Method and system for prioritizing vehicle vacuum

Patent metadata

Field	Value
Publication number	US-9488168-B2
Application number	US-201414492649-A
Country	US
Kind code	B2
Filing date	Sep 22, 2014
Priority date	Mar 17, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A vacuum prioritization system for a vehicle is disclosed. In one example, use and availability of vacuum provided via vacuum sources is allocated to higher priority vacuum operated actuators when a pressure in the vacuum system exceeds a threshold pressure. The lower priority vacuum operated actuators have access to vacuum supplied via the vacuum sources when pressure in the vacuum system is less than a threshold pressure. The approach may allow higher priority actuators to operate for an extended amount of time.

First claim

The invention claimed is:

1. A vacuum prioritization method for a vehicle, comprising:
providing vacuum via at least one vehicle vacuum source solely to a first actuator group when a pressure of a first vacuum reservoir is greater than a first threshold pressure;
providing vacuum via the at least one vehicle vacuum source to the first actuator group and a second actuator group when the pressure of the first vacuum reservoir is less than the first threshold pressure; and
supplying vacuum to the second actuator group via a second vacuum reservoir when the pressure in the first vacuum reservoir is greater than the first threshold pressure.

2. The vacuum prioritization method of claim 1 , where the at least one vehicle vacuum source includes an intake manifold of an engine and a vacuum pump or an ejector, where the first actuator group and second actuator group are comprised of vacuum operated actuators, and where the first vacuum reservoir is a brake booster reservoir.

3. The vacuum prioritization method of claim 2 , where the vacuum pump is selectively activated in response to the pressure of the first vacuum reservoir.

4. The vacuum prioritization method of claim 1 , where air flow between the first vacuum reservoir and the second vacuum reservoir is limited via an orifice or a valve that is controlled in response to the pressure of the first vacuum reservoir.

5. The vacuum prioritization method of claim 1 , further comprising holding the second actuator group in an operating state when the pressure in the first vacuum reservoir is greater than the first threshold pressure and when a pressure in the second vacuum reservoir is greater than a second threshold pressure.

6. The vacuum prioritization method of claim 1 , further comprising increasing an amount of vacuum supplied to the first vacuum reservoir via adjusting operation of an engine when the pressure of the first vacuum reservoir is greater than the first threshold pressure and when a torque demand of the engine is less than a threshold torque demand.

7. A system for providing vacuum for a vehicle, comprising:
a brake-booster vacuum reservoir;
a secondary vacuum reservoir;
a first vacuum source in communication with the brake-booster and secondary vacuum reservoirs;
a second vacuum source in communication with the brake-booster and secondary vacuum reservoirs; and
a device to provide priority to receive vacuum at the brake-booster vacuum reservoir over the secondary vacuum reservoir via the first vacuum source and the second vacuum source.

8. The system of claim 7 , where the device is an orifice positioned in a conduit at a location between the brake-booster vacuum reservoir and the secondary vacuum reservoir.

9. The system of claim 7 , where the device is a controller including instructions for prioritizing vacuum supplied via the first vacuum source and the second vacuum source to the brake-booster vacuum reservoir and the secondary vacuum reservoir.

10. The system of claim 9 , where the first vacuum source is an intake manifold of an engine, and further comprising additional instructions for decreasing a pressure of the intake manifold when a pressure of the brake-booster vacuum reservoir exceeds a first pressure while an engine torque demand is less than a first torque demand.

11. The system of claim 7 , where the device is a pneumatically controlled valve.

12. The system of claim 7 , where the second vacuum source is a vacuum pump or an ejector.

13. The system of claim 7 , where a plurality of vacuum consumers is in communication with the secondary vacuum reservoir and where the device to provide priority to receive vacuum at the brake-booster vacuum reservoir over the secondary vacuum reservoir limits vacuum to the plurality of vacuum consumers.

14. A system for providing vacuum for a vehicle, comprising:
an engine intake system;
a first vacuum reservoir;
a turbocharger with a compressor coupled in the engine intake system;
a second vacuum reservoir pneumatically coupled to the engine intake system;
a first group of vacuum operated actuators in pneumatic communication with the first vacuum reservoir;
a second group of vacuum operated actuators in pneumatic communication with the second vacuum reservoir;
a first vacuum source comprising an engine intake manifold in pneumatic communication with the first vacuum reservoir and the second vacuum reservoir;
a second vacuum source in pneumatic communication with the first vacuum reservoir and the second vacuum reservoir; and
a controller configured to limit air flow from the second vacuum reservoir to the first vacuum reservoir, the first vacuum source, and the second vacuum source when a pressure of the first vacuum reservoir is greater than a first threshold pressure.

15. The system of claim 14 , where the controller is a pneumatically actuated valve.

16. The system of claim 14 , where the controller includes a processor and input and output ports, the system further comprising an electrically operated valve in electrical communication with the controller.

17. The system of claim 16 , where the controller includes instructions to close the electrically operated valve when a pressure of the first vacuum reservoir is greater than a first pressure.

18. The system of claim 14 , where the first group of vacuum operated actuators includes a brake booster.

19. The system of claim 14 , where the second group of vacuum operated actuators includes a compressor bypass valve and a waste gate actuator.

Assignees

• Ford Global Tech Llc

Inventors

• Pursifull Ross Dykstra

Classifications

• F02B47/00

  Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines · CPC title

• F02D2009/0266

  in which movement is transmitted through a vacuum motor · CPC title

• F04B49/03 Primary

  by means of valves · CPC title

• F02D2009/024

  Increasing intake vacuum · CPC title