传感器工作间隙对内燃机瞬时转速测量的影响机理及规律

Influence Mechanism and Law of Sensor Working Clearance on Instantaneous Engine Speed Measurements

为研究传感器工作间隙变化引起瞬时转速测量误差的机理,从磁电传感器电压特性出发,考虑传感器支架振动、齿盘安装偏心及曲轴弯曲振动3种因素,推导得到工作间隙变化情况下输出电压和瞬时转速的统一表达式,并对转速测量误差进行了量化,阐明了作用机理;研究了各因素对瞬时转速误差影响规律,得出满足工程误差(角位移小于0.1°)要求限值的计算方法;研究了基准电压对瞬时转速误差的影响规律,得出取0基准电压可消除3个因素中调幅部分影响的结论.为改善瞬时转速测量精度提供了理论依据.

To study the mechanism of the instantaneous speed measurement error caused by the variations of sensor working clearance,on the basis of voltage characteristics of magneto-electric sensor,and considering the three variation sources from sensor bracket vibration,fluted disc installation eccentric and crankshaft bending vibration,a unified expression of output voltage and instantaneous speed was derived,then the speed measurement error was quantized and its mechanism was elucidated. The influence of various factors on the instantaneous speed measurement error was studied. Calculation method of error limits that meet the engineering requirements(angular displacement less than 0.1°)was achieved. Effect of reference voltage on the instantaneous speed measurement error was discussed with conclusion that zero reference voltage could eliminate the impact of amplitude modulation(AM). The research provides a theoretical basis for the improvement of the accuracy of instantaneous speed measurement.