采用了一种新型的可调式转动导杆机构，来调整自动包装热合机横封室的瞬时线速度,使其与塑料袋膜的进给速度相一致。通过SolidEdge对曲柄组件进行了三维建模，并对该模型进行了精确质量与质心位置的分析，通过配重法改变了构件的结构，从而解决了机构动平衡问题。

The adjustment of instantaneous linear rate of the cross envelop room of automatic hot-seal packaging machine was carried out using a new adjustable rotating guide-bar mechanism to make it compliance with the feed rate of membrane. Three dimensional model of crank component was established, and quality and centroid of the model was analyzed by using SolidEdge. The structure of component was transformed by counter-weights method to solve dynamic balance problem of the mechanism.