Yutaka Giken Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Kazuhiro Furuhashi

Hiroshi Hashimoto

Takashi Komatsuda

Seiji Kato

Kazuo Ishii

Toru Hisanaga

Koichi Fujimori

Masafumi Imasaka

Tatsumi Yamada

Ichiro Moritake

Koichi Tanino

Hiroshi Shinmura

Shuichi Nishizaki

Hirokazu Mori

Yasuyuki Sakurai

Hirokazu Shirai

A double exhaust pipe for an engine includes an inner pipe shell, and an outer pipe shell in which the inner pipe shell is accommodated. The inner pipe shell is secured at one end thereof to the outer pipe shell and slidably fitted at the other end thereof to an inner peripheral surface of the outer pipe shell. A heat-insulating space is provided between the inner and outer pipe shells to extend from the one end to the other end of the inner pipe shell. In this double exhaust pipe, the inner pipe shell has a bulged portion formed at the other end thereof. The bulged portion has a spherical outer surface slidably and oscillatably fitted to an inner peripheral surface of the outer pipe shell. Thus, even if the free end of the inner pipe shell is inclined upon thermal elongation of the inner pipe shell, the bulged portion at the free end can always be smoothly slipped on the inner peripheral surface of the outer pipe shell.

Double exhaust pipe for engine

An exhaust manifold M is comprised of a plurality of inner exhaust pipe shells secured to an upper flange, and a plurality of outer exhaust pipe shells secured to the upper flange to individually cover the inner exhaust pipe shells, wherein a downstream end of each of the corresponding inner exhaust pipe shells slidably contacts an annular bead bulging from an outer peripheral surface of the downstream end of the outer exhaust pipe shells. An inner collecting pipe shell communicates with the plurality of inner exhaust pipe shells and is secured at its upstream end to the plurality of outer exhaust pipe shells, and an outer collecting pipe shell which is secured at its upstream end to the plurality of outer exhaust pipe shells covers the inner collecting pipe shell. A downstream end of the inner collecting pipe shell slidably contacts an annular mesh member interposed therebetween. Sliding portions for absorbing a difference in the axial thermal elongation between inner and outer double walls are provided separately at the downstream end of an exhaust single pipe and the downstream end of an exhaust collecting pipe. Thus, the sliding stroke in each of the sliding portions can be set to a small value, and the absorption of the thermal elongation can be carried out smoothly.

Heat-insulation type exhaust manifold

An exhaust manifold for an engine includes a manifold body 7 having a plurality of branch pipes and a common collecting chamber integrally connected to the branch pipes and communicating with an exhaust emission control device is divided into an upper half and a lower half at a boundary face extending in a direction of arrangement of the branch pipes. The upper and lower halves are made of steel plates and welded to each other. In the exhaust manifold, a welding mating coupler is formed by outer edges of the upper and lower halves, and a welding stepped superposing coupler is formed by inner edges of the upper and lower halves. Thus, during welding, it is possible to limit the misalignment of the upper and lower halves in a direction along the boundary face and the misalignment of the upper and lower halves in a direction perpendicular to the boundary face by cooperation of the mating coupler and the stepped superposing coupler. In addition, because the stepped superposing coupler is used for coupling of inner edges of the upper and lower halves to each other, it is possible to ensure sufficient clearances between the adjacent branch pipes, and to easily conduct the operation of mounting of the exhaust manifold to the engine by utilizing the clearances.

Exhaust manifold for engine

Growing community of inventors

Hamamatsu, Japan

Kazuhiro Furuhashi