Abstract: A solenoid includes a coil portion and a yoke having a side surface portion along an axial direction so as to accommodate the coil portion. A gap in a radial direction that communicates a radial outside of a first magnetic flux transfer portion with an outside of the solenoid is formed between an inner surface of the side surface portion and an outer surface of the coil portion, and a protrusion is formed on at least one of an inner surface and an outer surface and protrudes in the radial direction to reduce a size of at least a part of the gap.

Abstract: 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.

Abstract: A solenoid includes a coil portion and a yoke having a side surface portion along an axial direction so as to accommodate the coil portion. A gap in a radial direction that communicates a radial outside of a first magnetic flux transfer portion with an outside of the solenoid is formed between an inner surface of the side surface portion and an outer surface of the coil portion, and a protrusion is formed on at least one of an inner surface and an outer surface and protrudes in the radial direction to reduce a size of at least a part of the gap.