Positioning device for belt bed supporting frame

The invention discloses a positioning device for a belt bed support frame. The positioning device for the belt bed support frame comprises a U-shaped frame, a mounting plate is fixed in the U-shaped frame, two fixed blocks I and two fixed blocks II are symmetrically fixed on the mounting plate, the two fixed blocks I are fixed through a connecting rod, the fixed blocks I are in threaded connection with first screw rods, the two ends of the first screw rods extend out of the first fixing blocks and are fixed to first positioning plates and rotating blocks correspondingly, the second fixing blocks are in threaded connection with second screw rods, the two ends of the second screw rods extend out of the second fixing blocks and are fixed to second positioning plates correspondingly, air cylinders are fixed to the two ends of the U-shaped frame correspondingly, and piston rods of the air cylinders are fixed to positioning rods. The second fixing blocks are located between the first fixing blocks and the positioni