汽车前照灯雾气原理研究与应对措施

汽车前照灯配光镜内表面起雾问题是一个影响汽车照明和外观的重要课题,同时也是车灯行业的共性技术难题。为解决汽车前照灯配光镜内表面起雾而被客户误认为是进水的问题,本文通过水雾与水汽的形成机理,从前照灯温度场、气体流动场、材料特性等角度探讨前照灯雾气相应解决措施。     

汽车前照灯起雾原理分析及优化方案研究

汽车前照灯起雾一直以来是行业里的难题,尤其在中国市场,用户对于起雾现象接受程度不高,极容易被客户理解成车灯进水,导致引发售后抱怨及售后索赔。当使用环境较为苛刻、车灯起雾面积过大的话也会一定程度引起光分布的改变,使得远近光有效亮度降低,影响交通安全性。本文从原理角度分析了汽车前照灯的起雾机理,并且通过对试验测量的整灯内的温度分布及在温湿度试验箱做的各车型车灯起雾状态分析,提出整体优化框架及四种可行措施、并进行了对比试验,为各大主机厂提供了解决此问题的有效思路。     

降低前照灯进水起雾故障率的方法研究

通过调研汽车行业的前照灯进水、起雾现状,以某车型为例,从人、机、料、法、环6个维度,从根本上分析前照灯进水起雾的原因,并制定相应的优化对策,成功降低该车型的进水起雾故障率。     

汽车前照灯起雾原因分析

问题反馈 市场反馈前照灯内部起雾,长时间不能消散,影响车辆行驶,故障现象如图1所示。 技术核实 将市场故障件及其故障现象反馈前照灯生产供应商,供方按国家标准进行淋雨试验,试验后无雾气,符合技术条件。     

汽车前照灯雾气形成的数值仿真及应对措施

正半封闭式前照灯内部的水蒸气遇冷会在配光镜内表面形成珠状凝结,影响前照灯外观和照明效果。文中利用数直仿真手段对前照灯进行腔内温度分析和腔内流场分析,仿真结果与售后失效及物理实验一致。对前照灯内部雾气凝结机理进行了分析,指出凝结产生的必要条件,为前照灯起雾的改进措施制定提供系统性思路。     

奔驰车系电器故障11例

正1前照灯内有水雾故障现象奔驰汽车,底盘型号W166、212、213等,前照灯防尘盖内有水雾或小水滴。故障诊断与排除故障原因:前照灯虽然是封闭结构,但是湿气仍可通过两个来源渗入,一是通过吸收和解吸的物理现象进入,二是湿气被塑料吸收并在接通光源后通过解吸从塑料中释放出来,这导致车辆前照灯防尘盖上形成冷凝水。前照灯防尘盖上有自然形成的水雾或小水滴,说明前照灯已损坏,需更换。     

海拉首个创新孵化项目破壳

<正>海拉在2018年末创建了其在中国的科技创新中心——上海海拉汽车科技有限公司。该公司近日在海拉南京研发中心为首个创新孵化项目团队颁奖,肯定其取得的创新成果。此项目团队是由海拉南京研发中心的照明事业部和电子事业部5名研发人员共同组成。项目基于团队成员已获得的汽车前照灯除雾解决方案专利,结合海拉汽车照明和电子丰富的研发资源,仅历时百日实现了想法产品化。LED汽车前照灯结雾问题一直困扰着汽车制造商以及消费者。空气中的水蒸气     

汽车前照灯的技术革新

1车灯的分类 汽车照明光源种类繁多,作为汽车外装照明灯,首先是汽车前照灯(head lamp)、雾灯、车辐灯和转弯时用于弧线照明的曲线灯以及方向指示灯.汽车后部有刹车灯(Stop lamp)、方向指示灯、与前照灯同时燃点以在夜间显示车辆存在的尾灯、在停车场易于找到的有溯源反射特性的反光镜、倒车灯以及车牌照明灯等.     

上海市实施机动车夜间近光会车交通法规

上海市公安局1985年4月25日发出通告,于6月1日起实施机动车夜间近光会车交通法规,所有汽车一律换装符合“汽车前照灯配光性能 (GB4599-84)”标准规定的前照灯。同时规定了“机动车防眩目前照灯光调整办法和标准”及实施的具体要求。为保证贯彻执行该通告,由上海市公安局车辆管理所、上海汽车拖拉机销售服务公司、上海拖拉机汽车研究     

汽车前照灯配光性能的检测与调整

列表出了ＧＢ４５９９《汽车前照灯配光性能》中的近光和远光配光标准，阐述了检测汽车前照灯配光性能的具体方法，以及调整汽车前照灯光束时面符合的具体规定内容。     

CFD analysis of the flow in an automotive headlamp

In order to predict water condensation in an automotive headlamp at an early stage of the development process, CFD analysis of the flow in the headlamp was attempted.First, CFD analysis was conducted on the headlamp unit removed from a vehicle. The result was similar to the experimental result, thus the validity of this analysis was confirmed. Furthermore, water condensation in the headlamp on the vehicle was studied, based on the CFD analysis and the experiment. The results show that the water condensation in the headlamp is not only influenced by the velocity and temperature distribution in and around the headlamp, but also by the absolute humidity near the headlamp vents.     

汽车前风窗玻璃除霜除雾数值模拟分析和研究

利用CFD方法对汽车内部流场进行了模拟,定量分析了车内气流的速度、温度、湿度、以及车窗玻璃的温度和空气的传热量等参数,进而对汽车前风窗玻璃除霜除雾进行数值模拟,对其除霜除雾效率和效果进行分析,为汽车除霜除雾工程应用提供参考.     

Design of automotive headlamp with high-power LEDS

A novel vehicle headlamp low beam system is presented. The optical system is composed of three identical cells to ensure enough illumination. A poly-ellipsoid reflector and a aspherical lens are used to concentrate the rays and a baffle is employed to produce the cut-off line. The optical performance shows a good agreement with the requirement for headlamp in Chinese national standard. The smart constant current driver sustains automotive headlamps?requirements, moreover it has high power efficiency. The performance of three kinds of cooling systems with different structures are simulated and evaluated by FloTHERM software. Then a loop heat pipes combined with fins cooling system is manufactured for cooling the designed LED headlamp. It can greatly improve the cooling efficiency. Even in the 80°C environmental temperature, it can meet the working requirements of LED headlamp low beam system, so it is a kind of feasible cooling scheme.     

汽车前灯结雾分析及解决措施

车灯内部结雾是影响车灯质量的一个主要问题,同时也是一个世界性难题.空气中的水蒸气遇冷凝结在车灯灯罩内表面,不仅影响车灯外观,而且使车灯的照明效果大打折扣,影响行车安全.车灯结雾涉及流动、传热、材料及结构设计等方面的问题.本文是从热设计的角度对车灯内部流动场、温度场和浓度场进行分析,进而来探讨车灯内部结雾问题并采取措施进行解决的.     

某高强化柴油机进气道的设计开发

以未简化的某柴油机进气道为研究对象,使用三维流动力学软件完成了气道稳流试验台中气道-气缸流动的三维数值模拟计算,模拟计算的流场显示出了在气道试验台条件下空气流动过程的详细状况,气道性能评价参数(流通系数和涡流比)的流动计算结果与气道试验结果吻合较好.数值模拟精度表明,气道CFD计算可以为发动机开发中气道设计提供理论依据...     

3气门摩托车汽油机进气流动特性模拟

应用CFD对具有两个进气道的某3气门125 mL单缸汽油机气道内流场进行了数值模拟,在气缸横切面速度分布图上发现两个进气门的下方会形成两个尺度较大的横向空气流动漩涡;同时在纵切面速度分布图上发现明显的纵向气流漩涡流动,获得了不同升程下的进气流量系数;并将计算结果与试验结果进行了对比分析。结果表明,所选模型和计算方法正确,可以利用数值模拟计算代替试验测试得到进气门流量系数。     

柴油机伞喷喷嘴内部流动的数值模拟

对柴油机伞喷喷雾及喷嘴内部流动的研究现状进行了分析,利用三维计算流体动力学(CFD)程序对喷嘴内气穴多相流计算模型进行了验证,在此基础上对柴油机伞喷喷嘴内部的流动特性进行了模拟计算分析。结果表明,在伞喷喷嘴喷孔进口处形成不对称的气穴,并逐渐延伸至出口处,从而对燃油雾化产生一定影响。     

4G15D缸内直喷发动机油气分离模拟分析及试验验证

某4G15D缸内直喷发动机由于在缸盖罩位置布置高压油泵,导致气缸盖罩油气分离部分空间被占用,需要重新设计该款缸内直喷发动机油气分离结构型式。使用CFD仿真分析软件对发动机油气分离器内气液两相流场进行了数值模拟,分析了3种不同结构(改进前后)迷宫式油气分离器的流动分布、压力损失,采用离散模型模拟油滴粒子喷射,假定油滴粒子与壁面碰撞后即被捕捉,进而得出不同直径油滴的油气分离效率,根据仿真分析结果选择最优化设计方案;设计了一种简单而有效的试验方法对油气分离器分离效率间接进行验证。结果表明,采用CFD软件模拟计算方法能够计算出油气分离器油气分离效率,获得的结果反映了流动本质。在模拟分析过程中,油滴直径设定在1～15μm范围内时,根据所需要的油气分离效率优化设计油气分离结构,满足了最终产品要求。同时,在计算分析准确的前提下,提出了相应试验验证方法。     

Numerical and experimental investigation of lubricating oil flow in a gerotor pump

Gerotor pumps are widely used in the automotive industry for engine oil lubrication, due to their high volumetric efficiency and smooth pumping action. In many cases, the lubricating oil from the sump is mixed with contaminants, such as dust and tiny solid particles, or becomes thickened, due to aging. These problems will lead to critical situations, such as increased noise, enhanced wear and erosion, and poor lubrication of the engine. These critical situations were studied by conducting a detailed CFD integrated investigation on a gerotor pump’s performance at different operating conditions in three phases, and the results are presented in this paper. In first phase, a CFD model of a gerotor pump was developed with a dynamic mesh for the rotary movement of both the inner and outer rotors. The effects on pump flow rate of important parameters, such as rotor speed, fluid viscosity and number of ports, were simulated using non-contaminated oil at room temperature and an elevated temperature of 140oC. The relationship between flow rate and pressure at different rotor speeds was predicted and validated with test data for further parametric study. The pressure ripples at different time steps were measured at different angular positions of the rotors to examine the model accuracy. It was found that the flow rate increased and pressure pulsation, as well as flow recirculation, was reduced when ports were added to the cover plate. A suction pipe with a strainer was added for the second phase to capture the undesired changes in flow behavior, such as cavitation, which is caused by negative suction at the inlet region of pump. A suitable size for the inlet suction pipe for this pump was chosen after performing tests to characterize the flow behavior with single and double ports. Next, the relationship between pressure drop and strainer porosity was determined using different porosity values for the strainers. In the final phase, oil with different concentrations of solids was simulated to measure the effect of solid particles on flow rates and pressure losses. It was observed that the intensity of the recirculation was reduced at the suction end at the higher concentration of 0.04%, due to particle inertial effects. It was also found that particle size distribution affected the overall efficiency and pressure head of the pump.     

汽车灯配光镜中环面的光路计算

环面是汽车前照灯配光镜中广泛应用的一种面形，其光路计算法的优劣直接影响配光镜ＣＡＤ程序质量。本文给出一套全新的环面光路计算式，经对四种不同的前照灯所在的２００多万条光线的计算表明，这套光路计算法是适定的，快速收敛的。