Central tyre inflation system and method

Patent metadata

Field	Value
Publication number	US-10946328-B2
Application number	US-201615745657-A
Country	US
Kind code	B2
Filing date	Jul 14, 2016
Priority date	Jul 17, 2015
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A central tire inflation system (CTIS) for a vehicle includes a reservoir for supplying air to the vehicle tires, a pressure sensor for monitoring air pressure in the reservoir, a compressor for supplying compressed air along a first flow path to the reservoir, a compressor timer for monitoring the run-time of the compressor, a dryer disposed on the first flow path for drying air supplied by the compressor, a purging system for routing air through the dryer along a second flow path to purge liquid from the dryer, and a controller for controlling the flow of air in the CTIS. The controller is configured: to activate the compressor in response to a request for a compressor operation, after which operation the air in the reservoir is at a post-operation pressure; when the compressor operation is complete, to determine a compressor activation period, and to determine if the compressor activation period is greater than or equal to a target period; and if the compressor activation period is less than the target period, to keep the compressor activated until pressure in the reservoir increases to a base target pressure greater than the post-operation pressure; and if the compressor activation period is greater than or equal to the target period, to keep the compressor activated until pressure in the reservoir increases to an elevated target pressure higher than the base target pressure and to activate the purging system to route air from the reservoir to purge the dryer of liquid.

First claim

The invention claimed is:

1. A central tire inflation system (CTIS) for a vehicle, the CTIS comprising a reservoir for supplying air to one or more vehicle tires, a pressure sensor for monitoring air pressure in the reservoir, a compressor for supplying compressed air along a first flow path to the reservoir, a compressor timer for monitoring a run-time of the compressor, a dryer disposed on the first flow path for drying air supplied by the compressor, a purge valve for routing air through the dryer along a second flow path to purge liquid from the dryer, and a controller for controlling the flow of air in the CTIS; wherein the controller is configured:
to activate the compressor to supply air along the first flow path to the reservoir in response to a request for a compressor operation, after which operation the air in the reservoir is at a post-operation pressure;
when the compressor operation is complete, to determine a compressor activation period in dependence on a measurement by the compressor timer, and to determine if the compressor activation period is greater than or equal to a target period; and
if the compressor activation period is less than the target period, to keep the compressor activated until pressure in the reservoir increases to a base target pressure greater than the post-operation pressure; and
if the compressor activation period is greater than or equal to the target period, to keep the compressor activated until pressure in the reservoir increases to an elevated target pressure higher than the base target pressure and to activate the purge valve to route air from the reservoir along the second flow path to purge the dryer of liquid.

2. The CTIS of claim 1 , wherein the controller comprises:
an electronic processor having a first electrical input for receiving an electrical signal indicative of the value of the compressor activation period, a second electrical input for receiving an electrical signal indicative of the pressure in the reservoir, a first electronic output for controlling the compressor and a second electronic output for controlling the purge valve; and
an electronic memory device electrically coupled to the electronic processor and having instructions stored therein;
wherein the processor is configured to access the memory device and execute the instructions stored therein.

3. The CTIS of claim 1 , wherein the compressor activation period is a time period for which the compressor has been active when the compressor operation is complete.

4. The CTIS of claim 1 , wherein the compressor activation period is the sum of a time period for which the compressor has been active when the compressor operation is complete, and an estimated time period for which the compressor would be active to refill the reservoir to the base target pressure.

5. The CTIS of claim 1 , wherein the base target pressure is between 7 bar(g) and 8 bar(g).

6. The CTIS of claim 1 , wherein the elevated target pressure is between 8 bar(g) and 9 bar(g).

7. The CTIS of claim 1 , wherein the controller is configured to activate the purge valve to route air along the second flow path until the pressure in the reservoir reaches a post-purge target pressure.

8. The CTIS of claim 7 , wherein the post-purge target pressure is less than the base target pressure.

9. The CTIS of claim 8 , wherein the post-purge target pressure is between 4 bar(g) and 6 bar(g).

10. The CTIS of claim 1 , wherein the controller is configured to reset the compressor timer after purging the dryer if the compressor activation period is greater than or equal to the target period.

11. The CTIS of claim 1 , wherein the purge valve is on the second flow path.

12. The CTIS of claim 1 , comprising a reservoir valve disposed on the first flow path between the reservoir and the dryer.

13. The CTIS of claim 12 , wherein the purge valve is on the second flow path and wherein the controller is configured to close the reservoir valve and open the purge valve after refilling the reservoir to the base target pressure, so as to vent pressure in the CTIS system through the dryer, if the compressor activation period is less than the target period.

14. The CTIS of claim 12 wherein the purge valve is on the second flow path and wherein the controller is configured to activate the purging system by opening the purge valve while the reservoir valve is open.

15. The CTIS of claim 1 , wherein the compressor operation is the inflation of one or more tires or the refilling of the reservoir.

16. The CTIS of claim 1 , wherein the target period is selected such that, in order to inflate four tires of the vehicle, the compressor must run for a time period that is greater than or equal to the target period.

17. The CTIS of claim 1 , wherein the target period and/or the base target pressure and/or the elevated target pressure can be modified to suit operating conditions of the CTIS.

18. A method of purging a dryer in a central tire inflation system (CTIS) of a vehicle, the CTIS comprising a reservoir containing compressed air for supply to one or more vehicle tires, a compressor for supplying compressed air to the reservoir, a compressor timer for monitoring a run-time of the compressor, a dryer for drying air supplied by the compressor, and a controller for controlling at least the operation of the compressor, and the method, when executed by the controller of the CTIS, causes the controller to perform method steps comprising;
activating the compressor such that air flows into the reservoir to effect a compressor operation, after which operation air in the reservoir is at a post-operation pressure;
after the compressor operation is complete, determining a compressor activation period in dependence on a measurement by the compressor timer; and
in the case that the compressor activation period is less than a target period, operating the compressor to refill the reservoir with air until pressure in the reservoir increases to a base target pressure higher than the post-operation pressure; and
in the case that the compressor activation period is greater than or equal to a target period, operating the compressor to refill the reservoir with air until pressure in the reservoir reaches an elevated target pressure higher than the base target pressure, and routing air from the reservoir through the dryer to purge the dryer of liquid such that the pressure in the reservoir decreases from the elevated target pressure to a pressure lower than the elevated target pressure.

19. The method of claim 18 , wherein the compressor activation period is a time period for which the compressor has been active when the compressor operation is complete.

20. The method of claim 18 , wherein the compressor activation period is the sum of a time period for which the compressor has been active when the compressor operation is complete, and an estimated time period for which the compressor would be active to refill the reservoir to the base target pressure.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Dunning Emma-Claire
• King Paul

Classifications

• B60C23/00372 Primary

  characterised by fluid diagrams · CPC title

• B60C23/00354

  Details of valves · CPC title

• B01D53/0454 Primary

  Controlling adsorption (controlling temperature swing adsorption B01D53/0462, controlling pressure swing adsorption B01D53/047) · CPC title

• B60C23/001 Primary

  Devices for manually or automatically controlling or distributing tyre pressure whilst the vehicle is moving · CPC title

• B01D53/261

  by adsorption · CPC title