GB617890A - Improvements in the fuel injection system of an internal combustion engine and in the method of operating the same - Google Patents

Abstract

617,890. Supplying liquid fuel. TEXACO DEVELOPMENT CORPORATION. Dec. 18, 1945, Nos. 34259 and 34260. Convention dates, Dec. 14, 1944, and Oct. 18, 1945. Addition to 596,846. [Classes 7 (ii), 7 (iii) and 7 (vi)] In an engine operating according to the method of the parent Specification, which consists in forming a combustible air-fuel vapour mixture in a localized zone of the combustion chamber, e.g. by injection of the fuel into swirling air, and promptly spark-igniting the mixture to form a flame front which then ignites successive localized mixtures formed on continued fuel injection, the rate of fuel injection during each injection period is varied to form the successive localized mixtures at controlled fuel-air ratios. In one embodiment of the invention the fuel is injected into the air swirling in the combustion chamber 13 on the upstroke of piston 11 through an injection valve 44 controlled by a spring- loaded piston 63 subject through a conduit 67 to the pressure in the combustion chamber. At the beginning of the injection period the fuel pressure through conduit 36 raises the valve 44 to produce a localized fuel-air mixture which is ignited by a spark-plug 16, and as the pressure in the combustion chamber rises the piston 63 is raised, allowing the valve 44 to open further to maintain the localized fuel-air ratios substantially constant. The fuel is supplied at high pressure from pumps 101, 102 through check valves 118 and pipe 126, Fig. 4, to a pressure chamber 103, the pressure being maintained constant by a rack 135 which rotates the pump plungers through sleeves 134 and varies the position of helical edges 115 on the plungers co-operating with the spill ports 108. The rack 135 is controlled by a lever 161 connected to a piston 155, Fig. 5, subject to a constant air pressure through pipe 154 and balanced by the fuel pressure on the delivery side of the pumps acting through a passage 145 on a plunger 147. Fuel flows from the reservoir 103 through a pipe 170, passages 172, 183, 184, and thence to the pipe 23 when a timing valve 187 is lifted by a plunger 178. When the valve 187 closes, a bore 179 in the plunger 178 connects the space 183 and hence pipe 23 to the suction side of the pumps through passages 180, 181, 110, thereby helping the injection valve 44 to close quickly. The plunger 178 is actuated through an eccentrically pivoted lever 207 having an adjustable contact piece 199 from a cam-shaft 90 driving the pumps, rotation of the eccentric pivot 205 by levers 211, 213 connected to the throttle controlling the duration of injection. For maximum power the duration of injection is the same as one complete swirl of the air in the combustion chamber, and for fuel economy a conventional fuel injection nozzle having a constant rate of injection may be used at low power outputs. Alternatively, the device may be used with a fuel pump driven by a cam shaped to vary the rate of fuel injection through a spring-closed injection valve so that at the beginning of injection a localized combustible mixture is formed having a fuel-air ratio above the sparkignitable limit, the rate of injection being thereafter lowered to form localized mixtures of combustible but not spark-ignitable composition. The amount of fuel delivered by the pump is controlled by a rack which rotates the plunger through a sleeve, altering the position of a helical shoulder.