Processing Technology of Sheet Metal Casing

The sheet metal chassis is a chassis that uses a comprehensive cold working process for metal plates below 6mm and needs to be cooled before use. Its distinctive feature is the uniform thickness of the same part. Next, I will introduce the processing technology of the sheet metal chassis.

1. Blanking

Due to the different processing methods, the blanking processing technology is also different. Sheet metal blanking methods are mainly digital stamping and laser cutting.

2. Bending

When the material is bent, the outer layer is stretched while the inner layer is compressed on the rounded corners. When the thickness of the material is constant, the smaller the inner radius, the more severe the stretching and compression of the material; when the tensile stress of the outer corner exceeds the ultimate strength of the material, cracks and fractures will appear. Therefore, it is necessary to avoid a small bending radius.

3. Stretch

The thickness of the fillet radius test piece and the straight wall between the bottom should be greater than the plate thickness. To make the stretching process more stable, generally, the maximum fillet radius should be less than or equal to 8 times the plate thickness. Due to the different stresses that the tensioned parts bear, the material's thickness after stretching will change.

Generally speaking, the center of the bottom remains the original thickness., the material at the bottom rounded corners becomes thinner, the material at the top near the flange becomes thicker, and the material at the rounded corners around the rectangular stretched piece becomes thicker.

4. Forming

Pressing the ribs on the plate-shaped metal parts helps to improve the structural rigidity. The sheet metal chassis' forming method is to cut the material through the edge of the punch. The remaining punches stretch and deform simultaneously so that one side of the material is opened into a wave shape.

5. Welding

Welding methods mainly include arc welding, electroslag welding, gas welding, plasma arc welding, fusion welding, pressure welding, and brazing, among which the welding of sheet metal chassis is mainly arc welding and gas welding. Arc welding has the advantages of flexibility, mobility, broad applicability, and all-position welding, where the equipment used is simple, durable, and low maintenance cost. However, it is labor-intensive, and the quality is not stable enough, depending on the operator's level. Arc welding is suitable for welding carbon steel, low alloy steel, stainless steel and copper, aluminum, and other non-ferrous alloys over 3mm, during when the temperature and performance of the gas welding flame can be adjusted.