A good set of molds, in addition to ensuring the processing of mold parts, must also do a good job in assembly. If the adjustment is not done well during assembly, it will cause uneven punch clearance, accelerate die wear, and at the same time extrude defective products. There is no specific standard for the maximum number of times aluminum profile extrusion dies can be used. Generally, the following points can be referred to:
1) The quality of the mold steel used
2) Extrusion die design and die manufacturing technology
3) Whether the maintenance of the extrusion die is in place
4) Whether the production process technology of aluminum profile extrusion is guaranteed
5) Whether the management of extrusion dies is appropriate.
If all these five points are to be in the best condition, it is no problem for an aluminum extrusion die to be used for over a million molds. The above five elements not only affect the service life of the die, but also need to be connected in sequence from 1) to 5) one by one.
The number of times the mold can be used and its service life can be improved from the perspective of mold structure design
(1) The overall mold inevitably has concave fillets. When the radius of the fillet is less than 2mm, or when there are concave fillets in the deep and narrow die chamber, or when there are tool marks left during the processing of concave fillets, it is easy to cause stress concentration and thereby lead to cracking.
(2) Within the tolerance range of the blank, in order to reduce the top force of the blank and shorten the time the blank stays in the mold cavity, the mold is appropriately inclined. For example, for the head of a bell-shaped shell product with the same diameter, the upper end size is about 0.1mm larger than the lower end size. The upper diameter of the rod part at the same diameter is about 0.4 mm larger than the lower diameter. This reduces the force exerted at the top of the die and minimizes the surface scratches on the concave die cavity. Reverse slope, that is, inverted tip, is strictly prohibited. Otherwise, it will reduce the quality of the blank, shorten the service life of the mold, and even cause material blockage and mold damage.
(3) The guiding device of the mold is also very important. It can ensure the relative position accuracy of the mold parts during operation, prevent uneven wear of the mold, and a reliable guiding structure is beneficial for avoiding mutual gnawing between the punch and the die, which is particularly important for molds with small clearances. Otherwise, it is easy to cause eccentric loading and mold biting, leading to premature failure of the mold.
(4) Adopting a reasonable gap between the punch and die not only effectively improves product quality but also has a certain impact on the service life of the die. If the gap is too small, it will cause die biting. If the gap is too large, it will not only affect the coaxiality of the product, but also cause the punch to bend due to eccentric loading, thus reducing the punch's service life.
(5) The machining accuracy of the mold is determined by the final polishing process in the mold manufacturing process. The quality of polishing not only directly affects the service life of the mold, but also has an impact on the surface smoothness and dimensional accuracy of the finished product.
(6) Reasonable assembly, commissioning and management
