Construction machine

Abstract

A regeneration device performs regeneration of a filter by burning particulate matter trapped by the filter of an exhaust gas purifying device. The regeneration device is configured to perform two types of processing, that is, automatic regeneration processing for automatically performing regeneration not on the basis of an operation by an operator and manual regeneration processing for performing regeneration by notifying an operator to manually perform the regeneration and by performing the regeneration on the basis of an operation by the operator. The automatic regeneration processing makes determination on whether or not to perform regeneration on the basis of an estimated trapping amount (H) estimated from an engine rotational speed (N) and a fuel injection quantity (F). The manual regeneration processing makes determination on whether or not to notify the operator on the basis of a differential pressure (ΔP) of the particulate matter removing filter.

1 . A construction machine comprising:
 a vehicle body ( 2 ,  4 ) which an operator gets on board;   an engine ( 10 ) mounted on said vehicle body ( 2 ,  4 );   an exhaust gas purifying device ( 18 ) having a filter provided on an exhaust side of said engine ( 10 ) and trapping particulate matter in an exhaust gas exhausted from said engine ( 10 ); and   a regeneration device ( 22 ,  41 ) for regenerating said filter ( 21 ) by burning the particulate matter trapped by said filter ( 21 ), characterized in that:   said regeneration device ( 22 ,  41 ) is provided with automatic regeneration determining unit for determining whether or not said regeneration is to be automatically performed and manual regeneration determining unit for determining whether or not notification is to be made to said operator to manually perform regeneration;   said automatic regeneration determining unit estimates a trapping amount of the particulate matter trapped by said filter ( 21 ) on the basis of at least a rotational speed (N) of said engine ( 10 ) and a fuel injection quantity (F) and determines whether or not automatic regeneration is to be performed on the basis of whether the estimated trapping amount (H) is at a trapping amount threshold value (T 1 ) set in advance or more; and   said manual regeneration determining unit determines whether or not a signal for notifying manual regeneration is to be outputted on the basis of whether a differential pressure (ΔP=P 1 −P 2 ) which is a difference between a pressure (P 1 ) on an inlet side and a pressure (P 2 ) on an outlet side of said filter ( 21 ) is at a differential pressure threshold value (T 2 ) set in advance or more.   
     
     
         2 . The construction machine according to  claim 1 , wherein
 assuming that an erosion boundary value of an estimated trapping amount which becomes a boundary at which said filter ( 21 ) erodes or not is a trapping amount boundary value (X), said trapping amount threshold value (T 1 ) is set to a value smaller than said trapping amount boundary value (X) allowing for an error that can be caused between said estimated trapping amount (H) and an actual trapping amount.   
     
     
         3 . The construction machine according to  claim 1 , wherein
 assuming that an erosion boundary value of a differential pressure which becomes a boundary at which said filter ( 21 ) erodes or not is a differential pressure boundary value (Y), said differential pressure threshold value (T 2 ) is set to a value smaller than said differential pressure boundary value (Y) allowing for an error based on detection accuracy of a pressure sensor ( 24 ,  25 ) for obtaining said differential pressure (ΔP).   
     
     
         4 . The construction machine according to  claim 1 , wherein
 said regeneration device ( 22 ,  41 ) is configured to execute automatic regeneration processing by said automatic regeneration determining unit and manual regeneration processing by said manual regeneration determining unit in parallel.   
     
     
         5 . The construction machine according to  claim 1 , wherein
 the automatic regeneration on the basis of the determination of said automatic regeneration determining unit is configured to burn said particulate matter by performing fuel injection for regeneration by a fuel injection device upon receipt of a signal outputted from said regeneration device; and   the manual regeneration on the basis of the determination of said manual regeneration determining unit is configured to burn said particulate matter by performing fuel injection for regeneration by the fuel injection device upon receipt of a signal outputted from said regeneration device by an operation by an operator on the basis of an output of a signal notifying the manual regeneration.   
     
     
         6 . The construction machine according to  claim 1 , wherein
 the automatic regeneration on the basis of the determination of said automatic regeneration determining unit is configured to burn said particulate matter by driving at least either one of an intake throttle valve provided on an intake side of said engine and an exhaust throttle valve provided on an exhaust side in a direction of throttling a passage of said throttle valve upon receipt of the signal outputted from said regeneration device; and   the manual regeneration on the basis of the determination of said manual regeneration determining unit is configured to burn said particulate matter by performing fuel injection for regeneration by a fuel injection device upon receipt of a signal outputted from said regeneration device by an operation by an operator on the basis of an output of a signal for notifying the manual regeneration.