目前(qian)采(cai)(cai)用(yong)(yong)的有(you)三種芯棒(bang)操(cao)(cao)作方式(shi)。早期的三輥(gun)軋管機均采(cai)(cai)用(yong)(yong)全浮芯棒(bang)，即使在(zai)今天(tian)，仍有(you)一部分機組采(cai)(cai)用(yong)(yong)全浮芯棒(bang)操(cao)(cao)作。但(dan)是，全浮芯棒(bang)操(cao)(cao)作方式(shi)有(you)如下(xia)缺點：

（1）軋制(zhi)特厚壁管時不易脫棒(bang)；

（2）對各種尺寸的毛管(guan)均需要(yao)配置再(zai)加熱爐；

（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(san)種不同芯棒(bang)操作方式的簡述。

1. 全浮芯棒

  采用(yong)全浮(fu)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式時，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)被撥入(ru)(ru)(ru)(ru)(ru)到(dao)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)(ru)(ru)(ru)機(ji)(ji)前(qian)(qian)(qian)的(de)人口臺(tai)，落到(dao)和(he)軋機(ji)(ji)中心線一(yi)(yi)致(zhi)的(de)U形槽里。氣動壓管(guan)(guan)(guan)器(qi)壓在(zai)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)上，將(jiang)其夾緊，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)(ru)(ru)機(ji)(ji)將(jiang)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)穿(chuan)入(ru)(ru)(ru)(ru)(ru)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)內(nei)。一(yi)(yi)旦芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)完(wan)全穿(chuan)入(ru)(ru)(ru)(ru)(ru)，壓管(guan)(guan)(guan)器(qi)就松開，于(yu)是(shi)(shi)，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)連同(tong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)(yi)并(bing)向(xiang)(xiang)軋輥(gun)方(fang)向(xiang)(xiang)送(song)(song)去。如果荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)不易(yi)喂入(ru)(ru)(ru)(ru)(ru)軋機(ji)(ji)，就用(yong)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)(ru)(ru)(ru)機(ji)(ji)在(zai)后(hou)面推(tui)(tui)下，以(yi)(yi)幫助荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)喂入(ru)(ru)(ru)(ru)(ru)。當荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)開始(shi)軋制(zhi)時，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)(ru)(ru)(ru)機(ji)(ji)和(he)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)(ru)(ru)機(ji)(ji)便(bian)返回到(dao)初始(shi)位置(zhi)。但是(shi)(shi)，當采用(yong)小直徑芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)軋管(guan)(guan)(guan)時，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)(ru)(ru)(ru)機(ji)(ji)可(ke)(ke)保(bao)留(liu)在(zai)前(qian)(qian)(qian)位，充當導衛，防止芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)抖動。荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)延(yan)伸(shen)后(hou)，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)和(he)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)(yi)起通過軋機(ji)(ji)向(xiang)(xiang)前(qian)(qian)(qian)移動軋制(zhi)終(zhong)了時，后(hou)臺(tai)輥(gun)子升起，將(jiang)毛管(guan)(guan)(guan)及芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)送(song)(song)到(dao)輸(shu)出輥(gun)道。然(ran)后(hou)，從(cong)輸(shu)出輥(gun)送(song)(song)到(dao)脫(tuo)棒(bang)(bang)(bang)(bang)(bang)機(ji)(ji)，將(jiang)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)從(cong)毛管(guan)(guan)(guan)中脫(tuo)出。脫(tuo)棒(bang)(bang)(bang)(bang)(bang)后(hou)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)先冷卻(que)，再(zai)送(song)(song)到(dao)軋管(guan)(guan)(guan)機(ji)(ji)前(qian)(qian)(qian)臺(tai)，以(yi)(yi)備再(zai)用(yong)。荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)則(ze)由輥(gun)道送(song)(song)走，進(jin)行(xing)下一(yi)(yi)步(bu)加工(gong)。采用(yong)全浮(fu)棒(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式時，軋機(ji)(ji)生產率最高，因(yin)此，下一(yi)(yi)根(gen)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)前(qian)(qian)(qian)端實際(ji)上可(ke)(ke)以(yi)(yi)跟在(zai)正在(zai)軋制(zhi)的(de)前(qian)(qian)(qian)一(yi)(yi)根(gen)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)的(de)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)后(hou)面。這是(shi)(shi)可(ke)(ke)能(neng)的(de)，因(yin)為在(zai)前(qian)(qian)(qian)一(yi)(yi)根(gen)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)軋完(wan)以(yi)(yi)前(qian)(qian)(qian)，后(hou)一(yi)(yi)根(gen)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)可(ke)(ke)以(yi)(yi)放在(zai)前(qian)(qian)(qian)臺(tai)上、并(bing)穿(chuan)好(hao)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)。

2. 回(hui)退芯棒(bang)

  回(hui)退芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)方式和浮動(dong)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)一樣使用同一荒管(guan)(guan)(guan)推(tui)人機(ji)(ji)與(yu)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)，但是芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)上加(jia)了一套(tao)裝置(zhi)(zhi)，可(ke)將(jiang)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的(de)后(hou)端固定在芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)上并使芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)回(hui)轉(zhuan)。荒管(guan)(guan)(guan)在前臺的(de)初始(shi)位置(zhi)(zhi)和夾緊與(yu)全浮芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作(zuo)方式一樣。然而，在插入(ru)(ru)(ru)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時，不僅芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)頭部穿(chuan)過(guo)(guo)荒管(guan)(guan)(guan)，而且芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)要穿(chuan)過(guo)(guo)軋(ya)(ya)機(ji)(ji)，伸出軋(ya)(ya)輥(gun)臺肩約3.5m。當芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到達此位置(zhi)(zhi)后(hou)，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開(kai)(kai)始(shi)回(hui)轉(zhuan)，直到荒管(guan)(guan)(guan)接觸軋(ya)(ya)輥(gun)后(hou)一段(duan)時間才停止(zhi)。當芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)到達行程(cheng)終點(dian)時，壓管(guan)(guan)(guan)器松開(kai)(kai)，荒管(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)啟(qi)動(dong)前進。于是，荒管(guan)(guan)(guan)喂入(ru)(ru)(ru)軋(ya)(ya)機(ji)(ji)。軋(ya)(ya)制開(kai)(kai)始(shi)后(hou)，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開(kai)(kai)始(shi)回(hui)退。其回(hui)退速度與(yu)荒管(guan)(guan)(guan)的(de)行程(cheng)長(chang)度及前進速度有關，以便在軋(ya)(ya)制過(guo)(guo)程(cheng)結束，當毛(mao)管(guan)(guan)(guan)離開(kai)(kai)軋(ya)(ya)輥(gun)時，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)正好從(cong)荒管(guan)(guan)(guan)中抽出。見圖6-49。然后(hou)，毛(mao)管(guan)(guan)(guan)從(cong)軋(ya)(ya)機(ji)(ji)運走(zou)，進行下步加(jia)工，而芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速返回(hui)其初始(shi)位置(zhi)(zhi)以備穿(chuan)入(ru)(ru)(ru)下一根(gen)毛(mao)管(guan)(guan)(guan)。

3. 限動芯棒

  限動芯(xin)(xin)棒(bang)(bang)操作法(fa)是全浮芯(xin)(xin)棒(bang)(bang)和(he)回(hui)退(tui)芯(xin)(xin)棒(bang)(bang)操作法(fa)的(de)折(zhe)中方法(fa)。采用這種方法(fa)時(shi)，芯(xin)(xin)棒(bang)(bang)的(de)尾端(duan)固定在(zai)芯(xin)(xin)棒(bang)(bang)推入機上(shang)，并可回(hui)轉(zhuan)。這和(he)回(hui)退(tui)芯(xin)(xin)棒(bang)(bang)操作方式(shi)一樣，不同的(de)是，鋼管(guan)(guan)軋(ya)(ya)制(zhi)時(shi)芯(xin)(xin)棒(bang)(bang)向(xiang)(xiang)(xiang)前(qian)(qian)(qian)移動。在(zai)軋(ya)(ya)制(zhi)結(jie)束(shu)時(shi)，芯(xin)(xin)棒(bang)(bang)從(cong)毛管(guan)(guan)上(shang)脫出。當(dang)荒(huang)(huang)管(guan)(guan)在(zai)前(qian)(qian)(qian)臺被(bei)夾(jia)緊時(shi)，穿入芯(xin)(xin)棒(bang)(bang)，直(zhi)到(dao)芯(xin)(xin)棒(bang)(bang)前(qian)(qian)(qian)端(duan)伸出軋(ya)(ya)輥臺肩約0.3m左右為止。插入芯(xin)(xin)棒(bang)(bang)時(shi)，芯(xin)(xin)棒(bang)(bang)開(kai)始(shi)回(hui)轉(zhuan)，直(zhi)到(dao)荒(huang)(huang)管(guan)(guan)接(jie)觸軋(ya)(ya)輥后一段(duan)時(shi)間才(cai)停(ting)止。芯(xin)(xin)棒(bang)(bang)到(dao)位(wei)后，壓管(guan)(guan)器松(song)開(kai)，荒(huang)(huang)管(guan)(guan)推入機將(jiang)荒(huang)(huang)管(guan)(guan)推向(xiang)(xiang)(xiang)軋(ya)(ya)輥，直(zhi)到(dao)軋(ya)(ya)制(zhi)過程(cheng)開(kai)始(shi)為止。軋(ya)(ya)制(zhi)過程(cheng)中，芯(xin)(xin)捧以(yi)低于毛管(guan)(guan)軸向(xiang)(xiang)(xiang)輸出速(su)度(du)的(de)速(su)度(du)和(he)軋(ya)(ya)件一起前(qian)(qian)(qian)進。軋(ya)(ya)制(zhi)周期結(jie)束(shu)時(shi)，毛管(guan)(guan)從(cong)芯(xin)(xin)棒(bang)(bang)上(shang)脫出，然后，芯(xin)(xin)棒(bang)(bang)高速(su)返回(hui)其(qi)初始(shi)位(wei)置。

  三種芯棒(bang)操(cao)(cao)作方(fang)(fang)式的(de)比較。在采(cai)用(yong)回退(tui)芯棒(bang)與限(xian)動(dong)(dong)芯棒(bang)操(cao)(cao)作方(fang)(fang)式的(de)工廠(chang)，只有生產(chan)D/t小于7.5的(de)鋼管(guan)時(shi)才采(cai)用(yong)回退(tui)芯棒(bang)操(cao)(cao)作方(fang)(fang)式，而當生產(chan)D/t大(da)于7.5的(de)鋼管(guan)時(shi)采(cai)用(yong)限(xian)動(dong)(dong)芯棒(bang)操(cao)(cao)作方(fang)(fang)式。顯(xian)然，采(cai)用(yong)回退(tui)和限(xian)動(dong)(dong)芯棒(bang)操(cao)(cao)作方(fang)(fang)式時(shi)，軋機產(chan)量(liang)比采(cai)用(yong)全浮芯棒(bang)時(shi)低，因(yin)為，下一根荒管(guan)撥入到前臺之前，在用(yong)的(de)芯棒(bang)必須返回其初(chu)始位置。同時(shi)，芯棒(bang)的(de)冷(leng)卻不充分(fen)，芯棒(bang)壽命不長。