news
news
2021.7.9
In the process of aluminum alloy die casting production, temperature is one of the core process elements. The quality and production efficiency of the product are directly affected by the temperature control of the die casting die. The selection of the temperature control mode of the die casting die is particularly important. In this paper, based on the actual situation of aluminum alloy die-casting, the temperature control mode of aluminum alloy die-casting die is analyzed in order to realize the heat balance and solve the hot spot problem. Today, we are here sharing everything you need to know about the temperature control method of aluminum alloy die casting mold, the importance, working principle and more.
Die casting mold is the molding process equipment in the casting production process. Whether the temperature field distribution in the mold is stable or not has an important impact on the casting quality, production efficiency and mold service life, which is directly related to the cost and economic benefits of casting production. The temperature field in the mold should be within the range of process requirements, so that the castings with qualified appearance and internal quality can be obtained. On the contrary, if the temperature is too high, defects such as strain and bubble will be formed, which will prolong the cooling time and reduce the production efficiency; If the temperature is too low, there will be cold shut, insufficient pouring, porosity and other defects. Die casting dies are produced in high temperature and high pressure environment for a long time. If the temperature field of the die is unstable, and the long-term periodic thermal expansion and contraction, the die is more likely to fail, which greatly shortens the service life and reduces the production efficiency.
In the casting process, the heat exchange between the mold and the liquid metal reaches the ideal heat balance, that is, the mold achieves the dynamic heat balance when the heat absorbed and discharged are equal. After the process is selected, the mold temperature reaches the working temperature range of the casting, and the place where the hot spot is easy to form is cooled at a fixed point to promote the formation of the heat balance.
– Production position:The casting structure has the highest temperature in the process of die casting, and it is easy to form shrinkage cavity, porosity and stress concentration in the cooling process.
– Control mode – point Cooler: in order to achieve the purpose of water saving, the point cooler adopts the way of water circulation, and in order to ensure the full pressure, the collector and distributor are added.
– High pressure spot cooling is added to the core at the hot spot of the casting.
– Point cooling water treatment: point cooling water in the cooling pipeline will encounter sudden cooling and heating, small pipeline, etc., the old water treatment generally uses softening treatment, often can not meet the water quality requirements in production, point cooling pipe blockage occurs frequently, resulting in huge human, material and financial losses, generally use ro reverse osmosis water treatment device to treat point cooling water into pure water.
Principle
In the process of die casting production, the heat absorbed by the die should be consistent with the heat discharged, so as to prevent the die from getting colder or hotter, and reduce the casting defects such as shrinkage cavity, shrinkage porosity and porosity caused by uneven die temperature. Improve the appearance and internal quality of casting, service life and production efficiency of mould. Achieving heat balance is the process of cooling the mold at high temperature and heating the mold at low temperature.
Control Mode
Die casting mold temperature machine: the mold temperature machine is divided into water type and oil type. The water type is generally selected when the control temperature is about 160 ℃ and the environmental requirements are higher, and the oil type is generally selected when the control temperature is higher than 160 ℃. Generally, the main function of the die temperature machine is to cool the die, which is not enough to adjust and control the temperature in the process of die casting.
Mold Cooling Unit
The mold cooling unit is used together with the cooling circulating water to cool the parts with high mold temperature, so as to maintain the heat balance of mold cavity temperature.
Hand Held Thermal Imager
Conduct thermal imaging test in each shift, and adjust the mold according to the temperature.
Thermocouple or thermal imager temperature monitoring system
According to the mold situation, the thermocouple is embedded in the mold (or the thermal imager is placed on the top and left and right sides of the mold), the mold temperature distribution is monitored in real time through the control system, and the mold temperature is adjusted through the analysis of the monitoring data to realize the mold temperature monitoring.
Mold temperature is one of the most important process parameters, which not only determines the quality of castings, but also seriously affects the service life and production efficiency of mold. Therefore, to ensure that the parameters can be controlled, the automatic temperature control system should be used as far as possible. Die casting mold temperature control is a combination of many ways. It can not be considered that only one way of temperature control can control the mold temperature. Different temperature control methods should be adopted according to the different conditions of die casting production process and die casting mold. With the development of die-casting technology, new temperature control methods are constantly updated. The application of new methods can certainly further improve the level of mold temperature control and contribute to the production of faster and better die-casting parts.