专用铣床的设计.doc

--------------------------校验:_____________-----------------------日期:_____________专用铣床的设计目录1、设计流程图··············································22、设计依据················································23、工况分析················································3··········································3阻力负载········································5·········································54、初步确定油缸参数,绘制工矿图·····························7······························7··································8················95、确定液压系统方案和拟订液压系统原理图···················11·····························11···································12···································136、选择液压元气件·········································14···································14···················15···································16·····································177、验算液压系统性能·······································18参考文献·················································20一、设计流程图液压系统设计与整机设计是紧密联系的,设计步骤的一般流程如图明确液压系统的设计要求否否液压CAD是否符合要求?绘制工作图,编制技术文件是否通过?验标液压系统性能选择液压元件拟定液压系统原理图确定执行元件主要参数执行元件运动与负载分析是结束是下面将按照这一流程图来进行本次液压课程设计。二、设计依据:专用铣床工作台重量为3000N,工件及夹具最大重量为1000N,切削力最大达9000N,工作台的快进速度为/min,进给速度为60~1000mm/min,行程为400mm(其中快进340mm、工进60mm)。工作循环为快进→工进→快退→三、工况分析液压系统的工况分析是指对液压执行元件进行运动分析和负载分析,目的是查明每个执行元件在各自工作过程中的流量、压力、功率的变化规律,作为拟定液压系统方案,确定系统主要参数(压力和流量)的依据。负载分析外负载=9000N其中表示最大切削力。对于专用铣床铣削时铣刀所承受的主切削力大小(单位N)为:(N)式中P—单位切削力()f—每转进给量(mm/r)—背吃刀量(mm)下面将进行具体参数的计算:由公式可得(其中表示每分钟进给速度,n表示铣刀的转速)由设计依据可知n=300r/min工进速度=60—1000mm/min,故我们取=300mm/min。对于单位切削力P,由以下的常用金属材料的单位切削力表可得,我们选P=2000。类别材料牌号单位切削力P()钢易切钢Y40Mn1700结构钢452000合金结构钢40Cr不锈钢1Cr17Ni92500铸铁灰铸铁HT2001140铸造合金铸造锡青铜ZcuSn5Pb5Zn5700铸造铝合金ZALSn7Mg720对于铣削背吃刀量,我们选用硬质合金铣刀,查铣工计算手册可得,取mm。根据以上的公式可得:因为3000<=9800N,所以选取的合适阻力负载静摩擦力:F=(G1+G2)·其中F—静摩擦力NG1、G2—工作台及工件的重量N—静摩擦系数由设计依据可得:F=(G1+G2)·=(3000+10=800N动摩擦力F=(G1+G2)·其中F—动摩擦力N—动摩擦系数同理可得:F=(G1+G2)·=(3000+10400N惯性负载机床工作部件的总质量m=(G1+G2)/g=4000/kg惯性力Fm=m·N其中:a—执行元件加速度m/sut—执行元件末速度m/su0—执行元件初速度m/st—执行元件加速时间s因此,执行元件在各动作阶段中负载计算如下表所示:工况油缸负载(N)负载值(N)启动F=F800