JP6755119B2 - Cutting tool tips and their manufacturing methods - Google Patents

Description

This aspect relates to a tip constituting a cutting tool blade and a method for manufacturing the tip.

An insert type (replaceable cutting edge type), a so-called insert (throw away tip), which is attached to a cutting tool to form a blade portion, is known. Such a cutting tool tip is generally formed by pressing a mixture of a raw material powder made of a relatively hard material and a raw material powder serving as a bonding phase component of the hard raw material powder by a mold, and then forming the tip. , Formed by firing.

Further, there is also known a method of manufacturing a chip by laminating two molded members instead of integrally molding the entire chip (Patent Documents 1 to 3). Patent Documents 1 to 3 disclose that convex portions and concave portions that are fitted to each other are formed on the surfaces of the two members that are bonded to each other, thereby aligning the two members.

Japanese Unexamined Patent Publication No. 5-285708 Japanese Unexamined Patent Publication No. 2014-121770 U.S. Patent Application Publication No. 2013/0195569

The cutting tool tip as described above is fixed to the holder, for example, by screwing a screw inserted into the through hole into the holder (shank). If the accuracy of the through hole is reduced, the insert is not positioned at the intended position with respect to the holder, and as a result, the accuracy of cutting by the insert may be reduced.

Therefore, it is desired to provide a cutting tool tip and a method for manufacturing the same, which can reduce the influence of bonding on the accuracy of the through hole.

The cutting tool tip according to one aspect includes a first outer surface, a first inner surface on the back surface thereof, and a first member having a first hole penetrating from the first outer surface to the first inner surface. A second outer surface, a second inner surface on the back surface thereof, and a second member having a second hole penetrating from the second outer surface to the second inner surface, and said the first. The first inner surface and the second inner surface face each other so that the first hole and the second hole form one through hole, and the first inner surface opens the first hole. The convex portion has a frame-shaped convex portion, and the convex portion has a first inclined surface so that the width becomes narrower as the distance from the first outer surface increases, and the second inner surface surface thereof is the second inner surface. It has a frame-shaped recess having a hole as an opening, and the recess has a second inclined surface so that the width becomes narrower as it approaches the second outer surface, and the first inclined surface and the first inclined surface. The two inclined surfaces face each other.

Preferably, the convex portion has a top surface surrounding the first hole, the recess has a bottom surface surrounding the second hole, and the top surface and the bottom surface face each other. doing.

Preferably, the first inclined surface has a first region and a second region having an inclined surface length shorter than the first region at positions different from each other in the circumferential direction, and the second inclined surface has the second inclined surface. Has a third region and a fourth region having an inclined surface length shorter than the third region at positions different from each other in the circumferential direction, and the first region and the third region face each other. The second region and the fourth region face each other.

Preferably, the first region and the third region have a larger inclination angle with respect to the central axis than the second region and the fourth region.

Preferably, the through hole at the position where the convex portion and the concave portion face each other has an elliptical shape in a cross section orthogonal to the central axis.

Preferably, the first inner side surface and the second inner side surface have a shape having a longitudinal direction and a lateral direction orthogonal to the longitudinal direction in a plan view, and the convex portion is the first in the lateral direction. It is smaller than one inner side surface and extends over the entire first inner side surface in the longitudinal direction, and the recess is smaller than the second inner side surface in the lateral direction and said in the longitudinal direction. It extends over the entire second inner surface.

Preferably, the outer peripheral side surface of the cutting tool tip has a first side surface and a second side surface having a shorter distance from the through hole than the first side surface, and the first region and the third region are , The second region and the fourth region are located between the through hole and the first side surface, and the second region and the fourth region are located between the through hole and the second side surface.

Preferably, at least one of the first inner side surface and the second inner side surface is provided with a notch at an intersecting ridge portion with the adjacent outer peripheral side surface.

The method for manufacturing a cutting tool tip according to one aspect has a first outer surface, a first inner surface on the back surface thereof, and a first hole penetrating from the first outer surface to the first inner surface. A step of forming one member and a second member having a second outer surface, a second inner surface on the back surface thereof, and a second hole penetrating from the second outer surface to the second inner surface are formed. It includes a step and a step of joining the first inner side surface and the second inner side surface so as to form one through hole so that the first hole and the second hole face each other. In the step of forming the first member, a frame-shaped convex portion having the first hole as an opening is formed on the first inner side surface, and the convex portion has a width as the distance from the first outer surface increases. The first inclined surface is formed so as to be narrow, and in the step of forming the second member, a frame-shaped recess having the second hole as an opening is formed in the second inner side surface, and the recess is filled with a frame-shaped recess. The second inclined surface is formed so that the width becomes narrower as it approaches the second outer surface, and in the step of joining, the first inclined surface and the second inclined surface are opposed to each other. The convex portion and the concave portion are fitted.

According to the above aspect, the cutting tool tip can be bonded with high accuracy to obtain a cutting tool tip with high accuracy of the through hole.

The perspective view which shows the insert type cutting tool which concerns on 1st Embodiment. The perspective view which shows the cutting tool tip of the cutting tool of FIG. FIG. 2 is a cross-sectional view taken along the line III-III of FIG. The exploded perspective view which shows typically the structure of the cutting tool tip of FIG. The flowchart which shows the procedure of the manufacturing method of the tip for a cutting tool. 6 (a) to 6 (f) are schematic views for explaining the outline of each step of FIG. The flowchart which shows the modification of the procedure of the manufacturing method of the tip for a cutting tool. A schematic exploded perspective view showing a configuration of a cutting tool tip according to a second embodiment. The schematic disassembled perspective view which shows the structure of the cutting tool tip which concerns on 3rd Embodiment.

(How to use terms)
Some terms related to cutting tools are customarily ambiguous. In the description of the following embodiments, such terms are basically used as follows.

The blade part is used as a term to refer to a relatively small part (for example, a part of an insert) consisting of a rake face, a flank surface and a cutting edge, and a relatively wide part (for example, an insert and its surroundings) on the tip side of a cutting tool. Part) may be used as a term, but in the description of this embodiment, the former is used.

The cutting edge may be used as a term for referring to the ridgeline between the rake face and the flank surface, or as a term for a corner portion (a portion having an area or volume) formed by the rake face and the flank face. However, in the description of this embodiment, the former is used. However, the actual cutting edge is not a line microscopically, as the term "roundness of the cutting edge" implies, and the cutting edge has an area or a volume as long as it is.

The rake face and flank shall mainly refer to the rake face and flank closest to the cutting edge. For example, if the rake face is broadly interpreted, the central side (mounting surface) of the main surface of the cutting tool tip is also a rake face, but such an interpretation shall not be made. The flank may or may not include a so-called margin.

<First Embodiment>
(Cutting tool configuration)
FIG. 1 is a perspective view showing an insert-type cutting tool 1 according to the first embodiment.

The cutting tool 1 is a roughly shaft-shaped member, which is attached to and detached from the holder 3 (shank) attached to the machine tool and the tip side (left side of the paper surface) of the holder 3, and actually comes into contact with the work piece. It has one or more chips 5 (three in the example of FIG. 1) for cutting a machine tool. In the illustrated example, the cutting tool 1 is an end mill, and by rotating around an axis, a work piece can be cut on the tip surface and the outer peripheral surface of the tip.

The tip 5 is attached to the holder 3, for example, by screwing the screw 7 inserted through the tip 5 into a female screw portion (hidden by the tip 5 (not shown)) formed in the holder 3. The holder 3 is formed with, for example, a recess 3r formed of a plurality of surfaces to which a plurality of surfaces (for example, one main surface and two side surfaces) of the chip 5 abut. The tip 5 is positioned by abutting on the surface of the recess 3r.

(Chip configuration)
FIG. 2 is a perspective view showing the chip 5. FIG. 3 is a cross-sectional view taken along the line III-III of FIG.

In FIGS. 2 and 3, etc., a Cartesian coordinate system xyz defined by being fixed to the chip 5 is attached. In the following description, the direction may be described with reference to this coordinate system. The chip 5 may be in either the vertical direction or the horizontal direction, and the dimension in the z-axis direction may be relatively large, but the z-axis direction may be the vertical direction or the thickness direction. is there. Further, when the chip 5 is simply referred to as a plan view, it means to be viewed in the z-axis direction.

The chip 5 is formed, for example, in a substantially rectangular parallelepiped shape, and is the first main surface 9A and the second main surface 9B (hereinafter, simply referred to as “main surface 9” and may not distinguish between the two). It has four side surfaces 11 that connect a pair of main surfaces 9. The entire side surface 11 may be referred to as the outer peripheral side surface 12. The dimensions of the chip 5 may be set as appropriate. As an example, the length of the long side in the plan view is 10 mm or more and 16 mm or less, the length of the short side in the plan view is 6 mm or more and 10 mm or less, and the thickness is 4 mm or more and 6 mm or less.

The side surface 11 located on the long side in a plan view, for example, generally bulges outward as a whole. On the other hand, the side surface 11 located on the short side in the plan view is recessed so as to be the lowest on the central side in the thickness direction as a whole, for example. In addition, these shapes may be appropriately set from various viewpoints such as securing strength and securing a flank.

(Structure of blade)
The insert 5 has, for example, a long side blade portion 13L and a short side blade portion 13S (hereinafter, simply referred to as “blade portion 13”, which may not be distinguished from each other) that directly participate in cutting the work material. ing. These blade portions 13 are located at the corners (that is, the intersecting ridges) between the main surface 9 and the side surface 11. Specifically, the long side blade portion 13L is provided along the long side in the plan view, and the short side blade portion 13S is provided along the short side in the plan view. The long side blade portion 13L and the short side blade portion 13S are connected by connecting the corner portions of the long side and the short side in a plan view as corners 21 (nose).

The combination of the long side blade portion 13L and the short side blade portion 13S is provided, for example, on each of the pair of main surfaces 9, and on each main surface 9, it is provided on two corner portions located on one diagonal line. There is. That is, a total of four combinations of the long side blade portion 13L and the short side blade portion 13S are provided. In a plan view, the diagonal line provided with the blade portion 13 on the one main surface 9 side and the diagonal line provided with the blade portion 13 on the other main surface 9 side intersect.

Therefore, by rotating the tip 5 by 180 ° around the z-axis and / or 180 ° around the x-axis, four sets of blades 13 can be used (can be used four times).

The combination of the plurality of sets of the long side blade portion 13L and the short side blade portion 13S has, for example, the same shape as each other. That is, the chip 5 has a shape that is 180 ° rotationally symmetric about the z-axis and 180 ° rotationally symmetric about the x-axis.

Each blade portion 13 has a rake surface 15 which is a main body for cutting, a flank surface 17 which is released to avoid unnecessary contact with the cut finished surface, and a cut where the rake surface 15 is connected to the flank surface 17. It has a blade 19.

The blade portion 13 is formed so as to project in the thickness direction (z-axis direction) with respect to the main surface 9 (the central region thereof), for example. Specifically, for example, the rake face 15 is continuous with the main surface 9 and is formed so as to rise from the main surface 9 in the thickness direction. Further, for example, the flank 17 is continuous with the side surface 11 and extends beyond the main surface 9 in the thickness direction. Further, for example, the cutting blade 19 has a higher height from the main surface 9 toward the corner 21 side.

In the vertical cross section as shown in FIG. 3, the presence / absence of inclination, the inclination direction, and the inclination angle of the rake face 15 and the flank surface 17 with respect to the thickness direction (z-axis direction) may be appropriately set. In the illustrated example, the rake face 15 is inclined with respect to the thickness direction so as to be located outside the xy plane toward the cutting edge 19 side, and the flank surface 17 is located inside the xy plane toward the cutting edge 19 side. It is inclined with respect to the thickness direction. The inclination angle with respect to the thickness direction is different from the rake angle and the clearance angle.

As described above, in the present embodiment, since the blade portion 13 protrudes from the main surface 9, the chip 5 includes the base portion 23 having the main surface 9 and the side surface 11 and the blade portion 13 protruding from the base portion 23. May be considered to have.

(Composition of mounting holes)
The tip 5 has a through hole. The through hole is, for example, a mounting hole 25 through which the screw 7 is inserted. As shown in FIG. 3, the mounting hole 25 accommodates the screw head 7b of the screw 7, and the first receiving portion 27A and the second receiving portion 27B with which the screw head 7b is engaged (hereinafter, simply referred to as “receiving portion 27”). It may not distinguish between the two) and an insertion portion 29 through which the male screw portion 7a of the screw 7 is inserted. The receiving portion 27 is provided on both main surface sides, and the insertion portion 29 is provided between them. That is, the tip 5 can be used by rotating it by 180 ° around the x-axis, and the screw 7 can be inserted from any of the pair of main surfaces 9.

The shape and area of the insertion portion 29 in the cross section (xy cross section) are constant in the penetration direction (z-axis direction). The width of the insertion portion 29 in the direction orthogonal to the penetration direction is constant in the cross section along the penetration direction. The receiving portion 27 extends from the insertion portion 29 to the outer side of the mounting hole 25 while increasing the area of the cross section (xy cross section). In the cross section along the penetration direction, the receiving portion 27 has a larger width in the direction orthogonal to the penetration direction from the insertion portion 29 to the outer side of the through hole. Although not particularly shown, the shape of the cross section of the insertion portion 29 and the receiving portion 27 is circular at any position in the z-axis direction, for example. The maximum diameter of the receiving portion 27 is equal to or larger than the diameter of the screw head 7b. Further, the diameter of the insertion portion 29 (the minimum diameter of the receiving portion 27) is smaller than the diameter of the screw head 7b and larger than the diameter of the male screw portion 7a.

Therefore, when the screw 7 is inserted into the mounting hole 25 and screwed into the female screw portion (not shown) of the holder 3, the screw head 7b is positioned on the inclined inner surface of the receiving portion 27 according to the diameter of the screw head 7b. Engage with. Further, the male screw portion 7a is in a state of being inserted into the insertion portion 29 through a predetermined margin (play).

The inner surface of the receiving portion 27 may be linear or curved when the vertical cross section (cross section parallel to the z-axis) is viewed, and as illustrated in FIG. The portion may have a portion parallel to the penetrating direction. The depth of the receiving portion 27 is preferably a depth that can accommodate the entire screw head 7b, but it does not have to be such a depth. The inner surface of the insertion portion 29 is, for example, a straight line substantially parallel to the penetrating direction when the vertical cross section is viewed. However, the inner surface of the insertion portion 29 may have some undulations.

(Chip bonding structure)
FIG. 4 is an exploded perspective view schematically showing the configuration of the chip 5.

As shown in FIGS. 3 and 4, the chip 5 is configured by laminating the first member 31A and the second member 31B.

In the following, "first" and "A" are attached to the constituent elements related to the first member 31A, and "second" and "B" are attached to the constituent elements related to the second member 31B. In addition, "first" and "A" and "second" and "B" may be omitted to make no distinction between the two.

The first member 31A and the second member 31B are configured to divide the chip 5 in the penetrating direction of the mounting hole 25. That is, the first member 31A has a first outer surface (hereinafter, may be referred to as a first outer surface 9A) serving as a first main surface 9A, a first inner surface 33A on the back surface thereof, and a first outer surface 9A. It has a first hole 35A that penetrates from the first inner side surface 33A and constitutes a mounting hole 25. Further, the second member 31B includes a second outer surface (hereinafter, may be referred to as a second outer surface 9B) serving as a second main surface 9B, a second inner surface 33B on the back surface thereof, and a second outer surface 9B. Has a second hole 35B that penetrates from the second inner side surface 33B to form a mounting hole 25. Then, the first inner side surface 33A and the second inner side surface 33B are joined to face each other so that the first hole 35A and the second hole 35B are connected to form one through hole (mounting hole 25). There is.

Further, the first member 31A has four first divided side surfaces 37A (the whole of which is referred to as a first divided outer peripheral surface 38A) connecting the first outer surface 9A and the first inner side surface 33A. The second member 31B has four second divided side surfaces 37B (the whole of which is referred to as a second divided outer peripheral surface 38B) connecting the second outer surface 9B and the second inner surface 33B. The side surface 11 is formed by the first divided side surface 37A and the second divided side surface 37B (the outer peripheral side surface 12 is formed by the first divided outer peripheral surface 38A and the second divided outer peripheral surface 38B).

The first inner side surface 33A and the second inner side surface 33B may be bonded to each other by an adhesive (adhesive layer) interposed between them, or they may be directly contacted and bonded to each other. Good. Further, in determining whether or not the manufacturing method according to the present embodiment described later is implemented, the boundary (inner side surface 33) between the first member 31A and the second member 31B is clear in the completed chip 5. It does not have to be. That is, the completed chip 5 may appear to be integrally formed.

(Positioning structure for bonding)
When the first member 31A and the second member 31B are bonded to each other, they intersect each other (specifically, orthogonally) in the bonding direction (penetration direction of the mounting hole 25, z-axis direction) (xy direction). It has the following configuration so that it can be positioned.

The first member 31A has a first fitting portion 39A composed of at least one of a convex portion and a concave portion (one convex portion in the illustrated example) on the first inner side surface 33A. The second member 31B has a second fitting portion 39B formed of at least one of a convex portion and a concave portion (one concave portion in the illustrated example) on the second inner side surface 33B. Then, when the first member 31A and the second member 31B are bonded together, the first fitting portion 39A and the second fitting portion 39B are fitted. As a result, the first member 31A and the second member 31B are positioned with each other in the xy direction.

On the inner side surface 33, the region other than the region where the fitting portion 39 is formed (the region on the outer peripheral side) is, for example, a planar shape orthogonal to the penetrating direction of the mounting hole 25. In the following, although not particularly designated, this planar region may be referred to as a reference surface of the inner surface 33.

Positioning of the first member 31A and the second member 31B in the bonding direction is performed by abutting the reference surfaces of the pair of inner side surfaces 33 directly or indirectly via an adhesive. However, the fitting portion 39 may also contribute to positioning in the bonding direction.

The shape of the two fitting portions 39 may be such that both fitting portions 39 cannot move with each other in at least one direction in the xy plane. In the illustrated example, both shapes are substantially the same as each other, except that concave or convex are opposite to each other. However, for example, both of them do not necessarily have to have the same shape, as is clear from the fact that the convex portion of the circular view in the plan view fitted in the concave portion of the triangular view in the plan view cannot move in the plane direction.

The fitting portion 39 is located in an annular shape around the hole 35 in a plan view. That is, the fitting portion 39 has a frame shape with the hole 35 as an opening. In the present embodiment, the convex portion has a frame shape with the first hole 35A as an opening. Further, the concave portion has a frame shape with the second hole 35B as an opening. In a plan view, the shape of the inner edge of the fitting portion 39 is the same as the shape of the hole 35, and in the present embodiment, it is circular. Further, in a plan view, the shape of the outer edge of the fitting portion 39 may be appropriately set, but for example, it is a similar shape in which the hole 35 and the center (center of gravity of the figure) are matched. In this embodiment, the hole 35 is formed. Concentric circles.

The width from the inner edge to the outer edge of the fitting portion 39 may be appropriately set. For example, the width of the fitting portion 39 may be reduced to the extent that the minimum strength necessary for alignment is secured in the convex first fitting portion 39A, or to the processing limit. On the contrary, the width of the fitting portion 39 may be widened until a part or all of the outer edge of the fitting portion 39 coincides with the outer edge of the inner side surface 33. In the case where the inner edge and the outer edge are similar figures as described above, the width is constant over the entire circumference of the fitting portion 39.

In the illustrated example, the outer edge of the fitting portion 39 is smaller than the outer edge of the inner side surface 33, and the reference surface of the inner side surface 33 is formed in an annular shape surrounding the fitting portion 39 on the outside of the fitting portion 39. .. Further, in the illustrated example, the outer edge of the fitting portion 39 is larger than the outer edge (outer edge having the maximum diameter) on the outer surface 9 of the receiving portion 27 (FIG. 3). Of course, the outer edge of the fitting portion 39 may be smaller than the outer edge of the outer surface 9 of the receiving portion 27.

The three-dimensional shape of the first fitting portion 39A is, for example, a truncated cone (conical truncated cone in the illustrated example) in which the central axis of the first hole 35A and the central axis coincide with each other. That is, the first fitting portion 39A has a first inclined surface 41A which is a side surface (cone surface) of the frustum and a top surface surrounding the first hole 35A. The top surface in this embodiment is the first orthogonal surface 43A which is the upper surface of the frustum and is orthogonal to the through direction (central axis) of the mounting hole 25. The width of the first inclined surface 41A becomes narrower as the distance from the first outer surface 9A increases.

On the other hand, the second fitting portion 39B is formed in a concave shape having a shape that matches the frustum, for example. That is, the second fitting portion 39B has a second inclined surface 41B, which is an inclined inner peripheral surface of the concave portion, and a bottom surface surrounding the second hole 35B. The bottom surface in this embodiment is a second orthogonal surface 43B orthogonal to the through direction (central axis) of the mounting hole 25. The width of the second inclined surface 41B becomes narrower as it approaches the second outer surface 9B.

The inclined surface 41 is a surface that is inclined with respect to the through direction (z-axis direction) of the mounting hole 25. As described above, since the inclined surface 41 is a pyramidal surface or an inner peripheral surface of a concave portion corresponding thereto, the convex first fitting portion 39A becomes thinner toward the tip side, or the concave second fitting portion 39A. The joint portion 39B is inclined so as to become thinner toward the back side. From another viewpoint, the inclined surface 41 is located on one side of the mounting hole 25 in the penetrating direction (in the present embodiment, the positive side in the z-axis direction) toward the outer side in the radial direction about the mounting hole 25.

The inclination angle of the inclined surface 41 with respect to the penetrating direction may be appropriately set, and is, for example, 20 ° or more and 70 ° or less. As can be understood from FIG. 3, from the viewpoint of ensuring the strength of the first fitting portion 39A by thickening the convex first fitting portion 39A on the root side, the inclined surface 41 is inclined with respect to the penetrating direction. The angle is preferably equal to or greater than the inclination angle of the first receiving portion 27A with respect to the penetrating direction. The inclination angle is, for example, constant over the entire circumference of the inclined surface 41. The inclined surface 41 may be linear in a cross section parallel to the z-axis direction (illustrated example), or may be curved.

The outer edge of the inclined surface 41 is the outer edge of the fitting portion 39, and is concentric circles of the mounting holes 25 in the present embodiment as described above. The inner edge of the inclined surface 41 (outer edge of the orthogonal surface 43) has, for example, a similar shape in which the inner edge and the center (center of gravity of the figure) are aligned, and is circular in the present embodiment. Therefore, in the present embodiment, the inclined surface 41 is a circular ring in a plan view, and its width is constant over the entire circumference. The specific value of the width of the inclined surface 41 may be appropriately set.

The orthogonal surface 43 is a plane orthogonal to the through direction of the mounting hole 25. The shape of the inner edge thereof is the same as the shape of the opening of the hole 35 to the inner side surface 33, and is circular in the present embodiment. The shape of the outer edge of the orthogonal surface 43 is the shape of the inner edge of the inclined surface 41 described above, and in the present embodiment, it is a concentric circle of the inner edge of the orthogonal surface 43. Therefore, in the present embodiment, the orthogonal plane 43 is a circular ring shape, and its width is constant over the entire circumference. The specific value of the width of the orthogonal plane 43 may be set as appropriate.

The first inclined surface 41A and the second inclined surface 41B have, for example, substantially the same shape over the entire surface, and are bonded to each other over the entire surface. The first orthogonal plane 43A and the second orthogonal plane 43B have, for example, substantially the same shape over the entire surface, and are bonded over the entire entire surface. The chip 5 of the present embodiment has the first inclined surface 41A and the second inclined surface 41B described above. Therefore, it is possible to reduce the influence of the bonding at the time of forming the chip 5 on the accuracy of the through hole. That is, the accuracy of the through hole is improved in the chip 5 formed by bonding.

(Chip division position)
As shown in FIG. 3, the seams (that is, the inner edges of the two orthogonal surfaces 43) of the two inner side surfaces 33 (more specifically, the two orthogonal surfaces 43) exposed to the mounting holes 25 are the joints of the mounting holes 25. It is located at the insertion portion 29. The seam may be located at any position of the insertion portion 29. For example, the seam may be located at the center of the insertion portion 29 in the penetrating direction, may be located on the first member 31A side (convex portion side) with respect to the center, or may be located on the second member. It may be located on the 31B side (recessed side) (illustrated example). From the viewpoint of ensuring the thickness (strength) of the convex first fitting portion 39A, the seam is preferably located on the second member 31B side.

Further, the seam may be located at the boundary between the insertion portion 29 and the receiving portion 27. In the description of this embodiment, it is assumed that this boundary is a part of the insertion portion 29. That is, when the seam is located at the insertion portion 29, it is assumed that the seam is located at the boundary between the insertion portion 29 and the receiving portion 27.

The seams exposed on the outer peripheral side surfaces 12 of the two inner side surfaces 33 (more specifically, the reference surface on the outer peripheral side) may be at appropriate positions in the thickness direction. From another viewpoint, when the thickness of the first member 31A and the second member 31B is defined by the distance in the z-axis direction between the reference surface on the outer peripheral side of the inner surface 33 and the outer surface 9 (planar region on the center side), The thicknesses of the first member 31A and the second member 31B may be the same or different from each other. When the first fitting portion 39A is composed of only the convex portion and the second fitting portion 39B is composed of only the concave portion as in the present embodiment, the second member 31B is preferably more than the first member 31A. thick. In this case, for example, when the thickness including the fitting portion 39 is taken into consideration, it is easy to secure the thickness of both the first member 31A and the second member 31B, and by extension, it is easy to secure the strength of both.

(Notch on outer circumference)
In at least one of the first member 31A and the second member 31B (both in the present embodiment), a chamfer shape 45 (first chamfer shape 45A and second chamfer shape 45B) is formed at a corner between the inner side surface 33 and the divided outer peripheral surface 38. ) Is provided.

The chamfered shape 45 uses the term chamfered for convenience of explanation, but the method of forming the chamfered shape 45 is not limited to the one in which the corners are cut. For example, the chamfered shape 45 may be formed at the time of molding by the mold. From another point of view, the term chamfered shape is not a term for a manufacturing process.

The chamfer shape 45 is provided, for example, over the entire outer edge of the inner side surface 33. The chamfered shape 45 may be a flat surface (for example, C surface) or a curved surface (for example, R surface). The width, inclination angle and / or curvature of the chamfer shape 45 may be appropriately set.

Since the chamfer shape 45 is provided on the outer edge of the inner side surface 33, a notch 47 is formed on the outer peripheral side surface 12 of the chip 5 as shown in FIG. Since the notch 47 is formed by the chamfered shape 45, the notch 47 has a shape that becomes wider toward the outside. Further, as can be understood from the description of the chamfer shape 45, the notch 47 extends over the entire circumference of the chip 5, for example, and its size, inclination angle, / or curvature and the like are appropriately set. Good.

(Chip manufacturing method)
FIG. 5 is a flowchart showing the procedure of the manufacturing method of the chip 5. 6 (a) to 6 (f) are schematic views for explaining the outline of each step of the manufacturing method of the chip 5. The manufacturing method proceeds in order from FIG. 6 (a) to FIG. 6 (f). In the following, the same reference numerals may be used for convenience even if the shape or material of the member changes as the manufacturing process progresses.

First, in step ST1 of FIG. 5, the first molded body 55A to be the first member 31A (FIG. 6 (c) is molded. Specifically, for example, it is shown in FIGS. 6 (a) and 6 (b). As described above, the raw material 51 is pressed by the first divided type 53A to the fourth divided type 53D (hereinafter, simply referred to as "divided type 53", and these may not be distinguished).

The number, arrangement, division position, role (movement), and the like of the plurality of division types 53 may be appropriately set. In the illustrated example, the first split type 53A forming the first outer surface 9A of the first member 31A and the second split type 53B forming the first inner side surface 33A of the first member 31A are the first member 31A. The raw material 51 is pressed by being close to the third split type 53C forming half of the outer peripheral side surface 12 and the fourth split type 53D forming the other half of the outer peripheral side surface 12. Unlike the illustrated example, only one of the first split type 53A and the second split type 53B may be moved.

The inner peripheral surface of the first hole 35A is formed by, for example, at least one inner surface of the first divided type 53A and the second divided type 53B (in the illustrated example, the inner surface of the first divided type 53A) which are close to each other. In addition, unlike the illustrated example, a part or all of the first hole 35A penetrates at least one of the first split type 53A and the second split type 53B to guide the one split type. It may be formed by a guide shaft (which may also be regarded as a kind of split type). Further, the first hole 35A may not be formed at the time of molding, but may be formed by punching, cutting and / or cutting after molding.

Further, although not particularly shown, molding may be performed by injection molding in which the raw material 51 is injected into a mold that has been molded, instead of pressing. The mold in this case is the same as the plurality of split molds 53 described above, except that the flow paths (for example, sprue, runner and gate) for injecting the raw material 51 into the mold are formed at appropriate positions. The same may be applied. The same applies to the method for forming the first hole 35A.

The raw material 51 can be obtained, for example, by mixing a relatively hard raw material powder as a main component, a raw material powder as a bonding phase component of the hard raw material powder, and an organic substance such as a binder. The raw material 51 for pressing may be mixed, dried, and then molded. As the raw material 51 for injection molding, as an organic substance such as a binder, a material that can impart appropriate fluidity to the raw material 51 and impart shape retention to the molded body may be selected and injected without being dried.

Taking the case where the chip 5 is made of cemented carbide as an example, the raw material powder contains tungsten carbide as a main component, cobalt as a bonding phase component, tantalum carbide and titanium carbide. Examples of the binder or those having a role similar to the binder include paraffin or an appropriate type of resin. The chip 5 is not limited to cemented carbide, and is, for example, a diamond sintered body, a CBN (Cubic Boron Nitride) sintered body, a ceramic in a narrow sense, a cermet, or a high-speed tool steel formed by powder metallurgy. It may be powdered high-speed steel).

In step ST2 of FIG. 5, burrs are removed from the first molded product 55A. Specifically, for example, as shown in FIG. 6 (c), it is performed by sandblasting. However, the burrs may be removed not only by sandblasting but also by using, for example, fixed abrasive grains or free abrasive grains.

Burrs occur at the seams of the plurality of split molds 53. In the illustrated example, it occurs at the corners (blade portion 13) of the first outer surface 9A and the first divided outer peripheral surface 38A, and at the corners of the first inner surface 33A and the first divided outer peripheral surface 38A.

FIG. 6C schematically shows how the corners of the first inner surface 33A and the first divided outer peripheral surface 38A are deburred. In this deburring, for example, by setting the working time to be sufficiently long, not only deburring but also the first chamfered shape 45A is formed.

Since the corners of the first outer surface 9A and the first divided outer peripheral surface 38A form the blade portion 13, honing is performed as described later. The burrs on the blade portion 13 can be removed during this honing. Therefore, deburring of the blade portion 13 may be omitted here.

In steps ST3 and ST4 of FIG. 5, in parallel with steps ST1 and ST2, the work performed on the first member 31A is performed on the second member 31B. This work is the same as the molding of the first member 31A except for the specific shape. The above description of steps ST1 and ST2 can be applied to steps ST3 and ST4 by replacing "first" and "A" with "second" and "B" for the components related to the first member 31A. .. Note that FIG. 6D schematically shows how the corners of the second molded body 55B, which is the second member 31B, are chamfered between the second inner side surface 33B and the second divided outer peripheral surface 38B. Has been done.

In step ST5 of FIG. 5, as shown in FIG. 6E, the first molded body 55A and the second molded body 55B are bonded together. For example, the first molded body 55A and the second molded body 55B are brought into direct contact (without an adhesive in between). Since the molded body 55 is still in the state before sintering, it can be directly bonded in this way.

The two molded bodies 55 may be adhered by an adhesive interposed between them. In this case, the adhesive is applied to one of the first inner side surface 33A and the second inner side surface 33B, for example, on the entire surface (including the fitting portion 39). The coating may be done, for example, by screen printing. The material of the adhesive may be an appropriate one, but in the present embodiment, an inorganic adhesive such as a ceramic adhesive is preferable because firing is performed later.

At the time of bonding, the first fitting portion 39A and the second fitting portion 39B are fitted so that the first molded body 55A and the second molded body 55B are aligned.

Specifically, for example, when the convex first fitting portion 39A is inserted into the concave second fitting portion 39B, a part of the first inclined surface 41A and a part of the second inclined surface 41B are formed. Abut and slide. At the time of this sliding, the two fitting portions 39 are aligned in the xy direction by the force acting in the xy direction between the two inclined surfaces 41. That is, the central axis of the first hole 35A approaches the central axis of the second hole 35B. Eventually, the two inclined surfaces 41 abut against each other over the entire circumference (further, the entire surface) thereof, and the two fitting portions 39 (holes 35) are positioned with each other in the xy direction. It should be noted that even if the contact is made over the entire circumference, it is natural that there may be a minute gap due to a processing error.

When the two inclined surfaces 41 abut against each other over the entire circumference, thereby restricting the insertion of the first fitting portion 39A into the second fitting portion 39B, the two orthogonal surfaces 43 may abut against each other. It is preferable that the reference surfaces on the outer peripheral side of the two inner side surfaces 33 also come into contact with each other. However, a minute gap may be formed between the two orthogonal planes 43 and at least one of the two reference planes. Further, unlike the above-mentioned action, at least one of the two orthogonal surfaces 43 and the two reference surfaces abut against each other before the two inclined surfaces 41 abut against each other over the entire circumference, and the two inclined surfaces 41 A minute gap may be formed in a part between them.

The two molded bodies 55 may be positioned in the xy direction by a pin 57 (indicated by a dotted line in FIG. 6E) inserted through the first hole 35A and the second hole 35B. In this case, the two inclined surfaces 41 may contribute to positioning with higher accuracy than the pin 57, for example, by the positioning action due to the contact with each other described above. Conversely, the play between the pin 57 and the hole 35 may be increased.

In step ST6 of FIG. 5, as shown in FIG. 6 (f), the two bonded molded bodies 55 are fired (a heat treatment step is performed). As a result, a sintered body to be the chip 5 is formed. At this time, when the molded body 55 contains a binder, the binder evaporates or burns and is removed from the sintered body.

After that, although not particularly shown, the cutting edge of the sintered body is ground or polished (honing) to adjust the roundness of the cutting edge. As a result, the chip 5 is obtained. Honing is performed, for example, by sandblasting. However, the honing is not limited to sandblasting, and honing may be performed using, for example, fixed abrasive grains or free abrasive grains.

It should be noted that the description of the above procedure is merely an outline of an example, and may be appropriately modified. For example, when the molded product 55 contains a binder, a treatment (temporary firing or the like) for removing a part of the binder from the molded product may be performed at an appropriate time before firing. Further, for example, a hard film may be formed after honing.

(Modified example of manufacturing method)
FIG. 7 is a flowchart showing the procedure of the manufacturing method according to the modified example.

In the flowchart shown in FIG. 5, the two molded bodies 55 were bonded together and then fired. On the other hand, in the flowchart shown in FIG. 7, after firing the two molded bodies 55, the sintered bodies are bonded to each other. Specifically, it is as follows.

In FIG. 7, steps ST1 to ST4 are the same as steps ST1 to ST4 in FIG.

In step ST11, the first molded body 55A is fired, and in step ST12, the second molded body 55B is fired. These steps are the same as in step ST6 of FIG. 5, except that the two molded bodies 55 are not bonded together. The firing of the first molded product 55A and the firing of the second molded product 55B may be performed separately or together.

In step ST13, the sintered body to be the first member 31A and the sintered body to be the second member 31B are bonded together. In this bonding, unlike step ST5 in FIG. 5, it is necessary to interpose an adhesive between the first inner side surface 33A and the second inner side surface 33B. The method of applying the adhesive and the like are as described in the description of step ST5 in FIG. However, unlike step ST5 of FIG. 5, since firing is not performed after step ST13, the adhesive may be an organic adhesive.

Since deburring in steps ST2 and ST4 may be performed before bonding, it may be performed after firing (steps ST11 and ST12). Further, since the honing for finally adjusting the blade portion 13 may be performed after firing, it may be performed before bonding.

In addition, it is the same as in FIG. 5 that a treatment (temporary firing or the like) for removing the binder from the molded product may be performed at an appropriate time before firing.

As described above, in the present embodiment, the chip 5 has a first member 31A and a second member 31B. Each of the first member 31A and the second member 31B has an outer surface 9, an inner surface 33 on the back surface thereof, and a hole 35 penetrating from the outer surface 9 to the inner surface. The first inner surface 33A and the second inner surface 33B are bonded so that the first hole 35A and the second hole 35B form one through hole (mounting hole 25) (joined to face each other). There is).

Then, in the present embodiment, each of the first inner side surface 33A and the second inner side surface 33B has a frame-shaped fitting portion 39 having a hole 35 as an opening, including at least one or the other of the convex portion and the concave portion. The first fitting portion 39A and the second fitting portion 39B are fitted together.

Therefore, for example, the first member 31A and the second member 31B are aligned by the two fitting portions 39 closest to the hole 35 and over the entire circumference of the hole 35. As a result, the positioning of the first hole 35A and the second hole 35B is made highly accurate, and the accuracy of the mounting hole 25 composed of the two holes 35 is improved. That is, the influence of the bonding on the accuracy of the mounting hole 25 is reduced. Then, by improving the accuracy of the mounting hole 25, the positioning accuracy of the tip 5 with respect to the holder 3 is improved, and by extension, the cutting accuracy of the cutting tool 1 is improved.

Further, in the present embodiment, the mounting hole 25 is orthogonal to the insertion portion 29 whose cross-sectional shape orthogonal to the penetration direction is constant in the penetration direction and from the insertion portion 29 to the outside of the mounting hole 25 in the penetration direction. It has a receiving portion 27 extending while increasing the cross-sectional shape to be formed, and the seams of the two inner side surfaces 33 (two fitting portions 39) exposed to the mounting holes 25 are formed in the insertion portion 29. positioned.

Therefore, for example, the alignment can be performed stably. Further, for example, since the two inner side surfaces 33 are not exposed on the inner surface of the receiving portion 27, the possibility that the seam affects the accuracy of the inner surface of the receiving portion 27 is extremely low. For example, there is no possibility that a minute step at the seam will occur on the inner surface of the receiving portion 27. As a result, the accuracy of contact of the screw head 7b with respect to the inner surface of the receiving portion 27 is improved, and the positioning accuracy of the tip 5 with respect to the holder 3 by the screw 7 is improved. As a result, the cutting accuracy of the cutting tool 1 is improved.

Further, in the present embodiment, the first fitting portion 39A has a first inclined surface 41A in the convex portion so that the cross-sectional shape (shape of the xy cross section) orthogonal to the penetrating direction of the mounting hole 25 becomes smaller toward the tip side. Have. The second fitting portion 39B has a second inclined surface 41B in the recess so that the cross-sectional shape orthogonal to the penetrating direction of the mounting hole 25 becomes smaller toward the back side. Then, the first inclined surface 41A and the second inclined surface 41B are bonded to each other (they are joined so as to face each other).

Therefore, the first member 31A and the second member 31B can be positioned with high accuracy. For example, unlike the present embodiment, it is assumed that the outer peripheral surface of the convex portion (first inclined surface 41A) and the inner peripheral surface of the concave portion (second inclined surface 41B) are parallel to the penetrating direction of the mounting hole 25. In this case, in order to fit the convex portion into the concave portion, a gap (so-called play) is required between the outer peripheral surface of the convex portion and the inner peripheral surface of the concave portion. As a result, the positioning accuracy is reduced by the amount of play. However, in the present embodiment, since the convex portion can be inserted into the concave portion without such play, the positioning accuracy is improved.

Further, in the present embodiment, each of the two fitting portions 39 has an orthogonal surface 43 orthogonal to the through direction of the mounting hole 25. Then, the two orthogonal planes 43 are bonded to each other (joined to face each other).

Therefore, for example, the positioning accuracy is improved. Specifically, for example, in the inclined surface 41, the force in the penetrating direction of the mounting hole 25 generated when the first member 31A and the second member 31B are brought close to each other is a component force in the direction orthogonal to the inclined surface 41. It acts on the inclined surface 41 as a component force in the direction along the inclined surface 41, but in the orthogonal surface 43, the force in the penetrating direction of the mounting hole 25 is the force in the direction orthogonal to the orthogonal surface 43 as it is. Acts on 43. That is, on the two orthogonal planes 43 facing each other, the reaction forces are surely applied to each other. As a result, the mounting hole 25 can be stably positioned in the penetrating direction.

Further, in the present embodiment, at least one of the intersecting ridge portion between the first inner surface 33A and the first divided outer peripheral surface 38A and the intersecting ridge portion between the second inner surface 33B and the second divided outer peripheral surface 38B (the present embodiment). By locating the chamfered shape 45 on both sides), a notch 47 is formed on the outer peripheral side surface 12 of the chip 5.

Therefore, for example, in a mode in which the adhesive is interposed between the first inner surface 33A and the second inner surface 33B, when the excess adhesive overflows to the outer peripheral side surface 12, the adhesive projects onto the outer peripheral side surface 12. Is reduced. Further, even when the adhesive does not intervene, for example, the possibility that the seam becomes a protrusion is reduced. As a result, for example, the possibility that the positioning accuracy of the holder 3 on the outer peripheral side surface 12 with respect to the recess 3r is reduced due to the protrusion is reduced. As a result, the risk of deterioration of cutting accuracy by the cutting tool 1 is reduced.

<Second Embodiment>
In the second and subsequent embodiments, the same or similar configurations as those already described may be designated by the same reference numerals as those already described, and the description may be omitted. Even if the configuration corresponding to (similar to) the configuration already described is given a code different from the code attached to the configuration already described, the matters not particularly mentioned are the same as the configuration already described. Is.

FIG. 8 is an exploded perspective view corresponding to FIG. 4, which schematically shows the configuration of the tip 205 for the cutting tool according to the second embodiment.

Similar to the chip 5 of the first embodiment, the chip 205 is configured by laminating the first inner side surface 233A of the first member 231A and the second inner side surface 233B of the second member 231B. However, the shapes of the first fitting portion 239A and the second fitting portion 239B are different from the shapes of the first fitting portion 39A and the second fitting portion 39B of the first embodiment. Others are the same as those in the first embodiment.

The first fitting portion 239A has a frustum shape, for example, like the first fitting portion 39A of the first embodiment. However, unlike the first embodiment, the shape of the bottom surface (the surface on the foot side) of the frustum is non-circular, for example, elliptical. The upper surface of the frustum is circular as in the first embodiment. Therefore, the outer peripheral surface of the first fitting portion 239A (convex portion) is elliptical in any xy cross section except for the boundary with the upper surface. From another viewpoint, the outer peripheral surface (first inclined surface 241A) of the first fitting portion 239A has a different distance (for example, L1 and L2) from the central axis of the first hole 35A (mounting hole 25). The first region 242A-1 and the second region 242A-2 (plurality of regions) are provided at different positions in the circumferential direction.

The second fitting portion 239B has a concave shape corresponding to the frustum, as in the case of the second fitting portion 39B of the first embodiment, for example. However, the shape of the opening surface (the surface on the entrance side) is non-circular, for example, elliptical, unlike the first embodiment. The bottom surface of the recess is circular as in the first embodiment. Therefore, the inner peripheral surface of the second fitting portion 239B (recess) is elliptical in any xy cross section except for the boundary with the bottom surface. From another viewpoint, the inner peripheral surface (second inclined surface 241B) of the second fitting portion 239B has different distances (for example, L1 and L2) from the central axis of the second hole 35B (mounting hole 25). A plurality of third regions 242B-1 and fourth regions 242B-2 are provided at different positions in the circumferential direction.

The first region 242A-1 and the third region 242B-1 are bonded from the inner edge to the outer edge thereof. Similarly, the second region 242A-2 and the fourth region 242B-2 are bonded from the inner edge to the outer edge thereof. Therefore, the first fitting portion 239A and the second fitting portion 239B are positioned so as not to rotate relative to each other around the central axis of the mounting hole 25.

In the description of this embodiment, the term ellipse does not need to be a mathematically accurate ellipse. For example, an ellipse has a continuous change in the orientation of the outer line (that is, it does not have something like a polygonal corner, or straight lines intersect, or straight lines and curves are It has no intersecting parts), the outer line is generally bulging outward or flat (ie it has no inwardly concave part), and is axisymmetric with respect to each of the two orthogonal axes of symmetry. The length along one axis of symmetry is longer than the length along the other axis of symmetry. So, for example, an ellipse may include a straight line connecting both ends of two semicircles (sometimes called an ellipse), or at first glance it looks like a mathematical ellipse, but strictly speaking It may include those whose curvature changes are different from the mathematical ellipse.

Further, since the distances L1 and L2 are distances from the central axis of the mounting hole 25, they are orthogonal to the central axis (not inclined with respect to the xy plane). The outer peripheral surface of the first fitting portion 239A (convex portion) and the inner peripheral surface of the second fitting portion 239B (concave portion) are inclined in this embodiment, and the central axis of the mounting hole 25 depends on the position in the z-axis direction. The distance from is different. When the distances from the central axis are different, the distances L1 and L2 to be compared with each other are assumed to be at the same position in the z-axis direction.

Further, from the viewpoint of restricting the relative rotation around the central axis, it is sufficient to realize a configuration in which the non-circles as described above are fitted to each other at any position in the z-axis direction. Therefore, the first region 242A-1 and the second region 242A-2 (or the third region 242B-1 and the fourth region 242B-2) have different distances from the central axis of the mounting holes 25 over the entire surface thereof. It may be defined as a region (in the present embodiment, a region of the inclined surface 241 that does not include the boundary with the orthogonal surface 43), or a portion of the mounting hole 25 having different distances from the central axis. It may be regarded as an area including. In the description of this embodiment, it is basically the former.

The fitting portion 239 has an orthogonal surface 43 orthogonal to the through direction of the mounting hole 25, similarly to the fitting portion 39 of the first embodiment. The shape of the outer edge (inner edge of the inclined surface 241) of the orthogonal surface 43 is circular, for example, as in the first embodiment. On the other hand, the outer edge of the inclined surface 241 is non-circular. Therefore, the inclination angles of the mounting holes 25 with respect to the penetrating direction are different between the first region 242A-1 and the second region 242A-2. The same applies to the third region 242B-1 and the fourth region 242B-2.

Specifically, the first region 242A-1 and the third region 242B-1, which have a relatively long distance (L1) from the central axis of the mounting hole 25, have a distance (L2) from the central axis of the mounting hole 25. The inclination angle of the mounting hole 25 with respect to the penetrating direction is larger than that of the relatively short second region 242A-2 and the fourth region 242B-2.

The inclined surface 241 may be linear or curved in a vertical cross section (cross section parallel to the z-axis). In the present embodiment, the inclined surface 241 is linear in the vertical cross section, and the inclined angle is constant regardless of the position in the z-axis direction. Therefore, the magnitude relationship of the inclination angle is established on the entire surface of the first region 242A-1 and the second region 242A-2 (or the third region 242B-1 and the fourth region 242B-2).

If the tilt angle is not constant depending on the position in the z-axis direction, the tilt angles may be compared at the same position in the z-axis direction. Further, in this case, the magnitude relationship of the inclination angle is established only in a part of the first region 242A-1 and the second region 242A-2 (or the third region 242B-1 and the fourth region 242B-2). It may be established on the entire surface, and the latter is preferable.

The outer edge (outer peripheral side surface 12) of the chip 5 in a plan view is a first side surface (short side of a rectangle in this embodiment) and a second side surface (main surface) in which the distance from the central axis of the mounting hole 25 is shorter than that of the first side surface. In the embodiment, it has a long side of a rectangle). The first region 242A-1 and the third region 242B-1 are located between the mounting hole 25 and the first side surface, and the second region 242B-1 and the fourth region 242B-2 are the mounting holes 25. It is located between the second side surface.

As already described, the outer peripheral side surface 12 may be formed in a concave shape or a convex shape in a side view. That is, the shape of the outer edge of the chip 5 in a plan view differs depending on the position in the z-axis direction. The first side surface and the second side surface may be defined as portions where the distances from the central axis of the mounting holes 25 are different from each other with a difference larger than the amount of fluctuation depending on the position in the z-axis direction. From another point of view, the range in the plan view of the first side surface and the second side surface so that the first side surface has a longer distance from the central axis of the mounting hole 25 than the second side surface at any position in the z-axis direction. May be defined.

As described above, in the present embodiment, as in the first embodiment, the fitting portion 39 has a frame shape with the hole 35 as an opening, and the inner side surfaces 233 to be bonded to each other are exposed to the mounting hole 25. It has features such as the eyes being located at the insertion portion 29 (FIG. 3) and the fitting portion 239 having an inclined surface 241. Therefore, the same effect as that of the first embodiment is obtained. For example, the influence of bonding on the mounting hole 25 can be reduced.

Further, in the present embodiment, the convex portion of the first fitting portion 239A has a frame shape having the first hole 35A as an opening in a plan view, and the outer peripheral surface of the convex portion is from the central axis of the mounting hole 25. The first region 242A-1 and the second region 242A-2 having different distances are provided at different positions in the circumferential direction. The recess of the second fitting portion 239B has a frame shape with the second hole 35B as an opening in a plan view, and the distances from the central axis of the mounting holes 25 are different from each other in the third region 242B-1 and the fourth region 242B. -2 is held at different positions in the circumferential direction. The first region 242A-1 and the third region 242B-1 are joined to face each other, and the second region 242A-2 and the fourth region 242B-2 are in contact with each other facing each other.

Therefore, for example, as already described, the first fitting portion 239A and the second fitting portion 239B cannot rotate relative to the axis of the mounting hole 25, and the positioning of the first member 231A and the second member 231B Is made with high precision.

Further, in the present embodiment, the first region 242A-1 and the second region 242A-2 constitute the first inclined surface 241A. The third region 242B-1 and the fourth region 242B-2 constitute the second inclined surface 241B. The first region 242A-1 and the third region 242B-1 have a larger inclination angle of the mounting hole 25 with respect to the penetrating direction than the second region 242A-2 and the fourth region 242B-2.

Therefore, for example, when the first fitting portion 239A is inserted into the second fitting portion 239B as in the present embodiment, the longer the distance from the central axis, the more the xy direction due to the sliding of the inclined surface 241. It is possible to preferably perform positioning by increasing the amount of movement of the. Further, if the inclination angle is continuously changed in the circumferential direction, when the first fitting portion 239A is inserted into the second fitting portion 239B, the inclined surface 241 slides in the rotational direction due to sliding. It is also expected that positioning in the rotational direction of both will be performed.

Further, in the present embodiment, the convex portion of the first fitting portion 239A and the concave portion of the second fitting portion 239B are orthogonal to the penetrating direction of the mounting hole 25, and the first region 242A-1 to the fourth region 242B-2. The shape of the cross section (xy cross section) traversing the above is elliptical.

Therefore, for example, as compared with a mode in which the shape of the outer edge of the fitting portion 239 is polygonal (this mode is also included in the present invention), it is not necessary to form the shape of a minute corner portion, and processing is easy. is there. In addition, there is less risk of inconvenience such as deformation occurring at such corners due to stress concentration and the positioning accuracy being lowered due to the deformation. Further, as described above, since the inclination angle of the inclined surface 241 is continuously changed in the circumferential direction, it is easy to eliminate the positional deviation in the rotational direction by sliding the inclined surface 241.

Further, in the present embodiment, the outer edge of the chip in a plan view has a first side surface (short side) and a second side surface (long side) having a shorter distance from the central axis of the mounting hole 25 than the first side surface. ing. The first region 242A-1 and the third region 242B-1, which have a relatively long distance (L1) from the central axis of the mounting hole 25, are located between the mounting hole 25 and the first side surface (short side). The second region 242A-2 and the fourth region 242B-2, which have a relatively short distance (L2) from the central axis of the mounting hole 25, are located between the mounting hole 25 and the second side surface (long side). doing.

Therefore, for example, contrary to the above, the longitudinal direction of the fitting portion 239 is larger than that of the aspect in which the longitudinal direction of the fitting portion 239 is the lateral direction of the chip 5 (this aspect is also included in the present invention). Easy to increase the length. When the length (referred to as r) in the longitudinal direction of the fitting portion 239 becomes longer, the relative rotation angle (θ (rad)) between the first fitting portion 239A and the second fitting portion 239B around the mounting hole 25 is set. ), The amount of movement (r × θ) between the outer edges of the two fitting portions 239 becomes relatively large. As a result, the positioning on the outer edge side of the two fitting portions 239 improves the accuracy of positioning in the rotational direction.

Further, for example, it is advantageous to secure the strength of the first member 231A and the second member 231B as compared with the embodiment in which the longitudinal direction of the fitting portion 239 is the lateral direction of the chip 5. Specifically, for example, in the first member 231A, the convex first fitting portion 239A functions as a rib that increases the moment of inertia of area in the longitudinal direction in which bending deformation is likely to occur. On the other hand, in the second member 231B, for example, the probability that the concave first fitting portion 239A forms a deep recess in the z-axis direction over the entire width (the entire y direction) of the second member 231B is reduced. As a result, the possibility that a yz cross section having an extremely small moment of inertia of area is formed in a part of the longitudinal direction (x direction) where bending deformation is likely to occur is reduced.

<Third Embodiment>
FIG. 9 is an exploded perspective view corresponding to FIG. 4, which schematically shows the configuration of the tip 305 for a cutting tool according to the third embodiment.

Similar to the chip 5 of the first embodiment, the chip 305 is configured by laminating the first inner side surface 333A of the first member 331A and the second inner side surface 233B of the second member 331B. However, the shapes of the first fitting portion 339A and the second fitting portion 339B are different from the shapes of the first fitting portion 39A and the second fitting portion 39B of the first embodiment. Others are basically the same as those in the first embodiment.

Similar to the fitting portion 39 of the first embodiment, the fitting portion 339 is formed in a frame shape including at least a convex portion or a concave portion and having a hole 35 as an opening. Further, similarly to the fitting portion 239 of the second embodiment, it is formed to be non-circular in a plan view, and is provided so that the longitudinal direction substantially coincides with the longitudinal direction of the chip 305. However, the fitting portion 339 is polygonal, and a part of the outer edge coincides with a part of the chip 305. Specifically, it is as follows.

The first fitting portion 339A is formed of a convex portion and has a rectangular shape in a plan view. In a plan view, the long side of the first fitting portion 339A is parallel to, for example, the long side of the chip 5 (the long side of the outer edge of the first inner side surface 333A). Further, the first fitting portion 339A reaches the outer edge of the first inner side surface 333A in the longitudinal direction, and the short side of the first fitting portion 339A is a part of the short side of the first inner side surface 333A. .. That is, the first fitting portion 339A is smaller than the first inner side surface 333A in the lateral direction, and extends over the first inner side surface 333A in the longitudinal direction.

The second fitting portion 339B is formed of a concave portion and has a rectangular shape in a plan view. In a plan view, the long side of the second fitting portion 339B is parallel to, for example, the long side of the chip 5 (the long side of the outer edge of the second inner side surface 333B). Further, the second fitting portion 339B reaches the outer edge of the second inner side surface 333B in the longitudinal direction, and the short side of the second fitting portion 339B is a part of the short side of the second inner side surface 333B. .. That is, the second fitting portion 339B is smaller than the second inner side surface 333B in the lateral direction, and extends over the second inner side surface 333B in the longitudinal direction.

Then, the first fitting portion 339A and the second fitting portion 339B are fitted, and the first member 331A and the second member 331B are positioned with each other. Specifically, the positioning by the fitting portion 339 is performed in the lateral direction (y direction) and the rotational direction thereof. Positioning in the longitudinal direction (x direction) may be performed by, for example, the pin 57 shown in FIG. 6 (e).

Since the fitting portion 339 is non-circular in a plan view, the fitting portion 339 has a plurality of regions on the outer peripheral surface or the inner peripheral surface thereof having different distances from the central axis of the mounting holes 25, as in the second embodiment. It can be understood that it is. For example, the outer peripheral surface of the first fitting portion 339A (convex portion) has a first region 342A-1 and a second region 342A-2 having different distances (for example, L11 and L12) from the central axis of the mounting hole 25. doing. The inner peripheral surface of the second fitting portion 339B (recess) has a third region 442B-1 and a fourth region 442B-2 having different distances (for example, L11 and L12) from the central axis of the mounting hole 25. There is. Then, the first region 342A-1 and the third region 342B-1 are bonded together, and the second region 342A-2 and the fourth region 342B-2 are bonded together.

The first fitting portion 339A has a first inclined surface 341A and a first orthogonal surface 343A, as in the other embodiments. Similarly, the second fitting portion 339B has a second inclined surface 341B and a second orthogonal surface 343B, as in other embodiments. Then, the first inclined surface 341A and the second inclined surface 341B are bonded together, and the first orthogonal surface 343A and the second orthogonal surface 343B are bonded together. Further, although not shown in FIG. 9, the chamfered shape may be located at the corner portion between the inner side surface 333 and the divided outer surface (reference numeral omitted) as in other embodiments.

As described above, in the present embodiment, as in the first embodiment, the fitting portion 339 has a frame shape with the hole 35 as an opening, and the inner side surfaces 333 to be bonded to each other are exposed to the mounting hole 25. It has features such as the eyes being located at the insertion portion 29 (FIG. 3) and the fitting portion 339 having an inclined surface 341. Therefore, the same effect as that of the first embodiment is obtained. For example, the influence of bonding on the mounting hole 25 can be reduced. Further, in the present embodiment, as in the second embodiment, since the first fitting portion 339A (convex portion) and the second fitting portion 339B (concave portion) are non-circular, positioning in the rotation direction is also highly accurate. Will be done.

Further, in the present embodiment, the inner side surface 333 has a shape (rectangular in the present embodiment) in which the length in the longitudinal direction (x direction) is longer than the length in the lateral direction (y direction) orthogonal to the longitudinal direction. The first fitting portion 339A (convex portion) is smaller than the first inner side surface 333A in the lateral direction, and extends over the first inner side surface 333A in the longitudinal direction. The second fitting portion 339B is smaller than the second inner side surface 333B in the lateral direction, and extends over the second inner side surface 333B in the longitudinal direction.

Therefore, for example, the fitting portion 339 can be made as long as possible in the longitudinal direction thereof. As a result, the effect of relatively increasing the movement amount (r × θ) with respect to the relative rotation angle (θ) described in the second embodiment is increased, and the positioning accuracy in the rotation direction is improved.

In the first to third embodiments described above, the mounting hole 25 is an example of a through hole, the first hole 35A is an example of a hole portion, and the second hole 35B is an example of a hole portion. The fitting portions 39A, 239A and 339A are examples of convex portions, the second fitting portions 39B, 239B and 339B are examples of concave portions, respectively, and the side surface 11 forming the short side of the chip 5 is the first side surface. As an example, the side surface 11 forming the long side of the chip 5 is an example of the second side surface.

The present invention is not limited to the above embodiments, and may be implemented in various embodiments.

The method of attaching and detaching the tip to and from the holder is not limited to that of a screw, and may be a clamp or a combination of a screw and a clamp. Further, the tip may be fixed to the holder without using the through hole, such as being fixed to the holder by brazing while forming a through hole through which a screw can be inserted.

The tip is not limited to that for end mills. For example, the insert may be for a bite or a drill, or for a milling cutter other than an end mill. The shape of the chip in a plan view is not limited to a rectangle, and may be an appropriate shape such as a circle, a triangle, a rhombus, a square, a pentagon, a hexagon, or an octagon. Further, the chip is not limited to one having a blade portion at a corner between an outer surface (main surface) and an outer peripheral surface (side surface), and may have a blade portion on the outer peripheral surface. The presence or absence of a chip breaker and its shape may be appropriately set. It may be right-handed, left-handed, or both-handed. As mentioned in the embodiments, the material of the chip is also arbitrary.

The through hole is not limited to having receiving portions on both sides of the insertion portion, and may have receiving portions on only one side of the insertion portion.

The first fitting portion is not limited to one composed of one convex portion, and similarly, the second fitting portion is not limited to one composed of one concave portion. For example, each of the first fitting portion and the second fitting portion may have one or more convex portions and one or more concave portions alternately in the circumferential direction of the through hole, or may be centered on the through hole. It may have one or more convex portions and one or more concave portions alternately in a concentric manner. Further, a part of the frame shape (for example, a range of less than 30 ° in the central angle) may be interrupted.

The shape of the fitting portion is not limited to circular, oval and rectangular. For example, it may be a polygon other than a rectangle, or it may be a shape in which a curved line and a straight line are appropriately combined. Further, for example, in the third embodiment, the long sides of the fitting portion 339 may not be parallel to each other, and the planar shape of the fitting portion 339 may be trapezoidal or hexagonal. In this case, even if the fitting portion 339 extends over the entire longitudinal direction of the inner side surface 333 (even if a part of the edge portion of the fitting portion 339 coincides with a part of the edge portion of the inner side surface 333), the x direction. Can be positioned. Further, for example, the diameter of the circular shape of the first embodiment or the elliptical shape of the second embodiment may be increased so that a part of the outer edge of the fitting portion may be a part of the outer edge of the inner side surface. Further, the fitting portion may be composed of only an inclined surface without having an orthogonal surface. For example, the first and second fitting portions may be formed by a cone-shaped convex portion and a concave portion having a corresponding shape.

1 ... Cutting tool, 5 ... Cutting tool tip, 9A ... 1st outer surface, 9B ... 2nd outer surface, 25 ... Mounting hole (through hole), 27 ... Receiving part, 29 ... Inserting part, 31A ... 1st member , 31B ... 2nd member, 33A ... 1st inner surface, 33B ... 2nd inner surface, 35A ... 1st hole, 35B ... 2nd hole, 39A ... 1st fitting part (convex part), 39B ... 2nd fitting Joint portion (recess), 41A ... first inclined surface, 41B ... second inclined surface.

Claims (8)

A first member having a first outer surface, a first inner surface on the back surface thereof, and a first hole penetrating from the first outer surface to the first inner surface.
A second outer surface, a second inner surface on the back surface thereof, and a second member having a second hole penetrating from the second outer surface to the second inner surface.
Have and
The first inner side surface and the second inner side surface are joined to face each other so that the first hole and the second hole form one through hole.
The first inner side surface has a frame-shaped convex portion having the first hole as an opening, and the convex portion has a first inclined surface so that the width becomes narrower as the distance from the first outer surface increases. Have,
The second inner side surface has a frame-shaped recess having the second hole as an opening, and the recess has a second inclined surface so that the width becomes narrower as it approaches the second outer surface. And
The first inclined surface and the second inclined surface are joined so as to face each other.
The convex portion has a top surface surrounding the first hole.
The recess has a bottom surface that surrounds the second hole.
The top surface and the bottom surface are joined so as to face each other .
The first inclined surface has a first region and a second region having an inclined surface length shorter than that of the first region at different positions in the circumferential direction.
The second inclined surface has a third region and a fourth region having an inclined surface length shorter than the third region at different positions in the circumferential direction.
The first region and the third region face each other,
A cutting tool tip in which the second region and the fourth region face each other . The cutting tool tip according to claim 1 , wherein the first region and the third region have an inclination angle of the through hole with respect to the penetrating direction larger than that of the second region and the fourth region. The first inner surface surface and the second inner surface surface have a shape having a longitudinal direction and a lateral direction orthogonal to the longitudinal direction in a plan view.
The convex portion is smaller than the first inner surface surface in the lateral direction, and extends over the entire first inner surface surface in the longitudinal direction.
The cutting tool tip according to claim 1 or 2 , wherein the recess is smaller than the second inner surface in the lateral direction and extends over the entire second inner surface in the longitudinal direction. The outer peripheral side surface has a first side surface and a second side surface having a shorter distance from the through hole than the first side surface.
The first region and the third region are located between the through hole and the first side surface.
The cutting tool tip according to any one of claims 1 to 3 , wherein the second region and the fourth region are located between the through hole and the second side surface. The cutting tool tip according to any one of claims 1 to 4 , wherein the convex portion and the concave portion have an elliptical shape in a cross section orthogonal to the penetration direction of the through hole. The cutting tool tip according to any one of claims 1 to 5 , wherein at least one of the first inner surface surface and the second inner surface surface has a notch at an intersecting ridge portion with an adjacent outer peripheral side surface. .. The through hole has a cross section along the through direction.
An insertion portion having a constant width in a direction orthogonal to the penetration direction,
It has a receiving portion having a large width in a direction orthogonal to the penetrating direction from the insertion portion to the outer side of the through hole.
The cutting tool tip according to any one of claims 1 to 6 , wherein the joint between the convex portion and the concave portion is located at the insertion portion. A step of forming a first member having a first outer surface, a first inner surface on the back surface thereof, and a first hole penetrating from the first outer surface to the first inner surface.
A step of forming a second member having a second outer surface, a second inner surface on the back surface thereof, and a second hole penetrating from the second outer surface to the second inner surface.
A step of joining the first inner surface surface and the second inner surface surface so as to form one through hole with the first hole and the second inner surface facing each other.
Have and
In the step of forming the first member, a frame-shaped convex portion having the first hole as an opening is formed on the first inner side surface, and the convex portion has a width as the distance from the first outer surface increases. A first inclined surface is formed and a top surface surrounding the first hole is formed so that the first inclined surface becomes narrower, and the first inclined surface has a first region and the first region at different positions in the circumferential direction. A second region having a shorter inclined surface length is formed.
In the step of forming the second member, a frame-shaped recess having the second hole as an opening is formed on the second inner side surface, and the width of the recess becomes narrower as it approaches the second outer surface. A second inclined surface is formed and a bottom surface surrounding the second hole is formed so that the second inclined surface is inclined at different positions in the circumferential direction from the third region and the third region. A fourth region with a short surface length is formed,
In the joining step, the first inclined surface and the second inclined surface are brought to face each other so that the first region and the third region face each other and the second region and the fourth region face each other. A cutting tool that fits the convex portion and the concave portion in a state of facing each other, joins the first inclined surface and the second inclined surface, and joins the top surface and the bottom surface so as to face each other. How to make chips for.

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