Patent ID: 6579074
Filing Date: 2003-06-17
Classification: F04B

Abstract:
A diaphragm type fuel pump comprising:a fuel intake chamber; a fuel discharge chamber; a pump body having a fuel intake path communicating with the fuel intake chamber and a fuel discharge path communicating with the fuel discharge chamber; a diaphragm fixedly attached to the pump body via a bottom body; a pump chamber defined by the diaphragm and the pump body and communicating with the fuel intake chamber via the fuel intake path and the fuel discharge chamber via the fuel discharge path; a return path connecting the fuel intake chamber and the fuel discharge chamber; and a pressure regulating mechanism for returning fuel from the fuel discharge chamber to the fuel intake chamber via the return path when pressure in the fuel discharge chamber exceeds a predetermined value, wherein: the return path is formed in the pump body; a cavity formed within the pump body and being defined by an inner wall surface of the pump body, the cavity communicating with the return path via a first opening in the cavity and the return path communicating with a first one of a group consisting of the fuel intake chamber and the fuel discharge chamber, the cavity having a second opening communicating with a second one of the group consisting of the fuel intake chamber and the fuel discharge chamber, and the cavity having which is perpendicular to the diaphragm; and the pressure regulating mechanism is housed in the cavity, and is positioned inside an outer diameter of the pump chamber.