SYSTEM AND METHOD FOR ANALYZING CARBON BUILD UP IN AN ENGINE

• US 20140182548A1
• Filed: 03/15/2013
• Published: 07/03/2014
• Est. Priority Date: 06/22/2012
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Thompson, Bernie C., Pederson, Neal R.
• Granted Patent: US 9,279,406 B2
• Time in Patent Office: Days
• US Class Current: 123/406.19
• CPC Class Codes: F02P 17/02 Checking or adjusting ignition timing
• CPC Class Codes: F02P 5/04 automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions dependent on position of personal controls of engine F02P5/02
• CPC Class Codes: G01M 15/04 Testing internal-combustion engines
• CPC Class Codes: G01M 15/10 by monitoring exhaust gases or combustion flame
• CPC Class Codes: G01M 15/106 using pressure sensors
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: G07C 5/006 Indicating maintenance
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

An induction cleaning analyzing system includes a pressure sensor, an ignition event detector, and a control module. The pressure sensor measures airflow pressures of intake air and/or exhaust from cylinders in a common airflow pathway of a vehicle. The ignition event detector determines ignition events of the cylinders. The control module obtains pressure waveforms representative of the airflow pressures and divides the pressure waveforms into waveform segments. The control module associates different subsets of the waveform segments with different ones of the cylinders using the ignition events. The control module also identifies cyclic variations in the airflow pressures flowing in the common airflow pathway and caused by at least one of the cylinders by examining the waveform segments associated with the at least one of the cylinders.

Claims

1. A method of identifying cyclic variations in combustion efficiency in cylinders of an internal combustion engine with aid of instrumentation, the engine including an air induction system, the cylinders, means for generating an ignition event for each of the cylinders, and an exhaust system, the instrumentation including one or more microprocessors programmed with one or more software routines, memory, and means for measuring cylinder pressure pulses;

the method including;

running the engine through a number of combustion cycles;

measuring the pressure pulses with the means for measuring cylinder pressure pulses;

generating a waveform from the measured cylinder pressure pulses;

dividing the waveform of the measured cylinder pressure pulses into waveform cycles and cycle segments, wherein each waveform cycle represents a complete combustion cycle of the engine, wherein each cycle segment represents a combustion cycle of a separate cylinder of the engine, and wherein a total number of the cycle segments equals a total number of the cylinders;

marking each of the waveform segments from a cycle of the engine with a separate and distinct identifier, and repeating this identifier sequence for a number of successive cycles; and

comparing each individual waveform segment during a particular cycle with the waveform segment having the same identifier for a number of successive cycles to identify cycle to cycle variations for each waveform segment.

2. The method as set forth in claim 1, wherein the instrumentation further includes means for detecting at least some of the ignition events, and wherein dividing the waveform into waveform cycles and waveform segments includes utilizing the at least some of the ignition events that are detected.

3. The method as set forth in claim 2, wherein the means for detecting at least some of the ignition signals includes an antenna, and further including placing the antenna relative to the engine so that the antenna can detect at least some of the ignition events, and wherein the one or more software routines includes a routine to determine if the antenna is properly positioned relative to the engine such that the antenna is detecting at least some of the ignition signals, and further comprising determining if the antenna is properly positioned before proceeding to identify cyclic pressure variations in the combustion efficiency.

4. The method as set forth in claim 3, wherein, when the antenna does not pick up all of the ignition events from the engine, the one or more software routines includes a routine to identify and install waveform divisions on the pressure waveform that are not based on an ignition event picked up by the antenna, and

wherein dividing the waveform into divisions includes utilizing the ignition events that are picked up by the antenna to install division marks on the waveform and the routine to identify and install divisions in those locations along the waveform where a division is missing because an ignition event was not detected by the antenna.

5. The method as set forth in claim 2, wherein the instrumentation for detecting at least some of the ignition events includes a direct connection to the means for generating an ignition event for one of the cylinders.

6. The method as set forth in claim 1, wherein the one or more software routines includes a routine to determine if the means for measuring the cylinder pressure pulses is properly positioned and properly functioning so that the means for measuring detects all the pressure pulses from each of the plurality of cylinders, and further comprising utilizing the routine to determine if the means for measuring the cylinder pressure pulses is detecting all the pressure pulses.

7. The method as set forth in claim 1, wherein the instrumentation includes means for acquiring vehicle identification number (VIN) data associated with the engine being tested, wherein the one or more software routines includes a routine for analyzing the VIN data to determine a year, make, and model of the engine being tested, and further comprising acquiring the VIN data for the engine being tested and determining the year, make, and model of the engine.

8. The method as set forth in claim 7, wherein the VIN data is in the form of a barcode, the means for acquiring VIN data is a bar code scanner, and further comprising scanning the VIN barcode associated with the engine.

9. The method as set forth in claim 7, wherein the memory includes a data base of engines for which a correction factor is to be used with at least some of the one or more software routines, and further comprising checking the data base to determine if a correction needs to be applied and, if so, applying the correction factor to the at least some of the one or more software routines.

10. The method as set forth in claim 1, wherein the one or more software routines includes one or more routines for converting cycle-to-cycle variations associated with each waveform segment into a number representing an average turbulence in the air induction system of the engine which number also represents associated carbon buildup, and further comprising converting the cycle-to-cycle variations into a number representing the average waveform turbulence in the air induction system of the engine.

11. The method as set forth in claim 10, wherein the instrumentation includes a carbon buildup scale, wherein the one or more software routines includes a routine for converting the average waveform turbulence to a scale, and further comprising using a number representative of the average waveform turbulence and the routine for converting to scale the carbon buildup in the air induction system of the engine on the carbon build-up scale.

12. The method as set forth in claim 11, wherein the instrumentation includes a screen on which the carbon build-up scale is displayed, and further comprising displaying a scaled carbon buildup on the carbon build-up scale.

13. The method as set forth in claim 12, wherein displaying the scaled carbon buildup on the carbon buildup scale also includes displaying alert indicators selected from a group including one that advises that the air induction system should be cleaned and another that advises that the air induction system does not have to be cleaned.

14. The method as set forth in claim 10, wherein the one or more software routines includes a plurality of routines for converting cycle-to-cycle pressure variations associated with each waveform division into a like plurality of numbers each representing an average waveform turbulence in the air induction system of the engine, and further comprising converting the cycle-to-cycle variations into a plurality of numbers each representing an average waveform turbulence in the air induction system of such engine, and further including selecting a greatest one of the plurality of numbers as most accurately representing the average waveform turbulence in the air induction system of such engine and the carbon build up in the air induction system.

15. The method as set forth in claim 1, further including analyzing the individual waveform divisions for pressure variations that indicate an engine misfire.

16. The method as set forth in claim 15, further including displaying a visual indicator that the engine being tested has the engine misfire.

17. The method as set forth in claim 1, further comprising inserting the means for measuring the cylinder pressure pulses into the exhaust system, wherein the waveform is an exhaust pressure waveform.

18. The method as set forth in claim 17, wherein the means for measuring the pressure pulses is a venturi, and further comprising inserting the venturi into the exhaust system and measuring the cylinder pressure pulses from the venturi.

19. The method as set forth in claim 1, further comprising inserting the means for measuring the cylinder pressure pulses into the air induction system, whereby the waveform is an intake pressure waveform.

20. The method as set forth in claim 1, further comprising:

determining the carbon buildup in the air induction system of the engine from the cycle to cycle pressure variations;

chemically cleaning the air induction system; and

repeating the steps of measuring the pressure pulses, generating a waveform from the measured pressure pulses, dividing the waveform of the re-measured pressure pulses in to waveform cycles and cycle segments, marking each of the waveform segments, comparing each individual waveform segment, and determining from the cycle to cycle pressure variations the carbon buildup in the air induction system after cleaning.