The application of load-carrying body of automobile sheet metal parts has been gradually popularized

2020-09-08 10:17:49

It is also one of the commonly used methods of concave shaping to pull out the concave by using a pulling device. The pulling device includes a suction cup, a pulling cylinder and a special puller. There is a suction cup at the end of the pneumatic concave puller to produce vacuum, and the force exerted by the inertia hammer will pull the metal depression 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. Holding the handle direction with one hand, the depression can be eliminated by pulling repeatedly, and then the through-hole is blocked with packing. In order to avoid the inconvenience caused by drilling, the pin can also be used to replace the screw in the concave spot welding, and then the tool is used to cut the solder joint after pulling out, so as to maintain the integrity of the metal surface.

In the process of temperature rising, the steel plate expands to the surrounding area with the hot spot as the center and produces compressive stress on the periphery. When the temperature continues to rise, the steel plate will burn red locally and become soft, which relieves the pressure in the central area and makes the surrounding steel plate recover deformation. The red burning area is compressed and thickened, and the surrounding steel plate can be freely deformed and extended to restore its shape. For the local heating point, spray water or apply wet cloth to cool the heating part suddenly, and the steel plate shrinks immediately. The tensile load on the periphery is generated at the central part. The strong force will stretch the periphery to the center and offset the compression load generated in the deformation process to restore the original shape.

Pleating is a method to deal with tensile deformation. It does not make the metal shrink when heated. Instead, it uses hammer and anvil to make some folds in the tensile deformation part. During operation, make the hammer and anvil dislocation, and gently knock with the beak hammer to make the parts wrinkle. The pleats will be slightly lower than the rest. After the filling is completed, this part shall be ground flush with other parts with a file or gravel paper.

The structure and material of automobile body change greatly, and the application of load-bearing body is gradually popularized. Therefore, the requirements of body repair technology are higher and higher. Sheet metal repair technology not only requires the recovery of the shape of the car body, but also ensures that the performance of the repaired body is close to the state before the damage, so as to avoid the occurrence of secondary accidents.

There are five kinds of repair methods for automobile sheet metal parts: knock out repair method, prying repair method, stretching repair method, heating shrinkage method and pleating method.

For the local bulge and depression in a small area, the single and small shallow convex mark and dent can be repaired by knocking out method, so that the metal can be extended and deformed to restore its original shape.

Pry the concave part with a flat knife (or spoon shaped board) and pointed tools (such as various prying picks) to gradually restore the original shape of the depression.