汽车专业毕业论文

北京工业职业技术学院毕业论文用纸 | 西安科技大学 毕业论文（设计）文件

题 目 ： 电控系统的故障诊断 函 授 站 : 西安城市交通技师学院 专业班级 : 汽车检测与维修14高汽2班 姓 名 : 徐高辉 指导教师 ： 宋超产 日 期 ： 2016年10月 实用精品文档

目 录 前 言 ----------------------------------------------------- 第 1 章 绪论---------------------------------------------------- 5 1.1 波形分析法概念--------------------------------------------- 5 1.2 故障诊断机理----------------------------------------------- 5 1.3 信号的类型。----------------------------------------------- 5 1.4 信号特征--------------------------------------------------- 6 1.5 波形诊断分析机理------------------------------------------- 6 第 2 章 波形分析------------------------------------------------ 7 2.1 次级高压电火波形分析-------------------------------------- 7 2.11 分电器点火次级阵列波形------------------------------------ 7 2.12 分电器点火次级阵列波形（急加速）-------------------------- 8 2.13 分电器点火次级单缸波形------------------------------------ 9 2.14 电子点火(EI)次级单缸波形----------------------------------11 2.15 电子点火次级单缸急加速波形--------------------------------13 2.16 无分电器/电子点火线圈压力试验-----------------------------14 2.17 电子点火作功及排气点火测试--------------------------------16 2.2 初级低压点火波形分析--------------------------------------17 2.21点火初级闭合角波形-----------------------------------------17 2.22点火初级线圈电流波形---------------------------------------19 2.23分电器点火初级阵列波形-------------------------------------21 2.24分电器初级阵列波形(调整时基和触发)-------------------------22 实用精品文档

2.25分电器初级单缸波形-----------------------------------------23 2.26电子点火初级单缸波形---------------------------------------24 2.27点火正时及参考信号-----------------------------------------24 第 3 章 故障案例-------------------------------------------------28 3.1 喷油器电阻过大---------------------------------------------28 3.2 喷油器供电线路虚接-----------------------------------------28 3.3 喷油器线圈短路---------------------------------------------29 致 谢-----------------------------------------------------------30 参考文献---------------------------------------------------------31 实用精品文档

前言 随着汽车电子信息技术的迅速发展，汽车上装用的电子设备越来越多，这就对今天的汽车故障诊断提出了新的挑战。如何快速、准确地诊断出汽车电子控制系统故障，是现代许多汽车维修人员面临的难题。 众首周知，对电控系统的故障诊断大致有四种方式：万用表诊断，故障码诊断，数据流分析和波形分析。目前，我国汽修行业对解码器的使用已十分普遍，大多数维修人员都掌握了利用解码器对故障的诊断。但是，准确诊断汽车故障只有解码器是不够的。有维修经验的人都知道，绝大都数解码器只能解决当仪表板上的“故障灯”亮时系统所监测到的故障，但问题是系统故障灯不亮时而故障码存在情况，如汽车电子控制系统中的传感器和执行器在长时间的使用过程中会磨损、腐蚀、老化、变形等。它们的性能也随之变差，此时电控单元往往就不能判定它们有故障。此外，即使 “故障灯”亮时解码器读出了故障码，有时也很难判断一个复杂电控系统的故障部位，此时利用检测设备中的示波器功能对所怀疑部位进行波形测试，便可使维修人员快速了解被检测部件的工作性能，从而快速找到故障零部件。 关键词：波形分析 故障诊断 点火峰值 实用精品文档

Abstract With the rapid development of automobile electronic information technology, Auto fit with a growing number of electronic devices, which in today's automobile fault diagnosis presented new challenges. How to fast, accurate diagnosis of automotive electronic control system, is the modern challenges faced by many automotive maintenance staff. The first known, on the fault diagnosis of electric control system there are basically four ways: multimeter diagnosis, diagnostic fault codes, data flow analysis and waveform analysis. At present, China's automobile repair industry on the use of decoders has been widespread, most maintenance staff have mastered the use of a decoder to fault diagnosis. However, accurate fault diagnosis of automobile only decoder is not enough. Maintenance experience knows that, most of the vast number decoder can only be resolved when the dashboard ' fault light ' light failure detected by the system when, but the problem is the system fault light to be lit and fault code existence, such as sensors and actuators in automotive electronic control system in use for a long time wear, corrosion, ageing, during deformation. Their performance also variation, electronic control units often cannot determine at this time they failed. In addition, even if ' fault light ' light decoder when read out of the trouble code, sometimes it's difficult to tell a complex electronic control system fault, oscilloscope features in using detection devices at this time to wave the suspect parts test, it can be detected so that maintenance personnel quickly understand is part of work performance to quickly isolate the failing component.

Keyword: Waveform analysis Fault diagnosis Ignition peak