| 摘要 |
PURPOSE:To determine starting position and timing of forge pressing by detecting the real value of amount of swaging of a crosshead by measuring the amount of displacement of a pressure base caused by swaging of a crosshead to a bearing bar by energizing fixing a zero point at the start of the forge pressing at the position of the pressure base in pressurized state before energizing. CONSTITUTION:In channel cover grating welding that welds a crosshead to a bearing bar by resistance welding, a detector 10 is connected mechanically to a pressure base 7 with a cylinder 16 in such a manner that the detector 10 can start to move from a zero point which is fixed at the position of the pressure base 7 before starting the welding and in a pressurized state. The mechanical connection is maintained during swaging, and the starting point of forging is determined by detecting the amount of swaging by a detector 10 that is removed only by the amount of swaging. |
