Cutting insert, cutting tool and method for producing a machine-made product

Abstract

A cutting insert (1), comprising: a first surface (3) having a corner (9) with a convex-curved shape in an outward direction and a first side (11) and a second side (13) extending each from the corner (9), a second surface (5) which is arranged on one of the sides opposite the first surface (3), and a third surface (7) arranged between the first surface (3) and the second surface (5), wherein an imaginary plane that is orthogonal to a central axis (O1) passing through a center point of the first surface (3) and a center point of the second surface (5), and is arranged between the first surface (3) and the second surface (5), is assumed to be the reference plane, the first surface (3) further has an inclined surface (17) which approaches the reference plane with increasing distance from the corner (9), the inclined surface (17) a first inclined surface (19) which is inclined at a first angle (θ1), a second inclined surface (21) which is arranged further away from the corner (9) than the first inclined surface (19) and is inclined at a second angle (θ2), and a third inclined surface (23) which is arranged further away from the corner (9) than the second inclined surface (21) and is inclined at a third angle (θ3), the first inclined surface (19) has a concave-curved shape in a cross-section orthogonal to an angle bisector (L1) of the corner (9), the second inclined surface (21) is a flat surface, and, in a cross-section that includes the angle bisector (L1) of the corner (9) and is orthogonal to the reference plane, the second angle (θ2) is smaller than the first angle (θ1) and the third angle (θ3), wherein in a top view of the first surface (3) a length (L32) of the third inclined surface (23) in a direction orthogonal to the angle bisector (L1) of the corner (9) is greater than a length (L22) of the second inclined surface (21) in the direction orthogonal to the angle bisector (L1) of the corner (9).

Description

TECHNICAL AREA

[0001] The present embodiments generally relate to cutting inserts for use in a cutting operation. Specifically, the present embodiments relate to cutting tools for use in a turning operation, such as external and internal machining. BACKGROUND

[0002] An indexable insert, as described in JP 2000-153 401 A, is known as an insert for use in a cutting operation of a workpiece, such as metal. JP 2000-153 401 A describes the cutting insert whose upper surface has a flat surface and a curved surface in the sequence from a corner to a center.

[0003] Furthermore, for example, a cutting insert is known from WO 2015 / 119258 A1, comprising: a first surface having a corner with a convex-curved shape in an outward direction and a first side and a second side each extending from the corner; a second surface arranged on a side opposite the first surface; and a third surface arranged between the first surface and the second surface, wherein an imaginary plane orthogonal to a central axis passing through a center point of the first surface and a center point of the second surface, and arranged between the first surface and the second surface, is assumed to be the reference plane; the first surface further comprising an inclined surface which approaches the reference plane with increasing distance from the corner; the inclined surface comprising: a first inclined surface inclined at a first angle; a second inclined surface;a third inclined surface, which is located further from the corner than the first inclined surface and is inclined at a second angle, and a third inclined surface, which is located further from the corner than the second inclined surface and is inclined at a third angle.

[0004] Further cutting inserts are known from, for example, JP 2015 - 208 793 A and US 2015 / 0 043 982 A1.

[0005] It is an object of the present invention to increase the machining performance during machining. BRIEF EXPLANATION

[0006] The problem is solved by a cutting insert having the features of claims 1, 2, 3 and 6. The problem is further solved by a cutting tool having the features of claim 12. The problem is also solved by a method for producing a machined product having the features of claim 13. Further embodiments of the cutting insert are described in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view showing a cutting insert in one of the embodiments, Fig. 2 is a top view of the in Fig. 1 cutting insert shown, Fig. 3 is an enlarged view of one in Fig. 1 of the area shown A1, Fig. 4 is an enlarged view of one in Fig. 2 shown area A2, Fig. 5 is an enlarged view showing the same area as in Fig. 4 shows, Fig. 6 is a side view of the in Fig. 2. Cutting insert shown, viewed from a B1 direction, Fig. 7 is a cross-sectional view along line XII-XII in which in Fig. 4 shown uses, Fig. 8 is a cross-sectional view along line XIII-XIII in which in Fig. 4 shown uses, Fig. Figure 9 is a cross-sectional view along line IX-IX in which in Fig. 4 shown uses, Fig. Figure 10 is a cross-sectional view along line XX in which Fig. 4 shown uses, Fig. Figure 11 is a cross-sectional view along line XI-XI in which Fig. 4 shown uses, Fig. 12 is an enlarged view of one in Fig. 6 shown area A3, Fig. 13 is a side view of the in Fig. 2. Cutting insert shown, viewed from a B2 direction, Fig. 14 is an enlarged view of one in Fig. 13 shown area A4, Fig. Figure 15 is a perspective view showing a cutting tool in one of the embodiments, Fig. Figure 16 is a schematic representation showing one of the steps in a process for manufacturing a machined product in one of the embodiments, Fig. Figure 17 is a schematic representation showing one of the steps of the process for manufacturing a machined product in the embodiment, and Fig. Figure 18 is a schematic representation showing one of the steps of the process for manufacturing a machined product in the embodiment. EXECUTION FORMS

[0007] Examples of workpieces that are cut in a cutting process include carbon steel, alloy steel, stainless steel, aluminum, cast iron, and non-ferrous metals. Of these workpieces, aluminum, for example, is soft, and the chips are likely to be long and prone to becoming welded to the cutting insert. Therefore, with the cutting insert described in patent document 1, the chips can protrude excessively depending on the type of workpiece. Consequently, it was difficult to guide the chips stably.

[0008] The cutting inserts 1 (hereinafter also simply referred to as "inserts 1") in embodiments are described in detail below with reference to the drawings. For the sake of clarity, the drawings mentioned below show only the main elements necessary to describe the embodiments in simplified form. The cutting inserts 1 are therefore capable of having any further structural elements that are not shown in the drawings referenced in this disclosure. The dimensions of the elements in the individual drawings do not accurately represent either the dimensions of the actual structural elements or the dimensional relationships of these elements.

[0009] A cutting operation can be performed with a cutting tool that has the insert 1 in one of the embodiments. Examples of the cutting tool are a turning tool and a milling tool. <Einsätze>

[0010] The insert 1 in one of the embodiments has a first surface 3, a second surface 5, and a third surface 7. The second surface 5 is arranged on a side opposite the first surface 3. The third surface 7 is arranged between the first surface 3 and the second surface 5. The first surface 3 can have a polygonal shape in the present disclosure. The first surface 3 can have a quadrilateral shape, as shown in Fig. Figure 1 shows that, similar to the first surface 3, the second surface 5 can have a polygonal shape.

[0011] The second surface 5 can be the same size as the first surface 3, or alternatively, smaller than the first surface 3. The second surface 5 can have the same shape as the first surface 3, or be slightly smaller than the first surface 3. The insert 1 has in the Fig. In the embodiment shown in Figure 1, the plate shape is polygonal. Usually, the first surface 3 is a top surface, the second surface 5 is a bottom surface, and the third surface 7 is a side surface.

[0012] An imaginary line passing through a center point of the first surface 3 and a center point of the second surface 5 is assumed to be the central axis O1. The first surface 3 can have a shape that is rotationally symmetric about 180° based on the central axis O1, as shown in Fig. Figure 2 illustrates that the shape of insert 1 is not limited to the configuration above. It is unproblematic even if the first surface 3, for example, has a triangular or hexagonal shape.

[0013] The first surface 3 in the present revelation has a corner 9, a first side 11, and a second side 13. The first side 11 and the second side 13 extend from the corner, respectively. In other words, the corner 9 is located between the first side 11 and the second side 13.

[0014] Corner 9 has in the Fig. In the embodiment shown in Figure 3, the corner 9 has an outwardly convex curved shape. The radius of curvature of the corner 9 with the convex curved shape can be kept constant or changed in a top view of the first surface 3. The corner 9 in the insert 1 has the shape of a circular arc, the radius of curvature of which is shown in the top view in a Fig. The embodiment shown in section 4 is kept constant.

[0015] The first side 11 and the second side 13 on the first surface 3 can visually have an approximately rectilinear shape and need not have a strictly rectilinear shape as a whole. Both the first side 11 and the second side 13 can have a rectilinear section on at least one part connected to corner 9. Alternatively, the first side 11 and the second side 13 on the first surface 3 can, for example, have a slightly convex-curved or concave-curved shape.

[0016] The third surface 7, which is arranged between the first surface 3 and the second surface 5, is located in the Fig. 1. In the embodiment shown, each in conjunction with the first surface 3 and the second surface 5. Since the first surface 3 has the polygonal shape shown in Fig. In the embodiment shown in Figure 1, the third surface 7 has a plurality of surface areas, each of which is connected to individual sides and the corners 9 on the first surface 3. In an embodiment shown in Figure 1, the third surface 7 has a plurality of surface areas, each of which is connected to individual sides and the corners 9 on the first surface 3. Fig. Figure 6 shows a first side surface 7a, a second side surface 7b and a corner side surface 7c as the plurality of surface areas.

[0017] In the Fig. In the embodiment shown in Figure 6, the first side surface 7a is arranged along the first side 11 of the first surface 3. The second side surface 7b is arranged along the second side 13 of the first surface 3. The corner side surface 7c is arranged along the corner 9 of the first surface 3. In the embodiment shown in Fig. In the embodiment shown in Figure 6, the corner side surface 7c is arranged between the first side surface 7a and the second side surface 7b and is adjacent to both the first side surface 7a and the second side surface 7b. The first side surface 7a and the second side surface 7b can have a flat shape. The corner side surface 7c can have a convex-curved surface shape.

[0018] In the Fig. In the embodiment shown in Figure 6, the second surface 5 is smaller than the first surface 3. In this case, the individual surface areas that form the third surface 7 (the first side surface 7a, the second side surface 7b, the corner side surface 7c, etc.) can be inclined so that they approach the central axis O1 from one side of the first surface 3 to one side of the second surface 5.

[0019] A cutting edge 15 can be arranged at least on part of an interface between the first surface 3 and the third surface 7. In the Fig. In the embodiment shown in Figure 3, the cutting edge 15 is arranged at corner 9, a part of the first side 11, and a part of the second side 13 on a ridge line where the first surface 3 intersects the third surface 7. Alternatively, the cutting edge 15 can be arranged along the entire first side 11 and the second side 13.

[0020] For the sake of simplicity, a portion of the cutting edge 15 located at corner 9 can be referred to as "a corner cutting edge 15c". A portion of the cutting edge 15 located on the first side 11 can be referred to as "a first cutting edge 15a". A portion of the cutting edge 15 located on the second side 13 can be referred to as "a second cutting edge 15b".

[0021] In cases where the cutting edge 15 is used in a cutting operation, at least part of the first surface 3 can be used as a rake surface and at least part of the third surface 7 can be used as a clearance surface.

[0022] As in Fig. As shown in Figure 3, the first surface 3 in the present disclosure has an inclined surface 17 extending from the corner 9 towards the center of the first surface 3. In cases where the corner cutting edge 15c is used in a cutting operation, the inclined surface 17 can be used as a chipping surface.

[0023] An imaginary plane, orthogonal to the central axis O1 and lying between the first surface 3 and the second surface 5, is assumed to be the reference plane S1, as in Fig. 6 shown. Fig. 7 is a cross-sectional view along line VII-VII in which in Fig. 4 shown in the application 1. It is a cross-section that encloses an angle bisector L1 of corner 9 and runs orthogonally to the reference plane S1.

[0024] The inclined surface 17 is inclined in such a way as to approach the reference plane S1 with increasing distance from corner 9, as shown in Fig. 7 shown. Fig. 8, Fig. 9 to Fig. 10 are cross-sections which in the top view run orthogonally to the reference plane S1 and orthogonally to the second cutting edge 15b.

[0025] The inclined surface 17 in the present disclosure comprises a first inclined surface 19, a second inclined surface 21, and a third inclined surface 23. Specifically, the first inclined surface 19, the second inclined surface 21, and the third inclined surface 23 are arranged in that order from corner 9 to the center of the first surface 3. In other words, the second inclined surface 21 is located further from corner 9 than the first inclined surface 19, and the third inclined surface 23 is located further from corner 9 than the second inclined surface 21.

[0026] The first inclined surface 19 is inclined at a first angle 01. The second inclined surface 21 is inclined at a second angle θ2. The third inclined surface 23 is inclined at a third angle θ3. The first angle 01, the second angle θ2, and the third angle θ3 can be obtained by an angle relative to the reference plane S1 in a cross-section that includes the angle bisector L1 and is orthogonal to the reference plane S1, as shown in Fig. 7 shown.

[0027] Since corner 9 in the present disclosure has a convex-curved shape in an outward direction in the top view, the angle bisector L1 can be replaced by an angle bisector whose corner is an intersection point obtained by imaginary extensions of the first side 11 and the second side 13.

[0028] The first inclined surface 19 can have a planar surface shape or alternatively a concave-curved surface shape, which is specified by a concave-curved surface shape in a cross-section orthogonal to the angle bisector L1, as in Fig. Figure 11 shows the second inclined surface 21, which can be a flat surface in the top view. Fig. Figure 11 is a cross-sectional view that is orthogonal to the reference plane S1 and orthogonal to the angle bisector L1.

[0029] In cases where the first inclined surface 19 has the concave-curved surface shape described above, chips produced during shallow machining, such as when using the corner cutting edge 15c, are likely to be curved on the first inclined surface 19. This facilitates the stabilization of a chip flow direction. In cases where the second inclined surface 21 has the configuration described above, the chips tend to be curved while simultaneously preventing chip adhesion. This facilitates chip removal to the correct length.

[0030] The term "planar surface" as used here does not necessarily have to refer to a strictly planar surface shape. For example, the planar surface can have a shape defined by a gently curved line with a radius of curvature of 5 mm or more in a cross-section perpendicular to the angle bisector L1, or alternatively, a shape with an arithmetic surface roughness of approximately 0.5 µm.

[0031] The first angle θ1 can be set to, for example, 20-30°. The second angle θ2 can be set to, for example, 0-10°. The third angle θ3 can be set to, for example, 10-20°. If the first angle θ1 is not constant, a maximum value of the inclination angle of the first inclined surface 19 can be set to the first angle 10.

[0032] If the second angle θ2 is not constant, the maximum value of an inclination angle of the second inclined surface 21 can be a second angle θ2. If the third angle θ3 is not constant, the maximum value of an inclination angle of the third inclined surface 23 can be a third angle θ3. In a Fig. In the embodiment shown in Figure 7, the second angle θ2 is smaller than the first angle θ1 and the third angle θ3.

[0033] The second angle θ2 is in the Fig. In the embodiment shown in Figure 7, the angle is relatively small, and it is therefore likely that the chips will be curved on the second inclined surface 21. Since the second inclined surface 21 is inclined such that it approaches the reference plane S1 as it moves away from corner 9, it is less likely that chips will be welded to the second inclined surface 21. The first angle θ1 is shown in the Fig. In the embodiment shown in Figure 7, the cutting edge is relatively large. This results in high cutting performance, and it is less likely that chips will be welded on near the cutting edge 15.

[0034] The third angle θ3 is in the Fig. The surface area is relatively large in the embodiment shown in Figure 7. Therefore, chip clogging is less likely during high-feed machining, e.g., in cases where the chips jump over the second inclined surface 21 without coming into contact with it. Chip clogging is also less likely during deep-depth machining, such as when using the corner 9 and the first side 11 as the cutting edge 15. Consequently, the insert 1 of the present disclosure achieves stable chip guidance.

[0035] The third angle θ3 can be larger than the first angle θ1. Alternatively, the first angle θ1 can be larger than the third angle θ3, as in the Fig. 7 of the illustrated embodiment. If the first angle θ1 is larger than the third angle 03, the cutting performance for a workpiece is further improved, and chips are much less likely to be welded near the cutting edge 15. If the third angle θ3 is smaller than the first angle 01, the chips are likely to be curved on the third inclined surface 23.

[0036] The dimensions of insert 1 are not limited to specific values. For example, the maximum width W of the first surface 3 can be set to approximately 6–25 mm. The height H from the first surface 3 to the second surface 5 can be set to approximately 1–10 mm. As used here, the term "height from the first surface 3 to the second surface 5" refers to a length in a direction parallel to the central axis O1 between an upper end of the first surface 3 and a lower end of the second surface 5.

[0037] For example, cemented carbide or cermet can be used as the material for insert 1. Examples of cemented carbide compositions include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co, where WC, TiC, and TaC are hard particles and Co is a binder phase.

[0038] Cermet is a sintered composite material obtained by combining metal with a ceramic component. Examples of cermet include titanium compounds, primarily composed of titanium carbide (TiC) or titanium nitride (TiN). It goes without saying that the material of Insert 1 is not limited to the compositions mentioned above.

[0039] A surface of insert 1 can be coated with a coating layer using a chemical vapor deposition (CVD) or a physical vapor deposition (PVD) process. Examples of coating layer compositions include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al₂O₃).

[0040] The shape of the third inclined surface 23 is not particularly restricted. For example, the third inclined surface 23 can have a concave-curved surface shape, specified by a concave-curved shape in cross-section that encloses the angle bisector L1 and is orthogonal to the reference plane S1. Alternatively, the third inclined surface 23 can be a planar surface, as shown in Fig. Figure 3 shows that if the third inclined surface 23 is the flat surface, the chips tend to curl on the third inclined surface 23 upon contact with the third inclined surface.

[0041] A length L32 of the third inclined surface 23 in a direction orthogonal to the angle bisector L1 can be greater in plan view than a length L22 of the second inclined surface 21 in a direction orthogonal to the angle bisector L1. If the length L32 of the third inclined surface 23, which is located further from corner 9 than the second inclined surface 21, is greater than the length L22 of the second inclined surface 21, the chips tend to be guided stably on the third inclined surface 23, even if the flow direction of the chips generated at corner 9 is varied.

[0042] Alternatively, in the top view, the length L21 of the second inclined surface 21 in a direction along the angle bisector L1 can be greater than the length L11 of the first inclined surface 19 in the direction along the angle bisector L1. If the length L21 of the second inclined surface 21 is greater than the length L11 of the first inclined surface 19, the chips tend to be guided stably on the second inclined surface 21. If the length L11 of the first inclined surface 19 is less than the length L21 of the second inclined surface 21, the corner cutting edge 15c has increased durability.

[0043] However, in the top view, the length L31 of the third inclined surface 23 in the direction along the angle bisector L1 can alternatively be greater than the length L21 of the second inclined surface 21 in the direction along the angle bisector L1. If the length L31 of the third inclined surface 23, which is mainly used for guiding the chips during deep machining, is greater than the length L21 of the second inclined surface 21, which is mainly used for guiding the chips during shallow machining, the chips can be guided more effectively during deep machining. One specific reason for this is as follows.

[0044] The width of a chip increases, and the chip tends to extend to one side opposite the feed direction of a cutting tool during deep-depth machining. However, if the length L31 of the third inclined surface 23 is greater than the length L21 of the second inclined surface 21, ample space for chip curvature is ensured on the third inclined surface 23. This results in good chip guidance during deep-depth machining. If the length L21 of the second inclined surface 21 is less than the length L31 of the third inclined surface 23, the likelihood of the chip coming into strong contact with the second inclined surface 21 is reduced. This results in good chip guidance on the third inclined surface 23.

[0045] The first surface 3 can further comprise a pair of recessed parts 25 arranged such that the second inclined surface 21 is arranged between them in the direction orthogonal to the angle bisector L1, as shown in Fig. 2 of the illustrated embodiment. If the first surface 3 has the recess parts 25, stable chip guidance is achievable both in shallow and deep machining.

[0046] Chips tend to make stable contact with the second inclined surface 21 because the recessed parts 25 do not impede chip flow during shallow machining, as is the case, for example, when using the corner cutting edge 15c. This results in stable chip guidance during shallow machining. Additionally, during deep machining, ample space is provided for the flow of chips generated by the first side 11, as is the case when using the corner 9 and the first side 11 as the cutting edge 15. Therefore, the chips generated by the first side 11 are less prone to clogging, thus achieving stable chip guidance even during deep machining.

[0047] Although the shape of the recess parts 25 is not particularly restricted, they can have a concave-curved surface shape. The recess parts 25 with the concave-curved surface shape can be specified by a concave-curved cross-section orthogonal to the angle bisector L1. Alternatively, the recess parts 25 can be specified by a concave-curved cross-section orthogonal to the datum plane S1 and parallel to the angle bisector L1. If the recess parts 25 have the concave-curved surface shape, it is much less likely that chips will clog the recess parts 25, even if the chips come into contact with the surfaces of the recess parts 25. This results in improved chip evacuation performance.

[0048] In cases where the first surface 3 has the pair of recess parts 25, the length L41 of the pair of recess parts 25 in a direction along the angle bisector L1 can be greater than the length L21 of the second inclined surface 21 in the direction along the angle bisector L1 when viewed from a top view of the first surface 3. When the recess parts 25 have the above configuration, it is easier for the chips to make stable contact with the second inclined surface 21 over a wide area of ​​the second inclined surface 21.

[0049] Of the pair of recess parts 25, in plan view, recess part 25a, which is arranged on one side of the first side 11, can be configured to have a length L42 in a direction along the first side 11 that is greater than a length L43 in a direction orthogonal to the first side 11. Of the pair of recess parts 25, recess part 25b, which is arranged on one side of the second side 13, can be configured in plan view to have a length L44 in a direction along the second side 13 that is greater than a length L45 in a direction orthogonal to the second side 13.

[0050] If the pair of recess parts 25 has the above configuration, a wide space remains for the flow of chips produced from the first side 11 or the second side 13, even in a cutting operation with a higher depth of cut, ensuring the length L22 of the second inclined surface 21 in the direction orthogonal to the angle bisector L1.

[0051] In the Fig. In the embodiment shown in Figure 5, the recess part 25a of the pair of recess parts 25, which is arranged on the side of the first side 11, is arranged on a second imaginary straight line L3 that passes through a boundary between the corner 9 and the second side 13 and is orthogonal to the second side 13 in the top view. When the recess part 25a is arranged as described above, improved chip removal performance can be achieved for the following reason.

[0052] Since the chip flow direction of chips generated from corner 9 differs from that of chips generated from the second side 13, the chip flow direction at the boundary between corner 9 and the second side 13 tends to become unstable. However, because the recess portion 25a is positioned in a direction in which chips with an unstable flow direction are likely to flow, chip clogging is less probable. This results in improved chip ejection performance.

[0053] In the Fig. In the embodiment shown in Figure 5, the recess part 25b of the pair of recess parts 25, which is arranged on the side of the second side 13, is arranged on a first imaginary straight line L2 that passes through a boundary between the corner 9 and the first side 11 and is orthogonal to the first side 11 in the top view. When the recess part 25b is arranged as described above, improved chip removal performance is achieved during the time in which the corner 9 and the first side 11 are used as a cutting edge 15.

[0054] The inclined surface 17 can further comprise a fourth inclined surface 27, which is flat, arranged between the first inclined surface 19 and the second inclined surface 21, and inclined at a fourth angle θ4. In the case of the inclusion of the fourth inclined surface, a cross-section enclosing the angle bisector L1 and orthogonal to the reference plane S1 can be formed as shown in Fig. In the embodiment shown in Figure 7, the fourth angle θ4 is smaller than the first angle θ1 and larger than the second angle θ2.

[0055] In the case of the inclusion of the fourth inclined surface 27 with the above configuration, the chip flow direction along the first inclined surface 19 changes stepwise through the fourth inclined surface 27. It is therefore likely that the chips will flow easily to the second inclined surface 21, and it is less likely that the chips will clog the second inclined surface 21.

[0056] As described above, the pair of recess parts 25 can be arranged such that the second inclined surface 21 lies between them in a direction orthogonal to the angle bisector L1. Alternatively, the pair of recess parts 25 can be arranged such that the fourth inclined surface 27 is arranged between them in a direction orthogonal to the angle bisector L1, in addition to the second inclined surface 21. Alternatively, the pair of recess parts 25 can also be arranged such that the fourth inclined surface 27 is arranged between them in a direction orthogonal to the angle bisector L1, instead of the second inclined surface 21.

[0057] The first area 3 shows in the Fig. In the embodiment shown in Figure 3, a surface extends along the first side 11 and is inclined such that it approaches the reference plane S1 as it moves away from the first side 11. This surface can be used as a chipping surface when using the first cutting edge 15a. In the embodiment shown in Fig. In the embodiment shown in Figure 3, the first surface 3 also has a surface that extends along the second side 13 and is inclined such that it approaches the reference plane S1 as it moves away from the second side 13. This surface can be used as a chipping surface when using the second cutting edge 15b.

[0058] The first surface 3 has such a shape that it is based on the angle bisector L1 in the Fig. 4 is line-symmetric. In cases where the first surface 3 has a line-symmetric shape, as in Fig. As shown in Figure 4, an equivalent cutting performance can be achieved both when corner 9 and first side 11 are used as cutting edge 15 and when corner 9 and second side 13 are used as cutting edge 15.

[0059] In the present disclosure, the corners 9 have a convex-curved shape in an outward direction in the top view. The height of each of the corners 9 from the reference plane S1 can be kept constant or changed in the side view.

[0060] The corners 9 are arranged such that the height of a center intersecting the angle bisector L1 is greatest and decreases from the center towards the first side 11 and the second side 13 in an embodiment which is Fig. Figure 12 shows that the corner cutting edge 15c, located at each of the corners 9, has a greater height from the reference plane S1, as it is further away from the first side 11 and the second side 13. When the corners 9 have the configuration shown above, it is easier for the insert 1 to cut into a workpiece during a cutting operation. Fig. Figure 12 is an enlarged view of insert 1 viewed from the direction along the angle bisector L1.

[0061] In the plan view shown in the present disclosure, the first side 11 has an approximately rectilinear shape. The height of the first side 11 from the reference plane S1 can be kept constant or varied in the side view. The first side 11 can have a first section 29, a second section 31, and a third section 33, each of which has a rectilinear shape, as shown in a Fig. 14 illustrated embodiment. Fig. Figure 14 is an enlarged view of insert 1 viewed from a direction parallel to the reference plane S1 and orthogonal to the angle bisector L1.

[0062] The first section 29 is adjacent to corner 9 and is inclined relative to corner 9. In this case, the inclination angle of the first section 29 with respect to the reference plane S1 can be smaller than the inclination angle of corner 9 with respect to the reference plane S1.

[0063] The second section 31 is adjacent to the first section 29 and is inclined with respect to the first section 29. In this case, the angle of inclination of the second section 31 relative to the reference plane S1 can be greater than the angle of inclination of the first section 29 relative to the reference plane S1. The third section 33 is adjacent to the second section 31 and is inclined with respect to the second section 31. In this case, the angle of inclination of the third section 33 relative to the reference plane S1 can be less than the angle of inclination of the second section 31 relative to the reference plane S1.

[0064] The first page 11 may also have, in addition to the first section 29, the second section 31 and the third section 33, a first connecting section 35 to connect the corner 9 and the first section 29, a second connecting section 37 to connect the first section 29 and the second section 31 and a third connecting section 39 to connect the second section 31 and the third section 33.

[0065] The first connecting section 35 can have a curved shape that projects towards the reference plane S1, as shown in Fig. The second connecting section 37 can have a curved shape that projects in a direction away from the reference plane S1, as shown in Figure 14. Fig. 14. The third connecting section 39 can have a curved shape that projects in the direction of the reference plane S1, as in the embodiment shown in Fig. 14 illustrated embodiment.

[0066] The second page 13 has in the Fig. In the embodiment shown in Figure 12, the second side 13 has a line-symmetrical shape with respect to the first side 11 based on the central axis O1. The second side 13 can have sections that correspond to the first section 29, the second section 31, the third section 33, the first connecting section 35, the second connecting section 37 and the third connecting section 39 on the first side 11, as shown in Figure 12. Fig. 12 illustrated embodiment.

[0067] In the Fig. In the embodiment shown in Figure 5, the first imaginary line L2 and the second imaginary line L3 intersect on the fourth inclined surface 27 in the top view. If the fourth inclined surface 27 is arranged as described above, the chips can be stably removed both when using corner 9 and the first side 11 as the cutting edge 15 and when using corner 9 and the second side 13 as the cutting edge 15 for the following reason.

[0068] If the fourth angle θ4 of the fourth inclined surface 27 is smaller than the first angle θ1 and larger than the second angle θ2, a surface area formed by the first inclined surface 19, the fourth inclined surface 27, and the second inclined surface 21 has a concave shape. If the first connecting section 35 and a portion of the second side 13 corresponding to the first connecting section 35 have a curved shape projecting towards the reference plane S1, the chips produced at the above sections tend to be curved into a concave shape.

[0069] When the first imaginary line L2 intersects the second imaginary line L3 on the fourth inclined surface 27 as described above, the concavely curved chips tend to flow within the concave surface area, both when corner 9 and the first side 11 are used as the cutting edge 15 and when corner 9 and the second side 13 are used as the cutting edge 15. This results in a state where the chips, curved in the concave shape, are wound up or coiled within the concave surface area. Consequently, because the chip flow direction becomes stable, chip clogging is less likely, and the chips can be removed appropriately.

[0070] As in the Fig. In the embodiment shown in Figure 5, a line orthogonal to the second connecting section 37 is assumed to be the third imaginary line L4, and a line orthogonal to a portion of the second side 13, corresponding to the second connecting section 37, is assumed to be the fourth imaginary line L5. Of the pair of recess parts 25, the recess part 25b, which is located on the side of the second side 13, can be positioned on one side of corner 9 with respect to the third imaginary line L4. When the recess part 25a is arranged as described above, improved chip removal performance can be achieved for the following reason.

[0071] A chip width is greater when the second section 31 is used as the cutting edge 15 than when only the corner 9 is used as the cutting edge 15. When the recess part 25b is located on the side of corner 9 on the third imaginary line L4, the wider chips tend to come into contact with the recess part 25b. Consequently, the wider chips tend to be wound around the recess part 25b, making chip clogging less likely and resulting in improved chip evacuation.

[0072] The pair of recess parts 25 can be viewed from above as well as in the Fig. In the embodiment shown in Figure 5, the recess part 25a is arranged on the side of the first side 11, with respect to the fourth imaginary line L5, on one side of the corner 9. When the recess part 25a is arranged as described above, improved chip removal performance can be achieved for the following reason.

[0073] A chip width is greater when a section corresponding to the second section 31 is used as cutting edge 15 than when only corner 9 is used as cutting edge 15. When the recess portion 25a is positioned on the side of corner 9 based on the fourth imaginary line L5, the wider chips tend to make contact with the recess portion 25a. The wider chips tend to wrap around the recess portion 25a, making chip clogging less likely and resulting in improved chip evacuation performance.

[0074] The insert 1 has a through-hole 41 that opens into the first surface 3 and the second surface 5 in one of the embodiments. The through-hole 41 can extend from a central portion of the first surface 3 to a central portion of the second surface 5. The through-hole 41 can be used to fasten the insert 1 to a holder of the cutting tool. The insert 1 can be fastened, for example, by inserting a screw into the through-hole 41 and screwing the insert 1 to the holder.

[0075] In this embodiment, the direction of extension of the through-hole 41, i.e., its direction of penetration, is orthogonal to the first surface 3 and the second surface 5. Since the through-hole 41 extends from the central part of the first surface 3 to the central part of the second surface 5, a center point of the through-hole 41 coincides with the central axis O1 in Fig. 1 together. <schneidwerkzeuge>

[0076] The cutting tool 101 in one of the embodiments is described below with reference to the drawings.

[0077] The cutting tool 101 in the Fig. The embodiment shown in Figure 15 comprises a holder 105 having a pocket 103 on one side of a front end thereof, and the insert arranged in the pocket 103. The insert is positioned such that at least a portion of it, which is used as a cutting edge, projects from the front end of the holder 105 in the cutting tool 101 in the present embodiment.

[0078] Holder 105 has a long, narrow rod shape. The single pocket 103 is located on one side of the front end of holder 105. The pocket 103 is a component that allows the insert to be attached and opens into a front end surface of holder 105. Alternatively, the pocket 103 can also open into a side surface of holder 105. This facilitates the attachment of the insert. Specifically, the pocket 103 has a seating surface parallel to a lower surface of holder 105 and a limiting side surface that is inclined relative to the seating surface.

[0079] The insert is positioned in pocket 103. The second surface of the insert can be in direct contact with pocket 103. Alternatively, a sheet can be placed between the insert and pocket 103.

[0080] The insert is positioned such that parts used as cutting edges protrude outwards from the holder 105. In the present disclosure, the insert is fastened to the holder 105 by a fastening screw 107. Specifically, the insert is fastened to the holder 105 by inserting the fastening screw 107 into a screw hole in the insert and a front end of the fastening screw 107 into a screw hole (not shown) in the insert pocket 103, so that a threaded engagement is created between the screw parts.

[0081] For example, steel or cast iron can be used for holder 105. Of these materials, steel with increased toughness is particularly preferred.

[0082] The present disclosure has shown and described the cutting tools for use in the so-called turning process. Examples of turning processes include internal machining, external machining, and grooving. The cutting tools are not limited to those used for turning. For example, the inserts in the above embodiments can be used for a cutting tool for use in a milling operation. <Verfahren zur Herstellung eines maschinell bzw. spanabhebend bearbeiteten Produkts>

[0083] A method for manufacturing a machined product in embodiments is described below with reference to the drawings.

[0084] The machined product 203 can be produced by performing a cutting operation on a workpiece 201. The method for producing the machined product 203 in the present disclosure comprises the following steps: (1) Turning the workpiece 201, (2) Bringing the cutting tool 101 shown in the above embodiment into contact with the workpiece 201, which is rotated, and (3) Moving the cutting tool 101 away from the workpiece 201.

[0085] More precisely, the workpiece 201 is first rotated about an axis O2 and the cutting tool 101 is brought relatively close to the workpiece 201, as shown in Fig. Figure 16 shows that the workpiece 201 is then cut by bringing the cutting edge of the cutting tool 101 into contact with the workpiece 201, as shown in Fig. Figure 17 shows that the cutting tool 101 is then moved away from the workpiece 201, as shown in Figure 17. Fig. 18 shown.

[0086] In the present disclosure, the cutting tool 101 is brought into the vicinity of the workpiece 201 by moving the cutting tool 101 in a D1 direction in a state in which the axis O2 is fixed and the workpiece 201 is rotated about the axis O2. Fig. In step 17, the workpiece 201 is cut by bringing the cutting edge of the insert into contact with the workpiece 201, which is rotated. Fig. 18 The cutting tool 101 is moved away by moving the cutting tool 101 in a D2 direction in a state in which the workpiece 201 is rotated.

[0087] During the cutting process using the manufacturing method described in the present disclosure, the cutting tool 101 is brought into contact with the workpiece 201, or the cutting tool 101 is moved away from the workpiece 201 by moving the cutting tool 101 in each of the above-mentioned steps. However, it is not intended to be limited to this embodiment.

[0088] For example, in step (1), the workpiece 201 can be brought close to the cutting tool 101. Similarly, in step (3), the workpiece 201 can be moved away from the cutting tool 101. If the cutting process is to be continued, the step in which the cutting edge of the insert is brought into contact with different sections of the workpiece 201 can be repeated while the workpiece 201 is kept in rotation.

[0089] Representative examples of the material of workpiece 201 are carbon steel, alloy steel, stainless steel, cast iron and non-ferrous metals. REFERENCE MARK LIST 1 deployment 3 first area 5 second area 7 third area 7a first side surface 7b second side surface 7c Corner side surface 9 corner 11 first page 13 second page 15 cutting edge 15a first cutting edge 15b second cutting edge 15c Corner cutting edge 17 inclined surfaces 19 first inclined surface 21 second inclined surface 23 third inclined surface 25 recess part 25a Recess part 25b Recess part 27 fourth inclined surface 29 first section 31 second section 33 third section 35 first connecting section 37 second connecting section 39 third connecting section 41 Through hole 101 Cutting tool 103 bags 105 holders 107 screw 201 workpiece 203 machined product H Height from the first surface O1 Central axis S1 reference plane L1 Angle bisector L2 first imaginary line L3 second imaginary line L4 third imaginary line L5 fourth imaginary line L11 Length of the first inclined surface L21 Length of the second inclined surface L22 Length of the second inclined surface L31 Length of the third inclined surface L32 Length of the third inclined surface L41 Length of the pair of recess parts L42 Length of the recess part L43 Length of the recess part L44 Length of the recess part L45 Length of the recess part W Width of the first area θ1 first angle θ2 second angle θ3 third angle θ4 fourth angle< / schneidwerkzeuge>

Claims

[1] A cutting insert (1) comprising: a first surface (3) having a corner (9) with a convex-curved shape in an outward direction and a first side (11) and a second side (13) extending each from the corner (9), a second surface (5) which is arranged on one of the sides opposite the first surface (3), and a third surface (7) arranged between the first surface (3) and the second surface (5), wherein an imaginary plane that is orthogonal to a central axis (O1) passing through a center point of the first surface (3) and a center point of the second surface (5), and is arranged between the first surface (3) and the second surface (5), is assumed to be the reference plane, the first surface (3) further has an inclined surface (17) which approaches the reference plane with increasing distance from the corner (9), the inclined surface (17) a first inclined surface (19) which is inclined at a first angle (θ1), a second inclined surface (21) which is arranged further away from the corner (9) than the first inclined surface (19) and is inclined at a second angle (θ2), and a third inclined surface (23) which is arranged further away from the corner (9) than the second inclined surface (21) and is inclined at a third angle (θ3), the first inclined surface (19) has a concave-curved shape in a cross-section orthogonal to an angle bisector (L1) of the corner (9), the second inclined surface (21) is a flat surface, and, in a cross-section that includes the angle bisector (L1) of the corner (9) and is orthogonal to the reference plane, the second angle (θ2) is smaller than the first angle (θ1) and the third angle (θ3), wherein in a top view of the first surface (3) a length (L32) of the third inclined surface (23) in a direction orthogonal to the angle bisector (L1) of the corner (9) is greater than a length (L22) of the second inclined surface (21) in the direction orthogonal to the angle bisector (L1) of the corner (9). [2] A cutting insert (1) comprising: a first surface (3) having a corner (9) with a convex-curved shape in an outward direction and a first side (11) and a second side (13) extending each from the corner (9), a second surface (5) which is arranged on one of the sides opposite the first surface (3), and a third surface (7) arranged between the first surface (3) and the second surface (5), wherein an imaginary plane that is orthogonal to a central axis (O1) passing through a center point of the first surface (3) and a center point of the second surface (5), and is arranged between the first surface (3) and the second surface (5), is assumed to be the reference plane, the first surface (3) further has an inclined surface (17) which approaches the reference plane with increasing distance from the corner (9), the inclined surface (17) a first inclined surface (19) which is inclined at a first angle (θ1), a second inclined surface (21) which is arranged further away from the corner (9) than the first inclined surface (19) and is inclined at a second angle (θ2), and a third inclined surface (23) which is arranged further away from the corner (9) than the second inclined surface (21) and is inclined at a third angle (θ3), the first inclined surface (19) has a concave-curved shape in a cross-section orthogonal to an angle bisector (L1) of the corner (9), the second inclined surface (21) is a flat surface, and, in a cross-section that includes the angle bisector (L1) of the corner (9) and is orthogonal to the reference plane, the second angle (θ2) is smaller than the first angle (θ1) and the third angle (θ3), wherein in a top view of the first surface (3) a length (L21) of the second inclined surface (21) in a direction along the angle bisector (L1) of the corner (9) is greater than a length (L11) of the first inclined surface (19) in the direction along the angle bisector (L1) of the corner (9). [3] A cutting insert (1) comprising: a first surface (3) having a corner (9) with a convex-curved shape in an outward direction and a first side (11) and a second side (13) extending each from the corner (9), a second surface (5) which is arranged on one of the sides opposite the first surface (3), and a third surface (7) arranged between the first surface (3) and the second surface (5), wherein an imaginary plane that is orthogonal to a central axis (O1) passing through a center point of the first surface (3) and a center point of the second surface (5), and is arranged between the first surface (3) and the second surface (5), is assumed to be the reference plane, the first surface (3) further has an inclined surface (17) which approaches the reference plane with increasing distance from the corner (9), the inclined surface (17) a first inclined surface (19) which is inclined at a first angle (θ1), a second inclined surface (21) which is arranged further away from the corner (9) than the first inclined surface (19) and is inclined at a second angle (θ2), and a third inclined surface (23) which is arranged further away from the corner (9) than the second inclined surface (21) and is inclined at a third angle (θ3), the first inclined surface (19) has a concave-curved shape in a cross-section orthogonal to an angle bisector (L1) of the corner (9), the second inclined surface (21) is a flat surface, and, in a cross-section that includes the angle bisector (L1) of the corner (9) and is orthogonal to the reference plane, the second angle (θ2) is smaller than the first angle (θ1) and the third angle (θ3), wherein in a top view of the first surface (3) the first surface (3) further has a pair of recess parts (25; 25a, 25b) between which the second inclined surface (21) is arranged in a direction perpendicular to the angle bisector (L1) of the corner (9). [4] The cutting insert (1) according to claim 3, wherein in the top view of the first surface (3) a length (L41) of the pair of recess parts (25) in the direction along the angle bisector (L1) of the corner (9) is greater than a length (L21) of the second inclined surface (5) in the direction along the angle bisector (L1) of the corner (9). [5] The cutting insert (1) according to claim 3 or 4, wherein in the top view of the first surface (3) one of the two recess parts (25b) which is arranged on one side of the second side (13) is arranged on a first imaginary straight line (L2) which passes through a boundary between the corner (9) and the first side (11) and is orthogonal to the first side (11). [6] A cutting insert (1) comprising: a first surface (3) having a corner (9) with a convex-curved shape in an outward direction and a first side (11) and a second side (13) extending each from the corner (9), a second surface (5) which is arranged on one of the sides opposite the first surface (3), and a third surface (7) arranged between the first surface (3) and the second surface (5), wherein an imaginary plane that is orthogonal to a central axis (O1) passing through a center point of the first surface (3) and a center point of the second surface (5), and is arranged between the first surface (3) and the second surface (5), is assumed to be the reference plane, the first surface (3) further has an inclined surface (17) which approaches the reference plane with increasing distance from the corner (9), the inclined surface (17) a first inclined surface (19) which is inclined at a first angle (θ1), a second inclined surface (21) which is arranged further away from the corner (9) than the first inclined surface (19) and is inclined at a second angle (θ2), and a third inclined surface (23) which is arranged further away from the corner (9) than the second inclined surface (21) and is inclined at a third angle (θ3), the first inclined surface (19) has a concave-curved shape in a cross-section orthogonal to an angle bisector (L1) of the corner (9), the second inclined surface (21) is a flat surface, and, in a cross-section that includes the angle bisector (L1) of the corner (9) and is orthogonal to the reference plane, the second angle (θ2) is smaller than the first angle (θ1) and the third angle (θ3), where the inclined surface (17) further comprises a fourth inclined surface (27) which is arranged between the first inclined surface (19) and the second inclined surface (21) and is inclined at a fourth angle (θ4), and in the cross-section that includes the angle bisector (L1) of the corner (9) and is orthogonal to the reference plane, the fourth angle (θ4) is smaller than the first angle (θ1) and larger than the second angle (θ2). [7] The cutting insert (1) according to claim 6, wherein in a top view of the first surface (3) a first imaginary line (L2) passing through the boundary between the corner (9) and the first side (11) and being orthogonal to the first side (11) intersects with a second imaginary line (L3) passing through a boundary between the corner (9) and the second side (13) and being orthogonal to the second side (13) on the fourth inclined surface (27). [8] The cutting insert (1) according to any one of claims 1 to 7, wherein the first angle (θ1) is larger than the third angle (θ3). [9] The cutting insert (1) according to any one of claims 1 to 8, wherein the third inclined surface (23) is a flat surface. [10] The cutting insert (1) according to any one of claims 1 to 9, wherein in a top view of the first surface (3) a length (L31) of the third inclined surface (23) in a direction along the angle bisector (L1) of the corner (9) is greater than a length (L21) of the second inclined surface (21) in the direction along the angle bisector (L1) of the corner (9). [11] The cutting insert (1) according to any one of claims 1 to 10, further comprising a corner cutting edge (15c) located at the corner (9), wherein the height of the corner cutting edge (15c) from the reference plane increases with increasing distance from the first side (11) and the second side (13). [12] A cutting tool (101) comprising: a holder (105) having a rod shape extending from a first end to a second end, and having a pocket (103) arranged on one side of the first end, and the cutting insert (1) according to any one of claims 1 to 11, wherein the cutting insert (1) is arranged in the pocket (103). [13] A method for producing a machine-made product, comprising: Turning a workpiece (201), Bringing the cutting tool (101) according to claim 12 into contact with the workpiece (201), which is rotated, and Moving the cutting tool (101) away from the workpiece (201).

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