Hot chamber die casting machines are mainly used for melting low-temperature alloys such as zinc, tin, and lead. If the molten alloy with a high melting point is easy to damage the pump that is in direct contact with the molten metal. The metal is packed in an open holding pot, which is placed in an oven, where it melts to the desired temperature.
The molten metal alloy then flows into the shot blasting chamber through the inlet and plunger, which is hydraulically driven to force the molten metal into the mold through the gooseneck channel. The injection pressure of the zinc hot chamber die casting machine is generally between 1000 and 5000 psi.
After the molten metal is injected into the mold cavity, the plunger maintains pressure while the casting is solidified. After curing, the hydraulic system retracts the plunger and the part can be ejected through the clamping unit.
The first half of the die casting mold (called the cover mold) is mounted on a fixed platen and aligned with the gooseneck channel. The second half of the die casting mold (called the ejector mold) is mounted on a movable platen that can slide along the tie rod.
The hydraulic clamping device drives the clamping rod, which pushes the pressure plate towards the cover die and applies enough pressure to keep it closed when the molten metal is injected. After the metal solidifies in the cavity, the clamping device releases the mold halves and at the same time, the ejection system pushes the casting out of the open cavity. The die casting mold can then be closed for the next injection.