Method and system for providing vacuum via excess boost

Patent metadata

Field	Value
Publication number	US-9010115-B2
Application number	US-201113050683-A
Country	US
Kind code	B2
Filing date	Mar 17, 2011
Priority date	Mar 17, 2011
Publication date	Apr 21, 2015
Grant date	Apr 21, 2015

Abstract

A vacuum source including an ejector is disclosed. In one example, vacuum is supplied via the ejector when a turbocharger has excess boost capacity. The approach can prioritize how excess boost may be used to provide vacuum.

First claim

The invention claimed is:

1. A method for providing vacuum, comprising:
supplying air from a compressor to engine cylinders, the compressor having an air output capacity;
directing air flow from the compressor to an ejector supplying vacuum to a vacuum reservoir when the compressor has capacity to supply more air than a desired cylinder air amount, otherwise inhibiting air flow from the compressor to the ejector; and
reducing an amount of air flowing through the ejector in response to a torque demand exceeding a threshold torque demand.

2. The method of claim 1 , where the air output capacity of the compressor varies with engine operating conditions, and where directing air from the compressor to the ejector occurs when a pressure of a vacuum reservoir is more than a threshold pressure.

3. The method of claim 1 , where air flow from the compressor to the ejector is routed to an air intake system of an engine at a first or second location, the first location an intake manifold, the second location an inlet of the compressor.

4. The method of claim 3 , where air flow from the compressor to the ejector entering the intake manifold is adjusted based on a desired engine torque and a throttle position.

5. The method of claim 3 , where air flow from the ejector selectively exits into the intake manifold or the inlet of the compressor via check valves.

6. The method of claim 3 , where a throttle position is adjusted in response to air flow from the ejector to the intake manifold, and further comprising controlling compressor surge via directing air flow from the compressor to the ejector when a ratio of a pressure ratio across the compressor to a compressor flow rate is greater than a threshold.

7. The method of claim 1 , where air flow from the compressor to the ejector is adjusted in response to a vacuum consumption rate within a vacuum system.

8. The method of claim 1 , where inhibiting air flow from the compressor to the ejector occurs during a throttle tip-in.

9. A method for providing vacuum, comprising:
supplying air from a compressor to engine cylinders, the compressor having an air output capacity;
directing air flow from the compressor to an ejector supplying vacuum to a vacuum reservoir when the compressor has capacity to supply more air than a desired cylinder air amount, otherwise inhibiting air flow from the compressor to the ejector;
reducing the compressor's air output capacity when the compressor has capacity to supply an air amount greater than the desired cylinder air amount and a desired ejector flow rate, otherwise not reducing the compressor's air output capacity; and
reducing air flow from the compressor to the ejector in response to an increasing torque request and increasing air flow from the compressor to the engine.

10. The method of claim 9 , where the compressor's air output capacity is reduced via opening a waste gate or adjusting a vane of a turbine.

11. The method of claim 9 , where air flow from the compressor to the ejector is routed to an air intake system of an engine at one of a first or second location, the first location an intake manifold, the second location an inlet of the compressor.

12. The method of claim 9 , further comprising increasing flow to the ejector to reduce throttle inlet pressure.

13. The method of claim 9 , further comprising ceasing air flow from the compressor to the ejector supplying vacuum to the vacuum reservoir when a desired engine air flow rate is less than a threshold air flow rate.

14. The method of claim 9 , further comprising ceasing air flow from the compressor to the ejector supplying vacuum to the vacuum reservoir to increase speed of the compressor.

15. The method of claim 9 , where a throttle inlet pressure is adjusted in response to directing air flow from the compressor to the ejector supplying vacuum to the vacuum reservoir.

16. A vacuum system, comprising:
an engine with an intake manifold;
a turbocharger coupled to the engine and supplying air to the intake manifold;
a vacuum reservoir;
an ejector in communication with the vacuum reservoir and the turbocharger; and
a controller, the controller including instructions stored in non-transitory memory for supplying air from a compressor to engine cylinders, the compressor having an output capacity; directing air flow from the compressor to an ejector supplying vacuum to a vacuum reservoir when the compressor has capacity to supply more air than a desired cylinder air amount, otherwise inhibiting air flow from the compressor to the ejector; reducing the compressor's air output capacity when the compressor has capacity to supply an air amount greater than the desired cylinder air amount and a desired ejector flow rate, otherwise not reducing the compressor's air output capacity; and adjusting a position of a waste gate to adjust the compressor's air output capacity, where the controller includes further instructions stored in non-transitory memory for adjusting a motive flow rate of the ejector to provide a desired rate of vacuum.

17. The system of claim 16 , where the controller includes further instructions stored in non-transitory memory for limiting a rate of vacuum consumption via vacuum consumers in response to a pressure of the vacuum reservoir.

Assignees

• Pursifull Ross Dykstra
• Ulrey Joseph Norman
• Ford Global Tech Llc

Inventors

• Pursifull Ross Dykstra
• Ulrey Joseph Norman

Classifications

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02M35/10236

  Overpressure or vacuum relief means; Burst protection · CPC title

• F02B37/164

  the bypassed air being used in an auxiliary apparatus, e.g. in an air turbine · CPC title

• F01N5/04

  the devices using kinetic energy · CPC title

• F02D2250/41

  Control to generate negative pressure in the intake manifold, e.g. for fuel vapor purging or brake booster · CPC title