Study On The Optimization Of Injection Molding Process And Die For Base Of Blower

Evaporator blower is an import part in bus air conditioning system. The plastic base of blower is one of the key parts. There are so many quality problems in the process of injection molding considering the complexity of the structure of the base, such as burns flash、buckling deformation、casting fin and so on. A alternating load will be produced by the high velocity of the motor which can lead the damage to the base of blower, which will cause a great economic loss to the corporations.This paper aims at improving the strength of the vulnerable position of evaporator blower’s base. Combing with physics experiments, UG NX(three-dimensional mapping software)and Autodesk Moldflow Insight(injection molding simulation software) have been employed to solve the failure problems during the functioning of base comprehensively. The contributions of this paper can be summarized as below:1)The mean reasons leading to the failure of the base have been found to be irrational structure designing, low strength of material and existing of vulnerable position’s weld line, through analyzing the structure of the base;2)The base’s vulnerable positions have been greatly strengthened by changing the structure of base with increasing the strengthening ribs and improving the connection ways of base’s fixed motor;3)This paper changes the molding material ABS to PP+GF30 which have better overall performance, which greatly improves the tensile strength 、 high temperature tolerance and anti-vibration of the entire base;4)The gating system of base has been changed from point gating to straight gating using CAE analysis technologies, which greatly decreases the weld lines of vulnerable positions during injection molding.5)Based on Autodesk Moldflow Insight analysis software, melt temperature, mold temperature, filling time, packing time and S/P switch percentage have been analyzed with taguchi experiments and finally find the optimal combination of parameters.6)Some physically experiments have been conducted on the optimized bases. The results indicated the average tensile strength increased about 2.5 times(from 24.4Mpa to 61.8Mpa). There are no more failure damages of bases after the factory’s mass production and application, proving this kind of problems have been solved.7)This paper solves some problems during the process of application of plastic products comprehensively with CAE numerical simulation technology, which shortens the time, improve production efficiency and economic benefits and has a big guidance to the production and application of injection molding in the production practice.