Abstract: The present invention relates to a method for reintroducing exhaust gas to the intake of an internal-combustion engine wherein, during the engine exhaust phase, part of the exhaust qas contained in combustion chamber (60) of cylinder (10) of the engine is fed, for an operating range of this engine, into a first fluid circulation circuit (C1) and the other part of said gas is discharged into an exhaust circuit. According to the invention, the method consists: during the engine intake phase, in cooling the exhaust qas fed into fluid circulation circuit (C1), in mixing the cooled recirculated exhaust qas with fresh supply air (AF) coming from engine supply circuit (44), in feeding the mixture of recirculated exhaust gas and of supply air into a second fluid circulation circuit (C2), and in cooling said mixture fed into second circuit (C2) prior to feeding it into combustion chamber (60).

Abstract: The present invention relates to a method for reintroducing exhaust gas to the intake of an internal-combustion engine wherein, during the engine exhaust phase, part of the exhaust gas contained in combustion chamber (60) of cylinder (10) of the engine is fed, for an operating range of this engine, into a first fluid circulation circuit (C1) and the other part of said gas is discharged into an exhaust circuit. According to the invention, the method consists: during the engine intake phase, in cooling the exhaust gas fed into fluid circulation circuit (C1), in mixing the cooled recirculated exhaust gas with fresh supply air (AF) coming from engine supply circuit (44), in feeding the mixture of recirculated exhaust gas and of supply air into a second fluid circulation circuit (C2), and in cooling said mixture fed into second circuit (C2) prior to feeding it into combustion chamber (60).

Abstract: Method for injecting fuel into the combustion chamber of a direct-injection internal-combustion engine, said chamber being delimited by the wall of a cylinder (10), a cylinder head (12) and a piston (22) comprising a bowl (26) inside which a teat (28) is arranged. According to the invention, the fuel is injected by means of an injection nozzle (24) allowing to obtain an engine injection sensitivity greater than or equal to 380 mm3/30 s and having a nappe angle (a1) less than or equal to 2 ⁢ Arctg ⁢ CD 2 ⁢ F , where CD is the diameter of cylinder (10) and F the distance between the point of origin of the fuel jets and the position of the piston corresponding to a crankshaft angle of 50° in relation to the top dead center (TDC).

Abstract: The invention relates to a method providing mixing of at least one gaseous fluid in the combustion chamber of a direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12), a piston (22) sliding in this cylinder, a fuel-injection nozzle (24), a combustion chamber delimited on one side by the upper face of piston (22) comprising a teat (30) pointing towards cylinder head (12) and arranged in a concave bowl (28), and intake means (14, 16) for at least one gaseous fluid, said intake means being designed so as to admit the gaseous fluid into the combustion chamber with a swirling motion or swirl.

Abstract: The present invention relates to a method of controlling the combustion by autoignition of a homogeneous fuel mixture for an internal-combustion engine comprising a combustion chamber in which a stage of slow oxidation of said mixture occurs prior to the combustion of this mixture.

Abstract: The present invention relates to a direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12), a piston (22) sliding, in this cylinder, intake means (14, 18) for at least one gaseous fluid, a multijet fuel-injection nozzle (24) comprising a fuel jet angle (&bgr;) and a fuel jet nappe angle (a1), and a combustion chamber delimited on one side by the upper face of piston (22), said face comprising a teat (36) pointing towards the cylinder head and arranged in a concave bowl (34).

Abstract: A direct-injection internal-combustion engine comprising at least one cylinder (1) with a cylinder head (2), a piston (5) sliding in the at least one cylinder, a gas intake and exhaust (3, 4), a combustion chamber defined on one side by the upper face (SP) of the piston (5), the face comprising a projection (7) pointing towards cylinder head (2) and arranged at the center of a concave bowl (8). According to the invention, engine comprises at least one injection nozzle (6) for injecting fuel with a nappe angle (a1) less than or equal to 2 Arctg2FCD, where CD is the diameter of cylinder (2) and F the distance between the point of origin of the fuel jets from injection nozzle (6) and the position of the piston corresponding to a crankshaft angle of 50° in relation to the top dead center (TDC).

Abstract: The present invention relates to a fuel injection control method for a direct-injection internal-combustion engine comprising at least an injector (20) of fuel jet nappe angle (a1), a cylinder (10), a cylinder head (12), a piston (18) sliding in this cylinder and connected to a crankshaft, and a combustion chamber delimited by wall (26) of the cylinder, cylinder head (12) and upper face (24) of piston (18). According to the invention, the method consists in determining a lower limit position (PL) of piston (18) below which wall (26) of the cylinder is likely to be wetted by the fuel jets coming from the injector, in determining the effective position of this piston, in locating this effective position of the piston in relation to the lower limit position and in adjusting the fuel injection parameters according to the effective position of the piston in relation to the lower limit position.

Abstract: Method for injecting fuel into the combustion chamber of a direct-injection internal-combustion engine, said chamber being delimited by the wall of a cylinder (10), a cylinder head (12) and a piston (22) comprising a bowl (26) inside which a teat (28) is arranged.

Abstract: The present invention relates to a direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12), a piston (22) sliding in this cylinder, intake means (14, 18) for at least one gaseous fluid, a multijet fuel-injection nozzle (24) comprising a fuel jet angle (&bgr;) and a fuel jet nappe angle (a1), and a combustion chamber delimited on one side by the upper face of piston (22), said face comprising a teat (36) pointing towards the cylinder head and arranged in a concave bowl (34).

Abstract: The present invention relates to a fuel injection control method for a direct-injection internal-combustion engine comprising at least an injector (20) of fuel jet nappe angle (al), a cylinder (10), a cylinder head (12), a piston (18) sliding in this cylinder and connected to a crankshaft, and a combustion chamber delimited by wall (26) of the cylinder, cylinder head (12) and upper face (24) of piston (18).

Abstract: A direct-injection internal-combustion engine comprising at least one cylinder (1) with a cylinder head (2), a piston (5) sliding in the at least one cylinder, a gas intake and exhaust (3, 4), a combustion chamber defined on one side by the upper face (SP) of the piston (5), the face comprising a projection (7) pointing towards cylinder head (2) and arranged at the center of a concave bowl (8). According to the invention, engine comprises at least one injection nozzle (6) for injecting fuel with a nappe angle (a1) less than or equal to 2Arctg2FCD, where CD is the diameter of cylinder (2) and F the distance between the point of origin of the fuel jets from injection nozzle (6) and the position of the piston corresponding to a crankshaft angle of 50° in relation to the top dead center (TDC).

Abstract: A process for controlling the quantity of fuel injected into a diesel engine comprising at least one cylinder includes the steps of determining the pressure variation (.increment.P) within at least one cylinder around a specific time of the engine cycle, for two successive cycles (C.sub.1, C.sub.2) having different injection characteristics; deducing therefrom the difference between the quantity of fuel actually injected into the cylinder and a theoretical quantity of fuel; and adjusting the injection parameters so as to balance in real time the quantity of fuel actually injected with the quantity of fuel that is to be theoretically injected. The process is preferably implemented during stabilized running of the engine.

Abstract: The invention relates to a process and a device for improving vaporization of a fuel injected into an internal-combustion engine so as to decrease harmful discharges in the exhaust gases . The engine comprises at least one cylinder (1) with an inlet pipe (6) , an exhaust pipe (4) , a secondary conduit (7) provided with a plug connecting for example the two pipes together so as to recycle towards the inlet pipe a fraction of the waste gases richer in unburned hydrocarbons. The process implemented here essentially consists in placing a fuel injector (9) in proximity to the intersection of inlet pipe (6) and secondary conduit (7) so as to take advantage of the high temperature of the recycled gases to vaporize fuel better and drive it towards the combustion chamber.

Abstract: The process essentially consists of reintroducing into the cylinder, during the phase of intake of the fresh gas, a more or less large part of the waste gas. It is achieved by providing each cylinder (1) with a branch pipe (7) communicating with the cylinder through an auxiliary inlet valve (8) whose opening period corresponds to the intake top dead center, and with the inlet pipe (6). A shutter or a plug (9) allows to control the flow of waste gas recycled at the intake according to the working conditions of the engine. A decrease in the harmful substances and an improvement in the engine efficiency can be obtained at the same time thereby.