JP6426405B2 - Milling tool and method of manufacturing cut product using the same - Google Patents

Description

  The present invention relates to a milling tool and a method of manufacturing a machined product using the same.

  As a milling tool used for milling of a work material such as metal, a tool disclosed in Patent Document 1 or 2 is known. The tool disclosed in Patent Document 1 has a first component, and a second component provided on the tip side of the first component and coaxially connected to the first component. ing. The first and second components are each fitted with a milling tool. The first component includes, at a portion connected to the second component, a concave-shaped connecting element extending from the center side toward the outer peripheral side, and the second component includes the connecting element described above and It has a convex-shaped connecting element to be engaged.

  In the tool disclosed in Patent Document 1, the first and second components are each provided with a cutting insert. However, in recent years, a small-diameter milling tool is required, and in order to cope with the reduction in tool diameter, a tool is proposed in which the entire element on the tip side is a cutting insert like the milling tool disclosed in Patent Document 2. It is done.

  The milling tool disclosed in Patent Document 2 includes a shaft-like holder having a longitudinal axis, and a cutting plate (cutting insert) attached to the front surface of the holder. The front surface of the holder is provided with a groove extending from the screw hole coaxial with the longitudinal axis toward the outer peripheral surface, and the rear end surface of the cutting plate is directed from the central hole located at the center toward the outer peripheral surface An extending rib is provided. The engagement of the groove and the rib causes transmission of torque or positioning in the rotational direction of the shaft.

Japanese Patent Publication No. 7-506300 Japanese Patent Publication No. 2005-530622

  In the tool disclosed in Patent Document 1, the first component has a concave connection element. However, when the diameter of the tool decreases, the thickness from the connecting element to the outer periphery of the first component decreases. Therefore, the durability of the first component may be insufficient. Further, in the milling tool disclosed in Patent Document 2, since only the groove of the holder and the rib of the cutting plate are engaged, there is a possibility that the centering may be insufficient when attaching the cutting insert to the holder There is.

  The present invention has been made in view of the above problems, and provides a milling tool having high durability and good mounting accuracy.

A milling tool according to an aspect of the present invention includes a rod-shaped holder that rotates around a rotation axis, a plurality of cutting edges provided at a tip, and an outer circumferential surface from the plurality of cutting edges toward the rear side. And a cutting insert mounted on the tip side of the holder. The cutting insert is provided on a first convex portion that is positioned on the rotation axis and protrudes rearward from a rear side surface, and the plurality of the first convex portions on the outer circumferential surface from the first convex portion. And a plurality of first recesses extending respectively toward the area located between the chip pockets. Further, the holder has a second concave portion fitted to the first convex portion and a plurality of second convex portions respectively fitted to the plurality of first concave portions. Further, the plurality of first recesses are separated from the outer circumferential surface.

  In the cutting insert of the above aspect, centering can be favorably performed because the first convex portion and the second concave portion are fitted, and the second convex portion and the first concave portion Because of the fitting, the positioning in the rotational direction of the rotary shaft can be favorably performed. Further, since the second convex portion is provided in the holder and the first concave portion is provided in the cutting insert, it is possible to prevent the formation of a portion which is excessively thin on the holder. Therefore, the durability of the milling tool can be enhanced.

It is a side view showing a milling tool of a 1st embodiment of the present invention. It is a perspective view of the cutting insert in the milling tool shown in FIG. It is a top view of the cutting insert shown in FIG. It is a side view from the A1 direction of the cutting insert shown in FIG. It is a side view from the A2 direction of the cutting insert shown in FIG. It is the perspective view which expanded the front-end | tip part of the holder in the milling cutter shown in FIG. It is a perspective view of the cutting insert in the milling cutter of the 2nd Embodiment of this invention. It is a top view of the cutting insert shown in FIG. It is a side view from the A3 direction of the cutting insert shown in FIG. It is a side view from the A4 direction of the cutting insert shown in FIG. It is the schematic which shows 1 process of the manufacturing method of the cutting material of one Embodiment of this invention. It is the schematic which shows 1 process of the manufacturing method of the cutting material of one Embodiment of this invention. It is the schematic which shows 1 process of the manufacturing method of the cutting material of one Embodiment of this invention.

  Hereinafter, the milling tool of each embodiment of the present invention is explained in detail using a drawing. However, each drawing referred to in the following is a simplified illustration of only the main members necessary to explain the present invention among the constituent members of the embodiment for the convenience of explanation. Thus, the milling tool of the present invention may comprise any component not shown in the referenced figures. Further, the dimensions of the members in the respective drawings do not faithfully represent the dimensions of the actual constituent members, the dimensional ratio of the respective members, and the like.

First Embodiment
First, the milling cutter 101 according to the first embodiment will be described in detail with reference to the drawings.

  The milling cutter 101 according to the first embodiment, as shown in FIG. 1, includes a holder 1 and a cutting insert 3 (hereinafter also referred to simply as the insert 3). The holder 1 has a rotation axis (rotation center axis) X, and has a rod-like configuration extending along the rotation axis X. The holder 1 rotates in the direction of the arrow Y around the rotation axis X around the rotation axis X at the time of cutting.

As the holder 1, steel, cast iron, aluminum alloy or the like can be used. In the milling tool 101 of the present embodiment, a steel with high toughness is used among these members. The size of the holder 1 is appropriately set according to the size of the work material. For example, the length in the direction along the rotation axis X is set to about 60 to 150 mm. Further, the width in the direction orthogonal to the rotation axis X is set to about 6 to 50 mm.

  As shown in FIGS. 2 to 5, the insert 3 has a disk shape extending along the rotation axis X, and is attached to the tip of the holder 1. The insert 3 has a plurality of cutting edges 5 provided on the front side surface 9 located on the tip end side of the milling tool 1 and a plurality of cuttings provided on the outer peripheral surface 13 from the plurality of cutting edges 5 toward the rear side surface 11 And a pocket 7. The length in the direction along the rotation axis X of the insert 3 is set to, for example, about 6 to 15 mm. Further, the width in the direction orthogonal to the rotation axis X is set to about 6 to 32 mm.

  The plurality of cutting edges 5 are respectively located on the front side surface 9 side of the insert 3 and extend from the center side of the front side surface 9 toward the outer peripheral side and continue to the front cutting edge 5a. It has an outer peripheral cutting edge 5 b located on the outer peripheral side of 3 and extending from the side of the front side surface 9 to the side of the rear side surface 11.

  The chip pockets 7 are provided on the outer circumferential surface 13 from the plurality of cutting edges 5 toward the rear side surface 11 of the insert 3. Specifically, since the cutting edge 5 has the front cutting edge 5a and the outer peripheral cutting edge 5b, a part of the outer peripheral surface 13 is cut out so as to open to the front side surface 9 and the rear side surface 11 in the insert It had a structure that The chip pocket 7 may be provided on the outer peripheral surface 13 so as to be open to the front side surface 9 and the rear side surface 11, and therefore, the chip pocket 7 does not necessarily have to be formed by cutting out the outer peripheral surface 13 at the time of manufacturing the insert 3.

  The chip pocket 7 has a function of scooping chips generated by the cutting blade 5 at the time of cutting and delivering the chips to the holder 1 side. Therefore, the region of the inner wall surface located inside the cutting edge 5 along the cutting edge 5 in the chip pocket 7 functions as a rake face of the cutting edge. Further, in the present embodiment, the chip pocket 7 is configured to be inclined rearward in the rotational direction of the rotation axis X as it goes from the side of the front side 9 of the insert 3 to the side of the rear side 11.

  The insert 3 in the present embodiment has a through hole 15 penetrating from the front side surface 9 to the rear side surface 11. The through hole 15 is provided for inserting a screw (not shown) when the insert 3 is screwed to the holder 1. The insert 3 is fixed to the holder 1 by inserting a screw into the through hole 15 of the insert 3 and inserting the tip of the screw into a screw hole (not shown) formed in the holder 1 and screwing the screw portions together. Be done.

  Examples of the material of the insert 3 include cemented carbide and cermet. As a composition of the cemented carbide, for example, WC-Co produced by adding a powder of cobalt (Co) to tungsten carbide (WC) and sintering it, WC-WC-WC-Co with addition of titanium carbide (TiC) There is WC-TiC-TaC-Co in which tantalum carbide (TaC) is added to TiC-Co or WC-TiC-Co. Further, cermet is a sintered composite material in which a ceramic component is compounded with a metal, and specific examples thereof include a titanium compound mainly composed of titanium carbide (TiC) or titanium nitride (TiN).

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

The insert 3 in the present embodiment has one first protrusion 17 and a plurality of first recesses 19. The first convex portion 17 is positioned on the rotation axis X and protrudes rearward from the rear side surface 11. Since the insert 3 in the present embodiment has the through hole 15 from the front side surface 9 to the rear side surface 11, the first convex portion 17 is positioned so as to surround the through hole 15.

  The plurality of first recesses 19 in the insert 3 are provided on the rear side surface 11 and extend from the first protrusion 17 toward the outer circumferential surface 13. Therefore, the end on the side of the rotation axis X in the first recess 19 is continuous with the first protrusion 17. Further, the end on the outer peripheral side of the first recess 19 does not reach the outer peripheral surface 13, and the first recess 19 is separated from the outer peripheral surface 13.

  Further, the plurality of first recesses 19 respectively extend toward the region located between the plurality of chip pockets 7 on the outer peripheral surface 13 of the insert 3. Therefore, the length of the first recess 19 in the direction orthogonal to the rotation axis X can be secured long. Further, since the first recess 19 can be positioned to a position closer to the outer periphery of the insert 3, the insert 3 can be stably held by the holder 1.

  The plurality of first recesses 19 are respectively located apart from the chip pocket 7. Therefore, the durability of the insert 3 can be enhanced. In addition, the possibility of chips entering the first recess 19 can be reduced.

  As shown in FIG. 6, the holder 1 in the present embodiment has a plurality of second protrusions 21 and one second recess 23. The second concave portion 23 is a portion fitted to the first convex portion 17. Therefore, the second concave portion 23 is provided on the front end surface of the holder 1 and is configured to be recessed from the front end side toward the rear end side. Further, since the first convex portion 17 is positioned so as to surround the through hole 15, a screw hole in which a screw for fixing the above-mentioned insert 3 to the holder 1 is inserted into the bottom of the second concave portion 23. (Not shown) is provided.

  The plurality of second protrusions 21 in the holder 1 are portions that respectively fit into the first recesses 19. Therefore, the plurality of second protrusions 21 are provided on the tip end surface of the holder 1 and extend from the second recess 23 toward the outer periphery. In the present embodiment, the end of the second protrusion 21 on the side of the rotation axis X is continuous with the second recess 23. Further, the end on the outer peripheral side of the second convex portion 21 does not reach the outer periphery of the holder 1, and the second convex portion 21 is separated from the outer periphery of the holder 1.

  On the outer periphery of the holder 1, a plurality of groove portions 25 continuous with a plurality of chip pockets 7 in the insert 3 are provided. The groove portion 25 spirally extends around the rotation axis X from the front end surface of the holder 1 toward the rear end side, and has a function of discharging the chips generated by the cutting blade 5 to the outside.

  The milling tool 101 according to the present embodiment has high durability because it has the first convex portion 17, the first concave portion 19, the second convex portion 21 and the second concave portion 23 described above, respectively. And, it has become a good one of the mounting accuracy.

  Specifically, since the first convex portion 17 and the second concave portion 23 are fitted, centering can be favorably performed, and the second convex portion 21 and the first concave portion 19 Can be favorably positioned in the rotational direction of the rotation axis X.

  At this time, in the portion where the insert 3 and the holder 1 are fitted, not only the unevenness is formed, but the insert 3 has the first convex portion 17 and the first concave portion 19. 1 has a second protrusion 21 and a second recess 23.

Therefore, even when the insert 3 is miniaturized, the first convex portion 17 of the insert 3 and the second concave portion 23 of the holder 1 are easily fitted with each other, which facilitates securing the length in the direction along the rotation axis X Because of this, centering can be performed well. Further, since the second convex portion 21 is provided in the holder 1 and the second concave portion 23 is provided in the insert 3, it is possible to prevent the holder 1 from being formed with an excessively thin portion. . Therefore, the durability of the milling tool 101 can be enhanced.

  The first convex portion 17 in the insert 3 has a circular shape whose outer periphery in a cross section orthogonal to the rotation axis X is centered on the rotation axis X. Since the rotation axis X is centered as described above, centering can be favorably performed. Further, the inner peripheral surface of the second concave portion 23 of the holder 1 fitted to the first convex portion 17 has a cylindrical shape so as to correspond to the shape of the outer periphery of the first convex portion 17. The outer periphery of the first convex portion 17 described above may have a polygonal shape, but a portion which is excessively thin is formed in the thickness between the outer peripheral surface of the holder 1 and the inner peripheral surface of the second recess 23 It is preferable that it has a circular shape in order to suppress

  On the other hand, in the case where the outer periphery of the first convex portion 17 described above has a polygonal shape, the first convex portion 17 and the second concave portion 23 are in contact with each other in a flat surface. Transmission of torque to 3 can be made good. The outer periphery of the first convex portion 17 is preferably in the shape of a regular polygon such as a regular square, a regular hexagon or a regular octagon. At this time, it is preferable that the center of the regular polygon be located on the rotation axis X in order to suppress the thickness variation between the outer peripheral surface of the holder 1 and the inner peripheral surface of the second recess 23.

  Further, the first convex portion 17 in the insert 3 has a shape in which the diameter in the direction orthogonal to the rotation axis X decreases with distance from the rear side surface 11 of the insert 3. Further, the second recess 23 in the holder 1 has a shape in which the diameter in the direction orthogonal to the rotation axis X decreases as going from the front end surface of the holder 1 to the rear end side. Thereby, when attaching the insert 3 to the holder 1, centering can be easily performed.

  The plurality of first recesses 19 in the insert 3 have a bottom surface and side surfaces located on the front side and the rear side in the rotational direction of the rotation axis X. At this time, at least a part of the front side surface in the rotational direction of the rotation axis X has a flat surface shape. When cutting is performed, the cutting resistance transmitted from the work material to the cutting blade 5 is easily transmitted to the holder 1 via the front side surface in the rotational direction of the rotation axis X in the first recess 19. Therefore, the insert 3 can be stably held by the holder 1 because at least a part of the side surface has a flat surface shape. This enables cutting with high accuracy.

  In addition, although it is preferable that it is said structure, several 1st recessed part 19 is not limited to such a structure. For example, in a cross section along the rotation direction of the rotation axis X, the first recess 19 may have an arc shape without having a side surface and a bottom surface.

  Moreover, although the plurality of first recesses 19 respectively extend toward the region located between the plurality of chip pockets 7 in the outer peripheral surface 13 of the insert 3, at this time, the plurality of first recesses 19 are It is separated from the adjacent chip pocket 7 on the front side in the rotational direction of the rotational axis X than the adjacent chip pocket 7 on the rear side in the rotational direction of the rotational axis X. That is, as shown in FIG. 3, the distance L1 between the first recess 19 and the chip pocket 7 adjacent on the front side in the rotational direction of the rotation axis X with respect to the first recess 19 is the first Is longer than the distance L2 between the recess 19 and the chip pocket 7 adjacent to the first recess 19 on the rear side in the rotational direction of the rotation axis X.

The cutting force generated by the cutting edge 5 located in the adjacent chip pocket 7 on the front side in the rotational direction of the rotation axis X is easily transmitted to the plurality of first recesses 19. The plurality of first recesses 19 are provided at the above positions, respectively, so that the insert 3 can be inserted between the chip pocket 7 and the first recess 19 adjacent to each other on the front side in the rotational direction of the rotation axis X. A large thickness can be secured. Therefore, the durability of the insert 3 can be further improved.

  When viewed in plan from the direction along the rotation axis X, the plurality of first recesses 19 are provided at positions rotationally symmetric about the rotation axis X. In the case where the insert 3 has the above-described configuration, it is possible to reduce variation in cutting resistance applied to each of the plurality of first recesses 19.

  Further, the length of the first convex portion 17 which protrudes from the rear side surface 11 of the insert 3 is larger than the depth from the rear side surface 11 of the insert 3 in the first concave portion 19. Thereby, when attaching the insert 3 to the holder 1, centering can be performed with high accuracy. As a length which protrudes from the back side 11 of the insert 3 in the 1st convex part 17, it can set, for example to about 3-15 mm. Moreover, as a depth from the rear side 11 of the insert 3 in the 1st recessed part 19, it can set to about 2-7 mm, for example.

Second Embodiment
Next, the milling cutter 101 according to the second embodiment will be described in detail with reference to the drawings.

  The milling cutter 101 of the second embodiment includes the holder 1 and the insert 3 in the same manner as the milling cutter 101 of the first embodiment. The milling tool 101 of this embodiment is different from the milling tool 101 of the first embodiment in the configuration of the first concave portion 19 of the insert 3 and the second convex portion 21 of the holder 1. The configuration is the same as that of the milling tool 101 of the first embodiment, except for the configuration of the milling tool 101 of the present embodiment, so the detailed description will be omitted.

  In the milling tool 101 of the first embodiment, the first recess 19 of the insert 3 is away from the outer peripheral surface 13 of the insert 3, and the second protrusion 21 of the holder 1 is away from the outer periphery of the holder 1. ing. However, in the milling tool 101 of the present embodiment, as shown in FIGS. 7 to 10, the end on the outer peripheral side of the first recess 19 of the insert 3 reaches the outer peripheral surface 13 of the insert 3, The recess 19 is open to the outer peripheral surface 13. Further, the outer peripheral end of the second convex portion 21 of the holder 1 reaches the outer periphery of the holder 1.

  In the milling tool 101 of the first embodiment, since the thickness between the chip pockets 7 in the insert 3 in the direction along the rotation direction of the rotation axis X can be secured large, the durability of the insert 3 is further enhanced. be able to. On the other hand, in the milling tool 101 of the present embodiment, the lengths of the first recess 19 and the second protrusion 21 in the direction orthogonal to the rotation axis X can be long. Therefore, the transmission of torque from the holder 1 to the insert 3 can be made better. Further, since the first recess 19 can be positioned up to the outer periphery of the insert 3, the insert 3 can be stably held by the holder 1.

<Method of manufacturing cut product>
Next, a method of manufacturing a machined product according to an embodiment of the present invention will be described using the drawings.

The machined product is manufactured by cutting the work material 201. The method of manufacturing a machined product in the present embodiment includes the following steps. That is,
(1) a step of rotating the milling tool 1 represented by the above embodiment;
(2) bringing the cutting edge of the rotating milling tool 1 into contact with the work material 201;
(3) releasing the milling tool 1 from the work material 201;
Is equipped.

  More specifically, first, as shown in FIG. 11, the milling tool 1 is rotated around the rotation axis X, and the milling tool 1 is moved in the Z1 direction to be relatively close to the work material 201. Next, as shown in FIG. 12, the cutting blade 5 of the milling tool 1 is brought into contact with the workpiece 201, and the milling tool 1 is moved in the Z2 direction to cut the workpiece 201. Then, as shown in FIG. 13, the milling cutter 1 is moved in the Z3 direction so as to be relatively away from the workpiece 201.

  In the present embodiment, the work material 201 is fixed and the milling tool 1 fixed around the rotation axis X is brought close to the work material 201 while being rotated. Further, in FIG. 12, the material to be cut 201 is cut by bringing the cutting edge 5 of the rotating insert into contact with the material to be cut 201. Further, in FIG. 13, the milling tool 1 is moved away from the workpiece 201 while being rotated.

  In the cutting process in the manufacturing method of this embodiment, the milling tool 1 is brought into contact with the work material 201 by moving the milling tool 1 in each process, or the milling tool 1 is separated from the work material 201 However, of course, it is not limited to such a form.

  For example, in the step (1), the workpiece 201 may be brought close to the milling tool 1. Similarly, in the step (3), the work material 201 may be moved away from the milling tool 1. When cutting is to be continued, the step of keeping the milling tool 1 rotated and keeping the cutting blade 5 of the insert 3 in contact with different parts of the workpiece 201 may be repeated.

  In addition, as a representative example of the material of the work material 201, carbon steel, alloy steel, stainless steel, cast iron, nonferrous metal etc. are mentioned.

101 ··· Milling tool 1 · · · Holder 3 · · · Cutting insert (insert)
5 ... cutting edge 5a ... front cutting edge 5b ... outer peripheral cutting edge 7 ... chip pocket 9 ... front side surface 11 ... rear side surface 13 ... outer peripheral surface 15 ... through hole 17 ··· First convex portion 19 ··· First concave portion 21 ··· Second convex portion 23 ··· Second concave portion 25 ··· Groove portion 201 ··· Work material

Claims (8)

A rod-shaped holder which rotates around the rotation axis,
A cutting insert mounted on the front end side of the holder, having a plurality of cutting blades provided on the front end side and a plurality of chip pockets respectively provided on the outer peripheral surface from the plurality of cutting blades toward the rear side surface; A milling tool with
The cutting insert is provided on a first convex portion that is positioned on the rotation axis and protrudes rearward from a rear side surface, and the plurality of the first convex portions on the outer circumferential surface from the first convex portion. And a plurality of first recesses extending respectively toward the area located between the chip pockets;
The holder has a second recess fitted to the first protrusion, and a plurality of second protrusions fitted to the plurality of first recesses, respectively .
The milling tool according to claim 1, wherein the plurality of first recesses are separated from the outer circumferential surface .   The milling cutter according to claim 1, wherein the first convex portion has a shape in which a diameter in a direction orthogonal to the rotation axis decreases with distance from the rear side surface.   The plurality of first recesses are separated from the adjacent chip pocket on the front side in the rotational direction of the rotation shaft than the adjacent chip pocket on the rear side in the rotational direction of the rotation shaft. Milling tool according to claim 1 or 2.   The plurality of first recesses are provided at positions rotationally symmetric about the rotation axis when viewed in a plan view from the direction along the rotation axis. Milling tool according to any one.   The length which protrudes from said back side of said 1st convex part is larger than the depth from said back side of said 1st crevice, The statement is given to any 1 paragraph of Claims 1-4 characterized by the above-mentioned. Milling tools.   The holder is characterized in that it is continuous with a plurality of chip pockets in the cutting insert, and has a plurality of grooves which extend helically around the rotation axis from the front end to the rear end, respectively. The milling tool according to any one of Items 1 to 5. The cutting insert further includes a through hole penetrating from the tip side to the first convex portion,
The milling tool according to any one of claims 1 to 6, wherein the cutting insert is fixed to the holder by a screw inserted into the through hole. Rotating the milling tool according to any one of claims 1 to 7 around a rotation axis;
Bringing the cutting blade of the rotating milling tool into contact with the work material;
And moving the milling tool away from the workpiece.