Patent attributes
A work machine including a specific actuator that supplies hydraulic fluid from a plurality of hydraulic pumps includes: first and second hydraulic pumps communicating with a first hydraulic actuator; a first control valve returning hydraulic fluid delivered by the first hydraulic pump to a tank; and a load detection section that detects a load on the first hydraulic actuator. A control valve drive section drives the first control valve such that a communication area between the first hydraulic pump and the tank is enlarged corresponding to an increase in the load on the first hydraulic actuator; and a flow rate control section, during supply of the hydraulic fluid from the first and second hydraulic pumps to the first hydraulic actuator, controls to reduce a delivery flow rate of the first hydraulic pump corresponding to an increase in the load on the first hydraulic actuator.