WO2015002312A1

WO2015002312A1 - Cutting insert, tool body, and cutting tool

Info

Publication number: WO2015002312A1
Application number: PCT/JP2014/067971
Authority: WO
Inventors: 佐治　龍一
Original assignee: 株式会社タンガロイ
Priority date: 2013-07-04
Filing date: 2014-07-04
Publication date: 2015-01-08
Also published as: JP2016163910A

Abstract

Provided is a structure for firmly securing a cutting insert to a tool body. A cutting insert (1) having two end surfaces (2, 3) and a side surface (4) that connects the end surfaces, wherein at least one cutting edge (5) is formed at a crossing ridgeline between at least one (2) of the two end surfaces and the side surface (4). With the end surface on the side on which the cutting edge (5) is formed as the first end surface (2), and the other end surface as the second end surface (3), the side surface includes at least a protruding side surface portion (9) which protrudes outward in a direction from the first end surface (2) to the second end surface (3) and protrudes outward so as to separate from the cutting edge (5) when viewed from a direction facing the first end surface (2). By bringing the protruding side surface portion (9) into contact with a wall surface (23) of an insert seat of a tool body (21), the cutting insert (1) can be firmly secured even if the area of a seating surface of the insert seat becomes small. The cutting insert is firmly secured to a cutting tool.

Description

Cutting inserts, tool bodies and cutting tools

The present invention relates to a cutting insert that is detachably attached to a cutting tool, a tool body for attaching the cutting insert, and a cutting tool including them.

Conventional cutting inserts include those shown in Patent Document 1. That is, a cutting insert having two end faces and a side face connecting the end faces, and the cross ridge line between the end face and the side face has two cutting edges formed on each side, two on each side. It is. Such a cutting insert is mounted on the insert seat of the tool body in a direction rotated by 180 ° in a plane parallel to either end face, and the tool body is turned in the direction that the two end faces are reversed (inverted). By being mounted on the insert seat, the four cutting edges can be selectively used.

International Publication No. 2012/20784 Pamphlet

It is recognized that the cutting insert of Patent Document 1 has a certain effect in clamping so that the cutting insert does not move. However, when trying to apply a small cutting insert corresponding to a rotary cutting tool having a small tool diameter, there is still a point to be improved regarding the clamping performance. That is, in the cutting insert of patent document 1, it is necessary to provide the rake surface which continues from a cutting blade, and the seating surface which seats to the bottom face of an insert seat at the time of reverse mounting | wearing in both end surfaces. Therefore, especially in the case of cutting inserts for small-diameter rotary cutting tools, the dimensions of the cutting inserts are reduced. Therefore, securing the required rake face makes the seating surface area very narrow and the cutting insert is fixed. This is because it tends to be unstable. For this reason, the cutting insert moves during the cutting process, causing problems such as chipping and a roughened machining surface.

An object of the present invention is to provide a structure capable of firmly clamping a cutting insert or a small-sized cutting insert that can be used in a rotated or inverted orientation.

The present invention is a cutting insert (1) having first and second end faces (2, 3) and a side face (4) connecting the end faces (2, 3),
At least one cutting edge (5, 5a) is formed on the intersecting ridge line between the first end surface (2) and the side surface (4),
Said side surface (4) comprises protruding side surface portions (9, 9a),
The projecting side surface portions (9, 9a) project outward from the first end surface (2) toward the second end surface (3), and face the first end surface (2). When viewed from the direction, it protrudes outward as it is separated from the cutting edge (5, 5a).

The present invention is a tool body (21) for detachably mounting a cutting insert (1),
Having at least one insert seat provided with a bottom surface (22), a wall surface (23) and an open surface;
The wall surface (23) is formed with a recessed wall surface portion (24) in contact with the mounted cutting insert (1),
The recessed wall surface portion (24) has an inclination that indents inwardly from the end away from the bottom surface (22) toward the bottom surface (22), and from a direction facing the bottom surface (22). It is characterized in that it dents inward as it moves away from the open surface.

The cutting tool of the present invention is characterized by including the above cutting insert.

According to the present invention, the cutting insert (1) is provided with the protruding side surface portions (9, 9a), while the insert seat wall surface (23) provided on the tool body (21), for example, the recessed wall surface portion (24). Thus, by clamping the protruding side surface portions (9, 9a), the cutting insert (1) can be firmly fixed even if the area of the seating surface is reduced. Therefore, the cutting insert (1) is prevented from moving during cutting, and problems such as chipping and chipping are prevented. Thereby, a rotary cutting tool with a small tool diameter can be realized.

FIG. 1 is a perspective view of a cutting insert according to the first embodiment. FIG. 2 is a perspective view of a cutting tool to which the cutting insert of FIG. 1 is attached. FIG. 3 is a plan view of the cutting insert of FIG. FIG. 4 is a front view of the cutting insert of FIG. FIG. 5 is a right side view of the cutting insert of FIG. FIG. 6 is an explanatory diagram of a virtual plane related to the cutting insert of FIG. 1. FIG. 7 is an enlarged view of the insert seat of the tool body in the first embodiment applicable to the cutting tool of FIG. FIG. 8 is an explanatory diagram of a virtual plane regarding the insert seat of FIG. FIG. 9 is a front view of the cutting tool of FIG. FIG. 10 is an enlarged view showing a cross section taken along line XX of FIG. FIG. 11 is a schematic diagram for explaining a contact state between the cutting insert and the insert seat of the tool body in the cutting tool of FIG. 2. FIG. 12 is a schematic diagram for explaining a contact state between the cutting insert according to the modification of the first embodiment and the insert seat of the tool body according to the first embodiment. FIG. 13 is a schematic diagram for explaining a contact state between a cutting insert according to another modification of the first embodiment and an insert seat of the tool body according to the first embodiment. FIG. 14 is a schematic diagram of a contact state between the cutting insert according to the modification of the first embodiment and the insert seat of the tool body according to the modification of the first embodiment. FIG. 15 is a perspective view of a cutting insert in the second embodiment. FIG. 16 is a plan view of the cutting insert of FIG. FIG. 17 is a front view of the cutting insert of FIG. 18 is a right side view of the cutting insert of FIG.

Embodiments of a cutting insert to which the present invention is applied will be described with reference to the drawings.

1. First Embodiment First, a cutting insert, a tool body, and a cutting tool according to a first embodiment of the present invention will be described with reference to FIGS. In addition, the tool body in this specification is a thing of the form which mounts | wears with a cutting insert so that attachment or detachment is possible, and a cutting tool is comprised by mounting | wearing such a tool body with a cutting insert.
1-1. Cutting Insert As shown in FIGS. 1 and 3 to 5, the cutting insert 1 in the first embodiment has a first end surface 2 and a second end surface 3 which are two end surfaces facing each other. In order to make the following description easy to understand, the first end surface 2 is referred to as an upper surface 2, and the second end surface 3 is referred to as a lower surface 3. In this embodiment, the upper surface 2 and the lower surface 3 both have a pair of opposed acute corners and a pair of obtuse corners, and have a pair of opposed long sides and a pair of short sides. It is a surface of shape. Accordingly, both the upper surface 2 and the lower surface 3 have a contour shape that is 180 ° rotationally symmetric with respect to an axis orthogonal to the surface. Further, the relationship between the

upper surfaces

2 and 3 is a 180 ° rotationally symmetric shape with respect to an axis parallel to the surface.

The upper surface 2 and the lower surface 3 are connected by the side surface 4 over the entire circumference. Two cutting edges 5 are formed at a part of the intersecting ridge line between the upper surface 2 and the side surface 4. Similarly, two cutting edges 5 are formed at a part of the intersecting ridge line between the lower surface 3 and the side surface 4. The cutting insert 1 has a shape in which each cutting edge 5 is formed at a rotationally symmetric position by 180 ° in the plane when viewed in plan (FIG. 3). At the same time, also in the rotational direction in which the upper surface 2 and the lower surface 3 are reversed (inverted), when viewed from the side (FIGS. 4 and 5), the respective cutting edges 5 are formed at 180 ° rotationally symmetric positions. Shape. Therefore, when one cutting edge 5 involved in cutting is worn or damaged by use, the other three cutting edges are removed by removing the cutting insert 1 and reattaching the cutting insert 1 by rotating or reversing it. 5 can be used sequentially. That is, the cutting tool 1 can be used four times in total by appropriately changing the mounting direction to the tool body 21 with one cutting insert 1. As described above, the cutting insert 1 according to the present embodiment is basically formed to have a 180 ° rotationally symmetric shape with respect to rotation or inversion in these four directions. Therefore, the upper surface 2 and the lower surface 3 are end surfaces having the same function. That is, the cutting insert 1 is a cutting insert that has exactly the same shape even when the upper surface 2 and the lower surface 3 are interchanged.

Of course, asymmetry that does not affect the use is acceptable. For example, in order to identify the order in which cutting edges are attached so as to be involved in cutting, an asymmetrical manner in which a number such as “1” to “4” or a mark is added in the vicinity of each cutting edge 5 Sex is acceptable. However, for the sake of convenience, of the two cutting edges 5 on the upper surface 2 side, the one cutting edge 5 drawn at the lower left in FIG. 1 and FIG. The case where the cutting insert 1 is mounted so that the first cutting edge 5a is involved in the cutting process will be described. Even when any one of the other three cutting edges 5 is involved in the cutting, the configuration of the cutting insert 1 of the present embodiment is exactly the same as that of the first cutting edge 5a, and thus the description thereof is omitted.

As shown in FIG. 2, the cutting tool 20 of this embodiment is in the form of a rotary cutting tool capable of processing a right-angle wall surface, that is, a shoulder cutter. The cutting edge 5 of the present embodiment has a main cutting edge 6, a secondary cutting edge 7, and a corner cutting edge 8 across a pair of two sides (long side and short side) that are adjacent to each other through an acute corner. In addition, when specifying the 1st cutting edge 5a, these are referred as the 1st main cutting edge 6a, the 1st sub cutting edge 7a, and the 1st corner cutting edge 8a.

The main cutting edge 6 constituting a part of the cutting edge 5 is formed on the long side of the upper surface 2 and the lower surface 3 of the substantially parallelogram-shaped cutting insert 1 over the entire length of the side. The main cutting edge 6 forms the wall surface of the part to be processed by cutting in the feed direction of the cutting tool 20 parallel to the surface of the workpiece. The auxiliary cutting edge 7 constituting the other part of the cutting edge 5 is formed on a part of the short side of the cutting insert 1. The sub-cutting edge 7 is substantially parallel to the feed direction of the cutting tool 20, and forms the bottom surface of the portion to be processed by performing a cutting process that exposes the surface of the workpiece. The secondary cutting edge 7 is also called a front cutting edge. Further, the sub-cutting blade 7 may be formed with a wiping blade or the like as necessary. A corner cutting edge 8 is formed at an acute corner between the main cutting edge 6 and the sub cutting edge 7. The main cutting edge 6, the corner cutting edge 8, and the sub cutting edge 7 are continuous to form one cutting edge 5. That is, the first cutting edge 5a is constituted by the first main cutting edge 6a, the first corner cutting edge 8a, and the first sub cutting edge 7a being continuous.

In this embodiment, the radius of curvature, the length of the long side, and the length of the short side of the corner cutting edge 8 of the cutting insert 1 are about 0.4 mm, about 9 mm, and about 5 mm, respectively. The thickness of the cutting insert 1, that is, the distance between the upper surface 2 and the lower surface 3 in this case is about 3 mm. The cutting insert having the dimensions exemplified here is a cutting insert that is small as a cutting insert and can be adapted to a shoulder cutter having a small diameter. The present invention enables firm fixation even with such a cutting insert. However, the contour shape and the dimensions of each part exemplified above are not limited, and the contour shape and the dimension of each part of the cutting insert 1 depend on the shape and size of the workpiece to be processed, the tool diameter of the cutting tool 20, and the like. This is a matter that can be appropriately selected.

Furthermore, in this embodiment, the tool diameter of the cutting tool 20 is about 14 mm. In the conventional rotary cutting tool, from the viewpoint of the clamping strength of the cutting insert and the like, it is the limit to reduce the tool diameter to about 16 mm, and it is difficult to make the tool diameter smaller than that. The present invention makes it possible to achieve a cutting tool 20 having a tool diameter of 15 mm or less, exceeding the limits of the prior art, by greatly enhancing the clamping performance of the cutting insert 1 as will be described later. More specifically, it is possible to realize an edge-changeable end mill with a tool diameter of about 14 mm, which can perform right-angle wall machining. The present invention is particularly suitable for a rotary cutting tool having a tool diameter of 40 mm or less. Especially, it is suitable for a small diameter rotary cutting tool having a tool diameter of 20 mm or less. In other words, even with a rotary cutting tool having a tool diameter of 20 mm or less, by providing a rake face with a positive rake angle on both the upper face 2 and the lower face 3, both the upper face 2 and the lower face 3 can be used while cutting. A cutting tool structure capable of using a cutting insert with low resistance is realized.

That is, in the case of a cutting insert having a rake face on both sides, the upper face 2 and the lower face 3 are each provided with a rake face continuous from the cutting edge 5, and a seating face that is seated on the bottom face of the insert seat when reversed. There is a need. Therefore, especially in the case of cutting inserts for small-diameter rotary cutting tools, the dimensions of the cutting inserts are reduced. Therefore, securing the required rake face makes the seating surface area very narrow and the cutting insert is fixed. Prone to instability. The cutting insert 1 and the cutting tool 20 according to the present invention enable the cutting insert 1 to be firmly fixed even if the seating surface area is narrow, and the rotary cutting tool has a small tool diameter exceeding the limit of the conventional cutting tool. Is realized. In addition, about the uneven | corrugated shape itself of a rake face, ie, the shape itself of a chip breaker, various conventional techniques are applicable according to the cutting conditions etc. which are used. Moreover, there is no restriction | limiting in the side which enlarges the tool diameter applied.

The cutting insert 1 has a hole penetrating the center of the upper surface 2 and the lower surface 3. This hole is used when the cutting insert 1 is fixed to the tool body 21 to constitute the cutting tool 20. Both ends of the hole opened on both the upper and lower surfaces have a diameter larger than that of the central portion of the hole penetrating the cutting insert 1. This is because in this embodiment, the cutting insert 1 is fixed to the tool body 21 with a fixing screw. Accordingly, the diameter enlarged portion of the hole has a shape and a size corresponding to the head of the fixing screw, and the head of the fixing screw is brought into contact with the stepped portion formed by the diameter enlarged portion of the hole. . However, the method of fixing the cutting insert 1 to the tool body 21 is not limited to this, and various conventional techniques can be applied. For example, the cutting tool 20 may be configured by fixing to the tool body 21 by a fixing member other than a screw such as a wedge without providing a fixing hole in the cutting insert. However, in the case of using a wedge, it is not necessarily effective for a type in which the wedge is in contact with the upper surface 2 or the lower surface 3 of the cutting insert 1 and the cutting insert 1 is fixed. The present invention is suitable for a type in which the side surface 4 of the cutting insert 1 is pressed against the wall surface of the insert seat of the tool body 21 by the wedge by pressing the side portion of the cutting insert or the concave portion formed on the side surface with the wedge.

As shown in FIG. 1, the side surface 4 of the cutting insert 1 has a portion forming the obtuse corner of the upper surface 2 and the lower surface 3 of the substantially parallelogram (the back side of the portion forming the acute angle corner of the lower surface 3 and the upper surface 2, respectively). Projecting side surface portion 9 is formed. When the cutting insert 1 is mounted on the tool body 21, the projecting side surface portion 9 of the cutting insert 1 abuts on a recessed wall surface portion 24 (FIG. 8) formed on the wall surface 23 of the insert seat of the tool body 21. 1 is fixed. In addition, the protrusion side part 9 which acts as a to-be-fixed part in relation to the 1st cutting edge 5 is referred as the 1st protrusion side part 9a. That is, in FIG. 1 and FIG. 3, the 1st protrusion side surface part 9a corresponding to the 1st cutting edge 5a drawn on the lower left is drawn on the lower right. The protruding side surface portion 9 is formed so as to include a portion that protrudes outward from the end surface on which the protruding side surface portion 9 is provided (that is, one end surface to which the corresponding cutting edge 5 belongs) toward the other end surface. That is, in relation to the first cutting edge 5a on the upper surface 2 side, the first protruding side surface portion 9a is a portion protruding outward from the upper surface 2 toward the lower surface 3.

The protruding side surface portion 9 is formed as an inclined surface. As shown in FIG. 6, when a plane in contact with the protruding side surface portion 9 formed as an inclined surface is a virtual plane A and a plane in contact with the lower surface 3 is a virtual plane B, the virtual plane A and the virtual plane B are internal angles and acute angles. Intersect. Here, the virtual planes in contact with each surface are compared, but strictly speaking, the virtual planes in contact with each other at the contact portion with the insert seat of the tool body may be compared. Of the protruding side surface portion 9, the portion that does not contact the wall surface 23 of the insert seat may have any shape. Therefore, the protruding side surface portion 9 may not be formed by a flat surface. The protruding side surface portion 9 has a portion protruding outward from one end surface to which the corresponding cutting edge 5 belongs to the other end surface, and is in contact with the wall surface 23 of the insert seat in at least a part of the portion. If the cutting insert 1 is formed, the pressing force applied to the bottom surface 22 side of the insert seat effectively acts on the mounted cutting insert 1, so that the cutting insert 1 is prevented from being lifted and moved.

The first protruding side surface portion 9a is formed on a surface opposite to the surface including the flank of the first auxiliary cutting edge 7a when the end surfaces 2 and 3 are regarded as a square and the side surface 4 is divided into four surfaces. The However, the protruding side surface portion 9 is formed at a position shifted from the flank surface of the auxiliary cutting edge 7. As described above, the cutting insert 1 is 180 ° rotationally symmetric with respect to the central axis orthogonal to the upper surface 2. Accordingly, the two sub cutting edges 7 are formed at diagonal positions (that is, positions adjacent to the acute corners in the present embodiment) in the two directions, respectively. The first projecting side surface portion 9a is, with respect to the first cutting edge 5a involved in the cutting process, close to the first main cutting edge 6a, the first auxiliary cutting edge 7a and the first corner cutting edge continuous therewith. It is formed on the opposite side to 8a. Therefore, the first projecting side surface portion 9a effectively applies the force to lift the opposite side of the cutting insert 1 by the cutting force acting on the first sub-cutting edge 7a and the first corner cutting edge 8a continuous therewith. Can be held down.

Next, of the four sides of the substantially parallelogram in plan view, side portions connected to the long side opposite to the long side on which the first main cutting edge 6a involved in the cutting process is formed will be described later. In connection with the main restraint wall surface portion 11 of the insert seat, it is referred to as a main restrained side surface portion and is referred to by the reference numeral 11. Then, as shown in FIG. 6, a plane in contact with the main restrained side surface portion 11 is defined as a virtual plane C. As seen in FIG. 3, the first protruding side surface portion 9a is separated from the long side where the first main cutting edge 6a, which is a part of the corresponding first cutting edge 5a, is formed in plan view. According to the above, it protrudes outward. That is, the first protruding side surface portion 9a faces outward (that is, in the present embodiment, the short side facing the short side provided with the first sub-cutting edge 7a) in the plan view. It intersects at an acute angle with respect to the main constrained side surface portion 11 facing the side surface portion connected to the main cutting edge 6a. That is, the virtual plane A in contact with the first protruding side surface portion 9a and the virtual plane C in contact with the main constrained side surface portion 11 intersect at an acute angle at the inner angle. For this reason, the 1st protrusion side surface part 9a also suppresses the movement of the direction which is going to rotate the cutting insert 1 within a plane by the cutting resistance concerning the corner cutting edge 8 side which follows the 1st main cutting edge 6a. . That is, since both the first protruding side surface portion 9a and the main restrained side surface portion 11 are in contact with the wall surface 23 of the insert seat, it is possible to firmly suppress movement in a direction in which the cutting insert 1 is rotated in a plane. .

In addition, it is preferable that the inclined surface of the protruding side surface portion 9 is formed as a substantially flat surface. According to this, it becomes easy to form the inclined surface of the protruding side surface portion 9 with high accuracy, and it is also easy to contact the recessed wall surface portion 24 of the wall surface 23 of the insert seat in a wide area. If the inclined surface of the protruding side surface portion 9 is a ground grinding surface, the flatness is improved, so that the clamping performance of the cutting insert 1 can be further stabilized. However, it is not limited to this. The cutting insert 1 of this embodiment can be manufactured so as to integrally have the protruding side surface portion 9 as a part of the side surface 23 by, for example, powder pressure molding and sintering.

In the side surface 4, an extended side surface portion 10 is formed on the lower surface 3 side from the protruding side surface portion 9. As described above, the lower surface 3 is the lower surface 3 with respect to the upper surface 2 on which the first cutting edge 5a involved in the cutting process is formed. That is, the lower surface 3 side is a seating surface side seated on the bottom surface 22 of the insert seat. In this embodiment, the extended side surface portion 10 functions as a flank of the auxiliary cutting edge 7 when the cutting edge 5 on the lower surface 3 side acts. The extended side surface portion 10 is continuous with the protruding side surface portion 9 and protrudes further outward. Therefore, when the first cutting edge 5a is mounted so as to be involved in cutting, the auxiliary cutting edge 7 formed on the lower surface 3 is formed at a position further outward than the first protruding side surface portion 9a. By doing in this way, even if a rake surface having a required width is secured on the lower surface 3 side, a sufficient width is secured also on the seating surface on the back surface side of the protruding side surface portion 9. Coupled with the fact that the protruding side surface portion 9 includes the inclined surface, the cutting insert 1 is firmly sandwiched between the inclined surface of the protruding side surface portion 9 and the seating surface, and the clamping performance of the cutting insert 1 is stabilized. In this embodiment, the extended side surface portion 10 is an inclined surface, and the inclination angle with respect to the plane in contact with the lower surface 3 includes a portion having an inclination angle smaller than that of the first protruding side surface portion 9a.

In the present embodiment, the first protruding side surface portion 9a functions as a constrained surface of the cutting insert 2 that is constrained by the wall surface of the cutting insert seat when the first cutting edge 5a is mounted so as to participate in cutting. To do. On the other hand, as described above, the extended side surface portion 10 functions as a flank of the auxiliary cutting edge 7 when the cutting edge 5 on the lower surface 3 side is involved in cutting. In other words, the cutting insert according to the present embodiment is provided with side portions that separate two functions that are required when used and when not used, and perform the separated functions separately. This is advantageous in securing a large clearance surface of the auxiliary cutting edge 7.

1-2. Tool Body and Cutting Tool As shown in FIGS. 7 and 8, the tool body 21 of this embodiment has an insert seat for mounting the cutting insert 1. In this embodiment, the tool body 21 has two insert seats. By mounting the two cutting inserts 1 described above, the cutting tool as shown in FIGS. 2 and 9 is configured. It is not limited. That is, the number of insert seats that the tool body 21 has corresponds to the number of cutting tools 20, that is, the number of cutting inserts 1, but the number of insert seats depends on the tool diameter of the cutting tool 20 and the required machining efficiency. Depending on the case, it is appropriately selected. Further, in this embodiment, the two insert seats have the same shape and size, and the cutting inserts having the same shape and size are formed so as to be evenly arranged around the rotation direction of the cutting tool in the same mounting posture. However, it is not limited to this. The shape, size, and arrangement of the plurality of insert seats can be appropriately determined according to the type of rotary cutting tool, the shape, size, and mounting orientation of the cutting insert. Any one can be used.

Each insert seat has a bottom surface 22 of the insert seat and a wall surface 23 of the insert seat. The seating surface of the upper surface 2 or the lower surface 3 of the cutting insert 1 abuts on the bottom surface 22 of the insert seat. In this embodiment, the bottom surface 22 of the insert seat forms a single plane. However, the present invention is not limited to this, and the bottom surface 22 of the insert seat may be formed in any shape as long as it can contact the seating surface of the cutting insert 1. However, it is desirable that the bottom surface 22 of the insert seat be directly below the first cutting edge 5a involved in the cutting process. Therefore, when viewed from the direction facing the bottom surface 22 of the insert seat, the contour shape of the bottom surface 22 of the insert seat may be a substantially parallelogram. Note that a so-called “slack” for avoiding interference with the cutting insert 1 may be formed around the bottom surface 22 of the insert seat at a boundary portion with the wall surface 23 of the insert seat. In this case, the true contour shape of the bottom surface 22 of the insert seat does not necessarily have to be a substantially parallelogram as long as it is effective in avoiding the complicated shape of the shading. The contour shape of the bottom surface 22 of the insert seat described in the present embodiment is a basic contour shape corresponding to the contour shape of the cutting insert 1. Of course, you may give.

The wall surface 23 of the insert seat has a recessed wall surface portion 24 including at least an inclined surface. As shown in FIG. 10 showing a cross-section along the line XX of FIG. 9, the inclined surface of the recessed wall surface portion 24 is in contact with the inclined surface of the first protruding side surface portion 9 a of the cutting insert 1. As it goes from the end away from the bottom surface 22 toward the bottom surface 22, it is recessed inward. That is, the recessed wall surface portion 24 is inclined from the top surface 21 a adjacent to the top surface 2 of the cutting insert 1 toward the bottom surface 22 so as to form an acute angle with the bottom surface 22. The recessed wall surface portion 24 can also be formed as a flat surface as shown in FIGS.

Here, as shown in FIG. 8, a plane in contact with the recessed wall surface portion 24 is defined as a virtual plane D. A plane in contact with the bottom surface 22 of the insert seat is defined as a virtual plane E. The virtual plane D and the virtual plane E intersect at an acute angle at the inner angle. FIG. 11 schematically shows the contact state between the cutting insert 1 and the insert seat of this embodiment. The fact that the virtual plane D and the virtual plane E intersect at an acute angle at the inner angle means that the angle α shown in FIG. 11 is smaller than 90 °. When the recessed wall surface portion 24 is formed in such a shape, there is an effect of pressing the cutting insert 1 against the bottom surface 22 side of the insert seat when a force in the direction of lifting from the insert seat is applied to the cutting insert 1 by cutting. Therefore, the clamping property of the cutting insert 1 is stabilized, and the movement of the cutting insert 1 is suppressed.

As described above, when the contour shape of the bottom surface 22 of the insert seat is a substantially parallelogram in accordance with the shape of the cutting insert 1, the wall surface 23 of the insert seat is in contact with the inclined surface of the protruding side surface portion 9a of the cutting insert 1. The concave wall surface portion 24 that comes into contact with the wall surface portion 26 that comes into contact with the main constrained side surface portion 11 of the cutting insert 1 is included. The wall surface portion 26 is a wall surface portion that is formed along the long side of the parallelogram in plan view and is located on the opposite side to the first main cutting edge 6a of the cutting insert 1 that is involved in cutting. . Therefore, the wall surface portion 26 can also be called a main constraining wall surface portion for the cutting insert 1. As shown in FIG. 8, when a plane that contacts the main constraining wall portion 26 is a virtual plane F, the virtual plane F that contacts the main confining wall portion 26 is an acute angle at an internal angle with respect to the virtual plane D that contacts the concave wall portion 24. Intersect. For this reason, coupled with the recessed wall surface portion 24 that comes into contact with the inclined surface of the protruding side surface portion 9a, rotation and lifting of the cutting insert 1 during cutting are suppressed, and the cutting insert 1 is firmly restrained by the insert seat. .

As best shown in FIG. 10, the wall surface 23 of the insert seat further has a second recessed wall surface portion 25 in the vicinity of the connection portion with respect to the bottom surface 22 of the recessed wall surface portion 24. The second recessed wall surface portion 25 forms a wall surface recessed further inward than the recessed wall surface portion 24, and when the cutting insert 1 is mounted on the insert seat of the tool body 21, the extended side surface portion 10 of the cutting insert 1. Contact is avoided. That is, the second recessed wall surface portion 25 accommodates the extending side surface portion 10 in the inside thereof, so that the recessed wall surface portion 24 can reliably come into contact with the inclined surface of the protruding side surface portion 9 a of the cutting insert 1. Moreover, when using the cutting insert 1 which made it possible to make other cutting blade 5 participate in cutting by reversing and mounting | wearing with an insert seat like this embodiment, it does not become a flank. Since the side surface portion 10 does not contact the second recessed wall surface portion 25, the extended side surface portion 10 is protected. Further, as shown in FIG. 10, if the second recessed wall surface portion 25 is recessed so as to straddle the bottom surface 22, the cutting edge 5 not involved in cutting may interfere with the bottom surface 22. Can accept the part. That is, by appropriately determining the shape of the second recessed wall surface portion 25, it is possible to reliably prevent the cutting edge 5 of the cutting insert 1 from being damaged when not in use.

1-3. Modification of Cutting Insert and Tool Body In the first embodiment described above, the inclined surface of the protruding side surface portion 9 and the inclined surface of the recessed wall surface portion 24 of the insert seat are both formed as flat surfaces. However, the surface shape can be determined as appropriate in consideration of other conditions as long as it meets the basic purpose of obtaining good clamping performance with the contact of the two.

For example, as schematically shown in FIG. 12, the inclined surface of the protruding side surface portion 9 of the cutting insert 1 may be a convex curved surface that bulges outward. The curved surface shown in the figure includes a curve that bulges outward when a cross-sectional shape obtained by cutting the cutting insert 1 perpendicularly to the upper surface 2 is considered. As shown in FIG. 12, the inclined surface of the first protruding side surface portion 9 a has a smaller inclination angle with respect to the upper surface 2 as it approaches the upper surface 2, and the crossing angle with the upper surface 2 becomes dull. Chipping is less likely to occur.

On the other hand, although not shown, when considering a cross-sectional shape obtained by cutting the cutting insert 1 in parallel with the upper surface 2, the curved surface that bulges outward may include a curve that bulges outward. However, also in this case, in light of the purpose of improving the clamping performance of the cutting insert by preferably abutting against the recessed wall surface portion 24, the condition of projecting outward from the upper surface 2 toward the lower surface 3, that is, in the present embodiment. In short, the condition of inclining outward from the upper surface 2 toward the lower surface 3 should be satisfied. Here, the inclination angle may be constant, or may increase toward the lower surface 3 as shown in FIG. In the former case, the inclined surface of the protruding side surface portion 9 of the cutting insert 1 may be a part of a conical surface, for example, and in the latter case, it may be a part of a spherical surface or a paraboloid. In any case, since the intersecting angle of the curved surface with the first main cutting edge 6a becomes duller as it approaches the first main cutting edge 6a, the long side on which the first main cutting edge 6a is formed and Chipping of obtuse corners, which are intersections with adjacent short sides, is less likely to occur.

In addition, regarding the recessed wall surface portion 24, if at least a portion that contacts the inclined surface of the protruding side surface portion 9 has a shape (concave curved surface) that follows the inclined surface (convex curved surface), the first protruding side surface portion 9 a It is possible to prevent the concave wall surface portion 24 from coming into contact with the corner portion, and to prevent problems such as chipping of the portion of the cutting insert 1 that is not involved in cutting and plastic deformation of the concave wall surface portion 24. Moreover, in this embodiment, since the cutting edge 5 is not formed in an obtuse corner, the obtuse angle corner has a high degree of freedom to make it a strong shape that does not cause chipping.

Further, as schematically shown in FIG. 13, the inclined surface of the protruding side surface portion 9 can be a concave curved surface that is recessed inward. The curved surface shown in the figure includes a curve that dents inward when a cross-sectional shape obtained by cutting the cutting insert 1 perpendicularly to the upper surface 2 is considered. As shown in FIG. 13, the inclined surface of the first projecting side surface portion 9 a has a larger inclination angle with respect to the upper surface 2 as it approaches the upper surface 2, and a crossing angle with the upper surface 2 becomes smaller. The area of the upper surface 2 can be expanded. Moreover, since the recessed wall surface part 24 is contact | abutted with the cutting insert 1 in the uppermost part, the effect which presses the cutting insert 1 becomes the maximum.

On the other hand, although not shown, the inclined surface of the protruding side surface portion 9 can also be obtained by making the cross-sectional shape cut parallel to the upper surface 2 into a curved surface that is recessed inward. When a cross-sectional shape obtained by cutting the cutting insert 1 in parallel with the upper surface 2 is considered, the curved surface recessed inward may include a curved line recessed inward. However, even in this case, the same condition as described above, that is, the condition of inclining outward from the upper surface 2 toward the lower surface 3 should be satisfied. The inclination angle may be uniform, or may decrease toward the lower surface 3 as shown in FIG. In any case, both ends in the width direction of the first projecting side surface portion 9a project outward and surely come into contact with the recessed wall surface portion 24 of the insert seat. Therefore, the rotational direction in the plane of the cutting insert 1 Can effectively suppress the movement.

In these modified examples as well, with respect to the recessed wall surface portion 24, at least a portion in contact with the inclined surface of the protruding side surface portion 9 can have a shape (convex curved surface) following the inclined surface (concave curved surface). .

In the above-described embodiment, the first projecting side surface portion 9a has a constant distance (height) to the first projecting side surface portion 9a with reference to the virtual plane B in contact with the lower surface 3 described above. However, the present invention is not limited to this, and the distance to the first protruding side surface portion 9a may be changed. In other words, the height of the contact portion of the first protruding side surface portion 9a with respect to the recessed wall surface portion 24 may be provided so as to change along the surface of the inclined surface of the protruding side surface portion 9a.

For example, the distance to the first protruding side surface portion 9a may be increased as the distance from the portion adjacent to the first main cutting edge 6a of the first cutting edge 5a involved in the cutting process increases. When the first projecting side surface portion 9a is formed in this way, the first projecting side surface portion 9a is located closer to the lower surface 3 as it is closer to the first main cutting edge 6a. Then, for example, even if chip abrasion or collision occurs with the cutting operation of the first main cutting edge 6a, the range of influence is limited to a narrow range near the obtuse corner of the upper surface 2, and the lower surface 3 The risk of damage to the first protruding side surface portion 9a and the recessed wall surface portion 24 located close to each other can be reduced. Along with this, it becomes possible to further stabilize the clamping performance of the cutting insert 1.

On the contrary, for example, the distance to the first protruding side surface portion 9a may be made smaller as the distance from the portion adjacent to the first main cutting edge 6a increases. When the first projecting side surface portion 9a is formed in this way, the first projecting side surface portion 9a is positioned so as to approach the lower surface 3 as the distance from the portion adjacent to the first main cutting edge 6a increases. . Thus, when the 1st protrusion side surface part 9a is formed, the movement which the diagonal position of the cutting insert 1 tries to float up by the cutting resistance which the 1st corner cutting edge 8a receives, for example is suppressed effectively. be able to.

Further, as schematically shown in FIG. 14, not only the inclined surface of the protruding side surface portion 9 but also the recessed wall surface portion 24 of the insert seat of the tool body 21 can be formed in a curved surface shape. As shown in FIG. 14, when the concave wall surface portion 24 is a convex curved surface that bulges outward, it is preferable to assume that elastic deformation occurs in both sides when the protruding side surface portion 9 and the concave wall surface portion 24 abut. By defining the conditions of both materials and the like so that a certain amount of elastic deformation occurs, the contact area can be increased, and the cutting insert 1 can be pressed down more reliably. At the same time, it is possible to prevent problems such as plastic deformation of the recessed wall surface portion 24 as compared with the case where the contact is performed by corner or line contact.

On the other hand, although not shown, the concave wall surface portion 24 can be formed into a concave curved surface that is recessed inward in accordance with the convex curved surface of the protruding side surface portion 9 that protrudes outward. When the recessed wall surface portion 24 is formed as described above, the area of the contact surface is further increased, and the cutting insert 1 can be pressed near the upper end of the recessed wall surface portion 24. Therefore, the effect of suppressing the floating of the cutting insert 1 can be suppressed. Maximum.

The concave wall surface portion 24 can be formed such that the contact position with respect to the cutting insert 1 changes the distance (height) from the bottom surface 22 of the insert seat. When the recessed wall surface portion 24 is formed in this way, it is possible to more reliably cope with the change in the height of the first protruding side surface portion 9a of the cutting insert 1 as described above.

2. Other Embodiments The cutting insert 1 in the second embodiment is shown in FIGS. 15 to 18. Here, about each part which can be comprised the same as or similar to 1st Embodiment, the same code | symbol is attached | subjected to a corresponding location and description is abbreviate | omitted. The cutting insert 1 and the cutting tool 20 in this embodiment are the cutting insert 1 and the cutting tool 20 for a high-feed cutter. Therefore, the crossing angle between the main cutting edge 6 and the auxiliary cutting edge 7 is a large obtuse angle. In this embodiment, the crossing angle between the main cutting edge 6 and the auxiliary cutting edge 7 can be about 160 ° in plan view. The tool body 21 of the cutting tool 20 can be the same as the tool body 21 in the first embodiment described above. That is, the tool body 21 can have a shape that can correspond to either of the two types of cutting inserts 1 of the first and second embodiments. However, it is needless to say that the present invention is not limited to this, and a dedicated tool body 21 may be used in each embodiment.

The cutting insert 1 is made of cemented carbide, cermet, ceramics and cubic boron nitride, or a material coated with a hard material surface, or a sintered material such as diamond. It is a body material. The cutting insert 1 may be entirely made of such a hard material.

These cutting inserts are applicable to various cutting tools, and can be used for cutting steel materials by attaching the cutting tools to machine tools. Any cutting insert having a main cutting edge and a sub cutting edge can be applied to most cutting tools.

The cutting insert, tool body, and cutting tool of the present invention are not limited to the above-described embodiments, and various modifications and additions can be made without departing from the gist of the present invention. For example, the present invention can be applied to a triangular, rectangular, rhombus, pentagonal, or hexagonal or more polygonal cutting insert in plan view. That is, the cutting insert according to the present invention does not have to have the parallelogram as described above in a plan view. Further, it may not be possible to selectively use a plurality of cutting edges by rotation or reversal. That is, it has at least one cutting edge and protrudes outward from the cutting insert to a portion where the movement of the cutting insert that can be caused by the force applied to the cutting insert when the cutting edge is involved in cutting is effectively suppressed. What is necessary is just the structure which has the protrusion side surface part contact | abutted with the wall surface part of an insert seat. Further, the cutting insert and the protrusion of the insert seat may not have the shape of the inclined surface. However, from the viewpoint of effectively generating the component force that supports the cutting resistance by mutual contact, as described above. Adoption of an inclined surface is preferable.

In addition, the tool body to which the cutting insert of the present invention is to be attached has a concave wall surface portion having a relatively simple shape as described above, so that the ease of manufacturing the tool body and the required accuracy can be achieved. From the viewpoint of obtaining. In addition, it is preferable to provide a recessed wall surface portion having a shape that follows the protruding side surface portion of the cutting insert in order to increase the contact area with the protruding side surface portion. However, the tool body to be mounted according to the present invention is not limited to the above-described embodiment. In other words, any shape may be used as long as it has a wall surface portion that abuts the protruding side surface portion of the cutting insert and preferably clamps the cutting insert. For example, the tool body projects from a part of the wall surface formed perpendicular to the imaginary plane E into a space where the insert seat is defined, and a shelf-like wall surface portion that abuts against the protruding side surface portion of the cutting insert. It may have. The present invention also resides in a cutting tool in which a cutting insert is mounted on such a tool body.

Claims

A cutting insert (1) having first and second end faces (2, 3) and a side face (4) connecting the end faces (2, 3),
At least one cutting edge (5, 5a) is formed on the intersecting ridge line between the first end surface (2) and the side surface (4),
Said side surface (4) comprises protruding side surface portions (9, 9a),
The projecting side surface portions (9, 9a) project outward from the first end surface (2) toward the second end surface (3), and face the first end surface (2). A cutting insert that protrudes outward as it is separated from the cutting edge (5, 5a) when viewed from the direction.
The protruding side surface portion (9, 9a) is provided at a portion of the side surface (4) that is away from the cutting edge (5, 5a) and where the cutting edge (5, 5a) is not formed. The cutting insert according to claim 1, wherein the cutting insert is characterized.
Cutting insert according to claim 1 or 2, characterized in that at least one cutting edge (5) is also formed on the intersecting ridgeline between the second end face (3) and the side face (4).
The protruding side surface portion (9) comprises an inclined surface;
When the plane in contact with the inclined surface is the first virtual plane (A) and the plane in contact with the second end surface (3) is the second virtual plane (B), the first virtual plane (A) The cutting insert according to any one of claims 1 to 3, wherein the second virtual plane (B) intersects with an acute angle at an inner angle.
When viewed from the direction facing the first end face (2), the cutting insert (1) has a substantially parallelogram outline shape;
The cutting edges (5, 5a) include a main cutting edge (6, 6a) and a sub cutting edge (7, 7a) formed on at least one pair of two adjacent sides among the four sides of the parallelogram. )
The protruding side surface portion (9, 9a) is included in a portion (12) of the side surface (4) connected to a side opposite to the side including the auxiliary cutting edge (7a),
The protruding side surface portion (9) is an inclined surface, and a plane contacting the inclined surface is a first imaginary plane (A), and the protruding side surface portion (9) is connected to the side opposite to the side including the main cutting edge (6, 6a). Assuming that the plane in contact with the portion (11) of the side surface (4) is the third virtual plane (C), the first virtual plane (A) and the third virtual plane (C) are acute angles with internal angles. The cutting insert according to any one of claims 1 to 4, wherein the cutting insert intersects.
The cutting insert according to any one of claims 1 to 5, wherein the protruding side surface portion (9, 9a) is a flat surface.
The cutting insert according to any one of claims 1 to 5, wherein the protruding side surface portion (9, 9a) is a curved surface that bulges outward.
The cutting insert according to any one of claims 1 to 5, wherein the protruding side surface portion (9, 9a) is a curved surface that is recessed inward.
A plane in contact with the second end surface (3) is defined as a second virtual plane (B), and the distance to the protruding side surface portion (9, 9a) is measured with the second virtual plane (B) as a reference. 9. The cutting insert according to claim 1, further comprising a portion in which the distance changes with distance from a part (6, 6 a) of the cutting edge (5, 5 a).
The side surface (4) is formed on the second end surface (3) side continuously to the protruding side surface portion (9, 9a) and extends further outward than the protruding side surface portion (9, 9a). Cutting insert according to any of claims 1 to 9, characterized in that it has a part (10).
A tool body (21) for detachably mounting the cutting insert (1),
Having at least one insert seat provided with a bottom surface (22), a wall surface (23) and an open surface;
The wall surface (23) is formed with a recessed wall surface portion (24) in contact with the mounted cutting insert (1),
The recessed wall surface portion (24) has an inclination that indents inwardly from the end away from the bottom surface (22) toward the bottom surface (22), and from a direction facing the bottom surface (22). A tool body characterized in that it indents inward as it leaves the open surface.
A tool body (21) for detachably mounting the cutting insert (1) according to any one of claims 1 to 10,
If the plane in contact with the recessed wall surface portion (24) is the fourth virtual plane (D) and the plane in contact with the bottom surface (22) is the fifth virtual plane (E), the fourth virtual plane (D) The tool body according to claim 11, wherein the fifth virtual plane (E) intersects with an acute angle at an inner angle.
When viewed from the direction facing the bottom surface (22), the bottom surface (22) has a substantially parallelogram outline,
A plane in contact with the recessed wall surface portion (24) is a fourth virtual plane (D),
Of the four sides of the parallelogram, a plane in contact with the portion (26) of the wall surface (23) included in the side adjacent to the side connected to the recessed wall surface portion (24) is a sixth virtual plane ( F)
The tool body according to claim 11 or 12, wherein the fourth virtual plane (D) and the sixth virtual plane (F) intersect at an acute angle at an internal angle.
The tool body according to any one of claims 11 to 13, wherein the concave wall surface portion (24) is a flat surface.
The tool body according to any one of claims 11 to 13, wherein the concave wall surface portion (24) is a curved surface.
A second recessed wall surface portion (25) is formed on the bottom surface (22) side of the recessed wall surface portion (24) so as to continue inward from the recessed wall surface portion (24). The tool body according to any one of claims 11 to 15.
A cutting tool comprising the cutting insert (1) according to any one of claims 1 to 10.
17. A tool body (21) according to any one of claims 11 to 16, wherein the cutting insert (1) has the protruding side surface portion (9, 9a) in the recessed wall surface portion. The cutting tool according to claim 17, wherein the cutting tool is mounted in a state of being in contact with (24).