Cutting insert and indexable insert type rotary cutting tool

Abstract

This cutting insert (1) is provided with: a rake surface (2); a seating surface (3) facing the rake surface (2); a flank surface (4) connecting the rake surface (2) and the seating surface (3); and a cutting edge (5) formed on an intersecting ridge line between the rake face (2) and the flank face (4), the cutting edge (5) is sequentially provided with a linear main cutting edge (5b), an edge corner (5a), and a sleeking edge (5c), the end of the main cutting edge (5b) opposite to the end connected to the edge corner (5a) is provided with a recess (6), and the sleeking edge (5c) is formed in an arc shape and is connected to the edge corner (5a) by a tangent line. When viewed from the side facing the rake face (2), the extension line of the main cutting edge (5b) is L1, the tangent line of the sleeking edge (5c) perpendicular to the extension line L1 of the main cutting edge (5b) is L2, and the tangent line of the sleeking edge (5c) passing through the edge angle (5a) side end point P of the sleeking edge (5c) is L3, the angle (theta) formed by the tangent line L2 and the tangent line L3 is within the range of 0.010 DEG < = theta < = 3.0 DEG.

Description

Technical Field

[0001] The present invention relates to a cutting insert and an indexable insert type rotary cutting tool which has the cutting insert and rotates around an axis.

[0002] This application claims priority based on patent application No. 2022-103176 filed in Japan on June 28, 2022, and its contents are incorporated herein. Background Art

[0003] Conventionally, in cutting tools used in processes such as semi-finishing and / or finishing that require the reduction of the surface roughness of the machined surface, there are cutting inserts having a finishing edge (hereinafter also referred to as a wiper edge) at the corner radius and the tangent portion of the straight edge. Although most of them have a straight-line wiper edge, there are also cutting inserts having an arc-shaped wiper edge.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2005-103710

[0005] For example, Patent Document 1 shows a shape of a wiper edge having an arc shape on both sides of the edge corner. It is disclosed that the machined surface roughness is reduced by setting the bottom cutting edge, the side cutting edge, and the appropriate wiper edge in an arc shape.

[0006] However, the invention described in Patent Document 1 focuses on the surface roughness of the machined surface in the feed direction, and is not intended to reduce the height difference generated in the radial direction. In addition, a large-diameter tool that does not require a high precision of the finished surface is envisioned. This is obvious from the following: in Patent Document 1, in addition to recording the outer diameter of the rotating tool as φ50, in Tables 1 and 2 of the document, even when the surface roughness of the machined surface is better, the surface roughness Rz is shown as a relatively large value of about 1.0 mm. In addition, Patent Document 1 records that the workpiece is made of aluminum.

[0007] When the workpiece is made of aluminum, the cutting performance is improved by making the rake angle positive and reducing the wedge angle. If such a cutting insert is used to cut a hard steel material, chipping may occur.

[0008] Therefore, the tool described in Patent Document 1 is used for rough machining of aluminum materials, but is difficult to be used for finish machining of steel materials. In particular, it is difficult to be used for molds of automobile engines and / or drive parts, which are mostly made of chromium-molybdenum alloy steel materials and require high machining accuracy of the finish surface with a surface roughness of 5 μm or less. Summary of the invention

[0009] The present invention has been made in view of the above circumstances, and one object of the present invention is to provide a cutting insert capable of achieving a surface roughness of a processed surface of 5 μm or less, and an indexable insert type rotary cutting tool including the cutting insert.

[0010] [1] A cutting insert according to one embodiment of the present invention is characterized in that it comprises: a rake face; a seating face opposite to the rake face; a flank face connecting the rake face and the seating face; and a cutting edge formed on an intersecting ridgeline between the rake face and the flank face, wherein the cutting edge comprises a straight main cutting edge (peripheral cutting edge), a cutting edge corner, and a wiper cutting edge in sequence, and a recess is provided at an end portion of the main cutting edge (peripheral cutting edge) on the side opposite to the end portion connected to the cutting edge corner, The wiper edge is formed in an arc shape and is connected to the edge corner by a tangent line. When viewed from the side opposite to the rake face, an extension line of the main cutting edge (peripheral edge) is set as L1, a tangent line of the wiper edge perpendicular to the extension line L1 of the main cutting edge is set as L2, and a tangent line of the wiper edge passing through an end point P on the edge corner side of the wiper edge is set as L3, an angle θ formed by the tangent line L2 and the tangent line L3 is in the range of 0.010°≤θ≤3.0°.

[0011] According to the above configuration, by setting the wiper edge to an arc shape, in addition to reducing the roughness of the machined surface in the tool feed direction, compared with the machined surface when the wiper edge is a straight line, an effect is also achieved in which the height difference between paths generated in the tool radial direction is reduced and the overall flatness of the machined surface is improved.

[0012] Furthermore, by setting the angle θ formed by the tangent line L2 and the tangent line L3 in the range of 0.010°≤θ≤3.0°, the surface roughness of the processed surface can be reduced. In addition, the value of the angle θ is preferably in the range of 0.015°≤θ≤2.0°, and more preferably in the range of 0.020°≤θ≤1.0°. Thus, the above-mentioned effect obtained by the arc-shaped wiper edge can be further improved.

[0013] It should be noted that the tool feed direction refers to the direction in which the indexable insert type cutting tool moves forward while rotating during cutting, and the tool radial direction refers to the direction perpendicular to the tool feed direction.

[0014] Here, when the angle θ formed by the tangent line L2 and the tangent line L3 is larger than 3.0°, the height difference between the paths generated in the tool radial direction increases, and the flatness of the machined surface deteriorates.

[0015] On the other hand, when the angle θ formed by the tangent line L2 and the tangent line L3 is smaller than 0.010°, the wiper cutting edge is too close to a straight line, and the above-mentioned effect obtained by the arc-shaped wiper cutting edge cannot be fully obtained.

[0016] [2] In the cutting insert described in [1], the wiper edge may be in a perfect circular arc shape.

[0017] According to the above configuration, the cutting insert can be easily manufactured by forming the wiper edge into a perfect arc shape. As a result, the cutting insert can be manufactured with good precision.

[0018] [3] In the cutting insert described in [2], the arc radius R of the wiper edge may be 50 mm ≤ R < 200 mm.

[0019] When the arc radius R of the wiper edge is less than 50 mm, the amount of protrusion of the wiper edge relative to the machined surface is large, so it is difficult to reduce the machined surface roughness in the tool feed direction and the height difference between paths generated in the tool radial direction, and the surface roughness of the machined surface deteriorates.

[0020] On the other hand, when the arc radius R of the wiper cutting edge is 200 mm or more, the shape of the wiper cutting edge is close to a straight line, so the effect of the arc shape becomes small.

[0021] Here, the arc radius R of the wiper cutting edge is preferably 50 mm ≤ R ≤ 150 mm, and more preferably 100 mm ≤ R ≤ 150 mm.

[0022] [4] In the cutting insert described in any one of [1] to [3], the cutting edge may be composed of the main cutting edge, the edge corner, the wiper edge, a linear inner cutting edge, and a second edge corner, the inner cutting edge is connected to an end portion of the wiper edge opposite to an end portion connected to the edge corner, the second edge corner is connected to an end portion of the inner cutting edge opposite to an end portion connected to the wiper edge, and an angle α formed by the main cutting edge and the inner cutting edge is in the range of 80°≤α<90°.

[0023] If the angle α formed by the main cutting edge and the inner cutting edge is 80° or more, the volume of the cutting insert can be sufficiently ensured. As a result, the rigidity of the cutting insert can be improved.

[0024] [5] An embodiment of the present invention is a rotary cutting tool with an indexable insert, characterized in that a cutting insert is mounted on a tool body that can rotate around an axis of rotation, the cutting insert comprising: a front cutting face; a seating face opposite to the front cutting face; a rear cutting face connecting the front cutting face and the seating face; and a cutting edge formed on an intersecting ridge between the front cutting face and the rear cutting face, the cutting edge comprising, in sequence, a straight main cutting edge, a cutting angle, and a finishing edge, and a cutting edge is provided at the end of the main cutting edge on the opposite side of the end connected to the cutting angle. A concave portion is provided, the wiper edge is formed in an arc shape and is connected to the edge corner by a tangent, and when viewed from a direction opposite to the rake face, an extension line of the main cutting edge is set as L1, a tangent line of the wiper edge perpendicular to the extension line L1 is set as L2, and a tangent line of the wiper edge passing through an end point P on the edge corner side of the wiper edge is set as L3, an angle θ formed by the tangent line L2 and the tangent line L3 is in a range of 0.010°≤θ≤3.0°, and the lowest point of the cutting insert in the direction along the rotation axis is located on the wiper edge.

[0025] The so-called lowest point refers to the point located at the front end in the direction of the rotation axis of the cutting blade installed on the tool body. The present invention has the lowest point of the tool on the wiper edge rather than on the edge corner, so that under high-load cutting conditions, even if the indexable insert type rotary cutting tool vibrates or the indexable insert type rotary cutting tool itself is bent, the wiper edge can continue to abut against the workpiece. As a result, the surface roughness of the machined surface can be reduced.

[0026] [6] In the insert-type rotary cutting tool described in [5], the wiper edge of the cutting insert may be in a perfect circular arc shape when viewed from a direction facing the rake face.

[0027] [7] In the indexable insert type rotary cutting tool described in [6], the arc radius R of the wiper edge of the cutting insert may also be 50 mm ≤ R < 200 mm.

[0028] 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 a processed surface, and an indexable-insert type rotary cutting tool including the cutting insert. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a perspective view showing the cutting insert according to the present embodiment.

[0030] Figure 2 It is a plan view showing the cutting insert according to the present embodiment.

[0031] Figure 3 This is a side view showing the short side of the cutting insert according to the present embodiment.

[0032] Figure 4 This is a side view showing the long side of the cutting insert according to the present embodiment.

[0033] Figure 5 yes Figure 2 Schematic diagram of the area enclosed by the double-dashed line shown.

[0034] Figure 6 It is a perspective view of the insert-replaceable rotary cutting tool showing a state in which the cutting insert according to the present embodiment is mounted on a tool body.

[0035] Figure 7 This is a perspective view of a tool body to which the cutting insert according to the present embodiment can be mounted.

[0036] Figure 8 It is a diagram for explaining the tool feed direction and tool radius direction of an indexable insert type cutting tool. DETAILED DESCRIPTION

[0037] <Implementation Method>

[0038] Below, refer to Figure 1 to Figure 5 The cutting insert and the insert-replaceable rotary cutting tool of the present invention will be described. It should be noted that, in order to facilitate understanding of the features of the present invention, the drawings used in the description of the embodiments may be enlarged, coordinated, or extracted to show the main parts.

[0039] (Cutting inserts)

[0040] Figure 1 It is a perspective view showing the cutting insert according to the present embodiment. Figure 2 It is a plan view showing the cutting insert according to the present embodiment. Figure 3 This is a side view showing the short side of the cutting insert according to the present embodiment. Figure 4 This is a side view showing the long side of the cutting insert according to the present embodiment.

[0041] The cutting insert 1 of the present embodiment has a polygonal shape when viewed from the direction along the center line CO extending in the thickness direction.

[0042] In the following description, the direction along the center line CO is sometimes referred to as the thickness direction. The direction perpendicular to the center line CO is sometimes referred to as the width direction. Similarly, the circumferential direction around the axis with the center line CO as the center is sometimes referred to as the circumferential direction.

[0043] In the following description, the tool feed direction refers to the direction in which the indexable insert cutting tool moves forward while rotating when cutting a workpiece, and the tool radius direction refers to the direction perpendicular to the tool feed direction. Figure 8It is a diagram for explaining the tool feed direction A and the tool radius direction B. For example, Figure 8 The tool feed direction A shown relative to the workpiece 8 is along the X direction, and the tool radial direction B is along the Y direction. The indexable insert type rotary cutting tool 11 abuts against the workpiece 8 in the Z direction orthogonal to the X and Y directions.

[0044] like Figure 1 to Figure 4 As shown, the upper surface of the cutting insert 1 is a rake face 2, the lower surface opposite to the rake face 2 is a seating face 3, and the side surface connecting the rake face 2 and the seating face 3 is a flank face 4. The size of the seating face 3 when viewed from above is smaller than the size of the rake face 2 when viewed from above, and is enclosed inside the projection area of ​​the rake face 2 in the center line direction (thickness direction).

[0045] A cutting edge 5 is formed on an intersecting ridgeline between the rake face 2 and the flank face 4 .

[0046] The cutting edge 5 includes: a cutting edge corner (first cutting edge corner) 5a located at a corner portion of the rake face 2; a straight main cutting edge (peripheral cutting edge) 5b connected to one end side of the cutting edge corner 5a; an arc-shaped wiper cutting edge 5c connected to the other end side of the cutting edge corner 5a; a straight inner cutting edge 5d connected to the end of the wiper cutting edge 5c on the opposite side to the end connected to the cutting edge corner 5a; and a second cutting edge 5e connected to the end of the inner cutting edge 5d on the opposite side to the end connected to the wiper cutting edge 5c.

[0047] The second edge corner 5e is located at a corner (an obtuse corner) different from the corner where the first edge corner 5a is located among the plurality of corners of the rake face 2. The curvature radius of the second edge corner 5e is smaller than the curvature radius of the first edge corner 5a.

[0048] The main cutting edge 5b, the edge corner 5a, the wiper edge 5c, the inner cutting edge 5d and the second edge corner 5e are sequentially arranged in a right-handed (clockwise) manner in a top view of the rake face 2, and are formed into a rectangular plate shape that is rotationally symmetrical by 180° with respect to the center line CO. In addition, the edge corner 5a is smoothly connected to the wiper edge 5c.

[0049] Each cutting edge may function as a cutting edge or may not function as a cutting edge depending on the processing method and / or the processing shape. For example, in vertical wall processing, the main cutting edge 5b is mainly used.

[0050] The wiper cutting edge 5 c can be used for bottom surface finishing, and can smooth the concavo-convex portions of the bottom surface and reduce the surface roughness of the processed surface.

[0051] The cutting edge 5a can be widely used for corners and / or shapes with many irregularities during wall processing.

[0052] The inner cutting edge 5d functions as a cutting edge in inclined cutting and the like.

[0053] like Figure 2 As shown in the figure, the angle α formed by 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 by the main cutting edge 5b and the inner cutting edge 5d in a straight line is, for example, in the range of 80°≤α<90°. If the angle α formed by 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 ensured. As a result, the rigidity of the cutting insert 1 can be improved.

[0054] It should be noted that the value of α is preferably within the range of 83°≤α≤89°, and more preferably within the range of 85°≤α≤88°. Thereby, the rigidity of the cutting insert 1 can be further improved.

[0055] like Figure 1 and Figure 2 As shown in FIG. 1 , the cutting insert 1 is provided with a recessed portion 6 at the end portion of the main cutting edge 5b opposite to the end portion connected to the edge corner 5a. By providing the recessed portion 6, for example, when performing reciprocating processing, the recessed portion 6 is at the end portion 6a ( Figure 2 ) acts as a cutting edge.

[0056] Figure 5 yes Figure 2 Schematic diagram of the area enclosed by the double-dashed line shown.

[0057] In this embodiment, by setting the wiper edge 5c of the main cutting edge 5b to an arc shape, compared with the processing when the wiper edge is a straight line shape, in addition to reducing the effect of reducing the roughness of the machined surface in the tool feed direction A (X direction), it is also possible to reduce the height difference between the paths generated in the tool radius direction B (Y direction) and improve the overall flatness of the machined surface.

[0058] Here, when the extension line of the main cutting edge 5b is set to L1, the tangent line of the wiper edge 5c perpendicular to the extension line L1 is set to L2, and the tangent line of the wiper edge 5c passing through the end point P on the edge angle 5a side of the wiper edge 5c is set to L3, the angle θ formed by the tangent line L2 and the tangent line L3 is included in the range of 0.010°≤θ≤3.0°. By setting the angle θ formed by the tangent line L2 and the tangent line L3 to be within the above range, the surface roughness of the processed surface can be reduced.

[0059] That is, by setting the curvature of the flat edge 5c close to that of the corner 5a, a height difference is less likely to occur between the flat edge 5c and the corner 5a, and an angle is less likely to be formed at the boundary point P (the above-mentioned end point P) between the flat edge 5c and the corner 5a.

[0060] Therefore, the tool mark becomes less noticeable and the surface roughness of the processed surface can be reduced.

[0061] Here, when the angle θ formed by the tangent line L2 and the tangent line L3 is greater than 3.0°, the amount of protrusion of the wiper edge 5c relative to the machined surface (protrusion amount L) is large, so the height difference between the paths generated in the tool radius direction B increases, and the desired surface roughness of the machined surface cannot be obtained. The protrusion amount L may also be the distance from the boundary point P between the wiper edge 5c and the edge angle 5a to the machined surface (tangent line L2 in this embodiment).

[0062] On the other hand, when the angle θ formed by the tangent lines L2 and L3 is less than 0.010°, the curved wiper edge 5c is too close to a straight line, and the effect of the arc-shaped wiper edge 5c cannot be fully obtained.

[0063] Therefore, by setting the angle θ formed by the tangent line L2 and the tangent line L3 within the above range, the effect of reducing the roughness of the machined surface in the tool feed direction A (X direction) and the effect based on the arc-shaped polishing edge 5c of reducing the height difference between the paths generated in the tool radius direction B (Y direction) and improving the overall flatness of the machined surface can be fully obtained.

[0064] It should be noted that 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°. This can further enhance the above-mentioned effect obtained by the arc-shaped wiper cutting edge 5c.

[0065] In addition, the arc-shaped wiper edge 5c can be in an arc shape, or in a curved shape such as an ellipse, but is preferably in a perfect arc shape. By forming the wiper edge 5c in a perfect arc shape, the manufacturing of the cutting insert 1 becomes easy. As a result, a cutting insert 1 with good dimensional accuracy can be obtained, and the processing surface accuracy is also improved.

[0066] Here, in the case of the right arc-shaped wiper edge 5c, its arc radius (curvature radius) R is preferably in the range of 50 mm ≤ R < 200 mm. Here, the arc radius R of the wiper edge is preferably 50 mm ≤ R ≤ 150 mm, and more preferably 100 mm ≤ R ≤ 150 mm.

[0067] In this way, by setting the arc radius R of the polishing edge 5c to within the range of 50mm≤R<200mm, when the cutting insert 1 is mounted on the tool body 10 described later and used as an indexable insert type rotary cutting tool 11, the surface roughness of the machined surface can be stabilized by reducing the effect of reducing the roughness of the machined surface in the tool feed direction A (X direction), and reducing the height difference between the paths generated in the tool radius direction B (Y direction) and improving the overall flatness of the machined surface, so that the surface roughness of the machined surface can be stabilized.

[0068] In addition, if Figure 5 As shown in FIG. 1 , the width W of the wiper edge 5c of the present embodiment is about 1.5 mm, but it can be appropriately changed according to the size of the cutting insert 1. Furthermore, by setting the lowest point Q on the wiper edge 5c, the surface roughness of the machined surface can be reduced. The lowest point Q refers to the point located at the front end in the direction of the rotation axis in the cutting insert mounted on the tool body.

[0069] (Indexable insert type rotary cutting tool)

[0070] Figure 6 It is a perspective view of the insert-replaceable rotary cutting tool 11 showing a state in which the cutting insert 1 according to the present embodiment is mounted on a tool body 10 . Figure 7 It is a perspective view showing a tool body 10 to which the cutting insert 1 of the present embodiment can be mounted.

[0071] like Figure 6 As shown, the insert-replaceable rotary cutting tool 11 includes a tool body 10 and a plurality of cutting inserts 1. In the present embodiment, for example, there are four cutting inserts 1. The insert-replaceable rotary cutting tool 11 performs cutting processing by rotating the tool body 10 in the rotation direction TD around the rotation axis JO.

[0072] like Figure 7 As shown, in this embodiment, four insert mounting seats 33 are formed on the front end portion of the tool body 10 in correspondence with the number of the mounted cutting inserts 1. The number of the insert mounting seats 33 increases or decreases according to the tool diameter of the indexable insert type rotary cutting tool 11. Therefore, when the tool diameter is large, the number of the insert mounting seats 33 is large, and conversely, when the tool diameter is small, the number of the insert mounting seats 33 is small.

[0073] The insert mounting seat 33 has a mounting seat bottom surface 33 a and a pair of mounting seat wall surfaces 33 b .

[0074] The seat bottom surface 33a has a rectangular shape having 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 seat wall surfaces 33b extend from both sides of the seat bottom surface 33a toward the rotation direction TD.

[0075] The mounting seat bottom surface 33 a is opposed to and in contact with the seating surface 3 of the cutting insert 1 .

[0076] The axial mounting seat wall surface 33b of the pair of mounting seat wall surfaces 33b contacts the side surface along the long side of the cutting insert 1. The radial mounting seat wall surface 33b of the pair of mounting seat wall surfaces 33b contacts the side surface along the short side of the cutting insert 1. That is, the pair of mounting seat wall surfaces 33b face the flank surface of the cutting insert 1 and contact them.

[0077] A screw hole 33c is formed substantially at the center of the mounting seat bottom surface 33a. The screw hole 33c is a hole that can communicate with the mounting hole 7 formed at the center of the cutting insert 1. The mounting screw 12 for mounting the cutting insert 1 is inserted into the screw hole 33c.

[0078] The cutting insert 1 is mounted on the tool body 10 by fastening the mounting screw 12 inserted into the mounting hole 7 formed in the center thereof to the screw hole 33c formed in the center of the mounting seat bottom surface 33a of the tool body 10. In this way, the plurality of cutting inserts 1 are detachably mounted on each insert mounting seat 33 of the tool body 10 using the mounting screw 12.

[0079] With regard to the indexable insert type rotary cutting tool 11 of the present embodiment, all four cutting inserts mounted on the tool body 10 have arc-shaped wiper edges 5c. By setting the arc radius of the wiper edge 5c within the above range, the surface roughness of the machined surface can be set to a target value of 5 μm or less, thereby achieving the effect of reducing the roughness of the machined surface in the tool feed direction A (X direction), and reducing the height difference between the paths generated in the tool radius direction B (Y direction) and improving the overall flatness of the machined surface. Therefore, a finished surface with stable surface roughness and high machining accuracy can be obtained.

[0080] As a result, the insert-replaceable rotary cutting tool 11 of the present embodiment can be used for machining dies made of hard chromium-molybdenum alloy steel materials such as automobile engines and drive parts requiring high machining accuracy.

[0081] In the indexable insert type rotary cutting tool 11 of the present embodiment, the lowest point Q of the cutting insert 1 in the direction of the rotation axis JO is located on the wiper edge 5c. By providing the lowest point Q on the wiper edge 5c, under the cutting condition where a high load is applied, even when the indexable insert type rotary cutting tool 11 vibrates or the indexable insert type rotary cutting tool 11 itself is bent, the wiper edge 5c can be continuously abutted against the workpiece 8. As a result, the surface roughness of the machined surface can be reduced.

[0082] Example

[0083] In order to confirm the effect of the present invention, a cutting test was carried out using the cutting inserts shown in Table 1 (Examples 1 to 3, Comparative Examples 1 and 2).

[0084] In addition, the processing conditions are as follows.

[0085] (Processing conditions)

[0086] Workpiece: Chrome-molybdenum alloy steel (46.5HRC)

[0087] Tool diameter: φ25mm

[0088] Cutting speed Vc: 275m / min

[0089] Feed per blade fz: 0.057mm / t

[0090] Axial cutting depth ap: 0.04mm

[0091] Radial cutting depth ae: 20mm

[0092] ·Protruding length OH: 175mm

[0093] Coolant: Air

[0094] [Table 1]

[0095] With or without wiper blade θ Wiper edge R dimension Wiper edge width Example 1 have 0.083° R50mm 1.5mm Example 2 have 0.045° R100mm 1.5mm Example 3 have 0.018° R150mm 1.5mm Comparative Example 1 have 0.003° R200mm 1.5mm Comparative Example 2 none - - -

[0096] Table 2 shows the results of the cutting test.

[0097] [Table 2]

[0098] θ Wiper edge R dimension Maximum surface roughness Example 1 0.083° R50mm 4.3μm Example 2 0.045° R100mm 2.6μm Example 3 0.018° R150mm 2.9μm Comparative Example 1 0.003° R200mm 6.0μm Comparative Example 2 - - 5.3μm

[0099] According to Table 2, the surface roughness of the processed surface in Examples 1 to 3 all reached the target value of 5 μm or less. On the other hand, compared with Examples 1 to 3, the surface roughness of the processed surface in Comparative Examples 1 and 2 was greater than 5 μm.

[0100] As can be seen from the above, the cutting inserts of Examples 1 to 3 provide good results.

[0101] In addition, within the scope of not departing from the gist of the present invention, the various structures (structural elements) described in the aforementioned embodiments and the "should be explained" section, etc. may be combined, and the structures may be added, omitted, replaced, or otherwise changed. In addition, the present invention is not limited to the aforementioned embodiments, but only to the claims.

[0102] Industrial Applicability

[0103] 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 a processed surface, and an indexable-insert type rotary cutting tool including the cutting insert.

[0104] Description of Reference Numerals

[0105] 1 Cutting blade

[0106] 2 Rake face

[0107] 3 Seating surface

[0108] 4. Flank

[0109] 5 cutting edges

[0110] 5a blade angle

[0111] 5b main cutting edge

[0112] 5c Wiper Edge

[0113] 5d inner cutting edge

[0114] 5e Second Edge

[0115] 6 recesses

[0116] 10 Tool body

[0117] 11Indexable insert type rotary cutting tool

[0118] JO Rotation Axis

[0119] L1 extension cable

[0120] L2, L3 tangent

[0121] P Boundary point (end point)

[0122] Q Tool Lowest Point (Lowest Point)

[0123] L The protrusion amount of the wiper edge 5c relative to the processed surface

[0124] R Arc radius

[0125] α Angle between the main cutting edge 5b and the inner cutting edge 5d

[0126] θAngle between tangent line L2 and tangent line L3

Claims

1. A cutting insert, characterized in that: have: Rake face; A seating surface opposite to the front cutting surface; a flank surface connecting the rake surface and the seating surface; and a cutting edge formed on an intersecting ridgeline between the rake face and the flank face, The cutting edge has a straight main cutting edge, an edge angle and a wiper edge in sequence. A recess is provided at an end portion of the main cutting edge opposite to an end portion connected to the cutting edge corner. The wiper edge is formed in an arc shape and connected to the edge corner by a tangent line. When viewed from the side opposite to the front cutting edge, When an extension line of the main cutting edge is set as L1, a tangent line of the wiper edge perpendicular to the extension line L1 is set as L2, and a tangent line of the wiper edge passing through an end point P on the edge angle side of the wiper edge is set as L3, an angle θ formed by the tangent line L2 and the tangent line L3 is in a range of 0.010°≤θ≤3.0°.

2. The cutting insert according to claim 1, characterized in that When viewed from the side opposite to the rake face, The wiper edge is in a perfect circular arc shape.

3. The cutting insert according to claim 2, characterized in that The arc radius R of the wiper edge is in the range of 50 mm ≤ R < 200 mm.

4. The cutting insert according to claim 1 or 2, characterized in that The cutting edge is composed of the main cutting edge, the edge angle, the wiper edge, a linear inner cutting edge, and a second edge angle. The inner cutting edge is connected to an end of the wiper edge on the opposite side to the end connected to the cutting edge corner. The second edge angle is connected to an end of the inner cutting edge on the opposite side to the end connected to the wiper edge. An angle α formed by the main cutting edge and the inner cutting edge is in the range of 80°≤α<90°.

5. An indexable insert type rotary cutting tool, characterized in that: A cutting insert is mounted on a tool body that is rotatable around a rotation axis, and the cutting insert includes: a rake face; a seating face opposite to the rake face; a flank face connecting the rake face and the seating face; and a cutting edge formed on an intersecting ridgeline between the rake face and the flank face, the cutting edge sequentially comprising a linear main cutting edge, a cutting corner and a wiper edge, a recess being provided at an end of the main cutting edge on the side opposite to the end connected to the cutting corner, the wiper edge being formed in an arc shape and connected to the cutting corner by a tangent, and when viewed from a direction opposite to the rake face, an extension line of the main cutting edge is set as L1, a tangent line of the wiper edge perpendicular to the extension line L1 is set as L2, and a tangent line of the wiper edge passing through an end point P on the cutting corner side of the wiper edge is set as L3, an angle θ formed by the tangent line L2 and the tangent line L3 is in a range of 0.010°≤θ≤3.0°, The lowest point of the cutting insert in the direction along the rotation axis is located on the wiper edge.

6. The indexable insert type rotary cutting tool according to claim 5, characterized in that: When viewed from a direction opposite to the rake face, The wiper edge of the cutting insert is in a perfect circular arc shape.

7. The indexable insert type rotary cutting tool according to claim 6, characterized in that: The arc radius R of the wiper edge of the cutting blade is 50 mm ≤ R < 200 mm.

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