Abstract: To prevent the sticking of the valve body of an electromagnetic valve under idling conditions or under non-injection conditions in a control device of common rail fuel injection system of an engine wherein the fuel supplied from a feed pump (6) is pressurized to high pressure by a high-pressure pump (3) and the quantity of fuel supply to this high-pressure pump (3) is adjusted by an electromagnetic valve (7) whose degree of opening is controlled in accordance with a duty signal, the control frequency of the duty signal is altered to a lower frequency (&lgr;l) when an operating condition such that the degree of opening of the electromagnetic valve (7) is constant is detected. In this way, the energy or amplitude per current wave flowing in the electromagnetic solenoid (39) can be made larger, so making it possible to produce minute vibrations of the valve body (41). Sticking of the valve body (41) can thereby be prevented.

Abstract: To prevent the sticking of the valve body of an electromagnetic valve under idling conditions or under non-injection conditions in a control device of common rail fuel injection system of an engine wherein the fuel supplied from a feed pump (6) is pressurized to high pressure by a high-pressure pump (3) and the quantity of fuel supply to this high-pressure pump (3) is adjusted by an electromagnetic valve (7) whose degree of opening is controlled in accordance with a duty signal, the control frequency of the duty signal is altered to a lower frequency (&lgr;l) when an operating condition such that the degree of opening of the electromagnetic valve (7) is constant is detected. In this way, the energy or amplitude per current wave flowing in the electromagnetic solenoid (39) can be made larger, so making it possible to produce minute vibrations of the valve body (41). Sticking of the valve body (41) can thereby be prevented.