Rotary asymmetric cutting insert and rotary cutting tool having a single radially extended cutting edge

Abstract

A cutting insert (20) rotating around an axis (AI) has opposing front and rear surfaces (22, 24) interconnected by an insert peripheral surface (26), and the insert peripheral surface (26) has first and second side surfaces (28, 30) separated by first and second land surfaces (32, 34). The first and second land edges (36, 38) extend along the first and second land surfaces, respectively. A first front edge (46) formed at the intersection of the front surface and the first side surface includes a cutting edge portion (48), and a second front edge (52) formed at the intersection of the front surface and the second side surface does not have a cutting edge portion. A cutting profile (PC) formed by the rotation of the cutting edge portion around the axis is located axially forward of the second front edge. The cutting insert (20) is releasedly secured by the tool shank (66), and the cutting insert is positioned between two protrusions (68, 70) protruding from the front end portion of the tool shank.

Description

Technology Field

[0001] The present invention relates to a cutting insert rotatable about an insert axis having a single radially extended cutting edge portion for general use in metal cutting processes, particularly for drilling operations, and a rotary cutting tool having such a cutting insert. Background Technology

[0002] In the field of cutting tools used in drilling operations, there are many examples of rotary cutting tools having a cutting head, plate, or tip with a single radially extended cutting edge, some of which are brazed or welded to the shank, and some of which are removable and replaceable.

[0003] US 7,195,428 discloses a cutting tip bounded by a virtual cylinder corresponding to the size of the hole being drilled, and the cutting tip generally has a V-shaped tip flute extending along its entire length. The cutting tip is secured to the end of the shank by brazing or welding in a conventional manner so that the tip flute generally aligns with the shank flute. A pair of raised, narrow, axially elongated wear pads extend longitudinally spaced around the periphery of the cutting tip and are slightly raised relative to the adjacent cylindrical surface of the cutting tip.

[0004] US 7,296,953 discloses a deep hole drill comprising a cutter carrier, a replaceable cutting insert, and at least one replaceable guide strip. The cutter carrier, in the form of a drill head, has a recess having its rear surface and two side surfaces, which forms a seat for a replaceable cutting plate. A central screw hole in the rear surface receives a screw guided through a through hole in the replaceable cutting plate. At an axial height of the replaceable cutting plate seat, a recess for guide strips is provided on the circumference of the drill, each guide strip contacts a stop surface of each recess, and each stop surface has a central screw hole for screwing each guide strip.

[0005] US 7,393,162 discloses a gun drill comprising a cutting head having a common longitudinal axis and a mating peripheral surface that is detachably fixed to a shank. A shank coupling portion comprising a forward tapered shank fixing surface is formed at the front end of the shank, and a cutting head coupling portion comprising a forward tapered cutting head fixing surface is formed at the rear end of the cutting head. Both the shank and the cutting head coupling portion extend over a coupling angle with the peripheral portion exceeding 180 degrees. The shank and the cutting head are assembled by positioning the cutting head front end face in front of the shank rear end face, slidingly inserting the cutting head coupling portion into the shank coupling portion laterally with respect to the axis of rotation, and rotating the cutting head relative to the shank in a direction opposite to the direction of rotation so that the cutting head coupling portion and the shank coupling portion are mutually fixed coaxially.

[0006] The object of the present invention is to provide an improved cutting insert rotatable about an insert axis having a single radially extended cutting edge.

[0007] In addition, the object of the present invention is to provide an improved cutting insert for drilling operations in which radial support within the workpiece is integrally provided.

[0008] Another objective of the present invention is to provide an improved rotary cutting tool in which a cutting insert is releasedly secured to the tool shank. means of solving the problem

[0009] According to the present invention, a rotationally asymmetric cutting insert rotatable in a cutting rotation direction about an insert axis is provided, wherein the insert axis defines the front-rear direction of the insert, and the cutting insert is,

[0010] Opposing front and rear surfaces interconnected by an insert main surface, wherein the insert main surface has first and second side surfaces spaced apart by first and second land surfaces, opposing front and rear surfaces,

[0011] A first land edge extending from the front surface to the rear along the first land surface,

[0012] A second land edge extending rearward from the front surface along the second land surface;

[0013] A first front edge formed at the intersection of a front surface and a first side surface, comprising a radially extended cutting edge portion;

[0014] A second front edge formed at the intersection of a front surface and a second side surface, comprising a second front edge that does not have a cutting edge portion;

[0015] The first side surface includes a rake surface adjacent to the cutting edge portion, and the rake surface faces the cutting rotation direction;

[0016] The first and second land edges are contained within the envelope of a virtual first cylinder having a circular cross-section and a cylinder axis coaxial with the insert axis, and the virtual first cylinder has a first diameter,

[0017] A virtual cutting profile formed by rotating the cutting edge portion 360 degrees around the insert axis is located axially forward of the second front edge and forms a cutting diameter corresponding to the first diameter.

[0018] In addition, according to the present invention, a rotary cutting tool is provided, which is

[0019] A tool shank extending in a shank axis direction determining the front and rear directions of the shank, wherein the tool shank comprises spaced first and second protrusions protruding from a front end portion and an insert receiving slot located between the first and second protrusions, and

[0020] It includes a rotary asymmetric cutting insert of the aforementioned type that is releasedly fixed to a tool shank within an insert receiving slot, and

[0021] The insert axis is coaxial with the shank axis;

[0022] The front surface of the insert faces the forward direction of the shank. Brief explanation of the drawing

[0023] For better understanding, the present invention will be described merely by way of example with reference to the accompanying drawings, in which dotted lines indicate cut-off boundaries for partial views of members. FIG. 1 is a perspective view of a cutting insert for some embodiments of the present invention. Figure 2 is a front view of the cutting insert shown in Figure 1. FIG. 3 is a first side view of the cutting insert shown in FIG. 1. Figure 4 is a second side view of the cutting insert shown in Figure 1. FIG. 5 is a third side view of the cutting insert shown in FIG. 1. FIG. 6 is a fourth side view of the cutting insert shown in FIG. 1. FIG. 7 is a first perspective view of a rotary cutting tool according to some embodiment of the present invention. FIG. 8 is a second perspective view of the rotary cutting tool shown in FIG. 7. Figure 9 is an exploded perspective view of the rotary cutting tool shown in Figure 7. Figure 10 is a front end view of the rotary cutting tool shown in Figure 7. FIG. 11 is a front end view of a tool shank according to some embodiment of the present invention. FIG. 12 is a cross-sectional view of the tool shank shown in FIG. 11, taken along line XII-XII. Specific details for implementing the invention

[0024] A first aspect of the present invention relates to a cutting insert (20) having opposing front surfaces (22) and rear surfaces (24) interconnected by an insert main surface (26), and an insert axis (AI) defining the insert front-rear direction (IF, IR).

[0025] As illustrated in FIGS. 1 to 6, the cutting insert (20) is rotatable in the cutting rotation direction (RC) about the insert axis (AI), and the insert peripheral surface (26) has first and second side surfaces (28, 30) spaced apart from each other by first and second land surfaces (32, 34). The cutting insert (20) is rotationally asymmetric about the insert axis (AI) (excluding rotations that double 360 ​​degrees).

[0026] In some embodiments of the present invention, the cutting insert (20) may preferably be manufactured by pressing and sintering a cemented carbide such as tungsten carbide, and may or may not be coated.

[0027] In addition, in some embodiments of the present invention, the cutting insert (20) may be an integral single-piece structure.

[0028] As shown in FIGS. 1 to 6, the first land edge (36) extends rearward from the front surface (22) along the first land surface (32), and the second land edge (38) extends rearward from the front surface (22) along the second land surface (34).

[0029] As illustrated in FIG. 2, the first and second land edges (36, 38) are contained within the envelope (40) of a virtual first cylinder (C1) having a circular cross section and a cylinder axis (AC) coaxial with the insert axis (AI), and the virtual first cylinder (C1) has a first diameter (D1).

[0030] Throughout the detailed description and claims, it should be noted that the virtual first cylinder (C1) may be finely axially tapered in the rearward direction (IR) such that the first diameter (D1) decreases to 0.01 mm along the length of the first land edge (36).

[0031] In some embodiments of the present invention, the first land edge (36) may be formed at the intersection of the first side surface (28) and the first land surface (32), and the second land edge (38) may be formed at the intersection between the second side surface (30) and the second land surface (34).

[0032] As shown in FIGS. 3 and 5, the first land edge (36) extends backward from the first endpoint (N1).

[0033] In some embodiments of the present invention, as shown in FIG. 2, the first endpoint (N1) and the insert axis (AI) may be included in the first insert plane (PI1).

[0034] In addition, in some embodiments of the present invention, the first land edge (36) may be straight and parallel to the insert axis (AI).

[0035] In addition, in some embodiments of the present invention, the first land edge (36) may intersect with the rear surface (24).

[0036] As illustrated in FIGS. 2 and 6, the second land surface (34) may include a first support surface (42) included in the envelope surface (40) of the virtual first cylinder (C1).

[0037] In some embodiments of the present invention, the first support surface (42) may extend circumferentially from the second land edge (38) in the opposite direction of the cutting rotation direction (RC).

[0038] As illustrated in FIG. 2, the first support surface (42) can be fully positioned in the first virtual quadrant (Q1) among the four virtual quadrants (Q1, Q2, Q3, Q4) defined by the first insert plane (PI1) which is perpendicular to the first insert plane (PI1) and intersects the second insert plane (PI2) which includes the insert axis (AI).

[0039] In some embodiments of the present invention, the first support surface (42) may intersect with the front surface (22).

[0040] Additionally, in some embodiments of the present invention, the first support surface (42) may intersect with the rear surface (24).

[0041] As shown in FIGS. 2 and 6, the first support surface (42) can be spaced apart from the first side surface (28) by the first intermediate surface (44).

[0042] In some embodiments of the present invention, the first intermediate surface (44) may be located radially inside the envelope surface (40) of the virtual first cylinder (CI).

[0043] Additionally, in some embodiments of the present invention, the first intermediate surface (44) may be a chamfered plane extending in the axial direction.

[0044] As shown in FIGS. 1 to 6, the first front edge (46) is formed at the intersection of the front surface (22) and the first side surface (28), and the first front edge (46) includes a radially extended cutting edge portion (48).

[0045] In some embodiments of the present invention, the cutting edge portion (48) may extend radially outward toward the first land edge (36).

[0046] As illustrated in FIG. 2, the cutting edge portion (48) may have a radially outermost cutting point (NRO) included in the envelope (40) of the virtual first cylinder (C1).

[0047] In some embodiments of the present invention, it should be noted that the outermost radial cutting point (NRO) may coincide with the first end point (N1) of the first land edge (36).

[0048] As illustrated in FIGS. 1 to 3, the first side surface (28) includes a rake surface (50) facing in the cutting rotation direction (RC) adjacent to the cutting edge portion (48).

[0049] In some embodiments of the present invention, the rake surface (50) may be a planar lower surface of the first side surface (28).

[0050] In another embodiment of the present invention (not shown), the rake surface (50) may include a recess or a plurality of recesses within the first side surface (28).

[0051] As shown in FIGS. 1, 2, and 4, the front surface (22) includes a relief surface (51) adjacent to the cutting edge portion (48).

[0052] In some embodiments of the present invention, the relief surface (51) may be multifaceted.

[0053] According to the present invention, the second front edge (52) is formed at the intersection of the front surface (22) and the second side surface (30), and the second front edge (52) does not have a cutting edge portion.

[0054] Considering the first front edge (46) having a radially extended cutting edge portion (48) and the second front edge (52) not having a cutting edge portion, the cutting insert (20) may be referred to as having a single radially extended cutting edge portion.

[0055] As illustrated in FIGS. 1 to 6, the cutting insert (20) may not have rotational symmetry about the insert axis (AI). As such, the cutting insert (20) is considered to be rotationally asymmetric about the insert axis (AI).

[0056] As shown in FIGS. 3 and 4, a virtual cutting profile (PC) formed by rotating the rotary cutting edge portion (48) 360 degrees around the insert axis (AI) is located axially forward of the entire second front edge (52).

[0057] Throughout the detailed description and claims, it should be noted that the relative axial position of the second forward edge (52) to the virtual cutting profile (PC) is considered within the same radial range from the insert axis (AI) of the second forward edge (52) and the virtual cutting profile (PC).

[0058] In some embodiments of the present invention, a virtual cutting profile (PC) may be located axially forward of any edge associated with the front surface (22), other than the cutting edge portion (48) itself that defines the virtual cutting profile (PC).

[0059] In addition, in some embodiments of the present invention, a virtual cutting profile (PC) may define a cutting diameter (DC) corresponding to a first diameter (D1).

[0060] Additionally, in some embodiments of the present invention, the cutting edge portion (48) may extend radially outward from the insert axis (AI).

[0061] As illustrated in FIGS. 2 to 4, the cutting edge portion (48) may have a radially innermost cutting point (NRI) that coincides with the insert axis (AI).

[0062] In some embodiments of the present invention, it should be noted that the innermost radial cutting point (NRI) may coincide with the center point (NC) of a virtual cutting profile (PC).

[0063] In some embodiments of the present invention, the radially innermost cutting point (NRI) may be located axially forward of the radially outermost cutting point (NRO).

[0064] As illustrated in FIGS. 2 to 4, the cutting edge portion (48) may have an axially foremost cutting point (NF) located in the radial middle between the insert axis (AI) and the envelope surface (40) of the virtual first cylinder (C1).

[0065] In an embodiment of the present invention, the cutting insert (20) is an integral monolithic structure and is manufactured by form pressing and sintering a cemented carbide alloy, and it should be noted that several insert sizes of different cutting diameters (DC) can be advantageously manufactured by applying a post-sintering processing step, for example, grinding, from a form-pressed green body of the same size.

[0066] As shown in FIG. 2, the first insert plane (PI1) may include a whole cutting edge portion (48).

[0067] In some embodiments of the present invention, the first insert plane (PI1) may include the entire first front edge (46).

[0068] In addition, in some embodiments of the present invention, the first side surface (28) may be flat.

[0069] Additionally, in some embodiments of the present invention, the cutting insert (20) may be used for drilling operations, and radial support within the workpiece (not shown) is advantageously provided by at least a first support surface (42) formed integrally.

[0070] It should be noted that the previously mentioned fine axial taper of the virtual first cylinder (C1) in the rearward direction (IR) is particularly suitable for the configuration of the cutting insert (20) used in the drilling operation.

[0071] As shown in FIGS. 2, 5, and 6, the shoulder portion (54) may protrude from the second side surface (30).

[0072] In some embodiments of the present invention, the shoulder portion (54) may have a second support surface (56) included in the envelope surface (40) of the virtual first cylinder (C1).

[0073] Additionally, in some embodiments of the present invention, the second support surface (56) may intersect with the front surface (22).

[0074] As illustrated in FIG. 2, the second support surface (56) may be located entirely in the second virtual quadrant (Q2), which is adjacent to the first virtual quadrant (Q1) and separated from it by the second insert plane (PI2).

[0075] For an embodiment of the present invention having two or more integrally formed support surfaces, namely, first and second support surfaces (42, 56) located respectively in adjacent first and second quadrants (Q1, Q2), a high level of radial support is provided within a drilled hole of a workpiece (not shown).

[0076] As illustrated in FIGS. 1, 2, and 5, the first land surface (32) may include a third support surface (58) included in the envelope surface (40) of the virtual first cylinder (C1).

[0077] In some embodiments of the present invention, the third support surface (58) may extend circumferentially from the first land edge (36) in the opposite direction of the cutting rotation direction (RC).

[0078] Additionally, in some embodiments of the present invention, the third support surface (58) may intersect with the front surface (22).

[0079] Additionally, in some embodiments of the present invention, the third support surface (58) may intersect with the rear surface (24).

[0080] As shown in FIGS. 1, 2, and 5, the second support surface (56) can be spaced apart from the third support surface (58) by the second intermediate surface (60).

[0081] As illustrated in FIG. 2, in some embodiments of the present invention, the second intermediate surface (60) may be located radially inside the envelope surface (40) of the virtual first cylinder (C1).

[0082] Additionally, in some embodiments, the shoulder portion (54) may be joined to the first land surface (32) through the second intermediate surface (60).

[0083] In addition, in some embodiments of the present invention, the second intermediate surface (60) may be planar.

[0084] As illustrated in FIG. 2, for embodiments of the present invention including a third support surface (58), the third support surface (58) can be fully located in the second virtual quadrant (Q2).

[0085] In an embodiment of the present invention having three integrally formed support surfaces located in the first and second virtual quadrants (Q1, Q2), namely the first, second, and third support surfaces (42, 56, 58), there are no support surfaces in the two virtual quadrants (Q3, Q4) located opposite the first insert plane (PI1), and sufficient lateral movement of the cutting insert (20) perpendicular to the insert axis (AI) can be made possible within the workpiece, and thus the cutting insert (20) can be released from the workpiece without snagging.

[0086] As shown in FIGS. 2, 4, and 6, the shoulder portion (54) may include a bonding surface (62) facing away from the first land surface (32).

[0087] In some embodiments of the present invention, the bonding surface (62) may be located radially inside the envelope surface (40) of the virtual first cylinder (C1) and may be adjacent to the second support surface (56).

[0088] Additionally, in some embodiments of the present invention, the bonding surface (62) may be located in the second virtual quadrant (Q2) and may face the second insert plane (PI2).

[0089] In addition, in some embodiments of the present invention, the bonding surface (62) may be planar.

[0090] Furthermore, in some embodiments of the present invention, when viewed along the insert axis (AI), the bonding surface (62) may be inclined at a bonding angle of less than 10 degrees with respect to the second insert plane (PI2).

[0091] In another embodiment of the present invention (not shown), the bonding surface (62) may be parallel to the second insert plane (PI2).

[0092] A second aspect of the present invention relates to a rotary cutting tool (64) having a tool shank (66) extending along a shank axis (AS) that defines the forward and backward directions (SF, SR) of the shank, and a cutting insert (20) that is releaseably fixed to the tool shank (66).

[0093] As illustrated in FIGS. 7 to 12, the tool shank (66) has spaced first and second protrusions (68, 70) protruding from its front end (72), and the cutting insert (20) is located in the insert receiving slot (74) between the first and second protrusions (68, 70).

[0094] In some embodiments of the present invention, the tool shank (66) may include one or more coolant passages (75a, 75b) extending axially through the first projection (68).

[0095] As shown in FIGS. 7 and 8, the insert axis (AI) is coaxial with the shank axis (AS), and the front surface (22) of the insert faces the shank forward direction (SF).

[0096] It should be noted that when held in the tool shank (66), at least a portion of the insert front surface (22) may be located axially forward of the first and second protrusions (68, 70) to the extent that it allows for the re-grinding of the front surface (22) and the reuse of the cutting insert (20) after wear and / or damage of the original cutting edge portion (48).

[0097] In some embodiments of the present invention, the tool shank (66) may have a generally cylindrical shank peripheral surface (76) having a shank diameter (DS), and the shank diameter (DS) may be smaller than the first diameter (D1).

[0098] Additionally, in some embodiments of the present invention, a shank flute (78) may be formed on a shank peripheral surface (76) extending rearward from a front end portion (72).

[0099] As shown in FIG. 11, the shank flute (78) may be substantially V-shaped when viewed along the shank axis (AS).

[0100] Although not shown in the drawing, it should be noted that the shank flute (78) may not extend along the entire axial length of the tool shank (66).

[0101] In some embodiments of the present invention, a rotary cutting tool (64) can be used for drilling operations.

[0102] Additionally, in some embodiments of the present invention, a rotary cutting tool (64) may be used to drill a hole with a significant depth relative to the cutting diameter (DC), i.e., deep drilling, also called deep hole drilling.

[0103] By positioning the cutting insert (20) within the insert receiving slot (74) between the first and second projections (68, 70) that are axially forward-protruding, in contrast to the gun-drill of the aforementioned US 7,393,162—where the cutting head disclosed in the aforementioned patent is detachably fixed to the shank disclosed in the aforementioned patent by relative rotation about the longitudinal rotation axis—it should be recognized that there is no risk of the cutting insert (20) being inadvertently separated from the tool shank (66) during a short reverse rotation of the rotary cutting tool (64) within the workpiece.

[0104] As illustrated in FIGS. 1 to 3, the first side surface (28) of the insert may include a first fixed surface (80) facing in the opposite direction of the cutting rotation direction (RC).

[0105] In some embodiments of the present invention, the first fixed surface (80) may intersect with the second land surface (34).

[0106] Additionally, in some embodiments of the present invention, the first fixed surface (80) may be a planar lower surface of the first side surface (28).

[0107] As illustrated in FIG. 10, the first clamping surface (81) of the first projection (68) can come into contact with the first fixed surface (80).

[0108] As shown in FIG. 4, the second side surface (30) of the insert may include three spaced-apart second fixed surfaces (82a, 82b, 82c) on the same plane.

[0109] In some embodiments of the present invention, three second fixed surfaces (82a, 82b, 82c) may be parallel to the first fixed surface (80).

[0110] It should be recognized that providing three second fixed surfaces (82a, 82b, 82c) on the same plane makes it advantageously easier to manufacture the first fixed surface (80) parallel thereto.

[0111] As illustrated in FIG. 10, the second clamping surface (83) of the second projection (70) may come into contact with at least one of the three second fixing surfaces (82a, 82b, 82c).

[0112] In some embodiments of the present invention, the second clamping surface (83) may face the first clamping surface (81).

[0113] As shown in FIGS. 3 and 4, the insert opening (84) can extend from the first side surface (28) of the insert to the second side surface (30) of the insert.

[0114] In some embodiments of the present invention, the insert opening (84) may be positioned asymmetrically with respect to the insert axis (AI).

[0115] Additionally, in some embodiments of the present invention, the insert opening (84) may extend to the rear surface (24). Thus, the insert opening (84) may be opened to the first and second side surfaces (28, 30) of the insert, and also to the rear surface (24) of the insert.

[0116] In an embodiment of the present invention in which the insert opening (84) extends to the rear surface (24), the insert opening (84) may have an elongated slot shape.

[0117] Additionally, in an embodiment of the present invention in which the insert opening (84) extends to the rear surface (24), the rear surface (24) may include two spaced rear lower surfaces (24a, 24b).

[0118] In an embodiment of the present invention (not shown), the insert opening (84) may be in the form of an insert through bore extending from the first side surface (28) to the second side surface (30).

[0119] As illustrated in FIGS. 8 to 10, a clamping bolt (86) can extend through the insert opening (84) and clamp the first and second protrusions (68, 70) to the first and second side surfaces (28, 30) of the insert, respectively.

[0120] In some embodiments of the present invention, the insert opening (84) may be opened to the first fixed surface (80) of the first side surface (28) of the insert.

[0121] It should be noted that configuring the insert opening (84) to be positioned asymmetrically with respect to the insert axis (AI) can advantageously reduce the risk of the rotary cutting tool (64) being assembled incorrectly.

[0122] In some embodiments of the present invention, the clamping bolt (86) may extend through the shank through bore (88) in the second projection (70) and may be screw-coupled with the shank screw bore (90) of the first projection (68).

[0123] For an embodiment of the present invention in which the insert opening (84) extends to the rear surface (24), in contrast to the form of an insert through bore, the cutting insert (20) can be removed and replaced without separating the clamping bolt (86) from the shank screw bore (90) in the first projection (68), but instead by simply releasing the clamping force between the first and second projections (68, 70).

[0124] In some embodiments of the present invention, the second projection (70) may include a countersink hole (92) that is coaxial with the shank through bore (88) and opens to the shank peripheral surface (86).

[0125] It should be noted that the countersink hole (92) may have a larger diameter than the shank through bore (88) to provide sufficient space for the bolt head (94) of the clamping bolt (86).

[0126] As shown in FIG. 7, the rear surface (24) of the insert can come into contact with the bottom surface (96) of the insert receiving slot (74).

[0127] In an embodiment of the present invention in which the rear surface (24) comprises two spaced rear lower surfaces (24a, 24b), the two coplanar regions of the rear lower surfaces (24a, 24b) may come into contact with the bottom surface (96) of the insert receiving slot (74).

[0128] In some embodiments of the present invention, the rear surface (24) of the insert may be inclined in the rear direction (IR) of the insert from the first land surface (32) to the second land surface (34).

[0129] In an embodiment of the present invention in which the rear surface (24) of the insert is inclined in the rear direction (IR) of the insert from the first land surface (32) to the second land surface (34), the bottom surface (96) of the insert receiving slot may be inclined together with it in correspondence.

[0130] It should be noted that configuring the rear surface (24) of the insert to be inclined can advantageously reduce the risk of the rotary cutting tool (64) being assembled incorrectly.

[0131] As shown in FIG. 10, the bonding surface (62) of the shoulder portion (54) of the insert can come into contact with the bonding wall (98) of the second projection (70).

[0132] It should be noted that during the assembly of the rotary cutting tool (64), when the tool shank (66) is oriented in an 'upright' position, that is, the forward direction of the shank (SF) is oriented opposite to the direction of gravity, the inclination of the rear surface (24) of the insert and the bottom surface (96) of the insert receiving slot favorably promotes contact between the joining surface (62) and the joining wall (98).

[0133] Additionally, it should be noted that the slope of the rear surface (24) of the insert and the bottom surface (96) of the insert receiving slot can advantageously facilitate contact between the joining surface (62) and the joining wall (98) during the use of a rotary cutting tool (64) in a drilling operation.

[0134] In some embodiments of the present invention, it should be noted that due to manufacturing tolerances and inaccuracies, the bonding surface (62) may only come into contact with the vertical edge (99) of the bonding wall (98).

[0135] As shown in FIGS. 11 and 12, a first shank plane (PS1) parallel to the shank axis (AS) divides the insert receiving slot (74) along the length of the slot, and first and second protrusions (68, 70) are respectively located on the opposing first and second plane sides (S1, S2) of the first shank plane (PS1).

[0136] In some embodiments of the present invention, the shank flute (78) may be located on the first plane side (S1) of the first shank plane (PS1).

[0137] Additionally, in some embodiments of the present invention, the shank axis (AS) may be located on the first plane side (S1) of the first shank plane (PS1).

[0138] Additionally, in some embodiments of the present invention, the first insert plane (PI1) may be parallel to the first shank plane (PS1) and offset therefrom.

[0139] Furthermore, in some embodiments of the present invention, the shank flute (78) may be in communication with the insert receiving slot (74).

[0140] Although the present invention has been described in some detail, it should be understood that various modifications and variations may be made without departing from the spirit or scope of the invention as claimed below.

Claims

Claim 1 A rotationally asymmetric cutting insert (20) rotatable about an insert axis (AI) in a cutting rotation direction (RC), wherein the insert axis (AI) defines the insert forward and backward directions (IF, IR), and the cutting insert (20) is an opposing front and rear surface (22, 24) interconnected by an insert peripheral surface (26), wherein the insert peripheral surface (26) has first and second side surfaces (28, 30) spaced apart by first and second land surfaces (32, 34); A first land edge (36) formed at the intersection of a first side surface (28) and a first land surface (32), wherein the first land edge (36) extends rearward along the first land surface (32) from a first endpoint (N1) formed at the intersection of a front surface (22), a first side surface (28), and a first land surface (32); a second land edge (38) formed at the intersection of a second side surface (30) and a second land surface (34), extending rearward along the second land surface (34) from the front surface (22); and a first front edge (46) formed at the intersection of a front surface (22) and a first side surface (28), comprising a cutting edge portion (48) extending radially outward toward the first land edge (36). A second front edge (52) formed at the intersection of the front surface (22) and the second side surface (30) and not having a cutting edge; a first insert plane (PI1) including an insert axis (AI) and a first endpoint (N1);and a second insert plane (PI2) perpendicular to the first insert plane (PI1) and including the insert axis (AI), wherein the second insert plane (PI2) forms the first, second, third, and fourth virtual quadrants (Q1, Q2, Q3, Q4) by intersecting the first insert plane (PI1); the first side surface (28) includes a rake surface (50) adjacent to the cutting edge portion (48), the rake surface (50) faces the cutting rotation direction (RC); the first and second land edges (36, 38) are included in the envelope (40) of a virtual first cylinder (C1) having a circular cross section and a cylinder axis (AC) coaxial with the insert axis (AI), the virtual first cylinder (C1) has a first diameter (D1), and is formed by rotating the cutting edge portion (48) 360 degrees around the insert axis (AI). A virtual cutting profile (PC) is positioned axially forward of the second front edge (52) and forms a cutting diameter (DC) corresponding to the first diameter (D1), and the second land surface (34) includes a first support surface (42) included in the envelope surface (40) of the virtual first cylinder (C1), and when the cutting insert (20) is viewed from the front, the first support surface (42) is completely located in the first virtual quadrant (Q1), the cutting insert (20).; Claim 2 In claim 1, the virtual cutting profile (PC) is a cutting insert (20) located axially forward of any edge associated with the front surface (22), in addition to the cutting edge portion (48). Claim 3 delete Claim 4 In claim 1, the first land edge (36) is a straight cutting insert (20) parallel to the insert axis (AI). Claim 5 delete Claim 6 In claim 1, the cutting edge portion (48) is a cutting insert (20) that extends radially outward from the insert axis (AI). Claim 7 delete Claim 8 A cutting insert (20) in which the entire cutting edge portion (48) is included in the first insert plane (PI1). Claim 9 delete Claim 10 A cutting insert (20) having a shoulder portion (54) protruding from a second side surface (30) and a second supporting surface (56) included in the envelope surface (40) of a virtual first cylinder (C1). Claim 11 In claim 10, the second support surface (56) is a cutting insert (20) that is entirely located in the second virtual quadrant (Q2), which is adjacent to the first virtual quadrant (Q1) in the circumferential direction and separated from it by the second insert plane (PI2). Claim 12 In claim 11, the first land surface (32) includes a third support surface (58) contained in the envelope surface (40) of a virtual first cylinder (C1), and the third support surface (58) is a cutting insert (20) that is fully located in the second virtual quadrant (Q2). Claim 13 In claim 1, the cutting edge portion (48) is a cutting insert (20) having an axially foremost cutting point (NF) located in the radial middle between the insert axis (AI) and the envelope surface (40) of the virtual first cylinder (C1). Claim 14 A cutting insert (20) in which the insert opening (84) extends from the first side surface (28) to the second side surface (30). Claim 15 In paragraph 14, the insert opening (84) is a cutting insert (20) positioned asymmetrically with respect to the insert axis (AI). Claim 16 A rotary cutting tool (64), and a tool shank (66) extending in the direction of a shank axis (AS) forming the front and rear directions (SF, SR) of the shank, wherein the tool shank (66) comprises first and second protrusions (68, 70) that are circumferentially spaced apart and protrude axially from a front end portion (72), and an insert receiving slot (74) located between the first and second protrusions (68, 70); A rotationally asymmetric cutting insert (20) rotatable about an insert axis (AI) in a cutting rotation direction (RC), wherein the insert axis (AI) defines the insert forward and backward directions (IF, IR), and the cutting insert (20) is an opposing front and rear surface (22, 24) interconnected by an insert peripheral surface (26), wherein the insert peripheral surface (26) has first and second side surfaces (28, 30) separated by first and second land surfaces (32, 34); A first land edge (36) extending rearward along the first land surface (32) from the front surface (22); a second land edge (38) extending rearward along the second land surface (34) from the front surface (22); a first front edge (46) formed at the intersection of the front surface (22) and the first side surface (28) and including a radially extended cutting edge portion (48);A second front edge (52) is formed at the intersection of the front surface (22) and the second side surface (30) and does not have a cutting edge portion, and the first side surface (28) includes a rake surface (50) adjacent to the cutting edge portion (48), the rake surface (50) faces the cutting rotation direction (RC), and the first and second land edges (36, 38) are included in the envelope (40) of a virtual first cylinder (C1) having a circular cross section and a cylinder axis (AC) coaxial with the insert axis (AI), the virtual first cylinder (C1) has a first diameter (D1), and a virtual cutting profile (PC) formed by rotating the cutting edge portion (48) 360 degrees around the insert axis (AI) is located axially forward of the second front edge (52) and includes a cutting insert (20) that forms a cutting diameter (DC) corresponding to the first diameter (D1), and cutting An insert (20) is releasedly fixed to a tool shank (66) within an insert receiving slot (74); the insert axis (AI) is coaxial with the shank axis (AS); and the front surface (22) of the insert faces the shank forward direction (SF), forming a rotary cutting tool (64). Claim 17 In claim 16, the tool shank (66) has a generally cylindrical shank peripheral surface (76) having a shank diameter (DS) smaller than the first diameter (D1), and the shank flute (78) is formed on the shank peripheral surface (76) extending rearward from the front end portion (72), a rotary cutting tool (64). Claim 18 In claim 16, the cutting insert (20) has an insert opening (84) extending from the first side surface (28) of the insert to the second side surface (30) of the insert, and a clamping bolt (86) extends through the insert opening (84) and clamps the first and second protrusions (68, 70) respectively on the first and second side surfaces (28, 30) of the insert, a rotary cutting tool (64). Claim 19 In claim 16, the insert receiving slot (74) has a bottom surface (96), the rear surface (24) of the insert contacts the bottom surface (96) of the insert receiving slot, the rear surface (24) of the insert is inclined in the insert rear direction (IR) from the first land surface (32) to the second land surface (34), and the bottom surface (96) of the insert receiving slot is inclined together with the rear surface (24) of the insert in correspondence, a rotary cutting tool (64). Claim 20 In claim 16, the second projection (70) of the shank has a joining wall (98), and the cutting insert (20) has a shoulder portion (54) protruding from the second side surface (30), the shoulder portion (54) includes a joining surface (62) facing away from the first land surface (32), and the joining surface (62) contacts the joining wall (98) of the second projection (70), a rotary cutting tool (64). Claim 21 In claim 16, the first projection (68) of the shank has a first clamping surface (81), the first side surface (28) of the insert includes a first fixed surface (80) facing the opposite direction of the cutting rotation direction (RC), and the first clamping surface (81) of the first projection (68) contacts the first fixed surface (80), a rotary cutting tool (64). Claim 22 In claim 21, the second projection (70) of the shank has a second clamping surface (83), the second side surface (30) of the insert includes three coplanar second fixing surfaces (82a, 82b, 82c), and the second clamping surface (83) of the second projection (70) contacts at least one of the three second fixing surfaces (82a, 82b, 82c), a rotary cutting tool (64). Claim 23 In paragraph 22, the three second fixed surfaces (82a, 82b, 82c) are a rotary cutting tool (64) parallel to the first fixed surface (80).

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