Cutting insert, cutting tool, and method of manufacturing a workpiece

Abstract

The cutting insert can have an upper surface, a lower surface, a side surface, and a cutting edge. The upper surface can have a first corner, a first edge, a second edge, and a rake surface. The cutting edge can be located at an intersection of the upper surface and the side surface. The cutting edge can have a first cutting edge located at the first corner and a second cutting edge located at the first edge. The first cutting edge can have a first portion. The first portion can be located between a center of the first corner and the first edge and approach a reference plane as it moves away from the first edge. The rake surface can have a first region disposed along the first portion. A rake angle of the first region can decrease as it approaches the center of the first corner.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to Japanese Patent Application No. 2020-091489 filed May 26, 2020, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to a cutting insert used in general in cutting processing of a workpiece. As the cutting processing, for example, milling processing and turning processing can be cited. As the turning processing, for example, outer diameter processing, inner diameter processing, and face processing, and the like can be cited. BACKGROUND

[0004] As the cutting insert used in cutting processing of a workpiece, for example, the cutting inserts described in Japanese Patent Application Publication No. 2000-107911 (Patent Literature 1) and Japanese Patent Application Publication No. 2019-517930 (Patent Literature 2) can be cited. Both the cutting inserts described in Patent Literatures 1 and 2 have an upper surface provided with an acute corner. As an internal angle of the acute corner, various values can be set.

[0005] In a case where the internal angle of the acute corner is a small value (for example, about 30°), it is possible to reduce the durability of the acute corner. Therefore, at the time of cutting processing, it is necessary to reduce, for example, the feed rate and the like as a countermeasure. However, in order to increase the efficiency of the cutting processing, it is also required to increase the feed rate. That is, in order to increase the efficiency of the cutting processing, improvement of the durability of the acute corner becomes a problem. SUMMARY

[0006] The cutting insert of an aspect of the present disclosure, which is not limited, can have an upper surface, a lower surface, a side surface, and a cutting edge. The upper surface can have a first corner of a convex curved shape, and a first edge and a second edge connected to the first corner, respectively. The lower surface can be located on the opposite side of the upper surface. The side surface can be located between the upper surface and the lower surface. The cutting edge can be located at the intersection of the upper surface and the side surface. A notional straight line passing through the center of the upper surface and the center of the lower surface is a center axis. A notional plane located between the upper surface and the lower surface and orthogonal to the center axis is a reference surface. The cutting edge can have a first cutting edge located at the first corner and a second cutting edge located at the first edge. The first cutting edge can have a first portion. The first portion can be located between the center of the first corner and the first edge, and approach the reference surface as it moves away from the first edge. The upper surface can further have a rake surface disposed along the cutting edge. The rake surface can have a first region disposed along the first portion. The rake angle of the first region can decrease as it approaches the center of the first corner. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1is a perspective view of the cutting insert showing an embodiment not limited.

[0008] Figure 2 is a perspective view of the cutting insert showing an embodiment not limited. Figure 1 is an enlarged view of the area Al shown in

[0009] Figure 3 is a plan view of the upper surface of the cutting insert shown in Figure 1

[0010] Figure 4 is an enlarged view of the area A2 shown in Figure 3

[0011] Figure 5 is a side view of the cutting insert shown in Figure 4

[0012] Figure 6 is a side view of the cutting insert shown in Figure 4

[0013] Figure 7 is a side view of the cutting insert shown in Figure 4

[0014] Figure 8 is an enlarged view of the same area as shown in Figure 4

[0015] Figure 9 is a sectional view of the IX cross section in the cutting insert shown in Figure 8

[0016] Figure 10 is a sectional view of the X cross section in the cutting insert shown in Figure 8

[0017] Figure 11 is a sectional view of the XI cross section in the cutting insert shown in Figure 8

[0018] Figure 12 is a sectional view of the XII cross section in the cutting insert shown in Figure 8

[0019] Figure 13 is a sectional view of the XIII cross section in the cutting insert shown in Figure 8

[0020] Figure 14 is a perspective view of the cutting insert showing an embodiment not limited.

[0021] Figure 15 is a perspective view of the cutting insert showing an embodiment not limited. Figure 14 ​​​​​​​​​​​A side view of the cutting tool.

[0022] Figure 16 is a schematic view showing a step in a manufacturing method of a cutting workpiece of an unqualified embodiment.

[0023] Figure 17 is a schematic view showing a step in a manufacturing method of a cutting workpiece of an unqualified embodiment.

[0024] Figure 18 is a schematic view showing a step in a manufacturing method of a cutting workpiece of an unqualified embodiment. DETAILED DESCRIPTION

[0025] An unqualified aspect of the present disclosure, a cutting insert 1 (hereinafter, simply referred to as an insert 1), is explained in detail using the accompanying drawings. However, in each of the drawings referred to below, for the convenience of explanation, only the main components necessary for explaining the unqualified embodiment are simply shown. Thus, the insert 1 can be provided with any constituting components not shown in each of the drawings referred to. In addition, the dimensions of the components in each of the drawings do not necessarily represent the actual dimensions of the constituting components and the dimensional ratios of the components, and the like.

[0026]

[0027] The insert 1 can also have an upper surface 3, a lower surface 5, a side surface 7, and a cutting edge 9 as in the unqualified example shown in Figure 1

[0028] The upper surface 3 can be a polygonal shape. As in the unqualified example shown in Figure 3 The upper surface 3 can be a quadrangular shape. The upper surface 3 can also have a plurality of corners and a plurality of sides. As in the unqualified example shown in Figure 3 The upper surface 3 can also have four corners and four sides.

[0029] One of the plurality of corners can be a first corner 11. The first corner 11 can also be an acute angle in the case of observing the upper surface 3 in a front view. Note that in the explanation below, the observation of the upper surface 3 in a front view can also be referred to as a plan view. The size of the first corner 11 is not limited to a particular value. For example, the first corner 11 can be set to 20° to 85°. In particular, the first corner 11 can be set to a value as small as 20° to 40°.

[0030] ​​Two of the multiple sides extending from the first angle 11 can be a first side 13 and a second side 15. That is, the upper surface 3 can have a first angle 11 and a first side 13 and a second side 15 respectively connected to the first angle 11. It should be noted that the upper surface 3 is not limited to a quadrilateral. For example, it is perfectly acceptable for the upper surface 3 to be a triangle, a pentagon, or a hexagon.

[0031] The polygonal shapes mentioned above are not strictly limited to polygonal shapes. For example... Figure 4 As shown in the undefined example, when viewed from above, the corners can also be rounded, in other words, curved shapes that bulge outwards. Furthermore, when viewed from above, the four sides are not necessarily strictly straight. For example, when viewed from above, the four sides can be slightly bulging outwards or slightly concave.

[0032] It should be noted that when the angle has a rounded shape, the angle between the two imaginary lines extended from the two sides that sandwich the angle can also be considered an interior angle when viewed from above. For example, when the first angle 11 has a rounded shape, the angle between the two imaginary lines extended from the first side 13 and the second side 15 can also be considered an interior angle when viewed from above. Furthermore, when the two sides are not straight lines, the tangents at the ends of these sides that are tangent to the angle can also be considered as the aforementioned imaginary lines.

[0033] The lower surface 5 can be located on the opposite side of the upper surface 3. The lower surface 5 can have the same shape as the upper surface 3, or it can have a different shape. The lower surface 5 can also be a polygonal shape, just like the upper surface 3. If both the upper surface 3 and the lower surface 5 are polygonal, the lower surface 5 can also have a shape similar to the upper surface 3.

[0034] For example, the lower surface 5 can also be a shape that is slightly smaller than the upper surface 3. The lower surface 5 can be parallel to the upper surface 3, or it can be inclined relative to the upper surface 3. The lower surface 5 can also function as an abutting surface that abuts against the tool holder when the blade 1 is mounted on the tool holder.

[0035] Side surface 7 can be located between the upper surface 3 and the lower surface 5. Side surface 7 can be connected to the upper surface 3, or it can be separate from the upper surface 3. Similarly, side surface 7 can be connected to the lower surface 5, or it can be separate from the lower surface 5. If the corners of the upper surface 3 are rounded, the portion of side surface 7 connecting to the corners can also be a convex curved surface. Furthermore, if the edges of the upper surface 3 are straight, the portion of side surface 7 connecting to the edges can also be a flat surface.

[0036] For example, if the upper surface 3 has four rounded corners and four straight edges, the side surface 7 may also have four convex curved areas and four flat areas. It should be noted that in this disclosure, "flat" means not a curved surface. That is, "flat" is not necessarily limited to being parallel to or horizontal to the upper surface 3.

[0037] Furthermore, in this disclosure, "flat" does not require a strictly plane. An unavoidable degree of unevenness is permissible in the manufacture of the blade 1. Specifically, an unevenness with a surface roughness of 0.5 μm is also permissible.

[0038] Side 7 can extend in a direction orthogonal to the upper surface 3 and the lower surface 5, or it can be inclined relative to the upper surface 3 and the lower surface 5. For example, when the lower surface 5 is a shape that is slightly smaller than the upper surface 3, side 7 can also be... Figures 5-7 As shown in the undefined example, it tilts towards the central axis O1 as it moves away from the upper surface 3 and closer to the lower surface 5. Here, the aforementioned central axis O1 can also be an imaginary straight line passing through the center of the upper surface 3 and the center of the lower surface 5.

[0039] The cutting edge 9 can also be located at the junction of the upper surface 3 and the side surface 7. In other words, the cutting edge 9 can also be located at the outer periphery of the upper surface 3. The cutting edge 9 can also be used to cut the workpiece when machining it for manufacturing a workpiece. The cutting edge 9 can be located entirely at the junction of the upper surface 3 and the side surface 7, or it can be located only at a portion of the junction of the upper surface 3 and the side surface 7.

[0040] Cutting edge 9 can be like Figure 2 As shown in the undefined example, it has a first cutting edge 17 located at the first corner 11 and a second cutting edge 19 located at the first side 13. Alternatively, the cutting edge 9 may also have a third cutting edge 20 located at the second side 15. If the first corner 11 is rounded, the first cutting edge 17 may also be a convex curve shape. Furthermore, if the first side 13 is a straight line, the second cutting edge 19 may also be a straight line shape.

[0041] Honing can also be applied to the portion where the upper surface 3 and the side surface 7 meet and where the cutting edge 9 is located. That is, the junction between the upper surface 3 and the side surface 7 may not be a strictly linear shape formed by the intersection of two surfaces. In the case where the junction is not a strictly linear shape but is honed, the durability of the cutting edge 9 is improved. For example, a rounded honing process that forms a curved surface can also be applied to the portion where the upper surface 3 and the side surface 7 meet and where the cutting edge 9 is located.

[0042] like Figure 6As an example not limited to be shown, the first cutting edge 17 can be composed of a plurality of portions. For example, the first cutting edge 17 can have a first portion 17a. The first portion 17a can be located between the center 11a of the first corner 11 and the first edge 13, and approach the reference surface S1 as it is distanced from the first edge 13. Here, it can also be that an imaginary plane located between the upper surface 3 and the lower surface 5 and orthogonal to the center axis O1 is the reference surface S1.

[0043] It can be that the entirety of the portion of the first cutting edge 17 located between the center 11a of the first corner 11 and the first edge 13 is the first portion 17a, and it can also be that only a portion of the portion located between the center 11a of the first corner 11 and the first edge 13 is the first portion 17a.

[0044] As shown in the example not limited to be shown, the upper surface 3 can also have a rake face 21 disposed along the cutting edge 9. The rake face 21 can also function as a surface for chip flow when a workpiece is machined. In addition, in the case where the upper surface 3 has the rake face 21, the side surface 7 can also have a relief face. Figure 4

[0045] The rake face 21 can be connected to the cutting edge 9, but is not limited to a structure strictly connected to the cutting edge 9. For example, a region generally called a land face having a narrow width can be located between the rake face 21 and the cutting edge 9.

[0046] The rake face 21 can approach the reference surface S1 as it is distanced from the cutting edge 9. In other words, the rake face 21 can be inclined downward as it is distanced from the cutting edge 9. Here, it can also be that the inclination angle of the rake face 21 with respect to the reference surface S1 is a rake angle Θ. The magnitude of the rake angle Θ is not limited to a particular value. For example, the rake angle Θ can be set to 3° to 25°. The rake angle Θ can also be evaluated by, for example, the following procedure.

[0047] First, a measured object point in the cutting edge 9 is determined. Next, in the case of plan view, a cross section orthogonal to the cutting edge 9 at the object point is shown. In the cross section, the reference surface S1 and the rake face 21 are respectively shown by lines, and thus the angle at which these lines intersect is measured. This angle is the rake angle Θ. Note that in the case where the rake face 21 is not flat, the rake face 21 is shown in a curved shape in the above cross section. In this case, in the above cross section, it can also be that the maximum value of the inclination angle of the rake face 21 with respect to the reference surface S1 is the rake angle Θ.

[0048] ​The rake face 21 can have a first region 21a disposed along the first portion 17a. At this time, the rake angle Θ in the first region 21a can be made smaller as it approaches the center 11a of the first corner 11. When viewed from above, the width of the insert 1 in the direction orthogonal to the bisector of the corner of the first corner 11 is made narrower as it approaches the center 11a of the first corner 11. Therefore, the strength of the insert 1 is likely to be reduced as it approaches the center 11a of the first corner 11.

[0049] In the case where the rake angle Θ of the first region 21a is made smaller as it approaches the center 11a of the first corner 11, the wall thickness of the insert 1 is likely to be made larger as it approaches the center 11a of the first corner 11. Therefore, it is possible to improve the durability of the insert 1 at the center 11a of the first corner 11. As a result, it is possible to achieve high efficiency of cutting.

[0050] Whether or not the rake angle Θ of the first region 21a is made smaller as it approaches the center 11a of the first corner 11 can be evaluated by the following procedure. First, four points disposed at equal intervals in the first portion 17a are set as the object points for measurement. Next, cross sections orthogonal to the cutting edge 9 at these four object points are shown respectively as Figure 9 indicated in the example not limited as shown when viewed from above. Also, the rake angle Θ is measured at each of these four cross sections.

[0051] In the case where the rake angle Θ of the four cross sections is compared, when the rake angle Θ is made smaller as it approaches the center 11a of the first corner 11, the portion of the rake face 21 disposed along the portion sandwiched by the four object points in the first portion 17a is the first region 21a. Then, it is possible to evaluate that the rake angle Θ in this first region 21a is made smaller as it approaches the center 11a of the first corner 11. The difference between the minimum value and the maximum value of the rake angle Θ of the first region 21a can be, for example, 2° or more.

[0052] The first cutting edge 17 can have at least one of the second portion 17b, the third portion 17c, the fourth portion 17d, and the fifth portion 17e described in detail below in addition to the first portion 17a. That is, the first cutting edge 17 can have any one of the second portion 17b, the third portion 17c, the fourth portion 17d, or the fifth portion 17e, and can also have two or more of the second portion 17b, the third portion 17c, the fourth portion 17d, and the fifth portion 17e.

[0053] In addition, the rake face 21 can have at least one of the second region 21b, the third region 21c, the fourth region 21d, the fifth region 21e, and the sixth region 21f in addition to the first region 21a, as described in detail below. That is, the rake face 21 can have any one of the second region 21b, the third region 21c, the fourth region 21d, the fifth region 21e, or the sixth region 21f, and can also have two or more of the second region 21b, the third region 21c, the fourth region 21d, the fifth region 21e, and the sixth region 21f.

[0054] The second site 17b can be located between the first site 17a and the first edge 13. At this time, the second site 17b can be away from the reference surface S1 as it is away from the first edge 13. The second region 21b can be disposed along the second site 17b. Also, as shown in the example of the unillustrated embodiment, the rake angle Θ of the second region 21b is evaluated. At this time, the rake angle Θ of the second region 21b can be made larger as it is closer to the first site 17a. Figure 10

[0055] The second site 17b located closer to the first edge 13 than the first site 17a can serve as a so-called finishing edge. In the case where the rake angle Θ in the second region 21b is made larger as it is closer to the first site 17a, the machinability of the second site 17b can be improved. Thus, the surface accuracy of the machined surface in the workpiece can be improved. In other words, the surface roughness of the machined surface can be reduced.

[0056] Whether or not the rake angle Θ in the second region 21b is made larger as it is closer to the first site 17a is the same as the evaluation of the rake angle Θ in the first region 21a, and the rake angle Θ is evaluated as long as four points disposed at equal intervals are set as the measured object points. The difference between the minimum value and the maximum value of the rake angle Θ of the second region 21b can be, for example, 0.1° or more.

[0057] The second cutting edge 19, as shown in the example of the unillustrated embodiment, in the case where it is away from the reference surface S1 as it is closer to the first cutting edge 17, can improve the durability of the cutting edge 9 as long as the second site 17b is away from the reference surface S1 as it is away from the first edge 13. Figure 6

[0058] This is because the change in the extension direction of the cutting edge 9 is small in the vicinity of the boundary between the first cutting edge 17 and the second cutting edge 19. In the case where the change in the extension direction of the cutting edge 9 is small, the direction of the cutting load applied to each site of the cutting edge 9 does not easily change drastically. The cutting load tends to concentrate in the vicinity of the boundary between the first cutting edge 17 and the second cutting edge 19, but in the case where the cutting edge 9 has the above-described structure, the direction of the cutting load does not easily change drastically, and thus the durability of the cutting edge 9 can be improved.

[0059] ​​The third position 17c can be located at a position including the center 11a of the first corner 11. At this time, one of the two ends of the third position 17c can be located at the center 11a of the first corner 11, or the center 11a of the first corner 11 can be located between the two ends of the third position 17c. The third region 21c can also be arranged along the third position 17c. Also, as shown in the example of the unillustrated third region 21c, the rake angle θ of the third region 21c is evaluated. Figure 11

[0060] At this time, the rake angle θ of the third region 21c can be smaller than the rake angle θ of the first region 21a. More specifically, the minimum value of the rake angle θ of the third region 21c can be smaller than the minimum value of the rake angle θ of the first region 21a.

[0061] As described above, the strength of the blade 1 tends to decrease as it approaches the center 11a of the first corner 11. In the case where the rake angle θ of the third region 21c arranged along the third position 17c is smaller than the rake angle θ of the first region 21a, the strength of the blade 1 at the vicinity of the center 11a of the first corner 11 can be improved. Thus, the durability of the blade 1 at the center 11a of the first corner 11 can be further improved. As a result, further efficiency of the cutting process can be achieved.

[0062] In the case where the rake face 21 has the third region 21c, the third region 21c can be curved, or it can be flat. In the case where the third region 21c is flat, the strength of the blade 1 at the vicinity of the center 11a of the first corner 11 can be further improved. Thus, the durability of the blade 1 at the center 11a of the first corner 11 can be further improved.

[0063] The fourth position 17d can be located between the center 11a of the first corner 11 and the second edge 15. At this time, the fourth position 17d can approach the reference face S1 as it moves away from the second edge 15. The fourth region 21d can be arranged along the fourth position 17d. Also, as shown in the example of the unillustrated fourth region 21d, the rake angle θ of the fourth region 21d is evaluated. At this time, the rake angle θ of the fourth region 21d can decrease as it approaches the center 11a of the first corner 11. Figure 12

[0064] In the case where the blade 1 further has such a fourth position 17d and a fourth region 21d, the versatility of the blade 1 can be improved. For example, in the case where the third cutting edge 20 and the fourth position 17d are used for the cutting process, the durability of the blade 1 at the center 11a of the first corner 11 can be high, and the efficiency of the cutting process can be improved, as in the case where the second cutting edge 19 and the first position 17a are used for the cutting process. Thus, the cutting process for both right-hand and left-hand cuts can be addressed.

[0065] ​​The fifth site 17e can be located between the fourth site 17d and the second edge 15. In this case, the fifth site 17e is away from the reference surface S1 as it is away from the second edge 15. The fifth region 21e can also be arranged along the fifth site 17e. Also, the rake angle Θ of the fifth region 21e is evaluated as an example not limited as shown. Figure 13 In this case, the rake angle Θ of the fifth region 21e can be made larger as it is closer to the fourth site 17d.

[0066] The fifth site 17e located closer to the second edge 15 than the fourth site 17d can be used as a so-called finishing edge, like the second site 17b. In the case where the rake angle Θ of the fifth region 21e is made larger as it is closer to the fourth site 17d, the cutting performance of the fifth site 17e can be improved. Therefore, the surface accuracy of the machined surface in the workpiece can be improved. In other words, the surface roughness of the machined surface can be reduced.

[0067] In the case where the insert 1 has both the second site 17b and the fifth site 17e as described above, the surface accuracy of the machined surface in the workpiece can be improved in either of the right-hand cutting and the left-hand cutting described above.

[0068] The first region 21a can be curved, or alternatively, flat. In the case where the first region 21a is flat, the strength of the insert 1 in the vicinity of the first site 17a can be improved. Therefore, the durability of the insert 1 can be further improved.

[0069] The sixth region 21f can also be arranged along the second cutting edge 19. Here, the sixth region 21f can be curved, or alternatively, flat. In the case where the sixth region 21f is flat, the chips generated by the second cutting edge 19 can easily travel on the sixth region 21f. Therefore, the chip discharge performance can be improved.

[0070] Here, the first region 21a and the sixth region 21f can be flat and located on the same plane, respectively. In this case, the chips generated by the first site 17a can easily travel from the first region 21a to the sixth region 21f. The chips generated by the first site 17a can easily become thin compared to the chips generated by the sixth region 21f, and thus the flow of the chips can easily become unstable. However, the chips generated by the first site 17a can easily travel from the first region 21a to the sixth region 21f, and thus the chip discharge performance can be further improved.

[0071] The insert 1 can also be as shown in Figure 1As shown in the undefined example, it has a through hole 23 opening on the upper surface 3 and the lower surface 5. The central axis of the through hole 23 may also coincide with the central axis O1 of the blade 1. The through hole 23 can be used to insert a screw, for example, when fixing the blade 1 to the tool holder. When fixing the blade 1 to the tool holder, a clamping member may also be used, for example, instead of a screw.

[0072] The size of the blade 1 is not particularly limited. For example, the length of one side of the polygonal upper surface 3 can be set to about 10 to 25 mm. In addition, the height from the upper surface 3 to the lower surface 5, in other words, the height along the central axis O1, can be set to about 2 to 5 mm.

[0073] Materials for the cutting tool 1 can include, for example, cemented carbide and cermet. Compositions of cemented carbide can include, for example, WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. Here, WC, TiC, and TaC can be hard particles, and Co can be a binder phase.

[0074] Furthermore, cermets can be sintered composite materials formed by combining metal and ceramic components. Specifically, as an example of a cermet, titanium compounds with titanium carbide (TiC) or titanium nitride (TiN) as the main components can be listed. However, the material of blade 1 is not limited to the above-mentioned composition.

[0075] The surface of the blade 1 can be coated using chemical vapor deposition (CVD) or physical vapor deposition (PVD) with a film. Examples of suitable film compositions include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al2O3).

[0076] <Cutting Tools>

[0077] Next, the cutting tool 101, which is not limited to any aspect of this disclosure, will be described with reference to the accompanying drawings.

[0078] Cutting tool 101 can also be like Figure 14 as well as Figure 15 The example shown, which is not limited to this one, has a tool holder 105 extending from a first end 105a toward a second end 105b. The tool holder 105 may also have a tool groove 103 (insert groove) on one side of the first end 105a. The cutting tool 101 may also have the aforementioned insert 1 located in the tool groove 103. In the cutting tool 101, the insert 1 is mounted such that at least a portion of the cutting edge 9 protrudes from the first end 105a of the tool holder 105.

[0079] The handle 105 can also be in the shape of a long, thin rod. Furthermore, a cutting groove 103 can be provided on one side of the first end 105a of the handle 105. The cutting groove 103 can also be a portion for mounting the blade 1, and it opens opposite to the end face of one side of the first end 105a in the handle 105. In this case, with the cutting groove 103 also opening opposite to the side of the handle 105, the blade 1 can be easily mounted.

[0080] The tool groove 103 may also have a seat surface that is substantially parallel to the lower surface of the tool holder 105 and a constraint side that is inclined relative to the seat surface.

[0081] The blade 1 can also be located in the blade groove 103. In this case, the lower surface 5 of the blade 1 can be directly connected to the blade groove 103. Alternatively, a sheet can be sandwiched between the blade 1 and the blade groove 103.

[0082] like Figure 14 As in the undefined example shown, the blade 1 can also be fixed to the shank 105 by a screw 107. For example, a screw hole may be provided in the shank, the screw 107 may be inserted into the through hole 23 of the blade 1, and the screw 107 may be fixed by the screw hole, thereby constraining the blade 1 to the groove 103.

[0083] It should be noted that, alternatively, the blade 1 can be fixed to the shank 105 by a clamping member. That is, the blade 1 can also be constrained in the groove 103 by pressing the head of the clamping member against the inner wall of the through hole of the blade 1.

[0084] As components of the handle 105, steel, cast iron, etc., can also be used. In particular, when steel is used in these components, the handle 105 has high toughness.

[0085] In an undefined embodiment, a cutting tool used in so-called turning is illustrated. Examples of turning include internal diameter machining, external diameter machining, and end face machining. It should be noted that the cutting tool is not limited to those used in turning. For example, the insert 1 described above can also be used as a cutting tool in turning operations.

[0086] <Methods for Manufacturing Machined Workpieces>

[0087] Next, the method for manufacturing a machined object with an undefined side in this disclosure will be described using the accompanying drawings.

[0088] The workpiece 203 can be manufactured by machining the workpiece 201. The manufacturing method of the workpiece 203 in this embodiment includes the following steps:

[0089] (1) The process of rotating the workpiece 201;

[0090] (2) A process of bringing the cutting tool 101, as exemplified in the above embodiment, into contact with the rotating workpiece 201; and

[0091] (3) The process of separating the cutting tool 101 from the workpiece 201.

[0092] More specifically, firstly, such as Figure 16 As shown in the undefined example, the workpiece 201 can be rotated about axis O2, and the workpiece 201 can be brought relatively close to the cutting tool 101. Next, as... Figure 17 As shown in the undefined example, at least a portion of the cutting edge 9 in the cutting tool 101 can be brought into contact with the workpiece 201 to cut it. Then, as... Figure 18 As shown in the undefined example, the cutting tool 101 can be moved relatively away from the workpiece 201.

[0093] like Figure 16 As shown in the undefined example, the cutting tool 101 can be moved in the Y1 direction while the shaft O2 is fixed and the workpiece 201 is rotated, thereby bringing the cutting tool 101 closer to the workpiece 201.

[0094] In addition, such as Figure 17 As shown in the undefined example, the workpiece 201 can be cut by moving the cutting tool 101 in the Y2 direction while at least a portion of the part of the insert 1 used as the cutting edge 9 is in contact with the rotating workpiece 201.

[0095] In addition, such as Figure 18 As shown in the undefined example, the cutting tool 101 can be moved away from the workpiece 201 by moving the cutting tool 101 in the Y3 direction while the workpiece 201 is being rotated.

[0096] It should be noted that the cutting tool 101 is moved in each process, so that the cutting tool 101 comes into contact with the workpiece 201 or moves away from the workpiece 201, but of course it is not limited to this method.

[0097] 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. In the case of continuous cutting, the workpiece 201 may be kept in a state of rotation, and the steps of bringing at least a portion of the cutting edge 9 in the insert 1 into contact with different positions of the workpiece 201 may be repeated.

[0098] Note that, as a representative example of the material of the workpiece 201, quenched steel, carbon steel, alloy steel, stainless steel, cast iron, or a non-ferrous metal, etc. can be listed.

[0099] Reference Signs

[0100] 1 • • • cutting insert (insert)

[0101] 3 • • • upper surface

[0102] 5 • • • lower surface

[0103] 7 • • • side surface

[0104] 9 • • • cutting edge

[0105] 11 • • • first corner

[0106] 11a • • • center

[0107] 13 • • • first edge

[0108] 15 • • • second edge

[0109] 17 • • • first cutting edge

[0110] 17a • • • first portion

[0111] 17b • • • second portion

[0112] 17c • • • third portion

[0113] 17d • • • fourth portion

[0114] 17e • • • fifth portion

[0115] 19 • • • second cutting edge

[0116] 20 • • • third cutting edge

[0117] 21 • • • rake surface

[0118] 21a • • • first region

[0119] 21b • • • second region

[0120] 21c • • • third region

[0121] 21d • • • fourth region

[0122] 21e • • • fifth region

[0123] 21f • • • sixth region

[0124] 23 • • • through hole

[0125] 101... cutting tool

[0126] 103... flute

[0127] 105... shank

[0128] 107... screw

[0129] 201... workpiece

[0130] 203... workpiece

[0131] 01... center axis

[0132] 02... axis

[0133] S1... reference surface

[0134] θ... rake angle

Claims

1. A cutting insert, wherein, The cutting blade has: The upper surface has a first corner with a convex curve shape, and a first side and a second side respectively connected to the first corner; The lower surface, which is located on the opposite side of the upper surface; The side, located between the upper surface and the lower surface; and The cutting edge is located at the junction of the upper surface and the side surface. The central axis is an imaginary straight line drawn through the center of the upper surface and the center of the lower surface. An imaginary plane located between the upper and lower surfaces and orthogonal to the central axis is used as a reference plane. The cutting edge has: The first cutting edge is located at the first angle; as well as The second cutting edge is located on the first side. The first cutting edge has a first portion located between the center of the first angle and the first side, and moving closer to the reference surface as it moves away from the first side. The upper surface also has a rake face arranged along the cutting edge. The rake face has a first region arranged along the first portion. The front corner of the first region decreases in size as it approaches the center of the first corner. The first cutting edge also has a third portion located at the center position including the first angle. The rake face also has a third region arranged along the third portion. The front angle of the third region is smaller than the front angle of the first region. The third region is flat.

2. The cutting insert according to claim 1, wherein, The first cutting edge further has a second portion located between the first portion and the first edge, and moving away from the reference surface as it moves away from the first edge. The rake face also has a second region arranged along the second portion. The front corner of the second region increases as it gets closer to the first part.

3. The cutting insert according to claim 1 or 2, wherein, The first cutting edge also has a fourth portion located between the center of the first angle and the second side, and moving closer to the reference surface as it moves away from the second side. The rake face also has a fourth region arranged along the fourth portion. The front corner of the fourth region decreases as it approaches the center of the first corner.

4. The cutting insert according to claim 3, wherein, The first cutting edge also has a fifth portion located between the fourth portion and the second side, and moving away from the reference surface as it moves away from the second side. The rake face also has a fifth region arranged along the fifth portion. The front corner of the fifth region increases as it approaches the fourth part.

5. The cutting insert according to claim 1 or 2, wherein, The first region is flat.

6. The cutting insert according to claim 5, wherein, The rake face also has a flat sixth region arranged along the second cutting edge. The first region and the sixth region are located on the same plane.

7. A cutting insert, wherein, The cutting blade has: The upper surface has a first corner with a convex curve shape, and a first side and a second side respectively connected to the first corner; The lower surface, which is located on the opposite side of the upper surface; The side, located between the upper surface and the lower surface; and The cutting edge is located at the junction of the upper surface and the side surface. The central axis is an imaginary straight line drawn through the center of the upper surface and the center of the lower surface. An imaginary plane located between the upper and lower surfaces and orthogonal to the central axis is used as a reference plane. The cutting edge has: The first cutting edge is located at the first angle; as well as The second cutting edge is located on the first side. The first cutting edge has a first portion located between the center of the first angle and the first side, and moving closer to the reference surface as it moves away from the first side. The upper surface also has a rake face arranged along the cutting edge. The rake face has a first region arranged along the first portion. The front corner of the first region decreases in size as it approaches the center of the first corner. The first region is flat.

8. A cutting tool, wherein, The cutting tool has: The handle is rod-shaped, extending from a first end toward a second end, and has a groove at the first end; and The cutting insert according to any one of claims 1 to 7, wherein it is located within the tool groove.

9. A method for manufacturing a workpiece by cutting, wherein, The method for manufacturing the workpiece includes: The process of rotating the workpiece; The process of bringing the cutting tool of claim 8 into contact with the rotating workpiece; and The process of separating the cutting tool from the workpiece.

Images