To provide a hydraulic driving device of a hydraulic work machine capable of preventing generation of surge pressure in a supply pipe for introducing pressure oil to a hydraulic actuator from a hydraulic pump.
This hydraulic driving device of the hydraulic work machine is constituted so that a delay processor 54b for calculating a stroke target command value Sb by applying delay processing to a stroke target command value Sa calculated by a stroke target command value computing element 54a, a maximum value selector 54c for selecting any of larger one of the stroke target command values Sa and Sb, a delay processor 55b for calculating the target stroke command value Sb by applying the delay processing to the stroke target command value Sa calculated by a stroke target command value computing element 55a, and a minimum value selector 55c for selecting any of smaller one of stroke target command values Sc and Sd, are arranged in a control device 53; and a rising response of an inflow flow control valve 33A is set faster than a bypass flow control valve 38; and a falling response of the bypass flow control valve 38 is set slower than the inflow flow control valve 33A.
TAKIGUCHI KAZUO
UENO KATSUMI
ONO TOSHIHIRO
AIHARA MITSUO
Ichiro Suzuki
Hirohiro Ichimura
Kazunori Satake