Shoulder-angle-adjustable friction stir welding head suitable for fillet joint

A shoulder-angle-adjustable friction stir welding tool suitable for a fillet joint, comprising a stirring tool body, wherein a front end of the stirring tool body is mounted with a movable shoulder, a stirring pin channel is arranged on the movable shoulder, and the stirring pin channel allows a stirring pin of the stirring tool body to pass through;

• the movable shoulder comprises a first shoulder and a second shoulder, the first shoulder is rotationally connected with the second shoulder, and the stirring pin channel is located at a rotating joint between the first shoulder and the second shoulder;
• and the movable shoulder further comprises an angle adjusting plate, a first movable linkage and a second movable linkage, one end of the first movable linkage is rotationally connected with a rear end of the first shoulder while an other end of the first movable linkage is rotationally connected with one side of the angle adjusting plate, one end of the second movable linkage is rotationally connected with a rear end of the second shoulder while an other end of the second movable linkage is rotationally connected with an other side of the angle adjusting plate, and the angle adjusting plate moves up and down through a fixed plate on the stirring tool body to be limited and sleeved on the stirring tool body.