Abstract: A direct injection gasoline engine includes at least one cylinder, a piston reciprocably mounted within the cylinder, a cylinder head closing the cylinder and at least one inlet port adapted to cause swirl of the inlet air in the cylinder substantially about the axis of the cylinder. The crown of the piston is provided with a recess which has a floor and a side wall and constitutes at least part of the combustion chamber. A spark plug extends close to or into the recess, at the top dead centre position of the piston, at a position adjacent to the side wall of the recess. A fuel injector is arranged to inject fuel into the recess and is situated adjacent the side wall of the recess. That portion of the side wall of the recess which is between the fuel injector and the spark plug is arcuate, when viewed in the axial direction of the cylinder.

Abstract: A direct injection internal combustion gasoline engine has a piston 4 which includes a first inclined surface 22 approximately parallel to an intake-side inclined surface 11a of a cylinder head and a second inclined surface 23 approximately parallel to an exhaust-side inclined surface 11b of the cylinder head. A cavity combustion chamber 12 is recessed in the first inclined surface. A pair of valve recesses 31, 32 is also recessed in the first inclined surface. An arcuate dam section 21a is formed along the periphery of the valve recesses with the first inclined surface.

Abstract: The piston 4 is one whose top part has a flat shape. Fuel is injected directly inside the cylinder 1 from the fuel injection valve 2. The tumble air flow control valve 7 adjusts the strength of the tumble air flow. The combustion pressure control section 110 of the control unit 100 varies the combustion pressure in accordance with the rotational speed of the engine while maintaining constant the opening angle of the tumble air flow adjustment valve 7. The TCV opening angle control section 120 varies the opening angle of the tumble air flow adjustment valve 7 in accordance with the rotational speed of the engine while maintaining constant the combustion pressure. The control is made by switching between the combustion pressure control section 110 and the TCV opening angle control section 120 depending on the rotational speed of the engine.

Abstract: An in-cylinder direct-injection spark-ignition engine using at least a homogeneous combustion mode and a stratified combustion mode and equipped with a pentroof combustion chamber head having first and second shallow-angled surfaces, comprises intake valves disposed in the first shallow-angled surface, exhaust valves disposed in the second shallow-angled surface. A pair of substantially straight intake ports are formed in the cylinder head. A tumble-and-swirl control valve is disposed in a first intake port of the substantially straight intake ports for adjusting the amount of intake air passing through the first intake port.

Abstract: In a diesel engine which conducts exhaust gas recirculation and low temperature pre-mixed combustion at a low compression ratio, an ambient temperature at initiation of combustion which is determined by a compression ratio and an intake gas temperature or engine load is determined to be in a low temperature region which is lower than a first target temperature T1 which supports pre-mixed combustion or not. When the ambient temperature at initiation of combustion is determined to be in a region that is lower than a first target temperature T1, a temperature increase control device is operated which increases the temperature of the operational gases in the cylinder so that the temperature at initiation of combustion exceeds a first target temperature. The main fuel injection timing is placed in the range of 5.degree.-20.degree. of the combustion top dead center so that the main combustion temperature is above a fixed value.

Abstract: In an internal combustion engine with at least one injection device per cylinder for direct fuel injection into a combustion chamber, the injector nozzle is located in a top surface of the combustion chamber, which is formed in the cylinder head. In order to reduce the build-up of deposits and carbon residues in the region where the injection device enters the combustion chamber, the area around the injector nozzle is configured as a flow-directing surface for a swirl and/or tumble flow.

Abstract: A direct-injection spark-ignition engine operable between a stratified charge combustion mode where fuel injection is executed on a compression stroke while introducing a vertical-vortex tumble flow to an induced air drawn into a combustion chamber through an intake port, and a homogeneous combustion mode where fuel-injection early in the intake stroke produces a homogeneous air-fuel mixture, comprises a cylinder block having a cylinder, a piston movable through a stroke in the cylinder and having a centrally-formed piston bowl cavity combustion chamber in its piston head, a cylinder head mounted on the cylinder block, a centrally-located spark plug, and a fuel injector valve provided nearby the intake valve for injecting fuel directly into the combustion chamber.

Abstract: A failure diagnosis apparatus for an internal combustion engine having an intake air swirl control valve, includes a broken wire detection unit, a target opening degree/actual opening degree deviation detection unit, an opening degree abnormally detection unit and a target opening degree execution abnormality detection unit. Outputs from these detection units are used to detect a failure of the swirl control valve which becomes a factor for inviting an aggravation of an operability such as a knocking etc.

Abstract: An internal combustion engine with spark ignition and a piston that includes a substantially U-shaped asymmetrical piston depression with a depression floor that tapers towards an edge of the piston and that changes in a continuously rising manner into a depression wall, and an expanding squeezing chamber, the arrangement being adapted to promoting a swirling rather than a turbulent flow of injected fuel.

Abstract: An engine cylinder system (1) is disclosed. The system (1) is comprised of at least one cylinder (2) capped with a cylinder head (4), combustion chamber (7), and piston (25). The cylinder head (4) is provided with inlet passages (11, 12) and exhaust passages (29, 30) in fluid communication with the combustion chamber (7) via openings (22, 23, 31, 32). The openings (22, 23) are provided on the head (4) diametrically opposite such that inlet gases (35, 36) can generate powerful turbulence within the chamber (7).

Abstract: A cylinder head for internal combustion engines, particularly diesel engines with direct fuel injection, which has two inlet valves per cylinder each including spin-inducing means for producing spin flow about the longitudinal axis of the associated cylinder. Having regard to the direction of spin, the leading inlet valve is provided with an eccentric, crescent-shaped chamfer facing in the general direction of spin flow, and the trailing inlet valve includes flow blocking means for preventing combustion air from exiting the trailing inlet valve in a direction opposite to the direction of spin flow.

Abstract: Fuel-air mixture is stabilized with respect to the neighboring area of an ignition plug without any effect on deflection of fuel spray due to the air flow (swirl/tumble) in a combustion chamber, and the deposition of fuel onto the side wall of a combustion chamber is reduced, leading to the prevention of smoke.To that end, a fuel injection apparatus includes a fuel injection valve having a nozzle opening to a combustion chamber and an ignition plug, in which the fuel injection valve forms a fuel spray having different. levels of average speed. The fuel injection valve forms a fuel spray having relatively high speed at least in a half way of a single cycle of a fuel injection, and after that, the fuel injection valve forms relatively low-speed fuel spray, and consequently, a fuel-air mixture including high-speed fuel spray is supplied to a neighboring area of the ignition plug.

Abstract: An internal combustion gasoline engine has an air intake assembly which introduces air through the cylinder head into the cylinder to generate swirl (horizontal vortex) flow (as opposed to tumble (vertical vortex) flow) for stratified charge combustion, and to generate tumble flow for homogeneous charge combustion. The piston includes a cavity combustion chamber at the top surface of the piston, the cavity combustion chamber having a round shape and an increasing cross sectional area as the top of the piston is approached. During stratified charge combustion, swirl flow is smoothly guided into the cavity combustion chamber and preserved with a sufficient intensity since the cavity combustion chamber is well sealed at its whole periphery. During homogeneous charge combustion, a tumble flow is formed inside the cylinder, and fuel injection is made in the intake stroke. Fuel supplied into the cavity combustion chamber is easily washed away by the tumble stream.

Abstract: A controller of a direct injection engine is basically provided with a swirl control valve arranged in an air intake port portion, a fuel injection valve and a variable fuel pressure regulator, further provided with means for controlling fuel pressure by the variable fuel pressure regulator, means for detecting operational conditions and means for detecting a combustion state, and still further provided with means for controlling a valve opening of the swirl control valve on the basis of the operational conditions and the combustion state.

Abstract: A direct fuel injection type internal combustion engine includes a combustion chamber formed by a cylinder head having a spark plug, a fuel injector and an air intake means with a swirl control valve, a cylinder wall, and a piston head having a vaporization portion. The upper surface of the piston head has a vaporization portion defined with a bottom surface formed with a predetermined depth and slant, an arc-shaped first wall connected to the bottom surface and formed to exhaust side, an arc-shaped second wall connected to the bottom surface and formed parallel to the first wall, a protrusion portion formed between the first wall and the second wall, and an arc-shaped third wall connected to the bottom surface and formed to an intake side.

Abstract: A direct-injection spark-ignition engine having engine cylinders bored in a cylinder block, and a cylinder head mounted on the cylinder block, comprises at least one intake port provided for each of the engine cylinders. The ratio V/A of a stroke volume V (cm.sup.3) per cylinder to a cross-sectional area A (cm.sup.2) is set within a predetermined range defined by 45.ltoreq.V/A.ltoreq.55, where the cross-sectional area A is a minimum cross-sectional area obtained when the at least one intake port is cut by a plane extending in a direction substantially normal to a stream line of intake air flowing through the intake port.

Abstract: In an internal combustion engine with spark ignition and one or more reciprocating pistons, with an ignition device positioned in a roof-shaped top face of the combustion chamber and at least one fuel delivery device for each cylinder for direct fuel delivery essentially in the direction of the ignition device, and with at least one intake port configured so as to generate a swirl movement, the piston exhibits an asymmetrically shaped piston recess whose walls are configured as arcuate flow guiding faces assisting the swirl movement of the cylinder charge. To obtain reliable ignition of the directly introduced fuel on the one hand and maximum liberty in designing the engine on the other hand, the proposal is put forward that the piston recess between opposite walls should essentially constitute an open channel of meander-shaped or S-shaped configuration in plan view, at least one end of the channel forming an inlet area into the recess, which starts at the piston rim.

Abstract: A direct cylinder injected internal combustion engine that is effective to provide a stratified stoichiometric mixture at the spark gap at the time of firing and also a homogenous mixture under high speed high load conditions. This is achieved without specially formed bowls in the head of the piston by creating tumble under low speed and lower load conditions and by spraying on the heads of the intake valves during high speed high load conditions to obtain a homogeneous mixture.

Abstract: An engine having an air intake passage for drawing air into a combustion chamber and an injecting device for injecting fuel into the combustion chamber. A mixture of air and fuel undergoes stratified charge combustion. Sensors detect the operating conditions of the engine, and a swirl control valve opens and closes the air intake passage to swirl the air-fuel mixture. An actuator drives the swirl control valve. A computer computes a target opening angle of the swirl control valve in response to the detected operating conditions. A controller controls the force of the swirl by controlling the actuator in accordance with the computed target opening angle. A detector detects fluctuation of engine rotation. A corrector corrects the target opening angle in response to the detected fluctuation of the engine rotation to improve the performance of the engine.

Abstract: A cylinder direct injection spark-ignition engine in which fuel is directly injected from a fuel injector into each cylinder. The engine has an intake system having two intake ports for each cylinder. A swirl control valve is movably disposed in a passage connected to one of the intake ports. The swirl control valve functions to regulate the intensity (a swirl ratio) of swirl to be generated in the cylinder. Sensors are provided to detect an engine operating condition representative of a stratified charge combustion region. Additionally, a controller is provided to control the swirl control valve so as to change the swirl ratio in accordance an engine speed of the engine, when the current engine operating condition is detected to correspond to the stratified charge combustion region.

Abstract: An internal combustion engine has a piston reciprocable in a cylinder toward and away from a combustion chamber. An intake valve admits air into the combustion chamber. An exhaust valve discharges products of combustion from the combustion chamber. A fuel injector is positioned to direct a plume of fuel into the combustion chamber along a path and in a direction to impinge upon the exhaust valve. The piston has an end face formed with a concave recess or pocket adjacent the exhaust valve. The exhaust valve is constructed and arranged to deflect fuel impinging thereon into the recess. The recess being shaped to redirect fuel back toward the path of the plume of fuel.

Abstract: In an internal combustion engine with spark ignition and one or more reciprocating pistons, with an ignition device and at least one fuel delivery device for each cylinder, and with a combustion chamber bounded by a roof-shaped top face, the surface of the piston top is provided with an unsymmetrical, arched flow guiding rib assisting the swirl movement of the cylinder charge. The flow guiding rib is configured as an integral part of the piston top surface, which largely conforms to the roof-shaped top of the combustion chamber, and includes an essentially centrically positioned combustion chamber recess with an entrance area in close proximity of the fuel delivery device.

Abstract: A combustion chamber of an in-cylinder direct fuel injection spark ignition engine having a pentroof composed of an intake side roof and an exhaust side roof, a piston, and a cylinder. The combustion chamber has a fuel injector provided between the intake side roof and the exhaust side roof inclined toward the exhaust side port, an intake port provided on the intake port side roof at an acute angle with respect to an extended line from the exhaust side roof so as to form a tumble flow of intake air along the exhaust side roof, a piston cavity with a curved surface formed on the top surface of the piston so as to reflect a fuel spray injected from the fuel injector together with that tumble flow in the direction of the intake side roof, and an electrode of a spark plug projected from the intake side roof so as just to collide with the tumble flow.

Abstract: The invention relates to a four-stroke internal combustion engine with spark ignition and direct injection of the fuel into the combustion chamber, with a reciprocating piston for each cylinder and a roof-shaped top of the combustion chamber with at least one exhaust valve and at least two intake valves, as well as intake ports generating a tumble flow in the combustion chamber, as well as a fuel injection device opening into the combustion chamber, and an ignition source located in the area of the cylinder axis in the roof of the combustion chamber.

Abstract: A multiple cylinder, multiple valve internal combustion engine having direct cylinder injection. The cylinder injectors are disposed on a longitudinally extending plane that contains the cylinder bore axis and are inclined at acute angles to planes perpendicular to the longitudinal plane and containing the cylinder bore axis. The spark plugs are located at the intersection of both planes and are inclined to the transverse plane similarly to the fuel injectors. An arrangement is disclosed for controlling the intake charge into the engine so as to be directed primarily on the side of the combustion chamber where the fuel injector injects under at least low speed, low load conditions.

Abstract: An internal combustion engine having a direct cylinder injection and including a variable valve timing mechanism for at least changing the time of closing of the intake valve. The fuel injection timing and intake valve closing timing are controlled so that under low and mid-range engine speeds, but high loads, the intake valve is closed before the piston reaches bottom dead center position on its intake stroke so as to reduce the effective compression ratio. The engine is provided with an injector location and piston with a bowl in its head that improves fuel stratification under at least some running conditions so as to permit lean burn operation. The intake valves are offset to one side of a plane containing the axis of the cylinder bore, and the fuel injector is disposed between a pair of intake ports and below them so as to direct its injection axis toward the exhaust side and toward the recess in the head of the piston.

Abstract: In a method of forming a fuel/air mixture in an internal combustion engine with direct fuel injection, wherein a combustion air flow is admitted to each cylinder through at least one intake passage tangentially to the cylinder wall such that a combustion air spin flow about the cylinder axis is formed in the combustion chamber and fuel is injected into the combustion chamber in a fuel beam extending along the cylinder axis, at least one additional fluid stream is added to the combustion air flow in the intake passage at the side of the intake passage opposite the direction of the spin flow in the combustion chamber so as to provide an additional spin impulse to the combustion air in the combustion chamber.

Abstract: An internal combustion engine defining a combustion chamber for the direct injection of fuel through a centrally located fuel injector and having a first inlet passage and port for directing hot exhaust gases of a recirculation medium to a central region of the combustion chamber and a second inlet passage and port for directing air tangentially into the combustion chamber to cause a circular flow about the chamber's periphery and about the exhaust rich central region. The injector sprays fuel through the hot exhaust gas medium in the central region which results in a pre-heating of the fuel which has been found to reduce hydrocarbon emissions prior to ignition by a spark plug located adjacent the periphery of the combustion chamber.

Abstract: An internal-combustion engine includes a cylinder, a piston reciprocating therein, intake and exhaust ports, a fuel injection nozzle opening into the combustion chamber of the cylinder and an ignition device situated in the top wall of the cylinder. The top wall of the cylinder as well as the piston base oriented towards the top wall each has first and second surfaces being inclined to one another and meeting in a ridge, whereby the top wall and the piston base have an essentially V-shaped configuration when viewed in a sectional plane taken along the cylinder axis. The first surface of the top wall faces and is parallel with the first surface of the piston base and the second surface of the top wall faces and is parallel with the second surface of the piston base. A dished depression is provided in the piston base such that the depression interrupts the ridge and extends on either side thereof, whereby the dished depression is bounded by the first and second surfaces of the piston base.

Abstract: A direct injection ignition engine includes a piston with a cavity on a top surface thereof, an injector arranged at a peripheral portion of a combustion chamber to be faced to the combustion chamber for injecting a fuel directly into the combustion chamber, an ignition plug arranged to be projected to the combustion chamber for igniting the fuel introduced into the combustion chamber, an intake passage connected to the combustion chamber for introducing an intake air to the combustion chamber, intake air flow control valve arranged in the intake passage for controlling an intake air flow of an inclined vortex including a tumble component and swirl component produced in the combustion chamber, an actuator for driving the control valve, engine load detecting sensor for detecting an engine load, engine speed detecting sensor for detecting an engine speed, fuel supply controller, based on the output signals from the engine load detecting sensor and the engine speed detecting sensor, for producing control signals

Abstract: Swirl strength is formed to be 1-3.5, and the fuel mist speed of the fuel to be injected into a combustion chamber is formed to be 5-37 m/s or 5-25 m/s, whereby the air fuel ratio (A/F) is used as the lean limitation. Further, a control apparatus determines a lean combustion region according to the swirl strength and the fuel mist speed. By paying using the injection speed of the fuel, the rich air-fuel mixture and the lean air-fuel mixture are stratified by the combination of the swirl shape (the swirl strength) and the fuel mist speed.

Abstract: A cylinder head for an in-cylinder injection spark-ignition type internal combustion engine is formed with an injection passage for providing communication between a fuel injection valve and a combustion chamber. The injection passage includes a first and second passage sections disposed on the fuel injection valve side and on the combustion chamber side. The first passage section is formed, for example, into a truncated cone shape or a right circular cylindrical shape so that the cross sectional area decreases toward the fuel injection valve side or the area is constant over its entire length. The second passage section is formed to have the cross sectional area which increases toward the combustion chamber side. The fuel injected from the fuel injection valve flows into the combustion chamber via the injection passage having a gradually increasing cross sectional area, so that turbulence of fuel spray due to sudden divergent flow does not occur, resulting in an improved fuel combustion efficiency.

Abstract: In order to optimize combustion in a four-stroke spark-ignition engine with direct fuel injection, the conditions of charge flow are improved by providing the top surface of each piston with an essentially U-shaped guiding rib, which is open towards the exhaust side of the combustion chamber, fuel injection taking place into the concave area inside the guiding rib. The nozzle opening of the fuel injection device as well as the ignition source are positioned in the area of the cylinder center, i.e., preferably on different sides of the longitudinal center plane of the engine.

Abstract: A direct-injection type spark-ignition internal combustion engine comprises a fuel-injection valve whose spray hole is inclined toward a piston crown, while an uppermost line of fuel spray injected through the spray hole is set at a lower level than electrodes of the spark plug and a lowermost line of the fuel spray is in spaced relationship with a cylinder inner wall close to the spray hole. The piston crown is formed with a recessed portion and a raised flat-surface portion to define a ridge line as an intersecting line between them. The ridge line is offset from a center axis of the cylinder by a predetermined distance toward the exhaust-valve port side. Preferably, a spray angle between the uppermost and lowermost lines is set within a predetermined angle range of 70.degree..+-.20.degree..

Abstract: A dual fuel injection arrangement for an internal combustion engine. Fuel is injected into the inlet manifold ducts to each engine cylinder via injectors. An arrangement of valves allows selected supply of either a first fuel or a second fuel to the injectors via inlet fuel rail and branch lines. Excess fuel is returned to each supply by way of return line (11). Electronic control units determine injection timing for the selected fuel dependent upon engine parameters for the first fuel and upon an adjusted timing for the second fuel where the adjustment takes account of the different characteristics of the second fuel compared with the first fuel. In particular there is disclosed an arrangement where the first fuel is gasoline and the second fuel is a liquified gas.

Abstract: A split cycle internal combustion engine having located wholly within the combustion chamber (13) of the firing cylinder (10) and spaced from the walls thereof a hollow dome (14) with the closed head of the dome (14) adjacent to the head (11) of the firing cylinder (10) and the open base of the dome (14) nearer to the power piston (12), a nozzle (24) directing air from a compressor around the interior wall of the dome (14), nozzle (24) directing fuel into the dome (14) after all the air has entered the dome (14) and a nozzle (25) for igniting the fuel/air mixture when the temperature of the dome (14) is insufficiently high for ignition. An inwardly directed flange (17) extends around the open base of the dome (14) to form a channel (18). It is preferred that the engine operates at very high pressures, the compressor is multi-stage.

Abstract: A diesel engine includes a variable swirl forming mechanism, an exhaust gas recirculation (EGR) control mechanism, and an injection timing control mechanism. The variable swirl forming mechanism forms strong, middle or weak air swirls in a combustion chamber according to engine loads and engine speeds. The EGR control mechanism recirculates a part of exhaust gas to the combustion chamber according to the engine loads and the engine speeds. The injection timing control mechanism advances or retards the injection timing according to the engine loads and the engine speeds.

Abstract: A diesel engine includes a variable swirl forming mechanism, an exhaust gas recirculation (EGR) control mechanism, and an injection timing control mechanism. The variable swirl forming mechanism forms strong, middle or weak air swirls in a combustion chamber according to engine loads and engine speeds. The EGR control mechanism recirculates a part of exhaust gas to the combustion chamber according to the engine loads and the engine speeds. The injection timing control mechanism advances or retards the injection timing according to the engine loads and the engine speeds.

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: Improved combustion chamber configurations for two-cycle engines with high pressure fuel injected systems having reciprocal pistons, cylinders with multiple injectors for each cylinder and a cylinder head liner with a chamber having a discoidal configuration that cooperates with a piston head structure to generate a toroidal, swirling, compressed air flow during compression strokes of the reciprocating piston.

Abstract: In order to reduce soot emissions from diesel engines, the necessary mixing of air and gasified fuel must be completed prior to the main combustion. On the other hand, noise is reduced to a minimum by providing that the pressure increase per degree of crankshaft rotation during combustion is no greater than the maximum pressure increase during the compression stroke.

Abstract: An internal combustion engine is designed to run on natural gas and utilize the diesel cycle. To promote combustion, a mixing chamber is dispersed within a combustion chamber formed between the piston and cylinder. The chamber includes a pair of concentric housings, the innermost of which receives fuel from the injector and provides a rich mixture in the volume between the housings.

Abstract: A combustion chamber defined by a recess formed in the top of a piston in the direction of the central axis thereof with its geometry being progressively enlarged in the direction of the recess. The intensities of swirl flow and squish flow are optimized by letting the two flows interact with each other in the upstream side so as to optimize the air flow in the combustion chamber overall. In the meantime, fuel is atomized and injected through a fuel injection nozzle means, which has five or more nozzle holes, toward the side wall of the combustion chamber so as to circumferentially divide the chamber by the fuel sprays into five or more approximately equal sections. Thus, uniform dispersion and distribution of fuel, together with the optimized flow of air, is achieved in the combustion chamber, whereby the air utilization rate is raised and the combustion unburnt particulate matters are decreased.

Abstract: A direct injection type Diesel engine comprising a combustion chamber having an inner wall surface formed at a piston head of a piston reciprocated in a cylinder of the Diesel engine, and a fuel injection nozzle means mounted to a cylinder head of the Diesel engine, said fuel injection nozzle means having a main nozzle hole and an auxiliary nozzle hole, wherein the main nozzle hole is closed under low load of the Diesel engine to allow fuel to be injected from the auxiliary nozzle hole only. A part of the fuel injected from the auxiliary nozzle hole is allowed to collide with the inner wall surface of the combustion chamber arranged adjacent thereto, or is allowed to collide with an inner wall surface of a passage formed at the cylinder head, which inner wall surface is connected to the inner wall surface of the combustion chamber, thereby to be atomized, while a residual part of the fuel is allowed to flow along the inner wall surface of the combustion chamber.

Abstract: Described herein is a combustion chamber for internal combustion engine, including a protuberance extending radially inward from a peripheral wall surface of a combustion chamber which is formed by hollowing the top of a piston in the axial direction thereof. The protuberance induces rolling streams turning in the same direction as the fuel swirl thereby collecting air and atomized fuel in a region on the upstream side of the protuberance. The rolling stream serves to improve the ignition quality by enriching the concentration of fuel vapors in that locality. The flames generated in the vicinity of the protuberance are propagated to the atomized fuel which is supplied to other regions of the combustion chamber, thereby providing an internal combustion engine with improved ignition and combustion qualities.

Abstract: An air-compressing reciprocating piston-equipped internal combustion engine comprises, in the frontal face of a piston head, a rotation-symmetrical cavity as a combustion chamber, a fuel-feeding unit generating a rotary motion of the air charge entering the cavity, and a fuel injection unit. The fuel injection unit is provided with an injection nozzle for injecting fuel directly into the cavity constituting the combustion chamber. In order to achieve a higher degree of efficiency, a decrease of the emission of polluting gases and of noise, as well as a relief of the mechanically highly stressed parts of the engine, the rotary motion of the air charge generated by the fuel-feeding unit is given a swirl number of about 1.5 to 2.5. Furthermore, the diameter (d) of the combustion chamber-constituting cavity is between about 55 to 75% of the diameter (D) of the cylinder, and finally, the fuel injection nozzle has at least four orifices.

Abstract: An air-compressing reciprocating piston-equipped internal combustion engine comprises, in a piston head of the piston, a cavity being axially symmetrical about a central cavity axis and constituting a combustion chamber, as well as a fuel injection nozzle for injecting fuel directly into the said cavity. The nozzle has a longitudinal nozzle axis which encloses with the central cavity axis an acute angle. In order to generate a rotary motion of an air charge fed into the said cavity, there is provided a correspondingly designed air-feeding unit.

Abstract: A direct injection type internal combustion engine has a piston reciprocatably fitted in the bore of a cylinder block defining a combustion chamber together with the cylinder block and a cylinder head. A main recess is formed in the combustion chamber for accelerating the swirl of intake air which is prepared and introduced by an intake device. At least one auxiliary recess is formed in the main recess and is arranged in the direction of the intake air swirl and in the direction of the fuel injection of a fuel injector for generating a secondary swirl different from the intake air swirl and for generating turbulence between the two swirls. Thus, the introduction of air into the fuel droplets fed from the fuel injector is promoted by the intake air swirl and the secondary swirl so that the combustion efficiency of the internal combustion engine is improved.

Abstract: A four-stroke piston engine in which air is drawn into a cylinder while rotary motion about the cylinder axis is imparted to the air. Fuel may be blown/injected into the air during its rotation in the cylinder while the fuel supply is located on the axis of the cylinder and supplies at least one jet of fuel directed radially outwardly and which jet of fuel in cooperation with the rotating air forms at least one helical stream of mixture within the cylinder, preferably during the compression stroke, which is transformed into a coherent mixture zone enclosed by a ring of air upon completion of compression. The piston may have a recess when the piston approaches top dead center so that an enriched zone is formed in the lower region of the compression space which can be ignited by electrodes disposed in said lower region of the compression space.

Abstract: Conventional direct injection internal combustion engines will not completely ignite and burn relatively lower-cetane-number fuels such as 100 percent methanol or ethanol because the fuel spray injection pattern usually cannot carry or propagate a flame to all the injected fuel which is typically made up of individual fuel streams which are separated by pockets of fuel-deficient intake air. The present fuel combustion system (10) includes a fuel ignition-initiating device (26) such as a glow plug (70) and apparatus (98,102) for interconnectedly contacting and continuously bridging all of the individual fuel streams (66) with an auxiliary cloud (94) of well-atomized fuel. In this manner, a flame initiated by the fuel ignition-initiating device (26) is rapidly and completely propagated via the auxiliary cloud (94) of fuel to all the individual fuel streams (66).