The special-shaped spring contains spring clip, tension spring and torsion spring, and the generalized special-shaped spring also includes snake spring, corrugated spring, bar spring and other complicated springs.Special-shaped spring is the basic part with wide application range and multifarious variety in automobile, motorcycle, electric appliance and instrument products. Its quality and life directly affect the performance of main engine products.Hyundai has made it a key component.
Over 90% of special-shaped springs at home and abroad are made of two kinds of materials: lead quenched carbon steel or cold hardened austenite stainless steel. They do not need quenching, but need low temperature tempering after winding, which can not only eliminate the residual stress in the process of cold drawing, hardening and spring winding, but also simplify the process, so they are widely used.Carbon steel wire and stainless steel wire are mainly classified according to the level of tensile strength. Domestic grade of carbon steel wire is D grade and C grade, while that of Japan and Korea is swp-b and swp-a.Domestic common brands of stainless steel are 1Cr18Ni9, Japanese and Korean common brands SUS302, SUS304.
With the rapid development of automobile industry, the technical content of the special-shaped spring is constantly improving. The entry of WTO makes the foreign automobile industry and the domestic industry more fierce competition. The technical barrier is the current problem, and the self-developed product is the development trend.Different from the valve spring and precision spring, the technical emphasis of the special-shaped spring is different from that of the valve spring and precision spring. It is not under the dynamic load condition of reciprocating work for a long time, but mainly under the static load in assembly. However, size and deformation are the key indexes of the special-shaped spring.So at present, the special-shaped spring is manufactured according to the pattern designed by customers, but the number of products developed jointly with the main engine factory tends to increase.
The quality of raw material is the key to forming the shaped spring.The quality of raw materials affects the supply of springs.Compared with foreign raw materials, domestic raw materials have the following gaps, such as large strength dispersion, obvious bamboo joints, surface folding, etc., which make the size of the manufacturing process difficult to control, and the bending parts are prone to crack or fracture. Stainless steel materials are especially obvious, so imported materials are generally used for processing.