Abstract: A crash prevention device for a machine tool for preventing the collision of a moving part of the machine tool with other machine tool parts or with a workpiece in a working area of the machine tool includes an isolation mechanism that electrically isolates the moving part from the other machine tool parts or the workpiece. The device includes a detection system with a high voltage generator having a first positive connector electrically connected to the moving part and a negative connector electrically connected to the workpiece or to the other machine tool parts. The high voltage generator generates DC, AC, or pulsating voltage. The detection system includes a discharge detection device that detects an electrical discharge between the moving part and the workpiece or between the moving part and the other machine tool parts, then sends a signal to stop or adapt further relative movement of the moving part.

Abstract: A crash prevention device for a machine tool for preventing the collision of a moving part of the machine tool with other machine tool parts or with a workpiece in a working area of the machine tool includes an isolation mechanism that electrically isolates the moving part from the other machine tool parts or the workpiece. The device includes a detection system with a high voltage generator having a first positive connector electrically connected to the moving part and a negative connector electrically connected to the workpiece or to the other machine tool parts. The high voltage generator generates DC, AC, or pulsating voltage. The detection system includes a discharge detection device that detects an electrical discharge between the moving part and the workpiece or between the moving part and the other machine tool parts, then sends a signal to stop or adapt further relative movement of the moving part.

Abstract: In the process of machining by electroerosion, there is adjusted during a first transitory phase the machining current increase of the discharges after triggering a discharge between the electrode and the piece, such that a parameter connected to this increase will be substantially equal to a reference value corresponding to a minimum wear value of the electrode. Then, the machining current is maintained during a second phase at a reference value. The adjustment is carried out by acting on the adjustable internal voltage of a low impedance adjustable voltage source connected between the electrode and the piece. The adjustment can be carried out by a servo control loop with a regulator of the internal voltage, a device for generating discharges, parts adapted to determine the slope of increase of the current of a discharge, a member determining the mean slope of N discharges and a member adapted to compute the difference between the mean slope and a pre-established reference slope.