TWO-MEMBER CAULKING STRUCTURE, EXHAUST BYPASS VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINE USING THE SAME, AND METHOD FOR FORMING PLATE-LIKE MEMBER HAVING THROUGH-HOLE

摘要

PPROBLEM TO BE SOLVED: To provide an excellent caulking structure in which the caulking force is not degraded even when it is used under the environment of high temperature such as an exhaust bypass valve and the heat cycle is repeated. PSOLUTION: The coupling force is obtained by the pinching force generated between first and third joining surfaces on both sides of a plate-like member and a tightening force generated by the swelling deformation of a shaft-like member to the outside diameter side in second and fourth joining surfaces formed around the shaft-like member by pressing both sides of the shaft-like member inserted in a through-hole in the plate-like member to give the caulking deformation to one end of the shaft-like member. A gently inclined surface (the chamfered shape) as the fourth joining surface is constituted in the corner part on the shaft-like member caulking side of the through-hole. As a result, the tightening force generated in the second and fourth joining surfaces is added to the pinching force generated between the first and third joining surfaces, and the high and stable joining force can be obtained. PCOPYRIGHT: (C)2003,JPO