JP2000282906A - Lean combustion internal combustion engine - Google Patents
Lean combustion internal combustion engineInfo
- Publication number
- JP2000282906A JP2000282906A JP11086041A JP8604199A JP2000282906A JP 2000282906 A JP2000282906 A JP 2000282906A JP 11086041 A JP11086041 A JP 11086041A JP 8604199 A JP8604199 A JP 8604199A JP 2000282906 A JP2000282906 A JP 2000282906A
- Authority
- JP
- Japan
- Prior art keywords
- negative pressure
- supercharging
- intake
- internal combustion
- combustion engine
- 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
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Supercharger (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、内燃機関本体の吸
入空気量調整機構の下流側の負圧を利用して作動する負
圧倍力装置を備えた自動車用内燃機関に係わり、特に過
給機を搭載し、且つ空燃比を希薄化して燃費の向上を図
るようにした希薄燃焼内燃機関において、前記負圧倍力
装置の作動を保証するようにした希薄燃焼内燃機関に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine for a vehicle having a negative pressure booster which operates by using a negative pressure on the downstream side of an intake air amount adjusting mechanism of an internal combustion engine body, and particularly to a supercharger. The present invention relates to a lean-burn internal combustion engine in which an air-fuel ratio is reduced and an air-fuel ratio is reduced to improve fuel efficiency.
【０００２】[0002]
【従来の技術】自動車用のブレーキ機構におけるブレー
キペダルの踏力を増大させる負圧倍力装置には、例え
ば、内燃機関の吸気通路に設けた吸入空気量調整手段
（スロットル弁）の下流に発生する負圧を利用したもの
がある。一方、空燃比を希薄化してリーン空燃比での運
転を可能とし燃費の向上を図るようにした希薄燃焼内燃
機関に、内燃機関本体内への吸気を過給する過給手段を
備え、高出力と低燃費を狙った技術が例えば、特開平４
−１７７４３号公報に開示されている。2. Description of the Related Art A negative pressure booster for increasing the depression force of a brake pedal in a brake mechanism for an automobile is generated, for example, downstream of intake air amount adjusting means (throttle valve) provided in an intake passage of an internal combustion engine. Some use negative pressure. On the other hand, the lean-burn internal combustion engine, which has a lean air-fuel ratio to enable operation at a lean air-fuel ratio to improve fuel efficiency, is provided with a supercharging means for supercharging intake air into the internal combustion engine main body, thereby achieving high output. For example, Japanese Patent Laid-Open No.
-17743.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記公
報に開示されている技術は、希薄燃焼が行われ、しか
も、過給手段により吸気が過給されているため、多量の
吸気が内燃機関本体に供給されることとなる。このた
め、吸気通路のスロットル弁下流側の負圧が低下する虞
がある。However, in the technique disclosed in the above publication, lean combustion is performed, and the intake air is supercharged by the supercharging means. Will be supplied. For this reason, the negative pressure downstream of the throttle valve in the intake passage may be reduced.
【０００４】従って、上記過給手段付希薄燃焼内燃機関
を備えた車両において、ブレーキ機構に吸気通路のスロ
ットル弁下流側の負圧を利用する負圧倍力装置を用いた
場合、前記内燃機関の運転状態によっては負圧倍力装置
への安定した負圧が確保できず、負圧倍力装置が十分に
作動し得ない虞が生じる。このため、本発明では、過給
機を搭載した希薄燃焼内燃機関において、ブレーキ機構
における負圧倍力装置への安定した負圧を確保して、そ
の作動を保証するようにした希薄燃焼内燃機関を提供す
ることを目的としている。Therefore, in a vehicle equipped with the above-described lean-burn internal combustion engine with supercharging means, when a negative pressure booster that uses a negative pressure downstream of a throttle valve in an intake passage is used for a brake mechanism, the internal combustion engine has Depending on the operation state, a stable negative pressure to the negative pressure booster cannot be secured, and the negative pressure booster may not operate sufficiently. Therefore, according to the present invention, in a lean-burn internal combustion engine equipped with a supercharger, a lean-burn internal combustion engine in which a stable negative pressure is applied to a negative pressure booster in a brake mechanism to ensure the operation thereof is ensured. It is intended to provide.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するた
め、本発明では、過給手段により吸気通路に吸入空気を
過給すると共に、吸気量調整手段により内燃機関の吸気
通路の開口面積を変更して燃焼室内への吸気量を調整し
て空燃比を希薄化して燃費の向上を図る。希薄燃焼が行
われ、過給手段により過給されて多量の吸気が内燃機関
本体に供給されると、吸入空気量調整手段の下流側の負
圧が低下する。制御手段は、負圧低下検知手段により前
記負圧倍力装置に作用する負圧低下が検出又は推定され
た場合、過給圧が低過給圧側になるように前記過給圧調
整手段を制御して前記負圧倍力装置の作動を保証する負
圧を確保する。これにより、吸気通路の吸入空気量調整
手段の下流側から取り出される負圧を利用して作動する
負圧倍力装置の作動を保証する。In order to achieve the above object, according to the present invention, the intake air is supercharged into an intake passage by a supercharging means, and the opening area of the intake passage of an internal combustion engine is changed by an intake air amount adjusting means. By adjusting the amount of intake air into the combustion chamber, the air-fuel ratio is made lean to improve fuel efficiency. When lean combustion is performed and a large amount of intake air is supplied to the internal combustion engine main body by being supercharged by the supercharging means, the negative pressure on the downstream side of the intake air amount adjusting means decreases. The control means controls the supercharging pressure adjusting means such that the supercharging pressure is on the low supercharging pressure side when the negative pressure drop detecting means detects or estimates a negative pressure drop acting on the negative pressure booster. Then, a negative pressure that guarantees the operation of the negative pressure booster is secured. This guarantees the operation of the negative pressure booster that operates using the negative pressure taken from the intake passage downstream of the intake air amount adjusting means in the intake passage.
【０００６】[0006]
【発明の実施の形態】以下、図面を参照して本発明の好
適な実施例を例示的に詳しく説明する。図１は、本発明
に係る過給機を搭載した希薄燃焼内燃機関の概略構成を
示すブロック図である。図１において内燃機関本体（以
下「エンジン本体という」）１は、希薄燃焼可能な例え
ば、筒内噴射型のガソリンエンジンで、吸気通路２に
は、吸入空気量情報としての吸入空気量を計測するエア
フローセンサ５、吸入空気を過給する過給機としての可
変ターボチャージャ（以下単に「ターボチャージャ」と
いう）７のコンプレッサ８、ステップモータにより駆動
されてエンジン１に供給する吸入空気量を制御する吸入
空気量調整手段としての電子スロットルバルブ（以下単
に「スロットル弁」という）６が設けられており、排気
通路３には、コンプレッサ８と同軸に結合されて排気ガ
スにより回転駆動されるタービン９が設けられている。DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a lean burn internal combustion engine equipped with a supercharger according to the present invention. In FIG. 1, an internal combustion engine main body (hereinafter referred to as “engine main body”) 1 is, for example, a direct injection type gasoline engine capable of lean combustion, and an intake passage 2 measures an intake air amount as intake air amount information. An airflow sensor 5, a compressor 8 of a variable turbocharger (hereinafter simply referred to as “turbocharger”) 7 as a supercharger for supercharging intake air, and an intake driven by a step motor to control the amount of intake air supplied to the engine 1. An electronic throttle valve (hereinafter simply referred to as "throttle valve") 6 is provided as air amount adjusting means, and a turbine 9 which is coaxially coupled with the compressor 8 and is driven to rotate by exhaust gas is provided in the exhaust passage 3. Have been.
【０００７】ターボチャージャ７は、タービン９に導入
する排気ガスエネルギを調節する可変部材としての可変
ノズルベーン（以下単に「ベーン」という）１０が設け
られている。このベーン１０は、ベーン調整アクチュエ
ータとしての電子制御アクチュエータ例えば、ステッパ
モータ１１により駆動される。エンジン本体１の高速運
転領域ではベーン１０を開放して大量の排気エネルギを
利用してタービン９を高回転させ、低速運転領域ではベ
ーン１０を絞り少ない排気エネルギでもタービン９を高
回転させる。従って、ベーン１０は、過給圧を調整する
過給圧調整手段として機能する。これにより、ターボチ
ャージャ７は、エンジン本体１の広い運転領域で低燃
費、高トルクというターボ効果を発揮する。[0007] The turbocharger 7 is provided with a variable nozzle vane (hereinafter simply referred to as “vane”) 10 as a variable member for adjusting the energy of exhaust gas introduced into the turbine 9. The vane 10 is driven by an electronic control actuator as a vane adjustment actuator, for example, a stepper motor 11. In the high-speed operation region of the engine body 1, the vanes 10 are opened and the turbine 9 is rotated at high speed by using a large amount of exhaust energy. In the low-speed operation region, the vanes 10 are throttled and the turbine 9 is rotated at high speed even with small exhaust energy. Therefore, the vane 10 functions as a boost pressure adjusting unit that adjusts the boost pressure. Thereby, the turbocharger 7 exhibits a turbo effect of low fuel consumption and high torque in a wide operating region of the engine body 1.
【０００８】吸気通路２のスロットル弁６の下流側に設
けられたサージタンク４には、ブレーキペダル１３の踏
力を増大させる負圧倍力装置１４が通路１６を介して接
続されている。この負圧倍力装置１４は、負圧アクチュ
エータで、エンジン本体１の作動によりその内部に生じ
る負圧（吸気管圧力）を利用してブレーキペダル１３の
踏力を増大させてマスタシリンダ１５を作動させ、車両
に対する制動力を発生させる。そして、この負圧倍力装
置１４に利用される負圧は、負圧倍力装置１４に設けら
れた負圧検出手段としての負圧センサ２０により検出さ
れる。A negative pressure booster 14 for increasing the depression force of a brake pedal 13 is connected via a passage 16 to the surge tank 4 provided on the downstream side of the throttle valve 6 in the intake passage 2. The negative pressure booster 14 is a negative pressure actuator, and operates the master cylinder 15 by increasing the depression force of the brake pedal 13 by using a negative pressure (intake pipe pressure) generated inside the engine body 1 by the operation of the engine body 1. To generate a braking force on the vehicle. The negative pressure used in the negative pressure booster 14 is detected by a negative pressure sensor 20 provided as a negative pressure detecting means provided in the negative pressure booster 14.
【０００９】また、吸気通路２と排気通路３とはＥＧＲ
通路１７により連通されており、このＥＧＲ通路１７に
はＥＧＲ弁１８が設けられている。エンジン本体１から
排気通路３に排出された排気ガスの一部がＥＧＲ通路１
７を通して吸気通路２に導入されて再循環されて浄化さ
れる。この排気ガスの再循環量は、エンジンの運転状態
に応じてステッパモータ式のＥＧＲ弁１８により制御さ
れる。具体的には、上述した後期噴射モードと、前期噴
射モードのストイキオフィードバック制御が行われてい
るときに開弁制御され、後期噴射モードの方が前期噴射
モードに比べ多量に排気ガスが再循環されるようＥＧＲ
弁１８が制御される。The intake passage 2 and the exhaust passage 3
The EGR passage 17 communicates with a passage 17, and an EGR valve 18 is provided in the EGR passage 17. Part of the exhaust gas discharged from the engine body 1 to the exhaust passage 3 is
The gas is introduced into the intake passage 2 through 7 and is recirculated and purified. The recirculation amount of the exhaust gas is controlled by a stepper motor type EGR valve 18 according to the operation state of the engine. More specifically, the valve opening control is performed during the stoichiometric feedback control of the above-described second-stage injection mode and the first-stage injection mode, and a larger amount of exhaust gas is recirculated in the second-stage injection mode than in the first-stage injection mode. EGR as
Valve 18 is controlled.
【００１０】制御手段としての電子制御装置（ＥＣＵ）
２５は、エンジン本体１の総合的な判断を行うもので入
力側にはエアフローセンサ５、負圧センサ２０の他に、
スロットル開度（アクセル開度）を検出するアクセルポ
ジションセンサ、エンジン本体１の回転数を検出するエ
ンジン回転センサ、ターボチャージャ７による過給圧を
検出する過給圧センサ、車速センサ、エンジン冷却水の
温度を検出する温度センサ（何れも図示せず）等が接続
されており、出力側には、スロットル弁６を制御するた
めの電子スロットル制御ユニット２６、ターボチャージ
ャ７のステッパモータ１１、ＥＧＲ弁１８の他に、点火
プラグ、燃料噴射弁（何れも図示せず）等が接続されて
いる。Electronic control unit (ECU) as control means
Numeral 25 is for making a comprehensive judgment of the engine main body 1. On the input side, in addition to the airflow sensor 5 and the negative pressure sensor 20,
An accelerator position sensor that detects a throttle opening (accelerator opening), an engine rotation sensor that detects the number of revolutions of the engine body 1, a supercharging pressure sensor that detects a supercharging pressure by the turbocharger 7, a vehicle speed sensor, and engine cooling water. A temperature sensor (neither is shown) or the like for detecting the temperature is connected. An electronic throttle control unit 26 for controlling the throttle valve 6, a stepper motor 11 of the turbocharger 7, an EGR valve 18 are provided on the output side. In addition, a spark plug, a fuel injection valve (both not shown) and the like are connected.
【００１１】電子制御装置２５は、前記各センサから入
力される信号に基づいて、点火時期、燃料噴射モード
（後述する）、燃料噴射時間（燃料噴射量）等を決定し
て点火プラグ、燃料噴射弁、ＥＧＲ弁１８等を制御する
と共に、ターボチャージャ７のベーン開度を決定して、
ステッパモータ１１を駆動制御する。また、電子制御装
置２５は、電子スロットル制御ユニット２６に出力して
スロットル弁６のスロットル開度（アクセル開度）を決
定する。The electronic control unit 25 determines an ignition timing, a fuel injection mode (to be described later), a fuel injection time (fuel injection amount), and the like based on signals input from each of the sensors, and sets an ignition plug, fuel injection, and the like. Control the valves, the EGR valve 18 and the like, determine the vane opening of the turbocharger 7,
The drive of the stepper motor 11 is controlled. Further, the electronic control unit 25 outputs to the electronic throttle control unit 26 to determine the throttle opening (accelerator opening) of the throttle valve 6.
【００１２】以下に作用を説明する。まず、希薄燃焼内
燃機関としての筒内噴射型エンジンに特有の燃料噴射制
御の概要を説明する。エンジン本体１は、燃焼室内に直
接燃料を噴射する作動原理上、任意に燃料噴射時期を設
定することができ、例えば、本実施形態のエンジンでは
低負荷運転域において圧縮行程で燃料噴射を行う（後期
噴射モード）ことにより、点火プラグの周囲にストイキ
オ（理論空燃比）近傍の混合気を形成した上で、全体と
して空燃比が４０程度の極めてリーンな空燃比での燃焼
（層状燃焼）を実行し、中・高負荷運転域においては、
吸気行程で燃料噴射を行う（前期噴射モード）ことによ
り燃焼室内に均一な混合気を形成し、空燃比１２〜２３
程度と広範な空燃比での燃焼（均一燃焼）を実行してい
る。The operation will be described below. First, an outline of fuel injection control specific to a direct injection engine as a lean burn internal combustion engine will be described. The engine main body 1 can arbitrarily set the fuel injection timing on the operating principle of directly injecting the fuel into the combustion chamber. For example, in the engine of the present embodiment, the fuel is injected in the compression stroke in the low load operation range ( After the formation of the air-fuel mixture near the stoichiometric ratio (stoichiometric air-fuel ratio) around the ignition plug by the latter injection mode, the combustion (stratified combustion) with an extremely lean air-fuel ratio of about 40 as a whole is performed. In the medium and high load operation range,
By performing fuel injection during the intake stroke (first-stage injection mode), a uniform mixture is formed in the combustion chamber, and the air-fuel ratio is 12 to 23.
Combustion (uniform combustion) with a wide range of air-fuel ratios is performed.
【００１３】具体的には、燃料噴射モード及び目標空燃
比は、アクセルポジションセンサにより検出されたスロ
ットル開度等から求めた目標平均有効圧、エンジン回転
数、吸入空気量等の各種センサ情報に基づいて決定して
いる。例えば、目標平均有効圧とエンジン回転数が共に
低い低負荷・低回転域では、燃費節約とエミッション低
減を目的として、後期噴射モードを選択すると共にエン
ジンの要求に合ったリーン側の目標空燃比を設定する。
そして、その目標空燃比から決定した燃料噴射時期に基
づいて燃料噴射制御ルーチンに従って燃料噴射弁を制御
して燃料噴射を実行する。More specifically, the fuel injection mode and the target air-fuel ratio are based on various kinds of sensor information such as a target average effective pressure, an engine speed, and an intake air amount obtained from a throttle opening detected by an accelerator position sensor. Is determined. For example, in the low-load / low-speed range where both the target average effective pressure and the engine speed are low, for the purpose of saving fuel and reducing emissions, select the late injection mode and set the target air-fuel ratio on the lean side that meets the requirements of the engine. Set.
Then, the fuel injection valve is controlled in accordance with the fuel injection control routine based on the fuel injection timing determined from the target air-fuel ratio to execute the fuel injection.
【００１４】電子制御装置２５は、以上のエンジン制御
を実行しつつ、ターボチャージャ７のタービン９のベー
ン開度制御を実行して、吸気通路２の過給圧を調整し、
負圧倍力装置１４への安定した負圧を確保して、当該負
圧倍力装置１４の作動を保証する制御を実行する。次
に、図２に示すフローチャートを参照してブレーキ負圧
制御について説明する。The electronic control unit 25 executes the vane opening control of the turbine 9 of the turbocharger 7 while performing the above-described engine control, thereby adjusting the supercharging pressure of the intake passage 2.
The control which ensures the stable negative pressure to the negative pressure booster 14 and guarantees the operation of the negative pressure booster 14 is executed. Next, the brake negative pressure control will be described with reference to the flowchart shown in FIG.
【００１５】電子制御装置２５は、エンジン本体１の運
転状態を読み込み（ステップＳ１）、当該エンジン本体
１の運転状態がブレーキ負圧制御ゾーンにあるか否かを
判別する（ステップＳ２）。このブレーキ負圧制御ゾー
ンは、スロットル開度により判別され、例えば、スロッ
トル開度が全開近くにならずサージタンク４の負圧が大
気圧にならないとき、即ち、サージタンク４に負圧が多
少あり、未だ負圧を確保することが可能な運転状態であ
る（ブレーキ負圧制御ゾーンでない）と判別される。The electronic control unit 25 reads the operating state of the engine body 1 (step S1), and determines whether the operating state of the engine body 1 is in the brake negative pressure control zone (step S2). This brake negative pressure control zone is determined by the throttle opening. For example, when the throttle opening does not become nearly full and the negative pressure of the surge tank 4 does not reach the atmospheric pressure, that is, there is a slight negative pressure in the surge tank 4. It is determined that the operation state is such that the negative pressure can still be secured (not in the brake negative pressure control zone).
【００１６】エンジン本体１がリーン空燃比で運転され
ており、ステップＳ２においてブレーキ負圧制御ゾーン
にないと判別されたときには、サージタンク４の負圧が
負圧倍力装置１４の作動を保証する大きさに確保された
状態にあり、ブレーキ負圧制御は必要ではなく当該制御
ルーチンを終了する。ステップＳ２においてブレーキ負
圧制御ゾーンにあると判別されたときには、サージタン
ク４内の負圧が負圧倍力装置１４の作動を保証できる負
圧（以下「ブレーキ負圧」という）か否かが判定される
（ステップＳ３）。即ち、負圧センサ２０により検出さ
れたブレーキ負圧Ｐbrkが判定値Ｐmimよりも大きいか否
か判別される。そして、ブレーキ負圧Ｐbrkが判定値Ｐm
imよりも大きい（Ｐbrk＞Ｐmim）ときにはサージタンク
４の負圧が負圧倍力装置１４の作動を保証する大きさに
確保された状態にあり、ブレーキ負圧制御は必要ではな
く当該制御ルーチンを終了する。When it is determined that the engine body 1 is operating at a lean air-fuel ratio and is not in the brake negative pressure control zone in step S2, the negative pressure of the surge tank 4 guarantees the operation of the negative pressure booster 14. Since the size is secured, the brake negative pressure control is not necessary and the control routine ends. When it is determined in step S2 that the brake pressure is in the brake negative pressure control zone, it is determined whether or not the negative pressure in the surge tank 4 is a negative pressure that can guarantee the operation of the negative pressure booster 14 (hereinafter referred to as "brake negative pressure"). A determination is made (step S3). That is, it is determined whether or not the brake negative pressure Pbrk detected by the negative pressure sensor 20 is larger than the determination value Pmim. Then, the brake negative pressure Pbrk is equal to the determination value Pm.
When the pressure is larger than im (Pbrk> Pmim), the negative pressure of the surge tank 4 is maintained at a level that guarantees the operation of the negative pressure booster 14, and the brake negative pressure control is not necessary and the control routine is executed. finish.
【００１７】ステップＳ３においてブレーキ負圧Ｐbrk
が判定値Ｐmimよりも小さいと判別されたときには、サ
ージタンク４内に未だ負圧が多少ある間にブレーキ負圧
を確保すべくブレーキ負圧制御を行う（ステップＳ
４）。即ち、電子制御装置２５は、ブレーキ負圧Ｐbrk
が判定値Ｐmimよりも小さい（不足している）と判別し
たときには、ターボチャージャ７のステッパモータ１１
を制御してベーン１０の開度を開側に制御する。この場
合、ブレーキ負圧を確保するために過給圧を下げると、
エンジン本体１への吸入空気量Ｑairが減少し、エンジ
ン出力が低下してトルクショックが発生する。そこで、
燃料噴射量を増量して空燃比（Ａ／Ｆ）をリッチ側に制
御してエンジン出力を増大させる。この燃料噴射は、吸
気行程で行われる。In step S3, the brake negative pressure Pbrk
Is smaller than the determination value Pmim, brake negative pressure control is performed to secure the brake negative pressure while the negative pressure still exists in the surge tank 4 (Step S).
4). That is, the electronic control unit 25 outputs the brake negative pressure Pbrk
Is smaller than the determination value Pmim (insufficient), the stepper motor 11 of the turbocharger 7 is determined.
To control the opening of the vane 10 to the open side. In this case, if the boost pressure is reduced to secure the brake negative pressure,
The intake air amount Qair to the engine body 1 decreases, the engine output decreases, and a torque shock occurs. Therefore,
The engine output is increased by increasing the fuel injection amount and controlling the air-fuel ratio (A / F) to the rich side. This fuel injection is performed in the intake stroke.
【００１８】次いで、上述の図２におけるブレーキ負圧
制御を図３のタイムチャートに基づいて説明する。この
タイムチャートは、例えば、後期噴射モード運転中にド
ライバがブレーキ操作を繰り返し負圧倍力装置の作用す
る負圧が所定負圧以下となりブレーキ負圧制御が実行さ
れ、その後解除されるまでの流れを示したものである。Next, the above-described brake negative pressure control in FIG. 2 will be described with reference to a time chart in FIG. This time chart shows, for example, the flow from the time when the driver repeatedly performs the brake operation during the latter-stage injection mode operation, the negative pressure acting on the negative pressure booster becomes equal to or lower than the predetermined negative pressure, the brake negative pressure control is executed, and then the brake negative pressure control is released. It is shown.
【００１９】先ず、図３のＡ区間では、図３（ｄ）、
（ｈ）、（ｉ）に示されるように圧縮行程中に少量の燃
料が噴射される後期噴射モード運転（リーン運転）が行
われている。このとき、空燃比（Ａ／Ｆ）が４０程度の
リーン運転であるため、図３（ｆ）に示されるようにス
ロットル弁６の開度は大に設定され燃焼室内へ供給され
る吸入空気量Ｑは多くなり（図３（ｇ））、しかも、図
３（ｂ）に示されるように過給圧が高くなるようベーン
１０の開度は閉側に制御され、排圧は高い状態（図３
（ｃ））となる。また、後期噴射モード運転（層状燃焼
運転）のときは特に排ガス中のＮＯｘを低減すべき、図
３（ｅ）に示されるように、ＥＧＲ弁１８は、略全開状
態に制御され大量の排気ガスが吸気通路２に還流され
る。First, in section A of FIG. 3, FIG.
As shown in (h) and (i), a late injection mode operation (lean operation) in which a small amount of fuel is injected during the compression stroke is performed. At this time, since the air-fuel ratio (A / F) is a lean operation of about 40, the opening degree of the throttle valve 6 is set to a large value and the amount of intake air supplied to the combustion chamber as shown in FIG. Q is increased (FIG. 3 (g)), and as shown in FIG. 3 (b), the opening of the vane 10 is controlled to the closed side so that the supercharging pressure is increased, and the exhaust pressure is high (FIG. 3 (g)). 3
(C)). Further, in the latter-stage injection mode operation (stratified combustion operation), particularly, NOx in the exhaust gas should be reduced. As shown in FIG. 3 (e), the EGR valve 18 is controlled to a substantially fully opened state and a large amount of exhaust gas is discharged. Is returned to the intake passage 2.
【００２０】その後、ドライバのブレーキ操作等により
図３（ａ）に示されるように負圧倍力装置１４の作用す
る負圧が低下、即ち、負圧センサ２０の出力が判定値以
下となった場合（図３のＢ区間）、負圧倍力装置１４の
負圧を保証すべく、図３（ｂ）に示されるようにベーン
１０の開度は開側に制御され、排圧は低くなる（図３
（ｃ））。このとき、本タイムチャートでは、ベーン１
０の開度が開側に制御されることによるエンジン本体１
の出力変化の抑制、及び確実に負圧倍力装置１４の負圧
を更に保証すべく、図３（ｄ）、（ｈ）、（ｉ）に示さ
れるように、後期噴射モード運転よりは多めの燃料が吸
気行程に噴射され空燃比がリッチ側、具体的には、スト
イキオ近傍に制御され（前期噴射モード運転）、出力と
スロットル弁６の下流の負圧が確保されるよう制御され
る。このため、図３（ｆ）に示されるように、スロット
ル弁６の開度は小に設定され、吸入空気量Ｑは少なくな
り（図３（ｇ））、また、図３（ｅ）に示されるよう
に、ＥＧＲ弁１８は全閉状態に制御され、ＥＧＲ量は徐
々に０になる。Thereafter, as shown in FIG. 3A, the negative pressure acting on the negative pressure booster 14 is reduced by the driver's brake operation or the like, that is, the output of the negative pressure sensor 20 becomes equal to or less than the judgment value. In the case (section B in FIG. 3), in order to guarantee the negative pressure of the negative pressure booster 14, the opening of the vane 10 is controlled to the open side as shown in FIG. (FIG. 3
(C)). At this time, in this time chart, vane 1
Engine body 1 due to opening degree 0 being controlled to open side
As shown in FIGS. 3D, 3H, and 3I, in order to suppress the output change and to further assure the negative pressure of the negative pressure booster 14, the output is more than the latter injection mode operation. Is injected in the intake stroke, and the air-fuel ratio is controlled to the rich side, specifically, near the stoichiometric state (first-stage injection mode operation), and the output and the negative pressure downstream of the throttle valve 6 are controlled. Therefore, as shown in FIG. 3 (f), the opening of the throttle valve 6 is set small, the intake air amount Q decreases (FIG. 3 (g)), and as shown in FIG. 3 (e). As such, the EGR valve 18 is controlled to the fully closed state, and the EGR amount gradually becomes zero.
【００２１】その後、負圧倍力装置１４の負圧が確保さ
れ、負圧センサ２０の出力が判定値を下回った場合（図
３（ａ））、図３の区間Ｃにおいて、ドライバの加速要
求等によりエンジンの運転状態が大きく変更されていな
いのであれば、再びベーン１０の開度を閉側に制御して
（図３（ｂ））、区間Ａと略同様な後期噴射モード運転
に移行される。尚、区間Ｃにおける空燃比、スロットル
開度、ＥＧＲ量、吸入空気量、噴射量、噴射時期等は区
間Ａと略同様な制御が実行されるため、説明は省略す
る。Thereafter, when the negative pressure of the negative pressure booster 14 is secured and the output of the negative pressure sensor 20 falls below the judgment value (FIG. 3A), the driver's acceleration request is made in section C of FIG. If the operating state of the engine has not been significantly changed due to, for example, the opening degree of the vane 10 is again controlled to the closed side (FIG. 3B), and the operation is shifted to the late injection mode operation substantially similar to the section A. You. Note that the air-fuel ratio, the throttle opening, the EGR amount, the intake air amount, the injection amount, the injection timing, and the like in the section C are controlled in substantially the same manner as in the section A, and the description thereof will be omitted.
【００２２】尚、本発明は、上述した実施形態に何ら限
定されるものではなく、本実施形態ではブレーキ負圧制
御においてベーン１０の開度を開側に制御する際に運転
モードを変更するように設定しているが、特に大きな出
力変化が起きない場合には、運転モードまで変更せずＡ
／Ｆの制御、点火時期の制御のみで出力変化を抑制する
ようにしてもよい。The present invention is not limited to the above-described embodiment. In this embodiment, the operation mode is changed when the opening of the vane 10 is controlled to the open side in the brake negative pressure control. However, if no large output change occurs, the operation mode is not changed and A
The output change may be suppressed only by the control of / F and the control of the ignition timing.
【００２３】また、本実施形態では、一つの判定値に基
づいて負圧センサ２０の出力がこの判定値を超えた場合
に本ブレーキ負圧制御を実行するようになっているが、
例えば、判定値を複数設けて、判定値毎に（負圧不足度
合に応じて）ベーン開度を段階的に制御するようにして
もよい。更に、本実施形態では、負圧センサ２０の出力
に基づいて本制御を開始しているが、例えば、ドライバ
のブレーキ操作を検出するブレーキスイッチや負圧セン
サ２０に代えて所定負圧でＯＮ−ＯＦＦ信号を出力する
負圧スイッチ、或いは、エンジンの運転状態による吸気
通路２内の負圧及びブレーキ操作回数等から負圧倍力装
置１４の負圧を推定し、その推定結果に基づいて本制御
を開始するようにしてもよい。In the present embodiment, the brake negative pressure control is executed when the output of the negative pressure sensor 20 exceeds this determination value based on one determination value.
For example, a plurality of determination values may be provided, and the vane opening may be controlled in a stepwise manner for each determination value (according to the degree of insufficient negative pressure). Further, in the present embodiment, the present control is started based on the output of the negative pressure sensor 20. However, for example, instead of the brake switch for detecting the driver's braking operation or the negative pressure sensor 20, ON- A negative pressure switch that outputs an OFF signal, or a negative pressure of the negative pressure booster 14 is estimated from a negative pressure in the intake passage 2 and the number of brake operations depending on an operation state of the engine, and the main control is performed based on the estimation result. May be started.
【００２４】また、本実施形態では、可変ターボチャー
ジャ付筒内噴射型内燃機関を前提として説明している
が、吸気通路内の負圧を利用する負圧倍力装置を有し、
ベーン１０を持たない通常のターボチャージャ等の過給
手段付希薄燃焼内燃機関にも本制御を適用でき、この場
合は、ウエストゲートバルブの作動を制御して過給圧を
制御すればよい。Further, in the present embodiment, the description has been made on the premise that the cylinder injection type internal combustion engine is equipped with a variable turbocharger, but a negative pressure booster utilizing a negative pressure in the intake passage is provided.
This control can also be applied to a lean-burn internal combustion engine with supercharging means such as a normal turbocharger without the vane 10, and in this case, the supercharging pressure may be controlled by controlling the operation of the wastegate valve.
【００２５】[0025]
【発明の効果】本発明によれば、リーン運転時に負圧倍
力装置に供給するブレーキ負圧が不足すると過給圧を下
げることで、前記負圧倍力装置への安定した負圧を確保
し、当該負圧倍力装置の作動を保証することができる。According to the present invention, when the brake negative pressure supplied to the vacuum booster during lean operation is insufficient, the supercharging pressure is reduced to secure a stable vacuum to the vacuum booster. In addition, the operation of the negative pressure booster can be guaranteed.
【図１】本発明に係る過給機を搭載した希薄燃焼内燃機
関の概略構成を示すブロック図である。FIG. 1 is a block diagram showing a schematic configuration of a lean burn internal combustion engine equipped with a supercharger according to the present invention.
【図２】図１に示す希薄燃焼内燃機関の制御手順の一例
を示すフローチャートである。FIG. 2 is a flowchart showing an example of a control procedure of the lean burn internal combustion engine shown in FIG.
【図３】図１に示す希薄燃焼内燃機関のブレーキ負圧制
御におけるタイムチャートを示す図である。FIG. 3 is a diagram showing a time chart in brake negative pressure control of the lean burn internal combustion engine shown in FIG. 1;
１ エンジン本体（希薄燃焼内燃機関） ２ 吸気通路 ３ 排気通路 ４ サージタンク ６ スロットル弁（吸入空気量調整手段） ７ 可変ターボチャージャ（過給手段） １０ ベーン（過給圧調整手段） １４ 負圧倍力装置 １８ ＥＧＲ弁 ２０ 負圧センサ（負圧低下検知手段） ２５ 電子制御装置 DESCRIPTION OF SYMBOLS 1 Engine main body (lean combustion internal combustion engine) 2 Intake passage 3 Exhaust passage 4 Surge tank 6 Throttle valve (intake air amount adjusting means) 7 Variable turbocharger (supercharging means) 10 Vane (supercharging pressure adjusting means) 14 Negative pressure multiplication Power device 18 EGR valve 20 Negative pressure sensor (negative pressure drop detecting means) 25 Electronic control unit
フロントページの続き Ｆターム(参考） 3G005 DA01 EA04 EA15 EA16 FA21 GA04 GC08 GD03 GD13 GE01 HA00 HA05 HA12 HA19 JA06 JA24 JA26 JB07 JB09 3G084 AA04 BA05 BA07 BA13 BA15 BA20 CA06 DA15 FA06 FA07 FA10 FA11 FA20 FA33 3G092 AA01 AA06 AA09 AA17 AA18 BA02 BA06 BA09 BB01 BB06 DB03 DC12 DE03Y DF02 DG08 EA06 EA07 EC01 FA34 GA05 GA06 HA01Z HA05Z HA06X HA06Z HA16X HA16Z HC01Z HD09X HE01Z HE08Z HF08Z HF21Z HF26Z 3G093 AB02 BA00 CA06 CA07 DA01 DA03 DA05 DA06 DA09 DB15 EA05 EA06 EA11 EA13 EA14 EB04 EC02 EC05 FA04 FB02Continued on the front page F term (reference) 3G005 DA01 EA04 EA15 EA16 FA21 GA04 GC08 GD03 GD13 GE01 HA00 HA05 HA12 HA19 JA06 JA24 JA26 JB07 JB09 3G084 AA04 BA05 BA07 BA13 BA15 BA20 CA06 DA15 FA06 FA07 FA10 FA11 FA20 FA09 A09AA A18A BA02 BA06 BA09 BB01 BB06 DB03 DC12 DE03Y DF02 DG08 EA06 EA07 EC01 FA34 GA05 GA06 HA01Z HA05Z HA06X HA06Z HA16X HA16Z HC01Z HD09X HE01Z HE08Z HF08Z HF21Z HF26Z 3G093 AB02 BA00 CA06 CA05 DA03 DA03 DA03 DA03 DA03 DA03 DA03
Claims (1)
調整手段と、 前記吸入空気量調整手段の下流側から取り出される負圧
を利用してブレーキペダルの踏力を増大させる負圧倍力
装置と、 前記内燃機関本体へ供給される吸気を過給する過給手段
と、 前記過給手段により得られる過給圧を調整可能な過給圧
調整手段と、 前記負圧倍力装置に作用する負圧の低下を検出又は推定
する負圧低下検知手段と、 前記負圧検知手段により前記負圧倍力装置の負圧低下が
検出又は推定された場合、前記過給圧が低過給圧側にな
るように前記過給圧調整手段を制御する制御手段とを備
えたことを特徴とする希薄燃焼内燃機関。1. An internal combustion engine body capable of lean combustion, intake air amount adjusting means for adjusting an intake air amount to the internal combustion engine body, and a negative pressure taken from a downstream side of the intake air amount adjusting means. Negative pressure booster for increasing the depression force of the brake pedal, supercharging means for supercharging intake air supplied to the internal combustion engine body, and supercharging pressure capable of adjusting the supercharging pressure obtained by the supercharging means Adjusting means; negative pressure drop detecting means for detecting or estimating a decrease in negative pressure acting on the negative pressure booster; and a negative pressure drop of the negative pressure booster detected or estimated by the negative pressure detecting means. And a control means for controlling the supercharging pressure adjusting means so that the supercharging pressure is on the low supercharging pressure side.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11086041A JP2000282906A (en) | 1999-03-29 | 1999-03-29 | Lean combustion internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11086041A JP2000282906A (en) | 1999-03-29 | 1999-03-29 | Lean combustion internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000282906A true JP2000282906A (en) | 2000-10-10 |
Family
ID=13875605
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11086041A Pending JP2000282906A (en) | 1999-03-29 | 1999-03-29 | Lean combustion internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000282906A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002332879A (en) * | 2001-05-01 | 2002-11-22 | Hino Motors Ltd | Egr device |
| JP2010116896A (en) * | 2008-11-14 | 2010-05-27 | Mitsubishi Electric Corp | Control device for internal combustion engine |
| KR101294547B1 (en) * | 2007-06-05 | 2013-08-07 | 현대자동차주식회사 | a brake pressure descent apparatus using gasoline turbo charger engine pressure |
| CN103899412A (en) * | 2012-12-27 | 2014-07-02 | 现代自动车株式会社 | Brake negative pressure generating device for vehicle |
| KR101448777B1 (en) * | 2013-02-27 | 2014-10-13 | 현대자동차 주식회사 | A negative pressure forming device for brake of vehicle |
| KR101887965B1 (en) * | 2016-12-12 | 2018-08-13 | 현대오트론 주식회사 | A Negative Pressure Forming Apparatus Using the Differential Pressure Valve |
-
1999
- 1999-03-29 JP JP11086041A patent/JP2000282906A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002332879A (en) * | 2001-05-01 | 2002-11-22 | Hino Motors Ltd | Egr device |
| KR101294547B1 (en) * | 2007-06-05 | 2013-08-07 | 현대자동차주식회사 | a brake pressure descent apparatus using gasoline turbo charger engine pressure |
| JP2010116896A (en) * | 2008-11-14 | 2010-05-27 | Mitsubishi Electric Corp | Control device for internal combustion engine |
| CN103899412A (en) * | 2012-12-27 | 2014-07-02 | 现代自动车株式会社 | Brake negative pressure generating device for vehicle |
| KR101438624B1 (en) * | 2012-12-27 | 2014-09-15 | 현대자동차 주식회사 | A negative pressure forming device for vehicle |
| US9133760B2 (en) | 2012-12-27 | 2015-09-15 | Hyundai Motor Company | Brake negative pressure generating device for vehicle |
| KR101448777B1 (en) * | 2013-02-27 | 2014-10-13 | 현대자동차 주식회사 | A negative pressure forming device for brake of vehicle |
| US9187073B2 (en) | 2013-02-27 | 2015-11-17 | Hyundai Motor Company | Negative pressure forming device for brake of vehicle |
| KR101887965B1 (en) * | 2016-12-12 | 2018-08-13 | 현대오트론 주식회사 | A Negative Pressure Forming Apparatus Using the Differential Pressure Valve |
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