Research on the development of sheet metal processing and process analysis and improvement

Sheet metal processing has processing flexibility and is suitable for small-batch production. Therefore, it has been widely used in many industries such as chassis cabinets, home appliances, hardware products, etc. This article mainly analyzes how to reasonably arrange the processing technology in small-batch production, as well as the process problems that may arise in the sheet metal processing process, and proposes improvement plans.

With the acceleration of the replacement of home appliances and instruments, many products tend to be miniaturized and lightweight, and the advantages of sheet metal processing are becoming more and more obvious. How to quickly meet the needs of various products has become an urgent problem to be solved in the sheet metal processing process. The sheet metal processing technology has also been continuously improved with the development of society, from the initial manual sheet metal to stamping sheet metal, to the current CNC sheet metal, making sheet metal processing more precise and intelligent.

Sheet metal processing development trend assumptions

A few years ago, sheet metal processing equipment mainly included ordinary punching machines, laser machines and bending machines. The disadvantages of these equipment are low processing positioning accuracy, and the accuracy of dimensions usually depends on experienced operators to ensure, which is very difficult for the processing of small and precise products.

With the development of automation, CNC bending machines and laser punching compound machines have been widely used in the sheet metal processing industry in recent years, and the advancement of programming software has further improved the processing quality and efficiency. Now, operators only need to call pre-edited programs to complete the processing, which greatly reduces the skill requirements for operators and also guarantees the processing quality of high-precision products.

Although CNC sheet metal processing technology has been popularized, the current bending process still mainly relies on manpower. When producing products with larger size and heavier weight, the labor intensity of operators is still very high. Although bending manipulators have begun to be used, their application in the sheet metal processing industry is not yet widespread due to the limitations of product characteristics.

In the future, if a bending follower can be designed to obtain machine tool signals through the API interface of the machine tool to assist operators in producing large-size products, the labor intensity will be greatly reduced. With the further development of automation technology, the use of bending robots to completely replace manual work will also become a development trend in the sheet metal processing industry.

Introduction to sheet metal processing technology

Sheet metal processing mainly includes cutting, bending, welding, riveting, forming and other processes, among which the most commonly used basic processes are cutting, bending and welding. The following is a brief introduction to these three basic processes:

1.Cutting

Sheet metal cutting can be divided into two types: punching and laser processing.

· Punching processing: This is a process that uses a punch combined with a mold for processing. Its advantage is that the dimensional accuracy and relative position accuracy of the holes are high, which is especially suitable for porous products and has high processing efficiency. However, the mold gap needs to be adjusted according to the thickness and properties of the material: if the gap is too large, the product will have more burrs; if the gap is too small, the service life of the mold will be affected and the mold may even be damaged. When punching the product’s outer dimensions, there will be “cutting points” remaining, which will affect the appearance.

· Laser processing: Use a focused high-power beam to irradiate the surface of the material to melt it, and then use auxiliary gas to blow away the molten residue. Its advantages include saving mold costs, fast processing speed, not easy to deform when cutting, small and beautiful cutting gaps. With the introduction of laser punch compound machines, processing efficiency and dimensional accuracy have been significantly improved, making the sheet metal blanking process more accurate and efficient.

2.Bending

2.1 Minimum bending radius

If the radius is too small, the tensile ductility of the material will become stronger. When the ductility reaches the limit, the material will break.

2.2 Bending ductility coefficient

Bending dies of different materials and different V-groove widths will affect it. For example, among aluminum plates, steel plates, and stainless steel plates, when the thickness is the same, the ductility coefficient of stainless steel is the largest, and that of aluminum plates is the smallest.

For the same material, different V-groove widths will also affect the ductility coefficient. Generally, the wider the V-groove, the greater the ductility coefficient. In order to obtain qualified bending dimensions, it is necessary to select a V-groove of appropriate specifications and calculate the ductility coefficient of the material. Since the plate has a bending rebound property, it is usually necessary to select a bending tool with a smaller angle than the required angle.

3.Welding

In the process of sheet metal processing, welding is usually performed to enhance the strength of the joints. Common welding methods include gas shielded welding, laser welding and resistance welding.

· Gas shielded welding: welding wire is required, the welding effect is more beautiful, but the plate is greatly deformed by heat.

· Laser welding: welding wire is also required. Compared with gas shielded welding, the welding effect is better but the cost is higher, and the plate is greatly deformed.

· Resistance welding: welding is performed by contact heating and pressurizing the upper and lower electrode heads, as shown in Figure 2. No welding wire is required, and the plate is less deformed after welding. The welding position of complex shapes will have higher requirements on the shape of the electrode head.

These three processes are the most basic and important parts of sheet metal processing, each with its own characteristics and application scenarios. Through reasonable selection and application, the processing quality and efficiency can be effectively improved.

Difficulties in sheet metal processing

In the process of sheet metal processing, whether it is cutting, bending or welding, it is necessary to design a reasonable and optimal processing sequence according to the characteristics of the product to ensure that the product meets the appearance and quality requirements after processing. With the rapid development of society, the structure of products is gradually developing in the direction of small batches and complexity, and the technical requirements for sheet metal processing technology are also getting higher and higher.

1.Difficulties in cutting process

During the cutting process, special attention should be paid to special processes in the product structure, such as deep drawing process, convex hull process, etc. Since the forming directions and forming sizes of these processes are different, the influence of the machine tool on its structure during movement is also different, and special treatment is required according to the characteristics of the product structure process.

2.Difficulties in bending process

As the structural parts become more complex, the use of non-standard tools in the bending process is increasing. Therefore, in processing programming, it is necessary to break the conventional thinking and design different forms of non-fixed and non-patterned processing procedures.

3.Difficulties in welding process

The welding process also faces similar challenges, especially in the welding process of complex structural parts, the welding parameters must be precisely controlled to ensure the welding quality.

Improvement measures for sheet metal processing

1.Sheet metal processing material selection

When selecting sheet metal processing materials, first of all, it is necessary to ensure that the selected materials meet the material and thickness requirements of the product. For material thickness, accurate measurement and confirmation must be carried out when the material is received to ensure that the thickness is within a reasonable tolerance range. When determining the material size specifications, it is necessary to give priority to the utilization rate of the material and ensure efficient use of the material as much as possible. At the same time, for products of the same material and thickness, the types of sheet specifications should be comprehensively considered and limited, preferably not more than three, to avoid serious waste of materials, thereby indirectly increasing processing costs.

Secondly, according to the shape and size of the actual processed product, select materials that match it to ensure the consistency and uniformity of the overall product. Finally, in order to further improve material utilization and save processing costs, it is possible to consider using the waste part of the internal structure of large-size parts as processing materials for small-size parts, thereby achieving effective utilization and conservation of materials.

2.Hole structure design

In sheet metal processing, hole structure design is crucial. When designing, it is necessary to take into account the product appearance and quality requirements to ensure easy processing. First, the position, size, shape and number of holes are accurately designed according to the product structure and purpose, and planning is made for the processing process. In order to ensure the strength and quality of the product, the hole margin should be kept at more than twice the material thickness. Secondly, optimize the processing technology according to specific problems, such as controlling the distance between the hole and the bending position to avoid deformation of the hole due to material extension.

3.Welding structure design

Welding structure design covers many aspects. First, in the design stage of sheet metal structural parts, reserved space must be considered to avoid welding quality problems caused by insufficient space. Secondly, the design of welding time and welding seams should be appropriate to prevent deformation of sheet metal sheets. The welding point design should be symmetrical and avoid excessive distance from the weld, which not only ensures aesthetics but also ensures that the sheet metal parts meet the load-bearing standards.

Conclusion

Sheet metal processing has become an indispensable part of our lives. Driven by the diversified market, we need to deeply study the principles and processes of sheet metal processing, gradually optimize the processing technology, and design and manufacture high-quality sheet metal products in the shortest time. This can promote the sheet metal manufacturing industry to move forward in a better direction of development.