Method for controlling a hydraulic top link of a three-point linkage

Patent metadata

Field	Value
Publication number	US-2019265737-A1
Application number	US-201916281753-A
Country	US
Kind code	A1
Filing date	Feb 21, 2019
Priority date	Feb 28, 2018
Publication date	Aug 29, 2019
Grant date	—

Abstract

A method is provided for controlling a hydraulic top link of a three-point linkage on a piece of accessory equipment coupled to a tractor. The method includes providing the top link coupled between a first location on the tractor and a second location on the accessory equipment. A control unit, at least one sensor and an electric hydraulic control are provided. The method includes defining an extension position of the top link as a distance between the first location and the second location, where the extension position is adjustable within a predetermined adjustment range. The method further includes determining a force acting on the top link and adjusting the extension position of the top link by the control unit as a function of the force acting on the top link.

First claim

1 . A method for controlling a hydraulic top link of a three-point linkage on a piece of accessory equipment coupled to a tractor, comprising:
providing the top link coupled between a first location on the tractor and a second location on the accessory equipment; providing a control unit, at least one sensor, and an electric hydraulic control; defining an extension position of the top link as a distance between the first location and the second location, where the extension position is adjustable within a predetermined adjustment range; determining a force acting on the top link; and adjusting the extension position of the top link by the control unit as a function of the force acting on the top link.

2 . The method of claim 1 , further comprising determining an initial extension position of the top link as a function of a longitudinal force exerted on the top link by the accessory equipment, where the longitudinal force is defined by a predefined characteristic curve.

3 . The method of claim 2 , further comprising modifying the predefined characteristic curve by the control unit as a function of topographical information.

4 . The method of claim 3 , further comprising:
obtaining the topographical information via a global-positioning sensor; and communicating the topographical information to the control unit.

5 . The method of claim 3 , wherein the modifying step comprises adjusting a driving tractive force exerted on the accessory equipment via the three-point linkage if the control unit determines that the topographical information is indicative of the accessory equipment is operating on level ground.

6 . The method of claim 1 , further comprising:
detecting a change in a lifting height of the three-point linkage by the control unit; and holding the top link in its current extension position.

7 . The method of claim 1 , further comprising detecting an initial extension position of the top link by a position sensor and communicating the initial position to the control unit.

8 . The method of claim 1 , further comprising controlling a lifting height of the three-point linkage by adjusting a lift cylinder and the extension position of the top link.

9 . The method of claim 1 , further comprising detecting a force acting on the top link with the at least one sensor.

10 . The method of claim 1 , further comprising performing the adjusting step as a function of a setpoint value predetermined for the force acting on the top link.

11 . The method of claim 1 , wherein the adjusting step comprises adjusting the top link within its predetermined adjustment range as a function of a minimum force value predetermined for the force acting on the top link.

12 . The method of claim 1 , further comprising coupling the top link to an oblong hole on the accessory equipment where the oblong hole comprises a first end and a second end, where a minimum position within the predetermined adjustment range is defined at the first end and a maximum position within the predetermined adjustment range is defined at the second end.

13 . The method of claim 12 , further comprising operably adjusting the extension position of the top link by the control unit such that the top link is coupled to the first end of the oblong hole.

14 . The method of claim 1 , further comprising actuating the electric hydraulic control to controllably move the top link from its current extension position to an adjusted position within the predetermined adjustment range.

15 . An agricultural vehicle system, comprising:
a tractor; an accessory equipment coupled to the tractor via a three-point linkage, the accessory equipment configured to perform a work function; a top link of the three-point linkage coupled at a first location to the tractor and a second location to the accessory equipment, the top link comprising an adjustable extension length defined between the first location and the second location; and a control unit for operably controlling the extension length of the top link within a predetermined adjustment range; wherein, the control unit operably adjusts the extension length of the top link within the predetermined adjustment range as a function of a force acting on the top link.

16 . The system of claim 15 , further comprising:
a global-positioning sensor adapted to detect topographical information and communicate the topographical information to the control unit; and a predefined characteristic curve stored in a database and adapted to be modified by the control unit, the predefined characteric curve defining an initial extension length of the top link; wherein, the predefined characteristic curve is adjustable by the control unit based on the topographical information; further wherein, the initial extension length of the top link is set by the control link within the predetermined adjustable range based on the predefined characteristic curve.

17 . The system of claim 15 , further comprising at least one lifting cylinder for operably adjusting a lifting height of the three-point linkage;
wherein, if the lifting height is adjusted by the at least one lifting cylinder, the control unit operably maintains the top link at its current extension length.

18 . The system of claim 15 , further comprising:
a position sensor disposed in communication with the control unit, the position sensor configured to detect a current extension length of the top link; and a pressure sensor disposed in communication with the control unit, the pressure sensor configured to detect the force acting on the top link; wherein, the control unit operably adjusts the extension length of the top link from its current extension length to a new extension length based on the forced detected by the pressure sensor.

19 . The system of claim 15 , wherein the second location comprises a fixed hole and a slot, the top link being coupled to the accessory equipment to either the fixed hole or the slot;
wherein, the slot comprises a first end and a second end, the first end being disposed nearest the tractor; wherein, the control unit operably adjusts the extension length of the top link to maintain the top link in a coupled position within the slot at the first end.

20 . A method for controlling a top link of a three-point linkage coupled between a tractor and an accessory equipment, comprising:
coupling the top link to the tractor at a first location and the accessory equipment at a second location, where the top link is either fixedly coupled or adjustably coupled at the second location; providing a control unit for controlling an extension length of the top link, the extension length defined as a distance between the first location and the second location, where the extension length is adjustable within a predetermined adjustment range; determining a force acting on the top link; operating in at least one of a first operating mode, a second operating mode, and a third operating mode; and adjusting the extension position of the top link by the control unit as a function of the force acting on the top link; wherein: in the first operating mode, the extension length of the top link is adjusted based on the force determined by a pressure sensor; in the second operating mode, the extension length of the top link is adjusted based on a predetermined setpoint force value acting on the top link; and in the third operating mode, the extension length of the top link is adjusted based on a predetermined minimum force value when the top link

Assignees

• Deere & Co

Inventors

• Gresch Valentin
• Reinmuth Florian

Classifications

• A01B63/111

  regulating working depth of implements · CPC title

• A01B59/068

  the lower arms being lifted or lowered by power actuator means provided externally on the tractor · CPC title

• G05D3/12 Primary

  using feedback · CPC title

• A01B63/112 Primary

  to control draught load, i.e. tractive force · CPC title