JP5780188B2 - Clamping mechanism of cutting member and blade part exchangeable cutting tool using the same - Google Patents

Description

  The present invention relates to a clamping mechanism for a cutting member and a blade part exchangeable cutting tool using the same.

Conventionally, a rotary tool (blade part exchangeable cutting tool) in which a round piece insert is detachably attached to a tip shaft part of a tool body is known. This type of rotary tool is known to be a driven type that performs cutting by rotating the circular piece insert around its central axis with respect to the tool body due to cutting resistance acting on the circular piece insert during cutting. Yes.
In recent years, a multi-tasking machine having a milling function in which a tool holding portion of a lathe can be rotated is becoming widespread. According to such a multi-tasking machine, a circular piece insert is driven with respect to a tool body. It is possible to perform the turning process of the work material while being fixed without being rotated and being driven to rotate at a desired rotation speed regardless of the direction of feed to the work material.

  As such a drive-type rotary tool, for example, in FIG. 20 of the following Patent Document 1, an annular shape in which a through hole is formed along the central axis is formed, and a circumferential cutting edge is provided at the tip edge portion of the outer peripheral surface. A cutting insert having a cylindrical shape, and a shaft portion of a tool main body having a distal end surface facing the distal end side in the central axis direction, which is in contact with a seating surface facing the proximal end side in the central axial direction of the cutting insert; A sleeve that fits into the shaft portion of the tool body, and a threaded hole that is inserted through the through hole of the cutting insert and drilled in the distal end surface of the shaft portion, thereby bringing the cutting insert into the shaft portion. The thing provided with the screw member fixed so that attachment or detachment is possible is disclosed.

  In the rotary tool disclosed in Patent Document 1, the outer peripheral surface of the cutting insert is gradually reduced in diameter toward the proximal end side, and the outer peripheral surface and the distal end portion on the inner peripheral surface of the sleeve are fitted. ing. The distal end portion of the sleeve can be elastically deformed in the radial direction. Then, the cutting insert is fixed while being aligned with the shaft portion of the tool body by tightening the screw member inserted through the through hole of the cutting insert and screwed into the screw hole of the tool body to the end.

  In addition to the rotary tool described above, a cutting head having a cylindrical shape and having a cutting edge at least at the outer periphery of the tip (tip edge of the outer peripheral surface) and the cutting head are detachably mounted and rotated about an axis. A blade-exchangeable cutting tool such as a head-exchangeable end mill having a tool body is known (see, for example, Patent Document 2 below). Such a blade part exchange-type cutting tool also has a structure in which the cutting head is aligned with the tool body.

Special table 2011-506111 gazette Japanese Patent No. 4288905

However, the above-described conventional blade replacement type cutting tool has the following problems.
That is, for example, in the rotary tool of Patent Document 1, the cutting insert (cutting member) is aligned with the shaft portion of the tool body by tightening the screw member to the end. When a molding error or a processing error occurs in the outer diameter of the sleeve (particularly when the outer diameter is larger than a predetermined outer diameter), the sleeve may be plastically deformed beyond the allowable elastic deformation of the sleeve.

  When the sleeve is plastically deformed in this way, the cutting insert may be firmly fitted to the sleeve, making it difficult to remove, or the attachment rigidity of the cutting insert to the shaft portion of the tool body may be reduced. Accordingly, it is conceivable to strictly ensure the outer diameter accuracy of the cutting insert by polishing or the like, but in this case, the manufacturing becomes complicated. Further, if the screw member is simply loosened for the purpose of preventing plastic deformation of the sleeve, the cutting insert cannot be stably fixed.

  The present invention has been made in view of such circumstances, and the cutting member is accurately and easily aligned with the shaft portion of the tool body without requiring strict accuracy in the outer diameter of the cutting member. It is an object of the present invention to provide a clamping mechanism for a cutting member that can be stably fixed and can maintain high-quality cutting over a long period of time, and a blade-part exchangeable cutting tool using the same.

In order to solve such problems and achieve the above object, the present invention proposes the following means.
That is, the clamping mechanism of the cutting member of the present invention has an annular shape or a cylindrical shape in which a through hole is formed along the central axis, and has a cutting member having a cutting edge on at least an outer peripheral surface, and a central axis direction of the cutting member. A shaft portion of the tool body that has a tip surface that is in contact with a seating surface facing the base end side and faces the tip end side in the central axis direction, and has a cylindrical shape, and is fitted to the shaft portion of the tool body on the inner peripheral surface thereof. And a nut member having a fitting portion to be engaged, a screwing portion to be screwed to the shaft portion, and a screw hole that is inserted through the through hole of the cutting member and is formed in the tip surface of the shaft portion. A screw member that detachably fixes the cutting member to the shaft portion, and a first tapered surface that gradually decreases in diameter toward the base end side on the outer peripheral surface of the cutting member. Formed on the inner circumferential surface of the nut member, gradually increasing in diameter toward the tip side Rutotomoni, wherein the second tapered surface that is fitted to the first tapered surface is formed.
Further, the present invention is a blade part exchangeable cutting tool comprising a cutting member, and a tool body having a shaft portion to which the cutting member is detachably mounted and rotated about the shaft, The cutting member clamping mechanism is used.

  In the cutting mechanism of the cutting member according to the present invention and the blade part replaceable cutting tool using the same, for example, an annular round piece insert (cutting insert) or a cutting head such as a cylindrical shell end mill is used as the cutting member. be able to. This cutting member has a cutting edge at least on the outer peripheral surface.

  As a procedure for mounting the cutting member on the shaft portion of the tool body, first, a nut member is mounted on the shaft portion of the tool body in advance. At this time, the fitting portion formed on the inner peripheral surface of the nut member is fitted to the shaft portion of the tool body, whereby the nut member and the shaft portion are positioned (centered) coaxially (concentrically). Further, when the threaded portion formed on the inner peripheral surface of the nut member is threadedly engaged with the shaft portion of the tool body, the nut member is rotated in a direction (circumferential direction) around the central axis. The nut member can be moved in the direction of the central axis while the nut member is aligned with respect to the shaft portion of the tool body.

  Next, in a state where the tip surface of the shaft portion of the tool body is exposed to the tip side from the nut member, the cutting member is placed on the tip surface to contact the seating surface, and the screw member is inserted into the through hole of the cutting member. And is screwed into the screw hole of the shaft portion. At this time, the screw member is not tightened strongly, but is temporarily fixed so that the cutting member can receive an external force and move in the radial direction perpendicular to the central axis.

  Next, when the nut member is rotated with respect to the shaft portion of the tool main body and is moved toward the distal end side in the central axis direction, the second taper surface of the nut member becomes the first taper surface of the cutting member. By abutting and further tightening the nut member, the tapered surfaces are fitted to each other while being in sliding contact with each other. With this fitting, the cutting member is aligned with the nut member.

Specifically, since the cutting member is centered with respect to the outer peripheral surface of the nut member, the center of the cutting edge formed on the outer peripheral surface (the cutting edge is a front view as viewed from the central axis direction). It has a circumferential shape and its center) is aligned with the nut member and the shaft portion of the tool body.
In this way, the cutting member, the nut member, and the shaft portion of the tool body are all aligned with each other, and the screw member is further tightened from this state, whereby the cutting member is fixed to the shaft portion of the tool body.

  According to the present invention, as described above, since the center of the cutting edge of the cutting member is coaxially aligned with the shaft portion of the tool body, the roundness and cylindricity in the rotation trajectory around the center axis of the cutting edge can be reduced. By sufficiently cutting and cutting with the cutting member while rotating the tool body around the central axis, the processing accuracy is stably secured to a high quality.

  Further, when the nut member is rotated with respect to the shaft portion of the tool body and the second tapered surface and the first tapered surface are fitted, the amount of rotation of the nut member can be adjusted as appropriate. That is, unlike the present invention, for example, as shown in FIG. 20 of Japanese Translation of PCT International Publication No. 2011-506111, the cutting member cannot be centered and fixed to the shaft portion of the tool body unless the screw member is tightened to the end. In the case of this configuration, there is a possibility that the member (sleeve 2025) corresponding to the nut member shown in the drawing is plastically deformed by this tightening. On the other hand, according to the present invention, when the cutting member can be aligned with the shaft portion of the tool main body, it is not necessary to screw the nut member any further, and therefore plastic deformation of the nut member can be prevented. Therefore, highly accurate cutting can be stably maintained over a long period of time.

  Further, since the cutting member is centered with respect to the nut member on the basis of the outer peripheral surface thereof, the dimensional accuracy at the time of manufacturing the cutting member can be set relatively slowly. Specifically, when a sintered body made of, for example, a cemented carbide is used as the cutting member, a slight molding error or processing error (an actual outer diameter with respect to a predetermined outer diameter) is added to the outer diameter of the cutting member. (Slightly larger or smaller diameter) is likely to occur, but even in such a case, highly accurate centering is possible, and even if the center of the through hole of the cutting member is slightly shifted from the central axis, High-precision alignment is possible without being affected by this.

Further, it is possible to use the cutting member without strict processing accuracy required for polishing the first tapered surface on the outer peripheral surface of the cutting member, or to leave the sintered surface without polishing the first tapered surface. It is. Therefore, manufacture of a cutting member is easy.
In particular, even when a slight molding error or machining error occurs in the outer diameter of the cutting member, it can be easily handled by adjusting the amount of rotation of the nut member as described above, and can be easily centered. It is.

  Thus, according to the present invention, a simple structure is used to cut the outer diameter of the cutting member with respect to the shaft portion of the tool body without requiring strict accuracy, and thus without complicated manufacturing. The members can be easily and accurately aligned, can be fixed stably, and high-quality cutting can be maintained over a long period of time.

  Further, in the clamping mechanism of the cutting member of the present invention, an annular or cylindrical loosening prevention member that is screwed into the shaft portion of the tool main body and can come into contact with the nut member from the base end side may be provided. Good.

  In this case, as described above, after the nut member is fitted to the cutting member, the locking member is rotated around the central axis relative to the shaft portion of the tool body and moved to the distal end side, and the proximal end side is moved. By making the nut member come into contact with the nut member, the action of a double nut can be obtained, and the nut member can be easily and reliably prevented from loosening.

  In the cutting member clamping mechanism of the present invention, a rotation restricting portion that restricts relative rotation around the central axis between the cutting member and the shaft portion of the tool body may be provided.

In this case, for example, by forming recesses and protrusions that engage with each other on the seating surface of the cutting member and the tip surface of the shaft portion of the tool body, the rotation restricting portion is formed, thereby cutting the shaft portion of the tool body. It is possible to prevent the cutting member from unintentionally rotating around the central axis with respect to the shaft portion of the tool body when the member is mounted or during cutting.
Therefore, the workability when the cutting member is attached to and detached from the shaft portion of the tool body is improved, and the cutting can be performed with high accuracy and stability.

  According to the cutting member clamping mechanism of the present invention and the blade-exchangeable cutting tool using the same, the cutting member can be accurately attached to the shaft portion of the tool body without requiring strict accuracy in the outer diameter of the cutting member. It can be aligned easily and easily, and can be fixed stably, and high-quality cutting can be maintained over a long period of time.

It is a perspective view which shows the blade part exchange type cutting tool using the clamp mechanism of the cutting member which concerns on one Embodiment of this invention. It is a disassembled perspective view of the blade part exchange-type cutting tool of FIG. FIG. 2 is a side cross-sectional view (longitudinal cross-sectional view) of the blade part replaceable cutting tool of FIG. 1. It is a figure which expands and shows the principal part of the blade part exchange-type cutting tool of FIG. It is the (a) perspective view and (b) side view of the tool main body used for the blade part exchange-type cutting tool of FIG. It is the (a) perspective view of the nut member used for the blade part exchange-type cutting tool of Drawing 1, and (b) side sectional view. It is the (a) perspective view and (b) side sectional view of the locking member used for the blade part exchange-type cutting tool of FIG. FIG. 2 is a diagram for explaining a procedure for mounting a cutting member on a shaft portion of a tool main body in the blade part replaceable cutting tool of FIG. 1.

DESCRIPTION OF EMBODIMENTS Hereinafter, a cutting member clamping mechanism 1 according to an embodiment of the present invention and a blade exchange type cutting tool 10 using the same will be described with reference to the drawings.
As shown in FIG. 1, the blade part replaceable cutting tool 10 includes a cutting member 2 that is a circular cutting insert, and a shaft-shaped tool body 3 to which the cutting member 2 is detachably mounted. By rotating the base end portion in the axial direction of 3 (lower end portion in FIG. 1) around the axis in a state of being rotatably attached to a tool holding portion of a lathe which is a combined processing machine (not shown), This is a blade part exchange-type turning tool that cuts (turns) a workpiece with the cutting edge 4 of the cutting member 2. Specifically, the blade part replaceable cutting tool 10 of the present embodiment is a drive type rotary tool.
The blade part replaceable cutting tool 10 of the present embodiment has a unique configuration that is not present in the structure of the part where the cutting member 2 is attached to the tool body 3 (the cutting member clamping mechanism 1).

  As shown in FIGS. 2 to 4, the cutting member clamping mechanism 1 of the present embodiment has an annular shape in which a through hole 5 is formed along the central axis O, and has a cutting edge 4 on at least an outer peripheral surface 6. The cutting member 2 and the shaft portion 11 of the tool body 3 having a distal end surface 12 which is in contact with the seating surface 8 facing the proximal end side in the central axis O direction of the cutting member 2 and faces the distal end side in the central axis O direction; A nut member 20 having a cylindrical shape and having a fitting portion 22 fitted to the shaft portion 11 of the tool body 3 on the inner peripheral surface 21 thereof, and a screwing portion 23 screwed to the shaft portion 11, and a cutting member A screw member 30 that is inserted into the through-hole 5 of the shaft 2 and screwed into a screw hole 13 formed in the tip surface 12 of the shaft portion 11 so as to detachably fix the cutting member 2 to the shaft portion 11; An annular locking portion that is screwed into the shaft portion 11 of the tool body 3 and can contact the nut member 20 from the base end side. And a 40.

Here, the central axis O of the cutting member 2 and the axis of the tool body 3 are coaxial with each other, and in this specification, the cutting body 2 side of the tool body 3 along this central axis (axis) O direction. The upper side in FIG. 2 is referred to as the distal end side, and the side opposite to the cutting member 2 of the tool body 3 (that is, the tool body 3 side in the cutting member 2 and the lower side in FIG. 2) is referred to as the proximal end side. A direction perpendicular to the central axis O (a direction perpendicular to the central axis O) is referred to as a radial direction, and a direction around the central axis O is referred to as a circumferential direction.
In the present embodiment, the cutting member 2, the tool body 3, the nut member 20, the screw member 30, and the locking member 40 are arranged coaxially with the central axis O as a common axis.

The cutting member 2 is made of a sintered body made of a hard material such as a cemented carbide.
In FIG. 2 to FIG. 4, an annular (circular) surface facing the distal end among the both surfaces facing the central axis O direction of the cutting member 2 is a rake surface 7. Of the two surfaces facing the central axis O direction of the cutting member 2, an annular surface facing the base end is the seating surface 8. The rake surface 7 and the seating surface 8 are flat surfaces perpendicular to the central axis O.

  A through hole 5 is opened at the center of the rake face 7 and the seating face 8. The inner diameter of the through hole 5 is substantially constant over the entire length in the direction of the central axis O, and chamfering is applied to the opening portions of the rake face 7 and the seating face 8 respectively.

The cutting edge 4 is formed in a circular shape by forming a crossing ridge line between the rake face 7 and the outer peripheral face 6, and is disposed at the front end edge of the outer peripheral face 6. The tip edge of the cutting member 2 on which the cutting edge 4 is formed has the largest outer diameter in the blade part replaceable cutting tool 10.
In the illustrated example, an annular groove extending in the circumferential direction is formed on the outer peripheral edge of the rake face 7, and this annular groove serves as a chip breaker 7a.

  The outer peripheral surface 6 facing the radial direction in the cutting member 2 is formed in a multi-stage shape in which the proximal end portion is reduced in diameter by one step from the distal end portion, and the distal end portion is a flank 6a. The side portion is the first tapered surface 6b.

  The flank 6a is formed in a tapered shape that gradually decreases in diameter as it goes from the cutting edge 4 toward the base end, and the first tapered surface 6b is also formed in a diameter that gradually decreases as it goes toward the base end. The flank 6a and the first taper surface 6b are each subjected to polishing, but may be sintered skin that is not subjected to such polishing.

In the example shown in FIGS. 3 and 4, the amount of displacement in the radial direction per unit length along the direction of the central axis O in the flank 6a is larger than the amount of displacement in the first tapered surface 6b. Yes. That is, in the side sectional view shown in FIGS. 3 and 4, the inclination angle of the flank 6a with respect to the central axis O is larger than the inclination angle of the first taper surface 6b.
An annular end surface 6c is formed between the flank 6a and the first taper surface 6b on the outer peripheral surface 6 of the cutting member 2 and faces the base end side in the central axis O direction.

The tool main body 3 is formed of a steel material, and the shaft portion 11 at the tip thereof is formed to have a one-step smaller diameter than the shank portion 14 other than the shaft portion 11.
3 and 4, the distal end surface 12 of the shaft portion 11 is a flat surface perpendicular to the central axis O, and the outer diameter of the distal end surface 12 is the cutting member 2 that comes into contact with the distal end surface 12. The outer diameter of the seating surface 8 is smaller. Further, the inner peripheral surface of the screw hole 13 drilled from the distal end surface 12 to the proximal end side of the shaft portion 11 is subjected to female thread processing.

  On the outer peripheral surface of the shaft portion 11 of the tool body 3, a screwed portion 15 to be screwed into the screwed portion 23 of the nut member 20, and a screwed portion positioned on the tip side of the screwed portion 15. The fitting portion 16 is formed so as to have a smaller diameter than 15 and to be fitted to the fitting portion 22 of the nut member 20.

  5 (a) and 5 (b), the threaded portion 15 of the outer peripheral surface of the shaft portion 11 is a male screw portion subjected to male screw processing. Further, the fitted portion 16 of the outer peripheral surface of the shaft portion 11 is formed in a cylindrical (column) outer peripheral surface shape parallel to the central axis O. In the illustrated example, between the screwed portion 15 and the fitted portion 16 on the outer peripheral surface of the shaft portion 11, the diameter is one step smaller than those of the screwed portion 15 and the fitted portion 16. A stepped portion 17 is formed.

The nut member 20 is formed of a steel material.
3, 4, and 6 (a) and 6 (b), the distal end portion of the outer peripheral surface of the nut member 20 is formed with a gradually reduced diameter toward the distal end side. Further, the portion of the outer peripheral surface of the nut member 20 other than the tip portion is formed in a cylindrical outer peripheral surface parallel to the central axis O.
In the present embodiment, the outer peripheral surface of the nut member 20 has a circular cross section perpendicular to the central axis O, and the outer appearance of the nut member 20 is cylindrical, but is not limited thereto. For example, the cross section of the outer peripheral surface may be a polygonal shape such as a hexagon, and the outer appearance of the nut member 20 may be a polygonal cylindrical shape.

Further, in the inner peripheral surface 21 of the nut member 20, the tip portion has a one-step inner diameter larger than the portion other than the tip portion, and the tip portion gradually increases in diameter toward the tip side. The surface 24 is used. The second taper surface 24 is formed so as to be fitted to the first taper surface 6b, and has a unit length along the central axis O direction of the second taper surface 24 in a side sectional view shown in FIGS. The amount of displacement in the radial direction is set corresponding to the amount of displacement in the first tapered surface 6b of the cutting member 2 described above.
In addition, since the distal end portions of the outer peripheral surface and the inner peripheral surface 21 of the nut member 20 are formed as described above, the thickness of the distal end portion of the nut member 20 gradually decreases toward the distal end side. It has become.

  Further, on the inner peripheral surface 21 of the nut member 20, a fitting portion 22 and a screwing portion 23 are arranged in this order on the proximal end side of the second tapered surface 24. Of the inner peripheral surface 21 of the nut member 20, the fitting portion 22 is formed in a cylindrical inner peripheral surface parallel to the central axis O and can be fitted to the fitted portion 16 of the shaft portion 11. . Further, the screwing portion 23 of the inner peripheral surface 21 of the nut member 20 is a female screw portion subjected to female screw processing, and can be screwed into the screwed portion 15 of the shaft portion 11. .

Further, an annular end surface 25 facing the front end side in the direction of the central axis O is formed between the second tapered surface 24 and the fitting portion 22 on the inner peripheral surface 21 of the nut member 20.
Further, the base end surface 27 of the nut member 20 has an annular shape and is a flat surface perpendicular to the central axis O.

  As shown in FIGS. 3 and 4, the second tapered surface 24 of the nut member 20 is in sliding contact with the first tapered surface 6 b of the cutting member 2 toward the tip side, and these are fitted. Thus, between the tip opening edge (tip surface 26) of the nut member 20 and the end surface 6c of the outer peripheral surface 6 of the cutting member 2, and between the end surface 25 of the nut member 20 and the seating surface 8 of the cutting member 2. Each is provided with a gap.

The locking member 40 is made of steel.
3, 4, and 7 (a) and 7 (b), the inner peripheral surface of the locking member 40 is subjected to female thread processing that can be screwed into the threaded portion 15 of the shaft portion 11. A screw part 41 is formed. In addition, the front end surface 42 of the locking member 40 has an annular shape and is a flat surface perpendicular to the central axis O.
In this embodiment, the outer peripheral surface of the locking member 40 has a circular cross section perpendicular to the central axis O, and the locking member 40 has an annular appearance. For example, the cross section of the outer peripheral surface may be a polygonal shape such as a hexagon, and the appearance of the locking member 40 may be a polygonal ring.

  2 to 4, the screw member 30 includes a screw portion 31 that has been subjected to male screw processing, and a head portion 32 that is larger in diameter than the screw portion 31. The screw member 30 is inserted into the through hole 5 of the cutting member 2 from the distal end to the proximal end side with the end portion of the screw portion 31 opposite to the head portion 32 facing the proximal end side. The screw part 31 inserted into the through hole 5 is screwed into the screw hole 13 of the shaft part 11 of the tool body 3.

Further, the outer diameter of the screw portion 31 in the screw member 30 is slightly smaller than the inner diameter of the through hole 5 of the cutting member 2, whereby the cutting member is inserted in the state where the screw portion 31 is inserted into the through hole 5. 2 is movable in the radial direction.
Also, what is indicated by reference numeral 33 in the figure is an annular plate washer.

In a state where the screw member 30 is screwed into the screw hole 13, the head portion 32 of the screw member 30 is pressed against the rake face 7 of the cutting member 2 toward the base end side via the washer 33.
In the illustrated example, when the screw member 30 is screwed into the screw hole 13, the head portion 32 of the screw member 30 protrudes toward the distal end side of the cutting member 2. However, the present invention is not limited to this. It is not a thing. That is, for example, the through hole 5 of the cutting member 2 is formed in a multistage cylindrical hole shape, and the head portion 32 of the screw member 30 is pressed against the stepped portion of the through hole 5 toward the proximal end side. The head 32 may be accommodated in the through hole 5.

  Next, a procedure for attaching the cutting member 2 to the tool body 3 in the clamping mechanism 1 of the cutting member and the blade-part-exchangeable cutting tool 10 using the same according to the present embodiment will be described.

First, as shown in FIG. 8A, the locking member 40 and the nut member 20 are screwed onto the shaft portion 11 of the tool body 3 in this order in advance. At this time, the fitting portion 22 formed on the inner peripheral surface 21 of the nut member 20 is fitted to the fitted portion 16 of the shaft portion 11, so that the nut member 20 and the shaft portion 11 are coaxial (concentric). Is positioned (centered). Further, when the threaded portion 23 formed on the inner peripheral surface 21 of the nut member 20 is threadedly engaged with the threaded portion 15 of the shaft portion 11, the nut member 20 is rotated in the circumferential direction. The nut member 20 can be moved in the direction of the central axis O while the nut member 20 is aligned with respect to the shaft portion 11 of the tool body 3.
Further, the locking member 40 also moves in the direction of the central axis O with respect to the shaft portion 11 by rotation in the circumferential direction by the female screw portion 41 being screwed into the threaded portion 15 of the shaft portion 11. Is possible. Here, the position of the nut member 20 in the central axis O direction with respect to the shaft portion 11 is such that the distal end surface 26 of the nut member 20 is retracted to the proximal end side with respect to the distal end surface 12 of the shaft portion 11. Preferably there is.

  Next, with the tip surface 12 of the shaft portion 11 exposed to the tip side from the nut member 20 in this way, the cutting member 2 is placed on the tip surface 12 to bring the seating surface 8 into contact with the screw member. 30 screw portions 31 are inserted into the through holes 5 of the cutting member 2 and screwed into the screw holes 13 of the shaft portion 11. At this time, the screw member 30 is not tightened strongly, but is temporarily fixed so that the cutting member 2 can move in the radial direction by receiving an external force.

  Next, when the nut member 20 is rotated with respect to the shaft portion 11 of the tool body 3 and is moved toward the distal end side in the direction of the central axis O, as shown in FIG. The second taper surface 24 is brought into contact with the first taper surface 6b of the cutting member 2, and the nut member 20 is further tightened so that the taper surfaces 24 and 6b are fitted to each other while being in sliding contact with each other. It is done. With this fitting, the cutting member 2 is aligned with the nut member 20.

  Specifically, the cutting member 2 is centered with respect to the nut member 20 on the basis of the first taper surface 6b of the outer peripheral surface 6, so that the center (center of the cutting edge 4 formed on the outer peripheral surface 6 is centered. When viewed from the front end side in the direction of the axis O, the cutting edge 4 has a circumferential shape and its center) is aligned with the nut member 20 and the shaft portion 11 of the tool body 3.

Next, as shown in FIG. 4, the locking member 40 is rotated by rotating the locking member 40 relative to the shaft portion 11 of the tool body 3 and moving the locking member 40 toward the distal end side in the direction of the central axis O. The distal end surface 42 of the nut member 20 is brought into contact with the proximal end surface 27 of the nut member 20 toward the distal end side.
In this way, the cutting member 2, the nut member 20, and the shaft portion 11 of the tool main body 3 are all aligned with each other, and the screw member 30 is further tightened from this state, whereby the cutting member 2 becomes the shaft portion 11 of the tool main body 3. Fixed against.

  According to the cutting member clamping mechanism 1 of the present embodiment described above and the blade part exchangeable cutting tool 10 using the same, as described above, the center of the cutting edge 4 of the cutting member 2 is the shaft part 11 of the tool body 3. Since the roundness in the rotation trajectory around the center axis O of the cutting edge 4 is sufficiently increased, the tool body 3 is cut around by the cutting member 2 while being rotated around the center axis O. This ensures stable machining accuracy and high quality.

  Further, when the nut member 20 is rotated with respect to the shaft portion 11 of the tool body 3 and the second tapered surface 24 and the first tapered surface 6b are fitted, the amount of rotation of the nut member 20 is adjusted as appropriate. It is possible. That is, unlike the present embodiment, for example, as shown in FIG. 20 of JP-T-2011-506111, the cutting member cannot be aligned and fixed to the shaft portion of the tool body unless the screw member is tightened to the end. In the case of the conventional configuration, this tightening may cause plastic deformation of a member (sleeve 2025) corresponding to the nut member shown in the drawing. On the other hand, according to the present embodiment, when the cutting member 2 can be aligned with the shaft portion 11 of the tool body 3, it is not necessary to screw the nut member 20 further, and thus the plasticity of the nut member 20 is not necessary. Deformation can be prevented. Therefore, highly accurate cutting can be stably maintained over a long period of time.

  Further, since the cutting member 2 is centered with respect to the nut member 20 with the outer peripheral surface 6 as a reference, the dimensional accuracy at the time of manufacturing the cutting member 2 can be set relatively slowly. Specifically, when a sintered body made of cemented carbide or the like as described in the present embodiment is used as the cutting member 2, a slight molding error or processing error (predetermined) is added to the outer diameter of the cutting member 2. The actual outer diameter is slightly larger or smaller than the outer diameter of the cutting member 2. However, in such a case, high-precision centering is possible, and the center of the through hole 5 of the cutting member 2 is the central axis. Even if it is slightly deviated from O, high-precision alignment is possible without being affected by this.

Further, the cutting member 2 is left as a sintered surface without requiring strict processing accuracy for polishing the first tapered surface 6b on the outer peripheral surface 6 of the cutting member 2 or without polishing the first tapered surface 6b. It is possible to use. Therefore, manufacture of the cutting member 2 is easy.
In particular, even when a slight molding error or machining error occurs in the outer diameter of the cutting member 2, as described above, it can be easily handled by adjusting the amount of rotation of the nut member 20 as appropriate, and the core can be easily adjusted. Can be combined.

  As described above, according to the present embodiment, the shaft 11 of the tool body 3 can be formed using a simple structure without requiring strict accuracy in the outer diameter of the cutting member 2 and without complicating the manufacture. On the other hand, the cutting member 2 can be centered accurately and easily, and can be fixed stably, and high-quality cutting can be maintained over a long period of time.

  Further, since the locking member 40 that is screwed to the shaft portion 11 of the tool body 3 is provided, the nut member 20 is fitted to the cutting member 2 as described above, and then the shaft of the tool body 3 is fitted. By rotating the locking member 40 around the central axis O with respect to the portion 11 and moving the locking member 40 toward the distal end side, and abutting against the nut member 20 from the proximal end side, an action of a double nut can be obtained, and the nut member 20 can be easily and reliably prevented from loosening.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, a rotation restricting portion that restricts relative rotation around the central axis O between the cutting member 2 and the shaft portion 11 of the tool body 3 may be provided. Specifically, for example, in FIG. 4, the seating surface 8 of the cutting member 2 and the tip surface 12 of the shaft portion 11 of the tool body 3 are each formed of only a flat surface. 12, a concave portion and a convex portion that can be engaged with each other may be formed as the rotation restricting portion.

In this case, when the cutting member 2 is attached to the shaft portion 11 of the tool body 3 or during cutting, the cutting member 2 rotates unintentionally in the circumferential direction with respect to the shaft portion 11 of the tool body 3. This is prevented.
Therefore, the workability when the cutting member 2 is attached to and detached from the shaft portion 11 of the tool body 3 is improved, and the cutting can be performed with high accuracy and stability.

Moreover, the blade part exchange-type cutting tool 10 demonstrated in the above-mentioned embodiment is the cutting member 2 which is an annular | circular (disc shape) round piece insert, and the axial tool to which the cutting member 2 is mounted | worn detachably. Although the main body 3 is provided and the tool main body 3 is rotated about its axis and is cut into a rotating work material and turned, the present invention is not limited to this.
That is, for example, the blade-exchangeable cutting tool 10 has a cylindrical shape in which a through-hole 5 is formed along the central axis O, and the cutting member 2 that is a cutting head having a cutting edge 4 on at least the outer peripheral surface 6; The tool main body 3 to which the cutting member 2 is mounted may be provided, and the tool main body 3 may be a head replaceable end mill that cuts and cuts into a fixed work material while rotating around the axis of the tool main body 3.
Moreover, the tool main body 3 should just have the axial part 11 as a front-end | tip part, and the whole shape is not limited to the axial shape mentioned above.

In addition, the cutting edge 4 of the cutting member 2 is formed at the tip edge of the outer peripheral surface 6. However, when the cutting member 2 is a cutting head for an end mill, the cutting edge 4 is 6 may be formed as a whole. In this case, the rotation trajectory of the cutting edge 4 improves not only the roundness but also the cylindricity by the configuration of the present invention.
The cutting member 2 has the cutting edge 4 on at least the outer peripheral surface 6, so that the above-described remarkable effect can be obtained, but the cutting edge 4 is not only the outer peripheral surface 6 of the cutting member 2, It may also be formed on the front end surface of the cutting member 2.

  In the above-described embodiment, the outer peripheral surface 6 of the cutting member 2 is formed in a multistage shape. However, the present invention is not limited to this, and for example, between the flank 6a and the first tapered surface 6b. These may be formed in a single piece without being provided with stepped portions.

In the above-described embodiment, the locking member 40 has an annular shape whose length along the central axis O direction is shortened. However, the locking member 40 has a cylindrical shape that is long in the central axis O direction. May be.
Instead of providing the locking member 40, for example, the nut member 20 is inserted (screwed) in the radial direction and is locked to a flat portion (D cut portion) formed on the outer peripheral surface of the shaft portion 11. Locking means such as a clamp screw may be used.

In the above-described embodiment, the screwed portion 15 and the fitted portion 16 having a smaller diameter than the screwed portion 15 are directed toward the distal end side on the outer peripheral surface of the shaft portion 11 of the tool body 3. Corresponding to this, on the inner peripheral surface 21 of the nut member 20, the screwing portion 23 and the fitting portion 22 are arranged in this order toward the distal end side. However, the present invention is not limited to this.
That is, on the outer peripheral surface of the shaft portion 11 of the tool body 3, the fitted portion 16 and the screwed portion 15 having a smaller diameter than the fitted portion 16 are arranged in this order toward the distal end side. Correspondingly, on the inner peripheral surface 21 of the nut member 20, the fitting portion 22 and the screwing portion 23 may be arranged in this order toward the distal end side.

DESCRIPTION OF SYMBOLS 1 Clamping mechanism of cutting member 2 Cutting member 3 Tool main body 4 Cutting blade 5 Through-hole 6 Outer peripheral surface 6b 1st taper surface 8 Seating surface 10 Blade part exchange-type cutting tool 11 Shaft part 12 Tip surface 13 Screw hole 20 Nut member 21 In Peripheral surface 22 Fitting portion 23 Threaded portion 24 Second tapered surface 30 Screw member 40 Loosening prevention member O Center axis

Claims (4)

A cutting member having an annular shape or a cylindrical shape in which a through-hole along the central axis is formed, and having a cutting edge on at least the outer peripheral surface;
A shaft portion of a tool body that has a distal end surface that is in contact with a seating surface facing the proximal end side in the central axis direction of the cutting member and that faces the distal end side in the central axis direction;
A nut member having a cylindrical shape, a fitting portion fitted to the shaft portion of the tool main body on the inner peripheral surface thereof, and a screwing portion screwed to the shaft portion;
A screw member that is inserted through the through hole of the cutting member and is screwed into a screw hole formed in the tip surface of the shaft portion, so that the cutting member is detachably fixed to the shaft portion. ,
On the outer peripheral surface of the cutting member, a first tapered surface that gradually decreases in diameter toward the proximal end side is formed,
A clamp for a cutting member, wherein the inner peripheral surface of the nut member is formed with a second taper surface that gradually increases in diameter toward the tip end side and is fitted to the first taper surface. mechanism. A clamping mechanism for a cutting member according to claim 1,
A clamping mechanism for a cutting member, characterized in that an annular or cylindrical locking member that is screwed into a shaft portion of the tool main body and is capable of coming into contact with the nut member from the base end side is provided. A clamping mechanism for a cutting member according to claim 1 or 2,
A clamping mechanism for a cutting member, wherein a rotation restricting portion for restricting relative rotation around the central axis between the cutting member and a shaft portion of the tool body is provided. A cutting member;
A cutting tool having a shaft portion on which the cutting member is detachably mounted, and a tool body rotated around the shaft,
The blade part exchange-type cutting tool using the clamping mechanism of the cutting member as described in any one of Claims 1-3.

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