Cutting insert, body, and cutting tool

Abstract

To provide a cutting insert, a body, and a cutting tool capable of suppressing a thickness while being usable by switching four cutting edges.SOLUTION: A cutting insert 30 attached to a body 20 of a cutting tool 10 includes: a first surface 110 having a substantially parallelogram shape, including one end surface among a pair of end surfaces facing each other, and functioning as a surface including first rake surfaces 151, 152; a pair of first cutting edges 511, 512 formed along a pair of sides 111, 113 facing each other among sides defining the first surface 110; second surfaces 210, 220 having a substantially trapezoidal shape, including a pair of side surfaces facing each other, and functioning as a surface including second rake surfaces 621, 622; and second cutting edges 521, 522 formed along one side 201, 203 among sides defining the second surfaces 210, 220.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cutting insert, a body, and a cutting tool. [Background technology]

[0002] A known cutting tool has a configuration in which multiple cutting inserts are arranged circumferentially around the outer periphery of a rotating body. Each cutting insert can be removed from the body and replaced. For example, as described in Patent Document 1 below, a cutting tool is also known in which multiple cutting edges are provided on a single cutting insert, and the cutting edge used for machining can be switched by changing the mounting state of the cutting insert relative to the body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5779830 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in a configuration in which the cutting edge used for machining can be changed by rotating the cutting insert 180 degrees around an axis perpendicular to the center axis of rotation of the body, two cutting edges located diagonally opposite each other can be switched and used.

[0005] Furthermore, if the cutting insert can be installed upside down, it would be possible to switch between four cutting edges. However, in such a configuration, the cutting insert may become too thick, making it difficult to perform small diameter machining.

[0006] An object of the present invention is to provide a cutting insert, a body, and a cutting tool that can suppress thickness while allowing a total of four cutting edges to be switchably used. [Means for solving the problem]

[0007] A cutting insert according to one embodiment of the present invention is a cutting insert that is attached to the body of a cutting tool, and has a first surface that is approximately parallelogram-shaped and consists of one end surface of a pair of opposing end surfaces and functions as a surface including a first cutting surface, a pair of first cutting edges formed along a pair of opposing sides that define the first surface, a second surface that is approximately trapezoidal and consists of a pair of opposing side surfaces and functions as a surface including a second cutting surface, and a second cutting edge formed along one of the sides that define each second surface.

[0008] In the cutting insert with the above structure, two first cutting edges formed along a pair of sides that define a first surface that is a substantially parallelogram shape made up of one end face can be used, and two second cutting edges formed along sides that define a second surface that is a substantially trapezoid shape made up of a pair of opposing side faces can be used. In other words, by changing the posture and orientation when attaching the cutting insert to the body, it is possible to switch between and use a total of four cutting edges.

[0009] The first rake face may be formed of a groove portion that extends along the first cutting edge and is recessed in a curved shape in a cross section perpendicular to the direction of extension.

[0010] The through hole may have a pair of opening end faces, and the through hole may have enlarged diameter portions at both ends that enlarge in diameter toward the end faces.

[0011] A body according to one embodiment of the present invention is a body to which a cutting insert is attached, the cutting insert having: a first surface of approximately parallelogram shape consisting of one end surface of a pair of opposing end surfaces and functioning as a surface including a first cutting surface; a pair of first cutting edges formed along a pair of opposing sides that define the first surface; a second surface of approximately trapezoid shape consisting of a pair of opposing side surfaces that function as a surface including a second cutting surface; and a second cutting edge formed along one of the sides that define each second surface; and the body has a first mounting seat to which the cutting insert is attached in a first position in which the first cutting edge can be used as a cutting edge during cutting, and a second mounting seat to which the cutting insert is attached in a second position in which the second cutting edge can be used as a cutting edge during cutting.

[0012] The body may be rotatable around a central rotation axis, and a first mounting seat and a second mounting seat may be arranged along the central rotation axis.

[0013] A cutting tool according to one embodiment of the present invention comprises a cutting insert having a first surface having an approximately parallelogram shape, consisting of one of a pair of opposing end surfaces and functioning as a surface including a first cutting surface, a pair of first cutting edges formed along a pair of opposing sides that define the first surface, a second surface having an approximately trapezoid shape, consisting of a pair of opposing side surfaces that function as a surface including a second cutting surface, and a second cutting edge formed along one of the sides that define each second surface, a body having a first mounting seat on which the cutting insert is mounted in a first position in which the first cutting edge can be used as a cutting edge during cutting, and a second mounting seat on which the cutting insert is mounted in a second position in which the second cutting edge can be used as a cutting edge during cutting.

[0014] The first rake face may be formed of a groove portion extending along the first cutting edge and formed so as to be recessed in a curved shape in a cross section perpendicular to the direction of extension.

[0015] The cutting insert may have a through hole that opens at a pair of end surfaces, and the through hole may have, at both ends thereof, expanded diameter portions that expand in diameter toward the end surfaces.

[0016] The body may be rotatable around a central axis of rotation, and may have a first mounting seat and a second mounting seat arranged along the central axis of rotation. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a cutting insert, a body, and a cutting tool that can suppress the thickness while allowing a total of four cutting edges to be switchably used. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a cutting tool provided with a cutting insert according to this embodiment. [Figure 2] FIG. 2 is a front view of a cutting tool provided with a cutting insert according to this embodiment. [Figure 3] FIG. 3 is a side view of a cutting tool provided with the cutting insert according to this embodiment. [Figure 4] FIG. 4 is a perspective view of the cutting insert in a first position. [Figure 5] FIG. 5 is a perspective view of the cutting insert in the second position. [Figure 6] FIG. 6 is a plan view of the cutting insert as seen from the other first surface which is the other end surface. [Figure 7] FIG. 7 is a side view of the cutting insert as viewed from the second surface. [Figure 8] FIG. 8 is a plan view of the cutting insert as viewed from one first surface which is one end surface of the cutting insert. [Figure 9] FIG. 9 is a side view of the cutting insert as viewed from the third surface. [Figure 10] FIG. 10 is a cross-sectional view taken along line XX in FIG. [Figure 11] FIG. 11 is an enlarged view of part A in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0020] This embodiment will be described. The cutting tool 10 according to this embodiment is a milling tool for cutting the inner surface of a pipe or the like while rotating, and is also called a "pull counter boring tool." Note that the configuration of the cutting tool 10 described below can also be applied to other milling tools.

[0021] Fig. 1 is a perspective view showing the appearance of cutting tool 10. Fig. 2 is a front view of cutting tool 10 of Fig. 1 as viewed from the tip side along a central axis of rotation AX1. Fig. 3 is a side view showing the appearance of cutting tool 10. As shown in Figs. 1 to 3, cutting tool 10 has a plurality of cutting inserts 30 attached to a body 20.

[0022] The body 20 is the main body of the cutting tool 10, and is attached to a holder such as an arbor and held together with the holder by a machine tool (not shown). The body 20 has a generally cylindrical shape, and its central axis coincides with the central axis of rotation AX1. During machining, the driving force of the machine tool causes the body 20 to rotate about the central axis of rotation AX1. In FIGS. 1 and 2, the direction of rotation is indicated by an arrow.

[0023] The body 20 has a plurality of first mounting seats 810 and a plurality of second mounting seats 820. The first mounting seats 810 and the second mounting seats 820 are arranged so as to be aligned, for example, at equal intervals in the circumferential direction. The first mounting seats 810 and the second mounting seats 820 may also be arranged so as to be aligned at unequal intervals in the circumferential direction. The first mounting seats 810 and the second mounting seats 820 are arranged along the central axis of rotation AX1. The first mounting seat 810 is provided at the front end of the body 20, and the second mounting seat 820 is provided on the rear end side of the body 20 relative to the first mounting seat 810.

[0024] The cutting insert 30 is a member on which a first cutting edge 511, a second cutting edge 521, etc. are formed for cutting a workpiece. A plurality of cutting inserts 30 are attached to the body 20 as described above. The shapes of the respective cutting inserts 30 are identical to one another. The cutting inserts 30 are attached to a first mounting seat 810 and a second mounting seat 820 of the body 20 by screws 50. The cutting insert 30 is attached to the body 20 in a first orientation at the first mounting seat 810, and is attached to the body 20 in a second orientation at the second mounting seat 820.

[0025] 4 to 11, and also with reference to Figures 1 to 3 as necessary, the configuration of the cutting insert 30 will be described. The cutting insert 30 has a first surface 110, second surfaces 210, 220, third surfaces 310, 320, fourth surfaces 410, 420, and a fifth surface 120.

[0026] The first surface 110 and the fifth surface 120 are a pair of end surfaces of the cutting insert 30, and are surfaces that face each other. The first surface 110 is the surface on the front side of the paper in Fig. 4, and the other, the fifth surface 120, is the surface on the back side of the paper in Fig. 4. The second surfaces 210, 220 and the third surfaces 310, 320 are side surfaces that connect the first surface 110 and the fifth surface 120, which are end surfaces of the cutting insert 30, and are surfaces that face each other.

[0027] The first surface 110 is a surface that includes a surface that functions as a rake face (first rake faces 151, 152) during machining when the cutting insert 30 is attached to the first mounting seat 810, and a surface that includes a surface that functions as a seating surface 611 that abuts against the first mounting surface 821 of the second mounting seat 820 when the cutting insert 30 is attached to the second mounting seat 820. The fifth surface 120 is a surface that functions as a seating surface that abuts against the first mounting surface 811 of the first mounting seat 810 when the cutting insert 30 is attached to the first mounting seat 810.

[0028] The first surface 110 is a substantially parallelogram-shaped surface and is defined by four sides 111, 112, 113, and 114. Of these, the sides 111 and 113 are a pair of sides parallel to each other, and the sides 112 and 114 are a pair of sides parallel to each other. The intersection angle between the extension lines of the sides 111 and 112 and the intersection angle between the extension lines of the sides 113 and 114 are obtuse angles, and the intersection angle between the extension lines of the sides 112 and 113 and the intersection angle between the extension lines of the sides 114 and 111 are acute angles. In this embodiment, the length of the side 111 is the same as the length of the side 113, the length of the side 112 is the same as the length of the side 114, and the lengths of the sides 111 and 113 are different from the lengths of the sides 112 and 114, but the sides 111, 112, 113, and 114 may all be the same length.

[0029] Like the first surface 110, the fifth surface 120 is also a substantially parallelogram-shaped surface and is defined by four sides 121, 122, 123, and 124. Of these, the sides 121 and 123 are a pair of parallel sides, and the sides 122 and 124 are a pair of parallel sides. The intersection angle between the extension lines of the sides 121 and 122 and the intersection angle between the extension lines of the sides 123 and 124 are obtuse angles, and the intersection angle between the extension lines of the sides 122 and 123 and the intersection angle between the extension lines of the sides 124 and 121 are acute angles. In this embodiment, the length of the side 121 is the same as the length of the side 123, the length of the side 122 is the same as the length of the side 124, and the lengths of the sides 121 and 123 are different from the lengths of the sides 122 and 124; however, the sides 121, 122, 123, and 124 may all be the same length.

[0030] The sides 111, 112, 113, and 114 that define the first surface 110 and the sides 121, 122, 123, and 124 that define the fifth surface 120 can also be said to be the intersection ridges between the first surface 110 and the fifth surface 120 and the second surfaces 210, 220 and the third surfaces 310, 320.

[0031] The second surfaces 210 and 220 are surfaces facing each other. The second surfaces 210 and 220 include a surface that abuts against the third mounting surface 813 of the first mounting seat 810 when the cutting insert 30 is attached to the first mounting seat 810, and function as the first flank surfaces 651 and 652 during machining. The second surfaces 210 and 220 include a surface that abuts against the third mounting surface 823 of the second mounting seat 820 when the cutting insert 30 is attached to the second mounting seat 820, and function as the surface that includes the second rake faces 621 and 622 during machining.

[0032] One second surface 210 is a substantially trapezoidal surface defined by four sides 201, 123, 202, and 111. Of these, sides 123 and 111 are parallel to each other. Similar to one second surface 210, the other second surface 220 is a substantially trapezoidal surface defined by four sides 203, 121, 204, and 113. Of these, sides 121 and 113 are parallel to each other.

[0033] The third surfaces 310 and 320 are surfaces facing each other. The third surfaces 310 and 320 include surfaces that come into contact with the mounting surface of the first mounting seat 810 when the cutting insert 30 is mounted on the first mounting seat 810, and include surfaces that function as second flank surfaces 661 and 662 during machining when the cutting insert 30 is mounted on the second mounting seat 820.

[0034] One third surface 310 is a substantially quadrangular surface and is defined by four sides 201, 124, 204, and 114. Of these, sides 201 and 204 are parallel to each other, and sides 124 and 114 are parallel to each other. Similar to one third surface 310, the other third surface 320 is a substantially quadrangular surface and is defined by four sides 202, 122, 203, and 112. Of these, sides 202 and 203 are parallel to each other, and sides 122 and 112 are parallel to each other.

[0035] The fourth surfaces 410, 420 are surfaces that face each other and are included in the third surface. The fourth surface may be a surface that does not abut against the mounting surface of the first mounting seat 810 when the cutting insert is mounted on the first mounting surface 810, but a surface that abuts against the mounting surface of the first mounting seat 810, or a surface that does not abut against the mounting surface of the second mounting seat 820 when the cutting insert is mounted on the second mounting surface 820, but a surface that abuts against the mounting surface of the second mounting seat 820.

[0036] One fourth surface 410 is provided on one third surface 310 on the side of one first surface 110, and is a surface perpendicular to the first surface 110. The one fourth surface 410 gradually decreases in width from the one second surface 210 to the other second surface 220. The other fourth surface 420 is provided on the other third surface 320 on the side of the first surface 110, and is a surface perpendicular to the first surface 110. The other fourth surface 420 gradually decreases in width from the other second surface 220 to the one second surface 210.

[0037] The cutting insert 30 is formed with a total of four cutting edges (two first cutting edges 511, 512 and two second cutting edges 521, 522).

[0038] Of the total four cutting edges formed on the cutting insert 30, the two first cutting edges 511, 512 are both provided along the sides that define the first surface 110 (see FIG. 4). Specifically, the first cutting edge 511 is provided along the side 111 at the same position as the side 111, and the first cutting edge 512 is provided along the side 113 at the same position as the side 113. In the cutting insert 30, the lengths of the first cutting edges 511, 512 are the same as each other.

[0039] Of the total four cutting edges formed on the cutting insert 30, the two second cutting edges 521, 522 are provided along the sides that define the second surfaces 210, 220. Specifically, the second cutting edge 521 is provided along the side 201 of the second surface 210 at the same position as the side 201, and the second cutting edge 522 is provided along the side 203 of the second surface 220 at the same position as the side 203. The lengths of the respective second cutting edges 521, 522 are the same as each other.

[0040] Of the multiple cutting edges of the cutting insert 30, only one actually functions as a "cutting edge" during machining. Which of the first cutting edges 511, 512 and the second cutting edges 521, 522 functions as a "cutting edge" varies depending on the attachment state of the cutting insert 30 to the body 20.

[0041] When the cutting insert 30 is in a first position attached to the first mounting seat 810 of the body 20, one of the first cutting edge 511 or the first cutting edge 512 located closest to the tip actually functions as a "cutting edge." When the first cutting edge 511 of the cutting insert 30 functions as a cutting edge, the first surface 110 becomes a surface including a first rake face 151 (described later) and actually functions as a surface including a "rake face," and the second surface 210 becomes a first flank face 651 and actually functions as a "flank." When the first cutting edge 512 of the cutting insert 30 functions as a cutting edge, the first surface 110 becomes a surface including a first rake face 152 (described later) and actually functions as a surface including a "rake face," and the second surface 220 becomes a first flank face 652 and actually functions as a "flank."

[0042] When the cutting insert 30 is in the second posture attached to the second mounting seat 820 of the body 20, one of the second cutting edges 521 or 522 located closest to the tip actually functions as the "cutting edge." When the second cutting edge 521 of the cutting insert 30 functions as the cutting edge, the second surface 210 becomes a surface including a second rake face 621 (described later) and actually functions as the surface including the "rake face," and the third surface 310 becomes a second flank face 661 and actually functions as the "flank." When the second cutting edge 522 of the cutting insert 30 functions as the cutting edge, the second surface 220 becomes a surface including a second rake face 622 (described later) and actually functions as the surface including the "rake face," and the third surface 320 becomes a second flank face 662 and actually functions as the "flank."

[0043] The cutting insert 30 has a through hole 700. This through hole 700 is formed from a first surface 110, which is one end face, to a fifth surface 120, which is the other end face. This through hole 700 is formed perpendicular to the first surface 110 and the fifth surface 120, in which openings 701 and 702 are formed. The openings 701 and 702 of the through hole 700 open to the first surface 110 and the fifth surface 120. Furthermore, the through hole 700 has, on the openings 701 and 702 sides, expanding diameter portions 701a and 702a that gradually expand in diameter toward the first surface 110 and the fifth surface 120.

[0044] The through hole 700 is a hole through which the screw 50 is inserted when fixing the cutting insert 30 to the body 20, and the screw 50 is inserted from either one of the openings 701 or 702. The head 50a of the screw 50 inserted into the through hole 700 engages with either the enlarged diameter portion 701a or 702a. In other words, when the screw 50 is inserted from the opening 701, the head 50a of the screw 50 engages with the enlarged diameter portion 701a on the opening 701 side, and when the screw 50 is inserted from the opening 702, the head 50a of the screw 50 engages with the enlarged diameter portion 702a on the opening 702 side.

[0045] The axis AX2 is an axis that passes through the center of the through hole 700. This axis AX2 passes through the geometric center of the entire outer shape of the cutting insert 30. When the cutting insert 30 is rotated 180 degrees around the axis AX2, the entire shape of the cutting insert 30 after the rotation overlaps with the shape of the cutting insert 30 before the rotation. Such an axis AX2 exists because the shape of the cutting insert 30 has the symmetry described above.

[0046] For example, when the cutting insert 30 is attached to the first mounting seat 810 of the body 20 in the first position, causing the first cutting edge 511 to function as the actual "cutting edge," and then rotated 180 degrees around the axis AX2 and attached to the first mounting seat 810 of the body 20, the first cutting edge 512 will function as the actual "cutting edge."

[0047] The cutting insert 30 has first rake faces 151 and 152, each consisting of a pair of grooves, on the first surface 110. One first rake face 151 is formed on the first surface 110 along the first cutting edge 511, and the other first rake face 152 is formed on the first surface 110 along the first cutting edge 512. As shown in FIG. 11 , the one first rake face 151 has a curved concave shape in a cross section along the axis AX2 and perpendicular to the second surfaces 210 and 220. Similarly, the other first rake face 152 has a curved concave shape in a cross section along the central axis AX2 and perpendicular to the second surfaces 210 and 220. That is, the first rake faces 151 and 152 extend along the first cutting edges 511 and 512, respectively, and are formed to be curved concave in a cross section perpendicular to the extension direction. By configuring the first rake faces 151, 152 from the grooves formed as described above, a positive rake angle can be imparted when the first surface 110 is a surface including the rake faces. Furthermore, when the first surface 110 is a surface including the seating surface 611, the following advantage is achieved. Specifically, if the seating surface 611 is located lower than the first cutting edge 511 and the second cutting edge 512 when viewed from above along the axis AX2, the first mounting surface 821 of the second mounting seat 820 would have to be convex. However, by configuring the first rake faces 151, 152 from the grooves described above, the seating surface 611 can be the outermost surface (top surface) when viewed from above along the axis AX2. As a result, the first mounting surface 821 of the second mounting seat 820 does not need to be convex, and can be a simple flat surface, thereby reducing the manufacturing cost of the body 20.

[0048] 1 and 3, a first mounting seat 810 and a second mounting seat 820 provided on the body 20 are arranged along the rotation center axis AX1. The first mounting seat 810 is provided at the front end of the body 20, and the second mounting seat 820 is provided on the rear end side of the body 20 relative to the first mounting seat 810. As a result, the cutting insert 30 attached in the second position is disposed rearward of the rotation center axis AX1 relative to the cutting insert 30 attached in the first position. Furthermore, the first mounting seat 810 is formed radially inward of the body 20 relative to the second mounting seat 820. Therefore, the cutting insert 30 attached in the second position rearward of the rotation center axis AX1 is disposed radially outward relative to the cutting insert 30 attached in the first position at the front end side of the body 20.

[0049] The first mounting seat 810 of the body 20, to which the cutting insert 30 is attached in the first attitude, has a first mounting surface 811, a second mounting surface 812, a third mounting surface 813, and a fourth mounting surface 814. The first mounting surface 811 is the mounting surface on the rear side of the first mounting seat 810 in the rotation direction, and is formed with a threaded hole (not shown) into which the screw 50 is threaded. The second mounting surface 812 and the fourth mounting surface 814 are mounting surfaces on the inner side in the radial direction of the first mounting seat 810. The third mounting surface 813 is the mounting surface on the rear side of the rotation center axis AX1 of the first mounting seat 810.

[0050] The second mounting seat 820 of the body 20, to which the cutting insert 30 is attached in the second attitude, has a first mounting surface 821, a second mounting surface 822, and a third mounting surface 823. The first mounting surface 821 is a mounting surface on the radially inner side, and a threaded hole (not shown) into which the screw 50 is threaded is formed in the first mounting surface 821. The second mounting surface 822 is a mounting surface on the rear side of the rotation center axis AX1 in the second mounting seat 820. The third mounting surface 823 is a mounting surface on the rear side in the rotation direction in the second mounting seat 820.

[0051] Next, the attachment of the cutting insert 30 to the body 20 will be described.

[0052] (Attachment to the first mounting seat 810) (1) When using the first cutting edge 511 When the cutting insert 30 is attached to the first mounting seat 810 and the first cutting edge 511 is used as an actual "cutting edge," the cutting insert 30 is set in a first position with the first cutting edge 511 facing the tip side of the body 20 and fitted into the first mounting seat 810. As a result, the fifth surface 120 of the cutting insert 30 abuts against the first mounting surface 811, the third surface 310 and the fourth surface 410 abut against the second mounting surface 812 and the fourth mounting surface 814, and the second surface 220 abuts against the third mounting surface 813.

[0053] In this state, the screw 50 is inserted into the through hole 700 of the cutting insert 30 from its opening 701 and screwed into the threaded hole in the first mounting surface 811 of the first mounting seat 810. As a result, the cutting insert 30 is attached to the first mounting seat 810 of the body 20 in a first attitude in which the first cutting edge 511 is used as an actual "cutting edge."

[0054] (2) When using the first cutting edge 512 When the cutting insert 30 is attached to the first mounting seat 810 and the first cutting edge 512 is used as an actual "cutting edge," the cutting insert 30 is set in a first position with the first cutting edge 512 facing the tip side of the body 20 and fitted into the first mounting seat 810. This causes the fifth surface 120 of the cutting insert 30 to abut against the first mounting surface 811, the third surface 320 and the fourth surface 420 to abut against the second mounting surface 812 and the fourth mounting surface 814, and the second surface 210 to abut against the third mounting surface 813.

[0055] In this state, the screw 50 is inserted into the through hole 700 of the cutting insert 30 from its opening 701 and screwed into the threaded hole in the first mounting surface 811 of the first mounting seat 810. As a result, the cutting insert 30 is attached to the first mounting seat 810 of the body 20 in a first attitude in which the first cutting edge 512 is used as an actual "cutting edge."

[0056] (Attachment to the second mounting seat 820) (1) When using the second cutting edge 521 When the cutting insert 30 is attached to the second mounting seat 820 and the second cutting edge 521 is used as the actual "cutting edge," the cutting insert 30 is set in the second posture with the second cutting edge 521 facing the tip side of the body 20 and fitted into the second mounting seat 820. This causes the first surface 110 of the cutting insert 30 to abut against the first mounting surface 821, the fourth surface 420 to abut against the second mounting surface 822, and the second surface 220 to abut against the third mounting surface 823.

[0057] In this state, the screw 50 is inserted into the through hole 700 of the cutting insert 30 from its opening 702 and screwed into the threaded hole in the first mounting surface 821 of the second mounting seat 820. As a result, the cutting insert 30 is attached to the second mounting seat 820 of the body 20 in the second attitude in which the second cutting edge 521 is used as the actual "cutting edge."

[0058] (2) When using the second cutting edge 522 When the cutting insert 30 is attached to the second mounting seat 820 and the second cutting edge 522 is used as an actual "cutting edge," the cutting insert 30 is set in the second attitude with the second cutting edge 522 facing the tip side of the body 20 and fitted into the second mounting seat 820. This causes the first surface 110 of the cutting insert 30 to abut against the first mounting surface 821, the fourth surface 410 to abut against the second mounting surface 822, and the second surface 210 to abut against the third mounting surface 823.

[0059] In this state, the screw 50 is inserted into the through hole 700 of the cutting insert 30 from its opening 702 and screwed into the threaded hole in the first mounting surface 821 of the second mounting seat 820. As a result, the cutting insert 30 is attached to the second mounting seat 820 of the body 20 in the second attitude in which the second cutting edge 522 is used as the actual "cutting edge."

[0060] As described above, according to the cutting insert 30 of this embodiment, two first cutting edges 511, 512 formed along a pair of sides 111, 113 that define the substantially parallelogram-shaped first surface 110 consisting of one end face can be used, and two second cutting edges 521, 522 formed along sides 201, 203 that define the substantially trapezoidal second surfaces 210, 220 consisting of a pair of opposing side surfaces can be used. In other words, by changing the posture and orientation when attaching the cutting insert 30 to the body 20, it is possible to switch between and use a total of four cutting edges.

[0061] Furthermore, the first surface 110 of the cutting insert 30 has first rake faces 151, 152 consisting of grooves that run along the first cutting edges 511, 512. By forming the first rake faces 151, 152 consisting of grooves in the first surface 110 along the first cutting edges 511, 512 in this way, when the first cutting edges 511, 512 are used as actual cutting edges, a positive rake angle is imparted, improving sharpness and reducing cutting resistance. On the other hand, using the cutting insert 30 so that part of the first surface 110 serves as the seating surface 611 has the following advantages. That is, if seating surface 611 were located lower than first cutting edge 511 and second cutting edge 512 when viewed from above along axis AX2, first mounting surface 821 of second mounting seat 820 would have to be convex, but by configuring first rake faces 151, 152 from the grooves as described above, seating surface 611 can be the outermost surface (top surface) when viewed from above along axis AX2. As a result, there is no need to make first mounting surface 821 of second mounting seat 820 convex, and it can be made a simple flat surface, thereby reducing the manufacturing cost of body 20.

[0062] Furthermore, the through hole 700 of the cutting insert 30 has expanded diameter portions 701a, 702a that expand in diameter toward the first surface 110 and the fifth surface 120, which are end faces. Therefore, the head 50a of the screw 50 that is passed through the through hole 700 and fastened to the body 20 to fix the cutting insert 30 to the body 20 is accommodated in and engaged with the expanded diameter portions 701a, 702a. This allows the cutting insert 30 to be firmly fixed to the body 20 while minimizing the protrusion of the head 50a from the first surface 110 and the fifth surface 120, which are end faces.

[0063] Furthermore, according to the body 20 and cutting tool 10 of this embodiment, by attaching the cutting insert 30 to the first mounting seat 810 and the second mounting seat 820 of the body 20, respectively, cutting can be performed simultaneously with the first cutting edges 511, 512 of the cutting insert 30 in the first position and the second cutting edges 521, 522 of the cutting insert 30 in the second position.

[0064] In particular, since the first mounting seat 810 and the second mounting seat 820 are arranged in the front and rear sides of the body 20 along the central axis of rotation AX1, the cutting inserts 30 can be attached to the front and rear sides. This allows, for example, rough cutting to be performed with the cutting insert 30 on the front side and finish cutting to be performed with the cutting insert 30 on the rear side in a single cutting operation. Furthermore, by attaching the cutting inserts 30 to the front and rear sides, the cutting edge length of the tool as a whole can be increased, enabling it to handle high-depth cutting.

[0065] In this embodiment, the first orientation of the cutting insert 30 when attached to the first mounting seat 810 is a flat orientation in which the thickness direction of the cutting insert 30 is aligned with the rotation direction, and the second orientation of the cutting insert 30 when attached to the second mounting seat 820 is a vertical orientation in which the width direction of the cutting insert 30 is aligned with the rotation direction. As a result, in the second mounting seat 820 in which the cutting insert 30 is attached in the second orientation, which is a vertical orientation, by interposing a shim plate between the first mounting surface 821 and the cutting insert 30 and screwing it, the attachment position of the cutting insert 30 can be easily moved radially outward of the body 20. In other words, by interposing a shim plate between the first mounting surface 821 and the cutting insert 30, the tool diameter can be easily adjusted.

[0066] In this embodiment, the cutting insert 30 has a width dimension in a direction perpendicular to the second surfaces 210 and 220 that is greater than a thickness in a direction perpendicular to the first surface 110 and the fifth surface 120, which are end surfaces. For this reason, by providing the second mounting seat 820, which mounts the cutting insert 30 in the second vertical position, on the front end side of the body 20, and the first mounting seat 810, which mounts the cutting insert 30 in the first horizontal position, on the rear end side, the cutting insert 30 in the vertical position, which can have high durability, can be disposed on the front end side, which receives greater cutting resistance, thereby extending the tool life.

[0067] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise. [Explanation of symbols]

[0068] 10 cutting tools 20 Body 30 cutting inserts 110 Page 1 Areas 111 and 113 151, 152 First rake face Around 201 and 203 210, 220 2nd side 511, 512 First cutting edge 521, 522 Second cutting edge 611 Seating surface 621, 622 Second rake face 700 through holes 701a, 702a Expanded diameter part 810 First mounting seat 820 Second mounting seat

Claims

1. A cutting insert attached to a cutting tool body, comprising: a first surface having a substantially parallelogram shape, the first surface being one of a pair of end surfaces facing each other and functioning as a surface including a first rake face; a pair of first cutting edges formed along a pair of opposing sides among sides that define the first surface; a second surface having a substantially trapezoidal shape, the second surface including a pair of side surfaces facing each other and functioning as a surface including a second rake face; a second cutting edge formed along one of the sides defining each of the second surfaces; having Cutting insert.

2. The first rake face extends along the first cutting edge and includes a groove portion formed so as to be curvedly recessed in a cross section perpendicular to the extending direction. The cutting insert according to claim 1 .

3. a through hole that opens at the pair of end surfaces, The through hole has, at both ends thereof, expanded diameter portions whose diameter expands toward the end faces. The cutting insert according to claim 1 or 2.

4. A body to which a cutting insert is attached, the body having: a first surface of a substantially parallelogram shape, which is made up of one end surface of a pair of opposing end surfaces and functions as a surface including a first cutting surface; a pair of first cutting edges formed along a pair of opposing sides of the sides that define the first surface; a second surface of a substantially trapezoid shape, which is made up of a pair of opposing side surfaces and functions as a surface including a second cutting surface; and a second cutting edge formed along one side of the sides that define each of the second surfaces, a first mounting seat to which the cutting insert is attached in a first orientation in which the first cutting edge can be used as a cutting edge during cutting; a second mounting seat to which the cutting insert is attached in a second orientation in which the second cutting edge can be used as a cutting edge during cutting; having body.

5. A body rotatable around a central axis of rotation, the first mounting seat and the second mounting seat are arranged along the central axis of rotation; The body of claim 4.

6. a cutting insert having: a first surface of a substantially parallelogram shape, which is made up of one end surface of a pair of opposing end surfaces and functions as a surface including a first cutting surface; a pair of first cutting edges formed along a pair of opposing sides of the sides defining the first surface; a second surface of a substantially trapezoid shape, which is made up of a pair of opposing side surfaces and functions as a surface including a second cutting surface; and a second cutting edge formed along one of the sides defining each of the second surfaces; a body having a first mounting seat to which the cutting insert is attached in a first position in which the first cutting edge can be used as a cutting edge during cutting, and a second mounting seat to which the cutting insert is attached in a second position in which the second cutting edge can be used as a cutting edge during cutting; Equipped with cutting tools.

7. The cutting insert comprises: The first rake face includes a groove portion extending along the first cutting edge and formed so as to be curvedly recessed in a cross section perpendicular to the extending direction. The cutting tool according to claim 6.

8. The cutting insert comprises: a through hole that opens at the pair of end surfaces, The through hole has, at both ends thereof, expanded diameter portions whose diameter expands toward the end faces. The cutting tool according to claim 6 or 7.

9. the body is rotatable around a rotation center axis, The first mounting seat and the second mounting seat are arranged on the body along the central rotation axis. The cutting tool according to claim 6.

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