Isuzu Motors Limited

Isuzo Motors Limited

Suzuhiro Saiki

Tadashi Uchiyama

Futoshi Nakano

An engine operation control device which sets higher than the target revolution speed for the idling state the target revolution speed of the engine immediately after the engine operation has shifted to the idling state, to prevent troubles caused by bubbles in the working fluid. When the engine operation shifts to the idling state at time t , the count value Cnt of the idling counter starts counting. When the count value Cnt reaches the set value Cnt , the revolution speed correction amount Nad is added to the target revolution speed for the idling state. The correction amount Nad progressively decreases with the elapse of time after the engine operation has shifted to the idling state. Because the fuel injection is performed in such a manner as to produce a higher target revolution speed than normal, it is possible to suppress the generation or expansion of bubbles that would otherwise occur under reduced pressure in the injectors used in the fuel injection system as a result of engine operation shift to the idling state.

Engine operation control device

A fuel-injection system for an engine is disclosed in which a standard conductive duration of the individual injectors required for a desired volume of fuel injected per cycle may be easily provided by correcting a standard conductive duration to a solenoid-operated valve, which has been found depending on a standard fuel-injection characteristic. A controller unit is stored with a standard fuel-injection characteristic A that is used for obtaining a standard actuating pulse width Pws for the standard conductive duration corresponding to a desired volume Qf of the injected fuel, which is required depending on the operating conditions of the engine. A specified operating point (Q,, Pw,) is a known data that has been previously observed for the individual injectors. The actuating pulse width Pw necessary for determining the desired volume Qf of injected fuel is given by multiplying the standard actuating pulse width Pw,by a correction coefficient that is a ratio of the standard actuating pulse width Pws,to the specified actuating pulse width Pw,. The correction coefficient is computed at plural selected pressure ranges of a hydraulically actuated fluid while the process of interpolation provides the correction coefficient at the residual pressure ranges. This makes it possible to eliminate the stoop change of the correction coefficient K with the result of the protection of the engine from torque-shock.

Fuel-injection system for engine

An engine operation control device which sets higher than the target revolution speed for the idling state the target revolution speed of the engine immediately after the engine operation has shifted to the idling state, to prevent troubles caused by bubbles in the working fluid. When the engine operation shifts to the idling state at time t,, the count value Cnt of the idling counter starts counting. When the count value Cnt reaches the set value Cnt,, the revolution speed correction amount And is added to the target revolution speed for the idling state. The correction amount And progressively decreases with the elapse of time after the engine operation has shifted to the idling state. Because the fuel injection is performed in such a manner as to produce a higher target revolution speed than normal, it is possible to suppress the generation or expansion of bubbles that would otherwise occur under reduced pressure in the injectors used in the fuel injection system as a result of engine operation shift to the idling state.

An electronic fuel injection apparatus for a diesel engine comprising a driving state detection means for detecting a driving state of a vehicle and a controller for periodically determining a target injection quantity based on the driving state. When the driving state detection means indicates a state in a short time after engine start, a correction quantity which is preset to be added to the target injection quantity according to the engine temperature detected as the driving state is decreased, depending on time after engine start.

Electronic fuel injection apparatus for diesel engine

An electronic fuel injection apparatus for a diesel engine comprising a driving state detection means for detecting a driving state of a vehicle associated with an automatic transmission and a controller for periodically determining a target injection quantity based on the driving state. The target injection quantity at a time when a gearshift position is in a driving position is set to a driving target injection quantity which is obtained by adding a predetermined correction quantity to a target injection quantity at a time when the gearshift position is in a non-driving position. When the change of the gearshift position from the non-driving position to the driving position is detected, the target injection quantity is increasingly corrected to the driving target injection quantity.

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Kanagawa, Japan

Suzuhiro Saiki