Experience sharing and future development of stamping dies, make more reliable Aluminum stamping production
Stamping is mainly used in the production of large-volume parts. Therefore, the stamping die has become an indispensable equipment in the stamping production process and is a technology-intensive product.
The design and manufacture of the mold are directly related to the quality of the stamping part, the production efficiency of the stamping part, and the production cost of the stamping part. In other words, the level of design of the mold and the level of manufacturing technology are also regarded as a very important measure, which is to measure the level of product manufacturing in this country. Manufacturing level plays a decisive role in product quality, benefit and new product development and development ability to a large extent.
If there is a problem in the process of stamping and production, it will directly affect the production efficiency and production cost of the product. Therefore, the design of stamping dies is very important. The good and bad design is directly affecting production, affecting costs and even affecting interests.
1. Overview of aluminum stamping die
1.1 Introduction of the mold
In modern industrial production, mold is one of the important process equipment. Mold industries have occupied an important position, in particular during the stamping process and shaped to type in the molding process. On the whole, in all walks of life in China, stamping dies account for 50%, which can be seen as important. Since China’s reform and opening up, with the rapid development of China’s economy, the demand for molds in China’s market has also continued to grow, and the mold industry has also developed rapidly.
Types of molds:
The types of molds are various, mainly including single-process molds, composite molds, and progressive molds . To determine the form of the mold, it must be based on the requirements of the stamped workpiece, the number of batches required to be produced, and the conditions for mold processing. There are many forms of stamping dies. According to the nature of the work, the structure of the mold, and the materials used in the mold, the stamping dies can be classified into three categories:
According to the nature of the mold process, it can be divided into a punching die, a bending die, a drawing die, and a forming die.
- A blanking die is a kind of die that is separated by a material along a semi-closed or open contour;
- A curved die is a die that bends a material along a straight line;
- A drawing die is an opening made of a stamped part. A hollow shape, or a mold in which the cast hollow is further deformed to change its shape and size;
- The forming die is a mold in which the semi-finished product is directly copied in accordance with the concave-convex mold , but the material is only partially deformed.
Below is a simple illustration of the blanking die:
According to the degree of combination of processes, it can be divided into single process mode, composite mode, progressive mode and transfer mode.
- The single-step mold is a mold that completes only one stamping process in one stroke of the press;
- The composite mold is a mold that can complete two or more stamping processes in one stroke of the press when there is only one working position;
- The progressive die is a mold that can complete two or more stamping operations in one stroke of the press when there are two or more working positions;
- The transfer die is a combination of a single-process die and a progressive die. Woke up.
The mold can also be divided according to the processing method of the product, and can be divided into:
- a punching and bending mold,
- a bending mold,
- a drawing mold, a forming mold,
- a compression mold.
1.2 Introduction of aluminum stamping dies
Stamping dies, which can be referred to as cold stamping dies, are also commonly known as cold dies. Stamping die is a special process equipment. It is processed in the process of cold stamping and finally processed into parts or semi-finished products. The material may be a metallic material or a non-metallic material. Stamping is a method of pressure processing, which is carried out at room temperature. The mold is mounted on the press to apply pressure to the material to separate or plastically deform the material, thereby obtaining the required parts.
The design of the stamping process and the design of the die structure are two aspects of the stamping die structure design. In the production process of stamping parts, the main application of stamping process design, which mainly includes the process plan, how to arrange, the size of the process, the type of equipment and mold used, as well as various technical and economic indicators, these aspects are carried out. A comprehensive master plan, this is the process of stamping process design. While stamping die of structural design is based on the above design stamping process requirements, the design of the desired specific configuration of the mold, shape, and draw the assembly drawing mold part of a mold of FIG.
2. Material selection for stamping die design
2.1 stamping die material
The materials for the stamping die are steel, hard alloy, steel-bonded hard alloy , zinc-based alloy, low-melting alloy, aluminum bronze, polymer material, and the like. Currently stamping die material must most steel-based, commonly used types of die working member material include: carbon tool steel, low-alloy tool steel, high carbon chromium or chromium in tool steel, carbon steel, high-speed Steel, base steel and hard alloy, steel bonded carbide and so on.
2.2 Principles for selection of stamping die materials
In the material used in the stamping die can be of any metal material may be a variety of non-metallic materials, these two materials include carbon steel, alloy steel, cast iron, cast steel, hard alloy, a low-melting alloy , zinc-based alloy, aluminum bronze, synthetic resin, polyurethane rubber, plastic, laminated birch board, etc.
The materials used to make the mold are also very demanding. Not only the hardness, strength and wear resistance of the material are required to be high, but also the appropriate toughness, as well as the high hardenability and the non-deformation of the heat treatment and the difficulty of cracking during quenching.
In order to ensure the service life of the mold, it is necessary to make a reasonable selection of the mold material and to carry out the correct implementation of the heat treatment process. Choosing the right steel grade and heat treatment process should correspond to the different uses of the mold. In addition, it should be based on the comprehensive conditions of its working condition, stress conditions and properties of the material to be processed, production batch and productivity, and should focus on the above description. Various requirements for each performance.
3. Structure of aluminum stamping die
3.1 The structure of the stamping die
According to the role played by the mold in the composition structure, the structural composition of the mold is mainly the process parts, as well as the structural parts.
Process parts are directly involved in the process and are completed. It is also in direct contact with the blank. Process parts mainly include positioning parts, working parts, unloading parts and pressing parts. However, the structural parts are completely different from the process parts. It does not directly participate in the process, nor does it have direct contact with the blank. It only has a guarantee for the completion of the process, or the function of the mold. Structural parts mainly include fastening parts, guide parts, standard parts, and other parts. However, it should be noted that not all stamping dies must contain these six parts.
3.2 Basic principles of stamping die design structure
3.2.1 Safety Principles
When designing the structure of the stamping die, the first thing to consider is safety. It must not be caused by an error in the structural design of the stamping die. Even the actual operator of the stamping die is absolutely not allowed to put himself in a dangerous state. In the punching die of structural design, the design must ensure security of the operator. The mold should also have a certain strength during processing.
3.2.2 Basic requirements
The structural frame should have a uniform thickness; the thickness of the working part of the mold should be uniform and not too thin; the design of the stamping die should meet the standard of bearing capacity; the quality of the structure of the stamping die used should be balanced; of structural material of the frame, the working portion of the material should be selected, since these are likely to wear, therefore be considered a good cost; stamping die having a structure affordability; structural components by calculating the best way to Measurement.
Before determining the structure of the stamping die, it is necessary to determine the feeding mode of the stamping die, as well as the unloading mode and the formwork of the stamping die.
4. The design of aluminum stamping die
4.1 Determination of stamping clearance
Stamping means stamping die gap is concave , convex differential size of the edge portion. The size of this gap has a very large effect on the quality of the single side of the stamping, the amount of punching force, and the life of the mold. Therefore, one of the important process parameters of stamping die design is the punching gap. Therefore, when designing the mold, it is necessary to select the appropriate stamping gap to ensure the quality of the stamping parts, to ensure a small punching pressure, and to ensure the service life of the mold. Appropriate gap values are based on different data, as long as the stamping gap selected is within the proper range in production. In this suitable range, the minimum value is called the minimum reasonable gap value, and the maximum value is the maximum reasonable gap value. In the process of using the mold, it is also possible that the mold is worn out, thereby making the gap larger, so the minimum reasonable clearance value should be used when designing the new mold.
4.2 Determine the dimensions of the embossing die
The size of the working edge of the embossing die of the stamping die is determined by careful calculation.
The structure of the die of the stamping die should be made according to the needs of the part, and the manufacturing method should be based on the above. The fixing of the die is generally fixed directly to the punch .
For example, how to determine the thickness of the die in the manufacturing process of the punching die. The thickness of the die refers to the length of the die edge from the outer edge. Therefore, it is determined that the size of the shape of the die is generally an empirical formula of the die size, that is, H = Kb (H ≥ 15 mm). K represents the coefficient, which can be found in the book; b represents the maximum width of the die hole. In the manufacturing process, not only to calculate the thickness of the die, therewith also to calculate the periphery of the die off data. In this way, a suitable mold structure combination is formed with the main structure of the mold that has been determined. This mold design is greatly simplified.
2) a convex mold
Stamping die convex structure of the mold is needed to press the parts produced, making the method according to the count by out data. Projection fixedly mold generally be applied rivets, may also be secured with a low melting point alloy or a low melting point solder.
Then just install the die and punch position according to the drawing, and other related parts.
5, the future development trend of stamping industry
The future development of stamping die technology should be based on the “fast delivery”, “high precision”, “high quality” and “low price” of the mold products. How can I achieve this? In order to meet the standard requirements of this series, we must develop these items in a timely manner:
5.1. Promote CAD/CAM/CAE technology for molds. The CAD/CAM/CAE technology of the mold can be called the future development trend of the mold design. With the continuous development and continuous improvement of microcomputer software, the basic mature conditions have been reached to make the mold CAD/CAM/CAE technology popular, and each mold industry and enterprise will also increase the training of CAD/CAM technology and its technical services. Development efforts; a wider range of applications for expanding CAE technology.
5.2. Speed up the milling process. In recent years, the high-speed development of the milling industry in foreign countries has greatly improved the efficiency of processing. Not only that, but also the surface finish can be extremely high. In addition, the processing of high-hardness modules also has the advantages of low temperature rise and small thermal deformation. The rapid development of milling technology has added new impetus to the manufacturing of cavity molds for the automotive industry and large and medium-sized home appliance industries. As far as the current level of development is concerned, it has developed toward a higher direction of agility, intelligence, and integration.
5.3. Scan and digitize the mold. The high-speed scanning system of the scanner and mold provides the functions required to scan from the model or the physical object to the desired model, greatly shortening the development cycle of the mold. Some fast scanning systems can be quickly installed on existing CNC milling machines and machining centers to achieve fast data acquisition, automatic generation of various CNC system processing programs, CAD data in different formats, and “reverse engineering” for mold manufacturing. “. The mold scanning system has been successfully applied in the automotive, motorcycle, home appliance and other industries, and it is believed that it will play a greater role during the 10th Five-Year Plan period.
5.4. EDM milling. EDM milling technology, also known as EDM, is a new technology that replaces the traditional cavity machining of shaped electrodes. It is a simple tubular electrode with high-speed rotation for 3D or 2D contour machining. Therefore, it is no longer necessary to manufacture complex shaped electrodes, which is clearly a major development in the field of EDM. Machine tools using this technology have been used in mold processing abroad. This technology is expected to be developed.
5.5. Improve the standardization of stamping dies. The standardization degree of stamping dies in China is still in the stage of continuous improvement. Although the coverage rate of stamping die standard parts in China has reached 30%, it is still far from the other countries, especially developed countries. At present, the stamping dies of developed countries in foreign countries have a coverage rate of about 80%.
5.6. Advanced materials and advanced surface treatment technology. It is necessary to use high-quality materials and application of advanced surface treatment technology to improve the life of stamping dies, such as the selection of high-quality steel materials. The key to the performance of the stamping die steel material is whether it can make the heat treatment and surface treatment of the stamping die more. The future development trend of stamping die heat treatment is the use of vacuum heat treatment technology. It is not only necessary to develop surface treatment technology for stamping dies, but also to develop advanced technologies such as advanced vapor deposition ( TiN , TiC, etc.) and ion coating.
5.7. The grinding and polishing of the stamping die is automated and intelligent. The quality of the surface of the stamping die can be said to have a great influence on the service life of the stamping die and the quality of the appearance of the stamped part. It has researched and invented the automated and intelligent grinding method and polishing method to replace the manual operation. The method can improve the quality of the surface of the stamping die, which is also an important development direction of the stamping die in the future.
5.8. Develop a system for automated mold processing. The development of automated processing of stamping dies can be said to be the long-term development goal of China’s mold industry. The automatic processing system of stamping die is mainly operated by a reasonable combination of multiple machine tools; it is equipped with a fixture for positioning or a positioning plate; the tool and tool CNC of the stamping die are also quite complete; the CNC flexible synchronization system is also Very complete; a fairly complete monitoring and control system for quality.
Since the 1990s, the rapid development of the automobile, home appliances, communications and other industries has also driven the rapid development of the mold industry. The requirements for the development of molds in the world are even more obvious. Nowadays, I have made some achievements in the mold industry, but compared with foreign countries, especially some developed countries, China’s mold technology has not reached the advanced level. Therefore, China still needs more reforms in the mold industry and needs to improve related industries. This requires not only the cultivation of talents in mold design, but also the policy of the policy given by the Chinese government. This will enable the mold industry to develop better.
The design of stamping dies is now a very important industry. The design level of the mold and the level of manufacturing technology are also regarded as a very important measure, which is to measure the level of product manufacturing in this country, so the quality, efficiency and new products of the product are very large. Both development and development capabilities play a decisive role.
Therefore, As one of the most large stamping manufacturer in east China, Sipxmach will pay more attention to the design technology of molds and its development, so as to promote the development of China’s economy.