| 摘要 |
PROBLEM TO BE SOLVED: To lighten labor required to prepare a map to compute a fuel injection quantity, and to eliminate a throttle valve. SOLUTION: The mass of air in a cylinder is computed from an engine speed and an intake air pipe pressure in accordance with a map to compute the mass of the air in the cylinder, and a target air-fuel ratio is computed from the engine speed and the intake air pipe pressure in accordance with a map to compute the air-fuel ratio. The mass of required fuel is computed by dividing the mass of the air in the cylinder by the target air-fuel ratio, and the fuel injection quantity is computed by multiplying it by the flow characteristics of an injector. The map to compute the mass of the air in the cylinder can be prepared only by measuring the mass by changing the engine speed and the intake air pipe pressure, and the map to compute the target air-fuel ratio can be set to a certain degree by the output characteristics of a required engine. When accelerating or reducing a speed, compensation for a transient period to shift the target air-fuel ration to the rich side or to the lean side is carried out.
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