BOTH- SIDE FRICTION STIR BONDING METHOD AND DEVICE FOR METAL PLATE IN COLD ROLLING FACILITY ; CORRESPONDING COLD ROLLING FACILITY

摘要

When metal plates each having a thickness smaller than a diameter of each of shoulders of rotary tools are joined by both-side friction stir welding, rupture and defective joining of the metal plates are suppressed, joining strength is enhanced, and reliability of the joining strength is improved, while the tool life is prolonged and the rotary tool economy is improved. Inlet and outlet side gripping devices 7, 8 grip front and back surfaces of metal plates 1, 2, respectively, and rotary tools 5, 6 disposed in opposed relationship in the front surface side and the back surface side of the welding portion J are moved in a direction in which the upper and lower rotary tools approach to each other and impart a predetermined clearance ´ between distal ends of probes 13a, 13b of the upper and lower rotary tools 5, 6 while pressing the shoulders 5b, 6b thereof against the front and back surface sides of the welding portion J. Under this state, the upper and lower rotary tools 5, 6 are moved along the butting portion J while rotating the upper and lower rotary tools thereby to perform the friction stir welding. At this time, the axes 14 of the upper and lower rotary tools 5, 6 are inclined in a direction in which the respective probes 13a, 13b move ahead of the other portions of the rotary tools with respect to a traveling direction of the rotary tools 5, 6.