| 摘要 |
The present invention relates to an exhaust gas purification system for a construction machine, which can avoid the reduction in output due to an increase in the pressure of exhaust gas immediately before regeneration by performing regeneration of a filter prior to the deposition of a large quantity of PM in the filter, and can reduce the possibility of an abnormal increase in a temperature inside the filter caused by the combustion of the PM during regeneration or of the combustion of the filter caused thereby. An operator may place the entire manipulation tools in a not-manipulated state for a fixed period of time with an engine (1) started inside an operation room between work with a hydraulic excavator, such as during a rest inside the operation room. At this time, a controller (4) for monitoring the state controls the revolutions per minute (RPM) of the engine (1) at a pressure detection value of a differential pressure detecting device (36) higher than a second fixed pressure (P2), and then initiates forcible regeneration in order to combust and remove the deposited PM in the filter, when the not-manipulated state continues for a fixed time (Ta). In addition, the controller terminate the automatic regeneration and restores to a general engine control state when the pressure detection value of the differential pressure detecting device (36) becomes lower than a first fixed pressure (P1). |
