目前采用(yong)(yong)的有三種芯(xin)棒操(cao)作(zuo)方(fang)(fang)式。早期(qi)的三輥軋管機均(jun)采用(yong)(yong)全(quan)浮芯(xin)棒，即使在(zai)今天，仍有一部分機組采用(yong)(yong)全(quan)浮芯(xin)棒操(cao)作(zuo)。但是，全(quan)浮芯(xin)棒操(cao)作(zuo)方(fang)(fang)式有如下(xia)缺點：

（1）軋制特(te)厚壁管時不易脫棒；

（2）對(dui)各種尺寸(cun)的毛管均需要配置再加熱爐；

（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(xia)是(shi)三種不(bu)同芯(xin)棒操作方(fang)式的簡述。

1. 全浮芯(xin)棒

  采用(yong)全浮芯(xin)(xin)(xin)棒(bang)操(cao)作方(fang)式時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)被(bei)撥入(ru)(ru)(ru)到荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)前(qian)(qian)的(de)(de)人口臺，落到和(he)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)(ji)中(zhong)心線一(yi)(yi)(yi)致的(de)(de)U形(xing)槽(cao)里。氣動(dong)壓(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)器(qi)壓(ya)在荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)上(shang)，將其夾(jia)緊，芯(xin)(xin)(xin)棒(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)將芯(xin)(xin)(xin)棒(bang)穿(chuan)入(ru)(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)內(nei)。一(yi)(yi)(yi)旦(dan)芯(xin)(xin)(xin)棒(bang)完全穿(chuan)入(ru)(ru)(ru)，壓(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)器(qi)就(jiu)松開，于(yu)是(shi)(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)連同芯(xin)(xin)(xin)棒(bang)一(yi)(yi)(yi)并向軋(ya)(ya)(ya)(ya)輥(gun)方(fang)向送去。如果(guo)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)不(bu)易喂入(ru)(ru)(ru)軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)(ji)，就(jiu)用(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)在后(hou)(hou)面(mian)推(tui)下，以(yi)幫(bang)助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)喂入(ru)(ru)(ru)。當荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)開始(shi)軋(ya)(ya)(ya)(ya)制時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)和(he)芯(xin)(xin)(xin)棒(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)便返回到初始(shi)位置。但是(shi)(shi)，當采用(yong)小直徑芯(xin)(xin)(xin)棒(bang)軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)可(ke)(ke)保留(liu)在前(qian)(qian)位，充當導衛，防止芯(xin)(xin)(xin)棒(bang)抖動(dong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)延伸后(hou)(hou)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)和(he)芯(xin)(xin)(xin)棒(bang)一(yi)(yi)(yi)起(qi)(qi)通過軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)(ji)向前(qian)(qian)移動(dong)軋(ya)(ya)(ya)(ya)制終了時(shi)，后(hou)(hou)臺輥(gun)子(zi)升(sheng)起(qi)(qi)，將毛管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)及芯(xin)(xin)(xin)棒(bang)送到輸出(chu)輥(gun)道。然后(hou)(hou)，從輸出(chu)輥(gun)送到脫棒(bang)機(ji)(ji)(ji)(ji)，將芯(xin)(xin)(xin)棒(bang)從毛管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)中(zhong)脫出(chu)。脫棒(bang)后(hou)(hou)，芯(xin)(xin)(xin)棒(bang)先冷卻(que)，再送到軋(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)機(ji)(ji)(ji)(ji)前(qian)(qian)臺，以(yi)備(bei)再用(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)則由輥(gun)道送走，進行下一(yi)(yi)(yi)步加(jia)工。采用(yong)全浮棒(bang)操(cao)作方(fang)式時(shi)，軋(ya)(ya)(ya)(ya)機(ji)(ji)(ji)(ji)生產(chan)率(lv)最高，因此，下一(yi)(yi)(yi)根(gen)(gen)芯(xin)(xin)(xin)棒(bang)的(de)(de)前(qian)(qian)端實際上(shang)可(ke)(ke)以(yi)跟在正在軋(ya)(ya)(ya)(ya)制的(de)(de)前(qian)(qian)一(yi)(yi)(yi)根(gen)(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)芯(xin)(xin)(xin)棒(bang)的(de)(de)后(hou)(hou)面(mian)。這是(shi)(shi)可(ke)(ke)能的(de)(de)，因為在前(qian)(qian)一(yi)(yi)(yi)根(gen)(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)完以(yi)前(qian)(qian)，后(hou)(hou)一(yi)(yi)(yi)根(gen)(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)可(ke)(ke)以(yi)放(fang)在前(qian)(qian)臺上(shang)、并穿(chuan)好芯(xin)(xin)(xin)棒(bang)。

2. 回(hui)退芯棒

  回(hui)(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操作方式和(he)浮動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)一(yi)樣(yang)使用同一(yi)荒(huang)管(guan)(guan)(guan)推(tui)(tui)人機(ji)與芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)，但是(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)上加了一(yi)套裝置，可將芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的(de)后(hou)端(duan)固定在(zai)(zai)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)上并使芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)回(hui)(hui)轉。荒(huang)管(guan)(guan)(guan)在(zai)(zai)前臺的(de)初始位置和(he)夾緊(jin)與全浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操作方式一(yi)樣(yang)。然而(er)，在(zai)(zai)插(cha)入(ru)(ru)(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時，不(bu)僅芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)頭(tou)部穿(chuan)過(guo)(guo)荒(huang)管(guan)(guan)(guan)，而(er)且芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)要穿(chuan)過(guo)(guo)軋(ya)(ya)(ya)(ya)機(ji)，伸出軋(ya)(ya)(ya)(ya)輥(gun)臺肩約3.5m。當(dang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到達此位置后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開(kai)始回(hui)(hui)轉，直到荒(huang)管(guan)(guan)(guan)接(jie)觸軋(ya)(ya)(ya)(ya)輥(gun)后(hou)一(yi)段時間(jian)才停(ting)止。當(dang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機(ji)到達行程終點時，壓管(guan)(guan)(guan)器松開(kai)，荒(huang)管(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)(ru)機(ji)啟動前進。于(yu)是(shi)，荒(huang)管(guan)(guan)(guan)喂(wei)入(ru)(ru)(ru)軋(ya)(ya)(ya)(ya)機(ji)。軋(ya)(ya)(ya)(ya)制(zhi)開(kai)始后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開(kai)始回(hui)(hui)退(tui)。其回(hui)(hui)退(tui)速度與荒(huang)管(guan)(guan)(guan)的(de)行程長度及前進速度有關，以便(bian)在(zai)(zai)軋(ya)(ya)(ya)(ya)制(zhi)過(guo)(guo)程結束，當(dang)毛(mao)管(guan)(guan)(guan)離開(kai)軋(ya)(ya)(ya)(ya)輥(gun)時，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)正(zheng)好從荒(huang)管(guan)(guan)(guan)中抽出。見圖(tu)6-49。然后(hou)，毛(mao)管(guan)(guan)(guan)從軋(ya)(ya)(ya)(ya)機(ji)運走，進行下步加工，而(er)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速返回(hui)(hui)其初始位置以備穿(chuan)入(ru)(ru)(ru)下一(yi)根毛(mao)管(guan)(guan)(guan)。

3. 限動芯棒

  限動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)法(fa)是全浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)和(he)回(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)法(fa)的(de)折(zhe)中(zhong)方(fang)法(fa)。采用這(zhe)種(zhong)方(fang)法(fa)時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的(de)尾端(duan)固定在(zai)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)機上(shang)，并可回(hui)轉。這(zhe)和(he)回(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)方(fang)式一(yi)樣，不同的(de)是，鋼管(guan)(guan)(guan)軋(ya)(ya)(ya)制(zhi)時(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)向前移動。在(zai)軋(ya)(ya)(ya)制(zhi)結束(shu)時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)從(cong)毛管(guan)(guan)(guan)上(shang)脫(tuo)出(chu)。當荒(huang)管(guan)(guan)(guan)在(zai)前臺(tai)被夾緊(jin)時(shi)，穿入(ru)(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)，直到(dao)(dao)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)前端(duan)伸出(chu)軋(ya)(ya)(ya)輥(gun)臺(tai)肩約0.3m左右為止。插入(ru)(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開始(shi)回(hui)轉，直到(dao)(dao)荒(huang)管(guan)(guan)(guan)接(jie)觸軋(ya)(ya)(ya)輥(gun)后(hou)(hou)一(yi)段時(shi)間才停止。芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到(dao)(dao)位后(hou)(hou)，壓管(guan)(guan)(guan)器松開，荒(huang)管(guan)(guan)(guan)推(tui)入(ru)(ru)機將荒(huang)管(guan)(guan)(guan)推(tui)向軋(ya)(ya)(ya)輥(gun)，直到(dao)(dao)軋(ya)(ya)(ya)制(zhi)過程開始(shi)為止。軋(ya)(ya)(ya)制(zhi)過程中(zhong)，芯(xin)(xin)(xin)(xin)捧以低于毛管(guan)(guan)(guan)軸向輸出(chu)速(su)度(du)的(de)速(su)度(du)和(he)軋(ya)(ya)(ya)件一(yi)起(qi)前進(jin)。軋(ya)(ya)(ya)制(zhi)周期結束(shu)時(shi)，毛管(guan)(guan)(guan)從(cong)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)上(shang)脫(tuo)出(chu)，然(ran)后(hou)(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速(su)返(fan)回(hui)其初(chu)始(shi)位置。

  三種芯(xin)棒(bang)操(cao)作方(fang)式的(de)比較。在采(cai)用(yong)回退(tui)芯(xin)棒(bang)與限動芯(xin)棒(bang)操(cao)作方(fang)式的(de)工廠，只(zhi)有生產D/t小于7.5的(de)鋼管(guan)時才(cai)采(cai)用(yong)回退(tui)芯(xin)棒(bang)操(cao)作方(fang)式，而當生產D/t大于7.5的(de)鋼管(guan)時采(cai)用(yong)限動芯(xin)棒(bang)操(cao)作方(fang)式。顯然(ran)，采(cai)用(yong)回退(tui)和限動芯(xin)棒(bang)操(cao)作方(fang)式時，軋(ya)機產量比采(cai)用(yong)全(quan)浮芯(xin)棒(bang)時低(di)，因為，下一根荒(huang)管(guan)撥入到前臺之前，在用(yong)的(de)芯(xin)棒(bang)必須返(fan)回其初(chu)始位置。同(tong)時，芯(xin)棒(bang)的(de)冷卻(que)不(bu)充分，芯(xin)棒(bang)壽命不(bu)長。