基于Moldflow技术的塑料缸盖罩成型过程及模流数值分析

Numerical simulation analysis and molding process of plastic cylinder head cover based on moldflow analysis

为解决传统人工鉴定塑料缸盖罩瑕疵产品的方式效率低下、成本高,以及传统的直流道数学模型不适用于弯流道的问题。对塑料制品的成型原理及过程进行了阐述,基于Moldflow对塑料缸盖罩成型过程进行了模流分析,建立了熔体在弯流道中流动的理论模型,采用Moldflow在不同的注射速率条件下进行数值模拟。实验结果表明:采用的塑料缸盖罩的生产工艺有制品内、外温差大,冷却不均的问题;塑料熔体在弯流道内的流动速度、剪切速率以及温度都随着注射速率的增大而增大,熔体粘度随着注射速率的增大而降低;熔体在流经弯流道时外侧与内侧熔体的指标差值较直流道更大。

In order to solve the problems of low efficiency and high cost of traditional manual identification of defective products of plastic cylinder head cover,and that the traditional mathematical model of DC channel is not suitable for curved channel,the forming principle and process of plastic products are described,and the molding process of plastic cylinder head cover is analyzed based on Moldflow to establish the theoretical model of melt flow in bend runner.Moldflow is used for numerical simulation at different injection rates.The experimental results show that:the production process of plastic cylinder head cover adopted in this paper has the problems of large internal and external temperature difference and uneven cooling;the flow velocity,shear rate and temperature of plastic melt in the curved channel increase with the increase of injection rate;the melt viscosity decreases with the increase of injection rate;the flow velocity and viscosity of the melt close to the pipe wall are less than those in the middle of the flow channel.