汽车档位杆注塑模具冷却系统设计及优化

由于汽车档位杆属于薄壁中空零件,且采用的是收缩率较大的POM材料进行注塑成型,上、下模具和4个侧面抽芯方向的形状差异较大,因此,各个模具组件之间的温度梯度较大,在注塑成型过程中,经常会发生充填不足和缩水变形等工艺缺陷问题。针对塑件的结构特点设计了多层次的模具冷却系统,使复杂侧抽芯部件得到充分均衡的冷却,在细长抽芯内部设置螺旋隔片使细长抽芯零件也能够得到同步冷却,减少凝固结晶产生的应力,避免零件的翘曲变形和关键部位尺寸精度产生缺陷。应用模流分析技术对注塑过程中各层次的冷却回路工作情况进行数值分析,改进冷却系统结构,提高产品质量并缩短生产周期。

Design and Optimization of Cooling System for Injection Mould of Automobile Gear Rod

Because the automobile gear rod belongs to thin-walled hollow parts,and the injection moulding of POM material with higher shrinkage rate is adopted,the shape of the upper and lower moulds and the four side core-pulling directions are quite different,so the temperature gradient between each moulding component is large,and the filling shortage and shrinkage deformation often occur in the process of injection moulding.According to the structural characteristics of the automobile gear rod,a multi-level cooling system was designed to fully balance the cooling of complex side core-pulling parts.The spiral diaphragm set inside the slender core-pulling part can also be synchronously cooled to reduce the stress caused by solidification and crystallization,and to avoid warping deformation of the part and defects in the dimension accuracy of the key parts.Then,the numerical analysis of the cooling circuit at all levels of the injection process was carried out by using the technology of mould flow analysis.Finally,the cooling system structure was improved,the product quality was improved and the production cycle was shortened.