汽车排放污染治理利器车载诊断OBD系统(八)

正曲轴箱通风(PCV)系统监测的故障标准:(1)如果曲轴箱与PCV阀,或者PCV阀与进气歧管之间断开连接,OBD系统会检测出故障。(2)对所有形式的外接PCV系统的管路和软管,如果它们用于平衡曲轴箱压力,或者用于对发动机的不同区域进行通风,那么这些管路、软管断开或损坏,OBD系统会检测出故障。(3)OBD系统对曲轴箱通风系统按照OBD基本监测条件进行监测。     

一种曲轴箱通风系统结冰问题的解决方案

针对发动机曲轴箱通风系统在寒冷条件下结冰失效问题,文章介绍了采用发动机冷却液对曲轴箱通风系统管路进行加热,以及针对局部结构位置进行保温的方案解决发动机曲轴箱通风系统在寒冷条件下结冰问题。     

汽油发动机曲轴箱通风系统的研究

本文详细介绍了汽油发动机曲轴箱通风系统的型式、工作原理及闭式曲轴箱通风系统的设计.     

柴油机闭式曲轴箱通风系统设计及其对排放的影响

随着排放法规的升级,发动机采用闭式曲轴箱通风将成为一种趋势,但曲轴箱通风携带的油雾和PM等污染物会对发动机零部件造成污染,同时对发动机性能也会产生影响.为降低该影响,针对一台直列4缸柴油机上采用缸盖罩盖内集成预分离器,再串联一个外置分离器的两级分离曲轴箱通风方案,在发动机台架上进行了曲轴箱通风机油携带量的试验,并与开式...     

曲轴箱通风呼吸管结冰问题解决方案

分析极寒环境下,发动机窜气在呼吸管处凝结致使曲轴箱压力升高,导致机油尺弹出或曲轴箱后油封失效漏油等问题。介绍通过曲轴箱通风系统中全负荷呼吸管的更改设计,提出解决方案并进行试验认证,以保证车辆在极寒环境下正常运行。     

重视发动机废气排放控制系统的检查

现代汽车由于对废气排放要求的日益严格,在发动机上附加了许多装置以控制车辆的排放,其主要有PCV(曲轴箱强制通风)系统、EGR(废气再循环)系统、EVAP(燃油蒸发排放控制)系统、TWC(三元催化)系统以及EAI(二次空气导入装置)和AIS(二次空气喷射装置)。这些系统由于是控制废气排放,对发动机性能影响似乎不大,往往被忽视,使维修作业走许多弯路。     

车用发动机油气分离器的设计匹配

在分析发动机曲轴箱通风系统形式及几种油气分离器结构特点的基础上,确定了曲轴箱通风系统的设计方案:滤网油气过滤+旋风式油气分离器+PCV控制阀。在发动机机油量为标准值、最小值、最大值增加20%工况下,进行了全负荷曲轴箱通风试验。结果表明,所开发的曲轴箱通风系统在活塞窜气量增加1倍时,油气分离器和PCV控制阀之间无可见油流,曲轴箱漏气量和曲轴箱压力符合评价指标要求,提高了油气分离效率。     

曲轴箱通风系统压力波动对机油溢出的影响

某一自然吸气发动机在开发过程中曲轴箱通风系统机油溢出严重,但通过常规稳态参数测试无法说明机油溢出的原因,于是采用瞬态压力传感器对曲轴箱通风系统连接管路进行瞬态压力波动测量,并通过更换不同孔径的稳压腔来改变系统的压力波动,查看机油溢出状态。试验结果表明,曲轴箱通风系统连接管路的压力波动会影响曲轴箱机油溢出,解决问题的同时也给出了该曲轴箱通风系统设计时的压力波动参考范围。     

车型 哈弗H5车(搭载4D20B发动机)

正故障现象该车高速行驶中发动机突然熄火,且无法起动着机。故障诊断将车辆拖回修理厂,检查发现机油严重不足,但未见漏油痕迹。观察排气管,发现有大量油渍,怀疑发动机烧机油,决定拆解气缸盖进行检查。拆下发动机装饰罩盖,发现连接至进气管的曲轴箱强制通风波纹管弯折(图5)。与车主沟通得知,该车1周前进行过维护,由此推断维修人员维护时拆过曲轴箱强制通风波纹管,但安装时没有正确复位,导致该波纹管弯折。分析     

柴油机曲轴箱通风系统试验研究

针对某款柴油机试验过程中曲轴箱通风系统出口出现的大量机油问题,在试验台架上测量了其在不同工况下的机油溢出量,在排除发动机窜气量及窜气中机油含量高等原因后,根据发动机在整车上的安装角度,分析了该曲轴箱通风系统机油溢出量高的原因。采用橡胶膜片单向阀,在储油腔内壁增加6°斜槽,同时优化预分离结构后,得到了曲轴箱通风系统的优化方案。试验验证表明,橡胶膜片阀式的曲轴箱通风系统在整个机油溢出试验中机油溢出量很少,满足该发动机的设计要求。     

某款电动车体的设计及静态和模态有限元分析

随着计算机软硬件的发展,CAE技术日趋成熟,产品完成初步设计后,基于CAD模型进行产品性能的虚拟实验在企业中应用越来越广泛,本文以某款电动车体为研究对象,简单介绍了其设计和运用有限元法进行静态和模态分析过程。利用Hyperworks软件建立其有限元分析模型,然后导入Ansys进行后处理,得出静态和模态的相关结果,为改进设计提供依据。     

整车总布置设计对碰撞控制策略的影响

新车设计初期阶段,总布置设计需要对整车关键尺寸和关键零部件结构设计提出约束条件,以控制整车性能指标。碰撞作为整车关键性能指标,对总布置提出了更高的设计要求。文章阐述了总布置设计中,对整车、车身及关键零部件的控制策略,以确保整车在碰撞时可以按照设计过程碰撞,达到相应碰撞得分。表明总布置设计对整车碰撞控制策略有很大的影响。     

电动汽车动力电池管理系统的设计与研究

能源危机和生态危机产生的人类生存压力越来越明显,汽车产业受能源危机和生态危机的双重影响,电动汽车的研发俨然是大趋势。电动汽车的问世减少了环境污染,缓解了生态压力,而其也减少了能源消耗,在解决能源枯竭问题方面有着积极意义。其研发与应用得益于其电池管理系统的设计优化,这也是新型能源汽车研发中的核心命题。本文主要就电动汽车所对应的电池管理系统进行设计方面的系统研究,以通过硬件与软件的系优化设计,带来电池管理系统的优化,带来电动汽车研发的新革命,使得其性能逐步提升,助力新能源汽车产业的创新发展。     

Optimum SUV bumper system design considering pedestrian performance

Until recently, passenger cars have primarily interested in pedestrian protection performance. Nowadays, however, it is important for a sport-utility vehicle (SUV) to meet the bumper system standards for pedestrian safety. For a SUV bumper system, there are some difficulties in attaining a high level of pedestrian performance for the lower legform. An SUV has a high bumper position from the ground level, and the bumper approach angle must also be secured, which has an effect on car insurance fees. Due to these reasons, it is difficult to meet the pedestrian performance of the lower legform for an SUV. In this paper, a comparative study was performed on various SUV bumper systems, and a concept model for a SUV bumper system was developed, which is expected to meet the pedestrian performance by using the Pugh method. The design control factors were defined to affect the bumper pedestrian performance through the experiences of tests and analyses. For the noise factor to affect the pedestrian performance, the deviation of the impactor position was selected at the moment of impact. The design control factors were optimized by using the Taguchi optimization technique. For the Taguchi method, an L18 orthogonal array table of design control factors was used in the optimization process. Particularly, for the optimization of the bumper corner region, an optimization analysis was performed three times to meet pedestrian performance. Based on the results of the Taguchi optimization method, the sensitivity of the bumper design parameters was studied, and a new SUV bumper system is proposed that satisfies the pedestrian performance of the lower legform. The optimized bumper system should obtain a full Euro-NCAP score of 6 points for the bumper test. The pedestrian performance of the optimized bumper system is validated by using a CAE (Computer Aided Engineering) analysis, which has been proven to be in accurate. A comparison between the test and analysis results is shown for the validation of accuracy. By using the optimized bumper system, the tests and development costs of a bumper can be reduced.     

The Lateral Dynamics of Motorcycles and Bicycles

The paper is a review of the state of knowledge and understanding of the steering behaviour of single-track vehicles, with the main accent on vehicle design, and vehicle design analysis and behaviour prediction.

The body of the paper consists of a chronological account of the steps which have been taken in establishing the current position. Scientific study of the motions of two-wheelers has been in progress for more than 100 years, but progress was slow and many conflicting conclusions were drawn until increasing understanding of tyre mechanics, systematic application of the laws of motion for systems of rigid bodies, digital computation and modern numerical methods, and improved mobile measurement, recording, and data processing capabilities allowed the pace to accelerate.

The current position, which is that a good understanding of the relationship between design and performance has been achieved, but that by no means have all the problems of significance been solved, is described at the end of the paper.     

透水铺装雨水入渗模型与影响因素相关性研究（双语出版）

为了更加准确快捷地预测透水铺装内部的雨水渗流过程，探究降雨参数与路面设计参数对其渗流性能的影响，提出透水铺装雨水入渗模型，并针对影响因素的相关性进行研究。首先，基于地区水文气象资料与路面材料渗透特性，利用数学模型对降雨阶段关键参数进行量化研究，并从降雨强度与材料渗透能力的角度对雨水入渗的物理过程进行分阶段刻画，最终建立透水铺装雨水入渗-储水-排空模型。其次，针对该模型的诸多输入参数，进行正交设计试验计算各参数与径流控制率的相关性，寻找关键控制指标；基于该结论拟定典型透水铺装结构组合，选择不同降雨重现期、降雨历时与时程雨型等模拟工况对水位高度、蓄水能力等进行验算与评价。结果表明：所建模型与文献数据具有较好的吻合性，NSE指数可达0.45以上；路基土的渗透系数与路面径流控制率显著相关，暴雨工况下随着路基土渗透系数的降低，地表径流占比达到30%以上，并且几乎丧失连续储水能力，而路基土饱和渗透系数的影响性较小；溢流管可有效减少地表径流量，降低溢流风险，在极端暴雨条件下设置溢流管的道路可削减60%的地表径流，并具有50%以上的连续储水能力；时程雨型对路面渗流特性的影响较为复杂，雨峰出现时间在控制地表径流与延缓径流峰值两方面呈现相反的规律，因而需要根据当地降雨资料与设计要求进行权衡。     

汽车蓄电池线热缩管选型及应用设计

随着汽车工业发展,汽车对性能、稳定性、成本的要求越来越高,对材料、性能定义也更加科学。汽车零部件产品的要求更加苛刻,各大主机厂及供应商对零部件的设计要求统一性、标准化也日渐完善。本文针对汽车线束行业热缩管的选型及应用设计进行科学论证和分析。     

The Lateral Dynamics of Motorcycles and Bicycles

SUMMARY

The paper is a review of the state of knowledge and understanding of the steering behaviour of single-track vehicles, with the main accent on vehicle design, and vehicle design analysis and behaviour prediction.

The body of the paper consists of a chronological account of the steps which have been taken in establishing the current position. Scientific study of the motions of two-wheelers has been in progress for more than 100 years, but progress was slow and many conflicting conclusions were drawn until increasing understanding of tyre mechanics, systematic application of the laws of motion for systems of rigid bodies, digital computation and modern numerical methods, and improved mobile measurement, recording, and data processing capabilities allowed the pace to accelerate.

The current position, which is that a good understanding of the relationship between design and performance has been achieved, but that by no means have all the problems of significance been solved, is described at the end of the paper.     

高速公路抗裂型水泥稳定碎石基层应用研究

水泥稳定碎石具有强度高、板体性好、经济性好等优点,是我国使用最广泛的半剐性基层材料,但水泥稳定碎石存在突出特点易开裂。娄新高速公路基层采用新型抗裂型水泥稳定碎石,从材料本身抗裂性能评价方法研究人手,提出骨架密实型水泥稳定碎石基层材料理论设计方法,采用振动压实法进行配合比设计,使基层整体强度更加均匀,密实度更高,增强了基层的强度及抗水损害性能,并对其抗裂性能进行了室内对比试验研究,通过试验路检测与后期观测数据分析,基本达到了抗裂型水稳碎石基层高强度、抗开裂、抗水损害的预期效果。     

基于E—NCAP行人碰撞保护的发动机罩设计

行人头部碰撞保护一直是汽车行人安全设计的难点,随着E—NCAP对行人保护要求的不断提高,头部保护的得分比重对于获得高星级评价至关重要。文章基于某车型E—NCAPV6．2五星性能开发,采用虚拟仿真与试验测试有效结合的方法,对发动机罩进行了优化设计,提出了一种有利于行人头部碰撞保护的发动机罩。改进前后测试成绩的对比分析表明,该结构可极大优化行人头部碰撞保护效果,使发动机罩头部测试区域得分总分提升至24．43分,满足E—NCAPV6．2五星行人保护性能要求。可为后续设计提供参考,具有很高的推广价值。