GB656906A - Fuel pump - Google Patents

Abstract

656,906. Fuel-injection systems. ROOSA, V. D. Aug. 3, 1948, No. 20517. Convention date, Aug. 11, 1947. [Class 102(i)] [Also in Group XXIX] in a fuel-injection system, a feed pump 2 draws fuel through an inlet 5 and delivers to an outlet 8, the maximum pressure being controlled by a relief valve 15. The passage 8 is connected through an adjustable throttle valve 10, to a port 11 that enters the bore containing a rotary distributing valve 13 that has a number of radial ports 35 that connect consecutively with the port 11. The distributing valve has a diametral bore in which slide pistons 43 contacting rollers 44 that are actuated by the stationary cam 45. As the pistons reciprocate fuel is pumped to the groove 40 that is connected consecutively to a number of outlets leading to the engine cylinders. Adjacent the groove 40 is a second groove 67, Fig. 8, that after an injection, immediately opens the outlet to groove 68 that is connected to the low pressure side, e.g. through valve 71, to prevent drip. The rollers have pins that enter inclined grooves on plates 48 so that by rotating the plates, the extent of the outward movement of the plungers is limited. The cam 45 is connected to a tongue 53 that engages an inclined groove 55 in a piston 56 loaded by springs 57 and subjected to the delivery pressure of the feed pump 2 so that the time of injection is varied in accordance with the speed of the engine. The metering valve has a longitudinal groove 14 that connects the passages 8, 11, so that the flow is varied by rotation of the valve. In a modification, the slot is inclined and the valve may be rotated to vary the flow but is in addition spring- loaded and exposed to the feed pump pressure so that it is moved axially to reduce the flow and after closing the passages is arranged to connect the passage 8 to byepass. The metering valve may also be adjusted by a centrifugal governor 89 acting through levers 82 and 80.