Abstract: In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the engine includes a lower cavity, an upper cavity, and a lip portion therebetween. A controller causes a main injection and at least one pilot injection to be executed when the engine operates in a first state and a second state in which the load is lower than the load in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller sets the timing of the pilot injection(s) so that the distribution ratio of the fuel spray of the pilot injection(s) for the lower cavity is higher when the engine operates in the first state than when in the second state.

Abstract: An object of the present invention is to, while forming a heat insulating layer on a squish area surface of a top surface of a piston main body, prevent generation of large cracks on the heat insulating layer and suppress damages and peeling of the heat insulating layer. To achieve this object, in the present invention, pressure is applied to a heat insulating layer provided on a top surface of a piston main body, that is, a pressing stress is applied to the heat insulating layer in advance.

Abstract: A piston structure for a four-stroke internal combustion engine is provided, enabling an increase in the intake efficiency and a favorable ignitability to improve the performance of the internal combustion engine. In a piston structure for a four-valve four-stroke internal combustion engine, a piston crown includes: an intake-side inclined flat surface formed in a single plane by bottom surfaces of a pair of intake valve recesses and an intake-side common flat surface; and an exhaust-side inclined flat surface formed in a single plane by bottom surfaces of a pair of exhaust valve recesses and an exhaust-side common flat surface. The intake-side inclined flat surface and the exhaust-side inclined flat surface are formed into a pent-roof shape with a ridge line at an intersection therebetween. The exhaust-side inclined flat surface extends into the intake valve recesses, and the ridge line is located on a side of the intake valve recesses.

Abstract: An internal combustion engine includes an engine block having a cylinder bore and a cylinder head having a flame deck surface disposed at one end of the cylinder bore. A piston connected to a rotatable crankshaft and configured to reciprocate within the cylinder bore has a piston crown portion facing the flame deck surface such that a combustion chamber is defined within the cylinder bore and between the piston crown and the flame deck surface. A fuel injector having a nozzle tip disposed in fluid communication with the combustion chamber has at least one nozzle opening configured to inject a fuel jet into the combustion chamber along a fuel jet centerline. At least one duct defined in the combustion chamber between the piston crown and the flame deck surface has a generally rectangular cross section and extends in a radial direction relative to the cylinder bore substantially along the fuel jet centerline.

Abstract: An internal combustion engine includes a combustion chamber defined by a cylinder, a piston defining a piston top, a cylinder head with an intake port and an exhaust port, and a corresponding intake valve and an exhaust valve. The internal combustion engine further includes an intake manifold for supplying air to the combustion chamber and an exhaust manifold for drawing exhaust gas from the combustion chamber. The flow dynamics of the internal combustion engine are improved by including textured surfaces on one or more of the piston top, the cylinder head, the intake valve, the intake port, the exhaust valve, the intake manifold, the exhaust manifold, or the fuel supplier. The textured surface may include indentations, protrusions, or combinations.

Abstract: A combustion chamber in an opposed-piston, internal-combustion engine is disclosed in which the pistons tops are designed so that when they approach each other, they induce a tumble flow in one or two hemispherical spaces defined in the piston tops. The combustion chamber further includes injectors side mounted in the cylinder wall. In one embodiment, the tumble flows in the two hemispheres are in the same direction and in another embodiment, in opposite directions. In yet another embodiment, there is only one injector and one hemisphere in which a tumble flow is induced.

Abstract: A combustion chamber structure for a direct injection diesel engine is provided which can increase recirculated amount of exhaust gas while avoiding generation of black smoke and deterioration of fuel efficiency as much as possible. Disclosed is a combustion chamber structure for a direct injection diesel engine having a cavity 10 on a top surface of a piston 9. The cavity is concave to provide a majority of the combustion chamber. Fuel is injected from a center of a cylinder top radially into an inner periphery of the cavity 10 to self-ignite. A depression 24 is formed at an outer periphery of the cavity 10 and is sunken relative to the top surface of the piston 9 to provide a step. The depression 24 has a bottom with an outer periphery gradually rising radially outwardly in modestly curved surface to the top surface of the piston 9.

Abstract: An apparatus and method for improving performance in an internal combustion engine includes texturing on an inner surface of at least a portion of an engine head. The texturing may include elongated raised portions extending in one or more directions that may aid in controlling and directing pre-combustion and/or combustion gases in a combustion chamber for a more unified combustion. The result is improved power and/or efficiency.

Abstract: An ignition-engine system for internal combustion engines having two-valves per cylinder (100) with a larger intake valve (103) and a smaller exhaust valve (104) in a longitudinal layout with a single camshaft (118) operating bucketed valve stems 103a and 104a that are vertical, with the valves making up essentially the roof of the combustion chamber and having a volume essentially under the intake valve of approximately 35% of the combustion chamber and a volume under the exhaust valve of approximately 65%, and two spark plugs per cylinder with plugs (102a) and (102b) located at the edge of two opposite squish-zones (105) of a compact combustion chamber, wherein the air-flow near TC is channeled between the two large squish-lands (101a) and (101b) wherein the cross-section of the channel is approximately constant of average width “W’, resulting in a relatively more compact combustion chamber having squish-lands take up approximately ? of the projected bore area of the cylinder and the more compact channel to

Abstract: In a direct fuel injection diesel engine having a piston with a pentroof-shaped top face, with regard to a pentroof-shaped piston (13) with a cavity (25) recessed in a central part of the top face, a radial width S of a squish area (26) formed between an outer peripheral part of the top face and a lower face of a cylinder head (14) changes in the circumferential direction of the piston (13). By setting a squish clearance H large for a portion where the radial width S of the squish area (26) is large and setting the squish clearance H small for a portion where the radial width S of the squish area (26) is small, more specifically, by setting S/H so that it is constant in the circumferential direction, it is possible to make the strength of the squish flow uniform in the circumferential direction of the piston, thus promoting the mixing of air and fuel and reducing harmful exhaust components.

Abstract: The present invention is directed to a piston arrangement with a unique bowl geometry for optimizing a two-stroke locomotive diesel engine having an exhaust gas recirculation (“EGR”) system. This piston arrangement achieves a reduced level of smoke and particulate matter; promotes the mixing process in the engine cylinder; and provides a lower compression ratio for reducing NOx emissions.

Abstract: A combustion chamber is provided within an internal combustion engine, the combustion chamber including a cylinder head having an internal bore with an open end and a closed end, and a piston which reciprocates within the internal bore between a TDC position near the closed end and a BDC position, with a compression end facing the closed end. Poppet valves on the closed end and ports on the internal bore can control the flow of gasses into, and from, the combustion chamber. The combustion chamber is stratified when the compression end is positioned within a stratified distance of the closed end. When stratified, the combustion chamber is comprised of a central combustion region, a perimeter squish region, and a transfer passage between the regions. A direct fuel injector injects fuel into the central combustion region, mixing fuel with inducted gasses prior to combustion. The combustion chamber can be thermally insulated.

Abstract: A two-stroke internal combustion engine which has an Inverted Cross-Scavenged operation forming a 180° air and exhaust gas loop and having two overhead valves [46, 47] in the cylinder head and optimized coils [43, 44] per spark plug [41, 42], the spark plugs being halo-disc type plugs, a central fuel-injector means [45], and the combustion chamber forming a Perfect Miller Cycle with an effective CR of approximately 10.5 to 1 and ER equal to approximately 18 to 1, and the valves opening at near bottom center (BC) and closing at approximately 75° after BC, and a quick response super-charger or turbo-charger located at the intake.

Abstract: An improved internal combustion engine is provided with at least one channel or groove on its compression face. The at least one channel or groove can be open and of uniform width. The channel or groove can direct flow of an air-fuel mixture to increase combustion efficiency.

Abstract: An ignition-engine system for internal combustion engines having two-valves per cylinder (100) with a larger intake valve (103) and a smaller exhaust valve (104) in a longitudinal layout with a single camshaft (118) operating bucketed valve stems 103a and 104a that are vertical, with the valves making up essentially the roof of the combustion chamber and having a volume essentially under the intake valve of approximately 35% of the combustion chamber and a volume under the exhaust valve of approximately 65%, and two spark plugs per cylinder with plugs (102a) and (102b) located at the edge of two opposite squish-zones (105) of a compact combustion chamber, wherein the air-flow near TC is channeled between the two large squish-lands (101a) and (101b) wherein the cross-section of the channel is approximately constant of average width “W’, resulting in a relatively more compact combustion chamber having squish-lands take up approximately ? of the projected bore area of the cylinder and the more compact channel to

Abstract: A reciprocating piston engine wherein the movement of a piston within the combustion chamber creates vortices in the fluid within the chamber and wherein the orientation of the vortices is more normal to the axis of movement of the piston than parallel to the axis of movement of the piston. The vortices may be created by a device for attachment to the crown of a piston or by the configuration of the crown of the piston. The vortices may be created by a plurality of vanes extending outwardly from the center of the piston to the periphery thereof.

Abstract: An internal combustion engine (300) for a vehicle, such as a motorcycle (20), includes a crankcase (380), two banks of cylinders (320a, 320b) projecting from the crankcase (380) in a V-configuration, a plurality of pushrods (364), and a plurality of camshafts (360a, 360b, 360c) supported by the crankcase (380). The two banks of cylinders (320a, 320b) include a first cylinder bank that projects from the crankcase (380) to a first cylinder head (340a), and a second cylinder bank that projects from the crankcase (380) to a second cylinder head (340b). The plurality of pushrods (364) extend between the crankcase (380) and the first and second cylinder heads (340a, 340b), and the plurality of camshafts include only the first, second and third camshafts (360a, 360b, 360c).

Abstract: An internal combustion engine has at least one cylinder, wherein in the cylinder there is a piston, which has a recess. Furthermore, the internal combustion engine has a cylinder head, which has the shape of a roof complementary to the roof-shaped geometry of the piston with a first and second side converging in the shape of a gable, with the piston and the cylinder head defining a top side and a bottom side of a combustion chamber. The internal combustion engine has an ignition device, which is arranged at least approximately in the center in the roof shape. The cylinder further has preferably two inlet valves, which are arranged in the first side, and also preferably two outlet valves, which are arranged in the second side. The recess extends past both sides, wherein the recess includes at the side approximately vertically descending sides and a base. The piston further has at least two, preferably four quench zones, which are at least partially separated from each other by valve pockets for valves.

Abstract: In a direct fuel injection diesel engine having a piston with a pentroof-shaped top face, with regard to a pentroof-shaped piston (13) with a cavity (25) recessed in a central part of the top face, a radial width S of a squish area (26) formed between an outer peripheral part of the top face and a lower face of a cylinder head (14) changes in the circumferential direction of the piston (13). By setting a squish clearance H large for a portion where the radial width S of the squish area (26) is large and setting the squish clearance H small for a portion where the radial width S of the squish area (26) is small, more specifically, by setting S/H so that it is constant in the circumferential direction, it is possible to make the strength of the squish flow uniform in the circumferential direction of the piston, thus promoting the mixing of air and fuel and reducing harmful exhaust components.

Abstract: An axial flow rotary valve for an engine, that is rotatable about an axis within the bore of a cylinder head. The valve communicating with a respective cylinder in which a piston reciprocates, and an ignition means associated with the cylinder. The valve is provided with inlet and exhaust peripheral openings that periodically communicate with cylinder through a window in the bore. A combustion chamber is formed in the space between the crown of the piston at top dead centre and the cylinder head and the valve. The ignition means comprising first and second spark plugs, each of said spark plugs having a nose located at one end thereof exposed to the combustion chamber, said noses being disposed on opposite sides of said window within the axial extremities of said window.

Abstract: A reciprocating piston engine wherein the movement of a piston within the combustion chamber creates vortices in the fluid within the chamber and wherein the orientation of the vortices is more normal to the axis of movement of the piston than parallel to the axis of movement of the piston. The vortices may be created by a device for attachment to the crown of a piston or by the configuration of the crown of the piston. The vortices may be created by a plurality of vanes extending outwardly from the center of the piston to the periphery thereof.

Abstract: A low geometric squish ratio piston for internal combustion engines to facilitate squish inducing mixing and intensified turbulence near engine top dead center The piston comprises a piston head having a height and a width and a depth with a top surface, and a skirt region with a ring region to define a body. The top surface defines an outer radius and is equipped with a combustion bowl recessed in the top surface and concentric therein to define an inner radius. The outer radius and the inner radius define a low geometric squish ratio. The combustion bowl has a deep piston center depth and a relatively high re-entrant angle at a periphery of the combustion bowl radius.

Abstract: An improved ignition-combustion system for internal combustion engines with preferably a 2-valve engine 17/18 with dual-ignition 14a,14b with squish-flow channels 12a, 12b, and cylindrical high energy density pencil coils with open ends including biasing magnets 42a to 42d, the spark being 300 to 450 ma peak secondary current Is, and the primary current being 20 to 25 amps Ip of 60 to 100 turns Np, or bifiler turns of 120 to 200 turns of wire, with turns ratio Ns/Np of 50 to 70, and coil switches being 600 volt IGBTs; and power convertor with energy storage capacitor storing many times the coil energy of 80 mJ to 160 mJ, of 20 to 60) volts power supply, the engine operating with a single ignition firing of 80 to 16 mJ, except when it is cold started or requires multi-firing for better performance, such as under lean burn or high EGR operation.

Abstract: An improved internal combustion engine is provided with at least one channel or groove on its compression face. The at least one channel or groove can be open and of uniform width. The channel or groove can direct flow of an air-fuel mixture to increase combustion efficiency.

Abstract: The invention relates to a direct-injection internal combustion engine that is operated in a first operating range associated with the low part load, with largely homogeneous combustion of the mixture and subsequent injection. Said internal combustion engine is operated in a second operating range associated with the middle part load, with low-temperature combustion of the mixture. In this way, minimum nitrogen oxide and soot emissions and a high degree of efficiency can be achieved both in the lower part load region and up to the full load region.

Abstract: A structure of a chamber in a combustion engine includes a ring-groove portion formed on the piston, a squish-area making portion formed on a top surface of the piston for a squish-area, an outer edge portion formed around the top surface excepting the squish-area making portion, and a land portion formed around a side surface between the ring-groove portion and the top surface. The land portion includes, a squish-land portion formed between the ring-groove portion and the squish-area making portion, an outer-edge-land portion formed between the ring-groove portion and said outer edge portion, the outer-land portion being smaller than the squish-land portion in height.

Abstract: This invention relates to a combustion chamber structure for a spark-ignition engine, which comprises a combustion chamber defined between a bottom surface of a cylinder head and a top surface of a piston in such a manner that the bottom surface of the cylinder head serves as a ceiling wall thereof, and a spark plug having a sparking end protruding from the ceiling wall into the combustion chamber. In this combustion chamber structure, when the piston is at a top dead center, a principal space of the combustion chamber is comprised of a first combustion space around the sparking end of the spark plug and a second combustion space around a circumference of a cylinder bore. Further, the first combustion space and the second combustion space are communicated with each other through a small interspace zone where an interspace between the ceiling wall and the top surface of the piston is narrowed. The combustion chamber structure makes it possible to increase compression ratio in a practically effective manner.

Abstract: A geometry for an IC combustion chamber is disclosed that increases the air-fuel mixing efficiency within the chamber. The piston head includes a squish surface portion for generating a squish jet, and a bowl portion that cooperatively with the cylinder head defines a combustion volume. A horizontal channel extends between the squish surface portion and the bowl portion, and is adapted to provide a high-momentum jet into the bowl portion. A transverse channel may also be provided that directs the squish flow toward the horizontal channel, thereby generating a toroidal vortex therein. A premix fuel injector may inject fuel near the upstream end of the horizontal channel. A converging nozzle portion near the distal end of the horizontal channel may increase the flow speed into the bowl portion. A chamber fuel injector is disposed near the downstream end of the horizontal channel.

Abstract: A direct injection spark ignition engine comprises a cylinder, a piston, a fuel injector arranged at one side of a center axis of the cylinder for directly injecting fuel into the combustion chamber, and a smoothly continuous lowered recess formed on a top surface of the piston surface. The recess has a first cross section along a first plane including the cylinder center axis and a nozzle end of the injector. The first and second lower contours are smoothly connected with each other through a lowest point of the first cross section. The first lower contour is located at the one side of the cylinder center axis. The second lower contour is at the other side. The first contour has a larger radius than a radius of the second contour. Accordingly, the fuel spray having greater movement energy may impinge the recess at a regulated impinging angle.

Abstract: A squish surface having the shape of a plane surface orthogonal to the axis of a piston is formed on the intake side of the piston top surface. A squish area is formed between the squish surface and a plane surface-shaped squish surface on the cylinder head side, and at the same time, a squish guide surface is formed in the piston top surface so as to be continuously ridged from the squish surface toward the vicinity of a spark plug.

Abstract: An internal combustion engine that includes a cylinder block formed with a cylinder bore, a cylinder head operatively connected to the cylinder block; a piston slidably disposed in the cylinder bore to define a combustion chamber; an engine front side squish area and a rear side squish area where the engine front and rear side squish areas include narrow gaps formed between a cylinder head and the piston is disclosed. The engine front side squish area and the engine rear side squish area generate a squish flow in the combustion chamber in response to the piston moving within the cylinder bore. Engine front and rear side igniter plugs are also provided that each include a pair of electrodes placed adjacent the respective engine front and rear side squish areas so that squish flow may pass through an igniter gap defined between the pairs of electrodes of the front and rear side igniter plugs.

Abstract: There is provided a combustion chamber structure in an internal combustion engine in which, at a peripheral portion of a combustion chamber, a gap between a cylinder head lower face and a piston upper face is small in intake-to-intake and exhaust-to-exhaust zones and gradually increases toward an intake-to-exhaust zone. According to such design, the mixture in the peripheral portion of the combustion chamber can smoothly flow from the intake-to-intake and exhaust-to-exhaust zones to the intake-to-exhaust zone along the peripheral face of the cylinder. The flow of air-fuel mixture from the intake-to-intake zone collides at the center of the intake-to-exhaust zone with the flow of mixture from the exhaust-to-exhaust zone, and the combined flow goes over a conical tapered portion in the upper face of the piston and vigorously enters a central recessed portion thereof. Therefore, it is possible to satisfactorily mix an air-fuel mixture with a simplified configuration.

Abstract: There are provided on an upper surface of a piston 13 which confronts to a combustion chamber two first squish areas A1 each containing a flat surface 13a extending along an outer circumferential portion the piston 13 in an arc-like fashion and two second squish areas A2 formed between valve recesses 13d, 13e of respective pairs of inlet and exhaust valves 19, 21 and each containing a protruding portion which protrudes upwardly.

Abstract: An internal combustion aircraft engine comprising a cylinder head having a cylindrical head bore formed therein, a piston, and spark plugs, the cylinder head bore and piston designed to reduce engine knock. The cylinder head is fixedly attached to a top end of a cylinder barrel formed with cylindrical walls, the cylinder head bore and the cylindrical walls defining a cylinder. The cylinder head bore has formed therein an outwardly protruding cavity with respect to the top end of the cylinder barrel. The piston has a piston crown, and the piston contained within the cylinder, the piston crown, the cylinder walls, and the cylinder head bore define a combustion chamber. The piston crown has a concavity formed therein, and the piston is constructed and arranged to reciprocate within the cylinder. The concavity of the piston crown and the cavity cooperate at a top dead center position of the piston to form a swirl chamber.

Abstract: Process which, by spray-controlled, directly injected combustion with the aid of step-by-step technical development of the whole of the combustion system, achieves an intensified mixing process during injection and after-burning, which speeds up soot oxidation during various stages so effectively that the engine can be run with sufficiently high EGR content for desired NOx and soot content down to ultra-low emissions, at the same time as parameters which control the efficiency are decoupled from measures for desired emission level, thereby enabling optimum efficiency to be attained for the process.

Abstract: There are provided on an upper surface of a piston 13 which confronts to a combustion chamber two first squish areas A1 each containing a flat surface 13a extending along an outer circumferential portion the piston 13 in an arc-like fashion and two second squish areas A2 formed between valve recesses 13d, 13e of respective pairs of inlet and exhaust valves 19, 21 and each containing a protruding portion which protrudes upwardly.

Abstract: A cylinder head and a four-stroke and two-valve spark-ignition internal combustion engine spark-ignition internal combustion engine are provided which allows for enhancing the output and the rotational speed of the engine by increasing the flame propagation rate of the burning air-fuel mixture. As the piston 4 moves up toward the top dead center, the air-fuel mixture within the squish area 14 is inducted along the squish guide groove 15 toward the ignition electrode 7a of the ignition plug 7 and is then ignited by the ignition electrode 7a when the piston 4 approaches the top dead center. When the mixture is ignited by the ignition electrode 7a, there is a flow of the air-fuel mixture around the ignition electrode 7a (the ignition plug aperture 12) inducted by the squish guide groove 15 so as to move toward the center of the combustion chamber, so that the flame propagation rate within the combustion chamber may be enhanced as the ignition is effected on such moving air-fuel mixture.

Abstract: A combustion chamber for a swirl flow two valve spark ignition direct injection engine includes a cylinder with a closed end having a wedge shaped combustion chamber recess. A fuel injector extends through the closed end near a shallow side of the wedge recess. A spark plug extends through the closed end at a deeper part of the wedge recess opposite from the injector. A single pair of laterally spaced intake and exhaust valves control intake and exhaust ports opening into the wedge recess. A piston in the cylinder has an outer diameter and includes a head end having a raised pedestal with a shallow upwardly angled face ending at a raised ridge and enclosing a shallow bowl in the head end. The bowl is generally oval with a major dimension generally aligned with a cylinder centerline through the valves.

Abstract: A direct fuel injection internal combustion engine configured to reduce engine knock during high speed operation of the engine is provided. The engine comprises a cylinder head including a lower surface portion closing an upper end of a cylinder to define a combustion chamber between a piston upper surface and the cylinder head lower surface portion. The lower surface portion has therein an upwardly extending recess. The recess has a lower end which is complementary with the piston surface and an upper end. The lower end of said recess has an area in a plane perpendicular to a longitudinal axis of the cylinder and that area comprises a range from more than 20% to about 65% of the cross-sectional area of the cylinder.

Abstract: The present invention provides a fuel injector mounted on a side of a combustion chamber and delivers an ovalized fuel spray toward an oblong piston bowl of the chamber. The ovality of the spray is selected in relation to the oblong piston bowl and the motion of the combustion chamber air charge during the piston compression stroke to maintain the fuel charge within the piston bowl volume (including the space above the bowl) during compression and combustion of the fuel charge in the chamber. The shape of the oval spray may be adjusted as desired. In a specific embodiment, the ovality of the fuel spray indicated by the ratio of the major dimension to the minor dimension is in the range of about 2/1 to 4/1 for delivery into an oblong piston bowl with an ovality of about 1.2/1 to 1.5/1.

Abstract: An internal combustion aircraft engine comprising a cylinder head having a cylindrical head bore formed therein, a piston, and spark plugs, the cylinder head bore and piston designed to reduce engine knock. The cylinder head is fixedly attached to a top end of a cylinder barrel formed with cylindrical walls, the cylinder head bore and the cylindrical walls defining a cylinder. The cylinder head bore has formed therein an outwardly protruding cavity with respect to the top end of the cylinder barrel. The piston has a piston crown, and the piston contained within the cylinder, the piston crown, the cylinder walls, and the cylinder head bore define a combustion chamber. The piston crown has a concavity formed therein, and the piston is constructed and arranged to reciprocate within the cylinder. The concavity of the piston crown and the cavity cooperate at a top dead center position of the piston to form a swirl chamber.

Abstract: A direct fuel injection internal combustion engine configured to reduce engine knock during high speed operation of the engine is provided. The engine comprises a cylinder head including a lower surface portion closing an upper end of a cylinder to define a combustion chamber between a piston upper surface and the cylinder head lower surface portion. The lower surface portion has therein an upwardly extending recess. The recess has a lower end which is complementary with the piston surface and an upper end. The lower end of said recess has an area in a plane perpendicular to a longitudinal axis of the cylinder and that area comprises a range from more than 20% to about 65% of the cross-sectional area of the cylinder.

Abstract: An engine combustion chamber includes a cylinder head, a cylinder wall and a piston. The piston has a bowl volume formed therein. A fuel injector is disposed adjacent one edge of the bowl and an ignition source is within a predetermined distance of another, substantially opposite, edge of the bowl. The bowl has a transporting surface which directs a fuel-air charge from the bowl volume toward the ignition source. The piston, bowl and cylinder head cooperate through a plurality of design features to provide an efficient combustion chamber.

Abstract: A direct fuel injection internal combustion engine configured to reduce engine knock during high speed operation of the engine is provided. The engine comprises a cylinder head including a lower surface portion closing an upper end of a cylinder to define a combustion chamber between a piston upper surface and the cylinder head lower surface portion. The lower surface portion has therein an upwardly extending recess. The recess has a lower end which is complementary with the piston surface and an upper end. The lower end of said recess has an area in a plane perpendicular to a longitudinal axis of the cylinder and that area comprises a range from more than 20% to about 65% of the cross-sectional area of the cylinder.

Abstract: A combustion chamber in a reciprocating-piston internal combustion engine having at least one inlet duct and at least one outlet duct is formed by a cylinder head and piston each having respective annular squish surfaces for acceleration of fresh gases. A mixture guide element having a recess in its top adjoins the piston crown and the inlet duct to the cylinder is arranged to cause fresh gases to flow with a circulatory movement into the combustion chamber. The configuration increases power output while reducing pollution emissions.

Abstract: A method of controlling fuel injection flow in a cylinder of an internal combustion engine. A piston head of the engine is provided with a combined flow redirector and holding bowl recess extending into a top side of the piston head. A fuel injection port is provided in the cylinder in a bottom portion of a combustion chamber of the cylinder located above the top side of the piston head when the piston is at a bottom dead center position. Fuel is injected from the injection port into the recess. The step of injecting comprises injecting the fuel at a first velocity when the engine is operating at a first speed, and injecting the fuel at a second faster velocity when the engine is operating at a second faster speed.

Abstract: An improved ignition-combustion system for internal combustion engines comprising a compact combustion chamber zone (4) in the engine cylinder head (6) mainly under the exhaust valve (8) and with large air-squish zones (124a, 124b) formed at the edge of the combustion zone which produce colliding squish flows (2, 2a, 3a, 3b) with high turbulence (3c) at the center of the combustion zone, with one or two spark plugs (12a/118, 12b/18a) located at the edge of the combustion zone within the high squish zones, resulting in a combined ignition and combustion system of colliding-flow-coupled-spark discharge (CFCSD), with the ignition employing high energy flow-resistant ignition sparks which move under the influence of the squish flow towards the central turbulence region as the piston nears engine top center, to produce rapid and complete burning of lean and high EGR mixtures for best engine efficiency and lowest emissions.

Abstract: A combustion chamber design layout of grooves or channels or passages formed in the squish band to further enhance turbulence in the charge prior to ignition as compared to existing designs with squish bands or hemispherical layouts in I.C. Engines. These grooves or channels or passages after ignition direct the flame front to cause multipoint ignition during the combustion cycle resulting in the following distinct advantages over existing designs in practice. First, quicker and complete clean burn combustion; second, lower operating temperatures due to the higher flame velocities; third, enhanced torque and power through the entire range resulting in better fuel economy with lower Emissions; and fourth, smoother engine operation through the entire range enhancing engine life.

Abstract: In an internal combustion engine a spark plug is disposed at a nearly central position of a combustion chamber formed between the underside of a cylinder head and a crown of a piston. Intake valves are disposed on one side of the cylinder head, while exhaust valves are disposed on the other side of the cylinder head. A recess having a generally rectangular bottom is formed in the piston crown and extends in a slap direction connecting the intake and exhaust valves. The recess has vertical wall portions for the formation of squish flows at both ends thereof in the slap direction. The vertical wall portions are contiguous to the piston crown and connect both ends of the recess smoothly with the piston crown. Thus, the piston realizes a stratified charge without obstructing reverse tumbling flows. The symmetric shape of the piston in a slap direction maintains the piston in good weight balance, and thereby eliminates mechanical loss, such as oscillation.

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.