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: A piston within the body of the valve is connected to an actuator and is integral with stops. After a first stroke of the piston from its position against the first seat, the first stops entrain second stops integral with a second piston, to entrain this with the first piston over a second stroke, from the position of application of the second piston to its seat. This feeds air-assisted injectors through the outlet over the first stroke, and in addition, over the second stroke to admit air through the outlet bypassing a throttle valve. Control of a single actuator allows the airflow to be regulated through each of the two outlets in succession.

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: The supply device with built-in pipework comprises an air distributor/manifold module with a casing and a base element made from plastic or metal and which are fixed to one another. The base element has pipework branches emerging in the casing and in a flange for fixing on to the engine. The casing houses sensors and members for controlling operating parameters of the engine as well as a fuel rail and its regulator supplying injectors which are trapped between the base element and the casing. Components of the air, fuel, ignition and electrical supply circuits are built into the pipework.

Abstract: A rotary throttle member for an internal combustion engine comprises a shaft and a butterfly valve member secured to a central length of the shaft. The shaft and butterfly valve member are single pieces of synthetic material. End portions of the shaft straddle the said central length. The central length has a uniform non-circular cross-section greater than that of the full end portion of the shaft situated on one side of the length. The shaft includes a cam for connection with and winding of a control cable, situated on the other end portion of the shaft. The butterfly valve member has a central hole of complementary cross-section of said central length and is fixed onto the central length.

Abstract: An idling circuit for a carburation device comprises an idling duct for supplying a primary air-fuel mixture downstream of the throttle and a fueled-air line having an adjustable cross-section for circulating an additional quantity of air and primary mixture from upstream to downstream of the throttle. A solenoid valve is energized by pulses having a duty cycle which is controlled so as to keep the engine speed near a set idling speed and so as to increase the amount of mixture supplied to the engine during deceleration at high speed.