（1） Application prospect of die spring
It can be seen from the above introduction that the number of circular section steel wire die spring will continue to decline. ② The diameter of special-shaped cross-section spring is larger than 10, which will increase and has strong vitality. ③ Because of its unique advantages, the number of rubber springs will be increased. Therefore, the international organization for standardization published the standard of rubber spring for mould in 1990 (ISO / dii0069… – 1). ④ The application prospects of nitrogen spring and butterfly spring in mould need to be discussed after practice. ⑤ The number and scope of application of special-shaped section die spring will be further increased.
（2） Technology development prospect of special shaped section die spring
1. In the theoretical design, the static strength design will be broken through, and the safety life design and damage tolerance design will be further developed.
2. Spring material of special-shaped section cylindrical mold
a. Section shape
Square section was eliminated, rectangular section was replaced by s, D, s, shape in Japan, flat section material has a wide market in Britain, the United States and other places
b. Chemical composition
At present, it has broken through the common CR-V steel (50CrVA of China, aisig150 of the United States, sup10 of Japan, ds735aso of the United Kingdom, 50CrV4 of Germany, Г ct50x ф a of the Soviet Union, etc.) and vigorously adopts Si Cr steel with good hardenability and impact resistance (sup12 of Japan, 9254 of the United States, typeID of ISO, in which the content of Si is 1.2 “1.7%); The content of Cr is 0.5 “0.8%. At the same time, the piano steel wire and steel wire with the same properties (especially for the mold used in the normal temperature environment) have been applied (see jisb5012-86 standard for details).
3. Comparison of processing equipment and materials at home and abroad: (1) processing equipment: machinery in foreign countries; semi machinery in China. (2) Material: heat treated abroad; annealed at home.
（3） Market forecast of special section strong die spring
1. Domestic market forecast
A. At present, there are more than 6000 mold manufacturing sites in China (excluding villages and towns and individual mold factories), with more than 300000 employees and a total output value of more than 4 billion yuan. The annual output of various types of molds is more than 1 million sets (excluding simple molds). If the spring output value accounts for 1% of the total mold output value, it will be more than 40 million yuan per year. From a long-term point of view, the market has great potential.
B. From the analysis of the localization of imported die spring, at present, the general mold can basically meet the domestic needs, but most of the large, precise, complex and long-life dies, such as multi position progressive die, large-scale precision plastic mold, complex die-casting mold, automobile cover part mold, still need to be imported. According to the quantitative analysis, Japan accounts for 30%, Germany accounts for 20%, and the United States, Britain, Switzerland and other countries account for about 50%. According to the relevant information, there are about 8 million dollars of mold spring cost (including spring spare parts) every year. If 20% of the springs are localized, the foreign exchange will be saved by US $160.
2. Export market forecast
Die spring is a labor-intensive product in foreign countries. Its price is generally higher, about 2 “3 times higher than that in China. Therefore, in recent years, a small number of springs have been exported, but most of them are light load, small size and flat cross-section. From a long-term point of view, there is a certain market for export mold spring.
（4） The prospect of developing special cross section powerful die spring in China
Compared with other parts industry, the industrial technology of spring industry in China is quite backward. The original foundation is very poor, and the spring is produced by semi mechanical processing. This is bound to affect the high-speed development of the whole spring industry, and also affect the development of a new spring product – special-shaped cross-section spring. In order to develop, develop and mass produce die spring, the following problems should be solved
1. In product manufacturing, standards are the basis to ensure product quality. At present, the spring manufacturers formulate their own technical standards and cross-section specifications, which hinders the development of special-shaped cross-section die spring. It is suggested that the competent department should make overall planning and arrangement for this, formulate relevant national standards and product specifications as soon as possible, so as to ensure the spring quality and facilitate the selection and use of users.
2. The material is the “grain” of the spring factory, which directly affects the spring production. Please develop and produce the die spring as soon as possible so that the die spring can be widely used, so as to reduce foreign exchange and go to the world.
3. It is suggested that the Ministry of mechanical and electrical engineering should incorporate the research and development of special-shaped cross-section spring coiling machine into the plan, and issue it to the designated factories of spring processing equipment for implementation.
4. Professional spring factories are all small factories with about 100 employees, and there are no more than 700 employees in China’s spring factories which have been established for more than 50 years. Therefore, it is limited to rely solely on enterprise funds for scientific research. It is suggested that the state should support some qualified manufacturers, increase development funds, and develop special research on die spring design theory and technology.
5. In recent years, the sales of special-shaped cross-section spring in the domestic market “situation” is very good. Enterprises that have been one step ahead in mold spring manufacturing can use their own advantages to enter the international market,
6. At present, the number and scope of the application of special-shaped cross-section spiral spring is expanding, while the application quantity and range of circular cross-section steel wire spiral spring is declining. The application quantity of rubber, especially polyurethane rubber spring, is steadily increasing, while butterfly spring and nitrogen filled spring are in the development stage. For each specialized factory, corresponding planning should be made according to the technical and equipment specialty of the unit. “Leave it alone” or “herd” will bring unnecessary losses to enterprises.