目(mu)前(qian)采用(yong)的有三(san)種芯(xin)(xin)棒操(cao)作方式(shi)。早期的三(san)輥軋管機均(jun)采用(yong)全(quan)浮芯(xin)(xin)棒，即使(shi)在今天，仍有一部分機組采用(yong)全(quan)浮芯(xin)(xin)棒操(cao)作。但是，全(quan)浮芯(xin)(xin)棒操(cao)作方式(shi)有如(ru)下(xia)缺點：
（1）軋制特厚壁管時不易脫棒；
（2）對各種尺寸的毛管均需要配(pei)置再加(jia)熱爐；
（3）軋制薄壁管時易產生的金屬扭曲和表面缺陷。由于存在上述問題導致限動芯棒和回退芯棒操作方式的開發。
以下(xia)是三種(zhong)不同芯棒操作方式的簡述(shu)。
1. 全浮芯棒(bang)
采用(yong)全浮芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)(cao)作(zuo)方式時，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)被(bei)撥入到荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入機(ji)(ji)(ji)前(qian)(qian)(qian)(qian)的人(ren)口(kou)臺(tai)，落(luo)到和軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)中(zhong)心線一致的U形槽里。氣動壓(ya)管(guan)(guan)(guan)(guan)器壓(ya)在(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)上，將(jiang)其夾緊(jin)，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)入機(ji)(ji)(ji)將(jiang)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)穿入荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)內。一旦芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)完(wan)(wan)全穿入，壓(ya)管(guan)(guan)(guan)(guan)器就松開，于是(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)連(lian)同芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)一并向軋(ya)(ya)(ya)(ya)輥方向送(song)去。如果荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)不易喂入軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)，就用(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入機(ji)(ji)(ji)在(zai)后(hou)(hou)面推(tui)(tui)(tui)下，以(yi)幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)喂入。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)開始軋(ya)(ya)(ya)(ya)制時，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入機(ji)(ji)(ji)和芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)入機(ji)(ji)(ji)便返回(hui)到初始位(wei)置。但是(shi)(shi)，當(dang)采用(yong)小直徑芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)時，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入機(ji)(ji)(ji)可(ke)保留(liu)在(zai)前(qian)(qian)(qian)(qian)位(wei)，充當(dang)導(dao)衛，防(fang)止芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)抖動。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)延(yan)伸后(hou)(hou)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)和芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)一起通過軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)向前(qian)(qian)(qian)(qian)移(yi)動軋(ya)(ya)(ya)(ya)制終了時，后(hou)(hou)臺(tai)輥子升起，將(jiang)毛管(guan)(guan)(guan)(guan)及(ji)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)送(song)到輸出輥道。然后(hou)(hou)，從輸出輥送(song)到脫棒(bang)(bang)(bang)機(ji)(ji)(ji)，將(jiang)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)從毛管(guan)(guan)(guan)(guan)中(zhong)脫出。脫棒(bang)(bang)(bang)后(hou)(hou)，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)先冷卻(que)，再(zai)送(song)到軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)機(ji)(ji)(ji)前(qian)(qian)(qian)(qian)臺(tai)，以(yi)備再(zai)用(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)則由輥道送(song)走，進行下一步加(jia)工。采用(yong)全浮棒(bang)(bang)(bang)操(cao)(cao)作(zuo)方式時，軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)生產率最高，因(yin)此，下一根(gen)(gen)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的前(qian)(qian)(qian)(qian)端實際上可(ke)以(yi)跟在(zai)正在(zai)軋(ya)(ya)(ya)(ya)制的前(qian)(qian)(qian)(qian)一根(gen)(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)的芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的后(hou)(hou)面。這是(shi)(shi)可(ke)能的，因(yin)為在(zai)前(qian)(qian)(qian)(qian)一根(gen)(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)完(wan)(wan)以(yi)前(qian)(qian)(qian)(qian)，后(hou)(hou)一根(gen)(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)可(ke)以(yi)放在(zai)前(qian)(qian)(qian)(qian)臺(tai)上、并穿好芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)。
2. 回(hui)退(tui)芯棒
回(hui)(hui)退芯(xin)棒(bang)(bang)(bang)(bang)操作方(fang)式(shi)和(he)浮動芯(xin)棒(bang)(bang)(bang)(bang)一(yi)(yi)樣(yang)使(shi)(shi)用同一(yi)(yi)荒(huang)(huang)管(guan)推人機(ji)與芯(xin)棒(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)，但是芯(xin)棒(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)上加(jia)了一(yi)(yi)套裝(zhuang)置，可將芯(xin)棒(bang)(bang)(bang)(bang)的(de)后端固定在(zai)(zai)芯(xin)棒(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)上并使(shi)(shi)芯(xin)棒(bang)(bang)(bang)(bang)回(hui)(hui)轉(zhuan)。荒(huang)(huang)管(guan)在(zai)(zai)前(qian)臺的(de)初始(shi)位置和(he)夾緊(jin)與全浮芯(xin)棒(bang)(bang)(bang)(bang)操作方(fang)式(shi)一(yi)(yi)樣(yang)。然(ran)而(er)，在(zai)(zai)插入(ru)(ru)(ru)芯(xin)棒(bang)(bang)(bang)(bang)時(shi)，不(bu)僅芯(xin)棒(bang)(bang)(bang)(bang)頭部穿過(guo)荒(huang)(huang)管(guan)，而(er)且芯(xin)棒(bang)(bang)(bang)(bang)要(yao)穿過(guo)軋(ya)機(ji)，伸出軋(ya)輥臺肩約3.5m。當(dang)芯(xin)棒(bang)(bang)(bang)(bang)到(dao)(dao)達此位置后，芯(xin)棒(bang)(bang)(bang)(bang)開始(shi)回(hui)(hui)轉(zhuan)，直(zhi)到(dao)(dao)荒(huang)(huang)管(guan)接觸軋(ya)輥后一(yi)(yi)段時(shi)間才停止。當(dang)芯(xin)棒(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)到(dao)(dao)達行程(cheng)終點時(shi)，壓管(guan)器(qi)松開，荒(huang)(huang)管(guan)推入(ru)(ru)(ru)機(ji)啟動前(qian)進(jin)(jin)。于是，荒(huang)(huang)管(guan)喂入(ru)(ru)(ru)軋(ya)機(ji)。軋(ya)制開始(shi)后，芯(xin)棒(bang)(bang)(bang)(bang)開始(shi)回(hui)(hui)退。其回(hui)(hui)退速(su)度(du)與荒(huang)(huang)管(guan)的(de)行程(cheng)長度(du)及前(qian)進(jin)(jin)速(su)度(du)有關(guan)，以便在(zai)(zai)軋(ya)制過(guo)程(cheng)結束，當(dang)毛(mao)管(guan)離開軋(ya)輥時(shi)，芯(xin)棒(bang)(bang)(bang)(bang)正(zheng)好從(cong)荒(huang)(huang)管(guan)中抽(chou)出。見圖(tu)6-49。然(ran)后，毛(mao)管(guan)從(cong)軋(ya)機(ji)運(yun)走，進(jin)(jin)行下步加(jia)工(gong)，而(er)芯(xin)棒(bang)(bang)(bang)(bang)高速(su)返(fan)回(hui)(hui)其初始(shi)位置以備穿入(ru)(ru)(ru)下一(yi)(yi)根毛(mao)管(guan)。
3. 限動芯棒(bang)
限動芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操作法是(shi)全浮芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)和(he)(he)回(hui)(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操作法的(de)折中方法。采用這種方法時(shi)(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)的(de)尾端(duan)固定在芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)推(tui)入機(ji)上，并可回(hui)(hui)轉。這和(he)(he)回(hui)(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操作方式一樣(yang)，不同的(de)是(shi)，鋼管(guan)軋(ya)(ya)(ya)(ya)制(zhi)時(shi)(shi)(shi)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)向前移動。在軋(ya)(ya)(ya)(ya)制(zhi)結束時(shi)(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)從毛(mao)管(guan)上脫(tuo)出。當荒管(guan)在前臺被夾緊時(shi)(shi)(shi)，穿入芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)，直(zhi)(zhi)到芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)前端(duan)伸出軋(ya)(ya)(ya)(ya)輥臺肩約0.3m左右為止。插入芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)時(shi)(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)開(kai)始(shi)回(hui)(hui)轉，直(zhi)(zhi)到荒管(guan)接觸軋(ya)(ya)(ya)(ya)輥后一段時(shi)(shi)(shi)間(jian)才停止。芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)到位后，壓管(guan)器(qi)松開(kai)，荒管(guan)推(tui)入機(ji)將(jiang)荒管(guan)推(tui)向軋(ya)(ya)(ya)(ya)輥，直(zhi)(zhi)到軋(ya)(ya)(ya)(ya)制(zhi)過程開(kai)始(shi)為止。軋(ya)(ya)(ya)(ya)制(zhi)過程中，芯(xin)(xin)(xin)捧以低于毛(mao)管(guan)軸向輸出速度(du)的(de)速度(du)和(he)(he)軋(ya)(ya)(ya)(ya)件一起前進。軋(ya)(ya)(ya)(ya)制(zhi)周期結束時(shi)(shi)(shi)，毛(mao)管(guan)從芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)上脫(tuo)出，然后，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)高速返回(hui)(hui)其初始(shi)位置。
三種(zhong)芯(xin)(xin)棒(bang)操作(zuo)方式的(de)(de)比(bi)(bi)較。在(zai)采(cai)用回退(tui)芯(xin)(xin)棒(bang)與限動(dong)(dong)芯(xin)(xin)棒(bang)操作(zuo)方式的(de)(de)工廠，只有生(sheng)(sheng)產D/t小于7.5的(de)(de)鋼(gang)管(guan)時才采(cai)用回退(tui)芯(xin)(xin)棒(bang)操作(zuo)方式，而當生(sheng)(sheng)產D/t大于7.5的(de)(de)鋼(gang)管(guan)時采(cai)用限動(dong)(dong)芯(xin)(xin)棒(bang)操作(zuo)方式。顯然，采(cai)用回退(tui)和限動(dong)(dong)芯(xin)(xin)棒(bang)操作(zuo)方式時，軋(ya)機產量比(bi)(bi)采(cai)用全浮(fu)芯(xin)(xin)棒(bang)時低，因為，下一根荒管(guan)撥入到前(qian)臺(tai)之前(qian)，在(zai)用的(de)(de)芯(xin)(xin)棒(bang)必(bi)須返回其初始位置。同時，芯(xin)(xin)棒(bang)的(de)(de)冷(leng)卻不充分，芯(xin)(xin)棒(bang)壽命不長。
