根據錐柄(bing)角度(du)的不同, 常用固定(ding)頂尖(jian)可分為莫氏錐柄(bing)和特殊(shu)錐度(du)錐柄(bing)。對于(yu)莫氏錐柄(bing)頂尖(jian)的磨削(xue)加(jia)工(gong)(gong)車間有專用的工(gong)(gong)裝, 這里就不作(zuo)介紹了(le)。特殊(shu)錐度(du)錐柄(bing)固定(ding)頂尖(jian), 加(jia)工(gong)(gong)精度(du)和復雜(za)系數較(jiao)高。采(cai)用合理的工(gong)(gong)藝, 有利于(yu)提高特殊(shu)錐度(du)固定(ding)頂尖(jian)的加(jia)工(gong)(gong)精度(du)。 下面以在M 131W 上(shang)加(jia)工(gong)軋輥C A 8480 車床固定頂尖(jian)( 見附圖) 為例, 介紹特殊錐(zhui)度頂尖(jian)加(jia)工(gong)工(gong)藝 1. 確定加工順序 由附圖可(ke)(ke)以(yi)看出, 需(xu)磨削(xue)加工(gong)(gong)的(de)(de)(de)尺寸(cun)有(you)錐(zhui)(zhui)柄直徑(jing)7 9.5 m m 、錐(zhui)(zhui)度1∶7 的(de)(de)(de)錐(zhui)(zhui)面(mian)(mian)(mian)(mian)和直徑(jing)1 00 m m 、錐(zhui)(zhui)度60°的(de)(de)(de)錐(zhui)(zhui)尖(jian)(jian)工(gong)(gong)作(zuo)(zuo)面(mian)(mian)(mian)(mian)。而且錐(zhui)(zhui)尖(jian)(jian)工(gong)(gong)作(zuo)(zuo)面(mian)(mian)(mian)(mian)對1 ∶7 的(de)(de)(de)錐(zhui)(zhui)面(mian)(mian)(mian)(mian)同軸(zhou)度為(wei)0.015m m .根據粗基(ji)(ji)(ji)準(zhun)(zhun)(zhun)的(de)(de)(de)選擇原則(ze)(ze), 1 ∶7 錐(zhui)(zhui)面(mian)(mian)(mian)(mian)的(de)(de)(de)加工(gong)(gong)應(ying)以(yi)工(gong)(gong)件的(de)(de)(de)軸(zhou)線, 即(ji)工(gong)(gong)件的(de)(de)(de)左端中心孔和60°頂尖(jian)(jian)面(mian)(mian)(mian)(mian)作(zuo)(zuo)為(wei)粗基(ji)(ji)(ji)準(zhun)(zhun)(zhun)( 60°頂尖(jian)(jian)面(mian)(mian)(mian)(mian)作(zuo)(zuo)粗基(ji)(ji)(ji)準(zhun)(zhun)(zhun)可(ke)(ke)保證(zheng)60°頂尖(jian)(jian)面(mian)(mian)(mian)(mian)的(de)(de)(de)加工(gong)(gong)余(yu)量) .根據精基(ji)(ji)(ji)準(zhun)(zhun)(zhun)的(de)(de)(de)選擇原則(ze)(ze), 1∶7 的(de)(de)(de)錐(zhui)(zhui)面(mian)(mian)(mian)(mian)長度比60°錐(zhui)(zhui)尖(jian)(jian)長, 60°錐(zhui)(zhui)尖(jian)(jian)加工(gong)(gong)應(ying)以(yi)1 ∶7 錐(zhui)(zhui)面(mian)(mian)(mian)(mian)作(zuo)(zuo)精基(ji)(ji)(ji)準(zhun)(zhun)(zhun)。因此加工(gong)(gong)順(shun)序為(wei)先加工(gong)(gong)1∶7 的(de)(de)(de)錐(zhui)(zhui)面(mian)(mian)(mian)(mian)再加工(gong)(gong)60°頂尖(jian)(jian)面(mian)(mian)(mian)(mian)。 2. 裝夾方法 3. 錐面磨削加工 外(wai)圓錐(zhui)面(mian)磨(mo)削根據(ju)錐(zhui)面(mian)的大小和工(gong)件形狀(zhuang), 可采(cai)用以(yi)下(xia)三種磨(mo)削方(fang)法(fa): 轉動(dong)工(gong)作(zuo)臺來磨(mo)削錐(zhui)面(mian), 轉動(dong)頭(tou)架磨(mo)削外(wai)圓錐(zhui)面(mian)和轉動(dong)砂(sha)輪架磨(mo)削外(wai)圓錐(zhui)面(mian)。在(zai)這里(li)錐(zhui)柄錐(zhui)度1∶7 的磨(mo)削加(jia)(jia)工(gong)采(cai)用轉動(dong)工(gong)作(zuo)臺的方(fang)法(fa)。錐(zhui)柄部的角度可和軋輥(gun)車(che)床套筒配研, 大端接觸(chu), 接觸(chu)面(mian)8 0 % 以(yi)上。角度的誤(wu)差可調(diao)整工(gong)作(zuo)臺, 經過多次(ci)反復研配和磨(mo)削加(jia)(jia)工(gong)去除。 60°工(gong)(gong)作(zuo)(zuo)錐(zhui)(zhui)(zhui)(zhui)面(mian)(mian)的加(jia)工(gong)(gong), 通過四爪單動(dong)卡盤(pan)裝夾(jia)錐(zhui)(zhui)(zhui)(zhui)柄部位(wei), 轉(zhuan)(zhuan)動(dong)頭架(jia)和(he)砂(sha)輪(lun)架(jia)各15°, 采(cai)用組(zu)合(he)方式即可(ke)實現工(gong)(gong)作(zuo)(zuo)錐(zhui)(zhui)(zhui)(zhui)面(mian)(mian)的磨削加(jia)工(gong)(gong)。工(gong)(gong)作(zuo)(zuo)錐(zhui)(zhui)(zhui)(zhui)面(mian)(mian)角(jiao)(jiao)度(du)可(ke)用游(you)標萬能角(jiao)(jiao)度(du)尺采(cai)用透光法測(ce)(ce)量。角(jiao)(jiao)度(du)的誤差, 可(ke)用轉(zhuan)(zhuan)動(dong)工(gong)(gong)作(zuo)(zuo)臺,經(jing)過多(duo)次試切削和(he)測(ce)(ce)量來進行調整。 加(jia)工過程(cheng)中應(ying)注意以(yi)下細節保證兩(liang)錐(zhui)度同軸度: ( 1 ) 在直徑 100m m 處磨削找(zhao)正圓, 四爪單動卡盤裝夾找(zhao)正時用。 ( 2 ) 找(zhao)正(zheng)錐柄磨削工作錐面(mian)時(shi), 找(zhao)兩個點(dian), 其中一個點(dian)靠近(jin)卡盤爪, 另一個點(dian)在直徑 1 00 m m 處, 兩處誤差都(dou)應控制在0.0 1 m m 之內。 ( 3 ) 四爪(zhua)單動卡盤找(zhao)正(zheng)時, 找(zhao)正(zheng)的距離(li)應盡量短(duan)。 如果加工(gong)位置距(ju)離卡(ka)盤爪遠(yuan), 加工(gong)后誤(wu)差(cha)容易被放大,嚴重(zhong)時可(ke)能造成同軸度超差(cha)。 4. 加工時的注意事項 ( 1 ) 兩頂尖(jian)裝夾時需加潤滑脂, 并且轉(zhuan)速(su)不宜(yi)過高, 以(yi)免燒壞(huai)頂尖(jian)。 ( 2 ) 磨削(xue)時切削(xue)液要充分。 (3) 因磨削(xue)時要轉動砂輪架, 之前(qian)要修整(zheng)好砂輪。 ( 4 ) 磨60°工(gong)作(zuo)(zuo)錐(zhui)面(mian)時, 由于工(gong)作(zuo)(zuo)錐(zhui)面(mian)砂(sha)輪(lun)一側母線與工(gong)作(zuo)(zuo)臺(tai)導軌不(bu)(bu)平行(xing), 所以, 磨工(gong)作(zuo)(zuo)錐(zhui)面(mian)時不(bu)(bu)能機動走刀, 只(zhi)能手(shou)搖切入。移動工(gong)作(zuo)(zuo)臺(tai)對刀時要注意(yi)安全,小心工(gong)件(jian)不(bu)(bu)要與砂(sha)輪(lun)撞傷(shang)以防(fang)發生事故。 |