塑料瓶蓋注射模具設計【說明書+CAD】

塑料瓶蓋注射模具設計【說明書+CAD】,說明書+CAD,塑料瓶蓋注射模具設計【說明書+CAD】,塑料,瓶蓋,注射,模具設計,說明書,仿單,cad 目 錄 緒論-----------------------------------2 第1章 對塑料成型模具設計的認識---------------3 1.1 模具工業(yè)現狀------------------------4 1.2 發(fā)展模具的積極意義--------------------4 1.3 我國的模具將呈現十大發(fā)展趨勢------------5 第2章 設計過程---------------------------7 2.1 塑料成型制品的分析---------------------------7 2.2 注射成型工藝的設計---------------------------8 2.3 注射機的技術規(guī)范-----------------------------12 第3章 模具的結構設計-------------------------------14 3.1 注射機的鎖模力-------------------------------14 3.2 成型零件的設計-------------------------------16 第4章 模具結構零件設計-----------------------------17 4.1 導柱和導套---------------------------------- 17 4.2 推桿、復位桿及拉料桿-------------------------17 4.3 限位釘、墊塊---------------------------------18 4.4 定位圈與澆口套-------------------------------18 4.5 模板-----------------------------------------18 4.6 擋塊、限位塊---------------------------------18 參考資料-------------------------------19 體會與感受--------------------- 19 緒 論 模具工業(yè)是制造業(yè)中的一項基礎產業(yè)，是技術成果轉化的基礎，同時本身又是高新技術產業(yè)的重要領域，在歐美等工業(yè)發(fā)達國家被稱為“點鐵成金”的“磁力工業(yè)”。美國工業(yè)界認為“模具工業(yè)是美國工業(yè)的基石”；德國則認為是所有工業(yè)中的“關鍵工業(yè)”；日本模具協(xié)會也認為“模具是促進社會繁榮富裕的動力”，同時也是“整個工業(yè)發(fā)展的秘密”，是“進入富裕社會的原動力”。日本模具產業(yè)年產值達到13000億日元，遠遠超過日本機床總產值9000億日元。如今，世界模具工業(yè)的發(fā)展甚至已超過了新興的電子工業(yè)。 　　我國國民經濟的高速發(fā)展對模具工業(yè)提出了越來越高的要求，預計到2005年，僅汽車行業(yè)將需要各種塑料制件36萬噸；電冰箱、洗衣機和空調的年產量均超過1000萬臺；彩電的年產量已超過3000萬臺。 　　近年來，我國的模具工業(yè)一直以每年13%左右的增長速度快速發(fā)展。據預測，我國模具行業(yè)在“十五”期間的增長速度將達到13%～15%。模具鋼的需求量也將以年12%的速度遞增，全國年需求量約70萬噸左右，而國產模具鋼的品種只占現有國外模具鋼品種的60%，每年進口模具鋼約6萬噸。我國每年進口模具約占市場總量的20%左右，已超過10億美元，其中塑料與橡膠模具占全部進口模具的50%以上；沖壓模具占全部進口模具約40%。 　　目前，全世界模具的年產值約為650億美元，我國模具工業(yè)的產值在國際上排名位居第三位，僅次于日本和美國。雖然近幾年來，我國模具工業(yè)的技術水平已取得了很大的進步，但總體上與工業(yè)發(fā)達的國家相比仍有較大的差距。例如，精密加工設備還很少，許多先進的技術如CAD/CAE/CAM技術的普及率還不高，特別是大型、精密、復雜和長壽命模具遠遠不能滿足國民經濟各行業(yè)的發(fā)展需要。 　　縱觀發(fā)達國家對模具工業(yè)的認識與重視，我們感受到制造理念陳舊則是我國模具工業(yè)發(fā)展滯后的直接原因。模具技術水平的高低，決定著產品的質量、效益和新產品開發(fā)能力，它已成為衡量一個國家制造業(yè)水平高低的重要標志。目前，我國模具工業(yè)的當務之急是加快技術進步，調整產品結構，增加高檔模具的比重，質中求效益，提高模具的國產化程度，減少對進口模具的依賴。 現代模具技術的發(fā)展，在很大程度上依賴于模具標準化、優(yōu)質模具材料的研究、先進的設計與制造技術、專用的機床設備，更重要的是生產技術的管理等。21世紀模具行業(yè)的基本特征是高度集成化、智能化、柔性化和網絡化。追求的目標是提高產品的質量及生產效率，縮短設計及制造周期，降低生產成本，最大限度地提高模具行業(yè)的應變能力，滿足用戶需要?？梢姡磥砦覈＞吖I(yè)和技術的主要發(fā)展方向將是： 　——大力普及、廣泛應用CAD/CAE/CAM技術，逐步走向集成化。現代模具設計制造不僅應強調信息的集成，更應該強調技術、人和管理的集成。 　　——提高大型、精密、復雜與長壽命模具的設計與制造技術，逐步減少模具的進口量，增加模具的出口量。 　 ——在塑料注射成型模具中，積極應用熱流道，推廣氣輔或水輔注射成型，以及高壓注射成型技術，滿足產品的成型需要。 　　——提高模具標準化水平和模具標準件的使用率。模具標準件是模具基礎，其大量應用可縮短模具設計制造周期，同時也顯著提高模具的制造精度和使用性能，大大地提高模具質量。我國模具商品化、標準化率均低于30%，而先進國家均高于70%，每年我們要從國外進口相當數量的模具標準件，其費用約占年模具進口額的3%～8%。 　　——發(fā)展快速制造成型和快速制造模具，即快速成型制造技術，迅速制造出產品的原型與模具，降低成本推向市場。 　　——積極研究與開發(fā)模具的拋光技術、設備與材料，滿足特殊產品的需要。 　　——推廣應用高速銑削、超精度加工和復雜加工技術與工藝，滿足模具制造的需要。 　　——開發(fā)優(yōu)質模具材料和先進的表面處理技術，提高模具的可靠性。 　　——研究和應用模具的高速測量技術、逆向工程與并行工程，最大限度地提高模具的開發(fā)效率與成功率。 在科技發(fā)展中，人是第一因素，因此我們要特別注重人才的培養(yǎng)，實現產、學、研相結合，培養(yǎng)更多的模具人才，搞好技術創(chuàng)新，提高模具設計制造水平。在制造中積極采用多媒體與虛擬現實技術，逐步走向網絡化、智能化環(huán)境，實現模具企業(yè)的敏捷制造、動態(tài)聯盟與系統(tǒng)集成。 第一章 對塑料成型模具設計的認識 隨著工業(yè)的發(fā)展，模具所占的地位越來越重要，尤其是塑料模具，其應用更加廣泛，技術含量更高，我們每天都在享用這它帶來的成果。 塑料制件在工業(yè)中的應用日趨普遍，這是由于他們具有一系列特殊優(yōu)點所決定的。塑料密度小，質量輕，大多數塑料密度在1.0－1.4之間，相當于鋼材密度的0.11和鋁材的0.5左右，即在同樣的體積下，塑料制件要比金屬制件輕得多，這就是以塑代鋼的優(yōu)點。 模具是工業(yè)生產中的重要工藝裝備，模具工業(yè)是國民經濟各部門的重要基礎之一，塑料模是指用于成型塑料制件的模具，它是型腔的一種類型。模具設計水平的高低，加工設備的好壞，制造力量的強弱，模具質量的優(yōu)劣，直接影響著許多新產品的開發(fā)和老產品的更新換代，影響著產品的質量和經濟效益的提高。 5模具工業(yè)現狀 由于歷史原因形成的封閉式、“大而全”的企業(yè)特征，我國大部分企業(yè)均設有模具車間，處于本廠的配套地位，自70年代末才有了模具工業(yè)化和生產專業(yè)化這個概念。模具工業(yè)主要生產能力分散在各部門主要產品廠內的工模具車間，所生產的模具基本自產自用。據粗略估計，產品廠的模具生產能力占全國模具生產能力的75％，他們的裝備水平較好，技術力量較強，生產潛力較大，但主要為本廠產品服務，與市場聯系較少，經營機制不靈活，不能發(fā)揮人力物力的潛力。模具專業(yè)廠全國只有二百家左右，商品模具只占總數的20％左右，模具標準件的商品率也不到20％。由于受舊管理體制的影響較深，缺乏統(tǒng)籌規(guī)劃和組織協(xié)調，存在著“中而全”，“小而全”的結構缺陷，生產效率不高，經濟效益較差。 一、 發(fā)展模具的積極意義 中國經濟的持續(xù)高速發(fā)展，為模具工業(yè)的發(fā)展提供了廣闊的空間。模具行業(yè)在今后的發(fā)展中，首先要更加注意其產品結構的戰(zhàn)略性調整，使結構復雜、精密度高的高檔模具得到更快的發(fā)展。我們的模具行業(yè)要緊緊地跟著市場的需求來發(fā)展。沒有產品的需求、產品的更新換代，就沒有模具行業(yè)的技術進步，也就沒有模具產品的上規(guī)模、上檔次。如汽車生產中90%以上的零部件，都要依靠模具成形，在珠三角和長三角，為汽車行業(yè)配套的模具產值增長達40%左右。 其次，要積極推進中西部地區(qū)模具產業(yè)的發(fā)展，努力縮小發(fā)達地區(qū)和不發(fā)達地區(qū)的差距。中西部很多地區(qū)已經意識到模具產業(yè)的發(fā)展對制造業(yè)的重要作用。如陜西、四川、河北等模具生產企業(yè)的生產規(guī)模、技術水平都有了很大的發(fā)展。 第三，要積極推進模具企業(yè)特別是國有企業(yè)的體制創(chuàng)新，轉換經營機制，大力發(fā)展混合所有制經濟，明晰產權和完善法人治理結構。充分發(fā)掘企業(yè)發(fā)展的內在動力。要積極推進中、西部工業(yè)基礎較好地區(qū)的制造業(yè)大中型企業(yè)主輔分離，使其模具車間、分廠在不太長的時間里，采用多種有效實現形式，轉換機制，大力發(fā)展產權明晰、獨立自主經營，適應市場運作和模具生產快速反應的現代專業(yè)模具企業(yè)，培養(yǎng)能代表行業(yè)水平的“龍頭”企業(yè)，帶動地區(qū)產業(yè)鏈的發(fā)展。 二、 我國的模具將呈現十大發(fā)展趨勢 一是模具日趨大型化。這是由于用模具成型的零件日漸大型化 和高生產效率要求發(fā)展的“一模多腔”所造成的。 二是模具的精度將越來越高。10年前精密模具的精度一般為5微米，現在已達到2-3微米，不久1微米精度的模具將上市。這要求超精加工。 三是多功能復合模具將進一部發(fā)展。新型多功能復合模具除了沖壓成型零件外，還擔負疊壓、攻絲、鉚接和鎖緊等組裝任務，對鋼材的性能也要求越來越高。 四是熱流道模具在塑料模具中的比重也將逐漸提高。由于采用熱流道技術的模具可提高制件的生產率和質量，并能大幅度節(jié)約制作的原材料，因此熱流道技術的應用在國外發(fā)展很快，許多塑料模具廠所生產的塑料模具一半以上采用了熱流道技術，有的廠家使用率達到80%以上，效果十分明顯。熱流道模具在我國也已生產，有些企業(yè)使用率上升到20%—30%。 五是隨著塑料成型工藝的不斷改進與發(fā)展，氣輔模具及適應高壓注塑成型等工藝的模具將隨之發(fā)展。這類模具要求剛性好，耐高壓，特別是精密模具的型腔應淬火，澆口密封性好，模溫能準確控制，所以對模具鋼的性能要求很強。 六是標準件的應用將日益廣泛。模具標準化及模具標準件的應用將極大地影響模具制造周期，且還能提高模具的質量和降低模具制造成本。因此，模具標準件的應用在“十五”期間必將得到較大的發(fā)展。 第2章 設計過程 塑料模具分類的方法很多，按照塑料制作的成型方法不同可分為以下幾類： 注射模，壓縮模，擠出模，氣動成型模 本次設計主要是注射模，又叫注塑模，注射成型是根據金屬壓鑄成型原理發(fā)展起來的，首先將粒狀或粉末狀的塑料原料加入到注射機的料筒中，經過加熱熔融成粘流態(tài)，然后在柱塞或螺桿的推動下，以一定的流速通過料筒前端的噴嘴和模具的澆注系統(tǒng)，注射入閉合的模具型腔中，經過一定的時間后，模具在模內硬化成型，近幾年來，熱固性塑料注射成型的應用也在逐漸增加。 塑料制件主要是靠成型模具獲得的，而它的質量是靠模具的正確結構和模具成型零件的正確形狀，精確尺寸及較低的表面粗糙度來保證的。由于塑料成型工藝的飛速發(fā)展，模具的結構也日益趨于多功能和復雜化，這對模具的設計工作提出了更高的要求。雖然模具制作的質量與許多因素有關，但合格的塑料制作首先取決于模具的設計與制造的質量，其次取決與合理的成型工藝。塑料成型加工技術發(fā)展很快，塑料模具的各種結構也在不斷的創(chuàng)新，我們在學習成型的同時，還應注意了解塑料模具的新技術、新工藝和新材料的發(fā)展動態(tài)，學習和掌握新知識，為振興我國的塑料成型加工技術做出貢獻。 一、 塑料成型制品的分析 1、 制品的設計要求 本次設計制品的用途是塑料瓶蓋，形狀較復雜，但基本對稱，精度要求中等。 2、 制品的生產批量 本制品為大批量生產，為了縮短周期，提高生產率，制品使用一模兩腔和全自動化生產，利用模具的頂出機構，將制品推出模腔，再利用拉料桿和二次脫模機構使制品流道凝料脫落。為了提高生產率，制品在模具中直接成型。 3、 制品成型設計 按照與以往的設計經驗，該瓶蓋制品使用二次分型機構，采用點澆口形式，雖然其他的澆口形式還有直接澆口、側澆口、扇形澆口、薄片式澆口、環(huán)行澆口、輪輻澆口、爪形澆口、潛伏澆口、護耳澆口等，但他們都不容易在開模時實現自動切斷，而點澆口就具有這個優(yōu)點，而且其留于塑件的疤痕較小，不影響塑件外觀。 4、 抽芯機構的設計 在塑件中間有兩個用于翻蓋時起旋轉固定作用的半圓球，如果設計一抽芯機構用于該球的成型，則在抽出時易于產生干涉現象，而且由于該處的尺寸形狀比較小，模具的抽芯機構制造比較困難，對模具的制造工藝要求比較高，從而影響了模具的成本，為了簡化該處抽芯問題，考慮到制品是塑料制品，具有一定的收縮性，同時為了更好的控制制造成本，將模具機構合理的簡化，故本機構不采用側向抽芯，改為由頂桿直接將模具頂出。 5、 制品的質量和體積 塑件質量：m=10.5 g ABS密度：=1.04 g/cm 所以 V=m/=10.09 cm 二、 注射成型工藝的設計 1、塑料制品分析 本制品采用ABS為原料（模具與制造簡明手冊P272）苯乙烯—丁二烯—丙烯氰共聚物。 （1） 無定性料，流動性中等，比聚苯乙烯、AS差，但比聚氯乙烯好，溢邊值為0.04 mm左右。 （2） 吸濕性強，必須充分干燥，表面要求光澤的塑料須經長時間的預熱干燥。 （3） 成型時宜取高料溫，但料溫過高易分解（分解溫度≥250℃），對精度較高的塑料，模溫宜取50～60℃，對光澤要求較高的耐熱塑料模溫宜取60～80℃，注射壓力高于聚苯乙烯。用柱塞式注射機成型時，料溫為180～200℃，注射壓力為1000～1400MPa，用螺桿式注射機成型時，料溫為160～220℃，注射壓力為700～1000×10MPa。 （4） ABS的其他成型工藝參數 注射機類型：螺桿式 制品收縮率：0.3～0.8% 預熱溫度：80～85℃ 時間：2～3 h 料筒溫度： 后段 150～170℃ 中段 165～180℃ 前段 180～200℃ 噴嘴溫度：170～180℃ 模具溫度：50～80℃ 注射壓力：60～100 MPa 成型時間： 注射時間20～90 s 保壓時間0～5 s 冷卻時間20～120 s 總周期50～220 s 螺桿轉速：30 r/min 適用注射機類型：螺桿、柱塞均可 后處理方法：紅外線燈、鼓風烘箱 溫度70℃ 時間2～4 h 2、制品成型方法及工藝流程 本制品采用注射成型，工藝流程包括模前準備，模塑成型和后處理及二次加工工藝流程步驟如下： （1）預熱 ABS吸濕性強，必須充分干燥，表面要求光澤的塑料須經長時間的預熱干燥。 （2）注射 注射過程包括加料、塑化、注射冷卻和脫模幾個步驟。 l 加料 由于注射成型是一個間歇過程，因而須定量（定容）加料，以保證操作穩(wěn)定，塑料塑化均勻，最終獲得良好的塑件。加料過多。受熱的時間過長等容易引起物料的熱降解，同時注射及功率損耗增多；加料過少，料筒內缺少傳壓介質，型腔中塑料融化壓力降低，難于補料，容易引起塑件出現收縮、凹陷、空洞等缺陷。 l 塑化 加入的塑料在料筒中進行加熱，由固體顆粒轉化成粘流態(tài)，并且受到良好的剪切力作用。通過料筒對物料加熱，使聚合物分子松弛，出現由固體向液體轉變；一定的溫度使塑料得到變形、熔融和塑化的必要條件，螺桿的剪切作用能在塑料中產生更多的摩擦熱，促進了塑料的塑化，因而螺桿式注射機對塑料的溫度盡量均勻一致，還有使熱分解物的含量達到最小值，并且能提供上述質量的足夠的熔融塑料以保證產生連續(xù)并順利的進行，這些要求與塑料的特性、工藝條件的控制及注射機的塑化裝置的結構等密切相關。 l 注射 不論何種形式的注射機，注射的過程可分為充模，保壓倒流，澆口凍結后的冷卻和脫模等幾個階段 （3）塑件的后處理 注射成型的塑件經脫?；驒C械加工之后，常需要進行適當的后處理以消除存在的內應力，改善塑件的性能和提高尺寸穩(wěn)定性。其主要方法是退火和調濕處理。退火處理是將注射塑件在定溫的加熱液體介質或熱烘箱中靜置一段時間，塑料制件的氧化，加快吸濕平衡速度的一種處理方法，其目的是使制作的顏色、性能以及尺寸得到穩(wěn)定。本次設計采用退火后處理。 工藝流程圖解： 3、成型工藝條件 注射成型的核心問題，就是采用一切措施得到塑化良好的塑料 熔體，并把它注射到型腔中去，在控制條件下冷卻定型，使塑件 達到所要求的質量，影響注射成型工藝的重要參數是塑化流動和 冷卻的溫度、壓力以及影響的各個作用時間。 （1）注射成型過程需要控制的溫度有料筒溫度，噴嘴溫度和模具溫度等。前兩個溫度主要影響塑件的塑化和流動，而后一個溫度主要是影響塑件的流動和冷卻，料筒溫度的選擇與各種塑料的特性有關。每種塑料都具有不同的粘流態(tài)溫度，為了保證塑件溶體的正常流動不使物料發(fā)生質分解，料筒最合適的溫度范圍應在粘流態(tài)溫度和熱分解溫度之間。 柱塞式和螺桿式柱塞注射機由于其塑化過程不同，因而選擇料筒也不同，通常后者選擇的溫度低一點，料筒溫度在70～93℃之間，噴嘴溫度稍低于料筒溫度，在65～90℃之間，模溫在要求塑件光澤時控制在60～80℃之間。 （2）壓力包括塑化壓力和注射壓力兩種，他們直接影響塑料的塑化和塑料質量。塑化壓力是指背壓，是指采用螺桿式注射機時，螺桿頭部熔體在螺桿轉動后退時所受到的壓力，塑化壓力在保證塑件質量的前提下越低越好，其具體數值時隨所用塑料的品種而異的，但通常很少超過20MP，注射壓力是指柱塞式螺桿頭部對塑件熔體所施加的壓力。在注射機上常用表壓指示注射壓力的大小，一般在40～130MP之間。其作用式克服塑料熔體從料筒流向型腔的流動阻力，給予熔體一定的充型速率以及對熔體進行壓實等。 （3）完成一次注射成型過程所需要的時間稱成型周期，成型周期直接影響到勞動生產率和注射機使用率，因此在生產中，在保證質量的前提下，盡量縮短成型周期中各個階段的有關時間，一般生產中，充模時間為3～5S，保壓時間為20～25S，冷沖壓時間一般在30～120S。 三、 注射機的技術規(guī)范 1、 注射機的選用 注射機的選用包括兩方面的內容：一是要確定注射機的型號，使塑料、塑件、注射模、注射工藝等所要求的注射機的規(guī)格參數點在所選注射機的規(guī)格參數可調范圍之內，即要滿足所需的參數在額定的范圍之內；二是調整注射機的技術參數至所需的參數點。 塑件的直徑：d=66 mm 所以塑件的投影面積s=П×(d/2)=3.14×(66÷2)≈3419.46 mm 澆道凝料的質量大約為20 g，澆注系統(tǒng)的投影面積大約為300 mm l 擬定一次成型8個塑件 （1）注射量的校核 根據公式K×G=Q+Q’ K—注射機公稱質量注射量(g） G—注射機最大注射量的利用系數，一般取0.75～0.85 Q—塑件的質量(g） Q’—澆注系統(tǒng)等廢料的質量(g） 所以所需注射機的注射量K=(Q+Q’)/G=(2.5×8+20)÷0.85 ≈47.1 g （2）鎖模力的校核 鎖模力必須大于模具在模具在開模方向得投影面積上的總注射壓力。根據要求，鎖模力不小于總注射壓力的1.2倍，即要取一安全系數，以保證安全生產。 所以F≥A×P×S F—注射機的鎖模力（KN） P—型腔單位面積的注射壓力（MPa），ABS的壓力值約為80MPa S—型腔（包括澆注系統(tǒng)）的投影面積（mm） A—安全系數，本設計取1.4 即F≥)≈15000 KN 根據要求選得的注射機型號為SZ—250/1250，但該注射機過于龐大，能源損耗大，用于生產本次設計塑件不合理，故修改生產方案。 l 擬定一次成型4個塑件 （1）注射量的校核 根據公式K×G=Q+Q’?得K=(Q+Q)/G=(2.5×4+20)÷0.85 =25.5 g （2）鎖模力的校核 根據公式F≥A×P×S 得F≥1600 根據要求選得的注射機型號為SZ—100/630，該型號的注射機比較經濟合理，故本設計采用該注射機。 2、 注射機的確定 本次設計采用螺桿式注射機，型號是SZ-300/160 它的主要參數為： 理論注射容積：300 cm 螺桿直徑：45mm 注射壓力：150 MPa 注射速率：145g/s 塑化能力：82 g/s 螺桿轉速：0～180 r/min 鎖模力：1600KN 拉桿內間距：450×450 mm 移模行程：L=380mm 模具定位孔直徑：160 mm 最大模具厚度：Hmax=450 mm 最小模具厚度：Hmin=250 mm 模具噴嘴球半徑：R=20mm ⒋ 三 模具結構零件設計 ㈠. 導柱和導套 用于動模與定模間或推出機構零件的定位和導向. ⒈ 導柱 導柱具有與動模之間的導向作用,同時也具有保護模具的作用.導柱的導向部分應具有較好的滑動性能, 一般應沒有潤滑油槽. 其硬度應在50HRC以上, 采用銅為原料,經淬火后導柱的滑動配合部分在進行磨消加工,表面粗糙度到達Ra 0.63μm. ⒉導套 通常在模板上鑲配導套以減少導柱滑動部分的磨損. 采用錫青銅為原料. ㈠ 推桿.復位桿及拉料桿 ⒈ 推桿 推桿用于推出塑件的桿類零件, 通稱為推桿.要求外觀無傷痕, 裂紋及銹斑等缺陷. 配合部分需進行加工, 表面粗糙度到達Ra 0.63μm以下. 推桿前端部分淬火后硬度到達55HRC以上. ⒉ 復位桿也稱回程桿, 它是用于使推出機構復位的桿類零件. 復位桿用材料與加工要求與推桿相同. ⒊ 拉料桿 用于拉出主流道凝料或分流道凝料的一類桿狀零件. 通稱為拉料桿. 根據其功能作用的不同,又可分為主道拉料桿和分道拉料桿兩種. 主道拉料桿是用來從澆口套中拉出主流道凝料的零件. 分道拉料桿是用來拉出針點澆口并使之與模塑件斷開的桿類零件,其前端形狀視樹脂種類不同兒異. ㈡ 定位圖與澆口套 ⒈ 定位圖 定位圖的作用是使注射機的噴嘴與模具主流澆口保持同心. 定位圖為標準型與特殊型兩種. 由于此此模具為普通模具.因此選甲標準型. ⒉ 澆口套 通常澆口套與定位圖是配合使用的. 澆口套是塑料熔體熔入模具的入口,其尺寸與注塑機噴嘴尺寸有關. 本模具選用標準澆口套中的A 型. ㈢ 限位釘, 墊塊 ⒈ 限位釘 限位釘安裝在動模板上,用于確定推板下限位置. ⒉ 墊塊 墊塊用以決定推出模塑件的距離,調節(jié)高度一類塊狀零件. ㈣ 斜銷, 側滑塊, 導滑槽 ⒈ 斜銷 斜銷是用于驅動側滑塊進行側向分型或的構件.選其傾斜角為20°,淬火后硬度在55HRC以上,并須進行磨削加工. ⒉ 側滑塊 側滑塊通常有側型芯 ,滑動部分及本體組成,其硬度在40HRC以上. ⒊ 導滑槽 導滑槽是用于支撐側滑塊進行抽芯運動的機構 ㈤ 模板. 模板于固定凹凸槽,各類桿件,導柱和導套等各類成型零件的板類.多用45＃開鋼制造,為拉提高模具壽命,加工后須要淬火. ㈥ 擋塊, 彈簧, 限位塊 ⒈ 擋塊 它是用于在模具開模以后,防止側滑塊由于抽芯力的作用而脫離模具整體,一般將其固定在動模板上. ⒉ 彈簧 彈簧它是用于在模具開模以后, 防止側滑塊向塑件而破壞塑件的抽芯,將它固定在擋板塊的雙頭螺栓柱上. ⒊ 限位塊 限位塊是用來定位側滑塊,一般將其固定在定模板上整體加工出來. 參考資料 在設計過程中所查閱的書籍如下： 《模具設計于制作技術基礎》 《典型模具設計圖例》 《實用塑料注射模設計與制造》 《機械原理》 《機械基礎》 體會與感受(宋小2號) （通過畢業(yè)設計自己的體會和感受，在哪些方面有經驗、教訓和提高。） 在本次畢業(yè)設計中，我從指導老師身上學到了很多東西。老師認真負責的工作態(tài)度，嚴謹的治學精神和深厚的理論水平都使我收益匪淺。他無論在理論上還是在實踐中，都給與我很大的幫助，使我得到不少的提高這對于我以后的工作和學習都有一種巨大的幫助，感謝他耐心的輔導 。 在設計期間由于模具設計是第一次有點無從下手的感覺，上學期學過《塑料模具的設計》一課，對模具的結構不是太陌生，再加上老師的指導，數據的來源較快，畫圖的工作量太大，使我有些招架不住。還好由于我平時CAD學得還行，再加上系里同學提供方便，在這么多人的關心下，我的進展很快，草圖在一天內完成，兩天內也完成了繪圖的三分之一，一周內完成了畢業(yè)設計。一學期的任務讓我在一周內完成了，工作量可想而知，但我沒有因為時間短而忽略了設計質量。在老師的指導下，我精心的查手冊，認真的計算和驗算著每一個數據，并根據我所設計的零件的特性，找出了比較完整的設計方案，并得到了指導老師得認可。嚴格的按照要求繪圖，終于在答辯之前完成了畢業(yè)設計。 總之，畢業(yè)設計期間，我體驗到了許多以前少能體驗到的東西。 21 級畢業(yè)設計（論文） 課題名稱：塑料瓶蓋注射模設計 專 業(yè)：數控技術及應用 設 計 人 指導老師: 職 稱： 年 月 日 INEEL/CON-2000-00104 PREPRINT Spray-Formed Tooling for Injection Molding and Die Casting Applications K. M. McHugh B. R. Wickham June 26, 2000 June 28, 2000 International Conference on Spray Deposition and Melt Atomization This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint should not be cited or reproduced without permission of the author. This document was prepared as a account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third partys use, or the results of such use, of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights. The views expressed in this paper are not necessarily those of the U.S. Government or the sponsoring agency. BECHTEL BWXT IDAHO, LLC 1 Spray-Formed Tooling For Injection Molding and Die Casting Applications Kevin M. McHugh and Bruce R. Wickham Idaho National Engineering and Environmental Laboratory P.O. Box 1625 Idaho Falls, ID 83415-2050 e-mail: kmm4inel.gov Abstract Rapid Solidification Process (RSP) Tooling is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described. Introduction Molds, dies, and related tooling are used to shape many of the plastic and metal components we use every day at home or at work. The process involves machining the negative of a desired part shape (core and cavity) from a forged tool steel or a rough metal casting, adding cooling channels, vents, and other mechanical features, followed by grinding. Many molds and dies undergo heat treatment (austenitization/quench/temper) to improve the properties of the steel, followed by final grinding and polishing to achieve the desired finish 1. Conventional fabrication of molds and dies is very expensive and time consuming because: Each is custom made, reflecting the shape and texture of the desired part. The materials used to make tooling are difficult to machine and work with. Tool steels are the workhorse of industry for long production runs. Machining tool steels is capital equipment intensive because specialized equipment is often needed for individual machining steps. Tooling must be machined accurately. Oftentimes many individual components must fit together correctly for the final product to function properly. 2 Costs for plastic injection molds vary with size and complexity, ranging from about $10,000 to over $300,000 (U.S.), and have lead times of 3 to 6 months. Tool checking and part qualification may require an additional 3 months. Large die-casting dies for transmissions and sheet metal stamping dies for making automobile body panels may cost more than $1million (U.S.). Lead times are usually greater than 40 weeks. A large automobile company invests about $1 billion (U.S.) in new tooling each year to manufacture the components that go into their new line of cars and trucks. Spray forming offers great potential for reducing the cost and lead time for tooling by eliminating many of the machining, grinding, and polishing unit operations. In addition, spray forming provides a powerful means to control segregation of alloying elements during solidification and carbide formation, and the ability to create beneficial metastable phases in many popular ferritic tool steels. As a result, relatively low temperature precipitation hardening heat treatment can be used to tailor properties such as hardness, toughness, thermal fatigue resistance, and strength. This paper describes the application of spray forming technology for producing H13 tooling for injection molding and die casting applications, and the benefits of low temperature heat treatment. RSP Tooling Rapid Solidification Process (RSP) Tooling, is a spray forming technology tailored for producing molds and dies 2-4. The approach combines rapid solidification processing and net- shape materials processing in a single step. The general concept involves converting a mold design described by a CAD file to a tooling master using a suitable rapid prototyping (RP) technology such as stereolithography. A pattern transfer is made to a castable ceramic, typically alumina or fused silica (Figure 1). This is followed by spray forming a thick deposit of tool steel (or other alloy) on the pattern to capture the desired shape, surface texture and detail. The resultant metal block is cooled to room temperature and separated from the pattern. Typically, the deposits exterior walls are machined square, allowing it to be used as an insert in a holding block such as a MUD frame 5. The overall turnaround time for tooling is about three days, stating with a master. Molds and dies produced in this way have been used for prototype and production runs in plastic injection molding and die casting. Figure 1. RSP Tooling processing steps. 3 An important benefit of RSP Tooling is that it allows molds and dies to be made early in the design cycle for a component. True prototype parts can be manufactured to assess form, fit, and function using the same process planned for production. If the part is qualified, the tooling can be run in production as conventional tooling would. Use of a digital database and RP technology allows design modifications to be easily made. Experimental Procedure An alumina-base ceramic (Cotronics 780 6) was slurry cast using a silicone rubber master die, or freeze cast using a stereolithography master. After setting up, ceramic patterns were demolded, fired in a kiln, and cooled to room temperature. H13 tool steel was induction melted under a nitrogen atmosphere, superheated about 100C, and pressure-fed into a bench-scale converging/diverging spray nozzle, designed and constructed in-house. An inert gas atmosphere within the spray apparatus minimized in-flight oxidation of the atomized droplets as they deposited onto the tool pattern at a rate of about 200 kg/h. Gas-to-metal mass flow ratio was approximately 0.5. For tensile property and hardness evaluation, the spray-formed material was sectioned using a wire EDM and surface ground to remove a 0.05 mm thick heat-affected zone. Samples were heat treated in a furnace that was purged with nitrogen. Each sample was coated with BN and placed in a sealed metal foil packet as a precautionary measure to prevent decarburization. Artificially aged samples were soaked for 1 hour at temperatures ranging from 400 to 700C, and air cooled. Conventionally heat treated H13 was austenitized at 1010C for 30 min., air quenched, and double tempered (2 hr plus 2 hr) at 538C. Microhardness was measured at room temperature using a Shimadzu Type M Vickers Hardness Tester by averaging ten microindentation readings. Microstructure of the etched (3% nital) tool steel was evaluated optically using an Olympus Model PME-3 metallograph and an Amray Model 1830 scanning electron microscope. Phase composition was analyzed via energy- dispersive spectroscopy (EDS). The size distribution of overspray powder was analyzed using a Microtrac Full Range Particle Analyzer after powder samples were sieved at 200 m to remove coarse flakes. Sample density was evaluated by water displacement using Archimedes principle and a Mettler balance (Model AE100). A quasi 1-D computer code developed at INEEL was used to evaluate multiphase flow behavior inside the nozzle and free jet regions. The codes basic numerical technique solves the steady- state gas flow field through an adaptive grid, conservative variables approach and treats the droplet phase in a Lagrangian manner with full aerodynamic and energetic coupling between the droplets and transport gas. The liquid metal injection system is coupled to the throat gas dynamics, and effects of heat transfer and wall friction are included. The code also includes a nonequilibrium solidification model that permits droplet undercooling and recalescence. The code was used to map out the temperature and velocity profile of the gas and atomized droplets within the nozzle and free jet regions. 4 Results and Discussion Spray forming is a robust rapid tooling technology that allows tool steel molds and dies to be produced in a straightforward manner. Examples of die inserts are given in Figure 2. Each was spray formed using a ceramic pattern generated from a RP master. Figure 2. Spray-formed mold inserts. (a) Ceramic pattern and H13 tool steel insert. (b) P20 tool steel insert. Particle and Gas Behavior Particle mass frequency and cumulative mass distribution plots for H13 tool steel sprays are given in Figure 3. The mass median diameter was determined to be 56 m by interpolation of size corresponding to 50% cumulative mass. The area mean diameter and volume mean diameter were calculated to be 53 m and 139 m, respectively. Geometric standard deviation, d =(d 84 /d 16 ) , is 1.8, where d 84 and d 16 are particle diameters corresponding to 84% and 16% cumulative mass in Figure 3. 5 Figure 3. Cumulative mass and mass frequency plots of particles in H13 tool step sprays. Figure 4 gives computational results for the multiphase velocity flow field (Figure 4a), and H13 tool steel solid fraction (Figure 4b), inside the nozzle and free jet regions. Gas velocity increases until reaching the location of the shock front, at which point it precipitously decreases, eventually decaying exponentially outside the nozzle. Small droplets are easily perturbed by the velocity field, accelerating inside the nozzle and decelerating outside. After reaching their terminal velocity, larger droplets (150 m) are less perturbed by the flow field due to their greater momentum. It is well known that high particle cooling rates in the spray jet (10 3 -10 6 K/s) and bulk deposit (1- 100 K/min) are present during spray forming 7. Most of the particles in the spray have undergone recalescence, resulting in a solid fraction of about 0.75. Calculated solid fraction profiles of small (30 m) and large (150 m) droplets with distance from the nozzle inlet, are shown in Figure 4b. Spray-Formed Deposits This high heat extraction rate reduces erosion effects at the surface of the tool pattern. This allows relatively soft, castable ceramic pattern materials to be used that would not be satisfactory candidates for conventional metal casting processes. With suitable processing conditions, fine 6 Figure 4. Calculated particle and gas behavior in nozzle and free jet regions. (a) Velocity profile. (b) Solid fraction. 7 surface detail can be successfully transferred from the pattern to spray-formed mold. Surface roughness at the molding surface is pattern dependent. Slurry-cast commercial ceramics yield a surface roughness of about 1 m Ra, suitable for many molding applications. Deposition of tool steel onto glass plates has yielded a specular surface finish of about 0.076 m Ra. At the current state of development, dimensional repeatability of spray-formed molds, starting with a common master, is about 0.2%. Chemistry The chemistry of H13 tool steel is designed to allow the material to withstand the temperature, pressure, abrasion, and thermal cycling associated with demanding applications such as die casting. It is the most popular die casting alloy worldwide and second most popular tool steel for plastic injection molding. The steel has low carbon content (0.4 wt.%) to promote toughness, medium chromium content (5 wt%) to provide good resistance to high temperature softening, 1 wt% Si to improve high temperature oxidation resistance, and small molybdenum and vanadium additions (about 1%) that form stable carbides to increase resistance to erosive wear 8. Composition analysis was performed on H13 tool steel before and after spray forming. Results, summarized in Table 1, indicate no significant variation in alloy additions. Table 1. Composition of H13 tool steel Element C Mn Cr Mo V Si Fe Stock H13 0.41 0.39 5.15 1.41 0.9 1.06 Bal. Spray Formed H13 0.41 0.38 5.10 1.42 0.9 1.08 Bal. Microstructure The size, shape, type, and distribution of carbides found in H13 tool steel is dictated by the processing method and heat treatment. Normally the commercial steel is machined in the mill annealed condition and heat treated (austenitized/quenched/tempered) prior to use. It is typically austenitized at about 1010C, quenched in air or oil, and carefully tempered two or three times at 540 to 650C to obtain the required combination of hardness, thermal fatigue resistance, and toughness. Commercial, forged, ferritic tool steels cannot be precipitation hardened because after electroslag remelting at the steel mill, ingots are cast that cool slowly and form coarse carbides. In contrast, rapid solidification of H13 tool steel causes alloying additions to remain largely in solution and to be more uniformly distributed in the matrix 9-11. Properties can be tailored by artificial aging or conventional heat treatment. A benefit of artificial aging is that it bypasses the specific volume changes that occur during conventional heat treatment that can lead to tool distortion. These specific volume changes occur as the matrix phase transforms from ferrite to austenite to tempered martensite and must be accounted for in the original mold design. However, they cannot always be reliably predicted. Thin sections in the insert, which may be desirable from a design and production standpoint, are oftentimes not included as the material has a tendency to slump during austenitization or distort 8 during quenching. Tool distortion is not observed during artificial aging of spray-formed tool steels because there is no phase transformation. An optical photomicrograph of spray-formed H13 is shown in Figure 5 together with an SEM image, in backscattered electron (BSE) mode. Energy dispersive spectroscopic (EDS) composition analysis of some features in the photomicrographs is also given. While exact quantitative data is not possible due to sampling volume limitations, results suggest that grain boundaries are particularly rich in V. Intragranular (matrix) regions are homogeneous and rich in Fe. X-ray diffraction analysis indicates that the matrix phase is primarily ferrite (bainite) with very little retained austenite, and that the alloying elements are largely in solution. Discrete intragranular carbides are relatively rare, very small (about 0.1 m) and predominately vanadium-rich MC carbides. M 2 C carbides are not observed. Element Si V Cr Mn Mo Fe Spot #1 (wt%) 0.61 32.13 6.68 0.17 2.05 58.36 Spot #2 (wt%) 1.59 0.79 5.35 0.28 2.28 89.72 Figure 5. Photomicrographs of as-deposited H13 tool steel. 3% nital etch. (a) Optical photomicrograph. (b) SEM image (BSE mode) near a grain boundary. Table gives EDS composition of numbered features. 9 Figure 6 illustrates the microstructure of spray-formed H13 aged at 500C for 1 hr. During aging, grain boundaries remain well defined, perhaps coarsening slightly compared to as- deposited H13 (Figure 5). The most prominent change is the appearance of very fine (0.1 m diameter) vanadium-rich MC carbide precipitates. The precipitates are uniformly distributed throughout the matrix and increase the hardness and wear resistance of the tool steel. Increasing the soak temperature to 700C results in prominent carbide coarsening, the formation of M 7 C 3 and M 6 C carbides, and a decrease in hardness. The photomicrographs of Figure 7 illustrate the dramatic change in carbide size. BSE imaging clearly differentiates Mo/Cr-rich carbides from V-rich carbides, shown as light and dark areas, respectively, in Figure 7. EDS analysis of these carbides is also given in Figure 7. Element Si V Cr Mn Mo Fe Spot #1 (wt%) 0.06 13.80 7.20 2.64 2.44 73.86 Spot #2 (wt%) 1.52 0.82 5.48 0.23 2.38 89.57 Figure 6. Photomicrographs of spray-formed/aged H13 tool steel. 500C soak for 1 hr. 3% nital etch. (a) Optical photomicrograph. (b) SEM image (BSE mode) near a grain boundary. Table gives EDS composition of numbered features. 10 Element Si V Cr Mn Mo Fe Spot #1 (wt%) 0 82.27 9.01 0 4.33 4.39 Spot #2 (wt%) 0 5.30 25.70 0 55.55 13.45 Spot #3 (wt%) 1.60 0.88 6.32 0.28 2.92 88.00 Figure 7. SEM Photomicrograph (BSE mode) of spray-formed/aged H13 tool steel showing adjacent V-rich (dark) and Mo/Cr-rich (light) carbides. 700C soak for 1/2 hr, 3% nital etch. Table gives EDS composition of numbered features. Material Properties Porosity in spray-formed metals depends on processing conditions. The average as-deposited density of spray-formed H13 was 98-99% of theoretical, as measured by water displacement using Archimedes principle. As-deposited hardness was typically about 59 HRC, harder than commercial forged and heat treated material (28 to 53 HRC depending on tempering temperature), and significantly harder than annealed H13 (200 HB). The high hardness is attributable to lattice strain due to quenching stresses and supersaturation. As shown in Figure 8, hardness can be varied over a wide range by artificial aging. 59 HRC as- deposited samples were given isochronal (1 hr) soaks at 50C increments from 400 to 700C, air cooled, and evaluated for microhardness. At 400C, a small decrease in hardness was observed, presumably due to stress relieving. As the soak temperature was further increased, hardness rose to a peak hardness of approximately 62 HRC at 500C. Higher soak temperature resulted in a drop in hardness as carbide particles coarsened. Peak age hardness in spray-formed H13 tool steel is notably higher than that of commercial hardened material. Normally, commercial H13 dies used in die casting are tempered to about 40 to 45 HRC as a tradeoff since high hardness dies, while desirable for wear resistance, are prone to premature failure via thermal fatigue as the dies surface is rapidly cycled from 300C to 700C during aluminum production runs. 11 Figure 8. Hardness of artificially aged spray-formed H13 tool steel following one hour soaks at temperature. Hardness range of conventionally heat treated H13 included for comparison. As-deposited spray-formed material was also hardened following the conventional heat treatment cycle used with commercial material. Samples of forged/mill annealed commercial and spray- formed materials were austenitized at 1010C, air quenched, and double tempered (2 hr plus 2 hr) at (538C). The microstructure in both cases was found to be tempered martensite with a few spheroidal particles of alloy carbide. Hardness values for both materials were very nearly identical. Table 2 gives the ultimate tensile strength and yield strength of spray-formed, cast, and forged/heat treated H13 tool steel measured at test temperatures of 22 and 550C. Values for spray formed H13 are given in the as-deposited condition and following artificial aging and conventional heat treatments. Values for the spray-formed material are comparable to those of forged and are considerably higher than those of cast tool steel. The spray-formed material seems to retain its strength somewhat better than forged/heat treated H13 at higher temperatures. 12 Table 2. H13 tool steel mechanical properties. Sample/Heat Treatment Ultimate Tensile Strength (MPa) Yield Strength (MPa) Test Temperature (C) Spray formed/as-deposited 1061 951