Means for regulating the supply of liquid fuel to internal combustion prime movers

摘要

669,755. Fluid-pressure servomotor-control systems. LUCAS, Ltd., J. March 14, 1950 [March 25, 1949], No. 8179/49. Class 135. In mechanism for controlling the supply of liquid fuel to an internal combustion prime mover including a servo-mechanism which is controlled by the pressure drop across two throttles arranged in series in the fuel delivery to the combustion chamber and each operated by servo-mechanism, the one under the control of the blower delivery pressure and the other of a speed-responsive valve, a throttle is arranged between the speed-responsive valve and the servomechanism directly associated therewith, this throttle being actuated by means responsive to the pressure difference across the throttle controlled in accordance with the blown delivery pressure. The variable delivery swash-plate fuel pump i or other fuel regulating member is regulated by a spring-loaded servo piston a opposite sides of which communicate through a restricted orifice d. One side of the piston is supplied directly from the fuel pump and the other side is vented under the control of a hinged valve f operated by a spring-loaded piston or diaphragm j subject to the pressure in the fuel-pump delivery passage p and the pressure in a passage r leading to the combustion chambers. The passages p, r are separated by an intermediate chamber q, the entrance and exit of which are controlled by throttles n, o respectively. The throttle n is actuated by a servo-piston s similar to that already described. The piston s is controlled by a valve x on a bell-crank w. The piston s is loaded by a spring u abutting the bell-crank w. The valve x is actuated by a diaphragm or piston 5 subject to atmospheric pressure through a port 7 and to blower delivery pressure through a port 8. The other throttle o is similarly actuated by a spring-loaded servo-piston 9 controlled by a speed-responsive valve 14 co-operating with a vent passage 12, 13. The valve 14 is actuated by two diaphragms 17 connected by a member 16 and subject to the pressures on opposite sides of a manually-operable throttle 24 through passages 22, 23. A spring 19 tends to open the valve 14. The throttle 24 is arranged in an oil or other fluid circuit 25 containing an engine-driven pump 26. Between the passages 12, 13 is an intermediate chamber 15 containing a throttle 30 which co-operates with a seat 31. The throttle 30 is operated by a spring-loaded piston 32 subject, through passages 35, 36 to the fuel pressure drop across the throttle n. The throttle 30 regulates the rate of flow from the servo-cylinder 10 and thus prevents the response of the mechanism due to the movement of the speedresponsive valve 14 from being too rapid. Specification 577,016 is referred to.