What are the main methods of repairing automobile sheet metal parts?

2020-05-10 11:52:13

The repair methods of automobile sheet metal parts mainly include the following five parts: knock off repair method, pry top repair method, stretching repair method, heating shrinkage method, pleating method, etc.

1. Knock out the repair method.

For a small range of local bulges and depressions, the knock-out method can be used to repair single and shallow bulges and dents, so as to make the metal produce extension deformation and return to its original shape.

2. Prying repair method.

Use a flat knife (or spoon shaped plate) and a sharp tool (such as a variety of pickaxes) to pry the sunken part of the top, so that the sunken part gradually returns to the original shape.

3. Stretch repair.

It is also one of the commonly used methods of concave shaping to pull out the concave with the pull out device, which includes a suction cup, a pull cylinder and a special puller. A suction cup is arranged at the end of the pneumatic concave puller to generate vacuum, and the force exerted by the inertia hammer pulls the metal concave part back to the original shape. The screw at one end of the pull rod puller is screwed into the hole drilled in advance at the concave part, and the concave part can be eliminated by repeatedly pulling the handle with one hand, and then the through hole is blocked with filler. In order to avoid the inconvenience caused by drilling, pins can also be used to replace screw in screws in the spot welding of the concave part, and then the welding spots can be cut off with a knife after being pulled out, so as to maintain the integrity of the metal surface.

4. Heating shrinkage method.

In the process of temperature rising, the hot spot is added as the center of the steel plate to expand to the surrounding, which produces the compressive stress on the surrounding. When the temperature continues to rise, the steel plate is partially burnt red and softened, which relieves the pressure in the central area and restores the deformation of the surrounding steel plate. The red area is compressed and thickened, and the surrounding steel plate can be freely deformed and extended to restore its shape. For local heating points, water spray or wet cloth can be applied suddenly to make the heating part cool suddenly, and the steel plate shrinks immediately. The central part generates tensile load on the periphery, which strongly stretches the periphery to the center, offsets the compression load generated in the deformation process, so as to restore the original shape.

5. Pleating.

Pleating is a method to deal with the stretch deformation. It does not make the metal shrink by heating, but makes some pleats in the stretch deformation part with hammer and anvil iron. During operation, the hammer and anvil shall be misplaced, and the part shall be pleated by gently tapping with crane mouth hammer. The pleats will be slightly lower than the rest. After filling, use a file or gravel paper to polish this part flush with other parts.