| 摘要 |
PURPOSE:To have an accurate sensing of the injection timing by changing the reference voltage level in accordance with the operating conditions, by sensing only valve lift signal generated within a certain specified range of crank angle and by removing signals from adjacent injection valves. CONSTITUTION:A lift sensor signal S1 is taken out of a sensor 7 by opening a fuel injection valve, and fed into an amplifier circuit 21 to obtain a signal S6. Besides normal signal component S61, this signal S6 contains an irregular signal component S62 to be generated owing to displacement of the needles of injection valves of adjacent cylinders. On the other hand, the angle signal S4 given by a crank angle sensor 23 is fed into an F-V converter 24 to have a convertion into variable voltage level signal S7, and then a sensing signal S8 is obtained through comparison of the amplification signal S6 with the variable voltage level signal S7 at a comparator circuit 22. The signal S7 is adjusted previously by the F-V converter so as to be always higher than the voltage level of the irregular signal component S62. Thus the irregular signal component is removed, and now the sensed signal S8 contains only normal signal components. |
