| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a diagnostic device for an EGR system, specifying the portion of an EGR system and specifying the condition of the portion, even if there is a temporal change caused by adhesion of PM (soot). <P>SOLUTION: This diagnostic device for the EGR system includes: an EGR flow passage allowing an exhaust pipe to communicate with an intake pipe; a flow rate measurement device attached to the EGR flow passage and measuring an EGR gas flow rate; an EGR temperature measurement device attached to the inside or the vicinity of the flow rate measurement device and measuring the temperature of the EGR gas; and an EGR gas flow rate control valve controlling the EGR gas flow rate. The diagnostic device includes: a profile measurement means measuring the temperature profile of the EGR gas temperature changed according to a change in the valve opening of the EGR gas flow rate control valve and the flow rate profile of the EGR gas flow rate; and a diagnostic means specifying the portion of the EGR system, and diagnosing the condition of each position, based on the temperature profile and flow rate profile. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
