Solenoid operated hydraulic control valve

Claim 2

A spool valve comprising: a valve spool including a central recess region of predetermined length and substantially constant cross section along said recess region length; a valve body slidably fitted over said valve spool, including a supply port, a discharge port separated from said supply port by a port separation length less than said recess region length, said supply port and said discharge port having substantially identical areas along said valve body; means for biasing said valve spool to a normally closed position with said valve spool recess region positioned beyond said supply port toward said discharge port to block fluid flow through said valve recess region from said supply port; and means for displacing said valve spool to an open position with said valve spool recess region displaced midway between said supply port and said discharge port to allow flow through said valve recess region from said supply port to said discharge port without flow induced valve spool force imbalance.

Claim 3

The spool valve recited in claim 1, wherein said means for biasing includes a compression type spring penetrating said valve body from a spring end of said valve body, said spring being axially aligned with said valve spool.

Claim 4

The spool valve recited in claim 2, wherein said means for displacing includes a plunger pin penetrating said valve body from a plunger pin end of said valve body opposite said valve body spring end.

Claim 5

The spool valve recited in claim 3, wherein said supply port includes an annular supply channel in said valve body surrounding said valve spool, and said discharge port includes an annular discharge channel in said valve body surrounding said valve spool, said supply channel and said discharge channel having substantially equal lengths along said valve body.

Claim 6

The spool recited in claim 4, wherein said valve body comprises a cylindrical cavity located in a spool valve housing.

Claim 7

The spool valve recited in claim 5, further comprising a valve body plunger end wall for retaining said valve spool in said normally closed position.

Claim 8

A spool valve comprising: a valve spool including a central recess region of predetermined length and substantially constant cross section along said region length; a valve body having a cylindrical cavity in a spool valve housing and slidably fitted over said valve spool, including a supply port, a discharge port separated from said recess region length, said supply port and said discharge port having substantially identical areas along said valve body; means for biasing said valve spool to a normally closed position with said valve spool recess region positioned beyond said supply port toward said discharge port to block fluid flow through said valve recess region from said supply port, wherein said means for biasing includes a compression type spring penetrating said valve body from a spring end of said valve body, said spring being axially aligned with said valve spool; means for displacing said valve spool to an open position with said valve spool recess region displaced midway between said supply port and said discharge port to allow flow through said valve recess region from said supply port to said discharge port without flow induced valve spool force imbalance, wherein said means for displacing includes a plunger pin penetrating said valve body from a plunger pin end of said valve body opposite said valve body spring end; a valve body plunger end wall for retaining said valve spool in said normally closed position; wherein said supply port includes an annular supply channel in said valve body surrounding said valve spool, and said discharge port includes an annular discharge channel in said valve body surrounding said valve spool, said supply channel and said discharge channel having substantially equal lengths along said valve body; and wherein said plunger pin penetrates said valve body plunger end wall.

Claim 9

A spool valve comprising: a valve spool including a central recess region of predetermined length and substantially constant cross section along said region length; a valve body having a cylindrical cavity in a spool valve housing and slidably fitted over said valve spool, including a supply port, a discharge port separated from said recess region length, said supply port and said discharge port having substantially identical areas along said valve body; means for biasing said valve spool to a normally closed position with said valve spool recess region positioned beyond said supply port toward said discharge port to block fluid flow through said valve recess region from said supply port, wherein said means for biasing includes a compression type spring penetrating said valve body from a spring end of said valve body, said spring being axially aligned with said valve spool; means for displacing said valve spool to an open position with said valve spool recess region displaced midway between said supply port and said discharge port to allow flow through said valve recess region from said supply port to said discharge port without flow induced valve spool force imbalance, wherein said means for displacing includes a plunger pin penetrating said valve body from a plunger pin end of said valve body opposite said valve body spring end; a valve body plunger end wall for retaining said valve spool in said normally closed position; wherein said supply port includes an annular supply channel in said valve body surrounding said valve spool, and said discharge port includes an annular discharge channel in said valve body surrounding said valve spool, said supply channel and said discharge channel having substantially equal lengths along said valve body; and wherein said plunger pin penetrates said valve body plunger end wall.

Claim 10

The spool valve recited in claim 7, further comprising a valve body spring end wall for retaining said spring.

Claim 11

The spool valve recited in claim 8, further comprising a solenoid operator coupled to said plunger pin for controlling said plunger pin penetration into said valve body.

Claim 12

The spool valve recited in claim 9, wherein said plunger pin is coupled to an armature of said solenoid operator and said valve body plunger end wall includes a stator of said solenoid operator.

Claim 13

The spool valve recited in claim 10, wherein said plunger pin penetrates a central pole piece of said solenoid operator stator.

Claim 14

The spool valve recited in claim 11, wherein said solenoid coil for said solenoid operator is wound around said stator central pole piece.

Claim 15

The spool valve recited in claim 12, wherein a magnetic field produced by said solenoid coil controls said plunger pin penetration into said valve body.

Claim 16

The spool valve recited in claim 13, wherein said armature is disc shaped, said plunger pin is coupled to the radial axis of said armature, and said solenoid magnetic field circulates through the circumferential area of said armature from said stator.

Claim 17

The spool valve recited in claim 14, wherein said plunger pin slides through said stator central pole piece along the axis of said stator central pole piece.

Claim 18

The spool valve recited in claim 15, wherein said plunger pin aligns said armature within said stator.

Claim 19

A solenoid operated spool valve comprising: a valve spool having a spool axis including a central recess region of predetermined length and substantially constant cross section along said recess region length; a valve body slidably fitted over said valve spool, including a supply port, a discharge port separated from said supply port by a port separation length less than said recess region length, said supply port and said discharge port having substantially identical areas along said valve body; a compression type spring, axially aligned with said valve spool axis, penetrating said valve body from a spring end of said valve body, for biasing said valve spool to a normally closed position, with said valve spool recess region positioned beyond said supply port toward said discharge port to block fluid flow through said valve recess region from said supply port; a plunger pin, penetrating said valve body from a plunger pin end of said valve body opposite said valve body spring end, and having a plunger pin end of said valve for displacing said valve spool to an open position, with said valve spool recess region displaced midway between said supply port and said discharge port to allow flow through said valve recess region from said supply port to said discharge port without flow induced valve spool force imbalance; a solenoid stator, including a central pole piece with a linear bearing through it for slidably retaining said plunger pin along said valve spool axis, and an annular pole piece, axially aligned with said central pole piece, and having a diameter substantially greater than said central pole piece; a solenoid armature, coupled to said plunger pin through said stator central pole piece bearing, having an axis aligned with said plunger pin axis, a working gap surface substantially parallel to the surface of said central pole piece, and a circumferential non-working gap surface substantially parallel to the surface of said stator annular pole piece; and a solenoid coil, wound around said central pole piece, for operating said armature coupled plunger, pin with an electric signal.

Claim 20

A solenoid operated spool valve comprising: a valve spool having a spool axis including a central recess region of predetermined length and substantially constant cross section along said recess region length; a valve body slidably fitted over said valve spool, including a supply port, a discharge port separated from said supply port by a port separation length less than said recess region length, said supply port and said discharge port having substantially identical areas along said valve body; a compression type spring, axially aligned with said valve spool axis, penetrating said valve body from a spring end of said valve body, for biasing said valve spool to a normally closed position, with said valve spool recess region positioned beyond said supply port toward said discharge port to block fluid flow through said valve recess region from said supply port; a plunger pin, penetrating said valve body from a plunger pin end of said valve body opposite said valve body spring end, and having a plunger pin end of said valve for displacing said valve spool to an open position, with said valve spool recess region displaced midway between said supply port and said discharge port to allow flow through said valve recess region from said supply port to said discharge port without flow induced valve spool force imbalance; a solenoid stator, including a central pole piece with a linear bearing through it for slidably retaining said plunger pin along said valve spool axis, and an annular pole piece, axially aligned with said central pole piece, and having a diameter substantially greater than said central pole piece; a solenoid armature, coupled to said plunger pin through said stator central pole piece bearing, having an axis aligned with said plunger pin axis, a working gap surface substantially parallel to the surface of said central pole piece, and a circumferential non-working gap surface substantially parallel to the surface of said stator annular pole piece; and a solenoid coil, wound around said central pole piece, for operating said armature coupled plunger, pin with an electric signal.

Claim 21

The solenoid operated spool valve recited in claim 17 said armature is disc shaped, having a diameter substantially greater than its thickness.

Claim 22

The solenoid operated spool valve recited in claim 18, wherein said armature includes a plurality of axial holes through said armature, substantially parallel to said armature axis, sized and radially arranged around said armature axis to minimize low temperature resistance to fluidic flow through said armature, and tangentially arranged to maximize armature magnetic efficiency and response time.

Claim 23

The solenoid operated spool valve recited in claim 19, wherein said valve spool is cyclically displaced to control flow between said valve body supply port and said valve flow discharge port.

Claim 24

The solenoid operated spool valve recited in claim 20, wherein said valve spool cyclical displacement is duty cycle controlled to proportionally vary flow between said valve body supply port and said valve body discharge port.

Claim 25

The solenoid operated spool valve recited in claim 21, wherein said valve spool controls flow in a hydraulic shock absorber for a semi-active suspension system.

Claim 26

The spool valve recited in claim 1, wherein said valve spool recess region has equal area exposed to said supply port and said discharge port when said valve spool recess region is displaced midway between said supply port and said discharge port.

Claim 27

The spool valve recited in claim 7, wherein said valve spool recess region has equal areas exposed to said supply port and said discharge port when said valve spool recess region is displaced midway between said supply port and said discharge port.