0440-步進式加熱爐同步頂升液壓控制系統(tǒng)設計【全套7張CAD圖】

0440-步進式加熱爐同步頂升液壓控制系統(tǒng)設計【全套7張CAD圖】,全套7張CAD圖,步進,加熱爐,同步,液壓,控制系統(tǒng),設計,全套,cad 緒論 1 緒論 1.1 步進式加熱爐 1.1.1 步進式加熱爐概述 隨著西方資本主義社會在18世紀進入工業(yè)革命以來，社會的發(fā)展進入到了一個全新的速度。據(jù)統(tǒng)計在工業(yè)革命以前世界上人均鋼鐵的使用量是不足5kg。然而，現(xiàn)在的社會發(fā)展到人均鋼鐵擁有量為418kg。越來越多的鋼結構出現(xiàn)在社會建設中。所以鋼鐵一直是現(xiàn)在社會發(fā)展的主要材料。甚至一度到了供不應求的狀況。這樣就促使了鋼鐵產業(yè)的迅速壯大。至2007年，世界鋼鐵量已經(jīng)達到了近九億噸。但是由于技術有限，加上人們對鋼鐵的運用越加廣泛，出現(xiàn)對鋼材更多更新的要求。所以鋼鐵的冶煉技術要不斷地改良。 1967 年第1 座步進梁式加熱爐投產。中國1979年投產的步進梁式爐長為32.5米，生產能力為每小時270頓。步進梁式爐比推鋼爐具有許多優(yōu)點，因而成為新建軋鋼廠的首選爐型。熱軋寬帶鋼廠的規(guī)模正向大型化發(fā)展，步進梁式爐的特點之一是爐長不受推鋼長度限制，因而能適應軋機的小時產量增長的形勢。北京鋼鐵設計研究總院近20 年設計投產的40 余座步進爐，已遍及熱連軋、型鋼、棒線材、帶鋼、無縫管、開坯、鍛壓等鋼廠以及鋼帶廠，1994年相繼投產的太鋼、梅山熱連軋廠的步進梁式爐，額定產量分別為180 t/ h 和280 t/ h ，重慶鋼鐵設計研究院為攀鋼1450 熱連軋廠設計的步進梁式爐，額定產量為150 t/ h ，也在1992 年投產。 早期加熱爐內部是用一種連續(xù)式推鋼機，它的作用是將鋼錠或鋼坯依次推入爐內。在端出料的加熱爐中，推鋼機可以將加熱好的鋼坯從加熱爐的另一端推出去。在側出料的加熱爐中，推鋼機將鋼坯推出至出料位置，再由出鋼機將鋼錠推出去；現(xiàn)在大多數(shù)采用的是步進式移動裝置。步進式加熱爐加熱溫度均勻，加熱時間快，產量高，生產靈活性大，必要時可以將爐內坯料排空。加熱時，坯料下表面的水管黑印小，坯料溫度均勻，加熱的效率也比較高。加熱特殊鋼材是，能滿足對坯料表面質量（氧化、脫碳、劃傷等）的高度要求；加熱大型板材時，由于板坯溫度均勻，有利于減少軋制時的厚度差。所以目前步進式爐在熱軋板帶車間以及中小型軋鋼車間都得到了廣泛的應用。 從上世紀50年代起由于步進式加熱爐移動裝置的出現(xiàn)并且日漸成熟，在許多鋼板和小型型鋼生產中得到了很好的應用。作為現(xiàn)代冶金行業(yè)普遍采用的一種加熱爐，他的優(yōu)點值得我們學習。 步進式加熱爐的結構 A、爐底結構 從爐子的結構看，步進式加熱爐分為上加熱步進式爐、上下加熱步進式爐、雙步進梁步進式爐等。 上加熱步進式爐顧名思義只有上部有加熱裝置，固定梁和移動梁是耐熱金屬制作的，固定爐底是耐火材料砌筑的。這種爐子基本上沒有水冷構件，所以熱耗較低。這種爐子只能單面加熱，一般用于較薄鋼坯的加熱。 與推鋼式加熱爐一樣，為了滿足加熱大鋼坯的需要，步進式爐也逐步發(fā)展了下加熱的方式，出現(xiàn)了上下加熱的步進式加熱爐。這種爐子相當于把推鋼式爐的爐底水管改成了固定梁和移動梁。固定梁和移動梁都是用水冷立管支承的。梁也由水冷管構成，外面用耐火可塑性包扎，上面有耐熱合金的鞍座式滑軌，類似推鋼式加熱爐的爐底縱水管。爐底是架空的，可以實現(xiàn)雙面加熱（步進式爐鋼坯與鋼坯不是緊靠在一起，中間有空隙，可認為是四面受熱）。下加熱一般只能用側燒嘴，因為立柱擋住了端燒嘴火焰的方向，如果要采用端燒嘴，需要改變立柱的結構型式。上加熱可以用軸向端燒嘴，也可以用側燒嘴或爐頂燒嘴供熱?？紤]到軸向燒嘴火焰沿長度方向的溫度分布和各段溫度的控制，某些大型步進式爐在上加熱各段之間的邊界上有明顯的爐頂壓下，而下加熱各段間設有段墻，以免各段之間溫度的干擾；因此這樣的步進式爐沿爐子長度溫度調節(jié)有更大的靈活性，如果爐子寬度較大，火焰長度又較短時，可以在爐頂上安裝平焰燒嘴。 B、傳動機構 步進式爐的關鍵設備是移動梁的傳動機構。傳動方式分機械傳動和液壓傳動兩種。目前廣泛采用液壓傳動的方式?，F(xiàn)代大型加熱爐的移動梁及上面的鋼坯重達數(shù)百噸，使用液壓傳動機構運行穩(wěn)定，結構簡單，運行速度的控制比較準確，占地面積小，設備重量輕，比機械傳動有明顯的優(yōu)點。液壓傳動機構如圖2-12所示。圖2-12b、圖2-12c、圖2-12d三種結構型式目前是比較常見的。我國應用較普遍為圖2-12c所示的斜塊滑輪式。以斜塊滑輪式為例說明其動作的原理：步進梁（移動梁）由升降用的下步進梁和進退用的上步梁兩部分組成。上步進梁通過輥輪作用在下步進梁上，下步進梁通過傾斜滑塊支承在輥子上。上下步進梁分別由兩個液壓油缸驅動，開始時上步進梁固定不動，上升液壓缸驅動下步進梁沿滑塊斜面抬高，完成上升運動。然后上升液壓缸使下步進梁固定不動，水平液壓缸牽動上步進梁沿水平方向前進，前進行程完結時，以同樣方式完成下降和后退的動作，結束一個運動周期。 為了避免升降過程中的振動和沖擊，在上升和下降及接受鋼坯時，步進梁應該中間減速。水平進退時開始與停止也應該考慮緩沖減速，以保證梁的運動平穩(wěn)，避免鋼坯在梁上擦動。辦法是用變速油泵改變供油量來調整步進梁的運行速。由于步進式爐很長，上下兩面溫度差過大，線膨脹的不同會造成大梁的彎曲和隆起。為了解決這個問題，目前一些爐子將大梁分成若干段，各段間留有一定的膨脹間隙，變形雖不能根本避免，但彎曲的程度大為減輕，不致影響爐子的正常工作。 C、密封機構 為了保證步進爐活動梁（床）能正常無阻礙地運動，在活動梁（床）和固定梁（床）之間要有足夠的縫隙，縫隙一般為25mm或30mm，對步進梁來說則在梁支撐（或水管）穿過爐底部分有保證它運動的足夠大的開孔。這些縫隙或開孔的存在雖然是必要的，但也容易吸入冷風，影響加熱質量和降低燃料利用率，也可能造成爐氣外逸，危害爐底下部設備，對軋鋼用步進爐則必須考慮密封問題，目前有兩種密封結構，一是滑板式密封，一是水封，前者密封較差，尤其當滑板受熱變形后更不能起到密封作用，水封是用得最多的結構，密封效果比較好，水封由水封槽和水封刀兩部分組成，分開式和閉式兩種結構，開式結構有動床和定床二重水封刀，便于清渣；閉式結構僅有動床水封刀，優(yōu)點是占用空間小，緊湊。動床端頭水封槽的寬度要保證大于動床水平行程的長度，水槽下部開有集渣斗，由爐底縫隙中掉落的氧化鐵皮隨水流定期放出。 這里不得不提到的是，之所以在20世紀50年代才采用（相對于鋼鐵鋼鐵行業(yè)來說），是因為液壓傳動本身的特殊才致使其發(fā)展較為緩慢。到20世紀初液壓傳動技術從理論到實際運用才基本成熟。在21世紀液壓技術的運用則標志著一個國家基礎工業(yè)發(fā)展水平。在步進式加熱爐移動裝置液壓傳動系統(tǒng)中，液壓傳動作為提供動梁運動的動力源起著至關重要的作用。如何設計高質量的液壓裝置則直接成為影響鋼坯的燒結質量。 早期加熱爐內部是用一種連續(xù)式推鋼機，它的作用是將鋼錠或鋼坯依次推入爐內。在端出料的加熱爐中，推鋼機可以將加熱好的鋼坯從加熱爐的另一端推出去。在側出料的加熱爐中，推鋼機將鋼坯推出至出料位置，再由出鋼機將鋼錠推出去；現(xiàn)在大多數(shù)采用的是步進式移動裝置。步進式加熱爐加熱溫度均勻，加熱時間快，產量高，生產靈活性大，必要時可以將爐內坯料排空。加熱時，坯料下表面的水管黑印小，坯料溫度均勻，加熱的效率也比較高。加熱特殊鋼材是，能滿足對坯料表面質量（氧化、脫碳、劃傷等）的高度要求；加熱大型板材時，由于板坯溫度均勻，有利于減少軋制時的厚度差。所以目前步進式爐在熱軋板帶車間以及中小型軋鋼車間都得到了廣泛的應用。 加熱爐步進式移動裝置液壓傳動系統(tǒng)主要是由動梁和靜梁組成。當鋼坯被推進加熱爐后將其置于靜梁上的，此時鋼坯開始被加熱升溫。加熱爐是軋鋼工業(yè)必須配備的熱處理設備。隨著工業(yè)自動化技術的不斷發(fā)展，現(xiàn)代化的軋鋼廠應該配置大型化的、高度自動化的步進梁式加熱爐，其生產應符合高產、優(yōu)質、低耗、節(jié)能、無公害以及生產操作自動化的工藝要求，以提高其產品的質量，增強產品的市場競爭力?！　∥覈堜摴I(yè)的加熱爐型有推鋼式爐和步進式爐兩種，但推鋼式爐有長度短、產量低，燒損大，操作不當時會粘鋼造成生產上的問題，難以實現(xiàn)管理自動化。由于推鋼式爐有難以克服的缺點，而步進梁式爐是靠專用的步進機構，在爐內做矩形運動來移送鋼管，鋼管之間可以留出空隙，鋼管和步進梁之間沒有摩擦，出爐鋼管通過托出裝置出爐，完全消除了滑軌擦痕，鋼管加熱斷面溫差小、加熱均勻，爐長不受限制，產量高，生產操作靈活等特點，其生產符合高產、優(yōu)質、低耗、節(jié)能、無公害以及生產操作自動化的工藝要求。全連續(xù)、全自動化步進式加熱爐。 1.1.2 選題背景 軋鋼廠在熱軋鋼材時，需要對鋼坯進行加熱。為了更好的保證鋼材表面質量，使鋼坯受熱均勻，采用了步進加熱方式。 鋼坯在加熱過程中其前移為矩形運動；即活動梁上升，將鋼坯從固定梁上托起；活動梁前移，使鋼坯前步進一次；活動梁下降，將鋼坯放在固定梁上；活動梁后退到原始位置完成一個工作循環(huán)。 步進加熱克服了直推式加熱時鋼坯下表面與支撐梁（固定梁）移動摩擦所產生的表面磨損；同時，克服了直推式的鋼坯間相互靠攏的情況，可以使鋼坯散開通過爐底，有利于鋼坯的加熱。由于步進加熱獨特的優(yōu)越性，使其在現(xiàn)代冶金工廠得到了廣泛的應用。步進式鋼坯加熱爐產品質量好，熱效率高，操作靈活，適用于多種型材坯料的連續(xù)式加熱。 步進式連續(xù)加熱爐靠爐底或水冷金屬梁的上升、前進、下降、后退的動作把料坯一步一步地移送前進的連續(xù)加熱爐。爐子有固定爐底和步進爐底，或者有固定梁和步進梁。前者叫做步進底式爐，后者叫做步進梁式爐。 加熱爐爐床由固定梁和步進梁組成。步進梁由雙重輪對的多軸框架支撐，外側走輪由升降缸驅動，從而使步進梁作上升或者下降運動。上層托輪直接托住步進梁，而步進梁直接由另一液壓缸帶動，可在托輪上作前進和后退運動，從而使步進梁作前進和后退運動。 通過缸的操作，使步進梁做矩形跡運動，各段運動的形式可以調節(jié)，操作方式可以連續(xù)或者手動操作。同一液壓油源提供步進梁傳動，可以同時或交替動作；并可以逆向運動，用作為倒空爐內鋼坯之用。 液壓傳動有著其不可替代的優(yōu)越性，主要表現(xiàn)在： A、可以獲得很大的輸出力或力矩，而結構并不復雜； B、可以實現(xiàn)較大范圍的無級調速，且可在運行中直接調節(jié)； C、易于實現(xiàn)過載保護； D、動作靈敏，啟動，停止和換向響應快，沖擊小； E、自潤滑性能好； F、易于實現(xiàn)通用化，系列化和標準化，設計組裝周期短； G、易于實現(xiàn)自動化與智能化與數(shù)控技術相結合。 本課題的設計內容是設計一個步進式加熱爐同步頂升的液壓系統(tǒng)。 1.1.3 設計目的 由于步進爐的特點是步進周期短，運動速度較高，慣性負載大，連續(xù)工作，可靠性要求高等，所以根據(jù)這些特點系統(tǒng)采用液壓控制比較適宜。 當今，隨著液壓機械自動化程度的飛速發(fā)展，液壓元件應用數(shù)量急劇增加，元件小型化，系統(tǒng)集成化是必然的發(fā)展趨勢。特別是近十年來，液壓技術與傳感技術，微電子技術緊密結合，出現(xiàn)了許多諸如電液比例控制閥，數(shù)字閥，電認伺服液壓缸等機（液）電一體化元器件，使液壓技術在高壓，告訴，大功率，節(jié)能高效，低噪聲，使用壽命長，高度集成化方面取得了重大進展。 所以，隨著冶金軋鋼工藝自動化程度的不斷提高，步進式加熱爐以其靈活的加熱方式，加熱質量好，爐長不受限制，操作方便，易于實現(xiàn)自動控制等優(yōu)點，被愈來愈多新建的軋鋼加熱爐采用。液壓傳動傳動因其體積小，負荷大，易于實現(xiàn)機電一體化控制等優(yōu)勢，在步進式加熱爐中有廣泛的應用。 步進式加熱爐有著其他加熱爐無法比擬的優(yōu)點，諸如，不拱鋼，不粘鋼，氧化燒損少，脫碳少，加熱時間短，加熱操作靈活，易于和軋制節(jié)奏相匹配，加熱過程中不劃傷，爐子長度不受限制（從理論上講）自動化程度高，易于采用計算機控制等優(yōu)點。 因此盡管步進爐第一次投資費用較高，但是1967年4月由美國德蘭公司設計的二面供熱的步進梁式爐首先在美國格蘭那特城鋼鐵公司問世以來，接著同年5月由日本中外爐公司為名古屋鋼鐵廠設計的世界上第二座步進梁式爐又相繼投產，以后步進式加熱爐在世界上獲得了長足的發(fā)展。 和推鋼式連續(xù)加熱爐相比，步進式爐具有以下優(yōu)點： （1）加熱靈活。在爐長一定的情況下，爐內坯料數(shù)目是可變的。而在連續(xù)加熱爐中則是不可變的，那樣加熱時間就受到限制。例如爐子產量降低一半時，則 爐內坯料加熱時間就會延長一倍，對有些鋼種來說這是不利的，而步進爐在爐子小時產量變化的情況下可以通過改變坯料間距離來達到改變或保持加熱時間不變的目的。 （2）加熱質量好。因為在步進爐內可以使坯料間保留一定的間隙，這樣擴大了坯料受熱面，加熱溫度比較均勻，鋼坯表面一般沒有劃傷的情況，兩面加熱時坯料下表面水管黑印的影響比—般推鋼式連續(xù)加熱爐的要小些。 （3）爐長不受限制。對連續(xù)加熱爐來說爐長受到推鋼長度的限制，而步進爐則不受限制。而且對于不利于推鋼的細長坯料、圓棒、彎曲坯料等均可在步進爐內加熱。 （4）操作方便。改善了勞動條件，在必要時可以將爐內坯料全部或部分退出爐外，開爐時間可縮短；由于不容易粘鋼，因此可減輕繁重的體力勞動；和軋機配合比較方便、靈活。 （5）可以準確地控制爐內坯料的位置，便于實現(xiàn)自動化操作。 尤其是近10多年來，隨著軋鋼技術向著連續(xù)化，大型化，自動化，多品種，高精度的發(fā)展，步進式加熱爐為適應工藝的要求，也朝著大型化，多功能，高產，低消耗和操作集成自動化的方向邁進。 可以預見，隨著液壓技術的不斷進步，更加高自動化的加熱爐會被人們所應用。 1.1.4 設計方案 步進爐的機械結構采用的是斜坡滾輪式液壓傳動。水平移動和升降都由液壓缸驅動,步進框架下面的滾輪沿斜臺面升降。 這種結構有兩層框架,下層是提升框架。上層為水平移動框架。在提升框架的上面和下面均安有滾輪,每個下滾輪放在一個斜臺面上,上滾輪供平移框架移動用，移動缸通過曲柄連桿和旋轉接頭與上框架連接,提升缸用旋轉接頭直接與下框架連接。下框架用斜面輥導向,上框架用水平輥導向。 加熱爐的步進機構和液壓系統(tǒng)主要由雙層步進框架，液壓缸，液壓泵以及各種閥件組成。如圖：上一層為行進框架，下一層為升降框架。行進框架是通過支撐輥和輥道落在升降框架上，升降框架也通過支撐輥和輥道落在基礎上。當升降框架在在升降液壓缸驅動下沿斜軌道左升降運動時，步進梁和行進框架也一起作垂直方向的升降運動，在平移液壓缸的驅動下，在水平方向作進退運動，從而完成整個周期循環(huán)動作。 液壓系統(tǒng)的改進 對原有系統(tǒng)中舉升液壓缸水平拉動動梁上升的部分，可以改為將此液壓缸放置在爐底，同時讓液壓缸與上升滾輪的斜面保持同樣的斜度。這樣就有效的解決了拉力大，液壓缸有桿腔推動無桿腔做大功率運動的情況，同時也減小了液壓缸的尺寸，便于設計和安裝。 步進梁動作如圖1所示： 圖1 步進梁動作示意圖 步進梁的升降和平移均采用電液比例閥來控制，其優(yōu)點是控制調整靈活方便，工作平穩(wěn)。在設計過程中，應該考慮到步進梁平移時可能會產生很大的慣性沖擊，實現(xiàn)加速、減速、勻速，從而實現(xiàn)動梁對熱坯的輕托、輕放，以及通過加、減速有效降低動梁因運動慣性引起的機械沖擊，下降的時候依靠自身自重下降。 通過PLC編程設置加減速曲線，既避免了沖擊對設備造成的傷害，又提高了系統(tǒng)的定位精度，通過PLC控制達到同步頂升精度要求。 步進梁動作軌跡如圖2所示： 圖2 步進梁動作軌跡圖 1 introduction 1.1 Step into the furnace 1.1.1 Step into the furnace overview As western capitalist society in the 18 th century since the industrial revolution, the development of the society entered a new speed. According to the statistics in the industrial revolution in the world before the usage of the per capita steel is less than 5 kg. However, now of the social development to the ownership for 418 kg per capita steel. More and more steel structure appear in socialist construction. So steel has been now the main material of social development. And even once the shortage of supply. This prompted the steel industry is growing rapidly. To the year 2007, the world GangTieLiang has reached nearly nine hundred million tons. But because technology Co., LTD, add people to use more widely, steel emergence of steel more demand. So the steel and iron the smelting technology constantly improved. The first step in 1967 a beam furnace put into production. China 1979 years of production walking beam furnace is 32.5 meters long, production capacity of 270 tons per hour. Walking beam furnace stove than push steel have many advantages, thus become the first choice of rolling mills new furnace type. The scale of the steel rolling broadband is large development, walking beam furnace is one of the characteristics of furnace long from push steel, and can adapt to limit the length of mill production growth hour of the situation. Beijing steel design research institute nearly 20 years design of production more than 40 buildings stepping furnace, already pervaded strip, finances, great wire, strip steel, seamless tube, KaiPi, forging and other steel and steel belt factory, in 1994 have put in taigang, meishan strip factory of walking beam furnace rated output, respectively for 180 t/h and 280 t/h, chongqing iron and steel institute of design for pangang during the 1450 factory design walking beam furnace, rated output for 150 t/h, also put into production in 1992. Early heating furnace interior is a continuous type push with steel machine, it is the role of ingot or billet in turn push in charging. In the end the material, the furnace of steel machine can push will heating good from the other end of the billet reheating furnace out. In side out of the furnace of material, push the steel billet machine will be launched to the material position, again by the steel ingot machine will be out; Now most use is stepping type mobile device. Step into the furnace heating temperature even, heating time fast, high output, and big production flexibility and may, when necessary, will furnace empty blank. Heated, the blank of the surface of the water pipes under small black imprint, blank temperature even, heating efficiency is high. Heating special steel is, can be met on the surface quality of the blank (oxidation, decarburization, scratch, etc) height requirements; Heating large panel, as the slab temperature even, to reduce the thickness different rolling. So now stepping type furnace in the hot rolled strip workshop and small and medium-sized steel rolling workshop have been widely used. From the 1950 s due to step into the furnace and the emergence of the mobile devices to mature, in many steel plate and small steel production are a good application. As a modern metallurgy industry is generally used a furnace, and his advantage worth learning. Step into the structure of the furnace A, furnace bottom structure From the structure of the stove, see the step furnace is divided into heating stepping type furnace, heating up and down the step type furnace, double walking beam stepping type furnace, etc. On the step heating furnace heating device upside has only just as its name implies, fixed beam and mobile leung is heat-resistant metal production, fixed furnace bottom is refractory lining. The stove is basically no water-cooling elements, so the heat consumption is low. The stove can only single heating, general for a thin billet heating. And pushed steel as furnace, in order to meet the need of the billet heating big, stepping type furnace is also gradually development under the heating of the heat of the up and down, appeared to step into the furnace. The stove is equivalent to push steel type furnace of furnace bottom water pipe into a fixed beam and mobile beam. Fixed beam and mobile beam with water-cooled stand pipe support. By water cooling tube beam also form, with refractory plasticity bandage, outside a heat resistant alloy above the saddle type slippery course, similar to the guide on pusher-type reheating furnace of furnace bottom longitudinal pipe. Furnace bottom is of built on stilts, can realize double heating (step type furnace and billet is not close to the billet together, and there is a gap, can think is heated) all. Heating under general can only use side burner, because pillar blocking the end burner flame direction, if want to the burner, the need to change the structure of the pillar type. Heat can be used on axial end burner, you can also use the burner or top burner heating. Considering the axial burner flame along the length direction the temperature distribution and the control of the temperature, some each large step type furnace in each of the boundary between the heating furnace roof are clearly under pressure, and heating under paragraphs with between wall, in order to avoid the interference between each temperature; So this step type furnace stove temperature control along the length of the more flexibility, if the stove is larger, the flame length and width of the relatively short time, can be installed on the roof in flat flame burner. B, a transmission mechanism Stepping type furnace is the key equipment moving beam transmission mechanism. The transmission way points mechanical transmission and hydraulic pressure drive two kinds. So far as the widely used hydraulic transmission way. Modern large-scale furnace mobile beam and the above billet weighs hundreds of tons, use hydraulic transmission mechanism, stable operation, the structure is simple, the operation speed control is accurate, cover an area of an area small, equipment, light weight, than the mechanical transmission has obvious advantages. Hydraulic transmission mechanism as shown in figure 2 to 12 as shown. Figure 2 to 12 b, figure 2 to 12 c, figure 2 to 12 d three structural type is now more common. Our country to apply more common for figure 2 to 12 c shows the inclined piece of slippery wheel. To the piece of slippery wheel as an example of the action principle: walking beam (mobile beam by lifting the use under) walking beam and the crust with a beam of two parts. Crust beam through the roll wheel, the next step into the role the beam, the next step beam by tilting the slider bearing in the roll. Fluctuation walking beam respectively by two hydraulic oil cylinder driving, beginning crust beam stationary, and rising hydraulic cylinder drive walking beam along the slider cant drive up, finish up movement. Then rises hydraulic cylinder makes the next step beam stationary, and level hydraulic cylinder will affect beam along horizontal direction, forward trip ends, in the same way down the action of a back and finish, ending a movement cycle. In order to avoid in the process of lifting vibration and impact, in the up and down and accept billet, walking beam should slow down among. When a start and stop the level should be considered a buffer to slow down, to ensure the smooth movement of the beam, avoid the beam slab wipe move. Way is to change the flow of variable speed pump to adjust walking beam operation speed. Due to step into type furnace is very long, excessive temperature difference fluctuation two sides, the different linear expansion will cause the beam bending and uplift. In order to solve this problem, the beam will present some into segments, paragraphs with the expansion of the gap between certain deformation, though, but can't avoid bending degree is reduced greatly, and not affect the normal work of the stove. C, seal institutions In order to guarantee the step furnace activities (bed) can beam normal unimpeded movement in activities, (bed) and beam fixed beam (bed) to have enough between the gap, gap is commonly 25 mm or 30 mm, the step for the beam supporting beams is (or conduit) through the furnace bottom part is that it sports large enough the holes. Those cracks or although the existence of hole is necessary, but also easy to inhaled air cooling, heating quality and reduce the influence fuel efficiency, also may cause furnace gas to escape and harm the furnace of steel rolling equipment, under to step into the oven with sealing problem must be considered, there are two sealing structure, a slide type is a water seal, is, the former seal is bad, especially when a skateboard heated deformation after sealing function, couldn't be more water is the most used structure, sealed effect is better, the water seal water and water to seal groove by the sword of two parts, the separation of type and closed two kinds of structure, type structure have move bed and fixed bed double sword for clear water, slag; Closed structure only move water bed knife, take up the space is little, the advantages of compact. Move the width of the slot water bed end to ensure that more than moving bed the length of the water level, the trip has set a slag, open by a crack in the furnace bottom dropped oxidized scale with flow out regularly. Have to mention here, are used only in the 1950 s (relatively) steel industry, for steel because of the special hydraulic drive itself that made its develop very slowly. To the 20 th century hydraulic transmission technology from theory to practice of using just basic mature. In the 21 st century hydraulic technology application will mark a national base level of industrial development. In step furnace mobile device hydraulic transmission systems, hydraulic transmission as providing dynamic beam the power source of the sports plays a vital role. How to design and high quality hydraulic device is directly affect the quality of a billet sintering. Early heating furnace interior is a continuous type push with steel machine, it is the role of ingot or billet in turn push in charging. In the end the material, the furnace of steel machine can push will heating good from the other end of the billet reheating furnace out. In side out of the furnace of material, push the steel billet machine will be launched to the material position, again by the steel ingot machine will be out; Now most use is stepping type mobile device. Step into the furnace heating temperature even, heating time fast, high output, and big production flexibility and may, when necessary, will furnace empty blank. Heated, the blank of the surface of the water pipes under small black imprint, blank temperature even, heating efficiency is high. Heating special steel is, can be met on the surface quality of the blank (oxidation, decarburization, scratch, etc) height requirements; Heating large panel, as the slab temperature even, to reduce the thickness different rolling. So now stepping type furnace in the hot rolled strip workshop and small and medium-sized steel rolling workshop have been widely used. Heating furnace stepping type mobile device hydraulic transmission system is mainly composed of dynamic and static beam of beam. When billet reheating furnace was pushed it in the static beam, this time the billet heating temperature began to be. Heating furnace of steel rolling industry is must be equipped with heat treatment equipment. With the continuous development of industrial automation technology, modern rolling mills shall be equipped with large, highly automated walking beam furnace, the production should be consistent with high yield, good quality and low consumption, energy saving, pollution-free, and production automatic operation process requirement, in order to improve the quality of its products, enhance the market competitiveness of products. The heating furnace of steel rolling industry in our country, which has pushed steel type furnace and step into the furnace two kinds, but pushed steel type furnace is short, low yield of length, the burning of the big, improper operation will stick by the problem on the steel production to realize the automation management. Due to push steel type furnace is difficult to overcome shortcomings, and walking beam furnace is special stepping on organization, in furnace rectangular steel pipe to do exercise to leave space between, steel pipe, steel tube and can be walking beam no friction between steel pipe, come out by over to completely eliminate the device slippery course scratching, steel tube heating section temperature difference is small, even heating furnace, long is not limited, high output, and production operation is flexible and other characteristics, its production meet high yield, high quality, and low consumption, energy saving, pollution-free, and production automatic operation process requirement. The continuous, full automatic step furnace. 1.1.2 To choose a background In the hot rolling steel rolling mills, need on billet heating. In order to better ensure steel surface quality, make the billet is heated evenly, using a step heating mode. Billet heating process goes forward in the movement for rectangular; That activity, from rising beam slab fixed beam raise; Activities, before the forward beam slab step one time. Activities, will be put down beam slab fixed beam; Beam back to the original position activities to compl