柴油机共轨系统ECU的设计及喷油特性研究

电控共轨系统的共轨压力和喷油量能够进行独立控制，因此它表现出传统燃油喷射系统所无法比拟的优势。采用高性能的32位MC68332型单片机开发了电控单元，实测了基于HEUI（Hydraulic Electronic Unit Injector）增压式喷油器的喷油规律，以研究影响共轨系统喷油规律的因素。结果表明，喷油器的机械结构在一定程度上决定了喷油特性，而一个强有力的驱动电路有助于提高喷油器的响应速度。随着共轨压力的升高，喷油速率提高；喷油控制脉宽的增大延长了阀门打开时间，使喷油持续期延长。通过调节共轨压力和控制脉宽可获得灵活的喷油规律。

Design of ECU for Common Rail System of Diesel Engine and Study of Injection Characteristics

Electronically controlled common rail system presents many advantages since the common rail pressure and injection quantity can be controlled independently.An electronic control unit(ECU) for realizing the controlling functions was developed,and experiments on the injection system based on HEUI injector were conducted,and the factors influencing the injection characteristics were studied.The results indicate that the mechanical structure of the injector determines the injection performance to some extent,while a strong drive circuit for the injector can promote responsibility.With the increase of pressure in common rail,the injection rate will increases.Moreover,extension of control pulse width will increase the valve opening duration and injection duration.The flexible injection characteristics can be realized through controlling common rail pressure and pulse width coordinately.