PURPOSE: To easily form a weld zone and to form a joint part having excellent weldability and appearance by providing a tongue part to the end of a square pipe, and bending the other side wall inward toward said part thereby forming a joint side wall.
CONSTITUTION: The end of the square pipe 1 is pressed by using a punch 2 to form the tongue part 1e. The pipe 1 is then rotated 90° to bring the side wall 1c upward and thereafter the pipe is pressed by a punch 3. The side wall 1c is bent inward around the tongue part 1e by such pressing, by which the joint side wall 1f is formed. The joint side wall 1f and cutting face 1h are pressed to the side walls 5a, 5b of the other square pipe 5 and the contact edges are welded 6. The weld zone is, therefore, easily formed by pressing and the joint part having the excellent weldability and appearance is formed.
| JP5618856 | Motorcycle body frame |
| JPS59306 | [Title of the device] The frame of a motorcycle |
| JPS5739051 | MANUFACTURE OF PIPE FRAME FOR VEHICLE |
ONO MASAHIRO
MATSUO KATSURA
YAMAHA SHATAI KOGYO KK