CNC加工是利用(yong)自(zi)動(dong)控制系(xi)統安(an)裝數(shu)字程序流(liu)程命令，控制數(shu)控機床軸承(cheng)的(de)自(zi)動(dong)啟停(ting)、換向(xiang)和變速。可以挑選(xuan)數(shu)控刀片，改變數(shu)控刀片的(de)鉆削量和走動(dong)運動(dong)軌跡，進行終生加(jia)工需要的(de)各種(zhong)各樣(yang)輔(fu)助姿勢。

CNC加工可以降低工作量，生產制造出加工方法復雜的零件，只需要改變工藝流程。CNC加工相對平穩，不會造成加工誤差。影響CNC加工的精度的原因(yin)有哪(na)些？

一、CNC加工機床定位引起的加工精度誤差(cha)

從零件加(jia)工的長期數(shu)據分析和實際操作中可(ke)以看出CNC加(jia)工機(ji)床(chuang)定位引(yin)起的加(jia)工精(jing)(jing)度誤差(cha)。機(ji)床(chuang)的定位對數(shu)控(kong)機(ji)床(chuang)的加(jia)工精(jing)(jing)度有很大影響。從構造上看，數(shu)控(kong)機(ji)床(chuang)的加(jia)工誤差(cha)主要是(shi)由精(jing)(jing)度等級引(yin)起的，機(ji)床(chuang)進給(gei)系統是(shi)影響精(jing)(jing)度等級的關(guan)鍵階段。

數控(kong)機(ji)床的進給(gei)系(xi)(xi)(xi)統一般(ban)由機(ji)械傳(chuan)動系(xi)(xi)(xi)統和電氣控(kong)制系(xi)(xi)(xi)統構(gou)成。在總(zong)體設(she)計中(zhong)，精(jing)度等(deng)級與機(ji)械傳(chuan)動系(xi)(xi)(xi)統相關。在閉(bi)環控(kong)制系(xi)(xi)(xi)統中(zhong)，數控(kong)機(ji)床一般(ban)可(ke)以(yi)根據定(ding)位(wei)檢驗設(she)備來(lai)避免進給(gei)系(xi)(xi)(xi)統中(zhong)關鍵(jian)構(gou)件(jian)(如滾珠絲桿和別(bie)的構(gou)件(jian))的位(wei)置(zhi)誤差。對于開環系(xi)(xi)(xi)統，因(yin)(yin)為影響(xiang)因(yin)(yin)素多、條件(jian)復(fu)雜，沒法(fa)開展定(ding)位(wei)檢測，因(yin)(yin)而數控(kong)機(ji)床的加工精(jing)度遭受(shou)很大影響(xiang)。

 二、CNC加(jia)工(gong)位置誤差對(dui)加(jia)工(gong)精度的影(ying)響

位(wei)(wei)(wei)(wei)置(zhi)(zhi)誤(wu)(wu)差(cha)(cha)是(shi)指被加工(gong)零件的(de)具(ju)(ju)體表層、中(zhong)(zhong)心線或對(dui)稱(cheng)性臉相對(dui)于其理想化位(wei)(wei)(wei)(wei)置(zhi)(zhi)的(de)互(hu)相位(wei)(wei)(wei)(wei)置(zhi)(zhi)的(de)轉變或偏(pian)移水平，如平整度、對(dui)稱(cheng)度、對(dui)稱(cheng)度等(deng)。數控機床(chuang)(chuang)加工(gong)中(zhong)(zhong)的(de)位(wei)(wei)(wei)(wei)置(zhi)(zhi)誤(wu)(wu)差(cha)(cha)一般(ban)指過(guo)流保(bao)護(hu)誤(wu)(wu)差(cha)(cha)。造(zao)成位(wei)(wei)(wei)(wei)置(zhi)(zhi)誤(wu)(wu)差(cha)(cha)的(de)關(guan)鍵緣故是(shi)機床(chuang)(chuang)零件加工(gong)全(quan)過(guo)程中(zhong)(zhong)傳動(dong)系統造(zao)成的(de)空隙和彈性變形(xing)引起(qi)的(de)加工(gong)誤(wu)(wu)差(cha)(cha)，及其生產過(guo)程中(zhong)(zhong)專用(yong)工(gong)具(ju)(ju)頭需要擺脫的(de)滑動(dong)摩擦力等(deng)要素引起(qi)的(de)位(wei)(wei)(wei)(wei)置(zhi)(zhi)誤(wu)(wu)差(cha)(cha)。在(zai)(zai)開環(huan)(huan)系統中(zhong)(zhong)，位(wei)(wei)(wei)(wei)置(zhi)(zhi)精密度遭受很大影(ying)響，而(er)在(zai)(zai)閉環(huan)(huan)控制轉向頭燈系統中(zhong)(zhong)，位(wei)(wei)(wei)(wei)置(zhi)(zhi)精密度關(guan)鍵在(zai)(zai)于偏(pian)移檢驗(yan)。

三、CNC加工的幾何圖形誤(wu)差引(yin)起的加工精(jing)度誤(wu)差

在數控機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)的(de)(de)加工(gong)(gong)中，因(yin)為(wei)外(wai)力作用、加工(gong)(gong)中造(zao)(zao)(zao)成的(de)(de)發熱(re)量等(deng)外(wai)界要(yao)(yao)素(su)(su)的(de)(de)影(ying)響，機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)的(de)(de)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)精(jing)(jing)密(mi)度(du)(du)遭受(shou)影(ying)響，在機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)上加工(gong)(gong)的(de)(de)零(ling)件的(de)(de)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)形(xing)(xing)(xing)(xing)(xing)變(bian)會(hui)(hui)造(zao)(zao)(zao)成幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)誤差(cha)。據(ju)科學(xue)研究，數控機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)誤差(cha)關鍵有兩個緣故：內部(bu)要(yao)(yao)素(su)(su)和(he)外(wai)界要(yao)(yao)素(su)(su)。引(yin)起機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)誤差(cha)的(de)(de)內部(bu)要(yao)(yao)素(su)(su)是指由機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)本身要(yao)(yao)素(su)(su)引(yin)起的(de)(de)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)誤差(cha)，如(ru)機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)工(gong)(gong)作臺的(de)(de)平整度(du)(du)、機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)導軌的(de)(de)平整度(du)(du)和(he)平行度(du)(du)、機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)專用工(gong)(gong)具和(he)工(gong)(gong)裝夾具的(de)(de)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)精(jing)(jing)密(mi)度(du)(du)等(deng)。外(wai)界要(yao)(yao)素(su)(su)關鍵指生產過(guo)程中受(shou)環(huan)境因(yin)素(su)(su)和(he)熱(re)形(xing)(xing)(xing)(xing)(xing)變(bian)影(ying)響而造(zao)(zao)(zao)成的(de)(de)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)誤差(cha)。比如(ru)，鉆削全過(guo)程中數控刀(dao)片或零(ling)件的(de)(de)熱(re)變(bian)形(xing)(xing)(xing)(xing)(xing)和(he)形(xing)(xing)(xing)(xing)(xing)變(bian)造(zao)(zao)(zao)成的(de)(de)幾(ji)(ji)(ji)(ji)何(he)圖形(xing)(xing)(xing)(xing)(xing)誤差(cha)會(hui)(hui)影(ying)響機(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)(chuang)和(he)零(ling)件的(de)(de)加工(gong)(gong)精(jing)(jing)度(du)(du)。