The production method of processing plastic materials into a large number of uniformly shaped parts is the cornerstone of modern manufacturing. In fact, every market-oriented commodity has at least one shape defined by a mold. However, with the continuous development of the manufacturing industry, molds have become more and more complex, and the required firmness has become higher and higher. The technical difficulty is getting higher and higher, and the product life cycle is getting shorter and shorter. Users also put forward more requirements for mold products, such as: maintenance-free can run for a long time, low energy consumption, wear resistance, easy to install Replacement and greater flexibility, etc.
Under the pressure of market competition and increasing user requirements, mold manufacturers have to choose more practical and effective mold processing methods and adopt more favorable market strategies. As a result, the mold processing industry has shown the following development trends.
1. Globalization
The globalization of the mold market and development is one of the most important characteristics of today's mold industry. Buyers of molds are all over the world, and mold manufacturers are equally ubiquitous. The global development of the mold industry has caused mold processing companies with simple production processes and low precision to migrate to developing countries with relatively backward technology and low productivity. The mold manufacturers that still remain in the United States, Europe and Japan are positioned to produce high-level molds. This is not only a technical requirement, but also a result of competition. Mold manufacturers must face global market competition, which is the driving force for mold manufacturers to pursue efficient application technology.
2. Shorten the production cycle
As we all know, under the same conditions, users are willing to choose products with a shorter delivery time, because users can save more production time, so mold manufacturers have to do everything possible to speed up the production schedule, and strive to simplify and abolish unnecessary Production process.
3. High-speed processing
The "high-speed machining" developed in recent years has had an important impact on the mold manufacturing industry. "High-speed machining" is achieved by a very small stepping distance and a large feed rate. Generally, a high spindle speed can enable the tool to obtain sufficient chip resistance. In rough machining, the use of oblique tools for small width cutting tends to have a higher metal removal rate, and this effect can be achieved even with small tools. In many cases, the surface accuracy of the workpiece after high-speed roughing is very close to the required level, so semi-finishing operations can be omitted.
High-speed machining makes the workpiece obtain a smooth surface and saves machining time. The typical stepping distance is only 0.001in, and the sharp point is only 0.00005in high. Most of the workpiece surface after high-speed processing is very smooth and no need for further work by fitter Processing.
In the finishing process, the increase of the feed rate can avoid the extension of the construction period due to the reduction of the step distance, and the abolition or reduction of the subsequent polishing or grinding process is beneficial to the protection of the processed surface.
Under normal circumstances, the machining tool should reach at least 1200 surface feet per minute, and the spindle speed should not be lower than 8000r/min. The spindle of the old machine tool can reach this level after trimming, but its stability is limited. At present, machining tool manufacturers are keen to produce machining centers specially designed for high-speed machining. In the United States, the use of high-speed processing technology to reduce or eliminate fitter procedures is a measure of considerable benefit, and this technology is also popular in Europe and Japan.
4. Hard milling
Using fully hardened materials to process mold cavities is another important trend in the development of mold processing industry. This is especially valuable for forging dies, because forging dies often require higher hardness than other dies. Roughing and finishing are performed continuously on a machine tool. In the roughing process, the light cutting with high spindle speed and small tool radius forms sufficient torque, which can be used to machine hardness up to 64RC Metal materials; in the finishing process, the smaller stepping distance ensures that the workpiece can obtain an excellent surface finish.
Because the material itself has a certain degree of hardness, electrical discharge machining (EDM) can be reduced or eliminated altogether. Because the material is already hard enough, no heat treatment is required. Not only that, but also the tempering after heat treatment and the grinding process to offset the geometric deformation caused by the heat treatment. This technology is very popular in Japan, and now it has also received widespread attention in the United States and is being spread to Europe.
The high-speed machining of hardened materials puts forward higher requirements for processing tools. Therefore, many machine tool manufacturers have specially designed and developed special grinders for this kind of processing. In the case of high spindle speed and high feed rate, the tool needs to perform light cutting, but thermal stability and high mechanical hardness are also very necessary. In this type of machining, high-pressure coolant is another necessary condition, but there are also some tool manufacturers that use dry cutting to prevent thermal shock to the tool. At the same time, dry cutting can also reduce environmental pollution. Most of these machines are suitable for processing forging dies and small and medium-sized dies.
The forging die used to manufacture the operating rods produced by Japan Asda is made of hardened materials through typical high-speed processing. The size of the workpiece is 164mm×106mm×32mm, and the material hardness is 60RC. Using cemented carbide milling cutter and oil mist coolant, it takes 109 minutes to mill the mold cavity. Although hard milling technology is included, the price of this type of machine tool is relatively high, but only one such machine tool can complete the entire process of rough machining, finishing and electrical discharge machining, which is undoubtedly quite comparable to developed countries like Japan Attractive. It is worth noting that the machining direction of such machine tools is gradually becoming horizontal rather than vertical, which is also a new feature.
5. CAD/CAM tends to be fast and intelligent
CAD/CAM has three obvious development trends, namely: hybrid model, design and manufacturing system database, and workshop site 3D programming.
The demand for hybrid models by industrial companies has been particularly significant in recent years. The use of solid model is of great benefit. It enables material entities with complex structures to be easily expressed and adjusted in the form of an independent entity, and it allows addition and subtraction between entities to generate new solid models. For mechanical engineers, the main advantage of the solid model is that it enables engineers to design products composed of relatively standardized physical elements, such as standard holes, bosses, sleeves, flanges, etc.
The solid model is also of great use to the tool designer. In some cases, the inserted 3D product model can be simply subtracted from the mold cavity in a single operation. Hybrid models allow users to build solids, surfaces, and other graphical elements in a single geometric model. With some CAM systems, users can freely decompose these solid models, or combine all the solids together and process them as a complete solid.
Many American manufacturers have become accustomed to dealing with physical models provided by users, while Europe and Japan are still relatively backward in this regard. However, rapid product updates require the United States, Europe, and Japan to jointly support the development of physical model technology.
6. Database system
For many tool manufacturers, the automated CAD/CAM that can ultimately bring them practical benefits is more important. In terms of mold design, some CAD/CAM system vendors such as American Cimatron Technology Company, British Vero International Company and American Bentley System Company have added corresponding modules to the system to implement conventional CAD/CAM systems The automation function.
At any time during the machining process, because the solid model always exists, the CAM system can compare the workpiece with the solid model at any time. Using the database system, the CAM system can identify where the step distance is too wide in the area between the two tool paths. These areas with too wide stepping distance should be reprocessed in the direction perpendicular to the original processing axis to ensure the best surface quality. Moreover, the continuous existence of the entity database is extremely important for high-speed machining, and for semi-finishing machining, the existence of a permanent entity database is the most ideal thing.
The database system is a highly automated expert system, it contains nearly 10 years of CAM expert experience, it is completed by senior developers, machining tool manufacturers and a large number of user feedback. As a system based on rich experience, the library also provides users with flexible storage functions so that users can add their own manufacturing technology.
7. Workshop on-site programming
In recent years, the CAM system is gradually becoming easier to use, because the CAM system is returning to the workshop site from the CAM design room. Automated tool manufacturers in Detroit and Ontario in North America have shown the most obvious advantages in this regard.
In the past 20 years, many manufacturers initially tried to transfer programming to the CAD/CAM design room where the programming is easier to control. However, with the increasing complexity of cutting tools, NC programming has become a bottleneck restricting industrial development. After the programming was re-transferred to the workshop site, this development barrier was quickly removed, so that combined with practice, programming tools became very easy to use.
In the Detroit area, this new type of on-site programming has led to rapid development of workshop programming. Appropriate use of programming tools cuts down a lot of NC programming time, because most tool paths are created synchronously with the machining process. It saves the repeated correction process between CAD and CAM, enables the production part to obtain an effective NC program, and can give full play to the role of workers and equipment on the production line. More importantly, now the person who creates the tool path is the person who performs the processing. This also gave the machinists the opportunity to implement their machining methods, which made them very satisfied. This helps them make better on-site decisions, choose the most optimized processing method, and modify the processing method in time.
8. Automation
Another important development trend of mold processing is automation, which sounds weird, because most molds are produced in a single piece, it seems that it should require a flexible processing system instead of an automated processing system. But in fact, mold processing has shown the characteristics of small batch production in many aspects.
Recently, many manufacturers have shown a keen interest in an automation system. This kind of automation equipment can continuously and automatically execute operation steps during the manufacturing process without human intervention. The robot automation system is used to load and unload workpieces and Cutting tools are the next goal of many mold manufacturers' automation development.
Nick, President of 3R Systems in New Jersey, USA, said: “Many companies are looking for ways to improve production efficiency and output without increasing fixed costs. Due to the tight labor market and the lack of skilled operators, the fixed production costs of companies are high. In order to improve, automation can increase output through inherent production processes instead of using operators."
9. Electrical discharge machining (EDM)
Electrical discharge machining is known for its excellent ability to handle mold cavities. Wired electrical discharge machining is also widely used in mold production, as long as the mold manufacturer almost has at least one electrical discharge processing equipment. In the past few years, electrical discharge machining technology has developed rapidly, which makes the role and position of electrical discharge machining technology in the mold processing industry more prominent.
Compared with previous years, whether it is stamping electrical discharge machining or wired electrical discharge machining, the development and changes are quite rapid, and their "burning" time has been reduced a lot. In order to achieve unattended continuous operation, the electrical discharge machining system must provide automatic workpiece transposition and electrode transformation functions. This is the main purpose of the mold processing plant to install an automated robot operating system on the electrical discharge processing unit.
The robot automation system used in the fast combustion electrical discharge machining unit consumes electrodes very quickly, so the demand for electrodes is greatly increased, resulting in a lack of electrodes. In the United States, the high-speed processing technology of graphite electrodes is increasingly popular. The reduction and abolition of fitter and polishing techniques have made electrode machining valuable time. More importantly, the abolition of manual work means that the geometric model defined by the machining and CAD will never be lost, and high-speed machining allows manufacturers to follow the user’s requirements. The actual design requires the production of electrodes. If more than one electrode is to be produced, the same product can be "replicated" by the processing system. With sufficient electrodes, EDM can show its skills in mold processing, which is an important advancement in multi-cavity mold processing.
Source: Good marketing copywriter
Note: All pictures in the article are reprinted on the Internet, and infringement will be deleted!
Original link: https://www.xianjichina.com/news/details_236112.html
Source: Xianji.com
The copyright belongs to the author. For commercial reprints, please contact the author for authorization. For non-commercial reprints, please indicate the source.
TOP
首页