Upset welding apparatus and upset welding method

摘要

To provide an upset welding technique having high shaping function of a weld bulge part and excellent workability.SOLUTION: Upset welding is executed by use of: a first clamp C1 and a second clamp C2 which grip first and second bar steels B1, B2 respectively in a state that axes X of the first bar steel B1 and the second bar steel B2 are so made as to be coincident with each other; an electric conduction part 7 which electrically conducts the first and second bar steels B1, B2 via the first clamp C1 and the second clamp C2; a pressurizing part 5 which is provided on at least one of the first clamp C1 and the second clamp C2, and mutually presses a first end surface B1a of the first bar steel B1 and a second end surface B2a of the second bar steel B2 along the axes X; a control part 6 which controls operations of the electric conduction part 7 and the pressurizing part 5; and a wall member 4 which is opposed to a part of outer peripheral surfaces of the first and second bar steels B1, B2 with respect to a contact part between the first end surface B1a and the second end surface B2a, and has a contact surface 4a which comes into contact with a weld zone of the first and second bar steels B1, B2 when electrically conducting and pressurizing the first and second bar steels B1, B2.SELECTED DRAWING: Figure 1