目前采用的(de)有三(san)種芯(xin)棒(bang)(bang)操(cao)作(zuo)方(fang)式。早(zao)期的(de)三(san)輥軋管機均(jun)采用全(quan)浮芯(xin)棒(bang)(bang)，即使(shi)在(zai)今(jin)天，仍有一部分機組采用全(quan)浮芯(xin)棒(bang)(bang)操(cao)作(zuo)。但是(shi)，全(quan)浮芯(xin)棒(bang)(bang)操(cao)作(zuo)方(fang)式有如下(xia)缺點：

（1）軋制特厚壁管時(shi)不易脫棒；

（2）對各(ge)種尺(chi)寸的(de)毛管(guan)均需要配置再加熱(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。

以下是三種不同芯棒(bang)操作方式的簡述。

1. 全浮芯棒

  采(cai)用(yong)(yong)(yong)全浮(fu)芯棒(bang)(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)被撥入(ru)(ru)(ru)到(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機前(qian)(qian)的(de)(de)人口臺，落到(dao)和(he)軋(ya)(ya)(ya)(ya)機中(zhong)心線一(yi)(yi)(yi)致的(de)(de)U形槽(cao)里。氣動壓(ya)管(guan)(guan)(guan)(guan)器壓(ya)在荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)上(shang)，將(jiang)其(qi)夾緊，芯棒(bang)(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機將(jiang)芯棒(bang)(bang)(bang)(bang)(bang)(bang)穿入(ru)(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)內。一(yi)(yi)(yi)旦芯棒(bang)(bang)(bang)(bang)(bang)(bang)完全穿入(ru)(ru)(ru)，壓(ya)管(guan)(guan)(guan)(guan)器就(jiu)松開，于是，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)連同(tong)芯棒(bang)(bang)(bang)(bang)(bang)(bang)一(yi)(yi)(yi)并向(xiang)軋(ya)(ya)(ya)(ya)輥(gun)(gun)方(fang)向(xiang)送(song)去。如果荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)不易喂入(ru)(ru)(ru)軋(ya)(ya)(ya)(ya)機，就(jiu)用(yong)(yong)(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機在后面推(tui)下，以幫(bang)助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)喂入(ru)(ru)(ru)。當荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)開始(shi)軋(ya)(ya)(ya)(ya)制(zhi)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機和(he)芯棒(bang)(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機便返回到(dao)初始(shi)位(wei)置。但是，當采(cai)用(yong)(yong)(yong)小直(zhi)徑芯棒(bang)(bang)(bang)(bang)(bang)(bang)軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機可(ke)保留(liu)在前(qian)(qian)位(wei)，充當導(dao)衛，防止芯棒(bang)(bang)(bang)(bang)(bang)(bang)抖動。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)延伸后，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)和(he)芯棒(bang)(bang)(bang)(bang)(bang)(bang)一(yi)(yi)(yi)起通過軋(ya)(ya)(ya)(ya)機向(xiang)前(qian)(qian)移動軋(ya)(ya)(ya)(ya)制(zhi)終(zhong)了時(shi)，后臺輥(gun)(gun)子升起，將(jiang)毛(mao)管(guan)(guan)(guan)(guan)及芯棒(bang)(bang)(bang)(bang)(bang)(bang)送(song)到(dao)輸出(chu)輥(gun)(gun)道(dao)。然后，從輸出(chu)輥(gun)(gun)送(song)到(dao)脫棒(bang)(bang)(bang)(bang)(bang)(bang)機，將(jiang)芯棒(bang)(bang)(bang)(bang)(bang)(bang)從毛(mao)管(guan)(guan)(guan)(guan)中(zhong)脫出(chu)。脫棒(bang)(bang)(bang)(bang)(bang)(bang)后，芯棒(bang)(bang)(bang)(bang)(bang)(bang)先冷卻(que)，再送(song)到(dao)軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)機前(qian)(qian)臺，以備再用(yong)(yong)(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)則(ze)由輥(gun)(gun)道(dao)送(song)走，進(jin)行(xing)下一(yi)(yi)(yi)步加(jia)工。采(cai)用(yong)(yong)(yong)全浮(fu)棒(bang)(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式時(shi)，軋(ya)(ya)(ya)(ya)機生產率最高，因(yin)此，下一(yi)(yi)(yi)根芯棒(bang)(bang)(bang)(bang)(bang)(bang)的(de)(de)前(qian)(qian)端實際上(shang)可(ke)以跟在正在軋(ya)(ya)(ya)(ya)制(zhi)的(de)(de)前(qian)(qian)一(yi)(yi)(yi)根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)的(de)(de)芯棒(bang)(bang)(bang)(bang)(bang)(bang)的(de)(de)后面。這是可(ke)能的(de)(de)，因(yin)為在前(qian)(qian)一(yi)(yi)(yi)根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)完以前(qian)(qian)，后一(yi)(yi)(yi)根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)可(ke)以放在前(qian)(qian)臺上(shang)、并穿好芯棒(bang)(bang)(bang)(bang)(bang)(bang)。

2. 回(hui)退芯棒

  回退芯(xin)(xin)(xin)棒操(cao)(cao)作方(fang)式和(he)浮動芯(xin)(xin)(xin)棒一樣(yang)使(shi)用同(tong)一荒管(guan)(guan)(guan)(guan)推(tui)人機(ji)與芯(xin)(xin)(xin)棒推(tui)入(ru)機(ji)，但是芯(xin)(xin)(xin)棒推(tui)入(ru)機(ji)上加(jia)了(le)一套裝置(zhi)，可(ke)將芯(xin)(xin)(xin)棒的(de)后(hou)(hou)端固定在(zai)芯(xin)(xin)(xin)棒推(tui)入(ru)機(ji)上并使(shi)芯(xin)(xin)(xin)棒回轉(zhuan)。荒管(guan)(guan)(guan)(guan)在(zai)前(qian)臺(tai)的(de)初(chu)始位置(zhi)和(he)夾緊與全浮芯(xin)(xin)(xin)棒操(cao)(cao)作方(fang)式一樣(yang)。然而(er)，在(zai)插入(ru)芯(xin)(xin)(xin)棒時(shi)，不僅(jin)芯(xin)(xin)(xin)棒頭(tou)部穿(chuan)過(guo)(guo)荒管(guan)(guan)(guan)(guan)，而(er)且芯(xin)(xin)(xin)棒要(yao)穿(chuan)過(guo)(guo)軋機(ji)，伸出軋輥臺(tai)肩(jian)約3.5m。當芯(xin)(xin)(xin)棒到達(da)此位置(zhi)后(hou)(hou)，芯(xin)(xin)(xin)棒開(kai)(kai)始回轉(zhuan)，直(zhi)到荒管(guan)(guan)(guan)(guan)接觸軋輥后(hou)(hou)一段時(shi)間才停(ting)止。當芯(xin)(xin)(xin)棒推(tui)入(ru)機(ji)到達(da)行程(cheng)終點時(shi)，壓管(guan)(guan)(guan)(guan)器松開(kai)(kai)，荒管(guan)(guan)(guan)(guan)推(tui)入(ru)機(ji)啟動前(qian)進。于是，荒管(guan)(guan)(guan)(guan)喂入(ru)軋機(ji)。軋制開(kai)(kai)始后(hou)(hou)，芯(xin)(xin)(xin)棒開(kai)(kai)始回退。其回退速度與荒管(guan)(guan)(guan)(guan)的(de)行程(cheng)長度及前(qian)進速度有關，以便(bian)在(zai)軋制過(guo)(guo)程(cheng)結束(shu)，當毛管(guan)(guan)(guan)(guan)離開(kai)(kai)軋輥時(shi)，芯(xin)(xin)(xin)棒正(zheng)好從荒管(guan)(guan)(guan)(guan)中抽出。見圖6-49。然后(hou)(hou)，毛管(guan)(guan)(guan)(guan)從軋機(ji)運走，進行下步加(jia)工(gong)，而(er)芯(xin)(xin)(xin)棒高速返回其初(chu)始位置(zhi)以備(bei)穿(chuan)入(ru)下一根毛管(guan)(guan)(guan)(guan)。

3. 限動芯棒

  限動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作法(fa)是(shi)全浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)和回退芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作法(fa)的折(zhe)中(zhong)(zhong)方法(fa)。采(cai)用(yong)這(zhe)種方法(fa)時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的尾端固定在芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機上(shang)，并可回轉(zhuan)。這(zhe)和回退芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作方式一樣，不(bu)同的是(shi)，鋼(gang)管(guan)(guan)(guan)軋(ya)(ya)制(zhi)時(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)向前(qian)(qian)移動。在軋(ya)(ya)制(zhi)結(jie)束時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)從毛管(guan)(guan)(guan)上(shang)脫出。當(dang)荒(huang)管(guan)(guan)(guan)在前(qian)(qian)臺被夾緊時(shi)，穿入芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)，直(zhi)到芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)前(qian)(qian)端伸出軋(ya)(ya)輥臺肩約(yue)0.3m左右為止(zhi)。插入芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開始回轉(zhuan)，直(zhi)到荒(huang)管(guan)(guan)(guan)接觸軋(ya)(ya)輥后一段(duan)時(shi)間才停止(zhi)。芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)到位(wei)后，壓管(guan)(guan)(guan)器松(song)開，荒(huang)管(guan)(guan)(guan)推入機將荒(huang)管(guan)(guan)(guan)推向軋(ya)(ya)輥，直(zhi)到軋(ya)(ya)制(zhi)過程開始為止(zhi)。軋(ya)(ya)制(zhi)過程中(zhong)(zhong)，芯(xin)(xin)(xin)(xin)捧以低于毛管(guan)(guan)(guan)軸向輸出速(su)度的速(su)度和軋(ya)(ya)件一起(qi)前(qian)(qian)進。軋(ya)(ya)制(zhi)周期結(jie)束時(shi)，毛管(guan)(guan)(guan)從芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)上(shang)脫出，然后，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)高(gao)速(su)返回其初始位(wei)置。

  三種芯(xin)(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)的(de)(de)(de)(de)比較。在采(cai)(cai)用(yong)(yong)回(hui)退芯(xin)(xin)棒(bang)與限動(dong)芯(xin)(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)的(de)(de)(de)(de)工廠，只有生產(chan)D/t小(xiao)于7.5的(de)(de)(de)(de)鋼管時才采(cai)(cai)用(yong)(yong)回(hui)退芯(xin)(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)，而當生產(chan)D/t大于7.5的(de)(de)(de)(de)鋼管時采(cai)(cai)用(yong)(yong)限動(dong)芯(xin)(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)。顯然，采(cai)(cai)用(yong)(yong)回(hui)退和限動(dong)芯(xin)(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)時，軋機產(chan)量比采(cai)(cai)用(yong)(yong)全浮芯(xin)(xin)棒(bang)時低(di)，因為，下一根荒管撥(bo)入到前(qian)(qian)臺之(zhi)前(qian)(qian)，在用(yong)(yong)的(de)(de)(de)(de)芯(xin)(xin)棒(bang)必(bi)須返回(hui)其初始位置。同時，芯(xin)(xin)棒(bang)的(de)(de)(de)(de)冷卻(que)不充分，芯(xin)(xin)棒(bang)壽命不長。