Nissan Motor Company Limited

Terunori Kondo

Naoya Tsutsumoto

Toshimasa Koga

Makoto Ohtake

Takao Inoue

Jun-ichi Kawashima

Junichi Kawashima

Shouichirou Ueno

Masahiko Nakano

Makoto Ootake

Munehiro Tabata

A particulate filter () which traps particulate matter in the exhaust gas of a diesel engine (), regenerates when a controller () performs an exhaust gas increase operation which includes decreasing the opening of an intake throttle (). The controller (), during regeneration of the filter (), determines whether or not the required load of the diesel engine () is increasing from an accelerator pedal depression sensor () or a fuel injection amount (S), and prevents output decrease of the diesel engine () by interrupting the exhaust gas temperature increase operation when the required load is increasing (S).

Regeneration of diesel particulate filter

A particulate filter regenerating device is configured to regenerate a particulate filter that collects particulate from engine exhaust gas. The particulate filter regenerating device is configured to prevent the temperature of the particulate filter from exceeding an allowable temperature during regeneration when the quantity of accumulated particulate is estimated to be lower than it actually is due to variation of the estimate. When the amount of temperature rise per unit time of the particulate filter is larger than a prescribed value during regeneration, it is determined that the temperature of the particulate filter will soon exceed the allowable temperature and the temperature rise amount &#x394;Texh of the exhaust gas is reduced (&#x394;Texhis the normal temperature rise amount). The larger the temperature rise per unit time is, the more the temperature rise amount of the exhaust gas is reduced.

Particulate filter regenerating device

A particulate filter regenerating device is configured to prevent the uneven distribution of particulate matter that results from interruption of the regeneration process and protect the particulate filter. The frequency with which regeneration is executed is increased by determining that it is time to regenerate the particulate filter at a time twhen the exhaust gas temperature Texhin has reached or exceeded a prescribed temperature TexhAdditionally, particulate filter regenerating device determines that it is time to regenerate the particulate filter when the quantity of accumulated particulate matter reaches or exceeds a prescribed value PMThe particulate filter is regenerated by raising the temperature of the exhaust gas and combusting the accumulated particulate matter.

An engine exhaust cleaning device is configured to prevent the temperature of a particulate matter filter (DPF) from rising sharply due to a reduction in the exhaust gas flow rate when a vehicle decelerates and shifts into idling operation during regeneration of the particulate matter filter. During regeneration of the particulate matter filter, the fuel cut (F/C) recovery engine speed used during deceleration is increased and the engine idling speed is increased for a prescribed amount of time when the engine idles.

Engine exhaust cleaning device

A filter () traps particulate matter contained in the exhaust gas of an engine (). The filter () is regenerated by burning the trapped particulate matter by raising the temperature of the filter (). When regeneration conditions are satisfied, a controller () raises the exhaust gas temperature to a first target exhaust gas temperature via an exhaust gas temperature adjusting mechanism () (S), and burns the trapped particulate matter to regenerate the filter (). When the engine () has rapidly decelerated during regeneration, the controller () decreases the exhaust gas temperature to a second target exhaust gas temperature lower than the first target exhaust gas temperature (S, S), and increases the exhaust gas flow rate (S), thereby preventing the filter () from exceeding an upper limiting temperature.

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Yokohama, Japan

Terunori Kondo