液壓英文文獻(xiàn)及翻譯

1、液壓系統(tǒng)(文獻(xiàn)翻譯) 15液壓系統(tǒng)1.緒論液壓站稱液壓泵站，是獨(dú)立的液壓裝置。它是按逐級(jí)要求供油。并控制液壓油流方向、壓力和流量，適用在主機(jī)與液壓裝置可分離的各種液壓機(jī)械上面。用戶在購(gòu)后只要將液壓站與主機(jī)上執(zhí)行機(jī)構(gòu)（油缸或油馬達(dá)）用不同的油管相連，液壓機(jī)械即實(shí)現(xiàn)各種規(guī)定的動(dòng)作與工作循環(huán)。液壓站是由集成塊、泵裝置或閥組合、電氣盒、油箱電氣盒組合而成。各個(gè)部件功能為：泵裝置上裝有電機(jī)和油泵，其是液壓站的動(dòng)力源，能將機(jī)械能轉(zhuǎn)化為液壓油壓力能。閥組合其板式閥裝在立板上，板后管連接，與集成塊的功能相同。油集成塊是由液壓閥及通道體組裝而成。其對(duì)液壓油實(shí)行壓力、方向和流量調(diào)節(jié)。箱是板焊的半封閉容器，上面還裝

2、有濾油網(wǎng)、空氣濾清器等，是用來儲(chǔ)油與油的冷卻及過濾。電氣盒分兩種型式：一種是設(shè)置外接引線的端子板；一種是配置了全套控制電器。液壓站工作原理：電機(jī)帶動(dòng)油泵轉(zhuǎn)動(dòng)，然后泵從油箱中吸油并供油，將機(jī)械能轉(zhuǎn)化為液壓站壓力能，液壓油通過集成塊（或閥組合）實(shí)現(xiàn)方向、壓力、流量調(diào)節(jié)后經(jīng)過外接管路并至液壓機(jī)械里的油缸或油馬達(dá)中，從而控制液動(dòng)機(jī)方向變換、力量的大小及速度的快慢，來推動(dòng)各種液壓機(jī)械做功。(1)液壓的發(fā)展歷程 在我國(guó)液壓（含液力，下同）、氣動(dòng)和密封件工業(yè)的發(fā)展歷程，大致可分成三個(gè)階段，即：在20世紀(jì)50年代初到60年代初是起步階段；60-70年代為專業(yè)化生產(chǎn)體系的成長(zhǎng)階段；80-90年代為快速發(fā)展階段。

3、在其中，液壓工業(yè)始于50年代初從機(jī)床行業(yè)生產(chǎn)的仿蘇的磨床、拉床、仿形車床等液壓傳動(dòng)來起步，液壓元件由機(jī)床廠里的液壓車間生產(chǎn)，自產(chǎn)自用。在進(jìn)入60年代后，液壓技術(shù)應(yīng)用從機(jī)床逐漸推廣到農(nóng)業(yè)機(jī)械與工程機(jī)械等領(lǐng)域，原來附屬于主機(jī)廠里的液壓車間有些獨(dú)立出來，成為液壓件的專業(yè)生產(chǎn)廠。在60年代末、70年代初，隨著生產(chǎn)機(jī)械化的不斷發(fā)展，特別是在為第二汽車制造廠等提供了高效、自動(dòng)化設(shè)備的帶動(dòng)下，液壓元件制造業(yè)出現(xiàn)了不斷迅速發(fā)展的局面，一批中小企業(yè)也開始成為液壓件專業(yè)制造廠。1968年中國(guó)的液壓元件年產(chǎn)量已接近20萬件；而在1973年在機(jī)床、農(nóng)機(jī)、工程機(jī)械等行業(yè)里，生產(chǎn)液壓件的專業(yè)廠已發(fā)展到100余家，其年產(chǎn)量

4、超過100萬件，這樣一個(gè)獨(dú)立的液壓件制造業(yè)已初步形成。于此這時(shí)，液壓件產(chǎn)品已從開始的仿蘇產(chǎn)品發(fā)展為引進(jìn)技術(shù)和自行設(shè)計(jì)相結(jié)合的產(chǎn)品，壓力向中、高壓發(fā)展，開發(fā)了電液伺服閥及系統(tǒng)，液壓的應(yīng)用領(lǐng)域進(jìn)一步擴(kuò)大。而氣動(dòng)工業(yè)的起步比液壓稍晚幾年，到1967年開始才建立氣動(dòng)元件專業(yè)廠，氣動(dòng)元件才開始作為商品生產(chǎn)和銷售。其含橡塑密封、柔性石墨密封和機(jī)械密封的密封件工業(yè)，從50年代初生產(chǎn)普通O型圈、油封等擠壓橡塑密封和石棉密封制品起步，在到60年代初，開始研制生產(chǎn)柔性石墨密封和機(jī)械密封等制品。70年代，原燃化部、一機(jī)部、農(nóng)機(jī)部所屬系統(tǒng)內(nèi)，一批批專業(yè)生產(chǎn)廠開始相繼成立，正式形成行業(yè)，為密封件工業(yè)發(fā)展成長(zhǎng)奠定了基礎(chǔ)。

5、 在進(jìn)入80年代，國(guó)家改革開放的方針指引下，隨著機(jī)械工業(yè)的不斷發(fā)展，基礎(chǔ)件滯后于主機(jī)的矛盾日益突出，引起各有關(guān)部門的重視。為此，原一機(jī)部在1982年組建了通用基礎(chǔ)件工業(yè)局，將原有分散在機(jī)床、農(nóng)業(yè)機(jī)械、工程機(jī)械等的行業(yè)歸口的氣動(dòng)、液壓和密封件專業(yè)廠，統(tǒng)一劃歸為通用基礎(chǔ)件局管理，從而使該行業(yè)在規(guī)劃、投資、引進(jìn)技術(shù)以及科研開發(fā)等方面得到基礎(chǔ)件局的指導(dǎo)和支持。由此進(jìn)入了快速發(fā)展期，其先后引進(jìn)了60余項(xiàng)國(guó)外先進(jìn)技術(shù)，而其中液壓40余項(xiàng)、氣動(dòng)7項(xiàng)，經(jīng)過消化吸收和技術(shù)改造，現(xiàn)均已批量生產(chǎn)，并成為了行業(yè)的主導(dǎo)產(chǎn)品。近年來，行業(yè)加大技術(shù)改造力度，1991-1998年國(guó)家、地方及企業(yè)自籌資金總投入共約20多億元，

6、而其中液壓16億多。經(jīng)過不斷技術(shù)改造和技術(shù)攻關(guān)，一批主要企業(yè)技術(shù)水平進(jìn)一步提高，工藝裝備也得到很大改善，為形成了高起點(diǎn)、專業(yè)化、批量生產(chǎn)打下良好基礎(chǔ)。近幾年來，在國(guó)家多種所有制共同發(fā)展的方針指引下，各種不同所有制的中小企業(yè)迅猛崛起，展現(xiàn)出勃勃生機(jī)。隨著國(guó)家進(jìn)一步的開放，三資企業(yè)迅速發(fā)展，這對(duì)提高行業(yè)水平和擴(kuò)大出口起著重要作用。目前為止我國(guó)已和美國(guó)、德國(guó)、日本等國(guó)著名廠商合資或直接由外國(guó)廠商獨(dú)資建立了柱塞泵/馬達(dá)、行星減速機(jī)、液壓控制閥、轉(zhuǎn)向器、液壓系統(tǒng)、靜液壓傳動(dòng)裝置、液壓件的鑄造、氣動(dòng)控制閥、氣缸、氣源處理的三聯(lián)件、橡塑密封、機(jī)械密封等類產(chǎn)品生產(chǎn)企業(yè)50多家，總共引進(jìn)外資2億多美元。 (2)

7、目前狀況 1.基本概況 在經(jīng)過40多年的努力，我國(guó)的液壓、氣動(dòng)和密封件行業(yè)已形成了一個(gè)門類比較齊全，并有一定生產(chǎn)能力與技術(shù)水平的工業(yè)體系。據(jù)1995年的全國(guó)第三次工業(yè)普查統(tǒng)計(jì)，我國(guó)在液壓、氣動(dòng)和密封件工業(yè)鄉(xiāng)及鄉(xiāng)以上年銷售收入在100萬元以上的國(guó)營(yíng)、私營(yíng)、合作經(jīng)營(yíng)、村辦、個(gè)體、“三資”等企業(yè)總共有1300余家，而其中液壓約700家，氣動(dòng)和密封件各約300余家。在按1996年國(guó)際同行業(yè)的統(tǒng)計(jì)，我國(guó)液壓行業(yè)總產(chǎn)值約23.48億元，占世界第6位；氣動(dòng)行業(yè)總產(chǎn)值約4.19億元，占世界第10位。 2.當(dāng)前供需概況 在通過技術(shù)引進(jìn)，自主開發(fā)和技術(shù)改造下，高壓柱塞泵、葉片泵、齒輪泵、通用液壓閥門、油缸、無油潤(rùn)

8、滑氣動(dòng)件與各類密封件第一大批產(chǎn)品的技術(shù)水平有了顯著的提高，并可以穩(wěn)定的批量生產(chǎn)，為各類主機(jī)提高產(chǎn)品水平提供保證。另外，在液壓氣動(dòng)元件與系統(tǒng)的CAD、污染控制、比例伺服技術(shù)等方面也取得了一定成果，并已用于生產(chǎn)。目前為止，液壓、氣動(dòng)和密封件產(chǎn)品總計(jì)大概有3000個(gè)品種、23000多個(gè)規(guī)格。其中，液壓約有1200個(gè)品種、10000多個(gè)規(guī)格（其中含液力產(chǎn)品60個(gè)品種、500個(gè)規(guī)格）；氣動(dòng)約有1350個(gè)品種、8000多個(gè)規(guī)格；橡塑密封也有350個(gè)品種、5000多個(gè)規(guī)格，現(xiàn)已基本能適應(yīng)各類主機(jī)產(chǎn)品的一般需要，為重大的成套裝備的品種配套率也可達(dá)60%以上，并開始有了少量出口。 1998年國(guó)產(chǎn)的液壓件產(chǎn)量48

9、0萬件，銷售額約為28億元（其中機(jī)械系統(tǒng)占70%）；氣動(dòng)件產(chǎn)量有360萬件，銷售額約為5.5億元（其中機(jī)械系統(tǒng)約占60%）；密封件產(chǎn)量約有8億件，銷售額約為10億元（其中機(jī)械系統(tǒng)約占50%）。據(jù)中國(guó)液壓氣動(dòng)密封件工業(yè)協(xié)會(huì)在1998年年報(bào)統(tǒng)計(jì)中，液壓產(chǎn)品產(chǎn)銷率為97 .5%（液力為101%），氣動(dòng)為95.9%，密封有98.7%。這充分反映了產(chǎn)銷的基本銜接。 我國(guó)液壓、氣動(dòng)和密封工業(yè)雖然取得了很大的進(jìn)步，但與主機(jī)發(fā)展的需求，以及和世界先進(jìn)水平相比較下，還存在不少差距，主要反映在產(chǎn)品的品種、性能和可靠性等方面。如以液壓產(chǎn)品為例，產(chǎn)品的品種只有國(guó)外1/3，壽命為國(guó)外1/2。為了滿足重點(diǎn)主機(jī)、進(jìn)口主機(jī)和

10、重大技術(shù)裝備的需要，我國(guó)每年都有大量的液壓、氣動(dòng)和密封產(chǎn)品進(jìn)口。據(jù)海關(guān)統(tǒng)計(jì)及有關(guān)資料分析，在1998年液壓、氣動(dòng)和密封件產(chǎn)品的進(jìn)口額約為2億美元，其中液壓約為1.4億美元，氣動(dòng)有0.3億美元，密封約為0.3億美元，與1997年相比稍有下降。按金額計(jì)，目前進(jìn)口產(chǎn)品國(guó)內(nèi)市場(chǎng)占有率約30%。1998年國(guó)內(nèi)市場(chǎng)的液壓件需求總量約600萬件，銷售總額有40億元；氣動(dòng)件的需求總量約500萬件，銷售總額有7億多元；密封件的需求總量約11億件，銷售總額約為13億元。 (3)今后發(fā)展走勢(shì) 1.影響發(fā)展的主要因素 (1)企業(yè)產(chǎn)品的開發(fā)能力不強(qiáng)，技術(shù)開發(fā)的水平與速度不能完全滿足當(dāng)前先進(jìn)主機(jī)產(chǎn)品、重大技術(shù)裝備與進(jìn)口設(shè)

11、備的配套和維修需要； (2)不少企業(yè)制造工藝、裝備水平和管理水平都較為落后，加上質(zhì)量意識(shí)感不強(qiáng)，導(dǎo)致產(chǎn)品性能的水平低、質(zhì)量不穩(wěn)定、可靠性差，及服務(wù)不及時(shí)，缺乏使用戶能滿意和信賴的名牌產(chǎn)品； (3)行業(yè)內(nèi)的生產(chǎn)專業(yè)化程度低，力量較為分散，低水平重復(fù)嚴(yán)重，地區(qū)與企業(yè)之間產(chǎn)品趨同，導(dǎo)致盲目競(jìng)爭(zhēng)，相互壓價(jià)，從而使企業(yè)效益下降，資金缺乏、周轉(zhuǎn)困難等，產(chǎn)品開發(fā)和技術(shù)改造的投入不足，嚴(yán)重地制約了行業(yè)整體水平提高以及競(jìng)爭(zhēng)實(shí)力的增強(qiáng)； (4)當(dāng)國(guó)內(nèi)市場(chǎng)國(guó)際化程度日益提高，國(guó)外公司陸續(xù)進(jìn)入中國(guó)市場(chǎng)參與競(jìng)爭(zhēng)，再加上國(guó)內(nèi)私營(yíng)、合作經(jīng)營(yíng)、三資、個(gè)體等企業(yè)的崛起，從而給國(guó)有企業(yè)造成愈來愈大的沖擊。 2.發(fā)展走勢(shì) 隨著社會(huì)

12、主義市場(chǎng)經(jīng)濟(jì)不斷深化，液壓、氣動(dòng)與密封產(chǎn)品的市場(chǎng)供求關(guān)系發(fā)生了較大變化，長(zhǎng)期以來“短缺”為特征的賣方市場(chǎng)已基本成為了以“結(jié)構(gòu)性過剩”為特征的買方市場(chǎng)所取代。而從總體能力看，已處于供大于求的態(tài)勢(shì)，而且特別是一般低檔次的液壓、氣動(dòng)和密封件，普遍供過于求；而像主機(jī)急需的技術(shù)含量高的高參數(shù)與高附加值的高檔產(chǎn)品，又不能滿足市場(chǎng)的需要，只能依賴進(jìn)口。在我國(guó)加入WTO后，其受沖擊有可能更大。因此，在“十五”期間行業(yè)產(chǎn)值的增長(zhǎng)，決不能只依賴于量的增長(zhǎng)，而是應(yīng)針對(duì)行業(yè)自身結(jié)構(gòu)性矛盾，加大力度調(diào)整產(chǎn)業(yè)結(jié)構(gòu)和產(chǎn)品結(jié)構(gòu)，就是應(yīng)依靠質(zhì)的提高來促進(jìn)產(chǎn)品技術(shù)升級(jí)，以適應(yīng)和拉動(dòng)市場(chǎng)的需求，而求得更大的發(fā)展。2.液壓在動(dòng)力滑臺(tái)

13、上的應(yīng)用(1) 動(dòng)力滑臺(tái)介紹利用有束縛力曲線圖和狀態(tài)空間分析法來對(duì)組合機(jī)床滑臺(tái)的滑動(dòng)影響與運(yùn)動(dòng)平穩(wěn)性問題進(jìn)行分析和研究，從而建立起滑臺(tái)的液壓驅(qū)動(dòng)系統(tǒng)自調(diào)背壓調(diào)速系統(tǒng)的動(dòng)態(tài)數(shù)學(xué)模型。通過計(jì)算機(jī)數(shù)字的仿真系統(tǒng)，分析滑臺(tái)產(chǎn)生滑動(dòng)影響與運(yùn)動(dòng)不平穩(wěn)的原因和主要影響因素。從那些當(dāng)中可以得出什么樣的結(jié)論，如果能合理地設(shè)計(jì)出液壓缸與自調(diào)背壓調(diào)壓閥的結(jié)構(gòu)尺寸.文中所使用的符號(hào)如下： s1流源，即調(diào)速閥出口流量； Sel滑臺(tái)滑動(dòng)摩擦力； R滑臺(tái)等效粘性摩擦系數(shù)； I1滑臺(tái)與油缸的質(zhì)量； 12自調(diào)背壓閥閥心質(zhì)量； C1、c2油缸無桿腔及有桿腔的液容； C2自調(diào)背壓閥彈簧柔度； R1, R2自調(diào)背壓閥阻尼孔液阻； R

14、9自調(diào)背壓閥閥口液阻； Se2自調(diào)背壓閥彈簧的初始預(yù)緊力； I4, I5管路的等效液感； C5、C6管路的等效液容； R5, R7管路的等效液阻； V3, V4油缸無桿腔及有桿腔內(nèi)容積； P3, P4油缸無桿腔及有桿腔的壓力； F滑臺(tái)承受負(fù)載； V滑臺(tái)運(yùn)動(dòng)速度；文中采用的是功率鍵合圖和狀態(tài)空間分折法來建立系統(tǒng)的運(yùn)動(dòng)數(shù)學(xué)模型，而滑臺(tái)的動(dòng)態(tài)特性可以得到顯著的改善。 在組合機(jī)床正常工作中，滑臺(tái)的運(yùn)動(dòng)速度大小和它的方向及所承受負(fù)載變化都將以程度不同地影響著其工作性能。特別是工進(jìn)過程中，滑臺(tái)上負(fù)載突然消失引起的前進(jìn)及負(fù)載的周期性變化從而引起的運(yùn)動(dòng)不平穩(wěn)性，都將影響被加工件的表面質(zhì)量，在嚴(yán)重的情況下會(huì)使刀

15、具折斷。根據(jù)大連機(jī)床廠的要求，作者采用有束縛力的曲線圖與狀態(tài)空間分析法來建立組合機(jī)床滑臺(tái)的新型液壓驅(qū)動(dòng)系統(tǒng)自調(diào)背壓調(diào)速系統(tǒng)的動(dòng)態(tài)數(shù)學(xué)模型。為改善滑臺(tái)的動(dòng)態(tài)特性，有必要分析找出滑臺(tái)產(chǎn)生的前沖和運(yùn)動(dòng)不平穩(wěn)的原因及主要的影響因素，但那必須通過計(jì)算機(jī)的數(shù)字仿真和研究得出的最后結(jié)果。(2)動(dòng)態(tài)數(shù)學(xué)模型 組合機(jī)床滑臺(tái)液壓驅(qū)動(dòng)系統(tǒng)自調(diào)背壓調(diào)速系統(tǒng)的工作原理圖如圖所示。這系統(tǒng)是用來完成"工進(jìn)停止快退”的工作循環(huán)。當(dāng)滑臺(tái)在工進(jìn)時(shí)，三位四通換向閥處于圖示位置，油泵的供油壓力會(huì)在濫流閥的有效作用下近似地保持恒定，該油液流經(jīng)過換向閥與調(diào)速閥后進(jìn)入油缸的無桿腔，來推動(dòng)滑臺(tái)向前移動(dòng)。與此同時(shí)，從油缸有桿腔排出的

16、壓力油將經(jīng)自調(diào)背壓閥和換向閥流回油箱。在這個(gè)過程中，兩個(gè)單向閥和溢流閥工作狀態(tài)始終都沒有任何改變。對(duì)像組合機(jī)床滑臺(tái)的液壓驅(qū)動(dòng)系統(tǒng)自調(diào)背壓調(diào)速系統(tǒng)這種復(fù)雜非線性系統(tǒng)，為便于研究它的動(dòng)態(tài)特性，建立一個(gè)僅著重考慮主要影響因素的簡(jiǎn)單合理的動(dòng)態(tài)數(shù)學(xué)模型是尤為重要的12。從理論上分析和試驗(yàn)研究的列舉中可得知：該系統(tǒng)過程時(shí)間是遠(yuǎn)大于調(diào)速閥的過程時(shí)間，當(dāng)油缸的無桿腔有效承壓面積很大時(shí)，在調(diào)速閥出口流量瞬時(shí)的超調(diào)反映為滑臺(tái)運(yùn)動(dòng)速度變化是很小的2。為了來更加拓寬和深入研究系統(tǒng)動(dòng)態(tài)特性，使研究工作能在微型的計(jì)算機(jī)上有效地進(jìn)行，本文章將對(duì)原模型2做出進(jìn)一步簡(jiǎn)化處理，假定調(diào)速閥在系統(tǒng)整個(gè)通過過程中輸出時(shí)候恒定的流量，這

17、被看成其為流源。這樣系統(tǒng)的動(dòng)態(tài)模型結(jié)構(gòu)簡(jiǎn)圖如圖2所示，它是由油缸、滑臺(tái)、自調(diào)背壓閥和聯(lián)接管路等組成的。 功率鍵合圖是一功效流圖，是按著系統(tǒng)能量的傳遞方式，以實(shí)際結(jié)構(gòu)作為基礎(chǔ)，用集中參數(shù)把子系統(tǒng)間的作用關(guān)系抽象表示為阻性元R、感性元I和容性元C的三種作用元。采用此方法建模物理概念清晰，能結(jié)合狀態(tài)空間分析法可較準(zhǔn)確地描述和分析線性系統(tǒng)，該方法在時(shí)域中研究復(fù)雜的非線性系統(tǒng)動(dòng)態(tài)特性的一種有效方法。 據(jù)自調(diào)背壓調(diào)速系統(tǒng)各元件的主要特性及建模規(guī)則1，得出了系統(tǒng)的功率鍵合圖。圖中每根鍵上半箭頭表示功率流向，構(gòu)成了功率的兩個(gè)變量是力變量（油壓P與作用力F）和流變量（流量q與速度v）。O結(jié)點(diǎn)表示在該系統(tǒng)中屬于并

18、聯(lián)連接，各鍵上力變量相等而流變量之和為零；1結(jié)點(diǎn)表示在該系統(tǒng)中屬于串聯(lián)連接，各鍵上的流變量相等而力變量之和為零。TF表示在不同能量形式間的變換器，TF下標(biāo)的字母表示流變量或力變量的轉(zhuǎn)換比值。鍵上短橫杠表示該鍵上兩變量間因果關(guān)系。全箭頭則表示控制關(guān)系。在三種作用元中容性元與感性元的力變量和流變量之間具有積分或微分關(guān)系。因此，根據(jù)圖3可推具有九個(gè)狀態(tài)變量的復(fù)雜非線性狀態(tài)方程。文中對(duì)滑臺(tái)動(dòng)態(tài)特性研究是從滑臺(tái)的前沖與運(yùn)動(dòng)平穩(wěn)性兩方面入手的，用四階定步長(zhǎng)Runge-Kutta在IBM-PC微型計(jì)算機(jī)上來進(jìn)行數(shù)字仿真。(3)滑臺(tái)前沖 滑臺(tái)的前沖現(xiàn)象是作用在滑臺(tái)上負(fù)載突然消失（如鉆削工作情況)引起的。在此過

19、程中，滑臺(tái)負(fù)載F、運(yùn)動(dòng)速度V、油缸兩腔壓力P3與P4的變化可從圖4中仿真結(jié)果看出。當(dāng)滑臺(tái)在負(fù)載作用下作勻速運(yùn)動(dòng)時(shí)，油缸無桿腔油液壓力較高，油液中聚集大量的能量；而當(dāng)負(fù)載突然消失時(shí)，該腔的油壓隨之迅速降低，油液從高壓態(tài)轉(zhuǎn)入低壓態(tài)過程中向系統(tǒng)釋放出很多能量，從而致使滑臺(tái)高速的向前沖擊。然而滑臺(tái)前沖使油缸有桿腔油液受壓而引起背壓升高，從而耗掉系統(tǒng)中的一部分能量，對(duì)滑臺(tái)的前沖起到了一定的抑制作用。我們應(yīng)當(dāng)看出，在所研究系統(tǒng)中，自調(diào)背壓閥入口壓力要受到油缸兩腔油壓綜合性作用。在負(fù)載突然消失之時(shí)，自調(diào)背壓閥的壓力會(huì)迅速地上升，并穩(wěn)定地在高于初始背壓數(shù)值以上。從圖可見，自調(diào)背壓的調(diào)速系統(tǒng)在負(fù)載消失之時(shí)油缸背

20、壓力升高幅度大于傳統(tǒng)調(diào)速系統(tǒng)，所以其油缸的有桿腔中油液吸收的能量就多，結(jié)果滑臺(tái)的前沖量將比傳統(tǒng)調(diào)速系統(tǒng)要小約20%。由此可見采用自調(diào)背莊調(diào)速系統(tǒng)來作為驅(qū)動(dòng)系統(tǒng)滑臺(tái)在抑制前沖方面具有良好特性，其中自調(diào)背壓閥起了非常大的作用。(4)滑臺(tái)的運(yùn)動(dòng)平穩(wěn)性 當(dāng)作用在滑臺(tái)上的負(fù)載作周期變化時(shí)（比如像銑削加工的情況），滑臺(tái)運(yùn)動(dòng)速度將要產(chǎn)生一定波動(dòng)。為保證加工質(zhì)量要求，必須盡可能減小其速度波動(dòng)范圍。而從討論問題的方便性出發(fā)看，假設(shè)負(fù)載按正弦波規(guī)律變化，從而得出的數(shù)字仿真結(jié)果如圖5所示。由此看出這個(gè)系統(tǒng)與傳統(tǒng)調(diào)速系統(tǒng)有著相同變化規(guī)律以及非常接近的數(shù)值數(shù)字。其中原因是負(fù)載的變化幅度不大時(shí)，油缸兩腔的壓力也就沒有較大

21、的變化，從而最終導(dǎo)致自調(diào)背壓閥作用不夠明顯顯示。(5)改善措施通過研究的結(jié)果表明，以自調(diào)背壓調(diào)速系統(tǒng)來作為驅(qū)動(dòng)系統(tǒng)的滑臺(tái)，其動(dòng)態(tài)特性會(huì)比傳統(tǒng)的調(diào)速系統(tǒng)好。要減少滑臺(tái)前沖量，就必須在負(fù)載消失瞬間之時(shí)迅速提高油缸有桿腔的背壓力。提高滑臺(tái)的運(yùn)動(dòng)平穩(wěn)性就需增加系統(tǒng)剛性，主要措施在于減小油液體積。從系統(tǒng)結(jié)構(gòu)知道，油缸有桿腔與排油管間有一很大容積，如圖6a所示。它在存在方面的延遲和衰減了自調(diào)背壓閥作用，另一方面也降低系統(tǒng)的剛性，它會(huì)限制前沖特性與運(yùn)動(dòng)平穩(wěn)性的進(jìn)一步改善。由此，改善滑臺(tái)動(dòng)態(tài)特性可以從兩個(gè)方法進(jìn)行處理：即改變油缸容積或改變自調(diào)背壓閥結(jié)構(gòu)尺寸。通過系統(tǒng)結(jié)構(gòu)性參數(shù)的仿真計(jì)算及結(jié)果的比較可得出這樣的

22、結(jié)果：當(dāng)把油缸有桿腔與排油管間的容積V4同無桿腔與進(jìn)油管間的容積V3之比由原來5.5改為1時(shí)，如圖所示，同時(shí)把自調(diào)背壓閥的閥芯底端直徑由原來的10mm增加為13mm,阻尼三角槽邊長(zhǎng)從原來lmm減小到0.7mm時(shí)，將可使滑臺(tái)前沖量減小30%,過渡過程時(shí)間明顯的縮短，滑臺(tái)運(yùn)動(dòng)平穩(wěn)性也將會(huì)得到很大的改善。Hydraulic systemChapter 1 IntroductionHydraulic Pump Station also known as the stations are independent h- ydraulic device. It requested by the oil gr

23、adually. And controlling the hydraulic oil flow direction, pressure and flow rate, applied to the mainframe and hy- draulic devices separability of hydraulic machinery. Users will be provided after the purchase hydraulic station and host of implementing agencies (motor oil or fuel tanks) connected w

24、ith tubing, Hydraulic machinery can be realized from these movements and the work cycle.Hydraulic pump station is installed, Manifold or valve combination, t- anks, a combination of electrical boxes.Functional components : Pump device - is equipped with motors and pumps, hydraulic station is the sou

25、rce of power. to mechanical energy into hydraulic oil pressure can be. Manifold - from hydraulic valve body and channel assembled. Right direction for implementation of hydraulic oil, pressure and flow control. Valve portfolio - plate valve is installed in up board after board conn-ects with the sam

26、e functional IC. Tank - plate welding semi-closed containers, also loaded with oil filtering network, air filters, used oil, oil filters and cooling. Electrical boxes - at the two patterns. A set of external fuse terminal plate; distribution of a full range of electrical control. Hydraulic Station p

27、rinciple : motor driven pump rotation, which pump oil absorption from the oil tank. to mechanical energy into hydraulic pressure to the station, hydraulic oil through Manifold (or valve combinations) realized the direction, pressure, After adjusting flow pipe and external to the cylinder hydraulic m

28、achinery or motor oil, so as to control the direction of the motive fluid transformation force the size and speed the pace of promoting the various acting hydraulic machinery. 1.1 A development course China Hydraulic (including hydraulic, the same below), pneumatic and seals industrial development p

29、rocess can be broadly divided into three phases, namely : 20 early 1950s to the early 1960s, the initial stage; 60's and 70 for specialized production system ;8090's growth stage for the rapid development stage. Which, hydraulic industry in the early 1950s from the machine tool industry prod

30、uction of fake Su-grinder, broaching machine, copying lathe, and other hydraulic drive started, Hydraulic Components from the plant hydraulic machine shop, self-occupied. After entering the 1960s, the application of hydraulic technology from the machine gradually extended to the agricultural machine

31、ry and mechanical engineering fields, attached to the original velocity of hydraulic shop some stand out as pieces of hydraulic professional production. To the late 1960s, early 1970s, with the development of mechanized production, especially in the second automobile factory in providing efficient,

32、automated equipment, along with the Hydraulic Components manufacturing has experienced rapid development of the situation, a group of SMEs have become professional hydraulic parts factory. 1968 China's annual output of hydraulic components have nearly 200,000 in 1973, machine tools, agricultural

33、 machinery, mechanical engineering industries, the production of hydraulic parts factory has been the professional development of more than 100 and an annual output more than one million. an independent hydraulic manufacturing industry has begun to take shape. Then, hydraulic pieces of fake products

34、 from the Soviet Union for the introduction of the product development and technical design combining the products to the pressure, Hypertension, and the development of the electro-hydraulic servo valves and systems, hydraulic application areas further expanded. Aerodynamic than the start of the ind

35、ustrial hydraulic years later, in 1967 began to establish professional pneumatic components factory, Pneumatic Components only as commodity production and sales. Sealed with rubber and plastics, mechanical seals and sealing flexible graphite sealing industry, the early 1950s from the production ordi

36、nary O-rings. rubber and plastics extrusion, such as oil seal sealing and seal asbestos products start to the early 1960s, begun production of mechanical seals and flexible graphite sealing products. 1970s, the burning of the former Ministry, a Ministry, the Ministry of Agricultural Mechanization Sy

37、stem, a group of professional production plants have been established, and the official establishment of industries to seal industrial development has laid the foundation for growth.Since the 1980s, in the country's reform and opening up policy guidelines, with the development of the machinery i

38、ndustry, based mainframe pieces behind the conflicts have become increasingly prominent and attracted the attention of the relevant departments. To this end, the Ministry of the original one in 1982, formed the basis of common pieces of Industry, will be scattered in the original machine tools, agri

39、cultural machinery, mechanical engineering industries centralized hydraulic, pneumatic and seals specialized factories, placing them under common management infrastructure pieces Bureau, so that the industry in the planning, investment, technology and scientific research and development in areas suc

40、h as infrastructure pieces Bureau of guidance and support. Since then entered a phase of rapid development, has introduced more than 60 items of advanced technology from abroad, including more than 40 items of hydraulic, pneumatic 7. After digestion and absorption and transformation, now have mass p

41、roduction, and industry-leading products. In recent years, the industry increased the technological transformation efforts, in 1991, Local enterprises and the self-financing total input of about 20 billion yuan, of which more than 1.6 billion yuan Hydraulic. Through technological transformation and

42、technology research, and a number of major enterprises to further improve the level of technology, technique and equipment to be greatly improved. In order to form a higher starting point, specialization, and run production has laid a good foundation. In recent years, many countries in the developme

43、nt of common ownership guidelines, under different ownership SMEs rapid rise showing great vitality. With the further opening up, three-funded enterprises rapid development of industry standards for improving and expanding exports play an important role. Today, China has and the United States, Japan

44、, Germany and other countries famous manufacturers joint ventures or wholly-owned by foreign manufacturers to establish a piston pump / motor, planetary reduction gears, steering gear, hydraulic control valve, hydraulic system, hydrostatic transmission, hydraulic Casting. pneumatic control valve, cy

45、linder, gas processing triple pieces, mechanical seals, rubber and seal products more than 50 production enterprises, attracting foreign investment over 200 million U.S. dollars. 1.2 the current situation 1.21Basic Profiles After 40 years of efforts, China hydraulic, pneumatic and sealing industry h

46、as formed a relatively complete categories. a certain level of technical capacity and the industrial system. According to the 1995 Third National Industrial Census statistics, hydraulic, Pneumatic seals and industrial 370,000 annual sales income of 100 million yuan in state-owned, village-run, priva

47、te and cooperative enterprises, individual, "three capital" enterprises with a total of more than 1,300, of which about 700 hydraulic, Pneumatic seals and the approximately 300 thousand. By 1996 with the international trade statistics, the total output value of China's industry hydraul

48、ic 2.348 billion yuan, accounting for the world's 6; Pneumatic industry output 419 million yuan, accounting for world No. 10. 1.22 the current supply and demand profiles Through the introduction of technology, independent development and technological innovation, and high-pressure piston pump, g

49、ear pumps, vane pump, General Motors hydraulic valves, tanks, Non-lubricated aerodynamic pieces and various seals of the first large technology products has increased noticeably. stability of the mass production may, for various mainframe products provide a level of assurance. In addition, hydraulic

50、 and pneumatic components of the CAD system, pollution control, proportional servo technology has scored some achievements, and is already in production. Currently, hydraulic, pneumatic and seals products total about 3,000 species, more than 23,000 specifications. Among them, there are 1,200 hydraul

51、ic varieties, more than 10,000 specifications (including hydraulic products 60 varieties 500 specifications); Pneumatic are 1,350 varieties, more than 8,000 specifications; Rubber seal 350 species more than 5,000 specifications have been basically cater to the different types of mainframe products t

52、o the general needs, complete sets of equipment for major varieties of matching rate was over 60%, and started a small amount of exports. 1998 pieces of homemade hydraulic output 4.8 million. sales of about 28 billion (of which about 70% mechanical systems); aerodynamic pieces yield 3.6 million. sal

53、es of about 5.5 billion (of which about 60% of mechanical systems); Seals output of about 800 million. sales of about 10 billion (of which about 50% mechanical systems). According to the China Hydraulic Pneumatic Seals Industry Association 1998 annual report, hydraulic product sales rate of 97. 5% (

54、101% for hydraulic), pneumatic 95.9%, 98.7% sealed. This fully reflects the basic marketing convergence.My hydraulic, pneumatic and sealing industry has attained a great deal of progress, but with mainframe development needs, and the world's advanced level, there are still many gaps, mainly refl

55、ected in the product variety, performance and reliability, and so on. Hydraulic products as an example, products abroad only one-third, life for half abroad. In order to meet key mainframe, and mainframe imports of major technology and equipment needs, every year a large number of hydraulic, pneumat

56、ic and sealing products imports. According to customs statistics and the analysis of data, in 1998 hydraulic, pneumatic and seals in the import about 200 million U.S. dollars, Hydraulic which about 1.4 billion dollars, aerodynamic nearly 030 million U.S. dollars, sealed about 030 million U.S. dollar

57、s. compared with a slight decline in 1997. By sums, currently imported products on the domestic market share of about 30%. 1998 pieces of the domestic market demand for hydraulic total of about six million, the total sales of nearly 40 billion; aerodynamic pieces of the total demand of about 5 milli

58、on, with sales more than 700 million yuan; Seals total demand of about 1.1 billion. total sales of about 1.3 billion. 1.3 the development trend of the future 1.31 affect the development of the main factors (1) product development ability, and the level of technological development and speed can not completely meet the advanced mainframe products, major equipment and technology imported equipment and maintenance support; (2) the number of enterprises manufacturing technology, the level of equipment and management standards are comparatively backward,