What is cold stamping and die design ?

Cold stamping is a pressure method that uses a die installed on a press to apply pressure to the material to cause it to separate or plastically deform, thereby obtaining the required parts (commonly known as stamping or punching). Because it is usually processed at the room temperature of the press, it is called cold stamping.
The main feature of the cold stamping production process is to rely on the die and stamping equipment to complete the processing, which is convenient for automation, high productivity, and easy operation. For ordinary presses, each machine can produce several to dozens of stamping parts per minute, while high-speed punching machines can produce hundreds or even thousands of stamping parts per minute. The parts obtained by cold stamping generally do not need to be cut, so it is an indispensable cutting method that saves energy and saves raw materials. Since the raw materials used for cold stamping are mostly sheet or strip materials with good surface quality, the dimensional tolerances of the punched parts are guaranteed by the die, so the dimensions are stable and the interchangeability is good. Cold stamping products have thin walls, light weight, and good rigidity. They can be processed into parts with complex shapes, ranging from the second hand of a watch to the longitudinal beam of a car, and covering parts.
However, since die manufacturing is generally produced in small batches of single pieces, with high precision and high technical requirements, it is a technology-intensive product with high manufacturing costs. Therefore, cold stamping production can only obtain a higher economic effect in large quantities.
In summary, compared with other processing methods, cold stamping has unique characteristics, so it is widely used in industrial production, especially in mass production. Quite a lot of industrial sectors are increasingly using cold stamping to process product parts, such as machinery manufacturing, vehicle production, aerospace, electronics, electrical appliances, light industry, instrumentation and daily necessities. In these industrial sectors, the proportion of stamping parts is quite large. Many parts that were made by casting, forging and cutting methods in the past have been replaced by stamping parts with light weight and good rigidity. Through stamping, productivity is greatly improved and costs are reduced. It can be said that if the stamping process is not widely used in production, it is difficult for many industrial sectors to increase productivity, improve quality, and reduce costs. It is difficult to update products.
With the advancement of science and technology and the development of society, the requirements of products for molds are getting higher and higher. The traditional mold design and manufacturing methods have been unable to meet the needs of product and era update. Especially since the 1990s, the variety and quantity of industrial products have been increasing, and new requirements have been placed on product quality, style and appearance, which has increased the demand for molds, and the quality requirements for molds have become higher and higher. Industry development, product replacement and product competitiveness. Therefore, rapidly improving the technical level of the mold has become an urgent task.
With the development of modern industry, cold stamping technology has developed rapidly.
1. Cold stamping process
Research and promotion of the important trends in the development of various stamping technologies aimed at improving productivity and product quality, reducing costs and expanding the application range of stamping processes. At present, advanced stamping processes that have emerged at home and abroad and are rapidly used for production include precision stamping, flexible film forming, superplastic forming, dieless multi-point forming, high energy forming such as explosion and electromagnetic, high-efficiency precision stamping technology, and cold extrusion technology . These advanced stamping technologies have achieved good technical and economic effects in actual production.
Precision stamping is not only an effective method to improve the accuracy of stamping parts, but also an important way to expand the scope of stamping processing. At present, the precision of precision punching can reach IT6 ~ IT7, and the thickness of the sheet can reach 25mm. The fine blanking method can not only be blanked, but also formed (precision bending, deep drawing, flanging, cold extrusion, embossing and countersinking, etc.).
2. Design and manufacturing of die
Die is the basic condition to realize the production of die. At present, there are two trends in die design and manufacturing that should be given sufficient attention.
(1) The mold structure and accuracy are developing in two aspects
On the one hand, in order to meet the needs of high-speed, automatic, precision, safety and other large-scale automated production, the die is developing in the direction of high efficiency, precision, long life, multi-station, and multi-function; on the other hand, to adapt to the replacement of products on the market Rapid requirements, the design and manufacturing of various rapid prototyping methods and simple economical dies have developed rapidly.
The design and manufacturing level of high-efficiency, precision, multi-function, long-life multi-station progressive die and automobile cover die represents the modern die technology level. China can design and manufacture electromechanical integration, which reaches the international advanced level of high efficiency, precision, long life, multi-station progressive die, the accuracy of working parts reaches 2 ~ 5µm, the step accuracy reaches 2 ~ 3µm, and the total life span reaches 100 million. More than mold times; China’s automobile industry already has the production capacity of complete cover stamping dies for mid-range cars, and applies high-strength resin casting forming cover stamping dies in automobile trial production and small batch production to shorten the trial production cycle, reduce costs, and accelerate the speed of new models Development.
(2) Modernization of mold design and manufacturing
Computer technology, information technology and other advanced technologies are widely used in mold technology, which is a profound and revolutionary change in the design and manufacturing level of mold technology. At present, the most prominent is the mold CAD / CAM / CAE. Today’s world mold industry pattern is based on the industrialized countries of Japan, the United States and Europe as the world’s leading mold technology development, occupying half of the world mold, they have modern design methods and advanced mold manufacturing equipment, especially in recent years The country regards the CAD / CAM system as the arm of the development of the mold industry, and the development momentum is in full swing.
Due to the rapid development of mold technology, mold CAD / CAM has developed rapidly and is widely used because of its advanced technology. Its technical and economic effects are unmatched by traditional mold design and manufacturing methods, and have the following characteristics:
1 Shorten the production cycle of the mold.
2. High mold quality.
3. Significantly reduce production efficiency.
4. CAD / CAM technology liberates the technicians’ numerous calculation drawings and NC programming to produce more creative labor.
Compared with traditional mold industry, modern mold manufacturing and mold industry have new characteristics:
1. High productivity
The productivity of modern molds is much higher than traditional molds. The main reason is that modern molds have multiple stations, multi-cavity molds or multi-functions. For example, there are more than 50 high-productivity advanced molds with 2 positions, and rubber shoe molds with 18 positions. In addition to stamping and forming, a set of multifunctional molds also undertake assembly tasks such as assembly and riveting, and can directly produce assembly parts.
2. High precision
Modern molds require an order of magnitude higher accuracy than traditional molds. The precision of the precision plastic mold of the precision die of the progressive die of the station has reached 0.003mm or even higher. Some high-precision ones, especially those with full inserts, have a long life. Long-life die is the basic condition to ensure high stamping equipment to achieve high production efficiency, modern die life is generally more than 5 million times. The life of hard alloy molds can reach 20-60 million times, injection molds are 400,000-600,000 pieces, and die-casting molds are 500,000-100,000 pieces, while the life of traditional molds is only 1/5 or 1/10 of modern molds.
3. Complex cavity shape and mold structure
With the increasing requirements for product shape, dimensional accuracy, and overall productivity, and the widespread use of many new materials and processes, the cavity structure of modern molds is more complicated.
Based on the above characteristics, we can discover the modern mold industry to become an independent industrial system. The standardization of molds has a high level of specialization, with mold standardization and high-quality mold material production and supply systems. In addition, technical personnel and capital are intensive. The mold has changed from traditional labor-intensive to technology-intensive. Talent-intensive and capital-intensive industries. Technology-intensive is reflected in the CAD / CAM of the mold, and advanced design methods and equipment will inevitably require high-quality professionals to form a talent-intensive. At the same time, high industry is also an important symbol of modern mold. But it will take some time to realize CIMS in mold production. However, with the development and widespread application of CAD / CAM integrated technology and the development of related high-tech, it will be fully implemented in the near future, and automated CIMS will certainly be realized in mold production. Make mold technology, and the entire human mold technology to achieve a new flyby.
Throughout the development of the entire modern mold technology, we can see that mold manufacturing technology is always developing in a new and high direction, and it is accompanied by the development of manual turning to automation. All in all, mold design and manufacturing will completely get rid of production methods that mainly rely on labor, so that mold manufacturing can be more rationalized, the structure is more simplified, and the precision is higher, providing new vitality for the development of various industries in the future.