Abstract: An armature manufacturing method includes preparing a core member that includes a rotation shaft at a central portion and that is formed with plural teeth in a radiating shape centered on the rotation shaft; and winding winding wires onto slots between the plural teeth so as to form plural types of winding coil sections, each with a different winding wire diameter.

Abstract: An armature manufacturing method includes preparing a core member that includes a rotation shaft at a central portion and that is formed with plural teeth in a radiating shape centered on the rotation shaft; and winding winding wires onto slots between the plural teeth so as to form plural types of winding coil sections, each with a different winding wire diameter.

Abstract: A fuel injection valve (1) configured such that control of the escape of high-pressure fuel inside a control chamber (45) to a fuel low-pressure portion is conducted by an electromagnetic valve (5) for controlling fuel injection configured such that a lift operation of an armature plate (51) is controlled by an electromagnetic solenoid (68) and an armature stopper (67) incorporated inside a fixed sleeve (61), wherein a gap (G3) is disposed between a fixed core (63) and the armature stopper (67), through holes (67B) are disposed in the armature stopper (67), and drain fuel flows to the fuel low-pressure portion via the gap (G3) and the through holes (67B) when the electromagnetic valve (5) is powered. As a result, the lift amount of the armature plate (51) can be prevented from changing as a result of debris or the like included in the drain fuel becoming caught between the armature plate (51) and the armature stopper (67).

Abstract: In a fuel injector (1) configured so that fuel injection is controlled by a solenoid valve (4), the solenoid valve (4) comprises an electromagnet (43), an armature bolt (41) that has a ball (42) and a plate member (41A) attached thereto and is spring-biased in the valve closing direction by a spring member (48), a stopper member (49) that limits movement of the plate member (41A) in order to limit the maximum stroke of the ball (42) and an armature plate (44) through which the armature bolt (41) passes and which collaborates with the solenoid valve (4), the contact area (S2) between the armature plate (44) and the plate member (41A) being made larger than the contact area (S1) between the plate member (41A) and the stopper member (49).

Abstract: In a fuel injector (1) configured so that fuel injection is controlled by a solenoid valve (4), the solenoid valve (4) comprises an electromagnet (43), an armature bolt (41) that has a ball (42) and a plate member (41A) attached thereto and is spring-biased in the valve closing direction by a spring member (48), a stopper member (49) that limits movement of the plate member (41A) in order to limit the maximum stroke of the ball (42) and an armature plate (44) through which the armature bolt (41) passes and which collaborates with the solenoid valve (4), the contact area (S2) between the armature plate (44) and the plate member (41A) being made larger than the contact area (S1) between the plate member (41A) and the stopper member (49).