Abstract: An air charging system includes a valve providing access to an engine cylinder, an accumulator coupled in flow communication with the valve, and a controller operable to open and close the valve until a threshold pressure condition is reached in the accumulator. Compressed gases stored in the accumulator are used in a fuel delivery system to prepare a charge of fuel that is delivered to an engine.

Abstract: A handheld work apparatus has an internal combustion engine (9, 9?, 9?) and a starter device (8). The internal combustion engine has a piston (10, 10?) which has at least one piston ring (37, 38). In order to avoid a delay when starting the engine, at least one recess is provided in the cylinder bore (26) which bridges the at least one piston ring (37, 38) in at least one position of the piston (10, 10?) and which has a distance (n, o, p) to all function openings of the engine (9, 9?, 9?) configured in the cylinder bore (26). To reduce the compression in the combustion chamber (25), the piston (10?) has only one piston ring (37) or two piston rings (37, 38) are provided having respective piston ring gaps (39, 40) defining an angle (?) which is up to approximately 45°.

Abstract: A method of operating a multi-cylinder compression ignition engine having at least one cylinder acting as a compression cylinder and at least one cylinder action as a combustion cylinder. The method comprise compressing air in the compression cylinder, and in the combustion cylinder, opening and then closing an exhaust valve during an exhaust stroke to trap some exhaust gas, during a compression stoke immediately following the exhaust stroke, injecting a controlled amount of fuel into the combustion chamber to obtain compression ignition at or near a top dead center piston position without reaching combustion temperatures at which NOX is formed, and injecting compressed air and fuel during a power stroke immediately following the compression stroke to sustain combustion to burn the fuel with an equivalence ratio within a predetermined range around unity. Various embodiments are disclosed.

Abstract: An engine fuel supply system is provided at a reduced cost by using a HC dosing pump that supplies fuel into an exhaust pipe also as a pump for a cylinder fuel supply device. When a signal is generated to command air removal from a cylinder fuel supply passage, the dual-purpose pump is activated, a first on-off valve assumes an open state, and a second on-off valve assumes a close state, so that the fuel is supplied from the dual-purpose pump to the cylinder fuel supply passage via an air-removal fuel supply passage. When a signal is generated to command fuel supply into the exhaust pipe, the dual-purpose pump is activated, the second on-off valve assumes the open state, and the first on-off valve assumes the close state, so that the fuel is supplied from the dual-purpose pump to the exhaust pipe via the exhaust-pipe fuel supply passage.

Abstract: Compression ignition engines and methods of the type wherein the engines operate with one cylinder used as a compression cylinder and a second cylinder used as a combustion cylinder. The engines have all cylinders configured so as to be able to operate as a compression cylinder or a combustion cylinder. In the method of operation, a cylinder may switch its operation between being a compression cylinder and then operate a combustion cylinder. Switching the operation between compression and combustion operation results in an even temperature distribution within the engine, and eliminates the need for special cooling requirements, facilitating retrofit of existing engines. Also use of an air storage tank allows all cylinders to operate as combustion cylinders for short bursts of power. Various other features are disclosed.

Abstract: An engine is cranked by a motor generator at a start time of the engine. An engine ECU opens an intake valve or an exhaust valve during a compression stroke using a valve control mechanism during a period from when cranking is started until when a predetermined crank angle position (detected by a crank angle sensor) is reached, thereby reducing a compression workload.

Abstract: One strategy for reducing undesirable emissions from internal combustion engines relates to finding ways to better mix fuel and air prior to combustion. One such method is commonly referred to as homogenous charge compression ignition (HCCI); however, that strategy is problematic in both controlling ignition timing and avoiding overstressing the engine at higher speeds and loads. The present invention addresses these issues by mixing air and fuel vapor within an injector instead of within the engine cylinder. The air/fuel mixture is then injected into the engine cylinder at some desired timing and over some desired duration. Such a strategy permits for lower emissions due to better mixing of air and fuel, while also permitting control over some aspects of combustion timing and duration not apparently possible with a conventional HCCI strategy. The present invention is generally applicable to all internal combustion engines, but especially applicable to diesel engines.

Abstract: An ignition method for a multi-cylinder reciprocating gas engine wherein, in order to start a combustion cycle, a compressed, substantially homogeneous and not self-igniting combustion gas-air mixture contained in the corresponding cylinder chamber to be fired is ignited by the direct injection of a small amount of combustion gas. The injected small amount of combustion gas, which serves as the ignition gas, is injected onto a hot surface in the region of the combustion chamber. The beginning of the injection is predetermined depending on the position of the crankshaft, and is controlled by an engine control unit.

Abstract: A pneumatic cylinder for actuating fume extraction valves in fume and heat extraction plants has a piston (2) that may be actuated from both sides with at least one working surface and that can be made to slide by pressurised air in a cylinder (1) with at least one working chamber (4), as well as an energy accumulator with regulating means. The regulating means can be controlled by control means to open or keep open the fume extraction valves. In order to obtain a compact pneumatic cylinder for a fume and heat extraction plant which is easy to install, a storage chamber in which air or pressurised air is stored as compressible pressure medium is provided as energy accumulator. The storage chamber is in communication with a compression surface (7) of the piston (2), at its side opposite to the working surface (7), so that pressure medium may flow between the storage chamber and the compression surface (7).

Abstract: An internal combustion engine is described having one or more combustion chambers 10 each having an intake port 16, a fuel injector assembly 30 for injecting fuel into the intake port 16 and means 20, 22, 24, 26 for supplying pressurised gas to assist in fuel atomisation of the fuel metered through the fuel injector assembly 30.The means for supplying pressurised gas comprises a passage 20, 24 incorporating a passive flow restrictor 22 having no moving elements. The passage 20, 24 leads from one of the combustion chambers 10 of the engine to the intake port 16 and is operative to deliver a single pulse of gas to the intake port 16 during each combustion cycle of the engine in order to assist in the atomisation of fuel which is injected into the intake port 16 at the same time as the pulse of gas.

Abstract: A reciprocating machine includes a cyclical kinematic chain in which power is transferred between translational and rotational motion. The kinematic chain includes a piston (2) reciprocating in a cylinder (1), connected by two connecting rods (9, 10) to dual counter rotating crankshafts (7, 8). The crankshafts (7, 8) are displaced symmetrically from the axis of movement of the piston (2), and the crank pins (15, 16) of the crankshafts (7, 8) to which the connecting rods (9, 10) are connected are symmetrically aligned about the axis of movement of the piston (2). The connecting rod small ends (13, 14) abut at their connection to the piston (2).

Abstract: A device for introducing fuel into the combustion chamber of an internal combustion engine, includes a unit for fuel delivery and an injection valve for withdrawing compressed gas from the cylinder and injecting the gas together with the delivered fuel into the cylinder, and a mixing space in the front part of the valve for the purpose of gas storage, the injection valve being provided with a valve for control of the gas exchange between the combustion chamber and the mixing space in the front part of the valve. To obtain reproducible operating conditions and an optimum closing time (E.sub.0) for the injection valve, the mixing space is connected to one or more sensor elements for measuring the pressure and/or temperature of the mixing space, and that the valve is closed in dependence on the physical quantity measured by the at least one sensor element.

Abstract: A device for introducing fuel into the combustion chamber of an internal combustion engine, includes an injection valve for withdrawing compressed gas from the cylinder and injecting the gas together with the fuel into the cylinder, a mixing chamber in the front part of the valve for the purpose of gas storage and into which mixing chamber fuel is introduced via one or more flow passages opening into the mixing chamber, the injection valve being provided with a lifting valve for control of the gas exchange between the combustion chamber and the mixing chamber in the front part of the valve, and an orifice where the flow passage opens into the mixing chamber located in the area of the seat of the lifting valve.

Abstract: A air charging valve for use with a air forced fuel injection system. The charging valve admitting and storing compressed air from the engine cylinder and releasing it into the fuel injector to force out the air/fuel mixture into the engine cylinder. The charging valve will accept the pressurized air from the engine cylinder without allowing any air to escape back into the combustion chamber once it is in the air charging valve. The fuel injection system includes an injector having a fuel and air mixing chamber that includes a normally closed injector valve; the chamber being for premixing air and fuel before introduction of the compressed air which causes the fuel injection event.

Abstract: A flexible line trimmer is powered by a two-stroke internal combustion engine. The engine is scavenged in a uniflow fashion and has a scavenging cylinder and an exhaust cylinder connected by a common combustion chamber. Each cylinder has a piston turning one of two cantilevered crankshafts that are geared through adjacent counterweights having integrally formed teeth. The crankshafts extend in opposite directions for self-balancing. One crankshaft is coupled to a flywheel fan and other coupled to a starter. A fuel and air mixture is transferred to a common crankcase for the crankshafts through an intake port located on the exhaust cylinder. The piston of the scavenge cylinder is retarded with respect to the exhaust cylinder. An exhaust window opens prior to a scavenge window. The scavenge window closes after the exhaust window. The exhaust window is shortened to improve crankcase compression. The cylinders are joined in a siamese fashion, fabricated from a single piece, and skewed toward each other.

Abstract: An engine including at least one cylinder in which a piston moves delimiting a combustion chamber and a housing, with at least one opening for allowing fresh air to enter the combustion chamber and one pneumatic injection device. The fuel is atomized or sprayed and injected into the chamber by using a compressed gas. For small engine charges, a compressed gas is used, with the compressed gas being derived solely from the chamber or the housing of the cylinder of the engine, and for high engine charges, another compressed gas is used derived from a source outside the cylinder. The source outside the chamber may include a mechanical compressor driven by one of a two-stage engine or a turbocompressor.

Abstract: In a method and device for feeding fuel into a combustion chamber of a cylinder of an internal combustion engine the following steps are discerned to withdraw a small amount of compressed hot gas via a valve opening into the combustion chamber of the cylinder during one working cycle, to store this small amount of hot gas withdrawn, in a valve chamber of the valve, to inject fuel into this valve chamber containing the small amount of hot gas, building a fuel-gas mixture, and to inject the fuel-gas mixture through the valve opening into the combustion chamber of the cylinder during next working cycle of the internal combustion engine.

Abstract: A fuel air injection system for a two cycle crankcase compression internal combustion engine wherein a pressure accumulator is provided in the injector and the accumulator is charged with a compressed charge from the combustion chamber into which the injector injects during a phase of operation. In one embodiment of the invention, the accumulator chamber is charged during a compression stroke when ignition does not occur and in another embodiment of the invention, the accumulator chamber is charged during the same stroke of the engine when ignition occurs.

Abstract: A hydraulically operated valve with controlled lift, in particular a fuel/gas injection valve for internal combustion engines, has a stop face fixed on the valve stem. For accurate control of the opening of the valve a stop cam is provided, which is drivn mechanically via a friction clutch, and which cooperates with the stop face. By rotating the cam through a predetermined angle the maximum valve lift will be obtained. The cam may be brought into contact with the stop face even in the closed position of the valve.

Abstract: Scavenging a cylinder of an engine with fuel-free fresh air and injection with atomized liquid fuel by a pressurized gas are accomplished independently, at specific moments during by the operating cycle of the engine. The fuel is atomized and injected into the cylinder by gases tapped from cylinder of the engine. The injection device can comprise a reservoir in which the gases tapped from cylinder are stored. The gases can be tapped from cylinder by a pneumatic injector when the valve opens.

Abstract: For control of the injection rate of a device for feeding fuel into the combustion chamber of an internal combustion engine, comprising an injection valve opening into the combustion chamber, which is used for taking compressed gas from the cylinder and injecting it together with the fuel supplied by a metering device, and further comprising a gas storage cell for holding the compressed gas, the proposal is put forward that a variable throttle be provided between the valve seat of the injection valve and the gas storage cell, whose flow cross-section can be controlled in accordance with load and speed parameters of the engine.

Abstract: In a method and device for feeding fuel into a combustion chamber of a cylinder of an internal combustion engine the following steps are discerned to withdraw a small amount of compressed hot gas via a valve opening into the combustion chamber of the cylinder during one working cycle, to store this small amount of hot gas withdrawn, in a valve chamber of the valve, to inject fuel into this valve chamber containing the small amount of hot gas, building a fuel-gas mixture, and to inject the fuel-gas mixture through the valve opening into the combustion chamber of the cylinder during next working cycle of the internal combustion engine.

Abstract: A device for introducing fuel into the head space of cylinder of non-premixed charge (diesel) engines is disclosed, which distributes fuel in atomized form in a plume, whose fluid dynamic properties are such that the compression heated air in the cylinder head space is entrained into the interior of the plume where it is mixed with and ignites the fuel in the plume interior, to thereby control combustion, particularly by use of a multiplicity of individually controllable devices per cylinder.

Abstract: The invention provides an internal combustion engine comprising a cylinder, a piston reciprocal in the cylinder, an accumulation chamber, a supply conduit including a check valve and extending between the cylinder and the accumulation chamber, a supply valve having a valve head located between the cylinder and the check valve and operable between an open position and a closed position to control gas flow from the cylinder through the supply conduit to the accumulation chamber, and an arrangement responsive to the pressure in the accumulation chamber and in the cylinder for selectively moving the supply valve relative to the open position and the closed position.

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: The delivery of fuel into the combustion chamber of a diesel engine is aided by blowing in an amount of compressed air which is small compared to the stroke volume of the diesel engine after the stream of fuel has been injected into the combustion chamber via the fuel nozzle. In this way fuel particles which would otherwise remain in the injection nozzle and considerably increase the hydrocarbon content of the exhaust are removed from the nozzle and burned, at the same time clearing the nozzle holes of any remaining fuel. The compressed air blown in after fuel injection will assist combustion of the red-hot particles of the fuel stream which have formed immediately beyond the nozzle.

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: The delivery of fuel into the combustion chamber of a diesel engine is aided by blowing in an amount of compressed air which is small compared to the stroke volume of the diesel engine after the stream of fuel has been injected into the combustion chamber via the fuel nozzle. In this way fuel particles which would otherwise remain in the injection nozzle and considerably increase the hydrocarbon content of the exhaust are removed from the nozzle and burned, at the same time clearing the nozzle holes of any remaining fuel. The compressed air blown in after fuel injection will assist combustion of the red-hot particles of the fuel stream which have formed immediately beyond the nozzle.

Abstract: A pneumatic direct cylinder fuel injection system for an internal combustion engine includes a pneumatic injector for each cylinder so as to supply a pressurized air/fuel charge to an associate stratified charge chamber forming a part of the associate combustion chamber preferably during the compression stroke of the associate piston, the quantity of fuel being supplied by an electromagnetic fuel injector. The pressurized air for the system can be supplied by an electrical or engine driven air pump or preferably the engine itself can be used as an air compressor with each cylinder having an air source control valve operatively associated therewith to control the flow of pressurized air during the compression stroke of the piston in its associate cylinder.

Abstract: Disclosed herein is an internal combustion engine comprising a plurality of cylinders respectively including a head end, an exhaust port, and a pressure port located between the head end and the exhaust port, a like plurality of pistons respectively movable in the cylinders through respective compression strokes, a like plurality of fuel injectors respectively connected to the cylinders and operative to supply, from a fuel source to each of the cylinders, a metered quantity of fuel conveyed by compressed gas in response to fuel injector operation during the compression stroke of the associated cylinder, a storage tank for accumulating and storing compressed gas, a duct system including a selector value for selectively connecting the pressure ports to the storage tank only during the compression strokes of the associated cylinders, and a conduit connecting the storage tank to the fuel injectors for supplying the fuel injectors with compressed gas in response to fuel injector operation.

Abstract: A fuel injection apparatus for an internal combustion engine comprising a metering device to adjust the quantity of fuel delivered each cycle of the device in response to conditions in the engine induction passage, a control activating said device to effect a base number of fuel delivery cycles to the engine, and a sensor responsive to transient engine conditions to increase the number of cycles of the metering device above the base number per engine revolution.

Abstract: A device and method are provided for the pneumatic injection of fuel into an engine. The device comprises at least one auxiliary duct having two ends one of which is connected to an exhaust pipe and the other to an injection member.

Abstract: A nozzle for the air injection of fuel into the combustion chamber of a diesel engine cylinder. Included is a plunger reciprocably mounted in a nozzle body to define an air chamber for receiving compressed air from the combustion chamber during the compression stroke of the piston in the engine cylinder. Formed integral with the plunger, a needle valve defines within the nozzle body a fuel chamber for receiving fuel to be injected. A nozzle tip secured to the nozzle body founds a premixing chamber open directly to the combustion chamber and further in communication with both air chamber and fuel chamber. Thus, upon descent of the plunger at the end of the compression stroke, the fuel from the fuel chamber is intimately premixed in the premixing chamber with the compressed air from the air chamber, prior to introduction into the combustion chamber.