WO2011122676A1 - Cutting insert and cutting tool with interchangeable cutting point - Google Patents

Abstract

Disclosed is a cutting insert equipped with a polygonal-plate insert body (1) containing a pair of polygonal surfaces (2) and a multitude of lateral faces (3, 4). The insert body (1) is shaped so as to possess front-back inversion symmetry, a pair of level contact surfaces (8) are formed on each polygonal surface (2), and each contact surface (8) is capable of abutting one of a pair of surfaces to be contacted (19) formed on an underside (14) of an insert mount (13). Two imaginary extended surfaces extending from the pair of contact surfaces (8) intersect in a cross-sectional inverted V shape at an intersecting ridgeline (L). Among the lateral faces of the insert body (1), abutting parts are formed on the long lateral faces (3) which face one of the two directions in which the ridge line (L) extends, which can abut parts to be abutted formed on one wall surface (15) of the insert mount.

Description

Cutting insert and cutting edge changeable cutting tool

The present invention relates to a clamping mechanism for a cutting insert, and more particularly, to a cutting insert that is detachably attached to a cutting edge exchanging cutting tool used for a turning process, and a cutting edge exchanging cutting tool to which the cutting insert is attached.
This application claims priority on March 30, 2010 based on Japanese Patent Application No. 2010-078990 filed in Japan, the contents of which are incorporated herein by reference.

As a cutting insert attached to a cutting edge exchangeable cutting tool for turning, and a cutting edge exchangeable cutting tool to which the cutting insert is attached, for example, one described in Patent Document 1 (Japanese Patent Laid-Open No. 2004-284010) is disclosed. Are known. The cutting insert of patent document 1 has a rectangular plate-shaped insert main body, and the cutting edge is formed in the side ridge part of a pair of rectangular surface of an insert main body. Of the pair of rectangular surfaces, a groove extending in the direction of one diagonal A is formed on the first rectangular surface, and descends from the two corners positioned on the other diagonal B toward the groove. Each slope is formed.

The second rectangular surface is formed with grooves extending in the diagonal B direction of the first rectangular surface when seen from the first rectangular surface side, and from two corners arranged in the diagonal A direction. A slope that descends toward the groove is formed. That is, the insert body has a shape that is twisted around two axes that are orthogonal to the center line connecting the centers of the first and second rectangular surfaces and orthogonal to the side surfaces of the four insert bodies. Has been.

This cutting insert is detachably attached to an insert mounting seat formed on the tool body of the cutting edge exchange type cutting tool. The bottom surface of the insert mounting seat faces the tool rotation direction, and the shape of the bottom surface is a support surface complementary to the first rectangular surface, and the first rectangular surface is supported by the bottom surface. Also, two side surfaces of the insert body intersecting with the groove of the first rectangular surface are supported by two flat wall surfaces facing the tool body front end side and the outer peripheral side of the insert mounting seat.

By the way, since the cutting insert of this patent document 1 is supported and attached to the two support surfaces of the insert mounting seat in this way, for example, it faces the tool body front end side of the insert mounting seat. The support surface of the wall surface needs an area sufficient to support the side surface of the insert body. Furthermore, a thickness necessary for receiving the cutting load in the rotation axis direction acting on the insert main body must be secured on the rear end side of the support surface in the tool main body.

However, when the area of the support surface facing the front end side of the insert mounting seat is increased in this way and a sufficient thickness is secured in the tool body on the rear end side, for example, the rear end side of the insert mounting seat is large. Chip pockets cannot be formed to improve chip discharge. In addition, even if it is attempted to mount a cutting insert by forming a plurality of insert mounting seats facing one chip discharge groove, a sufficient interval must be ensured between adjacent insert mounting seats. One cutting edge row must be formed by the plurality of cutting inserts of the plurality of chip discharge grooves, resulting in a reduction in processing efficiency.

On the other hand, in the cutting insert described in Patent Document 1, a sufficient area is required for the support surface of the insert mounting seat facing the outer peripheral side of the tool body, and the tool radial direction acting on the insert body is provided on the inner peripheral side of the tool body. A wall thickness that can handle the cutting load must be secured. For this reason, a large chip pocket cannot be formed on the inner peripheral side of the insert mounting seat. In particular, in a very small diameter cutting edge exchangeable cutting tool, if a plurality of insert mounting seats are formed in the circumferential direction, a sufficient thickness cannot be ensured. Therefore, only one cutting insert can be attached in the circumferential direction, and it is not possible to avoid a decrease in machining efficiency.

JP 2004-284010 A

The present invention is made under such a background, and there is no need for a plurality of support surfaces on the wall surface of the insert mounting seat, so that the insert mounting seat rear side and inner peripheral side of the cutting edge exchangeable cutting tool can be provided. The purpose of the present invention is to provide a cutting insert capable of improving chip efficiency by forming a large chip pocket and improving chip discharging performance, and by attaching more cutting inserts in the rotation axis direction and circumferential direction of the tool body. It is said. Moreover, this invention aims at providing the blade-tip-exchange-type cutting tool which attached the said cutting insert.

The cutting insert according to one aspect of the present invention is a cutting insert that is detachably attached to an insert mounting seat of a cutting edge exchangeable cutting tool, and includes any one of the following configurations.

(1) A cutting insert that is detachably attached to an insert mounting seat of a cutting edge exchangeable cutting tool,
A polygonal plate-like insert body having a pair of polygonal surfaces and a plurality of side surfaces arranged around the polygonal surfaces,
A cutting edge is formed on the side ridge of the polygonal surface,
The insert body is a reverse-inverted symmetrical shape with respect to the pair of polygonal surfaces,
The pair of polygonal surfaces is a seating surface on which the other polygonal surface is seated on the bottom surface of the insert mounting seat when one of the polygonal surfaces is a rake face,
A contact surface that is a pair of flat surfaces is formed on each of the pair of polygonal surfaces,
The pair of abutment surfaces can abut against a pair of abutment surfaces formed on the bottom surface of the insert mounting seat when the one polygonal surface is the seating surface,
The two virtual extension surfaces obtained by extending the pair of contact surfaces intersect each other at a crossing ridgeline in a cross-section V shape or a cross-section inverted V shape,
Of the side surfaces of the insert body, the side surface of the pair of contact surfaces facing one direction out of the two directions in which the intersecting ridgeline of the virtual extension surface extends rises with respect to the bottom surface of the insert mounting seat 1 An abutting portion that can abut against the abutted portions formed on the two wall surfaces is formed.

(2) In the above (1), the insert main body has a shape that is 180 ° rotationally symmetric with respect to the center line of the pair of polygonal surfaces,
The insert main body is placed on the center line on the other one side surface with respect to one polygonal surface facing the other direction of the direction in which the intersecting ridgeline of the virtual extension surface of the pair of contact surfaces extends. Another contact portion that can contact the contacted portion when rotated 180 ° around is formed.

(3) In the above (2), each of the polygonal surfaces of the insert body has a rectangular shape,
The insert body has a pair of long side surfaces arranged on opposite sides and a pair of short side surfaces arranged on opposite sides,
A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface,
The main cutting edge is inclined so as to gradually recede in the thickness direction from one corner portion to the other corner portion when viewed from the side facing the long side surface.

(4) In the above (3), the pair of contact surfaces are formed on the inside of the polygonal surface.

(5) In the above (3) or (4), the intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the long side surface when viewed from the direction facing the polygonal surface, The contact portion is formed on the long side surface.

(6) In the above (5), the two virtual extension surfaces obtained by extending the pair of contact surfaces on each of the polygonal surfaces intersect with each other in an inverted V-shaped cross section at the intersecting ridgeline.

(7) In the above (5), the intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction obliquely intersecting the long side surface when viewed from the direction facing the polygonal surface.

(8) In the above (7), the intersecting ridge line is formed in a direction intersecting with a diagonal line of the one corner portion on the polygonal surface when viewed from the direction facing the polygonal surface. .

(9) In the above (2), the polygonal surface of the insert main body has a parallelogram shape having a pair of obtuse corner portions and a pair of acute corner portions,
Corner blades are respectively formed at the acute corner portions of the polygonal surfaces,
A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface,
The main cutting edge is inclined so as to gradually recede in the thickness direction from the acute corner portion to the obtuse corner portion when viewed from the side facing the long side surface,
The intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the long side surface as viewed from the direction facing the polygonal surface. The parallelogram includes a rectangle.

(10) In the above (9), the intersection ridgeline of the virtual extension surface of the pair of contact surfaces is closer to the obtuse corner portion than the acute corner portion when viewed from the direction facing the polygonal surface. , Extending in a direction crossing the long side surface.

(11) In the above (3) or (4), the intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the short side surface when viewed from the direction facing the polygonal surface, The contact portion is formed on the short side surface.

(12) In the above (11), the two virtual extension surfaces obtained by extending the pair of contact surfaces on each of the polygonal surfaces intersect with each other in a V-shaped cross section at the intersecting ridgeline.

(13) In the above (11), the intersecting ridgeline of the virtual extension surface of the pair of contact surfaces extends in a direction obliquely intersecting the short side surface when viewed from the direction facing the polygonal surface.

(14) In the above (13), the intersecting ridge line is formed in a direction intersecting with a diagonal line of the one corner portion on the polygonal surface when viewed from the direction facing the polygonal surface. .

(15) In the above (2), the polygonal surface of the insert body has a parallelogram shape having a pair of obtuse corner portions and a pair of acute corner portions,
Corner blades are respectively formed at the acute corner portions of the polygonal surfaces,
A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface,
The main cutting edge is inclined so as to gradually recede in the thickness direction from the acute corner portion to the obtuse corner portion when viewed from the side facing the long side surface,
The intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction intersecting the short side surface as viewed from the direction facing the polygonal surface. The parallelogram includes a rectangle.

(16) In the above (15), the intersecting ridge line of the virtual extension surface of the pair of contact surfaces is closer to the obtuse corner portion than the acute corner portion when viewed from the direction facing the polygonal surface. , Extending in a direction intersecting the short side surface.

(17) In any one of the above (1) to (16), the contact portion is a concave groove having a concave cross section formed on the side surface, and the concave groove is formed between the pair of polygonal surfaces. And is capable of coming into contact with the abutted portion having a convex cross-sectional shape formed on one wall surface of the insert mounting seat.

(18) A cutting edge exchangeable cutting tool,
A tool body rotated about an axis,
The cutting insert according to any one of (1) to (17), which is detachably attached to the outer periphery of the tool body,
In the tool body, one or more insert mounting seats are formed with the bottom surface facing the tool rotation direction and the one wall surface facing the outer peripheral side or the axial direction front end side,
On the bottom surface of the insert mounting seat, a pair of the abutted surfaces that abut against the abutting surface of the cutting insert is formed, respectively.
The two virtual extension surfaces obtained by extending the pair of contacted surfaces intersect each other at an intersecting ridge line in a cross-section inverted V shape or a cross-section V shape complementary to the contact surface of the cutting insert,
A cutting edge, wherein the one wall surface of the insert mounting seat is formed with a contacted portion that contacts the contact portion of the cutting insert at a position where the intersecting ridge line of the contacted surface is directed. Replaceable cutting tool.

In the cutting insert or the cutting edge exchange type cutting tool having the above-described configuration, when one of the pair of polygonal surfaces of the insert body is used as a seating surface as described above, the cross-section V-shaped formed on the bottom surface of the insert mounting seat or A pair of abutting surfaces extending along a virtual extension surface intersecting the reverse V-shaped cross-section are formed on the seating surface of the insert, and a pair of contact surfaces extending along the virtual extension surface intersecting the reverse V-shape. The contact surface is brought into contact. Therefore, the insert main body is allowed to move along the abutted surface in the direction along the intersecting ridge line of the virtual extension surface of the pair of abutting surfaces, but the movement is restricted in other directions.

One side surface of the insert main body is formed on one wall surface of the insert mounting seat with respect to one polygonal surface facing one direction in the direction in which the intersecting ridgelines of the virtual extension surfaces of the pair of contact surfaces extend. Since the abutment part that can abut against the abutted part is formed, the abutment part abuts against the abutted part by pressing the insert body in this direction and attaching it to the insert mounting seat. The insert body is also restrained in the direction of the intersecting ridgeline and is fixed to the insert mounting seat. That is, the insert body is fixed by the abutted surface of the bottom surface of the insert mounting seat and the abutted portion of one insert mounting seat wall surface, and no other wall surface is required.

Therefore, when the wall surface on which the abutted portion is provided is arranged on the inner peripheral side of the tool body on the bottom surface of the insert mounting seat, the wall surface on the rear end side of the tool body can be reduced, or the tool body on the rear end side of the wall surface The wall thickness can be reduced, or in some cases, the wall surface itself can be made unnecessary. For this reason, it becomes possible to attach many cutting inserts by forming a large chip pocket on the tool body rear end side of the insert mounting seat or by forming the next insert mounting seat close to the axial direction. .

On the other hand, when the wall surface on which the abutted part is provided is arranged on the tool body rear end side of the insert mounting seat, the wall surface on the inner peripheral side of the tool body is conversely reduced, or the tool body on the inner peripheral side of this wall surface The wall thickness can be reduced, or in some cases, the wall surface itself can be made unnecessary. Accordingly, the insert pocket on the inner peripheral side of the insert mounting seat is enlarged, or even a cutting tool with a very small diameter can be installed with a plurality of insert mounting seats in the circumferential direction to mount more cutting inserts. be able to.

Moreover, in the cutting insert of the said structure, the insert main body is made into the front-and-back inversion symmetrical shape, The above-mentioned one side surface which faces one direction among the said cross ridgeline directions of the contact surface about each of a pair of front and back polygon surfaces A contact portion is formed, and therefore, by reversing the insert body and reattaching it to the insert mounting seat, these polygonal surfaces are alternately raked and seated, respectively, at least twice with one insert body, It is possible to use a cutting blade formed on a side ridge portion of a polygonal surface which is a rake face.

Further, the insert main body is also 180 ° rotationally symmetric with respect to the center line of the pair of polygonal surfaces, and is directed to the other direction among the directions in which the intersecting ridgelines of the virtual extension surfaces of the pair of contact surfaces extend. Again with respect to the polygonal surface, another side surface, that is, the side surface opposite to the one side surface facing the one direction, is moved to the contacted portion when the insert body is rotated 180 ° around the center line. By forming other abutting portions that can abut, it is possible to use the cutting blade four times in total, two times on one polygonal surface.

For example, if the insert body has a rectangular plate shape having a pair of long side surfaces and a pair of short side surfaces arranged on opposite sides of each other, the cutting blade formed at the intersection ridge line portion between the long and short side surfaces and the square surface Can be used at least four times in one insert body. A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface, and when the main cutting edge is viewed from the side facing the long side surface, from one corner to the other When tilted so as to gradually recede in the thickness direction over the corner, the polygonal surface is complicatedly twisted because the height in the thickness direction of one corner and the other is different. Even if the insert is composed of such a polygonal surface twisted in a complicated manner, the above functions can be achieved by forming a pair of abutment surfaces on the polygonal surface. Can do.

Further, for example, by forming the pair of contact surfaces on the inside of the polygonal surface, it is possible to form a positive rake surface along the cutting edge of the contact surface and the side ridge portion of the polygonal surface. It becomes. Moreover, since an outer peripheral part does not contact | abut to an insert mounting seat, damage to a cutting blade and a positive rake face can also be prevented at the time of insert mounting.

The intersecting ridge line of the virtual extension surface of the pair of contact surfaces may extend in a direction obliquely intersecting the long side surface or the short side surface. If the intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction obliquely intersecting the long side surface, the contact portion is formed on the long side surface facing the intersecting ridge line direction, and the pair of contact surfaces If the intersecting ridgeline of the virtual extension surface of the surface extends in a direction obliquely intersecting the short side surface, the contact portion is formed on the short side surface.

In particular, when the main cutting edge is inclined so as to gradually recede in the thickness direction from one corner portion to the other corner portion when viewed from the side facing the long side surface, A corner blade is formed only in one corner, but when viewed from the direction facing the polygonal surface, the intersecting ridge line is directed in a direction intersecting the diagonal line of the one corner in the polygonal surface. In this case, the intersecting ridge line is separated from one corner portion, and the shape design of the positive rake face of the corner blade and the positive main cutting edge in the vicinity of the corner blade becomes easy.

The abutting portion may be configured such that the entire side surface of the insert body comes into contact with the one wall surface of the insert mounting seat, and the side surface partially contacts the wall surface. May be. Further, on this side surface, a concave groove having a cross-sectional concave shape extending between the pair of polygonal surfaces is formed as an abutting portion, and this is formed into a convex curved shape on the one wall surface of the insert mounting seat. In this case, even if the molding accuracy of the insert main body is not so high, the concave groove having a concave cross section formed by the abutting section is cross-sectioned. The insert body can be reliably supported by abutting at least line contact with the convex curved contacted portion.

As described above, according to the cutting insert and the cutting edge-exchangeable cutting tool of the present invention, a large chip pocket can be secured on the tool body rear end side or inner peripheral side of the insert mounting seat. In addition to being able to improve, it is possible to increase the number of cutting inserts that can be attached in the direction of the rotation axis or the circumferential direction of the tool body, thereby promoting efficient cutting.

It is a perspective view of the cutting insert of the 1st Embodiment of this invention. It is a top view of embodiment shown in FIG. It is a side view of embodiment shown in FIG. It is a front view of embodiment shown in FIG. It is the side view which looked at embodiment shown in FIG. 2 from the arrow Y direction. FIG. 3 is a ZZ sectional view in FIG. 2. It is a perspective view which shows 1st Embodiment of the blade-tip-exchange-type cutting tool of this invention which attached the cutting insert of 1st Embodiment. FIG. 8 is an enlarged perspective view of the tip end of the tool body with the cutting insert of the embodiment shown in FIG. 7 removed. It is a perspective view of the cutting insert of the 2nd Embodiment of this invention. FIG. 10 is a plan view of the embodiment shown in FIG. 9. FIG. 10 is a side view of the embodiment shown in FIG. 9. It is a front view of embodiment shown in FIG. It is the side view which looked at embodiment shown in FIG. 10 from the arrow Y direction. It is ZZ sectional drawing in FIG. It is a perspective view which shows 2nd Embodiment of the blade-tip-exchange-type cutting tool of this invention which attached the cutting insert of 2nd Embodiment. FIG. 16 is an enlarged perspective view of the distal end portion of the tool body with the cutting insert of the embodiment shown in FIG. 15 removed. It is a perspective view of the cutting insert of the 3rd Embodiment of this invention. It is a top view of embodiment shown in FIG. FIG. 18 is a side view of the embodiment shown in FIG. 17. It is a front view of embodiment shown in FIG. It is the side view which looked at embodiment shown in FIG. 18 from the arrow Y direction. FIG. 19 is a ZZ sectional view in FIG. 18. It is a perspective view which shows 3rd Embodiment of the blade-tip-exchange-type cutting tool of this invention which attached the cutting insert of 3rd Embodiment. FIG. 24 is an enlarged perspective view of the tip end of the tool body with the cutting insert of the embodiment shown in FIG. 23 removed.

FIGS. 1 to 6 show a first embodiment of the cutting insert of the present invention, and FIG. 7 shows a first embodiment of the cutting edge replaceable cutting tool of the present invention to which the cutting insert of the first embodiment is attached. Indicates. Furthermore, FIG. 8 shows a state in which the cutting insert is removed from the cutting edge exchangeable cutting tool of the first embodiment.
The cutting insert of this embodiment has an insert body 1. The insert body 1 is formed in a substantially parallelogram plate shape by a hard material selected from cemented carbide, cermet, surface-coated cemented carbide, surface-coated cermet, and the like, and includes a pair of parallelogram surfaces 2, A pair of long side surfaces 3 and a pair of short side surfaces 4 are provided. The insert body 1 in this example has a parallelogram-shaped polygonal surface, but the polygonal surface may be rectangular. In that case, both ends of one diagonal may be regarded as obtuse corners, and both ends of the other diagonal may be regarded as acute corners.

The pair of long side surfaces 3 have a planar shape parallel to each other, and also extend in parallel with the thickness direction of the insert body 1 (the vertical direction in FIGS. 3 to 6, that is, the central axis C direction described later).
On the other hand, the short side surface 4 is partitioned into four square regions 4A, 4B, 4A, 4B by a horizontal line 4C and a vertical line 4D passing through the center of the short side surface 4, as shown in FIG. 4B is a positive surface. The negative surfaces 4 </ b> A and the positive surfaces 4 </ b> B are arranged at point-symmetric positions with the center in between. Further, the negative surface 4A and the positive surface 4B are adjacent to each other across the horizontal line 4C or the vertical line 4D. That is, the negative surface 4 </ b> A and the positive surface 4 </ b> B are alternately arranged in the thickness direction on the short side 4 on the side continuous with one long side 3 and the side continuous with the other long side 3. The negative surface 4A is disposed on the obtuse corner portion D side of the parallelogram surface 2, that is, on the upper left side and the lower right side in FIG. 4, and has a planar shape extending in parallel with the thickness direction as with the long side surface 3. ing.

On the other hand, the positive surface 4B is disposed on the side that is connected to the long side surface 3 at the acute corner portion of the parallelogram surface 2, that is, the upper right side and the lower left side in FIG. The positive surface 4B is an inclined surface that gradually protrudes in the longitudinal direction (vertical direction in FIG. 2) of the insert body 1 as it is separated from the negative surface 4A adjacent in the thickness direction. At the same time, the positive surface 4B is inclined so as to gradually protrude as it moves away from the negative surface 4A adjacent in the width direction of the insert body 1 (the left-right direction in FIGS. 2 and 4). Thus, the positive surface 4B intersects the long side surface 3 at the acute corner portion of the parallelogram surface 2. The intersecting ridge line portions of the long side surface 3 and the short side surface 4 adjacent to each other in the circumferential direction of the insert body 1 are chamfered in a circular arc shape in cross section.

The insert body 1 is provided with a mounting hole 5 having a circular cross section around a center line C that connects the centers of the pair of parallelogram surfaces 2 in the thickness direction, and the mounting hole 5 is inserted in the thickness direction. It penetrates the main body 1. As shown in FIG. 6, an annular reduced diameter portion 5 </ b> A is formed at the center of the mounting hole 5. The cross section of the reduced diameter portion 5A has a flat central portion over a certain width, and both sides of the flat portion have a convex curve shape.

The insert body 1 is 180 degrees with respect to a symmetric line extending perpendicularly to the center line C in the center of the insert thickness direction and extending parallel to the long side surface 3 and a symmetric line orthogonal to the center line C. ° It is formed in a rotationally symmetric shape. That is, the insert body 1 has a front / back inversion symmetrical shape. The insert body 1 is also formed in a 180 ° rotationally symmetric shape with respect to the center line C.

A main cutting edge 6A is formed on the intersection ridge line portion between the pair of parallelogram surfaces 2 and the pair of long side surfaces 3, that is, the long side ridge portions of the parallelogram surface 2, respectively. Of the pair of parallelogram surfaces 2 and the pair of short side surfaces 4, sub-cutting edges 6 </ b> B are formed on the intersecting ridge line portion of the positive surface 4 </ b> B, that is, the short side ridge portion of the parallelogram surface 2. The acute corner portion of the parallelogram surface 2 where the main cutting edge 6A and the sub cutting edge 6B intersect is chamfered in the above-mentioned circular arc shape at the intersecting ridge line portion between the long side surface 3 and the positive surface 4B. A substantially arcuate corner blade 6C is formed in the portion.

As shown in FIG. 3, the corner blade 6 </ b> C and the main cutting blade 6 </ b> A connected to the corner blade 6 </ b> A are substantially extended over the main cutting blade 6 </ b> A from the contact point with the auxiliary cutting blade 6 </ b> B of the corner blade 6 </ b> C in a side view facing the long side surface 3. It is inclined linearly so as to gradually recede in the thickness direction at a constant inclination angle. On the other hand, the corner cutting edge 6C and the auxiliary cutting edge 6B connected to the corner cutting edge 6B have a convex curve shape with the contact point between the auxiliary cutting edge 6B and the corner cutting edge 6C as the apex as shown in FIG. Has been. Further, the intersection ridge line portion between the negative surface 4A and the parallelogram surface 2 connected to the auxiliary cutting edge 6B gradually recedes in the thickness direction toward the obtuse corner portion D, and then before the obtuse corner portion D. It extends substantially perpendicular to the thickness direction.

The pair of parallelogram surfaces 2 are formed with a positive rake face 2A that gradually recedes in the thickness direction toward the inside, inside the main cutting edge 6A, the auxiliary cutting edge 6B, and the corner cutting edge 6C. Yes. Further, around the mounting hole 5, a boss portion 2B having a substantially conical surface shape centered on the center line C is formed.

Between the positive rake face 2A and the boss part 2B, a pair of ridges 7 having a ridge part 7A is formed, and the ridge part 7A is an obtuse angle where the corner blade 6C of the parallelogram face 2 is not formed. It extends in the direction of a diagonal line connecting the corner portions D. In the present embodiment, the slope of the peak portion 7 is used as a contact surface 8, and the contact surface 8 contacts a contacted surface formed on the bottom surface of an insert mounting seat of a blade-tip-exchangeable cutting tool described later. It is possible.

The ridge portion 7A of the mountain portion 7 has a convex curved section, and gradually increases in height in the thickness direction at a constant inclination angle from the obtuse corner portion D side toward the boss portion 2B. However, the ridge portion 7A does not extend exactly along the diagonal line connecting the obtuse corner portions D, and extends closer to the long side surface 3 that intersects the obtuse corner portion D than the diagonal line.

The slopes on both sides of the ridge 7 are a first slope having a small area inclined so as to recede in the thickness direction of the insert (that is, to descend) toward the long side surface 3 side, and to the short side surface 4 side. In this embodiment, the second inclined surface having a larger area is used as the contact surface 8. .

The abutting surface 8 is a direction from the intersection of the boss portion 2B and the ridge portion 7A toward the substantially central portion in the width direction of the short side surface 4 that intersects the obtuse corner portion D in a plan view as shown in FIG. The inclined plane has a maximum inclination along a direction parallel to the ZZ line in FIG. The skirt of the contact surface 8 has a shape in which the distance from the short side surface 4 gradually increases from the obtuse corner portion D side toward the acute corner portion side where the corner blade 6C is formed in plan view. It extends to the vicinity of the main cutting edge 6A connected to 6C.

FIG. 6 shows a region between the contact surface 8 and the main cutting edge 6A, a region between the contact surface 8 and the auxiliary cutting blade 6B, and a region between the contact surface 8 and the positive rake face 2A. As shown, after retreating in the thickness direction as it goes inward at a steeper slope than the positive rake face 2A, it smoothly connects to the contact surface 8 via a concave curved surface.

Thus, a pair of crests 7 having the contact surface 8 as an inclined surface are formed symmetrically with respect to the center line C on one parallelogram surface 2. Thereby, the virtual extension surface which each extended the contact surface 8 of these peak parts 7 mutually cross | intersects by the intersection ridgeline L orthogonal to the centerline C, and makes the cross-sectional V shape which becomes convex in an insert thickness direction. That is, the pair of contact surfaces 8 are respectively formed along two virtual extension surfaces having a V-shaped cross section. In addition, only one pair of contact surfaces 8 is formed on one parallelogram surface 2, and the V-shaped included angle formed by the virtual extension surface of the pair of contact surfaces 8 is an obtuse angle.

The crossed ridge line L of the pair of contact surfaces 8 is slightly more than the center in the longitudinal direction of the long side surface 3 from the center line C, as shown by a one-dot chain line in FIG. It extends so as to cross obliquely on the side close to the obtuse corner portion D. Since the insert body 1 has a front / back inversion symmetry, the cross ridge line L of the pair of contact surfaces 8 formed on the other parallelogram surface 2 on the opposite side of the parallelogram surface 2 is also the same as above. When viewed from the direction facing the parallelogram surface 2, as shown by a broken line in FIG. 2, the obtuse corner portion D (the back side in FIG. 2) is slightly closer to the center portion in the longitudinal direction of the long side surface 3 from the center line C. It extends so as to cross at an angle.

FIG. 7 and FIG. 8 show the blade-tip-exchangeable cutting tool of the first embodiment provided with the above-mentioned cutting insert in a detachable manner. This cutting edge exchange type cutting tool is a cutting edge exchange type cutting tool, particularly an end mill, and has a tool body 11. The tool body 11 is formed of a steel material or the like and has a multi-stage columnar shape centered on the axis O. Among these, the rear end side portion (upper right portion in FIG. 7) is a shank portion 11A, and the tip portion is a cutting edge portion 11B. It is said that.

In such a blade-tip-exchange-type cutting tool, the shank portion 11A is gripped by the main spindle of the machine tool, and the tool main body 11 is sent in the direction intersecting the axis O while being rotated in the tool rotation direction T around the axis O. Thus, the workpiece is cut by the cutting blades (the main cutting blade 6A, the sub cutting blade 6B, and the corner blade 6C) of the cutting insert attached to the cutting blade portion 11B.

On the outer periphery of the cutting edge portion 11B, a plurality of (three in the present embodiment) chip pockets 12 are formed at regular intervals in the circumferential direction and open to the front end surface thereof, that is, the front end surface of the tool body 11 and extend to the rear end side. ing. Further, as shown in FIG. 8, on the wall surface facing the tool rotation direction T side of these chip pockets 12, an insert mounting seat 13 to which the cutting insert is attached is opened at the tip surface and the outer peripheral surface of the cutting edge portion 11B. Is formed so as to be recessed one step from the wall surface to the rear side in the tool rotation direction T.

The insert mounting seat 13 has a bottom surface 14 facing the tool rotation direction T, a wall surface 15 facing the tool outer peripheral side, and 16 facing the tool tip side. Of the pair of parallelogram surfaces 2 of the insert body 1, when one parallelogram surface 2 is oriented as a rake face in the tool rotation direction T, the other parallelogram surface 2 serves as a seating surface on the bottom surface 14. Be seated. The wall surface 15 rises from the edge of the bottom surface 14 on the inner peripheral side of the tool body 11 toward the tool rotation direction T and continues to the wall surface facing the tool rotation direction T of the chip pocket 12. The wall surface 16 rises from the edge of the bottom surface 14 on the tool rear end side toward the tool rotation direction T and continues to the wall surface facing the tool rotation direction T of the chip pocket 12. Of these, a notch 15A is formed in the central portion of the wall surface 15 in the axis O direction.

However, the intersecting ridge line portion between the bottom surface 14 and the wall surfaces 15 and 16 and the intersecting ridge line portion between the wall surfaces 15 and 16 are mainly arranged on the inner peripheral side of the tool main body 11 of the parallelogram surface 2 as the seating surface. In order to avoid interference with the cutting blade 6A, the auxiliary cutting blade 6B disposed on the rear end side of the tool body 11, and the corner blade 6C disposed on the inner peripheral side of the rear end, a relief having a concave groove shape having a substantially semicircular cross section. Notched by the portion 17A.

The intersecting ridge line portion between the bottom surface 14 and the distal end surface and the outer peripheral surface of the cutting blade portion 13 is also disposed on the distal end side of the main cutting edge 6A disposed on the tool outer peripheral side of the parallelogram surface 2 which is also a seating surface. In order to avoid interference with the auxiliary cutting edge 6B, the corner edge 6C arranged on the outer peripheral side of the tip, the positive rake face 2A on the inside, etc., a chamfered relief portion 17B is formed.

In the center of the bottom surface 14, a clamp inserted into the mounting hole 5 from one parallelogram surface 2 side, which is a rake face, with the insert body 1 seated on the insert mounting seat 13 as described above. A screw hole 14A into which the screw 18 is screwed is formed. The insert body 1 is attached to the insert attachment seat 13 when the back surface of the head of the clamp screw 18 screwed into the screw hole 14A presses the reduced diameter portion 5A of the attachment hole 5. A concave relief portion 17 </ b> C for avoiding interference with the boss portion 2 </ b> B on the parallelogram surface 2 side, which is a seating surface, is also formed around the screw hole 14 </ b> A of the bottom surface 14.

The bottom surface 14 is formed with a pair of abutting surfaces 19 on which the pair of abutting surfaces 8 of the parallelogram surface 2 as a seating surface can abut. The two virtual extension surfaces extending the contacted surface 19 intersect at an intersecting ridgeline, and the cross-section is complementary to the cross section of the two virtual extension surfaces extending the paired contact surfaces 8 with the concavities and convexities reversed. It is in shape. Therefore, in this embodiment, the cross section of the virtual extension surface which extended a pair of to-be-contacted surface 19 has comprised V shape. The pair of abutted surfaces 19 form a pair of inclined planes that approach each other as the virtual extension surface thereof approaches the bottom side of the bottom surface 14 (the rear side in the tool rotation direction T). When viewed along the intersecting ridgeline, the pair of contacted surfaces 19 extend along a pair of virtual extension surfaces that intersect the V shape formed by the contact surface 8 and the opposite V shape having a substantially equal included angle. ing. Accordingly, only one pair of the contacted surfaces 19 of the bottom surface 14 of the insert mounting seat 13 is provided.

The intersecting ridge line where the virtual extension surfaces of the pair of contacted surfaces 19 intersect each other is orthogonal to the center line of the screw hole 14A and when viewed from the tool rotation direction T side facing the bottom surface 14 in the center line direction. Furthermore, it extends toward the rear end side from the center line toward the inner peripheral side of the tool main body 11, and obliquely intersects the wall surface 15 facing the outer peripheral side of the tool main body 11 of the insert mounting seat 13. When the insert body 1 is viewed from one parallelogram surface 2 side, the intersection angle formed by the intersecting ridge line and the wall surface 15 is a pair of the other parallelogram surfaces 2 on the opposite side opposite to the front and back shown in FIG. The intersecting ridge line L of the contact surface 8 is made equal to the intersecting angle formed with respect to the long side surface 3. The wall surface 15 has a planar shape parallel to the screw hole 14A except for the notch 15A.

In the insert mounting seat 13 formed in this way, the cutting insert is oriented in the tool rotation direction T with one parallelogram surface 2 of the insert body 1 as a rake face, and one long side surface 3 as described above. Is directed to the outer peripheral side of the tool body 11, one short side surface 4 is directed to the tip side of the tool body 11, and the other parallelogram surface 2 is seated on the bottom surface 14. Accordingly, the pair of contact surfaces 8 of the other parallelogram surface 2 are brought into contact with the pair of contact surfaces 19 of the bottom surface 14. In this state, the insert body 1 has a direction along the intersecting ridge line L of the pair of contact surfaces 8 in the other parallelogram surface 2 in a state where the center line C is parallel to the center line of the screw hole 14A. Only movement to is allowed and restrained in other directions.

In this way, with the insert body 1 seated, along the intersecting ridge line L in the other parallelogram surface 2 toward the long side surface 3 opposite to the one long side surface 3, that is, the tool body 11. When the insert body 1 is moved toward the inner peripheral side of the rear end, the long side surface 3 comes into contact with the wall surface 15 and the insert body 1 is positioned. (1) The center line of the screw hole 14A between the intersection angle of the long side surface 3 and the intersecting ridge line L as viewed in the direction of the center line C, and the intersecting ridge lines of the wall surface 15 of the insert mounting seat 13 and the pair of contacted surfaces 19 The crossing angles in the direction view are made equal to each other. (2) The long side surface 3 has a planar shape parallel to the center line of the center line C, and the wall surface 15 has a planar shape parallel to the center line of the screw hole 14A. Due to the reasons (1) and (2) above, the long side surface 3 can come into contact with the entire surface of the wall surface 15, and the insert body 1 can be positioned stably.

That is, in the present embodiment, the long side surface 3 is used as a contact portion and the wall surface 15 is used as a contact portion, and the cross ridge line L on the parallelogram surface 2 side serving as a seating surface extends in the extending direction. An abutting portion is formed on the long side surface 3 facing in one direction, and the abutting portion can abut on an abutted portion formed on the wall surface 15 rising from the bottom surface 14 of the insert mounting seat 13.

Furthermore, in this state of positioning, the center line C of the mounting hole 5 of the insert body 1 is slightly decentered toward the outer periphery of the tool tip with respect to the center line of the screw hole 14A. Therefore, when the clamp screw 18 is screwed into the screw hole 14 </ b> A as described above, a portion of the reduced diameter portion 5 </ b> A of the attachment hole 5 that is located on the inner peripheral side of the rear end of the tool hole 11 by the back surface of the head of the clamp screw 18. Pressed. Accordingly, the insert body 1 is detachably fixed to the insert mounting seat 13 so as to be pressed against the bottom surface 14 by the clamp screw 18 and also against the wall surface 15.

In the cutting insert of the first embodiment and the cutting edge-exchangeable cutting tool of the first embodiment, the pair of abutting surfaces 19 in which the insert body 1 is formed on the bottom surface 14 of the insert mounting seat 13 as described above. And the wall surface 16 of the insert mounting seat 13 facing the distal end side of the tool body 11 is used for attaching the cutting insert. Not involved. That is, with respect to one direction among the directions in which the intersecting ridge lines L extend with respect to one parallelogram surface 2, only one long side surface 3 serves as a contact portion in the present embodiment, and It is made to contact | abut to the to-be-contacted part of a wall surface.

For this reason, as shown in FIG. 8, by forming a large chip pocket 12 on the rear end side of the tool body 11 of the insert mounting seat 13, the wall surface 16 becomes smaller or the other one directed toward the rear end side of the tool. Even if there is a gap between the short side surface 4 and the wall surface 16 or the wall surface 16 itself is not formed in some cases, there is no problem in mounting the cutting insert. Therefore, even if the large chip pocket 12 is formed, the cutting insert can be stably held, and the chip discharge performance can be improved by the large chip pocket 12.

7 and 8, only one insert mounting seat 13 is formed in the cutting edge portion 11B at the tip of the tool body 11 in the direction of the axis O. In the cutting edge replacement type cutting tool of the first embodiment shown in FIGS. However, the present invention is not limited to this, and one or a plurality of insert mounting seats 13 can be formed on the rear end side of the insert mounting seat 13 to increase the number of blades of the tool. Even in such a case, according to the cutting insert and the cutting edge replacement type cutting tool, it is not necessary to form the wall surface 16 on the rear end side of the insert mounting seat 13 as described above. The mounting seat 13 can be formed in close proximity.

For example, the insert mounting seat 13 adjacent to the rear end side in the direction of the axis O is shifted to the rear side in the tool rotation direction T by the thickness of the insert body 1 to be mounted on the row of insert mounting seats 13. It is also possible to form a cutting blade row in which the rotation trajectory of the main cutting blade 6A is continuous by the cutting insert. For this reason, it is possible to provide a large number of such cutting blade rows in one tool body 11, and it is possible to improve the cutting efficiency.

In the cutting insert of the present embodiment, the insert body 1 has a reverse-inverted symmetrical shape, and when the main cutting edge 6A, the auxiliary cutting edge 6B, and the corner edge 6C are worn, the insert body 1 is reversed. Then, by reattaching to the insert mounting seat 13, the one parallelogram surface 2 that was the rake face is used as a seating surface, and the other parallelogram surface 2 that is the seating surface is used as the rake face. The main cutting edge 6A, the auxiliary cutting edge 6B, and the corner edge 6C formed on the side ridge portion of the other parallelogram surface 2 can be used.

At this time, the new long side surface 3 positioned on the inner peripheral side of the tool body 11 serves as a contact portion with respect to the parallelogram surface 2 which is a new seating surface. It is made to contact | abut to the wall surface 15 which is a part. That is, by reversing the insert body 1 in this way, it is possible to abut on the wall surface 15 that is the abutted portion of the insert mounting seat 13 with the opposite long side surface 3 as the abutting portion.

In the present embodiment, the insert body 1 is formed to be 180 ° rotationally symmetric with respect to the center line C, and by rotating 180 ° around the center line C, one parallelogram surface 2 remains as a rake face, Each pair of main cutting edge 6A, sub cutting edge 6B, and corner cutting edge 6C formed in the crossed ridge line portion and the acute corner portion of the pair of long and short side surfaces 3 and 4 can be used. That is, in the cutting insert of this embodiment, the main cutting edge 6A, the auxiliary cutting edge 6B, and the corner cutting edge 6C can be used four times in total.

At this time, with respect to one other parallelogram surface 2 which is a seating surface, the long side surface 3 opposite to the tip in the direction in which the intersecting ridge line L extends serves as a contact portion of the insert mounting seat 13. It can be brought into contact with the wall surface 15 which is a contacted portion.

Thus, when the insert body 1 is rotated by 180 ° around the center line C and attached to the insert mounting seat 13 and when the insert body 1 is attached with the front and back reversed, the same long side surface 3 becomes the contact portion. That is, of the pair of front and back parallelogram surfaces 2, one long side surface 3 that faces one direction of the intersecting ridge line L direction in one parallelogram surface 2 and one other parallelogram surface 2. One long side surface 3 that faces the other direction among all the intersecting ridge lines L is the one long side surface 3. Then, a contact portion is formed on the long side surface 3.

9 to 14 show a second embodiment of the cutting insert of the present invention. FIG. 15 shows a second embodiment of the cutting edge-exchangeable cutting tool to which the cutting insert of the second embodiment is attached. FIG. 16 shows a state in which the cutting insert has been removed from the cutting edge-exchangeable cutting tool of the second embodiment.
The cutting insert and the cutting edge-exchangeable cutting tool of the second embodiment have an insert body 21, and the pair of abutting surfaces of the insert body 21 and the pair of abutting surfaces of the bottom surface of the insert mounting seat are the first. It is different from the embodiment. Since these points are substantially the same as those in the first embodiment, common elements are assigned the same reference numerals and description thereof is omitted.

In the cutting insert according to the second embodiment, a pair of contact surfaces 22 are formed on the pair of parallelogram surfaces 2 of the insert body 21, and the virtual extension surfaces of these contact surfaces 22 intersect with each other so as to form a V shape. It has been. That is, the contact surface 22 is formed to extend in the V-shaped direction having a concave cross section. Furthermore, the intersection ridge line L of the virtual extension surface of the contact surface 22 is arranged so as to obliquely intersect the short side surface 4 of the insert body 21 as shown in FIG. 10 when viewed from the center line C direction. Yes.

On the inner side of the pair of parallelogram surfaces 2, along the diagonal line connecting the obtuse corner portions of the parallelogram surface 2, a valley portion 23 having a V-shaped cross section is formed except for the boss portion 2 </ b> B around the mounting hole 5. Is formed. These troughs 23 once protrude in the insert thickness direction with respect to the positive rake face 2A located inside the main cutting edge 6A, the sub cutting edge 6B, and the corner cutting edge 6C, and then from the corner cutting edge 6C sides on both sides. As it goes substantially to the diagonal line side, it has a V shape with a recessed section so that it gradually recedes (lowers) in the thickness direction. A pair of slopes constituting the valley portion 23 is a pair of contact surfaces 22 in the present embodiment. The angle between the pair of contact surfaces 22 having a V-shaped cross section is an obtuse angle, as in the first embodiment.

However, when viewed from the direction of the center line C, the bottom line of the valley 23, that is, the intersecting ridge line L of the virtual extension surface of the pair of contact surfaces 22 is a diagonal line connecting obtuse corners, as shown by a one-dot chain line in FIG. And the intersecting ridge line L intersects the negative surface 4A of the short side surface 4 intersecting the parallelogram surface 2 obliquely. That is, the inclination angle formed by the intersecting ridge line L and the insert longitudinal direction is smaller than the inclination angle formed by the diagonal line connecting the obtuse corner and the insert longitudinal direction. Therefore, in the other parallelogram surface 2 of the insert body 21 that is reversely symmetric with respect to the front and back, the cross ridge line L of the virtual extension surface of the pair of abutting surfaces is shown in FIG. It intersects diagonally with the positive surface 4B of the short side surface 4 that intersects the parallelogram surface 2.

FIG. 15 and FIG. 16 show the cutting edge exchangeable cutting tool of the second embodiment to which the cutting insert of the second embodiment is attached. An insert mounting seat 13 is formed at the tip of the cutting edge portion 11B of the tool body 11, and a bottom surface 14 of the insert mounting seat 13 includes a pair of abutted surfaces 24. The virtual extension surfaces that extend the contacted surfaces 24 that form a pair intersect with the virtual extension surfaces that extend the contact surface 22 that forms a pair in an inverted V-shaped cross-section with reverse concavities and convexities. The included angle between the virtual extended surfaces extending the paired contact surfaces 24 is substantially equal to the included angle between the virtual extended surfaces extending the paired contact surfaces 22. As a result, the pair of abutted surfaces 24 are complementary to the pair of abutting surfaces 22.

The intersecting ridge line where the virtual extension surfaces of the pair of contacted surfaces 24 intersect each other is orthogonal to the center line of the screw hole 14A. In addition, when viewed along the screw center line, this intersecting ridge line reaches the intersection line between the virtual extension surfaces of the wall surface 15 facing the tool outer peripheral side of the insert mounting seat 13 and the wall surface 16 facing the tip side. However, it is arranged so as to obliquely intersect the extended surface of the wall surface 16. The intersection angle between the intersection ridge line and the extension surface of the wall surface 16 is the intersection ridge line L between the extension surface of the negative surface 4B of the short side surface 4 and the contact surface 22 when the insert body 21 is viewed along the central axis C. Is substantially equal to the crossing angle formed by.

In the second embodiment, the insert main body 21 is formed on the insert mounting seat 13 with one parallelogram surface 2 as a rake face and the other parallelogram surface 2 as a seating surface as in the first embodiment. When seated, the pair of contact surfaces 22 of the other parallelogram surface 2 contacts the pair of contact surfaces 24 of the bottom surface 14. In this state, the insert body 21 is only allowed to move in the direction of the intersecting ridge line L on the other parallelogram surface 2 and is restrained in the other direction. Further, when the insert main body 21 is moved toward the short side surface 4 directed toward the rear end side of the tool, the short side surface 4 is brought into contact with the wall surface 16 of the insert mounting seat 13 and positioned.

That is, in this embodiment, the wall surface 16 is a contacted portion, and the other short side facing the one side in the intersecting ridge line L direction with respect to the parallelogram surface 2 as the seating surface of the insert body 21. A contact portion that can contact the contacted portion (wall surface 16) is formed only on the side surface 4. More specifically, the wall surface 16 has a planar shape parallel to the screw hole 14 </ b> A, and is parallel to the center line C that intersects one parallelogram surface 2 of the other short side surface 4 of the insert body 21. The negative surface 4 </ b> A is a contact portion that can partially contact the wall surface 16.

Therefore, in the second embodiment, the wall surface 15 facing the outer peripheral side of the tool body 11 of the insert mounting seat 13 is not involved in the mounting of the cutting insert, contrary to the first embodiment. Therefore, by increasing the chip pocket 12 on the inner peripheral side of the insert mounting seat 13, even when the wall surface 15 is reduced or the wall surface 15 is eliminated in some cases, the mounting stability of the insert body 21 is impaired. There is nothing. For this reason, improvement of chip discharge | emission property can be promoted, hold | maintaining a cutting insert reliably.

In addition, when the cutting edge replaceable cutting tool has a very small diameter, for example, if the outer diameter of the tip of the tool body is about twice the size in the width direction of the insert body, usually one insert is attached. Only the seat can be formed. However, in the cutting insert and the cutting edge replacement type cutting tool of the second embodiment, since the wall surface 15 facing the outer peripheral side of the tool body 11 may not be provided as described above, two or more are provided at the tip of the tool body 11. The plurality of insert mounting seats 13 can be formed so that their inner peripheral sides communicate with each other, and a cutting insert can be attached to each. Therefore, even in such an extremely small diameter cutting edge exchangeable cutting tool, it is possible to increase the number of blades and improve the cutting efficiency.

Next, FIGS. 17 to 22 show a third embodiment of the cutting insert of the present invention. FIG. 23 shows a third embodiment of the cutting edge replaceable cutting tool of the present invention to which the cutting insert of the third embodiment is attached, and FIG. 24 shows the cutting insert in the cutting edge replaceable cutting tool of the third embodiment. Shows the state where is removed. The cutting insert and cutting edge-exchangeable cutting tool of the third embodiment are different in the short side surface 32 of the insert body 31, the contact portion formed on the short side surface 32, and the contacted portion of the insert mounting seat 13. Except for this, it is substantially the same as in the second embodiment, so common elements are assigned the same reference numerals and description thereof is omitted.

In the cutting insert of the third embodiment, a groove 33 having a concave cross section such as a concave arc as shown in FIG. 18 is formed in the center in the width direction of the pair of short side surfaces 32 of the insert main body 31. These concave grooves 33 are formed along the thickness direction across the pair of parallelogram surfaces 2 and serve as contact portions. On the other hand, in the cutting edge exchangeable cutting tool of the third embodiment, the wall surface 16 facing the tool tip side is a contacted portion of the insert mounting seat 13, and a cross section perpendicular to the center line of the screw hole 14A of the wall surface 16 Has a convex curve shape such as a convex arc with which the bottom surface of the concave groove 33 can abut.

The radius of curvature of the convex curve formed by the cross section of the wall surface 16 is smaller than the radius of curvature of the concave curve formed by the cross section of the concave groove 33. Moreover, the part of the width direction both sides of the said groove 33 among the short side surfaces 32 of the insert main body 31 is an intersection ridgeline part with the parallelogram surface 2 of the side in which the subcutting-blade 6B is formed in the said thickness direction, respectively. The positive surface 4B protrudes entirely in the longitudinal direction of the insert as it goes to.

In the cutting insert of the third embodiment, as in the second embodiment, the pair of abutting surfaces 22 of the parallelogram surface 2 serving as the seating surface is replaced with the pair of abutting surfaces of the bottom surface 14 of the insert mounting seat 13. The insert body 31 is seated against the surface 23. Further, when the insert main body 31 is moved to the short side surface 32 side facing the tool rear end side, the concave groove 33 formed in the short side surface 32 accommodates the wall surface 16 having a convex curved section and is recessed into the wall surface 16. The bottom surface of the groove 33 is brought into contact. Therefore, also in the third embodiment, the chip pocket 12 on the inner peripheral side of the insert mounting seat 13 is enlarged as in the second embodiment to improve the chip discharging property, and in the circumferential direction of the tool body 11. Many insert mounting seats 13 can be formed to increase the number of blades, and the cutting efficiency can be improved.

In the first and second embodiments, the contact portions of the insert bodies 1 and 21, that is, the negative surface 4 A of the long side surface 3 and the short side surface 4, and the contacted portions of the insert mounting seat 13, that is, the wall surface 15 and the wall surface 16. Are brought into contact with each other so as to be in surface contact with each other. Therefore, if the insert main bodies 1 and 21 and the insert mounting seat 13 are molded with high accuracy, the contact portion can be brought into surface contact with the contacted portion, but if the molding accuracy is not high, the contact portion The part may contact the contacted part by line contact or point contact.

On the other hand, in the third embodiment, the concave groove 33 having a concave curved section that is a contact portion is brought into contact with the wall 16 having a convex curved section that is a contacted portion. Alternatively, even when the molding accuracy of both is not high, at any position of the concave-convex curve, line contact on a straight line along the thickness direction, or a range having a certain width around this straight line With the surface contact, the contact portion is brought into contact with the contacted portion. For this reason, according to the third embodiment, the insert main body 31 can be more reliably supported on the insert mounting seat 13 and the mounting stability of the cutting insert can be further improved.

In the third embodiment, when the abutting portion is formed on the short side surface 32, a concave groove 33 having a concave cross-sectional shape is formed on the short side surface 32, and the wall surface 16 to be the abutted portion is formed as a convex convex section In the case where the abutment portion is formed on the long side surface 3 as in the first embodiment, a concave groove is formed on the long side surface 3 and the projection shape on which the concave groove can abut. The abutted portion may be formed on the wall surface 15. However, in this case, the main cutting edge 6A of the insert main body 1 is divided by the concave groove. Therefore, when the contact portion is formed on the short side surface 32 as in the third embodiment, it is desirable that the concave groove 33 is formed on the short side surface 32.

In the first embodiment, the pair of contact surfaces 8 are respectively formed along a pair of virtual extension surfaces intersecting the inverted V-shaped section, and the pair of contacted surfaces 19 are a pair intersecting the V-shaped section. Each of them is formed along the virtual extension surface. In the second and third embodiments, on the contrary, the pair of contact surfaces 22 are formed along a pair of virtual extension surfaces intersecting the V-shaped cross section, and the pair of contacted surfaces 24 have an inverted V-shaped cross section. They were formed along a pair of intersecting virtual extended surfaces, and the included angles of these V-shaped and inverted V-shaped were substantially equal to each other. However, considering the forming accuracy as described above, the V-shaped sandwich angle may be slightly smaller than the inverted V-shaped sandwich angle in any of the first to third embodiments. In this case, since the V-shaped cross section and the reverse V-shaped cross section are in contact at both ends rather than in line contact at the intersecting ridgeline L, the cutting insert can be stably inserted even if the molding accuracy is not high. Can be seated and attached.

In the first embodiment, the short side surface 4 is not involved in the mounting of the cutting insert. In the second and third embodiments, the negative surface of the short side surface 4 is in contact with the wall surface 16 that is the contacted portion. Since it is the surface 4A or the concave groove 33, in these first to third embodiments, the positive surface 4B of the short side surfaces 4 and 32 does not participate in the insert mounting. Therefore, in the first to third embodiments, the minor cutting edge 6B and the corner cutting edge 6C formed at the intersecting ridge line portion between the positive surface 4B of the short side surfaces 4 and 32 and the pair of parallelogram surfaces 2. Even if the shapes are different from each other, they can be mounted on the same insert mounting seat 13 as they are.

Therefore, particularly in the first embodiment, when the plurality of insert mounting seats 13 are formed in the direction of the axis O as described above, the cutting insert attached to the most advanced insert mounting seat 13 is, for example, the above-described positive surface 4B. It can also be mounted as a cutting insert in which a corner blade 6C having a large radius is formed by increasing the protruding amount in the longitudinal direction. That is, since a plurality of types of cutting inserts having corner radii 6C having different radii can be attached to one tool body 11, one tool body can be formed even when corners having different radii are formed during shoulder cutting. 11 can cope with this.

As described above, according to the cutting insert and the cutting edge-exchangeable cutting tool of the present invention, a large chip pocket can be secured on the tool body rear end side or inner peripheral side of the insert mounting seat, and the chip dischargeability can be improved. In addition to being able to improve, it is possible to increase the number of cutting inserts that can be attached in the direction of the rotation axis or the circumferential direction of the tool body, thereby promoting efficient cutting. Therefore, industrial use is possible.

1, 21, 31 Insert body 2 Parallelogram surface (polygonal surface)
3 Long side surface (contact portion in the first embodiment)
4, 32 Short side surface 4A Short side negative surface (contact portion in the second embodiment)
4B Positive surface of short side 5 Mounting hole 6A Main cutting edge 6B Sub cutting edge 6C Corner blade 7 Crest portion 8, 22 Contact surface 11 Tool body 12 Tip pocket 13 Insert mounting seat 14 Bottom surface of insert mounting seat 13 14A Screw hole 15 Wall surface facing the outer peripheral side of the tool body 11 of the insert mounting seat 13 (abutted portion in the first embodiment)
16 Wall surface facing the distal end side of the tool body 11 of the insert mounting seat 13 (contacted portion in the second and third embodiments)
18 Clamp screw 19, 24 Contact surface 23 Valley portion 33 Concave groove (contact portion in the third embodiment)
C Center line of the insert bodies 1 and 31 L Crossing ridge line where two virtual extension surfaces extending the pair of contact surfaces 8 and 22 intersect O The axis line of the tool body 11 T Tool rotation direction

Claims (18)

1. A cutting insert that is detachably attached to an insert mounting seat of a cutting edge exchangeable cutting tool,
   A polygonal plate-like insert body having a pair of polygonal surfaces and a plurality of side surfaces arranged around the polygonal surfaces,
   A cutting edge is formed on the side ridge of the polygonal surface,
   The insert body is a reverse-inverted symmetrical shape with respect to the pair of polygonal surfaces,
   The pair of polygonal surfaces is a seating surface on which the other polygonal surface is seated on the bottom surface of the insert mounting seat when one of the polygonal surfaces is a rake face,
   A contact surface that is a pair of flat surfaces is formed on each of the pair of polygonal surfaces,
   The pair of abutment surfaces can abut against a pair of abutment surfaces formed on the bottom surface of the insert mounting seat when the one polygonal surface is the seating surface,
   The two virtual extension surfaces obtained by extending the pair of contact surfaces intersect each other at a crossing ridgeline in a cross-section V shape or a cross-section inverted V shape,
   Of the side surfaces of the insert body, the side surface of the pair of contact surfaces facing one direction out of the two directions in which the intersecting ridgeline of the virtual extension surface extends rises with respect to the bottom surface of the insert mounting seat 1 A cutting insert characterized in that an abutting portion capable of abutting against an abutted portion formed on two wall surfaces is formed.
2. The insert body has a shape that is 180 ° rotationally symmetric with respect to the center line of the pair of polygonal surfaces,
   The insert main body is placed on the center line on the other one side surface with respect to one polygonal surface facing the other direction of the direction in which the intersecting ridgeline of the virtual extension surface of the pair of contact surfaces extends. 2. The cutting insert according to claim 1, wherein another abutting portion capable of abutting on the abutted portion when rotated 180 ° around is formed.
3. Each of the polygonal surfaces of the insert body has a rectangular shape,
   The insert body has a pair of long side surfaces arranged on opposite sides and a pair of short side surfaces arranged on opposite sides,
   A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface,
   The main cutting edge is inclined so as to gradually retreat in the thickness direction from one corner portion to the other corner portion when viewed from the side facing the long side surface. The cutting insert according to claim 2.
4. The cutting insert according to claim 3, wherein the pair of contact surfaces are formed inside the polygonal surface.
5. The intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the long side surface when viewed from the direction facing the polygonal surface, and the contact portion is formed on the long side surface. The cutting insert according to claim 3 or 4, characterized by the above.
6. The cutting insert according to claim 5, wherein two virtual extension surfaces obtained by extending the pair of contact surfaces on each polygonal surface intersect in an inverted V shape in cross section at the intersecting ridgeline. .
7. The intersection ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction obliquely intersecting the long side surface when viewed from a direction facing the polygonal surface. Cutting inserts.
8. The said crossing ridgeline is formed toward the direction which cross | intersects the diagonal of said one corner part in the said polygonal surface seeing from the direction facing the said polygonal surface. Cutting insert as described.
9. The polygonal surface of the insert body has a parallelogram shape having a pair of obtuse corners and a pair of acute corners,
   Corner blades are respectively formed at the acute corner portions of the polygonal surfaces,
   A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface,
   The main cutting edge is inclined so as to gradually recede in the thickness direction from the acute corner portion to the obtuse corner portion when viewed from the side facing the long side surface,
   3. The cutting insert according to claim 2, wherein an intersection ridge line of a virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the long side surface when viewed from a direction facing the polygonal surface. .
10. The intersecting ridge line of the virtual extension surface of the pair of contact surfaces is in a direction intersecting the long side surface at a position closer to the obtuse corner portion than the acute corner portion as seen from the direction facing the polygonal surface. The cutting insert according to claim 9, wherein the cutting insert extends.
11. The intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the short side surface when viewed from the direction facing the polygonal surface, and the contact portion is formed on the short side surface. The cutting insert according to claim 3 or 4, characterized by the above.
12. The cutting insert according to claim 11, wherein two virtual extension surfaces obtained by extending the pair of contact surfaces on each polygonal surface intersect in a V-shaped cross section at the intersecting ridgeline.
13. The intersecting ridge line of the virtual extension surface of the pair of contact surfaces extends in a direction obliquely intersecting the short side surface when viewed from a direction facing the polygonal surface. Cutting inserts.
14. The intersection ridge line is formed in a direction intersecting with a diagonal line of the one corner portion on the polygonal surface when viewed from a direction facing the polygonal surface. Cutting insert as described.
15. The polygonal surface of the insert body has a parallelogram shape having a pair of obtuse corners and a pair of acute corners,
    Corner blades are respectively formed at the acute corner portions of the polygonal surfaces,
    A main cutting edge is formed at each intersection ridge line portion between each polygonal surface and each long side surface,
    The main cutting edge is inclined so as to gradually recede in the thickness direction from the acute corner portion to the obtuse corner portion when viewed from the side facing the long side surface,
    The cutting insert according to claim 2, wherein an intersection ridge line of a virtual extension surface of the pair of contact surfaces extends in a direction intersecting with the short side surface when viewed from a direction facing the polygonal surface. .
16. The intersecting ridge line of the virtual extension surface of the pair of contact surfaces is in a direction intersecting the short side surface at a position closer to the obtuse corner portion than the acute corner portion as seen from the direction facing the polygonal surface. The cutting insert according to claim 15, wherein the cutting insert extends.
17. The contact portion is a groove having a concave curved cross section formed on the side surface, and the groove extends between the pair of polygonal surfaces and is formed on one wall surface of the insert mounting seat. The cutting insert according to any one of claims 1 to 16, wherein the cutting insert can be brought into contact with the abutted portion having a convex cross-sectional shape.
18. A cutting edge exchangeable cutting tool,
    A tool body rotated about an axis,
    The cutting insert according to any one of claims 1 to 17, which is detachably attached to the outer periphery of the tool body,
    In the tool body, one or more insert mounting seats are formed with the bottom surface facing the tool rotation direction and the one wall surface facing the outer peripheral side or the axial direction front end side,
    On the bottom surface of the insert mounting seat, a pair of the abutted surfaces that abut against the abutting surface of the cutting insert is formed, respectively.
    The two virtual extension surfaces obtained by extending the pair of contacted surfaces intersect each other at an intersecting ridge line in a cross-section inverted V shape or a cross-section V shape complementary to the contact surface of the cutting insert,
    A cutting edge, wherein the one wall surface of the insert mounting seat is formed with a contacted portion that contacts the contact portion of the cutting insert at a position where the intersecting ridge line of the contacted surface is directed. Replaceable cutting tool.

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