Patent ID: 8113735

Claim:
A joint structure comprising: a joint component formed of synthetic resin and having a fusible shaft; and a joining component having an insertion hole into which the fusible shaft is inserted, wherein the joint component and the joining component are joined together by applying ultrasonic vibrations to the fusible shaft inserted into the insertion hole to fuse the fusible shaft, each of the joint component and the joining component has at least two positioning members for positioning the joint component and the joining component, the positioning members of the joint component and the positioning members of the joining component are protruding portions and fitting holes, respectively, or fitting holes and protruding portions, respectively, and diameters of the insertion hole and the fusible shaft are set such that a gap C 1 is formed between the insertion hole and the fusible shaft that interrupts contact between the insertion hole and the fusible shaft, the gap C 1 being 5 to 15 times larger than a gap C 2 formed between each of the protruding portions and corresponding one of the fitting holes.