JP5768516B2 - Cutting insert manufacturing method and cutting insert - Google Patents

Description

The present invention relates to a method for manufacturing a diamond-shaped cutting insert used for, for example, copying and spherical processing , and a cutting insert.

  2. Description of the Related Art Conventionally, there is known an edge-changing type cutting tool for turning a work material made of a metal material or the like. The cutting edge-replaceable cutting tool is made of a shaft-shaped steel material, etc., and is made of a hard material such as a cemented carbide alloy body and a hard insert such as a cemented carbide insert at its tip, and is attachable to and detachable from the insert mounting seat. A cutting insert to be mounted.

For example, as a cutting insert used for profiling and spherical machining, a diamond-shaped insert body as shown in Patent Document 1 below, a rake face facing the thickness direction of the insert body, and a peripheral wall of the insert body A flank face that intersects the rake face, a cutting edge that forms a cross ridge line between the rake face and the flank face of the insert body, and a mounting hole formed through the insert body. What you have is known.
In the cutting insert, the seating surface facing away from the rake face in the thickness direction of the insert body is in contact with the bottom surface of the insert mounting seat of the tool body, and the peripheral wall of the insert body is in contact with the inner wall surface of the insert mounting seat. In the abutted state, it is fixed to the tool body by a clamp screw or the like inserted through the mounting hole.

  In addition, this type of cutting insert is often used for medium cutting or finishing of a work material, and finishing surface accuracy is required. Therefore, the sharpness of the cutting edge is enhanced by polishing (grinding) the peripheral wall of the insert body.

JP 2007-75932 A

However, the conventional cutting insert has the following problems.
In the cutting insert of Patent Document 1, among the four corners of the rake face that forms a rhombus, the apex angle of an acute corner used for cutting is as small as about 25 °, and the shape of the insert body is a pair of rake faces on the rake face. It is long in the direction connecting sharp corners, and is short in the direction connecting a pair of obtuse corners. Corresponding to the shape of such a cutting insert, the shape of the insert mounting seat of the tool body is a concave V-shape whose inner wall surface is an acute angle when the bottom surface of the insert mounting seat is viewed from the front. ing.

  As described above, when the peripheral wall of the insert body is polished for the purpose of enhancing the sharpness of the cutting edge, the processing error in the direction connecting the obtuse corners (the short direction of the rake face) is slight. Also appears as a large processing error in the direction connecting the sharp corners (longitudinal direction of the rake face). Specifically, after polishing the peripheral wall of the insert body, if a processing error of about 5/100 mm, for example, occurs in the short direction of the rake face, the error in the longitudinal direction of the rake face is about 25/100 mm. As a result, the positional accuracy of the cutting insert relative to the insert mounting seat (particularly the positional accuracy in the longitudinal direction of the rake face) could not be ensured. Then, it becomes difficult to screw the clamp screw into the female screw hole of the insert mounting seat through the mounting hole of the cutting insert, or when the cutting insert is attached to the insert mounting seat, the peripheral wall of the insert body and the inner wall surface of the insert mounting seat In some cases, a gap was generated between the two, and the clamping rigidity of the cutting insert could not be ensured. Even if the dimensional accuracy of the outer shape is ensured after polishing the peripheral wall of the insert body, the same problem as described above occurs if the relative positional accuracy between the peripheral wall and the mounting hole cannot be ensured. It will be.

  On the other hand, it is conceivable to improve the sharpness of the cutting edge by polishing the rake face of the insert body instead of polishing the peripheral wall of the insert body. However, in general, a breaker for improving chip disposal is formed in the vicinity of the cutting edge of the rake face, which is not preferable.

The present invention has been made in view of such circumstances, can ensure the positional accuracy of the cutting insert relative to the insert mounting seat of the tool body, can be easily mounted of the cutting insert, can also ensure the clamp rigidity, and It aims at providing the manufacturing method of the cutting insert which can improve the sharpness of a cutting edge , and the cutting insert.

In order to achieve the above object, the present invention proposes the following means.
That is, the present invention is formed so as to correspond to the diamond plate-like insert body, the rake face facing the thickness direction of the insert body, and the acute corner of the rake face of the peripheral wall of the insert body, A cutting insert comprising: a flank that intersects the rake face; a cutting edge that forms a cross ridge line between the rake face and the flank of the insert body; and a mounting hole that is formed through the insert body. A method of manufacturing, wherein an apex angle of an acute angle portion of the rake face is set to 20 ° to 35 °, the insert body made of cemented carbide is sintered, and the rake face is formed on the insert body, The flank, the cutting edge and the mounting hole are integrally formed, and an insert restraint surface formed so as to reach the rake face is formed on a portion of the peripheral wall of the insert body other than the flank. The first flank that is connected to the cutting edge among the flank faces is ground to be a polished surface, and is disposed on the opposite side of the cutting edge across the first flank face. The second flank having a flank angle larger than the flank angle of the first flank is left as sintered skin.
Further, the cutting insert of the present invention includes a rhomboid insert body made of cemented carbide, a rake face facing the thickness direction of the insert body, and an acute corner portion of the rake face of the peripheral wall of the insert body. A flank that intersects the rake face, a cutting edge that forms a cross ridge line between the rake face and the flank of the insert body, and an attachment formed through the insert body. And the apex angle of the sharp corner of the rake face is 20 ° to 35 °, and the rake face, the flank face, the cutting edge and the mounting hole are integrated with the insert body. An insert restraint surface made of sintered skin is formed in a portion of the peripheral wall of the insert body other than the flank so as to reach the rake face, and the flank is adjacent to the cutting edge. Polishing Have a surface, said flank has a first flank connecting to the cutting edge, is arranged on the side opposite to the first flank interposed therebetween said cutting edge is larger than clearance angle of the first flank And a second flank having a flank angle, wherein the first flank is a polished surface, and the second flank is a sintered skin .

  In this cutting insert, the apex angle of the sharp corner of the rake face is as small as 20 ° to 35 °, and the shape of the insert body is long in the longitudinal direction of the rake face and in the short direction of the rake face. It is getting shorter. While having such a shape, an insert restraint surface made of sintered skin is formed on a portion of the peripheral wall of the insert body other than the flank, and the insert restraint surface is formed on the insert mounting seat of the tool body. By abutting against the inner wall surface, the positional accuracy of the cutting insert relative to the insert mounting seat is ensured.

  That is, according to the present invention, of the peripheral wall of the insert main body, the insert constraining surface is sintered (sintered skin) without polishing the portion (insert constraining surface) that contacts the inner wall surface of the insert mounting seat. Since it is used as it is, there is no possibility of causing a processing error due to polishing of the peripheral wall as in the prior art. That is, the dimensional accuracy of the outer shape of the peripheral wall of the insert main body is ensured, and the relative positional accuracy between the peripheral wall of the insert main body and the mounting hole is also ensured.

  Therefore, the position accuracy of the cutting insert relative to the insert mounting seat of the tool body can be secured, and when the cutting insert is mounted on the insert mounting seat, the clamp screw is screwed into the female screw hole of the insert mounting seat through the mounting hole of the cutting insert. The peripheral wall of the insert body of the mounted cutting insert and the inner wall surface of the insert mounting seat are reliably brought into contact with each other, and the clamping rigidity of the cutting insert is improved.

  In addition, since the insert restraint surface of the cutting insert is formed so as to reach the rake face on the peripheral wall of the insert body, the inner wall surface of the insert mounting seat contacts the portion near the rake face of the peripheral wall of the insert body. It can touch and can support a cutting insert stably. That is, a wide contact area between the inner wall surface of the insert mounting seat and the insert restraining surface of the insert body can be secured. In addition, since this contact area reaches a portion close to the rake face, the bottom face of the insert mounting seat and the seating surface of the insert body (the face of the insert body that faces the thickness direction of the rake face) Can secure a distance from the abutting portion of the surface facing the opposite side, and the mounting stability of the cutting insert is increased.

  In addition, while the clamping rigidity of the cutting insert is ensured as described above, the flank of the peripheral wall of the insert body is polished, that is, the portion adjacent to the cutting edge on the flank is the polishing surface. As a result, the cutting edge is formed into a sharp edge. Therefore, the cutting resistance of the cutting edge is reduced and the sharpness is enhanced, burrs and welding are suppressed, and the cloudiness and the stagnation of the processed surface are prevented. That is, a glossy surface is easily obtained as a processed surface (finished surface) of the work material, and the processed surface accuracy is improved.

  In addition, since the portion adjacent to the cutting edge of the flank is polished, for example, for the purpose of preventing burrs (burrs on manufacturing) of the cutting edge when the flank is sintered skin, Big honing is not necessary. That is, the cutting edge can be set in advance to a sharp edge or a fine honing shape before sintering, and polishing processing in the subsequent process is easy, and the sharpness is easily and sufficiently secured.

  According to such a cutting insert of the present invention, for example, in steel processing, cutting resistance can be kept small, burrs and welding can be prevented, and finished surface accuracy can be ensured. The cutting insert of the present invention is also suitable for processing difficult-to-cut materials such as titanium and stainless steel and non-ferrous metal processing such as aluminum.

The front Symbol flank has a first flank connecting to the cutting edge, the sides of the first flank and the cutting edge is arranged on the opposite side, greater clearance angle than the relief angle of the first flank and a second flank having a first flank is polished surface, the second flank, Ru sintered skin der.

Accordingly , the shape of the corner portion of the peripheral wall of the insert body corresponding to the sharp corner portion of the rake face is formed such that the second flank portion (and the seating surface side) is larger than the first flank portion. . Specifically, the second flank portion gradually recedes inwardly of the peripheral wall of the insert body (toward the center side of the rake face) as it is separated from the rake face along the thickness direction of the insert body. Formed as follows.

That is, in the cross section along the thickness direction of the insert main body, the second flank portion is disposed so as to recede sufficiently from the cutting edge portion. Therefore, other than the cutting edge of the cutting insert, also in the thickness direction of the insert main body. Interference between the part and the work material is prevented.
In addition, while the first flank that contributes to the sharpness of the cutting edge is used as a polished surface, the second flank having a portion that is formed as described above is used as a sintered skin, so that the polishing process is simple. And it can be done with high accuracy.
Further, in the cutting insert of the present invention, the second flank has a concave curve shape in a longitudinal sectional view along the thickness direction of the insert body, and the seating of the second flank in the thickness direction is performed. It is preferable that the edge part of the surface side is connected to the said insert restraint surface without a level | step difference.

According to the cutting insert manufacturing method and the cutting insert of the present invention, the positional accuracy of the cutting insert with respect to the insert mounting seat of the tool body can be secured, the cutting insert can be easily mounted, the clamp rigidity can be secured, and the cutting insert can be cut. The sharpness of the blade can be increased.

It is a perspective view which shows the blade-tip-exchange-type cutting tool equipped with the cutting insert which concerns on one Embodiment of this invention. It is a top view which shows the blade-tip-exchange-type cutting tool equipped with the cutting insert which concerns on one Embodiment of this invention. It is a side view which shows the blade-tip-exchange-type cutting tool equipped with the cutting insert which concerns on one Embodiment of this invention. It is a front view which shows the blade-tip-exchange-type cutting tool equipped with the cutting insert which concerns on one Embodiment of this invention. It is a perspective view which shows the cutting insert which concerns on one Embodiment of this invention. It is a top view which shows the cutting insert which concerns on one Embodiment of this invention. It is a side view which shows the cutting insert which concerns on one Embodiment of this invention. It is a bottom view which shows the cutting insert which concerns on one Embodiment of this invention. It is a front view which shows the cutting insert which concerns on one Embodiment of this invention. It is an enlarged view which shows the acute corner | angular part vicinity of the rake face in FIG. It is an enlarged view which shows the acute corner | angular part vicinity of the rake face in FIG. It is an enlarged view which shows the acute corner | angular part vicinity of the rake face in FIG. It is a figure which shows the AA cross section of FIG. It is a figure which shows the BB cross section of FIG. It is a figure which shows CC cross section of FIG.

Hereinafter, the cutting insert 1 which concerns on one Embodiment of this invention, and the blade-tip-exchange-type cutting tool 10 using the same are demonstrated with reference to drawings.
The cutting insert 1 and the cutting edge-exchangeable cutting tool 10 according to the present embodiment are for performing a turning process on a work material made of a metal material or the like, and are used for finishing cutting such as profiling and spherical processing and medium cutting, for example. .

  As shown in FIGS. 1 to 4, the blade-tip-exchange-type cutting tool 10 is made of a shaft-shaped steel material or the like, a tool body 11 having a concave insert mounting seat 12 formed at the tip thereof, a cemented carbide, or the like. And a diamond-shaped cutting insert 1 that is detachably mounted on the insert mounting seat 12.

  The tool body 11 has a rectangular parallelepiped shank portion 13 other than the tip portion along the extending direction. The cutting edge 10 has a shank portion 13 fixedly supported by a machine tool (not shown) in a state in which the cutting edge 6 of the cutting insert 1 attached to the tip of the tool body 11 protrudes toward the work material. Is done.

  In the top view of the tool main body 11 shown in FIG. 2, the width of the tip portion of the tool main body 11 (the length in the left-right direction in FIG. 2) is larger than the width of the shank portion 13. Specifically, the tip of the tool body 11 is formed to protrude from the shank portion 13 toward one side in the width direction (the right side in FIG. 2). Moreover, the width | variety of the front-end | tip part of the tool main body 11 is gradually narrowed toward the front end side (lower side in FIG. 2) along the extension direction of the tool main body 11. As shown in FIG. Specifically, the surface facing the other side in the width direction (the left side in FIG. 2) of the tip portion of the tool body 11 is gradually retreated toward one side in the width direction as it goes toward the tip side of the tool body 11. It is formed so as to be inclined.

  Further, in the side view of the tool main body 11 shown in FIG. 3, the end of the tool main body 11 at the base end side of the tool main body 11 is on the upper side (left and right direction in FIG. 3). ) Projecting toward the) is formed so as to extend along the width direction (see FIG. 2).

  Further, the insert mounting seat 12 is formed so as to sandwich a rhombus-shaped bottom surface 12A facing upward in the height direction and a triangular portion located on the base end side of the tool body 11 from the bottom surface 12A from the width direction, When viewed from the front side of the bottom surface 12A (in the top view shown in FIG. 2), it has an inner wall surface 12B having an acute concave V shape. While the cutting insert 1 is mounted on the insert mounting seat 12, the inner wall surface 12 </ b> B can be brought into contact with an insert restraining surface 19 (to be described later) of the cutting insert 1, while from the cutting edge 6 and the flank 5. It is formed so as to be separated.

  Further, a female screw hole 12C into which a clamp screw 15 for mounting the cutting insert 1 to the insert mounting seat 12 is screwed is opened on the bottom surface 12A. In FIG. 2, the insert mounting seat 12 is disposed at one end in the width direction at the tip of the tool body 11, and opens toward the upper side and the tip of the tool body 11 in the height direction. .

  In FIG. 3, the portion of the distal end portion of the tool body 11 that is located on the lower side in the height direction of the insert mounting seat 12 (the right side in FIG. 3) gradually moves toward the proximal end side of the tool body 11 as it goes downward. It is formed to be inclined so as to recede. Moreover, the part located in the lower side in the height direction of the insert mounting seat 12 in the distal end portion of the tool body 11 is formed so as to gradually narrow its width toward the distal end side of the tool body 11 (FIG. 4). See).

  Moreover, in the upper surface (surface which faces the upper direction of a height direction) of the front-end | tip part of the tool main body 11, the part located in the other side of the width direction of the insert mounting seat 12 extends in parallel with the female screw hole 12C. A female screw hole (not shown) is formed. A clamp piece 16 is disposed on the upper surface of the tip of the tool body 11 so as to cover the upper side of the female screw hole.

  In FIG. 2, the clamp piece 16 has a base end of the tool body 11 through a through hole 16 </ b> A having a diameter larger than the female screw hole and coaxial with the female screw hole, and a female screw hole 12 </ b> C in the bottom surface 12 </ b> A of the insert mounting seat 12. It is provided on the upper side of the portion located on the side, and includes a pressing portion 16B that can contact the cutting insert 1 from the upper side.

  A clamp screw 17 is inserted into the through hole 16 </ b> A of the clamp piece 16, and the clamp screw 17 is screwed into the female screw hole opened on the upper surface of the tip portion of the tool body 11. Thereby, the clamp piece 16 is detachably fixed to the upper surface of the tip end portion of the tool main body 11, and the pressing portion 16 </ b> B contacts the rake face 3 of the cutting insert 1 from the upper side in the height direction. It has become.

  As shown in FIGS. 5 to 15, the cutting insert 1 includes a rhombus-like insert body 2, a rake face 3 facing the thickness direction of the insert body 2, and a rake face of the peripheral wall of the insert body 2. A flank 5 that intersects with the rake face 3, a cutting edge 6 that forms a cross ridge line between the rake face 3 and the flank 5 of the insert body 2, and an insert And an attachment hole 7 formed so as to penetrate the main body 2 in the thickness direction.

As shown in FIG. 5 and FIG. 6, the rake face 3 has a rhombus shape and is formed on one face of both outer faces facing the thickness direction in the insert body 2. A pair of acute corners 4 and a pair of obtuse corners 18 are provided at the four corners of the rake face 3 so as to face each other with the center of the rake face (the part where the mounting hole 7 is opened) interposed therebetween. Is formed.
In the following description, the direction connecting the pair of sharp corners 4 (the left-right direction in FIG. 6) is referred to as the longitudinal direction of the rake face 3, and the direction connecting the pair of obtuse corners 18 (FIG. 6). The vertical direction in FIG. 3 is referred to as the short direction of the rake face 3.

  As shown in FIG. 8, among the outer surfaces facing the thickness direction in the insert body 2, the other surface facing the side opposite to the rake surface 3 is a rhombus-shaped seating surface having a smaller outer shape (area) than the rake surface 3. Nine.

  6 and 11, the portion corresponding to the acute corner portion 4 in the outer peripheral edge portion of the rake face 3 is more than the portion adjacent to the center side in the longitudinal direction of the rake face 3 of the sharp corner portion 4. The rake face 3 is formed so as to protrude outward in the surface direction. Further, by this, the cutting edge 6 formed so as to correspond to the sharp corner 4 of the rake face 3 out of the outer peripheral edge of the rake face 3 is located outside the rake face 3 in the surface direction from the adjacent portion. It protrudes toward. Further, when the rake face 3 is viewed from the front, the apex angle θ of the acute corner portion 4 of the rake face 3 is 20 ° to 35 °.

  7, 9, and 14, a portion of the rake face 3 other than the outer peripheral edge portion (a central portion of the rake face 3 that is a part away from the intersecting ridge line between the rake face 3 and the peripheral wall of the insert body 2) 3A is The outer peripheral edge protrudes in the thickness direction, and the pressing portion 16B of the clamp piece 16 comes into contact with the central portion 3A.

The mounting hole 7 is formed so as to open in the central portion 3 </ b> A of the rake face 3 and the seating surface 9. In the mounting hole 7, the inner diameter of the portion opened to the central portion 3 </ b> A of the rake face 3 is larger than the inner diameter of the portion opened to the seating surface 9.
Further, the cutting insert 1 has a rotationally symmetric shape around the central axis of the mounting hole 7. Specifically, the cutting insert 1 is formed in two-fold symmetry (180 ° symmetry) with respect to the central axis of the mounting hole 7.

  5 and 7 to 9, the portion of the peripheral wall of the insert body 2 other than the flank 5 is made of sintered skin (that is, the insert body 2 is not subjected to polishing or the like after being sintered). The insert restraint surface 19 is formed so as to reach the rake surface 3. Specifically, the insert restraining surface 19 is on the entire circumference of the peripheral wall of the insert body 2 except for the flank 5 portion disposed on the rake face 3 side in the thickness direction at both ends in the longitudinal direction of the rake face 3. It is formed over.

  Further, as shown in FIG. 9 and FIG. 14, the portion other than the portion corresponding to the flank 5 (the portion adjacent in the thickness direction of the flank 5) of the insert restraining surface 19 is on the peripheral wall of the insert body 2. It is formed over the entire length in the thickness direction. That is, the insert restraint surface 19 intersects the rake surface 3 at the end portion on the rake face 3 side along the thickness direction, and intersects the seating surface 9 at the end portion on the seating surface 9 side along the thickness direction. Yes. Further, the insert restraining surface 19 gradually recedes toward the inner surface of the peripheral wall of the insert main body 2 (toward the rake face 3 or the center side of the seating face 9) as it goes toward the seating face 9 along the thickness direction. It is formed so as to be inclined.

  In a state where the cutting insert 1 is mounted on the insert mounting seat 12 of the tool body 11, the inner wall surface 12B of the insert mounting seat 12 is brought into contact with the insert restraining surface 19, and the bottom surface of the insert mounting seat 12 is contacted with the seating surface 9. 12A contacts.

  10, 12, and 15, the flank 5 of the peripheral wall of the insert body 2 is formed so as to protrude from the insert restraining surface 19. As shown in FIG. 15, in the cross section perpendicular to the longitudinal direction of the rake face 3 of the insert body 2, the flank 5 gradually moves along the thickness direction of the peripheral wall of the insert body 2 as the distance from the cutting edge 6 increases. Inclined so as to recede inward (toward the center side of the rake face 3 or the seating face 9), so that a relief angle is given to the flank 5.

Further, the flank 5 is disposed on the opposite side of the first flank 21 from the first flank 21 connected to the cutting edge 6 and the cutting edge 6 with the first flank 21 interposed therebetween, and is larger than the clearance angle of the first flank 21. And a second flank face 22 having.
The first flank 21 is a polished surface, and the second flank 22 is a sintered skin. Specifically, in the flank 5, at least the first flank 21 adjacent to the cutting edge 6 is a polished polishing surface.

  Further, as shown in FIG. 11, a pair of breakers 8 are formed at acute corner portions 4 of the rake face 3 so as to form a V shape when the rake face 3 is viewed from the front. Yes. The breaker 8 has a groove shape and is formed so as to extend along the cutting edge 6 at the outer peripheral edge portion of the rake face 3. As shown in FIG. 15, the cross-section of the breaker 8 gradually extends linearly toward the seating surface 9 in the thickness direction from the cutting edge 6 toward the center side of the rake face 3, and then further on the rake face 3. It extends in the shape of a concave curve so that the direction is gradually changed toward the rake face 3 side in the thickness direction as it goes toward the center side of the plate.

  In the cutting insert 1 of the present embodiment described above, the apex angle θ of the sharp corner 4 of the rake face 3 is as small as 20 ° to 35 °, and the shape of the insert body 2 is the length of the rake face 3. Long in the direction and short in the short direction of the rake face 3. While having such a shape, an insert restraint surface 19 made of sintered skin is formed on a portion of the peripheral wall of the insert body 2 other than the flank 5, and the insert restraint surface 19 is formed by the tool body 11. The position accuracy of the cutting insert 1 with respect to the insert mounting seat 12 is ensured by contacting the inner wall surface 12B of the insert mounting seat 12.

  That is, according to the present embodiment, the insert restraining surface 19 is sintered without polishing the portion of the peripheral wall of the insert body 2 that contacts the inner wall surface 12B of the insert mounting seat 12 (insert restraining surface 19). Since it is used as it is (sintered skin), there is no risk of processing errors due to polishing of the peripheral wall as in the conventional case. That is, the dimensional accuracy of the outer shape of the peripheral wall of the insert main body 2 is ensured, and the relative positional accuracy between the peripheral wall of the insert main body 2 and the mounting hole 7 is also ensured.

  Therefore, the positional accuracy of the cutting insert 1 with respect to the insert mounting seat 12 of the tool body 11 can be secured, and when the cutting insert 1 is mounted on the insert mounting seat 12, the clamp screw 15 is inserted through the mounting hole 7 of the cutting insert 1. It is easy to screw into the female screw hole 12C of the seat 12 and is easy to mount, and the peripheral wall of the insert body 2 of the mounted cutting insert 1 and the inner wall surface 12B of the insert mounting seat 12 are reliably brought into contact with each other. The clamp rigidity of the cutting insert 1 is improved.

  Moreover, since the insert restraining surface 19 of the cutting insert 1 is formed so as to reach the rake face 3 on the peripheral wall of the insert body 2, the inner wall surface 12 B of the insert mounting seat 12 is raked out of the peripheral wall of the insert body 2. The cutting insert 1 can be stably supported by being brought into contact with a portion close to the surface 3. That is, a wide contact area between the inner wall surface 12B of the insert mounting seat 12 and the insert restraining surface 19 of the insert body 2 can be secured. In addition, since this contact area reaches a part close to the rake face 3, a distance between this part and the contact part of the bottom surface 12A of the insert mounting seat 12 and the seating surface 9 of the insert body 2 is secured. This increases the mounting stability of the cutting insert 1.

  Further, as described above, while the clamping rigidity of the cutting insert 1 is ensured, the first flank 21 of the peripheral wall of the insert body 2 is polished, that is, adjacent to the cutting edge 6 on the flank 5. The cutting edge 6 is formed to be a sharp edge by making the part to be polished a polishing surface. Accordingly, the cutting resistance of the cutting edge 6 is reduced and the sharpness is enhanced, burrs and welding are suppressed, and the processing surface is prevented from becoming clouded or wrinkled. That is, a glossy surface is easily obtained as a processed surface (finished surface) of the work material, and the processed surface accuracy is improved.

  Moreover, since the part (1st flank 21) adjacent to the cutting edge 6 of the flank 5 is grind | polished, the burr | flash (manufacturing burr | flash) of the cutting edge part when a flank is a sintered skin, for example is prevented. There is no need for big honing, etc. That is, the cutting edge 6 can be set in advance to a sharp edge or a fine honing shape before sintering, and polishing processing in the subsequent process is easy, and the sharpness is easily and sufficiently secured.

  According to such a cutting insert 1 of the present embodiment, for example, in steel processing, cutting resistance can be kept small, burrs and welding can be prevented, and finished surface accuracy can be ensured. Moreover, the cutting insert 1 of this embodiment is suitable for difficult-to-cut material processing such as titanium and stainless steel and non-ferrous metal processing such as aluminum.

  In addition, the flank 5 of the peripheral wall of the insert body 2 is formed so as to protrude from the insert restraint surface 19, so that the first flank 21 can be easily polished. It is possible to prevent the constraining surface 19 from being polished. Therefore, the accuracy of the polishing process of the first flank 21 is sufficiently ensured, the sharpness of the cutting edge 6 can be reliably increased, and the insert restraint surface 19 and the inner wall surface 12B of the insert mounting seat 12 The contact accuracy is ensured, and the mounting stability of the cutting insert 1 is improved.

  Furthermore, the part corresponding to the cutting edge 6 among the crossed ridgelines of the rake face 3 and the peripheral wall of the insert main body 2 is the other part (in this embodiment, the length of the rake face 3 relative to the cutting edge 6 part). The portion of the cutting insert 1 other than the cutting edge 6 interferes with the work material at the time of copying or the like. Is prevented. Therefore, according to this cutting insert 1, cutting with a large cutting depth is possible.

  Further, the flank 5 includes a first flank 21 connected to the cutting edge 6 and a second flank 22 having a flank angle larger than the flank angle of the first flank 21, Since the second flank 22 is a polished surface, it has the following effects. That is, as shown in FIGS. 12 and 13, the shape of the corner 20 on the peripheral wall of the insert body 2 corresponding to the acute corner 4 of the rake face 3 is the second flank 22 (and its seating surface 9). Side) is formed to be larger than the first flank 21 portion. Specifically, in the cross section shown in FIG. 13, the second flank 22 portion has a concave curve shape, and gradually increases as the insert body 2 moves away from the rake face 3 along the thickness direction of the insert body 2. It is formed so as to largely recede toward the inside of the peripheral wall (toward the center side of the rake face 3).

That is, in the cross section along the thickness direction of the insert main body 2, the second flank 22 portion and the seating surface 9 side portion are disposed sufficiently retracted from the cutting blade 6 portion. Also in the vertical direction, interference between the part other than the cutting edge 6 of the cutting insert 1 and the work material is prevented.
Moreover, since the 1st flank 21 which contributes to the sharpness of the cutting edge 6 is used as a grinding | polishing surface, since the 2nd flank 22 which has the site | part formed so that it may be scooped out as mentioned above is made into the sintered skin, it is grind | polished. Processing is easy and highly accurate.

  In addition, since the breaker 8 is formed in the cutting insert 1, the processability of the chips of the work material generated by cutting the cutting edge 6 is sufficiently enhanced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  In the embodiment described above, the mounting hole 7 of the cutting insert 1 is formed so as to penetrate the insert body 2 in the thickness direction, but the present invention is not limited to this. That is, the attachment hole 7 may be formed, for example, through the insert body 2 in the short direction of the rake face 3.

  Further, in the above-described embodiment, the flank 5 is formed so as to protrude from the insert restraining surface 19 in the peripheral wall of the insert main body 2, but is not limited thereto. That is, on the peripheral wall of the insert body 2, for example, the flank 5 and the insert restraint surface 19 may be formed flush with each other.

DESCRIPTION OF SYMBOLS 1 Cutting insert 2 Insert body 3 Rake face 4 Sharp corner of rake face 5 Relief face 6 Cutting edge 7 Mounting hole 19 Insert restraint surface 21 First flank 22 Second flank face Top of sharp corner of rake face Corner

Claims (3)

  A diamond-shaped insert body;
  A rake face facing the thickness direction of the insert body,
  A flank that is formed to correspond to an acute corner of the rake face of the peripheral wall of the insert body, and intersects the rake face;
  A cutting edge forming a cross ridge line between the rake face of the insert body and the flank face;
  A method of manufacturing a cutting insert comprising an attachment hole formed through the insert body,
  The apex angle of the sharp corner of the rake face is 20 ° to 35 °,
  Sintering the insert body made of cemented carbide, and integrally forming the rake face, the flank face, the cutting edge and the mounting hole in the insert body,
  Of the peripheral wall of the insert body, the insert restraint surface formed so as to reach the rake face in a portion other than the flank face remains as a sintered skin,
  Of the flank,
  Polishing the first flank face connected to the cutting edge into a polished surface;
  The second flank that is disposed on the opposite side of the cutting edge across the first flank and has a larger flank than the first flank is left as a sintered skin. A method for manufacturing a cutting insert. A diamond-shaped insert body made of cemented carbide ;
A rake face facing the thickness direction of the insert body,
A flank that is formed to correspond to an acute corner of the rake face of the peripheral wall of the insert body, and intersects the rake face;
A cutting edge forming a cross ridge line between the rake face of the insert body and the flank face;
An attachment hole formed through the insert body,
The apex angle of the sharp corner of the rake face is 20 ° to 35 °,
In the insert body, the rake face, the flank face, the cutting edge and the mounting hole are integrally formed,
Of the peripheral wall of the insert body, the portion other than the flank is formed so that an insert restraint surface made of sintered skin reaches the rake face,
The flank may have a polishing surface adjacent to the cutting edge,
The flank is
A first flank surface connected to the cutting edge;
A second flank disposed on the opposite side of the cutting edge across the first flank and having a flank greater than the flank of the first flank;
The cutting insert according to claim 1, wherein the first flank is a polished surface, and the second flank is a sintered skin.   The cutting insert according to claim 2,
  In a longitudinal sectional view along the thickness direction of the insert body,
  The second flank has a concave curve shape, and the end of the second flank on the seating surface side in the thickness direction is connected to the insert restraint without a step. Cutting insert.

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