這種(zhong)軋(ya)機亦(yi)稱皮爾(er)格軋(ya)管機,1891年(nian)由(you)曼(man)乃斯曼(man)兄弟發明,1900年(nian)將芯棒設計(ji)成移動式(shi)為(wei)止才達到完全(quan)機械化,成為(wei)目前(qian)狀(zhuang)態,其(qi)操(cao)作過程如圖4-21所示。

此軋(ya)(ya)機(ji)(ji)操(cao)作的基本特點(dian)(dian)是鍛軋(ya)(ya),軋(ya)(ya)輥旋(xuan)轉方向與軋(ya)(ya)件送(song)進(jin)方向相(xiang)反,軋(ya)(ya)輥孔(kong)型(xing)沿(yan)圓周為(wei)變斷面,軋(ya)(ya)制時(shi)軋(ya)(ya)件反送(song)進(jin)方向運行。送(song)料由做往(wang)復運動的芯棒送(song)進(jin)機(ji)(ji)構完成,這種(zhong)軋(ya)(ya)制形式的延(yan)伸系數為(wei)7~15,可(ke)用(yong)(yong)鋼(gang)錠直(zhi)(zhi)接生產(chan)。目前主要用(yong)(yong)于生產(chan)大直(zhi)(zhi)徑(jing)中、厚(hou)壁(bi)管、異形管,利用(yong)(yong)鍛軋(ya)(ya)的特點(dian)(dian)還可(ke)生產(chan)合金鋼(gang)管。生產(chan)的規(gui)格(ge)范圍外徑(jing)為(wei)114~665mm;壁(bi)厚(hou)2.5~100mm;軋(ya)(ya)后(hou)長度可(ke)達(da)40m.該(gai)軋(ya)(ya)機(ji)(ji)的主要缺(que)點(dian)(dian)是:效率低(di)(di),輔(fu)助操(cao)作時(shi)間占整個周期的25%;孔(kong)型(xing)不易加(jia)工;芯棒長,生產(chan)規(gui)格(ge)范圍窄(zhai),壁(bi)厚(hou)精度低(di)(di)。為(wei)減少周期,軋(ya)(ya)機(ji)(ji)皆采用(yong)(yong)線外插(cha)芯棒鍛頭,再送(song)往(wang)主機(ji)(ji)軋(ya)(ya)制,以減少輔(fu)助操(cao)作時(shi)間。為(wei)改善周期軋(ya)(ya)機(ji)(ji)加(jia)工的規(gui)格(ge)尺(chi)寸窄(zhai)的問題,有的配以張力減徑(jing)來(lai)擴(kuo)大機(ji)(ji)組生產(chan)規(gui)格(ge)范圍。

