Hydraulic drive device for industrial vehicle

A hydraulic drive device for an industrial vehicle comprising:

• a variable displacement pump that discharges hydraulic oil;
• a displacement control valve that controls the variable displacement pump;
• a power steering cylinder that is driven by the hydraulic oil discharged from the variable displacement pump;
• a power steering valve that is disposed between the variable displacement pump and the power steering cylinder to switch directions in which the hydraulic oil flows according to an operation state of a steering wheel;
• a loading cylinder that is driven by the hydraulic oil discharged from the variable displacement pump;
• a loading valve that is disposed between the variable displacement pump and the loading cylinder to switch directions in which the hydraulic oil flows according to an operation state of a loading operation lever;
• a first hydraulic oil passage that connects the variable displacement pump and the power steering valve and through which the hydraulic oil discharged from the variable displacement pump flows;
• a second hydraulic oil passage that connects the variable displacement pump and the loading valve and through which the hydraulic oil discharged from the variable displacement pump flows;
• and
• a pilot line that connects the loading valve and the displacement control valve,
• wherein
• the displacement control valve controls the variable displacement pump to increase displacement of the variable displacement pump when differential pressure between discharge pressure of the hydraulic oil discharged from the variable displacement pump and pilot pressure generated in the pilot line is smaller than a predetermined set pressure, and
• a spool of the loading valve is provided with a groove portion that forms a communication passage that makes communication between the second hydraulic oil passage and the pilot line at a neutral position of the loading valve when the power steering valve is located in a neutral position.