The development of hardware spring manufacturing requires technological innovation:
With the rapid development of the hardware spring manufacturing industry, the production technology of hardware springs will usher in new changes. The previous production methods of coarse ore are no longer suitable for the needs of the current market. Development only requires continuous innovation of technology.
At present, the widely used hardware spring stress and deformation calculation formulas are derived based on material mechanics. Without certain practical experience, it is difficult to design and manufacture high-precision springs. With the increase of design stress, many previous experiences No longer applicable.
The spring finite element analysis method has been put into practical use in countries with higher spring technology. Although my country has technological development in this area, it has not yet formed a practical model. In addition, optimized design has been introduced in the spring design process.
The structure of the spring is relatively simple, the function is simple, and the parameters that affect the structure and performance are few. Therefore, the designer used the analytical method, graphic method or graphic analysis method to find the optimal design solution very early, and achieved certain results. The development of non-linear programming using computers has achieved results. Reliability design is a series of analysis and design techniques used to ensure the reliability of the designed product. Its function is to predict and prevent possible product failures. On the basis of the design, making the designed product reach the specified reliability target value is a supplement and improvement to the traditional design method.
For example, after the design stress of the hardware spring is increased, the helix angle is increased, which will transfer the fatigue source of the spring from the inner side to the outer side of the coil. For this reason, the precise analysis technology of the spring must be used, and the current widely used method is finite element Method. The characteristics of vehicle suspension springs are that in addition to sufficient fatigue life, their permanent deformation should be small, that is, the relaxation resistance should be within the specified range, otherwise due to the different deformation of the spring, the center of gravity of the body will deviate.
At the same time, it is necessary to Consider the impact of environmental corrosion on its fatigue life. With the increase of vehicle maintenance period, more stringent requirements are put forward for permanent deformation and fatigue life. For this reason, high-precision design methods must be adopted. The finite element method can predict the spring in detail. The influence of stress fatigue life and permanent deformation can accurately reflect the relationship between the material’s fatigue life and permanent deformation of the spring.
In recent years, the finite element design method of springs has entered the practical stage, and there have been many reports of practical value, such as the influence of helix angle on spring stress; the relationship between stress and fatigue life calculated by finite element method, etc. It is shown as a comparison between the calculation of the current design method and the analytical stress of the finite element method.
For the spring of the same structure, under the same load, it can be seen from the figure that the stress of the high-stress spring with fewer effective loops or large helix angle, The results obtained by the two methods are quite different. This is because as the helix angle increases, the load eccentricity is increased, so that the outer diameter or lateral deformation of the spring is larger, so the stress is relatively large. The current design calculation method cannot be accurate. The finite element method can be more accurately reflected.
Spring design has made some progress in the use of reliability technology, but further improvement requires the development and accumulation of data. With the development of computer technology, various versions of spring design programs have been compiled at home and abroad, which are hardware spring technology The personnel provide convenient conditions for development and innovation. The application design program has completed the development of arc-shaped clutch springs and drum-shaped suspension springs that are difficult to design. With the development of spring application technology, designers have also raised a lot of attention And new problems solved.
For example, the influence of materials, strong pressure and shot peening on fatigue performance and relaxation performance is difficult to calculate accurately during design, and it depends on experimental data. Another example is the number of turns calculated according to the current design formula, and the stiffness of the spring produced is higher than the design The stiffness value is small, and the effective number of turns needs to be reduced to meet the design requirements. The current design trend of mass production products takes the maximum working shear stress and fatigue life requirements as examples.