電磁鐵的發明

1822年，法國物理學家阿拉戈和呂薩克發現，當電流通過其中有鐵塊的繞線時，它能使繞線中的鐵塊磁化。這實際上是新疆電磁鐵原理的(de)(de)最(zui)初發現(xian)。1823年，斯特金也做了(le)一(yi)次類似的(de)(de)實(shi)驗(yan)：他在一(yi)根并非是磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)的(de)(de)U型(xing)(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)上(shang)(shang)繞(rao)了(le)18圈(quan)銅(tong)裸線，當銅(tong)線與伏(fu)打電(dian)池(chi)接通時，繞(rao)在U型(xing)(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)上(shang)(shang)的(de)(de)銅(tong)線圈(quan)即產生了(le)密集的(de)(de)磁(ci)(ci)場，這(zhe)樣就(jiu)使U型(xing)(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)變(bian)成(cheng)了(le)一(yi)塊“電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)”。這(zhe)種電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)上(shang)(shang)的(de)(de)磁(ci)(ci)能要比(bi)(bi)永磁(ci)(ci)能大放多倍，它能吸起比(bi)(bi)它重20倍的(de)(de)鐵(tie)(tie)(tie)(tie)(tie)(tie)塊，而(er)當電(dian)源切斷后，U型(xing)(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)就(jiu)什么鐵(tie)(tie)(tie)(tie)(tie)(tie)塊也吸不住，重新成(cheng)為一(yi)根普通的(de)(de)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)。

斯特金的電磁鐵發(fa)明，使人們看到了(le)把電能轉化為磁能的光(guang)明前景，這一發(fa)明很(hen)快在英國(guo)、美國(guo)以及西歐一些沿海國(guo)家傳播(bo)開來。

1829年，美(mei)國電(dian)學家亨(heng)利對斯特金電(dian)磁(ci)鐵(tie)裝置進(jin)行了(le)一些革新(xin)，絕緣(yuan)導(dao)線(xian)(xian)代替裸(luo)銅(tong)導(dao)線(xian)(xian)，因此不必擔心(xin)被銅(tong)導(dao)線(xian)(xian)過(guo)分靠近而(er)短路。由(you)于導(dao)線(xian)(xian)有(you)了(le)絕緣(yuan)層，就(jiu)(jiu)可以(yi)將它(ta)們一圈(quan)(quan)圈(quan)(quan)地緊緊地繞(rao)在一起，由(you)于線(xian)(xian)圈(quan)(quan)越(yue)(yue)密(mi)集，產生的(de)磁(ci)場就(jiu)(jiu)越(yue)(yue)強(qiang)，這(zhe)樣就(jiu)(jiu)大大提高(gao)了(le)把(ba)電(dian)能(neng)轉化為磁(ci)能(neng)的(de)能(neng)力。到了(le)1831年，亨(heng)利試制(zhi)出了(le)一塊(kuai)更新(xin)的(de)電(dian)磁(ci)鐵(tie)，雖(sui)然它(ta)的(de)體(ti)積并不大，但(dan)它(ta)能(neng)吸起1噸重(zhong)的(de)鐵(tie)塊(kuai)。

電(dian)磁(ci)(ci)鐵(tie)內(nei)部帶有(you)鐵(tie)心的(de)、利(li)用通(tong)有(you)電(dian)流(liu)的(de)線圈使其(qi)像磁(ci)(ci)鐵(tie)一樣(yang)具有(you)磁(ci)(ci)性(xing)的(de)裝置(zhi)叫做電(dian)磁(ci)(ci)鐵(tie)，通(tong)常制成條形(xing)或(huo)蹄形(xing)。鐵(tie)心要用容易磁(ci)(ci)化，又容易消(xiao)失(shi)磁(ci)(ci)性(xing)的(de)軟(ruan)鐵(tie)或(huo)硅鋼(gang)來制做。這樣(yang)的(de)電(dian)磁(ci)(ci)鐵(tie)在通(tong)電(dian)時有(you)磁(ci)(ci)性(xing)，斷電(dian)后就隨之(zhi)消(xiao)失(shi)。 電(dian)磁(ci)(ci)鐵(tie)有(you)許多優(you)點：電(dian)磁(ci)(ci)鐵(tie)磁(ci)(ci)性(xing)的(de)有(you)無，可以用通(tong)、斷電(dian)流(liu)控制。磁(ci)(ci)性(xing)的(de)大小可以用電(dian)流(liu)的(de)強弱(ruo)或(huo)線圈的(de)匝(za)數來控制。

電磁鐵的主要特點

1、采(cai)用全密(mi)封結構(gou)，防潮(chao)性能好。

2、經計(ji)算機優化設計(ji)，結構合理、自重輕、吸力(li)大、能耗低。

3、勵(li)磁(ci)線圈經特別工藝(yi)處理，提高(gao)了線圈的電器和機械(xie)性(xing)能，絕緣(yuan)資料(liao)熱(re)等級到(dao)達C級，運用壽命長。

4、普通(tong)型電磁鐵的額定(ding)通(tong)電持續率由曩(nang)昔的50%提高到60%，提高了電磁鐵的運用功率。

5、超高(gao)溫型電磁鐵(tie)采用獨特隔(ge)熱方(fang)式，其(qi)間(jian)被吸物溫度有(you)曩昔的600℃提高(gao)700℃，擴大了(le)電磁鐵(tie)的適用范圍。

6、裝置、運轉、保護(hu)簡潔(jie)。

電磁鐵工作原理

將電(dian)(dian)磁(ci)(ci)(ci)(ci)能變換為機(ji)械(xie)能以(yi)(yi)實現吸(xi)(xi)合作功(gong)的(de)一(yi)種電(dian)(dian)器。通常由(you)軟磁(ci)(ci)(ci)(ci)材(cai)料(liao)制成的(de)鐵(tie)(tie)(tie)心、銜(xian)鐵(tie)(tie)(tie)和勵磁(ci)(ci)(ci)(ci)繞組(zu)組(zu)成。當(dang)勵磁(ci)(ci)(ci)(ci)繞組(zu)通電(dian)(dian)時，繞組(zu)周圍產生磁(ci)(ci)(ci)(ci)場，鐵(tie)(tie)(tie)心磁(ci)(ci)(ci)(ci)化(hua)，并產生電(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)吸(xi)(xi)引(yin)銜(xian)鐵(tie)(tie)(tie)，使(shi)之運動作功(gong)。電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)主(zhu)要用于操動、牽(qian)引(yin)機(ji)械(xie)裝置，以(yi)(yi)達到預期的(de)目的(de)。工業上(shang)常用的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)有制動電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、牽(qian)引(yin)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、起重電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)和閥用電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等。此(ci)外，屬于電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)類(lei)的(de)還有用以(yi)(yi)傳遞(di)或隔斷(duan)兩軸間的(de)機(ji)械(xie)聯(lian)系的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)聯(lian)軸器;用在機(ji)床工作臺上(shang)以(yi)(yi)吸(xi)(xi)牢(lao)磁(ci)(ci)(ci)(ci)性材(cai)料(liao)工件的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)盤;供高能物理、核聚變研究、磁(ci)(ci)(ci)(ci)流體發(fa)電(dian)(dian)和高速懸浮(fu)列車等方面使(shi)用的(de)、能產生高達數十特（斯(si)拉）的(de)磁(ci)(ci)(ci)(ci)通密度而幾乎不消耗繞組(zu)功(gong)率的(de)超導電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等。

起重電磁鐵

用(yong)來(lai)吊(diao)運和(he)裝卸鐵(tie)(tie)(tie)(tie)磁(ci)(ci)(ci)(ci)性物體(ti)的(de)(de)電磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)。工(gong)業上常用(yong)以吊(diao)運或裝卸鐵(tie)(tie)(tie)(tie)礦(kuang)石、鐵(tie)(tie)(tie)(tie)砂、廢鋼(gang)鐵(tie)(tie)(tie)(tie)、鋼(gang)錠、鋼(gang)軌(gui)以及各種(zhong)鋼(gang)材(cai)(cai)和(he)鋼(gang)質工(gong)件(jian)(jian)。起重電磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)通常做成圓盤形或矩形，并(bing)帶有(you)內磁(ci)(ci)(ci)(ci)極和(he)外(wai)磁(ci)(ci)(ci)(ci)極。當勵磁(ci)(ci)(ci)(ci)繞(rao)組通電后，內外(wai)磁(ci)(ci)(ci)(ci)極均(jun)被磁(ci)(ci)(ci)(ci)化(hua)，吸引(yin)鋼(gang)質材(cai)(cai)料或工(gong)件(jian)(jian)（相當于一(yi)般電磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)中的(de)(de)銜鐵(tie)(tie)(tie)(tie)），形成一(yi)個閉合的(de)(de)磁(ci)(ci)(ci)(ci)路(lu)。為保護(hu)勵磁(ci)(ci)(ci)(ci)繞(rao)組，使之(zhi)不因(yin)磁(ci)(ci)(ci)(ci)極與被吸引(yin)物體(ti)間(jian)的(de)(de)機械撞擊所損傷(shang)，起重電磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)通常采(cai)用(yong)甲殼式結構，并(bing)且(qie)采(cai)用(yong)直流勵磁(ci)(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引和(he)推(tui)斥(chi)機(ji)械(xie)裝(zhuang)置用(yong)的(de)(de)一(yi)種(zhong)(zhong)電磁(ci)(ci)鐵(tie)(tie)。主(zhu)要(yao)用(yong)于各種(zhong)(zhong)自(zi)動(dong)設備(bei)中，以實現遠距(ju)離(li)控(kong)(kong)制。為(wei)了能夠在(zai)長行(xing)程(cheng)下(xia)獲得較大的(de)(de)電磁(ci)(ci)吸(xi)力(li)，牽(qian)引電磁(ci)(ci)鐵(tie)(tie)一(yi)般采用(yong)吸(xi)引特性比(bi)較平坦的(de)(de)甲(jia)殼式(shi)結構。其內部裝(zhuang)有鐵(tie)(tie)心、銜鐵(tie)(tie)和(he)勵磁(ci)(ci)線圈(quan)。使(shi)用(yong)時，將(jiang)鐵(tie)(tie)心固定在(zai)機(ji)械(xie)裝(zhuang)置的(de)(de)靜止(zhi)部件上，銜鐵(tie)(tie)則(ze)連接在(zai)牽(qian)引桿(gan)上。當勵磁(ci)(ci)繞組通電后(hou)，鐵(tie)(tie)心被磁(ci)(ci)化，產生電磁(ci)(ci)吸(xi)力(li)吸(xi)引銜鐵(tie)(tie)，后(hou)者則(ze)通過(guo)牽(qian)引桿(gan)來操(cao)縱所控(kong)(kong)制的(de)(de)機(ji)械(xie)裝(zhuang)置的(de)(de)機(ji)構。為(wei)了適應不同控(kong)(kong)制對(dui)象的(de)(de)需要(yao)，牽(qian)引電磁(ci)(ci)鐵(tie)(tie)有拉動(dong)式(shi)和(he)推(tui)動(dong)式(shi)兩種(zhong)(zhong)，但都不具備(bei)復位裝(zhuang)置。牽(qian)引電磁(ci)(ci)鐵(tie)(tie)的(de)(de)主(zhu)要(yao)技術(shu)指標為(wei)一(yi)定行(xing)程(cheng)下(xia)的(de)(de)電磁(ci)(ci)吸(xi)力(li)、操(cao)作(zuo)頻(pin)率(lv)和(he)壽命(ming)。

制動電磁鐵

作(zuo)(zuo)機(ji)械制(zhi)動(dong)(dong)(dong)用(yong)的(de)一(yi)種(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)。主(zhu)要用(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力驅動(dong)(dong)(dong)裝置和(he)(he)(he)(he)起重運輸設備中，并(bing)與(yu)(yu)制(zhi)動(dong)(dong)(dong)器(qi)(qi)配合使用(yong)，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)準確停車和(he)(he)(he)(he)懸吊著的(de)重物不致墜落。制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)按銜(xian)鐵(tie)(tie)(tie)(tie)行(xing)程(cheng)(cheng)(cheng)分為長(chang)行(xing)程(cheng)(cheng)(cheng)和(he)(he)(he)(he)短(duan)行(xing)程(cheng)(cheng)(cheng)兩類(lei);按勵磁(ci)(ci)(ci)(ci)(ci)方(fang)式分為直流和(he)(he)(he)(he)交流、并(bing)勵和(he)(he)(he)(he)串勵以及單相(xiang)和(he)(he)(he)(he)三相(xiang)等種(zhong)類(lei)。制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)的(de)工作(zuo)(zuo)原理是(shi)：當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)的(de)繞組通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)后(hou)，銜(xian)鐵(tie)(tie)(tie)(tie)被(bei)吸向鐵(tie)(tie)(tie)(tie)心，并(bing)通(tong)(tong)(tong)(tong)過制(zhi)動(dong)(dong)(dong)器(qi)(qi)中的(de)停檔壓迫制(zhi)動(dong)(dong)(dong)桿，使之移(yi)動(dong)(dong)(dong)，從而迫使制(zhi)動(dong)(dong)(dong)器(qi)(qi)松(song)閘。切斷線圈電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)后(hou)，制(zhi)動(dong)(dong)(dong)桿在彈簧作(zuo)(zuo)用(yong)下使銜(xian)鐵(tie)(tie)(tie)(tie)脫離磁(ci)(ci)(ci)(ci)(ci)軛，而制(zhi)動(dong)(dong)(dong)器(qi)(qi)則(ze)將機(ji)構(gou)剎住(zhu)。制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)的(de)主(zhu)要技術參數是(shi)行(xing)程(cheng)(cheng)(cheng)、一(yi)定行(xing)程(cheng)(cheng)(cheng)下的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)吸力、操(cao)作(zuo)(zuo)頻率和(he)(he)(he)(he)通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續率。操(cao)作(zuo)(zuo)頻率是(shi)指(zhi)每小時(shi)(shi)操(cao)作(zuo)(zuo)的(de)次數;通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續率是(shi)指(zhi)每次通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間與(yu)(yu)每次通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及不通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間之和(he)(he)(he)(he)的(de)百分比。使用(yong)中，制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)與(yu)(yu)瓦式制(zhi)動(dong)(dong)(dong)器(qi)(qi)相(xiang)配合時(shi)(shi)用(yong)短(duan)行(xing)程(cheng)(cheng)(cheng)類(lei);與(yu)(yu)皮帶制(zhi)動(dong)(dong)(dong)器(qi)(qi)相(xiang)配合時(shi)(shi)用(yong)長(chang)行(xing)程(cheng)(cheng)(cheng)類(lei)。制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)通(tong)(tong)(tong)(tong)過液壓方(fang)式將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)力傳遞給(gei)制(zhi)動(dong)(dong)(dong)機(ji)構(gou)的(de)稱液壓制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)。

閥用電磁鐵

供遠距離操作各(ge)種液壓、氣動(dong)(dong)系統閥(fa)門(men)的(de)電(dian)磁(ci)(ci)(ci)鐵(tie)。常用于(yu)各(ge)種金屬切削機床中(zhong)(zhong)。閥(fa)用電(dian)磁(ci)(ci)(ci)鐵(tie)不設復(fu)位裝(zhuang)置，而(er)由閥(fa)體(ti)中(zhong)(zhong)的(de)彈簧使之復(fu)位。當電(dian)磁(ci)(ci)(ci)鐵(tie)的(de)勵(li)磁(ci)(ci)(ci)繞(rao)組通(tong)過(guo)電(dian)流時，電(dian)磁(ci)(ci)(ci)吸(xi)力(li)(li)即克服(fu)彈簧阻(zu)力(li)(li)，使閥(fa)體(ti)的(de)推(tui)桿移(yi)動(dong)(dong)，將閥(fa)門(men)開啟(qi);當勵(li)磁(ci)(ci)(ci)繞(rao)組斷電(dian)后，在復(fu)位彈簧作用下(xia)，閥(fa)體(ti)推(tui)桿便推(tui)動(dong)(dong)銜(xian)鐵(tie)，使其移(yi)動(dong)(dong)額定行程處(chu)，閥(fa)門(men)關閉。閥(fa)用電(dian)磁(ci)(ci)(ci)鐵(tie)分為濕(shi)式(shi)(shi)和干式(shi)(shi)兩種。濕(shi)式(shi)(shi)閥(fa)用電(dian)磁(ci)(ci)(ci)鐵(tie)的(de)銜(xian)鐵(tie)在液壓油中(zhong)(zhong)工作，由于(yu)油的(de)冷卻作用，使其與具有相同吸(xi)力(li)(li)的(de)電(dian)磁(ci)(ci)(ci)鐵(tie)相比，有較小的(de)尺寸。

電磁鐵的應用

門(men)禁：為(wei)什么門(men)禁可(ke)以在沒刷卡(ka)時(shi)把(ba)門(men)牢(lao)(lao)牢(lao)(lao)的“抓住(zhu)”？原來單元門(men)是(shi)由鋼材料做成的，那個金屬(shu)體在通電時(shi)可(ke)以產生強大(da)的磁場，產生的磁力能把(ba)門(men)牢(lao)(lao)牢(lao)(lao)的吸住(zhu)，而刷卡(ka)的瞬(shun)間，切斷電流，金屬(shu)體失(shi)去(qu)磁性，我們(men)就可(ke)以打開門(men)了。那個金屬(shu)體其實是(shi)一塊(kuai)電磁鐵。

電(dian)磁(ci)(ci)起(qi)重機：最直接的(de)應用之一是(shi)電(dian)磁(ci)(ci)起(qi)重機。電(dian)磁(ci)(ci)鐵安裝在吊(diao)車上，通電(dian)后吸起(qi)大量鋼(gang)鐵，移(yi)動到另一個位置后切斷電(dian)流，鋼(gang)鐵被(bei)放下，免去(qu)了打(da)捆的(de)麻煩。大型(xing)電(dian)磁(ci)(ci)起(qi)重機一次(ci)可以(yi)吊(diao)起(qi)幾噸鋼(gang)材。

在電動(dong)機(ji)、發電機(ji)、電鈴和(he)電磁(ci)繼(ji)電器里也用到(dao)電磁(ci)鐵。全(quan)自動(dong)洗(xi)衣機(ji)的進水、排(pai)水閥門(men)，衛生(sheng)間里感應式沖水器的閥門(men)，也都是由電磁(ci)鐵控(kong)制(zhi)的。

電(dian)磁鐵的另一個應用是產生強(qiang)磁場(chang)。現代技術中(zhong)很多地方(fang)需(xu)要的強(qiang)磁場(chang)都由(you)電(dian)磁鐵提供，如(ru)大(da)型電(dian)動機(ji)(ji)、發電(dian)機(ji)(ji)、磁療設備等(deng)。