The cavity design of the lower die of the automotive die-casting mold is a key engineering task, which directly affects the shape, size and quality of the final parts.

Part geometry considerations:

The cavity design of the lower mold first needs to consider the geometry of the final part. This includes the part's contours, internal and external surfaces, special structures such as grooves and protrusions. Using CAD software, designers can accurately draw the shape of the mold cavity to ensure it is consistent with the part design.

Mold cavity structure design:

The design of the mold cavity structure includes the finish, surface treatment and geometry of the inner wall. In order to ensure the quality of the surface of the parts, the cavity of the lower mold usually undergoes surface treatment such as polishing or electrolytic polishing to reduce surface defects and improve the finish. In addition, the geometry of the inner wall of the mold cavity needs to take into account factors such as the component structure, wall thickness, and eddy currents.

Cooling system design:

Similar to the upper mold, the lower mold also needs to be designed with an effective cooling system. The layout of the cooling channels needs to take into account the shape of the mold cavity to ensure that the cooling medium evenly covers the entire mold cavity surface. The cooling system helps maintain a stable temperature throughout the lower mold structure.

Diameter and location of cooling channels:

The diameter and location of the cooling channels need to be carefully designed according to the shape and requirements of the mold cavity. The choice of channel diameter directly affects the cooling effect, and the location of the channel needs to ensure that it can effectively cover the key areas that need cooling.

Surface cooling:

Similar to the upper mold, there may be areas with special structures on the cavity surface of the lower mold, which require special attention to the design of surface cooling. This may include part surfaces that require high surface quality, where finer temperature control can be achieved by increasing cooling channel density or using localized cooling.

Mold cavity surface coating:

To further improve the wear resistance of the mold cavity and reduce metal adhesion, a coating may be applied to the cavity surface of the lower mold. These coatings are usually carbide or ceramic materials that can improve the wear resistance of the mold cavity and extend the service life of the mold.

Considerations for mold cavity exhaust systems:

In mold cavity design, an exhaust system needs to be considered to eliminate bubbles or gases that may be generated when metal fills the mold cavity. Proper exhaust system design helps prevent pores on the surface of parts and ensures the quality of the final product.

Internal structure of mold cavity:

Some special parts may require special structures inside the mold cavity, such as sliders, ejection systems, etc. These structures need to be coordinated with the design of the entire mold cavity to ensure that the mold can produce complex part structures.