汽车继电器触点瞬态接触传热特性数值模拟分析

继电器是车辆电器控制的重要控制元器件,其工作环境是瞬间大电流通过周期性闭合的触点,由于接触触点间接触电阻在闭合瞬间大电流的作用下产生焦耳热,导致触点极易发生熔焊的可能,严重影响继电器的使用性能,危害行车安全,据统计触点部分的故障率占到继电器故障率的90%以上。揭示汽车继电器触点瞬态接触传热特性,对改善继电器触点触点熔焊故障具有重要的现实意。本文采用分型接触理论建立接触电阻模型,综合考虑触点间接触力、接触面积及材料的比热容、导热系数等,建立了继电器触点闭合瞬间大电流作用下的有限元模型,模拟计算触点间的瞬态热场分布,为改善继电器触头熔焊现象提供理论支撑。     

问答6则

１　小红旗轿车电气设备中采用的双触点继电器结构与使用有何特点？ 答：继电器是用一个小电流信号来控制一个大电流电路的接通与断开。小红旗轿车电气设备中除使用常见的单触点继电器外，还设计使用了新式双触点继电器，其结构见图１。 双触点继电器主要由两对触点、电阻、线圈及片式插头等组成。其两对触点是并联工作的，其中一对触点由纯银制成，体积较另一对触点大；另一对触点由纯钨制成。在继电器吸合工作时，纯钨触点３先闭合接通电路，大约在 ４０ ｍｓ～５０ ｍｓ时纯银触点６才闭合。而在继电器断开时，纯银触点６先断开，过４０ …     

一种新型长寿双触点汽车继电器的研究

电磁继电器是汽车上安装最多的电子元件之一,也是最易损坏的元件。传统的汽车继电器大部分采用单触点结构,触点基本上选用纯银材料或者是银基复合材料,几十年一惯制,没有大的改进。实践证明,汽车继电器由于长期工作在低电压,大电流状态下,在频繁的吸合、断开操作后,触点材料将发生相互的转移和侵蚀,由于材料转移大多发生在触点表面局部同一位置,因此触点表面极其粗糙,形状往往表现为凸凹不平,致使触点间的接触电阻不断增大,导致触点完全碳化,接触不良而失效,严     

长江CJ750摩托车点火系统的改进

长江CJ750型摩托车的点火系统为传统的触点式点火,由于初级电流是断电器触点接通和切断的,突出的问题是触点打开的瞬间,触点间易产生火花,将触点烧蚀,使接触电阻增大,造成初级电流减小,次级电压下降,火花能量减小。尤其是在发动机低速运转时,触点的烧蚀更加严重。同时,次     

喇叭工作时为什么要联接继电器

喇叭呜叫是靠汽车方向盘上的按钮来控制的。一般情况下单音电喇叭的工作电流是在2～7安培之间,个别厂家制造的喇叭工作电流还要大些。双音电喇叭工作电流是单音电喇叭的二倍,按钮处的电流将达到4～14安培,这样大的电流在按钮处产生的电弧,容易烧蚀按钮的接触表面。安装喇叭继电器后,由按钮来控制继电器线圈电流,线圈产生电磁吸力,将轭铁吸下,使触点闭合。工作电流     

空心白金的应用与反映

空心白金亦称环状白金,在汽车发达国家早已普遍推广应用。其特点是将分电器断电器的两个触点,改变为一个空心的和一个实心的,使传统实心触点的点接触改成为线接触,因而接触面积增大了,相对地通过的电流增大、电阻减小、灭弧性好、点火容易。并且由于有了中孔增加了触点间的空气流通,降低了触点温度,氧化现象有明显改善,白金的使用寿命有了明显的提高。我厂是一个白金触点与断电器总成的专     

北京牌BJ492Q型汽油发动机换向器式发电机调节器

调节器配套机型型号FT81E 型型式长期额定工作制、防尘式、换向器式汽车直流发电机调节器配套发电机ZF(?)2D 型调节器工作时的电路1.电压调节器触点11闭合时:激磁电流由发电机正极经激磁绕组,磁场接线柱17、轭架,电压调节器触点11、电流限制器触点9、铁芯,平衡电阻8、电枢接线柱15,回到发电机负极。2.电压调节器触点11打开时:激磁电流由发电机正极经激磁绕组,磁场接线柱17,附加电阻12,加速电阻14、铁芯,平衡电阻8、电枢接线柱16,回到发电机负极。3.电流限制器触点9闭合时:激磁电路与电压调节器触点11闭合时的情况相同。4.电流限制触点9打开时:激磁电流由发电机正极经激磁绕组、磁场接线柱17,再分为二路。一路经电压调节器触点11,附加电阻13、电枢接线柱16,回到发电机负极;另一路经附加电阻12、加速电阻14、铁芯、平衡电阻8、电枢接线柱16,回到发电机负极。     

继电器在摩托车上的应用

继电器的应用非常广泛,它由电磁线圈、衔铁、动触点、静触点等组成。对于其功能,我们可以理解为用小电流小电压去控制大电流大电压。同时其自锁功能也运用得非常多。原理如图1所示,按下常开按钮开关K1,继电器吸合,其触头1、2相接通,当松开按钮开关后,电路仍是通路,形成自锁。按     

再论汽车继电器触点电侵蚀

触点的电侵蚀是决定汽车继电器工作寿命和可靠性的主要因素，在对汽车用继电器触点电侵蚀进行论述了基础上，引用美国查克（Ｃｈｕｇａｉ）研究所韦特（Ｗｉｔｔｅｒ）等人的试验研究成果，获得了触点闭合和断开瞬间过渡过程的参数，对一些被人们忽略而又明显影响触点电侵蚀的因素进行分析，给出了技术数据，提出了汽车用继电器电侵蚀和电寿命试验规定条件中应注意研究的问题，供国内有关生产厂家、使用单位和工程技术人员参考。     

一种起动继电器触点的电路保护措施

正1背景介绍由于起动电机的控制电磁阀为电机类感性负载,在断开瞬间,因起动电机的控制线圈电感的特性,会产生较大的反向电压(一般为额定电压的2~3倍),此反向电压对控制起动机电磁阀的触点存在一定的危害,影响其寿命。为提高起动继电器的可靠性,抑制起动继电器的负载触点在断开瞬间因起动电机线圈产生的反向电压对继电器触点引起的伤害作用,需要相应的继电器触点保护措施。为此,本文详细介绍了一种简单、高效的保护措施。     

车用中央电气接线盒电热耦合仿真分析

以QC/T707车用中央电气接线盒技术条件所规定的负载程序加载至电路所产生的温升现象为研究对象,利用有限元分析软件ABAQUS建立零部件有限元模型,分析了多回路PCB线路、继电器插座、熔断器插座、继电器、熔断器和接触电阻替代零件模型等的温升现象并记录得到时间温升曲线。与试验室按照QC/T707的实物试验结果进行了数据对比,验证了所建立的模型及标定参数的可靠性,满足设计需求,也证明了该仿真分析推广至新产品开发设计验证及设计优化的可靠性。     

MOS管在电动车窗开关上的应用

为解决24V电动车窗开关继电器触点易烧蚀问题,采用大功率MOS管作为控制电流通断的元件,开关内部的继电器仅用于对电流方向进行切换,MOS管先于继电器进行电流通断控制,因此继电器本身不参与电流的通断控制,继电器触点无电火花就不存在烧蚀问题,提高了24V电动车窗开关的可靠性。     

基于数字图像技术的再生骨料沥青混合料骨架接触类型量化表征

新-旧骨料的接触类型及其比例决定了再生骨料沥青混合料的力学强度和耐久性.对比了再生骨料与天然骨料的物化特性差异,分析了AC-20C型再生骨料沥青混合料的路用性能,并通过截取试样断面图像、提取骨料接触点对再生骨料沥青混合料中不同骨架接触类型及其比例进行了量化表征.结果表明,与天然骨料相比,再生骨料针片状含量和表观密度降低...     

基于MC68HC908GZ60电器装置板的研究与设计

介绍笔者722007年为陕汽德御系列车设计的一款中央电器装置板。该电器装置板和传统的电器装置板的区别是取消了传统电器装置板上的专用继电器,整个电器装置板上所有继电器为通用继电器,所有功能通过一个MCU控制,该微机接收开关和传感器信号以及来自于车辆电子控制器的CAN信号,输出经过电流放大后控制各功能通用继电器,完成整车电器的控制。具有成本低、运行可靠的特点,可以很方便地实现复杂的电气控制功能。     

A New Wheel/Rail Spatially Dynamic Coupling Model and its Verification

Based on the theory of vehicle-track coupling dynamics, a new wheel/rail spatially dynamic coupling model is established in this paper. In consideration of rail lateral, vertical and torsion vibrations and track irregularities, the wheel/rail contact geometry, the wheel/rail normal contact force and the wheel/rail tangential creep force are solved in detail. In the new wheel/rail model, the assumption that wheel contacts rail rigidly and wheel always contacts rail is eliminated. Finally, by numeric simulation comparison with international well-known software NUCARS, comparison with vehicle-track vertical coupling model, and comparison with running test results by China Academy of Railway Sciences, the new wheel/rail spatially dynamic coupling model is shown to be correct and effective.     

A New Wheel/Rail Spatially Dynamic Coupling Model and its Verification

Based on the theory of vehicle-track coupling dynamics, a new wheel/rail spatially dynamic coupling model is established in this paper. In consideration of rail lateral, vertical and torsion vibrations and track irregularities, the wheel/rail contact geometry, the wheel/rail normal contact force and the wheel/rail tangential creep force are solved in detail. In the new wheel/rail model, the assumption that wheel contacts rail rigidly and wheel always contacts rail is eliminated. Finally, by numeric simulation comparison with international well-known software NUCARS, comparison with vehicle-track vertical coupling model, and comparison with running test results by China Academy of Railway Sciences, the new wheel/rail spatially dynamic coupling model is shown to be correct and effective.     

一种新的适合于铝合金点焊的电流控制法

在分析铝合金点焊过程中电极烧损与飞溅机理的基础上，提出了一种新的电流控制法，在这种控制法中电流分为焊接状态稳定化脉冲和焊接脉冲，前是几个不连续的小幅值电流脉冲，主要是使表面接触均匀化，接触电阻稳定在一个较小值，后的作用是加热工件，形成熔核，试验表明，该控制法可以有效地减少飞溅的发生，使电极的烧损变慢，变均匀，在连续点焊中还可以提高焊点质量的稳定性并降低对工件表面处理质量的要求。     

Simulation of dynamic interaction between train and railway turnout

Dynamic train-track interaction is more complex in railway turnouts (switches and crossings) than that in ordinary tangent or curved tracks. Multiple contacts between wheel and rail are common, and severe impact loads with broad frequency contents are induced, when nominal wheel-rail contact conditions are disturbed because of the continuous variation in rail profiles and the discontinuities in the crossing panel. The absence of transition curves at the entry and exit of the turnout, and the cant deficiency, leads to large wheel-rail contact forces and passenger discomfort when the train is switching into the turnout track. Two alternative multibody system (MBS) models of dynamic interaction between train and a standard turnout design are developed. The first model is derived using a commercial MBS software. The second model is based on a multibody dynamics formulation, which may account for the structural flexibility of train and track components (based on finite element models and coordinate reduction methods). The variation in rail profile is accounted for by sampling the cross-section of each rail at several positions along the turnout. Contact between the back of the wheel flange and the check rail, when the wheelset is steered through the crossing, is considered. Good agreement in results from the two models is observed when the track model is taken as rigid.     

Simulation of dynamic interaction between train and railway turnout

Dynamic train–track interaction is more complex in railway turnouts (switches and crossings) than that in ordinary tangent or curved tracks. Multiple contacts between wheel and rail are common, and severe impact loads with broad frequency contents are induced, when nominal wheel–rail contact conditions are disturbed because of the continuous variation in rail profiles and the discontinuities in the crossing panel. The absence of transition curves at the entry and exit of the turnout, and the cant deficiency, leads to large wheel–rail contact forces and passenger discomfort when the train is switching into the turnout track. Two alternative multibody system (MBS) models of dynamic interaction between train and a standard turnout design are developed. The first model is derived using a commercial MBS software. The second model is based on a multibody dynamics formulation, which may account for the structural flexibility of train and track components (based on finite element models and coordinate reduction methods). The variation in rail profile is accounted for by sampling the cross-section of each rail at several positions along the turnout. Contact between the back of the wheel flange and the check rail, when the wheelset is steered through the crossing, is considered. Good agreement in results from the two models is observed when the track model is taken as rigid.