明锐Greenline II新车型新技术培训(TT-121-S启停功能与能量回收).ppt

* * * * 电路原理 继电器 J680 为接线端 75 供电。J680 的控制信号从 J519 接线端 15 和接线端 50 的信号输入段由一个逻辑连接生成。 当点火开关通过 J519 开启，并通过继电器 J906 和 J907 接通供电继电器，以接通起动机接线端 50 时, 继电器 J681 打开。 起动机接线端 50 由发动机控制单元通过继电器 J906 和 J907 开启。 激活的接线端 50 将反馈信息发送回 J519 和 J623，已进行控制和诊断。 故障诊断的相应测量值供所有输入和输出信号所使用。 （配备 Kessy 和电子转向柱锁车辆的电路原理与接线端 15 和 50 的要求有所不同，见电路图。） * * * Modern engine management systems have running down detection for the signal of engine speed sensor G28 for when the engine is switched off. This means that even after the ignition has been switched off, the engine control unit can detect the extent to which the engine has continued to turn. Normally, it is assumed that the crankshaft is always turning to the right. To date, the fact that a crankshaft can – at the last moment of running down – turn back to the left has not been taken into account. Previous systems did not recognise this turn to the left as such, which meant that they assumed an incorrect crankshaft position when the engine was first turned on again. To make it easier and quicker to restart vehicles with a start/stop function, these engines have an engine speed sensor that also detects motion to the left by the crankshaft. Normal differential Hall sensors work internally with 2 Hall plates. Hall sensors that can also detect the direction of turn work internally with 3 Hall plates. One of the Hall plates detects a rising edge and a second detects a falling edge. The third Hall plate is between these two Hall plates but not exactly in the centre. This asymmetric arrangement enables the direction of rotation to be detected. The signals are processed by means of electronics in the Hall sensor. * Engine speed sensor without direction of rotation detection These two graphics show the signals of a traditional engine speed sensor at different speeds for the purposes of a comparison. In particular, note the time setting of the oscilloscope. Furthermore, you can clearly see that the low and high widths of the signals become shorter as the engine