Abstract: An air-fuel ratio control system for an internal combustion engine comprises an induction passage, a carburetor, an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied to the carburetor, an O.sub.2 -sensor for detecting oxygen concentration of exhaust gases, and a feedback control circuit responsive to the output of the O.sub.2 -sensor for producing pulses for driving said electromagnetic valve for correcting the air-fuel ratio.An engine speed detecting circuit is provided for producing an output signal which varies with the engine speed; and a frequency changing circuit is provided to be responsive to the output signal of the engine speed detecting for changing the frequency of the pulses whereby the electromagnetic valve may be prevented from resonating with the vibration of the engine and with the pulsations of induced air.

Abstract: A method for controlling the air-fuel ratio in a carburetor which prevents fuel from flowing into an air bleed passage at nearly fully closed position of the tapered needle valve fitted with the air bleed passage by controlling the step motor connected to the needle valve so as to maintain the minimum amount of bleed air at a constant level. In another aspect, at nearly fully closed position of the needle valve, this invention is effective to prevent fuel from flowing into the air bleed passage by continously driving the step motor in a direction of its fully closed position to axially vibrate the needle valve so that the minimum amount of bleed air may be maintained at a constant level.

Abstract: Apparatus (1) for controllably opening the choke valve (V) of a carburetor (C). An actuator (3) is supplied signal elements of an electrical command signal. The actuator is responsive to the command signal elements to move a choke shaft (S) and open the choke valve. A spring (13) is connected to the actuator and the choke shaft to exert a choke valve opening force on the choke shaft when command signal elements are supplied to the actuator. A sensor (21) senses the temperature of the engine and generates an electrical signal representative thereof. A processor (23) processes the electrical signal from the sensor and generates and supplies signal elements of the electrical command signal to the actuator if the engine temperature represented by the electrical signal is less than a predetermined engine temperature. The choke valve is fully opened when engine temperature reaches the predetermined temperature.

Abstract: Disclosed herein is an apparatus for supplying fuel to an internal combustion engine. The apparatus comprises an air regulator located at an air passage between a nozzle and an air pump for generating an air pressure P.sub.a and maintaining a pressure differential between pressure in an air intake passage and the air pressure P.sub.a at a predetermimed value corresponding to engine operations, a fuel regulator located at a fuel passage between the nozzle and a fuel pump for generating a fuel pressure P.sub.f and maintaining a pressure differential between pressure in the air intake passage and the fuel pressure P.sub.f at a predetermined value corresponding to engine operations, an air sensor for sensing the amount of suction air to the air intake passage and outputting a signal corresponding to the amount of suction air, a computer for receiving the signal from the air sensor and outputting a signal corresponding to a predetermined pressure differential between the air pressure P.sub.

Abstract: A fuel supply system for a mixture-compressing internal combustion engine employs a controllable differential pressure for the removal of air from a main air duct into a carrier air duct for proportioning the fuel to be used. The fuel system includes a fuel proportioning device and a vane pump for withdrawing a carrier air flow from the main air duct and for transporting the fuel through feed lines to the internal combustion engine. The pressure of the air at the fuel outlet and the differential pressure for fuel proportioning is controlled by a differential pressure valve located in the carrier air duct spaced from the main air duct. The differential pressure valve has a diaphragm dividing the interior of the valve into chambers with one side of the diaphragm acted upon by the air pressure in the carrier duct between the differential pressure valve and the main air duct.

Abstract: A system for controlling the air-fuel ratio in which the amount of fuel injected into the engine is controlled in accordance with the flow rate of air passing through an air intake pipe including a throttle valve for introducing the air into the engine and the engine operating conditions. A bypass of the air intake pipe is opened or closed to change the air-fuel ratio of the mixture to slightly richer and leaner sides of a basic air-fuel ratio, and the change of the engine output conditions based on the change of the air-fuel ratio is used to correct the air-fuel ratio in an optimum direction. On the basis of a parameter indicating the engine operating conditions such as the detection value of the intake pipe pressure, a control is made to introduce the air which passed through the bypass to one of the upstream or downstream portion of the throttle valve.

Abstract: A combined accelerator pump and cold start fuel/air mixture supply device has an automatic throttle valve in a mixture supply passage, a fuel control valve controlling flow of fuel drawn into the passage through an inlet upstream of the throttle valve, and an air valve upstream of the fuel inlet. A primary spring tends to seat the air valve. A light, secondary spring urges a plunger against the air valve to augment the load of the primary spring for a predetermined time interval after the engine begins to run under its own power. A valve in a pipe opens automatically at the end of the predetermined time interval to apply engine inlet manifold depression to the end of the plunger remote from the air valve and thereby to separate the plunger from the air valve so that only the primary spring acts on the air valve.

Abstract: An air-fuel ratio control system for a vehicle powered by an internal combustion engine having an emission control system with a three-way catalytic converter for controlling the air-fuel ratio in accordance with the operation of the engine. A vacuum sensor detects heavy load operation of the engine, and an engine speed detecting circuit and a predetermined voltage supply circuit are provided. The engine speed detecting circuit is so arranged as to produce an output when the engine speed is lower than a predetermined value. A feedback control circuit is provided for controlling the air-fuel ratio to the stoichiometric air-fuel ratio in normal operating conditions. A first switch device is actuated by the output of the vacuum sensor to connect the output of the predetermined voltage supply circuit with the input of the feedback control circuit when heavy load operation is detected and to render the feedback control circuit inoperative.

Abstract: An electric control system for controlling an internal combustion engine, which comprises sensor means for detecting at least one of operating condition of the engine and ambient condition in the vicinity of the engine to generate an output continuously variable with a change in the above at least one condition, comparator means for comparing the output of the sensor means with upper and lower limits which are set at values lying slightly beyond a normal range of values indicative of the at least one condition which can exist during normal operation of the engine, and generating a first signal when the output of the sensor means lies beyond the upper limit or the lower limit; and a timer arranged to generate a second signal is continuously generated over a predetermined period of time. The electric control system includes an air/fuel ratio control system for internal combustion engines.

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: Additional increment of the fuel feeding rate of an internal combustion engine during starting and for a period of time after starting is determined depending upon the warm-up condition of the engine and furthermore upon the rotational speed of the engine. The higher the rotational speed, the smaller the additional increment, and vice versa.

Abstract: A carbureting type fuel metering apparatus has a primary and secondary induction passage into which fuel is fed by several fuel metering systems among which are primary and secondary main fuel metering systems and an idle fuel metering system, as generally known in the art; engine exhaust gas analyzing means sensitive to selected constituents of such exhaust gas creates a feedback signal which through an associated solenoid transducer becomes effective for controllably modulating the metering characteristics of the main fuel metering system systems, and, if desired, the idle fuel metering system as to thereby achieve the then desired optimum metering function; the solenoid transducer is shown as simultaneously controlling two valving members and is effective upon experiencing a failure to assume a position providing for a lean fuel mode of engine operation.

Abstract: a fuel system for mixture-compressing internal combustion engines controls the pressure differential of the extraction air required for proportioning the fuel. The system includes a fuel proportioning device and a vane pump for generating a carrier air stream for transporting the fuel into the suction tube of the internal combustion engine. A control valve constructed as a differential pressure valve influences the air pressure at the fuel outlet area and consequently the differential pressure for fuel proportioning. The throttle point is located in the carrier air channel upstream from the fuel proportioning area. A change in differential pressure adapts the mixture composition for various operating conditions.

Abstract: An internal combustion engine comprising a carburetor which has a main air bleed passage and a slow air bleed passage. An air-fuel ratio of the mixture fed into the cylinder of an engine is so controlled that it becomes equal to the stoichiometric air-fuel ratio by a single electromagnetic control valve arranged in the main air bleed passage and the slow air bleed passage. The control valve comprises a first reed valve arranged in the slow air bleed passage, a second reed valve arranged in the main air bleed passage, and an electromagnetic device simultaneously actuating the first reed valve and the second reed valve while maintaining the opening area of the first reed valve at an area which is larger than the opening area of the second reed valve.

Abstract: A vehicle has a combustion engine, ground-engaging drive wheels, an induction passage for supplying motive fluid to the engine, a fuel metering system communicating generally between a source of fuel and the induction passage, a valving arrangement in the fuel metering system effective to controllably alter the rate of metered fuel flow through the fuel metering system; an oscillator electrically connected to the valving arrangement intermittently energizes the valving arrangement, and a manually controlled adjustment selectively alters the operation of the oscillator to selectively vary the respective percentages of times that the valving arrangement is energized and de-energized by the oscillator.

Abstract: A vehicle has a combustion engine, ground-engaging drive wheels, a power transmission for conveying power from the engine to the wheels, an induction passage for supplying motive fluid to the engine, a source of fuel, a fuel metering system communicating generally between the source of fuel and the induction passage, a valving arrangement in the fuel metering system effective to controllably alter the rate of metered fuel flow through the fuel metering system, and a manually controlled adjustment operatively connected to the valving arrangement, the manually controlled adjustment being effective to selectively control the valving arrangement in order to thereby selectively alter the rate of metered fuel flow to the engine.

Abstract: A jet control type carburetor according to the present invention includes an intake pipe having an intake passage formed in an inner wall thereof, the intake passage allowing an intake air to flow therethrough; a venturi provided in the intake pipe, for controlling flow velocity and pressure of the intake air in the intake passage; a fuel nozzle opened into the intake passage and connected to a fuel supply source through a fuel passage for sucking the fuel within the intake passage from the fuel nozzle in order to introduce the mixture of air and fuel within the intake passage; a throttle valve provided downstream of the venturi, for controlling the flow rate of the mixture of intake air and fuel; a control fluid nozzle opened into the intake passage and connected to a fluid supply source through a control fluid passage for jetting the flow of the control fluid to the fuel spurted from the fuel nozzle to afford the kinetic energy of the control fluid to the fuel, and a throttle means provided upstream of the

Abstract: The pulse-width of the fuel injection signal is controlled, depending upon the running speed and the intake manifold pressure, and corrected by the transient correction factor, which is determined in accordance with the transient operating condition, and the A/F correction factor, which is determined the air-fuel ratio condition. The map used for obtaining the transient correction factor from the transient operating condition is corrected depending upon the converging state of the A/F correction factor by the learning control operation.

Abstract: An air-fuel ratio control system for an internal combustion engine having a two-barrel carburetor comprising a primary side having a main metering system and a slow speed system and a secondary side having a main metering system. Two on-off electro-magnetic valves are provided for correcting the air to be supplied to air bleeds of both the primary and secondary sides for correcting air-fuel ratio of the air-fuel mixture supplied by the carburetor.A first passage is provided for connecting the slow speed system of the primary side to one of the electromagnetic valves, a second passage is adapted to connect the main metering system of the secondary side to the one of the electromagnetic valves; and a third passage is provided connecting the main metering system of the primary side to the other electromagnetic valve.A change-over valve is provided for changing the connection between the electromagnetic valve and first and second passages.

Abstract: A method and apparatus for detecting the presence and quantity of fuel in a fuel/air mixture to the cylinders of a fuel injection engine is disclosed. A portion of the fuel/air mixture injected to the engine is diverted through a solid state sensor which, when included in a detection circuit, provides a resistance which is proportional to the amount of fuel in the mixture. The sensor reacts to the presence of the fuel vapors by providing a change in the voltage across the sensor.

Abstract: A constant depression carburettor has an auxiliary throttle member associated with a sensor which delivers a signal representative of the position of the auxiliary throttle member. A solenoid valve is actuated by pulses received from a control circuit which receives input signals from sensor. The solenoid valve meters the fuel delivered to the intake passage via a discharge orifice located at the throat of a venturi limited by a swelling of the intake passage and by the throttle.

Abstract: Method of controlling a control system for an air-fuel ratio of air-fuel mixture supplied to an internal combustion engine so that the proper air-fuel ratio is obtained over the whole operation range including a normal operation region and an accelerating operation mode independently of a decrease in oxygen contents at places of high altitudes. When the accelerating operation region is sensed, a proper power duty, corresponding to a negative pressure at that time, is read out from a data table stored in a read-only memory and added to a duty pulse signal which is then utilized for controlling a fuel supply actuator.

Abstract: In an internal combustion engine having at its intake section a two-barrel type carburetor including a primary fuel supply system having a primary main fuel supply line and a primary slow fuel supply line and a secondary fuel supply system having a secondary main fuel supply line and a secondary step fuel supply line, and at its exhaust section a three-way catalytic converter, there is provided an improved closed loop type air-fuel ratio control system which controls not only the amount of air fed to the primary main and slow fuel supply lines but also the amount of air fed to the secondary main and step fuel supply lines in accordance with the concentration of a selected component of the engine exhaust gas. A switching valve is associated with both the primary slow fuel supply line and the secondary main or step fuel supply line so as to alter the course of the air introduction into the primary slow fuel supply line or into the secondary main or step fuel supply line in accordance with the engine load.

Abstract: An electronically controlled carburetor for an internal combustion engine for a vehicle has a variable venturi for varying the venturi cross-section and concurrently varying the amount of air metered into the venturi in response to the engine demands an air flow sensor for sensing the displacement of the variable venturi and producing related electrical signals in response to changes in air flow through the venturi, a main fuel nozzle for discharging metered fuel into the venturi, a fuel flow sensor for sensing pressure differential of fuel across a main fuel jet communicating with the main fuel nozzle and for producing related electrical signals in response to changes in fuel flow through the main fuel jet, an air bleed controlling actuator for controlling the amount of air to be bled into the main fuel nozzle, and a control circuit responsive to the output signals from the air flow sensor and the fuel flow sensor for driving the air bleed controlling actuator.

Abstract: A fuel metering apparatus is shown as having a throttle body with an induction passage therethrough and a throttle valve for controlling flow through the induction passage, a fuel-air mixture discharge member is situated generally in the induction passage downstream of the throttle valve, an air passage communicates between a source of air and the fuel-air mixture discharge member, the air passage also includes a flow restrictor therein which provides for sonic flow therethrough, and a fuel metering valving assembly is effective for metering liquid fuel at a superatmospheric pressure and delivering such metered liquid fuel into the air passage upstream of the flow restrictor thereby causing the thusly metered liquid fuel and air to pass through the sonic flow restrictor before being discharged into the induction passage by the fuel-air mixture discharge member, the fuel-air mixture discharge member has a plurality of discharge ports spaced from each other and directed generally radially inwardly of the induct

Abstract: An internal combustion engine carburetor is disclosed which includes an induction passage provided therein with venturi means and controlled by throttle valve means, a fuel bowl connected through a main solenoid valve to a main fuel passage for discharging fuel through a main nozzle opening into the venturi means, a fuel pump connected through an auxiliary solenoid valve to an auxiliary fuel passage into which an air bleed opens for discharging fuel through a sonic nozzle opening into the induction passage downstream of the throttle valve means, and fast-idle mechanism for forcing the throttle valve means to open to a predetermined angle from its closed position. A control circuit is provided for providing a control signal corrected based on the density of atmospheric air, which corresponds to the rate of air flow through the induction passage for controlling the main and auxiliary solenoid valves. The control circuit is adapted to drive the fast-idle mechanism at low engine temperatures.

Abstract: The amount of fuel supplied to the engine is corrected in accordance with an air-fuel ratio correction coefficient. When the engine is in a predetermined first operating condition, the correction coefficient is calculated depending upon the detected concentration of a predetermined component in the exhaust gas, and thus the above correction is performed by closed-loop control. When the engine is not in the first operating condition, the correction coefficient is fixed, and thus the above correction is performed by open-loop control. An average value of the calculated correction coefficient is calculated only when the engine is in a predetermined second operating condition. An initial value of the air-fuel ratio correction coefficient when closed-loop control is resumed is determined to be the calculated average value.

Abstract: A system for detecting the operation of the throttle valve of an internal combustion engine for an emission control system for internal combustion engines. The emission control system has a three-way catalyst convertor, a detector, such as an oxygen sensor for detecting the concentration of oxygen in the exhaust gases, an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture and an electronic controller. The system comprises a transducer, such as a potentiometer and a pair of sample-and-hold circuits, in which each gate thereof is periodically operated by pulse trains for sampling and holding the output voltage of the transducer, which pulse trains have a 180 degrees phase difference with respect to each other. Both sample-and-hold circuits are connected to an operational amplifier type comparator through relay switches.

Abstract: In order to produce a transition mixture enrichment during acceleration of an internal combustion engine, a carburettor or other mixture generator 1 of the engine with a mixing chamber 2, a main throttle 4 and a choke valve 5, has the choke valve 5 operated by a quick-acting electric drive 6, for example a two-coil rotary setter, which is controlled by a microprocessor 8. The microprocessor is fed with signals which sense the opening of the main throttle 4 and preferably also other engine operating parameters such as temperature and speed. When the main throttle 4 is opened to accelerate the engine, the microprocessor 8 causes the electric drive 6 to close the choke valve 5 abruptly and temporarily. The extent of closure of the choke valve 5 is dependent upon the extent of the throttle opening and on the other operating parameters to give the required mixture enrichment. This arrangement avoids the necessity to provide an accelerator pump.

Abstract: An internal combustion engine includes an intake system, an exhaust system, and a mixture supply device which supplies primary fuel-air mixture into the intake system. An oxygen sensor assembly detects oxygen concentration at a certain point in the exhaust system and produces a first electrical signal which represents this concentration. A secondary air flow control circuit receives this first electrical signal and produces a second electrical signal according thereto. A secondary air supply system feeds secondary air into the exhaust system upstream of the aforementioned certain point at a flow rate controlled by the second electrical signal. A primary air/fuel ratio correction circuit receives either the first or the second electrical signal and based on it produces a primary mixture control electrical signal.

Abstract: 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.

Abstract: An open loop electronics circuit (1) for altitude compensation of a carburetor (C) installed on an internal combustion automobile engine (E). The carburetor has an associated solenoid (S) controlling auxiliary air bled into fuel circuits of the carburetor thereby to control the air-fuel ratio of the mixture produced by the carburetor. A bridge (7) continuously senses the density of air which varies as a function of altitude and generates an electrical signal Es the amplitude of which changes in response to changes in air density. A converter (13) is responsive to the electrical signal for generating a variable pulse width control signal Cs supplied to the solenoid. The converter (13) varys the pulse width of the control signal in response to amplitude changes in the electrical signal generated by the bridge circuit whereby the air-fuel ratio of the mixture produced by the carburetor is varied as a function of changes in air density.

Abstract: The operation of a motor vehicle is controlled by reading of a programmed memory to accelerate the vehicle along a predetermined optimum efficiency curve. The acceleration is independent of the position of the accelerator pedal, provided the pedal is neither in the idling position nor in the full throttle position. For these positions, the acceleration of the vehicle is not under the control of the programmed device.

Abstract: A low speed fuel supply system for a carburetor of an engine, with the system including an ascending fuel passage communicating with a fuel supply. A fuel-air passage is provided with an air bleed at an upper end, with the fuel-air passage opening, at the upper end thereof, into an induction passage of the carburetor upstream of a throttle valve mounted across the induction passage. A lower end of the fuel-air passage communicates with the induction passage in a vicinity of the throttle valve. A horizontally disposed fluid passage is provided for connecting both the upper ends of the fuel-air passage and the ascending fuel passage. The horizontally disposed fluid passage forms a valve seat, with a guide member being provided forming a valve body disposed in alignment with the valve seat. An air bleed introduces air into the upper portion of the ascending fuel passage directly toward the valve body.

Abstract: An air-fuel ratio control device for controlling the air-fuel ratio of a mixture to be supplied into an internal combustion engine. The device has a control circuit adapted to produce, in accordance with the offset of the output of an oxygen sensor in the exhaust system of the engine from a reference value corresponding to the desired air-fuel ratio, a control signal for making the air-fuel ratio coincide with the command air-fuel ratio. The device further has a mixture supplying means including means for adjusting the air-fuel ratio in accordance with the control signal. The air-fuel ratio adjusting means includes an actuator incorporating a step motor adapted to change the opening area of fuel passage or air bleed passage of a carburetor.

Abstract: A spark-ignition engine has self adaptive adjustment of the size of its fuel rations in dependence on misfires in the engine. A misfire is identified as an abnormal deficiency in energy conversion, this being detected by means of a mechanical energy discriminator which compares the quanta of energy derived from different combustion cycles. When a misfire in a particular cylinder is identified, the fuel rations to that particular cylinder are automatically increased. Overall increase of fuel rations is counteracted by gradually decreasing the fuel rations of cylinders when they are firing regularly and not producing deficient quanta of energy. In the preferred embodiment each cylinder has its own fuel injector valve. The valve is normally closed, being opened for a short interval of time during each cylinder cycle. The size of a fuel ration is regulated by varying the duration of opening of the valve.

Abstract: An electronically controlled fuel supply apparatus for controlling a fuel flow required by an internal combustion engine in dependence on operation parameters of the engine. An electronic control device is disposed within an engine chamber, and fuel is forcibly circulated in the vicinity of the electronic control device from a fuel tank to thereby cool the electronic control device.

Abstract: An air-fuel ratio controller for carburetors in which an auxiliary fuel system opening to the downstream side of a throttle valve of a carburetor is provided separately from the main and slow fuel systems of the carburetor. The air-fuel ratio of the mixture flowing through this auxiliary fuel system is controlled by a solenoid valve adapted to operate in accordance with either one or both of a parameter representing the warming up after cold start and a parameter representing deceleration of the engine.

Abstract: An air-fuel ratio control system for an internal combustion engine comprises an intake passage, an air-fuel mixture supply means, electromagnetic means for correcting the air-fuel ratio of the air-fuel mixture supplied by the air-fuel mixture supply means, an exhaust passage, and a feedback control system. The error signal in the feedback control system is oscillated by a dither signal having a periodical pattern for oscillating the air-fuel ratio of the mixture. The dither signal comprises a plurality of positive excursions and negative excursions, and at least one of the positive excursions is lower than the other and at least one of the negative excursions is lower than the other. The dither signal is applied to the electromagnetic means for oscillating the air-fuel ratio of the mixture.A detector senses the concentration of exhaust gases.

Abstract: An electronic control system for controlling the air-fuel ratio for an internal combustion engine comprising an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by an air-fuel mixture supply device, a comparing circuit for comparing the output signal of a detector with a reference value, an integration circuit connected to the comparing circuit, a pulse generator, and a comparator for producing pulses for driving the on-off type electromagnetic valve from output signals of the integration circuit and of the pulse generator for controlling the air-fuel ratio to a value substantially equal to the stoichiometric air-fuel ratio. A first converter converts the operation of the throttle valve to an electric quantity output, a second converter converts the prevailing ambient atmospheric pressure to another electric quantity output.

Abstract: A feedback control system using an oxygen-sensitive air/fuel ratio sensor which is disposed in induction passage for an IC engine downstream of a fuel supply device with the provision of an ignition means to burn a fractional portion of an air-fuel mixture in the induction passage such that the oxygen-sensitive sensor is exposed to a resultant combustion gas. The sensor is of the concentration cell type having a layer of solid electrolyte such as zirconia provided with two electrode layers, and constant DC current is supplied to this sensor to cause migration of oxygen ions through the solid electrolyte layer, whereby this sensor exhibits a slope output characteristic and can detect air/fuel ratios either above or below a stoichiometric ratio or exhibits an on-off characteristic and can detect the stoichiometric ratio depending on the intensity and flow direction of the current.

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 jet control type carburetor according to the present invention includes an intake pipe having an intake passage formed in an inner wall thereof, the intake passage allowing an intake air to flow therethrough; a venturi provided in the intake pipe, for controlling flow velocity and pressure of the intake air in the intake passage; a fuel nozzle opened into the intake passage and connected to a fuel supply source through a fuel passage for sucking the fuel within the intake passage from the fuel nozzle in order to introduce the mixture of air and fuel within the intake passage; a throttle valve provided downstream of the venturi, for controlling the flow rate of the mixture of intake air and fuel; a control air nozzle opened into the intake passage and connected to an air supply source through a control air passage for jetting the flow of the control air to the fuel spurted from the fuel nozzle to afford the kinetic energy of the control air to the fuel; and a throttle means provided upstream of the control a

Abstract: A fuel metering apparatus is shown as having a throttle body with induction passage means therethrough and a throttle valve for controlling flow through the induction passage means, fuel under superatmospheric pressure is metered and such metered fuel is supplied to a fuel discharge nozzle situated within the induction passage means downstream of the throttle valve; a first air flow is supplied to the metered fuel upstream of the fuel discharge nozzle as to cause the metered fuel to at least start to undergo atomization even before being discharged at the discharge nozzle; a second air flow is also supplied to the fuel discharge nozzle as to at idle engine speed flow sonically therethrough, and additional throttling valving means are provided for controlling the air flow to the fuel discharge nozzle.

Abstract: During operation of an internal combustion engine at low temperatures, the carburetor choke is closed to the extent necessary to provide the fuel which will maintain the mean effective pressure of combustion equal to the mean effective pressure occurring during operation at normal temperatures. The torque produced during low temperature engine operation is thus maintained equal to the torque produced during operation at normal temperatures.

Abstract: A feedback type variable venturi carburetor in which the negative pressure regulated by the variable venturi at a constant level is supplied to a solenoid valve which is opened and closed at a frequency of 5-30 Hz and whose open-close time ratio is controlled in accordance with the signal from exhaust gas sensor to control the vacuum pressure applied to a diaphragm chamber of an air-bleed flow control means thereby controlling the air-fuel ratio of the mixture at an optimum level. This invention obviates the use of a regulator for regulating the negative pressure from the intake manifold and precludes the drawbacks experienced with conventional carburetors, such as the slow response in the feedback control caused when the main fuel system and the idling system of the conventional carburetor are switched over, and the unstable supply of fuel when the fuel begins to be delivered from the main fuel system.

Abstract: A system for controlling in a feedback control mode the air-fuel ratio of an air-fuel mixture to be supplied to an internal combustion engine in response to the deviation from a reference value, of an output of an exhaust sensor for sensing the concentration of a component of engine exhaust gas. The reference value is varied even during stopping of the feedback control due to an lowered engine temperature, thereby preventing an erroneous control. Additionally, the reference value and the value of a current flow to the exhaust sensor are varied immediately when the feedback control is stopped due to lowering in the engine temperature, thereby quickening the initiation of the feedback control.

Abstract: A control system for an internal combustion engine comprises a transducer for issuing a signal representative of combustion pressure in a combustion chamber, a unit consisting of a bandpass filter and a wave-form shaping circuit for issuing a signal representative of existing combustion timing of the combustion chamber by processing the signal from the transducer for detection of rapid increase of the combustion pressure; a reference timing circuit for issuing a signal representative of a predetermined reference combustion timing of the combustion chamber in accordance with operation modes of the engine, a comparator circuit for issuing a signal representative of a difference between the signal from the unit and the signal from the reference timing circuit, and a unit consisting of a discriminating circuit and an actuator driving circuit for controlling the ignition timing, the air-fuel ratio of air-fuel mixture and the amount of exhaust gas recirculated into the intake system of the engine, by processing the

Abstract: An engine comprises a combustion chamber and a throttle movable between a low speed position for operating the engine at a low speed and a range of positions spaced from the low speed position for operating the engine within a range of speeds above the low speed. An enrichment fuel delivery system communicates with the combustion chamber and a source of fuel and is operative for introducing fuel from the fuel source into the combustion chamber. The enrichment fuel delivery system includes a control mechanism which is operatively connected with the throttle. The control mechanism operates the enrichment fuel delivery system in response to advancement of the throttle from its low speed position to introduce fuel into the combustion chamber for a predetermined time interval.

Abstract: A fuel metering apparatus is shown as having a throttle body with induction passage means therethrough and a throttle valve for controlling flow through the induction passage means, fuel under superatmospheric pressure is supplied to a fuel discharge nozzle situated within the induction passage means downstream of the throttle valve, air is also supplied to the fuel discharge nozzle as to at idle engine speed flow sonically therethrough, and additional throttling valving means are provided for controlling the air flow to the fuel discharge nozzle.