現代的(de)立式穿(chuan)(chuan)孔(kong)(kong)(kong)機上(shang)一般都配備(bei)完(wan)成以下(xia)動作的(de)輔助機械:(1)在(zai)加熱(re)好(hao)坯料的(de)內(nei)(nei)外表(biao)面上(shang)涂敷玻(bo)璃潤滑劑;(2)將內(nei)(nei)外表(biao)面經潤滑的(de)坯料從(cong)潤滑臺送至穿(chuan)(chuan)孔(kong)(kong)(kong)筒(tong)(tong)上(shang)方的(de)位置;(3)將坯料及剪切環(huan)(huan)送入(ru)穿(chuan)(chuan)孔(kong)(kong)(kong)筒(tong)(tong)并封閉穿(chuan)(chuan)孔(kong)(kong)(kong)筒(tong)(tong)的(de)下(xia)方;(4)將玻(bo)璃潤滑劑施加到(dao)穿(chuan)(chuan)孔(kong)(kong)(kong)筒(tong)(tong)中坯料的(de)上(shang)端面和中心孔(kong)(kong)(kong)內(nei)(nei);(5)冷(leng)卻(que)(que)鐓粗(cu)(cu)桿、鐓粗(cu)(cu)頭;(6)清(qing)理、更換穿(chuan)(chuan)(擴(kuo))孔(kong)(kong)(kong)頭;(7)從(cong)穿(chuan)(chuan)(擴(kuo))孔(kong)(kong)(kong)筒(tong)(tong)中頂出空心坯和剪切環(huan)(huan);(8)冷(leng)卻(que)(que)、清(qing)理、更換剪切環(huan)(huan);(9)冷(leng)卻(que)(que)、清(qing)理穿(chuan)(chuan)(擴(kuo))孔(kong)(kong)(kong)筒(tong)(tong)內(nei)(nei)襯;(10)接(jie)受空心坯料,并將其傳送到(dao)輸出輥道上(shang)。


 以上列舉的(de)機械和(he)裝置(zhi)(zhi)按照(zhao)自動化(hua)程序依次工(gong)作,其結構(gou)和(he)布置(zhi)(zhi)取決(jue)(擴)孔(kong)坯(pi)料的(de)質量(liang)和(he)尺寸(cun)、穿孔(kong)機的(de)結構(gou)形式、穿孔(kong)筒的(de)工(gong)位設置(zhi)(zhi)及其工(gong)位數量(liang)。


德國(guo)制造的10MN(1000t)立式(shi)穿(chuan)孔機(ji)的有關(guan)參數如下(xia):


表 25.jpg

 穿孔余(yu)料應留的(de)高(gao)度由可能得到的(de)穿孔力的(de)大(da)小而定。


 在(zai)穿孔(kong)余料高(gao)度等于(yu)穿孔(kong)頭(tou)(tou)直徑(jing)的(de)一(yi)半(ban)以前(qian),穿孔(kong)過程為等穿孔(kong)力進(jin)行。當確定(ding)了穿孔(kong)機在(zai)使(shi)用最大穿孔(kong)頭(tou)(tou)時(shi)的(de)穿孔(kong)力而不考(kao)慮(lv)其增長,則在(zai)使(shi)用最大穿孔(kong)頭(tou)(tou)時(shi)的(de)穿孔(kong)余料高(gao)度為穿孔(kong)頭(tou)(tou)直徑(jing)之半(ban)。


 實際上,穿孔余料高(gao)度的(de)確(que)定尚(shang)須考慮到穿孔頭邊角半徑的(de)大小,以及其材(cai)料流動錐(zhui)體的(de)影響。


4. 穿孔(kong)余料的剪切力與(yu)支承(cheng)缸的封底(di)推力


  按照剪應(ying)力(li)(li)理論:σ1-σ3 = 2Tmax,則穿孔(kong)余料剪切力(li)(li)為(wei):  Tmax=(σ13)/2      τ=0.5Kf


所采用的Kf相當于無損失鐓壓過程時的數值,但鋼坯下部和穿孔筒底部接觸,約有50~80℃的溫度損失,對于不同的材料在不同溫度下的Kf值見表8-26。


表 26.jpg



 5. 支承缸的(de)封底推力


  穿(chuan)(chuan)(chuan)孔(kong)(kong)(kong)筒的(de)封底荷載(zai),即單位壓力(li),相當(dang)于分布在(zai)底部面(mian)積(ji)(ji)上的(de)穿(chuan)(chuan)(chuan)孔(kong)(kong)(kong)力(li),封底支承(cheng)桿(gan)的(de)直(zhi)徑和穿(chuan)(chuan)(chuan)孔(kong)(kong)(kong)頭(tou)直(zhi)徑相等。封底支承(cheng)桿(gan)的(de)面(mian)積(ji)(ji)(或穿(chuan)(chuan)(chuan)孔(kong)(kong)(kong)頭(tou)的(de)面(mian)積(ji)(ji)),占穿(chuan)(chuan)(chuan)孔(kong)(kong)(kong)筒面(mian)積(ji)(ji)的(de)比值見表8-27.


表 27.jpg


  可見,當穿(chuan)孔(kong)(kong)(kong)余(yu)料的(de)高(gao)度不低于穿(chuan)孔(kong)(kong)(kong)頭直徑之半時,封(feng)底(di)推力能達到(dao)穿(chuan)孔(kong)(kong)(kong)力的(de)50%就足夠了。為了充分利用穿(chuan)孔(kong)(kong)(kong)力,并盡量減小穿(chuan)孔(kong)(kong)(kong)余(yu)料的(de)厚(hou)度,則(ze)作用于封(feng)底(di)支(zhi)承桿上的(de)穿(chuan)孔(kong)(kong)(kong)力的(de)分量要增加,最大可以增加到(dao)等(deng)于穿(chuan)孔(kong)(kong)(kong)力。


 6. 31.5MN(3150t)擠壓車間10MN(1000t)立式穿孔機設備性能(neng):