目前(qian)采用(yong)(yong)的(de)有(you)三(san)種芯(xin)棒操(cao)作方(fang)式。早期(qi)的(de)三(san)輥軋管機(ji)均采用(yong)(yong)全浮(fu)芯(xin)棒，即使在(zai)今天，仍(reng)有(you)一部(bu)分機(ji)組(zu)采用(yong)(yong)全浮(fu)芯(xin)棒操(cao)作。但(dan)是，全浮(fu)芯(xin)棒操(cao)作方(fang)式有(you)如下缺點：

（1）軋(ya)制(zhi)特厚(hou)壁管時不易脫(tuo)棒；

（2）對各種尺(chi)寸(cun)的毛管均(jun)需要配置再加熱爐；

（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。

以下是三(san)種不同芯棒操作方式的簡(jian)述。

1. 全浮(fu)芯棒

  采用(yong)全(quan)浮(fu)芯(xin)棒(bang)(bang)(bang)操作方(fang)式時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)被撥(bo)入(ru)(ru)(ru)(ru)到(dao)(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)前(qian)的(de)人口臺，落到(dao)(dao)和軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)中心(xin)線一(yi)(yi)致的(de)U形槽里。氣(qi)動壓管(guan)(guan)(guan)(guan)(guan)器(qi)壓在(zai)(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)上(shang)，將其夾緊，芯(xin)棒(bang)(bang)(bang)推入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)將芯(xin)棒(bang)(bang)(bang)穿入(ru)(ru)(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)內。一(yi)(yi)旦芯(xin)棒(bang)(bang)(bang)完全(quan)穿入(ru)(ru)(ru)(ru)，壓管(guan)(guan)(guan)(guan)(guan)器(qi)就松開(kai)，于(yu)是，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)連同(tong)芯(xin)棒(bang)(bang)(bang)一(yi)(yi)并(bing)向(xiang)(xiang)軋(ya)(ya)(ya)(ya)輥(gun)方(fang)向(xiang)(xiang)送(song)(song)去。如(ru)果(guo)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)不易喂(wei)入(ru)(ru)(ru)(ru)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)，就用(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)在(zai)(zai)后(hou)面(mian)(mian)推下，以(yi)(yi)幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)喂(wei)入(ru)(ru)(ru)(ru)。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)開(kai)始軋(ya)(ya)(ya)(ya)制時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)和芯(xin)棒(bang)(bang)(bang)推入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)便返(fan)回(hui)到(dao)(dao)初始位(wei)置。但是，當(dang)采用(yong)小直徑(jing)芯(xin)棒(bang)(bang)(bang)軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)(ji)可(ke)保留在(zai)(zai)前(qian)位(wei)，充當(dang)導衛(wei)，防止(zhi)芯(xin)棒(bang)(bang)(bang)抖動。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)延伸后(hou)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)和芯(xin)棒(bang)(bang)(bang)一(yi)(yi)起通過軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)向(xiang)(xiang)前(qian)移動軋(ya)(ya)(ya)(ya)制終了(le)時(shi)，后(hou)臺輥(gun)子(zi)升起，將毛(mao)管(guan)(guan)(guan)(guan)(guan)及(ji)芯(xin)棒(bang)(bang)(bang)送(song)(song)到(dao)(dao)輸(shu)出輥(gun)道。然后(hou)，從輸(shu)出輥(gun)送(song)(song)到(dao)(dao)脫棒(bang)(bang)(bang)機(ji)(ji)(ji)，將芯(xin)棒(bang)(bang)(bang)從毛(mao)管(guan)(guan)(guan)(guan)(guan)中脫出。脫棒(bang)(bang)(bang)后(hou)，芯(xin)棒(bang)(bang)(bang)先冷卻，再(zai)送(song)(song)到(dao)(dao)軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)機(ji)(ji)(ji)前(qian)臺，以(yi)(yi)備再(zai)用(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)則由輥(gun)道送(song)(song)走，進(jin)行下一(yi)(yi)步加工。采用(yong)全(quan)浮(fu)棒(bang)(bang)(bang)操作方(fang)式時(shi)，軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)生產(chan)率最高，因此，下一(yi)(yi)根芯(xin)棒(bang)(bang)(bang)的(de)前(qian)端(duan)實(shi)際上(shang)可(ke)以(yi)(yi)跟在(zai)(zai)正在(zai)(zai)軋(ya)(ya)(ya)(ya)制的(de)前(qian)一(yi)(yi)根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)的(de)芯(xin)棒(bang)(bang)(bang)的(de)后(hou)面(mian)(mian)。這是可(ke)能(neng)的(de)，因為在(zai)(zai)前(qian)一(yi)(yi)根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)完以(yi)(yi)前(qian)，后(hou)一(yi)(yi)根荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)可(ke)以(yi)(yi)放在(zai)(zai)前(qian)臺上(shang)、并(bing)穿好芯(xin)棒(bang)(bang)(bang)。

2. 回退芯棒

  回(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)式和(he)浮動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)一樣使(shi)用同一荒(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)人機與(yu)(yu)(yu)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機，但是(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機上加了一套裝置，可將芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的(de)后(hou)端固定在(zai)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機上并使(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)回(hui)轉。荒(huang)管(guan)(guan)(guan)(guan)在(zai)前(qian)(qian)臺(tai)的(de)初始(shi)位置和(he)夾緊與(yu)(yu)(yu)全浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)式一樣。然而(er)，在(zai)插入(ru)(ru)(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時(shi)，不(bu)僅芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)頭(tou)部穿過(guo)荒(huang)管(guan)(guan)(guan)(guan)，而(er)且芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)要穿過(guo)軋(ya)(ya)(ya)機，伸(shen)出軋(ya)(ya)(ya)輥(gun)臺(tai)肩約3.5m。當芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到達(da)此位置后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開始(shi)回(hui)轉，直(zhi)到荒(huang)管(guan)(guan)(guan)(guan)接觸軋(ya)(ya)(ya)輥(gun)后(hou)一段時(shi)間才停止。當芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機到達(da)行程(cheng)終點時(shi)，壓管(guan)(guan)(guan)(guan)器松開，荒(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)(ru)機啟動前(qian)(qian)進(jin)。于是(shi)，荒(huang)管(guan)(guan)(guan)(guan)喂入(ru)(ru)(ru)軋(ya)(ya)(ya)機。軋(ya)(ya)(ya)制開始(shi)后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開始(shi)回(hui)退(tui)。其回(hui)退(tui)速度與(yu)(yu)(yu)荒(huang)管(guan)(guan)(guan)(guan)的(de)行程(cheng)長度及(ji)前(qian)(qian)進(jin)速度有(you)關(guan)，以便在(zai)軋(ya)(ya)(ya)制過(guo)程(cheng)結(jie)束，當毛管(guan)(guan)(guan)(guan)離開軋(ya)(ya)(ya)輥(gun)時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)正好從(cong)荒(huang)管(guan)(guan)(guan)(guan)中抽(chou)出。見圖6-49。然后(hou)，毛管(guan)(guan)(guan)(guan)從(cong)軋(ya)(ya)(ya)機運走，進(jin)行下(xia)步加工，而(er)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速返(fan)回(hui)其初始(shi)位置以備穿入(ru)(ru)(ru)下(xia)一根毛管(guan)(guan)(guan)(guan)。

3. 限動(dong)芯棒(bang)

  限(xian)動(dong)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)作法(fa)是全(quan)浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)和回退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)作法(fa)的折中方(fang)法(fa)。采用這種(zhong)方(fang)法(fa)時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的尾(wei)端(duan)(duan)固定在芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推(tui)入(ru)機(ji)上，并可(ke)回轉。這和回退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)作方(fang)式(shi)一樣，不同的是，鋼管(guan)(guan)軋(ya)制(zhi)(zhi)時(shi)(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)向(xiang)(xiang)前(qian)移動(dong)。在軋(ya)制(zhi)(zhi)結束(shu)時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)從毛管(guan)(guan)上脫出(chu)(chu)。當荒管(guan)(guan)在前(qian)臺被夾緊時(shi)(shi)，穿入(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)，直(zhi)到(dao)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)前(qian)端(duan)(duan)伸(shen)出(chu)(chu)軋(ya)輥臺肩約0.3m左右為(wei)止。插入(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)(kai)始(shi)回轉，直(zhi)到(dao)荒管(guan)(guan)接觸軋(ya)輥后(hou)一段時(shi)(shi)間(jian)才停(ting)止。芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)到(dao)位(wei)后(hou)，壓管(guan)(guan)器松開(kai)(kai)，荒管(guan)(guan)推(tui)入(ru)機(ji)將荒管(guan)(guan)推(tui)向(xiang)(xiang)軋(ya)輥，直(zhi)到(dao)軋(ya)制(zhi)(zhi)過(guo)程開(kai)(kai)始(shi)為(wei)止。軋(ya)制(zhi)(zhi)過(guo)程中，芯(xin)(xin)(xin)(xin)捧以低于毛管(guan)(guan)軸(zhou)向(xiang)(xiang)輸出(chu)(chu)速度的速度和軋(ya)件(jian)一起前(qian)進。軋(ya)制(zhi)(zhi)周(zhou)期結束(shu)時(shi)(shi)，毛管(guan)(guan)從芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)上脫出(chu)(chu)，然后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)高速返回其初始(shi)位(wei)置。

  三(san)種(zhong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)(fang)式(shi)(shi)的(de)(de)比(bi)較。在(zai)采用(yong)回(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)與限(xian)動(dong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)(fang)式(shi)(shi)的(de)(de)工廠，只有生產D/t小于7.5的(de)(de)鋼管時(shi)才采用(yong)回(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)(fang)式(shi)(shi)，而當生產D/t大于7.5的(de)(de)鋼管時(shi)采用(yong)限(xian)動(dong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)(fang)式(shi)(shi)。顯然，采用(yong)回(hui)退和限(xian)動(dong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)操作方(fang)(fang)(fang)式(shi)(shi)時(shi)，軋(ya)機產量比(bi)采用(yong)全浮(fu)芯(xin)(xin)(xin)棒(bang)(bang)(bang)時(shi)低，因為，下一根荒管撥入到前(qian)臺(tai)之前(qian)，在(zai)用(yong)的(de)(de)芯(xin)(xin)(xin)棒(bang)(bang)(bang)必須返回(hui)其初始(shi)位置。同時(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)的(de)(de)冷卻不充(chong)分(fen)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)壽命不長(chang)。