Die casting die accessories belong to a process method of casting liquid die forging and completed on a special die casting die forging machine. For die casting, three elements, namely die casting materials, die casting machine and die, are indispensable. In order to improve production efficiency, brand quality and high economic benefits, and to extend the service life of die casting die fittings, the use and maintenance of die casting die fittings are very important.
Correct use and maintenance of die casting die accessories:
1. Try to reduce the quenching and heating of the mold, and make continuous production as much as possible. In the cold mold state, high-speed injection is strictly prohibited.
During the die-casting process, the accessories of the medium pressure casting die have been in the reciprocating fatigue state of thermal expansion and cold contraction. The temperature of the mold cavity has basically been changing back and forth between 160 ° and 350 °. The mold is rapidly cold and hot, constantly expanding and shrinking, resulting in mold fatigue damage. When the production starts in the cold mold state, the mold temperature starts to rise from the low temperature, the temperature difference increases, the mold expansion and contraction increases, and the mold fatigue increases correspondingly, which will speed up the mold damage and shorten the mold life. Therefore, the die casting production should be as continuous as possible to reduce the quenching and heating of the die, so as to extend the life of the die.
In addition, in the cold mold state, the mold does not reach the temperature during normal production, and the gap between the parts of the mold is relatively large. In this case, it is strictly prohibited to open high-speed injection and pressurization. Otherwise, the clearance parts of the mold, including the slider, the ejector pin hole and other parts are easy to enter the aluminum sheet, which will damage the mold and affect the life of the mold.
2. Try to reduce the injection speed, specific pressure and die impact.
During die casting production, the injection speed not only affects the filling speed and injection ingate speed of die casting, but also increases the impact peak value when the injection speed is high. Therefore, the injection speed is high, the injection inner gate speed is fast, the mold erosion will be intensified, the impact peak value will be increased, the impact force on the mold will also be increased, and the mold life will be greatly reduced. Therefore, when adjusting the die casting process, we should try to reduce the injection speed while ensuring the product quality, which is very important for improving the die life and improving the economic benefits of the die casting enterprise. At present, the advanced die-casting machine is equipped with injection brake device, which is very useful for reducing the peak impact, reducing the impact force on the mold, and improving the life of the mold.
The injection specific pressure in the die casting process is also an important parameter. The injection specific pressure is generally 400-900 kg/cm2 according to the casting quality requirements and characteristics. If it exceeds 900kg/cm2, it generally has little effect on the internal quality of castings. However, if the injection specific pressure is too high, the die will not only bear more expanding force, but also exceed the clamping force of the machine tool, resulting in aluminum channeling. At the same time, if the die bears a large expansion force, it will also damage the die or shorten the life of the die. Therefore, in die casting production, we should pay more attention to the injection specific pressure in addition to the injection speed. Because the injection specific pressure is not as easy to observe as the injection speed, it is often ignored. In fact, the injection specific pressure is an important parameter in the die casting process, which not only affects the casting quality, but also has a huge impact on the mold life. This should be paid more attention to by die casting enterprises.