The Relationship Between Lift Resistance Of Car Door Glass And Door Manufacturing Deviations

Door glass lifting system is one of the important part in the car door composition systems,providing some assurance for sealing and safety,but the failure rate of car door glass lifter system had a relatively high,seriously influence on the car entirety quality.The main performance: getting stuck in the lifting process;glass inclined in the X direction was in contact with the guide groove seal the bottom of strip;unstable lifting process,seriously would produce severe sharp noise.Since main contacting was between glass and seal in the lifting process,main causes of the problem: Excessive contact between glass and seal caused by unsuitable assembly variation would produce a greater lifting resistance.To solve these problems,the deviation of the actual assembly process and its generation mechanism is analyzed,and on this basis,seal compression characteristic was simulated with finite software while the mathematical model of the lifting resistance and the dimension deviation was solved and analyzed with MATLAB software,getting lifting resistance curves of different assembly variation about the glass guide groove,inside and outside of the door plank,and so on,and its impact was studied.This paper aims to provide a basis for designing each member assembly deviation of the door glass lifting system and improve the operation stability and life of the glass elevator system.The main contents of this paper are as follows:(1)The mechanical characteristics of the door glass was analyzed and The mathematical mechanical model of glass was constructed with the finite element method,obtaining friction of the door waist water cut seal and guide groove seal was the main lifting resistance and both assembly deviation impact was greater.While using finite element software compression characteristics of the door waist water cut seal and guide groove seal were analyzed.On this basis,the mathematical model is solved by MATLAB to obtain the variation characteristics of the forces and moments in the lifting process.(2)From the perspective of technology and assembly process,deviation formation mechanism of guide groove was analyzed,getting the assembly variation composition of the guide groove and its related factors.Using the finite element method and Monte Carlo simulation tolerance method,assembly dimension chain of the guide grooves,the guide groove seal and glass was analyzed to get the relationship between the relative dimension and the resistance,while the dimension tolerances of the chain was redesigned.The influence of Guide groove assembly deviations in the X,Y direction on the lifting resistance was studied,the glass and guide groove seal the bottom was non-contact in the X direction,maintaining 2mm tolerance in the assembly process could improve the assembly success rate and ensure the glass would operate stably;It got lifting resistance curve for deviation angle ? and offset point ?p curve in the Y direction.(3)From the perspective of technology the deviation formation mechanism of the inner and outer panels and glass was analyzed,getting the assembly deviation composition of door plank and its associated factors.The mathematical model of lifting resistance and dimension chain in different closed loop of glass and cut seal was solved with the finite element method to obtain lifting resistance characteristics curve for dimensional chain,and the lifting resistance variation of the actual deviation in the assembly process were compared and analyzed,the results show that: choosing inner or outer dimension as the closed loop,assembly variation within a certain range,the former requires strict quality control,less friction,better effect,less the frictional resistance fluctuation range caused by deviation variation;the latter could use easy deviation,but there was a certain frictional resistance fluctuation.(4)The real vehicle was experimented with a dynamic glass lifting force measuring device.The car's front and back doors deviation in the Y direction would be tested,obtaining lifting resistance curves at different deviation,and the result showed: right front door was not sensitive for flush variation,and for the right behind door lifting resistance is reduced as flush increasing.