JPH02138850A - Knocking detection for internal combustion engine - Google Patents
Knocking detection for internal combustion engineInfo
- Publication number
- JPH02138850A JPH02138850A JP63290244A JP29024488A JPH02138850A JP H02138850 A JPH02138850 A JP H02138850A JP 63290244 A JP63290244 A JP 63290244A JP 29024488 A JP29024488 A JP 29024488A JP H02138850 A JPH02138850 A JP H02138850A
- Authority
- JP
- Japan
- Prior art keywords
- light
- knocking
- combustion
- wavelength
- intensity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 49
- 238000001514 detection method Methods 0.000 title description 5
- 238000000034 method Methods 0.000 claims abstract description 10
- 239000013307 optical fiber Substances 0.000 abstract description 6
- 241000251468 Actinopterygii Species 0.000 abstract 1
- 230000003287 optical effect Effects 0.000 description 13
- 238000010586 diagram Methods 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000007526 fusion splicing Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
Landscapes
- Testing Of Engines (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、内燃機関のノッキング検知方法に関する。[Detailed description of the invention] (Industrial application field) The present invention relates to a knocking detection method for an internal combustion engine.
（従来の技術）
内燃機関、例えばガソリンエンジンのバッキングの発生
を検知する方法として、従来第２図に示すものが知られ
ている。この検知方法は、エンジン２０の燃焼室２１内
の燃焼光を光ファイノ弗２で燃焼室２１外へ導出し、適
宜のピーク波長を有する光学フィルタ２３で濾波・分光
（分波）した光の強度を光センサ２４で検出し、光セン
サ２４による検出信号の大小でノッキングの発生を検知
するものである。(Prior Art) As a method for detecting the occurrence of backing in an internal combustion engine, for example, a gasoline engine, the method shown in FIG. 2 is conventionally known. In this detection method, the combustion light in the combustion chamber 21 of the engine 20 is guided out of the combustion chamber 21 by an optical filter 2, and the intensity of the light is filtered and separated by an optical filter 23 having an appropriate peak wavelength. is detected by the optical sensor 24, and the occurrence of knocking is detected based on the magnitude of the detection signal from the optical sensor 24.
（発明が解決しようとする課題）
上記のように、燃焼光を光学的にモニタすることによっ
てノッキングの発生を検知する方法は、エンジンの運転
条件が一定の場合には使用可能である。(Problems to be Solved by the Invention) As described above, the method of detecting the occurrence of knocking by optically monitoring combustion light can be used when the operating conditions of the engine are constant.
しかしながら、本発明者らがエンジンの運転条件を種々
変化させて燃焼光の強度とその波長分布との関係を調べ
てみたところ、縦軸に燃焼光の強度（１）を、横軸に波
長（λ）をとって表した第３図（１）〜（３）のように
、正常燃焼時（図中実線Ａで表示）とノッキングが発生
する場合（図中破線Ｂで表示）とでは、燃焼光の分光特
性が非常に変化するということが確認された。However, when the present inventors investigated the relationship between the intensity of combustion light and its wavelength distribution by varying engine operating conditions, they found that the vertical axis represents the intensity of combustion light (1), and the horizontal axis represents the wavelength (1). λ), as shown in Figure 3 (1) to (3), the combustion It was confirmed that the spectral properties of light change significantly.
このように、実際にはエンジンの運転条件が種々変化し
、これに伴ってエンジンの回転数、負荷。In this way, in reality, the operating conditions of the engine change in various ways, and the engine speed and load change accordingly.
空燃比等が変動するため、燃焼光の強度等の特性が様々
に変化している。したがって、上記のように単一の光を
用いた方法では、ノンキングの発生を検知することが難
しかった。As the air-fuel ratio etc. fluctuate, characteristics such as the intensity of combustion light vary. Therefore, with the method using a single light as described above, it is difficult to detect the occurrence of non-king.
本発明は上述の点に鑑みてなされたもので、内燃機関に
おけるノッキングの発生を的確に検知することができる
方法を提供することを目的とする。The present invention has been made in view of the above points, and an object of the present invention is to provide a method that can accurately detect the occurrence of knocking in an internal combustion engine.
（課題を解決するための手段）
上記目的を達成するため本発明者らは、エンジンの運転
条件による燃焼光の強度とその波長分布とに関する上記
第３図に示す結果について鋭意検討した。その結果、燃
焼光の強度や波長分布は運転条件によって変化するが、
第３図から明らかなように、燃焼光における波長λ２の
成分は、正常燃焼時（Ａ）とノッキングの場合（Ｂ）と
で光強度（Ｉ）の差が小さく、また第３図（１）、 （
３）のように、正常燃焼時の方がノッキングの場合に比
べて光強度（１）が大きくなる場合がある。これに対し
て波長λ１の成分は、正常燃焼時とノッキングの場合と
で光強度（１）の差が大きく、しかもノッキングの場合
の光強度（１）は正常燃焼時よりも大きく、波長λ、と
波長λ２ （λ１〈λ２）の光を用いると、運転条件が
変化しても、正常燃焼時とノッキングの場合とを明確に
区別して検知できるという知見を得た。(Means for Solving the Problems) In order to achieve the above object, the present inventors have intensively studied the results shown in FIG. 3 above regarding the intensity of combustion light and its wavelength distribution depending on engine operating conditions. As a result, the intensity and wavelength distribution of combustion light change depending on the operating conditions,
As is clear from Fig. 3, the difference in light intensity (I) of the wavelength λ2 component of the combustion light is small between normal combustion (A) and knocking (B), and Fig. 3 (1) , (
As shown in 3), the light intensity (1) may be higher during normal combustion than in the case of knocking. On the other hand, for the component of wavelength λ1, there is a large difference in light intensity (1) between normal combustion and knocking, and the light intensity (1) in knocking is greater than that in normal combustion. It was found that by using light with a wavelength of λ2 (λ1<λ2), it is possible to clearly distinguish between normal combustion and knocking, even if the operating conditions change.
本発明者らはかかる知見に基づいて本発明をなすに到っ
たのである。即ち、本発明は、燃焼室内の波長の異なる
２種類の燃焼光を採光し、これらの光の光強度差を測定
し、測定した光強度差からノッキングの発生を検知する
ものである。The present inventors have arrived at the present invention based on such knowledge. That is, the present invention collects two types of combustion light having different wavelengths in a combustion chamber, measures the difference in light intensity of these lights, and detects the occurrence of knocking from the measured difference in light intensity.
（作用）
波長の異なる長短２種類の燃焼光（波長λ１゜λ２）の
強度を測定し、測定した光強度差を所定闇値と比較する
と、ノッキングの場合と正常燃焼時とが明確に区別され
る。(Function) When the intensity of two types of combustion light (long and short with different wavelengths) (wavelengths λ1 and λ2) is measured and the measured light intensity difference is compared with a predetermined darkness value, knocking and normal combustion can be clearly distinguished. Ru.
（実施例）
以下本発明の一実施例を第１図に基づいて詳細に説明す
る。(Example) An example of the present invention will be described in detail below with reference to FIG.
エンジン１はシリンダ２内にピストン３が気密かつ上下
動自在に配置され、シリンダ２の上部には排気弁４を設
けた排気ポー１−５と、吸気弁６を設けた吸気ボート７
が夫々開口している。尚、８はピストンリングである。The engine 1 has a piston 3 arranged in a cylinder 2 airtightly and movable up and down, and the upper part of the cylinder 2 has an exhaust port 1-5 provided with an exhaust valve 4, and an intake boat 7 provided with an intake valve 6.
are open respectively. In addition, 8 is a piston ring.
そして、シリンダ２の上部には、先端に魚眼レンズ１０
を設けた光ファイバ１１が、シリンダ２の壁面から燃焼
室９に、その魚眼レンズ１ｏを突出させて配設されてい
る。この魚眼レンズ１ｏは、ピストン３の上端面とシリ
ンダ２の内壁面との間に形成される燃焼室９内全体がら
燃焼光が採光できるようにするものである。At the top of the cylinder 2, there is a fisheye lens 10 at the tip.
An optical fiber 11 is disposed from the wall surface of the cylinder 2 into the combustion chamber 9 with its fisheye lens 1o protruding. This fisheye lens 1o allows combustion light to be illuminated throughout the combustion chamber 9 formed between the upper end surface of the piston 3 and the inner wall surface of the cylinder 2.
光ファイバ１１の後端は、光ファイバを融着接合等によ
り接合することにより、二股に分岐しており、一方の端
部１１ａは燃焼光を中心波長λ１の光を濾波・分光する
光学フィルタ、例えば干渉フィルタ１２に、他方の端部
１１ｂは燃焼光を干渉フィルタ１２よりも更に長波長の
中心波長λ２（λ１〈λ２）の光を濾波・分光する干渉
フィルタ１３に、夫々対向配置されている。また、干渉
フィルタ１２には光センサ１４が、干渉フィルタ１３に
は光センサ１５が、夫々隣接して配置されている。そし
て、光センサエ４はオペアンプＩ６の正極端子に、光セ
ンサ１５はオペアンプ１６の負極端子に夫々接続されて
いる。これにより、各センサ１４．１５からの出力信号
はオペアンプ１６に入力され、オペアンプ１６で差動増
幅されてノック信号Ｓとして出力される。The rear end of the optical fiber 11 is branched into two by joining the optical fibers by fusion splicing or the like, and one end 11a is provided with an optical filter that filters and separates the combustion light with a center wavelength λ1; For example, the other end portion 11b is disposed opposite to the interference filter 12, and the other end portion 11b is disposed to face the interference filter 13, which filters and separates the combustion light into light having a center wavelength λ2 (λ1<λ2), which is a longer wavelength than the interference filter 12. . Further, an optical sensor 14 and an optical sensor 15 are arranged adjacent to the interference filter 12 and the interference filter 13, respectively. The optical sensor 4 is connected to the positive terminal of the operational amplifier I6, and the optical sensor 15 is connected to the negative terminal of the operational amplifier 16. As a result, the output signals from each sensor 14, 15 are input to the operational amplifier 16, differentially amplified by the operational amplifier 16, and output as a knock signal S.
そして、以上の構成に基づくノッキングの検知方法につ
いて述べると、先ず燃焼室９内の燃焼光を魚眼レンズＩ
Ｏで採光する。To describe the method for detecting knocking based on the above configuration, first, combustion light in the combustion chamber 9 is detected through a fisheye lens I.
Lighting is done with O.
次いで、魚眼レンズ１０で採光した燃焼光を光ファイバ
１１により燃焼室９外へ導出すると共にその端部１１ａ
、ｌｌｂに分岐する。これらの分岐された燃焼光を夫々
干渉フィルタ１２と１３に入射させる。すると、分岐さ
れた各燃焼光は、干渉フィルタ１２で波長λ１の光に、
干渉フィルタ１３で波長λ２ （λ１〈λ２）の光に、
夫々濾波・分光され、波長λ１の光は光センサ１４に、
波長λ２の光は光センサ１５に夫々入射される。Next, the combustion light collected by the fisheye lens 10 is led out of the combustion chamber 9 through an optical fiber 11, and its end 11a
, llb. These branched combustion lights are made incident on interference filters 12 and 13, respectively. Then, each branched combustion light is converted into light of wavelength λ1 by the interference filter 12,
The interference filter 13 converts the light of wavelength λ2 (λ1<λ2) into
The light with wavelength λ1 is filtered and spectrally transmitted to the optical sensor 14,
The light having the wavelength λ2 is incident on the optical sensor 15, respectively.
光センサ１４，１５は夫々入射光の強度に対応した出力
信号をオペアンプ１６の正・負極に入力し、オペアンプ
１Ｇではこれらの出力信号を差動増幅して、ノック信号
Ｓとして出力する。The optical sensors 14 and 15 respectively input output signals corresponding to the intensity of the incident light to the positive and negative poles of the operational amplifier 16, and the operational amplifier 1G differentially amplifies these output signals and outputs them as a knock signal S.
そして、このノック信号Ｓの所定闇値との差に４゜ 基づいてノッキングの発生の有無を判断するのである。Then, the difference between this knock signal S and the predetermined darkness value is 4°. Based on this, it is determined whether or not knocking has occurred.
（発明の効果）
本発明の内燃機関のノッキング検知方法は、燃焼室内の
波長の異なる２種類の燃焼光を採光し、これらの光の光
強度差を測定し、測定した光強度差からノッキングの発
生を検知するので、単一の光でノッキングの発生を検知
する従来の方法に比べ、より高い精度でノッキングの発
生を検知することができる。(Effects of the Invention) The method for detecting knocking in an internal combustion engine of the present invention collects two types of combustion light with different wavelengths in a combustion chamber, measures the light intensity difference between these lights, and detects knocking from the measured light intensity difference. Since the occurrence of knocking is detected, it is possible to detect the occurrence of knocking with higher accuracy than the conventional method of detecting the occurrence of knocking using a single light.
第１図は本発明のノッキング検知方法の一実施例を示す
システム図、第２図は従来の測定方法を示すシステム図
、第３図はエンジンの運転条件の相違による、燃焼光の
強度とその波長分布との関係を示す分光特性図である。
１・・・エンジン、２・・・シリンダ、３・・・ピスト
ン、９・・・燃焼室、１０・・・魚眼レンズ、１１・・
・光ファイバ、１２．１３・・・干渉フィルタ、１４．
１５・・・光センサ、１６・・・オペアンプ。Fig. 1 is a system diagram showing an embodiment of the knocking detection method of the present invention, Fig. 2 is a system diagram showing a conventional measuring method, and Fig. 3 shows the intensity of combustion light and its variation due to differences in engine operating conditions. FIG. 3 is a spectral characteristic diagram showing the relationship with wavelength distribution. DESCRIPTION OF SYMBOLS 1...Engine, 2...Cylinder, 3...Piston, 9...Combustion chamber, 10...Fisheye lens, 11...
- Optical fiber, 12.13... Interference filter, 14.
15... Optical sensor, 16... Operational amplifier.
Claims (1)
らの光の光強度差を測定し、測定した光強度差からノッ
キングの発生を検知することを特徴とする内燃機関のノ
ッキング検知方法。A method for detecting knocking in an internal combustion engine, comprising: collecting two types of combustion light having different wavelengths in a combustion chamber, measuring a difference in light intensity between these lights, and detecting occurrence of knocking from the measured difference in light intensity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63290244A JPH02138850A (en) | 1988-11-18 | 1988-11-18 | Knocking detection for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63290244A JPH02138850A (en) | 1988-11-18 | 1988-11-18 | Knocking detection for internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02138850A true JPH02138850A (en) | 1990-05-28 |
Family
ID=17753624
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63290244A Pending JPH02138850A (en) | 1988-11-18 | 1988-11-18 | Knocking detection for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02138850A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012007514A (en) * | 2010-06-23 | 2012-01-12 | Nippon Soken Inc | System for detecting combustion state of internal combustion engine |
-
1988
- 1988-11-18 JP JP63290244A patent/JPH02138850A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012007514A (en) * | 2010-06-23 | 2012-01-12 | Nippon Soken Inc | System for detecting combustion state of internal combustion engine |
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