The utility model discloses a generator set
fuel tank anti-vacuum valve which comprises an outer vent valve body, a sealing ring, a movable pressing plate, a spring and an inner vent valve body, the outer vent valve body comprises an outer vent
pipe, an air inlet and outlet reversing chamber and a guide cavity, and the inner vent valve body comprises an inner vent
pipe and a connecting sleeve. The connecting sleeve is inserted into the guide cavity to coaxially and hermetically connect the outer vent valve body and the inner vent valve body, an outlet of the outer vent
pipe is connected with the
air filter device through the
evaporation pipe, and the inner vent pipe is connected with a vent of the
oil tank through the
evaporation pipe; the movable pressing plate is arranged in the guide cavity in a reciprocating sliding mode and comprises a pressing plate
flange and a center air guide pipe, the sealing ring is arranged on one side of the pressing plate
flange in a sleeving mode, the spring is arranged between the other side of the pressing plate
flange and the connecting sleeve, and the spring is used for pushing the movable pressing plate and the sealing ring to be dynamically connected with the end face of the air inlet and outlet reversing chamber in a sealed mode; the
small hole is used for exhausting air outwards during exhausting, the sectional area of the air inlet can be rapidly enlarged during air suction, the vacuum negative pressure phenomenon in the
oil tank is avoided, and the
oil tank of the generator set is protected.