Abstract: Aiming at the difficulty in mold design for the complex shape of plastic parts, we reported a design for the injection mold with one mold, one cavity and three plates. A two-layer parting mode and a 3-point gating system were adopted for the plastic parts. Aiming at the requirement for the mufti-feature and multi-purpose demolding of plastic parts, six slider core-pulling mechanisms and three inclined top mechanisms were designed to conduct the demolding action. In the slider core-pulling mechanism, the slider-driving mode in the slider mechanism was modified to the external spring-driving one, and the oblique core-pulling mechanism was modified to the horizontal slider driving tunnel slider oblique core-pulling mode. Such a design effectively reduced the excessive structural size requirements of the mechanism to the die, and therefore reduced the manufacturing cost and overcame the difficulties in processing and assembly. A new type of oblique-top mechanism with a front die was designed, in which a spring was used to drive the oblique-top rod to eject the plastic parts from the cavity. This design realized the side core pulling and demolding in the front die with the characteristics of bending hook and hole. The mechanisms designed by this work are simple and feasible for the injection mold, and their working reliability is high. Our design effectively simplifies the overall structure of the mold and makes the processing and manufacturing much easier.

Key words: parting, mechanism improvement, demolding, mold structure, injection