Cutting Tools

Abstract

The present invention provides a cutting tool with improved chip handling performance. The cutting edge component 20 includes: a first wall surface 20B1, which includes a concave surface that is recessed in a direction away from the intersection point P of the virtual plane IP and the corner 20C1 and close to the center of the cutting blade 10 when viewed from the end face in a direction opposite to the end face; a second wall surface 20B2, which includes a convex surface that is connected to the first wall surface 20B1 at a position away from the virtual plane IP and protrudes in a direction away from the center of the cutting blade 10 when viewed from the end face; a third wall surface 20B3, which includes a convex surface that is located at the second wall surface 20B1 relative to the virtual plane IP and protrudes in a direction away from the center of the cutting blade 10 when viewed from the end face; B2 is arranged on the opposite side of the virtual plane IP and is connected to the first wall 20B1, and is a convex surface that protrudes away from the center of the cutting blade 10 in the end face perspective; and the fourth wall 20B4 includes an area located between the first wall 20B1 and the intersection P in the end face perspective and is a convex surface that protrudes away from the center of the cutting blade 10 in the end face perspective, and, in the side perspective observed from the direction opposite to the side, it has a height smaller than the heights of the second wall 20B2 and the third wall 20B3.

Description

Technical Field

[0001] The invention relates to a cutting tool. Background Art

[0002] Conventionally, there are known techniques for improving chip disposability.

[0003] For example, Patent Document 1 discloses a chip breaker having a chip breaker wall surface that is convex at a position away from a virtual plane that is determined so as to bisect a corner portion.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Application Publication No. WO 2016 / 136694

[0007] Technical issues

[0008] However, when cutting is performed using the cutting insert described in Patent Document 1, it is sometimes difficult to properly handle the chips. In particular, it is known that when the depth of cut is increased, the chips may not be properly broken.

[0009] Therefore, an object of the present invention is to provide a cutting tool having improved chip disposability. Summary of the invention

[0010] The present application discloses a cutting tool. The cutting tool includes at least a cutting edge component. The cutting edge component includes: a cutting edge formed at the corner of the connecting portion connecting the end face and the side face; a first wall surface, including a concave surface formed by being arranged at a position through which a virtual plane determined in a manner of bisecting the corner passes, and being recessed in a direction away from the intersection of the virtual plane and the corner from the perspective of the end face observed from the direction opposite to the end face; a second wall surface, including a convex surface that is arranged in connection with the first wall surface at a position away from the virtual plane, and protruding in a direction opposite to the direction in which the concave surface is recessed from the perspective of the end face; a third wall surface, including a convex surface that is arranged at a position relative to the virtual plane and is located at a position opposite to the virtual plane; A convex surface is arranged to be connected to the first wall surface at a position opposite to the second wall surface and away from the virtual plane, and protrudes in the direction opposite to the direction in which the concave surface is sunken when viewed from the end face; and a fourth wall surface includes an area arranged between the first wall surface and the intersection point when viewed from the end face and an area through which the virtual plane passes, and protrudes in the direction opposite to the direction in which the concave surface is sunken when viewed from the end face, and, when viewed from the side face from a direction opposite to the side face, the fourth wall surface has a height smaller than those of the second wall surface and the third wall surface.

[0011] In the direction parallel to the virtual plane, when the direction from the cutting edge part or its center toward the corner is called the front, and the opposite direction is called the rear, the direction away from the intersection of the virtual plane and the corner is equivalent to the rear, and the direction opposite to the direction in which the concave surface is sunken is equivalent to the front. Therefore, it can be said that the first wall surface has a concave surface sunken toward the rear, and the second wall surface, the third wall surface, and the fourth wall surface each have a convex surface protruding toward the front.

[0012] In the cutting tool, a line that cuts the fourth wall surface on a second virtual plane perpendicular to the virtual plane may be in the shape of a circular arc or an elliptical arc.

[0013] In the cutting tool, a cutting edge component can also be set so that the cross-section of the cutting edge component cut on the virtual plane appears as: the corner or the cutting edge; a chip breaker bottom surface set between the corner or the cutting edge and the fourth wall; the fourth wall connected to the chip breaker bottom surface and moving upward as it moves away from the corner or the cutting edge; a connecting surface connected to the fourth wall; the first wall connected to the connecting surface and moving upward as it moves away from the corner or the cutting edge; and a boss surface connected to the first wall and having a height greater than the height of the fourth wall.

[0014] The cutting tool may include a cutting insert including the cutting edge component and a base insert on which the cutting edge component is mounted, wherein the cutting insert includes a through hole having a central axis located within the virtual plane formed on the base insert.

[0015] The cutting tool may also include a cutting insert, which includes the cutting edge component and a base insert on which the cutting edge component is mounted, wherein the cutting insert is formed into a polygon from the perspective of the end face observed from a direction opposite to the end face, and the corner is formed at the vertex of the polygon.

[0016] The cutting tool may further include a tool holder for holding the cutting edge component.

[0017] The cutting tool may be a turning tool, and may be used for cutting processes such as outer diameter machining, end face machining, profiling machining, inner diameter machining, etc.

[0018] The present application discloses a cutting edge component. The cutting edge component includes: a cutting edge formed at a corner connecting an end face and a side face; a first wall surface, including a concave surface formed by being arranged at a position through which a virtual plane determined by bisecting the corner passes, and being recessed in a direction away from the intersection of the virtual plane and the corner in an end face perspective viewed from a direction opposite to the end face; a second wall surface, including a convex surface arranged in connection with the first wall surface at a position away from the virtual plane and protruding outward in an end face perspective; a third wall surface, including a convex surface arranged in connection with the first wall surface at a position away from the virtual plane and located on the opposite side of the second wall surface relative to the virtual plane, and protruding outward in an end face perspective; and a fourth wall surface, including a convex surface arranged in an area between the first wall surface and the intersection in an end face perspective and an area through which the virtual plane passes, and protruding outward in an end face perspective, and in a side face perspective viewed from a direction opposite to the side face, the fourth wall surface has a height smaller than the heights of the second wall surface and the third wall surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a perspective view of a cutting insert according to the embodiment.

[0020] Figure 2 It is an enlarged perspective view of the cutting insert according to the embodiment.

[0021] Figure 3 It is a plan view (top view) of the cutting insert according to the embodiment.

[0022] Figure 4 It is a front view of the cutting insert involved in an embodiment.

[0023] Figure 5 This is a cross-sectional view of the cutting insert according to the embodiment cut along a virtual plane.

[0024] Figure 6 It is a perspective view of a cutting tool according to an embodiment.

[0025] Main component symbols

[0026] Cutting blade 10

[0027] Corner 10C1, 10C2

[0028] Upper end surface 10U

[0029] Lower end surface 10L

[0030] Through hole 10H

[0031] Cutting edge component 20

[0032] First wall surface to fourth wall surface 20B1 to 20B4

[0033] Corner 20C1

[0034] Straight section 20C2, 20C3

[0035] Chip breaker bottom 20G

[0036] Lower end surface 20L

[0037] Side 20S

[0038] 20T convex surface

[0039] Upper end surface 20U

[0040] Base blade 40

[0041] Handle 50

[0042] Turning tools 100

[0043] Center axis AX

[0044] Virtual plane IP DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments are examples for describing the present invention, and the present invention is not limited to the embodiments.

[0046] Figure 1 is a perspective view of a cutting insert 10 according to this embodiment. Figure 2 is equivalent to Figure 1 An enlarged perspective view of a region A of the cutting insert 10 is shown. Figure 3 This is a plan view of the cutting insert 10 as viewed from a direction opposite to the end surface. Figure 4 This is a front view of the cutting insert 10 as viewed from a direction opposite to the side surface, that is, a direction parallel to a virtual plane IP described later. Figure 5 This is a cross-sectional view of the cutting insert 10 cut along a virtual plane IP.

[0047] The cutting insert 10 can be formed into a polygonal shape when viewed from an end face perspective (top view) from a direction opposite to the upper end face 10U (or the boss face 20T of the cutting edge component 20 to the upper end face 40U of the base insert 40). Figure 3 As shown in the end view of FIG. 1 , the cutting insert 10 is formed into a rhombus shape having two acute angles (e.g., 80 degrees) of corners 10C1 and 10C2 and two obtuse angles (e.g., 100 degrees). As shown in the figure, the cutting insert 10 has an upper end face 10U and a lower end face 10L ( Figure 4), the cutting insert 10 is formed symmetrically by rotating 180 degrees with respect to the central axis AX of the through hole 10H.

[0048] The cutting insert 10 has a base insert 40, and a cutting edge component 20 consisting of two ultrahigh pressure sintered bodies fixed to the base insert 40 is provided at a position corresponding to the corner 10C1 and the corner 10C2. Therefore, after the cutting edge of one of the cutting edge components 20 is worn, the other cutting edge component 20 can be used by replacing the corner 10C1 with the corner 10C2.

[0049] Alternatively, instead of using a cutting insert, a cutting blade member may be fixed to a tool holder such as a cutter or an end mill (an example of a cutting tool) by brazing or the like to provide a cutting tool.

[0050] The cutting edge component 20 in this embodiment includes a sintered body containing cubic boron nitride and a coating film covering the surface of the sintered body. The coating film can be deposited on the surface of the sintered body by, for example, PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition). However, the coating film may not be covered on the cutting edge component 20. In addition, the cutting edge component 20 may also be composed of diamond or the like.

[0051] The structure of the cutting blade member 20 is described in detail below. In addition, for convenience, in the direction of the central axis AX of the through hole 10H, sometimes from the center of the cutting insert 10 toward the shank frame 50 ( Figure 6 ) is referred to as the direction of the lower end surface 10L of the cutting insert 10, which is the seating surface of the cutting insert 10. It is referred to as the direction of the center axis AX, or simply the direction of the lower end surface 10L. The opposite direction of the upper end surface 10U of the cutting blade 20 is referred to as the direction of the center axis AX, or simply the direction of the upper end surface 10U. In addition, the end portion on the upper side (lower side) is sometimes referred to as the upper end (lower end) or the upper end portion (lower end portion). In addition, in the end view ( Figure 3 ), in the direction parallel to the virtual plane IP, the direction from the center of the cutting insert 10 toward the cutting edge component 20 installed at the corner 10C1 is sometimes referred to as the front, and the opposite direction toward the cutting edge component 20 installed at the corner 10C2 is referred to as the rear. In the present embodiment, the direction relative to the upper end surface 10U of the cutting insert 10 is roughly consistent with the direction of the central axis AX, and the direction relative to the side of the cutting insert 10 is roughly consistent with the direction perpendicular to the central axis AX.

[0052] The cutting edge component 20 has an upper end surface 20U corresponding to the surface above the central axis AX direction, a lower end surface 20L corresponding to the surface below the central axis AX direction, and a side surface 20S connecting the upper end surface 20U and the lower end surface 20L. Figure 2 As shown in FIGS. 1 and 10 , the cutting blade member 20 of the present embodiment is formed in a triangular prism shape with an upper end surface 20U as a top surface and a lower end surface 20L as a bottom surface.

[0053] The connecting portion is a portion connecting the upper end surface 20U and the side surface 20S. Figure 2 and Figure 3 As shown in the figure, the corner 20C1 corresponding to one vertex portion of the connection portion of the upper end face 20U and the side face 20S formed in a triangular shape from the end face perspective is formed in an arc shape. A circular arc corner cutting edge is formed on the corner 20C1. In the present embodiment, the central angle of the circular arc approximating the corner 20C1 is set to be, for example, greater than 25 degrees and less than 90 degrees (for example, 80 degrees). Straight line cutting edges are respectively formed on the straight line portion 20C2 and the straight line portion 20C3 respectively connected to the ends of the corner 20C1.

[0054] In the present embodiment, the cutting edge member 20 is formed to be plane-symmetrical with respect to a virtual plane IP that is determined by bisecting the corner portion 20C1. Figure 3 As shown in FIG. 1 and FIG. 2 , the upper end face 20U is formed into an isosceles triangle shape with the corner 20C1 as the vertex from the end face perspective. In addition, the virtual plane IP includes the central axis AX of the through hole 10H. In addition, the intersection point of the virtual plane IP and the corner 20C1 is defined as the intersection point P ( Figure 3 ).

[0055] like Figure 2 As shown, the upper end surface 20U includes a boss surface 20T, a chip breaker bottom surface 20G, and a chip breaker wall surface provided in a region connecting the chip breaker bottom surface 20G and the boss surface 20T.

[0056] The boss surface 20T is a surface formed perpendicularly to the center axis AX direction so that it is coplanar with the upper end surface 40U of the base blade 40 (i.e., has the same height based on the center axis AX direction). The boss surface 20T is equivalent to the surface of the cutting edge component 20 located at the upper end of the center axis AX direction, so it can also be called the top surface. The boss surface 20T of this embodiment has a region that is recessed to the rear in a manner that the distance from the intersection point P becomes larger in the region intersecting with the virtual plane IP, and two regions that protrude forward in a manner that the distance from the intersection point P in a direction parallel to the virtual plane IP becomes smaller in a region separated from the virtual plane IP in a manner that the region is sandwiched.

[0057] The chip breaker bottom surface 20G is a surface of the upper end surface 20U adjacent to the cutting edges including the corner cutting edge and the straight cutting edge, and at least a part thereof also functions as a rake face. The chip breaker bottom surface 20G is provided in a region below the boss surface 20T.

[0058] The chip breaker wall surface 20B is a surface provided in a region connecting the chip breaker bottom surface 20G and the boss surface 20T, and includes at least a first wall surface 20B1 , a second wall surface 20B2 , a third wall surface 20B3 , and a fourth wall surface 20B4 .

[0059] The first wall surface 20B1 is set at the position where the virtual plane IP passes, and is a concave surface formed by being concave in a direction away from the intersection point P (backward) from the end face perspective, or concave in a direction close to the center of the cutting insert 10 from the end face perspective, that is, the central axis AX. Figure 5 As shown in the cross-sectional view of , in the cross-sectional view cut by the virtual plane IP, the first wall surface 20B1 is formed to be inclined relative to the central axis AX direction in a manner that the distance from the intersection point P increases as it goes backward and the first wall surface 20B1 moves upward.

[0060] The second wall surface 20B2 is a convex surface directly or indirectly connected to the first wall surface 20B1 at a position away from the virtual plane IP. In addition, the second wall surface 20B2 is formed to protrude forward or outward, that is, in a direction away from the center of the cutting insert 10 in an end view, or in a direction close to the intersection point P or the side surface 20S in an end view. Figure 5 As shown in the cross-sectional view of , in the cross-sectional view cut by the virtual plane IP, the second wall surface 20B2 is formed to be inclined relative to the central axis AX direction in such a manner that the second wall surface 20B2 moves upward as the distance from the intersection point P increases.

[0061] The third wall surface 20B3 is a convex surface formed symmetrically with the second wall surface 20B2 on the opposite side of the second wall surface 20B2 relative to the virtual plane IP. That is, the second wall surface 20B2 and the third wall surface 20B3 are arranged on both sides of the virtual plane IP. Since the second wall surface 20B2 and the third wall surface 20B3 are formed symmetrically, the structure can be explained by replacing the second wall surface 20B2 with the third wall surface 20B3. Therefore, the explanation about the third wall surface 20B3 is omitted.

[0062] The fourth wall surface 20B4 is disposed in the region between the first wall surface 20B1 and the intersection point P in the end view, i.e., the region through which the virtual plane IP passes. The fourth wall surface 20B4 is a convex surface that protrudes in the direction away from the center of the cutting insert 10 in the end view, or in the direction close to the intersection point P or the side surface 20S in the end view. Figure 4 As shown in the side view of the fourth wall 20B4, the fourth wall 20B4 has a height smaller than the heights of the second wall 20B2, the third wall 20B3 and the first wall 20B1. In addition, the fourth wall 20B4 is formed to have a circular arc or an elliptical arc in a cross-sectional view cut by a plane (an example of a second virtual plane) perpendicular to the central axis AX. The circular arc or the elliptical arc is formed symmetrically with respect to the intersection line of the above-mentioned plane perpendicular to the central axis AX and the virtual plane IP. In addition, the virtual plane IP and the second virtual plane intersect perpendicularly.

[0063] In the present embodiment, the fourth wall surface 20B4 is realized as a conical surface having a conical protrusion lower in height than the boss surface 20T. Therefore, the fourth wall surface 20B4 has an arc cross section whose radius decreases as it goes upward in the direction of the central axis AX.

[0064] The connecting surface 20B5 is a surface that connects the fourth wall surface 20B4 and the first wall surface 20B1 by being provided behind the protrusion.

[0065] Here, the second wall surface 20B2 and the third wall surface 20B3 are mainly surfaces against which chips collide when cutting with a relatively small amount of cut-in (e.g., less than 0.2 mm), so they can function as chip breaker walls. The first wall surface 20B1 is mainly a surface that contacts at least a portion of the chips that collide with the second wall surface 20B2 or the third wall surface 20B3 when cutting with a relatively small amount of cut-in, so it can function as a chip breaker wall. However, the first wall surface 20B1 can also be configured not to contact the chips that collide with the second wall surface 20B2 or the third wall surface 20B3.

[0066] On the other hand, the combination of the second wall 20B2 and the fourth wall 20B4, or the third wall 20B3 and the fourth wall 20B4, is mainly the surface against which chips collide when cutting with a relatively large cutting amount (for example, more than 0.2 mm and less than 0.3 mm), so it can act as a chip breaker wall.

[0067] In addition, the curvature of the arc that appears when the fourth wall 20B4 is cut on a plane perpendicular to the center axis AX (or the curvature of the arc of the curve that approximately cuts the fourth wall 20B4 on a plane perpendicular to the center axis AX) can be greater than or less than the curvature of the arc of the approximate corner 20C1.

[0068] In addition, the second wall surface 20B2, the first wall surface 20B1, and the third wall surface 20B3 do not need to be smoothly connected, and may be connected to each other via different curved surfaces or flat surfaces.

[0069] like Figure 5As shown, in the cross section of the cutting blade 10 cut off by the virtual plane IP, the corner 20C1 forming the cutting edge is shown. In addition, the corner 20C1 can also be honed. In addition, in this cross-sectional view, a chip breaker bottom surface 20G arranged between the corner 20C1 and the fourth wall 20B4 is shown. In the present embodiment, the chip breaker bottom surface 20G is arranged roughly perpendicular to the center axis AX direction. However, the chip breaker bottom surface 20G can also be formed to be inclined downward to give a positive rake angle. Furthermore, in this cross-sectional view, the fourth wall 20B4 connected to the chip breaker bottom surface 20G, which moves upward the further away from the corner 20C1, and the connecting surface 20B5 connecting the fourth wall 20B4 and the first wall 20B1 are shown. In the present embodiment, the connecting surface 20B5 is arranged roughly perpendicular to the center axis AX direction in the cross-sectional view, and is arranged in an inclined manner to descend in a direction perpendicular to the cross section. The cross-sectional view shows a first wall 20B1 connected to the connection surface 20B5 and moving upward as it moves away from the corner 20C1, and a boss 20T connected to the first wall 20B1. The boss 20T is provided above the fourth wall 20B4, i.e., has a height greater than that of the fourth wall 20B4.

[0070] The side surface 20S functions as a flank face for the cutting edges formed at the corner 20C1, the straight portion 20C2, and the straight portion 20C3, respectively. The side surface 20S of the present embodiment is formed coplanar with the side surface 40S of the base insert 40. In addition, the surface of the side surface 20S facing the rear side is fixed on the base insert 40 by a known method.

[0071] The lower end face 20L is a face fixed to the base insert 40 in a known manner.

[0072] Next, an example of the cutting tool according to the present embodiment will be described.

[0073] Figure 6 This is an enlarged perspective view of a turning tool 100 as a cutting tool of the present embodiment. The turning tool 100 includes a cutting insert 10 to which a sintered cutting edge component 20 is mounted, a holder 50 for holding the cutting insert 10, and a pressing member 60 as an example of a holding component for holding the cutting insert 10 on the holder 50.

[0074] The present invention can be applied to turning tools for inner diameter processing, outer diameter processing, thread processing, and slotting. In addition, it can also be applied to milling tools such as milling cutters.

[0075] In addition, the holding member for holding the cutting blade on the tool holder can be applied to various known methods. The pressing member 60 of the present embodiment is a blade holder that uses the front end portion inserted into the through hole 10H to pull the cutting blade 10 into the handle holder 50, thereby holding the cutting blade 10 on the handle holder 50. However, other known methods can also be applied. For example, an internal thread can be formed in the tool holder, and a fastening screw can be used to hold the cutting blade on the tool holder.

[0076] Hereinafter, the operation when a workpiece as a cutting material is turned using the turning tool 100 of the present embodiment will be described.

[0077] First, a case where the cutting depth is small (for example, 0.2 mm or less) will be described.

[0078] The cutting insert 10 can be used in both hands. When the right-handed position is used, the third wall surface 20B3 arranged on the right side cooperates with the first wall surface 20B1 from the corner 10C1 or the corner 20C1 side to act on the chips. When the cutting insert 10 is used as a left-handed cutting tool, the second wall surface 20B2 arranged on the left side cooperates with the first wall surface 20B1 from the corner 10C1 side or the corner 20C1 side to act on the chips.

[0079] Here, the effect of the cutting insert 10 when used as a cutting tool for the right-handed position is described. The effect when used as a cutting tool for the left-handed position is the same, so the description is omitted. Usually, in the cutting process performed by the cutting tool with the cutting edge of the ultra-high pressure sintered body, especially in the lathe process or milling process, the cutting and feeding of the cutting conditions are set to be smaller. Therefore, the width of the generated chips narrows and the thickness becomes thinner, and it becomes extremely difficult to handle the chips. Especially when performing profiling on a lathe, the chips generated by the cutting edge of the corner 20C1 change greatly during the cutting process, and sometimes the direction of the chip outflow changes greatly. Therefore, it is easy to become very difficult to handle the chips.

[0080] In the cutting edge part 20 of the cutting insert 10 of the present embodiment, when chips are generated near the center of the corner 20C1, that is, when chips are generated near the bisector of the corner 20C1, that is, the virtual plane IP, the chips flow from the corner 20C1 to the first wall surface 20B1. At this time, the third wall surface 20B3 protrudes toward the corner 20C1 compared with the first wall surface 20B1, so at least a part of the flowing chips collides with the third wall surface 20B3. The third wall surface 20B3 is a curved surface bulging outward, and the first wall surface 20B1 curved in a concave manner toward the inside is arranged adjacent to it. Therefore, at least a part of the chips colliding with the third wall surface 20B3 is subjected to a force to bend upward by the rake face, that is, the bottom surface 20G of the chip breaker, and is also subjected to a force to bend laterally toward the first wall surface 20B1, that is, toward the virtual plane IP. That is, the chips that flow from the corner 20C1 to the first wall surface 20B1 also bend laterally when the chips collide with the third wall surface 20B3 at a position offset from the center. As a result, the chips are broken into finer pieces than when only the upward force is applied.

[0081] Here, the cutting blade part 20 of the present embodiment is in the end face viewing angle (looking down), and the contour shape of the boundary line of the upper end of the first wall 20B1 and the third wall 20B3, that is, the boundary line connecting the first wall 20B1 and the third wall 20B3 and the boss surface 20T is respectively roughly arc-shaped. Similarly, in the horizontal cross section perpendicular to the central axis AX direction, the contour shape of the first wall 20B1 and the third wall 20B3 is respectively roughly arc-shaped. Therefore, the wear (wear) caused by the collision of the chips can be suppressed.

[0082] In addition, the fourth wall 20B4 is Figure 4 The fourth wall 20B4 has a height smaller than the height of the second wall 20B2 and the third wall 20B3 in the side view. In addition, the fourth wall 20B4 is arranged so that the width in the horizontal direction becomes narrower as it moves upward. Therefore, at least a part of the chips can pass through the gap between the fourth wall 20B4 and the third wall 20B3.

[0083] Next, the case where the cutting depth is large (for example, 0.2 mm or more and 0.3 mm or less) is described. The inventors of the present application have focused on the fact that if the cutting depth is increased, more chips will flow out to the valley portion including the first wall surface 20B1 than to the mountain portion including the third wall surface 20B3, and as a result, there is a situation where the chips are twisted in the outflow direction and cannot be broken.

[0084] If the cutting depth is increased, the chips can be restrained by the fourth wall surface 20B4 provided at the position closest to the corner portion 20C1. Since at least a part of the chips is bent in a manner of adhering to the two convex surfaces of the fourth wall surface 20B4 and the third wall surface 20B3, two curved portions are formed on the chips in the shape of the Arabic numeral 3.

[0085] Among them, when cutting with a virtual plane perpendicular to the central axis AX direction, by setting these chip breaker walls in a manner that the second wall surface 20B2, the third wall surface 20B3 and the fourth wall surface 20B4 respectively include arcs, the chips can be appropriately bent. At least a part of the bent chips curls in a direction perpendicular to the outflow direction, collides with the end face of the workpiece or the back face of the cutting blade 10 and is broken.

[0086] As described above, according to the present invention, it is possible to provide a cutting insert and a cutting tool with improved chip disposability. In particular, it is possible to improve chip disposability under a wide range of cutting conditions.

[0087] In addition, the present invention can be variously modified without departing from its main purpose. For example, within the scope of the usual creative ability of those skilled in the art, a part of the components in a certain embodiment can be added to other known structures. In addition, a part of the components in a certain embodiment can be replaced by other known structures. For example, a finishing edge portion such as a wiper edge can also be provided on the cutting edge portion. In addition, the first wall surface 20B1, the second wall surface 20B2, the third wall surface 20B3 and the fourth wall surface 20B4 as the chip breaker wall surface only need to be provided in the area where the chips collide. For example, the first wall surface 20B1, the second wall surface 20B2 and the third wall surface 20B3 can also be formed on at least the upper part of the wall surface. At this time, the lower end of the wall surface can also be formed into other shapes within the range that does not affect the chip handling property.

Claims

1. A cutting tool comprising a cutting edge component, characterized in that: The cutting edge component comprises: A cutting edge formed at a corner of a connection portion connecting the end surface and the side surface; The first wall surface includes a concave surface which is arranged at a position through which a virtual plane determined by bisecting the corner portion passes and is formed by being recessed in a direction away from an intersection of the virtual plane and the corner portion from an end face perspective observed from a direction opposite to the end face; A second wall surface includes a convex surface which is connected to the first wall surface and is arranged at a position away from the virtual plane and protrudes in a direction opposite to the direction in which the concave surface is sunken in the end face viewing angle; A third wall surface includes a convex surface which is connected to the first wall surface at a position opposite to the second wall surface relative to the virtual plane and away from the virtual plane, and which protrudes in a direction opposite to the direction in which the concave surface is recessed in the end face viewing angle; and A fourth wall surface includes an area set between the first wall surface and the intersection point and an area through which the virtual plane passes when viewed from the end face, and a convex surface protruding in a direction opposite to the direction in which the concave surface is recessed when viewed from the end face, and, when viewed from the side face from a direction opposite to the side face, the fourth wall surface has a height that is smaller than the heights of the second wall surface and the third wall surface.

2. The cutting tool according to claim 1, wherein: A line that cuts the fourth wall surface on a second virtual plane perpendicular to the virtual plane is in the shape of a circular arc or an elliptical arc.

3. The cutting tool according to claim 1 or 2, wherein: The cross section of the cutting edge component cut on the virtual plane is shown as: The corner; a chip breaker bottom surface arranged between the corner and the fourth wall; the fourth wall connected to the chip breaker bottom surface and moving upward as it moves away from the corner; a connecting surface connected to the fourth wall; the first wall connected to the connecting surface and moving upward as it moves away from the corner; and a boss surface connected to the first wall and having a height greater than the height of the fourth wall.

4. The cutting tool according to claim 1 or 2, comprising a cutting insert, the cutting insert comprising the cutting edge component and a base insert on which the cutting edge component is mounted, A through hole having a central axis existing in the virtual plane is formed on the base insert.

5. The cutting tool according to claim 1 or 2, comprising a cutting insert, the cutting insert comprising the cutting edge component and a base insert on which the cutting edge component is mounted, The cutting blade is formed into a polygonal shape when viewed from the end face in a direction opposite to the end face. The corners are formed at the vertices of the polygon.

6. The cutting tool according to claim 1 or 2, further comprising a tool holder for holding the cutting edge component.

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