JP2011161537A - Cutting edge replacement type groove forming tool and end face groove forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting edge replacement type groove forming tool and an end face groove forming method capable of sufficiently securing machining accuracy, even when end face groove forming is performed along a peripheral surface of a workpiece-to-be-cut, without increasing the number of part items of a cutting insert. <P>SOLUTION: The cutting insert 30 is formed in such a way as to be rotationally symmetric with respect to an insert height-wise axis C3 and plane-symmetric with respect to an insert virtual plane VS1. An insert width-wise axis C2 is inclined in such a way that the farther the same extends in the other width direction C2A, the more closely the same gradually approaches a rear side of a rotational direction in which the workpiece-to-be-cut W rotates. The farther an insert longitudinal axis C1 extends in one extension direction C1A, the farther the insert longitudinal axis C1 gradually extends toward an upper surface side of an insert main body 31 in such a way as to approach a tool virtual plane. A corner part 43C located on an opposite side of the other width direction C2A in one cutting edge 32B is arranged on the other width direction C2A side more than a corner part 43A in the other cutting edge 32A. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a blade-exchange-type grooving tool and an end face grooving method using the same.

  Conventionally, a work piece made of a metal material or the like is rotated around the rotation axis, and is formed on the back surface (end face) of the machining hole formed around the rotation axis of the work material or the outer peripheral surface of the work material. There is known an edge-changing grooving tool in which an end face facing the rotation axis direction in the stepped portion is grooved with a cutting blade of a cutting insert. For example, a conventional cutting edge-replaceable grooving tool 100 shown in FIG. 23 is detachably mounted with a cutting insert 30 formed in a rod shape having a rectangular cross section at the tip of a shaft-shaped tool body 1. The cutting insert 30 has a pair of cutting edges 32 at both ends in the extending direction of the rod-shaped insert body 31 (left and right direction (X direction) in FIG. 23). Of these cutting edges 32, one cutting edge 32A protruding from the tip surface of the tool body 1 is grooved into the inner surface (end face) B of the machining hole H of the work material W (inner diameter side end face grooving). ). In the example of FIG. 23, the inner surface B of the work material W is orthogonal to the rotation axis WO and is formed adjacent to the inner peripheral surface (circumferential surface) S of the processing hole H, and one cutting edge 32A is The rear surface B is grooved by moving in the X direction parallel to the rotation axis WO along the inner peripheral surface S. The cutting insert 30 is rotationally symmetric with respect to an insert height axis C3 that passes through the center in the extending direction and the width direction of the insert body 31 and extends in the height direction perpendicular to the extending direction and the width direction. It is formed symmetrically with respect to an insert virtual plane (not shown) that includes the height axis C3 and is orthogonal to the extending direction, regardless of whether the specification of the tool body 1 is left-handed or right-handed. 32B can be used.

In FIG. 23, the other cutting edge 32B of the pair of cutting edges 32 is not used for cutting, and when one cutting edge 32A becomes unsuitable for use due to wear, chipping, or the like, the orientation of the insert body 31 is attached. Is inverted in the extending direction so that the cutting edge 32B protrudes from the tip surface of the tool body 1 and is used for grooving.
In this manner, the blade tip replaceable groove is formed on the inner surface (inner diameter side end surface) B which is arranged radially inward of the inner peripheral surface S in the processing hole H of the work material W and faces the rotation axis WO direction. Inner diameter side end face grooving using the insertion tool 100 is performed.

  In the example of FIG. 24, the above-mentioned cutting insert 30 is detachably attached to the tip of a blade-tip-exchangeable grooving tool 105 having an axial shape. Then, one of the cutting edges 32A protruding from the tip surface of the tool body 1 is directed to the rotation axis WO toward the end surface E facing the rotation axis WO direction in the stepped portion U of the work material W formed in a multistage columnar shape. The end face E is grooved (outer diameter side end face grooving) by moving in the X direction in parallel. In this example, the end surface E of the work material W is orthogonal to the rotation axis WO and is formed adjacent to the small diameter portion of the outer peripheral surface (circumferential surface) R, and one cutting edge 32A is formed on the small diameter portion. The grooving process is performed with respect to the end face E by moving along.

In this way, the blade tip exchange-type grooving with respect to the end surface (outer diameter side end surface) E which is arranged radially outward of the outer peripheral surface R in the small diameter portion of the work material W and faces the rotation axis WO direction. Outer diameter side end face grooving using the tool 105 is performed.
Moreover, what was described in patent document 1 is known as another cutting insert used for such a grooving process, for example.

Japanese Patent Publication No.7-115251

However, the above-mentioned blade edge replaceable grooving tools 100 and 105 have the following problems.
In the cutting insert 30, the extending direction of the insert body 31 (insert longitudinal axis C <b> 1 shown in FIGS. 23 and 24) is parallel to the rotation axis WO of the work material W, and the peripheral surface of the work material W The pair of cutting edges 32 have the same distance from the circumferential surfaces S and R. With such an arrangement of the cutting insert 30, there is no particular problem when one of the cutting edges 32A is spaced from the peripheral surfaces S, R of the work material W and grooved into the end surfaces B, E. When the blade 32A moves along the peripheral surfaces S and R of the work material W and grooving the end surfaces B and E, the other cutting blade 32B contacts the peripheral surfaces S and R and is damaged. End up. 23 and 24, the depth d1 from the end surface F located closest to the base end side of the tool body 1 to the end surface B of the machining hole H or the end surface E of the stepped portion U in the work material W, When the relationship between the distance L3 from the other cutting edge 32B to the end faces B and E is d1 <L3, there is no contact, but when d1 ≧ L3, the contact is made, so the shape of the work material W is In addition to being limited, it is conceivable that the distance L3 is reduced during the processing and the aforementioned contact occurs. When such contact occurs, not only the processing accuracy of the work material W cannot be ensured, but also the other unused cutting edge 32B is damaged. Specifically, as shown in FIGS. 25 and 26, the corner portion 43 </ b> C located on the peripheral surface S, R side of the work material W contacts the peripheral surfaces S, R in the other cutting edge 32 </ b> B. For this reason, end face grooving along the peripheral surfaces S and R of the work material W as shown in FIGS. 23 and 24 could not be performed.

  In order to prevent such contact of the cutting edge 32B with the peripheral surfaces S, R, for example, it is conceivable to change the posture of the cutting insert 30 attached to the tool body 1. That is, as shown in FIGS. 27 and 28, when viewed from the rake face 33 side (the upper surface side of the insert main body 31) of the cutting insert 30, the insert longitudinal axis C1 of the insert main body 31 is from one cutting edge 32A side to the other. The cutting insert 30 may be attached to the tool body 1 with the cutting insert 30 inclined with respect to the X direction so as to gradually move away from the peripheral surface S (R) of the work material W as it goes toward the cutting edge 32B. Thereby, since the corner portion 43C disposed on the peripheral surface S (R) side of the other cutting edge 32B in the cutting insert 30 is disposed apart from the peripheral surface S (R), the contact described above is performed. Is prevented.

  However, in this case, if attention is paid to one of the cutting edges 32A, as shown in FIG. 28, the front cutting edge 41 of the cutting edge 32A is in the drawing with respect to the work material virtual plane VS4 perpendicular to the rotation axis WO. It is inclined by an angle α. Originally, the groove bottom D of the groove formed by grooving is required to be perpendicular to the rotation axis WO (that is, parallel to the work material virtual plane VS4). By being inclined, the groove bottom D of the cut groove is also inclined by the angle α with respect to the work material virtual plane VS4, and sufficient machining accuracy cannot be ensured.

  On the other hand, in the cutting insert described in Patent Document 1, while the cutting insert is formed rotationally symmetrical with respect to the insert height axis, it is not formed plane-symmetrically with respect to the insert virtual plane, It is formed to be twisted as a whole. Thus, when the cutting insert is mounted on the tool body, the corner portion on the peripheral surface S (R) side of the other cutting edge is more circumferential than the corner portion on the peripheral surface S (R) side of the one cutting edge. The surface is separated from the surface S (R). However, in this case, left-handed and right-handed cutting inserts must be prepared in accordance with the specifications of the tool body, which increases the number of parts and makes management complicated.

  The present invention has been made in view of such circumstances, and even when end face grooving is performed along the peripheral surface of the work material without increasing the number of parts of the cutting insert, the processing accuracy is improved. It is an object of the present invention to provide a blade replacement type grooving tool and an end face grooving method capable of sufficiently ensuring the above.

In order to achieve the above object, the present invention proposes the following means.
That is, the present invention relates to a cutting insert having a cutting edge protruding toward an end face of a work material that rotates about a rotation axis, and a tool body that has a shaft shape and is detachably attached to the tip portion. And a cutting edge replaceable grooving tool for grooving the end face with the cutting edge, wherein the cutting insert is an upper surface of the insert body at both ends in the extending direction of the rod-shaped insert body. A pair of cutting edges, and rotationally symmetric with respect to the insert height axis passing through the center in the extending direction of the insert body and the center in the width direction orthogonal to the extending direction, and orthogonal to the extending direction and the width direction, and The insert blade is formed in plane symmetry with respect to an imaginary virtual plane including the insert height axis and perpendicular to the extending direction, and the cutting edge is formed at an end edge of the insert body in the extending direction. A front cutting edge extending along the width direction, a pair of corner portions disposed at both ends of the front cutting edge and projecting in the width direction, and a center of the insert body along the extending direction from the corner portion A pair of side cutting edges extending so as to gradually narrow each other toward the side, and the tool body is arranged so that the cutting insert is along one side faced to the side of the tool body. And one cutting edge of the pair of cutting edges protrudes in the grooving direction from the distal end surface of the distal end portion toward the distal end side, and the cutting insert is centered in the extending direction of the insert body. An insert width axis along the width direction passes through one corner portion located on one side of the tool body in the pair of corner portions in the width direction, and the other corner The insert is inclined toward the rear side in the rotational direction in which the work material rotates gradually toward the other width direction, which is the direction toward the part, and passes through the center in the width direction of the insert body and extends along the extending direction. The longitudinal axis is inclined with respect to the virtual tool plane including the one corner portion of the one cutting edge and the rotation axis, and from the other cutting edge of the pair of cutting edges in the extending direction. As it goes to one extending direction that is a direction toward the one cutting edge, it gradually extends toward the upper surface side of the insert body so as to approach the tool virtual plane, One corner portion located on the opposite side to the width direction is arranged on the other width direction side with respect to the one corner portion of the one cutting edge. To do.
The present invention also provides a cutting insert having a cutting edge protruding toward an end face of a work material that rotates about a rotation axis, and a tool body that has a shaft shape and is detachably attached to the tip portion. And an edge face grooving method for grooving the end face of the work material with the cutting edge using a cutting edge exchange grooving tool, wherein the cutting insert is an extension of a rod-shaped insert body. A pair of cutting blades are provided on the upper surface of the insert main body at both ends in the existing direction, passing through the center in the extending direction of the insert main body and the center in the width direction orthogonal to the extending direction in the extending direction and the width direction. The insert blade is formed rotationally symmetric with respect to an orthogonal insert height axis, and symmetrical with respect to an insert virtual plane that includes the insert height axis and is perpendicular to the extending direction. A front cutting edge that is formed at an edge in the extending direction of the front edge and extends along the width direction, a pair of corner portions that are arranged at both ends of the front cutting edge and project in the width direction, and the corner portion. A pair of side cutting edges each extending so as to gradually narrow the distance from each other toward the center side of the insert body along the extending direction, and the cutting insert is directed to the side of the tool body. The cutting blade is disposed along the side surface, and one of the pair of cutting blades protrudes from the tip surface of the tip portion toward the tip side in the grooving direction and is attached to the tool body. When grooving the end face by moving the cutting edge along the grooving direction, the insert width axis along the width direction passing through the center in the extending direction of the insert body, Rotation direction in which the work material gradually rotates as it goes in the other width direction from one corner portion located on one side of the tool body in the pair of corner portions to the other corner portion. The insert longitudinal axis extending along the extending direction through the center in the width direction of the insert main body is made into a virtual tool plane including one corner portion of the one cutting edge and the rotation axis. In addition, the tool imaginary plane gradually approaches the one extending direction that is the direction from the other cutting edge of the pair of cutting edges toward the one cutting edge in the extending direction. Extending one side toward the upper surface side of the insert body, and one corner portion located on the opposite side of the other width direction in the other cutting edge The one cutting edge is disposed on the other width direction side of the one corner portion.

  According to the cutting edge replaceable grooving tool and the end face grooving method according to the present invention, the front cutting edge in one cutting edge of the cutting insert protruding from the tip of the tool body toward the end face of the work material, Since it gradually inclines toward the rear side in the rotational direction of rotation of the work material as it goes in the other width direction so as to be parallel to the insert width axis, the cutting resistance when the tool body is laterally fed is To reduce.

  That is, in general, when traversing the tool body, in the case of the inner diameter side end face grooving, it is moved from the inner peripheral surface of the work material toward the rotation axis side, and in the case of the outer diameter side end face grooving process. It is moved from the outer peripheral surface of the work material toward the side opposite to the rotation axis. At this time, the other corner portion and the side surface cutting edge located on the moving direction side of the one cutting edge of the cutting insert cut sharply with respect to the work material, so that the cutting resistance is reduced.

In addition, in the case of grooving on the inner diameter side end face, the component force of the cutting resistance generated during grooving acts from one side where the cutting insert is arranged in the tool body toward the center side of the tool body. The cutting process is stable and the processing accuracy is ensured.
Further, in the case of performing the outer diameter side end face grooving, the front cutting edge of one of the cutting edges is set as described above, whereby the cutting can be performed stably with higher accuracy. Specifically, when the cutting edge exchange type grooving tool is mounted on a machine tool or the like, at least the other side surface of the tool body facing the side opposite to the one side surface is in contact with the machine tool or the like. The The front cutting edge of one cutting edge of the cutting insert is inclined toward the rear side in the rotational direction in which the work material rotates gradually toward the other width direction, so that the cutting edge receives during grooving. The component force of the cutting force acts to press the other side of the tool body against a machine tool or the like. This stabilizes the position of the cutting edge exchange-type grooving tool with respect to the machine tool or the like at the time of cutting, and allows highly accurate cutting to be performed stably.

  Further, the insert longitudinal axis of the cutting insert is inclined so as to gradually approach the virtual tool plane as it goes in the one extending direction, and extends toward the upper surface side of the insert body. That is, since the other cutting edge is spaced toward the lower surface side of the insert body with respect to the tool virtual plane, one cutting edge cuts sharply with respect to the end surface of the work material, and the sharpness is reduced. It can be raised enough.

In addition, one corner portion located on the opposite side to the other width direction in the other cutting edge is opposite to the one corner portion located on the opposite side in the one cutting edge in the other width direction side. Is arranged. Thereby, for example, grooving (inner diameter side end face grooving) in the back surface (end face) of the processed hole along the inner peripheral surface of the cylindrical hole-shaped processed hole formed around the rotation axis of the work material When it does, there exist the following effects. That is, for example, one corner portion of one cutting edge of the cutting insert is disposed close to the inner peripheral surface of the work material, and the cutting insert is moved in the grooving direction along the inner peripheral surface. When grooving, one corner portion of the other cutting edge is separated from the inner peripheral surface, and this corner portion is reliably prevented from coming into contact with and scratching the inner peripheral surface. The Further, for example, in the step portion of the work material having a multistage cylindrical shape, grooving processing (outer diameter side end face grooving) is performed on the end surface of the work material along the small diameter portion having the outer peripheral surface parallel to the rotation axis. In this case, the same effect as described above can be obtained. That is, for example, one corner portion of one cutting edge of the cutting insert is disposed close to the outer peripheral surface of the small-diameter portion of the work material, and the cutting insert is grooved along the small-diameter portion. When the grooving process is performed by moving to one, the corner portion of the other cutting edge is separated from the small diameter portion, and the corner portion is prevented from coming into contact with the small diameter portion and being damaged.
Further, the above-described contact prevents the other unused cutting edge from being damaged.

  Further, regardless of the depths d1 of the end faces B and E of the work material W described in FIGS. 23 and 24, one corner portion of the other cutting edge is separated from the peripheral surface of the work material, and this corner portion. Is reliably prevented from coming into contact with the peripheral surface and being damaged.

  Further, when attention is paid to the groove bottom of the work material to be cut by one of the cutting edges, the insert width axis of the cutting insert is gradually inclined toward the rear side in the rotational direction in which the work material rotates as it goes to the other width direction. And the insert longitudinal axis is inclined toward the upper surface side of the insert body so as to approach the tool virtual plane as it goes in the one extending direction, and one corner portion of the other cutting edge The groove bottom is formed with an inclination close to perpendicular to the rotation axis of the work material by being arranged on the other width direction side of the one corner portion of the cutting edge. That is, the angle α of the groove bottom D described with reference to FIG. 28 is formed to be relatively small, and the machining accuracy of the groove cut into the work material is increased.

  In addition, since the pair of side surface cutting blades provided in each cutting edge are formed to be inclined so as to gradually narrow each other from the outside in the extending direction of the insert body toward the center side, the processing of the groove wall Accuracy is ensured. That is, even if the mounting posture of the cutting insert with respect to the tool body is set as described above, the side surface disposed on the side opposite to the peripheral surface side of the work material (that is, the other width direction side) in one of the cutting edges The cutting edge does not come into contact with the opening edge of the groove wall on the opposite side of the groove formed in the work material.

  Further, in the cutting edge-replaceable grooving tool according to the present invention, when the cutting insert is viewed from a direction orthogonal to the tool virtual plane, an angle θ1 formed by the insert width axis and the rotation axis is 90 ° ≦ θ1 ≦. It may be set to 90.5 °.

  According to the cutting edge-replaceable grooving tool according to the present invention, for example, when the peripheral surface of the work material is formed parallel to the rotation axis, the extending direction of the insert body is relative to the peripheral surface of the work material. The tilt angle is set to a value slightly larger than (θ1-90 °) while approximating the value obtained by subtracting 90 ° from the angle θ1 formed by the insert width axis and the rotation axis (that is, θ1-90 °). Is done. That is, the cutting insert is mounted on the tool body so that the extending direction (insert longitudinal axis) of the insert body is substantially parallel to the cutting body while being slightly inclined with respect to the peripheral surface of the work material. Therefore, as described above, one corner portion of the other cutting edge is surely separated from the peripheral surface to ensure the processing accuracy of the peripheral surface, while the groove bottom of the groove formed on the end surface of the work material is Processing accuracy can be secured. Specifically, by setting the angle θ1 within the aforementioned range, the groove bottom of the grooved work material is formed substantially perpendicular to the rotation axis, so that the machining accuracy of the groove bottom is increased. Yes.

  Further, in the cutting edge replaceable grooving tool according to the present invention, the end surface is a back surface facing the base end side of the tool body in a machining hole formed in the work material, and the one cutting edge is It is good also as carrying out an inner diameter side end surface grooving process with respect to a back surface.

  According to the cutting edge exchange type grooving tool according to the present invention, an inner peripheral surface parallel to the rotation axis is formed adjacent to the inner surface of a machining hole formed in a work material, for example, having a cylindrical hole shape. Even in this case, the inner diameter side end face grooving can be performed with high accuracy regardless of the position of the inner surface to be grooved.

  Further, in the cutting edge replaceable grooving tool according to the present invention, the end surface is an end surface facing the base end side of the tool body in a step formed on the outer peripheral surface of the work material, and the one cutting edge is The outer diameter side end face grooving may be performed on the end face.

  According to the cutting edge exchange type grooving tool according to the present invention, for example, the outer peripheral surface parallel to the rotation axis is adjacent to the end surface facing the base end side of the tool body in the step portion of the work material having a multi-stage cylindrical shape. Even in the case where the small diameter portion is formed, the outer diameter side end face grooving with high accuracy can be performed regardless of the position of the end face to be grooved.

  Moreover, the blade edge exchange-type grooving tool which concerns on this invention WHEREIN: The said pair of corner part in said one cutting edge is good also as arrange | positioning on the work material virtual plane perpendicular | vertical to the said rotation axis.

  According to the cutting edge-replaceable grooving tool of the present invention, the pair of corner portions of one of the cutting edges is disposed on the work material virtual plane perpendicular to the rotation axis of the work material. The groove bottom of the work material to be cut with the blade can be formed perpendicular to the rotation axis. Therefore, the finishing accuracy of the groove of the work material is sufficiently ensured.

  Further, in the edge-changing grooving tool according to the present invention, the corner portion has a convex-curved first corner blade, and the one corner portion of the one cutting edge is adjacent to the corner portion. An intersection of the extension line of the front cutting edge and the perpendicular line extending from the outer edge portion in the width direction of the first corner edge toward the extension line may be disposed on the tool virtual plane.

  According to the cutting edge exchange-type grooving tool according to the present invention, the corner portion of the cutting edge has the first curved corner portion having a convex curve, so that the cutting edge is not damaged at the corner portion.

  Further, in the cutting edge replaceable grooving tool according to the present invention, the corner portion is a linear first connecting the end portion on the center side in the extending direction of the insert body in the first corner blade and the side face cutting blade. The second corner blade has a two-corner blade and extends so as to be parallel to the rotation axis of the work material when the cutting insert is viewed from a direction orthogonal to the tool virtual plane. Also good.

  According to the cutting edge-replaceable grooving tool according to the present invention, the corner portion of the cutting edge has a second corner that connects the end portion on the center side along the extending direction of the insert body in the first corner blade and the side cutting edge. Since the blade extends so as to be parallel to the rotation axis of the work material, the front edge of one of the work blades and the groove wall of the work material cut by the first corner blade are used as the second corner blade. As a result, the finishing accuracy of the groove wall is increased.

  According to the cutting edge replaceable grooving tool and the end face grooving method according to the present invention, even when the end face grooving is performed along the peripheral surface of the work material without increasing the number of parts of the cutting insert. Sufficient machining accuracy can be secured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing a cutting edge replaceable grooving tool according to a first embodiment of the present invention and a work material to be subjected to grooving using this cutting edge replaceable grooving tool. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing a cutting edge replaceable grooving tool according to a first embodiment of the present invention and a work material to be subjected to grooving using this cutting edge replaceable grooving tool. It is the top view which looked at the cutting edge exchange type grooving tool and work material which concern on the 1st Embodiment of this invention from the direction which opposes the rake face of a cutting insert, and is the figure which looked at the cutting insert from the upper surface. is there. It is a schematic side view which shows the blade-tip-exchange-type grooving tool and work material which concern on the 1st Embodiment of this invention. It is the front view which looked at the blade-tip-exchange-type grooving tool which concerns on the 1st Embodiment of this invention from the front end side of the tool main body. It is a perspective view which shows the cutting insert. It is a figure which expands and shows one cutting edge 32A of the cutting insert in FIG. It is a figure which expands and shows the cutting insert 30 vicinity in FIG. It is a figure which expands and shows the other cutting edge 32B of the cutting insert in FIG. It is a figure which expands and shows the cutting insert 30 vicinity in FIG. It is a figure which shows the mounting | wearing attitude | position of the cutting insert 30, and the virtual circle VC1 which rotated the corner part 43A around the rotation axis WO, and the virtual circle VC2 which rotated the corner part 43B around the rotation axis WO. It is a schematic perspective view which shows the cutting edge exchange-type grooving tool which concerns on the 2nd Embodiment of this invention, and the workpiece which performs grooving using this cutting-edge exchange-type grooving tool. It is the top view which looked at the cutting-blade exchange type grooving tool and work material which concern on the 2nd Embodiment of this invention from the direction which opposes the rake face of a cutting insert, and is the figure which looked at the cutting insert from the upper surface. is there. It is a schematic side view which shows the blade-tip-exchange-type grooving tool and work material which concern on the 2nd Embodiment of this invention. It is the front view which looked at the blade-tip-exchange-type grooving tool which concerns on the 2nd Embodiment of this invention from the front end side of the tool main body. It is a perspective view which shows the cutting insert. It is a figure which expands and shows one cutting edge 32A of the cutting insert in FIG. It is a figure which expands and shows the cutting insert 30 vicinity in FIG. It is a figure which expands and shows the cutting insert 30 vicinity in FIG. It is a figure which shows the mounting | wearing attitude | position of the cutting insert 30, and the virtual circle VC1 which rotated the corner part 43A around the rotation axis WO, and the virtual circle VC2 which rotated the corner part 43B around the rotation axis WO. It is a figure which shows the modification of the corner part in the cutting blade of a cutting insert. It is a figure which shows the modification of the corner part in the cutting blade of a cutting insert. It is the top view which looked at the conventional cutting edge exchange-type grooving tool (inner diameter side end surface grooving) and the work material from the direction which opposes the rake face of a cutting insert, and is the figure which looked at the cutting insert from the upper surface. . It is the top view which looked at the conventional cutting edge exchange type grooving tool (outer diameter side end face grooving) and the work material from the direction which faces the rake face of the cutting insert, and is the figure which looked at the cutting insert from the upper surface. is there. It is a figure which expands and shows the A1 part in FIG. It is a figure which expands and shows the A2 part in FIG. It is the top view which looked at the conventional cutting edge exchange type grooving tool and work material from the direction which opposes the rake face of a cutting insert, and is the figure which looked at the cutting insert from the upper surface. It is a figure which expands and shows the cutting insert 30 and the groove bottom D in FIG.

(First embodiment)
FIGS. 1 to 11 show a cutting edge replacement grooving tool 10 according to a first embodiment of the present invention and a cutting insert 30 used in the cutting edge replacement grooving tool 10. The cutting edge-replaceable grooving tool 10 according to the present embodiment is formed in a shaft shape, a tool body 1 having a substantially circular cross section perpendicular to the center axis TO, and a tip side of the tool body 1 along the center axis TO And a cutting insert 30 that is detachably attached to the end portion (tip portion) 3 of the tool body 1 and projects a cutting edge 32 from the tip surface 1A of the tool body 1 toward the tip side.

  The cutting edge exchange-type grooving tool 10 of this embodiment performs an inner diameter side end surface grooving process on a substantially cylindrical work material W. An inner peripheral surface (peripheral surface) S that faces the rotation axis WO side of the workpiece W and is parallel to the rotation axis WO is formed in the processing hole H that forms a cylindrical hole shape in the workpiece W. This inner peripheral surface S is located at the innermost portion of the processing hole H and is adjacent to a rear surface (end surface) B formed of a circular plane orthogonal to the rotation axis WO. The cutting edge-replaceable grooving tool 10 is a work that rotates in the rotation direction WT about the rotation axis WO while the center axis TO of the tool body 1 is arranged substantially parallel to the rotation axis WO of the workpiece W. In the material W, the tip 3 of the tool body 1 is inserted into a machining hole H formed around the rotation axis WO, and the cutting edge 32 is moved along the inner peripheral surface S. Surface B is cut. In the present embodiment, symbols X, Y, and Z indicating directions are used in some of the drawings. Here, symbols X and Y respectively indicate horizontal directions. Specifically, the X direction indicates the horizontal direction parallel to the rotation axis WO of the work material W, and the Y direction indicates the horizontal direction perpendicular to the rotation axis WO. Show. Moreover, the code | symbol Z has shown the perpendicular direction.

  The tool body 1 is made of a steel material or the like, and a central portion and a base end portion other than the distal end portion 3 along the central axis line TO form a shank portion 2 having a substantially constant outer diameter. In the region located on the shank portion 2 on the outer peripheral surface of the tool body 1, the central axis TO is sandwiched in the vertical direction (Z direction), and is formed of a belt-like plane extending in parallel to the central axis TO, and is disposed so as to face each other. An upper surface 2A and a lower surface 2B are formed. The cutting edge exchange type grooving tool 10 is fixedly supported by a machine tool (not shown) by holding the shank portion 2 while being prevented from rotating by the upper surface 2A and the lower surface 2B. In the present embodiment, the central axis TO extends in the X direction, and the upper surface 2A and the lower surface 2B are arranged in the XY horizontal plane. In the following description, the distal end side (left side in the left-right direction (X direction) in FIG. 3) of the tool body 1 may be referred to as one side, and the proximal end side (right side in the X direction in FIG. 3) may be referred to as the other side.

  The distal end portion 3 of the tool body 1 has a substantially trapezoidal shape in a plan view of FIG. 3, and an upper jaw portion 6 and a lower jaw portion 7 are formed protruding from the distal end surface 1A toward the distal end side. The upper jaw portion 6 and the lower jaw portion 7 of the distal end portion 3 are opposed to each other in the vertical direction (Z direction), and in the distal end surface 1A, the direction perpendicular to the rotation axis WO (Y direction in FIG. 3) It is formed at the end of one side (the lower side in FIG. 3). Further, as shown in FIG. 4, the upper surface 3 </ b> A of the tip portion 3 is formed so as to be recessed by one step from the upper surface 2 </ b> A of the shank portion 2. Further, the lower surface 3 </ b> B at the distal end portion 3 of the tool body 1 is flush with the lower surface 2 </ b> B of the shank portion 2.

  Further, the tool body 1 has a side surface 3C facing one side among the both side surfaces facing the side (Y direction in FIG. 3) at the tip portion 3 thereof, and the side surface (one side surface) facing the one side in the shank portion 2. ) It is flush with 2C and forms side surfaces facing the one side of the upper jaw portion 6 and the lower jaw portion 7. A central portion in the Z direction on one side surface 3C of the tip portion 3 and one side surface 2C of the shank portion 2 is formed in a belt-like plane that is perpendicular to the upper surface 2A and the lower surface 2B and extends along the central axis TO.

  Further, the distal end portion 3 is formed with another side surface 3D which is disposed so as to face the other side (upper side in FIG. 3) of the both side surfaces and to face the one side surface 3C. The other side surface 3D of the distal end portion 3 is formed in a tapered shape so as to be gradually inclined toward the one side from the proximal end side of the tool body 1 toward the distal end side. In addition, the base end portion of the other side surface 3D is connected to the side surface (other side surface) 2D having a convex cross-sectional shape facing the other side in the shank portion 2. In addition, the shape of the shank part 2 and the front-end | tip part 3 of the tool main body 1 mentioned above is an example, and is not limited to this embodiment. For example, the shapes of the one side surfaces 3C and 2C are not limited to the above-described plane, and may be other curved surfaces or uneven shapes. Further, the side surfaces 3C and 2C do not have to be flush with each other. For example, in the plan view of FIG. 3, the one side surface 2C of the shank portion 2 is illustrated in the Y direction illustrated with respect to the one side surface 3C of the tip portion 3. It may be formed to protrude downward or to be recessed upward in the Y direction.

  In the side view of FIG. 4, the upper jaw portion 6 has a substantially triangular shape, and the upper surface of the upper jaw portion 6 is formed so as to be gradually inclined toward the lower surface 3 </ b> B side from the proximal end side toward the distal end side. Further, in the front view of FIG. 5, the lower jaw portion 7 has a concave curved surface on the surface facing the rotational axis WO, and a convex curved surface on the surface facing the rotational axis WO. The whole is formed in a substantially arcuate shape. As shown in FIG. 5, the thickness of the lower jaw 7 is formed so as to gradually become thinner from the upper surface 3A side toward the lower surface 3B side. Specifically, in this front view, the lower jaw portion 7 is arranged to correspond to the lower side portion in the Z direction on one side surface 2C of the shank portion 2 and one side surface 3C of the tip portion 3, and from the upper side to the lower side. As it goes, it is gradually curved toward the other side surface 3D. Further, in the side view of FIG. 4, the lower jaw portion 7 has a substantially rectangular shape, and protrudes from the upper jaw portion 6 toward the distal end side of the tool body 1.

  In addition, a gap is provided between the upper jaw portion 6 and the lower jaw portion 7 so as to be an insert mounting seat 4 on which the cutting insert 30 is detachably mounted. The tool body 1 has a cutting insert 30 mounted on the insert mounting seat 4, and the cutting insert 30 is disposed along the side surfaces 3 </ b> C and 2 </ b> C facing the side of the tool body 1. Specifically, the cutting insert 30 is substantially parallel to the central axis TO when mounted on the insert mounting seat 4 opened on one side surface 3C of the tip 3 of the tool body 1 in the plan view of FIG. It extends and is disposed along the one side surface 3C in a state where a corner portion 43C of a cutting edge 32B described later is slightly protruded from the one side surface 3C toward the lower side in the Y direction.

  The insert mounting seat 4 has a substantially rectangular parallelepiped hole shape, is located on the side surface 3C side of the tip portion 3, and extends along the X direction. The insert mounting seat 4 has a distal end portion and a central portion located between the upper jaw portion 6 and the lower jaw portion 7 and opened on both sides in the Y direction. Moreover, the front-end | tip part of the insert mounting seat 4 is opened also in the direction (grooving direction XA mentioned later) which faces a front end side among X directions. Further, the base end portion of the insert mounting seat 4 is located between the upper surface 3A and the lower surface 3B and is open to the one side surface 3C. In the side view of FIG. 4, the insert mounting seat 4 is formed so as to be gradually inclined from the lower surface 3 </ b> B toward the upper surface 3 </ b> A as it goes from the proximal end side to the distal end side of the tool body 1. In addition, a stepped portion 4 </ b> A facing the distal end side of the tool body 1 is formed at the base end portion of the insert mounting seat 4.

  Further, on the base end side of the insert mounting seat 4, a tightening portion 8 is formed which has a slit shape narrower than the insert mounting seat 4 and opens to the front end surface 1A, one side surface 3C and the other side surface 3D. . The tightening portion 8 is formed so as to be gradually inclined from the lower surface 3B toward the upper surface 3A as it goes from the proximal end side to the distal end side of the tool body 1.

  Further, the top wall surface 4B and the bottom wall surface 4C facing the top and bottom in the insert mounting seat 4 are each formed in a convex V shape when viewed from the front end surface 1A side, as shown in FIGS. Further, as shown in FIG. 4, the tightening portion 8 is formed so that the space between the top wall surface 4 </ b> D and the bottom wall surface 4 </ b> E is narrow with respect to the insert mounting seat 4. A through-hole 5A is formed in the top wall surface 4D of the tightening portion 8 so as to open to the upper surface 3A of the distal end portion 3 and through which the clamp screw 5 is inserted. The bottom wall surface 4E of the tightening portion 8 is formed with a screw hole (not shown) that is coaxial with the through hole 5A and is subjected to female threading on the inner peripheral surface.

  Further, the cutting insert 30 to be mounted on the blade exchange type grooving tool 10 is made of a hard material such as cemented carbide, and as shown in FIG. 4, the extending direction of the rod-shaped insert body 31 (in FIG. 4). This is a so-called dogbone type cutting insert provided with a pair of cutting edges 32 on the upper surface of the insert main body 31 (the surface facing the upper side in the Z direction in FIG. 4) at both ends in the left-right direction (X direction).

  6 to 9 indicate the insert longitudinal axis along the extending direction of the insert body 31, and the insert longitudinal axis C1 is orthogonal to the extending direction in the insert body 31. While passing through the center in the width direction, the pair of cutting edges 32 extend through the center of front cutting edges 41 and 41, which will be described later. Further, symbol C2 indicates an insert width axis along the width direction of the insert body 31, and the insert width axis C2 is the center of the insert body 31 along the insert longitudinal axis C1 (part indicated by a double circle in the drawing). ), And extends in parallel to the front cutting edge 41 while being orthogonal to the insert longitudinal axis C1. Reference symbol C3 indicates an insert height axis along the height direction of the insert main body 31, and the insert height axis C3 passes through the center of the insert main body 31, and the insert longitudinal axis C1 and the insert width axis C2. Extend in directions orthogonal to each other.

  The cutting insert 30 is formed symmetrically (that is, plane-symmetric) with respect to the insert virtual plane VS1 that passes through the center of the insert body 31 along the insert longitudinal axis C1 and is perpendicular to the insert longitudinal axis C1. The cutting insert 30 includes an insert longitudinal axis C1 and an insert height axis C3, and an upper surface (a surface facing upward in the vertical direction (Z direction) in FIG. 5) and a lower surface (Z direction in FIG. 5). The imaginary insert imaginary plane VS2 passing through the center of each of the surfaces is also symmetrical (plane symmetry). That is, the cutting insert 30 is formed rotationally symmetric with respect to the insert height axis C3. The cutting insert 30 may not be formed symmetrically with respect to the insert virtual plane VS2.

  As shown in FIGS. 6 and 10, the cutting insert 30 has a concave V-shaped cross section in which the central portion in the extending direction and the lower surface of the upper surface of the insert body 31 are perpendicular to the insert longitudinal axis C <b> 1. Is formed. With such a shape of the insert main body 31, the cutting insert 30 is guided so as to be in sliding contact with the top wall surface 4B and the bottom wall surface 4C at the portion where the insert mounting seat 4 opens to the tip side, and from the one side to the other side. Inserted.

  As shown in FIG. 4, the cutting insert 30 inserted into the insert mounting seat 4 is positioned with the other end face of the insert body 31 abutting against the stepped portion 4 </ b> A. By tightening the clamp screw 5 in this state, the top wall surface 4D of the tightening portion 8 approaches while being elastically deformed toward the bottom wall surface 4E, and the top wall surface 4B of the insert mounting seat 4 is elastically deformed toward the bottom wall surface 4C. While approaching. Thus, the space | interval of top wall surface 4D, 4B and bottom wall surface 4E, 4C is narrowed, and the cutting insert 30 is fixedly supported by the front-end | tip part 3 of the tool main body 1. FIG.

  In addition, a pair of cutting edges 32 are disposed at both ends along the insert longitudinal axis C <b> 1 direction on the upper surface of the insert body 31. As shown in FIG. 8, the cutting edge 32 is a linear front cutting edge that is formed at the edge in the extending direction of the insert body 31 and extends in the width direction (left-right direction in FIG. 8) perpendicular to the extending direction. 41, a pair of corner portions 43 disposed at both ends of the front cutting edge 41 and projecting in the width direction, and the center side (inside) of the insert main body 31 along the extending direction from these corner portions 43 A pair of side-faced cutting edges 42 each extending linearly so as to gradually narrow the distance from each other as it goes to.

  Specifically, the pair of side surface cutting edges 42 are formed so as to be inclined from the outer side in the width direction toward the central side (inner side) gradually from the outer side in the extending direction of the insert body 31 toward the central side. A back taper is given.

  Further, the both end portions on the upper surface of the insert main body 31 are made to recede by one step from the central portion and have a substantially square shape, respectively, and form a pair of rake surfaces 33. The rake face 33 has a front cutting edge 41 and a pair of side cutting edges 42 on its outer peripheral edge other than the central side in the extending direction.

  Further, in FIG. 6, the peripheral surface connecting the upper surface and the lower surface of the outer surface of the insert body 31 has a front flank 51 connected to the front cutting edge 41 and a pair of side flank surfaces connected to a pair of side cutting edges 42. 52 is formed. The front flank 51 is formed to be inclined so as to gradually recede from the outer surface of the insert body 31 as it goes from the front cutting edge 41 toward the lower surface. Further, the side flank 52 is formed to be inclined so as to gradually recede from the outer surface of the insert body 31 as it goes from the side cutting edge 42 to the lower surface side. In the following description, the surface of the insert body 31 on which the front clearance surface 51 is formed is referred to as the front surface of the cutting insert 30, and the surface of the insert body 31 on which the side clearance surface 52 is formed is referred to as the side surface of the cutting insert 30.

  When the cutting insert 30 is mounted on the insert mounting seat 4 of the tool body 1, as shown in FIG. 3, the cutting edge 32A is arranged on the one side (left side in the X direction in FIG. 3) of the pair of cutting edges 32. The cutting edge 32B is arranged on the other side (the right side in the X direction in FIG. 3). One cutting edge 32A protrudes from the tip surface 1A of the tip 3 of the tool body 1 toward the tip side and is disposed opposite to the back surface B of the work material W, and is grooved in the back surface B. It is designed to be processed. Specifically, the tool body 1 projects one cutting edge 32A of the pair of cutting edges 32 from the distal end surface 1A of the distal end portion 3 toward the grooving direction indicated by the symbol XA in the X direction, A cutting insert 30 is attached.

  3 and 5 to 8, the direction indicated by C2A is the tool body 1 in the pair of corner portions 43A and 43B (43C and 43D) in the width direction of the insert body 31 (in the direction of the insert width axis C2). From one corner portion 43A (43C) located on the side surface 2C, 3C side of the workpiece W and located on the inner circumferential surface S side of the work material W, it is located on the other side surface 2D, 3D side of the tool body 1 and the inner circumference. The other width direction, which is a direction toward the other corner portion 43B (43D) located on the opposite side to the surface S side, is shown. As shown in the front view of FIG. 10, the insert width axis C2 of the cutting insert 30 is gradually inclined toward the rear side in the rotational direction WT of the workpiece W as it goes to the other width direction C2A.

  That is, in this cutting insert 30, the front cutting edge 41 of one cutting edge 32A is gradually inclined toward the rear side in the rotation direction WT of the work material W as it goes to the other width direction C2A. Specifically, as shown in FIG. 5, the cutting insert 30 gradually moves toward the rear side in the rotational direction WT as the front cutting edge 41 of the cutting edge 32 </ b> A goes from the one side surface 3 </ b> C side to the other side surface 3 </ b> D side. At the same time, the tool body 1 is inclined toward the upper surface 3A. In addition, by this, in one cutting edge 32A, the corner portion 43B located on the other width direction C2A side of the pair of corner portions 43A and 43B has a rotational direction WT of the work material W with respect to the corner portion 43A. It is arranged on the rear side.

  In the present embodiment, the front cutting edge 41 of the cutting edge 32A is gradually inclined toward the rear side in the rotation direction WT of the work material W as it is separated from the inner peripheral surface S toward the rotation axis WO. Here, what is indicated by reference sign VS3 in FIGS. 4, 5, and 10 represents a virtual tool plane including the corner portion 43A of the cutting edge 32A and the rotation axis WO. In FIG. 10, the angle θ2 formed by the front cutting edge 41 of the cutting edge 32A and the tool virtual plane VS3 is set within a range of 0 ° <θ2 ≦ 7 °. In the present embodiment, this θ2 is set to about 3 °, for example. Further, since the insert width axis C2 is parallel to the front cutting edge 41, it can be said that the angle θ2 is an angle formed by the insert width axis C2 and the tool virtual plane VS3. In the present embodiment, the tool virtual plane VS3 is arranged in the XY horizontal plane.

  3 and FIG. 4, the direction indicated by the reference symbol C1A is one cutting edge from the other cutting edge 32B of the pair of cutting edges 32A and 32B in the extending direction of the insert body 31 (in the direction of the insert longitudinal axis C1). One extending direction which is a direction toward 32A is shown. As shown in FIG. 4, when viewed from one side 3C side of the tool body 1, the insert longitudinal axis C1 of the cutting insert 30 is inclined so as to gradually approach the tool virtual plane VS3 toward the one extending direction C1A. Has been.

  Specifically, in the side view of FIG. 4, the insert longitudinal axis C <b> 1 gradually increases from the lower surface side of the insert body 31 toward the one extending direction C <b> 1 </ b> A (the lower side in the vertical direction (Z direction) in FIG. 4). It extends so as to approach the tool virtual plane VS3 (upper side in the Z direction in FIG. 4). Thereby, the front cutting edge 41 of the cutting edge 32B is separated toward the lower surface side of the insert main body 31 with respect to the tool virtual plane VS3. The angle θ3 formed by the insert longitudinal axis C1 and the tool virtual plane VS3 is set within a range of 0 ° <θ3 ≦ 10 °. In the present embodiment, this θ3 is set to about 3 °, for example.

  As shown in FIG. 4, the cutting insert 30 attached to the tool body 1 is moved in the one extending direction C1A from the other side where the cutting edge 32B is arranged to the one side where the cutting edge 32A is arranged. As it goes, it is arranged so as to be gradually inclined toward the upper surface 3A of the tool body 1.

  3 and 8 are top views of the cutting insert 30 viewed from the direction orthogonal to the tool virtual plane VS3. The cutting insert 30 has an angle θ1 formed by the insert width axis C2 and the rotation axis WO. It is set within the range of 90 ° ≦ θ1 ≦ 90.5 ° and is mounted on the insert mounting seat 4. In the present embodiment, the θ1 is set to about 90 °. Thereby, in this top view, the angle formed by the extension line of the front cutting edge 41 of the cutting edge 32A parallel to the insert width axis C2 and the rotation axis WO is also θ1 (= 90 °). In FIG. 8, the angle θ4 formed by the insert longitudinal axis C1 and the rotation axis WO is set within a range of 0 ° <θ4 <1 °. In the present embodiment, this θ4 is set to about 0.2 °. Specifically, the relationship between θ4 and θ1 is set to 1 °> θ4> θ1−90 °.

  As shown in FIGS. 8 and 9, when viewed from the direction orthogonal to the tool virtual plane VS3 and facing the rake face 33, the cutting insert 30 is connected to the other width direction C2A of the other cutting edge 32B. The corner portion 43C located on the opposite side is disposed on the other width direction C2A side of the corner portion 43A located on the opposite side of the one cutting edge 32A. That is, the corner portion 43A located on the one side surface 3C side (right side in FIG. 8) of the tool body 1 in one cutting edge 32A is one side surface than the corner portion 43C located on the one side surface 3C side in the other cutting edge 32B. It is arranged on the 3C side. In the present embodiment, the corner portion 43C located on the inner peripheral surface S side in the cutting edge 32B is separated from the inner peripheral surface S with respect to the corner portion 43A located on the inner peripheral surface S side in the cutting edge 32A. .

  Further, by adjusting the above-described θ1 to θ4, as shown in FIGS. 8 and 11, the pair of corner portions 43A and 43B in one of the cutting edges 32A is made to be a work material virtual plane VS4 perpendicular to the rotation axis WO. Can be placed on top. In the present embodiment, the angles θ2 and θ3 are adjusted to be set to an angle θ1 = 90 °, whereby the pair of corner portions 43A and 43B are arranged on the work material virtual plane VS4. Specifically, in the cutting edge 32A, the virtual circle VC1 obtained by rotating the corner portion 43A around the rotation axis WO and the virtual circle VC2 obtained by rotating the corner portion 43B around the rotation axis WO are both cut. It is included in the material virtual plane VS4. The outer circumference (trajectory) of the virtual circle VC1 coincides with the outer peripheral edge portion of the groove bottom D of the groove formed in the work material W, and the outer periphery of the virtual circle VC2 coincides with the inner peripheral edge portion of the groove bottom D. . Further, the front cutting edge 41 of the cutting edge 32A is arranged on the work material virtual plane VS4 in any part located between the corner part 43A and the corner part 43B.

  In the present embodiment, the cutting insert 30 of the tool body 1 having the above-described configuration is arranged in a close proximity so that the corner portion 43A of one of the cutting edges 32A is in contact with the inner peripheral surface S of the work material W. The cutting edge 32A moves in the grooving direction XA toward the rotation axis WO direction of the work material W along the inner peripheral surface S, and grooving is performed with respect to the inner surface B facing the proximal end side of the tool body 1 Process.

  As described above, according to the cutting edge replaceable grooving tool 10 and the end surface grooving method using the same according to the present embodiment, the tip 3 of the tool body 1 is directed toward the inner surface B of the work material W. The front cutting edge 41 of one cutting edge 32A of the cutting insert 30 protruding in parallel is made parallel to the insert width axis C2, and the rotation of the workpiece W gradually rotates toward the other width direction C2A. Since the tool body 1 is inclined toward the rear side in the direction WT, the cutting resistance when the tool body 1 is laterally fed substantially perpendicularly to the central axis TO along the Y direction is reduced.

  That is, in the case of the inner diameter side end face grooving as in the present embodiment, generally, when the tool body 1 is laterally fed, the tool body 1 is moved from the inner peripheral surface S of the work material W to the rotation axis WO side. Move towards. At this time, the other corner portion 43B and the side surface cutting edge 42 located on the moving direction side of the one cutting edge 32A of the cutting insert 30 cut sharply with respect to the work material W, so that the cutting resistance is reduced. The In the inner diameter side end face grooving process of the present embodiment, the component force F2 of the cutting resistance generated during grooving is the central axis TO of the tool body 1 from the side surface 3C side where the cutting insert 30 is disposed in the tool body 1. Since it acts toward the side, the cutting process is stable and the machining accuracy is ensured.

  Further, the insert longitudinal axis C1 of the cutting insert 30 is inclined so as to gradually approach the tool virtual plane VS3 toward the one extending direction C1A, and extends toward the upper surface side of the insert body 31. That is, since the other cutting edge 32B is separated toward the lower surface side of the insert body 31 with respect to the tool virtual plane VS3, the one cutting edge 32A cuts sharply with respect to the inner surface B of the work material W. As a result, the sharpness can be sufficiently enhanced.

  In addition, one corner portion 43C located on the opposite side to the other width direction C2A in the other cutting edge 32B is compared with one corner portion 43A located on the opposite side in the one cutting edge 32A. It arrange | positions at the other width direction C2A side. Accordingly, as in the present embodiment, the inner surface S of the cylindrical hole H formed around the rotation axis WO of the workpiece W is grooved into the inner surface B of the processed hole H. When processing (inner diameter side end face grooving), the following effects are exhibited.

  That is, one corner portion 43 </ b> A of one cutting edge 32 </ b> A of the cutting insert 30 is disposed close to the inner peripheral surface S of the work material W, and the cutting insert 30 is arranged along the inner peripheral surface S. When grooving by moving in the grooving direction XA, one corner portion 43C of the other cutting edge 32B is separated from the inner peripheral surface S, and the corner portion 43C comes into contact with the inner peripheral surface S. It is surely prevented from being damaged. Further, the contact prevents the other unused cutting edge 32B from being damaged.

  Further, regardless of the depth d1 of the back surface B of the work material W shown in FIG. 3, the one corner portion 43C of the other cutting edge 32B is separated from the inner peripheral surface S of the work material W, and this corner portion. It is reliably prevented that 43C contacts and damages the inner peripheral surface S.

  Further, when attention is paid to the groove bottom D of the work material W to be cut by one of the cutting edges 32A, the rotation direction in which the work material W is gradually rotated as the insert width axis C2 of the cutting insert 30 moves toward the other width direction C2A. Inclining toward the rear side of WT, inclining toward the upper surface side of the insert body 31 so that the insert longitudinal axis C1 approaches the virtual tool plane VS3 toward the one extending direction C1A, and One groove portion 43C of the other cutting edge 32B is disposed on the other width direction C2A side of the other cutting edge 32A than the one corner portion 43A of the other cutting edge 32A. It is formed with an inclination close to perpendicular to the rotation axis WO. That is, the angle α of the groove bottom D in FIG. 28 is formed to be relatively small, and the machining accuracy of the groove cut into the work material W is increased.

  Further, the pair of side surface cutting edges 42, 42 provided in each of the cutting edges 32A, 32B are formed to be inclined so as to gradually narrow each other as they go from the outside in the extending direction of the insert body 31 toward the center side. Therefore, the processing accuracy of the groove wall in the processed groove is ensured. That is, even if the mounting posture of the cutting insert 30 with respect to the tool body 1 is set as described above, the one cutting edge 32A is opposite to the inner circumferential surface S side of the workpiece W (that is, the other width direction C2A). The side cutting edge 42 arranged on the side) does not come into contact with the opening edge of the groove wall on the opposite side of the groove formed in the work material W.

  In addition, when the cutting insert 30 is viewed from the direction orthogonal to the tool virtual plane VS3, an angle θ1 formed by the insert width axis C2 along the width direction of the insert body 31 and the rotation axis WO of the workpiece W is 90 ° ≦ θ1. ≦ 90.5 ° is set. Accordingly, in FIG. 8, the angle θ4 at which the insert longitudinal axis C1 along the extending direction of the insert body 31 is inclined with respect to the rotation axis WO of the work material W is a value obtained by subtracting 90 ° from the angle θ1 ( That is, it is set to a value slightly larger than (θ1-90 °) while being approximated to (θ1-90 °). In the present embodiment, the inner peripheral surface S of the work material W is formed in parallel with the rotation axis WO, and the cutting insert 30 has a slightly longer insert longitudinal axis C1 than the inner peripheral surface S of the work material W. While being inclined, the tool body 1 is mounted so as to be substantially parallel. Accordingly, as described above, one corner portion 43C of the other cutting edge 32B is reliably separated from the inner peripheral surface S to ensure the processing accuracy of the inner peripheral surface S, and the inner surface B of the work material W is secured. It is possible to ensure the processing accuracy of the groove bottom D in the groove to be formed. Specifically, by setting the angle θ1 within the above-described range, the groove bottom D of the grooved work material W is formed substantially perpendicular to the rotation axis WO. Has been increased.

  Further, as in the present embodiment, when the pair of corner portions 43A, 43B in the one cutting edge 32A is disposed on the work material virtual plane VS4 perpendicular to the rotation axis WO of the work material W, The groove bottom D of the work material W to be cut with one of the cutting edges 32A can be reliably formed perpendicular to the rotation axis WO. Therefore, the finishing accuracy of the groove of the work material W is sufficiently ensured.

  Thus, in the inner diameter side end face grooving process using the above-described blade edge exchange type grooving tool 10, adjacent to the inner surface B of the processing hole H formed in the work material W to form a cylindrical hole shape, Even when the inner peripheral surface S parallel to the rotation axis WO is formed, the inner diameter side end face grooving can be performed with high accuracy regardless of the position of the inner surface B to be grooved.

(Second Embodiment)
Next, the blade edge replacement type grooving tool 20 according to the second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same member as above-mentioned embodiment, and the description is abbreviate | omitted.

  The cutting edge exchange-type grooving tool 20 of this embodiment performs an outer diameter side end surface grooving process on a substantially cylindrical work material W. Specifically, the work material W has a multistage cylindrical shape, and has a stepped portion U between the large diameter portion and the small diameter portion. The stepped portion U of the work material W is formed with an end surface E that is formed of an annular surface that is adjacent to the outer peripheral surface R of the small-diameter portion and is orthogonal to the rotational axis WO.

  The cutting edge-replaceable grooving tool 20 is formed in an axial shape and has a tool body 1 having a substantially rectangular cross section, and a tip end surface 1A of the tool body 1 that is detachably attached to the tip portion 3 of the tool body 1. And the above-mentioned cutting insert 30 for projecting the cutting edge 32A in the grooving direction XA on the front end side. The cutting edge-replaceable grooving tool 20 rotates about the rotation axis WO in a state where the extending direction (X direction shown in the figure) of the tool body 1 is arranged substantially parallel to the rotation axis WO of the work material W. The tip 3 of the tool body 1 is directed to the stepped portion U of the work material W rotating in the direction WT, the cutting edge 32A is moved along the outer peripheral surface R of the small diameter portion of the stepped portion U, and the end surface E is moved. To cut.

  As with the blade-exchangeable grooving tool 10, the blade-tip-exchangeable grooving tool 20 extends so that the insert longitudinal axis C <b> 1 of the cutting insert 30 is along the extending direction of the tool body 1. On the other hand, as shown in FIG. 13, in the blade replacement type grooving tool 20, one side surface 3 </ b> C (2 </ b> C) and the other side surface 3 </ b> D (2 </ b> D) of both side surfaces facing the side (Y direction) of the tool body 1. ) Is different from the above-described cutting edge exchange grooving tool 10.

  The tool main body 1 of the blade-tip-exchange-type grooving tool 20 has a central portion and a base end portion other than the distal end portion 3 forming a substantially rectangular parallelepiped shape as a shank portion 2. One side surface 2C and the other side surface 2D of the shank portion 2 are each formed in a rectangular planar shape. The cutting edge replacement type grooving tool 20 is fixedly supported on the machine tool M indicated by a two-dot chain line in FIG. 15 by being held in a state where the shank portion 2 is prevented from rotating. Specifically, the blade-exchangeable grooving tool 20 is supported by the machine tool M in a state where at least the lower surface 2B and the other side surface 2D of the shank portion 2 of the tool body 1 are in contact with the mounting recess m of the machine tool M. Yes.

  Further, as shown in FIG. 15, the portion corresponding to the upper jaw portion 6 on one side surface 3C of the tip portion 3 is gradually curved in a cross-sectional concave shape so as to gradually go to the other side surface 3D side from the upper surface 3A toward the lower surface 3B. Is formed. Further, the side surface facing the other side surface 3D side in the upper jaw portion 6 is formed to be curved in a convex curve shape so as to gradually go to the other side surface 3D side from the upper surface 3A toward the lower surface 3B. In addition, a portion corresponding to the lower jaw portion 7 on one side surface 3C of the tip portion 3 is formed to be curved in a cross-sectional concave curve so as to gradually move toward the one side surface 3C side from the upper surface 3A toward the lower surface 3B. Further, the side surface facing the other side surface 3D side of the lower jaw 7 is formed to be curved in a convex curve shape so as to gradually move toward the one side surface 3C side from the upper surface 3A toward the lower surface 3B. In the front view of FIG. 15, the upper jaw part 6 and the lower jaw part 7 are formed in a substantially arcuate shape as a whole.

  And the cutting insert 30 is arrange | positioned along the said one side 3C in the front-end | tip part 3 of the tool main body 1. FIG. As shown in FIGS. 13, 16, and 18, one corner portion 43 </ b> A (43 </ b> C) of the cutting insert 30 is located on one side 2 </ b> C, 3 </ b> C side of the tool body 1 and the small diameter of the work material W is set. It arrange | positions so that the outer peripheral surface R of a part may be opposed. In this cutting edge replaceable grooving tool 20, the other width direction C2A from one corner portion 43A (43C) to the other corner portion 43B (43D) is opposite to that of the above described cutting edge replaceable grooving tool 10. It is set to face.

  Further, in the front view of FIG. 19, the front cutting edge 41 of one cutting edge 32A is gradually inclined toward the rear side in the rotation direction WT of the workpiece W as it goes to the other width direction C2A. In addition, by this, in one cutting edge 32A, the corner portion 43B located on the other width direction C2A side of the pair of corner portions 43A and 43B has a rotational direction WT of the work material W with respect to the corner portion 43A. It is arranged on the rear side.

  In the present embodiment, the front cutting edge 41 of the cutting edge 32A gradually moves toward the rear side in the rotation direction WT of the work material W as it is separated from the outer peripheral surface R of the small diameter portion toward the side opposite to the rotation axis WO. Is inclined. The tool virtual plane VS3 is formed including the corner portion 43A of the cutting edge 32A and the rotation axis WO. 15 and 19, the angle θ2 formed by the front cutting edge 41 of the cutting edge 32A and the tool virtual plane VS3 is set within a range of 0 ° <θ2 ≦ 7 °. In the present embodiment, θ2 is set to about 3.4 °, for example. Further, since the insert width axis C2 is parallel to the front cutting edge 41, it can be said that the angle θ2 is an angle formed by the insert width axis C2 and the tool virtual plane VS3.

  Further, as shown in FIG. 14, when viewed from the side surface 3C side of the tool body 1, the insert longitudinal axis C1 of the cutting insert 30 gradually approaches the virtual tool plane VS3 as it goes in the one extending direction C1A. It is inclined to.

  Specifically, the insert longitudinal axis C1 gradually increases from the lower surface side (left side in the left-right direction (Z direction) in FIG. 14) to the upper surface side (right side in the Z direction in FIG. 14) as it goes in the one extending direction C1A. ) Toward the tool virtual plane VS3. Thereby, the front cutting edge 41 of the cutting edge 32B is separated toward the lower surface side of the insert main body 31 with respect to the tool virtual plane VS3. The angle θ3 formed by the insert longitudinal axis C1 and the tool virtual plane VS3 is set within a range of 0 ° <θ3 ≦ 10 °. In the present embodiment, this θ3 is set to about 3 °, for example.

  FIG. 13 is a top view of the cutting insert 30 as viewed from the direction orthogonal to the tool virtual plane VS3. The cutting insert 30 has an angle θ1 between the insert width axis C2 and the rotation axis WO of 90 ° ≦ It is set within the range of θ1 ≦ 90.5 ° and is mounted on the insert mounting seat 4. In the present embodiment, the θ1 is set to about 90 °. Thereby, in this top view, the angle formed by the extension line of the front cutting edge 41 of the cutting edge 32A parallel to the insert width axis C2 and the rotation axis WO is also θ1 (= 90 °). In FIG. 13, the angle θ4 formed by the insert longitudinal axis C1 and the rotation axis WO is set in the range of 0 ° <θ4 <1 °. In the present embodiment, this θ4 is set to about 0.2 °. Specifically, the relationship between θ4 and θ1 is set to 1 °> θ4> θ1−90 °.

  Then, as shown in FIG. 18, when viewed from the direction orthogonal to the tool virtual plane VS3 and facing the rake face 33, the cutting insert 30 is opposite to the other width direction C2A of the other cutting edge 32B. The corner portion 43C located at the side of the other cutting edge 32A is disposed closer to the other width direction C2A than the corner portion 43A located on the opposite side of the one cutting edge 32A. That is, the corner portion 43A located on the one side surface 3C side (left side in FIG. 18) of the tool body 1 in one cutting edge 32A is one side surface than the corner portion 43C located on the one side surface 3C side in the other cutting edge 32B. It is arranged on the 3C side. In the present embodiment, the corner portion 43C located on the outer peripheral surface R side in the cutting edge 32B is separated from the outer peripheral surface R with respect to the corner portion 43A located on the outer peripheral surface R side in the cutting edge 32A.

  Further, by adjusting the above-described θ1 to θ4, as shown in FIGS. 18 and 20, the pair of corner portions 43A and 43B in one of the cutting edges 32A is made to be a work material virtual plane VS4 perpendicular to the rotation axis WO. Can be placed on top. In the present embodiment, the angles θ2 and θ3 are adjusted to be set to an angle θ1 = 90 °, whereby the pair of corner portions 43A and 43B are arranged on the work material virtual plane VS4. Specifically, in the cutting edge 32A, the virtual circle VC1 obtained by rotating the corner portion 43A around the rotation axis WO and the virtual circle VC2 obtained by rotating the corner portion 43B around the rotation axis WO are both cut. It is included in the material virtual plane VS4. The outer circumference of the virtual circle VC1 coincides with the inner peripheral edge portion of the groove bottom D of the groove formed in the workpiece W, and the outer periphery of the virtual circle VC2 coincides with the outer peripheral edge portion of the groove bottom D.

  In the present embodiment, the cutting insert 30 of the tool body 1 having the above-described configuration is disposed close to each other so that the corner portion 43A of one cutting edge 32A abuts the outer peripheral surface R of the small diameter portion of the work material W. In this state, the cutting edge 32A moves along the outer peripheral surface R in the grooving direction XA toward the rotation axis WO of the work material W, and the cutting edge 32A is a groove with respect to the end surface E facing the base end side of the tool body 1. Put and process.

  According to the cutting edge replacement type grooving tool 20 according to the present embodiment, in the stepped portion U of the workpiece W having a multistage cylindrical shape, the workpiece is cut along the small diameter portion having the outer peripheral surface R parallel to the rotation axis WO. When the end surface E of the material W is grooved (outer diameter side end surface grooving), the same effects as those of the above-described embodiment are exhibited. That is, regardless of the position of the end surface E of the work material W into which the cutting edge 32A of the cutting insert 30 is grooved, the corner portion 43C of the cutting edge 32B is separated from the outer peripheral surface R, and this corner portion 43C is the outer peripheral surface. It is possible to surely prevent damage from contact with R, and to perform grooving of the outer diameter side end face with high accuracy.

  Further, the front cutting edge 41 of one cutting edge 32A of the cutting insert 30 protruding from the tip 3 of the tool body 1 toward the end surface E of the workpiece W is parallel to the insert width axis C2. Since it is inclined toward the rear side in the rotational direction in which the work material rotates gradually toward the other width direction C2A, the cutting resistance when the tool body 1 is laterally fed along the Y direction is To reduce.

  That is, in the case of outer diameter side end face grooving as in the present embodiment, generally, when the tool body 1 is laterally fed, the tool body 1 is referred to as the rotation axis WO from the outer peripheral surface R of the work material W. Move to the other side. At this time, the other corner portion 43B and the side surface cutting edge 42 located on the moving direction side of the one cutting edge 32A of the cutting insert 30 cut sharply with respect to the work material W, so that the cutting resistance is reduced. The

  Further, the blade edge exchange type grooving tool 20 is supported in a state in which the lower surface 2B and the other side surface 2D of the shank portion 2 of the tool body 1 are in contact with the mounting recess m of the machine tool M. By setting the front cutting edge 41 in the cutting edge 32A of the cutting insert 30 as described above, an external force (cutting resistance) received by the one cutting edge 32A from the work material W during grooving as shown in FIG. ) The FT is generated from the top to the bottom along the insert height axis C3 perpendicular to the front cutting edge 41 of the cutting edge 32A. This cutting resistance FT includes a component force F1 in the Z direction and a component force F2 in the Y direction. The component force F1 acts to press the lower surface 2B of the tool body 1 against the machine tool M, and the component force F2 acts to press the other side 2D of the tool body 1 against the machine tool M. As a result, the position of the cutting edge exchange-type grooving tool 20 with respect to the machine tool M at the time of cutting is stabilized, and highly accurate cutting can be performed stably.

In addition, this invention is not limited to the above-mentioned embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the insert mounting seat 4 is formed at the tip 3 of the tool body 1. However, the present invention is not limited to this, and a detachable head is attached to the tip 3. In addition, the insert mounting seat 4 may be formed on the head portion. In this case, the insert mounting seat 4 is formed to open on one side surface of the head portion, and the cutting insert 30 is disposed along the one side surface. Moreover, the shape of the tool main body 1 described above is not limited to that described in the above embodiment.

  Further, the pair of corner portions 43 of the cutting edge 32 is not limited to the shape described in the above embodiment. 21 and 22 show a modified example of the corner portion 43. In FIG. 21, the corner portion 43 has a convex curve shape and includes a first corner blade 44 that smoothly connects the front cutting edge 41 and the side cutting edge 42. The corner portion 43A of the one cutting edge 32A is directed from the extension line VL1 of the front cutting edge 41 adjacent to the corner portion 43A to the extension line VL1 from the outer edge portion of the insert body 31 in the first corner blade 44 in the width direction. An intersection point P with the extended vertical line VL2 is arranged on the tool virtual plane VS3. In this case, chipping of the edge of each corner portion 43 is prevented.

  In FIG. 22, the corner portion 43 includes a first corner blade 44, an end portion on the center side (upper side in FIG. 22) along the extending direction of the insert body 31 in the first corner blade 44, and a side cutting blade. And a second corner blade 45 having a linear shape that connects the first and second corner blades 42 to each other. When the cutting insert 30 is viewed from the direction orthogonal to the tool virtual plane VS3, the second corner blade 45 extends so as to be parallel to the rotation axis WO of the workpiece W, and the inner peripheral surface S (outer periphery). It is formed to extend parallel to the surface R). In this case, the second corner blade 45 exposes the groove wall of the work material W cut by the front cutting edge 41 and the first corner blade 44 of the one cutting edge 32A, and the finishing accuracy of the groove wall is increased. It is done.

  In the above-described embodiment, the cutting edge 32A of the cutting insert 30 is grooved into the end faces B and E along the peripheral surfaces S and R of the work material W. However, the present invention is not limited to this. is not. For example, the end surfaces B and E separated from the peripheral surfaces S and R of the work material W may be grooved. According to the embodiment of the present invention, even when any of the end faces B and E adjacent to the peripheral surfaces S and R of the work material W or the separated end faces B and E is grooved, high accuracy is achieved. Cutting can be performed.

DESCRIPTION OF SYMBOLS 1 Tool body 1A Tip surface 2C, 3C One side surface 3 Tip part 10, 20 Cutting edge exchange-type grooving tool 30 Cutting insert 31 Insert body 32 Cutting edge 32A One cutting edge 32B The other cutting edge 41 Front cutting edge 42 Side cutting edge 43 Corner part 43A One corner part located on the opposite side to the other width direction C2A in one cutting edge 43B The other corner part 43C located on the other width direction C2A side in one cutting edge In the other cutting edge One corner portion 43D located on the opposite side to the other width direction C2A 43D The other corner portion located on the other width direction C2A side in the other cutting edge 44 First corner blade 45 Second corner blade B Back face (end face) )
C1 insert longitudinal axis (extending direction of the insert body)
C1A One extending direction, which is a direction from the other cutting edge toward one cutting edge in the extending direction of the insert main body C2 Insert width axis (width direction of the insert main body)
C2A Of the width direction of the insert body, the other width direction is the direction from one corner portion toward the other corner portion. C3 Insert height axis (height direction of the insert body)
E End face H Machining hole P Intersection of extension line VL1 and perpendicular line VL2 R Outer peripheral surface (peripheral surface) of work material
S Inner peripheral surface (peripheral surface)
U Stepped portion VL1 Front cutting edge extension line VL2 Perpendicular line extending from the outer edge of the first corner blade toward the extension line VL1 VS1 Insert virtual plane VS3 Tool virtual plane VS4 Workpiece virtual plane W Workpiece WO Workpiece Rotation axis of WT Rotation direction of workpiece XA Groove direction θ1 Angle between insert width axis and rotation axis of workpiece

Claims (8)

A cutting insert having a cutting edge projecting toward an end surface of a work material that rotates about a rotation axis, and a tool body that has a shaft shape, and the cutting insert is detachably attached to a tip portion. , A cutting edge replaceable grooving tool for grooving the end face with the cutting edge,
The cutting insert includes a pair of cutting edges on the upper surface of the insert body at both ends in the extending direction of the rod-shaped insert body, and the width direction perpendicular to the center of the insert body and the extending direction Are formed rotationally symmetric with respect to the insert height axis perpendicular to the extending direction and the width direction through the center of the insert, and plane symmetric with respect to the insert virtual plane that includes the insert height axis and is perpendicular to the extending direction.
The cutting edge is formed at an edge of the insert body in the extending direction and extends along the width direction, and a pair of cutting edges disposed at both ends of the front cutting edge and projecting in the width direction. A corner portion, and a pair of side cutting edges each extending so as to gradually narrow the distance from each other toward the center side of the insert body along the extending direction from the corner portion,
The tool body has the cutting insert arranged along one side surface facing the side of the tool body, and one cutting edge of the pair of cutting edges is disposed on the tip side from the tip surface of the tip portion. Protruding in the grooving direction toward
The cutting insert is
The insert width axis along the width direction passing through the center in the extending direction of the insert main body is from one corner portion located on one side of the tool main body in the pair of corner portions to the other. Inclined toward the rear side of the rotational direction of rotation of the work material gradually toward the other width direction, which is the direction toward the corner,
The insert longitudinal axis passing through the center in the width direction of the insert body and extending along the extending direction is inclined with respect to the virtual tool plane including the one corner portion and the rotation axis in the one cutting edge, and Of the extending direction, the upper surface of the insert body gradually approaches the tool imaginary plane as it goes in one extending direction, which is a direction from the other cutting edge of the pair of cutting edges to the one cutting edge. Extending to the side,
One corner portion located on the side opposite to the other width direction in the other cutting edge is disposed on the other width direction side than the one corner portion in the one cutting edge. A cutting edge exchangeable grooving tool. It is a blade exchange type grooving tool according to claim 1,
An angle θ1 formed by the insert width axis and the rotation axis when the cutting insert is viewed from a direction orthogonal to the tool virtual plane is set to 90 ° ≦ θ1 ≦ 90.5 °. Replaceable grooving tool. It is a blade exchange type grooving tool according to claim 1 or 2,
The end surface is a back surface facing the base end side of the tool body in a processing hole formed in the work material,
The one of the cutting edges is subjected to an inner diameter side end face grooving process with respect to the inner surface. It is a blade exchange type grooving tool according to claim 1 or 2,
The end surface is an end surface facing the base end side of the tool body in a step portion formed on the outer peripheral surface of the work material;
The one of the cutting edges is an edge diameter side end grooving process with respect to the end face. It is a cutting edge exchange-type grooving tool as described in any one of Claims 1-4,
The pair of corner portions of the one cutting edge are arranged on a work material virtual plane perpendicular to the rotation axis, wherein the cutting edge exchange type grooving tool is characterized. It is a blade-tip-exchange-type grooving tool according to any one of claims 1 to 5,
The corner portion has a convex curved first corner blade,
The one corner portion of the one cutting edge includes an extension line of the front cutting edge adjacent to the corner portion and a perpendicular extending from the outer edge portion in the width direction of the first corner blade toward the extension line. The blade tip exchange type grooving tool is characterized in that the intersecting points are arranged on the virtual tool plane. It is a blade exchange type grooving tool according to claim 6,
The corner portion has a linear second corner blade that connects the end portion on the center side in the extending direction of the insert body in the first corner blade and the side surface cutting blade,
When the cutting insert is viewed from a direction orthogonal to the tool virtual plane, the second corner blade extends so as to be parallel to the rotation axis of the work material. Insert tool. A cutting edge having a cutting insert having a cutting edge projecting toward an end face of a work material that rotates about a rotation axis, and a tool body that has an axial shape and the cutting insert is detachably attached to a tip portion Using an exchange-type grooving tool, an end face grooving method for grooving the end face of the work material with the cutting edge,
The cutting insert includes a pair of cutting edges on the upper surface of the insert body at both ends in the extending direction of the rod-shaped insert body, and the width direction perpendicular to the center of the insert body and the extending direction Are formed rotationally symmetric with respect to the insert height axis perpendicular to the extending direction and the width direction through the center of the insert, and plane symmetric with respect to the insert virtual plane that includes the insert height axis and is perpendicular to the extending direction.
The cutting edge is formed at an edge of the insert body in the extending direction and extends along the width direction, and a pair of cutting edges disposed at both ends of the front cutting edge and projecting in the width direction. A corner portion, and a pair of side cutting edges each extending so as to gradually narrow the distance from each other toward the center side of the insert body along the extending direction from the corner portion,
The cutting insert is arranged along one side surface facing the side of the tool body, and one of the pair of cutting blades is grooved from the tip surface of the tip portion toward the tip side. When grooving to the end face by moving the one cutting edge along the grooving direction, and attaching to the tool body,
The insert width axis along the width direction passing through the center in the extending direction of the insert body is changed from one corner portion to the other side of the tool body in the pair of corner portions. Inclining toward the rear side of the rotational direction in which the work material rotates gradually as it goes in the other width direction, which is the direction toward the corner,
The insert longitudinal axis along the extending direction passing through the center in the width direction of the insert main body is inclined with respect to a virtual tool plane including one corner portion of the one cutting edge and the rotation axis, and the extension Of the pair of cutting edges toward the upper surface side of the insert body so as to gradually approach the tool imaginary plane as it extends in the one extending direction from the other cutting edge toward the one cutting edge. Extend towards
One corner portion located on the opposite side to the other width direction in the other cutting edge is arranged on the other width direction side with respect to the one corner portion in the one cutting edge. End face grooving method.

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