| 摘要 |
PURPOSE:To surely control an EGR (exhaust gas reflux) valve and to surely detect malfunction of it by installing a detector of the amount of valve opening to feedback it to a control unit, together with an alarm which is actuated when the ratio of the amount of valve opening to a set value is over a fixed value. CONSTITUTION:A shaft 60 is equipped with a detector 26 of the amount of valve opening. The output of the detector is feedbacked to a control circuit 28. Also installed is an alarm 42 which is actuated when the ratio of the output of the detector 26 to the output of an EGR amount-setting arithmetic and logic unit 24 is over a fixed value. Thus, since the amount of opening of an EGR valve 20 is always watched, the EGR valve 20 can be surely controlled. In addition, since when the valve of the EGR valve 20 is sticked to its valve seat, or its diaphragm is cracked, the alarm 42 is actuated, a trouble of the EGR valve can be surely detected. |
