3D药芯焊丝成型机设计【药芯焊丝辊轧成型机的设计及齿轮减速箱运动仿真】【说明书+CAD+PROE】

3D药芯焊丝成型机设计【药芯焊丝辊轧成型机的设计及齿轮减速箱运动仿真】【说明书+CAD+PROE】,药芯焊丝辊轧成型机的设计及齿轮减速箱运动仿真,说明书+CAD+PROE,3D药芯焊丝成型机设计【药芯焊丝辊轧成型机的设计及齿轮减速箱运动仿真】【说明书+CAD+PROE】,焊丝,成型,设计,齿轮,减速 湘潭大学本科毕业设计说明书 目录 第一章 绪论 &1-1 任务分析与说明一，主要任务药芯焊丝辊轧成型机的设计及齿轮减速箱运动仿真二，主要内容1，药芯焊丝轧辊成型机的原理2，变速机构与成型机构的设计与仿真3，加粉装置的设计三，主要技术指标1，钢带进口速度：=12m/min(200mm/s), 2，出口速度： =15.29m/min(255mm/s)；3，钢带规格：宽厚=160.3；4，成型焊丝直径：d=4mm；焊丝截面形状:O形搭接;5，变频调速电动机型号：YVP90L-4, =1.5kw,=3.8A, =10NM, 6，工作寿命：10年，每年300个工作日，每天工作12个小时。四，预计达到的目标：1，拉丝工艺简单，生产速度高，表面质量好；2，有比较合理的价格和较低的使用成本；3，操作、使用方便，舒适性好；五，主要特色:1，拉丝工艺比轧丝工艺更简单，生产速度更高，成本更低。2，易损件拉丝模是标准件，有专业工厂可批量生产，价格大大低于轧辊。3，设备简单，使用、造价低，各主动轴由一台电动机拖动。&1-2方案分析与说明一，选题依据 我国药芯焊丝的应用和生产从上世纪90年代快速起步，近年来都以20%-30%速度快速发展，到2001年国内市场消费总量已超过1.5-1.6万吨，2002年可望达2万吨左右，虽然其在焊材总量比例还仅占1.5%左右，但其增长潜力很大。业内人士预测其在焊材中的比重3-5年内年达到3-5万吨，8-10年内达到8-10万吨，甚至更多。 药芯焊丝属于焊材中的高技术领域，它涉及成套生产装备、相关制造工艺和药芯配方等三个方面。其中成套生产装备则是重要的基础硬件。由于它的特殊性和复杂性，国内过去一直未能自行制造。因而研制开发出国产药芯焊丝成套生产设备对于发展国产药芯焊丝产业及其重要。二， 方案比较目前世界上制造焊丝的工艺有许多种，比较流行工艺方案：药芯焊丝有缝型冷轧带钢法拔模法连轧法轧拔法盘圆轧制法轧拔法无缝型钢管拔制法在线焊合法 1，连轧法连轧法是指药芯焊丝从钢带到成品焊丝的全部加工过程都在一套连轧机组上完成，工艺过程如图1。 图1 连轧工艺示意图1）连轧法工艺特点：（a）药芯焊丝成型和减径完全在同一台机组上完成，因此工艺简洁，设备紧凑，占地面积小。（b）由于越细焊丝轧制困难，若不再拉拔工艺直接轧至1.2mm以下细焊丝比较困难，所以不宜用制造1.6mm以下细结果钢用药芯焊丝，比较适合制造粗径迎面堆焊用药芯焊丝。（c）焊丝的直径偏差、椭圆度、表面光洁度及焊丝挺度较差，因而送丝性能较差。（d）由于轧辊尺寸有限，因此生产效率远不如轧拔法制造工艺高。（e）由于轧辊对材质和加工精度要求很高，本身又是易损件，因此设备、备件费用较高。（f）由于焊丝表面没有拉丝润滑剂残留物，所以其熔敷金属的扩散氢含量较低。2）连轧法结论。 由于上述原因，近年国内外已经较少适用连轧法工艺生产结构钢和不锈钢用细径焊丝，但在粗径堆焊焊丝的生产中则适用较多。2，轧拔法轧拔法是将焊丝的成型、加粉、合口工序仍放在轧丝机上完成，即可采用先轧，后拉的工艺。其工艺简图如下： 图2 轧拔法工艺简图1) 轧拔法工艺的优点：（a） 拉丝工艺比轧丝工艺简单，生产速度更快，成本更低，表面质量也更好。（b） 由于拉丝机、拉丝模、润滑剂的改进，使得拉丝速度可以达1214m/s，最快甚至可达25m/s。（c） 易损部件是标准件，有专业工厂可以批量生产，价格大大低于轧辊，所以将焊丝的减径工序大部分放在拉丝机上来完成是合理的。2）被动式轧机 生产线中的轧辊完全是被动的，轧制过程完全依靠作为动力的拉丝机来牵引。轧辊本身无动力驱动，由于被动轧辊之间转速可自协调不需要任何电气控制系统，所以比较简单。 3）集中传动式轧机 轧丝机的各垂直轧辊为主动辊，各主动辊采用电机拖动。传动系统可以采用一根长轴将动力依次分配到各机架，也可采用齿轮系统将动力分配到各机架。三，方案选取 根据实际情况，本设计采用轧拔法，采用集中式传动设计。 以达到1，工艺简单，生产速度更快，成本更低；2，传动系统可以采用一根长轴将动力依次分配到各机架，并采用齿轮系统将动力分配到各机架。3，降低设备成本，管理方便。第二章 传动设计 &2-1 电机选择根据技术要求，选择电机为YVP90L-4，技术参数如下： =3.8A =1500r/min &2-2 传动方案分析因为从电机输出的功率有两个方向，一个方向由电机经过主轴传递到加粉装置，还有一个方向传递到轧辊，并且两个方向相互垂直。所以需要锥齿轮来进行垂直方向的功率传递，即经过轴将功率传递到加粉装置；另外一个方向由斜齿轮将功率传递到轧辊。通过技术要求可以算出，在出口处，转速n=600/9 r/min； 在电机处转速n=600 r/min。可以算出总的传动比i=9。因为需要将功率传递到成型机构，所以变速箱里有2对齿轮只起传递作用，而不起变速作用。因此可以采用，锥齿轮处传动比i=3，第一对斜齿轮传动比i=3，其余斜齿轮的传动均为1。 &2-3 锥齿轮设计 齿轮精度：机器为一般机器，速度不高，故选用8级精度（GB 10095-88）材质：小齿轮40（调质），硬度280HBS；大齿轮45钢（调质），硬度240HBS。参数： 小齿轮=18 大齿轮=54 =20 模数m=3mm i=3 2-3-1按齿面接触强度设计（1） 确定公式内各数字 1）试选载荷系数 =1.6 2）计算小齿轮传递的扭矩。 3）由机械设计表10-7选取齿宽系数=1， 4）由表查得材料的弹性影响系数 =189 5）由表查得小齿轮接触疲劳强度分别为，大齿轮的接触疲劳强度为 6） 计算应力循环次数 =4.32 = 7) 取接触疲劳寿命系数， 8) 计算接触疲劳许用应力 取失效率为1%，安全系数为1，由公式得 （2）计算 1）试算小齿轮分度圆直径，代入中较小的值。 2）计算圆周速度v. 3) 计算齿宽b。 4) 计算齿宽与齿高之比 模数 齿高 5) 计算载荷系数 根据v=1.41m/s， 8级精度，由图可以查得动载系数 锥齿轮 由表可查使用系数 动载系数 6) 按实际的载荷系数校正所算得的分度圆直径， 7）计算模数 m 2-3-2按齿根弯曲强度设计 （1）确定公式中的各个计算数值 1）由图可查得小齿轮的弯曲疲劳强度极限，大齿轮的弯曲疲劳强度极限 2）由图查得弯曲疲劳寿命系数 ， 3）计算弯曲疲劳许用应力 取弯曲疲劳安全系数S=1.4，由公式得 4）计算动载荷系数K 5）查取齿形系数与应力校正系数。 锥齿轮的当量齿数 由当量齿数可查得： 6）计算大、小齿轮的并加以比较。 大齿轮的数值大，取大的数值。（2）设计计算 由于齿面模数m的大小主要取决于弯曲强度所决定的承载能力，而齿面接触疲劳强度所决定的承载能力，仅与齿轮直径有关。因此可以取由弯曲强度所算的模数2.8并就近圆整为3为标准值。 因此，齿轮模数 m=3 2-3-3几何尺寸计算（1） 计算分度圆直径 （2） 计算平均分度圆直径 mm &2-4 斜齿轮设计齿轮精度：机器为一般机器，速度不高，故选用8级精度（GB 10095-88）材质：小齿轮40（调质），硬度280HBS；大齿轮45钢（调质），硬度240HBS。 由表查得小齿轮接触疲劳强度分别为，大齿轮的接触疲劳强度为参数：小齿轮齿数，初选螺旋角，由电机输出的扭矩2-4-1按齿面接触强度设计 由公式可知： （1）确定公式内的各个数值 1）试选。 2）由图所给定的区域，可以查到， 3) 由图查 ，。则 4）许用接触应力 应力循环次数： =1.44 接触疲劳寿命系数： 材料的许用应力： 取S=1 因为，所以 （2）计算 1） 试算小齿轮分度圆直径，由计算公式得 2）计算圆周速度。 3)计算齿宽b及模数。 4）计算纵向重合度。 5）计算载荷系数K。 根据实际情况取, , , 6)按实际的载荷系数校正所算得的分度圆直径，由公式得 7）计算模数。 2-4-2按齿根弯曲强度设计。（1） 确定计算参数 1） 计算载荷系数K。 2) 由=1.55知，螺旋角影响系数.3) 计算当量齿数。 4）查取齿形系数。 查得 5）查取应力校正系数。 查得 6）计算弯曲许用应力由图可查得小齿轮的弯曲疲劳强度极限，大齿轮的弯曲疲劳强度极限 取弯曲疲劳寿命系数 取弯曲疲劳安全系数 S=1.4，由公式得 7）计算大、小齿轮并加以比较。 大齿轮的数值大。（2） 设计计算根据齿轮的实际情况，模数主要由齿根弯曲强度决定。因此可取齿轮模数为2.2-4-3几何尺寸计算 （1） 第三章 变速箱机械设计与3D建模本设计使用Pro-E软件来进行建立3D模型，并就行仿真。进行仿真不仅可以就行动态分析，并且可以更加直观的感受设计是否合理。同时又因为制造商面临全球的激烈竞争，消费者的苛求，设计产品的日趋复杂，不得不大大缩短的产品开发周期，利润压力以及很多其它方面因素的挑战。 这些挑战给制造商在产品设计生命过程中造成巨大的压力，它促使制造商寻求途径加速产品设计，降低设计费用并同时提高产品质量与创新。传统的设计流程严重的阻碍了企业对设计流程做出重大改进。通常，设计人员设计好产品之后才把问题扔给分析专家来进行分析。但是当这些分析进行完毕之后，对于产品性能提升与创新都已经太晚了。 这样的流程造成设计创新困难且费用昂贵。 因此前期的3D建模和仿真分析在现代设计显得越来越重要，并且逐渐成为设计的主流。进行仿真可以获得非常好的结果：更早更好的决策，缩短产品推向市场的时间，降低设计，更快更有竞争力的创新。 在本设计中，将3D建模过程和仿真分析过程呈现出来，以便交流和分析。变速箱的主要模块包括箱体，轴系零件，其他附件。 &3-1 箱体设计与建模1，尺寸选择。 1），取最大宽度。要装3个斜齿轮，每个齿轮的齿轮。 从机械设计手册上查取，壁厚取12mm 齿轮与机壁的间隙 b=812mm,取 b=10mm 故，箱体总宽度为L=3a+2b+212+215=392mm 2），取最大高度。 要装两个斜齿轮，加上底座与间隙。 齿轮中心距： a=106mm 底座壁厚： 12mm 润滑油的高度： l=50mm 因此，总高度H=289mm3），取最大厚度。 壁厚： b=12mm 齿宽: B=30mm试算总厚度： B=165mm 因此箱体外观 LBH=392165289 mm2，ProE建模。1）拉伸底板此时，底板为39216512 （mm）2）拉伸箱壁以拉伸平面为绘制平面，就行草绘，再拉伸。3）拉伸孔特征。 在拉伸平面上进行草绘，5个圆，半径r=47mm。再拉伸至“选定的项”，选定需要拉伸至的平面即可，去除材料。即可生成如图示的特征。4）再次拉伸其他的圆。5）箱体最后的3D模型。&3-2 轴系设计与建模在本设计中，轴系零件，包括轴，斜齿轮，键，套筒，轴承。（一），轴建模。1，尺寸确定。因为有齿轮，轴承，套筒，键等零件，因此设计此齿轮阶梯较多。轴的基本直径： =25mm =28mm与联轴器连接的直径： =20mm定位轴肩的高度： 轴环宽度： 因此，轴肩高度 =2.5mm =3mm 轴环宽度 d=5mm 轴的平面示意图2，轴的3D模型。将以上绘制的草绘图像，就行旋转360即可。（二），键槽与键建模。1，尺寸确定。在机械设计课程设计指导书上查阅到：轴键键槽公称直径d公称尺寸bh轴t毂22308743.3 因为本设计采用轴直径为25，故取bh=87, 长度L=182，键槽在轴上建模。 首先以TOP平面建立基准平面 绘制草绘图形。 拉伸，去除材料，对称拉伸。3，键的3D模型。（三），齿轮的3维建模。 在斜齿轮有5个大齿轮，1个小齿轮。取大齿轮的模型作为代表进行建模。 1，参数确定。 法面模数 mm 齿数z=51 螺旋角 齿宽 B=30mm 轴径D=28mm 键槽t=3.3mm 2，斜齿轮建模。 1）输入参数。2）输入关系。3）绘制齿形。4）特征复制、平移。5）扫描混合。6）阵列。7）齿轮模型。3，小齿轮建模。 小齿轮的建模与大齿轮建模过程类似，只有齿数不一样，因此不再赘述。（四），套筒建模1，尺寸确定。 套筒直径d=25mm， 长度为12mm。2, 3D模型。 套筒建模简单，只要一个拉伸特征即可。（五） 轴承建模。1，轴承选用。本设计中采用了，斜齿轮传动，斜齿轮具有很多优点：1） 啮合性能好，传动平稳、噪音小。2） 重合度小，降低了每对齿轮的载荷，提高了齿轮的承载能力3） 不产生根切的齿数少。但是也使得运转时产生轴向推力。因此，本设计中，不能采用深沟球轴承。本设计采用角接触轴承。下表是角接触球轴承的资料。角接触球轴承结构代号基本额定动载荷比极限转速比轴向承载能力性能和特点70000C（=15）1.01.4高一般可以承受径向载荷及轴向载荷，也可以单独承受轴向载荷。要成对使用。70000AC（=25）1.01.3较大70000B（=40）1.01.2更大 本设计中，轴的直径为25mm，因此采用轴径为25mm的轴承。国标代号为7205AC。 2，轴承参数。 本设计采用的轴承代号为7205，角接触球轴承。 小径d=25mm 大径D=52mm 轴承宽度B=15mm 3，轴承3D模型。&3-3 装配建模3-3-1轴系装配建模在轴上需要装配齿轮、键、套筒、轴承等零件，在之前所有的零件均已完成3D建模，现在只需要对其装配即可。其装配过程如下：1，进入“组件”环境。2，加入“轴”。 3，与键进行装配。 4，与斜齿轮进行装配。 5，与套筒装配。6，与轴承装配。 角接触球轴承需要成对使用，因此在轴两端都需要装配轴承。 轴承代号为7205，满足轴的工作需求。此时，装有斜齿轮的轴，已经装配完毕。但是还需要将此轴系装配至箱体上。3-3-2变速箱整体装配轴系装配完成后，就将已经装配完成的轴系与箱体就行装配，就可以完成整个变速箱的装配过程。注：为了显示变速箱的内部结构，特意将箱盖隐藏，即不显示。&3-4变速箱仿真 通过新建伺服电机，并且设定速度为36/s 经过10 s 时间，就可以看到一整圈的过程。 整个变速箱的仿真过程可以在电脑上展示，在此不在赘述。第四章 加粉装置机械设计与3D建模加粉装置是将药粉输送到轧成U型槽的钢带里的装置。其机械机构主要由规则的块状机构构成，因而其零件建模与装配均比较简单。因此，下文将直接给出主要零件的建模结果和装配结果。 &4-1 加粉装置设计与建模主要零件的建模结果&4-2加粉装置装配过程4-2-1机械底板的装配模型4-2-2带轮部分建模结果4-2-3整体装配建模结果 &4-3加粉装置仿真加粉装置采用带传动，由卷筒带动皮带。再由皮带将药粉加至U型钢槽中。仿真部分，由电脑演示，此处不再赘述。第五章 零件校核 &5-1 轴校核在第一级变速箱上，传递的功率最大。因此校核，第一级变速箱上的装有锥齿轮的轴。1，轴的尺寸。轴的直径d=25mm 装有齿轮的部分直径D=45mm总长L=389mm 轴上的尺寸2，锥齿轮参数。 模数 m=2 mm 小齿轮齿数 =18 大齿轮齿数 =54 啮合角=20 =18.43 =71.57 传动比 i=33，其他参数。 锥齿轮传递效率 =0.40.97 （8级，油润滑） 取=0.95 球轴承传递效率 =0.99（一对） 转速n=10=600 电机额定参数 =1.5kw =3.8A =104，轴上的功率P，转速n和转矩T P=1.50.950.99=1.42kw n=n1=600 T=95500005，求作用在齿轮上的力 由齿轮计算公式知，分度圆直径 d=mz=318=54mm=420.02tan20cos18.43=145.03N =420.02tan20sin18.43=48.3813N6，初步确定轴的最小直径。 根据公式确定轴的最小直径。选取轴的材料为45钢，调质处理。根据可查阅资料，取=112，于是得 所选的直径d=25要大于最小直径，初步符合设计要求。7，求轴上的载荷。 在水平面内，72=389 于是得 =77.74N 根据在水平方向，力平衡原理： =420.0277.74=342.27N 水平面内最大弯矩： =72=24643.44 在垂直面内，轴向力平衡得 =48.38= 轴端弯矩平衡， = 垂直方向，力平衡， = 弯矩， =72118.18=8507.54 = -28317= -8876 =26070.21 =26193.1768 载荷水平面H垂直面V支反力F=77.74N =342.27N=118.18N =26.84N弯矩M=24643.44 =8507.54 = -8876 总弯矩=26070.21 =26193.1768 扭矩T8，按弯扭合成应力校核轴的强度 进行校核时，通常只校核轴上承受最大弯矩和扭矩的截面（即危险截面C）的强度。根据公式和上表的数据，以及轴的单向旋转，扭转切应力为脉动应力，取=0.6，轴的计算应力 其中W为抗弯截面系数，截面为圆面，故 W=0.1进而， 前已选定轴的材料为45钢，调质处理，查得=60MPa。因此，故安全。9，精确校核轴的疲劳强度 （1）判断危险截面 键槽，轴肩及过渡配合所引起的应力集中均将削弱轴的 疲劳强度，但是轴的最小直径是按扭转强度较宽裕确定的，这些主要受扭矩的 截面均无需校核。 从应力集中对轴的疲劳强度的影响来看，轴肩处的应力集中最严重；从受载的情况来看，齿轮中心截面上的应力最大；但是安装齿轮处的轴径较大，因此不需校核，因而该轴只要校核轴肩处的疲劳强度即可。（2）截面左侧 抗弯截面系数 W=0.1d3=0.1253=1562.5mm3 抗扭截面系数 =0.2d3=0.2253=3105mm3 弯矩 M=26193（20-10）/20=13096.5 截面上的弯曲应力 b=M/W=13096.5/1562.5=8.38 MPa 截面的扭转切应力 T=T/=/3105MP=7.3MPa 轴的材料为 45钢，经调质处理，由表15-1，查得B=640MPa，-1=275MPa, -1=155MPa 截面上由于轴肩而形成的理论应力集中系数按表3-2查取，由r/d=1.6/25=0.064,D/d=30/25=1.2,查得=1.89，=1.5 又由附图3-1得轴的材料的敏性系数q=0.82,q=0.85则有效应力集中系数为k=1+q(-1)=1+0.82*0.89=1.7298 k=1+ q(-1)1+0.85*0.5=1.425由附图3-2得尺寸系数=0.9,由附图3-3得扭转尺寸系数=0.92 轴按磨削加工,由俯图3-4得表面质量系数为 =0.92 轴未经表面强化处理,即=1,则得综合系数为 K = k/+1/=1.7298/0.9+1/0.92-1=2 K= k/+1/=1.425/0.92+1/0.92-1=1.64 又由机械设计手册.中册.第二版P772得碳钢的特性系数 =0.10.2，取=0.1 =0.050.1，取=0.05计算安全系数S值得 S= =14.3 S=2.75 Sca=2.7S=1.5,故按此方案设计的轴是安全的。（3）右侧截面 抗弯截面系数 W=0.1d3=0.1253=1562.5mm3 抗扭截面系数 =0.2d3=0.2253=3105mm3 弯矩 M=26193（20-10）/20=13096.5 截面上的弯曲应力 b=M/W=13096.5/1562.5=8.38 MPa 截面的扭转切应力 T=T/=/3105MP=7.3MPa 轴的材料为 45钢，经调质处理，由表15-1，查得B=640MPa，-1=275MPa, -1=155MPa 截面上由于轴肩而形成的理论应力集中系数按表3-2查取，由r/d=1.6/25=0.064,D/d=30/25=1.2,查得=1.89，=1.5 又由附图3-1得轴的材料的敏性系数q=0.82,q=0.85则有效应力集中系数为k=1+q(-1)=1+0.82*0.89=1.7298 k=1+ q(-1)1+0.85*0.5=1.425由附图3-2得尺寸系数=0.9,由附图3-3得扭转尺寸系数=0.92 轴按磨削加工,由俯图3-4得表面质量系数为 =0.92 轴未经表面强化处理,即=1,则得综合系数为 K = k/+1/=1.7298/0.9+1/0.92-1=2 K= k/+1/=1.425/0.92+1/0.92-1=1.64 又由机械设计手册.中册.第二版P772得碳钢的特性系数 =0.10.2，取=0.1 =0.050.1，取=0.05计算安全系数S值得 S= =14.3 S=2.75 Sca=2.7S=1.5,故按此方案设计的轴是安全的，故该轴在截面右侧也是足够的。10，结论根据上述计算，可证明本设计满足轴工作时的安全要求。此轴因无大的瞬时过载及严重的 盈利循环不对称，所以静强度校核可以略去，此轴的设计计算完成。11，附录提高轴的强度的常用措施 1）合理布置轴上零件以减小轴的载荷为了减小轴所承受的弯矩，传动件应该尽量靠近轴承，并尽可能不采用悬臂的支撑形式，力求缩短支承跨距及悬臂长度等。当转矩由一个传动件输入，而由几个传动件输出时，为了减小轴上的扭矩，应将输入件放在中间，而不要置于一端。 2）改进轴上零件的结构以减小轴的载荷 3）改进轴的结构以减小应力集中的影响轴通常是在变应力条件下工作的，轴的截面尺寸发生突变处要产生应力集中，轴的疲劳破坏往往在此处发生。为了提高轴的疲劳强度，应尽量较少应力集中源和降低应力集中的程度。为此，轴肩处应采用较大的过度圆角半径r来降低应力。但对定位轴肩，还必须保证零件得到可靠定位。当靠轴肩定位的零件的圆角半径很小时，为了增大轴肩处的圆角半径，可采用内凹圆角或加装隔离环。4）改进轴的表面质量以提高轴的疲劳强度 轴的表面粗糙度和表面强化处理方法也会对轴的疲劳强度产生影响。轴的表面越粗糙，疲劳强度也越低。因此，应合理减小轴的表面及圆角处的加工粗糙值。当采用对应力集中甚为敏感的高强度材料制作轴时，表面质量尤为予以注意。 表面强化处理的方法有：表面高频淬火等热处理；表面渗碳、氰化、氮化等化学处理；碾压、喷丸等强化处理。 &5-2 轴承校核本设计采用的是角接触球轴承，代号为7205AC。滚动轴承是现代及其中广泛应用的部件之一，它是依靠主要元件间的滚动接触来支撑转动零件的。滚动轴承绝大多数已经标准化，并由专业工厂大量制造及供应各种常用规格的轴承。滚动轴承具有磨擦阻力小，功率消耗少，起动容易等优点。1，轴上的受力情况 1）轴上参数 轴上功率 P=1.50.910.91=1.242kw 轴的转速 n=N/i=600/9=66.67轴的力矩 T=9550000=95500001.242/66.67=17791.65 2）斜齿轮受力情况 斜齿轮参数 =2mm z=51 分度圆直径 d=106mm N = = 2，轴承受力情况 1）左侧轴承受力情况 =96.19N 77=127.3936 得=59.5589N 2）右侧轴承受力情况 =96.19N =127.3959.89=68.33N 可以看出，右侧轴承的受力较大，因此校核右侧轴承，如果右侧轴承可以达到寿命要求，则左侧必定会达到使用寿命要求。 3,轴承的当量载荷 P=（X+Y） X、Y分别为径向动载荷系数和轴向动载荷系数 e=/=1.4 查取资料知， X=0.41 Y=0.87 根据表：载荷性质举例中等冲击1.21.8动力机械、冶金机械、卷扬机、机床等 取 =1.2 于是得：P=（0.4168.33+0.8796.19）1.2=140.4 4，轴承的使用寿命 = 为指数。对于球轴承，=3；对于滚子轴承，=。因为在本设计中，轴的运转速度较低，温度不高。因此温度对轴承的影响，可以不考虑，即取=1。在本设计中，预期工作寿命为10年，300个工作日，一天12个小时。可以算得：=1030012=36000 h计算得出基本额定载荷C C=735.91N查表得知，7205AC的基本额定负荷： =15.8KN =9.88KN因为计算出的基本额定载荷远远小于轴承所拥有的基本额定载荷，因此在本设计中，轴承的选用负荷设计要求。参考文献1 濮良贵 纪名刚，机械设计。北京：高等教育出版社，2006.52 张云静等，Pro/ENGINEER野火5.0从入门到精通。北京：电子工业出版社，2010.63 刘继元 陈邦固 王秀文 吴爱国，年产1500t药芯焊丝生产线的研制。焊接，2000（2）4 詹友刚，Pro/ENGINEER2001教程。北京：清华大学出版社，2003.45 孙桓 陈作模 葛文杰，机械原理。北京：高等教育出版社，2006.533 Journal of Mechanical Science and Technology 22 (2008) 15371543 DOI 10.1007/s12206-008-0430-9 Journal of Mechanical Science and Technology Optimum design of roll forming process of slide rail using design of experiments Minjin Oh and Naksoo Kim * Department of Mechanical Engineering, Sogang University, Seoul, 121-742, Korea (Manuscript Received December 6, 2007; Revised April 4, 2008; Accepted April 26, 2008) - Abstract In the design of the roll forming process, design errors can be determined in advance by using an FE simulation tool such as SHAPE-RF. In the case of a product such as a slide rail having a complicated shape and requiring high- precision forming, a standard is necessary for quantitatively evaluating the quality of the formed shape. In the analysis of the roll forming process of a slide rail, the pass having the largest deformation is designated as the target pass and the positions and shapes of the rolls are set as design variables. A minimum number of simulations was performed by us- ing the table of orthogonal arrays. A cost function was obtained from the results by using the design of experiments such as the response surface method and it was minimized for satisfying the design constraints. By improving the de- sign of the target pass, the shape of the final product approaches that intended by the designer. Keywords: Design of experiments; Finite element method; Roll forming process; Shape difference factor - 1. Introduction Roll forming is a process that progressively bends a flat strip of sheet metal through pairs of forming rolls, and it can be used for inexpensively manufacturing long sheet metal products with a constant cross sec- tion. Since roll forming requires manpower only for loading the strip and unloading the product, the man- power required can be reduced. If the shape of the product is simple, it takes little time to change the die and to set up a process. Since the length of the prod- uct can be controlled easily, roll forming can also be used for the batch production of small quantities of a product. Since the roll forming process was designed based on the designers experience for developing a new product or improving the quality of existing products, the design defects were confirmed after the production of the prototype; therefore, the compatibil- ity of the corrected design could be verified after the production of the prototype. This process leads to an increase in the production cost, which reduces the competitiveness of manufacturers. In order to solve this problem, an FE simulation of the roll forming process is used prior to the production of a prototype in order to predict design defects and reduce the cost of design correction. Bhattacharayya et al. 1 performed a semi- empirical approach and by minimizing the total en- ergy produced an expression for predicting deforma- tion length of a channel section. Duggal et al. 2 compared the FE simulation results with Bhat- tacharayyas experimental results. And other numeri- cal 3-6 and experimental 7, 8 studies have been performed. Hong and Kim 9 developed a 3D FEM program for the roll forming process and predicted the scratch defect of the roll forming process with the rigid- plastic finite element method. The analysis using the rigid-plastic finite element method has also been ex- tended to predict the edge shape 10 and roll wear 11. Kim et al. 12 made the prediction of buckling * Corresponding author. Tel.: +82 2 705 8635, Fax.: +82 2 712 0799 E-mail address: nskimsogang.ac.kr KSME n d , the number of design variables; and i , the unknown coefficients. Eq. (2) is used to calculate the coefficients of RSM that minimize the square summation of the residuals using least square method. T1T () = XX XY (2) where X denotes the design matrix comprising experimental points and Y denotes the response vector. 2.2 Shape difference factor If products that are manufactured through the roll forming process do not meet the standards because of a design error, it is necessary to correct the design defects, as shown in Fig. 1. A slide rail having a complicated shape and requir- ing high precision in forming and straightness is manufactured by using the roll forming process 20. It is difficult to determine the compatibility of the design since the product has a complicated shape. A standard is necessary to quantitatively evaluate the quality of the formed shape; one such standard is called the shape difference factor (SDF). In order to quantitatively evaluate the precision of the shape of a Fig. 1. Flow chart for the correction of the roll forming proc- ess design. M. Oh and N. Kim / Journal of Mechanical Science and Technology 22 (2008) 15371543 1539 Fig. 2. Comparison of the raw plan and the simulation result. Fig. 3. Measurement of the difference between the raw plan and the simulation result. product manufactured by the roll forming process, the cross section of a simulation or experimental result is set on the center of the cross section of a raw plan with grids drawn on it, as shown in Fig. 2. As shown in Fig. 3, SDF is decided by the summation of the difference in the distance that is measured between the raw plan and the simulation or experimental result along the direction of thickness and it is defined as given by Eq. (3). 2 0 1 SDF ( / ) = = n i i dt (3) where d i denotes the difference in distance between the result and the raw plan at the i th elements and t 0 denotes the thickness of the initial strip. Since the shape of the cross section of the product is symmetric, the SDF is measured at the right cross section of the product. 3. Simulation and experimental results 3.1 Process condition A slide rail is comprised of an inner member, mid- dle member, outer member, and bearing balls. Since this research focuses on the slide rail, the middle member is analyzed because an inner rail and an outer rail are formed at the middle member. The middle member is manufactured with a 25-pass line. The distance between the passes is 350 mm; odd- numbered passes are set up as driving rolls, and even- numbered passes are set up as idle rolls, and the ve- locities of each pass roll are set up to produce a prod- uct with a constant velocity of 40m/min. The thickness and width of the initial strip is 2 mm and 60 mm, respectively; the strip is made of SCP10, whose material properties are listed in Table 1. The final shape of the cross section of the product manu- factured in the experiment is shown in Fig. 4. Table 1. Material properties of SCP10 Youngs modulus (GPa) 210 Poissons ratio 0.3 Yield Strength (MPa) 433 UTS (MPa) 460 Fig. 4. Cross section obtained from the experiment. 3.2 FE simulation software FE simulations are performed by the roll forming simulation program SHAPE-RF v4.0.0 based on the rigid-plastic finite element method. This program uses the normalized plane strain condition as the ini- tial boundary condition for initially determining the free surface. The velocity field is calculated by the FEA of the 3D kinematic steady state and the final shape is determined by an iterative method that cali- brates the boundary conditions and the free surface. Information such as the strain rate and pressure torque 1540 M. Oh and N. Kim / Journal of Mechanical Science and Technology 22 (2008) 15371543 Table 2. Process conditions of FE simulation. Flow stress (MPa) 0.024 502(0.002 )=+ f Initial thickness (mm) 2.0 Strip width (mm) 60.0 Friction coefficient 0.1 No. of PASS 25 Section 80 No. of elements Rolling direction 20 Fig. 5. Flower pattern of the slide rails middle member. Fig. 6. FE simulation result. is obtained based on the velocity field. The reliability of SHAPE-RF has been verified by several previous papers 9-13. The process conditions of the FE simulation are listed in Table 2. Swifts flow stress equation is used to express the stress-strain relation of a strip, and it is defined as given by Eq. (4). 0 () n f K =+ (4) where f denotes the flow stress; K, the strength coefficient; , the effective strain; 0 , the initial effective strain; and n, the strain hardening coefficient. The flow stress of the strip is obtained by using the “convert” function of SHAPE-RF and it is shown in Table 2. The flower pattern of the middle member is obtained by using the FE simulation program and it is shown in Fig. 5. The final shape of the cross section of the roll forming product is shown in Fig. 6. 3.3 Verification of FE simulation software The SDF obtained from the experimental and simu- Fig. 7. Longitudinal strain along the rolling direction. lation results is 0.87450 and 0.91677, respectively. The difference between the results and the raw plan mostly occurs at areas where the slide rail is bent. The relative error is 4.83%. The FE simulation cannot perfectly approximate the real process because obscure parameters exist at the site of the manufacturing process. For example, for any model of friction that expresses the contact between objects to be valid, it must explain the fric- tional behavior of two bodies under different loads, speed of relative sliding, temperature, surface condi- tions, environment, etc., as observed in practice. Con- sequently, many models have been proposed with varying degrees of success 21. Although many un- certain parameters exist, as mentioned above, the FE simulation is verified since the shape difference error between the FE simulation and experimental results that is evaluated at the final section increases to 4.83% as compared to the incipient shape. 4. Procedure for design correction and discussion 4.1 Designation of target pass For design variables to be applied to the design of experiments, they should be restricted because many process variables are found in the roll forming proc- ess. In the FE simulation of the roll forming process of the slide rail, the pass where the largest deforma- tion occurs is designated as the target pass for the design variables. The longitudinal strain along the rolling direction is shown in Fig. 7 and the largest deformation occurs at the 6.3 m spot along the rolling direction. Therefore, the 18 th pass is designated as the target pass. M. Oh and N. Kim / Journal of Mechanical Science and Technology 22 (2008) 15371543 1541 Table 3. Levels of the design variables (unit : mm). Design Variables Level 0 Level 1 Level 2 A 17.7 18.7 19.7 B 12.5603 13.5603 14.5603 C 5 5.4 5.8 4.2 Table of orthogonal arrays The strip is bent by the left and right rolls at the 18 th pass. Since the slide rail has a symmetric shape, the design variables are limited to the right roll. De- sign variable A is the x-coordinate of the flat part of the right roll and B is the y-coordinate of the same part. C is the curvature of the right roll. The design variables and levels are listed in Table 3 and a table of orthogonal arrays L 9 (3 4 ) is used. Table 4 shows the table of orthogonal arrays for the SDF obtained from the FE simulation results. 4.3Optimization of the cost function Based on the table of orthogonal arrays, the cost function obtained by RSM is given by Eq. (5) as: 12 3 13.90852-0.93098 +2.62837 -7.13367 +0.05303 -0.03022 1.08379 -0.08205 -0.37625 xx xxx + x xx xx = 22 12 2 31223 (5) where 1 x denotes the design variable A; 2 x , the design variable B; and 3 x , the design variable C. In order to examine the adequacy of the cost func- tion, Fig. 8 shows the comparison of the values be- tween the cost function in which the conditions of Table 4 are applied and the SDF obtained from the FE simulation results. In order to investigate how the numerical differences in the compared values exist, it is verified through Eq. (6) that the error is less than 1%. Therefore, the cost function can represent the SDF between the final shape of the product and the raw plan when the 18 th pass is corrected. ca c - Error(%) = 100 (6) where c denotes the SDF computed from each simu- lation and a denotes the value of the cost function when the same variables are inputted. Table 4. Table of orthogonal arrays for the SDF. No. A B C SDF of the simulation 1 0 0 0 1.38007 2 0 1 1 1.07844 3 0 2 2 0.88306 4 1 0 2 1.22510 5 1 1 0 1.35087 6 1 2 1 0.87713 7 2 0 1 1.18833 8 2 1 2 0.91890 9 2 2 0 1.32407 Fig. 8. Comparison of c and a In order to minimize the cost function, the BFGS method, which directly updates a Hessian matrix, is used. Initial design variables and the constraints are given as follows: 123 17.0, 12.0, 5.5xxx= = (7) 1 2 3 17.7 19.7 12.5603 14.5603 5.0 5.8 x x x (8) The result of minimization is given as follows: 12 3 19.7, 14.5603, 5.71xx x= = 0.60159= Based on this result, the 18 th pass is corrected and the FE simulation is performed. There is a difference of 30.87 % between the minimum value of the cost function and the SDF of the FE simulation result of 1542 M. Oh and N. Kim / Journal of Mechanical Science and Technology 22 (2008) 15371543 Fig. 9. Comparison of the SDF between the original design and the optimum design. Fig. 10. Comparison of the raw plan and the optimized simu- lation result. 0.87023. Although the result indicates a wide gap in the minimum of the cost function, the SDF of the optimized result decreases by 5.34 % as compared to the original result of 0.91677; the comparison of the results is shown in Fig. 9. The cross section of the optimized simulation result and the raw plan are compared, as shown in Fig. 10. A significant differ- ence is observed between c and a since the cost function obtained from the restricted design variables does not consider all conditions of the target pass such as the design of the top and bottom rolls. Further, roll forming has many design variables such as roll velocities, friction condition, and angle of roll. If more process variables are contained in the design variables, then the error between the FE simulation result and the cost function will be smaller than that in the above result. 5. Conclusions In order to improve the efficiency of the roll form- ing process, it is very important to immediately cor- rect a design that has some defects. There is a product called a slide rail that has a complex shape and whose design is difficult to modify. In this paper, the roll forming design was corrected by the design of ex- periments. The SDF was also introduced to determine the compatibility of the roll design. The conclusions drawn from this study are listed below. The correction of the design of the target pass, which is designated through the measurement of the longitudinal strain along the rolling direction of the entire process, affects the final shape of the roll form- ing product. The SDF, which represents the difference between the cross section of the product that is affected by the change of the design variables and the raw plan, is suggested as a standard. Further, the cost function that can evaluate the SDF is derived by using the design of experiments such as the RSM. The optimum de- sign is determined through the minimization of the cost function. The minimum value of the cost func- tion is applied to the design of the target pass and it decreases the SDF by 5.34 %. Consequently, the cross-sectional shape of the slide rail obtained by the simulation approaches the shape intended by the de- signer. Nomenclature- i x : Design variable i d : Difference between the simulation or experimental result and the raw plan 0 t : Thickness of initial strip : Cost function f : Flow stress : Effective strain 0 : Initial effective strain c : Computed shape difference factor a : Analytical shape difference factor References 1 D. Bhattacharayya, P. D. Smith, C. H. Yee and I. F. Collins, The prediction of Deformation length in cold roll forming, J. Mech. Working Technol., 9 (1984) 181-191. 2 N. Duggal, M. A. Ahmetoglu, G. L. Kinzel and T. 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