How does Wheel Hub Differential Pressure Casting Mold control the pressure difference during casting?

Wheel Hub Differential Pressure Casting Mold plays a vital role in the production process of automobile wheel hubs. Its differential pressure casting technology uses pressure differences to optimize the fluidity of molten metal, thereby improving the quality and accuracy of castings. The following will be an in-depth discussion of how the hub differential pressure casting mold controls the pressure difference during the casting process to ensure the production of high-quality wheel hub castings.

Differential pressure casting is a casting process that uses the pressure difference between the inside and outside of the mold to push molten metal into the mold cavity. By precisely controlling the pressure inside the mold, differential pressure casting can significantly improve the fluidity and filling uniformity of metal and reduce casting defects compared to traditional gravity casting or low-pressure casting.

1. Control principle of pressure difference
The basis for controlling the pressure difference is mold design. The hub differential pressure casting mold generally consists of two parts: the fixed mold and the movable mold. The following factors need to be considered when designing:
Pressure control system: The mold is equipped with a pressure control system, including pressure sensors, regulating valves and pressure pumps. These systems are used to monitor and regulate the pressure within the mold in real time to ensure that the pressure difference remains within a preset range during the casting process.
Gate and vent design: The gate system and vent design of the mold are critical to pressure difference control. The gate system needs to be designed properly to ensure that the molten metal can flow into the mold smoothly, while the vents help discharge gas and bubbles in the mold to avoid affecting the stability of the pressure difference.

2. Injection of molten metal
High Pressure Injection: In the differential pressure casting process, molten metal is fed into the mold through a high-pressure pump. Injection pressure is usually set between 2 and 15 bar (bar), depending on the size and complexity of the wheel hub. High-pressure injection can push metal into the mold cavity evenly and improve the filling effect.
Pressure injection: During the injection process, the pressure inside the mold is higher than the external pressure. By adjusting the injection pressure and speed, the flow path of the metal within the mold can be controlled, optimizing the filling effect and reducing defects.

3. Real-time monitoring of pressure difference
In order to maintain the stability of the casting process, the pressure difference within the mold must be monitored and adjusted in real time:
Pressure sensor: A pressure sensor is installed inside the mold to monitor pressure changes in the mold in real time. These sensors provide precise data to help operators adjust pressure settings in a timely manner.
Automatic adjustment system: Modern differential pressure casting molds are equipped with automatic adjustment systems that automatically adjust the pressure within the mold based on sensor data. The system can dynamically adjust the pressure according to actual casting conditions to ensure a stable casting process.

4. Maintenance of pressure difference
Stability control: By accurately controlling the pressure difference between the inside and outside of the mold, the impact of pressure fluctuations on casting quality can be avoided. A stable pressure difference ensures that the metal fills the mold evenly and reduces defects such as pores and shrinkage cavities.
Pressure release: After the molten metal is injected, the pressure within the mold needs to be gradually released. The pressure relief process needs to be precisely controlled to ensure that excessive thermal stress or deformation does not occur during cooling of the casting.