Abstract: A two-stroke cycle gasoline engine including at least one two-stroke power cylinder-piston assembly incorporating uniflow scavenging and two horizontally opposed pistons, and at least one scavenging pump cylinder-piston assembly of the reciprocating type, wherein the total stroke volume of the scavenging pump assembly is 1.15-1.65 times as large as that of the power cylinder-piston assembly, and the operational phase relation between the power and pump cylinder-piston assemblies is so determined that the top dead center of a pump cylinder-piston assembly is, as viewed in the crank angle diagram, in a range between 15.degree. in advance of and 15.degree. behind the midpoint between the bottom dead center and the scavenging port closing phase point of the power cylinder-piston assembly to which the pump cylinder-piston assembly supplies scavenging mixture.

Abstract: A fuel injection system for an internal combustion engine has two sets of fuel injectors mounted on the engine so that each engine cylinder is provided with two injectors. A fuel metering and distributing device meters a fuel under pressure from a fuel source and distributes the metered fuel to respective injectors. The fuel metering and distributing device includes a housing provided with a fuel inlet connected to the fuel source and two sets of fuel outlet ports each connected to one of the fuel injectors. A rotor is mounted in the housing for rotation in timed relationship to the engine operation and is provided with an axial fuel passage always in communication with the fuel inlet. Two orifices are formed in the peripheral wall of the rotor in communication with the fuel passage while two sets of apertures each communicated with one of the fuel outlet ports are formed either in the housing or in a control shaft disposed in the housing in telescopic relationship to the rotor.

Abstract: In a non-load operation of a multi-cylinder internal combustion engine, both suction flow of newly supplied air-fuel mixture to be introduced in a first combustion chamber and exhaust flow of combustion gas to be exhausted from the first combustion chamber or only the exhaust flow is throttled to carry out compression ignition combustion in the first combustion chamber, while suction flow of newly supplied air-fuel mixture to be introduced into a second combustion chamber is blocked to stop combustion in the second combustion chamber to increase a gas feed rate in the first chamber, to thereby cause a kind of run-on phenomenon in the engine in non-load condition.

Abstract: Disclosed is an internal combustion engine comprising a main combustion chamber and an auxiliary combustion chamber which are interconnected to each other via a connecting passage. The auxiliary combustion chamber symmetrically extends about an axis. The opening of the connecting passage is arranged on the periphery of the inner wall of the cylinder head and is directed in the circumferential direction of the inner wall of the cylinder head. A swirl motion creating means is provided for creating a swirl motion of the combustible mixture which rotates about the axis of the auxiliary combustion chamber at the time of the compression stroke. The spark gap of the spark plug is located on the axis of the auxiliary combustion chamber and in the deep interior of the auxiliary combustion chamber.

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: An internal combustion engine comprising a subsidiary combustion chamber connected to a main combustion chamber via a connecting passage. The subsidiary combustion chamber is divided into a first chamber and a second chamber by an annular raised portion formed on the subsidiary combustion chamber. The connecting passage communicates the main combustion chamber with the first chamber for leading a combustible mixture from the main combustion chamber into the first chamber and is arranged so as to create a swirl motion of the combustible mixture in the first and the second chambers. When the combustible mixture is ignited, the annular raised portion serves to prevent outflow of an unburned mixture from the second chamber to the first chamber.

Abstract: Disclosed is an internal combustion engine comprising a main chamber and an auxiliary chamber which are interconnected to each other via a connecting passage. The spark plug is located in the deep interior of the auxiliary chamber remote from the main chamber. The connecting passage comprises a first open end opening into the deep interior of the auxiliary chamber, and two second open ends opening into the main chamber. When the piston reaches the top dead center position, the main chamber defines therein two spaces having approximately equal volumes and including the corresponding second open ends. The second open ends are directed to the centers of the corresponding spaces.

Abstract: A torch ignition type internal combustion engine which has no intake valve in the auxiliary combustion chamber and which can effectively purge exhaust gases from the auxiliary combustion chamber to eliminate ignition failures, the engine comprising a cylinder; a cylinder head having a semi-spherical inner wall; a reciprocating piston snugly received in the cylinder; a main combustion chamber defined between the cylinder head and piston and having intake and exhaust valves to control intake and exhaust ports in the cylinder head; an auxiliary combustion chamber provided at a suitable position in the cylinder head; and a passage intercommunicating the main and auxiliary combustion chambers. The passage opens into the main combustion chamber at a position close to one of the intake valve and the exhaust valve. In one embodiment, the passage opens into the main combustion chamber at a position close to and substantially intermediate the intake and exhaust valves.

Abstract: A fuel reforming system for an internal combustion engine has a fuel reforming reactor to be supplied with a hydrocarbon fuel. The reactor contains a catalyst carrier and a catalyst thereon to be heated for facilitating a conversion of the fuel into a reformed gaseous mixture rich with hydrogen which mixture is to be fed into the engine. The catalyst is periodically alternately exposed to the fuel and air so that carbon produced and deposited on the catalyst during the fuel reforming reaction facilitated by the catalyst is burnt away from the catalyst carrier and the catalyst thereon whereby the catalytic performance of the catalyst is restored to ensure a prolonged operative life thereof. The reformed gaseous mixture assures a reliable ignition and combustion of a mixture thereof with air in the engine at a very lean air-fuel ratio to advantageously decrease the emission of harmful components of engine exhaust gas.

Abstract: A fuel reforming system for an internal combustion engine comprises a fuel circuit connected at its downstream end to the engine and including a carburetor for producing a rich air-fuel mixture and a fuel reforming reactor vessel containing a catalyst for facilitating a catalytic reformation of the mixture into a reformed gaseous mixture rich with free hydrogen. The carburetor is provided with a primary air intake passage with a venturi into which air and fuel are fed to produce a rich air-fuel mixture. The carburetor is also provided with a secondary air intake passage bypassing the venturi and connected to the fuel circuit downstream of the venturi. A valve is provided on the carburetor to control the cross-sectional area of the secondary air intake passage in accordance with the temperature in the engine or the reactor vessel, by the carburetor is adjusted according to the engine or reactor vessel temperature.

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 fuel reforming apparatus for use with an internal combustion engine, comprising hydrocarbon fuel supply means for producing a mixture of hydrocarbon fuel with air in a suitable air-fuel ratio, a burning chamber in which the mixture is ignited and burned, and a reactor which is packed with a catalyst adapted to carry out the catalytic reforming, with the aid of the heat of the combustion gases discharged out of the burning chamber, of the hydrocarbon fuel including little air to produce a reformed gas rich with hydrogen.

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: Disclosed is an internal combustion engine comprising a main combustion chamber and an auxiliary combustion chamber. The auxiliary combustion chamber comprises a first and a second auxiliary chambers. The first auxiliary chamber has a spark plug therein and is connected to the main combustion chamber. The second auxiliary chamber has a fuel injection nozzle therein and is connected to the first auxiliary chamber and to the main combustion chamber. Air or a lean air-fuel mixture is introduced into the main combustion chamber via the intake valve. An extremely rich air-fuel mixture is formed into the second auxiliary chamber. The extremely rich air-fuel mixture is introduced into the first auxiliary chamber and a combustible mixture is formed in the first auxiliary chamber. The combustible mixture is ignited and a burning gas is injected into the main combustion chamber.

Abstract: An auto emission purification catalyst which comprises palladium supported on a carrier composed mainly of .alpha.-alumina having a total porosity volume of 0.05-0.50 cc/g and an average porosity diameter of 0.05-0.5.mu..

Abstract: A fuel reforming system for an internal combustion engine comprises a fuel circuit connected at its downstream end to the engine and including a carburetor for producing a rich air-fuel mixture and a fuel reforming reactor vessel containing a catalyst for facilitating a catalytic reformation of the mixture into a reformed gaseous mixture rich with free hydrogen. The carburetor is provided with an air intake passage having a venturi into which a nozzle feeds the fuel from a float chamber to produce an air-fuel mixture. The nozzle has an open-bottomed end providing a fuel-metering orifice. A needle valve is movably mounted on the float chamber to control the cross-sectional area of the fuel-metering orifice in the nozzle in accordance with the temperature in the engine or the reactor vessel, whereby the air-fuel ratio of the air-fuel mixture produced by the carburetor is adjusted according to the engine or reactor vessel temperature.

Abstract: An internal combustion engine having an auxiliary combustion chamber connected to a main combustion chamber via multiple connecting holes is disclosed. The auxiliary combustion chamber has a drum shape. A first one of the connecting holes opens into the auxiliary combustion chamber in a direction tangential to the cylindrical circumferential wall of the drum shaped auxiliary combustion chamber for creating a swirl in the auxiliary combustion chamber at the compression stroke. An open end of the first hole on the main combustion chamber side is directed to the intake valve for scavenging the auxiliary combustion chamber at the intake stroke.

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.