Patent ID: 6622701
Filing Date: 2003-09-23
Classification: F02M

Abstract:
An accumulator fuel injection apparatus comprising:a high-pressure supply pump pumping fuel out of a fuel tank, said high-pressure supply pump pressuring and discharging the fuel; an accumulator storing therein the fuel discharged from said high-pressure supply pump; a fuel injector injecting the fuel stored in said accumulator into an internal combustion engine; a high-pressure fuel line extending from said high-pressure supply pump to said fuel injector through said accumulator; a relief valve having an inlet communicating with said high-pressure fuel line, an outlet, and a valve mechanism disposed between the inlet and the outlet, the valve mechanism being responsive to a rise in pressure of the fuel within said high-pressure fuel line beyond a given level to establish communication between the inlet and the outlet for relieving the rise in pressure of the fuel within said high-pressure fuel line; and a pressure pulsation absorbing mechanism disposed between the valve mechanism of said relief valve and a pressure pulsation source existing downstream of the outlet of paid relief valve, said pressure pulsation absorbing mechanism working to absorb a pressure pulsation propagated from the pressure pulsation source to the valve mechanism of said relief valve; wherein said valve mechanism includes a valve body in which the inlet of said relief valve is formed and a valve member movable to open and close the inlet selectively, wherein said relief valve includes a hollow cylindrical housing having a fuel hole formed between the inlet and the outlet, wherein said pressure pulsation absorbing mechanism includes a hollow screw which is fitted in an open end of the housing as defining the outlet of said relief valve and has formed therein an orifice working to absorb the pressure pulsation to be propagated from the pressure pulsation source to the valve mechanism, and further comprising a valve-urging mechanism disposed in the fuel hole of the housing which urges the valve member to close the inlet constantly; said hollow screw includes a sleeve and a flange head, the sleeve being retained within the open end of the housing and having formed therein a longitudinal chamber communicating with the fuel hole of the housing through an end of the sleeve, the flange head being formed on an end of the sleeve opposite the housing; and said orifice is implemented by a hole formed in the sleeve which extends perpendicular to the longitudinal chamber of the sleeve, the hole being smaller in diameter than the fuel hole of the housing and the longitudinal chamber of the sleeve.