ELECTRONIC BRAKE SYSTEM AND METHOD FOR OPERATING THE SAME

• US 20190092302A1
• Filed: 09/22/2018
• Published: 03/28/2019
• Est. Priority Date: 09/25/2017
• Status: Active Grant

• Current Assignee: HL Mando Corporation (Halla Holdings Corporation)
• Original Assignee: Mando Corporation
• Inventors: JEONG, Hyojin, CHOI, Seong Ho
• Granted Patent: US 10,906,519 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60T 13/165 Master cylinder integrated or hydraulically coupled with booster
• CPC Class Codes: B60T 13/58 Combined or convertible systems
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 15/028 in hydraulic systems
• CPC Class Codes: B60T 17/221 Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M
• CPC Class Codes: B60T 2270/402 Back-up
• CPC Class Codes: B60T 2270/404 Brake-by-wire or X-by-wire failsafe
• CPC Class Codes: B60T 2270/406 Test-mode; Self-diagnosis
• CPC Class Codes: B60T 2270/604 Merging friction therewith; Adjusting their repartition
• CPC Class Codes: B60T 2270/82 Brake-by-Wire, EHB
• CPC Class Codes: B60T 8/17 Using electrical or electronic regulation means to control braking detecting or indicating faulty operation B60T8/885
• CPC Class Codes: B60T 8/341 Systems characterised by their valves B60T8/36, B60T8/38 take precedence
• CPC Class Codes: B60T 8/4081 Systems with stroke simulating devices for driver input B60T8/4077 takes precedence
• CPC Class Codes: B60T 8/409 characterised by details of the stroke simulating device
• CPC Class Codes: B60T 8/90 using a simulated speed signal to test speed responsive control means

Abstract

An electronic brake system and a method for operating the same are disclosed. The electronic brake system includes a hydraulic-pressure supply device and a hydraulic-pressure control unit. The hydraulic-pressure supply device operates a hydraulic piston using an electric signal corresponding to a displacement of a brake pedal, and thus generates hydraulic pressure. The hydraulic-pressure control unit controls hydraulic pressure of a pressure medium supplied to individual wheel cylinders. The electronic brake system controls a plurality of valves mounted to the hydraulic-pressure control unit, and thus performs a normal operation mode, an abnormal operation mode, a regenerative braking mode, and an inspection mode using the valves.

Claims

1. An electronic brake system comprising:

a hydraulic-pressure supply device configured to generate a hydraulic pressure by operating a hydraulic piston using an electric signal that is output in response to a displacement of a brake pedal, and include not only a first pressure chamber formed at one side of the hydraulic piston movably disposed in a cylinder block, but also a second pressure chamber formed at the other side of the hydraulic piston; and

a hydraulic control unit configured to include not only a first hydraulic circuit to control a hydraulic pressure applied to two wheel cylinders, but also a second hydraulic circuit to control a hydraulic pressure applied to two other wheel cylinders,

wherein the hydraulic control unit includes;

a first hydraulic passage configured to communicate with the first pressure chamber;

second and third hydraulic passages branched from the first hydraulic passage, and respectively connected to the first and second hydraulic circuits;

a fourth hydraulic passage connected to the second hydraulic passage while communicating with the second pressure chamber;

a fifth hydraulic passage configured to connect the second hydraulic passage to the third hydraulic passage; and

a sixth hydraulic passage configured to connect the second hydraulic passage to the fifth hydraulic passage.

2. The electronic brake system according to claim 1, wherein the hydraulic control unit includes:

first and second valves provided in the second hydraulic passage to control flow of a pressure medium;

a third valve provided in the third hydraulic passage to control flow of a pressure medium;

a fourth valve provided in the fourth hydraulic passage to control flow of a pressure medium;

a fifth valve disposed between one position connected to the sixth hydraulic passage on the fifth hydraulic passage and another position connected to the second hydraulic passage on the fifth hydraulic passage;

a sixth valve disposed between one position connected to the sixth hydraulic passage on the fifth hydraulic passage and another position connected to the third hydraulic passage on the fifth hydraulic passage; and

a seventh valve provided in the sixth hydraulic passage.

3. The electronic brake system according to claim 2, wherein:

each of the second, fourth, and seventh valves is provided as a solenoid valve to control bidirectional flow of the pressure medium;

the first valve is provided as a check valve that allows only flow of the pressure medium flowing from the first pressure chamber to the first hydraulic circuit;

the third valve is provided as a check valve that allows only flow of the pressure medium flowing from the first pressure chamber to the second hydraulic circuit;

the fifth valve is provided as a check valve that allows only flow of the pressure medium flowing from the second hydraulic passage to the position connected to the sixth hydraulic passage; and

the sixth valve is provided as a check valve that allows only flow of the pressure medium flowing from the third hydraulic passage to the position connected to the sixth hydraulic passage.

4. The electronic brake system according to claim 3, further comprising:

a generator provided in two wheel cylinders of the first hydraulic circuit.

5. The electronic brake system according to claim 4, further comprising:

a reservoir configured to store a pressure medium therein;

a master cylinder configured to include a master chamber and a master piston, wherein the master piston is provided to form a displacement changeable by operation of a brake pedal, pressurizes the pressure medium stored in the master chamber, and discharges the pressurized pressure medium;

a simulation device configured to include a simulation chamber and a simulation piston, wherein the simulation piston is provided to form a displacement changeable by the pressure medium discharged from the master chamber, pressurizes the pressure medium stored in the simulation chamber, and discharges the pressurized pressure medium; and

a reservoir passage through which the master chamber, the simulation chamber, and the reservoir communicate with one another.

6. The electronic brake system according to claim 5, further comprising:

a simulator check valve provided in the reservoir passage, and allows the pressure medium to flow in only one direction from the reservoir to the master chamber and the simulation chamber; and

a simulator valve provided in a bypass passage connected parallel to the simulator check valve on the reservoir passage, and configured to control flow of bidirectional flow of the pressure medium.

7. The electronic brake system according to claim 6, wherein:

the master piston includes a first master piston directly pressurized by the brake pedal and a second master piston indirectly pressurized by the first master piston;

the master chamber includes a first master chamber in which the first master piston is disposed and a second master chamber in which the second master piston is disposed;

the simulation piston is provided to form a displacement by operation of the pressure medium that is pressurized and discharged from the first master chamber; and

the reservoir passage is provided to allow the first master chamber, the simulation chamber, and the reservoir to communicate with one another.

8. The electronic brake system according to claim 7, wherein the simulation device further includes a reaction force spring configured to elastically support the simulation piston.

9. The electronic brake system according to claim 8, further comprising:

a first dump passage configured to connect the first pressure chamber to the reservoir;

a second dump passage configured to connect the second pressure chamber to the reservoir;

a first dump valve provided in the first dump passage to control flow of the pressure medium, and provided as a check valve that allows only flow of the pressure medium flowing from the reservoir to the first pressure chamber;

a second dump valve provided in the second dump passage to control flow of the pressure medium, and provided as a check valve that allows only flow of a pressure medium flowing from the reservoir to the second pressure chamber; and

a third dump valve provided in a bypass passage connected parallel to the second dump valve on the second dump passage so as to control flow of the pressure medium, and provided as a solenoid valve that controls bidirectional flow of the pressure medium flowing between the reservoir and the second pressure chamber.

10. The electronic brake system according to claim 9, further comprising:

a first backup passage configured to connect the first master chamber to the first hydraulic circuit;

a second backup passage configured to connect the second master chamber to the second hydraulic circuit;

a first cut valve provided in the first backup passage to control flow of the pressure medium; and

a second cut valve provided in the second backup passage to control flow of the pressure medium.

11. The electronic brake system according to claim 4, wherein the second valve is disposed between the first hydraulic circuit and a specific position connected to the fourth hydraulic passage on the second hydraulic passage.

12. The electronic brake system according to claim 4, wherein the second valve is disposed between one position where the first valve is provided on the second hydraulic passage and another position connected to the fourth hydraulic passage on the second hydraulic passage.

13. The electronic brake system according to claim 4, wherein the hydraulic control unit further includes:

a seventh hydraulic passage branched from the fourth hydraulic passage, and connected to the third hydraulic passage.

14. The electronic brake system according to claim 13, wherein the hydraulic control unit includes:

a first valve provided in the second hydraulic passage to control flow of the pressure medium;

a second valve provided in the third hydraulic passage to control flow of the pressure medium;

a third valve provided in the fourth hydraulic passage to control flow of the pressure medium;

a fourth third valve provided in the fifth hydraulic passage to control flow of the pressure medium;

a fifth valve provided in the sixth hydraulic passage to control flow of the pressure medium; and

a sixth valve provided in the seventh hydraulic passage to control flow of the pressure medium.

15. The electronic brake system according to claim 14, wherein:

each of the first and second valves is provided as a check valve that allows only flow of the pressure medium flowing from the first pressure chamber to the first and second hydraulic circuits; and

the sixth valve is provided as a check valve that allows only flow of the pressure medium flowing from the second pressure chamber to the third hydraulic passage; and

each of the third, fourth, and fifth valves is provided as a solenoid valve to control bidirectional flow of the pressure medium.

16. The electronic brake system according to claim 13, wherein the hydraulic control unit includes:

a first valve provided in the second hydraulic passage to control flow of a pressure medium;

a second valve provided in the third hydraulic passage to control flow of a pressure medium;

a third valve provided in the fourth hydraulic passage to control flow of a pressure medium;

a fourth valve disposed between one position connected to the sixth hydraulic passage on the fifth hydraulic passage and another position connected to the second hydraulic passage on the fifth hydraulic passage, and configured to control flow of a pressure medium;

a fifth valve disposed between one position connected to the sixth hydraulic passage on the fifth hydraulic passage and another position connected to the third hydraulic passage on the fifth hydraulic passage, and configured to control flow of a pressure medium;

a sixth valve provided in the sixth hydraulic passage to control flow of a pressure medium; and

a seventh valve provided in the seventh hydraulic passage to control flow of a pressure medium.

17. The electronic brake system according to claim 16, wherein:

each of the first and second valves is provided as a check valve that allows only flow of the pressure medium flowing from the first pressure chamber to the first and second hydraulic circuits;

the fourth valve is provided as a check valve that allows only flow of the pressure medium flowing from the position connected to the second hydraulic passage to the other position connected to the sixth hydraulic passage;

the fifth valve is provided as a check valve that allows only flow of the pressure medium flowing from the position connected to the third hydraulic passage to the other position connected to the sixth hydraulic passage;

the seventh valve is provided as a check valve that allows only flow of the pressure medium flowing from the second pressure chamber to the third hydraulic passage; and

each of the third and sixth valves is provided as a solenoid valve to control bidirectional flow of the pressure medium.

18. The electronic brake system according to claim 16, wherein:

each of the first and second valves is provided as a check valve that allows only flow of the pressure medium flowing from the first pressure chamber to the first and second hydraulic circuits;

the third valve is provided as a check valve that allows only flow of the pressure medium flowing from the second pressure chamber to the second hydraulic passage;

the fourth valve is provided as a check valve that allows only flow of the pressure medium flowing from the position connected to the second hydraulic passage to the other position connected to the sixth hydraulic passage;

the fifth valve is provided as a check valve that allows only flow of the pressure medium flowing from the position connected to the third hydraulic passage to the other position connected to the sixth hydraulic passage;

the seventh valve is provided as a check valve that allows only flow of the pressure medium flowing from the second pressure chamber to the third hydraulic passage; and

the sixth valve is provided as a solenoid valve to control bidirectional flow of the pressure medium.

19. The electronic brake system according to claim 17, wherein the hydraulic control unit further includes:

an eighth valve disposed between the first valve and the first hydraulic circuit on the second hydraulic passage so as to control flow of the pressure medium,

wherein the eighth valve is provided as a solenoid valve to control bidirectional flow of the pressure medium.

20. The electronic brake system according to claim 19, further comprising:

a generator provided in two wheel cylinders of the first hydraulic circuit.

21. The electronic brake system according to claim 20, wherein the eighth valve is disposed between one position connected to the fourth hydraulic passage on the second hydraulic passage and another position connected to the first hydraulic passage on the second hydraulic passage.

22. The electronic brake system according to claim 20, wherein the eighth valve is disposed between one position where the first valve is provided on the second hydraulic passage and another position connected to the fourth hydraulic passage on the second hydraulic passage.

23. A method for operating the electronic brake system according to claim 3, the method comprising:

performing a normal operation mode,

wherein the normal operation mode is classified into a low-pressure mode for providing a relatively low hydraulic pressure and a high-pressure mode for providing a relatively high hydraulic pressure according to a level of a hydraulic pressure flowing from the hydraulic-pressure supply device to the wheel cylinders, and controls the low-pressure mode and the high-pressure mode to be sequentially carried out according to the level of the hydraulic pressure flowing from the hydraulic-pressure supply device to the wheel cylinders.

24. The method according to claim 23, wherein the low-pressure mode includes:

opening the second valve; and

supplying a hydraulic pressure formed in the first pressure chamber by forward movement of the hydraulic piston, to the first hydraulic circuit and the second hydraulic circuit.

25. The method according to claim 24, wherein the high-pressure mode includes:

opening the second valve;

after lapse of the low-pressure mode, supplying some parts of the hydraulic pressure formed in the first pressure chamber by forward movement of the hydraulic piston, to the first hydraulic circuit and the second hydraulic circuit;

opening the fourth valve; and

supplying some parts of a remaining hydraulic pressure of the hydraulic pressure formed in the first pressure chamber to the second pressure chamber.

26. A method for operating the electronic brake system according to claim 4, the method comprising:

performing a normal operation mode provided with a regenerative braking mode in which two wheel cylinders provided at the first hydraulic circuit perform a regenerative braking mode using the generator,

wherein the regenerative braking mode closes the second valve and thus prevents a hydraulic pressure from flowing into the first hydraulic circuit.

27. A method for operating the electronic brake system according to claim 10, the method comprising:

performing an abnormal operation mode,

wherein the abnormal operation mode includes;

opening the first cut valve in a manner that the first master chamber communicates with the first hydraulic circuit, and

opening the second cut valve in a manner that the second master chamber communicates with the second hydraulic circuit.

28. A method for operating the electronic brake system according to claim 7, the method comprising:

performing a normal operation mode,

wherein the normal operation mode includes;

opening the simulator valve, and

generating a displacement of the simulation piston by the pressure medium discharged from the first master chamber, and allowing the pressure medium stored in the simulation chamber to flow into the reservoir through the reservoir passage.

29. A method for operating the electronic brake system according to claim 10, the method comprising:

performing an inspection mode in which presence or absence of a leak in the master cylinder or in the simulator valve is confirmed,

wherein the inspection mode includes;

closing the simulator valve and the second cut valve, and opening the first cut valve;

supplying a hydraulic pressure generated by activation of the hydraulic-pressure supply device to the first master chamber, and

comparing an estimated pressing-medium hydraulic pressure value scheduled to be generated based on a displacement of the hydraulic piston with a hydraulic pressure value of the pressure medium supplied to the first master chamber.

30. A method for operating the electronic brake system according to claim 15, the method comprising:

performing a normal operation mode,

wherein the normal operation mode is classified into a low-pressure mode for providing a relatively low hydraulic pressure and a high-pressure mode for providing a relatively high hydraulic pressure according to a level of a hydraulic pressure flowing from the hydraulic-pressure supply device to the wheel cylinders, and controls the low-pressure mode and the high-pressure mode to be sequentially carried out according to the level of the hydraulic pressure flowing from the hydraulic-pressure supply device to the wheel cylinders.

31. The method according to claim 30, wherein the low-pressure mode includes:

opening the fourth and fifth valves; and

supplying a hydraulic pressure formed in the first pressure chamber by forward movement of the hydraulic piston, to the first hydraulic circuit and the second hydraulic circuit.

32. The method according to claim 31, wherein the high-pressure mode includes:

opening the fourth and fifth valves;

after lapse of the low-pressure mode, supplying some parts of the hydraulic pressure formed in the first pressure chamber by forward movement of the hydraulic piston, to the first hydraulic circuit and the second hydraulic circuit;

opening the third valve; and

supplying some parts of a remaining hydraulic pressure of the hydraulic pressure formed in the first pressure chamber, to the second pressure chamber.

33. A method for operating the electronic brake system according to claim 17, the method comprising:

performing a normal operation mode,

wherein the normal operation mode is classified into a low-pressure mode for providing a relatively low hydraulic pressure and a high-pressure mode for providing a relatively high hydraulic pressure according to a level of a hydraulic pressure flowing from the hydraulic-pressure supply device to the wheel cylinders, and controls the low-pressure mode and the high-pressure mode to be sequentially carried out according to the level of the hydraulic pressure flowing from the hydraulic-pressure supply device to the wheel cylinders.

34. The method according to claim 33, wherein the low-pressure mode includes:

opening the sixth valve; and

supplying a hydraulic pressures formed in the first pressure chamber by forward movement of the hydraulic piston, to the first hydraulic circuit and the second hydraulic circuit.

35. The method according to claim 34, wherein the high-pressure mode includes:

opening the sixth valve;

after lapse of the low-pressure mode, supplying some parts of the hydraulic pressure formed in the first pressure chamber by forward movement of the hydraulic piston, to the first hydraulic circuit and the second hydraulic circuit;

opening the third valve; and

supplying some parts of a remaining hydraulic pressure of the hydraulic pressure formed in the first pressure chamber to the second pressure chamber.

36. A method for operating the electronic brake system according to claim 20, the method comprising:

performing a normal operation mode provided with a regenerative braking mode in which two wheel cylinders provided at the first hydraulic circuit perform a regenerative braking mode using the generator,

wherein the regenerative braking mode closes the eighth valve and thus prevents a hydraulic pressure from flowing into the first hydraulic circuit.