Nissan Motor Company Limited

Hitachi, Ltd.

Tadahiro Yamamoto

Tadaki Oota

Kenji Yoneda

Eiichi Ohnishi

Yuko Sugo

Yoshimasa Hayashi

Yoshishige Oyama

Yasuo Nakajima

Kenji Masaki

Masaaki Saito

Hiroshi Iwano

Kunihiko Sugihara

Minoru Osuga

Tadaki Ota

Atsushi Yonezawa

Motomi Arai

Ken Ota

Hiroshi Ogane

Hiroaki Oogane

A fuel injection system according to the present invention comprises a plunger disposed in a cylinder, an actuator in the form of a piezoelectric element for effecting reciprocation of the plunger, a fuel supply passage for admitting fuel to the cylinder, a plurality of pressurized fuel delivery passages for distributing pressurized fuel among a plurality of injection valves, solenoid valves for opening or closing the plurality of pressurized fuel delivery passages, and a control circuit for activating the actuator and the solenoid valves.

Fuel injection system

In an A/F ratio sensor of mixture supplied for an internal combustion engine, which has a detector for detecting the concentration of residual oxygen in exhaust gas and determines the A/F ratio by retrieving an air excess ratio table with an output of the detector, there is further provided an additional air introducing device, which introduces a predetermined quantity of air into the engine for a certain period of time, under the condition that the velocity of air flowing through a throttle valve is equal to the sonic velocity. The oxygen concentration detector is calibrated by the comparison of the outputs thereof before and after introduction of the additional air. According to this invention, the A/F ratio of the mixture can be detected accurately without the influence of the aged deterioration of the oxygen concentration.

Air/fuel ratio detecting apparatus for internal combustion engines

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 first temperature sensor senses the temperature of intake air supplied to an internal combustion engine before the intake air is mixed with fuel supplied thereto. A second temperature sensor senses the temperature of the mixture of the intake air and fuel within the intake air passage. A control unit controls the fuel injection quantity in accordance with the difference between the sensed temperatures, thereby causing the actual air-fuel ratio to coincide with a desired air-fuel ratio. The desired air-fuel ratio is adjusted in accordance with the throttling effect of a throttle valve in the intake air passage and with engine speed.

Fuel supply apparatus and method for internal combustion engines

A variable venturi carburetor comprises an auxiliary intake air passage, an auxiliary variable venturi and a non-adjustable nozzle portion, in addition to a main intake air passage, a main variable venturi and an adjustable nozzle portion. If the amount of intake air is small as when the engine is being idled, intake air is passed mainly through the auxiliary variable venturi to generate vacuum sufficiently high to jet fuel into the auxiliary intake passage through the non-adjustable nozzle portion. If the amount of intake air is great as when the engine is running under a heavy load, intake air is passed mainly through the main variable venturi. Since two venturis are formed, it is possible to smoothly increase the amount of fuel to be jetted into the intake passage over a wide engine operating condition.

Variable venturi carburetor

A single spot fuel injector is energized only twice per revolution of the crankshaft of the engine so that under given operating conditions the injections coincide with the TDC and BDC positions of a piston of a selected cylinder of the engine. Under higher engine speed operation, the injection timing is advanced to improve the fuel distribution to the cylinders. When the engine operates at an engine speed below a predetermined level it is possible for the injector to be energized three times per revolution of the crankshaft.

Method of operating a single spot fuel injected internal combustion

A disc having first and second sets of markers thereon is rotated in sychronism with the crankshaft of an engine so that pickups associated with the disc produce pulse trains of two and three pulses per revolution of the crankshaft respectively. A circuit responsive to either the speed or load of the engine selectively connects one of the pulse trains to a fuel injection control circuit to induce the fuel injector to inject in synchronism with the pulses of the selected pulse train. Alternatively the pulses outputted by the ignition system are frequency divided and fed to the fuel injection control circuit.

Single point fuel injected internal combustion engine and method of

An intake device for an internal combustion engine comprises an outwardly extending flange attached to a throttle barrel and a saucer-like member attached to the flange to form a ring-shaped intake passage therebetween. An air flow meter duct is arranged with the outlet disposed at the portion of the ring-shaped intake passage having the smallest cross-sectional area. The air flow velocity within the duct is equal to the velocity at this smallest cross-sectional area section, thus permitting measurement thereof by measuring the flow through the meter and scaling appropriately by the ratio of meter flow passage to intake passage cross-sectional areas.

Intake device for internal combustion engine

A Karman type air flow sensor element is disposed within a duct slidably mounted between members defining an annular space. The annular space causes the intake air to increase its velocity as it approaches the inner periphery of the annular space thus creating a pressure differential zone. By moving the duct so that the inlet and outlet are exposed to different high and low pressures respectively the pressure differential across said the inlet and outlet of the duct can be controlled to vary the fraction of the total intake air inducted therethrough.

Adjustable air flow sensor arrangement

A channel for recirculating a portion of an engine exhaust gas to the induction passage has an intermediately arranged converging-diverging supersonic nozzle with a valve member arranged in the nozzle to vary the cross-sectional area of the channel at the throat, so that the mass flow rate of the recirculated exhaust gas depends solely on the cross-sectional area so far as the gas velocity at the throat is sonic.

Exhaust gas recirculation system having flow control valve combined with

A sonic nozzle is formed in a recirculation passage interconnecting the exhaust line to the induction passage of an internal combustion engine and a valve member is arranged to vary the throat area of the nozzle, while the induction passage has a similar combination of sonic nozzle and a valve member. The control apparatus has a valve actuating mechanism arranged to link the respective valve members in the sonic nozzles with a common element which is necessarily moved when a change in the engine speed is intended, so that the throat area in the recirculation passage is varied always in direct relation to the throat area in the induction passage.

Flow rate control apparatus in exhaust gas recirculation system

A valve disposed in the central space of the manifold normally divides the space into two halves to avoid mutual interference of exhaust gas flows. At low engine speeds, the valve causes the exhaust gas flows from all branches to be disturbed and to mix with each other, to promote oxidation of HC and CO.

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Yokosuka, Japan

Tadahiro Yamamoto