Abstract: A two-cycle engine has a scavenge pump provided in an intake passage, and a fuel injector provided for injecting fuel directly in a cylinder of the engine. A scavenge pressure sensor is provided in the intake passage for detecting a scavenge pressure. A plurality of data relative to quantity of air induced in the cylinder excluding escape air at scavenging the cylinder are stored in a memory. Quantity of air is derived from the memory in accordance with the detected scavenge pressure. Quantity of fuel injected by the fuel injector is calculated based on the derived quantity of air induced in the cylinder.

Abstract: A conversion kit for V-twin motorcycles to convert them from carbureted to fuel injection.

Abstract: A method and apparatus for controlling the idling rotational speed of a direct fuel injected, crankcase scavenged, two-stroke engine are disclosed. This is accomplished by regulating the timing of engine fuel injection within the rotational cycle of the engine. If the engine idling speed is outside a predetermined range of speeds, containing a target idling speed, the timing of fuel injection is advanced within the rotational cycle of the engine to increse idling speed, or retarded to decrease idling speed. The value by which fuel injection timing is advanced or retarded is determined by the difference between the actual idling speed and the target idling speed. The target idling speed is made a function of engine operation temperature to assure that a cold engine will idle properly when first started. After fuel injection timing is changed, a predetermined period of time is waited before repeating the idle control steps, to allow engine speed to stabilize.

Abstract: A method of operating a two-stroke spark ignition engine (9) wherein the fuel is injected directly into the engine combustion chamber (22). The timing of the injection of the fuel and the ignition of the fuel charge are varied according to engine load and speed conditions. Under low load and speed conditions substantially all the fuel is injected after closure of the exhaust port (20) and the fuel charge is ignited between 40 and 70 degrees of crank angle rotation before the top dead center point of the engine cycle. Under high load conditions substantially all the fuel is injected before exhaust port closure.

Abstract: A two-stroke engine having at least one cylinder in which a piston is movably accommodated, with a crank case communicating with one end of the at least one cylinder. Air is admitted to the crank case and at least one pipe admits unmixed air from the crank case to a cylinder transfer port. The fuel is pneumatically injected into the cylinder by way of a pneumatic injector and a pipe connected to the crank case by a valve and forming a volume of pressurized air connected to the pneumatic injector supplies the pneumatic injector with pressurized air for atomizing the fuel. An exhaust pipe is connected to the at least one cylinder by an exhaust port located in a position offset in a direction of travel of the piston with respect to the cylindrical transfer port of the cylinder.

Abstract: A two-stroke engine having an intake valve and an exhaust valve which are arranged on the cylinder head. A masking wall is formed on the inner wall of the cylinder head to mask the valve opening between the valve seat and the peripheral portion of the intake valve, which is located on the exhaust valve side, for the entire time for which the intake valve is open. Due to the masking wall, fresh air fed into the cylinder is turned around a central axis perpendicular to the axis of the cylinder. A fuel injector is arranged on the inner wall of the cylinder on the central axis to inject fuel therefrom along the central axis.

Abstract: The invention provides an internal combustion engine comprising a cylinder having a head end and adapted to have air and fuel combusted therein and a piston reciprocate therein relative to the head end, an exhaust port adapted to conduct combusted air and fuel from the cylinder, structure defining an accumulation chamber, a passageway communicating with the accumulation chamber and with the cylinder at a predetermined position located between the exhaust port and the top dead center position, and structure for blocking the passageway in response to travel of the piston toward the head end and to passage of at least a portion of the piston over the predetermined position, so that the accumulation chamber is substantially prevented from receiving combusted air and fuel when the piston travels away from the head end.

Abstract: Fuel injection arrangements having pneumatically driven injection pumps utilize the fluctuating crankcase pressure whereby the injection time point is fixed by the system. The injection time point can be fixed so as to depart from the course of the pressure in the crankcase if the crankcase pressure is applied to the injection pump via an opening controlled by the piston and if the pressure drop is directed to the combustion chamber via a relief opening. However, it has been shown that this kind of control produces considerable problems with respect to fast-running two-stroke engines. Accordingly, it is a feature of the invention to provide a check valve in the connection between the relief opening and the injection pump and to position this check valve so that it opens in the flow direction toward the combustion chamber.

Abstract: A two-stroke-cycle uniflow spark-ignition engine generates power by pressurizing fluid introduced into a crank chamber within the crank chamber with a piston as it moves toward its bottom dead center, feeding the pressurized fluid to an annular scavenging chamber provided on the entire periphery of a cylinder where it accumulates, and discharging the fluid in the annular scavenging chamber into a cylinder chamber provided above the piston from a plurality of scavenging ports which are opened at the end of the descending stroke of the piston as a scavenging fluid in the form of a swirling uniflow.

Abstract: Method and apparatus for controlling emissions, particularly of unburnt hydrocarbons, from a two stroke engine. The engine has direct in-cylinder fuel injection and has in the air inlet port and the exhaust port respective devices to control the flow therethrough. The devices are each independently controlled in relation to engine load demand and engine speed to regulate the mass of exhaust gases retained in the combustion chamber. The exhaust flow control device perferably also alters the timing of opening and closing of the exhaust port.

Abstract: An internal combustion 2-stroke engine having at least one combustion chamber equipped with a delayed fuel supply system opening into a cylinder head. A wall of the cylinder has at least one exhaust port situated in the vicinity of a first referernce point through which passes a first axial plane of the cylinder or exhaust plane and at least one intake port situated in the vicinity of a second reference point, or intake reference point. A plane perpendicular to the exhaust plane and containing the axis of the cylinder defines two accommodation zones in the cylinder with the first accommodation zone, complementary to the second one, containing the reference point of the exhaust port, and the supply system is situated in the second accommodation zone.

Abstract: An intake manifold and cylinder head intake passageway for an air-cooled internal combustion engine. The manifold is substantially S-shaped and generally vertically oriented and communicates a carburetor having a horizonal bore with an overhead valve cylinder head having a horizontal intake passageway located at an elevation above that of the carburetor. The manifold has a turbulence inducing ridge at the entrance from the carburetor and the cylinder head intake passageway has a similar ridge at the entrance from the manifold. Each elbow bend in the manifold and in the cylinder head passageway is provided with a flat area at the outside curve of the bend which prevents puddling of fuel in the arcuate section of the bend and which causes any fuel which collects there to be spread out in a thin film which is then reintroduced into the air stream by a wedge-shaped ridge transverse to the flat area and rising therefrom to a ridge peak.

Abstract: A low pressure fuel injection system, especially suitable to be applied to a two-stroke gasoline engine, mainly comprises a solenoid-operated fuel injector which is mounted on cylinder wall in order to inject fuel directly into cylinder. The injector has a specially-designed injection valve assembly including a valve needle and a valve body that could execute in-cylinder injection under low fuel pressure, eg. 3 kg/cm.sup.2, without causing any problem accompanied with.

Abstract: The invention relates to a two-stroke engine having an overflow channel through which an air/fuel mixture is supplied. The overflow channel is provided with a vaporization chamber having a hot wall against which fuel is injected and vaporized. The vaporized fuel is stored in the vaporization chamber and is carried into the combustion chamber of the engine by fresh air flowing in from the crankcase when the overflow channel is opened. Even at high rotational speed, a good mixture preparation is asssured.

Abstract: Disclosed herein is an internal combustion engine comprising a cylinder, a piston reciprocal in the cylinder, an accumulation chamber, a supply conduit which includes a valve and which communicates between the cylinder and the accumulation chamber for supplying pressure gas from the cylinder to the accumulation chamber in response to piston reciprocation to thereby accumulate pressure gas in the accumulation chamber, a discharge conduit which includes a valve and which communicate between the accumulation chamber and the cylinder and is operative to selectively mix pressure gas from the accumulation chamber with fuel under pressure and to discharge the resultant fuel/gas mixture into the cylinder, and a fuel injector adapted to communicate with a source of fuel and operative to supply fuel under pressure to the discharge conduit at a pressure sufficient to open the valve in the discharge conduit and to mix pressure gas from the accumulation chamber with the fuel under pressure and discharge the resultant fuel

Abstract: A two-cycle internal combustion engine is described having a combination of a combustion chamber portion at one end of the cylinder for receiving predetermined amounts of air and fuel; inlet ports for injecting fuel and compressed air into the upper end of the combustion chamber portion; exhaust ports in the cylinder for the conduction of exhaust gases and air from the combustion chamber portion, said exhaust port means being covered and uncovered by the side of the piston means and positioned to be fully uncovered at the bottom dead center position of the piston; a fuel/air mixing system in communication with the inlet ports the system having an air supply for providing a continuous supply of compressed air to the combustion chamber portion, a supply of compressed air generated by the engine, a fual supply for providing predetermined quantities of fual at specified intervals, and, a precombustion chamber for receiving and mixing the compressed air and the predetermined quantities of fuel and providing the co

Abstract: A pneumatically operated fuel injection pump has a work chamber which is partitioned by a membrane into a pulse chamber and a return chamber. The pulse chamber is charged with crankcase pressure from a two-stroke engine while a counterforce is built up in the return chamber which varies with rotational speed. A counterforce is developed by means of a precise pressure control in the return chamber which makes possible a highly precise injection adapted to rotational speed. For this purpose, the return chamber is connected with an adjusting volume via a throttled flow path. In addition, a leaf spring is mounted in the return chamber and is utilized as a return spring for the membrane.

Abstract: In a two stroke fuel injection type internal combustion engine provided with intake and exhaust valves, a basic amount of fuel to be injected is calculated in accordance with an engine load and engine speed. Values of a factor corresponding to a ratio of air captured by an engine cylinder for combustion to the total amount of air introduced into the engine are stored in a memory in accordance with combinations of an engine load and engine speed. A value of a captured air factor corresponding to a detected combination of an engine load and speed is calculated by a map interpolation. The basic amount is corrected by the captured air factor so that a desired air-fuel ratio is obtained. The captured air factor may be further corrected in accordance with a secondary engine condition, other than an engine load and speed, such as a cooling water temperature, intake air temperature, atmospheric air temperature, atmospheric air pressure, exhaust gas temperature, or intake pressure.

Abstract: An internal combustion engine includes a single sluice (3) which opens asymmetrically and one-sidedly in an exhaust channel (5) and which runs tangentially within the cylinder (1), diagonally to the cylinder head. A rotating flow is thus obtained in the cylinder along its inner wall, thus ensuring a complete and reliable ignition, a low fuel consumption and a low pollutant content in the exhaust gases.

Abstract: The invention relates to a fuel injection arrangement wherein the pump piston of the fuel pump is driven by the pressure in the crankcase of the engine. The fuel injection arrangement includes an opening for tapping the crankcase pressure for actuating a diaphragm in the fuel pump. This opening is controlled by a moving part of the engine such as a crank web or the piston. The moving part closes the opening at least for a portion of the time during which injection occurs thereby delaying the onset of injection to permit a complete combustion during the previous combustion cycle.

Abstract: A method of operating a two-stroke spark ignition engine (9) wherein the fuel is injected directly into the combustion chamber (22). The timing of the injection of the fuel is varied according to engine load and speed conditions. Under low load and speed conditions at least 80% of the fuel is injected after closure of the exhaust port (20) whereas under some high load conditions at least 80% of the fuel is injected before closure of the exhaust port (20). The method may also comprise adjustment of ignition timing so that, in conjunction with low load and speed conditions, ignition occurs at least 5.degree. of crankshaft rotation after commencement of fuel injection and up to 70.degree. before top dead center of the engine cycle.

Abstract: The invention is directed to a fuel injection arrangement for two-stroke engines for portable tools such as motor-driven saws. In known fuel-injecting arrangements, the injection pump is driven by the pressure of the crankcase. The crankcase pressure increases up to a maximum value which remains constant starting with a predetermined rotational speed up to and including the maximum rotational speed. When the peak pressure of the crankcase is constant, the stroke of the pump piston of the injection pump is also constant and so is the quantity of fuel which is pumped. However, at higher speeds where the speed is increasing because of throttling in the air intake channel, the air charge of the cylinder reduces and an overrich mixture is formed. The fuel injection arrangement of the invention provides for an automatic reduction in the quantity of fuel injected at high and at the highest speeds.

Abstract: A two- or four-stroke internal combustion engine is provided having individual features and combinations of features not heretofore known which provide enhanced power, efficiency and braking performance compared to known engines.

Abstract: A method of injecting fuel to an internal combustion engine (9) comprising introducing a metered quantity of fuel into a scheduling chamber (32) from where it is injected by pressurized gas into the combustion chamber or induction system of the engine (9). The rate and/or time of introduction of the fuel to the scheduling chamber (32) is controlled in relation to the period of injection to achieve a predetermined fuel distribution in the combustion chamber at ignition. An axial stratification of fuel in the combustion chamber can be produced.

Abstract: It is a fuel injection apparatus using low pressure compressed air to assist the atomization of the fuel. It comprises a compressed air source, a circulating fuel circuit, a fuel solenoid valve, an air solenoid valve, a fuel-and-air mixing fixture, atomized-fuel passage and nozzles.

Abstract: In a two-stroke spark ignition engine, fuel is injected through the cylinder wall at a location opposite to and above the level of the exhaust port (120). The fuel is delivered in the form of a number of streams such as, for example, streams (60), (61), (62). One of the streams (60) is directed upwardly across the cylinder to deliver fuel towards the combustion chamber cavity (122). This stream (60) is arranged not to impinge on the spark plug (123) but is caused to create a fuel rich cloud within the cavity (122). Streams (62) are directed downwardly and outwardly from the injection location and an optional stream (61) may be directed across the cylinder towards the exhaust port side of the cylinder.

Abstract: A method and apparatus for injecting fuel into a combustion chamber of an internal combustion engine particularly of two stroke cycle spark ignited engine, wherein a metered quantity of fuel is entrained in a gas, and the fuel and gas mixture so formed is delivered through a nozzle into the combustion chamber under conditions that will establish a fuel spray having a dispersion velocity in the direction of the spray axis of not more than 25 meters/sec at 35 millimeters of spray penetration from the nozzle when measured in still air atmospheric pressure, and preferably that dispersion velocity is not more than 18 meters/sec at 70 millimeters from the nozzle.

Abstract: The invention is directed to a method of fuel injection for two-stroke engines, especially for hand-operated tools such as motor-driven saws and the like. The fuel-injection pump is charged with pressure present in the crankcase thereby causing fuel to be pumped for injection and combustion in the engine. The injection operation is triggered and the onset of injection into the combustion chamber is effected when the crankcase pressure rises. The pressure conducted from the crankcase to the injection pump can be automatically regulated as a function of the rotational speed and/or load conditions of the engine.

Abstract: A fuel supplying system for a two-cycle crankcase compression internal combustion engine. A first charge forming device supplies a fuel/air charge to the crankcase and a second charge forming device supplies a fuel/air charge to the scavenge passage that connects the crankcase with the combustion chamber. A check valve is positioned in the scavenge passage so as to prevent reverse flow and the discharge of the second charge forming device is related to the check valve so as to improve the fuel delivery.

Abstract: The two-cycle internal combustion engine has a crankcase, a combustion chamber including an exhaust port, a fuel intake port and a pair of air-intake ports located on the opposite sides of the fuel intake port, and a piston movable relative to the combustion chamber between top dead center and bottom dead center positions. The crankcase has separate air and fuel inlets and includes interior portions defining an air crankcase portion which communicates with the crankcase air inlet and with two air transfer passages which communicated with the air intake ports and a separate fuel crankcase portion which communicates with the crankcase fuel inlet and a fuel transfer passage which communicates with the fuel intake port. Air is drawn through the crankcase air inlet into the air crankcase portion and a fuel-air mixture is drawn through the crankcase fuel inlet into the fuel crankcase portion during the upstroke of the piston toward top dead center.

Abstract: A fuel injection control method and system for a crankcase compression two cycle engine wherein the amount of fuel discharge is controlled by the pressure in the crankcase.

Abstract: A 2-stroke engine having a combustion chamber and a scavenge port which is open to the combustion chamber. When the engine is operating under a light load in which a large amount of unburned components, incompletely burned components and oxygen remains in the combustion chamber, fresh air is fed into the combustion chamber from the scavenge port at a low speed so that the fresh air does not disturb the residual gas in the combustion chamber. As a result of this, oxidation of the unburned components and the incompletely burned components continues without interruption during the expansion stroke and the compression stroke and causes self-ignition of the residual gas at the end of the compression stroke. The self-ignited residual gas causes ignition of the fuel injected into the combustion chamber from a fuel injector.

Abstract: A two-cycle engine (10) has an idle fuel system which admits fuel-air mixture into the transfer passages (22). Heated air is supplied to the idle mixing passage (42) by a serpentine air passage (45), while fuel from the carburetor float bowl (33) is supplied through a needle valve (50). A reed valve (43) admits the idle mixture to the transfer passage (22).

Abstract: The invention contemplates electronically controlled fuel-injection for a single or multiple-cylinder two-cycle internal-combustion engine wherein each cylinder has its own independent crankcase region in which to receive and compress inlet air and fuel, prior to delivery of combustible mixture to the head or combustion end of the cylinder. Fuel is injected directly into each crankcase region during only a portion of the stroke involving induced intake of air therein, i.e., during only a portion of the rise of each piston in its approach to top-center position, and while pressure within the crankcase region is relatively uniform. The time-duration of actual injection is relatively short, to enable identical injections in each cylinder, each such injection being identically timed with relation to position and displacement of its associated piston.

Abstract: Disclosed is an internal combustion engine capable of creating an active thermoatmosphere in the combustion chamber at the beginning of the compression stroke. The active thermoatmosphere continues to be maintained during the compression stroke when the engine is operating under a partial load. The self ignition of the active thermoatmosphere is caused in the vicinity of the top dead center position.

Abstract: A stepped piston two cycle engine, of the type including at least one set of two cylinders each such cylinder having a working part of smaller diameter and a pumping part of larger diameter, at least the air for each charge required by the working part of each cylinder of the set being pumped along transfer passage means from the pumping part of the other cylinder of the set, has the working part of each cylinder provided with exhaust port means, main inlet ports, and auxiliary inlet port means. The main inlet ports are arranged symetrically about and spaced from a plane which contains a longitudinal axis of the cylinder and which passes through the center of the exhaust port means, and the auxiliary inlet port means is provided in the cylinder wall opposite to the exhaust port means.

Abstract: A hydrocarbon fuel is subjected to combustion in an internal combustion engine by the use of excess air, and the exhaust gas is utilized as heat and oxygen sources for partial oxidation of the hydrocarbon fuel in a separate reformer. A resulting mixture of the reformed gas and the exhaust gas is subjected to heat exchange with air to be drawn into the engine and/or the fuel to be supplied to the reformer and thereafter is supplied to a larger internal combustion engine.

Abstract: The invention is an improved piston and cylinder arrangement for a loop charged two-stroke engine wherein all input passages are open channels in the cylinder wall and the top annular edge of the piston is rounded. The rounded edge on the piston cooperates with the described scavenging and input passages to reduce drag and, cause the incoming charge to flow more horizontally over the piston head; thereby improving scavenging and volumetric efficiency.