目前采用(yong)(yong)(yong)的有三種(zhong)芯棒(bang)(bang)操(cao)(cao)作方(fang)式。早期的三輥軋管機(ji)均采用(yong)(yong)(yong)全(quan)浮(fu)(fu)芯棒(bang)(bang)，即使在今(jin)天(tian)，仍有一(yi)部分機(ji)組采用(yong)(yong)(yong)全(quan)浮(fu)(fu)芯棒(bang)(bang)操(cao)(cao)作。但是，全(quan)浮(fu)(fu)芯棒(bang)(bang)操(cao)(cao)作方(fang)式有如下缺點：

（1）軋制特厚壁(bi)管時不易脫棒；

（2）對各種尺寸的毛管均(jun)需(xu)要(yao)配置再加熱爐(lu)；

（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。

以下是三種不同芯棒操作方式的簡述(shu)。

1. 全浮(fu)芯棒

  采(cai)用全浮芯(xin)(xin)棒(bang)(bang)(bang)操作方式(shi)時(shi)，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)被撥入(ru)(ru)(ru)到(dao)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)前(qian)(qian)(qian)的(de)(de)人口臺，落到(dao)和(he)軋(ya)(ya)(ya)機(ji)(ji)(ji)(ji)中心線(xian)一(yi)(yi)(yi)致的(de)(de)U形槽里。氣動壓管(guan)(guan)(guan)(guan)器壓在(zai)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)上，將其夾緊，芯(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)將芯(xin)(xin)棒(bang)(bang)(bang)穿入(ru)(ru)(ru)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)內。一(yi)(yi)(yi)旦芯(xin)(xin)棒(bang)(bang)(bang)完全穿入(ru)(ru)(ru)，壓管(guan)(guan)(guan)(guan)器就松開，于是，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)連同芯(xin)(xin)棒(bang)(bang)(bang)一(yi)(yi)(yi)并(bing)向軋(ya)(ya)(ya)輥(gun)方向送(song)(song)去。如果荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)不(bu)易喂入(ru)(ru)(ru)軋(ya)(ya)(ya)機(ji)(ji)(ji)(ji)，就用荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)在(zai)后面推(tui)下(xia)(xia)，以幫助(zhu)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)喂入(ru)(ru)(ru)。當(dang)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)開始(shi)軋(ya)(ya)(ya)制時(shi)，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)和(he)芯(xin)(xin)棒(bang)(bang)(bang)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)便返(fan)回到(dao)初始(shi)位置。但是，當(dang)采(cai)用小直徑芯(xin)(xin)棒(bang)(bang)(bang)軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)推(tui)入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)可(ke)(ke)保留在(zai)前(qian)(qian)(qian)位，充(chong)當(dang)導衛，防(fang)止芯(xin)(xin)棒(bang)(bang)(bang)抖動。荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)延(yan)伸后，荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)和(he)芯(xin)(xin)棒(bang)(bang)(bang)一(yi)(yi)(yi)起通過軋(ya)(ya)(ya)機(ji)(ji)(ji)(ji)向前(qian)(qian)(qian)移動軋(ya)(ya)(ya)制終了(le)時(shi)，后臺輥(gun)子升起，將毛(mao)管(guan)(guan)(guan)(guan)及芯(xin)(xin)棒(bang)(bang)(bang)送(song)(song)到(dao)輸(shu)出輥(gun)道(dao)。然后，從輸(shu)出輥(gun)送(song)(song)到(dao)脫棒(bang)(bang)(bang)機(ji)(ji)(ji)(ji)，將芯(xin)(xin)棒(bang)(bang)(bang)從毛(mao)管(guan)(guan)(guan)(guan)中脫出。脫棒(bang)(bang)(bang)后，芯(xin)(xin)棒(bang)(bang)(bang)先冷卻，再(zai)送(song)(song)到(dao)軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)機(ji)(ji)(ji)(ji)前(qian)(qian)(qian)臺，以備再(zai)用。荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)則由輥(gun)道(dao)送(song)(song)走，進行下(xia)(xia)一(yi)(yi)(yi)步(bu)加工(gong)。采(cai)用全浮棒(bang)(bang)(bang)操作方式(shi)時(shi)，軋(ya)(ya)(ya)機(ji)(ji)(ji)(ji)生產(chan)率(lv)最(zui)高(gao)，因此，下(xia)(xia)一(yi)(yi)(yi)根(gen)芯(xin)(xin)棒(bang)(bang)(bang)的(de)(de)前(qian)(qian)(qian)端(duan)實際上可(ke)(ke)以跟在(zai)正在(zai)軋(ya)(ya)(ya)制的(de)(de)前(qian)(qian)(qian)一(yi)(yi)(yi)根(gen)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)的(de)(de)芯(xin)(xin)棒(bang)(bang)(bang)的(de)(de)后面。這是可(ke)(ke)能的(de)(de)，因為在(zai)前(qian)(qian)(qian)一(yi)(yi)(yi)根(gen)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)軋(ya)(ya)(ya)完以前(qian)(qian)(qian)，后一(yi)(yi)(yi)根(gen)荒(huang)(huang)(huang)(huang)管(guan)(guan)(guan)(guan)可(ke)(ke)以放在(zai)前(qian)(qian)(qian)臺上、并(bing)穿好芯(xin)(xin)棒(bang)(bang)(bang)。

2. 回退芯棒

  回(hui)退芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作方式和(he)浮(fu)動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)一(yi)(yi)樣(yang)(yang)使用同(tong)一(yi)(yi)荒(huang)(huang)(huang)管(guan)(guan)推人機(ji)(ji)與芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入機(ji)(ji)，但是(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入機(ji)(ji)上(shang)加了一(yi)(yi)套(tao)裝置(zhi)(zhi)，可將芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的后端固定在(zai)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入機(ji)(ji)上(shang)并使芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)回(hui)轉。荒(huang)(huang)(huang)管(guan)(guan)在(zai)前(qian)臺的初(chu)始位(wei)置(zhi)(zhi)和(he)夾緊與全浮(fu)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作方式一(yi)(yi)樣(yang)(yang)。然而(er)，在(zai)插入芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)時(shi)(shi)，不僅芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)頭部(bu)穿(chuan)過(guo)荒(huang)(huang)(huang)管(guan)(guan)，而(er)且(qie)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)要穿(chuan)過(guo)軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)，伸出(chu)軋(ya)(ya)(ya)(ya)(ya)輥臺肩約3.5m。當芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)到達此位(wei)置(zhi)(zhi)后，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)始回(hui)轉，直(zhi)到荒(huang)(huang)(huang)管(guan)(guan)接(jie)觸軋(ya)(ya)(ya)(ya)(ya)輥后一(yi)(yi)段時(shi)(shi)間才停止。當芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入機(ji)(ji)到達行程(cheng)終點時(shi)(shi)，壓管(guan)(guan)器松開(kai)，荒(huang)(huang)(huang)管(guan)(guan)推入機(ji)(ji)啟動前(qian)進。于(yu)是(shi)，荒(huang)(huang)(huang)管(guan)(guan)喂入軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)。軋(ya)(ya)(ya)(ya)(ya)制開(kai)始后，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)始回(hui)退。其回(hui)退速度與荒(huang)(huang)(huang)管(guan)(guan)的行程(cheng)長度及前(qian)進速度有(you)關，以便(bian)在(zai)軋(ya)(ya)(ya)(ya)(ya)制過(guo)程(cheng)結(jie)束，當毛管(guan)(guan)離開(kai)軋(ya)(ya)(ya)(ya)(ya)輥時(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)正好(hao)從(cong)荒(huang)(huang)(huang)管(guan)(guan)中(zhong)抽出(chu)。見圖6-49。然后，毛管(guan)(guan)從(cong)軋(ya)(ya)(ya)(ya)(ya)機(ji)(ji)運走，進行下步加工，而(er)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)高(gao)速返回(hui)其初(chu)始位(wei)置(zhi)(zhi)以備穿(chuan)入下一(yi)(yi)根毛管(guan)(guan)。

3. 限(xian)動芯(xin)棒

  限動芯(xin)(xin)(xin)棒(bang)(bang)操(cao)作法是全浮芯(xin)(xin)(xin)棒(bang)(bang)和(he)(he)回退芯(xin)(xin)(xin)棒(bang)(bang)操(cao)作法的折中(zhong)方法。采用這(zhe)種方法時(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)的尾端固(gu)定在芯(xin)(xin)(xin)棒(bang)(bang)推(tui)(tui)入(ru)(ru)(ru)機上(shang)，并可回轉。這(zhe)和(he)(he)回退芯(xin)(xin)(xin)棒(bang)(bang)操(cao)作方式一樣，不同的是，鋼管(guan)軋(ya)(ya)制(zhi)時(shi)(shi)芯(xin)(xin)(xin)棒(bang)(bang)向前(qian)移動。在軋(ya)(ya)制(zhi)結(jie)束時(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)從毛(mao)管(guan)上(shang)脫出(chu)(chu)。當荒管(guan)在前(qian)臺被夾(jia)緊時(shi)(shi)，穿入(ru)(ru)(ru)芯(xin)(xin)(xin)棒(bang)(bang)，直(zhi)到芯(xin)(xin)(xin)棒(bang)(bang)前(qian)端伸出(chu)(chu)軋(ya)(ya)輥臺肩約0.3m左(zuo)右(you)為(wei)止。插入(ru)(ru)(ru)芯(xin)(xin)(xin)棒(bang)(bang)時(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)開始(shi)回轉，直(zhi)到荒管(guan)接觸(chu)軋(ya)(ya)輥后(hou)一段時(shi)(shi)間才停(ting)止。芯(xin)(xin)(xin)棒(bang)(bang)到位后(hou)，壓管(guan)器松開，荒管(guan)推(tui)(tui)入(ru)(ru)(ru)機將荒管(guan)推(tui)(tui)向軋(ya)(ya)輥，直(zhi)到軋(ya)(ya)制(zhi)過(guo)程開始(shi)為(wei)止。軋(ya)(ya)制(zhi)過(guo)程中(zhong)，芯(xin)(xin)(xin)捧(peng)以低于毛(mao)管(guan)軸向輸出(chu)(chu)速(su)度的速(su)度和(he)(he)軋(ya)(ya)件一起前(qian)進。軋(ya)(ya)制(zhi)周期結(jie)束時(shi)(shi)，毛(mao)管(guan)從芯(xin)(xin)(xin)棒(bang)(bang)上(shang)脫出(chu)(chu)，然(ran)后(hou)，芯(xin)(xin)(xin)棒(bang)(bang)高速(su)返(fan)回其初始(shi)位置。

  三種芯(xin)(xin)棒(bang)操(cao)(cao)(cao)作(zuo)方式(shi)的(de)比較(jiao)。在采(cai)用(yong)回(hui)退芯(xin)(xin)棒(bang)與限動(dong)芯(xin)(xin)棒(bang)操(cao)(cao)(cao)作(zuo)方式(shi)的(de)工廠，只有生(sheng)產(chan)D/t小(xiao)于7.5的(de)鋼管時(shi)(shi)才采(cai)用(yong)回(hui)退芯(xin)(xin)棒(bang)操(cao)(cao)(cao)作(zuo)方式(shi)，而當生(sheng)產(chan)D/t大于7.5的(de)鋼管時(shi)(shi)采(cai)用(yong)限動(dong)芯(xin)(xin)棒(bang)操(cao)(cao)(cao)作(zuo)方式(shi)。顯然，采(cai)用(yong)回(hui)退和限動(dong)芯(xin)(xin)棒(bang)操(cao)(cao)(cao)作(zuo)方式(shi)時(shi)(shi)，軋機產(chan)量比采(cai)用(yong)全浮芯(xin)(xin)棒(bang)時(shi)(shi)低(di)，因(yin)為，下(xia)一根荒管撥入到前臺(tai)之前，在用(yong)的(de)芯(xin)(xin)棒(bang)必須返回(hui)其初始位置。同(tong)時(shi)(shi)，芯(xin)(xin)棒(bang)的(de)冷卻不充分(fen)，芯(xin)(xin)棒(bang)壽命不長(chang)。