Low pressure casting equipment

Low pressure casting (LPDC for short) is a casting method in which molten metal is injected into a mold cavity at low pressure. Compared to high-pressure casting, low-pressure casting requires a lower pressure, usually between 0.1 and 0.6 MPa. This method is usually used for casting large or complex shapes ofaluminumThe casting of magnesium alloys, magnesium alloys and other light metal alloys is characterized by better casting quality and higher production efficiency. The key to this process is the low pressure casting equipment, which consists of several systems and components that ensure that castings are produced efficiently and accurately.Low-pressure casting(low pressure casting) equipment is the production of aluminum alloy low pressure casting products, usually used in the production of bulk products manufacturing industry: such as aluminum alloy low pressure casting automotive wheel production, steering knuckle production, automotive gearboxes, safety and explosion-proof shells, automotive gear box production. TodayNingbo HexinExplain the components of low pressure casting equipment:

Main components of low pressure casting equipment

1. heating furnace
   • Heating furnaces are used to melt metal alloys and keep the temperature of the molten metal within the proper range to ensure good flow. Common heating furnaces include resistance furnaces, induction furnaces, and so on. The temperature control system in the melting furnace is very important because too high or too low a temperature will affect the quality and accuracy of the castings.
2. Low Pressure Injection Systems
   • Low-pressure injection system is the core component of low-pressure casting equipment, and its main function is to inject molten metal into the mold through low pressure. The system usually consists of gas compressor, cylinder, pressure regulating valve and so on. The low pressure generated by the gas compressor presses the metal into the mold through the injection pipe. The injection process must be precisely controlled to ensure that the metal flows evenly within the mold cavity to avoid porosity and casting defects.
3. molds
   • Low-pressure casting molds are generally made of steel or other highly wear-resistant materials, and their shape and design determine the appearance of the final casting. The inner cavity of the mold usually includes parts such as cooling system, exhaust system, inlet and gate. The quality and precision of the mold and the design of the cooling system directly affect the quality and productivity of the castings.
4. cooling system
   • During low-pressure casting, the metal inside the mold needs to be cooled quickly to solidify the shape. The cooling system consists of embedded cooling water pipes or other channels for the cooling medium. The cooling system must be properly designed to ensure uniform cooling of the mold to avoid warpage and thermal stress problems in the casting.
5. exhaust system
   • During the low pressure casting process, air or gas in the mold cavity needs to be vented to prevent porosity or casting defects. The exhaust system ensures that the gas can escape smoothly by designing an exhaust channel in the mold. The venting system is essential to ensure the compactness and surface quality of the casting.
6. Ejector system
   • Ejector systems are used to eject castings from the mold after they have cooled and cured. Ejector systems typically include ejector pins, pneumatic or hydraulic actuators. The system needs to work smoothly and reliably to prevent damage to the casting and to ensure smooth ejection from the mold.
7. control system
   • The control system of low pressure casting equipment is used for real-time monitoring of critical parameters such as temperature, pressure, time and other parameters during the casting process and making automatic adjustments. Modern low pressure casting equipment is usually equipped with computer numerical control (CNC) or PLC control system, which can improve production efficiency and ensure the stability of process parameters in each production cycle.

Working principle of low pressure casting equipment

The working principle of low-pressure casting equipment mainly includes the following steps:

1. Molten metal
   • The metal alloy is melted by means of a heating furnace and the molten metal is held at the right temperature for low pressure injection. The heating furnace will deliver the molten metal to the injection system ready to enter the mold.
2. injection process
   • During the injection process, the molten metal is pressed into the mold by means of a low-pressure gas, usually air or nitrogen. The pressure ranges from 0.1 to 0.6 MPa. By adjusting the amount of pressure, the speed and flow pattern of the metal into the mold is controlled to ensure that the molten metal evenly fills the mold cavity.
3. Curing and Cooling
   • Once the molten metal enters the mold, it cools and solidifies rapidly. The cooling system within the mold controls the cooling rate through cooling water lines or other cooling media to ensure that the casting has the desired dimensional accuracy and surface quality.
4. Ejector castings
   • After the casting has cooled and solidified, the ejector system ejects the casting from the mold. At this point, the casting has been molded and is ready for the post-processing stage, such as deburring and cleaning.
5. Cleaning and reprocessing
   • Low pressure castings usually require post-treatment steps such as deburring, polishing, and cleaning to improve the appearance and surface quality of the castings. Some castings may also require heat treatment to improve mechanical properties.

Advantages and disadvantages of low pressure casting equipment

vantage

1. High quality castings
   • Low-pressure casting can obtain good casting surface quality and high dimensional accuracy. Due to low-pressure injection, the metal flow is smoother, reducing the occurrence of defects such as porosity and slag entrapment, and the casting surface is smooth and precise.
2. Suitable for production of large size castings
   • Low-pressure casting is suitable for the production of large, complex shapes of aluminum alloys or other light metal alloys castings, especially in the need for higher strength and lighter weight parts are widely used.
3. Lower production costs
   • Compared with high-pressure casting, low-pressure casting equipment costs and mold manufacturing costs are relatively low, and because of the shorter production cycle, large-scale production can reduce the unit cost.
4. Better Metal Recycling
   • During low-pressure casting, the metal flow is relatively stable and the scrap recycling rate is high, saving raw materials.

drawbacks

Low-pressure casting is mainly applicable to light metal alloys such as aluminum alloys and magnesium alloys, and is less effective for metals with high melting points, such as iron and copper, so the choice of materials is somewhat limited.1. Machine:

Relatively slow production speed

Compared to high-pressure casting, low-pressure casting has a slower production rate and may not be able to meet the extremely high productivity requirements, especially when producing large castings with long lead times.

Higher equipment requirements

Although the equipment for low-pressure casting is relatively simple, the precision of the equipment is required to be high, especially in the injection pressure and temperature control, which requires a high-precision control system to ensure the quality of castings.

Limited applicable materials

Machine is one of the components of a low pressure casting machine. The machine is the platform that prevents the mold. Since the machine needs to place the molds, the material of the machine should usually choose a strong and slightly thicker steel to ensure the stable, safe and reliable operation of the equipment after the molds are placed.