Hydraulic system for an agricultural implement incorporating implement-based hydraulic load sensing

Patent metadata

Field	Value
Publication number	US-10820470-B2
Application number	US-201816111572-A
Country	US
Kind code	B2
Filing date	Aug 24, 2018
Priority date	Aug 24, 2018
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A hydraulic system includes a supply line, at least one implement-based control valve, an implement-based pressure regulating valve, and a load sensing circuit. The implement-based control valve(s) is fluidly coupled to the supply line and configured to regulate a flow of the pressurized hydraulic fluid supplied through at least one downstream actuator line to at least one hydraulic actuator of the implement. The implement-based pressure regulating valve is fluidly coupled to the supply line upstream of the control valve(s) and configured to regulate a fluid pressure to be equal to or greater than a minimum fluid pressure. The load sensing circuit is fluidly coupled to the pressure regulating valve and provides a line or load pressure to the pressure regulating valve. The pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid based on the line pressure.

First claim

What is claimed is:

1. A hydraulic system for regulating the pressure of hydraulic fluid supplied to actuators of an agricultural implement, the hydraulic system comprising:
a supply line configured to receive pressurized hydraulic fluid from a fluid source;
at least one implement-based control valve fluidly coupled to the supply line, the at least one control valve configured to regulate a flow of the pressurized hydraulic fluid received from the supply line and supplied through at least one downstream actuator line to at least one hydraulic actuator of the implement;
an implement-based pressure regulating valve fluidly coupled to the supply line upstream of the at least one control valve, the pressure regulating valve being configured to regulate a fluid pressure of the pressurized hydraulic fluid supplied to the at least one control valve through the supply line such that the fluid pressure is equal to or greater than a minimum fluid pressure; and
a load sensing circuit fluidly coupled to the pressure regulating valve, the load sensing circuit providing a line pressure associated with the at least one downstream actuator line to the pressure regulating valve when the at least one control valve is supplying the pressurized hydraulic fluid through the at least one downstream actuator line to the at least one hydraulic actuator,
wherein, when the line pressure associated with the at least one downstream actuator line is greater than the minimum fluid pressure, the pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid to the at least one control valve such that the fluid pressure is equal to a pressure associated with the line pressure.

2. The hydraulic system of claim 1 , wherein, when the line pressure associated with the at least one downstream actuator line is equal to zero, the pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid to the at least one control valve such that the fluid pressure is equal to the minimum fluid pressure.

3. The hydraulic system of claim 1 , wherein the supply line is configured to receive pressurized hydraulic fluid from the fluid source up to a maximum source pressure greater than the minimum fluid pressure, the pressure regulating valve being configured to divert a portion of the pressurized hydraulic fluid to a return line when the line pressure associated with the at least one downstream actuator line is less than the maximum source pressure.

4. The hydraulic system of claim 3 , wherein the pressure regulating valve is configured to regulate the fluid pressure between the maximum source pressure and the minimum fluid pressure based on the line pressure associated with the at least one downstream actuator line.

5. The hydraulic system of claim 1 , wherein the load sensing circuit comprises a load sensing line fluidly coupled to the pressure regulating valve, the load sensing line being coupled to the pressure regulating valve as a pilot line to actuate the pressure regulating valve such that the fluid pressure is equal to a pressure associated with the line pressure.

6. The hydraulic system of claim 5 , wherein the at least one downstream actuator line comprises a plurality of downstream actuator lines and the at least one hydraulic actuator comprises a plurality of hydraulic actuators, each downstream actuator line being fluidly coupled to a respective hydraulic actuator of the plurality of hydraulic actuators.

7. The hydraulic system of claim 6 , wherein the load sensing circuit further comprises a plurality of shuttle valves fluidly coupled in series to the load sensing line, each shuttle valve including an input port fluidly coupled to a respective downstream actuator line of the plurality of downstream actuator lines such that the line pressure provided through the load sensing line corresponds to a maximum pressure associated with the plurality of downstream actuator lines.

8. The hydraulic system of claim 6 , wherein the at least one control valve comprises a plurality of control valves, each control valve being configured to regulate the flow of the pressurized hydraulic fluid supplied through a respective downstream actuator line of the plurality of downstream actuator lines.

9. The hydraulic system of claim 1 , wherein the fluid source is a fixed displacement pump.

10. An agricultural implement, comprising:
a frame;
a plurality of ground-engaging tools supported by the frame;
at least one hydraulic actuator supported by the frame, the at least one hydraulic actuator being configured to raise and lower at least one of the ground-engaging tools relative to a soil surface;
a supply line configured to receive pressurized hydraulic fluid;
at least one control valve fluidly coupled to the supply line, the at least one control valve configured to regulate a flow of the pressurized hydraulic fluid received from the supply line and supplied through at least one downstream actuator line to the at least one hydraulic actuator;
a pressure regulating valve fluidly coupled to the supply line upstream of the at least one control valve, the pressure regulating valve being configured to regulate a fluid pressure of the pressurized hydraulic fluid supplied to the at least one control valve through the supply line such that the fluid pressure is equal to or greater than a minimum fluid pressure; and
a load sensing circuit fluidly coupled to the pressure regulating valve, the load sensing circuit providing a line pressure associated with the at least one downstream actuator line to the pressure regulating valve when the at least one control valve is supplying the pressurized hydraulic fluid through the at least one downstream actuator line to the at least one hydraulic actuator,
wherein, when the line pressure associated with the at least one downstream actuator line is greater than the minimum fluid pressure, the pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid to the at least one control valve such that the fluid pressure is equal to a pressure associated with the line pressure.

11. The implement of claim 10 , wherein, when the line pressure associated with the at least one downstream actuator line is equal to zero, the pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid to the at least one control valve such that the fluid pressure is equal to the minimum fluid pressure.

12. The implement of claim 10 , wherein the supply line is configured to receive pressurized hydraulic fluid up to a maximum source pressure greater than the minimum fluid pressure, the pressure regulating valve being configured to divert a portion of the pressurized hydraulic fluid to a return line when the line pressure associated with the at least one downstream actuator line is less than the maximum source pressure.

13. The implement of claim 12 , wherein the pressure regulating valve is configured to regulate the fluid pressure between the maximum source pressure and the minimum fluid pressure based on the line pressure associated with the at least one downstream actuator line.

14. The implement of claim 10 , wherein the load sensing circuit comprises a load sensing line fluidly coupled to the pressure regulating valve, the load sensing line being coupled to the pressure regulating valve as a pilot line to actuate the pressure regulating valve such that the fluid pressure is equal to a pressure associated with the line pressure.

15. The implement of claim 14 , wherein the at least one downstream actuator line comprises a plurality of downstr

Assignees

• Cnh Ind America Llc

Inventors

• Wu Duqiang
• Endsley John C
• Glennon Michael
• Mckee Kevin D

Classifications

• F15B13/028

  Shuttle valves · CPC title

• A01B63/32 Primary

  operated by hydraulic or pneumatic means {without automatic control} · CPC title

• A01B63/10

  operated by hydraulic or pneumatic means · CPC title

• F15B2211/50554

  the pressure control means controlling a pressure downstream of the pressure control means, e.g. pressure reducing valve · CPC title

• F15B2211/528

  actuated by fluid pressure · CPC title