Abstract: An electromagnetic actuator 1 includes divisional cores (5a1 and 5a2), divisional cores (5b1 and 5b2) , a first coil unit (3A), a second coil unit (3B), a first movable unit (11a), a second movable unit (11b), and a casing (2). The casing (2) includes a magnetic material and surrounds the first coil unit (3A) and the second coil unit (3B) integrally.

Abstract: A sensor core (8) is arranged in a plane (P1), which is positioned on sides of opposite ends of plungers (5a, 5b) from bosses (6a, 6b), and which is perpendicular to a direction of movement of the plungers (5a, 5b). A magnetic sensor (9) is arranged at a position in the plane (P1), the position being apart from a magnetic path (A3) of a leakage flux of a magnetic circuit (A).

Abstract: The magnetic resistance of a magnetic path that passes through a coil (6) is increased by magnetically dividing a stator core into a plurality of divided cores (4, 5) in such a manner that the magnetic flux of a permanent magnet (7) flows through the magnetic path when a projection (82) of a plunger (8) magnetically connects the divided cores (4, 5), hence the magnetic resistance of the magnetic path that passes through the coil (6) rapidly changes due to a positional relationship between a gap between the divided cores (4, 5) and the plunger (8), and the magnetic flux that flows through the magnetic path rapidly changes, and moreover a large back electromotive force is produced.

Abstract: An electromagnetic actuator (1) includes sensor magnets (21a, 21b) disposed correspondingly to plungers (11a, 11b), respectively. The electromagnetic actuator (1) further includes a sensor core (22) made of a magnetic material and disposed in a position through which magnetic fluxes from the plurality of sensor magnets (21a, 21b) can flow, and a magnetic sensor (23) that is disposed in a part of the sensor core (22) through which the magnetic fluxes of the plurality of sensor magnets (21a, 21b) can flow in common, and that detects the magnetic flux, which varies in accordance with respective positions of the plurality of plungers (11a, 11b).

Abstract: A sensor core (8) is arranged in a plane (P1), which is positioned on sides of opposite ends of plungers (5a, 5b) from bosses (6a, 6b), and which is perpendicular to a direction of movement of the plungers (5a, 5b). A magnetic sensor (9) is arranged at a position in the plane (P1), the position being apart from a magnetic path (A3) of a leakage flux of a magnetic circuit (A).

Abstract: An electromagnetic actuator (1) includes sensor magnets (21a, 21b) disposed correspondingly to plungers (11a, 11b), respectively. The electromagnetic actuator (1) further includes a sensor core (22) made of a magnetic material and disposed in a position through which magnetic fluxes from the plurality of sensor magnets (21a, 21b) can flow, and a magnetic sensor (23) that is disposed in a part of the sensor core (22) through which the magnetic fluxes of the plurality of sensor magnets (21a, 21b) can flow in common, and that detects the magnetic flux, which varies in accordance with respective positions of the plurality of plungers (11a, 11b).

Abstract: The magnetic resistance of a magnetic path that passes through a coil (6) is increased by magnetically dividing a stator core into a plurality of divided cores (4, 5) in such a manner that the magnetic flux of a permanent magnet (7) flows through the magnetic path when a projection (82) of a plunger (8) magnetically connects the divided cores (4, 5), hence the magnetic resistance of the magnetic path that passes through the coil (6) rapidly changes due to a positional relationship between a gap between the divided cores (4, 5) and the plunger (8), and the magnetic flux that flows through the magnetic path rapidly changes, and moreover a large back electromotive force is produced.