聚甲醛齿轮强度形成机理及工艺优化

Study on strength formation mechanism and process optimization of POM gear

以提高齿根弯曲强度为目标开展聚甲醛齿轮的力学性能测试,优化了齿轮强度计算方法,提高了弯曲强度计算结果的可靠性。对试验结果进行分析,得到了模具温度、熔体温度、保压压力、注射速度、冷却时间、保压速度对齿轮强度的影响程度及趋势,得出模具温度和熔体温度是影响聚甲醛齿轮强度的关键工艺参数,且模具温度的影响最显著,并对成型制品进行DSC测试,发现制品强度与结晶度密切相关,提高模具温度和熔体温度增强了制品的结晶度,也提高了制品的强度。

In order to improve the bending strength of tooth root,the mechanical properties of polyformaldehyde(POM)gear were tested,and the strength calculation method was optimized to improve the reliability of bending strength results.The influence degree and potential trend of mould temperature,melt temperature,packing pressure,injection speed,cooling time,packing speed on gear strength were obtained by analyzing the experimental results.The results showed that the mould temperature and melt temperature were the key process parameters affect the POM gear bending strength,and the influence of the mould temperature was more obvious.DSC tests of products showed that the strength of products closely relate to the crystallinity,and the increase of mould temperature and melt temperature led to the increases of products crystallinity,thus increasing the product strength.