Cutting insert and cutting tool assembly including same

Abstract

The cutting insert includes an imaginary reference surface, an upper surface including an upper inclined surface extending at an angle upward from the imaginary reference surface, a lower surface including a lower inclined surface located below the upper surface and extending at an angle relative to the imaginary reference surface, and a plurality of side surfaces connecting the upper and lower surfaces. An insert bore is formed through the upper and lower surfaces along a central axis perpendicular to the imaginary reference surface. A major cutting edge is formed at an edge where the upper inclined surface meets one of the plurality of side surfaces. A first angle between the side surface on which the major cutting edge is formed and the upper inclined surface is greater than a second angle between the central axis and the lower inclined surface.

Description

[Technical field]

[0001] The present disclosure relates to a cutting insert for milling and a cutting tool assembly including the same. [Background technology]

[0002] A milling machine is a machine tool used to cut a workpiece that is linearly transferred through a table by rotating a milling cutter. Various types of milling cutters are mounted on the milling machine to perform various types of milling processes such as plane cutting, groove cutting, and shearing. The milling cutter includes a cutter body and a plurality of cutting inserts mounted on the cutter body. The cutting inserts are mounted on the cutter body so as to be spaced apart from each other in a circumferential direction centered on a rotation axis of the cutter body.

[0003] The cutter body has an appropriate mechanical strength to withstand the cutting resistance generated during cutting of the workpiece. For this purpose, the cutter body may have an appropriate diameter. The maximum number of cutting inserts that can be mounted on the cutter body may increase in proportion to the diameter of the cutter body. In a cutter body having the same diameter, the productivity increases as the number of cutting inserts mounted on the cutter body increases. That is, the number of cutting inserts mounted on the cutter body is directly proportional to the productivity. In particular, in the case of a cutter body having a very small diameter, the number of cutting inserts is extremely limited. For example, only one or two cutting inserts can be mounted on the cutter body. Therefore, if one or more cutting inserts are additionally mounted on the same cutter body having a very small diameter, the productivity may be greatly increased. Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional milling cutter, if the mechanical strength of the cutter body is satisfied, the number of cutting inserts mounted on the cutter body is reduced, which may result in low productivity. On the other hand, if a large number of cutting inserts are mounted on the cutter body in order to improve productivity, the mechanical strength of the cutter body may be weakened. In this way, it is difficult to satisfy both the mechanical strength of the cutter body and the improvement of productivity. [Means for solving the problem]

[0005] Various embodiments of the present disclosure provide a cutting insert and a cutting tool assembly including the same, which improves or overcomes at least some of the problems associated with conventional milling cutters.

[0006] An embodiment according to one aspect of the present disclosure relates to a cutting insert. The cutting insert according to the exemplary embodiment includes a virtual reference surface, an upper surface including an upper inclined surface extending from the virtual reference surface at an incline, a lower surface including a lower inclined surface located below the upper surface and extending at an incline relative to the virtual reference surface, and a plurality of side surfaces connecting the upper surface and the lower surface. An insert bore is formed so as to penetrate the upper surface and the lower surface along a central axis perpendicular to the virtual reference surface. A main cutting edge is formed on an edge where the upper inclined surface meets any one of the plurality of side surfaces. A first angle between the side surface on which the main cutting edge is formed and the upper inclined surface is greater than a second angle between the central axis and the lower inclined surface.

[0007] In one embodiment, the side surface may include a first beveled side surface having a first angle relative to the upper beveled surface and a second beveled side surface extending from the first beveled side surface having a third angle relative to the upper beveled surface, the third angle being different than the first angle.

[0008] In one embodiment, the first angle may be in the range greater than 65 degrees and less than 85 degrees.

[0009] In one embodiment, the second angle may be in the range of greater than 50 degrees and less than 65 degrees.

[0010] In one embodiment, the lower beveled surface may be parallel to the upper beveled surface.

[0011] In one embodiment, the lower slope may include a first lower slope and a second lower slope, the first lower slope and the second lower slope may have an included angle with respect to the central axis that is twice the second angle.

[0012] In one embodiment, the top surface and the side surfaces may be rotationally symmetrical by 180 degrees about the central axis.

[0013] In one embodiment, the side surface on which the main cutting edge is formed may have a recess formed toward the central axis.

[0014] In one embodiment, the multiple sides may include a first side on which the main cutting edge is formed, a second side opposite the first side, a third side connecting the first and second sides, and a fourth side connecting the first and second sides and opposite the third side.

[0015] In one embodiment, the major cutting edge may be formed between at least one of the first side and the second side and the upper beveled surface.

[0016] In one embodiment, each of the third and fourth sides may be disposed perpendicular to an imaginary reference plane.

[0017] An embodiment according to one aspect of the present disclosure relates to a cutting tool assembly. The cutting tool assembly according to an exemplary embodiment includes a cutter body having a plurality of insert pockets formed therein, a plurality of cutting inserts mounted in the plurality of insert pockets, and a plurality of clamping screws for fixing the plurality of cutting inserts to the cutter body. Each of the plurality of cutting inserts includes a virtual reference surface, an upper surface including an upper inclined surface extending upwardly from the virtual reference surface, a lower surface located below the upper surface and including a lower inclined surface extending inclined relative to the virtual reference surface, and a plurality of side surfaces connecting the upper surface and the lower surface.

[0018] An insert bore is formed through the upper and lower surfaces along a central axis that is perpendicular to the imaginary reference plane. A major cutting edge is formed at an edge where the upper beveled surface meets one of the side surfaces. A first angle between the side surface where the major cutting edge is formed and the upper beveled surface is greater than a second angle between the central axis and the lower beveled surface.

[0019] In one embodiment, the insert pocket may include a sloped wall that abuts a lower sloped surface on the lower surface.

[0020] In one embodiment, the lower slope may include a first lower slope and a second lower slope, the first lower slope and the second lower slope may have an included angle with respect to the central axis that is twice the second angle.

[0021] In one embodiment, the sloping wall may include a first sloping wall abutting the first lower sloping surface and a second sloping wall abutting the second lower sloping surface. Effect of the Invention

[0022] According to the cutting insert and cutting tool assembly according to one embodiment, the lower surface includes a lower inclined surface, and a first angle between a side surface on which the main cutting edge of the cutting insert is formed and the upper inclined surface is greater than a second angle between a first vertical plane including the central axis and the lower inclined surface. Therefore, in a cutter body having the same diameter, not only can the number of cutting inserts mounted in the cutter body be increased, but also the maximum core diameter of the cutter body can be ensured. As a result, not only can the productivity be improved, but also the mechanical strength of the cutter body can be satisfied. That is, the productivity can be improved and the mechanical strength of the cutter body can be satisfied at the same time. [Brief description of the drawings]

[0023] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the disclosure and, together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.

[0024] [Figure 1]FIG. 1 is a perspective view of a cutting insert according to one embodiment of the present disclosure.

[0025] [Diagram 2] FIG. 2 is a plan view showing the cutting insert shown in FIG.

[0026] [Diagram 3] FIG. 2 is a perspective view showing a bottom surface of the cutting insert shown in FIG. 1.

[0027] [Figure 4] FIG. 2 is a front view showing the cutting insert shown in FIG.

[0028] [Diagram 5] 3 is a cross-sectional view taken along line VV shown in FIG. 2.

[0029] [Figure 6] 3 is a cross-sectional view taken along line VI-VI shown in FIG. 2.

[0030] [Figure 7] FIG. 13 is a perspective view showing a cutting insert according to another embodiment of the present disclosure.

[0031] [Figure 8] 8 is a partial cross-sectional view taken along line VIII-VIII shown in FIG. 7.

[0032] [Figure 9] FIG. 1 is a perspective view of a cutting tool assembly according to one embodiment of the present disclosure.

[0033] [Figure 10] FIG. 10 is a partial enlarged view of the cutting tool assembly shown in FIG.

[0034] [Figure 11] FIG. 10 is a bottom view of the cutting tool assembly shown in FIG.

[0035] [Figure 12] FIG. 2 is a schematic bottom view illustrating a cutting insert according to an embodiment of the present disclosure.

[0036] [Figure 13] FIG. 11 is a schematic bottom view showing a cutting insert according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The embodiments of the present disclosure are illustrated for the purpose of explaining the technical idea of ​​the present disclosure, and the scope of the rights of the present disclosure is not limited to the embodiments presented below or the specific descriptions of these embodiments.

[0038] All technical and scientific terms used in this disclosure have the meanings commonly understood by those of ordinary skill in the art to which this disclosure belongs, unless otherwise defined. All terms in this disclosure are selected for the purpose of more clearly describing this disclosure, and are not selected to limit the scope of the rights of this disclosure.

[0039] As used in this disclosure, terms such as "including," "comprising," and "having" should be understood as open-ended terms that include the possibility of including other embodiments, unless otherwise stated in the phrase or sentence in which the term appears.

[0040] The singular terms described in this disclosure may include plural meanings unless otherwise specified, and this also applies to the singular terms described in the claims.

[0041] The terms "first", "second", etc. used in this disclosure are used to distinguish multiple elements from one another and do not limit the order or importance of the elements.

[0042] In this disclosure, "radial (RD)" may be defined to mean a direction away from or toward the rotational axis (RA) of a cutter body of a cutting tool assembly, and "circumferential (CD)" may be defined to mean a direction around the rotational axis (RA).

[0043] Directional terms such as "upper", "above", etc., used in this disclosure refer to the orientation in which the upper surface lies relative to the lower surface in the accompanying drawings. Directional terms such as "lower", "below", etc., refer to the opposite direction of "upper" or "up". The cutting inserts shown in the accompanying drawings may be oriented differently, and the directional terms may be interpreted accordingly.

[0044] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, identical or corresponding components are given the same reference numerals. In addition, in the following description of the embodiments, duplicated description of identical or corresponding components may be omitted. However, even if a description of a component is omitted, it is not intended that such a component is not included in a certain embodiment.

[0045] FIG. 1 is a perspective view showing a cutting insert according to one embodiment of the present disclosure.

[0046] As shown in FIG. 1, the cutting insert (100) according to an embodiment of the present disclosure includes an upper surface (110), a lower surface (120), and a number of side surfaces (130). The upper surface (110), the lower surface (120), and the number of side surfaces (130) are distinguished for the sake of convenience of explanation, but these terms do not define absolute components of the cutting insert according to an embodiment. The cutting insert (100) may be manufactured using a hard metal having high hardness formed by sintering metal carbide powder. For example, the cutting insert (100) may be made of a sintered alloy of tungsten carbide and cobalt having high wear resistance.

[0047] FIG. 2 is a plan view showing the cutting insert shown in FIG.

[0048] As shown in FIG. 2, the upper surface (110) has a substantially rectangular planar shape. The upper surface (110) includes a virtual reference surface (111) and an upper inclined surface (112). The upper inclined surface (112) extends from the virtual reference surface (111) so as to be inclined upward. The virtual reference surface (111) is disposed at the center of the upper surface (110). In one embodiment, the virtual reference surface (111) may include a flat surface, and in another embodiment, may be a slightly curved surface. For example, the upper inclined surfaces (112) may be disposed to face each other at both ends of the virtual reference surface (111). In one embodiment, a concave surface (113) may be formed between the virtual reference surface (111) and the upper inclined surface (112) along the approximate longitudinal direction of the upper inclined surface (112). The concave surface (113) is formed so as to be recessed toward the lower surface (120) from the virtual reference surface (111). Chips generated during cutting of the workpiece can be smoothly discharged along the concave surface (113).

[0049] FIG. 3 is a perspective view showing a bottom surface of the cutting insert shown in FIG.

[0050] 3, the lower surface (120) is located below the upper surface (110). The lower surface (120) is arranged to abut against a portion of the cutter body (200) (e.g., the inclined wall of an insert pocket). Therefore, when the cutter body (200) rotates, the lower surface (120) is supported by the cutter body (200). The lower surface (120) includes a lower inclined surface (121) that extends inclined relative to the imaginary reference surface (111).

[0051] FIG. 4 is a front view showing the cutting insert shown in FIG.

[0052] 4, the plurality of side surfaces 130 connect the upper surface 110 and the lower surface 120. Since the upper surface 110 has a planar shape such as a substantially rectangular shape, the plurality of side surfaces 130 may include four side surfaces. For example, the plurality of side surfaces 130 may include side surfaces arranged perpendicular to a virtual reference plane 111 of the upper surface 110 and side surfaces arranged at an angle to the virtual reference plane 111.

[0053] The cutting insert (100) is formed with an insert bore (140) penetrating the upper surface (110) and the lower surface (120) along a central axis (CA) perpendicular to the imaginary reference plane (111). For example, the central axis (CA) of the insert bore (140) may be defined as a straight line passing through the center of gravity of the upper surface (110) and the center of gravity of the lower surface (120). The insert bore (140) is formed in the center of the upper surface (110) (i.e., the center of the imaginary reference plane (111)). As shown in Figures 2, 5, and 6, the central axis (CA) may be included in a first vertical plane (P1) passing through the upper surface (110), the lower surface (120), and the two side surfaces (130).

[0054] The cutting insert (100) has a main cutting edge (150) formed at an edge where the upper inclined surface (112) meets one of the side surfaces (130). As the cutter body (200) rotates, the workpiece is cut by the main cutting edge (150). The main cutting edge (150) is disposed so as to protrude radially outward from the outer cylindrical surface of the cutter body (200). The shape of the main cutting edge (150) may be determined according to the shape of the workpiece to be machined. For example, the main cutting edge (150) may be formed continuously or intermittently along the edge where the upper inclined surface (112) meets the side surface (130).

[0055] In one embodiment, the side surface (130) (e.g., the first side surface (131)) on which the main cutting edge (150) is formed may include a first cutting portion (151) and a second cutting portion (152) spaced apart from the first cutting portion (151) along the longitudinal direction of the main cutting edge (150). The main cutting edge (150) may include a first main cutting edge (151a) formed in the first cutting portion (151) and a second main cutting edge (152a) formed in the second cutting portion (152). The shape of the first cutting portion (151) may be the same as or different from the shape of the second cutting portion (152). The first cutting portion (151) and the second cutting portion (152) may be variously modified according to the final processed shape of the workpiece. The first cutting portion (151) and the second cutting portion (152) are formed with upper inclined surfaces (112) inclined at the same angle with respect to the virtual reference plane (111). In the following description, the term "main cutting edge (150)" simply used without the term "second main cutting edge (152a)" may be understood to refer to the first main cutting edge (151a).

[0056] FIG. 5 is a cross-sectional view taken along line VV shown in FIG.

[0057] As shown in FIG. 5, the first angle (α) between the side surface (130) on which the main cutting edge (150) is formed and the upper inclined surface (112) is greater than the second angle (β) between the central axis (CA) and the lower inclined surface (121). Here, the first angle (α) is the angle between the side surface (130) and the upper inclined surface (112) in the first cutting portion (151). Since the first angle (α) is greater than the second angle (β), when the cutting insert (100) is mounted in the cutter body (200), the cutter body (200) may have a maximum core diameter, which will be described later. Since the first angle (α) is greater than the second angle (β), the number of cutting inserts (100) mounted in the cutter body (200) may also increase (e.g., the maximum number of cutting inserts (100) may be mounted). That is, the improvement of productivity and the satisfaction of the mechanical strength of the cutter body may be simultaneously satisfied. Additionally, the strength of the major cutting edge (150) when the first angle (α) is greater than the second angle (β) is greater than the strength of the major cutting edge (150) when the first angle (α) is equal to or less than the second angle (β), and therefore the strength of the cutting insert (100) may also be improved.

[0058] In one embodiment, the side surface (130) may include a first side beveled surface (130a) and a second side beveled surface (130b). The first side beveled surface (130a) has a first angle (α) with respect to the upper beveled surface (112). The second side beveled surface (130b) extends from the first side beveled surface (130a) and has a third angle (γ) with respect to the upper beveled surface (112). The third angle (γ) is different from the first angle (α). In one embodiment, the second side beveled surface (130b) may be perpendicular to the imaginary reference plane (111) or parallel to the central axis (CA) of the insert bore (140). The first angle (α) between the upper beveled surface (112) and the first side beveled surface (130a) is greater than the third angle (γ) between the upper beveled surface (112) and the second side beveled surface (130b). The third angle (γ) may be understood as the diagonal of the second angle (β) of the lower inclined surface (121). When the upper inclined surface (112) is configured to directly meet the second side inclined surface (130b), the main cutting edge formed on the side between the upper inclined surface (112) and the second side inclined surface (130b) becomes sharp. The strength of the main cutting edge (150) formed on the side between the upper inclined surface (112) and the first side inclined surface (130a) can be increased by the difference between the first angle (α) and the third angle (γ). That is, the strength of the main cutting edge (150) can be reinforced by the upper inclined surface (112) having the first angle (α) with respect to the first side inclined surface (130a).

[0059] In one embodiment, the first angle (α) may be in the range of more than 65 degrees and less than 85 degrees. If the first angle (α) is less than 65 degrees, the rake angle of the major cutting edge (150) may be large, thus weakening the strength of the major cutting edge (150) and reducing the durability of the cutting insert (100). If the first angle (α) is more than 85 degrees, the rake angle of the major cutting edge (150) may be small, thus increasing the cutting force applied to the cutting insert (100).

[0060] In one embodiment, the second angle (β) may be in the range of more than 50 degrees and less than 65 degrees. If the second angle (β) is less than 50 degrees, the rake angle of the main cutting edge (150) may be large. Therefore, the strength of the main cutting edge (150) may be weakened, and the durability of the cutting insert (100) may be reduced. If the second angle (β) is more than 65 degrees, the rake angle of the main cutting edge (150) may be small. Therefore, the cutting resistance applied to the cutting insert (100) may increase. In addition, since the lower inclined surface (121) becomes gentle, the number of cutting inserts (100) that can be installed in a cutter body (200) having the same diameter may be reduced.

[0061] In one embodiment, the lower inclined surface 121 may be parallel to the upper inclined surface 112. When the lower inclined surface 121 is parallel to the upper inclined surface 112, a component of the cutting force acting on the main cutting edge 150 that is perpendicular to the upper inclined surface 112 can be stably supported by the inclined wall 231 (see FIG. 10) of the cutter body 200 that abuts against the lower inclined surface 121.

[0062] FIG. 6 is a cross-sectional view taken along the line VI-VI shown in FIG.

[0063] As shown in Fig. 6, a fourth angle (δ) is formed between the side surface (130) and the upper inclined surface (112), and a fifth angle (ε) is formed between the lower inclined surface (121) and a first vertical plane (P1) including the central axis (CA). Here, the fourth angle (δ) is the angle between the side surface (130) and the upper inclined surface (112) in the second cutting portion (152). The size relationship between the first angle (α) and the second angle (β), the optimum range of the first angle (α), and the optimum range of the second angle (β) shown in Fig. 5 may be applied in the same or similar manner to the size relationship between the fourth angle (δ) and the fifth angle (ε), the optimum range of the fourth angle (δ), and the optimum range of the fifth angle (ε) shown in Fig. 6. The side surface (130) (see FIG. 6) of the second cutting portion (152) differs from the side surface (130) (see FIG. 5) of the first cutting portion (151) in that it extends at an angle from the upper inclined surface (112) to the lower inclined surface (121) without including a second side inclined surface.

[0064] In one embodiment, the lower inclined surface (121) may include a first lower inclined surface (121a) and a second lower inclined surface (121b). The first lower inclined surface (121a) and the second lower inclined surface (121b) may have an included angle of twice the second angle (β) with respect to the central axis (CA). The first lower inclined surface (121a) and the second lower inclined surface (121b) have a substantially V-shaped cross-sectional shape or a side shape. As shown in FIG. 5 and FIG. 6, the second angle (β) may be formed between the first lower inclined surface (121a) and the central axis (CA), and the second angle (β) may also be formed between the second lower inclined surface (121b) and the central axis (CA). For example, the first lower inclined surface (121a) and the second lower inclined surface (121b) are rotationally symmetrical by 180 degrees with respect to the central axis (CA). 5 and 6, the first lower inclined surface (121a) and the second lower inclined surface (121b) are mirror-symmetrical with respect to the central axis (CA). Therefore, when the cutting insert (100) is first mounted to the cutter body (200), the cutting insert (100) can be quickly mounted regardless of the direction of the cutting insert (100). In addition, since the first lower inclined surface (121a) and the second lower inclined surface (121b) are arranged to have the same angle with respect to the central axis (CA), it is possible to effectively suppress or prevent the cutting insert (100) from moving in the inner radial direction or the outer radial direction when the workpiece is cut.

[0065] In one embodiment, the top surface (110) and the side surfaces (130) may be 180 degrees rotationally symmetrical about the central axis (CA). When the top surface (110) and the side surfaces (130) are 180 degrees rotationally symmetrical about the central axis (CA), two first cutting portions (151) and two second cutting portions (152) are formed in one cutting insert (100). Therefore, when one first cutting portion (151) and one second cutting portion (152) are worn, the remaining first cutting portion (151) and the remaining second cutting portion (152) can be used for cutting. Therefore, the cost required for cutting the workpiece can be reduced.

[0066] In one embodiment, the side surfaces (130) may include a first side surface (131) on which the main cutting edge is formed, a second side surface (132) facing the first side surface (131), a third side surface (133) connecting the first side surface (131) and the second side surface (132), and a fourth side surface (134) connecting the first side surface (131) and the second side surface (132) and facing the third side surface (133). The second side surface (132) is rotationally symmetrical with respect to the first side surface (131) by 180 degrees about the central axis (CA). Therefore, detailed description of the upper inclined surface and the main cutting edge formed on the second side surface (132) will be omitted. The third side surface (133) is shown in FIG. 4 and has an external shape similar to the cross-sectional view shown in FIG. 5. Also, the fourth side surface (134) is rotationally symmetrical with respect to the third side surface (133) by 180 degrees about the central axis (CA).

[0067] The first and second opposing sides (131, 132) are "cutting sides" because their respective major cutting edges are formed at their intersections with the upper beveled surface (112). The third and fourth opposing sides (133, 134) are "non-cutting sides" because their respective major cutting edges are not formed at their intersections with the top surface (110).

[0068] As shown in Figures 2, 5, and 6, a first vertical plane (P1) passes through the upper and lower surfaces (110, 120) and is perpendicular to the third and fourth non-cutting sides (133, 134). As shown in Figures 4-6, the lower surface (120) of the insert is V-shaped for most, if not substantially all, of the insert depth, i.e., in a direction generally parallel to the cutting sides (131, 132).

[0069] In one embodiment, the main cutting edge (150) may be formed between at least one of the first side surface (131) and the second side surface (132) and the upper inclined surface (112). That is, the main cutting edge (150) may be formed between the upper inclined surface (112) and the first side surface (131), or between the upper inclined surface (112) and the second side surface (132). Also, the main cutting edge (150) may be formed between the upper inclined surface (112) and the first side surface (131) and between the upper inclined surface (112) and the second side surface (132).

[0070] In one embodiment, each of the third side (133) and the fourth side (134) may be disposed perpendicular to the imaginary reference plane (111). Thus, the cutting insert (100) may be mounted to the cutter body (200) such that the third side (133) or the fourth side (134) is flush with the bottom surface (210) of the cutter body (200).

[0071] In one embodiment, the side surface 130 on which the main cutting edge 150 is formed may have a recess 135 formed toward the central axis CA. That is, the recess 135 may be formed on at least one of the first side surface 131 and the second side surface 132. For example, the recess 135 may be located between the first cutting portion 151 and the second cutting portion 152. The recess 135 may have various planar shapes such as various polygonal shapes, semi-elliptical shapes, semi-circular shapes, etc., depending on the final machined shape of the workpiece. Thus, the recess 135 may have one or more recess cutting edges 160 configured to mill a protrusion having a predetermined shape into the workpiece. In a similar manner, the first and second main cutting edges 152a, 152b may have different shapes to mill different surface contours formed on each side of the protrusion. It can be appreciated that the protrusions and the surface contour may be machined simultaneously in one milling operation.

[0072] Fig. 7 is a perspective view showing a cutting insert according to another embodiment of the present disclosure, Fig. 8 is a partial cross-sectional view taken along line VIII-VIII shown in Fig. 7.

[0073] As shown in Figures 7 and 8, the cutting insert (100a) according to another embodiment of the present disclosure may not include a recess formed in the side surface (130) on which the main cutting edge (150) is formed. That is, no recess is formed in the first side surface (131) and the second side surface (132). For example, the first cutting portion (151) is directly connected to the second cutting portion (152) without a recess. In this embodiment, the size relationship between the first angle (α) and the second angle (β), the optimum range of the first angle (α), and the optimum range of the second angle (β) shown in Figure 5 may be applied the same or similarly to the cutting insert (100a) shown in Figure 8.

[0074] FIG. 9 is a perspective view of a cutting tool assembly according to one embodiment of the present disclosure.

[0075] As shown in Fig. 9, a cutting tool assembly (500) according to one embodiment of the present disclosure includes a cutter body (200), a plurality of cutting inserts (100), and a plurality of clamping screws (300). Each of the plurality of cutting inserts (100) according to this embodiment may be configured the same as or similar to the cutting insert (100) shown in Figs. 1 to 6, so detailed description of each of the plurality of cutting inserts (100) will be omitted. Therefore, the following description will focus on the cutter body (200) and the plurality of clamping screws (300).

[0076] FIG. 10 is a partially enlarged view of the cutting tool assembly shown in FIG. 9, showing one cutting insert and one clamping screw in an exploded state.

[0077] As shown in FIG. 10, the cutter body (200) may include a bottom surface (210) and a cylindrical portion (220). The bottom surface (210) is disposed generally parallel to the rotation axis (RA) of the cutter body (200). The cylindrical portion (220) extends vertically from the bottom surface (210). A rotary drive unit of the cutting tool is disposed on the opposite side of the bottom surface (210) along the rotation axis (RA) of the cutter body (200). The rotary drive unit may be directly connected to the cutter body (200) or indirectly connected through another member. A plurality of insert pockets (230) are formed in the cutter body (200). Each of the plurality of insert pockets (230) is formed by being recessed from the bottom surface (210) to the cylindrical portion (220).

[0078] As described in detail through the embodiment shown in Figures 1 to 6, each of the cutting inserts (100) may include an upper surface (110), a lower surface (120), and a plurality of side surfaces (130). Each of the cutting inserts (100) is formed with an insert bore (140) and a main cutting edge (150). The cutting inserts (100) are mounted in the cutter body (200) such that one side surface (e.g., the third side surface (133) or the fourth side surface (134)) is flush with the bottom surface (210) of the cutter body (200).

[0079] The clamping screw (300) fixes each of the cutting inserts (100) to the cutter body (200). A screw hole (232) is formed in the insert pocket (230) for threaded engagement with the clamping screw (300). The central axis of the screw hole (232) coincides with the central axis (CA) of the insert bore (140) and the rotation axis of the clamping screw (300). After the cutting insert (100) is placed in the insert pocket (230), the clamping screw (300) is threadedly engaged with the cutter body (200) through the insert bore (140) of the cutting insert (100). The clamping screw (300) is disposed perpendicular to the imaginary reference plane (111) of the cutting insert (100).

[0080] FIG. 11 is a bottom view of the cutting tool assembly shown in FIG.

[0081] As shown in FIG. 11, in one embodiment, the insert pocket (230) may include an inclined wall (231) that abuts against the lower inclined surface (121) of the lower surface (120). In one embodiment, the lower inclined surface (121) may include a first lower inclined surface (121a) and a second lower inclined surface (121b). The first lower inclined surface (121a) and the second lower inclined surface (121b) may have an included angle of twice the second angle (β) with respect to the central axis (CA). In this embodiment, the inclined wall (231) may include a first inclined wall (231a) that abuts against the first lower inclined surface (121a) and a second inclined wall (231b) that abuts against the second lower inclined surface (121b). The first inclined wall (231a) and the second inclined wall (231b) forming the V-shaped recess engage with the first lower inclined surface (121a) and the second lower inclined surface (121b) forming the V-shaped protrusion. The mutual engagement of the V-shaped recess and protrusion allows the cutting insert (100) to be stably supported by the insert pocket (230) of the cutter body (200). As a result, even if cutting resistance acts on the cutting insert (100) due to cutting of the workpiece, the cutting insert (100) can be effectively suppressed or prevented from moving in the outer radial direction or the inner radial direction with respect to the rotation axis (RA).

[0082] Fig. 12 is a schematic bottom view showing a cutting insert according to an embodiment of the present disclosure. Fig. 13 is a schematic bottom view showing a cutting insert according to a comparative example. In Fig. 12 and Fig. 13, for clarity of illustration, detailed configurations are omitted, and the cutting insert according to the embodiment and the cutting insert according to the comparative example are shown by frame lines.

[0083] FIG. 12 shows an example in which a cutting insert (100) according to an embodiment of the present disclosure is attached to a cutter body (200) having a diameter (D) through a clamping screw (300). FIG. 13 shows an example in which a cutting insert (10) according to a comparative example is disposed in a cutter body (400) having the same diameter (D) as the diameter (D) of the cutter body (200) through a clamping screw (300). As shown in FIG. 12, the lower surface (120) of the cutting insert (100) according to the embodiment includes a lower inclined surface (121). As shown in FIG. 13, the lower surface (12) of the cutting insert (10) according to the comparative example does not include an inclined surface. In the cutting insert (100) according to the embodiment, the radius (R1) from the rotation axis (RA) to the main cutting edge (151a) is the same as the radius (R2) from the rotation axis (RA) to the main cutting edge (11) in the cutting insert (10) according to the comparative example. As shown in Fig. 13, when the lower surface (12) of the cutting insert (10) does not include an inclined surface, the cutting insert (10) is coupled to the cutter body (200) so as to be close to the rotation axis (RA). Therefore, the core diameter (D1) according to the embodiment is larger than the core diameter (D2) according to the comparative example. Here, the core diameter means the central region of the cutter body that does not overlap with the cutting insert at the bottom surface of the cutting tool assembly when the cutting insert is attached to the cutter body. For cutter bodies having the same diameter, the larger the core diameter, the greater the strength of the cutter body for stably supporting the cutting insert. As a result, the mechanical strength of the cutter body according to the embodiment is higher than the mechanical strength of the cutter body according to the comparative example.

[0084] 13, in order to avoid interference between one cutting insert and another adjacent cutting insert and to satisfy the minimum strength required to support the cutting inserts 10, the number of cutting inserts 10 mounted on the cutter body must be limited. Therefore, the maximum number of cutting inserts 100 mounted on the cutter body 200 according to the embodiment is greater than the maximum number of cutting inserts 10 mounted on the cutter body 200 according to the comparative example. Therefore, according to the embodiment of the present disclosure, productivity can be improved.

[0085] Although the technical idea of ​​the present disclosure has been described above by way of some embodiments and examples shown in the accompanying drawings, it should be understood that various modifications and changes can be made without departing from the technical idea and scope of the present disclosure that can be understood by those having ordinary skill in the art to which the present disclosure pertains. Furthermore, such modifications and changes should be considered to fall within the scope of the appended claims.

Claims

1. a virtual reference surface; and an upper surface including an upper inclined surface extending upward from the virtual reference surface; a lower surface including a lower inclined surface located below the upper surface and extending so as to be inclined with respect to the virtual reference plane; A plurality of side surfaces connecting the upper surface and the lower surface; Including, an insert bore is formed through the upper surface and the lower surface along a central axis perpendicular to the imaginary reference plane; A main cutting edge is formed at an edge where the upper inclined surface meets any one of the side surfaces, a first angle between the side surface on which the main cutting edge is formed and the upper inclined surface is greater than a second angle between the central axis and the lower inclined surface, the second angle being in the range of greater than 50 degrees and less than 65 degrees.

2. A virtual reference surface; and an upper surface including an upper inclined surface extending upward from the virtual reference surface; a lower surface including a lower inclined surface located below the upper surface and extending so as to be inclined with respect to the virtual reference plane; A plurality of side surfaces connecting the upper surface and the lower surface; Including, an insert bore is formed through the upper surface and the lower surface along a central axis perpendicular to the imaginary reference plane; A main cutting edge is formed at an edge where the upper inclined surface meets any one of the side surfaces, a first angle between the side surface on which the major cutting edge is formed and the upper inclined surface is greater than a second angle between the central axis and the lower inclined surface, and the lower inclined surface is parallel to the upper inclined surface.

3. An upper inclined surface extending upward from a virtual reference surface. Face and a lower surface including a lower inclined surface located below the upper surface and extending so as to be inclined with respect to the virtual reference plane; A plurality of side surfaces connecting the upper surface and the lower surface; Including, an insert bore is formed through the upper surface and the lower surface along a central axis perpendicular to the imaginary reference plane; A main cutting edge is formed at an edge where the upper inclined surface meets any one of the side surfaces, a first angle between the side surface on which the main cutting edge is formed and the upper inclined surface is greater than a second angle between the central axis and the lower inclined surface; The plurality of side surfaces include a first side surface on which the main cutting edge is formed, a second side surface facing the first side surface, a third side surface connecting the first side surface and the second side surface, and a fourth side surface connecting the first side surface and the second side surface and facing the third side surface, Each of the third side surface and the fourth side surface is disposed perpendicular to the imaginary reference plane.

4. The aspect is a first side sloped surface having the first angle relative to the top sloped surface; a second sloping side surface extending from the first sloping side surface and having a third angle with respect to the upper sloping surface; The cutting insert of claim 1 , wherein the third angle is different from the first angle.

5. The cutting insert according to claim 1 , wherein the first angle is in the range of greater than 65 degrees and less than 85 degrees.

6. the lower inclined surface includes a first lower inclined surface and a second lower inclined surface, The cutting insert according to claim 1 , wherein the first and second lower angled surfaces form an included angle with respect to the central axis that is twice the second angle.

7. The cutting insert according to claim 1 , wherein the top surface and the plurality of side surfaces are rotationally symmetrical by 180 degrees about the central axis.

8. The cutting insert according to claim 1 , wherein a recess is formed in the side surface on which the main cutting edge is formed, the recess being directed toward the central axis.

9. The aspects include: a first side on which the major cutting edge is formed; a second side surface opposite the first side surface; a third side surface connecting the first side surface and the second side surface; The cutting insert according to claim 1 , further comprising: a fourth side surface connecting the first side surface and the second side surface and facing the third side surface.

10. The cutting insert according to claim 9 , wherein the major cutting edge is formed between at least one of the first side surface and the second side surface and the upper beveled surface.

11. a cutter body in which a plurality of insert pockets are formed; A plurality of cutting inserts mounted in the plurality of insert pockets; a plurality of clamping screws for fixing the plurality of cutting inserts to the cutter body; Including, Each of the plurality of cutting inserts comprises: a virtual reference surface; and an upper surface including an upper inclined surface extending upward from the virtual reference surface; a lower surface including a lower inclined surface located below the upper surface and extending so as to be inclined with respect to the virtual reference plane; A plurality of side surfaces connecting the upper surface and the lower surface; Including, an insert bore is formed through the upper surface and the lower surface along a central axis perpendicular to the imaginary reference plane; A main cutting edge is formed at an edge where the upper inclined surface meets any one of the side surfaces, a first angle between the side on which the major cutting edge is formed and the upper beveled surface is greater than a second angle between the central axis and the lower beveled surface, the second angle being in the range of greater than 50 degrees and less than 65 degrees.

12. A cutter body in which a plurality of insert pockets are formed; A plurality of cutting inserts mounted in the plurality of insert pockets; a plurality of clamping screws for fixing the plurality of cutting inserts to the cutter body; Including, Each of the plurality of cutting inserts comprises: a virtual reference surface; and an upper surface including an upper inclined surface extending upward from the virtual reference surface; a lower surface including a lower inclined surface located below the upper surface and extending so as to be inclined with respect to the virtual reference plane; A plurality of side surfaces connecting the upper surface and the lower surface; Including, an insert bore is formed through the upper surface and the lower surface along a central axis perpendicular to the imaginary reference plane; A main cutting edge is formed at an edge where the upper inclined surface meets any one of the side surfaces, a first angle between the side on which the major cutting edge is formed and the upper beveled surface is greater than a second angle between the central axis and the lower beveled surface, the lower beveled surface being parallel to the upper beveled surface.

13. The cutting tool assembly of claim 11 , wherein the insert pocket includes an angled wall abutting the lower angled surface of the lower surface.

14. the lower inclined surface includes a first lower inclined surface and a second lower inclined surface, 14. The cutting tool assembly of claim 13, wherein the first lower angled surface and the second lower angled surface define an included angle with respect to the central axis that is twice the second angle.

15. The inclined wall is a first inclined wall against which the first lower inclined surface abuts; a second angled wall abutting the second lower angled surface.

16. a top surface including a virtual reference surface and first and second upper inclined surfaces extending upward from both ends of the virtual reference surface; a V-shaped lower surface disposed below the upper surface and including first and second lower inclined surfaces extending upwardly and outwardly in opposite directions; a plurality of side surfaces connecting the upper surface and the lower surface, the side surfaces including first and second opposed cut side surfaces and third and fourth opposed non-cut side surfaces; an insert bore extending through the upper surface and the lower surface along a central axis perpendicular to the imaginary reference plane; a first vertical plane including the central axis, passing through the upper surface and the lower surface, and perpendicular to the opposing third and fourth non-cutting side surfaces; a main cutting edge formed at an edge where the upper inclined surface meets the first cutting side surface; Including, a first angle between the first cutting side and the first upper beveled surface is greater than a second angle between the first vertical surface and the first lower beveled surface, the first angle being in a range from greater than 65 degrees to less than 85 degrees, and the second angle being in a range from greater than 50 degrees to less than 65 degrees.

17. The cutting insert according to claim 16, wherein the cutting insert is rotationally symmetrical by 180 degrees about the central axis.

18. A recess is formed on a side surface of the first cut toward the central axis, The cutting insert of claim 16 , wherein the recess divides the major cutting edge into a first major cutting edge and a second major cutting edge that are spaced apart from one another.

19. the recess includes one or more recess cutting edges configured to cut a protrusion having a predetermined shape into a workpiece; 20. The cutting insert of claim 18, wherein the first and second spaced apart major cutting edges are differently shaped on either side of the recess and configured to simultaneously machine a differently shaped surface profile in the workpiece on either side of the protrusion.

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