| 摘要 |
A control pressure switching valve (57) is disposed between a displacement regulator (26) and a pressure control valve (44). The control pressure switching valve (57) is switched between a control position (j), in which a load sensing control pressure (PLS) is permitted to be outputted from the pressure control valve (44) to the displacement regulator (26), and a control release position (k), in which the load sensing control pressure (PLS) to be outputted to the displacement regulator (26) is reduced to a prescribed low pressure value. When the regeneration of a filter (19) is determined to be necessary, the controller (61) switches the control pressure switching valve (57) to the control release position (k). When the load sensing control pressure (PLS) is reduced to the low pressure value with the control pressure switching valve (57) switched to the control release position (k), the displacement regulator (26) increases a delivery displacement of a hydraulic pump (13), thereby increasing rotational load of an engine (10). |
