In production practice, once some molds are put into pr […]
In production practice, once some molds are put into production line, they often have various problems, can not satisfy the production requirements or technical requirements of the products, resulting in abnormal strike of production line, and many unstable factors. Therefore, how to improve the stability of the mold has become a real problem faced by the mold manufacturing enterprises.
The experience and technology of designers play a key role in the design and production of dies. Whether the design is reasonable or not can be recognized only through mold testing, while the mold needs to be tested and corrected many times before it is finally completed. In production practice, once some molds are put into production line, they often have various problems, can not satisfy the production requirements or technical requirements of the products, resulting in abnormal strike of production line, and many unstable factors. Therefore, how to improve the stability of the mold has become a real problem faced by the mold manufacturing enterprises.
What is stability stability divided into process stability and production stability. Process stability refers to the process plan that can produce qualified products with stability, while production stability refers to the production capacity with stability in the production process.
Let's first look at the main factors that affect the stability of die and stamping. They are: application method of die data; strength requirements of die structure; stability of stamping data function; fluctuation characteristics of data thickness; change range of raw materials; resistance of tensile tendon; change range of blank holder force; selection of lubricant.
It is worth noting that in the stamping process, because each kind of stamping plate has its own chemical composition, mechanical function and characteristic value closely related to the stamping function, the function of stamping data is not stable, the thickness fluctuation of stamping data and the change of stamping materials, not only directly affect the accuracy and quality of stamping processing, but also may cause die damage. 。
Taking the stretch rib as an example, it plays a very important role in stamping. In the process of stretch forming, the forming demand of the product has a certain size and appropriate distribution of tension along the fixed periphery, which comes from the effect force of the stamping equipment, the deformation resistance of the edge part of the data, and the movement resistance on the blank holder surface. However, the friction between the die and the data is not enough if the action resistance only depends on the effect of the blank holder force.
Therefore, it is also necessary to set a tensile bar on the blank holder which can produce a large resistance, so as to increase the resistance of the feed, and then make the data have a large plastic deformation, so as to meet the requirements of plastic deformation and plastic activity of the data. At the same time, by changing the size and distribution of the tensile rib resistance, and controlling the speed and feeding amount of the data moving to the die, the tension and its distribution in each deformation area of the drawing part can be effectively adjusted, and then the quality problems such as cracking, wrinkling and deformation of the product during the stretch forming can be prevented.