Cutting inserts and indexable rotary cutting tools

Abstract

This cutting insert (1) comprises a rake face (2), a seating face (3) that faces the rake face (2), a flank face (4) that connects the rake face (2) and the seating face (3), and a cutting edge (5) that is formed at the intersecting ridgeline between the rake face (2) and the flank face (4), wherein: the cutting edge (5) is configured from a straight-line main cutting edge (5b), a corner edge (5a), and a wiper edge (5c), in said order; a recess (6) is provided to the end of the main cutting edge (5b) that is opposite of the end connecting to the corner edge (5a); the wiper edge (5c) is formed in an arced shape and is connected by a tangent line to the corner edge (5a); and, where an extension line of the main cutting edge (5b) is L1, a tangent line of the wiper edge (5c) that is perpendicular to the extension line L1 of the main cutting edge (5b) is L2, and a tangent line of the wiper edge (5c) that passes through the end point P of the wiper edge (5c) which is toward the corner cutting edge (5a) is L3, the angle θ formed by the tangent line L2 and the tangent line L3 is within the range 0.010° ≤ θ ≤ 3.0° when viewed from the side facing the rake face (2).

Description

[Technical Field]

[0001] The present invention relates to a cutting insert and an indexable rotary cutting tool that is provided with the cutting insert and that is rotated about an axis. This application claims priority based on Japanese Patent Application No. 2022-103176, filed on June 28, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Conventionally, cutting tools used in processes that require reduced surface roughness, such as semi-finishing and finishing, include cutting inserts equipped with finishing edges (hereinafter also referred to as wiper edges) at the tangent points of the corner radius and straight edges. Most of these have straight wiper edges, but some cutting inserts have arc-shaped wiper edges. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-103710 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, Patent Document 1 shows a shape in which arc-shaped wiper blades are provided on both sides of the corner blade. It discloses that by setting appropriate wiper blades with arc shapes for both the bottom cutting edge and the side cutting edge, the roughness of the machined surface can be reduced.

[0005] However, the invention described in Patent Document 1 focuses on the surface roughness of the machined surface in the feed direction, and does not aim to reduce the amount of step difference that occurs in the radial direction. It also assumes a large-diameter tool that does not require a high level of finished surface accuracy. This is evident from the fact that Patent Document 1 states that the outer diameter of the rotary tool is φ50 and that Tables 1 and 2 of the same document show a relatively large surface roughness Rz of around 1.0 mm, even when the surface roughness of the machined surface is better. Furthermore, Patent Document 1 states that the workpiece is made of aluminum.

[0006] When cutting aluminum, the insert has a positive rake angle, which reduces the cutting edge angle, improving cutting performance. However, when cutting hard steel materials with such cutting inserts, chipping may occur.

[0007] Therefore, the tool described in Patent Document 1 is used for rough machining of aluminum materials, and is difficult to use for finishing steel materials, particularly for dies made of chromium-molybdenum alloy steel, such as those for automobile engines and drive components, which require high machining accuracy with a finished surface roughness of 5 μm or less.

[0008] The present invention has been made in consideration of the above circumstances, and one of its objects is to provide a cutting insert that can achieve a surface roughness of 5 μm or less on the machined surface, and an indexable rotary cutting tool equipped with the cutting insert. [Means for solving the problem]

[0009] [1] A cutting insert according to one aspect of the present invention comprises a rake face, a seating surface opposite to the rake face, a flank connecting the rake face and the seating surface, and a cutting edge formed on an intersecting ridge between the rake face and the flank, the cutting edge comprising a linear main cutting edge (peripheral cutting edge), a corner edge, and a wiper edge in this order, the main cutting edge (peripheral cutting edge) having a recess at an end opposite to the end connected to the corner edge, and the wiper edge is formed on the main cutting edge (peripheral cutting edge). The par blade is formed in an arc shape and is connected to the corner blade by a tangent, and when viewed from the side opposite the cutting face, when an extension line of the main cutting edge (peripheral blade) is defined as L1, a tangent line of the wiper blade that is perpendicular to the extension line L1 of the main cutting edge and passes through the end point P of the wiper blade on the corner blade side is defined as L2, the angle θ formed by the tangent line L2 and the tangent line L3 is within the range of 0.010°≦θ≦3.0°.

[0010] According to the above configuration, by making the wiper blade arc-shaped, in addition to the effect of reducing the roughness of the machined surface in the tool feed direction compared to the machined surface when the wiper blade is linear, the effect of reducing the steps between passes that occur in the tool radial direction is obtained, thereby increasing the flatness of the entire machined surface. Furthermore, by setting the angle θ between the tangent lines L2 and L3 within the range of 0.010°≦θ≦3.0°, the surface roughness of the machined surface can be reduced. The value of the angle θ is preferably within the range of 0.015°≦θ≦2.0°, and more preferably within the range of 0.020°≦θ≦1.0°. This further enhances the effects achieved by the arc-shaped wiper blade. The tool feed direction is the direction in which the indexable cutting tool advances while rotating during cutting, and the tool radial direction is the direction perpendicular to the tool feed direction. Here, if the angle θ formed by the tangent line L2 and the tangent line L3 is greater than 3.0°, the step between the passes in the tool radial direction increases, and the flatness of the machined surface deteriorates. On the other hand, if the angle θ between the tangent lines L2 and L3 is smaller than 0.010°, the wiper blade becomes too close to a straight line, and the above-mentioned effect obtained by the arc-shaped wiper blade cannot be fully obtained.

[0011] [2] In the cutting insert described in [1], the wiper edge may have a regular arc shape.

[0012] According to the above configuration, the wiper edge is formed in a regular arc shape, which makes it easier to manufacture the cutting insert, and as a result, the cutting insert can be manufactured with high precision.

[0013] [3] In the cutting insert described in [2], the wiper edge may have an arc radius R in the range of 50 mm≦R<200 mm.

[0014] When the wiper blade's arc radius R is less than 50 mm, the wiper blade protrudes significantly from the machined surface, making it difficult to reduce the roughness of the machined surface in the tool feed direction and the steps between passes in the tool radial direction, resulting in poor surface roughness of the machined surface. On the other hand, when the radius R of the wiper blade is 200 mm or more, the shape of the wiper blade approaches a straight line, and the effect of the arc shape is reduced. Here, the arc radius R of the wiper blade is preferably 50 mm≦R≦150 mm, and more preferably 100 mm≦R≦150 mm.

[0015] [4] In the cutting insert described in any one of [1] to [3], the cutting edge comprises the main cutting edge, the corner edge, the wiper edge, a straight inner cutting edge, and a second corner edge, the inner cutting edge is connected to the end of the wiper edge opposite to the end connected to the corner edge, the second corner edge is connected to the end of the inner cutting edge opposite to the end connected to the wiper edge, and the angle α formed between the main cutting edge and the inner cutting edge may be within the range of 80°≦α<90°.

[0016] When the angle α between the main cutting edge and the inner cutting edge is 80° or more, the volume of the cutting insert can be sufficiently secured, thereby improving the rigidity of the cutting insert.

[0017] [5] An indexable rotary cutting tool according to one aspect of the present invention comprises a rake face, a seating surface opposite to the rake face, a flank connecting the rake face and the seating surface, and a cutting edge formed on an intersecting ridge between the rake face and the flank, the cutting edge comprising a linear main cutting edge, a corner edge, and a wiper edge, in this order, the main cutting edge having a recess at an end opposite to the end connected to the corner edge, the wiper edge having an arc shape and connected to the corner edge by a tangent, and the wiper edge facing the rake face. When viewed from the direction of the wiper blade, an extension line of the main cutting edge is defined as L1, a tangent line to the wiper blade that is perpendicular to the extension line L1 is defined as L2, and a tangent line to the wiper blade that passes through an end point P of the wiper blade on the corner blade side is defined as L3.The angle θ between the tangent line L2 and the tangent line L3 is within the range of 0.010°≦θ≦3.0°.This is an indexable rotary cutting tool in which a cutting insert is attached to a tool body that can rotate around the axis of a rotation shaft, and the lowest point of the cutting insert in the direction along the rotation shaft is located on the wiper blade.

[0018] The lowest point is the point on the cutting insert attached to the tool body that is located at the tip end in the direction of the rotation axis. By locating the lowest point on the wiper edge rather than on the corner edge, the present invention allows the wiper edge to continue to contact the workpiece even when the indexable rotary cutting tool vibrates or bends under high-load cutting conditions. This reduces the surface roughness of the machined surface.

[0019] [6] In the indexable rotary cutting tool described in [5], the wiper edge of the cutting insert may have a regular arc shape when viewed from a direction facing the rake face.

[0020] [7] In the indexable rotary cutting tool described in [6], the wiper edge of the cutting insert may have an arc radius R of 50 mm≦R<200 mm. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a cutting insert capable of achieving a surface roughness of 5 μm or less on the machined surface, and an indexable rotary cutting tool equipped with the cutting insert. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view showing a cutting insert of the present embodiment. [Figure 2] FIG. 2 is a plan view showing the cutting insert of the present embodiment. [Figure 3] FIG. 3 is a side view of the short side of the cutting insert of the present embodiment. [Figure 4] FIG. 4 is a side view of the long side of the cutting insert of this embodiment. [Figure 5] FIG. 5 is a schematic diagram of the area surrounded by the two-dot chain line shown in FIG. [Figure 6] FIG. 6 is a perspective view of an indexable rotary cutting tool showing a state in which the cutting insert of this embodiment is attached to the tool body. [Figure 7] FIG. 7 is a perspective view of a tool body to which the cutting insert of this embodiment can be attached. [Figure 8] FIG. 8 is a diagram for explaining the tool feed direction and tool radial direction of an indexable cutting tool. DETAILED DESCRIPTION OF THE INVENTION

[0023] <Embodiment> The cutting insert and indexable rotary cutting tool of the present invention will be described below with reference to Figures 1 to 5. Note that the drawings used to explain the embodiments may show enlarged, highlighted, or excerpted essential parts in order to make the features of the present invention easier to understand.

[0024] (Cutting insert) Fig. 1 is a perspective view showing a cutting insert of this embodiment, Fig. 2 is a plan view showing the cutting insert of this embodiment, Fig. 3 is a short-side side view showing the cutting insert of this embodiment, and Fig. 4 is a long-side side view showing the cutting insert of this embodiment.

[0025] The cutting insert 1 of this embodiment has a polygonal shape when viewed from a direction along a center line CO extending in the thickness direction. In the following description, the direction along the center line CO may be simply referred to as the thickness direction. The direction perpendicular to the center line CO may be simply referred to as the width direction. Similarly, the circumferential direction around the axis centered on the center line CO may be simply referred to as the circumferential direction. In the following description, the tool feed direction is the direction in which the indexable cutting tool advances while rotating when cutting a workpiece, and the tool radial direction is the direction perpendicular to the tool feed direction. Fig. 8 is a diagram for explaining the tool feed direction A and the tool radial direction B. For example, the tool feed direction A with respect to the workpiece 8 shown in Fig. 8 is the direction along the X direction, and the tool radial direction B is the direction along the Y direction. The indexable rotary cutting tool 11 contacts the workpiece 8 from the Z direction, which is perpendicular to the X and Y directions.

[0026] 1 to 4, the cutting insert 1 has an upper surface which is a rake face 2, a lower surface which faces the rake face 2 which is a seating surface 3, and a side surface which connects the rake face 2 and the seating surface 3 which is a flank surface 4. The seating surface 3 is smaller than the rake face 2 in plan view, and is included inside the projection area of ​​the rake face 2 in the center line direction (thickness direction).

[0027] A cutting edge 5 is formed on the ridge where the rake face 2 and the flank 4 intersect. The cutting edge 5 comprises a corner edge (first corner edge) 5a located at the corner portion of the cutting face 2, a straight main cutting edge (peripheral edge) 5b connected to one end of the corner edge 5a, an arc-shaped wiper edge 5c connected to the other end of the corner edge 5a, a straight inner cutting edge 5d connected to the end of the wiper edge 5c opposite to the end connected to the corner edge 5a, and a second corner edge 5e connected to the end of the inner cutting edge 5d opposite to the end connected to the wiper edge 5c. The second corner cutting edge 5e is located at a corner (an obtuse-angled corner) different from the corner where the first corner cutting edge 5a is located, among the multiple corners of the rake face 2. The radius of curvature of the second corner cutting edge 5e is smaller than the radius of curvature of the first corner cutting edge 5a.

[0028] The main cutting edge 5b, corner edge 5a, wiper edge 5c, inner cutting edge 5d, and second corner edge 5e are arranged in this order clockwise in a plan view of the rake face 2, and form a rectangular plate that is rotationally symmetrical by 180° about the center line CO. The corner edge 5a and wiper edge 5c are smoothly connected. Each cutting edge may or may not function as a cutting edge depending on the machining method and machining shape. For example, when machining a vertical wall, the main cutting edge 5b is mainly used. The wiper blade 5c can be used for finishing the bottom surface, smoothing out uneven portions on the bottom surface and reducing the surface roughness of the processed surface. The corner blade 5a can be widely used for corners when machining vertical walls and for parts with many irregularities. The inner cutting edge 5d acts as a cutting edge in oblique cutting or the like.

[0029] As shown in FIG. 2, the angle α formed between the main cutting edge 5b formed on the long side of the rake face 2 and the inner cutting edge 5d formed on the short side is an acute angle. The angle α formed between the main cutting edge 5b and the inner cutting edge 5d, which are linear to each other, is, for example, within the range of 80°≦α<90°. When the angle α formed between the main cutting edge 5b and the inner cutting edge 5d is 80° or more, the volume of the cutting insert 1 can be sufficiently secured. As a result, the rigidity of the cutting insert 1 can be improved.

[0030] The value of the angle α is preferably within the range of 83°≦α≦89°, and more preferably within the range of 85°≦α≦88°, thereby enabling the rigidity of the cutting insert 1 to be further improved.

[0031] 1 and 2, the cutting insert 1 has a recess 6 at the end opposite to the end of the main cutting edge 5b connected to the corner edge 5a. By providing this recess 6, for example, when performing reciprocating machining, the end 6a (FIG. 2) of the recess 6 on the main cutting edge 5b side acts as a cutting edge.

[0032] FIG. 5 is a schematic diagram of the area surrounded by the two-dot chain line shown in FIG. In this embodiment, by making the wiper blade 5c of the main cutting edge 5b arc-shaped, in addition to the effect of reducing the roughness of the machined surface in the tool feed direction A (X direction) compared to machining when the wiper blade is linear, the step between passes that occurs in the tool radial direction B (Y direction) is reduced, thereby achieving the effect of improving the flatness of the entire machined surface.

[0033] Here, when an extension line of the main cutting edge 5b is defined as L1, a tangent line to the wiper edge 5c that is perpendicular to the extension line L1 is defined as L2, and a tangent line to the wiper edge 5c that passes through the end point P of the wiper edge 5c on the corner edge 5a side is defined as L3, the angle θ formed by the tangent line L2 and the tangent line L3 is within the range of 0.010°≦θ≦3.0°. By keeping the angle θ formed by the tangent line L2 and the tangent line L3 within the above range, the surface roughness of the machined surface can be reduced.

[0034] In other words, by making the curvature of the wiper blade 5c close to the curvature of the corner blade 5a, a step is less likely to occur between the wiper blade 5c and the corner blade 5a, and an angular shape is less likely to be formed at the boundary point P (the above-mentioned end point P) between the wiper blade 5c and the corner blade 5a. This makes cutter marks less noticeable and makes it possible to reduce the surface roughness of the machined surface.

[0035] Here, if the angle θ between the tangent line L2 and the tangent line L3 is greater than 3.0°, the amount by which the wiper blade 5c protrudes from the machined surface (protrusion amount L) is large, which increases the step between passes in the tool radial direction B and makes it impossible to obtain the desired surface roughness of the machined surface. The protrusion amount L may be the distance from the boundary point P between the wiper blade 5c and the corner blade 5a to the machined surface (tangent line L2 in this embodiment).

[0036] On the other hand, if the angle θ between the tangent lines L2 and L3 is less than 0.010°, the curved wiper blade 5c becomes too close to a straight line, and the effect of the arc-shaped wiper blade 5c cannot be fully obtained. When the wiper blade 5c becomes too close to a straight line, the effect of the arc-shaped shape is reduced.

[0037] Therefore, by setting the angle θ between the tangent line L2 and the tangent line L3 within the above range, it is possible to fully obtain the effects of the arc-shaped wiper blade 5c, such as reducing the roughness of the machined surface in the tool feed direction A (X direction) and reducing the steps between passes that occur in the tool radial direction B (Y direction), thereby improving the flatness of the entire machined surface.

[0038] The value of θ is preferably within the range of 0.015°≦θ≦2.0°, and more preferably within the range of 0.020°≦θ≦1.0°, thereby further enhancing the effects obtained by the arc-shaped wiper blade 5c.

[0039] Furthermore, the arc-shaped wiper blade 5c may have any shape, such as an ellipse, but is preferably a regular arc. Forming the wiper blade 5c into a regular arc facilitates the manufacture of the cutting insert 1. As a result, the cutting insert 1 can be obtained with good dimensional accuracy, and the accuracy of the machined surface is also improved.

[0040] In the case of the wiper blade 5c having a regular circular arc shape, the arc radius (curvature radius) R is preferably within the range of 50 mm≦R<200 mm. Here, the arc radius R of the wiper blade is preferably 50 mm≦R≦150 mm, and more preferably 100 mm≦R≦150 mm.

[0041] In this way, by setting the arc radius R of the wiper blade 5c within the range of 50 mm≦R<200 mm, when the cutting insert 1 is attached to the tool body 10 described below and used as an indexable rotary cutting tool 11, the roughness of the machined surface in the tool feed direction A (X direction) is reduced, and the steps between passes that occur in the tool radial direction B (Y direction) are reduced, thereby increasing the flatness of the entire machined surface and resulting in the effect of stabilizing the surface roughness of the machined surface.

[0042] 5, the width W of the wiper blade 5c in this embodiment is approximately 1.5 mm, but this can be changed as appropriate depending on the size of the cutting insert 1. Furthermore, by providing the lowest point Q on the wiper blade 5c, the surface roughness of the machined surface can be reduced. The lowest point Q is the point located at the tip end of the cutting insert attached to the tool body in the rotation axis direction.

[0043] (Indexable rotary cutting tool) Fig. 6 is a perspective view showing an indexable rotary cutting tool 11 in which the cutting insert 1 of this embodiment is attached to the tool body 10. Fig. 7 is a perspective view showing the tool body 10 to which the cutting insert 1 of this embodiment can be attached.

[0044] 6, the indexable rotary cutting tool 11 has a tool body 10 and a plurality of cutting inserts 1. In this embodiment, for example, four cutting inserts 1 are included. The indexable rotary cutting tool 11 performs cutting by rotating the tool body 10 in a rotation direction TD about a rotation axis JO.

[0045] 7, in this embodiment, four insert mounting seats 33 are formed at the tip portion of the tool body 10, corresponding to the number of cutting inserts 1 to be attached. The number of insert mounting seats 33 increases or decreases depending on the tool diameter of the indexable rotary cutting tool 11. Therefore, when the tool diameter is large, the number of insert mounting seats 33 increases, and conversely, when the tool diameter is small, the number of insert mounting seats 33 decreases.

[0046] The insert mounting seat 33 has a mounting seat bottom surface 33a and a pair of mounting seat wall surfaces 33b. The mounting seat bottom surface 33a has a rectangular shape with an area substantially equal to that of the seating surface 3 of the cutting insert 1, and faces the rotation direction TD of the tool body 10. The pair of mounting seat wall surfaces 33b are surfaces that extend from two sides of the mounting seat bottom surface 33a toward the rotation direction TD.

[0047] The mounting seat bottom surface 33 a faces and contacts the seating surface 3 of the cutting insert 1 . Of the pair of mounting seat wall surfaces 33b, the mounting seat wall surface 33b along the axial direction faces and contacts the side surface along the long side of the cutting insert 1. Of the pair of mounting seat wall surfaces 33b, the mounting seat wall surface 33b along the radial direction faces and contacts the side surface along the short side of the cutting insert 1. In other words, the pair of mounting seat wall surfaces 33b faces and contacts the flank surface of the cutting insert 1.

[0048] A threaded hole 33c is formed in approximately the center of the mounting seat bottom surface 33a. The threaded hole 33c is a hole that can communicate with the mounting hole 7 formed in the center of the cutting insert 1. A mounting screw 12 is inserted into the threaded hole 33c when mounting the cutting insert 1.

[0049] The cutting insert 1 is attached to the tool body 10 by inserting a mounting screw 12 into a mounting hole 7 formed in the center of the cutting insert 1 and tightening it into a threaded hole 33c formed in the center of the mounting seat bottom surface 33a of the tool body 10. In this way, the multiple cutting inserts 1 are detachably attached to the respective insert mounting seats 33 of the tool body 10 using the mounting screws 12.

[0050] In this embodiment, the indexable rotary cutting tool 11 has four cutting inserts attached to the tool body 10, all of which have arc-shaped wiper blades 5c. By setting the arc radius of the wiper blades 5c within the above range, it is possible to achieve a surface roughness of the machined surface that is the target value of 5 μm or less, thereby reducing the roughness of the machined surface in the tool feed direction A (X direction) and reducing the step between passes that occurs in the tool radial direction B (Y direction), thereby improving the flatness of the entire machined surface. This stabilizes the surface roughness of the machined surface and allows for a finished surface with high machining accuracy.

[0051] As a result, the indexable rotary cutting tool 11 of this embodiment can be used to machine die molds made of hard chromium-molybdenum alloy steel, such as those used in automobile engines and drive components, which require high machining accuracy.

[0052] In the indexable rotary cutting tool 11 of this embodiment, the lowest point Q of the cutting insert 1 in the direction along the rotation axis JO is located on the wiper edge 5c. By providing the lowest point Q on the wiper edge 5c, even if the indexable rotary cutting tool 11 vibrates or the indexable rotary cutting tool 11 itself bends under cutting conditions with a high load, the wiper edge 5c can be kept in contact with the workpiece 8. This makes it possible to reduce the surface roughness of the machined surface. [Example]

[0053] In order to confirm the effects of the present invention, cutting tests were carried out using the cutting inserts shown in Table 1 (Examples 1 to 3, Comparative Examples 1 and 2). The processing conditions are as follows:

[0054] (Processing conditions) Workpiece: Chromium-molybdenum alloy steel (46.5HRC) ·Tool diameter: φ25mm ·Cutting speed Vc:275m / min Feed per tooth fz: 0.057mm / t Axial depth of cut ap: 0.04 mm Radial cutting depth ae: 20 mm - Protruding length OH: 175mm Coolant: Air

[0055] [Table 1]

[0056] The results of the cutting test described above are shown in Table 2.

[0057] [Table 2]

[0058] As can be seen from Table 2, the surface roughness of the machined surface achieved the target value of 5 μm or less in all of Examples 1 to 3. On the other hand, in both Comparative Examples 1 and 2, the surface roughness of the machined surface was greater than 5 μm compared to Examples 1 to 3. From the above, it was shown that the cutting inserts of Examples 1 to 3 provided good results.

[0059] In addition, the various configurations (elements) described in the above embodiments and notes may be combined, and additions, omissions, substitutions, and other modifications of the configurations are possible, without departing from the spirit of the present invention. The present invention is not limited to the above embodiments, but is limited only by the claims. [Industrial Applicability]

[0060] According to the present invention, it is possible to provide a cutting insert that can achieve a surface roughness of 5 μm or less on the machined surface, and an indexable rotary cutting tool equipped with the cutting insert. [Explanation of symbols]

[0061] 1...Cutting insert 2...Scooping surface 3...Seating surface 4...Flank 5...Cutting edge 5a...Corner blade 5b…Main cutting edge 5c...Wiper blade 5d…Inner cutting blade 5e...2nd corner blade 6...Recess 10...Tool body 11...Indexable rotary cutting tools JO...Rotation axis L1…extension line L2,L3…tangent P...Boundary point (end point) Q...Tool lowest point (lowest point) L: Protrusion of the wiper blade 5c from the processed surface R...Arc radius α: Angle between the main cutting edge 5b and the inner cutting edge 5d θ...the angle between tangent L2 and tangent L3

Claims

1. A cutting insert having a polygonal shape centered on a central axis, The scooping surface and a seating surface facing the rake face; a flank surface connecting the rake face and the seating surface; a cutting edge formed on an intersection ridge between the rake face and the flank face, The cutting edge includes a linear main cutting edge, a corner edge, and a wiper edge in this order, A recess recessed toward the central axis is provided at an end of the main cutting edge opposite to an end connected to the corner edge, When viewed from a direction facing the rake face, The wiper blade is formed in an arc shape and is connected to the corner blade by a tangent line, An extension line of the main cutting edge is L1, a line perpendicular to the extension line L1 and tangent to the wiper edge is L2, When a tangent to the wiper blade passing through an end point P on the corner blade side of the wiper blade is defined as L3, an angle θ formed between the tangent L2 and the tangent L3 is within a range of 0.010°≦θ≦3.0°. Cutting insert.

2. When viewed from a direction facing the rake face, The wiper blade is characterized in that it has a regular arc shape. The cutting insert according to claim 1 .

3. The arc radius R of the wiper blade is in the range of 50 mm≦R<200 mm. The cutting insert according to claim 2 .

4. The cutting edge includes the main cutting edge, the corner edge, the wiper edge, a linear inner cutting edge, and a second corner edge, the inner cutting edge is connected to an end of the wiper blade opposite to an end connected to the corner edge, the second corner edge is connected to an end of the inner cutting edge opposite to an end connected to the wiper edge, The angle α formed between the main cutting edge and the inner cutting edge is in the range of 80°≦α<90°. The cutting insert according to claim 1 or 2.

5. An indexable rotary cutting tool in which a polygonal cutting insert centered on a central axis is attached to a tool body that can rotate around a rotation axis, The cutting insert comprises: a cutting edge formed on an intersecting ridge between the rake face and the flank face, the cutting edge comprising a linear main cutting edge, a corner edge, and a wiper edge, in this order; an end of the main cutting edge opposite to the end connected to the corner edge is provided with a recess recessed toward the central axis; when viewed from a direction facing the rake face, the wiper edge is formed in an arc shape and connected to the corner edge by a tangent; an extension line of the main cutting edge is defined as L1, a tangent line of the wiper edge perpendicular to the extension line L1 is defined as L2, and a tangent line of the wiper edge passing through an end point P of the wiper edge on the corner edge side is defined as L3; an angle θ formed by the tangent line L2 and the tangent line L3 is within a range of 0.010°≦θ≦3.0°; a lowest point of the cutting insert in a direction along the rotation axis is located on the wiper edge; Indexable rotary cutting tool.

6. When viewed from a direction facing the rake face, The wiper edge of the cutting insert has a regular arc shape. The indexable rotary cutting tool according to claim 5 .

7. The arc radius R of the wiper edge of the cutting insert is 50 mm≦R<200 mm. The indexable rotary cutting tool according to claim 6.

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