| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a trouble detection method for detecting a short circuit trouble in an injection device when an engine is started. <P>SOLUTION: The injection device is provided with one or a plurality of piezoelectric fuel injectors 12a and 12b, and the injectors are connected in a drive circuit 20. In one embodiment, a potential VB at a bias point PB in the drive circuit is determined to be compared with a predicted voltage VPB. In a case where the potential at the bias point is not within a prescribed tolerable voltage VTOL of the predicted voltage, a short circuit trouble signal is generated. In another embodiment, a first charge pulse is applied to the injector to charge the injector. After the first charge pulse, a discharge switch Q2 is closed to provide a discharge current way 38 within a delay periodΔt. A defective injector makes a discharge through the discharge current way within the delay periodΔt. After the delay period, a second charge pulse is applied to the injector. In a case where current IS is detected during the second charge pulse, and when the current in the second charge pulse is larger than a prescribed threshold current, a short circuit warning signal is generated. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
