The comparison of the four elastic components shows that: (1) The spring needs to be pre-tightened when used, the elastic pressure is linear with the stroke, the increment is large, the spring pressure cannot be adjusted, and the spring life elastic component characteristic curve is relatively short. (2) In addition to the similar problems with the spring, the rubber component also solves the problem of lateral expansion when the rubber is compressed. (3) Press air cushion can solve the problems of the above two elastic components, but its cost is high, and it can only be used in the lower mold, and the pressure adjustment is not accurate enough. The mold design is also subject to the position of the ram. (4) The nitrogen gas spring has a large initial spring pressure without pre-tightening. The pressure increment can be controlled by design, and a relatively constant pressure can be obtained, which is not restricted by the stroke length, and the pressure is adjustable and the service life is long. High efficiency, stable stamping quality, and many conveniences for mold design, manufacturing, installation and adjustment. Introduction to Nitrogen Gases Nitrogen springs can be classified into stand-alone nitrogen springs and seat-plate nitrogen springs according to their applications. The independent nitrogen gas spring is a separate unit for each nitrogen gas spring. The non-independent nitrogen gas spring is a combination of several nitrogen gas springs through a nitrogen spring seat plate, or a plurality of independent nitrogen gas springs are connected by a hose. Become a nitrogen spring system. There are many brands and specifications of nitrogen springs in the international market, such as /KALLER independent nitrogen gas springs, divided into TU type, SL type and other eight types, its working stroke range is 6300mm, elastic pressure 510123127N, cylinder outer diameter @ total The height is <25mm@65mm<150mm@740mm. It is used in this article / Kailong 0SL type nitrogen spring Jane 1 plunger 21 cylinder head 31 cylinder 41 inflatable port 51 cylinder bottom KALLER / SL0 type nitrogen spring diagram. Nitrogen spring selection This paper takes the secondary drawing die of the microwave oven door shell as an example to illustrate the type and structure selection process of the nitrogen gas spring. The final assembly drawing for the second deep drawing die of the microwave oven door shell. Microwave oven door shell second deep drawing die 1. Nitrogen gas spring 2. Punch 3. Pressing edge ring 4. In the concave die diagram, the nitrogen gas spring applies the elastic pressure to the crimping ring to generate the deep drawing blanking force, and the nitrogen spring is selected. The following issues should be considered when considering the type. The pressure of the gas spring is calculated according to the size of the part. The pressure is theoretically calculated as P=240000N. Generally speaking, it cannot be directly selected according to the calculated blanking force. It should be given a certain increment, and the incremental force of the blanking force is 1.151.20. Therefore, the blanking force is selected as the number of F=280000N gas springs. After selecting the blank holder force, the number problem needs to be solved. NP0=FN nitrogen bomb number, P0 nitrogen rated spring pressure, NF blanking force, NN selection, should be optimized according to the formability requirements of the parts, structural conditions, try to make the whole force system basically balanced, mold installation, adjustment Convenient and low cost, it should also be considered that the selected model can meet the requirements of stroke and boost ratio. The selection of the supercharging ratio is a deep drawing process. Therefore, the supercharging pressure is required to be small, and the elastic pressure is basically stable. In this example, the supercharging ratio is selected as K<0.5, so the independent nitrogen gas spring KALLERSL produced by Kairon 0 is selected. Type nitrogen gas spring, model SL1500-25, its main parameters are: stroke 25.4mm, initial force 15648N, maximum force 22697N, K=0.45. Thus the number of nitrogen springs is N=18. The type of nitrogen spring system chooses to connect the gas springs into one or more systems, and in each system loop, the gas springs have the same pressure, which is a large point from the point of view of stamping technology and maintenance and safety. advantage. The nitrogen spring piping system is divided into JIC and EZ piping systems. If a pressure storage tank is used in the system, the JIC piping system is generally used. In this paper, the EZ pipeline system is adopted, which is connected with the independent nitrogen gas springs by a high-pressure pipe, and a control table is installed, so that the pressure-clamping force regulation is conveniently carried out, and the application in the drawing die is good, and the following focuses on the introduction. The design process of the EZ piping system. Conclusion This paper automatically calculates the squeezing force of the ferrous metal positive extrusion by computer, which greatly reduces the burden on the process designer and lays a solid foundation for the computer intelligent design of process design and mold design.