冲压模-笔记本电脑壳上壳模具设计

LZ91鎂合金筆記型電腦蓋板之沖壓模具設計鎂合金筆記型電腦蓋板之沖壓模具設計廖建智廖建智摘要摘要近年來，因要求輕薄短小的3C產業快速發展，鎂合金逐漸受到產業界的重視，加速了鎂合金的應用，目前用於沖壓製程之鎂板以AZ31為主，然因其原子結構屬於六方最密堆積(HCP)，在常溫的成形性甚差，必須加溫至200℃以上方具備良好之成形性。

但藉由鋰元素之添加，增加了體心立方(BCC)之原子結構，由於BCC可供滑移的系統眾多，因此鎂鋰合金之常溫成形性較佳，可採用一般塑性加工方式成形。

筆記型電腦外殼因為有兩個幾何特徵比較複雜的形狀，所以在沖壓過程中更增加其困難度。

其中一個幾何特徵複雜部分是因為底部圓角半徑太小所造成，因而使衝壓過程中產生皺褶及底部圓角破裂情形，而影響此一參數設計有壓料板之力量、胚料板之尺寸大小及壓料阻條之所在位置，然而這個破裂問題是比較容易解決，從漸進式改變衝頭圓角大小、胚料板尺寸之最佳化設計及增加壓料力方式來解決。

此外，另一個幾何特徵複雜部分是因為鉸鍊凸緣之位置太過靠近邊緣造成圓角之幾何半徑變化過於劇烈所造成，因此在沖壓過程中會產生鉸鍊凸緣部分有破裂情況，而影響此一設計參數有鉸鍊凸緣與邊緣之距離位置、母模之圓角半徑、衝頭角隅半徑、模擦係數及潤滑劑，此一問題可藉由成形過程中切割局部胚料板方式來解決，至於所切割位置則需使用有限元素分析來模擬。

本研究將進行實際開設模具來進行沖壓為以驗證有限元素之分析結果，因此共開設三組模具，板材使用鎂合金LZ91薄板，模具設計製作參數完全採用有限元素分析結果，並經實際沖壓結果證實使用有限元素分析軟體來進行鎂合金LZ91薄板沖壓之模具設計之正確性。

關鍵字：鎂合金LZ91、有限元素法、筆記型電腦外殼、鉸鍊凸緣、關鍵字沖壓模具設計。

AbstractDue to its lightweight and high specific strength, magnesium alloys have been widely used for structural components. However, because of the hexagonal closed-packed (HCP) crystal structures, magnesium alloys show low ductility at room temperature, and require thermal activation to increase their formability. It is well known that ductility of magnesium alloys can be improved with addition of lithium which develops the formation of body centered-cubic (BCC) crystal structures. The BCC crystal structure gives rise to high formability at room temperature.In the present study, the forming process was examined by the finite element simulations. According to finite element simulation analysis, two features in the notebook case were found to be relatively complex geometrically and were thus more difficult to form in the stamping forming. One of the complex features was caused by the small radius of the bottom, which would cause fracture and wrinkling during the stamping forming process. The process parameters resulting in the fracture defect were blank-holder force, blank size, and the location of draw-bead. However, this fracture defect could be easily removed by changing the punch comer radius, optimum blank size, and decreasing the blank-holder force. The other geometric complexity was caused by the dramatic change in the corner radius when the flange of hinge got too close to the edge of the notebook, which would easily cause the fracturedefect around the flange of hinge during stamping forming process. Process parameters causing this defect includes the distance between the flange of hinge and the edge of the notebook, die corner radius, punch comer radius, friction coefficient, and lubricity. This fracture defect around the flange of hinge was eliminated through local trim of blank during the stamping forming process. As for the optimum position distance of local trim blank, it was determined based on the finite element simulation results.To validate the finite element simulation results, an actual stamping process for producing notebook cases was performed. Three sets of tooling were machined to the profiles according to the finite element simulation results. The LZ91 sheets were then stamped into the shapes of notebook cases with the process parameters determined above. The experiment results have validated the finite element analysis for the process design for stamping LZ91 magnesium alloy sheets.Key Words : Magnesium Alloy AZ31、Finite Element Method、notebook case、flange of hinge、Die Design for Stamping。

分类号:单位代码:10452 毕业论文（设计）笔记本电脑上壳冲压模设计姓名学号年级专业系（院）机械工程学院指导教师2016年3月30日摘要笔记本电脑由于携带方便而广受欢迎。

轻量化是笔记本电脑的发展趋势，因此外壳制造使用镁合金材料，上壳的制造采用冲压模具。

材料确定后要查表并计算修边余量，然后确定毛坯外形及查表得出计算公式计算尺寸，然后查表得出拉深次数，其中要确定加工工艺为落料、拉深、冲孔、修边。

设计冲裁工序时要先由公式计算冲裁力，然后查表得出顶件力系数，由公式可计算出顶件力大小，再加上冲裁力和推料力就得出了压力机要提供的力，由此选择压力机型号，再由公式和查表计算出落料件尺寸和精度即可。

拉深工艺计算时先查表得出抗拉强度和系数，再由公式计算拉深力。

再查表得出计算公式并计算压边力，将二者加起来就得到了压力机应提供的总压力，由此选择压力机型号。

设计冲孔工序时，由公式计算冲孔力、推料力和卸料力，其中的系数查表可得。

关键词：镁合金；冲裁；拉深ABSTRACTThe notebook computers are widely used in recent years because it is easy to carry. The development trend of notebook computer is light weight, so the shell of computers is made by magnesium alloy material, and the manufacture of the shell use the stamping die. After the determination of the materials, look-up the table to calculate the trimming allowance, and determine the blank shape. And then according to look-up table to calculate the size, check table to attain the number of drawing, determine the processing technology for falling material, drawing, punching and trimming. When design the blanking process, it needs to finish the formula calculation of blanking force and look-up table to get the top force coefficient. By formula the force size together with the punch force and pushing force to attain the needed pressure force, then choose the type of press. By the formula and look-up table calculation to choose the blossoming materials size. During the drawing process calculation, the first step is look up the table to draw the tensile strength and coefficient, and then according the formula to calculate the drawing force. Then look at the table to calculate the formula and calculate the pressure side force, then will get the total pressure of the press should be provided, which select the type of press. In the process of punching design, according to the formula to design the punching force, pushing force and unloading force.Key words: Magnesium alloy; punching; drawing目录1绪论 (1)1.1选题背景及目的 (1)1.2国内外研究状况 (2)1.3课题研究方法 (2)1.4论文构成 (2)2冲压工艺规程的编制 (3)2.1冲压件的工艺分析 (3)2.1.1材料 (3)2.1.2结构工艺性分析 (4)2.2确定毛坯形状及尺寸 (4)2.2.1计算修边余量 (5)2.2.2确定盒形件的毛坯尺寸 (6)2.6毛坯尺寸、外形 (7)2.3排样设计及材料利用率计算 (8)2.3.1排样方式 (8)2.3.2求材料利用率的大小 (8)2.4确定工艺方案 (8)2.4.1确定基本工序 (8)2.4.2比较不同加工方案 (8)2.5工艺计算 (9)2.5.1落料工序 (9)2.5.2拉深工序 (11)2.5.3冲孔工序 (12)2.5.4修边工序 (12)2.6冲压工艺过程卡片 (13)3拉深模设计 (16)3.1模具的结构形式 (16)3.2计算模具的刃口尺寸 (16)3.2.1计算上下模刃口尺寸 (16)3.2.2计算压力中心 (17)3.3零件设计及标准件选择 (18)3.3.1凸模的设计 (18)3.3.2凹模的设计 (19)3.3.3设计定位板 (19)3.3.4弹性压边圈的设计 (19)3.3.5拉深筋的设计 (20)3.3.6设计上下模座与导柱导套 (20)3.3.7出件装置的设计 (20)3.4模具闭合高度的计算 (21)3.5装配图及零件图的绘制 (21)3.6压力机的校核 (21)4修边模设计 (22)4.1模具的结构形式 (22)4.2压力中心计算 (22)4.3零件设计和标准件的选用 (23)4.3.1斜楔和滑块的设计 (23)4.3.2滑块返回行程的复位机构 (25)4.3.3设计出件装置 (25)4.3.4设计上模座 (26)4.3.5下模座的设计 (26)4.3.6压料板的设计 (26)4.3.7防磨板的设计 (27)4.3.8设计导板 (27)4.4模具闭合高度的计算 (27)4.5装配图及零件的图绘制 (28)4.6压力机校核 (28)总结 (29)参考文献 (30)1 绪论1.1 选题背景及目的镁合金主要以镁组成，质地很轻，刚度和强度很高，超过了铝，并且对环境没有损害[1]很多常用金属在加工时都或多或少会污染环境，很多小型加工厂为了利益不惜牺牲环境，而镁合金在此方面有很大优势。

外文原文：Die design for stamping a notebook case with magnesium alloy sheetsContent SummaryIn the present study，the stamping processfor manufacturing anotebook top cover case with LZ91 magnesium–lithium alloy sheet at roomtemperature was examined using both the experimental approach and the finite element analysis. A four-operation stamping process was developed to eliminate both the fracture and wrinkle defects occurred in the stamping process of the top cover case. In order to validate the finite element analysis，an actua four-operation stamping process was conducted with the use of 0.6mm thick LZ91 sheetas the blank. A good agreement in the thickness distribution at various locations between the experimental data and the finite element results confirmed confirmed the accuracy and efficiency of the ementanalysis.The super or for mability of LZ91 sheet at room temperature was also demonstrated in the present study by successful manufacturing of the notebook topcover case. The proposed four operation process lend sit selftoan efficient approach to form the hinge in the notebook with less number of operational procedures than that required in the current practice. It also confirms that the notebook cover cases can be produced with LZ91 magnesium alloy sheet by the stamping process. It provides an alternative to the electronics industry in the application of magnesium alloys. Keywords: Notebook case；LZ91 magnesium–lithium alloy sheet；stamping；Multi-operation；Formability1. IntroductionDue to It slight weight and good performance in EMI resistance, magnesium alloy has been widely used for structural components in the electronics industry, such as cellular phones and notebook cases. Although the prevailing manufacturing process of magnesium alloy products has been die casting，the st- amping of magnesium all sheet has drawn interests from industry because of its competitive productivity and performance in the effective production of thin-walled structural components.As for stamping process，AZ31 magne siumalloy (aluminum 3%, zinc 1%) sheet has been commonly used for the for ming process at the present time,even though it needs to be formed at elevated temperature due to its hexagonal closed packed (HCP) crystal structureRecently,the magnesium–lithium(LZ)alloy has also been successfully deve- loped to improve the formability of magnesium alloy at room temperature. The ductility of magnesium alloy can be improved with the addition of lit hium that develops the formation of body centered-cubic (BCC) crystal structure (Takuda et al., 1999a,b; Drozd et al,2004).In the present study, the stamping process of a notebook top cover case with the use of LZ sheet was examined. The forming of the two hinges in the top cover of a notebook, as shown in Fig.1(a and b),is the most difficult operation in the stamping process due to the small distance between the flanges and the small corner radii at the flanges, as displayed in Fig. 1(c). This geometri complexity was caused by a dramatic change in the corner radius when the flange of get stooclo set the notebook,which would easily cause fracture defect around the flange of hinge and requirea multi-operation stamping process to overcome this problem.In the present study, the formability of LZ magnesium alloy sheets was invest- igated and an optimum multi-operation stamping process was developed to reduce the number of operation all proced using both the experiment approach and the finite element analysis.Fig.1–Flange of hinges at notebook top cover case.(a) Hinge, (b) top cover case and (c) flanges of hinge.2. Mechanical properties of magnesiumcontent of lithium increases. It is also observ from Fig. 2(a) that the curves of LZ91 sheet at room temperature and AZ31 sheet at 200,C are close to each other. LZ101 sheet at room temperature exhibit seven better ductility than LZ91 and AZ31 do at 200,C. Since the cost of lithium is very expensive, LZ91 sheet, instead of LZ101 sheet, can be considered as a suitable LZ magnesium alloy sheet to render favorable formability at room temperature. For this reason ,the present study adopted LZ91 sheet as the blank for the notebook top cover case and attempted to examine the formability of LZ91 at room temperature. In order to determine if the fracture would occur in the finite element analysis, the forming limit diagram for the 0.6mm thick LZ91 sheet was also established as shown in Fig. 2(b).alloy sheets The tensile test swereper formed for magnesium–lithiumalloy sheets of LZ61 (lithium 6%, zinc 1%), LZ91, and LZ101 at room temperature to compare their mechanical properties to those of AZ31 sheets at elevated temperatures. Fig. 2(a) shows the stress–strain relations of LZ sheets at room temperature and those of AZ31 sheets at both room temperature and 200?C. It is noted that the stress–strain curve tends to be lower.Fig. 2 – Mechanical properties of magnesium alloy.(a) The stress–strain relations of magnesium alloy; (b) forming limit diagram (FLD) of LZ91 sheet.3. The finite element modelThe tooling geometries were constructed by a CAD software, PRO/E, and were converted into the finite element mesh ,as shown in Fig. 3(a), using the software DELTAMESH. The tooling was treated as rigid bodies, and the four-node shell element was adopted to construct the mesh for blank. The material lproper ties and forming limitd iagram sobtained from the experiments were used in the finite element simulations. The other simulation parameters used in the initial run were: punch velocity of 5mm/s, blank-holder force of 3kN, and Coulomb friction coefficient of 0.1. The finite element software PAM STAMP was employed to perform the analysis, and the simulations were performed on a desktop PC.A finite element model was first constructed to examine the oneoperationforming process of the hinge. Due to symmetry, only one half of the top covercase was simulated, as showninFig.3(a).The simulation result, as show ninFig.3(b),indicates that fracture occurs at the corners of flanges, and the minimum thickness is less than 0.35mm. It implies that the fracture problem is very serious and may not be solved just by enlarging the corner radii at the flanges. The finite element simulation swere performed to study the parameters .That affect the occurrence off racture. Several approaches were proposed to avoid the fracture as well.Fig. 3 – The finite element simulations. (a) Finite element mesh and (b) fracture at the corners.4. Multi-operation stamping process designIn order to avoid the occurrence of fracture, a multi-operation stamping process is required. In the current industrial practice, itusually take satle ast tenoperational procedures to form the top cover case using the magnesium alloy sheet. In thepresent study, attempts were made to reduce the number of operational procedures. Several approaches were proposed to avoid the fracture, and the four-operation stamping process had demonstrated itself as a feasible solution to the fracture problem. To limit the length of this paper, only the two operation and the four-operation stamping processes were depicted in the following.4.1 Two-operation stamping processThe first operation in the two-operation stamp in process was side wall forming as shown in Fig.4(a),and the second one was the forming off lange ofhing epresented in Fig.4(b),the height of the flange of hinge being 5mm .Fig.4(c)shows the thickness distribution obtained from the finite element simulation. The minimum thickness of the deformed sheet was 0.41mm and the strains were all above the forming limit diagram. It means the fractured effect could be avoided. Inaddition, the height of the flange conformed to the target goal to be achieved. How- ever, this process produced a critical defect of wrinkling, as shown in Fig. 4(d), on the flange of hinge, which induces a problem in the subsequent trimming operation. Hence, even though the two-operation stamping process solved the fracture problem at the corner of the bottom and the flange of hinge, a better forming process is still expected to solve the wrinkling of flange of hinge.Fig. 4 – Two-operation stamping process.(a) Formation of sidewalls, (b) formation of hinges, (c) thickness distribution and (d) wrinkle.4.2. Four-operation stamping processThe four-operation forming process proposed in the present study starts with the forming of three side wall sand the flange of the hinge with a generous corner radius, as shown in Fig.5(a).Since the side wall close to the flange was open and the corner radius was larger than the desired ones, theflange was successfully formed without fracture. Such process success-fully avoided the difficulty of forming two geometric features simultaneously, but increased the material flow of the blank sheet. The next step was to trim the blank outside the side walls, and to calibrate the corner radius of 4mm to the desired value of 2.5mm. The hinge was thus formed, as shown in Fig. 5(b). The third step was to fold the open side, so that the sidewall could be completed around its periphery, as shown in Fig. 5(c). The effect of trimming the extra sheet outside the sidewalls in the second step on the third step was studied. When the extra sheet was not trimmed, the thickness at the corner was 0.381mm, as shown in Fig. 5(d). The thickness of Table Comparison of thickness measured ABCD Experiment 0.42mm 0.44mm 0.49mm 0.53mm Simulation 0.423mm 0.448mm 0.508mm 0.532mm Error 0.71% 1.79% 3.54% 0.38% the corner increased to 0.473mm, as shown in Fig. 5(e), if the trimming was implemented in the second step. The excessive material producedby the folding process in the third step was then trimmed off according to the parts design. The last step was the striking process that is applied to calibrate all the corner radii to the designed values. The minimum thickness at the corner of the final product was 0.42mm,and all the strains were above the forming limit diagram. It is to be noted that Fig. 5(a–c) only shows the formation of one hinge. The same design concept was then extended to the stamping process of the complete top cover case.5. Experimental validationIn order to validate the finiteel ement analysis,an actualfour operation stamping process was conducted with the use of 0.6mm thick LZ91 sheet as the blank. The blank dimension and the tooling geometries were designed according to the finite element simulation results. A sound product without fracture and wrinkle was then manufactured, as shown in Fig. 6(a). To further validate the finite element analysis quantitatively, the thickness at the corners around the hinge of the sound product, as shown in Fig. 6(b), were measured and compared with those obtained from the finite element simulations, as listed in Table 1. It is seen in Table 1 that the experimental data and the finiteelement results were consistent. The four-operation process design based on the finite element analysis was then confirmed by the experimental data.Fig. 6 – The sound product. (a) Without fracture and wrinkle and (b) locations of thickness measured.Concluding remarksThe press forming of magnesium alloy sheets was studied in the present study using the experimental approach and the finite element analysis. The formability of both AZ31 and LZ sheets was examined first. The research results in dicated th a the LZ91 sheet has favorable formability at room temperature, which is similar to that of AZ31 sheet at the forming temper- ature of 200C.The superior formability of LZ91 sheet at room tempera Ture was also demonstrated in the present study by successful manufacturing of the notebook top cover case. The proposed four-operation process lends itself to an efficient approach to form the hinge in the notebook with fewer operational procedures than that required in the current practice. It also confirms that the notebook cover cases can be produced with LZ91 magne siumalloy LZ91sheet by the stamping process. It provides an alternative to the electronics industry in the application of magnesium alloys. Acknowledg ments The authors would like to thank the National Science Council of the Republic of China for financially supporting this research under the Project No. NSC-95-2622-E-002-019-CC3, which made this research possible. They would also like to thank ESI, France for the help in running the PAM STAMP program.References[1] Chen. F.K.Huang.T.B.Chang. C.K.2003. Deep drawing of square cups with magnesium alloy AZ31sheets. Int. J. Mach. Tools[2] Manuf. 43.1553–1559.Drozd.Z..Trojanova′ .Z, Ku′ dela.S.2004. Deformation of behavior ofMg–Li–Al alloy. J. Mater. Compd. 378. 192–195.[3]Takuda.H.Yoshii.T. Hatta, N.1999a. Finite-element analysis of the formability of a based alloy AZ31sheet. J.[4] Mater. Process. Technol. 89/90. 135–140.Takuda.H. Kikuchi.S.[5]Tsukada.T.Kubota.K.Hatta.N.1999b.Effect of strain rate on deformation behavior of a Mg–8.5Li–1Zn alloy sheet at room temperature. Mater. Sci. Eng. 271, 251–256.。

1 绪论1.1 选题背景及目的金属镁及其合金是迄今在工程应用的最轻的结构材料,常规镁合金比铝合金轻30%~50%,比钢铁轻70%以上,应用在工程中可大大减轻结构件质量。

同时镁合金具有高的比强度和比刚度,尺寸稳定性高,阻尼减震性好,机械加工方便,尤其易于回收利用,具有环保特性。

20世纪80年代以来镁合金的研究得到飞速发展,随着镁合金应用面的不断扩大镁合金的研究和开发也进入了新时代。

然而镁合金的研究和发展还很不充分,很多工作还处于摸索阶段,很多有关镁合金性能的研究还没有得到完全发展。

对镁合金的成型技术的研究目前主要在金属型铸造,砂型铸造,低压铸造,差压铸造,熔模铸造,压力铸造和技压铸造等方面,对镁合金的冲压工艺研究较少。

但是,镁合金冲压方面的应用前景较好,除了可以减轻质量,外观漂亮外,特别是电磁屏蔽能力好。

本文结合省自然科学基金项目—镁合金深加工研究,主要进行变形镁合金的板材成型性分析设计。

1.2 国内外研究状况近年来,镁合金的开发和应用已经受到世界各国的重视,尤其西方发达国家十分重视变形镁合金的研究与开发,变形镁合金材料已开始向系列化发展,产品应用领域不断扩展。

其中美国的变形镁合金材料体系较为完备,合金系列有Mg-Al、Mg-Zn、Mg-RE、Mg-Li、Mg-Th等,可以加工成板、棒、型材和锻件,并且开发出了快速凝固高性能变形镁合金非晶态镁合金及镁基复合材料等。

美国与世界上最大的镁生产企业—挪威Novsk Hydro 公司签订了长期的合作关系。

日本也开始着重研究镁的新合金、新工艺、开发超强高变形镁合金材料和可冷压加工的镁合金板材。

英国开发出了Mg-Al-B挤压镁合金用于Magnox核反应堆燃料罐。

以色列最近研制出了用在航天飞行器上、兼具优良力学性能和耐蚀性能的变形镁合金[1]。

我国变形镁合金材料的研制与开发仍处于起步阶段,缺少高性能镁合金板、棒和型材,国防军工、航天航空用高性能镁合金材料仍依靠进口,民用产品尚未进行大力开发,因此,研究和开发性能优良、规格多样的变形镁合金材料显得十分重要。

提高板材成形效率的坐标网分析法J.H. Yoon, H. Huh.机械工程学院，韩国高级科学协会和技术科学镇Daejeon 305-701,南韩摘要本篇文章是采用一种新推出的方法来对提高板材的成形效率进行分析,这种方法就是坐标网分析法。

这种方法就是研究扭曲单体，即通过适当的研究规范，建立补片，包括修正后的单体。

每一片都被扩展到一个三维的表面从而获得一个连续坐标的信息。

在构造表面时，应包括每一个片，NURBS(非均匀有理B样条)表面被用来描述一个三维自由表面。

以被构造表面为基础，每一个节点一般被安排成一个非常接近正方形的单体元素。

计算状态函数是从它原始的网格系统映射到新的网格之内，从而对成形进行下一阶段的分析或更进一步的分析。

按网格方法的分析结果与没有坐标网方法直接成行的分析结果相比较来确定哪一种方法是更有效的。

© 2003 Elsevier B.V. 版权所有.关键词：坐标网；变形单体；NURBS；有限元分析1. 概述随着计算机技术和数字技术的结合和快速发展，用数字模拟进行板材成形加工达到空前的繁荣。

数字分析对复杂几何图形的板材成形和多级成形都可以做到。

对于一个复杂的几何模型来说，尽管局部严重变形将会导致计算时间的增加和数据分析的减少。

从而使分析结果更加不准确。

几何网格的扭曲和严重变形对板材成形的质量有很大影响,特别是对于多级成形。

当上一级成形的分析结果用于下一级成形分析时，几何网格的扭曲和变形对分析结果影响更大。

这种被扭曲网格的错误表象可以通过整体的或自适应重啮合技术的网格系统的重建来避免。

在模拟期间，减少单体扭曲，自适应重啮合技术被认为是一种有效的方法。

但是，它仍然需要大量的计算，并且在单体的细分中也受到限制。

要构造一个网格系统的有效方法已经被许多研究人员提上日程。

典型的方法可能是下面几种：r-方法，h-方法，p-方法。

r-方法就是在网格系统的总的自由度不变的情况下，节点被完全重排；h-方法就是在元素单体具有相同的自由度的情况下让网格的数目增加；p-方法就是通过网格系统的整体自由度的增加来提高分析的准确性。

开题报告姓名：学号：班级：一、论文题目二、文献综述金属镁及其合金是迄今在工程中应用的最轻的结构材料，其具有在体积相同时比铝合金轻36%，比锌合金轻73%，比钢轻77%的优点，在应用中减重效果较显著，像手机外壳、笔记本电脑外壳这些零件都需要这种材料，并且其加工能量仅为铝的70%。

被誉为21世纪重要的商用轻质结构材料。

镁合金研究开发的第一次热潮始于第一次世界大战前，直到20世纪60年代中期，驱动力主要是镁合金在军工和航空工业中的应用。

当时的研究方向主要是加Ag固溶强化以提高强度，加Li 一得到高韧性合金，主要针对砂型和金属型铸件，压铸镁合金主要是美国的AZ91和德国的AZ81。

从20世纪60年代后期到80年代后期是镁合金开发的第二阶段，由于汽车和飞机制造业的需要，提高镁合金的高温强度是这一时期的重点。

20世纪80年代以来镁合金的研究得到飞速发展，随着镁合金应用面的不断扩大，镁合金的研究和开发也进入了新时代。

三、选题背景及其意义四、设计任务目的与要求设计模具装配图1张，要求CAD绘图。

绘制全部零件图，并注明各个零件的材料、尺寸、公差、表面粗糙度和热处理等技术要求。

编写设计说明书一份（约1.2万字），打印成册。

设计说明书按给定形式编写和装订，字号统一为小4，字体为宋体。

设计图纸可以单独装订。

全部毕业论文件汇总袋装。

五、设计内容由于镁为密排六方结构，在室温下滑移系较少，塑性变形能力差，故在塑性加工时应采用热加工方式。

镁合金AZ31的冲压也不能在常温下进行，试验室已成功的拉深镁合金AZ31的易拉罐，壁厚为0.7mm，在加热190度时，拉深70mm；加热到250度时，拉深75mm，这是镁合金AZ31应用于冲压的一个成功的试验，通过这个试验可以反求得到一组有关镁合金AZ31冲压性能的数据。

笔记本电脑外壳属于盒形件，本次设计主要是设计拉深过程，笔记本电脑外壳应属于低盒形件拉深。

对于低盒形件，圆角部分的影响相对较小，圆角处的变形最大，所以防止起皱和拉裂是关键。

中文译文：笔记本上盖外壳的镁合金薄板冲压模具设计摘要在本研究中，在室温下分别用实验方法和有限元分析对笔记本上盖的lz91镁合金薄板冲压工艺制造情况进行检查。

四操作冲压工艺的开发消除了上盖冲压过程中的断裂和褶皱缺陷。

为了验证有限元分析，以0.6毫米厚的LZ91薄板作为毛坯，执行了一个实际的四操作冲压工艺过程。

在实验数据和有限元结果之间，恰当地符合不同单元中的厚度分布，证实了有限元分析的精确性和有效性。

本研究还通过成功地制造笔记本上盖外壳论证了室温下LZ91薄板的最优可模锻性。

本文提出的四操作过程有助于产生一种有效的方法，实现用比目前实际要求还要少的操作程序来设计笔记本铰链，也证实了笔记本外壳可以用LZ91镁合金薄板的冲压工艺来制造，提供了一个镁合金在电子工业应用中的选择方法。

关键字：笔记本外壳；LZ91镁合金薄板；多操作冲压；可模锻性1. 绪论镁合金由于具有重量轻和在电磁干扰阻力下有良好性能的优点，已被广泛用于电子行业的结构部件，如手机和笔记本电脑外壳。

虽然在主要的镁合金制造过程中产品是进行压铸的，但是由于镁合金薄板的冲压强竞争性的生产力和在有效生产薄壁结构单元时的性能，在工业领域里人们已对其产生兴趣。

在冲压过程中，尽管由于它封闭的六角晶体结构以至它的形成需要高温，AZ31镁合金（铝3％，锌1％）薄板在当前形成过程中已被广泛应用。

最近，镁锂（LZ）合金已研制成功，它可以改善室温下镁合金的可模锻性。

镁合金的韧性可以通过增加锂成分得到改善，来发展以立方体为中心的晶体结构的坯体的形成。

在本研究中，检验了LZ薄板在笔记本电脑上盖外壳的冲压过程中的应用。

笔记本上盖外壳的两个铰链的形成显示在图1的a和b中，由于边缘和边缘的小角落半径之间微小的距离，铰链的形成成了冲压过程中最困难的运行部分，这些影响在图1的c中已表示出来。

这种几何的复杂性是当铰链的边缘与笔记本的边缘太接近时，由角落半径的变化引起的，这将很容易造成铰链周围的破裂，此时需要一个多操作冲压过程来克服这个问题。

镁合金笔记本电脑外壳冲压模具设
计
随着科技的进步和普及，笔记本电脑已经逐渐成为人们日常工作、学习和娱乐的必需品。

而这些电脑外壳的材料也不断升级，从最早的塑料外壳，逐渐发展到金属外壳，再到现今的镁合金外壳。

而镁合金具有密度小、强度高、耐腐蚀性好等优点，成为了现在笔记本电脑外壳材料的主流。

然而，如何设计出适用于镁合金笔记本电脑外壳的冲压模具，成为了一个急需解决的问题。

首先，冲压模具的设计需要考虑到产品的外形、尺寸和结构，其次是材料的选择和模具的结构设计。

对于镁合金材料而言，由于其硬度较高，容易导致模具的磨损和损坏，因此需要选用足够强度的材料，并进行适当的表面处理，如硬质镀膜和高温淬火等。

此外，冲压过程中需要考虑到材料的延展性和回弹性，来保证产品的精度和外观要求。

因此，模具的结构设计需要考虑到切角、圆弧等细节，以减少冲压过程中材料的变形和损坏。

在模具的实际制造和使用过程中，还需要注意到维护和保养的问题。

由于镁合金的特性，容易受到氧化和腐蚀的影响，因此需要保持模具的清洁和干燥，以及进行涂层保护等措施，以延长模具的使用寿命。

总之，镁合金笔记本电脑外壳冲压模具的设计和制造需要充分考虑到材料、结构、制造工艺等方面的因素，以保证产品的质量和工艺要求。

同时，也需要注意到模具的维护和保养，以延长其使用寿命和降低生产成本。

随着科技的不断进步，相信镁合金材料的应用范围也会越来越广泛，对于冲压模具设计来说，更是充满了挑战和机遇。

1 绪论1.1 选题背景及目的金属镁及其合金是迄今在工程应用的最轻的结构材料，常规镁合金比铝合金轻30%~50%，比钢铁轻70%以上，应用在工程中可大大减轻结构件质量。

同时镁合金具有高的比强度和比刚度，尺寸稳定性高，阻尼减震性好，机械加工方便，尤其易于回收利用，具有环保特性。

20世纪80年代以来镁合金的研究得到飞速发展，随着镁合金应用面的不断扩大镁合金的研究和开发也进入了新时代。

然而镁合金的研究和发展还很不充分，很多工作还处于摸索阶段，很多有关镁合金性能的研究还没有得到完全发展。

对镁合金的成型技术的研究目前主要在金属型铸造，砂型铸造，低压铸造，差压铸造，熔模铸造，压力铸造和技压铸造等方面，对镁合金的冲压工艺研究较少。

但是，镁合金冲压方面的应用前景较好，除了可以减轻质量，外观漂亮外，特别是电磁屏蔽能力好。

本文结合省自然科学基金项目—镁合金深加工研究，主要进行变形镁合金的板材成型性分析设计。

1.2 国内外研究状况近年来，镁合金的开发和应用已经受到世界各国的重视，尤其西方发达国家十分重视变形镁合金的研究与开发，变形镁合金材料已开始向系列化发展，产品应用领域不断扩展。

其中美国的变形镁合金材料体系较为完备，合金系列有Mg-Al、Mg-Zn、Mg-RE、Mg-Li、Mg-Th等，可以加工成板、棒、型材和锻件，并且开发出了快速凝固高性能变形镁合金非晶态镁合金及镁基复合材料等。

美国与世界上最大的镁生产企业—挪威Novsk Hydro 公司签订了长期的合作关系。

日本也开始着重研究镁的新合金、新工艺、开发超强高变形镁合金材料和可冷压加工的镁合金板材。

英国开发出了Mg-Al-B挤压镁合金用于Magnox核反应堆燃料罐。

以色列最近研制出了用在航天飞行器上、兼具优良力学性能和耐蚀性能的变形镁合金[1]。

我国变形镁合金材料的研制与开发仍处于起步阶段，缺少高性能镁合金板、棒和型材，国防军工、航天航空用高性能镁合金材料仍依靠进口，民用产品尚未进行大力开发，因此，研究和开发性能优良、规格多样的变形镁合金材料显得十分重要。

1 绪论1。

1设计背景及目的1.1。

1背景冲压技术是一项历史悠久的生产制造技术和加工方法。

根据文献记载和考古文物的考证，我国古代的冲压加工技术处于世界前列，极大的促进了人类早期文明社会的进步.在现代社会，利用冲压模具和机械进行的冲压加工技术已有接近二百年的发展历史.英国1839年成立的Schubler公司，是早期世界上具有相当规模的、也是现今世界上最为先进的冲压公司之一.从学术上看，直至本世纪10年代，冲压加工技术的地位已经从从属于机械加工的附属技术，发展成为了一门具有完整的理论基础的应用科学。

日本有冲压工学的说法，而在俄罗斯从前苏联时期开始就有各类冲压技术学校，同时中国也有冲工艺学以及薄板成形理论等方面的教材和专著。

因而可以认为这一学科现已具备了完整的知识结构系统。

冲压技术中冲压模具在制造业中是重要基础工艺装备。

用模具生产制件所达到的高复杂程度、高精度、高生产率、高一致性和低耗材、低耗能的特性，使模具在制造业中的地位越发的重要。

国外将模具比喻为“金钥匙”、“进入富裕社会的原动力”、“金属加工帝王"等。

考古发现，早在2000多年前，我国就有了被用于制造铜器的冲压模具，证明了古代中国冲压模具和冲压成型方面的成就就已经在世界领先。

在1953年，中国的第一间冲模车间在长春第一汽车制造厂建立，该厂于1958年开始制造汽车覆盖件的模具。

我国从20世纪60年开始生产精冲模具.国内也将模具工业称为“永不衰亡的工业”、“点铁成金的行业”、“无与伦比的效益放大器".现在，衡量一个国家产品制造业水平高低的重要标志之一就是模具技术。

想要有高水平的产品必须要有高水准的模具已经成为了共识。

光说工程制造，进入80、90年代后,由于世界各国经济的高速发展和国民生活水平的大大提高，人们对汽车、家用电器等的需求也与日俱增,这些促进了冲压技术的快速发展的同时也对模具技术提出了更高的要求。

而且由于电子计算机技术的广泛应用,不仅促进了冲压技术的理论深入发展，而且使冲压机械、模具及操作的自动化程度都达到了一个更高的程度.1。