JP2007054945A - Diamond tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diamond tool which includes a cutting edge formed on a diamond tip, and assures high precision with a small cutting resistance when the tool is of micro-structure for ultra-precision processing capable of performing easy processing even if the cutting edge is of an R-form or in a complicated shape. <P>SOLUTION: The diamond tool has the diamond tip having a protruded forefront where the cutting edge is formed, in which the protruded portion has a rake face, a first flank formed as a surface consisting in a combination of a curved surface and/or plane and having a relatively small runoff angle, and a second flank formed from a plurality of planes and having a relatively large runoff angle, wherein the cutting edge is formed at the boundary between the rake face and the first flank, or further even at the boundary between the rake face and the second flank. The PV values of the surface around the part where the cutting edge is formed so as to be 3-300 nm on the rake face and 3-2000 nm on the flanks. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cutting tool for precision machining in which a cutting edge is formed on diamond, and in particular, an ultra-precision machining such as a mold for optical element molding such as an optical sheet for a display such as a television screen or a mobile phone or a light guide plate. It is related with the diamond tool for performing.

Conventionally, for the optical surface processing of molds for optical elements such as optical disk pickup objective lenses and optical sheets, single-crystal diamond R cutting tools having an arcuate cutting edge at the tip are used. In order to obtain a high-precision optical surface only by cutting, a circular arc having a radius of about 0.05 μm to 2.5 μm is used. As a specific example of this R bite, there is a cutting edge whose arc part width is 0.8 μm, apex angle is 30 °, relief angle of the first flank is 11 °, and relief angle of the second flank is 45 °. Diamond bite is given. (For example, see Patent Document 1)
In addition, as a diamond cutting tool having a general shape cutting blade with a complicated cutting edge, there is a diamond cutting tool processed using a laser in the ultraviolet region for processing the cutting blade. This diamond tool is capable of obtaining a highly accurate cutting edge by using a laser whose wavelength is in the ultraviolet range, even if the cutting edge ridge is a complex shape consisting of a combination of straight lines and curves. It is. (For example, see Patent Document 2)
Furthermore, as a tool for processing a fine groove, a multi-chip diamond tool having a plurality of chips on a diamond has been proposed. In this tool, a cutting edge is formed on each chip, and the chip is formed using, for example, a focused ion beam. (For example, see Patent Document 3)
JP 2003-62707 A (paragraph number 0055, FIG. 3) Japanese Patent Laid-Open No. 2003-25118 (paragraph number 0019, FIG. 1-3) JP 2005-527394 A

  When forming a cutting edge in the shape of an R bit as in the above-mentioned Patent Document 1, a process for forming a flank according to the shape of the cutting edge ridge line is performed. That is, first, the flank face of the straight cutting edge portion is ground and lapped so that the clearance angle of the R cutting edge portion at the front end and the straight cutting edge portion at the rear side thereof are the same, and then the flank face of the R cutting edge portion is formed. Grinding and lapping on curved surfaces. Finally, the rake face is ground and lapped to perform cutting and form a cutting edge. However, since the flank of the R cutting edge portion is a curved surface, it takes a long time for processing or is complicated and troublesome. Further, as in Patent Document 2, when a cutting blade having a complicated shape in which straight lines and R are combined, a shape may be formed using a laser or the like, but it takes a lot of time because of the large amount of processing. Become. Furthermore, in the case of a tool for ultra-precision machining, since it becomes fine machining, the elastic recovery phenomenon of the workpiece due to the burnishing action occurs, and the flank surface may interfere with the workpiece and increase the cutting resistance. . Further, in the grooving tool of Patent Document 3, it is said that the cutting edge is formed by the focused ion beam, but the cutting edge formed by the focused ion beam is more accurate than the cutting edge formed by lapping. The sharpness is inferior, and when grooving is performed with such a tool, the accuracy of the wall surface of the groove may be deteriorated and machining may not be performed with the required accuracy. The present invention is easily processed even with an R cutting edge, a complicated shape cutting edge or a grooving cutting edge required for performing ultra-precision machining such as a mold for molding an optical element, In a fine ultra-precision machining tool, a diamond tool having a cutting edge with high precision, low cutting resistance and good sharpness is provided.

  In the present invention, most of the flank that is complicated with a cutting edge having an R shape or a complicated shape is configured by a combination of planes, and the flank having a shape in which only the periphery of the cutting edge is matched to the shape of the cutting edge. Thus, the amount of machining of the flank face having a complicated shape is reduced, and the diamond tool can be easily obtained at low cost.

  A first feature of the diamond tool of the present invention is a diamond tool having a diamond tip having a convex tip, and a cutting blade formed on the convex portion, wherein the convex portion includes at least the cutting blade. A first flank having a rake face having a peripheral PV value of 3 to 300 nm, a surface having a PV value of 3 to 2000 nm and a combination of a curved surface and / or a flat surface and a relatively small clearance angle, and at least a PV value Has a second flank with a relatively large flank angle, which is composed of a plurality of planes including a plane of 3 to 500 nm, and the cutting edge is a boundary portion between the rake face and the first flank face It is to be formed. The PV value is the maximum width (maximum distance between peaks and troughs) of the processed surface in the case of a flat surface, and the theoretical surface of the processed surface is flat in the case of a curved surface. It represents the maximum width of the uneven surface (maximum distance between peaks and valleys).

  In the R cutting tool having the R cutting edge and the total cutting tool combined with the straight line and the curve for performing the total machining, as described above, the clearance of the plane having a relatively large clearance angle as the second flank as previously described. A plurality of surfaces are provided to form a rough shape, and the portion of the cutting edge can be formed as a first flank by providing a flank according to the cutting edge shape with a relatively small flank angle. When the flank is formed, a cutting blade combined with R and straight lines can be easily formed with a small amount of processing. In addition, since the second flank is a flat surface, it can be easily polished with high accuracy, and the first flank can be formed after the second flank is made highly accurate. Can be easily formed. Of the rake face, the face having a PV value of 3 to 300 nm is preferably at least a region within 0.5 mm from the cutting edge.

  The second feature is that the cutting edge is an arcuate cutting edge, and the first flank of the portion where the cutting edge is formed is a cylindrical surface.

  If the first flank is a cylindrical surface when an arc-shaped cutting edge is used, even if the rake face is ground in parallel when the cutting edge is worn, Since the shape of the blade does not change, re-polishing is possible and the tool life can be extended.

  A third feature is that the cutting edge is a cutting edge having a general shape constituted by a combination of curves and / or straight lines having different Rs.

  In the case of a cutting blade having an overall shape, the flank can be easily formed with the structure of the diamond tool of the present invention, and a highly accurate cutting blade is formed.

  Another feature of the diamond tool of the present invention is a diamond tool having a tip with a convex diamond tip and a cutting edge formed on the convex portion, wherein the convex portion is at least around the cutting edge. A rake face having a PV value of 3 to 300 nm, a first flank face having a PV value of 3 to 2000 nm and a curved surface having a relatively small relief angle, and a plurality of planes having a PV value of 3 to 500 nm A second flank having a relatively large clearance angle, and the cutting edge is formed at the boundary between the rake face and the first flank face, the rake face and the second rake face. It consists of the linear cutting blade formed in at least one part of the boundary part with a flank.

  In the case of a grooving tool having an R cutting edge at the tip and a straight cutting edge on the rear side, the accuracy of the wall surface forming the boundary of the groove is required. The cutting blade is required to have high accuracy. As described above, a plurality of planar relief surfaces having a relatively large relief angle are provided in advance as the second relief surface, and then the first relief surface having a relatively small relief angle and a curved surface is provided at the tip. With the formed structure, since the second flank is a flat surface, it is easily polished with high precision to form a very sharp linear cutting edge, and then the first flank is formed. A curved cutting edge is formed with high accuracy with a small amount of machining.

  A fourth feature is that the width of the first flank is 60 μm or less.

  In this way, by reducing the width of the first flank formed of a curved surface or a combined surface, the amount of processing of the flank having a complicated shape can be easily reduced and fine processing can be performed. In this case, the flank can be prevented from interfering with the workpiece. The first flank is preferably a mirror surface with no polishing marks.

  The fifth feature is that the difference between the clearance angle of the first flank and the clearance angle of the second flank is 10 to 75 °.

  By providing a difference in clearance angle of 10 ° or more, the second flank can be prevented from interfering with the workpiece even when fine machining is performed, and the strength of the blade edge is ensured by setting it to 75 ° or less. To do. The larger the clearance angle difference is, the more the machining amount of the first clearance surface can be reduced. Therefore, especially in the case of a complex-shaped cutting blade, the clearance angle should be as much as possible. A larger difference is preferable, and 60 ° or more is preferable.

In the diamond tool of the present invention, since most of the flank is formed as a flat surface, high-accuracy polishing is easily performed, and the first flank and rake surface polished with high accuracy are easily in contact with the first flank. Since the flank is formed, it is easy to finish the first flank with high precision, and the first flank that is a combination of a curved surface and a flat surface reduces the amount of processing, making it easy to cut the cutting edge. A high-precision cutting blade can be formed efficiently and easily.
In addition, by using a two-step flank, it is possible to prevent interference with the work material while ensuring the strength of the cutting edge even in the case of a fine cutting edge for ultra-precision machining.

  As a first example of the diamond tool of the present invention, a single crystal diamond tool is shown in FIG. 1, and an enlarged perspective view of the tip is shown in FIG. In the diamond tool 1, a tip 2 made of single crystal diamond is fixed to the tip of a tool body 3 made of cemented carbide by brazing or the like. The tip 2 has a convex tip, and an arcuate cutting edge 7 is formed on the convex portion. The cutting edge 7 is formed by the rake face 4 and the first flank 5 intersecting each other. Yes. A straight ridge line is formed behind the arcuate cutting edge 7, but this portion does not act as a cutting edge. On the opposite side of the first flank 5 from the rake face 4, a second flank 6 having a plurality of planes is formed. The second flank 6 has a clearance angle larger than that of the first flank 5. Is getting bigger. That is, the first flank 5 is provided at the intersection of the rake face 4 and the second flank 6 and has a width of 60 μm or less. And the difference of the flank angle of the 1st flank 5 and the 2nd flank 6 is 10-75 degrees. Further, in the normal diamond tool, the flank of the arcuate cutting blade is often formed as a conical surface, but in the diamond tool of the present invention, the first flank 5 is a cylindrical surface. . With such a surface, when the rake face 4 is polished in parallel when the cutting edge 7 is worn, the radius R of the arcuate cutting edge 7 does not change, and the cutting edge 7 having the same shape can be regenerated. . A straight ridge line behind the arcuate cutting edge 7 is formed by the intersection of the rake face 4 and the second flank faces 6a and 6b.

  The PV value of each face of the diamond tip 2 is 3 to 300 nm at least in the range from the cutting edge 7 to 0.5 mm of the rake face 4, 3 to 2000 nm for the first flank 5, and the second flank 6. Is 3 to 500 nm and 0.1 to 5 μm depending on the surface.

  A second example of the tip of the diamond tool of the present invention is shown in FIG. As in the above example, the tip 2 has a convex tip, and an arcuate cutting edge 7 is formed on a part of the convex part. 7, cutting edges 7a having different curves of R are formed. These cutting edges 7 and 7a are formed by the rake face 4 and the first flank 5 intersecting each other. A straight ridge line is formed behind the cutting edge 7a having a different curve R. This ridge line is formed by the intersection of the rake face 4 and the second flank faces 6a and 6b. A step is formed between the cutting edge 7a and the linear ridge line. About another point, it is the same as that of said example.

  A third example of the tip of the diamond tool of the present invention is shown in FIG. Like the above example, the tip 2 has a convex tip, and a zigzag cutting blade 7 is formed at the tip of the convex portion. The total cutting edge 7 has a shape in which straight cutting edges are connected in a zigzag shape. These cutting edges 7 are formed by the rake face 4 and the first flank 5 (5a to 5h) intersecting each other. Is formed. A straight ridge line is formed behind the cutting edge 7, and this ridge line is formed by the intersection of the rake face 4 and the second flank faces 6a and 6c. In this example, the second flank 6 is composed of three surfaces 6a, 6b, and 6c, and the PV values of the second flank 6a and 6c are 3 to 500 nm. 6b is 0.1-5 micrometers.

  A fourth example of the tip of the diamond tool of the present invention is shown in FIG. As in the first example, the tip 2 has a convex tip, and an arcuate cutting edge 7 is formed on a part of the convex part, but the point different from the first example is as follows: A linear cutting edge 7b is formed continuously with the arcuate cutting edge 7, and the arcuate cutting edge 7 is formed by the rake face 4 and the first flank 5 intersecting, and the linear cutting edge 7b is The rake face 4 and the second flank 6 intersect each other. The boundary between the arcuate cutting edge 7 and the linear cutting edge 7b has no step and the cutting edge is formed on a continuous ridgeline. The second flank 6 is formed by two surfaces 6a and 6b, both of which are polished surfaces with a high PV value of 3 to 500 nm. About another point, it is the same as that of said example.

  The diamond tool of the present invention as described above can be obtained by forming a highly accurate surface by grinding and polishing the rake surface and the second flank, and finally forming the first flank, The first flank can be formed by processing using a laser, a focused ion beam, or the like in addition to processing by grinding or polishing.

  A diamond cutting tool having a chip having the shape shown in FIG. 2 was manufactured as a diamond tool of the present invention, and a diamond cutting tool having a chip having a shape shown in FIG. 6 was manufactured as a conventional diamond tool, and a cutting test was performed. . In the diamond tool tip of the present invention, the PV value of each surface is such that the rake face 4 is 100 nm, the first flank 5 is 100 nm, the second flank 6 is composed of two flat surfaces, one surface 6a and the other. One surface 6b is 50 nm. The width of the first flank 5 (length in the vertical direction in FIG. 2) is 45 μm at the maximum, and the flank angle is 7 ° for the first flank 5 and the second flank 6. Is 13 ° on one side 6a and the other side 6b. The shape of the cutting edge 7 is a shape in which three types of Rs having different sizes are combined. By forming the second flank with high accuracy, the first flank is then formed into a laser or focused ion beam. High-precision cutting blades can be obtained with high-precision machining by machining combined with machining, and a cutting blade with a shape that was extremely difficult to manufacture with the conventional flank face is created. I was able to. On the other hand, we tried to produce a diamond tool that has a flank with a conventional configuration and has a cutting edge with a shape that combines three types of Rs with different sizes. Could not be created.

  Using the diamond tool of the present invention, oxygen-free copper was cut. The machining is to form a groove having a depth of 10 μm by fly cutting, and the cutting conditions are a cutting speed of 565 m / min, a tool cutting of 5 μm, and a feed of 40 mm / min.

  As a result of conducting a cutting test under the above conditions, it was found that the diamond tool of the present invention had a good shape transfer of 100 nm, and that the diamond tool of the present invention can perform high-precision processing. Further, since the strength of the blade edge was high and chipping was difficult to occur, the life was improved and no interference with the workpiece was generated.

  As Example 2 of the diamond tool of the present invention, a diamond cutting tool having a chip shape shown in FIG. 5 was manufactured, and as a conventional diamond tool, a diamond cutting tool having a chip shape shown in FIG. A test was conducted. In the diamond tool tip of the present invention, the PV value of each face is 100 nm for the rake face 4, 500 nm for the first flank face 5, and the second flank face 6 is composed of two flat surfaces, both of which are 50 nm. is there. The width of the first flank 5 (vertical length in FIG. 2) is 25 μm at the maximum, and the flank angle is 7 ° for the first flank 5 and the second flank 6. Is 13 ° on both sides. The shape of the cutting edge 7 is a constant R shape, and is smoothly connected to the straight cutting edge 7a formed on the rear side thereof without any step. On the other hand, the tip of a conventional diamond tool was manufactured by grinding and polishing so as to have a conical flank at the tip and a flat flank on the rear side.

  Using the diamond tool of the present invention, oxygen-free copper was cut. The machining is to form a groove having a depth of 35 μm by fly cutting, and the cutting conditions are a cutting speed of 565 m / min, a tool cutting of 5 μm, and a feed of 40 mm / min.

  As a result of performing a cutting test under the above conditions, it was found that the diamond tool of the present invention had a good shape transfer of 700 nm, and that the diamond tool of the present invention can perform high-precision processing. Further, since the strength of the blade edge was high and chipping was difficult to occur, the life was improved and no interference with the workpiece was generated.

It is a figure which shows the example of the diamond tool of this invention, (a) is a top view, (b) is a front view. It is a perspective view which shows the 1st example of the chip | tip of the diamond tool of this invention. It is a perspective view which shows the 2nd example of the chip | tip of the diamond tool of this invention. It is a perspective view which shows the 3rd example of the chip | tip of the diamond tool of this invention. It is a perspective view which shows the 4th example of the chip | tip of the diamond tool of this invention. It is a perspective view which shows the example of the chip | tip of the conventional diamond tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diamond tool 2 Diamond tip 3 Tool main body 4 Rake face 5 First flank 6 Second flank 7 Cutting edge

Claims (6)

A diamond tool having a tip with a convex diamond tip and a cutting edge formed on the convex portion,
The convex portion is composed of at least a rake face having a PV value of 3 to 300 nm around the cutting edge and a curved surface and / or a plane having a PV value of 3 to 2000 nm and a relatively small clearance angle. A first flank and a second flank having a relatively large flank angle composed of a plurality of planes including a plane having a PV value of at least 3 to 500 nm, and the cutting edge includes the rake face and A diamond tool formed at a boundary with the first flank.   2. The diamond tool according to claim 1, wherein the cutting edge is an arcuate cutting edge, and the first flank of a portion where the cutting edge is formed is a cylindrical surface.   2. The diamond tool according to claim 1, wherein the cutting blade is a cutting blade having a general shape formed by a combination of curves and / or straight lines having different Rs. A diamond tool having a tip with a convex diamond tip and a cutting edge formed on the convex portion,
The convex portion includes at least a rake face having a PV value of 3 to 300 nm around the cutting edge, a first flank face having a PV value of 3 to 2000 nm and a curved surface having a relatively small clearance angle, and PV And a second flank having a relatively large flank angle composed of a plurality of planes having a value of 3 to 500 nm, and the cutting edge is formed at a boundary between the rake face and the first flank. A diamond tool comprising an R cutting edge and a linear cutting edge formed at least at a part of a boundary portion between the rake face and the second flank face.   The diamond tool according to claim 1, wherein a width of the first flank is 60 μm or less.   The diamond tool according to any one of claims 1 to 5, wherein a difference between a clearance angle of the first flank and a clearance angle of the second flank is 10 to 75 °.

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