Abstract: A fuel supply apparatus for an internal combustion engine comprises an air valve disposed in an intake air conduit upstream of a throttle valve and caused to rotate in accordance with the quantity of intake air through the intake conduit, a fuel supply source for supplying fuel under a substantially constant pressure through a fuel feed conduit to a fuel discharge port opened to the intake conduit, and a fuel metering device including a variable slit provided in the fuel feed conduit and interlocked with the air valve to be controlled such that the flow area of the variable slit may be proportional to the quantity of intake air and a fuel differential device for maintaining pressure difference across the variable slit at a predetermined value.

Abstract: An air-fuel ratio controlling system for a fuel-injection type internal combustion engine has an air valve disposed in an air intake duct upstream of a throttle valve and a fuel-metering variable orifice disposed in a fuel circuit. The air valve and the fuel-metering variable orifice are operatively associated with each other and controlled normally to maintain the air-fuel ratio at a substantially constant value. Pressurized fuel is used as a working fluid to operate the air valve. O.sub.2 sensor detects the oxygen content of exhaust gases to actuate a valve which varies the pressure of the working fluid to change the degree of opening of the air valve whereby the air-fuel ratio is adjusted in accordance with the output of the O.sub.2 sensor.

Abstract: In a carburetor, a heating device comprises a honeycomb heater element disposed within at least one of fuel and air passages of the carburetor to heat the fuel and/or air passing therethrough, the honeycomb heater element being made of a ceramic composition to have a positive temperature coefficient of resistance and being connected at the opposite ends thereof with an electric power source across an ignition switch of the engine, whereby the liquid fuel and/or air is heated by the heating device when the temperature of the liquid fuel or the air is lower than a critical temperature defined by the ceramic composition of the heater element.

Abstract: An internal combustion engine is provided with an EGR system and a system for catalytic coversion of a rich air-fuel mixture into a reformed combustible gaseous mixture rich with free hydrogen. During a low or medium engine load engine operation, the engine is operated solely by an air-gasoline mixture and with an exhaust gas recirculation at a rate not higher than a predetermined first EGR rate. During a high engine load engine operation, the reformed combustible gaseous mixture is added to the air-gasoline mixture supply and simultaneously the exhaust gas recirculation is increased to a rate higher than the predetermined first EGR rate to increase the engine output, improve the engine drivability and improve the consumption of the reformed combustible gaseous mixture. The intake manifold vacuum is electrically detected to determine the load on the engine and to control valves associated with the EGR system and reformed gas supply system.

Abstract: Disclosed is an air-fuel ratio controlling device of an internal combustion engine having on its exhaust system a three way catalytic converter. The O.sub.2 sensor is disposed in the exhaust system for providing a rich or a lean signal indicating that the total air-fuel ratio is on the rich side or on the lean side of the stoichiometric air-fuel ratio, respectively. A supplementary fuel feed control device having a nozzle flapper mechanism therein is provided for controlling the amount of the supplementary fuel fed into the intake system. This amount of the supplementary fuel is rapidly increased when the total air-fuel ratio is changed from the lean side to the rich side of the stoichiometric air-fuel ratio while the amount of the supplementary fuel is slowly reduced when the total air-fuel ratio is changed from the rich side to the lean side of the stoichiometric air-fuel ratio.

Abstract: An internal combustion engine having a main combustion chamber connected to an intake port for an air-fuel mixture, and an auxiliary combustion or a precombustion chamber communicated with the main combustion chamber through a plurality of torch apertures. The auxiliary combustion chamber is, before a combustion stroke of the engine, supplied through the torch apertures with an amount of the mixture for pre-combustion therein. A spark plug has a set of electrodes disposed in at least one of the torch apertures for causing the pre-combustion of the mixture in the auxiliary combustion chamber to thereby generate torch jets which are directed into the main combustion chamber to ignite the mixture therein.

Abstract: A torch-ignition internal combustion engine has a trap chamber formed in the engine cylinder head and communicated with a main combustion chamber through a plurality of torch apertures. An intake port extends through the cylinder head to the main combustion chamber to feed a charge of an air-fuel mixture thereinto when an intake valve is open on an intake stroke of the engine. At least one of the torch apertures is positioned and directed relative to the downstream end of the intake port such that a part of the mixture charge to the main combustion chamber flows through the one torch aperture into the trap chamber during the intake stroke of the engine to simultaneously force out the residual gases produced during a preceding combustion stroke through the other torch aperture or apertures into the main combustion chamber.

Abstract: A torch ignition type internal combustion engine has a main combustion chamber and a trap chamber having torch apertures through which both chambers are communicated with each other. The apertures are positioned such that, when the main chamber is supplied with a charge of an air-fuel mixture from an intake port on an intake stroke, a part of the mixture charge is introduced through one of the apertures into the trap chamber and the residual gases remaining therein are simultaneously discharged from the trap chamber into the main chamber through the other aperture. The trap chamber has a substantially smoothly continuous inner surface to which the one aperture is tangential so that the introduction of air-fuel mixture therethrough into the trap chamber produces therein a vortex flow which facilitates scavenging of the trap chamber.

Abstract: A torch-ignition internal combustion engine has a main and pre-combustion chambers communicated with each other through a torch aperture. Electrodes of a spark plug are disposed in the pre-combustion chamber at a point remote from the torch aperture. A fresh charge of a lean air-fuel mixture is supplied through an intake port into the main chamber on an intake stroke and compressed during a compression stroke so that a part of the fresh mixture charge is introduced through the torch aperture into the pre-combustion chamber.

Abstract: All of combustion chambers receive a lean air-fuel charge at low and medium engine power demands. As the engine power demand increases, a rich air-fuel charge is supplied to one or a suitable number of the combustion chambers with countermeasures being provided to suppress the formation of nitrogen oxides, such as, an exhaust gas recirculation (EGR) and the torch effect of a torch ignition system, the remaining combustion chambers, if any, receiving a lean air-fuel charge.Exhaust gases from all of the combustion chambers are converged to oxidize hydrocarbons and carbon monoxide formed by the combustion of the rich air-fuel charge when the combustion chambers respectively receive rich and lean air-fuel charges.

Abstract: A control system for an internal combustion engine wherein the torque developed by an internal combustion engine is detected to provide optimum control of the ignition timing of the engine and thereby to ensure an improved engine efficiency as well as an improved fuel economy. The system comprises an engine torque detector for detecting the torque developed by the engine, a signal generator for generating signals used to periodically change the ignition timing of the engine, a phase discriminator for discriminating the phase relation between the output signals of the engine torque detector and the periodic change signal generator, and ignition timing control means for controlling the ignition timing in response to the output of the phase discriminator.

Abstract: A method of operating a torch ignition type internal combustion engine having a main combustion chamber and a trap chamber always communicated therewith through first and second apertures provided in the trap chamber has the steps of supplying a charge of a lean air-fuel mixture into the main combustion chamber through an intake port and introducing another charge of a rich air-fuel mixture through the first aperture into the trap chamber. The rich air-fuel mixture charge is substituted in the trap chamber for residual gases produced therein during the preceding combustion stroke to discharge the residual gases through the second aperture whereby the trap chamber is scavenged.

Abstract: In an internal combustion engine having a plurality of sequentially operative combustion chambers, harmful components in exhaust gases are reduced. At least one of the combustion chambers is supplied with a rich mixture having a smaller air-to-fuel ratio than the stoichiometric air-to-fuel ratio and the remaining combustion chambers are fed with a lean mixture whose air-to-fuel ratio is greater than the stoichiometric air-to-fuel ratio. At the point where the exhaust gases emitted from the combustion chambers gather, the total air-to-fuel ratio of the rich and lean mixtures is detected producing a signal representing the total air-to-fuel ratio. One of the rich and lean mixtures is controlled in accordance with the air/fuel ratio signal to maintain the total air-to-fuel ratio practically at a predetermined value.

Abstract: A carburetor for an internal combustion engine of the stratified combustion type supplies a rich air-fuel mixture in the neighborhood of the ignition plug in each cylinder and a lean air-fuel mixture in the remaining space in the cylinder. The carburetor comprises an air horn, a fuel jet having a nozzle open to the air horn, and main and auxiliary ducts branching from the air horn downstream of the fuel nozzle and extending parallel to each other. Air-fuel mixture produced from both air introduced into the air horn and fuel supplied from the fuel jet is led to both the main and auxiliary ducts. At this time, the rich air-fuel mixture is collected in the auxiliary duct, which is closer to the fuel nozzle, and lean air-fuel mixture is collected in the main duct, which is spaced further from the fuel nozzle. The main and auxiliary ducts are respectively provided with main and auxiliary throttle valves, which are controlled by the accelerator pedal.

Abstract: A torch ignition internal combustion engine has a main combustion chamber for the combustion of a lean air-fuel mixture and an auxiliary combustion chamber for the combustion of a rich air-fuel mixture. The auxiliary combustion chamber has a suction and a discharge apertures open to the main combustion chamber. The suction aperture is located near to a valve seat for an intake valve so that the auxiliary combustion chamber is communicated with an intake port through the suction aperture and a part of the main combustion chamber when the intake valve is opened. The intake port is connected at its upstream end to an air intake pipe.

Abstract: A torch ignition type internal combustion engine has a trap chamber comprising a cup-shaped member of a heat-resistant metal mounted on a cylinder head of the engine. The member has a substantially closed end protruding into a main combustion chamber and suction and discharge apertures through which the trap chamber always communicates with the main combustion chamber. A single intake port is provided in the cylinder head for supplying air-fuel mixture charges to both the main combustion chamber and trap chamber.

Abstract: A stratified internal combustion engine has a main combustion chamber for receiving a lean air-fuel mixture, a trap chamber for receiving a rich air-fuel mixture, a primary intake port for supplying the lean air-fuel mixture to the main combustion chamber, a secondary intake port for supplying the rich air-fuel mixture to the trap chamber and a partition between the primary and secondary intake ports. The primary and secondary intake ports merge at their upstream ends into a single general passage defined by an intake manifold. A single fuel injection nozzle is mounted on the intake manifold to inject fuel toward the upstream end of the partition so that the injected fuel is divided and distributed by the partition into the primary and secondary intake ports and thus into the main combustion chamber and the trap chamber, whereby a stratified combustion is achieved by a simplified engine construction.

Abstract: A fuel reforming system for use in an intake system for an internal combustion engine operable with a hydrocarbon fuel has a spark plug or plugs for intermittently producing spark discharges to cause imperfect combustion of a rich air-fuel mixture so that a part of the fuel is reformed into intermediate combustion products and the large portion of the remainder of the fuel is vaporized by the heat produced by the imperfect combustion, whereby the reformed mixture is made optimum for combustion to thereby enable the engine to perform an optimum operation.

Abstract: There is provided a fuel economizing system comprising a constant speed control unit for varying the opening of a throttle valve to reduce the difference between the preset vehicle speed and the actual vehicle speed, fuel pattern setting means for setting the quantity of fuel required by an internal combustion engine, and fuel pattern correcting means for detecting the difference of the vehicle speeds and the variation of the quantity of fuel fed to the engine and correcting the fuel quantity set by the fuel pattern setting means, whereby the quantity of fuel fed to the engine is reduced while maintaining the constant speed driving function.

Abstract: An exhaust gas recirculation valve comprising a back pressure control chamber connected with the exhaust pipe of an internal combustion engine via a throttling means, a membrane which constitutes a part of the wall defining said back pressure control chamber, the outside surface of said membrane being exposed to the atmospheric pressure while the inside surface of said membrane being closely opposed by an open end of a gas outlet tube so that said membrane and said open end constitute a valve structure for controlling the exhaust gas flow through the exhaust gas recirculation valve.