汽车专业英语 FUEL INJECITON SYSTEM.ppt

6 Oxygen Sensor This sensor is employed in closed loop systems to modify the basic pulse width after the fact. It is mounted into the exhaust manifold area. Chapter 5 FUEL INJECTION SYSTEM 译文： 氧气传感器被用在闭环系统来根据实际情况调整基本脉冲宽度。它位于排气歧管区域。 By looking at the oxygen content of the exhaust gases after combustion, the computer can determine if the air/fuel ratio is too rich or too lean for optimum combustion and adjust the next few injections accordingly. This sensor is primarily employed for emission control and to a lesser degree, fuel economy. For the lowest average emission, the air/fuel ratio must be kept around 14.7 to 1. Chapter 5 FUEL INJECTION SYSTEM 译文： 通过检测燃烧后排放的废气中氧气的含量，计算机能判断出对于最佳燃烧而言，空燃比是否过浓或过稀，从而调整接下来喷油量。氧气传感器首先被用来排放控制，其次用于燃油经济性控制。对于最低的平均排放，空燃比必须要控制在14.7：1左右。 Under full throttle conditions, this sensor is ignored by the computer so that the engine can produce more power. This is called open loop mode and the computer is supplying the injector pulse width from tables based on all of the other sensors inputs. Chapter 5 FUEL INJECTION SYSTEM 译文： 当节气门全开状态下，氧气传感器的输入被计算机忽略，从而使得发动机产生更大的功率。这被称作开环模式。此时，计算机根据其他传感器的输入信号基于数据表提供喷油嘴脉冲宽度。 Once throttle opening and rpm are reduced to cruising conditions, most systems will jump back into the closed loop mode where they will stay for a large portion of the time on most street driven applications. Chapter 5 FUEL INJECTION SYSTEM 译文： 一旦节气门开度和发动机转速减小到巡航状态，大多数系统会再回到闭环控制模式。对于大多数街道驾驶的情况，系统主要采用闭环控制模式。 7.basic operation As explained in the Basic Theory section, the computer processes all of the voltage signals from the various sensors to determine the engine operation conditions at the moment and delivers the appropriate pulse width to the injectors. Chapter 5 FUEL INJECTION SYSTEM 译文： 正如基本理论一节中所介绍的，计算机处理来自不同传感器的所有电压信号来判断发动机所处的实时工况，并向喷油嘴发送适当的脉冲宽度。 7.basic operation If engine airflow increases by 10%, the pulse width is also increased by about 10% to keep the air/fuel ratio constant. If the rpm is doubles from 2000 to 4000 rpm, the num