? ? 改造要點

1．滾珠(zhu)絲(si)杠副改造(zao)。為了(le)實現絲(si)杠無隙傳(chuan)動，車床(chuang)數控(kong)改造(zao)，應將原機床(chuang)的(de)滑動絲(si)杠改換成滾珠(zhu)絲(si)杠副。此項不(bu)屬(shu)必改項，車床(chuang)數控(kong)改造(zao)聯系電話，如(ru)對機床(chuang)精度(du)要求不(bu)高時，可以通過預緊原螺母的(de)方(fang)法(fa)消除傳(chuan)動間隙。

2．步進(jin)電(dian)(dian)機選用。車床(chuang)進(jin)給傳(chuan)動(dong)(dong)(dong)部分改造時要拆除機械(xie)傳(chuan)動(dong)(dong)(dong)機構，代(dai)之(zhi)以步進(jin)電(dian)(dian)機經(jing)齒(chi)輪或同步帶、減速(su)驅(qu)動(dong)(dong)(dong)絲杠，帶動(dong)(dong)(dong)刀(dao)架(jia)移動(dong)(dong)(dong)。縱向(xiang)步進(jin)電(dian)(dian)機固定在(zai)床(chuang)身上，橫向(xiang)步進(jin)電(dian)(dian)機固定在(zai)床(chuang)鞍上。如(ru)步進(jin)電(dian)(dian)機的轉矩足夠大及結構許可的情況下，也可以不用減速(su)驅(qu)動(dong)(dong)(dong)機構，由(you)步進(jin)電(dian)(dian)機直(zhi)接與滾動(dong)(dong)(dong)絲杠相連。

機(ji)床(chuang)參考點(dian)(基準點(dian))

機(ji)床(chuang)(chuang)(chuang)參(can)考(kao)(kao)(kao)點( R) 是由機(ji)床(chuang)(chuang)(chuang)制(zhi)造廠家人為定義的點，機(ji)床(chuang)(chuang)(chuang)參(can)考(kao)(kao)(kao)點( R) 與(yu)機(ji)床(chuang)(chuang)(chuang)零點( M) 之間的坐標(biao)位(wei)置關(guan)系(xi)是固定的并(bing)被存放(fang)在(zai)數(shu)(shu)(shu)控(kong)系(xi)統(tong)的相(xiang)應機(ji)床(chuang)(chuang)(chuang)數(shu)(shu)(shu)據中，一般(ban)是不允許改變的。僅在(zai)特殊情況下可(ke)通過(guo)變動(dong)(dong)機(ji)床(chuang)(chuang)(chuang)參(can)考(kao)(kao)(kao)點( R) 的限位(wei)開關(guan)位(wei)置來變動(dong)(dong)其位(wei)置； 但同時必須能(neng)準(zhun)確測量出機(ji)床(chuang)(chuang)(chuang)參(can)考(kao)(kao)(kao)點( R) 相(xiang)對機(ji)床(chuang)(chuang)(chuang)零點( M) 的幾(ji)何尺(chi)寸距離并(bing)存入數(shu)(shu)(shu)控(kong)系(xi)統(tong)的相(xiang)應機(ji)床(chuang)(chuang)(chuang)數(shu)(shu)(shu)據中，才能(neng)保證原設計的機(ji)床(chuang)(chuang)(chuang)坐標(biao)系(xi)統(tong)不被破壞。控(kong)制(zhi)系(xi)統(tong)啟動(dong)(dong)后，所有的軸都要(yao)回(hui)一次(ci)參(can)考(kao)(kao)(kao)點，以(yi)便校正行程測量系(xi)統(tong)。多數(shu)(shu)(shu)機(ji)床(chuang)(chuang)(chuang)都可(ke)以(yi)自動(dong)(dong)返(fan)回(hui)參(can)考(kao)(kao)(kao)點，如因斷(duan)電使(shi)控(kong)制(zhi)系(xi)統(tong)失去現有坐標(biao)值， 則可(ke)返(fan)回(hui)參(can)考(kao)(kao)(kao)點，并(bing)重新(xin)獲得準(zhun)確的位(wei)置值。

? ? 異步電(dian)機或直流電(dian)機拖動光柵測量(liang)反饋的閉環數控(kong)系統(tong)介紹(shao)

異步電(dian)(dian)(dian)(dian)機(ji)或直(zhi)流電(dian)(dian)(dian)(dian)機(ji)拖(tuo)動光柵(zha)(zha)測量(liang)反(fan)饋的(de)閉(bi)環(huan)數(shu)控(kong)(kong)系(xi)(xi)統(tong)(tong)控(kong)(kong)制(zhi)精(jing)度(du)高(gao)，但在(zai)結構(gou)(gou)上比開環(huan)進給系(xi)(xi)統(tong)(tong)復雜，工作量(liang)大，車(che)床數(shu)控(kong)(kong)改造(zao)價(jia)格，成本也高(gao)，調試(shi)困難，一般不采用。交／直(zhi)流伺服電(dian)(dian)(dian)(dian)機(ji)拖(tuo)動編(bian)碼(ma)器反(fan)饋的(de)半閉(bi)環(huan)數(shu)控(kong)(kong)系(xi)(xi)統(tong)(tong)，其精(jing)度(du)介于(yu)步進電(dian)(dian)(dian)(dian)機(ji)拖(tuo)動的(de)開環(huan)系(xi)(xi)統(tong)(tong)和(he)異步電(dian)(dian)(dian)(dian)機(ji)或直(zhi)流電(dian)(dian)(dian)(dian)機(ji)拖(tuo)動光柵(zha)(zha)測量(liang)反(fan)饋的(de)閉(bi)環(huan)數(shu)控(kong)(kong)系(xi)(xi)統(tong)(tong)之(zhi)間，結構(gou)(gou)與(yu)調試(shi)都較(jiao)閉(bi)環(huan)系(xi)(xi)統(tong)(tong)簡(jian)單，適用于(yu)控(kong)(kong)制(zhi)精(jing)度(du)要求(qiu)較(jiao)高(gao)的(de)大、中(zhong)型機(ji)床的(de)改造(zao)。