JP5589425B2 - Cutting inserts for grooving and parting off - Google Patents

Description

  The present invention relates to a grooving / parting-off cutting insert used for grooving or parting-off of a work material.

  As a cutting insert used for such grooving or parting-off processing, for example, in Patent Document 1, a concave portion is provided so as to lower the rake face at the approximate center of the cutting edge of the front cutting edge. The thing which provided the ditch | groove continued from this crevice and extended back is proposed. In the cutting insert described in Patent Document 1, chips are generated in a cross-sectional shape following the front cutting edge in which a recess is formed, and the chip is deformed so as to be narrowed down by the recess groove, so that the chip is stable with a small cutting resistance. It is said that the deformed effect can be given.

JP 2001-212704 A

  However, in the cutting insert described in Patent Document 1, the concave portion is opened on the front clearance surface of the front cutting edge, and the shape of the front cutting edge itself becomes a middle concave shape. It is inevitable that an uncut portion will be generated due to the recessed portion at the bottom of the formed groove. Further, in order to generate a cross-sectional chip following the front cutting edge of such a hollow shape and deform it so as to be narrowed down by the concave groove, the chip is generated in the substantial length in the width direction, that is, in the middle concave section. The length in which the chips are expanded becomes longer and the contact length with the front cutting edge and the groove becomes longer, which may cause an increase in cutting resistance.

  The present invention has been made under such a background, and it is possible to reliably treat chips without causing uncut residue on the workpiece or increasing cutting resistance during grooving. It aims to provide a cutting insert for grooving and parting off.

In order to solve the above-described problems and achieve such an object, the present invention provides these rake surfaces on the intersecting ridge line portion between the rake surface of the cutting edge portion provided on the end portion of the insert body and the front flank surface. And a cutting edge having a honing surface connected to the front flank surface is formed, and a concave portion is formed on the intersecting ridge line portion between the honing surface and the rake surface so as not to intersect the front flank surface , The honing surface is formed so as to cut out the intersecting ridge line portion between the honing surface and the rake surface at a constant inclination angle that is gentler than the honing angle with respect to the rake surface , and the honing surface and the front flank surface The honing width from the intersecting ridge line portion to the intersecting ridge line portion of the concave portion and the honing surface is configured to increase from the center portion of the cutting blade toward both end portions of the cutting blade. To do.

  In the grooving / parting-off insert configured as described above, a honing surface is formed on the cutting edge formed at the crossing ridge line portion of the rake surface and the front flank surface, and the honing surface and the front flank surface are The intersecting ridge portion substantially acts as the edge of the front cutting edge. Then, the chips generated by the edge rub against the honing surface and flow out to the rake face side. The honing surface has a large honing width from the center of the cutting edge toward both ends. Since such a recess is formed, the chip is given greater resistance at both ends of the cutting blade than at the center.

  Therefore, the chips to which such resistance is given are rounded in the width direction toward the center of the cutting edge having a low resistance, and are also rounded by receiving resistance in the outflow direction when rubbing the rake face from the recess. As a result, the stress is concentrated and is surely divided. On the other hand, the concave portion is configured not to intersect the front flank, and as described above, the intersecting ridge line portion between the honing surface and the front flank that substantially acts as the edge of the front cutting edge. Since there is no center recess shape, there is no uncut residue on the bottom of the processed groove, and the actual length in the width direction of the generated chips is not increased. The contact length in the width direction with the easy surface is not increased, and the cutting resistance can be reliably reduced.

  Here, among the honing widths from the intersecting ridge line portion between the honing surface and the front flank surface to the intersecting ridge line portion between the concave portion and the honing surface, the honing width B at the center portion of the cutting edge that is the smallest is the concave portion. If the front flank does not intersect, that is, if the intersecting ridge line portion between the front flank and the honing surface, which is a substantial cutting edge, does not have a concave shape, B = 0 may be satisfied. In other words, the concave portion may reach the intersection ridgeline between the front relief surface and the honing surface at the central portion of the cutting edge, but in that case, the honing surface disappears at the central portion of the cutting blade, so There is a risk of blade loss.

  On the other hand, if the honing width B at the center of the cutting edge is too large, the length of the chip flowing out along the honing surface is increased and rounded in the outflow direction before being rounded in the width direction, Since it may be difficult to achieve efficient chip separation due to stress concentration, the honing width B at the center of the cutting edge is greater than 0 and 0 mm <B ≦ in the direction along the rake face. It is desirable to be within a range of 0.1 mm.

  Further, it is desirable that the concave portion is cut off without reaching both ends of the cutting edge, that is, at both ends of the cutting edge, the intersecting ridge line portion between the honing surface and the rake face is left and the honing surface is in front. It is desirable to form from the intersection ridge line portion with the flank face to the intersection ridge line portion with the rake face. As a result, both ends of the cutting edge can be more reliably given resistance to the chip than at the center, and therefore it is possible to more reliably promote rounding of the chip in the width direction.

  The honing width is increased at a constant rate from the center of the cutting edge toward both ends, but the resistance given to the chips is also directed from the center to both ends in the width direction. Therefore, it is desirable that the concave portion can be smoothly rounded, that is, the concave portion has a groove shape with a concave V shape in section by a pair of inclined planes.

  Moreover, it is desirable that at least the periphery of the intersecting ridge line portion between the rake face of the cutting edge portion and the front flank surface of the insert body is formed of a CBN sintered body or a diamond sintered body. Excellent wear resistance can be ensured by forming the periphery of the intersecting ridge line portion between the scoop surface of the cutting edge portion where the chip is scraped by the sintered body and the cutting edge portion where the recess is formed, and the front flank surface.

  As described above, according to the present invention, chips are left behind on the workpiece and the machining accuracy is deteriorated, or the contact length in the width direction with the chips is increased and the cutting resistance is not increased. Can be surely divided in the outflow direction after being rounded in the width direction, and chip disposal can be improved.

It is a perspective view which shows one 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 the front view which looked at embodiment shown in FIG. 1 from the cutting blade part side. It is a rear view of the arrow X direction view in FIG.

  1 to 5 show an embodiment of the present invention. In the present embodiment, the insert body 1 has a substantially quadrangular prism shape, and a cutting edge portion 2 is formed at one end portion (left end portion in FIGS. 1 to 3) in the longitudinal direction (left and right direction in FIGS. 1 to 3). In addition, the other end side portion (the right side portion in FIGS. 1 to 3) is a mounting portion 3 for mounting the insert body 1 to a holder of a fluted / cut-off tool of a blade edge exchange type.

  Among these, the cutting edge portion 2 has a front flank 4 facing one end in the longitudinal direction and a rake face 5 (surface facing the upper side in FIG. 3) that intersects the front flank 4 and extends in the longitudinal direction. And a pair of lateral relief surfaces 6 (surfaces facing in the left-right direction in FIG. 4) extending in the longitudinal direction so as to intersect with the front relief surface 4 and also with the rake surface 5, A cutting edge 7 (front cutting edge) is formed at the intersection ridge line with the front flank 4. A seating surface 8 is formed on the surface opposite to the rake surface 5 over the entire length of the insert body 1.

  The seating surface 8 and the mounting surface 3A facing the opposite side of the seating surface 8, that is, the same side as the rake face 5 in the mounting portion 3, are grooves extending in the longitudinal direction with a V-shaped cross section as shown in FIG. However, the groove surface is a convex curved surface that curves so as to be convex toward the inside of the V-shape. The insert body 1 of the present embodiment has a symmetrical shape with respect to the plane extending in the longitudinal direction along a concave V-shaped bisector formed by the cross sections of the seating surface 8 and the mounting surface 3A. .

  In such an insert main body 1, the seating surface 8 and the mounting surface 3 </ b> A come into contact with an inclined plane having a convex V-shaped cross section formed so as to protrude opposite to the pair of jaw portions of the holder. By being pressed so as to be inserted, the cutting blade portion 2 is fixed and attached to the holder so as to protrude.

  Here, the insert body 1 is formed of a hard material such as cemented carbide except for one end side portion of the rake face 5, and the one end side portion of the rake face 5 is formed of a CBN sintered body or a diamond sintered body. An ultra-high hardness sintered body 9A such as a bonded body and a hard sintered body 9B such as a cemented carbide alloy are integrally formed in a layered sintered body 9, and the cutting blade 7 is formed by the layered sintered body. 9 is formed in the ultra-high hardness sintered body 9A portion. In addition, the width W of this cutting blade 7 shall be about 2 mm-6 mm, for example.

  That is, as shown in FIG. 3, a pair of lateral flank surfaces extends from the front flank surface 4 to about half the longitudinal direction of the rake surface 5 at the intersecting ridge line portion between the rake surface 5 and the front flank surface 4 of the cutting edge portion 2. A notch 2A is formed so as to be cut out in an L-shape between 6 and 6. In the notch 2A, the layered sintered body 9 has its super-hard sintered body 9A portion on the rake face 5 side. The hard sintered body 9 </ b> B is fixed by being brazed to the notch 2. The surface of the layered sintered body 9 fixed in this manner is arranged so as to be flush with the front flank 4, the rake face 5, and the side flank 6 of the cutting edge portion 2.

  Further, the rake face 5 has a flat shape along the longitudinal direction, and the front flank face 4 is given a clearance angle so as to recede in the longitudinal direction as it moves away from the rake face 5 toward the seating face 8 side. It is made the inclined plane shape. Further, the pair of lateral clearance surfaces 6 are also inclined so as to approach each other as they move away from the rake surface 5 and toward the seating surface 8 side, and away from the front clearance surface 4 toward the other end in the longitudinal direction. Are inclined so as to be close to each other, and are inclined to have a clearance angle.

  Therefore, in this embodiment, the cutting edge 7 is formed to extend in a straight line in a direction orthogonal to the longitudinal direction in a plan view facing the rake face 5. However, the intersecting ridge line portion between the front flank 4 and the side flank 6 is chamfered in an arc shape in cross section, and therefore, a substantially arcuate corner blade 7A is formed at both ends of the cutting blade 7. The radius of the arc formed by the corner blade 7A is preferably 0.5 mm or less.

  Further, honing is applied to the cutting edge 7, and the rake line 5 and the front flank 4 are formed at the intersection ridge line portion between the rake face 5 and the front flank 4 on which the cutting edge 7 is formed. The honing surface 10 is formed so as to be continuous with. Here, the honing in the present embodiment is a planar chamfer honing in which the honing surface 10 intersects the rake face 5 and the front flank 4 with an obtuse angle, and the honing angle α with respect to the rake face 5 is For example, the honing width A in the longitudinal direction along the rake face 5 is set to be larger than the radius of the arc formed by the corner blade 7A.

  A concave portion 11 is formed in the intersecting ridge line portion between the honing surface 10 and the rake surface 5 along the intersecting ridge line portion. 2 is the largest and deepest at the center in the width direction of the blade 7 (vertical direction in FIG. 2; left and right direction in FIGS. 4 and 5), and shallower toward both ends of the cutting blade 7 in the width direction. . However, the concave portion 11 does not cross the front flank 4 even at the center of the cutting edge 7, that is, the concave portion 11 is recessed beyond the cross ridge line portion of the honing surface 10 and the front flank surface 4, and the cross ridge line portion is It is formed so that it does not become a middle dent shape.

  In particular, in this embodiment, the recess 11 does not reach the intersecting ridge line portion between the honing surface 10 and the front flank 4, that is, from the intersecting ridge line portion between the honing surface 10 and the front flank 4. The honing width B up to the intersecting ridge line with 10 is not 0 at the center of the cutting edge 7 and increases from the center toward both ends of the cutting edge 7. Here, the honing width B at the central portion of the cutting edge 7 is preferably in the range of 0 mm <B ≦ 0.1 mm in the direction along the rake face 5.

  Furthermore, in the present embodiment, the recess 11 is viewed from a direction inclined at an inclination angle β of, for example, 20 ° that is gentler than the honing angle α with respect to the rake face 5 toward the one end side in the longitudinal direction. As shown in the figure, it is formed to have a flat V-shaped cross section. That is, the concave portion 11 is formed so as to cut out the intersecting ridge line portion between the honing surface 10 and the rake face 5 by a flat groove having a concave V-shape extending along the direction inclined at the inclination angle β. The groove bottom of the concave V-shaped groove does not reach the intersecting ridge line portion of the honing surface 10 and the front flank 4 but is positioned at the center in the width direction of the cutting edge 7 on the honing surface 10. ing.

  In addition, the concave portion 11 is raised without reaching both end portions of the cutting blade 7 in the width direction of the cutting blade 7, so that a honing surface is formed between the both end portions of the concave portion 11 and the side clearance surface 6. 10 and the rake face 5 are left with a slight width C of about 0.5 mm or less in the width direction of the cutting edge 7, for example. Note that the remaining intersection ridge line portion may be further subjected to round honing or chamfer honing.

  Further, as described above, the recess 11 is formed in a groove shape having a V-shaped cross section and is formed so as to cut out the intersecting ridge line portion between the honing surface 10 and the rake face 5 at a constant inclination angle β. The honing width in the direction along the rake face 5 from the intersecting ridge line portion between the front flank 10 and the front flank 4 to the intersecting ridge line portion between the concave portion 11 and the honing surface 10 is the center in the width direction of the cutting edge 7 in this embodiment. From the smallest honing width B of the cutting edge 7 to the both ends of the cutting edge 7, gradually increased at a constant rate, and then the honing width A is reached when the both ends are cut off. Then, except for the corner blade 7A, a constant honing width A is set so that the honing surface 10 intersects the lateral clearance surface 6.

  Furthermore, the flat cross-sectionally concave V-shaped groove forming the concave portion 11 in this embodiment is a honing surface 10 and a rake surface by a pair of inclined planes 11A inclined so as to approach each other toward the groove bottom side. The pair of inclined planes 11A intersecting each other at an obtuse angle at the groove bottom of the concave V-shaped groove are formed as a rake face 5 and a honing face 10. And the recess 11 is formed so as to intersect the obtuse angle.

  Here, as in the present embodiment, the honing angle α is 45 °, the inclination angle β with respect to the rake face 5 of the recess 11 is 20 °, and the width C of the intersecting ridge line portion between the honing face 10 and the rake face 5 is 0. When 5 mm is left, when the width of the cutting edge 7 is changed within the range of 2 mm to 6 mm and the honing width B is changed within the range of 0 mm to 0.1 mm, as seen from the direction inclined at the inclination angle β as shown in FIG. The angle γ formed by the extended surfaces of the pair of inclined planes 11A with respect to the intersecting ridge line portion between the honing surface 10 and the rake face 5 intersecting the inclined plane 11A is approximately 4 ° 52 ′ to 24 ° 41 ′. It will change within the range.

  In the grooving / parting-off cutting insert constructed as described above, the cross ridge line between the rake face 5 and the front flank 4 on which the cutting edge 7 used for grooving / parting-off into the work material is formed. The honing surface 10 is formed in the part, and the intersecting ridge line portion between the honing surface 10 and the front flank 4 substantially acts as a cutting edge and bites the work material, and cuts the work material. Go. Then, the chips generated at this time flow out from the honing surface 10 by rubbing the rake surface 5.

  However, a recess 11 is formed on the honing surface 10 so that the honing width increases from the center portion of the cutting edge 7 toward both end portions. The resistance at the both ends in the width direction of the cutting edge 7 is greater than that at the center. Therefore, by giving such resistance, the chips are deformed so as to be rounded toward the central portion where the resistance is small in the width direction of the chips, and then rubbed out on the rake face 5 to flow out. Even in the outflow direction, it is deformed so as to be rounded by receiving resistance.

  For this reason, in the chip, stress concentrates at the center part in the width direction or at both ends or both, and breaks. As a result, the chip is finely divided while being curled in the outflow direction. Therefore, according to the cutting insert having the above-described configuration, it is possible to prevent a situation in which chips generated during grooving and parting work flow out continuously and get entangled with the holder or damage the work material. And good chip disposal can be ensured.

  On the other hand, the concave portion 11 does not intersect the front flank 4, that is, until reaching the intersection ridge line portion between the front flank surface 4 and the honing surface 10, or with this intersection ridge line portion. Since the honing surface 10 is left between the gaps (the honing width B in the direction along the rake face 5), the front flank 4 and the honing acting as the cutting edge as described above are formed. The intersecting ridge line portion with the surface 10 continues to extend in a straight line, and does not become an indented shape like the insert described in Patent Document 1.

  For this reason, in particular, when grooving the work material, the projecting portion due to the center recess shape of the cutting edge is not left uncut at the bottom of the groove of the processed work material. It is possible to improve machining accuracy and machining quality while maintaining machining efficiency without requiring additional machining for removing uncut residue.

  In addition, since the cutting edge does not have an indented shape in this way, in the cutting insert configured as described above, the generated chips do not have an indented shape in the cross section and are generated so as to extend linearly in the width direction. Then, by rubbing the rake face 5 from the honing face 10, it is rounded in the width direction and the outflow direction to be well curled and divided. For this reason, if the width of the cutting edge 7 is the same, the contact length with the chips along the width direction can be kept shorter than that of the middle-dented shape, thereby reducing the cutting resistance. it can.

  In particular, in the present embodiment, the periphery of the intersecting ridge line portion between the rake face 5 and the front flank face 4 in the cutting edge portion 2 of the insert body 1 is a super-layered sintered body 9 made of a CBN sintered body or a diamond sintered body. The high-hardness sintered body 9A is formed of a high-hardness sintered body 9A. Since the ultra-high-hardness sintered body 9A is super-hard, it has high wear resistance but has low toughness. In the case of continuous action during a relatively long machining time, chipping tends to occur at the cutting edge. In addition, when a large cutting force acts continuously in this manner, the cutting heat increases and the wear of the rake face 5 is promoted.

  In this regard, in a grooving / parting-off cutting insert in which the entire insert body is formed of cemented carbide or ceramics, protrusions are formed on the rake face as described in, for example, Japanese Patent Application Laid-Open No. 2006-150584. However, it is difficult to form such protrusions on an ultra-high hardness sintered body, and the toughness is poor, in other words, the brittleness is high. Even if a protrusion is formed in the ultra-high hardness sintered body, it is easily broken, resulting in loss of chip disposal.

  However, in the cutting insert for grooving and parting off having the above-described configuration, it is possible to reduce the cutting resistance as described above without providing such a projection, thereby preventing chipping of the cutting edge 7. However, it is possible to effectively exhibit the high wear resistance of the ultra-high hardness sintered body 9A.

  However, even if the cutting resistance can be reduced in this way, the honing width B, which is the smallest in the central portion of the cutting edge 7, is 0, that is, the concave portion 11 is in the honing surface 10 in the central portion of the cutting edge 7. If it seems to reach the intersection ridge line part with the front flank 4, the honing surface 10 does not exist at the center of the cutting edge 7, and the cutting edge 7 may be damaged or chipped due to insufficient strength.

  On the other hand, if the honing width B at the central portion of the cutting edge 7 is too large, the cutting resistance is increased, and the chips are rounded in the outflow direction before being rounded in the width direction and are curled as they are. Therefore, there is a possibility that it is not possible to effectively promote cutting of chips due to stress concentration. For this reason, the honing width B at the center of the cutting edge 7 is larger than 0, and the width in the direction along the rake face 5 is within the range of 0 mm <B ≦ 0.1 mm as in this embodiment. Is desirable.

  The concave portion 11 may be formed so as to intersect the lateral clearance surface 6, that is, the concave portion 11 is formed over the entire length of the intersecting ridge line portion between the honing surface 10 and the rake surface 5. In particular, as in the present embodiment, the periphery of the intersecting ridge line portion between the rake face 5 and the front flank 4 of the cutting edge portion 2 where the cutting edge 7 is formed is formed by the ultra-high hardness sintered body 9A. In addition, since the toughness is poor at the intersecting ridge line portion between the concave portion 11 and the side flank 6, there is a possibility that a defect or the like is likely to occur.

  Further, when the concave portion 11 is formed over the entire length of the intersecting ridge line portion between the honing surface 10 and the rake face 5, the honing width when the honing width at both ends of the cutting edge 7 does not form the concave portion 11 is obtained. It becomes smaller than the width A, and there is a possibility that it becomes difficult to give sufficient resistance to the chips and to round in the width direction.

  For this reason, the concave portion 11 is cut off without reaching both ends of the cutting edge 7, and the intersecting ridge line portion of the honing surface 10 and the rake face 5 is formed at both ends of the cutting edge 7 as in the present embodiment. It is desirable to leave with a width C of about 0.5 mm or less. As a result, a large honing width A can be secured at both ends of the cutting edge 7 to provide sufficient resistance to the chips while maintaining toughness and strength, and the chips are more reliably rolled up in the width direction and divided. It becomes possible.

  Further, in the present embodiment, the recess 11 is formed by a groove having a concave V-shaped cross section by a pair of inclined planes 11 </ b> A, and the recess 11 and the honing surface from the intersecting ridge line portion of the honing surface 10 and the front relief surface 4. The honing width to the intersecting ridge line portion with 10 is increased at a constant rate from the center portion of the cutting edge 7 toward both end portions. For example, a pair of grooves forming the concave V-shaped groove is formed. The rate at which the honing width increases from the center portion of the cutting edge 7 toward both end sides due to the inclined surface being bent or conversely bent when viewed from the direction of the inclination angle β is small. It may be changed to become larger or larger.

  However, when the pair of inclined surfaces having a V-shaped cross section are curved as in the former and the rate of increase in the honing width decreases from the central portion of the cutting blade 7 toward both ends, the central portion of the cutting blade 7 On the other hand, the range in which the resistance given to the chips is reduced becomes smaller, and conversely, like the latter, the ratio of the pair of inclined surfaces being concave and the honing width increasing is directed from the center of the cutting edge 7 toward both ends. Even if it becomes large, it becomes impossible to give sufficient resistance to the chip at both ends of the cutting edge 7, and in any case, the chip is cut by surely rounding the chip in the width direction and then curling it in the outflow direction. May be difficult.

  For this reason, the concave portion 11 is formed by a pair of inclined flat surfaces 11A as in the present embodiment so that the honing width increases at a constant rate from the center portion of the cutting edge 7 toward both end portions. It is desirable to form the groove shape. As a result, the resistance given to the chips also increases at a constant rate in the width direction from the center to both ends, so that the chips can be smoothly rounded in the width direction and rounded in the outflow direction. By curling, more reliable chip disposal can be promoted.

  In the present embodiment, the periphery of the intersecting ridge line portion between the rake face 5 where the cutting edge 7 is formed in the cutting edge 2 of the insert body 1 and the front flank 4 is made of a CBN sintered body or a diamond sintered body. Although the case where it was formed by the ultra-high hardness sintered body 9A has been described, as described above, the entire insert body 1 is formed by a hard material such as a cemented carbide having a lower hardness than a CBN sintered body or a diamond sintered body. It is also possible to apply the present invention to a cutting insert.

  In this embodiment, the cutting edge 7 extends so as to be orthogonal to the longitudinal direction of the insert body 1. However, in the cutting insert for parting-off processing, the cutting edge 7 extends obliquely with respect to the longitudinal direction of the insert body 1. May be. Furthermore, the cutting blade part 2 may be formed in the both ends of the longitudinal direction of the insert main body 1, or the cutting blade part 2 may be formed by using each corner | angular part of a triangular plate-shaped insert main body as an edge part.

  Hereinafter, in the cutting insert for grooving / parting-off processing according to the present invention, how the chip disposability changes when cutting with a different honing width B will be described with reference to examples. In this example, in the two types of cutting inserts in which the width W of the cutting edge 7 based on the above embodiment is 2 mm and 5 mm, the honing angle α is 45 °, the honing width A is 0.445 mm, and the inclination angle β is Manufacturing a total of eight cutting inserts with the angle γ varied so that the honing width B is 0.1 mm, 0.05 mm, 0.02 mm, and 0 mm, respectively, at 20 ° and the width C of 0.5 mm. did. These are referred to as Examples 1 to 8 as shown in Tables 1 and 2 for each of the width W, the angle γ, and the honing width B of the cutting edge.

  And the grooving process was performed to the work material with the cutting inserts of Examples 1 to 8, and the state of the chips at that time was confirmed. The results are shown in Tables 1 and 2. The cutting conditions were a cutting speed of 150.0 mm / min and a feed of 0.076 mm / rev, and chlorine-free emulsion GE330 (5%) was used as a coolant. The work material was a sintered material for sprockets.

  From Tables 1 and 2, in any of Examples 1 to 8 in which the width W of the cutting edge is 2 mm and 5 mm, the chips are generally divided and good results are obtained. In particular, in Examples 3, 4, 7, and 8 in which the honing width B is 0 mm to 0.02 mm, the chip is divided before curling once in the longitudinal direction and the curl diameter is suppressed to be small. Good results have been obtained for curling. However, when the honing width B is 0 mm, the cutting edge may be damaged as described above, and therefore the honing width B is preferably not 0.

DESCRIPTION OF SYMBOLS 1 Insert body 2 Cutting edge part 4 Front flank 5 Rake face 7 Cutting edge 9 Layered sintered body 9A Super-hard sintered body 10 Honing surface 11 Recess 11A Inclined plane A Honing width of honing surface 10 B Center of cutting edge 7 Honing width C at the edge C The width of the ridge line intersection between the honing surface 10 and the rake face 5 at both ends of the cutting edge W W The width of the cutting edge α Honing angle β The inclination angle of the recess 11 γ The extended surface of the inclined plane 11A Angle formed with respect to the intersecting ridge line portion between the surface 10 and the rake surface 5

Claims (5)

A cutting blade having a honing surface connected to the rake face and the front flank face is formed at the intersection ridge line portion of the rake face and the front flank face of the cutting edge portion provided at the end of the insert body. In the intersection ridge line portion between the honing surface and the rake surface, a concave portion is formed so as not to intersect the front flank surface, and the honing surface has a constant inclination angle that is gentler than the honing angle with respect to the rake surface. And the honing width from the intersecting ridge line portion between the honing surface and the front flank surface to the intersecting ridge line portion between the concave portion and the honing surface is formed. A cutting insert for grooving and parting off, characterized in that it increases from the central portion of the cutting blade toward both end portions of the cutting blade.   2. The grooving / cut-off according to claim 1, wherein the honing width B at the center of the cutting edge is in a range of 0 mm <B ≦ 0.1 mm in the direction along the rake face. Cutting insert for machining.   The cutting insert for grooving / parting-off processing according to claim 1 or 2, wherein the concave portion has a groove shape with a concave V-shaped cross section by a pair of inclined planes.   The cutting insert for grooving / parting-off processing according to any one of claims 1 to 3, wherein the recess is cut without reaching both ends of the cutting blade.   The at least the periphery of the intersecting ridge line portion between the rake face of the cutting edge and the front flank of the insert body is formed of a CBN sintered body or a diamond sintered body. Cutting insert for grooving / parting-off processing according to any one of the above.

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