Die-casting hot molding machine is also called die-casting mold temperature machine. The automatic control of mold temperature by die-casting hot molding machine is an indispensable means in modern die-casting technology. What is the role of die casting hot molding machine in die casting mold temperature control?
First, the pre-heating stage of die-casting mold, the role of die-casting hot molding machine
1. Preheating the mold can reduce the number of hot mold parts, improve production efficiency and reduce waste;
2. Preheating the mold can reduce the thermal shock of the alloy metal liquid on the die-casting mold, prolong the time of the thermal fatigue cracking of the mold, and prolong the service life of the mold;
3. Preheating the mold, the gap of the sliding part of the mold can be expanded and adjusted to prevent the molten metal from drilling into the sliding part and clamping the mold;
The pre-heating mold of the die-casting hot mold machine can effectively reduce the number of hot molds and reduce the thermal shock of molten metal. It is often used on gravity metal casting molds. The die-casting hot mold machine preheats the mold evenly, and has the function of cooling the mold to ensure the stable mold temperature and minimize the thermal shock of the molten metal; it is the standard equipment for the production of aluminum alloy thin-walled parts and magnesium alloy casting molds.
Second, the temperature control stage of die-casting mold, the role of die-casting hot molding machine
If the mold temperature is too high or too low, it will cause defects such as unstable casting size, high scrap rate and reduced yield. When pouring thin-walled castings, the heat sent to the mold tends to be less than the heat lost by the mold, so that the proper molding temperature is not achieved, and the die-casting hot-die machine is required to continuously replenish heat to maintain the mold temperature constant.
In terms of mold temperature alone, there are several effects on the quality of die casting.
A mold temperature that is too low can cause:
(1) The core pressure is too large, and the casting is difficult to demould;
(2) The demolding function of the release agent (commonly known as release material) is deteriorated;
(3) There are cold clips on the surface of the casting;
(4) The temperature difference between the mold and the liquid metal is too large, which accelerates the damage of the mold;
(5) The surface of the mold has a pattern or a mark;
(6) Under casting
Excessive mold temperature can cause:
(1) Sticking mold and deformation;
(2) The consumption of the release agent increases and accelerates decomposition;
(3) Pressing the rhythm to extend;
(4) The active part of the mold is prone to failure and accelerate wear;
(5) There are bubbles on the surface;
(6) There are shrinkage holes inside.
Die-casting hot-mold machines generally use oil as the medium, and the working temperature can reach 320 °C. However, there are exceptions, such as the sprue of the hot chamber die casting machine and the cooling of some cores. In order to prevent fire, pressurized water can be used as the medium, and it is not vaporized at 140 °C. The non-pressurized water cooling system can only be used below 95 °C.
In the die casting process, the casting temperature, filling time, pouring pressure and mold temperature. These parameters are closely related to die casting quality, yield and die life. In the die casting production, the die casting hot die machine improves the quality and process of the die casting by stabilizing the temperature, and its function and effect are self-evident.