【作者】 丁彭刚；

【导师】 刘欣；

【作者基本信息】 大连理工大学 ， 精密仪器及机械， 2008， 硕士

【摘要】 随着社会的进步和生活水平的提高,汽车工业得以长足发展,人们对车辆的功能和性能提出了更高的要求。目前,我国多数城市客车均采用发动机后置,使用手动机械变速装置,在车辆行驶过程中,驾驶员要反复、频繁进行起步、换档和停车操作,劳动强度很大,燃油经济性和乘坐舒适性较差,同时也存在着严重的交通事故隐患。借鉴国内外多年的研究经验,同时结合我国的实际情况,研究开发了性价比较高的客车轻便换档系统。系统在原有手动变速器基础上进行机械机构改造,将手动换档改为电控气动轻便换档,以电子控制单元为核心,通过气动执行机构完成预定选换档操作,实现客车换档的轻便化。系统结构简单,效率高,生产继承性好,改造费用投入少,性价比高,具有重要的理论意义和应用价值,发展前景广阔。本文介绍了客车换档系统的历史、现状及发展趋势,从客车传动系统中的离合器和同步器的工作原理入手,介绍了客车的换档过程。文章阐述了轻便换档系统的总体方案设计,详细描述了控制机构和执行机构的结构设计。在机械结构基础上,本文还详细阐述了控制机构和执行机构的硬件电路设计,包括信号采集电路、电磁阀控制、主备用控制单元及其它外围硬件电路的设计,并对出现和预知的故障进行了诊断,且提出了解决方案。文章然后介绍了CAN总线在系统中的应用,包括硬件节点的设计以及通讯协议的制定等,同时进行了系统软件流程的设计。最后对设计的硬件电路和系统软件进行了调试,确定系统能够正常运行。更多还原

【Abstract】 With the development of modern society and the improvement of living standards, the automobile industry has been developed fleetly, and people demand more about the functions and capabilities of vehicles. At present, most city buses adopt the postposition engine and manual mechanical transmission. When the vehicles run, drivers must do the manipulation of start, gearshift and stop repeatedly and frequently, so the working intensity is very large and the comfort capability and fuel economy is bad. Also there are serious latent troubles of traffic accident. Using the research experience for reference in home and abroad,and according to our national actual situation, we developed an Electronic Pneumatic Shift System that has a good cost performance ratio.Based on the original manual gear box, the mechanical machine is redesigned and the manual gear box is replaced by the electronic transmission. The system takes the ECU as the control kernel and utilizes the method of the Electronic Pneumatic Shift to complete the prospective shift operation. This system can not only maintain simple structure and high efficiency, but also have high manufacture facility and high performance-price proportion. So this project has important academic significance and applied value.This thesis introduces the history, current situation and developing trend of the transmission system. The work theories of transmission, clutch and the synchronization machine are introduced firstly and then shift processes are discussed in details. Subsequently, the blue print of whole system with the structural design of the control and the implement unit are expounded. Based on the mechanical structure, this thesis has also expoudsed its hardware circuit design,including signal circuit, electromagnetic valve control circuit, the main control and the implement unit and other circuit. This thesis also expouds the diagnosis to the possible malfunction of the whole system, and bring forward the solutions. The application of CAN-Bus is also introduced, including the node hardware design and the frame of the communication protocol. At the same time the system software based on the the hardware is also designed. Finally the hardware and software are testd to make sure the whole system can work smoothly.更多还原