A solenoid includes a molded coil having a hole at the center of a coil of a plurality of turns, a solenoid body having a case covering the outer perimeter of the molded coil, a movable plunger inserted in the hole, and a magnetic attraction portion disposed in a direction in which the plunger is moved and attracted by magnetic force produced by the coil, an annular plate adjacent to the coil of the molded coil opposite to the solenoid body, and a sleeve facing the magnetic attraction portion via an air gap and supporting one end of a rod connected to the plunger, in which a magnetic circuit L is formed through the magnetic attraction portion, the case, the sleeve, and the plunger, and back to the magnetic attraction portion, and the plunger has at least one outer edge extension formed by an outer edge portion extended axially.

An electromagnetic actuator includes an electromagnetic coil, a yoke serving as a magnetic path of a magnetic flux of the electromagnetic coil, an armature configured to move in an axial direction while being attracted by the yoke by energization of the electromagnetic coil, and a housing that houses the armature. The armature and the housing are coupled to each other by an engagement structure in which protrusions provided on one of the members engage with engagement grooves formed in the other one of the members. At least a part of the engagement groove is inclined with respect to the axial direction. When the armature moves while being attracted by the yoke, the protrusions of the armature slide along the engagement grooves of the housing, and the armature turns relative to the housing along the inclination of the engagement grooves.

In a diameter-increasing portion, which includes first to third angle segments, an A-point is defined as an intersection between a radially outer surface of a thin wall portion and the first angle segment, and a B-point is defined as an intersection between a radially outer surface of a thick wall portion and the third angle segment. Radially outer surfaces of the first to third angle segments are located on a radially outer side of a reference conical surface, which is formed by rotating a straight line connecting between the A-point and the B-point about a central axis, throughout an entire range from the A-point to the B-point. A first angle , a second angle , a third angle and a reference angle e satisfy relationships of , , , and .

A shaft outputs a thrust force in an axial direction by using a magnetic flux caused by an electric current flowing through a coil. A housing is made of resin and retains the shaft. The housing has a base portion having an outer circumferential surface, which is configured to be entirely in contact tightly with a sealing member. The housing further has a distal portion having an outer circumferential surface defining a depression. The outer circumferential surfaces of the base portion and the distal portion are substantially equal in diameter and are formed continuously.

A solenoid includes a coil portion, a yoke having a cylindrical portion and a bottom portion and accommodating the coil portion, a plunger configured to slide in an axial direction, a stator core. The stator core has a magnetic attraction core, and a sliding core having a cylindrical core portion, a first magnetic flux transfer portion configured to transfer a flux between the yoke and the core portion, and a magnetic flux passage suppressing portion configured to suppress passage of magnetic flux between the sliding core and the magnetic attraction core. A second magnetic flux transfer portion is arranged on a radial outside of the magnetic attraction core end portion and transfers the magnetic flux between the magnetic attraction core and the cylindrical portion. The first magnetic flux transfer portion is gap-fitted in the cylindrical portion.

Electromagnetic solenoid has movable core having end surface that is formed between inner circumferential surface and outer circumferential surface of movable core; and fixed core having end surface that is formed between inner circumferential surface and outer circumferential surface of fixed core and faces the end surface of movable core. Ring-shaped protruding portion is formed at least either one of the end surface of the movable core or the end surface of the fixed core. Protruding portion is provided at a position that is shifted to a radially inner circumferential side of the end surface. A length between apex and inner circumferential edge of protruding portion is shorter than a length between the apex and an outer circumferential edge of protruding portion.

A solenoid actuator is provided having an armature assembly with a separate joined shunt side bearing consisting of a non-magnetic or slightly magnetic material. The material of the shunt side bearing prevents significant amounts of magnetic flux transferring through the lower bearing area of the armature assembly in the radial direction.

An electromagnetic positioning device (1), having a stationary spool unit (9), having a moveably guided anchor (2), which forms a positioning section (14) and which can be axially displaced along a displacement axis (V) in response to supplying the spool unit (9) with current, as well as having a one-part cup-shaped yoke-core element (3), which receives the anchor (2) and which includes a core section (5) as well as a yoke section (6) and which has a yoke-core bottom (4) extending perpendicular to the displacement axis (V) and a yoke-core sheath extending perpendicular to the yoke-core bottom (4) along the displacement axis (V), a longitudinally cut transition area (8) reduced in thickness and arranged between the core section (5) and the yoke section (6) being realized in the yoke-core sheath. It is intended that a guide pin (17) for the anchor (2) is fixed, preferably pressed in, in a, preferably centric, guide pin recess (18) in the yoke-core bottom (4) and protrudes axially into a, preferably centric, guide opening (13) of the anchor (2) and can be displaced relative to the anchor (2) during its displacement movement.

In a solenoid valve, a length in an axial direction from a stator core end surface to a bottom portion of a yoke is equal to or longer than a total length in the axial direction of a shaft and a plunger. When the shaft and the plunger move to the bottom portion side, the stator core end surface and the spool end surface come into contact with each other so as to restrict a movement of a spool. A groove portion, which communicates a space formed by the stator core, the spool, and the shaft with an accommodating portion when the stator core end surface and the spool end surface come into contact with each other, is formed on at least one of the stator core end surface and the spool end surface, and a communication hole communicates an inside and an outside of the accommodating portion.

Presented are a single coil apparatus and a method of forming. An exemplary apparatus includes solenoid assembly. The solenoid assembly includes a core tube extending along a longitudinal axis. The solenoid assembly further includes a first magnet and a second magnet located outside the core tube, the first magnet spaced along the longitudinal axis from the second magnet, and an excitation coil disposed radially outward of the first magnet and the second magnet.