Patent ID: 6986341
Filing Date: 2006-01-17
Classification: F02M,Y10T

Abstract:
1. An apparatus for detecting fuel-vapor gas leaks, comprising: a valve for performing shut-off control of a vapor purge system that includes a canister that connects a fuel tank to an internal combustion engine; an open/close controllable reference orifice having a reference leak hole, said reference orifice for causing leakage from the vapor purge system through the reference leak hole; a jet pump for introducing outside air to the vapor purge system and for pressurizing the vapor purge system, by gasoline flow from a submerged fuel pump in the fuel tank; an internal pressure sensor for measuring internal pressure of the vapor purge system; and a storage device for storing as an initial curve, in a time series, pressure values taken by the internal pressure sensor in a state with the reference orifice alone opened and with pressurization from the jet pump carried out for a predetermined time period; wherein by comparing a time series in a pressure curve obtained by the jet pump pressurizing the vapor purge system in a completely shut-off state over the predetermined time period, with the time series in the initial curve, when the pressure curve is lower than the initial curve, the device for detecting fuel-vapor gas leaks judges that a leak is present.