A vehicle braking system includes a master cylinder coupled to a brake pedal and establishing fluid communication to wheel cylinder(s) of primary and secondary circuits via respective outputs. A pressure sensor detects actual, non-boosted demand pressure. Each circuit includes a motor-driven pump de
A vehicle braking system includes a master cylinder coupled to a brake pedal and establishing fluid communication to wheel cylinder(s) of primary and secondary circuits via respective outputs. A pressure sensor detects actual, non-boosted demand pressure. Each circuit includes a motor-driven pump defining pressure and suction sides, inlet and outlet valves, a normally-open isolation valve, and a normally-closed apply pressure control valve. A pedal feel simulator receives hydraulic fluid from the master cylinder when the isolation valves are closed. A controller receives a signal from the pressure sensor and generates corresponding control signals for the motor-driven pump and the apply pressure control valve of each circuit to pressurize the pressure side of each circuit equal to the sensed demand pressure plus a predetermined boost factor, and the actual pressure at each wheel cylinder is configured for individual manipulation by selective opening and closing of the inlet and outlet valves.
대표청구항▼
1. A vehicle braking system comprising: a master cylinder configured to receive an input from a brake pedal, the master cylinder having an outlet for a primary circuit including at least one wheel cylinder operable to provide a braking force on a wheel when supplied with pressurized hydraulic fluid,
1. A vehicle braking system comprising: a master cylinder configured to receive an input from a brake pedal, the master cylinder having an outlet for a primary circuit including at least one wheel cylinder operable to provide a braking force on a wheel when supplied with pressurized hydraulic fluid, and an outlet for a secondary circuit including at least one wheel cylinder operable to provide a braking force on a wheel when supplied with pressurized hydraulic fluid;a pressure sensor operable to detect an actual, non-boosted driver demand pressure generated at one of the master cylinder outputs from depression of the brake pedal;at least one pump provided in each of the primary circuit and the secondary circuit, the at least one pump defining a pressure side and a suction side of each of the respective primary and secondary circuits;an inlet valve positioned adjacent each wheel cylinder on the pressure side of each of the primary circuit and the secondary circuit;an outlet valve positioned adjacent each wheel cylinder on the suction side of each of the primary circuit and the secondary circuit;a normally open isolation valve positioned between each master cylinder output and the pressure side of the respective primary circuit and the secondary circuit, each isolation valve being movable between an open position that allows fluid communication and a closed position that blocks fluid communication;a pedal feel simulator configured to receive hydraulic fluid from the master cylinder to provide a reaction force to the brake pedal when the isolation valves of the primary and secondary circuits are closed;at least one motor operable to drive the pumps of the primary and secondary circuits to generate hydraulic fluid pressure in the pressure side for supplying to the respective wheel cylinders through the respective inlet valves;a normally closed apply pressure control valve positioned in each of the primary circuit and the secondary circuit between the pressure side and the suction side of the respective circuit, each apply pressure control valve being movable between a closed position in which the full hydraulic fluid pressure at the pressure side is provided to the respective inlet valve and an open position in which the pressure provided to the respective inlet valve is reduced in comparison to that at the pressure side; anda controller operable to receive a signal from the pressure sensor and generate corresponding control signals for the at least one motor and the apply pressure control valves of each of the primary and secondary circuits to produce a hydraulic fluid pressure in the pressure side of each of the primary and secondary circuits equal to the sensed driver demand pressure plus a predetermined boost factor, the actual pressure at each wheel cylinder being configured for individual manipulation by selective opening and closing of the associated inlet and outlet valves. 2. The vehicle braking system of claim 1, wherein the at least one pump of the primary and the at least one pump of the secondary circuit are driven by a single motor. 3. The vehicle braking system of claim 2, wherein the at least one pump element for each circuit, the inlet valves and outlet valves for all wheel cylinders, the isolation valves, and the apply pressure control valves are all provided within a common housing. 4. The vehicle braking system of claim 1, further comprising a circuit isolation valve having a first side in fluid communication with the pressure side of the primary circuit and a second side in fluid communication with the pressure side of the secondary circuit, the circuit isolation valve having a shuttle biased to a central position and movable against a bias force in either direction in response to exposure to a pressure differential, the shuttle of the circuit isolation valve being selectively exposed to a potential pressure differential between the pressure sides of the primary and secondary circuits by a normally closed diversion valve. 5. The vehicle braking system of claim 4, wherein the at least one pump element for each circuit, the inlet valves and outlet valves for all wheel cylinders, the isolation valves, the circuit isolation valve, the diversion valve, and the apply pressure control valves are all provided within a common housing. 6. The vehicle braking system of claim 1, wherein there is no accumulator device in the system for storing pressurized hydraulic fluid pressurized by the pumps. 7. The vehicle braking system of claim 1, wherein each of the primary and secondary circuits includes multiple wheel cylinders, and the pressure side and the suction side defined by the at least one pump of each circuit is shared by all wheel cylinders of the respective circuit. 8. The vehicle braking system of claim 1, wherein the apply pressure control valves are modulated solenoid valves. 9. A method of operating a vehicle braking system, the method comprising: providing a primary circuit including at least one wheel cylinder operable to provide a braking force on a wheel when supplied with pressurized hydraulic fluid and a secondary circuit including at least one wheel cylinder operable to provide a braking force on a wheel when supplied with pressurized hydraulic fluid, the primary and secondary circuits being in selective fluid communication with respective outputs of a master cylinder;providing an inlet valve positioned adjacent each wheel cylinder on a pressure side of each of the primary circuit and the secondary circuit and an outlet valve positioned adjacent each wheel cylinder on a suction side of each of the primary circuit and the secondary circuit;receiving an input from a brake pedal at the master cylinder;isolating the pressure side of both the primary and secondary circuits from the master cylinder outputs and establishing fluid communication between at least one of the master cylinder outputs and a pedal feel simulator;detecting an actual, non-boosted driver demand pressure generated at one of the master cylinder outputs from depression of the brake pedal;operating at least one pump provided in each of the primary circuit and the secondary circuit and modulating a normally closed apply pressure control valve positioned in each of the primary circuit and the secondary circuit with respective signals corresponding to the detected driver demand pressure to produce a hydraulic fluid pressure in the pressure side of each of the primary and secondary circuits equal to the sensed driver demand pressure plus a predetermined boost factor; andmodulating the actual pressure at at least one individual wheel cylinder by selective opening and closing of the associated inlet and outlet valves. 10. The method of claim 9, wherein the actual pressure at the at least one individual wheel cylinder is modulated to accommodate blending the hydraulic braking of the braking system with another braking source coupled to a wheel of the vehicle. 11. The method of claim 9, further comprising driving the at least one pump of the primary and the at least one pump of the secondary circuit with a single motor. 12. The method of claim 9, further comprising detecting a failure in one of the primary and secondary circuits and sharing pressure from the other of the primary and secondary circuit by opening a normally closed diversion valve to expose a circuit isolation shuttle valve to both the pressure side of the primary circuit and a pressure side of the secondary circuit. 13. The method of claim 12, further comprising re-stroking the circuit isolation shuttle valve by closing all of the inlet valves to trap pressure at the wheel cylinders, then opening the apply pressure control valve of the non-failed circuit to reduce the pressure at the pressure side allowing a shuttle of the circuit isolation shuttle valve to return to a central position, then re-building pressure at the pressure side of the non-failed circuit with the at least one pump for supplementing the trapped pressure at the wheel cylinders. 14. The method of claim 9, wherein each of the primary and secondary circuits is provided with multiple wheel cylinders, the method further comprising sharing the hydraulic fluid pressure produced in the pressure side of each of the primary and secondary circuits among all wheel cylinders of the respective circuit. 15. The vehicle braking system of claim 1, further comprising a master cylinder fluid reservoir, wherein a pressure side of the pump of the primary circuit and a pressure side of the pump of the secondary circuit are selectively coupled to the master cylinder fluid reservoir through the respective apply pressure control valves. 16. The vehicle braking system of claim 1, wherein the primary and secondary circuits are independent from each other with respect to fluid separation therebetween. 17. The method of claim 9, wherein modulating the normally closed apply pressure control valves positioned in the primary and secondary circuits includes selectively establishing fluid communication between a pressure side of the pump of the primary circuit and a pressure side of the pump of the secondary circuit with a master cylinder fluid reservoir through the respective apply pressure control valves.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (16)
Sekiguchi Akihiko,JPX, Anti-lock fluid pressure control apparatus with fail-safe mechanism.
Yosida Akihide (Ichinomiya JPX) Numata Kenichi (Chiryu JPX) Tsuru Naohiko (Handa JPX) Suzuki Hideaki (Schwabisch-hall DEX), Braking apparatus for use in a motor vehicle.
Harris Alan Leslie,GBX ; Fuller Robert Gregory,GBX ; Uzzell Robert George,GBX ; Mortimer Ivan,GBX, Hydraulic braking systems of the brake-by-wire type for vehicles.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.