JP5898028B2 - Cutting tool and method of manufacturing workpiece - Google Patents

Description

  The present invention relates to a cutting tool used for cutting a workpiece and a method for manufacturing a workpiece.

  As a cutting tool used for cutting a work material, a cutting tool described in Patent Document 1 is known. The cutting tool described in Patent Literature 1 includes a cutting insert having a flat index surface on a curved side surface, and a tool body having a mounting seat to which the cutting insert is attached. The mounting seat has a seat side surface against which the indexing surface comes into contact. Further, a convex portion is provided on the indexing surface, and a concave portion that engages with the convex portion is provided on the mounting seat.

JP 2011-245585 A

  In recent years, in order to perform fine cutting, a cutting tool having a small cutting insert is required. However, when the cutting insert is reduced in size, the contact area between the cutting insert and the tool body is reduced. Therefore, it may be difficult to stably hold the cutting insert with the tool body. Further, when the cutting insert is downsized, the difference in distance from the central axis between the flat index surface on the side surface and the curved area other than the index surface is small. For this reason, when the cutting insert is attached, there is a possibility that the curved region, not the index surface, may be erroneously mounted in a state where it is in contact with the seat side surface of the tool body.

  The present invention has been made in view of the above problems, and provides a cutting tool in which a cutting insert is stably attached to a tool body even when the cutting insert is downsized, and a method for manufacturing a cut product. There is to do.

A cutting tool according to an aspect of the present invention includes a holder having an insert pocket on the tip side, an upper surface, a lower surface, an outer surface connected to each of the upper surface and the lower surface, and a through-hole formed from the upper surface to the lower surface And a cutting insert that is provided in the insert pocket so as to protrude from the tip of the holder, and an upper cutting edge that is positioned at the intersection of the upper surface and the outer surface, and the through hole And a screw for fixing the cutting insert to the holder. The outer surface of the cutting insert has a curved region that is arcuate and a planar region that is linear in a cross section orthogonal to the central axis of the through hole. The insert pocket has a planar bottom surface in contact with the lower surface of the cutting insert, a curved first inner surface in contact with the curved region, and a planar second inner surface in contact with the planar region. . Before SL insert pocket and having a protrusion protruding from the second inner surface, the planar region, has a recess in which the protrusion is accommodated. The convex portion is formed at the lower end of the second inner surface, and the concave portion is formed from the planar region to the lower surface of the cutting insert. In a cross section orthogonal to the central axis of the through hole, the distance from the center of the through hole to the center of the curved region is L1, and the distance from the center of the through hole to the center of the planar region is L2. (D1-D2) − (L1) where D1 is the inner diameter of the through hole, D2 is the outer diameter of the screw, and Z is the size of the protrusion protruding from the second inner surface. -L2) <Z .

In the cutting insert of the said aspect, the outer side surface of the cutting insert has a curved surface area | region and a plane area | region, and an insert pocket has a 1st inner surface and a 2nd inner surface. Therefore, rotation of the cutting insert attached to the insert pocket can be suppressed while ensuring a contact area between the outer surface of the cutting insert and the inner surface of the insert pocket. Moreover, since the 2nd inner surface instead of the 1st inner surface has a convex part, and not a curved surface area but a plane area | region has a recessed part, it can prevent that a cutting insert is mounted | worn erroneously.

It is a perspective view which shows the cutting tool of the 1st Embodiment of this invention. It is an expansion perspective view which shows the front-end | tip part of the holder in the cutting tool shown in FIG. It is the perspective view which expanded the area | region A in the cutting tool shown in FIG. It is a perspective view from the lower surface side which shows the cutting insert in the cutting tool shown in FIG. It is the perspective view which expanded the area | region B in the cutting insert shown in FIG. It is the side view to which the part in which the cutting insert in the cutting tool shown in FIG. 1 was mounted | wore was expanded. It is sectional drawing from the same direction as the side view shown in FIG. It is the perspective view which expanded the area | region C in the cutting tool shown in FIG. It is a side view which shows the case where the cutting insert in the cutting tool shown in FIG. It is sectional drawing from the same direction as the side view shown in FIG. It is sectional drawing of the DD cross section 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, the cutting tool of one embodiment is explained in detail using a drawing. 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 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.

  As shown in FIGS. 1 to 8, the cutting tool 1 according to this embodiment includes a holder 101 having an insert pocket 103 on the tip side, a cutting insert 201 mounted in the insert pocket 103, and the cutting insert 201 fixed to the holder 101. The screw 301 is provided. Hereinafter, each component will be described in order.

  In FIG. 2, the bottom surface 105 of the insert pocket 103 faces left and right so as to be orthogonal to the rotation direction of the holder 101. However, in order to facilitate understanding of the configuration, the bottom surface 105 is on the upper side in FIG. 3. The orientation of the figure has been changed to face. 7, 8 and 10 are cross sections along the central axis of the through-hole 211. In order to facilitate visual understanding, the screw 301 is shown in FIGS. 8 and 11, but the screw 301 is omitted in FIGS.

<Cutting insert 201>
The cutting insert 201 in this embodiment has the upper surface 203, the lower surface 205, and the outer surface 207, as shown to FIGS. The outer side surface 207 is connected to the upper surface 203 and the lower surface 205, respectively. An upper cutting edge 209 is located at the intersection of the upper surface 203 and the outer surface 207. By cutting the work material using the upper cutting edge 209, it is possible to manufacture a cut product to be described later.

A through hole 211 is formed from the upper surface 203 to the lower surface 205. In the present embodiment, a through hole 211 is formed from the center of the upper surface 203 to the center of the lower surface 205. The through hole 211 is provided for inserting a screw 301 when the cutting insert 201 is fixed to the holder 101 of the cutting tool 1 with a screw. When the central axis of the through hole 211 is X, the upper surface 203 and the lower surface 205 are provided to be perpendicular to the central axis X.

  In the present embodiment, the penetration direction of the through hole 211, in other words, the direction in which the central axis X extends is the vertical direction. Of the surfaces where the through holes 211 open, the surface where the cutting edge (upper cutting edge 209) is formed at the intersection with the outer surface 207 is the upper surface 203, and the surface where the upper cutting edge 209 is not formed. The lower surface 205 is used. Therefore, the vertical direction of the cutting insert 201 and the cutting tool 1 of the present embodiment described in detail below does not necessarily coincide with the direction of the cutting insert 201 in use.

  In the present embodiment, the upper surface 203 and the lower surface 205 each have a substantially circular shape when viewed in plan. The lower surface 205 is formed slightly smaller than the upper surface 203. Therefore, the outer surface 207 is inclined so as to approach the central axis X as it approaches the lower surface 205 side from the upper surface 203 side.

  Note that the shapes of the upper surface 203 and the lower surface 205 are not limited to the above forms. For example, the shape of the upper surface 203 in a plan view may be a polygonal shape such as a triangle, a quadrangle, a pentagon, a hexagon, or an octagon. Moreover, even if it is a case where it has a curve site | part, it is not limited to circular arc shape. It may be a convex curve that is convex outward, such as a parabola or an elliptic curve.

  Examples of the material of the cutting insert 201 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 surface of the cutting insert 201 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 maximum width of the upper surface 203 and the lower surface 205 in the cutting insert 201 of this embodiment is 5 to 30 mm. The height from the lower surface 205 to the upper surface 203 is 2 to 8 mm. Here, the height from the lower surface 205 to the upper surface 203 means a width in a direction parallel to the central axis X between the upper end of the upper surface 203 and the lower end of the lower surface 205.

  The upper surface 203 has a land surface 213, a rake surface 215, a breaker surface 217, and a main surface 219, as shown in FIGS. The land surface 213 is located on the outer peripheral edge of the upper surface 203 and is connected to the upper cutting blade 209. The rake face 215 is located closer to the center than the land face 213. The rake face 215 is an inclined surface whose height decreases as it goes toward the center. The breaker surface 217 is located closer to the center than the rake surface 215. Further, the breaker surface 217 is a concave region constituted by a portion of an inclined surface that decreases in height toward the center and a portion that is located closer to the center than the inclined surface and increases in height. The main surface 219 is located closer to the center than the breaker surface 217. The main surface 219 is a flat surface perpendicular to the central axis X.

  An upper cutting edge 209 is formed at the intersection of the land surface 213 and the side surface. The land surface 213 is provided to increase the strength of the upper cutting edge 209. When the land surface 213 is not provided, the upper cutting edge 209 is formed at the intersection of the rake surface 215 and the side surface. As described above, the rake surface 215 located inside the land surface 213 is an inclined surface whose height decreases toward the center. For this reason, the internal angle formed by the rake face 215 and the side face is small. However, since the internal angle formed by the land surface 213 and the side surface is larger than the internal angle formed by the rake surface 215 and the side surface, the strength of the upper cutting edge 209 can be increased by having the land surface 213.

  In addition, if it aims at improving the machinability of the upper cutting edge 209, it is good also as a structure by which the upper cutting edge 209 was formed in the intersection part of the rake face 215 and a side surface. This is because the upper cutting edge 209 has a sharp shape. The width of the land surface 213 indicated by the distance between the outer periphery of the upper surface 203 and the outer periphery of the rake face 215 is appropriately set according to the cutting conditions.

  The rake face 215 is located inside the land face 213. It is an inclined surface whose height decreases toward the center. Since the rake face 215 only needs to have a height that decreases toward the center, the rake face 215 may be configured by a plurality of regions having different inclination angles when viewed in cross-section, and has a concave curve shape. Also good.

  The breaker surface 217 is located inside the land surface 213. The region near the main surface 219 on the breaker surface 217 increases in height as the distance from the outer periphery increases. Specifically, the breaker surface 217 is an inclined surface whose height on the center side is higher than that on the outer peripheral side of the upper surface 203.

  An outer surface 207 is formed between the upper surface 203 and the lower surface 205. The outer side surface 207 is connected to each of the upper surface 203 and the lower surface 205. The outer surface 207 of the cutting insert 201 has a curved surface area 207 a that is arcuate and a planar area 207 b that is linear in a cross section orthogonal to the central axis X of the through-hole 211, that is, a cross section parallel to the upper surface 203 or the lower surface 205. have. Therefore, as shown in FIG. 4, the outer surface 207 of the cutting insert 201 in the present embodiment has a curved surface area 207a and a flat area 207b.

  Such a planar region 207b can function as a so-called index surface. That is, in the above cross section, when the outer surface 207 is arcuate, the distance from the central axis X is constant, so that the cutting insert 201 is easy to rotate around the central axis X. On the other hand, in the case of the plane region 207b, a reaction force is generated in the direction in which the cutting insert 1 rotates, and therefore the cutting insert 1 is difficult to rotate. At this time, the insert pocket 103 of the holder 101 is in contact with the flat bottom surface 105 in contact with the lower surface 205 of the cutting insert 201, the curved first inner surface 107 in contact with the curved region 207a, and the flat region 207b, as will be described later. A planar second inner surface 109 is provided.

  However, when the planar area 207b is reduced as in the case where the cutting insert 201 is downsized, the difference between the distance from the central axis X to the planar area 207b and the distance from the central axis X to the curved area 207a is reduced. Therefore, the anti-rotation force in the flat area 207 b is weakened, or the “play” that is the difference in size between the through hole 211 and the screw 301 causes the flat area 207 b of the cutting insert 201 to be moved into the first inner pocket 103 of the insert pocket 103. There is a possibility that the side surface 107 and the curved surface region 207a of the cutting insert 201 are erroneously mounted in a state where the curved surface region 207a is in contact with the second inner side surface 109 of the insert pocket 103.

  In the cutting tool 1 of the present embodiment, as shown in FIGS. 4 to 8, the insert pocket 103 has the convex portion 111 protruding from the second inner surface 109 and cuts the concave portion 221 in which the convex portion 111 is accommodated. The planar area 207b of the insert 201 has. Therefore, when the cutting insert 201 is erroneously mounted, the convex portion 111 of the insert pocket 103 and the curved surface region 207a of the cutting insert 201 come into contact with each other. In the present embodiment, the planar region 207b is configured by cutting out the curved region 207a. Therefore, in the cross section orthogonal to the central axis X, the distance from the central axis X to the planar region 207b is shorter than the distance from the central axis X to the curved surface region 207a.

  For this reason, the position of the cutting insert 201 is further shifted outward by the size of the convex portion 111. Therefore, it is difficult to screw the cutting insert 201 to the holder 101. As a result, since it is possible to notice early on the erroneous mounting of the cutting insert 201, it is possible to avoid a situation in which the cutting tool 1 is used in a state where the cutting insert 201 is erroneously mounted.

  The convex portion 111 of the insert pocket 103 may be in contact with the concave portion 221 of the cutting insert 201, but it is preferable that there is a gap between the entire surface of the convex portion 111 and the concave portion 221. That is, it is preferable that the convex portion 111 and the concave portion 221 are not in contact with each other. When the convex part 111 and the recessed part 221 are made to contact, since the convex part 111 is caught in the recessed part 221, it can suppress that the cutting insert 201 rotates. However, when the cutting insert 201 is reduced in size, the convex part 111 also becomes small.

  When the cutting insert 201 is attached to the holder 101 or when the cutting tool 1 is used, a force is applied from the cutting insert 201 to the holder 101. When the convex portion 111 is small, the convex portion 111 may be deformed or damaged by this force. Therefore, in order to keep the shape of the convex part 111 stable, it is preferable that the convex part 111 and the recessed part 221 are not contacting.

  In order to make the convex part 111 and the concave part 221 non-contact stably, it is preferable that the dimension of the convex part 111 is about 50 to 90% with respect to the dimension of the concave part 221. When it is 50% or more, the convex portion 111 is large enough to cause the displacement of the cutting insert 201. Further, when it is 90% or less, a sufficient gap is provided between the entire surface of the convex portion 111 and the concave portion 221.

  In addition, when the cutting insert 201 is erroneously attached to the insert pocket 103, in order to stably displace the cutting insert 201, it is preferable that the size of the convex portion 111 satisfies the following condition. Specifically, as shown in FIG. 11, in the cross section orthogonal to the central axis X of the through hole 211, the distance from the center of the through hole 211 to the center of the curved surface region 207a is L1, and the center of the through hole 211 is obtained. L2 is the distance from the center of the flat area 207b, D1 is the inner diameter of the through hole 211, D2 is the outer diameter of the screw 301, and Z is the size of the protrusion 111 protruding from the second inner side surface 109. In some cases, it is preferable that (D1-D2)-(L1-L2) <Z.

  As shown in FIG. 8, the above-mentioned size Z is an extension line of the bottom surface 105 and an extension line of the second inner side surface 109 in a cross section perpendicular to the bottom surface 105 and the second inner side surface 109 of the insert pocket 103. This means the width in the direction parallel to the bottom surface 105 from the point where the crossing points to the tip portion protruding from the second inner surface 109 of the convex portion 111.

When attaching the cutting insert 201 to the holder 101, the screw 301 is inserted into the through hole 211 of the cutting insert 201. At this time, in order to easily insert the screw 301 into the through hole 211, the inner diameter D1 of the through hole 211 and the outer diameter D2 of the screw 301 are not the same size, and the inner diameter D1 is set larger than the outer diameter D2. . When the difference between the magnitudes of D1 and D2 is ε, ε = D1−D2 (D2 <D1).

  When the distance from the center of the through hole 211 to the center of the curved area 207a is L1, and the distance from the center of the through hole 211 to the center of the plane area 207b is δ, δ = L1-L2 (L2 <L1). When the cutting insert 201 is downsized, the value of δ is reduced. When δ <ε, the cutting insert 201 may be screwed to the holder 101 even though the insert is erroneously attached to the holder 101.

  When the size Z of the convex portion 111 protruding from the second inner surface 109 is larger than ε−δ, which is the difference between δ and ε, that is, (D1−D2) − (L1−L2) = ε−δ < In the case of Z, the displacement of the cutting insert 201 is larger than the so-called “play” of the screw 301 with respect to the through hole 211. Therefore, erroneous mounting of the cutting insert 201 can be prevented more reliably.

  The recess 221 may have a shape that opens only on the outer surface 207 of the cutting insert 201. However, in the cutting insert 201 of the present embodiment, the recess 221 is formed from the planar region 207b to the lower surface 205 as shown in FIG. Is formed. That is, it opens to the outer side surface 207 and the lower surface 205 of the cutting insert 201. Further, the convex portion 111 is formed at the lower end of the second inner surface 109 so as to correspond to the shape of the concave portion 221. Specifically, the convex portion 111 does not protrude only from the second inner surface 109 but protrudes from the second inner surface 109 and the bottom surface 105 from the second inner surface 109 to the bottom surface 105.

  When the recess 221 has a shape that opens only on the outer surface 207 of the cutting insert 201, the cutting insert 201 must be attached to the insert pocket 103 from a direction orthogonal to the central axis X, but as described above, the recess 221 and the protrusion 111. Is configured, the cutting insert 201 can be easily attached to the insert pocket 103.

  The shape of the convex portion 111 is not particularly limited as long as the cutting insert 201 can be displaced in the direction away from the second inner surface 109 when the cutting insert 201 is erroneously attached to the holder 101. is not. In the present embodiment, a quadrangular prism shape having a distal end surface 111a that is separated from the second inner surface 109, an upper end surface 111b that is separated from the bottom surface 105, and a lateral surface that intersects the distal end surface 111a and the upper end surface 111b. It has become.

  In the convex portion 111 of the present embodiment, when the cutting insert 201 is erroneously attached to the holder 101, the tip surface 111 a comes into contact with the cutting insert 201, so that the cutting insert 201 moves away from the second inner surface 109. Misalignment.

  It is preferable that the tip of the convex portion 111 apart from the second inner surface 109 is constituted by a surface. It is preferable that the tip of the convex portion 111 constituted by this surface is in contact with the side surface of the cutting insert 201, particularly in line contact or surface contact. By contacting the side surface of the cutting insert 201, the cutting insert 201 can be stably displaced. Moreover, it can suppress that the stress from the cutting insert 201 concentrates on the specific location of the front-end | tip of the convex part 111 by carrying out surface contact of the convex part 111 with the cutting insert 201. FIG. Therefore, the durability of the convex portion 111 can be improved.

Moreover, when the convex part 111 has the front end surface 111a, it is preferable that the angle which the front end surface 111a and the bottom face 105 make is an acute angle or a right angle. This is because, when this angle is an obtuse angle, when the cutting insert 201 is attached to the insert pocket 103, the intersection of the curved region 207a and the lower surface 205 of the cutting insert 201 can easily ride on the tip surface 111a. In such a case, the misalignment of the cutting insert 201 is reduced, so that the possibility of erroneous mounting of the cutting insert 201 is increased.

The convex portion 111 is higher in height from the bottom surface 105 of the insert pocket 103 at the tip protruding from the second inner side surface 109 than the height from the bottom surface 105 of the insert pocket 103 at the boundary with the second inner side surface 109. It is preferable. That is, as shown in FIG. 8, the convex portion 111 has a height H 1 at the tip away from the second inner surface 109 rather than a height H 2 at the base close to the second inner surface 109. Larger is preferred.

  The height H1 is preferably about 10 to 50% with respect to the entire thickness of the cutting insert 1. When the above value is 10% or more, the effect of preventing erroneous mounting of the cutting insert 1 by the convex portion 111 can be stably obtained. Moreover, the area | region of the 2nd inner surface 109 can fully be ensured because it is 50% or less.

<Holder 101>
The holder 101 has a substantially rotating body shape centered on the rotation center axis Y. The holder 101 in the present embodiment has a substantially cylindrical shape in which the rotation center axis Y passes through the centers of both end faces. The holder 101 has a plurality of insert pockets 103 on the outer peripheral surface on the distal end side. The plurality of insert pockets 103 are provided at equal intervals. The insert pocket 103 is a part to which the cutting insert 201 is attached, and is open to the outer peripheral surface and the front end surface 111 a of the holder 101. The plurality of insert pockets 103 may be provided so as not to be equally spaced in order to suppress resonance.

  Each insert pocket 103 is fitted with a cutting insert 201 so that the upper cutting edge 209 protrudes from the tip of the holder 101. Specifically, the plurality of cutting inserts 201 are mounted such that the upper cutting edge 209 protrudes outward from the outer peripheral surface of the holder 101, that is, to the side of the holder 101.

  The insert pocket 103 includes a planar bottom surface 105 in contact with the lower surface 205 of the cutting insert 201, a curved first inner surface 107 in contact with the curved region 207a, and a planar second inner surface 109 in contact with the planar region 207b. Have. The bottom surface 105 faces the rotation direction of the rotation center axis Y and functions as a seating surface of the cutting insert 201. The first inner side surface 107 and the second inner side surface 109 are located in the direction in which the seating surfaces intersect. The first inner side surface 107 and the second inner side surface 109 function as restraint side surfaces that fix the position of the cutting insert 201 with respect to the insert pocket 103.

  The first inner side surface 107 has a curved surface shape, and comes into contact with the curved surface region 207 a of the cutting insert 201 when the cutting insert 201 is mounted in the insert pocket 103. The second inner side surface 109 has a planar shape, and comes into contact with the planar region 207 b of the cutting insert 201 when the cutting insert 201 is mounted in the insert pocket 103.

  The insert pocket 103 has a convex portion 111 protruding from the second inner surface 109. When the cutting insert 201 is correctly attached to the insert pocket 103, the convex portion 111 is accommodated in the concave portion 221 of the cutting insert 201 as shown in FIGS. On the other hand, when the cutting insert 201 is erroneously attached to the insert pocket 103, the convex portion 111 abuts on the curved surface region 207a of the cutting insert 201. Therefore, as shown in FIGS. Occurs. Therefore, since it becomes difficult to screw the cutting insert 201 to the holder 101, a situation in which the cutting tool 1 is used in a state where the cutting insert 201 is erroneously mounted can be avoided.

  As shown in FIG. 3, except for a region where the convex portion 111 is provided at a location where any two of the bottom surface 105, the first inner surface 107 and the second inner surface 109 of the insert pocket 103 intersect, A groove 113 is provided. When the cutting insert 201 is in contact with these portions, a large stress is likely to be concentrated from the cutting insert 201 when the cutting tool 1 is used. However, since the groove 113 is provided, concentration of stress is avoided, so that the holder can be avoided. The durability of 101 can be improved.

  A screw hole 115 is provided in the bottom surface 105 of the insert pocket 103. The screw hole 115 is located on an extension line on the lower surface 205 side of the through hole 211 when the cutting insert 201 is attached to the insert pocket 103. The screw 301 is inserted into the through hole 211 of the cutting insert 201 and the tip of the screw 301 is inserted into the screw hole 115 formed in the insert pocket 103 so that the screw portions are screwed together. 101 can be fixed.

  As the holder 101, 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 401. The cutting method in the present embodiment includes the following steps. That is,
(1) a step of rotating the cutting tool 1 represented by the above embodiment;
(2) a step of bringing the upper cutting edge 209 of the rotating cutting tool 1 into contact with the work material 401;
(3) separating the cutting tool 1 from the work material 401;
It has.

  More specifically, first, the cutting tool 1 is relatively moved closer to the workpiece 401 while being rotated around the rotation center axis Y. Next, as shown in FIGS. 12 and 13, the work material 401 is cut by bringing the upper cutting edge 209 of the cutting tool 1 into contact with the work material 401. Then, as shown in FIG. 14, the cutting tool 1 is relatively moved away from the work material 401.

  In the present embodiment, the workpiece 401 is fixed and the cutting tool 1 is brought closer. 12 and 13, the work material 401 is fixed and the cutting tool 1 is rotated. Further, in FIG. 14, the work material 401 is fixed and the cutting tool 1 is moved away. In the cutting process in the manufacturing method of the present embodiment, the work material 401 is fixed and the cutting tool 1 is moved in each step, but it is naturally not limited to such a form.

  For example, the work material 401 may be brought close to the cutting tool 1 in the step (1). Similarly, in the step (3), the work material 401 may be moved away from the cutting tool 1. In the case of continuing the cutting process, the state where the cutting tool 1 is rotated and the upper cutting blade 209 of the cutting insert 201 is brought into contact with a different part of the work material 401 may be repeated. When the used upper cutting edge 209 is worn, the cutting insert 201 may be rotated with respect to the central axis X of the through hole 211 to use an unused area in the upper cutting edge 209. Since the cutting insert 201 of the present embodiment includes eight plane regions 207 b, the cutting insert 201 is rotated by 45 ° with respect to the central axis X of the through hole 211, and the cutting insert 201 is mounted on the holder 101 again. You can do it.

  Typical examples of the material of the work material 401 include carbon steel, alloy steel, stainless steel, cast iron, or non-ferrous metal.

DESCRIPTION OF SYMBOLS 1 ... Cutting tool 101 ... Holder 103 ... Insert pocket 105 ... Bottom surface 107 ... 1st inner surface 109 ... 2nd inner surface 111 ... Convex part 113 ... Groove 115 ... Screw hole 201 ... Cutting insert 203 ... Upper surface 205 ... Lower surface 207 ... Outer surface 207a ... Curved area 207b ... Plane area 209 ... Upper cutting edge
211 ... through hole 213 ... land surface 215 ... rake surface 217 ... breaker surface 219 ... main surface 221 ... concave 301 ... screw 401 ... work material

Claims (6)

A holder having an insert pocket on the tip side;
An upper surface, a lower surface, an outer surface connected to each of the upper surface and the lower surface, a through-hole formed from the upper surface to the lower surface, and an upper cutting edge located at the intersection of the upper surface and the outer surface A cutting insert attached to the insert pocket so that the upper cutting edge protrudes from the tip of the holder;
A cutting tool provided with a screw inserted into the through hole and fixing the cutting insert to the holder,
The outer surface of the cutting insert has a curved region that is arcuate and a planar region that is linear in a cross section perpendicular to the central axis of the through-hole,
The insert pocket has a planar bottom surface in contact with the lower surface of the cutting insert, a curved first inner surface in contact with the curved region, and a planar second inner surface in contact with the planar region,
The insert pocket has a convex portion protruding from the second inner surface, and the planar region has a concave portion in which the convex portion is accommodated .
The convex portion is formed at the lower end of the second inner surface, and the concave portion is formed from the planar region to the lower surface of the cutting insert,
In a cross section perpendicular to the central axis of the through hole, the distance from the center of the through hole to the center of the curved region is L1, and the distance from the center of the through hole to the center of the planar region is L2, When the inner diameter of the through hole is D1, the outer diameter of the screw is D2, and the size of the protrusion protruding from the second inner surface is Z, (D1-D2)-(L1-L2) ) <Z cutting tool, characterized in that A holder having an insert pocket on the tip side;
An upper surface, a lower surface, an outer surface connected to each of the upper surface and the lower surface, a through-hole formed from the upper surface to the lower surface, and an upper cutting edge located at the intersection of the upper surface and the outer surface A cutting insert attached to the insert pocket so that the upper cutting edge protrudes from the tip of the holder;
A cutting tool provided with a screw inserted into the through hole and fixing the cutting insert to the holder,
The outer surface of the cutting insert has a curved region that is arcuate and a planar region that is linear in a cross section perpendicular to the central axis of the through-hole,
The insert pocket includes a flat bottom surface in contact with the lower surface of the cutting insert, a curved first inner surface in contact with the curved region, and a planar second inner surface in contact with the planar region.
Have
The insert pocket has a convex portion protruding from the second inner surface, and the planar region has a concave portion in which the convex portion is accommodated.
The height of the convex portion from the bottom surface of the insert pocket at the tip protruding from the second inner surface is larger than the height from the bottom surface of the insert pocket at the boundary with the second inner surface. Cutting tool that features. The cutting tool according to claim 2 , wherein the convex portion is formed at a lower end of the second inner side surface, and the concave portion is formed from the planar region to a lower surface of the cutting insert.   In a cross section perpendicular to the central axis of the through hole, the distance from the center of the through hole to the center of the curved region is L1, and the distance from the center of the through hole to the center of the planar region is L2, When the inner diameter of the through hole is D1, the outer diameter of the screw is D2, and the size of the protrusion protruding from the second inner surface is Z, (D1-D2)-(L1-L2) The cutting tool according to claim 3, wherein: <Z. The convex portion has a tip surface positioned away from the second inner surface,
The cutting insert according to any one of claims 1 to 4, wherein an angle formed by the tip surface and the bottom surface is an acute angle or a right angle. Rotating the cutting tool according to any one of claims 1 to 5,
Contacting the work piece with the upper 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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