PRESSURE CONTROL APPARATUS OF FUEL TANK FOR VEHICLE

In pressure increasing control for raising a pressure within a sealed type fuel tank from an excessive negative pressure to a low negative pressure, an opening or closing operation of a sealing valve, when the interior of a vehicle is very quiet, would cause the working noise thereof to be transmitted to a passenger, thereby deteriorating the noise characteristic. In order to solve this problem, a control unit 32, when the pressure within a fuel tank 14 is below a predetermined negative pressure P VL near a saturated vapor pressure of the fuel and an interior noise level is equal to or greater than a threshold value, operates a sealing valve 28 to thereby raise the pressure of the fuel tank 14 to a normal negative pressure region P L to P U which is higher than the predetermined negative pressure P VL .