SYSTEM AND METHOD FOR HYDRAULIC FLOW CONTROL

• US 20170241447A1
• Filed: 02/07/2017
• Published: 08/24/2017
• Est. Priority Date: 02/18/2016
• Status: Abandoned Application

• Current Assignee: AGCO International GmbH (AGCO International Holdings BV)
• Original Assignee: AGCO International GmbH (AGCO International Holdings BV)
• Inventors: Boulard, Nicolas
• Application Number:
  US15/426,933
• Publication Number:
  US 20170241447A1
• Time in Patent Office: Days
• CPC Class Codes: A01B 63/10 operated by hydraulic or pneumatic means
• CPC Class Codes: A01B 76/00 Parts, details or accessories of agricultural machines or implements, not provided for in groups A01B51/00 - A01B75/00
• CPC Class Codes: E02F 9/2228 including an electronic controller
• CPC Class Codes: F15B 11/10 in which the servomotor position is a function of the pressure also pressure regulators as operating means for such systems, the device itself may be a position indicating system
• CPC Class Codes: F15B 21/087 Control strategy, e.g. with block diagram
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/40515 with variable throttles or orifices
• CPC Class Codes: F15B 2211/426 electrically or electronically
• CPC Class Codes: F15B 2211/605 Load sensing circuits
• CPC Class Codes: F15B 2211/6309 the pressure being a pressure source supply pressure
• CPC Class Codes: F15B 2211/6313 the pressure being a load pressure
• CPC Class Codes: F15B 2211/632 representing a flow rate
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/6654 Flow rate control
• CPC Class Codes: G05D 7/005 characterised by the use of auxiliary non-electric power combined with the use of electric means
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence

Abstract

An agricultural system for hydraulic flow control having an adjustable hydraulic fluid valve arranged between a hydraulic reservoir and a hydraulic consumer, pressure is measured at the reservoir-facing side and at the consumer-facing side of the valve, from which the fluid flow through the valve can be determined. The valve can then be easily controlled to provide a desired fluid flow level, regardless of the type of hydraulic circuit used.

Claims

1. An agricultural system comprising:

an agricultural vehicle, preferably an agricultural tractor, having a hydraulic fluid tank;

a hydraulically-operated agricultural implement coupled to the agricultural vehicle;

an adjustable fluid valve connecting the hydraulic fluid tank with the agricultural implement;

a first fluid pressure sensor located at the tank-facing side of the fluid valve;

a second fluid pressure sensor located at the implement-facing side of the fluid valve; and

a controller coupled with the fluid valve and the first and second pressure sensors, the controller operable to adjust the fluid valve such that the flow rate to the implement is maintained at a desired flow rate, and wherein the controller is operable to determine the actual flow rate of hydraulic fluid through the fluid valve based on the output of the first and second pressure sensors,

wherein said agricultural implement is provided with an implement identifier, wherein the controller is operable to adjust the fluid valve based at least in part on said implement identifier.

2. The system of claim 1, wherein the adjustable fluid valve is a spool valve, and wherein the controller is operable to adjust a duty cycle of the spool valve.

3. The system of claim 1, wherein the hydraulic fluid tank is provided as part of a hydraulic circuit of the agricultural vehicle.

4. The system of claim 3, wherein the hydraulic circuit comprises a Load Sensing hydraulic circuit or an Open Centre hydraulic circuit.

5. The system of claim 1, wherein the agricultural system further comprises an input device coupled with said controller, wherein a desired flow rate of hydraulic fluid through the fluid valve to the implement can be defined using said input device.

6. The system of claim 1, wherein said implement identifier comprises a machine-readable element, arranged to be accessed by the controller.

7. The system of claim 1, wherein the agricultural vehicle comprises an adjustable hitch, wherein the implement is a hitch-mounted implement, and wherein the controller is operable to adjust the fluid valve to control the fluid flow rate based on the position of the adjustable hitch.

8. The system of claim 7, wherein the controller is operable to determine if the hitch is in a raised or in a lowered position, wherein the fluid flow rate is controlled based on the position of the hitch and the hitch-mounted implement.

9. The system of claim 8, wherein the controller is arranged to control the fluid valve to turn off fluid flow to the implement when the hitch is in a raised position.

10. The system of claim 1, wherein the vehicle comprises a releasable fluid connection through which the hydraulic tank is connected with the implement, wherein the second fluid pressure sensor is positioned to measure the fluid pressure between the adjustable fluid valve and the releasable connection.

11. The system of claim 1, wherein the controller is arranged to calculate the required valve opening size such that:

12. An agricultural system comprising:

an agricultural vehicle, preferably an agricultural tractor, having a hydraulic fluid tank;

a hydraulically-operated agricultural implement coupled to the agricultural vehicle;

an adjustable fluid valve connecting the hydraulic fluid tank with the agricultural implement;

a first fluid pressure sensor located at the tank-facing side of the fluid valve;

a second fluid pressure sensor located at the implement-facing side of the fluid valve; and

a controller coupled with the fluid valve and the first and second pressure sensors, the controller operable to adjust the fluid valve such that the flow rate to the implement is maintained at a desired flow rate, and wherein the controller is operable to determine the actual flow rate of hydraulic fluid through the fluid valve based on the output of the first and second pressure sensors,

wherein the agricultural vehicle comprises an adjustable hitch, wherein the implement is a hitch-mounted implement, and wherein the controller is operable to adjust the fluid valve to control the fluid flow rate based on the position of the adjustable hitch.

13. The system of claim 12, wherein the controller is operable to determine if the hitch is in a raised or in a lowered position, wherein the fluid flow rate is controlled based on the position of the hitch and the hitch-mounted implement.

14. The system of claim 13, wherein the controller is arranged to control the fluid valve to turn off fluid flow to the implement when the hitch is in a raised position.

15. A method of controlling the flow of hydraulic fluid between a hydraulic fluid tank and an agricultural implement through an adjustable fluid valve, the method comprising the steps of:

receiving a desired fluid flow rate for an agricultural implement;

measuring a first fluid pressure at the hydraulic tank-facing side of a fluid valve;

measuring a second fluid pressure at the implement-facing side of the fluid valve;

based on the first and second measured fluid pressures, determining the actual flow rate of hydraulic fluid through the fluid valve; and

adjusting the fluid valve such that the actual flow rate equals the desired flow rate.

16. The method of claim 15, wherein the step of receiving a desired fluid flow rate comprises providing an input device to a user, and receiving a user-defined fluid flow rate via said input device.

17. The method of claim 15, further comprising the steps of receiving an implement identifier associated with an agricultural implement, and adjusting desired fluid flow rate for an agricultural implement based on the received implement identifier.

18. A controller for an agricultural vehicle, the controller arranged to implement the steps as claimed in claim 15.