Abstract: An air-to-fuel ratio control system, for properly supplying additional air through an additional air passage to the intake port of the internal combustion engine depending on a detected air-to-fuel ratio of the mixture, includes a drive unit having two main pressure chambers divided by a main diaphragm and an auxiliary pressure chamber separated by an auxiliary diaphragm from one of the main chambers. The main and auxiliary diaphragms are connected by a rod to a bypass valve mounted in the additional air passage to increase or decrease the passage area by the movement of the bypass valve. In response to an air-to-fuel ratio detection signal, the intake port vacuum (or the atmosphere) is introduced to either one of the main chamber while the other chamber is occupied with the atmosphere or the intake port vacuum thereby to produce a pressure difference between the two main chambers.

Abstract: An air-fuel ratio adjusting system controls the amount of additional air supply through the bypass passage of the carburetor to ensure optimum engine operation even in a warming up condition of the engine. The air-fuel ratio adjusting system includes an air-fuel ratio sensor disposed in the exhaust manifold, a warm-up sensor for detecting the temperature of engine cooling water or engine block, and a control unit for providing a control signal to a driving motor for the bypass valve. The bypass valve is controlled so that the air-fuel ratio of the mixture becomes the stoichiometric one and at the same time, during the warming up condition, the maximum opening of the bypass valve is limited to a predetermined degree depending on the temperature of the engine.

Abstract: In an air-fuel ratio adjusting system for an internal combustion engine equipped with a carburetor having a bypass air passage for controlling an air-fuel ratio of an air-fuel mixture to be supplied to the engine, a bypass valve disposed in the bypass passage is so arranged as to move during no-load running of the engine at a speed lower than that during the normal running of the engine under the load, thereby to prevent disadvantages such as the engine stall.

Abstract: A system for controlling an air-to-fuel ratio of a gas mixture supplied to a vehicle engine to a correct valve is disclosed. In response to an output signal from a discriminator circuit which receives as inputs thereto a signal from an air-to-fuel ratio detector mounted in an exhaust pipe and simultaneously in response to a signal from an aperture detector which detects the aperture of a control valve mounted in an adjusting air path provided parallel to a carburetor, a pulse motor for adjusting the aperture of the control valve provided in said air path is driven to obtain a correct air-to-fuel ratio.

Abstract: An air-to-fuel ratio controlling system for an internal combustion engine is provided with a deceleration detector for detecting the deceleration operation of the engine. In response to a signal delivered from the deceleration detector, a control valve mounted in the adjusting air path is maintained at a given valve angle for a predetermined period of the deceleration. Air is, thus, additionally supplied through the adjusting air path during the deceleration, thereby to prevent unduely rich of the air-fuel mixture during the deceleration and to enable the control of the air-to-fuel ratio properly.

Abstract: An additional air control device for an internal combustion engine wherein an additional air supply to the engine is controlled by controlling the operation of a drive motor coupled to a control valve mounted in a bypass passage. The driving direction of the drive motor to open or close the control valve is controlled by a gas sensing signal representing the content of the exhaust gas and generated by a gas sensor, and the duty ratio between the drive time period .tau.a and the rest time period .tau.b of the drive motor is controlled depending on an intake air flow signal representing a delay time factor from an intake air flow meter. In deceleration operation of the engine, the duty ratio .tau.a/.tau.b is increased independently of the intake air flow signal by a deceleration signal produced by a deceleration detecting switch. The drive motor is thus controlled to drive in a skip movement fashion and to stop alternately with the duty ratio of .tau.a/.tau.

Abstract: In an air-fuel ratio adjusting system for internal combustion engine equipped with a carburetor having a bypass air passage for controlling an air-fuel ratio of an air-fuel mixture to be supplied to the engine, a bypass valve disposed in the bypass passage is so arranged as to be restored to its preset position, at which the air-fuel mixture with a proper air-fuel ratio is produced, whenever the engine is stopped, to thereby ensure a smooth starting of the engine even under the low temperature condition.

Abstract: In an air-fuel ratio controlling device which comprises an exhaust gas sensor for detecting the air-fuel ratio of mixture and an additional air passage including a bypass valve and disposed to supply additional air to the downstream side of the throttle valve of an engine, the controlling device further comprises a throttle sensor operatively connected to the throttle valve for producing an output signal corresponding to the opening of the throttle valve, and a control circuit responsive to the signal from the throttle sensor whereby a predetermined time period after the occurrence of a change in the opening of the throttle valve is discriminated as the acceleration or deceleration period of the engine and the bypass valve is driven at one or the other of two speed depending on whether the engine is in the accleration/deceleration operating condition or other operating conditions.

Abstract: An additional air control device for maintaining constant air-fuel ratio in an internal combustion engine wherein an intake air which is supplied additionally through a bypass passage to the engine is controlled by controlling the movement of a drive motor coupled to a control valve mounted in the bypass passage. A gas sensor for sensing the oxygen content of the exhaust gas and an intake air flow meter for sensing the rate of intake air flow to the engine are provided.

Abstract: In controlling an amount of intake air of an internal combustion engine, an error due to the delay time between the time at which the air-fuel ratio changes in the intake system of the engine and the time at which a gas sensor in the exhaust system of the engine senses the changes is compensated. At least two delay factor detectors, e.g., an engine speed sensor and a pressure sensor control the driving and stopping of a drive motor coupled to a control valve mounted in the additional air passage in the intake system to thereby adjust the amount of additional air supply.

Abstract: In an air-to-fuel ratio adjusting system for an internal combustion engine which comprises an additional air supply passage communicating with the carburetor of an internal combustion engine at the position downstream of its throttle valve, a control valve disposed in the additional air supply passage to vary the passage area thereof, and a percolation sensor for detecting percolation phenomenon of the fuel during idling operation of the engine is provided. When the occurrence of a percolation phenomenon is determined in accordance with the output signal of the percolation sensor, the control valve is controlled in response to the output signal of an air-to-fuel ratio sensor, whereas the control valve is held in a predetermined valve position when there is no occurrence of percolation phenomenon during idling operation of the engine.

Abstract: A carburetor for applying air-fuel mixture to an internal combustion engine includes a main passage for applying air-fuel mixture and principally controlling the amount thereof.The air-to-fuel ratio of the air-fuel mixture to be supplied to the engine is detected by an air-to-fuel ratio detector mounted in an exhaust pipe of the engine, and when the detected ratio is lower than a stoichiometrically optimum air-to-fuel ratio for perfect combustion of the air-fuel mixture additional air is supplied to the main passage through a bypass passage, the amount of which is controlled by a bypass valve mounted in the bypass passage.An intake air pressure detecting device is mounted in an intake pipe of the engine, and when the detected pressure (absolute pressure) in the intake pipe becomes higher additional fuel is supplied to the main passage through an auxiliary fuel jet provided in the carburetor.

Abstract: There is provided a fuel injection system for an internal combustion engine comprising fuel injection means provided for each of the cylinders of the engine, a main computing circuit for determining the timing of the injection and the duration of the injection in accordance with the charging and discharging of electric energy corresponding to the number of revolutions of the engine and the quantity of air drawn thereinto and generating pulse signals, a distribution circuit for distributing the pulse signals to the fuel injection means, and a reference signal generating circuit for generating an electric signal to complete the charging of electric energy in the main computing circuit within 720.degree./(2 .times.

Abstract: A fuel injection system for an internal combustion engine of a type in which a stratified charge of rich air-fuel mixture and lean air-fuel mixture is supplied into the combustion chamber of each cylinder. The fuel injection system includes an electronic control unit whereby when air flow is decreased fuel is sequentially injected into the respective cylinders in accordance with their firing order, whereas when the air flow is increased the fuel is simultaneously injected into all the cylinders.

Abstract: An air-to-fuel ratio control means provided in a carbureter of an automobile, in which control means a control valve for controlling the rate of flow of compensating air or compensating fuel is provided. Also, a drive means is provided to fix the control valve at positions at which an optimum air-to-fuel ratio is obtained depending upon the engine operating conditions, namely at the time of cold starting, under low-load low-speed and high-load high-speed engine operating conditions.

Abstract: An overheat preventing system is provided for a vehicle exhaust gas purifier. The system comprises a temperature detector mounted in the locality of each of the exhaust ports of an engine, an overheat detector for detecting failure of an engine to fire from the temperature signals generated by the temperature detectors and for generating a signal, and an actuator for preventing the overheating of an exhaust gas purifier which is adapted to be operated upon the generation of the overheat signal from the overheat detector, whereby unburned gases are prevented from flowing into the exhaust gas purifier.