Abstract: The present invention relates to a method of controlling operation of an internal-combustion engine using a single-fuel or a multi-fuel combustion mode with at least one fuel type comprising a high octane number and a low energy density and at least another fuel type comprising a low octane number and a high energy density, a method wherein the energy required for the engine to operate in multi-fuel mode is provided by a combination of two fuel types.

Abstract: A method for detecting abnormal combustion in the combustion chamber of at least one cylinder of a spark-ignition supercharged internal-combustion engine includes: measuring a quantity linked with the combustion of the fuel mixture in the chamber, producing a signal whose amplitude depends on the amplitude of the measured quantity, comparing the amplitude of the signal produced with the amplitude of a threshold signal corresponding to the amplitude of a signal during combustion with engine knock, determining the presence of a rumble type abnormal combustion in the combustion chamber when the amplitude of the signal produced exceeds the amplitude of the threshold signal by a significant value.

Abstract: A method for controlling a supercharged engine, that includes determining an overlap of valves by opening a supercharged non-fuel-containing air inlet valve and closing an exhaust valve before the exhaust phase of an engine cylinder and in the vicinity of the top dead center (TDC), actuating a blocking means for blocking a supercharged non-fuel-containing air intake means to admit supercharged air flowing in the supercharged non-fuel-containing air intake means into a chamber to scavenge residual burned gases when a pressure of the supercharged non-fuel-containing air is greater than a pressure of the exhaust gases, and actuating the blocking means to shut off the supercharged air flowing from the supercharged non-fuel-containing intake means into the chamber when pressure of the supercharged non-fuel-containing air is less than pressure of the exhaust gases.

Abstract: The present invention relates to a method for detecting abnormal combustion in the combustion chamber of at least one cylinder of a spark-ignition supercharged internal-combustion engine, characterized in that it comprises: measuring a quantity linked with the combustion of the fuel mixture in the chamber, producing a signal whose amplitude depends on the amplitude of the measured quantity, comparing the amplitude of the signal produced with the amplitude of a threshold signal corresponding to the amplitude of a signal during combustion with engine knock, determining the presence of a rumble type abnormal combustion in the combustion chamber when the amplitude of the signal produced exceeds the amplitude of said threshold signal by a significant value.

Abstract: The present invention relates to a method of controlling operation of an internal-combustion engine using a single-fuel or a multi-fuel combustion mode with at least one fuel type comprising a high octane number and a low energy density and at least another fuel type comprising a low octane number and a high energy density, a method wherein the energy required for the engine to operate in multi-fuel mode is provided by a combination of two fuel types.

Abstract: A supercharged internal-combustion engine has at least two cylinders with a combustion cycle during which a cylinder (10) of the engine is in the intake phase with burnt gas scavenging in the vicinity of the top dead center (TDC) thereof while another cylinder is in the exhaust phase in the vicinity of the bottom dead center (BDC) thereof, the cylinders having at least one intake (12) with an intake valve (141, 142, 143, 144) and at least one exhaust (18) with an exhaust valve (201, 202, 203, 204). Controlling the engine includes carrying out scavenging of the burnt gases of the cylinder in the intake phase by a valve overlap stage by opening simultaneously its exhaust (201) and intake (141) valves, and controlling opening of exhaust valve (203) of the cylinder in the exhaust phase so that, during at least part of the overlap stage, the exhaust pressure (Pe) of the cylinder in the intake phase is lower than its intake pressure (Pa).

Abstract: The present invention relates to a method for controlling a supercharged engine comprising at least one cylinder (10), at least one supercharged fuel-containing inlet valve (20), a supercharged non-fuel-containing air inlet valve (28), and at least one exhaust valve (36). According to the invention, the method consists of: bringing about, before the exhaust phase of a cylinder, an overlap of the non-fuel-containing inlet valve (28) and exhaust valve (36), commanding an additional means (30) in order to admit supercharged non-fuel-containing air into said cylinder (10) to scavenge the residual burned gases, commanding said additional blocking means to close the supercharged non-fuel-containing air intake when the pressure of the supercharged non-fuel-containing air is less than that of the exhaust gases.

Abstract: A combustion method for a supercharged four-stroke engine having at least four cylinders includes a combustion cycle during which a cylinder of the engine is in the exhaust phase while another cylinder is in the supercharged air intake phase with a burnt gas scavenging stage. The start of the exhaust phase of the cylinder in the exhaust phase is shifted in relation to the start of the burnt gas scavenging stage of the cylinder in the intake phase.

Abstract: The present invention relates to a method of controlling a supercharged internal-combustion engine having at least two cylinders with a combustion cycle during which a cylinder (10) of the engine is in the intake phase with burnt gas scavenging in the vicinity of the top dead center (TDC) thereof while another cylinder is in the exhaust phase in the vicinity of the bottom dead center (BDC) thereof, the cylinders comprising at least one intake means (12) with an intake valve (141, 142, 143, 144) and at least one exhaust means (18) with an exhaust valve (201, 202, 203, 204).

Abstract: The present invention relates to a combustion method for a supercharged four-stroke engine having at least four cylinders (10) with a combustion cycle during which a cylinder of the engine is in the exhaust phase while another cylinder is in the supercharged air intake phase with a burnt gas scavenging stage.

Abstract: The present invention is a method of ignition advance correction of an internal-combustion engine according to the composition variation of the natural gas contained in a tank and supplying the engine. A methane number relative to the natural gas filling the tank is determined and an ignition advance correction value is deduced from the number. According to the invention, a correlation is established between the methane number described above, an air-fuel ratio R for a stoichiometric combustion and the gas flow variation required to reach a reference working point of the engine after the composition variation of this gas.

Abstract: The present invention relates to a method of locating the source of a knock, or more generally of a high-gradient self-ignition, appearing in a combustion chamber of an engine. According to the method, several pressure detectors are used, the pressure waves received by the detectors are recorded, the distance differences between the source of the knock and the various detectors are determined and the spatial location of the knock source in the chamber is deduced therefrom.

Abstract: A system intended for pressure supply of liquid fuel to at least one combustion chamber of an internal-combustion engine, includes a tank (1) intended for pressure storage of the liquid fuel, injectors (2) for pressure injection of the fuel into at least one combustion chamber, a line (3) between the tank (1) and the (pressure) injectors (2), a pump (4) placed in the tank (1) or on the line (3), a pressure regulator (5) placed in the tank (1) or on the line (3), and a capacity (canister) (6) placed on a by-pass (7) of the line (3) towards an intake system (A) of the engine and intended for gaseous fuel storage. The fuel injection is performed directly or not into the combustion chamber(s), and a solenoid value (8) for isolating the injectors (2) in relation to the tank (1) and are provided a drain (9) for draining the injectors (2), placed on the by-pass (7), upstream from the capacity (6).

Abstract: A direct-injection spark-ignition four-stroke internal-combustion engine includes a combustion chamber (1) delimited by a piston (10), a cylinder and a cylinder head, an intake pipe (2) associated with an intake valve (6), an exhaust pipe (3) with which an exhaust valve (7) cooperates, an ignition element (8) and a fuel injection element (9). According to the invention, the fuel injection element (9) is situated close to the ignition element (8), in the same half of the cylinder head as the exhaust valve (7), the half cylinder itself being placed toward the front of the vehicle. Fuel injection element (9) can be placed below the ignition element (8).

Abstract: A direct-injection spark-ignition four-stroke internal-combustion engine includes a combustion chamber defined by a piston, a cylinder with a cylinder head, an intake pipe associated with an intake valve, an exhaust pipe with which an exhaust valve cooperates, and a first ignition device situated close to intake valve. The engine further includes a fuel injection element situated close to the first ignition device, with the intake pipe, the fuel injection element, and the first ignition device being situated in the same half of the cylinder head. The fuel injection element may be placed below the first ignition device. A second ignition device may be positioned in the half of the cylinder head containing the exhaust valve.

Abstract: A direct-injection and spark-ignition 4-stroke internal-combustion engine having at least one combustion chamber (1) including a piston (2), a cylinder (3), a cylinder head (4), several intake lines (5) associated with intake elements (6), an exhaust line (9) cooperating with an exhaust valve (11), and an ignition device (7) positioned close to intake elements (6). The upper face of the piston (2) has a profile close to that of the lower face of the cylinder head (4), and the piston (2) has a recess (12) in the vicinity of the area into which ignition device (7) opens. A fuel injection element (8) is positioned in the vicinity of the ignition device (7), and one of the intake elements (6) has a longitudinal axis close to the longitudinal axis of the cylinder (XX').

Abstract: The present invention is a process for controlling the intake of a direct fuel injection four-stroke engine in at least two combustion chambers. A diferent intake for at least two cylinders or groups of cylinders is used in order to reduce exhaust emissions. A first cylinder or group of cylinders is operated with an air/fuel ratio greater than or equal to one, and a second cylinder or group of cylinders (21, 24) is operated in under-stoichiometric conditions.

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: The present invention relates to a controlled-ignition direct fuel injection, four-cycle internal combustion engine including a combustion chamber (3) in which at least two intake lines (31, 32) terminate through ports (21, 22, 23) and an exhaust line (5), each of which can be closed by a means such as a valve (41, 42, 6), at least one ignition means (7; 11), a means (9) for direct injection of fuel into said combustion chamber (3). According to the invention, the intake ports (21, 22) are diametrically opposite each other. In addition, at least one of ignition means (11) has an axis disposed perpendicularly to the outer surface of the fuel jet generated by injection means (9 ).

Abstract: The invention relates to a device for controlling the intake air of a spark-ignition four-stroke engine with direct injection of fuel into combustion chamber (1), comprising a main pipe (2) equipped with a throttling means (9), at least a first (3) and a second (4) intake pipe coming from main pipe (2) and opening each into combustion chamber (1), a pipe (7) for recycling the exhaust gases back to the intake equipped with a throttling means (8) and that opens downstream from the throttling means (9) of the main pipe and a means for controlling the air flow supplied to the combustion chamber. According to the invention, said air flow control means comprises a pipe (10) mounted as a bypass on said main pipe (2), around the throttling means (9) thereof, said pipe (10) having a section substantially equal to that of main pipe (2), and a means (11, 12; 14) allowing to seal at least said bypass (10) as a function of the running conditions of the engine.