At present, the processing equipment and production line of mechanical spring are developing towards the depth and breadth of numerical control (NC) and computer control (CNC). However, with the change of spring material and geometry, the processing technology has also developed.
1) The suspension spring with variable spring outer diameter, variable pitch and variable wire diameter (three variations) realizes non molding processing. Since the development of the three variable spring, the tapered steel bar has been used for winding on the CNC lathe, but the finished product and the price are not ideal. Now it is necessary to control the roll speed and drawing force through the coil spring machine under the heating state to obtain the required cone shape and quench with the processing waste heat.
2) The hollow stable spring rod is made of low carbon boron steel plate, rolled and welded.
3) The torsion bar is made of high-purity 45 steel. After high-frequency quenching, high hardness and large residual compressive stress are obtained on the surface, so as to improve the fatigue life and anti relaxation ability.
4) Leaf springs widely used in electronic products are basically formed by stamping and automatic bending. At present, the joint technology of composite materials is mainly developed.
5) The multi-stage shot peening and liquid nitriding processes are mainly developed for the valve spring to improve the residual compressive stress on the surface and increase the fatigue life.
