Method of correcting the determination of workpiece and tool positions in machine tools

摘要

The invention concerns a method of correcting the determination of positions of workpieces and tools which can be moved relative to one another in machine tools, in particular CNC machining centres, by means of measuring systems internal to the machines. Machining inaccuracies caused by changes in the positions of the workpiece and/or tool owing to heat in the working region of the tool can be avoided if the workpiece and tool are moved with associated measuring points or measuring edges through a stationary optical test barrier, simultaneously or at short intervals one after the other. If the test barrier is interrupted, the respective positions of the workpiece and tool are determined by means of the measuring system internal to the machine. The positions determined are compared with stored positions determined during a previous measurement, and the difference between the determined position and the stored position is used to correct the machine control. The invention further concerns a machine for carrying out the method.