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存檔編碼：無無錫錫太太湖湖學(xué)學(xué)院院 2013 屆屆畢畢業(yè)業(yè)作作業(yè)業(yè)周周次次進(jìn)進(jìn)度度計(jì)計(jì)劃劃、檢檢查查落落實(shí)實(shí)表表 系別：信機(jī)系 班級：機(jī)械（92）學(xué)生姓名：武文琦 課題（設(shè)計(jì)）名稱：4S店汽車維修專用升降機(jī)設(shè)計(jì) 開始日期：2012年11月12日周次起止日期工作計(jì)劃、進(jìn)度每周主要完成內(nèi)容存在問題、改進(jìn)方法指導(dǎo)教師意見并簽字備 注1-32012年11月12日-2012年12月2日教師下達(dá)畢業(yè)設(shè)計(jì)任務(wù)，學(xué)生初步閱讀資料，完成畢業(yè)設(shè)計(jì)開題報(bào)告按照任務(wù)書要求查閱論文相關(guān)參考資料，填寫畢業(yè)設(shè)計(jì)開題報(bào)告書存在問題：對課題所涉及的內(nèi)容不怎么了解，對設(shè)計(jì)目的及要求不明確。改進(jìn)方法：向指導(dǎo)老師請教，通過導(dǎo)師指導(dǎo)后，查閱相關(guān)資料，重新填寫報(bào)告。4-102012年12月3日-2013年1月20日指導(dǎo)專業(yè)實(shí)訓(xùn)綜合實(shí)訓(xùn)，理解升降機(jī)工作原理存在問題：只能在校內(nèi)查閱升降機(jī)的相關(guān)資料，并沒有實(shí)際了解。改進(jìn)方法：到廠里實(shí)地考察，積累經(jīng)驗(yàn)。11-122013年1月21日-3月1日指導(dǎo)畢業(yè)實(shí)習(xí)到無錫某廠實(shí)習(xí)，學(xué)習(xí)升降機(jī)工作原理存在問題：在實(shí)習(xí)過程中，雖然初步理解升降機(jī)工作原理，但是一些因素的影響容易被我忽視。改進(jìn)方法：向廠里經(jīng)驗(yàn)豐富的老師傅學(xué)習(xí)，分析各種因素對升降機(jī)工作的影響。132013年3月4日-3月8日收集資料對升降機(jī)的各個(gè)部件進(jìn)行分析存在問題：由于實(shí)習(xí)的原因，我沒有過多的時(shí)間去查閱升降機(jī)的設(shè)計(jì)原則及注意事項(xiàng)。改進(jìn)方法：利用晚上有限的時(shí)間上網(wǎng)查資料，看視頻。142013年3月11日-3月15日初步確定正文部分的目錄確定升降機(jī)工作過程分為幾大部分存在問題：液壓系統(tǒng)的設(shè)計(jì)存在一定問題。改進(jìn)方法：上網(wǎng)查找液壓系統(tǒng)的相關(guān)資料，明確液壓系統(tǒng)的重要性。152013年3月18日-3月22日正文部分的具體設(shè)計(jì)確定正文部分的框架存在問題：對一些重要章節(jié)沒有作重點(diǎn)介紹。改進(jìn)方法：向同學(xué)和導(dǎo)師請教，確定重點(diǎn)章節(jié)。162013年3月25日-3月29日填寫中英文摘要根據(jù)正文部分的重點(diǎn)以及相關(guān)資料，完成中英文摘要。存在問題：英文翻譯某些語句不通順，還有部分中文不會(huì)翻譯。改進(jìn)方法：向校英語老師和導(dǎo)師請教，使英文和中文一致。172013年4月1日-4月5日升降機(jī)的繪制完成升降機(jī)裝配圖存在問題：在繪制裝配圖過程中，發(fā)現(xiàn)某些數(shù)據(jù)明顯錯(cuò)誤。改進(jìn)方法：對于某些數(shù)據(jù)的錯(cuò)誤，重新修改正文部分，使各數(shù)據(jù)合理。182013年4月8日-5月12日升降機(jī)的繪制從升降機(jī)裝配圖中拆分，完成各零件圖存在問題：零件圖粗實(shí)線不分，缺少相關(guān)數(shù)據(jù)的標(biāo)注。改進(jìn)方法：重新標(biāo)注，使零件圖達(dá)到標(biāo)準(zhǔn)要求。192013年4月15日-4月19日修改正文部分根據(jù)導(dǎo)師指導(dǎo)，修改正文存在問題：正文部分有些章節(jié)未充分考慮各種因素的影響。改進(jìn)方法：在導(dǎo)師的細(xì)心指導(dǎo)下，修改正文。202013年4月22日-4月26日修改升降機(jī)裝配圖和零件圖依據(jù)修改的正文內(nèi)容，重新修改裝配圖和零件圖存在問題：圖紙尺寸和正文部分的計(jì)算尺寸有些不符。改進(jìn)方法：嚴(yán)格按照正文數(shù)據(jù)的要求，修改圖紙。212013年4月29日-5月3日完成致謝、參考目錄整理論文，填寫致謝和參考文獻(xiàn)存在問題：對于參考文獻(xiàn)沒有嚴(yán)格按照學(xué)校的標(biāo)準(zhǔn)。改進(jìn)方法：按照學(xué)校模板，重新修改參考文獻(xiàn)。222013年5月6日-5月10日總計(jì)畢業(yè)論文對升降機(jī)工作過程進(jìn)行系統(tǒng)的總結(jié)存在問題：總結(jié)過程中依然會(huì)發(fā)現(xiàn)某些錯(cuò)誤。改進(jìn)方法：針對某些錯(cuò)誤，認(rèn)真修改。232013年5月13日-5月17日導(dǎo)師檢查根據(jù)導(dǎo)師的意見修改論文存在問題：對于參考文獻(xiàn)沒有嚴(yán)格按照學(xué)校的標(biāo)準(zhǔn)。改進(jìn)方法：按照學(xué)校模板，重新修改參考文獻(xiàn)。242013年5月20日-5月25日完成論文最后的相關(guān)工作論文打印、裝訂、上交存在問題：打印時(shí)發(fā)現(xiàn)有些內(nèi)容不符合學(xué)校要求。改進(jìn)方法：按照學(xué)校要求重新打印。說明：1、“工作計(jì)劃、進(jìn)度”、“指導(dǎo)教師意見并簽字”由指導(dǎo)教師填寫，“每周主要完成內(nèi)容”，“存在問題、改進(jìn)方法”由學(xué)生填寫。2、本表由各系妥善歸檔，保存?zhèn)洳?。周次起止日期工作?jì)劃、進(jìn)度每周主要完成內(nèi)容存在問題、改進(jìn)方法指導(dǎo)教師意見并簽字備 注編號
無錫太湖學(xué)院
畢業(yè)設(shè)計(jì)（論文）
相關(guān)資料
題目： 4S店汽車維修專用升降機(jī)設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動(dòng)化專業(yè)
學(xué) 號： 0923092
學(xué)生姓名： 武文琦
指導(dǎo)教師： 范圣耀 （職稱：副教授 ）
（職稱： ）
2013年5月20日
目 錄
一、畢業(yè)設(shè)計(jì)（論文）開題報(bào)告
二、畢業(yè)設(shè)計(jì)（論文）外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文（論文）計(jì)劃、進(jìn)度、檢查及落實(shí)表”
四、實(shí)習(xí)鑒定表
無錫太湖學(xué)院
畢業(yè)設(shè)計(jì)（論文）
開題報(bào)告
題目： 4S店汽車維修專用升降機(jī)設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動(dòng)化 專業(yè)
學(xué) 號： 0923092
學(xué)生姓名： 武文琦
指導(dǎo)教師： 范圣耀 （職稱：副教授 ）
（職稱： ）
2012年11月25日
課題來源
經(jīng)老師的介紹在工廠實(shí)習(xí)，經(jīng)過幾個(gè)月的親身實(shí)踐，我對汽車維修專用升降機(jī)有了一個(gè)系統(tǒng)的了解，因此選擇了自己熟悉的產(chǎn)作為畢業(yè)論文的課題。
科學(xué)依據(jù)（包括課題的科學(xué)意義；國內(nèi)外研究概況、水平和發(fā)展趨勢；應(yīng)用前景等）
（1）課題科學(xué)意義
隨著汽車使用量的迅速增加，社會(huì)對汽車維修工具和設(shè)備的工作效率也越來越高。由此原因，設(shè)計(jì)一種維修設(shè)備，它可根據(jù)汽車維修部位的不同而隨時(shí)調(diào)整汽車的位置，方便維修，減輕維修人員的勞動(dòng)負(fù)荷從而提高工作效率，就成為必然需要。具有結(jié)構(gòu)緊湊，占地面積小，安裝和拆卸操作方便，故障率低，常見故障易處理，維護(hù)方便等優(yōu)點(diǎn)的汽車升降機(jī)，就可以滿足汽車維修對提高工作效率的要求。本次畢業(yè)設(shè)計(jì)的題目來源于生產(chǎn)第一線，所設(shè)計(jì)的產(chǎn)品具有實(shí)用價(jià)值，已經(jīng)有成熟產(chǎn)品生產(chǎn)。我們可以參考現(xiàn)有產(chǎn)品做出的改進(jìn)設(shè)計(jì)，使產(chǎn)品機(jī)構(gòu)更合理、更實(shí)用、更可靠。
（2）汽車升降機(jī)的研究狀況及其發(fā)展前景
我國每年升降平臺(tái)市場成交額高達(dá)500億元左右，但其中卻有100多億元的市場被國外升降平臺(tái)企業(yè)占領(lǐng)。要改變這種現(xiàn)狀，提高升降平臺(tái)質(zhì)量是關(guān)鍵。升降平臺(tái)在機(jī)械產(chǎn)品中占有相當(dāng)大的比重。據(jù)國外工業(yè)發(fā)達(dá)國家統(tǒng)計(jì)，升降平臺(tái)的產(chǎn)值是壓縮機(jī)、風(fēng)機(jī)和泵三者的總和，約占整個(gè)機(jī)械工業(yè)產(chǎn)值的5%。同時(shí)，作為重大技術(shù)裝備的重要組成部分，尤其是在電力、石化、冶金、城市供排水系統(tǒng)中，升降平臺(tái)更是起著關(guān)鍵作用，而且用量非常大。目前，我國升降平臺(tái)企業(yè)約6000余家，其中年產(chǎn)值超過500萬元的有900家。國內(nèi)上市的升降平臺(tái)公司3家，即中核科技、洪城股份、廣東明珠。去年，中核科技主營業(yè)務(wù)收入2.35億元，洪城股份主營業(yè)務(wù)收入1.46億元，廣東明珠主營業(yè)務(wù)收入1.5億元。這些企業(yè)，無論是其規(guī)模，還是產(chǎn)品質(zhì)量，目前都無法與國外同類企業(yè)抗衡。
目前，國內(nèi)外升降平臺(tái)的發(fā)展趨勢主要有以下五個(gè)方面：
?（1）升降平臺(tái)的全球化趨勢?
（2）以跨國公司為主導(dǎo)，產(chǎn)業(yè)鏈細(xì)分的趨勢
（3）以科技中心控制升降平臺(tái)中心的新趨勢
（4）升降平臺(tái)的信息化、虛擬化趨勢
（5）升降平臺(tái)的綠色化趨勢向環(huán)?；蚓G色化方向發(fā)展
研究內(nèi)容
氣液動(dòng)剪叉式升降平臺(tái)具有制造容易、價(jià)格低廉、堅(jiān)實(shí)耐用、便于維修保養(yǎng)等特點(diǎn)。在民航、交通運(yùn)輸、冶金、汽車制造等行業(yè)逐漸得到廣泛應(yīng)用。通過對汽車專用升降平臺(tái)的技術(shù)參數(shù)，結(jié)合具體實(shí)例，對機(jī)構(gòu)中兩種液壓缸布置方式分析比較，并根據(jù)要求對液壓傳動(dòng)系統(tǒng)個(gè)部分進(jìn)行設(shè)計(jì)計(jì)算最終確定液壓執(zhí)行元件--液壓缸，通過對叉桿的各項(xiàng)受力分析確定臺(tái)板與叉桿的載荷要求，最終完成汽車專用升降平機(jī)的設(shè)計(jì)要求。
擬采取的研究方法、技術(shù)路線、實(shí)驗(yàn)方案及可行性分析
研究的內(nèi)容?
（1）舉升機(jī)臺(tái)板降到下位時(shí)，與地面應(yīng)盡可能在同一平面上。為此，在保證強(qiáng)度和剛度的前提下，應(yīng)盡可能降低舉升機(jī)臺(tái)板和橫梁的高度。在條件許可時(shí)，舉升機(jī)臺(tái)板（或橫梁）應(yīng)選擇專用型鋼或用鋼板拆彎成形。?
（2）正確選擇傳動(dòng)方式。采用機(jī)械傳動(dòng)（螺母、螺桿）或液壓傳動(dòng)（油缸），均?用電動(dòng)機(jī)驅(qū)動(dòng)。機(jī)械傳動(dòng)的成本較高，耗能較多，但安全性較好。?
（3）絲繩的選擇。為了減少滑輪直徑從而縮小寄生機(jī)立柱的斷面尺寸，應(yīng)該選用高柔度的鋼絲繩。鋼絲繩應(yīng)有較高的安全系數(shù)，一般應(yīng)達(dá)8。為此，應(yīng)增加鋼絲繩鋼絲的數(shù)目。這樣，不僅價(jià)格便宜，還能減輕鋼絲繩的磨損，延長其使用壽命。
研究計(jì)劃及預(yù)期成果
研究計(jì)劃：
2012年11月12日-2012年12月2日：按照任務(wù)書要求查閱論文相關(guān)參考資料，填寫畢業(yè)設(shè)計(jì)開題報(bào)告書。
2012年12月3日-2013年3月1日：填寫畢業(yè)實(shí)習(xí)報(bào)告。
2013年3月4日-2013年3月14日：按照要求修改畢業(yè)設(shè)計(jì)開題報(bào)告。
2013年3月15日-2013年3月21日：學(xué)習(xí)并翻譯一篇與畢業(yè)設(shè)計(jì)相關(guān)的英文材料。
2013年3月22日-2013年4月11日：4S店汽車維修專用升降機(jī)正文設(shè)計(jì)。
2013年4月12日-2013年4月25日：繪制裝配圖和零件圖。
2013年4月26日-2013年5月20日：畢業(yè)論文撰寫和修改工作。
預(yù)期成果：
通過不同方案的比較，以及考慮不同因素的影響，最后確定合理的升降機(jī)設(shè)計(jì)方案，該方案能最大限度的滿足使用要求。
特色或創(chuàng)新之處
（1）對本廠的幾種升降機(jī)結(jié)構(gòu)對比，分析優(yōu)劣。
（2）充分考慮使用環(huán)境及使用成本。
（3）采用固定某些參量、改變某些參量來研究問題的方法，思路清晰，簡潔明了，行之有效。
已具備的條件和尚需解決的問題
（1）實(shí)驗(yàn)方案思路已經(jīng)非常明確，已經(jīng)具備使用CAD制圖的能力和圖像處理方面的知識(shí)。
（2）理論設(shè)計(jì)的能力尚需加強(qiáng)。
（3）學(xué)校收藏了相關(guān)資料，網(wǎng)絡(luò)工具靈活運(yùn)用。
指導(dǎo)教師意見
指導(dǎo)教師簽名：
年 月 日
教研室（學(xué)科組、研究所）意見
教研室主任簽名：
年 月 日
系意見
主管領(lǐng)導(dǎo)簽名：
年 月 日
Hydraulic system
Chapter 1 Introduction
Hydraulic Pump Station also known as the stations are independent h- ydraulic device.
It requested by the oil gradually. 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 with 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 source 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 same 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 principle : 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 machinery 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 process 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 ;80~90's growth stage for the rapid development stage. Which, hydraulic industry in the early 1950s from the machine tool industry production 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 machinery 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, 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 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 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 industrial 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 ordinary 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 System, 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 industry, 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, agricultural 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 such 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 production, 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 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 development 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, 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, cylinder, 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 has 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, private 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 hydraulic 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, gear 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 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 hydraulic 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 to 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. sales 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% (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 reflected 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, pneumatic 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. dollars. 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 million, 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, coupled with a strong sense of quality, resulting in low levels of product performance, quality, Reliability poor services in a timely manner, lack of user satisfaction and trust of the brand-name products;
(3) industry specialization of production low, scattered strength, low repeat serious, between regions and enterprises of convergence products, blindly compete with each other, driving down prices, the decline of enterprise returns, lack of funds, liquidity difficulties, product development and technological transformation is inadequate and seriously restricted the industry to improve the overall level of competition and the increase of strength;
(4) The internationalization of the domestic market and the increasing degree of foreign companies have entered the Chinese market and participate in competition with the domestic private and cooperative enterprises, individuals, foreign-funded enterprises, such as the rise of state-owned enterprises due to the growing impact.
1.32 the development trend
As the socialist market economy continues to deepen, hydraulic, pneumatic and sealing products in the market supply and demand and there is a greater change, long ago to a "shortage" of the seller's market has basically become a "structural surplus" of the characteristics of the buyer's market place . Overall capacity, is already in oversupply situation, in particular the general low level of hydraulic, pneumatic and seals, the general oversupply; and the host of urgent high-tech high-parameter, high value-added high-end products, and they do not satisfy the market needs, only dependent on imports. China joins the WTO, its impact may be even greater. Therefore, the "15" during the growth of the output value of industry, must not depend on volume growth and the industry should address the structural problems of their own, increase the intensity of the adjustment of the industrial structure and product mix, is, we should rely on the improvement of quality, and promote technical upgrading of products to meet market demand and stimulating, seek greater development.
2 The application of hydraulic power sliding stage
2.1 Power sliding Taiwan introduced
This paper deals with the investigation for slide unit's impact and motion stabil?ity in modular machine tool fay means of the method of power bond graph and state space analysis. The dynamic mathematical model of self-adjusting back pressure speed control system used to drive slide unit is established. Main reasons and affect?ing factors for slide unit impact and motion unstability are analysed through compu?ter digital simulation, It is concluded from those that, if the structural dimensions of hydraulic cylinder and back pressure valve are designed rationally, the slide unit's dynamics will markedly be improved.
NOMENCLATURE
Sf flow source
Sei sliding friction force in slide unit
R equivalent viscous friction coefficient in slide unit
Ii mass of slide unit and cylinder
h mass of SABP valve spool
Ci,C2 hydraulic capacitances of rod chamber and non-rod chamber in cylinder re-
spec-tively
C3 spring compliance of SABP valve
R]rR2 hydraulic resistances of damping holes
R9 hydraulic resistance of orifice of SABP valve
Se2 presetting force of spring in SABP valve
I4J5 equivalent liquid inertia in pipe lines
C^Cg equivalent hydraulic capacitances in pipe lines
equivalent hydraulic resistances in pipe lines
V-j V^ oil-containing volumes in non-rod chamber and rod chamber respectively
P,r:, P-i oil pressures in non-rod chamber and rod chamber respectively
F load acted on slide unit
V slide unit velocity
* Department of Mechanical Engineering, Dalian Ur.iversity of Technology, Dalian. China.
2.2 Introduction
During operation of modular machine tool, the changes of slid unit's speed and load acted on it in both magnitude and direction will affect working performar.ee to a different extent Particularly the impact caused by sudden vanishing of load and the motion unstability due to periodical change of load in operation will affect the surface quality of the workpiece machined, and the tool would be broken off under serious conditions, By using the method of power bond graph and state space analy sis, the dynamic mathematical model of the system used to drive slide unit is estab lished, that is called as self-adjusting back pressure speed control system and abbre viated to SABP system. In order to improve slide unit's dynamics, it is necessary to find out the main reasons and affecting factors, that must be based on computer digital simulation and study on the results.
2.3 Dynamic Mathematica Modeld
The schematic diagram of SABP system is shown in Fig.l, the system is used to perform the cycle of feeding, stopping and returning. Four way control valve works in the right position during slide unit's feeding. The supply pressure of the pump is approximately constant under the action of pressure relief valve, the oil through the control valve and pressure compensated flow control valve enters the non-rod chamber to put slide unit forward. At the same time, the oil from the rod chamber is discharged through SABP valve and directional control valve to tank. In this process, the state of two check valves and pressure relief valve is not changed, To establish the mathematical model as reasonably and simply as possible, consid eration must be focused on main affecting factors for a complex non-linear system such as the SABP system. It is illustrated by theoretical analysis and test result ' , that the transient time of the system is much longer than that of the flow control valve, and the flowrate overshoot of the valve in transients affects very small to slide unit speed because of the ;lar