Nissan Motor Company Limited

Jun-ichi Kawashima

Naoya Tsutsumoto

Toshimasa Koga

Terunori Kondo

Makoto Ohtake

Takao Inoue

Terunori Kondou

Makoto Otake

Shouichirou Ueno

Masahiko Nakano

Munehiro Tabata

A regeneration control device which regenerates a filter () which traps particulate matter in the exhaust gas of an engine () is disclosed. The regeneration control device includes a first temperature sensor (), which detects one of an upstream temperature and a downstream temperature upstream and downstream of the filter () as a first temperature (Tin, Tout); a second temperature sensor (), which detects the other temperature as a second temperature (Tin, Tout); and a microcomputer. The microcomputer programmed to compute an estimated value (Tbede) for the second temperature based on the first temperature detected by the first temperature sensor (), compute an estimated bed temperature (Tbed) of the filter based on the second temperature detected by a second temperature sensor () and the estimated value (Tbede) for the second temperature, and perform engine control for increasing the temperature of the exhaust gas based on the estimated bed temperature (Tbed).

Filter regeneration control

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.

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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Yokosuka, Japan

Jun-ichi Kawashima