自行车、电动自行车产品质量存隐患

我国是一个自行车生产和消费的大国，自行车是我国城乡居民的主要短途代步工具，同时自行车作为一种综合代步、健身、竞技、娱乐等多功能产品，受到消费者的青睐。近年来，自行车工业发展迅速，生产的社会化、专业化程度越来越高，每年生产数千万辆各种花色、规格的自行车，社会拥有数亿辆，已成为名副其实的     

2000年第4季度自行车产品质量国家监督抽查结果

自19世纪初第一辆自行车问世以来,自行车已成为一种综合代步、运输、健身、竞技、娱乐等多功能的产品,日益受到消费者的青睐。为促进我国自行车产品质量不断提高,规范自行车行业的发展,引导消费,2000年第4季度,国家质量技术监督局组织对自行车产品质量进行了国家监督抽查。本次抽查了30家企业的30种样品,合格20种,产品抽样合格率为66.7％。     

自行车上的 中国

<正>壹关于自行车的时间轴清朝时期同治七年(1868年)11月,自行车从欧洲来到了上海,人坐在车上,两脚踮地引车而走的娱乐性代步工具。同治十三年(1874年),人力车从日本来到了上海,人力车又称为"东洋车",因其多为黄色又叫"黄包车",成为代步工具。随后上海兴起了人力车的修、租、贩制业。光绪十年(1884年),中国出版的《申江胜景图》首次记载了中国开始出现骑自行车的情景:"人如踏动天平,亦系前后轮,转动如飞,人可省里走路。不独     

N-bike折叠自行车的设计研究

 为了使折叠自行车既骑行舒适又易携带,对车架、链盒等主要部件进行受力分析及优化设计.设计出的N-bike自行车,经过5次完成折叠,体积为0.03 m³,质量为5.4 kg,车架为“N”字型形状,根据人机工程学原理设计,布局合理.N-bike骑行更舒适,传动更省力,实用性强,外形动感时尚,更适合作为城市便捷的代步工具．     

折叠自行车设计研究

简述了自行车的发展及现状,分析了在我国发展折叠自行车的可行性及重要性.基于对国内外自行车发展趋势的理解和认识,介绍了一款人性化、合理化的折叠自行车的设计方案.     

《共享自行车第2部分:电助力自行车》

<正>我国电动自行车生产主要依据的是国家强制性标准GB 17761-1999《电动自行车通用技术条件》。此标准是1999年制定的,目前在行业中形同虚设,不符合标准的车型在市场上比比皆是。共享电助力自行车是电动自行车中的一个类型,如果继续这样无序地发展将给用户带来非常大的安全隐患,必然会遭到各地政府的封杀。为此,有必要在共享自行车的体系下制定共享电助力自行车的产品标准。与《共享自行车第1部分:自行车》团体标准     

电动自行车

电动自行车,是指以蓄电池作为辅助能源在普通自行车的基础上,安装了电机、控制器、蓄电池、转把闸把等操纵部件和显示仪表系统的机电一体化的个人交通工具。经历了10余年的产业发展,中国电动自行车以     

自行车、电动自行车

近日,国家质量监督检验检疫总局对自行车、电动自行车产品质量进行了产品质量国家监督抽查。此次抽查涉及天津、上海、江苏、浙江等4个省市68家企业生产的68种产品,合格47种,产品抽样合格率为69.1%。其中:抽查了自行车28种,合格17种,产品抽样合格率为60.7%;抽查了电动自行车40种,合格30种,产品抽样合格率为75.0%。抽查结果表明,自行车、电动自行车的产品质量良莠不齐。从总体质量状况来看,生产设备和检测手段比较完备的企业、产品的零部件配置较高的产品,其产品质量就比较好。一些小型企业,缺乏对产品的整体设计和质量把关检验,购置低档配件…     

5种自行车不好骑

国家质检总局12月1日公布的自行车、电动自行车质量抽查显示,自行车和电动自行车的抽样合格率是69.1％。这次抽查了天津、上海、江苏、浙江这4个自行车和电动自行车的主产地,一共抽查了68家企业。存在的主要问题是,有的自行车和电动自行车的车架不够结实,在骑行中可能出现车架断裂、车把扭曲或鞍座松动等情况,容易造成交通安全事故。 国家质检总局公布了5种不合格的自行车、电动自行车和它     

当前自行车设计趋势与自行车通勤文化探讨

（随着建设节约型社会方针政策的进一步推动,自行车再次进入人们的生活主题。继90年代以后,自行车在中国的人均持有量就一直属于下滑趋势,如今由于当下路面交通状况的不佳,人们开始重新选择自行车作为生活通勤的交通工具,这也跟人们对慢速生活的心理需求、自行车设计审美改变、自行车设计空间提供、自行车实现多功能需求、自行车文化活动等有着重要关系。     

The safety of electrically assisted bicycles compared to classic bicycles

Use of electrically assisted bicycles with a maximum speed of 25 km/h is rapidly increasing. This growth has been particularly rapid in the Netherlands, yet very little research has been conducted to assess the road safety implications. This case–control study compares the likelihood of crashes for which treatment at an emergency department is needed and injury consequences for electric bicycles to classic bicycles in the Netherlands among users of 16 years and older. Data were gathered through a survey of victims treated at emergency departments. Additionally, a survey of cyclists without any known crash experience, drawn from a panel of the Dutch population acted as a control sample. Logistic regression analysis is used to compare the risk of crashes with electric and classical bicycles requiring treatment at an emergency department. Among the victims treated at an emergency department we compared those being hospitalized to those being send home after the treatment at the emergency department to compare the injury consequences between electric and classical bicycle victims. The results suggest that, after controlling for age, gender and amount of bicycle use, electric bicycle users are more likely to be involved in a crash that requires treatment at an emergency department due to a crash. Crashes with electric bicycles are about equally severe as crashes with classic bicycles. We advise further research to develop policies to minimize the risk and maximize the health benefits for users of electric bicycles.     

Development of the zinc-air power battery on electric bicycles in China

Electric bikes powered by lead-acid batteries have developed very fast for several years in China. Because the inconvenience caused by the service performance and the inconsistency to the environmental protection policy of the lead-acid battery, the zinc-air power battery was proposed to solve the problem in this paper. The advantage and the feasibility of developing zinc-air power batteries in China have been illustrated in the paper. And, it is represented that development of electric bikes powered by the zinc-air power battery also can accelerate this kind of battery’s development in other electric vehicles, which is favorable to economic development and environmental protection.     

Safety effects of permanent running lights for bicycles: A controlled experiment

Making the use of daytime running lights mandatory for motor vehicles is generally documented to have had a positive impact upon traffic safety. Improving traffic safety for bicyclists is a focal point in the road traffic safety work in Denmark. In 2004 and 2005 a controlled experiment including 3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group and 2000 other bicyclists, the latter serving as a control group without bicycle running lights. The safety effect of the running lights is analysed by comparing incidence rates – number of bicycle accidents recorded per man-month – for the treatment group and the control group. The incidence rate, including all recorded bicycle accidents with personal injury to the participating cyclist, is 19% lower for cyclists with permanent running lights mounted; indicating that the permanent bicycle running light significantly improves traffic safety for cyclists. The study shows that use of permanent bicycle running lights reduces the occurrence of multiparty accidents involving cyclists significantly. In the study the bicycle accidents were recorded trough self-reporting on the Internet. Possible shortcomings and problems related to this accident recording are discussed and analysed.     

Estimating the risk of collisions between bicycles and motor vehicles at signalized intersections

Collisions between bicycles and motor vehicles have caused severe life and property losses in many countries. The majority of bicycle-motor vehicle (BMV) accidents occur at intersections. In order to reduce the number of BMV accidents at intersections, a substantial understanding of the causal factors for the collisions is required. In this study, intersection BMV accidents were classified into three types based on the movements of the involved motor vehicles and bicycles. The three BMV accident classifications were through motor vehicle related collisions, left-turn motor vehicle related collisions, and right-turn motor vehicle related collisions. A methodology for estimating these BMV accident risks was developed based on probability theory. A significant difference between this proposed methodology and most current approaches is that the proposed approach explicitly relates the risk of each specific BMV accident type to its related flows. The methodology was demonstrated using a 4-year (1992-1995) data set collected from 115 signalized intersections in the Tokyo Metropolitan area. This data set contains BMV accident data, bicycle flow data, motor vehicle flow data, traffic control data, and geometric data for each intersection approach. For each BMV risk model, an independent explanatory variable set was chosen according to the characteristics of the accident type. Three negative binomial regression models (one corresponding to each BMV accident type) were estimated using the maximum likelihood method. The coefficient value and its significance level were estimated for each selected variable. The negative binomial dispersion parameters for all the three models were significant at 0.01 levels. This supported the choice of the negative binomial regression over the Poisson regression for the quantitative analyses in this study.     

Overtaking, rear-end, and door crashes involving bicycles: an empirical investigation

Recent emphasis on bicycling as an alternative to automobile transportation has underscored the need for research efforts directed at bicycle safety when sharing roadways with motorised vehicles. Much of the research attention is focused on junction accidents where motorists tend to infringe upon bicycles’ right of way. Non-junction accidents where a motorist strikes a bicycle while overtaking it, or crashes into the rear of the bicycle, have been less frequently researched. Another common crash type is a door crash that involves a bicycle striking an open door of an automobile. Using British Stats19 accident data, the present study estimates a mixed multinomial model to predict the likelihood of a non-junction crash being of a certain crash type (out of three possible types). The methodological approach adopted allows for the individuals within the observations to have different parameter estimates (as opposed to a single parameter representing all observations). Main findings include that buses/coaches as collision partners were associated with overtaking crashes; and bicycles’ traversing manoeuvres were associated with overtaking and rear-end collisions. Given a crash where a bicycle collides with a motorcycle/taxi, it is more likely a rear-end crash and a door crash, respectively. Implications of the research findings, the concluding remarks, and recommendations for future research are finally provided.     

电动自行车电机装配质量检测系统设计

在介绍电动自行车用永磁轮毂无刷直流电机的结构及装配质量检测原理的基础上,研究了通过虚拟仪器实现电机装配质量在线检测的方法,并构建了检测系统.该系统由采样电阻和电流传感器及其调理电路,以及美国国家仪器公司(NI)的6008数据采集卡构成.实验表明,该系统工作精度及效率完全满足电机总装检测的需要,对电机的不良率统计及故障原因分析具有重要意义.     

Fatigue of clamped connections with application to a stem‐handlebar assembly for off‐road bicycles

The objectives of this study were: (i) to determine the stresses as a result of assembly and the stress concentration of a clamped connection, (ii) to demonstrate the importance of the effects of assembly in fatigue life predictions and (iii) to verify the accuracy of fatigue life predictions by measuring fatigue life experimentally. A stem‐handlebar assembly used in off‐road bicycles was chosen for the study because it is a critical assembly for which structural reliability must be insured to prevent serious injury. Assembly stresses in the handlebar exceeded 200 MPa and stress concentration because of the attached stem increased the applied stress by 40%. A stress‐life prediction indicated that assembly effects would reduce predicted fatigue life of the handlebar by a factor of approximately 20. The measured fatigue lifetime of the handlebar was longer than that predicted by using the stress‐life approach, but was much shorter than that predicted when assembly effects were ignored. Therefore, assembly effects have a significant effect on fatigue life predictions and should be included in lifetime assessments for clamped mechanical assemblies.