1. Structural design of composite manhole cover: In addition to the requirements of the machinery and equipment itself and the requirements of machining technology, the design of the structure of the composite manhole cover should also meet the requirements of the casting process, which should facilitate the manufacture of models, core boxes and shapes;
2. The shape of the composite manhole cover should be simple to facilitate mold release, and the casting parting surface should be as flat as possible with the minimum number;
3. The inner cavity of the composite manhole cover should not require or use a core when casting. When a core is used, it should be convenient for its support, fixation and exhaust sand production, and sufficient process holes should be provided when necessary;
4. For the structure of the inner and outer sides of the composite manhole cover and the reinforcing ribs, a certain structural slope should be set in the direction of the ejection;
5. The boss part on the composite manhole cover and the body of the composite manhole cover should not differ too much. It is best to take several bosses at the same height and close to the same surface, and it is best to connect them as a whole.