GB1424069A - Apparatus for controlling fuel flow to an internal combustion engine - Google Patents

Abstract

1424069 Controlling fuel supply to engines J ZEYNS and H ENNEKING 18 April 1973 [15 May 1972] 18794/73 Heading F1B [Also in Divisions G2-3] Air-flow to an I.C. engine is measured by a device 11 and the amount of fuel distributed to the injection valves associated with the working cylinders is controlled in response thereto. The flow cross section of an opening 15 is controlled by the air-flow in channel 18 and a fuel pump 1 supplies fuel thereto by way of a flow resistance 7, the fuel then passing via a differential pressure regulator 25 and a constant pressure regulator 29 to the tank 3, a reduced control pressure downstream of the opening 15 being supplied to one side of each of membranes 61 of metering regulators 53, the membranes also being acted on by adjustable force exerting means (springs 193) and by fuel supplied to their opposite sides via metering resistances 55 to control the flow of this latter fuel to the injection valves (not shown). The constant pressure regulator 29, responds by means of a bellows 71 to ambient pressure and temperature to vary the mixture strength. Regulation of mixture strength for cold starting is provided by valves 67 and 79 responsive to bi-metallic regulators 70a, 70b on the engine 70. Valve 67 is also controlled to close when acceleration pedal 68 is fully depressed, so that laminar resistance 7a is connected into fuel control pipe 9 to lower the pressure therein and so cause mixture enrichment by reducing the pressure above membranes 61. Fuel supply to the injection valves is controlled by magnetic valve 65. The baffle 19 acted on by the airflow may be provided with an opening (81), Fig. 5 (not shown), whose flow cross section may be varied by a plate (83). A by-pass (89), Fig. 6 (not shown), may be provided around the baffle 19 and has a flap 91, which may be responsive to one of the bi-metallic regulators 70a, 70b. A turbulent resistance, 75, across which the pressure drop is proportional to square of the flow through it, is formed as an apertured plate and enables the mixture to be enriched as engine power increases. The laminar resistances 7, 7a and 55 (Fig. 4) comprise pistons 173, 177 connected by rod 175 and slidable in fluid tight manner in a sleeve 171. The gap between the rod and the sleeve is about 80Á and can be made temperature-dependent by making the rod and sleeve of materials of different expansion coefficients e.g. steel and brass. Movement of the piston-rod-piston unit along the sleeve alters the flow resistance of the unit by altering the length of the laminar section of annular gap 191.