【摘要】：隨著塑料產(chǎn)品在各個(gè)領(lǐng)域的廣泛應(yīng)用,人們對(duì)產(chǎn)品的質(zhì)量要求也不斷提升。傳統(tǒng)的依據(jù)經(jīng)驗(yàn)進(jìn)行注塑模具設(shè)計(jì)和工藝調(diào)試的方法,越來(lái)越不能滿足結(jié)構(gòu)復(fù)雜、質(zhì)量要求高的注塑件生產(chǎn)要求,CAE技術(shù)的應(yīng)用給注塑模具和工藝的開(kāi)發(fā)帶來(lái)了新的思路,同時(shí)能夠縮減產(chǎn)品開(kāi)發(fā)周期、節(jié)約成本及提高生產(chǎn)效率。本文以某款汽車門鎖(POM)為研究對(duì)象,運(yùn)用CAD設(shè)計(jì)及有限元數(shù)值模擬手段對(duì)注塑模進(jìn)行合理設(shè)計(jì),并采用數(shù)學(xué)優(yōu)化方法對(duì)汽車門鎖注塑工藝進(jìn)行優(yōu)化。本文主要研究?jī)?nèi)容如下:首先,介紹了車用塑料分類和性能、注塑成型技術(shù),分析了注塑成型中常見(jiàn)的缺陷及改善措施。利用UG軟件設(shè)計(jì)汽車門鎖產(chǎn)品,在模具設(shè)計(jì)過(guò)程中借助Moldflow模流分析軟件進(jìn)行注塑成型過(guò)程分析,預(yù)測(cè)各設(shè)計(jì)方案成型過(guò)程中可能存在的缺陷,進(jìn)而設(shè)計(jì)出合理的注塑模具結(jié)構(gòu)。本文選取模具溫度、熔體溫度、冷卻時(shí)間、保壓壓力與保壓時(shí)間這五種工藝參數(shù)為設(shè)計(jì)變量,以翹曲變形量和頂出時(shí)體積收縮率為優(yōu)化質(zhì)量目標(biāo),進(jìn)行Moldflow數(shù)值模擬的正交試驗(yàn)。對(duì)試驗(yàn)結(jié)果進(jìn)行極差和方差分析,預(yù)測(cè)出了變量對(duì)目標(biāo)的影響規(guī)律及顯著順序,同時(shí)分別得到翹曲變形量和頂出時(shí)體積收縮量分別較小的兩組工藝參數(shù)組合。其次,基于正交試驗(yàn)結(jié)果,將翹曲和收縮綜合成單一目標(biāo)來(lái)作為綜合成型質(zhì)量的評(píng)價(jià)指標(biāo),建立以上因素不同水平對(duì)這個(gè)單一目標(biāo)的灰色關(guān)聯(lián)度模型,進(jìn)行單一目標(biāo)尋優(yōu)�；疑P(guān)均值越大,則其對(duì)單一目標(biāo)的影響因子越大,產(chǎn)品的綜合質(zhì)量越好,最后得到最優(yōu)工藝參數(shù)組合。對(duì)這一組參數(shù)合進(jìn)行Moldflow驗(yàn)證,結(jié)果顯示:在塑件翹曲和收縮得到有效控制的前提下,綜合成型質(zhì)量得到了較好的提高,翹曲和收縮達(dá)到了兼顧改善的成效。最后,選取保壓壓力和熔體溫度這兩個(gè)對(duì)變形和收縮影響較大的因子作為優(yōu)化變量,仍以最大變形翹曲和最大頂出體積收縮率為優(yōu)化目標(biāo),利用二階響應(yīng)面建立變量和目標(biāo)之間的非線性映射關(guān)系,并將兩個(gè)目標(biāo)的響應(yīng)面等值線進(jìn)行疊加以尋找最優(yōu)區(qū)域,并得到了精確的最優(yōu)工藝參數(shù)組合(模具溫度60℃、熔體溫度180.5℃、冷卻時(shí)間16s、保壓壓力為注射壓力98.75%、保壓時(shí)間20s)。該組工藝組合的模擬成型結(jié)果比灰色關(guān)聯(lián)的效果更好。依據(jù)此工藝參數(shù)組合進(jìn)行模具調(diào)試,得到了綜合質(zhì)量較佳的汽車門鎖塑件,驗(yàn)證了響應(yīng)面優(yōu)化法的準(zhǔn)確高效性,并為注塑模具開(kāi)發(fā)和塑件質(zhì)量提高提供了新的途徑。
[Abstract]:With the wide application of plastic products in various fields, the quality requirements of products have been improved. The traditional methods of injection mold design and process debugging based on experience can not meet the requirements of injection molding parts with complicated structure and high quality. The application of CAE technology brings new ideas to the development of injection mould and technology. At the same time can reduce product development cycle, cost savings and improve production efficiency. In this paper, a certain automobile door lock (POM) is taken as the research object. The injection molding process is optimized by means of CAD design and finite element numerical simulation, and the mathematical optimization method is used to optimize the injection molding process of the door lock. The main contents of this paper are as follows: firstly, the classification and performance of automotive plastics, injection molding technology, common defects in injection molding and improvement measures are introduced. The automobile door lock product is designed by UG software, and the injection molding process is analyzed by Moldflow mold flow analysis software in the process of mold design. The possible defects in the molding process of each design scheme are predicted, and the reasonable injection mold structure is designed. In this paper, five process parameters, such as die temperature, melt temperature, cooling time, pressure holding pressure and pressure holding time, are selected as design variables, and Moldflow numerical simulation orthogonal experiments are carried out with warpage deformation and volume shrinkage at top out as the optimization quality target. By analyzing the range and variance of the test results, the influence law and significant order of the variables on the target are predicted. At the same time, the combination of two groups of process parameters, which have smaller warpage deformation and smaller volume shrinkage at the top, are obtained respectively. Secondly, based on the results of orthogonal test, warping and shrinkage are combined into a single target to evaluate the quality of the composite molding, and the grey relational degree model of the single target is established at different levels of the above factors, and the single objective optimization is carried out. The larger the grey mean value is, the greater the influence factor on the single target is, and the better the comprehensive quality of the product is. Finally, the optimal combination of process parameters is obtained. The results of Moldflow verification show that the comprehensive molding quality has been improved and the warpage and shrinkage have been improved with the effective control of the warping and shrinkage of the plastic parts. Finally, two factors, pressure holding pressure and melt temperature, which have great influence on deformation and shrinkage, are selected as the optimization variables, and the maximum warpage and the maximum ejection volume shrinkage are still taken as the optimization targets. The nonlinear mapping relationship between variables and targets is established by using the second-order response surface, and the response surface isolines of the two targets are superimposed to find the optimal region, and an accurate combination of the optimal process parameters (die temperature 60 鈩，

本文編號(hào)：2312650