現(xian)代的(de)立式穿孔機上(shang)一般都配備完成以下(xia)動作的(de)輔助機械:(1)在加(jia)熱好坯(pi)料(liao)(liao)(liao)的(de)內外(wai)表面(mian)上(shang)涂敷玻璃潤滑劑(ji);(2)將內外(wai)表面(mian)經潤滑的(de)坯(pi)料(liao)(liao)(liao)從(cong)潤滑臺送至(zhi)穿孔筒(tong)(tong)上(shang)方的(de)位置;(3)將坯(pi)料(liao)(liao)(liao)及剪(jian)切環送入穿孔筒(tong)(tong)并封(feng)閉(bi)穿孔筒(tong)(tong)的(de)下(xia)方;(4)將玻璃潤滑劑(ji)施加(jia)到穿孔筒(tong)(tong)中(zhong)(zhong)坯(pi)料(liao)(liao)(liao)的(de)上(shang)端面(mian)和中(zhong)(zhong)心(xin)孔內;(5)冷卻鐓(dui)粗(cu)桿、鐓(dui)粗(cu)頭;(6)清(qing)理(li)、更(geng)換(huan)(huan)穿(擴)孔頭;(7)從(cong)穿(擴)孔筒(tong)(tong)中(zhong)(zhong)頂出(chu)空(kong)心(xin)坯(pi)和剪(jian)切環;(8)冷卻、清(qing)理(li)、更(geng)換(huan)(huan)剪(jian)切環;(9)冷卻、清(qing)理(li)穿(擴)孔筒(tong)(tong)內襯;(10)接受空(kong)心(xin)坯(pi)料(liao)(liao)(liao),并將其傳送到輸出(chu)輥道上(shang)。
以上(shang)列舉的機械和(he)裝置(zhi)(zhi)按照自(zi)動化(hua)程(cheng)序依(yi)次工作,其(qi)結(jie)構(gou)和(he)布置(zhi)(zhi)取決(擴)孔坯料的質量(liang)和(he)尺寸、穿孔機的結(jie)構(gou)形式、穿孔筒的工位(wei)設置(zhi)(zhi)及其(qi)工位(wei)數量(liang)。
德國制造的10MN(1000t)立(li)式穿孔(kong)機的有關參(can)數如下:
穿孔余料應留的高度由可能得到的穿孔力的大小(xiao)而定。
在穿(chuan)(chuan)孔(kong)(kong)(kong)余料高(gao)度等于穿(chuan)(chuan)孔(kong)(kong)(kong)頭直徑的(de)一(yi)半以前(qian),穿(chuan)(chuan)孔(kong)(kong)(kong)過程(cheng)為等穿(chuan)(chuan)孔(kong)(kong)(kong)力進行。當確(que)定了穿(chuan)(chuan)孔(kong)(kong)(kong)機(ji)在使用(yong)最大(da)穿(chuan)(chuan)孔(kong)(kong)(kong)頭時的(de)穿(chuan)(chuan)孔(kong)(kong)(kong)力而(er)不考(kao)慮(lv)其增長(chang),則在使用(yong)最大(da)穿(chuan)(chuan)孔(kong)(kong)(kong)頭時的(de)穿(chuan)(chuan)孔(kong)(kong)(kong)余料高(gao)度為穿(chuan)(chuan)孔(kong)(kong)(kong)頭直徑之半。
實際上,穿孔(kong)余料高度的確定(ding)尚(shang)須(xu)考慮到穿孔(kong)頭邊角半徑(jing)的大(da)小,以及其材料流動錐體的影響。
4. 穿(chuan)孔余料(liao)的(de)剪切力與支承缸的(de)封底(di)推力
按(an)照(zhao)剪應(ying)力理論:σ1-σ3 = 2Tmax,則穿孔余料剪切力為: Tmax=(σ1-σ3)/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。
5. 支承缸的封底推力
穿(chuan)(chuan)孔(kong)筒的(de)(de)(de)封(feng)底荷載,即單位壓力,相當于分布在底部面(mian)(mian)積上的(de)(de)(de)穿(chuan)(chuan)孔(kong)力,封(feng)底支承(cheng)桿的(de)(de)(de)直徑和(he)穿(chuan)(chuan)孔(kong)頭直徑相等。封(feng)底支承(cheng)桿的(de)(de)(de)面(mian)(mian)積(或(huo)穿(chuan)(chuan)孔(kong)頭的(de)(de)(de)面(mian)(mian)積),占穿(chuan)(chuan)孔(kong)筒面(mian)(mian)積的(de)(de)(de)比值(zhi)見表8-27.
可見,當穿(chuan)(chuan)(chuan)孔(kong)余料的(de)高(gao)度不(bu)低于(yu)穿(chuan)(chuan)(chuan)孔(kong)頭直徑之半時,封(feng)底推(tui)力能(neng)達到穿(chuan)(chuan)(chuan)孔(kong)力的(de)50%就足夠了(le)(le)。為了(le)(le)充(chong)分利用穿(chuan)(chuan)(chuan)孔(kong)力,并盡(jin)量減(jian)小穿(chuan)(chuan)(chuan)孔(kong)余料的(de)厚度,則作用于(yu)封(feng)底支承桿上(shang)的(de)穿(chuan)(chuan)(chuan)孔(kong)力的(de)分量要增(zeng)加,最(zui)大(da)可以(yi)增(zeng)加到等(deng)于(yu)穿(chuan)(chuan)(chuan)孔(kong)力。
6. 31.5MN(3150t)擠壓車(che)間10MN(1000t)立式穿孔機設備性能: