Patent ID: 6145492
Filing Date: 2000-11-14
Classification: F02M

Abstract:
In an injection valve having a control chamber to be connected via an inlet throttle to a high-pressure accumulator for injecting fuel into an internal combustion engine, the control chamber to be further connected to a fuel tank via an unpressurized return line, the injection valve further having a nozzle seat and a movable nozzle body with nozzle needles for communicating with injection holes formed in the injection valve, a control valve, comprising:an axially movable valve body having a first operating surface adjoining the control chamber, said valve body having on a side opposite said first operating surface a sealing surface cooperating with a valve seat of the injection valve;an outlet throttle disposed in said valve body for connecting the control chamber to the unpressurized return line and dimensioned in comparison with the inlet throttle such that a pressure drop at the inlet throttle is greater than a pressure drop at the outlet throttle;said valve body having a valve chamber formed therein disposed opposite the control chamber and connected to the control chamber via said outlet throttle and further disposed in a flow direction downstream of said outlet throttle and upstream of said sealing surface; andsaid valve body further having a second operating surface defined by said valve chamber and acting in a fashion opposed to said first operating surface and being smaller than the first operating surface, said sealing surface of said valve body to be lifted from the valve seat for connecting the control chamber to the unpressurized return line via said outlet throttle, a pressure prevailing in the control chamber acting on the movable nozzle body having the nozzle needle for releasing and sealing the injection holes as the nozzle body moves.