目(mu)前(qian)采用的有三種(zhong)芯(xin)棒(bang)(bang)操(cao)作方(fang)式。早期的三輥(gun)軋管機均采用全浮芯(xin)棒(bang)(bang)，即(ji)使(shi)在今(jin)天，仍(reng)有一部(bu)分機組采用全浮芯(xin)棒(bang)(bang)操(cao)作。但是，全浮芯(xin)棒(bang)(bang)操(cao)作方(fang)式有如(ru)下(xia)缺(que)點：

（1）軋制特(te)厚(hou)壁管時不易脫棒；

（2）對各種尺寸的(de)毛管(guan)均需要(yao)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(shi)三種(zhong)不(bu)同芯棒操作方式(shi)的簡述(shu)。

1. 全浮芯(xin)棒

  采用(yong)(yong)全浮芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操作方(fang)式(shi)時(shi)(shi)(shi)，荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)被撥入(ru)(ru)(ru)到(dao)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)前(qian)的(de)(de)人(ren)口臺(tai)，落到(dao)和軋(ya)(ya)機(ji)(ji)(ji)(ji)中心(xin)線(xian)一(yi)致的(de)(de)U形槽里。氣動(dong)壓(ya)管(guan)(guan)(guan)器壓(ya)在(zai)(zai)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)上，將(jiang)(jiang)其(qi)夾緊，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)將(jiang)(jiang)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)穿(chuan)入(ru)(ru)(ru)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)內。一(yi)旦芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)完全穿(chuan)入(ru)(ru)(ru)，壓(ya)管(guan)(guan)(guan)器就松開(kai)，于是，荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)連同芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)一(yi)并(bing)向軋(ya)(ya)輥方(fang)向送(song)去(qu)。如果荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)不(bu)易喂(wei)入(ru)(ru)(ru)軋(ya)(ya)機(ji)(ji)(ji)(ji)，就用(yong)(yong)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)在(zai)(zai)后(hou)(hou)面推下，以(yi)(yi)(yi)幫助荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)喂(wei)入(ru)(ru)(ru)。當(dang)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)開(kai)始(shi)軋(ya)(ya)制時(shi)(shi)(shi)，荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)和芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)便返回到(dao)初始(shi)位置。但是，當(dang)采用(yong)(yong)小(xiao)直徑芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)軋(ya)(ya)管(guan)(guan)(guan)時(shi)(shi)(shi)，荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)機(ji)(ji)(ji)(ji)可(ke)保留在(zai)(zai)前(qian)位，充當(dang)導衛，防止芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)抖動(dong)。荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)延伸后(hou)(hou)，荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)和芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)一(yi)起通過軋(ya)(ya)機(ji)(ji)(ji)(ji)向前(qian)移(yi)動(dong)軋(ya)(ya)制終了時(shi)(shi)(shi)，后(hou)(hou)臺(tai)輥子升起，將(jiang)(jiang)毛管(guan)(guan)(guan)及(ji)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)送(song)到(dao)輸出輥道。然(ran)后(hou)(hou)，從(cong)輸出輥送(song)到(dao)脫棒(bang)(bang)(bang)(bang)(bang)(bang)機(ji)(ji)(ji)(ji)，將(jiang)(jiang)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)從(cong)毛管(guan)(guan)(guan)中脫出。脫棒(bang)(bang)(bang)(bang)(bang)(bang)后(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)先冷卻(que)，再送(song)到(dao)軋(ya)(ya)管(guan)(guan)(guan)機(ji)(ji)(ji)(ji)前(qian)臺(tai)，以(yi)(yi)(yi)備再用(yong)(yong)。荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)則由輥道送(song)走，進行(xing)下一(yi)步加工。采用(yong)(yong)全浮棒(bang)(bang)(bang)(bang)(bang)(bang)操作方(fang)式(shi)時(shi)(shi)(shi)，軋(ya)(ya)機(ji)(ji)(ji)(ji)生產(chan)率最高，因(yin)此，下一(yi)根(gen)(gen)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)的(de)(de)前(qian)端實際上可(ke)以(yi)(yi)(yi)跟在(zai)(zai)正在(zai)(zai)軋(ya)(ya)制的(de)(de)前(qian)一(yi)根(gen)(gen)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)的(de)(de)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)的(de)(de)后(hou)(hou)面。這(zhe)是可(ke)能的(de)(de)，因(yin)為在(zai)(zai)前(qian)一(yi)根(gen)(gen)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)軋(ya)(ya)完以(yi)(yi)(yi)前(qian)，后(hou)(hou)一(yi)根(gen)(gen)荒(huang)(huang)(huang)(huang)(huang)管(guan)(guan)(guan)可(ke)以(yi)(yi)(yi)放在(zai)(zai)前(qian)臺(tai)上、并(bing)穿(chuan)好芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)。

2. 回退(tui)芯棒

  回退(tui)芯(xin)(xin)棒(bang)(bang)(bang)操作方式和浮動芯(xin)(xin)棒(bang)(bang)(bang)一樣(yang)使用同一荒(huang)(huang)管(guan)(guan)(guan)推(tui)(tui)(tui)(tui)人機與芯(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)(tui)入(ru)機，但是芯(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)(tui)入(ru)機上(shang)(shang)加了一套裝(zhuang)置，可將芯(xin)(xin)棒(bang)(bang)(bang)的(de)(de)后(hou)端固定在(zai)(zai)芯(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)(tui)入(ru)機上(shang)(shang)并使芯(xin)(xin)棒(bang)(bang)(bang)回轉。荒(huang)(huang)管(guan)(guan)(guan)在(zai)(zai)前臺的(de)(de)初(chu)始位置和夾(jia)緊(jin)與全浮芯(xin)(xin)棒(bang)(bang)(bang)操作方式一樣(yang)。然而(er)，在(zai)(zai)插入(ru)芯(xin)(xin)棒(bang)(bang)(bang)時，不僅芯(xin)(xin)棒(bang)(bang)(bang)頭部(bu)穿(chuan)過(guo)荒(huang)(huang)管(guan)(guan)(guan)，而(er)且芯(xin)(xin)棒(bang)(bang)(bang)要(yao)穿(chuan)過(guo)軋機，伸出軋輥(gun)(gun)臺肩約3.5m。當芯(xin)(xin)棒(bang)(bang)(bang)到(dao)達(da)此位置后(hou)，芯(xin)(xin)棒(bang)(bang)(bang)開始回轉，直到(dao)荒(huang)(huang)管(guan)(guan)(guan)接觸軋輥(gun)(gun)后(hou)一段時間(jian)才停止。當芯(xin)(xin)棒(bang)(bang)(bang)推(tui)(tui)(tui)(tui)入(ru)機到(dao)達(da)行(xing)程(cheng)終點時，壓管(guan)(guan)(guan)器松開，荒(huang)(huang)管(guan)(guan)(guan)推(tui)(tui)(tui)(tui)入(ru)機啟動前進(jin)(jin)。于是，荒(huang)(huang)管(guan)(guan)(guan)喂入(ru)軋機。軋制(zhi)開始后(hou)，芯(xin)(xin)棒(bang)(bang)(bang)開始回退(tui)。其回退(tui)速(su)(su)度與荒(huang)(huang)管(guan)(guan)(guan)的(de)(de)行(xing)程(cheng)長度及前進(jin)(jin)速(su)(su)度有關，以便在(zai)(zai)軋制(zhi)過(guo)程(cheng)結(jie)束，當毛管(guan)(guan)(guan)離開軋輥(gun)(gun)時，芯(xin)(xin)棒(bang)(bang)(bang)正(zheng)好從荒(huang)(huang)管(guan)(guan)(guan)中(zhong)抽出。見圖(tu)6-49。然后(hou)，毛管(guan)(guan)(guan)從軋機運走，進(jin)(jin)行(xing)下步(bu)加工(gong)，而(er)芯(xin)(xin)棒(bang)(bang)(bang)高速(su)(su)返(fan)回其初(chu)始位置以備(bei)穿(chuan)入(ru)下一根(gen)毛管(guan)(guan)(guan)。

3. 限動芯(xin)棒

  限(xian)動芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操(cao)作法(fa)是全(quan)浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)和回(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操(cao)作法(fa)的折中(zhong)方(fang)法(fa)。采用這(zhe)種方(fang)法(fa)時(shi)(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)的尾端固定在(zai)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)推(tui)入機上，并(bing)可回(hui)轉。這(zhe)和回(hui)退(tui)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)操(cao)作方(fang)式一樣，不同(tong)的是，鋼管(guan)(guan)(guan)軋(ya)(ya)制(zhi)時(shi)(shi)(shi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)向前移動。在(zai)軋(ya)(ya)制(zhi)結(jie)束(shu)時(shi)(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)從(cong)(cong)毛管(guan)(guan)(guan)上脫出(chu)(chu)。當荒(huang)管(guan)(guan)(guan)在(zai)前臺(tai)被(bei)夾緊時(shi)(shi)(shi)，穿入芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)，直到(dao)(dao)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)前端伸出(chu)(chu)軋(ya)(ya)輥臺(tai)肩約0.3m左右為(wei)(wei)止(zhi)。插入芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)時(shi)(shi)(shi)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(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)輥后一段時(shi)(shi)(shi)間才停止(zhi)。芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)到(dao)(dao)位后，壓(ya)管(guan)(guan)(guan)器松開，荒(huang)管(guan)(guan)(guan)推(tui)入機將荒(huang)管(guan)(guan)(guan)推(tui)向軋(ya)(ya)輥，直到(dao)(dao)軋(ya)(ya)制(zhi)過程開始(shi)為(wei)(wei)止(zhi)。軋(ya)(ya)制(zhi)過程中(zhong)，芯(xin)(xin)(xin)(xin)捧以(yi)低于毛管(guan)(guan)(guan)軸向輸出(chu)(chu)速度的速度和軋(ya)(ya)件一起前進。軋(ya)(ya)制(zhi)周期結(jie)束(shu)時(shi)(shi)(shi)，毛管(guan)(guan)(guan)從(cong)(cong)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)上脫出(chu)(chu)，然后，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)(bang)高速返回(hui)其初始(shi)位置。

  三種芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式(shi)的(de)比(bi)較。在采(cai)(cai)用(yong)(yong)(yong)回(hui)退芯(xin)(xin)棒(bang)(bang)(bang)與限動(dong)芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式(shi)的(de)工廠，只有生產(chan)D/t小于7.5的(de)鋼(gang)(gang)管(guan)時(shi)才采(cai)(cai)用(yong)(yong)(yong)回(hui)退芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式(shi)，而當生產(chan)D/t大于7.5的(de)鋼(gang)(gang)管(guan)時(shi)采(cai)(cai)用(yong)(yong)(yong)限動(dong)芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式(shi)。顯然，采(cai)(cai)用(yong)(yong)(yong)回(hui)退和(he)限動(dong)芯(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式(shi)時(shi)，軋機產(chan)量比(bi)采(cai)(cai)用(yong)(yong)(yong)全(quan)浮(fu)芯(xin)(xin)棒(bang)(bang)(bang)時(shi)低，因為，下一(yi)根荒管(guan)撥入到前臺(tai)之前，在用(yong)(yong)(yong)的(de)芯(xin)(xin)棒(bang)(bang)(bang)必(bi)須返回(hui)其(qi)初始位置(zhi)。同時(shi)，芯(xin)(xin)棒(bang)(bang)(bang)的(de)冷卻不充分，芯(xin)(xin)棒(bang)(bang)(bang)壽命不長。