Fuel injection apparatus for spark plug-ignited internal combustion engines

Claim 1

In a fuel injection apparatus serving a spark plug-ignited internal combustion engine operating on fuel continuously injected into the air intake tube thereof, said apparatus being of the type that has (a) an arbitrarily operable butterfly valve disposed in said air intake tube, (b) an air sensor disposed in said air intake tube spaced from said butterfly valve, said air sensor being displaceable by and as a function of the air quantities passing through said air intake tube, (c) a fuel quantity distributor valve for metering the fuel quantities to be injected, (d) means connecting said air sensor with said fuel quantity distributor valve to effect metering of said fuel as a function of the deflection of said air sensor, (e) means supplying a return force affecting said air sensor in opposition to the force exerted thereon by the flow of intake air, said means supplying said return force includes a control plunger operatively connected to said air sensor and cylinder means accommodating said control plunger and containing liquid under pressure exerting said return force on said control plunger, the improvement comprising A. a pressure control valve hydraulically connected to said cylinder means for varying the pressure of said liquid in said cylinder means, said pressure control valve including a spring the bias of which affecting said pressure in said cylinder means, B. a first temperature-responsive control element sensing the engine temperature and causing an increase in the bias of said spring as the engine temperature increases, C. a second temperature-responsive control element opposing, when unheated, the operation of said first temperatureresponsive control element, and D. a separate heater means operatively coupled to said second temperature-responsive control element for heating the same causing discontinuance of its opposing effect on said first temperature-responsive control element.