Diaphragm pressure regulator

Abstract

A diaphragm pressure regulator is proposed which serves to regulate a fluid pressure in a system having fluid flowing through it, and in particular to relate the fuel pressure in a fuel injection system. The diaphragm pressure regulator includes a valve diaphragm, which cooperates with a valve seat. The valve diaphragm separates a spring chamber having a system pressure spring from a system pressure chamber, into which the valve seat, which is axially displaceable and is supported in an axial bearing point, protrudes and which communicates with the fluid to be regulated. The end of the valve seat remote from the valve diaphragm is embodied as a valve plate and protrudes into a collection chamber, in which it opens a sealing seat toward a return flow line to a greater or lesser extent. A closing pressure spring engages the valve plate and urges the valve seat in the direction of the valve diaphragm. When the valve diaphragm is lifted up from the valve seat, fluid flows via a conduit in the valve seat into the collection chamber. A throttle gap is provided between the system pressure chamber and the collection chamber, by way of which throttle gap fluid can flow out to the collection chamber, when the fluid system is shut off, until such time as the valve plate is pressed in a sealing fashion against the sealing seat and blocks the return flow line, which takes place below a predetermined fluid pressure.