Pressure regulator for a high-pressure rail of a fuel injection system

Abstract

The invention relates to a pressure regulator for a high-pressure ramp of a system for injecting fuel into an internal combustion engine, comprising a solenoid valve element () which receives an electromagnet (). The electromagnet controls a needle () that closes a valve seat () which is connected to a high-pressure inlet and opens into a discharge chamber (), said discharge chamber communicating with a liquid recirculation system () by means of outlet openings (). The rear face () of the solenoid valve element () receives a coil () which controls the opening process of an armature () that is rigidly connected to the needle () and is subject to a closing return spring (). The discharge chamber () is located on the front face () of the solenoid valve element () on the axis (XX) of the needle (), and the discharge chamber surrounds the needle. A cavity () passes through the discharge chamber, said cavity receiving an inlet valve element (), and a bore () which opens into the valve seat () passes axially through the inlet valve element. The discharge chamber () through which the needle () passes axially and the outlet openings () which are connected to the liquid recirculation system open transversally into a wall () in the discharge chamber () below the upper part () of the chamber. The regulator is characterized that the regulator comprises an annular expansion () of the discharge chamber () below the outlet openings () along the extension of a conical surface (), which forms the valve seat () and an annular dead volume (), above the surface () of the valve element (), which forms the base of the discharge chamber () and has the valve seat () in the center of the valve element.