What are the technological processes of sheet metal bending?（one）

I. When the drawings are ready, differentblanking modes are selected according to the development drawings and batchsizes, including laser, CNC punch, cutting board, die and so on. Thencorresponding blanking modes are made according to the drawings. NC punch isinfluenced by cutting tools. For some special-shaped workpieces and irregularholes, there will be larger burrs on the edge. It is necessary to deburr later,and it also has some influence on the accuracy of workpiece. Laser processinghas no tool limitation, flat section, and is suitable for special-shapedworkpiece processing, but for small-scale processing. Workpiece processingtakes a long time. Placing the worktable beside the numerical control and laseris beneficial for the plate to be placed on the machine for processing, andreduces the workload of lifting the plate. Some available edges are placed indesignated places to provide materials for bending test moulds.

After blanking, the edges, burrs andcontacts should be repaired (polished). At the tool contacts, they should berepaired with a flat file. For the parts with larger burrs, they should berepaired with a grinder. For the small inner hole contacts, they should berepaired with a corresponding small file to ensure the beauty of theappearance. At the same time, the shape should be repaired as well. The positioningduring bending ensures that the position of the workpiece on the bendingmachine is the same and the size of the same batch of products is the same.

II. After the blanking is completed, itenters the next process, and different workpieces enter the correspondingprocess according to the processing requirements. There are bending, riveting,flanging tapping, spot welding, convex hull, segment difference. Sometimes,after bending one or two rounds, the nut or stud should be pressed well. Wherethere are die convex hull and segment difference, processing should beconsidered first, so as to avoid interference in other processes beforeprocessing, and the required processing can not be completed. When there is aclasp on the upper or lower shell, if the clasp cannot be welded after bending,it should be processed before bending.

When bending, it is necessary to determinethe tool and groove used in bending according to the size of the drawing andthe thickness of the material. To avoid the deformation caused by the collisionbetween the product and the tool is the key to the selection of the upper die(different types of upper die may be used in the same product). The selectionof the lower die depends on the thickness of the plate. The second is todetermine the order of bending. The general rule of bending is to start frominside to outside, small to big, special to common. The workpiece with pressingedge first bends the workpiece to 30 40 and then press the workpiece to deathwith the leveling die.

When pressing riveting, we should considerthe height of the stud and choose the same and different dies, and then adjustthe pressure of the press to ensure that the surface of the stud and theworkpiece is even, so as to avoid the scrap of the workpiece caused by the studnot being pressed firmly or pressing out more than the workpiece surface.

There are argon arc welding, spot welding,carbon dioxide protection welding, manual arc welding, etc. Spot welding shouldfirst consider the position of workpiece welding, and in mass production,consider positioning tooling to ensure accurate spot welding position.

In order to solder firmly, the bump on theworkpiece to be welded can make the bump contact with the flat plate uniformlybefore electrified welding, so as to ensure the consistency of heating at allpoints, and can also determine the welding position. Similarly, to carry outwelding, it is necessary to adjust the pre-pressing time, the holding time, theholding time, the resting time to ensure that the workpiece is available. Firmby spot welding.

After spot welding, there will be weldscars on the surface of the workpiece, which need to be treated by a flatgrinder. Subarc welding is mainly used when two workpieces are larger, and whenthey are joined together, or when the edges and corners of one workpiece areprocessed, so that the surface of the workpiece can be smooth and smooth. Theheat generated during argon arc welding can easily deform the workpiece. Afterwelding, the workpiece should be treated by a grinder and a flat grinder,especially in the aspect of edges and corners.