Liquid Metering Valve Mechanisms and Fuel Injection Systems

摘要

1,159,796. Spray carburetters. PETROL INJECTION Ltd. and H. E. JACKSON. Dec. 21, 1966 [Dec.24, 1965], No.54794/65. Heading F1B. Fuel supplied by pump 12, Fig. 1, at a pressure varying with engine speed flows to injectors 8 through a metering system comprising two variable metering orifices A1, A3, and a pressure operated check valve A2 with adjustable loading spring, the devices A1, A2, A3, being adjusted by a common control. The fuel from pipe 1 after flowing through restriction Al, passes to the main pipe 2A leading to the injectors and to a return pipe 23 leading to the return circuit 10 containing a vapour separator 16. Devices A2, A3, are in one branch 26 of the return circuit in parallel with a second branch 29 containing a fixed restriction A4, the two branches combining at 31 upstream of a check valve 9A in the pipe 10 leading to a valve 17 maintaining a predetermined back-pressure in the return circuit. The valves A1, A3, each comprise a rotatable sleeve 66, Fig. 6, with a metering notch 67 therein, the sleeves being adjusted simultaneously by cams 94, 95, on a shaft 96 connected to the throttle linkage. A third cam 97 also actuates a yoke 102 to adjust the loading spring of check valve A2. The fuel supply to injectors 8 increases with increasing engine speed for any particular throttle opening at a first rate up to the pressure at which check valve A2 opens and then increases at a lower rate. At idling valve A1 is closed and the fuel flows through a by-pass 1B, 2B, containing a valve 34 operated by fuel pressure so as to close at speeds above idling the fuel in the pipe 1B then flowing through check valve 9B to the return pipe 10.