Dual line hydraulic trailer brake control circuit and method of control thereof

Patent metadata

Field	Value
Publication number	US-10166956-B2
Application number	US-201615222088-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Jul 28, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A method of detecting a leak in a hydraulic trailer brake circuit of a trailer includes providing a controller, a base valve, a first sensor, a second sensor, a control valve having a solenoid, a reduction valve, a hydraulic fluid supply, a first brake output, and a second brake output. The method also includes supplying a first pressure to an inlet of the base valve and outputting a second pressure from an outlet of the base valve to the first brake output. The first pressure is detected by the first sensor and the second pressure is detected by the second sensor, and the detected first and second pressures are communicated to the controller. The difference between the first and second pressures are compared to a threshold, and a leak is detected in the hydraulic trailer brake circuit if the difference satisfies the threshold.

First claim

The invention claimed is:

1. A hydraulic braking system of a trailer, comprising:
a pressurized supply of hydraulic fluid;
a base valve including an inlet and an outlet;
a control valve including a solenoid, an inlet fluidly coupled to the pressurized supply of hydraulic fluid, and an outlet, the control valve operably controlled between an energized state and a de-energized state;
a first brake output fluidly coupled to the outlet of the base valve;
a second brake output fluidly coupled to the outlet of the control valve;
a first sensor and a second sensor fluidly coupled to the base valve, the first sensor configured to detect a first pressure at the inlet of the base valve along an inlet line separate from the first brake output, and the second sensor configured to detect a second pressure at the outlet of the base valve;
wherein, the control valve is operably controlled to its de-energized state when a difference between the first pressure and second pressure satisfies a threshold.

2. The braking system of claim 1 , wherein in the de-energized state the pressurized supply is fluidly coupled to the second brake output, and in the energized state the control valve fluidly de-couples the pressurized supply from the second brake output.

3. The braking system of claim 1 , further comprising:
a controller disposed in electrical communication with the first and second sensors,
wherein the base valve comprises a fixed gain and the controller compares the first pressure as a function of the fixed gain to the second pressure to determine the difference and whether to operably control the control valve to its energized state or de-energized state.

4. The hydraulic braking system of claim 3 , wherein the fixed gain comprises a gain of 3.0.

5. The braking system of claim 1 , further comprising a reduction valve fluidly coupled between the pressurized supply and the control valve, wherein the reduction valve is configured to reduce an amount of fluid pressure supplied by the pressurized supply to the control valve.

6. The hydraulic braking system of claim 5 , wherein the reduction valve is configured to reduce the fluid pressure supplied by the pressurized supply to the control valve to less than 50 bar.

7. The hydraulic braking system of claim 6 , wherein the reduction valve is configured to reduce the fluid pressure supplied by the pressurized supply to the control valve to less than 40 bar.

8. The hydraulic braking system of claim 7 , wherein the reduction valve is configured to reduce the fluid pressure supplied by the pressurized supply to the control valve to between 15-35 bar.

9. The braking system of claim 1 , further comprising a park brake hydraulically controlled by the second brake output between a disengaged position and an engaged position, wherein in the de-energized state the park brake is in its disengaged position, and in the energized state the park brake is in its engaged position.

10. The hydraulic braking system of claim 1 , further comprising a third sensor fluidly coupled to the control valve, the third sensor configured to detect an output pressure in the second brake output.

11. The hydraulic braking system of claim 1 , wherein the control valve is operably controlled to its de-energized state when a difference between the first pressure and the second pressure exceeds the threshold.

12. A hydraulic braking system of a trailer towed by a work machine, comprising:
a controller;
a pressurized supply providing hydraulic fluid;
a pilot line providing a pilot pressure;
a base valve including a first inlet, a second inlet, and an outlet, where the first inlet is fluidly coupled to the pilot line and the second inlet is fluidly coupled to the pressurized supply;
a solenoid control valve disposed in electrical communication with the controller and including an inlet fluidly coupled to the pressurized supply of hydraulic fluid and an outlet, the solenoid control valve operably controlled between an energized state and a de-energized state by the controller;
a reduction valve fluidly coupled between the pressurized supply and the solenoid control valve, wherein the reduction valve is configured to reduce an amount of fluid pressure supplied by the pressurized supply to the solenoid control valve;
a first control line fluidly coupled to the outlet of the base valve;
a second control line fluidly coupled to the outlet of the solenoid control valve;
a first sensor and a second sensor fluidly coupled to the base valve, the first sensor configured to detect pilot pressure, and the second sensor configured to detect an output pressure in the first control line; and
a third sensor fluidly coupled to the solenoid control valve, the third sensor configured to detect an output pressure in the second control line,
wherein, the solenoid control valve is operably controlled to its energized state when a difference between the pilot pressure and output pressure satisfies a threshold.

13. The hydraulic braking system of claim 12 , wherein:
in the energized state the pressurized supply is fluidly coupled to the second control line, and in the de-energized state the solenoid control valve fluidly de-couples the pressurized supply from the second control line.

14. The hydraulic braking system of claim 12 , further comprising a park brake hydraulically controlled by the solenoid control valve between a disengaged position and an engaged position, wherein in the energized state the park brake is in its disengaged position, and in the de-energized state the park brake is in its engaged position.

15. The hydraulic braking system of claim 12 , wherein the solenoid control valve is operably controlled to its de-energized state when the difference between the pilot pressure and the output pressure exceeds the threshold.

16. The hydraulic braking system of claim 12 , wherein the base valve comprises a fixed gain of 3.0 and the controller compares the pilot pressure as a function of the fixed gain to the output pressure to determine the difference and whether to operably control the control valve to its energized state or de-energized state.

17. The hydraulic braking system of claim 12 , wherein the reduction valve is configured to reduce the fluid pressure supplied by the pressurized supply to the solenoid control valve to less than 50 bar.

18. The hydraulic braking system of claim 17 , wherein the reduction valve is configured to reduce the fluid pressure supplied by the pressurized supply to the solenoid control valve to less than 40 bar.

19. The hydraulic braking system of claim 18 , wherein the reduction valve is configured to reduce the fluid pressure supplied by the pressurized supply to the solenoid control valve to between 15-35 bar.

Assignees

• Deere & Co

Inventors

• Schick Troy E
• Pence Ryan A
• Mcmillen Brandon J
• Quinn Aaron M

Classifications

• B60T17/226

  using devices being responsive to the difference between the fluid pressions in conduits of multiple braking systems · CPC title

• B60T2270/403

  Brake circuit failure · CPC title

• B60T13/12 Primary

  the fluid being liquid · CPC title

• B60T15/027

  in pneumatic systems · CPC title

• B60T17/221

  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 title