GB688436A - Improvements in or relating to fuel supply apparatus for internal-combustion engines - Google Patents

Abstract

688,436. Fuel injectors; regulating. CUMMINS ENGINE CO., Inc. April 12, 1951 [June 14, 1950], No. 8521/51. , Classes 7 (iii) and 7 (vi). A fuel supply apparatus comprises a fuel pump delivering under substantially constant pressure, or a pressure varying with engine speed only, to a delivery line from which the fuel is distributed to the individual engine cylinders, the injection period being inversely proportional to engine speed, and is characterized by the delivery line between the pump and point of fuel distribution containing two adjustable throttle valves so interconnected that one valve moves towards closing position as the other moves toward opening position. A supply gear pump 24, Figs. 1 and 2, delivers to a float chamber 26 forming a supply reservoir for a constant pressure gear pump 32 having a delivery line 36 containing needle valves 37, 41, 43 and leading to a rotary distributer 35 controlling the connection to injectors 86. The valve 37 is a manually adjustable throttle valve and the valves 41, 43, are urged open by springs 72 and actuated by levers 70, 71 on a yoke pivoted at 63 and connected to the collar 61 of a centrifugal governor 50. As engine speed increases, the valve 43 moves toward closing and the valve 41 toward opening so that the valve 43 cuts off the fuel at excessive speeds and the valve 41 reduces the fuel flow at low engine speeds to counteract the increase in fuel supply due to the increased period of injection. The distributer 35 comprises a rotary plate 75, Fig. 2 having a radial passage 84 which is in constant communication with the fuel delivery passage 44 and engages in succession the passages 85 leading to the injectors 86 which include cam-actuated plungers 90 normally closing the fuel delivery ports 87. When used with a distributer, each plunger 90 is raised to open the port 87 slightly before the corresponding passage 85 is opened by the distributer, which controls the injection period. In a modification, Fig. 8, the distributer 35 is omitted and the fuel supplied to a pipe 95 common to all the injecters 96, the plungers 98 of which control the injection period. Non-return valves 88, Fig. 1, in the injectors 86 prevent air from the cylinders entering the fuel supply pipes. The governor 50 is carried on an engine-driven shaft 52, Fig. 2, which drives the distributer shaft 77 and the common shaft 100 of the pumps 24, 32, through bevel gears. At idling speed a groove 92 in the valve 41 opens an idling by-pass 91 and idling fuel is supplied through a groove 93 to a point downstream of the valve 41. A shut-off valve 45 is provided.