| 摘要 |
PURPOSE:To stabilize the weld quality by providing a welding pressure stopping means to stop an increase of the welding pressure with respect to materials to be welded of electrode tips corresponding to a signal from a welding pressure detecting means and controlling the welding pressure as set at all times. CONSTITUTION:The tip of the upper electrode tip 124 comes into touch with the materials 128 and 130 to be welded and furthermore, when an air cylinder 100 is driven, the welding pressure is increased to attain a prescribed value. A microswitch 134 is made on at this time and energization is started. At the same time, a switching valve 12 is closed and the movement of oil from a hydraulic cylinder 10 to a hydro-converter 14 is interrupted. In this way, the hydraulic cylinder 10 checks a fall of a welding slide rod. As a result, the welding pressure more than an expected value is not applied to a pressure maintaining plate 112 and a spring pressing member 114 and the welding pressure as set is always impressed on the materials 128 and 130 to be welded and the stable welding can be performed. |
