【作者】 田冠；

【导师】 项忠霞；

【作者基本信息】 天津大学 ， 机械工程， 2012， 硕士

【摘要】 论文结合某邮政局提出的对现用邮政投递自行车的改进需求,探讨了基于骑行安全性与舒适性的自行车设计方法。全文研究内容及结论概括如下:一、利用有限元方法,分别对国外某型邮政自行车和国内邮政自行车在不同骑行条件和载货条件下进行了强度分析。利用分析数据,将两种车型进行对比,结果显示:虽然两种邮政自行车均符合强度要求,但是在应力分布、结构合理性等方面,该国外邮政自行车的设计优于国内邮政自行车。二、基于骑行安全性要求,结合邮递员工作特点,对现用邮政投递自行车的车架结构及相关零部件设计提出了合理的改进方案。三、对国内邮政自行车的前叉进行了有限元强度分析,找出了其容易失效的原因。同时,以降低最大应力值和轻量化为目标,提出了两种改进方案,并进行了对比分析,给出了合理方案。四、借助表面肌电信号测试手段,对不同受试者在骑行过程中下肢表面肌电信号进行了采集。通过对信号的时域、频域分析,验证了基于人体生物力学的自行车仿真设计方法的有效性。通过分析实验数据,提出了频域指标MF的线性拟合方程的斜率可以作为自行车骑行舒适性的评价指标。采用该指标对国外和国内邮政自行车的骑行舒适性进行了对比,结果表明:前者的骑行舒适性优于后者。该论文的研究成果对于自行车的自主创新设计具有重要的理论意义和实际应用价值。更多还原

【Abstract】 In this paper, according to the Post Office’s need to improve the mail bicycle, design method of mail bicycle based on riding safety and comfort is discussed.The main research achievements are shown as follows:1. Based on the consideration of riding safety, fatigue strength of Chinese and another country’s mail bicycles under different cycling and loading conditions are checked using finite element method before the following contrast. The result shows that although the two products both meet the fatigue strength requirement, the another country’s one is apparently superior in distribution of stress, structural rationality, etc.2. Considering the recent bicycle structure and working environment of mail carriers under the preconditions of riding safety, some reasonable plans of bicycle structure and spare parts are proposed.3. According to the Post Office’s real need, the Chinese bicycle’s front fork is checked in finite element method in order to find out the reason of its break. At the mean time, two new improvement plans are brought forward to reduce maximum stress as well as quality. The best plan which can not only improve the stress distribution of front fork under heavy loading conditions, but also make the quality range under control is searched in different ways.4. In order to study the riding comfort of mail bicycle, the cycling experiment with surface electromyography analyzing method is made which involves different cyclers. Time and frequency domain analysis are made to testify the validity of simulation whose purpose is to measure the muscle forces as well as to improve bicycle designing theory. At the same time, the conclusion is drawn that another country’s bicycle is superior to the Chinese one in the consideration of muscle fatigue through the slope of linear fitting equation of MF which is seen as an evaluation index for muscle fatigue. This evaluation index is used to make a comparison between the recent and another country’s mail bicycles on riding comfort and it shows that the former one is superior to the latter one.The achievement of this paper offers a great value to the innovation of bicycle designing method in theoretical and practical ways.更多还原