Abstract: A coil is located radially outside of a pipe. An inner connector is located radially inside of the pipe. A moving core is located radially inside of the pipe and opposed to the inner connector. A housing surrounds both an outer circumferential periphery of the coil and one axial end of the coil. A cover surrounds an other axial end of the coil. An outer connector leads fuel into the pipe. The pipe and the cover are integrally formed and one single component as a with-cover pipe member. The inner connector and the outer connector are integrally formed and an other single component as a connector member. The connector member is partially inserted in the axial direction radially inside the pipe of the with-cover pipe member.

Abstract: A coil is located radially outside of a cylindrical pipe and configured to generate a magnetic field when being energized. A stationary core is located radially inside of the pipe. A moving core is located radially inside of the pipe and opposed to the stationary core. The moving core is configured to be attracted to the stationary core by magnetic attraction force generated therebetween. A valve element is axially movable together with the moving core to open and close a nozzle hole for injecting fuel. A housing surrounds both an outer circumferential periphery of the coil and one end of the coil in an axial direction. A cover surrounding an other end of the coil in the axial direction. The pipe and the housing are integrally formed and one component.

Abstract: A coil is located radially outside of a pipe. An inner connector is located radially inside of the pipe. A moving core is located radially inside of the pipe and opposed to the inner connector. A housing surrounds both an outer circumferential periphery of the coil and one axial end of the coil. A cover surrounds an other axial end of the coil. An outer connector leads fuel into the pipe. The pipe and the cover are integrally formed and one single component as a with-cover pipe member. The inner connector and the outer connector are integrally formed and an other single component as a connector member. The connector member is partially inserted in the axial direction radially inside the pipe of the with-cover pipe member.

Abstract: An electromagnetic drive has a sliding portion and a stator, the stator forming a magnetic circuit in combination with the sliding portion. The stator has an accommodating portion for supporting the sliding portion so the sliding portion can reciprocate inside the accommodating portion. A magnetic attractive force is generated by a coil to attract the sliding portion in one of the reciprocating directions. The coil generates a magnetic attractive force when energized such that either one or both of at least an outer peripheral wall of the sliding portion and at least an inner peripheral wall of said accommodating portion forms a magnetic portion made of nickel phosphide. The phosphorus content of said magnetic portion is set within a range of 5% to 15% in mass percentage.

Abstract: An electromagnetic actuator has a movable core, a housing that holds the movable core so that the core may freely reciprocate, and an attractive part that applies a magnetic force to pull the movable core in one of the reciprocating directions. The electromagnetic actuator further has a stator that constitutes a magnetic circuit along with the movable core. At least one of the sliding faces of the housing and the movable core in contact with each other is subjected to gas soft nitriding, salt-bath soft nitriding, sulfo-nitriding, or nitriding treatment. The surface roughness of such a nitrided face is controlled to be within a prescribed range, so that the wear of the sliding faces of the movable core and the housing can be reduced.

Abstract: In an electromagnetic valve device having a valve housing, a valve member slidably accommodated in the valve housing to control oil communications among ports formed in the valve housing, a spring biasing the valve member, a stopper retaining the spring and an electromagnetic drive member for generating, when energized, a driving force to displace the valve member against a biasing force of the spring, the valve housing is provided at an axial end with a small diameter portion whose wall thickness is thinner and the stopper is press fitted substantially to an inner circumferential surface of the small diameter portion so that radially outward resilient deformation of the small diameter portion is larger than radially inward resilient deformation of the stopper.

Abstract: An electromagnetic drive has a sliding portion and a stator, the stator forming a magnetic circuit in combination with the sliding portion. The stator has an accommodating portion for supporting the sliding portion so the sliding portion can reciprocate inside the accommodating portion. A magnetic attractive force is generated by a coil to attract the sliding portion in one of the reciprocating directions. The coil generates a magnetic attractive force when energized such that either one or both of at least an outer peripheral wall of the sliding portion and at least an inner peripheral wall of said accommodating portion forms a magnetic portion made of nickel phosphide. The phosphorus content of said magnetic portion is set within a range of 5% to 15% in mass percentage.

Abstract: A solenoid valve device controls a driving force generated by a linear solenoid (electromagnetic driving portion), for pressing a spool away from the linear solenoid by controlling a current supplied to a coil, and ultimately adjusting an oil pressure flowing from an outlet port. As current supplied to the coil increases, the outlet port oil pressure decreases. An outside diameter of a tube portion of a valve housing is equal to or larger than an outside diameter r1 of the linear solenoid (r2≧r1) and a flange of the valve housing, permitting the entire solenoid valve device to be disposed within a cylindrical reception hole provided in a hydraulic control apparatus body of an automatic gear, for example. A method of manufacturing the solenoid valve device is also disclosed.

Abstract: An electromagnetic actuator has a movable core, a housing that holds the movable core so that the core may freely reciprocate, and an attractive part that applies a magnetic force to pull the movable core in one of the reciprocating directions. The electromagnetic actuator further has a stator that constitutes a magnetic circuit along with the movable core. At least one of the sliding faces of the housing and the movable core in contact with each other is subjected to gas soft nitriding, salt-bath soft nitriding, sulfo-nitriding, or nitriding treatment. The surface roughness of such a nitrided face is controlled to be within a prescribed range, so that the wear of the sliding faces of the movable core and the housing can be reduced.

Abstract: A stator core integrally includes a container portion and an attracting portion. The container portion contains and supports a plunger to allow it to reciprocate thereinside. The attracting portion magnetically attracts the plunger. The plunger includes a moving core made of magnetic material, and a nonmagnetic cup fit to the moving core. The cup integrally includes a cylindrical wall covering the outside wall of the moving core, and a bottom covering the lower end of the moving core. Air gap between the moving core and the container portion can be reduced by making the thickness of the cup as thin as possible. Thus, an attracting force for attracting the plunger without increasing winding number of the coil.

Abstract: In an electromagnetic valve device having a valve housing, a valve member slidably accommodated in the valve housing to control oil communications among ports formed in the valve housing, a spring biasing the valve member, a stopper retaining the spring and an electromagnetic drive member for generating, when energized, a driving force to displace the valve member against a biasing force of the spring, the valve housing is provided at an axial end with a small diameter portion whose wall thickness is thinner and the stopper is press fitted substantially to an inner circumferential surface of the small diameter portion so that radially outward resilient deformation of the small diameter portion is larger than radially inward resilient deformation of the stopper.

Abstract: In a solenoid portion of a solenoid valve, a fixed core for axially attracting a plunger due to magnetic force generated by a magnetic coil is divided into two. One is a cylindrical yoke having an opening at an axial end and a bottom at the other axial end. The other one is a cylindrical stator core having a flange protruding radially outwardly at an axial end thereof. The bottom of the yoke is provided with a thick body portion having a center recess. The inner surface of the opening of the yoke is fitted to an outer surface of the flange and the inner surface of the recess of the thick body portion is fitted to an outer surface of the stator core. Accordingly, constructions of molding dies for manufacturing the yoke and the stator core are simple. Further, only limited surfaces of the yoke and the stator core, which are fitted to each other, need accurate dimensions so that magnetic gap is minimized.

Abstract: In a solenoid portion of a solenoid valve, a fixed core for axially attracting a plunger due to magnetic force generated by a magnetic coil is divided into two. One is a cylindrical yoke having an opening at an axial end and a bottom at the other axial end. The other one is a cylindrical stator core having a flange protruding radially outwardly at an axial end thereof. The bottom of the yoke is provided with a thick body portion having a center recess. The inner surface of the opening of the yoke is fitted to an outer surface of the flange and the inner surface of the recess of the thick body portion is fitted to an outer surface of the stator core. Accordingly, constructions of molding dies for manufacturing the yoke and the stator core are simple. Further, only limited surfaces of the yoke and the stator core, which are fitted to each other, need accurate dimensions so that magnetic gap is minimized.

Abstract: A solenoid valve device controls a driving force generated by a linear solenoid (electromagnetic driving portion), for pressing a spool away from the linear solenoid by controlling a current supplied to a coil, and ultimately adjusting an oil pressure flowing from an outlet port. As current supplied to the coil increases, the outlet port oil pressure decreases. An outside diameter of a tube portion of a valve housing is equal to or larger than an outside diameter r1 of the linear solenoid (r2≧r1) and a flange of the valve housing, permitting the entire solenoid valve device to be disposed within a cylindrical reception hole provided in a hydraulic control apparatus body of an automatic gear, for example. A method of manufacturing the solenoid valve device is also disclosed.

Abstract: A stator core integrally includes a container portion and an attracting portion. The container portion contains and supports a plunger to allow it to reciprocate thereinside. The attracting portion magnetically attracts the plunger. The plunger includes a moving core made of magnetic material, and a nonmagnetic cup fit to the moving core. The cup integrally includes a cylindrical wall covering the outside wall of the moving core, and a bottom covering the lower end of the moving core. Air gap between the moving core and the container portion can be reduced by making the thickness of the cup as thin as possible. Thus, an attracting force for attracting the plunger without increasing winding number of the coil.