Construction Machine

A construction machine comprising:

• an automotive vehicle body (2, 4);
• an engine (10) that is mounted on said vehicle body (2, 4);
• an exhaust gas purifying device (18) that is provided in
• an exhaust side of said engine (10) and includes a filter (21) for trapping particulate matter in an exhaust gas emitted from said engine (10);
• and
• a regeneration device (22, 41) that burns the particulate matter trapped in said filter (21) in said exhaust gas purifying device (18) to execute regeneration treatment of said filter (21),
• said regeneration device (22, 41) including:
• a first calculating unit that estimates a trapping quantity of the particulate matter trapped in said filter (21) based upon at least a differential pressure (ΔP=P1−P2) as a difference between pressure (P1) in an inlet side and pressure (P2) in an outlet side of said filter (21);
• a second calculating unit that estimates a trapping
• quantity of the particulate matter trapped in said filter (21) based upon at least a rotational speed (N) of said engine (10), a fuel injection quantity (F) and an exhaust gas temperature (GT);
• and
• a regeneration determining unit that determines whether or not the regeneration treatment is executed using a first estimated trapping quantity (H1) estimated by said first calculating unit and a second estimated trapping quantity (H2) estimated by said second calculating unit, characterized in that:
• said regeneration determining unit is configured to include a low-rotational time processing unit that makes the determination using only the second estimated trapping quantity (H2) estimated by said second calculating unit when said engine (10) is in a predetermined low rotational condition or using the first estimated trapping quantity (H1) estimated by said first calculating unit in the point in time where said engine (10) becomes in the predetermined low rotational condition, and
• said regeneration determining unit is configured to make the determination using both the first estimated trapping quantity (H1) estimated by said first calculating unit and the second estimated trapping quantity (H2) estimated by said second calculating unit when said engine (10) is not in the predetermined low rotational condition.