Abstract: An electromagnetic fuel injection valve wherein a movable core disposed opposing an attracting face of a fixed core is slidably fitted onto a stem forming a valve body together with a valve part operating in cooperation with a valve seat, a valve-open side stopper is fixed to the stem so that, by making the movable core, that is attracted to the face when energizing a coil, abut against this stopper, the body is operated to open, and a valve-closed side stopper is fixed to the stem further on the seat side than the other stopper so as to restrict a stroke of the movable core between these stoppers. At least an end part of one of the valve-closed side stopper and the movable core, the end part being on a side of the other one thereof, is formed to gradually decreasing its cross-sectional area in going toward the other one.

Abstract: An electromagnetic fuel injection valve wherein a movable core disposed opposing an attracting face of a fixed core is slidably fitted onto a stem forming a valve body together with a valve part operating in cooperation with a valve seat, a valve-open side stopper is fixed to the stem so that, by making the movable core, that is attracted to the face when energizing a coil, abut against this stopper, the body is operated to open, and a valve-closed side stopper is fixed to the stem further on the seat side than the other stopper so as to restrict a stroke of the movable core between these stoppers. At least an end part of one of the valve-closed side stopper and the movable core, the end part being on a side of the other one thereof, is formed to gradually decreasing its cross-sectional area in going toward the other one.

Abstract: A control device includes a difference calculating unit configured to generate a difference waveform composed of the difference between a normal operation waveform, which is a voltage waveform of the fuel injection valve at a time that the fuel injection valve is operating, and a non-operation waveform, which is a voltage waveform of the fuel injection valve at a time that the fuel injection valve is not operating, a derivative calculating unit configured to generate a differentiated waveform obtained by differentiating the difference waveform, and an operating state determining unit configured to determine the operating state of the fuel injection valve based on the differentiated waveform.

Abstract: In a vibration insulating structure of a fuel injection valve in an internal combustion engine, a vibration insulating device installed between an annular step portion of a valve installation hole provided in a cylinder head and an outer peripheral step portion of the valve fitted in the hole is formed from a ring laminated body including an upper ring engaged with the outer peripheral step portion, and at least two vibration insulating rings clamped between the upper ring and the annular step portion and superposed on each other. Multiple dents and projections each having a fine and uneven shape are formed on at least an abutment surface of each of the vibration insulating rings which abuts against an opposed one of the vibration insulating rings. Accordingly, such device can be easily obtained from a simple structure and inhibit vibration of the valve effectively, reducing vibration noise and manufacturing cost.