隨著現代制造技術的(de)發(fa)展，企業選用(yong)數控(kong)設備已(yi)是(shi)大勢所趨。目前市面(mian)上的(de)數控(kong)設備可謂(wei)琳瑯滿目，如何才能既經(jing)濟又合理地(di)選擇到適合本企業的(de)數控(kong)設備，一直是(shi)人(ren)們關注的(de)話題。本文(wen)完(wan)全從技術的(de)角(jiao)度對選型中(zhong)應注意的(de)問題進(jin)行了全面(mian)的(de)論述。

　　對一個(ge)制(zhi)造(zao)企業來(lai)說，提高生(sheng)(sheng)產(chan)(chan)能力往(wang)往(wang)從生(sheng)(sheng)產(chan)(chan)管(guan)理、制(zhi)造(zao)工藝、生(sheng)(sheng)產(chan)(chan)設備等方(fang)面入手進行技(ji)術改造(zao)，而(er)這幾部分內(nei)容又是(shi)互為影響和制(zhi)約的(de)。在技(ji)改中(zhong)對生(sheng)(sheng)產(chan)(chan)設備、數控機床的(de)更新、維修、采購等的(de)選擇上必須考慮到要在什(shen)么樣(yang)環(huan)境下使用、如何管(guan)理、怎樣(yang)能達(da)到最(zui)好(hao)的(de)經濟效果(guo)等問(wen)題(ti)。

　　選擇制(zhi)(zhi)造設(she)備(bei)是要為制(zhi)(zhi)造某一些產(chan)(chan)(chan)品(pin)服(fu)務(wu)的(de)，選擇的(de)設(she)備(bei)可(ke)能(neng)用(yong)于產(chan)(chan)(chan)品(pin)零件的(de)一部(bu)分工序加(jia)工、也(ye)可(ke)能(neng)用(yong)于全(quan)部(bu)工序加(jia)工。制(zhi)(zhi)造水(shui)(shui)平(ping)的(de)高低(di)首先取(qu)決于工藝過程的(de)設(she)計，它將決定用(yong)什么方法和(he)手段來(lai)加(jia)工，從而也(ye)決定了對使用(yong)設(she)備(bei)的(de)基本要求，這也(ye)是對生(sheng)產(chan)(chan)(chan)進行技(ji)(ji)術(shu)組(zu)織和(he)管(guan)理的(de)依據。設(she)備(bei)選擇的(de)基本要求確定后(hou)還要根據市場上能(neng)提供什么樣技(ji)(ji)術(shu)水(shui)(shui)平(ping)的(de)裝備(bei)來(lai)選擇，針對大(da)部(bu)分中小(xiao)批量生(sheng)產(chan)(chan)(chan)的(de)制(zhi)(zhi)造企業，選擇數控(kong)機床來(lai)替(ti)代舊機床或增強生(sheng)產(chan)(chan)(chan)能(neng)力已是發展趨勢。

　　比(bi)較普(pu)通和數控(kong)兩類機(ji)床的(de)性能，數控(kong)機(ji)床具有加(jia)(jia)工復雜(za)形面零件能力強、適應(ying)多種加(jia)(jia)工對象（柔性強）；加(jia)(jia)工質量、精度和加(jia)(jia)工效率高；適應(ying)CAD/CAM聯網、適合制(zhi)造(zao)加(jia)(jia)工信息集成管理；設備的(de)利用率高、正(zheng)常運行費用低等特點。

　　選(xuan)擇數(shu)控(kong)機床是一(yi)個綜合性技術問題(ti)(ti)，現在無論國(guo)內還是國(guo)外，都能(neng)生產提供多(duo)種多(duo)樣的(de)(de)(de)設(she)備(bei)(bei)。數(shu)控(kong)機床經(jing)幾十年發展已(yi)演(yan)變出一(yi)個龐(pang)大家族群，能(neng)完成各種各樣的(de)(de)(de)加工制造要(yao)求。如何(he)(he)從(cong)品種繁多(duo)、價格(ge)昂貴的(de)(de)(de)設(she)備(bei)(bei)中(zhong)選(xuan)擇適(shi)用的(de)(de)(de)設(she)備(bei)(bei)，如何(he)(he)使這些設(she)備(bei)(bei)在制造中(zhong)充(chong)分發揮(hui)作用而且(qie)又能(neng)滿足企(qi)業(ye)以后的(de)(de)(de)發展，如何(he)(he)正確、合理(li)地選(xuan)購(gou)與主(zhu)機配套的(de)(de)(de)附件(jian)、工具、軟(ruan)件(jian)技術、售后技術服務等，使采購(gou)的(de)(de)(de)設(she)備(bei)(bei)能(neng)達到較(jiao)好的(de)(de)(de)投入比……這些問題(ti)(ti)都是廣大采購(gou)者必須考慮，并(bing)逐一(yi)要(yao)處(chu)理(li)好的(de)(de)(de)問題(ti)(ti)。

　　一(yi)、確定(ding)典型加(jia)工工件(jian)“族(zu)”

　　確(que)定(ding)加工(gong)(gong)什么樣零件(jian)是選擇設備(bei)的第(di)一步(bu)(bu)。企業根據技術改(gai)造和(he)生(sheng)產(chan)發展需要(yao)，確(que)定(ding)有(you)哪些(xie)(xie)零件(jian)、那些(xie)(xie)工(gong)(gong)序準備(bei)用新的加工(gong)(gong)設備(bei)來(lai)完成，要(yao)考慮到產(chan)品發展的遠景規劃。用成組(zu)技術把(ba)這些(xie)(xie)零件(jian)進行分組(zu)歸(gui)類(lei)，確(que)定(ding)準備(bei)主要(yao)加工(gong)(gong)對(dui)象的典型零件(jian)族。在歸(gui)類(lei)中往往會遇到零件(jian)規格大(da)(da)小相差很(hen)多、零件(jian)形(xing)狀(zhuang)相差較大(da)(da)、各類(lei)零件(jian)加工(gong)(gong)工(gong)(gong)時(shi)大(da)(da)大(da)(da)超過(guo)設備(bei)滿(man)負荷工(gong)(gong)時(shi)等問題，因此(ci)，要(yao)進一步(bu)(bu)選擇確(que)定(ding)生(sheng)產(chan)綱領又(you)比(bi)較接近(jin)要(yao)求的典型工(gong)(gong)件(jian)族。典型工(gong)(gong)件(jian)族按(an)外型可(ke)以分為菱(ling)形(xing)類(lei)（箱(xiang)體類(lei)）、板(ban)類(lei)、回轉體類(lei)（盤、套、軸(zhou)、法蘭）和(he)異形(xing)類(lei)等；按(an)加工(gong)(gong)精度要(yao)求又(you)可(ke)分普通級(ji)和(he)精密級(ji)等。典型零件(jian)分類(lei)清楚了(le)，基本加工(gong)(gong)設備(bei)也(ye)就比(bi)較明確(que)了(le)。

　　二、典型(xing)零件族的工藝(yi)規程設計(ji)

　　在(zai)確定加工(gong)(gong)(gong)零件后(hou)還必須用(yong)數控(kong)加工(gong)(gong)(gong)工(gong)(gong)(gong)藝(yi)的(de)學(xue)觀點對工(gong)(gong)(gong)藝(yi)流(liu)程(cheng)進行(xing)(xing)(xing)新(xin)的(de)規劃設(she)計，這里包括對原工(gong)(gong)(gong)藝(yi)生(sheng)(sheng)產(chan)(chan)流(liu)程(cheng)的(de)變革、探索(suo)實(shi)現(xian)新(xin)工(gong)(gong)(gong)藝(yi)方法的(de)可(ke)行(xing)(xing)(xing)性(xing)、探索(suo)實(shi)現(xian)現(xian)代生(sheng)(sheng)產(chan)(chan)管(guan)(guan)理和物流(liu)管(guan)(guan)理可(ke)行(xing)(xing)(xing)性(xing)、探索(suo)使用(yong)先進刀具工(gong)(gong)(gong)裝大幅度提(ti)高(gao)生(sheng)(sheng)產(chan)(chan)效率(lv)的(de)可(ke)行(xing)(xing)(xing)性(xing)、探索(suo)在(zai)生(sheng)(sheng)產(chan)(chan)線上數控(kong)設(she)備和其(qi)他設(she)備（普通的(de)、專機的(de)）的(de)合(he)理配制(zhi)工(gong)(gong)(gong)藝(yi)等，目(mu)的(de)是希(xi)望得(de)到使用(yong)數控(kong)機床后(hou)的(de)最佳(jia)工(gong)(gong)(gong)藝(yi)制(zhi)造(zao)流(liu)程(cheng)。下(xia)面是幾個典型類零件的(de)合(he)理加工(gong)(gong)(gong)工(gong)(gong)(gong)藝(yi)。

　　☆軸類零件：銑端面打中(zhong)心孔→數(shu)(shu)控(kong)車床（粗加(jia)工）→數(shu)(shu)控(kong)磨(mo)床（精加(jia)工）；

　　☆法蘭和盤類件：數控(kong)車床（粗加(jia)工）→車削(xue)中心（精加(jia)工）；

　　☆型(xing)腔模具零(ling)件：普通機床加工外形及(ji)基面(mian)→數控銑床加工型(xing)面(mian)→高速數控銑精加工→拋光或(huo)電腐蝕型(xing)面(mian)；

　　☆板類零件(jian)：雙軸銑床(chuang)或龍(long)門銑床(chuang)加(jia)(jia)工大平面(mian)→立式加(jia)(jia)工中心上加(jia)(jia)工各(ge)類孔；

　　☆箱體零件：立式(shi)加(jia)工(gong)中心(xin)上(shang)加(jia)工(gong)底面(mian)→臥式(shi)加(jia)工(gong)中心(xin)上(shang)加(jia)工(gong)四周面(mian)各工(gong)藝面(mian)。

　　在(zai)安排工藝流程中考慮(lv)下列因素(su)：

　　（1）選擇(ze)最短的(de)加工(gong)工(gong)藝(yi)流程(cheng)。

　　（2）數控機床有相當大(da)適應性，但也不是(shi)萬能(neng)的(de)(de)，從(cong)經濟(ji)觀點考慮(lv)，典(dian)型工(gong)件族中每一(yi)種零件都有一(yi)個(ge)經濟(ji)批量，應在經濟(ji)批量基礎(chu)上(shang)使(shi)用(yong)比較先進的(de)(de)工(gong)藝手段(duan)。

　　（3）盡量發揮機床的(de)(de)各種工(gong)藝特點，追求最(zui)大限度地發揮數控機床的(de)(de)綜(zong)合加工(gong)能(neng)力特長（多工(gong)序(xu)集中(zhong)的(de)(de)工(gong)藝特點），應在生產流(liu)程(cheng)中(zhong)配置最(zui)少的(de)(de)機床數量、最(zui)少的(de)(de)工(gong)藝裝(zhuang)備和(he)夾具。

　　（4）要(yao)考(kao)慮(lv)生產線或生產車間(jian)的(de)(de)各(ge)種(zhong)設(she)備能(neng)力的(de)(de)平(ping)衡(heng)。作(zuo)為單臺(tai)數控(kong)機床的(de)(de)選擇或一(yi)(yi)條生產線的(de)(de)配置(zhi)，單一(yi)(yi)的(de)(de)設(she)備不(bu)可能(neng)完全包下(xia)一(yi)(yi)個工(gong)件(jian)的(de)(de)全部加工(gong)工(gong)序(xu)，必然有和其他設(she)備的(de)(de)工(gong)序(xu)轉接，各(ge)設(she)備之間(jian)的(de)(de)生產能(neng)力要(yao)平(ping)衡(heng)，滿足生產節拍(pai)的(de)(de)綜合(he)要(yao)求，所以安排(pai)每臺(tai)設(she)備上的(de)(de)工(gong)序(xu)數量、加工(gong)工(gong)序(xu)順序(xu)等既要(yao)發(fa)揮各(ge)臺(tai)數控(kong)機床的(de)(de)特長、滿足精度要(yao)求，還要(yao)進一(yi)(yi)步應考(kao)慮(lv)各(ge)臺(tai)機床上工(gong)件(jian)轉序(xu)時工(gong)藝基(ji)準的(de)(de)合(he)理使用。

　　（5）在(zai)安(an)排數(shu)控加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝中(zhong)(zhong)(zhong)經(jing)常(chang)碰到的(de)(de)(de)問(wen)題是工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)序(xu)(xu)集(ji)中(zhong)(zhong)(zhong)與工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)漸精(jing)原則的(de)(de)(de)矛盾。在(zai)數(shu)控機床(chuang)(chuang)的(de)(de)(de)使(shi)用(yong)上(shang)，人們普(pu)遍采(cai)用(yong)將多(duo)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)序(xu)(xu)集(ji)中(zhong)(zhong)(zhong)在(zai)一臺機床(chuang)(chuang)上(shang)完成(cheng)的(de)(de)(de)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝集(ji)中(zhong)(zhong)(zhong)原則，以此來(lai)追求(qiu)(qiu)提高生產率，縮短零件(jian)加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)周期，甚至希望工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)件(jian)在(zai)一次(ci)(ci)裝卡(ka)中(zhong)(zhong)(zhong)全部加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)完畢。但實際上(shang)對一些復雜的(de)(de)(de)、精(jing)度要求(qiu)(qiu)較高的(de)(de)(de)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)件(jian)，由(you)于在(zai)加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)過程中(zhong)(zhong)(zhong)的(de)(de)(de)熱變(bian)形(xing)、內應(ying)力引起的(de)(de)(de)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)件(jian)變(bian)形(xing)、工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)夾(jia)具(ju)夾(jia)緊變(bian)形(xing)、熱處理要求(qiu)(qiu)時效等工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝因素和程編(bian)者操作因素等，很難一次(ci)(ci)裝卡(ka)完成(cheng)全部加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)。基本工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝準則中(zhong)(zhong)(zhong)對加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)零件(jian)的(de)(de)(de)逐步(bu)精(jing)化要求(qiu)(qiu)制約著工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)序(xu)(xu)集(ji)中(zhong)(zhong)(zhong)的(de)(de)(de)數(shu)量，妥善處理這兩者矛盾是數(shu)控加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)(gong)(gong)(gong)藝的(de)(de)(de)重要內容。

　　（6）在對典(dian)型工(gong)件族工(gong)藝(yi)流(liu)程的(de)安排中(zhong)，應妥(tuo)善(shan)安排各臺機床(chuang)和(he)生(sheng)產線的(de)手工(gong)調(diao)整(zheng)和(he)檢測等工(gong)作(zuo)，即人工(gong)干預的(de)影響(xiang)。企(qi)業要(yao)根據自身的(de)技術裝備(bei)能力(li)(li)、技術水(shui)平(ping)和(he)技術改造投入的(de)力(li)(li)度(du)，確定在工(gong)藝(yi)流(liu)程中(zhong)人工(gong)干預的(de)程度(du)，這決定了對選擇數(shu)控機床(chuang)的(de)自動化水(shui)平(ping)和(he)功能要(yao)求。應客(ke)觀考慮適當采用手工(gong)調(diao)整(zheng)來補充企(qi)業要(yao)達到完全自動化的(de)能力(li)(li)，對企(qi)業的(de)工(gong)藝(yi)能力(li)(li)和(he)設(she)備(bei)水(shui)平(ping)確切定位。

　　三、數(shu)控機床主要特征(zheng)規格的(de)選擇

　　機床(chuang)特征規格應包(bao)括(kuo)機型、機床(chuang)規格參(can)數(shu)和機床(chuang)主(zhu)電機功率等。在確(que)定工(gong)藝內容(rong)的前提(ti)下，機型選擇(ze)就較明確(que)了。例如(ru)，回(hui)轉(zhuan)體(ti)零件加工(gong)主(zhu)要(yao)可供選擇(ze)設備有車(che)(che)床(chuang)、車(che)(che)削中心、數(shu)控磨床(chuang)等；箱體(ti)的加工(gong)則應以立式或臥式加工(gong)中心為主(zhu)。

　　數(shu)控(kong)機(ji)(ji)床已發(fa)展成品(pin)(pin)種繁(fan)多(duo)、可供廣泛(fan)選(xuan)擇的(de)商品(pin)(pin)，在(zai)(zai)機(ji)(ji)型(xing)(xing)選(xuan)擇中應在(zai)(zai)滿(man)(man)足(zu)加(jia)(jia)工(gong)(gong)(gong)工(gong)(gong)(gong)藝要(yao)(yao)求(qiu)的(de)前提下越簡單越好(hao)。例如(ru)，車(che)削中心(xin)(xin)和數(shu)控(kong)車(che)床都可以(yi)加(jia)(jia)工(gong)(gong)(gong)軸類零件(jian)，但(dan)一臺滿(man)(man)足(zu)同樣(yang)加(jia)(jia)工(gong)(gong)(gong)規(gui)格(ge)(ge)的(de)車(che)削中心(xin)(xin)價(jia)格(ge)(ge)要(yao)(yao)比數(shu)控(kong)車(che)床貴幾倍，如(ru)果(guo)沒有進(jin)一步工(gong)(gong)(gong)藝要(yao)(yao)求(qiu)，選(xuan)數(shu)控(kong)車(che)床應是合理的(de)。在(zai)(zai)加(jia)(jia)工(gong)(gong)(gong)型(xing)(xing)腔模(mo)具(ju)零件(jian)中，同規(gui)格(ge)(ge)的(de)數(shu)控(kong)銑床和加(jia)(jia)工(gong)(gong)(gong)中心(xin)(xin)都能滿(man)(man)足(zu)基(ji)本加(jia)(jia)工(gong)(gong)(gong)要(yao)(yao)求(qiu)，但(dan)兩(liang)種機(ji)(ji)床價(jia)格(ge)(ge)相差20%～50%，所以(yi)在(zai)(zai)模(mo)具(ju)加(jia)(jia)工(gong)(gong)(gong)中要(yao)(yao)采用(yong)常更換刀(dao)具(ju)的(de)工(gong)(gong)(gong)藝可安(an)排選(xuan)用(yong)加(jia)(jia)工(gong)(gong)(gong)中心(xin)(xin)，而固定一把(ba)刀(dao)具(ju)長時間銑削的(de)可選(xuan)用(yong)數(shu)控(kong)銑床。

　　數控機(ji)床(chuang)(chuang)(chuang)的(de)(de)(de)(de)(de)(de)最主(zhu)要規格是(shi)幾(ji)個(ge)數控軸的(de)(de)(de)(de)(de)(de)行(xing)(xing)程(cheng)范圍和(he)主(zhu)軸電機(ji)功(gong)率(lv)。機(ji)床(chuang)(chuang)(chuang)的(de)(de)(de)(de)(de)(de)三個(ge)基(ji)本(ben)直(zhi)線坐(zuo)標(biao)（X、Y、Z）行(xing)(xing)程(cheng)反映(ying)該機(ji)床(chuang)(chuang)(chuang)允許(xu)(xu)的(de)(de)(de)(de)(de)(de)加(jia)工(gong)(gong)(gong)(gong)(gong)空間(jian)，在車床(chuang)(chuang)(chuang)中兩個(ge)坐(zuo)標(biao)（X、Z）反映(ying)允許(xu)(xu)回轉體的(de)(de)(de)(de)(de)(de)大(da)小(xiao)(xiao)。一般情況(kuang)下加(jia)工(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)件(jian)(jian)(jian)的(de)(de)(de)(de)(de)(de)輪廓尺寸(cun)應(ying)在機(ji)床(chuang)(chuang)(chuang)的(de)(de)(de)(de)(de)(de)加(jia)工(gong)(gong)(gong)(gong)(gong)空間(jian)范圍之(zhi)內，例(li)(li)如(ru)，典型工(gong)(gong)(gong)(gong)(gong)件(jian)(jian)(jian)是(shi)450 mm ×450 mm ×450 mm的(de)(de)(de)(de)(de)(de)箱體，那么應(ying)選(xuan)取工(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)臺(tai)(tai)(tai)面(mian)尺寸(cun)為(wei)500mm×500 mm的(de)(de)(de)(de)(de)(de)加(jia)工(gong)(gong)(gong)(gong)(gong)中心。選(xuan)用(yong)工(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)臺(tai)(tai)(tai)面(mian)比(bi)典型工(gong)(gong)(gong)(gong)(gong)件(jian)(jian)(jian)稍大(da)一些是(shi)出(chu)于(yu)安裝(zhuang)夾具(ju)考慮的(de)(de)(de)(de)(de)(de)。機(ji)床(chuang)(chuang)(chuang)工(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)臺(tai)(tai)(tai)面(mian)尺寸(cun)和(he)三個(ge)直(zhi)線坐(zuo)標(biao)行(xing)(xing)程(cheng)都有(you)一定的(de)(de)(de)(de)(de)(de)比(bi)例(li)(li)關系(xi)，如(ru)上述(shu)工(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)臺(tai)(tai)(tai)（500 mm ×500 mm）的(de)(de)(de)(de)(de)(de)機(ji)床(chuang)(chuang)(chuang)，x軸行(xing)(xing)程(cheng)一般為(wei)（700～800）mm、y軸為(wei)（500～700）mm、z軸為(wei)（500～600）mm左右。因此，工(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)臺(tai)(tai)(tai)面(mian)的(de)(de)(de)(de)(de)(de)大(da)小(xiao)(xiao)基(ji)本(ben)上確定了加(jia)工(gong)(gong)(gong)(gong)(gong)空間(jian)的(de)(de)(de)(de)(de)(de)大(da)小(xiao)(xiao)。個(ge)別(bie)情況(kuang)下也允許(xu)(xu)工(gong)(gong)(gong)(gong)(gong)件(jian)(jian)(jian)尺寸(cun)大(da)于(yu)坐(zuo)標(biao)行(xing)(xing)程(cheng)，這時(shi)必須要求零件(jian)(jian)(jian)上的(de)(de)(de)(de)(de)(de)加(jia)工(gong)(gong)(gong)(gong)(gong)區域處在行(xing)(xing)程(cheng)范圍之(zhi)內，而(er)且(qie)要考慮機(ji)床(chuang)(chuang)(chuang)工(gong)(gong)(gong)(gong)(gong)作(zuo)(zuo)臺(tai)(tai)(tai)的(de)(de)(de)(de)(de)(de)允許(xu)(xu)承載能力(li)，以及工(gong)(gong)(gong)(gong)(gong)件(jian)(jian)(jian)是(shi)否(fou)與機(ji)床(chuang)(chuang)(chuang)交換(huan)刀(dao)刀(dao)具(ju)的(de)(de)(de)(de)(de)(de)空間(jian)干涉、與機(ji)床(chuang)(chuang)(chuang)防護(hu)罩(zhao)等附件(jian)(jian)(jian)發生干涉等系(xi)列(lie)問(wen)題。

　　數(shu)控(kong)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)的(de)(de)(de)主(zhu)(zhu)(zhu)電(dian)機(ji)(ji)(ji)(ji)功(gong)(gong)率(lv)(lv)在同(tong)(tong)類規(gui)(gui)格機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)上(shang)也可(ke)以(yi)有(you)各種不同(tong)(tong)的(de)(de)(de)配置，一(yi)般情況(kuang)下反映(ying)了(le)該機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)的(de)(de)(de)切削(xue)(xue)(xue)剛(gang)(gang)性(xing)和主(zhu)(zhu)(zhu)軸(zhou)高速(su)(su)(su)性(xing)能。例如，輕型(xing)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)比標準型(xing)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)主(zhu)(zhu)(zhu)軸(zhou)電(dian)機(ji)(ji)(ji)(ji)功(gong)(gong)率(lv)(lv)就可(ke)能小1～2級。目前一(yi)般加工中心主(zhu)(zhu)(zhu)軸(zhou)轉速(su)(su)(su)在（4000～8000）r/min，高速(su)(su)(su)型(xing)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)立式(shi)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)可(ke)達（20000～70000）r/min，臥式(shi)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)（10000～20000）r/min，其主(zhu)(zhu)(zhu)軸(zhou)電(dian)機(ji)(ji)(ji)(ji)功(gong)(gong)率(lv)(lv)也成倍加大(da)。主(zhu)(zhu)(zhu)軸(zhou)電(dian)機(ji)(ji)(ji)(ji)功(gong)(gong)率(lv)(lv)反映(ying)了(le)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)的(de)(de)(de)切削(xue)(xue)(xue)效率(lv)(lv)，從另一(yi)個(ge)側面(mian)也反映(ying)了(le)切削(xue)(xue)(xue)剛(gang)(gang)性(xing)和機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)整體剛(gang)(gang)度。在現代中小型(xing)數(shu)控(kong)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)中，主(zhu)(zhu)(zhu)軸(zhou)箱(xiang)的(de)(de)(de)機(ji)(ji)(ji)(ji)械變速(su)(su)(su)已較少(shao)采用(yong)(yong)，往往都采用(yong)(yong)功(gong)(gong)率(lv)(lv)較大(da)的(de)(de)(de)交流可(ke)調(diao)速(su)(su)(su)電(dian)機(ji)(ji)(ji)(ji)直聯(lian)主(zhu)(zhu)(zhu)軸(zhou)，甚至采用(yong)(yong)電(dian)主(zhu)(zhu)(zhu)軸(zhou)結構。這樣的(de)(de)(de)結構在低(di)速(su)(su)(su)中扭矩(ju)受到(dao)限制，即調(diao)速(su)(su)(su)電(dian)機(ji)(ji)(ji)(ji)在低(di)轉速(su)(su)(su)時(shi)輸(shu)出功(gong)(gong)率(lv)(lv)下降(jiang)，為了(le)確保低(di)速(su)(su)(su)輸(shu)出扭矩(ju)，就得采用(yong)(yong)大(da)功(gong)(gong)率(lv)(lv)電(dian)機(ji)(ji)(ji)(ji)，所以(yi)同(tong)(tong)規(gui)(gui)格機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)數(shu)控(kong)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)主(zhu)(zhu)(zhu)軸(zhou)電(dian)機(ji)(ji)(ji)(ji)比普通機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)大(da)好幾(ji)倍。當使用(yong)(yong)單位(wei)的(de)(de)(de)一(yi)些典(dian)型(xing)工件上(shang)有(you)大(da)量的(de)(de)(de)低(di)速(su)(su)(su)加工時(shi)，也必須對(dui)選擇機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)的(de)(de)(de)低(di)速(su)(su)(su)輸(shu)出扭矩(ju)進行校核。輕型(xing)機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)在價(jia)格上(shang)肯定便(bian)宜，要求用(yong)(yong)戶根據(ju)自己的(de)(de)(de)典(dian)型(xing)工件毛坯余量大(da)小、切削(xue)(xue)(xue)能力（單位(wei)時(shi)間金屬(shu)切除量）、要求達到(dao)的(de)(de)(de)加工精(jing)度、實際能配置什么樣刀具(ju)等因素(su)綜合選擇機(ji)(ji)(ji)(ji)床(chuang)(chuang)(chuang)(chuang)(chuang)。

　　近年(nian)來數控機床上(shang)高速(su)化趨勢發(fa)展很快(kuai)，主(zhu)(zhu)軸(zhou)從每分鐘幾(ji)千轉到(dao)幾(ji)萬轉，直線坐標(biao)快(kuai)速(su)移(yi)動速(su)度從（10～20）m/min上(shang)升(sheng)到(dao)80m/min以(yi)上(shang)，當然機床價格也相應上(shang)升(sheng)，用(yong)戶單位必須根據自己的技術能(neng)(neng)力(li)和配套能(neng)(neng)力(li)做出(chu)合理(li)選擇。例(li)如，立(li)式加工(gong)中心上(shang)主(zhu)(zhu)軸(zhou)最(zui)高轉速(su)可(ke)達(da)（50000～80000）r/min，除了(le)一些(xie)(xie)加工(gong)特例(li)以(yi)外，一般相配套的刀具就很昂貴。一些(xie)(xie)高速(su)車床都可(ke)以(yi)達(da)到(dao)（6000～8000）r/min以(yi)上(shang)，這時車刀的配置要求也很高。

　　對(dui)少(shao)量特(te)殊工(gong)件(jian)僅(jin)靠三個直線坐(zuo)標(biao)加(jia)工(gong)不能(neng)滿足要(yao)(yao)求(qiu)，要(yao)(yao)另外增加(jia)回(hui)轉(zhuan)坐(zuo)標(biao)（A、B、C）或附加(jia)工(gong)坐(zuo)標(biao)（U、V、W）等，目(mu)前機床(chuang)市場上這些要(yao)(yao)求(qiu)都能(neng)滿足，但機床(chuang)價格會增長很多，尤其是對(dui)一些要(yao)(yao)求(qiu)多軸(zhou)聯(lian)(lian)動加(jia)工(gong)要(yao)(yao)求(qiu)，如四(si)軸(zhou)、五軸(zhou)聯(lian)(lian)動加(jia)工(gong)，必須對(dui)相應配(pei)套的編程軟件(jian)、測(ce)量手段等有全面考(kao)慮和安排。

　　四、機(ji)床精度的選(xuan)擇

　　典(dian)型(xing)(xing)零件的(de)(de)(de)關鍵部(bu)位加工精(jing)度要求決定了選(xuan)擇數(shu)控機(ji)床(chuang)的(de)(de)(de)精(jing)度等(deng)級(ji)。數(shu)控機(ji)床(chuang)根據用途(tu)又分為(wei)簡易型(xing)(xing)、全功(gong)(gong)能型(xing)(xing)、超(chao)精(jing)密型(xing)(xing)等(deng)，其(qi)(qi)能達到(dao)的(de)(de)(de)精(jing)度也是(shi)各不一(yi)樣的(de)(de)(de)。簡易型(xing)(xing)目前還用于(yu)一(yi)部(bu)分車(che)床(chuang)和銑床(chuang)，其(qi)(qi)最小運動分辯率為(wei)0.01mm，運動精(jing)度和加工精(jing)度都(dou)在（0.03～0.05）mm以上(shang)。超(chao)精(jing)密型(xing)(xing)用于(yu)特殊加工，其(qi)(qi)精(jing)度可達0.001mm以下。這里主(zhu)要討論應用最多的(de)(de)(de)全功(gong)(gong)能數(shu)控機(ji)床(chuang)（以加工中心(xin)為(wei)主(zhu)）。

　　按精(jing)度(du)可分為普通型和精(jing)密型，一般數控機床(chuang)精(jing)度(du)檢驗項(xiang)目都有(you)20～30項(xiang)，但其(qi)最(zui)有(you)特征(zheng)項(xiang)目是(shi)：單軸定(ding)位(wei)精(jing)度(du)、單軸重復定(ding)位(wei)精(jing)度(du)和兩軸以上聯(lian)動加(jia)工出試件(jian)的(de)圓度(du)。

　　定(ding)(ding)位(wei)(wei)(wei)(wei)精度(du)和重復(fu)定(ding)(ding)位(wei)(wei)(wei)(wei)精度(du)綜合反(fan)映了該軸(zhou)各(ge)運動(dong)(dong)(dong)部(bu)件(jian)(jian)的(de)(de)綜合精度(du)。尤其是(shi)重復(fu)定(ding)(ding)位(wei)(wei)(wei)(wei)精度(du)，它反(fan)映了該軸(zhou)在行(xing)程內任意(yi)定(ding)(ding)位(wei)(wei)(wei)(wei)點(dian)的(de)(de)定(ding)(ding)位(wei)(wei)(wei)(wei)穩定(ding)(ding)性(xing)，這是(shi)衡量該軸(zhou)能(neng)否穩定(ding)(ding)可靠(kao)工(gong)作的(de)(de)基本指標。目前數控系統(tong)中軟(ruan)件(jian)(jian)都有(you)豐富的(de)(de)誤(wu)差補償功(gong)能(neng)，能(neng)對進給傳動(dong)(dong)(dong)鏈上各(ge)環(huan)節系統(tong)誤(wu)差進行(xing)穩定(ding)(ding)的(de)(de)補償。例如(ru)，傳動(dong)(dong)(dong)鏈各(ge)環(huan)節的(de)(de)間隙、彈性(xing)變形和接觸剛度(du)等變化因素，它們往(wang)往(wang)隨著(zhu)工(gong)作臺的(de)(de)負載大小、移(yi)動(dong)(dong)(dong)距離長短(duan)、移(yi)動(dong)(dong)(dong)定(ding)(ding)位(wei)(wei)(wei)(wei)速度(du)的(de)(de)快慢等反(fan)映出不同的(de)(de)瞬時運動(dong)(dong)(dong)量。在一些開環(huan)和半閉環(huan)進給伺服系統(tong)中，測(ce)量元(yuan)件(jian)(jian)以后的(de)(de)機械(xie)驅動(dong)(dong)(dong)元(yuan)件(jian)(jian)，受各(ge)種(zhong)偶然因素影響(xiang)，也有(you)相(xiang)當大的(de)(de)隨機誤(wu)差影響(xiang)，如(ru)滾(gun)珠絲杠熱伸長引起的(de)(de)工(gong)作臺實際定(ding)(ding)位(wei)(wei)(wei)(wei)位(wei)(wei)(wei)(wei)置漂移(yi)等。總之，如(ru)果能(neng)選擇，那(nei)么就選重復(fu)定(ding)(ding)位(wei)(wei)(wei)(wei)精度(du)最好的(de)(de)設備！

　　銑(xian)(xian)(xian)削圓柱面(mian)精度(du)或(huo)銑(xian)(xian)(xian)削空間(jian)螺旋槽(cao)（螺紋(wen)）是綜合評價該機(ji)(ji)床有關數控(kong)(kong)(kong)軸(zhou)(zhou)(zhou)(zhou)（兩(liang)軸(zhou)(zhou)(zhou)(zhou)或(huo)三軸(zhou)(zhou)(zhou)(zhou)）伺服跟隨運(yun)(yun)(yun)動(dong)(dong)特性和(he)數控(kong)(kong)(kong)系(xi)(xi)統(tong)插補功(gong)能的(de)指標，評價方(fang)(fang)法(fa)是測量加工(gong)出(chu)圓柱面(mian)的(de)圓度(du)。在(zai)(zai)數控(kong)(kong)(kong)機(ji)(ji)床試切(qie)(qie)件(jian)中(zhong)還有銑(xian)(xian)(xian)斜方(fang)(fang)形四邊(bian)加工(gong)法(fa)，也可判(pan)斷兩(liang)個(ge)可控(kong)(kong)(kong)軸(zhou)(zhou)(zhou)(zhou)在(zai)(zai)直線插補運(yun)(yun)(yun)動(dong)(dong)時的(de)精度(du)。在(zai)(zai)做這項試切(qie)(qie)時，把(ba)用于精加工(gong)的(de)立(li)銑(xian)(xian)(xian)刀裝到機(ji)(ji)床主(zhu)軸(zhou)(zhou)(zhou)(zhou)上(shang)(shang)，銑(xian)(xian)(xian)削放(fang)置在(zai)(zai)工(gong)作臺上(shang)(shang)的(de)圓形試件(jian)，對中(zhong)小(xiao)型(xing)機(ji)(ji)床圓形試件(jian)一般取在(zai)(zai)Ф200～Ф300，然后把(ba)切(qie)(qie)完的(de)試件(jian)放(fang)到圓度(du)儀上(shang)(shang)，測出(chu)其加工(gong)表面(mian)的(de)圓度(du)。銑(xian)(xian)(xian)出(chu)圓柱面(mian)上(shang)(shang)有明顯(xian)銑(xian)(xian)(xian)刀振紋(wen)反映(ying)該機(ji)(ji)床插補速度(du)不(bu)穩定；銑(xian)(xian)(xian)出(chu)的(de)圓度(du)有明顯(xian)橢圓誤差，反映(ying)插補運(yun)(yun)(yun)動(dong)(dong)的(de)兩(liang)個(ge)可控(kong)(kong)(kong)軸(zhou)(zhou)(zhou)(zhou)系(xi)(xi)統(tong)增益不(bu)匹配(pei)；在(zai)(zai)圓形表面(mian)上(shang)(shang)每(mei)一可控(kong)(kong)(kong)軸(zhou)(zhou)(zhou)(zhou)運(yun)(yun)(yun)動(dong)(dong)換方(fang)(fang)向的(de)點位上(shang)(shang)有停刀點痕跡（在(zai)(zai)連續切(qie)(qie)削運(yun)(yun)(yun)動(dong)(dong)中(zhong)，在(zai)(zai)某(mou)一位置停止(zhi)進給運(yun)(yun)(yun)動(dong)(dong)刀具就(jiu)會在(zai)(zai)加工(gong)表面(mian)上(shang)(shang)形成一小(xiao)段多(duo)切(qie)(qie)去金屬的(de)痕跡）時，反映(ying)該軸(zhou)(zhou)(zhou)(zhou)正反向間(jian)隙沒(mei)有調整好。

　　單軸定位精(jing)度(du)是指(zhi)在該軸行(xing)程內任意(yi)一(yi)個點(dian)定位時(shi)的(de)(de)誤差范圍，它直接反映了機床的(de)(de)加工精(jing)度(du)能力，所以是數(shu)控機床最關鍵(jian)技(ji)術指(zhi)標(biao)(biao)(biao)。目前全世(shi)界各(ge)國對這(zhe)指(zhi)標(biao)(biao)(biao)的(de)(de)規(gui)定、定義、測(ce)(ce)量(liang)方法和數(shu)據處理等(deng)有所不同，在各(ge)類數(shu)控機床樣本(ben)資料(liao)介紹中，常用(yong)(yong)的(de)(de)標(biao)(biao)(biao)準(zhun)(zhun)有美國標(biao)(biao)(biao)準(zhun)(zhun)（NAS）和美國機床制(zhi)造商協會(hui)推(tui)薦標(biao)(biao)(biao)準(zhun)(zhun)、德國標(biao)(biao)(biao)準(zhun)(zhun)（VDI）、日本(ben)標(biao)(biao)(biao)準(zhun)(zhun)（JIS）、國際(ji)標(biao)(biao)(biao)準(zhun)(zhun)化組織（ISO）和我(wo)國國家標(biao)(biao)(biao)準(zhun)(zhun)（GB）。在這(zhe)些標(biao)(biao)(biao)準(zhun)(zhun)中規(gui)定最低的(de)(de)是日本(ben)標(biao)(biao)(biao)準(zhun)(zhun)，因(yin)為它的(de)(de)測(ce)(ce)量(liang)方法是使用(yong)(yong)單組穩定數(shu)據為基礎，然(ran)后又取出(chu)用(yong)(yong)±值(zhi)把(ba)誤差值(zhi)壓縮(suo)一(yi)半，所以用(yong)(yong)它的(de)(de)測(ce)(ce)量(liang)方法測(ce)(ce)出(chu)的(de)(de)定位精(jing)度(du)往往比(bi)用(yong)(yong)其他標(biao)(biao)(biao)準(zhun)(zhun)測(ce)(ce)出(chu)的(de)(de)相差一(yi)倍(bei)以上(shang)。

　　其他幾(ji)種標準盡管處理數據上(shang)有所區別，但都反(fan)映了要(yao)按誤(wu)差統計規律來分析測(ce)量定位(wei)精度，即對數控機床(chuang)某一可控軸行程中某一個定位(wei)點(dian)誤(wu)差，應該(gai)(gai)反(fan)映出該(gai)(gai)點(dian)在以后(hou)機床(chuang)長期使用中成千上(shang)萬次在此定位(wei)的誤(wu)差，而(er)我們(men)在測(ce)量時只能測(ce)量有限次數（一般5～7次）。