Evaporated fuel processing apparatus

Abstract

An evaporated fuel processing apparatus is provided with an initializer configured to increase a step number with which a stepping motor is rotated in a valve closing direction, when there is an initialization request for the blocking valve and tank pressure of the fuel tank is in a predetermined pressure range near atmospheric pressure, in comparison with when the tank pressure is out of the predetermined pressure range.

What is claimed is: 
     
       1. An evaporated fuel processing apparatus including: a canister containing adsorbent for adsorbing evaporated fuel generated in a fuel tank; a vapor passage connecting the canister and the fuel tank; a tank pressure sensor configured to detect tank pressure of the fuel tank; and a blocking valve disposed in the vapor passage, wherein the blocking valve is open closed when a stroke amount is less than a predetermined amount, and the blocking valve is closed open when the stroke amount is greater than or equal to the predetermined amount, wherein
 the blocking valve has a stepping motor configured to adjust the stroke amount, and said evaporated fuel processing apparatus comprises an initializer wherein
 in response to an initialization request to move the blocking valve in the valve closing direction to a predetermined initial position, the initializer is configured to set a step number to a first or second specified number with which the stepping motor is rotated in a valve closing direction, and said second specified number having a greater absolute value than the first specified number; 
 wherein if the tank pressure of the fuel tank is in a predetermined pressure range close to atmospheric pressure the step number is set to the second specified number and if the tank pressure is out of the predetermined pressure range, the step number is set to the first specified number.