Unloading valve of hydraulic steering gear

The hydraulic steering gear unloading valve comprises a valve body, a movable cavity is formed in the bottom end of the valve body, a main oil inlet communicated with the movable cavity is formed in the top end of the valve body, the inner diameter of the main oil inlet is smaller than that of the movable cavity, a PLS oil inlet is formed in the middle of the side wall of the movable cavity, and an oil outlet is formed in the side wall of the top end of the movable cavity. A valve element assembly is arranged in the movable cavity, and a plug is fixedly connected to the bottom end of the movable cavity. According to the utility model, the valve body, the plug, the guide rod, the sliding sleeve, the piston, the spring and the filter assembly are arranged, when oil enters the PLS oil inlet at one side of the valve body, the oil firstly passes through the filter screen of the filter assembly, the filter screen can filter out fine impurity particles generated by mechanical wear, the impurity particles are prevent