a mechanism to maintain substantially constant the pressure of a fluid in a hydraulic circuit, in particular in the circuit of a fuel injection system for an engine to combustinternal ion

摘要

A device for maintaining substantially constant the pressure of a liquid in a hydraulic circuit comprises a chamber 2 inside which the liquid is circulated and which communicates with a drain hole 4; the passage of the liquid through the hole is controlled by member 16 having a substantially flat active surface 17 designed to rest on an annular surface portion 15 coaxial with the hole; the member 16 is thrust against the annular surface portion by a spring 8 acting on a deformable diaphragm 7 constituting a wall of the chamber; a ball 19 is located between the diaphragm and the member 16, which presents a concave surface opposite the active surface 17 designed to constitute a supporting seat for the surface of the ball, so as to enable the member 16 to move in relation to the ball, about any axis through the centre of the ball and so provide for substantially uniform supporting pressure between the active surface 17 and the annular surface portion 15. IMAGE