Mazda Motor Corporation

Kento Onishi

Yasushi Nakahara

Yuya Honda

Michiharu Kawano

Atsushi Inoue

Kota Matsumoto

Masaki Fukuma

Satoshi Imamura

Yoshiharu Ueki

Tsuyoshi Yamamoto

Yohei Suzuki

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side. An ignition portion of the ignition plug is disposed on the intake port side. The ignition plug is ignited at a timing after the piston passes a compression top dead center. The injector is disposed on the center portion, and is configured to inject fuel toward the exhaust port side. A cavity is provided on the crown surface. A reverse squish flow generation portion is provided in the combustion chamber.

Combustion chamber structure for engines

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface formed on a cylinder head, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side, with respect to a position, as a reference, where an ignition portion of the ignition plug is disposed in a plan view from one side in a cylinder axis direction, the injector is configured to inject fuel toward the exhaust port side, and a reverse squish flow generation portion, which draws an air-fuel mixture toward the intake port side, is provided in the combustion chamber.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a cylinder wall surface, a combustion chamber ceiling surface, and an ignition plug which includes an ignition portion. The crown surface of the piston includes: a cavity recessed in the cylinder axis direction; a parallel surface portion which is in parallel to a corresponding region on the combustion chamber ceiling surface at a position above the cylinder axis direction with a gap, when the piston is at a compression top dead center; and an inclined surface portion formed to continue to the parallel surface portion in such a way as to be directed to the ignition plug, when the piston is at a compression top dead center. The parallel surface portion and the corresponding region, in combination, constitute a squish flow generation portion generating a squish flow when the piston is lifted.

A structure of a combustion chamber for an engine includes: a crown surface of a piston; a combustion chamber ceiling surface formed on a cylinder head; and an ignition plug mounted on the combustion chamber ceiling surface, and including an ignition portion disposed in such a way as to face the combustion chamber. The crown surface of the piston includes a cavity which is recessed in a cylinder axis direction in a region including a position below the ignition portion of the ignition plug in a plan view from the cylinder axis direction. A rim portion of the cavity includes a guide portion, raised in the cylinder axis direction with respect to an inner region of the rim portion, interposing the ignition portion when the piston is at a compression top dead center, and configured to guide an air-fuel mixture within the combustion chamber to the ignition portion.

In an engine (), an ignition plug () is arranged between a first intake port () and a second intake port (). In a case where a downstream end portion () of the second intake port () is divided into a first intake port () side and an opposite first intake port () side, an inner wall surface () of an opposite first intake port () side portion extends in a direction toward the first intake port () as extending from an upstream side to a downstream side of the second intake port ().

Intake port structure for internal combustion engine

In an engine (), when an intake valve () opens, a downstream end portion () of a first intake port () extends to direct to between a shade back () positioned on a cylinder axis (C) side with respect to a valve stem () and a ceiling surface () facing the shade back (). As viewed in a section perpendicular to a direction perpendicular to an intake air flow direction, a second intake port side inner wall surface () at the downstream end portion () of the first intake port () curves apart from a second intake port () in a direction from an exhaust side to an intake side as compared to the shape of an opposite second intake port side inner wall surface () mirror-reversed to a second intake port () side.

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Hiroshima, Japan

Kento Onishi