Nissan Motor Company Limited

Hikari Todoroki

Takashi Shirakawa

Yasutaka Ishibashi

Hiroyuki Itoyama

Manabu Miura

A diesel particulate filter () which traps particulate matter and a NOx trap catalyst () which traps nitrogen oxides are installed in series in an exhaust passage () of a diesel engine (). A controller () calculates a particulate matter deposition amount in the diesel particulate filter () (S). The controller (), when the particulate matter deposition amount exceeds a first predetermined amount (PM), prevents sharp increase of the particulate matter deposition amount by prohibiting rich spike where the oxygen concentration of the exhaust gas is controlled to a value corresponding to a rich air-fuel ratio in order to regenerate the NOx trap catalyst () (S, S, S), and prevents the particulate matter deposition amount of the diesel particulate filter () from reaching a limit.

Exhaust gas purification control of diesel engine

A controller () controls the boost pressure of an internal combustion engine () comprising two intake/exhaust units, each intake/exhaust unit comprising a turbocharger () which supercharges intake air in an intake passage () using exhaust energy in an exhaust passage (), and an exhaust gas recirculating device () which recirculates a part of the exhaust gas in the exhaust passage to the intake passage. The controller () calculates an opening difference between valves in the two units (S), and controls a regulating device () in each of the two units on the basis of this opening difference (S-S). As a result, the boost pressures of the turbochargers () match, and hence an equal amount of NOx can be discharged from each exhaust passage (), and the NOx can be purified favorably by a catalyst.

Engine boost pressure control

In order to prevent the generation of surge noise or other abnormal phenomena during deceleration of a vehicle, the present engine control apparatus comprises a turbo-supercharger driven by exhaust energy of the engine, at least one of an NOtrap catalyzer and a DPF mounted in the exhaust path of the engine for purifying the exhaust, an EGR path interconnecting the exhaust path and the inlet path of the engine, an EGR valve for adjusting the cross-section of the duct of the EGR path, means for detecting deceleration, and a fuel cutoff control means that, if predetermined conditions are satisfied, effects fuel cutoff control to reduces the rate of fuel injection, wherein the EGR valve is closed during the period of vehicle deceleration.

Engine control apparatus

In a combustion control system of an engine employing an exhaust purifying device, a control unit determines, based on an operating condition of the exhaust purifying device, whether a request for an exhaust temperature rise is present. The control unit executes, by way of fuel injection control in presence of the request of the exhaust temperature rise, a split retard combustion mode in which a main combustion needed to produce a main engine torque and at least one preliminary combustion occurring prior to the main combustion are both achieved, and the preliminary combustion occurs near top dead center on a compression stroke, and the main combustion initiates after completion of the preliminary combustion. The control unit executes a fail-safe process that an injection timing of main fuel injection is phase-advanced, when a predicted temperature value of the exhaust purifying device exceeds a predetermined threshold value.

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Fujisawa, Japan

Hikari Todoroki