Abstract: An engine system includes an engine, a main combustion chamber formed by a cylinder head and a piston, an auxiliary chamber formed with a communicating hole communicating with the main combustion chamber, an injector configured to inject fuel into the main combustion chamber, an ignition plug provided to the auxiliary chamber and configured to ignite a mixture gas inside the auxiliary chamber, an accelerator opening sensor, and a control device. The control device controls the injector so that an air-fuel ratio of the mixture gas inside the auxiliary chamber becomes a first air-fuel ratio when an engine load range is a first range, and the air-fuel ratio of the mixture gas inside the auxiliary chamber becomes a second air-fuel ratio leaner than the first air-fuel ratio when the engine load range is a second range where the engine load is higher than in the first range.

Abstract: A fuel injection control causes a fuel injection valve to execute at least: a main injection to inject fuel at timing when a piston is positioned near a compression top dead center; a pilot injection to inject the fuel at timing earlier than the main injection; and a low penetration injection to inject the fuel at timing earlier than the pilot injection or timing later than the main injection. The fuel injection control device includes: a first injection control module that executes at least one of the main injection or the pilot injection at timing to inject the fuel toward a joint portion of a cavity; and a second injection control module that executes the low penetration injection to inject the fuel only into a radial central region of a combustion chamber.

Abstract: The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder, a cylinder head carrying fuel injection, a piston sliding in the cylinder, a combustion chamber limited on one side by upper face of the piston comprising a projection extending in the direction of the cylinder head and in the center of a concave bowl (46) with at least two mixing zones. The fuel injection projects fuel in at least two fuel jet sheets with different sheet angles, with a lower sheet having a jet axis C1 for one zone and an upper sheet having a jet axis for the other zone. The injection feeds fuel into the combustion chamber with a different flow rate for each sheet for dedicated targeting in the mixing zones of the combustion chamber.

Abstract: The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12) carrying fuel injection means (14), a piston (16) sliding in the cylinder, a combustion chamber (34) limited on one side by an upper face (44) of the piston comprising a projection (48) extending in the direction of the cylinder head and located in a center of a concave bowl (46). The engine comprises injection projecting fuel in at least two fuel jet sheets. One of the zones comprises a toroidal volume (64) having center B with a flat bottom (56) into which fuel jets (40) of the lower sheet are injected so that an axis C1 of the lower sheet jets is contained between center B and projection (48).

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 arcuate indent is formed in the top surface in aligned fashion with the fuel jet and including an entry surface, a recirculation surface and a wall.

Abstract: The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12) carrying fuel injection means (14), a piston (16) sliding in this cylinder, a combustion chamber (34) having on one side an upper face (44) of the piston comprising a projection (48) extending in the direction of the cylinder head and located at the center of a concave bowl (46). The engine comprises an injector projecting fuel in at least two fuel jet sheets with sheet injection angles (A1, A2), a lower sheet (36) of jet axis C1 and an upper sheet (38) of jet axis C2, at least two mixing zones (Z1, Z2) of the combustion chamber. According to the invention, one of the zones comprises a toroidal volume (64) of center B into which fuel jets (40) of the lower jet are injected in such a way that axis C1 of the lower jet is contained between center B and projection (48).

Abstract: The present disclosure relates to a combustion chamber of a diesel engine, which has a recessed combustion bowl to mix fuel injected from an injector with air, the combustion chamber including: a cylinder head which has the injector mounted thereto and is positioned at an upper side of the combustion bowl; a cylinder block which is positioned at a lower side of the cylinder head; and a piston which moves upward and downward in the cylinder block and faces the cylinder head, in which a plurality of radial inducers is provided on a bottom surface of the cylinder head around the injector.

Abstract: The present invention generally relates to a recess in the top of a piston. More particularly, the present invention relates to a crescent-shaped recess in the top of an expansion piston of a split-cycle engine.

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: Disclosed is a diesel engine comprising a cylinder head; a combustion chamber within the cylinder head, the combustion chamber being in the shape of a bowl; and a piston having a piston crown, the piston crown having a dome-shape for protruding within the cylinder head during a combustion operation near or at top dead center. The engine is preferably a two stroke crankcase compression engine. Use of a combustion chamber in the shape of a shallow bowl along with other parameter selection decreases the rates of combustion pressure rise while providing reasonable power output.

Abstract: Cool combustion refers to combusting fuel in a region of equivalence ratios and temperatures between a soot production region and a NOx production region. Cool combustion is achieved by compressing air in a variable volume of an internal combustion engine beyond an auto-ignition point of a fuel. The compressed air is made to flow in an airflow passage by movement of a piston in the vicinity of top dead center. Fuel is injected into the compressed air stream, auto-ignites and burns in the low emissions region between NOx and soot formation regimes.

Abstract: A piston for an internal combustion engine is disclosed. The piston has a piston crown with a face having an interior annular edge. The piston also has first piston bowl recessed within the face of the piston crown. The first piston bowl has a bottom surface and an outer wall. A line extending from the interior annular edge of the face and tangent with the outer wall forms an interior angle greater than 90 degrees with the face of the piston. The piston also has a second piston bowl that is centrally located and has an upper edge located below a face of the piston crown.

Abstract: An engine has a plurality of combustion chambers, each of which is divided into an ignition chamber and a first combustion chamber. The chambers are linked by a transfer tube defining a passageway facilitating communication between the ignition chamber and the first chamber. A valve is provided for selectively opening and closing the passage. A tube is provided with an opening intermediate of its length allowing fuel to be injected via a fuel injector into the passage.

Abstract: An internal combustion engine 10 includes a first combustion chamber (20) in each of its cylinders (12). First fuel injector (24) injects a first volume of fuel into the chamber (20). A housing (28) defining an auxiliary combustion chamber (30) is coupled to the engine (10). The housing (28) includes a passage (32) that extends from the auxiliary combustion chamber (30) to the first combustion chamber (20). Fluid communication through the passage (32) is controlled by a valve (34). When the valve (34) is in an extended position it provides a high impedance to the flow of fluid between the auxiliary combustion chamber (30) and the first combustion chamber (20). However when in a retracted position, the valve (34) allows unimpeded fluid flow between the two chambers. An auxiliary air and fuel injector (38) to inject a fuel/air mixture into the auxiliary combustion chamber (34). Air for the auxiliary injector (38) is sourced from outside of the first combustion chamber (20), i.e.

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: An injection device for an internal combustion engine, especially a diesel engine, with a combustion chamber (16) for each defined by piston (2), cylinder and cylinder head (1), a multi-hole injection nozzle (5) and a shroud (3) projecting from the cylinder head (1) into the combustion chamber (16) and surrounding the nozzle (5) in such a way that a precombustion chamber is formed between shroud (3) and piston (2) at TDC, and a combustion process for an internal combustion engine, especially for a diesel engine, with an injection device as described hereinabove, wherein combined direct and swirl-chamber injection takes place in the vicinity of TDC.

Abstract: A combustion system for a divided chamber engine that incorporates a pre-combustion chamber disposed to one side of the cylinder and that communicates with the main combustion chamber through two diverging transfer passages the open ends of which are aimed to direct the discharge from the pre-combustion chamber towards the sides of the combustion chamber and not at the center of the piston or the exhaust valve wherein the localized temperature at the piston's center is reduced and the exhaust valve temperature is not elevated.

Abstract: An internal combustion engine comprises one or more pairs of first and second cylinders, the first cylinder having a larger swept volume than the second cylinder and respective first and second pistons reciprocable in the cylinders. The second piston has a drive stem and divides the second cylinder into a first volume containing the drive stem of the second piston and a second volume between the two pistons. An air inlet and an exhaust outlet are provided for the first cylinder. A common combustion space is formed between the pistons when the pistons are substantially at their inner dead center positions, the combustion space comprising the second volume. A transfer means enables gas flow between the first volume and the combustion space whilst an inhibiting means inhibits the movement of a substantial amount of fuel/air mixture from the first volume into the second volume until toward the end of the compression stroke of the second piston.

Abstract: An internal combustion engine of the valve-in-head type having a low profile cylinder head which requires minimal head-room in the engine compartment of an automotive vehicle. The cylinder head has a rectilinear configuration with the valve trains disposed on horizontal axes extending transversely of the cylinder head. Each valve train in the cylinder head is provided with precise axial support at both ends of the train. The engine has a relatively thin upstanding combustion chamber over each cylinder and one or more pairs of poppet valves per cylinder each having a sealing surface adjacent its outer edge for engagement with respective seats defined by axially aligned header tubes. Each valve has a relatively short neck extending through the combustion chamber during the intake and compression strokes and when the fuel-air mixture is fired.

Abstract: The present invention integrates the combustors and the air intake/exhaust passages in a thermally insulating engine into an assembly to simplify the structure and to space the parts thereof. The space between the subcombustion chamber and the main combustion chamber is reduced by the base installed above the piston head. In addition, a plurality of connection holes are arranged in an oblique radial pattern drilled in the piston head projection creating a vortex within the subcombustion chamber. In the combustion process, the flame expands within the main combustion chamber and mixes with air for combustion. The subcombustion chamber is installed in the center of the cylinder and surrounded by the air intake passage and the exhaust passage. The single-unit structure is made by using a ceramic material for an outer peripheral wall. Additionally, a plurality of the air intakes and exhaust outlets are provided on the piston projection so that respective channels have a wide opening.

Abstract: A diesel engine (10) has a pre-combustion chamber (30) with an angled and tapered transfer passage (60) leading to the main combustion chamber (44). The transfer passage (60) is tapered to provide a larger lower end (62) facing the main chamber (44) and smaller upper end (64) facing the pre-combustion chamber (30). Air passing through the passage (60) during the compression stroke undergoes heating and swirling within the pre-combustion chamber. The piston has an upper surface (46) with recessed lobes (20) and (22) and recessed passage area (28). Each recessed lobe functions as a valve pocket for the respective intake valve (32) and exhaust valve (42). The valve pockets are deep enough to provide sufficient valve lifts to allow valve overlap periods comparable with spark ignition gasoline engines without interfering with the piston upper surface (46).

Abstract: A diesel engine (10) has a precombustion chamber (30) with four circumferentially spaced and angled transfer passages (60, 61) leading to the main combustion chamber (44). Each transfer passage (60, 61) is tapered to provide a larger lower end (62) facing the main chamber (44) and smaller upper end (64) facing the precombustion chamber (30). Air passing through the passages during the compression stroke undergoes heating and swirling within the precombustion chamber. The flame front passing from the precombustion chamber to the main combustion chamber are aimed toward the centers (68 and 69) of respective recessed lobes (20 and 22) within piston (18).

Abstract: A piston and cylinder arrangment for an internal combustion engine designed to run on diesel and similar fuels, comprises a cylinder defining a main combustion chamber, a piston reciprocatable within said cylinder and having a thermally insulating plate on its upper surface, a cylinder head including a precombustion chamber, a fuel injector for injecting fuel into said precombustion chamber, and a thermally insulated block of material with high heat retention ability surrounding the precombustion chamber to maintain a high temperature a high temperature of at least about 500.degree. C. in the precombustion chamber and thereby facilitate fuel ignition at moderate compression ratios. A mass of material with high heat retention ability is mounted on the insulated surface of the piston so as to remain at a high temperature during running of the engine and facilitate the combustion process during the downward stroke of the piston.

Abstract: The "Isolated Combustion and Dilution Expansion (ICADE) Engine", is a piston/cylinder arrangement used primarily for the compression of air and the expansion of diluted hot combustion products. Fuel injection and rapid combustion take place inside a separate combustion chamber, using a near stoichiometric mixture. The combustion pressurization provides the pressure needed to accelerate the combustion products tangentially into the donut shaped cavity formed by the piston/cylinder clearance. There they establish a vortex which enhances rapid mixing, rapid cooling to quench NO.sub.x forming reactions and to temporarily store the kinetic energy of the combustion products to limit the combustion pressure peak acting on the piston surface. The tangential entry also permits detonation combustion without normal shock reflections on the piston surface, thus preventing "knock".

Abstract: A piston crown is formed with a cavity including a first flame deflecting member which is located amid three flame dispersion zones and which splits burning gases ejected from a transfer port into a first dispersion zone, while the piston is proximate its TDC position, into two flows. The arrangement additionally induces the two flows to assume two essentially symmetrical swirling patterns in second and third dispersion zones. After the piston has descended by a predetermined amount, the burning gases are supplied directly into the second and third zones.

Abstract: An internal combustion engine has first and second cylinders (12, 14), the first cylinder (12) having a larger swept volume than the second cylinder (14) and the second cylinder being formed in the crown of the first cylinder. First and second pistons (16, 18) are reciprocable respectively in the first and second cylinders (12, 14), the second piston (18) being formed as a protrusion on the crown of the first piston (16). A combustion chamber (20) is formed in the second piston (18) with an air port (44) opening into the first cylinder (12) and a second port (40) opening into the second cylinder (14). A first inlet is provided (25) for supplying air or the like into the first cylinder (12) during an induction stroke of the first piston (16) together with a fuel inlet (36) for supplying fuel to said second cylinder (14).

Abstract: Wall surfaces which define essentially circular recesses are constructed to deflect the flow of burning gases from a swirl chamber in a manner to either tighten the swirl formed therein or to improve the initial splitting of the frame in a manner which increases the amount of gases which are induced to undergo swirling in the recesses.

Abstract: A combustion chamber formed in the crown of a piston for an indirect injection diessel engine is described the combustion chamber having an elongate entry channel adjacent the gas efflux of a precombustion chamber, the channel leading into four branches which generate vortices in the burning charge and which vortices are coherent and mutually self-reinforcing.

Abstract: A combustion chamber and method of operating a diesel engine to insure maximum air utilization. The engine has a main chamber and a subchamber that communicates with the main chamber through a communication passageway. Fuel injection into the subchamber is begun at a time when the throat area of the engine by which the main chamber communicates with the communication passageway is equivalent to approximately the effective flow area of the communication passageway so as to insure maximum air utilization.

Abstract: The subject of the invention is a mixture-compressing spark-ignition internal-combustion engine with a main combustion chamber and an auxiliary combustion chamber in the cylinder head. The auxiliary combustion chamber has a spark plug and is connected to the main combustion chamber by an overflow bore. The overflow bore is aligned with the piston crown in such a way that an emerging ignition jet aims at a surface region of the piston crown. According to the invention, the overflow bore is arranged concentrically with respect to the longitudinal center axis of the cylinder and the surface region of the piston crown is designed as an impact area lying opposite the bore and running orthogonally with respect to the jet direction.

Abstract: A piston crown is formed with cavity a which includes a first flame deflecting member which divides the flame ejected from a transfer port interconnecting a swirl chamber with a main combustion chamber while the piston is relatively close to its TDC position and a second flame deflecting arrangement which divides the flame flow after the piston has descended by a given amount. The stage deflections of the flame promotes extensive dispersion thereof and the formation of a flame plume which engulfs a relatively large amount of the air in the combustion chamber and improves mixing of the burning gases and unburnt fuel with the air in the combustion chamber.

Abstract: The present invention relates the technology to enhance the mixing performance of air-fuel mixture in a combustion chamber with a domed precombustion chamber for a spark-ignition engine, and aims to attain the enhanced mixing performance owing to the forcible generation of a multiplicity of small swirls by forcing the air-fuel mixture to flow into the main combustion chamber centripetally from the inside of the cylinder and then to turns three times in a step-like state with being accelerated on the way into the precombustion chamber through the connecting channel at the compression stroke. The main combustion chamber is formed by hollowing the center side portion of the piston head. The piston head is further provided with the connecting channel formed on the annular bank around the main combustion chamber so as to be faced onto by the domed precombustion chamber in the cylinder head and to be stepped up higher than the bottom of the main combustion chamber.

Abstract: An internal combustion engine having a main combustion chamber in a top portion of a piston, and an ignition chamber which is provided with a fuel injection valve and an ignition plug, in a cylinder head, the direction in which fuel is ejected from the fuel injection valve being set in accordance with the forward direction of a swirl, the axis of the ejected fuel being spaced from a central portion of the main combustion chamber by a distance of not more than 1/2 of the radius thereof, a recess in communication with the main combustion chamber being provided in the section of the top portion of the piston which is on an extension of the ignition chamber.

Abstract: In order to avoid the formation of smoke and HC when the compression ratio of a swirl chamber type Diesel engine is lowered either by design or by operation in rarified atmospheres, the fuel injector is located on one side of the center axis of the swirl chamber so as to maximize the distance for which the injected fuel can travel before contacting a wall of the chamber and the auxiliary transfer port through which a fraction of the injected fuel is fed to the main combution chamber is arranged so that the axis thereof intersects the axis of the fuel injector and therefore the trajectory along which fuel is injected, at a point defined within the swirl chamber per se and on the opposite side of the center axis with respect to the fuel injector.

Abstract: In order to promote a good flame dispersion within the combustion chamber of a swirl chamber type Diesel engine, a shaped recess formed in the piston crown is arranged to have a trench portion into which the flame from the swirl chamber is injected and mirror image flame dispersion portions on either side of the trench which terminates at the periphery of the piston crown. This arrangement inhibits the formation of secondary flame flows which tend impede desirable patterns within the flame disportion portions and simultaneously enlarges the dispersion area. In addition, careful selection of the dimensions of the transfer port which interconnects the swirl chamber and the main combustion chamber, and the various sections of the shaped recess, promotes further reductions in HC and smoke emissions.

Abstract: An auxiliary chamber injection port providing communication between a main combustion chamber and an auxiliary combustion chamber has its axis composed of a combination of a straight line and an arc in a manner to satisfy the following relationships: .theta..sub.1 <.theta..sub.2 ; 20.degree..ltoreq..theta..sub.1 .ltoreq.45.degree.; and 35.degree..ltoreq..theta..sub.2 .ltoreq.67.5.degree., if the outflow angle of the axis of said auxiliary chamber injection port at the open end at the side of said auxiliary combustion chamber is designated at .theta..sub.2 with respect to a plane normal to the center line of said auxiliary combustion chamber and if the outflow angle of the axis of said auxiliary chamber injection port at the open end at the side of said main combustion chamber with respect to a plane normal to the center line of said auxiliary combustion chamber is designated at .theta..sub.1.

Abstract: Heat plugs made of durable, heat resistant material are useful for protecting aluminum pistons from the jet flame of burning fuel emitted from the precombustion chamber of some compression ignition engines. However, when slower burning fuel such as vegetable oil is burned, unburned fuel is sometimes deflected by the heat plug against the adjacent cylinder bore where it dilutes the lubricating oil and causes high wear to that portion of the bore and to the piston rings. The subject heat plug (26) is provided with a barrier (37) which prevents unburned fuel from being deflected against a portion of the cylinder bore (12) nearest the heat plug. Thus, that unburned fuel remains in the burning gaseous mixture in the combustion chamber and is burned during the combustion process within the combustion chamber.

Abstract: The combustion structure of an internal combustion engine comprises a cavity formed in the end wall of the piston and a projection on said piston adjacent its cavity to that the projection in the injection, ignition and combustion phase of the cycle only constricts communication between the two cavities and defines with the cavity in the wall a combustion chamber in which at least three distinct swirls of fluid are induced by the shape of the projection and a resultant three-dimensional circulation sweeps throughout this chamber. The fuel is injected into the circulation in this chamber and ignition takes place therein as well.

Abstract: In a turbulence chamber diesel engine, fuel consumption, smoke and noise are reduced by a transfer port arrangement having a plano-convex lens-like cross section with rounded off edges in which a convex side is disposed inwardly toward the cylinder axis and a flat side is disposed outwardly toward the cylinder periphery, the port cross-sectional area equals about 1% to 0.7% of that of the cylinder and the port angle of entry with the cylinder closed end is about 37.degree. to 44.degree..

Abstract: An internal combustion engine according to the present invention includes a piston reciprocally movable within a cylinder for affording rotational motions to a crankshaft, a combustion chamber formed among the piston, the cylinder and a cylinder head, an intake valve mechanism for opening and closing an intake passage to be communicated with the combustion chamber, igniting means having its igniting portion facing the combustion chamber, fuel supply means for supplying a predetermined quantity of fuel toward a predetermined wall of the combustion chamber, which is heated to a predetermined high temperature by the combustion in the combustion chamber, and an exhaust valve mechanism for opening and closing an exhaust passage to be communicated with the combustion chamber.

Abstract: Disclosed is a two-cycle, internal combustion engine including an engine block, and a cylinder in the engine block having a head and generally opposed inlet and outlet walls respectively including at least one intake port through which a fresh charge is admitted into the cylinder and at least one outlet port through which exhaust gases are exhausted from the cylinder. A piston is mounted for reciprocative movement inside the cylinder between a first position spaced from the cylinder head wherein the intake port is uncovered, a top dead center position, and a third position wherein the piston approaches the top dead center position. The piston has a top, an inlet face portion which periodically covers and uncovers the intake port and an outlet face portion which periodically covers and uncovers the outlet port. The piston and cylinder have a configuration causing increased swirling of the fresh charge in the cylinder as the piston moves from the third position to the top dead center position.

Abstract: An air-compressing internal combustion engine which includes a cylinder block, a plurality of cylinders in the cylinder block, a piston reciprocably mounted in the respective cylinders, and a cylinder head disposed on the cylinder block. A precombustion chamber is arranged in the cylinder head and associated with the respective cylinders and a number of approximately radially extending burner holes are provided around a periphery of an end of the precombustion chamber. A depression is arranged in the head of each of the pistons and stellate depressions emanate from the depression in the cylinder head. Each of the stellate depressions ascend continuously in a radially outward direction and a further substantially axially extending burner hole is provided at the end of the precombustion chamber.

Abstract: A system for converting a spark ignition Otto cycle engine into a compression ignition or Diesel cycle engine comprises:(a) compression means connected to the engine piston end portion closest the combustion zone to effect an increase in heating and pressurization of intake air in that zone,(b) pre-combination chamber means independent of, and attached to, the engine head to communicate with said zone via the spark plug opening in the head, said chamber means having an inlet to pass pressurized fuel into the interior of said chamber means, for mixing with air from said combustion zone to pre-combust and flow to the combustion zone wherein combustion is completed, and(c) cooling means including a coolant passage adjacent said pre-combustion chamber to circulate fluid coolant in heat receiving relation with said chamber.

Abstract: An internal combustion engine operating with self-ignition which is equipped with a main combustion space including a piston recess and with an auxiliary chamber arranged in the cylinder head an injection nozzle is coordinated to the auxiliary chamber while the chamber includes an insert forming an overflow channel provided with several discharge holes terminating in the main combustion space. The discharge holes are matched as regards their direction and cross section to the main combustion space-air volume component to be seized or impinged upon by the respective jet passing through the corresponding discharge hole. The discharge holes are thereby proportional in cross section to the main combustion space-air volume component located in front thereof when the piston is in a position corresponding to the center point of the full-load heat-release curve and are directed toward the center of gravity of the respective main combustion space-air volume component.

Abstract: A piston for internal combustion engines, especially for motors of the Diesel type. On purpose to reduce the heat diffusion from the piston crown to the piston portion where are fitted the sealing piston rings, provision is made of an internal circular groove intended to reduce the thickness of the connection portion between the piston crown and the side portion where are fitted the sealing rings, an external cut tangentially formed in the piston side portion substantially at the connection thereof with the piston crown, i.e. above the grooves of the piston rings, being substituted for the circular groove which is interrupted below the regions of the piston crown provided with any recess which would cause the thickness of the connection portion to be too slight.

Abstract: Disclosed is an internal combustion engine comprising a main combustion chamber and an auxiliary combustion chamber interconnected by two connecting passages with each other. A raised portion having a flat lower end face is formed on the inner wall of the cylinder head. A squish area is formed between the flat lower end face of the raised portion and the flat top surface of the piston when the piston reaches the top dead center. The spark gap of the spark plug is located in a first one of the connecting passages or in the auxiliary combustion chamber at a position near the first connecting passage. The first connecting passage is so arranged that the squish flow passes through in front of the opening of the first connecting passage for decelerating the combustible mixture stream forced into the auxiliary combustion chamber via the first connecting passage at the time of the compression stroke.

Abstract: The invention relates to a swirl-chamber Diesel engine. A swirl-chamber Diesel engine is disclosed which has a piston formed with a curved groove at its crown and in which a communicating passage, between a main combustion and a swirl chamber, connects tangentially into the swirling air charge within the main combustion chamber. The curved groove has one end which, when the piston is on its top dead center, communicates with the swirl chamber through the communicating passage. It is curved generally along the swirling air charge and has an opposite end widened and arranged so as to direct the subsequent combustion gases toward the center of the main combustion chamber and permit them to diffuse thereabout. With this arrangement, the swirling air charge within the main combustion chamber and the penetrating force of the subsequent combustion gases entering into the main combustion chamber from the communicating passage are fully utilized to encourage the feeding of air to the fuel.

Abstract: A diesel cycle internal combustion engine having at least one cylinder with coplanar induction and exhaust valves and a precombustion chamber, in which the cylinder head is formed with a recess defining a combustion chamber with a projection on the crown of the piston, both the recess and the projection having a triangular cross section with respective upper surfaces being inclined at different angles from one another with respect to the longitudinal axis of the cylinder and respective side surfaces being inclined at substantially the same angle as one another with respect to the longitudinal axis of the cylinder.