Abstract: A controller for an electromagnetic actuator comprises a pair of springs acting on opposite directions, and an armature connected to the springs. The armature is held in a neutral position given by the springs when the armature is not activated. The actuator also comprises a pair of electromagnets for driving the armature between two end positions. In response to a release of the armature held in one of the end positions, the controller applies brake to the armature according to a load condition of the armature. In high-load conditions, the valve can surely be opened without additional electric power. In low-load conditions, the armature is prevented from colliding with a yoke of the electromagnet. The application of brake includes over-excitation operation, flywheel operation and suspension of power supply. In the over-excitation operation, voltage is applied to the electromagnet corresponding to one of the end positions from which the armature is released for a first period.

Abstract: There is provided a solenoid-type valve actuator for an internal combustion engine, having an inexpensive and single construction which is capable of maintaining stability of operation of a valve and reducing sliding resistance to the valve at the same time, thereby achieving improved response of the valve and reduced power consumption of electromagnets. The solenoid-type valve actuator electromagnetically opens and closes a valve. Two electromagnets are arranged in a manner opposed to each other with a space therebetween. An armature is arranged between the two electromagnets, for reciprocating motion by energization and deenergization of the two electromagnets. Two shafts project from respective opposite sides of the armature and extend through the two electromagnets, respectively, one of the shafts being connected to the valve.

Abstract: A controller for an electromagnetic actuator comprises a pair of spring acting in opposite directions, and an armature coupled to a mechanical element. The armature is connected to the springs and held in a neutral position given by the springs when the actuator is not activated. The actuator includes a pair of electromagnets for driving the armature between two end positions. The controller includes voltage application means for applying voltage to an electromagnet providing one end position for a first predetermined period so as to attract the armature to the end position. The controller also includes a peak current detector for detecting the peak of current flowing through the electromagnet in the first predetermined period. In accordance with the peak value, a decision means decides the application period of voltage that is to be applied to the electromagnet after the first application period has elapsed.

Abstract: A controller for an electromagnetic actuator is provided that enables detection of a minute movement of the armature leaving the seating position and carries out pullback operation responsive to such detection. The electromagnetic actuator has a pair of springs acting on opposite directions, and an armature coupled to a mechanical element such as a exhaust/intake valve of an automobile engine. The armature is held in a neutral position given by the springs when the actuator is not activated. The actuator includes a pair of electromagnets for driving the armature between two end positions. The controller having current supplying means for supplying holding current to the electromagnet corresponding to one of the end positions when holding the armature in said one of the end positions.

Abstract: A controller for an electromagnetic actuator comprises a pair of spring acting in opposite directions, and an armature coupled to a mechanical element. The armature is connected to the springs and held in a neutral position given by the springs when the actuator is not activated. The actuator includes a pair of electromagnets for driving the armature between two end positions. The controller includes voltage application means for applying voltage to an electromagnet providing one end position for a first predetermined period so as to attract the armature to the end position. The controller also includes a peak current detector for detecting the peak of current flowing through the electromagnet in the first predetermined period. In accordance with the peak value, a decision means decides the application period of voltage that is to be applied to the electromagnet after the first application period has elapsed.

Abstract: A controller for an electromagnetic actuator comprises a pair of springs acting on opposite directions, and an armature connected to the springs. The armature is held in a neutral position given by the springs when the armature is not activated. The actuator also comprises a pair of electromagnets for driving the armature between two end positions. In response to a release of the armature held in one of the end positions, the controller applies brake to the armature according to a load condition of the armature. In high-load conditions, the valve can surely be opened without additional electric power. In low-load conditions, the armature is prevented from colliding with a yoke of the electromagnet. The application of brake includes over-excitation operation, flywheel operation and suspension of power supply. In the over-excitation operation, voltage is applied to the electromagnet corresponding to one of the end positions from which the armature is released for a first period.

Abstract: A controller for an electromagnetic actuator is provided that enables detection of a minute movement of the armature leaving the seating position and carries out pullback operation responsive to such detection. The electromagnetic actuator has a pair of springs acting on opposite directions, and an armature coupled to a mechanical element such as a exhaust/intake valve of an automobile engine. The armature is held in a neutral position given by the springs when the actuator is not activated. The actuator includes a pair of electromagnets for driving the armature between two end positions. The controller comprises current supplying means for supplying holding current to the electromagnet corresponding to one of the end positions when holding the armature in said one of the end positions.

Abstract: There is provided a solenoid-type valve actuator for an internal combustion engine, having an inexpensive and single construction which is capable of maintaining stability of operation of a valve and reducing sliding resistance to the valve at the same time, thereby achieving improved response of the valve and reduced power consumption of electromagnets. The solenoid-type valve actuator electromagnetically opens and closes a valve. Two electromagnets are arranged in a manner opposed to each other with a space therebetween. An armature is arranged between the two electromagnets, for reciprocating motion by energization and deenergization of the two electromagnets. Two shafts project from respective opposite sides of the armature and extend through the two electromagnets, respectively, one of the shafts being connected to the valve.