【正文】
作和動(dòng)作測(cè)試,以確定模具設(shè)計(jì)是否符合要求;接著進(jìn)行(3) 新型模具定位功能確認(rèn),其中利用雷射干涉儀量測(cè)新型模具定位精度;(4) 使用”Moldex”模流分析軟體模擬模穴壓力感測(cè)器及利用田口方法找出成型參數(shù)最佳化。經(jīng)過雷射干涉儀量測(cè)的結(jié)果如表2為新型光纖接頭滑塊滑動(dòng)振動(dòng)精度量測(cè)之?dāng)?shù)據(jù), mrads,而反光鏡架設(shè)位置與芯模頂端距離25mm,利用公式55計(jì)算芯模頂端的偏移量: (5)其中,dcore_pin為芯模頂端的偏移量;為表2的平均角度差,如圖16所示因此證明新型光纖接頭模具能使滑塊較平順滑動(dòng)減少振動(dòng),芯模能以平順的運(yùn)動(dòng)抽出成品,減少芯模折損率。130176。四、結(jié)論由上述實(shí)驗(yàn)及模擬結(jié)果可得到以下結(jié)論:(1) 以FANUC精密射出成形機(jī)進(jìn)行模板變形量測(cè),設(shè)計(jì)精密模具時(shí),須將之考量在內(nèi)。公式1說明由各量測(cè)點(diǎn)量測(cè)所得的徑度轉(zhuǎn)成高壓鎖模後模板平行度變形曲線,由於此曲線包含模板間相對(duì)變形量及模板平行度,為縮小模板平行度以獲得模板較真實(shí)的相對(duì)變形量將模板變形度以簡(jiǎn)易法如公式2及一階曲線擬合公式計(jì)算: (2)其中,De:模板相對(duì)變形量,X:量測(cè)點(diǎn)位置。微射出成型如塑膠光纖接頭為載具的應(yīng)用技術(shù)瓶頸在於熔膠在流動(dòng)時(shí)因其黏彈性的特性,會(huì)造成模具芯模(core pin)微結(jié)構(gòu)的翹曲,因而形成孔洞的翹曲過大。在熔膠成型過程中,夾模單元必須提供足夠鎖模力以確保模具之閉合,防止塑料在高壓力的射出階段將模具撐開,導(dǎo)致成型不良的情形發(fā)生。再者,模板間閉合運(yùn)動(dòng)的滑動(dòng)公差設(shè)計(jì)會(huì)對(duì)具有靠迫特性的精密用模具造成尺寸偏移。綜合上述,以下針對(duì)射出機(jī)臺(tái)、模具設(shè)計(jì)與射出成型參數(shù)三大方向設(shè)計(jì)實(shí)驗(yàn)。在表1中,射出成型機(jī)及新型光纖接頭模具高壓鎖模後模板側(cè)方約有40μm及30μm左右的模板相對(duì)變形量,在模板各方向的靠迫瞬間,以射出機(jī)的側(cè)方模板靠迫瞬間的模板相對(duì)變形量約41μm最大,以上模板相對(duì)變形量的數(shù)值包含模板不平行程度及模板變形所造成的偏差量,針對(duì)傳統(tǒng)SC型光纖接頭模具設(shè)計(jì),芯模的作動(dòng)是以滑塊斜銷機(jī)構(gòu)來驅(qū)動(dòng),斜銷滑塊分別固定於模具之固定側(cè)與活動(dòng)側(cè),因此模板之相對(duì)變形勢(shì)必藉滑塊斜銷機(jī)構(gòu)傳遞至芯模上,此結(jié)果將在模具靠迫與高壓鎖模時(shí)對(duì)模具零件的變形及模具合模定位的精度產(chǎn)生影響。五、參考文獻(xiàn)[1] Boitout, F., . Thesis, CEMEF Sophia Antipolis, France (1997).[2] Leo, V. and Cuvelliez, C., “The Effect of the Packing Parameter, Gate Geometry, and Mold Elasticity on the Final Dimensions of a Molded Part,” Poly. Eng. Sci., v36, No15, pp. 1961 – 1971 (1996).[3] Hirosh, K., Hirosh, S., and Tatsuo, T., “Structural stiffness of injection mold and molding defect (discussion on reducing molding flash by improving structure of injection mold ),” Nippon Kikai Gakkai Ronbunshu C, v63, pp. 21442150 (1997).[4] 蔡浪富、洪水斌“肘節(jié)式射出機(jī)夾模單元設(shè)計(jì)分析”,機(jī)械工業(yè)雜誌, (1994)。六、圖表彙整表1. 模板於高壓鎖模後、低壓保護(hù)及高壓鎖模瞬間相對(duì)模板變形量項(xiàng)目簡(jiǎn)單法最小平方法最大值(μm)最大值(μm)射出成型機(jī)高壓鎖模後上方模板射出成型機(jī)低壓保護(hù)上方模板射出成型機(jī)高壓鎖模瞬間上方模板射出成型機(jī)高壓鎖模後側(cè)方模板射出成型機(jī)低壓保護(hù)側(cè)方模板射出成型機(jī)高壓鎖模瞬間側(cè)方模板光纖接頭模具高壓鎖模後上方模板光纖接頭模具低壓保護(hù)上方模板光纖接頭模具高壓鎖模瞬間上方模板光纖接頭模具高壓鎖模後側(cè)方模板光纖接頭模具低壓保護(hù)側(cè)方模板光纖接頭模具高壓鎖模瞬間側(cè)方模板表2. 新型光纖接頭滑塊滑動(dòng)振動(dòng)精度量測(cè)量測(cè)次數(shù)角度1(mrads)角度2(mrads)角度差(mrads)12345表3. 光纖接頭模擬實(shí)驗(yàn)射出參數(shù)設(shè)計(jì)表因子水準(zhǔn)水準(zhǔn)一水準(zhǔn)二水準(zhǔn)三保壓時(shí)間A1s熔膠溫度B330176。因此設(shè)計(jì)一可將射出機(jī)因素排除在外的新型模具,使活動(dòng)模壁位移所產(chǎn)生的頓點(diǎn)及震動(dòng)先完成後再進(jìn)行成品中心銷的插設(shè)或抽出動(dòng)作,避免微小的成品中心銷插設(shè)或抽出時(shí)造成斷裂,新型模具精密定位的模具動(dòng)作如下:(1) 模具開模時(shí),首先流道襯板與母模板分離,取出豎澆道如圖11至圖12。本實(shí)驗(yàn)針對(duì)30噸鎖模力全電式精密射出成型機(jī)(機(jī)型:FANUC ROBOSHOT α30iA)及模具進(jìn)行活動(dòng)、固定側(cè)模板於運(yùn)轉(zhuǎn)合模靠迫時(shí)模板平行度及變形的量測(cè)。對(duì)精密的微射出成型而言,模具的變形不但會(huì)使模穴在分模線產(chǎn)生間隙,亦會(huì)造成在高速充填時(shí)產(chǎn)生的毛邊現(xiàn)象直接影響尺寸。關(guān)鍵詞:微射出成型;精密定位機(jī)構(gòu);模具變形;製程參數(shù)最佳化;SC型塑膠光纖接頭AbstractThe conventional mold design and injection molding technique tends to apply for parts with large size and lowprecision dimension. Nowadays, molding parts with tiny dimensions and high accuracy are tremendously required. Thus, the positioning accuracy of mold plates movement and the control of their mold deformation are important to product quality. By employing the SCtyped plastic ferrules as the study vehicle, this research aims to design a new molding mechanism to achieve high positioning capacity when mold closing. The design concept is to eliminate the misalignment of mold closing caused by the deformation of the clamping unit. Moreover, the mercial software “Moldex” is applied to simulate the little deformation of tiny core caused by the drag force of melt polymer. By applying Taguchi method, the optimal parameter setting is decided. According to experimental result, the mold platens are affected by the molding machine’s vibration. Therefore taking this factor into account is necessary when optical fiber connector mold was designed. The measurement shows that this newtyped mold structure is more reliable in positioning than traditional one. Also, the injection rate and the melt’s temperature have great influence on core pin’s deformation.Keywords: micro injection molding, mold deformation, optimal process parameter, SCtyped plastic ferrules, mechanism of precision position.11 / 11格式說明:在摘要與全文之間插入「分節(jié)符號(hào)」與「分頁(yè)符號(hào)」參考:『插入分節(jié)與分頁(yè)符號(hào)』一、前言 內(nèi)文標(biāo)題格式說明:各段標(biāo)題字體規(guī)範(fàn)為:標(biāo)楷體11級(jí)大小,粗體,以小寫中文數(shù)字開頭段落間距:,參考:「段落設(shè)定」全文撰寫格式說明:一律以「雙欄式」撰寫全文參考:「設(shè)定雙欄」全文撰寫格式說明:一律以「雙欄式」撰寫全文參考:「設(shè)定雙欄」射出成型機(jī)係一種週期性量產(chǎn)塑膠成型品的機(jī)器,其主要機(jī)構(gòu)有塑化單元及夾模單元兩大部分。根據(jù)上述模具變形的原因,減少模具變形最直接的方法,可從模具設(shè)計(jì)改善,以往模具設(shè)計(jì)並無一定準(zhǔn)則可循,模具尺寸及其水路的設(shè)計(jì)皆採(cǎi)取經(jīng)驗(yàn)法則,為減少模具變形,Hirosh等人[3]藉由有限元素法進(jìn)行模具結(jié)構(gòu)及分模面的變形分析,有以下的結(jié)論:(1)稍微傾斜的分模面可減少分模面邊緣的變形;(2)公模板或承板在合模方向加厚有助於減少分模面的變形量。 模板平行度量測(cè)結(jié)果內(nèi)文使用方程式說明:內(nèi)文使用方程式,可用插入圖檔,或使用Microsoft Equation 參考:「插入方程式」根據(jù)量測(cè)數(shù)據(jù)曲線,取4個(gè)數(shù)據(jù)擷取點(diǎn),其中,數(shù)據(jù)擷取點(diǎn)1及數(shù)據(jù)擷取點(diǎn)2之差為高壓鎖模後於模板量測(cè)點(diǎn)量得的角度偏擺,數(shù)據(jù)擷取點(diǎn)1及數(shù)據(jù)擷取點(diǎn)3之差為模具進(jìn)入低壓保護(hù)階段、鎖模之前瞬間的角度偏擺,數(shù)據(jù)擷取點(diǎn)3及數(shù)據(jù)擷取點(diǎn)4之差為高壓鎖模瞬間模板得的角度偏擺,如圖9所示,第1區(qū)間為數(shù)據(jù)擷取至固定板和活動(dòng)板由閉模至完全開模時(shí),第2區(qū)間為固定板和活動(dòng)板開模停滯時(shí)間,第3區(qū)間為固定板和活動(dòng)板合模開始至即將靠迫時(shí)的歷程,第4區(qū)間為高壓鎖模固定板和活動(dòng)板靠迫瞬間的振動(dòng),第5區(qū)間為固定板和活動(dòng)板完全靠迫至數(shù)據(jù)擷取結(jié)束。在水準(zhǔn)值的採(cǎi)用方面,儘可能選取較大範(fàn)圍的水準(zhǔn)值,使最佳值能涵蓋在內(nèi),模具溫度,熔膠溫度,採(cǎi)用材料的建議值,其餘控制因子在不產(chǎn)生短射,焦痕等不良情況下選取水準(zhǔn)範(fàn)圍,控制因子水準(zhǔn)值如表3。)ρ(%)保壓時(shí)間A1熔膠溫度B2模具溫度C2射出壓力D2保壓壓力E2射出速率F2E(誤差)6eT(調(diào)和誤差)3T(總和)100圖1. 合模時(shí)模板不平行示意圖圖2. 鎖模力分佈不平均模具變形示意圖圖3. 鎖模力過大造成導(dǎo)柱彎曲時(shí)模板位移示意圖圖4. SC型光纖接頭尺寸、形狀及其規(guī)格光纖接頭模穴