目前采(cai)(cai)用的有(you)(you)三種芯(xin)棒(bang)操作方式。早(zao)期的三輥軋管機(ji)均采(cai)(cai)用全(quan)浮(fu)芯(xin)棒(bang)，即使在今(jin)天(tian)，仍有(you)(you)一(yi)部分機(ji)組采(cai)(cai)用全(quan)浮(fu)芯(xin)棒(bang)操作。但是，全(quan)浮(fu)芯(xin)棒(bang)操作方式有(you)(you)如下缺點(dian)：

（1）軋制特(te)厚壁(bi)管時不易脫棒；

（2）對各種尺寸(cun)的毛管(guan)均(jun)需(xu)要(yao)配(pei)置再加熱(re)爐；

（3）軋制薄(bo)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(yi)下(xia)是三種不(bu)同(tong)芯棒操作方式的簡述。

1. 全浮芯棒

  采(cai)用全(quan)浮(fu)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)操作(zuo)方(fang)式(shi)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)被(bei)撥入(ru)(ru)到(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)前(qian)的(de)(de)(de)人口臺(tai)，落到(dao)和(he)軋(ya)機(ji)(ji)中心線(xian)一致的(de)(de)(de)U形槽里。氣動(dong)壓管(guan)(guan)(guan)(guan)器壓在(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)上，將(jiang)其夾緊，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)機(ji)(ji)將(jiang)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)穿(chuan)入(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)內。一旦芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)完(wan)全(quan)穿(chuan)入(ru)(ru)，壓管(guan)(guan)(guan)(guan)器就松(song)開(kai)，于(yu)是(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)連同芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)一并向軋(ya)輥(gun)方(fang)向送去。如(ru)果荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)不易喂(wei)入(ru)(ru)軋(ya)機(ji)(ji)，就用荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)在(zai)后(hou)(hou)(hou)面推(tui)(tui)下(xia)，以(yi)(yi)幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)喂(wei)入(ru)(ru)。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)開(kai)始(shi)軋(ya)制時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)和(he)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)推(tui)(tui)入(ru)(ru)機(ji)(ji)便返回到(dao)初始(shi)位置。但是(shi)，當(dang)采(cai)用小直徑芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)軋(ya)管(guan)(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)(tui)入(ru)(ru)機(ji)(ji)可(ke)保留在(zai)前(qian)位，充當(dang)導衛，防止(zhi)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)抖動(dong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)延伸后(hou)(hou)(hou)，荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)和(he)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)一起通過(guo)軋(ya)機(ji)(ji)向前(qian)移動(dong)軋(ya)制終(zhong)了時(shi)，后(hou)(hou)(hou)臺(tai)輥(gun)子(zi)升起，將(jiang)毛管(guan)(guan)(guan)(guan)及(ji)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)送到(dao)輸出輥(gun)道。然(ran)后(hou)(hou)(hou)，從輸出輥(gun)送到(dao)脫棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)機(ji)(ji)，將(jiang)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)從毛管(guan)(guan)(guan)(guan)中脫出。脫棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)后(hou)(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)先(xian)冷(leng)卻，再送到(dao)軋(ya)管(guan)(guan)(guan)(guan)機(ji)(ji)前(qian)臺(tai)，以(yi)(yi)備再用。荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)則(ze)由(you)輥(gun)道送走(zou)，進行(xing)下(xia)一步加工(gong)。采(cai)用全(quan)浮(fu)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)操作(zuo)方(fang)式(shi)時(shi)，軋(ya)機(ji)(ji)生產率最高，因(yin)此，下(xia)一根(gen)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)的(de)(de)(de)前(qian)端實際上可(ke)以(yi)(yi)跟在(zai)正在(zai)軋(ya)制的(de)(de)(de)前(qian)一根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)的(de)(de)(de)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)的(de)(de)(de)后(hou)(hou)(hou)面。這是(shi)可(ke)能的(de)(de)(de)，因(yin)為在(zai)前(qian)一根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)軋(ya)完(wan)以(yi)(yi)前(qian)，后(hou)(hou)(hou)一根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)(guan)可(ke)以(yi)(yi)放在(zai)前(qian)臺(tai)上、并穿(chuan)好芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)(bang)(bang)。

2. 回退(tui)芯棒

  回(hui)(hui)退芯(xin)(xin)棒(bang)(bang)(bang)操作(zuo)方式(shi)和浮動(dong)芯(xin)(xin)棒(bang)(bang)(bang)一樣使用同一荒(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)人機(ji)(ji)與(yu)芯(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)機(ji)(ji)，但是(shi)(shi)芯(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)機(ji)(ji)上(shang)加了一套(tao)裝置(zhi)(zhi)，可將(jiang)芯(xin)(xin)棒(bang)(bang)(bang)的(de)后(hou)(hou)端固定(ding)在(zai)芯(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)機(ji)(ji)上(shang)并(bing)使芯(xin)(xin)棒(bang)(bang)(bang)回(hui)(hui)轉(zhuan)。荒(huang)(huang)管(guan)(guan)(guan)(guan)在(zai)前臺的(de)初(chu)始位置(zhi)(zhi)和夾(jia)緊與(yu)全浮芯(xin)(xin)棒(bang)(bang)(bang)操作(zuo)方式(shi)一樣。然而，在(zai)插入(ru)(ru)芯(xin)(xin)棒(bang)(bang)(bang)時，不僅芯(xin)(xin)棒(bang)(bang)(bang)頭部穿過荒(huang)(huang)管(guan)(guan)(guan)(guan)，而且芯(xin)(xin)棒(bang)(bang)(bang)要穿過軋(ya)機(ji)(ji)，伸出軋(ya)輥(gun)臺肩約3.5m。當(dang)芯(xin)(xin)棒(bang)(bang)(bang)到(dao)達(da)此位置(zhi)(zhi)后(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)開(kai)(kai)始回(hui)(hui)轉(zhuan)，直到(dao)荒(huang)(huang)管(guan)(guan)(guan)(guan)接觸軋(ya)輥(gun)后(hou)(hou)一段時間才(cai)停(ting)止。當(dang)芯(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)機(ji)(ji)到(dao)達(da)行程終點(dian)時，壓(ya)管(guan)(guan)(guan)(guan)器松(song)開(kai)(kai)，荒(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)機(ji)(ji)啟動(dong)前進。于是(shi)(shi)，荒(huang)(huang)管(guan)(guan)(guan)(guan)喂入(ru)(ru)軋(ya)機(ji)(ji)。軋(ya)制(zhi)開(kai)(kai)始后(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)開(kai)(kai)始回(hui)(hui)退。其(qi)(qi)回(hui)(hui)退速度與(yu)荒(huang)(huang)管(guan)(guan)(guan)(guan)的(de)行程長(chang)度及前進速度有(you)關(guan)，以便在(zai)軋(ya)制(zhi)過程結束，當(dang)毛管(guan)(guan)(guan)(guan)離開(kai)(kai)軋(ya)輥(gun)時，芯(xin)(xin)棒(bang)(bang)(bang)正好從(cong)荒(huang)(huang)管(guan)(guan)(guan)(guan)中(zhong)抽出。見圖6-49。然后(hou)(hou)，毛管(guan)(guan)(guan)(guan)從(cong)軋(ya)機(ji)(ji)運走(zou)，進行下步加工，而芯(xin)(xin)棒(bang)(bang)(bang)高(gao)速返回(hui)(hui)其(qi)(qi)初(chu)始位置(zhi)(zhi)以備穿入(ru)(ru)下一根毛管(guan)(guan)(guan)(guan)。

3. 限動芯棒

  限動芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作法(fa)是全(quan)浮芯(xin)(xin)棒(bang)(bang)(bang)和回(hui)(hui)退(tui)芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作法(fa)的(de)折中方(fang)法(fa)。采用這種(zhong)方(fang)法(fa)時(shi)(shi)(shi)，芯(xin)(xin)棒(bang)(bang)(bang)的(de)尾端(duan)固定(ding)在芯(xin)(xin)棒(bang)(bang)(bang)推入(ru)機上(shang)(shang)，并可(ke)回(hui)(hui)轉。這和回(hui)(hui)退(tui)芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式(shi)一(yi)樣，不同的(de)是，鋼管(guan)(guan)(guan)軋制時(shi)(shi)(shi)芯(xin)(xin)棒(bang)(bang)(bang)向(xiang)前(qian)移(yi)動。在軋制結(jie)束時(shi)(shi)(shi)，芯(xin)(xin)棒(bang)(bang)(bang)從(cong)毛管(guan)(guan)(guan)上(shang)(shang)脫(tuo)出(chu)。當荒管(guan)(guan)(guan)在前(qian)臺(tai)被夾緊時(shi)(shi)(shi)，穿入(ru)芯(xin)(xin)棒(bang)(bang)(bang)，直到(dao)(dao)芯(xin)(xin)棒(bang)(bang)(bang)前(qian)端(duan)伸(shen)出(chu)軋輥(gun)臺(tai)肩約(yue)0.3m左(zuo)右為(wei)止(zhi)(zhi)。插入(ru)芯(xin)(xin)棒(bang)(bang)(bang)時(shi)(shi)(shi)，芯(xin)(xin)棒(bang)(bang)(bang)開始回(hui)(hui)轉，直到(dao)(dao)荒管(guan)(guan)(guan)接觸軋輥(gun)后一(yi)段時(shi)(shi)(shi)間(jian)才停止(zhi)(zhi)。芯(xin)(xin)棒(bang)(bang)(bang)到(dao)(dao)位后，壓管(guan)(guan)(guan)器松(song)開，荒管(guan)(guan)(guan)推入(ru)機將荒管(guan)(guan)(guan)推向(xiang)軋輥(gun)，直到(dao)(dao)軋制過(guo)程開始為(wei)止(zhi)(zhi)。軋制過(guo)程中，芯(xin)(xin)捧以低(di)于毛管(guan)(guan)(guan)軸向(xiang)輸出(chu)速(su)度的(de)速(su)度和軋件一(yi)起前(qian)進。軋制周期結(jie)束時(shi)(shi)(shi)，毛管(guan)(guan)(guan)從(cong)芯(xin)(xin)棒(bang)(bang)(bang)上(shang)(shang)脫(tuo)出(chu)，然(ran)后，芯(xin)(xin)棒(bang)(bang)(bang)高(gao)速(su)返回(hui)(hui)其初始位置。

  三種(zhong)芯(xin)(xin)棒(bang)操(cao)(cao)作(zuo)方式的(de)比(bi)較。在采用(yong)(yong)(yong)回退芯(xin)(xin)棒(bang)與(yu)限動芯(xin)(xin)棒(bang)操(cao)(cao)作(zuo)方式的(de)工廠，只有生產(chan)D/t小(xiao)于(yu)7.5的(de)鋼(gang)管時(shi)(shi)才(cai)采用(yong)(yong)(yong)回退芯(xin)(xin)棒(bang)操(cao)(cao)作(zuo)方式，而當生產(chan)D/t大于(yu)7.5的(de)鋼(gang)管時(shi)(shi)采用(yong)(yong)(yong)限動芯(xin)(xin)棒(bang)操(cao)(cao)作(zuo)方式。顯然，采用(yong)(yong)(yong)回退和限動芯(xin)(xin)棒(bang)操(cao)(cao)作(zuo)方式時(shi)(shi)，軋機(ji)產(chan)量比(bi)采用(yong)(yong)(yong)全(quan)浮芯(xin)(xin)棒(bang)時(shi)(shi)低，因為，下(xia)一根荒管撥入到前(qian)臺之前(qian)，在用(yong)(yong)(yong)的(de)芯(xin)(xin)棒(bang)必須返(fan)回其初(chu)始位置。同時(shi)(shi)，芯(xin)(xin)棒(bang)的(de)冷卻(que)不(bu)充分(fen)，芯(xin)(xin)棒(bang)壽命不(bu)長。