汽车设计课程设计说明书
题目:重型载货汽车动力总成匹配与总体设计 姓名:严炳炎 学号:200924267
同组者:孔祥生、席昌钱、余鹏、李朋超、郑大伟
专业班级:09车辆工程2班 指导教师:王丰元、邹旭东、李树成 设计时间:2012. 9.3-2012. 9.9
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青岛理工大学课程设计
目 录
设计任务书························································3 第1章 整车主要目标参数的初步确定·································4
1.1、发动机的选择············································4 1.1.1、发动机的最大功率及转速的确定························4 1.1.2、发动机的最大转矩及转速的确定························5 1.2、轮胎的选择··············································6 1.3、传动系最小传动比的确定··································6 1.4、传动系最大传动比的确定··································7 第2章 传动系各总成的选型·········································8
2.1、发动机的选型············································8 2.2、离合器的初步选型········································9 2.3、变速器的选型············································10 2.4、传动轴的选型············································11 2.5、驱动桥的选型············································11 2.5.1、驱动桥结构形式和布置形式的选择······················11 2.5.2、主减速器结构形式选择································12 2.5.3、驱动桥的选型········································12
第3章 整车性能计算···············································13
3.1、配置潍柴WD615.50发动机时的整车性能计算·················13 3.1.1、汽车动力性能计算····································13 3.1.2、汽车经济性能计算····································15
第4 章 发动机与传动系部件的确定··································16 设计总结··························································17 参考文献··························································18 附录······························································19
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青岛理工大学课程设计
设计任务书
载货汽车汽车动力总成匹配与总体设计
1、整车性能参数
设计一辆用于长途城际物流运输,最大总质量不超过31t,额定载重质量为16t,最高车速为100km/h的重型载货汽车(售价不高于对标竞争车型)。 整车尺寸(长*宽*高) 11976mm*2395mm*3750mm 轴数/轴距 4/(1950+4550+1350)mm 额定载质量 16000kg 整备质量 12000kg 公路行驶最高车速 100km/h 最大爬坡度 ≥30% 2、具体设计任务
1) 查阅相关资料,根据设计题目中的具体特点,进行发动机、离合器、变速箱
传动轴、驱动桥以及车轮的选型。
2) 根据所选总成进行汽车动力性、经济性的估算,实现整车的优化配置。 3) 绘制设计车辆的总体布置图。 4) 完成至少1万字的设计说明书。
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青岛理工大学课程设计
第1章 整车主要目标参数的初步确定
1.1 发动机的选择
1.1.1 发动机的最大功率及转速的确定
汽车的动力性能在很大程度上取决于发动机的最大功率。参考该题目中的参数,按要求设计的载货汽车最高车速是ua=100km/h,那么发动机的最大功率应该大于或等于以该车速行驶时,滚动阻力功率与空气阻力功率之和,即
1magfCDA3(umax?uamax) (1-1) Pemax??T360076140式中,Pemax是发动机的最大功率(KW);ηT是传动系效率(包括变速器、辅助变速器传动轴万向节、主减速器的传动效率),ηT=95%*95%*98%*96%=84.9%,传动系各部件的传动效率参考了机械工业出版社的《汽车设计课程设计指导书》表1-1得;Ma是汽车总质量,Ma=28000kg;g是重力加速度,g=9.8m/s2;f是滚动阻力系数,由试验测得,在车速不大于100km/h的情况下可认为是常数。取f=0.008,参考《汽车设计课程设计指导书》表1-2得;CD是空气阻力系数,一般中重型货车可取0.8~1.0,这里取CD=0.9;A是迎风面积(㎡),取前轮距B1*总高H,A=2.395×3.75㎡。
CDA?0.9?2.395?3.75m2?8.1m2
故
Pemax
128000?9.8?0.0080.9?2.395?3.75?(?100??1003)KW?197.2KW0.849360076140也可以利用比功率的统计值来确定发动机的功率值。
如选取功率为197.2KW的发动机,则比功率为
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