GB655727A - Improvements in or relating to fuel-systems for internal-combustion engines - Google Patents

Abstract

655,727. Regulating; spray carburetters. ROLLS-ROYCE, Ltd. June 1, 1948, No. 14831. [Classes 7(iii) and 7(vi)] [Also in Groups XXVI and XXIX] The fuel flow to an engine is corrected by a device responsive to variations in fuel temperature. In Fig. 3 fuel entering at 33a is delivered by a rotary pump 35 to an orifice 40, controlled by a valve 39 moved in one direction by a diaphragm 42 subject to the pressure drop across metering orifices 45, 46, and in the opposite direction by a centrifugal governor 38 carried by the pump rotor and flows from the orifice 40 through the metering orifices 45, 46 to chamber 43 containing the outlet 33b. The orifice 46 is controlled by a needle valve 48 carried by capsule 49 in a chamber 50 connected by a pipe 51 to the engine intake pressure or supercharger delivery pressure, some of the capsules 49 being evacuated and the remainder open to atmospheric pressure. The orifice 45 is controlled by a needle valve 52 connected to a lever 53 pivoted at both ends to thermometric devices comprising liquid-filled capsules 54, 57 connected respectively to a bulb 55 in the air intake pipe 56, and to a bulb 59 in the fuel pipe 60 leading to the inlet 33a, the flow through orifice 45 being decreased as the air temperature increases, and increased as the fuel temperature increases. In a modification, Figs. 1 and 2, a pump 16 with a constant pressure byepass valve 20 delivers to a metering pump 17 connected by pipe 17a to a chamber 25, Fig. 2, the outlet 19a of which leads to an injection nozzle 14. The outlet of pump 16 is connected by a pipe 22 to a chamber 24 connected to the chamber 25 by an orifice 26a in a sliding spring-loaded plate 26 carried by an annular capsule 29 open internally to the supercharge pressure through a pipe 23. A needle valve 31 controlling the orifice 26a is carried by a capsule 32 responsive to the fuel temperature. If the boost pressure increases the plate 26 is moved to the right to increase the size of orifice 26a, the fuel supply to the engine being thereby increased by fuel flowing from chamber 24 to chamber 25, and if the fuel temperature increases the valve 31 is moved to the left to increase the fuel supply. As applied to a suction carburetter, Fig. 4, having a nozzle 62 delivering atomized fuel into the induction pipe 61, the fuel being supplied from a chamber 64 through an orifice 65 to a space 63 where it is mixed with air entering through a passage 66, the orifice 65 is controlled by a needle valve 65b, actuated by a capsule 73 subjected to intake air pressure or boost-pressure, and is formed in a plate 65a movable by a capsule 76 in accordance with variations in fuel temperature. In a modification a float chamber feeds a main nozzle through a submerged jet and an auxiliary nozzle through a second jet controlled according to fuel temperature by a valve actuated by a capsule immersed in the fuel in the float chamber. As applied to a gas-turbine engine, Fig. 6, comprising a swash-plate pump 92 delivering through a throttle valve 94 to the burners 96, the pump delivery is controlled by a servo-piston 98 moved in response to the opening and closing of an orifice 102<SP>1</SP> by a valve 104, loaded by a spring 109 and controlled by the pump outlet pressure acting on a piston 114 and atmospheric pressure acting on a capsule 110, and a capsule 115 immersed in the fuel in chamber 103 varies the force of the spring 109 in accordance with variations in fuel temperature.