Die clamping force pre-tightening structure of die clamping mechanism

The utility model discloses a clamping force pre-tightening structure of a clamping mechanism. The clamping force pre-tightening structure comprises a bottom plate, vertical plates are fixedly connected to the two sides of the top of the bottom plate, sliding grooves are formed in the opposite sides of the vertical plates, sliding rods are fixedly connected to inner cavities of the sliding grooves, sliding blocks are connected to the surfaces of the sliding rods in a sliding mode, and springs are arranged at the bottoms of the surfaces of the sliding rods in a sleeved mode. Through cooperation of the bottom plate, the vertical plate, the sliding groove, the sliding rod, the sliding block, the spring, the lifting plate, the upper die, a pressing block, a limiting rod, a feeding pipe, a lower die, a pressure sensor, a limiting hole, a buffering strip, a through groove, a connecting rod, a motor, a winding wheel, a pulling rope, a draught fan, an exhaust pipe, an air uniformizing plate and a PLC, the die clampin