Hydraulic drive apparatus

A hydraulic drive apparatus that supplies a working fluid to a travel motor and a loading actuator, the hydraulic drive apparatus comprising:

• a hydraulic pump that discharges the working fluid;
• a travel system hydraulic circuit that is connected to a first passage branching from a pump passage connected to the hydraulic pump and controls a flow of the working fluid to the travel motor;
• a loading system hydraulic circuit that is connected to a second passage branching from the pump passage and controls a flow of the working fluid to the loading actuator;
• a flow rate control valve that is interposed in the second passage and changes an opening degree of the second passage according to an opening degree signal;
• a travel-end pressure sensor that detects a travel-end supply pressure that is a pressure being supplied to the travel motor;
• a control device that controls, by outputting the opening degree signal to the flow rate control valve, the opening degree of the second passage according to the travel-end supply pressure detected by the travel-end pressure sensor;
• and
• a plurality of loading-end pressure sensors, wherein
• the loading system hydraulic circuit supplies the working fluid to each of a plurality of loading actuators including the loading actuator,
• each of the plurality of loading-end pressure sensors detects a pressure being supplied to a corresponding one of the plurality of loading actuators, and
• the control device controls the opening degree of the second passage according to the travel-end supply pressure detected by the travel-end pressure sensor and a plurality of loading-end supply pressures detected by the plurality of loading-end pressure sensors.

A hydraulic drive apparatus that supplies a working fluid to a travel motor and a loading actuator, the hydraulic drive apparatus comprising:

• a hydraulic pump that discharges the working fluid;
• a travel system hydraulic circuit that is connected to a first passage leading to a pump passage connected to the hydraulic pump and controls a flow of the working fluid to the travel motor;
• a loading system hydraulic circuit that is connected to a second passage leading to the pump passage via the first passage and controls a flow of the working fluid to the loading actuator;
• a flow rate control valve that is interposed in the second passage and changes an opening degree of the second passage according to an opening degree signal;
• a travel-end pressure sensor that detects a travel-end supply pressure that is a pressure being supplied to the travel motor;
• a loading-end pressure sensor that detects a loading-end supply pressure that is a pressure being supplied to the loading actuator;
• and
• a control device that controls, by outputting the opening degree signal to the flow rate control valve, the opening degree of the second passage according to the travel-end supply pressure detected by the travel-end pressure sensor and the loading-end supply pressure detected by the loading-end pressure sensor.