冷軋管機根據軋機結構的特點分為：1. 2輥式冷軋管機；2. LD型多輥式冷軋管機；3. 冷連續軋管機；4. 多排輥冷軋管機。目前生產中應用最廣的還是周期式冷軋管機，該機1928年研制，1932年在美國首先使用。它們是獲得高精度薄壁不銹鋼(gang)管(guan)的重要手段，也是外徑或內徑要求高精度的不銹(xiu)鋼厚壁管和特厚壁管，以及異形管、變斷面管等的主要生產方法。兩輥式周期冷軋不銹(xiu)鋼管機的生產規格范圍為：外徑4~250mm,壁厚0.1~40mm,并可生產外徑與壁厚比等于60~100的薄壁管。圖14-3是兩輥式周期冷軋管機的工作過程示意圖。

 兩輥式周期冷軋(ya)(ya)不銹鋼管機的孔(kong)型(xing)(xing)沿(yan)工作(zuo)(zuo)(zuo)弧由(you)大向小變化，入口(kou)比來料外徑(jing)略(lve)大，出口(kou)與成品管直徑(jing)相同(tong)，再后(hou)孔(kong)型(xing)(xing)略(lve)有放大，以便管體在孔(kong)內(nei)轉(zhuan)動(dong)(dong)。軋(ya)(ya)輥隨機架的往復(fu)(fu)運動(dong)(dong)在軋(ya)(ya)件(jian)上左右滾(gun)軋(ya)(ya)。如(ru)(ru)以曲拐(guai)轉(zhuan)角(jiao)(jiao)為橫(heng)坐標，操作(zuo)(zuo)(zuo)過程如(ru)(ru)圖14-3(b)所(suo)示。開始(shi)50°將坯料送(song)進，然后(hou)在120°范圍內(nei)軋(ya)(ya)制，軋(ya)(ya)輥輾至(zhi)右端后(hou)，再用50°間隙軋(ya)(ya)件(jian)轉(zhuan)動(dong)(dong)60°,芯棒也作(zuo)(zuo)(zuo)相應旋(xuan)轉(zhuan)，只是轉(zhuan)角(jiao)(jiao)略(lve)異，以求芯棒能(neng)均勻磨損(sun)。回軋(ya)(ya)軋(ya)(ya)輥向左滾(gun)輾，消(xiao)除(chu)壁厚不均提(ti)高(gao)精度，直至(zhi)左端止。如(ru)(ru)此反復(fu)(fu)。

  圖(tu)14-4為(wei)多輥(gun)式(shi)(shi)周期(qi)冷(leng)軋(ya)(ya)(ya)(ya)(ya)(ya)不銹(xiu)鋼管(guan)機(ji)的(de)(de)(de)(de)(de)工(gong)(gong)作(zuo)示(shi)意圖(tu)。這(zhe)種軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)的(de)(de)(de)(de)(de)操作(zuo)過(guo)程(cheng)(cheng)和兩輥(gun)式(shi)(shi)相同(tong)(tong)，不同(tong)(tong)的(de)(de)(de)(de)(de)是(shi)對軋(ya)(ya)(ya)(ya)(ya)(ya)件(jian)1的(de)(de)(de)(de)(de)加工(gong)(gong)是(shi)由安裝在隔離架2內的(de)(de)(de)(de)(de)3~5個小輥(gun)3進(jin)行的(de)(de)(de)(de)(de)，小輥(gun)沿著固定在機(ji)頭(tou)套簡5上的(de)(de)(de)(de)(de)楔形(xing)(xing)(xing)(xing)滑(hua)軌4往(wang)(wang)返運(yun)動(dong)，依靠滑(hua)軌的(de)(de)(de)(de)(de)摩擦力傳(chuan)動(dong)滾軋(ya)(ya)(ya)(ya)(ya)(ya)管(guan)材。機(ji)頭(tou)套筒(tong)和小輥(gun)隔架間(jian)的(de)(de)(de)(de)(de)運(yun)動(dong)關系(xi)見圖(tu)14-4(b),搖桿在往(wang)(wang)復(fu)擺動(dong)的(de)(de)(de)(de)(de)過(guo)程(cheng)(cheng)中，一般使(shi)(shi)套筒(tong)兩倍于隔離架的(de)(de)(de)(de)(de)速(su)度(du)(du)(du)(du)運(yun)行，楔形(xing)(xing)(xing)(xing)滑(hua)軌的(de)(de)(de)(de)(de)表面(mian)曲線按變(bian)形(xing)(xing)(xing)(xing)要(yao)(yao)求(qiu)設(she)計(ji)。這(zhe)種冷(leng)軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)送進(jin)量(liang)小，一道次(ci)最大橫(heng)截面(mian)收縮率約70左(zuo)右(you)但它的(de)(de)(de)(de)(de)輥(gun)徑(jing)(jing)小，同(tong)(tong)樣(yang)變(bian)形(xing)(xing)(xing)(xing)量(liang)的(de)(de)(de)(de)(de)軋(ya)(ya)(ya)(ya)(ya)(ya)制(zhi)(zhi)壓力小；用(yong)多輥(gun)組成(cheng)孔型(xing)槽淺，軋(ya)(ya)(ya)(ya)(ya)(ya)件(jian)和工(gong)(gong)具(ju)之間(jian)的(de)(de)(de)(de)(de)滑(hua)小，因而這(zhe)種軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)可以生產高(gao)精度(du)(du)(du)(du)的(de)(de)(de)(de)(de)特薄壁(bi)管(guan)。目(mu)前生產的(de)(de)(de)(de)(de)規格范圍為(wei)直徑(jing)(jing)4~120mm,壁(bi)0.03~3.0mm,外徑(jing)(jing)與(yu)壁(bi)厚(hou)比(bi)為(wei)150~250。近年來(lai)冷(leng)軋(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)發展趨勢是(shi)多線、高(gao)速(su)、長(chang)(chang)(chang)行程(cheng)(cheng)，料長(chang)(chang)(chang)度(du)(du)(du)(du)也(ye)(ye)不斷增(zeng)長(chang)(chang)(chang)。“多線”軋(ya)(ya)(ya)(ya)(ya)(ya)制(zhi)(zhi)目(mu)前已應用(yong)很廣，2、3、4、6線冷(leng)軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)均(jun)有(you)投產；“高(gao)速(su)是(shi)指(zhi)不斷提(ti)高(gao)機(ji)頭(tou)單(dan)位時間(jian)內的(de)(de)(de)(de)(de)往(wang)(wang)復(fu)次(ci)數，為(wei)了減(jian)小主傳(chuan)動(dong)系(xi)統承(cheng)受的(de)(de)(de)(de)(de)周期(qi)性變(bian)化的(de)(de)(de)(de)(de)負載度(du)(du)(du)(du)，這(zhe)類軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)皆(jie)設(she)有(you)動(dong)力平衡裝置(zhi)，現在高(gao)速(su)冷(leng)軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)的(de)(de)(de)(de)(de)速(su)度(du)(du)(du)(du)約比(bi)舊式(shi)(shi)軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)提(ti)高(gao)一倍左(zuo)右(you)；“長(chang)(chang)(chang)行程(cheng)(cheng)”是(shi)指(zhi)加大送進(jin)量(liang)，每次(ci)軋(ya)(ya)(ya)(ya)(ya)(ya)制(zhi)(zhi)的(de)(de)(de)(de)(de)延伸長(chang)(chang)(chang)度(du)(du)(du)(du)也(ye)(ye)隨之增(zeng)加，因此要(yao)(yao)求(qiu)軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)的(de)(de)(de)(de)(de)行程(cheng)(cheng)長(chang)(chang)(chang)度(du)(du)(du)(du)與(yu)其相適應，不然就(jiu)不能獲(huo)得光(guang)潔的(de)(de)(de)(de)(de)表面(mian)和尺寸精度(du)(du)(du)(du)。這(zhe)樣(yang)就(jiu)從(cong)工(gong)(gong)具(ju)設(she)計(ji)到軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)結構引起了一系(xi)列(lie)變(bian)化，兩輥(gun)式(shi)(shi)冷(leng)軋(ya)(ya)(ya)(ya)(ya)(ya)機(ji)出現了馬蹄(ti)形(xing)(xing)(xing)(xing)軋(ya)(ya)(ya)(ya)(ya)(ya)槽和環形(xing)(xing)(xing)(xing)軋(ya)(ya)(ya)(ya)(ya)(ya)槽（見圖(tu)14-5),以充(chong)分利用(yong)圓周長(chang)(chang)(chang)度(du)(du)(du)(du)滿(man)足行程(cheng)(cheng)需要(yao)(yao)。應當指(zhi)出，馬蹄(ti)形(xing)(xing)(xing)(xing)和環形(xing)(xing)(xing)(xing)軋(ya)(ya)(ya)(ya)(ya)(ya)槽也(ye)(ye)是(shi)提(ti)高(gao)軋(ya)(ya)(ya)(ya)(ya)(ya)制(zhi)(zhi)速(su)度(du)(du)(du)(du)和多線軋(ya)(ya)(ya)(ya)(ya)(ya)制(zhi)(zhi)的(de)(de)(de)(de)(de)需要(yao)(yao)，因為(wei)同(tong)(tong)一行程(cheng)(cheng)使(shi)(shi)用(yong)這(zhe)種軋(ya)(ya)(ya)(ya)(ya)(ya)槽的(de)(de)(de)(de)(de)輥(gun)徑(jing)(jing)小，降低軋(ya)(ya)(ya)(ya)(ya)(ya)制(zhi)(zhi)壓力，能減(jian)輕(qing)整個機(ji)架結構。

  為增加(jia)(jia)變(bian)形(xing)區(qu)的(de)有效長度，還出現了：1. 附加(jia)(jia)輥架冷軋機(ji)(ji)(ji)(ji)，即(ji)在(zai)主軋機(ji)(ji)(ji)(ji)出口(kou)側裝(zhuang)置(zhi)一(yi)小輥機(ji)(ji)(ji)(ji)架起定(ding)徑作(zuo)用，以(yi)增加(jia)(jia)變(bian)形(xing)區(qu)長度；2. 雙(shuang)對(dui)輥冷軋機(ji)(ji)(ji)(ji)，即(ji)將兩對(dui)軋輥安裝(zhuang)在(zai)同(tong)一(yi)機(ji)(ji)(ji)(ji)架上；3. 多(duo)輥式冷軋機(ji)(ji)(ji)(ji)出現了雙(shuang)排(pai)多(duo)輥式冷軋機(ji)(ji)(ji)(ji)，即(ji)在(zai)同(tong)一(yi)隔離(li)架上前后(hou)各安裝(zhuang)一(yi)組小輥。

  加(jia)長(chang)(chang)不(bu)銹(xiu)鋼管(guan)坯料是提高(gao)軋(ya)機利用(yong)率的(de)重要措施，近年來的(de)冷軋(ya)機最大上(shang)料長(chang)(chang)度一般已達(da)12.5m左(zuo)右，幾(ji)乎增加(jia)了一倍。同時也產(chan)生(sheng)了一個問(wen)題，就是如何(he)改(gai)變上(shang)料和上(shang)芯棒的(de)方法，縮短已經很(hen)長(chang)(chang)了的(de)機身(shen)長(chang)(chang)度。如采用(yong)雙絲杠側裝料結構等。