60年代(dai),隨著電池制(zhi)造(zao)技術的發展,出現了用(yong)鎳鎘電池作電源的無電源線的電池式電動工具。但當時因價格昂貴,發展較慢。到70年代中后期,因電池價格降低,充電時間也縮短,這種電動工具在歐美、日(ri)本得到廣泛使用。電動(dong)工(gong)具(ju)(ju)最(zui)初用鑄鐵作外殼,后改(gai)用鋁合金作外殼。60年代,熱塑性工(gong)程塑料在電動(dong)工(gong)具(ju)(ju)上獲得應用,并實現了(le)電動(dong)工(gong)具(ju)(ju)的雙重絕(jue)緣(yuan),保障了(le)(le)電(dian)(dian)(dian)動工(gong)具(ju)(ju)的(de)使用(yong)安全性。由于電(dian)(dian)(dian)子技術的(de)發展(zhan),60年代(dai)還出(chu)現了(le)(le)電(dian)(dian)(dian)子調速電(dian)(dian)(dian)動工(gong)具(ju)(ju)。這(zhe)種電(dian)(dian)(dian)動工(gong)具(ju)(ju)利用(yong)晶閘管等元件(jian)組成電(dian)(dian)(dian)子線路,以(yi)開關撳鈕被撳入(ru)的深(shen)度不同(tong)(tong)(tong)來調節轉速,從而使(shi)電動工具在使(shi)用時(shi)能按被加工對(dui)象(xiang)的不同(tong)(tong)(tong)(如(ru)材料不同(tong)(tong)(tong)、鉆孔直徑(jing)大小等),選擇不同(tong)(tong)(tong)的轉速。
選購電動工具應注意的事項,首先電動工具是一種由電(dian)動(dong)機或電(dian)磁鐵為(wei)動(dong)力,通(tong)過傳動(dong)機構驅動(dong)工(gong)作(zuo)(zuo)頭(tou)進行(xing)作(zuo)(zuo)業的(de)手持式或可移式的(de)機械化工(gong)具。電(dian)動(dong)工(gong)具具有攜帶方便、操作(zuo)(zuo)簡單、功能多樣等特點,可(ke)以大(da)大(da)減輕勞動強(qiang)度,提(ti)高工作(zuo)效率,實現手工操(cao)作(zuo)機(ji)械化,因(yin)而被廣泛應用(yong)于(yu)建(jian)筑、住房(fang)裝(zhuang)潢、汽(qi)車、機(ji)械、電(dian)力、橋梁(liang)、園藝等領域(yu),并大(da)量進入(ru)家庭。電動(dong)工具的(de)特點是結構輕巧,體積(ji)小(xiao)、重量輕、振動(dong)小(xiao)、噪(zao)聲低、運(yun)轉靈活,便(bian)于控(kong)制與操作,攜帶使用方便(bian),堅固及耐用。與手(shou)動(dong)工具相比可提高勞動生(sheng)產率(lv)數倍到數十倍;比風動工(gong)具(ju)效率(lv)高,費(fei)用低(di)和易于控制(zhi)。