200922711 . 九、發明說明： 【發明所屬之技術領域】 ， 本發明係關於一種金屬殼體 於-種應用於電子装置之金屬殼體;=二尤其係關 【先前技術】 /、μ方法。 近年來，金屬殼體由於其具有 感佳等特點，被廣泛岸用於 又円、硬度好、質 俽廣之應用於仃動電話 請參閱圖1，一種用於帝孚姑$电卞衣置中。 包括一近似矩形之底 側壁12、第：㈣13、$ 貝^伸之第 -側壁12、第二側壁13、第三:壁 呤洁姑 *命产时 土 14及第四側壁15順 -人連接亚與底壁11共同形成—夏有— 體用以容置電子元件(圖未示)。'有開口之腔體。腔 第一側壁12、第二側壁n、 辟15盥麻辟n ^ 弟二側壁14及第四侧 :一之連接處—般設計為H角結構，如此便於 :屬，H)採用金屬板材直接拉深成型之方式製：便： 降低製造成本與製造難度。 體之第T子裝置外觀之需要’有時需要將金屬殼 Γ側壁13、第三側壁14及第四側 處設計為非81角之連接結構，例如 二角、-。構。由於拉深成型技術本身之限制，尖角结構等 結構較難採用金屬板材直接拉深成‘之方 =備、。此外，上述金屬殼體10之第一側壁12、第二側 13、第二側壁14與第四側壁15之厚度等於底壁η之 200922711 厚度相等，如此會造成第一側壁12、第二側壁13、第二 側壁14與第四側壁14之強度較弱。由於行動電話等^ 子裝置之金屬殼體需要輕薄短小，故通常採用金屬薄材 製造，若為增強側壁之強度，而使金屬殼體1〇之第—側 土 12第一側壁13、第三側壁14與第四側壁之厚产 大於底壁11之厚度，則此時之金屬殼體同樣難以藉由直 接拉深成型之方式製備，在習知技術中可採用壓鑄成型 之方法形成該類金屬殼體。然，藉由壓鎢成型之方法形 成，金屬殼體其外觀品質較差’需要經過拋光方能滿足 外觀要求’如此生產速度慢’成本較高。此外，還可採 用數控機床加卫形成該類金屬殼體，即將較厚之板材銑 削加工成側壁厚度底壁厚度大之金屬殼體，由於整殼體 都需要銑削加工’其耗費之時間相當長，故生產效率低， .成本很高，不適合大批量生產。 圖2所不為採用i述方法加工得到之金屬μ體之側壁 處^金屬材質（以常用之AL5052銘合金為例），在23±5〇c ^飢度條件下、40〜80%RH之濕度條件下，放大200倍之 至^圖，該材質之内部金相組織較為鬆散。另，在23±5。(： 2:度條件下、40〜8〇%RH之濕度條件下及0.5千克之試 " 下’其維氏硬度值為68〜70。 【發明内容】 折曰；X上内谷，有必要提供—種具有較佳外觀品 貝、成本較低之金屬殼體。 另，還有必要提供一種上述金屬殼體之成型方法。 200922711 種金屬成體，其包括底壁及由底壁向—側延伸 壁’該側壁經過鍛造成型而使其厚度大於底壁之厚度。 -種金屬殼體成型方法’其包括：將一金屬板拉 ； 型具有㈣和底壁之預成型殼體，且預成型殼體之側辟 和底壁之連接處為圓角結構；第一次鍛造成型，即藉： 第一成型模具對該預成型殼體進行第一次擠壓，使1 壁厚度變厚，且在側壁端部上形成第一擠壓斜面；第二 讀造成型，即藉由第二成型模具對該預成型殼體進行 :―次擠[使其侧壁厚度進—步變厚，且所述侧壁端 :乂形成與第一擠壓斜面相交之第二擠壓斜面，並將所 逑圓角結構成型為非圓角之連接結構；將該侧壁端部加 工成所需形狀，以形成金屬殼體。 =軏於習知技術，在所述金屬殼體及其成型方法 藉由鍛造成型使金屬殼體之側壁之厚度大於底壁之 f度’其生產效率尚’成本較低，且產品外觀較佳。 【實施方式】 下面將結合附圖及實施方式對金屬殼體及其成型方 法作進—步詳細說明。 凊參閲圖3及® 4,本發明較佳實施方式之金屬殼體 辟0為行動電話殼體，其包括—近似矩形之底壁21及由底 二U向一側延伸之第—侧壁22、第二侧壁23、第三側 24與第四側壁25。第一側壁22、第二側壁23、第三 側壁24及第四侧壁25順次連接。第—側壁22、第二側 8 200922711 壁23、第三側壁24及第四側壁25與底壁21共同形成一 具有-開口之腔體’且該第一側壁22、第二側壁23、第 二側壁24及第四側壁25與底壁21藉由锻造成型之連接 、口構ϋ相連’且第—側壁22、第二側壁23、第三側壁 ,第四侧壁25經過鍛造成型而使其厚度大於底壁u ^厚度纟本發明較佳實施方式中，底壁厚度為Κ， 弟：側壁22、第二侧壁23、第三側壁24及第四側壁25 =度二為Τ’第一側壁22、第二側壁。、第三侧壁μ 四側壁25之高度均為Η，則滿足以下關係： 1<Η/Κ<2.5。該金屬殼體20 &鋁合金殼體制 值9結構26為尖角結構，該尖角結構之夾角之取 之135⑨，且本發明中之所謂尖角指兩壁 .、尚ψ ^ 以之、，，°構，即不由圓弧面或者其他曲面 .^开:：理解，金屬殼體2〇之底壁亦可為三角形、五 ί接社構t形；Γ只要側壁數與底壁邊數對應即可。另， ===尖角結構，亦可為其他形狀鍛 請參閱圖5，A τ 23±5°C之溫戶條养 5052鋁合金為例，其在 200倍之全相;件下、4G〜8G%RH之濕度條件下，放大200922711. IX. INSTRUCTIONS: [Technical field to which the invention pertains] The present invention relates to a metal casing for a metal casing applied to an electronic device; = 2 is particularly relevant [Prior Art] /, μ method. In recent years, due to its good characteristics, the metal casing has been widely used for smashing, hardening, and wide-ranging applications. Please refer to Figure 1 for one of the fascinating telephones. in. The bottom side wall 12 including an approximately rectangular bottom, the first: (four) 13, the first side wall 12, the second side wall 13, and the third side: the wall 呤 姑 * 命 命 命 命 命 命 命 命 命 命 顺 顺 顺 顺 顺Formed together with the bottom wall 11 - the body is used to accommodate electronic components (not shown). 'There is an open cavity. The first side wall 12 of the cavity, the second side wall n, the second side wall 14 and the fourth side: a joint is generally designed as an H-angle structure, so that: genus, H) directly using metal plates The method of deep drawing is made: it reduces the manufacturing cost and the manufacturing difficulty. The need for the appearance of the T-th sub-device of the body is sometimes required to design the metal shell side wall 13, the third side wall 14, and the fourth side to be a non-81 corner connecting structure, such as a double corner, -. Structure. Due to the limitations of the deep drawing technology itself, it is difficult to directly draw the metal sheet into a ‘square=preparation. In addition, the thickness of the first sidewall 12, the second side 13, the second sidewall 14 and the fourth sidewall 15 of the metal casing 10 is equal to the thickness of the bottom wall η 200922711, which causes the first sidewall 12 and the second sidewall 13 to be formed. The strength of the second side wall 14 and the fourth side wall 14 is weak. Since the metal casing of the mobile phone and the like needs to be light and thin, it is usually made of a thin metal material. If the strength of the side wall is increased, the first side wall 13 and the third side of the metal casing 1 The thickness of the side wall 14 and the fourth side wall is greater than the thickness of the bottom wall 11, and the metal casing at this time is also difficult to prepare by direct drawing. In the prior art, the metal can be formed by die casting. case. However, it is formed by a method of forming tungsten, and the appearance quality of the metal casing is poor, and it is required to be polished to satisfy the appearance requirement. The production speed is slow and the cost is high. In addition, CNC machine tools can be used to form such metal casings, that is, the thicker plates are milled into a metal shell with a thick wall thickness of the side wall. Since the entire casing needs to be milled, it takes a long time. Therefore, the production efficiency is low, the cost is high, and it is not suitable for mass production. Figure 2 is not the metal material of the metal body obtained by the method described in the method of metal (using the commonly used AL5052 alloy as an example), under the condition of 23±5〇c ^ hunger, 40~80% RH Under humidity conditions, magnify 200 times to ^ map, the internal metallographic structure of the material is loose. Also, at 23±5. (: 2:degree condition, 40~8〇%RH under humidity conditions and 0.5kg test" lower 'its Vickers hardness value is 68~70. 【Abstract】 曰 曰; X上内谷,有It is necessary to provide a metal casing with a better appearance and a lower cost. In addition, it is also necessary to provide a molding method for the above metal casing. 200922711 A metal body including a bottom wall and a bottom wall- Side extension wall 'the side wall is forged to have a thickness greater than the thickness of the bottom wall. - A metal shell forming method 'includes: pulling a metal sheet; a preformed shell having a (four) and bottom wall, and The joint between the side wall and the bottom wall of the molded shell is a rounded structure; the first forging type, that is, by the first forming die, the preformed shell is firstly pressed to make the thickness of the 1 wall thicker. And forming a first pressing bevel on the end of the sidewall; the second reading type, that is, the second molding die: the sub-squeezing [the thickness of the sidewall is thickened step by step, and The sidewall end: the crucible forms a second extrusion bevel that intersects the first extrusion bevel, and The rounded corner structure is formed into a non-rounded connecting structure; the end of the side wall is processed into a desired shape to form a metal shell. = In the prior art, the metal shell and its forming method are borrowed The forging type makes the thickness of the side wall of the metal casing larger than the f degree of the bottom wall, and the production efficiency is still lower, and the appearance of the product is better. [Embodiment] The metal casing and the following will be described with reference to the accompanying drawings and embodiments. The molding method is described in detail. Referring to FIG. 3 and FIG. 4, the metal casing of the preferred embodiment of the present invention is a mobile phone casing, which comprises an approximately rectangular bottom wall 21 and a bottom second. The first side wall 22, the second side wall 23, the third side wall 24, and the fourth side wall 25 are sequentially connected to each other. The first side wall 22, the second side wall 24, the second side wall 24 and the fourth side wall 25 together with the bottom wall 21 form a cavity having an opening, and the first side wall 22, the second side wall 23, The two side walls 24 and the fourth side wall 25 and the bottom wall 21 are connected by forging, and the mouth is configured 'and the first side wall 22, the second side wall 23, the third side wall, and the fourth side wall 25 are forged to have a thickness greater than the bottom wall u ^ thickness. In the preferred embodiment of the present invention, the thickness of the bottom wall is Κ, 弟The side wall 22, the second side wall 23, the third side wall 24, and the fourth side wall 25=degree two are the first side wall 22 and the second side wall. The height of the third side wall μ side wall 25 is Η, then The following relationship is satisfied: 1 < Η / Κ < 2.5. The metal casing 20 & aluminum alloy casing value 9 structure 26 is a sharp-angled structure, the angle of the pointed structure is taken as 1359, and the so-called tip in the present invention The corner refers to the two walls., Shang Yi ^ with it,,, ° structure, that is, not by the arc surface or other curved surface. ^Open:: understand, the bottom wall of the metal shell 2〇 can also be triangular, T-shaped; Γ as long as the number of side walls corresponds to the number of sides of the bottom wall. In addition, === sharp corner structure, can also be for other shapes forging, please refer to Figure 5, A τ 23 ± 5 °C temperature households to raise 5052 aluminum alloy as an example, which is 200 times full phase; under the pieces, 4G ~8G%RH under humidity conditions, zoom in
經锻造之材質之㈣材責之内部金相組織比未 之、'”條：：之内部金相組織明顯細密。另，S 2WC 之，皿度條件下、4 〇〜8 〇 % r η十、玲十 驗力下，〜， 之濕度條件下及〇.5千克之試 可見相同：：:〇在側壁處表面之維氏硬度可…5, 貝經過鍛造後之維氏硬度比未經锻造時之 200922711 雉氏硬度有所增大。 °月參閱圖6至圖15，下面就本發明較佳實施方式之 金屬殼體20之成型方法作進—步詳細說明。—種用於製 造金屬殼體之成型方法包括以下步驟： 衣 ⑴拉深成型，請參閱圖6,即將一金屬板材拉深成 i為預成型殼Μ 30。在本實施中，該用於成型預成型殼 體30之金屬板材為鋁合金板材。該預成型殼體3〇包括 -近似矩形之底壁31及由底壁31邊緣向一側延 侧壁32 ’該多側壁32順次連接，並與底壁Μ共同形成 具有開口之腔體’且該多側壁32與底壁31之連接處為 圓角結構33。 … (2)第一次鍛造成型，即藉由第一成型模具200對 該預成型殼體30進行第一次擠壓，使預成型殼體3〇之 側壁32厚度變厚，且側壁32端部上形成第一擠壓斜面 321 (睛見圖1〇)。 請參閱圖5至圖8,在本發明較佳實施方式中，第一 成型模具200包括一上模210 ' 一下模22〇，一壓料板 230、一衝頭240、第一彈性件25〇及第二彈性件26〇。 該下模220與壓料板230設置於衝頭240兩側，且衝頭 24〇與下模220及壓料板23〇共同形成一用於容納預成型 殼體30之側壁32之模造型腔270,且模造型腔27〇之厚 度大於預成型殼體30之側壁32之厚度。該上模21〇設 置於下模220、壓料板230及衝頭240上方，第—彈性件 250及第二彈性件26〇為壓縮彈簧，其中第一彈性件25〇 10 200922711 • 用於支撐下模220，第二彈性件260用於支撐壓料板 • 230。上模210下端為工作面2101，其用於鍛造成型時對 ' 預成型殼體30之底壁31施力，下模220上端為一安裝 面2201，用於安裝預成型殼體30，壓料板230包括一側 面2301及一與侧面2301垂直之上表面2302，侧面2301 鄰近上端處形成有一突起部2303，該突起部2303上設有 抵壓面2304，其用於鍛造成型時抵壓預成型殼體30之侧 壁31，抵壓面2304與上模之工作面2101相互垂直，且 平行於侧面2301。 衝頭240依次設有一衝壓部2401及一台階部2402。 衝壓部2401上設置有一第一侧面2404、一第二侧面2405 及一工作斜面2406。第一側面2404與第二側面2405相 互平行，第一側面2404與第二侧面2405之間之寬度為 Li，若最終所需成型金屬殼體20之侧壁之厚度為T，則 0.7Τ€Ζ^$0·9Τ，最為理想之取值是Ζ^ = 0.8Τ~0·85Τ。工 作斜面2406兩端分別與第一侧面2404及第二侧面2405 相連，且工作斜面2406與第二侧面2405相連之一端之 高度低於工作斜面2406與第一侧面2404相連之一端， 即工作斜面2406朝第一側面2404傾斜，工作斜面2406 與第一側面2404之夾角為β!，且45度S Pi S 70度，最 為理想之取值是β1 = 60〜65度。台階部2402用於壓料板 230移動定位，其上設置有一定位面2403。 在成型前，壓料板230之上表面2302與下模220之 安裝面2201之垂直距離大於預成型殼體30之底壁31厚 11 200922711 - 度，壓料板230之突起部2303之抵壓面2304抵持於衝 頭240之衝壓部2401之第二侧面2405，壓料板230之侧 • 面203抵持於衝頭240之台階部2402，且壓料板230之 突起部2303下端距離衝頭240之台階部2402之定位面 2403之間有一定間隙，然後將預成型殼體30置於下模 220上，且使預成型殼體30之侧壁32容納於模造型腔 270 ° 在第一次鍛造成型時，首先上模210抵壓壓料板230 之上表面2302及預成型殼體30之底壁31，如此下模220 及壓料板230將被下壓，即第一彈性件及第二彈性件260 均被壓縮。由於預成型殼體30之側壁32容納於模造型 腔270，在下模220及壓料板230將被下壓之過程中，預 成型殼體30之侧壁32之材質與衝頭240之工作斜面2406 產生冷擠壓，使預成型殼體30之材質在模造型腔270内 產生流動。當壓料板230之突起部2303抵持衝頭240之 台階部2402之定位面2403時，由於衝頭240之台階部 2402之定位作用，下模220及壓料板230將停止移動。 在冷擠壓過程中，預成型殼體30之材質將整模造型腔270 充滿，由於模造型腔270之厚度大於預成型殼體30之侧 壁之厚度，故可使預成型殼體30之侧壁32變厚，且預 成型殼體30之侧壁32與底壁31之連接處之圓角結構33 將被初步尖角化，此外，由於衝頭240之工作斜面240 之作用，使預成型殼體30之侧壁32端部上形成第一擠 壓斜面321。 12 200922711 (3 )第二次鍛造成型，即藉由第二成型模具300對該 預成型殼體進行第二次擠壓，使預成型殼體30之側壁32 之厚度進一步變厚，且預成型殼體30之側壁32之端部 上形成與第一擠壓斜面321相交之第二擠壓斜面322，並 將所述圓角結構33成型為非圓角之連接結構26，在本實 施方式中即成型出尖角結構。 請參閱圖11至圖14，在本發明較佳實施方式中，第 二成型模具300包括一上模310、一下模320，一壓料板 330、一衝頭340、第一彈性件350及第二彈性件360。 除衝頭340外，第二成型模具300之其他結構與第一成 型模具200結構基本相同，所以下面僅對衝頭340作詳 細描述。 衝頭340依次設置有一衝壓部3401及一台階部 3402。衝壓部3401上設置有一第一侧面3404、一第二侧 面3405及一工作斜面3406。第一侧面3404與第二侧面 3405相互平行，第一側面3404與第二側面3405之間之 寬度為，若最終所需成型金屬殼體20之側壁之厚度為 T ，則L2 = T。工作斜面3406兩端分別與第一侧面3404 及第二側面3405相連，且工作斜面3406與第二侧面3405 相連之一端之高度高於工作斜面3406與第一侧面3404 相連之一端，即工作斜面3406朝第二側面3405傾斜， 工作斜面3406與第二側面2404之夾角為β2，且45度 70度，最為理想之取值是β1 = 60〜65度。台階部3402 用於壓料板330移動定位，其上設置有一定位面3403。 13 200922711 衝頭340可與下模320及壓料板330之間共同形成一模 造型腔370由於模造型腔370之厚度大於預成型殼體30 之側壁之厚度，且模造型腔370之厚度大於預成型殼體 30之侧壁32之厚度。 在第二次鍛造成型時，當上模3.10下壓下模320及 壓料板330時，預成型殼體30之侧壁32之材質與衝頭 340之工作斜面3406產生冷擠壓，使預成型殼體30之材 質在模造型腔370内產生流動。當壓料板330抵持衝頭 340之台階部3402之定位面3403時，由於衝頭340之台 階部3402之定位作用，下模320及壓料板330將停止移 動。在冷擠壓過程中，預成型殼體30之材質將整模造型 腔370充滿，由於模造型腔370之厚度大於預成型殼體 30之侧壁之厚度，故可使預成型殼體30之侧壁32變厚， 且預成型殼體30之侧壁32與底壁31之連接處之圓角結 構33將被成型為非圓角之連接結構26，此外，由於衝頭 340之工作斜面340之作用，使預成型殼體30之侧壁32 端部上形成第二擠壓斜面322。 (4 )藉由數控機床將預成型殼體30之側壁32端部 加工成所需形狀，以形成金屬殼體20，在本實施方式中 是將殼體30之侧壁32端部上形成之第一擠壓斜面321 及第二擠壓斜面3 22銑成平面。 可以理解，請參閱圖15，在步驟（3 )與（4 )之間， 還可藉由一精修模具400對預成型殼體30之側壁32進 行精修，以使侧壁32獲得更好之外觀效果。精修模具400 14 200922711 包括：上模401、—下模4〇2及一壓料板4〇3。成型時， 用壓料板403將預成型殼體3〇固定於下模他上，且 預成型殼體30之側壁32伸出下模4〇2，當上模術下壓 可去除預成型殼體30之側壁32上之部分材質以獲 取更好之外觀效果。 綜上所述，本發明符合發明專利要件， 專利申請。惟，以上所述者僅為本發明之較佳實施方= 本發明之範圍並不以上述實施方式為限，舉凡孰悉本案 技蟄之人士’於援依本案發明精神所作之等效修飾或變 化，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】 圖1係習知電子裝置用金屬殼體之立體示意圖。 圖2係用於製造圖1電子裝置用金屬殼體之金屬材質 放大200倍之金相圖； 、 圖3係本發明較佳實施方式之金屬殼體立體示意圖。 圖4係本發明較佳實施方式（金屬殼體之連接結構處 之局部剖示圖。 圖5係本發明較佳實施方式之金屬殼體於側壁處之金 屬材質放大200倍之金相圖。 圖6係本發明較佳實施方式之金屬殼體成型方法中之 預成型殼體之立體示意圖。 圖7係本發明較佳實施方式之金屬殼體成型方法所採 用之第一成型模具之剖面示意圖。 圖8是本發明較佳實施方式之金屬殼體成型方法所採 15 200922711 用之第《型杈具之衝頭之剖面示意圖。 圖9係本發明較佳實施方式之金屬殼體成型方法所採 成型模具對預成型殼體進行鍛造成型時之局部 剖面示意圖。 σ| 圖圖10係第一次鍛造成型後之預成型殼體之局部剖示 圖11係本發明較佳實施方式之金屬殼體成型方法所採 第二成型模具之局部剖面示意圖。 圖12係本發明較佳實施方式之金屬殼體 採用之第广成型模具之衝頭之剖面示意圖。方法所 採用？1係本發明幸父佳實施方式之金屬殼體成型方法所 部剖二成型模具對預成型殼體進行锻造成型時之局 圖圖14係第：絲造成型後之預成型殼體之局部剖示 用 圖 圖15係本發明較佳實施方式之金屬殼體成型 之精修模具對預成型殼體進行精修時之局部剖 方法採 面示意 主要元件符號說明】 金屬殼體 20 弟一側壁 22 第三側壁 24 連接結構 26 側壁 32 底壁 21 ’ 31 苐二側壁 23 第四側壁 25 預成型殼體 30 圓角結構 33 16 310 200922711 第一擠壓斜面 321 第二擠壓斜面 322 第一成型模具 200 上模 210， 下模 220 ， 320 壓料板 230 · 衝頭 240 ， 340 第一彈性件 250， 第二彈性件 260 ， 360 模造型腔 270， 工作面 2101 側面 2301 上表面 2302 突起部 2303 抵壓面 2304 衝壓部 2401 台階部 2402 ， 3402 定位面 2403 第一侧面 2404 ， 3404 第二侧面 2405 工作斜面 2406 ， 3406 第二成型模具 300 精修模具 400 上模 401 下模 402 壓料板 403 330 350 370 ，3401 ，3403 ，3405 17The internal metallographic structure of the forged material (4) is less than that of the original metallographic structure. The internal metallographic structure of the material is obviously fine. In addition, under the condition of S 2WC, 4 〇~8 〇% r η Under the ten test force of Ling 10, under the humidity condition and the test of 〇.5 kg, the same can be seen::: The Vickers hardness of the surface at the side wall can be...5, the Vickers hardness ratio of the shell after forging is not forged At the time of 200922711, the hardness of the steel is increased. Referring to Figures 6 to 15, the following is a detailed description of the molding method of the metal casing 20 of the preferred embodiment of the present invention. The forming method of the body comprises the following steps: The garment (1) is drawn deep, please refer to Figure 6, which is to draw a metal sheet into a preformed shell 30. In the present embodiment, the metal used to form the preformed shell 30 The sheet metal is an aluminum alloy sheet. The preformed casing 3 includes an approximately rectangular bottom wall 31 and a side wall 32' extending from the edge of the bottom wall 31 to the side wall 32'. The plurality of side walls 32 are sequentially connected and formed together with the bottom wall Μ The open cavity 'and the junction of the multi-side wall 32 and the bottom wall 31 is a rounded structure 3 3. (2) The first forging type, that is, the first molding die 200 is first pressed by the first molding die 200, so that the thickness of the side wall 32 of the preformed casing 3 is thickened, and the side wall is thickened. A first pressing bevel 321 is formed on the end portion of the 32 (see FIG. 1A). Referring to FIGS. 5 to 8, in a preferred embodiment of the present invention, the first molding die 200 includes an upper die 210'.压, a pressure plate 230, a punch 240, a first elastic member 25〇 and a second elastic member 26〇. The lower mold 220 and the pressure plate 230 are disposed on both sides of the punch 240, and the punch 24〇 The lower mold 220 and the binder plate 23 together form a molding cavity 270 for receiving the side wall 32 of the preformed casing 30, and the thickness of the molding cavity 27 is greater than the thickness of the side wall 32 of the preformed casing 30. The upper mold 21 is disposed above the lower mold 220, the pressure plate 230 and the punch 240. The first elastic member 250 and the second elastic member 26 are compression springs, wherein the first elastic member 25〇10 200922711 • is used for supporting The mold 220, the second elastic member 260 is used to support the binder plate 230. The lower end of the upper mold 210 is a working surface 2101, which is used for forging forming The bottom wall 31 of the body 30 is biased. The upper end of the lower mold 220 is a mounting surface 2201 for mounting the preformed housing 30. The pressing plate 230 includes a side surface 2301 and a surface 2302 perpendicular to the side surface 2301. The side surface 2301 is adjacent to A protrusion portion 2303 is formed at the upper end, and the protrusion portion 2303 is provided with a pressing surface 2304 for pressing the side wall 31 of the preformed casing 30 during the forging type, and the pressing surface 2304 and the working surface 2101 of the upper mold are mutually Vertically, and parallel to the side surface 2301. The punch 240 is sequentially provided with a punching portion 2401 and a step portion 2402. The first side surface 2404, a second side surface 2405 and a working slope 2406 are disposed on the stamping portion 2401. The first side 2404 and the second side 2405 are parallel to each other, and the width between the first side 2404 and the second side 2405 is Li. If the thickness of the side wall of the final formed metal casing 20 is T, 0.7Τ€Ζ ^$0·9Τ, the most ideal value is Ζ^ = 0.8Τ~0·85Τ. The working slopes 2406 are respectively connected to the first side 2404 and the second side 2405, and the height of one end of the working slope 2406 and the second side 2405 is lower than one end of the working slope 2406 and the first side 2404, that is, the working slope 2406 Tilting toward the first side 2404, the angle between the working bevel 2406 and the first side 2404 is β!, and 45 degrees S Pi S 70 degrees, and most preferably β1 = 60~65 degrees. The step portion 2402 is used for moving positioning of the pressing plate 230, and a positioning surface 2403 is disposed thereon. Before forming, the vertical distance between the upper surface 2302 of the pressure plate 230 and the mounting surface 2201 of the lower mold 220 is greater than the thickness of the bottom wall 31 of the preformed casing 30 by 11 200922711 degrees, and the protrusion 2303 of the pressure plate 230 is pressed. The surface 2304 is abutted against the second side 2405 of the stamping portion 2401 of the punch 240. The side surface 203 of the pressure plate 230 abuts against the step portion 2402 of the punch 240, and the lower end of the protrusion 2303 of the pressure plate 230 is distanced. There is a gap between the positioning faces 2403 of the step portion 2402 of the head 240, and then the preformed housing 30 is placed on the lower mold 220, and the side wall 32 of the preformed housing 30 is received in the molding cavity 270 ° When the forging type is first, the upper mold 210 first presses the upper surface 2302 of the pressing plate 230 and the bottom wall 31 of the preformed casing 30, so that the lower mold 220 and the pressing plate 230 are pressed down, that is, the first elastic member. And the second elastic members 260 are both compressed. Since the side wall 32 of the preformed casing 30 is received in the molding cavity 270, the material of the side wall 32 of the preformed casing 30 and the working bevel of the punch 240 during the process of pressing the lower die 220 and the binder 230 are pressed. 2406 produces a cold extrusion that causes the material of the preformed housing 30 to flow within the molding cavity 270. When the projection 2303 of the pressure plate 230 abuts against the positioning surface 2403 of the step portion 2402 of the punch 240, the lower mold 220 and the pressure plate 230 will stop moving due to the positioning action of the step portion 2402 of the punch 240. During the cold extrusion process, the material of the preformed housing 30 fills the entire molding cavity 270. Since the thickness of the molding cavity 270 is greater than the thickness of the sidewall of the preformed housing 30, the preformed housing 30 can be The sidewall 32 is thickened and the fillet structure 33 at the junction of the sidewall 32 of the preformed housing 30 and the bottom wall 31 will be initially sharpened and, in addition, due to the action of the working ramp 240 of the punch 240, A first pressing bevel 321 is formed on an end of the side wall 32 of the molded casing 30. 12 200922711 (3) The second forging type, that is, the second molding die 300 is secondarily pressed by the second molding die 300 to further thicken the thickness of the side wall 32 of the preformed casing 30, and preformed. A second pressing bevel 322 intersecting the first pressing bevel 321 is formed on the end of the side wall 32 of the housing 30, and the rounded structure 33 is formed into a non-rounded connecting structure 26, in this embodiment That is, a sharp corner structure is formed. Referring to FIG. 11 to FIG. 14 , in a preferred embodiment of the present invention, the second molding die 300 includes an upper die 310 , a lower die 320 , a pressing plate 330 , a punch 340 , a first elastic member 350 , and a first molding die 300 . Two elastic members 360. The other structure of the second molding die 300 is substantially the same as that of the first molding die 200 except for the punch 340, so only the punch 340 will be described in detail below. The punch 340 is provided with a punching portion 3401 and a step portion 3402 in this order. The first side surface 3404, a second side surface 3405 and a working slope 3406 are disposed on the stamping portion 3401. The first side 3404 and the second side 3405 are parallel to each other, and the width between the first side 3404 and the second side 3405 is such that if the thickness of the side wall of the final formed metal casing 20 is T, then L2 = T. The working bevel 3406 has two ends connected to the first side 3404 and the second side 3405 respectively, and the height of one end of the working bevel 3406 and the second side 3405 is higher than one end of the working bevel 3406 and the first side 3404, that is, the working bevel 3406 Tilting toward the second side 3405, the angle between the working bevel 3406 and the second side 2404 is β2, and 45 degrees 70 degrees, and most preferably β1 = 60~65 degrees. The step portion 3402 is used for moving positioning of the pressure plate 330, and a positioning surface 3403 is disposed thereon. 13 200922711 The punch 340 can form a molding cavity 370 with the lower die 320 and the binder plate 330. Since the thickness of the molding cavity 370 is greater than the thickness of the sidewall of the preformed casing 30, and the thickness of the molding cavity 370 is greater than The thickness of the side wall 32 of the preformed housing 30. In the second forging type, when the die 320 and the binder plate 330 are pressed down by the upper die 3.10, the material of the side wall 32 of the preformed casing 30 and the working bevel 3406 of the punch 340 are cold-extruded to make a pre-form. The material of the molded casing 30 creates a flow in the molding cavity 370. When the pressure plate 330 abuts against the positioning surface 3403 of the step portion 3402 of the punch 340, the lower mold 320 and the pressure plate 330 will stop moving due to the positioning action of the step portion 3402 of the punch 340. During the cold extrusion process, the material of the preformed housing 30 fills the entire molding cavity 370. Since the thickness of the molding cavity 370 is greater than the thickness of the sidewall of the preformed housing 30, the preformed housing 30 can be The sidewall 32 is thickened and the fillet structure 33 at the junction of the sidewall 32 of the preformed housing 30 and the bottom wall 31 will be formed into a non-rounded connection 26 and, in addition, due to the working ramp 340 of the punch 340 The second extrusion rib 322 is formed on the end of the side wall 32 of the preformed housing 30. (4) The end portion of the side wall 32 of the preformed casing 30 is machined into a desired shape by a numerically controlled machine tool to form a metal casing 20, which is formed on the end portion of the side wall 32 of the casing 30 in this embodiment. The first pressing bevel 321 and the second pressing bevel 3 22 are milled into a plane. It can be understood that, referring to Fig. 15, between steps (3) and (4), the side wall 32 of the preformed casing 30 can also be finished by a finishing mold 400 to make the side wall 32 better. The appearance of the effect. The refining mold 400 14 200922711 includes: an upper mold 401, a lower mold 4〇2, and a pressure plate 4〇3. During molding, the preformed housing 3 is fixed to the lower mold by a press plate 403, and the side wall 32 of the preformed housing 30 extends out of the lower mold 4〇2, and the preformed shell can be removed when the upper mold is pressed down. Part of the material on the side wall 32 of the body 30 for better appearance. In summary, the present invention complies with the invention patent requirements and patent applications. However, the above is only the preferred embodiment of the present invention. The scope of the present invention is not limited to the above embodiments, and those skilled in the art will be able to modify the equivalent of the invention in the spirit of the invention. Changes are to be included in the scope of the following patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a metal case for a conventional electronic device. 2 is a metallographic view of a metal material of a metal casing for the electronic device of FIG. 1 enlarged by 200 times; and FIG. 3 is a perspective view of a metal casing according to a preferred embodiment of the present invention. 4 is a partial cross-sectional view showing a connection structure of a metal casing according to a preferred embodiment of the present invention. FIG. 5 is a metallographic diagram in which a metal material of a metal casing at a side wall of the preferred embodiment of the present invention is magnified 200 times. 6 is a perspective view of a preformed casing in a metal shell forming method according to a preferred embodiment of the present invention. FIG. 7 is a cross-sectional view showing a first forming mold used in a metal shell forming method according to a preferred embodiment of the present invention. Figure 8 is a cross-sectional view of a punch of a type of cookware used in a method of forming a metal shell according to a preferred embodiment of the present invention. Figure 9 is a perspective view of a metal shell forming method according to a preferred embodiment of the present invention. FIG. 10 is a partial cross-sectional view of a preformed housing after the first forging type. FIG. 11 is a partial view of a preformed housing of the preferred embodiment of the present invention. FIG. FIG. 12 is a schematic cross-sectional view showing a second molding die of a metal casing according to a preferred embodiment of the present invention. The first embodiment of the metal shell forming method of the embodiment of the invention is a forging frame of the preformed casing. FIG. 14 is a pre-formed shell of the wire-forming type. FIG. 15 is a partial cross-sectional view of a finishing mold of a metal shell molded by a preferred embodiment of the preferred embodiment of the present invention. FIG. 15 is a partial cross-sectional view of the main component. Side wall 22 third side wall 24 connection structure 26 side wall 32 bottom wall 21 ' 31 second side wall 23 fourth side wall 25 preformed housing 30 rounded structure 33 16 310 200922711 first pressing bevel 321 second pressing bevel 322 first Mold 200 Upper mold 210, lower mold 220, 320 pressure plate 230 · Punch 240, 340 First elastic member 250, second elastic member 260, 360 molding cavity 270, working surface 2101 side 2301 upper surface 2302 protrusion 2303 Pressing surface 2304 Stamping part 2401 Step part 2402, 3402 Positioning surface 2403 First side 2404, 3404 Second side 2405 Working bevel 2406, 3406 Second forming die Finishing mold 300 400 401 an upper mold die 402 lower pressure plate 403 330 350 370, 3401, 3403, 340 517