目(mu)前采用(yong)的有(you)三種芯(xin)棒(bang)操作方式。早期的三輥軋管機(ji)(ji)均采用(yong)全浮芯(xin)棒(bang)，即使在今(jin)天(tian)，仍有(you)一部分機(ji)(ji)組采用(yong)全浮芯(xin)棒(bang)操作。但是，全浮芯(xin)棒(bang)操作方式有(you)如(ru)下(xia)缺點(dian)：

（1）軋制特(te)厚壁(bi)管時不易(yi)脫棒；

（2）對(dui)各種尺寸的(de)毛(mao)管均需要配(pei)置(zhi)再加熱(re)爐；

（3）軋制薄壁(bi)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(san)種(zhong)不同芯棒操(cao)作方(fang)式的簡述。

1. 全浮芯棒

  采用(yong)全(quan)浮芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作方(fang)式(shi)時，荒(huang)(huang)管(guan)(guan)(guan)被撥入(ru)(ru)(ru)(ru)到(dao)荒(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)前(qian)(qian)(qian)的(de)人口臺(tai)，落到(dao)和(he)軋(ya)機(ji)(ji)中心線一(yi)(yi)致的(de)U形槽里。氣動壓(ya)管(guan)(guan)(guan)器(qi)壓(ya)在荒(huang)(huang)管(guan)(guan)(guan)上(shang)，將(jiang)(jiang)其夾緊，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)(ru)機(ji)(ji)將(jiang)(jiang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)穿(chuan)入(ru)(ru)(ru)(ru)荒(huang)(huang)管(guan)(guan)(guan)內。一(yi)(yi)旦芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)完全(quan)穿(chuan)入(ru)(ru)(ru)(ru)，壓(ya)管(guan)(guan)(guan)器(qi)就(jiu)松開(kai)，于是，荒(huang)(huang)管(guan)(guan)(guan)連同芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)一(yi)(yi)并向(xiang)軋(ya)輥方(fang)向(xiang)送去。如果荒(huang)(huang)管(guan)(guan)(guan)不易喂入(ru)(ru)(ru)(ru)軋(ya)機(ji)(ji)，就(jiu)用(yong)荒(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)在后(hou)(hou)(hou)面推下，以(yi)(yi)(yi)幫助荒(huang)(huang)管(guan)(guan)(guan)喂入(ru)(ru)(ru)(ru)。當荒(huang)(huang)管(guan)(guan)(guan)開(kai)始(shi)軋(ya)制(zhi)時，荒(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)和(he)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入(ru)(ru)(ru)(ru)機(ji)(ji)便(bian)返回(hui)到(dao)初始(shi)位(wei)置(zhi)。但(dan)是，當采用(yong)小直(zhi)徑芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)軋(ya)管(guan)(guan)(guan)時，荒(huang)(huang)管(guan)(guan)(guan)推入(ru)(ru)(ru)(ru)機(ji)(ji)可保留(liu)在前(qian)(qian)(qian)位(wei)，充當導衛，防止(zhi)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)抖動。荒(huang)(huang)管(guan)(guan)(guan)延伸后(hou)(hou)(hou)，荒(huang)(huang)管(guan)(guan)(guan)和(he)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)一(yi)(yi)起通過軋(ya)機(ji)(ji)向(xiang)前(qian)(qian)(qian)移動軋(ya)制(zhi)終(zhong)了時，后(hou)(hou)(hou)臺(tai)輥子升起，將(jiang)(jiang)毛管(guan)(guan)(guan)及芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)送到(dao)輸出(chu)輥道(dao)(dao)。然后(hou)(hou)(hou)，從輸出(chu)輥送到(dao)脫(tuo)(tuo)棒(bang)(bang)(bang)(bang)機(ji)(ji)，將(jiang)(jiang)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)從毛管(guan)(guan)(guan)中脫(tuo)(tuo)出(chu)。脫(tuo)(tuo)棒(bang)(bang)(bang)(bang)后(hou)(hou)(hou)，芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)先冷卻，再送到(dao)軋(ya)管(guan)(guan)(guan)機(ji)(ji)前(qian)(qian)(qian)臺(tai)，以(yi)(yi)(yi)備再用(yong)。荒(huang)(huang)管(guan)(guan)(guan)則由輥道(dao)(dao)送走(zou)，進行下一(yi)(yi)步(bu)加工。采用(yong)全(quan)浮棒(bang)(bang)(bang)(bang)操作方(fang)式(shi)時，軋(ya)機(ji)(ji)生產(chan)率最高，因此，下一(yi)(yi)根芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的(de)前(qian)(qian)(qian)端實(shi)際(ji)上(shang)可以(yi)(yi)(yi)跟在正在軋(ya)制(zhi)的(de)前(qian)(qian)(qian)一(yi)(yi)根荒(huang)(huang)管(guan)(guan)(guan)的(de)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的(de)后(hou)(hou)(hou)面。這是可能的(de)，因為在前(qian)(qian)(qian)一(yi)(yi)根荒(huang)(huang)管(guan)(guan)(guan)軋(ya)完以(yi)(yi)(yi)前(qian)(qian)(qian)，后(hou)(hou)(hou)一(yi)(yi)根荒(huang)(huang)管(guan)(guan)(guan)可以(yi)(yi)(yi)放在前(qian)(qian)(qian)臺(tai)上(shang)、并穿(chuan)好(hao)芯(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)。

2. 回退(tui)芯棒

  回(hui)退(tui)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方式和(he)(he)浮(fu)動(dong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)一樣使用同一荒(huang)(huang)管(guan)(guan)(guan)推人機(ji)(ji)與芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入(ru)機(ji)(ji)，但是(shi)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入(ru)機(ji)(ji)上加了一套裝置(zhi)(zhi)，可將(jiang)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的后(hou)端固定在(zai)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入(ru)機(ji)(ji)上并使芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)回(hui)轉(zhuan)。荒(huang)(huang)管(guan)(guan)(guan)在(zai)前(qian)(qian)臺(tai)的初(chu)始(shi)位(wei)置(zhi)(zhi)和(he)(he)夾緊與全浮(fu)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方式一樣。然而，在(zai)插入(ru)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)時(shi)，不(bu)僅(jin)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)頭(tou)部穿(chuan)過(guo)荒(huang)(huang)管(guan)(guan)(guan)，而且芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)要穿(chuan)過(guo)軋機(ji)(ji)，伸出(chu)軋輥(gun)臺(tai)肩約(yue)3.5m。當芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)到(dao)達(da)此位(wei)置(zhi)(zhi)后(hou)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)始(shi)回(hui)轉(zhuan)，直(zhi)到(dao)荒(huang)(huang)管(guan)(guan)(guan)接觸軋輥(gun)后(hou)一段時(shi)間才停止。當芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推入(ru)機(ji)(ji)到(dao)達(da)行程終點時(shi)，壓管(guan)(guan)(guan)器松開(kai)，荒(huang)(huang)管(guan)(guan)(guan)推入(ru)機(ji)(ji)啟動(dong)前(qian)(qian)進。于是(shi)，荒(huang)(huang)管(guan)(guan)(guan)喂入(ru)軋機(ji)(ji)。軋制(zhi)開(kai)始(shi)后(hou)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)開(kai)始(shi)回(hui)退(tui)。其(qi)回(hui)退(tui)速(su)度(du)(du)與荒(huang)(huang)管(guan)(guan)(guan)的行程長度(du)(du)及前(qian)(qian)進速(su)度(du)(du)有關(guan)，以(yi)便在(zai)軋制(zhi)過(guo)程結束，當毛管(guan)(guan)(guan)離(li)開(kai)軋輥(gun)時(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)正好(hao)從荒(huang)(huang)管(guan)(guan)(guan)中抽出(chu)。見圖6-49。然后(hou)，毛管(guan)(guan)(guan)從軋機(ji)(ji)運走，進行下步加工，而芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)高速(su)返回(hui)其(qi)初(chu)始(shi)位(wei)置(zhi)(zhi)以(yi)備穿(chuan)入(ru)下一根毛管(guan)(guan)(guan)。

3. 限動芯棒

  限(xian)動芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作法(fa)(fa)是全浮芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)和回退(tui)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作法(fa)(fa)的折中方(fang)法(fa)(fa)。采(cai)用這種(zhong)方(fang)法(fa)(fa)時，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)的尾端固定在芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)推(tui)入機(ji)上(shang)(shang)，并可回轉。這和回退(tui)芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)操(cao)作方(fang)式一樣，不同的是，鋼(gang)管(guan)(guan)軋(ya)(ya)(ya)制時芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)向前移(yi)動。在軋(ya)(ya)(ya)制結束時，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)從毛管(guan)(guan)上(shang)(shang)脫出(chu)(chu)。當荒管(guan)(guan)在前臺被夾緊時，穿(chuan)入芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)，直(zhi)到芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)前端伸出(chu)(chu)軋(ya)(ya)(ya)輥(gun)(gun)臺肩(jian)約0.3m左右為止(zhi)。插入芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)時，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)開始(shi)回轉，直(zhi)到荒管(guan)(guan)接(jie)觸(chu)軋(ya)(ya)(ya)輥(gun)(gun)后一段時間才停止(zhi)。芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)到位后，壓管(guan)(guan)器松開，荒管(guan)(guan)推(tui)入機(ji)將荒管(guan)(guan)推(tui)向軋(ya)(ya)(ya)輥(gun)(gun)，直(zhi)到軋(ya)(ya)(ya)制過(guo)程開始(shi)為止(zhi)。軋(ya)(ya)(ya)制過(guo)程中，芯(xin)(xin)(xin)(xin)(xin)捧以低于毛管(guan)(guan)軸向輸(shu)出(chu)(chu)速度(du)的速度(du)和軋(ya)(ya)(ya)件(jian)一起(qi)前進。軋(ya)(ya)(ya)制周(zhou)期結束時，毛管(guan)(guan)從芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)上(shang)(shang)脫出(chu)(chu)，然后，芯(xin)(xin)(xin)(xin)(xin)棒(bang)(bang)(bang)高速返回其(qi)初始(shi)位置。

  三(san)種芯(xin)(xin)棒操(cao)作(zuo)方(fang)(fang)式(shi)(shi)的(de)比(bi)較(jiao)。在(zai)(zai)采用(yong)(yong)回(hui)退(tui)芯(xin)(xin)棒與限動芯(xin)(xin)棒操(cao)作(zuo)方(fang)(fang)式(shi)(shi)的(de)工(gong)廠，只(zhi)有生(sheng)(sheng)產(chan)D/t小于(yu)7.5的(de)鋼(gang)管(guan)(guan)時(shi)才采用(yong)(yong)回(hui)退(tui)芯(xin)(xin)棒操(cao)作(zuo)方(fang)(fang)式(shi)(shi)，而當生(sheng)(sheng)產(chan)D/t大于(yu)7.5的(de)鋼(gang)管(guan)(guan)時(shi)采用(yong)(yong)限動芯(xin)(xin)棒操(cao)作(zuo)方(fang)(fang)式(shi)(shi)。顯然，采用(yong)(yong)回(hui)退(tui)和限動芯(xin)(xin)棒操(cao)作(zuo)方(fang)(fang)式(shi)(shi)時(shi)，軋機產(chan)量比(bi)采用(yong)(yong)全浮芯(xin)(xin)棒時(shi)低，因為，下(xia)一根(gen)荒管(guan)(guan)撥入到前臺之前，在(zai)(zai)用(yong)(yong)的(de)芯(xin)(xin)棒必須返回(hui)其初始位(wei)置(zhi)。同時(shi)，芯(xin)(xin)棒的(de)冷(leng)卻不充分，芯(xin)(xin)棒壽命不長(chang)。