Whether the structure of cold stamping die design is reasonable or not plays a key role in the success of precision hardware production. Even a group of simple die parts has dozens of components, so their accuracy cannot be underestimated in design.
At the beginning of the design, what kind of mold structure should be selected? Is it the front die structure (i.e. the female die is installed on the lower die base)? Or inverted (reverse) die structure (i.e. punch installed on the lower die base)? Or choose a single process die structure? Or should we choose a compound die structure? This is a topic worthy of in-depth discussion for each of our mold workers, and this is a great article.
When to select positive mold structure.
Structural Features of Front mounted Mold
The structural feature of the front die is that the concave die is installed on the lower die base. Therefore, the workpiece or scrap can easily fall into the scrap hole on the punching table, whether it is used for workpiece dropping, punching or other processes.
Therefore, it is not necessary to consider the flow of workpiece or scrap when designing the main die. This leads to a very simple and practical tool structure.
Advantages of positive assembly die structure
- Because the die structure is simple, the die manufacturing cycle can be shortened, which is conducive to the development of new products.
- It is more convenient to use and maintain.
- It is easier to install the punch and die and adjust the clearance (compared with the reverse die).
- The mold manufacturing cost is low, which is conducive to improving the economic benefits of enterprises.
- Because the pressing force always exists during the whole stretching process, it is suitable for stretching non rotating body parts.
Disadvantages of positive die structure
- As the workpiece or scrap is stacked in the die hole, the group lift in the die hole is increased. Therefore, the concave surface must increase the wall thickness to improve its strength.
- As the workpiece or scrap is stacked in the die hole, the die edge must be machined with the drop slope. In some cases, the reverse hole (discharge hole) on the die edge must be machined, which extends the cycle time of the die and increases the processing cost of the die.
Selection principle of positive mold structure
To sum up, we can see that the design principle we should follow when designing the stamping die is to give priority to the positive die structure. Only when the front mounted mold structure can meet the technical requirements of the workpiece, can other mold structures be considered.
