Hino Motors, Ltd.

Takatoshi Furukawa

Koichi Machida

Yoshihide Takenaka

Shinya Sato

Hideki Kato

Ichiro Tsumagari

Masatoshi Shimoda

Shotaro Iikubo

An engine control system controls an internal combustion engine so that some of a plurality of cylinders in a multi-cylinder internal combustion engine are made to rest and reduced-cylinder operation takes place. Each cylinder comprises a piston, an intake valve and an exhaust valve. In a resting cylinder during reduced-cylinder operation, when the piston moves downwards, the engine control system opens both the intake valve and the exhaust valve, and when the piston moves upwards, the engine control system opens the intake valve and closes the exhaust valve.

Engine control system

Excessive generation NOby oxidation catalyst arrangement upstream of a selective reduction catalyst is suppressed to prevent falling of NOreduction rate. A selective reduction catalystcapable of selectively reacting NOwith ammonia even in the presence of oxygen is incorporated in an exhaust pipefrom an engine. A pair of oxidation catalystsA andB are arranged in parallel with each other and upstream of the selective reduction catalyst. In an operation condition with low exhaust temperature, amounts of the exhaust gasdistributed to the oxidation catalystsA andB are adjusted so as to make NO/NOratio in the exhaust gasto about 1-1.5. In an operation condition with higher exhaust temperature where the NOreduction rate is less affected by the NO/NOratio, as a countermeasure against increasing, leaking ammonia, passage changeover is conducted to pass the exhaust gasin backflow through the selective reduction catalystand the oxidation catalystsA andB, so that ammonia passing through the selective reduction catalystwithout reacted is oxidized in the oxidation catalystsA andB.

Exhaust gas purification apparatus

Arranged within a cylindrical housing are capturing cells each including a cylindrical outer electrode capable of capturing particulates and an inner electrode inserted into the outer electrode and lined at its outer surface with a dielectric. A divergent exhaust unit is arranged on an end of the housing so as to guide exhaust to interiors in the respective capturing cells. A convergent exhaust unit is arranged on the other end of the housing so as to communicate with a gap between an inner surface of the housing and outer surfaces of the outer electrodes in the respective cells. The inner and outer electrodes are connected to an electric discharge controller.

Exhaust emission control device

Provided are a hollow inner electrode constituted by an electrically conductive filter capable of capturing particulates, a cylindrical outer electrode circumferentially surrounding the electrode, a housing incorporated in a flow passage of exhaust and accommodating the electrodes and, a temperature sensor for detecting temperature of the exhaust and an electric discharge controller for controlling electric power to be distributed to the electrodes and on the basis of a detected value of the temperature sensor. When the temperature of the exhaust obtained by the temperature sensor is lowered, electric power necessary for generation of discharge plasma is distributed by the discharge controller to the electrodes and, thereby oxidizing the particulates captured by the electrode to reduce electricity consumption.

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Hino, Japan

Takatoshi Furukawa