Patent ID: 11965445
Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
Field: Environmental technology (Chemistry)
Classification: CPC F | IPC F

Claim 2:
3. A fastening structure that fastens an exhaust manifold to a cylinder head of an engine, the fastening structure comprising:
an exhaust port of the cylinder head, the cylinder head including an opening of the exhaust port that is open to outside of the cylinder head;
a flange arranged on an end of a branch pipe of the exhaust manifold, wherein the flange is fastened to a coupling surface that surrounds the opening of the exhaust port to connect an opening of the exhaust manifold to the opening of the exhaust port, and the flange includes a first end portion and a second end portion that contact the coupling surface and are located at opposite sides of the branch pipe;
a fixing member fixing the first end portion of the flange to the cylinder head;
a bolt extending through the second end portion of the flange, the bolt being inserted into and fixed to a bolt hole of the cylinder head; and
a nut fastened to the bolt to fix the second end portion of the flange to the cylinder head,
wherein the second end portion of the flange includes a contact surface that contacts the coupling surface of the cylinder head, and an inclined surface that is inclined with respect to the contact surface such that the inclined surface becomes closer to the contact surface as the inclined surface becomes farther away from the branch pipe, and
wherein the nut, fastened to the bolt that extends through the inclined surface, contacts the inclined surface; and

an unobstructed clearance, provided between the bolt and the cylinder head inside the bolt hole, which extends in a range extending from the coupling surface of the cylinder head to a specified length.