Introduction of sheet metal processing technology
Sheet metal processing is a comprehensive cold processing process for metal sheets (usually below 6mm), including shearing, punching, bending, welding, mold forming and surface treatment. The salient feature is the same thickness of the same part.
Different sheet metal parts have their own processing flow. Some metal sheets are plastically deformed by hand or die stamping to form the desired shape and size, and can be further formed into more complicated parts by welding or a small amount of mechanical processing. But with the differences in the structure of sheet metal parts, the process is also different. Next, let's explain in detail the nine process flows.
Sheet metal processing technology flows:
Process 1: First design and draw a part drawing of its sheet metal parts, which is also called three views. Its purpose is to express the structure of sheet metal parts by means of drawings.
Process 2: Draw the unfolded drawing, that is, develop the parts with more complicated structure into a flat piece.
Process 3: Several commonly used cutting methods
1. Cutting machine cutting method
It mainly uses the shearing machine to cut out the length and width of the unfolded drawing. If there is punching and corner cutting, it is combined with die punching and corner cutting in a rotary punching machine.
2. Punching method
In this way, the flat plate structure after the parts are unfolded on the plate in one or more steps is punched and formed by a punch press. Its advantages are short labor time, high efficiency, and effective reduction of processing costs, which can be seen during mass production.
3. CNC blanking method
When cutting material, use programming software to write NC machining program. Write the developed drawing into a program that can be recognized by the CNC machine tool. According to the procedure, the structural shape of the flat piece is punched out on an iron plate step by step.
It mainly uses laser cutting to cut the structural shape of its flat piece on a wooden board.
Process 4: Flanging and tapping
Flanging is also called tapping. Draw a slightly larger hole in a smaller base hole and tap the hole. This can increase its strength and avoid slipping teeth. It is generally used for the processing of plate parts with a thinner thickness than thin parts, such as plate thicknesses of 2.0 and 2.5. We can tap directly without flanging.
Process 5: Punch processing
Generally speaking, the punching process includes punching and corner cutting, punching and blanking, punching and bulging, punching and tearing, punching and other processing methods. Through these methods, processing purposes can be achieved. The processing requires a considerable mold to complete the operation, such as convex die for punching and bulging, tear forming die for punching and tearing, etc. The way of pressing riveting is generally completed by punching machine or hydraulic pressing riveting machine. In this way, the mold is riveted to the sheet metal part.
Process 6: Bending
Bending refers to folding 2D flat parts into 3D parts. The processing requires a folding bed and corresponding bending mold to complete. It also has a certain bending sequence. The principle is that it does not cause the first fold of interference to the next knife, but will produce the latter fold of interference.
Process 7: Welding
When welding, multiple parts are welded together to achieve the purpose of processing, or the edge of a single part is welded to increase strength. There are generally the following processing methods: CO2 gas shielded welding, argon arc welding, spot welding, robot welding, etc. The selection of these welding methods is based on actual requirements and materials. Generally speaking, CO2 gas shielded welding is used for iron plate welding. Argon arc welding is used for aluminum plate welding. Robot welding is mainly used when the material is relatively large and the weld is long. For cabinet welding, robot welding can be used.
Process 8: Surface treatment
Surface treatment generally includes phosphating film, electroplating colorful zinc, chromate, baking paint, oxidation, etc. Phosphating film is generally used for cold-rolled plates and electrolytic plates. Its function is to plate a protective film on the surface of the material to prevent oxidation, and then it can enhance the adhesion of its baking paint. Electroplated colorful zinc is generally treated with cold-rolled sheets. Chromate and oxidation are generally used for surface treatment of aluminum plates and aluminum profiles. The selection of the specific surface treatment method is based on the requirements of customers.
Process 9: Assembling parts
The so-called assembly is to put multiple parts or components together in a certain way to make it a complete item. It should be noted that the protection of the material is not scratched. Assembly is the final step of an item. If the material cannot be used due to scratches, rework is required. This will waste a lot of processing time and increase the cost of the item. So pay special attention to the protection of the material.