DETECTING DEVICE OF DISTANCE OF LASER PROCESSING MACHINE NOZZLE

• Main Authors: NONAKA SATOSHI, YOSHIDA SHINJI
• Format: Patent
• Language: English
• Published: 27.02.1990
• Subjects: CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; MACHINE TOOLS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PHYSICS; SOLDERING OR UNSOLDERING; TESTING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

PURPOSE:To enable accurate detection of a distance by providing a voltage impressing means which impresses a voltage of the same phase and amplitude with those of a voltage of an insulated conductor on a sheath of a cable. CONSTITUTION:An electrostatic capacity C1 between an electrode 2 and a workpiece 6 is detected by an electrostatic capacity detector 4 through an insulated conductor 3a of a cable 3. A voltage of the same phase and amplitude with those of a voltage of the insulated conductor 3a is applied to a sheath 3b by an amplifier 5 and thereby a potential difference and a phase difference between the insulated conductor 3a and the sheath 3b are eliminated. Therefore no current flows through an electrostatic capacity C2 between the insulated conductor 3a and the sheath 3b. Although there is an electrostatic capacity C3 between the sheath 3b and the ground, a current flowing therethrough is supplied from the amplifier 5 and, therefore, no current flows from the core 3a through the capacity C3. Moreover, no current flows between first and second electrodes 2 and 2a. Accordingly, electrostatic capacities between the capacities C2 and C3 and between the electrodes 2 and 2a are not detected in the detector 4. In other words, only the capacity C1 is detected in the detector 4 and, consequently, a distance can be measured accurately.