General Processing Flow of Sheet Metal

For any sheet metal part, there is a certain processing process, also known as the process flow. Depending on the structure of the sheet metal part, the process flow may vary, but overall it does not exceed the following points

1. Design and draw the part diagram of its sheet metal parts, also known as the three views. Its function is to express the structure of its sheet metal parts in the form of drawings

2. Draw an unfolding diagram, which means unfolding a complex structural part into a flat piece

3. Cutting. There are many ways to cut, mainly the following:

a. Cutting with a shearing machine is the process of using a shearing machine to cut out the dimensions of the unfolded shape. If there are punched holes or corners, they can be combined with a mold to form the shape

b. Punching machine cutting is the use of a punching machine to unfold parts in one or more steps on a sheet metal to form a flat structure. Its advantages are short labor consumption, high efficiency, and can reduce processing costs. It is often used in mass production

c. NC CNC cutting When NC cutting, the first step is to write a CNC machining program. This is to use programming software to write the unfolded diagram into a program that can be recognized by the NC machining machine tool. Based on these programs, the structure and shape of the flat piece are punched step by step on an iron plate

d. Laser cutting is the use of laser cutting to cut the structural shape of a flat piece on an iron plate

4. Flanging tapping. Flanging, also known as tapping, is a process of drawing a slightly larger hole on a smaller base hole and then tapping it on the tapping hole. This can increase its strength and avoid slipping. It is generally used for sheet metal processing with thinner plate thickness. When the plate thickness is larger, such as 2.0, 2.5, and above, we can directly tap it without flipping

5. Punching machine processing. Generally, punching and corner cutting, punching and material dropping, punching convex hull, punching and tearing, hole drawing and other processing methods are used to achieve the processing purpose. The processing requires corresponding molds to complete the operation. There are convex hull molds for punching convex hull, and tearing forming molds for punching and tearing

6. Riveting. For our factory, commonly used riveting methods include riveting bolts, riveting nuts, riveting screws, etc. The riveting process is usually completed by using a punch or hydraulic riveting machine to rivet them onto sheet metal parts

7. Bending. Bending is the process of folding a 2D flat part into a 3D part. Its processing requires a bending machine and corresponding bending molds to complete the operation. It also has a certain bending sequence, which is based on the principle of first folding without interference with the next cutting tool and then folding after interference

8. Welding. Welding is the process of welding multiple parts together to achieve the purpose of processing or welding the edges of individual parts to increase their strength. There are generally several processing methods: CO2 gas shielded welding, argon arc welding, spot welding, robot welding, etc. The selection of these welding methods is determined by actual requirements and materials. Generally speaking, CO2 gas shielded welding is used for welding iron plates; Argon arc welding is used for welding aluminum plates; Robot welding is mainly used when the material is large and the weld seam is long. For example, in cabinet welding, robot welding can be used to save a lot of task time, improve work efficiency and welding quality

9. Surface treatment. Surface treatment generally includes phosphating film, electroplating of colorful zinc, chromate, baking paint, oxidation, etc. Phosphating film is generally used for cold-rolled and electrolytic plates, and its main function is to coat a protective film on the material surface to prevent oxidation; Furthermore, it can enhance the adhesion of its paint. Electroplating colorful zinc is generally treated with cold-rolled sheet surfaces; Chromate and oxidation are generally used for surface treatment of aluminum plates and aluminum profiles; The selection of specific surface treatment methods is determined according to the customer's requirements

10. Assembly. The so-called assembly is to assemble multiple parts or components together in a certain way, making them a complete product. One thing to pay attention to is the protection of the parts, which should not be scratched or damaged. Assembly is the final step of completing a material. If the parts cannot be used due to scratches or scratches, they need to be reworked, which will waste a lot of processing time and increase the cost of the materials. Therefore, special attention should be paid to the protection of the parts