车辆工程专业英语.doc

车辆工程专业英语.docUNIT 5 FUEL INJECTION SYSTEM
燃油喷射系统
Fuel injection systems have been used on vehicles for many years. The earliest ones were purely mechanical. As technology advanced, electronic fuel injection systems became more popular. Early mechanical and electronic fuel injection systems did not use feedback controls. As emissions became more of a concern, feedback controls were adapted to both types of fuel injection systems.
feedback control 反馈控制
As emissions became more of a concern随着排放越来越受到关注
were adapted to 被应用于
Both mechanical and electronic fuel injection systems can be found on gasoline engines. Diesel engines are most commonly found with mechanical type systems, although the newest generations of these engines have been using electronic fuel injection(EFI).
gasoline engines 汽油 发动机
diesel engines柴油发动机
newest generations of 最新的
Basic Theory
EFI uses solenoid valves called injectors to meter fuel delivery. Most vehicles today use 1 injector per cylinder. When the solenoid is energized, fuel sprays out into the valve port. Fuel is delivered to the injector by a high-pressure electric pump at around 40 psi. Fuel delivery is controlled by the injectors which are cycled by the computer. The computer produces a signal to open the injectors for a certain length of time depending on engine conditions relayed by sensors・ The longer that the injector is open, the more fuel is injected. As engine load and rpm are increased, the injector open times are increased to match increasing airflow. This computer output signal is called the injector pulse width. The longer the pulse width, the more fuel is injected.
solenoid valves 电磁阀
injector喷油嘴，喷油器，喷射器
fuel delivery燃油输送，燃油供给
is energized ，供能，激发，，激励的，增能的energized line带电电路，带 电线路
valve port阀口，喷油嘴
psi [psai] 每平方英寸・・・•磅 =pounds per square inch
are cycled by周期性控制
engine conditions relayed by sensors传感器传送/输送回来的信号体现的发动机工作状况，简单的说， 即：传感器信号体现的发动机工作状况
injector pulse width喷油器脉冲宽度
Fuel System
Air Metering and Meas