clamping mechanism of injection molding machine

ZHU Qiao-qiao1，ZHANG Ben-xi2

（1. Department Mechanical Engineering，Zhejiang University，Hangzhou 310027，China；

2. Zhejiang Sound machinery manufacture Co.，Ltd.，Hangzhou 310038，China）

Abstract：Aiming at the stress concentration phenomenon and the fracture problem in the practical work in the transitional structure of crosshead link，the varus type of double-toggle clamping mechanism was regarded to analyze and a design method with surface in the transitional structure was proposed. The dynamics simulation and the static finite element analysis were carried out on the crosshead link， the results showed that the stress concentration was obvious，the maximal stress exceeded the safety factor-1.5 of allowable stress and it

was the cause of the crosshead link fracture. Based on the relationship between radius and position of maximal stress in circle surface design method，a transitional curve equation was presented to construct the surface to reduce the maximum stress in the transitional structure. The comparison was carried on with the circle surface design method and wedge surface design method，the results indicate that the method verify the effectiveness of reducing the maximal stress of proposed design.

Key words：clamping mechanism；crosshead link；transitional structure；stress concentration；surface transition