When robot die castings and molds-industrial are demolded, deformation and surface damage are prone to occur due to the complex structure of the casting and uneven demolding force, which affects product quality and subsequent assembly. To prevent these problems, it is necessary to control the entire process from mold design, process parameter optimization to demolding operation.
Reasonable mold design is the basis for preventing die castings from being deformed and damaged during demolding. First of all, a reasonable demolding slope should be designed, and the demolding slope is generally controlled at 1° - 3° to ensure that the casting can be smoothly separated from the mold during demolding and reduce demolding resistance. For robot die castings and molds-industrial with complex shapes, a modular mold can be used to decompose the complex parts into multiple simple modules to reduce the difficulty of demolding. Secondly, the surface roughness of the mold has a significant impact on demolding. By fine processing, the surface roughness of the mold is controlled at Ra0.4 - Ra0.8μm, which can reduce the friction between the casting and the mold surface and avoid surface scratches. In addition, when setting the ejector mechanism at the key parts of the mold, the ejector pins need to be evenly distributed to avoid deformation of the die casting due to excessive local force.
Precise control of die-casting process parameters is crucial to the quality of demolding. If the die-casting temperature is too high, the casting will be insufficient in strength and easy to deform when demolding. Therefore, the die-casting temperature of aluminum alloy should be controlled at 620℃ - 680℃, and that of magnesium alloy should be controlled at 640℃ - 680℃. At the same time, the die-casting pressure and holding time should be adjusted reasonably. Excessive die-casting pressure will cause greater stress inside the casting, and too short holding time will cause shrinkage and looseness inside the casting, affecting the quality of demolding. Usually, the die-casting pressure is 40-80MPa, and the holding time is set according to the wall thickness of the casting. The holding time is about 1-2 seconds per millimeter of wall thickness. In addition, the mold preheating temperature also needs to be strictly controlled. Generally, the preheating temperature of aluminum alloy molds is 180℃ - 220℃, and that of magnesium alloy molds is 200℃ - 250℃. The appropriate mold temperature can ensure uniform cooling of the casting and reduce the risk of deformation.
The performance of the release agent directly affects the demolding effect. The mold release agent with good quality, high temperature resistance and good lubrication performance should be selected to ensure effective demolding without causing corrosion or residue on the surface of the die casting. When spraying the mold release agent, the spraying amount and uniformity should be controlled. Too much spraying will cause defects such as carbon deposits and pores on the surface of the casting, and too little spraying will not achieve a good demolding effect. The use of automatic spraying equipment can achieve uniform and appropriate spraying of the mold release agent by setting precise spraying parameters, reducing surface damage caused by improper use of the mold release agent.
Strict and standardized demolding operations can effectively avoid problems caused by human factors. When demolding, the ejection speed should not be too fast, generally controlled at 10-30mm/s, to avoid deformation of the casting due to large impact force caused by too fast speed. At the same time, ensure that the ejection mechanism runs smoothly to prevent the ejector from getting stuck or being out of sync, resulting in uneven force on the casting. After the casting is demolded, it should be placed on a dedicated cooling rack in time to avoid deformation due to improper placement. For large, thin-walled robot die castings and molds-industrial, auxiliary support devices such as elastic clamps can be used after demolding to provide necessary support during the cooling process of the casting to prevent deformation.
Regular maintenance of the mold is an important measure to ensure the quality of demolding. After the mold has been used for a period of time, problems such as wear and tear will occur on the surface, affecting the demolding effect. The mold needs to be polished and repaired in time. For severely worn parts, laser cladding and other technologies can be used for repair. At the same time, check the ejection mechanism, cooling system and other components of the mold to ensure their normal operation. Clean the mold regularly to remove impurities such as mold release agents and metal debris remaining on the surface to prevent these impurities from scratching the casting surface during demolding.
To prevent deformation and surface damage during demolding of robot die castings and molds-industrial, it is necessary to work together from mold design, process parameter control, mold release agent selection, operating process specifications to mold maintenance and maintenance. Only through refined management and technical optimization can the demolding quality of die castings be effectively improved and the production accuracy and quality of robot parts be guaranteed.
