Abstract: An internal combustion engine piston having a combustion bowl with fuel control structure for redirecting at least a portion of the fuel exiting the combustion bowl. One form of the piston includes a sharp edge disposed at the outer surface of the piston adjacent the entrance to the combustion bowl and a rounded fuel receiving lip located within the combustion bowl.

Abstract: A direct fuel injection internal combustion engine comprises a combustion chamber, a fuel injection valve and a spark plug. The combustion chamber has a piston including an outer cavity located in a top surface of the piston and an inner cavity located in the outer cavity. The outer and inner cavities are substantially axially symmetrical about the reciprocation axis of the piston. The fuel injection valve is arranged adjacent the reciprocation axis of the piston to inject a fuel stream directly into the combustion chamber. The spark plug is arranged adjacent the reciprocation axis of the piston to ignite a fuel-air mixture inside the combustion chamber. The direct fuel injection internal combustion engine further comprises a control unit configured to vary at least one of frequency and start timings of the fuel injection valve based on an engine operating condition.

Abstract: A valve system for an engine is provided. The valve system includes a cylinder head that defines an intake passageway, an exhaust passageway, and an auxiliary passageway. The auxiliary passageway includes a first connection with the intake passageway and a second connection with the exhaust passageway. A control valve is disposed in the auxiliary passageway. The control valve is moveable between a first position where the control valve blocks the first connection between the auxiliary passageway and the intake passageway and a second position where control valve blocks the second connection between the auxiliary passageway and the exhaust passageway.

Abstract: A combustion chamber assembly for use in a diesel engine includes a combustion chamber defined in a crown of a piston, the combustion chamber having a center portion, the center portion being defined at least in part by a portion of a convex sphere, the sphere having a radius and an origin, the origin of the radius lying on a piston central axis and the combustion chamber further having an outwardly radially disposed bottom margin, the bottom margin being defined in part by a portion of an annulus, the annulus having a radius and an origin. The combustion chamber further has a plurality of curved surfaces having smooth transitions between adjacent smooth surfaces, the smooth surfaces including the spherical center portion and the annular bottom margin. A piston incorporating the aforementioned combustion chamber and a method of forming the combustion chamber are further included.

Abstract: A spark ignition internal combustion engine (1), in particular an Otto-cycle gas engine, with at least one ignition device (14) per cylinder (2), wherein at least one piston (4) has a recess (8) in the piston head and wherein the recess (8) in plan view on to the piston head is of a substantially heart-shaped shape which differs at least in a region-wise manner from a circular shape, wherein the shape of the recess (8) in a plan view on to the piston head has precisely one axis of symmetry (10).

Abstract: An apparatus and method for improving efficiency of combustion engines. At least two combustion chambers are provided by contouring the surface of a piston or a cylinder head or a combination thereof. Such a contoured piston or cylinder head controls the peak temperature and pressure in order to combust the mixture efficiently, to increase power generated, and to decrease the amount of unused mixture exhausted from the combustion chamber. With the ability to control the peak pressure, the ignition plug can be fired at advanced ignition timing, thereby extending its life. The chambers are also designed to control flame propagation speed to reduce knock. Additionally, the chambers can also decrease the amount of pollutants such as NOx produced during combustion.

Abstract: A piston for an internal combustion engine is provided which has at a top surface thereof a cavity for causing a mixture charge drawn from an intake port into a combustion chamber so as to flow with a rotational motion about a horizontal axis to flow toward a spark plug. A combustion chamber structure for an internal combustion engine is also provided.

Abstract: A direct fuel injection internal combustion engine comprises a combustion chamber, a fuel injection valve and a spark plug. The combustion chamber has a piston including an outer cavity located in a top surface of the piston and an inner cavity located in the outer cavity. The outer and inner cavities are substantially axially symmetrical about the reciprocation axis of the piston. The fuel injection valve is arranged adjacent the reciprocation axis of the piston to inject a fuel stream directly into the combustion chamber. The spark plug is arranged adjacent the reciprocation axis of the piston to ignite a fuel-air mixture inside the combustion chamber. The direct fuel injection internal combustion engine further comprises a control unit configured to vary at least one of frequency and start timings of the fuel injection valve based on an engine operating condition.

Abstract: A combustion chamber assembly (and a piston having the combustion chamber assembly) for use in a diesel engine, includes a combustion chamber being defined in a crown of a piston, the combustion chamber having a central axis, and having a center portion being raised above a bottom plane of the combustion chamber. The center portion of the combustion chamber is defined in part by a portion of a sphere, the sphere having a radius, the origin of the radius lying on the combustion chamber central axis. The combustion chamber has a plurality of curved surfaces having smooth tangential transitions between adjacent smooth surfaces, the smooth surfaces including the spherical center portion in combination with a plurality of annular surfaces. A method of forming a combustion chamber is also included.

Abstract: A direct-injection spark-ignited engine is provided that includes a combustion chamber formed between a lower surface of a cylinder head and an upper surface of a piston. An intake and an exhaust valve are respectively disposed in an intake port and an exhaust port. These ports are respectively disposed on each side of the cylinder head. A spark plug is disposed in the cylinder head. A fuel injector directly injects fuel into the combustion chamber. A bowl is formed in the upper surface of the piston for generating a turbulent air flow.

Abstract: A combustion chamber assembly for use in a diesel engine includes a combustion chamber being defined in a crown of a piston, the combustion chamber having a center portion, the center portion being defined at least in part by a portion of a convex sphere to define a post, the sphere having a radius and an origin, the origin of the radius lying on a combustion chamber central axis and the combustion chamber further having an outwardly radially disposed bottom margin, the bottom margin being defined in part by a portion of a sphere, the sphere being concave and having an origin and a radius. The combustion chamber has more than two spherical surfaces having smooth annular transitions between adjacent spherical surfaces, the spherical surfaces including the spherical center portion and the spherical bottom margin. A piston and a method of forming a combustion chamber are further included.

Abstract: A combustion chamber assembly for use in a diesel engine includes a combustion chamber defined in a crown of a piston, the combustion chamber having a center portion, the center portion being defined at least in part by a portion of a convex sphere, the sphere having a radius and an origin, the origin of the radius lying on a piston central axis and the combustion chamber further having an outwardly radially disposed bottom margin, the bottom margin being defined in part by a portion of an annulus, the annulus having a radius and an origin. The combustion chamber further has a plurality of curved surfaces having smooth transitions between adjacent smooth surfaces, the smooth surfaces including the spherical center portion and the annular bottom margin. A piston incorporating the aforementioned combustion chamber and a method of forming the combustion chamber are further included.

Abstract: A multizone combustion chamber and method of combustion in a compression-ignited reciprocating engine. The combustion chamber includes a cylinder, a cylinder head located at one end of the cylinder, a piston that reciprocates in the cylinder, an inlet that supplies a gas into the combustion chamber during an induction stroke of the piston, and an injector that supplies a fuel into the combustion chamber. The combustion chamber defines a primary chamber and at least a secondary chamber when the piston is located in a predetermined position near the cylinder head. Combustion is initiated in the primary chamber while preventing combustion from occurring in the secondary chamber. Combustion in the secondary chamber is delayed until after the piston and the cylinder head have been separated and thermodynamic communication between the fuel/gas mass in the primary chamber and the fuel/gas mass in the secondary chamber is possible.

Abstract: Internal combustion engines have been developed having regeneration mechanisms for increasing efficiency and reducing emissions. Previous regeneration mechanisms have been complicated and costly. The present invention provides a simple regeneration member which is attached within a piston assembly. Thus the apparatus for attaching the regeneration member within the internal combustion engine greatly reduces the cost of the engine.

Abstract: An apparatus and method for improving efficiency of combustion engines. At least two combustion chambers are provided by contouring the surface of a piston or a cylinder head or a combination thereof. Such a contoured piston or cylinder head controls the peak temperature and pressure in order to combust the mixture efficiently, to increase power generated, and to decrease the amount of unused mixture exhausted from the combustion chamber. With the ability to control the peak pressure, the ignition plug can be fired at advanced ignition timing, thereby extending its life. The chambers are also designed to control flame propagation speed to reduce knock. Additionally, the chambers can also decrease the amount of pollutants such as NOx produced during combustion.

Abstract: A multizone combustion chamber and method of combustion in a compression-ignited reciprocating engine. The combustion chamber includes a cylinder, a cylinder head located at one end of the cylinder, a piston that reciprocates in the cylinder, an inlet that supplies a gas into the combustion chamber during an induction stroke of the piston, and an injector that supplies a fuel into the combustion chamber. The combustion chamber defines a primary chamber and at least a secondary chamber when the piston is located in a predetermined position near the cylinder head. Combustion is initiated in the primary chamber while preventing combustion from occurring in the secondary chamber. Combustion in the secondary chamber is delayed until after the piston and the cylinder head have been separated and thermodynamic communication between the fuel/gas mass in the primary chamber and the fuel/gas mass in the secondary chamber is possible.

Abstract: A combustion chamber assembly (and a piston having the combustion chamber assembly) for use in a diesel engine, includes a combustion chamber being defined in a crown of a piston, the combustion chamber having a central axis, and having a center portion being raised above a bottom plane of the combustion chamber. The center portion of the combustion chamber is defined in part by a portion of a sphere, the sphere having a radius, the origin of the radius lying on the combustion chamber central axis. The combustion chamber has a plurality of curved surfaces having smooth tangential transitions between adjacent smooth surfaces, the smooth surfaces including the spherical center portion in combination with a plurality of annular surfaces. A method of forming a combustion chamber is also included.

Abstract: A method for operating a reciprocating-piston internal combustion engine, having an injector nozzle operable by a single valve element and configured to directly inject a fuel into a combustion chamber and having a piston including a piston crown and a piston recess, includes the steps of injecting the fuel by the injector nozzle into the combustion chamber in the form of separated jets of the fuel having different inclinations relative to a top surface of the piston crown and selectively setting the inclinations of the fuel jets depending on an engine load.

Abstract: In an internal combustion engine having multiple cylinders, each cylinder defining a cylinder wall, and having a cylinder head, there being a piston movable axially within each cylinder to define a combustion zone between the piston top and the cylinder head, each cylinder having intake porting, the combustion comprising a manifold for delivering air to said combustion zones, via the intake porting at each cylinder, the manifold including air induction ducts, which are configured with branching to deliver substantially the same quantity of gas to each said porting.

Abstract: The present invention relates to a working cycle for a heat engine, especially of the reciprocating piston type, having a gas as working medium, including the steps of isentropic compression of the gas, isochoric addition of heat to the gas, isentropic expansion of the gas, and isochoric return of the gas to its initial condition. The invention is characterized in that the gas, before or during the compression, is divided into two portions, that the gas portions are compressed to different degrees, that heat is added only or mainly to the gas portion compressed to the lowest degree, and that the two gas portions are brought into connection with each other and are expanded together.

Abstract: Internal combustion engine with fuel injection directly into the combustion chamber of the engine. The engine has inlet channels, the angle of incidence (valve angle) (&agr;) of which is greater than 20° relative to the longitudinal axis of the cylinder chamber. The piston tops are made, firstly, with a surface portion inclined relative to a plane normal to the longitudinal axis of the cylinder chamber by an angle (&ggr;) equal to or less than the angle of incidence of the inlet channel, and, secondly, with a cavity connected to the inclined surface portion. By interaction between the angle of incidence of the inlet channels and the shape of the piston tops, there is generated in the combustion chambers a primary vortical movement in the inlet air about an axis perpendicular to the longitudinal axis of the cylinder chamber. The primary vortical movement generates a secondary vortical movement in the opposite direction in the piston cavity.

Abstract: An improved combustion chamber configuration for a direct injected internal combustion engine. The cylinder head recess and piston head are configured so as to provide a small clearance volume and accordingly high compression ratios while the shape of the piston head and the arrangement of the cylinder head recess permits a portion of the injected fuel to be directed toward the exhaust valves to cool them and reduce smoke and increase fuel efficiency.

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 diesel cycle, direct injected internal combustion engine is provided with a piston recess or bowl into which fuel is injected each combustion cycle. One or more reaction chambers adjacent the piston recess are in communication with the recess through an array of discrete orifices located along the side wall of the recess. Partial reaction of fuel and air in the reaction chambers each combustion cycle produces radicals including intermediate species for seeding a fuel air mixture of a following combustion cycle through a delayed discharge of radicals from the reaction chamber into the piston recess. The discrete orifices are arranged in a specific array that ensures a desired chaotic flow in the reaction chambers and maximum interaction between radicals discharged from the reaction chamber and the soot cloud formed in the combustion chamber upon ignition of the fuel air mixture in the piston recess.

Abstract: A direct-injection diesel engine in which a shallow-dish type piston cavity is formed on a top surface of a piston; wherein in the vicinity of the top dead center, a squish area is defined mainly by the top surface of the piston and an inner surface of a cylinder head opposite the top surface; when a velocity of a reverse squish flow from the shallow-dish type piston cavity to the squish area, generated due to a movement of the piston and is represented by Vs, and a fuel spray velocity in the vicinity of a lip portion of the shallow-dish type piston cavity is represented by Vsp, the distance between opposite wall portions of the shallow-dish type piston cavity is set such that the ratio Vs/Vsp is not greater than 1.25; and the squish area constitutes a part of the combustion chamber.

Abstract: A piston for an internal combustion engine has a re-entrant type combustion bowl. The combustion bowl has two re-entrant volumes in fluid communication and cascaded with respect to the longitudinal axis of the piston. The cascaded re-entrant volumes enhance gas velocities within the combustion bowl to improve fuel combustion.

Abstract: A piston which has a diameter of about 70 to about 100 mm and which is preferably produced with a resistant, malleable alloy having low density (lower than about 3 g/cm.sup.3) and mechanical properties at high temperatures such that a yield stress greater than about 120 Mpa at temperatures of the order of 300.degree. C. to 350.degree. C. is obtained. In the preferred embodiment, the piston is a single piece piston, comprising a head portion of diameter D ranging from about 70 to about 100 mm and a skirt portion downwardly projected from the head portion and inside which is provided a pair of wrist pin bosses, each having a hole with a diameter d and axial extension L for bearing the articulating wrist pin of the piston.

Abstract: A direct injected, internal combustion engine combustion chamber configuration that employs a three intake valves per cylinder and direct cylinder injection. Stratification is accomplished by providing a piston bowl and air flow pattern within the combustion chamber through intake passage shape and squish action. The shape of the combustion chamber also provides rapid flame propagation even at low speeds and loads.

Abstract: A spark-ignition type engine comprising a spark plug arranged at the center of the inner wall of the cylinder head and a fuel injector arranged at the periphery of the inner wall of the cylinder head. A cavity extending from a position beneath the fuel injector to a position beneath the spark plug is formed on the top face of the piston. The circumferential wall of the cavity extends archwise below the spark plug and has an arc shaped cross section.

Abstract: An internal combustion engine having a combustion chamber divided into two regions by an arcuate barrier on the top of the piston and a complementary arcuate barrier formed in a cavity of the cylinder head. When the piston is at top dead center, the combustion chamber is effectively divided into two portions with approximately ten percent of the chamber being in the vicinity of a fuel injector and a spark plug. By this structure, the engine minimizes the amount of fuel used at idle and at very low power levels, and yet engine performance at higher power levels is not affected.

Abstract: A piston having an offset piston bowl for use in an engine having a correspondingly offset fuel injector, wherein the piston bowl has a non-circular or non-annular shape. The non-annular bowl shape is contoured to permit increased spray plume length, avoiding impingement. The bowl is especially useful in a diesel engine having two-valves per cylinder, wherein the injector must be mounted in an offset location because a central region of the cylinder head is occupied by two proximal valve ports. The bowl has a raised inner portion surrounded by a concave outer portion. A peak or apex of the raised inner portion is located closer to a peripheral wall of the concave outer portion at a "short" side of the bowl than at a "long" side of the bowl.

Abstract: A combustion process is described, suitable for use in piston internal combustion engines, wherein two separate mixtures are used, one fuel leaner and one fuel richer than the minimum ignition delay mixture ratio. When the richer mixture is injected into the leaner mixture, interdiffusion creates zones readily compression ignitable. Burning is thusly initiated, which subsequently completes the combustion of the combined air fuel mixture. Very fuel lean overall mixture ratios can be utilized in this way to reduce undesirable exhaust emissions and to increase engine efficiency.

Abstract: The present invention relates to an applied ignition internal combustion engine having at least one cylinder in which a piston slides along the cylinder axis, with a cylinder head capping the cylinder and, together with the piston and cylinder, defining a combustion chamber. The piston has a recess open toward the cylinder head, the recess having several shapes of an ellipsoid section along a transverse plane of the piston, of which the main axis and generatrices are substantially parallel to the lengthwise axis of the piston in order to reduce the area-volume ratios in the combustion chamber and increase turbulence levels at the end of the compression cycle. The ellipse or ellipses is or are such that:1) 0<.lambda.<0.6 with ##EQU1## where G.sub.R is the major radius of at least one of the spaces P.sub.R is the minor radius of the space or spaces.

Abstract: A combustion chamber for a direct injected, reciprocating piston diesel cycle internal combustion engine in which fuel is injected into a piston recess and wherein the piston includes a reaction chamber adjacent the piston recess that communicates with the combustion chamber through a discrete orifice, wherein the orifice is located so as to discharge reaction products from the reaction chamber into the central portion of a soot cloud that is formed during combustion of fuel each combustion cycle.

Abstract: To accelerate a combustion within an entire combustion chamber including the vicinity of an opening portion for air suction to thereby make uniform a flame propagation in a combustion chamber structure for an internal combustion engine, and to provide a technology for preventing the generation of knocks, a longitudinal sectional shape of a top wall surface of the combustion chamber is in the form of a substantially triangular shape in longitudinal section defined and surrounded by a cylinder head, a cylinder and a piston. A projection is provided on a circumferential edge portion of a top surface of the piston, with a surface, facing the top wall surface of the combustion chamber, of the projection being substantially in parallel with the top wall surface of the combustion chamber. A cutaway portion is formed in the vicinity of at least a portion, facing the intake opening portion, of the projection of the top surface of the piston.

Abstract: An internal combustion engine having a cylinder head body with a pentroof-shaped combustion chamber comprises a piston including a piston cavity and a circular protrusion provided around the piston cavity, a fuel injector for injecting fuel downward to the piston cavity and a spark plug provided in proximity to an intake valve. Fuel is injected in a shape of a hollow cone and collides against the piston cavity and is diffused The diffused fuel is carried on the tumble flow of intake air and gathers around the electrode of the spark plug, this contributing to securing a stable stratified charge combustion. Further, the configuration of the circular protrusion prevents the sprayed fuel from scattering towards the cylinder wall.

Abstract: A piston for an internal combustion engine includes an insert defining an air chamber opening into the combustion chamber. The insert is preformed to a desired configuration and the piston cast around the insert thus securing the insert within the structure of the piston. The insert may be located wholly within the piston or may have a flange part which extends over an outer surface of the piston.

Abstract: A cast piston which includes a metal insert and a combustion bowl, with the metal insert defining a sharp undercut structure at an upper portion of the combustion bowl. The sharp undercut structure of the insert contains combustible gases and helps improve emissions. The metal insert also strengthens the head of the piston. The cast piston is fabricated by positioning the metal insert in a casting mold and casting a piston in the mold. The final shape of the combustion bowl is produced by a machining process which forms the sharp undercut structure on the insert.

Abstract: The combustion chamber structure having a combustion chamber almost at the center of the piston is installed in a cavity formed in the piston body with a heat insulating layer interposed therebetween. The combustion chamber structure and the piston body are joined by a joining member. The combustion chamber structure is formed with a nozzle insertion hole and communication holes. The joining member is made of a material with a thermal expansion coefficient intermediate between those of the piston body and the combustion chamber structure, or of almost the same kind of material as the piston body. Alternatively, the combustion chamber structure forms a piston head portion and the piston body forms a piston skirt portion. The lower surface of the piston head portion is formed as a tapered surface that is inclined toward the periphery. The upper surface of the piston skirt portion is also formed as a tapered surface that extends along the opposing tapered surface of the piston head portion.

Abstract: Piston with a reinforcing insert, presenting a top face (11) with a recessed combustion chamber (12) provided with a lateral peripheral wall, defined by the annular insert (20), which presents an internal end face (24) with a radial extension (d.sub.1) that is substantially smaller than the radial extension (d.sub.2) of the opposite external end face (22) of the annular insert (20). The radial thickness of the insert (20) varies along the profile of its external peripheral face (23), in order to maintain a value necessary to meet the requirements of structural reinforcement of the piston (10), at the region where the insert (20) is applied.

Abstract: There is provided a compression ignition type gasoline engine operable under a stable lean burn condition with a high compression ratio, and which has a simple construction without using a pre-heating system for an air-fuel mixture. An intake port communicates with a combustion chamber via an opening. The opening is closed by an intake valve. A fuel injection valve is provided in the intake port so as to inject an amount of gasoline inside the intake port within a duration in which the opening is substantially closed by the intake valve. Heat is generated in the mixture in the combustion chamber by means of a high compression ratio so that the mixture is self-ignited only by heat generated by compression. The compression ratio ranges from about 14 to about 20.

Abstract: When viewing in parallel to a cylinder center axis (3), a combustion expanding gas injected from an injection hole (4) is adapted to form a pair of valve recesses (10), (11) located on the opposite sides of an injection axis (12) of the injection hole (4). A pair of valve recesses (10), (11) are formed concavely in a piston top surface (8) so as to be separately disposed on the opposite sides of the injection axis (12) of the injection hole (4). Respective swirl centers (14), (15) of a pair of swirling gas flows (6), (7) are located within the pair of valve recesses (10), (11).

Abstract: The lip of the combustion bowl of a piston for an internal combustion engine has different radii in different sections of the bowl. Most of the lip is sharp to reduce emissions. The part of the lip above the piston pin bore is less sharp to reduce the mechanical stresses that otherwise would accumulate there in a sharp lip, cracking the piston. The lip has a smooth transition between the two radii to avoid creating additional stress.

Abstract: This invention provides a pre-combustion chamber gas engine capable of being applied to a two-stroke gas engine using a natural gas as fuel. A gas fuel is supplied to precombustion chambers with communication ports, which allows communication between primary chambers and pre-combustion chambers, closed with control valves provided therein, and suction air is supplied to cylinders and compressed under a high pressure. Even when the suction air is compressed under a high pressure in the primary chambers, the self-ignition of gas fuel does not occur therein since a gas fuel does not exist therein, so that knocking does not occur. Each of the control valves provided in the communication ports is constructed so that a lift amount thereof can be varied by a controller.

Abstract: A piston for an internal combustion engine is provided with a reaction chamber for generating radical fuel species during a combustion cycle for use during the next succeeding combustion cycle. The reaction chamber is located adjacent a piston crown recess and is in communication with the main combustion chamber of the engine through discrete orifices that are intended to separately control the supply of fuel and air to the reaction chamber for fuel injected engines and to enhance reaction chamber function in fuel aspirating engines. The discrete fuel and air control orifices are particularly beneficial for use in high swirl, direct injected combustion chambers.

Abstract: A toroidal chamber in a piston communicating through an orifice at a top face of the piston located in an internal combustion system, such as a spark ignition engine or a compression ignition engine. The chamber arranged to receive a fuel/air mixture so that a flame front, propagated in a main combustion chamber outside the toroidal chamber reaches the toroidal chamber, the fuel in the toroidal chamber burns. The burning creates pressure in the chamber that exceeds the pressure in the main combustion chamber. The combustion gas of high pressure is jetted out of the toroidal chamber into the main combustion chamber. The high pressure combustion gas jet generates turbulence and mixing in the main combustion chamber, contributing to an improved combustion. Accordingly, the power output and the thermal efficiency of the internal combustion system is improved.

Abstract: A cylinder head, more preferably a piston, of an internal combustion engine is provided on its compression face with a substantially central bowl and an annular common squish jet pocket encircling and spaced radially from the bowl to define an annular lip separating the squish pocket from the bowl. A plurality of discrete squish jet channels are formed through the lip and connect the squish pocket with the bowl at locations circumferentially spaced about the bowl. Each of the channels is open to the compression face along its full length from an inlet end connected to the annular squish jet pocket to a discharge end opening into the bowl. The channels provide the main paths for fluid flow from the area on the compression face surrounding the bowl into the bowl and in particular from the annular pocket into the bowl.

Abstract: A projection positioned in the center of a concave section of a toroidal combustion chamber is divided into a section with a steep slope extending from the bottom to the head surface and a section with a gentle slope. The head surface is in the form of a flattened conical trapezoid. Because of its shape, the projection makes it possible for the air which is close to the center section to flow close to the surface of a side wall of the concave section. The air which had been at the center section is added to the amount of air supplied for combustion and is mixed with the fuel in the vicinity of the surface of the side wall of the concave section. By setting the angle at which the air flows along the side wall surface (re-entrant angle) in the combustion chamber, the flow of the air close to the side wall surface is made turbulent, which improves the agitation of the fuel.

Abstract: An opposed piston engine includes at least one pair of pistons synchronously reciprocatingly mounted in a hollow cylinder. At least one projection is formed on the face of one piston, while a corresponding recess is formed on the face of the other piston, the recess being dimensioned to at least partly and preferably substantially receive the projection in the recess, upon reciprocation of the pistons. The piston construction is particularly advantageous in opposed cylinder diesel engines, and can eliminate the need for a glow plug to initiate combustion in even a cold engine.

Abstract: To accelerate a combustion with an entire combustion chamber including the vicinity of an opening portion for air suction to thereby make uniform a flame propagation in a combustion chamber structure for an internal combustion engine, and to provide a technology for preventing the generation of knocks, a longitudinal sectional shape of a top wall surface of the combustion chamber is in the form of a substantially triangular shape in longitudinal section defined and surrounded by a cylinder head, a cylinder and a piston. A projection is provided on a circumferential edge portion of a top surface of the piston, with a surface, facing the top wall surface of the combustion chamber, of the projection being substantially in parallel with the top wall surface of the combustion chamber. A cutaway portion is formed in the vicinity of at least a portion, facing the intake opening portion, of the projection of the top surface of the piston.