东 莞 理 工 学 院
本 科 毕 业 设 计
毕业设计题目：汽车点火电路设计 学生姓名：李 扬 学 号：0641301224 系 别：电子工程学院 专业班级：06电子信息工程2班 指导教师姓名及职称：胡金莲 副教授 起止时间：2010年3月—— 2010年6月
摘 要
汽油发动机点火电路的作用是适时地提供电火花，点燃可燃混合气，使发动机工作。
本文介绍了无触点点火系统的设计方案，该方案主要通过安装在WFD026型霍尔效应式分电器内的霍尔传感器，将发动机运行的状态参数输入点火控制器，由点火控制器进行信号的处理输出点火脉冲，再由DQ170型点火线圈产生高电压使火花塞电极击穿，从而完成整个点火过程。本文所要研究的就是基于ZJ751型点火控制器进行设计的点火系统，ZJ751型点火控制器采用了SGTHOMSON公司生产的L497B集成电路以及外围电路来对霍尔信号进行分析、处理，实现一般点火电子组件的开关作用，并可对点火时刻进行控制，以达到汽油发动机在各种工况下，均工作在其所需要的最佳点火提前角，从而提高了点火能量，且不受发动机转速影响，高速不断火、低速能耗少，保证发动机混合气充分燃烧，提高发动机动力性，降低油耗和排放。
本文详细叙述了整个系统的设计和实现过程。
关键词 无触点点火 霍尔效应 开关管 闭合角 电流控制
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Abstract
The role of gasoline engine ignition circuit provide a timely supply spark,then ignite the flammable gaseous mixture,and make the engine start to work.
This article describes a Design of a non-contact ignition system.This system mainly through WFD026 by type of Hall Effect Distributor,to input the motor state parameters to the Ignition Controller.The ZJ751-type Ignition will output a signal of Ignition Pulse,then the DQ170-type Ignition Coil generate a high voltage,to make a Jump-spark,thereby,complete ignition process.My article supply the inside circuit of ZJ751.The IC of this system uses L497B as the main chip,produced by the SGTHOMSON corporation,implement signal acquisition and incentive control.Achieve the function of the switch in the general electronic components of ignition.The system is debugged and the real time control of the ignition advanced angle at any working conditions is realized.To improve the energy of ignition,and it is not affected by the speed of engine.Keep the fire in high-speed,low energy consumption.To ensure full combustion of the gaseous mixture.Increase the engine power,and reduces fuel consumption and emissions.
This paper describes the system design,techniques and methods of system implementation.
Key words Non-contact Ignition、Hall effect、Switch Transistor、Conductive Angel、Current Control
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目录
摘要····························································1
1.绪论···························································4 1.1 点火系的历史与发展·······································4 1.2 汽车点火系统的种类·······································5 1.3 霍尔点火系选题目的·······································6 2. 霍尔式点火系统准备知识····································7
2.1 霍尔式点火系统简介·······································7 2.2 霍尔效应·················································8 2.3 霍尔式点火电路组件介绍···································8
2.3.1 霍尔分电器·········································9 2.3.2 点火控制器········································13 2.3.3 点火线圈··········································14 2.3.4 火花塞············································15 2.4 霍尔式点火系统工作原理··································15 3. 普桑点火系统的设计········································17
3.1 设计要求·················································17 3.2 点火系统结构框图·········································18 3.3 普桑点火器设计···········································20 3.4 低压电路设计·············································28 3.5 高压电路设计·············································29 4. 点火电路的安装和调试·····································30
4.1 点火电路的安装···········································30 4.2 低压电路检测·············································31 4.3 高压电路检测·············································32 4.4 问题和故障分析以及解决方法·······························33 5. 课题总结····················································35
参考文献························································36 致谢····························································37 附件····························································38
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1 绪论
汽车电子点火系是当今电子技术飞速发展与具体应用相结合的一个典范。为更好的研究这一现代技术，在本章里，将介绍汽车点火系的历史、发展过程以及电子点火系的种类，最后再简单介绍本论文要研究、讨论的霍尔式点火系统。 1.1点火系的历史与发展
20世纪60年代以后，随着汽油机技术的不断发展，对各部分的性能提出了新的要求，如动力性、经济性及环保性，而这些指标在汽油机上是与点火系统有着较大关系的，因此人脉开始讨论如何提高点火系统的性能问题。尤其是70年代石油危机之后，全世界油价大幅度上升，导致各主要汽车厂商加速了其汽油机点火系统的研制，为满足新形势对汽车的要求，从而导数了电子点火系统的出现，特别是80年代之后，电子点火系统得到了迅速的发展与广泛的使用。
以前的点火系统称为传统的蓄电池点火系统，自从1910年在美国的CADILLAC汽车上首次装车应用以来，已有80多年的历史，几经改善，结构已定型，至今仍有数以百万辆的汽车在使用。但是随着人们对汽油机性能要求的不断提高，这种点火系统已不能满足工作的需要。如早期汽车点火电压只要10KV—20KV就可以了，而现在高速汽油机为提高经济性和环保性，广泛用了稀薄混合气技术，这客观地要求点火电压要达到15KV—30KV。为此需装用一种低阻点火线圈。但由于通过点火线圈的电流要比普通点火线圈的大许多，从而使断电器触电烧烛非常严重，难以满足使用要求。
仅上述一例已经充分说明了传统点火系统已经满足不了现代汽油机向高转速、高压缩比及多缸方向发展的需要。因此目前世界各国都在探索改进的途径，并生产了各种新型的电子点火系统。上世纪80年代后期的磁电式、霍尔式等点火系统，因无触点，无须保养，可靠性高，使用维护工作量大幅度减少，并且由于电子点火系统能产生更高的次级电压和火花能量，从而使汽油机起动更加容易，工作更加可靠，并且具有排气污染小，节约能源等优点；以及目前最新一代点火IGBT产品，智能IGBT线圈驱动电路的需求动因在于：功率开关的发展方向由外置的引擎控制模块变为直接位于引擎中火花塞上的点火线圈内的构件。当点火线圈位于火花塞上，这种结构称为“火花塞上线圈(coil on plug)”；当线圈
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