卧式单面多轴钻镗两用组合机床液压系统(DOC)

机械制造与自动化专业《液压传动》课程设计说明书班级：学号：姓名：卧式单面多轴钻镗两用组合机床液压系统1目录第一章组合机床工况分析·················21.1工作负载分析···············································································21.2惯性负载分析···············································································21.3阻力负载分析···············································································21.4工进速度选择················································································31.5运动时间·····················································································31.6运动分析······················································································31.7根据上述数据绘液压缸F-t与|v|-t图...................................................................4第二章拟定液压系统图··················42.1选择液压回路··············································································42.2组成系统·····················································································5第三章计算和选择液压元件················63.1液压缸的设计计算·········································································63.1.1初定液压缸工作压力··············································································73.1.2液压缸尺寸的计算··················································································73.1.3液压缸的流量的计算···············································································73.1.4液压缸工作腔压力的计算·········································································83.1.5液压缸的结构设计··················································································93.1.6液压缸设计需要注意的事项······································································93.1.7液压缸主要零件的材料和技术要求····························································103.2液压泵的确定与所需功率的计算····················································103.2.1液压泵的确定·······················································································113.2.2阀类元件及辅助元件的选择·····································································113.2.3油管的选择··························································································123.2.4油箱容量的确定····················································································12设计心得·························12参考文献·························12卧式单面多轴钻镗两用组合机床液压系统1一、液压传动课程设计的目的1、巩固和深化已学的理论知识，掌握液压系统设计计算的一般方法和步骤。2、锻炼机械制图，结构设计和工程运算能力。3、熟悉并会用有关国家标准、部颁标准、设计手册和产品样本等技术资料。4、提高学生使用计算机绘图软件（如AUTOCAD、PRO/E等）进行实际工程设计的能力。二、液压课程设计题目题目（一）设计一台卧式单面多轴钻镗两用组合机床液压系统，要求完成如下的动作循环：夹紧——快进——工进——死挡铁停留——快退——松开——原位停止；机床有16个主轴，钻削加工￠13.9mm的孔14个，￠8.5mm的孔2个，工件材料为铸铁，硬度HB240。动力滑台采用平导轨，工进速度要求无级调速，如用高速刚钻头进行加工，其他参数如下表所示。数参据数数据I√IIIIIIVV运动部件自重（N）9810100009990950011000快进快退速度（m/min）77.56.57.88快进行程（mm）10012011095120工进行程（mm）5060657060工进速度（mm/min）30~9030~9030~9030~9030~90静摩擦系数fg0.20.150.20.180.15动摩擦系数fd0.10.080.090.120.14启动制动时间t（s）0.20.250.210.230.3试完成以下工作：1、进行工况分析，绘制工况图。2、拟定液压系统原理图（A3）。3、计算液压系统，选择标准液压元件。4、绘制液压缸装配图（A1）。5、编写液压课程设计说明书。机床加工示意图如下：图1卧式动力滑台加工示意图《液压传动》课程设计说明书2卧式单面多轴钻镗两用组合机床液压系统第一章组合机床工况分析1.1工作负载分析工作负载即为切削阻力。1.计算切削阻力铸铁钻孔时，其轴向切削力可用以下公式计算6.08.05.25硬度DSFc式中，D—钻头直径(mm)S—每转进给量(mm/r)钻￠13.9mm的孔时，主轴转速min/3601rn，每转进给量rmms/147.01,钻￠8.5mm孔时，主轴转速min/5502rn，每转进给量rms/096.01则NSDSDFc30500240096.05.85.252240147.09.135.25145.2525.25146.08.06.08.06.08.0226.08.011硬度硬度1.2惯性负载分析NtgvGmaFi9.583602.08.9798101.3阻力负载分析摩擦负载即为导轨的摩擦阻力：静摩擦阻力NGfFgfs196298102.0动摩擦阻力NGfFdfd98198101.0《液压传动》课程设计说明书31.4工进速度选择工进速度取工进时的最大速度90mm/min1.5运动时间快进ssvLt857.0607101003111工进ssvLt3.33609050221快退svLLt29.160710)50100(312131.6运动分析设液压缸的机械效率ηcm=0.9，得出液压缸在各工作阶段的负载和推力，如表1所列。表1液压缸负载的计算工况计算公式液压缸负载F/N液压缸驱动力F/ηm/N启动fsFF1962.02180.0正向加速ifdFFF1564.91738.8快进fdFF981.01090.0工进cfdFFF31481.034978.9反向启动fsFF19622180.0反向加速ifdFFF1564.91738.8快退fdFF981.01090.0制动ifdFFF397.1441.2《液压传动》课程设计说明书41.7根据上述数据绘液压缸F-t与|v|-t图（如图1）图1F-t与|v|-t图第二章拟定液压系统图2.1选择液压回路(1)调速方式由工况得知，该液压系统功率小，滑台运动速度低，工作负载为阻力负载且工作中变化小，故可选用进油路节流调速，为防止钻通孔时负载突然消失引起运动部件的前冲现象，在回油路上加背压阀。由双联叶片泵和背压阀组成的调速系统，使动力滑台获得稳定的低速运动和较大的调速范围。(2)液压泵形式的选择系统工作循环主要由低压大流量和高压小流量两个阶段组成，最大流量与最小流量的时间之比9.3812tt。根据该情况，选叶片泵较适宜，在本方案中，选用双联叶片泵。t1t1t2t2t3t3314811962.01564.9981.011.61.5F/NV/(m/s)tt《液压传动》课程设计说明书5(3)速度换接方式因钻孔工序对位置精度及工作平稳性要求不高，可选用行程调速阀和电磁换向阀。动作可靠，转换精度较高。(4)快速回路与工进转快退控制方式的选择为使快进快退速度相等，选用差动回路作快速回路。(5)选择调压和卸荷回路在双泵供油的油源形式确定后，调压和卸荷问题都已基本解决。即滑台工进时，高压小流量泵的出口压力由油源中的溢流阀调定，无需另设调压回路。在滑台工进和停止时，低压大流量泵通过液控顺序阀卸荷，高压小流量泵在滑台停止时虽未卸荷，但功率损失较小，故可不需再设卸荷回路。(6)夹紧油路中串接减压阀，课根据工件夹紧力的需要调节并稳定其压力，即使主油路压力低于减压阀所调压力，因为有单向阀的存在，夹紧系统也能维持其压力(保压)。二位四通阀的常态位置是夹紧工件，保证了操作安全可靠。2.2组成系统《液压传动》课程设计说明书6将上面选出的液压基本回路组合在一起，并经修改和完善，就可得到完整的液压系统工作原理图，如图3所示。在图3中，为了解决滑台工进时进、回油路串通使系统压力无法建立的问题，增设了单向阀6。为了避免机床停止工作时回路中的油液流回油箱，导致空气进入系统，影响滑台运动的平稳性，图中添置了一个单向阀13。考虑到这台机床用于钻孔（通孔与不通孔）加工，对位置定位精度要求较高，图中增设了一个压力继电器14。当滑台碰上死挡块后，系统压力升高，它发出快退信号，操纵电液换向阀换向第三章计算和选择液压元件3.1液压缸的设计计算《液压传动》课程设计说明书73.1.1初定液压缸工作压力由工况分析中可知，工进阶段的负载力最大，所以，液压缸的工作压力按此负载力计算，选Pap511040,本机床为钻孔组合机床，为防止钻通时发生前冲现象，液压缸回油腔应有背压，取背压Pap52106，为使快进快退速度相等，选用212AA差动油缸，假定快进、快退的回油压力损失为PaP5107。3.1.2液压缸尺寸的计算由式cmApApF)(2211得223252115.941045.91026409.0314812cmmmppFAcm液压缸直径cmcmAD97.105.94441取