Coil spring refers to a helical spring made of spring steel wire. There are many types of coil springs, which can be divided into ordinary cylindrical coil springs and variable diameter coil springs according to their appearance; they can be divided into left-handed springs and right-handed springs according to the direction of the helix. The cylindrical coil spring has a simple structure, is convenient to manufacture, and has a wide range of applications. When the load is large and the radial size is limited, two compression springs with different diameters can be used to form a combined spring.
Variable diameter coil springs include conical coil springs, spiral coil springs and concave coil springs. Conical coil springs have better cushioning performance and can withstand larger loads. Spiral coil springs can store more energy and bear larger loads, but the manufacturing process is more complicated. The performance of the concave coil spring is similar to that of the conical coil spring, and it is mostly used for cushions and mattresses. The loading surface of the spring wire is round and rectangular, etc., and the circular section is more commonly used.