Knocking detection apparatus and internal combustion engine control apparatus

a technology for internal combustion engines and detection apparatuses, which is applied in the direction of electric control, machines/engines, instruments, etc., can solve the problems of inability to accurately detect knocking, abnormal noise in engines or damage to engines, and changes in the frequency of knocking, so as to improve the intensity of smoothing processing, reduce the effect of erroneous determination of knocking during transition and enhanced follow-up performan

Active Publication Date: 2021-07-08
HITACHI ASTEMO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0015]The knocking detection apparatus according to the present invention can increase the intensity of smoothing processing since follow-up performance in calculating a background level during transient operation is enhanced. As a result, erroneous determination of knocking during transition can be reduced, and knock detection accuracy can be improved regardless of whether an engine is in steady operation or transient operation.

Problems solved by technology

This may cause abnormal noise in an engine or damage to the engine due to excessive pressure in the combustion chamber.
The method for detecting occurrence of knocking by using only the single resonant frequency component, as disclosed in PTL 1, has a problem in that knocking cannot be accurately detected since the background level becomes large at high-speed rotation, and a resonant frequency of knocking changes as various factors of an engine change.

Method used

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  • Knocking detection apparatus and internal combustion engine control apparatus
  • Knocking detection apparatus and internal combustion engine control apparatus
  • Knocking detection apparatus and internal combustion engine control apparatus

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

[0084]The control unit (knocking detection apparatus) 9 according to the first embodiment calculates a weighted average by preliminarily subtracting an estimated value of the background level from the frequency component of the vibration sensor 151, and then, adds back the estimated value of the background level. As a result, transient variation of the background level is excluded from the weighted average processing. Therefore, it is possible to reduce a lag in calculation associated with the transient variation, and also reduce erroneous detection of knocking due to the lag in calculation. Therefore, it is possible to optimally control ignition timing in every operating state.

second embodiment

[0085]FIG. 11 is an image diagram of map data describing estimated values of a background level. The map data describes a corresponding relationship among engine speed (or a change rate thereof), an engine load (or a change rate thereof), and the background level (or a correction value for a specified level). In the example shown in FIG. 11, the background level tends to increase on the high rotation side / high load side.

[0086]As another method of estimating the background level, the following method may be adopted. A CPU 29 obtains sensor signals indicating loading states, and estimates an operating state based on the signals. Examples of the sensor signals include a throttle sensor signal (a signal indicating throttle opening degree), an intake air quantity signal (a signal indicating an intake air quantity for an engine), a fuel injection pulse signal (a pulse signal for instructing fuel injection), and an intake pipe pressure signal (a signal indicating pressure inside an intake ...

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Abstract

Provided is a knocking detection apparatus capable of reducing erroneous determination of knocking during transition, and improving knocking detection accuracy regardless of whether an engine is in steady operation or transient operation. A knocking detection apparatus according to the present invention estimates a background level based on an operating state of an internal combustion engine, and calculates a knocking determination index by using the estimated value.

Description

TECHNICAL FIELD[0001]The present invention relates to technology for detecting knocking of an internal combustion engine.BACKGROUND ART[0002]Depending on conditions, preignition may occur in a combustion chamber of an internal combustion engine. This may cause abnormal noise in an engine or damage to the engine due to excessive pressure in the combustion chamber. In order to prevent the above-described problems, it is necessary to accurately detect knocking.[0003]As is well known, knocking is the following phenomenon. Vibration of gas in a combustion chamber is caused by self-ignition of unburned gas at a terminal section of the combustion chamber, and the vibration is transmitted to an engine body. It is desirable to avoid knocking whenever possible since knocking causes, for example, loss in energy generated by the engine (reduction in output), impact on each part of the engine, and also a decrease in fuel consumption. Therefore, it is essential to accurately detect occurrence of ...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): F02D41/14F02P5/152
CPCF02D41/1497F02P5/152F02D2200/0618F02D2200/0406F02D2200/0404F02D35/027F02D41/18F02D2041/288F02D2200/025F02P3/02F02P5/1521F02P7/021F02P7/07G01H3/08Y02T10/40
Inventor AKAGI, YOSHIHIKOSEIMIYA, MASASHIASANO, SEIJIKATOU, WATARUNUKUI, MASANORISATO, MASAHIRO
Owner HITACHI ASTEMO LTD
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