JP2006281372A - Turning tools, insert holders and throwaway inserts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turning tool, a tip holder and a throw-away tip capable of increasing the applicable range without increasing the manufacturing cost.
A chip is attached to a chip holder. Insertion members 100 and 101 are provided between the chip holder 22 and the chip 23. The chip holder 22 has holder-side fitting recesses 112 and 113. The chip 23 has chip side insertion recesses 102 and 103. The fitting members 100 and 101 have holder fitting parts 121 and 122 and chip fitting parts 123 and 124. The holder fitting portions 121 and 122 are fitted into the holder side fitting concave portions 112 and 113. The chip insertion portions 123 and 124 are connected to the holder insertion portions 121 and 122, protrude from the chip holder 22 in a state where the holder insertion portions 121 and 122 are inserted into the holder side insertion recesses 112 and 113, and the chip side insertion. It is inserted into the recesses 102 and 103.
[Selection] Figure 1

Description

  The present invention relates to a turning tool for cutting a work material, and a tip holder and a throw-away tip constituting the turning tool.

  FIG. 13 is a side view showing a conventional end mill 1. An end mill 1 that is a cutting tool includes a tip holder 2 formed in a substantially cylindrical shape, and a throw-away tip 3 that is detachably attached to the tip holder 2. The throw-away tip 3 (hereinafter simply referred to as the tip 3) has cutting edges 11 and 12. The chip 3 is attached to the tip of the chip holder 2 with the cutting blades 11 and 12 protruding from the outer peripheral surface and the end surface of the chip holder 2. The cutting edge 11 protruding from the outer peripheral surface becomes the main cutting edge, and the cutting edge 12 protruding from the end face becomes the auxiliary cutting edge. The chip 3 is attached by being fastened to the chip holder 2 by, for example, a screw member.

  Such an end mill 1 can contact the workpiece while rotating around the axis L <b> 1 of the chip holder 2, and can cut the workpiece intermittently with the cutting blades 11 and 12. As a result, the work material can be cut into a predetermined shape. When the cutting edges 11 and 12 of the chip 3 are worn or broken, the cutting of the end mill 1 is performed by mounting a new chip 3 on the chip holder 2 instead of the chip 3 having the worn or broken cutting edges 11 and 12. Ability can be restored.

  In such a conventional technique, when the chip 3 is mounted on the chip holder 2, the chip 3 is simply fastened to the chip holder 2 by a screw member. If it is large, there is a problem that the chip 3 is displaced with respect to the chip holder 2. Techniques for solving this problem are disclosed in Patent Documents 1 to 3.

  In the technique disclosed in Patent Document 1, a concave groove is formed in a tool body that is a tip holder, and an engaging surface is formed in the concave groove. The cartridge, which is a throw-away tip, has a convex portion, and an engaging surface is formed on the convex portion. The engaging surface in the convex part of the cartridge engages with the engaging surface in the concave groove of the tool body. This prevents the cartridge from being displaced relative to the tool body.

  In the technique disclosed in Patent Document 2, a tip engaging portion is formed on a locator that is a tip holder. A convex portion is formed on the tip that is a throw-away tip. The tip is attached to the locator with the convex portion engaged with the tip engaging portion. This prevents the chip from being displaced relative to the locator.

  In the technique disclosed in Patent Document 3, a linear recess is formed on the bottom surface of a chip that is a throw-away chip. On the bottom surface of the chip seat of the tool body that is the chip holder, a chip base bottom surface convex portion that fits the linear concave portion on the chip bottom surface is formed. This prevents the displacement of the tip relative to the tool body.

JP 2004-24396 A Japanese Patent Laid-Open No. 11-815 Japanese Utility Model Publication No. 9-232

  In the conventional technique shown in FIG. 13, as described above, when the end mill 1 is rotated at a high speed or when the cutting resistance is large, the chip 3 is displaced with respect to the chip holder 2. Accordingly, when the end mill 1 is rotated at a high speed or when the cutting resistance is large, the end mill 1 cannot be applied, and there is a problem that the application range of the end mill 1 is small.

  In the technique disclosed in Patent Document 1, it is necessary to form a convex portion on the cartridge. It is difficult to form a convex portion on the cartridge as compared to forming a concave portion on the cartridge. In other words, when forming a recess, it is only necessary to perforate a recess such as a hole in the plane. However, when forming a projection, it is formed using a mold having a shape corresponding to the projection, It is necessary to cut the periphery so that only the part remains. Therefore, it is difficult to manufacture the cartridge, and there is a problem that the manufacturing cost of the cartridge is increased.

  In the technique disclosed in Patent Document 2, it is necessary to form a convex portion on the chip. Therefore, there is a problem similar to the technique disclosed in Patent Document 1.

  In the technique disclosed in Patent Document 3, a chip seat bottom surface convex portion needs to be formed on the chip seat bottom surface of the tool body. It is more difficult to form a convex portion on the bottom surface of the chip seat than to form a concave portion on the bottom surface of the chip seat. Therefore, it is difficult to manufacture the tool body, and there is a problem that the manufacturing cost of the tool body increases.

  An object of the present invention is to provide a turning tool, a tip holder, and a throw-away tip that can increase the application range without increasing the manufacturing cost.

The present invention includes a tip holder that is rotated about a rotation axis;
A throw-away tip attached to the tip holder in a state in which a cutting blade is formed and the cutting blade protrudes outward from the tip holder in the rotational radial direction of the tip holder;
A fitting member provided between the tip holder and the throw-away tip;
The chip holder has a holder-side fitting recess into which the fitting member is fitted,
The throw-away tip has a tip-side fitting recess into which the fitting member is fitted,
The insertion member is connected to the holder insertion portion and the holder insertion portion, and the holder insertion portion is inserted into the holder side insertion recess. A rolling tool characterized by having a tip insertion portion that protrudes and is fitted into a tip side insertion recess.

  Further, the present invention is characterized in that the fitting member has a rod shape, one side in the axial direction is the holder fitting portion, and the other side in the axial direction is the chip fitting portion.

  Further, in the present invention, the fitting member has a substantially columnar shape, and the inner surface of the holder-side fitting recess and the inner surface of the chip-side fitting recess have an inner circumferential surface corresponding to the outer circumferential surface of the fitting member. It is characterized by.

  In the invention, it is preferable that the fitting member has a substantially cylindrical shape and is arranged so that an axial direction of the fitting member is substantially perpendicular to the rotational radius direction.

Further, in the present invention, a female screw is formed in either one of the holder side insertion recess and the chip side insertion recess,
One of the holder insertion portion and the chip insertion portion is formed with a male screw that is screwed into the female screw.

Moreover, this invention is a chip holder used for the said tool for rolling.
Moreover, this invention is a throwaway tip characterized by being used for the said tool for rolling.

  According to the first aspect of the present invention, a chip is mounted on the chip holder to constitute a cutting tool. The chip holder is rotated around the rotation axis. The tip is formed with a cutting edge. This chip is mounted on the chip holder in a state where the cutting blade protrudes from the chip holder outward in the rotational radius direction of the chip holder.

  Such a rolling tool can contact the workpiece while rotating around the rotation axis, and can intermittently cut the workpiece with a cutting blade. As a result, the work material can be cut into a predetermined shape. When the cutting blade is worn or broken, the cutting ability of the cutting tool can be recovered by mounting a new tip on the tip holder instead of the tip worn or broken.

  A fitting member is provided between the chip holder and the chip. The fitting member has a holder fitting part and a chip fitting part. The holder fitting portion is fitted into the holder-side fitting recess of the chip holder. The chip insertion portion is connected to the holder insertion portion, protrudes from the chip holder in a state in which the holder insertion portion is inserted into the holder side insertion recess, and is inserted into the chip side insertion recess of the chip.

  By providing such a fitting member, even when the cutting tool is rotated at a high speed or when the cutting resistance is large, the position of the chip relative to the chip holder can be prevented. Therefore, even when the turning tool is rotated at high speed or the cutting resistance is large, the turning tool can be applied, and the application range of the turning tool can be increased.

  The fitting member is formed separately from the chip holder and the chip. The chip holder only needs to be formed with a holder-side insertion recess, and does not need to be provided with a protrusion for preventing displacement. The chip only needs to be provided with a chip-side insertion concave portion, and does not need to have a convex portion for preventing displacement. Forming the concave portion is easier than forming the convex portion. Therefore, compared to the techniques disclosed in Patent Documents 1 to 3, the manufacturing of the chip holder and the chip can be facilitated and the manufacturing cost can be reduced.

  In such this invention, the application range of the tool for rolling can be enlarged, without raising manufacturing cost.

  Depending on whether or not a fitting member is provided between the chip holder and the chip, it is possible to realize proper use according to the application. When cutting conditions are severe, it is possible to reliably prevent the positional deviation of the chip with respect to the chip holder by providing a fitting member between the chip holder and the chip. When cutting conditions are not severe, it is not necessary to provide a fitting member between the chip holder and the chip. As a result, it is possible to reduce the labor required for mounting the fitting member during the mounting operation, and to facilitate the mounting of the chip to the chip holder. In such a case, a chip having no recess is provided. Since it can also be used, versatility is improved. On the other hand, in the techniques disclosed in Patent Documents 1 to 3, a dedicated chip that engages with the concave portion or the convex portion is required, and therefore lacks versatility.

  According to the second aspect of the present invention, when the fitting member is rod-shaped, one side in the axial direction is the holder fitting portion, and the other side in the axial direction is the tip fitting portion, the cutting resistance is large. Even so, it is possible to more reliably prevent the displacement of the chip relative to the chip holder.

  According to the third aspect of the present invention, the fitting member has a substantially cylindrical shape, and the inner surface of the holder-side fitting recess and the inner surface of the chip-side fitting recess correspond to the outer circumference of the fitting member. Since it has a surface (cylindrical inner peripheral surface), stress concentration can be suppressed as compared with the case where each inner surface has another shape, for example, a rectangular tube surface. Therefore, breakage of the chip holder and the chip can be prevented.

  In addition, it is easier to form each inner surface in a cylindrical shape than to form each inner surface in another shape. Therefore, the manufacturing of the chip holder and the chip can be further facilitated, and the manufacturing cost can be further reduced.

  According to the fourth aspect of the present invention, since the axial direction of the fitting member is arranged so as to be substantially perpendicular to the rotational radius direction of the chip holder, the fitting member is located outside the rotational radius direction with respect to the chip holder. Displacement is prevented. Therefore, it is possible to prevent a problem that the tip is displaced outward in the rotational radial direction with respect to the tip holder due to the centrifugal force due to the rotation.

  According to the fifth aspect of the present invention, the female screw is formed in one of the holder side insertion recess and the chip side insertion recess. A male screw that is screwed into the female screw is formed in one of the holder fitting portion and the chip fitting portion. Thus, the fitting member can be screwed into either the holder-side fitting recess or the chip-side fitting recess. Therefore, during the mounting operation of mounting the chip on the chip holder, the fitting member can be dropped by screwing the fitting member into one of the holder-side fitting recess and the chip-side fitting recess in advance. This can prevent the chip from being attached to the chip holder.

  According to the sixth aspect of the present invention, by providing the fitting member between the chip holder and the chip, it is possible to prevent the chip from being displaced with respect to the chip holder, and to increase the application range of the tool for cutting. can do. The chip holder only needs to be formed with a holder-side insertion recess, and does not need to be formed with a protrusion for preventing misalignment, thereby facilitating the manufacture of the chip holder and reducing the manufacturing cost. it can. In such this invention, the application range of the tool for rolling can be enlarged, without raising manufacturing cost.

  According to the seventh aspect of the present invention, since the fitting member is provided between the chip holder and the chip, it is possible to prevent the chip from being displaced with respect to the chip holder, and to increase the application range of the tool for cutting. can do. The chip only needs to be provided with a chip-side insertion concave portion, and does not need to be formed with a convex portion for preventing displacement, so that the chip can be easily manufactured and the manufacturing cost can be reduced. In such this invention, the application range of the tool for rolling can be enlarged, without raising manufacturing cost.

  FIG. 1 is an enlarged side view showing a part of an end mill 20 according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view showing a part of the end mill 20. FIG. 3 is a side view showing the end mill 20. The end mill 20 that is a cutting tool includes a throw-away tip 23 in which cutting edges 30 and 31 are formed, a tip holder 22 to which the throw-away tip 23 is detachably attached, a throw-away tip 23 and a tip holder 22. And includes a pair of fitting members 100 and 101 that are rod-shaped, specifically, substantially columnar.

  In the present embodiment, the chip holder 22 is configured so that a large number, specifically, three throw-away chips 23 (hereinafter simply referred to as chips 23) can be mounted. The end mill 20 is configured by mounting each chip 23 on a chip holder 22.

  The chip holder 22 is formed in a substantially cylindrical shape. A held portion 28 held by a milling machine is formed at the base end portion of the chip holder 22. A mounting portion 24 to which the chip 23 is mounted is formed at the tip portion of the chip holder 22. The chip holder 22 is rotated around a rotation axis that forms a straight line common to the axis L1 of the chip holder 22 (hereinafter simply referred to as the axis L1).

  Hereinafter, of the axial direction X of the chip holder 22, the direction from the proximal end portion to the distal end portion of the chip holder 22 is referred to as an axial direction one X 1, and the direction from the distal end portion of the chip holder 22 to the proximal end portion is the other axial direction. This will be referred to as X2. Of the radial direction Y, which is the rotational radial direction of the chip holder 22, the direction approaching the axis L1 is referred to as a radially inward Y1, and the direction away from the axis L1 is referred to as a radially outward Y2.

  The chip 23 is mounted on the mounting portion 24 of the chip holder 22 with the cutting blades 30 and 31 protruding from the outer peripheral surface 32 and the end surface 33 of the chip holder 22. In other words, the chip 23 is mounted on the mounting portion 24 of the chip holder 22 with the cutting blades 30 and 31 protruding from the chip holder 22 in the radially outward direction Y2 and the axial direction X1.

  The milling machine includes a movement drive unit that relatively moves and drives the clamped work material and the held end mill 20, and a rotation drive unit that drives the held end mill 20 around the axis L1. The end mill 20 can contact the workpiece while rotating around the axis L <b> 1, and can intermittently cut the workpiece with the cutting blades 30 and 31. As a result, the work material can be cut into a predetermined shape. For example, the end mill 20 can be used to perform grooving and stepping on the work material. When the cutting edges 30 and 31 of the chip 23 are worn or broken, the cutting of the end mill 20 is performed by attaching a new chip 23 to the chip holder 22 instead of the chip 23 having the worn or broken cutting blades 30 and 31. Ability can be restored.

  FIG. 4 is a perspective view showing the upper surface portion 87 of the chip 23. FIG. 5 is a perspective view showing the bottom surface 39 of the chip 23. FIG. 6 is a bottom view showing the chip 23. The chip 23 is generally formed in a plate shape. When the chip 23 is projected onto a projection plane perpendicular to the thickness direction A of the chip 23, the chip 23 has a substantially parallelogram shape, and one of the two pairs of opposite sides is opposite to the other. Longer than. Hereinafter, a direction in which one opposite side of the chip 23 extends in the projection plane is referred to as a longitudinal direction B. A direction perpendicular to the longitudinal direction B in the projection plane is referred to as a width direction C.

  The chip 23 has a through hole forming portion in which a through hole 50 penetrating in the thickness direction A is formed. The inner surface of the through hole forming portion facing the through hole 50 is cylindrical. The axis of the through hole 50 extends in the thickness direction A. The through hole 50 is disposed at the center position in the longitudinal direction B and the width direction C. The through hole 50 is a hole for fixing the chip 23 to the chip holder 22.

  In the present embodiment, the tip 23 has a 180-degree rotationally symmetric shape with respect to the reference axis L2 with the axis of the through hole 50 as the reference axis L2, in other words, a 2-fold rotationally symmetric shape. Therefore, when the chip 23 is viewed from an arbitrary direction, the chip 23 has the same shape in the state rotated 180 degrees around the reference axis L2 and the state before the rotation.

  Cutting edges 30 and 31 are formed on the upper surface portion 87 on the one A1 side in the thickness direction of the chip 23. Specifically, the first cutting edge 30 is formed on the edge of the pair of long side portions 60 and 61 facing each other in the upper surface portion 87. A second cutting edge 31 is formed on each of the edges of the pair of short side portions 62 and 63 facing each other in the upper surface portion 87. Each of the cutting blades 30 and 31 is an intersecting ridge where the upper surface and the side surface of the chip 23 intersect. When the chip 23 is mounted on the chip holder 22, either one of the two first cutting edges 30 becomes a main cutting edge protruding from the outer peripheral surface 32 of the chip holder 22. Any one of them becomes a secondary cutting edge protruding from the end face 33 of the chip holder 22.

  Hereinafter, in the longitudinal direction B, the direction from the second short side portion 63 toward the first short side portion 62 is defined as one longitudinal direction B1, and the direction from the first short side portion 62 toward the second short side portion 63 is defined as the longitudinal direction. The other is B2. Of the width direction C, the direction from the second long side portion 61 toward the first long side portion 60 is defined as one width direction C1, and the direction from the first long side portion 60 toward the second long side portion 61 is defined as the other width direction C2. And

  The bottom surface portion 39 on the other side A2 in the thickness direction of the chip 23 has a bottom surface 86 formed flat. The bottom surface 39 has a pair of chip side fitting recesses 102 and 103. In the chip-side fitting recesses 102 and 103, chip-side fitting recesses 104 and 105 into which the fitting members 100 and 101 are fitted are formed. The inner surfaces of the chip-side fitting recesses 102 and 103 facing the chip-side fitting recesses 104 and 105 are cylindrical, and have inner circumferential surfaces corresponding to the outer circumferential surfaces of the fitting members 100 and 101. .

  The chip side insertion recesses 104 and 105 are arranged so as to be aligned in the longitudinal direction B. One chip side insertion recess 104 is arranged at the center position in the width direction C and on the one side B1 in the longitudinal direction with respect to the through hole 50. The other chip side insertion recess 105 is disposed at the center position in the width direction C and on the other side B <b> 2 in the longitudinal direction with respect to the through hole 50. The axis L3, L4 of each chip side insertion recess 104, 105 is parallel to the reference axis L2, and the distance from the reference axis L2 is the same.

  FIG. 7 is an enlarged perspective view showing the chip holder 22. Hereinafter, of the circumferential direction R around the axis L1, the rotation direction of the end mill 20 is referred to as one circumferential direction R1, and the opposite direction of the rotation direction of the end mill 20 is referred to as the other circumferential direction R2.

  A groove 27 that is recessed from the outer peripheral surface 32 and the end surface 33 of the chip holder 22 is formed at the tip of the chip holder 22. The groove 27 is a space including a throw-away tip accommodating space 26 and a chip accommodating space 25 adjacent to the throw-away tip accommodating space 26. The throw-away chip accommodating space 26 is a space in which almost the entire chip 23 is accommodated. The chip storage space 25 is a space for temporarily storing chips scraped by the chip 23.

  Of the groove 27, the region on the one circumferential side R <b> 1 side becomes the chip accommodating space 25, and the region on the other circumferential direction R <b> 2 side becomes the throw-away tip accommodating space 26. In the present embodiment, the chip accommodating space 25 extends in the other axial direction X2 from the throw-away tip accommodating space 26 and is opened outward. The chips separated from the work material by the cutting blades 30 and 31 of the chip 23 are angularly displaced around the axis L <b> 1 in the state of being accommodated in the chip accommodating space 25 after being accommodated in the chip accommodating space 25. Escape from the opening of the chip accommodating space 25.

  The tip holder 22 has a throw-away tip accommodating space forming part that defines the throw-away tip accommodating space 26 and a chip accommodating space forming part that defines the chip accommodating space 25.

  The mounting portion 24, which is a throwaway tip accommodating space forming portion, has a seating surface 40 as a surface of the other circumferential surface R2 with respect to the groove 27, and a circumferential surface R1 adjacent to the seating surface 40 with respect to the seating surface 40. It has two side surfaces 41 and 42 which stand upright.

  The seating surface 40 is bent from the end surface 33 of the chip holder 22 and extends in the other axial direction X2, and is bent from the outer peripheral surface 32 of the chip holder 22 and extends inward in the radial direction Y1. The seating surface 40 is inclined to the other circumferential direction R2 as it proceeds to the other axial direction X2 of the chip holder 22. As a result, an axial rake in the positive direction, in other words, a rake angle in the positive axial direction can be imparted to the main cutting edge.

  The first side surface 41, which is one of the two side surfaces 41, 42, is adjacent to the edge of the seating surface 40 on the radially inner side Y <b> 1 side, and is erected in the circumferential direction one R <b> 1 with respect to the seating surface 40. The second side surface 42, which is the other of the two side surfaces 41, 42, is adjacent to the edge on the other side X <b> 2 in the axial direction of the seating surface 40, and stands upright on the seating surface 40 in one circumferential direction R <b> 1. Each of the side surfaces 41 and 42 is, of the first cutting blade 30 and the two second cutting blades 31 that are not the main cutting blades of the two first cutting blades 30 when the chip 23 is mounted on the chip holder 22. The second cutting edge 31 that does not become the secondary cutting edge is partially retracted so as not to contact the side surfaces 41 and 42.

  The seating surface portion 111 on which the seating surface 40 of the mounting portion 24 is formed has a screw hole forming portion in which a screw hole 29 that is recessed from the seating surface 40 in the other circumferential direction R2 is formed. The inner surface of the screw hole forming portion that faces the screw hole 29 is cylindrical. The axis L7 of the screw hole 29 is substantially perpendicular to the radial direction Y. A female screw is formed in the screw hole forming portion. The screw hole 29 is a recess for fixing the chip 23 to the chip holder 22.

  The seating surface portion 111 has a pair of holder-side fitting recesses 112 and 113. In the holder-side fitting recesses 112 and 113, holder-side fitting recesses 114 and 115 into which the fitting members 100 and 101 are fitted are formed. The inner surfaces of the holder-side insertion recesses 114 and 115 facing the holder-side insertion recesses 114 and 115 are cylindrical, and have inner peripheral surfaces corresponding to the outer peripheral surfaces of the insertion members 100 and 101. Yes.

  The holder-side insertion recesses 114 and 115 are arranged so as to be aligned in the axial direction X. One holder-side fitting recess 114 has the same position in the radial direction X as the screw hole 29, and is disposed on the one X1 side in the axial direction with respect to the screw hole 29. The other holder-side insertion recess 115 has the same position in the radial direction X as that of the screw hole 29, and is disposed on the other axial direction X 2 side with respect to the screw hole 29. The axis lines L5 and L6 of the holder-side fitting recesses 114 and 115 are parallel to the axis line L7 of the screw hole 29, and the distance from the axis line L7 of the screw hole 29 is the same. The distance between the axis L5, L6 of each holder side insertion recess 114, 115 and the axis L7 of the screw hole 29 is the distance between the axis L3, L4 of each chip side insertion recess 104, 105 from the reference axis L2. It is the same as the distance.

  The chip accommodating space forming portion is adjacent to the first side surface 41 and extends in one circumferential direction R1 and is connected to the outer peripheral surface 32 of the chip holder 22 and the second side surface 42 is adjacent to the second side surface 42. A second wall surface 44 extending from the side surface 42 to the other axial direction X2 and a third wall surface 45 adjacent to the second wall surface 44 and extending from the second wall surface 44 to the circumferential direction one R1 and continuing to the outer peripheral surface 32 of the chip holder 22. Have.

  The groove 27 is an area surrounded by the seating surface 40, the side surfaces 41, 42 and the wall surfaces 43, 44, 45. The groove 27 has a substantially fan-shaped cross section perpendicular to the axis L1. A plurality of grooves 27 as described above are formed in the tip end portion of the chip holder 22 at intervals in the circumferential direction R. A plurality of convex portions 46, which are portions between two grooves 27 adjacent in the circumferential direction R, are formed at intervals in the circumferential direction R. Each protrusion 46 protrudes from the radially inner portion 47 to the radially outward Y2. Each convex portion 46 has the mounting portion 24.

  FIG. 8 is a cross-sectional view taken along section line S8-S8 in FIG. Description will be made with reference to FIGS. The end mill 20 is configured by mounting each chip 23 on each mounting portion 24 of the chip holder 22.

  In the mounted state in which the chip 23 is mounted on the mounting unit 24, the bottom surface 86 of the chip 23 abuts on the seating surface 40 of the mounting unit 24. The reference axis L2 that is the axis of the through hole 50 and the axis L7 of the screw hole 29 coincide. The axis lines L3 and L4 of the chip-side insertion recesses 104 and 105 and the axis lines L5 and L6 of the holder-side insertion recesses 114 and 115 coincide with each other.

  Most of the chip 23 is accommodated in the groove 27. The thickness direction A of the chip 23 is substantially parallel to the circumferential direction R of the chip holder 22. The longitudinal direction B of the chip 23 is substantially parallel to the axial direction X of the chip holder 22. The width direction C of the chip 23 is substantially parallel to the radial direction Y of the chip holder 22.

  One or the other first cutting edge 30 of the chip 23 projects from the outer peripheral surface 32 of the chip holder 22 radially outward Y2 with a predetermined projection amount. The one or other first cutting edge 30 is a main cutting edge. One or the other second cutting edge 31 of the chip 23 protrudes from the end surface 33 of the chip holder 22 in one axial direction X1 with a predetermined protrusion amount. The one or other second cutting edge 31 is a secondary cutting edge.

  The tip 23 is fastened to the seating surface portion 111 of the mounting portion 24 by a screw member 129. The screw member 129 has a screw part 130 and a head part 131. The screw portion 130 is formed with a male screw that is screwed into a female screw formed in the screw hole forming portion of the seating surface portion 111. The head 131 has a larger diameter than the screw portion 130 and is continuous with one end portion of the screw portion 130. The screw member 129 is screwed into the screw hole forming portion in a state where the screw portion 130 is inserted through the through hole 50 of the tip 23 and the tip 23 is sandwiched between the head portion 131 and the seating surface portion 111.

  A pair of fitting members 100 and 101 are provided between the chip 23 and the mounting portion 24. The fitting members 100 and 101 are columnar members. The outer diameter D1 of the fitting members 100 and 101 is smaller than the outer diameter D2 of the screw member 129. The fitting members 100 and 101 are arranged such that the axial direction of the fitting members 100 and 101 is substantially perpendicular to the radial direction Y.

  The fitting members 100 and 101 include holder fitting portions 121 and 122 that are portions on one side in the axial direction, and chip fitting portions 123 and 124 that are portions on the other side in the axial direction. The holder fitting portions 121 and 122 are fitted into the holder side fitting recesses 114 and 115. The chip insertion portions 123, 124 are connected to the holder insertion portions 121, 122, and from the seating surface 40 of the chip holder 22 in a state where the holder insertion portions 121, 122 are inserted into the holder side insertion recesses 114, 115. It protrudes in one circumferential direction R1, and is fitted into the chip side fitting recesses 104 and 105. The longitudinal dimension W1 of the holder insertion parts 121, 122 is larger than the longitudinal dimension W2 of the chip insertion parts 123, 124.

  The holder side insertion recesses 112 and 113 have holder side contact surfaces that contact the holder insertion portions 121 and 122 from the radially outer side Y2. The chip side insertion recesses 102 and 103 have chip side contact surfaces that contact the chip insertion portions 123 and 124 from the radially inner Y1.

  FIG. 9 is a front view showing the chip 23. FIG. 10 is a right side view showing the chip 23. FIG. 11 is a plan view showing the chip 23. This will be described with reference to FIGS. The first cutting edge 30 is formed over substantially the entire region in the longitudinal direction B of the long side portions 60 and 61. The second cutting edge 31 is formed in a part of the short side portions 62 and 63.

  In the present embodiment, when the chip 23 is projected onto a projection plane perpendicular to the thickness direction A of the chip 23, the first direction in which each first cutting edge 30 extends on the projection plane coincides with the longitudinal direction B, The second direction in which each second cutting edge 31 extends on the projection plane coincides with the width direction C.

  One second cutting edge 31A formed on the first short side portion 62 is connected to the end on the one side B1 side in the longitudinal direction of one first cutting edge 30A formed on the first long side portion 60, and in the width direction. The other extends to C2. The other second cutting edge 31B formed in the second short side portion 63 is connected to the end of the other first cutting edge 30B formed in the second long side portion 61 in the longitudinal direction on the other B2 side, in the width direction. On the other hand, it extends to C1. The first cutting edge 30 and the second cutting edge 31 are connected via a corner portion 68. The corner portion 68 is formed with a corner cutting edge extending along an arc having a predetermined radius of curvature. The corner cutting edge connects the first cutting edge 30 and the second cutting edge 31.

  Of the short side portions 62 and 63, the non-cutting edge forming edge 69 where the second cutting edge 31 is not formed is the edge of the long side portions 60 and 61 on the opposite side of the second cutting edge 31 from the second cutting edge 31. It continues to. The non-cutting edge forming edge 69 is inclined so as to retract in the longitudinal direction B with respect to the second cutting edge 31 as it proceeds from the second cutting edge 31 to the edges of the long side portions 60 and 61. That is, one non-cutting edge forming edge 69A formed in the first short side portion 62 advances from the one second cutting edge 31A to the other in the width direction C2 in the other longitudinal direction B2, and the other first cutting edge. It continues to 30B. The other non-cutting edge forming edge 69B formed in the second short side portion 63 advances in the longitudinal direction one B1 from the other second cutting edge 31B in the width direction one C1, and the one first cutting edge 30A. It continues to. These non-cutting edge forming edges 69A and 69B extend in parallel to each other.

  The second cutting edge 31 extends in the width direction C along a plane perpendicular to the thickness direction A. The non-cutting edge forming edge 69 is inclined toward the other side A2 in the thickness direction as it advances from the second cutting edge 31 toward the first cutting edge 30. That is, one non-cutting edge forming edge 69A proceeds to the other thickness direction A2 as it proceeds to the other width direction C2. The other non-cutting edge forming edge 69B advances to the other side A2 in the thickness direction as it goes to one side C1 in the width direction. When the chip 23 is projected onto the projection plane perpendicular to the longitudinal direction B, each second cutting edge 31 is arranged in the thickness direction one A1, and each first cutting edge 30 is arranged outside the width direction C. The

  One first cutting edge 30A is formed such that one side B1 in the longitudinal direction is shifted to one side A1 in the thickness direction than the other side B2 in the longitudinal direction. The other first cutting edge 30B is formed such that the other side B2 side in the longitudinal direction is shifted to the one side A1 in the thickness direction than the one side B1 in the longitudinal direction. In the present embodiment, each first cutting edge 30 is smoothly inclined toward the other side A <b> 2 in the thickness direction as it advances from the corner portion 68 toward the non-cutting edge forming edge 69. That is, one first cutting edge 30A is inclined in the other thickness direction A2 as it advances in the other longitudinal direction B2. The other first cutting edge 30B is inclined in the thickness direction other A2 as it advances in the longitudinal direction one B1.

  Of the edges that go around the upper surface portion 87 of the chip 23, the corner portion 68 that connects the first cutting edge 30 and the second cutting edge 31 is located in the most thickness direction one side A <b> 1, and the first cutting edge 30 is not cut off. The connecting portion 67 to which the blade forming edge 69 is connected is located in the othermost thickness direction A2 most. In the present embodiment, the upper surface of the chip 23 generally increases in thickness as it advances from the linear part connecting the two connecting parts 67 located at diagonal positions across the reference axis L2 to each corner part 68. Inclined toward one direction A1. In other words, when the chip 23 is cut by a cut surface passing through each corner portion 68 and the reference axis L2, the upper surface is V-shaped in the thickness direction one side A1 from the vicinity of the reference axis L2 toward each corner portion 68. Stand up in shape.

  On the upper surface portion 87 of each of the long side portions 60 and 61, a first rake face that is inclined in the thickness direction other side A2 as the distance from the first cutting edge 30 in the width direction C is formed. On the side surfaces in the width direction of the long side portions 60 and 61, first flank surfaces that are immersed in the width direction C are formed as they are separated from the first cutting edge 30 in the other thickness direction A2.

  As each short side portion 62, 63 is separated from the second cutting edge 31 in the longitudinal direction B, a second rake face inclined in the other thickness direction A2 is formed. On the side surfaces in the longitudinal direction of the respective short side portions 62 and 63, second flank surfaces that are immersed in the longitudinal direction B are formed as they are separated from the second cutting edge 31 in the other thickness direction A2.

  As for each width direction surface of each long side part 60 and 61, the part of a longitudinal direction both sides is formed flat, and the longitudinal direction center part protrudes in the width direction C compared with the part of a longitudinal direction both sides. The portions on both sides in the longitudinal direction serve as first contact surfaces 51 for the chip 23 to contact the chip holder 22. The surface in the longitudinal direction of each short side portion 62, 63 is a second contact surface 52 for the tip 23 to come into contact with the tip holder 22, the portion extending from the non-cutting edge forming edge 69 to the other thickness direction A 2.

  In this way, the chip 23 has a corner portion of an intersecting ridge formed by the side surface and the upper surface of the main body that forms a substantially parallelogram in a plan view of the chip 23 from one thickness direction A1 to the other thickness direction A2. A corner cutting edge is formed at two corners opposite to each other diagonally, and a first cutting edge 30 for forming a main cutting edge on both sides of the corner cutting edge, and a secondary cutting edge, a so-called blade, are formed. And a second cutting edge 31 for the purpose. A portion of the upper surface along the first cutting edge 30 is provided with a rake face with a certain rake angle. The first cutting edge 30 is inclined so as to gradually move away from a plane that includes the corner cutting edge and is perpendicular to the reference axis L2 as it is separated from the corner cutting edge in the longitudinal direction B, and is formed in a twisted shape having a so-called twist angle θ. .

  According to the present embodiment as described above, when the fitting members 100 and 101 are provided between the chip holder 22 and the chip 23, the end mill 20 is rotated at a high speed or the cutting resistance is large. Even so, it is possible to prevent the displacement of the chip 23 relative to the chip holder 22. Therefore, even when the end mill 20 is rotated at a high speed or when the cutting resistance is large, the end mill 20 can be applied and the application range of the end mill 20 can be increased.

  The fitting members 100 and 101 are formed separately from the chip holder 22 and the chip 23. Only the holder-side insertion recesses 114 and 115 are formed in the chip holder 22, and it is not necessary to form a convex portion for preventing displacement. The chip 23 only needs to be provided with chip-side insertion recesses 104 and 105, and does not need to be provided with a convex portion for preventing displacement. Forming the recess is easier than forming the convex portion. Therefore, as compared with the techniques disclosed in Patent Documents 1 to 3, the manufacturing of the chip holder 22 and the chip 23 can be facilitated and the manufacturing cost can be reduced.

  In this embodiment, the applicable range of the end mill 20 can be increased without increasing the manufacturing cost.

  Since the fitting members 100 and 101 are rod-shaped, the part on one side in the axial direction is the holder fitting part 121 and 122, and the part on the other side in the axial direction is the chip fitting part 123 and 124. Even when the cutting resistance is large, the positional displacement of the chip 23 with respect to the chip holder 22 can be prevented more reliably.

  Since the holder-side contact surfaces of the holder-side insertion recesses 112 and 113 come into contact with the holder insertion portions 121 and 122 of the insertion members 100 and 101 from the radially outer side Y2, the insertion members 100 and 101 are chips. Displacement in the radially outward direction Y2 with respect to the holder 22 is prevented. Further, the chip-side contact surfaces of the chip-side insertion recesses 102 and 103 come into contact with the chip insertion portions 123 and 124 of the insertion members 100 and 101 from the radially inner Y1, so that the chip 23 is inserted into the insertion member 100. , 101 is prevented from being displaced radially outward Y2. Therefore, it is possible to prevent the problem that the tip 23 is displaced radially outward Y2 with respect to the tip holder 22 due to the centrifugal force caused by the rotation.

  The fitting members 100 and 101 are substantially cylindrical, and the inner surfaces of the holder-side fitting recesses 112 and 113 and the inner surfaces of the chip-side fitting recesses 102 and 103 are the inner circumferences corresponding to the outer peripheral surfaces of the fitting members 100 and 101. Since it has a surface (cylindrical inner peripheral surface), stress concentration can be suppressed as compared with the case where each inner surface has another shape, for example, a rectangular tube surface. Therefore, damage to the chip holder 22 and the chip 23 can be prevented.

  In addition, it is easier to form each inner surface in a cylindrical shape than to form each inner surface in another shape. Therefore, the manufacturing of the chip holder 22 and the chip 23 can be further facilitated, and the manufacturing cost can be further reduced.

  Since the fitting members 100 and 101 are disposed so that the axial direction of the fitting members 100 and 101 is substantially perpendicular to the radial direction Y of the chip holder 22, the fitting members 100 and 101 are located with respect to the chip holder 22. Thus, displacement in the radially outward direction Y2 is prevented. Therefore, it is possible to prevent the problem that the tip 23 is displaced radially outward Y2 with respect to the tip holder 22 due to the centrifugal force caused by the rotation.

  By providing the fitting members 100 and 101 between the chip holder 22 and the chip 23, the force applied to the screw member 129 during cutting can be reduced. Thereby, the through-hole formation part of the chip | tip 23 can be made small, and the chip | tip 23 can be reduced in thickness.

  Since the outer diameter D1 of the fitting members 100 and 101 is smaller than the outer diameter D2 of the screw member 129, the strength of the chip holder 22 and the chip 23 is reduced due to the provision of the fitting members 100 and 101. Can be suppressed as much as possible.

  It is desired that the chip holder 22 be used repeatedly by replacing the chip 23. Therefore, it is desirable that the life of the chip holder 22 be as long as possible as compared with the chip 23. In the present embodiment, the longitudinal dimension W1 of the holder insertion parts 121 and 122 is larger than the longitudinal dimension W2 of the chip insertion parts 123 and 124. As a result, during cutting, the stress generated in the holder-side insertion recesses 112 and 113 due to the load acting on the holder-side insertion recesses 112 and 113 from the holder insertion portions 121 and 122 is changed from the chip insertion portions 123 and 124 to the chip side. It becomes smaller than the stress which generate | occur | produces in the chip | tip insertion recessed parts 102 and 103 by the load which acts on the insertion recessed parts 112 and 113. FIG. Therefore, damage to the holder-side fitting recesses 112 and 113 can be prevented, and the life of the chip holder 22 can be extended.

  Depending on whether or not the fitting members 100 and 101 are provided between the chip holder 22 and the chip 23, it is possible to realize proper use according to the application.

  When the cutting conditions are severe, for example, when the end mill 20 is rotated at a high speed or when the cutting resistance is large, the insert members 100 and 101 are provided between the tip holder 22 and the tip 23 to thereby insert the tip 23 with respect to the tip holder 22. Can be reliably prevented. As an example of the case where cutting conditions are severe, there is a case where a workpiece made of aluminum is cut at high speed.

  When the cutting conditions are not severe, for example, when the end mill 20 is rotated at a low speed and the cutting resistance is small, the fitting members 100 and 101 may not be provided between the chip holder 22 and the chip 23. As a result, it is possible to reduce the effort required to attach the fitting members 100 and 101 during the mounting operation, and to facilitate the mounting of the chip 23 to the chip holder 22, and in such a case, there is a recess. Since a chip that has not been used can also be used, versatility is improved. On the other hand, in the techniques disclosed in Patent Documents 1 to 3, a dedicated chip that engages with the concave portion or the convex portion is required, and therefore lacks versatility.

  Since the chip holder 22 is not formed with a convex portion for preventing displacement, even if the chip 23 is not provided with the chip-side insertion recesses 104 and 105, the insertion members 100 and 101 are not provided. The chip 23 can be mounted on the chip holder 22. Since the chip 23 is not formed with a convex portion for preventing misalignment, even if the chip holder 22 is not provided with the holder-side insertion recesses 114 and 115, the insertion members 100 and 101 are not provided. A chip 23 can be mounted on the chip holder 22. Thus, the versatility of the chip holder 22 and the chip 23 can be improved.

  Since the tip 23 has two first cutting edges 30A and 30B, when one of the first cutting edges 30A is used as the main cutting edge, the tip 23 is angularly displaced by 180 degrees around the reference axis L2. The other first cutting edge 30B can be the main cutting edge 86. Therefore, when one of the first cutting edges 30A is worn or broken, the other first cutting edge 30B can be made the main cutting edge 86 by angularly displacing the tip 23 about the reference axis L2. In addition, the lifetime of one chip 23 can be extended.

  FIG. 12 is a cross-sectional view showing a part of an end mill 220 according to another embodiment of the present invention. Since the end mill 220 of the present embodiment is similar to the end mill 20 of the above-described embodiment, the corresponding portions are denoted by the same reference numerals, and description of common points is omitted.

  Female screws are formed in the holder-side fitting recesses 112 and 113, and male screws that are screwed into the female screws are formed in the holder fitting portions 121 and 122. Thus, the fitting members 100 and 101 can be screwed into the holder-side fitting recesses 112 and 113.

  According to the present embodiment as described above, the same effects as those of the above-described embodiment can be obtained, and the holder-side fitting recess 112, during the mounting operation of mounting the chip 23 on the chip holder 22, When the fitting members 100 and 101 are screwed to 113 in advance, the fitting members 100 and 101 can be prevented from dropping, and the attachment of the chip 23 to the chip holder 22 can be facilitated.

  Further, according to the present embodiment, since the fitting members 100, 101 are screwed and fixed to the holder-side fitting recesses 112, 113, even if vibration occurs during cutting, the holder-side fitting recess 112, 113 The fitting members 100 and 101 do not collide with 113. Therefore, it is possible to prevent the problem that the holder-side fitting recesses 112 and 113 are damaged by the impact force caused by the collision, and the life of the chip holder 22 can be extended.

  Each of the embodiments described above is merely an example of the present invention, and the configuration can be changed within the scope of the present invention. In each of the above-described embodiments, the end mill has been described as the turning tool. However, the same effect can be obtained even with other turning tools having no secondary cutting edge, for example, a milling turning tool. be able to. In each of the above-described embodiments, the first cutting edge 30 is smoothly inclined in the thickness direction A as it advances in the longitudinal direction B. However, the first cutting edge 30 is formed in a stepped shape, and in the thickness direction other A2 as it advances in the longitudinal direction B. It may shift.

  In still another embodiment of the present invention, a female screw may be formed in the chip-side fitting recesses 102 and 103, and a male screw that engages with the female screw may be formed in the chip-inserting portions 123 and 124. Thus, the fitting members 100 and 101 can be screwed into the chip side fitting recesses 102 and 103. Therefore, by inserting the fitting members 100 and 101 into the chip-side fitting recesses 102 and 103 in advance during the mounting operation, the fitting members 100 and 101 can be prevented from dropping, and the chip holder 22 can be prevented. It is possible to facilitate the mounting of the chip 23 on.

  The number of fitting members provided between the chip holder 22 and the chip 23 is not limited to two, and may be one, or may be three or more. Even in this case, the same effects as those of the above-described embodiments can be obtained. The tip 23 of each of the above embodiments is an example of a throw-away tip, and the throw-away tip attached to the tip holder 22 is not limited to the tip 23.

It is a side view which expands and shows a part of end mill 20 of one embodiment of the present invention. 3 is an enlarged perspective view showing a part of the end mill 20. FIG. 2 is a side view showing an end mill 20. FIG. 4 is a perspective view showing an upper surface portion 87 of a chip 23. FIG. 4 is a perspective view showing a bottom surface portion 39 of the chip 23. FIG. 5 is a bottom view showing the chip 23. FIG. It is a perspective view which expands and shows the chip holder 22. FIG. It is sectional drawing seen from cut surface line S8-S8 of FIG. 3 is a front view showing a chip 23. FIG. 4 is a right side view showing a chip 23. FIG. 4 is a plan view showing a chip 23. FIG. It is sectional drawing which shows a part of end mill 220 of other form of implementation of this invention. It is a side view which shows the end mill 1 of a prior art.

Explanation of symbols

20, 220 End mill 22 Tip holder 23 Throw-away tip 30, 31 Cutting edge 100, 101 Inserting member 102, 103 Tip side insertion recess 104, 105 Tip side insertion recess 112, 113 Holder side insertion recess 114, 115 Holder side insertion recess 121, 122 Holder insertion portion 123, 124 Chip insertion portion

Claims (7)

A tip holder that is rotated about a rotation axis;
A throw-away tip attached to the tip holder in a state in which a cutting blade is formed and the cutting blade protrudes outward from the tip holder in the rotational radial direction of the tip holder;
A fitting member provided between the tip holder and the throw-away tip;
The chip holder has a holder-side fitting recess into which the fitting member is fitted,
The throw-away tip has a tip-side fitting recess into which the fitting member is fitted,
The insertion member is connected to the holder insertion portion and the holder insertion portion, and the holder insertion portion is inserted into the holder side insertion recess. A tool for milling, characterized by having a chip insertion portion that protrudes and is fitted into the chip side insertion recess.   The rolling tool according to claim 1, wherein the fitting member has a rod shape, one side in the axial direction is the holder fitting portion, and the other side in the axial direction is the chip fitting portion.   The fitting member has a substantially cylindrical shape, and the inner surface of the holder-side fitting recess and the inner surface of the chip-side fitting recess have an inner circumferential surface corresponding to the outer circumferential surface of the fitting member. The turning tool according to claim 1 or 2.   The said fitting member is substantially cylindrical shape, and is arrange | positioned so that the axial direction of the said fitting member may become substantially perpendicular | vertical with the said rotation radial direction. The tool for turning described in 1. Either one of the holder side insertion recess and the chip side insertion recess is formed with a female screw,
The rolling tool according to any one of claims 1 to 4, wherein a male screw that is screwed into the female screw is formed in one of the holder fitting part and the chip fitting part. .   A tip holder used in the rolling tool according to any one of claims 1 to 5.   A throw-away tip used in the rolling tool according to any one of claims 1 to 5.

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