Abstract: A manifold with air ducts that each include a downstream tube and two upstream tubes of which one is short and the other long, and a pivotable member with an acoustic through-bore between the upstream tubes and the downstream tube. When the member is in one of its end positions, one of the upstream tubes communicates with the downstream tube while the other upstream tube is sealed, and when it is in the other end position, the other upstream tube communicates with the downstream tube while the first upstream tube is sealed. The member is retractable and mounted in a housing and has two contactless-sliding side surfaces extending perpendicularly to the pivot axis of the member and frictionally engaging a respective one of the two side surfaces of the housing as the member is pivoted, whereby a laminar effect is generated which ensures good lateral sealing between the member and the housing. The manifold may be used in internal combustion injection engines, particularly for motor vehicles.

Abstract: A throttle valve body (1) including a flap (6) of which the side pivoting down or up on opening has a shoulder (17) on the flap surface facing upwards or downwards, respectively, defining a gradually widening cross-sectional area with the cylindrical (7) or frusto-conical (9) wall opposite the intake channel (3) through the housing (2). The side of the flap (6) which rotates up or down, respectively, on opening consists of a flat half disk of which the edge is , at first, opposite a tapered surface portion (14) with a complex shape to define a gradually widening cross-sectional area downstream from an inlet convergent (15,12) and upstream from an outlet divergent, respectively.

Abstract: The injector comprises a body (1) with a tip (2) exhibiting at least one calibrated outlet hole for jets of fuel as well as a skirt (25) for dispersing the fuel received in the form of jets, the skirt (25) being tubular and extending the body (1) to which it is fixed by its upstream part (14), and its downstream part (26) is formed, at least toward the downstream end, by at least one lateral wall thinned to a bevel (28) of thickness decreasing toward the downstream end as far as its downstream free edge in the form of a thinned blade (29). For preference, a concave notch turned toward the downstream end is formed in the free edge of each bevel, and each jet (J1, J2) of fuel from the two-hole injector strikes a region (30) on the internal face of a lateral wall of the skirt.Application to injectors, particularly multi-hole injectors, for automobile engines.

Abstract: The tubular skirt (12) in the partition between the air ports (2, 3) supports the injector (11) and forms two fuel passages (19) emerging in the ports (2, 3) between two opposed lateral walls (15) each thinned to a bevel (16) toward the downstream end with a free edge (17) in the form of a thin blade and with a notch having concavity turned toward the downstream end, a region (23) of the internal face of each lateral wall (15) upstream of the bevel (16) preferably being struck by at least one jet of fuel coming from the injector (11).Application to fuel-injected engines with two inlet valves per cylinder.

Abstract: The injector has two calibrated holes that deliver two jets of fuel into a zone into which there open out defined holes for passing air that are formed in a spray-generating adapter which is fed with air from a channel that is substantially at atmospheric pressure. The air-passing holes are distributed and oriented in such a manner that when steep pneumatic gradients are applied across the holes, at low or medium engine loads, one of the two sprayed fuel jets is deflected towards the other and mixes therewith to form a single jet confined in one only of the two intake manifold ducts, while at high engine loads both of them are fed. The injector is suitable for fitting to internal combustion engines fed by a multipoint injection installation and having two intake manifold ducts per combustion chamber.

Abstract: The admission manifold comprises a plenum chamber (1) downstream from a butterfly valve (2) and defining a resonance volume, an air inlet diffuser (6), an inlet (8) connected to the outlet from the butterfly valve (2), an air flow guide (11), and as many suction ducts (15) as there are cylinders in the engine, each duct feeding a corresponding cylinder thereof. The guide (11) serves to share admission air coming from the diffuser (6) between the ducts (15), and it is mounted downstream from the diffuser (6) in such a manner that the outlet (10) from the diffuser (6) opens out towards the tubular inlet (12) of the guide (11) which has an upstream edge spaced apart transversely from the downstream edge of the diffuser (6) by a permanent diaphragm. The diffuser (6), the guide (11), and at least an upstream portion of each duct (15) are housed inside the plenum (1). The manifold is applicable to feeding air to fuel injection internal combustion engines.

Abstract: A fuel injection device comprises electrically controlled fuel injectors, each opening into an air induction passage upstream of a respective intake valve of a combustion chamber. Each injector has an air-fuel mixture chamber. A throttle valve in the induction passage is constructed to close it when in a minimum opening position. An air line connects the induction passage to the mixture chambers and has an additional air electrically controlled valve. A supplemental electrically controlled valve is branched out of the line and opens into the induction passage downstream of the throttle valve. An electronic unit controls the injectors and the supplementary valve and opens the supplemental valve during cold start of the engine at low temperature and during operation of the engine as a brake at normal temperature, high speed and with the throttle valve closed.

Abstract: The butterfly valve assembly comprises a body formed with an admission duct and a disk shaped butterfly valve member of predetermined shape carried by a shaft that extends transversally to the passage and mounted for rotation in the body between a minimum opening position of the valve member and a maximum opening position. The duct has a cylindrical length whose cross-section matches with the shape of the butterfly valve member when the latter is in its minimum opening position. It further has respective zones upstream and downstream from the cylindrical length, along the paths followed by upstream and downstream edges of the valve member up to a determined opening angle thereof. Such zones are further defined by successive circular arcs centered on the axis of the admission duct and having radii that decrease going away from the cylindrical length along the axis.

Abstract: A carburettor for an internal combustion engine comprises a main fuel supply system for normal running, opening into a venturi in the induction passage of the carburettor, and at least one auxiliary circuit for supplying a flow of air/fuel mixture for low speed and low-load operation of the engine. The mixture control means for the circuits are carried by a distribution block arranged to be inserted and removably fixed in the part of the induction passage situated in the vicinity of the venturi.

Abstract: In a carburetor the fuel jet system opening into the intake pipe of the engine comprises an emulsion well supplied with air and fuel and a device for correcting the fuel/air ratio of the mixture supplied to the engine as a function of the amplitude of the alternating pressure variations caused by the suction of the engine in the intake pipe. The correcting device comprises a movable wall defining a chamber which communicates with the emulsion well and to which the alternating pressure variations are applied through an attenuator. The device adjusts the depression in the emulsion well for increasing or reducing the amplitude of the alternating component of the pressure which is communicated thereto from the opening of the fuel jet system according as to whether the acoustic matching of the carburetor-engine manifold assembly tends to produce an excessive or insufficient fuel/air ratio under high load.