1. Importance and basic principles of parting surface design
The parting surface of die casting mold is the interface between the movable mold and the fixed mold. Its design directly affects the quality of the casting, the structural complexity of the mold, and the difficulty of demolding. Reasonable parting surface design should follow some basic principles. For example, to ensure that the casting can be smoothly removed from the mold, the parting surface should be selected at the largest cross-section of the casting so that the casting can remain on the movable mold or the fixed mold side after the mold is opened; at the same time, the parting surface should be as simple as possible to avoid complex curved surfaces or broken lines to reduce mold processing costs and manufacturing difficulties. For example, for simple cylindrical castings, a plane along the axis of the cylinder can be selected as the parting surface, so that the casting can be easily removed from the mold when the mold is opened.
2. Parting surface factors affecting demolding convenience
In actual design, there are many factors that affect the relationship between the parting surface and the demolding convenience of the casting. If the position of the parting surface is not selected properly, it may cause greater resistance when the casting is demolded. For example, when the parting surface is close to the thin-walled part of the casting, due to the relatively low strength of the thin-walled part, it is easy to deform or even break due to uneven force during the demolding process. In addition, the shape of the parting surface is also critical. If there are sharp corners or discontinuous steps on the parting surface, the casting will get stuck during demolding, increasing the difficulty of demolding. For example, in some castings with complex inner cavities, if the parting surface does not fit the shape of the inner cavity well, it may cause the inner cavity wall to be strained during demolding.
3. Optimization design strategy
In order to improve the convenience of demolding, a variety of parting surface optimization design strategies can be adopted. First, an inclined parting surface design can be adopted. For some castings with a certain taper or tilt feature, the parting surface is made at a certain angle to the demolding direction of the casting. By utilizing the shape characteristics of the casting itself, the casting can be smoothly ejected with the help of gravity or a smaller demolding force when opening the mold. Secondly, adopt a multi-parting surface design. For castings with complex shapes, by reasonably setting multiple parting surfaces, the demoulding process of the casting is decomposed into multiple steps, reducing the demoulding difficulty of each step. For example, in some castings with undercuts or side holes, the main part can be first ejected through one parting surface, and then the core of the undercut or side hole part can be ejected using another parting surface. Furthermore, design an appropriate demoulding slope at the die casting mold parting surface, generally between 0.5°-3°, and determine the specific value based on factors such as the material, shape and size of the casting. This can effectively reduce the friction between the casting and the mold and make demoulding smoother.
4. Simulation analysis and verification
After determining the optimization design of the parting surface, it is necessary to verify it with the help of computer simulation analysis software. By simulating the die casting process and demoulding process, you can intuitively observe the molding of the casting in the mold and the stress distribution and deformation during demoulding. According to the simulation results, the parting surface design is further adjusted and improved to ensure that in actual production, the design of the die casting mold parting surface can truly achieve smooth demolding of castings, improve production efficiency, reduce casting scrap rate, reduce production costs, and also extend the service life of the mold.
