C3級(ji)絲(si)杠(gang)需(xu)滿(man)足(ju)機(ji)床(chuang)最(zui)大(dai)軸(zhou)向(xiang)力(li)需(xu)求(qiu)。以(yi)某(mou)立(li)式(shi)加(jia)工(gong)中(zhong)心(xin)為(wei)例(li),其(qi)主(zhu)軸(zhou)重(chong)量(liang)2000kg,切(qie)削(xiao)力(li)5000N,導(dao)軌(gui)摩(mo)擦(ca)係(ji)數(shuo)0.05,則(ze)總(zong)軸(zhou)向(xiang)力(li)為(wei):
F=MGμ+F切(qie)削(xiao)
=2000×9.8×0.05 + 5000
=980N + 5000N
=5980N
需(xu)選(xuan)擇(ze)動(dong)額(e)定(ding)負(fu)荷(he)(C)為(wei)計(ji)算(suan)值(zhi)3倍(bei)以(yi)上(shang)的(di)絲(si)杠(gang),如(ru)某(mou)品(pin)牌(pai)SFU4010-C3型(xing),其(qi)動(dong)額(e)定(ding)負(fu)荷(he)達(da)28000N,安(an)全(quan)係(ji)數(shuo)達(da)4.7,可(ke)避(bi)免(wen)長(zhang)期(qi)過(guo)載(zai)導(dao)致(zhi)的(di)疲(pi)勞(lao)失(shi)效(xiao)。
高(gao)速(su)切(qie)削(xiao)時(shi),慣(guan)性(xing)力(li)可(ke)能(neng)成(cheng)為(wei)主(zhu)導(dao)因(yin)素(su)。假(jia)設(she)加(jia)速(su)時(shi)間(jian)0.1秒(miao),則(ze)動(dong)態(tai)軸(zhou)向(xiang)力(li)增(zeng)加(jia):
F慣(guan)=MA=2000×(5000/0.1)/9.8≈102040N
此(ci)時(shi)需(xu)通(tong)過(guo)DmN值(zhi)(節(jie)圓(yuan)直(zhi)徑(jing)×轉(zhuan)速(su))校(jiao)驗(yan)絲(si)杠(gang)壽(shou)命(ming)。例(li)如(ru),當(dang)導(dao)程(cheng)10mm、轉(zhuan)速(su)3000rpm時(shi):
DmN=40mm×3000rpm=120000
(需(xu)≤70000標(biao)準(zhun)值(zhi)時(shi),需(xu)降(xiang)低(di)轉(zhuan)速(su)或(huo)選(xuan)擇(ze)更(geng)大(dai)直(zhi)徑(jing))
C3級(ji)對(dui)應(ying)ISO 3408-3標(biao)準(zhun),其(qi)300mm行(hang)程(cheng)誤(wu)差(chai)≤±0.015mm,任(ren)意(yi)300mm反(fan)向(xiang)間(jian)隙(xi)≤0.008mm,適(kuo)合(ge)以(yi)下(xia)場(chang)景(jing):
模(mu)具(ju)加(jia)工(gong):型(xing)腔(qiang)表(biao)麵(mian)粗(cu)糙(cao)度(duo)Ra≤0.8μm
精(jing)密(mi)零(ling)件(jian):孔(kong)徑(jing)公(gong)差(chai)±0.005mm
五(wu)軸(zhou)聯(lian)動(dong):聯(lian)動(dong)精(jing)度(duo)≤0.01mm/軸(zhou)
為(wei)進(jin)一(yi)步(bu)控(kong)製(zhi)誤(wu)差(chai),需(xu)采(cai)用(yong):
雙(shuang)螺(luo)母(mu)預(yu)壓(ya):通(tong)過(guo)0.03mm預(yu)壓(ya)量(liang)消(xiao)除(chu)軸(zhou)向(xiang)間(jian)隙(xi),實(shi)測(ce)回(hui)程(cheng)誤(wu)差(chai)≤0.005mm
溫(wen)度(duo)補(bu)償(chang):集(ji)成(cheng)PT100溫(wen)度(duo)傳(zhuan)感(gan)器(qi),根(gen)據(ju)溫(wen)升(sheng)自(zi)動(dong)修(xiu)正(zheng)螺(luo)距(ju)誤(wu)差(chai)(每(mei)℃膨(peng)脹(zhang)0.012mm/m)
激(ji)光(guang)校(jiao)準(zhun):使(shi)用(yong)激(ji)光(guang)幹(gan)涉(she)儀(yi)檢(jian)測(ce)螺(luo)距(ju)累(lei)積(ji)誤(wu)差(chai),通(tong)過(guo)數(shuo)控(kong)係(ji)統(tong)補(bu)償(chang)至(zhi)±0.003mm
C3級(ji)絲(si)杠(gang)需(xu)兼(jian)顧(gu)高(gao)剛(gang)性(xing)與(yu)高(gao)速(su)性(xing)。以(yi)SFU5020-C3為(wei)例(li):
固(gu)定(ding)-支(zhi)撐(cheng)安(an)裝(zhuang)時(shi),臨(lin)界(jie)轉(zhuan)速(su)計(ji)算(suan):
Nc=9910×(d²/L²)
(d=50mm,L=3000mm,Nc≈275rpm)
實(shi)際(ji)運(yun)行(hang)轉(zhuan)速(su)需(xu)控(kong)製(zhi)在(zai)Nc的(di)70%以(yi)內(nei),即(ji)≤192rpm,或(huo)通(tong)過(guo)增(zeng)大(dai)直(zhi)徑(jing)提(ti)升(sheng)極(ji)限(xian)。
采(cai)用(yong)以(yi)下(xia)結(jie)構(gou)降(xiang)低(di)振(zhen)動(dong):
中(zhong)空(kong)冷(leng)卻(que):循(xun)環(huan)冷(leng)卻(que)液(ye)將(qiang)溫(wen)升(sheng)控(kong)製(zhi)在(zai)2℃以(yi)內(nei),減(jian)少(shao)熱(re)變(bian)形(xing)
阻(zu)尼(ni)螺(luo)母(mu):內(nei)部(bu)嵌(kan)入(ru)橡(xiang)膠(jiao)阻(zu)尼(ni)環(huan),振(zhen)動(dong)加(jia)速(su)度(duo)降(xiang)低(di)40%
對(dui)稱(chen)支(zhi)撐(cheng):兩(liang)端(duan)采(cai)用(yong)配(pei)對(dui)角(jue)接(jie)觸(chu)軸(zhou)承(cheng)(接(jie)觸(chu)角(jue)60°),抗(kang)彎(wan)剛(gang)度(duo)提(ti)升(sheng)60%
某(mou)企(qi)業(ye)為(wei)提(ti)升(sheng)模(mu)具(ju)加(jia)工(gong)精(jing)度(duo),將(qiang)原(yuan)C7級(ji)絲(si)杠(gang)升(sheng)級(ji)為(wei)C3級(ji)SFU6316-C3:
參(shen)數(shuo)對(dui)比(bi):
| 指(zhi)標(biao) | C7級(ji) | C3級(ji) | 提(ti)升(sheng)效(xiao)果(guo) |
|---|---|---|---|
| 300mm誤(wu)差(chai) | ±0.05mm | ±0.012mm | 精(jing)度(duo)提(ti)升(sheng)76% |
| 表(biao)麵(mian)粗(cu)糙(cao)度(duo) | Ra1.6μm | Ra0.6μm | 表(biao)麵(mian)質(zhi)量(liang)提(ti)升(sheng)62.5% |
| 刀(dao)具(ju)壽(shou)命(ming) | 8小(xiao)時(shi) | 15小(xiao)時(shi) | 效(xiao)率(shuai)提(ti)升(sheng)87.5% |
成(cheng)本(ben)分(fen)析(xi):單(shan)軸(zhou)成(cheng)本(ben)增(zeng)加(jia)35%,但(dan)因(yin)良(liang)品(pin)率(shuai)提(ti)升(sheng)20%,綜(zeng)合(ge)成(cheng)本(ben)下(xia)降(xiang)18%。
負(fu)載(zai)計(ji)算(suan):明(ming)確(que)靜(jing)態(tai)/動(dong)態(tai)軸(zhou)向(xiang)力(li),選(xuan)擇(ze)動(dong)額(e)定(ding)負(fu)荷(he)≥3倍(bei)計(ji)算(suan)值(zhi)
精(jing)度(duo)匹(pi)配(pei):根(gen)據(ju)加(jia)工(gong)公(gong)差(chai)選(xuan)C3/C5級(ji),預(yu)留(liu)激(ji)光(guang)補(bu)償(chang)餘(yu)量(liang)
速(su)度(duo)校(jiao)驗(yan):通(tong)過(guo)DmN值(zhi)與(yu)臨(lin)界(jie)轉(zhuan)速(su)確(que)定(ding)安(an)全(quan)運(yun)行(hang)參(shen)數(shuo)
品(pin)牌(pai)驗(yan)證(zheng):要(yao)求(qiu)廠(han)家(jia)提(ti)供(gong)實(shi)測(ce)精(jing)度(duo)曲(qu)線(xian)與(yu)壽(shou)命(ming)測(ce)試(shi)報(bao)告(gao)
通(tong)過(guo)科(ke)學(xue)選(xuan)型(xing),C3級(ji)滾(gun)珠(zhu)絲(si)杠(gang)可(ke)助(zhu)力(li)數(shuo)控(kong)機(ji)床(chuang)實(shi)現(xian)“微(wei)米(mi)級(ji)”精(jing)度(duo)控(kong)製(zhi),為(wei)高(gao)端(duan)製(zhi)造(zao)提(ti)供(gong)核(he)心(xin)支(zhi)撐(cheng)。