數(shù)控機(jī)床自動(dòng)夾持搬運(yùn)裝置的液壓系統(tǒng)設(shè)計(jì)
數(shù)控機(jī)床自動(dòng)夾持搬運(yùn)裝置的液壓系統(tǒng)設(shè)計(jì),數(shù)控機(jī)床自動(dòng)夾持搬運(yùn)裝置的液壓系統(tǒng)設(shè)計(jì),數(shù)控機(jī)床,自動(dòng),夾持,搬運(yùn),裝置,液壓,系統(tǒng),設(shè)計(jì)
畢業(yè)設(shè)計(jì)（論文）任務(wù)書年 月 日畢業(yè)設(shè)計(jì)（論文）題 目題目來源指導(dǎo)教師職稱所在部門學(xué)生姓名學(xué)號(hào)班 級(jí)所屬院系專業(yè)外語翻譯要求課題需要完成的任務(wù)【工程設(shè)計(jì)類課題：】明確設(shè)計(jì)具體任務(wù)，設(shè)計(jì)原始條件及主要技術(shù)指標(biāo)；設(shè)計(jì)方案的形成（比較與論證）；該學(xué)生的側(cè)重點(diǎn)；應(yīng)完成的工作量（論文、圖紙、及計(jì)算機(jī)應(yīng)用要求等）【軟件開發(fā)類課題：】明確軟件開發(fā)的具體任務(wù)；弄清系統(tǒng)的現(xiàn)狀及其發(fā)展趨勢(shì)；建立仿真模型；編寫計(jì)算機(jī)程序；上機(jī)調(diào)試與結(jié)果分析；應(yīng)完成的工作量（論文、程序等）【畢業(yè)論文類：】明確課題的任務(wù)、方向、研究范圍和目標(biāo)、開展調(diào)研、查閱文獻(xiàn)、收集資料并整理分析，了解相關(guān)的研究歷史和研究現(xiàn)狀，應(yīng)完成的工作量（論文文獻(xiàn)評(píng)述等）【實(shí)驗(yàn)研究類課題：】明確課題來源，具體任務(wù)與目標(biāo)，國內(nèi)外相關(guān)的研究現(xiàn)狀及其評(píng)述；該學(xué)生的研究重點(diǎn)；研究的實(shí)驗(yàn)內(nèi)容、實(shí)驗(yàn)原理及試驗(yàn)方案；計(jì)算機(jī)應(yīng)用及工作量要求（論文、文獻(xiàn)綜述報(bào)告等）課題計(jì) 劃 安 排序號(hào)內(nèi) 容時(shí) 間 安 排計(jì)劃答辯時(shí)間答辯提交資料教研室主任審核意見簽名： 畢業(yè)設(shè)計(jì)（論文）中文摘要數(shù)控機(jī)床自動(dòng)夾持搬運(yùn)裝置的液壓系統(tǒng)設(shè)計(jì)摘 要：數(shù)控機(jī)床上專用于工件和零件的夾持和自動(dòng)運(yùn)轉(zhuǎn)的裝置，其運(yùn)動(dòng)自由度多，且有嚴(yán)格的動(dòng)作順序要求。用液壓驅(qū)動(dòng)可實(shí)現(xiàn)動(dòng)作自動(dòng)循環(huán)，利于自動(dòng)化和高效率等要求。機(jī)械手用于各種工藝裝備上，其中包括組成柔性自動(dòng)化系統(tǒng)的數(shù)控金屬切削機(jī)床。工業(yè)機(jī)器人裝備有自動(dòng)可換夾持裝置，其中雙夾持器的裝置用來保證同時(shí)操作毛坯和在加工的零件。本設(shè)計(jì)主要針對(duì)機(jī)械手的液壓系統(tǒng)，確定液壓系統(tǒng)中各個(gè)部分的功能，并且對(duì)各種執(zhí)行元件進(jìn)行計(jì)算分析，最終完成液壓原理圖。關(guān)鍵詞：可換夾持裝置 液壓元件 雙夾持器畢業(yè)設(shè)計(jì)（論文）外文摘要Numerically Controlled Machine Tools Automatically Handling Devices Hydraulic Rescue System DesignAbstract: Numerically controlled machine tools, spare parts and dedicated to her rescue and automatic operation of the device, the more freedom of movement and strict action sequence. Driven by hydraulic achievable moves automatically cycle for automation and high efficiency. Mechanical hand for various processes and equipment, including the digital automation system composed soft metal cutting machine tools. Industrial robots are equipped with automatic convertible rescue devices, including devices used to ensure that double-rescue devices at the same time and in the processing operation blank parts. The design of the hydraulic system mainly mechanical hand, identifying the functions of the various parts of the hydraulic system, and implementation of various components in the calculation of analysis, and ultimately complete hydraulic principles maps.Keywords: Convertible rescue devices ; Hydraulic components; Double-rescue vehicles目 錄1 概述 11.1課題背景 11.2課題內(nèi)容 11.3課題的意義 21.4課題的創(chuàng)新點(diǎn) 22 機(jī)械手的功能設(shè)計(jì) 22.1機(jī)械手液壓系統(tǒng)的各部分功能 22.2 機(jī)械手液壓系統(tǒng)的功能綜合52.3機(jī)械手電磁鐵動(dòng)作循環(huán)表 62.4 機(jī)械手液壓系統(tǒng)方案設(shè)計(jì) 63 機(jī)械手液壓系統(tǒng)機(jī)構(gòu)設(shè)計(jì)計(jì)算 63.1負(fù)載分析 63.2 液壓馬達(dá)的負(fù)載93.3 執(zhí)行元件主要參數(shù)的確定103.4 計(jì)算液壓缸各工作階段的工作壓力、流量、功率113.5 擬定液壓原理圖113.6選擇液壓元件123.7液壓缸基本參數(shù)的確定143.8液壓缸結(jié)構(gòu)強(qiáng)度計(jì)算和穩(wěn)定校驗(yàn)173.9液壓傳動(dòng)用油的選擇224 驗(yàn)算系統(tǒng)液壓性能234.1壓力損失的驗(yàn)算及泵壓力的調(diào)整234.2液壓系統(tǒng)發(fā)熱和溫升驗(yàn)算264.3濾油器的選擇26結(jié)論 30致謝 31參考文獻(xiàn)321概述11 課題背景 現(xiàn)在工業(yè)機(jī)器人集機(jī)械、電子、控制、計(jì)算機(jī)、傳感器、人工智能等多學(xué)科先進(jìn)技術(shù)于一體的現(xiàn)代制造業(yè)重要的自動(dòng)化裝備。自從1962年美國研制出世界上第一臺(tái)工業(yè)機(jī)器人以來，機(jī)器人技術(shù)極其產(chǎn)品發(fā)展很快，已成為柔性制造系統(tǒng)（FMS）、自動(dòng)化工廠（FA）、計(jì)算機(jī)集成制造系統(tǒng)（CIMS）的自動(dòng)化工具。廣泛采用工業(yè)機(jī)器人，不僅可提高產(chǎn)品的質(zhì)量與產(chǎn)量，而且對(duì)保障人身安全，改善勞動(dòng)環(huán)境，減輕勞動(dòng)強(qiáng)度，提高勞動(dòng)生產(chǎn)率，節(jié)約原材料以及降低生產(chǎn)成本，有著十分重要的意義。和計(jì)算機(jī)、網(wǎng)絡(luò)技術(shù)一樣，工業(yè)機(jī)器人的廣泛應(yīng)用正在日益改善著人類的生產(chǎn)和生活方式。工業(yè)機(jī)器人是最典型的機(jī)電一體化數(shù)字化裝備，技術(shù)附加值很高，應(yīng)用范圍很廣，作為先進(jìn)制造業(yè)的支撐技術(shù)和信息化社會(huì)的新興產(chǎn)業(yè)，將對(duì)未來生產(chǎn)和社會(huì)發(fā)展起著越來越重要的作用。國外專家預(yù)測(cè)，機(jī)器人產(chǎn)業(yè)是繼汽車、計(jì)算機(jī)之后出現(xiàn)的一種新的大型高技術(shù)產(chǎn)業(yè)。據(jù)聯(lián)合國歐洲委員會(huì)（UNECE）和國際機(jī)器人聯(lián)合會(huì)（IFR）的統(tǒng)計(jì)，世界機(jī)器人市場前景看好，從20世紀(jì)下半葉起，世界機(jī)器人產(chǎn)業(yè)一直保持著穩(wěn)步增長的良好勢(shì)頭。進(jìn)入20世紀(jì)90年代，機(jī)器人產(chǎn)品發(fā)展速度較快，年增長率平均在10%左右。2004年增長率達(dá)到闖記錄的20%。其中，亞洲機(jī)器人增長幅度最為突出，高達(dá)43%。在自動(dòng)化生產(chǎn)領(lǐng)域中，工業(yè)機(jī)械手是近幾十年發(fā)展起來的。工業(yè)機(jī)械手的是從工業(yè)機(jī)器人中分支出來的。 其特點(diǎn)是可通過編程來完成各種預(yù)期的作業(yè)任務(wù)，在構(gòu)造和性能上兼有人和機(jī)器各自的優(yōu)點(diǎn)，尤其體現(xiàn)了人的智能和適應(yīng)性。機(jī)械手作業(yè)具有準(zhǔn)確性和各種環(huán)境中完成作業(yè)的能力。 機(jī)械手是一種能自動(dòng)化定位控制并可重新編程序以變動(dòng)的多功能機(jī)器，它有多個(gè)自由度，可用來搬運(yùn)物體以完成在各個(gè)不同環(huán)境中工作。 機(jī)械手由執(zhí)行機(jī)構(gòu)、驅(qū)動(dòng)-傳動(dòng)機(jī)構(gòu)、控制系統(tǒng)、智能系統(tǒng)、遠(yuǎn)程診斷監(jiān)控系統(tǒng)五部分組成。驅(qū)動(dòng)-傳動(dòng)機(jī)構(gòu)與執(zhí)行機(jī)構(gòu)是相輔相成的，在驅(qū)動(dòng)系統(tǒng)中可以分：機(jī)械式、電氣式、液壓式和復(fù)合式，其中液壓操作力最大。本課題是數(shù)控機(jī)床上專用于工件和零件的夾持和自動(dòng)運(yùn)轉(zhuǎn)的裝置，其運(yùn)動(dòng)自由度多，且有嚴(yán)格的動(dòng)作順序要求、用液壓驅(qū)動(dòng)可實(shí)現(xiàn)動(dòng)作自動(dòng)循環(huán)，利于自動(dòng)化和高效率等要求。12課題內(nèi)容本課題的基本內(nèi)容是：1）功能原理方案分析2）液壓系統(tǒng)原理圖設(shè)計(jì)3）液壓系統(tǒng)的計(jì)算4）油箱與執(zhí)行元件工作圖設(shè)計(jì)5）編寫計(jì)算說明書13課題的意義本課題所研究的數(shù)控機(jī)床的裝夾裝置屬于工業(yè)機(jī)器人這一范疇，對(duì)它的研究實(shí)際上就是對(duì)工業(yè)機(jī)器人的研究?，F(xiàn)在工業(yè)機(jī)器人集機(jī)械、電子、控制、計(jì)算機(jī)、傳感器、人工智能等多學(xué)科先進(jìn)技術(shù)于一體的現(xiàn)代制造業(yè)重要的自動(dòng)化裝備。自從1962年美國研制出世界上第一臺(tái)工業(yè)機(jī)器人以來，機(jī)器人技術(shù)極其產(chǎn)品發(fā)展很快，已成為柔性制造系統(tǒng)（FMS）、自動(dòng)化工廠（FA）、計(jì)算機(jī)集成制造系統(tǒng)（CIMS）的自動(dòng)化工具。廣泛采用工業(yè)機(jī)器人，不僅可提高產(chǎn)品的質(zhì)量與產(chǎn)量，而且對(duì)保障人身安全，改善勞動(dòng)環(huán)境，減輕勞動(dòng)強(qiáng)度，提高勞動(dòng)生產(chǎn)率，節(jié)約原材料以及降低生產(chǎn)成本，有著十分重要的意義。和計(jì)算機(jī)、網(wǎng)絡(luò)技術(shù)一樣，工業(yè)機(jī)器人的廣泛應(yīng)用正在日益改善著人類的生產(chǎn)和生活方式。隨著加工行業(yè)在我國的迅速發(fā)展，各行各業(yè)的自動(dòng)化裝備水平越來越高，現(xiàn)代化加工車間，常常配有機(jī)械手，以提高生產(chǎn)效率，代替工人完成惡劣環(huán)境下危險(xiǎn)、繁重的勞動(dòng)。14課題的創(chuàng)新點(diǎn)采用手動(dòng)換向閥變換夾持方式，既可以雙夾持也可以單夾持。2機(jī)械手的功能設(shè)計(jì)21機(jī)械手液壓系統(tǒng)的各部分功能2.1.1 液壓站圖2-1液壓站液壓原理圖1蓄能器 2精過濾器 3.壓力繼電器 4.減壓閥 5.冷卻器 6.液壓馬達(dá)本設(shè)計(jì)應(yīng)用液壓站供應(yīng)小車，滑板和機(jī)器人手臂位移電液步進(jìn)式驅(qū)動(dòng)裝置以及手腕轉(zhuǎn)動(dòng)、擺動(dòng)機(jī)構(gòu)和夾持器夾緊機(jī)構(gòu)驅(qū)動(dòng)裝置。同時(shí)液壓站能夠相應(yīng)于在主干線恒壓下進(jìn)入液壓系統(tǒng)的耗油量來自動(dòng)變化可調(diào)泵的供給量。液壓站還進(jìn)行油的冷卻，并能防止在斷路狀態(tài)下液壓系統(tǒng)中漏油。2.1.2小車驅(qū)動(dòng)裝置圖2-2小車驅(qū)動(dòng)裝置液壓原理圖1.液壓馬達(dá)M1 2.單向閥 3.液壓分配器 4.步進(jìn)電動(dòng)機(jī) 小車的驅(qū)動(dòng)裝置由液壓馬達(dá)M1和成套步進(jìn)驅(qū)動(dòng)系統(tǒng)組成。當(dāng)信號(hào)傳遞到步進(jìn)馬達(dá)M5時(shí)，其轉(zhuǎn)子通過螺旋傳動(dòng)推動(dòng)液壓分配器的滑閥，他連接著壓力管和溢流管與相應(yīng)的液壓馬達(dá)腔。液壓馬達(dá)之間的連接使其在軸上的力矩方向相反，以保持在齒輪齒條傳動(dòng)中的無隙嚙合。在電液步進(jìn)驅(qū)動(dòng)裝置的液壓馬達(dá)傳動(dòng)時(shí)，其與分配器滑閥剛性相連的軸，使得滑閥回到初始位置，從而實(shí)現(xiàn)位置反饋。 手臂滑板移動(dòng)用線性電液步進(jìn)式驅(qū)動(dòng)裝置和手臂擺動(dòng)用線性電液步進(jìn)驅(qū)動(dòng)裝置是由步進(jìn)電動(dòng)機(jī)（M3和M4）、隨動(dòng)分配器和液壓缸組成，液壓缸活塞桿內(nèi)裝有位置反饋螺旋機(jī)構(gòu)。在信號(hào)傳遞到步進(jìn)電動(dòng)機(jī)時(shí)，其轉(zhuǎn)子通過螺旋傳動(dòng)推動(dòng)液壓分配器滑閥，開啟進(jìn)入液壓缸油通道。液壓缸活塞平行運(yùn)動(dòng)通過螺旋傳動(dòng)變?yōu)榻z桿傳動(dòng)，而通過齒輪傳動(dòng)和螺旋副變?yōu)榛y軸向移動(dòng)。單向閥的作用是用來防止液壓設(shè)備斷路時(shí)手臂桿件自然下垂。2.1.3 機(jī)械手腕轉(zhuǎn)動(dòng)（擺動(dòng)）圖2-3機(jī)械手手腕擺動(dòng)（轉(zhuǎn)動(dòng)）液壓原理圖1.定位器 2.液壓缸液壓操縱盤控制手腕轉(zhuǎn)動(dòng)（擺動(dòng)），取決于電磁鐵Y7或Y8及Y6，由取決于手腕（頭部）擺動(dòng)方向的旋轉(zhuǎn)指令控制。此時(shí)定位器的活塞克服彈簧力向上運(yùn)動(dòng)，并通過杠桿推動(dòng)隨動(dòng)滑閥，開啟油道通路，油通過分配器P2到液壓馬達(dá)M2的腔內(nèi)。此后，當(dāng)液壓馬達(dá)達(dá)到所需的轉(zhuǎn)速時(shí)，信號(hào)進(jìn)入電磁鐵斷路，從而使手腕固定和分配器P2斷路。液壓馬達(dá)轉(zhuǎn)速可以調(diào)節(jié)。在指令傳遞到液壓滑閥上的分配器P3和P4時(shí)，液壓馬達(dá)M3使手腕轉(zhuǎn)動(dòng)。在電磁鐵P4接通時(shí)，油在壓力下進(jìn)入控制液壓缸左腔。此時(shí)電磁鐵Y5斷開，則活塞移動(dòng)到極右位置，通過杠桿17推動(dòng)隨動(dòng)閥，并且開啟油通道，使油進(jìn)入液壓馬達(dá)M3腔內(nèi)。杠桿17的另一端安裝在手腕傳動(dòng)部分的靠模保持接觸。這樣當(dāng)手腕轉(zhuǎn)動(dòng)一定角度時(shí)（例如在極右位置）杠桿17使隨動(dòng)閥回到中間位置，且液壓馬達(dá)M3停止轉(zhuǎn)動(dòng)。當(dāng)電磁鐵Y5接通，Y4斷開，油在壓力下進(jìn)入控制液壓缸右腔，而其左腔與排油孔相連；活塞移動(dòng)到左邊位置，且液壓馬達(dá)M3將手腕轉(zhuǎn)動(dòng)到靠模的相應(yīng)突緣上。在電磁鐵Y2和Y5接通時(shí)，液壓缸2兩腔均與壓力管路相連，而由于活塞面積，使他停在套筒擋塊所確定的中間位置上。液壓馬達(dá)轉(zhuǎn)動(dòng)手腕到靠模中間凸緣上。2.1.4夾持器驅(qū)動(dòng)裝置圖2-4夾持裝置液壓原理圖1.手動(dòng)換向閥 2.單向閥液壓缸的驅(qū)動(dòng)裝置不但用于帶雙夾持器，又用于單夾持器。按夾持器型式，液壓操縱盤的閥式分配器用手動(dòng)擺放在左面或右面的位置。用單夾持器工作時(shí)用液壓分配器P5進(jìn)行控制。在接通電磁鐵Y2時(shí)，夾持器張開；而在斷開Y2時(shí)，夾持器產(chǎn)生壓緊動(dòng)作。裝在液壓操縱盤上的單向閥防止在系統(tǒng)中壓力下降時(shí)，夾持器迅速松開。在雙夾持工作時(shí)，通過接通電磁鐵Y2或Y3來傳遞給每一只手臂的松開指令。當(dāng)兩個(gè)磁鐵接通時(shí)（或斷開），夾持器同時(shí)被彈簧壓緊。22 機(jī)械手液壓系統(tǒng)的功能綜合總之，本次設(shè)計(jì)的機(jī)械手的總的功能如以下圖所示：圖2-5機(jī)械手總功能示意圖 小車，滑板和機(jī)器人手臂位移電液步進(jìn)式驅(qū)動(dòng)裝置以及手腕轉(zhuǎn)動(dòng)、擺動(dòng)機(jī)構(gòu)和夾持器夾緊機(jī)構(gòu)驅(qū)動(dòng)裝置都需要液壓系統(tǒng)來調(diào)控。23機(jī)械手電磁鐵動(dòng)作循環(huán)表表2-1機(jī)械手工作狀態(tài)以及動(dòng)作控制目標(biāo)工作狀態(tài)電 磁 鐵Y1Y2Y3Y4Y5Y6Y7Y8液壓站啟動(dòng)-工作+夾持器傳動(dòng)裝置夾緊+-+松開+-中間位置+-手腕（頭部）回轉(zhuǎn)傳動(dòng)裝置向右+-向左+-+中間位置+停止+-手腕（頭部）擺動(dòng)傳動(dòng)裝置向右+-向左+-+停止+-2.4 機(jī)械手液壓系統(tǒng)方案設(shè)計(jì)液壓執(zhí)行元件大體分為液壓缸或液壓馬達(dá)。前者實(shí)現(xiàn)直線運(yùn)動(dòng)，后者實(shí)現(xiàn)回旋運(yùn)動(dòng)，對(duì)于單純并且簡單的直線運(yùn)動(dòng)或回轉(zhuǎn)運(yùn)動(dòng)機(jī)構(gòu)，可以分別采用液壓缸或液壓馬達(dá)直接驅(qū)動(dòng)。根據(jù)設(shè)計(jì)目標(biāo)及現(xiàn)有條件,在查閱有關(guān)資料和實(shí)物調(diào)研的基礎(chǔ)上,構(gòu)建本機(jī)械手的總本設(shè)計(jì)方案如下:1.設(shè)計(jì)成一個(gè)數(shù)控機(jī)床搬運(yùn)機(jī)械手,用于將工件從工位I搬運(yùn)到工位。2.本機(jī)械手包含手指夾緊工件,手臂轉(zhuǎn)位,手指松開卸料,手臂復(fù)位四個(gè)基本動(dòng)作,采用手動(dòng)上下料等功能。3.具備自動(dòng)與手動(dòng)操作兩種工作方式并能快速靈活地切換且互鎖.手動(dòng)方式下操作者可以隨意地完成這四個(gè)基本動(dòng)作的任意組合;自動(dòng)方式下機(jī)械手的一個(gè)工作循環(huán)包括夾緊,轉(zhuǎn)位,卸料,復(fù)位,能夠穩(wěn)定可靠地重復(fù)循環(huán)工作。3機(jī)械手液壓系統(tǒng)機(jī)構(gòu)設(shè)計(jì)計(jì)算31負(fù)載分析311載荷的組成和計(jì)算如圖1表示一個(gè)以液壓缸為執(zhí)行元件的液壓系統(tǒng)計(jì)算簡圖。各參數(shù)標(biāo)注圖上，其中Fw是作用在活塞桿上的外部載荷，F(xiàn)m是活塞與缸壁以及活塞桿遇導(dǎo)向套之間的密封阻力。作用在活塞桿上的外部載荷Fg，導(dǎo)軌的摩擦力Ff和由速度變化而產(chǎn)生的慣性力Fa。圖3-1液壓缸受力簡圖（1）工作載荷Fd常見的工作載荷有作用于活塞桿上的重力、切削力、擠壓力等，這些作用力與活塞的運(yùn)動(dòng)方向相同為負(fù)相反為正。（2）導(dǎo)軌摩擦載荷摩擦阻力是指液壓缸驅(qū)動(dòng)工作機(jī)構(gòu)工作時(shí)所克服的機(jī)械摩擦阻力，對(duì)于機(jī)床來說，即導(dǎo)軌摩擦阻力，其值與導(dǎo)軌的形式，放置情況和運(yùn)動(dòng)狀態(tài)有關(guān)。在機(jī)床上經(jīng)常使用的平導(dǎo)軌和V型導(dǎo)軌水平放置。對(duì)于平道軌 f （3-1）對(duì)于V型導(dǎo)軌 f/sin（/2） （3-2）式中Fn作用在導(dǎo)軌上的法向力 V型導(dǎo)軌夾角 f導(dǎo)軌摩擦因數(shù)圖3-2 平導(dǎo)軌圖3-3 V型導(dǎo)軌本課題采用平軌，故：ff取滑動(dòng)導(dǎo)軌（材料鑄鐵對(duì)鑄鐵）低速（v10cm滿足最底速度的要求。3.4計(jì)算液壓缸各工作階段的工作壓力，流量，功率根據(jù)液壓缸的負(fù)載圖和速度圖以及液壓缸的有效面積，可以算出液壓缸工作過程各階段的壓力，在計(jì)算時(shí)工進(jìn)時(shí)的背壓力按Pb810Pa代入，快退時(shí)按Pb510Pa代入公式和計(jì)算結(jié)果如下表：表3-1各工作階段的工作壓力，流量，功率工作循環(huán)計(jì)算公式負(fù)載 進(jìn)油壓力回油壓力所需流量輸入功率F(N)P(Pa)Pn (Pa)L/minP(KW)差動(dòng)快進(jìn)Pjqv(A1A2)PP550.28.51013.51012.50.174工進(jìn)479.138.5108100.320.021快退40813.11051012.90.218注：1.差動(dòng)連接時(shí)，液壓缸的回油口到進(jìn)油口之間的壓力損失P510Pa，而PnPP2快退時(shí)，液壓缸有桿腔進(jìn)油。壓力為P，無桿腔回油，壓力為Pn。3.5 擬定液壓系統(tǒng)原理圖3.5.1 選擇液壓基本回路1確定調(diào)速方式及供油形式在液壓缸的初步計(jì)算前，已經(jīng)確定了采用調(diào)速閥的進(jìn)口節(jié)流調(diào)速，因此相應(yīng)采用開式循環(huán)系統(tǒng)，這種調(diào)速回路具有較好的低速穩(wěn)定性和速度負(fù)載特性。2快速運(yùn)動(dòng)回路和速度換接回路根據(jù)本設(shè)計(jì)的運(yùn)動(dòng)方式和要求，采用差動(dòng)連接和雙泵供油，兩種快速回路來實(shí)現(xiàn)快速運(yùn)動(dòng)，即快進(jìn)時(shí)，由大小泵同時(shí)供油，液壓缸實(shí)現(xiàn)差動(dòng)連接。采用二位三通電磁閥的速度換接回路，控制由快進(jìn)轉(zhuǎn)為工進(jìn)，與采用行程閥相比，電磁閥可直接安裝在液壓站上，由工作臺(tái)行程開關(guān)控制，管路較簡單，行程大小餓容易調(diào)整，另外采用液壓控制順序閥與單項(xiàng)閥來切斷差動(dòng)油路，因此速度換接回路為形成和壓力聯(lián)合控制形式。3換向回路選擇本系統(tǒng)對(duì)換向的平穩(wěn)性沒嚴(yán)格的要求，所以選用電磁換向閥的換向回路。為提高換向的位置精度，采用壓力繼電器的行程終點(diǎn)反程控制。3.5.2 組成液壓系統(tǒng)將選定的液壓回路進(jìn)行組合，并做出休整，即組成液壓系統(tǒng)圖。3.6選擇液壓元件3.6.1選擇液壓泵液壓系統(tǒng)的工作介質(zhì)完全由液壓源來提供，液壓源的核心是液壓泵。節(jié)流調(diào)速系統(tǒng)一般用定量泵供油，再無其他輔助油源的情況下，液壓泵的供油量要大于系統(tǒng)的需油量，多余的油經(jīng)溢流閥流回油箱，溢流閥同時(shí)起到控制并穩(wěn)定油源壓力的作用。容積調(diào)速系統(tǒng)多數(shù)是采用變量泵供油。對(duì)長時(shí)間所需油量較小的情況，可增設(shè)蓄能器作輔助油源。 工進(jìn)階段液壓缸工作壓力最大。若取壓力損失510 Pa壓力繼電器可靠動(dòng)作需要壓力差為510 Pa液壓泵最高工作液壓可按：因此泵的額定壓力可取Pa工進(jìn)所需的流量最小是0.32L/min，設(shè)備流量最小流量為2.5L/min，則小流量泵的流量按公式即2.85L/min快進(jìn)快退時(shí)液壓缸所需的最大流量是12.9L/min，則泵的總流量為：即大流量泵的流量：根據(jù)上面計(jì)算的壓力和流量，查產(chǎn)品樣本選用YB-4/12型的雙聯(lián)葉片泵，該泵的額定壓力為6.3MP，額定轉(zhuǎn)速為960r/min。3.6.2電動(dòng)機(jī)的選擇系統(tǒng)為雙泵供油系統(tǒng)，其中小泵1的流量為：大泵的流量為：差動(dòng)快進(jìn)快退時(shí)兩個(gè)泵同時(shí)向系統(tǒng)供油，工進(jìn)時(shí)，小泵向系統(tǒng)供油，大泵卸載，下面計(jì)算三個(gè)階段所需要的電動(dòng)機(jī)功率P。1.差動(dòng)快進(jìn) 差動(dòng)快進(jìn)時(shí)，大泵2m出口油經(jīng)單向閥與小泵匯合，然后經(jīng)單向閥2，三位五通閥3，二位三通閥4進(jìn)入液壓缸大腔，大腔的壓力查樣本可知，小泵的出口壓力損失，于是計(jì)算可得小泵的出口壓力（總效率），大泵出口壓力（總效率）。電動(dòng)機(jī)效率為：2工進(jìn)考慮到調(diào)速閥所需最小壓力壓力繼電器可靠動(dòng)作所需壓力差因此工進(jìn)時(shí)小泵的出口壓力而大泵的卸載壓力?。ㄐ”玫目傂剩╇妱?dòng)機(jī)功率：綜合比較 快退時(shí)所需功率最大，因此選用Y90l-6異步電動(dòng)機(jī)，電動(dòng)機(jī)功率1.1KW，額定轉(zhuǎn)速910r/min.3.6.3 選擇液壓閥根據(jù)液壓閥在系統(tǒng)中最高的工作壓力與通過的最大流量，可選出這些元件的型號(hào)及規(guī)格，本設(shè)計(jì)中所有閥是壓力為6310額定流量根據(jù)通過的流量是確定為10L/min，30L/min和63L/min三種規(guī)格。表3-2液壓閥的流量、型號(hào)和規(guī)格序號(hào)元件名稱通過流量（L/min）額定流量（L/min）額定壓力（MPa）額定壓降（MPa）型號(hào)、規(guī)格1過濾器34.8631.60.07XU-A63502單向閥34.8306.30.2I-30B3溢流閥3306.3Y-30B4節(jié)流閥22.2306.30.3L-30B5節(jié)流閥3.78/2.4/1106.30.3L-10B6三位四通電磁閥22.2306.30.434D-30B7二位四通電磁閥2.4106.30.424D-10B8二位二通電磁閥3.78106.30.422D-10B9減壓閥22.2306.3J-30B10三位四通電磁閥3.78/0.96106.30.434D-10B11減壓閥2.4106.3J-10B3.7 液壓缸基本參數(shù)的確定3.7.1 工作負(fù)載液壓缸的工作負(fù)載是指工作機(jī)構(gòu)在滿負(fù)載情況下，以一定的加速度啟動(dòng)時(shí)對(duì)液壓缸產(chǎn)生的總阻力。F=K （3-7）工作機(jī)構(gòu)的要求的負(fù)載力； K考慮缸本身的各種負(fù)載力的系數(shù)； K=1.2F缸的輸出力。由原始參數(shù)F=1.83N,則F=1.21.8310=2.210N3.7.2 定活塞桿直徑按簡單拉伸或壓縮的受力條件來確定活塞桿的直徑。 （3-8）材料的許用應(yīng)力。計(jì)算出的d 值如果太小，允許根據(jù)結(jié)構(gòu)要求加大。若遇到明顯過細(xì)過長的活塞桿，活塞桿又受壓，則須按壓桿穩(wěn)定的條件來確定活塞桿直徑。計(jì)算出的活桿直徑查GB2348-80圓整。=108.2 mm 圓整后,取桿徑d=110mm.3.7.3 根據(jù)速比定出缸筒直徑D速比根據(jù)工作機(jī)構(gòu)的要求提出作為已知參數(shù)。若工作機(jī)構(gòu)對(duì)無明顯要求可按表3-1選取。表3-3速比的推薦值1.061.121.251.41.622.55缸內(nèi)徑公式： 取=2， =155.56（mm）計(jì)算出的D值按表3-3 圓整表3-4 缸內(nèi)徑D系列（GB2348-80）(mm)810121620253240506380100125160200250320400圓整后取港的內(nèi)徑D=160mm。3.7.4 選擇設(shè)計(jì)壓力p 液壓件的額定壓力是在指定的運(yùn)轉(zhuǎn)條件下液壓件能長期正常工作的壓力。又叫公稱壓力。液壓件的工作壓力是指在真實(shí)系統(tǒng)中承受的壓力。若負(fù)載變化工作壓力的大小也會(huì)發(fā)生變化。系統(tǒng)的額定壓力可參照和現(xiàn)正設(shè)計(jì)的主機(jī)相同或類似的機(jī)器的系統(tǒng)壓力來選定缸的設(shè)計(jì)壓力。參見表3-5。表3-5 各類主機(jī)常用系統(tǒng)壓力主 機(jī) 類 型系統(tǒng)壓力（MPa）精加工機(jī)床半精加工機(jī)床精加工或重型機(jī)床農(nóng)業(yè)機(jī)械，小型工程機(jī)械、工程機(jī)械的輔助機(jī)構(gòu)液壓機(jī)、重型機(jī)械、超重機(jī)、大中型工程機(jī)械0.8-23-55-1010-1620-32表3-6 液壓缸公稱壓力系列（GB2346-80）(MPa)0.6311.62.546.310162540本設(shè)計(jì)中選設(shè)計(jì)壓力為p=10MPa.3.7.5 最小導(dǎo)向長度的確定當(dāng)活塞桿全部外伸時(shí)，從活塞支撐面中點(diǎn)到導(dǎo)向套滑動(dòng)面中點(diǎn)的距離稱為最小導(dǎo)向長度 H（圖3-4）。圖3-4 最小導(dǎo)向長度 H示意圖如果導(dǎo)向長度過小，將使液壓缸的初始饒度增大，影響液壓缸的穩(wěn)定性，因此在設(shè)計(jì)時(shí)必須保證有一定的最小導(dǎo)向長度。 對(duì)于一般的液壓缸，其最小導(dǎo)向長度應(yīng)滿足下式要求：（m） （3-9）式中 L液壓缸最大工作行程(m)； D缸筒內(nèi)徑（m）.本設(shè)計(jì)中，L=1750mm=1.75m; D=160mm=0.16m.=0.1675m 符合要求。3.8 液壓缸結(jié)構(gòu)強(qiáng)度計(jì)算和穩(wěn)定校驗(yàn)3.8.1 缸筒外徑計(jì)算缸內(nèi)徑確定之后，由強(qiáng)度條件來計(jì)算缸筒壁厚，然后計(jì)算出缸筒的外徑，按JB2183-77或其它相應(yīng)標(biāo)準(zhǔn)圓整為標(biāo)準(zhǔn)外徑。1.缸筒壁厚的計(jì)算(1)薄壁缸筒缸筒壁厚與內(nèi)徑D之比小于1/10者，稱為薄壁缸筒，壁厚按薄壁筒公式計(jì)算，則 (m) （3-10）式中 p液壓缸的最大工作壓力（Pa）; D缸筒內(nèi)徑（m）; 缸筒材料的許用應(yīng)力（Pa）;= 缸筒材料的抗拉強(qiáng)度極限（Pa）; n安全系數(shù)，一般取n=5.本設(shè)計(jì)中：=47 MPa 圓整后，取2.缸筒外徑的確定: 3.8.2 缸底厚度缸底為平底時(shí)，可由材料力學(xué)中圓盤計(jì)算公式導(dǎo)出。缸底厚度: 取3.8.3 液壓缸的穩(wěn)定性和活塞桿強(qiáng)度的驗(yàn)算 前面對(duì)活塞桿直徑僅按速比作了初步確定，活塞直徑還必須同時(shí)滿足液壓缸的穩(wěn)定性及其本身的強(qiáng)度要求。 1.液壓缸穩(wěn)定性驗(yàn)算 根據(jù)材料力學(xué)概念，液壓缸的穩(wěn)定條件為 （N） （3-11） 式中 P活塞桿的最大推力（N）; 液壓缸穩(wěn)定臨界力（N）; 穩(wěn)定性安全系數(shù)，一般取=2-4。液壓缸的穩(wěn)定臨界力值與活塞桿和缸體的材料、長度、剛度以及兩端承狀況有關(guān)。一般l/d大于10以后就要進(jìn)行穩(wěn)定校驗(yàn)。圖3-5 液壓缸的安裝形式和活塞桿計(jì)算長度用歐拉公式計(jì)算=110/4=27.5 mm=101.8當(dāng)時(shí)，由歐拉公式 （N） （3-12）式中 活塞桿計(jì)算柔度（柔性系數(shù)）； 長度折算系數(shù)，取決于液壓缸的支承在狀況，如圖4-5所示； l活塞桿計(jì)算長度（即液壓缸安裝長度，m）； E活塞桿材料的縱向彈性模數(shù)，E=20.59； i活塞桿橫斷面回轉(zhuǎn)半徑， （m），其中A為斷面面積（）,I為斷面最小慣性矩（）。對(duì)圓斷面，； 柔性系數(shù)（按表3-7選取），表3-7 柔性系數(shù)表材料ab鋼(A3)鋼(A5)硅鋼鑄鐵310046005890770011.4036.1738.1712010510010080616060- 本設(shè)計(jì)中，1，l=1.750m, E=20.59,I=iA=7.18=N故=N,完全符合穩(wěn)定性要求。3.8.4 活塞組件活塞組件活塞和活塞桿。這部分的結(jié)構(gòu)活塞和活塞桿的聯(lián)結(jié)，活塞桿頭部的結(jié)構(gòu)兩方面的問題。根據(jù)工作壓力、安裝形式及工作條件的不同，活塞組件也有多種結(jié)構(gòu)形式。1.活塞與活塞桿的聯(lián)結(jié)活塞和活塞桿的聯(lián)結(jié)可采用螺紋連接和非螺紋連接兩種形式。非螺紋連接常用于大工作壓力的場合，本設(shè)計(jì)中采用的是螺紋連接。2.活塞桿頭部結(jié)構(gòu)活塞桿頭部直接和工作機(jī)械聯(lián)系，根據(jù)與負(fù)載連接的要求不同，活塞桿頭部主要有如下幾種結(jié)構(gòu)：（1）單耳環(huán)不帶襯套式；（2）單耳環(huán)帶襯套式；（3）單耳環(huán)式；（4）雙耳環(huán)式；（5）球頭式；（6）外螺紋式；（7）內(nèi)螺紋式。本設(shè)計(jì)中考慮到液壓缸和機(jī)械裝置的連接形式，采用單耳環(huán)帶襯套式的頭部結(jié)構(gòu)。3.8.5 密封裝置液壓缸在工作時(shí)，缸內(nèi)壓力較缸外的壓力高的很多；缸內(nèi)的進(jìn)油腔壓力較回油腔壓力也高的很多，這樣，油液就可能通過固定件的聯(lián)結(jié)處和相對(duì)運(yùn)動(dòng)的配合間隙處泄漏，這種泄漏既有內(nèi)泄也有外泄，外泄不但使油液損失影響環(huán)境，而且有著火的危險(xiǎn)。內(nèi)泄則能使油液發(fā)熱，液壓缸的容積效率降低，從而使液壓缸的工作性能變壞。因此應(yīng)最大限度的減少泄漏。活塞和缸筒內(nèi)壁之間的滑動(dòng)和密封，目前主要有這樣幾種方案：第一種方案是靠活塞直接與缸壁接觸滑動(dòng)，密封由O型圈來實(shí)現(xiàn)，這種方案構(gòu)造簡單摩擦阻力小，但密封壽命低，而且工藝要求高；第二種方案是采用V型密封圈，這種密封圈的特點(diǎn)是可以支承一定的徑向力，但活塞運(yùn)動(dòng)時(shí)的磨擦阻力大；第三種方案是目前工程機(jī)械上用的最普遍的一種，活塞上套一個(gè)用耐磨材料（尼龍或聚四氟乙烯）制成的支承環(huán)，用以代替活塞與缸壁的磨擦，可降低摩擦系數(shù)和提高液壓缸的壽命，它不起密封作用，密封靠一對(duì)小Y型密封圈，本設(shè)計(jì)即采用第三種方案。3.8.6 緩沖裝置液壓缸一般都設(shè)有緩沖裝置，特別是活塞運(yùn)動(dòng)速度較高和運(yùn)動(dòng)部件較大時(shí)，為了防止活塞在行程終點(diǎn)與缸蓋或缸底發(fā)生機(jī)械碰撞，引起噪聲、沖擊，甚至造成液壓缸或被驅(qū)動(dòng)件的損壞，則必須設(shè)置緩沖裝置。 a)固定節(jié)流孔緩沖器 b)節(jié)流槽緩沖機(jī)構(gòu) c)溢流閥緩沖機(jī)構(gòu)圖3-6 節(jié)流緩沖裝置 本設(shè)計(jì)中采用的緩沖裝置為溢流閥的緩沖裝置，如果不考慮溢流閥的壓力超調(diào)值，則該緩沖裝置為恒壓等減速緩沖裝置。優(yōu)點(diǎn)是隨運(yùn)動(dòng)部件的質(zhì)量和初速度V。的不同，緩沖壓力可以調(diào)節(jié)。3.8.7 油管的選擇根據(jù)選定的液壓閥連接油口尺寸確定管道尺寸。液壓缸進(jìn)出油管按輸出，排出的流量來計(jì)算。由于系統(tǒng)液壓缸差動(dòng)連接快進(jìn)快退時(shí)，油管內(nèi)通油量最大其實(shí)際流量為泵的額定流量的兩倍達(dá)32L/min，則液壓缸進(jìn)出油口直徑d按產(chǎn)品樣本，選用內(nèi)徑為15mm，外徑為19mm的10號(hào)冷拔鋼管。3.8.8 油箱容積的確定取油箱的有效容積為泵每分鐘排除液體體積的1.2倍，上述的有效容積是指油箱中油所占據(jù)的容積，其實(shí)際含義是系統(tǒng)正常工作時(shí)油箱中的油所占據(jù)的容積，和系統(tǒng)中的油全部流回油箱所占的容積，這兩部分之總和，油箱的總?cè)莘e是指油箱的有效容積和油箱中空氣所占據(jù)的容積的總和，空氣的體積約為油箱總?cè)莘e的10%。本設(shè)計(jì)中，液壓泵的流量為230L/min，即每分鐘流量為230升。圓整后取280升。擬定油箱的長、寬、高為。3.9液壓傳動(dòng)用油的選擇油液在液壓系統(tǒng)中實(shí)現(xiàn)潤滑與傳遞動(dòng)力的雙重功能,必須根據(jù)使用環(huán)境和目的慎重選擇。3.9.1 工作介質(zhì)的選擇根據(jù)液壓工作介質(zhì)的使用要求，選取L-HL型液壓油。該液壓油的特征和主要應(yīng)用：本產(chǎn)品為精制礦物油，并改善其防銹和抗氧性的潤滑油，常用于低壓液壓系統(tǒng)，也可適用于要求換油期較長的輕負(fù)荷機(jī)械的油浴式非循環(huán)潤滑系統(tǒng)。3.9.2 介質(zhì)粘度的選擇液壓系統(tǒng)所有元件中，以液壓泵的轉(zhuǎn)速最高，壓力大，溫度較高。一般應(yīng)根據(jù)液壓泵的要求來確定液壓油的粘度。根據(jù)表3-8選擇L-HL46。表3-8液壓油的粘度名稱粘度（/s）工作壓力（MPa）工作溫度（）推薦用油允許最佳齒輪泵4220255412.5以下540L-HL32, L-HL464080L-HL46, L-HL681020540L-HL46 ,L-HL684080L-HL46 ,L-HL681632540L-HL32, L-HL684080L-HL46, L-HL684驗(yàn)算系統(tǒng)液壓性能4.1壓力損失的驗(yàn)算及泵壓力的調(diào)整1工進(jìn)時(shí)壓力損失的驗(yàn)算和小流量泵壓力的調(diào)整工進(jìn)時(shí)管路中的流量僅為0.32L/ min,因此流速很小，所以沿程損失和局部壓力損失都非常小，可以忽略不計(jì)。這時(shí)進(jìn)油路上僅考慮調(diào)速閥的壓力損失，回油路只有背壓閥的壓力損失，小流量泵的調(diào)整壓力應(yīng)等于工進(jìn)時(shí)液壓缸的工作壓力P加上進(jìn)油口的壓力差，并考慮繼電器的動(dòng)作需要?jiǎng)t：即小流量的溢流閥口按此壓力調(diào)整。2快退時(shí)的壓力損失驗(yàn)算及大流量泵卸載壓力的調(diào)整因快退時(shí)液壓缸無桿腔的回油量是進(jìn)油量的2倍，其壓力損失比快進(jìn)時(shí)的大，因此必須計(jì)算快退時(shí)的進(jìn)油路與回油路的壓力損失，以便確定大流量泵的卸載壓力。進(jìn)油管和回油管長度均為l=1.8mm，油管直徑，通過的油量為進(jìn)油路回油路液壓系統(tǒng)選用L-HL46號(hào)液壓油，考慮最底工作溫度為15。由手冊(cè)查出此時(shí)油的運(yùn)動(dòng)粘度，油的密度，液壓系統(tǒng)元件采用集成塊式的配置形式。1） 確定油流的流動(dòng)狀態(tài)，按公式 （3-13）式中 v平均流速（m/s）; d油管內(nèi)徑（m） 油的運(yùn)動(dòng)粘度（cm/s） q通過的流量（m）則進(jìn)油路中油流的雷諾數(shù)為：回油路中液流的雷諾數(shù)為：由上可知進(jìn)出油路中的流動(dòng)都是層流。2）沿程壓力損失由下面公式可以算出進(jìn)油路和回油路的壓力損失在進(jìn)油路上，流速，則壓力損失為：在回油路上，流速為進(jìn)油路的兩倍即v=3.02m/s，則壓力損失為3）局部壓力損失由于采用集成塊式的液壓裝置，所以只考慮閥類元件和集成塊內(nèi)的壓力損失。通過各閥局部壓力損失可得見表（3-9）：表3-9各閥的壓力損失序號(hào)元件名稱通過流量（L/min）額定流量（L/min）額定壓降（MPa）壓降（MPa）型號(hào)、規(guī)格1過濾器34.8630.070.021XU-A63502單向閥34.8300.20.2I-30B3溢流閥330Y-30B4節(jié)流閥22.2300.30.16L-30B5節(jié)流閥3.78/2.4/1100.30.0430.0170.003L-10B6三位四通電磁閥22.2300.40.2234D-30B7二位四通電磁閥2.4100.40.02324D-10B8二位二通電磁閥3.78100.40.05722D-10B9減壓閥22.230J-30B10三位四通電磁閥3.78/1100.1mm）、普通的（d0.01mm）、精的（d0.005mm）、特精的（d0.001mm）。不同的液壓系統(tǒng)，對(duì)濾清器的過濾精度要求如下表：表4-1 濾清器的過濾精度要求系統(tǒng)類別潤滑系統(tǒng)傳動(dòng)系統(tǒng)隨動(dòng)系統(tǒng)特殊要求系統(tǒng)壓力(Pa)0-257070350210350顆粒度（mm）0.10.025-0.050.0250.0050.0050.0012. 能滿足液壓系統(tǒng)對(duì)過濾能力的要求 濾油器的過濾能力，是指在一定壓差下，允許通過濾油器的最大流量。一般用濾油器的有效過濾面積（濾芯上能通過的油液的總面積）來表示。對(duì)濾油器過濾能力的要求，應(yīng)結(jié)合濾油器在系統(tǒng)中的安裝位置來考慮。如安裝在液壓泵吸油管路上的濾油器，其過濾能力應(yīng)為液壓泵流量的兩倍以上。3. 濾油器的材料應(yīng)具有一定的機(jī)械強(qiáng)度，保證在一定的工作壓力下不會(huì)因液壓力的作用而受到破壞4. 在一定的工作溫度下，應(yīng)能保證性能穩(wěn)定，有足夠的耐久性5. 有良好的抗腐蝕能力6. 結(jié)構(gòu)盡量簡單，尺寸緊湊7. 便于清洗維護(hù)，便于更換濾芯8. 造價(jià)低廉4.3.2 濾油器的種類濾油器按過濾精度分粗、普通、精、特精四類。濾油器還可按濾芯的結(jié)構(gòu)分類1. 網(wǎng)式濾油器，油液流經(jīng)此濾油器時(shí)，由濾網(wǎng)上的小孔起濾清作用。2. 線隙式濾油器，濾芯由金屬絲繞制而成，依靠金屬絲間的微小間隙來過濾混入油液中的雜質(zhì)。3. 紙質(zhì)濾油器，濾芯為多層酚醛樹脂處理過的微孔濾紙，由微孔濾掉混入油液中的雜質(zhì)。4. 磁性濾油器，依靠永久磁鐵，利用磁化原理來濾除混入油液中的鐵屑。5. 燒結(jié)式濾油器，濾芯為顆粒狀青銅粉末等金屬粉末壓制燒結(jié)而成，利用顆粒之間的微孔濾去混入油液中的雜質(zhì)。6. 不銹鋼纖維濾油器，濾芯為不銹鋼纖維壓制制成，由纖維絲之間的間隙濾掉混入油液中的雜質(zhì)，這種濾油器的過濾精度高，可承受200bar的壓差，可以清洗，但因?yàn)闉V芯價(jià)格昂貴，一般液壓系統(tǒng)并不采用，只推薦在高壓伺服系統(tǒng)中應(yīng)用。7. 合成樹脂濾油器，濾芯由一種無機(jī)纖維經(jīng)液態(tài)樹脂浸滯處理制成。由于微孔很小、牢度很大，因此過濾精度高，且能承受210bar的壓差。4.3.3 線隙式濾油器如圖 4-1 所示，線隙式濾油器的濾芯由銅絲（d=0.4mm）繞成，依靠銅絲間的微小間隙來濾除混入油液中的雜質(zhì)。線隙式濾油器分為壓油管路用線隙式濾油器和吸油管路用線隙式濾油器兩種。圖 4-1 線隙式濾油器圖示為壓油管路用線隙式濾油器，有外殼1；當(dāng)用于吸油管路時(shí)不用外殼，濾芯部分2直接進(jìn)入油液中。壓油管路用線隙式濾油器的過濾精度分0.03 mm和0.08mm 兩類，壓力損失小于0.6bar；吸油管路用濾油器的過濾精度分0.05mm和0.1mm兩類，壓力損失小于0.2bar。線隙式濾油器結(jié)構(gòu)簡單，通油能力大，過濾精度比網(wǎng)示濾油器高，缺點(diǎn)是不易清洗，一般用于低壓回路或輔助回路。4.3.4 濾油器在液壓系統(tǒng)中的安裝位置和維護(hù)安裝位置濾油器的連接形式有板式、管式和法蘭式三種，可以安裝在液壓泵的吸油管路上、壓油管路上、回油路上、輔助泵的輸油路上、支流管路上或單獨(dú)過濾。本課題中濾油器安裝在液壓泵的吸油管路上，如圖4-2 ，將粗濾油器裝在液壓泵的吸油管路上，主要目的是保護(hù)液壓泵免遭較大顆粒雜質(zhì)的直接傷害。為了不置影響液壓泵的吸油能力，裝在吸油管路上的濾油器的通油能力應(yīng)大于液壓泵流量的兩倍。濾油器應(yīng)經(jīng)常清洗，以免過多增加液壓泵的吸油能力。圖4-2 濾油器安裝位置結(jié) 論這次畢業(yè)設(shè)計(jì)，我主要對(duì)機(jī)械手液壓系統(tǒng)進(jìn)行設(shè)計(jì)。機(jī)械手有下列基本組成部分：小車，滑板和機(jī)器人手臂位移電液步進(jìn)式驅(qū)動(dòng)裝置以及手腕轉(zhuǎn)動(dòng)、擺動(dòng)機(jī)構(gòu)和夾持器夾緊機(jī)構(gòu)驅(qū)動(dòng)裝置。而液壓系統(tǒng)是上述各裝置的動(dòng)力來源。為了更好的對(duì)液壓系統(tǒng)進(jìn)行分析，首先對(duì)機(jī)械手的四個(gè)主要的動(dòng)作進(jìn)行了液壓回路計(jì)算和方案設(shè)計(jì)。運(yùn)用的方案都是根據(jù)機(jī)械手自身的特點(diǎn)而選擇采用的，并且，經(jīng)過性能驗(yàn)算是可以使用的。擬定了機(jī)械手液壓系統(tǒng)原理圖后，再對(duì)液壓系統(tǒng)的主要元件進(jìn)行了選擇，依據(jù)的原則是系統(tǒng)的流量和壓力。在對(duì)液壓缸和液壓油箱的結(jié)構(gòu)設(shè)計(jì)過程中，通過對(duì)各種結(jié)構(gòu)方案的選擇比較，確定各部分的結(jié)構(gòu)，最終繪出液壓缸和油箱的裝配圖，完成此次設(shè)計(jì)任務(wù)。通過這次綜合設(shè)計(jì)，我在各方面都得到較全面的鍛煉。比如：能學(xué)會(huì)全面系統(tǒng)得查找翻閱有關(guān)資料，研究分析設(shè)計(jì)數(shù)據(jù)，這樣一來，培養(yǎng)了自己嚴(yán)謹(jǐn)踏實(shí)的學(xué)習(xí)工作態(tài)度及獨(dú)立完成任務(wù)的能力。綜合多學(xué)科知識(shí)，使自己在大學(xué)四年中所學(xué)編號(hào)： 畢業(yè)設(shè)計(jì)(論文)外文翻譯（原文）題 目：Dynamic load analysis and Design methodology of LCD transfer robot院 （系）： 機(jī)電工程學(xué)院 專 業(yè)：機(jī)械設(shè)計(jì)制造及其自動(dòng)化學(xué)生姓名： 呂 強(qiáng) 學(xué) 號(hào)： 1000110125 指導(dǎo)教師單位： 機(jī)電工程學(xué)院 姓 名： 唐 焱 職 稱： 副教授 題目類型：理論研究 實(shí)驗(yàn)研究 工程設(shè)計(jì) 工程技術(shù)研究 軟件開發(fā) 2014年5月25日Dynamic load analysis and design methodology of LCD transfer robotJong Hwi Seo1, Hong Jae Yim2,*, Jae Chul Hwang1, Yong Won Choi1 and Dong Il Kim 11Robotics Technology Lab, Mechatronics & Manufacturing Technology CenterSAMSUNG Electronics Co., LTD. Suwon, South Korea2School of Mechanical and Manufacturing Engineering, Kookmin University SeongBuk-Gu, Seoul, South Korea(Manuscript Received July 20, 2007; Revised December 28, 2007; Accepted January 16, 2008)AbstractThe objective of the present study is to develop a design methodology for the large scale heavy duty robot to meet the design requirements of vibration and stress levels in structural components resulting from exposure of system modules to LCD (Liquid Crystal Display) processing environments. Vibrations of the component structures significantly influence the motion accuracy and fatigue damage. To analyze and design a heavy duty robot for LCD transfer, FE and multi-body dynamic simulation techniques have been used. The links of a robot are modeled as flexible bodies using modal coordinates. Nonlinear mechanical properties such as friction, compliance of reducers and bearings were considered in the flexible multi-body dynamics model. Various design proposals are investigated to improve structural design performances by using the dynamic simulation model. Design sensitivity analyses with respect to vibration and stresses are carried out to search an optimal design. An example of an 8G (8th-Generation) LTR (LCD Transfer Robot) is illustrated to demonstrate the proposed methodology. Finally, the results are verified by real experiments including vibration testing.Keywords: Flexible multibody dynamics; LTR (LCD Transfer Robot); Vibration fatigue1. IntroductionLCDs are widely used in TVs, computers, mobile phones, etc., because they offer some real advantages over other display technologies. They are thinner and lighter and draw much less power. Recently, the size of raw glass has greatly increased in new generation LCD (Liquid Crystal Display) technology. In order to handle bigger and heavier glasses, it is necessary to develop a large scale LTR (LCD transfer robot) to support various complicated LCD fabrication processes.It will cause many difficult design problems such as vibration, handling accuracy deterioration and high stresses due to heavier dynamic loads, resultingin inaccurate transfer motion and fatigue cracks. Therefore, it is necessary to establish a methodology for predicting deflections, vibrations, and dynamic stress time histories using virtual computer simulation models. An integrated design simulation method would be useful to validate a baseline design and to propose new improved designs. In this paper an integratedcomputer simulation methodology is presented to predict deflections, dynamic stresses due to vibrations design, based on the existing FEM and flexible body dynamics technology.The proposed methodology is applied to the LTR that handles 7G/8G LCD glasses. Vibration analysis is performed and validated with the vibration modal test to identify and to recapture the inherent phenomenon in the system. Some flexible components in the LTR may experience severe vibration to cause fatigue damage due to large dynamic loads. Modal characteristics are used to consider structural flexibility in flexible multi-body dynamic simulations. Tip deflection of the end-effecter can be calculated to see if design requirements are met. Dynamic loads and dynamic stress histories can be obtained from the dynamic simulation. Stress levels are investigated at the critical areas to predict if fatigue cracks might occur. If the stress level is not in a safe region, design change should be made based on the computer simulation results and design sensitivity study. Then a prototype LTR is built and tested for design validation.The present paper describes the CAE-based durability analysis that is being implemented and developed at SAMSUNG, to predict fatigue damage corresponding to durability tests. The proposed methodology can be used to develop a new large scale LTR robot in the early design stage.2. Introduction of LCD-transfer robotFig. 1 shows various types of LTRs. Telescope type LTR consists of a base frame, an R-frame, two Z-frames, two articulated arms with slender hands as shown in Fig. 1(a). The frame structures are fabricated with cast iron and aluminium. Hands with slender fingers are made of lightweight composite materials.It also has two arms (upper and lower arms) to handle two glasses simultaneously. The LTR has a cylindrical workspace to transfer glasses for various fabrication processes. For precision control of handling the glasses, static deformation at the tip of the finger must be less than 10 mm. Since the joints which connect the arms and links include bearings and reducers, joint compliance must be considered to predict the static deformation at the tip. Flexibilities of the arm itself are also important to both static and dynamic deformation, because the arm is a kind of cantilever type structure with a large lumped mass at the tip.LTR is supposed to repeat millions of cycles to perform LCD fabrication processes in real life. Therefore, it has to pass physical tests to ensure the survivability of the robot system when subjected to static and cyclic loadings. The durability test involves a cyclic loading apparatus that evaluates the durability characteristics of the component structure. Among the many different tests, one of the most critical is the hand motion of stretching out and pulling in with the zframes vertical motion. The critical motion simulates the jerking and twisting impact that an arm support bracket might experience when running with large glasses loaded. The arms and hands are synchronized and moved at a speed of about 4 m/s.(a) Telescopic type(b) Gate type(c) Link typeFig. 1. LCD Transfer robots (LTR).Since the LTR repeats millions of cycles of particular loading and unloading with various configurations,it may result in fatigue failure at a critical stress area.In this paper, to predict static and dynamic deformation at the tip of the finger and critical stress levels including vibration of the LTR, flexible multi-body dynamic simulations are presented. Link-frames,arms are modelled as flexible bodies. Static and dynamic deformation is assumed to be very small, therefore,within the linear elastic range. To represent the flexibility, vibration normal modes and static correction modes are obtained from the finite element vibration and static analysis for each flexible component.To represent the joint compliance, spring and damper force elements are used instead of kinematic joint elements 1.3. Flexible multi-body dynamicsThe main advantage of using modal coordinates in flexible multi-body dynamics is the reduction in the number of generalized coordinates that must be included in the analysis. Two types of modes are used in component mode synthesis for flexible multi-body dynamics 1, 2. One is a normal mode. The other is a static mode. All used normal modes and static modes must be normalized to have the same magnitude and be orthogonalized to be independent to each other.3.1 Kinematics of flexible componentsA typical flexible component is shown in Fig. 2. The flexible component i is discretized into a large number of finite elements. The global position of a point p in a flexible part i can be represented asWhere is the global position vector of the X-Y-Z body reference frame, is the coordinate transformation matrix from the body reference frame to the global inertial frame, is the initial position vector of the point p from the body reference frame, and is the displacement vector due to deformation.The displacement vector can be approximated by a linear combination of deformation modes like Eq. (2). Whereis a modal matrix and is the corresponding deformation mode of a flexible part i. is a 6N1 modalvector and is modal coordinates, M is the number of modal coordinates. The deformation modes can be normal modes, static modes, or combination of normal and static modes. Used M modes should be linearly independent to each other.3.2 Flexible multi-body dynamic equationsAs shown in Fig. 2, the nodal position vector of a typical point p in the global reference frame can thus be written as Eq. (3) by using Eq. (2)Where and the rotational displacementi of nodal point p is defined by . The combined set of kinematic and driving constraints of the multi-body dynamic system may be written in the form 3, 4Where the generalized coordinates ，t is the time, is the constraint equation. Using the Lagrange Multiplier Theorem, variational equations of motion of the multi-body system may be obtained by summing all bodies and constraints in the system as in the matrix form of Eq.This is a mixed system of differential-algebraic equations of motion for considering the elastic effect of the mechanical system. To solve mixed differential algebraic equations, many numerical algorithms have been developed 3. Using Eq. (5), dynamic stress history of a flexible component can be calculated 5.4. Dynamic modelling of an lcd-transfer robotThe 8G-Telescopic type LTR system shown in Fig.Fig. 3. Flexible multi-body dynamics model for 8G-TelescopicLTR.Fig. 4. Dynamic modeling of LTR arm system1(a) can be modeled with 86 rigid bodies, 30 flexible bodies, kinematic joints, and force elements 3. The flexible bodies considered in the multi-body dynamic simulation are named in the Fig. 1(a). Fig. 3 shows the flexible multi-body simulation model for 8GTelescopic LTR.For parallel rectilinear motion of the finger and hand-bracket, a timing belt at each arm system is modeled to drive at constant speed ratio. As shown in Fig. 4, to represent the elasticity and damping of the belt, spring and damping forces are approximated to be proportional to displacement and velocity of the belt length change. Even the joint compliances for bearing and reducers are modeled in a similar way with rotational-spring and damper elements. The experimental values from the components makers are shown in Table 1.Major components such as arms and link frames are made of cast iron or cast aluminium. Those structural components can be assumed to be linear elastic during normal operation. However, such a small elastic deformation may cause vibration and repeated dynamic stresses resulting in inaccurate transfer motion and fatigue cracks. Therefore, it is necessary to establish a methodology for predicting the deformation, vibration, and dynamic stress time histories with a virtual computer simulation model.Component mode synthesis technique 1-4, explained in the previous section, can be used for efficient computer simulation in large rigid body gross motion with small elastic deformation. Since the component mode synthesis method employs modal coordinates to consider the elastic deformation of flexible bodies, it is possible to execute a large multibodydynamic system analysis more effectively by using a small number of well-selected modes.Fig. 5 shows the 1st vibration modes of flexible components in the telescopic LTR in Fig. 1(a). Also,Fig. 5 shows a typical component mode and the number of modes used in the mode component synthesis method for the flexible multi-body dynamic analysis.Table 1. Joint stiffness for bearing and reducers.NoAxialStiffness RadialStiffness Part1180 KNm/rad2570 KNm/radReducer2250 KNm/rad3510 KNm/radReducer367 KNm/rad1000 KNm/radReducer46745 KNm/rad43840 KNm/radReducer50436360 KNm/radBearing(a) Finger (36) (c) Arm-Frame (42) (d) Z1-Frame (24) (e) Z2-Frame (24) (f) R-Frame (36)Fig. 5. Component modes of flexible bodies (number ofmodes used for dynamic simulation).5. Analysis and design improvement of LTR5.1. Modal analysis of 8G-telescopic LTRSince major structural bodies such as arms and link-frames are modelled as flexible bodies, the proper kinematic joints and force elements, fundamental vibration modes of the total LTR system can be investigated. The modes calculated from the vibration analysis can be used for searching for the structural weak point and used for the flexible multi-body dynamic simulation explained in the previous chapter. Fig. 6 shows the modal deformation from the vibration test of the LTR system. Analytical vibration modes calculated from the dynamic simulation model are compared with the experimental test results for validation. Comparison with the modal test results showed that simulation results correlate well with the test results. From the results of the analytical and experimental modal deformation, we found that the structural weak point was the R-frame. This information was very important to reduce the system vibration,as explained in the following section.5.2 Vibration analysis and design improvementDesign problems such as tip deflection and fatigue crack can be investigated with a valid simulation model. Among the various process events for LCD glass transfer motion, stretching out and pulling in motions of the hands with glass loaded are the most critical motions to cause severe vibration and high stresses at the supporting bracket structure. Using the proposed flexible multi-body simulation technology, the critical motion is regenerated to investigate how large deflection and stresses occur during the operation. Since we have a valid simulation model, we can investigate various design proposals.After the prototype robot was developed, undesirable vibration at the measure point was observed when the robot was running onto the guide rail, as shown in Fig. 7. The cause of the vibration was the insufficient stiffness of the R-frame, studying from the analysis of the system modal deformation, as explained in the previous section. In other words, the Rframe at the base of the LTR was known to be a critical component for the vibration.To increase bending and twisting stiffness, height and width of the beam cross section was enlarged,and ribs were added as explained in the Fig. 7. Even aluminium material is replaced with high strength steel to increase the elastic modulus. To verify the design modification, a dynamic simulation model was used. Fig. 6. Vibration modes by experiment and comparison of frequenciesFig. 7. Design study to reduce the vibration by dynamics simulation.Fig. 8. Comparison of vibration levels between the original and modified design. Fig. 9. An example of the crack fatigue.Fig. 8 shows a comparison of vibration displacements during the simulated motions between the original baseline design and the new improved design. More than 50% reduction of the vibration level is observed during the critical motion period from 5 to 10 seconds even at the prototype test as shown in Fig. 8.5.3 Stress analysis and design improvementAs the size of raw glass tends to become larger for productivity and manufacturing cost competitiveness,LTR robots need to be faster and bigger to handle the larger and heavier glasses with higher speed. This may result in increased dynamic loads causing fatiguecracks due to dynamic stresses.Fig. 9 shows an example of the fatigue cracks due to dynamic loads at the supporting arm-frame structure in the 7G-Gate LTR shown in Fig. 1(b). Using the flexible multi-body dynamic simulation, cause and effect for the fatigue crack can be analyzed prior to adoption in an actual spot. To reduce the level of dynamic stress at the critical area, the shape andthickness of the structure must be redesigned based on the validated simulation model. Experimental tests were executed to validate the accuracy of dynamic stresses predicted in virtual computer simulations, as shown in Fig. 10. And the result was exactly the sameas the point of occurrence of the crack. Fig. 11 shows the design modification. To reduce the stress concentration, the rectangular shape with sharp corners was changed to a round shape, and ribs were changed.Fig. 12 shows a comparison of maximum dynamic stresses between the modified shape and original shape with different metal thickness. The stress measure point of the part is the dotted circle area in the Fig. 10. This result shows the conclusion that the design was reasonably modified. Practically, the modified design was adopted for the 7G-Gate LTR in the actual spot. Fig. 10. Strain experiment and dynamic analysis for fatigue life prediction.Fig. 11. Design modification for avoiding stress concentration.Fig. 12. Stress analysis and design improvement5.4 Handling accuracy and design optimizationIf dynamic loads are increased, it might deteriorate the accuracy of the precision transfer motion due to deflection and deformation of major structural components 6. Fig. 13 shows the vertical deflections at the tip points of the fingers for the baseline design of the 8G-Telecscopic LTR.The tip deflection of the original design of the LTR was 42 mm. This exceeds the design specification requirement of 10 mm for the LCD fabrication process,and may be the cause of the collision between cassette and robot hands. The cause of the deflection was that the robot structure was very large and heavy. As a result, the deflection must be reduced and the transfer accuracy improved by using the dynamic simulation and optimized design techniques. To reduce the dynamic deflection, a thin-tapered circular plate, what we called a liner, was used, as shown in Fig. 14.The combination of the three liners thickness is very important to reduce the deflection and to optimize the transfer accuracy. So we used dynamic simulations and D.O.E (Design of experiment) for optimization. Fig. 15 shows the proposed simulation methodology which can be used to minimize the deflection at the tip of the finger. The object function was minimization of the differences of the vertical z-displacement of 4-points in Fig.13. The used D.O.E table was a central composite design table with 3-levels and 3-factors 7. Table 2 shows the regression analysis result (ANOVA table).Through the response surface model calculated from the regression analysis 7, the optimized liner thickness was t1=0.50, t2=0.48, t3=0.78 mm. The simulation results for the optimized variable (liner thickness) are shown in Fig. 16. The deflection was reduced only to 5.8 mm. But 42 mm deflection occurred in the baseline design as shown in Fig. 13.An experimental test using the laser tracker was carried out to validate the optimized simulation result.As shown in Fig. 17, the experimental result was about 6.1mm.The simulation results of dynamic deflection were very similar to the test results. This means that we reinforced the structural stiffness without any additional expense.Fig. 13. Vertical deflection of the fingers for baseline designFig. 14. Robot arm and liner (thin circular plate).Fig. 15. Process for design variable optimization.Table 2. ANOVA table for optimization. Fig. 16. Optimized design result using dynamic simulation and D.O.E.6. ConclusionsA computer simulation methodology was presented for vibration and fatigue analysis of the LTR system.Variable amplitude multi-axial loading conditions can be generated to investigate any structural deflection, vibration, and dynamic stress. Flexible bodies were modelled by using component mode synthesis technique.To represent joint compliance and
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