砂輪電火花機工作原理是什么？

工作原理

進行電(dian)(dian)(dian)火花(hua)加工(gong)時，工(gong)具電(dian)(dian)(dian)極(ji)和工(gong)件(jian)分別接(jie)脈沖電(dian)(dian)(dian)源的(de)兩極(ji)，并浸入工(gong)作液(ye)中(zhong)，或將工(gong)作液(ye)充入放(fang)電(dian)(dian)(dian)間(jian)隙(xi)(xi)。通過間(jian)隙(xi)(xi)自動控(kong)制系統控(kong)制工(gong)具電(dian)(dian)(dian)極(ji)向工(gong)件(jian)進給，當(dang)兩電(dian)(dian)(dian)極(ji)間(jian)的(de)間(jian)隙(xi)(xi)達到(dao)一定距離(li)時，兩電(dian)(dian)(dian)極(ji)上(shang)施加的(de)脈沖電(dian)(dian)(dian)壓將工(gong)作液(ye)擊穿，產生火花(hua)放(fang)電(dian)(dian)(dian)。

在(zai)放電的(de)微細通道中(zhong)瞬時集中(zhong)大量(liang)(liang)的(de)熱能，溫(wen)度可高達10000℃以(yi)上，壓力也(ye)有急劇變化，從而使這一(yi)點工作(zuo)(zuo)(zuo)表面(mian)局部微量(liang)(liang)的(de)金(jin)屬材料立刻熔化、氣化，并爆炸式地飛濺到(dao)工作(zuo)(zuo)(zuo)液中(zhong)，迅速冷凝，形(xing)成(cheng)固體(ti)的(de)金(jin)屬微粒，被(bei)工作(zuo)(zuo)(zuo)液帶走。這時在(zai)工件表面(mian)上便留下一(yi)個微小的(de)凹坑痕跡，放電短暫停(ting)歇，兩電極間工作(zuo)(zuo)(zuo)液恢復絕緣狀(zhuang)態。

緊接著，下一個脈沖(chong)電壓又(you)在兩電極相(xiang)對接近的另一點(dian)處擊穿(chuan)，產生火花放電，重復上述(shu)過(guo)程。這樣，雖然每(mei)個脈沖(chong)放電蝕(shi)除的金屬(shu)量極少，但因每(mei)秒有(you)(you)成(cheng)千上萬次脈沖(chong)放電作(zuo)用(yong)，就(jiu)能蝕(shi)除較多的金屬(shu)，具(ju)有(you)(you)一定的生產率。

在保持工(gong)(gong)具(ju)電(dian)極與(yu)工(gong)(gong)件(jian)(jian)(jian)之間(jian)恒定放(fang)電(dian)間(jian)隙的(de)(de)(de)條件(jian)(jian)(jian)下(xia)，一邊(bian)蝕除(chu)(chu)工(gong)(gong)件(jian)(jian)(jian)金屬，一邊(bian)使工(gong)(gong)具(ju)電(dian)極不斷地向工(gong)(gong)件(jian)(jian)(jian)進給，最后便加(jia)工(gong)(gong)出(chu)與(yu)工(gong)(gong)具(ju)電(dian)極形狀相對(dui)應的(de)(de)(de)形狀來。因此(ci)，只要改變工(gong)(gong)具(ju)電(dian)極的(de)(de)(de)形狀和(he)工(gong)(gong)具(ju)電(dian)極與(yu)工(gong)(gong)件(jian)(jian)(jian)之間(jian)的(de)(de)(de)相對(dui)運動方式，就能加(jia)工(gong)(gong)出(chu)各(ge)種復雜的(de)(de)(de)型面(mian)。工(gong)(gong)具(ju)電(dian)極常(chang)用(yong)導電(dian)性(xing)良好(hao)、熔點較高(gao)、易加(jia)工(gong)(gong)的(de)(de)(de)耐電(dian)蝕材料，如銅、石(shi)墨、銅鎢合(he)金和(he)鉬等。在加(jia)工(gong)(gong)過程(cheng)中(zhong)，工(gong)(gong)具(ju)電(dian)極也有損耗(hao)，但(dan)小于工(gong)(gong)件(jian)(jian)(jian)金屬的(de)(de)(de)蝕除(chu)(chu)量，甚至接近于無損耗(hao)。

工(gong)(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)液作(zuo)(zuo)為(wei)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)介(jie)質(zhi)，在加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)過(guo)程中(zhong)(zhong)還起著冷卻、排屑等(deng)作(zuo)(zuo)用(yong)(yong)(yong)(yong)。常(chang)用(yong)(yong)(yong)(yong)的(de)(de)(de)(de)工(gong)(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)液是(shi)粘(zhan)度較低(di)、閃點較高、性(xing)能(neng)穩(wen)定的(de)(de)(de)(de)介(jie)質(zhi)，如煤油、去離(li)子(zi)水(shui)和乳化(hua)(hua)液等(deng)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)機是(shi)一種自激放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，其特點如下(xia)： 火(huo)花(hua)(hua)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)兩個電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)間在放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)前具(ju)(ju)較高的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，當兩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)接近時，其間介(jie)質(zhi)被擊(ji)穿后(hou)(hou)，隨(sui)(sui)即發生(sheng)(sheng)(sheng)火(huo)花(hua)(hua)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。伴隨(sui)(sui)擊(ji)穿過(guo)程，兩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)間的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)急劇變小(xiao)，兩極(ji)(ji)之(zhi)(zhi)間的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓也(ye)隨(sui)(sui)之(zhi)(zhi)急劇變低(di)。火(huo)花(hua)(hua)通(tong)(tong)道(dao)(dao)必(bi)須(xu)在維持暫短的(de)(de)(de)(de)時間（通(tong)(tong)常(chang)為(wei)10-7-10-3s）后(hou)(hou)及(ji)時熄滅(mie)，才可(ke)(ke)(ke)保持火(huo)花(hua)(hua)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)“冷極(ji)(ji)”特性(xing)（即通(tong)(tong)道(dao)(dao)能(neng)量(liang)(liang)(liang)轉(zhuan)換的(de)(de)(de)(de)熱能(neng)來不(bu)及(ji)傳至(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)縱深），使通(tong)(tong)道(dao)(dao)能(neng)量(liang)(liang)(liang)作(zuo)(zuo)用(yong)(yong)(yong)(yong)于極(ji)(ji)小(xiao)范圍(wei)。通(tong)(tong)道(dao)(dao)能(neng)量(liang)(liang)(liang)的(de)(de)(de)(de)作(zuo)(zuo)用(yong)(yong)(yong)(yong)，可(ke)(ke)(ke)使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)局部被腐(fu)蝕(shi)。 利用(yong)(yong)(yong)(yong)火(huo)花(hua)(hua)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時產生(sheng)(sheng)(sheng)的(de)(de)(de)(de)腐(fu)蝕(shi)現象對材(cai)(cai)(cai)料(liao)進行(xing)尺寸(cun)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)的(de)(de)(de)(de)方法，叫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)。 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)是(shi)在較低(di)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓范圍(wei)內(nei)，在液體介(jie)質(zhi)中(zhong)(zhong)的(de)(de)(de)(de)火(huo)花(hua)(hua)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong) 按照工(gong)(gong)(gong)(gong)(gong)(gong)具(ju)(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)的(de)(de)(de)(de)形式(shi)及(ji)其與(yu)工(gong)(gong)(gong)(gong)(gong)(gong)件(jian)之(zhi)(zhi)間相(xiang)對運(yun)動(dong)(dong)的(de)(de)(de)(de)特征(zheng)，可(ke)(ke)(ke)將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)方式(shi)分為(wei)五類：利用(yong)(yong)(yong)(yong)成(cheng)型(xing)工(gong)(gong)(gong)(gong)(gong)(gong)具(ju)(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)，相(xiang)對工(gong)(gong)(gong)(gong)(gong)(gong)件(jian)作(zuo)(zuo)簡單(dan)進給運(yun)動(dong)(dong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)成(cheng)形加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)；利用(yong)(yong)(yong)(yong)軸向移(yi)動(dong)(dong)的(de)(de)(de)(de)金屬(shu)絲作(zuo)(zuo)工(gong)(gong)(gong)(gong)(gong)(gong)具(ju)(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)，工(gong)(gong)(gong)(gong)(gong)(gong)件(jian)按所需形狀(zhuang)和尺寸(cun)作(zuo)(zuo)軌(gui)跡運(yun)動(dong)(dong)，以切(qie)割導電(dian)(dian)(dian)(dian)(dian)(dian)(dian)材(cai)(cai)(cai)料(liao)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)線切(qie)割加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)；利用(yong)(yong)(yong)(yong)金屬(shu)絲或成(cheng)形導電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磨(mo)(mo)輪作(zuo)(zuo)工(gong)(gong)(gong)(gong)(gong)(gong)具(ju)(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)，進行(xing)小(xiao)孔磨(mo)(mo)削(xue)(xue)(xue)或成(cheng)形磨(mo)(mo)削(xue)(xue)(xue)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)磨(mo)(mo)削(xue)(xue)(xue)；用(yong)(yong)(yong)(yong)于加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)螺紋環規、螺紋塞規  、齒輪等(deng)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)共(gong)軛(e)回轉(zhuan)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)；小(xiao)孔加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)、刻英(ying)表(biao)(biao)面(mian)合金化(hua)(hua)、表(biao)(biao)面(mian)強化(hua)(hua)等(deng)其他(ta)種類的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)火(huo)花(hua)(hua)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)能(neng)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)普(pu)通(tong)(tong)切(qie)削(xue)(xue)(xue)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)方法難以切(qie)削(xue)(xue)(xue)的(de)(de)(de)(de)材(cai)(cai)(cai)料(liao)和復雜(za)形狀(zhuang)工(gong)(gong)(gong)(gong)(gong)(gong)件(jian)；加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)時無(wu)切(qie)削(xue)(xue)(xue)力；不(bu)產生(sheng)(sheng)(sheng)毛刺和刀痕溝紋等(deng)缺陷；工(gong)(gong)(gong)(gong)(gong)(gong)具(ju)(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)材(cai)(cai)(cai)料(liao)無(wu)須(xu)比(bi)工(gong)(gong)(gong)(gong)(gong)(gong)件(jian)材(cai)(cai)(cai)料(liao)硬(ying)；直接使用(yong)(yong)(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)能(neng)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)，便于實現自動(dong)(dong)化(hua)(hua)；加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)后(hou)(hou)表(biao)(biao)面(mian)產生(sheng)(sheng)(sheng)變質(zhi)層(ceng)，在某些應用(yong)(yong)(yong)(yong)中(zhong)(zhong)須(xu)進一步去除；工(gong)(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)液的(de)(de)(de)(de)凈化(hua)(hua)和加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)中(zhong)(zhong)產生(sheng)(sheng)(sheng)的(de)(de)(de)(de)煙霧污(wu)染處理比(bi)較麻煩(fan)。