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。這實際上是陽江電磁鐵原(yuan)理的最(zui)初發(fa)現。1823年，斯(si)特(te)金(jin)也做了(le)(le)一(yi)次類似(si)的實驗(yan)：他在(zai)一(yi)根并非是(shi)磁(ci)鐵(tie)(tie)(tie)棒的U型鐵(tie)(tie)(tie)棒上繞(rao)了(le)(le)18圈(quan)銅(tong)(tong)裸線，當銅(tong)(tong)線與伏打電池(chi)接通時，繞(rao)在(zai)U型鐵(tie)(tie)(tie)棒上的銅(tong)(tong)線圈(quan)即產生了(le)(le)密集的磁(ci)場(chang)，這樣就使U型鐵(tie)(tie)(tie)棒變成了(le)(le)一(yi)塊(kuai)“電磁(ci)鐵(tie)(tie)(tie)”。這種電磁(ci)鐵(tie)(tie)(tie)上的磁(ci)能要比永(yong)磁(ci)能大放多(duo)倍(bei)，它能吸起比它重20倍(bei)的鐵(tie)(tie)(tie)塊(kuai)，而當電源(yuan)切(qie)斷(duan)后，U型鐵(tie)(tie)(tie)棒就什(shen)么鐵(tie)(tie)(tie)塊(kuai)也吸不(bu)住，重新(xin)成為一(yi)根普通的鐵(tie)(tie)(tie)棒。

斯特(te)金的(de)(de)電磁鐵發明，使人們看(kan)到了把電能(neng)轉化(hua)為磁能(neng)的(de)(de)光(guang)明前景(jing)，這一(yi)發明很快在英國(guo)(guo)、美國(guo)(guo)以及西(xi)歐一(yi)些(xie)沿海國(guo)(guo)家(jia)傳播開來(lai)。

1829年(nian)，美國電學家亨利對斯特金電磁(ci)鐵裝置進(jin)行了一些革新，絕緣導(dao)線代替(ti)裸(luo)銅(tong)導(dao)線，因此不必擔心被銅(tong)導(dao)線過分靠(kao)近而短(duan)路。由(you)于(yu)導(dao)線有了絕緣層，就(jiu)可以將(jiang)它們(men)一圈(quan)(quan)圈(quan)(quan)地(di)緊緊地(di)繞在(zai)一起，由(you)于(yu)線圈(quan)(quan)越(yue)密集(ji)，產生(sheng)的(de)磁(ci)場就(jiu)越(yue)強，這(zhe)樣就(jiu)大大提高(gao)了把(ba)電能(neng)轉化為磁(ci)能(neng)的(de)能(neng)力(li)。到了1831年(nian)，亨利試制出(chu)了一塊(kuai)更新的(de)電磁(ci)鐵，雖然它的(de)體(ti)積并(bing)不大，但它能(neng)吸起1噸重的(de)鐵塊(kuai)。

電磁(ci)(ci)(ci)(ci)(ci)鐵(tie)內部帶有(you)(you)鐵(tie)心(xin)的(de)(de)、利用(yong)(yong)通有(you)(you)電流(liu)(liu)的(de)(de)線圈(quan)使(shi)其(qi)像磁(ci)(ci)(ci)(ci)(ci)鐵(tie)一(yi)樣具有(you)(you)磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)裝置叫做電磁(ci)(ci)(ci)(ci)(ci)鐵(tie)，通常制成條形或(huo)蹄形。鐵(tie)心(xin)要用(yong)(yong)容易磁(ci)(ci)(ci)(ci)(ci)化，又(you)容易消失磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)軟鐵(tie)或(huo)硅鋼來(lai)制做。這樣的(de)(de)電磁(ci)(ci)(ci)(ci)(ci)鐵(tie)在通電時有(you)(you)磁(ci)(ci)(ci)(ci)(ci)性(xing)，斷(duan)電后就隨之消失。 電磁(ci)(ci)(ci)(ci)(ci)鐵(tie)有(you)(you)許多(duo)優點(dian)：電磁(ci)(ci)(ci)(ci)(ci)鐵(tie)磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)有(you)(you)無，可以用(yong)(yong)通、斷(duan)電流(liu)(liu)控(kong)制。磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)大小可以用(yong)(yong)電流(liu)(liu)的(de)(de)強弱或(huo)線圈(quan)的(de)(de)匝數來(lai)控(kong)制。

電磁鐵的主要特點

1、采用全密封結(jie)構，防潮性能(neng)好。

2、經計算機優化設(she)計，結構合理、自重輕、吸力大、能耗(hao)低。

3、勵(li)磁線圈經特別工藝(yi)處理，提(ti)高了線圈的(de)電器和(he)機(ji)械(xie)性能，絕(jue)緣(yuan)資料(liao)熱等級(ji)到達C級(ji)，運用(yong)壽命長。

4、普(pu)通(tong)(tong)型電(dian)磁(ci)鐵(tie)的(de)額定通(tong)(tong)電(dian)持續率由(you)曩(nang)昔(xi)的(de)50%提高到60%，提高了電(dian)磁(ci)鐵(tie)的(de)運用功率。

5、超高溫(wen)型電磁鐵(tie)(tie)采用獨特隔熱(re)方式，其間被(bei)吸物(wu)溫(wen)度有曩昔(xi)的600℃提(ti)高700℃，擴大了電磁鐵(tie)(tie)的適用范圍。

6、裝(zhuang)置(zhi)、運轉、保護簡潔(jie)。

電磁鐵工作原理

將(jiang)電(dian)(dian)(dian)磁(ci)(ci)能變換為機(ji)械(xie)能以(yi)實(shi)現(xian)吸(xi)合作(zuo)功(gong)的(de)(de)一種電(dian)(dian)(dian)器。通(tong)(tong)常由軟磁(ci)(ci)材(cai)料制成(cheng)的(de)(de)鐵(tie)心、銜(xian)鐵(tie)和勵磁(ci)(ci)繞組組成(cheng)。當勵磁(ci)(ci)繞組通(tong)(tong)電(dian)(dian)(dian)時(shi)，繞組周圍產生(sheng)(sheng)磁(ci)(ci)場，鐵(tie)心磁(ci)(ci)化，并(bing)產生(sheng)(sheng)電(dian)(dian)(dian)磁(ci)(ci)吸(xi)力吸(xi)引(yin)銜(xian)鐵(tie)，使(shi)之(zhi)運動作(zuo)功(gong)。電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)主(zhu)要用(yong)(yong)于操(cao)動、牽(qian)引(yin)機(ji)械(xie)裝置，以(yi)達(da)到預期的(de)(de)目的(de)(de)。工業上常用(yong)(yong)的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)有制動電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)、牽(qian)引(yin)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)、起重電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)和閥用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)等。此外(wai)，屬于電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)類(lei)的(de)(de)還有用(yong)(yong)以(yi)傳遞或隔斷兩軸間的(de)(de)機(ji)械(xie)聯(lian)系(xi)的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)聯(lian)軸器;用(yong)(yong)在機(ji)床(chuang)工作(zuo)臺上以(yi)吸(xi)牢磁(ci)(ci)性材(cai)料工件的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)吸(xi)盤;供高能物(wu)理(li)、核(he)聚(ju)變研究、磁(ci)(ci)流體發電(dian)(dian)(dian)和高速(su)懸浮列車等方面使(shi)用(yong)(yong)的(de)(de)、能產生(sheng)(sheng)高達(da)數十特（斯拉）的(de)(de)磁(ci)(ci)通(tong)(tong)密度而幾乎不消耗繞組功(gong)率的(de)(de)超導(dao)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)等。

起重電磁鐵

用來吊運和裝(zhuang)卸鐵(tie)(tie)(tie)磁(ci)(ci)(ci)性物體的電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)。工(gong)業上常用以(yi)吊運或(huo)裝(zhuang)卸鐵(tie)(tie)(tie)礦石、鐵(tie)(tie)(tie)砂、廢鋼(gang)鐵(tie)(tie)(tie)、鋼(gang)錠、鋼(gang)軌(gui)以(yi)及各種鋼(gang)材和鋼(gang)質(zhi)(zhi)工(gong)件。起重電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常做(zuo)成圓盤形(xing)或(huo)矩形(xing)，并帶有內(nei)(nei)磁(ci)(ci)(ci)極(ji)和外磁(ci)(ci)(ci)極(ji)。當勵磁(ci)(ci)(ci)繞組通電后，內(nei)(nei)外磁(ci)(ci)(ci)極(ji)均(jun)被磁(ci)(ci)(ci)化，吸引鋼(gang)質(zhi)(zhi)材料或(huo)工(gong)件（相當于一般(ban)電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)中(zhong)的銜(xian)鐵(tie)(tie)(tie)），形(xing)成一個閉合的磁(ci)(ci)(ci)路。為保護勵磁(ci)(ci)(ci)繞組，使(shi)之不因磁(ci)(ci)(ci)極(ji)與被吸引物體間的機械撞擊所(suo)損傷，起重電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常采用甲殼式結(jie)構，并且采用直流勵磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引(yin)(yin)和推斥(chi)機(ji)(ji)械(xie)(xie)裝置(zhi)用(yong)(yong)的(de)(de)一種電磁(ci)鐵(tie)(tie)(tie)。主(zhu)要用(yong)(yong)于各種自動(dong)設備中，以實現遠距離控制。為了能夠在長行(xing)程下獲得較大的(de)(de)電磁(ci)吸力，牽(qian)引(yin)(yin)電磁(ci)鐵(tie)(tie)(tie)一般(ban)采(cai)用(yong)(yong)吸引(yin)(yin)特性(xing)比較平坦的(de)(de)甲殼式結(jie)構(gou)(gou)。其內(nei)部裝有(you)鐵(tie)(tie)(tie)心、銜(xian)(xian)鐵(tie)(tie)(tie)和勵(li)磁(ci)線圈。使用(yong)(yong)時，將鐵(tie)(tie)(tie)心固定在機(ji)(ji)械(xie)(xie)裝置(zhi)的(de)(de)靜(jing)止部件上，銜(xian)(xian)鐵(tie)(tie)(tie)則連接在牽(qian)引(yin)(yin)桿上。當勵(li)磁(ci)繞組(zu)通電后，鐵(tie)(tie)(tie)心被磁(ci)化，產生電磁(ci)吸力吸引(yin)(yin)銜(xian)(xian)鐵(tie)(tie)(tie)，后者則通過牽(qian)引(yin)(yin)桿來操縱所控制的(de)(de)機(ji)(ji)械(xie)(xie)裝置(zhi)的(de)(de)機(ji)(ji)構(gou)(gou)。為了適應不同控制對象的(de)(de)需(xu)要，牽(qian)引(yin)(yin)電磁(ci)鐵(tie)(tie)(tie)有(you)拉動(dong)式和推動(dong)式兩種，但(dan)都不具備復位裝置(zhi)。牽(qian)引(yin)(yin)電磁(ci)鐵(tie)(tie)(tie)的(de)(de)主(zhu)要技術指(zhi)標為一定行(xing)程下的(de)(de)電磁(ci)吸力、操作頻(pin)率(lv)和壽命。

制動電磁鐵

作(zuo)(zuo)機(ji)械制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)用的(de)(de)一(yi)種電(dian)(dian)磁(ci)鐵(tie)。主要(yao)用于電(dian)(dian)力驅(qu)動(dong)(dong)(dong)(dong)(dong)(dong)裝置和(he)(he)起重(zhong)運輸設備中，并(bing)與(yu)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)配合使用，使電(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)準(zhun)確停車和(he)(he)懸吊著(zhu)的(de)(de)重(zhong)物不致墜(zhui)落。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)按銜(xian)鐵(tie)行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)分(fen)為(wei)長(chang)行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)和(he)(he)短行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)兩類(lei);按勵磁(ci)方式(shi)分(fen)為(wei)直流和(he)(he)交流、并(bing)勵和(he)(he)串(chuan)勵以及單(dan)相和(he)(he)三相等(deng)種類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)的(de)(de)工作(zuo)(zuo)原理是：當電(dian)(dian)磁(ci)鐵(tie)的(de)(de)繞組(zu)通(tong)(tong)(tong)電(dian)(dian)后，銜(xian)鐵(tie)被(bei)吸(xi)向鐵(tie)心，并(bing)通(tong)(tong)(tong)過(guo)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)中的(de)(de)停檔壓迫制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)桿，使之移(yi)動(dong)(dong)(dong)(dong)(dong)(dong)，從而迫使制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)松閘(zha)。切斷線圈電(dian)(dian)源后，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)桿在彈簧作(zuo)(zuo)用下使銜(xian)鐵(tie)脫離磁(ci)軛，而制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)則將(jiang)機(ji)構(gou)剎(cha)住。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)的(de)(de)主要(yao)技術參數(shu)是行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)、一(yi)定行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)下的(de)(de)電(dian)(dian)磁(ci)吸(xi)力、操作(zuo)(zuo)頻率和(he)(he)通(tong)(tong)(tong)電(dian)(dian)持(chi)續率。操作(zuo)(zuo)頻率是指每小時(shi)操作(zuo)(zuo)的(de)(de)次數(shu);通(tong)(tong)(tong)電(dian)(dian)持(chi)續率是指每次通(tong)(tong)(tong)電(dian)(dian)時(shi)間(jian)與(yu)每次通(tong)(tong)(tong)電(dian)(dian)及不通(tong)(tong)(tong)電(dian)(dian)時(shi)間(jian)之和(he)(he)的(de)(de)百分(fen)比。使用中，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)與(yu)瓦式(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合時(shi)用短行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)類(lei);與(yu)皮(pi)帶制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合時(shi)用長(chang)行(xing)(xing)程(cheng)(cheng)(cheng)(cheng)類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)通(tong)(tong)(tong)過(guo)液(ye)壓方式(shi)將(jiang)電(dian)(dian)磁(ci)力傳遞給(gei)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)構(gou)的(de)(de)稱液(ye)壓制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)。

閥用電磁鐵

供遠距離操作(zuo)(zuo)各(ge)種(zhong)液(ye)(ye)壓、氣動(dong)系(xi)統閥(fa)門的電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。常用(yong)于各(ge)種(zhong)金(jin)屬切(qie)削機床(chuang)中。閥(fa)用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)不設(she)復(fu)位裝置，而(er)由閥(fa)體(ti)中的彈簧(huang)使(shi)之復(fu)位。當(dang)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的勵(li)磁(ci)(ci)(ci)繞(rao)組通過電(dian)(dian)(dian)(dian)流時，電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)力即克服彈簧(huang)阻(zu)力，使(shi)閥(fa)體(ti)的推(tui)桿(gan)移動(dong)，將閥(fa)門開啟;當(dang)勵(li)磁(ci)(ci)(ci)繞(rao)組斷電(dian)(dian)(dian)(dian)后(hou)，在復(fu)位彈簧(huang)作(zuo)(zuo)用(yong)下，閥(fa)體(ti)推(tui)桿(gan)便推(tui)動(dong)銜(xian)鐵(tie)(tie)，使(shi)其移動(dong)額定行程(cheng)處，閥(fa)門關閉(bi)。閥(fa)用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)分為濕式和干式兩種(zhong)。濕式閥(fa)用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的銜(xian)鐵(tie)(tie)在液(ye)(ye)壓油(you)中工作(zuo)(zuo)，由于油(you)的冷(leng)卻作(zuo)(zuo)用(yong)，使(shi)其與具(ju)有相(xiang)同吸(xi)力的電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)相(xiang)比，有較小的尺寸(cun)。

電磁鐵的應用

門(men)(men)(men)禁(jin)：為什(shen)么門(men)(men)(men)禁(jin)可以在(zai)沒刷(shua)卡時把門(men)(men)(men)牢牢的(de)(de)(de)“抓住(zhu)”？原來單元門(men)(men)(men)是(shi)由鋼材料(liao)做成的(de)(de)(de)，那個金屬(shu)體在(zai)通(tong)電時可以產(chan)生強大的(de)(de)(de)磁場，產(chan)生的(de)(de)(de)磁力(li)能(neng)把門(men)(men)(men)牢牢的(de)(de)(de)吸住(zhu)，而(er)刷(shua)卡的(de)(de)(de)瞬間，切斷電流，金屬(shu)體失去磁性，我們就可以打開門(men)(men)(men)了。那個金屬(shu)體其實是(shi)一塊電磁鐵。

電磁起(qi)(qi)(qi)重(zhong)機(ji)：最直(zhi)接的(de)應用之一是電磁起(qi)(qi)(qi)重(zhong)機(ji)。電磁鐵(tie)安裝在吊(diao)車上，通電后(hou)吸(xi)起(qi)(qi)(qi)大(da)量(liang)鋼鐵(tie)，移動(dong)到另一個位(wei)置后(hou)切斷(duan)電流，鋼鐵(tie)被放下，免去了打捆的(de)麻煩。大(da)型電磁起(qi)(qi)(qi)重(zhong)機(ji)一次(ci)可以(yi)吊(diao)起(qi)(qi)(qi)幾噸(dun)鋼材。

在電(dian)動機(ji)、發電(dian)機(ji)、電(dian)鈴和電(dian)磁繼電(dian)器(qi)里也(ye)用到電(dian)磁鐵。全自動洗衣機(ji)的(de)進水(shui)(shui)、排水(shui)(shui)閥門(men)，衛生(sheng)間里感應式(shi)沖水(shui)(shui)器(qi)的(de)閥門(men)，也(ye)都是由電(dian)磁鐵控制的(de)。

電(dian)磁(ci)鐵的另(ling)一個應(ying)用(yong)是產生(sheng)強(qiang)磁(ci)場(chang)。現(xian)代技術中(zhong)很多地方需要的強(qiang)磁(ci)場(chang)都由電(dian)磁(ci)鐵提供，如大型電(dian)動機、發電(dian)機、磁(ci)療(liao)設(she)備等。