JP6166148B2 - Cutting insert, cutting tool, and method of manufacturing cut workpiece - Google Patents

Description

  The present invention relates to a cutting insert used for cutting, a cutting tool, and a method for manufacturing a cut product.

  Conventionally, the cutting insert of patent document 1 is known as a cutting insert used for cutting of work materials, such as a metal member. In the cutting insert described in Patent Document 1, a main cutting edge that forms an intersecting ridge line between the side surfaces, a pair of sub cutting edges extending from the main cutting edge, a main cutting edge, and a pair of two side surfaces A rectangular rake face formed in a region surrounded by the secondary cutting edge and a seating face located behind the rake face are formed. By attaching one of the two side surfaces to the insert mounting seat of the tool body, the main cutting edge and the pair of sub cutting edges on the other of the two side surfaces can be used for cutting.

JP 2012-179667 A

  In the cutting insert described in Patent Document 1, the rake face has a quadrangular shape and the seating face is located behind the rake face. For this reason, the seating surface on one of the side surfaces is greatly separated from the position directly below the main cutting edge on the other side surface. When a large load is applied to the cutting insert as in heavy cutting, it may be difficult to sufficiently support this load on the seating surface.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a cutting insert that can stably perform cutting even when a large load is applied to the cutting insert.

  A cutting insert according to an aspect of the present invention includes a rectangular upper surface, a rectangular lower surface, and a front side surface, a rear side surface, a first lateral side surface, and the first side surface located between the upper surface and the lower surface. It has four side surfaces comprising a second lateral side surface located on the opposite side of the lateral side surface.

The upper surface, the first and auxiliary cutting edge formed at the intersection line portion between the front side surface, a first main cutting edge partially formed in the intersection line portion between said first lateral side surface, A first main corner cutting edge corresponding to a first curved portion located between an intersecting line portion between the upper surface and the front side surface and an intersecting line portion between the upper surface and the first lateral side surface; A first sub-corner cutting edge corresponding to a second curved portion located between the intersection line with the front side surface and the intersection line part between the upper surface and the second lateral side surface, and the first main cutting edge , A first breaker groove provided along the first main corner cutting edge, the first sub cutting edge, and the first sub corner cutting edge , and a flat surface located inside the first breaker groove A first abutment surface, and the first abutment surface extends to a region close to the front side surface at the intersection of the upper surface and the second lateral side surface. Mashimashi are, and are projected toward the first main corner cutting edge.

The lower surface has a second minor cutting edge formed at the intersection line portion between the front side surface, a second major cutting edge partially formed on the intersection line portion and the second lateral side, A second main corner cutting edge corresponding to a third curved portion located between an intersection line portion between the lower surface and the front side surface and an intersection line portion between the lower surface and the second lateral side surface; A second sub-corner cutting edge corresponding to a fourth curved portion located between the intersection line with the front side surface and the intersection line part between the lower surface and the first lateral side surface, the second main cutting edge , A second breaker groove provided along the second main corner cutting edge, the second sub- cutting edge and the second sub-corner cutting edge , and a flat located inside the second breaker groove A second abutment surface, and the second abutment surface extends to a region adjacent to the front side surface at the intersection of the lower surface and the first lateral side surface. Mashimashi are, and are projected toward the second main corner cutting edge.

  In the cutting insert of the above aspect, the second contact surface extends to a region close to the front side surface at the intersection of the lower surface and the first lateral side surface. Therefore, when cutting is performed using the first main cutting edge and the first sub cutting edge on the upper surface, the second contact surface serving as the seating surface for the holder is defined as the first main cutting edge and the first main cutting edge. 1 can be provided at a position close to the position immediately below the auxiliary cutting edge. In addition, when cutting is performed using the second main cutting edge and the second sub cutting edge on the lower surface, the first abutting surface serving as a seating surface to the holder is the second main cutting edge and the second main cutting edge. It can be provided at a position close to the position immediately below the second auxiliary cutting edge. Thereby, since a cutting insert can be stably held with a holder, even if it is a case where a big load is added like heavy cutting, it can cut stably.

It is a perspective view which shows the cutting insert of one Embodiment of this invention. It is a perspective view from the lower surface side of the cutting insert shown in FIG. It is a top view of the cutting insert shown in FIG. It is a bottom view of the cutting insert shown in FIG. It is a side view from the side of the 1st side of the cutting insert shown in FIG. It is a side view from the front side of the cutting insert shown in FIG. It is a perspective view which shows the cutting tool of one Embodiment of this invention. It is a disassembled perspective view of the cutting tool shown in FIG. It is a perspective view which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention. It is a perspective view which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention. It is a perspective view which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention.

  Hereinafter, a cutting insert 1 (hereinafter also simply referred to as an insert 1) according to an embodiment of the present invention will be described in detail with reference to the drawings. However, in the drawings referred to below, for convenience of explanation, among the constituent members of the embodiment, only the main members necessary for explaining the present invention are shown in a simplified manner. Therefore, the cutting insert of the present invention may include any component not shown in the drawings to which the present specification refers. Moreover, the dimension of the member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each member, etc. faithfully.

  As shown in FIGS. 1 to 6, the cutting insert 1 of the present embodiment includes a rectangular upper surface 3, a rectangular lower surface 5, and four side surfaces located between the upper surface 3 and the lower surface 5.

  The upper surface 3 and the lower surface 5 in this embodiment are each substantially parallelograms. Here, the term “substantially parallelogram” does not strictly require that the shape is a parallelogram. This means that the virtual quadrilateral formed by connecting the four corners of the upper surface 3 is a parallelogram.

  Since the upper surface 3 and the lower surface 5 are substantially parallelograms, four side surfaces are formed between the upper surface 3 and the lower surface 5. In the present embodiment, the four side surfaces are constituted by a front side surface 7, a rear side surface 9, a first lateral side surface 11, and a second lateral side surface 13 located on the opposite side of the first lateral side surface 11.

A through hole 15 is formed from the center of the first lateral surface 11 to the center of the second lateral surface 13. The penetration direction of the through hole 15, that is, the central axis X <b> 1 of the through hole 15 is orthogonal to the first lateral side surface 11 and the second lateral side surface 13. The center of the first lateral surface 11 can be a point where straight lines connecting corner portions located on the diagonal lines of the first lateral surface 11 intersect. Similarly, the center of the second lateral surface 13 can be a point where straight lines connecting corner portions located on the diagonal line of the second lateral surface 13 intersect. The through hole 15 is provided to insert a fixing screw when the insert 1 is fixed to the holder of the cutting tool with a screw.

  Examples of the material of the member constituting the insert 1 include cemented carbide or cermet. As the composition of the cemented carbide, for example, WC-Co produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering, and WC-Co obtained by adding titanium carbide (TiC) to WC-Co. There is WC-TiC-TaC-Co in which tantalum carbide (TaC) is added to TiC-Co or WC-TiC-Co. The cermet is a sintered composite material in which a metal is combined with a ceramic component, and specifically, a sintered composite material mainly composed of a titanium compound such as titanium carbide (TiC) or titanium nitride (TiN). Is mentioned.

The surface of the member constituting the insert 1 may be coated with a film using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the composition of the coating include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al ₂ O ₃ ).

  The upper surface 3 in the present embodiment has a first main cutting edge 17a, a first sub cutting edge 17b, a first breaker groove 19, and a first contact surface 21. The lower surface 5 in the present embodiment has a second main cutting edge 23a, a second sub cutting edge 23b, a second breaker groove 25, and a second contact surface 27.

  The first sub cutting edge 17 b on the upper surface 3 is formed at the intersection of the upper surface 3 and the front side surface 7. The first main cutting edge 17a is partially formed at the intersection of the upper surface 3 and the first lateral surface 11. One end of the first main cutting edge 17 a is continuous with the first sub cutting edge 17 b at the corner of the upper surface 3, and is formed from the first sub cutting edge 17 b toward the rear side surface 9. Yes.

  The second sub cutting edge 23 b on the lower surface 5 is formed at the intersection of the lower surface 5 and the front side surface 7. The second main cutting edge 23 a is partially formed at the intersection of the lower surface 5 and the second lateral side surface 13. One end of the second main cutting edge 23 a is continuous with the second sub cutting edge 23 b at the corner of the lower surface 5, and is formed from the second sub cutting edge 23 b toward the rear side surface 9. Yes.

  In the insert 1 of the present embodiment, the first main cutting edge 17a and the first sub cutting edge 17b (hereinafter, these cutting edges are collectively referred to as “first cutting edge 17”), or the second Cutting can be performed by using any one of the main cutting edge 23a and the second auxiliary cutting edge 23b (hereinafter, these cutting edges are collectively referred to as "second cutting edge 23"). For example, when the lower surface 5 side is used as a seating surface to the holder and the first cutting edge 17 is projected toward the work material, the first cutting edge 17 can be used for cutting. Further, when the second cutting edge 23 is protruded toward the work material by turning the insert 1 upside down and using the upper surface 3 as a seating surface to the holder, the second cutting edge 23 is cut. Can be used for processing.

  At this time, the intersecting line portion between the upper surface 3 and the lower surface 5 and the side surface is not a strict line shape due to the intersection of two surfaces. If the intersection line is sharp at an acute angle, the durability of the cutting edge is reduced. For this reason, a portion where the upper surface 3 and the lower surface 5 intersect with the side surface may be subjected to a so-called honing process in which a slightly curved surface is formed.

A first breaker groove 19 is formed in a region along the first cutting edge 17 on the upper surface 3. The 1st breaker groove | channel 19 is a surface used as the main body which controls a chip at the time of cutting, and a chip passes on this surface. The chip is curved by the first breaker groove 19 having a groove shape. For this reason, when cutting is performed using the first cutting edge 17, it is possible to prevent the chips from being excessively straightened, and thus the chip dischargeability is improved.

  The first breaker groove 19 need not be directly connected to the first main cutting edge 17a and the first sub cutting edge 17b. For example, a land surface (not shown) may be formed along the first cutting edge 17 between the first cutting edge 17 and the first breaker groove 19. The land surface is an inclination angle (rake angle) at a portion close to a cutting edge (corresponding to the first cutting edge 17 in the above) in the breaker groove (corresponding to the first breaker groove 19 in the above). It is a band-like region having a smaller inclination angle. By having such a land surface, the strength of the cutting edge can be increased.

  In this case, the inclination angle means an angle formed by a surface perpendicular to the virtual line and a target surface in a cross section including a virtual line passing through the center of the upper surface 3 and the center of the lower surface 5. The width of the land surface is appropriately set depending on the cutting conditions, but is set in a range of, for example, 1 mm or less.

  A second breaker groove 25 is formed in a region along the second cutting edge 23 on the lower surface 5. Similar to the first breaker groove 19, the second breaker groove 25 is a surface serving as a main body for controlling chips during cutting. The chip is curved by the second breaker groove 25 having a groove shape. For this reason, when cutting is performed using the second cutting edge 23, it is possible to prevent the chips from being excessively straightened, so that the chip dischargeability is improved. Similarly to the upper surface 3, a land surface may be formed along the second cutting edge 23 between the second cutting edge 23 and the second breaker groove 25.

  A flat first contact surface 21 is formed inside the first breaker groove 19. The first contact surface 21 functions as a seating surface for the holder when the insert 1 of the present embodiment is turned upside down and the second cutting edge 23 on the lower surface 5 is used for cutting. In addition, a flat second contact surface 27 is formed inside the second breaker groove 25. The second contact surface 27 functions as a seating surface for the holder when the first cutting edge 17 on the upper surface 3 is used for cutting.

  In the insert 1 of this embodiment, the first breaker surface is not formed in an annular shape along the entire outer periphery of the upper surface 3. Specifically, the first contact surface 21 extends to a region 21 a that is close to the front side surface 7 at the intersection of the upper surface 3 and the second lateral side surface 13. Further, the second breaker surface is not formed in an annular shape along the entire outer periphery of the lower surface 5. Specifically, the second contact surface 27 extends to a region 27 a close to the front side surface 7 at the intersection of the lower surface 5 and the first lateral side surface 11.

  When cutting is performed using the first cutting edge 17, the corner is directed toward the work material around the corner where the first main cutting edge 17a and the first auxiliary cutting edge 17b are continuous. Cutting is performed using the first main cutting edge 17a, the corners, and the first sub cutting edge 17b in such a positional relationship as to protrude most. Therefore, it is not necessary to form a cutting edge in a region continuous with the first sub cutting edge 17b at the intersection of the upper surface 3 and the second lateral side surface 13, and this region is not used for cutting.

In the insert 1 of the present embodiment, the first abutting surface 21 is located in a region 21 a close to the front side surface 7 in the intersecting portion between the upper surface 3 and the second lateral side surface 13, which is a region not used for this cutting process. Is extended. In the insert 1 of the present embodiment, a first breaker groove 19 is formed in a region along the first cutting edge 17. For this reason, the first contact surface 21 does not reach the front side surface 7 at the intersection of the upper surface 3 and the second lateral side surface 13, and is spaced by about the width of the first breaker groove 19. And close to the front side surface 7. That is, the region close to the front side surface 7 means a region approaching the front side surface 7 up to an interval about the width of the first breaker groove 19.

  The extending area 21a in the first contact surface 21 is located immediately above the second main cutting edge 23a. Therefore, when the insert 1 is turned upside down and the second cutting blade 23 is used for cutting, the first abutment surface 21 serving as a seating surface for the holder is replaced with the second main cutting edge 23a and It can be provided at a position near the second sub cutting edge 23b. Since the second main cutting edge 23a can be stably supported by the extending region 21a in the first contact surface 21, the insert 1 can be stably held by the holder. Therefore, even when a large load is applied as in heavy cutting, cutting can be performed stably.

  Further, when cutting is performed using the second cutting edge 23, the corner portion is cut around a corner portion where the second main cutting edge 23a and the second auxiliary cutting edge 23b are continuous. Cutting is performed using the second main cutting edge 23a, the corner portion, and the second auxiliary cutting edge 23b in such a positional relationship as to protrude most toward the material. For this reason, it is not necessary to form a cutting edge in a region continuous with the second sub cutting edge 23b at the intersection of the lower surface 5 and the first lateral surface 11, and this region is not used for cutting.

  In the insert 1 of the present embodiment, the second abutting surface 27 is in a region 27 a close to the front side surface 7 at the intersection of the lower surface 5 and the first lateral side surface 11, which is a region not used for this cutting process. Is extended. In the insert 1 of the present embodiment, a second breaker groove 25 is formed in a region along the second cutting edge 23. For this reason, the second contact surface 27 does not reach the front side surface 7 at the intersection of the upper surface 3 and the first lateral surface 11, and is spaced about the width of the second breaker groove 25. And close to the front side surface 7.

  The extending region 27a in the second contact surface 27 is located immediately below the first main cutting edge 17a. Therefore, in the case of performing cutting using the first cutting edge 17, the second contact surface 27 serving as a seating surface for the holder is used as the first main cutting edge 17a and the first sub cutting edge 17b. It can be provided at a position close to directly below. Since the first main cutting edge 17a can be stably supported by the extended region 27a in the second contact surface 27, the insert 1 can be stably held by the holder.

  The first width shown in the direction parallel to the first lateral surface 11 on the upper surface 3 and the lower surface 5 can be, for example, about 15 to 25 mm. Moreover, the 2nd width | variety shown by the direction perpendicular | vertical to the 1st side surface 11 in the upper surface 3 and the lower surface 5 can be about 3-10 mm, for example. Moreover, the height of the side surface shown by the space | interval of the upper surface 3 and the lower surface 5 can be about 10-20 mm, for example.

  The insert 1 of the present embodiment has a configuration in which the height of the side surface is larger than the second width of the upper surface 3. Since the distance from the lower surface 5 to the first auxiliary cutting edge 17b is long as described above, the first auxiliary cutting edge 1 has a smaller height on the side surface than the so-called flat plate-shaped insert 1 during cutting. When a load is applied to the cutting edge 17b, it becomes easy to rotate around the through hole 15.

  However, in the insert 1 of this embodiment, the second contact surface 27 on the lower surface 5 extends to a region 27 a close to the front side surface 7 at the intersection of the lower surface 5 and the first lateral surface 11. ing. Therefore, it is possible to increase the area of the contact surface in the region of the second contact surface 27 near the first sub cutting edge 17b. Thereby, even when a load is applied to the first sub cutting edge 17b, the insert 1 can be stably fixed.

  As already shown, in the insert 1 of this embodiment, the upper surface 3 and the lower surface 5 are each substantially parallelograms. Angles formed by two imaginary lines extending from the corner located at the intersection of the first main cutting edge 17a and the first sub cutting edge 17b toward the two corners adjacent to the corner. However, it is 64-89 degrees.

  Further, two imaginary lines extending from the corner located at the intersection of the second main cutting edge 23a and the second sub cutting edge 23b toward the two corners adjacent to the corner, respectively. Similarly, the formed angle is 64 to 89 °. Therefore, when viewed from above, the first auxiliary cutting edge 17b and the second auxiliary cutting edge 23b are positioned so as to intersect each other.

  Moreover, in the insert 1 of this embodiment, the upper surface 3 is not a strict parallelogram, and the center of the intersection line with the first lateral side surface 11 and the second lateral side surface 13 is 4 inward from both ends. The shape is recessed by about °. Therefore, the angle formed by the first main cutting edge 17a and the first sub cutting edge 17b on the upper surface 3 is 75 to 85 °.

  Further, the upper surface 3 in the present embodiment further includes a third main cutting edge 29a, a third sub cutting edge 29b, and a third breaker groove 31. The third auxiliary cutting edge 29 b on the upper surface 3 is formed at the intersection of the upper surface 3 and the rear side surface 9. The third main cutting edge 29 a is partially formed at the intersection of the upper surface 3 and the second lateral side surface 13. One end of the third main cutting edge 29 a is continuous with the third sub cutting edge 29 b at the corner of the upper surface 3, and is formed from the third sub cutting edge 29 b toward the front side surface 7. Yes.

  In the insert 1 of the present embodiment, the third main cutting edge 29a and the third auxiliary cutting edge 29b (hereinafter, these cutting edges are collectively referred to as “third cutting edge 29”) are the first cutting edges. It can be used instead of the blade 17 and the second cutting blade 23. Specifically, the third cutting blade 29 is set at the position of the first cutting blade 17 by rotating the upper surface 3 by 180 ° about the center of the upper surface 3. Can be used instead of the first cutting edge 17.

  A third breaker groove 31 is formed in a region along the third cutting edge 29 on the upper surface 3. The third breaker groove 31 is a main surface that performs cutting in the cutting tool, and has the same effect as the first breaker groove 19. In the insert 1 of the present embodiment, the first contact surface 21 extends toward the third cutting edge 29. Therefore, the first contact surface 21 is also formed inside the third breaker groove 31.

  The first abutment surface 21 extends to a region 21 b close to the rear side surface 9 at the intersection of the upper surface 3 and the first lateral side surface 11. Therefore, like the first breaker groove 19, the third breaker groove 31 is not formed in an annular shape along the entire outer periphery of the upper surface 3.

  The first abutment surface 21 extends to a region 21 b close to the rear side surface 9 at the intersection of the upper surface 3 and the first lateral side surface 11. Therefore, the first main cutting edge 17a is partially formed not on the entire intersection line between the upper surface 3 and the first lateral surface 11 but on a part of the intersection line near the front side surface 7. ing. Specifically, in the intersection line portion between the upper surface 3 and the first lateral side surface 11, the first main portion extends from the end portion on the front side surface 7 side of the intersection line portion toward the end portion on the rear side surface 9 side. A cutting edge 17a is partially formed. Further, in the intersecting portion between the upper surface 3 and the first lateral surface 11, a portion where the first contact surface 21 extends is located closer to the rear side surface 9 than the first main cutting edge 17 a. .

  At this time, the length L1 of the first auxiliary cutting edge 17b along the intersection line is the first contact surface at the intersection line between the upper surface 3 of the insert 1 and the first lateral surface 11 of the present embodiment. 21 is longer than the length L2 of the region 21b. Therefore, when cutting using the first cutting edge 17, the length of the first auxiliary cutting edge 17b can be sufficiently secured. In addition, although the length L2 of the first contact surface 21 is relatively shorter than the length L1 of the first sub cutting edge 17b, the upper surface 3 on the rear side surface 9 side than the first sub cutting edge 17b. And extends to the intersection of the first lateral surface 11 and the first lateral surface 11. Therefore, even when cutting is performed using the fourth cutting edge 33, the insert 1 can be stably fixed on the first contact surface 21.

  Further, the first contact surface 21 extends to a region 21 a close to the front side surface 7 at the intersection of the upper surface 3 and the second lateral side surface 13. For this reason, the third main cutting edge 29a is partially formed not on the entire intersection line between the upper surface 3 and the second lateral side surface 13 but on a part of the intersection line near the rear side surface 9. ing. Specifically, the third main main portion from the end portion on the rear side surface 9 side to the end portion on the front side surface 7 side in the intersection line portion between the upper surface 3 and the second lateral side surface 13. A cutting edge 29a is partially formed. In addition, a portion where the first contact surface 21 extends is located on the front side surface 7 side of the third main cutting edge 29a at the intersection of the upper surface 3 and the second lateral surface 13. .

  In addition, the lower surface 5 in the present embodiment further includes a fourth main cutting edge 33a, a fourth main cutting edge 33a, and a fourth breaker groove 35. The fourth auxiliary cutting edge 33 b on the upper surface 3 is formed at the intersection of the lower surface 5 and the rear side surface 9. The fourth main cutting edge 33 a is partially formed at the intersection of the lower surface 5 and the first lateral surface 11. One end of the fourth main cutting edge 33 a is continuous with the fourth sub cutting edge 33 b at the corner of the lower surface 5, and is formed from the fourth sub cutting edge 33 b toward the front side surface 7. Yes.

  In the insert 1 of the present embodiment, the fourth main cutting edge 33a and the fourth auxiliary cutting edge 33b (hereinafter, these cutting edges are collectively referred to as “fourth cutting edge 33”) are the first cutting edges. It can be used in place of the blade 17, the second cutting blade 23 and the third cutting blade 29. Specifically, the fourth cutting edge 33 is set at the position of the second cutting edge 23 by rotating the lower face 5 180 degrees about the center of the lower face 5. Can be used instead of the second cutting edge 23.

  A fourth breaker groove 35 is formed in a region along the fourth cutting edge 33 on the upper surface 3. The fourth breaker groove 35 is a main surface that performs cutting in the cutting tool, and has the same effect as the first breaker groove 19. In the insert 1 of this embodiment, the second contact surface 27 extends toward the fourth cutting edge 33. Therefore, the second contact surface 27 is also formed inside the fourth breaker groove 35.

  The second contact surface 27 extends to a region 27 b close to the rear side surface 9 at the intersection of the lower surface 5 and the second lateral side surface 13. Therefore, like the second breaker groove 25, the fourth breaker groove 35 is not formed in an annular shape along the entire outer periphery of the lower surface 5.

  Since the second contact surface 27 extends to the region 27b close to the rear side surface 9 at the intersection of the lower surface 5 and the second lateral side surface 13, the second main cutting edge 23a is It is not part of the entire intersection line between the lower surface 5 and the second lateral side surface 13, but is partially formed on a part of the intersection line near the front side surface 7. Specifically, the second main cutting edge 23 a is a region in which the second contact surface 27 extends from the end portion on the front side surface 7 side at the intersection of the lower surface 5 and the second lateral surface 13. It is partially formed up to 27b.

In addition, since the second contact surface 27 extends to the region 27b close to the front side surface 7 at the intersection of the lower surface 5 and the first lateral surface 11, the fourth main cutting edge 33a. Is formed not in the whole intersection line portion between the lower surface 5 and the first lateral side surface 11 but in a part of the intersection line portion near the rear side surface 9. Specifically, the fourth main cutting edge 33a includes the lower surface 5 and the first lateral side surface 11.
To the region 27a where the second abutment surface 27 extends from the end portion on the rear side surface 9 side in the intersecting line portion.

  Thus, since the insert 1 of this embodiment has the four cutting edge regions of the first cutting edge 17, the second cutting edge 23, the third cutting edge 29, and the fourth cutting edge 33. The structure is excellent in economic efficiency.

  As already shown, in the insert 1 of the present embodiment, the shape of the center of the intersection line between the upper surface 3 and the first lateral side surface 11 and the second lateral side surface 13 is recessed inward from the both end portions, respectively. It has become. Furthermore, in the insert 1 of the present embodiment, the width of the first contact surface 21 in the direction orthogonal to the direction gradually increases from the central portion in the direction from the rear side surface 9 to the front side surface 7 toward the front side surface 7. It has a region that grows. Specifically, the width W1 in the region near the front side surface 7 in the first contact surface 21 is larger than the width W2 in the central portion of the first contact surface 21.

  With such a configuration, it is possible to easily ensure the width in the direction perpendicular to the first sub cutting edge 17b in the region along the first sub cutting edge 17b in the first breaker groove 19. it can. Therefore, the chips generated in the first sub cutting edge 17b can be stably processed. In addition, when cutting is performed using the second cutting edge 23, a larger load is applied to a region closer to the front side surface 7 on the first contact surface 21 than to a central portion on the first contact surface 21. easy.

  However, when the first contact surface 21 has the above-described configuration, the area of the first contact surface 21 where a relatively large load is easily applied can be increased. Therefore, the insert 1 can be stably held when the second cutting edge 23 is used for cutting.

  The top surface 3 of the insert 1 of the present embodiment is a first curved portion where the boundary between the intersecting line portion with the front side surface 7 and the intersecting line portion with the first lateral side surface 11 is a curved shape when viewed from above. It is the composition which becomes. Further, when viewed from above, the boundary between the intersecting line portion with the front side surface 7 and the intersecting line portion with the second lateral side surface 13 is a second curved portion having a curved shape. And the curvature radius of the 2nd curve part is larger than the curvature radius of the 1st curve part.

<Cutting tools>
Next, a cutting tool 101 according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 7 and 8, the cutting tool 101 of the present embodiment includes a holder 103 having an insert pocket 105 on the tip side and an insert pocket 107 so that one of a plurality of cutting blades protrudes from the tip of the holder 103. The cutting insert 1 is mounted.

  The holder 103 has an elongated bar shape. One insert pocket 105 is provided on the tip side of the holder 103. The insert pocket 105 is a part to which the cutting insert 1 is mounted, and is open to the front end surface of the holder 103. At this time, since the insert pocket 105 is also open to the side surface of the holder 103, the cutting insert 1 can be easily mounted. Specifically, the insert pocket 105 has a seating surface 105 a parallel to the lower surface of the holder 103 and a constraining side surface 105 b orthogonal to the seating surface 109.

The insert 1 is mounted in the insert pocket 105. The insert 1 is mounted so that one of the plurality of cutting blades protrudes toward the distal end side of the holder 103. Specifically, in the cutting tool 101 of the present embodiment, the first cutting blade among the first cutting blade 17, the second cutting blade 23, the third cutting blade 29, and the fourth cutting blade 33. 17 is mounted on the holder 103 so as to protrude outward from the tip of the holder 103. That is, with this configuration, the first cutting edge 13 is constrained to a position that protrudes most from the outer peripheral surface of the holder 103 during cutting. At this time, the insert 1 is mounted on the holder 103 by bringing the second contact surface 27 into contact with the seating surface 105a and bringing the second lateral surface 13 into contact with the restraining side surface 105b.

  In this embodiment, although the case where the 1st cutting blade 17 is used for cutting is illustrated, it is not restricted to this in particular. For example, when the second cutting edge 23 configured by the second main cutting edge 23 a and the second sub-cutting edge 23 b is used for cutting, the second cutting edge 23 protrudes from the outer peripheral surface of the holder 103. It is attached to the holder 103 so as to. In this case, the insert 1 may be mounted on the holder 103 by bringing the first abutting surface 21 into contact with the seating surface and bringing the first lateral side surface 11 into contact with the restraining side surface.

  In the present embodiment, the insert 1 is attached to the holder 103 by a fixing screw 107. That is, by inserting the fixing screw 107 into the through hole 15 of the insert 1 and inserting the tip of the fixing screw 107 into the screw hole 109 formed in the insert pocket 105 and screwing the screw portions together, The holder 103 is attached.

  As the holder 103, steel, cast iron, or the like can be used. In particular, it is preferable to use steel having high toughness among these members.

<Manufacturing method of cut product>
Next, the manufacturing method of the cut workpiece of one Embodiment of this invention is demonstrated using drawing.

The cut workpiece is produced by cutting the work material 201. The manufacturing method of the cut workpiece in the present embodiment includes the following steps. That is,
(1) rotating the work material 201;
(2) a step of bringing the first cutting edge 17 in the cutting tool 101 represented by the above embodiment into contact with the rotating work material 201;
(3) a step of separating the cutting tool 101 from the work material 201;
It has.

  More specifically, first, as shown in FIG. 9, the work material 201 is rotated around the axis Y, and the cutting tool 101 is relatively moved closer to the work material 201. Next, as shown in FIG. 10, the first cutting edge 17 of the cutting tool 101 is brought into contact with the work material 201 to cut the work material 201. Then, as shown in FIG. 11, the cutting tool 101 is relatively moved away from the work material 201.

  In the present embodiment, the cutting tool 101 is brought close to the work material 201 while the axis Y is fixed and the work material 201 is rotated. In FIG. 10, the work material 201 is cut by bringing the first cutting edge 17 of the cutting insert 1 into contact with the rotating work material 201. In FIG. 11, the cutting tool 101 is moved away while the work material 201 is rotated.

  In the cutting in the manufacturing method of the present embodiment, the cutting tool 101 is brought into contact with the work material 201 by moving the cutting tool 101 in each step, or the cutting tool 101 is separated from the work material 201. However, as a matter of course, it is not limited to such a form.

  For example, the work material 201 may be brought close to the cutting tool 101 in the step (1). Similarly, in the step (3), the work material 201 may be moved away from the cutting tool 101. In the case of continuing the cutting process, the state in which the workpiece 201 is rotated and the first cutting blade 17 in the cutting insert 1 is brought into contact with a different portion of the workpiece 201 may be repeated.

  Note that typical examples of the material of the work material 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metal.

1. Cutting insert (insert)
DESCRIPTION OF SYMBOLS 3 ... Upper surface 5 ... Lower surface 7 ... Front side surface 9 ... Rear side surface 11 ... 1st side surface 13 ... 2nd side surface 15 ... Through-hole 17 ... 1st cutting edge 17a ... 1st main cutting edge 17b ... 1st auxiliary cutting edge 19 ... 1st breaker groove 21 ... 1st contact surface 23 ... 2nd Second cutting edge 23a ... second main cutting edge 23b ... second auxiliary cutting edge 25 ... second breaker groove 27 ... second contact surface 29 ... third cutting edge Blade 29a ... Third main cutting blade 29b ... Third sub-cutting blade 31 ... Third breaker groove 33 ... Fourth cutting blade 33a ... Fourth main cutting blade 33b ... 4th sub cutting edge 35 ... 4th breaker groove 1 ... area 101 ... cutting tool 103 ... holder 105 ... insert pocket 107 ... screw 107a ... seating Surface 107b ... restraint Surface 109 ... screw hole 201 ... workpiece

Claims (7)

A rectangular upper surface, a rectangular lower surface, and a front side surface, a rear side surface, a first lateral side surface, and a second side located opposite to the first lateral side surface, located between the upper surface and the lower surface. A cutting insert with four side surfaces consisting of side surfaces,
The upper surface, the first and auxiliary cutting edge formed at the intersection line portion between the front side surface, a first main cutting edge partially formed in the intersection line portion between said first lateral side surface, A first main corner cutting edge corresponding to a first curved portion located between an intersecting line portion between the upper surface and the front side surface and an intersecting line portion between the upper surface and the first lateral side surface; A first sub-corner cutting edge corresponding to a second curved portion located between the intersection line with the front side surface and the intersection line part between the upper surface and the second lateral side surface, and the first main cutting edge , A first breaker groove provided along the first main corner cutting edge, the first sub cutting edge, and the first sub corner cutting edge , and a flat surface located inside the first breaker groove A first abutment surface,
The first abutment surface extends to a region close to the front side surface at the intersection of the upper surface and the second lateral side surface, and the first main corner cutting edge Protruding towards the
The lower surface has a second minor cutting edge formed at the intersection line portion between the front side surface, a second major cutting edge partially formed on the intersection line portion and the second lateral side, A second main corner cutting edge corresponding to a third curved portion located between an intersection line portion between the lower surface and the front side surface and an intersection line portion between the lower surface and the second lateral side surface; A second sub-corner cutting edge corresponding to a fourth curved portion located between the intersection line with the front side surface and the intersection line part between the lower surface and the first lateral side surface, the second main cutting edge , A second breaker groove provided along the second main corner cutting edge, the second sub-cutting edge and the second sub-corner cutting edge , and a flat located inside the second breaker groove A second abutment surface,
The second abutment surface extends to a region close to the front side surface at the intersection of the lower surface and the first lateral side surface , and the second main corner cutting edge A cutting insert characterized by protruding toward the surface. The upper surface has a third auxiliary cutting edge formed at the intersection line with the rear side surface, a third main cutting edge partially formed at the intersection line portion with the second lateral side surface, A third main corner cutting edge corresponding to a fifth curved portion located between an intersection line portion between the upper surface and the rear side surface and an intersection line portion between the upper surface and the second lateral side surface; A third sub-corner cutting edge corresponding to a sixth curve portion located between the intersection line with the rear side surface and the intersection line portion between the upper surface and the first lateral side surface, the third main cutting edge , A third breaker groove provided along the third main corner cutting edge, the third sub cutting edge, and the third sub corner cutting edge ;
The first abutting surface extends to a region close to the rear side surface at the intersection line between the upper surface and the first lateral side surface, and the third main corner cutting edge Protruding towards the
The lower surface includes a fourth auxiliary cutting edge formed at the intersection line with the rear side surface, a fourth main cutting edge partially formed at the intersection line portion with the first lateral side surface, A fourth main corner cutting edge corresponding to a seventh curve portion located between an intersection line portion between the lower surface and the rear side surface and an intersection line portion between the lower surface and the first lateral side surface; A fourth sub-corner cutting edge corresponding to an eighth curved portion located between the intersection line with the rear side surface and the intersection line portion between the lower surface and the second lateral side surface, and the fourth main cutting edge , A fourth breaker groove provided along the fourth main corner cutting edge, the fourth sub cutting edge, and the fourth sub corner cutting edge , and the second contact surface is extends up to the region close to the rear side of the intersection line portion between the lower surface and the second lateral side and suited to the fourth main corner cutting edge Cutting insert according to claim 1, characterized in that protrudes Te.   A length of the first main cutting edge along the intersection line between the upper surface and the first lateral side surface is longer than that of the first contact surface. Item 3. The cutting insert according to Item 2.   The first contact surface has a region in which a width in a direction perpendicular to the direction gradually increases from a central portion in a direction from the rear side surface toward the front side surface toward the front side surface. The cutting insert according to claim 1, wherein the cutting insert is characterized. When viewed from above, the cutting insert according to claim 1, before Symbol radius of curvature of the second curved portion, being greater than the radius of curvature of the first curved portion. A holder having an insert pocket on the tip side;
The cutting tool provided with the cutting insert according to any one of claims 1 to 5, which is mounted on the insert pocket so that the first main cutting edge protrudes from a tip of the holder. A step of rotating the work material;
A method for manufacturing a cut product, comprising: a step of bringing the main cutting edge of the cutting tool according to claim 1 into contact with the rotating work material; and a step of separating the cutting tool from the work material.

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