| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel evaporation treatment device in which the inside of a fuel tank can be sealed while an internal combustion engine is stopped and a negative pressure can be also introduced to a fuel tank or a canister in the case of leak diagnosis without increasing the weight or cost or without generating rapid pressure fluctuation or rapid gas inflow in an intake passage during purge control.SOLUTION: When introducing a negative pressure to a fuel tank, an atmosphere opening/closing valve is opened (S402). Therefore, rapid pressure fluctuation or gas inflow is prevented in an intake passage. Since the atmosphere opening/closing valve is opened or a target negative pressure is present (S404), an excessive negative pressure or high pressure can be prevented and weight increase or cost increase is prevented as a result. After first negative pressure generation (S402, S403), second negative pressure generation (S406, S403) is executed. Therefore, while the atmosphere opening/closing valve is opened, even if a negative pressure is lacked, a sufficient negative pressure is generated by closing the atmosphere opening/closing valve and can be held by closing a sealing valve (S408). A configuration where leak diagnosis can be performed on the fuel tank and a canister by negative pressure introduction is maintained by the sealing valve, the atmosphere opening/closing valve and a purge control valve. |
