JP2012125863A - Radius end mill of single-bladed structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radius end mill that obtains processing accuracy with an ultraprecise level of 10 nm or lower.SOLUTION: The radius end mill includes: a tool shank; and a diamantine single-bladed tip mounted to the tool shank.

Description

  The present invention relates to a radius end mill. In particular, the present invention relates to a radius end mill that can be used when cutting a mold for molding a lens array from silicon resin.

  The straight end mill shown in FIG. 3 is an excellent tool for machining a flat bottom surface, but has a drawback that chipping (breakage) of the cutting edge is likely to occur. On the other hand, in the ball end mill shown in FIG. 4, chipping of the cutting edge is difficult to occur, but the flat bottom surface cannot be processed.

  Therefore, a tool called a radius end mill as shown in FIG. 5 has been developed. The tool is a tool in which a straight end mill and a ball end mill are fused, can process a flat bottom surface, and does not easily cause chipping of the cutting edge.

  A conventional radius end mill employs a two-blade structure or a four-blade structure as shown in FIG. 5 from the viewpoint of tool manufacturing convenience and machining efficiency.

  However, with a radius end mill that employs a two-blade structure or a four-blade structure carbide tip, sufficient edge shape accuracy cannot be obtained, and an ultra-precise level machining accuracy of 10 nm or less cannot be realized. The inventor has repeatedly studied with the tool manufacturer, and has found that a diamond end radius end mill having a single-blade structure can achieve an ultra-precise level of processing accuracy of 10 nm or less.

  The present invention has been created based on the above findings. An object of the present invention is to provide a radius end mill capable of realizing processing accuracy of an ultra-precise level of 10 nm or less, and in particular, a radius end mill that can be used when cutting a mold for forming a lens array from a silicon resin. Is to provide.

  The present invention is a radius end mill comprising a tool shank and a diamond single-blade tip attached to the tool shank.

  According to the present invention, by adopting a single-blade structure with a single-blade chip made of diamond, it is possible to realize an ultra-precise level processing accuracy of 10 nm or less.

  Preferably, the single blade tip has a cutting edge region exceeding 90 °. Thereby, the effective escape of a blade edge | tip area | region is realizable. In particular, the clearance on the bottom side is preferably about 0.5 ° to 1.0 °.

  Preferably, the tool shank is made of tungsten carbide, and the single blade tip is silver brazed to the tool shank.

  Preferably, the radius end mill is used for cutting a mold for molding a lens array from silicon resin.

  Moreover, the present invention is a processing machine comprising a radius end mill having any one of the above characteristics and a control unit that controls a tool trajectory of the radius end mill.

  Further, the present invention is a processing method using the processing machine, based on a step of processing a dummy workpiece, a step of measuring a processing shape of the dummy workpiece, and a measurement result of the processing shape of the dummy workpiece A machining method comprising a step of correcting a tool locus of the radius end mill and a step of machining a workpiece to be machined according to the corrected tool locus. In particular, the present invention is a mold processing method for forming a lens array using the processing machine, the step of processing a copper dummy work, and the step of measuring the processing shape of the dummy work And a step of correcting the tool trajectory of the radius end mill based on the measurement result of the machining shape of the dummy workpiece, and machining a workpiece made of nickel alloy such as copper or nickel phosphorus to be machined according to the corrected tool trajectory. A processing method comprising the steps of:

  According to the present invention, by adopting a single-blade structure with a single-blade chip made of diamond, it is possible to realize an ultra-precise level processing accuracy of 10 nm or less.

It is a schematic sectional drawing of the radius end mill of one embodiment of this invention. It is a schematic flowchart which shows the processing method of one embodiment of this invention. It is the schematic of a common straight end mill. It is the schematic of a common ball end mill. It is the schematic of a common radius end mill.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic sectional view of a radius end mill according to an embodiment of the present invention. As shown in FIG. 1, the radius end mill 10 of the present embodiment includes a tool shank 11 connected to a main shaft 21 of a processing machine 20, and a single-crystal diamond single-chip tip 12 attached to the tool shank 11. It is equipped with. In the present embodiment, the tool shank 11 is made of tungsten carbide, and the single blade tip 12 is brazed to the tool shank 11 with silver. The single blade tip 12 may be made of sintered diamond instead of single crystal diamond.

  As shown in FIG. 1, the single-blade tip 12 has a cutting edge region (region of R blade and bottom blade) exceeding 90 ° (preferably exceeding 90.5 ° or 91 °). . Thereby, effective escape of the cutting edge region is realized. In particular, the clearance on the bottom side is preferably about 0.5 ° to 1.0 °.

  The main shaft 21 of the processing machine 20 is position-controlled by three orthogonal axes by the control unit 25, and as a result, the tool path of the radius end mill 10 is controlled.

  The method for fixing the single-blade tip 12 to the tool shank 11 is not limited to silver brazing, and other brazing methods may be employed.

  Next, a method for cutting a mold for molding a lens array from a silicon resin using the processing machine 20 of the present embodiment will be described with reference to FIG.

  First, a copper dummy work is prepared (STEP 1). Then, while controlling the position of the spindle 21 relative to the dummy workpiece, the dummy workpiece is processed into a desired shape by the radius end mill 10 (STEP 2). Then, the machining shape of the dummy workpiece is measured (STEP 3).

  If the measured machining shape of the dummy workpiece is completely consistent with the desired shape, which is the machining command, under the control program (control system) as it is, the actual machining object such as copper or nickel such as nickel phosphorus Alloy workpieces can be processed. However, usually, the measured machining shape of the dummy workpiece has a slight deviation (error) from the desired shape, which is a machining command.

  Therefore, the control unit 25 corrects the tool trajectory of the radius end mill 10 based on the measurement result of the machining shape of the dummy workpiece (STEP 4). Then, according to the corrected tool trajectory, a workpiece made of copper or nickel alloy such as nickel phosphorus is processed (STEP 5).

  By the method as described above, a mold for forming a silicon lens array can be processed with extremely high accuracy. The above STEP1 to STEP5 are preferably performed not only at the start of processing but also between processing. For example, when machining is continued for several days, it is preferable to perform STEP 1 to STEP 5 every 12 hours to compensate for a control program (control system) against changes over time in the machining environment.

  Next, an actual processing example will be described. Here, an array (matrix) of lenses having a component diameter of 2 mm, a lens diameter of 0.866 mm, a lens shape curvature R = 0.5 mm, a convex spherical surface, and a lens height of 0.25 mm was processed.

Since the removal volume is as large as 0.703 mm ³ , the ball end mill cannot be put to practical use because the processing time is long. Further, in the ball end mill, it is necessary to reduce the so-called pick feed to about 0.005 mm when processing the bottom plane, which is not practical.

  Therefore, for such processing examples, a radius end mill according to the present invention was manufactured with an offset diameter of 0.15 mm and a cutting edge R of 0.10 mm. That is, the tool radius was 0.25 mm (tool diameter was 0.50 mm).

  When a pick feed was set to 0.05 mm and a workpiece made of copper or nickel alloy such as nickel phosphorus was processed into a lens array molding die, Ra of 5 nm or less could be achieved for the bottom plane. Moreover, being able to set the pick feed to 0.05 mm means that the cutting length is shortened, that is, tool wear is also reduced.

10 Radius end mill 11 Tool shank 12 Single blade tip 20 Processing machine 21 Spindle 25 Control unit

Claims (7)

Tool shank,
A single blade tip made of diamond attached to the tool shank;
A radius end mill characterized by comprising: 2. The radius end mill according to claim 1, wherein the one-blade tip has a cutting edge region exceeding 90 °. The tool shank is made of tungsten carbide,
3. The radius end mill according to claim 1, wherein the one-blade tip is silver-brazed to the tool shank. The radius end mill according to any one of claims 1 to 3, wherein the radius end mill is used for cutting a mold for molding a lens array from a silicon resin. Radius end mill according to any one of claims 1 to 4,
A control unit for controlling the tool path of the radius end mill;
A processing machine characterized by comprising: A processing method using the processing machine according to claim 5,
A process of processing a dummy workpiece;
Measuring the machining shape of the dummy workpiece;
Correcting the tool trajectory of the radius end mill based on the measurement result of the machining shape of the dummy workpiece;
Machining the workpiece to be machined according to the corrected tool path;
A processing method characterized by comprising: A mold processing method for molding a lens array using the processing machine according to claim 5,
A process of processing a copper dummy work;
Measuring the machining shape of the dummy workpiece;
Correcting the tool trajectory of the radius end mill based on the measurement result of the machining shape of the dummy workpiece;
Processing a workpiece made of copper or nickel alloy such as nickel phosphorus according to the corrected tool trajectory;
A processing method characterized by comprising:

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