Sheet metal parts processing technology knowledge

　　What are sheet metal parts? Sheet metal parts are parts made by a comprehensive cold processing process for metal sheets (usually less than 6mm), including shearing, punching/cutting/compositing, folding, welding, riveting, splicing, and forming. .

　　Features

　　1. Uniform thickness. For a part, the thickness of all parts is the same.

　　2. Light weight, high strength, conductive, low cost, and good mass production performance.

　　Processing technology

　　NO.1 Cut

　　The equipment used in the shearing process is a shearing machine, which can cut a sheet of metal into basic shapes.

　　Advantages: low processing cost;

　　Disadvantages: The accuracy is average, the cutting has burrs, and the cutting shapes are all simple rectangles or other simple graphics composed of straight lines.

　　Before the shearing process, the expanded size of the part must be calculated. The expanded size is related to the bending radius, bending angle, plate material, and plate thickness.

　　NO.2 The equipment for the punching process is a punch machine, which can further process the cut materials into shape. Stamping various shapes requires different molds. Common molds include round holes, oblong holes, and bosses; the accuracy is high. Boss: The material is not removed. Note that the height of the boss is limited, which is related to the plate material, plate thickness, boss slope angle, etc. There are many types of bosses, including heat dissipation holes, mounting holes, etc. Due to the influence of bending, the distance between the edge of the design hole and the edge of the plate and the bending edge will be limited.

　　NO.3 Laser cutting processing equipment: laser cutting machine. For material removal that cannot be completed by shearing or punching processes, or for plates with high hardness that can easily damage the mold, such as rounded corners, or when there is no ready-made mold to punch the required shape, laser cutting can be used to complete the material before bending. of forming. Advantages: burr-free cutting, high precision, and can cut any graphics, such as leaves, flowers, etc. Disadvantages: high process cost.

　　NO.4 Bending processing equipment: bending machine, plate rolling machine. They can fold or roll metal sheets into the required shape, which is the forming process of parts; the upper and lower knives of the bending machine are used to cold-press the metal sheet to deform it, and the process of obtaining the required shape is called bending .

　　Bending is the last step in sheet metal forming. Whether the parts can be unfolded and bent into shape requires attention to the following points: 1. Lack of material, as shown below, the boss is too high and exceeds the ductility of the material. Bosses are generally used In order to increase the installation size or avoid installation conflicts, the boss must be made without changing the internal structure of the material or affecting the structural strength. For example: the angle between the conical surface of the boss and the datum plane is 45°, and the height is 3 times the thickness of the plate.

　　2. Redundant materials: Redundant materials are often found where multiple bending edges are closed, mostly due to process errors or drawing errors.

　　3. Bending restrictions: Most bending machines have certain restrictions on bending.

　　Unilateral height: The size of the bending machine and the height of the upper knife. The solution can be multi-sided large-angle bending. Height of both sides: no greater than the maximum height of one side. In addition to all restrictions on the height of one side, it is also limited by the bottom edge: bending height < bottom edge. 4. Since sheet metal parts are formed by bending a thin metal plate, the contact between the bent edges is not sealed and there is no hard connection. If not processed, the strength will be affected. The usual processing method is welding. The technical requirements on the drawing are: welding angle , welding angle, rounding.

　　NO.5 Surface treatment

　　Since the sheet metal parts are thin, they are not suitable for hot-dip galvanizing. Common surface treatment methods include: phosphating and electrostatic spraying. The color depends on the project. This process is suitable for black parts with untreated surface materials.