Fuel injection system

Claim 1

A fuel injection system for internal combustion engines comprising a suction tube in which a metering member and an arbitrarily actuatable throttle valve are disposed in series with one another and wherein said metering member is displaced by flowing air depending on the air flow rate in opposition to a resetting force a fuel supply line, a metering valve disposed in said fuel supply line said metering valve including a movable valve member, an actuating element connected to said metering member for displacing said movable valve member for the purpose of metering out a fuel quantity in proportion to the air quantity, said metering valve including a pressure chamber into which projects an effective face of said movable valve member of said metering valve, means for supplying fuel to said pressure chamber in said metering valve for producing a resetting force on said effective face of said movable valve member whereby a metering operation is carried out under a constant pressure difference which can be varied as a function of the operating parameters of the internal combustion engine, a regulatory valve means, said regulatory valve means including movable valve elements, having first and second sides arranged to adjust a pressure difference at the metering valve such that the first side is biased by fuel pressure downstream of the metering valve and the second side is biased by pressure in a control pressure line wherein said control pressure line is connected to the regulating valve and said pressure chamber in said metering valve into which projects the effective face of the movable valve member and wherein the pressure in said control pressure line may be varied by varying the pressure difference of at least a first throttle by means of an electromagnetic valve which is disposed in said control pressure line and which is controllable as a function of a plurality of operating parameters and wherein the electromagnetic valve is connected to simultaneously vary the pressure difference at the metering valve and alter the resetting force to the movable member.