Basic processing of sheet metal parts according to the following material, bending, stretching, molding, welding. This specification describes the process requirements to be noted for each type of processing.
Unloading
Unloading according to the different processing methods, can be divided into universal punching, digital punching, shearing machine opening, laser cutting, wind cutting, due to the different processing methods, the processing of underfeeding processability is also different. Sheet metal undercutting methods are mainly digital punching and laser cutting.
Bending
When the material is bent, on its rounded area, the outer layer receives stretching and the inner layer is compressed. When the material thickness is certain, the smaller the inner r, the more serious the material stretching and compression; when the tensile stress of the outer fillet exceeds the ultimate strength of the material, cracks and breaks will occur, therefore, the structural design of bending parts, should avoid too small bending fillet radius.
Stretching
The radius of the fillet between the bottom of the stretching part and the straight wall should be greater than the plate thickness, i.e. r1 ≥ t . In order to make the stretching proceed more smoothly, generally take r1 = (3~5)t, the maximum radius of the corner should be less than or equal to 8 times the plate thickness, that is, r1 ≤ 8t. Stretching parts due to the stresses at various places vary in size, so that the thickness of the material after the stretching will change. Generally speaking, the bottom of the center to maintain the original thickness, the bottom of the rounded corners of the material becomes thinner, the top of the top near the flange of the material becomes thicker, rectangular tensile parts around the rounded corners of the material becomes thicker.
Molding
The ribbing on the plate metal parts helps to increase the structural rigidity, and the shutters are usually used for ventilation and heat dissipation on various hoods or housings, and the molding method is to cut the material through the edge of one side of the convex mold, while the rest of the convex mold will be the material at the same time for the tensile deformation, to form the undulation of the side of the opening shape.
Welding
Welding methods include arc welding, electroslag welding, gas welding, plasma arc welding, fusion welding, pressure welding, brazing, and sheet metal products are mainly welded by arc welding and gas welding.
Electric arc welding has the advantages of flexibility, mobility, wide applicability, all-position welding; the equipment used is simple, good durability, low maintenance costs. But the labor intensity, quality is not stable enough to determine the level of the operator. Applicable to welding more than 3mm of carbon steel, low alloy steel, stainless steel and copper, aluminum and other non-ferrous alloys gas welding flame temperature and properties can be adjusted in the arc welding heat source than the heat-affected zone is wide, the heat is not as centralized as the arc, low productivity, applied to the welding of thin-walled structures and small pieces of welding, can be welded to steel, cast iron, aluminum, copper and its alloys, cemented carbide and so on.