A spring is an elastic element that serves to absorb or accumulate mechanical energy. They make it from a material having high strength and elasticity. In order to maximize spring stiffness, high-carbon alloy steels are used in its production . In practice, there are situations when the elastic element is used in an environment that has high aggressiveness. In such cases, it must be made of stainless steel or bronze. Small springs can be wound from wire. But powerful elastic elements to give them greater endurance must be made from annealed metal. In addition, after molding, such springs are additionally hardened.
By the type of loads that affect the elastic elements, they are divided into separate groups. Allocate springs:
-compression;
sprains;
torsion;
bending.
The design of the compression elements is designed to reduce their length when exposed to a specific load. At rest, their turns do not touch each other. A spring, the compression of which can cause a loss of stability, is installed in special glasses or on mandrels. The ends of this element are subjected to special grinding, and the turns located at the ends are pressed to neighboring ones.
The tension spring is calculated for the load, the result of which is an increase in its length. At rest, the turns of such elements are closed to each other. The design of the spring provides rings or hooks to secure it. They are located at the ends of the extreme turns.
Torsion and bending springs transform the energy of deformation, repeatedly strengthening the elasticity of the material from which they are made. This process is possible by increasing the length of the turns.
Spring stiffness is a physical quantity. It characterizes the labor force of an elastic element with one millimeter of tension or pressure. In this case, the spring stiffness is a value proportional to the force of impact. The law establishing this concept was discovered by physicist from England Robert Hooke. According to his theory, stretching a spring is equal to the force acting on it.
Elastic elements find their application in various fields. So, for example, in the production of orthopedic mattresses, springs are used, the design of which is designed to work under the action of compression forces. At the same time, to create the greatest comfort, the spring stiffness, which is installed in places subjected to the greatest deformation, is maximum. And, conversely, in places where the pressure of the body is minimal, set the spring with the least rigidity.
The elastic elements are widely used in the manufacture of automobiles. They play an almost decisive role in the behavior of the vehicle on the roadway. Suspension springs are designed to create a force that prevents body roll. In cases where the stiffness of such a spring is too high, the car may swing unnecessarily. At the same time, passengers negatively perceive each hole or tubercle on the carriageway. In order to improve the handling of the vehicle, it is necessary to reduce the stiffness of the suspension. As a rule, the selection of the spring is carried out in such a way that the smallest distance between its coils exceeds six and a half millimeters. It is possible to determine the stiffness of an elastic element using floor scales, a hand press and a ruler.
Nowadays, springs having a variable pitch of coils along the entire length are often used. Under static load, the whole element as a whole provides the necessary suspension stiffness. With an increase in the force of action, the coils with a smaller step are closed and their working quantity decreases. This increases the stiffness of the spring. In the manufacture of sports cars, elastic elements with turns having various steps are also used. This provides the greatest possible adjustment of the chassis.