Abstract: A variable intake system may include an air duct that guides intake air into an engine and a variable valve having a variable opening degree, to adjust an amount of the intake air, wherein the air duct includes a first inlet and a second inlet that may be opened to an outside, wherein the air duct has a first flow path having one end connected with the first inlet and a second flow path having one end connected with the second inlet, wherein the second flow path shares a part of the first flow path, wherein another end of the first flow path and another end of the second flow path share a same outlet, and wherein a length of the second flow path may be longer than a length of the first flow path.

Abstract: A low-fuel consumption and low-pollution combustion system supplies an engine with a mixture, in which oxygen contained in air is separated from nitrogen through a PSA (pressure swing adsorption) whereby oxygen having purity above 95% and a fuel mixture is fed into and burned in the combustion chamber obtaining a desired engine output with low-fuel consumption. Nitrogen is previously removed so that nitride oxide can be minimized during combustion procedure and CO and toxic gas derived from incomplete combustion can be minimized. The system obtains high engine output and low-fuel consumption by reducing toxic gas derived from incomplete combustion. The system includes an oxygen separator for separating oxygen from nitrogen by introducing external air into adsorption towers with predetermined pressure while storing the oxygen separated from the nitrogen in an oxygen storage tank and exhausting the nitrogen.

Abstract: An integral vacuum generator system for an internal combustion engine includes a throttle body and intake manifold defining a bypass passage which is connected with a vacuum manifold by both a venturi and a direct vacuum supply passage. Vacuum flow through the venturi and the direct vacuum supply passage are controlled by check valves.

Abstract: In accordance with embodiments of the present invention, a system is provided comprising an oxygen-enrichment reverse osmosis unit coupled to an intake of an internal combustion engine. Ambient air is supplied to the reverse osmosis unit via an ambient-air inlet and oxygen-enriched air is output via an oxygen-enriched outlet. The oxygen-enriched outlet is coupled to the intake of a combustion chamber of the internal combustion engine. Providing oxygen-enriched air relative to ambient air to the internal combustion engine allows for reducing the size of the combustion chamber while providing equivalent power, resulting in a smaller engine. At the same time, the smaller engine saves consumption of fuel due to lower engine weight and more complete combustion. The smaller engine is also cheaper to build because it requires less material for fabrication.

Abstract: A torsion-enhancing apparatus has a mounting bracket, a vacuum bracket and two air filters. The mounting bracket has a threaded hole, a first connecting tube and two ventilating holes. The threaded hole is formed in the front end and the first connecting tube is connected to the rear end of the mounting bracket. The vacuum bracket is connected to the mounting bracket, and has a rear cap, a front cap, a diaphragm, a spring and a pressing disk. The rear cap is connected to the front end of the mounting bracket. The front cap is connected to the rear cap and has a third connecting tube, an adjusting bolt and a sealing ring. The diaphragm is mounted between the caps. The spring is mounted in the caps between the adjusting bolt and the diaphragm. The air filters are connected to the second connecting tubes of the mounting bracket.

Abstract: An auxiliary valve assembly for improving the aspiration of an internal combustion engine. The auxiliary valve can be thread-mounted to a gas-air intake chamber. A spring-biased ball that seals an air inlet opens under sufficient vacuum pressure. Filtered air then passes through the auxiliary valve assembly into the gas-air intake chamber. The incoming air oxygenates the gas and thus improves fuel economy, extends value and spark plug life, reduces pollution, and improves oil viscosity.

Abstract: A Vacuum Relief Assembly for I.C. Engine Intakes is disclosed. Also disclosed is a device that permits outside air into the intake tract of an internal combustion engine in the event of an excessively high vacuum condition within the intake tract. Furthermore, the device is constructed from durable materials and resists the excessive temperatures found in the engine compartment of a vehicle. Still further, the device is made from two half-cylindrical sections that mate to one another around the intake tract to form a cylindrical attachment. The method of installation enables the device to be installable onto the intake tract in situ, and without the need to cut out a section of the tract.

Abstract: A vacuum generator is provided wherein the intake vacuum of a combustion engine is led to a negative pressure device such as a vacuum booster of a brake booster device through a check valve. An idling air passage is connected to a suction pipe of the combustion engine to bypass a throttle valve arranged in the suction pipe. An ejector is arranged in the idling air passage at the downstream of an idle speed control valve in serial relation to the same, and the intake for idling is performed through the ejector. As the intake air flow passing through the idling air passage increases, the intake negative pressure which is generated at a vacuum takeout port of the ejector is further increased in absolute value, whereby the negative pressure device has a negative pressure which is further increased in absolute value.

Abstract: Please substitute the new Abstract of the Disclosure submitted herewith on a separate page for the original Abstract presently in the application.

Abstract: An air cleaner intake door is provided. An air cleaner with at least one sidewall and an opening defined in the sidewall has a door mounted over the opening. The door is rotationally movable between an open and a closed position and a cam extends from the door. A spring is in contact with the door for biasing the door towards a closed position.

Abstract: A pressure releasing valve capable of reserving air pressure is formed with a pressure reserving chamber to retain a proper amount of air pressure in the pressure releasing valve when the engine is changing from an accelerating and increasing pressure condition to a condition of running idly and releasing pressure, so that when the engine accelerates and increases pressure again, air of the condenser can be continually supplied for the engine to let it run comparatively smoothly in accelerating, not only economizing energy but ensuring safety as well.

Abstract: An automatic bleed valve is disclosed, suitable for attachment to the inlet manifold of an internal combustion engine in order to provide an effective embodiment of the "air bleed" principle. Small amounts of inlet air are allowed into the inlet manifold at periods of high vacuum (low pressure) present during deceleration. The valve closure (38) is biassed by a biassing means (36), e.g. a compressing spring, which acts on the face of the closure disposed away from the seat (22). Other aspects provide for a valve seat which is adjustable in position relative to the closure, a closure and seat of different plastics materials, and a closure with a conical aspect, preferably paired with a seat with a complementary contact portion.

Abstract: An air intake device has a base seat, a hollow main body disposed on the base seat, and a hollow cover seat disposed on the hollow main body. An intake guide pipe is connected to the connection pipe. A plurality of L-shaped plates are disposed in the hollow cover seat. An upper magnet is disposed in the hollow cover seat. A lower magnet is disposed in the hollow main body. The lower magnet has a taper lower portion. The hollow main body has an upper interior, an inner thread, a lower interior, a lower groove, and an upper groove. A hollow adjustment screw is inserted in the hollow main body. The hollow adjustment screw has a center hole and an annular recess receiving a seal ring. The base seat receives an air cleaner.

Abstract: An air inlet auxiliary device provides additional air to an inlet manifold of a vehicle. The auxiliary device includes a main body, a filter assembly mounted to a first end of the main body, a control seat mounted to a second end of the main body and in fluid communication with the inlet manifold, and first and second cylindrical members mounted in the main body. Air passages are defined in the first and second cylindrical members. When the engine of the vehicle is idling or runs under a speed slower than a pre-determined value, more additional air is supplied to the air manifold, and when the engine is running under a speed faster than the pre-determined value, only a small additional amount of air is supplied to the inlet manifold.

Abstract: An air assist device comprising a plurality of air intake ports formed in the inner wall of an intake duct around a throttle valve. The assist air is taken in from the air intake ports. The amount of opening of the air intake ports is controlled by the outer peripheral end face of the throttle valve. The cross-sectional shapes of the air intake ports are made easily formed circular cross-sectional shapes.

Abstract: A burning effect booster for an engine includes a body, a filter device, adjusting screws, and vacuum valve units. The vacuum valves units respectively have two nozzles to be connected with the intake manifold of an engine. The adjusting screws are adjusted depending on air intake volume, compression rate and the number of throttles of the engine, controlling filtered clean air to be sucked through the vacuum valves units into the intake manifold by means of the pistons moved in cylindrical threaded members in the vacuum valve units according to vacuity in the intake manifold. Then gas in the engine can burn completely to reduce waste gas exhausted.

Abstract: A gasoline engine booster which includes a casing having a first port connected to the atmosphere, a second port connected to the intake manifold, a first air passage of smaller diameter and a second air passage of bigger diameter connected in series between the first port and the second port, an adjusting device longitudinally movably fastened to the inside of the second air passage to hold a spring, a steel ball supported on the spring and forced by it to stop the connection between the first air passage and the second air passage, and a tightening up screw threaded into a screw hole on the casing to hold down the adjusting device, whereby when the pressure in the intake manifold drops below a predetermined value, outside air is induced into the first air passage to force the steel ball away from the first air passage, so that outside air flows through the second air passage into the intake manifold of the gasoline engine to mix with fuel oil for complete combustion.

Abstract: A fuel consumption optimizer and exhaust emissions reducer for an internal combustion engine including an air-vacuum liquid compensation device has a device for supplying a first stream of air at high speed and a second stream of air at high volume through respective channels into a booster container and a device for passing the first stream of air and the second stream of air through a plurality of openings in the respective channels into a body of liquid in the booster container. A method is described for optimizing fuel consumption and reducing exhaust emissions in an internal combustion engine.

Abstract: A suction and exhaust connection device for a multi-cylinder internal combustion engine is disclosed. The device converts the exhaust pressure of a cylinder in the exhaust stroke into suction pressure for another cylinder in the suction stroke which is synchronized with the exhaust stroke of the one cylinder performing the exhaust stroke, thereby increasing suction speed and amount. The device also temporarily keeps the suction gas therein just after the suction stroke of the cylinder performing the suction stroke and introduces the suction gas into the other cylinder during the next suction stroke, thus restricting suction interference. The device temporarily keeps a part of the exhaust gas therein during the exhaust stroke of the cylinder performing the exhaust stroke and expels the exhaust gas to the outside after a predetermined time, thus restricting exhaust interference and allowing continuous exhaust of the gas.

Abstract: A fuel injection system for an internal combustion engine having an air supply passage for supplying air to a point close to the fuel injection hole of a fuel injector to realize good atomization of the injected fuel. The system comprises an air supply passage, a control valve arranged therein, an opening passage for opening the air supply passage downstream of said control valve into the atmosphere, and a normally closed valve arranged therein. The normally closed valve is opened when an increased amount of pressure for a predetermined period in the intake passage downstream of the throttle valve becomes larger than a predetermined value. Accordingly, the pressure in the air supply passage does not become lower than that in the intake passage downstream of the throttle valve so that a back-flow of intake air can be prevented.

Abstract: An intake manifold for use with a combustion engine is disclosed. The intake manifold comprises a dimensionally stable induction pipe body having at least one first flow-through opening and at least one first adjusting element arranged in the first flow-through opening to vary the available cross-sectional area of the passage. This adjusting element takes the form of a throttle valve, which is rotatably supported in the induction pipe body and which is capable of being forced to engage sealingly with the boundary wall of the first flow-through opening. In the area of the throttle valve, the induction pipe body has at least one second flow-through opening, which is allocated as a by-pass so as to be adjacent to the first flow-through opening, said second flow-through opening being capable of being sealed by at least one second adjusting element, which is comprised of a one-way valve that is only able to be forced into an open position in the direction of the attached combustion engine.

Abstract: The present invention involves an air regulation system for an internal combustion engine. The system comprises an air intake manifold, in turn presenting a main conduit with a throttle valve, and a bypass conduit with a regulating valve. An inlet and outlet are defined along the main conduit respectively upstream and downstream from the throttle valve. The system includes a device for controlling the regulating valve and sensors for detecting the speed and air intake of the engine. A processor determines the regulating valve control signal on the basis of engine speed. The processor then calculates the theoretical position of the regulating valve on the basis of engine speed and load. The processor calculates the estimated post-control position of the regulating valve on the basis of the readings of the sensors and compares the theoretical and estimated positions to generate an error signal. Finally, the processor varies the regulating valve control signal on the basis of the error signal.

Abstract: A supplemental emission control device for a gasoline engine utilizes the vacuum suction of the venturi of the carburetor or the air intake manifold to draw ambient air through a filter sponge and a piston control chamber into the combustion chamber of a gasoline engine to mix with the fuel therein to form a uniform fuel mixture for a complete and efficient combustion. A regulating screw is provided to regulate the flow rate of the ambient air into the combustion chamber.

Abstract: Disclosed herein is an emission control device for use with a carburetor or fuel injection engine. The device is comprised of a body member of predetermined thickness and may define therein at least one through opening. The through opening communicates with the fuel opening in the carburetor or the fuel injection body. The device also has an air passageway largely defined in its surface. The air passageway communicates with the through opening and lies generally under the fuel passageways of the carburetor or injection body so that air passed through the passageway passes into the through opening and under the fuel passageways.

Abstract: An air induction control device for an internal combustion engine comprises means defining a communication passageway for communicating between air at atmospheric pressure and the air in the downstream passageway from a throttle valve. A valve member is disposed in the communication passageway and is moveable toward the downstream direction thereof to open the communication passageway in response to an atmospheric pressure greater than pressure in the downstream passageway. A valve biasing means is disposed to apply force to and bias the valve member in the upstream direction to close the communication passageway in response to the pressure differential between atmospheric pressure and the air pressure int he downstream passageway. A flow restriction element positioned downstream of the valve member comprises calibrated openings defining a primary chamber and secondary chamber, wherein the volumetric proportion of the primary chamber: second chamber: calibrated openings is about 50-70: 25-35: 0.8-1.2.

Abstract: An air induction control device for an internal combustion engine comprises means defining a communication passageway for communicating between air at atmospheric pressure and the air in the downstream passageway from a throttle valve. A valve member is disposed in the communciation passageway and is moveable toward the downstream direction thereof to open the communication passageway in response to an atmospheric pressure greater than pressure in the downstream passageway. A valve biasing means is disposed to apply force to and bias the valve member in the upstream direction to close the communication passageway in response to the pressure differential between atmospheric pressure and the air pressure in the downstream passageway. A flow restriction element positioned downstream of the valve member comprises calibrated openings defining a primary chamber and secondary chamber, wherein the volumetric proportion of the primary chamber:second chamber:calibrated openings is about 50-70:25-35:0.0-1.2.

Abstract: Disclosed herein is an emission control device for use with a carburetor having a base and at least one fuel opening defined in its base. The device is comprised of a body member of predetermined thickness and defining therein at least one through opening. The through opening communicates with the fuel opening in the carburetor. The device also has an air passageway largely defined in its surface. The air passageway communicates with the through opening. The passageway lies generally adjacent the carburetor and the fuel opening so that air passed through the passageway passes into the through opening and under the fuel opening.

Abstract: A cold start air control device for an internal combustion engine of the type having an air delivery system in which the delivery of air to a vacuum generating manifold is controlled by a throttle valve and a by-pass valve and parallel with the throttle valve includes a casing that defines a passageway in parallel with the throttle valve and the by-pass valve and which has a cross-sectional area greater than that of the by-pass valve so as to offer a less restricted air flow path than that offered by the by-pass valve. The passageway provides communication between the manifold and atmosphere and a valve is disposed within the passageway for opening and closing the passageway in response to the vacuum level generated by the manifold.

Abstract: The proposed feed device comprises non-return valve means, preferably of flap type, which are able to open and close the small ducts provided for feeding the individual cylinders of an internal combustion engine when the throttle valves are in their maximum closure position.

Abstract: An apparatus for supplying additional air into the intake port of an internal combustion engine is described. The apparatus includes an additional air discharge means protruding into the intake port of the internal combustion engine and formed as nozzle tube. The nozzle tube is disposed at the combustion chamber end of the intake port directly adjacent to the inlet valve. Furthermore, the apparatus comprises an additional air flow rate controller and an additional air supply line between the nozzle tube and the flow rate controller. A vacuum line for the detection of vacuum and for the application of vacuum to the controller for the operation thereof leads from the intake port to the flow rate controller.

Abstract: An assembly is provided for supplying a supplemental source of ambient air into the air intake manifold of a two-cycle internal combustion engine during start-up and abnormally low idle modes during which typically only minimal air would otherwise be available. Upon increase of engine speed, the supplemental ambient air flow is stopped. In one embodiment, a flow path is provided between the crankcase of the engine in order that puddled fuel will be bled from this location and to the location of the supplemental air inlet in order to thereby recycle and burn the puddled fuel during high speed operation of the engine.

Abstract: An internal combustion engine has an intake gas conduit; an output setting member disposed in the intake gas conduit and arranged for controlling therein the flow of intake gas; an exhaust gas conduit; a throttle member disposed in the intake gas conduit upstream of the output setting member; a bypass conduit having an inlet end coupled to the intake gas conduit upstream of the throttle member and an outlet end coupled to the intake gas conduit downstream of the throttle member; an exhaust gas feedback conduit having an inlet end coupled to the exhaust gas conduit and an outlet end coupled to the bypass conduit; and a control arrangement for setting positions of the throttle member as a function of an operational parameter of the internal combustion engine for directing a quantity of intake air into the bypass conduit as a function of the operational parameter.

Abstract: An internal combustion engine is provided with a biased by-pass throttle valve that trims the flow of supplementary combustion air for mixing with basic combustion air and fuel induced in carburetor venturi. The by-pass throttle valve is controlled by an electrical stepmotor that is regulated by a pre-programmed microprocessor in response to sensed engine speed and engine manifold pressure conditions to thereby improve engine operating efficiency and reduce noxious emissions without utilizing catalytic converter equipment.

Abstract: An air and fuel mixing, modulating and supply means for a spark ignition internal combustion engine includes an air inlet manifold in effective connection with air and fuel metering means including a throttle. Two separate passages are provided which passages include holes in the inlet manifold. Each passage is controlled by a respective valve. Control means open or close the valves depending on engine condition. The first larger passage is effective to reduce engine vacuum when the engine speed is greater than a 1,000 rpm and the throttle is closed. The second smaller passage is effective to allow a small amount of additional air into the inlet manifold when the throttle is open and the engine speed is above 1,500 rpm.

Abstract: An air metering valve or supplemental air valve connectable in the PCV system of an internal combustion engine having a shiftable valving member which regulates the quantity of supplemental air introduced into the PCV return. The valve spool is spring biased to the open position by a calibration spring. Pressure chambers are formed on opposite sides of the actuating pistona nd connectable to engine vacuum sources. As the degree of vacuum varies in the vacum sources, the valve spool shifts between an open and closed position. The valve may also be used to provide supplemental ambient combustion air under vacuum control independent of the PCV system. In another embodiment of the invention, the major valve components such as the valve body and shiftable valving member are fabricated from suitable plastic materials.

Abstract: A cold-engine operation detector is provided for producing a cold-engine signal when engine temperature is lower than a predetermined temperature, and an idle engine speed detector is provided. A dead zone for input of engine speed with respect to desired engine speed in accordance with engine temperature is stored in a memory. Width of the dead zone is provided to increase with decrease of engine temperature. A range of the dead zone in accordance with engine temperature is derived from the memory. When actual engine speed is out of a derived range of the dead zone, an actuator provided in an idle speed control system is operated for controlling the actual engine speed to the desired engine speed.

Abstract: Automotive engine idle speed control device meters the flow rate of air supplied to the engine bypassing an intake pipe thereof during engine idle operation to thereby control the engine idle speed. An actuating vacuum is produced in accordance with an electrical signal and acts on a diaphragm fixed to a valve movable with the diaphragm to meter the bypass air flow. To cancel any external force acting on the valve, adjusting means is provided to control the vacuum on the diaphragm independently of the electrical signal to displace the diaphragm in a direction opposite to the direction of action of the external force on the valve.

Abstract: A suction system to an inlet valve of a reciprocating piston internal combustion engine consists of a suction line adapted to be closed by a closure valve and of a by-pass line by-passing the closure valve. A check valve is inserted into the by-pass line which is formed by slots in the suction line and spring lamellae covering the same from the outside. In order to reduce throttle losses and to permit a dynamic charging effect to become effective, the closure valve is fully opened at rotational speeds above 3,500 rpm.

Abstract: An air intake side secondary air supply system for an internal combustion engine is provided with a linear type solenoid valve disposed in an air intake side secondary air supply passage leading to an intake air passage, downstream from the throttle valve. The opening degree of the linear type solenoid valve is controlled continuously by a drive current supplied to the solenoid. The magnitude of the drive current of the solenoid is determined by providing a base value of current which is responsive to a plurality of engine parameters that represent the engine load, and by correcting the base value in accordance with a result of the sensing of concentration of an exhaust gas component.

Abstract: In an intake system having a bypass passage for introducing auxiliary air to the engine, a base amount of auxiliary air is first determined according to the engine operating condition. A target idling speed is calculated according to the engine temperature and the engine load and the target idling speed is compared with the actual engine speed. The base amount of auxiliary air is corrected according to the difference between the target idling speed and the actual engine speed, thereby obtaining a final target amount of auxiliary air. The control amount of the control valve is determined according to the final target amount of auxiliary air referring the final target amount of auxiliary air to the output characteristics of the control valve. Then the control valve is driven on the basis of the control amount.

Abstract: An air intake side secondary air supply system for an internal combustion engine having an air intake system using a carburetor and an air intake side secondary air supply passage leading to the downstream of the carburetor, includes an oxygen concentration sensor producing an output signal whose level is substantially proportional to an oxygen concentration of the exhaust gas. A control means for controlling a duty ratio of opening and closing of an open/close valve disposed in the air intake side secondary air supply passage in accordance with a result of comparison between the level of the output signal of the oxygen concentration sensor and a level corresponding to a target air-fuel ratio. The target air-fuel ratio is up-dated in response to at least two parameters indicative of the engine operation.

Abstract: An air metering valve or supplemental air valve connectable in the PCV system of an internal combustion engine having a shiftable valving member which regulates the quantity of supplemental air introduced into the PCV return. The valve spool is spring biased to the open position by a calibration spring. Pressure chambers are formed on opposite side of the actuating piston and connectable to engine vacuum sources. As the degree of vacuum varies in the vacuum sources, the valve spool shifts between an open and closed position. The valve may also be used to provide supplemental ambient combustion air under vacuum control independent of the PCV system.

Abstract: A vacuum controller serving as a fuel saver includes a suction chamber communicated with a vacuum port of an engine carburetor and a plunger valve reciprocatively moved as actuated by the suction pressure in the suction chamber to control the air flow through a by-pass secondary air tube from an air filter towards a fuel inlet manifold for the complete combustion of fuel and for saving energy purpose.

Abstract: A primary passage and a secondary passage in a parallel relation to each other are disposed between an air cleaner and a branch passage collecting portion of an intake manifold. The primary passage is smaller in diameter than the secondary passage and has at the downstream end thereof a laval nozzle through which air flows at the speed of sound even under low-speed low-load engine operating conditions. The laval nozzle is connected to a carburetion chamber which is elongated straightly in the direction downstream of the laval nozzle. A fuel injection valve is disposed in the primary passage at a place upstream of the laval nozzle. A pressure control valve is adapted so that a vacuum higher than a predetermined value is developed in the carburetion chamber at any time. A primary throttle valve and a secondary throttle valve are interconnected so that the secondary throttle valve is held closed unless the primary throttle valve is fully open.

Abstract: An air intake side secondary air supply system for an internal combustion engine having an air intake side secondary air supply passage and an O.sub.2 sensor controls a duty ratio of opening and closing of an open/close valve disposed in the air intake side secondary air supply passage in accordance with a detected air-fuel ratio of mixture by means of an output signal of the O.sub.2 sensor. The system sets a base valve open period of the open/close valve every predetermined period and decreases the base valve open period by a first predetermined correction amount when the detected air-fuel ratio is leaner than a target air-fuel ratio, and increases the base valve open period by a second predetermined correction amount when the detected air-fuel ratio is richer than the target air-fuel ratio.

Abstract: Air intake side secondary air supply system for an internal combustion engine includes first and second secondary air supply passages leading to an intake manifold in which an open/close valve and an air control valve are respectively provided for a proportional control and an integral control of secondary air. In order to improve a driveability of the engine during a transition period from a feedback control mode to an open loop control mode, pressure control device for controlling a supply of first and second control pressures respectively for opening and closing the air control valve is constructed to rapidly supply the second control pressure when a state of engine operation in which the feedback control mode is to be stopped is detected.

Abstract: An adaptor flange for fitting under the mounting flange of a carburetor of an internal combustion engine and formed with a venturi type flow passage having perforated induction tube spanning thereacross for sensing the magnitude of the partial vacuum in such passage. A controller housing is connected on one end with an air filter and is formed with an induction throat leading to a control chamber. Disposed in the induction throat is a nozzle which is, in turn, connected with the carburetor float chamber. Mounted in the control chamber are first and second pressure responsive valves. Such valves are connected through air/fuel vapor lines to the induction tubes and are responsive to predetermined engine conditions, as sensed in said flow passage, to cooperate therewith in selectively varying the flow rate through said induction throat to correspondingly vary the mixture to the intake manifold.

Abstract: The so called air intake side secondary air supply system for an internal combustion engine having a choke valve in an intake air passage supplies an air intake side secondary air into the intake air passage so that the air-fuel ratio is feedback controlled. During a period of cold operation of the engine in which the choke valve is actuated to close the intake air passage, the supply of the air intake side secondary air is stopped to enrich the air-fuel ratio upon detection of a no-load operating condition of the engine such as in the case where clutch is disengaged or in the case where the shift position of the transmission is the neutral position or the parking position.

Abstract: An air valve for an internal combustion engine, said air valve comprising a valve body (10,19), a passage (27) in said body, valve means adapted to normally close said passage (27) to prevent egress therethrough of spent combustion products from said engine and to open on creation of a pressure drop within the engine to permit air to flow through the passage (27) into the engine. The valve means comprises a flexible valve element (18) engageable with a valve seat (26) associated with said passage (27), and means (17,22) for tensioning said flexible valve element (18) to assist effective operation of the valve element (18).

Abstract: A flow control system (10) responsive to fluid pressure comprising means (12, 20) for varying the magnitude of said pressure within a plurality of different pressure ranges; a plurality of pressure responsive valves (30, 32) communicated with said pressure means, each valve having at least two operative conditions; means (40, 42, 44, 46, 52, 54, 56, 58) for sequentially changing the operative condition of a particular one of said plurality of pressure responsive valves in response to changes in the magnitude of pressure communicated thereto.