CN-122009115-A - Fault tolerant brake system with manual push-through of two wheels

Abstract

There is a fault tolerant brake system with two wheels manually pushed through. A fault tolerant brake system includes a two wheel manual push-through device for selectively actuating a first pair and a second pair of wheel brakes. The master cylinder is selectively operable by actuation of the brake pedal during a manual push-through mode to generate brake actuation pressure to the at least one MC output for actuating the first pair of wheel brakes. A single-acting plunger ("SAP") is operable during a normal, non-faulty braking mode to generate brake actuation pressures at the first SAP output and the second SAP output for hydraulically actuating the first pair and the second pair of wheel brakes, respectively. A two-position three-way valve ("2P 3W valve") is hydraulically connected to the MC output, the first SAP output, and the first pair of wheel brakes. The 2P3W valve places the front wheel brake pair in fluid communication with the SAP in a normal non-faulty braking mode and in fluid communication with the master cylinder in a manual push-through braking mode.

Inventors

• B.J. Ganzel

Assignees

• 采埃孚主动安全美国有限公司

Dates

Publication Date

20260512

Application Date

20251106

Priority Date

20241112

Claims (20)

1. 1. A fault tolerant brake system including a two wheel manual push-through device for selectively actuating a first pair of wheel brakes and a second pair of wheel brakes, the system comprising: A reservoir; A master cylinder operatively providing a brake signal in response to actuation of a brake pedal connected to the master cylinder, the master cylinder being selectively operable by actuation of the brake pedal during a manual push-through mode to generate brake actuation pressure to at least one MC output for hydraulically actuating the first pair of wheel brakes; a single-acting plunger SAP operable by actuation of the electric SAP motor during a normal non-faulty braking mode to generate brake actuation pressures at the first and second SAP outputs for hydraulically actuating the first and second pairs of wheel brakes, respectively; A two-position three-way 2P3W valve hydraulically connected to the MC output, the first SAP output and the first pair of wheel brakes, the 2P3W valve selectively controlling hydraulic fluid flow from a selected one of the master cylinder and the SAP to the 2P3W valve output hydraulically connected to the first pair of wheel brakes; An auxiliary power transmission unit PTU configured for selectively providing pressurized hydraulic fluid at first and second PTU outputs to actuate first and second pairs of wheel brakes in at least one of a normal non-faulty braking mode and a backup braking mode, the auxiliary power transmission unit including an electric PTU motor configured to selectively pressurize hydraulic fluid by transmitting rotational motion to at least two pump pistons, each pump piston providing pressurized hydraulic fluid to a corresponding one of the first and second PTU outputs, each of the first and second PTU outputs providing fluid to a corresponding one of the first and second pairs of wheel brakes, and An electronic control unit ECU for selectively controlling at least one of the SAP, the auxiliary power transmission unit, and the 2P3W valve in response to the brake signal; Wherein the auxiliary power transmission unit and the SAP are fluidly connected to the reservoir, and Wherein the 2P3W valve places the first pair of wheel brakes in fluid communication with the SAP in a normal, non-faulty braking mode and in fluid communication with the master cylinder in a manual push-through braking mode.
2. 2. The brake system of claim 1, including a first traction control isolation valve hydraulically interposed between the first pair of wheel brakes and the first SAP output and the MC output via the 2P3W valve, and A second traction control isolation valve hydraulically interposed directly between the second pair of wheel brakes and the second SAP output.
3. 3. The brake system of claim 2, wherein the ECU selectively controls the first traction control isolation valve and the second traction control isolation valve.
4. 4. The brake system of claim 1, comprising a brake pressure sensor hydraulically interposed along the 2P3W valve output, the brake pressure sensor sensing hydraulic pressure within the 2P3W valve output and responsively generating a brake pressure signal, wherein the ECU controls at least one of the SAP, the auxiliary power transmission unit, and the 2P3W valve in response to the brake pressure signal.
5. 5. The brake system of claim 1, including an isolation/bleed control valve arrangement associated with each of the first and second pairs of wheel brakes, each isolation/bleed control valve arrangement being controlled by the electronic control unit.
6. 6. The brake system of claim 5, wherein each isolation/bleed control valve arrangement is in fluid communication with a selected one of the 2P3W valve output and the second SAP output to selectively receive pressurized hydraulic fluid therefrom.
7. 7. The brake system of claim 5, wherein the first traction control isolation valve is hydraulically interposed between the 2P3W valve and the isolation/bleed control valve arrangement of the first pair of wheel brakes, and wherein the second traction control isolation valve is hydraulically interposed between the second PTU output and the isolation/bleed control valve arrangement of the second pair of wheel brakes.
8. 8. The brake system of claim 1 including a pedal simulator in selective fluid communication with the master cylinder, the pedal simulator for providing a predetermined brake pedal response.
9. 9. The brake system of claim 8, comprising a simulator valve hydraulically interposed between a pedal simulator and at least one of the reservoir and a chamber of the master cylinder.
10. 10. The brake system of claim 1, wherein the 2P3W valve is a dual winding type and the electronic control unit is a first electronic control unit that selectively controls the 2P3W valve and the SAP, and the brake system includes a second electronic control unit that selectively controls the 2P3W valve and the auxiliary PTU, wherein both the first and second electronic control units control the respective SAP and auxiliary PTU in response to the brake signal.
11. 11. The brake system of claim 10, comprising a pedal simulator in selective fluid communication with the master cylinder to provide a predetermined brake pedal response, and a simulator valve hydraulically interposed between the pedal simulator and at least one of the reservoir and the chamber of the master cylinder, wherein the simulator valve is dual-winding and both the first and second electronic control units selectively control the simulator valve.
12. 12. The brake system of claim 10, including an isolation/bleed control valve arrangement associated with each of the first and second pairs of wheel brakes, wherein the second electronic control unit controls each of the isolation/bleed control valve arrangements.
13. 13. The brake system of claim 10, wherein said second electronic control unit controls said first traction control isolation valve and said second traction control isolation valve.
14. 14. The brake system of claim 1, wherein each of the first SAP output and the second SAP output is in fluid communication with a pump output of at least one pump piston via at least a corresponding first or second traction control isolation valve to selectively supply pressurized hydraulic fluid to the pump output, the auxiliary PTU selectively pressurizing pressurized hydraulic fluid from the SAP to supply pressurized hydraulic fluid to at least one pair of wheel brakes in at least one of a normal non-faulty braking mode and a backup braking mode.
15. 15. The brake system of claim 1 wherein said reservoir, said master cylinder and said SAP are co-located in a first housing and said auxiliary power transmission unit is located in a second housing spaced apart from said first housing.
16. 16. The brake system as claimed in claim 1, including an isolation/bleed control valve arrangement associated with each of the first and second pairs of wheel brakes, each isolation/bleed control valve arrangement being controlled by the electronic control unit, and Wherein the reservoir, the master cylinder, and the SAP are co-located in a first housing, and the auxiliary power transmission unit and the isolation/bleed control valve arrangement are located in a second housing that is spaced apart from the first housing.
17. 17. The brake system of claim 1, comprising a first filter hydraulically interposed between the master cylinder and the 2P3W valve along the MC output, a second filter hydraulically interposed between the SAP and the 2P3W valve along the first SAP output, and a third filter hydraulically interposed between the SAP and the second traction control isolation valve along the second SAP output, wherein the first, second, and third filters limit debris from entering the 2P3W valve from the respective master cylinder or SAP.
18. 18. The brake system of claim 1, including a pair of rear brake motors for selectively electrically actuating respective rear wheel brakes.
19. 19. The brake system of claim 1, being a vertical split system, wherein the first pair of wheel brakes includes a front left wheel brake and a front right wheel brake and the second pair of wheel brakes includes a rear left wheel brake and a rear right wheel brake.
20. 20. The brake system of claim 1, being a diagonally split system wherein the first pair of wheel brakes includes a front left wheel brake and a rear right wheel brake and the second pair of wheel brakes includes a front right wheel brake and a rear left wheel brake.

Description

Fault tolerant brake system with manual push-through of two wheels Technical Field The present disclosure relates to an apparatus and method for a fault tolerant brake system, and more particularly, to a method and apparatus for a fault tolerant brake system having two wheels manually pushed through. Background The present invention relates generally to vehicle braking systems. Vehicles are typically slowed and stopped using a hydraulic brake system. These systems vary in complexity, but foundation brake systems typically include a brake pedal, a master cylinder, fluid conduits that may be arranged in two similar but independent brake circuits, and wheel brakes in each circuit. The driver of the vehicle operates a brake pedal that is directly or indirectly connected to the master cylinder. When the brake pedal is depressed, the master cylinder generates hydraulic pressure in both brake circuits by pressurizing brake fluid. Pressurized fluid flows through fluid conduits in both circuits to actuate brake cylinders at the wheels to slow the vehicle. Foundation brake systems typically use a brake booster that provides a force to a master cylinder to assist the pedal force created by the driver. The force from the booster assists the pedal force acting on the piston of the master cylinder, generating pressurized fluid in the conduit in fluid communication with the wheel brakes. During an initial movement of the brake pedal unit in the assist mode, the driver depresses the brake pedal, causing an initial movement of the input piston of the master cylinder. Further movement of the input piston will pressurize the input chamber of the master cylinder causing fluid to flow into the pedal simulator. When fluid is diverted into the pedal simulator, a simulated pressure chamber within the pedal simulator will expand, causing movement of a piston within the pedal simulator. The movement of the piston compresses a spring assembly housed within the pedal simulator and biases the piston to provide a feedback force to the vehicle operator via the brake pedal that mimics the force felt by the operator at the brake pedal in a conventional vacuum-assisted hydraulic brake system, and thus is an intended and comfortable "brake feel" for the operator. Description of prior art Brake systems see U.S. patent application publication No. 1260/0307538 entitled "Vehicle Brake SYSTEM WITH Auxiliary Pressure Source" issued to Blaise Ganzel on month 4 of 2020, U.S. patent No. 10,730,501, published by Blaise Ganzel on month 1 of 2020, entitled "Brake SYSTEM WITH Multiple Pressure Sources"), and U.S. patent application Ser. No. 17/400,250, filed by Blaise Ganzel on month 12 of 2021, entitled "Apparatus and Method for Control of a Hydraulic Brake System Including Manual Pushthrough", all of which are incorporated herein by reference in their entirety for all purposes. Disclosure of Invention In one aspect, alone or in combination with any of the other aspects, a fault tolerant brake system is provided that includes a two wheel manual push-through device for selectively actuating a first pair and a second pair of wheel brakes. The system includes a reservoir and a master cylinder operable to provide a brake signal in response to actuation of a brake pedal connected thereto. The master cylinder is selectively operable by actuation of the brake pedal during a manual push-through mode to generate brake actuation pressure to the at least one MC output for hydraulically actuating the first pair of wheel brakes. A single-acting plunger ("SAP") is operable by actuation of the electric SAP motor during a normal non-faulty braking mode to generate brake actuation pressures at the first and second SAP outputs for hydraulically actuating the first and second pairs of wheel brakes, respectively. A two-position three-way valve ("2P 3W valve") is hydraulically connected to the MC output, the first SAP output and the first pair of wheel brakes, the 2P3W valve selectively controlling hydraulic fluid flow from a selected one of the master cylinder and the SAP to the 2P3W valve outputs hydraulically connected to the first pair of wheel brakes. An auxiliary power transmission unit ("PTU", also known as an "auxiliary brake module") is configured to selectively provide pressurized hydraulic fluid at the first PTU output and the second PTU output to actuate the first and second pairs of wheel brakes in at least one of a normal non-faulty braking mode and a backup braking mode. The auxiliary power transmission unit includes an electric PTU motor configured to selectively pressurize hydraulic fluid by transmitting rotational motion to at least two pump pistons, each pump piston providing pressurized hydraulic fluid to a corresponding one of the first and second PTU outputs. Each of the first and second PTU outputs provides fluid to a corresponding one of the first and second pairs of wheel brakes. An electronic control unit ("ECU") selectively controls at least one o