Abstract: A part of the air flowing through a main passage flows into a by-pass passage. A flow rate detector is provided in the by-pass passage. An outlet of the by-pass passage is opened at the narrowest portion of a venturi structure provided in the main passage. The by-pass passage is in communication with a pressure-accumulating chamber, which is in communication with the main passage at the portion thereof which is on the downstream side of the venturi structure. The pressure of the air flowing backward from the engine is stored in the pressure-accumulating chamber. The pressure in the pressure-accumulating chamber serves as a passage resistance with respect to the flow of the air in the by-pass passage. Accordingly, the flow rate detector permits determining the flow rate of the air, which does not contain a component representative of a backward flow of the air.

Abstract: A fuel injection apparatus in accordance with the invention has a hot wire type sensor disposed in a bypass air passage and adapted to sense the flow rate of air in the bypass air passage. In order to absorb the pulsation of air flowing in the bypass air passage, the bypass air passage opens at its one end to the air cleaner of an intake system disposed in a portion upstream from the hot wire sensor. An orifice is disposed in a portion of the bypass air passage downstream from the hot wire sensor.

Abstract: An air-fuel ratio controlling device for internal combustion engines, having a detector for a flow rate of the air supplied into a cylinder, a means for detecting a ratio of a flow rate of the air supplied into the cylinder to that of a fuel supplied thereinto, a control means for setting an air-fuel ratio to an optimum level on the basis of output signals from the air-fuel ratio detecting means and air flow rate detector, and a means for controlling the supplying of the fuel into the cylinder in accordance with an output signal from the air-fuel ratio control means. The air-fuel ratio detecting means has members for detecting the light generated by a flame in the cylinder and having at least two special wavelengths. The combustion condition corresponding to an air-fuel ratio in the cylinder is detected by the light-detecting members, and a signal representative of an actual air-fuel ratio is generated on the basis of outputs therefrom.

Abstract: A heat-type flow sensor is provided on the upstream side of a Venturi portion formed in an air-intake path and in an air bypass communicating with the Venturi portion. An electromagnetic device is provided to control the amount of air flowing in the air bypass so that the output of the heat-type flow sensor converges to a set level. This electromagnetic device drives a fuel-scaling valve to scale fuel in accordance with the change of the amount of air supplied to the engine, and this scaled fuel is continuously injected into the air-intake path.

Abstract: An electronic control apparatus for an internal combustion engine monitors suction air concentration and an engine operation condition, and applies these values to a control circuit to produce output signals to control the air-fuel mixture to be supplied to the engine. The control circuit calculates a desired mass air flow rate based on at least one parameter representing an operating condition of the engine when the throttle valve is fully closed and controls the actual mass air flow rate bring it the desired mass air flow rate.

Abstract: A method controls of the amount of fuel, ignition timing and the amount of exhaust reflux recirculation during transient operations of an internal combustion engine such as acceleration and/or deceleration. In this method, the present data of the intake air flow rate or intake negative pressure and previously-derived data with respect thereto are utilized to control the amount of fuel to be injected based on an extrapolation or correction method.

Abstract: An air intake measuring apparatus for an internal combustion engine comprises a bypass passageway formed in a throttle body by bypassing a venturi section in a suction passage, and a thermal probe arranged in the bypass passageway for determining the air intake by measuring the flow velocity of an air current flowing through the bypass passageway. A venturi member for forming in the throttle body the venturi section and the bypass passageway is force fitted in the throttle body to provide a unitary structure. The bypass passageway has an inlet port of a static pressure introducing type formed on the side of the suction passage and outlet ports formed in the venturi section close to the inlet port, while the thermal probe is located in the bypass passageway in a segment thereof of a minimum cross-sectional area.

Abstract: A fuel feeding apparatus for an internal combustion engine, in which a thermal type flow sensor is disposed in a bypass air path supplying bypass air from a point upstream of a Venturi portion formed in a main air-intake path to the Venturi portion, and the quantity of air flowing through the bypass air path is controlled by a solenoid unit so that the output signal of the thermal type flow sensor attains coincidence with a pre-set level. A fuel-metering valve actuated by the solenoid unit meters the quantity of fuel meeting a variation of the quantity of intake air being supplied to the engine so as to inject the metered quantity of fuel in a continuous flow into the main air-intake path. An oxygen sensor senses the concentration of oxygen in engine exhaust gases, and, on the basis of the output signal of the oxygen sensor, the value of the pre-set level is modified so that the rate of excess air in engine exhaust gases can be maintained to be .lambda.=1.

Abstract: An intake air amount detecting system which comprises:a temperature-dependent resistor disposed in an intake air path of an internal combustion engine;a sensor control circuit which feeds a heating current to the temperature-dependent resistor, which detects the change in resistance of the temperature-dependent resistor, which amplifies the detected signal, which effects the compensation depending upon the temperature of the intake air, and which controls the heating current in order to maintain the temperature of the temperature-dependent resistor constant; andan operation circuit which converts a signal that represents the heating current into an intake air flow rate;wherein the sensor control circuit is provided with a response-adjusting circuit which delays the response of the heating current only when the intake air flow rate decreases.

Abstract: A fuel injection system injects fuel to an internal combustion engine having a plurality of cylinders by means of a single fuel injector. For a four cylinder engine in which the suction stroke is repeated in the order of first, third, fourth and second cylinders, the single fuel injector responds to a control signal from a control system to initiate a single-shot injection upon the suction strokes of the first and the fourth cylinders. The fuel injection initiating timing as well as the injecting duration are arithmetically determined by a CPU a and ROM of the control system on the basis of the signals representative of operating conditions of the engine available from a hot-wire sensor, a crank angle detector, a temperature sensor, an O.sub.2 -sensor and supplied to the single fuel injector. The cylinders to which the fuel is to be injected are changed over from the first and fourth cylinders to the second and the third cylinders by the CPU in response to the signal output from the O.sub.2 -sensor.

Abstract: An intake barrel connected to an intake pipe of an internal combustion engine is provided therein with a venturi member. Openings are formed in the wall of the intake barrel at the upstream and downstream sides of the venturi member. A bypass passage forming member provided with a groove of a length greater than the distance between said openings is fixed to the outside of the intake barrel. A bypass passage is formed by these openings and the groove. A spacer is interposed between the intake barrel and the bypass passage forming member. The cross-sectional area of the bypass passage can be varied by varying the thickness of the spacer.

Abstract: An air flow meter comprises an air velocity measuring resistor and a temperature compensating resistor and is installed in a bypass passage provided at an intake passage running through an air horn. The air velocity measuring resistor and the temperature compensating resistor are supported by lead wires whose portions exposed in the bypass passage have the same length. A cover forming the bypass passage is made of heat insulating synthetic resin material to prevent heats from being transmitted to the resistors.

Abstract: An air flow rate sensor including a resistor the characteristic of which depends on temperature for operation mounted in a suction conduit of an internal combustion engine. The air flow rate sensor includes a tube of inorganic material, a platinum wire wound in convolutions on the surface of the tube, and a glass coating applied at least to the surface of the resistor while allowing a part of the surface to be exposed. The glass coating has a thickness smaller than the diameter of the resistor wire and enables equalization of pulsations of the sensor output to be obtained because of the thermal capacity of the glass coating.

Abstract: An electronic controlled carburetor includes sensors for sensing engine speed, intake air pressure and water temperature. An arithmetic unit digitally processes output signals from the sensors and generates signals for controlling the air-fuel ratio of a mixture supplied to an engine on the basis of the output signals from the sensors. The carburetor system includes means for sensing atmospheric pressure and intake air temperature, and means for adjusting at least one of the amount of intake air of the engine and the amount of fuel. The arithmetic unit digitally processes the output signals from the atmospheric pressure and the intake air temperature sensing means to thereby produce a signal representing air density change and automatically controls at least one of the amount of intake air and fuel on the basis of the air density changing signal, to thereby control the air-fuel ratio of the mixture with higher accuracy.

Abstract: A fuel control device for a fuel injection system of a type having an intermittent injection type fuel injector disposed in a bore formed in the wall defining an intake passage. The device has a porous tubular element received in the bore in close contact with the fuel injector and defining therein a passage opened at its both ends.The fuel injected by the fuel injector is adhered to the inner surface of the passage defined in the porous tubular element. Air is introduced into the passage through fine air passages formed in the wall of the porous tubular element. The air introduced into the passage well atomizes the fuel into fine particles and is mixed therewith to form a homogeneous mixture.

Abstract: An electronically-controlled carburetor is disclosed. This electronically-controlled carburetor is provided with a control fuel path in addition to a main fuel path opened to the venturi of the air horn. This control fuel, after being introduced to a constant pressure chamber regulated at a constant pressure, is further introduced to the air horn through a sonic flow nozzle provided at the opening of the constant pressure chamber, together with the control air introduced to the constant pressure chamber. The amount of the control fuel introduced to the air horn and the amount of the control air are regulated on the basis of control electrical signals generated by an electronic control circuit supplied with data indicative of engine running conditions. In this way, the air-fuel ratio is properly controlled over the entire range of engine running conditions.

Abstract: An apparatus for measuring the flow rate of suction air in an internal combustion engine in which the heat radiation characteristic of a heat generator disposed in the suction air passage, which characteristic varies with the lapse of time due to dust and like foreign matters depositing on the heat generator, is calibrated on the basis of the air flow rate value measured by an air flow rate measuring device of differential pressure type so as to insure accurate measurement of the suction air flow rate.

Abstract: A control system including a microprocessor for controlling the controlled variables of an internal combustion engine, especially, the flow rate of fuel is disclosed. An air flow meter provides an output signal having such a non-linear characteristic relative to the flow rate of intake air that the signal level increases in the region of the small flow rate of intake air. The microprocessor carries out necessary digital computation on the basis of the output signal of the air flow meter to provide a fuel flow rate control signal. This digital control signal is converted into a signal having a linear characteristic proportional to the flow rate of intake air, or after having been produced from the microprocessor, converted into a signal including information proportional to the flow rate of intake air.

Abstract: An air to fuel ratio control system for an internal combustion engine having a fixed venturi type carburetor is disclosed. The air to fuel ratio control system comprises a device for extracting an atmospheric pressure within a venturi or a pressure corresponding to a relieved venturi vacuum, a device for extracting a static fuel pressure downstream of a main jet provided in a fuel path, a device for comparing those pressures directly or indirectly and a device for controlling the static fuel pressure in accordance with an output of the detecting device. Control is made such that the difference between those pressures is always maintained substantially constant. The air to fuel ratio control system may further comprise a device for detecting composition of exhaust gas of the engine.

Abstract: An apparatus for the optimum control of a combustion engine, which is capable of compensating for the change in the combustion engine with time caused by mechanical wear. An optimum control value is stored in a memory. The data stored in the memory is compared in a microcomputer with an output from at least one sensor for detecting the operating conditions of the combustion engine, so that the optimum control signal for the present operating conditions is applied to the control apparatus for the combustion engine. In response to an output from a combustion pressure sensor for detecting the change with time of the combustion engine, calculations for correcting the data in the memory are conducted, followed by the updating of the data therein.