At present, widely used spring stress and stiffness calculation formula is derived from the primary material mechanics, stainless steel spring without some practical experience, it is difficult to design and manufacture high precision spring. With the improvement of design stress, many of the previous experience is no longer applicable. In recent years, the FEM (finite element method) design method of more, part has entered the practical stage. In order to construct the material basis of the material, we should strengthen the mechanical basic theory of metal materials. In order to accurately predict the fatigue life and relaxation in the design stage, it is necessary to master the FEM technology as the data base of the choice of material and stress.Raw materials: carbon and alloy materials, poor quality, less variety, incomplete specifications. The raw materials of the factory are not peeled and flawed, the surface and internal defects are serious, the tensile strength fluctuates greatly (up to 10-20N), which affects the spring quality and the enterprise benefit. Raw materials have affected the development of China’s spring industry, the need to improve the quality, the development of varieties, create brand-name, to meet the needs of the industry, alternative imports. Spring material in addition to continue to solve the chemical composition, the main solution to reduce non-metallic inclusions and control surface quality and dimensional accuracy. The main requirement for the spring material is that the spring operating at high strength should have high fatigue life and good resistance to slackness. It should be corrosion resistant, non-magnetic, conductive, abrasion resistant and resistant to different applications. Heat and so on. Products China’s spring product variety is incomplete, mostly for the production of simple structure, easy to shape, the use of some low-tech products, and the structure of the sophisticated technology products are only a few manufacturers have the ability to produce, and the production is far from enough to meet Market demand. Product performance and foreign similar products also have a certain gap, such as the spring load accuracy, vertical accuracy and so there are many gaps, concentrated response in the performance of instability, some important quality indicators of discrete large, unstable life. Especially when the host requires the spring in high-speed, high stress conditions work, the contradiction is more prominent. The future direction of development of the spring should be: high strength, high life, light weight, miniaturization, special parts, assembly. Strengthen the development of new products on the spring, increase the research of new products, continue to expand the spring product variety specifications. Technical manufacturing techniques directly affect spring quality and affect spring design. At present, China’s spring industry, the proportion of technical staff is too low, the technical level of workers is low. Equipment, China’s spring industry, most manufacturers use the equipment are relatively backward, especially the phenomenon of state-owned enterprises is more serious. In particular, testing equipment and testing equipment, the current domestic product accuracy is not reached and incomplete varieties, still can not meet the demand, mainly from foreign imports. At present, the mechanical spring processing equipment and spring processing production line is to NC, CNC of the depth and breadth of development.
Current status of domestic spring industry development
