Patent ID: 7398764
Filing Date: 2008-07-15
Classification: F02M,F16K,Y10T

Abstract:
1. In a fuel metering unit for a fuel injection system for internal combustion engines with a high-pressure pump driven as a function of the engine speed, wherein the fuel metering unit has a control valve ( 11 ) that is actuated by an electromagnet ( 10 ) and has a valve piston ( 25 ), wherein the valve piston ( 25 ) is guided in a valve housing ( 22 ), wherein the valve piston ( 25 ) is embodied as sleeve-shaped and its inner chamber ( 26 ) contains a front end of a compression spring ( 27 ) that holds it in contact with an armature pin ( 14 ), and wherein a rear end of the compression spring ( 27 ) rests against a spring plate disposed in a valve bore ( 24 ) of the valve housing ( 22 ), wherein the wall of the valve housing ( 22 ) is provided with at least one radial control openings ( 32 ) that are formed and disposed so that the fuel quantity flowing through the fuel metering unit can be adjusted as a function of the stroke of the valve piston ( 25 ), the improvement comprising a shutoff sleeve ( 51 ) positioned at least partially in the inner chamber ( 26 ) of the valve piston ( 25 ), the valve piston ( 25 ) and the shutoff sleeve ( 51 ) constituting a shutoff device.