目前采(cai)用(yong)的(de)有三種(zhong)芯棒操作方式。早期(qi)的(de)三輥(gun)軋管機均采(cai)用(yong)全浮(fu)芯棒，即使在今天，仍有一(yi)部分機組采(cai)用(yong)全浮(fu)芯棒操作。但是，全浮(fu)芯棒操作方式有如下缺點：

（1）軋制(zhi)特厚壁管時不易脫棒；

（2）對各(ge)種尺寸的毛(mao)管均需要配置(zhi)再(zai)加熱(re)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(xia)是(shi)三種(zhong)不同芯棒操作(zuo)方式的(de)簡述。

1. 全浮芯棒(bang)

  采(cai)用(yong)全(quan)浮芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作方(fang)式(shi)(shi)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)被撥入(ru)(ru)到(dao)(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)入(ru)(ru)機前(qian)(qian)的(de)人口臺，落(luo)到(dao)(dao)和軋(ya)(ya)(ya)(ya)(ya)機中心(xin)線一(yi)(yi)(yi)致的(de)U形槽里。氣(qi)動(dong)壓(ya)管(guan)(guan)(guan)器(qi)壓(ya)在(zai)(zai)荒(huang)(huang)(huang)管(guan)(guan)(guan)上(shang)，將其夾緊，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)(ru)機將芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)穿入(ru)(ru)荒(huang)(huang)(huang)管(guan)(guan)(guan)內(nei)。一(yi)(yi)(yi)旦芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)完全(quan)穿入(ru)(ru)，壓(ya)管(guan)(guan)(guan)器(qi)就松開(kai)(kai)，于是(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)連同芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)(yi)(yi)并(bing)(bing)向軋(ya)(ya)(ya)(ya)(ya)輥方(fang)向送(song)去。如果荒(huang)(huang)(huang)管(guan)(guan)(guan)不易(yi)喂入(ru)(ru)軋(ya)(ya)(ya)(ya)(ya)機，就用(yong)荒(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)入(ru)(ru)機在(zai)(zai)后面(mian)推(tui)下(xia)，以幫助荒(huang)(huang)(huang)管(guan)(guan)(guan)喂入(ru)(ru)。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)開(kai)(kai)始(shi)軋(ya)(ya)(ya)(ya)(ya)制時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)入(ru)(ru)機和芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推(tui)入(ru)(ru)機便(bian)返回(hui)到(dao)(dao)初始(shi)位(wei)置。但是(shi)，當(dang)采(cai)用(yong)小直(zhi)徑芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)軋(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)時(shi)，荒(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)入(ru)(ru)機可保留在(zai)(zai)前(qian)(qian)位(wei)，充當(dang)導衛，防(fang)止芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)抖(dou)動(dong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)延伸(shen)后，荒(huang)(huang)(huang)管(guan)(guan)(guan)和芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一(yi)(yi)(yi)起通過軋(ya)(ya)(ya)(ya)(ya)機向前(qian)(qian)移動(dong)軋(ya)(ya)(ya)(ya)(ya)制終了時(shi)，后臺輥子升起，將毛管(guan)(guan)(guan)及芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)送(song)到(dao)(dao)輸(shu)出輥道。然(ran)后，從輸(shu)出輥送(song)到(dao)(dao)脫棒(bang)(bang)(bang)(bang)(bang)機，將芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)從毛管(guan)(guan)(guan)中脫出。脫棒(bang)(bang)(bang)(bang)(bang)后，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)先(xian)冷卻(que)，再送(song)到(dao)(dao)軋(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)機前(qian)(qian)臺，以備再用(yong)。荒(huang)(huang)(huang)管(guan)(guan)(guan)則由輥道送(song)走(zou)，進行下(xia)一(yi)(yi)(yi)步加工。采(cai)用(yong)全(quan)浮棒(bang)(bang)(bang)(bang)(bang)操作方(fang)式(shi)(shi)時(shi)，軋(ya)(ya)(ya)(ya)(ya)機生(sheng)產率最高，因此，下(xia)一(yi)(yi)(yi)根(gen)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)前(qian)(qian)端(duan)實際上(shang)可以跟(gen)在(zai)(zai)正(zheng)在(zai)(zai)軋(ya)(ya)(ya)(ya)(ya)制的(de)前(qian)(qian)一(yi)(yi)(yi)根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)的(de)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的(de)后面(mian)。這(zhe)是(shi)可能的(de)，因為在(zai)(zai)前(qian)(qian)一(yi)(yi)(yi)根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)軋(ya)(ya)(ya)(ya)(ya)完以前(qian)(qian)，后一(yi)(yi)(yi)根(gen)荒(huang)(huang)(huang)管(guan)(guan)(guan)可以放(fang)在(zai)(zai)前(qian)(qian)臺上(shang)、并(bing)(bing)穿好芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)。

2. 回(hui)退(tui)芯棒

  回退芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)方(fang)式和浮動(dong)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)一樣使(shi)用同一荒(huang)管(guan)(guan)(guan)推人(ren)機(ji)(ji)(ji)與(yu)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)，但是芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)上(shang)加(jia)了(le)一套裝置(zhi)(zhi)，可將芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)的后(hou)(hou)端固定在(zai)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)上(shang)并使(shi)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)回轉。荒(huang)管(guan)(guan)(guan)在(zai)前(qian)臺的初始(shi)位(wei)置(zhi)(zhi)和夾緊與(yu)全浮芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)操作(zuo)方(fang)式一樣。然(ran)而，在(zai)插入芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)時(shi)，不(bu)僅(jin)芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)頭部穿過荒(huang)管(guan)(guan)(guan)，而且芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)要(yao)穿過軋(ya)機(ji)(ji)(ji)，伸出軋(ya)輥臺肩約3.5m。當芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)到(dao)達此(ci)位(wei)置(zhi)(zhi)后(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開(kai)(kai)(kai)(kai)始(shi)回轉，直到(dao)荒(huang)管(guan)(guan)(guan)接觸軋(ya)輥后(hou)(hou)一段時(shi)間才(cai)停(ting)止。當芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)推入機(ji)(ji)(ji)到(dao)達行(xing)程(cheng)(cheng)終點(dian)時(shi)，壓管(guan)(guan)(guan)器松開(kai)(kai)(kai)(kai)，荒(huang)管(guan)(guan)(guan)推入機(ji)(ji)(ji)啟動(dong)前(qian)進(jin)。于(yu)是，荒(huang)管(guan)(guan)(guan)喂(wei)入軋(ya)機(ji)(ji)(ji)。軋(ya)制開(kai)(kai)(kai)(kai)始(shi)后(hou)(hou)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)開(kai)(kai)(kai)(kai)始(shi)回退。其(qi)回退速(su)度(du)與(yu)荒(huang)管(guan)(guan)(guan)的行(xing)程(cheng)(cheng)長度(du)及前(qian)進(jin)速(su)度(du)有關(guan)，以便(bian)在(zai)軋(ya)制過程(cheng)(cheng)結束，當毛管(guan)(guan)(guan)離開(kai)(kai)(kai)(kai)軋(ya)輥時(shi)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)正好(hao)從(cong)荒(huang)管(guan)(guan)(guan)中抽出。見(jian)圖6-49。然(ran)后(hou)(hou)，毛管(guan)(guan)(guan)從(cong)軋(ya)機(ji)(ji)(ji)運走，進(jin)行(xing)下步加(jia)工，而芯(xin)(xin)棒(bang)(bang)(bang)(bang)(bang)高速(su)返回其(qi)初始(shi)位(wei)置(zhi)(zhi)以備穿入下一根(gen)毛管(guan)(guan)(guan)。

3. 限動芯棒

  限動(dong)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)法是(shi)全浮芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)和(he)(he)回(hui)(hui)退(tui)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)法的折中方法。采(cai)用這種方法時(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)的尾端(duan)固定(ding)在(zai)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)推(tui)入機上，并可回(hui)(hui)轉。這和(he)(he)回(hui)(hui)退(tui)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)操作(zuo)方式一樣，不同(tong)的是(shi)，鋼(gang)管(guan)(guan)(guan)軋(ya)(ya)制時(shi)(shi)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)向(xiang)(xiang)(xiang)前(qian)(qian)移動(dong)。在(zai)軋(ya)(ya)制結束時(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)從毛管(guan)(guan)(guan)上脫出(chu)。當(dang)荒(huang)(huang)(huang)管(guan)(guan)(guan)在(zai)前(qian)(qian)臺被(bei)夾緊(jin)時(shi)(shi)，穿(chuan)入芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)，直到(dao)芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)前(qian)(qian)端(duan)伸出(chu)軋(ya)(ya)輥臺肩(jian)約0.3m左右為止。插(cha)入芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)時(shi)(shi)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)開始(shi)回(hui)(hui)轉，直到(dao)荒(huang)(huang)(huang)管(guan)(guan)(guan)接觸軋(ya)(ya)輥后(hou)(hou)一段時(shi)(shi)間才停止。芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)到(dao)位(wei)(wei)后(hou)(hou)，壓管(guan)(guan)(guan)器(qi)松開，荒(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)入機將荒(huang)(huang)(huang)管(guan)(guan)(guan)推(tui)向(xiang)(xiang)(xiang)軋(ya)(ya)輥，直到(dao)軋(ya)(ya)制過程開始(shi)為止。軋(ya)(ya)制過程中，芯(xin)(xin)(xin)捧以低(di)于毛管(guan)(guan)(guan)軸(zhou)向(xiang)(xiang)(xiang)輸出(chu)速度的速度和(he)(he)軋(ya)(ya)件一起前(qian)(qian)進。軋(ya)(ya)制周期結束時(shi)(shi)，毛管(guan)(guan)(guan)從芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)上脫出(chu)，然后(hou)(hou)，芯(xin)(xin)(xin)棒(bang)(bang)(bang)(bang)高速返(fan)回(hui)(hui)其初始(shi)位(wei)(wei)置。

  三種芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方(fang)式(shi)的(de)(de)比較。在采用(yong)(yong)回退芯(xin)(xin)棒(bang)(bang)(bang)(bang)與(yu)限動(dong)(dong)芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方(fang)式(shi)的(de)(de)工廠，只(zhi)有生產D/t小于7.5的(de)(de)鋼管(guan)時(shi)(shi)才采用(yong)(yong)回退芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方(fang)式(shi)，而當生產D/t大(da)于7.5的(de)(de)鋼管(guan)時(shi)(shi)采用(yong)(yong)限動(dong)(dong)芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方(fang)式(shi)。顯然，采用(yong)(yong)回退和(he)限動(dong)(dong)芯(xin)(xin)棒(bang)(bang)(bang)(bang)操(cao)(cao)作(zuo)方(fang)式(shi)時(shi)(shi)，軋機產量比采用(yong)(yong)全浮(fu)芯(xin)(xin)棒(bang)(bang)(bang)(bang)時(shi)(shi)低，因為，下一根荒管(guan)撥入(ru)到(dao)前臺之前，在用(yong)(yong)的(de)(de)芯(xin)(xin)棒(bang)(bang)(bang)(bang)必須返(fan)回其初始(shi)位置(zhi)。同時(shi)(shi)，芯(xin)(xin)棒(bang)(bang)(bang)(bang)的(de)(de)冷卻(que)不充分，芯(xin)(xin)棒(bang)(bang)(bang)(bang)壽(shou)命不長。