JP2009291925A - Cutting insert and insert detachable cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting insert and an insert detachable cutting tool which has recesses formed in respective end faces thereof for ensuring the mounting strength and stability thereof, without damaging the rigidity and strength of cutting edge portions, and does not damage the seating stability thereof when the cutting edge portions for use in cutting are exchanged for new ones. <P>SOLUTION: According to the structure of the cutting insert, a bottom surface extending in a longitudinal direction of a shaft-shaped insert main body 1 serves as a seating surface 8, and the pair of cutting edge portions 2 each having a cutting edge 4 with a raking face 5 that faces a side opposite to the seating surface 8, are formed at both longitudinal ends of the insert. A recess 12 is formed in each end face 11 facing in a longitudinal direction of the cutting edge portion 2, at a location on the seating surface 8 rather than a flank 9 of the cutting edge 4 such that a cross section in parallel with the raking face 5 is dented like the V shape in the longitudinal direction and that a dent volume and an opening width in the end face 11 are progressively increased in a location closer to the seating surface 8. V-shaped ridge bottom lines O of the recess toward the seating surface 8 are extended in directions that cross each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cutting insert used for grooving, parting off or copying of a work material in turning, and an insert detachable cutting tool to which the cutting insert is detachably mounted.

  As a cutting insert used for such grooving or parting-off processing, for example, in Patent Document 1, a pair of cutting blade portions having cutting edges at both longitudinal ends of a shaft-shaped insert body are formed. The bottom surface extending in the longitudinal direction of the insert body is a seating surface to the insert mounting seat formed on the tool body of the insert detachable cutting tool, and the seating surface has a concave V shape in a cross section orthogonal to the longitudinal direction. There has been proposed a seat which is formed so as to be in contact with a contact surface having a convex V-shaped cross section of the insert mounting seat.

  However, in the cutting insert described in Patent Document 1, both end surfaces of the pair of cutting blade portions facing the longitudinal direction of the insert body are simply flat surfaces except for the flank surface of the cutting blade. Since it is only mounted in contact with the flat surface formed at the back of the insert mounting seat, for example, the cutting insert is sent out in the direction of the axis of rotation of the work material rotating in turning, and the groove width of the machining groove When expanding or copying, there is a risk that the cutting insert may be displaced in the direction of the rotation axis, thereby impairing the processing accuracy and processing quality.

Therefore, for example, in Patent Documents 2 and 3, both end surfaces of a pair of cutting blade portions facing the longitudinal direction of these insert main bodies have a concave V-shaped cross section parallel to the rake face of the cutting blade portions. In addition to forming a concave recess, a convex part that contacts the concave part is provided at the back of the insert mounting seat, and when one cutting blade part is used for cutting, the concave part of the end face of the other cutting blade part is brought into contact with the convex part There has been proposed an insert in which the cutting insert is positioned in the rotational axis direction of the work material so as to ensure the insert mounting strength and stability.
Japanese Patent Laid-Open No. 11-10411 Japanese Patent Laid-Open No. 10-315012 JP-A-3-3170205

  However, among these, in the cutting insert described in Patent Document 2, the concave portion having a V-shaped cross section is a V-shaped groove having a constant depth and width recessed from directly under the flank of the cutting edge at the end face of the cutting edge. For this reason, the thickness of the insert main body is reduced by the fact that the end surface immediately below the cutting edge is greatly recessed in the direction in which the main component force acts during cutting. For this reason, the rigidity and strength of the cutting edge part may be impaired, and vibration or the like may easily occur during cutting, or the cutting edge part may be damaged.

  On the other hand, in the cutting insert described in Patent Document 3, the rake surfaces of the pair of cutting blade portions are formed so as to face each other, and these rake surfaces can be used to change the cutting blade portion used for cutting. The insert body is rotated so as to reverse the front and back surfaces, so that the seating surface is also formed on the back side of each rake face with a pair of cutting blades in opposite directions, and further on the end face. The concave portion also extends so that the V-shaped valley bottom lines formed by the cross section thereof are parallel to each other. However, in such a cutting insert, when one cutting edge part is used for cutting, the seating surface of the other cutting edge part is arranged continuously with the rake face of this one cutting edge part. If the seating surface of the other cutting edge is worn by the chips generated at that time, there is a possibility that the insert seating property when the other cutting edge is cut next becomes unstable.

  The present invention has been made under such a background. As described above, the cutting edge portion is used to form the recesses on the end surfaces of the pair of cutting edge portions to ensure the mounting strength and stability of the cutting insert. It is an object of the present invention to provide a cutting insert and an insert detachable cutting tool which do not impair the seating stability when the cutting edge portion used for cutting is changed without impairing the rigidity and strength of the cutting tool.

  In order to solve the above problems and achieve such an object, a cutting insert according to the present invention has a bottom surface extending in the longitudinal direction of an insert body having an axial shape as a seating surface. A cutting insert in which a pair of cutting blade portions each having a cutting edge having a rake face facing away from the seating surface is formed at both ends in the longitudinal direction, and the cutting inserts of the pair of cutting blade portions The both end faces facing the longitudinal direction are recessed in the longitudinal direction so that the cross section parallel to the rake face is V-shaped on the seating surface side of the flank face of the cutting blade, and the amount of the recess And the opening width in the cross section on the end face side is formed with a concave portion that gradually increases toward the seating surface side, and the V-shaped valley line formed by the cross section of these concave portions toward the seating surface side. Extension lines of each other Characterized in that it extends in a direction difference.

  Further, the insert detachable cutting tool of the present invention is such that the cutting insert of the present invention seats the seating surface on the insert mounting seat formed on the tool body and one of the pair of cutting blade portions. An insert detachable cutting tool that is detachably mounted with a cutting edge projecting, wherein the insert mounting seat abuts on the recess formed on the end face of the other cutting edge of the cutting insert. A convex portion is formed.

  In the cutting insert having the above configuration, one bottom surface of the insert body is used as a seating surface, and a recess formed on the end surface of the cutting edge at both longitudinal ends is a seating surface of a V-shaped valley bottom line formed by the cross section. The extension lines to the sides extend in a direction intersecting each other. Therefore, when changing the cutting edge portion used for cutting in the insert detachable cutting tool having the above configuration, the bisectors of these intersecting extension lines are rotated. By rotating the insert body and reattaching it to the insert mounting seat, the concave portion can be brought into contact with the convex portion while the seating surface is common. For this reason, no matter which cutting edge part is used for cutting, the seating surface is not worn by chips.

  And this recessed part is formed so that the amount of the recessed part and the opening width in the said cross section in the said end surface side may become large gradually as it goes to the seating surface side, conversely, the cutting blade side opposite to this seating surface Since both the dent amount and the opening width are made small, it is possible to avoid the end face from being greatly recessed immediately below the cutting edge and the thickness of the insert body from being shaved. For this reason, the cutting edge rigidity and strength of one of the cutting edges used for cutting can be sufficiently ensured, and the insert mounting strength and stability can be ensured by the recess in the other cutting edge. Therefore, it becomes possible to perform high-precision and high-quality cutting.

  Here, it is desirable that the crossing angle between the extended lines to the seating surface side of the valley bottom line is within a range of 30 to 120 °, and when the crossing angle is smaller than this range, the dent amount of the recess also on the seating surface side. However, if the crossing angle is larger than this range, the amount of dent on the seating surface side will increase, and how the rigidity just below the cutting edge will increase. Even if the strength is ensured, there is a risk that the entire cutting edge portion is likely to be vibrated or damaged.

  The distance between the cutting edge and the opening end of the concave portion on the cutting edge side is preferably within a range of 1.5 to 3 mm in a direction perpendicular to the longitudinal direction. If the interval is small, that is, if the opening end of the recess is too close to the cutting edge, vibration and damage are likely to occur, and the recess may be deformed due to wear of the flank of the cutting edge. If the distance is large, there is a risk that a sufficiently large concave portion cannot be formed depending on the size of the end face.

  Further, in the end surfaces of the pair of cutting blade portions, it is desirable that the periphery of the opening of the concave portion on the seating surface side with respect to the flank surface of the cutting blade is a flat surface extending in a direction perpendicular to the longitudinal direction. As a result, the thickness of the insert body on the seating surface side of the flank just below the cutting edge can be more reliably ensured, and the rigidity and strength of the cutting edge can be improved. Furthermore, if a recess recessed from the seating surface or the side surface is formed on the seating surface of the insert body or the side surface of the insert body that intersects the seating surface and extends in the longitudinal direction, the recess formed on the end surface In combination, it is possible to promote weight reduction of the insert body and improvement of heat dissipation of the cutting heat by increasing the surface area of the insert body.

  As described above, according to the cutting insert and the insert detachable cutting tool of the present invention, the seating surface formed on the bottom surface of the insert body 1 is not worn by chips, so that the seating of the cutting insert is always performed. Stability can be maintained, and the recess formed on the end face ensures the mounting rigidity and strength of the cutting insert, as well as the cutting edge rigidity and strength of the cutting edge used for cutting. This makes it possible to improve the processing accuracy and processing quality.

  1 to 6 show a first embodiment of a cutting insert of the present invention. In the present embodiment, the insert body 1 is formed of a hard material such as cemented carbide and has a substantially square shaft shape (square column shape) extending along the axis L. The insert body 1 is perpendicular to the axis L and is in the longitudinal direction. (Axis L direction. Left and right direction in FIGS. 2 to 4) It is formed substantially symmetrically with respect to the plane M located in the center, and is perpendicular to the plane M in the width direction (in FIGS. 2 and 4). Up and down direction (left and right direction in FIG. 5) is located symmetrically with respect to a plane N that is located in the center and extends in the thickness direction of the insert body 1 (up and down direction in FIGS. 3 and 5) including the axis L. It is also formed 180 degrees rotationally symmetric with respect to the center line C in the longitudinal direction of the insert body 1 that is the intersection of these planes M and N.

  Cutting edge portions 2 are formed at both ends of the insert body 1 in the longitudinal direction. The cutting blade portions 2 include a pair of horizontal cutting blades 3 extending in the longitudinal direction and the horizontal cutting blades. The rake face 5 having a substantially rectangular shape extending in the longitudinal direction and having a cutting edge with the front cutting edge 4 extending in the width direction between the front ends of the three edges is formed between the pair of cutting edges 2. In the present embodiment, it is formed parallel to the axis L so as to face the same side in the thickness direction. Note that the corner portion 6 where the front cutting edge 4 and the horizontal cutting edge 3 intersect each other has a cross section with the front cutting edge 4 and the horizontal cutting edge when viewed from a direction perpendicular to the longitudinal direction and facing the rake face 5. It is formed in a convex arc shape that smoothly contacts the blade 3.

  Further, the upper surface portion 7 of the insert body 1 facing the same side as the rake face 5 in the thickness direction between the cutting edge portions 2 at both ends in the longitudinal direction is thicker than these cutting edge portions 2 as shown in FIG. It protrudes one step in the vertical direction. Furthermore, mounting groove portions 7A and 8A having a V-shaped cross section over the entire length in the longitudinal direction are formed on the upper surface portion 7 and the bottom surface of one of the insert main bodies 1 opposite to the upper surface portion 7. These mounting groove portions 7A and 8A have a pair of jaws having mounting convex portions having a V-shaped cross section facing each other in an insert mounting seat formed on a tool body of an insert detachable cutting tool described later. The cutting insert is held by the insert mounting seat by being sandwiched between the parts. Therefore, the bottom surface serves as a seating surface 8 for the insert mounting seat, and the seating surface 8 is common to the pair of cutting blade portions 2. In addition, the end surface 7B facing the longitudinal direction of the upper surface portion 7 is an inclined surface that is inclined toward the seating surface 8 side as it goes toward the cutting edge portion 2 side.

  Furthermore, the front end surface facing the longitudinal direction and the both side surfaces facing the width direction of the cutting edge portion 2 are respectively the front cutting edge 4 and the flank 9 of the pair of side cutting edges 3, and the cutting insert of this embodiment These flank surfaces 9 are positive type inserts that are inclined so as to gradually recede toward the seating surface 8 side and away from the rake face 5 including the intersecting ridge line portion connected to the corner portion 6. Has been. A pair of side surfaces 10 extending in the longitudinal direction intersecting the seating surface 8 of the insert main body 1 other than the flank 9 of the cutting blade portion 2 and an end surface 11 of the cutting blade portion 2 facing the longitudinal direction are as follows. In this embodiment, the end surface 11 is a flat surface extending perpendicularly to the longitudinal direction.

  Further, a concave portion 12 is formed on the end surface 11 on the seating surface 8 side of the flank 9 of the front cutting edge 4. The recess 12 is recessed in the longitudinal direction so that the cross section parallel to the rake face 5 forms a V shape, and the cross section perpendicular to the longitudinal direction is also recessed toward the rake face 5 side so as to form a V shape. That is, the end portion of the insert body 1 from the end surface 11 to the seating surface 8 has a valley line O on the plane N and recedes in the longitudinal direction toward the seating surface 8 side. The V-shaped groove extending in an inclined manner is cut out.

  Therefore, the amount of the recess 12 from the end surface 11 to the valley bottom line O gradually increases toward the seating surface 8 as shown in FIG. 3, and the opening width in the cross section on the end surface 11 side, that is, the width described above. As shown in FIG. 5, the opening width in the direction gradually increases toward the seating surface 8, and this opening width is made equal to the groove width of the mounting groove 8 </ b> A at the intersection with the seating surface 8. Moreover, in the said end surface 11, the opening part periphery of this recessed part 11 in the seating surface 8 side rather than the flank 9 is made into the flat surface extended in the direction perpendicular | vertical to the said longitudinal direction. Further, the valley lines O of the recesses 12 formed in the pair of cutting blade portions 2 are equal to the center line C on the center line C as shown in FIG. It extends in a direction that intersects at an angle, and the intersection angle θ is in the range of 30 to 120 ° in this embodiment.

  The interval P between the cutting edge (front cutting edge 4) and the opening end of the recess 12 on the cutting edge side, that is, the intersection of the end face 11 and the valley line O is perpendicular to the longitudinal direction as shown in FIG. In a range of 1.5 to 3 mm. The pair of inclined surfaces forming the V-shape formed by the recess 12 is a contact surface 12A to the convex portion of the insert mounting seat, which will be described later, and in this embodiment, the cross-sectional concave V-shape of the seating surface 8 is formed. The valley bottom 12B of the recess 12 along the valley bottom line O intersected with the pair of inclined surfaces of the mounting groove portion 8A formed, and the abutting surface 12A intersects, is a concave concave section that smoothly contacts the contact surface 12A. It is arcuate.

  As shown in FIGS. 7 to 10, the cutting insert configured as described above is used by being mounted on a tool body 21 of an insert detachable cutting tool. The tool body 21 is formed of a steel material or the like, and as shown in FIGS. 11 to 13, the rear end side (the right side in FIGS. 7 to 9, and FIGS. 11, 12, and 14) has a regular rectangular column-shaped shank portion 22. And a head portion 23 that protrudes from the top surface of the shank portion 22 on the tip side (left side in FIGS. 7 to 9, and FIGS. 11, 12, and 14). Yes.

  The head portion 23 is formed with a slit 24 extending from the tip thereof so as to extend along the extended surface of the upper surface of the shank portion 22, and a portion above the slit 24 is an upper jaw portion 25 and a lower portion. Is the lower jaw 26, and the upper and lower jaws 25, 26 constitute the pair of jaws. Here, the lower jaw portion 26 has a rectangular plate-like portion 26 </ b> A extending from the tip end surface of the tool main body 21 along one side surface of the shank portion 22, and the upper surface of the plate-like portion 26 </ b> A is the longitudinal direction of the tool main body 21. The above-mentioned attachment extending in the direction (front and rear end direction) so as to form a convex V-shaped cross-section with a concavity and convexity equal to the concave V-shape formed by the cross-section of the mounting groove 8B of the seating surface 8 of the insert body 1 It is the convex part 26B.

  On the other hand, the upper jaw portion 25 is formed with a triangular plate-like portion 25A extending on the attachment convex portion 26B at the distal end thereof, and the lower surface of the plate-like portion 25A facing the attachment convex portion 26B is also a tool body. 21. The mounting convex portion formed in a convex V-shaped cross section with the same angle as the concave V shape formed by the cross-section of the mounting groove portion 7A of the upper surface portion 7 of the insert body 1 in the longitudinal direction of the insert body 1 25B, and an interval portion between the mounting convex portions 25B and 26B of the upper and lower jaw portions 25 and 26 is an insert mounting seat 27.

  Then, on the back side (rear end side) of the insert mounting seat 27, an extension to the rear end side of the mounting convex portion 26 </ b> B is provided via a concave relief portion 27 </ b> A between the lower jaw portion 26 and the mounting convex portion 26 </ b> B. A convex portion 28 that engages with the concave portion 12 of the insert body 1 is formed on the upper side from the surface. That is, the convex portion 28 has a surface facing toward the tip side thereof having a convex V-shaped cross section in which the concave portion 12 is equal to the concave V shape formed in the cross section perpendicular to the valley bottom line O and the concave portion and convex portions are reversed. However, the ridge line portion is chamfered in a flat shape so as not to interfere with the valley bottom 12B.

  Further, the convex portion 28 intersects the concave V-shaped bisector formed by the cross-section of the mounting convex portion 26B at a half angle of the intersecting angle θ. It is formed so as to extend upward (upper jaw portion 25 side) toward the rear end side. Accordingly, the insert main body 1 is placed on the insert mounting seat 27 so that the mounting groove 8A of the seating surface 8 matches the concave and convex V shape of the cross section with the mounting convex portion 26B, and the tool main body 21 is directly placed on the rear end side. When pushed in, the concave portion 12 formed on the end surface 11 of the cutting blade portion 2 of the insert body 1 facing the rear end side makes the pair of contact surfaces 12A form the convex V-shape of the convex portion 28 on the tip side. The cutting insert is seated on the insert mounting seat 27 by being brought into contact with the convex portion 28 so as to abut the facing surface.

  Further, the head portion 23 has an upper jaw at a position away from the plate-like portions 25A, 26A in the thickness direction of the plate-like portions 25A, 26A (vertical direction in FIG. 8, left-right direction in FIGS. 10 and 13). An insertion hole 25C through which the clamp screw 29 is inserted is formed on the portion 25 side, and a screw hole (not shown) into which the clamp screw 29 is screwed is formed on the lower jaw portion 26 side so as to be coaxial with each other and substantially perpendicular to the slit 24. ing.

  Therefore, by screwing the clamp screw 29 and pressing the upper jaw portion 25 with its head, the upper jaw portion 25 is located on the lower jaw portion 26 side with the upper and lower jaw portions 25 and 26 on the rear end side of the slit 24 as the center. The mounting convex portion 25B on the lower surface of the plate-like portion 25A abuts on the mounting groove portion 7A on the upper surface portion 7 of the insert body 1 of the cutting insert seated on the insert mounting seat 27 as described above, and The insert body 1 is clamped so as to be pressed against the lower jaw portion 26 side, and the cutting insert is fixed and mounted.

  Note that the ridge line of the convex portion 28 of the insert mounting seat 27 and the ridge line of the mounting convex portions 25B and 26B having a convex V-shaped cross section are one piece passing through the center in the thickness direction of the plate-like portions 25A and 26A. When the cutting insert is mounted as described above, the plane and the plane N located at the center of the insert body 1 in the width direction coincide with each other. However, the ridges of the mounting projections 25B and 26B are also chamfered in a flat shape to avoid interference with the mounting grooves 7A and 8A of the insert body 1.

  Further, on the front end surface of the plate-like portion 26A of the lower jaw portion 26, a groove 26C having a V-shaped cross section having a bisector on the plane intersects the mounting convex portion 26B on the upper surface of the plate-like portion 26A. However, it is formed so as to extend downward to the middle of the tip surface. Here, the pair of groove surfaces constituting the V-shaped cross section of the recessed groove 26C are the above-mentioned pair of contact surfaces 12A of the recessed portion 12 directed to the tip end side of the tool body 21 of the cutting insert mounted as described above. It is supposed to cross.

  Therefore, according to the insert detachable cutting tool equipped with the cutting insert in this way, when one of the pair of cutting blades 2 of the insert body 1 is used for cutting, it is opposite to this. Since the concave portion 12 formed on the end surface 11 on the other cutting blade portion 2 side engages with the convex portion 28 of the insert mounting seat 27 by the abutment between the surfaces, the tool body 21 is cut off after grooving, for example. The material is fed in the direction of the axis of rotation (the width direction of the insert body 1 and the thickness direction of the plate-like portions 25A and 26A in the case of the insert-detachable cutting tool) to increase the groove width, or the outer periphery of the work material is rotated. Even when copying along the axial direction, the mounting strength and stability of the cutting insert can be secured, and the insert body 1 can be prevented from shifting in the rotational axis direction. The working surface of high quality can be formed on the workpiece with high precision.

  Moreover, in the cutting insert of the said structure, the one bottom face of the insert main body 1 is made into the seating surface 8 to the insert mounting seat 27, The said recessed part formed in the cutting blade part 2 of the longitudinal direction both ends of the insert main body 1 12 is formed on the side of the seating surface 8 so as to intersect with this one seating surface 8, and the extension lines to the seating surface 8 side of the V-shaped valley bottom line O formed by the cross section intersect each other. It extends to. Therefore, when the cutting blade portion 2 used for cutting is changed in the insert detachable cutting tool equipped with the cutting insert, the insert body 1 around the center line C, which is a bisector of the intersecting extension lines O, is inserted. And the recess 12 of the cutting edge 2 facing the rear end side of the tool body 21 is made into the convex portion 28 of the insert mounting seat 27 while the seating surface 8 is made common. They can be brought into contact with each other and engaged.

  And, since one bottom surface is common as the seating surface 8 of the pair of cutting blade portions 2 in this way, the rake face 5 of the cutting blade portion 2 is always facing the opposite side of the seating surface 8, Even if any of the cutting edge portions 2 is used for cutting, the seating surface 8 is not worn by chips generated during cutting. For this reason, according to the said cutting insert, the stable seating property can be maintained, and it is also compatible with the attachment strength and stability of a cutting insert being ensured by engagement of the uneven | corrugated | grooved part 12 and 28 as mentioned above. Thus, it is possible to further improve processing accuracy and processing quality.

  On the other hand, the concave portion 12 has a concave amount from the end surface 11, that is, a depth to the valley bottom 12 </ b> B and an opening width in the width direction of the insert body 1 in the end surface 11 gradually increases toward the seating surface 8 side. In other words, on the opposite side of the cutting edge (front cutting edge 4), both the dent amount and the opening width are reduced. It is possible to prevent the thickness of the insert main body 1 from being greatly shaved immediately below. And since it becomes possible to ensure the rigidity and intensity | strength of this cutting edge sufficiently by this, according to the cutting insert of the said structure, a vibration arises in the cutting-blade part 2 at the time of cutting, or a cutting edge is due to insufficient strength. It is possible to prevent the portion 2 from being damaged such as a defect, and it is possible to smoothly and stably perform the high-precision and high-quality cutting as described above.

  In particular, in the cutting insert of this embodiment, in the end surfaces 11 of the pair of cutting edges 2, the periphery of the opening of the recess 12 on the seating surface 8 side of the flank 9 of the cutting edge (front cutting edge 4) is the insert body. 1 is a flat surface extending in a direction perpendicular to the longitudinal direction of 1, thereby maintaining a larger wall thickness of the insert body 1 immediately below the cutting blade while maintaining the escape amount of the cutting blade. It is possible to further improve the cutting edge rigidity and strength.

  Further, in the present embodiment, as described above, the crossing angle θ of the valley bottom line O of the pair of recesses 12 at both ends of the insert body 1 in which the extended lines toward the seating surface 8 cross each other is 30 to 120. In the cutting edge portion 2 used for cutting, the cutting edge rigidity and strength are ensured in this way, while the cutting edge portion 2 side opposite to this has a convex portion 28. As a result, reliable seating stability can be obtained. That is, when the crossing angle θ is smaller than the above range, the recess 12 is too small on the seating surface 8 side, and the engagement with the projection 28 becomes insufficient, thereby ensuring sufficient mounting strength and stability. On the other hand, if the crossing angle θ is larger than the above range, the recessed amount of the recessed portion 12 becomes too large on the seating surface 8 side, and the entire cutting edge portion 2 becomes insufficient in rigidity and strength and vibrates. There is a risk of causing damage.

  Furthermore, in this embodiment, the space | interval P of the said cutting blade (front cutting blade 4) and the opening end of the recessed part 12 of this cutting blade side exists in the range of 1.5-3 mm in the direction perpendicular | vertical to the said longitudinal direction. This also ensures both cutting edge rigidity and strength and improved seating stability. That is, if the interval P is smaller than this range and the opening end of the recess 12 is too close to the cutting edge, the cutting edge rigidity and strength are still insufficient, and the main cutting force cannot be reliably received and vibration or damage occurs. In some cases, the flank wear of the cutting blade may reach the concave portion 12 and may cause deformation of the peripheral edge of the opening of the concave portion 12. Conversely, the interval P is larger than this range. Then, there is a possibility that the concave portion 12 becomes too small and the stability due to the engagement with the convex portion 28 cannot be sufficiently secured.

  Next, FIGS. 14 and 15 to 19 show first and second modified examples of the cutting insert of the first embodiment described above, respectively, and these modified examples and a second embodiment to be described later. Also in the cutting insert of the modified example, the same reference numerals are assigned to the portions common to the first embodiment, and description thereof is omitted. Among these, the 1st modification shown in FIG. 14 applies this invention to the so-called cutting insert with which the said front cutting edge 4 inclined toward the said width direction of the insert main body 1, and FIG. In the second modification shown in FIGS. 15 to 18, the present invention is applied to a cutting insert having a cutting edge formed in a circular shape.

  That is, in the first modified example shown in FIG. 14, the front cutting edge 4 protrudes with a certain inclination from one end to the other end in the width direction of the insert body 1 when viewed from the direction facing the rake face 5. So as to be inclined. Such a cutting insert is exclusively used for parting off the work material, and can prevent the core along the rotation axis from being left on the cut surface of the work material in the final parting process.

  In addition, in the second modification shown in FIGS. 15 to 19, the rake face 5 has a circular shape as shown in FIG. 16, and the cutting edge 30 is also viewed from the direction facing the rake face 5 accordingly. It has a circumferential shape. Such a cutting insert can finish the processed surface smoothly when the cutting insert is sent out in the direction of the axis of rotation, for example, by copying the outer peripheral surface of the work material.

  Next, in the second embodiment shown in FIGS. 20 to 22, a recess 31 that is recessed from the side surface 10 is formed on the side surface 10 excluding the pair of cutting blade portions 2 of the insert body 1. And That is, in the second embodiment, as shown in FIG. 22, a plurality of recesses 31 penetrating between the pair of side surfaces 10 of the insert body 1 are spaced in the longitudinal direction as viewed from the direction facing the side surfaces 10. It is formed to line up with a gap. Here, in the present embodiment, each of the recesses 31 has a semicircular arc shape that opens toward the seating surface 8 and protrudes toward the upper surface portion 7.

  23 to 25 show a first modification of the second embodiment in which the recess 32 penetrating between the pair of side surfaces 10 is the longitudinal direction as viewed from the direction facing the side surfaces 10. It has an oval shape extending in the direction. Furthermore, in the second modified example shown in FIGS. 26 to 28, a plurality of recesses 33 having a circular shape when viewed from the direction facing the side surface 10 are formed so as to penetrate between the pair of side surfaces 10 in the longitudinal direction. ing. Furthermore, in the 3rd modification shown in FIG. 29 thru | or FIG. 31, the recessed part 34 formed in the both side surfaces 10 does not penetrate, but has the bottom face 34A which faces the width direction of the insert main body 1. FIG.

  On the other hand, in the fourth modification shown in FIGS. 33 to 34, a recess 35 that is recessed from the seating surface 8 toward the upper surface portion 7 is formed not on the side surface 10 of the insert body 1 but on the bottom surface as the seating surface 8. Has been. The recess 35 is a blind hole having a circular cross section having a center on the plane N. In the fourth modification, a plurality of such recesses 35 having the same shape and size are arranged in the longitudinal direction. It is formed to line up at intervals.

  According to the cutting insert of such 2nd Embodiment and its modification, the effect similar to the said 1st Embodiment is acquired, and the lightweight of the insert main body 1 is formed by forming the recesses 31-35. Can be achieved. Further, the material cost of the insert body 1 can be reduced by the amount of the recesses 31 to 35, and the cost can be reduced. Further, since the surface area of the insert body 1 is increased by the recesses 31 to 35, the cutting is performed. The cutting heat transmitted from the cutting blade used sometimes can be efficiently dissipated, and damage to the insert body 1 due to the cutting heat can be effectively prevented.

It is a perspective view which shows 1st Embodiment of the cutting insert of this invention. It is the top view which looked at the cutting insert shown in FIG. 1 from the direction which opposes the rake face 5. FIG. It is the side view which looked at the cutting insert shown in FIG. It is the bottom view which looked at the cutting insert shown in FIG. 1 from the direction which opposes the seating surface 8. FIG. It is the front view which looked at the cutting insert shown in FIG. 1 from the direction which opposes the end surface 11. FIG. 1 is a bottom view of the cutting insert shown in FIG. 1 as viewed from a direction facing a seating surface 8 along a valley line O. FIG. It is a perspective view which shows one Embodiment of the insert detachable cutting tool of this invention. It is the top view which looked at the insert removable cutting tool shown in FIG. 7 from the direction which opposes the rake face 5 of a cutting insert. It is the side view which looked at the insert detachable cutting tool shown in FIG. 7 from the direction which opposes the side surface 10 of a cutting insert. It is the front view which looked at the insert attachment-detachment type cutting tool shown in FIG. 7 from the direction which opposes the end surface 11 of a cutting insert. It is a perspective view which shows the tool main body 21 of the insert detachable cutting tool shown in FIG. It is a side view of the tool main body 21 shown in FIG. It is a front view of the tool main body 21 shown in FIG. It is a top view which shows the cutting insert of the 1st modification of 1st Embodiment. It is a perspective view which shows the cutting insert of the 2nd modification of 1st Embodiment. It is the top view which looked at the cutting insert shown in FIG. 15 from the direction which opposes the rake face 5. FIG. It is the side view which looked at the cutting insert shown in FIG. 15 from the direction which opposes the side surface 10. It is the bottom view which looked at the cutting insert shown in FIG. 15 from the direction which opposes the seating surface 8. FIG. It is the front view which looked at the cutting insert shown in FIG. 15 from the direction which opposes the end surface 11. FIG. It is a perspective view which shows 2nd Embodiment of the cutting insert of this invention. It is the side view which looked at the cutting insert shown in FIG. 20 from the direction which opposes the side surface 10. It is aa sectional drawing in FIG. It is a perspective view which shows the cutting insert of the 1st modification of 2nd Embodiment. It is the side view which looked at the cutting insert shown in FIG. 23 from the direction which opposes the side surface 10. It is aa sectional drawing in FIG. It is a perspective view which shows the cutting insert of the 2nd modification of 2nd Embodiment. It is the side view which looked at the cutting insert shown in FIG. 26 from the direction which opposes the side surface 10. FIG. It is aa sectional drawing in FIG. It is a perspective view which shows the cutting insert of the 3rd modification of 2nd Embodiment. It is the side view which looked at the cutting insert shown in FIG. 29 from the direction which opposes the side surface 10. FIG. It is aa sectional drawing in FIG. It is a side view which shows the cutting insert of the 4th modification of 2nd Embodiment. It is the bottom view which looked at the cutting insert shown in FIG. 32 from the direction which opposes the seating surface 8. FIG. It is aa sectional drawing in FIG.

Explanation of symbols

1 Insert body 2 Cutting edge 4 Front cutting edge (cutting edge)
DESCRIPTION OF SYMBOLS 5 Rake face 8 Seating surface 9 Relief face of front cutting edge 4 10 Side face 11 End face 12 Recessed part 21 Tool body 27 Insert mounting seat 28 Convex part 31-35 Recess L 12 valley bottom line P interval between front cutting edge 4 and opening end of recess 12 intersection angle of extension line of valley bottom line O to seating surface 8 side

Claims (6)

  One bottom surface extending in the longitudinal direction of the shaft-shaped insert body is used as a seating surface, and both end portions of the insert body in the longitudinal direction are provided with rake surfaces facing away from the seating surface. A cutting insert in which a pair of cutting blade portions each having a blade is formed, and on both end surfaces facing the longitudinal direction of the pair of cutting blade portions, on the seating surface side than the flank surface of the cutting blade, A recess that is recessed in the longitudinal direction so that a cross section parallel to the rake face is V-shaped, and the amount of the recess and the opening width in the cross section on the end face side gradually increase toward the seating face side. A cutting insert characterized in that the extension lines of the V-shaped valley bottom lines formed by the cross-sections of these recesses to the seating surface side extend in directions intersecting each other.   The cutting insert according to claim 1, wherein an intersection angle between extension lines of the valley bottom line toward the seating surface is within a range of 30 to 120 °.   The distance between the cutting edge and the opening end of the concave portion on the cutting edge side is in a range of 1.5 to 3 mm in a direction perpendicular to the longitudinal direction. Item 3. The cutting insert according to Item 2.   In the end surfaces of the pair of cutting blade portions, the periphery of the opening of the concave portion on the seating surface side with respect to the clearance surface of the cutting blade is a flat surface extending in a direction perpendicular to the longitudinal direction. The cutting insert according to any one of claims 1 to 3.   The seating surface of the insert body or a side surface of the insert body that extends in the longitudinal direction intersecting the seating surface is formed with a recess recessed from the seating surface or the side surface. The cutting insert according to any one of claims 1 to 4.   The cutting insert according to any one of claims 1 to 5, wherein the seating surface is seated on an insert mounting seat formed on a tool main body, and one of the pair of cutting blade portions. An insert detachable cutting tool that is detachably mounted by projecting and having a convex portion that contacts the concave portion formed on the end surface of the other cutting edge portion of the cutting insert on the insert mounting seat. An insert detachable cutting tool characterized by being formed.

Images