GB637702A - Fuel feeding and injection apparatus for oil burning internal combustion engines - Google Patents

Abstract

637,702. Supplying liquid fuel. CUMMINS ENGINE CO., Inc. Feb. 20, 1948, No. 5110. Convention date, April 26, 1943. [Classes 7 (iii) and 7 (vi)] [Also in Group XXVIII] Fuel is supplied from a metering device M, Fig. 19, through a pipe 90 feeding a number of injectors 26 each comprising a plunger 27 which is raised by a spring to open a port 34 allowing fuel to enter the space 29 into which air is forced on the compression stroke, and shortly before the end of compression a cam actuates the plunger 27 to inject the mixture through holes 31. The device is shown applied to a 12-cylinder engine wherein separate metering devices M, Ma each feed through a pipe 90 six injectors 26, the plungers 27 of which are actuated so that the times of opening of the ports 34 of each set of cylinders do not overlap. A low-pressure pump 49 with a return by-pass valve 62, supplies fuel from a tank to a float-chamber 56 from which fuel is fed by a highpressure pump 50, with a by-pass valve 76, through a pipe 70, and filter 72 to a surge chamber 73 connected by pipes 83, 83a to the metering devices M, Ma, each of which comprises a reciprocating valve 80 and metering pump 96, Figs. 3, 19. When a groove 81 on the valve 80 opens a port 84, fuel flows from the pipe 83 through a pipe 92 to the pump space 108, Fig. 17, from which the fuel is forced on reciprocation of a plunger 97 through a pipe 109, Fig. 19, communication of which with the pipe 90 feeding the injectors is controlled by a second groove 82 on the valve 80. The amount of fuel injected is controlled by varying the position of a valve 102, Fig. 17. having a groove 103, connected by ports 104 to the interior of plunger 97, through which fuel is spilled until the plunger 97 closes the groove 103. The valve 102 is controlled by a lever 122, Fig. 3, actuated by a centrifugal governor 115 and by a manual control. The lever 122 is rotatably mounted on a short eccentric shaft 1212, which is rotatable by a hand or foot actuated linkage, and the inner end thereof fits into a recess in a co-axial shaft 121 rotatable by the governor 115 and carrying a projection 1213 which engages an arm on the lever 122. On an increase of speed the shaft 121 is rotated anticlockwise and the valve 102 is raised by a spring 105 to reduce the amount of fuel delivered per stroke of the pump 95, rotation of the shaft 1212 by the manual control varying the fuel supply independently of the governor. The metering valve 102a supplying the other injectors is controlled by a lever 122a which is adjusted conjointly with the lever 122. The valves 80, 80a and pump plungers 97, 97a are reciprocated by cams 85, 85a, 99, 99a on a shaft 45 which also drives through a bevel gear 114 the governor 115, and through a gear 47 the pumps 49, 50. Any leakage past the injector plungers 27 escapes through passages 134, Fig. 19, to common return pipe 136 leading to the float chamber 56, and a manual shut-off valve 130 in the fuel delivery pipe of each injector enables faulty injectors to be traced.