Patent ID: 6408824
Filing Date: 2002-06-25
Classification: F02D,F02M,F04B

Abstract:
A device for regulating a delivery pressure of a pump for feeding fuel to an internal combustion engine, the device comprising a solenoid valve having a supply conduit communicating with a delivery conduit of said pump, a drain conduit, a shutter between said supply conduit and said drain conduit, an electromagnet energized variably to control an armature controlling said shutter, a cutoff chamber for cutting off hydraulic pressure between said supply conduit and said drain conduit, said cutoff chamber being of such a volume as to reduce variation in said hydraulic pressure on said armature, wherein said armature comprises a cylindrical stem having a portion housed in said cutoff chamber and connected to said stem by a shoulder, said portion having a diameter smaller than a diameter of said stem to increase the volume of said cutoff chamber, and a fixed shield defining said cutoff chamber and having an opening in which said portion slides so as to eliminate a piston effect of the hydraulic pressure in said chamber on said stem.