目前采用的有三(san)種芯(xin)(xin)(xin)棒(bang)(bang)操作方式(shi)。早期(qi)的三(san)輥(gun)軋管機均(jun)采用全浮芯(xin)(xin)(xin)棒(bang)(bang)，即使在今(jin)天，仍有一部分機組采用全浮芯(xin)(xin)(xin)棒(bang)(bang)操作。但是(shi)，全浮芯(xin)(xin)(xin)棒(bang)(bang)操作方式(shi)有如下缺點：

（1）軋制特厚壁管(guan)時不易脫棒；

（2）對各種尺寸的毛管均需要配置(zhi)再加熱(re)爐；

（3）軋制薄壁管(guan)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(yi)下是三種不同芯棒操作(zuo)方(fang)式的簡述(shu)。

1. 全(quan)浮芯棒

  采(cai)用全浮芯(xin)(xin)棒(bang)(bang)操作(zuo)方(fang)式(shi)(shi)時(shi)，荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)被撥入(ru)(ru)到(dao)(dao)荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)(ji)(ji)前(qian)(qian)的(de)(de)人口臺，落(luo)到(dao)(dao)和(he)(he)軋(ya)(ya)機(ji)(ji)(ji)(ji)(ji)中心線(xian)一(yi)(yi)(yi)致的(de)(de)U形槽里(li)。氣(qi)動(dong)壓(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)器壓(ya)(ya)在荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)上，將(jiang)其夾緊，芯(xin)(xin)棒(bang)(bang)推(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)(ji)(ji)將(jiang)芯(xin)(xin)棒(bang)(bang)穿入(ru)(ru)荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)內。一(yi)(yi)(yi)旦(dan)芯(xin)(xin)棒(bang)(bang)完(wan)全穿入(ru)(ru)，壓(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)器就松開(kai)(kai)，于是(shi)，荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)連同芯(xin)(xin)棒(bang)(bang)一(yi)(yi)(yi)并(bing)向軋(ya)(ya)輥(gun)方(fang)向送(song)(song)去。如(ru)果荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)不易喂入(ru)(ru)軋(ya)(ya)機(ji)(ji)(ji)(ji)(ji)，就用荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)(ji)(ji)在后(hou)面推(tui)(tui)下，以(yi)幫助荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)喂入(ru)(ru)。當(dang)荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)開(kai)(kai)始軋(ya)(ya)制時(shi)，荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)(ji)(ji)和(he)(he)芯(xin)(xin)棒(bang)(bang)推(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)(ji)(ji)便返回到(dao)(dao)初始位置。但是(shi)，當(dang)采(cai)用小直(zhi)徑芯(xin)(xin)棒(bang)(bang)軋(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)(ji)(ji)(ji)可(ke)保留在前(qian)(qian)位，充(chong)當(dang)導衛，防止芯(xin)(xin)棒(bang)(bang)抖(dou)動(dong)。荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)延伸后(hou)，荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)和(he)(he)芯(xin)(xin)棒(bang)(bang)一(yi)(yi)(yi)起通過軋(ya)(ya)機(ji)(ji)(ji)(ji)(ji)向前(qian)(qian)移(yi)動(dong)軋(ya)(ya)制終(zhong)了時(shi)，后(hou)臺輥(gun)子升(sheng)起，將(jiang)毛管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)及芯(xin)(xin)棒(bang)(bang)送(song)(song)到(dao)(dao)輸出輥(gun)道。然后(hou)，從輸出輥(gun)送(song)(song)到(dao)(dao)脫(tuo)(tuo)棒(bang)(bang)機(ji)(ji)(ji)(ji)(ji)，將(jiang)芯(xin)(xin)棒(bang)(bang)從毛管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)中脫(tuo)(tuo)出。脫(tuo)(tuo)棒(bang)(bang)后(hou)，芯(xin)(xin)棒(bang)(bang)先冷卻，再(zai)(zai)送(song)(song)到(dao)(dao)軋(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)機(ji)(ji)(ji)(ji)(ji)前(qian)(qian)臺，以(yi)備再(zai)(zai)用。荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)則由輥(gun)道送(song)(song)走，進行下一(yi)(yi)(yi)步加工(gong)。采(cai)用全浮棒(bang)(bang)操作(zuo)方(fang)式(shi)(shi)時(shi)，軋(ya)(ya)機(ji)(ji)(ji)(ji)(ji)生產率最高，因此，下一(yi)(yi)(yi)根芯(xin)(xin)棒(bang)(bang)的(de)(de)前(qian)(qian)端實際上可(ke)以(yi)跟在正在軋(ya)(ya)制的(de)(de)前(qian)(qian)一(yi)(yi)(yi)根荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)芯(xin)(xin)棒(bang)(bang)的(de)(de)后(hou)面。這是(shi)可(ke)能(neng)的(de)(de)，因為在前(qian)(qian)一(yi)(yi)(yi)根荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)軋(ya)(ya)完(wan)以(yi)前(qian)(qian)，后(hou)一(yi)(yi)(yi)根荒(huang)(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)可(ke)以(yi)放在前(qian)(qian)臺上、并(bing)穿好(hao)芯(xin)(xin)棒(bang)(bang)。

2. 回(hui)退芯(xin)棒

  回(hui)退(tui)芯棒(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式和(he)浮動芯棒(bang)(bang)(bang)(bang)(bang)一(yi)(yi)樣使(shi)用(yong)同(tong)一(yi)(yi)荒(huang)(huang)(huang)管(guan)(guan)推人機(ji)與(yu)芯棒(bang)(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)，但是(shi)芯棒(bang)(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)上加(jia)(jia)了(le)一(yi)(yi)套裝置(zhi)(zhi)(zhi)，可將芯棒(bang)(bang)(bang)(bang)(bang)的(de)后(hou)(hou)端固(gu)定在芯棒(bang)(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)上并使(shi)芯棒(bang)(bang)(bang)(bang)(bang)回(hui)轉(zhuan)(zhuan)。荒(huang)(huang)(huang)管(guan)(guan)在前(qian)臺的(de)初始(shi)(shi)(shi)(shi)位(wei)(wei)置(zhi)(zhi)(zhi)和(he)夾緊與(yu)全浮芯棒(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式一(yi)(yi)樣。然而，在插入(ru)(ru)(ru)芯棒(bang)(bang)(bang)(bang)(bang)時(shi)(shi)(shi)，不僅芯棒(bang)(bang)(bang)(bang)(bang)頭部穿(chuan)過荒(huang)(huang)(huang)管(guan)(guan)，而且芯棒(bang)(bang)(bang)(bang)(bang)要(yao)穿(chuan)過軋(ya)(ya)機(ji)，伸出軋(ya)(ya)輥臺肩約3.5m。當(dang)芯棒(bang)(bang)(bang)(bang)(bang)到(dao)(dao)達(da)此位(wei)(wei)置(zhi)(zhi)(zhi)后(hou)(hou)，芯棒(bang)(bang)(bang)(bang)(bang)開始(shi)(shi)(shi)(shi)回(hui)轉(zhuan)(zhuan)，直到(dao)(dao)荒(huang)(huang)(huang)管(guan)(guan)接觸軋(ya)(ya)輥后(hou)(hou)一(yi)(yi)段時(shi)(shi)(shi)間才停止(zhi)。當(dang)芯棒(bang)(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)到(dao)(dao)達(da)行程終(zhong)點時(shi)(shi)(shi)，壓管(guan)(guan)器(qi)松(song)開，荒(huang)(huang)(huang)管(guan)(guan)推入(ru)(ru)(ru)機(ji)啟動前(qian)進(jin)。于是(shi)，荒(huang)(huang)(huang)管(guan)(guan)喂(wei)入(ru)(ru)(ru)軋(ya)(ya)機(ji)。軋(ya)(ya)制(zhi)開始(shi)(shi)(shi)(shi)后(hou)(hou)，芯棒(bang)(bang)(bang)(bang)(bang)開始(shi)(shi)(shi)(shi)回(hui)退(tui)。其(qi)回(hui)退(tui)速(su)度與(yu)荒(huang)(huang)(huang)管(guan)(guan)的(de)行程長度及前(qian)進(jin)速(su)度有關(guan)，以便在軋(ya)(ya)制(zhi)過程結(jie)束，當(dang)毛管(guan)(guan)離開軋(ya)(ya)輥時(shi)(shi)(shi)，芯棒(bang)(bang)(bang)(bang)(bang)正好(hao)從荒(huang)(huang)(huang)管(guan)(guan)中抽出。見(jian)圖6-49。然后(hou)(hou)，毛管(guan)(guan)從軋(ya)(ya)機(ji)運走，進(jin)行下步加(jia)(jia)工，而芯棒(bang)(bang)(bang)(bang)(bang)高(gao)速(su)返回(hui)其(qi)初始(shi)(shi)(shi)(shi)位(wei)(wei)置(zhi)(zhi)(zhi)以備(bei)穿(chuan)入(ru)(ru)(ru)下一(yi)(yi)根毛管(guan)(guan)。

3. 限動芯棒

  限動(dong)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)法(fa)是全(quan)浮(fu)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)和回(hui)退(tui)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)法(fa)的折中(zhong)方(fang)法(fa)。采用這種方(fang)法(fa)時(shi)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的尾端(duan)固定在(zai)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)機上，并可(ke)回(hui)轉。這和回(hui)退(tui)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)方(fang)式一樣，不同的是，鋼管(guan)(guan)軋(ya)(ya)制時(shi)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)向(xiang)前(qian)移動(dong)。在(zai)軋(ya)(ya)制結束時(shi)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)從毛(mao)管(guan)(guan)上脫(tuo)出(chu)(chu)(chu)。當荒(huang)管(guan)(guan)在(zai)前(qian)臺(tai)被夾緊時(shi)，穿入(ru)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)，直到芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)前(qian)端(duan)伸出(chu)(chu)(chu)軋(ya)(ya)輥(gun)臺(tai)肩約(yue)0.3m左(zuo)右為止(zhi)。插入(ru)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時(shi)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開始(shi)(shi)回(hui)轉，直到荒(huang)管(guan)(guan)接觸軋(ya)(ya)輥(gun)后一段(duan)時(shi)間才(cai)停止(zhi)。芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到位后，壓管(guan)(guan)器松開，荒(huang)管(guan)(guan)推(tui)入(ru)機將荒(huang)管(guan)(guan)推(tui)向(xiang)軋(ya)(ya)輥(gun)，直到軋(ya)(ya)制過程(cheng)開始(shi)(shi)為止(zhi)。軋(ya)(ya)制過程(cheng)中(zhong)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)捧以低于毛(mao)管(guan)(guan)軸向(xiang)輸出(chu)(chu)(chu)速(su)度(du)的速(su)度(du)和軋(ya)(ya)件一起前(qian)進(jin)。軋(ya)(ya)制周期結束時(shi)，毛(mao)管(guan)(guan)從芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)上脫(tuo)出(chu)(chu)(chu)，然后，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高(gao)速(su)返回(hui)其初(chu)始(shi)(shi)位置。

  三(san)種芯(xin)(xin)棒(bang)操(cao)作(zuo)方(fang)式的(de)比較。在(zai)采用(yong)回(hui)退芯(xin)(xin)棒(bang)與限動(dong)芯(xin)(xin)棒(bang)操(cao)作(zuo)方(fang)式的(de)工廠，只有生產(chan)D/t小于7.5的(de)鋼管(guan)(guan)時(shi)才(cai)采用(yong)回(hui)退芯(xin)(xin)棒(bang)操(cao)作(zuo)方(fang)式，而當生產(chan)D/t大于7.5的(de)鋼管(guan)(guan)時(shi)采用(yong)限動(dong)芯(xin)(xin)棒(bang)操(cao)作(zuo)方(fang)式。顯然，采用(yong)回(hui)退和限動(dong)芯(xin)(xin)棒(bang)操(cao)作(zuo)方(fang)式時(shi)，軋機產(chan)量比采用(yong)全浮芯(xin)(xin)棒(bang)時(shi)低，因為，下一根荒管(guan)(guan)撥入(ru)到前臺(tai)之(zhi)前，在(zai)用(yong)的(de)芯(xin)(xin)棒(bang)必(bi)須返回(hui)其初始位置。同(tong)時(shi)，芯(xin)(xin)棒(bang)的(de)冷卻不充分，芯(xin)(xin)棒(bang)壽命不長。