Pump nozzle for air-compressing injection internal combustion engine

Claim 1

A pump nozzle for an air-compressing internal combustion engine, the pump nozzle including a nozzle body means, a nozzle needle arranged in the nozzle body means, a mechanically actuated pump piston means for delimiting a pump working space, an inlet bore means operatively connected with the pump working space for feeding fuel to the nozzle needle, return bore means for returning leakage fuel, and a control means for influencing a delivery of fuel by the pump nozzle, characterized in that a discharge bore means communicates with the return bore means, the control means includes a valve means longitudinally displaceably guided in a chamber means arranged in a flow path of the inlet bore means at a position upstream of the pump working space for controlling a pressure of fuel in the pump working space, means are provided for actuating said valve means in accordance with a rhythm of the engine and for controlling an opening of the discharge bore means so that, with an increase in fuel pressure, said valve means is displaced into a closed position separating the inlet bore means from the pump working space, said control means are operable to displace the valve means to an open position by opening of the discharge bore means, and in that a substantially uninterrupted throttle bore is provided in the valve means for operatively connecting the inlet bore means with the return bore means by way of the discharge bore means when said discharge bore means is open, and in that the valve means includes a forward part which projects into the inlet bore means in a cross-section-reducing manner when the valve means is in the open position.