【正文】 技術(shù)引進(jìn)鋼鐵行業(yè)，1977年日木新日鐵公司己對(duì)初軋機(jī)牌坊、力一向接軸等重要部件的故障進(jìn)行檢測(cè)診斷。美國(guó)鋼鐵公司Lorain工廠1170mm初軋機(jī)山于1年內(nèi)折斷了3根力一向接軸，因而在該軋機(jī)上研制裝配了扭知監(jiān)測(cè)儀，非接觸地連續(xù)測(cè)量軋機(jī)的扭振，預(yù)報(bào)危險(xiǎn)，以保護(hù)主傳動(dòng)設(shè)備。瑞典Fundia公司為了消除軋機(jī)傳動(dòng)裝置的機(jī)械共振現(xiàn)象，安裝了驅(qū)動(dòng)軟件控制器(RTE)當(dāng)軋機(jī)受到鋼坯沖擊出現(xiàn)減速時(shí)，RTE可使馭動(dòng)裝置平穩(wěn)增速，并使合成沖擊速度下降，提高馭動(dòng)裝置速度，使其達(dá)到改造前的2倍。寶鋼2050mm熱軋生產(chǎn)線(xiàn)精軋機(jī)組也安裝了在線(xiàn)監(jiān)測(cè)與故障診斷系統(tǒng)，并通過(guò)Internet實(shí)現(xiàn)了網(wǎng)絡(luò)監(jiān)測(cè)診斷功能,F2軋機(jī)上共設(shè)置160多個(gè)檢測(cè)點(diǎn)，按所監(jiān)測(cè)物理量的不同分布在測(cè)力、液壓、振動(dòng)、溫度和電氣系統(tǒng)上。工程師站服務(wù)器對(duì)數(shù)據(jù)庫(kù)服務(wù)器的數(shù)據(jù)庫(kù)進(jìn)行備份，診斷分析、采樣數(shù)據(jù)和訪問(wèn)服務(wù)也山工程師服務(wù)器負(fù)貢。系統(tǒng)的后續(xù)功能通過(guò)光纜將現(xiàn)場(chǎng)診斷網(wǎng)和辦公網(wǎng)相連，最終提供遠(yuǎn)程診斷服務(wù)。首先，振動(dòng)問(wèn)題是此類(lèi)機(jī)械運(yùn)行中最主要的問(wèn)題。大型回轉(zhuǎn)機(jī)械的故障診斷基木手段有: （1)FFT分析。近年來(lái)，信號(hào)處理技術(shù)的發(fā)展為故障診斷的分析手段提供了更多選擇，如:①時(shí)域分析，包括波形分析、相關(guān)分析、時(shí)域?yàn)V波、時(shí)域平均、包絡(luò)分析、小波分解、時(shí)間系列建模、軸心軌跡分析等；②頻域分析，包括FFT幅值譜、相位譜、AR譜、全息譜分析等；③時(shí)頻域分析，包括Wigner分布、短時(shí)FFT譜等。隨著計(jì)算機(jī)技術(shù)和信號(hào)處理技術(shù)的飛速發(fā)展，故障診斷技術(shù)的現(xiàn)場(chǎng)實(shí)施更多地依賴(lài)于計(jì)算機(jī)，從設(shè)備狀態(tài)信息采集、信號(hào)分析、數(shù)據(jù)庫(kù)管理，甚至包括診斷結(jié)論的獲得均由計(jì)算機(jī)完成。分析方法基本涵蓋了上述提及的各種手段。20世紀(jì)90年代以來(lái)，大型機(jī)組監(jiān)測(cè)診斷系統(tǒng)的一個(gè)重要發(fā)展方向是網(wǎng)絡(luò)化。在故障診斷理論研究方而，小波分析己成熱點(diǎn)。近幾年來(lái)，模糊控制、故障樹(shù)分析、專(zhuān)家系統(tǒng)、人工神經(jīng)網(wǎng)絡(luò)等新技術(shù)不斷出現(xiàn)，為故障診斷技術(shù)在理論方而的發(fā)展帶來(lái)了新意。在監(jiān)測(cè)診斷系統(tǒng)的軟硬件配備方而，軟儀表技術(shù)成了最新的研究熱點(diǎn)。目前國(guó)內(nèi)很多高校，如西安交通大學(xué)、華中科技大學(xué)、北京工業(yè)大學(xué)、北京科技大學(xué)都己把美國(guó)NI公司研制的LabVIEW軟件平臺(tái)作為監(jiān)測(cè)診斷系統(tǒng)的開(kāi)發(fā)工具，并用于生產(chǎn)實(shí)際。尤其是機(jī)床、一般旋轉(zhuǎn)機(jī)械、電機(jī)設(shè)備等，不僅在美國(guó)、日本等發(fā)達(dá)國(guó)家出現(xiàn)了許多監(jiān)測(cè)診斷的公司在我國(guó)也有很多科研人員致力于此項(xiàng)研究。通過(guò)對(duì)寶鋼熱軋廠精軋F(tuán)2機(jī)架的結(jié)構(gòu)、歷史故障記錄及軋制生產(chǎn)過(guò)程等一系列因素進(jìn)行綜合分析，在軋機(jī)故障診斷系統(tǒng)中設(shè)置了169路通道，包括測(cè)力系統(tǒng)5路、液壓系統(tǒng)103路、振動(dòng)系統(tǒng)29路、溫度系統(tǒng)8路、電氣量8路等。此外，形成診斷知識(shí)庫(kù)系統(tǒng)也是大勢(shì)所趨。通過(guò)這次設(shè)計(jì)，鍛煉了我獨(dú)立完成設(shè)計(jì)任務(wù)的能力，同時(shí)加深了對(duì)專(zhuān)業(yè)課的理解，為畢業(yè)參加工作做了很好的鋪墊。由于采用兩臺(tái)電機(jī)通過(guò)萬(wàn)向接軸直接帶動(dòng)工作輥工作，更易于實(shí)現(xiàn)可逆運(yùn)轉(zhuǎn)。提高了傳動(dòng)質(zhì)量；電機(jī)采用直流變頻調(diào)速，具有良好的調(diào)速性能，其調(diào)速范圍寬，平滑性好，響應(yīng)速度快，效率高大大提高軋制質(zhì)量，加快反向速度。將我們的所學(xué)用到了實(shí)際問(wèn)題上。我非常感謝我的指導(dǎo)教師徐澤寧教授，每當(dāng)我到困難時(shí)，徐老師都能在百忙中抽出時(shí)間為我悉心講解。正是有了大家的幫助我才能利完成畢業(yè)設(shè)計(jì)，謹(jǐn)此致以最誠(chéng)摯的謝意。這些金屬很難用常規(guī)方法加工，用常規(guī)的切削刀具不可能加工極其復(fù)雜的形狀，電火花加工使之變得相對(duì)簡(jiǎn)單了。塑料工業(yè)已廣泛使用這種方法，如在鋼制模具上加工幾乎是任何形狀的模腔。切削刀具用導(dǎo)電材料（通常是碳）制造。工件與電極都浸在不導(dǎo)電的液體里，這種液體通常是輕潤(rùn)滑油。 ~（~）的間隙，以阻止他們相互接觸。在火花沖擊的局部區(qū)域，產(chǎn)生了大量的熱量，金屬融化了，從工件表面噴出融化金屬的小粒子。 在最近幾年，電火花加工的主要進(jìn)步是降低了它加工后的表面粗糙度。用高的金屬切除率[如高達(dá)15in3/h()]時(shí)，表面粗糙度為1000vin.(25vm)?？焖偾谐饘伲ù智邢鳎r(shí)，用大電流,低頻率,高電容和最小的間隙電壓。 與常規(guī)機(jī)加工方法相比，電火花加工有許多優(yōu)點(diǎn)。對(duì)用常規(guī)方法極難切削的硬質(zhì)合金和超韌性的太空合金，電火化加工特別有價(jià)值。 3 . 很容易將斷在工件中的絲錐和鉆頭除。 5 . 加工出的零件無(wú)毛刺。 7 . 對(duì)許多類(lèi)型的工件，一般不需第二次精加工。 9 .一個(gè)人可同時(shí)操作幾臺(tái)電火花加工機(jī)床。 。Electrical discharge machiningElectrical discharge machining has proved especially valuable in the machining of supertough, electrically conductive materials such as the new spaceage alloys. These metals would have been difficult to machine by conventional methods, but EDM has made it relatively simple to machine intricate shapes that would be impossible to produce with conventional cutting tools. This machining process is continually finding further applications in the metalcutting industry. It is being used extensively in the plastic industry to produce cavities of almost any shape in the steel molds. Electrical discharge machining is a controlled metal removal technique whereby an electric spark is used to cut (erode) the workpiece, which takes a shape opposite to that of the cutting tool or electrode. The cutting tool (electrode) is made from electrically conductive material, usually carbon. The electrode, made to the shape of the cavity required, and the workpiece are both submerged in a dielectric fluid, which is generally a light lubricating oil. This dielectric fluid should be a nonconductor (or poor conductor) of electricity. A servo mechanism maintains a gap of about to in. ( to mm) between the electrode and the work, preventing them from ing into contact with each other. A direct current of low voltage and high amperage is delivered to the electrode at the rate of approximately 20 000 hertz (Hz). These electrical energy impulses bee sparks which jump the dielectric fluid. Intense heat is created in the localized area of the park impact, the metal melts and a small particle of molten metal is expelled from the surface of the workpiece . The dielectric fluid, which is constantly being circulated, carries away the eroded particles of metal and also assists in dissipating the heat caused by the spark.In the last few years, major advances have been made with regard to the surface finishes that can be produced. With the low metal removal rates, surface finishes of 2 to 4 um. ( to ) are possible. With high metal removal rates finishes of 1 000uin. (25um) are produced.The type of finish required determines the number of amperes which can be used, the capacitance, frequency, and the voltage setting. For fast metal removal (roughing cuts), high amperage, low frequency, high capacitance, and minimum gap voltage are required. For slow metal removal (finish cut) and good surface finish, low amperage, high frequency, low capacitance, and the highest gap voltage are required.Electrical discharge machining has many advantages over conventional machining processes.1. Any material that is electrically conductive can be cut, regardless of its hardness. It is especially valuable for cemented carbides and the new supertough spaceage alloys that are extremely difficult to cut by conventional means.2. Work can be machined in a hardened state, thereby overing the deformation caused by the hardening process.3. Broken taps or drills can readily be removed from workpieces. 4. It does not create stresses in the work material since the tool (electrode) never es in contact with the work.5. The process is burrfree.6. Thin, fragile sections can be easily machined without deforming.7. Secondary finishing operations are generally eliminated for many types of work.8. The process is automatic in that the servomechanism advances the electrode into the work as the metal is removed.9. One person can operate several EDM machines at one time.10. Intricate shapes, impossible to produce by conventional means, are cut out of a solid with relative ease.11. Better dies and molds can be produced at lower costs.12. A die punch can be used as the electrode to reproduce its shape in the matching die plate, plete with the necessary clearance.