| 摘要 |
Provided is a DPF system that can perform DPF regeneration with an appropriate exhaust-injection amount even if the injection amount changes due to age-related deterioration or manufacturing variability of an exhaust-pipe injector. Said DPF system (10) is provided with: temperature sensors (26 and 27) that are provided at the entrance and exit of a DOC (23) and measure the DOC entrance temperature and DOC exit temperature during forced DPF regeneration; a surface-area-to-volume ratio determination means (29) that determines an exhaust-gas surface-area-to-volume ratio by measuring the flow rate of exhaust gas during forced DPF regeneration; and an injector diagnosis means (30) to which the temperatures measured by the temperature sensors (26 and 27) and the value determined by the surface-area-to-volume ratio determination means (29) are inputted. Said injector diagnosis means has: a heat-generation region determination unit (31) that determines whether or not the inputted values lie within a theoretical heat-generation region; and an actual-injection-amount diagnosis unit (32) that diagnoses the amount of decrease in the actual injection amount of an exhaust-pipe injector (24) if the temperatures measured by the temperature sensors (26 and 27) and the value determined by the surface-area-to-volume ratio determination means (29) do lie within the aforementioned theoretical heat-generation region. |
