Injection nozzle

摘要

A fuel injection nozzle for supplying fuel to an internal combustion engine comprises an inwardly opening valve member which is urged by fuel under pressure against the action of a spring to allow fuel flow through an outlet opening. The valve member is surrounded by a sleeve member which is also subjected to the fuel pressure and engages the valve member to assist the initial movement thereof. The sleeve is slidable in a bore and the valve member in the sleeve. The working clearance between the wall of the bore and the sleeve and between the sleeve and the valve member are interconnected by radial bores or by making the sleeve from porous material such as sintered material.