the present invention, the first groove and the second groove respectively correspond to a portion of the at least two pressure areas that corresponds to the pressure area disposed on the tip side along the axial direction and the rear side. It is formed in the location corresponding to the pressurization area | region arrange | positioned at the end side. The first groove is preferably formed so as to open at the holding section distal end surface along the axial direction of the holding section, but may not open at the holding section distal end surface.
In this embodiment, the first groove (longitudinal groove) for suppressing movement of the gripped member along the circumferential direction with respect to the holding portion is formed on the tip end side, and the gripped member moves along the axial direction Since the second groove (circumferential groove) for suppressing the movement is formed on the rear end side, movement of the gripped member along the circumferential direction and the axial direction with respect to the holding portion is more effectively suppressed. be able to.
Another different form of the invention comprises a collet inserted into the first insertion space. The collet has a collet inner peripheral surface and a collet outer peripheral surface that form a second insertion space into which the gripped member is inserted. In this embodiment, the diameter of the inner circumferential surface of the holder is reduced by the pressure applied to the pressing area, and the diameter of the inner circumferential surface of the holder is reduced. The diameter of the inner circumferential surface of the collet is reduced. The gripped member inserted into the second insertion space is gripped.
Further, the collet is opened to the outer peripheral surface of the collet, and is a third groove (tip side slit) extending to the rear end side along the axial direction from the collet tip surface on the front end side along the axial direction And a fourth groove (rear end side slit) extending in the axial direction from the rear end collet end surface along the axial direction and along the axial direction Groove). Preferably, the third groove and the fourth groove are formed to communicate the collet inner circumferential surface with the collet outer circumferential surface. By forming the third groove and the fourth groove, the diameter of the collet inner circumferential surface is easily reduced.
In this embodiment, the third groove and the second groove do not communicate with each other when the collet is inserted into the first insertion space. For example, the third groove is configured not to reach the position of the second groove.
As a gripped member to be inserted into the second insertion space formed inside the collet, a hole for a cooling medium is formed at the center side, extending from the rear end side to the front end side along the axial direction. Some held members may be used. In this case, the tip end portion of the gripped member is cooled by the cooling medium that flows out from the tip end side of the gripped member through the first insertion space, the second insertion space, and the hole for the cooling medium formed in the gripped member. (Eg, the cutting edge of the tool) is cooled.
In this embodiment, when the collet is inserted into the first insertion space, the second groove and the third groove are connected even if the fourth groove and the second groove in communication with the rear end face of the collet communicate with each other. The grooves are not in communication. This can prevent the coolant that has entered the second groove from flowing out of the collet tip end surface via the third groove. Therefore, the tip end portion of the gripped member can be properly cooled by the cooling medium that flows out from the tip end side of the gripped member.
In the case where the first groove is open at the end face of the holding portion, it is preferable that the first groove and the second groove are not communicated (are separated along the axial direction). Be done. For example, the length of the first groove in the axial direction from the holding section tip surface is set to be shorter than the shortest distance between the second groove and the holding section tip surface. Thus, the cooling medium that has entered the second groove can be prevented from flowing out of the end face of the holder through the first groove.
In another different mode of the present invention, the fourth groove does not reach the position of the end face of the holding portion when the collet is inserted into the first insertion space (so that the opening does not open at the end face of the holding portion). ) Is configured.
In the present embodiment, the cooling medium can be prevented from flowing out from the end face of the holder through the fourth groove. Thus, when a gripped member having a hole for a cooling medium extending in the axial direction from the rear end side to the front end side is used at the center side, the flowed out from the tip end side of the gripped member The tip of the gripped member can be properly cooled by the cooling medium.
In the case where the first groove is open at the end face of the holder, preferably, the fourth groove and the first groove are in a state in which the collet is inserted into the first insertion space. It is configured not to communicate. For example, the leading end of the fourth groove is configured not to reach the position of the trailing end of the first groove. Alternatively, the collet is inserted into the first insertion space so that the position along the circumferential direction of the fourth groove and the position along the circumferential direction of the first groove do not overlap. Thus, the cooling medium can be prevented from flowing out from the end face of the holder through the fourth groove and the first groove.
In another different form of the present invention, the collet has a communication passage communicating the fourth groove with the collet tip surface. For example, a communication groove formed on the inner circumferential surface of the collet or a communication hole formed in the collet can be used as the communication passage for connecting the fourth groove and the collet tip surface.
As a gripped member to be inserted into a second insertion space formed inside the collet, a gripped member in which a hole for a cooling medium is not formed may be used. In this case, it is necessary to cool the tip of the gripped member by flowing a cooling medium along the outer peripheral surface of the gripped member.
In this embodiment, since the fourth groove communicating with the rear end face of the collet and the communication passage communicating the tip end surface of the collet are provided, the fourth groove for facilitating the diameter reduction of the inner peripheral surface of the collet is It can be used as part of the cooling medium passage. Thereby, when using the to-be-held member in which the hole for cooling media is not formed, the front-end | tip part of a to-be-held member can be cooled by easy structure.

  In the present invention, movement of the gripped member along the circumferential direction and the axial direction with respect to the holding portion can be effectively suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of 1st Embodiment of the holder for machine tools of this invention. It is an II-II arrow line view of FIG. It is an III-III arrow line view of FIG. It is a front view of 2nd Embodiment of the holder for machine tools of this invention. It is a V-V line arrow line view of FIG. FIG. 5 is a view on arrow V-V in FIG. 4 of the collet used in the second embodiment. It is a VII-VII line arrow directional view of FIG. It is a VII-VII line arrow line view of FIG. 4 of the collet used in 2nd Embodiment. FIG. 7 illustrates different embodiments of the collet. FIG. 7 illustrates another embodiment of a collet.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the present specification, the extending direction (x direction shown in FIG. 1) of the holding portion (body portion, sleeve) is referred to as "axial direction". Furthermore, in a cross section orthogonal to the axial direction (FIG. 2), a direction along an arc centered on the rotation center O of the holding portion is called “circumferential direction”, and a direction of a line passing through the rotation center O is “radial direction " Further, along the axial direction, the side into which the tool or the collet is inserted is referred to as the “tip side”, and the side opposite to the side into which the tool or the collet is inserted is referred to as the “rear end side”.

A first embodiment of a machine tool holder according to the present invention will be described with reference to FIGS. The present embodiment is configured as a tool holder for gripping a tool. Of course, the present invention can also be configured as a work holder for holding a work. FIG. 1 is a sectional view along the axial direction of the tool holder 100 of the first embodiment, and FIG. 2 is a sectional view taken along the line II-II in FIG. 1 (a sectional view orthogonal to the axial direction) 3 is a view taken along line III-III in FIG.
The tool holder 100 of the first embodiment has a main body 200 and a sleeve 300. The sleeve 300 is fixed to the main body 200.

The main body portion 200 has a main body portion inner circumferential surface 210. Further, a main body end surface 200a is provided on the front end side (right side in FIG. 1) along the axial direction.
A sleeve insertion space 230 into which the sleeve 300 is inserted is formed by the inner peripheral surface 210 of the main body. The inner peripheral surface 210 of the main body has a circular shape whose center is the rotation center O when viewed in a cross section orthogonal to the axial direction.

The sleeve 300 has a sleeve inner circumferential surface 310 and a sleeve outer circumferential surface 320. Further, a sleeve front end surface 300a is provided on the front end side along the axial direction, and a sleeve rear end surface 300b is provided on the rear end side.
The sleeve inner circumferential surface 310 defines a first insertion space 330. The sleeve inner circumferential surface 310 has a circular shape centering on the rotation center O when viewed in a cross section orthogonal to the axial direction. In the present embodiment, the tool shank portion 510 (see FIG. 5) of the tool 500 is inserted into the first insertion space 330. That is, in the present embodiment, the first insertion space 330 is used as a “tool insertion space”.
The main body portion 200 and the sleeve 300 constitute the “holding portion” of the present invention. Further, the sleeve inner circumferential surface 310 corresponds to the "holding portion inner circumferential surface" of the present invention.

The sleeve outer peripheral surface 320 has a circular shape centering on the rotation center O when viewed in a cross section orthogonal to the axial direction.
A first grip portion outer peripheral surface 321 and a second grip portion outer peripheral surface 322 are formed on the sleeve outer peripheral surface 320 so as to be stepped toward the center of rotation at a location separated in the axial direction. There is. A first pressure space 240 and a second pressure space are formed at locations separated in the axial direction by the first grip outer peripheral surface 321 and the second grip outer peripheral surface 322 of the sleeve outer peripheral surface 320 and the main body inner peripheral surface 210. The pressurized space 250 is formed. In addition, the first grip portion 341 and the first grip portion 341 and the first grip portion outer peripheral surface 321 and the second grip portion outer peripheral surface 322 of the sleeve outer peripheral surface 320 are separated in the axial direction by the sleeve inner peripheral surface 310. A second grip 342 is formed.
In the present embodiment, the outer diameter of the sleeve outer peripheral surface 320 is set to be slightly smaller than the inner diameter of the main body inner peripheral surface 210. Then, after the sleeve 300 is inserted into the sleeve insertion space 230, the sleeve outer peripheral surface 320 is brazed to the main body inner peripheral surface 210. As a result, the sleeve outer peripheral surface 320 is closely fixed to the inner peripheral surface 210 of the main body portion, and the first grip outer peripheral surface 321 and the second outer peripheral surface 322 of the grip portion and the inner peripheral surface 210 of the main body have high sealing performance. And a second pressure space 250 are formed.

A pressurized medium is injected into the first pressurized space 240 and the second pressurized space 250. In the present embodiment, a liquid such as oil is used as the pressurizing medium. A pressure adjustment device is provided to adjust the pressure in the first pressurized space 240 and the second pressurized space 250.
When the pressure in the first pressure space 240 and the second pressure space 250 applied to the first grip outer peripheral surface 321 and the second grip outer peripheral surface 322 increases, the first grip 341 And the second grip 342 (that is, a portion of the sleeve inner circumferential surface 310 corresponding to the first grip 341 and the second grip 342) is elastically deformed to the rotation center O side, and the first grip The inner diameters of 341 and the second grip portion 342 decrease (reduce the diameter). Thus, the tool shank 510 of the tool 500 inserted into the first insertion space 330 is gripped by the first grip 341 and the second grip 342.
When the pressure in the first pressure space 240 and the second pressure space 250 decreases, the first grip portion 341 and the second grip portion 342 return to the shape before elastic deformation, and the first grip portion The gripping of the tool shank 510 by the 341 and the second gripping portion 342 is released.
The first grip portion outer peripheral surface 321 and the second grip portion outer peripheral surface 322 correspond to the “pressure region receiving a pressing force for reducing the diameter of the holding portion inner peripheral surface” of the present invention.

Further, the tool shank portion 510 of the tool 500 gripped by the first grip portion 341 and the second grip portion 342 is provided along the circumferential direction and the axial direction with respect to the sleeve 300 on the sleeve inner circumferential surface 310. A longitudinal groove 340 and a circumferential groove 350 are formed to suppress movement.
The longitudinal groove 340 is formed in the sleeve front end surface 300 a and is formed to extend from the sleeve front end surface 300 a along the axial direction to the rear end side, and the tool shank portion 510 is opposed to the sleeve 300. It acts to suppress movement (slip) along the circumferential direction.
In addition, the circumferential groove 350 is formed to extend along the circumferential direction, so that the tool shank portion 510 can be prevented from moving (disengaging, pushing) in the axial direction with respect to the sleeve 300. Works.

In the present embodiment, the longitudinal groove 340 and the circumferential groove 350 are pressure forces that elastically deform the gripping portions (the first gripping portion 341 and the second gripping portion 342) of the sleeve inner circumferential surface 310 to the rotation center O side. Is formed at the place where it acts. That is, it is formed in the area | region which projected the 1st holding part outer peripheral surface 321 and the 2nd holding part outer peripheral surface 322 on the sleeve inner peripheral surface 310 along radial direction. By forming the longitudinal groove 340 and the circumferential groove 350 at a location where a pressing force that elastically deforms the gripping portion to the rotation center O acts, the tool shank portion 510 moves in the circumferential direction and the axial direction with respect to the sleeve 300 Can be effectively suppressed.
The longitudinal groove 340 and the circumferential groove 350 may be formed at least at a part of the portion corresponding to the pressure area, and are formed over the entire area corresponding to the pressure area or the position corresponding to the pressure area. It may be done.
The region where the grip outer peripheral surface (first grip outer peripheral surface 321, second grip outer peripheral surface 322) is projected onto the sleeve inner peripheral surface 310 along the radial direction corresponds to the “holder inner peripheral surface of the present invention. It corresponds to “a location facing the pressing region (the first grip portion outer peripheral surface 321, the second grip portion outer peripheral surface 322) receiving the pressing force to reduce the diameter.

Furthermore, in the present embodiment, the longitudinal groove 340 is formed at a position corresponding to the first grip portion outer peripheral surface 321 disposed on the tip end side along the axial direction in the sleeve inner peripheral surface 310, The groove 350 is formed at a position corresponding to the second grip outer peripheral surface 322 disposed on the rear end side along the axial direction.
As shown in FIG. 1, the longitudinal groove 340 is opened in the sleeve tip end surface 300a and extends along the axial direction beyond the portion corresponding to the first grip outer peripheral surface 321. ing. Further, as shown in FIG. 2, the vertical grooves 340 are formed at four locations along the circumferential direction.
The circumferential groove 350 is generally formed along the circumferential direction, as shown in FIG. Moreover, as shown in FIG. 1, it is formed in two places along the axial direction.
By forming the longitudinal groove 340 on the tip side in the axial direction and forming the circumferential groove 350 on the rear end side in the axial direction, the tool shank portion 510 extends in the circumferential and axial directions with respect to the sleeve 300. Can be more effectively suppressed.
In the present embodiment, the length A of the longitudinal groove 340 along the axial direction from the sleeve front end surface 300a (body front end surface 200a) is the sleeve front end surface 300a (main body front end surface 200a) and the circumferential groove 350. And so as to be shorter than the minimum distance B between them (to satisfy [B> A]) (see FIG. 1). That is, the longitudinal groove 340 and the circumferential groove 350 are configured to be separated (not in communication) in the axial direction.
The longitudinal groove 340 corresponds to the "first groove" of the present invention, and the circumferential groove 350 corresponds to the "second groove" of the present invention.

Next, a second embodiment of a machine tool holder according to the present invention will be described with reference to FIGS. FIG. 4 is a front view of the second embodiment. 5 is a view taken along the line V-V in FIG. 4, and FIG. 6 is a view taken along the line V-V in FIG. 4 of the collet. 7 is a view taken along the line VII-VII in FIG. 4, and FIG. 8 is a view taken along the line VII-VII in FIG. 4 of the collet.
This embodiment is configured as a tool holder that holds a tool, as in the first embodiment. The tool holder of this embodiment differs from the tool holder of the first embodiment in that the tool is gripped using a collet. 4-8, the component which attached | subjected the code | symbol same as the code | symbol shown by FIGS. 1-3 is the same component.

The tool holder 100 of the present embodiment has a main body 200, a sleeve 300, and a collet 400. The main body portion 200 and the sleeve 300 have the same configuration as the first embodiment, and thus the description thereof is omitted. As in the first embodiment, a longitudinal groove 340 is formed on the tip end side along the axial direction, and a circumferential groove 350 is formed on the rear end side along the axial direction on the sleeve inner peripheral surface 310. There is.
The collet 400 is inserted into the first insertion space 330. That is, in the present embodiment, the first insertion space 330 is used as a "collet insertion space".

The collet 400 has a collet inner circumferential surface 410 and a collet outer circumferential surface 420. Further, a collet front end surface 400a is provided on the front end side along the axial direction, and a collet rear end surface 400b is provided on the rear end side.
The collet inner circumferential surface 410 forms a second insertion space 430. The collet inner circumferential surface 410 has a circular shape whose center is the rotation center O when viewed in a cross section orthogonal to the axial direction. In the present embodiment, the tool shank portion 510 of the tool 500 is inserted into the second insertion space 430. That is, the second insertion space 430 is used as a "tool insertion space".
In the present embodiment, the longitudinal groove 340 acts to suppress movement of the collet 400 having the second insertion space 430 into which the tool shank 510 is inserted relative to the sleeve 300 along the circumferential direction. . The circumferential groove 350 also acts to prevent the collet 400 from moving along the axial direction with respect to the sleeve 300.

The collet outer peripheral surface 420 has a circular shape centering on the rotation center O when viewed in a cross section orthogonal to the axial direction.
The collet outer peripheral surface 420 has an abutting surface 421 extending from the outer peripheral surface 420 in the radial direction to the outer peripheral side. The collet 400 can be inserted into the first insertion space 330 to a position where the abutment surface 421 abuts on the sleeve tip surface 300a.

In addition, the collet 400 is provided with a slit for enabling the diameter of the collet inner circumferential surface 410 to be easily reduced by the pressure applied to the collet outer circumferential surface 420.
In this embodiment, the collet tip end surface 400a is opened, and the tip end side slit groove 440 extending from the collet tip end surface 400a to the rear end side along the axial direction and the collet rear end face 400b are opened along the axial direction. A rear end side slit groove 450 extending from the collet rear end surface 400b to the front end side is formed. The front end side slit groove 440 and the rear end side slit groove 450 communicate the collet inner circumferential surface 410 with the collet outer circumferential surface 420.
In the present embodiment, as shown in FIGS. 4 and 5, the front end side split grooves 440 and the rear end side split grooves 450 are alternately formed at four locations along the radial direction.

In the present embodiment, when the pressure in the first pressure space 240 and the second pressure space 250 applied to the first grip outer peripheral surface 321 and the second grip outer peripheral surface 322 is increased, The first grip portion 341 and the second grip portion 342 (that is, portions of the sleeve inner circumferential surface 310 corresponding to the first grip portion 341 and the second grip portion 342) are elastically deformed to the rotation center O side, The inner diameters of the first grip portion 341 and the second grip portion 342 decrease (reduce the diameter).
The first gripping portion 341 and the second gripping portion 342 of the sleeve 300 elastically deform to the rotation center O side, so that a pressing force in the direction of the rotation center O is applied to the collet outer peripheral surface 420 of the collet 400, and the collet The inner circumferential surface 410 elastically deforms to the rotation center O side. Thereby, the tool shank portion 510 of the tool 500 inserted into the second insertion space 430 is gripped by the collet inner circumferential surface 410.
Here, since the front end side slit groove 440 and the rear end side slit groove 450 are formed in the collet 400, the first grip portion 341 and the second grip portion 342 of the sleeve 300 are elastic toward the rotation center O side. When deformed, the collet inner circumferential surface 410 is easily elastically deformed to the rotation center O side.
When the pressure in the first pressure space 240 and the second pressure space 250 is reduced, the first gripping portion 341 and the second gripping portion 342 of the sleeve 300 return to the shape before elastic deformation. The collet outer peripheral surface 420 and the collet inner peripheral surface 410 of the collet 400 also return to the shape before elastic deformation, and the gripping of the tool shank portion 510 by the collet inner peripheral surface 410 is released.
The front end side slit groove 440 corresponds to the "third groove" of the present invention, and the rear end side slit groove 450 corresponds to the "fourth groove" of the present invention.

As a tool 500 to be inserted into the second insertion space 430 of the collet 400, a hole for a cooling medium extending in the axial direction from the rear end side to the front end side (cutting edge side) is formed at the center side Tools may be used. When such a tool 500 is used, it is discharged from the tip side of the tool 500 through the holes for the cooling medium formed in the first insertion space 330, the second insertion space 430 and the tool 500. The cooling medium cools the tip (edge) of the tool 500.
In the present embodiment, a circumferential groove 350 extending along the circumferential direction is formed on the rear end side of the first insertion space 330 on the sleeve inner circumferential surface 310 forming the first insertion space 330. Further, the collet 400 is in communication with the collet outer peripheral surface 420 and the collet rear end surface 400b, and has a rear end side split groove 450 extending from the collet rear end surface 400b to the front end side along the axial direction. . That is, the circumferential groove 350 is in communication with the first insertion space 330 via the rear end side slit groove 450.
Further, the collet 400 is in communication with the collet outer peripheral surface 420 and the collet tip surface 400a, and has a tip side slit groove 440 extending from the collet tip surface 400a to the rear end side along the axial direction. .
For this reason, in the state where the collet 400 is inserted into the first insertion space 330, when the tip side slit groove 440 and the circumferential groove 350 are communicated, the cooling medium becomes the first insertion space 330, the rear end side. It flows out of the collect tip surface 400 a through the slot groove 450, the circumferential groove 350 and the tip side slot groove 440.
In this case, the amount of cooling medium flowing through the hole for the cooling medium provided in the tool 500 is reduced.
In the present embodiment, as described above, the length A of the longitudinal groove 340 along the axial direction from the sleeve end surface 300a is shorter than the minimum distance B between the sleeve end surface 300a and the circumferential groove 350. ([B> A]), that is, the longitudinal groove 340 and the circumferential groove 350 are configured to be separated (not in communication) in the axial direction (see FIG. 1). Thereby, the cooling medium is a gap between the sleeve front end surface 300 a and the abutment surface 421 of the collet 400 via the first insertion space 330, the rear end side split groove 450, the circumferential groove 350 and the longitudinal groove 340. Will not spill out.

In the present embodiment, the length C (see FIG. 6) along the axial direction of the tip side slit groove 440 is appropriately set. Specifically, the distance D (see FIG. 6) between the abutment surface 421 and the rear end side end of the front end side split groove 440 is the minimum distance B between the sleeve front end surface 300a and the circumferential groove 350. It is set to be shorter than (see FIG. 1) (to satisfy [B> D]). Preferably, in a state where collet 400 is inserted into first insertion space 330, the distance between sleeve front end surface 300a and the rear end side end of front end side slit groove 440 is the same as sleeve front end surface 300a. It is set to be shorter than the minimum distance B with the circumferential groove 350. That is, in a state where the collet 400 is inserted into the first insertion space 330, the circumferential groove 350 formed on the tip side slit groove 440 of the collet 400 and the sleeve inner circumferential surface 310 of the sleeve 300 does not communicate. It is done.
Thus, the cooling medium that has flowed into the circumferential groove 350 via the first insertion space 330 and the rear end side split groove 450 of the collet 400 passes the collet tip surface 400 a via the front end side split groove 440 of the collet 400. Can be prevented from flowing out, and the tip of the tool 500 can be properly cooled by the cooling medium that is discharged from the tip of the tool 500 through the hole for the cooling medium formed in the tool 500 .

In addition, when the rear end side slit groove 450 in communication with the first insertion space 330 is in communication with the sleeve front end surface 300 a (the holding unit front end surface), the cooling medium becomes the first insertion space 330, rear From the sleeve front end surface 300a (the holding unit front end surface) through the end side slot groove 450, it flows out into the gap between the sleeve front end surface 300a and the contact surface 421 of the collet 400.
In this case, the amount of cooling medium flowing through the hole for the cooling medium provided in the tool 500 is reduced.
In the present embodiment, a length E (see FIG. 8) along the axial direction from the collet rear end surface 300 b of the rear end side slotted groove 450 is a state in which the collet 400 is inserted into the first insertion space 330. In the above, the front end side end portion of the rear end side slit groove 450 is set so as not to reach the sleeve front end surface 300a (the holding portion front end surface). That is, when the collet 400 is inserted into the first insertion space 330, the rear end side slit groove 450 and the sleeve front end surface 300a do not communicate with each other.
As a result, the cooling medium flows out of the sleeve front end surface 300 a into the gap between the sleeve front end surface 300 a and the abutment surface 421 of the collet 400 via the first insertion space 330 and the rear end side split groove 450. Can be prevented, and the tip of the tool 500 can be properly cooled by the cooling medium that is discharged from the tip of the tool 500 through the hole for the cooling medium formed in the tool 500.

Further, in the present embodiment, the longitudinal groove 340 is opened at the sleeve distal end surface 300a. Therefore, in the state where the collet 400 is inserted into the first insertion space 330, when the rear end side slit groove 450 and the vertical groove 340 communicate with each other, the cooling medium becomes the rear end side slit groove 450, There is a possibility that the air may flow out of the sleeve front end surface 300 a into the gap between the sleeve front end surface 300 a and the abutment surface 421 of the collet 400 via the longitudinal groove 340.
In the present embodiment, in the state where the collet 400 is inserted into the first insertion space 330, the rear end side slit groove 450 and the longitudinal groove 340 do not communicate with each other. For example, when the collet 400 is inserted into the first insertion space 330, the length E (see FIG. 8) along the axial direction of the rear end side grooving groove 450 of the rear end side grooving groove 450 is It is set so that the front end side end does not reach the position of the rear end side end of the longitudinal groove 340. Alternatively, the collet 400 is inserted into the first insertion space 330 such that the position along the circumferential direction of the rear end side split groove 450 and the position along the circumferential direction of the longitudinal groove 340 do not overlap. Preferably, a guide member is provided to guide the insertion of the collet 400 into the first insertion space 330.
Thus, the cooling medium can be prevented from flowing out of the sleeve front end surface 300 a via the rear end side slit groove 450 and the vertical groove 340.

On the other hand, as the tool 500 inserted into the second insertion space 430 of the collet 400, a tool in which a hole for a cooling medium is not formed may be used. In this case, it is necessary to cool the tip (edge) of the tool 500 by flowing a cooling medium along the outer peripheral surface of the tool 500.
Here, in the collet 400 shown in FIG. 5, the rear end side slit groove 450 is opened to the collet rear end surface 400 b and extends to the front end side along the axial direction. Therefore, the configuration can be simplified if the rear end side slotted groove 450 can be used as a passage through which the cooling medium for cooling the front end portion of the tool 500 flows. As a method of cooling the front end portion of the tool 500 using the rear end side grooving groove 450, a method of providing a communication passage for connecting the rear end groin groove 450 and the collet front end surface 400a can be considered.

FIG. 9 shows a collet 600 according to another embodiment provided with a communication passage for communicating the rear end side slit with the collet tip surface.
In the collet 600 shown in FIG. 9, a communication groove 660 (fifth groove connecting the rear end side slit groove 650 and the collet tip surface 600a to the collet inner circumferential surface 610 forming the second insertion space 630) ) Is formed.
Further, FIG. 10 shows a collet 700 according to another different embodiment provided with a communication passage for communicating the rear end side slit groove and the collet tip surface.
In the collet 700 shown in FIG. 10, a communication hole 770 is formed in the collet 700, which communicates the rear end side slit groove 750 and the collet tip end surface 700a.
In this manner, the rear end side slotted groove 650 or 750 for facilitating the diameter reduction of the collet inner circumferential surface can be used as a cooling medium for letting the cooling medium flow out along the outer periphery of the tool 500 from the collet tip surface 600a or 700a By using it as a passage, the configuration can be simplified.

The present invention is not limited to the configuration described in the embodiment, and various modifications, additions, and deletions are possible.
In the embodiment, the holding portion is constituted by the main body portion and the sleeve, but the structure of the holding portion is not limited to this.
Although two pressing regions are provided along the axial direction, three or more pressing regions may be provided. In the case where the longitudinal groove (first groove) is formed at a portion corresponding to a plurality of pressure regions, an aspect in which the longitudinal groove is formed so as to straddle a portion corresponding to each pressure region, or each pressure The aspect which forms a longitudinal groove in each location corresponding to an area | region can be used.
The arrangement position of the pressure area can be set as appropriate.
Although the vertical groove (first groove) and the circumferential groove (second groove) do not communicate (are separated), the vertical groove (first groove) and the circumferential groove (second groove) communicate Can also be configured to
In the embodiment, as the flutes (first flutes), the flutes extending continuously along the axial direction are used, but using a plurality of flutes extending apart along the axial direction You can also. Further, although the circumferential groove (second groove) extending continuously along the circumferential direction is used, a plurality of circumferential grooves extending separately along the circumferential direction can also be used.
The vertical groove (first groove) opened in the sleeve front end surface (retention part front end surface) was used, but the longitudinal groove (first groove) not opened in the sleeve front end surface (retention part front end surface) was used. It can also be used. In this case, it is not necessary to take measures to prevent the coolant from flowing out of the sleeve end face (body end face) via the longitudinal groove (first groove).
The shape, number, arrangement position and the like of the longitudinal grooves (first grooves) and the circumferential grooves (second grooves) can be set as appropriate.
In the embodiment, the pressure of the pressurizing medium injected into the pressurizing space generates the pressurizing force which elastically deforms the inner peripheral surface of the sleeve (the inner peripheral surface of the holding portion) to the rotation center side. However, the pressurizing force is generated The method is not limited to this.
In the embodiment, the front end side split groove (third groove) and the rear end side split groove (fourth groove) are formed so as to open to the inner peripheral surface of the collet and the outer peripheral surface of the collet, It suffices to be open at the outer peripheral surface of the collet.
In the embodiment, the case of holding a tool has been described, but the holder for a machine tool of the present invention can also be used when holding a workpiece.
Each structure demonstrated by embodiment can also be used independently and can also be used combining plurality selected suitably.

DESCRIPTION OF SYMBOLS 100 Tool holder 200 Main-body part 200a Main-body part front end surface 210 Main-body part internal peripheral surface 230 Sleeve insertion space 240 1st pressurization space (1st pressurization area | region)
250 Second pressurized space (second pressurized area)
300 sleeve 300 a sleeve front end surface 300 b sleeve rear end surface 310 sleeve inner peripheral surface 320 sleeve outer peripheral surface 321 first grip portion outer peripheral surface 322 second grip portion outer peripheral surface 330 first insertion space 341 first grip portion 342 second Grip 340 vertical groove (first groove)
350 circumferential groove (second groove)
400, 600, 700 collet 400a, 600a, 700a collet tip surface 400b collet rear end surface 410, 610, 710 collet inner circumferential surface 420, 620, 720 collet outer circumferential surface 421, 621, 721 abutment surface 430, 630, 730 second portion Insertion space 440, 640, 740 tip side slotted groove (third groove)
450, 650. 750 Rear end side slotted groove (fourth groove)
500 tool 510 tool shank 660 communicating groove (fifth groove)
770 Communication hole

Claims (5)

A holding portion having a holding portion inner circumferential surface forming a first insertion space inside and a pressing region receiving a pressing force for reducing the diameter of the holding portion inner circumferential surface, the diameter of the holding portion inner circumferential surface being reduced A holder for a machine tool configured to be capable of gripping a gripped member inserted into an insertion space of
At least two pressure regions are provided along the axial direction.
A first groove extending along the axial direction and a second groove extending along the circumferential direction are formed on the inner peripheral surface of the holding portion, and the first groove is formed by the two grooves. The second groove is formed at a position corresponding to one of the pressure regions, and the second groove is formed at a position corresponding to the other pressure region of the two pressure regions. Machine tool holder characterized by A holder for a machine tool according to claim 1, wherein
The first groove is formed at a position corresponding to the pressure region disposed on the tip side in the axial direction, of the two pressure regions, and the second groove is formed by the two grooves. A holder for a machine tool characterized in that the pressure area is formed at a position corresponding to a pressure area arranged on the rear end side along the axial direction. A holder for a machine tool according to claim 2, wherein
A collet inserted into the first insertion space;
The collet has a collet inner circumferential surface and a collet outer circumferential surface that form a second insertion space inside, and the gripped member inserted into the second insertion space by the diameter reduction of the collet inner circumferential surface It is configured to be grippable,
In addition, the collet is opened in the outer peripheral surface of the collet, and a third groove extending in the axial direction from a tip end surface of the distal end along the axial direction, and the outer peripheral surface of the collet And a fourth groove extending along the axial direction from the rear end collet rear end surface along the axial direction,
A holder for a machine tool, wherein the third groove is not communicated with the second groove when the collet is inserted into the first insertion space. A holder for a machine tool according to claim 3, wherein
When the collet is inserted into the first insertion space, the fourth groove is configured not to reach the position of the end face of the holding portion on the tip end side along the axial direction of the holding portion. Machine tool holder characterized in that A holder for a machine tool according to claim 4, wherein
The holder for a machine tool, wherein the collet has a communication passage communicating the fourth groove with the collet tip surface.

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