| 摘要 |
PROBLEM TO BE SOLVED: To restrict a pressure at a fuel tank under a troubled state of a positive pressure relief valve mechanism from being increased more than an excessive pressure.SOLUTION: An evaporation fuel processing device comprises a motor valve 52, a positive pressure relief valve mechanism and a negative pressure relief valve mechanism. The motor valve 52 has a valve body 96 for opening or closing a vapor passage 31 for communicating a fuel tank 15 with a canister 34 so as to adjust a flow rate by an electrical control. The positive pressure relief valve mechanism opens a valve when a pressure at the fuel tank 15 is a predetermined positive pressure value or more. The negative pressure relief valve mechanism opens the valve when a pressure at the fuel tank 15 is a predetermined negative pressure value or less. The motor valve 52 is constituted in such a way that the valve body 96 is moved toward its opening direction with a pressure at the fuel tank 15 that is a valve opening pressure or more by a predetermined value of the positive pressure relief valve mechanism.SELECTED DRAWING: Figure 6 |
