1. Shrinkage molding. In order to restore the deformed part to its original shape, it is necessary to find a way to shrink and extend the part.

2. The development of wrinkles. Irregular folds may appear in the stamping process of metal plate due to the collision of car body. When repairing, if it is convenient and feasible, the folds can be untied by car stretching and then flattened. If it is inconvenient or infeasible, take down the car body and repair it under the car. Key points of pleating: First, try to pry open the dead pleat from the inside to remove the live pleat, then heat it, hit the most convex ridge of the live pleat with a hammer, gradually expand it and restore it to its original state.

3. Pull and reset. The bolt tensioner pushes the plunger rod away by the pressure generated by the hydraulic cylinder, thus stretching the deformed plate. In addition, there is a spiral stretching machine with movable hooks at both ends of the screw. When in use, the drawn iron pipe can rotate, so that the screws at both ends can be shortened at the same time, one end of the hook is fixed, and the other end of the hook pulls out the plate.

4, reset the slide rail, according to the deformation position and degree of the vehicle, sliding reset is to use the effective empty room, with the support of adjacent parts, using the lever principle to carry out plastic repair.