Hydraulic systems for vehicles
First Claim
1. An hydraulic system for a vehicle of the type having a front pair of wheels, and a rear pair of wheels, means for driving said wheels of a least one of said pairs, and an hydrualically actuated brake on each of said wheels, said system comprising a combined booster and hydraulic master cylinder assembly for applying all said brakes, said assembly having a pressure chamber, a reservoir for fluid, and a reservoir connection for connection to said reservoir, an hydraulic accumulator, a pedal for actuating said combined asdembly to apply said brakes normally for vehicle service retardation, a sensor for sensing the speed of rotation fo each said wheel, an electronic contorl module which receives signals from said sensor, means for controlling operation of at least one of said brakes, said means being actuated by sad control module whereby to control the behaviour of a respective wheel depending upon the nature and duration of the said signal, a servo-pressure control valve operative to control generation of servo assistance for said assembly in response to pressure generated by operation of said pedal, said servo-pressure control valve being movable between a first position in which said presure camber is in communication with said reservoir connection, and a second position in which said hydraulic accumulator is in communicatin with said pressure chamber to energise said pressure chamber, and an auxiliary control valve means responsive to a signal from said control module to energise said pressure chamber independently of operation of said servo-pressure control valve, said auxiliary control valve means being mvoable between a first position in which said reservoir connection is in communication with said reservoir, and a second position in which said reservoir connection is in communication with said hydraulic accumulator, and wherien a first hydraulic circuit is provided for said booster and comprises said pressure chamber, said reservoir, said reservoir connector, said accumulator, said servo pressure control valve, and said auxiliary valve control means;
- and a second independent hydraulic circuit is provided for said master cylinder and said means for controlling operation of at least one of said brakes, there being no mixing of the hydraulic fluid between the two circuits.
1 Assignment
0 Petitions
Accused Products
Abstract
In a combined booster and hydraulic master cylinder assembly the reservoir connection is adapted to serve as an inlet for high pressure fluid and by way of which the assembly can be operated independently of the pedal. High pressure fluid is supplied to the connection under the control of auxiliary control valve responsive to signals for a sensor. The sensor may be arranged to enable the assembly to be used in a variety of modes, for example for traction control, as a `hill holder`, and for remote control of the speed of the vehicle.
25 Citations
17 Claims
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1. An hydraulic system for a vehicle of the type having a front pair of wheels, and a rear pair of wheels, means for driving said wheels of a least one of said pairs, and an hydrualically actuated brake on each of said wheels, said system comprising a combined booster and hydraulic master cylinder assembly for applying all said brakes, said assembly having a pressure chamber, a reservoir for fluid, and a reservoir connection for connection to said reservoir, an hydraulic accumulator, a pedal for actuating said combined asdembly to apply said brakes normally for vehicle service retardation, a sensor for sensing the speed of rotation fo each said wheel, an electronic contorl module which receives signals from said sensor, means for controlling operation of at least one of said brakes, said means being actuated by sad control module whereby to control the behaviour of a respective wheel depending upon the nature and duration of the said signal, a servo-pressure control valve operative to control generation of servo assistance for said assembly in response to pressure generated by operation of said pedal, said servo-pressure control valve being movable between a first position in which said presure camber is in communication with said reservoir connection, and a second position in which said hydraulic accumulator is in communicatin with said pressure chamber to energise said pressure chamber, and an auxiliary control valve means responsive to a signal from said control module to energise said pressure chamber independently of operation of said servo-pressure control valve, said auxiliary control valve means being mvoable between a first position in which said reservoir connection is in communication with said reservoir, and a second position in which said reservoir connection is in communication with said hydraulic accumulator, and wherien a first hydraulic circuit is provided for said booster and comprises said pressure chamber, said reservoir, said reservoir connector, said accumulator, said servo pressure control valve, and said auxiliary valve control means;
- and a second independent hydraulic circuit is provided for said master cylinder and said means for controlling operation of at least one of said brakes, there being no mixing of the hydraulic fluid between the two circuits.
- View Dependent Claims (4, 6, 7, 8, 9, 10, 11, 12, 13)
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2. An hydraulic system for a vehicle of the type having a front pair of wheels, and a rear pair of wheel, means for driving said wheels of at least one of said pairs, and an hydraulically actuated brake on each of said wheels, said system comprising a combined booster and hydraulic master cylinder assembly for applying all said brakes, said assembly having a PG,22 pressure chamber, a reservoir for fluid, and a reservoir connection for connection to said reservoir, an hydraulic accumulator, a pedal fr actuating said combined assembly to apply said brakes normally for vehicle service retardation, a sesnor for sensing the speed of said vehicle, an electronic control module which receives signals from said sensor, means for controlling operation of at least one of said brakes, said means being actuatd by said control module whereby to control the behaviour of a respective wheel depending upon the nature and duration of the said signal, a servo-pressure control valve operative to control generation of servo assistance for said assembly in response to presure generated by operation of said pedal, said servo-pressure control valve being movable between a first position in which said pressure chamber is in communication with said reservoir connection, and a second position in which said hydraulic accumulator is in communication with said pressure chamber to energise said pressure chabmer, and an auxiliary control valve means responsive to a signal from said control module to energise said pressure chamber independently of operation of said servo-pressure control valve, said auxiliary control valve means being mvoable between a first positin in which said reservoir connection is in communication with said reservoir, and a second position in which said reservoir connection is in communicatin with said hydraulic accumulator, and wherein a first hydraulic circuit is provided for sad booster and comprises said pressure chamber, said reservoir, said reservoir connector, said accumulator, said servo pressure control valve, and said auxiliary valve control emans;
- and a second independent hydraulic circuit is provided for said master cylinder and said means for contorlling operation of at leat one of said brakes, there being no mixing of the hydraulic fluid between the two circuits.
- View Dependent Claims (3)
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5. A system according to cliam 4, wherein the solenoid-operated valve comprises a housing, a solenoid responsive to signals from said control module, a pair of spaced seatings in said housing, a double-acting valve member which is alternatively engageable with one of said pair of spaced seatings under the control of sid solenoid, one of said seatings being disposed between said reservoir connection and said reservoir, and the other of said seatings being disposed between said accumulator and said reservoir connection.
- 14. An hydraulic system for a vehicle of the type having a front pair of wheels, and a rear pair of wheels, means for driving said wheels of a least one of said pairs, and an hydraulically actuated brake on each of said wheels, said system comprising a combined booster and hydraulic master cylinder assembly for applying all said brakes, said assembly having a pressure chamber, a reservoir for fluid, and a reservoir connection for connection to said reservoir, an hydraulic accumulator, a pedal for actuating said combined assembly to apply said brakes normally for vehicle service retardation, a sensxsor for sensing the speed of rotation of eahc said wheel, an electronic control module which receives signals from said sensor, means for controlling operation of at least one of said brakes, said means being actuated by said control module whereby to control the behaviour of a respective wheel depending upon the nature and duration of the said signal, a first, servo-pressure contorl, valve operative to control generation of servo assistance for said assembly in response to pressure generated by operation of said pedal, said servo-pressure control valve being movable between a first position in which said pressure cahmber is in communication with saied reservoir connection, and a second position in which said hydraulic accumulator is in communication with said pressure chamber to energise said pressure chamber, and a second valve comprising an auxiliary control valve means responsive to a signal from said control module to energise said pressure chamber independently of the position of said pedal and the operation of said first, servo-pressure control valve, said auxiliary control valve means being movable between a first position in which said reservoir connection is in communication with said reservoir, and a secon dposition in which said reservoir connection is in communication with said hydraulic accumulator, and wherein said assembly further comrpises an auxiliary piston working in an auxiliary chamber which is in fluid communication with said reservoir connection when said pedal is not depressed, and an output member connected to said auxiliary piston, said output member also comrpising a mechanical input to said master cylinder assembly, operation of said second auxiliary control valve allowing acucmulator pressure to act in said auxiliary chamber on said auxiliary piston and thereby move said output member independently of said pedal to actuaate said master cylinder.
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15. An hydrualic system for a vehicle of the type having a front pair of wheels, and a rear pair of wheels, means for driving said wheels of a least one of said apirs, and an hydraulically actuated brake on each of said wheels, said sytem comprising a combined booster and hydraulic master cylinder assembly for applying all said brakes, said assembly having a pressure chamber, a resevoir for fluid, and a reservoir connection for connection to said reservoir, an hydrualic accumulator, a pedal for actuating said combined assembly to apply said brakes normally for vehicle service retardation, a sensor for sensing the speed of said vehicle, an electronic control module which receives signals from said sensor, means for controlling operation of at least one of said brakes, said means being actuated by said control module whereby to control the behaviour of a respective wheel depending upon the nature and duration of the said signal, a first, servo-pressure control, valve operative to control generation of servo assistance for said assembly in response to pressure generated by operation of said pedal, said servo-pressure control valve being movable between a first position in which said pressure chamber is in communication with said reservoir conection, and a second position in which said hydraulic accumulator is in communication with said pressure chamber to energise said pressure chamber, and a second valve comprising an auxiliary control valve means responsive to a signal from said control module to energise said pressue chamber independently of the position of said pedal and the operation of said first, servo-pressure control valve, said auxiliary control valve means being movable between a first position inwhich said reservoir connection is in communication with said reservoir, and a second position in which said reservoir connection is in communication with said hydraulic accumulator and wherein said assembly further coprises an auxiliary piston working in an auxiliary chamber which is in fluid communication with said reservoir connection when said pedal is not depressed, and an outupt member connected to said auxiliary piston, said output member also comprising a mechanical input to said master cylinder assembly, operation of said second auxiliary control valve allowing accumulator pressure to act in said auxiliary chamber on said auxiliary piston and thereby move said output member independently of said pedal to actuate said master cylinder..
Specification