Manufacturing method of cutting insert, cutting tool, and machined product

Abstract

In the present invention, a cutting process is performed on a material being cut under a broad range of processing conditions. A first rising surface neighbors a cutting part via a first surface, the first rising surface being inclined upward in association with increasing distance from the first surface in a direction that follows a central axis, and becoming more distant from the central axis in association with increasing proximity to the trailing end of a body. A second rising surface extends toward the trailing end of the body from a second surface and is inclined upward in association with increasing distance from the second surface in the direction that follows the central axis. The trailing end of the first rising surface is closer to the trailing end of the body than is the leading end of the second rising surface in the direction that follows the central axis.

Description

[Technical field]

[0001] The present disclosure relates to a cutting insert used in cutting a workpiece, a cutting tool, and a method for manufacturing a machined product. [Background technology]

[0002] For example, the cutting insert described in Patent Document 1 is known as a cutting insert used when cutting a workpiece made of a metal material or the like. The cutting insert described in Patent Document 1 has a cutting head (cutting part) and an insert shank (main body). The cutting head has a rake face, a flank, and a cutting edge. In addition, a rising surface is located behind the rake face, and the rising surface is inclined upward in a direction along the central axis of the insert shank as it moves away from the rake face. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication "JP Patent Publication No. 2013-519537" Summary of the Invention

[0004] The cutting insert according to the present disclosure includes a rod-shaped main body extending from a front end to a rear end along a central axis, and a cutting portion protruding laterally from the front end side of the main body. The cutting portion has a triangular shape when viewed from above, and has a rake face including a corner portion protruding most laterally from the front end side of the main body, a first side portion extending from the corner portion toward the main body, and a second side portion extending from the corner portion toward the main body and located closer to the rear end of the main body than the first side portion, and a cutting edge located at least from the corner portion to the first side portion. The body has a first surface continuous with the rake surface, a first rising surface adjacent to the cutting portion via the first surface, inclined upward as it moves away from the first surface in a direction along the central axis and moving away from the central axis as it approaches a rear end of the body, a second surface adjacent to the first surface via the first rising surface and extending from the front end to the rear end of the body, and a second rising surface extending from the second surface toward the rear end of the body and inclined upward as it moves away from the second surface in a direction along the central axis. The rear end of the first rising surface is closer to the rear end of the body in the direction along the central axis than the front end of the second rising surface. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a schematic perspective view of a cutting insert according to an embodiment. [Diagram 2] 2 is a schematic perspective view of the cutting insert shown in FIG. 1, as viewed from a different direction from that in FIG. 1. [Diagram 3] FIG. 2 is a schematic plan view of the cutting insert shown in FIG. [Figure 4] FIG. 2 is a schematic side view of the cutting insert shown in FIG. [Diagram 5] FIG. 4 is an enlarged view of a portion V in FIG. [Figure 6] FIG. 5 is an enlarged view of a portion VI in FIG. [Figure 7] FIG. 6 is a cross-sectional view taken along line VII-VII in FIG. 5. [Figure 8]FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 5. [Figure 9] FIG. 6 is a cross-sectional view taken along line IX-IX in FIG. 5. [Figure 10] FIG. 1 is a schematic perspective view of a cutting tool according to an embodiment. [Figure 11] FIG. 11 is a schematic exploded perspective view of the cutting tool shown in FIG. [Figure 12] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment. [Figure 13] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment. [Figure 14] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment. [Figure 15] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Hereinafter, the cutting insert, cutting tool, and manufacturing method of the machined product according to the embodiment of the present disclosure will be described in detail with reference to the drawings. However, for the convenience of explanation, each of the drawings referred to below shows only the components necessary for explaining the embodiment in a simplified manner. Therefore, the cutting insert according to the embodiment of the present disclosure may include any components not shown in each of the drawings referred to. In addition, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of each member.

[0007] In this disclosure, the "central axis" refers to an axis along the longitudinal direction of the body, and an axis passing through the center of at least one of the front end and rear end of the body. For example, an axis along the longitudinal direction that passes through the center of gravity of the body when viewed from the rear end may be regarded as the central axis. "Lateral" refers to a direction perpendicular to a longitudinal section along the central axis of the body. "Flat" refers to a surface that is not curved at a visual level, or does not have visual irregularities. "Up-down direction" is defined based on a state in which the rake face of the cutting part faces vertically upward.

[0008] <Cutting insert> (Overall structure of cutting insert) The overall configuration of a cutting insert 10 according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 4. Fig. 1 is a schematic perspective view of the cutting insert according to the embodiment. Fig. 2 is a schematic perspective view of the cutting insert shown in Fig. 1 as viewed from a different direction from that of Fig. 1. Fig. 3 is a schematic plan view of the cutting insert shown in Fig. 1. Fig. 4 is a schematic side view of the cutting insert shown in Fig. 1.

[0009] As shown in FIGS. 1 to 4, a cutting insert 10 according to an embodiment of the present disclosure is a tool component used in cutting a workpiece W (see FIG. 12) made of a metal material or the like. The cutting insert 10 is mainly used for inner diameter cutting (inner diameter processing) of the cutting of the workpiece W. The cutting insert 10 is made of a hard material such as cemented carbide, cermet, and cBN. The cutting insert 10 has a rod-shaped main body 12, which extends from a front end 12a to a rear end 12b along a central axis L. The cutting insert 10 has a cutting part 14 that contacts the workpiece W to perform cutting, and the cutting part 14 protrudes laterally from the front end 12a of the main body 12. The main body 12 and the cutting part 14 are made of the same material, but the main body 12 and the cutting part 14 may be made of different materials and joined by a joining means such as brazing. In this case, at least the cutting portion 14 is made of a hard material such as cemented carbide, cermet, or cBN.

[0010] A flat top surface 16 is located on the upper side of the main body 12, and the top surface 16 extends in a direction along the central axis L. A flat bottom surface 18 is located on the lower side of the main body 12, and the bottom surface 18 extends in a direction along the central axis L. An inclined surface 20 is located on the rear end 12b side of the main body 12, and the inclined surface 20 is inclined in the direction along the central axis L so as to become lower as it approaches the rear end 12b of the main body 12.

[0011] (Specific configuration of cutting part) A specific configuration of the cutting portion 14 will be described with reference to Figs. 5 to 9. Fig. 5 is an enlarged view of a portion IV in Fig. 3. Fig. 6 is an enlarged view of a portion VI in Fig. 4. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 5. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 5. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 5.

[0012] As shown in Figures 5 and 6, the cutting part 14 has a rake face 22, and the rake face 16 is triangular when viewed from above. The rake face 22 includes a corner 22a that protrudes most laterally from the tip 12a side of the main body 12, and a first side portion 22b extending from the corner portion 22a toward the main body 12. The rake face 22 includes a second side portion 22c that extends from the corner portion 22a toward the main body 12, and the second side portion 22c is located closer to the rear end 12b of the main body 12 than the first side portion 22b. The rake face may be, for example, a concave curved surface, or may be a flat surface as shown in Figures 5 and 6.

[0013] The cutting portion 14 has a first cutting edge C1, which is located over the entire area from the corner 22a to the first side 22b. The cutting portion 14 has a second cutting edge C2, which is located over the entire area from the corner 22a to the second side 22c. A planar first flank 24 is located below the first cutting edge C1, and a planar second flank 26 is located below the second cutting edge C2. The first cutting edge C1 is located at the intersection ridgeline between the rake face 22 and the first flank 24, and the second cutting edge C2 is located at the intersection ridgeline between the rake face 22 and the second flank 26.

[0014] The first cutting edge C1 does not have to be located over the entire area of ​​the first side portion 22b as long as it is located over a portion of the area from the corner portion 22a to the first side portion 22b. The second cutting edge C2 does not have to be located over the entire area of ​​the second side portion 22c as long as it is located over a portion of the area from the corner portion 22a to the second side portion 22c. The first cutting edge C1 may be omitted from the cutting portion 14.

[0015] As shown in Figs. 7 to 9, the rake face 22 may be inclined downward at a first rake angle θ1 in a direction perpendicular to the central axis L as it moves away from the corner. The rake face 22 may be inclined downward at a second rake angle θ2 in a direction along the central axis as it moves closer to the rear end 12b of the main body 12. In such a case, the chips are easily guided to the side of the first rising surface 30 described below, and the flow of the chips is easily controlled. In particular, the first rake angle θ1 may be set larger than the second rake angle θ2. In such a case, the chips are easily guided to the side of the rear end 12b of the main body 12, improving the dischargeability of the chips.

[0016] (Specific configuration of main body 12) The specific configuration of the main body 12 will be described with reference to FIGS.

[0017] As shown in Figs. 5 and 7 to 9, the main body 12 has a first surface 28 that is continuous with the rake face 22, and the first surface 28 has the same function as the rake face 22. The first surface 28 may be, for example, a concave curved surface, or may be a flat surface as shown in Figs. 5 and 7 to 9. The first surface 28 being continuous with the rake face 22 means that the first surface 28 is connected to the rake face 22, and for example, there is no step between these surfaces. Here, no ridge line may be formed at the boundary between the first surface 28 and the rake face 22, and these surfaces may be smoothly connected. In this case, chips can be smoothly flowed from the rake face 22 to the first surface 28.

[0018] The first surface 28 may be inclined downward at a third rake angle θ3 in a direction perpendicular to the central axis L as it moves away from the rake face 22. The first surface 28 may be inclined downward at a fourth rake angle θ4 in a direction along the central axis L as it approaches the rear end 12b of the main body 12. In such a case, the chips are likely to be guided to the side of the first rising surface 30 described below, and the flow of the chips is likely to be controlled.

[0019] In particular, the third rake angle θ3 may be set to be larger than the fourth rake angle θ4. In the present embodiment, as an example, the third rake angle θ3 is set to the same angle as the first rake angle θ1, but may be set to a different angle. The fourth rake angle θ is set to the same angle as the second rake angle θ1, but may be set to a different angle. In such a case, the chips tend to flow toward the rear end 12b of the main body 12, improving the dischargeability of the chips.

[0020] As shown in Figures 5 and 6, the main body 12 has a first raised surface 30 adjacent to the cutting portion 14 via the first surface 28. The first raised surface 30 is inclined in a curved shape upward in a direction along the central axis L as it moves away from the first surface 28. The first raised surface 30 moves away from the central axis L as it approaches the rear end 12b of the main body 12. The first raised surface 30 functions as a chip breaker that breaks up chips. When the first raised surface 30 is away from the rake face 22, it is easy to ensure that the area of ​​the rake face 22 is sufficient.

[0021] The main body 12 has a flat second surface 32 adjacent to the first surface via the first rising surface 30. The second surface 32 extends from the front end 12a of the main body 12 toward the rear end 12b. The main body 12 also has a second rising surface 34 extending from the second surface 32 toward the rear end 12b of the main body 12. The second rising surface 34 is inclined in a curved shape upward in the direction along the central axis L as it moves away from the second surface 32. In other words, the second rising surface 34 rises as it moves away from the second surface 32. The second rising surface 34 functions as a chip breaker that breaks up chips.

[0022] The rear end 30b of the first raised surface 30 may be closer to the rear end 12b of the main body 12 than the tip 34a of the second raised surface 34 in the direction along the central axis L. In this case, the flow of chips is easily controlled by at least one of the first raised surface 30 and the second raised surface 34. Also, the rear end 34b of the second raised surface 34 may be closer to the rear end 12b of the main body 12 than the rear end 34b of the first raised surface 34 in the direction along the central axis L. In this case, the area of ​​the second raised surface 34 is easily secured. Therefore, when the cutting depth is large and the feed rate is large, the second raised surface 34 can stably process the chips.

[0023] The rear end 34b of the first rising surface 34 may be closer to the rear end 12b of the body 12 than the upper end 30u of the first rising surface 30 in the direction along the central axis L. In such a case, it is possible to prevent chips from flowing toward the cutting portion 14 on the side surface of the body 12, and to prevent deterioration of the surface accuracy of the machined surface of the workpiece W.

[0024] The body 12 has a notch 36, and the notch 36 is located on the opposite side of the cutting portion 14 on the tip 12a side of the body 12. The width of the notch 36 may be set to be larger than the width of the cutting portion 14 in the direction along the central axis L. In such a case, it is possible to improve the dischargeability of chips on the opposite side of the cutting portion 14 in the body 12 and suppress chip clogging.

[0025] As described above, the first rising surface 30 is adjacent to the cutting portion 14 via the first surface 28. Therefore, when the cutting depth is small, the first rising surface 30 can control the flow of the chips, and the chips can be processed, for example, by being cut.

[0026] As described above, the first raised surface 30 moves away from the central axis L as it approaches the rear end 12b of the main body 12. The rear end 30b of the first raised surface 30 is closer to the rear end 12b of the main body 12 than the tip 34a of the second raised surface 34. Therefore, when the cutting depth is large and the feed rate is small, the first raised surface 30 can control the flow of the chips to process them.

[0027] As described above, the rear end 30b of the first rising surface 30 is closer to the rear end 12b of the main body 12 than the tip 34a of the second rising surface 34. The rear end 34b of the second rising surface 34 is closer to the rear end 12b of the main body 12 than the rear end 34b of the first rising surface 34. This allows the first rising surface 30 and the second rising surface 34 to overlap in the direction along the central axis L, preventing the chips from flowing without contacting both the first rising surface 30 and the second rising surface 34. Therefore, when the cutting depth is large and the feed rate is large, the chips can be processed by at least one of the first rising surface 30 and the second rising surface 34. Even when the cutting depth is large and the feed rate is medium, the chips can be processed by at least one of the first rising surface 30 and the second rising surface 34.

[0028] In other words, according to the embodiment of the present disclosure, cutting of the workpiece W can be performed under a wide range of machining conditions.

[0029] <Cutting tools> A cutting tool according to an embodiment of the present disclosure will be described with reference to Figures 10 and 11. Figure 10 is a schematic perspective view of the cutting tool according to the embodiment. Figure 11 is a schematic exploded perspective view of the cutting tool shown in Figure 10.

[0030] 10 and 11, a cutting tool 38 according to an embodiment includes a rod-shaped holder 40, which extends from a front end 40a to a rear end 40b. The holder 40 is made of a metal material such as steel. The holder 40 has a hole-shaped pocket 42, which is located at the front end 40a of the holder 40. The cutting tool 38 includes a cutting insert 10 located in the pocket 42, and a body 12 is detachably attached to the pocket 42.

[0031] The holder 40 has a plurality of screw holes 44, and the plurality of screw holes 44 are located at the upper part of the holder 40. Bolts 46 are screwed into the plurality of screw holes, and the plurality of bolts 46 press the top surface 16 of the main body 12 (see FIGS. 3 and 4). The holder 40 also has a plurality of pin holes 48, and the plurality of pin holes 48 are located at the side of the holder 40. A pin 50 is located in any of the plurality of pin holes 48, and the pin 50 abuts against the inclined surface 20 of the main body 12 (see FIGS. 3 and 4). This allows the cutting insert 10 to be fixed to the holder 40 while the protruding length of the cutting insert 10 relative to the holder 40 is adjusted.

[0032] <Method of manufacturing machined products> A method for producing a machined product according to an embodiment of the present disclosure will be described with reference to Figures 11 to 14. Figures 12 to 15 are schematic diagrams for explaining a method for producing a machined product according to an embodiment.

[0033] As shown in Figs. 12 to 15, the manufacturing method of the machined product according to the embodiment is a method for manufacturing a machined product M, which is a workpiece W that has been machined, and includes a first step, a second step, and a third step. The first step is a step of rotating the workpiece W around its axis S. The second step is a step of bringing the cutting insert 10 of the cutting tool 38 into contact with the rotating workpiece W. The third step is a step of separating the cutting tool 38 from the workpiece W. The specific contents of the manufacturing method of the machined product according to the embodiment are as follows.

[0034] As shown in FIG. 12, the workpiece W is attached to a chuck (not shown) of a lathe, and the chuck is rotated to rotate the workpiece W around its axis S. Next, as shown in FIG. 13, the cutting tool 38 is moved in the direction of arrow D1 to approach the workpiece W, and the cutting portion 14 of the cutting insert 10 is brought into contact with the inner circumferential surface Wf of the machined hole of the rotating workpiece W. Then, as shown in FIG. 14, the cutting tool 38 is moved along the axis S of the workpiece W while the cutting portion 14 of the cutting insert 10 is brought into contact with the inner circumferential surface Wf of the machined hole of the workpiece W. As a result, the workpiece W is cut, and the inner circumferential surface Wf of the machined hole of the workpiece W can be finished into a machined surface.

[0035] 15, the cutting tool 38 is moved in the direction of the arrow D2 to separate the cutting tool 38 from the workpiece W. This completes the cutting of the workpiece W, and a machined product M can be manufactured, which is the workpiece W that has been machined. Since the cutting insert 10 has excellent cutting ability for the reasons described above, a machined product M with excellent machining accuracy can be manufactured.

[0036] When cutting is continued, the cutting portion 14 of the cutting insert 10 may be repeatedly brought into contact with different locations of the workpiece W while rotating the workpiece W. In this embodiment, the cutting tool 38 is brought close to the workpiece W, but since it is only necessary that the cutting tool 38 and the workpiece W are brought relatively close to each other, for example, the workpiece W may be brought close to the cutting tool 38. This also applies to the case where the cutting tool 38 is moved away from the workpiece W.

[0037] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-mentioned embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure. [Explanation of symbols]

[0038] 10 Cutting insert 12 Main unit 12a Tip 12b rear end 14 Cutting section 22 Scooping face 22a Corner 22b 1st side 22c 2nd side C1 1st cutting edge C2 2nd cutting edge 28 Page 1 30 First rising surface 30b rear end 30u top end 32 2nd page 34 Second rising surface 34b rear end 36 Notch 38 Cutting tools 40 Holder 42 Pocket L center axis W Work material Wf: Inner surface of drilled hole

Claims

1. A rod-shaped main body extending along a central axis from a front end to a rear end; A cutting portion protruding laterally from a tip side of the main body, The cutting portion is a scooping surface that is triangular in shape when viewed from above and includes a corner portion that protrudes most laterally from a tip side of the body, a first side portion that extends from the corner portion toward the body, and a second side portion that extends from the corner portion toward the body and is located closer to a rear end of the body than the first side portion; A cutting edge is located at least from the corner portion to the first side portion, The body includes: A first surface continuous with the rake surface; a first rising surface adjacent to the cutting portion via the first surface, inclining upward in a direction along the central axis as it moves away from the first surface, and moving away from the central axis as it approaches a rear end of the main body; a second surface adjacent to the first surface via the first raised surface and extending from the front end to the rear end of the main body; a second rising surface extending from the second surface toward the rear end of the main body and inclined upward as it moves away from the second surface in a direction along the central axis, a rear end of the first raised surface is closer to a rear end of the main body than a tip end of the second raised surface in a direction along the central axis, the cutting face inclines downward at a first rake angle in a direction perpendicular to the central axis as it moves away from the corner portion, and inclines downward at a second rake angle in a direction along the central axis as it approaches the rear end of the body.

2. The cutting insert according to claim 1 , wherein the first rake angle is set to be larger than the second rake angle.

3. 2. The cutting insert according to claim 1, wherein the first surface is inclined downward at a third rake angle in a direction perpendicular to the central axis as it moves away from the cutting face, and is inclined downward at a fourth rake angle in a direction along the central axis as it moves toward a rear end of the body.

4. The cutting insert according to claim 1 , wherein a rear end of the first raised surface is closer to a rear end of the main body than an upper end of the first raised surface is in a direction along the central axis.

5. A rod-shaped body extending along a central axis from a front end to a rear end, A cutting portion protruding laterally from a tip side of the main body, The cutting portion is a scooping surface that is triangular in shape when viewed from above and includes a corner portion that protrudes most laterally from a tip side of the body, a first side portion that extends from the corner portion toward the body, and a second side portion that extends from the corner portion toward the body and is located closer to a rear end of the body than the first side portion; A cutting edge is located at least from the corner portion to the first side portion, The body includes: A first surface continuous with the rake surface; a first rising surface adjacent to the cutting portion via the first surface, inclining upward in a direction along the central axis as it moves away from the first surface, and moving away from the central axis as it approaches a rear end of the main body; a second surface adjacent to the first surface via the first raised surface and extending from the front end to the rear end of the main body; a second rising surface extending from the second surface toward the rear end of the main body and inclined upward as it moves away from the second surface in a direction along the central axis, a rear end of the first raised surface is closer to a rear end of the main body than a tip end of the second raised surface in a direction along the central axis, A cutting insert, wherein a rear end of the first raised surface is closer to a rear end of the main body in a direction along the central axis than an upper end of the first raised surface.

6. The cutting insert according to claim 1 or 5, wherein a rear end of the second raised surface is closer to a rear end of the main body in a direction along the central axis than a rear end of the first raised surface.

7. The cutting insert according to claim 1 or 5, wherein the first raised surface is spaced from the rake face.

8. The cutting insert according to claim 1 or 5, wherein the body has a notch located on a tip side thereof opposite the cutting portion, and a width of the notch is set larger than a width of the cutting portion in a direction along the central axis.

9. a holder having a rod shape extending from a front end to a rear end and having a pocket located at the front end; A cutting tool comprising: a cutting insert according to claim 1 or 5 located in the pocket.

10. Rotating the workpiece; contacting the rotating workpiece with the cutting tool according to claim 9; and removing the cutting tool from the workpiece.

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