電位器上蓋注塑模具設(shè)計(jì),電位器,注塑,模具設(shè)計(jì) 電位器上蓋注射模具設(shè)計(jì) 姓名 劉強(qiáng)班級(jí) 機(jī)制092班學(xué)號(hào) 20091031指導(dǎo)老師 蔡金平 摘要 產(chǎn)品分析注塑機(jī)的選擇模具成型零件設(shè)計(jì)模具整體設(shè)計(jì)工作過程模具的特點(diǎn) 一 產(chǎn)品分析 1 電位器上蓋 2 塑件的材料及性能 1 所設(shè)計(jì)的塑件的材料為ABS 該材料綜合性能好 沖擊強(qiáng)度高 尺寸穩(wěn)定 易于成型 2 成型性能吸濕大 必須充分干燥 模溫宜取60 80度 脫模后應(yīng)進(jìn)行調(diào)濕處理 3 產(chǎn)品要求1 由于產(chǎn)品內(nèi)表面有小凸臺(tái) 所以要有合理的出模方式 確保產(chǎn)品完整 2 要保證產(chǎn)品性能 尺寸精度以及互換性 4 解決方案 1 經(jīng)過查找資料后仔細(xì)計(jì)算得出 結(jié)合產(chǎn)品的材料及尺寸設(shè)計(jì) 符合強(qiáng)制脫模要求 故采取直接強(qiáng)制脫模方式出模 2 由于該塑件的質(zhì)量 31g 不大 采用一模一腔 由此保證產(chǎn)品的制造精度 二 選取注塑機(jī) 產(chǎn)品的質(zhì)量為31克 根據(jù)以下公式 選擇注射機(jī)的最大注射量 KG公 NG件 G廢式中K 0 8由于根據(jù)設(shè)計(jì)要求和加工的經(jīng)濟(jì)性取N 1 通過Proe得到G廢 4 62g得到G公 44 525 g 因此初選注塑量為100 3的注塑機(jī)SZ 100 80 三 模具成型零件設(shè)計(jì) 根據(jù)產(chǎn)品尺寸規(guī)格初選標(biāo)準(zhǔn)模架為300 250mm 2 型腔設(shè)計(jì) 1 型腔采用整體式優(yōu)點(diǎn) 牢固 不易變形不會(huì)使塑件產(chǎn)生拼接線痕跡易于保證型腔精度 1 型芯設(shè)計(jì) 1 型芯采用整體式優(yōu)點(diǎn) 加工效率高減少裝配難度可節(jié)約優(yōu)質(zhì)鋼材減少加工量 四 模具的整體設(shè)計(jì) 根據(jù)GB T12556 1 1990并結(jié)合塑件的具體情況選取其它結(jié)構(gòu)零件 最后得到如圖所示的模具 模擬開模演示 五 工作過程 1 模具的定模座板和動(dòng)模座板通過四個(gè)壓鐵分別裝在注塑機(jī)的定模板和動(dòng)模板上 2 模具閉模后 注塑機(jī)將塑料原料加熱到200 左右 再通過噴嘴注入模具型腔中 3 通過大約3s的保壓和25s的冷卻后開4 開模至限位螺釘起作用5 頂出塑件 手工取出凝料及產(chǎn)品6 合模 六 該模具的特點(diǎn) 1 該模具采用電火花和線切割加工成型零件 從而能保證精度要求 2 該模具采用二板式 單分型面 注射模 一摸一腔的簡單設(shè)計(jì) 3 無需側(cè)抽芯等較復(fù)雜設(shè)計(jì) 能實(shí)現(xiàn)快速出模 提高效率 謝謝各位老師 電位器上蓋注塑模具設(shè)計(jì) 目 錄 1 引言 4 2 塑件的成形工藝性分析 5 2 1 塑件材料的選擇及其結(jié)構(gòu)分析 5 2 2 ABS 塑料的材料特性 5 2 3 ABS 塑料的成型工藝參數(shù) 5 3 設(shè)計(jì)方案及參數(shù)的確定 7 3 1 注塑機(jī)的確定 7 3 2 澆注系統(tǒng)設(shè)計(jì) 9 3 2 1 主澆道設(shè)計(jì) 9 3 2 2 脫模方式的選擇 10 3 3 分型面的選擇 11 4 模具的結(jié)構(gòu)設(shè)計(jì) 12 4 1 成型零件的設(shè)計(jì) 12 4 2 模架的確定和標(biāo)準(zhǔn)件的選用 12 參考文獻(xiàn) 19 致謝 20 電位器上蓋注塑模具設(shè)計(jì) 2 摘要 通模具按制造的產(chǎn)品分類 可以分為塑料模具 又分為注塑模具 鑄壓模 具和吹塑模具 沖壓模具 鑄造模具 橡膠模具和玻璃模具等 其中 尤以注 塑模具和沖壓模具用途廣 技術(shù)成熟 占據(jù)的比重大 通過對(duì)電位器上蓋工藝 的正確分析 設(shè)計(jì)了一副一模一腔的塑料模具 詳細(xì)的敘述了模具成型零件包 括型腔 型芯等設(shè)計(jì) 重要零件的工藝參數(shù)的選擇與計(jì)算 澆注系統(tǒng) 冷卻系 統(tǒng)以及其它結(jié)構(gòu)的設(shè)計(jì)過程 模架的選擇原則 并利用 PRO E 中的 Plastic Advisor 塑料顧問 對(duì)設(shè)計(jì)完成的塑料模具進(jìn)行了塑料流動(dòng)分析 關(guān)鍵詞 電器支架 注塑模具 PRO E CAD 電位器上蓋注塑模具設(shè)計(jì) 3 Abstrac Through the mold by manufacturing the product category can be divided into plastic molds also divided into injection mold casting mold and blow mold stamping die die casting rubber molds and glass molds Among them especially in the injection mold and die stamping uses technology is mature occupy than a major Through the potentiometer to cover the correct analysis of the technology designed mold four cavity of the plastic mold A detailed description of the mold of molding parts includes a cavity core design an important part of the process parameter selection and calculation pouring system cooling system and other structural design process the choice of mold principle And the use of PRO E Plastic Advisor Plastic Advisor on the finished design plastic mold of plastic flow analysis Key words electric support of injection mould PRO E CAD 電位器上蓋注塑模具設(shè)計(jì) 4 1 引言 進(jìn)入工業(yè)社會(huì)以后 為了進(jìn)一步提高生產(chǎn)效率并保證規(guī)模化生產(chǎn) 模具被 越來越廣泛地應(yīng)用 模具工業(yè)是整個(gè)制造業(yè)發(fā)展的基礎(chǔ) 模具種類繁多 我們 日常樣生活中常見的各種物品以注塑模具生產(chǎn)出的居多 注塑模產(chǎn)品廣泛應(yīng)用 于機(jī)電 儀表 化工 汽車和航天航空等領(lǐng)域 模具工業(yè)呈現(xiàn)了單件多品種 產(chǎn)品結(jié)構(gòu)復(fù)雜 產(chǎn)品模型變更頻繁 加工精度要求高 設(shè)計(jì)制造周期短等特點(diǎn) 傳統(tǒng)的設(shè)計(jì)制造方法和理念已經(jīng)不能滿足模具工業(yè)發(fā)展的需求 進(jìn)入 20 世紀(jì) 80 年代以來得益于計(jì)算機(jī)輔助設(shè)計(jì)技術(shù)的發(fā)展 這一問題已得到了妥善解決 目前 國內(nèi)注塑模具設(shè)計(jì)業(yè)內(nèi)應(yīng)用比較廣 泛的兩款設(shè)計(jì)軟件為 Pro E 和 UG 美國的 EDS 公司針對(duì)注射模具設(shè) 計(jì)推出了注射模設(shè)計(jì)向?qū)?Mold wizard 模 塊 該模塊無縫地集成于三 維機(jī)械 CAD CAE CAM 系統(tǒng)中 為用戶提供了注射 模設(shè)計(jì)的環(huán)境和工具 封裝了模具設(shè)計(jì)的專家知識(shí) 提供了豐富的標(biāo)準(zhǔn)化的模 架庫 零件庫和嵌件庫 電位器上蓋注塑模具設(shè)計(jì) 5 2 塑件的成形工藝性分析 2 1 塑件材料的選擇及其結(jié)構(gòu)分析 1 塑件模型圖 圖 1 電位器上蓋 該制品的材料為 ABS ABS 樹脂為微黃色或白色不透明顆粒料 無毒無味 是丙烯腈丁 丁二烯 苯乙烯共聚物 丙烯腈使聚合物耐油 耐熱 耐化學(xué)腐蝕 丁二烯使聚合物具有卓越的柔性 韌性 苯乙烯賦以聚合物良好的剛性和加工 流動(dòng)性 因此 ABS 樹脂具有突出的力學(xué)性能和良好的綜合性能 ABS 塑料的表 面可以電鍍 但它的使用溫度不高 不超過 80 C ABS 塑料廣泛用于制造汽車內(nèi)飾件 電器外殼 手機(jī) 電話外殼 旋鈕 儀表盤 容器蓋 也可以生產(chǎn)板材 管材等產(chǎn)品 2 2 ABS 塑料的材料特性 1 使用 ABS 塑料成型塑件時(shí) 由于溶體的黏度值較高 注射成形的壓力 值高 所以塑件對(duì)型芯的包緊力較大 為便脫模 塑件應(yīng)采用較大的脫模斜度 2 ABS 塑料的溶體黏度高 制品易產(chǎn)生熔接痕 設(shè)計(jì)模具時(shí)應(yīng)減少澆注 系統(tǒng)對(duì)料流的阻力 流道長度短一些 3 ABS 塑料吸濕性強(qiáng) 易吸水 成型前應(yīng)進(jìn)行干燥處理 4 在正常成型條件下 ABS 塑件的尺寸穩(wěn)定性好 2 3 ABS 塑料的成型工藝參數(shù) 電位器上蓋注塑模具設(shè)計(jì) 6 表 1 ABS 塑料成型工藝參數(shù) 參數(shù) 取值范圍 選取數(shù)值 密度 1 02 1 05g cm 1 03g cm 收縮率 S 0 3 0 8 0 5 噴嘴 180 190 180 料筒 210 230 220溫度 模具 50 70 60 注射 70 90 80 壓力 MPa 保壓 50 70 60 注射 3 5 3 保壓 15 30 20 冷卻 15 30 25 時(shí)間 S 總計(jì) 40 70 48 電位器上蓋注塑模具設(shè)計(jì) 7 3 設(shè)計(jì)方案及參數(shù)的確定 3 1 注塑機(jī)的確定 該產(chǎn)品的材料為 ABS 查手冊可知其密度 03 1 3 7 cmg 收縮率為 0 4 0 7 計(jì)算出其平均密度為 5 cg 平均收縮率為 0 55 1 注射量的校核 注射機(jī)一個(gè)注射周期內(nèi)所需注射量的塑料熔體的總量必須在注射機(jī)額定注 射量的 80 以內(nèi) 在一個(gè)注射成形周期內(nèi) 需注射入模具內(nèi)的塑料熔體的容量或質(zhì)量 應(yīng)為制件 和澆注系統(tǒng)兩部份容量或質(zhì)量之和 即 V nVz Vj 或 M nmz mj 式中 V m 一個(gè)成形周期內(nèi)所需射入的塑料容積或質(zhì)量 cm 或 g n 型腔數(shù)目 Vz mz 單個(gè)塑件的容量或質(zhì)量 cm 或 g Vj mj 澆注系統(tǒng)凝料和飛邊所需塑料的容量或質(zhì)量 cm 或 g 故應(yīng)使 nVz Vj 0 8Vg 或 nmz mj 0 8mg 式中 Vg mg 注射機(jī)額定注射量 cm 或 g 根據(jù)容積計(jì)算 1 主流道的體積約為 V cm 3 14 0 62 5 8 2 該模具總共需填充塑件的體積約為 V cm 19 21 8 27 21 nVz Vj 27 21 0 8Vg 可見注射機(jī)的注射量符合要求 2 型腔數(shù)量的確定和校核 型腔數(shù)量與注射機(jī)的塑化率 最大注射量及鎖模力等參數(shù)有關(guān) 此外 還受塑 件的精度和生產(chǎn)的經(jīng)濟(jì)性等因數(shù)影響 可根據(jù)注射機(jī)的最大注射量確定型腔數(shù) n 12mKN 電位器上蓋注塑模具設(shè)計(jì) 8 式中 K 注射機(jī)的最大注射量的得用系數(shù) 一般取 0 8 mN 注射機(jī)允許的最大注射量 m 2 澆注系統(tǒng)所需塑料的質(zhì)量或體積 g 或 cm m 1 單個(gè)塑件的質(zhì)量或體積 g 或 cm 所以需要 8942 3683 08 n n 1 符合要求 3 塑件在分型面上的投影面積與鎖模力校核 注射成型時(shí) 塑件在模具分型面上的投影面積是影響鎖模力的主要因素 其數(shù) 值越大 需要的鎖模力也就越大 如果這一數(shù)值超過了注射機(jī)允許使用的最大 成型面積 則成型過程中將會(huì)出現(xiàn)溢漏現(xiàn)象 因此 設(shè)計(jì)注射模時(shí)必須滿足下 面關(guān)系 nA1 A2 A 式中 A 注射機(jī)允許使用的最大成型面積 mm2 其他符號(hào)意義同前 注射成型時(shí) 模具所需的鎖模力與塑件在水平分型面上的投影面積有關(guān) 為了 可靠地鎖模 不使成型過程中出現(xiàn)溢漏現(xiàn)象 應(yīng)使塑料熔體對(duì)型腔的成型壓力 與塑件和澆注系統(tǒng)在分型面上的投影面積之和的乘積小于注射機(jī)額定鎖模力 即 nA1 A2 p F 式中符號(hào)意義同前 所以需要 2 40 95 9 80 75600 A 查得 ABS 的平均成型壓力為 30 cm2 MPa 0 2 4 7 0 6 8 30 3 52 30 10 56 F 符合要求 4 最大注射壓力校核 注射機(jī)的額定注射壓力即為它的最高壓力 pmax 應(yīng)該大于注射機(jī)成型時(shí)所調(diào)用 的注射壓力 即 pmax Kp0 很明顯 上式成立 符合要求 5 模具與注射機(jī)安裝部份的校核 噴嘴尺寸 注射機(jī)頭為球面 其球面半徑與相應(yīng)接觸的模具主流道始端凹下 的球面半徑相適應(yīng) 模具厚度 模具厚度 H 又稱閉合高度 必須滿足 Hmin H Hmax 式中 Hmin 注射機(jī)允許的最小厚度 即動(dòng) 定模板之間的最小開距 Hmax 注射機(jī)允許的最大模厚 注射機(jī)允許厚度 150 H 250 電位器上蓋注塑模具設(shè)計(jì) 9 符合要求 6 開模行程校核 開模行程 s 合模行程 指模具開合過程中動(dòng)模固定板的移動(dòng)距離 注射機(jī)的 最大開模行程與模具厚度無關(guān) 對(duì)于單分型面注射模 Smax s H1 H2 5 10mm 式中 H1 摧出距離 脫模距離 mm H2 包括澆注系統(tǒng)凝料在內(nèi)的塑件高度 mm 開模距離取 H1 50 包括澆注系統(tǒng)凝料在內(nèi)的塑件高度取 H2 20 余量取 8 則有 Smax s 50 20 28 98 符合要求 3 2 澆注系統(tǒng)設(shè)計(jì) 澆注系統(tǒng)是塑料熔體自注射機(jī)的噴嘴射出后 到進(jìn)入模具型腔以前所流經(jīng) 的一段路程的總稱 普通澆注系統(tǒng)由主流道 分流道 冷料穴和澆口組成 澆注系統(tǒng)的設(shè)計(jì)原則 1 型腔的布置和澆口開設(shè)部位力求對(duì)稱 防止模具承受偏載而產(chǎn)生溢料現(xiàn)象 2 能短 斷面尺寸適當(dāng) 盡可能減少彎折 表面粗糙度要低 以使熱量及壓 力損失盡可能小 3 對(duì)多型腔應(yīng)盡可能使塑料熔體在同一時(shí)間內(nèi)進(jìn)入各個(gè)型腔的深處及角落 即分流道盡可能采用平衡式布置 4 滿足型腔充滿的前提下 澆注系統(tǒng)容積盡可能小 以減小塑料的耗量 5 澆品位置要適當(dāng) 盡量避免沖擊嵌件和細(xì)小的型芯 防止型芯變形 澆 口的殘痕不應(yīng)影響塑件的外觀 由于設(shè)計(jì)的是一摸一腔的簡單模具 所以這里采用直澆口設(shè)計(jì) 3 2 1 主澆道設(shè)計(jì) 主澆道是塑料熔體進(jìn)入模具型腔時(shí)最先經(jīng)過的部位 它將注塑機(jī)噴嘴注出 的塑料熔體導(dǎo)入分流道或型腔 其尺寸直接影響到塑料熔體的流動(dòng)速度和充模 時(shí)間 由于主流道要與高溫塑料和注塑機(jī)噴嘴反復(fù)接觸和碰撞 通常不直接開 在定模板上 而是將它單獨(dú)設(shè)計(jì)成主流道襯套鑲?cè)攵０鍍?nèi) 澆口套的設(shè)計(jì)如果 電位器上蓋注塑模具設(shè)計(jì) 10 圖 2 主流道襯套 3 2 2 脫模方式的選擇 由于制件內(nèi)表面有伸出材料 小凸臺(tái) 本著簡便快速的設(shè)計(jì)理念 首先考 慮是不是能夠強(qiáng)行脫模 圖 3 加工零件 圖 4 強(qiáng)制脫模示意圖 塑件的內(nèi)外側(cè)凹陷較淺 同事成型塑件為聚乙烯 聚苯乙烯 聚甲醛這類 任帶有足夠彈性的塑件 為使脫模是的脫模阻力不要太大引起塑件損壞和變形 塑件側(cè)凹深度必須在要求的合理范圍內(nèi) 見下面的公式說明 同事還要重視將 凹凸起伏處設(shè)計(jì)為圓角或斜面過度結(jié)構(gòu) A B 100 B 5 A 96 33 B 94 6078 所以 96 33 94 6078 100 94 6078 1 82 5 符合強(qiáng)制脫模要求 電位器上蓋注塑模具設(shè)計(jì) 11 3 3 分型面的選擇 塑料在模具型腔凝固形成塑件 為了將塑件取出來 必須交模具型腔打開 也就是必須將模具分成兩部分 即定模和動(dòng)模兩大部分 定模和動(dòng)模相接角的 面稱為分型面 分型面的選擇好壞對(duì)塑件質(zhì)量 操作難易 模具結(jié)構(gòu)及制造都有很大的影 響 通常遵循以下原則 1 分型面不僅應(yīng)選擇在制品外觀沒有影響的位置 而且還必須考慮如何能比 較方便的清除分型而產(chǎn)生地溢料飛邊 同時(shí) 還應(yīng)避免分型而產(chǎn)生飛邊 分型 面一般選擇在塑件的尺寸的最大處 2 分型面的選擇應(yīng)有利于制品脫模 否則 模具結(jié)構(gòu)便會(huì)變得比較復(fù)雜 通 常分型面的選擇應(yīng)盡可能使制品在開模厚滯留在動(dòng)模一側(cè) 3 分型面不影響制品的形狀和尺寸精度 4 分型面應(yīng)盡量與最后填充溶體的型腔表面重合 以利于排氣 5 選擇分型面時(shí) 應(yīng)盡量減少脫模斜度給制品大小端尺寸帶來的差異 6 分型面的選擇應(yīng)便于模具加工 為了便于模具加工制造 應(yīng)盡量選擇平直 分型面或易于加工的分型面 7 選擇分型面時(shí) 應(yīng)盡量減少制品在分型面上的投影面積 以防止面積過大 造成鎖模困難 產(chǎn)生嚴(yán)重溢料 8 有側(cè)孔或側(cè)凹的制品 選擇分型面時(shí)應(yīng)自首先考慮將抽心或分型面距離長 的一邊放在動(dòng) 定模的方向 而將短的一邊作為側(cè)向分型抽心機(jī)構(gòu)時(shí) 除水液 壓抽心能獲得較大的側(cè)向抽拔距離外 一般分型抽心機(jī)構(gòu)側(cè)向抽拔距離都較小 綜上因素 選擇塑件尺寸的最大處為主分型面 圖 5 分型面 電位器上蓋注塑模具設(shè)計(jì) 12 4 模具的結(jié)構(gòu)設(shè)計(jì) 4 1 成型零件的設(shè)計(jì) 成型零件是直接與塑料接觸構(gòu)成塑件形狀的零件 其中構(gòu)成塑件外形的成 型零件稱為凹模 構(gòu)成塑件內(nèi)部形狀的成型零件稱為凸模 或型芯 由于凹 凸模件直接與高溫 高壓的塑料接觸 并且脫模時(shí)反復(fù)與塑件摩擦 因此 要 求凹 凸模件具有足夠的強(qiáng)度 剛度 硬度 耐磨性 耐腐蝕性以及足夠低的 表面粗糙度 如果凹 凸模都采用整體式 優(yōu)點(diǎn)是加工成本低 但是常用模架 的模板材料為普通的中碳鋼 用作凹 凸模 使用壽命短 若選用好材料的模 板制作整體的凹 凸模 則制造成本較高 綜合考慮以上的因素 凹 凸模都 采用整體嵌入式 這樣既保證了模具的使用壽命 又不浪費(fèi)價(jià)格昂貴的材料 并且損壞后 維修 更換方便 4 2 模架的確定和標(biāo)準(zhǔn)件的選用 模架尺寸確定之后 對(duì)模具有關(guān)零件要進(jìn)行必要的強(qiáng)度或剛度計(jì)算 以校 核所選模架是否適當(dāng) 尤其時(shí)對(duì)大型模具 這一點(diǎn)尤為重要 標(biāo)準(zhǔn)件包括通用標(biāo)準(zhǔn)件及模具專用標(biāo)準(zhǔn)件兩大類 通用標(biāo)準(zhǔn)件如緊固件等 模 具專用標(biāo)準(zhǔn)件如定位圈 澆口套 推桿 推管 導(dǎo)柱 導(dǎo)套 模具專用彈簧 冷卻及加熱元件 順序分型機(jī)構(gòu)及精密定位用標(biāo)準(zhǔn)組件等 由前面型腔的布局以及相互的位置尺寸 再結(jié)合標(biāo)準(zhǔn)模架 可選用標(biāo)準(zhǔn)模 架 350 L 其中 L 取 350mm 可符合要求 模架上要有統(tǒng)一的基準(zhǔn) 所有零件的基準(zhǔn)應(yīng)從這個(gè)基準(zhǔn)推出 并在模具上 打出相應(yīng)的基準(zhǔn)標(biāo)記 一般定模座板與定模固定板要用銷釘定位 動(dòng) 定模固 定板之間通過導(dǎo)向零件定位 脫出固定板通過導(dǎo)向零件與動(dòng)?；蚨９潭ò宥?位 模具通過澆注套定位圈與注射機(jī)的中心定位孔定位 動(dòng)模墊板與動(dòng)模固定 板不需要銷釘精確定位 墊快不需要與動(dòng)模固定板用銷釘精確定位 頂出墊板 不需與頂出固定板用銷釘精確定位 模具上所有的螺釘盡量采用內(nèi)六角螺釘 模具外表面盡量不要有突出部分 模具外表面應(yīng)光潔 加涂防銹油 兩模板之間應(yīng)有分模隙 即在裝配 調(diào)試 維修過程中 可以方便地分開 兩塊模板 一 定模固定板 定模座板 300 250 厚 25mm 主流道襯套固定孔與其為 H7 m6 過渡配合 通過 4 個(gè) 10 的內(nèi)六角螺釘與定模固定板連接 定模墊板通常就是模具與注射機(jī)連接處的定模板 電位器上蓋注塑模具設(shè)計(jì) 13 圖 6 定模座板 二 定模板 250 250 厚 60mm 其導(dǎo)柱固定孔與導(dǎo)柱為 H7 m6 過渡配 圖 7 定模固定板 電位器上蓋注塑模具設(shè)計(jì) 14 三 動(dòng)模板 250 250 厚 30mm 其注射機(jī)頂桿孔為 40mm 其上的推板導(dǎo)柱孔與導(dǎo)柱采用 H7 m6 配合 圖 8 動(dòng)模固定板 四 支撐板 250 250 厚 35mm 其注射機(jī)頂桿孔為 40mm 其上的推板導(dǎo)柱孔與導(dǎo)柱采用 H7 m6 配合 圖 9 支撐板 電位器上蓋注塑模具設(shè)計(jì) 15 五 墊塊 48 250 2 厚 60mm 1 主要作用 在動(dòng)模座板與動(dòng)模墊板之間形成頂出機(jī)構(gòu)的動(dòng)作空間 或是 調(diào)節(jié)模具的總厚度 以適應(yīng)注射機(jī)的模具安裝厚度要求 2 結(jié)構(gòu)型式 可為平行墊塊 拐角墊塊 該模具采用平行墊塊 3 墊塊一般用中碳鋼制造 也可用 Q235A 制造 或用 HT200 球墨鑄鐵等 4 模具組裝時(shí) 應(yīng)注意左右兩墊塊高度一致 否則由于負(fù)荷不均勻會(huì)造成 動(dòng)模板損壞 圖 10 墊塊 六 推桿固定板 150 250 厚 15mm 固定推桿 電位器上蓋注塑模具設(shè)計(jì) 16 圖 11 推桿固定板 電位器上蓋注塑模具設(shè)計(jì) 17 七 推板 150 250 厚 20mm 圖 12 推桿支撐板 八 動(dòng)模固定板 300 250 厚 25mm 圖 13 動(dòng)模座板 電位器上蓋注塑模具設(shè)計(jì) 18 九 模具的整體設(shè)計(jì) 圖 14 模架整體 為了保證塑件的質(zhì)量與模具的壽命要求 各組成部分應(yīng)滿足以下技術(shù)要求 成型部位及分型面 型面粗糙度及尺寸形狀 型腔與型空間尺寸 脫模斜度必須 達(dá)到設(shè)計(jì)的要求 分型面光滑平整 棱邊清晰 鑲件組合等符 合質(zhì)量要求 固定結(jié)合部分配合嚴(yán)密 不得有間隙 凹凸模組 合后應(yīng)保持間隙一致 塑件同一表面由上下?；騼砂肽３尚?時(shí)錯(cuò)位應(yīng)在允許的范圍內(nèi) 頂出系統(tǒng) 頂出時(shí)動(dòng)作靈活輕松 頂出行程滿足要求 各頂出件無晃動(dòng) 竄動(dòng) 頂出 桿等在塑件上殘留的痕跡應(yīng)在塑件要求范圍內(nèi) 一般允許高出型面 0 1mm 復(fù)位可靠正確 復(fù)位桿卅復(fù)位系統(tǒng)裝配正確 一般應(yīng)低于型面 0 02 0 05mm 導(dǎo)向系統(tǒng) 導(dǎo)柱 導(dǎo)套垂直度為 100mm 0 02mm 導(dǎo)套內(nèi)外孔同軸度 0 01mm 滑動(dòng)靈 活 無松動(dòng)及吸死現(xiàn)象 保證導(dǎo)向部位和各零件相對(duì)位置 導(dǎo)柱 導(dǎo)套 電位器上蓋注塑模具設(shè)計(jì) 19 軸線對(duì)模板垂直度公差為 100mm 0 02mm 澆注系統(tǒng) 主澆道 分澆道 進(jìn)料口的尺寸 形狀 糙度等均應(yīng)符合要求 流道平 直 圓滑連接 無死角 縫隙 坑 澆口套的主流道 加工粗糙度 加工痕 跡應(yīng)有利于塑料流動(dòng)及澆注系統(tǒng)脫模 不得有與注射橫噴嘴 R 吻合的 側(cè)坑 進(jìn)料端口孔不得有影響脫模的倒錐 模具各零部件的加工應(yīng)保證精度要求 導(dǎo)柱 導(dǎo)套應(yīng)保證同軸度要求 加工導(dǎo) 柱 導(dǎo)套孔時(shí)應(yīng)同時(shí)加工 以保證同軸度要求 其它有同軸度要求的孔都采用同時(shí) 加工的方法 模具在裝配時(shí)應(yīng)保證各零件的準(zhǔn)確位置精度 模具上 下平面的平行度誤差 不大于 0 05mm 相鄰零件或相鄰單元之間的配合與連接均需按裝配工藝確定的 裝配基準(zhǔn)進(jìn)行定位與固定 以保證其間的配合精度和位置精度 電位器上蓋注塑模具設(shè)計(jì) 20 參考文獻(xiàn) 1 何銘新 錢可強(qiáng) 機(jī)械制圖 北京 高等教育出版社 2004 2 屈華昌 塑料成型工藝與模具設(shè)計(jì) 北京 機(jī)械工業(yè)出版社 1996 3 申樹義 高濟(jì) 塑料模具設(shè)計(jì) 北京 機(jī)械工業(yè)出版社 2002 4 蔣曉 Auto CAD 2008 中文版機(jī)械設(shè)計(jì)標(biāo)準(zhǔn)視力教程 北京 清華大學(xué)出版社 2008 5 馮炳亮 模具設(shè)計(jì)與制造簡明手冊 上海 上?？茖W(xué)技術(shù)出版社 2002 6 廖念釗 互換性與技術(shù)測量 北京 中國計(jì)量出版社 1994 7 唐深玉 擠出模與塑料模設(shè)計(jì)優(yōu)化手冊 北京 機(jī)械工業(yè)出版社 1996 8 陳錫棟 周小玉 實(shí)用模具技術(shù)手冊 北京 機(jī)械工業(yè)出版社 2002 9 付麗 張秀棉 塑料模具技術(shù)制造于應(yīng)用實(shí)例 北京 機(jī)械工業(yè)出版社 2002 10 余桂英 郭紀(jì)林 AutoCAD2006 基礎(chǔ)實(shí)用教程 大連 大連理工出版社 2003 11 楊明忠 朱家誠 機(jī)械設(shè)計(jì) 武漢 武漢理工大學(xué)出版社 2002 12 曾志新 呂明 機(jī)械制造技術(shù)基礎(chǔ) 武漢 武漢理工大學(xué)出版社 2005 13 王先奎 機(jī)械制造工藝學(xué) 上海 上海交通大學(xué)出版社 2004 14 譚建榮 張樹有 圖學(xué)基礎(chǔ)教程 北京 高等教育出版社 1999 15 丁淑輝 Pro ENGINEER Wildfire5 0 基礎(chǔ)設(shè)計(jì)與實(shí)現(xiàn) 北京 清華大學(xué)出版社 2010 16 夏巨諶 李志剛 中國模具設(shè)計(jì)大典 電子版 中國機(jī)械工程學(xué)會(huì) 17 孫玉芹 孟兆新 機(jī)械精度設(shè)計(jì)基礎(chǔ) 科學(xué)出版社 2003 18 塑料模具設(shè)計(jì)手冊 編委會(huì) 塑料模具技術(shù)手冊 北京 機(jī)械工業(yè)出版社 2001 電位器上蓋注塑模具設(shè)計(jì) 21 致謝 本論文是在尊敬的導(dǎo)師蔡金平講師親切的關(guān)懷和精心的指導(dǎo)下完成的 他 工作態(tài)度嚴(yán)謹(jǐn) 有高度的責(zé)任心 不僅給我們提供了大量的參考資料 還孜孜 不倦的指導(dǎo)我們 使得我們能順利的完成設(shè)計(jì)任務(wù) 他的工作作風(fēng)更是我們學(xué) 習(xí)的榜樣 值此學(xué)位論文完成之際 謹(jǐn)向指導(dǎo)老師表示衷心的感謝 并致以崇 高的敬意 并在此對(duì)系里其他對(duì)本設(shè)計(jì)提出寶貴意見的老師以及同學(xué)和評(píng)審老師表示 感謝 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 party s 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 kmm4 inel 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 deposit s 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 100 C 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 700 C and air cooled Conventionally heat treated H13 was austenitized at 1010 C for 30 min air quenched and double tempered 2 hr plus 2 hr at 538 C 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 code s 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 1010 C quenched in air or oil and carefully tempered two or three times at 540 to 650 C 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 500 C 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 700 C 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 500 C 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 700 C 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 50 C increments from 400 to 700 C air cooled and evaluated for microhardness At 400 C 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 500 C 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 die s surface is rapidly cycled from 300 C to 700 C 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 1010 C air quenched and double tempered 2 hr plus 2 hr at 538 C 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 550 C 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 22 Spray formed aged at 540 C 1964 1881 22 Spray formed aged at 540 C 1647 1475 550 Spray formed conventional heat treatment 1358 1158 22 Cast 600 22 Cast conventional heat treatment 882 22 Commercial forged heat treated 1799 1681 22 Commercial forged heat treated 1323 1247 550 austenitized at 1010 C double tempered 2hr 2hr at 590 C no yield at 0 2 offset Summary Spray forming is a robust rapid tooling technology that allows tool steel molds and di