JPH03178769A - Grinding method and device therefor - Google Patents

Abstract

PURPOSE:To take the mechanical load given to the body to be worked less than the sticking force by the electric force of a particulate and to cause no chipping, etc., by performing the grinding motion to the body to be worked by the particulate sticked to a grindstone blade with the electric force. CONSTITUTION:A grindstone blade 4 formed of a conductive thin plate and the body 9 to be worked are arranged in the water solution 2 mixed with a particulate 7. Electric charge is then exerted between the grindstone blade 4 and water solution 2, the particulate 7 suspended in the water solution 2 is charged and the particulate 7 is sticked to the grindstone blade 4. The layer thickness of the particulate 7 is aligned constant by a layer thickness regulating means 10 and the body 9 to be worked is ground by performing a relative movement in the space with the body 9 to be worked.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to surface grinding, form grinding, and other grinding methods and apparatus thereof, which utilize the electrophoretic phenomenon of fine particles suspended in a liquid phase. The present invention relates to a grinding method and apparatus suitable for grinding not only general metal materials but also hard, brittle, and shock-resistant workpieces.

BACKGROUND OF THE INVENTION Conventionally, grinding wheels have been used to process dicing and slicing of hard, brittle, impact-resistant materials such as silicon, ferrite, ceramics, and glass.

Problems to be Solved by the Invention In the case of mechanical processing using a grinding wheel, if the workpiece is a hard, brittle, impact-resistant material such as silicon, ferrite, ceramics, or glass, Chipping tends to occur on objects, making it difficult to perform high-precision processing.

Means for Solving the Problems A grindstone blade formed of a conductive thin plate or a plate material with a certain thickness and a workpiece are placed in an aqueous solution containing fine particles, and the grindstone blade and the workpiece are disposed in an aqueous solution containing fine particles. The fine particles suspended in the aqueous solution are charged by applying an electric charge to the aqueous solution to adhere the fine particles to the grinding wheel blade, and the layer thickness of the fine particles is made constant by a layer thickness regulating means. The workpiece is ground by relative movement between the grinder and the workpiece.

The device also includes: an aqueous solution holding means for holding an aqueous solution containing fine particles; a disc-shaped grindstone blade that is disposed in the aqueous solution and rotates; and a workpiece facing the grindstone blade. It was constructed by a power supply means for applying a voltage between the grindstone blade and the aqueous solution, and a layer thickness regulation means for regulating the layer thickness of fine particles attached to the grindstone blade to be constant.

Action The grinding operation on the workpiece is performed by fine particles attached to the grinding wheel blade by electric force, so the mechanical load applied to the workpiece is less than the adhesion force due to the electric force of the fine particles, and the fine particles are attached to the workpiece by electric force. Grinding is done by colliding with an object, so it can be processed easily.This allows high precision processing without chipping, and the processing width can be controlled by controlling the layer thickness of fine particles. This can be done by regulating the layer thickness to a constant level, and the adhesion of fine particles to the grinding wheel blade can be easily done by utilizing the electrophoresis phenomenon that occurs when fine particles suspended in an aqueous solution are charged. It is possible.

Example An embodiment of the present invention will be described based on the drawings.

First, to aid understanding, the principle will be explained based on Figure 2.

An alkaline aqueous solution 2 mixed with colloidal silica having a particle size of about 10 to 20 nm is stored in a container 1. A brass type grindstone blade 4 held by a spindle 3 is placed in this aqueous solution 2. This grindstone blade 4 has a diameter of 60 mm and a thickness of about 300 to 400 ILm. A voltage is applied to the grindstone blade 4 and the aqueous solution 2 by an external power source 5 and an electrode 6 as power source means. Therefore, the fine particles 7 made of colloidal silica adhere to the grindstone blade 4 in a form corresponding to the electric field distribution.

Next, an abutment 8 is provided in the container 1, and this abutment 8
A workpiece 9 is attached to. A layer thickness regulating member 10 made of glass is formed on one surface of the workpiece 9 so that the layer thickness of the fine particles 7 adhering to the grindstone blade 4 is constant, and the interval can be freely adjusted.

Therefore, the fine particles 7 adhere to the periphery of the grindstone blade 4 due to the electrophoretic phenomenon. The adhered fine particles 7 are shaped by the layer thickness regulating member 10 as the grindstone blade 4 rotates to a constant thickness, and come into contact with the workpiece 9 to be ground. That is, groove processing is performed. At this time, grindstone blade 4
Since the material does not come into contact with the workpiece 9, there is no mechanical stress and processing is performed with extremely high precision.

During this processing, the adhesion shape of the fine particles 7 is destroyed, but
Since the grindstone blade 4 is rotating, adhesion is progressing in parts not involved in machining, and continuous machining is possible.

Next, a specific example of the device will be explained based on FIGS. 2 to 6. Components that are the same as those described with reference to FIG. 1 are designated by the same reference numerals, and their description will be omitted.

First, the spindle 3 is arranged horizontally, and the grindstone blade 4 is held at the tip of the spindle 3 by a holder 11. A cover 12 is provided with only the lower part of the grindstone blade 4 open, and the cover 12 is provided with an aqueous solution passage 13 as an aqueous solution holding means disposed along the periphery of the grindstone blade 4. There is. A pipe 14 is connected to this aqueous solution passage 13, and this pipe 1
4 is connected to an aqueous solution supply section (not shown).

A layer thickness regulating member 10 is provided below the grindstone blade 4 . This layer thickness regulating member 10 is
It is a rotating body having an annular slit 15, and is attached so as to rotate with the rotation of the grindstone blade 4.

A table 16 is provided below the grindstone blade 4 mounted in this manner, and a permanent chuck 17 is mounted on this table 16. Ingredients 18
is attached, and a wall 19 of a constant height is provided around this jig 18 to form a pool 20.

In such a configuration, during grinding, the jig 1
A workpiece 9 is set on top of the workpiece 8. And pipe 14
The grindstone blade 4 is rotated while supplying the aqueous solution 2 from the grinding wheel. As a result, the aqueous solution 2 flows down around the grindstone blade 4 via the aqueous solution passage 13, but the fine particles 7 adhere to the grindstone blade 4 in the process. The fine particles 7 attached to the grindstone blade 4 are shaped to have a constant thickness by the layer thickness regulating member 10 that rotates as the grindstone blade 4 rotates.

However, in the processing section, the aqueous solution 2 is in the pool 20.
is stored, and the fine particles 7 attached to the grindstone blade 4 in the aqueous solution 2 contact the workpiece 9 and perform a grinding operation. Furthermore, although the aqueous solution 2 flows out from the pool 20, the aqueous solution 2 is collected at a fixed location by a collection means (not shown).

Next, the results of an experiment using a metal blade without diamond as the grindstone blade 4 will be explained. The purpose of this experiment was to confirm the adhesion of silica to the grinding wheel blades rotating at high speed and the resulting grinding ability.

First, the grinding conditions are as follows.

Blade: Bronze metal blade Notch:
1.1mm Feed rate: 2.5mm/min Grinding fluid: Snowtex 30 (Product name) Grinding fluid flow rate + 7Q/min Sample: Silicon wafer Rotation speed: 3000ppm Load voltage: 30V In this case, the load voltage is O At that time, the blade was damaged due to direct contact between the blade and the silicon wafer, and the cut could not be made. On the other hand, as mentioned above, the load voltage is 30
At V, good grinding was possible and grooving was possible, and there was no metallic sound or damage to the blade that occurred when no voltage was applied.

As a result, it was confirmed that silica adhered to metal blades that were rotating at high speed, and that they had the ability to grind.

Next, the results of an experiment using a diamond blade will be explained. Since there is a risk of the blade being damaged due to peeling off of the abrasive grains in the metal blade described above, dicing was performed using a diamond blade under the following processing conditions.

Blade: SD50ON75M D 70mm H40mm TO, 1mm: 0
．． 2mm: 5mm/min Snowtex 30 (Product name) 7Q/min Soda glass 3000rpm Grinding fluid flow rate: Sample: Rotation speed: Cutting feed rate Grinding fluid load voltage: O■, 30V Even with such a diamond blade, the bonding material When it has conductivity, the same electrodeposition phenomenon of silica as in the case of a metal blade occurs. By applying a voltage, a surface with no chipping was obtained, but sagging occurred on the processed cross section. This is thought to be because the deposition rate is faster than the rate at which the silica falls off, so extra silica adheres around the blade, causing the silica to sag.

In order to eliminate this sagging, it was thought that it was necessary to increase the falling rate of the abrasive grains, so an experiment was conducted with the depth of cut set to 0.5 mm among the processing conditions.

As a result, most of the sag disappeared, but a lot of chipping became visible. This seems to be due to the fact that the rate at which the abrasive grains adhered was too low compared to the rate at which they fell off.

Therefore, in order to increase the adhesion speed, the load voltage was increased to 6
A cut of 0.5 mm was made at 0V. As a result, grooves with significantly suppressed sagging and chipping were obtained. The measurement results of the amount of chipping at this time are shown in FIG.

Here, the conditions under which such measurement results were obtained are shown in FIG. First, for a 21 mm square sample, a total of 20 measurement points were set at 1 mm intervals. The measured length at each measurement point is 0,
4 mm, and at each measurement location, the largest width chips (a, b in FIG. 8) among the chippings existing therein were accumulated at l locations on both end faces of the groove.

From the above, it is presumed that there is an optimal condition for this process, and that is when the falling rate and the deposition rate of silica become the same. Furthermore, under these conditions, it is thought that processing with almost no sag or chipping is possible.

Effects of the Invention As described above, the present invention disposes a grindstone blade formed of a conductive thin plate or a plate material with a predetermined thickness and a workpiece in an aqueous solution containing fine particles, and Applying an electric charge between the grinding wheel blade and the aqueous solution to charge the fine particles suspended in the aqueous solution, causing the fine particles to adhere to the grinding wheel blade, and making the layer thickness of the fine particles constant by a layer thickness regulating means. Since the workpiece is ground by making the workpiece move relative to the workpiece, the grinding operation on the workpiece is performed by fine particles attached to the grindstone blade by electric force. The mechanical load applied to the object is less than the adhesion force due to the electric force of the particles, and the grinding is done by the particles colliding with the workpiece, so it can be processed without difficulty, thereby preventing chipping etc. Machining can be performed with high precision without generation of particles, and the processing width can be controlled using a layer thickness regulating means that keeps the layer thickness of fine particles constant. This can be easily carried out by utilizing the electrophoresis phenomenon that occurs when suspended fine particles are charged, and the apparatus includes an aqueous solution holding means for holding an aqueous solution containing mixed fine particles, and an aqueous solution holding means for holding an aqueous solution containing mixed fine particles. a disc-shaped grindstone blade formed by a rotating thin plate disposed therein, a workpiece facing the grindstone blade, and a power supply means for applying a voltage between the grindstone blade and the aqueous solution; This can be easily formed by using a layer thickness regulating means that makes the layer thickness of the fine particles adhered to the grindstone blade constant.

[Brief explanation of drawings]

Fig. 1 is a longitudinal side view showing the principle of the present invention, Fig. 2 is a longitudinal side view showing an embodiment of the invention, Fig. 3 is a front view of a part thereof, and Fig. 4 is a layer thickness regulating member. 5 is a side view of the table portion, FIG. 6 is a plan view thereof, FIG. 7 is a distribution diagram of chipping, and FIG. 8 is an explanatory diagram showing a method of measuring chipping. l. ...Aqueous solution holding means, 2..Aqueous solution, 4.. Grinding wheel blade, 5.. Power supply means, 7.. Fine particles, 9.. Workpiece, .... Layer thickness regulating member applicant Co., Ltd. Okamoto Machine Tool Manufacturing Co., Ltd. Yasuhiro Tani Hin L: ・ 3 "Next" ・ ° A motion regulation ll laborious talent

Claims (1)

[Claims] 1. A grindstone blade formed of a conductive thin plate and a workpiece are disposed in an aqueous solution containing fine particles, and an electric charge is applied between the grindstone blade and the aqueous solution. , the fine particles suspended in the aqueous solution are charged, the fine particles are attached to the grindstone blade, the layer thickness of the fine particles is made constant by a layer thickness regulating means, and the fine particles are moved relative to the workpiece. A grinding method characterized in that the workpiece is ground by: 2. The grinding method according to claim 1, wherein the grindstone blade is a metal blade. 3. The grinding method according to claim 1, wherein the grindstone blade is a diamond blade. 4. A grindstone blade formed of a conductive plate material of a certain thickness and a workpiece are placed in an aqueous solution containing fine particles, and an electric charge is applied between the grindstone blade and the aqueous solution. By electrifying fine particles suspended in an aqueous solution and adhering the fine particles to the grinding wheel blade, the layer thickness of the fine particles is made constant by a layer thickness regulating means, and the fine particles are caused to move relative to the workpiece. A grinding method characterized in that the workpiece is ground. 5. an aqueous solution holding means for holding an aqueous solution containing fine particles; a disc-shaped grindstone blade that is disposed in the aqueous solution and rotates; and a workpiece facing the grindstone blade;
A grinding device comprising: a power supply means for applying a voltage between the grindstone blade and the aqueous solution; and a layer thickness regulation means for regulating the layer thickness of fine particles attached to the grindstone blade to be constant.