Patent attributes
There is provided a friction stir spot joining device to eliminate the generation of tipping torque caused by a pressing force by allowing the axis of a ball screw for generating the pressing force and the center of a shaft of a stirring motor to be coincident with each other, thereby allowing the device to be downsized and the device to effect joining operation with ease. The friction stir spot joining device comprises a ball nut fixed to the rear end side the stirring motor, a hole is defined in an output shaft of the stirring motor in which the ball screw is housed from a rear portion of the hole so as to be positioned in the hole, wherein a rotating force of the pressing motor is transmitted to the ball screw and the stirring motor is moved forward and backward by the ball nut threaded with the ball screw.
