JPH0255616B2 - - Google Patents
Info
- Publication number
- JPH0255616B2 JPH0255616B2 JP59181447A JP18144784A JPH0255616B2 JP H0255616 B2 JPH0255616 B2 JP H0255616B2 JP 59181447 A JP59181447 A JP 59181447A JP 18144784 A JP18144784 A JP 18144784A JP H0255616 B2 JPH0255616 B2 JP H0255616B2
- Authority
- JP
- Japan
- Prior art keywords
- intake air
- air amount
- injection amount
- engine
- 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.)
- Expired - Lifetime
Links
- 238000002347 injection Methods 0.000 claims description 97
- 239000007924 injection Substances 0.000 claims description 97
- 239000000446 fuel Substances 0.000 claims description 36
- 230000002159 abnormal effect Effects 0.000 claims description 16
- 238000002485 combustion reaction Methods 0.000 claims description 8
- 230000005856 abnormality Effects 0.000 description 18
- 238000012937 correction Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 230000003197 catalytic effect Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 206010039203 Road traffic accident Diseases 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/22—Safety or indicating devices for abnormal conditions
- F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/24—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means
- F02D41/26—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor
- F02D41/266—Electrical control of supply of combustible mixture or its constituents characterised by the use of digital means using computer, e.g. microprocessor the computer being backed-up or assisted by another circuit, e.g. analogue
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/22—Safety or indicating devices for abnormal conditions
- F02D2041/227—Limping Home, i.e. taking specific engine control measures at abnormal conditions
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Description
【発明の詳細な説明】
（技術分野）
本発明は、内燃機関の燃料噴射制御装置に関す
る。DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a fuel injection control device for an internal combustion engine.
（従来技術）
従来の内燃機関の燃料噴射制御装置としては、
例えば特開昭55−49546号公報に記載されたもの
が知られており、第８図のように示される。第８
図において、１は機関本体を示し、この機関本体
１に連通する吸気通路２には上流側からエアフロ
ーメータ３および絞り弁４が順次配設されてい
る。エアフローメータ３は機関の本体１に吸入さ
れる吸入空気量に対応する吸気量信号をコントロ
ールユニツト５に出力している。６はクランク角
センサであり、クランク角センサ６はクランクシ
ヤフト７の角速度、例えばクランク角の2゜信号を
検出し機関の回転数に比例した回転数信号をコン
トロールユニツト５に出力している。コントロー
ルユニツト５は吸気量信号と回転数信号に基づい
て当該吸気量に最適の基本噴射量を演算した後、
この基本噴射量を機関の運転状態に対応するよう
各種増量補正（例えば、水温補正、アイドル後補
正等）して最終噴射量を決定し、最終噴射量信号
を吸気通路２に設けられた燃料噴射ノズル８に出
力する。燃料噴射ノズル８は最終噴射量信号が入
力されると、燃料ポンプ９による加圧燃料を最終
噴射量だけ噴射する。(Prior art) As a conventional fuel injection control device for an internal combustion engine,
For example, the one described in Japanese Unexamined Patent Publication No. 55-49546 is known, and is shown in FIG. 8th
In the figure, reference numeral 1 indicates an engine body, and an air flow meter 3 and a throttle valve 4 are sequentially disposed in an intake passage 2 communicating with the engine body 1 from the upstream side. The air flow meter 3 outputs an intake air amount signal corresponding to the amount of intake air taken into the main body 1 of the engine to the control unit 5. A crank angle sensor 6 detects the angular velocity of the crankshaft 7, for example, a 2° signal of the crank angle, and outputs a rotation speed signal proportional to the engine rotation speed to the control unit 5. The control unit 5 calculates the optimum basic injection amount for the intake air amount based on the intake air amount signal and the rotation speed signal, and then
The final injection amount is determined by making various increase corrections (for example, water temperature correction, post-idle correction, etc.) to correspond to the operating state of the engine, and the final injection amount signal is sent to the fuel injection valve installed in the intake passage 2. Output to nozzle 8. When the final injection amount signal is input to the fuel injection nozzle 8, the fuel injection nozzle 8 injects pressurized fuel by the fuel pump 9 by the final injection amount.
しかしながら、このような従来の内燃機関の燃
料噴射制御装置にあつては、エアフローメータ３
に異常が生じた（例えば、エアフローメータ３信
号線の断線事故等）場合、最終噴射量をコントロ
ールユニツト５内に予め設定された所定量とする
構成となつていたため、エアフローメータ３異常
時に機関が高速あるいは高負荷運転されていれ
ば、機関に適切な燃料が供給されず、車両の運転
性が悪化するという問題点があつた。 However, in such a conventional fuel injection control device for an internal combustion engine, the air flow meter 3
If an abnormality occurs in the air flow meter 3 (for example, a disconnection accident in the air flow meter 3 signal wire), the final injection amount is set to a predetermined amount in the control unit 5. If the vehicle is operated at high speed or under a high load, the engine is not supplied with adequate fuel, resulting in a problem in which the drivability of the vehicle deteriorates.
すなわち、エアフローメータ３異常時の最終噴
射量は少なくとも機関の停止や再始動不能を回避
できるような燃料量であるため、機関高速時には
空燃比が過濃となり、また高負荷時には希薄とな
る。その結果、理論空燃比から大きくはずれると
排気系に設置されている触媒コンバータが焼損す
る、あるいは機関高速時であれば車両が継続して
高速運転され交通事故を引き起こす等の問題点が
あつた。 That is, the final injection amount when the air flow meter 3 is abnormal is at least the amount of fuel that can avoid stopping the engine or being unable to restart it, so the air-fuel ratio becomes excessively rich when the engine is running at high speed, and becomes lean when the engine is under high load. As a result, if the air-fuel ratio deviates significantly from the stoichiometric air-fuel ratio, the catalytic converter installed in the exhaust system will burn out, or if the engine is running at high speed, the vehicle will continue to be driven at high speed, causing traffic accidents.
そこで、本出願人は、先に出願した特願昭58−
29674号明細書において、吸入空気量と機関回転
数に基づいて吸気量センサの異常を判別し、吸気
量センサが異常のとき、回転数に基づいて基本噴
射量を所定量に設定する燃料噴射制御装置を開示
した。 Therefore, the present applicant filed the earlier patent application filed in 1983-
In the specification of No. 29674, fuel injection control determines whether an intake air amount sensor is abnormal based on the intake air amount and engine speed, and sets the basic injection amount to a predetermined amount based on the engine speed when the intake air amount sensor is abnormal. disclosed the device.
しかしながら、この燃料噴射制御装置にあつて
は、吸入空気量と機関回転数にに基づいて吸気量
センサの異常を判別しており、同一回転数に対応
する吸気量の範囲が広いので、吸気量センサの異
常判別精度を十分向上させることができなかつ
た。また、吸気量センサの異常時に、機関の回転
数のみに基づいて基本噴射量を設定していたの
で、機関の運転状態に最適な噴射量に制御するこ
とが困難で、機関の運転性能を十分向上させるこ
とができなかつた。 However, this fuel injection control device determines whether there is an abnormality in the intake air amount sensor based on the intake air amount and engine speed, and since the range of intake air amount corresponding to the same rotation speed is wide, the intake air amount It was not possible to sufficiently improve the accuracy of sensor abnormality discrimination. In addition, when the intake air amount sensor malfunctions, the basic injection amount is set based only on the engine speed, which makes it difficult to control the injection amount to the optimum amount for the engine operating condition, and this makes it difficult to maintain sufficient engine performance. I couldn't improve it.
（発明の目的）
そこで、本発明は、吸気量と密接な関係を有す
る絞り弁開度に基づいて吸気量センサの異常を判
別し、異常時には、絞り弁開度と機関回転数に基
づいて補助噴射量を演算し、該補助噴射量に基づ
いて最終噴射量を演算することにより、吸気量セ
ンサの異常発生時に異常を直ちに判別するととも
に、異常判別精度を向上させることで、吸気量セ
ンサの異常時においても、機関の運転状態により
一層適切な噴射量を演算して、機関の運転性能を
より一層向上させることを目的としている。(Purpose of the Invention) Therefore, the present invention determines an abnormality in the intake air amount sensor based on the throttle valve opening degree, which has a close relationship with the intake air amount, and provides assistance based on the throttle valve opening degree and engine rotational speed in the event of an abnormality. By calculating the injection amount and calculating the final injection amount based on the auxiliary injection amount, it is possible to immediately identify an abnormality when an abnormality occurs in the intake air amount sensor. The purpose of the present invention is to calculate a more appropriate injection amount depending on the operating state of the engine to further improve the operating performance of the engine.
（発明の構成）
本発明の内燃機関の燃料噴射制御装置は、その
全体構成図を第１図に示すように、機関の吸入空
気量を検出する吸気量センサ１１と、機関の回転
数を検出する回転数センサ１２と、機関の絞り弁
の開度を検出する絞り弁開度センサ１３と、検出
された絞り弁開度に対応して設定され夫々絞り弁
開度が大きくなる程大きい値となるように設定さ
れた吸入空気量の上限値と下限値とを記憶してい
る手段と、検出された絞り弁開度に対応する前記
上限値および下限値と検出された吸入空気量とを
比較し、検出された吸入空気量が上限値より大き
いときおよび下限値より小さいときに吸気量セン
サが異常であると判別する手段と（これら記憶す
る手段および判別する手段は判別手段１６と言
う）、吸気量センサが正常のとき、吸入空気量と
機関回転数に基づいて燃料の基本噴射量を演算す
る基本噴射量演算手段１７と、吸気量センサが異
常のとき、絞り弁開度と機関回転数に基づいて燃
料の補助噴射量を演算する補助噴射量演算手段１
８と、前記基本噴射量または補助噴射量を機関の
運転状態に基づいて補正して最終噴射量を演算す
る最終噴射量演算手段１９と、最終噴射量の燃料
を噴射する噴射手段２５と、を備えたものとする
ことにより、吸気量センサの異常をより一層適確
に判別するとともに、吸気量センサの異常時によ
り一層機関の運転状態に適した燃料量を噴射する
ものである。(Structure of the Invention) The fuel injection control device for an internal combustion engine of the present invention, as shown in the overall configuration diagram in FIG. A rotation speed sensor 12 detects the opening of the throttle valve of the engine, and a throttle valve opening sensor 13 detects the opening of the throttle valve of the engine. A means for storing an upper limit value and a lower limit value of the intake air amount set so that and means for determining that the intake air amount sensor is abnormal when the detected intake air amount is greater than the upper limit value and smaller than the lower limit value (these storing means and the determining means are referred to as determining means 16); When the intake air amount sensor is normal, the basic injection amount calculation means 17 calculates the basic injection amount of fuel based on the intake air amount and the engine speed, and when the intake air amount sensor is abnormal, the basic injection amount calculation means 17 calculates the throttle valve opening and the engine speed. Auxiliary injection amount calculation means 1 that calculates an auxiliary injection amount of fuel based on
8, final injection amount calculation means 19 for calculating the final injection amount by correcting the basic injection amount or auxiliary injection amount based on the operating state of the engine, and injection means 25 for injecting the final injection amount of fuel. By providing this, abnormalities in the intake air amount sensor can be determined more accurately, and when the intake air amount sensor is abnormal, an amount of fuel more suitable for the operating state of the engine can be injected.
（実施例）
以下、本発明の内燃機関の燃料噴射制御装置の
実施例を図面に基づいて説明する。(Example) Hereinafter, an example of the fuel injection control device for an internal combustion engine of the present invention will be described based on the drawings.
第２〜７図は本発明の一実施例を示す図であ
る。 2 to 7 are diagrams showing an embodiment of the present invention.
まず、構成を説明すると、第２図において、１
１は吸気量センサ（例えば、エアフローメータ）
であり、吸気量センサ１１は機関の吸入空気量Ｑ
を検出して吸気量信号を出力する。１２は回転数
センサ（例えば、クランク角センサ）であり、回
転数センサ１２は、例えばクランク角（ピストン
位置）の2゜信号を検出して機関の回転数Ｎに対応
する回転数信号を出力する。１３は絞り弁開度セ
ンサであり、絞り弁開度センサ１３は機関の吸気
通路に設けられた絞り弁の開度θを検出して開度
信号を出力する。１４はコントロールユニツトで
あり、コントロールユニツト１４は入力回路１
５、判別手段１６、基本噴射量演算回路（基本噴
射量演算手段）１７、補助噴射量演算手段１８、
最終噴射量演算回路（最終噴射量演算手段）１９
および出力回路２０により構成されている。前記
吸気量信号および開度信号は入力回路１５に入力
されており、入力回路１５はアナログ信号として
入力される吸気量信号、回転数信号および開度信
号をデイジタル変換して判別手段１６に入力す
る。判別手段１６は判別する手段としての判別回
路２１と記憶する手段としてのメモリ２２により
構成されており、吸入空気量Ｑと絞り弁開度θに
基づいて吸気量センサ１１が正常であるか異常で
あるか（例えば、吸気量センサ１１が信号線の断
線事故等によりその機能が停止しているか否か）
を判別する。すなわち、メモリ２２は、第５図に
示すように検出された絞り弁開度θに対応して設
定され夫々絞り弁開度θが大きくなる程大きい値
となるように設定された吸入空気量Ｑの所定の上
限値Q〓uと下限値Q〓Lとを記憶しており、判別回路
２１はメモリ２２に記憶された前記上限値Q〓uお
よび下限値Q〓Lと検出された吸入空気量Ｑとを比
較し、検出された吸入空気量Ｑが上限値Q〓uより
大きいときおよび下限値Q〓Lより小さいときに吸
気量センサ１１が異常であると判別する。基本噴
射量演算回路１７は、吸気量センサ１１が正常の
とき、吸入空気量Ｑと機関回転数Ｎに基づいて基
本噴射量Tpを次式に従つて演算する。 First, to explain the configuration, in Figure 2, 1
1 is an intake air amount sensor (e.g. air flow meter)
The intake air amount sensor 11 detects the intake air amount Q of the engine.
is detected and outputs an intake air amount signal. 12 is a rotation speed sensor (for example, a crank angle sensor), and the rotation speed sensor 12 detects, for example, a 2° signal of a crank angle (piston position) and outputs a rotation speed signal corresponding to the rotation speed N of the engine. . 13 is a throttle valve opening sensor, and the throttle valve opening sensor 13 detects the opening θ of a throttle valve provided in the intake passage of the engine and outputs an opening signal. 14 is a control unit, and the control unit 14 is the input circuit 1.
5. Discrimination means 16, basic injection amount calculation circuit (basic injection amount calculation means) 17, auxiliary injection amount calculation means 18,
Final injection amount calculation circuit (final injection amount calculation means) 19
and an output circuit 20. The intake air amount signal and the opening degree signal are input to an input circuit 15, and the input circuit 15 converts the intake air amount signal, rotation speed signal, and opening degree signal input as analog signals into digital signals and inputs the converted signals to the determining means 16. . The determining means 16 is composed of a determining circuit 21 as a determining means and a memory 22 as a storing means, and determines whether the intake air amount sensor 11 is normal or abnormal based on the intake air amount Q and the throttle valve opening θ. (For example, whether the function of the intake air amount sensor 11 has stopped due to a signal wire breakage accident, etc.)
Determine. That is, the memory 22 stores the intake air amount Q, which is set in correspondence with the detected throttle valve opening θ, as shown in FIG. A predetermined upper limit value Q〓 u and a lower limit value Q〓 L are stored, and the discrimination circuit 21 uses the upper limit value Q〓 u and lower limit value Q〓 L stored in the memory 22 and the detected intake air amount. When the detected intake air amount Q is larger than the upper limit value Q〓u and smaller than the lower limit value Q〓L , it is determined that the intake air amount sensor 11 is abnormal. When the intake air amount sensor 11 is normal, the basic injection amount calculation circuit 17 calculates the basic injection amount Tp based on the intake air amount Q and the engine speed N according to the following equation.
Tp＝Ｋ・Ｑ／Ｎ（但し、Ｋ：比例定数） ……(1)
一方、補助噴射量演算手段１８は補助噴射量演
算回路２３とメモリ２４により構成されており、
吸気量センサ１１が異常のとき、絞り弁開度θと
機関回転数Ｎに基づいて補助噴射量TpBを演算す
る。すなわち、補助噴射量演算回路２３は、あら
かじめ絞り弁開度θと機関回転数Ｎをパラメータ
としてメモリ２４に記憶された補助噴射量TpBの
データテーブルより、入力される絞り弁開度θと
機関回転数Ｎに基づいて最適の補助噴射量TpBを
ルツクアツプする。この補助噴射量TpBは吸気量
センサ１１が正常であるときの基本噴射量Tpに
対応するものである。Tp=K・Q/N (K: proportionality constant) ...(1) On the other hand, the auxiliary injection amount calculation means 18 is composed of an auxiliary injection amount calculation circuit 23 and a memory 24,
When the intake air amount sensor 11 is abnormal, the auxiliary injection amount Tp B is calculated based on the throttle valve opening θ and the engine speed N. That is, the auxiliary injection amount calculation circuit 23 calculates the input throttle valve opening θ and the engine from the data table of the auxiliary injection amount Tp B stored in the memory 24 using the throttle valve opening θ and the engine rotational speed N as parameters. Look up the optimum auxiliary injection amount Tp B based on the rotational speed N. This auxiliary injection amount Tp B corresponds to the basic injection amount Tp when the intake air amount sensor 11 is normal.
最終噴射量演算回路１９は基本噴射量Tpある
いは補助噴射量TpBに機関の運転状態に基づく各
種補正、例えば、水温補正、アイドル後増量補
正、始動後増量補正、空燃比フイードバツク補正
等を行つて最終噴射量Toを演算する。 The final injection amount calculation circuit 19 performs various corrections on the basic injection amount Tp or the auxiliary injection amount Tp B based on the operating state of the engine, such as water temperature correction, post-idling amount increase correction, post-start amount increase correction, air-fuel ratio feedback correction, etc. Calculate the final injection amount To.
出力回路２０は最終噴射量Toに対応するデユ
ーテイ値のパルス信号を噴射信号として噴射手段
２５に出力する。 The output circuit 20 outputs a pulse signal having a duty value corresponding to the final injection amount To to the injection means 25 as an injection signal.
噴射手段２５は、例えば、機関の吸気管に取り
付けられた電子制御式燃料噴射ノズルであり、最
終噴射量の燃料を機関の吸気管内に噴射する。 The injection means 25 is, for example, an electronically controlled fuel injection nozzle attached to the intake pipe of the engine, and injects the final injection amount of fuel into the intake pipe of the engine.
次に作用を、第３図に示すフローチヤートに基
づいて説明する。なお、このフローは機関の回転
と同期してあるいは所定時間毎に実行され、第３
図中P1〜P8はフローの各ステツプを表示する。 Next, the operation will be explained based on the flowchart shown in FIG. Note that this flow is executed in synchronization with the rotation of the engine or at predetermined intervals.
In the figure, P1 to P8 indicate each step of the flow.
まず、ステツプP1において、吸入空気量Ｑ、
機関回転数Ｎおよび絞り弁開度θを読み込む。こ
のとき、吸気量センサ１１の出力は、吸入空気量
Ｑと、絞り弁開度θとの関係をよりよく表示させ
るために、絞り弁開度θに対して、第４図に実線
で表示する値に設定されており、この場合、この
波線で表示する出力値としてもよい。次いで、ス
テツプP2において、あらかじめメモリ２２に記
憶されたデータテーブルより絞り弁開度θに対応
する吸入空気量Ｑの上限値Q〓uと下限値Q〓Lをルツ
クアツプする。この上限値Q〓uと下限値Q〓Lは、第
５図に表示するように、絞り弁開度θに対応する
吸入空気量Ｑの理論値ｌを中心として、所定の誤
差を許容する値として与えられ、ある絞り弁開度
θにおける吸入空気量Ｑがこの誤差内にあれば、
すなわち、上限値Q〓uと下限値Q〓Lの間にあれば吸
気量センサ１１は正常であり、この誤差を越える
ときは吸気量センサ１１は異常である。そこで、
ステツプP3において、吸入空気量Ｑが上限値Q〓u
と下限値Q〓Lの間にあるかどうかにより、吸気量
センサ１１が正常であるか異常であるかを判別し
ている。したがつて、異常発生時には燃料噴射量
が異常に多くなつたりまた少なくなつたりして運
転性能および排気性能を悪化させることなく、異
常を直ちに判別することができる。この場合、機
関の全性能マツプにおける等吸入空気量線LQと
等絞り弁開度Lθは、第６図のように表示される。
したがつて、特願昭58−29674号明細書記載のも
のにあつては、機関回転Ｎと吸入空気量Ｑに基づ
いて吸気量センサ１１の異常を判別していたの
で、例えば、回転数ＮがN1のときにおける吸入
空気量Ｑは、第６図中Ａ点からＤ点までの広い範
囲であり、過給機の取り付けられていない通常の
機関では、Ｄ点の吸入負圧が−500mmHg（絶対
値：260mmHg）、Ａ点の吸入負圧が−20mmHg（絶
対値：740mmHg）程度であるので、吸入空気量比
は約740／260＝2.8倍となつていた。その結果、
上記先願のものにあつては、測定誤差やバラツキ
等を考慮すると、吸気量センサの正常領域を吸入
空気量比で約３倍以上に設定する必要があり、吸
気量センサの異常判別精度を十分向上させること
ができなかつた。しかしながら、本発明において
は、吸入空気量Ｑと密接な関係のある絞り弁開度
θと吸入空気量Ｑに基づいて吸気量センサ１１の
異常を判別しているので、ある吸入空気量Ｑと絞
り弁開度θに対して、第６図に２点鎖線で表示す
る狭い領域内を正常領域として設定することがで
き、この場合、ある機関回転数N1に対してＢ点
からＣ点間を正常領域として設定することができ
る。したがつて、Ｂ点が−50mmHg（絶対値：710
mmHg）、Ｃ点が−100mmHg（絶対値：660mmHg）
であると、正常領域は吸入空気量比で約710／660
＝1.076倍となり、吸気量センサ１１の異常判別
精度を大幅に向上させることができる。 First, in step P1 , the intake air amount Q,
Read the engine speed N and throttle valve opening θ. At this time, the output of the intake air amount sensor 11 is shown as a solid line in FIG. 4 with respect to the throttle valve opening θ in order to better display the relationship between the intake air amount Q and the throttle valve opening θ. In this case, the output value may be displayed as a wavy line. Next, in step P2 , the upper limit value Q〓u and lower limit value Q〓L of the intake air amount Q corresponding to the throttle valve opening degree θ are looked up from the data table stored in the memory 22 in advance. The upper limit value Q〓 u and lower limit value Q〓 L are values that allow a predetermined error around the theoretical value l of the intake air amount Q corresponding to the throttle valve opening θ, as shown in Fig. 5. If the intake air amount Q at a certain throttle valve opening θ is within this error,
That is, if the error is between the upper limit value Q〓u and the lower limit value Q〓L , the intake air amount sensor 11 is normal, and when this error is exceeded, the intake air amount sensor 11 is abnormal. Therefore,
At step P3 , the intake air amount Q reaches the upper limit Q〓 u
It is determined whether the intake air amount sensor 11 is normal or abnormal depending on whether it is between the lower limit value Q〓L and the lower limit value Q〓L . Therefore, when an abnormality occurs, the abnormality can be immediately determined without deteriorating the driving performance and exhaust performance due to the fuel injection amount being abnormally increased or decreased. In this case, the equal intake air amount line LQ and the equal throttle valve opening Lθ in the overall performance map of the engine are displayed as shown in FIG.
Therefore, in the case described in the specification of Japanese Patent Application No. 58-29674, the abnormality of the intake air amount sensor 11 is determined based on the engine rotation N and the intake air amount Q. The amount of intake air Q when is N 1 is in a wide range from point A to point D in Figure 6, and in a normal engine without a supercharger, the negative suction pressure at point D is -500 mmHg. (absolute value: 260 mmHg), and the suction negative pressure at point A was about -20 mmHg (absolute value: 740 mmHg), so the intake air amount ratio was approximately 740/260 = 2.8 times. the result,
In the case of the above-mentioned earlier application, considering measurement errors and variations, it is necessary to set the normal range of the intake air amount sensor to approximately three times the intake air amount ratio or more, and the accuracy of abnormality determination of the intake air amount sensor is reduced. I couldn't improve it enough. However, in the present invention, an abnormality in the intake air amount sensor 11 is determined based on the throttle valve opening θ and the intake air amount Q, which are closely related to the intake air amount Q. For the valve opening θ, the narrow region shown by the two-dot chain line in Fig. 6 can be set as the normal region. Can be set as normal area. Therefore, point B is -50mmHg (absolute value: 710
mmHg), point C is -100mmHg (absolute value: 660mmHg)
Then, the normal range is the intake air amount ratio of approximately 710/660.
= 1.076 times, and the abnormality determination accuracy of the intake air amount sensor 11 can be greatly improved.
ステツプP3において、吸入空気量Ｑが上限値
Q〓uと下限値Q〓Lのあいだにあるときには、吸気量
センサ１１は正常であると判断して、ステツプ
P4において(1)式により基本噴射量Tpを演算し、
吸入空気量Ｑが上限値Q〓uと下限値Q〓Lの間にない
ときには、吸気量センサ１１が異常であると判断
してステツプP5において、第７図に示すように、
機関回転数Ｎと絞り弁開度θをパラメータとして
あらかじめメモリ２４に記憶されたデータテーブ
ルより補助噴射量TpBをルツクアツプする。した
がつて、吸気量センサ１１が異常の場合において
も機関の運転状態により一層適した噴射量を設定
することができ、機関の運転性能をより一層向上
させることができる。そして、ステツプP6にお
いて補助噴射量TpBを基本噴射量Tpとして設定
し、ステツプP7において、機関の運転状態に基
づく補正を基本噴射量Tpあるいは補助噴射量
TpBに施して最終噴射量Toを演算する。ステツ
プP8において、最終噴射量Toに対応するデユー
テイ値の噴射信号を噴射手段２５に出力し、噴射
手段２５から最終噴射量の燃料が機関の吸気管内
に噴射される。 At step P 3 , the intake air amount Q reaches the upper limit.
When the value is between Q〓 u and the lower limit value Q〓 L , it is determined that the intake air amount sensor 11 is normal, and the step
In P 4 , calculate the basic injection amount Tp using equation (1),
When the intake air amount Q is not between the upper limit value Q〓u and the lower limit value Q〓L , it is determined that the intake air amount sensor 11 is abnormal, and in step P5 , as shown in FIG.
The auxiliary injection amount Tp B is looked up from a data table stored in the memory 24 in advance using the engine speed N and the throttle valve opening θ as parameters. Therefore, even when the intake air amount sensor 11 is abnormal, it is possible to set an injection amount that is more suitable for the operating state of the engine, and the operating performance of the engine can be further improved. Then, in step P6 , the auxiliary injection amount TpB is set as the basic injection amount Tp, and in step P7 , the correction based on the operating state of the engine is set as the basic injection amount Tp or the auxiliary injection amount.
Tp B is applied to calculate the final injection amount To. In step P8 , an injection signal having a duty value corresponding to the final injection amount To is output to the injection means 25, and the final injection amount of fuel is injected from the injection means 25 into the intake pipe of the engine.
（効果）
本発明によれば、吸気量センサの異常を吸入空
気量と吸入空気量に密接な関係を有する絞り弁開
度に基づいて判別することができるので、吸気量
センサの異常判別精度をより一層向上させること
ができ、吸気量センサの異常をより一層的確に判
別することができる。また、吸気量センサの異常
を直ちに判定し、絞り弁開度と機関回転数に基づ
いて補助噴射量を演算し、この補助噴射量に基づ
いた燃料量を噴射するようにしたので、断線、短
絡等吸気量センサが異常となつた直後に噴射され
る燃料量が異常に多くなつたりあるいは異常に少
なくなつたりして、機関の運転性能および排気性
能が悪化するのを防止することができる。さら
に、吸気量センサの異常時に、絞り弁開度と機関
回転数に基づいて燃料量を設定することができる
ので、機関の運転状態により一層適した噴射量に
設定することができ、機関の運転性能をより一層
向上させることができるとともに、触媒コンバー
タの焼損を防止することができる。(Effects) According to the present invention, an abnormality in the intake air amount sensor can be determined based on the intake air amount and the opening degree of the throttle valve, which has a close relationship with the intake air amount. It is possible to further improve the performance, and it is possible to more accurately determine an abnormality in the intake air amount sensor. In addition, the system immediately determines if there is an abnormality in the intake air amount sensor, calculates the auxiliary injection amount based on the throttle valve opening and engine speed, and injects the amount of fuel based on this auxiliary injection amount. It is possible to prevent the operational performance and exhaust performance of the engine from deteriorating due to the amount of fuel injected being abnormally increased or decreased immediately after the equal intake amount sensor becomes abnormal. Furthermore, in the event of an abnormality in the intake air amount sensor, the fuel amount can be set based on the throttle valve opening and engine speed, so it is possible to set the injection amount to be more suitable for the engine operating condition. Performance can be further improved, and burnout of the catalytic converter can be prevented.
第１図は本発明の内燃機関の燃料噴射制御装置
を示す全体構成図、第２図から第７図は本発明の
一実施例を示す図であり、第２図はその全体構成
を示すブロツク図、第３図はその作用を示すフロ
ーチヤート、第４図はその吸気量センサの出力特
性図、第５図はその絞り弁開度に対応して与えら
れる吸入空気量の上限値と下限値を示す図、第６
図はその機関の全性能マツプにおける等吸入空気
量線と等絞り弁開度線を示す図、第７図はその機
関回転数と吸入空気量をパラメータとして与えら
れる補助噴射量のデータテーブル、第８図は従来
の内燃機関の燃料噴射制御装置を示す構成図であ
る。
１１……吸気量センサ、１２……回転数セン
サ、１３……絞り弁開度センサ、１６……判別手
段、１７……基本噴射量演算手段、１８……補助
噴射量演算手段、１９……最終噴射演算手段、２
１……判別回路（判別する手段）、２２……メモ
リ（記憶する手段）、２５……噴射手段。
FIG. 1 is an overall configuration diagram showing a fuel injection control device for an internal combustion engine according to the present invention, FIGS. 2 to 7 are diagrams showing an embodiment of the invention, and FIG. 2 is a block diagram showing the overall configuration. Figure 3 is a flowchart showing its operation, Figure 4 is an output characteristic diagram of the intake air amount sensor, and Figure 5 is the upper and lower limits of the intake air amount given corresponding to the throttle valve opening. Figure 6 showing
The figure shows the equal intake air amount line and the equal throttle valve opening line in the overall performance map of the engine, Figure 7 is a data table of the auxiliary injection amount given with the engine speed and intake air amount as parameters, FIG. 8 is a configuration diagram showing a conventional fuel injection control device for an internal combustion engine. 11... Intake amount sensor, 12... Rotation speed sensor, 13... Throttle valve opening sensor, 16... Discrimination means, 17... Basic injection amount calculation means, 18... Auxiliary injection amount calculation means, 19... Final injection calculation means, 2
1... Discrimination circuit (discriminating means), 22... Memory (storing means), 25... Injection means.
Claims (1)
と、機関の回転数を検出する回転数センサと、機
関の絞り弁の開度を検出する絞り弁開度センサ
と、検出された絞り弁開度に対応して設定され
夫々絞り弁開度が大きくなる程大きい値となるよ
うに設定された吸入空気量の上限値と下限値とを
記憶している手段と、検出された絞り弁開度に対
応する前記上限値および下限値と検出された吸入
空気量とを比較し、検出された吸入空気量が上限
値より大きいときおよび下限値より小さいときに
吸気量センサが異常であると判別する手段と、吸
気量センサが正常のとき、吸入空気量と機関回転
数に基づいて燃料の基本噴射量を演算する基本噴
射量演算手段と、吸気量センサが異常のとき、絞
り弁開度と機関回転数に基づいて燃料の補助噴射
量を演算する補助噴射量演算手段と、前記基本噴
射量または補助噴射量を機関の運転状態に基づい
て補正して最終噴射量を演算する最終噴射量演算
手段と、最終噴射量の燃料を噴射する噴射手段
と、を備えたことを特徴とする内燃機関の燃料噴
射制御装置。1. An intake air amount sensor that detects the intake air amount of the engine, a rotation speed sensor that detects the engine speed, a throttle valve opening sensor that detects the opening of the engine throttle valve, and the detected throttle valve opening. means for storing an upper limit value and a lower limit value for the intake air amount, which are set corresponding to the throttle valve opening degree, and are set such that the value increases as the throttle valve opening degree increases; Means for comparing the detected intake air amount with the corresponding upper limit value and lower limit value, and determining that the intake air amount sensor is abnormal when the detected intake air amount is larger than the upper limit value and smaller than the lower limit value. and a basic injection amount calculation means that calculates the basic injection amount of fuel based on the intake air amount and engine speed when the intake air amount sensor is normal, and a basic injection amount calculation means that calculates the basic injection amount of fuel based on the intake air amount and engine speed when the intake air amount sensor is abnormal. auxiliary injection amount calculation means for calculating an auxiliary injection amount of fuel based on the number; and final injection amount calculation means for calculating a final injection amount by correcting the basic injection amount or the auxiliary injection amount based on the operating state of the engine. 1. A fuel injection control device for an internal combustion engine, comprising: an injection means for injecting a final injection amount of fuel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18144784A JPS6158945A (en) | 1984-08-29 | 1984-08-29 | Full injection control device for internal-combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18144784A JPS6158945A (en) | 1984-08-29 | 1984-08-29 | Full injection control device for internal-combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6158945A JPS6158945A (en) | 1986-03-26 |
| JPH0255616B2 true JPH0255616B2 (en) | 1990-11-27 |
Family
ID=16100926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18144784A Granted JPS6158945A (en) | 1984-08-29 | 1984-08-29 | Full injection control device for internal-combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6158945A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10340844B4 (en) * | 2002-09-04 | 2010-07-08 | Honda Giken Kogyo K.K. | Device and method for fault determination in an air flow sensor |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62233452A (en) * | 1986-03-31 | 1987-10-13 | Mitsubishi Electric Corp | Fuel control device |
| JP2503453B2 (en) * | 1986-11-11 | 1996-06-05 | 日本電装株式会社 | Air-fuel ratio control device for internal combustion engine |
| DE3729635A1 (en) * | 1987-09-04 | 1989-03-16 | Bosch Gmbh Robert | ADJUSTMENT SYSTEM (CONTROL AND / OR REGULATION SYSTEM) FOR MOTOR VEHICLES |
| JPH0281937A (en) * | 1988-09-20 | 1990-03-22 | Fuji Heavy Ind Ltd | Air-fuel ratio control device |
| DE4229774C2 (en) * | 1992-09-05 | 2002-06-20 | Bosch Gmbh Robert | Device for controlling an internal combustion engine |
| DE10039785B4 (en) * | 2000-08-16 | 2014-02-13 | Robert Bosch Gmbh | Method and device for operating an internal combustion engine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5532919A (en) * | 1978-08-25 | 1980-03-07 | Nissan Motor Co Ltd | Fuel controller of internal combustion engine |
-
1984
- 1984-08-29 JP JP18144784A patent/JPS6158945A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5532919A (en) * | 1978-08-25 | 1980-03-07 | Nissan Motor Co Ltd | Fuel controller of internal combustion engine |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10340844B4 (en) * | 2002-09-04 | 2010-07-08 | Honda Giken Kogyo K.K. | Device and method for fault determination in an air flow sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6158945A (en) | 1986-03-26 |
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