Apparatus for detecting defects at gas exhaust line in casting machine and method therefor

摘要

A gas venting system is connected to a downstream side of a gas vent valve through a gas exhaust line. An electromagnetic valve and a suction unit are connected to the gas exhaust line. A pressure switch is directly connected to the gas exhaust line to detect the pressure variation within the line. By the suction through the suction unit and the opening of the electromagnetic valve, the gas exhaust line is decompressed. If the line has a perforation, the pressure does not reach a predetermined pressure. If clogging occurs, the pressure reaches a predetermined pressure while the metal molds are open and the gas vent valve is open. Thus, accurate detection to the defects can be achieved regardless of the state of the metal molds and the internal volume of a vacuum tank.