Detailed Operation Process of Sheet Metal Machining

First, the processing of metal sheet is called sheet metal machining.

Specifically, it includes the production of chimneys, barrels, oil tanks and pots, ventilation pipes, elbows of different sizes, round and square shapes, funnels and more. The main processes involve shearing, bending, folding, shaping, welding, riveting, and require a certain level of geometric knowledge.

Second, there is a general processing flow for sheet metal machining.

For any piece of sheet metal, it has its own processing flow, also known as the process flow. As the structures of sheet metal differ, the process flow may vary, but it basically includes the following:

1. Design and draw the Assembly Drawing of the sheet metal, also known as the three-view drawing. Its function is to express the structure of the sheet metal in a drawing format.

2. Make the flattened drawing. That is to flatten a complex structured part into a flat plate.

3. Prepare materials.

There are many ways of preparing materials, mainly through the following methods:

①Cutting bed material. It is to use the cutting bed to cut out the size of the flattened drawing. If punching and cutting angles are required, punching and cutting angles will be done by the punching machine combining molds.

②Punching material. It is to punch the flattened flat-plate structure of a part through one step or multiple steps on the sheet metal. Its advantage is that it saves time, reduces production costs, and is often used in batch production.

③NC numerical control material cutting. When cutting material numerically, a numerical control processing program must be written first. That is to use programming software to write the flattened drawing into a program that the NC numerical control machine tool can recognize. According to these programs, the structural shape of the flat plate is punched out step by step on a piece of iron plate.

④Laser cutting. It is to use the laser cutting method to cut the structural shape of the flat plate of a part on a piece of iron plate.

4. Flanging tapping

Flanging, also known as punching, is to punch a slightly larger hole on a small base hole, and then tap on the punched hole. This can increase its strength and prevent slip teeth. It is generally used for sheet metal machining with thinner plate thickness. When the plate thickness is large, such as 2.0, 2.5 and above, one can directly tap without flanging.

5. Punch processing

The punch processing methods generally used include punching, cutting angles, punching fall-offs, punching bumps, punching tearing, punching holes, and other ways to achieve the processing objective. The processing requires corresponding molds to complete the operation. There are bump molds for punching bumps, and tearing forming molds for punching tearing.

6. Riveting

Riveting, in our factory, is often used for riveting bolts, nuts, or screws. Its riveting method is generally completed through a punching machine or a hydraulic riveting machine, to rivet to the sheet metal.

7. Bending

Bending is to fold the 2D flat plate into a 3D part. Its processing requires a bending machine and the corresponding bending mold to complete the operation. There is also a certain bending order, and the principle is to fold those that do not interfere with the next cut first, and fold those that interfere later.

8. Welding

Welding is to weld multiple parts together to achieve the processing objective, or to weld the edge seam of a single part to increase its strength. Its processing methods generally include CO2 gas shielded welding, argon arc welding, spot welding, robot welding, etc. The choice of these welding methods is determined based on 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 parts are larger and the welding seams are longer, such as in the welding of machine cabinets. It can save a lot of task time, improve work efficiency and welding quality.

9. Surface treatment

The surface treatment generally includes phosphate film, electroplated five-color zinc, chromate, baked enamel, oxidation, etc. The phosphate film is generally used for cold rolled plates and electrolytic plates, its function is mainly to coat the surface of the part with a protective film to prevent oxidation; and to enhance the adhesion of the baked enamel. Electroplated five-color zinc is generally used for surface treatment of cold rolled plates; chromate and oxidation are generally used for surface treatment of aluminum plates and aluminum profiles. The choice of specific surface treatment methods is determined based on customer requirements.

10. Assembly

Assembly refers to combining multiple parts or components in a certain way to form a complete product. Attention should be paid to protect the parts and avoid scratches. Assembly is the last step in the completion of a product. If the parts are damaged due to scratches, rework is required, which will waste a lot of processing time and increase the cost of the product. Therefore, special attention should be paid to the protection of the parts.