【作者】 李波；

【导师】 汪永超； 曹明松；

【作者基本信息】 四川大学 ， 机械工程（专业学位）， 2021， 硕士

【摘要】 近年来,环境污染日益严重,再度引发人们对交通方式选择与使用的深思。同时随着居民消费结构的升级和消费水平的提高,人们对自行车产品的结构、功能、安全和质量等要求更为重视,因此自行车行业应不断创新以满足人们的使用需求。针对目前自行车的现状,本课题结合广大自行车用户在不同情况下的多种实际需求,运用优选算法筛选出用户关注度较高的需求,基于用户需求在传统自行车设计基础上,利用汽车差速原理研制了一款可实现双驱功能、更具市场竞争力的新型越野自行车,具体研究内容如下:首先,文章介绍了课题的研究背景、国内外自行车的研究现状以及发展趋势,阐述了课题研究的意义以及解释了课题研究的必要性。概括了自行车的分类与特点,并对自行车的主要结构与功能分解作了详尽的介绍。其次,通过实际考察调研,获取了广大自行车用户在不同情况下的多种需求。结合实际情况,提取出了最终有效的用户需求24项,并对其进行分类及层次分级。进一步建立自行车用户各需求的指标评价体系,结合可拓学理论与层次分析法构建用户需求模型,并利用可拓层次分析法对各级用户需求进行重要度求解和排序,进而选取出对用户最重要的前七项需求。此外,参考这些前七项用户需求,基于不同驱动原理提出前后双驱双轮自行车、脚踏手动双驱自行车以及差速驱动双驱自行车三种驱动方案,并通过分析各驱动方案之间的优缺点以及结合实际情况优选出最终驱动方案:差速驱动双驱自行车。再次,在确定驱动设计方案后,根据汽车差速原理对自行车的驱动方案进行改进,分析了双驱自行车传动系统的动力传递过程。对双驱自行车动力驱动装置的传动齿轮、十字轴、传动轴以及箱体等零部件进行详细的尺寸设计及结构设计。并且为了满足前轮既要提供动力又要实现转向的双重功能,创新设计了前轮转向机构。通过设计的动力驱动装置和前轮转向机构,保证了双驱自行车的动力源,解决了双驱自行车传动系统中前后轮动力传递的问题。然后,利用ANSYS软件对自行车的传动齿轮、十字轴、传动轴等主要传动零部件进行静力学分析,以评价其主要传动零部件的强度、刚度效果,仿真结果均满足设计要求。最后,对自行车的车体部分进行三维建模,在自行车车体的基础上,通过SolidWorks强大的设计装配能力对自行车各零部件进行装配,并检查各零部件的干涉情况,完成了双驱自行车整车三维模型。同时,对新型双驱自行车进行加工制造,并对其进行低速运动试验,通过实验验证了双驱自行车的骑行可靠性,动力驱动装置实现了自行车的前、后车轮都可以提供驱动力的目标,提高了自行车的动力性和安全性,并且前轮转向机构能够实现0°-45°角度范围内转向,连续骑行未出现脱链现象,提高了转向灵活性。更多还原

【Abstract】 In recent years,environmental pollution has become increasingly serious,which has once again aroused people’s deep thinking about the choice and use of transportation modes.At the same time,with the upgrading of residents’ consumption structure and the improvement of consumption level,people pay more attention to the structure,function,safety and quality of bicycle products.Therefore,the bicycle industry should continue to innovate to meet people’s needs.In view of the current status of bicycles,this subject combines the various actual needs of the majority of bicycle users in different situations,the optimization algorithm is used to screen out the needs of users with higher attention.Based on user needs,on the basis of traditional bicycle design,a new type of cross-country bicycle that can realize dualwheel drive function and is more competitive in the market is developed by using the principle of automobile differential speed.The research content is as follows:First of all,the paper introduces the research background,the research status and development trend of bicycle at home and abroad,expounds the significance of the research and explains the necessity of the research.This paper summarizes the classification and characteristics of bicycles,and introduces the main structure and function decomposition of bicycles in detail.Secondly,through actual investigation and research,the various needs of the majority of bicycle users in different situations have been obtained.Based on the actual situation,24 final and effective user needs were extracted and classified and hierarchically classified.Furthermore,establish an index evaluation system for the needs of bicycle users,combine the extension theory and Analytic Hierarchy Process(AHP)to build a user demand model,and use the Extension Analytic Hierarchy Process(EAHP)to solve and sort the importance of user needs at all levels,and then select the top seven requirements that are most important to users.In addition,referring to these first seven user needs,based on different driving principles,three drive schemes are proposed for front and rear dual-drive four-wheel bicycles,manual dual-drive bicycles with pedals,and differential-drive dual-drive bicycles.And by analyzing the advantages and disadvantages of each driving scheme and combining the actual situation to optimize the final driving scheme: differential drive doubledrive bicycle.Thirdly,after determining the driving design scheme,the driving scheme of the bicycle is improved according to the automobile differential principle,and the power transmission process of the double drive bicycle transmission system is analyzed.The size design and structure design of the transmission gear,cross shaft,transmission shaft,box and other parts of the double drive bicycle power drive device are carried out in detail.And in order to meet the dual functions of the front wheel which not only provides power but also realizes steering,the front wheel steering mechanism is innovatively designed.Through the design of the power drive device and front wheel steering mechanism,the power source of the double-drive bicycle is ensured,and the problem of power transmission between the front and rear wheels in the transmission system of the double-drive bicycle is solved.Then,in order to evaluate the strength and stiffness effect of the main transmission parts of the bicycle,the static analysis of the transmission gear,cross shaft,transmission shaft and other main transmission parts is carried out by using ANSYS software.The simulation results meet the design requirements.Finally,the three-dimensional modeling of the bicycle body was carried out,and based on the bicycle body,the bicycle parts are assembled through the strong design and assembly capabilities of Solid Works,and the interference of each part is checked,and the three-dimensional model of double-wheel drive bicycle is completed.At the same time,the new type of dual drive bicycle is manufactured and tested at low speed.The riding reliability of the dual drive bicycle is verified through experiments.The power drive device realizes the goal that the front and rear wheels of the bicycle can provide driving force,and improves the power performance and safety of the bicycle.In addition,the front wheel steering mechanism can realize the steering within the angle range of 0-45 degrees,and there is no chain off phenomenon during continuous riding,which improves the steering flexibility.更多还原