目前采用的(de)有三(san)種芯(xin)棒(bang)(bang)操作方式。早期(qi)的(de)三(san)輥軋管機均(jun)采用全浮(fu)芯(xin)棒(bang)(bang)，即使在(zai)今天，仍有一部分機組采用全浮(fu)芯(xin)棒(bang)(bang)操作。但是，全浮(fu)芯(xin)棒(bang)(bang)操作方式有如下缺點：

（1）軋制特厚壁管時不易(yi)脫棒；

（2）對各種尺寸的毛(mao)管(guan)均(jun)需要(yao)配置再加熱爐；

（3）軋制薄(bo)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(cao)作(zuo)方式的簡述(shu)。

1. 全浮芯棒

  采用(yong)全浮芯(xin)(xin)棒(bang)(bang)(bang)操作(zuo)方式時(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)被(bei)撥入(ru)(ru)到荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)前(qian)(qian)的(de)(de)人口臺(tai)，落到和軋(ya)(ya)(ya)機(ji)(ji)(ji)中(zhong)心線一致的(de)(de)U形槽里。氣(qi)動壓(ya)管(guan)(guan)(guan)(guan)(guan)(guan)器壓(ya)在(zai)(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)上，將(jiang)其夾緊，芯(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)將(jiang)芯(xin)(xin)棒(bang)(bang)(bang)穿入(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)內。一旦芯(xin)(xin)棒(bang)(bang)(bang)完全穿入(ru)(ru)，壓(ya)管(guan)(guan)(guan)(guan)(guan)(guan)器就(jiu)松(song)開，于是(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)連同芯(xin)(xin)棒(bang)(bang)(bang)一并(bing)向軋(ya)(ya)(ya)輥(gun)(gun)方向送去。如果荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)不(bu)易喂入(ru)(ru)軋(ya)(ya)(ya)機(ji)(ji)(ji)，就(jiu)用(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)在(zai)(zai)后(hou)(hou)面(mian)推(tui)(tui)(tui)下(xia)，以(yi)幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)喂入(ru)(ru)。當荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)開始軋(ya)(ya)(ya)制(zhi)時(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)和芯(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)便返回到初始位置。但是(shi)(shi)，當采用(yong)小(xiao)直徑芯(xin)(xin)棒(bang)(bang)(bang)軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)時(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)可保留在(zai)(zai)前(qian)(qian)位，充當導衛(wei)，防止芯(xin)(xin)棒(bang)(bang)(bang)抖動。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)延伸后(hou)(hou)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)和芯(xin)(xin)棒(bang)(bang)(bang)一起(qi)通過軋(ya)(ya)(ya)機(ji)(ji)(ji)向前(qian)(qian)移(yi)動軋(ya)(ya)(ya)制(zhi)終了時(shi)(shi)，后(hou)(hou)臺(tai)輥(gun)(gun)子升起(qi)，將(jiang)毛(mao)管(guan)(guan)(guan)(guan)(guan)(guan)及芯(xin)(xin)棒(bang)(bang)(bang)送到輸出(chu)輥(gun)(gun)道(dao)(dao)。然后(hou)(hou)，從輸出(chu)輥(gun)(gun)送到脫棒(bang)(bang)(bang)機(ji)(ji)(ji)，將(jiang)芯(xin)(xin)棒(bang)(bang)(bang)從毛(mao)管(guan)(guan)(guan)(guan)(guan)(guan)中(zhong)脫出(chu)。脫棒(bang)(bang)(bang)后(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)先冷卻，再(zai)送到軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)機(ji)(ji)(ji)前(qian)(qian)臺(tai)，以(yi)備再(zai)用(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)則由輥(gun)(gun)道(dao)(dao)送走，進行(xing)下(xia)一步(bu)加工。采用(yong)全浮棒(bang)(bang)(bang)操作(zuo)方式時(shi)(shi)，軋(ya)(ya)(ya)機(ji)(ji)(ji)生產率最高，因此，下(xia)一根芯(xin)(xin)棒(bang)(bang)(bang)的(de)(de)前(qian)(qian)端實際上可以(yi)跟在(zai)(zai)正在(zai)(zai)軋(ya)(ya)(ya)制(zhi)的(de)(de)前(qian)(qian)一根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)芯(xin)(xin)棒(bang)(bang)(bang)的(de)(de)后(hou)(hou)面(mian)。這是(shi)(shi)可能的(de)(de)，因為在(zai)(zai)前(qian)(qian)一根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)完以(yi)前(qian)(qian)，后(hou)(hou)一根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)可以(yi)放在(zai)(zai)前(qian)(qian)臺(tai)上、并(bing)穿好芯(xin)(xin)棒(bang)(bang)(bang)。

2. 回退芯棒

  回退芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方式(shi)(shi)和(he)浮動芯(xin)(xin)棒(bang)(bang)(bang)(bang)一樣使用同一荒(huang)管(guan)推(tui)(tui)人機(ji)(ji)(ji)與芯(xin)(xin)棒(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)，但(dan)是芯(xin)(xin)棒(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)上加(jia)了一套裝置，可將芯(xin)(xin)棒(bang)(bang)(bang)(bang)的(de)后(hou)(hou)(hou)端固定在芯(xin)(xin)棒(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)上并(bing)使芯(xin)(xin)棒(bang)(bang)(bang)(bang)回轉。荒(huang)管(guan)在前(qian)臺的(de)初始(shi)位(wei)置和(he)夾緊(jin)與全(quan)浮芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方式(shi)(shi)一樣。然(ran)而，在插入(ru)(ru)(ru)芯(xin)(xin)棒(bang)(bang)(bang)(bang)時(shi)，不(bu)僅(jin)芯(xin)(xin)棒(bang)(bang)(bang)(bang)頭(tou)部穿過荒(huang)管(guan)，而且芯(xin)(xin)棒(bang)(bang)(bang)(bang)要穿過軋(ya)機(ji)(ji)(ji)，伸出軋(ya)輥臺肩約3.5m。當芯(xin)(xin)棒(bang)(bang)(bang)(bang)到(dao)(dao)(dao)達此位(wei)置后(hou)(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)(kai)始(shi)回轉，直到(dao)(dao)(dao)荒(huang)管(guan)接觸軋(ya)輥后(hou)(hou)(hou)一段時(shi)間才停(ting)止。當芯(xin)(xin)棒(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)到(dao)(dao)(dao)達行程終點(dian)時(shi)，壓管(guan)器松開(kai)(kai)，荒(huang)管(guan)推(tui)(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)啟動前(qian)進。于是，荒(huang)管(guan)喂入(ru)(ru)(ru)軋(ya)機(ji)(ji)(ji)。軋(ya)制(zhi)開(kai)(kai)始(shi)后(hou)(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)(kai)始(shi)回退。其回退速(su)度(du)與荒(huang)管(guan)的(de)行程長度(du)及(ji)前(qian)進速(su)度(du)有關(guan)，以(yi)(yi)便在軋(ya)制(zhi)過程結束，當毛管(guan)離開(kai)(kai)軋(ya)輥時(shi)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)正好(hao)從荒(huang)管(guan)中抽出。見圖(tu)6-49。然(ran)后(hou)(hou)(hou)，毛管(guan)從軋(ya)機(ji)(ji)(ji)運走，進行下步加(jia)工，而芯(xin)(xin)棒(bang)(bang)(bang)(bang)高速(su)返回其初始(shi)位(wei)置以(yi)(yi)備穿入(ru)(ru)(ru)下一根毛管(guan)。

3. 限動芯(xin)棒

  限動(dong)芯(xin)棒(bang)(bang)操(cao)(cao)作(zuo)法(fa)是(shi)全浮(fu)芯(xin)棒(bang)(bang)和(he)回(hui)退(tui)芯(xin)棒(bang)(bang)操(cao)(cao)作(zuo)法(fa)的折中方法(fa)。采用(yong)這(zhe)種(zhong)方法(fa)時(shi)(shi)(shi)，芯(xin)棒(bang)(bang)的尾端固定在芯(xin)棒(bang)(bang)推(tui)入機(ji)上，并可回(hui)轉(zhuan)。這(zhe)和(he)回(hui)退(tui)芯(xin)棒(bang)(bang)操(cao)(cao)作(zuo)方式(shi)一樣，不同的是(shi)，鋼管軋(ya)制(zhi)時(shi)(shi)(shi)芯(xin)棒(bang)(bang)向(xiang)前(qian)(qian)移動(dong)。在軋(ya)制(zhi)結(jie)束(shu)時(shi)(shi)(shi)，芯(xin)棒(bang)(bang)從毛(mao)管上脫(tuo)出。當荒管在前(qian)(qian)臺被夾緊時(shi)(shi)(shi)，穿入芯(xin)棒(bang)(bang)，直到(dao)芯(xin)棒(bang)(bang)前(qian)(qian)端伸出軋(ya)輥(gun)臺肩約0.3m左右為止。插入芯(xin)棒(bang)(bang)時(shi)(shi)(shi)，芯(xin)棒(bang)(bang)開始回(hui)轉(zhuan)，直到(dao)荒管接觸軋(ya)輥(gun)后(hou)一段時(shi)(shi)(shi)間才停止。芯(xin)棒(bang)(bang)到(dao)位(wei)后(hou)，壓管器(qi)松開，荒管推(tui)入機(ji)將荒管推(tui)向(xiang)軋(ya)輥(gun)，直到(dao)軋(ya)制(zhi)過程(cheng)開始為止。軋(ya)制(zhi)過程(cheng)中，芯(xin)捧以(yi)低于毛(mao)管軸向(xiang)輸出速度的速度和(he)軋(ya)件一起前(qian)(qian)進。軋(ya)制(zhi)周期結(jie)束(shu)時(shi)(shi)(shi)，毛(mao)管從芯(xin)棒(bang)(bang)上脫(tuo)出，然后(hou)，芯(xin)棒(bang)(bang)高速返回(hui)其初始位(wei)置。

  三(san)種芯(xin)(xin)棒(bang)(bang)操作(zuo)方式(shi)(shi)的比較。在采(cai)(cai)用(yong)回退芯(xin)(xin)棒(bang)(bang)與限(xian)動(dong)芯(xin)(xin)棒(bang)(bang)操作(zuo)方式(shi)(shi)的工廠(chang)，只有生(sheng)產D/t小(xiao)于7.5的鋼管時才采(cai)(cai)用(yong)回退芯(xin)(xin)棒(bang)(bang)操作(zuo)方式(shi)(shi)，而當生(sheng)產D/t大于7.5的鋼管時采(cai)(cai)用(yong)限(xian)動(dong)芯(xin)(xin)棒(bang)(bang)操作(zuo)方式(shi)(shi)。顯然(ran)，采(cai)(cai)用(yong)回退和(he)限(xian)動(dong)芯(xin)(xin)棒(bang)(bang)操作(zuo)方式(shi)(shi)時，軋機產量比采(cai)(cai)用(yong)全浮芯(xin)(xin)棒(bang)(bang)時低，因為，下(xia)一(yi)根荒管撥入到前臺(tai)之前，在用(yong)的芯(xin)(xin)棒(bang)(bang)必須返回其初始位置。同(tong)時，芯(xin)(xin)棒(bang)(bang)的冷卻不(bu)充分，芯(xin)(xin)棒(bang)(bang)壽命不(bu)長。