Patent ID: 11858060
Assignee: KAWASAKI JUKOGYO KABUSHIKI KAISHA
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A friction stir spot welder adapted to weld workpieces through softening induced by friction heat, the workpieces including first and second workpieces stacked in the presence of a sealant applied to a region of contact between the first and second workpieces, the friction stir spot welder comprising:
a pin in the form of a solid circular cylinder;
a shoulder in the form of a hollow circular cylinder, the shoulder having an interior in which the pin is inserted;
a rotary actuator that rotates the pin and the shoulder about an axis coinciding with a central axis of the pin;
a clamp in the form of a hollow circular cylinder, the clamp having an interior in which the pin and the shoulder are inserted;
an advancement/withdrawal actuator that advances and withdraws the pin, the shoulder, and the clamp along the axis; and
a controller, the controller being configured to:
(B) drive the rotary actuator and the advancement/withdrawal actuator to cause the pin to press the workpieces for a first predetermined time while rotating;
(C) after performing the pressing (B), drive the rotary actuator and the advancement/withdrawal actuator to cause the pin and the shoulder to press the workpieces for a second predetermined time while rotating; and
(D) after performing the pressing (C), drive the rotary actuator and the advancement/withdrawal actuator to cause the pin and/or the shoulder to plunge into a weld region of the workpieces while rotating and stir the weld region to weld the workpieces together.