JP2004167632A - Manufacturing method for micro-grinding tool, and micro-grinding tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for micro-grinding tool and provide a micro-grinding tool having at the tip a high accuracy spherical surface or an aspherical surface. <P>SOLUTION: An electrode holding table for formation of a tool installed on a processing machine is furnished with a high accuracy V-groove, and the electrode for formation of the tool shaped accurately in the specified diameter is put in the V-groove accurately, and then a grinding tool material is scanned accurately while a micro electric discharge machining is applied to the electrode, and thereby the micro-grinding tool can be formed accurately. It is favorable that the tool material is sintered diamond. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a micro-grinding tool used for processing an optical element such as a micro-lens array, and a micro-grinding tool.
[0002]
[Prior art]
In the processing of a mold for a micro optical device such as a micro lens array, a tool used from the processing object has a diameter of 300 μm or less, and a spherical surface having a shape accuracy of 1 μm or less at a tool tip for processing a three-dimensional curved surface shape. Alternatively, a tool having an aspherical shape is required.
[0003]
As a conventional method for producing a grinding tool, discharge truing or the like is employed.
[0004]
According to this discharge truing method, for example, as disclosed in Patent Literature 1, it is possible to increase the precision of a tool shape by producing a tool electrode on a machine.
[0005]
[Patent Document 1]
JP-A-63-283861
[Problems to be solved by the invention]
However, it is difficult to machine the tool electrode on the machine.In addition, the tool electrode is required to have low wear during electric discharge machining.However, materials with low electrode consumption such as pure tungsten material have high hardness and high precision. Since it is difficult to process, a problem arises as a method for manufacturing a highly accurate micro-grinding tool. Further, when the tool electrodes are individually manufactured and mounted on a machining machine, there is a possibility that a problem occurs in that a shape error occurs in a tool to be formed due to a relative positioning error between a grinding tool to be manufactured and an electric discharge machining electrode.
[0007]
Further, as a method for producing a fine tool having a diameter of 1 mm or less, grinding or electric discharge machining as shown in FIG. 5 is used. In the electric discharge machining, a fine tool can be formed by rotating the grinding tool 11 and sending it to the block electrode 10 while discharging in the opposite polarity. However, it is difficult to form a blade on a fine tool in any of the processes, and there is a problem that the shape is a simple columnar shape and the processing capability is low as a grinding tool.
[0008]
As described above, as described above, the conventional method has a problem that it is difficult to manufacture a truing electrode with high accuracy, there is a problem that a mounting error of the truing electrode is low, or a grinding ability is low. There are many problems.
[0009]
An object of the present invention is to provide a micro-grinding tool having a high-precision spherical surface or aspherical surface at its tip and excellent in machining ability, and a method of manufacturing the same, in view of the above conventional problems.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a micro-grinding tool according to the present invention is characterized in that a V-groove is formed on a tool-forming electrode holding table installed on a processing machine, and a tool-forming electrode formed into a predetermined diameter. After being set in the V-groove, a grinding tool material is scanned on the tool-forming electrode while performing fine electrical discharge machining, and is formed into the grinding tool.
[0011]
According to the above method, a low-electrode consumable material such as pure tungsten produced with high precision by micro electric discharge machining or the like can be installed with high precision without misalignment with a processing machine. Even if it is, it can be manufactured with high accuracy.
[0012]
Further, when the processing capability of the tool is low, when feeding the grinding tool formed to a predetermined diameter into the groove forming electrode installed on the processing machine into the groove forming electrode, the bottom surface of the grinding tool Alternatively, it is possible to improve the machining ability of the tool by forming a fine groove while performing discharge without rotating the side surface.
[0013]
Further, by using sintered diamond as a tool material, a micro-grinding tool with extremely small tool wear can be obtained even for a high-hardness material such as a cemented carbide due to the high wear resistance characteristics of the tool material.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0015]
(1st Embodiment)
FIG. 1 is a cross-sectional view illustrating a method for manufacturing a micro-grinding tool according to the first embodiment of the present invention. In FIG. 1, 1 is a grinding tool, 2 is a tool forming electrode, 3 is an electrode holder, 4 is a mandrel, 5 is a Z stage, 6 is an XY stage, and 7 is a discharge generating circuit.
[0016]
In the figure, a grinding tool 1 is fixed to a mandrel 4 rotated by a motor, and can be positioned in a rotation axis direction by using a Z stage 5. The tool-forming electrode 2 is fixed on a V-groove formed on an electrode holder 3 installed on an XY stage 6.
[0017]
As shown in FIG. 3, the V-groove of the electrode holder 3 is cut into the electrode holder while rotating the conical shaped sintered diamond tool 9 instead of the grinding tool 1, and is scanned in the horizontal direction. Can be processed. By disposing the tool-forming electrode 2 in the V-groove processed on the machine in this way, the positioning of the tool-forming upper electrode is facilitated, and the axial deviation between the tool-forming electrode and the machine can be extremely reduced. it can.
[0018]
Further, between the grinding tool 1 and the electrode holder 3, a discharge generating circuit 7 composed of an RC circuit capable of generating a discharge pulse of minute energy is electrically connected, and the grinding tool 1 and the tool forming are formed. It is configured so that fine electric discharge machining can be performed with the electrode 2 for use.
[0019]
With the above-described apparatus configuration, discharge truing is performed while rotating the grinding tool 1 while rotating the tool forming electrode 2 while maintaining a predetermined discharge gap. A spherical shape can be produced.
[0020]
Brass is used as the electrode holder material, and as a V-groove processing on the electrode holder, a sintered diamond tool formed at a vertical angle of 90 ° is rotated at 3000 rpm, and the electrode holder is scanned at 20 μm / sec at a cutting depth of 1 μm. Then, a V-groove having a depth of 450 μm was machined, and tungsten having a diameter of 950 μm was placed on the groove as a tool-forming electrode material.
[0021]
As a grinding tool material, a sintered diamond having a diameter of 100 μm was used. The conditions of the electric discharge machining were as follows: the tool rotation speed was 3000 rpm, the capacitance of the capacitor was 10 pF, the voltage was 70 V, the machining atmosphere was electric discharge machining oil, the amount of one cut from the electric discharge detection point at the top of the electrode was 0.5 μm, Was scanned while discharging at a speed of 30 μm / sec. As a result, a micro-grinding tool having a spherical shape with R = 50 μm at the tool tip was obtained.
[0022]
(Second embodiment)
FIG. 2 schematically shows a method for manufacturing a micro-grinding tool for improving the grindability according to the second embodiment. In FIG. 2, the thin plate electrode 8 is installed perpendicularly to the machining machine Z axis, and a discharge circuit is connected between the thin plate electrode and the tool material. Further, by positioning the tool material at a predetermined position and sending the tool material to the thin plate electrode while discharging without rotating, a fine groove can be machined. Positioning of the tool material and the thin plate electrode can be performed by detecting conduction between the tool side surface and the thin plate electrode.
[0023]
A stainless steel tool with a thickness of 30 μm was used as the thin plate electrode material, and a sintered diamond tool with a diameter of 100 μm was used as the grinding tool material. By repeating the feeding process twice by rotating the tool at right angles, a fine groove having a width of 30 μm and a depth of 20 μm as shown in FIG. 4 could be formed.
[0024]
【The invention's effect】
Advantageous Effects of Invention According to the present invention, it is possible to provide a method for manufacturing a micro-grinding tool having a diameter of 1 mm or less, a tip having a spherical or aspherical shape, high precision, and excellent grindability, and a micro-grinding tool. Become.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a method of processing a micro-grinding tool according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a method of processing a fine groove on a micro-grinding tool according to a second embodiment of the present invention. FIG. 3 is a sectional view showing a V-groove machining method according to the first embodiment of the present invention. FIG. 4 is a view showing a micro-grinding tool according to a second embodiment of the present invention. Sectional view showing the tool machining method [Description of reference numerals]
DESCRIPTION OF SYMBOLS 1 Grinding tool 2 Tool forming electrode 3 Electrode holder 4 Mandrel 5 Z stage 6 XY stage 7 Discharge generating circuit 8 Groove forming electrode 9 Conical sintered diamond tool 10 Block electrode 11 Grinding tool

Claims (5)

A V-groove is machined on a tool-forming electrode holding table installed on a processing machine, and a tool-forming electrode formed into a predetermined diameter is installed in the V-groove. Then, a grinding tool material is placed on the tool-forming electrode. A method for producing a micro-grinding tool, wherein the micro-grinding tool is scanned while being subjected to fine electric discharge machining to form the grinding tool. When a grinding tool formed to a predetermined diameter is fed into the groove forming electrode into the groove forming thin plate electrode installed on the processing machine, the grinding tool is discharged without rotating the bottom surface or the side surface of the grinding tool while rotating. A method for processing a micro-grinding tool, comprising forming a groove. 3. The method according to claim 1, wherein the tool material is a sintered diamond. A V-groove is machined on a tool-forming electrode holding table installed on a processing machine, and a tool-forming electrode formed into a predetermined diameter is installed in the V-groove. Then, a grinding tool material is placed on the tool-forming electrode. A micro-grinding tool produced by scanning while micro-discharge machining,
A micro-grinding tool, wherein the diameter of the micro-grinding tool is 300 μm or less. The micro-grinding tool according to claim 4, wherein the tool material is sintered diamond.

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