Sheet metal process flow
Generally, the sheet metal repair of automobile body surface operation has to go through several processes. Firstly, the vehicle to be repaired is inspected to determine its body structure type, and then the maintenance method is determined according to the damaged parts. Finally, arrange a reasonable repair process for different parts as needed.
Firstly, the repair process is determined according to the body structure.
1, the body is fixed. For the pull-out index correction of the car body, the car body must be fixed, otherwise,
Under the action of tensile force, the whole displacement will occur, and the purpose of index correction cannot be achieved.
2. Physical correction procedures
Understand the performance of equipment and measures for safe use.
Analyze and judge the damage of the body and determine the traction scheme.
Fixed point of preliminary correction foundation
Correct the anchor point, check the correction effect, and pull the correction as planned.
3. Before traction correction, protect the inside and outside of the car body as follows, and try to take out the internal components, such as seats, instrument panels, car cushions, etc.
When welding, cover the glass, seat, instrument panel and other parts with heat insulation materials to prevent burns.
Remove the external parts of the car body and protect the car body with cotton cloth or protective tape to prevent scratches.
If there are scratches on the paint surface, they must be repaired to prevent corrosion.
4. Repair of the front end damage of the car body
The damage of the front end of the car body is mainly caused by the collision of the front end (such as rear-end collision). The damaged parts include the fender on one side of the front cross member, the side member and the front fender on the other side.
The renovation of the front end should start with the side member of the front fender. First, the supporting structure needs to be repaired. Select the side to be replaced and pull the side beam first.
5. Repair the damage at the rear of the car body
During calibration, connect the fixture or hook to the rear of the rear longitudinal beam, the rear floor or the rear roof, and the rear end of the side panel, and measure the dimensions of each part under the car body while pulling, and observe the fit clearance of the car body panels to determine the necessary repair degree.
When the rear side member is seriously impacted, which affects the deformation switch of the rear door frame, the stress of the rear roof side plate can be relieved by pulling the side member.
Second, determine the repair process according to the damage degree of the car body surface.
1, concave-convex surface renovation
Plastic surgery of local small lump: stick a pad iron on the back of the lump and hammer the lump.
Position, so that the convex part is compressed to its original shape. When operating, the impact force is required to be light.
Continuous impact at the frequency of 2 times per second, and the hitting points are evenly distributed.
Shaping local depression: unlike the trimming of bump, the hammering point is not on the top surface of pad.
Square, but in the raised part of the iron sheet. Stick the gasket to the lowest point and knock it nearby with a hammer.
Protrusion is enough.
Lever up the dent and trim it with a leveling knife. If there is a dent somewhere on the door surface, a leveling knife will be used.
As a pad, the depression can be repaired by hitting the convex part of the surface.
2. Surface shrinkage molding
Shrinkage of deformed parts on metal plate
Heat the most convex or concave point (stretching center) with torch flame, without cherry red. The amount of heating is related to the degree of stretching.
After heating, tighten the metal structure by tapping quickly around the flushing area and gradually surrounding the center of the heating point. When knocking, use a pad iron on the back of the component, knock with a wooden hammer, and then gently knock with a hammer after cooling.
If a little shrinkage can't achieve the purpose of leveling, you can shrink around the point in the same way, but the heating range is smaller at this time.
After all the contraction points have cooled down, make a comprehensive tap, and the tapping force should be light.