Patent ID: 9546468
Date: 2017-01-17
CPC Classifications: E02F,F15B

Claim:
1. A hydraulic system of a construction machine, comprising: an electronic proportional pressure reducing valve (EPPRV) configured to control a flow rate, to which a maximum pressure is input as a control current value, and which is set to a minimum flow rate; a gear pump configured to provide pilot operation oil to the EPPRV; a shuttle valve configured to compare a pressure of first pilot operation oil passing through the EPPRV and a pressure of a flow rate control signal, and output second pilot operation oil having the greater pressure; a hydraulic pump of which a swash plate angle is controlled by the second pilot operation oil; and a pump control device configured to control the pressure of first pilot operation oil to be decreased from a maximum pressure by a predetermined inclination when the flow rate control signal is generated.