雙曲鋁蒙皮拉伸是鋁板<\/span><\/span>兩端在<\/span><\/span>拉伸<\/span><\/span>機(jī)<\/span><\/span>的拉伸帶<\/span><\/span>夾緊下,被工作臺(tái)<\/span><\/span>上面的<\/span><\/span>的<\/span><\/span>拉伸木<\/span><\/span>模和<\/span><\/span>鋁板<\/span><\/span>接觸,產(chǎn)生不均勻的平面拉應(yīng)變而使板料與<\/span><\/span>拉伸<\/span><\/span>模貼合的成形方法。<\/span><\/span><\/span><\/p> 1)<\/span><\/span>縱向拉形<\/span><\/span><\/span><\/p> 鋁板<\/span><\/span>沿縱向兩端頭夾緊,在被工作臺(tái)頂升<\/span><\/span>的<\/span><\/span>拉伸模<\/span><\/span>模頂力和拉伸夾縱向拉力雙重作用<\/span><\/span>下,使<\/span><\/span>鋁板<\/span><\/span>與<\/span><\/span>拉伸<\/span><\/span>模貼合的成形方法。<\/span><\/span>一般用于縱向曲度大的狹長形蒙皮零件<\/span><\/span>成形。<\/span><\/span>縱向<\/span><\/span>拉伸<\/span><\/span>機(jī)加上上壓裝置,可成形蒙皮<\/span><\/span>上有凹陷和鼓包的部分。<\/span><\/span><\/span><\/p> 2)<\/span><\/span>橫向拉形<\/span><\/span><\/span><\/p> 鋁板<\/span><\/span>沿橫向兩端頭夾緊,在被工作臺(tái)頂升<\/span><\/span>的<\/span><\/span>拉伸<\/span><\/span>模頂力作用下,使<\/span><\/span>鋁板<\/span><\/span>與<\/span><\/span>拉伸<\/span><\/span>模貼合<\/span><\/span>的成形方法。<\/span><\/span>一般用于橫向曲度大的狹長形蒙皮零件<\/span><\/span>。<\/span><\/span><\/span><\/p> 蒙皮零件拉形與型材零件拉彎相似,都是以增加拉力減少回彈,而提高成形準(zhǔn)確度。但在拉形情況下,材料的變形狀態(tài)卻要復(fù)雜得多。<\/span><\/span><\/span><\/p> 拉伸<\/span><\/span>過程大致可分為三個(gè)階段<\/span><\/span>:<\/span><\/span><\/p> a)<\/span><\/span>開始階段<\/span><\/span><\/b><\/span><\/b><\/p> 將<\/span><\/span>拉伸木模放在拉伸機(jī)上<\/span><\/span>,并將<\/span><\/span>鋁板<\/span><\/span>毛料兩端夾入<\/span><\/span>拉伸帶下面<\/span><\/span>,然后<\/span><\/span>拉緊拉伸帶<\/span><\/span>,<\/span><\/span>木模<\/span><\/span>脊背**處與毛料接觸,毛料被彎曲并張緊。<\/span><\/span><\/span><\/p> b)中間階段<\/span><\/b><\/span><\/b><\/p> 設(shè)想將毛料沿<\/span><\/span>木模<\/span><\/span>橫切面劃分為<\/span><\/span>許多條帶,隨著<\/span><\/span>拉伸帶拉緊<\/span><\/span>,<\/span><\/span>中間條帶的附近條帶相繼與<\/span><\/span>木模<\/span><\/span>脊背貼合,<\/span><\/span>循此漸進(jìn),<\/span><\/span>直到最邊緣的條帶也與<\/span><\/span>木模<\/span><\/span>貼合為止,<\/span><\/span>于是這時(shí)毛料的內(nèi)表面都<\/span><\/span>與<\/span><\/span>木模<\/span><\/span>貼合,取得了<\/span><\/span>木模<\/span><\/span>表面的形狀。<\/span><\/span><\/span><\/p> c)終了階段<\/span><\/b><\/span><\/b><\/p> 毛料與<\/span><\/span>木模<\/span><\/span>表面完全貼合后,<\/span><\/span>再作少量補(bǔ)充拉伸<\/span><\/span>.<\/span>例如約<\/span><\/span>1%的延<\/span>伸率,<\/span><\/span>使邊緣材料<\/span><\/span>(<\/span>即<\/span><\/span>**與<\/span><\/span>木模<\/span><\/span>接觸條帶)所受的拉應(yīng)力超過屈服點(diǎn),<\/span><\/span>以達(dá)到減少回彈,<\/span><\/span>提高成形準(zhǔn)確度的目的。<\/span><\/span><\/span><\/p> <\/span>現(xiàn)代建筑幕墻裝飾面板有很多地方需要用雙曲面板,如球體狀裝飾面板、圓環(huán)面板等,廣泛用于體育場館、展覽管和火車站等地方。這些雙曲面板一般采取模壓或蒙皮拉伸的方法進(jìn)行加工,或采用拉彎的方法加工成型,但這些加工方法的通用性和普適性差,加工設(shè)備結(jié)構(gòu)復(fù)雜,工藝繁瑣,成本較高。<\/span><\/span> <\/span><\/span><\/p> 作為建筑外墻裝飾的一種主要選擇對(duì)象,雙曲鋁單板系列產(chǎn)品多用于樓宇大堂、機(jī)場、車站、重要公共設(shè)施、體育場館、民族特色建筑等**建筑。<\/span><\/span><\/span><\/p>
|