| 摘要 |
PROBLEM TO BE SOLVED: To facilitate gas shielding work for a metal tube by using a device having balloons made of an elastic body at two places on a support body. SOLUTION: At the time of joining Ti alloy tubes by heating/pressurizing, the tubes are butted and inserted into a device and a tip balloon is expanded. When the tip balloon is expanded to stick to a tube wall, after tube passage is shut out, shield gas is released to fill the space between two balloons. Air in the space is purged to be replaced with shield gas and then a base part balloon is expanded, gas shielding of tube inner face is completed. When this assembly is heated with a high frequency induction coil while joining faces are pressurized with a pressurizing means, an insert material is fused and joining of the tubes completed. The expanded gas is discharged in both balloons after waiting for cooling and the tube is taken out from the device. By this method, the Ti alloy tubes of any length can be connected. |
