Oil return valve limit structure of press hydraulic pump

The utility model provides an oil return valve limit structure of press hydraulic pump, includes pneumatic cylinder, base, air pump and the pump body, establishes oil return valve and oil outlet on the base, characteristics: add stop device on the base and near one side of oil return valve, stop device includes the stopper, the one end of stopper is on the base, the other end constructs for the free end, establish the opening in the middle of the tip of free end, the screw rod of oil return valve is visited in the base, serve near one of handle at the screw rod and still offer the spacing groove, the opening card is established at limiting groove, along with the screw in of screw rod or screw out and make the free end of stopper slide around the stroke within range of spacing groove, make screw rod displacement backward when the twist grip, support until the free end of stopper and lean on on the lateral wall of spacing groove one side and make the screw rod slide outside can't be again to the base. Realize q