Mazda Motor Corporation

Shunki Okazaki

Mikihito Fujii

Mitsuo Nakamura

Nobuhiro Soumiyou

Hiroshi Kinoshita

Shinji Fujihira

Takeshi Yokoo

Yuji Akagi

Takamasa Matsumoto

Yoshito Wakabayashi

Masanao Yamada

An exhaust device includes a plurality of independent exhaust passages connected to an exhaust port of one cylinder or a plurality of cylinders that are non-sequential in exhaust order, and a mixing pipe into which exhaust that has passed through the respective independent exhaust passages flows. The downstream ends of the respective independent exhaust passages are connected in a bundled form to the upstream end of the mixing pipe. A cavity expansion chamber is disposed in an exhaust passage downstream from the mixing pipe. The cavity expansion chamber is disposed in a position (at a distance L2) such that, in the intermediate speed range, a negative pressure wave generated due to an exhaust pressure wave generated by opening an exhaust valve being reflected by the cavity expansion chamber reaches the exhaust port during an overlap period of the exhaust valve and an intake valve of the cylinder.

Exhaust device for multicylinder engine

An exhaust apparatus for a multi-cylinder engine which is capable of suppressing deterioration in ejector effect with a simple configuration comprises: a plurality of independent exhaust ducts each having an upstream end connected to an exhaust port of one cylinder or exhaust ports of two or more cylinders which are non-successive in terms of exhaust order; and a merged portion configured to allow exhaust gas passing through each of the independent exhaust ducts to flow thereinto and formed to be gradually reduced in diameter toward a downstream side in an exhaust gas flow direction. The independent exhaust ducts are connected to an upstream end of the merged portion in such a manner that downstream ends thereof are bundled together. An O2 sensor is provided in the merged portion or a portion of an exhaust duct line downstream of the merged portion, to partially block an exhaust gas flow passage.

Exhaust apparatus for multi-cylinder engine

An intake system of an engine comprises an intake module, in which a throttle body joint portion and an upstream portion of an intake manifold are formed in a single structure, and a downstream portion of the intake manifold extending from an engine body. A downstream end of the intake module is joined to the downstream portion of the intake manifold and an end portion of the intake module opposite to its portion joined to the downstream portion of the intake manifold is connected to an uppermost part of an oil filler pipe which is connected to the engine body. In this construction, the intake module is supported by the engine body via the oil filler pipe.

Intake system of an engine

An intake system is incorporated in a multi-cylinder internal combustion engine having a plurality of cylinders each being provided with at least three intake ports, at least one of the three intake port being timed to close after the remaining intake ports which are timed to close closely to each other. The intake system includes a main intake pipe introducing intake air into the intake system. The main intake pipe is connected to the remaining intake ports of the cylinder by way of a common intake pipe and to the at least one intake port of the cylinder by way of an intake pipe provided independently from the common intake pipe.

Intake system for automotive engine

Growing community of inventors

Hiroshima, Japan

Shunki Okazaki