| 摘要 |
PURPOSE:To prevent adverse welding operations such as a back fire, abrupt ignition and a lifting phenomenon, by a method wherein the electromagnetic valve of oxygen side is first closed, and the electromagnetic valve is opened with the delay of few seconds after a take-up timing, whereas the electromagnetic valve of acetylene side is first opened and the electromagnetic valve of oxygen side is opened with the delay of few seconds. CONSTITUTION:When a welding operation being temporarily suspended, a micro- switch 11 is turned ON upon a cutting tip 13 being placed on a cutting tip mounting table 10, and thereby first closing the electromagnetic valve 9 of oxygen side and then the electromagnetic valve 8 of acetylene side. In re-starting the welding operation, the cutting tip is raised upwardly with the aid of a manual operation. At this moment, if a touch sensor is contacted by a finger, an automatic ignition device is actuated to output to a lighter 16 a signal instructive of ignition start-up. At the same time, if the cutting tip 13 is taken up, the micro-switch 11 is turned OFF and the electromagnetic valve 8 of acetylene side is opened in a few seconds later. Then, the electromagnetic valve 9 of oxygen side is caused to open with a delay. In this manner, it is made possible to suppress the occurrance of back fire, abrupt ignition and lifting phenomenon. |
