Nissan Motor Company Limited

Tadashi Nagai

Ken Nakamura

Yutaka Matayoshi

Kunihiko Sugihara

Giichi Shioyama

Eiichi Ohnishi

Yoshimasa Hayashi

Yasuo Nakajima

Masaharu Asano

Sadao Takase

Junichi Yokoyama

Yoshifumi Hase

Atsushi Yonezawa

Shinichiro Sakurai

Masanori Takami

Fujihiko Deguchi

Makoto Ohguri

In a variable venturi carburetor in which the metering jet portion of fuel changes automatically according to the amount of intake air required to keep the mixture at a constant air-to-fuel ratio at all times, two series-arranged nozzles and an auxiliary fuel passage communicating with the downstream side of the venturi and with the space formed between the two nozzles additionally formed at the fixed venturi portion in such a way that the auxiliary fuel passage can be opened or closed according to engine operating conditions. Therefore, when the auxiliary fuel passage is opened, since fuel is introduced into the venturi through only a single nozzle, a rich mixture is obtained; when the auxiliary fuel passage is closed, since fuel is introduced through two nozzles, a lean mixture is obtained.

Variable venturi carburetor

In a prior-art variable venturi carburetor in which the cross-sectional area of venturi is automatically varied according to the amount of intake air to keep the flow rate of intake air or the vacuum generated at the venturi at a constant level, since the cross section of venturi changes rectangularly, fuel is concentratedly jetted only near the middle portion of the venturi, so that fuel is not uniformly mixed with air passing through the venturi. To overcome these drawbacks, a wall having a reverse trapezoidal recess is provided near the nozzle and further a pair of triangular slots or cutouts are formed near the lower end surface of the suction piston obliquely and symmetrically so as to slidably engage with the wall, with the result that the cross section of the venturi changes trapezoidally and therefore a stable mixture is obtained even when the engine is running at a low speed or being idled.

A spark-ignition internal combustion engine having a combustion chamber, comprises intake and exhaust valves disposed on a cylinder head wall surface and positioned generally symmetrical with each other with respect to the center axis of the bore of an engine cylinder, at least first and second squish areas which are located respectively in first and second sections of the combustion chamber which sections are defined by dividing the combustion chamber into two by a first vertical plane containing the centers of the intake and exhaust valves, and a spark plug whose tip section is disposed on the cylinder head wall surface and positioned in said first section of the combustion chamber thereby enabling use of high compression ratio without causing engine knock.

Spark-ignition internal combustion engine

An electronic controlled carburetor has an induction passage into which fuel is fed by a fuel metering system communicated with the atmosphere through main and auxiliary air bleed passages. The main and auxiliary air bleed passages have therein main and auxiliary solenoid valves, respectively, for altering the rate of air flow therethrough. A control circuit determines the duty ratio of a first pulse signal applied to the main solenoid valve in response to an air/fuel ratio indicative signal from an oxygen sensor. The control circuit determines the duty ratio of a second pulse signal applied to the auxiliary solenoid valve from the duty ratio of the first pulse signal so as to permit the main solenoid valve to operate around 50% duty ratio over all engine operating modes.

Electronic controlled carburetor

An additional oxidation catalyst containing section is disposed in engine exhaust gas passageway upstream of a reduction catalyst containing section in said exhaust gas passageway at a location downstream of which an oxidation catalyst containing section is disposed.

Exhaust gas catalytic converter system

An exhaust gas sensor is provided to generate a signal representing the air-fuel ratio within the exhaust system. The deviation of the air-fuel ratio from the average value of the sensor output is detected by a comparator. The time integral value is momentarily offset when the sensor reaches its operating temperature range so that the output from the comparator takes a definite value for quickly starting closed control operation.

Exhaust gas temperature detection for fuel control systems

An internal combustion engine has a cylinder head formed with a cooling liquid passageway and an air space. The cylinder head has a combustion chamber cooled by cooling liquid flowing through the passageway and an exhaust valve and exhaust port passage cooled by cooling air conducted by the air space. An insulating air space surrounds an exhaust port passage extending from the exhaust valve. As a result cooling effect by the cooling air on exhaust gas flowing through the exhaust port passage is reduced.

Internal combustion engine

A fuel injection system supplies fuel to only selected cylinders until the catalytic converter is heated sufficiently.

Catalytic convertor warming up system

In a control system installed on a motor vehicle and constituted of an oxygen concentration sensor and a control device for regulating the fuel supply rate to apparatus for preparing an air-fuel mixture on the basis of a signal from the sensor, a compensation circuit is inserted between the sensor and the control device, a resistance in which circuit varies as the engine is run every predetermined hours or the vehicle travels every predetermined distance.

Air-fuel ratio control system for automotive engine with compensation

A plurality of thermocouples or pressure responsive devices are provided in the exhaust system to detect a misfire in respective cylinders and the outputs of the thermocouples or pressure responsive devices are applied to a comparator for detecting the misfire. Alarm and fuel feed stopping devices are provided to operate when a misfire is detected.

Growing community of inventors

Yokosuka, Japan

Tadashi Nagai