Cutting insert, cutting tool, and method for producing cut workpiece

Abstract

A cutting insert according to one non-limiting aspect of the present disclosure comprises a cutting part which has a first surface, a second surface, a third surface, a cutting edge, and a through hole. The through hole has one or a plurality of openings and one or a plurality of outflow holes. A virtual region in which an outflow hole extends from an opening intersects the cutting edge in the direction along the central axis of the outflow hole.

Description

Cutting insert, cutting tool, and method for manufacturing machined product CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2024-129068, filed on August 5, 2024, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to methods of manufacturing cutting inserts, cutting tools, and machined workpieces.

[0003] Known cutting inserts (throw-away chips) are disclosed in, for example, Japanese Patent Laid-Open No. 04-183503 (Patent Document 1), International Publication No. 2021 / 074979 (Patent Document 2), and Japanese Patent Laid-Open No. 2022-046273 (Patent Document 3) as cutting tools used in cutting workpieces such as metals. The cutting insert disclosed in Patent Document 1 has a coolant supply hole formed from the side surface to the breaker surface.

[0004] In recent years, there has been a demand for improved cooling effects by coolant. In the cutting inserts described in Patent Documents 1 to 3, the coolant supply holes are not oriented toward the cutting edge of the cutting insert. Therefore, the coolant is less likely to be applied directly to the cutting edge. Therefore, there is a demand for cutting inserts with a high cooling effect by coolant.

[0005] A non-limiting one-sided cutting insert of the present disclosure includes a cutting portion having a first surface, a second surface located opposite the first surface, a third surface connected to the first surface and the second surface, a cutting edge located at an intersection of the first surface and the third surface, and a through hole opening in the first surface. The through hole has one or more openings opening in the first surface and one or more linear outflow holes extending from the openings. An imaginary area extending from the outflow hole in a direction along the central axis of the outflow hole intersects with the cutting edge.

[0006] 1 is a perspective view showing an unlimited single-sided cutting insert of the present disclosure; FIG. 2 is an enlarged view of region A1 shown in FIG. 1; FIG. 3 is a plan view of the cutting insert shown in FIG. 1 as viewed from direction B1; FIG. 4 is an enlarged view of region A2 shown in FIG. 3; FIG. 5 is an enlarged view the same as FIG. 4; FIG. 6 is an enlarged view the same as FIG. 4; FIG. 7 is an enlarged view of region A3 shown in FIG. 5; FIG. 6 is a cross-sectional view taken along line VIII-VIII in FIG. 6; FIG. 7 is a cross-sectional view taken along line IX-IX in FIG. 6; FIG. 7 is a cross-sectional view taken along line X-X in FIG. 6; FIG. 8 is a cross-sectional view of the unlimited single-sided cutting insert of the present disclosure as viewed from the same field of view as FIG. 10; FIG. 8 is a cross-sectional view of the unlimited single-sided cutting insert of the present disclosure as viewed from the same field of view as FIG. 10; FIG. 9 is a perspective view showing an unlimited single-sided cutting tool of the present disclosure; FIG. 10 is a schematic view showing one step in a method for manufacturing an unlimited single-sided machined product of the present disclosure; FIG. 11 is a schematic view showing one step in a method for manufacturing an unlimited single-sided machined product of the present disclosure; FIG. 12 is a schematic view showing one step in a method for manufacturing an unlimited single-sided machined product of the present disclosure;

[0007] <Cutting Insert> Hereinafter, a non-limiting one-sided cutting insert 1 of the present disclosure will be described in detail with reference to the drawings (hereinafter, also simply referred to as the insert 1). However, for the sake of convenience, the drawings referred to below show only the main components necessary for explaining the insert 1 of the embodiment in a simplified form. Therefore, the insert 1 of the present disclosure may include any components not shown in the drawings referred to. Furthermore, the dimensions of the components in the drawings do not faithfully represent the dimensions of the actual components and the dimensional ratios of each component. Note that the present disclosure is not limited to the following aspects.

[0008] 1 and 3, the insert 1 may include a base portion 3 and a cutting portion 5. The base portion 3 and the cutting portion 5 may be formed separately or integrally. The portion including the base portion 3 and the cutting portion 5 may be defined as a main body.

[0009] The insert 1 may have a polygonal plate shape as a whole. The insert 1 in a non-limiting example shown in Figures 1 and 4 has a generally rectangular plate shape. When the base portion 3 and the cutting portion 5 are configured as separate bodies, the base portion 3 may have a generally rectangular plate shape with some of the corners cut out. The cutting portion 5 may be joined to the cut-out portion using a brazing material or the like. As a non-limiting example shown in Figure 1, the cutting portion 5 may have a generally triangular plate shape.

[0010] The base portion 3 and the cutting portion 5 are not limited to the above configurations. For example, the base portion 3 and the cutting portion 5 may each be a rectangular plate and have the same shape when viewed from above. For example, the cutting portion 5, which is also a rectangular plate, may be located on top of the base portion 3, which is also a rectangular plate.

[0011] 1 and 4, the base portion 3 may have a first end surface 7, a second end surface 9, and a hole 11. The second end surface 9 may be located on the opposite side of the first end surface 7. The hole 11 may be located so as to penetrate from the first end surface 7 to the second end surface 9. The hole 11 can be used as an insertion hole for a fastener when fixing the insert 1 to a holder. Examples of the fastener include a screw, a clamp member, and a wedge.

[0012] 1 and 3 , the first end surface 7 is located at the upper part of the base portion 3. Therefore, the first end surface 7 may be conveniently referred to as the upper end surface 7. Also, in the non-limiting example shown in Figures 1 and 3 , the second end surface 9 is located at the lower part of the base portion 3. Therefore, the second end surface 9 may be conveniently referred to as the lower end surface 9.

[0013] 2 and 4 , the base portion 3 may have a first through hole 13. The first through hole 13 may be located inside the base portion 3. The first through hole 13 may also extend from the inside of the base portion 3 toward the cutting portion 5.

[0014] 2 , the cutting portion 5 may have a first surface 15, a second surface 17, and a third surface 19. The second surface 17 may be located opposite the first surface 15. The third surface 19 may be located between the first surface 15 and the second surface 17.

[0015] In a non-limiting example shown in Fig. 2 , the first surface 15 is located at the upper part of the cutting portion 5. Furthermore, the second surface 17 is located at the lower part of the cutting portion 5. Therefore, the first surface 15 and the second surface 17 may be conveniently referred to as the upper surface 15 and the lower surface 17, respectively. Furthermore, in a non-limiting example shown in Fig. 2 , the third surface 19 is located between the upper surface 15 and the lower surface 17 and is connected to these surfaces. Therefore, the third surface 19 may be conveniently referred to as the side surface 19.

[0016] The upper surface 15 may have any polygonal shape. As a non-limiting example shown in Fig. 5, the upper surface 15 may have a triangular shape. There is no problem if the upper surface 15 is not triangular, but is instead a square, pentagon, hexagon, or octagon.

[0017] The upper surface 15 may have a generally polygonal shape, but does not have to be a polygonal shape in the strict sense. In other words, the corners of the polygonal upper surface 15 are not limited to a configuration in which two straight lines intersect, and may have a shape with outwardly rounded corners, as in the non-limiting example shown in Figure 3. Figure 3 is a plan view of the upper surface 15 as viewed from the front. Therefore, Figure 3 may also be referred to as a top view.

[0018] 2 and 4, the cutting portion 5 may have a cutting edge 21 located at the intersection of the top surface 15 and the side surface 19. The cutting edge 21 may be used to cut a workpiece. The cutting edge 21 may be located at the entire intersection, or may be located only at a portion of the intersection.

[0019] 2 and 4 , the cutting portion 5 may have a second through hole 23. The second through hole 23 may simply be referred to as a through hole 23. The through hole 23 may be open on the upper surface 15. Furthermore, the through hole 23 may be connected to the first through hole 13 located in the base portion 3.

[0020] 2 and 4 , the upper surface 15 may have an inclined surface 25. The inclined surface 25 may be located along the cutting edge 21. Furthermore, the inclined surface 25 may be inclined away from the lower surface 17 as it moves away from the cutting edge 21. In other words, the inclined surface 25 may be inclined upward toward the inside of the upper surface 15.

[0021] The inclined surface 25 may be a flat surface or a curved surface. The inclined surface 25 may be used to collide with and curve chips during cutting. In other words, the inclined surface 25 may be used as a so-called chip breaker.

[0022] 2 and 4, the through-hole 23 may have an opening 27. The opening 27 may be open in the upper surface 15. The opening 27 may be open in the inclined surface 25 of the upper surface 15. There may be only one opening 27, or there may be multiple openings 27. When there are multiple openings 27, the number of openings 27 may be 2 to 8.

[0023] A coolant (cooling fluid) for cooling the insert 1 during cutting can be passed through the first through hole 13 and the through hole 23. The opening of the first through hole 13 in the base portion 3 can function as an inlet through which coolant flows in (is supplied) from the outside, and the opening 27 of the through hole 23 in the cutting portion 5 can function as an outlet through which the coolant flows out during cutting. In this case, the first through hole 13 in the base portion 3 and the through hole 23 in the cutting portion 5 can be collectively positioned as a coolant flow path.

[0024] Examples of coolants include water-insoluble oils and water-soluble oils. Examples of water-insoluble oils include cutting oils such as oil-based, inactive extreme pressure, and active extreme pressure types. Examples of water-soluble oils include cutting oils such as emulsions, solubles, and solutions. The coolant is not limited to a liquid, and may be a gas such as an inert gas. The coolant may be appropriately selected depending on the material of the workpiece.

[0025] The through hole 23 may have an outflow hole 29. In the non-limiting example shown in FIG. 2 , the through hole 23 is configured by a portion extending linearly, but is not limited to this. For example, the through hole 23 may be configured to have an outflow hole 29 extending linearly from the opening 27 and another portion connected to the outflow hole 29 and inclined with respect to the outflow hole 29. Here, the another portion may be linear or curved. In the non-limiting example shown in FIG. 2 , the through hole 23 is configured by a portion extending linearly, and therefore, this linearly extending portion can be evaluated as the through hole 23 and the outflow hole 29.

[0026] 2 and 4, the outflow hole 29 may extend from the opening 27. Therefore, the number of outflow holes 29 may be the same as the number of openings 27. That is, the number of outflow holes 29 may be one to match the number of openings 27, or may be multiple.

[0027] Alternatively, the outlet hole 29 may extend linearly. When the outlet hole 29 extends linearly, the coolant flowing out of the opening 27 tends to flow in the same direction as the extension of the outlet hole 29. In other words, the direction in which the coolant flows can be easily controlled by the extension direction of the outlet hole 29. Furthermore, when the outlet hole 29 is linear, the pressure loss of the coolant flowing inside the outlet hole 29 is small.

[0028] Note that the term "linear" here does not refer to a one-dimensional line, but simply refers to a state in which the hole extends straight. In the following description, the terms "linear" used for the first through-hole 13, the through-hole 23, and the outflow hole 29 have the same meaning.

[0029] In a non-limiting example shown in Figure 4 etc., the portions marked with the reference symbols 29a, 29b, and 29c respectively correspond to the outflow hole 29. Furthermore, the portions marked with the reference symbols 27a, 27b, and 27c respectively correspond to the opening 27. The portions marked with the reference symbols 21a, 21b, and 21c respectively correspond to the cutting edge 21. In a non-limiting example shown in Figure 5, the portions marked with the reference symbols L1, L2, and L3 respectively correspond to the central axis L of the outflow hole 29. In a non-limiting example shown in Figure 6, the lines VIII-VIII, IX-IX, and X-X respectively lie along the central axis L of the outflow hole 29.

[0030] 8 to 12 , a virtual area obtained by extending the outflow hole 29 from the opening 27 in a direction along the central axis L of the outflow hole 29 may be defined as area X. Area X may intersect with the cutting edge 21.

[0031] The region X may intersect with the cutting edge 21 near the upper part of the region X, or may intersect with the cutting edge 21 near the lower part of the region X.

[0032] Furthermore, region X may intersect with cutting edge 21 in any orientation. That is, region X may be oriented such that it approaches lower surface 17 as it approaches cutting edge 21, or may be oriented such that it moves away from lower surface 17 as it approaches cutting edge 21. Region X may also intersect with cutting edge 21 in an orientation parallel to lower surface 17.

[0033] When the insert 1 has the above-described configuration, the coolant injected from the outlet holes 29 is likely to directly hit the cutting edge 21. Therefore, the effect of the coolant cooling the cutting edge 21 is likely to be enhanced.

[0034] 8 to 10, a virtual line extending the central axis L of the outflow hole 29 from the opening 27 may be defined as the line K. In Figures 8 to 10, the line K in the cross section taken along line VIII-VIII in Figure 6 is defined as line K1, the line K in the cross section taken along line IX-IX is defined as line K2, and the line K in the cross section taken along line X-X is defined as line K3.

[0035] The line K may intersect with the upper surface 15. The line K may intersect with a so-called rake face of the upper surface 15 that is connected to the cutting edge 21. In other words, the line K may be located below the cutting edge 21.

[0036] When the insert 1 has the above-described configuration, the cooling effect of the coolant injected from the outlet holes 29 is likely to be enhanced. Specifically, when the line K intersects with the upper surface 15, more than half of the area X intersects with the upper surface 15. Therefore, the amount of coolant injected onto the upper surface 15 is likely to increase, and the effect of cooling the insert 1 is likely to be enhanced.

[0037] Moreover, the line K may be farther from the lower surface 17 than from the upper surface 15. The line K may be farther from the lower surface 17 than from a so-called rake face of the upper surface 15 that is connected to the cutting edge 21. In other words, the line K may be located above the rake face of the upper surface 15 and the cutting edge 21.

[0038] When the insert 1 has the above-described configuration, the chip removal effect by the coolant injected from the outlet holes 29 tends to be enhanced. Specifically, when the line K is farther from the lower surface 17 than from the upper surface 15, more than half of the region X is located above the cutting edge 21. Therefore, the coolant tends to come into contact with the chips generated by the cutting edge 21 during cutting, and the chip removal effect tends to be enhanced.

[0039] 11 , the outflow holes 29 may be parallel to the lower surface 17. That is, the area X may intersect the cutting edge 21 in an orientation parallel to the lower surface 17.

[0040] When the insert 1 has the above-described configuration, the coolant is ejected straight from the opening 27 and is likely to hit the cutting edge 21. Therefore, the cooling effect of the coolant on the cutting edge 21 is likely to be enhanced.

[0041] 8-10 , the outflow holes 29 may be inclined away from the lower surface 17 as they move away from the opening 27. That is, the region X may intersect with the cutting edge 21 in a direction that moves closer to the lower surface 17 as it approaches the cutting edge 21.

[0042] When the insert 1 has the above-described configuration, the coolant is shot down toward the cutting edge 21, and the coolant is easily hit against the cutting edge 21 while maintaining its power. Therefore, chips generated by cutting are easily blown away, and the chips are easily prevented from extending too far.

[0043] 12 , the outflow holes 29 may be inclined so as to approach the lower surface 17 as they move away from the opening 27. In other words, the region X may intersect with the cutting edge 21 in a direction that moves away from the lower surface 17 as it approaches the cutting edge 21.

[0044] When the insert 1 has the above-described configuration, the coolant is likely to come into contact with chips flowing over the upper surface 15 during cutting. Therefore, the chips flowing over the upper surface 15 are easily removed, and the chips are less likely to clog.

[0045] 2 and 4, the through-hole 23 may have a plurality of openings 27. Furthermore, the through-hole 23 may have a plurality of outlet holes 29 extending from the plurality of openings 27, respectively.

[0046] Note that "each extending" here means that one outlet hole 29 extends from one opening 27, and does not mean that multiple outlet holes 29 extend from one opening 27.

[0047] As a non-limiting example shown in FIGS. 2 and 4, the number of openings 27 and the number of outlet holes 29 may be the same.

[0048] When the insert 1 has the above-described configuration, the area through which the coolant can be injected tends to be wider than when there is only one opening 27 and one outlet hole 29. Therefore, it is easy to cool a wide area of ​​the insert 1.

[0049] 2, the top surface 15 may have a first side 31, a second side 33, and a corner portion 35. The first side 31 and the second side 33 may be connected to the corner portion 35.

[0050] Furthermore, the first side 31 and the second side 33 do not have to be straight lines in the strict sense, but may be, for example, slightly curved concave or convex curves. Note that "slightly curved" means that the radius of curvature of the curved first side 31 is sufficiently large compared to the length of the first side 31, specifically, the radius of curvature of the first side 31 is 10 times or more the length of the first side 31. The same applies to the second side 33.

[0051] 2 and 4, the cutting edge 21 may have a first cutting edge 21a, a second cutting edge 21b, and a corner cutting edge 21c. The corner cutting edge 21c may be located at a corner portion 35.

[0052] 2, the first cutting edge 21a may be located on the first side 31. The first cutting edge 21a may be connected to the corner cutting edge 21c. The first cutting edge 21a may be located on the entire first side 31, or may be located on only a portion of the first side 31.

[0053] 2, the second cutting edge 21b may be located on the second side 33. The second cutting edge 21b may be connected to the corner cutting edge 21c. The second cutting edge 21b may be located on the entire second side 33, or may be located on only a portion of the second side 33.

[0054] 2 and 4 , the opening 27 may have a first opening 27a, a second opening 27b, and a third opening 27c. The first opening 27a may be open toward the first cutting edge 21a. The second opening 27b may be open toward the second cutting edge 21b. The third opening 27c may be open toward the corner cutting edge 21c. The first opening 27a may be open toward the first cutting edge 21a on the inclined surface 25. The second opening 27b may be open toward the second cutting edge 21b on the inclined surface 25. The third opening 27c may be open toward the corner cutting edge 21c on the inclined surface 25.

[0055] 4 and 5 , the outlet holes 29 may include a first outlet hole 29a, a second outlet hole 29b, and a third outlet hole 29c. The first outlet hole 29a may extend from the first opening 27a. The second outlet hole 29b may extend from the second opening 27b. The third outlet hole 29c may extend from the third opening 27c. The first outlet hole 29a may be connected to the first opening 27a. The second outlet hole 29b may be connected to the second opening 27b. The third outlet hole 29c may be connected to the third opening 27c. Each outlet hole may extend linearly.

[0056] In addition, the state in which the first outlet hole 29a extends from the first opening 27a, the second outlet hole 29b extends from the second opening 27b, and the third outlet hole 29c extends from the third opening 27c as described above is referred to as "multiple outlet holes 'respectively extending' from multiple openings."

[0057] When the insert 1 has the above-described configuration, coolant can be easily supplied to each of the first cutting edge 21 a, the second cutting edge 21 b, and the corner cutting edge 21 c. As a result, each cutting edge can be easily cooled, and the cooling effect can be easily improved.

[0058] As shown in a non-limiting example in FIGS. 8 to 10 , the inner diameter of the first outlet hole 29a may be D1, the inner diameter of the second outlet hole 29b may be D2, and the inner diameter of the third outlet hole 29c may be D3. The inner diameter D1 of the first outlet hole 29a may be larger than the inner diameter D3 of the third outlet hole 29c. The inner diameter D2 of the second outlet hole 29b may be larger than the inner diameter D3 of the third outlet hole 29c. That is, the inner diameters D1 and D2 of the first outlet hole 29a and the second outlet hole 29b may each be larger than the inner diameter D3 of the third outlet hole 29c. The inner diameter D1 of the first outlet hole 29a may be set to approximately 0.08 to 0.15 mm. The inner diameter D2 of the second outlet hole 29b may be set to approximately 0.08 to 0.15 mm. The inner diameter D3 of the third outlet hole 29c may be set to approximately 0.03 to 0.08 mm.

[0059] When the insert 1 has the above-described configuration, more coolant is likely to be supplied to the portions used as so-called main cutting edges, such as the first cutting edge 21 a and the second cutting edge 21 b, which are therefore more efficiently cooled during cutting, which generates a lot of heat due to the large cutting resistance.

[0060] 5 , in a top view, the width from the first cutting edge 21 a to the first opening 27 a in a direction along the central axis L1 of the first outlet hole 29 a may be defined as a first length G1, the width from the second cutting edge 21 b to the second opening 27 b in a direction along the central axis L2 of the second outlet hole 29 b may be defined as a second length G2, and the width from the corner cutting edge 21 c to the third opening 27 c in a direction along the central axis L3 of the third outlet hole 29 c may be defined as a third length G3. The first length G1, the second length G2, and the third length G3 may be distances required to supply coolant from the first opening 27 a to the first cutting edge 21 a, from the second opening 27 b to the second cutting edge 21 b, and from the third opening 27 c to the corner cutting edge 21 c, respectively.

[0061] 8 to 10 and 12, a virtual plane parallel to the lower surface 17 may be used as the reference surface S (surface S). In order to set the surface S in a visually easy-to-understand position, the surface S is indicated by surface S1 in Fig. 8, surface S2 in Fig. 9, surface S3 in Fig. 10, and surface S4 in Fig. 12.

[0062] The angle that the outflow hole 29 forms with the surface S may be the inclination angle of the outflow hole 29. In other words, the angle at which the outflow hole 29 is inclined with respect to the lower surface 17 may be the inclination angle of the outflow hole 29. As in a non-limiting example shown in Figure 8, the angle that the first outflow hole 29a forms with the surface S may be the first inclination angle θ1. Similar to the first inclination angle θ1, the angle that the second outflow hole 29b forms with the surface S may be the second inclination angle θ2, and the angle that the third outflow hole 29c forms with the surface S may be the third inclination angle θ3.

[0063] Here, the angle that each outlet hole 29 makes with the surface S does not only refer to the angle formed at the point where the outlet hole 29 intersects with the surface S. If the outlet hole 29 does not intersect with the surface S, the angle formed by the intersection of the extension line (line K) of the central axis L of the outlet hole 29 and the surface S may also be the angle formed by the outlet hole 29 and the surface S.

[0064] Furthermore, the first tilt angle θ1 may be approximately 2° to 6°, the second tilt angle θ2 may be approximately 2° to 6°, and the third tilt angle θ3 may be approximately 1° to 4°. In other words, the first tilt angle θ1 and the second tilt angle θ2 may be the same as or different from the third tilt angle θ3.

[0065] When the first inclination angle θ1 and the second inclination angle θ2 are the same as the third inclination angle θ3, the behavior of the coolant flowing through each through hole is similar, making it easier to control the flow of the coolant. However, the term "same angle" does not necessarily mean "same" in the strict sense. The term "same angle" means that the difference between the angles θ1, θ2, and θ3 is less than 1°.

[0066] On the other hand, when the first inclination angle θ1 and the second inclination angle θ2 are different from the third inclination angle θ3, the coolant is more likely to be supplied in accordance with the position of each cutting edge, and the cooling effect is likely to be enhanced. Note that, as described above, "the angles are the same" does not necessarily mean "the angles are the same" in the strict sense, so "the first inclination angle θ1 and the second inclination angle θ2 are different from the third inclination angle θ3" means that the difference in angle between θ1, θ2, and θ3 is 1° or more.

[0067] When the outflow holes 29 are inclined so as to move away from the lower surface 17 as they move away from the opening 27, the first inclination angle θ1 and the second inclination angle θ2 may each be greater than the third inclination angle θ3. In this case, the first length G1 and the second length G2 may each be smaller than the third length G3.

[0068] When the outflow holes 29 are inclined so as to move away from the lower surface 17 as they move away from the openings 27, the smaller the inclination angle of the outflow holes 29, the easier it is to inject the coolant over a longer distance. Therefore, when the insert 1 has the above configuration, the coolant injected from the openings 27 is easily supplied to each cutting edge, and the cooling effect is likely to be enhanced.

[0069] When the outflow holes 29 are inclined so as to approach the lower surface 17 with increasing distance from the opening 27, the first inclination angle θ1 and the second inclination angle θ2 may each be greater than the third inclination angle θ3. In this case, the first length G1 and the second length G2 may each be smaller than the third length G3.

[0070] When the outflow holes 29 are inclined so that they approach the lower surface 17 as they move away from the openings 27, the smaller the inclination angle of the outflow holes 29, the easier it is to inject the coolant over a longer distance. Therefore, when the insert 1 has the above configuration, the coolant injected from the openings 27 is easily supplied to each cutting edge, and the cooling effect is likely to be enhanced.

[0071] As a non-limiting example shown in Fig. 8, the height from the lower surface 17 to the center of the first opening 27a may be defined as the first height H1. As a non-limiting example shown in Fig. 9, the height from the lower surface 17 to the center of the second opening 27b may be defined as the second height H2. As a non-limiting example shown in Fig. 10, the height from the lower surface 17 to the center of the third opening 27c may be defined as the third height H3. The first height H1 and the second height H2 may be the same as or different from the third height H3.

[0072] The center of each opening may be a point where the central axis of the outlet hole connected to the opening intersects with the opening. Specifically, the point where the central axis L1 of the first opening 27a and the first outlet hole 29a intersect may be the center of the first opening 27a. This also applies to the centers of the second opening 27b and the third opening 27c.

[0073] When the first height H1 and the second height H2 are the same as the third height H3, the heights at which the coolant is injected are the same, making it easier to control the flow of the coolant. However, the term "same height" here does not necessarily mean "same height" in the strict sense. It means that the ratio of the smallest of H1, H2, and H3 to the largest is 98% to 100%.

[0074] On the other hand, when the first height H1 and the second height H2 are different from the third height H3, the coolant is more likely to be supplied in accordance with the position of each cutting edge, and the cooling effect is more likely to be enhanced. As mentioned above, "the same height" does not necessarily mean "same height" in the strict sense, so "the first height H1 and the second height H2 are different from the third height H3" means that the ratio of the smallest of H1, H2, and H3 to the largest is less than 98%.

[0075] When the outflow holes 29 are inclined so as to move away from the lower surface 17 as they move away from the opening 27, the first height H1 and the second height H2 may be smaller than the third height H3. In this case, the first length G1 and the second length G2 may each be smaller than the third length G3.

[0076] When the outflow holes 29 are inclined so as to move away from the lower surface 17 as they move away from the opening 27, the coolant can be more easily injected farther if the height from the lower surface 17 to the center of the opening 27 is greater. Therefore, when the insert 1 has the above-described configuration, the coolant injected from the opening 27 is more easily supplied to each cutting edge, and the cooling effect is likely to be enhanced.

[0077] When the outflow holes 29 are inclined so as to approach the lower surface 17 as they move away from the opening 27, the first height H1 and the second height H2 may be greater than the third height H3. In this case, the first length G1 and the second length G2 may each be smaller than the third length G3.

[0078] When the outflow holes 29 are inclined so that they approach the lower surface 17 as they move away from the opening 27, the coolant can be more easily injected farther if the height from the lower surface 17 to the center of the opening 27 is lower. Therefore, when the insert 1 has the above configuration, the coolant injected from the opening 27 is more easily supplied to each cutting edge, which tends to improve the cooling effect.

[0079] As a non-limiting example shown in Figure 7, the opening 27 may have a shape with a major axis and a minor axis. Note that the major axis and minor axis here may be different from the major axis and minor axis used to define an ellipse. The major axis may be the longest line segment passing through the center of the shape and bounded by the periphery of the shape. The minor axis may be the shortest line segment passing through the center of the shape and bounded by the periphery of the shape.

[0080] 7, when viewed from above, if the width of the second opening 27b in the direction along the central axis L2 of the second outlet hole 29b is defined as a first width W1, the first width W1 corresponds to the major axis. Also, if the width of the second opening 27b in the direction perpendicular to the central axis L2 of the second outlet hole 29b is defined as a second width W2, the second width W2 corresponds to the minor axis.

[0081] In the non-limiting example shown in Fig. 7, the first width W1 is the major axis and the second width W2 is the minor axis, but there is no problem if the second opening 27b has a shape in which the first width W1 is the minor axis and the second width W2 is the major axis. The opening 27 only needs to have different sizes for the first width W1 and the second width W2. Furthermore, in the non-limiting example shown in Fig. 7, the major axis and the minor axis are orthogonal to each other, but the shape may be such that they are not orthogonal to each other.

[0082] When the insert 1 has the above-described configuration, pressure loss during injection of the coolant tends to be small. In other words, the coolant flows more easily than when the opening 27 is simply circular.

[0083] 7 , in a front view (top view) of the first surface 15, the width of the second opening 27b in a direction along the central axis L2 of the second outlet hole 29b may be larger than the width of the second opening 27b in a direction perpendicular to the central axis L2 of the second outlet hole 29b. In other words, in a top view, the first width W1 may be larger than the second width W2. Note that the second width W2 may be perpendicular to the first width W1 at the center of the first width W1.

[0084] When the insert 1 has the above-described configuration, it is easy to reduce the pressure loss of the coolant flowing out from the opening 27. Furthermore, since the second width W2 is smaller and the coolant flows out in a vertically long shape, the coolant not only cools the cutting edge 21 but also makes it easier to remove chips.

[0085] In the non-limiting example shown in FIG. 7, only the second opening 27b is shown, but the first opening 27a and the third opening 27c may also have the same configuration.

[0086] When the main body including the base portion 3 and the cutting portion 5 is integrally formed, examples of the material for the main body (the base portion 3 and the cutting portion 5) include inorganic materials such as cemented carbide, cermet, and ceramics. Examples of cemented carbide compositions include WC (tungsten carbide)-Co, WC-TiC (titanium carbide)-Co, and WC-TiC-TaC (tantalum carbide)-Co. WC, TiC, and TaC are hard particles, and Co is a binder phase. Cermets are sintered composite materials in which a ceramic component is combined with a metal. Specifically, examples of cermets include compounds whose main component is TiC or TiN (titanium nitride). However, the main body is not limited to these materials.

[0087] When the base portion 3 and the cutting portion 5 are formed as separate bodies, the base portion 3 and the cutting portion 5 may be made of different materials. Examples of the material of the base portion 3 include inorganic materials such as cemented carbide, cermet, and ceramics. The compositions of the cemented carbide and cermet are the same as those in the above examples. Furthermore, the material of the base portion 3 is not limited to these materials.

[0088] Examples of materials for the cutting portion 5 include cubic boron nitride (cBN) and diamond. Examples of diamond include polycrystalline diamond (PCD). Furthermore, the cutting portion 5 may contain materials other than these materials as long as they contain these materials as the main component. Note that the term "main component" here means the component with the largest content ratio by mass. However, the cutting portion 5 is not limited to these materials.

[0089] The insert 1 may also be configured to include a main body containing the above-mentioned materials and a coating layer that coats the main body. Examples of materials for the coating layer include aluminum oxide (alumina), titanium carbide, nitride, oxide, carbonate, oxynitride, and oxycarbonitride. The coating layer may contain only one of the above-mentioned materials, or may be configured by laminating multiple layers. However, the material for the coating layer is not limited to these materials.

[0090] The coating layer may be formed on the body by chemical vapor deposition (CVD) or physical vapor deposition (PVD). For example, if the coating layer is formed by the vapor deposition method while the body is held at the inner periphery of the hole 11, the coating layer can be easily formed to cover the entire surface of the body except for the inner periphery of the hole 11.

[0091] <Cutting Tool> Next, a cutting tool 101 according to a non-limiting embodiment of the present disclosure will be described.

[0092] The cutting tool 101 may have a holder 103 extending from a first end 103a to a second end 103b and having a pocket 105 (insert pocket) located on the side of the first end 103a, as shown in a non-limiting example in Figure 13, and the above-mentioned insert 1 located in the pocket 105.

[0093] 13, the holder 103 may be rod-shaped. The pocket 105 may be a portion where the insert 1 is attached. In this case, the base portion 3 of the insert 1 may be in direct contact with the pocket 105.

[0094] As a non-limiting example shown in FIG. 13 , the insert 1 may be mounted so that at least a part of the portion used as the cutting edge 21 in the cutting portion 5 protrudes outward from the holder 103 .

[0095] Steel, cast iron, etc. may be used as the material of the holder 103. In particular, when steel is used among these materials, the holder 103 has high toughness.

[0096] 13 shows a non-limiting example of a cutting tool used for so-called turning. Examples of turning include external diameter machining, internal diameter machining, end face machining, and grooving. The cutting tool is not limited to that used for turning. For example, the insert 1 of the above embodiment may be used in a cutting tool used for milling.

[0097] <Method for Manufacturing Machined Product> Next, a method for manufacturing a machined product according to a non-limiting embodiment of the present disclosure will be described.

[0098] The machined product can be produced by cutting the workpiece 201. A method for manufacturing a machined product in a non-limiting embodiment of the present disclosure may include the following steps: (1) a step of rotating the workpiece 201; (2) a step of bringing the cutting tool 101, as typified by the above-described embodiment, into contact with the rotating workpiece 201; and (3) a step of separating the cutting tool 101 from the workpiece 201.

[0099] More specifically, first, as in a non-limiting example shown in Fig. 14 , the workpiece 201 may be rotated around the axis R while the cutting tool 101 is brought relatively close to the workpiece 201. Next, as in a non-limiting example shown in Fig. 15 , the ridge line (cutting edge 21) of the cutting tool 101 may be brought into contact with the workpiece 201 to cut the workpiece 201. Then, as in a non-limiting example shown in Fig. 16 , the cutting tool 101 may be moved relatively away from the workpiece 201.

[0100] In a non-limiting example shown in Fig. 14, the axis R is fixed and the workpiece 201 is rotated around the axis R, and the cutting tool 101 is moved in the Y1 direction to approach the workpiece 201. In a non-limiting example shown in Fig. 15, at least a portion of the corner portion 35 and the first side 31 of the insert 1 that are used as the cutting edge 21 is brought into contact with the rotating workpiece 201, and the insert 1 is moved in the X1 direction to cut the workpiece 201. In a non-limiting example shown in Fig. 16, the cutting tool 101 is moved in the Y2 direction to move away from the rotating workpiece 201.

[0101] In the cutting process in the manufacturing method of the embodiment, the cutting tool 101 is moved in each step to bring the cutting tool 101 into contact with the workpiece 201 or to move the cutting tool 101 away from the workpiece 201, but of course, this is not limited to this form.

[0102] For example, in step (1), the workpiece 201 may be brought closer to the cutting tool 101. Similarly, in step (3), the workpiece 201 may be moved away from the cutting tool 101. When continuing the cutting process, the workpiece 201 may be kept rotating, and the step of bringing the cutting edge 21 of the insert 1 into contact with different locations on the workpiece 201 may be repeated.

[0103] Examples of materials for the workpiece 201 include hardened steel, carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0104] 1... Cutting insert (insert) 3... Base part 5... Cutting part 7... First end surface (top end surface) 9... Second end surface (bottom end surface) 11... Hole 13... First through hole 15... First surface (top surface) 17... Second surface (bottom surface) 19... Third surface (side surface) 21... Cutting edge 21a... First cutting edge 21b...Second cutting edge 21c...Corner cutting edge 23...Second through hole (through hole) 25...Slope 27...Opening 27a...First opening 27b...Second opening 27c...Third opening 29...Outflow hole 29a...First outflow hole 29b...Second outflow hole 29c...Third outflow hole 31...First side 33... Second side 35... Corner part 101... Cutting tool 103... Holder 103a...First end 103b...Second end 105...Pocket (insert pocket) 201...Workpiece D1...Inner diameter of first outlet hole D2...Inner diameter of second outlet hole D3...Inner diameter of third outlet hole G1...First length G2...Second length G3...Third length H1...First height H2...Second height H3...Third height L...Central axis of outlet hole L1...Central axis of first outlet hole L2...Central axis of second outlet hole L3...Central axis of third outlet hole R...Rotation axis of workpiece S...Reference plane W1...First width W2...Second width θ1...First inclination angle θ2...Second inclination angle θ3...Third inclination angle

Claims

1. A cutting insert comprising: a cutting portion having: a first surface; a second surface located opposite the first surface; a third surface connected to the first surface and the second surface; a cutting edge located at the intersection of the first surface and the third surface; and a through hole opening in the first surface, wherein the through hole has one or more openings opening in the first surface and one or more linear outflow holes extending from the openings, and an imaginary area extending the outflow hole from the opening in a direction along the central axis of the outflow hole intersects with the cutting edge.

2. The cutting insert according to claim 1, wherein an imaginary line extending from the opening to the central axis of the outlet hole intersects with the first surface.

3. The cutting insert according to claim 1, wherein an imaginary line extending from the opening to the central axis of the outlet hole is farther from the second surface than from the first surface.

4. The cutting insert according to claim 1, wherein the outflow holes are parallel to the second surface.

5. The cutting insert according to any one of claims 1 to 3, wherein the outflow hole is inclined so as to move away from the second surface as it moves away from the opening.

6. The cutting insert according to any one of claims 1 to 3, wherein the outflow hole is inclined so as to approach the second surface as it moves away from the opening.

7. A cutting insert according to any one of claims 1 to 6, wherein the through hole has a plurality of the openings and a plurality of the outflow holes extending from the plurality of openings, respectively.

8. A cutting insert according to claim 7, wherein the first surface has a corner portion, a first side connected to the corner portion, and a second side connected to the corner portion; the cutting edges have a corner cutting edge located at the corner portion, a first cutting edge located at the first side, and a second cutting edge located at the second side; the openings have a first opening opening toward the first cutting edge, a second opening opening toward the second cutting edge, and a third opening opening toward the corner cutting edge; and the outflow holes have a first outflow hole extending from the first opening, a second outflow hole extending from the second opening, and a third outflow hole extending from the third opening.

9. The cutting insert according to claim 8, wherein the inner diameters of the first outlet hole and the second outlet hole are each larger than the inner diameter of the third outlet hole.

10. A cutting insert as described in claim 8, wherein, when a virtual plane parallel to the second surface is taken as a reference plane, the inclination angles that the central axes of the first outlet hole and the second outlet hole make with the reference plane are the same as the inclination angles that the central axis of the third outlet hole makes with the reference plane.

11. A cutting insert as described in claim 8, wherein, when a virtual plane parallel to the second surface is taken as a reference plane, the inclination angles formed by the central axis of the first outlet hole and the central axis of the second outlet hole with respect to the reference plane are different from the inclination angles formed by the central axis of the third outlet hole with respect to the reference plane.

12. A cutting insert as described in claim 11, wherein the outflow holes are inclined so as to move away from the second surface as they move away from the opening, and when an imaginary plane parallel to the second surface is taken as a reference plane, the inclination angles formed by the central axes of the first outflow holes and the second outflow holes with the reference plane are each greater than the inclination angles formed by the central axis of the third outflow hole with the reference plane.

13. A cutting insert as described in claim 11, wherein the outflow holes are inclined so as to approach the second surface as they move away from the opening, and when an imaginary plane parallel to the second surface is taken as a reference plane, the inclination angles formed by the central axes of the first outflow holes and the second outflow holes with the reference plane are each greater than the inclination angles formed by the central axis of the third outflow hole with the reference plane.

14. The cutting insert according to claim 8, wherein the height from the second surface to the center of the first opening and the height from the second surface to the center of the second opening are the same as the height from the second surface to the center of the third opening.

15. The cutting insert according to claim 8, wherein the height from the second surface to the center of the first opening and the height from the second surface to the center of the second opening are different from the height from the second surface to the center of the third opening.

16. The cutting insert according to claim 15, wherein the outflow holes are inclined so as to move away from the second surface as they move away from the opening, and the height from the second surface to the center of the first opening and the height from the second surface to the center of the second opening are lower than the height from the second surface to the center of the third opening.

17. The cutting insert according to claim 15, wherein the outflow holes are inclined so as to approach the second surface as they move away from the opening, and the height from the second surface to the center of the first opening and the height from the second surface to the center of the second opening are greater than the height from the second surface to the center of the third opening.

18. The cutting insert of claim 1, wherein the opening has a shape with a major axis and a minor axis.

19. A cutting insert according to claim 18, wherein, in a front view of the first surface, the width of the opening in a direction along the central axis of the outlet hole is larger than the width of the opening in a direction perpendicular to the central axis of the outlet hole.

20. A cutting tool comprising: a holder extending from a first end toward a second end and having a pocket located on the side of the first end; and a cutting insert according to any one of claims 1 to 19 located in the pocket.

21. A method for manufacturing a machined product, comprising the steps of: rotating a workpiece; bringing the cutting tool according to claim 20 into contact with the rotating workpiece; and separating the cutting tool from the workpiece.

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