| 摘要 |
<p>PURPOSE:To maintain the environmental condition in a shield affecting the working quality in a preferable condition during the working in the underwater shield. CONSTITUTION:An underwater working part 200 is provided with a shield 8 of approximately truncated conical shape where the larger diameter side in contact with a member 1 to be welded is opened and the other end is sealed, a welding torch 4 which is arranged in the shield 8 and connected to a TIG welding power source 2, and a gas hose 7 to communicate the shield 8 and the gas source 27 through the TIG welding power source 2 and a gas control device 18. A pressure detector 9, an oxygen content detector, and a nitrogen content detector which are arranged so as to penetrate the opening in the wall of the shield 8 and detect the pressure, the oxygen content and the nitrogen content respectively in the shield are included therein. A cylindrical projecting part is provided outside the part where the pressure detector 9 of the shield 8 is arranged, and the pressure detector 9 is arranged inside the projecting part. This constitution detects the environmental condition in the shield above the water level, and the environmental condition in the shield is maintained in the condition suitable for the working based on the detected environmental condition.</p> |
