目前采(cai)用(yong)(yong)的(de)有(you)三(san)(san)種芯(xin)棒(bang)操作方(fang)(fang)式。早期的(de)三(san)(san)輥軋管機均采(cai)用(yong)(yong)全(quan)浮(fu)芯(xin)棒(bang)，即使在今天，仍(reng)有(you)一部分機組采(cai)用(yong)(yong)全(quan)浮(fu)芯(xin)棒(bang)操作。但是(shi)，全(quan)浮(fu)芯(xin)棒(bang)操作方(fang)(fang)式有(you)如下缺(que)點(dian)：

（1）軋制特厚(hou)壁管(guan)時不易脫棒；

（2）對各種尺寸(cun)的(de)毛管均需要(yao)配置再加熱爐；

（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。

以下是(shi)三種不同(tong)芯(xin)棒操作方式的(de)簡述。

1. 全浮芯棒

  采用(yong)(yong)全(quan)浮芯(xin)(xin)(xin)(xin)棒(bang)操作(zuo)方(fang)式時，荒(huang)(huang)(huang)管(guan)(guan)(guan)被(bei)撥入(ru)到(dao)(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)機(ji)(ji)(ji)前(qian)的(de)(de)人(ren)口臺(tai)，落到(dao)(dao)和軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)中心線(xian)一(yi)(yi)致的(de)(de)U形槽(cao)里。氣動壓管(guan)(guan)(guan)器壓在(zai)(zai)(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)上，將其夾(jia)緊，芯(xin)(xin)(xin)(xin)棒(bang)推入(ru)機(ji)(ji)(ji)將芯(xin)(xin)(xin)(xin)棒(bang)穿入(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)內。一(yi)(yi)旦芯(xin)(xin)(xin)(xin)棒(bang)完全(quan)穿入(ru)，壓管(guan)(guan)(guan)器就松開，于是(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)連同芯(xin)(xin)(xin)(xin)棒(bang)一(yi)(yi)并向軋(ya)(ya)(ya)(ya)(ya)輥(gun)方(fang)向送(song)去。如果荒(huang)(huang)(huang)管(guan)(guan)(guan)不易喂(wei)入(ru)軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)，就用(yong)(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)機(ji)(ji)(ji)在(zai)(zai)(zai)后(hou)面推下(xia)，以(yi)(yi)幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)喂(wei)入(ru)。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)開始(shi)(shi)軋(ya)(ya)(ya)(ya)(ya)制時，荒(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)機(ji)(ji)(ji)和芯(xin)(xin)(xin)(xin)棒(bang)推入(ru)機(ji)(ji)(ji)便返回到(dao)(dao)初始(shi)(shi)位(wei)置。但是(shi)(shi)，當(dang)采用(yong)(yong)小直徑(jing)芯(xin)(xin)(xin)(xin)棒(bang)軋(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)時，荒(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)機(ji)(ji)(ji)可(ke)保留在(zai)(zai)(zai)前(qian)位(wei)，充當(dang)導衛，防止芯(xin)(xin)(xin)(xin)棒(bang)抖動。荒(huang)(huang)(huang)管(guan)(guan)(guan)延伸后(hou)，荒(huang)(huang)(huang)管(guan)(guan)(guan)和芯(xin)(xin)(xin)(xin)棒(bang)一(yi)(yi)起通過軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)向前(qian)移動軋(ya)(ya)(ya)(ya)(ya)制終(zhong)了時，后(hou)臺(tai)輥(gun)子升起，將毛管(guan)(guan)(guan)及芯(xin)(xin)(xin)(xin)棒(bang)送(song)到(dao)(dao)輸出(chu)輥(gun)道。然(ran)后(hou)，從(cong)輸出(chu)輥(gun)送(song)到(dao)(dao)脫(tuo)(tuo)棒(bang)機(ji)(ji)(ji)，將芯(xin)(xin)(xin)(xin)棒(bang)從(cong)毛管(guan)(guan)(guan)中脫(tuo)(tuo)出(chu)。脫(tuo)(tuo)棒(bang)后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)先冷卻，再送(song)到(dao)(dao)軋(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)機(ji)(ji)(ji)前(qian)臺(tai)，以(yi)(yi)備再用(yong)(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)則由(you)輥(gun)道送(song)走，進行下(xia)一(yi)(yi)步加工。采用(yong)(yong)全(quan)浮棒(bang)操作(zuo)方(fang)式時，軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)生產率最高，因(yin)此，下(xia)一(yi)(yi)根(gen)芯(xin)(xin)(xin)(xin)棒(bang)的(de)(de)前(qian)端實際上可(ke)以(yi)(yi)跟在(zai)(zai)(zai)正在(zai)(zai)(zai)軋(ya)(ya)(ya)(ya)(ya)制的(de)(de)前(qian)一(yi)(yi)根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)的(de)(de)芯(xin)(xin)(xin)(xin)棒(bang)的(de)(de)后(hou)面。這是(shi)(shi)可(ke)能的(de)(de)，因(yin)為在(zai)(zai)(zai)前(qian)一(yi)(yi)根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)(ya)完以(yi)(yi)前(qian)，后(hou)一(yi)(yi)根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)可(ke)以(yi)(yi)放在(zai)(zai)(zai)前(qian)臺(tai)上、并穿好芯(xin)(xin)(xin)(xin)棒(bang)。

2. 回退(tui)芯棒

  回(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作方(fang)(fang)式和浮動芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)(yi)樣(yang)使用(yong)同一(yi)(yi)荒(huang)管(guan)(guan)(guan)(guan)推人機(ji)(ji)(ji)與(yu)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)，但是芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)上加了一(yi)(yi)套裝置(zhi)(zhi)，可(ke)將(jiang)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)(de)后(hou)(hou)端固定在(zai)(zai)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)上并使芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)回(hui)轉。荒(huang)管(guan)(guan)(guan)(guan)在(zai)(zai)前臺的(de)(de)初始位(wei)置(zhi)(zhi)和夾緊與(yu)全(quan)浮芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作方(fang)(fang)式一(yi)(yi)樣(yang)。然(ran)而(er)，在(zai)(zai)插入芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)時(shi)，不僅芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)頭(tou)部穿過荒(huang)管(guan)(guan)(guan)(guan)，而(er)且芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)要(yao)穿過軋(ya)機(ji)(ji)(ji)，伸出(chu)軋(ya)輥(gun)臺肩約3.5m。當芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)到達此位(wei)置(zhi)(zhi)后(hou)(hou)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開(kai)(kai)(kai)始回(hui)轉，直(zhi)到荒(huang)管(guan)(guan)(guan)(guan)接(jie)觸軋(ya)輥(gun)后(hou)(hou)一(yi)(yi)段時(shi)間才(cai)停(ting)止。當芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)到達行程終(zhong)點時(shi)，壓管(guan)(guan)(guan)(guan)器松開(kai)(kai)(kai)，荒(huang)管(guan)(guan)(guan)(guan)推入機(ji)(ji)(ji)啟(qi)動前進。于是，荒(huang)管(guan)(guan)(guan)(guan)喂入軋(ya)機(ji)(ji)(ji)。軋(ya)制(zhi)開(kai)(kai)(kai)始后(hou)(hou)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開(kai)(kai)(kai)始回(hui)退。其回(hui)退速度(du)(du)與(yu)荒(huang)管(guan)(guan)(guan)(guan)的(de)(de)行程長(chang)度(du)(du)及前進速度(du)(du)有關，以便在(zai)(zai)軋(ya)制(zhi)過程結(jie)束，當毛管(guan)(guan)(guan)(guan)離開(kai)(kai)(kai)軋(ya)輥(gun)時(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)正好從荒(huang)管(guan)(guan)(guan)(guan)中(zhong)抽出(chu)。見圖(tu)6-49。然(ran)后(hou)(hou)，毛管(guan)(guan)(guan)(guan)從軋(ya)機(ji)(ji)(ji)運走，進行下步加工，而(er)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)高速返回(hui)其初始位(wei)置(zhi)(zhi)以備(bei)穿入下一(yi)(yi)根(gen)毛管(guan)(guan)(guan)(guan)。

3. 限動芯棒

  限動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)(cao)作(zuo)法(fa)是全(quan)浮(fu)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)和(he)回(hui)(hui)退芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)(cao)作(zuo)法(fa)的(de)折中方(fang)法(fa)。采用這種方(fang)法(fa)時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的(de)尾端(duan)固(gu)定(ding)在(zai)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推入(ru)機(ji)上，并可回(hui)(hui)轉。這和(he)回(hui)(hui)退芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)(cao)作(zuo)方(fang)式一樣，不同的(de)是，鋼管(guan)(guan)(guan)軋(ya)制(zhi)(zhi)時(shi)(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)向(xiang)前(qian)移動。在(zai)軋(ya)制(zhi)(zhi)結束時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)從毛(mao)(mao)管(guan)(guan)(guan)上脫(tuo)出。當荒(huang)管(guan)(guan)(guan)在(zai)前(qian)臺被夾(jia)緊(jin)時(shi)(shi)，穿入(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)，直(zhi)到(dao)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)前(qian)端(duan)伸出軋(ya)輥臺肩約0.3m左右為止。插入(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開始回(hui)(hui)轉，直(zhi)到(dao)荒(huang)管(guan)(guan)(guan)接觸軋(ya)輥后一段時(shi)(shi)間才停止。芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到(dao)位(wei)后，壓管(guan)(guan)(guan)器(qi)松開，荒(huang)管(guan)(guan)(guan)推入(ru)機(ji)將荒(huang)管(guan)(guan)(guan)推向(xiang)軋(ya)輥，直(zhi)到(dao)軋(ya)制(zhi)(zhi)過程開始為止。軋(ya)制(zhi)(zhi)過程中，芯(xin)(xin)(xin)(xin)捧以低于毛(mao)(mao)管(guan)(guan)(guan)軸向(xiang)輸出速度的(de)速度和(he)軋(ya)件一起(qi)前(qian)進(jin)。軋(ya)制(zhi)(zhi)周期(qi)結束時(shi)(shi)，毛(mao)(mao)管(guan)(guan)(guan)從芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)上脫(tuo)出，然后，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速返回(hui)(hui)其初始位(wei)置。

  三種芯(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)(shi)的(de)比較。在(zai)采(cai)用(yong)回(hui)(hui)退(tui)芯(xin)棒(bang)與限動(dong)芯(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)(shi)的(de)工廠，只有(you)生產(chan)D/t小于7.5的(de)鋼(gang)管(guan)時(shi)(shi)才采(cai)用(yong)回(hui)(hui)退(tui)芯(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)(shi)，而當生產(chan)D/t大于7.5的(de)鋼(gang)管(guan)時(shi)(shi)采(cai)用(yong)限動(dong)芯(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)(shi)。顯然，采(cai)用(yong)回(hui)(hui)退(tui)和限動(dong)芯(xin)棒(bang)操(cao)作方(fang)(fang)式(shi)(shi)時(shi)(shi)，軋(ya)機(ji)產(chan)量比采(cai)用(yong)全浮芯(xin)棒(bang)時(shi)(shi)低，因為(wei)，下(xia)一根荒管(guan)撥入到前臺之前，在(zai)用(yong)的(de)芯(xin)棒(bang)必須返(fan)回(hui)(hui)其初始位置。同(tong)時(shi)(shi)，芯(xin)棒(bang)的(de)冷卻不充分，芯(xin)棒(bang)壽命不長(chang)。