JPH06336948A - Misfire detecting device for internal combustion engine - Google Patents
Misfire detecting device for internal combustion engineInfo
- Publication number
- JPH06336948A JPH06336948A JP12698693A JP12698693A JPH06336948A JP H06336948 A JPH06336948 A JP H06336948A JP 12698693 A JP12698693 A JP 12698693A JP 12698693 A JP12698693 A JP 12698693A JP H06336948 A JPH06336948 A JP H06336948A
- Authority
- JP
- Japan
- Prior art keywords
- misfire
- internal combustion
- combustion engine
- variation amount
- amount
- 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.)
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- Testing Of Engines (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、特に連続失火を検出で
きる内燃機関用失火検出装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a misfire detection device for an internal combustion engine which can detect continuous misfires.
【０００２】[0002]
【従来の技術】従来、内燃機関に発生する失火を検出す
るものとして、失火発生時には内燃機関の燃焼室内で完
全な燃焼が得られず、内燃機関の回転数（機関回転数）
が低下することから、１点火サイクル内の少なくとも２
点で機関回転数を検出して機関回転数変動量を求め、機
関回転数変動量と内燃機関状態から設定される失火検出
値とを比較して、機関回転数変動量が失火検出値より大
きくなったときに失火と判別する装置がある（例えば、
特開昭６１ー２５８９５５号公報）。2. Description of the Related Art Conventionally, as a means for detecting a misfire occurring in an internal combustion engine, complete combustion cannot be obtained in a combustion chamber of the internal combustion engine when the misfire occurs, and the engine speed (engine speed)
Is reduced to at least 2 in one ignition cycle.
Point to detect the engine speed fluctuation amount to obtain the engine speed fluctuation amount, compare the engine speed fluctuation amount with the misfire detection value set from the internal combustion engine state, and determine that the engine speed fluctuation amount is greater than the misfire detection value. There is a device that distinguishes misfire when it becomes (for example,
JP-A-61-258955).
【０００３】[0003]
【発明が解決しようとする課題】上述した手法による失
火の判別装置においては、失火が発生していない正常燃
焼時における点火周期毎（１燃焼周期毎）の平均回転数
ωn が、常に一定であるということを前提にして失火判
別するものである。しかしながら、気筒をクランクシャ
フトを中心としてＶ字型に配したＶ型内燃機関では、内
燃機関のピストンとクランクシャフトとを連結させる連
結棒（コネクティングロッド）が、クランクシャフトに
対して所定の角度傾いて配設されていることから、正常
燃焼時においても各気筒の慣性力の影響などにより内燃
機関の平均回転数ωn は一定にならず、平均回転数ωn
は３６０°ＣＡ（クランク角）周期の変動が発生すると
いうことが知られている。In the misfire discriminating apparatus according to the above-described method, the average rotational speed ω n for each ignition cycle (every one combustion cycle) during normal combustion in which no misfire occurs is always constant. Misfire is determined on the assumption that there is. However, in a V-type internal combustion engine in which the cylinders are arranged in a V shape with the crankshaft as the center, a connecting rod that connects the piston of the internal combustion engine and the crankshaft is inclined at a predetermined angle with respect to the crankshaft. Since the internal combustion engine is disposed, the average rotation speed ω n of the internal combustion engine does not become constant due to the influence of the inertial force of each cylinder even during normal combustion, and the average rotation speed ω n
Is known to cause a fluctuation of 360 ° CA (crank angle) cycle.
【０００４】さらに、Ｖ型内燃機関に限らず直列内燃機
関においても、直列内燃機関に配設されているクランク
角センサの製造行程でのばらつきやクランク軸の機械的
ながた等が原因となり上述したような回転角３６０°Ｃ
Ａ周期の変動が発生するおそれがある。したがって、上
述した従来の失火判別方法では、各気筒の燃焼のばらつ
き等の影響により平均回転数ωn の変動が生じた場合、
実際には内燃機関に失火が発生していないにも拘らず、
失火発生と誤判定してしまうおそれがあった。Further, not only in the V-type internal combustion engine, but also in the serial internal combustion engine, variations in the manufacturing process of the crank angle sensor arranged in the serial internal combustion engine, mechanical rattling of the crankshaft, and the like cause the above problems. Rotation angle 360 ° C
There is a possibility that the A cycle may change. Therefore, in the above-described conventional misfire determination method, when the average rotation speed ω n fluctuates due to the influence of variations in combustion of each cylinder,
Despite the fact that the internal combustion engine is not misfiring,
There was a risk of misjudging that a misfire had occurred.
【０００５】上記問題を解決するために、今回求めた連
続する２つの気筒間の回転変動偏差を、３６０°ＣＡあ
るいは７２０°ＣＡ前に求めた連続する２つの気筒間の
回転変動偏差と比較して失火を判定すれば、機関回転に
同期する回転変動を取り除く方法も考えられる（例え
ば、特開平４−３６５９５８号公報）。ただし、この方
法は内燃機関所定回転毎の回転変動偏差を比較するため
に、失火を検出された気筒から３６０°ＣＡ後の気筒が
連続失火しても回転変動偏差としては現れないために正
常燃焼と判定してしまい、正確な失火判定ができないと
いう問題がある。In order to solve the above problem, the rotational fluctuation deviation between the two consecutive cylinders obtained this time is compared with the rotational fluctuation deviation between the two consecutive cylinders obtained before 360 ° CA or 720 ° CA. If misfire is determined by determining the misfire, a method of removing the rotation fluctuation synchronized with the engine rotation can be considered (for example, JP-A-4-365958). However, since this method compares the rotational fluctuation deviations for each predetermined rotation of the internal combustion engine, even if a cylinder after 360 ° CA from the cylinder in which misfire is detected does not continuously appear as a rotational fluctuation deviation, normal combustion does not occur. Therefore, there is a problem that an accurate misfire determination cannot be made.
【０００６】そこで、本発明は機関回転に同期する変動
による失火誤判定を防ぐとともに、特定気筒の連続失火
も正確に検出することを目的とする。Therefore, an object of the present invention is to prevent misfire misjudgment due to fluctuations synchronized with engine rotation and to accurately detect continuous misfire of a specific cylinder.
【０００７】[0007]
【課題を解決するための手段】上記目的を達成するため
に本発明による内燃機関用失火検出装置は図１に示す如
く、内燃機関の回転に応じて所定の回転角度毎に回転信
号を出力する回転信号出力手段と、前記回転信号出力手
段の出力信号に基づき各気筒の爆発行程における所定回
転角度間の回転に要した期間を計測することにより定ま
る実測値を求める実測値演算手段と、前記実測値演算手
段の演算結果に基づいて、前記爆発行程が連続する２つ
の気筒間の実測値の偏差を求めることにより第１の変動
量を演算する第１の変動量演算手段と、前記回転信号出
力手段および前記実測値演算手段からの情報に基づい
て、前記第１の変動量演算手段で演算された今回の前記
第１の変動量と、前記内燃機関のクランク角で３６０度
の整数倍回転前に演算された前記第１の変動量との偏差
を求めることにより第２の変動量を演算する第２の変動
量演算手段と、前記第１の変動量と前記第２の変動量と
に基づいて前記内燃機関の失火を検出する失火検出手段
と、前記失火検出手段により失火状態を検出してから、
前記第１の変動量と前記第２の変動量とに基づいて、前
記内燃機関の失火状態から正常燃焼状態への復帰を検出
する正常復帰検出手段と、前記失火検出手段により失火
状態を検出してから、前記正常復帰検出手段により前記
内燃機関が正常燃焼状態に復帰したことを検出するまで
の間は連続失火と判定する連続失火検出手段とを備える
ことを特徴とする内燃機関用失火検出装置を提供する。In order to achieve the above object, an internal combustion engine misfire detection apparatus according to the present invention outputs a rotation signal at every predetermined rotation angle according to the rotation of the internal combustion engine, as shown in FIG. A rotation signal output means, a measurement value calculation means for obtaining a measurement value determined by measuring a period required for rotation between predetermined rotation angles in the explosion stroke of each cylinder based on the output signal of the rotation signal output means, and the measurement First fluctuation amount calculation means for calculating a first fluctuation amount by obtaining a deviation of an actual measurement value between two cylinders in which the explosion strokes are continuous based on a calculation result of the value calculation means, and the rotation signal output. Before the integral multiple rotation of 360 degrees at the crank angle of the internal combustion engine and the first variation amount of this time calculated by the first variation amount calculation means based on the information from the means and the actual value calculation means. Played in Second variation amount calculating means for calculating a second variation amount by obtaining a deviation from the determined first variation amount; and the second variation amount calculation means based on the first variation amount and the second variation amount. Misfire detection means for detecting misfire of the internal combustion engine, and after detecting the misfire state by the misfire detection means,
Based on the first amount of variation and the second amount of variation, a normal return detection unit that detects a return of the internal combustion engine from a misfire state to a normal combustion state, and a misfire state is detected by the misfire detection unit. And a continuous misfire detecting means for determining continuous misfire until the normal recovery detecting means detects that the internal combustion engine has returned to a normal combustion state. I will provide a.
【０００８】[0008]
【作用】本発明によれば、実測値演算手段において各気
筒の爆発行程における所定回転角度間の実測値を設定す
る。そして、第１の変動量演算手段において上記爆発行
程が連続する２つの気筒間の実測値の偏差を求めること
により第１の変動量を演算し、また、第２の変動量演算
手段において上記第１の変動量演算手段で演算した今回
の第１の変動量と、内燃機関のクランク角３６０度の整
数倍回転前に演算された第１の変動量との偏差を求める
ことにより第２の変動量を演算する。この第１の変動量
と第２の変動量とに基づいて失火検出手段は内燃機関の
失火を検出する。According to the present invention, the actual measurement value calculating means sets the actual measurement value between the predetermined rotation angles in the explosion stroke of each cylinder. Then, the first variation amount calculating means calculates the first variation amount by obtaining the deviation of the measured value between the two cylinders in which the explosion strokes are continuous, and the second variation amount calculating means calculates the first variation amount. The second variation is obtained by obtaining the deviation between the first variation calculated this time by the first variation calculation means and the first variation calculated before the integral multiple rotation of the crank angle of 360 degrees of the internal combustion engine. Calculate the quantity. The misfire detection means detects misfire of the internal combustion engine based on the first variation amount and the second variation amount.
【０００９】さらに、正常復帰検出手段は、前記第１の
変動量と前記第２の変動量とに基づいて内燃機関の失火
状態から正常燃焼状態への復帰を検出する。そして、連
続失火検出手段は、前記失火検出手段により失火を検出
してから、前記正常復帰検出手段により前記内燃機関が
正常燃焼状態に復帰したことを検出するまでの間は連続
失火していると判定する。Further, the normal return detection means detects the return of the internal combustion engine from the misfire state to the normal combustion state based on the first variation amount and the second variation amount. Then, the continuous misfire detection means that there is continuous misfire until it detects that the internal combustion engine has returned to the normal combustion state by the normal recovery detection means after detecting the misfire by the misfire detection means. judge.
【００１０】[0010]
【実施例】以下、本発明を図に示す実施例に基づいて説
明する。図２は本発明の一実施例における装置の構成図
である。図２において、１は６つの気筒からなり直列に
配設された内燃機関（直列６気筒内燃機関）であり、２
は図示しないエアクリーナから導入された吸入空気を内
燃機関１内に導く吸気管である。３は吸気管２内の圧力
を検出する吸気管圧力センサであり、吸気管圧力センサ
３の検出信号は後述する電子制御装置９に入力される。The present invention will be described below based on the embodiments shown in the drawings. FIG. 2 is a block diagram of an apparatus according to an embodiment of the present invention. In FIG. 2, reference numeral 1 denotes an internal combustion engine (in-line 6-cylinder internal combustion engine) which is composed of 6 cylinders and is arranged in series.
Is an intake pipe that guides intake air introduced from an air cleaner (not shown) into the internal combustion engine 1. Reference numeral 3 is an intake pipe pressure sensor for detecting the pressure in the intake pipe 2, and a detection signal of the intake pipe pressure sensor 3 is input to an electronic control unit 9 described later.
【００１１】５は内燃機関１の図示しないクランク軸に
配設され、所定クランク角毎に信号を出力して、内燃機
関１の回転速度Ｎｅ（以下、機関回転数という）を求め
るための回転角センサ（回転信号出力手段）であり、６
は同じくディストリビュータ７に内蔵され、気筒を判別
するための信号を出力する、詳しくは、例えば第１気筒
のピストン１３が最も上にきた時点毎（上死点：♯１Ｔ
ＤＣ）に信号を出力する基準位置センサである。なお、
回転角センサ５、基準位置センサ６からの検出信号も後
述する電子制御装置９に入力される。Reference numeral 5 denotes a rotation angle for arranging a crankshaft (not shown) of the internal combustion engine 1 and outputting a signal at every predetermined crank angle to obtain a rotation speed Ne (hereinafter, referred to as engine rotation speed) of the internal combustion engine 1. A sensor (rotation signal output means), 6
Is also built in the distributor 7 and outputs a signal for discriminating the cylinder. Specifically, for example, at each time when the piston 13 of the first cylinder reaches the highest position (top dead center: # 1T
It is a reference position sensor that outputs a signal to DC). In addition,
Detection signals from the rotation angle sensor 5 and the reference position sensor 6 are also input to the electronic control unit 9 described later.
【００１２】８は内燃機関１の冷却水路に配設され、冷
却水の温度を検出する水温センサであり、水温センサ８
からの検出信号も後述する電子制御装置９に入力され
る。９は上記各センサおよび図示しないセンサからの検
出信号に基づいて燃料系および点火系の最適な制御量を
演算し、インジェクタ１０およびイグナイタ１１等を的
確に制御するための制御信号を出力する公知の電子制御
装置（以下、ＥＣＵという）である。Reference numeral 8 denotes a water temperature sensor which is arranged in the cooling water passage of the internal combustion engine 1 and detects the temperature of the cooling water.
The detection signal from is also input to the electronic control unit 9 described later. Reference numeral 9 is a well-known device that calculates optimum control amounts of the fuel system and the ignition system based on detection signals from the above-mentioned sensors and a sensor (not shown), and outputs a control signal for accurately controlling the injector 10, the igniter 11 and the like. It is an electronic control unit (hereinafter referred to as ECU).
【００１３】また、ＥＣＵ９は演算処理を行う公知のＣ
ＰＵ９ａ、制御プログラムおよび演算に必要な制御定数
を記憶しておくための読み出し専用のＲＯＭ９ｂ、上記
ＣＰＵ９ａ動作中に演算データを一時記憶するためのＲ
ＡＭ９ｃ、およびＥＣＵ９外部からの信号を入出力する
ためのＩ／Ｏポート９ｄにより構成されている。さら
に、ＥＣＵ９は第１の変動量演算手段，第２の変動量演
算手段，失火検出手段，正常復帰検出手段，連続失火検
出手段をなし、回転角センサ５からの検出信号に基づ
き、後述する手法を用いて第１，第２の変動量を演算
し、この第１，第２の変動量に基づいて内燃機関１の失
火，正常復帰，連続失火を検出する。Further, the ECU 9 is a well-known C for performing arithmetic processing.
PU 9a, read-only ROM 9b for storing control programs and control constants necessary for calculation, R for temporarily storing calculation data while the CPU 9a is operating.
It is composed of an AM 9c and an I / O port 9d for inputting / outputting a signal from outside the ECU 9. Further, the ECU 9 constitutes a first variation amount calculation means, a second variation amount calculation means, a misfire detection means, a normal recovery detection means, a continuous misfire detection means, and a method described later based on a detection signal from the rotation angle sensor 5. Is used to calculate the first and second fluctuation amounts, and based on the first and second fluctuation amounts, misfire, normal recovery, and continuous misfire of the internal combustion engine 1 are detected.
【００１４】１２はＥＣＵ９において失火発生と判断さ
れたときに、失火発生を運転者等に知らせるための警告
ランプである。次に、ＥＣＵ９内で実行される失火検出
処理について図３に示すフローチャートを用いて説明す
る。なお、図３のルーチンは所定クランク角毎（本実施
例では３０℃Ａ毎）に割り込み処理される。Reference numeral 12 is a warning lamp for notifying the driver of the occurrence of misfire when the ECU 9 determines that misfire has occurred. Next, the misfire detection process executed in the ECU 9 will be described with reference to the flowchart shown in FIG. The routine of FIG. 3 is interrupted at every predetermined crank angle (every 30 ° C. in this embodiment).
【００１５】ステップ１００では前回の割り込み時刻と
今回の割り込み時刻との偏差から３０℃Ａ回転するのに
要した時間Ｔ３０ｉを算出する。ステップ１１０では今
回の割り込みタイミングが上死点（ＴＤＣ）であるか否
かを判別し、上死点でないならステップ１２０におい
て、ステップ１３０で１２０°ＣＡ回転するのに要する
時間を算出するための前段階として、Ｔ３０i をＴ３０
i-1 、Ｔ３０i-1 をＴ３０i-2 、Ｔ３０i-2 をＴ３０
i-3 として本ルーチンを終了する。一方、今回の割り込
みタイミングが上死点であるならステップ１３０に進
む。In step 100, the time T30i required to rotate 30 ° C. A is calculated from the deviation between the previous interrupt time and the current interrupt time. In step 110, it is judged whether or not the interrupt timing at this time is the top dead center (TDC), and if it is not the top dead center, in step 120, before calculating the time required for 120 ° CA rotation in step 130 As a step, T30 i is changed to T30
i-1 , T30 i-1 to T30 i-2 , T30 i-2 to T30
This routine ends as i-3 . On the other hand, if the interrupt timing this time is the top dead center, the process proceeds to step 130.
【００１６】ステップ１３０ではステップ１００におい
て算出した３０℃Ａ回転するのに要する時間Ｔ３０
i と、前回、前々回、および３回前の実行時にそれぞれ
求めたＴ３０i-1 、Ｔ３０i-2 、およびＴ３０i-3 の全
４回分のデータを累計して、１２０°ＣＡ回転するのに
要する時間Ｔ１２０n を算出する。ステップ１４０では
クランク角１２０°ＣＡ間の平均回転数ωn を算出す
る。詳しくは、ステップ１３０で求めた時間Ｔ１２０n
の逆数を求め、平均回転数ω n とする。In step 130, the
Calculated time T30 required to rotate 30 ° C A
iAnd the last time, the time before the last time, and the third time before
Sought T30i-1, T30i-2, And T30i-3All of
Cumulative data of 4 times, for 120 ° CA rotation
Time required T120nTo calculate. In step 140
Crank angle 120 ° Average rotation speed ω during CAnCalculate
It Specifically, the time T120 obtained in step 130n
Calculate the reciprocal of nAnd
【００１７】ステップ１５０では次式（数式１）に基づ
いて平均回転数変化量Δωn を算出する。In step 150, the average rotational speed change amount Δω n is calculated based on the following equation (equation 1).
【００１８】[0018]
【数１】 Δωn ＝（ωn-1 −ωn ）−（ωn-4 −ωn-3 ） なお、ωn はステップ１４０で算出した今回の平均回転
数であり、ωn-1 は前回の平均回転数である。そして、
（ωn-1 −ωn ）は爆発行程が連続する気筒の変動量
（第１の変動量）である。また、ωn-3 は３回前の平均
回転数であり、ω n-4 は４回前の平均回転数である。そ
して、（ωn-4 −ωn-3 ）はクランク角３６０℃Ａ前に
おける爆発行程が連続する気筒の変動量（第２の変動
量）である。[Formula 1] Δωn= (Ωn-1−ωn)-(Ωn-4−ωn-3) Note that ωnIs the current average rotation calculated in step 140
Is a number, ωn-1Is the previous average rotation speed. And
(Ωn-1−ωn) Is the amount of fluctuation in the cylinder where the explosion stroke is continuous
(First fluctuation amount). Also, ωn-3Is the average three times before
Is the number of revolutions and ω n-4Is the average number of revolutions 4 times before. So
And then (ωn-4−ωn-3) Is before the crank angle of 360 ° A
The amount of fluctuation in the cylinder in which the explosion stroke continues (second fluctuation
Amount).
【００１９】また、ここでは上記第１の変動量と第２の
変動量を同じルーチンの処理で求めたが、第２の変動量
を予め別のルーチンで求めてＥＣＵ９内のＲＡＭ９ｃに
格納し、このルーチンの実行時に第２の変動量をＲＡＭ
９ｃから読み込むというようにしてもよい。ステップ１
６０ではステップ１５０で算出した平均回転数変化量Δ
ωn と失火判定値Ｃ１とを比較し、平均回転数変化量Δ
ωn が失火判定値Ｃ１より大きいときには失火と判断し
てステップ１７０に進み、失火が発生したことを示す失
火検出フラグＸＭＦをセットし、さらに、ステップ１８
０で仮連続失火検出フラグＸＭＦＴn をセットしてステ
ップ２５０に進む。Although the first variation amount and the second variation amount are obtained in the same routine process here, the second variation amount is obtained in advance in another routine and stored in the RAM 9c in the ECU 9, The second fluctuation amount is stored in the RAM when this routine is executed.
You may make it read from 9c. Step 1
At 60, the average rotational speed change amount Δ calculated at step 150
ω n is compared with the misfire determination value C1, and the average rotational speed change amount Δ
When ω n is larger than the misfire determination value C1, it is determined that a misfire has occurred and the routine proceeds to step 170, where a misfire detection flag XMF indicating that a misfire has occurred is set, and then step 18
At 0, the temporary continuous misfire detection flag XMFT n is set, and the routine proceeds to step 250.
【００２０】一方、平均回転数変化量Δωn が失火判定
値Ｃ１より大きくないときはステップ１９０にて、３点
火前に失火判定が行われたかを判定し、失火判定が行わ
れていたときにはステップ２００に進む。３点火前に失
火がない場合は失火なしと判断してステップ２４０に進
む。ステップ２４０では、失火判定フラグＸＭＦをリセ
ットし、ステップ２５０に進む。On the other hand, when the average rotational speed change amount Δω n is not larger than the misfire determination value C1, it is determined in step 190 whether or not the misfire determination is made 3 ignitions before. If the misfire determination is made, the step is performed. Proceed to 200. 3 If there is no misfire before ignition, it is determined that there is no misfire and the routine proceeds to step 240. In step 240, the misfire determination flag XMF is reset, and the process proceeds to step 250.
【００２１】ステップ２００は内燃機関が正常復帰した
かを判定するものである。平均回転数変化量Δωn の計
算式を見れば分かるように、３点火前が正常で今回失火
した場合はΔωn は失火判定値Ｃ１より大きくなる。逆
に３点火前が失火しており、今回正常復帰した場合はΔ
ωn は失火判定値Ｃ１より非常に小さく、通常負の値に
なる。これに着目し失火判定値Ｃ１とは別にＣ２を設定
する。Step 200 is to determine whether the internal combustion engine has returned to normal. As can be seen from formula for average speed change amount Δω n, Δω n is greater than the misfire judgment value C1 when the 3 pre-firing is a misfire this normal. Conversely, if there is a misfire before 3 ignitions and this time the normal return occurs, Δ
ω n is much smaller than the misfire determination value C1 and is usually a negative value. Paying attention to this, C2 is set separately from the misfire determination value C1.
【００２２】平均回転数変化量Δωn が正常判定値Ｃ２
より小さい場合は正常復帰と判定し、ステップ２２０に
て連続失火判定フラグＸＭＦＳをリセットし、さらにス
テップ２３０にて仮連続失火検出フラグＸＭＦＴn をリ
セットする。平均回転数変化量Δωn が正常判定値Ｃ２
より大きい場合は連続失火中と判定し、ステップ２１０
にて連続失火判定フラグＸＭＦＳをセットし、ステップ
２５０に進む。The average rotation speed change amount Δω n is the normal judgment value C2.
If it is smaller, it is determined that the normal recovery has occurred, the continuous misfire determination flag XMFS is reset in step 220, and the provisional continuous misfire detection flag XMFT n is reset in step 230. The average rotation speed change amount Δω n is the normal determination value C2.
If it is larger than the above, it is determined that continuous misfires have occurred, and step 210
Then, the continuous misfire determination flag XMFS is set, and the routine proceeds to step 250.
【００２３】ステップ２５０では次回の判定に備えるた
めに、今回の平均回転数ωn を前回の平均回転数ωn-1
とし、前回の平均回転数ωn-1 を前々回の平均回転数ω
n-2とし、前々回の平均回転数ωn-2 を３回前の平均回
転数ωn-3 とし、３回前の平均回転数ωn-3 を４回前の
平均回転数ωn-4 としてＥＣＵ９内のＲＡＭ９ｃに格納
する。In step 250, in order to prepare for the next determination, the current average rotation speed ω n is changed to the previous average rotation speed ω n-1.
And the previous average rotation speed ω n-1 is the average rotation speed ω of the previous two times.
and n-2, the average rotational speed omega n-3 before 3 times the mean rotational speed omega n-2 before last, the average rotational speed of three times before omega n-3 to 4 times before the average rotational speed omega n- It is stored as 4 in the RAM 9c in the ECU 9.
【００２４】ステップ２６０では次回の判定に備えるた
めに、今回の仮連続失火検出フラグＸＭＦＴn を前回の
仮連続失火検出フラグＸＭＦＴn-1 とし、前回の仮連続
失火検出フラグＸＭＦＴn-1 を前々回の仮連続失火検出
フラグＸＭＦＴn-2 とし、前々回の仮連続失火検出フラ
グＸＭＦＴn-2 を３回前の仮連続失火検出フラグＸＭＦ
Ｔn-3 としてＥＣＵ９内のＲＡＭ９ｃに格納し、メイン
ルーチンにリターンする。In step 260, the provisional continuous misfire detection flag XMFT n for this time is set to the provisional continuous misfire detection flag XMFT n-1 for the previous time, and the provisional continuous misfire detection flag XMFT n-1 for the previous time is set two times before in order to prepare for the next determination. Of the temporary continuous misfire detection flag XMFT n-2, and the temporary continuous misfire detection flag XMFT n-2 of the previous two times is set to the temporary continuous misfire detection flag XMF of the third previous time.
It is stored in the RAM 9c in the ECU 9 as T n-3 , and the process returns to the main routine.
【００２５】図４はダイアグ処理を実行するためのダイ
アグ処理ルーチンであり、所定時間毎に実行される。ス
テップ３００では例えばアクチュエータが正常に作動し
ているか等の各センサからの情報を記憶したダイアグ検
出フラグや、図３で示した処理によって失火発生と判断
された際にセットされる失火検出フラグＸＭＦや連続失
火判定フラグＸＭＦＳを読み込む。FIG. 4 shows a diagnosis processing routine for executing the diagnosis processing, which is executed every predetermined time. In step 300, for example, a diagnostic detection flag that stores information from each sensor such as whether the actuator is operating normally, a misfire detection flag XMF that is set when misfire is determined by the processing shown in FIG. The continuous misfire determination flag XMFS is read.
【００２６】ステップ３１０では、ステップ３００で読
み込んだダイアグ検出フラグの有無を判別し、例えば失
火検出フラグＸＦＭや連続失火判定フラグＸＭＦＳがセ
ットされているならステップ３２０に進み、セットされ
ていないならメインルーチンにリターンする。ステップ
３２０では例えば運転者等に失火が発生したことを知ら
せるための警告ランプ１２を点灯させるなどの周知のフ
ェイルセーフ処理を実行する。In step 310, it is judged whether or not the diagnosis detection flag read in step 300 is present. For example, if the misfire detection flag XFM or the continuous misfire determination flag XMFS is set, the process proceeds to step 320, and if not set, the main routine. Return to. In step 320, a well-known fail-safe process such as turning on the warning lamp 12 for informing the driver of the occurrence of misfire is executed.
【００２７】図５は直列６気筒内燃機関における平均回
転数ωn の変動特性を示し、特に第６気筒と第１気筒と
が１回失火したときの特性である。なお、図５は各気筒
の燃焼行程における平均回転数ωn をそれぞれその気筒
の上死点（ＴＤＣ）位置にプロットしたものである。ま
た、図６は図５における各気筒の平均回転数変化量Δω
n を各気筒の上死点位置にプロットしたものである。な
お、Ｃ１，Ｃ２はそれぞれ失火判定値と正常判定値とを
示している。この図からも分かるように、一度失火がお
こると回転数はすぐには復帰せず、徐々に回復する。FIG. 5 shows the variation characteristic of the average rotational speed ω n in the in-line 6-cylinder internal combustion engine, and particularly the characteristic when the sixth cylinder and the first cylinder misfire once. Note that FIG. 5 is a plot of the average rotational speed ω n in the combustion stroke of each cylinder at the top dead center (TDC) position of that cylinder. Further, FIG. 6 shows the average rotation speed change amount Δω of each cylinder in FIG.
n is plotted at the top dead center position of each cylinder. It should be noted that C1 and C2 indicate a misfire determination value and a normality determination value, respectively. As can be seen from this figure, once misfire occurs, the rotation speed does not immediately return, but gradually recovers.
【００２８】従来技術においては、図５のように、第６
気筒と第１気筒とが失火していると、３６０°ＣＡ前に
おける平均回転数ωn の変動量（第２の変動量（ωn-4
−ω n-3 ））と今回の平均回転数ωn の変動量（第１の
変動量（ωn-1 −ωn ））との偏差（平均回転数変化量
Δωn ）に差がない（Δωn ＜Ｃ１）ので失火判定がで
きない（図６のＡ点）。In the prior art, as shown in FIG.
If the cylinder and the first cylinder are misfiring, before 360 ° CA
Average rotation speed ωnFluctuation amount (second fluctuation amount (ωn-4
−ω n-3)) And the current average speed ωnFluctuation amount (first
Variation (ωn-1−ωn)) (Average rotation speed change amount)
Δωn) There is no difference (ΔωnSince <C1), misfire can be judged.
I can't (point A in Figure 6).
【００２９】本発明においては、図５のように、第６気
筒が正常復帰した場合には正常復帰判定手段（平均回転
数変化量Δωn ＜Ｃ２）により正常復帰を検出して、そ
の間は３６０°ＣＡ毎に連続失火していると判定できる
ので、図６に示したように正確に失火判別することがで
きることがわかる。本実施例において、回転角センサ
５，基準位置センサ６が回転信号出力手段に、ステップ
１００，ステップ１２０，ステップ１３０，ステップ１
４０が実測値演算手段に、ステップ１５０で演算される
数式の前２項が第１の変動量演算手段に、ステップ１５
０が第２の変動量演算手段に、ステップ１６０，ステッ
プ１７０が失火検出手段に、ステップ２００，ステップ
２２０，ステップ２３０が正常復帰検出手段に、ステッ
プ２１０が連続失火検出手段にそれぞれ相当し、機能す
る。In the present invention, as shown in FIG. 5, when the sixth cylinder returns to normal, the normal return determination means (average rotation speed change amount Δω n <C2) detects normal return, and during that period 360 Since it can be determined that continuous misfires have occurred for each CA, it can be seen that misfires can be accurately determined as shown in FIG. In the present embodiment, the rotation angle sensor 5 and the reference position sensor 6 serve as rotation signal output means in steps 100, 120, 130 and 1, respectively.
40 is the measured value calculation means, the previous two terms of the mathematical formula calculated in step 150 are the first fluctuation amount calculation means, and step 15
0 corresponds to the second fluctuation amount calculating means, steps 160 and 170 correspond to misfire detecting means, steps 200, 220 and 230 correspond to normal recovery detecting means, and step 210 corresponds to continuous misfire detecting means. To do.
【００３０】なお、本実施例では６気筒内燃機関につい
て、本発明を採用した場合について説明したが、もちろ
ん他の気筒数の内燃機関に本発明を採用してもよく、例
えば、４気筒内燃機関では第１の変動量（ωn-1 −
ωn ）より３６０°ＣＡ前の平均回転数の変動量として
第２の変動量が（ωn-3 −ωn-2 ）として設定される。
また、本実施例では第１の変動量より３６０°ＣＡ前の
平均回転数の変動量として第２の変動量を設定したが、
内燃機関２回転（７２０°ＣＡ）前の平均回転数の変動
量として第２の変動量を設定しても同様である。この場
合、第１の変動量（ωn-1 −ωn ）より７２０°ＣＡ前
の平均回転数の変動量として第２の変動量が（ωn-7 −
ωn-6 ）として設定され、単一気筒の連続失火判定が行
われる。他にも、第１の変動量より１０８０°ＣＡ，１
４４０°ＣＡ前等、３６０°ＣＡの整数倍の内燃機関回
転前の第１の変動量との偏差より第２の変動量を求めて
もよい。In the present embodiment, the case where the present invention is applied to the 6-cylinder internal combustion engine has been described, but it goes without saying that the present invention may be applied to an internal combustion engine having another number of cylinders, for example, a 4-cylinder internal combustion engine. Then, the first variation (ω n-1 −
A second fluctuation amount is set as (ω n−3 −ω n−2 ) as a fluctuation amount of the average rotational speed 360 ° CA before ω n ).
Further, in the present embodiment, the second variation amount is set as the variation amount of the average rotation speed 360 ° CA before the first variation amount,
The same applies when the second variation amount is set as the variation amount of the average rotational speed before two revolutions of the internal combustion engine (720 ° CA). In this case, the second variation amount is (ω n-7 −) as the variation amount of the average rotational speed 720 ° CA before the first variation amount (ω n-1 −ω n ).
ω n-6 ) is set, and continuous misfire determination for a single cylinder is performed. In addition, the first fluctuation amount is 1080 ° CA, 1
The second variation amount may be obtained from the deviation from the first variation amount before the rotation of the internal combustion engine, which is an integral multiple of 360 ° CA, such as before 440 ° CA.
【００３１】また、本実施例では連続失火を最初の失火
から正常復帰するまでの間として判定しているが、最初
の失火から復帰するまでのあいだ、特定気筒の平均回転
数とその他の気筒の平均回転数とを比較し、所定値以上
差がある場合のみ連続失火と判定することにより精度を
上げることも可能である。また、本実施例では所定回転
角（３０°ＣＡ）回転するのに要した時間Ｔ３０ i を求
め、この値から平均回転数ωn を算出して平均回転数ω
n から第１の変動量および第２の変動量を求めたが、所
定回転角回転するのに要した時間Ｔ３０iから直接第１
の変動量および第２の変動量を求めてもよい。In this embodiment, continuous misfire is the first misfire.
It is judged as from the time until the normal recovery, but at the beginning
Average rotation of a specific cylinder between the misfire and recovery
Number and the average number of revolutions of other cylinders are compared, and more than a predetermined value
Accuracy is judged by determining continuous misfires only when there is a difference
It is possible to raise it. Also, in this embodiment, a predetermined rotation
Time T30 required to rotate an angle (30 ° CA) iSeeking
Therefore, from this value the average speed ωnTo calculate the average speed ω
nThe first variation and the second variation were calculated from
Time required to rotate at constant rotation angle T30iDirect from first
And the second variation amount may be obtained.
【００３２】[0032]
【発明の効果】以上述べたように本発明においては、各
気筒の爆発行程における所定回転角度間の実測値を設定
する。そして、第１の変動量設定手段において上記爆発
行程が連続する２つの気筒間の実測値の偏差を求めるこ
とにより第１の変動量を設定し、また、第２の変動量設
定手段において上記第１の変動量設定手段演算された今
回の第１の変動量と、内燃機関のクランク角３６０度の
整数倍回転前に演算された第１の変動量との偏差を求め
ることにより第２の変動量を設定する。As described above, in the present invention, the actual measurement value between the predetermined rotation angles in the explosion stroke of each cylinder is set. Then, the first fluctuation amount setting means sets the first fluctuation amount by obtaining the deviation of the actual measurement value between the two cylinders in which the explosion strokes are continuous, and the second fluctuation amount setting means sets the first fluctuation amount. The second variation is obtained by obtaining a deviation between the first variation calculated this time by the first variation amount setting means and the first variation calculated before the integral multiple rotation of the crank angle of 360 degrees of the internal combustion engine. Set the amount.
【００３３】この第１の変動量と第２の変動量とに基づ
いて内燃機関の失火状態を検出するとともに、正常復帰
検出手段により前記第１の変化量と第２の変化量とに基
づいて前記内燃機関の失火状態から正常燃焼状態への復
帰を検出し、連続失火検出手段から前記失火検出手段に
より失火状態を検出してから、前記正常復帰検出手段に
より内燃機関が正常燃焼状態に復帰したことを検出する
までの間は連続失火と判定することにより、特定気筒の
連続失火を精度よく検出することができるという優れた
効果を奏する。The misfire state of the internal combustion engine is detected based on the first variation amount and the second variation amount, and the normal recovery detecting means detects the misfire state based on the first variation amount and the second variation amount. Detecting the return of the internal combustion engine from the misfire state to the normal combustion state, detecting the misfire state from the continuous misfire detection means by the misfire detection means, and then returning the internal combustion engine to the normal combustion state by the normal return detection means. By determining continuous misfire until that is detected, there is an excellent effect that continuous misfire in a specific cylinder can be detected with high accuracy.
【図１】本発明のクレーム対応図である。FIG. 1 is a diagram corresponding to a claim of the present invention.
【図２】本発明を用いた実施例の装置の構成を示す全体
構成図である。FIG. 2 is an overall configuration diagram showing a configuration of an apparatus of an embodiment using the present invention.
【図３】本実施例の失火検出作動の説明に供するフロー
チャートである。FIG. 3 is a flow chart for explaining a misfire detection operation of the present embodiment.
【図４】本実施例の失火検出作動の説明に供するフロー
チャートである。FIG. 4 is a flow chart for explaining a misfire detection operation of the present embodiment.
【図５】本実施例の第６気筒と第１気筒とがそれぞれ１
回失火したときの内燃機関の平均回転数ωn の特性を示
す図である。FIG. 5 shows that each of the sixth cylinder and the first cylinder of the present embodiment has one
It is a figure showing the characteristic of the average number of rotations ω n of an internal-combustion engine at the time of misfire.
【図６】本実施例の第６気筒と第１気筒とがそれぞれ１
回失火したときの内燃機関の平均回転数変化量Δωn の
特性を示す図である。FIG. 6 shows that each of the sixth cylinder and the first cylinder of the present embodiment is 1
FIG. 5 is a diagram showing characteristics of an average rotation speed change amount Δω n of an internal combustion engine when a misfire occurs.
５ 回転角センサ ６ 基準位置センサ ９ 電子制御装置（ＥＣＵ） 5 Rotation angle sensor 6 Reference position sensor 9 Electronic control unit (ECU)
Claims (4)
毎に回転信号を出力する回転信号出力手段と、 前記回転信号出力手段の出力信号に基づき各気筒の爆発
行程における所定回転角度間の回転に要した期間を計測
することにより定まる実測値を求める実測値演算手段
と、 前記実測値演算手段の演算結果に基づいて、前記爆発行
程が連続する２つの気筒間の実測値の偏差を求めること
により第１の変動量を演算する第１の変動量演算手段
と、 前記回転信号出力手段および前記実測値演算手段からの
情報に基づいて、前記第１の変動量演算手段で演算され
た今回の前記第１の変動量と、前記内燃機関のクランク
角で３６０度の整数倍回転前に演算された前記第１の変
動量との偏差を求めることにより第２の変動量を演算す
る第２の変動量演算手段と、 前記第１の変動量と前記第２の変動量とに基づいて前記
内燃機関の失火を検出する失火検出手段と、 前記失火検出手段により失火状態を検出してから、前記
第１の変動量と前記第２の変動量とに基づいて、前記内
燃機関の失火状態から正常燃焼状態への復帰を検出する
正常復帰検出手段と、 前記失火検出手段により失火状態を検出してから、前記
正常復帰検出手段により前記内燃機関が正常燃焼状態に
復帰したことを検出するまでの間は連続失火と判定する
連続失火検出手段とを備えることを特徴とする内燃機関
用失火検出装置。1. A rotation signal output means for outputting a rotation signal for each predetermined rotation angle in accordance with the rotation of the internal combustion engine, and a predetermined rotation angle in the explosion stroke of each cylinder based on the output signal of the rotation signal output means. An actual measurement value calculating unit that obtains an actual measurement value that is determined by measuring the period required for rotation, and a deviation of the actual measurement value between the two cylinders in which the explosion strokes are continuous, based on the calculation result of the actual measurement value calculation unit. The first fluctuation amount calculation means for calculating the first fluctuation amount by the above, and the current time calculated by the first fluctuation amount calculation means based on the information from the rotation signal output means and the actual measurement value calculation means. A second variation amount is calculated by obtaining a deviation between the first variation amount and the first variation amount calculated before an integral multiple rotation of 360 degrees at the crank angle of the internal combustion engine. Fluctuation calculator A step, a misfire detection means for detecting a misfire of the internal combustion engine based on the first variation amount and the second variation amount, and a first misfire state after detecting a misfire state by the misfire detection means. Based on the variation amount and the second variation amount, a normal return detection means for detecting a return of the internal combustion engine from a misfire state to a normal combustion state; and a misfire state detected by the misfire detection means, A misfire detection device for an internal combustion engine, comprising: continuous misfire detection means for determining a continuous misfire until the normal recovery detection means detects that the internal combustion engine has returned to a normal combustion state.
と前記第２の変動量とを比較する失火比較手段と、この
失火比較手段により比較された結果、前記第１の変動量
が前記第２の変動量より所定値以上大きいときに失火と
判定する失火判定手段とを備え、 前記正常復帰検出手段は、失火が検出された気筒に対す
る前記第１の変動量と前記第２の変動量とを比較する復
帰比較手段と、この復帰比較手段により比較された結
果、前記第１の変動量が前記第２の変動量より所定値以
上小さいときに前記内燃機関が失火状態から正常状態に
復帰したと判定する復帰判定手段とを備えることを特徴
とする請求項１記載の内燃機関用失火検出装置。2. The misfire detecting means compares the first fluctuation amount with the second fluctuation amount and the misfire comparing means compares the first fluctuation amount with the misfire comparing means. A misfire determination unit that determines a misfire when it is larger than the second variation amount by a predetermined value or more is provided, and the normal recovery detection unit includes the first variation amount and the second variation with respect to a cylinder in which misfire is detected. As a result of comparison by the return comparing means for comparing the amount with the return comparing means, when the first variation amount is smaller than the second variation amount by a predetermined value or more, the internal combustion engine changes from a misfire state to a normal state. The misfire detection device for an internal combustion engine according to claim 1, further comprising a return determination means for determining that the engine has returned.
おける平均回転時間を演算するものであることを特徴と
する請求項１または請求項２記載の内燃機関用失火検出
装置。3. The misfire detection device for an internal combustion engine according to claim 1, wherein the measured value calculation means calculates an average rotation time in the explosion stroke.
おける前記内燃機関の機関回転数を演算するものである
ことを特徴とする請求項１または請求項２記載の内燃機
関用失火検出装置。4. The misfire detection device for an internal combustion engine according to claim 1, wherein the measured value calculation means calculates an engine speed of the internal combustion engine in the explosion stroke.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12698693A JPH06336948A (en) | 1993-05-28 | 1993-05-28 | Misfire detecting device for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12698693A JPH06336948A (en) | 1993-05-28 | 1993-05-28 | Misfire detecting device for internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06336948A true JPH06336948A (en) | 1994-12-06 |
Family
ID=14948827
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12698693A Withdrawn JPH06336948A (en) | 1993-05-28 | 1993-05-28 | Misfire detecting device for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06336948A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010084774A (en) * | 2005-01-11 | 2010-04-15 | Toyota Motor Corp | Misfire determining device and misfire determining method for internal combustion engine |
| US8046155B2 (en) | 2009-02-13 | 2011-10-25 | Denso Corporation | Method and apparatus for misfire detection using engine cycles at least subsequent to actual misfire event |
| US8290688B2 (en) | 2009-09-01 | 2012-10-16 | Denso Corporation | Exhaust gas oxygen sensor diagnostic method and apparatus |
| US20160222893A1 (en) * | 2015-02-02 | 2016-08-04 | Fuji Jukogyo Kabushiki Kaisha | Misfire detection device |
-
1993
- 1993-05-28 JP JP12698693A patent/JPH06336948A/en not_active Withdrawn
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010084774A (en) * | 2005-01-11 | 2010-04-15 | Toyota Motor Corp | Misfire determining device and misfire determining method for internal combustion engine |
| JP2010084773A (en) * | 2005-01-11 | 2010-04-15 | Toyota Motor Corp | Misfire determining device for internal combustion engine and misfire determining method |
| US8046155B2 (en) | 2009-02-13 | 2011-10-25 | Denso Corporation | Method and apparatus for misfire detection using engine cycles at least subsequent to actual misfire event |
| US8290688B2 (en) | 2009-09-01 | 2012-10-16 | Denso Corporation | Exhaust gas oxygen sensor diagnostic method and apparatus |
| US20160222893A1 (en) * | 2015-02-02 | 2016-08-04 | Fuji Jukogyo Kabushiki Kaisha | Misfire detection device |
| JP2016142181A (en) * | 2015-02-02 | 2016-08-08 | 富士重工業株式会社 | Misfire determination device |
| US10221825B2 (en) | 2015-02-02 | 2019-03-05 | Subaru Corporation | Misfire detection device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000801 |