Processing technology of sheet metal chassis

According to the basic processing method of sheet metal parts, such as cutting, bending, stretching, forming and welding. This specification describes the process requirements to be noted for each processing method.

Blanking
According to the different processing methods, the cutting can be divided into general punching, number punching, shearing machine cutting, laser cutting, and wind cutting. Due to the different processing methods, the processing technology of the cutting is also different. Sheet metal blanking methods are mainly digital punching and laser cutting.

Bend
When the material is bent, the outer layer is stretched on the rounded area, and the inner layer is compressed. When the thickness of the material is fixed, the smaller the inner r, the more severe the material’s tensile and compression; when the tensile stress of the outer corner fillet exceeds the material’s ultimate strength, cracks and breaks will occur, therefore, the structure of the bent part Design should avoid too small bending radius.

Stretch
The radius of the fillet between the bottom of the tensile member and the straight wall should be greater than the plate thickness, ie r1≥t. In order to make the drawing progress more smoothly, generally take r1=(3~5)t, the maximum fillet radius should be less than or equal to 8 times the thickness of the plate, that is r1≤8t. Due to the different stresses on the stretched parts, the thickness of the material after stretching will change. Generally speaking, the center of the bottom maintains the original thickness, the material at the bottom fillet becomes thinner, the material at the top near the flange becomes thicker, and the material around the round corner of the rectangular stretch member becomes thicker.

forming
Pressing ribs on the plate-shaped metal parts helps to increase the structural rigidity. The blinds are usually used for ventilation and heat dissipation on various enclosures or cabinets. The molding method is to cut the material by the edge of the punch. The remainder of the punch simultaneously stretch-deforms the material to form a undulating shape with one side open.

welding
Welding methods mainly include arc welding, electroslag welding, gas welding, plasma arc welding, fusion welding, pressure welding and brazing. The welding of sheet metal products is mainly arc welding and gas welding.

Arc welding has the advantages of flexibility, maneuverability, wide applicability, and all-position welding; the equipment used is simple, durable, and low maintenance costs. However, the labor intensity is high and the quality is not stable enough, which depends on the level of the operator. Suitable for welding carbon steel, low alloy steel, stainless steel, stainless steel, copper, aluminum and other non-ferrous alloy gas welding flame temperature and properties can be adjusted, the arc welding heat source is wider than the heat affected zone, the heat is not as concentrated as the arc, the productivity is low, and it is used in thin wall Welding of structures and small parts, weldable steel, cast iron, aluminum, copper and its alloys, cemented carbide, etc.