| 摘要 |
The present invention pertains to the use of a flow control valve as a valve positioned on a passage connecting a canister and a fuel tank in an evaporated fuel treatment device. The flow control valve maintains an opened state when a stroke amount, which is an axial moving distance of a valve movable part with respect to a valve seat, is within a predetermined range from an initial state, and is capable of maintaining the fuel tank in a sealed state. The evaporated fuel treatment device comprises: an internal pressure sensor for detecting a space pressure inside the fuel tank as the internal pressure; a valve open start position detecting means which obtains a second derivative value of the internal pressure detected by the internal pressure sensor after the opening operation of the flow control valve is started, and which detects a valve open position of the flow control valve as a valve open start position when the second derivative value is at least a first predetermined value; and a learning means which stores the valve open start position detected by the valve open start position detection means as a learned value when controlling the opening degree of the flow control valve. After the flow control valve starts the valve opening operation, the valve open start position, at which the fuel tank and the canister communicate with each other, is detected in consideration of an internal pressure change of the fuel tank, so that the valve open start position is accurately detected regardless of a variation in the environment under which the fuel tank is installed. |
