Abstract: A solenoid has a coil, a yoke including a side surface portion along an axial direction and a bottom portion, a columnar plunger configured to slide in an axial direction, a stator core, and a second magnetic flux transfer portion. The stator core includes a magnetic attraction core configured to attract magnetically the plunger by a magnetic force generated by a coil, and a sliding core having a cylindrical core portion, a first magnetic flux transfer portion, and a magnetic flux passage suppressing portion configured to suppress passage of magnetic flux between the sliding core and the magnetic attraction core. The second magnetic flux transfer portion transfers the magnetic flux between the magnetic attraction core and the side surface portion. A first breathing groove extending in the axial direction in communication with the outside is formed on an inner peripheral surface of the yoke.

Abstract: A spool valve includes a valve housing, a spool and radial damper device. The valve housing has a shaft bore. The spool is slidably supported within the shaft bore in a longitudinal direction, and the spool has a first diameter portion and a second diameter portion. The radial damper device has a radial damper chamber and a radial chamber restrictor. The radial damper chamber is defined by a diameter difference between the first diameter portion and the second diameter portion. The radial chamber restrictor provides communication between the radial damper chamber and an adjacent chamber disposed adjacent to the radial damper chamber in the longitudinal direction.

Abstract: In a valve body, an input chamber is located between a small diameter slide hole, which slidably supports a small diameter portion of a slidable valve, and a large diameter slide hole, which slidably supports a large diameter portion of the slidable valve, at a location that is closer to the small diameter slide hole than to the large diameter slide hole. An output chamber is located between the small diameter slide hole and the large diameter slide hole at a location that is closer to the large diameter slide hole than to the small diameter slide hole. A valve opening communicates between the input chamber and the output chamber and is opened and closed in response to a slide position of the slidable valve. A pilot chamber exerts a pilot pressure to urge the slidable valve in a valve closing direction toward the valve opening.

Abstract: In a valve body, an input chamber is located between a small diameter slide hole, which slidably supports a small diameter portion of a slidable valve, and a large diameter slide hole, which slidably supports a large diameter portion of the slidable valve, at a location that is closer to the small diameter slide hole than to the large diameter slide hole. An output chamber is located between the small diameter slide hole and the large diameter slide hole at a location that is closer to the large diameter slide hole than to the small diameter slide hole. A valve opening communicates between the input chamber and the output chamber and is opened and closed in response to a slide position of the slidable valve. A pilot chamber exerts a pilot pressure to urge the slidable valve in a valve closing direction toward the valve opening.

Abstract: A spool valve includes a valve housing, a spool and radial damper device. The valve housing has a shaft bore. The spool is slidably supported within the shaft bore in a longitudinal direction, and the spool has a first diameter portion and a second diameter portion. The radial damper device has a radial damper chamber and a radial chamber restrictor. The radial damper chamber is defined by a diameter difference between the first diameter portion and the second diameter portion. The radial chamber restrictor provides communication between the radial damper chamber and an adjacent chamber disposed adjacent to the radial damper chamber in the longitudinal direction.