CRANKCASE INTEGRITY BREACH DETECTION

• US 20140081548A1
• Filed: 09/14/2012
• Published: 03/20/2014
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Pursifull, Ross Dykstra, Rollinger, John Eric
• Granted Patent: US 9,127,578 B2
• Time in Patent Office: Days
• US Class Current: 701/101
• CPC Class Codes: F01M 11/10 Indicating devices; Other safety devices
• CPC Class Codes: F01M 13/00 Crankcase ventilating or breathing
• CPC Class Codes: F01M 2013/0083 Crankcase pressure
• CPC Class Codes: F02D 2250/08 Engine blow-by from crankcase chamber
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02M 25/06 adding lubricant vapours
• CPC Class Codes: F02M 35/10222 Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission
• CPC Class Codes: F02M 35/1038 for temperature or pressure
• CPC Class Codes: G01M 15/042 by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Systems and methods for monitoring crankcase ventilation system integrity are disclosed. In one example approach, a method comprises indicating a crankcase ventilation system degradation based on a lower vacuum than expected downstream of a PCV breather tube. For example, indicating a crankcase ventilation system degradation based on a lower vacuum than expected downstream of a PCV breather tube may include indicating a crankcase ventilation system degradation based on an absolute pressure sensor measurement relative to a gauge pressure sensor measurement.

Claims

1. A method for an engine, comprising:

indicating a crankcase ventilation system degradation based on a lower vacuum than expected downstream of a PCV breather tube.

2. The method of claim 1, wherein indicating a crankcase ventilation system degradation based on a lower vacuum than expected downstream of a PCV breather tube includes indicating a crankcase ventilation system degradation based on an absolute pressure sensor measurement relative to a gauge pressure sensor measurement.

3. The method of claim 2, wherein the absolute pressure sensor is a barometric pressure sensor and the gauge pressure sensor is a compressor inlet pressure sensor.

4. The method of claim 2, wherein the absolute pressure sensor is a barometric pressure sensor and the gauge pressure sensor is a pressure sensor disposed in a PCV breather tube.

5. The method of claim 2, wherein the absolute pressure sensor is a compressor inlet pressure sensor and the gauge pressure sensor is a barometric pressure sensor.

6. The method of claim 2, wherein the absolute pressure sensor is a pressure sensor disposed in a PCV breather tube and the gauge pressure sensor is a barometric pressure sensor.

7. The method of claim 2, wherein the absolute pressure sensor is a compressor inlet pressure sensor and the gauge pressure sensor is a pressure sensor disposed in a PCV breather tube.

8. The method of claim 2, wherein the absolute pressure sensor is a pressure sensor disposed in a PCV breather tube and the gauge pressure sensor is a compressor inlet pressure sensor.

9. The method of claim 2, wherein a crankcase ventilation system degradation is indicated when the absolute pressure sensor measurement is substantially equal to the gauge pressure sensor measurement.

10. The method of claim 2, wherein the absolute pressure sensor measurement and the gauge pressure sensor measurement are measured during a high intake air flow engine operating condition.

11. The method of claim 2, wherein indicating a crankcase ventilation system degradation includes indicating a breach in the crankcase ventilation system.

12. A method for an engine, comprising:

indicating a crankcase ventilation system degradation based on relative pressure sensor readings of only two of a barometric pressure sensor, compressor inlet pressure sensor, and a pressure sensor disposed in a PCV breather tube.

13. The method of claim 12, wherein a crankcase ventilation system degradation is indicated when sensor readings of only two of a barometric pressure sensor, compressor inlet pressure sensor, and a pressure sensor disposed in a PCV breather tube are substantially equal.

14. The method of claim 12, wherein a crankcase ventilation system degradation is not indicated when sensor readings of only two of a barometric pressure sensor, compressor inlet pressure sensor, and a pressure sensor disposed in a PCV breather tube are not substantially equal.

15. The method of claim 12, wherein the sensor readings of only two of a barometric pressure sensor, compressor inlet pressure sensor, and a pressure sensor disposed in a PCV breather tube are measured during a high intake air flow engine operating condition.

16. The method of claim 12, wherein indicating a crankcase ventilation system degradation includes indicating a breach in the crankcase ventilation system.

17. The method of claim 12, wherein the barometric pressure sensor is disposed in an intake of the engine upstream from a PCV breather tube coupling with the engine intake and the compressor inlet pressure sensor is disposed in the engine intake downstream of the PCV breather tube coupling with the engine intake.

18. A method for an engine with a positive crankcase ventilation system, comprising:

during a high air speed engine operating condition, indicating a crankcase ventilation system degradation based on a barometric pressure relative to a compressor inlet pressure.

19. The method of claim 18, wherein the barometric pressure is measured via a sensor disposed in an intake of the engine upstream from a PCV breather tube coupling with the engine intake and the compressor inlet pressure is measured via a sensor disposed in the engine intake downstream of the PCV breather tube coupling with the engine intake, and wherein a crankcase ventilation system degradation is indicated when the barometric pressure is substantially equal to the compressor inlet pressure.

20. The method of claim 18, wherein the barometric pressure is measured via a sensor disposed in an intake of the engine upstream from a PCV breather tube coupling with the engine intake and the compressor inlet pressure is measured via a sensor disposed in the engine intake at the PCV breather tube coupling with the engine intake, and wherein a crankcase ventilation system degradation is indicated when the barometric pressure is substantially equal to the compressor inlet pressure.