Patent attributes
To provide a hydraulic circuit with a compact and simple structure while securing the amount of a hydraulic oil necessary for right and left running motors so as to prevent the limitation of a running speed. A first system has a changing valve for a right side running motor and a changing valve for a first actuator, and a second system has a changing valve for a left side running motor and a changing valve for a second actuator. The changing valves for the right side and the left side running motors and the changing valves for the first and second actuators are tandem-connected, respectively. A merging valve has a merging position to communicate first and second supply paths with each other and interrupt supply paths for right side and left side running, a merging position to communicate the first and second supply paths with each other and communicate the supply paths for right side and left side running with each other, and a merging position to interrupt the first and second supply paths and interrupt the supply paths for right side and left side running.
