Hydraulic work unit leveling and calibration system for an agricultural implement

Patent metadata

Field	Value
Publication number	US-9615499-B2
Application number	US-201414559227-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 3, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

An agricultural implement has a depth control system in which a position sensor directly measures linear translation of a hydraulic cylinder that lifts and lowers a work unit on an implement frame to set and adjust the depth of the work unit without the use of a rockshaft. The position sensor may be positioned adjacent to or integrally formed with the hydraulic cylinder, and provides a voltage to a controller remote from the implement. The controller automatically adjusts the flow of hydraulic fluid to and from the hydraulic cylinder to maintain the depth of each work unit at an operator-selected level and can be used to calibrate the actual position of multiple work units relative to the frame and to one another.

First claim

We claim:

1. An agricultural machine transportable in a agricultural field, comprising:
a frame;
a plurality of farming related work units pivotally coupled to the frame;
a number of cylinders coupled between the frame and each of the work units, each cylinder configured to raise and lower a corresponding work unit relative to the frame and to other work units to adjust a depth of the corresponding work unit;
a fluid reservoir operably connected to each of the number of cylinders;
a number of fluid flow valves operably connected between the fluid reservoir and each of the cylinders to control the flow of fluid between the reservoir and the cylinders;
a position sensor associated with each cylinder and configured to measure a linear displacement of each cylinder and output a signal indicative of a depth of the work unit associated with the cylinder; and
a controller operably connected to the position sensors and the fluid flow valves associated with each cylinder, the controller operable to selectively direct the flow of fluid between the reservoir and each valve automatically in response to the signal from the position sensor for the associated cylinder to selectively raise and lower each work unit relative to the frame independently of the other work units during transport of the agricultural implement through the agricultural field.

2. The agricultural machine of claim 1 wherein the position sensor is a linear potentiometer instrument.

3. The agricultural machine of claim 2 wherein the linear potentiometer instrument is configured to output a signal having a voltage that changes with linear displacement of the cylinder.

4. The machine of claim 1 wherein the work units are seed or fertilizer dispensers.

5. The machine of claim 1 wherein the work units are soil preparation devices.

6. The machine of claim 1 wherein the work units are wheel sets.

7. The machine of claim 1 wherein the controller is further configured to control the flow of fluid to the cylinder to minimize a difference between an instantaneous value of a parameter measured by the sensor and a set point value for the parameter.

8. The machine of claim 1 further comprising operator controls operably connected to the controller to allow an operator to vary the depth of the work units.

9. The machine of claim 1 further comprising a database operably connected to the controller and configured to store baseline signals for comparison with the output signals from the position sensors.

10. The machine of claim 9 wherein the baseline signals stored in the database are rewritable.

11. A method of controlling the depths of first and second agricultural work units of a plurality of agricultural work units operably connected to a frame, the frame being transportable through an agricultural field, comprising:
providing a stored first set-point value for a baseline position of the first work unit;
measuring a linear translation of a first hydraulic cylinder coupled between the first work unit and the frame and configured to raise and lower the first work unit;
providing a first measured value based on the linear translation of the first hydraulic cylinder;
comparing the first measured value to the first set-point value;
controlling hydraulic fluid flow to and from the first hydraulic cylinder based on the comparison to reduce a difference between the first measured value and the first set-point value so as to automatically adjust the depth of the first agricultural work unit independently of the other of the plurality of agricultural work units during transport of the frame through the agricultural field;
providing a stored second set-point value for a baseline position of the second work unit;
measuring a linear translation of a second hydraulic cylinder coupled between the second work unit and the frame and configured to raise and lower the second work unit;
providing a second measured value based on the linear translation of the second hydraulic cylinder;
comparing the second measured value to the second set-point value; and
controlling hydraulic fluid flow to and from the second hydraulic cylinder based on the comparison to reduce a difference between the second measured value and the second set-point value so as automatically to adjust the depth of the second agricultural work unit independently of the other of the plurality of agricultural work units during transport the frame through the agricultural field.

12. The method of claim 11 wherein the step of providing the stored first set-point value comprises calibrating the stored first set-point value.

13. The method of claim 11 wherein the step of calibrating the stored first set-point value comprises:
selecting a position for the first work unit associated with a stored value using a controller operably connected to the first hydraulic cylinder associated with the first work unit;
comparing the selected position to an actual position of the first work unit; and
adjusting the stored value for the selected position of the first work unit to correspond to a measured value for the actual position of the first work unit.

14. The method of claim 13 wherein the stored value is the first set-point value.

15. The method of claim 13 further comprising the step of adjusting a stored value for the second work unit after adjusting the stored value of the selected position for the first work unit.

16. The method of claim 15 wherein the step of adjusting the stored value for the second work unit comprises adjusting the stored value for the selected position of the second work unit to correspond to a measured value for the actual position of the first work unit.

Assignees

• Cnh Ind Canada Ltd
• Cnh Ind Canada Ltd

Inventors

• Kowalchuk Trevor
• Ryder Nick

Classifications

• A01B63/22 Primary

  operated by hydraulic or pneumatic means · CPC title

• A01C7/10

  Devices for adjusting the seed-box {; Regulation of machines for depositing quantities at intervals} · CPC title

• A01C7/203

  comprising depth regulation means · CPC title