JP5899905B2 - Carbon film-coated drill and manufacturing method thereof - Google Patents

Description

  The present invention relates to a carbon film-coated drill capable of sharply machining a work material and a method for manufacturing the same.

In a diamond-coated cutting tool in which the surface of the cutting edge is coated with a diamond film, conventionally, for example, a substantially arc portion formed on the cutting edge is ground, and the angle of the approximately arc portion is partially set to 40 ° or less. A device provided with a chamfer has been proposed (see Patent Document 1). Further, there has also been proposed a method in which the substantially arc portion is ground and the clearance angle is smaller than the original angle (see Patent Document 2).
In addition, in this specification, a cutting edge shows the area | region which match | combined the cutting edge of a cutting tool, a part of rake face which touched the cutting edge, and a part of flank which touched the cutting edge.

  As a polishing method for the diamond film-coated cutting tool, a laser polishing method described in Patent Document 3 has been proposed. In this laser polishing method, the focus of the laser is scanned (moved) on the surface of the diamond coating, and at the same time, the diamond coating itself is moved. In this way, the projections formed on the surface of the diamond coating are removed by relatively moving both the focal point of the laser and the diamond coating. Moreover, in the manufacturing method of the processing tool described in patent document 4, the processing tool is processed by irradiating a laser beam having a wavelength of 266 nm perpendicularly to the diamond coating.

Japanese Patent No. 3477182 Japanese Patent No. 3477183 Japanese Patent No. 3096943 JP 2009-6436 A

The following problems remain in the conventional technology.
First, when the cutting edge is formed by grinding, the diamond is harder than the grindstone, so that the shape of the grindstone changes during the machining. As a result, it becomes difficult to perform shape processing intended with high accuracy.
Secondly, in the method of scanning laser processing while relatively moving the laser and the diamond film together, it is necessary to move the workpiece (workpiece) according to the shape of the workpiece. This complicates laser focus and diamond film position control.
Thirdly, in the processing method in which laser light is irradiated perpendicularly to the diamond film, the shape after processing easily reflects the undulating shape of the film before processing. Therefore, the film before processing needs to be formed as a uniform diamond film. Therefore, high-precision processing becomes difficult.
Fourth, when a diamond coating is formed on a cutting edge such as a cutting edge of a drill, the coating is formed on the cutting edge depending on the thickness of the diamond coating, so that it is difficult to process the cutting edge. For this reason, conventionally, it has been difficult to produce a drill coated with a diamond coating and having sharp edges.

  The present invention has been made in view of the above-described problems, and provides a carbon film-coated drill coated with a carbon film such as a diamond film having a sharper edge than conventional ones, and is capable of processing the drill with high accuracy. It is an object of the present invention to provide a manufacturing method that can be manufactured.

  The present invention employs the following configuration in order to solve the above problems. That is, the carbon film-coated drill according to the first aspect of the present invention includes a tool base having a base cutting edge, and a base scooping surface and a base relief surface that are adjacent to each other across the base cutting edge, the base cutting edge, and the base A rake face and a carbon film formed on the base flank face, wherein the carbon film is directed toward the tool base in a region on the base rake face and a region on the base flank face. A concave surface on the rake face side and a concave surface on the flank face side are respectively formed, and the concave surface on the rake face side and the concave surface on the flank face side intersect with each other on the base blade edge to form a carbon film blade edge on the carbon film. The angle between the concave surface on the rake face side and the concave surface on the flank face side is smaller than the angle formed by the base rake face and the base flank face.

In this carbon film-coated drill, a concave surface on the rake face side and a concave surface on the flank face side that are recessed toward the tool base are formed in the carbon film in the region on the base rake surface and in the region on the base flank surface, respectively. . Furthermore, the concave surface on the rake face side and the concave surface on the flank face side intersect on the base blade edge to form a carbon film blade edge on the carbon film. Furthermore, the angle at which the concave surface on the rake face side and the concave surface on the flank side intersect is smaller than the angle formed by the base rake surface and the base flank surface. By having the above configuration, the carbon film-coated drill has a sharper edge than before.
In other words, the carbon film surface of the portion including the carbon film edge (cutting edge) is scooped and made concave with respect to the rake face and the extended surface of the flank face, so that the carbon film of the carbon film edge is sharply formed. As a result, in the carbon film-coated drill, a sharper edge than a chamfer formed by a conventional method can be obtained.
In the carbon film-coated drill, the carbon film may be a diamond film.
In the carbon film-coated drill, a cross section of the concave surface on the rake face side and the concave surface on the flank face side by a surface orthogonal to the carbon film cutting edge may be a concave curve shape .
Also, in the carbon film-coated drill, the concave surface of the concave and the flank side of the rake face side, the width of the carbon film cutting edge and perpendicular to the direction along the respective surfaces was within the range of 2000μm from 10μm May be.
In the carbon film-coated drill, a depth of the concave surface on the rake face side and a concave surface on the flank face side may be in a range of 2 μm to 15 μm.
In the carbon film-coated drill, a width of the concave surface on the rake face side and a concave surface on the flank face side in a direction perpendicular to the carbon film cutting edge is in a range of 10 μm to 2000 μm, and the rake face side The depth of the concave surface and the concave surface on the flank side may be in the range of 2 μm to 15 μm.

The method for producing a carbon film-coated drill according to the second aspect of the present invention is a method for producing the carbon film-coated drill according to the present invention, wherein the substrate blade edge and the substrate rake face adjacent to each other with the substrate blade edge interposed therebetween. And a base film preparing step of preparing a tool base having a base flank, a carbon film forming step of forming a carbon film on the base rake face, the base flank and the base cutting edge of the tool base, and the carbon The film is irradiated with a laser beam to process the carbon film formed in the region on the base rake face and in the region on the base flank face, on the rake face side and the flank face side, respectively. Forming a concave surface and a concave surface on the flank side, wherein the rake surface side and the concave surface on the flank side intersect on the base blade edge to form a carbon film blade edge, and the laser For processing And the light intensity distribution in the beam cross section of the laser beam shows a Gaussian distribution, and the laser beam is applied from the front of the base blade edge to the carbon film on the rake face side or the flank face side in the vicinity of the carbon film blade edge. irradiated toward the front SL laser beam, along the extending direction of the substrate cutting edge by scanning at least one line above, the laser processing step, an edge portion serving as the carbon film cutting edge of the carbon film, wherein The method includes a step of scanning by applying an outer peripheral side of the laser beam .

In this method of manufacturing a carbon film-coated drill, in the laser processing step, the light intensity distribution at the beam cross section of the laser beam shows a Gaussian distribution, and the laser beam is applied to the carbon on the rake face side or flank side from the front of the blade edge to the vicinity of the blade edge. The film is irradiated toward the film, and this laser beam scans along the extending direction of the blade edge to form the concave surface. As a result, when the carbon film excision mark by the laser beam irradiated from the front of the cutting edge is seen in a cross section orthogonal to the carbon film cutting edge, it becomes a concave curve, and the concave surface is formed along the cutting edge with high accuracy. be able to. In addition, since the outer peripheral side of the laser beam hits the tip portion (edge portion) of the carbon film, the power (intensity) density of the laser beam at the tip portion can be weakened as compared with the center portion of the laser beam. As a result, it is possible to prevent the tip end portion of the carbon film from being cut more than necessary and becoming obtuse.

In the carbon film-coated drill manufacturing method, in the carbon film forming step, the carbon film may be formed so as to be raised from the other portion on the base blade edge by CVD film formation coating.
In the carbon film-coated drill manufacturing method, in the carbon film forming step, the carbon film is formed on the base blade edge in advance from other portions, thereby providing a large margin for the carbon film in the laser processing step. Yes. Therefore, in this carbon film-coated drill manufacturing method, it becomes possible to form deeper concave surfaces and sharper edges. In addition, since the base cutting edge where the two surfaces of the rake face and the flank face are close to each other is a place where the carbon film is easy to grow, the carbon film is coated on the cutting edge portion by coating the carbon film with a thick CVD film. Can be formed higher than other portions.

In the carbon film-coated drill manufacturing method, the carbon film may be a diamond film, and the wavelength of the laser beam may be 360 nm or less.
In this carbon film-coated drill manufacturing method, since the carbon film is a diamond film and the wavelength of the laser beam is 360 nm or less, the diamond film is processed with high accuracy by a laser beam having a wavelength suitable for diamond processing. Can do.
Further, in the method for manufacturing a carbon film-coated drill, in the laser processing step, scanning of the laser beam is set to a plurality of lines of 10 lines or less, and each scanning line is partially moved while sliding the scanning line of the laser beam. It is good also as irradiating as the state which overlapped with the edge part of the said laser beam with respect to the edge part used as the said carbon film blade edge.

According to the aspects of the present invention, the following effects can be obtained.
In the carbon film-coated drill according to the first aspect of the present invention, the concave surface and the flank on the rake face side recessed toward the tool base in the carbon film in the region on the base rake face and in the region on the base flank. A concave surface is formed on each side. Furthermore, the concave surface on the rake face side and the concave surface on the flank face side intersect on the base blade edge to form a carbon film blade edge on the carbon film. Furthermore, the angle at which the concave surface on the rake face side and the concave surface on the flank side intersect is smaller than the angle formed by the base rake surface and the base flank surface. By having the above configuration, the carbon film-coated drill can have a sharper edge than before.
Further, according to the method for manufacturing a carbon film-coated drill according to the second aspect of the present invention, in the laser processing step, the light intensity distribution in the beam cross section of the laser beam shows a Gaussian distribution, and the laser beam is directed from the front of the blade edge. Irradiating toward the rake face side or flank side carbon film in the vicinity of the cutting edge, and this laser beam scans along the extending direction of the cutting edge to form the concave face. And a sharp edge can be formed.
Therefore, the carbon film-coated drill of the present invention and the carbon film-coated drill produced by the above-described method are excellent not only in wear resistance due to the carbon film but also in sharpness, and are also suitable as drills for processing non-ferrous metals and composite materials.

In one Embodiment of the carbon film coating drill and its manufacturing method concerning this invention, it is an expanded sectional view of the principal part which shows the cutting edge of a carbon film coating drill, and a laser processing process. It is a side view showing the carbon film covering drill concerning this embodiment. It is a front view of the blade part which shows the carbon film covering drill concerning this embodiment. It is a schematic whole block diagram which shows the laser processing apparatus used for the manufacturing method of the carbon film coating drill which concerns on this embodiment. In this embodiment, it is explanatory drawing which shows the relationship between the scanning direction of a laser beam, and the cross-sectional shape of a laser beam. In this embodiment, it is a conceptual diagram which shows the excision trace of the carbon film by a laser beam. It is the side view which shows the carbon film drill in connection with this embodiment, and the front view of a blade part.

  Hereinafter, an embodiment of a carbon film-coated drill and a manufacturing method thereof according to the present invention will be described with reference to FIGS. 1 to 6. In each drawing used in the following description, there is a portion where the scale is appropriately changed as necessary in order to make each member recognizable or easily recognizable.

The carbon film-coated drill 1 of this embodiment is a drill in which a carbon film 3 is formed on a base scoop surface 2c, a base escape surface 2d, and a base cutting edge 2b of a tool base 2, as shown in FIG. In the carbon film-coated drill 1, the carbon film 3 includes a concave surface 3a on the rake face side that is recessed toward the tool base 2 in a region on the base rake face 2c and a region on the base flank 2d. Concave surfaces 3a on the flank side are formed.
Further, the rake face side concave surface 3 a and the flank face concave surface 3 a intersect on the base blade edge 2 b to form a carbon film blade edge 3 b on the carbon film 3. Also, the angle θ1 at which the concave surface 3a on the rake face side and the concave surface 3a on the flank face intersect is smaller than the angle θ0 formed by the base rake face 2c and the base flank face 2d.
As shown in FIGS. 2A and 2B, the carbon film-coated drill 1 has, for example, a shank portion 1a and a pair of cutting edges 3b provided at the tip. And it has the blade part 1b in which two spiral grooves were further provided in the drill body side surface.
As shown in FIG. 6, the carbon film-coated drill 1 may include two spiral holes that open in the flank 4 b and the rake face 4 a provided at the tip and communicate with each other along the drill axis. At the time of cutting, lubricating oil is supplied to the cutting portion through this spiral hole.
In this carbon film-coated drill 1, the thickness of the carbon film 3 is not particularly limited, but is preferably 5 to 50 μm, more preferably 8 to 20 μm.

  The tool base 2 is made of a cemented carbide such as WC (tungsten carbide). The carbon film 3 is a diamond film, a graphite film, a DLC (diamond-like carbon) film, or the like formed by CVD (chemical vapor deposition) or the like.

As described above, the surface of the carbon film 3 on the side of the adjacent rake face 4a and the surface of the carbon film 3 on the side of the flank 4b have a concave face 3a on the rake face side and a concave face on the flank face side that are recessed toward the tool base. 3a is formed. The surfaces of the concave surfaces 3a on the rake face 4a side and the flank face 4b side are in contact with each other with the ridge line of the carbon film cutting edge 3b as a boundary.
For this reason, at the front end (edge, carbon film cutting edge 3b) of the carbon film 3 formed at the boundary between the pair of concave surfaces 3a, the angle θ1 (the intersection of the rake surface side concave surface 3a and the flank side concave surface 3a) The tip angle of the carbon film cutting edge 3b in the cross section perpendicular to the rake face 4a and the flank face 4b) is processed to be smaller than the angle θ0 formed by the base rake face 2c and the base flank face 2d. In other words, the carbon film 3 coating the base 2 is processed so that “θ1 <θ0”. The tip of the carbon film 3 formed on the carbon film cutting edge 3b is processed to have a curvature radius of 2 μm or less.
The preferred curvature radius of the concave surface varies depending on the size of the drill, but when the drill diameter is 0.5 mm to 20 mm, the curvature radius is preferably in the range of 5 μm to 3000 μm. A more preferable radius of curvature is 15 μm to 300 μm.
The width of the concave surface in the direction orthogonal to the extending direction of the carbon film cutting edge 3b varies depending on the size of the drill, but when the drill diameter is 0.5 mm to 20 mm, the width of the concave surface is in the range of 10 μm to 2000 μm. It is preferable to be within. A more preferable concave surface width is 20 μm to 1000 μm.
The depth of the concave surface varies depending on the size of the drill, but when the drill diameter is 0.5 mm to 20 mm, the depth of the concave surface is preferably in the range of 2 μm to 15 μm. A more preferable depth of the concave surface is 2 μm to 10 μm.

  Next, a method for manufacturing the carbon film-coated drill of the present embodiment will be described with reference to FIGS.

The manufacturing method of the carbon film-coated drill 1 according to the present embodiment includes a base preparation step of preparing a tool base 2 having a base cutting edge 2b and a base scooping face 2c and a base relief face 2d that are adjacent to each other with the base cutting edge 2b interposed therebetween. A carbon film forming step of forming a carbon film on the base rake face 2c, the base flank 2d, and the base cutting edge 2b of the tool base 2, and irradiating the carbon film 3 with a laser beam, The carbon film 3 formed in the region on the base rake face 2c and in the region on the base flank 2d is processed to provide a rake face side concave face 3a and a flank face side on the rake face side and flank face side, respectively. And a laser processing step for forming the concave surface 3a.
In the carbon film forming step, as shown in FIG. 5, the carbon film 3 is formed on the base blade edge 2 b in advance from other portions. On the substrate cutting edge 2b where the two surfaces of the substrate rake face 2c and the substrate flank 2d are adjacent, a carbon film 3 formed by chemical vapor deposition (CVD) is easy to grow. Therefore, by thickly coating the carbon film 3 by CVD film formation, as shown in FIG. 5, the carbon film 3 can be formed on the base blade edge 2b so as to be raised from other portions.

  As shown in FIG. 3, the laser processing device 21 used in the laser processing step is a device for processing by irradiating the carbon film 3 covered with the tool base 2 with a laser beam (laser light) L. The laser processing apparatus 21 includes a laser light irradiation mechanism 22, a rotation mechanism 23, a movement mechanism 24, and a control unit 25. The laser beam irradiation mechanism 22 oscillates the laser beam L, irradiates the carbon film 3 with a constant repetition frequency, and scans the carbon film 3. The rotation mechanism 23 includes a rotatable motor or the like, holds the tool base 2 covered with the carbon film 3, and applies a rotational motion around the drill axis to a workpiece having a drill shape. The rotating mechanism 23 is placed on the moving mechanism 24. The moving mechanism 24 can change its position while the rotating mechanism 23 is placed. The control unit 25 appropriately controls the laser beam irradiation mechanism 22, the rotation mechanism 23, and the moving mechanism 24 in order to perform intended laser processing.

  The moving mechanism 24 includes an X-axis stage unit 24x movable in an arbitrary direction parallel to the horizontal plane and the X direction, and a Y-axis stage perpendicular to the X direction and parallel to the horizontal plane and moving in the Y direction. A portion 24y and a Z-axis stage portion 24z movable in the Z direction, which is perpendicular to the horizontal plane. The Y-axis stage unit 24y is provided on the X-axis stage unit 24x. The Z-axis stage unit 24z is provided on the Y-axis stage unit 24y. The rotation mechanism 23 is fixed to the Z-axis stage portion 24z, and the tool base 2 can be held.

  The laser light irradiation mechanism 22 includes a laser light source 26, a galvano scanner 27, and a CCD camera 28. The laser light source 26 has an optical system that focuses light in a spot shape, and oscillates a laser beam that becomes a laser beam L by a trigger signal of a Q switch. The above-described galvano scanner 27 scans the irradiated laser beam L on the carbon film that is the workpiece. The carbon film coated tool base 2 in the held state is imaged by the CCD camera 28 described above. Then, the processing position of the tool base 2 is confirmed.

The laser beam L emitted from the laser light irradiation mechanism 22 is a single mode, and the light intensity distribution in the beam cross section shows a Gaussian distribution. That is, when an arbitrary straight line passing through the center of the beam cross section is drawn in the cross section and the light intensity on the straight line is measured, the light intensity is the strongest at the center point and goes to both outer sides of the beam cross section. Therefore, the light intensity is weak. Further, as shown in FIG. 4, the beam cross section is elliptical at the focal point.
Further, the laser beam irradiation mechanism 22 matches the scanning direction of the laser beam L with the major axis direction or the minor axis direction of the elliptical beam cross section. This is because when the scanning direction of the laser beam L is not coincident with the major axis direction or the minor axis direction of the beam cross section having the above elliptical shape and is a direction inclined with respect to the major axis or the minor axis, This is because the processed shape is inclined and deviation occurs. In the present embodiment, the scanning direction of the laser beam L is made to coincide with the minor axis direction of the beam cross section.

As the laser light source 26, one that can irradiate laser light having any wavelength of 190 to 550 nm can be used. For example, in this embodiment, laser light having a wavelength of 355 nm (third harmonic of Nd: YAG laser) is used. What can oscillate and emit is used.
When the carbon film 3 is a diamond film, an ultraviolet laser beam with a wavelength of 360 nm or less is used for the laser beam L.
The wavelength of the laser light source 26 in the laser processing step is more preferably 190 to 550 nm. More preferably, it is 190-360 nm.
The galvano scanner 27 is disposed immediately above the moving mechanism 24. The CCD camera 28 is installed adjacent to the galvano scanner 27.

  In the laser processing step, a laser beam L having a Gaussian distribution in the beam cross section is irradiated from the front of the substrate cutting edge 2b toward the carbon film 3 on the rake face 4a side or the flank face 4b side in the vicinity of the carbon film cutting edge 3b. Further, the concave surface 3a is formed by scanning along the extending direction of the base blade edge 2b. Here, the front of the base blade edge 2b is the extension when the angle bisector formed by intersecting the base scoop surface and the base escape surface in the tool cross-sectional view of FIG. 5 is extended to the outside of the tool base. It means a point on the line. Further, the extension line may be extended by being bent toward the base rake face side or the base flank side within a range of more than 0 ° and less than 90 ° with the base blade edge 2b as a fulcrum. Further, the extending direction of the base blade edge 2b means a direction orthogonal to the paper surface in FIG.

  Further, in the laser processing step, the laser beam L is irradiated from the front of the substrate cutting edge 2b. The moving mechanism 24 and the galvano scanner 27 are controlled, for example, carbon at an angle of 20 ° or less with respect to the rake face 4a or the flank face 4b. The film 3 is irradiated. Further, the laser beam L is scanned in the extending direction of the substrate blade edge 2b, that is, in the direction perpendicular to the paper surface of FIG. 1, and as shown in FIG. While the L scanning lines are slid, the respective scanning lines are partially overlapped). Note that the number of scanning lines is appropriately set according to the condensing angle and the focal position of the laser beam L. In the present embodiment, the laser beam L hits the wall surface of the tool base 2 before being focused, and it is difficult to irradiate a desired part.

In this laser processing step, the light intensity distribution in the beam cross section of the laser beam L has a Gaussian distribution. Processed shallowly. Therefore, the power density of the laser beam L that strikes the tip (edge portion) of the carbon film 3 becomes weak.
Depending on the carbon film 3, structural changes such as diamond becoming amorphous carbon can occur up to about 1 μm from the processed surface.
The amorphous carbon layer formed with a thickness of 1 μm or less from the processed surface functions as an elastic layer during cutting, thereby suppressing chipping of the cutting edge 3 b of the carbon film-coated drill 1.

  As described above, in the carbon film-coated drill 1 of the present embodiment, the carbon film 3 has a concave surface on the rake face side that is recessed toward the tool base in the region on the base rake surface 2c and the region on the base flank 2d. 3a and a concave surface 3a on the flank side are formed. Further, the rake face side concave surface 3 a and the flank face concave surface 3 a intersect on the base blade edge 2 b to form a carbon film blade edge 3 b on the carbon film 3. The angle θ1 at which the concave surface 3a on the rake face side intersects with the concave surface 3a on the flank face is smaller than the angle θ0 formed by the base rake face 2c and the base flank face 2d. By having said structure, the carbon film coating drill 1 of this embodiment can have a sharper edge than before. That is, as shown in FIGS. 1 and 5, the surfaces of the carbon film 3 on the rake face side and the flank face that are in contact with the carbon film cutting edge 3b are pierced against the extended faces of the rake face 4a and the flank face 4b. It is made concave. Therefore, the carbon film edge 3b portion of the carbon film 3 is formed in a sharp and sharp shape, and a sharper edge can be obtained than when forming a conventional chamfer.

Further, in the method of manufacturing the carbon film-coated drill 1, in the laser processing step, the laser beam L whose light intensity distribution in the beam cross section shows a Gaussian distribution is rake face 4a in the vicinity of the carbon film blade edge 3b from the front of the base blade edge 2b. Irradiation is directed toward the carbon film 3 on the side or flank 4b side. Further, the concave surface 3a is formed by scanning the laser beam L along the extending direction of the base blade edge 2b. By having the above configuration, in this method of manufacturing the carbon film-coated drill 1, as shown in FIG. 5, the cut mark of the carbon film 3 by the laser beam L irradiated from the front of the base blade edge 2b becomes a concave curve shape . The concave surface 3a can be formed along the cutting edge 2b with high accuracy.

Further, since the outer peripheral side of the laser beam L hits the tip portion (edge portion) of the carbon film 3, the power density of the laser beam L at the tip portion can be weakened. As a result, it is possible to prevent the distal end portion (edge portion) of the carbon film 3 from being cut more than necessary and becoming obtuse.
Further, in the carbon film forming process, the carbon film 3 is previously formed on the base blade edge 2b so as to be raised from other portions, thereby providing a large margin for the carbon film 3 in the laser processing process. As a result, it is possible to form a deeper concave surface 3a and a sharper edge by the manufacturing method of the carbon film-coated drill 1.

  Next, an example of a carbon film-coated drill actually produced by the method for manufacturing a carbon film-coated drill of the present embodiment will be described with reference to FIG.

  In this embodiment, the laser beam is fθ by the above laser processing apparatus capable of irradiating laser beam having a wavelength of 262 nm (Nd: YLF laser (4th harmonic wave of fundamental wave: wavelength 1047 nm)), repetition of 10 kHz and average output of 0.1 W. The drill 1 is focused by a lens (focal length f = 150 mm), and the same locus is scanned four times at a scanning speed of 25 mm / s using a galvano scanner, and a diamond coating by vapor phase synthesis is applied as a carbon film 3. The cutting edge 2a was sharpened.

As a preparation, as shown in FIG. 5, diamond having an average film thickness of 17 μm is formed on the tool base 2 made of cemented carbide by vapor phase synthesis, and the flank 4b as the cutting edge 2a and the rake face 4a are formed. A diamond film carbon film 3 having a thickness greater than the average film thickness was formed on the ridge line portion (carbon film cutting edge 3b). For the measurement of carbon film quality, Raman spectroscopy was used.
Further, as described above, since the portion of the cutting edge 2a has more film formation sites than the plane, the diamond film (carbon film 3) is formed thick and rounded.

For example, as shown in FIG. 1, first, an average carbon film thickness in a region on the rake face 4a that is 100 μm or more away from the base blade edge 2b of the tool base 2 along the rake face 4a is defined as an average film thickness ta. Next, the average carbon film thickness of the region on the rake face up to 50 μm along the rake face 4a from the base cutting edge 2b is defined as the average film thickness te. This average carbon film thickness te includes a part of the thick and rounded portion before laser processing.
In this embodiment, the average film thickness ta is set to 5 μm or more. In addition, a diamond film was formed so as to have a relationship of “te> ta”.

  Next, the rake face 4a and the flank face 4b were inclined by 10 ° with respect to the irradiation direction of the laser beam L, and the laser beam L was scanned from each direction in parallel with the ridge line of the substrate cutting edge 2b. In this case, the laser beam L is scanned in parallel with the extending direction of the finally formed carbon film cutting edge 3b. As shown in FIG. 5, the first beam irradiation target position P1 is an extension line of the average height of the rake face 4a and the flank face 4b (not including the thick rounded part formed in the part of the cutting edge 2a). It was set at a position shifted by 4 μm to the outside of the carbon film cutting edge 3b from the intersection of 4d and 4c and the thick rounded carbon film 3 surface of the cutting edge 2a.

  Thus, in the carbon film-coated drill 1 produced by the above-described manufacturing method, the rake angle of the tool base 2 is 28 °. However, in the carbon film-coated drill 1 produced by laser processing of the carbon film 3, the rake angle is 30 ° and the rake angle was kept at a larger angle.

  Table 1 shows the results of performing cutting tests on the carbon film-coated drills according to the examples of the present invention and measuring the lifespan by drilling. As a comparative example, Table 1 also shows the results of measurement in the same manner for a drill with a conventional carbon film (diamond film) coating that has not been laser processed. As the workpiece (workpiece), CFRP (carbon fiber reinforced plastic) in which carbon fiber and thermosetting epoxy resin have an orthogonal laminated structure is used, and the processing conditions at the time of drilling are as shown in Table 1. It is. In addition, the life determination was performed based on the number of times of piercing in which burrs or delamination occurred.

  As can be seen from the results, in the carbon film-coated drill of the comparative example, burrs or delamination occurred 350 times, whereas in the carbon film-coated drill of this example, burrs or delamination did not occur until 520 times. As a result, it was confirmed that the cutting force was reduced with a sharp cutting edge, thereby extending the service life.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  Since the carbon film-coated drill of the present invention has a sharp cutting edge shape, cutting resistance is reduced. As a result, the service life of the present carbon film drill is extended.

DESCRIPTION OF SYMBOLS 1 Carbon film covering drill 2 Tool base 2a Cutting edge 2b Base cutting edge 2c Base rake face 2d Base flank 3 Carbon film 3a Concave surface 3b Carbon film edge 4a Rake face 4b Flank θ0 Angle formed by base rake face and base flank θ1 The angle at which the concave surface on the rake face and the concave surface on the flank face intersect

Claims (10)

A carbon film-coated drill (1),
A tool substrate (2) having a substrate cutting edge (2b) and a substrate scooping surface (2c) and a substrate relief surface (2d) adjacent to each other with the substrate cutting edge (2b) interposed therebetween;
A carbon film (3) formed on the substrate cutting edge (2b), the substrate rake face (2c), and the substrate flank (2d);
The carbon film (3) includes a concave surface (3a) on the rake face side that is recessed toward the tool base in a region on the base rake face (2c) and a region on the base flank (2d). Concave surfaces (3a) on the flank side are respectively formed,
The concave surface (3a) on the rake face side and the concave surface (3a) on the flank face side intersect on the base blade edge (2b) to form a carbon film blade edge (3b) on the carbon film (3). ,
The angle (θ1) at which the concave surface (3a) on the rake face side and the concave surface (3a) on the flank side intersect is an angle (θ0) formed by the base rake surface (2c) and the base flank surface (2d). A carbon film coated drill characterized by being smaller.   The carbon film-coated drill (1) according to claim 1, wherein the carbon film is a diamond film. The carbon film-coated drill according to claim 1 or 2, wherein a cross section of the concave surface (3a) on the rake face side and the concave surface (3a) on the flank face side is a concave curve by a surface orthogonal to the carbon film cutting edge. (1). The carbon film-coated drill (1) according to claim 3 , wherein the rake face side concave surface (3a) and the flank side concave surface (3a) are orthogonal to the carbon film cutting edge (3b), respectively. A carbon film-coated drill (1) whose width in a direction along the surface is in the range of 10 μm to 2000 μm. The carbon film-coated drill (1) according to claim 3 , wherein a depth of the concave surface (3a) on the rake face side and a concave surface (3a) on the flank face side is within a range of 2 µm to 15 µm. Coated drill (1). The carbon film-coated drill (1) according to claim 3 , wherein the rake face side concave surface (3a) and the flank side concave surface (3a) in a direction perpendicular to the carbon film cutting edge (3b). The width is in the range of 10 μm to 2000 μm,
A carbon film-coated drill (1) in which the rake face side concave surface (3a) and the flank side concave surface (3a) have a depth in the range of 2 μm to 15 μm. A method of manufacturing a carbon film-coated drill, comprising:
A base preparation step of preparing a tool base (2) having a base cutting edge (2b) and a base scooping surface (2c) and a base escape surface (2d) adjacent to each other with the base cutting edge (2b) interposed therebetween;
A carbon film forming step of forming a carbon film (3) on the base rake face (2c), the base flank face (2d), and the base cutting edge (2b) of the tool base (2);
The carbon film (3) formed in the region on the base rake face (2c) and the region on the base flank (2d) is processed by irradiating the carbon film (3) with a laser beam. A laser processing step for forming a rake face side concave surface (3a) and a flank face concave surface (3a) on the rake face side and the flank face side, respectively,
The rake face side and the flank concave face (3a) intersect on the base blade edge (2b) to form a carbon film blade edge (3b),
In the laser processing step, the light intensity distribution in the beam cross section of the laser beam shows a Gaussian distribution,
Irradiating the laser beam from the front of the base blade edge (2b) toward the carbon film (3) on the rake face side or the flank face side in the vicinity of the carbon film blade edge (3b) ,
Before SL laser beam scans at least one line or more in the extending direction of the base edge (2b),
The laser processing step includes a step of scanning by applying an outer peripheral side of the laser beam to an edge portion of the carbon film (3) to be the carbon film cutting edge (3b). Manufacturing method. It is a manufacturing method of the carbon film covering drill according to claim 7 ,
In the carbon film forming step, a method of manufacturing a carbon film-coated drill, wherein the carbon film (3) is formed on the base blade edge (2b) by raising the carbon film (3) from another portion by CVD film coating. A method for producing a carbon film-coated drill according to claim 7 or 8 ,
The carbon film is a diamond film;
The manufacturing method of the carbon film coating drill whose wavelength of the said laser beam is 360 nm or less.   It is a manufacturing method of the carbon film covering drill according to any one of claims 7-9,
  In the laser processing step, scanning with the laser beam is a plurality of lines of 10 lines or less, and while the scanning line of the laser beam is slid, irradiation is performed with each scanning line partially overlapped,
  A method of manufacturing a carbon film-coated drill, wherein an outer peripheral side of the laser beam is applied to an edge portion serving as the carbon film blade edge (3b).

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