【作者】 江坤；

【导师】 邓楚南；

【作者基本信息】 武汉理工大学 ， 车辆工程， 2009， 硕士

【摘要】 对大型客车而尤其是城市大客车而言,由于后置发动机总体布置方式的种种优点,后置后驱的驱动方式被越来越多地运用在汽车的整体布置上。但后置发动机汽车由于变速器和发动机一起布置在汽车的尾部,使得变速器离驾驶员座位较远,因而需要在变速器操纵手柄和换档拨叉之间安装一些辅助杠杆或传动机构,构成远程换档。同时,由于换档机构应具有足够的刚性,且各连接件间隙不能过大,否则换档时手感不明显。然而这种操纵机构操纵起来是比较费力的,为减轻驾驶员的劳动强度,使其有更多时间注意道路工况和车况,提高行驶安全性,迫切需要改进现有的换档操纵机构。本文立足于解决驾驶员在频繁进行换档操作时容易疲劳的问题,通过电子控制和气动操纵的方式,开发出一套电子控制单元和气动执行机构来取代目前后置发动机汽车拉杆/拉线式远程换档操纵机构,解决目前后置发动机汽车远程换档操纵困难的问题,减轻驾驶员的劳动强度,提高行驶安全性。同时,结合发动机的转速和车速,提示驾驶员做最佳换档选择,提高汽车燃油经济性。本文在分析车辆换档机构工作原理的基础上,开发出一套基于传统的6档机械变速器能准确进行选档和上档操作的电控-气动换档操纵机构,主要内容包括:(1)系统工作原理及机构分析在分析车辆换档机构工作原理的基础上,结合实验数据,设计开发一套基于传统的6档机械变速器能准确进行选档和上档操作的电控-气动换档操纵机构。(2)执行机构设计执行机构的换档操作主要由工作气缸来实现,本文设计开发一套能完成相应换档和选档操作的工作气缸,并对控制气缸工作的电磁阀进行原理分析和选型。(3)操控机构设计操控机构通过传感器判断当前司机的操作要求,并通过电子控制单元把司机的要求转换成指令发送给执行机构,同时接收来自执行机构的信号反馈,及时反馈给司机。主要包括档位传感器、车速传感器、发动机转速传感器的选择以及控制电路的设计。(4)控制系统硬件设计及软件设计系统的硬件电路部分是系统控制功能的基础,而软件是硬件的控制中心,是控制系统的核心,本文完成了控制系统的硬件电路设计和执行软件设计。更多还原

【Abstract】 For big bus , especially for the city buses, rear-engine in the overall arrangement possess varies of advantages, and therefore this kind of layout has been increasingly used in the overall layout of the vehicles. But rear-engine bus has both its engine and transmission system installed at the rear of the bus, and the transmission system is physically quite away from the driver-cabin in distance, therefore a few of assisting levers or mechanism should be incorporated linking the steer handle and gear-shifter, that is the remote-gear control. At the same time, the shifting agencies should be sufficiently rigid, and the connected space can not be too large, otherwise it can not be obviously detected by the drive when shifting. It is really tough to manipulate such kind of operate mechanism, in order to reduce the driver’s labor intensity, give the drive more time to pay attention to road conditions and improve traffic safety, it is urgent need to improve the existing institutions of the shift control.This paper is aimed to solve the problem that the driver may get fatigue during the frequently operation of shifting. Through the method of electric control and pneumatic operation, this paper develops a system in terms of electric control unit and pneumatic actuator mechanism to replace the existing rod/cable shifting agency. As a result it solves the problem of difficult to manipulate the remote-rear control of rear-engine bus, reducing the driver’s labor intensity and improve traffic safety. At the same time, the system will combine the speed of vehicle and engine speed, gives the driver the best choose of shifting to improve the fuel economic of vehicles.Based on the analysis of the working principle of transmission system, this paper develops a system in terms of electric control unit and pneumatic actuator mechanism based on the traditional mechanical six -election transmission. The main contents include:(1) Analysis the working principle and the institutional of systemBased on the analysis of the working principle of transmission system, combing the experimental data, this paper develops a system in terms of electric control unit and pneumatic actuator mechanism based on the traditional mechanical six -election transmission which can accomplish the shifting operation accurately.(2) The design of implement mechanismThe shifting operation of implementing agencies is mainly finished by the work cylinder, the paper design a series of work cylinder which can accomplish the shifting operation accurately. In addition, the paper analysis and select the solenoid valve which control the work of the cylinder.(3) The design of control systemThe control system detects the current shifting performance requirements of the driver through the sensors and the electric control unit converts the driver’s request into shifting command and send it to the implementing agencies. Meantime, it receives the feedback signal from the implementing agencies and feedback to the driver timely. It mainly includes the selection of stall sensor, vehicle speed sensor and engine speed sensor and the design of control circuit.(4) The hardware design and software design of the control system The hardware circuit is the basis of system control functions, while the software is the control center of the hardware and the core of the whole control system. This paper completed the design of hardware circuit and software design.更多还原