Material returning mechanism for hydraulic oil press

The invention discloses a material returning mechanism for a hydraulic oil press. The material returning mechanism includes two fixing plates that are arranged up and down and parallel to each other,wherein two parallel vertical columns are fixedly connected between the two fixing plates; each column is sleeved with a guide sleeve that can be moved up and down; the upper ends of the two guide sleeves are connected with a connecting plate; a screw rod vertically arranged and the central portion of the connecting plate are in thread connection; the screw rod is inserted into a hole in the upperfixing plate; the upper end cap of the screw rod is located above the upper fixing plate; an air cylinder connected with a pneumatic device is fixed between the two guide sleeves; the end head, fitting with the air cylinder, of a piston rod is connected with a connecting frame; the connecting frame is connected with a returning plate through a pin shaft; a punch hole is formed on the returning plate; and the piston rod an