JP5336095B2 - Laser diamond cutting tool and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long tool life for a diamond tip mounted on a diamond cutting tool. <P>SOLUTION: After completing shape forming of the diamond tip mounted on the distal end of the diamond cutting tool such as a diamond cutting tool, an ultrashort pulsed laser beam is cast to the surfaces of the diamond tip in contact with a workpiece so that a finely rugged surface having a periodic structure of 5 nm to 3,000 nm is formed. Since frictional resistance between the tip and the contact surface is reduced, the resistance during the cutting is lowered, realizing the longer tool life of the diamond tip. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a diamond cutting tool having a diamond cutting edge at a tip, in particular, a diamond cutting tool, a diamond roller cutter, a microtome, and a method for manufacturing a diamond cutting tool.

  Ultra-precision machining using diamond as a cutting tool is possible with ultra-precision cutting surfaces such as polygon mirrors for light beam scanners, copy drums for copiers, aluminum bases for memory disks, infrared laser resonators and condenser mirrors. It has been put to practical use for equipment required for reflection and precision film formation. The diamond tool is an important tool that is often used for finishing a mold or decorating a metal surface. In addition, the diamond cutting edge can be used as a microtome.

  The diamond cutting tool is made of aluminum or copper. Further, since the wear of the diamond blade tip is fast, it cannot be practically used in a normal environment, but it is also used for processing an iron-based material in an atmosphere in a special gas so as to suppress the progress of wear. In many cases, the microtome is cut by organic matter.

  In order to use a diamond cutting tool in the production process of a mass-produced product, it is required that the cutting edge has a long life and that the cutting performance is stable. Diamond is the material with the highest hardness, but since it is easily carbonized at a temperature of 873 K (600 ° C.) or higher in the air, it will not be in such a high temperature region due to friction with the work material during cutting. There is a need to.

  The cutting edge of the diamond cutting tool is finished by “polishing”. The surface that forms the cutting edge is a smooth mirror surface for polishing finishing. For this reason, the slip of the work material such as chips is poor, and it becomes a resistance during machining. Due to resistance at the time of machining, the temperature rises when machining at high speed, so the machining speed must be suppressed. In addition, resistance during processing is one of the causes of damage to diamond tools. On the other hand, in the case of a microtome, there are cases where it is difficult to peel off a section cut with a mirror surface with a smooth polished surface of the cutting edge.

  On the other hand, with the progress of ultrashort pulse laser technology, it is being developed to form a fine periodic structure in a material such as metal or silicon and use it for industrial applications.

Japanese Patent Laid-Open No. 2003-25118 JP 2003-57422 A JP 2003-334683 A JP 2004-360011 A JP 2004-360012 A JP 2006-212646 A

  The problem to be solved by the present invention is to improve the processing speed and durability with a diamond cutting tool, reduce friction, facilitate peeling of cutting chips from the diamond surface, and improve the mirror surface performance of the cutting surface. Therefore, the chip processing is facilitated, and the sharpness of the processed part by the diamond tip is improved.

  If the friction can be reduced, it is possible to design in a use situation where the rake angle and clearance angle cannot be used conventionally, and the degree of freedom in designing the blade edge angle increases. The same applies not only to diamond tools but also to microtome diamond knives.

  The present invention applies a fine periodic structure created by an ultrashort pulse to a diamond tip in a diamond cutting tool, thereby improving the durability and processing efficiency of the diamond tip and extending its life in ultraprecision machining.

  In order to solve the above-mentioned problems, the present invention provides a diamond cutting tool including a diamond cutting edge that contacts and cuts a workpiece, and has a period on at least one contact surface or ridge portion of the diamond cutting edge that contacts the workpiece. It has a striped fine irregular surface of structure.

  The period of the striped fine uneven surface is 5 nm to 3000 nm.

  Further, the diamond blade tip is a diamond tip having a circular arc shape, a straight blade shape, or a triangular blade shape. Further, the diamond blade tip is a diamond tip having an elliptical blade shape, a parabolic blade shape or a hyperbolic blade shape.

  The diamond chip has a striped fine uneven surface having the periodic structure on the rake face, the flank face, and the surface of the edge line where the flank face and the rake face intersect.

  Further, the diamond cutting tool is a diamond roller cutter, the diamond cutting edge has a abacus ball shape, and has a striped fine irregular surface of the periodic structure on a ridge line portion in contact with the workpiece. To do.

  Furthermore, the diamond blade edge is a microtome, and has a ridgeline of the blade edge, an inclined surface that forms the ridgeline, and a stripe-shaped fine irregular surface of the periodic structure on an inclined surface sandwiched between the inclined surfaces.

  On the other hand, the present invention provides a method of manufacturing a diamond cutting tool provided with a diamond cutting edge that contacts and cuts a workpiece, and a laser beam is applied to a contact surface of the cutting edge with at least one workpiece after the shape forming step of the cutting edge. The step of forming a striped fine irregular surface having a periodic structure by irradiation

  The laser beam may be a laser beam having a strong and weak periodic power distribution due to optical interference caused by irradiation with a femtosecond laser pulse. The laser beam may be a laser beam having a strong and weak periodic power distribution due to optical interference caused by irradiation with a laser pulse having a pulse width of 10 fs to 2000 fs.

  The period of the striped fine uneven surface of the periodic structure is 5 nm to 3000 nm.

  Further, the wavelength band of the laser beam is based on a laser beam having a wavelength spectrum from the near infrared region to the ultraviolet region. Further, the laser light has a wavelength of 100 nm to 2000 nm. The laser beam is a solid-state laser beam.

  Furthermore, the laser light is laser light that has passed through a condensing optical system composed of a spherical lens, an aspherical lens, a cylindrical lens, a reflecting mirror, or a combination thereof.

  By forming fine irregularities on the surface of the diamond cutting edge in diamond tools, etc., it is possible to reduce the contact frictional resistance of the rake face and flank caused by the adhesion between the cutting edge and the surface of the diamond cutting edge. In this case, chemical interaction with diamond can be reduced, and the life of the cutting edge can be extended.

  It also facilitates the removal of cutting chips from the tool surface that occur during cutting and incision processing, reduces the peeling phenomenon of the workpiece from the machining surface, and reduces the applied force of the tool toward the workpiece required for cutting . Therefore, the processing heat generated between the cutting edge and the workpiece is reduced, and the rise in the cutting edge temperature is reduced. This leads to longer life by reducing wear of the diamond cutting edge of the cutting tool. Even in a diamond roller cutter using an abacus-shaped blade, the applied force required for cutting can be reduced, cracks can be prevented from being generated around the cutting line, and the surface finish of the cut portion can be improved. In the microtome, friction between the cutting surface and the tool blade surface can be reduced, and high-precision fine processing is possible.

  FIG. 1 shows a diamond tool 100 according to the present invention. (A) is a top view, (b) is a side view. The diamond tip 1 is directly brazed (joined to be alloyed) to the shank 2 of the diamond tool 100. The diamond tip 1 has a cutting edge portion 4 and cutting edge surfaces 5 and 6.

  FIG. 1 (c) shows that the diamond tip 1 is used for cutting the workpiece 10. A bite shank (not shown) is mounted on a cutting machine (not shown), the diamond blade tip 4 is pressed against the workpiece 10, and the blade tip 4 is moved relative to the workpiece 10 in the direction of arrow 14. The workpiece 10 is cut and peeled from the surface of the workpiece 10 along the rake face 7 of the cutting edge of the diamond tip 1 (corresponding to the cutting edge surface 5 in FIG. 1 (b)) with a cutting thickness of 11. It becomes cutting waste 12 and is separated from the workpiece 10 in the direction of arrow 13. The workpiece 10 that has passed through the rounded portion 8 of the cutting edge portion 4 (although the cutting edge has a radius of curvature of the order of microns when enlarged) is a flank 9 that corresponds to the burnishing portion (corresponding to the cutting edge surface 6 in FIG. 1B). The processed surface 15 is formed by feeding the diamond chip 1 rearward along the traveling direction 14 of the diamond tip 1.

  The shape of the diamond cutting edge includes an arc shape, a straight shape, a triangular shape, and an abacus ball shape. In addition, there are shapes represented by quadratic functions such as an elliptical shape, a parabolic shape, and a hyperbolic shape. Among these, the arc shape, the straight shape, the triangular shape, the elliptical shape, the parabolic shape, or the hyperbolic shape is expressed by a blade shape when the cutting tool is viewed from above. FIG. 2 shows a cutting tool in which a circular, linear, triangular, elliptical, parabolic or hyperbolic diamond tip 1 is attached to a bite shank 2. (A) (b) is a side view of a cutting tool, and a cutting tool becomes a form of either (a) or (b). (C)-(h) is a top view, and shows the circular arc shape, the linear shape, the triangular shape, the elliptical shape, the parabolic shape, and the hyperbolic shape, respectively.

  In the present invention, the diamond tip 1 of the diamond cutting tool 100 is directed toward the ridgeline of the portion where the rake face 7 and the flank face 9 forming the rounded portion 8 of the blade intersect, the rake face 7 and the flank face 9. Irradiation with an ultra-short pulse laser beam forms a fine periodic uneven surface on the surface and processes it.

  On the other hand, the abacus bead shape is the shape of a diamond cutting edge when used as a cutting tool, that is, a roller cutter, for cutting a workpiece by rotating a blade having the shape of a rotating body in contact with the workpiece. . The roller cutter has a structure shown in FIG. (A) is a front view, (b) is a side view, and (c) is a cross section of the X-X ′ portion in the side view. The roller cutter 50 has a diamond blade 51 in the shape of an abacus ball. The blade 51 is sandwiched between the support columns 52 on both sides, and the tapered portion 53 of the support column has an inclination different from the inclination of the side surface of the blade 51, so that the blade 51 contacts the blade 51 only at the distal end portion 56. For this reason, the blade 51 is rotatable about a straight line connecting the tip portions 56 on both sides. The workpiece is cut by the rotation of the blade 51. The support column 52 is fixed to the handle 54. The edge 51 of the ridge line where the blade 51 contacts the workpiece is irradiated with an ultrashort pulse laser to provide fine periodic irregularities on the surface so as to have a sharp tip like a kind of saw blade.

  Further, fine periodic irregularities can also be applied to a diamond microtome cutting edge 40 as shown in FIG. The ridgeline 41 of the blade edge, the inclined surface 42 forming the ridgeline, and the surface of the slope 44 sandwiched between the inclined surfaces 42 are irradiated with an ultrashort pulse laser to form fine irregularities on the surface. The non-inclined side surfaces 43, 45, and 46 are not necessarily provided, but may be provided. By providing this surface shape, friction between the cutting surface and the tool blade surface can be reduced, and high-precision fine processing can be performed.

  The fine irregularities on the surface of the diamond tip, the abacus-shaped blade, and the microtome edge shown above are, for example, ultrashort pulses having a pulse width of several tens to several hundreds of femtoseconds, and the wavelength of the fundamental wave. Is formed by irradiating a laser having a wavelength of 700 nm to 1500 nm and its harmonics. The ultrashort pulse irradiation technique can be implemented using a configuration using a known solid-state laser. FIG. 5 shows one form. In this embodiment, the wavelength of a mode-locked pulse obtained from a fiber laser having a pulse width of several hundred femtoseconds is tuned so as to match the amplifier, and a laser in the near-infrared wavelength region with high output by a titanium sapphire amplifier. A pulse oscillator 20 is used. Further, a laser light source that can be easily obtained as an industrial laser apparatus capable of forming a striped fine uneven surface having a periodic structure has a pulse width of 10 fs to 2000 fs.

  The laser pulse 21 is divided into two beams 23 and 28 by a beam splitting mirror 22, one of which is reflected by the mirror 24 and incident on a condenser lens 33 to become a beam 27, and the other is collected through a mirror 25 and 26. The beam 30 is made incident on the optical lens 33. The cutting edge surface 5 or 6 of the diamond tip 1 that is a workpiece is irradiated with a laser beam to create periodic finely processed grooves. When the diamond area is larger than the spot size of the irradiation laser beam (effective area for changing the surface properties), the diamond tip 1 is moved by, for example, the driving table 31 in the moving direction 32 to irradiate the area necessary for the surface property modification. . The same applies to the case where the workpiece is an abacus-shaped diamond cutting edge or a diamond microtome cutting edge.

  The element 29 has a function of relatively changing the optical path lengths of the two laser beams 23 and 28 by adjusting the optical path length until the branched beam 28 reaches the lens. Usually, it is provided separately as shown in FIG. However, if the wavelength is 800 nm, for example, a difference in optical path length between the two laser beams 23 and 28 occurs only by moving the position of the mirror 25 or 26 back and forth by a length of about submicron, so the state of interference changes. . Therefore, in such a case, the mirror 25 and / or the mirror 26 and their moving mechanism (not shown) become the element 29. It is installed so that a fine structure of an appropriate surface can be obtained on the surface of the diamond chip, which is the focused irradiation position of the laser beams 27 and 30 that have passed through the condenser lens 33. The interference action of the ultrashort pulse changes when the two laser beams pass through different optical paths. It is also possible to set the optimum condition by changing the irradiation timing of the two laser beams to the diamond tip and observing the formation state of the diamond tip surface by the interaction between the preceding irradiation and the subsequent irradiation.

  In addition to the near-infrared wavelength, the laser wavelength of the laser oscillator may be a short wavelength laser beam generated by a wavelength conversion technique. A light source that is practically easily available as an industrial laser device capable of forming a striped fine irregular surface having a periodic structure is a solid-state laser beam having an oscillation wavelength of 100 nm to 2000 nm. The condensing lens may be an ordinary spherical lens or aspherical lens, or a condensing optical system using a reflecting mirror, a cylindrical lens, or an optical system using a combination thereof. By changing the angles of the two laser beams 27 and 30 irradiated on the diamond surface, it is possible to change the striped pitch of fine irregularities formed on the surface of the diamond.

  The formation pitch of the striped irregularities is preferably in the range of 5 nm to 3000 nm. The rough groove is preferably about 1/2 to 1/4 of the pitch. The formation direction of the fine uneven stripe pattern can be determined by the relative angle between the direction of the surface formed by the two laser beams 27 and 30 and the installation direction of the diamond. The formation direction of the striped pattern can be selected in accordance with the rake face shape and flank shape of the cutting tool, and the optimum direction can be selected based on the relationship with the ease of chip discharge and the reduction of frictional force.

  The embodiment of the present invention has been described above. Obviously, modifications may be made to the invention without departing from the scope of the invention as set forth in the appended claims.

  Examples of applications of the present invention include ultra-precision cutting, such as aspherical mirrors, lenses or their molds, polygon mirrors, copy drums, aluminum masters such as magnetic storage disks, and tools for hard and brittle materials. It can be used as a high-performance tool and its manufacturing method by applying to the surface of the tool.

The example and operation | movement explanatory drawing of the diamond bit manufactured by laser beam irradiation to which this invention is applied. The figure explaining the shape of a diamond tip. The figure explaining the laser cutter which has a abacus ball-shaped diamond blade edge. The figure explaining the shape of a microtome. The figure of the ultrashort pulse laser irradiation structural example for forming the fine unevenness | corrugation in the diamond-tip surface.

Explanation of symbols

1: Diamond tip 2: Shank of diamond cutting tool to be brazed to the tip 4: Diamond cutting edge portion 5, 6: Cutting edge surface 7: Rake surface 8: Round portion of diamond (ridge line)
9: Flank 10: Work piece 11: Cutting thickness 12: Cutting waste 13, 14: Directional arrow 15: Processing surface 20: Laser pulse oscillator 21: Laser pulse 22: Beam splitting mirror 23, 28: Split Laser beam 24, 25, 26: Mirror 27, 30: Two laser beams that have passed through the condenser lens 29: Element 31: Driving table 32: Moving direction of the driving table 33: Condensing lens 40: Diamond microtome cutting edge 41: Edge line 42 of the blade edge: inclined surface forming the ridge line
44: Slope 43, 45, 46: Side 50: Roller cutter 51: Abacus ball shaped blade 52: Strut 53: Tapered portion 54 of the strut 54: Handle 55: Edge of the ridge 56: Tip 100: Diamond bite

Claims (15)

In a diamond cutting tool with a diamond cutting edge that cuts in contact with the workpiece,
The diamond cutting tool which has the striped fine uneven surface of a periodic structure in the at least 1 contact surface and ridgeline part of the said diamond blade edge which contacts the said workpiece. The diamond cutting tool according to claim 1, wherein the period of the striped fine uneven surface is 5 nm to 3000 nm. The diamond cutting tool according to claim 1 or 2, wherein the diamond cutting edge is a diamond tip having an arcuate blade shape, a straight blade shape, or a triangular blade shape. The diamond cutting tool according to claim 1 or 2, wherein the diamond cutting edge is a diamond tip having an elliptical blade shape, a parabolic blade shape, or a hyperbolic blade shape. The diamond cutting tool according to claim 3 or 4, wherein the diamond chip has a striped fine irregular surface of the periodic structure on a rake face, a flank face, and a ridge line where the flank face and the rake face intersect. The diamond cutting tool is a diamond roller cutter, and the diamond cutting edge has an abacus ball shape, and has a striped fine irregular surface of the periodic structure at a ridge line portion in contact with the workpiece. The diamond cutting tool described. The diamond according to claim 1 or 2, wherein the diamond blade edge is a microtome, and has a ridgeline of the blade edge, an inclined surface that forms the ridgeline, and a stripe-shaped fine irregular surface of the periodic structure on an inclined surface sandwiched between the inclined surfaces. Cutting tools. In a method of manufacturing a diamond cutting tool having a diamond cutting edge for cutting in contact with a workpiece,
A method of manufacturing a diamond cutting tool, comprising: forming a striped fine uneven surface having a periodic structure by irradiating laser light onto a contact surface and a ridge line portion of at least one workpiece of the blade edge after the shape forming process of the blade edge . The said laser beam is a manufacturing method of the diamond cutting tool of Claim 8 which is a laser beam which has strong and weak periodic power distribution by the light interference by irradiation of a femtosecond laser pulse. 9. The method for manufacturing a diamond cutting tool according to claim 8, wherein the laser beam is a laser beam having a strong and weak periodic power distribution due to optical interference caused by irradiation of a laser pulse with a pulse width of 10 fs to 2000 fs. The method of manufacturing a diamond cutting tool according to any one of claims 8 to 10, wherein a period of the striped fine uneven surface of the periodic structure is 5 nm to 3000 nm. The method for manufacturing a diamond cutting tool according to any one of claims 8 to 11, wherein a wavelength band of the laser beam is based on a laser beam having a wavelength spectrum from a near infrared region to an ultraviolet region. The method for manufacturing a diamond cutting tool according to any one of claims 8 to 11, wherein the laser beam has a wavelength of 100 nm to 2000 nm. The method for manufacturing a diamond cutting tool according to claim 12 or 13 , wherein the laser beam is a solid-state laser beam. The diamond according to any one of claims 8 to 14, wherein the laser light is laser light that has passed through a condensing optical system composed of a spherical lens, an aspherical lens, a cylindrical lens and a reflecting mirror, or a combination thereof. Cutting tool manufacturing method.

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