Hydraulic stroke valve for peanut combined harvester and application method of hydraulic stroke valve

A hydraulic stroke valve for a peanut combined harvester comprises a valve body, a dustproof sealing ring, a piston rod, an O-shaped ring, a blocking plate, a blocking cover, retaining covers and compression spring, wherein the valve body is provided with a cylindrical cavity, two oil storage grooves are formed in the inner cavity, and the upper side and the lower side of the valve body are respectively provided with an oil inlet and an oil outlet connected with the oil storage grooves; an annular groove is formed in the piston rod which is arranged in the inner cavity of the valve body; the dustproof sealing ring and the O-shaped ring are mounted at the end of the inner cavity of the valve body and used for preventing oil leakage and dust entering, and the outer side of the inner cavity of the valve body is fixed by the blocking plate; the compression spring sleeves the two retaining covers and is fixed on one side, close to the oil outlet, of the piston rod; the blocking cover sleeves the compression spring, one end of the blocking cover is abutted against the blocking plate, and the blocking cover and the blocking plate are jointly assembled to the valve body; when the piston rod is mounted in the inner cavity of the valve body, the oil outlet is blocked, and a valve block is not communicated; when external force leftwards acts on the piston rod, the valve block is communicated, and the piston rod ejects automatically and the valve block is closed when the external force is removed. The hydraulic stroke valve is simple in structure, good in manufacturability and low in manufacturing cost.