JP2006142428A - Holder for cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a holder for a cutting tool capable of precisely holding the cutting tool at a proper position, increasing tightening force of the cutting tool and forming itself small and compact. <P>SOLUTION: A collet 4 is inserted into the inside of a first inner peripheral surface 2c of a holder main body 2, and a holding part 3a of the cutting tool 3 is made to enter the inside of an axial direction hole 5b of a collet control member 5 by passing it through a tool through hole of the holder main body 2 and a through hole of the collet 4. The collet control member 5 is inserted into the inside of the first inner peripheral surface 2c of the holder main body 2, and a male screw 5d of the collet control member 5 is screwed into a female screw 2g of the holder main body 2. Consequently, the collet 4 is firmly pressurized, and the collet b4 firmly holds the holding part 3a by large tightening force. An upper end of the holder 1 for the cutting tool firmly holding the cutting tool 3 is mounted on a machine tool. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technical field of a holder for a cutting tool such as a drill or an end mill used in a machine tool such as a machining center or an NC milling machine.

  Conventionally, when a cutting tool such as a drill or an end mill is attached to a spindle of a machine tool such as a machining center or an NC milling machine, the cutting tool holder is held by the cutting tool holder, and then the cutting tool holder is used as the spindle of the machine tool. It is attached.

  As an example of a conventional holding method for holding a cutting tool such as a drill or an end mill in the cutting tool holder, a shrink-fit holding method is known in which the cutting tool is held in the cutting tool holder by shrink fitting (for example, Patent Document 1).

  The shrink-fit holding method disclosed in Patent Document 1 is a holding method that utilizes the difference between the thermal expansion coefficient of a cutting tool and the thermal expansion coefficient of a cutting tool holder. That is, in this shrink-fit holding method, when holding the cutting tool on the cutting tool holder, the cutting tool holder having a thermal expansion coefficient larger than that of the cutting tool is heated to expand and expand the diameter. Then, after inserting the fitting shaft of the cutting tool into the fitting hole, the cutting tool is integrally held in the cutting tool holder by the contraction force of the cutting tool holder by cooling and reducing the diameter. When removing the cutting tool from the cutting tool holder, the cutting tool holder is heated to expand and expand its diameter to loosen the connection between the cutting tool and the cutting tool holder, and then the cutting tool is cut. Remove from the tool holder.

  Further, as another example of the conventional holding method for holding the cutting tool in the cutting tool holder, the inner peripheral surface of the through hole of the cutting tool holder is a tapered surface, and the cutting tool fitted into the through hole There is known a taper type holding method in which the fitting surfaces are tapered surfaces having the same slope, and the cutting tool holder is used to hold the cutting tool using these tapered surfaces (see, for example, Patent Document 2).

  The taper type holding method disclosed in Patent Document 2 is a holding method that uses the wedge effect of the tapered surface of the cutting tool holder and the tapered surface of the cutting tool. That is, in this taper type holding method, when the cutting tool is held by the cutting tool holder, the cutting tool is fitted into the through hole of the cutting tool holder from one side and the through hole of the cutting tool holder is inserted. After fitting the pull stud bolt from the other side into the cutting tool and pulling the cutting tool with the pull stud bolt, the taper surface of the cutting tool is crimped to the taper surface of the cutting tool holder. The cutting tool is integrally held in the cutting tool holder by the tightening force generated by the wedge effect. When the cutting tool is removed from the cutting tool holder, the cutting tool is pushed with a pull stud bolt so that the taper surface of the cutting tool is separated from the taper surface of the cutting tool holder and the cutting tool and the cutting tool holder are coupled. After loosening, the cutting tool is removed from the cutting tool holder by removing the pull stud bolt from the cutting tool.

  Furthermore, as another example of the conventional holding method for holding the cutting tool in the cutting tool holder, there is known a collet type holding method in which the cutting tool holder is held by a collet having a split groove extending in the axial direction. (For example, see Patent Document 2).

The collet-type holding method disclosed in Patent Document 2 is a holding method that uses elastic deformation of a collet having a split groove. That is, in this collet-type holding method, when the cutting tool is held by the cutting tool holder, the cylindrical collet having a split groove and made elastically deformable is in an expanded state, and the whole is cut. After inserting the cutting tool into this collet from the one side into the through hole of the holder for cutting, and fitting the pull stud bolt from the other side into the through hole of the cutting tool holder and screwing it into the collet By pulling the collet with a pull stud bolt and tightening the collet from the outer peripheral side of the collet's elastic deformation part by the wedge effect of the taper surface of the through hole of the cutting tool holder, the cutting tool can be operated with this tightening force. Is integrally held by a cutting tool holder. Further, by pressing the collet with a pull stud bolt to separate the elastic deformation portion of the collet from the taper surface of the cutting tool holder and removing the tightening force to expand the diameter of the elastic deformation portion of the collet, the cutting tool and the collet After loosening the connection, the cutting tool is removed from the cutting tool holder.
Japanese Patent Laid-Open No. 2003-62731. JP-A-6-55313.

  However, in the shrink-fit holding method disclosed in Patent Document 1 described above, when the cutting tool holder is held by the cutting tool holder, the cutting tool holder is cooled while the cutting tool is inserted into the cutting tool holder. Until the diameter is reduced, it is necessary to hold the cutting tool with a holding tool and hold it in a predetermined position. For this reason, the holding work of the cutting tool to the cutting tool holder is troublesome, the cutting tool is damaged by the gripping tool, and the holding position and the holding force of the cutting tool vary. For this reason, there exists a possibility that a cutting tool may not be stably and reliably hold | maintained in the appropriate position of the holder for cutting tools. In addition, since the cutting tool holder must be heated and cooled, a heating and cooling means is required, and there is a problem that the equipment is expensive.

  Moreover, in the taper type holding method disclosed in Patent Document 2 described above, since the cutting tool is simply pulled with a pull stud bolt, a certain amount of tightening force due to the wedge effect of the tapered surface can be obtained, but a large tightening force is obtained. As described above, the cutting tool may not be stably and reliably held at an appropriate position of the cutting tool holder. Furthermore, when holding the cutting tool on the cutting tool holder, it is necessary to engage the pull stud bolt with the cutting tool. When removing the cutting tool from the cutting tool holder, the pull stud bolt is cut. Since it is necessary to release the engagement from the tool, there is a problem that the work of holding the cutting tool on the cutting tool holder is troublesome. Further, until the cutting tool holder is attached to the main spindle of the machine tool, the cutting tool is not stably held by the cutting tool holder. Therefore, the cutting tool holder must be attached to the main spindle of the machine tool together with the cutting tool. In addition to the troublesome mounting work, it is difficult to accurately hold the cutting tool at the proper position of the cutting tool holder.

  Furthermore, in the collet-type holding method disclosed in Patent Document 2 described above, the collet is pulled with a pull stud bolt and the collet is reduced in diameter by the wedge effect of the tapered surface, thereby holding the cutting tool with the collet tightening force. Although a larger tightening force can be obtained than the above-mentioned taper type holding method, it is difficult to easily screw the pull stud bolt into the screw hole of the collet inserted in the cutting tool holder, and the work is troublesome. There is.

  On the other hand, the conventional collet is connected to the cutting tool holder in series in the axial direction, and after inserting the cutting tool into the collet, the cutting tool is held in the cutting tool holder by tightening the outer peripheral surface of the collet with a tightening ring. In place of the collet diameter expansion / contraction method by the wedge effect of the tapered surface in the collet-type holding method disclosed in Patent Document 2 described above, by using the collet diameter expansion / contraction method by the tightening ring, Although the problem of the collet-type holding method disclosed in Patent Document 2 described above can be solved, another problem that the outer shape of the holder for a cutting tool in which the collet is integrally assembled becomes large when a tightening ring is used. Will occur.

The present invention has been made in view of such circumstances, and an object thereof is to make it easy to mount the machine tool on the spindle, and to make it compact and compact, which is advantageous for deep drilling. It is to provide a tool holder.
Another object of the present invention is to provide a cutting tool holder that can accurately hold the cutting tool in an appropriate position, increase the tightening force of the cutting tool, and can be formed in a compact and compact manner.

  In order to solve the above-mentioned problems, the invention of claim 1 is a holder for a cutting tool that holds a cutting tool and is attached to a machine tool, and is inserted into the cylindrical holder main body and the holder main body. A cylindrical collet for clamping and holding the cutting tool, a collet control member that is inserted into the holder body and controls the clamping tool by pressing the collet, and a pressing force is applied to the collet control member In addition, the collet control member includes a pressing and fixing unit that fixes the collet control member in a state where the collet is pressed.

Further, the invention of claim 2 is characterized in that the pressing and fixing means includes a female screw provided in the holder main body and a male screw provided in the collet control member and capable of being screwed to the female screw.
Further, the invention of claim 3 is characterized in that the collet has a pair of first and second tightening portions that are tightened and controlled by the collet control member to hold the cutting tool.

  According to the cutting tool holder of the present invention configured as described above, the tightening of the collet is controlled by the collet control member fixed to the holder body in a state where the collet is pressed by the pressing and fixing means. The cutting tool holder can be attached to the spindle of the machine tool while being firmly and stably held by the cutting tool holder. This simplifies the work of attaching the cutting tool holder to the spindle of the machine tool.

Furthermore, heating / cooling means such as the conventional shrink-fit holding method is not required, and the cost for the equipment can be reduced.
Furthermore, since the collet is accommodated in the holder body, there is no joint between the holder body and the collet, and there is no need to provide a tightening ring for tightening the collet on the outer periphery of the collet. The outer shape of the holder can be made slim, and the entire cutting tool holder can be made compact and compact. Thereby, the holder for cutting tools can be made advantageous for deep cutting.

  Particularly, according to the second aspect of the present invention, since the tightening of the collet is controlled by screwing the male screw of the collet control member into the female screw of the holder body, a large tightening force can be generated in the collet. Therefore, the cutting tool can be firmly held by the large tightening force of the collet, and the cutting tool can be stably and reliably held at an appropriate position of the cutting tool holder.

  Further, since the collet control member is directly screwed into the holder main body, this screwing operation can be easily performed, and the pressing and fixing means is constituted by the screw means, so that the structure can be simplified.

  According to the invention of claim 3, since the cutting tool is clamped and held by the pair of first and second clamping portions, the cutting tool can be held more firmly and more reliably. Thereby, even if the cutting tool is relatively long, the cutting tool can be held stably and accurately, so that deep cutting can be performed more advantageously.

The best mode for carrying out the present invention will be described below with reference to the drawings.
1A and 1B show an example of an embodiment of a cutting tool holder according to the present invention, in which FIG. 1A is a front view partially showing a cross section, FIG. 1B is a top view, and FIG. 1C is a bottom view. is there. In the following description, “up” and “down” are “up” and “down”, respectively, in the drawings used for the description.

  As shown in FIGS. 1A to 1C, a cutting tool holder 1 of this example includes a holder main body 2, a collet 4 inserted into the holder main body 2 to clamp and hold the cutting tool 3, and a holder. It comprises a collet control member 5 which is inserted while being screwed into the main body 2 and controls the clamping and holding of the cutting tool 3 of the collet 4.

FIG. 2 is a cross-sectional view showing the holder main body of the cutting tool holder of the example shown in FIG. 1 in an axial cross section.
As shown in FIG. 2, the holder main body 2 is formed in an elongated cylindrical shape, and among the outer peripheral surfaces, the first outer peripheral surface 2 a, which is about two thirds of the upper side, is a cylindrical outer peripheral surface, and the lower side About one third of the second outer peripheral surface 2b is a frustoconical outer peripheral surface whose diameter decreases as it goes downward. Further, of the inner peripheral surface of the holder body 2, the first inner peripheral surface 2c of about 4/5 on the upper side is a cylindrical inner peripheral surface, and the second inner peripheral surface of about 1/5 on the lower side is The inner peripheral surface of the truncated truncated cone becomes smaller in diameter as it goes downward. As will be described later, the second inner peripheral surface is a first collet diameter-reducing control hole for reducing the diameter by applying an external force to the third outer peripheral surface 4c of the collet 4 to elastically deform the portion of the third outer peripheral surface 4c of the collet 4. 2d.

  In that case, each inclination of the frustoconical outer peripheral surface of the 2nd outer peripheral surface 2b and the frustoconical inner peripheral surface of the 1st collet diameter-reduction control hole 2d is set to be the same. In addition, each inclination of the frustoconical outer peripheral surface of the 2nd outer peripheral surface 2b and the frustoconical inner peripheral surface of the 1st collet diameter-reduction control hole 2d can also be set so that it may mutually differ. However, if the inclination of the outer peripheral surface of the truncated cone on the second outer peripheral surface 2b is made larger than the inclination of the inner peripheral surface of the truncated cone on the first collet diameter reduction control hole 2d, the outer shape of the cutting tool holder 1 becomes larger. If the inclination of the outer peripheral surface of the frustoconical truncated cone of the second outer peripheral surface 2b is smaller than the inclination of the inner peripheral surface of the truncated conical truncated cone of the first collet diameter reducing control hole 2d, the first collet diameter reduction control is not achieved. Since the strength of the hole 2d portion decreases, each inclination between the frustoconical outer peripheral surface of the second outer peripheral surface 2b and the inner peripheral surface of the frustoconical frustum of the first collet diameter reduction control hole 2d as shown in the illustrated example. It is preferable to set them to be the same as each other.

A bottom portion 2e is provided at the lower end of the holder body 2, and a tool through hole 2f having a size through which the cutting tool 3 can be penetrated is formed in the bottom portion 2e, and the first and second outer peripheral surfaces 2a and 2b of the holder body 2. The first and second inner peripheral surfaces 2c and 2d are formed concentrically. A female screw 2g is formed concentrically with the first and second inner peripheral surfaces 2c and 2d at the upper end portion of the inner peripheral surface 2c, and the upper end opening portion of the first inner peripheral surface 2c is higher than the female screw 2g. The 3 inner peripheral surface 2c ₁ is an inner peripheral surface having an inner diameter slightly larger than the inner diameters of the first inner peripheral surface 2c and the female screw 2g.

3 shows a collet of the cutting tool holder of the example shown in FIG. 1, (a) is a front view, (b) is a top view, and (c) is a bottom view.
As shown in FIGS. 3A to 3C, the collet 4 is also formed in an elongated cylindrical shape. As shown in FIG. 3A, the outer peripheral surface of the collet 4 has a first outer peripheral surface 4a slightly above the central portion as a cylindrical outer peripheral surface having a constant diameter, and a second upper surface above the first outer peripheral surface 4a. A frusto-conical frustum outer peripheral surface whose diameter decreases as the outer peripheral surface 4b goes upward, and a diameter whose diameter decreases as the third outer peripheral surface 4c below the first outer peripheral surface 4a goes downward The outer peripheral surface of the truncated cone. In that case, the inclination of the frusto-conical outer peripheral surface of the second outer peripheral surface 4b is set larger than the inclination of the outer peripheral surface of the frusto-conical truncated cone of the third outer peripheral surface 4c.

Four elongated grooves 4d, 4e, 4f, 4g extending in the axial direction from the lower end to the upper end of the collet 4 are formed at equal intervals in the circumferential direction. These split grooves 4d, 4e, 4f, and 4g are opened at the lower ends, and the upper ends extend from the lower ends of the portions of the second outer peripheral surface 4b to about two-thirds positions. In addition, in the portion of the second outer peripheral surface 4b, four elongated slits 4h, 4i, 4j, 4k extending in the circumferential direction are opened at the upper end and the lower end extends to the position of the upper end of the first outer peripheral surface 4a. They are formed at equal intervals and shifted by 45 ° in the circumferential direction with respect to the split grooves 4d, 4e, 4f, and 4g. Furthermore, in the portion of the third outer peripheral surface 4c, there are four elongated slits 4m, 4n, 4o, 4p in the circumferential direction that are open at the lower end and whose upper end extends to the position of the lower end of the first outer peripheral surface 4a. They are formed at equal intervals and shifted by 45 ° in the circumferential direction with respect to the split grooves 4d, 4e, 4f, and 4g.
Therefore, the portion of the third outer peripheral surface 4c is most easily elastically deformed, then the portion of the second outer peripheral surface 4b is most easily elastically deformed, and then the portion of the first outer peripheral surface 4a is easily elastically deformed. .

  Further, the collet 4 is provided with a through hole 4q penetrating in the axial direction. The inner diameter of the through hole 4q is applied to the first to third outer peripheral surfaces 4a, 4b, 4c of the collet 4 in the direction of reduced diameter. The cutting tool 3 is set to a size that can be freely penetrated in a free state where no is added.

  The inclination of the third outer peripheral surface 4 c is set to be substantially the same as the inclination of the second inner peripheral surface 2 d of the holder body 2. The inner diameter of the second inner peripheral surface 2d is such that the portion of the third outer peripheral surface 4c of the collet 5 can be freely inserted into the second inner peripheral surface 2d from the upper side by a predetermined amount and is inserted by a predetermined amount or more. The third outer peripheral surface 4c of the collet 5 is in close contact with the second inner peripheral surface 2d of the holder body 2, and the second inner peripheral surface 2d is brought into contact with the third outer peripheral surface 4c of the collet 5 by the wedge effect of the inclined surface. The third outer peripheral surface 4c of the collet 5 is elastically deformed by applying an external force in the diameter reducing direction so as to generate a tightening force at the third outer peripheral surface 4c of the collet 5.

4 shows a collet control member of the cutting tool holder of the example shown in FIG. 1, wherein (a) is a front view, (b) is a top view, and (c) is a bottom view.
As shown in FIGS. 4A to 4C, the collet control member 5 is formed in an elongated cylindrical shape. The outer diameter of the collet control member 5 is set to a size that allows the collet control member 5 to be slidably fitted to the first inner peripheral surface 2c of the holder body 2 with almost no gap.

  On the lower end side of the collet control member 5, a second collet diameter reduction control hole 5 a extending in the axial direction is formed concentrically with the central axis of the collet control member 5. The second collet diameter-reducing control hole 5a has a frustoconical inner peripheral surface that has a lower end opened and an inner peripheral surface that is inclined so that the diameter decreases upward from the lower end. In that case, the inclination of the inner peripheral surface of the second collet diameter reduction control hole 5 a is set to be substantially the same as the inclination of the second outer peripheral surface 4 b of the collet 5.

  In addition, the size of the inner diameter of the second collet diameter reduction control hole 5a is such that the portion of the second outer peripheral surface 4b of the collet 5 can be freely inserted by a predetermined amount, and when the predetermined amount or more is inserted, the second outer peripheral surface. 4b is in close contact with the inner peripheral surface of the second collet diameter-reducing control hole 5a, and the inner peripheral surface of the second collet diameter-reducing control hole 5a is reduced in the direction of diameter reduction to the second outer peripheral surface 4b of the collet 5 by the wedge effect of the inclined surface. The outer peripheral surface 4b of the collet 5 is elastically deformed by applying an external force, and a tightening force is generated at the second outer peripheral surface 4b of the collet 5.

  Further, an axial hole 5b having a constant inner diameter extending upward in the axial direction from the upper end of the second collet diameter reduction control hole 5a is formed concentrically with the central axis of the collet control member 5. The inner diameter is set such that the holding portion 3a of the cutting tool 3 can be freely fitted.

  On the upper end side of the collet control member 5, a rotation hole 5c that opens to the upper end and extends downward is formed concentrically with the central axis of the collet control member 5. The rotation hole 5c has a normal cross section. It is formed in a hexagonal shape. The turning hole 5c can be fitted with a turning operation tool having a regular hexagonal cross section such as a screwdriver, for example, and the turning operation tool is fitted into the turning hole 5c. Thereafter, the collet control member 5 is rotated by rotating the rotation operation tool.

  Furthermore, a male screw 5d is formed concentrically with the central axis of the collet control member 5 on the outer peripheral surface on the upper end side of the collet control member 5, and this male screw 5d can be screwed into the female screw 2g of the holder body 2. . These male screw 5d and female screw 2g constitute a pressing and fixing means.

  The axial length of the collet control member 5 is as shown in FIG. 1 (a) when the holding portion 3a of the cutting tool 3 is fastened and held by each of the second and third outer peripheral surfaces 4b and 4c of the collet 4 as will be described later. ), The collet control member 5 is set to have a size such that the upper end of the collet control member 5 is located in the holder main body 2.

The operation | movement which hold | maintains the cutting tool 3 in the holder 1 for cutting tools of this example comprised in this way is demonstrated.
First, in a state where the collet 4 shown in FIG. 3 is in a free state and the third outer peripheral surface 4c side is down, the third inner peripheral surface 2c ₁ of the holder body 2 shown in FIG. The holder body 2 is inserted into the peripheral surface 2c from the upper end opening. Then, the collet 4 stops in a state where the lower end on the third outer peripheral surface 4c side is in contact with the first collet diameter reduction control hole 2d which is the second inner peripheral surface of the holder body 2.

  Next, the holding part 3 a is inserted from the tool through hole 2 f at the lower end of the holder body 2 with the holding part 3 a of the cutting tool 3 facing upward. At this time, since the tool through-hole 2f of the holder body 2 and the through-hole 4q of the collet 4 are concentric, as shown in FIG. It penetrates through the through hole 2 f and the through hole 4 q and enters the axial hole 5 b of the collet control member 5.

In a state where the holding part 3a of the cutting tool 3 is inserted into the set amount holder main body 2, the collet control member 5 shown in FIG. The holder main body 2 shown in FIG. 2 is inserted into the third inner peripheral surface 2c ₁ , the female screw 2g and the first inner peripheral surface 2c from the upper end opening of the holder main body 2. Then, the collet control member 5 stops in a state where the male screw 5d is in contact with the female screw 2g of the holder body 2. At this time, the second collet diameter reduction control hole 5 a is fitted to the second outer peripheral surface 4 b of the collet 4.

  Next, the collet control member 5 is rotated by fitting the rotation operation tool into the rotation hole 5c of the collet control member 5, so that the male screw 5d is screwed into the female screw 2q. Thereby, the collet control member 5 moves further downward and presses the collet 4 downward, so that the collet 4 also moves downward.

  Then, the diameter of the second outer peripheral surface 4b of the collet 4 is reduced by the wedge effect due to the inclination of the second collet diameter-reducing control hole 5a and the inclination of the second outer peripheral surface 4b of the collet 4. The portion firmly holds and holds the holding portion 3a of the cutting tool 3. Further, when the collet 4 is pressed and moved downward, a portion of the third outer peripheral surface 4c of the collet 4 due to the wedge effect due to the inclination of the first collet diameter reduction control hole 2d and the inclination of the third outer peripheral surface 4c of the collet 4 Therefore, the third outer peripheral surface 4c also firmly holds the holding portion 3a of the cutting tool 3 by tightening.

  Thus, each part of the 2nd and 3rd outer peripheral surfaces 4b and 4c constitutes a pair of 1st and 2nd clamping parts of the present invention, respectively. Further, since the diameter of the first outer peripheral surface 4a of the collet 4 is also reduced, the tightening and holding of the holding portion 3a of the cutting tool 3 by each of the second and third outer peripheral surfaces 4b and 4c of the collet 4 is further strengthened. It will be a thing.

  When the male screw 5d is screwed into the female screw 2g by a predetermined amount with the turning operation tool, the turning operation tool is removed from the turning hole 5c of the collet control member 5. At this time, as shown in FIG. 1A, the upper end of the collet control member 5 is located in the holder main body 2 and does not protrude from the holder main body 2 to the outside.

  Further, since the fastening of the male screw 5d and the female screw 2g is strong, the fastening of the male screw 5d and the female screw 2g does not loosen even if the turning operation tool is removed from the turning hole 5c. Therefore, the tightening and holding of the holding portion 3a of the cutting tool 3 by the portions of the second and third outer peripheral surfaces 4b and 4c of the collet 4 is held in a strong state.

  Therefore, the upper end side of the cutting tool holder 1 is attached to the spindle of the machine tool in a state where the cutting tool 3 is firmly and stably held by the cutting tool holder 1 in this way. As a method for attaching the cutting tool holder 1 to the main spindle of the machine tool, a conventionally known attachment method can be used.

  According to the cutting tool holder 1 of this example configured as described above, since the tightening of the collet 4 is controlled by the collet control member 5 screwed into the holder main body 2, a large tightening force can be generated in the collet 4. it can. Therefore, the cutting tool can be firmly held by the large tightening force of the collet 4, and the cutting tool 3 can be stably and reliably held at an appropriate position of the cutting tool holder 1. In that case, since the cutting tool 3 is clamped and held at two locations on each of the second and third outer peripheral surfaces 4b and 4c, the cutting tool 3 can be held more firmly and more reliably.

  Further, since the male screw 5d of the collet control member 5 is directly screwed into the female screw 2g of the holder body 2, this screwing operation can be easily performed, and the pressing and fixing means is constituted by screw means. Can be configured simply.

Further, the cutting tool holder 1 is attached to the spindle of the machine tool while the cutting tool 3 is firmly and stably held on the cutting tool holder 1 by screwing the collet control member 5 into the holder body 2. Therefore, the attachment work of the cutting tool holder 1 to the spindle of the machine tool is simplified.
Furthermore, heating / cooling means such as the conventional shrink-fit holding method is not required, and the cost for the equipment can be reduced.

  Further, since the collet 4 is accommodated in the holder main body 2, there is no joint between the holder main body 2 and the collet 4, and there is no need to provide a tightening ring for tightening the collet 4, so the collet is integrated. Therefore, the outer shape of the assembled cutting tool holder can be made slim, and the entire cutting tool holder 1 can be made compact and compact.

  Accordingly, when the workpiece W has a relatively high wall W1 as shown in FIG. 5, when the workpiece W is deeply cut at a position very close to the wall W1, the cutting tool of this example shown by a solid line is used. According to the holder 1, since the outer shape is slim, this deep cutting can be performed. However, in the case of a cutting tool holder using a conventional tightening ring R indicated by a two-dot chain line, this tightening ring Since R interferes with the wall W1, it is impossible to deep-cut the workpiece W near the wall W1. In the cutting tool holder using the tightening ring R, as shown by the dotted line, it is possible to perform cutting only at a position away from the wall W1 where the tightening ring R does not interfere with the wall W1. The same applies to the deep cutting of the workpiece W when the wall W1 is around the cutting tool 3. Therefore, the cutting tool holder 1 of this example can be made advantageous for deep cutting.

  Furthermore, since the cutting tool 3 is clamped and held by the pair of first and second clamping portions, the cutting tool 3 can be held more firmly and more reliably. As a result, even if the cutting tool 3 is relatively long, the cutting tool 3 can be held stably and accurately, so that deep cutting can be performed more advantageously.

6 (a) to 6 (c) are views similar to FIGS. 3 (a) to 3 (c), showing another example of a collet of a cutting tool holder of the present invention.
In the collet 4 of the example shown in FIG. 3 described above, the four split grooves 4h, 4i, 4j, 4k formed on the second outer peripheral surface 4b and the four split grooves 4m formed on the third outer peripheral surface 4c, 4n, 4o, and 4p are provided by being divided in the four axial directions by the first outer peripheral surface 4a. As shown in FIGS. 6A to 6C, these four dividing grooves 4h, 4i, 4j, 4k and the four dividing grooves 4m, 4n, 4o, 4p communicate with each other to form four dividing grooves 4h, 4i, 4j, 4k. That is, the four split grooves 4h, 4i, 4j, and 4k extend from the second outer peripheral surface 4b to the middle of the third outer peripheral surface 4c through the first outer peripheral surface 4a.

  The other configuration of the cutting tool holder 1 of this example is the same as the configuration of the cutting tool holder 1 of the example shown in FIGS. The operational effects of the cutting tool holder 1 of this example are the same as the operational effects of the cutting tool holder 1 of the above-described example.

FIGS. 7A to 7C are views similar to FIGS. 3A to 3C, showing still another example of the collet of the cutting tool holder of the present invention.
In the collet 4 of the example shown in FIG. 3, the four split grooves 4d, 4e, 4f, and 4g formed on the second outer peripheral surface 4b pass through the first outer peripheral surface 4a from the third outer peripheral surface 4c, respectively. Although extended to the middle of the second outer peripheral surface 4b, as shown in FIGS. 7A to 7C, these four split grooves 4d, 4e, 4f, 4g are respectively formed on the first outer peripheral surface 4a. Is divided by. That is, the four split grooves 4d, 4e, 4f, and 4g are formed on the four split grooves 4d ₁ , 4e ₁ , 4f ₁ , 4g ₁ formed on the second outer peripheral surface 4b and the third outer peripheral surface 4c, respectively. The four split grooves 4d ₂ , 4e ₂ , 4f ₂ , 4g ₂ are formed.

  The other configuration of the cutting tool holder 1 of this example is the same as the configuration of the cutting tool holder 1 of the example shown in FIGS. Further, the operational effects of the cutting tool holder 1 of this example are the same as the operational effects of the cutting tool holder 1 of the example shown in FIGS.

FIGS. 8A to 8C are views similar to FIGS. 3A to 3C, showing still another example of the collet of the cutting tool holder of the present invention.
In the collet 4 of the example shown in FIG. 6 described above, the first outer peripheral surface 4a having a constant diameter is provided between the second outer peripheral surface 4b and the third outer peripheral surface 4c. As shown in c), in the collet 4 of this example, the first outer peripheral surface 4a is omitted, and the second outer peripheral surface 4b and the third outer peripheral surface 4c are directly connected. In this case, the connecting portion between the second outer peripheral surface 4b and the third outer peripheral surface 4c is a curved R portion.

  The other configuration of the collet 4 of this example is the same as the configuration of the collet of the example shown in FIG. 6, and the other configuration of the cutting tool holder 1 of this example is the example shown in FIGS. The configuration of the cutting tool holder 1 is the same. Further, the operational effects of the cutting tool holder 1 of this example are the same as the operational effects of the cutting tool holder 1 of the example shown in FIGS.

FIGS. 9A to 9C are views similar to FIGS. 3A to 3C, showing still another example of the collet of the cutting tool holder of the present invention.
In the collet 4 of the example shown in FIG. 7 described above, the first outer peripheral surface 4a having a constant diameter is provided between the second outer peripheral surface 4b and the third outer peripheral surface 4c. As shown in c), in the collet 4 of this example, the first outer peripheral surface 4a is omitted, and the second outer peripheral surface 4b and the third outer peripheral surface 4c are directly connected. In this case, the connecting portion between the second outer peripheral surface 4b and the third outer peripheral surface 4c is a curved R portion.

  The other configuration of the collet 4 of this example is the same as the configuration of the collet of the example shown in FIG. 7, and the other configuration of the cutting tool holder 1 of this example is the example shown in the above-described FIGS. The configuration of the cutting tool holder 1 is the same. Further, the operational effects of the cutting tool holder 1 of this example are the same as the operational effects of the cutting tool holder 1 of the example shown in FIGS.

  In the above-described example, the pressing and fixing means is constituted by the screw means of the male screw 5d and the female screw 2g. However, while the pressing force is applied to the collet control member 5, the collet control member 5 presses the collet 4. Any means that can fix the collet control member 5 to the holder body 2 may be used.

Further, the number of the dividing grooves and the arrangement of the dividing grooves of the collet 4 are not limited to the number of dividing grooves and the arrangement of the dividing grooves in each of the examples described above, and can be arbitrarily set variously.
Further, in each of the above-described examples, the inclination angle of the second outer peripheral surface 2b is set larger than the inclination angle of the third outer peripheral surface 2c, but the inclination angle of the second outer peripheral surface 2b is set to the inclination angle of the third outer peripheral surface 2c. Or smaller than the inclination angle of the third outer peripheral surface 2c.

  The cutting tool holder of the present invention can be suitably used for a cutting tool holder of a cutting tool such as a drill or an end mill used in a machine tool such as a machining center or an NC milling machine.

An example of embodiment of the holder for cutting tools which concerns on this invention is shown, (a) is a front view which takes a cross section partially, (b) is a top view, (c) is a bottom view. It is sectional drawing which shows the holder main body of the holder for cutting tools of the example shown in FIG. 1 in the cross section of an axial direction. The collet of the cutting tool holder of the example shown in FIG. 1 is shown, (a) is a front view, (b) is a top view, and (c) is a bottom view. The collet control member of the holder for cutting tools of the example shown in FIG. 1 is shown, (a) is a front view, (b) is a top view, (c) is a bottom view. It is a figure explaining the deep cutting by the holder for cutting tools of the example shown in FIG. (A) thru | or (c) are the same figures as Fig.3 (a) thru | or (c) which show the other example of the collet of the holder for cutting tools of this invention. (A) thru | or (c) is a figure similar to Fig.3 (a) thru | or (c) which shows the other example of the collet of the holder for cutting tools of this invention. (A) thru | or (c) is a figure similar to Fig.3 (a) thru | or (c) which shows the other example of the collet of the holder for cutting tools of this invention. (A) thru | or (c) is a figure similar to Fig.3 (a) thru | or (c) which shows the other example of the collet of the holder for cutting tools of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cutting tool holder, 2 ... Holder main body, 2a ... 1st outer peripheral surface, 2b ... 2nd outer peripheral surface, 2c ... 1st inner peripheral surface, 2d ... 1st collet diameter reduction control hole, 2f ... Tool through-hole, 2 g ... female screw, 3 ... cutting tool, 4 ... collet, 4a ... first outer peripheral surface, 4b ... second outer periphery, 4c ... third outer peripheral surface, 4d, 4e, 4f, 4g , 4d 1, 4e 1, 4f 1 4g ₁ , 4d ₂ , 4e ₂ , 4f ₂ , 4g ₂ , 4h, 4i, 4J, 4k, 4m, 4n, 4o, 4p ... split groove, 4q ... through hole, 5 ... collet control member, 5a ... second Collet diameter reduction control hole, 5b ... Axial hole, 5c ... Rotation hole, 5d ... Male screw

Claims (3)

In a cutting tool holder that holds a cutting tool and is attached to a machine tool,
A cylindrical holder main body, a cylindrical collet that is inserted into the holder main body and holds the cutting tool tightly, and inserted into the holder main body to press the collet to tighten the cutting tool. A collet control member to be controlled, and a pressing fixing means for applying a pressing force to the collet control member and fixing the collet control member in a state where the collet control member presses the collet. Cutting tool holder. 2. The cutting tool holder according to claim 1, wherein the pressing and fixing means includes a female screw provided in the holder main body and a male screw provided in the collet control member and screwable with the female screw. 3. The cutting tool holder according to claim 1, wherein the collet has a pair of first and second tightening portions that are tightened and controlled by the collet control member to hold the cutting tool. 4. .

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