| 摘要 |
PURPOSE:To make easy the arrangement, maintenance and inspection of engine, by the correction of duty ratio at maximum and minimum flow so that it is not at 100% and 10% and fixing it to the limit value if the corrected value is in excess of the limit value set. CONSTITUTION:In the ON-OFF electromagnetic valve supplying pulse signal to the ON-OFF electromagnetic valve and controlling the flow based on the ON-OFF ratio, the amount of exhaust return of the automobile engine 11 is controlled 20 with the ON-OFF electromagnetic valve 10. This control circuit 20 selects the pattern of exhaust return set according to the state of operation in advance and determines the basic duty given to the electromagnetic valve 10. Thus, the duty ratio is corrected so that it is not 100% and 10% at maximum and minimum flow, and if the corrected value is in excess of the set limit value, programming is made so as to fix to the limit value. Thus, the operating condition of the electromagnetic valve 10 and the control circuit 20 can simply be discriminated for case of engine arrangement, maintenance and inspection. |
