工作燈后蓋注射模具設(shè)計【注塑模具】【一模兩腔】【側(cè)抽芯】【說明書+CAD】

工作燈后蓋注射模具設(shè)計【注塑模具】【一模兩腔】【側(cè)抽芯】【說明書+CAD】,注塑模具,一模兩腔,側(cè)抽芯,說明書+CAD,工作燈后蓋注射模具設(shè)計【注塑模具】【一模兩腔】【側(cè)抽芯】【說明書+CAD】,工作,燈后蓋,注射,模具設(shè)計,注塑,模具,說明書,仿單,cad 摘 要塑料是以樹脂為主要成分的高分子有機化合物,樹脂可分為天然樹脂和合成樹脂兩大類,塑料大多采用合成樹脂.塑料制件之所以能得到廣泛應(yīng)用,是由于它們本身具有的一系列特殊優(yōu)點決定的.塑料工業(yè)是新興的工業(yè),是隨著石油工業(yè)的發(fā)展應(yīng)運而生的,目前塑料制件幾乎已經(jīng)進入一切工業(yè)部門以及人民日常生活的各個領(lǐng)域.塑料工業(yè)又是一個飛速發(fā)展的工業(yè)領(lǐng)域.我國的香港與深圳等地區(qū),其模具工業(yè)主要是從事塑料模具的制造與塑料制件的生產(chǎn).在江蘇省、浙江省、上海市及其以南地區(qū)，尤其在浙江省從事塑料模具的制造與塑料制件的開發(fā)的個體企業(yè)也日益增多。本設(shè)計說明書對塑料模具設(shè)計的各種成型方法，成型材料的設(shè)計，成型，成型零件的加工工藝（主要有線切割，電火花加工，數(shù)控車床，加工中心），主要設(shè)計參數(shù)的計算，產(chǎn)品缺陷及其解決方法，模具總體結(jié)構(gòu)設(shè)計及零部件的設(shè)計較詳細的做了介紹。綜上所述，塑料成型工業(yè)在基礎(chǔ)工業(yè)中的地位和對國民經(jīng)濟的影響顯得日益重要。關(guān)鍵詞：模具結(jié)構(gòu)、澆注系統(tǒng)、加工工藝。 目錄第一章擬定模具結(jié)構(gòu)形- 2 -1.1確定型腔數(shù)量及排列形式- 2 -1.2 模具結(jié)構(gòu)形式的確定- 3 -第二章 注射機型號的確定- 3 -第三章 分型面位置的確定- 4 -第四章 澆注系統(tǒng)形式和澆口的設(shè)計- 5 -4.1澆注系統(tǒng)的基本要點- 5 -4.2 主流道的設(shè)計- 6 -4.3分流道的設(shè)計- 8 -4.4 澆口的設(shè)計- 10 -4.6排氣槽的設(shè)計- 11 -第五章 成型零件的結(jié)構(gòu)設(shè)計與加工工藝- 12 -5.1 成型零件的結(jié)構(gòu)設(shè)計- 12 -第六章 冷卻水道的設(shè)計- 12 -第七章 成型零件的加工工藝- 13 -7.1 成型特性- 13 -7.2 型腔的加工工藝- 13 -7.3 型腔、型芯加工前的準備。- 14 -第八章 結(jié)構(gòu)零部件的設(shè)計- 14 -第九章 脫模推出機構(gòu)的設(shè)計- 14 -第十章 模具的試模與修模- 15 -第十一章 模具的動作過程- 15 -致 謝- 17 -第一章擬定模具結(jié)構(gòu)形1.1確定型腔數(shù)量及排列形式 型腔的數(shù)量是由長方給定的，為“一出二”即一模兩型腔，他們已考慮了本產(chǎn)品的生產(chǎn)批量（大批量生產(chǎn)）和自己的注射機型號。因此我們設(shè)計的模具為多型腔的模具?？紤]到模具成型零件和抽芯結(jié)構(gòu)以及出模方式的設(shè)計，模具的型腔排列方式如下圖1.1所示：1.2 模具結(jié)構(gòu)形式的確定由于塑料外觀質(zhì)量可靠要求高，尺寸精度要求一般，且裝配精度要求高，因此我們設(shè)計的模具采用多型腔單分型面。第二章 注射機型號的確定一般工廠的塑膠部都擁有從小到大各種型號的注射機。中等型號的占大部分，小型號和大型號的占一小部分。所以我們不必過多的考慮注射機型號。具體的模具廠方提供的注射機型號和規(guī)格等參數(shù)如下：注射量：125g鎖模力：500T模板大?。?30X440拉桿內(nèi)間距：280X250開模距離：220模具定位孔距離：&55噴嘴球半徑：SR20螺桿轉(zhuǎn)速（r/min）:2030注射壓力/MPa:：80130根據(jù)塑件（ABS）面積尺寸計算鎖模力、注射量如下： 熔融塑料在分型面上的張開力，N-注射機的額定鎖模力，NA - 單個塑件在模具分型面上的投影面積。 - 澆注系統(tǒng)在模具分型面上的投影面積。p-塑料熔體對型腔的成型壓力，MPa，其大小一般是注射機的80%， ABS密度=1.02g/A=2282+276=264=2872-3.14=2016-33=1983=P(nA+)=(64-104)(2264+1983)=160.704-261.144KN450KNV=807228-766828+(76-6.5) 682+203+222=161280-144704+10268+68=26912經(jīng)過驗算，此注射機適用。第三章 分型面位置的確定 如何確定分型面，需要考慮的因數(shù)比較復(fù)雜。由于分型面要受到塑件在模具中的成型位置，澆注系統(tǒng)設(shè)計、塑件的結(jié)構(gòu)工藝性及精度。塑件位置形狀以及推出方式、模具的制造、排氣、操作工藝等多種因素的影響，因此在選擇分型面時應(yīng)綜合分析比較，從幾種方案中優(yōu)先選出較為合理的方案。選擇分型面時一般應(yīng)遵循以下幾個原則：1）分型面應(yīng)選在塑件外形最大輪廓處 2）便于塑件順利脫模，盡量使塑件開模時留在動模一邊。 3）保證塑件的精度要求。 4）滿足塑件的外觀質(zhì)量要求 5）便于模具加工制造。 6）對成型面積的影響。 7）對排氣效果的影響。 8）對側(cè)向抽芯的影響。 其中最重要的是第五和第八點。為了便于模具加工制造，應(yīng)盡量選擇平直分型面加工易于加工的分型面。把分型面放在A-A處有利于塑件的脫模。大大簡化了動模鑲塊、動模型心的加工，由于塑件收縮會包在動模型芯上和移模架的運動沖擊，制品便可自動脫落或手動取出。綜合考慮以上各方面因素決定分型面位置如圖3.1所示：.第四章 澆注系統(tǒng)形式和澆口的設(shè)計4.1澆注系統(tǒng)的基本要點 澆注系統(tǒng)的作用是將塑料熔體順利的充滿到行腔各處，以便獲得外型輪廓清晰，內(nèi)在質(zhì)量優(yōu)良的塑件。因此要求沖模速度快而有序，壓力損失小，熱量散失少排氣條件好，澆注系統(tǒng)凝料易于與塑件分離或切除，且在鑄件上留下澆口痕跡小。在設(shè)計澆注系統(tǒng)時，首先選擇澆口位置的選擇恰當與否，將直接關(guān)系到鑄件的成型質(zhì)量及注射過程是否能順利進行。流道及澆口位置的選擇應(yīng)遵循以下原則：1） 設(shè)計澆注系統(tǒng)時，流道應(yīng)盡量少彎折，表面粗糙度為m-1.6m2） 應(yīng)考慮到模具是一模一腔還是一模多腔，澆注系統(tǒng)應(yīng)按型腔的布局設(shè)計，盡量與模具中心線對稱。3） 單型腔塑件投影面積較大時，在設(shè)計澆注系統(tǒng)時，應(yīng)避免在模具的單面開設(shè)澆口，不然會造成注射時模具受力不均。4） 設(shè)計澆注系統(tǒng)時，應(yīng)考慮去除澆口方便，修正澆口時在塑件上不留痕跡。5） 一腔多模時，應(yīng)防止將大小懸殊的的塑件放在同一模具內(nèi)。6） 在設(shè)計澆口時避免塑件熔體填充過程中不致產(chǎn)生塑料熔體渦流、紊流現(xiàn)象，使型腔內(nèi)的氣體順利排出模外。7） 在滿足成型排氣良好的前提下，要選擇最短的流程，這樣可以縮短填充時間8） 在設(shè)計澆口時，避免塑料熔體直接沖擊小直徑型芯及嵌件，以免產(chǎn)生彎曲、折斷或異位。9） 在成批生產(chǎn)塑件時，在保證產(chǎn)品質(zhì)量的前提下，要縮短冷卻時間及成型周期。10） 若是主流道型澆口，因主流道處有收縮現(xiàn)象，若塑件在這個部位要求精度較高時，主流道應(yīng)留有加工余量或修正余量。11） 澆口的位置應(yīng)保證塑料熔體流入型腔，即對著型腔中寬暢、厚壁部位。12） 盡量避免使塑件產(chǎn)生熔斷痕，或使其熔斷痕產(chǎn)生在塑件不重要的部位。 4.2 主流道的設(shè)計4.2.1主流道的尺寸 主流道是一端與注射機噴嘴相接觸另一端與分流道相連的一段帶有錐度的流動通道。主流道錐度為2-6，小端前面是球面，其深度為3-5mm先端直徑比注射機直徑大0.5-1mm，因此要求主流道球面半徑比噴嘴球面大1-2 mm流道的表面粗糙度Ra8.4.2.2主流道襯套的形式主流道小端入口與注射機噴嘴反復(fù)接觸，屬易損壞，對材料要求較嚴，因而模具主流道部分常設(shè)計成可拆卸更換的主流道襯套形式（俗稱澆口套）以便有效的選用優(yōu)質(zhì)鋼材單獨進行加工和熱處理。澆口套都是標準件，只需要去買就行了。常用澆口套分為有托澆口套和無托澆口套兩種，下圖為前者，有托澆口套用于裝配定位圈。澆口套的規(guī)格有12、16、20，等幾種。由于注射機的噴嘴半徑為10，所以澆口套為R=10。如下圖4.1所示為澆口套的剖面圖：圖4.1澆口套剖面圖4.2.3主流道襯套的固定因為采用的有臺階的澆口套；所以用定位圈配合后固定，在模具的面板上。定位定位圈是標準件，外徑為55mm，內(nèi)徑為20 mm，具體固定的形式如下圖4.2所示：4.3分流道的設(shè)計在多型腔或單型腔多澆口（塑件尺寸大）時應(yīng)設(shè)置分流道，分流道是指主流道末端與澆口之間塑料溶體的流動通道。它是澆注系統(tǒng)中熔融狀態(tài)的塑料由主流道流入型腔前，通過截面積的變化及流向變換以獲得平穩(wěn)流態(tài)的過渡段，因此分流道設(shè)計應(yīng)滿足良好的壓力傳遞和保持理想的填充狀態(tài)并在流動的過程中壓力損失盡可能小，能將塑料溶體均勻的分配到各個型腔。1）主流道是圖（4.4）中定模下水平的流道為了便于加工幾凝料脫模，分流道大多設(shè)置在分型面上，分流道截面形狀一般為圓形及矩形等，工程設(shè)計中常采用梯形截面加工工藝好，且塑料熔體的熱量散失流動阻力均不大，一般采用以下經(jīng)驗公式可卻其截面尺寸：B=0.264 式（1）H=B 式（2）式中B-梯形大底邊的寬度（mm）M-塑件的重量（g）L-分流道的長度（mm）H-梯形的高度（mm）該式的選用范圍為塑件壁厚在3.2 mm以上，塑件質(zhì)量小于200g且計算結(jié)果應(yīng)在3.29.5 mm范圍內(nèi)才合理。本多用工具燈后蓋的體積為26912 mm，質(zhì)量大約為28 g，分流道的長度預(yù)設(shè)計成40 mm且有2個型腔，所以B=0.2654=7.06 取B為8mmH=5 取H為5mm梯形小底邊寬度取6MM，其側(cè)邊與垂直與分型面的方向約10，另外由于使用了定模板（即我們所說的定模和中間再加的一塊板，分流道必須做成梯形截面，便于分流道凝料脫模。實際加工時，常用兩種截面尺寸的梯形流道，一種大型號，一種小型號。如下圖4.3所示：（2）分流道的表面粗糙度由于分流道中與模具接觸的外層塑料迅速冷卻，只有中心部位的塑料溶體的流動狀態(tài)較為理想，因而分流道的內(nèi)表層粗糙度Ra并不要求很低，一般取1.6左右即可這樣表面稍不光滑，有助于塑料熔體的外層皮層堅固，從而與中心部位的熔體之間產(chǎn)生一定的速度差，以保證熔體流動時具有適宜的剪切速率和剪切熱。實際加工時，用銑床銑出流道后，少為省一下模，省掉加工紋理就行了。（拋光：制造模具的一道很重要的工序，一般配備了專業(yè)的拋光工，即用打磨機，砂紙，油石等打磨工具將模具型腔表面拋光，磨亮，降低型腔表面粗糙度。）3）分流道的布局形式分流道在分型面上的布置與前面所述型腔排列密切相關(guān)，有多種不同的布置形式，但應(yīng)遵循兩方面原則：即一方面排列緊湊、縮小模具版面尺寸：另一方面流程盡量短、鎖模力求平衡。本模具的流道布置形式采用平衡式，如圖4.4所示：4.4 澆口的設(shè)計澆口亦稱進料口，是連接分流道與行腔的通道，除直接澆口外，它是澆注系統(tǒng)中截面最小部分，但卻是澆注系統(tǒng)的關(guān)鍵部分，澆口的位置、形狀及尺寸對塑件性能和質(zhì)量的影響很大。4.4.1 澆口的選擇澆口可分為限制性和非限制性澆口兩種。我們采用限制性澆口。限制性澆口一方面通過截面積的變化，使分流道輸送來的塑料熔體的流速產(chǎn)生加速度，提高剪切速率，使其變成為理想的流動狀態(tài)，迅速面均衡地充滿型腔，另一方面改善塑料溶體進入時的流動特性，調(diào)節(jié)澆口尺寸，可使多型腔防止塑料熔體倒流，并便于澆口凝料分離的作用。從圖（4.4）中可看成，我們采用的是側(cè)澆口又稱邊緣澆口，國外稱為標準澆口。側(cè)澆口一般開設(shè)在分型面上，塑料熔體于型腔的側(cè)面充模，其形狀多為矩形（扁槽），改變澆口的寬度與厚度可以調(diào)節(jié)熔體的剪切速率及澆口凍結(jié)時間。這類澆口的可以根據(jù)塑件的形狀特性選擇其位置，加工和修正方便，因此它是應(yīng)用較廣泛的一種澆口形式，普通用于中小型塑件的多型腔模具，且對各種塑料的成型適應(yīng)性強，由于澆口截面小，減少了澆注系統(tǒng)塑料的消耗量，同時去除澆口容易，且不留明顯痕跡，但這種澆口成型的塑料往往有熔接痕存在，且注射壓力損失較大。對型腔塑件排氣不利。4.5澆注系統(tǒng)的平衡對于中小型塑件的注射模具以廣泛使用一模多型腔的形式，設(shè)計應(yīng)盡量保證所有的型腔同時得到均一的充填和成型。一般在塑件形狀及模具結(jié)構(gòu)允許的情況下應(yīng)將從主流道各個型腔的分流道設(shè)計成長值粗等。形狀及截面尺寸相同（型腔布局為平衡式）的形式，否則就需要通過調(diào)節(jié)澆口尺寸使各澆口的流量及成型工藝條件達到一致，這就是澆注系統(tǒng)的平衡。顯然我們設(shè)計的模具是平衡的，即從主流道到各個型腔的分流道的長度相等，形狀及幾截面尺寸相同。4.6排氣槽的設(shè)計選擇排氣槽的位置是很重要的，一般在塑料溶體填充型腔的同時，必須把氣體排出模具外。否則空氣被壓縮而產(chǎn)生高溫，引起塑體局部炭化燒焦，或使塑件產(chǎn)生氣泡，或使溶接線強度降低引起缺陷。尤其對于精密，大型模具，開設(shè)合理的排氣槽顯得更加重要。開設(shè)排氣槽應(yīng)注意以下幾點：1） 根據(jù)進料口的位置，排氣槽應(yīng)開設(shè)在型腔最后充滿的地方。2） 盡量把排氣槽開設(shè)在模具的分型面上。3） 對于流速較小的塑件，可利用模具的分型面及零件配合的間隙進行排氣4） 排氣槽的尺寸，要視塑料種類通常為0.01-0.035） 當型腔最后充填部位不在分型面上，其附近又無可供排氣的推桿或可活動的型芯時，可在型腔相應(yīng)部位鑲嵌經(jīng)燒結(jié)的金屬塊（多孔合金塊）以供排氣排氣槽的位置及深度可先經(jīng)試模后決定。小型制品的排氣量不大，如果排氣點正好在分型面的微小間隙排氣，本套模具可不必再開設(shè)專門的排氣槽，即可利用模具的分型面之間的間隙自然排氣。第五章 成型零件的結(jié)構(gòu)設(shè)計與加工工藝5.1 成型零件的結(jié)構(gòu)設(shè)計模具中決定塑料幾何形狀和尺寸的零件稱為成型零件，包括凹模、型芯、鑲塊、成型桿和成型環(huán)等。成型零件工作時，直接與塑料接觸，塑料溶體的高壓、料流的沖擠脫模時塑件間還發(fā)生摩擦。因此成型零件要求有真正的幾何形狀，較高的尺寸精度和較底的表面粗糙度，此外，成型零件還要求結(jié)構(gòu)合理、較高的強度、剛度及較好的耐磨性能。設(shè)計成型時應(yīng)根據(jù)塑件的特性和塑性的結(jié)構(gòu)使用要求，確定型腔的總體結(jié)構(gòu)，選擇分型面和澆口位置，確定脫膜方式、排氣部位等，然后根據(jù)成型零件的加工、熱處理、裝配等要求進行成型零件結(jié)構(gòu)設(shè)計，計算成型零件的工作尺寸對關(guān)鍵的成型零件進行強度和剛度校核。本套模具的成型零件包括型腔、兩個成型頂桿，兩個鑲塊由前面分析分型面的確定可知，成型零件總體上可分為型芯，即圖（3.1）中A-A分型面以上的部分。形成塑件外表面是型腔，鑲塊，在鑲塊上有一個小型銷，來形成鑄件的孔。一般成型零件工作尺寸制造公差值1/3-1/4或取IT7-IT8級作為制造公差，具體成型零件制造公差確定，參考塑料成型工藝與模具設(shè)計第145頁，如果需要可參考塑料成型工藝與模具設(shè)計第144頁-146頁所寫的公式。型腔尺寸的計算此塑件材料為（ABS），收縮率為0.4-0.7%此塑件精度等級選用5級平均收縮率第六章 冷卻水道的設(shè)計采用冷水調(diào)節(jié)模溫時，大氣中水分易凝聚在模具型腔的表壁，影響塑件的表面質(zhì)量。冷卻回路的設(shè)計應(yīng)做到回路系統(tǒng)內(nèi)流動的介質(zhì)能充分吸收成型零件所傳導(dǎo)的熱量，使模具成型表面的溫度穩(wěn)定的保持在所需的溫度范圍內(nèi)，并且要做到是冷卻介質(zhì)在回路系統(tǒng)內(nèi)流動暢通，無滯留部位。對于小型薄壁零件，且成型工藝要求模溫不大高時，可以不設(shè)置冷卻裝置而靠自然冷卻，本模具不屬于該類型所以采用冷卻裝。第七章 成型零件的加工工藝成型零件結(jié)構(gòu)設(shè)計完后，就要開始零件的下材料加工制作等，由于此塑件燈蓋的主要材料ABS，它具有良好耐化學(xué)腐蝕及表面硬度，丁二烯使ABS堅韌，苯乙烯使它有良好的加工性和深色性能。7.1 成型特性1.結(jié)晶性塑料，熔點較高，熔融溫度范圍寬，熱溶形溫度為93左右，且耐氣候性差，在紫外線作用下易變硬發(fā)脆。2.ABS無毒，無味呈微黃色，成型的塑料有較好的光澤，密度1.02-1.05g/3.ABS有良好的機械強度和一定的耐磨行，耐寒性，耐水性，化學(xué)穩(wěn)定性和電氣性能。4.水、無機鹽、堿和酸類對ABS無影響，但對醋、氯代烴中會溶解或形成乳化液，ABS不溶于大部分醇類溶劑，但與烴長期接觸會軟化融脹。5.ABS塑料表面冰醋酸、植物油等化學(xué)藥物的侵蝕會引起應(yīng)力開裂。ABS有一定的硬度和尺寸穩(wěn)定性，易于成型加工，經(jīng)過調(diào)色可配成任何顏色。6.ABS在升溫時黏度增高，所以成型壓力高，故塑件上的脫模斜度易稍大。7.ABS易吸水，成型加工前應(yīng)進行干燥處理。8.在正常成型條件下，壁厚熔料溫度時對收縮率影響極小。用途：ABS在機械工業(yè)上用來制造齒輪、軸承、把手、管道、電機、儀表殼、儀表盤、水筒外殼、蓄電磁槽、冷藏庫和冰箱襯里等。7.2 型腔的加工工藝型腔的加工多數(shù)用點火花，因為點火花機有電腦控制，故它的精度高，用點火花加工型腔需要用電板，電板材料由銅做成，我們需要兩個電極一個用于粗加工，一個用于精加工。1. 型芯的加工工藝型芯的加工可選擇在書控車床加工或加工中心。2. 鑲塊的加工工藝可選擇數(shù)控機床加工7.3 型腔、型芯加工前的準備。定模型芯為70*70*80的長方體、動模型芯為310*250*25的長方體。材料買來之后要開料。開料加工后的尺仍需要流0.2MM余量，因為材料熱處理后有少量變形，開料時，在銑床上銑掉材料的表層，先到立式銑床銑出外形，再到平面磨床磨光。型芯，鑲塊與塑料直接接觸，塑料的材料為ABS，所以要求鑲塊與型芯，材料各種性能要求都相當好，而且ABS具有一定的耐腐蝕性。第八章 結(jié)構(gòu)零部件的設(shè)計結(jié)構(gòu)零部件盡量采用標準或廠里有的，這樣即省時又省力。第九章 脫模推出機構(gòu)的設(shè)計 制造推出（頂出）是注射成型過程中的最后一個環(huán)節(jié)，推出質(zhì)量的好壞，將最后決定制品的質(zhì)量。本模具的推出機構(gòu)比較特別，他的脫模機構(gòu)是定模一側(cè)，此結(jié)構(gòu)設(shè)計簡單，模具的生產(chǎn)周期短。他不需要注射機上有推出裝置，脫模后產(chǎn)品上無頂桿的痕跡，產(chǎn)品外行美觀.經(jīng)濟性能好。第十章 模具的試模與修模 試模中所獲得的樣件對模具整體質(zhì)量的一個全面反映，以檢驗樣件修正和驗收模具，是塑料模具這種特殊產(chǎn)品的特殊性。首先，在初次試模中我們最常遇到的問題是根本得不到完整的樣件，常因塑件被黏附于模腔內(nèi)，或型芯上，甚至因流道粘著制品被損壞，這是試模首先應(yīng)當解決的問題。第十一章 模具的動作過程模具合模時，而后注入塑料，塑件成型后，開模時，動模在注塑機的作用下向后移動，此時由于本產(chǎn)品的特點（產(chǎn)品內(nèi)部有個內(nèi)搭扣）使其固定在定模型芯上，當注塑機繼續(xù)向后移動，在限位板的作用下帶動卸料板使其產(chǎn)品硬性從定模型芯上脫落。 參考文獻（1） 屈華昌塑料成型工藝與模具設(shè)計 機械工業(yè)出版社 1995（2） 蔣繼宏 王效岳注塑模具典型結(jié)構(gòu)100例 中國輕工業(yè)出版社 2000（3） 李德群 唐志玉中國模具設(shè)計大典 江西科學(xué)技術(shù)出版社 2003（4） 許發(fā)樾實用模具設(shè)計與制造手冊 機械工業(yè)出版社 2000（5） 吳宗澤機械零件設(shè)計手冊 機械工業(yè)出版社 2003（6） 黃毅宏模具制造工藝 機械工業(yè)出版社 1996（7） 鄒繼強塑料制品及其成型模具設(shè)計 清華大學(xué) 2005 結(jié) 論 經(jīng)歷了幾周的畢業(yè)課程設(shè)計即將結(jié)束在此希望各位老師對我的設(shè)計過程做最后的審閱與檢查。 在這次的畢業(yè)課程設(shè)計中我通過對有關(guān)模具設(shè)計方面的資料的參考及查閱，請教XX老師等參與輔導(dǎo)我們畢業(yè)設(shè)計的老師有關(guān)模具方面的問題，特別是在采用標準零件時所遇到的困擾。老師們都能給予我們答案。使我在短短的時間內(nèi)，對模具有了一定的了解。讓我對塑料模具設(shè)計的各種成型材料的設(shè)計，成型零件的加工工藝（主要有線切割、電火花、加工、數(shù)控車床、加工中心），主要設(shè)計參數(shù)的計算，產(chǎn)品缺陷及其解決方法，模具總體結(jié)構(gòu)設(shè)計及零部件的設(shè)計有了進一步的了解及掌握。在設(shè)計過程過程中，起初的設(shè)計中也不順利，但通過查閱有關(guān)書籍 致 謝在這次畢業(yè)設(shè)計中得到了XX老師等參與輔導(dǎo)我們畢業(yè)設(shè)計的老師及同學(xué)的指點和幫助，特別是老師們耐心講解的指導(dǎo)，使我在這次課程設(shè)計中受益非淺。在此，我要對關(guān)心及指導(dǎo)我的老師們和幫助過我的同學(xué)表示衷心的感謝。 - 17 - 編號： 畢業(yè)設(shè)計(論文)外文翻譯（原文）院 （系）： 國防生學(xué)院 專 業(yè)：機械設(shè)計制造及其自動化 學(xué)生姓名： 蔡秀濱 學(xué) 號： 1001020105 指導(dǎo)教師單位： 機電工程學(xué)院 姓 名： 郭中玲 職 稱： 高級工程師 2014年 3 月 9 日Contents1.The Injection Molding12.Automated surface nishing of plastic injection mold steel with spherical grinding and ball burnishing processes14第 22 頁 共 23 頁 桂林電子科技大學(xué)畢業(yè)（論文）報告專用紙 The Injection Molding Alp Tekin Ergenc , Deniz Ozde KocaYildiz Tecnical University, Mechanical Engineering Department, IC Engines Laboratory, TurkeyThe Introduction of MoldsThe mold is at the core of a plastic manufacturing process because its cavity gives a part its shape. This makes the mold at least as critical-and many cases more so-for the quality of the end product as, for example, the plasticiting unit or other components of the processing equipment.Mold MaterialDepending on the processing parameters for the various processing methods as well as the length of the production run, the number of finished products to be produced, molds for plastics processing must satisfy a great variety of requirements. It is therefore not surprising that molds can be made from a very broad spectrum of materials, including-from a technical standpoint-such exotic materials as paper matched and plaster. However, because most processes require high pressures, often combined with high temperatures, metals still represent by far the most important material group, with steel being the predominant metal. It is interesting in this regard that, in many cases, the selection of the mold material is not only a question of material properties and an optimum price-to-performance ratio but also that the methods used to produce the mold, and thus the entire design, can be influenced.A typical example can be seen in the choice between cast metal molds, with their very different cooling systems, compared to machined molds. In addition, the production technique can also have an effect; for instance, it is often reported that, for the sake of simplicity, a prototype mold is frequently machined from solid stock with the aid of the latest technology such as computer-aided (CAD) and computer-integrated manufacturing (CIMS). In contrast to the previously used methods based on the use of patterns, the use of CAD and CAM often represents the more economical solution today, not only because this production capability is available pin-house but also because with any other technique an order would have to be placed with an outside supplier.Overall, although high-grade materials are often used, as a rule standard materials are used in mold making. New, state-of-the art (high-performance) materials, such as ceramics, for instance, are almost completely absent. This may be related to the fact that their desirable characteristics, such as constant properties up to very high temperatures, are not required on molds, whereas their negative characteristics, e. g. low tensile strength and poor thermal conductivity, have a clearly related to ceramics, such as sintered material, is found in mild making only to a limited degree. This refers less to the modern materials and components produced by powder metallurgy, and possibly by hot isocratic pressing, than to sintered metals in the sense of porous, air-permeable materials.Removal of air from the cavity of a mold is necessary with many different processing methods, and it has been proposed many times that this can be accomplished using porous metallic materials. The advantages over specially fabricated venting devices, particularly in areas where melt flow fronts meet, I, e, at weld lines, are as obvious as the potential problem areas: on one hand, preventing the texture of such surfaces from becoming visible on the finished product, and on the other hand, preventing the microspores from quickly becoming clogged with residues (broken off flash, deposits from the molding material, so-called plate out, etc.). It is also interesting in this case that completely new possibilities with regard to mold design and processing technique result from the use of such materials. A. Design rules There are many rules for designing molds. These rules and standard practices are based on logic, past experience, convenience, and economy. For designing, mold making, and molding, it is usually of advantage to follow the rules. But occasionally, it may work out better if a rule is ignored and an alternative way is selected. In this text, the most common rules are noted, but the designer will learn only from experience which way to go. The designer must ever be open to new ideas and methods, to new molding and mold materials that may affect these rules.B. The basic mold1. Mold cavity space The mold cavity space is a shape inside the mold, “excavated” in such a manner that when the molding material is forced into this space it will take on the shape of the cavity space and, therefore, the desired product. The principle of a mold is almost as old as human civilization. Molds have metals into sand forms. Such molds, which are still used today in foundries, can be used only once because the mold is destroyed to release the product after it has solidified. Today, we are looking for permanent molds that can be used over and over. Now molds are made from strong, durable materials, such as steel, or from softer aluminum or metal alloys and even from certain plastics where a long mold life is not required because the planned production is small. In injection molding the plastic is injected into the cavity space with high pressure, so the mold must be strong enough to resist the injection pressure without deforming.2. Number of cavities Many molds, particularly molds for larger products, are built for only cavity space, but many molds, especially large production molds, are built with 2 or more cavities. The reason for this is purely economical. It takes only little more time to inject several cavities than to inject one. For example, a 4-cavity mold requires only one-fourth of the machine time of a single-cavity mold. Conversely, the production increases in proportion to the number of cavities. A mold with more cavities is more expensive to build than a single-cavity mold, but not necessarily 4 times as much as a single-cavity mold. But it may also require a larger machine with larger platen area and more clamping capacity, and because it will use 4 times the amount of plastic, it may need a large injection unit, so the machine hour cost will be higher than for a machine large enough for the smaller mold.3. Cavity shape and shrinkage The shape of the cavity is essentially the “negative” of the shape of the desired product, with dimensional allowance added to allow for shrinking of the plastic. The shape of the cavity is usually created with chip-removing machine tools, or with electric discharge machining, with chemical etching, or by any new method that may be available to remove metal or build it up, such as galvanic processes. It may also be created by casting certain metals in plaster molds created from models of the product to be made, or by casting some suitable hard plastics. The cavity shape can be either cut directly into the mold plates or formed by putting inserts into the plates.C. Cavity and core By convention, the hollow portion of the cavity space is called the cavity. The matching, often raised portion of the cavity space is called the core. Most plastic products are cup-shaped. This does not mean that they look like a cup, but they do have an inside and an outside. The outside of the product is formed by the cavity, the inside by the core. The alternative to the cup shape is the flat shape. In this case, there is no specific convex portion, and sometimes, the core looks like a mirror image of the cavity. Typical examples for this are plastic knives, game chips, or round disks such as records. While these items are simple in appearance, they often present serious molding problems for ejection of the product. The reason for this is that all injection molding machines provide an ejection mechanism on the moving platen and the products tend to shrink onto and cling to the core, from where they are then ejected. Most injection molding machines do not provide ejection mechanisms on the injection side.Polymer Processing Polymer processing, in its most general context, involves the transformation of a solid (sometimes liquid) polymeric resin, which is in a random form (e.g., powder, pellets, beads), to a solid plastics product of specified shape, dimensions, and properties. This is achieved by means of a transformation process: extrusion, molding, calendaring, coating, thermoforming, etc. The process, in order to achieve the above objective, usually involves the following operations: solid transport, compression, heating, melting, mixing, shaping, cooling, solidification, and finishing. Obviously, these operations do not necessarily occur in sequence, and many of them take place simultaneously. Shaping is required in order to impart to the material the desired geometry and dimensions. It involves combinations of viscoelastic deformations and heat transfer, which are generally associated with solidification of the product from the melt. Shaping includes: two-dimensional operations, e.g. die forming, calendaring and coating; three-dimensional molding and forming operations. Two-dimensional processes are either of the continuous, steady state type (e.g. film and sheet extrusion, wire coating, paper and sheet coating, calendaring, fiber spinning, pipe and profile extrusion, etc.) or intermittent as in the case of extrusions associated with intermittent extrusion blow molding. Generally, molding operations are intermittent, and, thus, they tend to involve unsteady state conditions. Thermoforming, vacuum forming, and similar processes may be considered as secondary shaping operations, since they usually involve the reshaping of an already shaped form. In some cases, like blow molding, the process involves primary shaping (pair-son formation) and secondary shaping (pair son inflation). Shaping operations involve simultaneous or staggered fluid flow and heat transfer. In two-dimensional processes, solidification usually follows the shaping process, whereas solidification and shaping tend to take place simultaneously inside the mold in three dimensional processes. Flow regimes, depending on the nature of the material, the equipment, and the processing conditions, usually involve combinations of shear, extensional, and squeezing flows in conjunction with enclosed (contained) or free surface flows. The thermo-mechanical history experienced by the polymer during flow and solidification results in the development of microstructure (morphology, crystallinity, and orientation distributions) in the manufactured article. The ultimate properties of the article are closely related to the microstructure. Therefore, the control of the process and product quality must be based on an understanding of the interactions between resin properties, equipment design, operating conditions, thermo-mechanical history, microstructure, and ultimate product properties. Mathematical modeling and computer simulation have been employed to obtain an understanding of these interactions. Such an approach has gained more importance in view of the expanding utilization of computer design/computer assisted manufacturing/computer aided engineering (CAD/CAM/CAE) systems in conjunction with plastics processing. It will emphasize recent developments relating to the analysis and simulation of some important commercial process, with due consideration to elucidation of both thermo-mechanical history and microstructure development. As mentioned above, shaping operations involve combinations of fluid flow and heat transfer, with phase change, of a visco-elastic polymer melt. Both steady and unsteady state processes are encountered. A scientific analysis of operations of this type requires solving the relevant equations of continuity, motion, and energy (I. e. conservation equations).Injection Molding Many different processes are used to transform plastic granules, powders, and liquids into final product. The plastic material is in moldable form, and is adaptable to various forming methods. In most cases thermoplastic materials are suitable for certain processes while thermosetting materials require other methods of forming. This is recognized by the fact that thermoplastics are usually heated to a soft state and then reshaped before cooling. Theromosets, on the other hand have not yet been polymerized before processing, and the chemical reaction takes place during the process, usually through heat, a catalyst, or pressure. It is important to remember this concept while studying the plastics manufacturing processes and the polymers used. Injection molding is by far the most widely used process of forming thermoplastic materials. It is also one of the oldest. Currently injection molding accounts for 30% of all plastics resin consumption. Since raw material can be converted by a single procedure, injection molding is suitable for mass production of plastics articles and automated one-step production of complex geometries. In most cases, finishing is not necessary. Typical products include toys, automotive parts, household articles, and consumer electronics goods, Since injection molding has a number of interdependent variables, it is a process of considerable complexity. The success of the injection molding operation is dependent not only in the proper setup of the machine variables, but also on eliminating shot-to-shot variations that are caused by the machine hydraulics, barrel temperature variations, and changes in material viscosity. Increasing shot-to-shot repeatability of machine variables helps produce parts with tighter tolerance, lowers the level of rejects, and increases product quality ( i.e., appearance and serviceability). The principal objective of any molding operation is the manufacture of products: to a specific quality level, in the shortest time, and using a repeatable and fully automatic cycle. Molders strive to reduce or eliminate rejected parts, or parts with a high added value such as appliance cases, the payoff of reduced rejects is high. A typical injection molding cycle or sequence consists of five phases:1 Injection or mold filling2 Packing or compression3 Holding4 Cooling5 Part ejectionInjection Molding OverviewProcessInjection molding is a cyclic process of forming plastic into a desired shape by forcingthe material under pressure into a cavity. The shaping is achieved by cooling(thermoplastics) or by a chemical reaction (thermosets). It is one of the most commonand versatile operations for mass production of complex plastics parts with excellentdimensional tolerance. It requires minimal or no finishing or assembly operations. Inaddition to thermoplastics and thermosets, the process is being extended to suchmaterials as fibers, ceramics, and powdered metals, with polymers as binders.ApplicationsApproximately 32 percent by weight of all plastics processed go through injection moldingmachines. Historically, the major milestones of injection molding include the invention of thereciprocating screw machine and various new alternative processes, and the application of computersimulation to the design and manufacture of plastics parts.Development of the injection molding machineSince its introduction in the early 1870s, the injection molding machine has undergone significantmodifications and improvements. In particular, the invention of the reciprocating screw machine hasrevolutionized the versatility and productivity of the thermoplastic injection molding process.Benefits of the reciprocating screwApart from obvious improvements in machine control and machine functions, the majordevelopment for the injection molding machine is the change from a plunger mechanism to areciprocating screw. Although the plunger-type machine is inherently simple, its popularity waslimited due to the slow heating rate through pure conduction only. The reciprocating screw canplasticize the material more quickly and uniformly with its rotating motion, as shown in Figure 1. Inaddition, it is able to inject the molten polymer in a forward direction, as a plunger.Development of the injection molding processThe injection molding process was first used only with thermoplastic polymers. Advances in theunderstanding of materials, improvements in molding equipment, and the needs of specific industrysegments have expanded the use of the process to areas beyond its original scope.Alternative injection molding processesDuring the past two decades, numerous attempts have been made to develop injection moldingprocesses to produce parts with special design features and properties. Alternative processes derivedfrom conventional injection molding have created a new era for additional applications, more designfreedom, and special structural features. These efforts have resulted in a number of processes,including: Co-injection (sandwich) molding Fusible core injection molding) Gas-assisted injection molding Injection-compression molding Lamellar (microlayer) injection moldin Live-feed injection molding Low-pressure injection molding Push-pull injection molding Reactive molding Structural foam injection molding Thin-wall moldingComputer simulation of injection molding processesBecause of these extensions and their promising future, computer simulation of the process has alsoexpanded beyond the early lay-flat, empirical cavity-filling estimates. Now, complex programs simulate post-filling behavior, reaction kinetics, and the use of two materials with different properties, or two distinct phases, during the process.The Simulation section provides information on using C-MOLD products.Among the Design topicsare several examples that illustrate how you can use CAE tools to improve your part and molddesign and optimize processing conditions.Co-injection (sandwich) moldingOverviewCo-injection molding involves sequential or concurrent injection of two different butcompatible polymer melts into a cavity. The materials laminate and solidify. This processproduces parts that have a laminated structure, with the core material embedded betweenthe layers of the skin material. This innovative process offers the inherent flexibility ofusing the optimal properties of each material or modifying the properties of the moldedpart.FIGURE 1. Four stages of co-injection molding. (a) Short shot of skin polymer melt (shown in dark green)is injected into the mold. (b) Injection of core polymer melt until cavity is nearly filled, as shown in (c). (d)Skin polymer is injected again, to purge the core polymer away from the sprue.Fusible core injection moldingOverviewThe fusible (lost, soluble) core injection molding process illustrated below producessingle-piece, hollow parts with complex internal geometry. This process molds a coreinside the plastic part. After the molding, the core will be physically melted or chemicallydissolved, leaving its outer geometry as the internal shape of the plastic part.FIGURE 1. Fusible (lost, soluble) core injection moldingGas-assisted injection moldingGas-assisted processThe gas-assisted injection molding process begins with a partial or full injection ofpolymer melt into the mold cavity. Compre