Nissan Motor Company Limited

Tadaki Ota

Masaaki Saito

Katsushi Yoshikawa

Mitsumasa Inoue

Hiroshi Iwano

Tadahiro Yamamoto

Eiichi Ohnishi

Atsushi Yonezawa

Hiroshi Ogane

An apparatus for use in an internal combustion engine operable on either of gasoline fuel and gasoline-alcohol fuel blend. The apparatus includes an alcohol concentration sensor for sensing the alcohol concentration of the fuel to be delivered to the engine, and an oxygen sensor sensitive to the oxygen content in exhaust gases discharged from the engine for producing an air/fuel ratio feedback signal. A difference of the air/fuel ratio from the stoichiometric value is calculated based on the air/fuel ratio feedback signal for a closed loop air/fuel ratio control. A correction factor is used to correct the amount of fuel delivered to the engine so as to provide fuel enrichment during high engine load conditions. In the event of failure of the alcohol concentration sensor, the amount of fuel delivered to the engine is determined with the alcohol concentration being set at a predetermined value. When the engine is operating with an effective closed loop air/fuel ratio control after the alcohol concentration is set at the predetermined value, both of the correction factor and the ignition timing are determined based on the calculated air/fuel ratio difference. If the closed loop air/fuel ratio control is clamped after the alcohol concentration is set at the predetermined value, the ignition timing is determined on an assumption that gasoline fuel is delivered to the engine, whereas the correction factor is set to inhibit the fuel enrichment.

Apparatus for controlling engine operable on gasoline/alcohol fuel blend

An apparatus for controlling fuel delivery to an internal combustion engine having a plurality of cylinders each having an individual fuel injector. The apparatus comprises a sensor sensitive to an alcohol concentration of the fuel to be delivered to the engine for producing an alcohol concentration signal indicative of a sensed alcohol concentration. The apparatus also includes a control unit responsive to the alcohol concentration signal for controlling the duration of fuel injection from each of the fuel injectors to the corresponding cylinder. The control unit calculates a first time at which fuel injection to the corresponding cylinder is terminated and a second time at which fuel injection to the corresponding cylinder is initiated to ensure that the fuel injection will be terminated at the first time. The first time is varied according to the alcohol concentration.

Fuel injection control apparatus

A primary passage and a secondary passage in a parallel relation to each other are disposed between an air cleaner and a branch passage collecting portion of an intake manifold. The primary passage is smaller in diameter than the secondary passage and has at the downstream end thereof a laval nozzle through which air flows at the speed of sound even under low-speed low-load engine operating conditions. The laval nozzle is connected to a carburetion chamber which is elongated straightly in the direction downstream of the laval nozzle. A fuel injection valve is disposed in the primary passage at a place upstream of the laval nozzle. A pressure control valve is adapted so that a vacuum higher than a predetermined value is developed in the carburetion chamber at any time. A primary throttle valve and a secondary throttle valve are interconnected so that the secondary throttle valve is held closed unless the primary throttle valve is fully open. The primary throttle valve is movable in response to an engine operating condition.

Fuel supply system

A fuel injector valve comprises a main magnetic pole securely disposed within a casing and provided with an electromagnetic coil wound thereon, a valve seat member securely connected to the casing so as to be located opposite to the main magnetic pole tip section, a spherical valve member movably disposed within a valve chamber which is to be filled with fuel, and defined between the main magnetic pole tip section and the valve seat member, and an adapter member securely interposed between the main magnetic pole and the casing to secure the locational relationship therebetween, thereby securely achieving the locating and centering of the main magnetic pole.

Fuel injector valve

A carburetor is disclosed of the variable venturi type, which has a bypass passage bypassing the throttle valve, which is controlled during starting and warming up of the engine by a piston which adjusts its flow resistance, and which is urged against the biasing action of a spring by the vacuum suction downstream of the throttle valve. The maximum open position of this piston is controlled by a heat-sensitive element which advances this position in the direction of closing the bypass passage as the engine warms up, until it is completely closed when the engine is warm. Air is fed into a supplier which supplies fuel to the carburetor inlet passage to mix with the fuel supplied thereby in an amount which varies from a minimum when the vacuum downstream of the throttle valve is minimum to a maximum when the vacuum downstream of the throttle valve is maximum. Further, the amount of fuel supplied by the fuel supplier is adjusted to be greater when the engine temperature is lower than when it is higher. Thereby choking action is provided for a cold engine, and also a function of providing an enriched mixture upon acceleration during warming up is provided.

Carburetor with automatic choking and acceleration device

A carburetor with a circular air valve, in which the fuel metering needle is connected to a bracket on the downstream face of the air valve.

Variable air valve carburetor

A variable venturi carburetor is disclosed which includes a mixture conduit having therein a throttle plate, a fixed venturi, and a vacuum sustaining plate for variably opening and closing the throat of the fixed venturi. A first fuel nozzle opens into the mixture conduit at a point on the downstream side of the vacuum sustaining plate. An electromagnetic valve is provided for controlling the amount of fuel drawn from the auxiliary fuel nozzle so that it can vary in accordance with the degree of opening of the vacuum sustaining plate but is held at a level when the degree of opening of the vacuum sustaining plate is over a predetermined level. A second fuel nozzle is provided which opens into the mixture conduit at a point on the upstream of the vacuum sustaining plate for allowing discharge of fuel in amounts proportional to vacuums appearing in the mixture conduit upstream of the vacuum sustaining plate.

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Yokohama, Japan

Tadaki Ota