Clamping device for heavy steel welding, which can prevent gaps

The utility model discloses a gap-preventing clamping device for heavy steel welding. Carrier plate, fixing blocks are installed on the left side and the right side of the upper surface of the carrierplate. A push rod motor is installed at the top of the fixing block, a U-shaped plate is installed on the inner side of a transmission shaft of the push rod motor, a screw block is installed in the top wall of the U-shaped plate, a screw is screwed in the screw block, a pressing plate is installed at the bottom of the screw, and a vacuum suction cup is arranged on the inner side of the bottom wall of the U-shaped plate and fixedly connected with the bottom of the U-shaped plate. According to the utility model, the U-shaped plate and the vacuum chuck are arranged; steel is placed below the pressing plate of the U-shaped plate, the pressing plate of the threaded rod is rotated downwards to conduct primary clamping on the steel, meanwhile, the vacuum pump pumps out air of the vacuum suctioncup through the U-shaped p