| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently discharge a combustion gas in welding without arranging a forced discharge device to a welding chamber. SOLUTION: A discharge port 7 is arranged to the upper part of a welding chamber 1, a natural discharge tube 9 constituting of a metal tube, etc., arranged with a stop valve 8a and a check valve 8b of one way valve at least one place or more is connected to the discharge port 7. That is, the stop valve 8a is arranged to a discharge port 7 side of the natural discharge tube 9, a spherical check valve 8b is arranged near a end part of the natural discharge tube 9. A volume of the natural discharge tube 9 is set to a chamber volume of 0.2-1.0%, a spiral part 9a is formed in order to secure a volume by lengthening the distance from the discharge port 7 to the check valve 8b.</p> |
