GB884952A - Improvements in carburation devices for internal combustion engines - Google Patents

Abstract

884,952. Spray carburetters. SOC. INDUSTRIELLE DE BREVETS ET D'ETUDES. May 25, 1960 [May 30, 1959], No. 18505/60. Class 7(3). A carburetter, working normally by continuous injection of fuel into the induction pipe 1 of an internal combustion engine down stream of a throttle valve 2 provided in the pipe 1, in which a pressure regulator 10 varies the pressure of the fuel in the conduit 12 through which the fuel is fed to an injection orifice 13 (or orifices) according to the variation of the air flow rate through the pipe 1 comprises means capable, when the engine is idling, of transforming the pressure regulator 10 into a constant level fuel chamber, so that fuel is then introduced through the orifice T3 into the pipe 1 under the effect of suction existing in the pipe 1. As shown, the pressure regulator 10 comprises a chamber 21 provided with a top edge 22. A cover 23, capable of being applied upon this edge, is guided by a red 24 and is constantly urged upwards by a spring 25. A lever 29, pivoted at 30, and connected by a rod 31 to a diaphragm 32 which forms the movable wall of a chamber 33 connected by ducts 34, 35 to a Venturi 5, is constantly applied against cover 23. Fuel is supplied to chamber 21 from a tank 6 by means of a pump 7, and passes through a conduit 12 to the injector 13 which is located in a chamber 17 that communicates with the induction pipe 1 by an orifice 18. The overflow of fuel from chamber 21 flows through channel 14 back to tank 6. Chamber 17 normally communicates with the atmosphere, possibly through the air intake 15, by means of an orifice 19, the cross-section of which is varied by a conical member 47 attached to a lever 45 which is rotatable about an axis 46 by means of a sliding rod 48 actuated by a lever 49 rigid with the throttle 2. A spring 50 tends to rotate the lever 45 in an anticlockwise direction. The chamber 17 also communicates with the atmosphere through orifices 28, 26, the cross-section of orifice 28 being varied by a screw 27. The cover 11 housing the regulator is connected to either the atmosphere or the air intake 15 by means of channel 14, tank 6 and duct 16. A distributing valve 36, pivoted at 37, and applied against a plane surface into which ducts 34, 35 open at 38 and 39, varies the suction existing in chamber 33 with respect to that in Venturi 5. The distributer is provided with a hole 41 open to the atmosphere or connected to air intake 15, and a groove 40 having a branch 40a which co-operates, when the throttle is partially closed with an orifice 42, in the plane face, which is connected to a duct 43. The hole 41 ensures that there is no suction in chamber 33 when the throttle is closed, alternatively a closing valve 52 cooperating- with an orifice 53 in duct 34 may be operatively connected to lever 45. A device, in the form of a diaphragm 54, biased to the left by a spring 59 is provided to ensure that when the engine is running at high speeds and the throttle is closed, more fuel will be supplied by the suction in Venturi 5 pulling the diaphragm 54 and thus rod 57 to the right moving the cover 23 downwardly towards edge 22. When the throttle is open, duct 35 is connected to duct 34 and the suction in Venturi 5 forces cover 23 against the edge 22 by means of diaphragm 32, rod 31 and lever 29. Thus fuel is supplied under pressure into pipe 1, and is deflected by a surface 20. When the throttle is closed fuel flows over the edge 22, cover 23 having moved away from the latter as chamber 33 is now open to the atmosphere. Also chamber 17 is no longer open to the atmosphere and fuel is sucked into pipe 1 by the suction downstream of the throttle. Modifications are described including, chamber 21 at 45 degrees to the vertical, chamber 17 vented to the atmosphere or not by means of the fluid pressure in conduit 12, conical member 47 in the shape of a double conical member (the two cones base to base), a supplementary chamber added to chamber 33, and a device operatively connected between the throttle and lever 29 ensuring a sudden increase in the fuel pressure on opening the throttle.