GB1469164A - Timed pulsed fuel injection apparatus and method - Google Patents

Abstract

1469164 Liquid fuel injection systems S RHINE and M R SHOWALTER 4 March 1974 [8 March 1973] 9650/74 Heading F1B A fuel injection system comprises pump P which supplies fuel through valve V to an accumulator Ch 1, which discharges through rotary valves L 1 and L 2 into transfer accumulator Ch 2, which in turn discharges in sequence into each of a plurality of nozzle accumulators Ch 31, Ch 32, &c. The transfer accumulator is in fluid communication with either Ch 1 or one of the nozzle accumulators, but is never in communication simultaneously with both Ch 1 and a nozzle accumulator. Accumulator construction. Each accumulator consists of a rigid metal tube with holes in its walls and an elastomeric sleeve 2 secured at its ends by clamps 3 and 4. When fluid-pressure in the tube increases to the point at which the force exerted by the fluid exceeds the radially inward force due to the circumferential tension in the sleeve, any further increase in pressure results in expansion of the sleeve and an increase in the volumetric capacity of the accumulator. The injection system comprises a pump P which supplies fuel through a valve V to an accumulator Ch 1. The pressure drop across valve V is kept constant by a by-pass valve 24 mounted on a diaphragm 5 which is subject on its opposite surfaces to the pressures upstream and downstream of valve V. A relief valve 10 vents excess pressure. Accumulator Ch 1 is connected through rotary valves L1 and L2 to accumulator Ch 2. The path through valve L2 is always open and is shaped so that the flow-path between accumulators Chl, Ch2, and Ch31-Ch38 does not vary, regardless of which injector is receiving fuel. Fuel from accumulator Ch 2 is fed to a distributer L3 which successively connects with each of the accumulators Ch 31- - - - - - Ch 38. The relative angular positions of the rotary valve L1 and the distributer L3 are such that there is no communication between accumulators Ch 1 and Ch 2 during the time periods when accumulator Ch 2 communicates with any one of accumulators Ch 31 ---- Ch 38. Similarly, accumulator Ch 2 communicates with accumulator Ch 1 during the time periods when accumulator Ch 2 is not in communication with any of accumulators ' Ch 31 - - - Ch 38. Each of the last-mentioned accumulators is connected to an injection nozzle through a variable-area needle valve which controls the rate of flow through its associated nozzle so that the maximum flow-rate is quickly established, the fuel flow per degree of crank rotation then remains constant during the injection period and fuel flow is then terminated abruptly.