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。這實際上是北京電磁鐵原理(li)的(de)(de)最初發現(xian)。1823年，斯特金也(ye)做了(le)一(yi)次類似的(de)(de)實驗：他在(zai)一(yi)根并(bing)非是磁(ci)(ci)鐵(tie)棒的(de)(de)U型(xing)(xing)鐵(tie)棒上繞(rao)了(le)18圈銅裸線(xian)，當銅線(xian)與伏打電池接通(tong)時，繞(rao)在(zai)U型(xing)(xing)鐵(tie)棒上的(de)(de)銅線(xian)圈即產(chan)生了(le)密集的(de)(de)磁(ci)(ci)場，這樣(yang)就使U型(xing)(xing)鐵(tie)棒變成了(le)一(yi)塊(kuai)“電磁(ci)(ci)鐵(tie)”。這種電磁(ci)(ci)鐵(tie)上的(de)(de)磁(ci)(ci)能(neng)(neng)要比永磁(ci)(ci)能(neng)(neng)大放多倍，它(ta)能(neng)(neng)吸起比它(ta)重20倍的(de)(de)鐵(tie)塊(kuai)，而當電源(yuan)切斷(duan)后(hou)，U型(xing)(xing)鐵(tie)棒就什么(me)鐵(tie)塊(kuai)也(ye)吸不住，重新(xin)成為一(yi)根普通(tong)的(de)(de)鐵(tie)棒。

斯特金的電磁鐵發明，使(shi)人(ren)們看到了把電能(neng)轉化為磁能(neng)的光明前景，這一發明很快在英國、美國以(yi)及西歐一些沿海(hai)國家傳播(bo)開(kai)來。

1829年(nian)，美國電學家亨利(li)(li)對斯特金電磁(ci)鐵(tie)裝置進行了一些革(ge)新(xin)，絕緣(yuan)導線代替裸(luo)銅導線，因此不必(bi)擔心被銅導線過(guo)分靠近而短(duan)路(lu)。由于導線有了絕緣(yuan)層(ceng)，就(jiu)可以將(jiang)它們一圈圈地緊緊地繞在(zai)一起，由于線圈越(yue)密(mi)集，產(chan)生的(de)(de)(de)磁(ci)場就(jiu)越(yue)強，這樣就(jiu)大大提高了把電能轉(zhuan)化為磁(ci)能的(de)(de)(de)能力。到了1831年(nian)，亨利(li)(li)試制出(chu)了一塊(kuai)更新(xin)的(de)(de)(de)電磁(ci)鐵(tie)，雖然它的(de)(de)(de)體積并不大，但它能吸起1噸(dun)重的(de)(de)(de)鐵(tie)塊(kuai)。

電磁(ci)(ci)鐵(tie)內部帶有(you)(you)(you)鐵(tie)心的(de)、利用(yong)通(tong)有(you)(you)(you)電流的(de)線圈(quan)使其(qi)像磁(ci)(ci)鐵(tie)一樣具有(you)(you)(you)磁(ci)(ci)性的(de)裝置叫(jiao)做電磁(ci)(ci)鐵(tie)，通(tong)常制成條形(xing)或蹄形(xing)。鐵(tie)心要用(yong)容(rong)易磁(ci)(ci)化，又容(rong)易消失(shi)磁(ci)(ci)性的(de)軟鐵(tie)或硅鋼來制做。這樣的(de)電磁(ci)(ci)鐵(tie)在(zai)通(tong)電時有(you)(you)(you)磁(ci)(ci)性，斷電后就隨之消失(shi)。 電磁(ci)(ci)鐵(tie)有(you)(you)(you)許(xu)多優點：電磁(ci)(ci)鐵(tie)磁(ci)(ci)性的(de)有(you)(you)(you)無，可(ke)以用(yong)通(tong)、斷電流控(kong)制。磁(ci)(ci)性的(de)大小可(ke)以用(yong)電流的(de)強弱或線圈(quan)的(de)匝數來控(kong)制。

電磁鐵的主要特點

1、采用(yong)全密封結(jie)構，防潮(chao)性(xing)能好。

2、經(jing)計算(suan)機優化設計，結構合理、自重輕(qing)、吸力大、能(neng)耗低。

3、勵磁(ci)線(xian)圈(quan)經特別工藝處理，提高了線(xian)圈(quan)的(de)電器和機械性能，絕緣(yuan)資(zi)料熱等級到達(da)C級，運用壽命長。

4、普通型(xing)電磁鐵的(de)(de)額定通電持續(xu)率由曩(nang)昔的(de)(de)50%提(ti)高到60%，提(ti)高了(le)電磁鐵的(de)(de)運用(yong)功率。

5、超高溫型(xing)電磁(ci)鐵采(cai)用獨特隔(ge)熱方式(shi)，其間被吸物溫度有曩昔的600℃提高700℃，擴大(da)了電磁(ci)鐵的適用范圍。

6、裝(zhuang)置(zhi)、運轉、保(bao)護簡潔(jie)。

電磁鐵工作原理

將電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)能變換為(wei)機(ji)械(xie)能以實現(xian)吸合作(zuo)功(gong)的(de)(de)(de)(de)一種電(dian)(dian)(dian)(dian)(dian)器。通(tong)常由軟磁(ci)(ci)(ci)(ci)材料(liao)制(zhi)成(cheng)的(de)(de)(de)(de)鐵(tie)(tie)心(xin)、銜(xian)鐵(tie)(tie)和(he)勵磁(ci)(ci)(ci)(ci)繞組組成(cheng)。當勵磁(ci)(ci)(ci)(ci)繞組通(tong)電(dian)(dian)(dian)(dian)(dian)時，繞組周圍產(chan)生(sheng)磁(ci)(ci)(ci)(ci)場，鐵(tie)(tie)心(xin)磁(ci)(ci)(ci)(ci)化，并產(chan)生(sheng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸力吸引銜(xian)鐵(tie)(tie)，使之(zhi)運動作(zuo)功(gong)。電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)主(zhu)要(yao)用(yong)(yong)于(yu)(yu)操動、牽引機(ji)械(xie)裝置，以達(da)到預期的(de)(de)(de)(de)目的(de)(de)(de)(de)。工(gong)業上常用(yong)(yong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)有制(zhi)動電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)、牽引電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)、起重電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)和(he)閥用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)等。此外，屬于(yu)(yu)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)類的(de)(de)(de)(de)還有用(yong)(yong)以傳遞或隔斷兩軸(zhou)(zhou)間的(de)(de)(de)(de)機(ji)械(xie)聯系的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)聯軸(zhou)(zhou)器;用(yong)(yong)在機(ji)床工(gong)作(zuo)臺上以吸牢磁(ci)(ci)(ci)(ci)性材料(liao)工(gong)件的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸盤;供高能物理、核聚變研究、磁(ci)(ci)(ci)(ci)流體發電(dian)(dian)(dian)(dian)(dian)和(he)高速懸浮(fu)列(lie)車等方面使用(yong)(yong)的(de)(de)(de)(de)、能產(chan)生(sheng)高達(da)數(shu)十特（斯拉）的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)通(tong)密度而幾(ji)乎不消耗繞組功(gong)率的(de)(de)(de)(de)超導電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)等。

起重電磁鐵

用(yong)(yong)來吊運和裝卸(xie)鐵(tie)(tie)(tie)磁(ci)(ci)(ci)性(xing)物(wu)體的(de)電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)。工業上常用(yong)(yong)以吊運或(huo)裝卸(xie)鐵(tie)(tie)(tie)礦石(shi)、鐵(tie)(tie)(tie)砂(sha)、廢鋼(gang)鐵(tie)(tie)(tie)、鋼(gang)錠、鋼(gang)軌以及各種鋼(gang)材和鋼(gang)質工件(jian)。起(qi)重電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常做成圓盤形或(huo)矩(ju)形，并帶有內磁(ci)(ci)(ci)極和外(wai)磁(ci)(ci)(ci)極。當勵(li)磁(ci)(ci)(ci)繞(rao)組通電后，內外(wai)磁(ci)(ci)(ci)極均被(bei)磁(ci)(ci)(ci)化，吸引鋼(gang)質材料或(huo)工件(jian)（相當于一(yi)般(ban)電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)中的(de)銜鐵(tie)(tie)(tie)），形成一(yi)個(ge)閉合的(de)磁(ci)(ci)(ci)路(lu)。為保(bao)護勵(li)磁(ci)(ci)(ci)繞(rao)組，使之(zhi)不因磁(ci)(ci)(ci)極與被(bei)吸引物(wu)體間的(de)機(ji)械撞擊所損傷，起(qi)重電磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常采用(yong)(yong)甲殼(ke)式結構，并且采用(yong)(yong)直(zhi)流(liu)勵(li)磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)(qian)(qian)引(yin)(yin)和(he)推斥機械裝(zhuang)置用(yong)的(de)(de)一(yi)種(zhong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。主要(yao)用(yong)于各種(zhong)自動設備(bei)中(zhong)，以實現(xian)遠(yuan)距離控制。為(wei)(wei)了能夠(gou)在長行程(cheng)下獲得較大的(de)(de)電(dian)磁(ci)(ci)吸(xi)力，牽(qian)(qian)(qian)引(yin)(yin)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)一(yi)般(ban)采用(yong)吸(xi)引(yin)(yin)特(te)性比較平坦(tan)的(de)(de)甲殼(ke)式(shi)結構。其內部裝(zhuang)有(you)鐵(tie)(tie)(tie)心、銜鐵(tie)(tie)(tie)和(he)勵磁(ci)(ci)線圈。使(shi)用(yong)時，將鐵(tie)(tie)(tie)心固定在機械裝(zhuang)置的(de)(de)靜止部件上，銜鐵(tie)(tie)(tie)則連接在牽(qian)(qian)(qian)引(yin)(yin)桿上。當勵磁(ci)(ci)繞組通(tong)(tong)電(dian)后(hou)，鐵(tie)(tie)(tie)心被(bei)磁(ci)(ci)化，產生電(dian)磁(ci)(ci)吸(xi)力吸(xi)引(yin)(yin)銜鐵(tie)(tie)(tie)，后(hou)者則通(tong)(tong)過牽(qian)(qian)(qian)引(yin)(yin)桿來操縱所(suo)控制的(de)(de)機械裝(zhuang)置的(de)(de)機構。為(wei)(wei)了適應不(bu)同(tong)控制對象的(de)(de)需(xu)要(yao)，牽(qian)(qian)(qian)引(yin)(yin)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)有(you)拉(la)動式(shi)和(he)推動式(shi)兩(liang)種(zhong)，但都不(bu)具備(bei)復位裝(zhuang)置。牽(qian)(qian)(qian)引(yin)(yin)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)主要(yao)技術指標為(wei)(wei)一(yi)定行程(cheng)下的(de)(de)電(dian)磁(ci)(ci)吸(xi)力、操作(zuo)頻率和(he)壽命。

制動電磁鐵

作(zuo)機(ji)械制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)用(yong)(yong)的(de)(de)一種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。主要用(yong)(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力驅動(dong)(dong)(dong)裝置(zhi)和起重運輸設備中，并(bing)與(yu)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器配合使用(yong)(yong)，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)準確(que)停車和懸(xuan)吊(diao)著(zhu)的(de)(de)重物(wu)不(bu)致墜落。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)按銜(xian)鐵(tie)(tie)(tie)行(xing)(xing)(xing)程分(fen)為(wei)長行(xing)(xing)(xing)程和短(duan)(duan)行(xing)(xing)(xing)程兩類;按勵磁(ci)(ci)方式(shi)分(fen)為(wei)直流(liu)和交流(liu)、并(bing)勵和串勵以及(ji)單相(xiang)和三相(xiang)等種類。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)工作(zuo)原理(li)是：當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)繞組通(tong)(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)后，銜(xian)鐵(tie)(tie)(tie)被吸向鐵(tie)(tie)(tie)心，并(bing)通(tong)(tong)(tong)(tong)(tong)過制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器中的(de)(de)停檔(dang)壓迫制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿(gan)，使之(zhi)移動(dong)(dong)(dong)，從而(er)迫使制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器松(song)閘。切斷線(xian)圈電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)后，制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿(gan)在彈簧(huang)作(zuo)用(yong)(yong)下使銜(xian)鐵(tie)(tie)(tie)脫離磁(ci)(ci)軛(e)，而(er)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器則將機(ji)構(gou)剎住(zhu)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)主要技(ji)術參(can)數是行(xing)(xing)(xing)程、一定(ding)行(xing)(xing)(xing)程下的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)吸力、操(cao)作(zuo)頻率和通(tong)(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續率。操(cao)作(zuo)頻率是指每(mei)小時操(cao)作(zuo)的(de)(de)次數;通(tong)(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續率是指每(mei)次通(tong)(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間與(yu)每(mei)次通(tong)(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)不(bu)通(tong)(tong)(tong)(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間之(zhi)和的(de)(de)百分(fen)比(bi)。使用(yong)(yong)中，制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)與(yu)瓦式(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器相(xiang)配合時用(yong)(yong)短(duan)(duan)行(xing)(xing)(xing)程類;與(yu)皮(pi)帶(dai)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器相(xiang)配合時用(yong)(yong)長行(xing)(xing)(xing)程類。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)通(tong)(tong)(tong)(tong)(tong)過液壓方式(shi)將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)力傳遞給(gei)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)機(ji)構(gou)的(de)(de)稱(cheng)液壓制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。

閥用電磁鐵

供(gong)遠距離操作(zuo)(zuo)(zuo)各種(zhong)液(ye)壓(ya)、氣動系統閥(fa)(fa)門(men)的(de)電(dian)(dian)磁鐵(tie)(tie)(tie)(tie)。常用于各種(zhong)金屬切削機床中(zhong)。閥(fa)(fa)用電(dian)(dian)磁鐵(tie)(tie)(tie)(tie)不設復位(wei)裝(zhuang)置，而由閥(fa)(fa)體中(zhong)的(de)彈簧使(shi)之(zhi)復位(wei)。當電(dian)(dian)磁鐵(tie)(tie)(tie)(tie)的(de)勵磁繞組通過電(dian)(dian)流(liu)時，電(dian)(dian)磁吸(xi)力即克服彈簧阻力，使(shi)閥(fa)(fa)體的(de)推桿移動，將閥(fa)(fa)門(men)開啟;當勵磁繞組斷電(dian)(dian)后，在復位(wei)彈簧作(zuo)(zuo)(zuo)用下，閥(fa)(fa)體推桿便(bian)推動銜鐵(tie)(tie)(tie)(tie)，使(shi)其移動額定行程處，閥(fa)(fa)門(men)關(guan)閉(bi)。閥(fa)(fa)用電(dian)(dian)磁鐵(tie)(tie)(tie)(tie)分為濕式和干(gan)式兩種(zhong)。濕式閥(fa)(fa)用電(dian)(dian)磁鐵(tie)(tie)(tie)(tie)的(de)銜鐵(tie)(tie)(tie)(tie)在液(ye)壓(ya)油(you)(you)中(zhong)工作(zuo)(zuo)(zuo)，由于油(you)(you)的(de)冷卻作(zuo)(zuo)(zuo)用，使(shi)其與(yu)具有相同吸(xi)力的(de)電(dian)(dian)磁鐵(tie)(tie)(tie)(tie)相比，有較(jiao)小的(de)尺寸。

電磁鐵的應用

門(men)(men)禁(jin)：為什么門(men)(men)禁(jin)可以(yi)在沒刷卡時(shi)把門(men)(men)牢牢的(de)(de)“抓(zhua)住”？原來(lai)單(dan)元(yuan)門(men)(men)是(shi)由鋼材料做成的(de)(de)，那(nei)個(ge)(ge)金(jin)屬體(ti)(ti)在通電(dian)時(shi)可以(yi)產生強大的(de)(de)磁(ci)場(chang)，產生的(de)(de)磁(ci)力能(neng)把門(men)(men)牢牢的(de)(de)吸(xi)住，而(er)刷卡的(de)(de)瞬間，切斷電(dian)流(liu)，金(jin)屬體(ti)(ti)失去磁(ci)性，我們就(jiu)可以(yi)打開門(men)(men)了。那(nei)個(ge)(ge)金(jin)屬體(ti)(ti)其實是(shi)一塊電(dian)磁(ci)鐵。

電(dian)磁(ci)起(qi)重(zhong)機：最直接的(de)應用之一(yi)是電(dian)磁(ci)起(qi)重(zhong)機。電(dian)磁(ci)鐵安裝(zhuang)在(zai)吊車上(shang)，通電(dian)后吸(xi)起(qi)大(da)量鋼鐵，移動到另一(yi)個(ge)位置后切斷(duan)電(dian)流(liu)，鋼鐵被放下，免(mian)去了打捆(kun)的(de)麻煩。大(da)型電(dian)磁(ci)起(qi)重(zhong)機一(yi)次可以吊起(qi)幾噸鋼材。

在電(dian)(dian)動機、發電(dian)(dian)機、電(dian)(dian)鈴和電(dian)(dian)磁繼(ji)電(dian)(dian)器里也(ye)用到(dao)電(dian)(dian)磁鐵。全自動洗衣機的(de)進(jin)水、排(pai)水閥門，衛生間里感應式沖水器的(de)閥門，也(ye)都是(shi)由電(dian)(dian)磁鐵控制(zhi)的(de)。

電(dian)(dian)磁(ci)(ci)(ci)鐵的另一個應用是產(chan)生強(qiang)磁(ci)(ci)(ci)場。現代技術中很多地(di)方需要的強(qiang)磁(ci)(ci)(ci)場都由電(dian)(dian)磁(ci)(ci)(ci)鐵提(ti)供，如大型電(dian)(dian)動(dong)機(ji)、發電(dian)(dian)機(ji)、磁(ci)(ci)(ci)療設備等。