| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust purification device, for an internal combustion engine, capable of diagnosing a concentration of urea water.SOLUTION: An exhaust purification device for an internal combustion engine: injects urea water through an urea water injector after a lapse of a predetermined time since a regeneration process of a diesel particulate filter is started and an exhaust gas temperature increases to not less than a predetermined temperature (S10 to S16); detects a NOx concentration in exhaust gas with a plurality of NOx sensors (S18); calculates NOx purification efficiency on the basis of detection results (S20); calculates a concentration of the urea water from the NOx purification efficiency (S22); and warns a driver that the concentration of the urea water is less than a predetermined value when the concentration of the urea water is less than the predetermined value, for example 32.5% (S24 to S26). |
