| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of thermal stress by following up the shrinkage deformation of a No.1 and No.2 metal members, to prevent the generation of defects and to stabilize the joint strength of the both metal members by lowering a pressurizing force to a prescribed value which is lower than the pressurizing force in a jointing period during the cooling period of the both metal members along with the stoppage of heating and continuing pressurizing. SOLUTION: A cylinder head main body 2 is placed on the upper surface of a lower electrode tip of a connecting device and a valve seat 3 is placed on a connecting surface 2a. An upper electrode tip 24 is lowered to come into contact with the upper surface of the valve seat 3 and the pressurizing of valve seat 3 and the cylinder head main body 2 is started. Brazing filler metal is melted by heating with resistance heat generated by energizing a part between the valve seat 3 and the cylinder head main body 2 by switching on the welding source after about 1.5 sec, for instance, passes after the start of pressurization. About the same time as the energizing is stopped, the pressurizing force is lowed to a prescribed value which is lower than the pressurizing force in a jointing period by changing the application force of a pressure cylinder. Then, the pressurizing is stopped about 1.5 sec later, for instance, after the energizing is stopped. |
