An inclined coil spring is a mechanical part that uses elasticity to work. Parts made of elastic materials deform under the action of external forces, and return to their original shape when the external force is removed. The types of bevel coil springs are complex and diverse, according to the shape, mainly including spiral bevel coil springs, vortex inclined coil springs, plate inclined coil springs, special-shaped bevel coil springs, etc. It is generally made of beveled coil spring steel. So what are the requirements for the material used to make the bevel coil spring?
1 high intensity
In order to improve the ability of the inclined coil spring to fatigue damage and relaxation, the bevel coil spring material should have high yield strength and elastic limit, especially a high yield ratio. Under normal circumstances, the elastic limit of a material is proportional to the yield strength, so bevel coil spring designers and manufacturers always expect a material with high yield strength.
2. Good plasticity and toughness
In the manufacturing process of beveled coil springs, the material needs to undergo different degrees of processing deformation, so the material is required to have a certain plasticity. For example, the hook loop and torsion arm of the stretched and torsional bevel coil spring with complex shapes, when the radius of curvature is very small, when processing winding or stamping bending forming, the bevel coil spring material must not have cracks, damage and other defects. At the same time, when the beveled coil spring is subjected to shock load or variable load, the material should have good toughness, which will be of great benefit to improve the service life of the bevel spring
3. Excellent surface condition and fatigue performance
The sloped coil spring works when the surface is subjected to a large stress, and fatigue damage often starts from the surface of the wire, for the use of important occasions of the slope coil springs such as valve inclined coil springs, valve inclined coil springs and suspension inclined coil springs are required to have millions of times, tens of millions of times or even longer cycle life, which puts forward high requirements for the fatigue performance of the material. There are many factors that affect the fatigue properties of materials, such as the chemical composition of materials, hardness, purity of steel, surface quality and metallographic structure, etc., and the surface quality of materials is particularly important.
4. Strict size
Many inclined coil springs have high requirements for load accuracy, such as the load deviation of the valve inclined coil spring shall not be greater than 5%-6% of the specified load, taking the pulling and pressing inclined coil spring with round steel wire as an example, if the wire diameter deviation is 1%, the load will produce a deviation of about 4%. It can be seen that strict dimensional accuracy is also very important to ensure the quality of the bevel coil spring.
5. Good uniformity
The uniformity requirements of materials refer to the requirements for uniformity and stability of various indicators such as chemical composition, mechanical properties, and dimensional deviations of materials. If the performance of the material in all aspects is inconsistent, it will bring great difficulties to the production of beveled coil springs, resulting in discreteness of product geometry, hardness, load and other parameters, serious unevenness and even waste products.
