| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an evaporative leak check system capable of carrying out evaporative leak check with high accuracy over a long period in a simple configuration. <P>SOLUTION: An ECU 4 drives a pump 11 while being closed between a first pump passage 43 and a tank passage 41, and then a pressure detected with a pressure sensor 13 is taken as a closing pressure (a). Thereafter, the pressure detected with the pressure sensor 13 just after being opened between the first pump passage 43 and the tank passage 41 is taken as an opened pressure (b). Thereafter, "a pump characteristic equation of the pump 11" is led from the closing pressure (a), the opened pressure (b), and " a flow rate characteristic equation of the first pump passage 43", Thereafter, the evaporative leak check system calculates a reference pressure (d) by obtaining an intersection point of "the pump characteristic equation of the pump 11" and "an orifice flow rate characteristic equation having a prescribed flow passage area". Thereafter, the evaporative leak check system drives the pump 11 for a prescribed time period, and then determines whether the evaporative leak is within an allowable range by comparing the pressure detected with the pressure sensor 13 with the reference pressure (d). <P>COPYRIGHT: (C)2012,JPO&INPIT |
