Power steering system and control valve
First Claim
1. An apparatus for use in a power steering system comprising:
- a valve having a left turn assist outlet and a right turn assist outlet, said valve operable for controlling pressure of steering fluid through at least one of said turn assist outlets;
a sensor for detecting steering wheel induced torque, said sensor generating a signal upon detection of said torque; and
said valve selectively varying said pressure as a function of said signal generated by said sensor;
said valve further including;
a body;
a first bore disposed within said body having a first port;
a supply inlet supplying fluid to said first port;
a linearly displaceable first spool disposed in said first bore;
a second port of said first bore communicating with a first one of said turn assist outlets;
a third port in said first bore communicating with a second one of said turn assist outlets;
a return outlet;
a fourth port in said first bore communicating with said return outlet;
a second bore disposed in said body and having a first port communicating with said supply inlet;
a second port in said second bore communicating with a first exchange passageway which communicates with said third port of said first bore;
a third port of said second bore communicating with said second of said turn assist outlets;
a fourth port of said second bore communicating with a second exchange passageway which further communicates with a fifth port in said first bore, said fifth port in said first bore communicating with said second port in said first bore;
a return passageway communicating between said fourth port in said first bore and a fifth port in said second bore; and
a sixth port in said second bore communicating with said return outlet.
3 Assignments
0 Petitions
Accused Products
Abstract
A power steering system employs a valve which directly controls the direction of flow of steering fluid and the degree of pressure of the steering fluid. In another aspect of the present invention, a sensor is used to detect steering wheel induced torque. The sensor supplies a signal to an electrical control unit which, in turn, sends a signal to an electromagnetic device controlling a spool within a valve. In a further aspect of the present invention, a non-rotary valve controls steering fluid pressure and flow through left and right turn assist outlets. In still another aspect of the present invention, a valve employs a pair of bores within which spools are linearly movable by electromagnetic devices. In yet another aspect of the present invention, a valve is provided for controlling the magnitude and direction of steering fluid pressure and flow to a steering cylinder; the valve is not mechanically engaged with a rotating member of the steering system.
101 Citations
29 Claims
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1. An apparatus for use in a power steering system comprising:
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a valve having a left turn assist outlet and a right turn assist outlet, said valve operable for controlling pressure of steering fluid through at least one of said turn assist outlets; a sensor for detecting steering wheel induced torque, said sensor generating a signal upon detection of said torque; and said valve selectively varying said pressure as a function of said signal generated by said sensor; said valve further including; a body; a first bore disposed within said body having a first port; a supply inlet supplying fluid to said first port; a linearly displaceable first spool disposed in said first bore; a second port of said first bore communicating with a first one of said turn assist outlets; a third port in said first bore communicating with a second one of said turn assist outlets; a return outlet; a fourth port in said first bore communicating with said return outlet; a second bore disposed in said body and having a first port communicating with said supply inlet; a second port in said second bore communicating with a first exchange passageway which communicates with said third port of said first bore; a third port of said second bore communicating with said second of said turn assist outlets; a fourth port of said second bore communicating with a second exchange passageway which further communicates with a fifth port in said first bore, said fifth port in said first bore communicating with said second port in said first bore; a return passageway communicating between said fourth port in said first bore and a fifth port in said second bore; and a sixth port in said second bore communicating with said return outlet. - View Dependent Claims (2, 3, 4, 5)
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6. An apparatus for use in a power steering system comprising:
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a valve having a left turn assist outlet and a right turn assist outlet, said valve operable for controlling pressure of steering fluid through at least one of said turn assist outlets; a sensor for detecting steering wheel induced torque, said sensor generating a signal upon detection of said torque; said valve selectively varying said pressure as a function of said signal generated by said sensor, said valve further including; a first spool linearly movable within a first bore for selectively and variably constricting said fluid flowing therethrough; a first electromagnetic device energizable for controlling the position of said first spool within said first bore as a function of said signal generated by said sensor; a second spool linearly movable within a second bore for selectively and variably constricting said fluid flowing therethrough; and a second electromagnetic device energizable for controlling the position of said second spool within said second bore as a function of said signal generated by said sensor. - View Dependent Claims (7, 8, 9, 10)
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11. A valve for a power steering system comprising:
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a body having a first bore and a second bore; a pair of linearly displaceable spools disposed in said bores, said first bore including a first port; a supply inlet supplying fluid to said first port; a linearly displaceable first spool disposed in said first bore; a second port of said first bore communicating with a first turn assist outlet; a third port in said first bore communicating with a second turn assist outlet; a return outlet; and a fourth port in said first bore communicating with said return outlet. - View Dependent Claims (12, 13, 14)
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15. A valve for a power steering system comprising:
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a body having a first bore and a second bore; a pair of linearly displaceable spools disposed in said bores, each of said pair of spools further including; a lower land having a peripheral surface substantially sealable against a portion of an interior surface of a congruent of said bores; an upper land having a peripheral surface substantially sealable against a portion of said interior surface of the congruent of said bores; a bridge coupling said lands together, said bridge having a clearance to said interior surface of the congruent said bores; and a seat interface mounted on said lower land selectively constricting said flow through the congruent of said bores; said spools being disposed in a fully open position when substantially equal minimum fluid pressure is desired to exit turn assist outlets, said fully open position of said spools being defined by said closures fully removed from adjacent seats within said bores thereby allowing said fluid to flow therepast. - View Dependent Claims (16, 17)
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18. A valve for a power steering system comprising:
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a body having a first bore and a second bore; and a pair of linearly displaceable spools disposed in said bores; wherein each of said pair of spools have elongated hollow lower and upper chambers coaxially running within a congruent bore, said chambers being transversely accessible by apertures. - View Dependent Claims (19, 20)
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21. A power steering system comprising:
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a member rotatable in response to steering wheel induced torque; a pinion gear rotatably coupled to said rotatable member; a valve directly controlling direction of flow of steering fluid and degree of pressure of said steering fluid, said valve only interfacing with said rotatable member in an electrical and not mechanical manner; a sensor for detecting steering wheel induced torque, said sensor generating a signal upon detection of said torque; and said valve selectively varying said flow as a function of said signal generated by said sensor, said valve including a body, a pair of bores disposed in said body and a pair of spools linearly movable within said pair of bores. - View Dependent Claims (22, 23)
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24. A method for operating a single valve assembly in a power steering system comprising the steps of:
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(a) supplying steering fluid through a supply inlet and to a first bore within said valve; (b) moving a first spool within said first bore in a linear manner between a fully opened position and a fully closed position; (c) allowing a flow of said fluid from said first bore and through a first turn assist outlet when said spool is in any portion of its stroke movement; (d) blocking flow of said fluid through said first bore from said supply inlet when said spool is in any portion of its stroke movement; (e) controlling flow of said steering fluid; (f) controlling a degree of pressure of said steering fluid; (g) supplying steering fluid through said supply inlet and to a second bore within said valve; (h) moving a second spool within said second bore in a linear manner between a fully opened position and a fully closed position; (i) flowing said fluid from said second bore and to a second turn assist outlet when said second spool is in any portion of its stroke movement; and (j) blocking flow of said fluid through said second bore from said supply inlet when said second spool is in any portion of its stroke movement. - View Dependent Claims (25, 26)
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27. A method of installing and operating a power steering system comprising the steps of:
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(a) providing a rotatable member with a pinion gear coupled to an end thereof; (b) providing a steering cylinder having a rack linearly movable therein; (c) enmeshing said pinion gear with said rack; (d) coupling a valve to said steering cylinder for operably flowing steering fluid directly thereto through conduits; (e) interfacing said valve with said rotatable member in an electrical and not mechanical manner; and (f) linearly moving a pair of spools incremental distances within said valve thereby controlling direction and pressure of steering fluid flow. - View Dependent Claims (28)
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29. An apparatus for use in a power steering system comprising:
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a valve having a left turn assist outlet and a right turn assist outlet, said valve operable for controlling pressure of steering fluid through at least one of said turn assist outlets; a sensor for detecting steering wheel induced torque, said sensor generating a signal upon detection of said torque; said valve selectively varying said pressure as a function of said signal generated by said sensor, said valve further including; (a) a first spool movable within a first bore for selectively and variably constricting said fluid flowing through said first bore; (b) a first electromagnetic device energizable for controlling the position of said first spool within said first bore as a function of said signal generated by said sensor; (c) a second spool movable within a second bore for selectively and variably constricting said fluid flowing through said second bore; and (d) a second electromagnetic device energizable for controlling the position of said second spool within said second bore as a function of said signal generated by said sensor.
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Specification