摘要 |
<p>A hydraulic drive device including a swing control system capable of accelerating it to a stationary state without any jerky swing operation at the time of starting of the swing operation, providing high energy efficiency, forming a stable swing system, and preventing a cost and space from increasing due to provision of additional circuits or complicated problem with circuit configuration from occurring, wherein a pump control device (18) is installed so as to control a discharge flow so that a pump discharge pressure becomes higher by a specified value than the max. load pressures of actuators (2 to 6), pressure compensating valves (12 to 16) are formed so that pressure differences between the discharge pressure of a hydraulic pump (1) and the max. load pressures of the actuators (2 to 6) are set as target compensating pressure differences, respectively, a load dependent characteristic which reduces the target compensating pressure differences when a load pressure rises is provided to the pressure compensating valve (12) of a swing section, and the load dependent characteristic is set so that a flow characteristic simulating the HP constant control of a swing motor can be obtained.</p> |