Milling tool

Abstract

A milling tool has a tool body and a plurality of cutting inserts. The tool body includes a first face, a second face, and a peripheral face. First pockets and second pockets are alternately provided on the tool body in the peripheral direction. The plurality of cutting inserts includes first cutting inserts arranged in the first pockets and second cutting inserts arranged in the second pockets. A locus of a first primary cutting edge obtained by a rotational projection of the first primary cutting edge with respect to a plane including a center axis is set as a first primary locus. A locus of a second primary cutting edge obtained by a rotational projection of the second primary cutting edge with respect to the plane is set as a second primary locus. The first primary locus and the second primary locus intersect with each other. A tangent line of the first primary locus at an intersection point of the first primary locus and the second primary locus is inclined so as to approach the center axis as it goes from the first face toward the second face. A tangent line of the second primary locus at the intersection point is inclined so as to approach the center axis as it goes from the second face toward the first face.

Description

TECHNICAL FIELD

[0001] The present application relates to a milling tool. BACKGROUND

[0002] Japanese Patent Application Publication No. H62-65108 (Patent Literature 1) describes a non-regrinding type milling tool. According to the non-regrinding type milling tool, the rotational trajectories of two main cutting edges are continuous in the axial direction.

[0003] Patent Literature 1: Japanese Patent Application Publication No. H62-65108 SUMMARY

[0004] The milling tool according to the present application is a milling tool that is rotatable about a center axis, and has a plurality of cutting inserts and a tool body that mounts the plurality of cutting inserts. The tool body includes a first face, an outer peripheral face that is continuous with the first face, and a second face that is continuous with the outer peripheral face from an opposite side of the first face in a direction along the center axis. A first pocket and a second pocket are alternately provided in a circumferential direction of the tool body. The first pocket is open at the first face and is not open at the second face. The second pocket is open at the second face and is not open at the first face. The plurality of cutting inserts include a first cutting insert that is disposed in the first pocket and a second cutting insert that is disposed in the second pocket. The first cutting insert has a first main cutting edge that is located at a position that is further outward than the outer peripheral face in a radial direction that is perpendicular to the center axis. The second cutting insert has a second main cutting edge that is located at a position that is further outward than the outer peripheral face in the radial direction. A trajectory of the first main cutting edge that is obtained by rotating the first main cutting edge with respect to a plane that includes the center axis is defined as a first main trajectory. A trajectory of the second main cutting edge that is obtained by rotating the second main cutting edge with respect to the plane is defined as a second main trajectory. The first main trajectory and the second main trajectory intersect. A tangent line of the first main trajectory at an intersection point of the first main trajectory and the second main trajectory is inclined in such a manner that the tangent line approaches the center axis as the tangent line moves from the first face toward the second face. A tangent line of the second main trajectory at the intersection point is inclined in such a manner that the tangent line approaches the center axis as the tangent line moves from the second face toward the first face. BRIEF DESCRIPTION OF DRAWINGS

[0005] Figure 1 is a perspective view that schematically shows a structure of a milling tool according to the present embodiment.

[0006] Figure 2 is a side view that schematically shows a structure of the milling tool according to the present embodiment.

[0007] Figure 3 is a perspective view that schematically shows a structure of the tool body of the milling tool according to the present embodiment. Figure 1 is an enlarged perspective view of a region III of

[0008] Figure 4 is an enlarged perspective view that schematically shows a structure of the tool body of the milling tool according to the present embodiment.

[0009] Figure 5 is a front view showing the structure of the milling tool according to the present embodiment.

[0010] Figure 6 is an enlarged view of the region VII of Figure 5 is a view showing the respective traces of the first and second cutting edges obtained by rotating projection of the first and second cutting edges with respect to the plane along the VI-VI line of

[0011] Figure 7 is an enlarged view of the region VII of Figure 6

[0012] Figure 8 is a view showing the respective traces of the first and second cutting edges obtained by rotating projection of the first and second cutting edges with respect to the plane along the VI-VI line of

[0013] Figure 9A is a perspective view showing the state of cutting of the workpiece using the conventional milling tool.

[0014] Figure 9B is a perspective view showing the state of cutting of the workpiece using the milling tool according to the present embodiment.

[0015] Figure 10 is a view showing the rotating projection trace (second main trace) of the second main cutting edge in the case where the position in the radial direction of the second main cutting edge of the milling tool according to the present embodiment is varied.

[0016] Figure 11 is a view showing the rotating projection trace (first main trace) of the first main cutting edge and the rotating projection trace (second main trace) of the second main cutting edge of the tool according to the sample 1.

[0017] Figure 12 is a view showing the rotating projection trace (first main trace) of the first main cutting edge and the rotating projection trace (second main trace) of the second main cutting edge of the tool according to the sample 2. DETAILED DESCRIPTION

[0018] [Problem to be Solved by the Invention]

[0019] An object of the present application is to provide a milling tool capable of suppressing the occurrence of steps on a machined surface.

[0020] [Effects of the Invention]

[0021] According to the present application, it is possible to provide a milling tool capable of suppressing the occurrence of steps on a machined surface.

[0022] [Explanation of Embodiments of the Invention]

[0023] ​First, an embodiment of the present application will be described.

[0024] (1) The milling tool 5 according to the present application is a milling tool 5 capable of rotating around a center axis A, having a plurality of cutting inserts 7 and a tool body 30 that mounts the plurality of cutting inserts 7. The tool body 30 includes a first face 1, an outer peripheral face 3 that is continuous with the first face 1, and a second face 2 that is continuous with the outer peripheral face 3 from an opposite side of the first face 1 in a direction along the center axis A. A first pocket 10 and a second pocket 20 are alternately provided in a circumferential direction of the tool body 30. The first pocket 10 is open at the first face 1 and is not open at the second face 2. The second pocket 20 is open at the second face 2 and is not open at the first face 1. The plurality of cutting inserts 7 include a first cutting insert 100 disposed in the first pocket 10 and a second cutting insert 200 disposed in the second pocket 20. The first cutting insert 100 has a first main cutting edge 104 located more outward than the outer peripheral face 3 in a radial direction C that is perpendicular with respect to the center axis A. The second cutting insert 200 has a second main cutting edge 204 located more outward than the outer peripheral face 3 in the radial direction. A locus of the first main cutting edge 104 obtained by rotating projection of the first main cutting edge 104 with respect to a plane including the center axis A is set as a first main locus 114. A locus of the second main cutting edge 204 obtained by rotating projection of the second main cutting edge 204 with respect to the plane is set as a second main locus 214. The first main locus 114 and the second main locus 214 intersect. A tangent line of the first main locus 114 at an intersection point 6 of the first main locus 114 and the second main locus 214 is inclined in a manner that approaches the center axis A as it goes from the first face 1 toward the second face 2. A tangent line of the second main locus 214 at the intersection point 6 is inclined in a manner that approaches the center axis A as it goes from the second face 2 toward the first face 1.

[0025] (2) The milling tool 5 according to the above (1) can have the first main cutting edge 104 having a first straight cutting edge 108 and a first corner cutting edge 101 connected to the first straight cutting edge 108. The second main cutting edge 204 can have a second straight cutting edge 208 and a second corner cutting edge 201 connected to the second straight cutting edge 208. A locus of the first straight cutting edge 108 obtained by a rotational projection of the first straight cutting edge 108 with respect to the plane can be set as a first straight locus 118. A locus of the first corner cutting edge 101 obtained by a rotational projection of the first corner cutting edge 101 with respect to the plane can be set as a first corner locus 111. A locus of the second straight cutting edge 208 obtained by a rotational projection of the second straight cutting edge 208 with respect to the plane can be set as a second straight locus 218. A locus of the second corner cutting edge 201 obtained by a rotational projection of the second corner cutting edge 201 with respect to the plane can be set as a second corner locus 211. A point of intersection of the first straight locus 118 and the first corner locus 111 can be set as a first intersection point 121. A point of intersection of the second straight locus 218 and the second corner locus 211 can be set as a second intersection point 221. The first main locus 114 can include the first straight locus 118 and the first corner locus 111. The second main locus 214 can include the second straight locus 218 and the second corner locus 211. The first straight locus 118 can intersect the second straight locus 218. In the radial direction C, the first corner locus 111 can be located more inward than the second straight locus 218. In the radial direction C, the second corner locus 211 can be located more inward than the first straight locus 118. In the radial direction, a distance between the second straight locus 218 and the first intersection point 121 can be 0.01 mm or more. In the radial direction C, a distance between the first straight locus 118 and the second intersection point 221 can be 0.01 mm or more.

[0026] (3) The milling tool 5 according to the above (1) or (2) can have, in the radial direction C, a first outermost point 122 located at an outermost circumference of the first main locus 114. In the radial direction C, the milling tool 5 can have a second outermost point 222 located at an outermost circumference of the second main locus 214. In a direction parallel to the central axis A, the intersection point 6 can be located between the first outermost point 122 and the second outermost point 222.

[0027] (4) The milling tool 5 according to the above (3) can have, in the radial direction C, a distance between the first outermost point 122 and the intersection point 6 of 0.1 mm or less. In the radial direction C, the milling tool 5 can have a distance between the second outermost point 222 and the intersection point 6 of 0.1 mm or less.

[0028] [Details of Embodiments of the Invention]

[0029] Next, the detailed contents of the embodiments of the present application will be described with reference to the drawings. In the following drawings, the same reference numerals are applied to the same or equivalent portions, and repeated description will not be given.

[0030] First, the structure of the milling tool according to the present embodiment will be described.

[0031] Figure 1 is a perspective view showing the structure of the milling tool 5 according to the present embodiment. Figure 2 is a side view showing the structure of the milling tool 5 according to the present embodiment. As shown in Figure 1 and Figure 2 The milling tool 5 according to the present embodiment is a side milling cutter capable of rotating around the center axis A. The milling tool 5 according to the present embodiment mainly has a plurality of cutting inserts 7, a tool body 30, a first fastening member 15, and a second fastening member 25. The plurality of cutting inserts 7 are attached to the tool body 30, respectively.

[0032] The tool body 30 has a first face 1, a second face 2, an outer peripheral face 3, and an inner peripheral face 4. The second face 2 is on the opposite side of the first face 1 in the direction along the center axis A. The outer peripheral face 3 is connected to each of the first face 1 and the second face 2. The second face 2 is connected to the outer peripheral face 3 from the opposite side of the first face 1 in the direction along the center axis A. In the radial direction C, the inner peripheral face 4 is on the inner side of the outer peripheral face 3. The inner peripheral face 4 is connected to each of the first face 1 and the second face 2. In the region of the tool body 30 surrounded by the inner peripheral face 4, for example, a main shaft (not shown) of a rotary drive device is arranged. In the present specification, the direction from the second face 2 toward the first face 1 will be referred to as a first direction Al, and the direction from the first face 1 toward the second face 2 will be referred to as a second direction A2. The radial direction C is a direction perpendicular to the center axis A.

[0033] As shown in Figure 2 The plurality of cutting inserts 7 have a first cutting insert 100 and a second cutting insert 200. In the direction parallel to the center axis A, a part of the first cutting insert 100 protrudes from the first face 1 toward the first direction Al. In the direction parallel to the center axis A, the first cutting insert 100 is positioned on the first direction Al side more than the second cutting insert 200.

[0034] As shown in Figure 2 In the direction parallel to the center axis A, a part of the second cutting insert 200 protrudes from the second face 2 toward the second direction A2. In the direction parallel to the center axis A, the second cutting insert 200 is positioned on the second direction A2 side more than the first cutting insert 100. Each of the first cutting insert 100 and the second cutting insert 200 is arranged on the outer peripheral face 3 of the tool body 30.

[0035] The first fastening member 15 and the second fastening member 25 are each, for example, a socket head screw. The first fastening member 15 fixes the first cutting insert 100 to the shank 30. The second fastening member 25 fixes the second cutting insert 200 to the shank 30. The first fastening member 15 and the second fastening member 25 are each disposed on the outer peripheral surface 3 of the shank 30. The first fastening member 15 and the second fastening member 25 are alternately disposed in the circumferential direction of the outer peripheral surface 3.

[0036] As shown in FIG. 1, the first fastening member 15 is disposed between the first surface 1 and the second surface 2 in the direction parallel to the central axis A. The first fastening member 15 can be disposed between the first surface 1 and the second fastening member 25 in the direction parallel to the central axis A. The first fastening member 15 is disposed on the first direction Al side more than the second fastening member 25 in the direction parallel to the central axis A. Figure 2

[0037] As shown in FIG. 2, the second fastening member 25 is disposed between the first surface 1 and the second surface 2 in the direction parallel to the central axis A. The second fastening member 25 can be disposed between the second surface 2 and the first fastening member 15 in the direction parallel to the central axis A. The second fastening member 25 is disposed on the second direction A2 side more than the first fastening member 15 in the direction parallel to the central axis A. Figure 2

[0038] Figure 3 is an enlarged oblique view of the region III shown in FIG. 3. Figure 1 is an enlarged oblique view of the structure of the shank 30 of the milling tool 5 to which the present embodiment is applied. Figure 4 The region shown in FIG. 4 corresponds to the region shown in FIG. 3. As shown in FIG. 4, the first recess 10 and the second recess 20 are provided on the outer peripheral surface 3 of the shank 30. The first recess 10 and the second recess 20 are alternately provided in the circumferential direction of the outer peripheral surface 3. Figure 4 Figure 3 As shown in FIG. 5, the first recess 10 is open at the first surface 1 and is not open at the second surface 2. The first recess 10 is defined by, for example, a first seat surface 11, a first side surface 12, and a first wall surface 13. The first seat surface 11 can also be continuous with the first surface 1. The first seat surface 11 is separated from the second surface 2. The first fastening hole 16 is provided in the first seat surface 11. Figure 3 Figure 4 As shown in FIG. 6, the second recess 20 is open at the second surface 2 and is not open at the first surface 1. The second recess 20 is defined by, for example, a second seat surface 21, a second side surface 22, and a second wall surface 23. The second seat surface 21 can also be continuous with the second surface 2. The second seat surface 21 is separated from the first surface 1. The second fastening hole 26 is provided in the second seat surface 21.

[0039] As shown in FIG. 7, the first recess 10 is open at the first surface 1 and is not open at the second surface 2. The first recess 10 is defined by, for example, a first seat surface 11, a first side surface 12, and a first wall surface 13. The first seat surface 11 can also be continuous with the first surface 1. The first seat surface 11 is separated from the second surface 2. The first fastening hole 16 is provided in the first seat surface 11. Figure 4

[0040] ​​​​​In a direction parallel to the central axis A, the first side surface 12 is located between the second side surface 2 and the first base surface 11. The first side surface 12 is separate from both the first side surface 1 and the second side surface 2. The first side surface 12 may also be connected to the outer peripheral surface 3. The first wall surface 13 is located behind the first base surface 11 in the direction of rotation. The first wall surface 13 may also be connected to the outer peripheral surface 3. The first wall surface 13 may also be connected to the first side surface 1. The first wall surface 13 is separate from the second side surface 2.

[0041] like Figure 4 As shown, the second recess 20 has an opening on the second surface 2 and no opening on the first surface 1. The second recess 20 is defined, for example, by the second seat surface 21, the second side surface 22, and the second wall surface 23. The second seat surface 21 can be connected to the second surface 2. The second seat surface 21 is separate from the first surface 1. A second fastening hole 26 is provided on the second seat surface 21.

[0042] In a direction parallel to the central axis A, the second side surface 22 is located between the first surface 1 and the second base surface 21. The second side surface 22 is separate from both the first surface 1 and the second surface 2. The second side surface 22 can be connected to the outer peripheral surface 3. The second wall surface 23 is located behind the second base surface 21 in the direction of rotation. The second wall surface 23 can be connected to the outer peripheral surface 3. The second wall surface 23 can be connected to the second surface 2. The second wall surface 23 is separate from the first surface 1.

[0043] like Figure 3 As shown, the first cutting insert 100 is disposed in the first recess 10. The first cutting insert 100 has a first top surface 105, a first bottom surface 106, and a first outer peripheral surface 107. The first bottom surface 106 is located on the opposite side of the first top surface 105. The first outer peripheral surface 107 is connected to both the first top surface 105 and the first bottom surface 106. The first top surface 105 can also function as a forward-curving surface. The first outer peripheral surface 107 can function as a clearance surface. A first through hole 120 is provided on the first outer peripheral surface 107. A first fastening member 15 passes through the first through hole 120 and is fastened to the first fastening hole 16.

[0044] The first cutting insert 100 has a first cutting edge 109. The first cutting edge 109 is formed by the edges of a first top surface 105 and a first outer peripheral surface 107. The first cutting edge 109 has a first primary cutting edge 104 and a first secondary cutting edge 103. The first secondary cutting edge 103 is connected to the first primary cutting edge 104. The first primary cutting edge 104 is located radially C further outward than the outer peripheral surface 3. From another viewpoint, the first primary cutting edge 104 protrudes radially C further outward than the outer peripheral surface 3. The first primary cutting edge 104 is essentially a cutting edge that facilitates the cutting of the material being cut.

[0045] The first primary cutting edge 104 may have a first straight cutting edge 108, a first angled cutting edge 101, and a third angled cutting edge 102. The first angled cutting edge 101 is connected to the first straight cutting edge 108. The third angled cutting edge 102 is connected to the first straight cutting edge 108. In a direction parallel to the central axis A, the first straight cutting edge 108 is located between the first angled cutting edge 101 and the third angled cutting edge 102. Relative to the first straight cutting edge 108, the first angled cutting edge 101 is located on the opposite side of the third angled cutting edge 102. In a direction parallel to the central axis A, the first angled cutting edge 101 is located between the second face 2 and the first straight cutting edge 108. The third angled cutting edge 102 is located further towards the first direction A1 than the first straight cutting edge 108. The third angled cutting edge 102 is connected to the first secondary cutting edge 103.

[0046] like Figure 3 As shown, the second cutting insert 200 is disposed in the second recess 20. The second cutting insert 200 has a second top surface 205, a second bottom surface 206, and a second outer peripheral surface 207. The second bottom surface 206 is located on the opposite side of the second top surface 205. The second outer peripheral surface 207 is connected to both the second top surface 205 and the second bottom surface 206. The second top surface 205 can function as a forward-tilting surface. The second outer peripheral surface 207 can function as a clearance surface. A second through hole 220 is provided on the second outer peripheral surface 207. A second fastening member 25 passes through the second through hole 220 and is fastened to the second fastening hole 26.

[0047] The second cutting insert 200 has a second cutting edge 209. The second cutting edge 209 is formed by the edges of the second top surface 205 and the second outer peripheral surface 207. The second cutting edge 209 has a second primary cutting edge 204 and a second secondary cutting edge 203. The second secondary cutting edge 203 is connected to the second primary cutting edge 204. The second primary cutting edge 204 is located radially C further outward than the outer peripheral surface 3. From another viewpoint, the second primary cutting edge 204 protrudes radially C further outward than the outer peripheral surface 3. The second primary cutting edge 204 is a cutting edge that substantially aids in the cutting of the material being cut.

[0048] The second primary cutting edge 204 may have a second straight cutting edge 208, a second angled cutting edge 201, and a fourth angled cutting edge 202. The second angled cutting edge 201 is connected to the second straight cutting edge 208. The fourth angled cutting edge 202 is connected to the second straight cutting edge 208. In a direction parallel to the central axis A, the second straight cutting edge 208 is located between the second angled cutting edge 201 and the fourth angled cutting edge 202. Relative to the second straight cutting edge 208, the second angled cutting edge 201 is located on the opposite side of the fourth angled cutting edge 202. In a direction parallel to the central axis A, the second angled cutting edge 201 is located between the first face 1 and the second straight cutting edge 208. The fourth angled cutting edge 202 is located further towards the second direction A2 than the second straight cutting edge 208. The fourth angled cutting edge 202 is connected to the second secondary cutting edge 203.

[0049] Figure 5 This is a front view showing the structure of the milling tool 5 according to this embodiment. (As shown...) Figure 5 As shown, the first cutting insert 100 and the second cutting insert 200 are alternately arranged circumferentially on the outer peripheral surface 3. According to the milling tool 5 of this embodiment, the number of the first cutting insert 100 is, for example, 6. The number of the second cutting insert 200 is, for example, 6. The number of the first cutting insert 100 is the same as the number of the second cutting insert 200. The number of each of the first cutting insert 100 and the second cutting insert 200 can be 6 or more. The number of each of the first cutting insert 100 and the second cutting insert 200 is not particularly limited; for example, it can be 8, 10, or 12.

[0050] like Figure 5 As shown, the first cutting insert 100 can be arranged at equal intervals in the circumferential direction. Similarly, the second cutting insert 200 can be arranged at equal intervals in the circumferential direction. In the circumferential direction, the distance between the first cutting insert 100 and the second cutting insert 200 can be constant. From another perspective, in the rotational direction, the interval between the first cutting insert 100 and the second cutting insert 200 located in front of the first cutting insert 100 in the rotational direction can be the same as the interval between the first cutting insert 100 and the second cutting insert 200 located behind the first cutting insert 100 in the rotational direction.

[0051] Figure 6 This is a schematic diagram showing the trajectories of the first cutting edge 109 and the second cutting edge 209 obtained by rotating and projecting them relative to plane B along line VI-VI. Plane B along line VI-VI is plane B that includes the central axis A. Figure 7 yes Figure 6 An enlarged schematic diagram of region VII.

[0052] like Figure 6 and Figure 7 As shown, the first cutting edge trajectory 119 is the trajectory of the first cutting edge 109 obtained by rotating and projecting it relative to the plane B containing the central axis A. The first cutting edge trajectory 119 is represented by a dashed line. The second cutting edge trajectory 219 is the trajectory of the second cutting edge 209 obtained by rotating and projecting it relative to the plane B containing the central axis A. The second cutting edge trajectory 219 is represented by a solid line.

[0053] like Figure 7As shown, the first cutting edge trajectory 119 has a first main trajectory 114 and a first secondary trajectory 113. The first main trajectory 114 is the trajectory of the first main cutting edge 104 obtained by rotating and projecting it relative to a plane B containing the central axis A. The first secondary trajectory 113 is the trajectory of the first secondary cutting edge 103 obtained by rotating and projecting it relative to a plane B containing the central axis A. The first secondary trajectory 113 is connected to the first main trajectory 114.

[0054] like Figure 7 As shown, the second cutting edge trajectory 219 has a second main trajectory 214 and a second secondary trajectory 213. The second main trajectory 214 is the trajectory of the second main cutting edge 204 obtained by rotating and projecting it relative to the plane B containing the central axis A. The second secondary trajectory 213 is the trajectory of the second secondary cutting edge 203 obtained by rotating and projecting it relative to the plane B containing the central axis A. The second secondary trajectory 213 is connected to the second main trajectory 214.

[0055] The third trajectory 300 is the trajectory of the blade 30 obtained by rotating and projecting it relative to a plane B containing the central axis A. The third trajectory 300 has an outer peripheral trajectory 303, a first trajectory 301, and a second trajectory 302. The outer peripheral trajectory 303 is the trajectory of the outer peripheral surface 3 obtained by rotating and projecting it relative to a plane B containing the central axis A. The first trajectory 301 is the trajectory of the first surface 1 obtained by rotating and projecting it relative to a plane B containing the central axis A. The second trajectory 302 is the trajectory of the second surface 2 obtained by rotating and projecting it relative to a plane B containing the central axis A. The outer peripheral trajectory 303 is connected to both the first trajectory 301 and the second trajectory 302.

[0056] In the radial direction C, the first primary trajectory 114 and the second primary trajectory 214 are each located further outward than the outer peripheral trajectory 303. In the direction parallel to the central axis A, the first secondary trajectory 113 can be located further towards the first direction A1 than the first trajectory 301. In the direction parallel to the central axis A, the second secondary trajectory 213 can be located further towards the second direction A2 than the second trajectory 302.

[0057] Figure 8 This is a schematic diagram representing the first main trajectory 114 and the second main trajectory 214. Figure 8 In this model, the scale for radial direction C is made significantly larger than the scale for the direction parallel to the central axis A. In radial direction C, the direction away from the central axis A is defined as the outer side. In radial direction C, the direction approaching the central axis A is defined as the inner side.

[0058] like Figure 8As shown, the first main trajectory 114 has a first straight trajectory 118, a first angular trajectory 111, and a third angular trajectory 112. The first straight trajectory 118 is the trajectory of the first straight cutting edge 108 obtained by rotating and projecting it relative to the plane B containing the central axis A. The first angular trajectory 111 is the trajectory of the first angular cutting edge 101 obtained by rotating and projecting it relative to the plane B containing the central axis A. The third angular trajectory 112 is the trajectory of the third angular cutting edge 102 obtained by rotating and projecting it relative to the plane B containing the central axis A. The point of tangency between the first straight trajectory 118 and the first angular trajectory 111 is the first tangency point 121.

[0059] like Figure 8 As shown, the second main trajectory 214 has a second straight trajectory 218, a second angle trajectory 211, and a fourth angle trajectory 212. The second straight trajectory 218 is the trajectory of the second straight cutting edge 208 obtained by rotating and projecting it relative to the plane B containing the central axis A. The second angle trajectory 211 is the trajectory of the second angle cutting edge 201 obtained by rotating and projecting it relative to the plane B containing the central axis A. The fourth angle trajectory 212 is the trajectory of the fourth angle cutting edge 202 obtained by rotating and projecting it relative to the plane B containing the central axis A. The point of tangency between the second straight trajectory 218 and the second angle trajectory 211 is the second tangency point 221.

[0060] like Figure 8 As shown, the first main trajectory 114 intersects with the second main trajectory 214. Specifically, the first straight trajectory 118 intersects with the second straight trajectory 218. The intersection point 6 of the first main trajectory 114 and the second main trajectory 214 can be located at the midpoint between the first surface 1 and the second surface 2. The portion of the second straight trajectory 218 located further towards the second direction A2 than the intersection point 6 can be located radially C, further outward than the first angular trajectory 111. The portion of the first straight trajectory 118 located further towards the first direction A1 than the intersection point 6 can be located radially C, further outward than the second angular trajectory 211.

[0061] The tangent line (first tangent L1) of the first principal trajectory 114 at the intersection point 6 of the first principal trajectory 114 and the second principal trajectory 214 is inclined in a manner that it approaches the central axis A as it moves from the first surface 1 toward the second surface 2. In the radial direction C, the first angular trajectory 111 is located further inside than the first straight trajectory 118. In the radial direction C, the third angular trajectory 112 is located further outside than the first angular trajectory 111. The distance between the first straight trajectory 118 and the central axis A decreases as it moves from the first surface 1 toward the second surface 2.

[0062] The tangent line (second tangent L2) of the second principal trajectory 214 at the intersection point 6 of the first principal trajectory 114 and the second principal trajectory 214 is inclined in a manner that it approaches the central axis A as it moves from the second surface 2 toward the first surface 1. In the radial direction C, the second angular trajectory 211 is located further inside than the second straight trajectory 218. In the radial direction C, the fourth angular trajectory 212 is located further outside than the second angular trajectory 211. The distance between the second straight trajectory 218 and the central axis A decreases as it moves from the second surface 2 toward the first surface 1.

[0063] like Figure 8 As shown, in the radial direction C, the second angular trajectory 211 is located further inside than the first straight trajectory 118. In the radial direction C, the distance between the first straight trajectory 118 and the second tangent point 221 (the first distance E1) can, for example, be 0.01 mm or more. The lower limit of the first distance E1 is not particularly limited; for example, it can be 0.012 mm or more, or 0.014 mm or more. The upper limit of the first distance E1 is not particularly limited; for example, it can be less than 0.02 mm, or less than 0.018 mm.

[0064] like Figure 8 As shown, in the radial direction C, the first angular trajectory 111 is located further inside than the second straight trajectory 218. In the radial direction C, the distance between the second straight trajectory 218 and the first tangent point 121 (the second distance E2) can, for example, be 0.01 mm or more. The lower limit of the second distance E2 is not particularly limited; for example, it can be 0.012 mm or more, or 0.014 mm or more. The upper limit of the first distance E1 is not particularly limited; for example, it can be less than 0.02 mm, or less than 0.018 mm.

[0065] In the radial direction C, the point located at the outermost periphery of the first main trajectory 114 is designated as the first outermost point 122. In the radial direction C, the point located at the outermost periphery of the second main trajectory 214 is designated as the second outermost point 222. In the direction parallel to the central axis A, the intersection point 6 of the first main trajectory 114 and the second main trajectory 214 lies between the first outermost point 122 and the second outermost point 222. In the direction parallel to the central axis A, the intersection point 6 of the first main trajectory 114 and the second main trajectory 214 lies between the first tangent point 121 and the second tangent point 221.

[0066] like Figure 8As shown in the radial direction C, the distance (a third distance E3) between the first outermost point 122 and the intersection 6 of the first main trajectory 114 and the second main trajectory 214 can be, for example, 0.1 mm or less. The upper limit of the third distance E3 is not particularly limited, and can be, for example, 0.08 mm or less, or 0.06 mm or less. The lower limit of the third distance E3 is not particularly limited, and can be, for example, 0.02 mm or more, or 0.04 mm or more. The first outermost point 122 can be, for example, the point of intersection of the first straight trajectory 118 and the third angular trajectory 112.

[0067] As shown in the radial direction C, the distance (a third distance E3) between the first outermost point 122 and the intersection 6 of the first main trajectory 114 and the second main trajectory 214 can be, for example, 0.1 mm or less. The upper limit of the third distance E3 is not particularly limited, and can be, for example, 0.08 mm or less, or 0.06 mm or less. The lower limit of the third distance E3 is not particularly limited, and can be, for example, 0.02 mm or more, or 0.04 mm or more. The first outermost point 122 can be, for example, the point of intersection of the first straight trajectory 118 and the third angular trajectory 112. Figure 8 As shown in the radial direction C, the distance (a fourth distance E4) between the second outermost point 222 and the intersection 6 of the first main trajectory 114 and the second main trajectory 214 can be, for example, 0.1 mm or less. The upper limit of the fourth distance E4 is not particularly limited, and can be, for example, 0.08 mm or less, or 0.06 mm or less. The lower limit of the fourth distance E4 is not particularly limited, and can be, for example, 0.02 mm or more, or 0.04 mm or more. The second outermost point 222 can be, for example, the point of intersection of the second straight trajectory 218 and the fourth angular trajectory 212. As shown in the radial direction C, the distance (a fourth distance E4) between the second outermost point 222 and the intersection 6 of the first main trajectory 114 and the second main trajectory 214 can be, for example, 0.1 mm or less. The upper limit of the fourth distance E4 is not particularly limited, and can be, for example, 0.08 mm or less, or 0.06 mm or less. The lower limit of the fourth distance E4 is not particularly limited, and can be, for example, 0.02 mm or more, or 0.04 mm or more. The second outermost point 222 can be, for example, the point of intersection of the second straight trajectory 218 and the fourth angular trajectory 212.

[0068] The first imaginary straight line X1 is a straight line passing through the first outermost point 122 and parallel to the central axis A. The first imaginary straight line X1 can pass through the second outermost point 222. The second imaginary straight line X2 is a straight line passing through the intersection 6 of the first main trajectory 114 and the second main trajectory 214 and parallel to the central axis A. The angle (a first angle Θ1) of the first straight trajectory 118 with respect to the second imaginary straight line X2 can be, for example, 0.2° or more and 0.6° or less. Likewise, the angle (a second angle Θ2) of the second straight trajectory 218 with respect to the second imaginary straight line X2 can be, for example, 0.2° or more and 0.6° or less. The distance (a fifth distance D) between the intersection 6 of the first main trajectory 114 and the second main trajectory 214 and the first imaginary straight line X1 in the radial direction C can be the same as the third distance E3. The fifth distance D can be the same as the fourth distance E4. The third distance E3 can be the same as or different from the fourth distance E4.

[0069] The first main trajectory 114 shown can be obtained by adjusting the arrangement of the first main cutting edge 104 of the first cutting insert 100. Specifically, the first cutting insert 100 can be arranged in the first pocket 10 in such a manner that the first main cutting edge 104 coincides with the first main trajectory 114 when viewed in the circumferential direction. Likewise, the second main trajectory 214 can be obtained by adjusting the arrangement of the second main cutting edge 204 of the second cutting insert 200. The first main trajectory 114 shown can be obtained by adjusting the arrangement of the first main cutting edge 104 of the first cutting insert 100. Specifically, the first cutting insert 100 can be arranged in the first pocket 10 in such a manner that the first main cutting edge 104 coincides with the first main trajectory 114 when viewed in the circumferential direction. Likewise, the second main trajectory 214 can be obtained by adjusting the arrangement of the second main cutting edge 204 of the second cutting insert 200.

[0070] The first main trajectory 114 shown can be obtained by adjusting the arrangement of the first main cutting edge 104 of the first cutting insert 100. Specifically, the first cutting insert 100 can be arranged in the first pocket 10 in such a manner that the first main cutting edge 104 coincides with the first main trajectory 114 when viewed in the circumferential direction. Likewise, the second main trajectory 214 can be obtained by adjusting the arrangement of the second main cutting edge 204 of the second cutting insert 200. Figure 8 The first main trajectory 114 shown can be obtained by adjusting the arrangement of the first main cutting edge 104 of the first cutting insert 100. Specifically, the first cutting insert 100 can be arranged in the first pocket 10 in such a manner that the first main cutting edge 104 coincides with the first main trajectory 114 when viewed in the circumferential direction. Likewise, the second main trajectory 214 can be obtained by adjusting the arrangement of the second main cutting edge 204 of the second cutting insert 200. Figure 8The 2nd principal trajectory 214 shown can be obtained by adjusting the configuration of the 2nd main cutting edge 204 of the 2nd cutting insert 200. Specifically, the 2nd cutting insert 200 can be configured to the 2nd pocket 20 in such a manner that the 2nd main cutting edge 204 coincides with the 2nd principal trajectory 214 when viewed in the circumferential direction.

[0071] Next, the measurement method of the rotational projection trajectory of each of the 1st cutting edge 109 and the 2nd cutting edge 209 will be described.

[0072] The rotational projection trajectory of each of the 1st cutting edge 109 and the 2nd cutting edge 209 can be measured using a tool presetter made by ZOLLER. The tool presetter is a tailstock tool measuring machine (Model: Phoenix 600). First, a tool in which the 1st cutting insert 100 is configured to all of the 1st pockets 10 and the 2nd cutting insert 200 is configured to all of the 2nd pockets 20 is set to the tailstock tool measuring machine. Next, the rotational projection trajectory of the outline of the cutting edge of the cutting insert that becomes the largest in each direction of the direction along the center axis A and the radial direction C is extracted using a measurement program of the tailstock tool measuring machine. The measurement program is set to Lasso function (program No. 80). The measurement mode is set to CRIS 360°. The trajectory of the cutting edge extracted using the measurement program is output as DXF data. The measurement accuracy is 0.001 mm (3 places after the decimal point).

[0073] Next, the analysis method of the rotational projection trajectory of each of the 1st cutting edge 109 and the 2nd cutting edge 209 will be described. The DXF data output from the above measurement program is analyzed using a 2-dimensional CAD software made by AUTODESK. The 2-dimensional CAD software is set to AutoCAD Mechanical 2020. The 1st distance E1, the 2nd distance E2, the 3rd distance E3, the 4th distance E4, and the 5th distance D, and the like are measured by a dimension input command. The measurement accuracy is 0.001 mm (3 places after the decimal point).

[0074] Next, the cutting method of the workpiece will be described.

[0075] Figure 9A is an oblique view schematic diagram showing a state in which the existing milling tool 5 designed with the 1st linear trajectory 118 and the 2nd linear trajectory 218 substantially in parallel and the 1st linear trajectory 118 and the 2nd linear trajectory 218 overlapping as targets is cutting the workpiece 50. Figure 9A is a view for explaining the state of the workpiece 50 in comparison with the milling tool 5 related to the present embodiment. As shown in Figure 9AAs shown, the milling tool 5, that is, the tool rotates around the center axis A in the rotational direction R while moving in the feed direction F. The milling tool 5 rotates around the center axis A, whereby the first cutting insert 100 and the second cutting insert 200 alternately cut the work material 50. Thereby, the groove 53 is formed in the work material 50. The groove 53 is defined by the bottom surface portion 51 and the side surface portion 52. In the bottom surface portion 51 of the groove 53, a step 54 is sometimes formed. The step 54 is generated due to a slight deviation of the first straight line locus 118 and the second straight line locus 218 in the radial direction C. The deviation is not intentionally designed, but is generated due to manufacturing fluctuations. The step 54 is formed in the vicinity of the junction of the portion cut by the first cutting insert 100 and the portion cut by the second cutting insert 200. Figure 9A The depth of the groove 53 in the horizontal direction is different on the upper side and the lower side of the step 54. Figure 9A The depth of the groove 53 in the horizontal direction is different on the upper side and the lower side of the step 54.

[0076] Figure 9B is a perspective view showing a state in which the work material 50 is being cut using the milling tool 5 according to the present embodiment. As shown, the milling tool 5, that is, the tool rotates around the center axis A in the rotational direction R while moving in the feed direction F. The milling tool 5 rotates around the center axis A, whereby the first cutting insert 100 and the second cutting insert 200 alternately cut the work material 50. Thereby, the groove 53 is formed in the work material 50. The groove 53 is defined by the bottom surface portion 51 and the side surface portion 52. In the bottom surface portion 51 of the groove 53, a step 54 is sometimes formed. The step 54 is generated due to a slight deviation of the first straight line locus 118 and the second straight line locus 218 in the radial direction C. The deviation is not intentionally designed, but is generated due to manufacturing fluctuations. The step 54 is formed in the vicinity of the junction of the portion cut by the first cutting insert 100 and the portion cut by the second cutting insert 200. Figure 9B The depth of the groove 53 in the horizontal direction is different on the upper side and the lower side of the step 54. Figure 9B The depth of the groove 53 in the horizontal direction is different on the upper side and the lower side of the step 54.

[0077] Next, the effects of the milling tool 5 according to the above-described embodiment will be described.

[0078] As shown, the milling tool 5, that is, the tool rotates around the center axis A in the rotational direction R while moving in the feed direction F. The milling tool 5 rotates around the center axis A, whereby the first cutting insert 100 and the second cutting insert 200 alternately cut the work material 50. Thereby, the groove 53 is formed in the work material 50. The groove 53 is defined by the bottom surface portion 51 and the side surface portion 52. In the bottom surface portion 51 of the groove 53, a step 54 is sometimes formed. The step 54 is generated due to a slight deviation of the first straight line locus 118 and the second straight line locus 218 in the radial direction C. The deviation is not intentionally designed, but is generated due to manufacturing fluctuations. The step 54 is formed in the vicinity of the junction of the portion cut by the first cutting insert 100 and the portion cut by the second cutting insert 200. Figure 9A The depth of the groove 53 in the horizontal direction is different on the upper side and the lower side of the step 54.

[0079] In the existing milling tool 5, the first main cutting edge 104 and the second main cutting edge 204 are sometimes arranged in such a manner that the rotational projection locus of the first main cutting edge 104 and the rotational projection locus of the second main cutting edge 204 are located on the same straight line, respectively. However, when the first cutting insert 100 is actually arranged in the first pocket 10 of the tool body 30, the position of the first main cutting edge 104 of the first cutting insert 100 fluctuates in the radial direction C due to fluctuations in the thickness of the first cutting insert 100 and fluctuations in the height of the first bottom surface 106 of the first pocket 10, and the like. Similarly, when the second cutting insert 200 is arranged in the second pocket 20 of the tool body 30, the position of the second main cutting edge 204 of the second cutting insert 200 fluctuates in the radial direction C due to fluctuations in the thickness of the second cutting insert 200 and fluctuations in the height of the second bottom surface 206 of the second pocket 20, and the like. Thus, the height of the bottom surface portion cut by the first main cutting edge 104 of the first cutting insert 100 is different from the height of the bottom surface portion cut by the second main cutting edge 204 of the second cutting insert 200. Therefore, a step 54 is generated in the bottom surface portion 51 of the groove 53. The step 54 is visually noticeable. Thus, even when the bottom surface portion 51 satisfies the surface roughness required by the customer, the visual aesthetic quality of the bottom surface portion 51 is reduced due to the presence of the step 54, and sometimes the customer satisfaction is reduced.

[0080] According to the milling tool 5 related to the present embodiment, if a locus of the first main cutting edge 104 obtained by rotating the first main cutting edge 104 with respect to a plane B containing the center axis A is set as a first main locus 114, and a locus of the second main cutting edge 204 obtained by rotating the second main cutting edge 204 with respect to the plane B is set as a second main locus 214, the first main locus 114 and the second main locus 214 intersect. The tangent line of the first main locus 114 at the intersection point 6 of the first main locus 114 and the second main locus 214 approaches the center axis A as it goes from the first face 1 toward the second face 2. The tangent line of the second main locus 214 at the intersection point 6 approaches the center axis A as it goes from the second face 2 toward the first face 1.

[0081] Figure 10 The rotational projection locus (second main locus 214) of the second main cutting edge 204 in the case where the position of the radial direction C of the second main cutting edge 204 fluctuates is shown for the milling tool 5 related to the present embodiment. The first state SI (dotted line) shows the second main locus 214 in the state where the position of the radial direction C of the second main cutting edge 204 does not fluctuate. The second state S2 (solid line) shows the second main locus 214 in the state where the position of the radial direction C of the second main cutting edge 204 fluctuates to the outside. As shown in the first state SI, the second main locus 214 is a straight line. As shown in the second state S2, the second main locus 214 is a curved line. Figure 10As shown, even in a case where the 2nd main cutting edge 204 is in the 2nd state S2 due to fluctuation in the position of the radial direction C of the 2nd main cutting edge 204, the 2nd point 221 of the 2nd main locus 214 is located more inward than the 1st main locus 114. Therefore, in the vicinity of the position of the 2nd point 221 of the 2nd main locus 214, the bottom surface portion 51 of the groove 53 is not cut by the 2nd main cutting edge 204, but is cut by the 1st main cutting edge 104. Therefore, even in a case where the position of the radial direction C of the 2nd main cutting edge 204 has fluctuated, the shape of the bottom surface portion 51 of the groove 53 at the position of the 2nd point 221 of the 2nd main cutting edge 204 does not change. As a result, it is possible to suppress the occurrence of the step 54 in the bottom surface portion 51 of the groove 53.

[0082] In addition, according to the milling tool 5 according to the present embodiment, in the radial direction C, the distance between the 2nd straight locus 218 and the 1st point 121 (2nd distance E2) can be 0.01 mm or more. In the radial direction C, the distance between the 1st straight locus 118 and the 2nd point 221 (1st distance E1) can be 0.01 mm or more. Thereby, it is possible to more reliably suppress the occurrence of the step 54 in the bottom surface portion 51 of the groove 53. Therefore, even in a case where the positions of the radial direction C of the 1st cutting insert 100 and the 2nd cutting insert 200 each fluctuate to some extent, it is possible to suppress the occurrence of the step 54 in the bottom surface portion 51 of the groove 53. Therefore, when the 1st cutting insert 100 and the 2nd cutting insert 200 each are attached to the tool body 30, the allowable amount of fluctuation in the position of the radial direction C of the 1st cutting insert 100 and the 2nd cutting insert 200 each is increased. As a result, it is possible to shorten the time for attaching the 1st cutting insert 100 and the 2nd cutting insert 200 each to the tool body 30.

[0083] In addition, according to the milling tool 5 according to the present embodiment, in the radial direction C, the distance between the 1st outermost point 122 and the intersection 6 (3rd distance E3) can be 0.1 mm or less. In the radial direction C, the distance between the 2nd outermost point 222 and the intersection 6 (4th distance E4) can be 0.1 mm or less. Thereby, it is possible to suppress the bottom surface portion 51 of the groove 53 from becoming excessively convex.

[0084] [Example]

[0085] (Sample Preparation)

[0086] First, a tool relating to Sample 1 and a tool relating to Sample 2 were prepared. The tool relating to Sample 1 is an example. The tool relating to Sample 2 is a comparative example. The tool relating to Sample 1 was set as the milling tool 5 according to the present embodiment. Figure 1). The blade diameter of the tool involved in Sample 1 was set to 125 mm. The blade width of the tool involved in Sample 1 was set to 19 mm. The tool involved in Sample 2 was set to an existing milling tool 5 designed so as to approximately parallel the first linear locus 118 and the second linear locus 218 and so as to overlap the first linear locus 118 and the second linear locus 218. Except for this design, the specifications of the tool involved in Sample 2 were set to be the same as those of the tool involved in Sample 1.

[0087] Figure 11 is a schematic view showing the rotational projection locus of the first main cutting edge 104 (the first main locus 114) and the rotational projection locus of the second main cutting edge 204 (the second main locus 214) of the tool involved in Sample 1. As shown in Figure 11 , the first linear locus 118 and the second linear locus 218 intersect. The first distance El is 0.033 mm. The second distance E2 is 0.019 mm. The fifth distance D is 0.036 mm.

[0088] Figure 12 is a schematic view showing the rotational projection locus of the first main cutting edge 104 (the first main locus 114) and the rotational projection locus of the second main cutting edge 204 (the second main locus 214) of the tool involved in Sample 2. As shown in Figure 12 , the first linear locus 118 does not intersect the second linear locus 218. The first distance El is 0.035 mm. The second distance E2 is 0.011 mm. The distance between the outermost point of the second cutting edge 209 locus and the intersection point of the first cutting edge 109 locus and the second cutting edge 209 locus (the sixth distance H) is 0.036 mm.

[0089] Next, each of the tools involved in Sample 1 and Sample 2 formed a groove 53 in a workpiece 50. The device was set to a vertical machining center (VM660R (BT50)) manufactured by OKK Corporation. The workpiece 50 was set to carbon steel (S50C). The cutting speed (V c ) was set to 200 m / min. The feed per tooth (f z ) was set to 0.2 mm / tooth. The axial feed amount (a p ) was set to 19 mm (blade width). The radial feed amount (a e ) was set to 8 mm. The cutting method was set to down cut. The machining method was set to dry machining.

[0090] (Measurement Conditions)

[0091] Next, the depth of the step 54 of the bottom surface portion 51 of the groove 53 formed in the machined material 50 was measured. The measurement of the depth of the step 54 was performed using a profilometer manufactured by Mitutoyo Corporation. The profilometer was set as a surface property measuring device FORM TRACER (Model: SV-C3200H4). The stylus was set as a single-angle stylus (Model: SPH-71). The software was set as FORM TRACE PAK. The measurement speed was set as 200 μm / sec. The measurement pitch was set as 2 μm.

[0092] The X-axis was arranged in a direction perpendicular to the direction in which the step 54 extends. The shape of the step 54 portion of the joint was measured in a state in which the stylus was in contact with the bottom surface portion 51 of the groove 53. The height of the step 54 was measured based on the extracted shape of the step 54. The step 54 of the bottom surface portion 51 was formed in the vicinity of the region in which the first cutting insert 100 and the second cutting insert 200 overlap in the circumferential direction. The measurement accuracy of the height of the step 54 was 0.0001 mm (4 places after the decimal point).

[0093] (Measurement Results)

[0094] [Table 1]

[0095] Step of the bottom surface portion Sample 1 Less than 0.0001 mm Sample 2 0.026 mm

[0096] Table 1 shows the measured values of the step 54 of the bottom surface portion 51 of the groove 53. As shown in Table 1, in the case where the groove 53 was formed in the machined material 50 using the tool related to Sample 1, the measured value of the step 54 formed in the bottom surface portion 51 of the groove 53 was less than 0.0001 mm. On the other hand, in the case where the groove 53 was formed in the machined material 50 using the tool related to Sample 2, the measured value of the step 54 formed in the bottom surface portion 51 of the groove 53 was 0.026 mm. According to the above results, in the case where the groove 53 was formed in the machined material 50 using the milling tool 5 related to the present embodiment, it was confirmed that the height of the step 54 of the bottom surface portion 51 of the groove 53 could be reduced.

[0097] The embodiments and examples disclosed herein are illustrative in all respects, and should not be considered as restrictive. The scope of the present application is not limited to the embodiments and examples described above, but is indicated by the claims, and includes all modifications and changes within the scope of the claims and equivalents thereof.

[0098] Explanation of Reference Numerals

[0099] 1 first surface, 2 second surface, 3 outer peripheral surface, 4 inner peripheral surface, 5 milling tool, 6 intersection point, 7 cutting insert, 10 first pocket, 11 first seating surface, 12 first side surface, 13 first wall surface, 15 first fastening member, 16 first fastening hole, 20 second pocket, 21 second seating surface, 22 second side surface, 23 second wall surface, 25 second fastening member, 26 second fastening hole, 30 blade, 50 work material, 51 bottom surface portion, 51a convex portion, 52 side surface portion, 53 groove, 54 step, 100 first cutting insert, 101 first corner cutting edge, 102 third corner cutting edge, 103 first sub cutting edge, 104 first main cutting edge, 105 first top surface, 106 first bottom surface, 107 first outer peripheral side surface, 108 first straight line cutting edge, 109 first cutting edge, 111 first corner locus, 112 third corner locus, 113 first sub locus, 114 first main locus, 118 first straight line locus, 119 first cutting edge locus, 120 first through hole, 121 first intersection point, 122 first outermost peripheral point, 200 second cutting insert, 201 second corner cutting edge, 202 fourth corner cutting edge, 203 second sub cutting edge, 204 second main cutting edge, 205 second top surface, 206 second bottom surface, 207 second outer peripheral side surface, 208 second straight line cutting edge, 209 second cutting edge, 211 second corner locus, 212 fourth corner locus, 213 second sub locus, 214 second main locus, 218 second straight line locus, 219 second cutting edge locus, 220 second through hole, 221 second intersection point, 222 second outermost peripheral point, 300 third locus, 301 first locus, 302 second locus, 303 outer peripheral locus, A center axis, A1 first direction, A2 second direction, B plane, C radial direction, D fifth distance, E1 first distance, E2 second distance, E3 third distance, E4 fourth distance, F feed direction, H sixth distance, L1 first tangent line, L2 second tangent line, R rotation direction, S1 first state, S2 second state, X1 first imaginary straight line, X2 second imaginary straight line, θ1 first angle, θ2 second angle.

Claims

1. A milling tool capable of rotating about a center axis The milling tool has: a plurality of cutting inserts; and a tool body that mounts the plurality of cutting inserts, The tool body includes a first surface, an outer peripheral surface that is continuous with the first surface, and a second surface that is continuous with the outer peripheral surface from an opposite side of the first surface in a direction along the center axis, a first pocket and a second pocket are alternately provided in the tool body in a circumferential direction, The first pocket is open at the first surface and is not open at the second surface, The second pocket is open at the second surface and is not open at the first surface, The plurality of cutting inserts includes a first cutting insert disposed in the first pocket and a second cutting insert disposed in the second pocket, The first cutting insert has a first main cutting edge located at a position further outward than the outer peripheral surface in a radial direction perpendicular to the center axis, The second cutting insert has a second main cutting edge located at a position further outward than the outer peripheral surface in the radial direction, In a case where a locus of the first main cutting edge obtained by rotating projection of the first main cutting edge with respect to a plane including the center axis is set as a first main locus, In a case where a locus of the second main cutting edge obtained by rotating projection of the second main cutting edge with respect to the plane is set as a second main locus, The first main locus intersects the second main locus, A tangent line of the first main locus at an intersection point of the first main locus and the second main locus is inclined so as to approach the center axis as it goes from the first surface toward the second surface, A tangent line of the second main locus at the intersection point is inclined so as to approach the center axis as it goes from the second surface toward the first surface, The first main cutting edge has a first straight cutting edge and a first corner cutting edge that is continuous with the first straight cutting edge, The second main cutting edge has a second straight cutting edge and a second corner cutting edge that is continuous with the second straight cutting edge, In a case where a locus of the first straight cutting edge obtained by rotating projection of the first straight cutting edge with respect to the plane is set as a first straight locus, In a case where a locus of the first corner cutting edge obtained by rotating projection of the first corner cutting edge with respect to the plane is set as a first corner locus, In a case where a locus of the second straight cutting edge obtained by rotating projection of the second straight cutting edge with respect to the plane is set as a second straight locus, In a case where a locus of the second corner cutting edge obtained by rotating projection of the second corner cutting edge with respect to the plane is set as a second corner locus, In a case where an intersection point of the first straight locus and the first corner locus is set as a first intersection point, In a case where an intersection point of the second straight locus and the second corner locus is set as a second intersection point, The first main locus includes the first straight locus and the first corner locus, The second main locus includes the second straight locus and the second corner locus, The first straight locus intersects the second straight locus, In the radial direction, the first corner locus is located further inward than the second straight locus, In the radial direction, the second corner locus is located further inward than the first straight locus, In the radial direction, a distance between the first straight line locus and the second tangent point is 0.01 mm or more, In the radial direction, a distance between the first straight line locus and the second tangent point is 0.01 mm or more.

2. The milling tool according to claim 1, wherein In the radial direction, a point located at an outermost periphery of the first main locus is set as a first outermost periphery point, In the case where a point located at an outermost periphery of the second main locus is set as a second outermost periphery point in the radial direction, In a direction parallel to the central axis, the intersection point is located between the first outermost periphery point and the second outermost periphery point.

3. The milling tool according to claim 2, wherein In the radial direction, a distance between the first outermost periphery point and the intersection point is 0.1 mm or less, In the radial direction, a distance between the second outermost periphery point and the intersection point is 0.1 mm or less.

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