GB1403259A - Fuel injection control systems - Google Patents

Abstract

1403259 Fluid-pressure servomotor systems BOWLES FLUIDICS CORP 12 Sept 1972 [17 Sept 1971] 42380/72 Heading G3P [Also in Division F1] A fuel injection system is controlled by the pressure of air in a receiver 15 situated in the engine manifold 10 to receive air from a jet 13 to which the pressure of the supply is varied in accordance with at least one variable. In the preferred embodiment, the manifold pressure Pm is fed through restrictors A5, A9, Fig. 5, preventing sonic flow to a fluidic amplifier 18 having an output P4 which varies non-linearly with Pm and corresponds to fuel/air ratio. P4 is modified in accordance with engine temperature by a bleedoff valve A3 connected to a bi-metallic element 19 and in combination with manifold pressure P1 sensed by a bellows 23 and a pressure corresponding to manifold temperature sensed by a second bi-metallic element 21 determines the pressure of the supply through fixed and variable restrictors A6 and A7 to the nozzle 13. The pressure in the receiver 15 is a function of the nozzle pressure and the flow in the manifold and is amplified by cascaded amplifiers 25 ... 27 to provide an output P5 which is fed into a turther series of amplifiers 31 connected to capacitors V1, V2 and through diodes D1 ... D4 to inputs P8, P9 which receive timing pulses generated by a drum 32 rotating at half the speed of the engine. The output P7 from the amplifiers is thus made to correspond to fuel delivery per stroke and operates an injection pump 45 through a further series of amplifiers (41), Fig. 7 (not shown) and a bellows coupled to lever 46, a valve (48) and resistors (24, R5) providing feed-back. The pulse in input P9 is fed through a diode (D5), Fig. 8 (not shown), and a capacitor (V3) to an OR/NOR gate (52) which switches to provide an output pulse when engine speed falls, the pulse being amplified to provide a pressure differential ql, q2 which forms a vortex in the manifold to throttle air-flow. The system pressure P+ is supplied by a pump and regulator 2.