JP6430796B2 - CUTTING TOOL AND PROCESS FOR PRODUCING CUT WORK - Google Patents

Description

  The present embodiment relates to a cutting tool and a method for manufacturing a cut workpiece.

  As a cutting tool used for a cutting process such as a milling process for a work material such as a metal, cutting tools described in Patent Documents 1 and 2 are known. The cutting tool described in Patent Literature 1 includes a plurality of cutting inserts (cutting inserts) and a cylindrical shape (holder) to which the cutting inserts are attached. The cutting edges of the plurality of cutting inserts define a stepped continuous uninterrupted cutting line.

  The cutting tool described in Patent Document 2 has a square plate-shaped first throw-away tip and second throw-away tip. The first throw-away tip extends from the distal end side to the proximal direction on the outer peripheral surface of the cutter body, and the second throw-away tip is attached from the outer peripheral side on the distal end surface of the cutter body. Attached to the center in the radial direction.

JP-A-9-248710 JP-A-8-39324

  In the cutting tools described in Patent Documents 1 and 2, the radial rakes of a plurality of cutting inserts attached to the holder are constant. However, in the plurality of cutting inserts, the position of the cutting blade used and the width and thickness of the resulting chips are different from each other. Therefore, the load applied to the plurality of cutting inserts may vary.

  The present aspect has been made in view of the above-described problems, and provides a cutting tool capable of stably performing a cutting process while suppressing variations in load applied to a plurality of cutting inserts.

The cutting tool based on one aspect has a 1st insert pocket and the 2nd insert pocket located in the back end side rather than the 1st insert pocket, and it goes from the tip side toward the back end side along the axis of rotation. A first extending insert attached to the first insert pocket and partially protruding from a tip end surface and an outer peripheral surface of the holder, and a second insert pocket attached to the first insert pocket. A second cutting insert partially protruding from the outer peripheral surface, wherein the axial rake of the first cutting insert is larger than the axial rake of the second cutting insert . The first cutting insert has a first outer peripheral cutting edge located on the outer peripheral surface side of the holder, and a first outer peripheral rake face provided along the first outer peripheral cutting edge, When viewed from the front in the rotational direction around the rotation axis, the first outer peripheral rake face has a width that decreases as the distance from the tip end face of the holder increases. Further, the second cutting insert has a second outer peripheral cutting edge located on the outer peripheral surface side of the holder and a second outer peripheral rake face provided along the second outer peripheral cutting edge. The second outer rake face is a first region whose width becomes wider as the distance from the front end face of the holder increases when viewed from the front in the rotation direction around the rotation axis, And a second region that is located on the rear end side of the first region and decreases in width as it moves away from the tip surface of the holder .

  While the 2nd cutting insert has protruded partially from the outer peripheral surface of a holder, the 1st cutting insert has protruded partially from the front end surface and outer peripheral surface of a holder. Therefore, a load is applied to the second cutting insert mainly from the outer peripheral surface side of the holder, whereas a load is applied to the first cutting insert also from the front end surface side of the holder in addition to the outer peripheral surface side of the holder. .

In the cutting tool of the said aspect, since the axial rake of a 1st cutting insert is relatively large, the load added from the front end surface side of a holder can be made small. Therefore, variation in load applied to the first cutting insert and the second cutting insert can be suppressed.

It is a perspective view which shows the cutting tool of one Embodiment. It is a side view of the cutting tool shown in FIG. It is the side view to which the area | region A in the cutting tool shown in FIG. 2 was expanded. It is the top view which looked at the cutting tool shown in FIG. 1 from the front end side. It is the side view which looked at the 1st cutting insert and 2nd cutting insert in the cutting tool shown in FIG. 1 from the front of the rotation direction. It is a perspective view which shows the 1st cutting insert in the cutting tool shown in FIG. It is the side view which looked at the 1st cutting insert shown in Drawing 6 from the 1st front side. It is the side view which looked at the 1st cutting insert shown in Drawing 6 from the 1st upper surface side. It is the side view which looked at the 1st cutting insert shown in FIG. 6 from the 1st outer surface side. It is sectional drawing of the B1-B1 cross section in the 1st cutting insert shown in FIG. It is sectional drawing of the B2-B2 cross section in the 1st cutting insert shown in FIG. It is sectional drawing of the B3-B3 cross section in the 1st cutting insert shown in FIG. It is sectional drawing of the B4-B4 cross section in the 1st cutting insert shown in FIG. It is sectional drawing of the B5-B5 cross section in the 1st cutting insert shown in FIG. It is a perspective view which shows the 2nd cutting insert in the cutting tool shown in FIG. It is the side view which looked at the 2nd cutting insert shown in Drawing 15 from the 2nd front side. It is the side view which looked at the 2nd cutting insert shown in Drawing 15 from the 2nd upper surface side. It is the side view which looked at the 2nd cutting insert shown in FIG. 15 from the 2nd outer surface side. It is the schematic which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention. It is the schematic which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention. It is the schematic which shows 1 process of the manufacturing method of the cut workpiece of one Embodiment of this invention.

  Hereinafter, the cutting tool of one embodiment is explained in detail using a drawing. However, each drawing referred to below shows only the main members in a simplified manner for the convenience of explanation. Therefore, the cutting tool of the present invention may include any constituent member that is 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.

The cutting tool 1 of this embodiment is equipped with the holder 3 and the some cutting insert 5 (henceforth the insert 5) as shown in FIGS. The cutting tool 1 of this embodiment includes a plurality of first cutting inserts 5 </ b> A (hereinafter also referred to as first inserts 5 </ b> A) and a plurality of second cutting inserts 5 </ b> B (hereinafter referred to as second cutting inserts) as the plurality of cutting inserts 5. Insert 5B).

  The holder 3 has a rotation axis X, and is a cylindrical member extending along the rotation axis X from the front end side toward the rear end side. At the time of cutting the work material for manufacturing the work, the holder 3 rotates about the rotation axis X around the rotation axis X. In the present embodiment, the central axis of the cylindrical holder 3 and the rotation axis X of the holder 3 coincide.

  As the holder 3, steel, cast iron, aluminum alloy or the like can be used. In the cutting tool 1 of this embodiment, steel with high toughness is used among these members. The size of the holder 3 is appropriately set according to the size of the work material. For example, the length in the direction along the rotation axis X is set to about 30 to 90 mm. Moreover, the width | variety of the direction orthogonal to the rotating shaft X is set to about 20-500 mm.

  A plurality of notches 7 are provided on the tip side of the holder 3. The plurality of notches 7 are provided so as to be rotationally symmetric about the rotation axis X when the holder 3 is viewed from the tip. The interval between the notch portions 7 adjacent to each other may be different, but in order to suppress variation in the load applied to the cutting insert 5 attached to each notch portion 7, the interval between the notch portions 7 adjacent to each other. Is preferably constant.

  Each of the plurality of notches 7 is provided with a first insert pocket 9 (hereinafter also referred to as a first pocket 9) and a second insert pocket 11 (hereinafter also referred to as a second pocket 11). . That is, the holder 3 in the present embodiment has a plurality of first pockets 9 and a plurality of second pockets 11.

  The plurality of first pockets 9 are open to the front end surface and the outer peripheral surface of the holder 3, respectively. The plurality of second pockets 11 are located on the rear end side of the holder 3 with respect to the first pocket 9, respectively, and open on the outer peripheral surface of the holder 3.

  The first pocket 9 is a portion to which the first insert 5 </ b> A is attached in the holder 3. The first insert 5 </ b> A partially protrudes from the tip surface and the outer peripheral surface of the holder 3. The second pocket 11 is a portion to which the second insert 5 </ b> B is attached in the holder 3. The second insert 5 </ b> B partially protrudes from the outer peripheral surface of the holder 3. In the present embodiment, five first pockets 9 and five second pockets 11 are provided in the holder 3.

  Each of the five first pockets 9 is provided with a first insert 5A. Therefore, in the cutting tool 1 of the present embodiment, five first inserts 5A are attached. Each of the five second pockets 11 is provided with a second insert 5B. Therefore, in the cutting tool 1 of this embodiment, the 5 2nd insert 5B is attached. Note that the number of the first insert 5A and the second insert 5B is not limited to five. There is no problem even if these numbers are, for example, 2, 3, 4, 5, or 8.

  As shown in FIGS. 6 to 14, the first insert 5 </ b> A attached to the first pocket 9 includes a first front side surface 13, a first rear side surface 15, a first upper side surface 17, and a first lower side surface. 19, a first outer surface 21 and a first inner surface 23. The first upper side surface 17 and the first lower side surface 19 in the present embodiment are pentagonal. The first front side surface 13 is located on the front side in the rotation direction Y around the rotation axis X, and has a rectangular shape when viewed from the front side in the rotation direction Y around the rotation axis X. Yes. The first rear side surface 15 is opposite to the first front side surface 13 and is located on the rear side in the rotation direction Y around the rotation axis X.

  Note that the first front side surface 13 does not need to be a rectangle in a strict sense, and may be, for example, a rounded shape when the four corners of the rectangle are viewed from the front. . Moreover, the side part located so as to connect the adjacent corners may not have a strict linear shape but may have a partly uneven shape.

  The first upper side surface 17 is a surface adjacent to the long side of the first front side surface 13 having a rectangular shape. The first upper side surface 17 is a surface located on the rear end side (the upper side in FIG. 2) of the holder 3 when attached to the first pocket 9, and comes into contact with the first pocket 9. The first lower side surface 19 is a surface opposite to the first upper side surface 17 and is adjacent to the long side of the first front side surface 13 which is rectangular like the first upper side surface 17. . The first lower side surface 19 is a surface located on the distal end side (lower side in FIG. 2) of the holder 3 when attached to the first pocket 9, and projects in the distal direction from the holder 3.

  The first inner side surface 23 is a surface adjacent to the short side of the first front side surface 13 having a rectangular shape. The first inner side surface 23 is a surface located on the center side of the holder 3 when attached to the first pocket 9, and abuts on the first pocket 9. The first outer side surface 21 is a surface opposite to the first inner side surface 23, and is adjacent to the short side of the first front side surface 13 that is rectangular like the first inner side surface 23. . The first outer surface 21 is a surface located on the outer peripheral side of the holder 3 when attached to the first pocket 9, and protrudes in the outer peripheral direction from the holder 3.

  The first insert 5A has a 180 ° rotationally symmetric shape with a central axis passing through the center of the first front side surface 13 and the center of the first rear side surface 15 as a reference. That is, the first upper surface 17 becomes the first lower surface 19 and the first lower surface 19 becomes the first upper surface 17 by rotating the first insert 5A by 180 ° with respect to the central axis. become. Also, the first inner surface 23 becomes the first outer surface 21, and the first outer surface 21 becomes the first inner surface 23.

  A first tip cutting edge 25 is formed on the ridgeline where the first front side surface 13 and the first lower side surface 19 intersect. The first tip cutting edge 25 is positioned so as to protrude from the tip surface of the holder 3. Since the first insert 5A has a 180 ° rotationally symmetric shape, a cutting edge similar to the first tip cutting edge 25 is also formed on the ridgeline where the first front side surface 13 and the first upper side surface 17 intersect. Is formed. The first tip cutting edge 25 is inclined so as to approach the first rear side surface 15 from the end on the outer peripheral side toward the end on the inner peripheral side.

  A first outer peripheral cutting edge 27 is formed on the ridgeline where the first front side surface 13 and the first outer side surface 21 intersect. The first outer peripheral cutting edge 27 is positioned so as to protrude outward from the outer peripheral surface of the holder 3. Since the first insert 5A has a 180 ° rotationally symmetric shape, a cutting edge similar to the first outer peripheral cutting edge 27 is also formed on the ridge line where the first front side surface 13 and the first inner side surface 23 intersect. Is formed. The first outer peripheral cutting edge 27 is inclined so as to approach the first rear side surface 15 from the end portion on the front end side of the holder 3 toward the end portion on the rear end side. The first tip cutting edge 25 is formed on the long side portion of the first front side surface 13, and the first outer peripheral cutting edge 27 is formed on the short side portion of the first front side surface 13.

  In the first insert 5A in the present embodiment, the first front side surface 13 is located on the front side in the rotation direction Y around the rotation axis X, and functions as a so-called rake face. The first lower surface 19 and the first outer surface 21 function as so-called flank surfaces. On the first front side surface 13, a first tip side rake face 29 provided along the first tip cutting edge 25 and a first outer periphery side provided along the first outer peripheral cutting edge 27. A rake face 31 is formed.

The first pocket 9 is open to the front end surface and the outer peripheral surface of the holder 3, and the first insert 5
A first cutting edge 25 in A protrudes toward the work material. For this reason, when the chips generated by the first outer peripheral cutting edge 27 travel toward the front end side, the chips may come into contact with the processed surface of the work material and damage the processed surface. However, in the present embodiment, when the first outer peripheral rake face 31 is viewed from the front in the rotational direction Y around the rotation axis X, the width becomes narrower as the distance from the front end face of the holder 3 increases. Yes. Therefore, the chips generated by the first outer peripheral cutting edge 27 are likely to advance toward the rear end side of the holder 3. Thereby, possibility that the processing surface of a workpiece will be damaged can be made small.

  As shown in FIGS. 15 to 18, the second insert 5 </ b> B attached to the second pocket 11 includes a second front side 33, a second rear side 35, a second upper side 37, and a second lower side. 39, a second outer surface 41 and a second inner surface 43. In the present embodiment, the second outer side surface 41 and the second inner side surface 43 are pentagonal. The second front side surface 33 is located on the front side in the rotation direction Y around the rotation axis X, and has a rectangular shape when viewed from the front side in the rotation direction Y around the rotation axis X. Yes. The second rear side surface 35 is located on the opposite side of the second front side surface 33 and on the rear side in the rotational direction Y around the rotation axis X. In addition, the 2nd front side surface 33 in the above does not need to be a rectangle in a strict meaning like the 1st front side surface 13. FIG.

  The second upper side surface 37 is a surface adjacent to the short side of the second front side surface 33 having a rectangular shape. The second upper side surface 37 is a surface located on the rear end side (the upper side in FIG. 2) of the holder 3 when attached to the second pocket 11, and comes into contact with the second pocket 11. The second lower side surface 39 is a surface opposite to the second upper side surface 37, and is adjacent to the short side of the second front side surface 33 that is rectangular like the second upper side surface 37. .

  The second inner side surface 43 is a surface adjacent to the long side of the second front side surface 33 having a rectangular shape. The second inner side surface 43 is a surface located on the center side of the holder 3 when attached to the second pocket 11, and abuts on the second pocket 11. The second outer side surface 41 is a surface opposite to the second inner side surface 43, and is adjacent to the long side of the second front side surface 33 that is rectangular like the second inner side surface 43. . The second outer surface 41 is a surface located on the outer peripheral side of the holder 3 when attached to the second pocket 11, and protrudes in the outer peripheral direction from the holder 3.

  The second insert 5B has a 180 ° rotationally symmetric shape with a central axis passing through the center of the second front side surface 33 and the center of the second rear side surface 35 as a reference. That is, by rotating the second insert 5B by 180 ° with respect to this central axis, the second upper side surface 37 becomes the second lower side surface 39, and the second lower side surface 39 becomes the second upper side surface 37. become. Further, the second inner surface 43 becomes the second outer surface 41, and the second outer surface 41 becomes the second inner surface 43.

  A second tip cutting edge 45 is formed on the ridgeline where the second front side surface 33 and the second lower side surface 39 intersect. A second outer peripheral cutting edge 47 is formed on the ridgeline where the second front side surface 33 and the second outer side surface 41 intersect. The second tip cutting edge 45 is inclined so as to approach the second rear side surface 35 from the end on the outer peripheral side toward the end on the inner peripheral side.

  The second outer peripheral cutting edge 47 is positioned so as to protrude outward from the outer peripheral surface of the holder 3. Since the second insert 5B has a 180 ° rotationally symmetric shape, a cutting edge similar to the second outer peripheral cutting edge 47 is also formed on the ridgeline where the second front side surface 33 and the second inner side surface 43 intersect. Is formed. The second outer peripheral cutting edge 47 is inclined so as to approach the second rear side surface 35 from the end on the front end side of the holder 3 toward the end on the rear end side.

The second tip cutting edge 45 is formed on the short side portion of the second front side surface 33, and the second outer peripheral cutting edge 47 is formed on the long side portion of the second front side surface 33. Therefore, when the second tip cutting edge 45 and the second outer peripheral cutting edge 47 are compared, the second outer peripheral cutting edge 47 is longer than the second tip cutting edge 45.

  Since the second pocket 11 to which the second insert 5B is attached is located on the rear end side of the holder 3 relative to the first pocket 9 to which the first insert 5A is attached, the second tip cutting The blade 45 may not be used in the cutting process.

  In the second insert 5B in the present embodiment, the second front side surface 33 is located on the front side in the rotation direction Y around the rotation axis X, and functions as a so-called rake face. The second outer surface 41 functions as a so-called flank. A second outer peripheral rake face 49 provided along the second outer peripheral cutting edge 47 is formed on the second front side surface 33.

  The second outer peripheral rake face 49 includes a first region 49a that increases in width as it moves away from the front end face of the holder 3 when viewed from the front in the rotational direction Y around the rotation axis X. The second region 49b is located on the rear end side of the region 49a and decreases in width as the distance from the front end surface of the holder 3 increases. Therefore, the second outer peripheral rake face 49 has a convex shape along the second outer peripheral cutting edge 47.

  Since the length of the second outer peripheral cutting edge 47 is relatively large, the second outer peripheral cutting edge 47 is liable to generate wide and unstable chips. However, as the second outer rake face 49 has a convex shape having the first region 49a and the second region 49b as described above, the flow of chips is stabilized. For this reason, it is possible to further improve the discharge performance of the chips generated in the second outer peripheral cutting edge 47.

  The second insert 5B may have a shape different from that of the first insert 5A. In the present embodiment, the second insert 5B has the same shape as the first insert 5A. Specifically, the first front side surface 13 of the first insert 5A and the second front side surface 33 of the second insert 5B have the same shape. The first rear side surface 15 in the first insert 5A and the second rear side surface 35 in the second insert 5B have the same shape. The first upper side surface 17 and the first lower side surface 19 in the first insert 5A and the second inner side surface 43 and the second outer side surface 41 in the second insert 5B have the same shape. Further, the first inner side surface 23 and the first outer side surface 21 in the first insert 5A and the second upper side surface 37 and the second lower side surface 39 in the second insert 5B have the same shape.

  The second insert 5B is attached to the holder 3 in a state where the first insert 5A is rotated 90 ° around the central axis. Therefore, when viewed from the front of the rotation direction Y around the rotation axis X, the first insert 5A is mounted on the holder 3 so that the front side surface is horizontally long as shown in FIG. As shown in FIG. 5, the first insert 5 </ b> A is attached to the holder 3 so that the front side surface is vertically long. Since the first insert 5A and the second insert 5B have the same shape, it is not necessary to prepare separate inserts, so that the cutting tool 1 is excellent in economic efficiency.

  The first insert 5A and the second insert 5B need not be exactly the same in shape and may vary in production.

Examples of the material of the first insert 5A and the second insert 5B 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 includes a titanium compound mainly composed of titanium carbide (TiC) or titanium nitride (TiN).

The surfaces of the first insert 5A and the second insert 5B 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 sizes of the first insert 5A and the second insert 5B are not particularly limited. For example, in the first insert 5A of the present embodiment, the front side when viewed from the front side is directed to the rear side. The maximum value of the width in the direction is set to about 5 to 20 mm. Further, the maximum value of the width in the direction from the inner surface to the outer surface when viewed from the front end is set to about 5 to 20 mm. The maximum value in the direction along the rotation axis X from the upper side surface to the lower side surface is 3 to 10 mm. The second insert 5B is also set to the same size as the first insert 5A.

  The first insert 5 </ b> A in the present embodiment has a first through hole 51 that penetrates from the first lower surface 19 to the first upper surface 17. The second insert 5 </ b> B has a second through hole 53 that penetrates from the second outer surface 41 to the second inner surface 43. The first through hole 51 and the second through hole 53 are provided for inserting a screw 55 when the insert 5 is fixed to the holder 3 with a screw. Screws 55 are inserted into the first through hole 51 and the second through hole 53, respectively, and the tips of the screws 55 are inserted into screw holes (not shown) formed in the first pocket 9 and the second pocket 11. Then, the first insert 5A and the second insert 5B are fixed to the holder 3 by screwing the screw portions.

  The first insert 5A is attached to the first pocket 9 at the inclination angles of the axial rake θ1 and the radial rake φ1. The second insert 5B is attached to the second pocket 11 at the inclination angles of the axial rake θ2 and the radial rake φ2. At this time, in the cutting tool 1 of the present embodiment, the axial rake θ1 of the first insert 5A is larger than the axial rake θ2 of the second insert 5B.

  While the second pocket 11 is open on the outer peripheral surface of the holder 3, the first pocket 9 is open on the tip surface and the outer peripheral surface of the holder 3. Therefore, a load is applied to the second insert 5B attached to the second pocket 11 mainly from the outer peripheral surface side of the holder 3, whereas a holder is attached to the first insert 5A attached to the first pocket 9 In addition to the outer peripheral surface side of 3, a load is also applied from the front end surface side of the holder 3. For this reason, the load applied to the first insert 5A tends to be relatively large.

  Although a load is applied to the first insert 5A from the front end surface side of the holder 3 by cutting using the first front end cutting edge 25, in the cutting tool 1 of the present embodiment, the axial rake θ1 of the first insert 5A. Is relatively large, the applied load can be reduced. Therefore, the difference between the load applied to the first insert 5A and the load applied to the second insert 5B can be reduced, and variation in the load applied to the first insert 5A and the second insert 5B can be suppressed. Can do.

  Further, when the axial rake θ2 of the second insert 5B is also relatively large, chips generated by the second outer peripheral cutting edge 47 can easily flow toward the rear end side of the holder 3, and the second outer peripheral side There is a possibility that the rake face 49 cannot sufficiently curl the chips. Therefore, chips may become excessively long, and chip treatment may become unstable. However, in the present embodiment, since the axial rake θ2 of the second insert 5B is relatively small, the chips can be curled stably and good chip treatment can be performed.

  As 1st axial rake | theta (theta) 1, it can set to about 5-20 degrees, for example. The second axial rake θ2 may be a value smaller than the first axial rake θ1, and can be set to about 3 to 15 °, for example.

  When the cutting tool 1 is viewed from the side, the first axial rake θ1 connects the end portion on the first lower side surface 19 side and the end portion on the first upper side surface 17 side of the first outer peripheral cutting edge 27. This is indicated by an angle formed between the virtual straight line and a virtual straight line parallel to the rotation axis X. Further, the second axial rake θ2 is obtained when the cutting tool 1 is viewed from the side, and the second outer side cutting edge 47 has an end on the second lower side 39 side and an end on the second upper side 37 side. And an angle formed by a virtual straight line connecting the two and a virtual straight line parallel to the rotation axis X.

  In the present embodiment, the radial rake φ1 of the first insert 5A is larger than the radial rake φ2 of the second insert 5B. In the first insert 5A, cutting is performed using the first tip cutting edge 25. However, since the radial rake φ1 of the first insert 5A is relatively large, Good machinability. Therefore, the possibility that chatter vibration occurs can be reduced. Further, since the radial rake φ2 of the second insert 5B is relatively small, chips generated in the second insert 5B can be easily discharged to the outer peripheral side.

  The radial rakes φ1 and φ2 described above are not shown in absolute values but include positive and negative signs. Therefore, for example, when the radial rake φ1 is 5 ° and the radial rake φ2 is −10 °, it can be said that φ1 is larger than φ2.

  When the radial rake is a positive value, the chips can easily travel inward, that is, toward the rotation axis X. Further, since the radial rake is a negative value, the chips can easily move toward the outer peripheral side. In the present embodiment, the radial rake of the first insert 5A is a positive value, and the radial rake of the second insert 5B is a negative value. Therefore, the advancing direction of the chip generated in the first insert 5A can be divided from the advancing direction of the chip generated in the second insert 5B. Thereby, the possibility that the chips generated in the first insert 5A and the chips generated in the second insert 5B collide with each other can be reduced.

  The first radial rake φ1 is formed by a virtual straight line connecting the first tip cutting edge 25 and the rotation axis X and a virtual straight line parallel to the first rear side surface 15 when the cutting tool 1 is viewed from the tip. Indicated by the corners. Further, the second radial rake φ2 includes a virtual straight line connecting the second tip cutting edge 45 and the rotation axis X and a virtual straight line parallel to the second rear side surface 35 when the cutting tool 1 is viewed from the tip. Indicated by the angle between

  However, when the rear side surface is not linear when the cutting tool 1 is viewed from the tip like the second rear side surface 35 in the present embodiment, the outer peripheral end and the inner peripheral end of the rear side A virtual straight line connecting the two can be set, and the radial rake can be evaluated by an angle formed with the virtual straight line.

  When the virtual straight line connecting the cutting edge and the rotation axis X is positioned in front of the rotation direction Y around the rotation axis X with respect to the tangent line parallel to the rear side surface, the radial rake is positive. It is assumed that the radial rake is a negative value when the virtual straight line is located behind the tangent line in the rotation direction Y around the rotation axis X.

  The holder 3 in the present embodiment has a plurality of notches 7 that open to the front end surface and the outer peripheral surface, and a first pocket 9 and a second pocket 11 are formed in each of the plurality of notches 7. However, it is not limited to such a form. For example, a first notch and a second notch are provided as the notch 7, and the first pocket 9 is formed in the first notch, and the second notch is provided with the second notch. A pocket 11 may be formed.

  However, when the 1st pocket 9 and the 2nd pocket 11 are formed in each of a plurality of notch parts 7 like this embodiment, the space | interval of the adjacent notch part 7 is ensured widely. Therefore, the thickness of the holder 3 in the portion located behind the first insert 5A and the second insert 5B can be ensured thick. Therefore, it becomes possible to improve the durability of the holder 3.

  As mentioned above, although the cutting tool 1 of one Embodiment was demonstrated in detail using drawing, the cutting tool of this invention is not limited to the structure of said embodiment.

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

  More specifically, first, as shown in FIG. 19, the cutting tool 1 is rotated around the rotation axis X, and the cutting tool 1 is relatively moved closer to the work material 101. Next, the cutting edge of the cutting tool 1 is brought into contact with the work material 101 to cut the work material 101. As shown in FIG. 20, in this embodiment, the first tip cutting edge and the first outer peripheral cutting edge of the first insert 5A and the second outer peripheral cutting edge of the second insert 5B are covered as cutting edges. It is made to contact the cutting material 101. Then, as shown in FIG. 21, the cutting tool 1 is relatively moved away from the work material 101.

  In the present embodiment, the work material 101 is fixed and brought close to the work material 101 in a state where the cutting tool 1 is rotated around the rotation axis X. In FIG. 20, the first tip cutting edge and the first outer peripheral cutting edge of the rotating first insert 5A and the second outer peripheral cutting edge of the second insert 5B are brought into contact with the work material 101. Thus, the work material 101 is cut. In FIG. 21, the cutting tool 1 is rotated away from the work material 101.

  In the cutting in the manufacturing method of this embodiment, the cutting tool 1 is brought into contact with the work material 101 by moving the cutting tool 1 in each step, or the cutting tool 1 is separated from the work material 101. However, as a matter of course, it is not limited to such a form.

  For example, the work material 101 may be brought close to the cutting tool 1 in the step (1). Similarly, the work material 101 may be moved away from the cutting tool 1 in the step (3). In the case of continuing the cutting process, the state in which the cutting tool 1 is rotated may be maintained, and the process of bringing the cutting edge in the insert 5 into contact with a different part of the work material 101 may be repeated.

In addition, all of the first tip cutting edge and the first outer peripheral cutting edge of the first insert 5A and the second outer peripheral cutting edge of the second insert 5B must be brought into contact with the work material 101 as cutting edges. It doesn't mean you have to. For example, while the first tip cutting edge and the first outer peripheral cutting edge of the first insert 5A are in contact with the work material 101, the second outer peripheral cutting edge of the second insert 5B is separated from the work material. Cutting may be performed in a state of being cut.

  Note that typical examples of the material of the work material 101 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metal.

DESCRIPTION OF SYMBOLS 1 ... Cutting tool 3 ... Holder 5 ... Cutting insert (insert)
5A ... 1st cutting insert (1st insert)
5B ... 2nd cutting insert (2nd insert)
7 ... Notch 9 ... 1st insert pocket (1st pocket)
11 ... Second insert pocket (second pocket)
DESCRIPTION OF SYMBOLS 13 ... 1st front side surface 15 ... 1st rear side surface 17 ... 1st upper side surface 19 ... 1st lower side surface 21 ... 1st outer side surface 23 ... 1st 1 inner surface 25... First tip cutting edge 27... First outer peripheral cutting blade 29... First tip side rake face 31. Second front side surface 35 ... second rear side surface 37 ... second upper side surface 39 ... second lower side surface 41 ... second outer side surface 43 ... second inner side surface 45 ... second tip cutting edge 47 ... second outer peripheral cutting edge 49 ... second outer peripheral rake face 49a ... first area 49b ... second area 51 ··· -1st through-hole 53 ... 2nd through-hole 55 ... Screw 101 ... Work material

Claims (5)

A holder having a first insert pocket and a second insert pocket located on the rear end side of the first insert pocket and extending from the front end side toward the rear end side along the rotation axis;
A first cutting insert attached to the first insert pocket and partially protruding from a tip surface and an outer peripheral surface of the holder;
A cutting tool comprising a second cutting insert attached to the second insert pocket and partially protruding from the outer peripheral surface of the holder,
The axial rake of the first cutting insert is much larger than the axial rake of the second cutting insert,
The first cutting insert has a first outer peripheral cutting edge located on the outer peripheral surface side of the holder, and a first outer peripheral rake face provided along the first outer peripheral cutting edge,
When viewed from the front in the rotational direction around the rotation axis, the first outer peripheral side rake surface has a width that decreases as the distance from the tip surface of the holder increases.
The second cutting insert has a second outer peripheral cutting edge located on the outer peripheral surface side of the holder, and a second outer peripheral rake face provided along the second outer peripheral cutting edge,
The second outer peripheral side rake face has a first region whose width becomes wider as it moves away from the tip end face of the holder when viewed from the front in the rotation direction around the rotation axis; A cutting tool comprising: a second region that is located closer to the rear end side than the region and decreases in width as it moves away from the tip surface of the holder .   The cutting tool according to claim 1, wherein a radial rake of the first cutting insert is larger than a radial rake of the second cutting insert.   3. The cutting tool according to claim 2, wherein the radial rake of the first cutting insert is a positive value and the radial rake of the second cutting insert is a negative value. The holder has a plurality of notches that open to the front end surface and the outer peripheral surface;
The cutting tool according to any one of claims 1 to 3 , wherein the first insert pocket and the second insert pocket are formed in each of the plurality of notches. The step of rotating the cutting tool according to any one of claims 1 to 4 around the rotation axis;
Contacting the work piece with the cutting edge of the rotating cutting tool;
The manufacturing method of the cut workpiece provided with the process of separating the said cutting tool from the said workpiece.

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