Mazda Motor Corporation

Saori Mizuno

Mitsuhiro Muto

Takuma Fujii

Takayuki Hikita

Masahisa Yamakawa

Keiji Araki

Junichi Taga

Kouhei Iwai

Shigeru Nakagawa

An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, an intake valve operating mechanism, and an exhaust valve operating mechanism, an accelerator opening sensor, and a controller. The engine is configured to execute flame propagation combustion and compressed self-ignition combustion. The controller performs a combustion control so that a target torque set based on an accelerator opening is realized in a specific cycle in the future from a present time by a given delay time. The controller sets beforehand the combustion mode based on a target load, estimates an in-cylinder property when the intake valve is closed in the present cycle, sets a target in-cylinder property so that the set combustion mode is realized in the specific cycle, and sets a target operating amount of each of the intake and exhaust valve operating mechanisms based on the set target in-cylinder property.

Engine system and engine controlling method

An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, and a property adjusting device, an accelerator opening sensor, and a controller. The controller performs a combustion control for controlling the injector, the spark plug, and the property adjusting device so that a target torque set based on a present accelerator opening detected by the accelerator opening sensor is outputted in a specific cycle in the future from a present time by a given delay time. In the combustion control, the controller sets a target load of the engine in the specific cycle based on the present accelerator opening, and sets a combustion transition from the present cycle to the specific cycle by selecting beforehand combustion from the present cycle to the specific cycle, from flame propagation combustion and compressed self-ignition combustion, based on the set target load.

A method of controlling an engine is provided, which includes setting, by a controller, a target torque of the engine in a specific cycle in the future by a given delay time from the present time based on a present accelerator opening. The method includes selecting beforehand, by the controller, combustion in the specific cycle according to the target torque, from flame propagation combustion and compressed self-ignition combustion. The method includes outputting, by the controller, a control signal to a property adjusting device before the specific cycle so that a property inside the cylinder in the specific cycle becomes a property corresponding to the selected combustion. The method includes estimating, by the controller, the property at a timing when an intake valve is closed in the specific cycle. The method includes outputting, by the controller, a control signal corresponding to the estimated property to a spark plug or an injector.

Engine controlling method and engine system

A spark-ignition direct injection engine is provided. The engine includes an engine body, a fuel injection valve, a fuel pressure setting mechanism, an ignition plug, and a controller. The controller switches between a compression-ignition mode where the engine body is operated to perform compression-ignition combustion and a spark-ignition mode where the engine body is operated to perform spark-ignition combustion. Immediately after switching from the spark-ignition mode to the compression-ignition mode, the controller operates the engine body in a compression-ignition initial mode where the fuel pressure is set to be 30 MPa or above and the fuel injection valve is controlled to perform the fuel injection in a period from a late stage of the compression stroke to an early stage of the expansion stroke so that the gas mixture self-ignites to combust.

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Aki-gun, Japan

Saori Mizuno