Monitoring the ventilation of a crankcase of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-12264634-B2
Application number	US-202218716218-A
Country	US
Kind code	B2
Filing date	Nov 28, 2022
Priority date	Dec 7, 2021
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

Various embodiments include a method for monitoring the ventilation of a crankcase of an internal combustion engine with combustion chambers and a nitrogen oxide sensor arranged in an exhaust system, the sensor configured to detect an amount of nitrogen oxide in exhaust gas of the internal combustion engine. An example method includes: determining a predefined operating mode of the internal combustion engine defined by substantially no combustion of an air/fuel mixture taking place inside the combustion chambers; determining an amount of nitrogen oxide in the exhaust gas during the predefined operating mode of the internal combustion engine using the exhaust gas sensor; and identifying functional ventilation of the crankcase if the detected nitrogen oxide level exceeds a predefined nitrogen oxide threshold or identifying a malfunction if the detected nitrogen oxide level is below the predefined nitrogen oxide threshold.

First claim

What is claimed is:

1. A method for monitoring the ventilation of a crankcase of an internal combustion engine with combustion chambers and a nitrogen oxide sensor arranged in an exhaust system, the sensor configured to detect an amount of nitrogen oxide in exhaust gas of the internal combustion engine, the method comprising:
determining a predefined operating mode of the internal combustion engine defined by substantially no combustion of an air/fuel mixture taking place inside the combustion chambers;
determining an amount of nitrogen oxide in the exhaust gas during the predefined operating mode of the internal combustion engine using the exhaust gas sensor; and
identifying functional ventilation of the crankcase if the detected nitrogen oxide level exceeds a predefined nitrogen oxide threshold or identifying a malfunction if the detected nitrogen oxide level is below the predefined nitrogen oxide threshold.

2. The method as claimed in claim 1 , wherein determining the nitrogen oxide level takes place after a predefined duration of time after the predefined operating mode of the internal combustion engine has been detected elapses.

3. The method as claimed in claim 2 , wherein the predefined duration is approximately 5 seconds.

4. The method as claimed in claim 1 , wherein the predefined operating mode of the internal combustion engine comprises an overrun cut-off phase of the internal combustion engine.

5. The method as claimed in claim 1 , further comprising
issuing a warning to the operator of the internal combustion engine if it is determined that the ventilation of the crankcase is malfunctioning.

6. The method as claimed in claim 1 , wherein the predefined nitrogen oxide threshold is between approximately 5 ppm and approximately 20 ppm.

7. An internal combustion engine comprising:
a combustion chamber with a reciprocating piston inside a cylinder;
a crankcase in which the piston is arranged at least in part and fluidically connected to the combustion chamber by a gap between the piston and the cylinder;
an exhaust system fluidically connected to the combustion chamber;
a nitrogen oxide sensor to arranged in the exhaust system and configured to detect an amount of nitrogen oxide in exhaust gas of the internal combustion engine; and
a control unit configured to
determine a predefined operating mode of the internal combustion engine defined by substantially no combustion of an air/fuel mixture taking place inside the combustion chambers;
determine an amount of nitrogen oxide in the exhaust gas during the predefined operating mode of the internal combustion engine using the exhaust gas sensor; and
identify functional ventilation of the crankcase if the detected nitrogen oxide level exceeds a predefined nitrogen oxide threshold or identifying a malfunction if the detected nitrogen oxide level is below the predefined nitrogen oxide threshold.

8. The internal combustion engine as claimed in claim 7 , further comprising
a catalytic converter arranged downstream of the nitrogen oxide sensor.

9. The internal combustion engine as claimed in claim 7 , further comprising:
an intake pipe fluidically connected to the combustion chamber and configured to supply air for combustion of an air/fuel mixture to the combustion chamber; and
a vent line fluidically connecting the crankcase to the intake pipe.

Assignees

• Vitesco Tech Gmbh

Inventors

• Rodatz Paul
• Haft Gerhard
• Nienhoff Michael
• Fink Fabian

Classifications

• F02D41/22

  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 title

• F01M2013/0077

  Engine parameters used for crankcase breather systems · CPC title

• F01M2013/0005

  with systems regulating the pressure in the carter · CPC title

• F01M13/00 Primary

  Crankcase ventilating or breathing · CPC title

• F02D2250/08

  Engine blow-by from crankcase chamber · CPC title