本文關(guān)鍵詞： 外角撐裝飾板 雙料重疊注射 制件翹曲 界面結(jié)合強度 澆口位置組合 工藝參數(shù)優(yōu)化　出處：《西華大學》2011年碩士論文　論文類型：學位論文

【摘要】：雙料重疊注射作為一種“模內(nèi)組裝”或“模內(nèi)焊裝”成型技術(shù),具有減少或取消二次裝配、縮短制件成型周期等諸多優(yōu)點。但由于設(shè)備、模具、成型工藝等因素的制約,使得雙料重疊注射技術(shù)的大規(guī)模應(yīng)用受到一定限制。因此,加強相關(guān)研究和開發(fā)顯得尤為重要。 轎車外角撐裝飾板通常位于轎車后側(cè)窗玻璃拐角處,由主體結(jié)構(gòu)和邊緣密封兩部分組成。該制件在雙料重疊注射成型中所面臨的典型質(zhì)量問題是翹曲量偏大和界面結(jié)合力欠佳。為解決此類質(zhì)量問題,傳統(tǒng)的做法往往是依靠實踐經(jīng)驗反復(fù)調(diào)試模具或注射參數(shù)來尋求最佳質(zhì)量控制的途徑。毫無疑問,這將導(dǎo)致生產(chǎn)成本的上升和能源的浪費。利用注射成型CAE技術(shù)不但可以預(yù)測外角撐裝飾板成型過程中原先只有通過試模才能暴露的成型缺陷,而且還可借助數(shù)值實驗結(jié)果,優(yōu)化雙料重疊注射工藝方案,提高成型產(chǎn)品質(zhì)量,同時降低生產(chǎn)成本。 本文在排除某外角撐裝飾板結(jié)構(gòu)工藝設(shè)計不合理和前后注射材料匹配不當?shù)纫蛩氐幕A(chǔ)上,借助Moldflow軟件,重點研究雙料重疊注射澆口位置組合與注射工藝參數(shù)對制件翹曲和界面結(jié)合的影響。 為此,本文首先擬定四種澆口位置組合方案,通過對這四種方案的實驗結(jié)果對比分析,找出成型外角撐制件的最佳澆口位置組合;然后基于最佳澆口位置組合安排正交試驗,研究前、后注射材料的熔體溫度、注射時間、保壓壓力、冷卻時間及模具溫度等工藝參數(shù)與制件翹曲和界面結(jié)合的關(guān)系;最后綜合成型質(zhì)量、設(shè)備噸位、成型周期等因素,選取最佳工藝方案并加以驗證。本文的研究結(jié)果表明: 1.澆口位置組合對外角撐裝飾板最終成型質(zhì)量影響較大。其中,成型制件密封邊上的澆口位置不同會影響后注射組份的熔體剪切速率和模腔內(nèi)的壓力分布,進而影響流動路徑上的熔體溫度分布和熔體密度分布。不均勻的溫度分布和密度分布會造成制件密封邊上不同區(qū)域的收縮不均,當由此引發(fā)的殘余應(yīng)力大于重疊注射材料的屈服強度時,密封邊便產(chǎn)生翹曲。此外,不均勻的熔體溫度分布還會影響后注射組份向與之接觸的基體表面?zhèn)鳠?進而影響基體側(cè)的局部熔化深度及熔化持續(xù)時間,最終影響基于界面分子相互穿插滲透的界面結(jié)合力。 2.不同的工藝參數(shù)對制件翹曲和界面結(jié)合兩個指標的影響程度不同。在給定的參數(shù)取值范圍內(nèi),先注射材料(ASA)的冷卻時間對兩個指標的影響均很弱;而重疊注射材料(TPV)的注射時間對兩個指標的影響卻均較強;ASA保壓壓力對制件高度方向的翹曲影響較大,對界面結(jié)合力的影響卻屬中等;而TPV注射溫度對界面結(jié)合強度的影響非常顯著,但對制件翹曲影響卻較小。 3.在ASA熔體溫度255℃、注射時間1.0s、保壓壓力取最大注射壓力的70%、冷卻時間15s和TPV熔體溫度200℃、注射時間0.7s、保壓壓力取最大注射壓力的70%、冷卻時間25s以及模具溫度70℃條件下成型外角撐裝飾板,其總體和高度方向的翹曲量均有不同程度的降低,且界面結(jié)合力也能得到較大改善。
[Abstract]:As a kind of " in - mold assembly " or " mold - in - mold welding " molding technology , double - material overlapping injection has many advantages such as reducing or eliminating secondary assembly , shortening the forming period of products , etc . However , the large - scale application of double - material overlapping injection technology is limited due to the factors such as equipment , mold , forming process and so on . Therefore , it is very important to strengthen the relevant research and development . in ord to solve that problem of quality control , the traditional practice often rely on the practice experience to repeatedly debug the mold or injection parameters to seek the best quality control . On the basis of eliminating the factors such as unreasonable design of the structural process of an outer corner brace and improper matching between the front and back injection materials , this paper focuses on the influence of the double - material overlapping injection gate position combination and the injection process parameters on the warpage and the interface of the product by Moldflow software . In this paper , four kinds of gate position combination schemes are proposed firstly , and the optimum gate position combination of the molded outer corner brace is found by comparing the experimental results of these four schemes . Then , the optimum technological scheme is selected and verified based on the optimum gate position combination . Finally , the optimum technological scheme is selected and verified by the factors such as temperature of melt , injection time , pressure maintaining pressure , cooling time and mould temperature . The results show that : in addition , that uneven temperature distribution and the density distribution can cause the contraction of different areas on the seal edge of the article to be nonuniform , and when the residual stress caused by the uneven temperature is larger than the yield strength of the overlapping injection material , the seal edge can cause warpage . 2 . The influence of different technological parameters on the warp and the interface of the products is different . The influence of the cooling time of the first injection material ( ASA ) on the two indexes is very weak in the range of the given parameter . The influence of the pressure of the ASA on the height direction of the product is relatively strong . The influence of the pressure of the ASA on the interfacial bonding strength is moderate ; however , the influence of the TPV injection temperature on the interface bonding strength is very significant , but the influence of the TPV injection temperature on the interfacial bonding strength is small . 3 . At the ASA melt temperature 255 鈩，

本文編號：1526335