GB986111A - Improvements in fuel injection pumps - Google Patents

Abstract

986,111. Fuel injection pumps. SOC. INDUSTRIELLE GENERALE DE MECANIQUE APPLIQUEE. March 28, 1961 [March 30, 1960], No. 11246/61. Heading F1A. [Also in Division G3] Pistons 11 in a rotating shaft 2 are reciprocated by a fixed annular cam 14, the shaft carrying a centrifugal governor which varies the injection timing at low speeds and controls bypass passages 4, 5 at high speeds. A sleeve 6, having a liquid-tight fit on the shaft 2, is provided with a number of holes 7, 9, the number of holes being equal to the number of engine cylinders, four in this case. The passages 4, 5 are at about 120 degrees to each other and are inclined to the shaft axis in opposite directions. A control sleeve 22 operated by the governor slides over the sleeve 6 and shoulders 22a, 6a on the sleeves abut before a spring 29 is fully compressed. The thrust from springs 30 is transmitted by a pivoted lever 32 to the sleeve 6. Alternatively, a spring 30a may replace the springs 30, in either case the spring 29 being the weaker. A pin 35 slides in a groove 36 in the sleeve 6, the groove being inclined to the axis thereof, and a pin 37, fixed to the casing 17 slides in an axial groove 38 in the sleeve 22. The sleeve 22 has four passages communicating with the four holes 7, 9. During the delivery strokes of the pistons 11, fuel escapes through hole 7, until the sleeve 6 closes the passage 4 whereupon fuel is delivered to an injector, via conduits 1, 19, 20. Injection ceases when the hole 9 communicates with the passage 5 and during the suction stroke fuel enters the conduit 1 via conduits 15, 16 and possibly hole 9. This cycle is repeated four times during one shaft revolution in a four-stroke four cylinder engine. Rotation of the sleeve due to the pin 35 sliding in the groove 36, varies the timing and when the shoulders 6a, 22a abut and an increase in speed causes the member 24 to move the sleeves 6, 22 against the action of the springs 30, the fuel flow is reduced owing to the axial inclination of the passages 4, 5 reducing the angular displacement therebetween. To suit the operating characteristics of different engines the grooves 36, 38 may alternatively be wholly axial or partly inclined and the load on the springs 29, 30, 30a may also be varied either initially or when the engine is running in the case of spring 30.