JP2011241683A - Engine failure pre-sensing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine failure pre-sensing system enabling prediction of the future occurrence of a failure in a stage where the failure has not yet occurred in an engine.SOLUTION: The engine failure pre-sensing system includes acceleration sensors 10, 11 arranged at proper positions on a diesel engine 1 (the engine), and an arithmetic unit 14 storing frequency analysis data of acceleration to be detected depending on the operating condition of the brand-new diesel engine 1 by the acceleration sensors 10, 11, as base data. The arithmetic unit 14 is configured to perform frequency analysis of acceleration actually measured by the acceleration sensors 10, 11 and compare the result with the base data corresponding to the operating condition during measurement, and to predict the future occurrence of a failure when any frequency component among frequency analysis results of the actually measured acceleration exceeds an acceptable value and is different from the base data.

Description

  The present invention relates to an engine failure pre-sensing system.

  In general, the majority of failures that occur in an engine are thought to be caused by wear and breakage in various parts of the engine due to abnormal loads and stress due to resonance. Is firmly assembled based on an appropriate design so that resonance does not occur.

  In other words, a new engine at the time of shipment is properly designed and assembled so that resonance does not occur.However, if the bolt is loosened due to deterioration over time, etc. An unexpected resonance may occur, and this resonance has caused the engine to fail.

  As prior art document information related to the present invention, there is the following Patent Document 1 and the like.

JP 2004-263648 A

  However, even if there is resonance in the engine, the driver does not notice the engine abnormality until the engine actually fails, so the driver notices the engine abnormality at the stage where the engine has not yet failed. Although it is desired to construct a system to make such a system, at present, such a system has not been put to practical use.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine failure prior detection system capable of predicting a future failure occurrence at a stage where the engine has not yet failed.

  The present invention includes an acceleration sensor disposed at an appropriate position of the engine, and an arithmetic device that stores, as base data, acceleration frequency analysis data that should be detected by the acceleration sensor according to the operating state of a new engine. The arithmetic unit performs frequency analysis on the acceleration actually measured by the acceleration sensor and compares it with the base data corresponding to the driving state at the time of measurement, and any frequency of the frequency analysis result of the acceleration actually measured with respect to the base data The present invention relates to an engine failure pre-sensing system that is configured to predict a future occurrence of a failure when components differ beyond an allowable value.

  Thus, in this way, even if there is no significant difference in the actual acceleration measured by the acceleration sensor between when the engine is resonant and when there is no resonance, the measured acceleration If a specific frequency component that appears at a relatively large level is compared when the frequency is analyzed, the level appears as a significant difference depending on the presence or absence of engine resonance, so comparison with base data based on a new engine that does not cause resonance If any of the frequency components exceeds the permissible value, it is determined that the engine has a resonance caused by aging, and a future failure due to this resonance is predicted. become.

  Further, in the present invention, acceleration sensors are arranged at points A and B that are spaced apart from each other in the engine, and the measured acceleration at each of the points A and B is analyzed to correspond to the driving state at the time of measurement. Are compared with the respective base data, and the frequency analysis result of the actual acceleration at the point A is subtracted from the frequency analysis result of the actual acceleration at the point A to obtain the point B from the base data of the A point corresponding to the driving state at the time of measurement. Compared with the base data obtained by subtracting the base data, the frequency analysis result of the measured acceleration at the point A differs from the base data by exceeding the allowable value, or the measured acceleration at the point B Is any frequency component of the frequency analysis result of the difference from the base data exceeding the allowable value, or is the frequency analysis result of the measured acceleration at point A? Whether any frequency component of the calculation result obtained by subtracting the frequency analysis result of the acceleration actually measured at the point B differs from the base data obtained by subtracting the base data of the point B from the base data of the point A exceeding the allowable value. In such a case, it is preferable that the arithmetic unit is configured to predict a future failure occurrence.

  In this way, it is possible to determine not only the resonance at points A and B, but also the presence or absence of resonance at an intermediate position between points A and B. More specifically, A Compared with the base data obtained by subtracting the base data of point B from the base data of point A corresponding to the operating state at the time of measurement when resonance occurs at an intermediate position between point B and point B, Any frequency component in the calculation result obtained by subtracting the frequency analysis result of the actual acceleration at the point B from the frequency analysis result of the actual acceleration at the point A will be different from the allowable value.

  According to the engine failure prior detection system of the present invention described above, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, the acceleration measured by the acceleration sensor is frequency-analyzed and compared with the base data corresponding to the driving state at the time of measurement. Therefore, it is possible to predict whether or not a future failure will occur at a stage where no failure has occurred in the engine.

  (II) According to the invention described in claim 2 of the present invention, the acceleration sensors are arranged at the points A and B which are separated from each other in the engine, so that only the resonance at the points A and B is determined. In addition, since it is possible to determine the presence or absence of resonance at an intermediate position between the A point and the B point, the A point and the B point that sandwich the relevant part between places where it is difficult to directly place the acceleration sensor. If set, it is possible to determine the presence or absence of resonance at a location where it is difficult to directly place the acceleration sensor, and to predict future failure at that location.

It is the schematic which shows an example of the form which implements this invention. It is a graph which shows an example of the frequency analysis data of acceleration.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an example of an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a diesel engine (engine) equipped with a turbocharger 2, and intake air 4 guided from an air cleaner 3 is an intake pipe 5. And the intake air 4 pressurized by the compressor 2a is sent to the intercooler 6 to be cooled, and further led from the intercooler 6 to an intake manifold (not shown). The exhaust gas 7 discharged from each cylinder is sent to the turbine 2b of the turbocharger 2 through the exhaust manifold 8 to drive the turbine 2b. The exhaust gas 7 is discharged to the outside of the vehicle through the exhaust pipe 9.

  With respect to such a diesel engine 1, in the present embodiment, the acceleration sensor 10 is installed with the high rigidity portion in the front position of the upper part of the cylinder head of the diesel engine 1 as the point A, and the mounted auxiliary machine ( Another acceleration sensor 11 is installed with a portion where many clutches, missions, cells, injection pumps, etc.) are assembled around the point B, and the measured accelerations by these acceleration sensors 10, 11 are detected signals 12, 13. An input arithmetic unit 14 is provided at a required place.

  The arithmetic unit 14 stores frequency analysis data of acceleration that should be detected according to the driving state of the new diesel engine 1 by the acceleration sensors 10 and 11, as base data. The calculation result obtained by subtracting the base data of point B from the base data is also stored as base data.

  Here, the frequency analysis data of acceleration is obtained by analyzing the components of acceleration according to frequency as shown in the graph of FIG. Such frequency analysis data is measured and averaged for new diesel engines 1 mounted on a plurality of pre-shipment automobiles verified not to cause resonance, and is stored in the arithmetic unit 14 as base data. ing.

  That is, even if there is no significant difference in the actual acceleration measured by the acceleration sensors 10 and 11 between the case where the resonance occurs in the diesel engine 1 and the case where the resonance does not occur, the actual acceleration is analyzed by frequency analysis. If a specific frequency component appearing at a relatively large level is compared, the level varies by about 10 dB or more depending on the presence or absence of resonance of the diesel engine 1 and appears as a significant difference. It is possible to determine whether or not it has occurred.

  The calculation device 14 includes a detection signal 15 indicating the rotational speed of the diesel engine 1 derived from a control device for the diesel engine 1 (not shown), and a detection signal 16 indicating the fuel injection amount (indicated value) of the diesel engine 1. Is input, and the driving state when the acceleration is detected by each of the acceleration sensors 10 and 11 is always grasped.

  In the arithmetic unit 14, the measured acceleration at each of the points A and B is frequency-analyzed and compared with the respective base data corresponding to the driving state at the time of measurement, and the frequency of the measured acceleration at the point A is calculated. The frequency analysis result of the acceleration actually measured at the point B is subtracted from the analysis result and compared with the base data obtained by subtracting the base data at the point B from the base data at the point A corresponding to the driving state at the time of measurement.

  That is, a two-dimensional control map of the rotational speed of the diesel engine 1 and the fuel injection amount (instruction value) is created in the arithmetic unit 14, and the current rotational speed of the diesel engine 1 and the fuel injection amount (instruction value). ) Is read out, the base data in the operating state is read from the two-dimensional control map, and the frequency components appearing at a relatively large level in the read base data and the frequency analysis result of the measured acceleration. Comparisons are made within the computing device 14 and differences between them are detected.

  Further, in the arithmetic unit 14, the frequency analysis result of the measured acceleration at the point A is different from the frequency analysis result of the measured acceleration at the point A exceeding the allowable value with respect to the base data. Among the calculation results obtained by subtracting the frequency analysis result of the actual acceleration at the point A from the frequency analysis result of the actual acceleration at the point A If any of the frequency components differ beyond the allowable value with respect to the base data obtained by subtracting the base data of point B from the base data of point A, the occurrence of a future failure is predicted. Yes.

  Here, when the influence of the drive system is large in reading out the base data in the arithmetic unit 14, one axis of the gear stage of the mission is added to the two axes of the rotational speed of the diesel engine 1 and the fuel injection amount (indicated value). The base data may be read out as a three-dimensional control map to which is added, and in this way, it is possible to predict future failure occurrence with higher accuracy. In addition, when reading base data from such a three-dimensional control map, the detection signal 17 indicating the gear stage of the mission may be input to the arithmetic unit 14.

  Thus, in this way, there is no significant difference between the actual acceleration measured by the acceleration sensors 10 and 11 between the case where resonance occurs in the diesel engine 1 and the case where resonance does not occur. If a specific frequency component that appears at a relatively large level when the measured acceleration is subjected to frequency analysis is compared, the level appears as a significant difference depending on the presence or absence of resonance of the diesel engine 1, so the acceleration at point A and point B Is measured by the acceleration sensors 10 and 11, and frequency analysis is performed. If any frequency component exceeds the allowable value in comparison with the base data corresponding to the driving state at the time of measurement, the diesel engine 1 Therefore, it is determined that a resonance due to aged deterioration has occurred, and a future failure due to this resonance is predicted.

  In addition to the determination of resonance at points A and B, it is possible to determine the presence or absence of resonance at an intermediate position between points A and B. More specifically, points A and B can be determined. Compared with the base data obtained by subtracting the base data of point B from the base data of point A corresponding to the operating state at the time of measurement when resonance occurs at the intermediate position between Any frequency component of the calculation result obtained by subtracting the frequency analysis result of the actual acceleration at the point B from the frequency analysis result of the acceleration of the current value exceeds the allowable value.

  Therefore, according to the embodiment, the acceleration measured by the acceleration sensors 10 and 11 is frequency-analyzed and compared with the base data corresponding to the driving state at the time of measurement. Since it is possible to determine whether or not resonance has occurred, it is possible to predict the future occurrence of failure at a stage where no failure has occurred in the diesel engine 1 yet.

  Moreover, since the acceleration sensors 10 and 11 are arranged at the points A and B that are spaced apart from each other in the diesel engine 1, not only the resonance determination at the points A and B but also the points A and B are sandwiched. Since it is also possible to determine the presence or absence of resonance at the intermediate position, the acceleration sensor 10 and 11 can be determined by setting the A point and the B point so as to sandwich the location between locations where it is difficult to directly place the acceleration sensors 10 and 11. It is possible to predict the occurrence of a future failure at the location by determining the presence or absence of resonance at a location where it is difficult to directly place 10 and 11.

  The engine failure pre-sensing system according to the present invention is not limited to the above-described embodiment, and a knocking sensor or a G sensor may be used for each acceleration sensor. Of course, various changes can be made without departing from the scope of the present invention.

1 Diesel engine (engine)
DESCRIPTION OF SYMBOLS 10 Acceleration sensor 11 Acceleration sensor 14 Calculation apparatus

Claims (2)

  An acceleration sensor disposed at an appropriate position of the engine, and an arithmetic device that stores, as base data, acceleration frequency analysis data that should be detected by the acceleration sensor in accordance with the driving state of a new engine. The frequency analysis of the acceleration measured by the acceleration sensor is compared with the base data corresponding to the driving state at the time of measurement, and any frequency component of the frequency analysis result of the acceleration measured for the base data is an allowable value. An engine failure pre-sensing system configured to predict a future failure if there is a difference between   Accelerometers are arranged at points A and B that are spaced apart from each other in the engine, and the measured acceleration at each of the points A and B is frequency-analyzed and compared with the respective base data corresponding to the driving state at the time of measurement. At the same time, the base frequency data obtained by subtracting the base data of the point B from the base data of the point A corresponding to the driving state at the time of measurement by subtracting the frequency analysis result of the actual acceleration at the point B from the frequency analysis result of the actual acceleration at the point A Compared with the data, whether any frequency component of the frequency analysis result of the measured acceleration at the point A differs from the base data beyond the allowable value, or of the frequency analysis result of the measured acceleration at the point B Whether any frequency component differs from the base data by exceeding the allowable value, or the measured acceleration at the point B from the frequency analysis result of the measured acceleration at the point A If any frequency component of the calculation result obtained by subtracting the frequency analysis result is different from the base data obtained by subtracting the base data of point B from the base data of point A exceeding the allowable value, the future The engine failure pre-sensing system according to claim 1, wherein the arithmetic unit is configured to predict a typical failure occurrence.

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