The preferred brand for sheet metal processing --- Bolima CNC Cutting Machine
Sheet metal, as of now, does not have a comprehensive definition. According to a definition from a foreign professional journal, it can be defined as: Sheet metal is a comprehensive cold working process targeting thin metal plates (usually below 6mm), including cutting, punching/cutting/compound operations, bending, welding, riveting, splicing, forming (such as automobile body), etc. Its most significant feature is that the thickness of the same part remains consistent.
Sheet metal cutting and processing is an important procedure in the formation of sheet metal products. It includes traditional methods such as cutting materials, blanking, press forming, etc., along with their respective process parameters. It also encompasses various cold stamping die structures and process parameters, operating principles and methods of different equipment, and new stamping technologies and processes.
For any sheet metal part, there is a certain processing procedure, known as the process flow. With the structural differences in sheet metal parts, the process flows may vary but generally do not exceed the following points:
1. Design and draw the part diagram of the sheet metal component, also called three-view diagrams. Its function is to express the structure of the sheet metal component through drawings.
2. Draw the development diagram. This means unfolding a structurally complex part into a flat plate.
3. Material cutting. There are many ways to cut material, mainly including:
a. Shearing. Using a shear to cut out the length and width dimensions of the unfolded diagram. If there are holes or angles to be cut, they can then be transferred to the punch press combined with molds to form the holes and angles.
b. Punch press cutting. Utilizing a punch press to form the flat structure of the part after unfolding in one or multiple steps on the sheet. Its advantage is short labor time, high efficiency, reduced processing costs, and is often used in batch production.
c. NC numerical control cutting. When using NC cutting, you first need to write a CNC machining program. That is, using programming software, convert the drawn development diagram into a program recognizable by CNC machining equipment. Let the machine follow these programs step by step to punch out the structural shape of the flat piece on a steel plate.
d. Laser cutting. Using laser cutting technology to cut out the structural shape of the flat piece on a steel plate.
4. Flanging and tapping. Flanging is also called stretching a hole, which involves stretching a smaller base hole into a slightly larger hole, followed by tapping threads into the stretched hole. This increases strength and prevents stripped threads. It is commonly used for relatively thin sheet metal processing. When the sheet thickness is larger, such as 2.0mm, 2.5mm and above, we can directly tap without flanging.
5. Punch press processing. Common punch press operations include punching holes, cutting corners, punching dropouts, forming convex bumps, tearing, stretching holes, etc., to achieve the desired processing results. These operations require corresponding molds. For example, convex bump molding uses a convex bump mold, while tearing requires a tear-forming mold.
6. Press riveting. In our factory, we frequently use press rivets such as rivet studs, rivet nuts, and rivet screws. The press riveting method is generally completed through a punch press or hydraulic press riveting machine, attaching them to the sheet metal component.
7. Bending. Bending involves folding a 2D flat piece into a 3D part. This operation requires a brake press and appropriate bending dies. There is also a specific bending sequence; the principle is to bend first what will not interfere with the next step, and leave what will cause interference until last.
8. Welding. Welding involves joining multiple parts together or edge seam welding of a single part to increase its strength. Common welding methods include CO2 gas shielded welding, TIG welding, spot welding, robotic welding, etc. The selection of these welding methods depends on actual requirements and material types. Generally, CO2 gas shielded welding is used for steel plate welding, while TIG welding is used for aluminum plate welding.
[Link to reference website: http://www.gz-sds.com/]