PULSATION DAMPING DEVICE FOR FUEL FEED SYSTEM

PURPOSE:To provide a pulsation dumping device which is prevented from lowering of pulsation damping function and leak of fuel to the outside, by incorporating a closed damper which is formed with a bellows made of a metal, being actuated so that pulsation of a fuel pressure is exerted on the interior of a delivery pipe to damp the pulsation. CONSTITUTION:A closed damper comprises a bellows 11, the cylindrical side of which is formed in a waveform shape by using a metal, plates 12 and 12 on both sides, airtightly joined to both ends of the bellows, a compression spring 13, providing a rebound force between the plates, a pipe 14, serving to hold the interior of a closed damper 10 in a vacuum state, or to airtightly hold it after the interior of the closed damper is filled with given gas, and a ball 15. As a fuel pressure exceeds a specified pressure, the plate 12 on the right of the closed damper is parted from a delivery pipe seat surface 1a, is then collided with a pipe end surface 14a, and prevents the bellows 11 from being deformed more excessively. The use of a bellows made of a metal prevents lowering of damping function due to penetration of fuel to the interior of the closed damper 11, and prevents leak of fuel to the outside even if the bellows is broken.