车辆工程专业英语.doc

UNIT 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 monly 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 puter. puter 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. puter 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 v. 使通电,供能, 激发,加强 adj. 通电的,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 Measureme