JPS5926425B2 - Electrolytic grinding method for non-conductive materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrolytic grinding using a conductive grindstone.

In recent years, not only excellent materials have been developed, but processing methods for grinding and cutting these materials have also been developed.

Recently, there has been an increasing reliance on electrical discharge machining, which uses electrical energy, as a method for machining difficult-to-cut materials such as cemented carbide.

However, since both methods are processing methods that assume electrical conductivity, they are particularly difficult to handle when machining non-conductive, difficult-to-cut materials such as ceramics, and are limited in the scope of use of electrical discharge machining. I had no choice.

The present invention was made to improve the above points, and an object of the present invention is to provide an electrolytic grinding method that can process even non-conductive hard materials with high precision and in a short time. . Next, an example will be described.

<A> Grinding wheel (1) Disc body Grinding disc body 1 is a commercially available product made by baking and hardening particles of green carborundum, white arundum, bink arundum, silica, etc. using a suitable binder.

The particles constituting the disc body 1 may be made of materials other than those mentioned above, as long as they have excellent insulation and wear resistance.

A shaft hole 2 is formed in the center of the disc body 1, and a current-carrying cylinder 3 is provided on the inner peripheral surface of the shaft hole 2. A donut-shaped current collecting plate 4 is provided, which contacts the current-carrying cylinder 3 at the center of the side surface of the main body 1. Form.

The current-carrying cylinder 3 and the current collecting plate 4 are made of a known metal having excellent conductivity.

An end groove is carved in the transverse direction on the curved end surface of the disc main body 1, and this groove and a side groove communicating with the current collector plate 4 are formed on the side surface.
Carve at equal or uneven intervals.

The insides of both grooves are filled with a conductive material such as an alloy of silver, copper, and nickel to form a conductive band 10 and a current-carrying path 12 that connects the conductive band 10 and the current collector plate 4 .

The portion of the end curved surface of the main body 1 where the conductive band 10 is not formed forms the grinding band 11 as it is.

As mentioned above, the grindstone used in the grinding method of the present invention can be used as long as it forms the polishing zone 11 and the discharge zone 10 alternately on the curved end surface.

<mouth> Voltage waveform A constant alternating current voltage is supplied between the material M and the grindstone 1.

That is, the present invention is characterized in that an alternating current voltage is applied between the non-conductive material M and the grindstone 1 having the above structure.

Next, the implementation method will be explained.

Electrodes are connected from a voltage supply device E to the grinding wheel 1 and a non-conductive material M (for example, Si3N4) to be ground, and an electrolytic solution for electrolytic grinding is supplied.

As the electrolytic solution, for example, a rust-preventing solution manufactured by Johnson Co., Ltd. to which 0.5 to 1% of sodium nitrate was added was used.

Next, the grindstone 1 is rotated at a high speed (for example, 3300 rpm), and the voltage supply device E is activated to generate an alternating current (50V) with the above waveform.
, 0.6A, 50Hz), 2511x1
A grinding wheel feed rate of /min was obtained. This is 2.2 times the feed rate of grinding using a known electrolytic grindstone (10m71L/min).
It was 5 times hotter. The reason for this is that an electrically conductive state is generated between the conductive band 10 embedded in the curved end surface of the grinding wheel 1 and the non-conductive material M due to dielectric action, the melting of the material M progresses, and then the polishing band 11 is heated. This is because the mechanical grinding action of the particles progresses. Since both actions are repeated alternately within a short period of time, the melted portion is immediately mechanically peeled off and extremely efficient grinding can be performed.

Further, since the conductive abrasive band of the grindstone of the present invention is located across the end face of the disc grindstone, electrolytic discharge machining can be performed on the front and side surfaces in contact with the end face. Next, another comparative example will be shown.

Kui〉Comparative example 1 The grindstone 1 of the present invention was used in the state shown in FIG.

Sl3N4 was used as a non-conductive material M and was adhered onto a conductive processing table 5 with a conductive paste 6. Then, a machining voltage under the following conditions was applied between the rotating shaft 7 of the grindstone 1 and the machining table 5.

As a result, the following "grindstone wear dimensions" and "grindstone feed rate" were obtained.

Comparative Example 3 FIG. 3 shows a comparison of [depth of cut] and [processing speed] during cutting using the grindstone of the present invention and a general grindstone (metal+diamond).

The processing conditions at this time are as follows.

The present invention can obtain the following effects from the above.

It is possible to generate the effects of conventional electrolytic grinding and mechanical grinding synergistically, and to melt the material and peel off the melted part at high speed.

Even on non-conductive materials that cannot be energized by applying direct current, the mechanical grinding and electrolytic grinding described above can be applied alternately by applying alternating current.

Actually, AC of 5 to 20V (50Hz to 500Hz),
When applied to non-conductive ceramics, it was possible to obtain grinding speeds several times faster than conventional mechanical grinding.

Even in cases with strict requirements for finished dimensions and surface accuracy, there is no need to separately perform mechanical grinding as is the case with conventional electrolytic grindstones.

2〉 The finished surface is better than that obtained by mechanical grinding.
You can get a smooth surface.

<E> The grindstone used in the present invention does not need to be porous like conventional electrolytic grinding wheels, and can be of the same quality as commercially available mechanical grinding wheels, so it is strong and does not cause chipping. However, a diamond dresser or the like can facilitate thin-walled molding.

〇 Since AC power is supplied, substances that adhere to the grindstone are also subjected to electrolytic action, preventing clogging.〇

[Brief explanation of drawings]

FIG. 1: A diagram of the principle of the processing method of the present invention, FIG. 2: An explanatory diagram of the usage state of the grindstone of the present invention, and FIG. 3: A comparison diagram of processing speed with a conventional processing method. 1: disk body, 10: conductive band, 11: polishing band.

Claims (1)

[Claims] 1. Using a disc grinding wheel that alternately has a conductive abrasive band and a non-conductive abrasive band that cross the end face, the grinding wheel's conductive abrasive band and a non-conductive material fixed on a conductive processing table are used. A method for electrolytic grinding of non-conductive materials, characterized by applying an alternating voltage between the two and supplying an electrolytic solution.