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。這實際上是貴州電磁鐵原理(li)的(de)最(zui)初(chu)發現。1823年，斯特(te)金也做了(le)一次(ci)類似的(de)實驗：他在(zai)一根并(bing)非是磁鐵(tie)(tie)(tie)(tie)棒(bang)(bang)的(de)U型(xing)鐵(tie)(tie)(tie)(tie)棒(bang)(bang)上繞(rao)了(le)18圈銅裸線，當(dang)銅線與伏打電(dian)池接(jie)通(tong)時，繞(rao)在(zai)U型(xing)鐵(tie)(tie)(tie)(tie)棒(bang)(bang)上的(de)銅線圈即產生了(le)密集的(de)磁場，這(zhe)(zhe)樣(yang)就使U型(xing)鐵(tie)(tie)(tie)(tie)棒(bang)(bang)變成(cheng)了(le)一塊“電(dian)磁鐵(tie)(tie)(tie)(tie)”。這(zhe)(zhe)種電(dian)磁鐵(tie)(tie)(tie)(tie)上的(de)磁能(neng)(neng)要比永(yong)磁能(neng)(neng)大放多倍，它能(neng)(neng)吸起比它重20倍的(de)鐵(tie)(tie)(tie)(tie)塊，而當(dang)電(dian)源切斷后，U型(xing)鐵(tie)(tie)(tie)(tie)棒(bang)(bang)就什(shen)么鐵(tie)(tie)(tie)(tie)塊也吸不住，重新成(cheng)為一根普通(tong)的(de)鐵(tie)(tie)(tie)(tie)棒(bang)(bang)。

斯特金的電磁(ci)(ci)鐵發明(ming)，使人們(men)看到了把電能轉化為磁(ci)(ci)能的光(guang)明(ming)前景，這一(yi)發明(ming)很快在英國、美國以及西歐一(yi)些沿海國家(jia)傳播開來。

1829年(nian)，美(mei)國電學家(jia)亨利對斯特金(jin)電磁(ci)鐵裝置進(jin)行了(le)一(yi)些革(ge)新(xin)，絕緣導線代(dai)替裸銅(tong)導線，因此不(bu)必擔心(xin)被銅(tong)導線過分靠近而短路。由于導線有(you)了(le)絕緣層(ceng)，就(jiu)可以將它(ta)們一(yi)圈(quan)圈(quan)地緊緊地繞(rao)在一(yi)起(qi)，由于線圈(quan)越(yue)密(mi)集，產生的(de)(de)(de)磁(ci)場就(jiu)越(yue)強，這樣(yang)就(jiu)大(da)大(da)提高(gao)了(le)把電能(neng)轉(zhuan)化為磁(ci)能(neng)的(de)(de)(de)能(neng)力(li)。到了(le)1831年(nian)，亨利試制(zhi)出了(le)一(yi)塊(kuai)更新(xin)的(de)(de)(de)電磁(ci)鐵，雖然它(ta)的(de)(de)(de)體(ti)積并(bing)不(bu)大(da)，但它(ta)能(neng)吸起(qi)1噸重的(de)(de)(de)鐵塊(kuai)。

電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)內部(bu)帶(dai)有(you)(you)(you)(you)鐵(tie)(tie)心的(de)、利用通有(you)(you)(you)(you)電(dian)(dian)(dian)流(liu)的(de)線圈使其像磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)一樣具有(you)(you)(you)(you)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)性的(de)裝置叫(jiao)做(zuo)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)，通常制(zhi)成條形(xing)或(huo)蹄形(xing)。鐵(tie)(tie)心要用容易磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)化，又容易消失(shi)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)性的(de)軟鐵(tie)(tie)或(huo)硅鋼來制(zhi)做(zuo)。這(zhe)樣的(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)在通電(dian)(dian)(dian)時(shi)有(you)(you)(you)(you)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)性，斷電(dian)(dian)(dian)后就隨(sui)之(zhi)消失(shi)。 電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)有(you)(you)(you)(you)許多優點：電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)性的(de)有(you)(you)(you)(you)無，可(ke)以用通、斷電(dian)(dian)(dian)流(liu)控制(zhi)。磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)性的(de)大小可(ke)以用電(dian)(dian)(dian)流(liu)的(de)強弱或(huo)線圈的(de)匝數來控制(zhi)。

電磁鐵的主要特點

1、采用全密封結構，防潮性能好。

2、經(jing)計算(suan)機優化設計，結(jie)構合理(li)、自重輕、吸(xi)力大、能耗(hao)低。

3、勵磁線圈經特別工藝處理(li)，提高了線圈的電(dian)器和機械性能，絕(jue)緣資料熱等級到達C級，運(yun)用壽命(ming)長。

4、普通(tong)型電磁(ci)鐵的額定通(tong)電持續(xu)率(lv)由曩(nang)昔的50%提高到60%，提高了電磁(ci)鐵的運用功率(lv)。

5、超(chao)高(gao)溫(wen)型電磁(ci)鐵采用獨(du)特隔熱方式，其間(jian)被吸物溫(wen)度有曩昔(xi)的600℃提高(gao)700℃，擴大(da)了電磁(ci)鐵的適用范圍。

6、裝置、運轉、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)(ci)能變換為(wei)機(ji)(ji)(ji)械能以(yi)實現吸合(he)作功(gong)的(de)(de)(de)(de)一種電(dian)(dian)(dian)器。通(tong)常由軟磁(ci)(ci)材料制成的(de)(de)(de)(de)鐵(tie)心、銜鐵(tie)和(he)(he)勵(li)磁(ci)(ci)繞組(zu)組(zu)成。當勵(li)磁(ci)(ci)繞組(zu)通(tong)電(dian)(dian)(dian)時，繞組(zu)周(zhou)圍產生磁(ci)(ci)場，鐵(tie)心磁(ci)(ci)化，并(bing)產生電(dian)(dian)(dian)磁(ci)(ci)吸力吸引(yin)(yin)銜鐵(tie)，使之運動作功(gong)。電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)主要用(yong)于(yu)操(cao)動、牽(qian)引(yin)(yin)機(ji)(ji)(ji)械裝置，以(yi)達(da)(da)到預期的(de)(de)(de)(de)目的(de)(de)(de)(de)。工業上常用(yong)的(de)(de)(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)(yin)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)、起(qi)重(zhong)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)和(he)(he)閥用(yong)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)等。此外(wai)，屬于(yu)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)類的(de)(de)(de)(de)還有用(yong)以(yi)傳遞或隔斷兩軸間的(de)(de)(de)(de)機(ji)(ji)(ji)械聯系(xi)的(de)(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)聯軸器;用(yong)在機(ji)(ji)(ji)床工作臺上以(yi)吸牢磁(ci)(ci)性材料工件的(de)(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)吸盤;供高能物理、核聚(ju)變研(yan)究、磁(ci)(ci)流體發電(dian)(dian)(dian)和(he)(he)高速懸浮(fu)列車等方面使用(yong)的(de)(de)(de)(de)、能產生高達(da)(da)數十特（斯(si)拉）的(de)(de)(de)(de)磁(ci)(ci)通(tong)密度而幾乎不消耗繞組(zu)功(gong)率的(de)(de)(de)(de)超導(dao)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)等。

起重電磁鐵

用來吊(diao)運和裝卸鐵磁(ci)(ci)(ci)(ci)性(xing)物(wu)體的電(dian)磁(ci)(ci)(ci)(ci)鐵。工業上常(chang)用以(yi)吊(diao)運或裝卸鐵礦石(shi)、鐵砂、廢鋼(gang)(gang)鐵、鋼(gang)(gang)錠、鋼(gang)(gang)軌以(yi)及(ji)各種鋼(gang)(gang)材和鋼(gang)(gang)質(zhi)工件。起重(zhong)電(dian)磁(ci)(ci)(ci)(ci)鐵通(tong)常(chang)做成圓盤形(xing)(xing)或矩形(xing)(xing)，并(bing)帶有內磁(ci)(ci)(ci)(ci)極和外磁(ci)(ci)(ci)(ci)極。當勵磁(ci)(ci)(ci)(ci)繞(rao)組(zu)通(tong)電(dian)后，內外磁(ci)(ci)(ci)(ci)極均被(bei)磁(ci)(ci)(ci)(ci)化，吸引鋼(gang)(gang)質(zhi)材料或工件（相當于一(yi)般電(dian)磁(ci)(ci)(ci)(ci)鐵中的銜鐵），形(xing)(xing)成一(yi)個閉合的磁(ci)(ci)(ci)(ci)路。為保護勵磁(ci)(ci)(ci)(ci)繞(rao)組(zu)，使之(zhi)不因磁(ci)(ci)(ci)(ci)極與(yu)被(bei)吸引物(wu)體間的機(ji)械撞擊所損(sun)傷，起重(zhong)電(dian)磁(ci)(ci)(ci)(ci)鐵通(tong)常(chang)采用甲殼式結構，并(bing)且(qie)采用直流勵磁(ci)(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引(yin)和推(tui)(tui)斥機械(xie)裝置用(yong)的(de)(de)一(yi)種(zhong)電(dian)(dian)磁(ci)(ci)鐵(tie)(tie)。主(zhu)要(yao)(yao)用(yong)于各種(zhong)自動設備中，以實現遠距(ju)離(li)控制(zhi)(zhi)。為(wei)了能夠在長(chang)行(xing)程(cheng)下(xia)獲(huo)得(de)較大的(de)(de)電(dian)(dian)磁(ci)(ci)吸(xi)(xi)力，牽(qian)引(yin)電(dian)(dian)磁(ci)(ci)鐵(tie)(tie)一(yi)般采用(yong)吸(xi)(xi)引(yin)特性(xing)比(bi)較平坦的(de)(de)甲殼(ke)式(shi)結(jie)構(gou)。其(qi)內部(bu)裝有鐵(tie)(tie)心(xin)、銜鐵(tie)(tie)和勵磁(ci)(ci)線圈。使用(yong)時，將(jiang)鐵(tie)(tie)心(xin)固定在機械(xie)裝置的(de)(de)靜止部(bu)件上，銜鐵(tie)(tie)則(ze)連接在牽(qian)引(yin)桿上。當勵磁(ci)(ci)繞(rao)組通電(dian)(dian)后(hou)，鐵(tie)(tie)心(xin)被磁(ci)(ci)化，產生電(dian)(dian)磁(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引(yin)銜鐵(tie)(tie)，后(hou)者則(ze)通過牽(qian)引(yin)桿來操縱所(suo)控制(zhi)(zhi)的(de)(de)機械(xie)裝置的(de)(de)機構(gou)。為(wei)了適應不(bu)同控制(zhi)(zhi)對象的(de)(de)需要(yao)(yao)，牽(qian)引(yin)電(dian)(dian)磁(ci)(ci)鐵(tie)(tie)有拉動式(shi)和推(tui)(tui)動式(shi)兩種(zhong)，但都不(bu)具(ju)備復(fu)位裝置。牽(qian)引(yin)電(dian)(dian)磁(ci)(ci)鐵(tie)(tie)的(de)(de)主(zhu)要(yao)(yao)技術指標為(wei)一(yi)定行(xing)程(cheng)下(xia)的(de)(de)電(dian)(dian)磁(ci)(ci)吸(xi)(xi)力、操作頻率和壽命。

制動電磁鐵

作機(ji)械制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)用(yong)(yong)的(de)(de)(de)(de)一(yi)種電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)。主要(yao)用(yong)(yong)于電(dian)(dian)力驅動(dong)(dong)(dong)(dong)(dong)(dong)(dong)裝置和(he)(he)起重運輸設備(bei)中，并(bing)與制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)配合使用(yong)(yong)，使電(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)機(ji)準確(que)停車和(he)(he)懸吊著(zhu)的(de)(de)(de)(de)重物不致墜落。制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)按銜(xian)(xian)鐵(tie)(tie)(tie)行(xing)程(cheng)(cheng)分(fen)(fen)為長行(xing)程(cheng)(cheng)和(he)(he)短行(xing)程(cheng)(cheng)兩類(lei);按勵磁(ci)方式(shi)分(fen)(fen)為直流和(he)(he)交流、并(bing)勵和(he)(he)串勵以及單(dan)相和(he)(he)三相等種類(lei)。制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)的(de)(de)(de)(de)工作原理是(shi)(shi)：當電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)的(de)(de)(de)(de)繞組通(tong)(tong)(tong)電(dian)(dian)后，銜(xian)(xian)鐵(tie)(tie)(tie)被吸(xi)向鐵(tie)(tie)(tie)心(xin)，并(bing)通(tong)(tong)(tong)過(guo)制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)中的(de)(de)(de)(de)停檔壓(ya)迫制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)桿，使之移動(dong)(dong)(dong)(dong)(dong)(dong)(dong)，從而(er)(er)迫使制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)松(song)閘。切斷線圈電(dian)(dian)源后，制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)桿在彈簧作用(yong)(yong)下使銜(xian)(xian)鐵(tie)(tie)(tie)脫離(li)磁(ci)軛，而(er)(er)制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)則(ze)將機(ji)構(gou)剎住。制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)的(de)(de)(de)(de)主要(yao)技術(shu)參數(shu)(shu)是(shi)(shi)行(xing)程(cheng)(cheng)、一(yi)定行(xing)程(cheng)(cheng)下的(de)(de)(de)(de)電(dian)(dian)磁(ci)吸(xi)力、操作頻(pin)率和(he)(he)通(tong)(tong)(tong)電(dian)(dian)持續率。操作頻(pin)率是(shi)(shi)指(zhi)每(mei)小時(shi)操作的(de)(de)(de)(de)次數(shu)(shu);通(tong)(tong)(tong)電(dian)(dian)持續率是(shi)(shi)指(zhi)每(mei)次通(tong)(tong)(tong)電(dian)(dian)時(shi)間與每(mei)次通(tong)(tong)(tong)電(dian)(dian)及不通(tong)(tong)(tong)電(dian)(dian)時(shi)間之和(he)(he)的(de)(de)(de)(de)百分(fen)(fen)比。使用(yong)(yong)中，制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)與瓦式(shi)制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合時(shi)用(yong)(yong)短行(xing)程(cheng)(cheng)類(lei);與皮帶制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合時(shi)用(yong)(yong)長行(xing)程(cheng)(cheng)類(lei)。制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)通(tong)(tong)(tong)過(guo)液壓(ya)方式(shi)將電(dian)(dian)磁(ci)力傳遞給制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)機(ji)構(gou)的(de)(de)(de)(de)稱液壓(ya)制(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)。

閥用電磁鐵

供(gong)遠距離操作(zuo)(zuo)各種(zhong)液(ye)壓、氣(qi)動(dong)(dong)系統閥(fa)門(men)(men)的(de)(de)電(dian)(dian)磁(ci)鐵。常用(yong)(yong)(yong)于各種(zhong)金屬切削機床中。閥(fa)用(yong)(yong)(yong)電(dian)(dian)磁(ci)鐵不設復(fu)位(wei)裝置，而由閥(fa)體(ti)中的(de)(de)彈簧(huang)使之復(fu)位(wei)。當(dang)電(dian)(dian)磁(ci)鐵的(de)(de)勵磁(ci)繞(rao)組通(tong)過(guo)電(dian)(dian)流時，電(dian)(dian)磁(ci)吸力即克服彈簧(huang)阻力，使閥(fa)體(ti)的(de)(de)推桿移(yi)動(dong)(dong)，將閥(fa)門(men)(men)開(kai)啟(qi);當(dang)勵磁(ci)繞(rao)組斷電(dian)(dian)后，在復(fu)位(wei)彈簧(huang)作(zuo)(zuo)用(yong)(yong)(yong)下，閥(fa)體(ti)推桿便推動(dong)(dong)銜(xian)鐵，使其移(yi)動(dong)(dong)額定(ding)行程處，閥(fa)門(men)(men)關閉。閥(fa)用(yong)(yong)(yong)電(dian)(dian)磁(ci)鐵分為濕(shi)式(shi)(shi)(shi)和干(gan)式(shi)(shi)(shi)兩種(zhong)。濕(shi)式(shi)(shi)(shi)閥(fa)用(yong)(yong)(yong)電(dian)(dian)磁(ci)鐵的(de)(de)銜(xian)鐵在液(ye)壓油中工作(zuo)(zuo)，由于油的(de)(de)冷卻作(zuo)(zuo)用(yong)(yong)(yong)，使其與具有(you)相同(tong)吸力的(de)(de)電(dian)(dian)磁(ci)鐵相比，有(you)較小的(de)(de)尺(chi)寸(cun)。

電磁鐵的應用

門禁(jin)：為什么(me)門禁(jin)可以在沒刷(shua)卡(ka)時(shi)把(ba)(ba)門牢(lao)(lao)牢(lao)(lao)的(de)“抓住”？原來單元門是(shi)由鋼(gang)材料做(zuo)成的(de)，那個(ge)金(jin)屬體在通電(dian)時(shi)可以產生強(qiang)大的(de)磁(ci)場，產生的(de)磁(ci)力能把(ba)(ba)門牢(lao)(lao)牢(lao)(lao)的(de)吸住，而刷(shua)卡(ka)的(de)瞬間，切斷(duan)電(dian)流(liu)，金(jin)屬體失(shi)去磁(ci)性，我們就(jiu)可以打開門了。那個(ge)金(jin)屬體其實是(shi)一塊電(dian)磁(ci)鐵。

電磁(ci)(ci)起重機：最直接(jie)的應(ying)用(yong)之一(yi)是電磁(ci)(ci)起重機。電磁(ci)(ci)鐵(tie)安裝在吊車上，通電后(hou)吸起大(da)(da)量鋼(gang)鐵(tie)，移動到另(ling)一(yi)個位(wei)置(zhi)后(hou)切斷電流，鋼(gang)鐵(tie)被放下，免去了打捆(kun)的麻煩。大(da)(da)型電磁(ci)(ci)起重機一(yi)次可以吊起幾噸鋼(gang)材(cai)。

在電(dian)(dian)動(dong)機(ji)、發(fa)電(dian)(dian)機(ji)、電(dian)(dian)鈴(ling)和電(dian)(dian)磁(ci)繼電(dian)(dian)器(qi)里(li)也(ye)(ye)用到電(dian)(dian)磁(ci)鐵。全自(zi)動(dong)洗衣機(ji)的(de)進水(shui)、排水(shui)閥門，衛(wei)生間里(li)感應(ying)式沖水(shui)器(qi)的(de)閥門，也(ye)(ye)都(dou)是(shi)由電(dian)(dian)磁(ci)鐵控制(zhi)的(de)。

電(dian)磁(ci)鐵(tie)的另(ling)一個應用是產生(sheng)強(qiang)磁(ci)場(chang)。現代技(ji)術中很多地方需要(yao)的強(qiang)磁(ci)場(chang)都由電(dian)磁(ci)鐵(tie)提(ti)供，如大型電(dian)動機、發(fa)電(dian)機、磁(ci)療設備等。