Hottest mold making and elastic element 0

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Mold manufacturing and elastic components

the level of modern mold manufacturing and the length of the cycle depend on the support of various technologies, mainly including mold process design, software that directly affects the mold design and manufacturing level, mold manufacturing equipment, standardization and generalization of various accessories, as well as the skill level of mold design and manufacturing engineers and technicians. However, in terms of the requirements for elastic components in mold manufacturing, there are mainly several development trends, that is, the pursuit of high efficiency, high precision, good economy and product flexibility and combinability. Coil spring and polyurethane spring cannot meet the above requirements. With 46 years of nitrogen spring manufacturing technology, dadco company has created a world-class nitrogen spring, which is 40-50% longer in service life and accuracy than ordinary nitrogen springs. Its cost performance is unparalleled

nitrogen spring is a component with elastic function. It seals the high-pressure nitrogen in the determined container, and the external force compresses the nitrogen through the column. When the external force is removed, the high-pressure nitrogen expands to obtain a certain elastic pressure. It has been widely used in advanced mold manufacturing countries such as Japan, the United States, South Korea, Germany, etc. It can improve the service life of the mold and simplify the mold design. Therefore, only dad nitrogen spring can ensure that your mold performance will remain at the top for the next few years

over the years, industrial products have an increasing demand for molds, while the original conventional elastic components have certain shortcomings, which can not meet the needs of this situation and can not ideally solve the requirements of stamping process. This situation often affects the quality of stamping parts, makes the die structure design more complex, and affects the time of die replacement on the press: at the same time, the conventional elastic elements occupy too much die space, which increases the cost of die manufacturing. For example, coil springs and polyurethane springs all need to be pre tightened to reach the elastic pressure required by the design, and their elastic pressure increases significantly with the addition of stroke. This unstable elastic pressure may cause the parts to fail to form, which is very unsatisfactory for the drawing pressure. Another example is that the starting force of coil spring and polyurethane spring is not large, which is not ideal for bending, flanging and other processes requiring relatively large starting force. As a result, the quality of stamping parts is unstable, and adjusting the mold is time-consuming and laborious. For the blanking process of dense punch, such as coil spring and polyurethane spring unloading, we often encounter insufficient unloading space of the mold to place coil spring and polyurethane spring, so we need to increase the mold space to solve this kind of problem. We can also give many examples of this kind. Therefore, people try to develop a new type of elastic functional component to replace the conventional elastic components and complete the difficult work of the conventional elastic components. Nitrogen spring as a new type of elastic functional component came into being. It can be used as an independent part installed in the mold, or it can be designed as a tube type ammonia spring, which works as a part of the mold. It can be easily realized in the system that the enterprise now has 10 industrial parks with constant elastic pressure and delayed action. It is an elastic part with flexible performance. Nitrogen spring can be widely used not only in the mold industry, but also in other industrial fields, such as injection molding, automotive, electronics, instrumentation and other industries. In China, dadco nitrogen spring appears as a high-tech product. Whether we can introduce the application of spring testing machine and ask for insight will become a magic weapon for mold manufacturers to win in the market tide

The structural design and sealing technology of nitrogen cylinder are the key technologies for the quality evaluation of nitrogen spring. At present, the manufacturing technology of nitrogen spring is the most advanced in the United States with dadco, accounting for 60% of the global sales, which is 50% longer than the general nitrogen spring life, and can reach 1million times of spring compression per year. The manufacturing of nitrogen spring is a product that integrates the application of various technologies. Sealing high-pressure gas for a long time is much more difficult than liquid sealing, including the structural form of sealing, the path and form of static sealing and dynamic sealing, the manufacturing precision of cylinder wall, surface roughness, surface treatment technology, the selection of sealing materials, sealing reliability and service life, etc. The characteristic of nitrogen spring is that in a small middle, it can produce a large initial elastic pressure without preloading. The force transfer module has elastic pressure when it contacts with the nitrogen spring plunger at the beginning. A nitrogen spring can replace multiple back-up springs. For the mold with the same working stroke, the height of the mold with nitrogen spring is much smaller than that with ordinary spring: the elastic pressure can be basically kept constant throughout the stroke: according to the requirements of different cold stamping processes, the size of the elastic pressure and the position of the force point can be adjusted accurately and conveniently at any time. In the mold design and debugging, It can easily realize the elastic pressure and balance, simplify the die pressure, unloading and other structures, simplify the die design, and shorten the die manufacturing cycle: improve the quality of stamping parts, ensure the stable quality of stamping parts, shorten the time to replace the die on the press, improve labor productivity, reduce costs, high die accuracy, long service life, safety, reliability, simple, reliable and convenient installation and maintenance

the first problem that should be paid attention to in selecting and applying nitrogen springs in mold design is the choice of elastic pressure. What form of nitrogen springs to choose and how much force of nitrogen springs to choose to meet the requirements of stamping process. To solve this problem, we usually need to consider the elastic pressure of nitrogen springs: the number of nitrogen springs; Pressurization ratio of nitrogen spring. The stroke of nitrogen spring should meet the requirements of stamping process. Different stamping processes require different stroke sizes. The blanking separation process requires large elastic pressure and small stroke: the drawing process generally requires a large stroke. As a function of blank holder force, the nitrogen spring requires its characteristic curve to be relatively dry and slow. In the drawing process, the blank holder force basically changes little, that is, the elastic pressure basically remains constant: for ejection and unloading parts, it requires sufficient force and stroke: in bending and flanging processes, it usually requires a large initial force, In order to press the workpiece and prevent the workpiece from sliding or moving during bending, generally speaking, the stroke is also required to be relatively large. In either case, the total height of the nitrogen spring should not be too high to avoid instability. When installing the nitrogen spring on the mold, the structure is too complex and the tooling cost is increased. If the nitrogen spring is installed in the upper mold, there must be a gap, whether it is the ejector plate or the blank holder, to ensure that the nitrogen spring works smoothly. For safety reasons, avoid accidents, Dadco nitrogen spring suggests that designers should also consider increasing the safety stroke (generally, the safety stroke should be 10% of the piston column stroke) when selecting nitrogen spring, so as to ensure the normal operation of nitrogen for a long time. In addition, attention should also be paid to the selection of nitrogen spring structure. Taking dadco nitrogen spring in the United States as an example, it can be divided into independent nitrogen spring, nitrogen spring seat

plate type, pipeline connection type, etc. These basic structural forms have their own characteristics and a certain range of applications. They need to be comprehensively considered and selected according to the stamping process requirements of parts, the structural form of the die, the use of equipment, working environment, working conditions, the cost of the die and the convenience of adjustment and maintenance. In addition, nitrogen springs should also be selected according to different requirements in the design of cold stamping die. For the same elastic pressure, the nitrogen spring with constant force is more expensive than that with variable force. The longer the stroke of the nitrogen spring with the same specification, the more expensive it is. Therefore, different characteristic curves of nitrogen spring should be selected according to different process requirements, so as to obtain the best price and economic benefits

in the mold design, the transmission of elastic pressure should be balanced. There is often more than one nitrogen spring. Then, the layout of the focus should focus on solving a balance problem. From the perspective of stamping technology, it is also necessary to consider the problem of stamping balance, so as to improve the service life of the mold and ensure the quality of stamping parts. From the use of dadco nitrogen spring in the United States, it is known that the nitrogen spring is in direct contact with parts, and the elastic pressure is transmitted to the working parts of the mold through the designed ejector plate, ejector block, blank holder, wedge block and other mold parts. Then the motion balance of the working parts of the mold such as the ejector plate is related to the arrangement of the force system: on the other hand, the ejector plate also plays the role of transmitting force to the nitrogen spring, Therefore, in order to avoid the eccentric load of nitrogen spring, improve the eccentric load bearing capacity of nitrogen spring, and ensure the service life of nitrogen spring, the design method that the center of nitrogen spring pressure system coincides with the center of impulse pressure should be adopted

nitrogen springs need considerable stability and reliability both in installation and operation. Precisely because of its large elastic pressure, a nitrogen spring will release hundreds of kilograms or even tons of force in a small volume, and this process is repeated. Therefore, it is very important to maintain the stability of its work, especially the nitrogen spring with large force, which must be firm, In particular, if the nitrogen spring is reversed or installed on the upper mold, the nitrogen spring needs to move relatively with the movement of the slider. Only a firm connection can ensure the normal and stable operation of the nitrogen spring. Therefore, it is often designed to install nitrogen springs, or the cylinder block or the plunger is provided with a certain depth of installation counterbore to ensure its positive position and avoid deflection. It should be said that the working nature of the nitrogen spring belongs to the flexible category. During the working process of the mold, the opening and closing should be relatively smooth, and there should be no impact phenomenon. In order to achieve this purpose, for the use of independent nitrogen spring, the designer should fully consider this point

because as mentioned above, the frequency of the nitrogen spring is correspondingly high, and the elastic pressure can be generated when the part contacts the nitrogen spring plunger rod, There is no need to have a pre tightening process at all, so with the up and down movement of the slider of the press, the opening (expansion) and closing (compression) responses of the nitrogen spring are very fast. If the design is improper, especially when using the nitrogen spring on the small tonnage press, it may appear that the helium spring pushes the slider to use, which is convenient and fast for the return of the slider, destroying the curve of the slider of the crank press, resulting in vibration and shock, Therefore, we should try our best to avoid this phenomenon

mold manufacturing all over the world is developing rapidly in the direction of precision, complexity, efficiency and long life. We hope that domestic mold manufacturers can make full use of foreign advanced technology and products to make our own world-class molds

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