| 摘要 |
<p>Before a large amount of PM is deposited in a filter, an exhaust gas cleaning system for a construction machine regenerates the filter to avoid a decrease in output due to the exhaust gas pressure rise occurring immediately before the filter is regenerated, and to reduce the likelihood of unusual increases in the internal temperature of the filter due to the combustion of the PM, associated with the execution of the regeneration, and consequential thermal damage to the filter.
After prior actuation of an automatic regeneration selecting switch 38b to an ON position, when a gate lock lever 22 is raised to a second position B and a key switch 5 is actuated to an OFF position, if a value that a differential pressure sensor 36 has sensed (i.e., a differential pressure across the filter 32) is greater than a second predetermined pressure P2, a controller 4 conducts engine speed control to a predetermined rotating speed Na suitable for the regeneration, then enters forced regeneration automatically, and burns off the PM. When the value sensed by the differential pressure sensor 36 decreases below a first predetermined pressure P1, the regeneration is terminated automatically and the engine 1 is stopped.</p> |
