Fuel injection apparatus for externally ignited internal combustion engines operating on continuously injected fuel

Claim 2

In a fuel injection apparatus for the continuous injection of fuel into the suction tube of an internal combustion engine, said suction tube containing an arbitrarily operable butterfly valve, said apparatus being of the known type that has a. an air sensor member forming part of an air sensor means disposed in said suction tube spaced from said butterfly valve, said air sensor member being deflected by the flow of intake air as a function of the intake air quantities, b. lever means forming part of said air sensor means and being attached to said sensor member, c. means generating a return force affecting said air sensor means and opposing the deflecting force of the air flow, said return force being independent from the deflected position of said air sensor member, said means including a pressure chamber filled with pressurized liquid supplying said return force, d. a fuel metering and distributor valve having a movable valve member exposed to the pressure of said liquid and operatively connected to said lever means to be displaced thereby against said return force to an extent proportionate to the deflection of said air sensor member for maintaining constant the fuel-toair ratio for any given return force, e. a control valve means varying said return force, said control valve means having a movable valve member loaded by a primary spring and f. means varying the bias of said primary spring as a function of at least one engine parameter, the improvement comprising a secondary spring connected to said movable valve member of said control valve means and means for varying the bias of said secondary spring as a function of the air ratio in the exhaust gas of said internal combustion engine, wherein said control valve means is formed as a flat seat valve and its movable valve member is constituted by a diaphragm, and wherein said primary spring exerts a force on one side of said diaphragm and said secondary spring exerts an opposing force on the other side of said diaphragm.

Claim 3

In a fuel injection apparatus for the continuous injection of fuel into the suction tube of an internal combustion engine, said suction tube containing an arbitrarily operable butterfly valve, said apparatus being of the known type that has a. an air sensor member forming part of an air sensor means disposed in said suction tube spaced from said butterfly valve, said air sensor member being deflected by the flow of intake air as a function of the intake air quantities, b. lever means forming part of said air sensor means and being attached to said sensor member, c. means generating a return force affecting said air sensor means and opposing the deflecting force of the air flow, said return force being independent from the deflected position of said air sensor member, said means including a pressure chamber filled with pressurized liquid supplying said return force, d. a fuel metering and distributor valve having a movable valve member exposed to the pressure of said liquid and opEratively connected to said lever means to be displaced thereby against said return force to an extent proportionate to the deflection of said air sensor member for maintaining constant the fuel-to-air ratio for any given return force, e. a control valve means varying said return force, said control valve means having a movable valve member loaded by a primary spring, and f. means varying the bias of said primary spring as a function of at least one engine parameter, the improvement comprising a secondary spring connected to said movable valve member of said control valve means and means for varying the bias of said secondary spring as a function of the air ratio in the exhaust gas of said internal combustion engine, said means for varying the bias of said secondary spring including an electromagnet having a solenoid and an armature displaceable by electromagnetic forces generated by said solenoid and means for energizing said solenoid, said secondary spring being in engagement with said armature with the bias of said secondary spring being varied as a function of the position of said armature.

Claim 4

In a fuel injection apparatus for the continuous injection of fuel into the suction tube of an internal combustion engine, said suction tube containing an arbitrarily operable butterfly valve, said apparatus being of the known type that has a. an air sensor member forming part of an air sensor means disposed in said suction tube spaced from said butterfly valve, said air sensor member being deflected by the flow of intake air as a function of the intake air quantities, b. lever means forming part of said air sensor means and being attached to said sensor member, c. means generating a return force affecting said air sensor means and opposing the deflecting force of the air flow, said return force being independent from the deflected position of said air sensor member, said means including a pressure chamber filled with pressurized liquid supplying said return force, d. a fuel metering and distributor valve having a movable valve member exposed to the pressure of said liquid and opEratively connected to said lever means to be displaced thereby against said return force to an extent proportionate to the deflection of said air sensor member for maintaining constant the fuel-to-air ratio for any given return force, e. a control valve means varying said return force, said control valve means having a movable valve member loaded by a primary spring, and f. means varying the bias of said primary spring as a function of at least one engine parameter, the improvement comprising a secondary spring connected to said movable valve member of said control valve means and means for varying the bias of said secondary spring as a function of the air ratio in the exhaust gas of said internal combustion engine, said means for varying the bias of said secondary spring including an electromagnet having a solenoid and an armature displaceable by electromagnetic forces generated by said solenoid and means for energizing said solenoid, said secondary spring being in engagement with said armature with the bias of said secondary spring being varied as a function of the position of said armature.

Claim 5

An improvement as defined in claim 2, wherein the means for varying the bias of said secondary spring further includes a first abutment against which said armature is pressed by said secondary spring in the de-energized condition of said solenoid and a second abutment against which said armature is pressed by electromagnetic forces in the energized condition of said solenoid.