Apparatus for Removing Material, Use of Gas Inclusions in an Abrasive Liquid and Process for Grinding and/or Polishing Surfaces

Abstract

The invention relates to an apparatus for removing material from a surface of a workpiece during grinding and/or polishing of the surface by means of abrasive particles which are delivered by a liquid. The apparatus comprises a device for setting the gas content in the liquid, in particular for adding gas, in particular air, to the liquid.

Description

[0001]This application is a division of application Ser. No. 11 / 186,802, filed Jul. 22, 2005.BACKGROUND OF THE INVENTION[0002]The invention relates to the use of gas inclusions in an abrasive liquid and to a process for removing material during grinding and / or polishing of surfaces of workpieces.[0003]It is known to grind or polish surfaces using abrasive particles which are delivered in a liquid. This has the advantage that there is no need for a grinding tool.[0004]The material-removal rate from the surface depends firstly on the size of the abrasive particles in the jet. Secondly, it depends on the energy and therefore the velocity of the particles at the instant that they strike the surface. The material-removal rate is to be understood as meaning the amount of material removed per unit time.[0005]U.S. Pat. No. 5,700,181 has disclosed, for example, a process for grinding and a nozzle for accelerating the abrasive liquid. The abrasive liquid is delivered into the nozzle at a high...

AI Technical Summary

Benefits of technology

[0043]It is advantageous for the delivery pressure of the abrasive liquid to be kept constant at less than 100 bar, advantageously less than 50 bar, particularly advantageously less than 20 bar, for both grinding and polishing. This simplifies the process, since there is no need to alter the delivery pressure of the liquid if the material-removal rate is to be varied.

Problems solved by technology

Secondly, it depends on the energy and therefore the velocity of the particles at the instant that they strike the surface.

These known processes have the drawback that processes which remove large amounts of material, in particular grinding, have to use coarser abrasive particles than precision-grinding and polishing processes.

Also, the transition from grinding to polishing cannot take place continuously.

If coarser particles are still present during the precision grinding or polishing, these particles lead to deep scratches, which can render the entire workpiece unusable.

This increases the procurement or production costs.

This in turn increases the working time and the production costs.

Moreover, contamination can result or the workpiece may be damaged.

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