輥式冷彎成型是以金屬薄板或帶卷為原料,并通過多架裝配了具有一定形狀的成型輥對坯料逐架次進行彎曲變形,從而得到均一最面的產品的塑性加工方法。


  一般每(mei)架成(cheng)型(xing)機裝有一對(dui)或多對(dui)成(cheng)型(xing)輥(gun),每(mei)列成(cheng)型(xing)機組由兩(liang)架以上的(de)成(cheng)型(xing)機組線。在(zai)輥(gun)式(shi)冷彎成(cheng)型(xing)過(guo)程中只有彎曲(qu)(qu)變(bian)(bian)形。除坯料(liao)彎曲(qu)(qu)角局部有輕微(wei)減薄外(wai),變(bian)(bian)形材料(liao)的(de)厚度在(zai)成(cheng)型(xing)過(guo)程中保持不變(bian)(bian)。這種加(jia)(jia)工(gong)方法特別適合于(yu)外(wai)形縱(zong)長、批量較大的(de)高(gao)精度產品的(de)加(jia)(jia)工(gong),此外(wai),在(zai)輥(gun)式(shi)冷彎成(cheng)型(xing)過(guo)程中,可以很容易地將沖裁(cai)、打(da)孔、壓印、縱(zong)彎等輔(fu)助加(jia)(jia)工(gong)引入進來(lai)。


  輥式冷彎成(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝可分為四種,即單張(或單件)成(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝、成(cheng)(cheng)(cheng)卷成(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝、連續(xu)成(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝和聯合(he)加工(gong)(gong)工(gong)(gong)藝。每一種工(gong)(gong)藝都可分為3個階段(duan),即成(cheng)(cheng)(cheng)型(xing)(xing)前坯料準備階段(duan)、成(cheng)(cheng)(cheng)型(xing)(xing)加工(gong)(gong)階段(duan)、型(xing)(xing)材精整(zheng)階段(duan)。


  單張(zhang)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)工(gong)(gong)藝(yi)就是預(yu)定(ding)尺(chi)坯料(liao)(liao)的(de)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)方(fang)法。這(zhe)種(zhong)(zhong)方(fang)法在坯料(liao)(liao)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)之前將坯料(liao)(liao)切(qie)成(cheng)(cheng)(cheng)(cheng)定(ding)尺(chi)長度,然(ran)后(hou)用(yong)(yong)(yong)送(song)料(liao)(liao)輥將坯料(liao)(liao)送(song)進成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)輥,成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)后(hou)的(de)型(xing)(xing)(xing)材不必(bi)經剪切(qie)即可收(shou)集(ji)入庫。采(cai)用(yong)(yong)(yong)這(zhe)種(zhong)(zhong)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)工(gong)(gong)藝(yi)的(de)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)輥的(de)速度一般在15~75m/min.這(zhe)種(zhong)(zhong)工(gong)(gong)藝(yi)主要(yao)應(ying)用(yong)(yong)(yong)于小批量、成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)后(hou)型(xing)(xing)(xing)材鋸切(qie)比較(jiao)困難的(de)情況下。采(cai)用(yong)(yong)(yong)單張(zhang)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)工(gong)(gong)藝(yi)成(cheng)(cheng)(cheng)(cheng)型(xing)(xing)(xing)機組的(de)設(she)備較(jiao)簡單、工(gong)(gong)具(ju)費用(yong)(yong)(yong)少、投資(zi)低。但用(yong)(yong)(yong)這(zhe)種(zhong)(zhong)生產工(gong)(gong)藝(yi)得到(dao)的(de)型(xing)(xing)(xing)材邊部縱向拉伸較(jiao)大,因(yin)而只有利用(yong)(yong)(yong)側(ce)立輥才能得到(dao)比較(jiao)精確的(de)產品形(xing)。


  成(cheng)(cheng)(cheng)(cheng)(cheng)卷(juan)(juan)成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝(yi)(yi)(yi)和連續成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝(yi)(yi)(yi)基本相同,所不(bu)同的(de)是(shi)連續成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)時前一卷(juan)(juan)帶材的(de)尾部與后(hou)一卷(juan)(juan)帶材的(de)頭(tou)(tou)部經過齊對(dui)焊,使坯料帶材連續不(bu)斷地進(jin)(jin)人成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)機進(jin)(jin)行(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)。而成(cheng)(cheng)(cheng)(cheng)(cheng)卷(juan)(juan)成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)時帶卷(juan)(juan)頭(tou)(tou)尾不(bu)對(dui)焊,進(jin)(jin)行(xing)單卷(juan)(juan)供料成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)。與單張成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝(yi)(yi)(yi)相比(bi),這兩種成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝(yi)(yi)(yi)更加高(gao)效、高(gao)產、通用。這兩種成(cheng)(cheng)(cheng)(cheng)(cheng)型(xing)(xing)工(gong)(gong)藝(yi)(yi)(yi)的(de)主要優點是(shi):


①. 帶卷成本低、切損(sun)少,因而(er)降(jiang)低了材料總成本。


②. 由于(yu)需(xu)要的成型機架數少且(qie)不(bu)需(xu)要額外(wai)的導衛裝置,因而工具成本低。


③. 可以加工形狀比單張成型(xing)工藝更復雜的(de)型(xing)材(cai)。


④. 型材的頭尾部扭(niu)曲及張開度減(jian)小。


⑤. 由(you)于操作(zuo)幾乎是連續的,因而生產率得到(dao)提高。


  但這(zhe)(zhe)兩(liang)種(zhong)成(cheng)型工藝(yi)(yi)需要開卷機、活套器、對焊機、定尺飛鋸或飛剪(jian)等輔助設備,因而其(qi)機組設備投資較(jiao)大(da)、占(zhan)地較(jiao)大(da)。成(cheng)型機組的成(cheng)型速度一般為(wei)30~90m/min.目前(qian)投產的絕大(da)多數輥(gun)式(shi)冷彎(wan)成(cheng)型機組均是采用這(zhe)(zhe)兩(liang)種(zhong)工藝(yi)(yi),因此后面將(jiang)以這(zhe)(zhe)兩(liang)種(zhong)成(cheng)型工藝(yi)(yi)為(wei)例進行重點闡述,圖5-1給出了其(qi)工藝(yi)(yi)流程示意圖。


圖 1.jpg


  聯合加(jia)工(gong)工(gong)藝(yi)用(yong)于加(jia)工(gong)具有特定要求的冷(leng)彎(wan)(wan)(wan)型(xing)(xing)(xing)鋼(gang)(gang),如(ru)高強度冷(leng)彎(wan)(wan)(wan)型(xing)(xing)(xing)鋼(gang)(gang)、閉口(kou)焊(han)接冷(leng)彎(wan)(wan)(wan)型(xing)(xing)(xing)鋼(gang)(gang)、熱處(chu)理(li)強化(hua)冷(leng)彎(wan)(wan)(wan)型(xing)(xing)(xing)鋼(gang)(gang)、周期波紋板沖孔冷(leng)彎(wan)(wan)(wan)型(xing)(xing)(xing)鋼(gang)(gang),涂層(ceng)冷(leng)彎(wan)(wan)(wan)型(xing)(xing)(xing)鋼(gang)(gang)等。聯合加(jia)工(gong)成型(xing)(xing)(xing)機(ji)組的設備最復雜(za)、投資最高。根據產(chan)品的要求這種機(ji)組可包括如(ru)下設備:直縫焊(han)機(ji)、對焊(han)機(ji)、輥(gun)式沖孔機(ji)、輥(gun)式壓(ya)印機(ji)、涂層(ceng)機(ji)、熱處(chu)理(li)設備等。


圖 2.jpg


 輥(gun)式(shi)冷(leng)彎(wan)成(cheng)(cheng)(cheng)型(xing)是用一組(zu)成(cheng)(cheng)(cheng)型(xing)輥(gun)將(jiang)帶(dai)材(cai)逐漸壓(ya)彎(wan)成(cheng)(cheng)(cheng)所需的(de)(de)(de)斷面型(xing)材(cai),現以冷(leng)彎(wan)角鋼為例,圖5-2是由4個(ge)機架組(zu)成(cheng)(cheng)(cheng)的(de)(de)(de)輥(gun)式(shi)冷(leng)彎(wan)成(cheng)(cheng)(cheng)型(xing)機組(zu),第一機架完成(cheng)(cheng)(cheng)帶(dai)材(cai)的(de)(de)(de)平整和送進工作,第二(er)~第四機架各承擔一定的(de)(de)(de)壓(ya)彎(wan)成(cheng)(cheng)(cheng)型(xing)任務,使帶(dai)材(cai)通過后被彎(wan)曲壓(ya)制成(cheng)(cheng)(cheng)角型(xing)材(cai)。每一對(dui)成(cheng)(cheng)(cheng)型(xing)輥(gun)所分擔的(de)(de)(de)彎(wan)曲變(bian)形量,決定了該機架孔(kong)型(xing)設計的(de)(de)(de)基本尺寸。不過至(zhi)今的(de)(de)(de)孔(kong)型(xing)設計主要還是依靠經驗的(de)(de)(de)積累(lei),尚(shang)缺(que)乏理論解析方法。