Fuel injection system functioning with pump/nozzles

A fuel injection system for internal combustion engines comprising a plurality of pump/nozzles a high pressure servo fluid source,

• (a) each said pump/nozzle including a servo piston, said servo piston including a large diameter portion and a small diameter portion, a pump work chamber below said small diameter portion and a servo pressure chamber above said large diameter portion, said servo pressure chamber receiving via a servo pressure line servo fluid from said high pressure servo fluid source for driving said servo piston;
• (b) a control fluid source, a, control apparatus for injection onset which controls the servo fluid from said servo fluid source to said servo pressure chamber for driving said servo piston in proportion to the stroke of the engine;
• said control apparatus including a hydraulically driven switchover valve, said switchover valve being driven by means of a control fluid delivered via a control line from said control fluid source, said switch-over valve being arranged in one switching position to direct said servo fluid from said high pressure servo fluid source to said servo pressure chamber above said servo piston and in another switching position is arranged to direct the servo fluid from said servo pressure chamber to a relief line, the instant of opening the servo pressure line leading from the high pressure servo fluid source to said servo pressure chamber of said pump nozzle is variable from a variation of the injection instant by said control apparatus;
• (c) a distributor device serving to control said control fluid and having a rotating distributor provided with a jacket face and distributor grooves disposed in said jacket face by means of which said source of control fluid is connected and thereafter disconnected during one rotation in sequence with and from said control lines leading to said switch over valves of said pump/nozzle;
• a fuel metering apparatus arranged to determine the fuel quantity of the fuel to be injected and storing up said fuel into said pump work chamber below said pump piston, characterized in that the flow of said control fluid to said switchover valve is controlled by means of said distributor device via control locations disposed between said distributor and a rotatable annular slide which surrounds said distributor, whereby injection onset is varied by rotation of said annular slide by means of a servomotor, and wherein said fuel metering apparatus includes a supply volume controllable positive-displacement piston pump.