目前采用(yong)的有(you)(you)三種芯(xin)棒(bang)(bang)操作方式。早期的三輥軋管機均采用(yong)全浮(fu)(fu)芯(xin)棒(bang)(bang)，即使在今(jin)天，仍有(you)(you)一部分機組采用(yong)全浮(fu)(fu)芯(xin)棒(bang)(bang)操作。但是，全浮(fu)(fu)芯(xin)棒(bang)(bang)操作方式有(you)(you)如下(xia)缺點：

（1）軋制特厚壁管時不易脫棒(bang)；

（2）對(dui)各(ge)種(zhong)尺(chi)寸的毛管(guan)均需要(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(shi)三(san)種不同芯棒操作方式的簡述。

1. 全浮芯棒

  采(cai)(cai)用(yong)(yong)全浮(fu)芯(xin)棒(bang)(bang)操作(zuo)方式時(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)被撥入(ru)(ru)(ru)(ru)到(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)前(qian)(qian)的人(ren)口臺，落到(dao)和(he)(he)軋(ya)(ya)(ya)機(ji)(ji)(ji)中心線一致的U形槽(cao)里。氣動壓(ya)管(guan)(guan)(guan)(guan)器(qi)壓(ya)在(zai)(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)上，將(jiang)其夾(jia)緊，芯(xin)棒(bang)(bang)推(tui)(tui)(tui)入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)將(jiang)芯(xin)棒(bang)(bang)穿入(ru)(ru)(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)內。一旦(dan)芯(xin)棒(bang)(bang)完全穿入(ru)(ru)(ru)(ru)，壓(ya)管(guan)(guan)(guan)(guan)器(qi)就(jiu)松開，于是(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)連同芯(xin)棒(bang)(bang)一并(bing)向軋(ya)(ya)(ya)輥(gun)(gun)方向送(song)去(qu)。如果(guo)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)不易(yi)喂入(ru)(ru)(ru)(ru)軋(ya)(ya)(ya)機(ji)(ji)(ji)，就(jiu)用(yong)(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)在(zai)(zai)后面推(tui)(tui)(tui)下，以幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)喂入(ru)(ru)(ru)(ru)。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)開始軋(ya)(ya)(ya)制(zhi)時(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)和(he)(he)芯(xin)棒(bang)(bang)推(tui)(tui)(tui)入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)便返回(hui)到(dao)初始位(wei)(wei)置。但是(shi)，當(dang)采(cai)(cai)用(yong)(yong)小直徑芯(xin)棒(bang)(bang)軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)時(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)(tui)入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)可保留(liu)在(zai)(zai)前(qian)(qian)位(wei)(wei)，充當(dang)導衛，防止芯(xin)棒(bang)(bang)抖動。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)延(yan)伸后，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)和(he)(he)芯(xin)棒(bang)(bang)一起(qi)通過軋(ya)(ya)(ya)機(ji)(ji)(ji)向前(qian)(qian)移動軋(ya)(ya)(ya)制(zhi)終了時(shi)(shi)，后臺輥(gun)(gun)子升起(qi)，將(jiang)毛管(guan)(guan)(guan)(guan)及芯(xin)棒(bang)(bang)送(song)到(dao)輸出輥(gun)(gun)道。然后，從輸出輥(gun)(gun)送(song)到(dao)脫棒(bang)(bang)機(ji)(ji)(ji)，將(jiang)芯(xin)棒(bang)(bang)從毛管(guan)(guan)(guan)(guan)中脫出。脫棒(bang)(bang)后，芯(xin)棒(bang)(bang)先冷卻，再送(song)到(dao)軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)機(ji)(ji)(ji)前(qian)(qian)臺，以備再用(yong)(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)則由輥(gun)(gun)道送(song)走，進行下一步加工。采(cai)(cai)用(yong)(yong)全浮(fu)棒(bang)(bang)操作(zuo)方式時(shi)(shi)，軋(ya)(ya)(ya)機(ji)(ji)(ji)生(sheng)產率最高，因(yin)此，下一根芯(xin)棒(bang)(bang)的前(qian)(qian)端實際上可以跟(gen)在(zai)(zai)正在(zai)(zai)軋(ya)(ya)(ya)制(zhi)的前(qian)(qian)一根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)的芯(xin)棒(bang)(bang)的后面。這(zhe)是(shi)可能的，因(yin)為(wei)在(zai)(zai)前(qian)(qian)一根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)完以前(qian)(qian)，后一根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)可以放在(zai)(zai)前(qian)(qian)臺上、并(bing)穿好芯(xin)棒(bang)(bang)。

2. 回退(tui)芯(xin)棒

  回(hui)退芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操作方式和(he)浮(fu)(fu)動芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)一(yi)樣(yang)使(shi)用同一(yi)荒管推(tui)人(ren)機(ji)(ji)與(yu)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入機(ji)(ji)，但是芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入機(ji)(ji)上加了一(yi)套裝置(zhi)(zhi)，可(ke)將(jiang)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的后(hou)端固定在(zai)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入機(ji)(ji)上并使(shi)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)回(hui)轉(zhuan)。荒管在(zai)前臺的初始(shi)位置(zhi)(zhi)和(he)夾緊與(yu)全浮(fu)(fu)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操作方式一(yi)樣(yang)。然(ran)而(er)，在(zai)插入芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時(shi)，不僅(jin)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)頭部穿(chuan)過荒管，而(er)且(qie)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)要穿(chuan)過軋(ya)(ya)機(ji)(ji)，伸出(chu)軋(ya)(ya)輥(gun)臺肩(jian)約3.5m。當(dang)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到達此位置(zhi)(zhi)后(hou)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開(kai)始(shi)回(hui)轉(zhuan)，直到荒管接(jie)觸軋(ya)(ya)輥(gun)后(hou)一(yi)段時(shi)間才(cai)停止。當(dang)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入機(ji)(ji)到達行程(cheng)終(zhong)點時(shi)，壓管器(qi)松開(kai)，荒管推(tui)入機(ji)(ji)啟動前進(jin)。于是，荒管喂(wei)入軋(ya)(ya)機(ji)(ji)。軋(ya)(ya)制開(kai)始(shi)后(hou)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開(kai)始(shi)回(hui)退。其(qi)回(hui)退速度與(yu)荒管的行程(cheng)長度及前進(jin)速度有關(guan)，以便在(zai)軋(ya)(ya)制過程(cheng)結束，當(dang)毛(mao)管離開(kai)軋(ya)(ya)輥(gun)時(shi)，芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)正好從荒管中抽出(chu)。見圖6-49。然(ran)后(hou)，毛(mao)管從軋(ya)(ya)機(ji)(ji)運走，進(jin)行下步加工(gong)，而(er)芯(xin)(xin)(xin)(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速返回(hui)其(qi)初始(shi)位置(zhi)(zhi)以備(bei)穿(chuan)入下一(yi)根毛(mao)管。

3. 限動芯棒

  限動芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操(cao)作法(fa)是全浮芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)和回(hui)(hui)(hui)退芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操(cao)作法(fa)的(de)折(zhe)中方法(fa)。采用這(zhe)種方法(fa)時(shi)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)尾端固定在芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)機(ji)(ji)上，并可回(hui)(hui)(hui)轉(zhuan)。這(zhe)和回(hui)(hui)(hui)退芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操(cao)作方式一(yi)(yi)樣，不同的(de)是，鋼管(guan)(guan)軋(ya)制(zhi)時(shi)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)向前移動。在軋(ya)制(zhi)結(jie)束(shu)時(shi)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)從毛管(guan)(guan)上脫出(chu)。當荒(huang)(huang)管(guan)(guan)在前臺被(bei)夾(jia)緊時(shi)，穿(chuan)入(ru)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)，直到(dao)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)前端伸出(chu)軋(ya)輥(gun)臺肩(jian)約0.3m左右為止。插入(ru)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)時(shi)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開始(shi)回(hui)(hui)(hui)轉(zhuan)，直到(dao)荒(huang)(huang)管(guan)(guan)接觸軋(ya)輥(gun)后一(yi)(yi)段(duan)時(shi)間才(cai)停(ting)止。芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)到(dao)位后，壓管(guan)(guan)器松開，荒(huang)(huang)管(guan)(guan)推(tui)入(ru)機(ji)(ji)將荒(huang)(huang)管(guan)(guan)推(tui)向軋(ya)輥(gun)，直到(dao)軋(ya)制(zhi)過程開始(shi)為止。軋(ya)制(zhi)過程中，芯(xin)(xin)捧(peng)以低于毛管(guan)(guan)軸向輸出(chu)速度的(de)速度和軋(ya)件一(yi)(yi)起前進。軋(ya)制(zhi)周期結(jie)束(shu)時(shi)，毛管(guan)(guan)從芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)上脫出(chu)，然后，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)高速返回(hui)(hui)(hui)其初始(shi)位置。

  三種芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)(fang)式(shi)的(de)比(bi)(bi)較。在(zai)采(cai)用回退(tui)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)與限(xian)動芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)(fang)式(shi)的(de)工廠，只有生(sheng)產(chan)D/t小于(yu)7.5的(de)鋼管(guan)時才采(cai)用回退(tui)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)(fang)式(shi)，而當生(sheng)產(chan)D/t大于(yu)7.5的(de)鋼管(guan)時采(cai)用限(xian)動芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)(fang)式(shi)。顯然，采(cai)用回退(tui)和限(xian)動芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)(fang)式(shi)時，軋機產(chan)量比(bi)(bi)采(cai)用全浮芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)時低，因為(wei)，下一根荒管(guan)撥入到前臺之前，在(zai)用的(de)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)必須(xu)返回其初始位置。同時，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的(de)冷卻不(bu)充分(fen)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)壽命(ming)不(bu)長。