| 摘要 |
PURPOSE:To extend the life of the welding machine itself and to improve a welded state by providing a local vacuum evacuation device which can be changed in position to the part near a welding point. CONSTITUTION:The local vacuum evacuation device 13 contg. a suction port 11 and a suction pipe 12 is installed near the part above the welding point. The device 13 is so constituted that the position thereof can be changed as desired according to the irradiating angle of an electron beam. The device 13 having the capacity equal to or larger than the capacity of the vacuum evacuation device 7C in a differential pressure chamber sucks metallic vapor 3 through a suction pipe 12 and discharges the same into the atm. when a large amt. of the vapor 3 is generated at the welding point 2 by the electron beam during the welding operation. The backflow of the vapor 3 to an electron gun chamber 9 is thus eliminated and the consumption of a cathode or the like is decreased as well. The life of the welding machine body is extended and the welded state is improved. |
