-1317306 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及其成型方法，尤其係關 於一種應用於電子裝置之金屬殼體及其成型方法。 【先前技術】 近年來，金屬殼體由於其具有強度高、硬度好、質 感佳等特點，被廣泛應用於行動電話等電子裝置中。 請參閱圖1，一種用於電子裝置之金屬殼體ι〇，其 包括一近似矩形之底壁11及自底壁只向一側延伸之第二 側壁12、第二側壁13、第三侧壁14與第四侧壁15。第 一側壁、第二側壁13、第三側壁14及第四側壁15順 次連接，並與底壁n共同形成一具有一開口之腔體。腔 體用以谷置電子元件（圖未示）。 第-侧壁12、第二侧壁13、第三側壁14及第四侧 人=與底壁11之連接處-般設計為圓角結構，如此便於 至屬殼體10採用金屬板材直接拉深成型之方式 降低製造成本與製造難度。 、 由於電子裝置外觀之需要，有時需要將金屬殼 2、第二側壁13、第三側壁14及第四側 i 15與底壁n之連接處設計為非圓角之連 1角結構。由於拉深成型技術本身之限制，尖二；二 =角之連接結構較難採用金屬板材直接拉深成型 式製備。此外，上述金屬殼體10之第—側壁 壁13、第三侧壁14與第四側壁15之厚度等於底壁2 6 1317306 厚度相等’如此會造成第一側壁# ==側壁14之強度較弱。由:=話= 子裝置之金屬设體需要輕薄短小，故 製；生，总兔摇吊採用金屬ί寻材 壁u、第二^ 強度’而使金屬殼體10之第—側 •土 13、第二側壁14與第四側壁14之厚产 接:度:則此時之金屬殼體同樣難以藉由直 之方法形成兮，式製備，在習知技術中可採用壓鑄成型 成金屬殼體。然，藉由壓鎢成型之方法形 成之金屬殼體其外勸σ暂齡兰 兩 外顴H，、u Π口質較差，兩要經過拋光方能滿足 、 &生產速度慢，成本較高。此外，還可採 :控：床加工形成該類金屬殼體，即將較厚之板材銑 ,工侧壁厚度底壁厚度大之金屬殼體，由於整殼體 1 需要銳削加工，其耗費之時間相當長，故生產效率ς 成本报鬲，不適合大批量生產。 圖2所示為採用上述方法加工得到之金屬殼體之側壁 •處=金屬材質（以常用之also52紹合金為例），在23±s〇c 之溫度條件下、40〜8〇%RH之濕度條件下，放大倍之 金相圖，該材質之内部金相組織較為鬆散。另，在23±5Υ 之溫度條件下、40〜8〇%RH之濕度條件下及〇5千克之試 驗力下’其維氏硬度值為68〜70。 【發明内容】 鑒於以上内谷，有必要提供一種具有較佳外觀品 質、且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。 1317306 .-種金屬殼體’其包括底壁及由底壁向一側延伸 .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；成 ’具有側壁和底壁之預成型殼體，且預成型殼體之側壁 =底壁之連接處為圓角結構；第—次锻造成型，即藉由 第一成型模具對該預成型殼體進行第一次擠壓， :厚度變厚，且在側壁端部上形成第一擠壓斜面；第二 | =锻&成型’即藉由第二成型模具對該預成型殼體進行 =二次擠壓，使其㈣厚度進—步變厚，且所述側 π切成與第-播壓斜面相交之第二擠壓斜面，並將所 、述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。 相較於習知技術，在所述金屬殼體及其成型方法 严ρ藉由锻造成型使金屬㉟體之侧壁之厚度大於底壁之 .:又其生產效率高，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 忐作進一步詳細說明。 請參閱圖3及圖4’本發明較佳實施方式之金屬殼體 壁^丁動電話殼體’其包括一近似矩形之底壁21及由底 ί 24 :―側延伸之第一側壁22、第二側壁23、第三側 ”第四側壁25。第一側壁22、第二側壁Μ、第三 24及第四側壁25順次連接。第一側壁22、第二側 8 !317306 壁23、第三侧壁24及第四側壁25與底壁2ι乒 具有—開口之腔體，且該第—側壁22、第二側、壁U、= :側壁24及第四側壁25與底壁21藉由鍛造成型之 二構26相連，且第一側壁22、第二側壁23、第三側辟 4及第四側壁25經過锻造成型而使其厚度大於底壁= &度。在本發明較佳實施方式中，底壁21厚度為&， :二壁22、第二側壁23、第三側壁24及第四侧壁Μ =度均為Τ’第一侧壁22、第二側壁23、第三側壁以 1<Τ/Κ四:則壁25之冋度均為Η，則滿足以下關係： 士肌心。該金屬殼體20心合金殼體制 接結構26為尖角結構，該尖角結構之夾角之取 之；=度至1351’且本發明中之所謂尖角指兩壁 ” 滑過渡之結構，即不由圓弧面或者其他曲面 π以理解’金屬殼體20之底壁亦可為三角形、五 ㈣/、邊形等，只要側壁數與底壁邊數對應即可。另， 不限於尖角結構，亦可為其他形狀之藉由鍛 造成型之連接結構。 23+5^^5’以常用之祀松銘合金為例，其在 2舒之tr度條件下、40〜卿邮之濕度條件下，放大 詩止ttl®，該經過锻造之材質之内部金相組織比未 ::二佟件貝之内部金相組織明顯細密。另，* 23±5°c 下、♦卿RH之濕度條件下及。,5千克之試 :ί:π设體20在側壁處表面之維氏硬度W, 可見相同之材質經㈣造後之以硬纽未絲造時之 9 1317306 雄氏硬度有所增大。 請參閱圖6至圖15，nr ; μ丄BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal casing and a molding method thereof, and more particularly to a metal casing applied to an electronic device and a molding method therefor. [Prior Art] In recent years, metal casings have been widely used in electronic devices such as mobile phones because of their high strength, good hardness, and good texture. Referring to FIG. 1 , a metal casing 用于 for an electronic device includes an approximately rectangular bottom wall 11 and a second sidewall 12 , a second sidewall 13 , and a third sidewall extending from one side of the bottom wall to only one side. 14 and fourth side wall 15. The first side wall, the second side wall 13, the third side wall 14, and the fourth side wall 15 are sequentially connected, and together with the bottom wall n form a cavity having an opening. The cavity is used to store electronic components (not shown). The joint of the first side wall 12, the second side wall 13, the third side wall 14, and the fourth side person = the bottom wall 11 is generally designed as a rounded structure, so that the shell 10 is directly drawn by the metal plate. Forming reduces manufacturing costs and manufacturing difficulties. Due to the appearance of the electronic device, it is sometimes necessary to design the connection between the metal shell 2, the second side wall 13, the third side wall 14, and the fourth side i 15 and the bottom wall n as a non-rounded corner structure. Due to the limitations of the deep drawing technology itself, the tip two; two = angle connection structure is difficult to prepare by direct drawing of the metal sheet. In addition, the thickness of the first sidewall wall 13, the third sidewall 14 and the fourth sidewall 15 of the metal casing 10 is equal to the thickness of the bottom wall 2 6 1317306. This causes the first sidewall #==the strength of the sidewall 14 is weak. . By: = words = the metal device of the sub-device needs to be light and short, so the system; the raw rabbit shakes the metal to the wall u, the second ^ strength ' to make the metal shell 10 - side - soil 13 The thickness of the second side wall 14 and the fourth side wall 14 is: The metal shell at this time is also difficult to form by a straight method, and can be formed into a metal shell by die casting in the prior art. However, the metal shell formed by the method of tungsten molding is advised to have a smear of the outer smear, and the sputum is poor. The two are polished to meet the requirements, and the production speed is slow and the cost is high. . In addition, it can also be controlled: the bed processing forms such a metal shell, that is, the thicker plate is milled, and the metal shell with the thickness of the bottom wall of the working side wall is sharp, and the whole casing 1 needs sharp processing, which consumes The time is quite long, so the production efficiency 成本 cost report is not suitable for mass production. Figure 2 shows the side wall of the metal shell processed by the above method. = metal material (for example, commonly used as the alloy), under the temperature condition of 23±s〇c, 40~8〇%RH Under the condition of humidity, the metallographic diagram of the magnification is loose, and the internal metallographic structure of the material is loose. Further, under a temperature condition of 23 ± 5 Torr, a humidity of 40 to 8 % RH, and a test force of 〇 5 kg, the Vickers hardness value was 68 to 70. SUMMARY OF THE INVENTION In view of the above inner valleys, it is necessary to provide a metal casing having a better appearance quality and a lower cost. It is also necessary to provide a method of forming the above metal casing. 1317306. A metal casing 'includes a bottom wall and a wall extending from one side of the bottom wall to the side, the side wall being forged to a thickness greater than the thickness of the bottom wall. a metal shell forming method, comprising: pulling a metal plate; forming a preformed shell having a side wall and a bottom wall, and a side wall of the preformed shell = a joint of the bottom wall is a rounded structure; Forging type, that is, the first molding is performed by the first molding die, the thickness is thickened, and the first pressing bevel is formed on the end of the side wall; the second |=forging & molding That is, the pre-formed shell is subjected to = secondary extrusion by a second molding die so that the thickness of (4) is further thickened, and the side π is cut into a second extruded bevel that intersects with the first weft bevel. And forming the rounded structure into a non-rounded connecting structure; adding the sidewall end to a desired shape to form a metal casing. Compared with the prior art, in the metal casing and the forming method thereof, the thickness of the side wall of the metal 35 body is larger than that of the bottom wall by the forging type: the production efficiency is high, the cost is low, and the product The appearance is better. [Embodiment] Hereinafter, a metal casing and a molding die thereof will be described in further detail with reference to the accompanying drawings and embodiments. Referring to FIG. 3 and FIG. 4, a metal housing wall of a preferred embodiment of the present invention includes an approximately rectangular bottom wall 21 and a first side wall 22 extending from the bottom side. The second side wall 23, the third side "fourth side wall 25. The first side wall 22, the second side wall Μ, the third 24 and the fourth side wall 25 are sequentially connected. The first side wall 22, the second side 8! 317306 wall 23, the first The three side walls 24 and the fourth side wall 25 and the bottom wall 2 ping have an open cavity, and the first side wall 22, the second side, the wall U, the = side wall 24, and the fourth side wall 25 and the bottom wall 21 are The forged two structures 26 are connected, and the first side wall 22, the second side wall 23, the third side wall 4 and the fourth side wall 25 are forged to have a thickness greater than the bottom wall = & degree. In the mode, the thickness of the bottom wall 21 is &, the two walls 22, the second side wall 23, the third side wall 24, and the fourth side wall Μ = degrees are Τ 'first side wall 22, second side wall 23, third The side wall is 1 < Τ / Κ 4: the width of the wall 25 is Η, then the following relationship is satisfied: 士肌心. The metal shell 20 core alloy shell joint structure 26 is a pointed structure, the tip The angle of the angular structure is taken; = degree to 1351' and the so-called sharp angle in the present invention refers to the structure of the two-wall sliding transition, that is, the arc surface or other curved surface π is not understood to understand the bottom wall of the metal casing 20 It may be a triangle, a five (four)/, a side, or the like, as long as the number of side walls corresponds to the number of sides of the bottom wall. Further, it is not limited to the pointed corner structure, and may be a connection structure of other shapes by forging. 23+5^^5' Take the commonly used 祀松铭合金 as an example. Under the condition of 2 Shu's tr degree, 40~ Qingmail's humidity condition, enlarge the poem stop ttl®, the inner gold of the forged material The phase ratio is not as follows:: The internal metallographic structure of the two pieces is obviously fine. In addition, * 23 ± 5 ° c, ♦ Qing RH under the humidity conditions. , 5 kg test: ί: π set the body 20 at the surface of the wall at the Vickers hardness W, can be seen that the same material by (4) after the hard to create silk 9 1317306 male hardness has increased. Please refer to Figure 6 to Figure 15, nr; μ丄
Mr-m 、 下面就本發明較佳實施方式之 、1今<成型方法作進—步詳細說明。-種用於製 、金屬设體之成型方法包括以下步驟： 剞丄:、拉'Γ成1明參閱圖6 ’即將-金屬板材拉深成 許in ④體3G °在本實施_，該用於成型預成型殼 二之、屬板材為紹合金板材。該預成型殼體3〇包括 一近似矩形之底壁31及由底壁31邊緣向—側延伸之多 側土 32，該多側壁32順次連接，並與底壁31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2〇〇對 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 (請見圖10)。Mr-m, the following is a detailed description of the preferred embodiment of the present invention. - The forming method for the metal body and the metal body includes the following steps: 剞丄:, pull 'Γ成1 明明 Refer to Figure 6 'Coming soon - the metal sheet is drawn into the in 4 body 3G ° in this embodiment _, the use In the molding of the preformed shell II, the plate is a Shao alloy sheet. The preformed housing 3 includes an approximately rectangular bottom wall 31 and a plurality of side walls 32 extending laterally from the edge of the bottom wall 31. The plurality of side walls 32 are sequentially connected and form a cavity having an opening together with the bottom wall 31. 'And the junction of the multi-side wall 32 and the bottom wall 31 is a rounded structure 33. (2) The first forging type, that is, the first molding die 30 is first pressed by the first molding die 2, so that the thickness of the side wall 32 of the preformed casing 3 is thickened, and the side wall 32 is thickened. A first pressing bevel 321 is formed on the end (see Fig. 10).
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 240與下模220及壓料板230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，第一彈性件 250及第二彈性件260為壓縮彈簧’其中第一彈性件250 * 1317306 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及一與側面2301垂直之上表面2302，側面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 *平行於側面2301。 衝頭240依次設有一衝壓部2401及一台階部2402。 衝壓部2401上設置有一第一側面2404、一第二側面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與第二側面2405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 0.7Τ$Ζ^$〇.9Τ，最為理想之取值是Ζ^ = 0.8Τ〜0.85T。工 鲁作斜面2406兩端分別與第一側面2404及第二側面2405 相連，且工作斜面2406與第二側面2405相連之一端之 高度低於工作斜面2406與第一側面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 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 1317306 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之侧壁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之側壁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之側 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之側壁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 1317306 (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 鲁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上設置有一第一側面3404、一第二側 面3405及一工作斜面3406。第一侧面3404與第二側面 籲 3405相互平行，第一側面3404與第二侧面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12 = 11。工作斜面3406兩端分別與第一側面3404 及第二侧面3405相連，且工作斜面3406與第二側面3405 相連之一端之高度高於工作斜面3406與第一側面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 $β2$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 • 1317306 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之側壁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之側壁32變厚， 且預成型殼體30之側壁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 籲 340之工作斜面340之作用，使預成型殼體30之側壁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之侧壁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之側壁32端部上形成之第一擠壓斜面321 及第二擠壓斜面322銳成平面。 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 • 1317306 包括一上模401、一下模402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4〇2上，且使 •預成型殼體30之側壁32伸出下模4〇2,當上模4〇1下壓 ，時，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。 、又 綜上所述，本發明符合發明專利要件，爰依法提出 專利申請。惟，以上所述者僅為本發明之較佳實施方式， 鲁本發明之範圍並不以上述實施方式為限，舉凡熟悉本案 技藝之人士，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i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。 擊 11 4係本發明較佳實施方式之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 -1317306 用之第一成型模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 用之第一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。 圖10係第一次鍛造成型後之預成型殼體之局部剖示 圖0 圖11係本么明較佳實施方式之金屬殼體成型方法 •用之第二成型模具之局部杳J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，成型模具之衝頭之剖面示意圖。 去所 圖13係本發明較佳實施方式之金屬殼體成型方 =對預成型殼體進行鍛 部剖面示意圖。 K局 圖圖14係第二次锻造成型後之預成型殼體之局部剖示 ^用之圖并^係本發明較佳實施方式之金屬殼體成型方、去r 用之精修模且斟 人土々去採 圖。 /、、預成51忒體進行精修時之局部剖面示意 金屬殼體 第一側壁 第三側壁 連接結構 側壁 【主要元件符號說明】 20 22 24 26 32 21，31 23 25 30 壁 側壁 底壁 第二 第四 預成型殼 圓角結構 16 33 1317306 第一擠壓斜面 321 第二擠壓斜面 322 第一成型模具 200 上模 210 ， 310 下模 220 ， 320 壓料板 230 · 330 衝頭 240 ， 340 第一彈性件 250 ， 350 第二彈性件 260 ， 360 模造型腔 270 ， 370 工作面 2101 側面 2301 上表面 2302 突起部 2303 抵壓面 2304 衝壓部 2401 ， 3401 台階部 2402 ， 3402 定位面 2403 ， 3403 第一側面 2404 ， 3404 第二側面 2405 ， 3405 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 17Referring to FIG. 5 to FIG. 8 , in a preferred embodiment of the present invention, the first molding die 200 includes an upper die 210 , a lower die 22 , a pressing plate 230 , a punch 240 , and a first elastic member 25 . And the second elastic member 26〇. The lower die 220 and the binder 230 are disposed on both sides of the punch 240, and the punch 240 and the lower die 220 and the binder 230 form a molding cavity 270 for receiving the sidewall 32 of the preformed casing 30, The thickness of the molding cavity 27 is greater than the thickness of the sidewall 32 of the preformed housing 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 260 are compression springs. The first elastic member 250*1317306 is used to support the lower mold 220. The second elastic member 260 is for supporting the pressure plate '230. The lower end of the upper mold 210 is a working surface 2101, which is used for forging the bottom wall 31 of the preformed casing 30, and the upper end of the lower mold 220 is a mounting surface 2201 for mounting the preformed casing 30, and pressing The plate 230 includes a side surface 2301 and a surface 2302 perpendicular to the side surface 2301. The side surface 2301 is formed with a protrusion portion 2303 adjacent to the upper end. The protrusion portion 2303 is provided with a pressing surface 2304 for pressing against the forging type. The side wall 31 of the preformed casing 30, the abutting surface 2304 and the working surface 2101 of the upper mold are perpendicular to each other, and * are parallel to the side surface 2301. The punch 240 is sequentially provided with a punching portion 2401 and a step portion 2402. The punching portion 2401 is provided with a first side surface 2404, a second side surface 2405, and a working slope 2406. 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 such that if the thickness of the side wall of the final formed metal casing 20 is T, then 0.7Τ$Ζ ^$〇.9Τ, the most ideal value is Ζ^ = 0.8Τ~0.85T. The two ends of the work bevel 2406 are respectively connected to the first side 2404 and the second side 2405, and the height of one end of the working bevel 2406 and the second side 2405 is lower than one end of the working bevel 2406 and the first side 2404, that is, work The slope 2406 is inclined toward the first side 2404, and the angle between the working slope 2406 and the first side 2404 is β!, and 45 degrees S 70 degrees, and most preferably β1 = 60 to 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 1317306 degrees, and the pressing surface of the protrusion 2303 of the pressure plate 230. 2304 is abutted against the second side 2405 of the stamping portion 2401 of the head 240, the side of the pressing plate 230, the surface 203 is abutted against the step portion 2402 of the punch 240, and the lower end of the protruding portion 2303 of the pressing 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 walls 32 of the preformed housing 30 are received in the molding cavity 270. In the first forging type, first, the upper mold 210 presses against the upper surface 2302 of the pressure plate 230 and the bottom wall 31 of the preformed casing 30, so that the lower mold 220 and the pressure plate 230 are pressed down, that is, the first Both the elastic member and the second elastic member 260 are compressed. Since the side wall 32 of the preformed casing 30 is received in the die-shaped TM cavity 270, the material of the side wall 32 of the molded casing 30 and the punch 240 are pre-processed during the process of pressing the lower die 220 and the binder plate 230. The working bevel 2406 creates 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 side of the preformed housing 30 can be The wall 32 is thickened and the fillet structure 33 at the junction of the side wall 32 of the preformed housing 30 with the bottom wall 31 will be initially sharpened and, in addition, due to the action of the working ramp 240 of the punch 240, the preformed shell A first pressing bevel 321 is formed on the end of the side wall 32 of the body 30. 12 1317306 (3) The second forging type, that is, the second molding die 300 performs the second pressing of the preformed casing to further thicken the thickness of the side wall 32' of the preformed casing 30, and A second pressing bevel 322 intersecting the first pressing bevel 321 is formed on the end of the side wall 32 of the preformed casing 30, and the rounded structure 33 is formed into a non-rounded connecting structure 26, In the embodiment, 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 The second elastic member 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 sequentially provided with a punching portion 3401 and a step portion 3402. 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 12 = 11 if the thickness of the side wall of the final formed metal casing 20 is 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 $β2$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 • 1317306 The punch 340 can form a mold together with the lower die 320 and the binder plate 330. The molding cavity 370 has a thickness greater than the thickness of the sidewall of the preformed housing 30 ′ and the molding cavity The thickness of 370 is greater than the thickness of side wall 32 of 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-squeezed. The material of the preformed housing 30 creates a flow within 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 mold 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 can be made. The side wall 32 of the 30 is thickened, and the rounded structure 33 at the junction of the side wall 32 of the preformed housing 30 and the bottom wall 31 will be formed into a non-rounded connection structure 26, and further, due to the working bevel of the punch 340 The action of 340 causes a second crush ramp 322 to be 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 322 are sharply planar. 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 • 1317306 includes an upper mold 401, a lower mold 402 and a pressure plate 4〇3. When molding, the preformed casing 3 is fixed to the lower mold 4〇2 by the pressing plate 403, and the side wall 32 of the preformed casing 30 is extended to the lower mold 4〇2, when the upper mold is 4〇1 When pressed, part of the material on the side wall 32 of the preformed casing 30 can be removed for better appearance. In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the invention is not limited to the above-described embodiments, and those skilled in the art will be equivalently modified or modified in the spirit of the invention. , should 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 for magnifying 200 times of a metal material for manufacturing a metal case for an electronic device; FIG. 3 is a perspective view of a metal case according to a preferred embodiment of the present invention. A partial cross-sectional view of the connection structure of the metal casing of the preferred embodiment of the present invention is shown. Fig. 5 is a metallographic view showing a metal material of a metal casing at a side wall of a preferred embodiment of the present invention at a magnification of 200 times. Fig. 6 is a perspective view showing a preformed casing in a metal casing forming method according to a preferred embodiment of the present invention. Fig. 7 is a schematic cross-sectional view showing a first molding die used in a method of molding a metal casing according to a preferred embodiment of the present invention. Fig. 8 is a cross-sectional view showing a punch of a first molding die for use in a metal shell molding method according to a preferred embodiment of the present invention. Fig. 9 is a partial cross-sectional view showing the first molding die used in the metal casing molding method of the preferred embodiment of the present invention for forging a preformed casing. Figure 10 is a partial cross-sectional view of the preformed casing after the first forging. Figure 0 Figure 11 is a schematic view of a metal casing forming method of the preferred embodiment. Figure 12 is a cross-sectional view showing a punch of a molding die according to a preferred embodiment of the present invention. Figure 13 is a perspective view of a metal shell of a preferred embodiment of the present invention. Figure 14 is a partial cross-sectional view of the preformed casing after the second forging type, and is a metal shell molding method for the preferred embodiment of the present invention, and a refining mold for r People are going to take pictures. Partial cross-section of the prefabricated 51 carcass for finishing the metal shell first side wall third side wall connecting structure side wall [main component symbol description] 20 22 24 26 32 21,31 23 25 30 wall side wall Second and fourth preformed shell fillet structure 16 33 1317306 First extrusion bevel 321 Second extrusion bevel 322 First molding die 200 Upper die 210, 310 Lower die 220, 320 Pressure plate 230 · 330 Punch 240, 340 First elastic member 250, 350 second elastic member 260, 360 molding cavity 270, 370 working surface 2101 side 2301 upper surface 2302 protrusion 2303 pressing surface 2304 stamping portion 2401, 3401 step portion 2402, 3402 positioning surface 2403, 3403 First side 2404, 3404 second side 2405, 3405 working bevel 2406, 3406 second forming die 300 finishing die 400 upper die 401 lower die 402 pressure plate 403 17