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雙曲鋁蒙皮拉伸是鋁板<\/span><\/span>兩端在<\/span><\/span>拉伸<\/span><\/span>機<\/span><\/span>的拉伸帶<\/span><\/span>夾緊下，被工作臺<\/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，產生不均勻的平面拉應變而使板料與<\/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，而提高成形準確度。但在拉形情況下，材料的變形狀態(tài)卻要復雜得多。<\/span><\/span><\/span><\/p>

拉伸<\/span><\/span>過程大致可分為三個階段<\/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，<\/span><\/span>直到最邊緣的條帶也與<\/span><\/span>木模<\/span><\/span>貼合為止，<\/span><\/span>于是這時毛料的內表面都<\/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）所受的拉應力超過屈服點，<\/span><\/span>以達到減少回彈，<\/span><\/span>提高成形準確度的目的。<\/span><\/span><\/span><\/p>

 <\/span>現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，加工設備結構復雜，工藝繁瑣，成本較高。<\/span><\/span>
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作為建筑外墻裝飾的一種主要選擇對象，雙曲鋁單板系列產品多用于樓宇大堂、機場、車站、重要公共設施、體育場館、民族特色建筑等**建筑。<\/span><\/span><\/span><\/p>