Abstract:

In order to address a difficulty in the mold design of cylindrical plastic parts， a simplified injection mold with one mold， one cavity and two plates mold was designed to realize its automatic injection molding. In this mold， the horizontal layout was used to simplify the mold cavity parting， thus simplifying the overall structure of the mold. A hot runner pouring system was used to ensure the molding quality of the cavity. Three types of four mechanisms were used to demould the inner and outer walls of the plastic part. In these mechanisms， one was the single core-pulling mechanism of oil cylinder slider， one was the three core-pulling mechanisms of oil cylinder plus inclined guide pillar， and the other was the two-sided core pulling mechanism of a Half slider. A simple oil cylinder slider mechanism and a compound inner wall three times core?pulling mechanism were used to demould the inner wall of the plastic part. In the compound mechanism， the slider to pull the core of the inner wall was driven by the inclined guide column at first， and then the inner wall core drove three retracted inclined top core-pulling mechanisms to pull the core and demould the inner wall turndown table. Finally， the oil cylinder drove the slider and the molding part to pull the core completely from the plastic part. The wall tube was moved out to realize the complete demoulding of the plastic part. For the demoulding of the outer wall of the plastic part， a group of second core-pulling Haff slider mechanisms were used to demould the core. Through the optimizing the selection of the layout together with the innovative design of the mechanism， the overall structure of the mold is simplified， and its manufacturing cost is reduced.

Key words: hot runner, two-plate mold, three-time core pulling mechanism, two-time core pulling Haff slider, mold layout