CONSTRUCTION MACHINE

摘要

A control pressure switching valve (57) is provided between a capacity regulator (26) and a pressure control valve (44). The control pressure switching valve (57) is switched between a control position (j) at which load sensing control pressure (PLS) is permitted to be outputted from the pressure control valve (44) to the capacity regulator (26) and a control cancellation position (k) at which the load sensing control pressure (PLS) to be outputted to the capacity regulator (26) is decreased to a predetermined low-pressure value. When determining that the regeneration of a filter (19) is necessary, a controller (61) switches the control pressure switching valve (57) to the control cancellation position (k). When the control pressure switching valve (57) is switched to the control cancellation position (k) and the load sensing control pressure (PLS) is decreased to the low-pressure value, the capacity regulator (26) increases the discharge capacity of a hydraulic pump (13) to increase the rotational load of an engine (10).