1,鉬(mu)絲(si)鉬(mu)絲(si)的松緊程度

如果鉬絲(si)(si)(si)安裝太(tai)(tai)松，則鉬絲(si)(si)(si)抖動(dong)厲害 ，不僅會造成(cheng)斷(duan)(duan)絲(si)(si)(si)，而且(qie)由(you)(you)于(yu)鉬絲(si)(si)(si)的(de)(de)抖動(dong)直接影響工(gong)(gong)件(jian)表面粗(cu)糙度(du)。但(dan)鉬絲(si)(si)(si)也不能安裝 得太(tai)(tai)緊(jin)(jin)，太(tai)(tai)緊(jin)(jin)內應力增(zeng)大(da)，也會造成(cheng)斷(duan)(duan)絲(si)(si)(si)，因此(ci)鉬絲(si)(si)(si)在切割過程中，其松緊(jin)(jin)程度(du)要(yao)適(shi)當(dang)(dang) ，新(xin)安裝的(de)(de)鉬絲(si)(si)(si)，要(yao)先緊(jin)(jin)絲(si)(si)(si)再(zai)加工(gong)(gong)，緊(jin)(jin)絲(si)(si)(si)時(shi)(shi)用力不要(yao)太(tai)(tai)大(da)。鉬絲(si)(si)(si)在加工(gong)(gong)一段時(shi)(shi)間后，由(you)(you) 于(yu)自身(shen)的(de)(de)拉伸(shen)而變松。當(dang)(dang)伸(shen)長量較大(da)時(shi)(shi)，會加劇鉬絲(si)(si)(si)振(zhen)動(dong)或出(chu)現鉬絲(si)(si)(si)在貯絲(si)(si)(si)筒(tong)上重(zhong)疊(die)。 使走絲(si)(si)(si)不穩而引起(qi)斷(duan)(duan)絲(si)(si)(si)。應經常檢(jian)查鉬絲(si)(si)(si)的(de)(de)松緊(jin)(jin)程度(du)，如果存在松弛現象，要(yao)及時(shi)(shi)拉緊(jin)(jin) 。

鉬(mu)絲(si)(si)(si)安裝。鉬(mu)絲(si)(si)(si)要按規定的走向(xiang)繞(rao)在貯絲(si)(si)(si)筒(tong)上，同(tong)時固(gu)定兩(liang)端。繞(rao)絲(si)(si)(si)時，一般貯絲(si)(si)(si) 筒(tong)兩(liang)端各(ge)留10mm，中間繞(rao)滿(man)不重疊，寬度(du)不少于(yu)貯絲(si)(si)(si)筒(tong)長度(du)的一半，以(yi)免電機(ji)換向(xiang)頻(pin)繁 而(er)使(shi)機(ji)件加速損壞，也防止鉬(mu)絲(si)(si)(si)頻(pin)繁參與(yu)切(qie)割而(er)斷絲(si)(si)(si)。

機(ji)床上鉬(mu)絲(si)(si)引出處有擋(dang)絲(si)(si)棒(bang)，擋(dang)絲(si)(si)棒(bang)是由兩根紅寶石制(zhi)成(cheng)的導(dao)向立柱，擋(dang)絲(si)(si)棒(bang)不像 導(dao)輪那樣(yang)作(zuo)滾動運動，他們直接(jie)(jie)(jie)與(yu)鉬(mu)絲(si)(si)接(jie)(jie)(jie)觸，作(zuo)滑(hua)動摩擦。因(yin)此磨損很快(kuai)，使用(yong)不久(jiu)柱 體與(yu)鉬(mu)絲(si)(si)接(jie)(jie)(jie)觸的地方就會形成(cheng)深(shen)溝，必須及時檢查并進行翻轉和更換，否則會出現疊絲(si)(si) 斷絲(si)(si)。

2,運絲機構

中(zhong)走絲(si)(si)(si)線切割機(ji)(ji)的(de)(de)(de)(de)(de)運(yun)絲(si)(si)(si)機(ji)(ji)構主(zhu)要(yao)是(shi)由貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)、線架和(he)導輪(lun)(lun)組(zu)成。當運(yun)絲(si)(si)(si)機(ji)(ji)構的(de)(de)(de)(de)(de)精度(du)(du)下降(jiang)時 （主(zhu)要(yao)是(shi)傳動(dong)(dong)(dong)(dong)軸(zhou)承），會(hui)(hui)引(yin)(yin)起貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)徑向跳動(dong)(dong)(dong)(dong)和(he)軸(zhou)向竄(cuan)(cuan)動(dong)(dong)(dong)(dong)。貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)徑向跳動(dong)(dong)(dong)(dong)會(hui)(hui)使(shi)(shi)(shi)電(dian)(dian)(dian) 極絲(si)(si)(si)的(de)(de)(de)(de)(de)張力減(jian)小，造成絲(si)(si)(si)松，嚴重(zhong)時會(hui)(hui)使(shi)(shi)(shi)鉬(mu)(mu)(mu)絲(si)(si)(si)從導輪(lun)(lun)槽(cao)中(zhong)脫出拉(la)斷(duan)。貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)軸(zhou)向竄(cuan)(cuan)動(dong)(dong)(dong)(dong) 會(hui)(hui)使(shi)(shi)(shi)排絲(si)(si)(si)不勻(yun)，產(chan)生(sheng)(sheng)疊(die)絲(si)(si)(si)現(xian)象。貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)軸(zhou)和(he)軸(zhou)承等零(ling)(ling)件常(chang)因(yin)(yin)磨損(sun)(sun)而(er)產(chan)生(sheng)(sheng)間(jian)隙(xi)，也(ye)(ye)容易(yi)(yi)(yi)(yi) 引(yin)(yin)起絲(si)(si)(si)抖(dou)(dou)動(dong)(dong)(dong)(dong)而(er)斷(duan)絲(si)(si)(si)，因(yin)(yin)此必須及時更(geng)(geng)換(huan)磨損(sun)(sun)的(de)(de)(de)(de)(de)軸(zhou)和(he)軸(zhou)承等零(ling)(ling)件。貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)換(huan)向時，如沒(mei)有 切斷(duan)高頻電(dian)(dian)(dian)源(yuan)，會(hui)(hui)導致鉬(mu)(mu)(mu)絲(si)(si)(si)在(zai)(zai)(zai)短時間(jian)內溫(wen)度(du)(du)過高而(er)燒斷(duan)鉬(mu)(mu)(mu)絲(si)(si)(si)，因(yin)(yin)此必須檢(jian)查(cha)貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)后(hou)端(duan) 的(de)(de)(de)(de)(de)行程(cheng)開關是(shi)否(fou)失靈(ling)。要(yao)保(bao)持貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)、導輪(lun)(lun)轉(zhuan)動(dong)(dong)(dong)(dong)靈(ling)活，否(fou)則在(zai)(zai)(zai)往返運(yun)動(dong)(dong)(dong)(dong)時會(hui)(hui)引(yin)(yin)起運(yun)絲(si)(si)(si)系 統振動(dong)(dong)(dong)(dong)而(er)斷(duan)絲(si)(si)(si)。繞(rao)絲(si)(si)(si)后(hou)空載走絲(si)(si)(si)檢(jian)驗鉬(mu)(mu)(mu)絲(si)(si)(si)是(shi)否(fou)抖(dou)(dou)動(dong)(dong)(dong)(dong)，若發生(sheng)(sheng)抖(dou)(dou)動(dong)(dong)(dong)(dong)要(yao)分析原因(yin)(yin)。貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)后(hou) 端(duan)的(de)(de)(de)(de)(de)限位擋(dang)塊(kuai)必須調整好，避(bi)免(mian)貯(zhu)(zhu)絲(si)(si)(si)筒(tong)(tong)(tong)(tong)(tong)沖出限位行程(cheng)而(er)斷(duan)絲(si)(si)(si)。擋(dang)絲(si)(si)(si)裝置中(zhong)擋(dang)塊(kuai)與(yu)快速運(yun) 動(dong)(dong)(dong)(dong)的(de)(de)(de)(de)(de)鉬(mu)(mu)(mu)絲(si)(si)(si)接觸、摩(mo)擦，易(yi)(yi)(yi)(yi)產(chan)生(sheng)(sheng)溝(gou)槽(cao)并造成夾絲(si)(si)(si)拉(la)斷(duan)，因(yin)(yin)此也(ye)(ye)需及時更(geng)(geng)換(huan)。導輪(lun)(lun)軸(zhou)承的(de)(de)(de)(de)(de)磨 損(sun)(sun)將(jiang)直接影響導絲(si)(si)(si)精度(du)(du)，此外，當導輪(lun)(lun)的(de)(de)(de)(de)(de)v型(xing)槽(cao)、寶石限位塊(kuai)、導電(dian)(dian)(dian)塊(kuai)磨損(sun)(sun)后(hou)產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)溝(gou)槽(cao) ，也(ye)(ye)會(hui)(hui)使(shi)(shi)(shi)電(dian)(dian)(dian)極絲(si)(si)(si)的(de)(de)(de)(de)(de)摩(mo)擦力過大，易(yi)(yi)(yi)(yi)將(jiang)鉬(mu)(mu)(mu)絲(si)(si)(si)拉(la)斷(duan)。這(zhe)種(zhong)現(xian)象一(yi)般(ban)發生(sheng)(sheng)在(zai)(zai)(zai)機(ji)(ji)床使(shi)(shi)(shi)用時間(jian)較(jiao)長 、加工工件較(jiao)厚、運(yun)絲(si)(si)(si)機(ji)(ji)構不易(yi)(yi)(yi)(yi)清理的(de)(de)(de)(de)(de)情況下。因(yin)(yin)此在(zai)(zai)(zai)機(ji)(ji)床使(shi)(shi)(shi)用中(zhong)應定期檢(jian)查(cha)運(yun)絲(si)(si)(si)機(ji)(ji)構 的(de)(de)(de)(de)(de)精度(du)(du)，及時更(geng)(geng)換(huan)易(yi)(yi)(yi)(yi)磨損(sun)(sun)件。

3,工件

工(gong)件(jian)材(cai)料(liao)(liao)：對不經鍛打、不淬火材(cai)料(liao)(liao)，在線切割(ge)(ge)(ge)加工(gong)前采用低溫回(hui)火消(xiao)除內(nei)應 力(li)，因為如果(guo)工(gong)件(jian)的(de)(de)內(nei)應力(li)沒有得到(dao)消(xiao)除，在切割(ge)(ge)(ge)時(shi)，有的(de)(de)工(gong)件(jian)會開裂，把(ba)鉬絲(si)碰斷； 有的(de)(de)會使間隙變形，把(ba)鉬絲(si)夾斷或彈(dan)斷。如淬火后t8鋼在線切割(ge)(ge)(ge)加工(gong)中及易引(yin)起斷絲(si)盡 量少用。切割(ge)(ge)(ge)厚鋁材(cai)料(liao)(liao)時(shi)，由于排屑困難(nan)，導電塊(kuai)磨損較(jiao)大(da)，注意(yi)及時(shi)更換(huan)。

工(gong)(gong)件(jian)裝夾：雖然(ran)線切割加工(gong)(gong)過程中(zhong)(zhong)工(gong)(gong)件(jian)受力極小(xiao)，但仍需牢固夾緊工(gong)(gong)件(jian)，防(fang)止加工(gong)(gong) 過程中(zhong)(zhong)因工(gong)(gong)件(jian)位(wei)置(zhi)變(bian)動造(zao)(zao)成(cheng)斷(duan)(duan)絲(si)(si)。同時(shi)要(yao)避免由于工(gong)(gong)件(jian)的(de)(de)(de)自重和工(gong)(gong)件(jian)材料的(de)(de)(de)彈性變(bian)形造(zao)(zao) 成(cheng)的(de)(de)(de)斷(duan)(duan)絲(si)(si)。在(zai)加工(gong)(gong)厚重工(gong)(gong)件(jian)時(shi)，可在(zai)加工(gong)(gong)快要(yao)結束時(shi)，用磁(ci)鐵吸(xi)住將(jiang)(jiang)要(yao)下落(luo)(luo)的(de)(de)(de)工(gong)(gong)件(jian)，或 者(zhe)人工(gong)(gong)保護(hu)下落(luo)(luo)的(de)(de)(de)工(gong)(gong)件(jian)，使其平行緩慢下落(luo)(luo)從而防(fang)止斷(duan)(duan)絲(si)(si)。 4電(dian)(dian)(dian)(dian)(dian)參(can)數電(dian)(dian)(dian)(dian)(dian)參(can)數選(xuan)擇(ze)不當也(ye) 是引起(qi)(qi)(qi)斷(duan)(duan)絲(si)(si)的(de)(de)(de)一個(ge)重要(yao)原因，所以要(yao)根據工(gong)(gong)件(jian)厚度選(xuan)擇(ze)合(he)理(li)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)參(can)數，將(jiang)(jiang)脈沖(chong)間隔(ge)拉(la)開 一些，有利于熔(rong)化金(jin)屬微(wei)粒的(de)(de)(de)排出，同時(shi)峰值(zhi)電(dian)(dian)(dian)(dian)(dian)流(liu)和空(kong)載(zai)電(dian)(dian)(dian)(dian)(dian)壓不宜過高(gao)，否則使單個(ge)脈 沖(chong)能量變(bian)大，切割速度加快，容易產生集中(zhong)(zhong)放電(dian)(dian)(dian)(dian)(dian)和拉(la)弧(hu)，引起(qi)(qi)(qi)斷(duan)(duan)絲(si)(si)。一般空(kong)載(zai)電(dian)(dian)(dian)(dian)(dian)壓為 100v左右(you)。在(zai)電(dian)(dian)(dian)(dian)(dian)火花(hua)加工(gong)(gong)中(zhong)(zhong)，電(dian)(dian)(dian)(dian)(dian)弧(hu)放電(dian)(dian)(dian)(dian)(dian)是造(zao)(zao)成(cheng)負極腐蝕損壞的(de)(de)(de)主要(yao)因素，再加上間隙不 合(he)適，容易使某一脈沖(chong)形成(cheng)電(dian)(dian)(dian)(dian)(dian)弧(hu)放電(dian)(dian)(dian)(dian)(dian)，只要(yao)電(dian)(dian)(dian)(dian)(dian)弧(hu)放電(dian)(dian)(dian)(dian)(dian)集中(zhong)(zhong)于某一段，就會引起(qi)(qi)(qi)斷(duan)(duan)絲(si)(si)。