Nippondenso Co., Ltd.

Toyota Jidosha Kogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Motoharu Sueishi

Masumi Kinugawa

Hironobu Ono

Kazuo Ueda

Shuzo Yoshida

Norio Omori

Susumu Harada

Masashi Matsuo

Hiroki Matsuoka

Hiroshi Takahashi

Hideya Fujisawa

Yukio Suzuki

Kunio Endo

Mitsuo Nakamura

Katsushi Kato

Susumu Nogami

Yoshiaki Sato

Junji Kawarada

Kouich Hoshi

A fuel injection system for internal combustion engines injects fuel simultaneously into cylinders at a controllable number of occurences of fuel injection. The fuel injection system includes a frequency divider for frequency-dividing a signal indicative of rpm of the engine, a gate means for selectively supplying an output from the frequency-divided signal to solenoid-operated fuel injection valves, and a comparator for controlling the gate means to feed the output from the frequency-divider to the fuel injection valves when a signal indicative of an engine load exceeds a reference value upon comparison, that is, when the engine operates under heavier loads.

Fuel injection system for internal combustion engine

During starting of an engine, enrichment correction according to engine starting enrichment is executed. After starting of the engine, enrichment correction is transferred gradually with the lapse of time from starting enrichment to normal warm-up enrichment. The transfer speed from starting enrichment to normal warm-up enrichment is changed depending upon whether a throttle valve is in an idle position or not.

Method and apparatus for controlling the fuel feeding rate of an

An air-fuel ratio feedback control system for the internal combustion engine produces a fuel supply control signal by delaying a rich or lean signal obtained by comparing the oxygen concentration in the exhaust gas with a reference value. The turning on of an idle switch operatively connected with the engine throttle valve, a predetermined time after the turning off of the idle switch and the engine speed included in a predetermined region are detected in order to delay the rich or lean signal to rich or lean side by an optimum delay time as selected according to the engine operating conditions, thus feedback controlling the amount of fuel supply.

Air-fuel ratio feedback control system

An air-fuel ratio feedback control system is disclosed in which a sensing output representing the oxygen concentration in the exhaust gas of an internal combustion engine is compared with a predetermined set value. The output of the comparator is integrated and the amount of fuel injection is corrected by being increased or decreased in accordance with the integration output having an increasing or decreasing polarity so as to control the air-fuel ratio at a stoichiometrical value. At the time of engine start, the air-fuel ratio feedback control is stopped, and this condition is held after engine start. Further, the holding function is cancelled by a signal representing the activation of the detection output of the oxygen sensor.

A method for controlling the rotational speed of a combustion engine which drives an automotive vehicle by computing the actual and desired values of the idle rotational speed of the engine, computing a control amount corresponding to the difference between the actual and desired values and controlling the amount of air or the amount of mixture supplied to the engine in accordance with the control amount. The desired value and the upper and lower limit values of the control amount are changed in accordance with a plurality of operating parameters including the condition of a brake switch.

Method and apparatus for controlling engine rotational speed

The amount of secondary air flowing through a bypass air passage bypassing the throttle valve of an engine, which is connected to an automatic transmission of a vehicle having an air-conditioner, is controlled by an air control valve disposed in the bypass air passage. The air control valve is controlled on the basis of the result of comparison between a signal indicative of the actual idling rotation speed of the engine detected by the distributor of the engine and a reference signal indicative of a desired idling rotation speed of the engine. The level of this reference signal indicative of the desired idling rotation speed of the engine varies depending on the on-off of the air-conditioner in the vehicle or on the position of the shift lever of the automatic transmission.

Apparatus for controlling rotation speed of engine

A system for controlling the amount of air taken in by an engine comprises an air duct tube bypassing a throttle valve of an intake tube for taking in air supplied to an automobile engine, a plurality of valves for regulating the amount of air passing through the air duct tube, and control device therefor. The amount of air in the bypass is controlled in accordance with the temperature and number of revolutions of the engine and the air intake pressure downstream of the throttle valve. During the idling of the engine, the air intake control system generates a signal representing the standard engine idling revolutions in accordance with the engine temperature, compares the actual engine revolutions with a reference, and regulates the amount of air flowing in the bypass by use of the results of a comparison, thus rendering the actual engine revolutions identical to the reference. During the loaded engine operation, by contrast, the amount of bypass air is so controlled that the air intake pressure downstream of the throttle valve is maintained at predetermined constant value.

Engine air intake control system

The combination of a fuel supply system for an internal combustion engine, an exhaust gas oxygen concentration sensor and a feedback control system including an integration circuit connected to the fuel supply system and a correction control circuit connected to the exhaust gas oxygen concentration sensor and the integration circuit. The combination controls the air-fuel mixture to be supplied to an engine in accordance with an integration output signal, which in turn is generated from the output signal generated by the exhaust gas oxygen concentration sensor. The correction control circuit serves to disconnect the exhaust gas oxygen concentration sensor from the integration circuit when a predetermined operating condition of the engine is reached, thereby holding the output from the integration circuit constant.

An electronically controlled fuel injection system mounting an oxygen content detector in the exhaust system of the engine comprises at least two kinds of fuel injection valve, one of which has a different injection opening from the other, whereby an optimum air-fuel ratio for reducing harmful components in the exhaust gas from the engine is obtained.

Electronically controlled fuel injection system

There is provided an air-fuel ratio control system for internal combustion engines wherein the direction of deviation of the actual air-fuel ratio from a preset air-fuel ratio is determined by an oxygen concentration detector for detecting the concentration of oxygen contained in the exhaust gases from an internal combustion engine and an air-fuel ratio discriminating circuit, whereby air is injected from an air injection valve when the air-fuel ratio is low i.e. the mixture is rich and fuel is injected from a fuel injection valve when the air-fuel ratio is high i.e. the mixture is lean, thereby controlling the air-fuel ratio to a predetermined value.

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Toyota, Japan

Motoharu Sueishi