臥式加工(gong)(gong)中(zhong)(zhong)心在(zai)加工(gong)(gong)零(ling)(ling)件(jian)時(shi)(shi)，由于零(ling)(ling)件(jian)加工(gong)(gong)部位(wei)的(de)(de)(de)需要(yao)(yao)，通常要(yao)(yao)求工(gong)(gong)作(zuo)臺旋轉(zhuan)(zhuan)任意角度(du)。當工(gong)(gong)件(jian)坐(zuo)標(biao)系(xi)原點(dian)與工(gong)(gong)作(zuo)臺旋轉(zhuan)(zhuan)中(zhong)(zhong)心重(zhong)(zhong)合時(shi)(shi)，工(gong)(gong)作(zuo)臺的(de)(de)(de)旋轉(zhuan)(zhuan)不會(hui)給加工(gong)(gong)帶來影響。但是由于工(gong)(gong)件(jian)坐(zuo)標(biao)系(xi)原點(dian)的(de)(de)(de)選擇是根據零(ling)(ling)件(jian)結(jie)構特點(dian)、編程的(de)(de)(de)需要(yao)(yao)而確定的(de)(de)(de)，通常被加工(gong)(gong)零(ling)(ling)件(jian)無法與工(gong)(gong)作(zuo)臺的(de)(de)(de)旋轉(zhuan)(zhuan)中(zhong)(zhong)心重(zhong)(zhong)合，工(gong)(gong)件(jian)坐(zuo)標(biao)系(xi)原點(dian)的(de)(de)(de)位(wei)置隨(sui)著工(gong)(gong)作(zuo)臺的(de)(de)(de)旋轉(zhuan)(zhuan)，在(zai)機床坐(zuo)標(biao)系(xi)中(zhong)(zhong)發生(sheng)變化(hua)。因此，要(yao)(yao)重(zhong)(zhong)新(xin)設定工(gong)(gong)件(jian)坐(zuo)標(biao)系(xi)原點(dian)。每一臺臥式加工(gong)(gong)中(zhong)(zhong)心z軸(zhou)(zhou)主(zhu)軸(zhou)(zhou)端(duan)面(mian)(mian)與B軸(zhou)(zhou)回(hui)轉(zhuan)(zhuan)中(zhong)(zhong)心有個固(gu)定值(zhi)，因為臥加B軸(zhou)(zhou)旋轉(zhuan)(zhuan)時(shi)(shi)候(hou)，用宏程序(xu)換算坐(zuo)標(biao)系(xi)時(shi)(shi)候(hou)需要(yao)(yao)用到(dao)這(zhe)個值(zhi)，下面(mian)(mian)是我公司研究得出(chu)的(de)(de)(de)一個簡單(dan)可行的(de)(de)(de)辦(ban)法。
一個面的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點設定(ding)好之后，根據補償(chang)值(zhi)，人工(gong)計(ji)算其他面的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點并(bing)(bing)輸(shu)入到相應的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)中(zhong)，容易(yi)出錯，且只能計(ji)算工(gong)作臺(tai)旋(xuan)轉(zhuan)90度(du)(du)、180度(du)(du)、270度(du)(du)位置的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點，不能計(ji)算任意旋(xuan)轉(zhuan)角(jiao)度(du)(du)的(de)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點。該程序可根據初始工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點設定(ding)值(zhi)，實(shi)現工(gong)作臺(tai)旋(xuan)轉(zhuan)任意角(jiao)度(du)(du)的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點自動補償(chang)計(ji)算，并(bing)(bing)設定(ding)新的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)原(yuan)點，自動輸(shu)入到相應的(de)工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)中(zhong)，減(jian)少了工(gong)件(jian)坐(zuo)標(biao)(biao)(biao)系(xi)設定(ding)時(shi)間(jian)和出錯的(de)概率，提(ti)高(gao)了生產效率和準(zhun)確性。
測量原理：
找出工(gong)作(zuo)臺回轉中(zhong)心到(dao)Z向(xiang)機床原(yuan)點(dian)的距離Z0即為Z向(xiang)工(gong)作(zuo)臺回轉中(zhong)心的位置(zhi)。工(gong)作(zuo)臺回轉中(zhong)心的位置(zhi)如圖1c所示。
測量方法：如圖(tu)4所示，當工(gong)作臺(tai)分別在0度和180度時，移(yi)動工(gong)作臺(tai)以調整Z向坐標，使百分表(biao)的讀數相同，則：
Z向回轉中心=CRT顯示的Z向坐標值
Z向回(hui)轉中心的(de)準確性，影響機床調(diao)頭(tou)加(jia)工工件時(shi)兩端(duan)面之間的(de)距(ju)離尺寸精度（在刀具(ju)長(chang)度測量(liang)準確的(de)前提(ti)下(xia)）。反之，它也可修正刀具(ju)長(chang)度測量(liang)偏差。
臥(wo)式加工(gong)(gong)中(zhong)(zhong)心(xin)(xin)機(ji)床(chuang)回(hui)轉中(zhong)(zhong)心(xin)(xin)在(zai)(zai)一次測(ce)量(liang)得出準確值以(yi)后，可以(yi)在(zai)(zai)一段時間(jian)內(nei)作為基準。但是(shi)，隨(sui)著機(ji)床(chuang)的使用，特別是(shi)在(zai)(zai)機(ji)床(chuang)相(xiang)關部(bu)分(fen)出現(xian)機(ji)械故障時，都有可能使機(ji)床(chuang)回(hui)轉中(zhong)(zhong)心(xin)(xin)出現(xian)變(bian)化(hua)。例如(ru)，機(ji)床(chuang)在(zai)(zai)加工(gong)(gong)過程中(zhong)(zhong)出現(xian)撞車(che)事(shi)故、機(ji)床(chuang)絲杠螺母松動時等。因此(ci)，機(ji)床(chuang)回(hui)轉中(zhong)(zhong)心(xin)(xin)必須定期測(ce)量(liang)，特別是(shi)在(zai)(zai)加工(gong)(gong)相(xiang)對精(jing)(jing)度(du)(du)較高的工(gong)(gong)件之前(qian)應(ying)重(zhong)新測(ce)量(liang)，以(yi)校對機(ji)床(chuang)回(hui)轉中(zhong)(zhong)心(xin)(xin)，從而保證工(gong)(gong)件加工(gong)(gong)的精(jing)(jing)度(du)(du)。
