System for providing speed-dependent control of a brake of a hauled unit of a work vehicle and related valve assembly

Patent metadata

Field	Value
Publication number	US-9873415-B2
Application number	US-201615050526-A
Country	US
Kind code	B2
Filing date	Feb 23, 2016
Priority date	Feb 23, 2016
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A system for controlling a brake of a unit hauled by a work vehicle may generally include a valve assembly. When a speed of the work vehicle exceeds a predetermined speed threshold, the valve assembly may be configured to allow the brake to be actuated when first and second brake pedals of the work vehicle are depressed, either individually or simultaneously. However, when the speed of the work vehicle is less than the predetermined speed threshold, the valve assembly may only be configured to allow the brake to be actuated when both of the first and second brake pedals are depressed simultaneously.

First claim

What is claimed is:

1. A system for controlling a brake of a unit hauled by a work vehicle, the system comprising:
a first brake pedal provided in operative association with a first input line;
a second brake pedal provided in operative association with a second input line;
a primary supply line provided in fluid communication with the first and second input lines;
a secondary supply line provided in fluid communication with the first input line;
a control valve provided between an output line and the primary and secondary supply lines, the control valve movable between a first position, wherein the output line is in fluid communication with the primary supply line, and a second position, wherein the output line is in fluid communication with the secondary supply line;
a secondary valve provided in operative association with the secondary supply line, the secondary valve configured to allow fluid to flow through the secondary supply line from the first input line to the control valve only when the second brake pedal is depressed, wherein the secondary valve corresponds to a pilot-operated check valve; and
a pilot line fluidly coupled between the second input line and the secondary valve,
wherein, when a speed of the work vehicle is greater than a predetermined speed threshold, the control valve is moved to the first position such that pressurized fluid is supplied to the output line from the primary supply line for actuating the brake of the unit hauled by the work vehicle when either the first brake pedal or the second brake pedal is depressed,
wherein, when the speed of the work vehicle is less than the predetermined speed threshold, the control valve is moved to the second position such that pressurized fluid is supplied to the output line from the secondary supply line for actuating the brake of the unit hauled by the work vehicle only when both of the first and second brake pedals are depressed,
wherein, when the second brake pedal is depressed, the pressurized fluid is supplied through the pilot line to actuate the secondary valve from a closed position to an opened position, and
wherein, when the second brake pedal is released, the secondary valve is returned to the closed position to prevent fluid from flowing through the secondary supply line to the control valve.

2. A system for controlling a brake of a unit hauled by a work vehicle, the system comprising:
a first brake pedal provided in operative association with a first input line;
a second brake pedal provided in operative association with a second input line;
a primary supply line provided in fluid communication with the first and second input lines;
a secondary supply line provided in fluid communication with the first input line;
a control valve provided between an output line and the primary and secondary supply lines, the control valve movable between a first position, wherein the output line is in fluid communication with the primary supply line, and a second position, wherein the output line is in fluid communication with the secondary supply line;
a secondary valve provided in operative association with the secondary supply line, the secondary valve configured to allow fluid to flow through the secondary supply line from the first input line to the control valve only when the second brake pedal is depressed; and
a brake valve in fluid communication with the output line, wherein the output line is fluidly coupled to a pilot actuator of the brake valve,
wherein, when a speed of the work vehicle is greater than a predetermined speed threshold, the control valve is moved to the first position such that pressurized fluid is supplied to the output line from the primary supply line for actuating the brake of the unit hauled by the work vehicle when either the first brake pedal or the second brake pedal is depressed,
wherein, when the speed of the work vehicle is less than the predetermined speed threshold, the control valve is moved to the second position such that pressurized fluid is supplied to the output line from the secondary supply line for actuating the brake of the unit hauled by the work vehicle only when both of the first and second brake pedals are depressed, and
wherein the brake valve is configured to actuate the brake of the unit hauled by the work vehicle when the pressurized fluid is supplied from the control valve through the output line.

3. The system of claim 1 , wherein the control valve corresponds to an electronically controlled valve, further comprising a controller coupled to the control valve that is configured to actuate the control valve between the first and second positions based on the speed of the work vehicle.

4. The system of claim 3 , wherein the controller is configured to monitor the speed of the work vehicle based on signals received from a speed sensor.

5. The system of claim 1 , further comprising a shuttle valve provided between the primary supply line and the first and second input lines.

6. The system of claim 5 , wherein the secondary supply line is fluidly coupled to the first supply line upstream of the shuttle valve.

7. The system of claim 1 , wherein the first input line is provided in fluid communication with a first service brake of the work vehicle.

8. The system of claim 1 , wherein the second input line is provided in fluid communication with a second service brake of the work vehicle.

9. A valve assembly for controlling the actuation of a brake of a unit hauled by a work vehicle, the work vehicle including a first brake pedal and a second brake pedal, the valve assembly comprising:
a primary supply line provided in fluid communication with both a first input line associated with the first brake pedal and a second input line associated with the second brake pedal;
a secondary supply line provided in fluid communication with the first input line;
a control valve provided between an output line and the primary and secondary supply lines, the control valve movable between a first position, wherein the output line is in fluid communication with the primary supply line, and a second position, wherein the output line is in fluid communication with the secondary supply line; and
a pilot-operated check valve provided in operative association with the secondary supply line, the pilot-operated check valve configured to be actuated from a closed position to an opened position to provide a flow path through the secondary supply line from the first input line to the control valve,
wherein, when either the first brake pedal or the second brake pedal is depressed, the pilot-operated check valve is maintained in the closed position such that pressurized fluid is directed to the control valve solely through the primary supply line,
wherein, when both the first and second brake pedals are depressed, the pilot-operated check valve is actuated to the opened position such that pressurized fluid is directed through the secondary supply line to the control valve.

10. The valve assembly of claim 9 , further comprising a pilot line fluidly coupled between the pilot-operated check valve and the second input line such that pressurized fluid is directed through the pilot line to actuate the pilot-operated check valve to the opened position when the second brake pedal is depressed.

11. The valve assembly of claim 10 , wherein, when the second brake pedal is released, the pilot-operated check valve is returned to the closed position to prevent fluid from flowing through the secondary supply line to the control valve.

12. The valve assembly of claim 9 , wherein the control valve comprises an electronically controlled valve.

13. The valve assembly of

Assignees

• Cnh Ind America Llc
• Cnh Ind America Llc

Inventors

• Hill Christopher
• Brinkley Jerry L
• Mccabe Kenneth

Classifications

• B60T11/21 Primary

  with two pedals operating on respective circuits, pressures therein being equalised when both pedals are operated together, e.g. for steering (steering non-deflectable wheels or endless tracks by differentially driving ground-engaging elements on opposite vehicle sides using brakes as main steering effecting means B62D11/08) · CPC title

• B60T7/06

  Disposition of pedal · CPC title

• B60T11/108

  to a trailer fluid system · CPC title

• B60T8/1708 Primary

  for lorries or tractor-trailer combinations · CPC title

• B62D11/08

  using brakes or clutches as main steering-effecting means · CPC title