Abstract: 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 ? satisfy relationships of “???, ???, ?>?”, and “???>?”.

Abstract: 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 “?????”.

Abstract: An end of a first land has a step difference recessing inward of a radial direction of the first land from the edge portion. The step difference has an end point opposite to the edge portion. A throttle portion protrudes from the start point in an axial direction, and includes an outer-peripheral corner (protrusion round portion) having a curved surface protruding in the axial direction and in the radial direction. When an inlet opening starts to be slightly opened, since a hydraulic fluid is throttled when flowing through a second gate opened between a corner of a sleeve and the protrusion round portion, a rapid increasing of a flow quantity of the hydraulic fluid and an instability of a control of the hydraulic fluid can be suppressed.

Abstract: An end of a first land has a step difference recessing inward of a radial direction of the first land from the edge portion. The step difference has an end point opposite to the edge portion. A throttle portion protrudes from the start point in an axial direction, and includes an outer-peripheral corner (protrusion round portion) having a curved surface protruding in the axial direction and in the radial direction. When an inlet opening starts to be slightly opened, since a hydraulic fluid is throttled when flowing through a second gate opened between a corner of a sleeve and the protrusion round portion, a rapid increasing of a flow quantity of the hydraulic fluid and an instability of a control of the hydraulic fluid can be suppressed.

Abstract: A linear solenoid has a first magnetic pulling portion for attracting a forward end of a plunger in a forward direction. The linear solenoid further has a second magnetic pulling portion at a rear end of the solenoid. A magnetic path portion is formed at the rear end of the solenoid and composed of a constant overlapping area and a temporal overlapping area. A plunger side-gap portion is formed at a rear end of the plunger so as to face to the overlapping areas in a radial direction. A first radial gap, which is formed between the constant overlapping area and the plunger side-gap portion, is made larger than a second radial gap, which is formed between the temporal overlapping area and the plunger side-gap portion.

Abstract: In an electromagnetic hydraulic pressure control valve of an N/L type, an electromagnetic actuator provides a force to a spool, which is slidably received in a valve housing, in a valve opening direction for opening an input port of the valve housing. A return spring provides a force to the spool in the valve closing direction. A constriction is provided to constrict a flow passage cross sectional area in a fluid passage, which extends from the input port to a hydraulic servo. A negative pressure port opens in a direction generally perpendicular to a flow direction of a fluid at a location, at which a fluid velocity of the fluid is accelerated by the constriction. A negative pressure guide passage communicates between the negative pressure port and a feedback chamber defined in the valve housing.

Abstract: A linear solenoid has a first magnetic pulling portion for attracting a forward end of a plunger in a forward direction. The linear solenoid further has a second magnetic pulling portion at a rear end of the solenoid. A magnetic path portion is formed at the rear end of the solenoid and composed of a constant overlapping area and a temporal overlapping area. A plunger side-gap portion is formed at a rear end of the plunger so as to face to the overlapping areas in a radial direction. A first radial gap, which is formed between the constant overlapping area and the plunger side-gap portion, is made larger than a second radial gap, which is formed between the temporal overlapping area and the plunger side-gap portion.

Abstract: A valve apparatus is adapted to be at least partially inserted into an insertion hole of a counterpart member. The valve apparatus includes a housing and an O-ring. The housing is adapted to be inserted from an outside of the insertion hole into the insertion hole. The housing and the insertion hole define an annular gap therebetween. The O-ring seals the annular gap. The housing includes a substantially cylindrical base metallic member inserted into the insertion hole and an outer resin member. The outer resin member is fixed to the base metallic member, and at least partially defines an outer circumferential periphery of the housing. The base metallic member defines a bottom surface of a groove that supports the O-ring. The bottom surface of the groove is exposed circumferentially throughout from the outer resin member. The outer resin member defines a wall that restricts the O-ring from axially moving.

Abstract: In a linear solenoid, a plunger and a shaft axially contact with each other to transmit a drive force of the plunger to the shaft through a contact portion between the plunger and the shaft. The contact portion between the plunger and the shaft is placed between a magnetically attracting side end of the plunger and the other end of the plunger along a center axis of the plunger.

Abstract: In an electromagnetic hydraulic pressure control valve of an N/L type, an electromagnetic actuator provides a force to a spool, which is slidably received in a valve housing, in a valve opening direction for opening an input port of the valve housing. A return spring provides a force to the spool in the valve closing direction. A constriction is provided to constrict a flow passage cross sectional area in a fluid passage, which extends from the input port to a hydraulic servo. A negative pressure port opens in a direction generally perpendicular to a flow direction of a fluid at a location, at which a fluid velocity of the fluid is accelerated by the constriction. A negative pressure guide passage communicates between the negative pressure port and a feedback chamber defined in the valve housing.

Abstract: A linear solenoid is provided which works to pull a plunger to a stator magnetically. The plunger and the stator are aligned to have ends opposed to each other. The end of the stator has formed therein a recess into which the end of the plunger is insertable. The recess has an inward magnetic attraction surface formed on a peripheral edge. The plunger has an outward magnetic attraction surface formed on an outer peripheral edge of the end thereof which faces the inward magnetic attraction surface through a magnetic gap. The inward and outward magnetic attraction surfaces have greater areas defining the magnetic gap, thereby ensuring a greater amount of magnetic attraction pulling the plunger to the stator upon energization of a coil. The recess may alternatively be formed in the end of the plunger.

Abstract: A valve apparatus is adapted to be at least partially inserted into an insertion hole of a counterpart member. The valve apparatus includes a housing and an O-ring. The housing is adapted to be inserted from an outside of the insertion hole into the insertion hole. The housing and the insertion hole define an annular gap therebetween. The O-ring seals the annular gap. The housing includes a base metallic member and an outer resin member. The base metallic member is substantially cylindrical, and is inserted into the insertion hole. The outer resin member is fixed to the base metallic member. The outer resin member at least partially defines an outer circumferential periphery of the housing. The base metallic member defines a bottom surface of a groove that supports the O-ring. The bottom surface of the groove is exposed circumferentially throughout from the outer resin member. The outer resin member defines a resin wall that restricts the O-ring from axially moving.

Abstract: A linear solenoid is provided which works to pull a plunger to a stator magnetically. The plunger and the stator are aligned to have ends opposed to each other. The end of the stator has formed therein a recess into which the end of the plunger is insertable. The recess has an inward magnetic attraction surface formed on a peripheral edge. The plunger has an outward magnetic attraction surface formed on an outer peripheral edge of the end thereof which faces the inward magnetic attraction surface through a magnetic gap. The inward and outward magnetic attraction surfaces have greater areas defining the magnetic gap, thereby ensuring a greater amount of magnetic attraction pulling the plunger to the stator upon energization of a coil. The recess may alternatively be formed in the end of the plunger.