偏置电压对离子电流信号影响的试验研究

研究了在用火花塞作传感器直接测量发动机缸内燃烧状态时检测占所加的偏置电压对检测信号的影响，提出可获得所需离子电流信号的适当的偏置电压为200－600V，研究中发现：当偏置电压不同时，不仅离子电流的幅值和持续时间不同，而且其波形也有较大差异，在燃烧过程中会出现单峰，双峰和三峰现象，当偏置电压增至5KV时，驻燃烧过程中有离子电流信号，而且在进，排气冲程中，离子电流信号也异常突出，给出了不同偏置电压下离子电流的波形特征，获得了较为理想的离子电流信号的曲线，为用火花塞作为检测传感器实现汽油机缸内燃烧信号的检测奠定了试验研究基础。

Experimental Study of Influence of Bias Voltage on Ionic Current

The influence of bias voltage between probes of a spark plug on a signal of ionic current is studied and the proper bias voltage (200～600 V) is given, while using the spark plug as a sensor to detect burning in the cylinder of internal combustion engine. When the different bias voltages are applied the value and duration of the ionic current are different and the waveforms of ionic current also change. During the combustion process single high apex or double apices or three apices of ionic current have been found when the bias voltage increases. The ionic current appears not only in combustion process but also in inlet and outlet strokes while the bias voltage is 5 kV. The features of ionic current under different bias voltage are shown and the ideal signal of ionic current is obtained, so that the experiment foundation of spark plug as a sensor is set up and it can monitor burning in the cylinder of gasoline engine.