Device for maintaining a hydraulic supply of a utility vehicle

Patent metadata

Field	Value
Publication number	US-12083974-B2
Application number	US-202318192911-A
Country	US
Kind code	B2
Filing date	Mar 30, 2023
Priority date	Mar 31, 2022
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

A device for maintaining a hydraulic supply of a utility vehicle includes a hydraulic pump, which is adjustable in terms of its delivery volume via a pressure control inlet, for feeding hydraulic fluid to a hydraulic circuit, a pressure accumulator that can be charged from the hydraulic circuit via a check valve, a pressure connection between the hydraulic circuit and the pressure control inlet of the hydraulic pump being producible via a sensor line by means of a charging valve, and a supply connection between the pressure accumulator and the hydraulic circuit being producible by means of a discharging valve, by virtue of the check valve being bypassed.

First claim

What is claimed is:

1. A device for maintaining a hydraulic supply of a utility vehicle, comprising:
a hydraulic pump, which is adjustable in terms of its delivery volume via a pressure control inlet, for feeding hydraulic fluid to a hydraulic circuit;
a pressure accumulator that can be charged from the hydraulic circuit via a check valve;
a pressure connection between the hydraulic circuit and the pressure control inlet of the hydraulic pump being producible via a charging valve; and
a supply connection between the pressure accumulator and the hydraulic circuit being producible by a discharging valve, by virtue of the check valve being bypassed;
wherein hydraulic fluid can be fed to the hydraulic circuit via a further check valve, from an additional hydraulic supply that is connectable by way of a releasable hydraulic coupling, a switching valve simultaneously producing a connection between a return line of the hydraulic circuit and a reservoir of the additional hydraulic supply, in such a way that the hydraulic fluid quantity contained in the hydraulic circuit of the utility vehicle remains substantially constant.

2. The device of claim 1 , wherein the supply connection is produced via a pressure-limiting valve that is arranged between the pressure accumulator and hydraulic circuit.

3. The device of claim 2 , wherein the pressure-limiting valve is configured as a pressure control valve for providing a specified working pressure in the hydraulic circuit.

4. The device of claim 1 , wherein the discharging valve is configured to assume an opened position in response to a specified minimum delivery pressure of the hydraulic pump being undershot as sensed by a pressure sensor.

5. The device of claim 1 , wherein the charging valve assumes an opened position if a minimum accumulator pressure that is to be maintained for the accumulator pressure is undershot in the pressure accumulator.

6. The device of claim 1 , wherein an actuating device, which is controlled on the basis of a detection of pressure, is provided for opening at least one of the discharging valve and the charging valve.

7. The device of claim 1 , wherein the pressure accumulator is a piston-type accumulator that can be preloaded by way of a gaseous operating medium.

8. The device of claim 7 , further comprising:
a controller configured to infer a present energy storage capacity of the piston-type accumulator in accordance with a prefill pressure detected by a sensor in a specified accumulator state.

9. The device of claim 7 , further comprising:
a controller including a processor and a memory, wherein the memory stores nominal specifications of the piston-type accumulator, and wherein the controller is configured to infer a present energy storage capacity of the piston-type accumulator based on a comparison of a signal detected by at least one sensor with a corresponding one of the nominal specifications of the piston-type accumulator stored in the memory.

10. The device of claim 7 , further comprising:
a controller configured to infer a present energy storage capacity of the piston-type accumulator by comparing a prefill pressure detected by a first sensor with a piston position which is detected by a second sensor and which corresponds to the respective prefill pressure.

11. A device for maintaining a hydraulic supply of a utility vehicle, comprising:
a hydraulic pump for feeding hydraulic fluid to a hydraulic circuit, the hydraulic pump having a pressure control inlet, the hydraulic pump configured to be adjustable in terms of its delivery volume;
a pressure accumulator configured to be charged from the hydraulic circuit by way of a check valve;
a pressure connection between the hydraulic circuit and the pressure control inlet of the hydraulic pump, the pressure connection including a charging valve;
a supply connection between the pressure accumulator and the hydraulic circuit, the supply connection including a discharging valve, the supply connection configured to bypass the check valve; and
a controller including a processor and a memory, wherein the memory stores nominal specifications of the pressure accumulator, and wherein the controller is configured to infer a present energy storage capacity of the pressure accumulator by comparing a signal detected by at least one sensor with a corresponding one of the nominal specifications of the pressure accumulator stored in the memory;
wherein the discharging valve is configured to open in response to a detected pressure signal.

12. The device of claim 11 , further comprising:
an actuating device configured to open the discharging valve in response to the detected pressure signal.

13. The device of claim 11 , wherein the discharging valve is configured to open in response to the detected pressure signal when the detected pressure sensed by a pressure sensor is below a specified minimum delivery pressure of the hydraulic pump.

14. The device of claim 11 , wherein the at least one sensor detects
a prefill pressure of the pressure accumulator in a specified accumulator state.

15. The device of claim 11 , wherein the at least one sensor includes a first sensor detecting a prefill pressure of the pressure accumulator and a second sensor detecting a piston position, wherein the corresponding one of the nominal specifications includes a nominal piston position stipulated for the prefill pressure.

16. A device for maintaining a hydraulic supply of a utility vehicle, comprising:
a hydraulic pump for feeding hydraulic fluid to a hydraulic circuit, the hydraulic pump having a pressure control inlet, the hydraulic pump configured to be adjustable in terms of its delivery volume;
a pressure accumulator configured to be charged from the hydraulic circuit by way of a check valve;
a pressure connection between the hydraulic circuit and the pressure control inlet of the hydraulic pump, the pressure connection including a charging valve;
a supply connection between the pressure accumulator and the hydraulic circuit, the supply connection including a discharging valve, the supply connection configured to bypass the check valve; and
a controller including a processor and a memory, wherein the memory stores nominal specifications of the pressure accumulator, and wherein the controller is configured to infer a present energy storage capacity of the pressure accumulator by comparing a signal detected by at least one sensor with a corresponding one of the nominal specifications of the pressure accumulator stored in the memory.

17. The device of claim 16 , wherein the signal detected by at least one sensor includes a prefill pressure and the corresponding one of the nominal specifications includes a nominal prefill pressure.

18. The device of claim 16 , wherein the pressure accumulator is a piston-type accumulator, and wherein the signal detected by the at least one sensor includes a piston position and the corresponding one of the nominal specifications includes a nominal piston position.

19. The device of claim 18 , wherein the prefill pressure is detected by a first sensor, and wherein the at least one sensor further includes a second sensor configured to detect a piston position.

Assignees

• Deere & Co

Inventors

• Letscher Jens

Classifications

• F15B2201/205

  using gas · CPC title

• F15B13/027

  Check valves · CPC title

• F15B1/04

  Accumulators · CPC title

• B62D5/30

  Safety devices, e.g. alternate emergency power supply or transmission means to ensure steering upon failure of the primary steering means · CPC title

• B60T13/148

  Arrangements for pressure supply · CPC title