INTERNAL PRESSURE CONTROL DEVICE FOR FUEL TANK AND TANK INTERNAL PRESSURE CONTROL VALVE

摘要

PROBLEM TO BE SOLVED: To control diffusion of evaporated fuel in a canister during the decrease of fuel temperature when an engine is stopped and prevent the occurrence of a trouble, such as blow-by of evaporated fuel. ;SOLUTION: A canister 10 is connected to a fuel tank 5 through a first evaporation passage 8 and a tank internal pressure regulation valve 11 is disposed in the evaporation passage 8. An atmosphere port 13 to introduce outside air is formed in the canister 10 and an electromagnetically-driven atmosphere intake valve 14 is disposed at the tip part of the atmosphere port 13. An ECU 20 controls opening and closing operation of the atmosphere intake valve 14 so that an internal pressure in a tank is fluctuated with a given width in a negative pressure region during the decrease of fuel temperature when an engine is stopped. In this case, through opening of the atmosphere intake valve 14, high speed outside air flows in the canister 10 and this constitution performs back purge of evaporated fuel and narrows an evaporated fuel diffusion layer in the canister 10.;COPYRIGHT: (C)1998,JPO