1. 孔型系統
生產寬幅波(bo)紋板應用得最(zui)廣泛(fan)的是連(lian)續成型系統,首先(xian)彎中(zhong)心(xin)波(bo),然后彎相鄰(lin)波(bo),最(zui)后彎邊波(bo)。
單獨一個(ge)波(bo)(bo)彎(wan)(wan)曲(qu)變形(xing)時(shi)常出(chu)現下述情況,即當波(bo)(bo)形(xing)向(xiang)下(開口(kou)朝下)成(cheng)型(xing)(xing)時(shi),波(bo)(bo)形(xing)會延縱(zong)長(chang)方向(xiang)向(xiang)下彎(wan)(wan),而波(bo)(bo)形(xing)向(xiang)上(shang)(開口(kou)向(xiang)上(shang))成(cheng)型(xing)(xing)時(shi),則向(xiang)上(shang)彎(wan)(wan)。之所以(yi)如(ru)此(ci),這是由于波(bo)(bo)形(xing)斷(duan)面(mian)的邊部(bu)在彎(wan)(wan)曲(qu)側面(mian)時(shi)受到(dao)張緊(jin)力(li)的作用時(shi),力(li)圖將整個(ge)斷(duan)面(mian)沿縱(zong)向(xiang)拉長(chang),但此(ci)張緊(jin)力(li)不足以(yi)拉長(chang)整個(ge)剛性斷(duan)面(mian),因此(ci)導致波(bo)(bo)形(xing)前端出(chu)現向(xiang)上(shang)或(huo)向(xiang)下彎(wan)(wan)曲(qu)的現象。
為消除縱向彎曲(qu),將受拉的邊部置于整個斷面中性線上是(shi)必要(yao)的。
2. 鐓壓整形(xing)的專用孔型
采用鐓壓(ya)整形的(de)(de)專(zhuan)用孔(kong)型(xing)(xing),可成(cheng)(cheng)型(xing)(xing)高質量的(de)(de)寬幅型(xing)(xing)鋼。鐓壓(ya)整形的(de)(de)成(cheng)(cheng)型(xing)(xing)方式要求在每道次都會對波紋預彎(wan)曲,且(qie)使(shi)型(xing)(xing)材(cai)(cai)(cai)斷面中(zhong)性(xing)線(xian)與成(cheng)(cheng)品(pin)型(xing)(xing)材(cai)(cai)(cai)中(zhong)性(xing)線(xian)相重(zhong)合。這時型(xing)(xing)材(cai)(cai)(cai)上下所受的(de)(de)力矩(ju)相平(ping)衡,材(cai)(cai)(cai)不會發生(sheng)縱彎(wan)。其(qi)實質就是,在成(cheng)(cheng)型(xing)(xing)的(de)(de)開始(shi)階段就將板(ban)材(cai)(cai)(cai)彎(wan)成(cheng)(cheng)集(ji)中(zhong)間弧形,然后(hou)從垂直(zhi)方向鐓壓(ya)而形成(cheng)(cheng)波紋型(xing)(xing)材(cai)(cai)(cai),這些中(zhong)間弧形波紋在鐓壓(ya)過程(cheng)中(zhong)被壓(ya)縮而產生(sheng)塑(su)性(xing)彎(wan)曲,完成(cheng)(cheng)鐓壓(ya)成(cheng)(cheng)型(xing)(xing)。
對于冷(leng)彎成型(xing)2~4mm的(de)板材,鐓(dui)(dui)壓成型(xing)輥架數一般不超(chao)過(guo)4道(dao)(dao)次,鐓(dui)(dui)壓角逐道(dao)(dao)遞(di)減,前兩道(dao)(dao)鐓(dui)(dui)壓角均為上(shang)道(dao)(dao)鐓(dui)(dui)壓角的(de)0.4~0.6倍。最后道(dao)(dao)次的(de)鐓(dui)(dui)壓角不超(chao)過(guo)1°~2°。
采用鐓壓整形方(fang)式生產波紋(wen)型材,斷(duan)(duan)面(mian)上(shang)各波紋(wen)軸線(xian)間距離(li)應(ying)(ying)等于坯(pi)料(liao)弧(hu)(hu)中心間距離(li),而各弧(hu)(hu)的周(zhou)長應(ying)(ying)與斷(duan)(duan)面(mian)要求相對(dui)應(ying)(ying)。斷(duan)(duan)面(mian)斜直(zhi)線(xian)區(qu)的中間點(dian),應(ying)(ying)是坯(pi)料(liao)弧(hu)(hu)形的接觸(chu)點(dian),并(bing)位(wei)于距波軸同(tong)一距離(li)上(shang)。
考(kao)慮(lv)成型方(fang)法時,以每一(yi)道(dao)次水(shui)平位移不(bu)超(chao)過(guo)6mm 為限制條件(jian),如此要(yao)求(qiu),主要(yao)是為了使(shi)水(shui)平直線段彎曲(qu)變(bian)形(xing)不(bu)產生失穩(wen)現(xian)象。

