目前(qian)采(cai)用的有(you)三種芯(xin)棒操(cao)作方式(shi)。早期的三輥軋管機均采(cai)用全浮(fu)(fu)芯(xin)棒，即(ji)使在(zai)今天，仍有(you)一部(bu)分機組采(cai)用全浮(fu)(fu)芯(xin)棒操(cao)作。但是，全浮(fu)(fu)芯(xin)棒操(cao)作方式(shi)有(you)如下缺(que)點(dian)：

（1）軋(ya)制特厚壁管(guan)時不(bu)易脫棒；

（2）對(dui)各種尺(chi)寸的毛管(guan)均需(xu)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。

以下是三種不(bu)同(tong)芯棒操作方式的(de)簡述。

1. 全浮芯棒(bang)

  采(cai)用(yong)全(quan)(quan)浮(fu)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)式時(shi)，荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)被撥入到荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入機(ji)(ji)(ji)前(qian)(qian)的人口(kou)臺，落到和(he)(he)軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)中(zhong)心線一(yi)致的U形(xing)槽里。氣(qi)動(dong)壓(ya)管(guan)(guan)(guan)(guan)(guan)(guan)器(qi)壓(ya)在(zai)(zai)荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)上(shang)，將(jiang)其(qi)夾緊，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入機(ji)(ji)(ji)將(jiang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)穿(chuan)(chuan)入荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)內。一(yi)旦芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)完(wan)全(quan)(quan)穿(chuan)(chuan)入，壓(ya)管(guan)(guan)(guan)(guan)(guan)(guan)器(qi)就(jiu)松開，于是，荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)連(lian)同(tong)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)并(bing)向(xiang)軋(ya)(ya)(ya)(ya)(ya)輥(gun)方(fang)(fang)向(xiang)送(song)去(qu)。如果(guo)荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)不易(yi)喂(wei)入軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)，就(jiu)用(yong)荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入機(ji)(ji)(ji)在(zai)(zai)后面(mian)推(tui)下，以幫助荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)喂(wei)入。當荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)開始(shi)軋(ya)(ya)(ya)(ya)(ya)制(zhi)時(shi)，荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入機(ji)(ji)(ji)和(he)(he)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入機(ji)(ji)(ji)便返回到初始(shi)位置(zhi)。但(dan)是，當采(cai)用(yong)小直徑芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)軋(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)時(shi)，荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)推(tui)入機(ji)(ji)(ji)可保留在(zai)(zai)前(qian)(qian)位，充當導衛，防(fang)止芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)抖動(dong)。荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)延伸后，荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)和(he)(he)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)起通過(guo)軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)向(xiang)前(qian)(qian)移動(dong)軋(ya)(ya)(ya)(ya)(ya)制(zhi)終了時(shi)，后臺輥(gun)子(zi)升起，將(jiang)毛管(guan)(guan)(guan)(guan)(guan)(guan)及芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)送(song)到輸出輥(gun)道(dao)(dao)。然后，從(cong)輸出輥(gun)送(song)到脫(tuo)棒(bang)(bang)(bang)(bang)(bang)機(ji)(ji)(ji)，將(jiang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)從(cong)毛管(guan)(guan)(guan)(guan)(guan)(guan)中(zhong)脫(tuo)出。脫(tuo)棒(bang)(bang)(bang)(bang)(bang)后，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)先冷(leng)卻(que)，再送(song)到軋(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)(guan)(guan)機(ji)(ji)(ji)前(qian)(qian)臺，以備(bei)再用(yong)。荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)則由輥(gun)道(dao)(dao)送(song)走，進行(xing)下一(yi)步加工(gong)。采(cai)用(yong)全(quan)(quan)浮(fu)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)方(fang)(fang)式時(shi)，軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)生產率最(zui)高，因此(ci)，下一(yi)根芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的前(qian)(qian)端實際上(shang)可以跟在(zai)(zai)正在(zai)(zai)軋(ya)(ya)(ya)(ya)(ya)制(zhi)的前(qian)(qian)一(yi)根荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)的芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的后面(mian)。這(zhe)是可能(neng)的，因為(wei)在(zai)(zai)前(qian)(qian)一(yi)根荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)(ya)完(wan)以前(qian)(qian)，后一(yi)根荒(huang)管(guan)(guan)(guan)(guan)(guan)(guan)可以放在(zai)(zai)前(qian)(qian)臺上(shang)、并(bing)穿(chuan)(chuan)好芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)。

2. 回(hui)退(tui)芯棒

  回(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作方式和浮動(dong)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)樣使用(yong)同一(yi)荒管(guan)(guan)(guan)推(tui)人機(ji)與(yu)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)機(ji)，但(dan)是芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)機(ji)上(shang)加(jia)了一(yi)套裝(zhuang)置，可將芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)(de)后(hou)端固(gu)定在芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)機(ji)上(shang)并使芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)回(hui)轉(zhuan)。荒管(guan)(guan)(guan)在前臺(tai)的(de)(de)初始位置和夾緊與(yu)全浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作方式一(yi)樣。然而(er)，在插入(ru)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)時(shi)，不(bu)僅(jin)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)頭部穿過(guo)荒管(guan)(guan)(guan)，而(er)且芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)要穿過(guo)軋(ya)機(ji)，伸(shen)出(chu)軋(ya)輥臺(tai)肩約3.5m。當(dang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)到(dao)達(da)此位置后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開(kai)(kai)(kai)始回(hui)轉(zhuan)，直(zhi)到(dao)荒管(guan)(guan)(guan)接觸軋(ya)輥后(hou)一(yi)段時(shi)間才停止。當(dang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)機(ji)到(dao)達(da)行(xing)(xing)(xing)程終點時(shi)，壓管(guan)(guan)(guan)器松開(kai)(kai)(kai)，荒管(guan)(guan)(guan)推(tui)入(ru)機(ji)啟動(dong)前進(jin)。于是，荒管(guan)(guan)(guan)喂入(ru)軋(ya)機(ji)。軋(ya)制開(kai)(kai)(kai)始后(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開(kai)(kai)(kai)始回(hui)退(tui)。其回(hui)退(tui)速(su)度與(yu)荒管(guan)(guan)(guan)的(de)(de)行(xing)(xing)(xing)程長度及前進(jin)速(su)度有關，以便在軋(ya)制過(guo)程結束，當(dang)毛管(guan)(guan)(guan)離開(kai)(kai)(kai)軋(ya)輥時(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)正好從荒管(guan)(guan)(guan)中抽出(chu)。見(jian)圖6-49。然后(hou)，毛管(guan)(guan)(guan)從軋(ya)機(ji)運走，進(jin)行(xing)(xing)(xing)下(xia)步加(jia)工，而(er)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)高速(su)返回(hui)其初始位置以備穿入(ru)下(xia)一(yi)根毛管(guan)(guan)(guan)。

3. 限動芯棒

  限(xian)動芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)法是(shi)全(quan)浮芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)和回(hui)(hui)(hui)(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)法的(de)(de)折(zhe)中(zhong)方法。采用這種方法時(shi)(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)(de)尾端(duan)固定在(zai)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)機上，并可(ke)回(hui)(hui)(hui)(hui)轉。這和回(hui)(hui)(hui)(hui)退芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)方式一樣，不同的(de)(de)是(shi)，鋼(gang)管(guan)軋(ya)制時(shi)(shi)(shi)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)向(xiang)(xiang)(xiang)前移(yi)動。在(zai)軋(ya)制結束時(shi)(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)從毛管(guan)上脫(tuo)出(chu)。當荒(huang)管(guan)在(zai)前臺被夾(jia)緊時(shi)(shi)(shi)，穿(chuan)入(ru)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)，直(zhi)(zhi)到芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)前端(duan)伸出(chu)軋(ya)輥臺肩約(yue)0.3m左右為止(zhi)(zhi)。插入(ru)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)時(shi)(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開始回(hui)(hui)(hui)(hui)轉，直(zhi)(zhi)到荒(huang)管(guan)接觸(chu)軋(ya)輥后一段時(shi)(shi)(shi)間(jian)才(cai)停止(zhi)(zhi)。芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)到位(wei)后，壓管(guan)器松開，荒(huang)管(guan)推(tui)(tui)入(ru)機將荒(huang)管(guan)推(tui)(tui)向(xiang)(xiang)(xiang)軋(ya)輥，直(zhi)(zhi)到軋(ya)制過(guo)程開始為止(zhi)(zhi)。軋(ya)制過(guo)程中(zhong)，芯(xin)(xin)(xin)捧以低于毛管(guan)軸向(xiang)(xiang)(xiang)輸出(chu)速度(du)的(de)(de)速度(du)和軋(ya)件一起前進。軋(ya)制周(zhou)期結束時(shi)(shi)(shi)，毛管(guan)從芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)上脫(tuo)出(chu)，然后，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)高(gao)速返回(hui)(hui)(hui)(hui)其初始位(wei)置(zhi)。

  三種芯(xin)棒(bang)操(cao)作(zuo)方式(shi)的比較(jiao)。在采(cai)用(yong)回退芯(xin)棒(bang)與(yu)限(xian)動(dong)芯(xin)棒(bang)操(cao)作(zuo)方式(shi)的工廠(chang)，只(zhi)有生(sheng)產(chan)D/t小(xiao)于7.5的鋼(gang)管(guan)時(shi)才采(cai)用(yong)回退芯(xin)棒(bang)操(cao)作(zuo)方式(shi)，而當生(sheng)產(chan)D/t大于7.5的鋼(gang)管(guan)時(shi)采(cai)用(yong)限(xian)動(dong)芯(xin)棒(bang)操(cao)作(zuo)方式(shi)。顯然，采(cai)用(yong)回退和限(xian)動(dong)芯(xin)棒(bang)操(cao)作(zuo)方式(shi)時(shi)，軋機產(chan)量比采(cai)用(yong)全(quan)浮芯(xin)棒(bang)時(shi)低，因為，下(xia)一根荒管(guan)撥入到前臺之前，在用(yong)的芯(xin)棒(bang)必須返(fan)回其(qi)初始位置(zhi)。同時(shi)，芯(xin)棒(bang)的冷卻不充分，芯(xin)棒(bang)壽命(ming)不長。