Choke pin nozzle

Claim 1

A choke pin nozzle for diesel engines, the nozzle including a nozzle housing, a nozzle body disclosed in said housing, a fitted nozzle bore provided in the nozzle body, a nozzle needle including a choke pin axially guided in the nozzle bore, a helicoidal compression spring means for urging the nozzle needle into a closed position, and a spring chamber means for accommodating the compression spring means, characterized in that an intermediate piston is disposed between the compression spring means and the nozzle needle, the nozzle body includes a guide bore means for sealingly axially guiding the intermediate piston, an axially extending bore means is provided in the intermediate piston and communicates with the spring chamber means, the intermediate piston terminates in a bearing face means adapted to sealingly cooperate with an upper surface of the nozzle needle, means are provided on the intermediate piston for enabling the intermediate piston to be displaced with respect to the nozzle needle, said guide bore means is widened in an area of a stroke zone of the intermediate piston so as to form an annular chamber, the annular chamber is in selective communication with the axially extending bore means in dependence upon a position of the bearing face means relative to the upper surface of the nozzle needle, the intermediate piston has a reduced diameter in an area of the bearing face means, the guide bore means is disposed in a separate neck portion interposed between the nozzle body and the nozzle head, the nozzle head includes a connection means enabling a connection with a nozzle conduit, a fuel leak connection means is provided and is in communication with the spring chamber means, a conduit means is provided for communicating the spring chamber means with the annular chamber, and in that a check valve means is interposed in the conduit means for controlling the flow therethrough, said check valve means opening in a direction of the annular chamber.