模(mo)具加工：方(fang)法是(shi)多種多樣的,下面(mian)(mian)我們(men)來(lai)分析(xi)一(yi)下有關電(dian)(dian)火花成形加工(gong)方(fang)法知識。電(dian)(dian)火花成形加工(gong)主要(yao)是(shi)利用在工(gong)具和工(gong)件(jian)(正、負電(dian)(dian)極)之間產生(sheng)脈沖性火花放電(dian)(dian)時的電(dian)(dian)腐(fu)蝕現(xian)象來(lai)蝕除(chu)多余的金(jin)屬,以(yi)達(da)到零件(jian)技術(shu)要(yao)求(qiu)所規定的尺寸、形狀及表(biao)面(mian)(mian)質量。

1、模具電火花成形加工(gong)方法必(bi)須滿足三大條(tiao)件:

①必須使(shi)工(gong)(gong)具電(dian)極(ji)和(he)工(gong)(gong)件被加工(gong)(gong)表面之(zhi)間(jian)保(bao)持一定的間(jian)隙(xi),因此在電(dian)火花加工(gong)(gong)中必須具有工(gong)(gong)具電(dian)極(ji)的自動進(jin)給和(he)調節裝置;

②火花放(fang)電(dian)(dian)(dian)必(bi)須是(shi)瞬(shun)時的脈沖(chong)性放(fang)電(dian)(dian)(dian),為此(ci)電(dian)(dian)(dian)火花加(jia)工必(bi)須使用(yong)脈沖(chong)電(dian)(dian)(dian)源;

③火花放(fang)電(dian)必(bi)須在有一定絕緣性能的液體(ti)介質中進行。

2、影響(xiang)電火花成形(xing)蝕除速率的因(yin)素:電規準、極性效應、金屬材料的熱(re)學常數、工(gong)作液、排屑(xie)條件。

3、影響電火花成形加(jia)工(gong)精(jing)度的(de)因(yin)素(su):機床(chuang)本身的(de)各種(zhong)誤(wu)差(cha)、工(gong)具電極制造精(jing)度、工(gong)件和(he)電極的(de)定位及安裝(zhuang)誤(wu)差(cha)、放電間隙的(de)大(da)小(xiao)和(he)一致性(xing)、工(gong)件電極的(de)損耗及其加(jia)工(gong)穩定性(xing)。

4、電(dian)火花加(jia)工的電(dian)極材料要(yao)求:損耗小、加(jia)工過(guo)程穩定、生(sheng)產率高(gao)、機械(xie)加(jia)工性能好(hao)、價格低廉(lian)。常用材料:紫銅(tong)、石墨、鑄鐵、鋼、黃銅(tong)、同鎢合金(jin)、銀鎢合金(jin)。

結構形(xing)式:①整體(ti)式電極(ji)②鑲拼式電極③組合電極。

5、電火花成形加工型(xing)腔模的方法:

①單(dan)電極平動法②多電極更換法③分(fen)解電(dian)極法。