Electro-hydraulic steering control system

Patent metadata

Field	Value
Publication number	US-10668947-B2
Application number	US-201715477705-A
Country	US
Kind code	B2
Filing date	Apr 3, 2017
Priority date	Apr 3, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A steering system for a work vehicle having a steerable wheel. The steering system includes a steering input device configured to provide a first steering input and a second steering input to move the steerable wheel. A pilot system is operatively connected to the steering input device and includes a first pilot line operatively connected to the first steering input and a second pilot line operatively connected to the second steering input. A piloted system is operatively connected to the pilot system and includes a direction control valve operatively connected to each of the first and second pilot lines and to a steering cylinder. The steering cylinder is coupled to the steerable wheel. The direction control valve responds to each of the pressure signals of the first and second pilot lines to adjust the position of the steering cylinder which in turn moves the steerable wheel.

First claim

The invention claimed is:

1. A steering system for a work vehicle having to steerable wheel, the steering system comprising:
a steering input device configured to provide a steering input to move the steerable wheel;
a pilot system operatively connected to the steering input device, the pilot system including a first metering valve, a second metering valve, and a pilot line operatively connected to the first metering valve, to the second metering valve, and to the steering input device;
a piloted system including a direction control valve, operatively connected to the pilot line, and having a piloted control valve output;
a steering cylinder operatively connected to the steerable wheel and to the piloted control valve output, wherein the steering cylinder is configured to move the steerable wheel in response to the piloted control valve output, and
a steering command angle sensor operatively connected to the steering input device, a valve position sensor operatively connected to the direction control valve, and one of a cylinder position sensor operatively connected to the steering cylinder and a steered wheel angle sensor, wherein each of the steering command angle sensor, the valve position sensor, the cylinder position sensor, and the steered wheel angle sensor provides a signal configured to adjust a position of the first metering pilot valve and a position of the second metering pilot valve.

2. The steering system of claim 1 wherein the pilot line includes a first pilot line and a second pilot line, each operatively connected to the steering input, wherein the first pilot line is operatively connected to a first pilot area of the direction control valve and the second pilot line is operatively connected to a second pilot area of the direction control valve.

3. The steering system of claim 2 wherein the first metering valve is operatively connected to the first pilot line and the second metering valve is operatively connected to the second pilot line, wherein the first metering valve is normally open or normally closed and the second metering valve is normally open or normally closed.

4. The steering system of claim 3 wherein the first metering valve and the second metering valve are configured to adjust a first fluid pressure in the first pilot line in response to the steering input and the first metering valve and the second metering valve are configured to adjust a second fluid pressure in the second pilot line in response to the steering input.

5. The steering system of claim 4 wherein the piloted system includes a first pressure control valve operatively connected to the first pilot line and to a first pilot area of the direction control valve and a second pressure control valve operatively connected to the second pilot line and to a second pilot area of the direction control valve.

6. The steering system of claim 5 comprising a high pressure source of high pressure fluid, wherein the first pressure control valve, the second pressure control valve, and the direction control valve are operatively connected to the high pressure source.

7. The steering system of claim 3 further comprising a first flow control valve having a first control line and a second flow control valve having a second control line and the direction control valve further includes a third pilot area operatively connected to the first control line and fourth pilot area operatively connected to the second control line.

8. The steering system of claim 7 further comprising a controller operatively connected to the first metering pilot valve, the second metering pilot valve, the first flow control valve and the second flow control valve, wherein the controller includes a processor and a memory wherein the memory is configured to store program instructions and the processor is configured to execute the stored program instructions to:
identify one of a manual control mode and an external control mode; and
activate both of the first metering pilot valve and the second metering pilot valve or both of the first flow control valve and the second flow control valve in response to the identified control mode.

9. The steering system of claim 8 further comprising a steering command angle sensor operatively connected to the steering input device, a valve position sensor operatively connected to the direction control valve, and a cylinder position sensor operatively connected to the steering cylinder, wherein each of the steering command angle sensor, the valve position sensor, and the cylinder position sensor provide a signal to the controller to adjust a position of the first flow control valve and a position of the second flow control valve.

10. A work vehicle comprising:
a steerable wheel;
a steering input device configured to provide a steering input to move the steerable wheel;
a steering system, operatively connected to the steerable wheel and the steering input device, wherein the steering system includes a pilot system operatively connected to the steering input device, the pilot system including a first pilot line and a second pilot line each operatively connected to the steering input device and a first metering pilot valve operatively connected to the first pilot line and a second metering pilot valve operatively connected to the second pilot line, a piloted system including a direction control valve, operatively connected to the pilot line, and having a piloted control valve output, and a steering cylinder operatively connected to the steerable wheel and to the piloted control valve output, wherein the steering cylinder is configured to move the steerable wheel in response to the piloted control valve output, and
a steering command angle sensor operatively connected to the steering input device, a valve position sensor operatively connected to the direction control valve, and one of a cylinder position sensor operatively connected to the steering cylinder and a steered wheel angle sensor, wherein each of the steering command angle sensor, the valve position sensor, the cylinder position sensor, and the steered wheel angle sensor provides a signal configured to adjust a position of the first metering pilot valve and a position of the second metering pilot valve.

11. The work vehicle of claim 10 wherein the first pilot line is operatively connected to a first pilot area of the direction control valve and the second pilot line is operatively connected to a second pilot area of the direction control valve.

12. The work vehicle of claim 11 wherein one of the first metering pilot valve and the second metering pilot valve is normally open and the other of the first metering pilot valve and the second metering pilot valve is normally closed.

13. The work vehicle of claim 12 wherein the first metering pilot valve and the second metering pilot valve are configured to adjust a fluid pressure in the first pilot line in response to the steering input and the first metering pilot valve and the second metering pilot valve are configured to adjust a fluid pressure in the second pilot line in response to the steering input.

14. The work vehicle of claim 13 wherein the piloted system includes a first pressure control valve operatively connected to the first pilot line and to a first pilot area of the direction control valve and a second pressure control valve operatively connected to the second pilot line and to a second pilot area of the direction control valve.

15. A steering system for a work vehicle having a steerable wheel, the steering system comprising:
a steering input device configured to provide a first steering input configured to move the steera

Assignees

• Deere & Co

Inventors

• Eagles Derek M

Classifications

• B62D6/007

  adjustable by the driver, e.g. sport mode · CPC title

• B62D5/093 Primary

  Telemotor driven by steering wheel movement (hydraulic steering gear B62D3/14) · CPC title

• B62D5/09 Primary

  characterised by means for actuating valves · CPC title

• B62D1/22

  Alternative steering-control elements, e.g. for teaching purposes · CPC title

• B62D5/06 Primary

  fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle · CPC title