Nippon Soken, Inc.

Toyota Jidosha Kogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Daihatsu Kogyo Kabushiki Kaisha

Yukiyasu Tanaka

Masaaki Noguchi

Taro Tanaka

Masaharu Sumiyoshi

Isao Igarashi

Setsuro Sekiya

Katsuhiko Motosugi

Tsuchio Bunda

Norikatsu Uejima

Junichi Ono

Akira Shimoura

Eiji Toyoda

Katuhiko Motosugi

A two-stroke cycle gasoline or diesel engine having: at least two two-stroke cycle power cylinder - piston assemblies each having two horizontally opposed pistons, incorporating uniflow scavenging, and operating with a phase difference of 180.degree. relative to each other; at least one double acting scavenging pump cylinder - piston assembly which has two horizontally opposed pistons and is driven by the power cylinder - piston assemblies by way of a pair of mutually synchronized common crankshafts and crank mechanisms which connect the pistons of the power cylinder - piston assemblies and the pump cylinder - piston assembly with the common crankshafts, wherein the crank radius of the common crankshafts with respect to the pump cylinder - piston assembly is substantially smaller than that with respect to the power cylinder - piston assemblies.

Two-stroke cycle engine

A two-stroke cycle gasoline engine, comprising a power cylinder-piston assembly having a scavenging port configuration including a first scavenging port configuration first uncovered by the power piston as it moves along the power cylinder from its top dead center to its bottom dead center and a second scavenging port configuration uncovered by the power piston as it moves from its top dead center to its bottom dead center immediately after said power piston has completed uncovering the first scavenging port configuration, wherein the general rate relative to piston position in the power cylinder of uncovering of the area of the first scavenging port configuration is substantially lower than that of the second scavenging port configuration, so that the idling and low-load performance of the engine is substantially improved by improving scavenging.

Two-stroke cycle gasoline engine

A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder-piston assembly incorporating uniflow scavenging and two horizontally opposed pistons and two crankcases to perform crankcase compression, and at least one scavenging pump cylinder-piston assembly of the reciprocating type, wherein the power assembly has main and additional scavenging ports; the pump assembly has a first delivery port which supplies scavenging mixture to one of the crankcases of the power assembly and a second delivery port which supplies scavenging mixture directly to the additional scavenging port, the main scavenging port being supplied with scavenging mixture from the crankcases, wherein the top dead center of the pump assembly is, as viewed in the crank angle diagram, between the bottom dead center and the main scavenging port closing phase point of the power assembly, and wherein a means is provided so as to interrupt the supply of scavenging mixture from the first delivery port of the pump assembly to the one crankcase from a phase point located between the main scavenging port opening phase point and the bottom dead center of the power assembly to at least the top dead center of the pump cylinder-piston assembly.

A method for operating a two-cycle internal combustion engine wherein in the scavenging stroke the air-fuel mixture charged into the cylinder forms a stratum adjacent to a piston and the stratum of the air-fuel mixture is made into contact with the stratum of the residual gases remote from the piston. Alternately, in the scavenging stroke the rich mixture is first charged into the cylinder immediately above the piston and then the lean mixture is charged into the cylinder immediately above the piston so that the strata of the lean and rich mixtures and the residual gases may be formed in the order named from a portion close to the piston within the cylinder. The decomposition of part of the air-fuel mixture or the rich air-fuel mixture is caused by the heat contained in the residual gases so that the chemically activated radicals are produced. In the compression stroke the air-fuel mixture or the rich air-fuel mixture containing these radicals is compressed to the compression ratio of between 4 and 10 and ignited and burned by the radicals mentioned above. The engine may operate with a low compression ratio. The engine may be made light in weight as compared with the diesel engines. The compression combustion is effected. The positive ignition may be ensured and the irregular and uncomfortable noise and vibration may be minimized. In addition, a considerable fuel economy may be attained and the emission of HC may be minimized. The two-cycle internal combustion engines adapted for carrying out the above method are also disclosed.

Two-cycle internal combustion engine

A two-stroke cycle gasoline engine including at least one two-stroke cycle uniflow scavenging power cylinder-piston assembly which has a scavenging port configuration which consists of first, second, and third scavenging port configurations which are successively uncovered by the power piston as it moves from its top dead center to its bottom dead center, wherein the first scavenging port configuration has a substantially smaller opening area than the second or the third scavenging port configuration, and the first and the second scavenging port configurations give substantially stronger swirl to fuel-air mixture discharged therefrom than the third scavenging port configuration, which gives substantially no swirl to fuel-air mixture discharged therefrom, and the first and second port configurations are closed when the engine is operating at relatively low load above idling and below a predetermined delivery ratio, such as 0.4.

A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder-piston assembly adopting uniflow scavenging and incorporating two horizontally opposed pistons, and at least one scavenging pump cylinder-piston assembly of the reciprocating type with or without having crankcase compression, wherein the total stroke volume of the scavenging pump means is 1.35 to 1.85 times as large as that of the power cylinder-piston assembly, and the operational phase of the pump cylinder-piston assembly is shifted from that of the power cylinder-piston assembly by an angle of 180.degree. or a little more.

A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder - piston assembly incorporating uniflow scavenging and two horizontally opposed pistons, and a scavenging structure which gives zero or a relatively weak swirl to the scavenging mixture ejected into the power cylinder so as to effect stratified scavenging of exhaust gases when the engine is operating at relatively low load and which gives a relatively strong swirl to the scavenging mixture ejected into the power cylinder so as to cause high turbulence in the mixture when the engine is operating at relatively high load.

A two-stroke cycle diesel engine having at least one two-stroke cycle power cylinder-piston assembly incorporating uniflow scavenging and having two horizontally opposed pistons, at least first and second scavenging ports and two crankcases which may perform crankcase compression; a pump assembly including at least one scavenging pump cylinder-piston assembly of the reciprocating type which is separate from and is driven by the power cylinder-piston assembly; a scavenging air introducing device which introduces scavenging air compressed by the pump assembly to the first and the second scavenging ports through first and second passage systems, respectively; and a fume generating device incorporated in the second passage system and supplying fuel mist in an initial part of the air supplied through the second passage system; wherein the fume is supplied as stratified with exhaust gases so as to be heated by the exhaust gases toward decomposition and then the first passage system is interrupted before the pump assembly reaches its top dead center so that thereafter the scavenging air compressed by the pump assembly is all supplied to the second scavenging port thereby generating strong swirl flows in the power cylinder.

Two-stroke cycle diesel engine

A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder--piston assembly having two horizontally opposed pistons and incorporating uniflow scavenging, a reciprocating type scavenging pump means including at least one pump cylinder--piston assembly of the reciprocating type driven by the power cylinder--piston assembly in synchronization therewith, wherein the carburetor incorporates, in addition to a normal throttle valve, a control valve which automatically increases its opening as the rotational speed of the engine increases, so that, when it is set to provide its maximum opening at the maximum rotational speed of the engine, it provides gradually reduced opening as the rotational speed of the engine lowers.

A two-stroke cycle diesel engine having: at least one two-stroke cycle power cylinder - piston assembly incorporating uniflow scavenging and having two horizontally opposed pistons, at least first and second scavenging ports and two crankcases which may perform crankcase compression; a pump assembly including at least one scavenging pump cylinder - piston assembly of the reciprocating type which is separate from and is driven by the power cylinder - piston assembly; and a scavenging air introducing device which introduces scavenging air compressed by the pump assembly to the first and the second scavenging ports through first and second passage systems, respectively; wherein the first passage system is interrupted before the pump assembly reaches its top dead center so that thereafter the scavenging air compressed by the pump assembly is all supplied to the second scavenging port which is adapted to generate strong swirl flows in the power cylinder when scavenging air at high pressure is supplied in a large amount.

A metering and distribution device for a fuel injection system of an internal combustion engine includes a housing with a fuel inlet port connected to a fuel pump and a circumferential row of fuel outlet ports respectively connected to fuel injectors for respective engine cylinders. A rotor, rotatably mounted in the housing, is provided with an orifice and rotates in a timed manner with the engine. A control member is telescopically mounted on the rotor and moves axially thereon in accordance with variations in the flow rate of intake air and has a circumferential row of orifices equal to the fuel ports and cylinders. The inner member, whether the rotor or control member, has an axially extending fuel passage connected to the inlet port and the rotor's rotation moves the rotor's orifice into overlapping communication with successive orifices in the control member and thus to fuel outlet ports and respective cylinders. The angle of the rotor's rotation during which communication between the rotor's orifice and each control member orifice lasts is varied in accordance with variations in the flow rate of engine intake air thereby accurately metering fuel charges to respective cylinders. Orifice members of substantially the same flow characteristic are removably mounted in respective fuel outlet ports to provide fixed restriction orifices which have a fuel flow cross-sectional area smaller than the area over which the orifices in the rotor and the control member are communicated, whereby the amount of each fuel charge to the engine is solely dependent upon the duration of the communication between the orifices in the rotor and the control member.

Fuel injection system for an internal combustion engine

In a uniflow, double-opposed piston type two-cycle internal combustion engine of the type having first and second crank chambers attached to the ends of a cylinder, first and second pistons disposed in the first and second crank chambers, respectively, and slidably fitted into the cylinder so as to move toward and away from each other, an exhaust port formed through the cylinder wall and opened and closed by the first piston, and a plurality of scavenging ports formed through the cylinder wall and opened and closed by the second piston, an improvement comprising means for feeding the rich air-fuel mixture to some of the scavenging ports, means for feeding the lean air-fuel mixture or the air to the remaining scavenging ports, and the lean mixture or air scavenging ports being uncovered and opened earlier than the rich mixture scavenging ports, whereby the scavenging efficiency may be improved and the amount of air-fuel mixture escaping through the exhaust port together with the combustion products may be minimized. In addition, the first piston is advanced in phase by a predetermined degree over the second piston so that the compression ratio may be increased and consequently the engine output may be increased.

Uniflow, double-opposed piston type two-cycle internal combustion engine

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.

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. The rotation of the rotor brings at least one of the orifices therein into overlapping and communicating relationship to successive apertures of the corresponding set so that the fuel flows from the fuel passage through the overlapped and communicated orifice and apertures to the associated fuel outlet ports and thus to the associated fuel injectors. Relative movement between two orifices and two sets of apertures axially of the rotor is caused when the rate of engine intake air flow is varied. The arrangement is such that, when the rate of the intake air flow is within a first range smaller than a predetermined rate, only one of the orifices is brought into overlapping and communicating relationship to successive apertures of the associated set and such that, when the intake air flow rate is within a second range greater than the predetermined rate, both orifices are brought into overlapping and communicating relationship to successive apertures of the two sets, respectively, whereby fuel supply to respective engine cylinders is increased when the intake air flow rate is increased beyond the predetermined rate.

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.

Growing community of inventors

Okazaki, Japan

Yukiyasu Tanaka