GB949666A - Carburetting apparatus - Google Patents

Abstract

949,666. Fuel injection carburetting apparatus. SOC. INDUSTRIELLE DE BREVETS ET D'ETUDES. April 24, 1962 [Oct. 9, 1961; Jan. 16, 1962; March 9, 1962], No. 15601/62. Heading FIB. Carburetting apparatus comprises a fuelcollection chamber 5, Fig. 1, a metering orifice 6 having an area variable in proportion to the variable cross-section area of the air inlet of a given portion of the air feed pipe 1a, fuel from chamber 5 under certain operating conditions being sucked by a pump 3 and injected under pressure into the air feed pipe downstream of the air inlet, and the fuel being driven through orifice 6 by a pressure difference equal to that existing between the upstream and downstream sides of the air inlet. Fig. 1. Fuel flows from a constant level chamber 11, which is in communication either with air intake 13 or atmosphere through a passage 12, through chamber 28 and metering orifice 6 into chamber 5. Pump 3, e.g. an engine driven or electric centrifugal or volumetric pump, supplies fuel under pressure to a distributor 34 and injection orifice 2. The area of orifice 6 is varied by a conical needle connected through rod 25 and cylindrical throttling member 8 to a spring-loaded piston 16 which is acted on by the suction in portion 1a. Relief conduit 20 may be connected to atmosphere. Air intake 13 may be connected to a filter or suction damper. Piston 16 may be replaced by diaphragm bellows. In another embodiment the throttling means consists of a pivoted disc connected to piston 16. Fig. 3. A disc throttle 10, mounted eccentrically, is connected to conical needle 24 through link 26 and rod 25 and an engine driven rotary distributor 34a connects the pump delivery successively to each of the conduits 35. In all embodiments an orifice 29 may be inserted between the chamber 5 and the pump 3 and chamber 5 communicates with portion 1a through a passage 14 having a cross-sectional area greater than either or both orifices 2 and 29. Fig. 6. An ejector device 3 which draws fuel from chamber 5 is operated by air from compressor 36 driven by an electric motor 50 fed by circuit 52 through contacts 53, 54. The contacts are opened by the suction existing in air pipe 1 or by the over pressure existing in conduit 39 when it is closed by a valve 42. The over pressure is transmitted through conduit 55 to chamber 56 having a spring-loaded diaphragm 57 connected to movable contact 54. Valve 42 is actuated by a spring-loaded diaphragm 44, in chamber 45 connected through conduit 46 to pipe 1. When small suctions exist in pipe 1, air is fed by compressor 36 through nozzle 38 to entrain the mixture of fuel and air from chamber 5 and inject it through orifice 2. With suctions above a predetermined value diaphragm 44 moves valve 42 to the right into the position shown to close conduit 39, fuel being sucked from chamber 5 by the suction in pipe 1. The over pressure in conduit 39 causes the contacts 53 to open thus stopping the compressor. A mixture of crank-case vapour from pipe 70 and air from the intake 13 is drawn through pipe 69 and orifice 68 into the nozzle at high speed to atomize fuel from conduit 40. When conduit 39 is cleared by valve 42, orifice 68 is closed and the strong suction existing in conduit 37 draws the crank-case vapour through the compressor 36, the oil content of the vapours being used partly to lubricate the compressor. Fig. 7. Compressor 36 is driven by a belt 60 from the engine water pump or dynamo. A disc 61 engages pulley 63, which is slidably mounted on compressor shaft 62, under the action of a spring-loaded suction operated diaphragm as in Fig. 6. The air inlet orifice 68 and the crank-case ventilation system may be used in conjunction with the clutch of Fig. 7. In another embodiment air is supplied to compressor 36 from a point downstream of throttle 7.