Multiple tap aspirator

Patent metadata

Field	Value
Publication number	US-9328702-B2
Application number	US-201314062323-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 24, 2013
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

Systems and methods are provided for engine systems including a vacuum-powered multiple tap aspirator coupled between atmospheric, an engine crankcase, or another source and a vacuum source such as a compressor inlet or engine intake manifold. The multiple tap aspirator includes a suction tap arranged in a throat of the aspirator, a suction tap arranged in a diverging cone of the aspirator, and a suction tap arranged in a straight exit tube downstream of the diverging cone of the aspirator. The aspirator provides vacuum generation and suction flow over a range of vacuum levels at the suction taps, and suction flow only passes through a single check valve before entering the aspirator.

First claim

The invention claimed is:

1. An engine system, comprising:
an aspirator with a suction tap in a throat of the aspirator, a suction tap in a diverging cone of the aspirator, and a suction tap in a straight tube downstream of the diverging cone, a motive inlet of the aspirator coupled with atmosphere and a mixed flow outlet of the aspirator coupled with a vacuum source, wherein the suction tap in the throat and the suction tap in the straight tube are coupled with a vacuum reservoir via respective parallel suction passages merging into a single passage downstream of the vacuum reservoir, wherein the suction tap in the diverging cone is coupled with a fuel vapor canister, and wherein a check valve is arranged in each passage.

2. The engine system of claim 1 , wherein the mixed flow outlet of the aspirator is coupled with an intake passage of the engine upstream of a boost device and downstream of an air induction system throttle.

3. The engine system of claim 1 , wherein the mixed flow outlet of the aspirator is coupled with an intake manifold of the engine.

4. The engine system of claim 3 , wherein suction flow into each tap of the aspirator passes through only one check valve before entering the tap.

5. A method for an engine, comprising:
directing atmospheric air through an aspirator comprising a suction tap in a throat of the aspirator, a suction tap in a diverging cone of the aspirator, and a suction tap in a straight tube downstream of the diverging cone into an intake manifold of the engine based on pressure at a mixed flow outlet of the aspirator, the suction tap in the throat and the suction tap in the straight tube coupled with a vacuum reservoir via respective parallel suction passages merging into a single passage downstream of the vacuum reservoir, and the suction tap in the diverging cone coupled with a fuel vapor canister;
determining a flow level entering each suction tap of the aspirator;
determining a composition and amount of fluid exiting the mixed flow outlet of the aspirator based on the flow level entering each suction tube of the aspirator and an inference of fuel vapor concentration of fluid entering the suction tap in the diverging cone; and
compensating engine air-fuel ratio based on the composition and amount of fluid exiting the mixed flow outlet of the aspirator.

6. The method of claim 5 , wherein directing atmospheric air through the aspirator comprises increasing opening of an aspirator shut off valve arranged in series with a motive inlet of the aspirator, the method further comprising determining a desired flow level through the aspirator and adjusting the aspirator shut off valve based on the desired flow level through the aspirator.

7. The method of claim 6 , further comprising adjusting the aspirator shut off valve based on a pressure in the fuel vapor canister.

8. The method of claim 6 , further comprising adjusting the aspirator shut off valve based on pressure in the intake manifold.

9. The method of claim 6 , further comprising closing the aspirator shut off valve when intake manifold pressure exceeds atmospheric pressure.

10. The method of claim 5 , wherein compensating engine air-fuel ratio based on the composition and amount of fluid exiting the mixed flow outlet of the aspirator comprises adjusting fuel injection based on a desired engine air-fuel ratio.

11. A method for an engine, comprising:
directing crankcase gases through an aspirator comprising a suction tap in a throat of the aspirator, a suction tap in a diverging cone of the aspirator, and a suction tap in a straight tube downstream of the diverging cone into an engine intake system when crankcase pressure exceeds a threshold,
wherein the crankcase gases are directed into an intake passage of the engine upstream of a boost device and downstream of an air induction system throttle, the method further comprising adjusting the air induction system throttle based on a desired level of flow through the aspirator.

12. The method of claim 11 , wherein the crankcase gases are directed into an intake manifold of the engine.

13. The method of claim 12 , wherein directing crankcase gases through the aspirator comprises increasing opening of an aspirator shut off valve arranged in series with a motive inlet of the aspirator, the method further comprising closing the aspirator shut off valve when intake manifold pressure exceeds crankcase pressure.

14. The engine system of claim 1 , wherein the suction passage coupled to the suction tap in the throat is smaller than a suction passage coupled to the suction tap in the diverging cone, and wherein the suction passage coupled to the suction tap in the diverging cone is smaller than the suction passage coupled to the suction tap in the straight tube.

15. The method of claim 5 , wherein the determination of the flow level entering each suction tap of the aspirator is based on barometric pressure, intake manifold pressure, aspirator shut off valve state, fuel vapor canister pressure, and vacuum reservoir pressure.

16. The method of claim 5 , wherein directing atmospheric air through the aspirator comprises increasing opening of an aspirator shut off valve arranged in series with a motive inlet of the aspirator, the method further comprising determining a desired flow level through the aspirator based on engine operating conditions and adjusting the aspirator shut off valve based on the desired flow level through the aspirator.

17. The method of claim 6 , wherein the determination of the desired flow level through the aspirator is based on barometric pressure, intake manifold pressure, a level of stored vacuum in the vacuum reservoir, and a pressure in the fuel vapor canister.

18. The method of claim 11 , wherein adjusting the air induction system throttle based on the desired level of flow through the aspirator comprises increasing closing of the air induction system throttle to increase flow through the aspirator, and increasing opening of the air induction system throttle to decrease flow through the aspirator.

19. The method of claim 13 , further comprising adjusting the air induction system throttle to regulate flow through the aspirator during a failure of the aspirator shut off valve.

Assignees

• Ford Global Tech Llc

Inventors

• Pursifull Ross Dykstra
• Vanderwege Brad Alan

Classifications

• F02M35/10

  Air intakes; Induction systems · CPC title

• F02M35/1294

  Amplifying, modulating, tuning or transmitting sound, e.g. directing sound to the passenger cabin; Sound modulation · CPC title

• F02M35/10275

  Means to avoid a change in direction of incoming fluid, e.g. all intake ducts diverging from plenum chamber at acute angles; Check valves; Flame arrestors for backfire prevention · CPC title

• B60K25/04 Primary

  from static or dynamic pressure or vacuum, developed by the engine · CPC title

• F04F5/52

  of evacuating pumps · CPC title