Honda Giken Kogyo Kabushiki Kaisha

Junichi Nakade

Masahiro Sakanushi

Seiji Matsumoto

Fumihiko Maeda

Hiroaki Hishida

Takeshi Kurotobi

In a catalyzer arrangement in an exhaust system of a multi-cylinder internal combustion engine, each of exhaust pipes connected with exhaust ports of the engine has a first exhaust pipe section extending away from a main body of the engine, a second exhaust pipe section contiguous to the first exhaust pipe section having a first curved portion for turning the second exhaust pipe section toward the main body of the engine, and a third exhaust pipe section contiguous to the second exhaust pipe section having a second curved portion for turning the third exhaust pipe portion away from the main body of the engine. A catalyzer is connected to a downstream side of the third exhaust pipe section and disposed within a space surrounded by the first, second and third exhaust pipe sections. The exhaust pipes are divided into one group positioned near one end of a row of cylinder of the engine and another group positioned near another end of the row of cylinder. Exhaust pipes of the one group and exhaust pipes of the another group are collected into respective collective exhaust pipes at a portion extending over the second and third exhaust pipe sections or at the third exhaust pipe section.

Catalyzer arrangement in exhaust system of multi-cylinder internal combustion engine

A sealing structure in an exhaust system of an internal combustion engine includes a gasket which is clamped between a cylinder head and a flange fastened to the cylinder head and which has a sealing portion surrounding an exhaust port opening into a side of the cylinder head, and an exhaust pipe which is curved and coupled to the flange and which is in communication with the exhaust port. In this sealing structure, the sealing portion of the gasket is formed into an endless shape to surround said exhaust port, such that the distance between the sealing portion and a peripheral edge of the exhaust port, at least at a location substantially corresponding to a projected position of the exhaust pipe on the flange, is larger than the distance at other locations. Thus, it is possible to prevent or minimize the deterioration of the sealing portion of the gasket due to heat, while avoiding an increase in size of the section associated with the exhaust system.

Growing community of inventors

Wako, Japan

Junichi Nakade