Method for compensating valve drift in an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10690076-B2
Application number	US-201615740921-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Jul 27, 2015
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A method for compensating valve drift in an internal combustion engine having a variable valve train; in the method, an actual value of the current operating state of the internal combustion engine is determined in an air expenditure map and compared to a desired value of the air expenditure map, whereupon the air expenditure map is corrected.

First claim

The invention claimed is:

1. A method for compensating valve drift in an internal combustion engine having a variable valve drive, the method comprising the steps of: determining an actual value of an instantaneous operating state of the internal combustion engine in a volumetric efficiency characteristic diagram, which volumetric efficiency characteristic diagram provides an air consumption in dependence on a closing point in time of an inlet valve, using a mass flow sensor; comparing the actual valve with a setpoint value of the volumetric efficiency characteristic diagram to determine a difference; and compensating the valve drift by subsequently correcting the volumetric efficiency characteristic diagram based on the difference.

2. The method according to claim 1 , wherein the step of correcting the volumetric efficiency characteristic diagram includes shifting the volumetric efficiency characteristic diagram.

3. The method according to claim 1 , wherein the step of correcting the volumetric efficiency characteristic diagram includes adding a correction factor.

4. The method according to claim 1 , including measuring air/gas mixture mass flow in an intake path using the mass flow sensor.

5. The method according to claim 1 , including carrying out measurement by the mass flow sensor in an intake path adjacent to a gas feed into the intake path.

6. The method according to claim 1 , including carrying out measurement by the mass flow sensor upstream of a compressor arranged in an intake path.

7. The method according to claim 1 , including applying the method in a stationary gas engine.

8. The method according to claim 1 , including carrying out the method during a stationary operating state of the internal combustion engine.

9. The method according to claim 8 , including carrying out the method during a stationary mode which lasts over a time period of longer than 30 seconds.

10. The method according to claim 1 , wherein during the step of correcting the volumetric efficiency characteristic diagram charge pressure and/or rotational speed of the internal combustion engine are changed.

Assignees

• Mtu Friedrichshafen Gmbh

Inventors

• Boyde Jan
• Fimml Wolfgang
• Schäfer Erika

Classifications

• F02D41/18 Primary

  by measuring intake air flow · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D13/0223

  Variable control of the intake valves only · CPC title

• F02D41/0027

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title

• F02D41/2451

  characterised by what is learned or calibrated · CPC title