1005-EXCITE-Timing-Drive-Basic-Training-Timing-Dri

[e-mail]基础培训教程–凸轮轴正时模型EXCITETimingDriveDynamicEXCITETimingDriveBasicTrainingTimingDriveDynamic205/18/2012Copyright©2012,AVLASTCHINA阀系结构分析流程：SingleValveTrain(SVT)凸轮型线的设计和修改运动学校核SVT动力学分析结构参数优化OK?OK?YESNOYESNO模型应用单质量或双质量模型输入总刚度、阻尼和质量等属性应用多体动力学模型输入各质点的质量、刚度、阻尼、摩擦等属性目标满足热力学性能的要求动力学性能校核边界条件产品耐久性、疲劳动力学限制（受力、速度等）、耐久性、疲劳和噪声计算时间Seconds1~2minperEngineSpeedEXCITETimingDriveBasicTrainingTimingDriveDynamic305/18/2012Copyright©2012,AVLASTCHINA阀系结构分析流程：TTD+Camshafts+SimpleTimingDriveTTD+Camshafts+SimpleTimingDrive动力学分析结构参数优化OK?YESNO模型●上一流程SVT模型●轴模型●简易皮带链条模型（纵向特性）●详细皮带链条张紧单元目标●动力学评价●校核设计变量●为EXCITEPowerUnit的NVH分析获得边界条件边界条件动力学要求（受力、运动等）计算时间全转速范围需要2～3小时EXCITETimingDriveBasicTrainingTimingDriveDynamic405/18/2012Copyright©2012,AVLASTCHINA阀系结构分析流程：TTD+Camshafts+SimpleTimingDrive详细皮带链条模型动力学分析结构参数优化OK?YESNO张紧器调整模型●上一流程SVT模型●轴模型●详细皮带链条张紧单元目标●动力学评价（包括高阶效应）●为EXCITEPowerUnit的NVH分析获得边界条件边界条件动力学要求（受力、运动等）计算时间各转速范围需要2～3小时，低转速计算时间较长EXCITETimingDriveBasicTrainingTimingDriveDynamic505/18/2012Copyright©2012,AVLASTCHINA整阀系模型58ValveStem_3_251ValveStem_3_144ValveStem_345ValveSpring_359ValveSpring_3_252ValveSpring_3_153CamContour_3_146CamContour_360CamContour_3_247FingerFollowerCS61FingerFollower_2CS54FingerFollower_1CS55ValveFace_3_162ValveFace_3_248ValveFace_363ConnectionShaftValveTrain_256ConnectionShaftValveTrain_149ConnectionShaftValveTrain57RigidGround_150RigidGround64RigidGround_237CamContour_230CamContour_123CamContour31PressureatCam_124PressureatCam38PressureatCam_232Tappet_139Tappet_225Tappet40ValveStem_233ValveStem_126ValveStem27ValveFace34ValveFace_141ValveFace_242ValveSpring_235ValveSpring_128ValveSpring36NRFV_143NRFV_229NRFV1SHAF12SHAF23SHAF34SHAF45SHAF56SHAF67SHAF78SHAF89SHAF910SHAF1011SHAF1112SHAF1213SHAF1314SHAF1415SHAF16CamshaftPulleySB17SRBS18SRBS119SRBS220SRBS321SABS22RotExc65CrankshaftPulleyR摇臂结构排气单阀系平面挺柱结构进气单阀系简易皮带凸轮轴及轴承EXCITETimingDriveBasicTrainingTimingDriveDynamic605/18/2012Copyright©2012,AVLASTCHINAEXCITETimingDrive建模过程●全局坐标系：右手定则●𝑥旋转轴，常由前端指后端为正●𝑧轴垂直向上●𝑦轴右手定则确定●初始条件：曲轴第一拐朝上时，确定第一缸凸轮配气相位（V型机需特别注意相位问题）●建立并分析进/排气单阀系模型（以第一缸相位为准），存为用户模块或直接拷贝●调入进/排气单阀系模块，并复制●建立凸轮轴，定义轴段数据●确定各缸配气相位（发火顺序）●建立立皮带/链条驱动模块●合并成整个正时驱动系●施加驱动和外载●Simulation和ResultControl，进行计算EXCITETimingDriveBasicTrainingTimingDriveDynamic705/18/2012Copyright©2012,AVLASTCHINA凸轮轴建模●凸轮轴可用以下两种方式建立：●使用多个简易轴段建立凸轮轴●使用宏单元建立凸轮轴1SHAF12SHAF23SHAF34SHAF45SHAF56SHAF67SHAF78SHAF89SHAF910SHAF1011SHAF1112SHAF1213SHAF1314SHAF1415SHAF1In_CamShaft1C.45C.89C.1213C.1819C.202C.6C.10C.1421EXCITETimingDriveBasicTrainingTimingDriveDynamic805/18/2012Copyright©2012,AVLASTCHINA数据输入–轴段单元SHAF/SHPU●凸轮段、轴承段、轴段：分别用SHAF●皮带轮轴段/链轮轴段：用SHPU●各段为一集中质量点，有6个自由度（质量和惯量）●可根据x轴向位置，将本轴段与前轴段相连，考虑:●Y和Z向弯曲●X向扭转●X向拉伸/压缩●可以考虑弯曲和扭转振动●连接特性填在本轴段中（橙色箭头所指）轴承段凸轮段轴段凸轮段轴承段径向轴承推力轴承旋转驱动驱动轴发火顺序1SHAF2SHPU1SHAF2SHPU1234567注意：连接各单元时须沿着X轴方向建模，即说𝑋坐标位置小的单元是前单元1CAM12Bearing13CAM24SHAF15CAM36Bearing27CAM4EXCITETimingDriveBasicTrainingTimingDriveDynamic905/18/2012Copyright©2012,AVLASTCHINA数据输入–轴段单元SHAF/SHPU1SHAF2SHPU后连接：SHAF/SHPU/SHGE/SABS/SRBS/TRBE/CONN/NRFV前连接：SHAF/SHPU/SHGE1SHAF本轴与前轴间本轴段绕旋转轴惯量绕垂直轴惯量包括该轴段处的所有质量，如轮盘质量𝐶𝑜𝐺𝑑𝑎𝑙𝑑𝑖𝒙𝒛432xxIDl本轴段惯量(实心)2223()484zzDIDll质量和惯量：本轴段本轴段本轴段前段本轴与前轴段连接：填在本轴段模块中传递力及力矩的结果为本轴段的结果EXCITETimingDriveBasicTrainingTimingDriveDynamic1005/18/2012Copyright©2012,AVLASTCHINA数据输入–轴段单元SHAF/SHPU1SHAF2SHPUShaftProperties-Elasticity每段轴相对阻尼剪切面积率弹性模量E剪切模量G=E/2(1+v),v泊松比实心0.9考虑弯曲和扭转刚度COG1𝑥𝑦COG2前轴段本轴段l1l2l质心质心质心间距A1=d2/4横截面积A2横截面积各轴段阻尼：整轴由𝑛段组成（串连），则每轴段的相对阻尼为其中：𝐷为整个轴材料相对阻尼，可取𝐷=0.01等效截面积：●若为锥形轴，分成多段，分别取平均半径和质心间距等效截面2阶截面矩（绕𝑦,𝑧抗弯2阶截面矩,绕x抗扭2阶截面矩）实心/空心圆柱2阶截面矩绕𝑦和𝑧轴（抗弯）绕𝑥轴（抗扭）DnDShaf221121AlAlllAequ221121xxxIlIlllI6444iazyddII3244iaxddI123456125656EXCITETimingDriveBasicTrainingTimingDriveDynamic1105/18/2012Copyright©2012,AVLASTCHINA数据输入–轴段单元SHAF/SHPU1SHAF2SHPU皮带轮与轴的连接：●连接扭转刚度：考虑带轮与轴间的连接形式、连接表面质量等。●抗扭2阶截面矩约缩小为：●螺钉连接40%●螺栓连接50%●锥形连接70−80%●压力装配80−90%●弯曲特性：受连接方式的影响较小剪切面积率222221220167116aiaiaiSAddddddr64•𝑟𝑆𝐴剪切面积比•𝜈泊松比•𝑑𝑖轴内径•𝑑𝑎轴外径对于实心轴887.0SAr3.0CoGdaldixzyEXCITETimingDriveBasicTrainingTimingDriveDynamic1205/18/2012Copyright©2012,AVLASTCHINA数据输入–轴段单元SHAF/SHPU可选：考虑凸轮质心1SHAF2SHPU*C●凸轮质心的偏心量●若柴油机凸轮质心偏心较大，需考虑凸轮质心偏心产生的离心力影响●全局坐标下（𝑦−𝑧坐标系第一曲拐朝上），凸轮质心位置●建议：用3D模型直接获得精确值●估算：带凸轮的SHAF单元，偏出基圆的面积造成的偏心量为*43abC其中：𝑏−基圆半径𝑎−基圆半径+最大升程EXCITETimingDriveBasicTrainingTimingDriveDynamic1305/18/2012Copyright©2012,AVLASTCHINA29NRFV数据输入–ConnectionShaft-Valvetrain29NRFV后连接：CDAT前连接：SHAF/SHPU𝐶𝑟𝑎𝑛𝑘𝐴𝑛𝑔𝑙𝑒超前+CrankdegCrankdeg落后-Crankdeg计算气门曲线实际排气门升程实际进气门升程●凸轮型线数据：来自于CAMDesign（或图纸），必须0～360𝐶𝐴𝑀𝑑𝑒𝑔●CAMDesign中可知，该凸轮型线产生的计算气门最大升程点位置●实际气门与计算气门最大升程点的相位差（超前为正）EXCITETimingDriveBasicTrainingTimingDriveDynamic1405/18/2012Copyright©2012,AVLASTCHINA数据输入–ConnectionShaft-Valvetrain配气相位：实际气门比计算气门落后（负）140𝐶𝐴𝑀𝑑𝑒𝑔，故凸轮数据向后偏移发火顺序（1-2-3）：第一缸0𝐶𝐴𝑀𝑑𝑒𝑔；第二缸落后（负）120𝐶𝐴𝑀𝑑𝑒𝑔；第三缸落后（负）240𝐶𝐴𝑀𝑑𝑒𝑔实际进气门最大升程点计算气门数据落后-140第一缸换气上止点第一缸燃烧上止点29NRFV29NRFV1CDAT1EXCITETimingDriveBasicTrainingTiming