JP2016187836A - Cutting insert and cutting edge replaceable cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting insert which is high in fixing performance to an insert attachment seat while allowing narrow-width grooving.SOLUTION: This cutting insert 1 comprises an insert main body 6, a plurality of salient parts 7, and an attachment hole 5. Each salient part 7 has a salient part upper face 11 formed at a body part upper face 8 side, a salient part lower face 12 formed at a body part lower face 9 side, two salient part side faces 13 continuous to a body part side face 10 which corresponds to the respective salient part side faces, and a salient part side end face 14 which extends between the two salient part side faces. A corner R face 15 is formed between the salient part upper face 11 and the salient part side end face 14. A cutting edge 16 has a corner which is formed along an edge of the corner R face 15, and is formed along a cross ridge line part between the salient part upper face 11, the corner R face 15 and the salient part side end face 14, and the salient part side face 13 so that the salient part side faces 13 become rake faces. The body part lower face 9 is located in a position approximate to the body part upper face 8 side rather than the salient part lower face 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cutting insert and a cutting edge exchangeable cutting tool to which the cutting insert is attached. More specifically, the present invention relates to a vertical type cutting insert used for grooving and a side cutter to which the cutting insert is detachably mounted.

  2. Description of the Related Art Conventionally, as a cutting tool for performing grooving, there is a blade edge exchange type side cutter. An example of such a side cutter is disclosed in Patent Document 1. The cutting insert used for the side cutter described in Patent Document 1 is composed of an upper surface having a substantially polygonal outer shape, a lower surface having an outer shape that substantially matches the upper surface, and a side surface that connects the upper surface and the lower surface. Vertical type. The upper surface and the lower surface have three projecting portions formed so as to project outward from the tops or side surfaces of the substantially polygonal outline in plan view. A corner R surface is formed on the intersecting ridge line between the upper surface and the end surface of the projecting portion, and the length of the intersecting ridge line on which the corner R surface is formed is a cutting insert body portion excluding the projecting portion in plan view. Shorter than the diameter of the inscribed circle.

  With such a configuration, in the cutting insert described in Patent Document 1, the length of the intersecting ridge line portion where the corner R surface is formed can be remarkably shortened without reducing the size of the entire cutting insert. Therefore, the rake angle in the negative radial direction can be reduced without reducing the strength of the cutting insert. Furthermore, since there is no restriction on the radius of curvature of the corner provided in the intersecting ridge line portion, there is an advantage that the radius of curvature of the corner corresponding to the corner R to be formed in the groove can be freely set.

International Publication No. 2012/173255 Pamphlet

  By the way, in the groove processing, it is necessary to form grooves having various sizes according to the purpose. In particular, in recent years, there is a demand for a tool capable of forming a very narrow groove having a groove width of 6 mm or less.

  Here, in order to apply the cutting insert described in Patent Document 1 to a grooving process (specifically, a groove width of 6 mm or less) having a contour shape as it is and having a narrower groove width, according to the groove width. It is necessary to reduce the thickness of the cutting insert. Since the cutting insert of patent document 1 is installed vertically, when it is mounted on the side cutter, the length of the cutting edge located on the outer peripheral surface of the side cutter (that is, the cutting edge that cuts the bottom of the groove) is the cutting insert. The thickness is almost the same. Therefore, in order to ensure a constant cutting edge length, a constant thickness must be maintained for the cutting insert. That is, when considering the case where grooves are formed by mounting cutting inserts on both end faces of the side cutter in a zigzag manner, the cutting edge length needs to be at least larger than half of the groove width to be processed. Therefore, the cutting insert itself also requires at least a length greater than half the groove width to be machined, ie, a thickness greater than half the side cutter width. Therefore, the thickness of the portion (insert mounting seat) where the cutting insert is mounted in the side cutter is thinner than half of the groove width to be processed. For example, when the groove width is 6 mm, the insert mounting seat of the side cutter is less than 3 mm even at the maximum thickness. Thus, when the thickness of the insert mounting seat becomes extremely thin, when the cutting insert is mounted on the insert mounting seat with the mounting screw, the “hanging portion” of the mounting screw in the insert mounting seat (ie, screw hole length) Becomes too short, and the fixing force of the cutting insert becomes remarkably weak. Further, since the tip of the mounting screw is not allowed to protrude from the screw hole, the “hanging portion” of the mounting screw is further shorter than the screw hole length, so that the fixing force of the cutting insert is further weakened. For this reason, the cutting insert is displaced during processing, which may cause a chipping of the cutting edge. Moreover, since the thickness of the insert mounting seat is too thin, there arises a problem that the rigidity of the side cutter itself is lowered. The reduction in rigidity of the tool itself is a major cause of chattering.

  The present invention has been made in view of the above problems, and a cutting insert having a high fixability to an insert mounting seat and a cutting tool equipped with the cutting insert while being capable of performing narrow groove processing. The purpose is to provide.

  The present invention includes a body part upper surface 8, a body part lower surface 9 disposed to face the body part upper surface 8, and a body part side surface 13 extending between the body part upper surface 8 and the body part lower surface 9. An axis A passing through the body upper surface 8 and the body lower surface 9 is defined, and the insert body 6 and the outside of the insert body 6 in the direction perpendicular to the axis A each having a cutting edge 16. A plurality of projecting portions 7 provided integrally with the insert body portion 6 at a position, and a mounting hole 5 penetrating the body portion upper surface 8 and the body portion lower surface 9. A protrusion upper surface 11 disposed on the side of the body 8, a protrusion lower surface 12 disposed on the side of the body lower surface 9, two protrusion side surfaces 13 each connected to the corresponding body side surface 10, and extending between them. A projecting portion side end surface 14, and the projecting portion 7 includes a projecting portion upper surface 11 and a projecting portion side end surface 14. The corner R surface 15 is formed, and the cutting edge 16 has a corner formed along the edge of the corner R surface 15, and the projecting portion upper surface 11 and the corner R so that the projecting portion side surface 13 becomes a rake face. Cutting is formed along the intersecting ridge line portion of the surface 15 and the protruding portion side end surface 14 and the protruding portion side surface 13, and the body portion lower surface 9 is located closer to the body portion upper surface 8 side than the protruding portion lower surface 12. Insert 1.

  Furthermore, the present invention is a cutting tool 20 comprising a tool body 21 having at least one insert mounting seat 26 and at least one cutting insert mounted on the insert mounting seat 26, wherein the cutting insert is described above. It is a cutting insert 1.

  According to the present invention, since the insert body portion is configured to be thinner than the protruding portion, it is possible to ensure a long “hanging portion” of the mounting screw in the tool body. Therefore, even in the case of a cutting insert thinner than the cutting insert of Patent Document 1, it is possible to greatly suppress the deterioration of the cutting insert fixability with respect to the tool body. Therefore, chatter, breakage of the cutting edge, and the like due to a decrease in cutting insert fixing property can be significantly reduced.

The upper surface side perspective view of one Embodiment of the cutting insert of this invention is shown. FIG. 2 shows a top view of the cutting insert of FIG. 1. The lower surface side perspective view of the cutting insert of FIG. 1 is shown. The IV-IV sectional view in FIG. 2 is shown. The perspective view of one Embodiment of the blade-tip-exchange-type cutting tool equipped with the cutting insert of FIG. 1 is shown. FIG. 6 shows a perspective view of the tool body of FIG. 5. FIG. 6 shows an enlarged perspective view near the insert mounting seat of the tool body of FIG. 5. The perspective view of the state in which the cutting insert was mounted | worn with the insert mounting seat of FIG. 7 is shown.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 to 4, the cutting insert 1 of the present embodiment includes an upper surface 2 and a lower surface 3 that are opposed to or opposite to each other, and a peripheral side surface 4 that extends between them. With. The upper surface 2 and the lower surface 3 are substantially parallel. The cutting insert 1 has an axis A that passes through the upper surface 2 and the lower surface 3, and is formed around the axis A in a rotationally symmetrical manner by 120 °. A mounting hole 5 having a central axis A that coincides with the axis A is formed so as to penetrate the upper surface 1 and the lower surface 2.

  The cutting insert 1 includes an insert body portion 6 and three projecting portions 7 provided integrally with the insert body portion 6. The insert body part 6 includes a body part upper surface 8, a body part lower surface 9, and three body part side surfaces 10 extending therebetween. The body part upper surface 8 and the body part lower surface 9 face each other and are positioned on the opposite side with respect to each other, and are substantially parallel to each other. One protrusion 7 is disposed between any two side surfaces of the three body side surfaces 10. In addition, the part remove | excluding the three protrusion parts 7 from the cutting insert 1 can be defined as the insert body part 6. FIG.

  The insert body portion 6 is designed so as to substantially have a 120 ° rotationally symmetric shape around the axis A, that is, the central axis of the mounting hole 5. Similarly, three protrusions 7 are arranged at rotationally symmetrical positions around the axis A. Thus, the cutting insert 1 is formed so as to have a shape that is substantially rotationally symmetrical about the axis A by 120 °.

  When the body part upper surface 8 of the insert body part 6 is regarded as a substantially triangular shape or a triangular shape, the three projecting parts 7 are positioned so as to be positioned at the top of the triangle of the body part upper surface 8. The protruding portion 7 is provided at an outer position of the insert body portion 6 in the direction orthogonal to the axis A. That is, the protruding portion 7 is provided so as to protrude or extend outward from the insert body portion 6.

  The three protrusions 7 have substantially the same configuration. Therefore, unless otherwise specified, any one protrusion 7 will be described below.

  The protruding portion 7 is provided at an outer position of the insert body portion 6 in the direction orthogonal to the axis A. The protrusion 7 has a substantially rectangular parallelepiped shape. Specifically, the protruding portion 7 is connected to the protruding portion upper surface 11 connected to the body portion upper surface 8, the protruding portion lower surface 12 protruding a certain distance from the body portion lower surface 9, and the corresponding body portion side surface 2 2. It has the one protrusion part side surface 13, and the protrusion part side end surface 14 extended between these. Further, a corner R surface (corner curved surface) 15 extending between the protrusion upper surface 11 and the protrusion-side end surface 14 is formed on the protrusion 7 from one side to the other of the two protrusion side surfaces 13. ing.

  In the present embodiment, the upper surface 11 of the protruding portion is formed on the same plane as the upper surface 8 of the body portion. However, as is apparent from the sectional view of FIG. One step protrudes in a direction parallel to the axis A rather than 9. That is, the upper surface 11 of the protruding portion is substantially flush with the upper surface 8 of the body portion, while the lower surface 12 of the protruding portion is formed closer to the upper surface 11 side of the protruding portion than the lower surface 9 of the body portion. In other words, it can be said that the insert body portion 6 is formed so that the lower surface side is thinner than the protruding portion 7. Moreover, in this embodiment, although the protrusion part 7 is formed so that it may have the same thickness as a whole, it is not limited to this, The inner side of the insert body part 6 from the protrusion part side end surface 14 It may be formed so that the thickness gradually becomes thinner as it is separated to the side, and finally becomes the same as the thickness of the insert body portion 6. Or you may form so that thickness may become thin gradually, not decreasing gradually. Here, “substantially” the same plane means that the protrusion upper surface 11 is slightly angled with respect to the body upper surface 9 so that the inner angle is less than 180 ° in the side view of the cutting insert 1. This is because they are connected. Thus, the structure which the protrusion part upper surface 11 and the body part upper surface 9 connect with a fixed angle may be sufficient, and you may exist on the same plane completely.

  As shown in FIG. 2, regarding the respective end portions (corners) of the corner R surface 15, the maximum dimension sandwiching both end portions is the length L of the corner R surface 15. The length L of the corner R surface 15 is set within a predetermined range. Further, as shown in FIG. 2, an inscribed circle IC can be defined on the body upper surface 8 of the insert body 6. The length L of the corner R surface 15 is shorter than the diameter of the inscribed circle IC. Therefore, the length of the corner R surface 15 is sufficiently shorter than the size of the insert body portion 6. Further, the length L of the corner R surface 15 is preferably equal to or greater than the thickness of the protruding portion 7. By doing in this way, it is possible to raise the intensity | strength of the protrusion part 7 suitably, aiming at size reduction of the protrusion part 7. FIG.

  Two cutting edges 16 are formed on one protrusion 7. The cutting edge 16 has a corner formed along the edge of the corner R surface 15, and the protrusion upper surface 11, the corner R surface 15, and the protrusion side end surface 14 so that the protrusion side surface 13 becomes a rake face. It is formed along the intersection ridge line part of each and the protrusion part side surface 13. As shown in FIG. Note that the curvature or radius of curvature of the corner can be appropriately changed according to the size of the corner curved surface of the groove desired to be formed in the work material. One cutting edge 16 in one protrusion 7 is a right-handed cutting edge, and the other cutting edge 16 is a left-handed cutting edge. Therefore, in the cutting insert 1, the three cutting edges 16 can be used as a right-handed cutting edge, and another three cutting edges 16 can be used as a left-handed cutting edge. Thus, the cutting insert 1 is an indexable cutting insert. The right-handed cutting edge means that the protrusion upper surface 11 is the right side when the cutting insert 1 is viewed from the direction of the blade edge, that is, the direction facing the protrusion side surface 13 and the protrusion side end face 14 is viewed upward. The left-handed cutting edge is a cutting edge on the left side when the cutting insert 1 is viewed from the direction of the cutting edge. Moreover, the protrusion part upper surface 11, the protrusion part side end surface 14, and the corner R surface 15 become a flank.

  Moreover, in this embodiment, the recessed part 17 is formed in the intersection ridgeline part of the body part upper surface 8 and the body part side surface 10 along the full length. That is, the thickness of the insert body portion 6 is thinner than the other portions along the intersecting ridge line portion between the body portion upper surface 8 and the body portion side surface 10. In the cutting insert 1 of the present embodiment, the concave portion 17 is formed in a stepped shape as shown in FIG. 4, but is not limited to this, and other parts such as a chamfer cut obliquely. It may be a shape.

  The vicinity of the cutting edge of the cutting insert 1 can be made from a hard material such as cemented carbide, coated cemented carbide, cermet, ceramic, or an ultra-high pressure sintered body containing diamond or cubic boron nitride.

  The cutting insert 1 having such a configuration is detachably mounted on a tool body 21 of a cutting tool 20 as shown in FIG.

  As shown in FIG. 6, the tool body 21 is basically composed of two end surfaces 22, an outer peripheral surface 23 extending between the two end surfaces 22, and a bore hole 24 penetrating the center of the two end surfaces 22. It is structured. The two end faces 22 face each other, that is, are located on the opposite sides of each other, and each has a substantially circular shape. A chip pocket 25 and a plurality of insert mounting seats 26 are formed on the outer peripheral surface 23. The chip pocket 25 is provided so as to suitably discharge chips. The insert mounting seat 26 is provided on the outer peripheral surface 23 on the rear side in the tool rotation direction K adjacent to the corresponding chip pocket 25. The insert mounting seats 26 are alternately formed in a staggered pattern on each of the two end faces 22 of the tool body 21, and the plurality of cutting inserts 1 are alternately mounted in a staggered pattern on each of the two end faces 22. At this time, the cutting insert 1 is vertically mounted on the insert mounting seat 26 so that the corner of the usable cutting edge protrudes outward. When the cutting insert 1 is attached, the protruding portion side end surface 14 of the protruding portion 7 of the cutting insert 1 slightly protrudes from the outer peripheral surface 23 of the tool body 21, and the corner R surface 15 of the protruding portion 7 is positioned outside. ing. Further, in this embodiment, the insert mounting seat 26 is configured so that the cutting insert 1 is mounted with an axial rake of −3 ° and a radial rake of −7 °. However, the axial rake and the radial rake are large. This is not limited to this. By setting the axial rake and the radial rake in this way, the cutting insert 1 is provided with a positive clearance angle with respect to the tool radial direction and the tool rotation axis direction.

  As shown in the enlarged view of FIG. 7, the insert mounting seat 26 includes a bottom surface 27 and a side surface 28 that is substantially perpendicular to the bottom surface 27. The bottom surface 27 includes a first bottom surface 27a in which a screw hole 30 for screwing a mounting screw 29 for fixing the cutting insert 1 is formed, and a position lower than the first bottom surface 27a (that is, from the first bottom surface 27a. And a second bottom surface 27b formed at a recessed position). The second bottom surface 27 b is provided so as to correspond to the positional relationship of the protruding portion 7 of the cutting insert 1. The side surface 28 includes a first side surface 28a connected to the first bottom surface 27a and a second side surface 28b connected to the second bottom surface 27b.

  As shown in FIG. 8, the cutting insert 1 is fixed to the insert mounting seat 26. That is, the protruding portion 7 of the cutting insert 1 is disposed so as to correspond to the second bottom surface 27 b of the insert mounting seat 26. At this time, the body side surface 10 of the cutting insert 1 and the first side surface 28a of the insert mounting seat 26 are in contact, but the protrusion 7 is not in contact with the second side surface 28b. That is, the second side surface 28 b is formed so as not to contact the protruding portion side surface 13 and the protruding portion side end surface 14. This prevents the cutting edge 6 that has not been used from being damaged by coming into contact with the insert mounting seat 26. Further, the step side surface 18 (see FIGS. 3 and 4) of the protrusion 7 of the cutting insert 1 does not contact the step side surface 31 of the insert mounting seat 26. In other words, the first bottom surface 27 a is formed inside the cutting insert 1 with respect to the outline shape of the projecting portion lower surface 12 of the cutting insert 1 in plan view. As a result, the cutting insert 1 comes into contact with only the two first side surfaces 28a in the tool radial direction, that is, is supported only by the two first side surfaces 28a. Even if some distortion or the like occurs due to manufacturing errors or the like, the insert mounting seat 26 is securely fixed without rattling. In the present embodiment, the body portion lower surface 9 is in contact with the first bottom surface 27a, but the protruding portion lower surface 12 is not in contact with the second bottom surface 27b. That is, the difference in the height direction between the body lower surface 9 and the protrusion lower surface 12 is configured to be smaller than the height difference between the first bottom surface 27a and the second bottom surface 27b. . As a result, the cutting insert 1 comes into contact with only the first bottom surface 27a in the tool axis direction, that is, is supported only by the first bottom surface 27a. Therefore, a manufacturing error is added to the cutting insert 1 or the insert mounting seat 26. Even if some distortion or the like is generated due to, etc., it is securely fixed without rattling. As described above, in the present embodiment, the structure is supported only by the body lower surface 9, but conversely, a structure supported only by the protrusion lower surface 12 is also possible (in this case, the protrusion lower surface 12 is the second bottom surface). 27b, but the body lower surface 9 is not in contact with the first bottom surface 27a). That is, the fixing property of the cutting insert 1 can be improved by supporting one of the body portion lower surface 9 and the protruding portion lower surface 12. However, the present invention does not exclude the form in which both the body bottom surface 9 and the first bottom surface 27 a are in contact with the insert mounting seat 26.

  Operations and effects of the cutting insert 1 and the cutting tool 20 described above will be described.

  In the present invention, the body lower surface 9 is formed at a position closer to the body upper surface 8 side than the protrusion lower surface 12, so that the “hanging portion” of the mounting screw 29 in the tool body 21 can be made longer. It is. That is, since only the insert body portion 6 is thinly formed from the body lower surface 9 side in the cutting insert 1, the thickness corresponding to the first bottom surface 27 a of the insert mounting seat 26 of the tool body 21 is reduced by the thinned portion. Can be bigger. Therefore, since the screw hole 27 can be deepened by the thickness of the portion corresponding to the first bottom surface 27a, the “hanging portion” of the mounting screw 29 can be made longer. As a result, even if the entire thickness of the cutting insert is reduced in order to perform grooving with a very narrow width, a large “hanging portion” of the mounting screw 29 can be ensured. It is possible to obtain an effect that the decrease in the temperature is suppressed. At this time, since it is not necessary to reduce the thickness of the protruding portion 7 for the purpose of improving the fixing property of the cutting insert 1, the cut formed on the intersecting ridge line between the protruding portion side surface 13 and the protruding portion side end surface 14. The blade 16 has a required length. Therefore, the cutting edge length required for mounting the cutting inserts 1 on both sides of the tool body 21 in a zigzag manner and performing grooving, that is, a length larger than at least half of the groove width to be machined (tool body) (Thickness greater than half the thickness of 21) remains maintained.

  Further, since the thick first bottom surface 27a is connected to a part of the side surface 28, there is an effect that the rigidity of the entire insert mounting seat 26 is improved. That is, the thick first bottom surface 27a is not provided independently, but is connected to a part of the side surface 28, so that the entire bottom surface 28 is remarkably strong against distortion. It is. In particular, the rigidity around the screw hole 30 that is weak in strength can be greatly improved. Therefore, since the effect of suppressing the decrease in seating stability of the cutting insert 1 and the occurrence of chatter due to the distortion of the tool body 21 itself due to the low rigidity can be obtained, the accuracy of the groove to be formed is improved. As described above, the present invention exerts a particularly great effect in a side cutter that uses a vertically installed cutting insert having an extremely thin insert mounting seat.

  Moreover, in the cutting insert 1, although the body part upper surface 8 and the protrusion part upper surface 11 are substantially on the same plane, it is not limited to this, The body part upper surface 8 protrudes in the axis A direction. It may be formed so as to be lower than the part upper surface 11 (that is, a step is formed between the body part upper surface 8 and the protruding part upper surface 11). However, if there is such a step, the “hanging portion” of the mounting screw 29 becomes smaller by the step, or the insert body portion 6 becomes thinner by the step. Therefore, in order to maximize the thickness of the “hanging portion” of the mounting screw 29 and the insert body portion 6, it is preferable that the body portion upper surface 8 and the protruding portion upper surface 11 are connected without a step.

  Furthermore, in the insert body part 6, it is preferable to provide the recessed part 17 recessed in the thickness direction along the full length in the intersection ridgeline part of the body part upper surface 8 and the body part side surface 10. This is because it is possible to greatly suppress the phenomenon that chips generated by cutting work are caught in the gap between the body side surface 10 and the side processed surface of the work material. The reason is as follows. In the cutting process using the thin cutting insert 1 as in the present embodiment, chips having a small size are generated as compared with the cutting process using the cutting insert of Patent Document 1. On the other hand, as described above, the cutting insert 1 is arranged with an axial rake and a radial rake in order to ensure a clearance angle. That is, the cutting insert 1 is disposed in a positional relationship that is inclined at a constant angle with respect to the end surface 22 and the outer peripheral surface 23 of the tool body 21. Therefore, between the cross ridge line part of the body part upper surface 8 and the body part side surface 10 that is located in front of the tool rotation direction K of the working cutting edge 16, and the side machining surface of the work material, Narrow “wedge-shaped” gaps inevitably occur. Since the wedge-shaped gap is narrow as described above, the possibility that the wedge-shaped gap enters the chip is small. However, small chips generated by the cutting insert 1 of the present embodiment may enter the gap and be bitten by the narrowest part of the wedge shape. As described above, when chips are bitten between the cutting insert and the work material, the surface of the work material may be damaged by the chips. On the other hand, when the recessed part 17 is provided in the intersection ridgeline part of the body part upper surface 8 and the body part side surface 10, the space between the intersection ridgeline part and the side part machining surface of the work material is widened, and the wedge shape Even the narrowest part is large enough not to bite chips. That is, by increasing the gap between the cutting insert 1 and the work material, even if chips enter the gap, they are configured to be easily released to the outside without being bitten. Thus, since the biting of small chips can be suppressed by providing the concave portion 17, the surface roughness of the surface of the work material is improved.

  Although the present invention has been described with a certain degree of specificity in the above-described embodiments and modifications thereof, the present invention is not limited to the above-described embodiments. It should be understood that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as set forth in the claims. That is, the present invention includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims.

DESCRIPTION OF SYMBOLS 1 Cutting insert 2 Upper surface 3 Lower surface 4 Peripheral side surface 5 Mounting hole 6 Insert body part 7 Projection part 8 Body part upper surface 9 Body part lower surface 10 Body part side surface 11 Projection part upper surface 12 Projection part lower surface 13 Projection part side surface 14 Projection part side end surface 15 Corner R surface (Corner curved surface)
16 Cutting edge 17 Recess 18 Stepped side surface 20 Projection tool 21 Tool body 22 End surface 23 Outer surface 24 Bore hole 25 Chip pocket 26 Insert mounting seat 27a First bottom surface 27b Second bottom surface 28a First wall surface 28b Second wall surface 29 Mounting screw 30 Screw hole 31 Step side of insert mounting seat

Claims (8)

An insert body part (6) comprising a body part upper surface (8), a body part lower surface (9) disposed opposite to the body part upper surface (8), the body part upper surface (8) and the body An insert body comprising a body side surface (13) extending between the body lower surface (9) and an axis (A) passing through the body upper surface (8) and the body lower surface (9) Part (6),
A plurality of protrusions (7), each having a cutting edge (16), each at an outer position of the insert body part (6) in a direction perpendicular to the axis (A). A plurality of protrusions (7) provided integrally with (6);
A mounting hole (5) penetrating the body part upper surface (8) and the body part lower surface (9);
With
The protrusion (7) includes a protrusion upper surface (11) disposed on the body upper surface (8) side, and a protrusion lower surface (12) disposed on the body lower surface (9) side. It has two protrusion side surfaces (13) connected to the corresponding body side surface (10), and a protrusion side end surface (14) extending therebetween, and the protrusion (7) includes the protrusion A corner R surface (15) extending between the top surface (11) and the protruding portion side end surface (14) is formed;
The cutting edge (16) has a corner formed along an edge of the corner R surface (15), and the protrusion upper surface (11) so that the protrusion side surface (13) is a rake face. ), The corner R surface (15) and the projecting portion side end surface (14), and the intersecting ridge line portion of the projecting portion side surface (13),
The body part lower surface (9) is located closer to the body part upper surface (8) side than the protrusion lower surface (12).
Cutting insert (1).   The cutting insert (1) according to claim 1, wherein the upper surface (8) of the body part and the upper surface (11) of the protruding part are connected without a step.   The cutting insert (1) according to claim 1 or 2, wherein a concave portion (17) is formed in an intersecting ridge line portion between the upper surface (8) of the body part and the side surface (10) of the body part. .   The protrusion (7) is formed so as to be positioned at the top of the polygon when the body upper surface (8) of the insert body (6) is regarded as a polygon. The cutting insert (1) according to any one of claims 1 to 3.   The cutting insert (1) according to claim 4, wherein the upper surface (8) of the body part has a substantially triangular shape. A cutting tool (20) comprising a tool body (21) having at least one insert mounting seat (26) and at least one cutting insert attached to the insert mounting seat (26),
The cutting tool (20), wherein the cutting insert is the cutting insert (1) according to any one of claims 1 to 5.   The insert mounting seat (26) is in contact only with the body side surface (10) of the cutting insert (1) and either the body lower surface (9) or the protrusion lower surface (12). The cutting tool (20) according to claim 6, characterized by: The insert mounting seat (26) includes a bottom surface (27) and a side surface (28) substantially perpendicular to the bottom surface (27),
The bottom surface (27) is formed in a first bottom surface (27a) in which a screw hole (30) for fixing the cutting insert (1) is formed, and in a position recessed from the first bottom surface (27a). A second bottom surface (27b), and the second bottom surface (27b) is provided so as to correspond to the position of the protrusion (7) of the cutting insert (1),
The side surface (28) includes a first side surface (28a) connected to the first bottom surface (27a) and a second side surface (28b) connected to the second bottom surface (27b). ing,
The cutting tool (20) according to claim 6 or 7, characterized in that