There are many factors that affect the life of the mold […]
There are many factors that affect the life of the mold. These factors should be considered comprehensively when designing the mold, so as to design a more economical and efficient mold. For special-purpose cold stamping molds, an economical and applicable mold should be designed according to its own requirements.
1. Correctly choose mold materials
The working condition of the punch is worse than that of the concave mold, and the material of the punch is better than that of the concave mold. When blanking in large quantities, it is necessary to pay attention to the selection of mold materials that have high strength, good wear resistance, and good toughness.
2. Reasonable cold stamping die design structure is an essential prerequisite to ensure the service life of the die
The service life of cold stamping die has a great relationship with reasonable structural design. At the beginning of the design, other design requirements of cold stamping die are guaranteed. The toughness, rigidity and strength of the mold must be guaranteed to ensure that the convex, concave and other structural parts of the mold during the blanking process of the cold stamping die will not be deformed, damaged or increased wear due to the impact of the punching force. The mold design should use guided mold design as much as possible, and the mold design gap should also be considered. If the design gap is too small or too large, it will increase the degree of wear of the convex and concave molds, which will lead to mold damage and reduced service life.
3. Use and maintain molds reasonably
In the stamping process, the cold heading blank should be phosphated or copper-plated in order to reduce the friction resistance during work and prevent the adhesion of the mold. Therefore, the metal plate must be preheated to improve the processing performance of the material before cold heading. Reduce the possibility of cracks and extend the life of the mold. Lubrication during cold heading is also a good method. Good lubrication can obviously increase the surface finish of the metal sheet, reduce friction resistance, reduce wear, and extend the service life of the mold. When cold heading parts with complex shapes, lubrication becomes even better. Is important.
When the mold is stored, a certain gap should be maintained between the upper and lower molds to protect the cutting edge from damage. When punching, the depth of the punch into the concave mold should be controlled well to avoid increased wear. In the stamping practice, after stamping and stamping for a period of time, the edge of the concave and convex die will be worn and worn out. If the mold is repaired at this time, it will not only reduce the frictional resistance and prevent cracks caused by wear groove marks, but also avoid the additional bending moment caused by the uneven gap between the die and the punch after wear, and extend the use of the mold. life. After the cutting edges of the concave and convex molds are ground again, the gap between the cutting edges becomes more uneven. At this time, the cutting edges should be carefully ground and polished with fine oil stone to remove the grinding burrs. Generally speaking, the surface roughness value should reach Ra≤0.10μm or less, so as to eliminate the hidden danger of cutting edge wear of the concave and convex die immediately.
4. Good lubrication conditions
Good lubrication can prevent the mold from rusting, reduce frictional heat, friction, and punching force, reduce mold wear, and extend mold life. For example, when punching silicon steel sheets in transformers, if the lubrication is good, the life of the mold is about 15 times that of the mold with poor lubrication. In addition, the proper use of lubricants can also extend the life of the mold. For example, when the squeezing operation is performed on the surface of stainless steel, if the squeezing operation is lubricated with general oil, only 90 pieces can be produced during the life of the mold; if it is lubricated with molybdenum disulfide lithium-based grease, it can produce about 1.2 Ten thousand pieces, the two are very different.
5. Processing and assembly quality of cold stamping dies
The service life of a cold stamping die is directly proportional to its machining accuracy and quality. The higher the accuracy and quality, the longer the service life. In the process of mold installation, we must strictly control the gap between the male mold and the female mold to reduce wear.
6. Use and maintenance of cold stamping dies
The correct selection of the right, high-precision stamping equipment and the right pressure can effectively extend the service life of the mold. At the same time, in order to reduce wear and tear, suitable lubricants can be applied to the stamping plate. The mold should be sealed and stored when not in use, and properly protected.