JP5560748B2 - Exchangeable grooving tool and peripheral grooving method - Google Patents

Description

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

  Conventionally, a work piece made of a metal material or the like is rotated around a rotation axis, and a groove is formed by a cutting insert cutting edge on the outer peripheral surface of the work material or an inner peripheral surface of a machining hole formed around the rotation axis. 2. Description of the Related Art There is known a blade edge exchange type grooving tool for performing a machining process. 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 (vertical direction (Y direction in FIG. 23)) of the rod-shaped insert main body 31. Of these cutting edges 32, one cutting edge 32 </ b> A protruding from the outer peripheral surface of the tool body 1 performs grooving processing (inner diameter grooving) on the inner peripheral surface S of the processing hole H of the work material W. In the example of FIG. 23, the work material W is formed with a back surface (end surface) B that is adjacent to the inner peripheral surface S and orthogonal to the rotation axis WO, and one of the cutting edges 32A is formed on the end surface B. The inner circumferential surface S is grooved by moving in the Y direction perpendicular to the rotation axis WO so as to follow. 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 outer peripheral surface of the tool body 1 and is used for grooving.

  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 moves in the Y direction perpendicular to the rotation axis WO along the stepped portion U of the work material W formed in a multistage cylindrical shape. Thus, grooving (outer diameter grooving) is performed on the outer peripheral surface of the work material W. In this example, the stepped portion U of the work material W is formed with an end surface E adjacent to the small diameter portion of the outer peripheral surface and orthogonal to the rotation axis WO, and one of the cutting edges 32A is along the end surface E. Thus, the grooving process is performed on the small-diameter portion.

In this way, peripheral surface grooving such as inner diameter grooving and outer diameter grooving using the blade exchange type grooving tools 100 and 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.
The cutting insert 30 is arranged such that the extending direction of the insert main body 31 (insert longitudinal axis C1 shown in FIGS. 23 and 24) extends in parallel to the end surfaces B and E of the work material W, and The cutting edges 32 have the same distance from the end faces B and E. In such an arrangement state of the cutting insert 30, there is no particular problem when one of the cutting edges 32A is spaced from the end faces B and E of the work material W and grooving the peripheral surface. When grooving the peripheral surface while moving along the end surfaces B and E of the work material W, the other cutting edge 32B contacts the end surfaces B and E and is damaged. 24, the relationship between the diameter φd1 of the large diameter portion where the end face E is formed in the work material W and the distance L3 from the other cutting edge 32B to the rotation axis WO is d1 / 2. <L3, there is no contact, but since contact is made when d1 / 2 ≧ L3, the shape of the work material W is limited, and the distance L3 is reduced during processing, and the contact described above. May occur. 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 FIG. 25, the corner portion 43 </ b> C located on the end surface B, E side of the work material W contacts the end surfaces B, E at the other cutting edge 32 </ b> B. For this reason, the peripheral surface grooving along the end surfaces B and E of the work material W as shown in FIGS. 23 and 24 could not be performed.

  In order to prevent such contact with the end faces B and E of the cutting edge 32B, 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. 26 and 27, 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 while being inclined with respect to the Y direction so as to gradually move away from the end surface B (E) of the work material W as it goes toward the cutting edge 32B. Thereby, since the corner part 43C arrange | positioned at the end surface B (E) side of the other cutting edge 32B in the cutting insert 30 is arrange | positioned spaced apart from this end surface B (E), the above-mentioned contact is prevented. The

  However, in this case, if attention is paid to one of the cutting edges 32A, as shown in FIG. 27, the front cutting edge 41 of the cutting edge 32A has an angle α in the drawing with respect to a virtual line WO1 parallel to the rotation axis WO. Will be inclined. Originally, the groove bottom D of the groove formed by grooving is required to be parallel to the rotation axis WO. However, as described above, the front cutting edge 41 is inclined, so that the cut groove The groove bottom D is also inclined by the angle α with respect to the rotation axis WO, and sufficient processing 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. When the cutting insert is attached to the tool body, the corner portion on the end surface B (E) side of the other cutting edge is more the end surface B (E) than the corner portion on the end surface B (E) side of the one cutting blade. ). 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 the peripheral surface grooving is performed along the end surface of the work material without increasing the number of parts of the cutting insert, the processing accuracy is increased. It is an object of the present invention to provide a blade replacement type grooving tool and a peripheral surface 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 in which a cutting edge protrudes toward the peripheral surface of a work material that rotates about a rotation axis, and a tool that has an axial shape and is detachably attached to a tip portion. A cutting edge replacement type grooving tool that grooving the peripheral surface with the cutting blade, wherein the cutting insert is at both ends in the extending direction of the rod-shaped insert body. A pair of cutting edges on the upper surface of the insert body, and a rotational symmetry 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 an insert imaginary plane that is perpendicular to the extending direction and includes the insert height axis, and the cutting edge is formed at the 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 as it goes to the side, and the tool body projects one of the pair of cutting edges in the grooving direction. The cutting insert is mounted, and the cutting insert is disposed on the tool body so as to be along a tip surface facing the tip side of the tool body, and the grooving direction is the center of the tool body. a direction away from the axis, the cutting insert, the insert width axis along the extending direction of the center of the insert body as the width direction, of the width direction, the pair of code Is inclined gradually toward the lower side of the tool body in accordance with the direction from one of the corner portions located on the distal end side of the tool body to the other in the width direction is a direction toward the other corner portion in over portion, said insert An insert longitudinal axis passing through the center in the width direction of the main body and extending along the extending direction is inclined with respect to a virtual tool plane including the other corner portion of the one cutting edge and perpendicular to the vertical direction of the tool main body . together with the one in the extending direction, the tool gradually so as to approach to the tool virtual plane as it goes from the other of the cutting edge in the pair of cutting edges said to one of the one extending direction is a direction toward the cutting edge One corner portion that extends toward the lower side of the main body and is located on the opposite side to the other width direction of the other cutting edge is the first cutting edge. The one corner portion that is disposed on the other width direction side relative to the one corner portion and that is positioned closer to the tip side of the tool body than the other corner portion of the other cutting edge is the one side It is characterized by being arranged on the base end side of the tool main body with respect to the one corner portion located on the tip side of the tool main body with respect to the other corner portion of the cutting edge .
The present invention also provides a cutting insert having a cutting edge projecting toward the peripheral surface of a work material that rotates about a rotation axis, and a tool that has a shaft shape and is detachably attached to the tip portion. A cutting edge replacement type grooving tool that grooving the peripheral surface with the cutting blade, wherein the cutting insert is at both ends in the extending direction of the rod-shaped insert body. A pair of cutting edges on the upper surface of the insert body, and a rotational symmetry 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 an insert imaginary plane that includes the insert height axis and is perpendicular to the extending direction, and the cutting edge is formed at the edge of the insert body in the extending direction and has the width. A front cutting edge extending along the direction, a pair of corner portions disposed at both ends of the front cutting edge and projecting in the width direction, and a center side of the insert body along the extending direction from the corner portion A pair of side surface cutting edges each extending so as to gradually narrow each other as it goes to the tool body, and the tool body projects one of the pair of cutting edges in the grooving direction, The cutting insert is mounted, and the cutting insert is arranged on the tool body so as to be along a side surface facing the side of the tool body, and the grooving direction is the tip side of the tool body. The cutting insert has an insert width axis along the width direction passing through the center of the extending direction of the insert main body at the pair of corner portions in the width direction. Inclining gradually toward the lower side of the tool body gradually toward the other width direction, which is a direction from one corner portion located in a direction away from the central axis of the tool body to the other corner portion, An insert longitudinal axis along the extending direction passing through the center of the insert body in the width direction is inclined with respect to a virtual tool plane including the other corner portion of the one cutting edge and perpendicular to the vertical direction of the tool body. And, in the extending direction, the tool gradually approaches the imaginary plane as it goes from the other cutting edge of the pair of cutting edges toward the one cutting edge. One corner portion that extends toward the lower side of the tool body and is located on the side opposite to the other width direction of the other cutting edge is located in the one cutting edge. The one of the first and second corners is disposed on the other width direction side, and the one of the other cutting edges is located in a direction away from the central axis of the tool body than the other corner portion. A corner portion is arranged in a direction approaching the central axis with respect to the one corner portion positioned in a direction away from the central axis than the other corner of the one cutting edge. And
The present invention also provides a cutting insert having a cutting edge projecting toward the peripheral surface of a work material that rotates about a rotation axis, and a tool that has a shaft shape and is detachably attached to the tip portion. A peripheral grooving method for grooving the peripheral surface of the work material with the cutting edge using a blade-exchangeable grooving tool having a main body, wherein the cutting insert is a rod-shaped insert A pair of cutting edges are provided on the upper surface of the insert main body at both ends in the extending direction of the main body, 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, and It is formed rotationally symmetric with respect to the insert height axis perpendicular to the width direction and symmetric with respect to the 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 extending so as to gradually narrow each other as it goes toward the center side of the insert body along the extending direction, and the cutting insert is one of the pair of cutting edges. When projecting the cutting edge in the grooving direction and mounting it on the tool body, and grooving the peripheral surface by moving the one 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 is changed from one corner portion to the other corner portion in the pair of corner portions in the width direction. Increasing the longitudinal direction of the insert body along the extending direction through the center in the width direction of the insert body by inclining toward the front side of the rotational direction in which the work material rotates gradually toward the other width direction, which is the direction of cutting. Inclining with respect to the tool virtual plane including the other corner portion and the rotation axis in the one cutting edge, and from the other cutting edge in the pair of cutting edges to the one cutting edge in the extending direction. As it goes to one extending direction that is the direction to which it goes, it gradually extends toward the front side in the rotational direction so as to approach the tool virtual plane, and the peripheral surface of the work material is orthogonal to the rotational axis It is an inner peripheral surface facing the inner side in the radial direction, of this work material, rising toward the inner side in the radial direction adjacent to the inner peripheral surface and with respect to the end surface formed perpendicular to the rotation axis The one corner portion of the other cutting edge is arranged away from the one corner portion cut into the inner peripheral surface along the end face of the one cutting edge .
The present invention also provides a cutting insert having a cutting edge projecting toward the peripheral surface of a work material that rotates about a rotation axis, and a tool that has a shaft shape and is detachably attached to the tip portion. A peripheral grooving method for grooving the peripheral surface of the work material with the cutting edge using a blade-exchangeable grooving tool having a main body, wherein the cutting insert is a rod-shaped insert A pair of cutting edges are provided on the upper surface of the insert main body at both ends in the extending direction of the main body, 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, and It is formed rotationally symmetric with respect to the insert height axis perpendicular to the width direction and symmetric with respect to the 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 extending so as to gradually narrow each other as it goes toward the center side of the insert body along the extending direction, and the cutting insert is one of the pair of cutting edges. When projecting the cutting edge in the grooving direction and mounting it on the tool body, and grooving the peripheral surface by moving the one 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 is changed from one corner portion to the other corner portion in the pair of corner portions in the width direction. Inclined toward the front side of the rotational direction of rotation of the work material gradually toward the other width direction which is the direction of the cutting, and the insert longitudinal axis along the extending direction through the center in the width direction of the insert body, Inclining with respect to the tool virtual plane including the other corner portion and the rotation axis in the one cutting edge, and from the other cutting edge in the pair of cutting edges to the one cutting edge in the extending direction. As it goes to one extending direction that is the direction to which it goes, it gradually extends toward the front side in the rotational direction so as to approach the tool virtual plane, and the peripheral surface of the work material is orthogonal to the rotational axis It is an outer peripheral surface that faces the outer side in the radial direction, of the work material, with respect to the end surface that rises toward the outer side in the radial direction adjacent to the outer peripheral surface and is perpendicular to the rotation axis The one corner portion of the other cutting edge is arranged away from the one corner portion cut into the outer peripheral surface along the end face of the one cutting edge.

  According to the cutting edge replaceable grooving tool and the peripheral 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 peripheral surface of the work material Is inclined toward the front side in the rotational direction in which the work material rotates gradually as it goes in the other width direction so as to be parallel to the insert width axis. In contrast, a positive angle is set. Therefore, the discharge property of the chips cut by one of the cutting edges is enhanced.

  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 lower surface side of the insert body. That is, since the other cutting edge is separated from the tool virtual plane toward the upper surface side of the insert body, the wedge angle of one cutting edge can be set large. Therefore, the cutting edge strength of one of the cutting edges for grooving the work material is sufficiently ensured.

  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. Thus, for example, when grooving (inner diameter grooving) is performed on the inner peripheral surface of the processing hole along the inner surface (end surface) of the cylindrical hole-shaped processing hole formed around the rotation axis of the work material In addition, the following effects can be obtained. That is, for example, one corner portion of one cutting edge of the cutting insert is disposed close to the end surface of the work material, and this cutting insert is moved along the end surface in the grooving direction to perform grooving. When this is done, it is reliably prevented that one corner portion of the other cutting edge is separated from the end surface and the corner portion contacts the end surface and is damaged. Further, the contact prevents the other unused cutting edge from being damaged. Further, in the step portion of the work material having a multi-stage columnar shape, the case where grooving processing (outer diameter grooving) is performed on the outer peripheral surface of the work material along the end surface orthogonal to the rotation axis has been described with reference to FIG. Regardless of the diameter d1 of the large-diameter portion of the work material W, it is ensured that one corner of the other cutting edge is separated from this end face, and this corner comes into contact with the end face and is damaged. Is prevented.

  Further, when attention is paid to the groove bottom of the work material to be cut by one cutting edge, as described above, the front of the rotation direction in which the work material rotates gradually as the insert width axis of the cutting insert moves toward the other width direction. Inclined toward the side, inclined toward the lower surface side of the insert body so as to approach the tool virtual plane as the longitudinal axis of the insert approaches the one extending direction, and one of the other cutting edges By arranging the corner portion on the other width direction side with respect to the one corner portion of one of the cutting edges, the groove bottom is formed with an inclination nearly parallel to the rotation axis of the work material. Will be. That is, the angle α of the groove bottom D described with reference to FIG. 27 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. In other words, even if the mounting posture of the cutting insert with respect to the tool body is set as described above, the side cut disposed on the side opposite to the end face side of the work material (that is, the other width direction side) on one cutting edge. The blade 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.

Moreover, in the cutting edge exchange-type 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 0 ° ≦ θ1 ≦. It may be set to 0.5 °.
In the circumferential grooving method 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 0 ° ≦ θ1 ≦. It is good also as setting to 0.5 degree.

According to the cutting edge replaceable grooving tool and the peripheral surface grooving method according to the present invention, for example, when the end surface of the work material is formed perpendicular to the rotation axis, the extending direction of the insert body is covered. The angle inclined with respect to the end face of the cutting material is set to a value slightly larger than θ1 while approximating the set value of the angle θ1 formed by the insert width axis and the rotation axis. That is, the orientation of the cutting insert with respect to the tool body is substantially parallel with the extending direction (insert longitudinal axis) of the insert body being substantially inclined with respect to the end surface of the work material, as described above. One corner of the other cutting edge can be reliably separated from the end face. Therefore, the processing accuracy of the groove bottom of the grooved work material is more reliably increased.

  Further, in the edge-changing grooving tool according to the present invention, the peripheral surface is an inner peripheral surface facing the rotation axis side of the work material, and the one cutting edge has an inner diameter with respect to the inner peripheral surface. Grooving may be performed.

  According to the cutting edge replaceable grooving tool according to the present invention, for example, a back surface (end surface) perpendicular to the rotation axis is formed adjacent to the inner peripheral surface of a cylindrical hole-shaped processing hole formed in a work material. Even in the case where the groove is formed, it is possible to perform grooving with high accuracy regardless of the position of the inner peripheral surface to be grooved.

Moreover, in the cutting edge-replaceable grooving tool according to the present invention, the tool body projects the one cutting edge from the outer peripheral surface of the tip end sideward, and the cutting insert is the one of the cutting inserts. The front cutting edge of the cutting edge may be gradually inclined toward the lower side of the tool main body toward the base end side from the distal end side of the tool main body, and may be set to a positive angle.

  According to the cutting edge replaceable grooving tool according to the present invention, for example, a back surface (end surface) perpendicular to the rotation axis is formed adjacent to the inner peripheral surface of a cylindrical hole-shaped processing hole formed in a work material. In such a case, the following effects are obtained. That is, the front cutting edge of one of the cutting edges is set to a positive angle as described above, so that the chip generated by cutting one of the cutting edges is the exit direction of the machining hole on the side opposite to the inner surface. Therefore, chips are prevented from damaging the inner surface, and the discharge performance is improved.

  Further, in the cutting edge-replaceable grooving tool according to the present invention, the peripheral surface is an outer peripheral surface facing away from the rotation axis of the work material, and the one cutting edge is in relation to the outer peripheral surface. It is good also as carrying out an outer diameter grooving process.

  According to the cutting edge exchange type grooving tool according to the present invention, for example, in the step portion of the work material having a multi-stage columnar shape, an end surface that is formed of an annular surface adjacent to the small diameter portion of the outer peripheral surface and orthogonal to the rotation axis is formed. Even if it is the case, it is possible to perform grooving with high accuracy regardless of the position of the outer peripheral surface to be grooved.

Further, in the cutting edge exchange-type grooving tool according to the present invention, the tool body has the cutting insert arranged along one side surface facing the side of the tool body, and the one cutting edge is the The cutting insert projects from the distal end surface toward the distal end side, and the cutting insert has the front cutting edge of the one cutting edge facing the side opposite to the one side surface from the one side surface side. It may be set to a positive angle by gradually inclining toward the lower side of the tool body as it goes to the other side surface.

According to the cutting edge exchange type grooving tool according to the present invention, for example, in the step portion of the work material having a multi-stage columnar shape, an end surface that is formed of an annular surface adjacent to the small diameter portion of the outer peripheral surface and orthogonal to the rotation axis is formed. When it is, the following effects are obtained. That is, since the front cutting edge of one of the cutting edges is set to a positive angle as described above, chips generated by cutting one of the cutting edges are directed toward the small diameter portion on the side opposite to the end face. Therefore, it is possible to prevent chips from damaging the end face and to improve the discharge performance.
Further, in the circumferential grooving method according to the present invention, the front cutting edge of the one cutting edge is gradually inclined toward the front side in the rotational direction as the distance from the end face is set to a positive angle. It is good to do.
Moreover, in the blade edge exchange-type grooving tool according to the present invention, the distances from the pair of corner portions to the rotation axis in the one cutting edge may be set to be the same.
In the circumferential grooving method according to the present invention, the distances from the pair of corner portions to the rotation axis in the one cutting edge may be set to be the same.
According to the cutting edge-replaceable grooving tool and the circumferential grooving method according to the present invention, the distances from the pair of corner portions to the rotation axis of the work material are set to be the same as each other. The groove bottom of the work material to be cut with one of the cutting edges can be formed parallel 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 other 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.
Moreover, in the circumferential surface grooving method according to the present invention, the corner portion has a convex-curved first corner blade, and the other 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 replaceable grooving tool and the peripheral surface grooving method according to the present invention, the corner portion of the cutting edge has the first corner blade having a convex curve shape, so that the cutting edge chipping at the corner portion, etc. Is prevented.

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 may extend so as to be orthogonal to the rotational axis of the work material when the cutting insert is viewed from a direction orthogonal to the tool virtual plane. Good.
Further, in the circumferential grooving method 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 surface cutting blade. It has two corner blades, and when the cutting insert is viewed from the direction orthogonal to the tool virtual plane, the second corner blade is extended and arranged so as to be orthogonal to the rotation axis of the work material. Also good.

According to the cutting edge-replaceable grooving tool and the circumferential grooving method according to the present invention, the corner portion of the cutting edge includes a central end portion along the extending direction of the insert body in the first corner blade and a side cut. Since the second corner blade connecting the blade extends so as to be orthogonal to the rotation axis of the work material, the groove wall of the work material cut by the front face cutting edge of the one cutting edge and the first corner blade This second corner blade is exposed, and the finishing accuracy of the groove wall is improved.

  According to the cutting edge replaceable grooving tool and the circumferential grooving method according to the present invention, the circumferential grooving is performed along the end surface of the work material without increasing the number of parts of the cutting insert. Can also ensure sufficient machining accuracy.

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. FIG. 2 is a side view of the cutting edge replacement type grooving tool and work material according to the first embodiment of the present invention as viewed from the direction facing the front clearance surface of the cutting insert, and one cutting edge of the cutting insert is It is the figure seen from the front. It is the front view which looked at the blade-tip-exchange-type grooving tool and work material which concern on the 1st Embodiment of this invention from the front end side of the tool main body, and is the figure which looked at the cutting insert from the side surface. The side view which looked at the blade-tip-exchange-type grooving tool which concerns on the 1st Embodiment of this invention from the direction which opposes the front flank of a cutting insert, and the figure which looked at one cutting edge of the cutting insert from the front It is. 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, and is the figure which looked at the cutting insert from the side. It is a perspective view which shows the cutting insert. It is a figure which expands and shows one cutting edge 32A in FIG. It is a figure which expands and shows one cutting edge 32A in FIG. It is a figure which expands and shows the cutting insert 30 and the groove bottom D in FIG. It is a figure which expands and shows one cutting edge 32A and the back surface B in FIG. It is a figure explaining the mounting | wearing attitude | position of the cutting insert 30, and each distance from a pair of corner part 43 in one cutting blade 32A to rotation axis WO. It is the figure which looked at the cutting insert 30 in FIG. 13 from the upper surface of the insert main body 31, and the figure seen from the side surface of the insert main body 31. It is the figure which looked at the cutting insert 30 in FIG. 13 from the front of the insert main body 31. FIG. 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 figure which expands and shows the cutting insert 30 and the groove bottom D in FIG. It is a figure explaining the mounting | wearing attitude | position of the cutting insert 30, and each distance from a pair of corner part 43 in one cutting blade 32A to rotation axis WO. It is the figure which looked at the cutting insert 30 in FIG. 19 from the side surface of the insert main body 31. 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 blade-tip-exchange-type grooving tool (inner diameter grooving) and a 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 grooving) and a 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 A section 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. 1-7 shows the cutting edge exchange-type grooving tool 10 which concerns on the 1st Embodiment of this invention, FIGS. 8-15 is the whole cutting insert 30 used for this cutting-edge-exchange-type grooving tool 10. FIG. Or a part is expanded and shown. The cutting edge-replaceable grooving tool 10 according to the present embodiment includes a tool body 1 that is formed in an axial shape and has 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. It has a cutting insert 30 that is detachably attached to an end portion (tip portion) 3 and projects a cutting edge 32 from the outer peripheral surface 1A of the tool body 1 toward the side.

  The cutting edge exchange-type grooving tool 10 of the present embodiment performs an inner diameter grooving process on a substantially cylindrical work material W. In the work hole H having a cylindrical hole shape in the work material W, an inner face (end face) B formed of a circular plane orthogonal to the rotation axis WO of the work material W is formed in the innermost part. . The inner surface B is adjacent to an inner peripheral surface (circumferential surface) S facing the rotation axis WO side of the processing hole H. 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 surface B. The inner circumference of the machining hole H The surface S 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. A region located on the shank portion 2 on the outer peripheral surface 1A of the tool body 1 is a pair of cutouts that are formed of a belt-like plane extending in parallel to the central axis TO and are opposed to each other across the central axis TO. Surfaces 2A and 2A are formed. The cutting edge-replaceable 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 notch surfaces 2A and 2A. In the present embodiment, the center axis TO extends in the X direction, and the cutout surfaces 2A and 2A are arranged in the XY horizontal plane.

  As shown in FIGS. 3 and 4, the tip 3 of the tool body 1 has a flat surface in which the upper surface 3A is slightly inclined with respect to the notch surface 2A of the shank portion 2, and a pair of notch surfaces 2A, 2A. Of these, it is formed so as to be recessed by one step from the notch surface 2A disposed on the upper surface of the shank portion 2. Further, the lower surface 3 </ b> B at the tip 3 of the tool body 1 is formed such that the cross section perpendicular to the tool axis TO has a convex curve shape and is reduced by one step from the outer diameter of the shank portion 2. In addition, the shape of the upper surface 3A and the lower surface 3B in the front-end | tip part 3 of the tool main body 1 mentioned above is an example, and is not limited to this embodiment.

  Moreover, in the front-end | tip part 3 of the tool main body 1, one side (lower side in FIG. 3) along the direction (vertical direction (Y direction) in FIG. 3) perpendicular | vertical to the center axis line TO and parallel to the notch surfaces 2A and 2A. The facing side surface 3 </ b> C is formed such that a base end portion and a center portion along the center axis line TO are greatly cut out radially inward from the outer diameter of the shank portion 2. Further, the end portion on the distal end side along the central axis TO in the side surface 3C is formed so as to protrude toward the one side from the base end portion and the central portion.

  Specifically, as shown in FIG. 5 and FIG. 7, a portion (lower jaw portion) disposed on the lower side (lower side in FIG. 5 and FIG. 7) of the insert mounting seat 4 described later at the end portion of the side surface 3 </ b> C. ) Protrudes to the one side (the right side in FIGS. 5 and 7) from the portion (upper jaw part) disposed on the upper side (the upper side in FIGS. 5 and 7) of the insert mounting seat 4, The outer diameter of the lower jaw part is set larger than the outer diameter of the shank part 2.

  Further, the tip 3 of the tool body 1 is disposed so as to face away from the side surface 3C with the central axis TO in between, and a side surface 3D facing the other side in the Y direction (upper side in FIG. 3). Is formed. The side surface 3D is formed such that a cross section perpendicular to the tool axis TO has a convex curve shape and is reduced by one step from the outer diameter of the shank portion 2.

  In addition, between the upper surface 3A and the lower surface 3B of the distal end portion 3 of the tool body 1, an insert mounting seat 4 to which the cutting insert 30 is detachably attached opens at the distal end surface of the distal end portion 3 and is side to side surface 3C. It is formed to penetrate through 3D. Specifically, the insert mounting seat 4 has a portion that opens to the side surface 3C in a portion on the tip side along the central axis TO, and is formed in a substantially rectangular parallelepiped hole shape, and from the side surface 3C toward the other side. It extends.

  Moreover, in the part opened to the side surface 3C in the portion on the tip side of the insert mounting seat 4, the top wall surface 4B and the bottom wall surface 4C facing each other up and down are the top surface 3A in the front view of the tool body 1 in FIGS. 12 and is formed in a convex V shape when viewed from the side surface 3C, as shown in FIG. Further, as shown in FIG. 5, in the portion on the distal end side of the insert mounting seat 4, the portion opened to the side surface 3D is the distance between the top wall surface 4D and the bottom wall surface 4E with respect to the portion opened to the side surface 3C. Is narrowly formed and is cut out in a slit shape substantially parallel to the upper surface 3A. Further, the insert mounting seat 4 is formed with a step portion 4A facing the one side by connecting a portion opened to the side surface 3C and a portion opened to the side surface 3D.

  Moreover, the part of the base end side along the central axis TO of the insert mounting seat 4 forms a slit shape and continues to the part on the tip side. Further, a through-hole 5A that opens to the upper surface 3A of the distal end portion 3 and through which the clamp screw 5 is inserted is formed in the top wall surface at the base end side portion of the insert mounting seat 4. In addition, a screw hole (not shown) is formed in the bottom wall surface of the base end side portion of the insert mounting seat 4 so as to be coaxial with the through hole and subjected to female threading on the inner peripheral surface.

  Further, the cutting insert 30 to be mounted on the cutting edge-replaceable grooving tool 10 is made of a hard material such as cemented carbide, and as shown in FIG. 7, the extending direction of the rod-shaped insert body 31 (see FIG. 7). This is a so-called dog bone type cutting insert provided with a pair of cutting edges 32 on the upper surface (the surface facing upward in FIG. 7) of the insert main body 31 at both ends in the left and right direction.

  Here, reference sign C1 shown in FIGS. 8 to 15 and the like indicates an insert longitudinal axis along the extending direction of the insert body 31, and this 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. 12, the cutting insert 30 includes an insert longitudinal axis C1 and an insert height axis C3, and includes an upper surface (a surface facing upward in FIG. 12) and a lower surface (a lower side in FIG. 12) of the insert body 31. The insert virtual plane VS2 passing through the center of each of the facing surfaces is also formed symmetrically (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 FIG. 12, the cutting insert 30 has a central portion in the extending direction on the upper surface of the insert body 31 and a lower surface formed in a concave V shape in a cross section perpendicular to the insert longitudinal axis C1. ing. 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 4 </ b> B and the bottom wall surface 4 </ b> C at a portion opened to the side surface 3 </ b> C of the insert mounting seat 4, and from the one side to the other side. Is inserted.

  As shown in FIG. 7, the cutting insert 30 inserted into the insert mounting seat 4 is positioned by abutting the other end face of the insert body 31 against the stepped portion 4 </ b> A. By tightening the clamp screw 5 in this state, the top wall surfaces 4B and 4D of the insert mounting seat 4 approach each other while being elastically deformed toward the bottom wall surfaces 4C and 4E. The distance from 4E is narrowed, and the cutting insert 30 is fixedly supported on the tip 3 of the tool body 1.

  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. 11, the cutting edge 32 is a linear front cutting edge that is formed at the edge of the insert body 31 in the extending direction and extends in the width direction (left-right direction in FIG. 11) 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.

  7, 8, and 12, the peripheral surface connecting the upper surface and the lower surface of the outer surface of the insert main body 31 has a front flank 51 that is continuous with the front cutting edge 41 and a pair of side cutting edges 42, respectively. A pair of continuous side flank surfaces 52 are 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 (lower side in FIG. 3) of the pair of cutting edges 32, A cutting edge 32B is arranged on the other side (upper side in FIG. 3). Then, one of the cutting edges 32A protrudes from the outer peripheral surface of the tip portion 3 of the tool body 1 toward the side perpendicular to the central axis TO, and is disposed opposite to the inner peripheral surface S of the work material W, The inner peripheral surface S is grooved. Specifically, the tool main body 1 projects one cutting edge 32A of the pair of cutting edges 32 from the outer peripheral surface of the tip portion 3 toward the grooving direction indicated by the symbol YA in the Y direction, and performs cutting. The insert 30 is attached.

  3, 8, and 11, the direction indicated by C <b> 2 </ b> A is the work material in the pair of corner portions 43 </ b> A and 43 </ b> B (43 </ b> C and 43 </ b> D) in the width direction of the insert body 31 (the insert width axis C <b> 2 direction). The other width direction, which is a direction from one corner portion 43A (43C) located on the back surface B side of W to the other corner portion 43B (43D) located on the side opposite to the back surface B side, is shown. . As shown in the front view of the cutting insert 30 in FIGS. 4 and 12 (side view in the tool body 1), the insert width axis C2 of the cutting insert 30 gradually becomes the workpiece W as it goes in the other width direction C2A. It inclines toward the front side of the rotation direction WT.

  That is, in this cutting insert 30, the front cutting edge 41 of one cutting edge 32A is gradually inclined toward the front side in the rotation direction WT of the workpiece W as it goes to the other width direction C2A. Specifically, as shown in FIG. 12, the cutting insert 30 is configured such that the front cutting edge 41 of the cutting edge 32 </ b> A gradually moves forward in the rotational direction WT as it goes from the distal end side to the proximal end side of the tool body 1. It is inclined toward the notch surface 2A located on the lower side of the main body 1, and the front cutting edge 41 is set to a positive (positive) angle. 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 front side.

  In the present embodiment, the front cutting edge 41 of the cutting edge 32A is gradually inclined toward the front side in the rotational direction WT of the work material W as it is separated from the back surface B along the rotation axis WO. Here, what is indicated by reference sign VS3 in FIGS. 5 and 12 represents a virtual tool plane including the corner portion 43B of the cutting edge 32A and the rotation axis WO. In FIG. 12, 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. 5, the direction indicated by the reference symbol C <b> 1 </ b> A is one cutting edge from the other cutting edge 32 </ b> B of the pair of cutting edges 32 </ b> A and 32 </ b> B in the extending direction of the insert body 31 (in the insert longitudinal axis C <b> 1 direction). One extending direction which is a direction toward 32A is shown. As shown in a side view of the cutting insert 30 in FIG. 5 (a front view in the tool body 1), the insert longitudinal axis C1 of the cutting insert 30 gradually approaches the virtual tool plane VS3 toward the one extending direction C1A. Be inclined to be.

  Specifically, as shown in FIG. 5, when viewed from the tip end side of the tool body 1, the insert longitudinal axis C <b> 1 gradually increases toward the one extending direction C <b> 1 </ b> A on the upper surface side of the insert body 31 (the vertical direction in FIG. 5 ( It extends from the upper side in the Z direction) toward the lower surface side (the lower side in the Z direction in FIG. 5) so as to approach the tool virtual plane VS3. Thereby, the front cutting edge 41 of the cutting edge 32B is separated toward the upper surface side (upper side in FIG. 5) of the insert main body 31 with respect to the tool virtual plane VS3. The angle θ3 formed by the insert longitudinal axis C1 passing through the front cutting edges 41 and 41 of the cutting edges 32A and 32B and the tool virtual plane VS3 is set in a range of 0 ° <θ3 ≦ 10 °. In the present embodiment, this θ3 is set to about 7 °, for example.

  As shown in FIG. 7, 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 notch surface 2A located on the lower side of the tool body 1.

  FIG. 3 is a top view of the cutting insert 30 as viewed from a 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 0 ° ≦ It is set within the range of θ1 ≦ 0.5 ° and is mounted on the insert mounting seat 4. In the present embodiment, the θ1 is set to about 0 °. Thereby, in this top view, the angle formed by 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 (= 0 °). In FIG. 3, the angle θ4 formed by the insert longitudinal axis C1 and the rotation axis WO is set within the range of 90 ° <θ4 <91 °. In the present embodiment, this θ4 is set to about 90.4 °. Specifically, the relationship between θ4 and θ1 is set such that 1 °> θ4−90 °> θ1.

  As shown in FIGS. 3 and 11, 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 distal end side (the left side in FIGS. 3 and 11) of the tool body 1 in one cutting edge 32A is more distal than the corner portion 43C located on the distal end side in the other cutting edge 32B. Arranged on the side. In the present embodiment, the corner portion 43C located on the back surface B side in the cutting edge 32B is separated from the back surface B with respect to the corner portion 43A located on the back surface B side in the cutting edge 32A.

  Further, by adjusting the above-described θ1 to θ4, as shown in FIGS. 13 to 15, as shown in FIGS. 13 to 15, the respective distances L <b> 1 from the corner portions 43 </ b> A and 43 </ b> B to the rotation axis WO of the work material W, L2 can also be set to be the same. That is, in the cutting edge 32A, a radius of a virtual circle (distance L1) obtained by rotating the corner portion 43A around the rotation axis WO and a radius of a virtual circle obtained by rotating the corner portion 43B around the rotation axis WO ( The distance L2) may be set to be the same. The outer peripheries of these virtual circles coincide with the end on the back surface B side and the end opposite to the back surface B of the groove bottom D of the groove formed in the work material W, respectively.

  Further, the front cutting edge 41 of the cutting edge 32A has the same distance to the rotation axis WO as the distances L1 and L2 in any part disposed between the corner part 43A and the corner part 43B. Yes. Further, since the distances L1 and L2 can be obtained in advance corresponding to the radius of the groove bottom D to be grooved, the posture of the cutting insert 30 with respect to the work material W is set so as to satisfy these distances L1 and L2. You only have to set it.

  In the present embodiment, the cutting insert 30 of the tool body 1 having the above-described configuration is in a state of being closely arranged so that the corner portion 43A of one cutting edge 32A is in contact with the back surface B of the work material W, The cutting edge 32A is grooved into the inner peripheral surface S by moving in the grooving direction YA toward the radially outer side of the work material W along the back surface B.

  As described above, according to the cutting edge exchange type grooving tool 10 and the peripheral surface grooving method using the same according to the present embodiment, the inner peripheral surface S of the work material W from the tip 3 of the tool body 1. The front cutting edge 41 of one cutting edge 32A of the cutting insert 30 protruding toward the side is made parallel to the insert width axis C2, and the workpiece W is gradually rotated toward the other width direction C2A. Since it is inclined toward the front side of the rotating direction WT and is set to a positive angle with respect to the work material W, the dischargeability of the chips cut by one of the cutting edges 32A is enhanced.

  That is, the front cutting edge 41 of the cutting edge 32A is inclined toward the front side in the rotational direction WT as it goes from the distal end side to the proximal end side of the tool body 1, so that the cutting edge 32A is cut. Chips are discharged toward the base end side of the tool body 1 (the exit direction of the machining hole H on the side opposite to the back surface B). As a result, the chip discharge performance is improved, and it is also possible to prevent chips from coming into contact with the back surface B of the work material W located on the tip end side of the tool body 1 and chip accumulation near the back surface B. As a result, the processing accuracy is improved.

  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 lower surface side of the insert body 31. That is, since the other cutting edge 32B is separated toward the upper surface side of the insert body 31 with respect to the tool virtual plane VS3, the wedge angle β of the one cutting edge 32A (the rake face 33 in FIGS. 5 and 7). And the front flank 51) can be set relatively large. Therefore, the cutting edge strength of one of the cutting edges 32A for grooving the work material W is sufficiently secured.

  Further, according to such a mounting posture of the cutting insert 30, the thickness of the lower jaw portion that supports the cutting insert 30 can be sufficiently secured at the distal end portion 3 of the tool body 1, and the mechanical strength of the distal end portion 3 is ensured. Is increased. Further, it is possible to prevent the front flank 51 connected to the front cutting edge 41 of the cutting edge 32A from being separated from the groove bottom D and coming into contact with the groove bottom D.

  Further, the other cutting edge 32B has a corner portion 43C located on the opposite side to the other width direction C2A, and the other cutting edge 32A has a corner portion 43A located on the opposite side to the other width direction C2A. It is arranged on the C2A side. Accordingly, as in the present embodiment, grooving is performed on the inner peripheral surface S of the processing hole H along the inner surface B of the cylindrical hole-shaped processing hole H formed around the rotation axis WO of the work material W. Even when processing (inner diameter grooving), the corner portion 43C of the other cutting edge 32B is separated from the back surface B, and the corner portion 43C contacts the back surface B and is damaged. Is reliably prevented. Further, the contact prevents the other unused cutting edge 32B from being damaged.

  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 front side of the WT, inclining toward the lower 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 parallel to the rotation axis WO. That is, the angle α of the groove bottom D in FIG. 27 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 back surface B side of the work material W (that is, the other width direction C2A side). The side cutting edge 42 arranged in (1) does not come into contact with the opening edge located on the rotation axis WO side in 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 a 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 0 ° ≦ θ1. ≦ 0.5 ° is set. Accordingly, the angle (θ4-90 °) at which the insert longitudinal axis C1 along the extending direction of the insert main body 31 is inclined with respect to the back surface B of the work material W is approximated to the set value of θ1. Is set to a value slightly larger than θ1. That is, the posture of the cutting insert 30 with respect to the tool body 1 is arranged substantially parallel without causing the extending direction of the insert body 31 (insert longitudinal axis C1) to be substantially inclined with respect to the back surface B of the work material W. However, the corner portion 43C of the other cutting edge 32B can be reliably separated from the back surface B as described above. Therefore, the machining accuracy of the groove bottom D of the work material W that has been grooved is more reliably increased.

  Further, in the inner diameter grooving of the present embodiment, when the distances L1 and L2 from the pair of corner portions 43A and 43B of the one cutting edge 32A to the rotation axis WO of the work material W are set to be the same as each other The groove bottom D of the work material W to be cut with the one cutting edge 32A can be formed in parallel to the rotation axis WO. Therefore, the finishing accuracy of the groove of the work material W is sufficiently ensured.

  In addition, since the angle θ4 formed by the insert longitudinal axis C1 and the rotation axis WO of the workpiece W is set to 90 ° <θ4 <91 ° when viewed from the direction orthogonal to the tool virtual plane VS3, Even when the inner peripheral surface S of the processing hole H is grooved along the inner surface S of the processing hole H using the cutting edge 32A, the corner portion on the rear surface B side of the other cutting edge 32B. 43C is reliably separated from the back surface B, and the processing accuracy of the groove bottom D is sufficiently secured.

  That is, when the angle θ4 is set to 91 ° or more, the side cutting edge 42 disposed on the base end side of the tool body 1 in the one cutting edge 32A is used for forming the deep groove when the deep groove is formed. There is a risk of contact with the opening edge. In addition, the groove bottom D of the groove is relatively inclined with respect to the rotation axis WO, and the groove processing accuracy cannot be ensured.

  As described above, in the inner diameter grooving using the above-described blade edge exchange type grooving tool 10, the depth perpendicular to the rotation axis WO is adjacent to the inner peripheral surface S of the machining hole H formed in the work material W. Even if the surface B is formed, high-precision inner diameter grooving can be performed regardless of the position of the inner peripheral surface S to be grooved.

(Second Embodiment)
Next, the blade edge exchange 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-replaceable grooving tool 20 of this embodiment is formed in an axial shape, and is detachably attached to a tool body 1 having a substantially rectangular cross section and a tip 3 of the tool body 1. It has the above-mentioned cutting insert 30 which makes the cutting-blade 32A protrude toward the front end side from the front end surface 1B. That is, the cutting edge replacement type grooving tool 20 of the present embodiment is arranged so that the insert longitudinal axis C <b> 1 of the cutting insert 30 is along the extending direction of the tool body 1. The tool body 1 has a cutting insert 30 arranged along one side surface 3E facing the side opposite to the other width direction C2A among both side surfaces facing the side (X direction in FIG. 17) at the tip portion 3. doing. As shown in FIG. 17, the tool body 1 is disposed along the Y direction so as to extend substantially perpendicular to the rotation axis WO of the work material W when viewed from a direction orthogonal to the tool virtual plane VS3. The one cutting edge 32A protrudes in the grooving direction YA.

  This cutting edge exchange-type grooving tool 20 moves the cutting edge 32A in the grooving direction YA along the stepped portion U of the work material W formed in a multi-stage columnar shape, so that the rotation axis WO of the work material W The outer peripheral surface (circumferential surface) R facing the opposite side is subjected to grooving (outer diameter grooving). The stepped portion U of the work material W is formed with an end surface E which is an annular surface which is adjacent to the small diameter portion of the outer peripheral surface R and which is orthogonal to the rotation axis WO. Specifically, in the present embodiment, the cutting insert 30 is placed along the end surface E in a state where the cutting insert 30 is disposed close to the corner portion 43A of the one cutting edge 32A so as to contact the end surface E of the work material W. The cutting edge 32A moves in the grooving direction YA toward the inside in the radial direction of the work material W, and grooving the small diameter portion of the outer peripheral surface R. In the present embodiment, the rotation direction WT of the work material W is set opposite to that in the first embodiment.

  In the cutting edge exchange type grooving tool 20 of the present embodiment, of the pair of corner portions 43A and 43B of one cutting edge 32A, the corner portion 43B located on the other width direction C2A side is in relation to the corner portion 43A. The workpiece W is arranged on the front side in the rotation direction WT. That is, in this cutting insert 30, the front cutting edge 41 of one cutting edge 32A is parallel to the insert width axis C2, and the rotation direction WT of the workpiece W gradually increases toward the other width direction C2A. It is inclined toward the front side. Specifically, the front cutting edge 41 of the cutting edge 32A is directed from the one side surface 3E side of the tool body 1 to the other side surface 3F side facing the side opposite to the one side surface 3E (that is, the other width direction C2A side). The front cutting edge 41 is set to a positive (positive) angle with an inclination toward the front side in the rotational direction WT as it goes. In the present embodiment, the front cutting edge 41 of the cutting edge 32A is gradually inclined toward the front side in the rotational direction WT of the work material W as it is separated from the end surface E along the rotation axis WO.

  Further, as shown in a side view of the cutting insert 30 in FIG. 20 (side view also in the tool body 1), the insert longitudinal axis C1 of the cutting insert 30 gradually increases in the direction of the one extending direction C1A. It inclines so that it may approach tool virtual plane VS3 toward the lower surface side (lower side of the up-down direction (Z direction) in FIG. 20). Thereby, the front cutting edge 41 of the cutting edge 32B is spaced apart from the tool virtual plane VS3 toward the upper surface side of the insert main body 31 (upper side in the Z direction in FIG. 20).

  Then, as shown in FIGS. 17 and 18, 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 3E side (left side in FIGS. 17 and 18) of the tool body 1 in the one cutting edge 32A is more than the corner portion 43C located on the one side 3E side in the other cutting edge 32B. Is also disposed on the side surface 3E side. In the present embodiment, the corner portion 43C located on the end surface E side in the cutting edge 32B is separated from the end surface E with respect to the corner portion 43A located on the end surface E side in the cutting edge 32A.

  In addition, the angles θ1 to θ4 in the blade edge replaceable grooving tool 20 are respectively set to the same numerical ranges as the angles θ1 to θ4 in the blade edge replaceable grooving tool 10 described above.

  According to the cutting edge replaceable grooving tool 20 according to the present embodiment, the outer peripheral surface of the work material W along the end surface E perpendicular to the rotation axis WO in the stepped portion U of the work material W having a multistage cylindrical shape. Even when grooving (outer diameter grooving) is performed on R, the radius φd1 / 2 of the large diameter portion of the work material W in FIG. 17 and the corner portion 43C of the other cutting edge 32B to the rotation axis WO Regardless of the relationship (large or small) with respect to the distance L3, it is ensured that the corner portion 43C of the cutting edge 32B is separated from the end surface E, and the corner portion 43C contacts the end surface E and is damaged. Is prevented. Further, the contact prevents the other unused cutting edge 32B from being damaged.

  Further, since the front cutting edge 41 of one cutting edge 32A is set to the positive angle as described above, the chips cut by the cutting edge 32A are on the other side 3F side (opposite to the end face E) of the tool body 1. Toward the small diameter portion on the side). As a result, the chip discharge performance is improved, and it is also possible to prevent chips from coming into contact with the end surface E of the work material W located on the one side surface 3E side of the tool body 1 and from generating chips in the vicinity of the end surface E. As a result, the processing accuracy is improved.

  As described above, in the outer diameter grooving using the above-described blade edge replacement grooving tool 20, the end face E perpendicular to the rotation axis WO is formed adjacent to the small diameter portion of the outer peripheral surface R of the work material W. Even if it is, the outer diameter grooving with high accuracy can be performed regardless of the position of the outer peripheral surface R to be grooved.

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. 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 43B of the one cutting edge 32A is directed from the extension line VL1 of the front cutting edge 41 adjacent to the corner portion 43B 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 orthogonal to the rotation axis WO of the work material W, and extends to the back surface B or the end surface E. It is formed so as to extend in parallel. 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 peripheral surfaces S and R along the end surfaces B and E of the work material W. However, the present invention is not limited to this. is not. For example, the peripheral surfaces S and R separated from the end surfaces B and E of the work material W may be grooved. According to the embodiment of the present invention, even if any of the peripheral surfaces S and R adjacent to the end surfaces B and E of the work material W or the separated peripheral surfaces S and R is grooved, high accuracy is achieved. Can be cut.

DESCRIPTION OF SYMBOLS 1 Tool main body 1A Outer peripheral surface of a tool main body 1B Tip end surface 3 Tip end 3E One side surface 3F Other side surface 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 portion 43A One cutting edge located on the opposite side of the other width direction C2A in one cutting edge 43B The other corner located on the other width direction C2A side in one cutting edge Part 43C One corner part 43D located on the opposite side to the other width direction C2A in the other cutting edge 43D The other corner part 44 located on the other width direction C2A side in the other cutting edge 44 First corner edge 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 surface L1 Distance from one corner located on the opposite side of the other width direction C2A to the rotation axis in one cutting edge L2 From the other corner located on the other width direction C2A side in one cutting edge Distance to rotation axis 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)
TO Central axis VL1 of tool body Extension line of front cutting edge VL2 Perpendicular line extending from outer edge of first corner blade toward extension line VL1 VS1 Insert virtual plane VS3 Tool virtual plane W Work material WO Rotation axis of work material WT Rotation direction of work material YA Groove direction
Z Vertical direction θ1 Angle formed by the insert width axis and the rotation axis of the work material θ2 Angle formed by the front cutting edge (or insert width axis) of one cutting edge and the virtual tool plane

Claims (17)

A cutting insert having a cutting edge protruding toward the peripheral surface of the work material rotating about the rotation axis, and a tool body having a shaft shape and having the cutting insert detachably attached to the tip. And a cutting edge exchange type grooving tool for grooving the peripheral surface 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 one cutting edge of the pair of cutting edges protruding toward the grooving direction, and the cutting insert is mounted,
The cutting insert is disposed on the tool body so as to be along a tip surface facing the tip side of the tool body,
The grooving direction is a direction away from the center axis of the tool body,
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, and the other corner from one corner portion located on the tip end side of the tool main body in the pair of corner portions in the width direction. Gradually inclines toward the lower side of the tool body as it goes in the other width direction, which is the direction toward the part,
An 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 a virtual tool plane including the other corner portion of the one cutting edge and perpendicular to the vertical direction of the tool body. And, in the extending direction, gradually approach the tool virtual plane as it goes from the other cutting edge of the pair of cutting edges toward the one cutting edge. Extending toward the underside of the tool body ,
One corner portion located on the opposite side 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 , and
The one corner portion located closer to the tip side of the tool body than the other corner portion of the other cutting edge is located closer to the tip side of the tool body than the other corner portion of the one cutting edge. The blade edge exchange type grooving tool is arranged on the base end side of the tool main body with respect to the one corner portion .   A cutting insert having a cutting edge protruding toward the peripheral surface of the work material rotating about the rotation axis, and a tool body having a shaft shape and having the cutting insert detachably attached to the tip. And a cutting edge exchange type grooving tool for grooving the peripheral surface 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 one cutting edge of the pair of cutting edges protruding toward the grooving direction, and the cutting insert is mounted,
  The cutting insert is arranged on the tool body so as to be along one side surface facing the side of the tool body,
  The grooving direction is a direction toward the tip side of the tool body,
  The cutting insert is
  One corner portion located in a direction in which the insert width axis passing through the center in the extending direction of the insert body and extending along the width direction is separated from the center axis of the tool body in the pair of corner portions. Gradually inclines toward the lower side of the tool body as it goes in the other width direction, which is the direction from the other corner portion,
  An 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 a virtual tool plane including the other corner portion of the one cutting edge and perpendicular to the vertical direction of the tool body. And, in the extending direction, gradually approach the tool virtual plane as it goes from the other cutting edge of the pair of cutting edges toward the one cutting edge. Extending toward the underside of the tool body,
  One corner portion located on the opposite side 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, and
  The one corner portion located in a direction away from the central axis of the tool body from the other corner portion of the other cutting edge is closer to the central axis than the other corner portion of the one cutting edge. The blade edge exchange type grooving tool, which is arranged in a direction approaching the central axis with respect to the one corner portion located in the separating direction. It is a blade exchange type grooving tool according to claim 1 or 2 ,
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 imaginary plane is set to 0 ° ≦ θ1 ≦ 0.5 °. Replaceable grooving tool. It is a blade exchange type grooving tool according to claim 1 or 3 ,
The peripheral surface is an inner peripheral surface facing the rotation axis side of the work material,
The one cutting edge is subjected to an inner diameter grooving process with respect to the inner peripheral surface. It is a blade exchange type grooving tool according to claim 4 ,
The tool body protrudes the one cutting edge from the outer peripheral surface of the tip portion to the side,
The cutting insert is set to a positive angle, with the front cutting edge of the one cutting edge being gradually inclined toward the lower side of the tool body as it goes from the distal end side to the proximal end side of the tool body. An edge-changing grooving tool characterized by It is a blade exchange type grooving tool according to claim 2 or 3 ,
The peripheral surface is an outer peripheral surface facing the opposite side of the rotation axis of the work material,
The one of the cutting edges is an outer diameter grooving process with respect to the outer peripheral surface. It is a blade exchange type grooving tool according to claim 6,
In the tool body, the cutting insert is arranged along one side surface facing the side of the tool body, and the one cutting edge is projected from the tip surface of the tip part toward the tip side. And
The cutting insert gradually moves toward the lower side of the tool body as the front cutting edge of the one cutting edge is directed from the one side surface to the other side surface facing the side opposite to the one side surface. An edge-changing grooving tool that is inclined and set to a positive angle.   It is a cutting edge exchange type grooving tool according to any one of claims 1 to 7,
  The distance between the pair of corner portions and the rotation axis of the one cutting edge is set to be the same as each other, and the blade edge exchange type grooving tool is characterized. It is a blade exchange type grooving tool according to any one of claims 1 to 8 ,
The corner portion has a convex curved first corner blade,
The other 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 9 ,
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,
The cutting edge replacement type grooving characterized in that the second corner blade extends so as to be orthogonal to the rotation axis of the work material when the cutting insert is viewed from a direction orthogonal to the tool virtual plane. tool. A cutting insert having a cutting edge projecting toward a peripheral surface of a work material rotating about a rotation axis; and a tool body having a shaft shape, the cutting insert being detachably mounted at a tip portion. A peripheral grooving method for grooving the peripheral surface of the work material with the cutting edge using a blade exchange type grooving tool,
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 mounted on the tool body with one of the pair of cutting edges projecting in the grooving direction, and the one cutting edge is moved along the grooving direction. When grooving the peripheral surface by
The other width that is the direction from one corner portion to the other corner portion of the pair of corner portions in the width direction, with the insert width axis passing through the center in the extending direction of the insert body and extending along the width direction. Inclined toward the front side in the rotational direction of the work material rotating gradually toward the direction,
The insert longitudinal axis extending along the extending direction through the center in the width direction of the insert main body is inclined with respect to a tool virtual plane including the other corner portion of the one cutting edge and the rotation axis, and the extension Of the pair of cutting edges to the front side in the rotational direction so as to gradually approach the tool imaginary plane as one direction extends from the other cutting edge to the one cutting edge. Extend towards
The peripheral surface of the work material is an inner peripheral surface facing inward in the radial direction perpendicular to the rotation axis,
Of the work material, the one corner portion of the other cutting edge with respect to an end surface that rises inward in the radial direction adjacent to the inner peripheral surface and is perpendicular to the rotation axis. Is disposed at a distance from the one corner portion cut into the inner circumferential surface along the end surface of the one cutting edge .   A cutting insert having a cutting edge projecting toward a peripheral surface of a work material rotating about a rotation axis; and a tool body having a shaft shape, the cutting insert being detachably mounted at a tip portion. A peripheral grooving method for grooving the peripheral surface of the work material with the cutting edge using a blade exchange type grooving tool,
  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 mounted on the tool body with one of the pair of cutting edges projecting in the grooving direction, and the one cutting edge is moved along the grooving direction. When grooving the peripheral surface by
  The other width that is the direction from one corner portion to the other corner portion of the pair of corner portions in the width direction, with the insert width axis passing through the center in the extending direction of the insert body and extending along the width direction. Inclined toward the front side in the rotational direction of the work material rotating gradually toward the direction,
  The insert longitudinal axis extending along the extending direction through the center in the width direction of the insert main body is inclined with respect to a tool virtual plane including the other corner portion of the one cutting edge and the rotation axis, and the extension Of the pair of cutting edges to the front side in the rotational direction so as to gradually approach the tool imaginary plane as one direction extends from the other cutting edge to the one cutting edge. Extend towards
  The peripheral surface of the work material is an outer peripheral surface facing outward in the radial direction perpendicular to the rotation axis,
  Of the work material, the one corner portion of the other cutting edge is raised with respect to an end surface that rises toward the outside in the radial direction adjacent to the outer peripheral surface and is perpendicular to the rotation axis. The circumferential grooving method according to claim 1, wherein the circumferential grooving method is arranged apart from the one corner portion cut into the outer peripheral surface along the end surface of the one cutting edge.   A circumferential grooving method according to claim 11 or 12,
  An angle θ1 formed by the insert width axis and the rotation axis is set to 0 ° ≦ θ1 ≦ 0.5 ° when the cutting insert is viewed from a direction orthogonal to the tool virtual plane. Grooving method.   It is a peripheral surface grooving processing method as described in any one of Claims 11-13,
  The circumferential grooving method according to claim 1, wherein the front cutting edge of the one cutting edge is gradually inclined toward the front side in the rotational direction as it is separated from the end face, and is set to a positive angle.   It is a peripheral surface grooving processing method as described in any one of Claims 11-14,
  The circumferential grooving method according to claim 1, wherein distances from the pair of corner portions to the rotation axis of the one cutting edge are set to be the same.   A circumferential grooving method according to any one of claims 11 to 15,
  The corner portion has a convex curved first corner blade,
  The other 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 circumferential surface grooving method according to claim 1, wherein the intersection point is arranged on the tool virtual plane.   The peripheral surface grooving method according to claim 16,
  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,
  The circumferential grooving is characterized in that the second corner blade is extended so as to be orthogonal to the rotation axis of the work material when the cutting insert is viewed from a direction orthogonal to the tool virtual plane. Processing method.

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