VAPORIZED FUEL TREATING DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To measure concentration of fuel steam without purging vaporized fuel in a canister actually. SOLUTION: In this vaporized fuel treating device, gas stream is generated by a pump 23 in a measuring passage 21 having restriction 22 on the halfway and difference in pressure between both ends of the restriction 22 is detected by a differential pressure sensor 45. Change-over valves 31, 32 are provided in the measuring passage 21 to realize a first concentration measuring condition in which the measuring passage 21 is opened at both ends and gas flowing in the measuring passage 21 is turned into the atmospheric air. The measuring passage 21 is communicated with the canister 13 at both ends to realize a second concentration measuring condition in which gas flowing in the measuring passage 21 is turned into air-fuel mixture containing vaporized fuel from the canister 13 to compute concentration of fuel steam based on the detected difference in pressure in the first concentration measuring condition and the detected difference in pressure in the second concentration measuring condition by an ECU 41. COPYRIGHT: (C)2006,JPO&NCIPI