ELECTROEROSION MACHINE FEATURING PHOTOELECTRIC SENSING MEANS FOR MEASURING WIRE ELECTRODE DEFLECTION

摘要

PCT No. PCT/CH88/00185 Sec. 371 Date May 26, 1989 Sec. 102(e) Date May 26, 1989 PCT Filed Oct. 11, 1988 PCT Pub. No. WO89/03270 PCT Pub. Date Apr. 20, 1989.The invention presents a spark erosion machine, having a travelling wire electrode and an optical measuring means to measure the deflection of the travelling wire electrode. The measuring means includes a light source (10) producing a homogeneous parallel bundle of rays. A sensor assembly (1,11) measuring the light beam which comes from the light source and is shaded by the travelling wire electrode (9) is designed such as to absorb a light quantity which is dependent in one-to-one correspondence on the relative position of the travelling wire electrode (9). An evaluation circuit connected downstream of the sensor assembly provides an electrical signal indicating the deflection of the travelling wire electrode from its straight position. By means of this electrical signal, the relative positions of the guide heads of the travelling wire electrode and that of the workpiece can be corrected in such a way that machining errors caused by the deflection of the travelling wire electrode can be avoided.