| 摘要 |
PURPOSE:To reduce the inert gas amount used for a resistance welding by movably supporting a chamber to one part of the welding electrodes and providing the feeding pipe selectively feeding an inert gas to the chamber on the welding electrode of the other part. CONSTITUTION:A cap 5 is fitted by a magnet 3 to the electrode chip 2b of the upper part electrode 2 and a base 9 is fitted to the lower part electrode 6. An inert gas is jetted from exhaust nozzles 8a, 8b via a feeding pipe 8 with a valve 10 being opened simultaneously with the descent of the upper part electrode 2. When a chamber 1 reaches near to the lower part electrode 6, the descent of the upper part electrode 2 is once stopped and the inside of the chamber 1 is replaced by the inert gas. The upper electrode 2 is then descended again, the cap 5 and base 9 are pressed with the prescribed force, the electrodes 2, 6 are electrified and the projection welding is performed. With completion of the welding, the valve 10 is closed, the cap 5 is pushed to the lower part by descending a rod 4, the upper electrode 2 is ascended and the welded cap 5 and base 9 are taken off. In this way, the use amount of the inert gas can remarkably be reduced. |
