Patent GB-990990-A (GB)
Title: Improvements in or relating to a device for regulating the supply of fuel injected into an internal combustion engine
IPC: F02M59/30
Filed: 1963-05-06
Abstract: 990,990. Regulating I.C. engines. SOC. D'ETUDES ET D'APPLICATIONS INDUSTRIELLES COMMERCIALES ET IMMOBILIERES INTER-TECHNIQUE. May 6, 1963 [May 10, 1962; Sept. 18, 1962; Nov. 29, 1962], No. 17757/63. Heading F1B. In an I.C. engine fuel-injection regulating device the output regulation means 21, Fig. 1 is connected to the moving element of an air jack V whose variable volume chamber is connected via a jet 4 to a negative pressure inlet 5 which opens divergently towards the downstream side of a Venturi throat 7 in the air induction pipe 10, so that a decrease in the induction pressure at inlet 5 causes a movement of regulation means 21 in opposition to the action of spring 16 to cause a decrease in the output of a volumetric fuel pump P. The piston 2 is connected by a link 11, pivoted at 12 and 13, to a lever 14 which is pivotable about a fixed pivot pin 15, and is connected by a link 20 to lever 21 which acts as a return abutment for varying the travel of fuel pump piston 22. Movement of lever 21 regulates clearance j between piston 22 and a push rod 24 actuated by driving cam 25. Jack V is connected by pipe 26 to a to a cylinder 27 in which a thermostat 30, exposed to the water cooling circuit, acts against spring 29 to move slide 28 to obturate ports 31, 32, 33. Operation. For starting and idling, throttle 9 is closed and lever 14 and piston 2 are in the positions shown in broken line so that clearance j is small and pump P gives full throttle output. After starting the pressure in the inlet decreases and jack V returns lever 14 and lever 21 to the positions shown in full line, so that clearance j increases and the volume of fuel injected decreases. When the engine is cold, the thermostat 30 causes slide 28 to uncover ports 31, 32, 33 to cause a drop in the negative pressure in jack V thus causing an increase in the volume of fuel injected. In a modification, the link 20 is connected to a rack which meshes with pinion sections of a pair of fuel pump pistons. In a further modification, the angular movement of lever 14 acts through a screw thread or helical ramp to bear against the lever 21 or against the rack in the first modification. In another embodiment, lever 14, Fig. 4, acts through a cam 14 and roller 42 on lever 21, the cam profile 41 giving the desired law of variation in the pump output as a function of engine speed. In a further embodiment, ambient sea level pressure existing within reservoir 50, Fig. 7, acts against spring 60 to move piston 55 to the left when the ambient air pressure is reduced. This causes the piston 55 to close the port 56 which decreases the pressure existing in chamber 46 causing further movement of piston 2 to the left thus decreasing the fuel supply. Piston 55 also uncovers port 57 causing the air, no longer entering the engine partly through the port 56 to enter the engine through ports 54 and 57 to maintain the idling speed. The reservoir 50 also performs the function of a temperature corrector when it is placed in the circulation of air feeding the engine.