大型回轉支撐套圈端面加工翻轉裝置設計7張CAD圖,大型,回轉,支撐,端面,加工,翻轉,裝置,設計,CAD 設計（XX）任務書 Ⅰ、畢業(yè)設計（論文）題目： 大型回轉支撐套圈端面加工翻轉裝置設計 Ⅱ、畢業(yè)設計（論文）工作內容（從專業(yè)知識的綜合運用、論文框架的設計、文獻 資料的收集和應用、觀點創(chuàng)新等方面詳細說明）： 翻轉裝置是工業(yè)生產中的重要組成部分，它可以顯著減輕工人的勞動強度，改善勞動條件，保證產品質量，實現(xiàn)安全生產，對提高生產的自動化水平和提高勞動生產率具有重要意義。本課題擬針對風力發(fā)電、軍工雷達、醫(yī)療機械等相關行業(yè)對回轉支承加工精度要求高的特點，開展回轉支承端面加工翻轉裝置的設計工作。 本課題從翻轉裝置的方案選擇、翻轉裝置中的夾緊液壓缸的設計、缸筒和活塞桿的校核、機架的校核、翻轉液壓缸的設計、翻轉過程中用到的液壓回路的設計等以及簡單介紹三維軟件 Solidworks2014，并利用 Solidworks2014 建立各個模型， 并進行了裝配表明設計的翻轉裝置滿足工作要求。 （一）設計說明書內容1.總論部分 A. 課題研究的背景和研究意義，通過對翻轉裝置的比較和選擇對翻轉裝置進行結 構設計。 B. 制定研究方案 C．設計要求，主要技術參數(shù)。2 主體部分 主要是基于翻轉裝置的研究最終實現(xiàn)對的研究，最終實現(xiàn)對翻轉裝置的控制。論文具體研究的控制論文具體研究內容如下： A. 翻轉裝置 總體設計方案 以液壓驅動方式為出發(fā)點對翻轉裝置 進行設計。先由回轉支承加工藝特點說明進行設計。先由回轉支承加工藝特點說明使用回轉支承的必要性，再根據(jù)所加工最大回轉支承尺寸，確定作臺的所加工最大回轉支承尺寸，確定作臺的設計所需的夾緊液壓缸 ，選擇合適的翻轉，確定機架的尺寸。 B. 液壓傳動系統(tǒng)分析 簡單介紹控制系統(tǒng)為液壓驅動，選擇合適的同步回路以及夾緊回路，還有翻轉剛的回路。 C. 三維建模 對設計的內容進行三維建模，并對各個零件進行裝配。 3 專題部分 回轉支承的設計：根據(jù)課題給定的回轉支承的范圍,選擇回轉支承的最大尺寸進行設計。 卡爪和轉盤的設計：根據(jù)回轉支承的尺寸來確定卡爪和轉盤的尺寸，在根據(jù)工作的情況來設計軌道形狀以及尺寸。 機架的設計：設計出機架的形狀以及尺寸，再進行校核使其滿足工作需要。夾緊缸的設計：根據(jù)回轉支承的重量選擇合適的夾緊液壓缸，并進行夾緊液 壓缸各個零件的設計。例如活塞桿，缸筒等的設計。 翻轉缸的設計：根據(jù)工作情況選擇一個合適的雙作用液壓缸。 液壓回路的設計：根據(jù)工作的情況，選擇合適的同步回路以及夾緊回路，還有翻轉剛的回路。 各個零部件的建模和裝配：用 solidworks2014 對翻轉裝置的各個零部件進行建模，然后把各個零件裝配在一起。 4. 摘要與翻譯 5. 目錄與參考資料 設計說明書的書寫應清楚、工整，有條件的話，全部用電腦打印為佳。 （二）繪圖內容 對各個零部件用 solidworks 進行三維建模，并裝配。 （三）外文資料翻譯（中文譯文不少于 5000 漢字）。 Ⅲ、進度安排： 2014 年 10 月 20 日～2013 年 11 月 9 日（3 周）：選擇題目，收集材料，聯(lián)系落實畢業(yè)實習單位，填寫畢業(yè)設計任務書； 2014 年 11 月 10 日～2013 年 12 月 7 日（4 周）：布置任務，明確目標、制定計劃，確定初步畢業(yè)設計方案； 2014 年 12 月 8 日～2015 年 1 月 4 日（4 周）：深化初步方案，結合畢業(yè)實習加深對畢業(yè)設計方案的認識； 2015 年 1 月 5 日～2015 年 1 月 16 日（2 周）：學生畢業(yè)設計方案進一步完善； 2015 年 1 月 17 日～2015 年 3 月 1 日（6 周）：繼續(xù)前期工作； 2015 年 3 月 2 日～2015 年 5 月 17 日（11 周）：學生全部返校，進行畢業(yè)設計計算、繪圖，編制畢業(yè)設計說明書，完成畢業(yè)設計工作任務（2015 年 3 月 30 日～2015年4 月 5 日接受學校畢業(yè)設計期中檢查）； 2015 年 5 月 18 日～2015 年 5 月 31 日（2 周）：畢業(yè)成果預提交、修改、評閱、答辯。 Ⅳ、主要參考資料： (1) 王化清.大型工件的翻轉設備的設計與應用［J］．金屬加工冷加工,2O10（1）： 42-45 (2) 孫學平.一種工件翻轉裝置的通用設計方法［J］．機械設計，2006(1):123-124 (3) 孔偉明.底盤鏈式翻轉裝置的方案設計［J］.客車技術與研究，2001(1):23-25 (4)孫學平.一種工件翻轉裝置的通用設計方法［J］．機械設計，2006(1):123-124 (5)毛平準主編.互換性與測量技術基礎[M].北京：機械工程出版社，2005 (6)李壯云主編.液壓元件與系統(tǒng)[M].北京：機械工業(yè)出版社，2005 (7)曾億山．液壓與氣傳動 [M] ．合肥：工業(yè)大學出版社， 2008. (8) 曹玉寶.工件翻轉裝置液壓傳動系統(tǒng)設計［J］.機床與液壓,2011(4):74-77 (9) 曹玉寶.自動化生產線工件翻轉裝置設計［J］.機械傳動，2010(9):80-85 指導教師：（簽名： ）， 年 月 日 學生姓名：（簽名： ），專業(yè)年級： 11 機械工程 系負責人審核意見（從選題是否符合專業(yè)培養(yǎng)目標、是否結合科研或工程實際、綜合訓 練程度、內容難度及工作量等方面加以審核）： 專業(yè)負責人簽字： ， 年 月 日 大型回轉支撐套圈端面加工 翻轉裝置設計 1回轉支撐的介紹 回轉支承在現(xiàn)實工業(yè)中應用很廣泛，被人們稱為：“機器的關節(jié)”，是兩物體之間需作相對回轉運動，又需同時承受軸向力、徑向力、傾翻力矩的機械所必需的重要傳動原件。隨著機械行業(yè)的迅速發(fā)展，回轉支承在船舶設備、工程機械、輕工機械、冶金機械、醫(yī)療機械、工業(yè)機械人、隧道掘進機、旋轉舞臺等行業(yè)得到了廣泛的應用。 2課題研究的來源 由于大型回轉支承體積大，零件截面積小，加工精度高，工序長，易變形，因此加工的難度增大。本課題擬針對風力發(fā)電、軍工雷達、醫(yī)療機械等相關行業(yè)對回轉支承加工精度要求高的特點，根據(jù)馬鞍山方圓回轉支撐股份有限公司現(xiàn)有加工條件，開展回轉支撐套圈端面加工翻轉設計工作。 3課題研究的背景 回轉支承端面套圈在機械加工過程中常常需要進行翻轉，由于工件慣性大在翻轉的過程中會產生較大的沖擊，因此存在很大的安全隱患，所以需要設計合理的翻轉裝置已實現(xiàn)工件的平穩(wěn)翻轉。 傳統(tǒng)的機械零件加工方法,由于生產工藝落后,工序分散,工件翻轉由人力手工完成,從而帶來生產效率低、工人勞動強度大、產品質量不穩(wěn)定、生產成本增加等而采用翻轉裝置加工制造機械零件,可以將所有生產環(huán)節(jié)融合,其中的工件翻轉由自動化翻轉裝置完成,可大幅度減輕工人勞動強度,提高生產效益,改善生產環(huán)境,提高產品質量。工件翻轉裝置是自動化生產線的重要組成部分,其設計的好壞直接影響整個自動化生產線的工作水平,因而對工件翻轉裝置進行合理的設計就顯得極為重要。自動化制造系統(tǒng)的類型很多,不同的制造系統(tǒng),工件翻轉的實現(xiàn)形式也不同,針對少品種、大批量生產的剛性自動線,由于各設備按一定的生產節(jié)拍生產,工件順序通過各個工作位置,自動完成零件預定的全部加工過程和部分檢驗過程,因而對于工件的翻轉也要求能夠嚴格適應這種節(jié)奏。 生產中應用翻轉裝置可以提高生產的白動化水平和勞動生產率，可以減輕勞動強度,保證產品質量,實現(xiàn)安全生產，尤其在高溫、高壓、低溫、低壓、粉塵、易爆、有毒氣體和放射性等劣的壞境中，它代替人進行正常的工作，意義更為重大。因此，翻轉裝置在工業(yè)生產中廣泛應用。 4課題研究的意義 1）可以提高生產過程的自動化程度。應用翻轉裝置，有利于提高生產的自化程度，從而可以提高勞動生產率，降低生產成本，加快實現(xiàn)工業(yè)生產機械化和自動化的步伐。 2）可以改善勞動條件、避免人身事故。在有些場合中，用人手直接工件翻轉是有危險或根本不可能的。而應用翻轉裝置即可部分或全部代替人安全地完成作業(yè)，大大地改善了工人的勞動條件。 3）可以減少人力，便于有節(jié)奏的生產。應用翻轉裝置代替人手進行工作，這是直接減少人力的一個側面，同時由于應用翻轉裝置可以連續(xù)地工作，這是減少人力的另一個側面。因此，在自動化機床和綜合加工自動生產線上目前幾乎都設有翻轉裝置，以減少人力和更準確地控制生產的節(jié)拍，便于有節(jié)奏地進行生產。 參考文獻： [1] 孫學平.一種工件自動翻轉裝置的通用設計方法[J].機械工程師，2006（01）：124. [2] 林順洪,朱新才,李長江等.軋輥軸承座液壓翻轉裝置設計[J].機械工程師,2005,(7):98-99. [3] 曹玉寶.自動化生產線工件翻轉裝置設計［J］.機械傳動，2010(9):80-85 [4]李長江,林順洪,朱新才.大型軸承座翻轉裝置的虛擬樣機設計[J].煤礦機械，2008,(04):199-201. [5] 劉海影. 工件180度翻轉裝置的設計[J]工業(yè)技術，2013（08） [6] 王化清.大型工件的翻轉設備的設計與應用［J］．金屬加工冷加工,2O10（1）：42-45 關于課題《大型回轉支承套圈端面加工翻轉裝置設計》的文獻綜述 回轉支承在現(xiàn)實工業(yè)中應用很廣泛，是兩物體之間需作相對回轉運動，又需同時承受軸向力、徑向力、傾翻力矩的機械所必需的重要傳動原件。隨著機械行業(yè)的迅速發(fā)展，回轉支承在船舶設備、工程機械、輕工機械、冶金機械、醫(yī)療機械、工業(yè)機械人、隧道掘進機、旋轉舞臺等行業(yè)得到了廣泛的應用?；剞D支承端面套圈在機械加工過程中常常需要進行翻轉，由于工件慣性大在翻轉的過程中會產生較大的沖擊，因此存在很大的安全隱患，所以需要設計合理的翻轉裝置已實現(xiàn)工件的平穩(wěn)翻轉。工件在制造加工中需要經常翻身，因此根據(jù)不同工件的結構特點設計專用翻轉設備給操作者帶來了大的方便，在大幅度地提高生產效率的同時確保了安生產。由此可見，翻轉設備是工件批量生產必不可少的專用裝備。大型回轉支承又稱轉盤軸承或大型軸承，是一種能夠承受綜合載荷的大型軸承，可以同時承受較大的徑向載荷、軸向載荷和傾翻力矩，轉盤軸承廣泛用于起重機械、港口機械、船舶機具以及其他方面的大型回轉裝置上。由于大型回轉支承體積大，零件截面積小，加工精度高，工序長，易變形，因此加工的難度增大。 （1）一種工件自動翻轉裝置的通用設計方法[1] 在自動化生產線中, 常常會遇見一種要求工件翻轉的情況。比如在傳輸線上工件的初始狀態(tài)為臥式狀態(tài), 現(xiàn)在要求其改變?yōu)檎玖顟B(tài)。為解決這個問題, 設計了一簡單易行的翻轉裝置。其工作原理圖如圖1-1所示。 傳輸方向為垂直紙面由里向外。軸 6 裝在夾爪 5 中,通過軸承 8 裝配連接能自由轉動。初始狀態(tài)時, 平行氣爪2處于張開狀態(tài), 氣缸 3 伸出, 平行氣爪 2 收縮夾緊工件 1,氣缸 3 縮回, 抓取工件上升, 工件在重力作用下自動翻轉成立式狀態(tài)。抓取點取在工件重心前方時, 工件翻轉后上面朝后, 若抓取點取在工件重心后方時, 工件翻轉后上面朝前。平行氣爪 2 張開, 工件 1 落下并處于立式狀態(tài)。這種裝置設計時, 需要選好抓取工件時的抓取點, 以保證工件能順利翻轉, 并且準確計算好氣缸 3 的行程, 使工件距下底面高度為 2 mm, 以保證工件落下時不會摔倒。根據(jù)工件尺寸的大小不同, 可以選擇不同行程的平行氣爪 2和不同行程的氣缸 3 適應不同尺寸的工件, 達到翻轉的目的。通過多條生產線的使用, 這種裝置運行效果良好, 用戶都很滿意。其工作原理已經在自動化生產線中被廣泛地采用。 圖1-1 簡易翻轉裝置 小結：本方案應用優(yōu)化設計理論, 建立的以凸輪基本尺寸最小值為目標函數(shù)、壓力角及接觸強度等性能要求為約束條件所構成的優(yōu)化設計數(shù)學模型是可行的, 對凸輪機構的設計有一定的應用價值，為在傳輸線上工件的初始狀態(tài)為臥式狀態(tài), 改變成站立狀態(tài)設計了一種簡單易行的翻轉裝置。 (2) 輥軸承座液壓翻轉裝置[2] 設計如圖1-2所示，為軋輥軸承座液壓翻轉裝置總體布置圖。該裝置主要由翻轉體、支承裝置、支撐A、支撐B、行程開關、翻轉油缸等組成。該裝置采用翻轉油缸水平安放,翻轉油缸的安裝、檢修將非常方便。 圖1-2所示為立式翻轉( 軸承中心線由水平轉向垂直) 的初始位置。工作原理是：首先利用車間的起重機將從軋輥上拆下的軋輥軸承座吊放在翻轉臺上, 然后啟動軋輥軸承座翻轉裝置將軋輥的軸承座進行90°的立式翻轉（軸承中心線由水平轉到垂直）,再用起重機將翻轉完的軋輥軸承座吊放到指定位置對軸承座內的軸承進行檢修, 至此完成了一個工作輥/支承輥軸承座的翻轉工作。當軸承座內的軸承檢修完畢后對軋輥的軸承座進行90 的臥式翻轉（軸承中心線由垂直轉向水平）時工作順序與此相反。圖1-3所示為軋輥軸承座液壓翻轉裝置液壓系統(tǒng)。系統(tǒng)由一臺恒壓變量泵供油,常態(tài)下電磁溢流閥斷電,液壓泵卸荷使電機空轉。當電磁溢流閥得電時,液壓泵建立起壓力,電磁換向閥左邊得電,壓力油進入有桿腔,在壓力油作用下,液壓缸活塞退回從而實現(xiàn)將軋輥的軸承座進行90°的立式翻轉。同理,當電磁溢流閥得電時,液壓缸活塞推出,實現(xiàn)將軋輥的軸承座進行90°的臥式翻轉。兩只翻轉油缸采用剛性連接保持同步。為了使工作平穩(wěn),采用調速閥進行速度調節(jié)。為了減小由于軸承座和翻轉體的重心位置變化引起負值負載而產生慣性沖擊, 采用了平衡閥。 小結：本軋輥軸承座液壓翻轉裝置能平穩(wěn)、高效地對軋機的軋輥軸承座進行 90°的立式翻轉和90°的臥式翻轉。軋輥軸承座液壓翻轉裝置對工作輥、支承輥軸承座進行的90°翻轉，能拆卸和安裝軸承座內的軸承。該裝置具有自動化程度高、生產效率高運行平穩(wěn)等特點。 圖1-2 軋輥軸承座液壓翻轉裝置總體布置圖 1-翻轉油缸；2-翻轉油缸支座；3-行程開關；4-支承A； 5-軋輥軸承座；6-支承裝置；7-翻轉體；8-支承B；9-設備基礎 圖1-3軋輥軸承座液壓翻轉裝置液壓系統(tǒng) （3）自動化生產線工件翻轉裝置設計[3] 柴油機缸蓋自動化生產線中，由于缸蓋在加工過程中要進行多面加工，因此要求對工件進行翻轉。其工作順序如下：執(zhí)行機構下降一夾緊工件一執(zhí)行機構上升一將工件翻轉180°一執(zhí)行機構下降一松開工件一執(zhí)行機構上升，一個循環(huán)完成，循環(huán)周期為20s?？傮w結構如圖1-4所示，執(zhí)行機構1下降到預定位置，由夾緊液壓缸(圖中未畫出)驅動夾緊工件，然后上升到一定位置，翻轉液壓缸(圖中未畫出)工作，即可將工件翻轉。 1-執(zhí)行機構；2-立柱；3-橫梁；4-升降液壓缸； 5-充液系統(tǒng)；6-鎖緊螺母；7-調整螺母；8-底座 圖1-4 工件翻轉裝置總體結構 圖1-5　執(zhí)行機構1-4剖視圖 其液壓原理圖如圖1-6所示，工作原理在這里就不再過多敘述。 圖1-6 液壓原理圖 1-過濾器；2-雙連葉片泵；3-雙連葉片泵；4-油箱；5-溢流閥； 6-溢流閥；7-電磁換向閥；8-單向節(jié)流閥；9-升降液壓缸；10-夾緊液壓缸； 11-單向節(jié)流閥；12-電磁換向閥；13-翻轉液壓缸；14-電磁換向閥 小結：該裝置具有結構簡單、液壓傳動平穩(wěn)慣性小，以及易于控制等優(yōu)點，廣泛適用于箱體類和其他非回轉類零件的翻轉加工。 （4）大型軸承座翻轉裝置的虛擬樣機設計[4] 該裝置主要由翻轉體、支撐裝置和翻轉油缸等組成。翻轉油缸水平安放,翻轉油缸的安裝、檢修非常方便如圖1-7為軸承座液壓翻轉裝置原理圖，圖1-7所示為立式翻轉(軸承中心線由水平到垂直)的初始位置。工作原理是:先利用車間的起重機將軸承座吊放在翻轉臺上,然后啟動座翻轉裝置將軸承座進行90°的立式翻轉(軸承中心線由水平→垂直),再用起重機將翻轉完的軸承座吊放到指定位置對軸承座內的軸承進行檢修,至此完成了一個軸承座的翻轉工作。當軸承座內的軸承檢修完畢后對軸承座進行90°的臥式翻轉(軸承中心線由垂直→水平)時工作順序與此正好相反。 圖1-7大型軸承座翻轉裝置工作原理圖 1. 翻轉油缸支座　2.翻轉油缸　3.翻轉體　4.支撐裝置5.軸承座 圖1-8軋輥軸承座翻轉裝置的整體模型 小結：該翻轉油缸水平安放,翻轉油缸的安裝、檢修非常方便，能夠拆卸、安裝軸承座內的軸承。該裝置具有自動化程度高、生產效率高和運行平穩(wěn)等特點。 （5）工件180度翻轉裝置的設計[5] 該裝置傳輸方向由左向右。動力軌道裝在三個轉盤中，分別由兩只電動滾筒帶動；轉盤1、3起支承并固定動力軌道的作用，轉盤2通過電機帶動鏈輪鏈條（未畫出轉動；上下各有兩只液壓缸，在旋轉過程中起夾緊作用。初始狀態(tài)時，上下兩處液壓缸處于非工作狀態(tài)；軌道1在電動滾筒帶動下圖1-9工作，工件由左向右進入翻轉裝置，當工件運行到正確位置，軌道側面光電開關工作，電動滾筒停止工作。 這時頂升液壓缸頂起工件約為5mm，然后夾緊液壓缸夾緊工件；接著電機工作,帶動鏈輪鏈條旋轉過180度；由兩側接近開關控制旋轉的角度.翻轉結束后，上下兩液壓缸縮回，由工人對工件進行檢驗，檢驗完畢，軌道 2工作，工件由軌道2輸送出去；電機帶動鏈輪鏈條反向轉動工件180度，再進行對下一個工件的操作。 工件翻轉采用鏈輪鏈條結構來實現(xiàn)如圖1-10，鏈輪鏈條傳動是一種工業(yè)上應用非常廣泛的機械結構，其中鏈條的兩端與中間轉盤的相連，電機帶動鏈輪旋轉（未畫出），中間轉盤在鏈條的牽引下即可進行轉動，從而帶動兩側轉盤轉動，實現(xiàn)對工件的翻轉。 圖1-9翻轉裝置圖 圖1-10鏈輪鏈條結構圖 液壓系統(tǒng)原理圖如圖1-11所示。三位四通電磁換向閥分別控制升降缸3夾緊缸的運動方向。單向節(jié)流閥用于回油節(jié)流調速。執(zhí)行機構由驅動升降的液壓缸3驅動夾緊松開的液壓缸組成。單向節(jié)流閥還用于平衡位置升降缸及其工作機構的自重以防下滑。液壓及控制系統(tǒng)的工作原理見圖1-11，在這里就不過多敘述。 圖1-11液壓控制圖 小結：設計的該工件翻轉裝置經在客戶柴油機缸體自動化生產線應用，達到了預期的設計要求。利用鏈輪鏈條傳動結合液壓傳動系統(tǒng)，并與可編程控制器和計算機控制相結合，很好地實現(xiàn)了工件的翻轉。該裝置具有結構簡單3液壓傳動平穩(wěn)慣性小，運行平穩(wěn)，效果良好，以及易于控制等優(yōu)點，廣泛適用于箱體類和其他非回轉類零件的翻轉加工，在自動化生產中具有廣闊的應用前景。 由于國內外對翻轉裝置的研究有許多，這里只是介紹幾種常用方法，其它翻轉裝置機構型式在這不過多敘述。 參考文獻： [1] 孫學平.一種工件自動翻轉裝置的通用設計方法[J].機械工程師，2006（01）：124. [2] 林順洪,朱新才,李長江等.軋輥軸承座液壓翻轉裝置設計[J].機械工程師,2005,(7):98-99. [3] 曹玉寶.自動化生產線工件翻轉裝置設計［J］.機械傳動，2010(9):80-85 [4]李長江,林順洪,朱新才.大型軸承座翻轉裝置的虛擬樣機設計[J].煤礦機械，2008,(04):199-201. [5] 劉海影. 工件180度翻轉裝置的設計[J]工業(yè)技術，2013（08） [6] 王化清.大型工件的翻轉設備的設計與應用［J］．金屬加工冷加工,2O10（1）：42-45 Acta Montanistica Slovaca Ronk 13 (2008), slo 1, 152-157 Hydraulic Press with LS System for Modelling of Plastic Working Operations Janusz Pluta1 Hydraulick lis so systmom LS pre modelovaniu procesov plastickch deformci At first, the paper describes destination of the presented hydraulic press. Next, the substance of load sensing (LS) systems operation was introduced, and electro-hydraulic system of this type, installed in laboratory hydraulic press, was described. The control and measurement circuit of the device was also described, and exemplary test results obtained during plastic working operations on soft non-ferrous alloys were presented. Key words: electro-hydraulic system, hydraulic press, load sensing system, plastic working operation Introduction Press with hydrostatic drive belongs to group of units, which are widely used in plastic working of materials. Presented in article hydraulic press makes an example of modern solution application in electro-hydraulic technology domain for getting of specified functional and operational unit properties. Such a press is intended for wide range research leading, especially plastic working operations on non-ferrous alloys physical modelling in one of laboratories at AGH-UST in Krakow. Operations of upsetting and compressing, forging modelling, hot and cold extrusion are conducted on press. Experiments are carried out mainly on soft metals such as: aluminium, tin, lead and their alloys. Interesting powder metallic materials extrusion process is also in research project. For sake of nature, number and range of conducted investigations, simple servicing and possibility of manual or automatic cycle work is required from the press. Simultaneously assurance of following job parameters and fulfilment of basic requirements is needed: overcame loads range: 0 3000 kN, plunger velocity range 5 200 mm/min, possibility of stepless adjustment and plunger motion velocity stabilization regardless of applied loads, possibility of long-lasting work with high experimentation frequency, energy losses minimization in hydraulic system, possibility of measurement and data logging of selected physical values. Analyzing different kinds of control used in hydrostatic systems, were made decision about constructing a press with load sensing” type electro-hydraulic control system. Construction, functioning and properties of load sensing” systems is described in next chapter. The substance of the hydraulic LS system operation As an aim of loosed power minimization in hydraulic systems or obtaining precision control of hydraulic receiver velocity more frequently are used systems in which supply pressure generated by hydraulic pump is adapting to current receiver load in the way of holding constant pressure drop on restrictor controlling receiver working. In English literature these systems are known under the name of load sensing” systems (Ebertshuser, 1989; Pluta, 2002), in German lastdruckkompensation” or lastkompensation” 1. Basing on definitions written in (Ebertshuser, 1989; Osiecki, 1998; Stryczek, 1995; Makowski, 2001), in further considerations by Load Sensing system (in abbreviation, LS system), in most general sense, will be understand as hydraulic system in which there is a feedback from load and which automatically adapting instantaneous circulation (or circulations) working parameters to receiver (or receivers) requirements or setting work conditions. Construction and properties of individual LS systems varietys depends among other things on: kind of hydraulic circulation (open, closed, semi-closed), kind of hydraulic pump (fixed or variable displacement pump) and kind of used throttle valve construction. One 1 dr. In. Janusz Pluta. Department of Process Control, Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, Krakow, Poland, plutianagh.edu.pl (Recenzovan a revidovan verzia dodan 28. 11. 2007) 152 Acta Montanistica Slovaca Ronk 13 (2008), slo 1, 152-157 of the main aim of construction and using the LS systems is desire for elimination or at least minimization of energy losses. For achievement of this aim three kinds of controllers are used in LS systems: 2: type I controller, working according to p = const principle, which eliminate power losses due to excessive output flow of hydraulic pump, type II controller, working according to p = const principle, which eliminate power losses due to excessive output flow of hydraulic pump and minimizing losses due to excessive forcing pressure of hydraulic pump, type III controller, working according pQ = const principle, which besides realized by type II controller tasks, fulfil role of power consumed by hydraulic pump limiter. Type I controller (Fig. 1) consists of: variable displacement pump 1, cylinder with spring return 2 controlling output flow of hydraulic pump, pressure compensatory valve 3 and safety-valve 4. Controller working consists in that if output flow of hydraulic pump is bigger than receiver requirements and as a result of that increasing of pressure in working line follow over setting up value on valve 3, so after that this valve is immediately open connecting working line with cylinder 2, which decrease output flow of hydraulic pump to level of receiver 5 demanding. Type II controller (Fig. 2) consists of variable displacement pump 1 controlled by cylinder 2, differential valve 3 and overflow valve 4. Its working principle is common to type I controller. Those controller holds constant pressure drop p on throttle 5, came 5% of maximum pressure value in system. However pressure in working line of hydraulic pump is variable in this system and is depending on receiver load. Fig. 1. Hydraulic scheme of LS system with type I controller. Fig. 2. Hydraulic scheme of LS system with type II controller. Type III controller limits mechanical energy taken from driving motor by hydraulic pump adapting output flow of pump to pressure in working line according to hyperbolic characteristic. Moreover type III controller includes parts consisting to type II controller. Two fundamental possibilities of LS system idea realization are known, which allow for getting completely distinctness drive properties. They result from that, is hydraulic drive supplied from source of constant flow rate or from variable displacement pump equipped with pressure controller (Osiecki, 1998; 153 Janusz Pluta: Hydraulic Press with LS System for Modelling of Plastic Working Operations Stryczek, 1995). Throttle valves (mostly special construction throttling control valves) are essence of those systems. In connection with two and three way differential valves they form systems, which realize active throttling principle. It consists in that differential valves (named sometimes as compensatory valves (Ebertshuser, 1989; Osiecki, 1998; Stryczek, 1995) which automatically adapting flow rate of liquid flux reaching hydraulic receiver in dependence of pressure drop value setting up on throttle valve. Setting up of those drop can be done manually or by use of electro-hydraulic control. Possibility of precise hydraulic receiver velocity control independently from load is the most essential advantage of LS systems with fixed displacement pump (Fig. 3). From energetic point of view those systems didnt give any advantages in comparison with conventional throttling control systems supplied by fixed displacement pump. Biggest decrease of energy losses can be obtained by connecting throttling control with volumetric control i.e. variable displacement pump equipped with pressure regulator (Fig. 2). Throttling valve 6 works with differential valve reacting on pressure difference p together. In this manner structural volumetric loss Nv is eliminated but structural hydrodynamic loss Nh connected to flow resistance p through throttling control valve is appearing. System of such type was a starting point for studying a press with electro-hydraulic load sensing” system. The electro-hydraulic LS system of the press Characterized hydraulic press includes mechanical and hydraulic parts, measurement control system and electric supply system. Mechanical part consist of four vertical columns connecting two horizontal traverse: lower and upper (Fig. 4). Hydraulic plunger cylinder collar which is press driving part is mounted on lower traverse. Those cylinder with connected to them hydraulic supplying and control unit makes hydraulic part of the press. For constructing of pumping engine hydraulic and electro-hydraulic control devices which cooperates with suitable sets of measurement and control system were used. Most of controlling tasks were assigned to electrical part of unit. Working substance of studied hydraulic system of the press and collaborating measurement and control system is the same as hydraulic LS system with type II controller presented at Figure 3. But for the sake of kind and working of used elements more precise name for constructed system will be electro-hydraulic load sensing system. In place of manually controlled throttling valve 6 (Fig. 2), two-way electro-hydraulic proportional valve 6 (Fig. 5.) is used. Fig. 3. LS system scheme with fixed displacement pump Fig. 3. LS system scheme with fixed displacement pump. Pumping unit with hydraulic pressure controller is replaced with pumping unit with fixed displacement pump 1 drive by asynchronous motor 2 working with frequency changer. On inlet and outlet of proportional valve 2 pressure transducers 3.1, 3.2 which measure of pressure difference on this valve made possible were mounted. In result of changing the load acting on plunger of hydraulic cylinder 5 pressure p2 is changing in outlet of valve 6. For holding constant pressure drop p = p1 p2 on this valve what is a condition of plunger constant velocity preservation with a change of pressure p2 adequately pressure p1 must change. Inother words change of pressure p1 must go after changes of pressure p2. This task is realized by pumping unit which during changes of output flow affect on pressure p1 change. Output flow change is gained by pump shaft rotational speed change. Its possible due to frequency changer working with asynchronous motor which drives the pump. Thanks to that pumping unit properties can be obtained as in hydraulic system with type II controller (Fig. 2). For assurance of pump correct work with different rotational speed of rotor besides construction type, place and manner of installing is very important factor. Especially the thing is that suction of hydraulic fluid have good conditions. For most pumps producers gives in technical data minimal value of rotational speed in limits of 500 to 900 rpm with suitable pressure in suction line. It means that only above this speed we can change pump output flow up to acceptable velocity for example 3000 rpm. However, if very good pressure and flow conditions in suction line will be assured, rotational speed for some kinds of pumps can be reduced significantly with obtaining correct work. Selection of pump driving motor is important too. In significant range of rotational speeds starting below half of motors nominal value, asynchronous motor with additional (independent) cooling can be used. Parameters of used frequency changer as especially nominal power are important as well. For assurance of correct measure and control system work, frequency changer should be equipped with filter against sensor work interference. 154 Acta Montanistica Slovaca Ronk 13 (2008), slo 1, 152-157 During work of described press three kinds of work state are appear: motion of plunger with setting velocity which is a working motion, during which overcoming a resistance to motion connected mainly with plastic working process modelling, standstill of plunger designed for making auxiliary actions, lowering of plunger under the die block weight which is placed on plunger. Structure of electro-hydraulic LS system appear only during working motion. During lowering of plunger with die block valve 6 is closed, and directional control valve 7 is in open position. Signal from those directional control valve cause in opening valve 8, through which hydraulic liquid leaves cylinder 5 forced by plunger and die block outside into the tank. During this phase of work pumping unit works with minimum output flow essential for getting valve 8 opening pressure. During standstill pumping unit output flow is take down to zero but asynchronous motor 2 with frequency changer is in stand-by mode. b )a ) Fig. 4. The press: a) front view, b) rear view. During work of described press three kinds of work state are appear: motion of plunger with setting velocity which is a working motion, during which overcoming a resistance to motion connected mainly with plastic working process modelling, standstill of plunger designed for making auxiliary actions, lowering of plunger under the die block weight which is placed on plunger. Structure of electro-hydraulic LS system appear only during working motion. During lowering of plunger with die block valve 6 is closed, and directional control valve 7 is in open position. Signal from those directional control valve cause in opening valve 8, through which hydraulic liquid leaves cylinder 5 forced by plunger and die block outside into the tank. During this phase of work pumping unit works with minimum output flow essential for getting valve 8 opening pressure. During standstill pumping unit output flow is take down to zero but asynchronous motor 2 with frequency changer is in stand-by mode. 155 Janusz Pluta: Hydraulic Press with LS System for Modelling of Plastic Working Operations Fig. 5. Scheme of press with electro-hydraulic LS system: 1 pump, 2 electrical motor, 3.1 and 3.2 pressure transducers, 4 relief valve, 5 hydraulic cylinder, 6 2/2 proportional flow control valve, 7 3/2 directional control valve, 8 controlled check valve, 9 displacement transducer, 10 force sensor. The control and measurement system This system is designed for press working control according to programmed algorithms and made measurements and data logging of selected physical quantities. With excluding of sensors system was placed in control box with electrical elements and components supplying system. The following main systems were used: programmable logic controller equipped with analogue input and output modules, programmable operating panel, frequency converter of vector control. In press sensors and measuring converters were mounted from which part were used in electro-hydraulic control of LS system, other were used for physical quantities measurement, what make possible determining of made plastic working operations characteristics. There are (Fig. 5): piezoelectric pressure transducers 3.1 and 3.2, contactless magnetostrictal position and linear velocity transducer 9 of plunger (die block), induction proportional valve 6 slide position sensor 6.1, compressing force strain gauge sensor 10 working with suitable transducer. The controller software was realized by using Mitsubishi MELSEC MEDOC programme. The software, recorded as a ladder diagram is composed of the main programme and the subroutines. In the main programme the following functional blocks were distinguished: work parameter fixing for particular elements of hydraulic and control and measuring system, as initial and limit values and filtration coefficients of measured signals, parameter fixing which initialize the work of measuring and control modulus, read-out of the measured values together with their filtration, collaboration with operation panel (option selection from MAIN MENU or from the control algorithm of functional keys), force measuring system calibration, tarring of force and distance measuring system, data transmission to PC computer, control algorithm selection. Particular control algorithms were recorded as subroutines realizing following research procedures: manual control, upsetting, compressing, forging, extrusion. Operating panel was programmed by using the object MAC Programmer + Packet. Particular screens projector aspect was designed in separate programme blocks, whereas their mutual connections between blocks were realized by using jump function produced on the screens and by functional keys. 156 Acta Montanistica Slovaca Ronk 13 (2008), slo 1, 152-157 Sample characteristics First experiments on the presented device were conducted with the test pieces made of lead. Sample characteristics were determined by press control and measuring system during test of lead extrusion are presented at Fig. 5. Upper characteristic shows diagram of extrusion force, lower diagram of plunger (die block) displacement. From the test results it can be concluded, that in case of plastic strain of the soft material increase of pressing force is slight at first, then for some time it is very intensive until the maximum value is reached, and after that continuous and rather slow decrease of forces value occurs. During this experiment pressing force of the press did not reach 20 % of its nominal value. 70 80 90 100 110 120 130 1400 200400600time s force kN70 80 90 100 110 120 130 140150 200250300time s displacement mm Fig. 6. Lead extrusion diagrams for plunger velocity 105 mm/min Conclusion The presented device was set up in Faculty of Non-Ferrous Metals, AGH University of Science and Technology, Krakow Poland. Connecting of modern hydraulic technology and electric drives technique with microprocessor technique and modern measurement technique allow constructing of electro-hydraulic press system with properties of LS system. Hydraulic system were constructed from typical elements with high reliability makes simple and easy construction for maintenance. Used in hydraulic press LS system turn out to be useful in practice. A few year reliable work confirm their usefulness and expected functional and exploitation properties. References Ebertshuser, H.: Fluidtechnik von A bis Z. Der Hydraulik Trainer, Band 5. Mannesmann Rexroth GmbH 1989. ISBN 378300243-5. Osiecki, A.: Hydrostatyczny Napd Maszyn. Wydawnictwa Naukowo-Techniczne, Warszawa 1998. ISBN 832042296-5. Pluta, J., Podsiado, A., Sapiski B.: Energooszczdne ukady hydrauliczne. II Midzynarodowa Konferencja Techniki Urabiania 2002. Krakw Krynica, wrzesie 2002, pp. 569 581. ISBN 8391574253. Stryczek, S.: Napd hydrostatyczny, tom II. Wydawnictwa Naukowo-Techniczne, Warszawa 1995. ISBN 8320418283. Makowski, A.: Wykorzystanie odmiany sterowania load sensing w hydraulicznym ukadzie dawieniowym. Hydraulika i Pneumatyka. Dwumiesicznik naukowo-techniczny nr 4/2001, pp. 26-27. Wrocaw 2001. ISSN 15053954 157