Hitachi, Ltd.

Yuusuke Kihara

Toshiharu Nogi

Takuya Shiraishi

Shiro Yamaoka

Minoru Oosuga

Shinji Nakagawa

A control apparatus operates a compression ignition internal combustion engine by switching between spark ignition combustion using an ignition device and compression ignition combustion which self-ignites a mixture by piston compression. Variable valve mechanisms vary at least one of the valve timings and valve lifts of an intake valve and an exhaust valve. Intake air is regulated to vary the amount of air intake into a combustion chamber on the upstream side of a combustion chamber inlet of the compression ignition internal combustion engine. The variable valve mechanisms and the intake air regulation are controlled during the compression ignition combustion so as to perform the compression ignition combustion.

Compression ignition internal combustion engine

A compression ignition internal combustion engine includes a combustion chamber, an intake valve, intake port, and an exhaust valve. The temperature and pressure in the combustion chamber are increased to self-ignite an air-fuel mixture with the compressive operation of a piston after closing of the intake valve. A fuel injection valveinjects pressurized air, serving as an ignition trigger factor, directly into the combustion chamber so that the air-fuel mixture under the expansion stroke of the piston is brought into an ignitable state. An ECUcontrols the injection timing of the pressurized air depending on the ignition timing. The self-ignition timing can be controlled to a proper timing in a wide engine operating range with respect to a load and a revolution speed without changing the shape of the combustion chamber to a large extent.

A compression ignition internal combustion engine in which the temperature and pressure in the combustion chamber are increased to self-ignite an air-fuel mixture with the compressive operation of a piston after closing of the intake valve. An ECU [] controls injection timing of the pressurized air depending on the ignition timing. Self-ignition timing can be controlled to a proper timing in a wide engine operating range with respect to a load and a revolution speed without substantially changing the shape of the combustion chamber.

It is an object of the present invention to provide a compression ignition internal combustion engine capable of making compatible an increase in compression self-ignition operating area with an optimum output torque control in the operating area and also smoothly switching between a self-ignition combustion and a spark ignition combustion. The compression ignition internal combustion engine operates by switching between the spark ignition combustion using an ignition device and the compression ignition combustion which self-ignites a mixture by piston compression. Variable valve mechanisms vary at least one of the valve timings and valve lifts of an intake valve and an exhaust valve. Intake air is regulated to vary the amount of air intake into a combustion chamber on the upstream side of a combustion chamber inlet of the compression ignition internal combustion engine. The variable valve mechanisms and the intake air regulation are controlled during the compression ignition combustion so as to perform the compression ignition combustion.

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Hitachi, Japan

Yuusuke Kihara