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FSAE-悬架,1,悬架组工作内容:,悬架构件的设计与制作，如立柱，导向杆系，摇块，推杆以及车轮构件设计与制造。 悬架的调试，检查杆系的干涉，悬架参数，车轮定位参数的调试。 协助配合各小组的工作，如与转向，车架小组的配合。,2,准备工作及学习内容：,熟悉双横臂悬架的结构特点及组成。 熟悉悬架对操纵稳定性的影响。 熟悉车轮定位参数的作用及特点。 掌握一般的悬架设计准则。 熟练运用三维制图软件，仿真软件。 参阅外文文献，熟悉规则。,3,设计目标,设计悬架的目的是轮胎工作更容易且使其行为可预测，让车手能够控制住车。悬架应有助于保持轮胎和地面之间固定接触，使得轮胎能够发挥出最大作用。也就是使外倾角、轮距变化尽可能小，轮胎接地面积尽可能大。,4,悬架定义：,悬架是汽车的车架与车桥或车轮之间的一切传力连接装置的总称。,悬架功用:,传递作用在车轮和车架之间的力和力扭，并且缓冲由不平路面传给车架或车身的冲击力，并衰减由此引起的震动，以保证汽车能平顺地行驶。,悬架组成：,弹性元件，导向机构，减震器，横向稳定杆等。,5,双横臂悬架：,典型的双横臂悬架,6,一般FSAE赛车的前后悬架：,7,8,规则要求：,The car must be equipped with a fully operational suspension system with shock absorbers, front and rear, with usable wheel travel of at least 50.8 mm (2 inches), 25.4 mm (1 inch) jounce and 25.4 mm (1 inch) rebound, with driver seated. The judges reserve the right to disqualify cars which do not represent a serious attempt at an operational suspension system or which demonstrate handling inappropriate for an autocross circuit All suspension mounting points must be visible at Technical Inspection, either by direct view or by removing any covers. Ground clearance must be sufficient to prevent any portion of the car, other than the tires, from touching the ground during track events. Intentional or excessive ground contact of any portion of the car other than the tires will forfeit a run or an entire dynamic event. The wheels of the car must be 203.2 mm (8.0 inches) or more in diameter.,9,The track and center of gravity of the car must combine to provide adequate rollover stability Rollover stability will be evaluated on a tilt table using a pass/fail test. The vehicle must not roll when tilted at an angle of sixty degrees (60) to the horizontal in either direction, corresponding to 1.7 Gs. The tilt test will be conducted with the tallest driver in the normal driving position,10,初步设计步骤：,初步定义参数、悬架几何： 1，车轮的选择。 2，轴距和轮距的选择。,加速或制动时轴距较大会有较小的载荷转移，增大了转弯半径，转弯时动作大。轴距小时有较小的转弯半径，可能会在出弯和直线行驶中表现紧张,轮距越大，转弯时的横向负荷转移就越小，大轮距也有劣势，就是车辆避障时需要更多的横向运动。,11,3，主销内倾，磨胎半径和外倾角。主销内倾角03，磨胎半径030mm,外倾角0-4。,外倾角和磨胎半径重点考虑,12,4，立柱pickup点及立柱尺寸.,13,5，主销后倾和拖距。,Caster and Trail:front： 6 caster with a trail of 41.589mm. Rear:caster was consequently 11.937 with a trail of 83.613mm,后倾角和拖距对于悬架几何的设计是很重要的。后倾角会导致车轮随转向而抬升和下降。拖距越大，转向力矩越大。,14,6, 侧倾中心和瞬时中心:,前轴侧倾中心比后轴的低，且变化方向一致，位置变化较小。前轴侧倾中心一般050mm，后轴稍高。,15,7，抗点头、抗下蹲暂不考虑。,16,8.几何草图模型,根据布置等因素考虑，确定硬点坐标。,17,9.建立仿真模型,根据硬点连接拓扑关系。,18,10.试验台仿真模型,19,11.仿真曲线,通过仿真得到很多想要的曲线关系，更容易观察其特性。,20,12.优化设计,通过反复做实验，修改硬点及几何参数达到设计要求。,21,13.三维实体模型,确定零部件，连接件规格大小，外形。由三维建模软件建立实际的零部件，装配图。,22,Thank you very much for your attention,23,
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