Design of Three Plates Hot Runner Injection Mold with Multi-cavity and Twice Ejection for Toy Cover
Department of Mechanical Engineering, Sichuan Vocational and Technical College, Suining 629000, China
Abstract：According to the requirements of injection production of one mold with four cavities for toy shell plastic parts, a set of three plate injection mold including one mold with four cavities was designed. The compound runner combining hot runner with cold runner was used to overcome the problem that the runner was easy to block due to too long runner in multi cavity gating. According to the characteristics of toy shell, the mold cavity of the plastic part was divided and the molding parts were designed. The structure of the single cavity was simplified, and ensured one side core pulling mechanism can be set on each side of the four outer sides of single mold cavity. In order to ensure the automation production of mold, the general three-plate moldbase structure was modified, the hot-runner-plate was added to the fixed-mold, the second ejectior-plate was added to the moving-mold, and three auxiliary devices for the mold opening action were added to the moldbase, the ejection mechanism of moldbase was improved to twice ejection mechanism. The first demoulding of the plastic part on the core was completed by the co-ejection of round ejector, rectangular ejector and large slanted ejector, and the second demoulding of the plastic part on the large slanted ejector was completed by the continuous ejection of round ejector and the rectangular ejector, which ensures the non-destructive demoulding of the plastic part.
Keywords：multi-cavity-mold; design improvement; injection molding; structure design
Zhou Shurong. Design of three plates hot runner injection mold with multi-cavity and twice ejection for toy cover[J]. Engineering Plastics Application，2021，49(2)：103-109.