Improvements in and relating to the regulation of the fuel supply in combustion engines

摘要

453,024. Fluid-pressure servomotorcontrol systems. ASKANIA-WERKE AKT.-GES. VORM. CENTRALWERKSTATT DESSAU UND C. BAMBERG-FRIEDENAU, 87, Kaiserallee, Friedenau, Berlin. Sept. 14, 1935, Nos. 25585 and 25586. Convention dates, Sept. 27, 1934 and July 29, 1935. [Class 135] In a fluid-pressure servomotor regulating the fuel supply to an internal-combustion engine such as an aircraft engine, and comprising a force-controller or relay responsive to changes in air density, the restoring impulse given to the restoring mechanism of the force controller by the servomotor varies in non-linear relation to the movement of the servomotor piston. In Fig. 1, an enclosed air chamber or bellows 2, located in or on the induction pipe changes its axial length according to the reciprocal value of the air density. This bellows, the stroke of which is reduced by the insertion of a fixed block 3, operates, through a bell-crank 6, on one end of a floating lever 8 pivoted intermediately to the control valve 14 and fulcrumed at its lower end G on a sliding cam 12 rigidly connected by rods 21, 22 to the servo-piston 17 controlling the fuel supply. The curve of the cam is of hyperbolic form, so that the movement of the piston 17 necessary to restore the control valve to the closed position shown is proportional to the reciprocal of the movement of the bellows 2. In cases where it is necessary to depart from exact proportionality in the fuel-air weight ratio, the cam 12 is constructed of laminµ 12', 1211 &c., Fig. 5, adjustable at right angles to the rod 21 and clamped thereon. Thus the curve of the cam may be adjusted to suit the fuel consumption curve of any particular engine. In a modification, a pin on a rod similar to the rod 21 engages an inclined slot on one end of the floating lever. The servopiston is urged to its zero position, corresponding to the starting position for the engine by an adjustable spring.