Rotary scraper

Abstract

The rotary scraper rotates about an axis. In the rotary scraper, a plurality of cutting edges are annularly arranged around the axis. The rotary blade has a base part and a blade tip part. The tool nose part is connected with the base body part. The blade tip portion is arranged side by side with the base portion in a first direction facing forward of the rotary blade along the axis. The base portion is formed of either a cemented carbide or a high-speed steel. The tool nose part comprises a tool nose layer and a hard alloy layer. The tip layer forms a plurality of cutting edges. The hard alloy layer is arranged between the tool nose layer and the base body part. And the tool nose layer is formed by any one of cubic boron nitride sintered body, diamond and special hard alloy.

Description

Technical Field

[0001] This disclosure relates to rotary scrapers. This application claims priority based on Japanese Patent Application No. 2024-081061, filed on May 17, 2024. The entire contents of that Japanese patent application are incorporated herein by reference. Background Technology

[0002] As an example of a rotary scraper, Japanese Patent Application Publication No. 2022-045081 (Patent Document 1) describes a rotary scraper in which an R-angle is machined at the tip of the cutting edge in a range with a radius of curvature of 20 μm or more and 40 μm or less.

[0003] Existing technical documents Patent documents Patent document 1: Japanese Patent Application Publication No. 2022-045081. Summary of the Invention

[0004] The rotary scraper disclosed herein rotates about an axis. In the rotary scraper, multiple cutting edges are arranged in a circular pattern about the axis. The rotary scraper has a base portion and a tip portion. The tip portion is connected to the base portion. The tip portion is arranged with the base portion in a first direction along the axis toward the front of the rotary scraper. The base portion is formed of either cemented carbide or high-speed steel. The tip portion includes a tip layer and a cemented carbide layer. The tip layer forms multiple cutting edges. The cemented carbide layer is disposed between the tip layer and the base portion. The tip layer is formed of either cubic boron nitride sintered body, diamond, or a special cemented carbide. The special cemented carbide has tungsten carbide particles and a bonding phase. The bonding phase includes cobalt. In the special cemented carbide, the percentage obtained by dividing the volume of the bonding phase by the total volume of the special cemented carbide is 0.7% or more and 28% or less. In the bonding phase, the percentage obtained by dividing the mass of cobalt by the total mass of the bonding phase is 50% or more. The combined phase also includes at least one element selected from the group consisting of silicon, phosphorus, germanium, tin, rhenium, ruthenium, osmium, iridium and platinum. Attached Figure Description

[0005] Figure 1 This is a perspective view showing the structure of the rotary scraper according to the first embodiment.

[0006] Figure 2 This is a top view schematic diagram showing the structure of the rotary scraper according to the first embodiment.

[0007] Figure 3 This is a bottom view schematic diagram showing the structure of the rotary scraper according to the first embodiment.

[0008] Figure 4 It is along Figure 2 A cross-sectional view of line IV-IV.

[0009] Figure 5 It means Figure 4 A magnified cross-sectional view of region V.

[0010] Figure 6 It means Figure 1 An enlarged 3D diagram of area VI.

[0011] Figure 7 It means Figure 2 An enlarged top view of region VII.

[0012] Figure 8 It means along Figure 2 A side view of the structure of the rotary scraper when viewed in the direction of the arrow.

[0013] Figure 9 This is a partial cross-sectional schematic diagram illustrating the scraping process using a rotary scraper.

[0014] Figure 10 This is a top view diagram illustrating the scraping process using a rotary scraper.

[0015] Figure 11 This is an enlarged cross-sectional schematic diagram showing the structure of the rotary scraper according to the second embodiment.

[0016] Figure 12 This is an enlarged bottom view schematic diagram showing the structure of the rotary scraper according to the second embodiment.

[0017] Figure 13 It is along Figure 12 A cross-sectional view of line XIII-XIII.

[0018] Figure 14 It is along Figure 12 A cross-sectional view of line XIV-XIV.

[0019] Figure 15 This is a first enlarged cross-sectional schematic diagram showing a modified example of the second embodiment.

[0020] Figure 16 This is a second enlarged cross-sectional schematic diagram showing a modified example of the second embodiment.

[0021] Figure 17 This is a cross-sectional schematic diagram showing the structure of the rotary scraper according to the third embodiment.

[0022] Figure 18 This is a perspective view showing the structure of the rotary scraper according to the fourth embodiment.

[0023] Figure 19This is a top view schematic diagram showing the structure of the rotary scraper according to the fourth embodiment.

[0024] Figure 20 This is a bottom view schematic diagram showing the structure of the rotary scraper according to the fourth embodiment.

[0025] Figure 21 It means Figure 20 A magnified diagram of region XXI.

[0026] Figure 22 It is along Figure 21 A cross-sectional view of the XXII-XXII line.

[0027] Figure 23 It is along Figure 21 A cross-sectional view of line XXIII-XXIII.

[0028] Figure 24 It means along Figure 19 A side view of the blade structure when viewed from the perspective of arrow E.

[0029] Figure 25 This is a perspective view showing the structure of the rotary scraper according to the fifth embodiment.

[0030] Figure 26 This is a cross-sectional schematic diagram showing the structure of the rotary scraper according to the fifth embodiment. Detailed Implementation

[0031] [The problem this disclosure aims to solve] According to the rotary scraper described in Patent Document 1, the cutting edge sometimes wears significantly because the front end of the cutting edge is chamfered.

[0032] The purpose of this disclosure is to provide a rotary scraper capable of suppressing wear on the cutting edge.

[0033] [The Effects of This Disclosure] According to this disclosure, a rotary scraper capable of suppressing wear on the cutting edge can be provided.

[0034] [Description of embodiments of this disclosure] First, embodiments of this disclosure will be described.

[0035] (1) The rotary scraper disclosed herein rotates about an axis. In the rotary scraper, a plurality of cutting edges are arranged in a ring about an axis. The rotary scraper has a base portion and a tip portion. The tip portion is connected to the base portion. The tip portion is arranged with the base portion in a first direction along the axis toward the front of the rotary scraper. The base portion is formed of either cemented carbide or high-speed steel. The tip portion includes a tip layer and a cemented carbide layer. The tip layer forms a plurality of cutting edges. The cemented carbide layer is disposed between the tip layer and the base portion. The tip layer is formed of either cubic boron nitride sintered body, diamond, or a special cemented carbide. The special cemented carbide has tungsten carbide particles and a bonding phase. The bonding phase includes cobalt. In the special cemented carbide, the percentage obtained by dividing the volume of the bonding phase by the total volume of the special cemented carbide is 0.7% or more and 28% or less. In the bonding phase, the percentage obtained by dividing the mass of cobalt by the total mass of the bonding phase is 50% or more. The bonding phase also includes at least one element selected from the group consisting of silicon, phosphorus, germanium, tin, rhenium, ruthenium, osmium, iridium, and platinum. This allows for the suppression of cutting edge wear.

[0036] (2) The rotary scraper described in (1) above may also have a shaft portion and multiple cutting edges. The shaft portion may also have an outer peripheral surface. The outer peripheral surface may also be arranged around an axis. Multiple cutting edges may also be connected to the shaft portion respectively. Multiple cutting edges may also extend radially outward from the outer peripheral surface respectively. Multiple cutting edges may also form one of multiple cutting edges. Multiple cutting edges may also have a first flank face and a second flank face respectively. The first flank face may also be formed by a blade tip portion. The first flank face may also be connected to multiple cutting edges. The second flank face may also be formed by a base portion. The second flank face may also be arranged in a second direction relative to the first flank face, the second direction being directed towards the rear of the rotary scraper along the axis. The blade tip portion may also have a first bottom face and a second bottom face. The first bottom face may also be connected to the base portion. The second bottom face may also be connected to both the first flank face and the first bottom face respectively. The second bottom face may also be arranged outward relative to the base portion. The edges of the first flank face and the second bottom face may also have a first edge portion, a corner edge portion, and a second edge portion. The corner edge portion can also be connected to the first edge portion. The corner edge portion can also be positioned radially outward relative to the first edge portion. The second edge portion can also be connected to the corner edge portion. The second edge portion can also be positioned in the direction of rotation relative to the first edge portion. In a cross-section perpendicular to the tangent of the first edge portion when viewed along the axis, if the length of the second bottom portion located between the first edge portion and the second rear cutting edge portion is defined as the first length, and in a cross-section perpendicular to the tangent of the second edge portion when viewed along the axis, if the length of the second bottom portion located between the second edge portion and the second rear cutting edge portion is defined as the second length, the first length can also be the same as the second length.

[0037] Therefore, when the chip thickness is substantially the same between two different points on the cutting edge, wear on the flank face can be effectively suppressed.

[0038] (3) The rotary scraper described in (1) above may also have a shaft portion and multiple cutting edges. The shaft portion may also have an outer peripheral surface. The outer peripheral surface may also be arranged around an axis. Multiple cutting edges may also be connected to the shaft portion respectively. Multiple cutting edges may also extend radially outward from the outer peripheral surface respectively. Multiple cutting edges may also form one of multiple cutting edges. Multiple cutting edges may also have a first flank face and a second flank face respectively. The first flank face may also be formed by a blade tip portion. The first flank face may also be connected to multiple cutting edges. The second flank face may also be formed by a base portion. The second flank face may also be arranged relative to the first flank face along a second direction, which is along the axis and faces the rear of the rotary scraper. The blade tip portion may also have a first bottom face and a second bottom face. The first bottom face may also be connected to the base portion. The second bottom face may also be connected to both the first flank face and the first bottom face respectively. The second bottom face may also be arranged on the outer side relative to the base portion. The edges of the first flank face and the second bottom face may also have a first edge portion, a corner edge portion, and a second edge portion. The corner edge portion may also be connected to the first edge portion. The corner edge portion may also be positioned radially outward relative to the first edge portion. The second edge portion may also be connected to the corner edge portion. The second edge portion may also be positioned in the direction of rotation relative to the first edge portion. In a cross-section perpendicular to the tangent of the first edge portion when viewed along the axis, the length of the second bottom portion located between the first edge portion and the second rear cutting edge portion is defined as the first length. In a cross-section perpendicular to the tangent of the second edge portion when viewed along the axis, the length of the second bottom portion located between the second edge portion and the second rear cutting edge portion is defined as the second length. The first length may also be different from the second length.

[0039] Therefore, when the chip thickness varies between two different points on the cutting edge, wear on the flank face can be effectively suppressed.

[0040] (4) According to the rotary scraper described in (2) or (3) above, the multiple cutting edges may each have a rake face and a rear face. The rake face may also be connected to multiple cutting edges. The rake face may also be formed by a tip layer. The rear face may also be located opposite to the rake face. The rear face may also be formed by a base portion. When viewed along the axis, the rear face may also overlap with the rake face.

[0041] (5) According to the rotary scraper described in (2) or (3) above, the multiple cutting edges may each have a rake face and a rear face. The rake face may also be connected to multiple cutting edges. The rake face may also be formed from a tip layer. The rear face may also be located opposite to the rake face. The rear face may also be formed from a base portion. When viewed along the axis, the rake face may also be positioned relative to the rear face in the direction of rotation.

[0042] (6) The blade scraper according to any one of (1) to (5) above may also have a brazing filler layer at the tip. The brazing filler layer may also be disposed on the base. The cemented carbide layer may also be disposed on the brazing filler layer.

[0043] (7) According to any one of (1) to (6) above, the maximum thickness of the blade tip layer in the first direction can be 0.3 mm or more and 3 mm or less. As a result, wear on the blade tip can be suppressed, and breakage of the blade tip can be suppressed.

[0044] (8) The rotary scraper described in any of (1) to (7) above may also have a coating. The coating may also cover at least a portion of the tip. This can suppress wear on the tip.

[0045] (9) According to any one of (1) to (8) above, in a cross section perpendicular to the multiple cutting edges, the radius of curvature of the multiple cutting edges can be more than 10 μm and less than 40 μm. As a result, it is possible to suppress defects in the portion of the rotary scraper near the cutting edge and to suppress excessive reduction in the sharpness of the cutting edge.

[0046] (10) According to any one of (1) to (9) above, the blade tip layer can also be formed from a cubic boron nitride sintered body. The cubic boron nitride sintered body can also contain cubic boron nitride particles. In the cubic boron nitride sintered body, the percentage obtained by dividing the volume of the cubic boron nitride particles by the total volume of the cubic boron nitride sintered body can also be 50% or more and 100% or less. In the cubic boron nitride sintered body, the average particle size of the cubic boron nitride particles can also be 0.01 μm or more and 3 μm or less. Thus, defects at the blade tip can be effectively suppressed.

[0047] (11) According to the rotary scraper described in (10) above, the percentage of the volume of cubic boron nitride particles divided by the total volume of the cubic boron nitride sintered body can also be less than 100%. The cubic boron nitride sintered body may also contain a bonding material. The bonding material may also contain at least one element selected from the group consisting of titanium, cobalt, aluminum, and zirconium. Thus, wear at the tip of the scraper can be effectively suppressed.

[0048] (12) The rotary scraper described in (1) above may also have a shaft and multiple cutting edges. The shaft may also have an outer peripheral surface. The outer peripheral surface may also be arranged around an axis. Multiple cutting edges may also be connected to the shaft respectively. Multiple cutting edges may also extend radially outward from the outer peripheral surface respectively. Multiple cutting edges may also form one of multiple cutting edges. Multiple cutting edges may also have a rake face and a flank face respectively. The rake face may also be connected to multiple cutting edges. The rake face may also be formed by a tip layer. The flank face may also be connected to the rake face via multiple cutting edges. In each of the multiple cutting edges, the point located at the outermost periphery when viewed along the axis may also be designated as the outermost periphery point. In each of the multiple cutting edges, in a cross section including the axis and passing through the outermost periphery point, the angle between the straight line perpendicular to the axis and the rake face may be 0° or more and 40° or less. In each of the multiple cutting edges, when viewed perpendicularly to the axis and from the outermost circumference towards the axis, the angle between the flank edge and the axis is 0° or more and 40° or less. This suppresses wear at the cutting tip.

[0049] (13) According to any of the rotary scrapers described in (1) to (12) above, the tip layer can also be formed of diamond. The diamond can also be polycrystalline diamond containing multiple diamond particles. In the diamond, the percentage obtained by dividing the volume of the multiple diamond particles by the total volume of the diamond can be more than 80% and less than 100%. As a result, it is possible to suppress the excessive reduction of the strength of the tip layer.

[0050] (14) According to the rotary scraper mentioned in (13) above, the average particle size of multiple diamond particles can also be 0.01 μm or more and less than 100 μm. Therefore, it is possible to suppress the excessive reduction of the strength of the blade tip layer.

[0051] (15) The tip layer can also be formed of diamond according to any of the rotary scrapers described in (1) to (12) above. The diamond can also be single-crystal diamond. This can improve the strength of the tip layer.

[0052] [Details of the embodiments disclosed herein] Next, the detailed embodiments of this disclosure will be described with reference to the accompanying drawings. It should be noted that in the following drawings, the same or equivalent parts will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0053] (First Implementation) First, the structure of the rotary scraper 100 according to the first embodiment will be described.

[0054] like Figure 1As shown, the rotary scraper 100 has multiple cutting edges 1, a shaft portion 10, and multiple cutting edges 6. The rotary scraper 100 rotates about an axis O. The multiple cutting edges 1 are arranged in a circular pattern around the axis O.

[0055] The shaft portion 10 is the part opposite to the tool spindle (not shown) that rotates the rotary scraper 100. The shaft portion 10 extends, for example, along axis O. A plurality of cutting edges 6 are connected to the shaft portion 10. The plurality of cutting edges 6 are arranged in a ring around axis O. The plurality of cutting edges 6 each form one of a plurality of cutting edges 1. From another viewpoint, in the rotary scraper 100, the number of cutting edges 1 is the same as the number of cutting edges 6.

[0056] The rotary scraper 100 is used, for example, for machining metallic materials. Specifically, the rotary scraper 100 is used, for example, for machining hardened steel. The rotary scraper 100 is also used, for example, for machining high-hardness materials. More specifically, it is used, for example, for machining high-hardness materials with a Rockwell hardness grade C (HRC) of 50 or higher.

[0057] like Figure 1 As shown, the shaft portion 10 has a first outer peripheral surface 56 and a second outer peripheral surface 57. The first outer peripheral surface 56 is disposed around the axis O. The first outer peripheral surface 56 includes the boundary surfaces between the shaft portion 10 and each of the plurality of cutting edges 6. The first outer peripheral surface 56 is annular. The first outer peripheral surface 56 surrounds the axis O.

[0058] The second outer peripheral surface 57 is disposed relative to the first outer peripheral surface 56 along the second direction 102. The second outer peripheral surface 57 is annular. The second outer peripheral surface 57 surrounds the axis O. It should be noted that the second direction 102 is the direction along the axis O toward the rear of the rotary scraper 100. Conversely, the direction along the axis O toward the front of the rotary scraper 100 is designated as the first direction 101. The first direction 101 and the second direction 102 are parallel to each other.

[0059] The shaft portion 10 has a first front end surface 51 and a second front end surface 52. The first front end surface 51 intersects, for example, the axis O. The second front end surface 52 is annular. The second front end surface 52 surrounds the axis O. The second front end surface 52 is connected to the first outer peripheral surface 56.

[0060] Multiple cutting edges 6 extend radially outward from the first outer peripheral surface 56. In this specification, radially outward refers to the direction perpendicular to the axis O and from the axis O toward the first outer peripheral surface 56. Conversely, the direction perpendicular to the axis O and from the first outer peripheral surface 56 toward the axis O is referred to as radially inward.

[0061] Multiple cutting edges 6 each have a front cutting face 5 and a rear cutting face 4. From another perspective, the rotary scraper 100 has multiple front cutting faces 5 and multiple rear cutting faces 4.

[0062] The flank face 4 is positioned relative to the cutting edge 1 along a second direction 102. The flank face 4 is connected to the rake face 5. The edges of the flank face 4 and the rake face 5 form one of the plurality of cutting edges 1. From another viewpoint, the rake face 5 is connected to the plurality of cutting edges 1. The flank face 4 is connected to the plurality of cutting edges 1. The flank face 4 is connected to the rake face 5 via the plurality of cutting edges 1.

[0063] The rotary scraper 100 has a plurality of bottoms 9. The plurality of bottoms 9 and a plurality of cutting edges 1 form the outer periphery of the rotary scraper 100. About axis O, the plurality of cutting edges 1 and the plurality of bottoms 9 are arranged alternately with each other. From another viewpoint, the plurality of bottoms 9 are respectively disposed between two adjacent cutting edges 1.

[0064] Multiple bottoms 9 are disposed radially inward relative to multiple cutting edges 1. A portion of each of the multiple bottoms 9 is formed by the edge line of the second front end face 52 and the first outer peripheral face 56.

[0065] like Figure 2 As shown, when viewing the rotary scraper 100 along the second direction 102 (hereinafter also referred to as top view), the shape of the first front end face 51 is, for example, circular. In top view, the second front end face 52 surrounds the first front end face 51. When viewed along axis O, the rake face 5 is positioned radially outward relative to the second front end face 52. When viewed along axis O, a plurality of cutting edges 1 are provided at the outermost periphery of the rotary scraper 100.

[0066] In each of the multiple cutting edges 6, the point located at the outermost periphery when viewed along axis O is designated as the outermost periphery point 89. When viewed along axis O, among the multiple cutting edges 6, the outermost periphery point 89 is located at the position with the greatest distance from axis O. For ease of explanation, in Figure 2 Only one outermost point 89 is shown in the figure, but in the rotary scraper 100, the number of outermost points 89 is equal to the number of multiple cutting edges 6.

[0067] exist Figure 3 The structure of the rotary scraper 100 as viewed along the first direction 101 is shown in the image. Figure 3 As shown, each of the plurality of cutting edges 6 has a first rear end face 61. The first rear end face 61 is connected to the flank face 4. In each of the plurality of cutting edges 6, the first rear end face 61 is connected to the rake face 5 (see reference). Figure 2 )relatively.

[0068] The shaft portion 10 has a second rear end face 62 and a third rear end face 63. The second rear end face 62 is connected to the first rear end face 61. Viewed from the first direction 101 (hereinafter also referred to as viewing from below), the second rear end face 62 is annular. The first rear end face 61 extends radially outward relative to the second rear end face 62. The third rear end face 63, for example, intersects the axis O. When viewed from below, the shape of the third rear end face 63 is, for example, circular.

[0069] like Figures 1 to 3 As shown, the rotary scraper 100 is gear-shaped. Specifically, the extension directions of each of the plurality of cutting edges 6 are substantially parallel to the axis O. From another viewpoint, as... Figure 2 as well as Figure 3 As shown, when viewed along axis O, the first rear end face 61 overlaps with the rake face 5. In other words, when viewed along the first direction 101 or the second direction 102, the first rear end face 61 overlaps with the rake face 5. When viewed along axis O, the first rear end face 61 is separated from the plurality of cutting edges 1. The rotary scraper 100, having a spur gear shape, is used for machining helical gears on the workpiece.

[0070] Figure 4 The cross-section shown is perpendicular to the plurality of cutting edges 1 and includes the axis O. Hereinafter, the cross-section perpendicular to the plurality of cutting edges 1 and including the axis O will also be referred to as the first cross-section CS1. Figure 4 As shown, the rotary scraper 100 mainly has a base portion 2 and multiple blade tip portions 3.

[0071] The base portion 2, for example, forms a portion of each of a plurality of cutting edges 6 and a shaft portion 10. The base portion 2 is formed with a first front end face 51, a second front end face 52, a first rear end face 61, a second rear end face 62, and a third rear end face 63. In the second direction 102, the base portion 2 extends, for example, from the first front end face 51 to the third rear end face 63.

[0072] The base portion 2 is formed of either cemented carbide or high-speed steel. Specifically, when the base portion 2 is formed of cemented carbide, the cemented carbide comprising tungsten carbide and cobalt. In the cemented carbide forming the base portion 2, the percentage of the weight of tungsten carbide divided by the total weight of the cemented carbide is 90.0% or more and 95.0% or less, and the percentage of the weight of cobalt divided by the total weight of the cemented carbide is 4.0% or more and 9.0% or less. When the base portion 2 is formed of high-speed steel, the base portion 2 is formed of SKH51 or SKH55.

[0073] It should be noted that SKH51 and SKH55 are high-speed steels as specified in JIS (Japanese Industrial Standards) G 4403:2015.

[0074] Multiple cutting edges 3 are connected to the base portion 2. In this specification, "connected" means that the two components are at least in contact through sintering, fastening, or other means. The two connected components can be integral or separate. The multiple cutting edges 3 form multiple cutting edges 1. Specifically, each of the multiple cutting edges 3 forms one of the multiple cutting edges 1. The multiple cutting edges 3 are arranged in a first direction 101 with respect to the base portion 2. The multiple cutting edges 1 are disposed at the front end of the rotary scraper 100.

[0075] Multiple blade tips 3 form part of each of the multiple cutting edges 6. From another perspective, the multiple cutting edges 6 are formed by the blade tips 3 and the base portion 2 respectively.

[0076] like Figure 4 As shown, in the first section CS1, the flank face 4 is inclined radially inward relative to the axis O. Specifically, in the first section CS1, the distance between the flank face 4 and the axis O in the first direction 101 becomes shorter as it moves away from the cutting edge 1.

[0077] The first front end face 51 is, for example, perpendicular to the axis O. The second front end face 52 is disposed relative to the first front end face 51 along a first direction 101. The second front end face 52 is inclined in the first direction 101 relative to the face perpendicular to the axis O. The rake face 5 is disposed relative to the second front end face 52 along the first direction 101. The rake face 5 is inclined in the first direction 101 relative to the face perpendicular to the axis O.

[0078] The first rear end face 61 is inclined in a first direction 101 relative to a plane perpendicular to axis O. The second rear end face 62 is disposed in a second direction 102 relative to the first rear end face 61. The second rear end face 62 is inclined in the first direction 101 relative to a plane perpendicular to axis O.

[0079] The third rear end face 63 is disposed along the second direction 102 relative to the second rear end face 62. The third rear end face 63 is opposite to the first front end face 51. The third rear end face 63 may also be parallel to the first front end face 51. The third rear end face 63 may be perpendicular to the axis O.

[0080] The second outer peripheral surface 57 is connected to the second rear end surface 62 and the third rear end surface 63, respectively. The second outer peripheral surface 57 is disposed along the second direction 102 relative to the first outer peripheral surface 56. The second outer peripheral surface 57 extends along the first direction 101.

[0081] like Figure 5As shown, the cutting edge portion 3 has a solder layer 23, a cemented carbide layer 22, and a cutting edge layer 21. The solder layer 23 is disposed on the base portion 2. The solder layer 23 is composed of at least one element selected from the group consisting of Ag (silver), Cu (copper), In (indium), Ti (titanium), and Zr (zirconium). The cemented carbide layer 22 is disposed on the solder layer 23. In the cemented carbide constituting the cemented carbide layer 22, the tungsten carbide content is 90.0% or more and 95.0% or less, and the cobalt content is 4.0% or more and 9.0% or less.

[0082] A cutting edge layer 21 is disposed on the cemented carbide layer 22. Alternatively, the cemented carbide layer 22 is disposed between the cutting edge layer 21 and the substrate 2. The cutting edge layer 21 is separated from the solder layer 23 by the cemented carbide layer 22. The cutting edge layer 21 forms the rake face 5. The cutting edge layer 21 is formed from any one of cubic boron nitride (cBN) sintered body, diamond, and a special cemented carbide. Details of the cBN sintered body, diamond, and special cemented carbide will be described later.

[0083] In a cross-section perpendicular to the plurality of cutting edges 1, each of the plurality of cutting edges 1 is, for example, arc-shaped. In a cross-section perpendicular to the plurality of cutting edges 1, the radius of curvature A of the plurality of cutting edges 1 is 10 μm or more and 40 μm or less. The radius of curvature A may also be 12 μm or more, or 15 μm or more. The radius of curvature A may also be 38 μm or less, or 35 μm or less.

[0084] like Figure 5 As shown, the plurality of cutting edges 6 each have a first flank face 7 and a second flank face 8. The first flank face 7 and the second flank face 8 form the flank face 4. The first flank face 7 is formed by a cutting tip 3. Specifically, the first flank face 7 is formed by a cutting tip layer 21, a carbide layer 22, and a brazing filler metal layer 23. The first flank face 7 is connected to the plurality of cutting edges 1.

[0085] The second rear cutting surface 8 is formed from the base portion 2. The second rear cutting surface 8 is disposed along the second direction 102 relative to the first rear cutting surface 7. The second rear cutting surface 8 is connected to the first rear cutting surface 7, for example. The second rear cutting surface 8 and the first rear end face 61 (see reference) Figure 4 The first rear blade face 7 and the second rear blade face 8 are connected, for example, smoothly.

[0086] Multiple cutting edges 6 each have a connecting surface 66. The connecting surface 66 connects the rake face 5 and the second front end face 52. The connecting surface 66 is smoothly connected to the rake face 5 and the second front end face 52 respectively.

[0087] The base portion 2 has a seat surface 20 and a sidewall surface 55. The seat surface 20 is in contact with the tip portion 3. Specifically, the seat surface 20 is in contact with the solder layer 23. The solder layer 23 is disposed on the seat surface 20. The seat surface 20 is, for example, planar. The seat surface 20 is, for example, perpendicular to the axis O. In the first cross-section CS1, the distance between the rake face 5 and the seat surface 20 in the first direction 101 decreases as it moves away from the cutting edge 1.

[0088] The sidewall surface 55 is connected to the base surface 20 and the connecting surface 66, respectively. The sidewall surface 55 is perpendicular to the base surface 20, for example. The sidewall surface 55 is in contact with the tool tip 3. Specifically, the sidewall surface 55 is in contact with the tool tip layer 21, the cemented carbide layer 22, and the brazing filler metal layer 23, respectively.

[0089] The cutting tip 3 has a first bottom surface 30. The first bottom surface 30 is in contact with the base portion 2. Specifically, the first bottom surface 30 is in contact with the seat surface 20 of the base portion 2. The first bottom surface 30 is, for example, covered by the base portion 2. The first bottom surface 30 is formed by a solder layer 23. The first bottom surface 30 is, for example, planar. The first bottom surface 30 is, for example, perpendicular to the axis O.

[0090] The maximum thickness (first thickness H1) of the cutting edge layer 21 in the first direction 101 is, for example, 0.3 mm or more and 3 mm or less. The first thickness H1 may also be 0.5 mm or more, or 1 mm or more. The first thickness H1 may also be 2.5 mm or less, or 2 mm or less. The first thickness H1 is the longest distance in the first direction 101 between the interface between the cutting edge layer 21 and the carbide layer 22 and between the plurality of cutting edges 1.

[0091] The maximum thickness (second thickness H2) of the carbide layer 22 in the first direction 101 is, for example, more than 0.5 mm and less than 5 mm. The second thickness H2 is the longest distance in the first direction 101 between the interface between the tip layer 21 and the carbide layer 22 and the interface between the carbide layer 22 and the solder layer 23.

[0092] The maximum thickness (third thickness H3) of the solder layer 23 in the first direction 101 is, for example, more than 0.01 mm and less than 0.05 mm. The third thickness H3 is the longest distance in the first direction 101 between the interface between the cemented carbide layer 22 and the solder layer 23 and the first bottom surface 30.

[0093] like Figure 5 As shown, the first section CS1 can also pass through the outermost peripheral point 89. From another perspective, Figure 5 The cross-section shown includes axis O (see reference). Figure 4 And through the cross section at the outermost circumference point 89. Figure 5 The line 99 shown is a line perpendicular to the axis O. In the cross section containing the axis O and passing through the outermost circumference point 89, the angle between line 99 and the rake face 5 is the rake angle φ1.

[0094] In each of the multiple cutting edges, the rake angle φ1 is, for example, 0° or more and 40° or less. The rake angle φ1 can also be, for example, 5° or more and 15° or less. The rake angle φ1 can also be, for example, 3° or more, or 8° or more. The rake angle φ1 can also be, for example, 30° or less, 18° or less, or 13° or less.

[0095] like Figure 6 as well as Figure 7 As shown, the multiple cutting edges 1 are formed by a first cutting edge portion 11, a second cutting edge portion 12, and a corner cutting edge portion 13, respectively.

[0096] The second cutting edge 12 is disposed relative to the first cutting edge 11 along the rotational direction R. The second cutting edge 12 is opposite to the first cutting edge 11. A corner cutting edge 13 connects the first cutting edge 11 and the second cutting edge 12. The corner cutting edge 13 is disposed radially outward relative to both the first cutting edge 11 and the second cutting edge 12. In each of the plurality of cutting edges 1, the corner cutting edge 13 is disposed between the first cutting edge 11 and the second cutting edge 12. When viewed from above, the corner cutting edge 13 is, for example, arc-shaped.

[0097] like Figure 6 As shown, the first flank face 7 has a first portion 71, a first corner face 73, and a second portion 72. The first portion 71 forms a first cutting edge 11 with the edge of the rake face 5. The first corner face 73 is connected to the first portion 71. The first corner face 73 forms a corner cutting edge 13 with the edge of the rake face 5. The second portion 72 is connected to the first corner face 73. The second portion 72 forms a second cutting edge 12 with the edge of the rake face 5.

[0098] The second rear blade face 8 has a third portion 81, a second corner face 83, and a fourth portion 82. The third portion 81, together with the first portion 71 and the first rear end face 61 (see reference). Figure 3 The second corner face 83 is connected to the first corner face 73, the first rear end face 61, and the third part 81, respectively. The fourth part 82 is connected to the second part 72, the first rear end face 61, and the second corner face 83, respectively. The connecting surface 66 is connected to the first outer peripheral surface 56. The edge line of the connecting surface 66 and the first outer peripheral surface 56 forms part of the bottom 9. Figure 6 As shown, the lines on the back face 4 at the front ends of the multiple cutting edges 6 are designated as the ridge lines 88 of the back face 4.

[0099] Figure 8 It means from Figure 2The diagram shows a side view of the structure of the rotary scraper 100 when viewed in the direction of arrow D. Arrow D is perpendicular to axis O and points from the outermost circumference point 89 toward axis O.

[0100] like Figure 8 As shown, when viewed perpendicular to axis O and from the outermost point 89 toward axis O, the edge line 88 is located midway between the boundary line (first boundary line 26) of the first part 71 and the first corner face 73, and the boundary line (second boundary line 27) of the second part 72 and the first corner face 73. From another viewpoint, when viewed perpendicular to axis O and from the outermost point 89 toward axis O, the distance between the edge line 88 and the first boundary line 26 and the distance between the edge line 88 and the second boundary line 27 are the same in the direction perpendicular to the edge line 88.

[0101] Similarly, when viewed perpendicular to axis O and from the outermost point 89 toward axis O, edge 88 is located midway between the boundary line of the third part 81 and the second corner face 83 (third boundary line 28) and the boundary line of the fourth part 82 and the second corner face 83 (fourth boundary line 29). From another viewpoint, when viewed perpendicular to axis O and from the outermost point 89 toward axis O, the distance between edge 88 and the third boundary line 28 and the distance between edge 88 and the fourth boundary line 29 are the same in the direction perpendicular to edge 88.

[0102] The ridge line 88 may, for example, be parallel to the axis O. In other words, when viewed perpendicularly to the axis O and from the outermost point 89 toward the axis O, the angle between the ridge line 88 and the axis O may, for example, be 0°. The first corner face 73 extends along the ridge line 88. The second corner face 83 extends along the ridge line 88.

[0103] (cBN sintered body) Next, the details of the cBN sintered body will be explained. The cBN sintered body contains cBN particles. The percentage of the volume of cBN particles divided by the total volume of the cBN sintered body (cBN particle content) is, for example, 50% or more and 100% or less. The cBN particle content can be, for example, 70% or more, 80% or more, or 90% or more. The cBN particle content can be, for example, 99% or less, or 97% or less.

[0104] The average particle size of cBN particles (D) 50For example, the particle size is 0.01 μm or larger and 3 μm or smaller. The average particle size of cBN particles can be 0.03 μm or larger and 0.08 μm or larger. The average particle size of cBN particles can be 2 μm or smaller, 1.5 μm or smaller, or 0.7 μm or smaller.

[0105] cBN sintered bodies may also contain binder materials. The binder materials bind the cBN particles together. When a cBN sintered body contains binder materials, the cBN particle content in the cBN sintered body is less than 100%. A cBN sintered body can consist of cBN particles and binder materials, or it can consist of cBN particles, binder materials, and unavoidable impurities.

[0106] The bonding material may include, for example, at least one element selected from the group consisting of titanium (Ti), cobalt (Co), aluminum (Al), and zirconium (Zr). Specifically, the bonding material may include, for example, at least one of titanium nitride (TiN), cobalt, titanium carbide (TiC), titanium carbonitride (TiCN), aluminum oxide (Al2O3), zirconium oxide (ZrO2), and aluminum nitride (AlN).

[0107] (cBN particle content) In the aforementioned cBN sintered body, the cBN particle content can be confirmed by performing microstructural observation and elemental analysis using an energy-dispersive X-ray spectroscopy (EDX) device attached to a scanning electron microscope (SEM). The SEM can be the "JSM-7800F" (trade name) manufactured by Nippon Electronics Corporation. The EDX can be the OctaneElect EDS system. Hereinafter, the EDX attached to the SEM will also be referred to as SEM-EDX. The specific measurement method is described below.

[0108] (A1) First, the cBN sintered body is cut at any point to prepare a sample containing a cross-section of the cBN sintered body. The cross-section can be prepared using a focused ion beam apparatus, a cross-section polishing machine, etc. Next, the cross-section is observed using a SEM at 1000x magnification to obtain a reflected electron image. In the reflected electron image, the areas containing cBN particles are black areas, and the areas containing the bonding material are gray and / or white areas.

[0109] (B1) Next, the above-mentioned electron reflection image was binarized using image analysis software (WinROOF of Mitani Corporation). In the binarized image, the regions containing cBN particles (black regions in the electron reflection image) were designated as dark fields, and the regions containing binding material (gray and / or white regions in the electron reflection image) were designated as bright fields. A measurement area (70 μm × 100 μm) was set in the binarized image. The area ratio of pixels originating from the dark field (pixels originating from cBN particles and pixels originating from black regions in the electron reflection image) in the total area of ​​the measurement field of view was calculated. By treating the calculated area ratio as a volume ratio, the cBN particle content could be determined.

[0110] It should be noted that the following has been confirmed: as long as the measurement is performed in the same blade tip layer 21 using the above method, the measurement results will not deviate even if the measurement location is arbitrarily changed.

[0111] (Based on the material) The statement that "the bonding material contains at least one element selected from the group consisting of Ti, Co, Al, and Zr" can be determined by XRD (X-ray diffraction). That is, "the bonding material contains at least one element selected from the group consisting of Ti, Co, Al, and Zr" means that at least one element selected from the group consisting of Ti, Co, Al, and Zr is present in the bonding material to a degree that can be detected by XRD.

[0112] (Average particle size of cBN particles) The average particle size of cBN particles was calculated as follows. First, following the method described above for calculating the cBN particle content, a sample containing a cross-section of the cBN sintered body was prepared, and a reflective electron image was obtained. Next, the equivalent circle diameter of each dark field (corresponding to cBN) in the reflective electron image was calculated using image analysis software (Mitani Corporation's "WinROOF (ver. 7.4.5)"). Preferably, the equivalent circle diameter of more than 100 cBN particles was calculated by observing more than five fields of view.

[0113] Next, the cumulative distribution is calculated by arranging the equivalent diameters of each circle in ascending order from minimum to maximum. The particle size representing 50% of the cumulative area in the cumulative distribution is the average particle size. It should be noted that the equivalent circle diameter refers to the diameter of a circle with an area equal to the area of ​​the measured cBN particle.

[0114] (Diamond) Next, a detailed explanation of diamond will be provided. Diamond can be either polycrystalline diamond or single-crystal diamond (SCD: Single-Crystal Diamond).

[0115] Polycrystalline diamond comprises multiple diamond particles. It may also contain a binding phase (binder). This binding phase may contain, for example, at least one element selected from iron (Fe), cobalt (Co), and nickel (Ni), or any solid solution thereof. Specifically, the binding phase may be formed from Co, Co-Fe, Ni-Co, etc. Hereinafter, polycrystalline diamond containing a binding phase is also referred to as polycrystalline sintered diamond or PCD (Poly-Crystalline Diamond).

[0116] Polycrystalline diamond may not contain a binding phase. Hereinafter, polycrystalline diamond without a binding phase is also called binderless polycrystalline diamond or BLPCD. BLPCD is polycrystalline diamond in which multiple diamond particles are bonded together without a binder. In this specification, polycrystalline diamond includes PCD and BLPCD.

[0117] BLPCDs are fabricated, for example, by using a high-temperature and high-pressure (HTHP) synthesis method to convert graphite into diamond particles while sintering the diamond particles without using a binding phase. More specifically, for example, BLPCDs are fabricated by directly converting graphite into diamond particles under high temperature and high pressure conditions of 1800°C to 2500°C and 15 GPa to 25 GPa while simultaneously sintering the diamond particles.

[0118] PCD is fabricated, for example, by sintering a mixture of raw material powder containing the bonding phase and diamond particles produced by methods such as HTHP. SCD is fabricated using methods such as HTHP and chemical vapor deposition (CVD).

[0119] When the diamond is polycrystalline, the percentage of the volume of each diamond particle divided by the total volume of the diamond (diamond particle content) is, for example, 80% or more and 100% or less. The diamond particle content can be, for example, 85% or more, 92% or more, or 97% or more. The diamond particle content can be, for example, 99% or less and 98% or less. The diamond particle content can be determined, for example, using secondary ion mass spectrometry (SIMS).

[0120] In a BLPCD, the percentage obtained by dividing the volume of carbon by the total volume of the BLPCD excluding impurity elements is 100%. The percentage obtained by dividing the volume of impurity elements by the total mass of the BLPCD (the impurity element content) is, for example, 5% or less. The impurity element content in a BLPCD can also be 0%.

[0121] When the diamond is polycrystalline diamond, the average particle size (D) of the diamond particles is... 50 For example, the diameter is 0.01 μm or larger and less than 100 μm. The average particle size of the diamond particles can also be 0.05 μm or larger, or 0.1 μm or larger. The average particle size of the diamond particles can also be 70 μm or smaller, or 40 μm or smaller, or 10 μm or smaller.

[0122] The average particle size of diamond particles can be determined using a SEM and image analysis software. For example, the "JSM-7800F" (trade name) manufactured by Nippon Electronics Co., Ltd. can be used as an SEM. For example, WinROOF manufactured by Mitani Corporation can be used as image analysis software.

[0123] Specifically, firstly, a polycrystalline diamond sample was prepared by cutting the blade tip layer 21. The surface of the sample was then mirror-polished. Next, the reflected electron image of the mirror-polished surface of the sample was observed using SEM at a magnification of 5000x or higher but less than 20000x. Multiple diamond particles were then identified in the reflected electron image.

[0124] The equivalent circle diameter of each diamond particle, as determined by image analysis software, is calculated. For example, the equivalent circle diameter of more than 100 diamond particles can be calculated by observing more than five fields of view. Then, the cumulative distribution is obtained by arranging all the calculated equivalent circle diameters in ascending order from minimum to maximum. The particle diameter representing 50% of the cumulative area in the cumulative distribution is designated as D. 50 It should be noted that the equivalent circle diameter refers to the diameter of a circle with an area equal to the area of ​​the diamond particle being measured.

[0125] (Special cemented carbide) Next, the details of the special cemented carbide will be explained. The special cemented carbide contains tungsten carbide particles and a bonding phase. In the special cemented carbide, the percentage of the bonding phase volume divided by the total volume of the special cemented carbide (bonding phase content) is 0.7% or more and 28% or less. For example, the bonding phase content can be 2% or more, 10% or more, 15% or more, or 20% or more. For example, the bonding phase content can be 27.5% or less and 25% or less.

[0126] Special cemented carbides can be composed of tungsten carbide particles and a bonding phase. In this case, the special cemented carbide may also contain unavoidable impurities without impairing the effects of this disclosure.

[0127] The bonding phase includes cobalt. The bonding phase also includes at least one element (the first element) selected from the group consisting of silicon, phosphorus, germanium, tin, rhenium, ruthenium, osmium, iridium, and platinum. It should be noted that the cemented carbide forming the matrix 2 does not contain the first element. In this specification, to distinguish it from special cemented carbides, cemented carbides that do not contain the first element are referred to as "cemented carbides".

[0128] In the bound phase, the percentage of cobalt content (the value obtained by dividing the mass of cobalt by the total mass of the bound phase) is 50% or more. The cobalt content can be 50% or more but less than 100%, 60% or more but less than 98%, or 70% or more but less than 95%.

[0129] In the bound phase, the percentage of the value obtained by dividing the mass of the first element by the total mass of the bound phase (the content of the first element) is, for example, more than 1% and less than 6%.

[0130] The special cemented carbide may also not contain intermetallic compounds composed of two or more elements selected from the group consisting of the first element, cobalt, and tungsten, or compounds composed of at least one element selected from the group consisting of the first element, cobalt, and tungsten, and at least one element selected from the group consisting of carbon, nitrogen, and oxygen. Here, the aforementioned compounds do not contain tungsten carbide. Therefore, it is possible to suppress the reduction in both the hardness and strength of the special cemented carbide.

[0131] Examples of the aforementioned intermetallic compounds include Co2Si, Co3Si, and CoSi. Examples of the aforementioned compounds include Co3W3C and Co6W6C. The fact that the special cemented carbide does not contain any of the aforementioned intermetallic compounds or any of the aforementioned compounds can be confirmed by observing the microstructure of the special cemented carbide cross-section and performing EDX analysis.

[0132] Special cemented carbides, in addition to containing tungsten carbide particles and a bonding phase, may also contain other phases. These other phases may include, for example, carbides, nitrides, or carbonitrides containing at least one element selected from the group consisting of titanium (Ti), tantalum (Ta), niobium (Nb), zirconium (Zr), hafnium (Hf), and molybdenum (Mo). Other phases may include metals or alloys containing at least one element selected from the group consisting of nickel, chromium, and molybdenum.

[0133] Special cemented carbides may consist of tungsten carbide particles, bonding phases, and other phases. In this case, the special cemented carbide may contain impurities without impairing the effects of this disclosure.

[0134] In special cemented carbides, the percentage of the volume of other phases divided by the total volume of the special cemented carbides (the content of other phases) is permissible without impairing the effects of this disclosure. The content of other phases may, for example, be greater than 0% and less than 11%, greater than 0% and less than 7%, or greater than 0% and less than 4%.

[0135] Special cemented carbides may also contain impurities. Impurities may include, for example, iron (Fe), calcium (Ca), silicon (Si), and sulfur (S). In special cemented carbides, the percentage of the mass of the impurity divided by the total mass of the special cemented carbides (the impurity content) is permissible without impairing the effects of this disclosure. The impurity content may, for example, be 0% or more and less than 0.1%. The impurity content can be determined using inductively coupled plasma optical emission spectrometry (ICP). For ICP analysis, the "ICPS-8100" (trademark) manufactured by Shimadzu Corporation can be used.

[0136] The content of the bonding phase in special cemented carbides can be determined using the following methods.

[0137] (A2) Cut out any position of the special hard alloy to expose the cross-section. Use a cross-section polishing machine (manufactured by Nippon Electronics Co., Ltd.) to mirror finish the cross-section.

[0138] (B2) The cross-section after mirror finishing was analyzed using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX). This determined the elements contained in the special cemented carbide. The Gemini 450 (trademark) manufactured by Carl Zeiss could be used for SEM-EDX.

[0139] (C2) A reflected electron image was obtained by photographing the cross-section after mirror finishing using a scanning electron microscope (SEM). The imaging area for the reflected electron image was set in the center of the cross-section of the special cemented carbide. Specifically, the imaging area was set in a location near the surface of the special cemented carbide, excluding parts whose properties differ significantly from the main body. The magnification was set to 5000x. In other words, the imaging area was set such that only the main body of the special cemented carbide constituted the imaging area. The measurement conditions were set as follows: accelerating voltage 3kV, current 2nA, and working distance (WD) 5mm.

[0140] (D2) For the imaging area defined in (C2) above, analysis is performed using an energy-dispersive X-ray analyzer attached to the SEM. The distribution of the elements determined in (B2) above within the imaging area is determined. Thus, an elemental mapping image is obtained.

[0141] (E2) The reflected electron image obtained in (C2) above is read into the computer. Image analysis software (OpenCV, SciPy) is used to binarize the reflected electron image. In the binarized image, tungsten carbide particles are represented in white, and the bound phase is represented in gray or black. It should be noted that the binarization threshold varies depending on the contrast, and therefore is set for each image.

[0142] (F2) Overlay the elemental mapping image obtained in (D2) above with the binarized image obtained in (E2) above. Thus, in the binarized image, the respective regions where tungsten carbide particles and the binding phase exist are determined. Specifically, regions represented in white in the binarized image and containing tungsten (W) and carbon (C) in the elemental mapping image are designated as regions where tungsten carbide particles exist. Regions represented in gray or black in the binarized image and containing cobalt (Co) in the elemental mapping image are designated as regions where the binding phase exists.

[0143] (G2) In the image after binarization, a measurement field of view is set. The measurement field of view is set as a rectangle of 24.9 μm × 18.8 μm. Using the image analysis software described above, the area percentage of tungsten carbide particles and the area percentage of the binding phase are calculated. Specifically, the area percentage of tungsten carbide particles is obtained by dividing the area of ​​the tungsten carbide particles in the measurement field of view by the entire measurement field of view. The area percentage of the binding phase is obtained by dividing the area of ​​the binding phase in the measurement field of view by the entire measurement field of view.

[0144] (H2) The determination in (G2) above was performed in five distinct measurement fields. In this disclosure, the average area percentage of tungsten carbide particles in the five measurement fields is taken as the tungsten carbide particle content of the special cemented carbide. The average area percentage of the bound phase in the five measurement fields is taken as the bound phase content of the special cemented carbide.

[0145] In the case where the special cemented carbide contains other phases, the content of the other phases in the special cemented carbide is obtained by subtracting the tungsten carbide particle content and the bound phase content (volume %) determined according to the above steps from 100%.

[0146] It has been confirmed that as long as the measurement is performed on the same sample, even if the cut-out part of the special cemented carbide profile, the shooting area described in (C2) above, and the measurement field of view described in (G2) above are arbitrarily set, and the tungsten carbide particle content and the bound phase content are measured multiple times according to the above steps, the measurement results are almost without deviation.

[0147] The method for determining the cobalt content of the bound phase is as follows. Using the same method as (A2) to (F2) for determining the content of tungsten carbide particles and the bound phase in the aforementioned special hard alloy, the region where the bound phase exists is determined on the binarized image. In the binarized image, a rectangular field of view of 24.9 μm × 18.8 μm is set. The region where the bound phase exists in the field of view is analyzed using SEM-EDX, and the cobalt content of the bound phase is determined. The above determination is performed in five distinct field of view. In this disclosure, the average cobalt content of the bound phase in the five field of view is taken as the cobalt content of the bound phase.

[0148] It was confirmed that as long as the measurement is performed on the same sample, even if the cut-out part of the special hard alloy profile is arbitrarily set, the shooting area described in (C2) above is used, and the cobalt content of the bound phase is measured multiple times according to the above steps, the measurement results are almost without deviation.

[0149] The presence of the first element in the bonding phase is confirmed through the following steps. Using the same method (A2) to (F2) as the methods described above for determining the content of tungsten carbide particles and the content of the bonding phase in the special cemented carbide, the region where the bonding phase exists is determined on the binarized image. For the region where the bonding phase exists, SEM-EDX analysis is performed to confirm that the bonding phase contains the first element if the first element is present in the region where the bonding phase exists.

[0150] In special hard alloys, the bonding phase, in addition to containing cobalt and the first element, may also contain at least one second element selected from the group consisting of iron (Fe), nickel (Ni), and chromium (Cr). The bonding phase can be composed of cobalt, the first element, and the second element. Alternatively, the bonding phase can consist of cobalt, the first element, the second element, and unavoidable impurities. Unavoidable impurities include, for example, iron (Fe), nickel (Ni), and sulfur (S).

[0151] <Manufacturing Methods of Special Hard Alloys> The manufacturing method of special cemented carbide includes a raw material powder preparation process, a mixing process, a forming process, a sintering process, and a first cooling process. The manufacturing method of special cemented carbide may also include a HIP (Hot Isostatic Pressing) process and a second cooling process. The following describes each process.

[0152] <Preparation Process> The preparation process involves preparing the raw material powders that constitute the materials of the special hard alloy. As raw material powders, tungsten carbide powder (hereinafter also referred to as "WC powder"), cobalt (Co) powder, first element powder, and alloy powders of the first element and cobalt are prepared. As first element powders, at least one of silicon (Si) powder, phosphorus (P) powder, germanium (Ge) powder, tin (Sn) powder, rhenium (Re) powder, ruthenium (Ru) powder, osmium (Os) powder, iridium (Ir) powder, and platinum (Pt) powder may also be prepared. Titanium carbonitride (TiCN), nickel-chromium alloy (NiCr), or titanium carbonitride-niobium (TiNbCN) may also be prepared as raw material powders.

[0153] Commercially available raw material powders can be used. There are no particular limitations on the average particle size of the raw material powder; for example, it can be set to be greater than 0.5 μm and less than 5 μm. The average particle size of the raw material powder is the average particle size determined by the FSSS (Fisher Sub-Sieve Sizer) method. This average particle size can be determined using the "Sub-Sieve Sizer Model 95" (trademark) manufactured by Fisher Scientific.

[0154] <Mixed Processes> The mixing process involves combining the raw material powders prepared in the preparation process in a predetermined ratio. Through this process, a mixed powder is obtained. The mixing ratio of the raw material powders is adjusted appropriately according to the composition of the special cemented carbide being manufactured.

[0155] The mixing of the various raw material powders can be performed using conventionally known mixing methods such as grinding mills, ball mills, and bead mills. Conventionally known mixing conditions can also be used. The mixing time can, for example, be set to be more than 2 hours and less than 20 hours.

[0156] After the mixing process, the mixed powder can be granulated as needed. By granulating the mixed powder, it can be easily filled into the die head or mold in the forming process described later. Known granulation methods can be used for granulation. For example, commercially available granulators such as spray dryers can be used.

[0157] <Forming Process> The forming process is a process of obtaining a formed body by forming the mixed powder obtained in the mixing process into the shape of the cutting edge layer 21. The forming method and forming conditions in the forming process may be general methods and conditions, and there are no particular limitations.

[0158] <Sintering process> The sintering process is a process of sintering the formed body obtained in the forming process. Specifically, the formed body is heated to 1400 °C at a heating rate of 50 °C / minute and held at 1400 °C for 60 minutes.

[0159] <First cooling process> In the first cooling process, the sintered formed body is cooled to 800 °C. The cooling rate is 80 °C / minute.

[0160] <HIP process and second cooling process> The HIP process and the second cooling process may also be performed after the first cooling process. Thereby, the material strength of the cemented carbide can be improved. The HIP process is a process of performing HIP treatment on the cemented carbide after the first cooling process. In the HIP process, the cemented carbide is held at 200 MPa and 1290 °C for 60 minutes.

[0161] The second cooling process is a process of cooling the cemented carbide after the HIP process. Specifically, the cemented carbide is cooled to 800 °C. The cooling rate is 80 °C / minute. After that, the cemented carbide is slowly cooled. The cooling rate during slow cooling may be general conditions and there are no particular limitations.

[0162] In the manufacturing method of the cemented carbide, the heating rate in the sintering process is 50 °C / minute, which is greater than the general heating rate. In addition, the cooling rates in the first cooling process and the second cooling process are 80 °C / minute, which are greater than the general cooling rates. Under these conditions, a cemented carbide can be manufactured in which the binding phase contains 50% by mass or more of cobalt and contains at least one first element selected from the group consisting of silicon, phosphorus, germanium, tin, rhenium, ruthenium, osmium, iridium, and platinum. The cemented carbide of the present disclosure that can be realized by adopting such a heating rate in the sintering process was discovered as a result of in-depth research by the inventors of the present invention.

[0163] Next, the operation and effect of the turning tool 100 according to the first embodiment will be described.

[0164] As Figure 9 and Figure 10As shown, for example, the rotary scraper 100 is arranged such that its axis O is inclined relative to the rotation axis C of the machined surface 91 of the workpiece 90 by an angle θ. The machined surface 91 is, for example, the inner circumferential surface of the workpiece 90.

[0165] The rotary scraper 100 rotates about axis O in the direction of rotation R. The workpiece 90 rotates about axis of rotation C along arrow B. The rotary scraper 100 moves along arrow F. Arrow F is directed along axis of rotation C from the rotary scraper 100 toward the workpiece 90. Multiple cutting edges 1 contact the machined surface 91. Thus, the multiple cutting edges 1 cut the workpiece 90. As a result, the workpiece 90 is machined, for example, into an internal gear shape.

[0166] In spun cutting, the cutting edge of the spun cutting tool can sometimes wear significantly. For example, when machining a workpiece made of a high-hardness material (hard spun cutting), the cutting edge can sometimes wear significantly. For example, when machining a workpiece made of hardened steel, the cutting edge can sometimes wear significantly due to the high hardness of the hardened steel.

[0167] The rotary scraper 100 according to the first embodiment has a base portion 2 and a cutting tip portion 3. The cutting tip portion 3 is connected to the base portion 2. The cutting tip portion 3 has a cutting tip layer 21. The cutting tip layer 21 forms a plurality of cutting edges 1. The base portion 2 is formed of either cemented carbide or high-speed steel. The cutting tip layer 21 is formed of either cBN sintered body, diamond, or a special cemented carbide.

[0168] For example, cBN sintered bodies, diamond, and special cemented carbides each have higher wear resistance than cemented carbides and high-speed steel. Therefore, the rotary scraper 100 according to the first embodiment can improve the wear resistance of the cutting edge 1. As a result, wear on the cutting edge 1 can be suppressed.

[0169] According to the first embodiment, the rotary scraper 100 can effectively suppress the wear of the cutting edge 1 even when the workpiece is formed from hardened steel with high hardness.

[0170] When machining a workpiece made of a high-hardness material, the force applied to the rotary scraper 100 becomes excessive. Specifically, for example, the force applied to the cutting edge 1 becomes excessive. In this case, damage sometimes occurs in the portion of the rotary scraper 100 near the cutting edge 1.

[0171] For example, cBN sintered bodies, diamond, and special cemented carbides each have a higher hardness than cemented carbides and high-speed steel. Therefore, according to the rotary scraper 100 of the first embodiment, the hardness of the portion of the rotary scraper 100 near the cutting edge 1 can be increased. As a result, damage to the portion of the rotary scraper 100 near the cutting edge 1 can be prevented.

[0172] The toughness of cemented carbide and high-speed steel is higher than that of cBN sintered body, diamond, and special cemented carbide. Therefore, in the rotary scraper 100 according to the first embodiment, the base portion 2 is formed of either cemented carbide or high-speed steel, thereby improving the toughness of the base portion 2. As a result, the breakage of the rotary scraper 100 can be suppressed.

[0173] The cutting tip 3 has a cemented carbide layer 22. Therefore, compared with the case where the cutting tip 3 is formed only by cBN sintered body and diamond, the breakage of the cutting tip 3 can be suppressed.

[0174] The thermal conductivity of cBN sintered body, diamond, and special cemented carbide is higher than that of cemented carbide. Therefore, by making the tip layer 21 formed of any one of cBN sintered body, diamond, and special cemented carbide, thermal wear caused by temperature rise at the tip can be suppressed.

[0175] According to the rotary scraper 100 of the first embodiment, the maximum thickness (first thickness H1) of the blade tip layer 21 in the first direction 101 is 0.3 mm or more and 3 mm or less. By making the first thickness H1 0.3 mm or more, wear on the rear blade surface 4 can be effectively suppressed. By making the first thickness H1 3 mm or less, breakage of the blade tip 3 can be suppressed.

[0176] According to the rotary scraper 100 of the first embodiment, in a cross-section perpendicular to the plurality of cutting edges 1, the radius of curvature A of the plurality of cutting edges 1 is 10 μm or more and 40 μm or less. By making the radius of curvature A 10 μm or more, the pressure applied to the plurality of cutting edges 1 can be reduced. As a result, defects in the portion of the rotary scraper 100 near the plurality of cutting edges 1 can be suppressed. By making the radius of curvature A 40 μm or less, the excessive reduction of the sharpness of the plurality of cutting edges 1 can be suppressed.

[0177] According to the rotary scraper 100 of the first embodiment, in the special cemented carbide, the bonding phase further includes at least one first element selected from the group consisting of silicon, phosphorus, germanium, tin, rhenium, ruthenium, osmium, iridium, and platinum. Therefore, in the special cemented carbide, the hardness and strength of the bonding phase can be improved, and the interfacial strength between tungsten carbide particles can be increased. Consequently, tool life can be extended.

[0178] The hardness of cBN particles is greater than that of the bonding material. Therefore, as the cBN particle content in the cBN sintered body increases, the hardness of the cBN sintered body can be improved. According to the rotary scraper 100 of the first embodiment, the percentage obtained by dividing the volume of cBN particles by the total volume of the cBN sintered body is 50% or more. Therefore, the hardness of the cBN sintered body can be sufficiently improved. As a result, defects at the blade tip 3 can be effectively suppressed.

[0179] According to the rotary scraper 100 of the first embodiment, the average particle size of the cBN particles in the cBN sintered body is 3 μm or less. Therefore, the gaps between the cBN particles can be reduced. Consequently, the thickness of the bonding material, which has a lower hardness than the cBN particles, can be reduced in the cBN sintered body. Therefore, defects at the blade tip 3 can be effectively suppressed.

[0180] According to the rotary scraper 100 of the first embodiment, the bonding material in the cBN sintered body includes at least one selected from the group consisting of Ti, Co, Al, and Zr. This improves the wear resistance of the cBN sintered body. As a result, wear on the blade tip 3 can be effectively suppressed.

[0181] When the rake angle φ1 is too large, the portion of the rotary scraper 100 near the cutting edge 1 becomes excessively sharp. Consequently, the strength of this portion of the rotary scraper 100 near the cutting edge 1 is excessively reduced. According to the rotary scraper 100 of the first embodiment, the rake angle φ1 is 40° or less. Therefore, it is possible to prevent the excessive reduction in strength of the portion of the rotary scraper 100 near the cutting edge 1.

[0182] According to the rotary scraper 100 of the first embodiment, the rake angle φ1 can be 5° or more and 15° or less. This effectively improves the sharpness of the cutting edge 1. As a result, wear on the portion of the rotary scraper 100 near the cutting edge 1 can be effectively suppressed.

[0183] According to the rotary scraper 100 of the first embodiment, the tip layer 21 can also be formed of diamond. The diamond can be polycrystalline diamond. If the diamond particle content in the polycrystalline diamond is too low, the strength of the tip layer 21 will be excessively reduced. According to the rotary scraper 100 of the first embodiment, the diamond particle content in the diamond is 80% or more. Therefore, the excessive reduction in the strength of the tip layer 21 can be suppressed.

[0184] When the average particle size of the diamond particles is too large, poor sintering of the diamond particles sometimes occurs during diamond production. In this case, the strength of the tip layer 21 decreases. According to the rotary scraper 100 of the first embodiment, the average particle size of the diamond particles is 100 μm or less. Therefore, poor sintering of the diamond particles can be suppressed. As a result, the decrease in the strength of the tip layer 21 can be suppressed.

[0185] (Second Implementation) Next, the structure of the rotary scraper 100 according to the second embodiment will be described. The rotary scraper 100 according to the second embodiment differs from the rotary scraper 100 according to the first embodiment mainly in that a portion of the first bottom surface 30 of the blade tip 3 is provided on the outer side of the base portion 2; otherwise, it is substantially the same as the rotary scraper 100 according to the first embodiment. Hereinafter, the description will focus on the differences from the rotary scraper 100 according to the first embodiment.

[0186] Figure 11 express Figure 5 The cross-section shown. (As shown) Figure 11 As shown, a portion of the first bottom surface 30 of the blade tip 3 may also be disposed on the outer side of the base portion. The first bottom surface 30 of the blade tip 3 has a first bottom surface 36 and a second bottom surface 37.

[0187] The first bottom surface portion 36 is in contact with the base portion 2. From another viewpoint, the first bottom surface portion 36 is covered by the base portion 2. In the tip portion 3, the second bottom surface portion 37 is connected to both the first rear cutting surface portion 7 and the first bottom surface portion 36. The second bottom surface portion 37 is located on the outer side relative to the base portion 2. The first rear cutting surface portion 7 and the second rear cutting surface portion 8 are separate from each other.

[0188] Figure 12 express Figure 3 Region XII. For ease of explanation, in Figure 12 The boundary lines between the tool tip layer 21 and the cemented carbide layer 22, as well as the boundary lines between the cemented carbide layer 22 and the solder layer 23, are not shown in the diagram. Figure 12 As shown, the second bottom surface 37 is disposed between the first rear blade surface 7 and the second rear blade surface 8.

[0189] The edges of the first rear cutting surface 7 and the second bottom surface 37 form a first edge portion 31, a corner edge portion 33, and a second edge portion 32. The first edge portion 31 is formed by the edges of the first portion 71 and the second bottom surface 37. The corner edge portion 33 is formed by the edges of the first corner surface 73 and the second bottom surface 37. The corner edge portion 33 is connected to the first edge portion 31. The corner edge portion 33 is disposed radially outward relative to the first edge portion 31.

[0190] The second ridge portion 32 is formed by the ridge lines of the second portion 72 and the second bottom portion 37. The second ridge portion 32 is connected to the corner ridge portion 33. The corner ridge portion 33 is disposed between the first ridge portion 31 and the second ridge portion 32. The second ridge portion 32 is disposed relative to the first ridge portion 31 along the rotation direction R. The second ridge portion 32 is opposite to the first ridge portion 31.

[0191] The first edge portion 31 is, for example, curved. When viewed along axis O, the tangent to the first edge portion 31 is designated as the first tangent 41. The second edge portion 32 is, for example, curved. When viewed along axis O, the tangent to the second edge portion 32 is designated as the second tangent 42. The corner edge portion 33 is, for example, curved. When viewed along axis O, the tangent to the corner edge portion 33 is designated as the third tangent 43.

[0192] Figure 12 The XI-XI line shown illustrates Figure 11 The location of the cross-section shown. Figure 11 The cross-section shown is perpendicular to the third tangent line 43. For example... Figure 11 As shown, in a cross-section perpendicular to the third tangent 43, the length of the second bottom portion 37 located between the corner edge portion 33 and the second rear blade portion 8 is defined as the third length L3. The third length L3 is, for example, 5 μm or more and 200 μm or less.

[0193] Figure 13 The cross-section shown is perpendicular to the first tangent 41. Hereinafter, the cross-section perpendicular to the first tangent 41 will also be referred to as the second cross-section CS2.

[0194] like Figure 13 As shown in the second cross-section CS2, the length of the second bottom portion 37 located between the first ridge portion 31 and the second rear cutting edge portion 8 is defined as the first length L1. In the second cross-section CS2, the first length L1 is the shortest distance between the connection point of the second rear cutting edge portion 8 and the second bottom portion 37 and the first ridge portion 31. The first length L1 is, for example, shorter than the third length L3. The first length L1 is, for example, more than 2 μm and less than 150 μm. The first length L1 can also be substantially the same length throughout the entire length of the first ridge portion 31.

[0195] Figure 14 The cross-section shown is perpendicular to the second tangent 42. Hereinafter, the cross-section perpendicular to the second tangent 42 will also be referred to as the third cross-section CS3.

[0196] like Figure 14As shown in the third cross-section CS3, the length of the second bottom portion 37 located between the second ridge portion 32 and the second rear cutting edge portion 8 is defined as the second length L2. In the third cross-section CS3, the second length L2 is the shortest distance between the connection point of the second rear cutting edge portion 8 and the second bottom portion 37 and the second ridge portion 32. The second length L2 may, for example, be the same as the first length L1. The second length L2 may, for example, be shorter than the third length L3. The second length L2 may also be substantially the same length throughout the entire length of the second ridge portion 32.

[0197] Compared to the wear resistance of the first rear cutting surface 7 formed of cBN sintered body, diamond, or special hard alloy, the second rear cutting surface 8 formed of hard alloy or high-speed steel has lower wear resistance. According to the rotary scraper 100 of the second embodiment, the tip portion 3 has a first bottom surface 36 and a second bottom surface 37. The first bottom surface 36 is in contact with the base portion 2. The second bottom surface 37 is connected to both the first rear cutting surface 7 and the first bottom surface 36. The second bottom surface 37 is disposed on the outer side relative to the base portion 2.

[0198] Therefore, in each of the plurality of cutting edges 6, the second flank face 8 is located inside the first flank face 7. This prevents the second flank face portion 8 from contacting the workpiece 90 during machining. As a result, wear on the flank face 4 can be suppressed. Specifically, wear in the tooth line direction of the flank face 4 can be suppressed.

[0199] According to the rotary scraper 100 of the second embodiment, it is possible to prevent the second flank face portion 8 from contacting the workpiece 90, thereby reducing the frictional force generated between each of the plurality of cutting edges 6 and the workpiece 90. Therefore, it is possible to suppress defects in each of the plurality of cutting edges 6.

[0200] As the chip thickness increases, the frictional force experienced by each of the multiple cutting edges 6 from the workpiece 90 increases. Therefore, the flank face 4 wears more easily as the chip thickness increases. The effect of suppressing wear on the flank face 4 increases as the length of the second bottom portion 37 in the direction perpendicular to the ridge line of the first flank face 7 and the second bottom portion 37 increases. On the other hand, if the length of the second bottom portion 37 is too long, the strength of the cutting tip 3 decreases. Therefore, it is necessary to set the length of the second bottom portion 37 according to the chip thickness.

[0201] Between two different points on the cutting edge 1, there are cases where the chip thickness is substantially the same and cases where the chip thickness is different. Specifically, the chip thickness varies depending on the specifications of the rotary scraper 100 and cutting conditions such as the cross angle θ. According to the rotary scraper 100 of the second embodiment, the first length L1 (refer to...) Figure 12 ) and the second length L2 (refer to Figure 13Therefore, when the chip thickness is substantially the same between two different points on the cutting edge 1, wear on the flank face 4 can be effectively suppressed.

[0202] (A variation of the second embodiment) Next, a variation of the second embodiment will be described. Figure 15 express Figure 13 The cross-section shown. Figure 16 express Figure 14 The cross-section shown.

[0203] like Figure 15 as well as Figure 16 As shown, the first length L1 and the second length L2 can also be different. For example, the first length L1 can be shorter than the second length L2. The first length L1 can be, for example, 0 μm. From another perspective, it is also possible that in the second section CS2, the first rear cutting surface 7 and the second rear cutting surface 8 are smoothly connected, and in the third section CS3, a second bottom surface 37 is provided between the first rear cutting surface 7 and the second rear cutting surface 8. The second length L2 can also be longer than the third length L3 (see reference). Figure 11 )long.

[0204] Conversely, the first length L1 can also be longer than the second length L2. The first length L1 can also be longer than the third length L3 (see reference). Figure 11 The second length L2 can be, for example, 0 μm. Alternatively, in the third section CS3, the first rear cutting surface 7 and the second rear cutting surface 8 can be smoothly connected, and in the second section CS2, a second bottom surface 37 can be provided between the first rear cutting surface 7 and the second rear cutting surface 8.

[0205] According to the modified example of the second embodiment, the rotary scraper 100 can effectively suppress wear on the back face 4 when the thickness of the chip is different between two different points on the cutting edge 1.

[0206] (Third implementation method) Next, the structure of the rotary scraper 100 according to the third embodiment will be described. The rotary scraper 100 according to the third embodiment differs from the rotary scraper 100 according to the first embodiment mainly in that it has a coating 19; otherwise, it is substantially the same as the rotary scraper 100 according to the first embodiment. Hereinafter, the description will focus on the differences from the rotary scraper 100 according to the first embodiment.

[0207] Figure 17 express Figure 5 The cross-section shown. (As shown) Figure 17 As shown, the rotary scraper 100 may also have a coating 19.

[0208] The coating 19 covers at least a portion of the tip portion 3. Specifically, the coating 19 covers the first flank face 7. The coating 19 may also cover the rake face 5. The coating 19 may also cover a portion of the base portion 2. Specifically, the coating 19 may also cover the second flank face 8. It should be noted that the coating 19 may not cover the rake face 5. The coating 19 is, for example, composed of at least one element selected from the group consisting of Ti (titanium), Zr (zirconium), Hf (hafnium), V (vanadium), Nb (niobium), Ta (tantalum), Cr (chromium), Mo (molybdenum), W (tungsten), Al (aluminum), and Si (silicon), and at least one element selected from the group consisting of C (carbon), N (nitrogen), O (oxygen), and B (boron).

[0209] According to the rotary scraper 100 of the third embodiment, the coating 19 covers at least a portion of the blade tip 3. This suppresses wear on the blade tip 3.

[0210] (Fourth Implementation) Next, the structure of the rotary scraper 100 according to the fourth embodiment will be described. The rotary scraper 100 according to the fourth embodiment differs from the rotary scraper 100 according to the first embodiment mainly in the shape of the helical gear; otherwise, it is substantially the same as the rotary scraper 100 according to the first embodiment. Hereinafter, the description will focus on the differences from the rotary scraper 100 according to the first embodiment.

[0211] like Figures 18 to 20 As shown, the rotary scraper 100 can also be in the shape of a helical gear. Specifically, the extension direction of each of the multiple cutting edges 6 can also be inclined relative to the axis O in the rotational direction R. Figure 19 as well as Figure 20 As shown, when viewed along axis O, the rake face 5 is positioned relative to the first rear end face 61 in the direction of rotation R. A rotary scraper 100 with a helical gear-like shape is used to form a spur gear on the workpiece.

[0212] like Figure 18 As shown, the second front end face 52 can also be formed by a plurality of first inclined surfaces 58 and a plurality of second inclined surfaces 59. The plurality of first inclined surfaces 58 are connected to one of the plurality of rake faces 5 via a connecting surface 66 (see reference). Figure 6 as well as Figure 7 The two inclined surfaces 59 are respectively disposed between two adjacent first inclined surfaces 58. The two inclined surfaces 59 are respectively connected to one of the multiple flank faces 4. The edges of the two inclined surfaces 59 and the flank face 4 form part of the bottom 9.

[0213] exist Figure 21In the diagram, the dashed line represents the boundary line between the first bottom surface 36 and the second bottom surface 37. For ease of explanation, in... Figure 21 The boundary lines between the tool tip layer 21 and the cemented carbide layer 22, as well as the boundary lines between the cemented carbide layer 22 and the solder layer 23, are not shown in the diagram. Figure 21 As shown, when viewed from below, a portion of the corner cutting edge 13 can also be straight. Similarly, when viewed from below, a portion of the corner edge 33 can also have a straight shape. For ease of explanation, in... Figure 21 The base portion 2 is not shown in the diagram.

[0214] Figure 22 express Figure 13 The cross-section shown. (As shown) Figure 22 As shown, in the second cross-section CS2, the first rear cutting edge 7 is inclined relative to the first direction 101 in a direction from the first bottom surface 36 toward the second bottom surface 37. In the second cross-section CS2, the second rear cutting edge 8 is inclined relative to the first direction 101 in a direction from the first bottom surface 36 toward the second bottom surface 37.

[0215] Figure 23 express Figure 14 The cross-section shown. (As shown) Figure 23 As shown, in the third cross-section CS3, the rake face 5 is inclined in the first direction 101 relative to the plane perpendicular to the axis O. Specifically, the rake face 5 is inclined in such a way that the distance between the rake face 5 and the first bottom surface 30 increases as it moves away from the second cutting edge 12.

[0216] like Figure 24 As shown, when viewed perpendicularly to axis O and from the outermost point 89 towards axis O, edge 88 can also be inclined relative to axis O. When viewed perpendicularly to axis O and from the outermost point 89 towards axis O, the angle between edge 88 and axis O is the twist angle φ2. It should be noted that... Figure 19 The direction of arrow E is perpendicular to axis O and extends from the outermost point 89 towards axis O. For ease of explanation, in... Figure 24 Only one blade section 6 is shown in the diagram.

[0217] The torsion angle φ2 is, for example, greater than 0° and less than 40°. The torsion angle φ2 can be, for example, greater than 5° or greater than 15°. The torsion angle φ2 can be, for example, less than 35° or less than 30°.

[0218] Sometimes, a rotary scraper 100 is used to perform grooving on the workpiece. Grooving is a process that forms a groove on the workpiece by bringing the cutting edge 1 into contact with the surface of the workpiece. If the twist angle φ2 is too large, during grooving, the chips, which become hot due to cutting, brush against the rake face 5 before their temperature drops. Consequently, excessive thermal damage occurs to the portion of the tool tip 3 near the multiple cutting edges 1. This results in a short tool life.

[0219] According to the rotary scraper 100 of the fourth embodiment, the torsion angle φ2 is 40° or less. Therefore, during grooving, the chips are easily discharged in a direction perpendicular to the axis O. Consequently, hot chips are less likely to rub against the rake face 5. As a result, thermal damage to the portion of the tool tip 3 near the plurality of cutting edges 1 can be reduced. Consequently, wear on the tool tip 3 can be suppressed.

[0220] (Fifth Implementation) Next, the structure of the rotary scraper 100 according to the fifth embodiment will be described. The rotary scraper 100 according to the fifth embodiment differs from the rotary scraper 100 according to the first embodiment mainly in that the shaft portion 10 is provided with a through hole; otherwise, it is substantially the same as the rotary scraper 100 according to the first embodiment. Hereinafter, the description will focus on the differences from the rotary scraper 100 according to the first embodiment.

[0221] like Figure 25 As shown, a recess 95 may also be provided on the first front end face 51. The axis O passes through the recess 95. The first front end face 51 surrounds the axis O. The shape of the first front end face 51 is annular.

[0222] The shaft portion 10 has a bottom surface (second bottom surface 53) with a recess 95. The second bottom surface 53 is formed by the base portion 2. A first through hole 96, a second through hole 97, and a plurality of fastening holes 98 are provided on the second bottom surface 53.

[0223] The first through hole 96 is tapered. Therefore, when the rotary scraper 100 is installed on the tool spindle (not shown), seizing (sticking) can be suppressed. This allows the rotary scraper 100 to be smoothly installed on the tool spindle. The second through hole 97 serves as an anti-rotation part. Specifically, by inserting a portion of the tool spindle into the second through hole 97, rotation of the rotary scraper 100 relative to the tool spindle can be prevented. Screws (not shown) for fastening the rotary scraper 100 to the tool spindle are installed in the plurality of fastening holes 98.

[0224] Figure 26 express Figure 4 The cross-section shown. (As shown) Figure 26As shown, axis O passes through the first through hole 96. The first through hole 96 penetrates the second bottom surface 53 and the third rear end surface 63. The base portion 2 forms an inner peripheral surface 54. The inner peripheral surface 54 forms the first through hole 96.

[0225] The first through hole 96 extends along the axis O. The diameter of the first through hole 96 increases with distance from the second bottom surface 53. From another perspective, the distance between the axis O and the inner circumferential surface 54 increases with distance from the second bottom surface 53.

[0226] Multiple fastening holes 98 penetrate the second bottom surface 53 and the third rear end surface 63, respectively. The multiple fastening holes 98 extend along the second direction 102. The second through hole 97 (see reference) Figure 25 It connects the second bottom surface 53 and the third rear end surface 63.

[0227] It should be noted that, while the structure of the rotary scraper 100 having multiple blade tips 3 has been described above, the structure of the rotary scraper 100 disclosed herein is not limited to the structure described above. Specifically, the blade tips 3 may also be formed from a single integral component. For example, the shape of the blade tips 3 may also be annular.

[0228] The cutting tip 3 can also be attached and detached from the base portion 2. Alternatively, the cutting tip 3 and the base portion 2 can be separate. In the case where the cutting tip 3 and the base portion 2 are separate, the cutting tip 3 may not have a brazing filler layer 23. In this case, the carbide layer 22 is in contact with the seat surface 20 of the base portion 2. For example, if the cutting tip 3 is formed of multiple parts, the cutting tip 3 can also be multiple non-regrinding inserts.

[0229] Example 1 (Sample preparation) The influence of the structure of cBN sintered bodies on tool life was investigated. First, rotary scrapers 100 for samples 1-1 to 1-19 were prepared. The rotary scrapers 100 for samples 1-1 to 1-17 are examples. The rotary scrapers 100 for samples 1-18 and 1-19 are comparative examples.

[0230] In samples 1-1 to 1-17, the blade tip layer 21 is formed from cBN sintered body. In sample 1-18, the blade tip layer 21 is formed from TiN. In sample 1-19, the blade tip layer 21 is formed from cemented carbide.

[0231] In samples 1-1 to 1-14, the cBN particle content of the cBN sintered body was set to be 50% or more and 100% or less. In samples 1-15 to 1-17, the cBN particle content of the cBN sintered body was set to be 15% or more and 45% or less.

[0232] In samples 1-1 to 1-12 and 1-15 to 1-17, the average particle size of cBN particles was greater than 0.01 μm and less than 3 μm. In samples 1-13 and 1-14, the average particle size of cBN particles was set to greater than 4 μm.

[0233] In samples 1-1 to 1-3 and 1-11 to 1-17, the bonding material is formed of TiN. In sample 1-4, the bonding material is formed of Co. In sample 1-5, the bonding material is formed of TiC. In sample 1-6, the bonding material is formed of TiCN. In sample 1-7, the bonding material is formed of Al2O3 and ZrO2. In sample 1-8, the bonding material is formed of AlN. In samples 1-9 and 1-10, no bonding material is present. In samples 1-1 to 1-19, the number of multiple cutting edges 6 is 30.

[0234] (Evaluation Method) The cutting evaluation was performed using the rotary scraper 100 described in Samples 1-1 to 1-19. Specifically, the rotary scraper 100 was used to perform grooving on the workpiece. The workpiece was formed of hardened steel. Specifically, the workpiece was formed of chromium-molybdenum steel equivalent to SCM415 as specified in JIS G4053:2016. The workpiece was subjected to carburizing and quenching as a surface treatment. The hardness of the workpiece was 60 HRC or higher.

[0235] The module of the workpiece is set to 1.5. The pressure angle of the workpiece is set to 20°. The number of teeth of the workpiece is set to 68.

[0236] In grooving, the sliding speed is set to 80 m / min. The depth of cut is set to 0.05 mm. The feed rate is set to 0.03 mm / rev. The cooling condition is WET (water-soluble). The cross angle θ is set to 25°. It should be noted that the sliding speed is the relative speed of the scraper with respect to the workpiece at the intersection of the pitch circle of the workpiece and the pitch circle of the scraper 100. The depth of cut is the amount of cut along the tooth height direction of the workpiece. The feed rate is the amount of movement of the scraper per revolution of the workpiece.

[0237] The tool life is defined as the point at which defects occur on the portion of the rotary scraper 100 near the cutting edge 1, or the point at which the maximum flank wear width reaches 0.2 mm. The cutting time until the tool life is reached is measured. It should be noted that the maximum flank wear width is the maximum wear width along the extension direction of the edge 88 of the flank 4.

[0238] (Evaluation Results)

[0239] The evaluation value column in Table 1 lists the relative evaluation value for the cutting time until the tool life is reached in Sample 1-1, which is set to 100%. As shown in Table 1, in the samples (Sample 1-18, Sample 1-19) where the tool tip layer 21 is not formed from cBN sintered material, the evaluation value is below 20%.

[0240] On the other hand, in samples (samples 1-1 to 1-17) where the blade tip layer 21 is formed from cBN sintered body, the evaluation value is 30% or more. In addition, in samples (samples 1-1 to 1-12) where the cBN particle content is 50% or more and the average particle size of cBN particles is 3 μm or less, the evaluation value is 60% or more.

[0241] As described above, compared to the comparative examples, the samples according to the embodiments can extend tool life by suppressing defects in the cutting tip 3. Furthermore, the samples with a cBN particle content of 50% or more and an average cBN particle size of 3 μm or less can effectively extend tool life.

[0242] Example 2 (Sample preparation) The effects of the rake angle φ1 and the torsion angle φ2 on tool life were investigated. First, rotary scrapers 100 involved in samples 2-1 to 2-10 were prepared. The rotary scrapers 100 involved in samples 2-1 to 2-10 are examples.

[0243] In samples 2-1 to 2-8 and sample 2-10, the rake angle φ1 is 0° or higher and 40° or lower. In sample 2-9, the rake angle φ1 is 50°. In samples 2-1 to 2-9, the torsion angle φ2 is 0° or higher and 40° or lower. In sample 2-10, the torsion angle φ2 is 50°. In samples 2-1 to 2-10, the number of multiple cutting edges 6 is 30.

[0244] (Evaluation Method) The cutting evaluation was performed using the rotary scraper 100 described in Samples 2-1 to 2-10. Grooving was performed on the workpiece using the rotary scraper 100. The workpiece was formed of hardened steel. Specifically, the workpiece was formed of chromium-molybdenum steel equivalent to SCM415 as specified in JIS G 4053:2016. The workpiece was subjected to carburizing and quenching as a surface treatment. The hardness of the workpiece was 60 HRC or higher.

[0245] The module of the workpiece is set to 1.5. The pressure angle of the workpiece is set to 20°. The number of teeth of the workpiece is set to 68.

[0246] In grooving, the sliding speed is set to 80 m / min. The depth of cut is set to 0.05 mm. The feed rate is set to 0.03 mm / rev. The cooling condition is set to WET (water-soluble). The cross angle θ is set to 25°.

[0247] The tool life is defined as the point at which defects occur on the portion of the rotary scraper 100 near the cutting edge 1, or the point at which the maximum flank wear width reaches 0.2 mm. The cutting time until the tool life is reached is measured.

[0248] (Evaluation Results)

[0249] The evaluation values ​​column in Table 2 lists the relative evaluation values ​​for sample 2-2, where the cutting time until tool life is reached is set to 100%. As shown in Table 2, the evaluation value is 20% for sample 2-9 with a rake angle φ1 of 50° and 30% for sample 2-10 with a torsion angle φ2 of 50°.

[0250] On the other hand, for samples with an anterior angle φ1 of 40° or less and a torsion angle φ2 of 40° or less (samples 2-1 to 2-8), the evaluation value was 60% or more. In addition, for samples with an anterior angle φ1 of 5° or more and 15° or less (samples 2-2 to 2-6), the evaluation value was 100% or more.

[0251] As described above, by making the rake angle φ1 less than 40° and the torsion angle φ2 less than 40°, wear on the cutting tip 3 can be suppressed, and tool life can be extended. Furthermore, by making the rake angle φ1 more than 5° and less than 15°, wear on the cutting tip 3 can be effectively suppressed.

[0252] Example 3 (Sample preparation) The influence of the diamond structure forming the tip layer 21 on tool life was investigated. First, rotary scrapers 100 involving samples 3-1 to 3-11 were prepared. Samples 3-1 to 3-10 are examples. Sample 3-11 is a comparative example.

[0253] In samples 3-1 to 3-10, the tip layer 21 is formed of diamond. Specifically, in samples 3-1 to 3-4 and samples 3-7 to 3-10, the tip layer 21 is formed of PCD. In sample 3-5, the tip layer 21 is formed of BLPCD. In sample 3-6, the tip layer 21 is formed of single-crystal diamond. In sample 3-11, the tip layer 21 is formed of cemented carbide.

[0254] In samples 3-1 to 3-6 and 3-8 to 3-10, the diamond particle content was set to be above 80% and below 100%. In sample 3-7, the diamond particle content was set to 70%. In samples 3-1 to 3-5 and 3-7 to 3-9, the average particle size of the diamond particles was set to be above 0.01 μm and below 50 μm. In sample 3-10, the average particle size of the diamond particles was set to 100 μm.

[0255] In samples 3-1 to 3-4 and 3-7 to 3-10, the bonding phase is formed by cobalt. In samples 3-5 and 3-6, diamond does not have a bonding phase.

[0256] In samples 3-1 to 3-7 and 3-9 to 3-11, the rake angle φ1 is set to 10°. In sample 3-8, the rake angle φ1 is set to 50°. In samples 3-1 to 3-8, 3-10, and 3-11, the torsion angle φ2 is set to 20°. In sample 3-9, the torsion angle φ2 is set to 50°. In samples 3-1 to 3-11, the number of multiple cutting edges 6 is 30.

[0257] (Evaluation Method) The cutting evaluation was performed using the rotary scraper 100 described in samples 3-1 to 3-11. Specifically, the rotary scraper 100 was used to perform grooving on the workpiece. The workpiece was made of PEEK (polyetheretherketone). The Rockwell hardness (R grade) was 120.

[0258] The module of the workpiece is set to 1.5. The pressure angle of the workpiece is set to 20°. The number of teeth of the workpiece is set to 68.

[0259] In grooving, the sliding speed is set to 100 m / min. The depth of cut is set to 0.2 mm. The feed rate is set to 0.06 mm / rev. The cooling condition is set to WET (water-soluble). The cross angle θ is set to 25°.

[0260] The tool life is defined as the point at which defects occur on the portion of the rotary scraper 100 near the cutting edge 1, or the point at which the maximum flank wear width reaches 0.2 mm. The cutting time until the tool life is reached is measured.

[0261] (Evaluation Results)

[0262] In the evaluation value column of Table 3, the relative evaluation value is recorded with the cutting time until the tool life is reached in sample 3-1 set to 100%. As shown in Table 3, in sample 3-11 where the tip layer 21 is not formed of diamond, the evaluation value is 5%. On the other hand, in samples (samples 3-1 to 3-10) where the tip layer 21 is formed of diamond, the evaluation value is 10% or more.

[0263] As described above, the tool life is extended according to the sample according to the embodiment compared to the sample involved in the comparative example. It is believed that the strength of the tip layer 21 is improved in the sample involved in the embodiment.

[0264] As shown in Table 3, in samples 3-7 with a diamond particle content of 70%, the evaluation value was 40%. On the other hand, in samples with a diamond particle content of 80% or more (samples 3-1 and 3-3), the evaluation value was 100% or more. As mentioned above, by increasing the diamond particle content to 80% or more, tool life can be extended. It is believed that by increasing the diamond particle content to 80% or more, the strength of the tip layer 21 is improved.

[0265] As shown in Table 3, in samples 3-10 with an average diamond particle size of 100 μm, the evaluation value was 10%. On the other hand, in samples (samples 3-3 and 3-4) with an average diamond particle size of 50 μm or less, the evaluation value was over 105%. As mentioned above, by making the average diamond particle size less than 100 μm, tool life can be extended. It is believed that in samples 3-10, the average diamond particle size was 100 μm, resulting in poor sintering of the diamond particles.

[0266] As shown in Table 3, the evaluation value for samples 3-8 with a rake angle φ1 of 50° was 25%. On the other hand, the evaluation value for sample 3-3 with a rake angle φ1 of 10° was 105%. As described above, by keeping the rake angle φ1 below 40°, the tool life can be extended.

[0267] As shown in Table 3, the evaluation value for samples 3-9 with a torsion angle φ2 of 50° is 35%. On the other hand, the evaluation value for sample 3-3 with a torsion angle φ2 of 20° is 105%. As described above, by keeping the torsion angle φ2 below 40°, the tool life can be extended.

[0268] As shown in Table 3, in the samples (samples 3-5 and 3-6) where the diamond is BLPCD or single-crystal diamond, the evaluation value is above 130%. As mentioned above, by using BLPCD or single-crystal diamond, tool life can be extended.

[0269] Example 4 (Sample preparation) The influence of the structure of the cemented carbide forming the tip layer 21 on tool life was investigated. First, rotary scrapers 100 involved in samples 4-1 to 4-21 were prepared. The rotary scrapers 100 involved in samples 4-1 to 4-16 are examples. The rotary scrapers 100 involved in samples 4-17 to 4-21 are comparative examples.

[0270] <Making the tip of the knife>

[0271]

[0272]

[0273] The blade tip layer 21 for each sample was prepared using the conditions shown in Tables 4 to 6. Specifically, firstly, WC powder, Co powder, first element powder, NiCr powder, and TiNbCN powder were prepared as raw material powders (preparation step). As first element powders, silicon (Si) powder, rhenium (Re) powder, phosphorus (P) powder, germanium (Ge) powder, tin (Sn) powder, ruthenium (Ru) powder, osmium (Os) powder, iridium (Ir) powder, and platinum (Pt) powder were prepared. The average particle size of each powder was 1 μm.

[0274] The raw material powders were mixed using a grinder in the proportions shown in Table 4 to produce a mixed powder (mixing process). The mixing time was 10 hours. The proportions (mass%) of the raw material powders shown in Table 1 are based on the condition that the total mixed powder is 100% by mass.

[0275] Next, the mixed powder is pressed to form a molded body in the shape of the blade tip layer 21 (forming process). Then, the molded body is heated to the temperature recorded in the "Holding Temperature" column at the heating rate specified in Table 5. It is held at this temperature for the time specified in the "Holding Time" column (sintering process). After the sintering process, the molded body is cooled to 800°C at the cooling rate specified in the "Cooling Rate" column of Table 5 (first cooling process).

[0276] In samples 4-1, 4-3 to 4-21, a HIP process and a second cooling process were performed. In the HIP process, the pressure recorded in the "Pressure" column and the temperature recorded in the "Temperature" column of Table 6 were maintained for the time recorded in the "Time" column.

[0277] Following the HIP process, a second cooling process is performed. Specifically, the sample is cooled to 800°C at the cooling rate specified in the "Cooling Rate" column of Table 6. After cooling to 800°C, the molded body is slowly cooled to create the blade tip layer 21 for each sample.

[0278] In samples 4-1 to 4-16, the blade tip layer 21 is formed of the aforementioned special cemented carbide. The content of the bonding phase in the special cemented carbide is 0.73% or more and 27.20% or less. The bonding phase contains cobalt and the first element. The cobalt content in the bonding phase is 50% or more and 99% or less.

[0279] In samples 4-17 to 4-21, the tip layer 21 is formed of a cemented carbide that is not the special cemented carbide described above. Specifically, in samples 4-17 and 4-18, the bonding phase of the cemented carbide forming the tip layer 21 does not contain the first element. In sample 4-19, the cobalt content in the bonding phase is 48%. In sample 4-20, the bonding phase content in the cemented carbide is 0.6%. In sample 4-21, the bonding phase content in the cemented carbide is 28.8%. In samples 4-1 to 4-21, the number of the plurality of cutting edges 6 is 30.

[0280] (Evaluation Method) The cutting evaluation was performed using the rotary scraper 100 described in Samples 4-1 to 4-21. Specifically, the rotary scraper 100 was used to perform grooving on the workpiece. The workpiece was formed of hardened steel. Specifically, the workpiece was formed of chromium-molybdenum steel equivalent to SCM415 as specified in JIS G4053:2016. The workpiece was subjected to carburizing and quenching as a surface treatment. The hardness of the workpiece was 60 HRC or higher.

[0281] The module of the workpiece is set to 1.5. The pressure angle of the workpiece is set to 20°. The number of teeth of the workpiece is set to 68.

[0282] In grooving, the sliding speed is set to 80 m / min. The depth of cut is set to 0.05 mm. The feed rate is set to 0.03 mm / rev. The cooling condition is set to WET (water-soluble). The cross angle θ is set to 25°.

[0283] The tool life is defined as the point at which defects occur on the portion of the rotary scraper 100 near the cutting edge 1, or the point at which the maximum flank wear width reaches 0.2 mm. The cutting time until the tool life is reached is measured.

[0284] (Evaluation Results)

[0285] Table 7 lists the relative evaluation values ​​for samples 4-2, where the cutting time until tool life is reached is set to 100%. As shown in Table 7, in samples (samples 4-17 to 4-21) where the tip layer 21 is not formed of special cemented carbide, the evaluation value is 40% or less. On the other hand, in samples (samples 4-1 to 4-16) where the tip layer 21 is formed of special cemented carbide, the evaluation value is 90% or more.

[0286] As described above, the tool life can be extended according to the sample according to the embodiment compared to the sample involved in the comparative example. It is believed that by making the tip layer 21 into a special cemented carbide, the wear resistance of the tip layer 21 can be improved.

[0287] The embodiments and examples disclosed herein should be considered exemplary in all respects, and not restrictive. The scope of the invention is defined not by the foregoing embodiments and examples, but by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

[0288] Explanation of reference numerals in the attached figures 1: Cutting edge; 2: Base body; 3: Tool tip; 4: Rake face; 5: Front face; 6: Cutting edge; 7: First flank face; 8: Second flank face; 9: Bottom; 10: Shaft; 11: First cutting edge; 12: Second cutting edge; 13: Corner cutting edge; 19: Coating; 20: Seat surface; 21: Tool tip layer; 22: Carbide layer; 23: Brazing filler layer; 26: First boundary line; 27: Second boundary line; 28: Third edge Boundary line; 29: Fourth boundary line; 30: First bottom surface; 31: First edge portion; 32: Second edge portion; 33: Corner edge portion; 36: First bottom surface; 37: Second bottom surface; 41: First tangent; 42: Second tangent; 43: Third tangent; 51: First front end surface; 52: Second front end surface; 53: Second bottom surface; 54: Inner peripheral surface; 55: Side wall surface; 56: First outer peripheral surface; 57: Second outer peripheral surface; 58: First inclination Surface; 59: Second inclined surface; 61: First rear end face; 62: Second rear end face; 63: Third rear end face; 66: Connecting surface; 71: First part; 72: Second part; 73: First corner face; 81: Third part; 82: Fourth part; 83: Second corner face; 88: Edge; 90: Workpiece to be cut; 91: Machined surface; 95: Recess; 96: First through hole; 97: Second through hole; 98: Fastening hole; 99: Straight Line; 100: Rotary scraper; 101: First direction; 102: Second direction; A: Radius of curvature; B, F: Arrows; C: Rotation axis; CS1: First section; CS2: Second section; CS3: Third section; H1: First thickness; H2: Second thickness; H3: Third thickness; L1: First length; L2: Second length; L3: Third length; O: Axis; R: Rotation direction; θ: Cross angle; φ1: Front angle; φ2: Twist angle.

Claims

1. A rotary scraper, wherein the rotary scraper rotates about an axis and a plurality of cutting edges are arranged in a circular pattern about the axis, wherein, The rotary scraper has the following features: The base; and The blade tip is connected to the base portion and is arranged with the base portion in a first direction along the axis toward the front of the rotary scraper. The base portion is formed of either cemented carbide or high-speed steel. The blade tip includes: The blade tip layer has the plurality of cutting edges formed thereon; and A cemented carbide layer is disposed between the cutting edge layer and the substrate. The blade tip layer is formed from any one of cubic boron nitride sintered body, diamond, and special hard alloy. The special hard alloy has tungsten carbide particles and a cobalt-containing composite phase. In the special cemented carbide, the percentage of the volume of the bonding phase divided by the total volume of the special cemented carbide is 0.7% or more and 28% or less. In the combined phase, the percentage of cobalt mass divided by the total mass of the combined phase is 50% or more. The bonding phase further comprises at least one element selected from the group consisting of silicon, phosphorus, germanium, tin, rhenium, ruthenium, osmium, iridium, and platinum.

2. The rotary scraper according to claim 1, wherein, The rotary scraper has the following features: The shaft portion has an outer peripheral surface disposed around the axis; and Multiple cutting edges are connected to the shaft portion and extend radially outward from the outer peripheral surface. The plurality of cutting edges each form one of the plurality of cutting edges. The plurality of cutting edges respectively include: The first rear cutting edge is formed by the cutting tip and is connected to the plurality of cutting edges; and The second rear blade facet is formed by the base portion and is disposed relative to the first rear blade facet along a second direction, which extends along the axis toward the rear of the rotary scraper. The blade tip has: The first bottom surface portion is in contact with the base portion; and The second bottom surface portion is connected to both the first rear blade surface portion and the first bottom surface portion, and is disposed on the outer side relative to the base portion. The edges of the first rear cutting surface and the second bottom surface have: First ridge section; The corner edge portion is connected to the first edge portion and is disposed on the radially outer side relative to the first edge portion; as well as The second ridge portion is connected to the corner ridge portion and is arranged in the rotational direction relative to the first ridge portion. In a cross-section perpendicular to the tangent of the first ridge portion when viewed along the axis, the length of the second bottom portion located between the first ridge portion and the second rear cutting edge portion is defined as a first length. In a cross-section perpendicular to the tangent of the second ridge portion when viewed along the axis, the length of the second bottom portion located between the second ridge portion and the second rear cutting edge portion is defined as a second length. The first length is the same as the second length.

3. The rotary scraper according to claim 1, wherein, The rotary scraper has the following features: The shaft portion has an outer peripheral surface disposed around the axis; and Multiple cutting edges are connected to the shaft portion and extend radially outward from the outer peripheral surface. The plurality of cutting edges each form one of the plurality of cutting edges. The plurality of cutting edges respectively include: The first rear cutting edge is formed by the cutting tip and is connected to the plurality of cutting edges; and The second rear blade facet is formed by the base portion and is disposed relative to the first rear blade facet along a second direction, which extends along the axis toward the rear of the rotary scraper. The blade tip has: The first bottom surface portion is in contact with the base portion; and The second bottom surface portion is connected to both the first rear blade surface portion and the first bottom surface portion, and is disposed on the outer side relative to the base portion. The edges of the first rear cutting surface and the second bottom surface have: First ridge section; The corner edge portion is connected to the first edge portion and is disposed on the radially outer side relative to the first edge portion; as well as The second ridge portion is connected to the corner ridge portion and is arranged in the rotational direction relative to the first ridge portion. In a cross-section perpendicular to the tangent of the first ridge portion when viewed along the axis, the length of the second bottom portion located between the first ridge portion and the second rear cutting edge portion is defined as a first length. In a cross-section perpendicular to the tangent of the second ridge portion when viewed along the axis, the length of the second bottom portion located between the second ridge portion and the second rear cutting edge portion is defined as a second length. The first length is different from the second length.

4. The rotary scraper according to claim 2 or 3, wherein, The plurality of cutting edges respectively include: The rake face, connected to the plurality of cutting edges, and formed by the tip layer; and The rear end face is located opposite the front face and is formed by the base portion. When viewed along the axis, the rear end face overlaps with the front end face.

5. The rotary scraper according to claim 2 or 3, wherein, The plurality of cutting edges respectively include: The rake face, connected to the plurality of cutting edges, and formed by the tip layer; and The rear end face is located opposite the front face and is formed by the base portion. When viewed along the axis, the rake face is positioned relative to the rear end face in the direction of rotation.

6. The rotary scraper according to any one of claims 1 to 5, wherein, The cutting tip includes a brazing filler layer disposed on the base portion. The cemented carbide layer is disposed on the brazing filler metal layer.

7. The rotary scraper according to any one of claims 1 to 6, wherein, In the first direction, the maximum thickness of the blade tip layer is more than 0.3 mm and less than 3 mm.

8. The rotary scraper according to any one of claims 1 to 7, wherein, The rotary scraper also has a coating covering at least a portion of the blade tip.

9. The rotary scraper according to any one of claims 1 to 8, wherein, In a cross-section perpendicular to the plurality of cutting edges, the radius of curvature of the plurality of cutting edges is greater than 10 μm and less than 40 μm.

10. The rotary scraper according to any one of claims 1 to 9, wherein, The blade tip layer is formed from the cubic boron nitride sintered body. The cubic boron nitride sintered body comprises cubic boron nitride particles. In the cubic boron nitride sintered body, The percentage of the value obtained by dividing the volume of the cubic boron nitride particles by the total volume of the cubic boron nitride sintered body is 50% or more and 100% or less. The cubic boron nitride particles have an average particle size of 0.01 μm or more and 3 μm or less.

11. The rotary scraper according to claim 10, wherein, In the cubic boron nitride sintered body, the percentage of the volume of the cubic boron nitride particles divided by the total volume of the cubic boron nitride sintered body is less than 100%. The cubic boron nitride sintered body includes a bonding material. The bonding material comprises at least one element selected from the group consisting of titanium, cobalt, aluminum, and zirconium.

12. The rotary scraper according to claim 1, wherein, The rotary scraper has the following features: The shaft portion has an outer peripheral surface disposed around the axis; and Multiple cutting edges are connected to the shaft portion and extend radially outward from the outer peripheral surface. The plurality of cutting edges each form one of the plurality of cutting edges. The plurality of cutting edges respectively include: The rake face, connected to the plurality of cutting edges, and formed by the tip layer; and The flank face is connected to the rake face via the plurality of cutting edges. In each of the plurality of cutting edges. When the point located at the outermost perimeter when viewed along the axis is defined as the outermost perimeter point, In a cross-section that includes the axis and passes through the outermost circumferential point, the angle between a straight line perpendicular to the axis and the rake face is greater than 0° and less than 40°. When viewed perpendicular to the axis and from the outermost circumference point toward the axis, the angle between the edge of the back face and the axis is greater than 0° and less than 40°.

13. The rotary scraper according to any one of claims 1 to 12, wherein, The blade tip layer is formed of the diamond. The diamond is a polycrystalline diamond containing multiple diamond particles. In the diamond, the percentage of the value obtained by dividing the volume of the plurality of diamond particles by the volume of the diamond as a whole is more than 80% and less than 100%.

14. The rotary scraper according to claim 13, wherein, The average particle size of the plurality of diamond particles is greater than 0.01 μm and less than 100 μm.

15. The rotary scraper according to any one of claims 1 to 12, wherein, The blade tip layer is formed of the diamond. The diamond is a single-crystal diamond.

Images