Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Osamu Nako

Ryoji Nishiyama

Masaaki Miyazaki

Mitsuaki Ishii

Kouichi Yamane

Hiroyuki Nishizawa

Kimito Kashiwabara

A fuel injection device for an automotive internal combustion engine is disclosed, which comprises two distinct acceleration state determining means, i.e., a rapid and a slow acceleration state judgement means, for determining the amount of the asynchronous augmentation of fuel. The rapid acceleration state judgement detects the rapid acceleration state by comparing with a first threshold level the increment of the throttle opening degree over each period of an A/D conversion timing signal; the slow acceleration judgement means, on the other hand, detects the slow acceleration state by comparing with a second threshold level the increment of, for example, the throttle opening degree signal over, for example, two successive periods of the same A/D conversion time signal. When the rapid acceleration state is detected, an asynchronous augmentation of fuel for the rapid acceleration is effected. On the other hand, an asynchronous augmentation of fuel for the slow acceleration is effected only if: (1) the rapid acceleration state is not detected, and (2) the slow acceleration state is detected, over the two successive periods of the timing signal.

Fuel injection device for an internal combustion engine

A fuel injection device for an automotive spark ignition internal combustion engine provided with a supercharger is disclosed, wherein the amount of fuel injected in synchrony with the crank angle signal is determined on the basis of the intake air pressure. The increment of the air pressure data over each fuel injection period is compared with a first threshold level to determine the first augmentation. The pressure data is averaged over each fuel injection period, and the increment of the averaged pressure data over a predetermined interval of time is compared with a second threshold level to determine the second augmentation. The fundamental amount is calculated on the basis of either the instantaneous or the averaged pressure data, in dependency on the value of the first augmentation amount. The total amount of fuel that is to be injected in synchrony with every predetermined numberth pulse of the crank angle signal is calculated in each injection cycle as a sum of the fundemental amount and the first and the second augmentation when the engine is judged to be in the supercharged state; when, on the other hand, the engine is judged to not to be in the supercharged state, the total amount of fuel is calculated as the sum of the fundamental amount and the first augmentation alone. The supercharged state is detected when both the intake air pressure and the number of rpm of the engine are above respective predetermined levels.

A fuel injector for a spark ignition internal combustion engine is disclosed, wherein the amount of injected fuel is increased by an extra amount when the engine is in a transient accelerating state. The air pressure within the air inlet passage to the engine is detected by an air pressure sensor, and the load condition is judged by comparing the detected pressure with a reference level. Further, the variation or increment of the detected pressure over each fuel injection period is calculated and compared with a high or a low threshold level selected in accordance with the load condition of the engine. Preferably, the high threshold level is selected when the high load condition continues over a predetermined length of time, the low threshold level being otherwise selected. The amount of transient extra increase is determined in accordance with the result of the comparison of the pressure variation with the selectd threshold level. On the other hand, the fundamental amount of injected fuel is calculated on the basis of an instantaneous current air pressure when the above amount of transient extra increase is not zero; otherwise, on the basis of an average of the pressure over the fuel injection period. The sum of the fundamental amount and the transient increase is injected in synchrony with every predetermined number pulse of the crank angle signal.

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Okazaki, Japan

Osamu Nako