With the development of modern industry, the spring in various fields widely used not only in the spring, increasing demand, but also improve the accuracy requirements are constantly in the spring, small electronic products to the railway and aerospace engineering. In the relevant product mechanical and electrical industry in the application is very common, mainly concentrated in the motor vehicle to vehicle based spring, spring to household appliances mainly electronic products and optical device for spring to camera, photocopier and camera based.
 
  The concrete application in mechanical and electrical industry, motor vehicles such as automobile spring, is mainly to the high intensity, light quality and the direction of development, to meet the specific properties required for the vehicle; electronic products spring to appliances, gradually tends to miniaturization, multi-function direction; and the optical device spring tending to higher strength and micro shaped the direction of development. At the same time, the corresponding design method of spring materials and processing technology and other aspects have put forward higher requirements.
 
  Spring design is a prerequisite for the specific application. In the present stage, the spring is widely used in the calculation of stress and deformation formula is deduced according to the mechanical related materials, with the practical application of the design stress increase, a lot of experience in the past is no longer applicable. For example, spring design stress increase, the helix angle increase, will make the fatigue source coil spring inside the transfer to the outside. Therefore, in the spring design must use analytical technology of precision, application of the more common is the finite element method (FEM). For example the characteristics of vehicle suspension spring in automobile based not only required to have enough fatigue life, permanent deformation also has smaller (i.e. anti relaxation property or body centre of gravity shift will occur within the scope of the provisions,) and corrosion on the fatigue life influence. At present, with the increasing of vehicle maintenance period, permanent deformation and fatigue life of automobile spring are made more stringent requirements. And the application of the finite element method can be detailed forecast spring stress effects on fatigue life and permanent deformation, and can accurately reflect the material on the relationship between fatigue life and permanent deformation of the spring. In addition, the introduction of optimization design in spring design process. With the development of computer technology, can carry out the optimum design method of nonlinear programming by computer, and has achieved remarkable results. With the development of technology of forming spring applied and CNC spring machine, spring design will be faced with the impact of new issues such as material, press and shot peening on the fatigue properties and relaxation properties.
 
  Widely used spring processing requirements of more advanced techniques. In the present spring machine processing equipment and corresponding processing production line to NC, intelligent direction with the depth and the breadth development, but with the change of spring material and geometry, put forward higher requirements on the processing technology. Such as variable diameter, variable pitch and variable wire diameter (three) suspension spring to realize non molding processing; hollow stable spring rod made of low carbon boron steel, welding forming rolling; torsion bar with high purity steel 45, obtained by high frequency quenching surface high hardness and residual left a large compressive stress, to improve the fatigue life and anti relaxation ability; spring is widely used in electronic products basically forming punching and automatic bending process using. Is mainly the development of joint technology for composite materials; valve spring main developing multilevel shot peening and liquid nitriding process, in order to improve the surface residual compressive stress, improve fatigue life. The information content source to Kaichuang spring machine: http://www.kcmcnc.com/en/.