Mazda Motor Corporation

Kensuke Ashikaga

Masayoshi Higashio

Yuichiro Tsumura

Daisuke Tanaka

Taiki Maiguma

Akira Tsuda

Yukio Haizaki

Kenichi Nakashima

Keitaro Ezumi

Hiroki Morimoto

Ken Yoshida

Mitsunori Wasada

Taketoshi Yamauchi

Jiro Kato

Takuji Okumura

Ryo Yamamoto

Haruna Yanagida

Kenji Takami

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

Air intake device for engine

A control device for a compression-ignition engine is provided, in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, an EGR (exhaust gas recirculation) controller configured to change an EGR ratio being a ratio of exhaust gas introduced into the cylinder, and a combustion controller configured to control the EGR controller to increase the EGR ratio when a noise index value specified based on the detected parameter of the detector is confirmed to exceed a given threshold during the partial compression-ignition combustion.

Control device for compression-ignition engine

A control device for an engine in which partial compression-ignition combustion including SI combustion performed by forcibly combusting a portion of mixture gas inside a cylinder followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine, is provided. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, a memory configured to store a characteristic defining a relationship between a start timing of the CI combustion and a combustion noise index, and a processor configured to specify a given combustion noise index value based on the detection value of the detector, and control the start timing of the CI combustion.

Control device for engine

An engine system includes: a hydraulic valve stop mechanism configured to switch states of an intake valve and exhaust valve of a same stopped cylinder; a hydraulic pressure changing device configured to change hydraulic pressure supplied to the valve stop mechanism; and a valve control portion configured to control the hydraulic pressure changing device. When a return from a reduced-cylinder operation to an all-cylinder operation is requested, and an engine revolution is less than a reference revolution, the hydraulic pressure is changed such that opening of one of the valves of the stopped cylinder able to restart at an earlier stage is first restarted. When the return is requested, and the engine revolution is not less than the reference revolution, the hydraulic pressure is changed such that opening of the exhaust valve of the stopped cylinder is restarted before opening of the intake valve.

Engine system with valve stop

Provided are a valve stop mechanism capable of switching intake valves and exhaust valves of deactivated cylinders between an openable/closable state and a closed state, and an engine speed control unit which controls the engine speed. The engine speed control unit controls the engine speed in such a manner that the amount of change in the engine speed with respect to time is reduced, as compared with a case in which a specific condition is not satisfied, when the specific condition that switching by the valve stop mechanism is not completed, and that connection between an engine and a power transmission unit is released is satisfied after issuance of a switching request from one of a reduced-cylinder operation and an all-cylinder operation to the other thereof.

Engine control device

Growing community of inventors

Hiroshima, Japan

Kensuke Ashikaga