JP2000198012A - Working method of material hard in cutting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently work a material hard in cutting such as monocrystalline silicon by using a machine tool comprising an end mill-shaped tool mounted on a non-contact type spindle, and determining a specific cutting depth. SOLUTION: An X-axis mechanism 12 and a Y-axis mechanism 13 are respectively slidable in the lateral direction and the longitudinal direction, and a table 18 placed on the X-axis mechanism 12 is moved. A Z-axis mechanism is longitudinally slidrelative to a workpiece 15 on the table 18. An air bearing- type spindle mechanism 16 as a non-contact type spindle is mounted in this Z-axis mechanism. This spindle mechanism 16 comprises a diamond electro plated tool of a ball end mill as one kind of the end millshaped tools, as a tool 17. A cutting quantity (cutting depth) in the depth direction of a material to be cut is controlled within a range between 0.0001 mm and a diameter of the endl mill-shaped tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for machining hard-to-cut materials using a machine tool having a main shaft of a non-contact type bearing.

[0002]

2. Description of the Related Art Conventionally, new fine ceramic materials such as single crystal silicon, silicon nitride, silicon carbide, alumina and zirconia, ultra-high alloy materials such as tungsten carbide (WC), and difficult-to-cut materials such as glass have high hardness. It is known that machining is difficult due to high brittleness and the tool life is extremely shortened during machining. For this reason, machining with a general machine tool such as a machining center or a turning center has hardly been performed due to economical tool life. In a method using such a general machine tool, when a dare to process a difficult-to-cut material, a grindstone is used, and a high-pressure coolant device, a truing device, a treshing device, and the like for processing with a grindstone are expensive. Equipment had to be prepared. However, even if such an apparatus is prepared and processed, the processing efficiency is not good, and it has not necessarily reached a practical level. In addition, it is necessary to rotate the spindle at a high speed, and the physical life of the bearing used for the spindle often shortens the life of the spindle itself.

Conventionally, a jig grinder has been used for processing these difficult-to-cut materials. The machine specifications in the processing using the jig grinder are specifications in consideration of the processing purpose and are expensive, so that it is difficult to easily process the above difficult-to-cut materials. In addition, as a conventionally known processing method of a difficult-to-cut material, processing using a surface grinder is known.
In this method, the workpiece is placed on a table, the table is moved in parallel on a plane, and the tool is shaped according to the desired shape to be ground. Had been processed. With such a processing method, it is difficult to efficiently process a difficult-to-cut material into a three-dimensional shape.

[0004]

As described above, it is known that hard-to-cut materials have high hardness and the tool life is extremely short during machining. Was said to be difficult to process. For this reason, it has been demanded to provide an efficient processing method of the above-mentioned difficult-to-cut material using the function of a general machine tool. In addition, it has been demanded that such an efficient processing method can efficiently provide a processed product from a difficult-to-cut material to the market.

The present invention has been made in view of the above circumstances, and has as its object to provide an efficient method for processing difficult-to-cut materials using the functions of a general machine tool.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method for machining hard-to-cut materials, comprising a non-contact bearing main shaft and a numerical controller having three or more control shafts. Using a machine tool, attach a small-diameter end mill-shaped diamond electrodeposited or CBN electrodeposited tool to the main spindle of the machine tool, and set the numerical control device to cut the first control axis by 0.0001 mm to about the end mill. Control to the amount between the tool diameter of the small-diameter tool, and also set to control the positioning or contour control of the control axis including the first control axis, three-dimensional machining the difficult-to-cut material while rotating the main spindle, With this configuration, the processing efficiency of difficult-to-cut materials is improved. In addition, the hard-to-cut material is a single crystal silicon material, a silicon nitride material, a silicon carbide material, a new fine ceramics material, a configuration characterized by being one of a cemented carbide material or a glass material, We decided to provide difficult-to-cut materials to the market efficiently. Further, the main shaft of the non-contact type bearing is an air bearing type or a magnetic bearing type main shaft, and the life of the main shaft is extended.
Further, the setting of the positioning control or the contour control is configured such that the one-edge feed amount of the small-diameter tool is 0.0001 to 0.2 mm, and the processing efficiency of difficult-to-cut materials is enhanced. Further, the setting of the rotation of the spindle is performed by setting the number of rotations to 5,
000 to 150,000 rpm to extend the life of the tool.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a conceptual diagram of a machine tool used for the processing method according to the present invention. The machine tool 10 is controlled by a numerical controller 11, and three control axes, an X-axis mechanism 12, a Y-axis mechanism 13, and a Z-axis mechanism 14, are prepared.

The X-axis mechanism 12 and the Y-axis mechanism 13 are mechanisms that slide left and right and back and forth, respectively.
The structure is such that a table 18 installed on the shaft mechanism 12 is moved. The Z-axis mechanism 14 is a mechanism that slides up and down with respect to the workpiece 15 on the table 18.
An air bearing type spindle mechanism 16 is provided in the Z axis mechanism as a non-contact type spindle. As the tool 17, a diamond electroplated tool of a ball end mill, which is a kind of end mill tool, is mounted on the spindle mechanism 16.

The structure of the air bearing type spindle mechanism 16 is shown in FIG.
Is shown in In FIG.
An AC motor 22 is attached, and the main shaft 21 is integrally attached to the AC motor 22. Spindle 21
Are the aerostatic thrust bearing 23 and the radial bearing 2
4 and the AC motor 22
Are supported integrally with the rotor 28 in a completely floating state inside the housing.

The main shaft mechanism of such an air bearing can be adapted to continuous high-speed rotation of several tens of thousands to several hundreds of thousands of rotations due to low frictional resistance. In addition, the rotation accuracy of the main shaft is improved, and an accuracy of a runout accuracy of 0.5 microns or less is realized. Such good performance is realized by supplying an air pressure of about 0.5 kg / cm 2 to a gap of about 1/100 mm in the thrust bearing 23 and the radial bearing 24.

Next, the diamond electrodeposition tool used in the present invention will be described. This tool can be produced by electrodeposition using powdered or powdered diamond crystals, whereas conventional diamond tools require a number of relatively large crystals depending on the diameter of the tool. Are better. Further, it can easily cope with various tool diameters. For this reason, it is possible to increase the range of tool selection without much consideration of the economical aspect of tool use when machining difficult-to-cut materials.

Next, machining of an end mill-shaped tool will be described. It is known that the cutting resistance of this tool sharply increases according to the cutting amount (cutting amount) in the depth direction of the material to be cut, but the cutting resistance for one blade feed amount increases relatively slowly. ing. Feed rate F (mm / min),
Tool rotation speed S (RPM), number of tool blades N, feed amount per blade H
The relational expression between (mm / min) is represented by the relational expression of H = F / SN. The cutting conditions are set in relation to the machining program set in the numerical controller. Therefore, in order to increase the machining efficiency based on the above-mentioned contents, it is sufficient that the setting of the machining program is adjusted according to the material to be cut, and generally, the rotation speed of the main spindle is appropriately increased.

Next, an example of actual processing in the above embodiment will be described. In the following embodiments, a vertical numerical control milling machine ASV40 manufactured by Toshiba Machine Co., Ltd. using a machine having an air bearing type spindle as a machine tool, and a numerical control device manufactured by Toshiba Machine Co., Ltd. TOSNUC-888
Here is an example using types. Regarding the shapes to be machined in the following examples, the outline is shown in FIG. 3 for the con-lot and the outline is shown in FIG. 4 for the grooving. In FIG. 3, the size of the material is about 100 × 60 × 30 mm, and the depth of the processed part of the con-lot shape is about 12 mm.
. Further, the increase in the depth direction is shown as an Ad value, and the increase in the width direction is shown as an Rd value.

(Embodiment 1) In this embodiment, a single-crystal silicon lot is processed as a workpiece. A water-soluble coolant is used for this processing, and the processing conditions are as follows. Spindle rotation speed: 20,000 RPM Spindle feed speed: 236 mm / min Roughing cut depth: Ad 0.05 mm Rd 0.1 mm Finishing cut depth: Ad 0.04 mm Rd 0.04 mm Tool: diamond electrodeposition tool Tool diameter 1.0 mm Particle size 200 Tool model number BIR01 (manufactured by FSK) In this example, roughing was performed for 1 hour and 25 minutes, and finishing was performed for 46 minutes. The tool held up to the final cutting with a single tool.

(Embodiment 2) In this embodiment, an alumina conlot is processed as a workpiece. In this process, a water-soluble coolant is used. The processing conditions are as follows. Spindle rotation speed: 20,000 RPM Spindle feed rate: 118 mm / min Roughing cutting depth: Ad 0.05 mm Rd 0.1 mm Finishing cutting depth: Ad 0.04 mm Rd 0.04 mm Tool: Diamond Electron Attached tool Particle size 600 Tool model number AAR05 (manufactured by FSK) In this example, roughing was 2 hours and 51 minutes, and finishing was 1 hour and 28 minutes.

(Embodiment 3) This embodiment is an example in which grooving of glass is performed as a workpiece. Uses water-soluble coolant. The processing conditions are as follows. In the processing of FIG. 4, the outer diameter of the processing groove is 12 mm, and the depth of the processing groove is about 2 mm. The width of the groove to be processed is 0.4 mm. Helical processing was used. Spindle rotation speed: 20,000 RPM Spindle feed speed: 200 mm / min Helical lead: 0.0046 mm Tool: diamond electrodeposited tool Grain size 600 Tool model number AAR05 (manufactured by FSK) In this example, machining time is 1 hour 28 Minutes. The tool held up to the final cutting with a single tool.

(Embodiment 4) In this embodiment, grooving of alumina is performed as a workpiece. Uses water-soluble coolant. In the processing of FIG. 4, the outer diameter of the processing groove is 12 mm, and the depth of the processing groove is about 2 mm.
The width of the groove to be processed is 0.4 mm. Helical processing was used. The processing conditions are as follows. Spindle speed: 20,000 RPM Spindle feed rate: 150 mm / min Helical lead: 0.006 mm Tool: Diamond electrodeposited tool Grain size 600 Tool model number AAR05 (manufactured by FSK) In this example, the machining time is 3 hours 43 Minutes. The tool held up to the final cutting with a single tool.

In the above-described embodiment, an example in which a diamond electrodeposition tool is used as an electrodeposition tool has been described. However, a CBN electrodeposition tool (a cubic boron nitride electrodeposition tool) is used instead of a diamond electrodeposition tool. Is also good. The same advantages of the CBN electrodeposited tool (cubic boron nitride electrodeposited tool) as compared with the conventional CBN tool (cubic boron nitride nitride tool) can be explained. The advantage of these new tools comes from the fact that they are electrodeposited.

In the above-described embodiment, an air bearing type machine tool has been described as the non-contact type spindle, but a magnetic bearing type machine tool may be used as the non-contact type spindle. In this case, increasing the strength of the magnet has the potential of a spindle having high cutting rigidity.

[0020]

As described above, according to the present invention, a non-contact type spindle is used, a machine tool equipped with an end mill-shaped tool is used, and an appropriate cut amount is set.
It is possible to provide an efficient processing method of a difficult-to-cut material such as single crystal silicon, and efficiently provide a processed product from the difficult-to-cut material to the market.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing an outline of an air bearing used in the embodiment of the present invention.

FIG. 3 is a view showing the shape of a conlot processed in an example of the present invention.

FIG. 4 is a diagram illustrating a shape of a groove cutting process performed in the example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Machine tool 11 Numerical controller 12 X-axis mechanism 13 Y-axis mechanism 14 Z-axis mechanism 15 Workpiece 16 Spindle mechanism 17 Diamond electrodeposition tool 18 Table 20 Housing 21 Main shaft 22 AC motor 23 Thrust bearing 24 Radial bearing 28 Rotor

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroyuki Shirai 2068-3 Ooka, Numazu-shi, Shizuoka Prefecture F-term in Numazu Works, Toshiba Machine Co., Ltd. 3C022 AA01 AA09 AA10 KK01 KK06 QQ00

Claims (5)

[Claims] In a method of processing hard-to-cut material, a machine tool having a numerical control device having a main shaft of a non-contact bearing and having two or more control shafts is provided, and the main shaft of the machine tool is provided with an end mill-shaped machine tool. A small-diameter tool which has been subjected to diamond electrodeposition or CBN electrodeposition is attached, and the cutting depth of each control shaft is controlled to a value between 0.0001 mm and approximately the tool diameter of the end mill-shaped small diameter tool. The numerical control device is set to control the positioning of two or more axes or the contour control of two or more axes at the same time, and the difficult-to-cut material is processed by the machine tool with the numerical control device while rotating the main spindle. Processing method for difficult-to-cut materials. 2. The processing method according to claim 1, wherein the hard-to-cut material is any one of a single-crystal silicon material, a silicon nitride material, a silicon carbide material, a new fine ceramic material, a cemented carbide material, and a glass material. A method for processing difficult-to-cut materials, characterized in that 3. A method for processing a hard-to-cut material product according to claim 1, wherein said main shaft of said non-contact type bearing is a main shaft of an air bearing type or a magnetic bearing type. 4. The numerical control device according to claim 1, wherein the setting of the numerical control device is such that the feed amount per blade or the feed amount per rotation of the small-diameter tool is 0.0001.
From 0.2 mm to 0.2 mm. 5. The method according to claim 1, wherein the setting of the rotation of the main shaft is performed by setting the number of rotations from 3,000 to 15
A method for processing a hard-to-cut material, wherein the speed is set to 000 rpm.