JPH0565705B2 - - Google Patents
Info
- Publication number
- JPH0565705B2 JPH0565705B2 JP59204133A JP20413384A JPH0565705B2 JP H0565705 B2 JPH0565705 B2 JP H0565705B2 JP 59204133 A JP59204133 A JP 59204133A JP 20413384 A JP20413384 A JP 20413384A JP H0565705 B2 JPH0565705 B2 JP H0565705B2
- Authority
- JP
- Japan
- Prior art keywords
- intake
- fuel
- fuel injection
- valve
- control valve
- 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
- 239000000446 fuel Substances 0.000 claims description 110
- 238000002347 injection Methods 0.000 claims description 66
- 239000007924 injection Substances 0.000 claims description 66
- 238000002485 combustion reaction Methods 0.000 claims description 14
- 230000009977 dual effect Effects 0.000 claims description 3
- 238000013517 stratification Methods 0.000 description 13
- 239000000203 mixture Substances 0.000 description 12
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
Landscapes
- 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
本発明は複吸気弁エンジンにおける燃料噴射制
御の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to improvements in fuel injection control in dual intake valve engines.
従来技術
従来、燃費の向上および排気ガスエミツシヨン
の低減を図るため、第１吸気ポートを例えばヘリ
カル状、第２吸気ポートをストレート状とし、第
２吸気ポートに燃料噴射弁を設けた構成が提案さ
れている（例えば、本発明者らに係る特願昭58−
228399号参照）。ストレート状第２吸気ポートに
は吸気制御弁が設けられ、この吸気制御弁は機関
低回転低負荷域では閉となる。吸気制御弁が閉で
あるとき、ストレート状第２吸気ポートより燃料
が燃焼室中央部に向け噴射され、一方ヘリカル状
第１吸気ポートから空気がシリンダ内周に沿つて
旋回するように導入される。その結果、シリンダ
内はリーン（例えば空燃比25−30）であるが燃焼
室中央の点火栓近傍は燃焼に最適な理論空燃比
（14.0程度）近くになるという成層化が達成され
る。従つて、全体としては空燃比は超希薄である
にも係わらず燃焼を安定に行うことができ、
NOx成分排出量の低減及び燃料消費率の向上を
図ることができる。ところがこの先願技術では吸
気制御弁が閉鎖する低回転低負荷域における成層
が強すぎかえつてNOx排出量が増大するという
問題を本発明者らは発見した。Prior Art Conventionally, in order to improve fuel efficiency and reduce exhaust gas emissions, a configuration has been proposed in which the first intake port is, for example, helical, the second intake port is straight, and the second intake port is provided with a fuel injection valve. (For example, the patent application filed in 1982 by the present inventors)
(See No. 228399). The straight second intake port is provided with an intake control valve, and this intake control valve is closed in a low engine speed and low load range. When the intake control valve is closed, fuel is injected toward the center of the combustion chamber from the straight second intake port, while air is introduced from the helical first intake port so as to swirl along the inner circumference of the cylinder. . As a result, stratification is achieved in which the inside of the cylinder is lean (for example, air-fuel ratio 25-30), but near the ignition plug in the center of the combustion chamber is close to the stoichiometric air-fuel ratio (approximately 14.0), which is optimal for combustion. Therefore, even though the air-fuel ratio is extremely lean, combustion can be carried out stably.
It is possible to reduce NOx component emissions and improve fuel consumption rate. However, in this prior art, the present inventors discovered a problem in that stratification is too strong in the low-speed, low-load range where the intake control valve is closed, resulting in an increase in NOx emissions.
発明が解決しようとする問題点
本発明はこの先願技術の問題点を解決するため
なされたものであり、吸気制御弁が閉じている低
回転低負荷域における成層度を最適にコントロー
ルすることができる複吸気弁エンジンを提供する
ことにある。Problems to be Solved by the Invention The present invention has been made to solve the problems of the prior art, and can optimally control the degree of stratification in the low rotation and low load range when the intake control valve is closed. The object of the present invention is to provide a dual intake valve engine.
問題点を解決するための手段
本発明によれば吸気制御弁が設けられるストレ
ート状の第２吸気ポート内の燃料噴射弁に加えて
ヘリカル状の第１吸気ポート内にも燃料噴射弁が
設けられ、吸気弁が閉塞する低回転低負荷域にお
いてもこれらの双方の燃料噴射弁は作動され、そ
の噴射量の割合はエンジン運転条件に応じて制御
される。Means for Solving the Problems According to the present invention, in addition to the fuel injection valve in the straight-shaped second intake port in which the intake control valve is provided, a fuel injection valve is also provided in the helical-shaped first intake port. Both fuel injection valves are operated even in a low rotation and low load range where the intake valve is closed, and the ratio of their injection amounts is controlled according to engine operating conditions.
作 用
低回転低負荷域において吸気制御弁は閉鎖さ
れ、ストレート状第２ポートからの燃料は燃焼室
中央に向けて噴射され、一方ヘリカル状第１ポー
トからは混合気がシリンダ内に旋回導入され、点
火栓付近の濃い混合気部分とシリンダ内の薄い混
合気部分とにより成層化される。者等に、双方の
ポートの燃料噴射弁より燃料が噴射されることか
ら、燃料噴射弁の燃料噴射比率を変えることによ
つて成層度がコントロールされる。Operation In the low-speed, low-load range, the intake control valve is closed, and the fuel from the straight-shaped second port is injected toward the center of the combustion chamber, while the air-fuel mixture is swirled into the cylinder from the helical-shaped first port. , the mixture is stratified by a rich mixture near the spark plug and a lean mixture inside the cylinder. Since fuel is injected from the fuel injection valves of both ports, the degree of stratification is controlled by changing the fuel injection ratio of the fuel injection valves.
尚、本願構成は双方のポートに燃料噴射弁を設
けたことで構成としては本発明者らに係る特願昭
58−237961と類似している。しかし、この先願は
吸気制御弁の開とされる高回転・高負荷時に双方
の燃料噴射弁を作動させているが、吸気制御弁の
閉とされる低回転・低負荷時はストレートポート
の燃料噴射弁のみ作動され、本願と違つて双方の
燃料噴射弁は作動されない。 The configuration of the present application is similar to that of the patent application filed by the present inventors since fuel injection valves are provided at both ports.
Similar to 58−237961. However, in this prior application, both fuel injection valves are operated at high speeds and high loads when the intake control valve is open, but when the intake control valve is closed at low speeds and low loads, the straight port is injected. Only the injection valve is operated, and unlike the present application, both fuel injection valves are not operated.
実施例 以下図示実施例により本発明を説明する。Example The present invention will be explained below with reference to illustrated embodiments.
第３図は本発明の一実施例構成を示す。図にお
いて、吸気通路１は途中で第１吸気ポート２と第
２吸気ポート３とに分岐して燃焼室１００に連通
し、第１吸気ポート２の燃焼室側には第１吸気弁
４、第２吸気ポート３の燃焼室側には第２吸気弁
５がそれぞれ設けられる。第１吸気ポート２はヘ
リカル状をなし、燃焼室１００内にスワールを生
成させるようになつている。一方第２吸気ポート
３は、燃焼室１００の上部中央に設けられた点火
プラグ６の近傍に開口し、ストレート状を呈す
る。 FIG. 3 shows the configuration of an embodiment of the present invention. In the figure, an intake passage 1 branches into a first intake port 2 and a second intake port 3 in the middle and communicates with a combustion chamber 100. A second intake valve 5 is provided on the combustion chamber side of the two intake ports 3, respectively. The first intake port 2 has a helical shape and is designed to generate a swirl within the combustion chamber 100. On the other hand, the second intake port 3 opens near the spark plug 6 provided in the upper center of the combustion chamber 100, and has a straight shape.
第１および第２吸気ポート２，３の分岐部分に
は、ストレート状第２吸気ポート３を開閉可能な
吸気制御弁７が設けられる。吸気制御弁７は後述
するアクチユエータ１０により開閉駆動され、エ
ンジンを低回転低負荷で運転する時、第２吸気ポ
ート３を閉塞し、エンジンを高回転高負荷で運転
する時、第２吸気ポート３を開放する。 An intake control valve 7 that can open and close the straight second intake port 3 is provided at a branch portion of the first and second intake ports 2 and 3. The intake control valve 7 is driven to open and close by an actuator 10, which will be described later, and closes the second intake port 3 when the engine is operated at low rotation and low load, and closes the second intake port 3 when the engine is operated at high rotation and high load. to open.
アクチユエータ１０は、シエル１１内をダイヤ
フラム１２により大気室１３と変圧室１４に区画
され、変圧室１４内に大気圧もしくは負圧を選択
的に導入可能にして構成される。ダイヤフラム１
２にはロツド１５が固定され、このロツド１５
は、その先端に形成された長穴１６を吸気制御弁
７に設けられたピン１７に係合させることによ
り、吸気制御弁７に連結される。変圧室１４内に
はダイヤフラム１２を付勢可能なばね１８が設け
られる。変圧室１４内に負圧が導かれると、ダイ
ヤフラム１２はばね１８を圧縮させて変位し、こ
れによりロツド１５が右行して吸気制御弁７は第
２吸気ポート３を閉塞する（図中、実線で示す位
置）。逆に変圧室１４内が大気圧となつた場合、
ダイヤフラム１２はばね１８に押圧されて左行
し、吸気制御弁７はロツド１５を介して第２吸気
ポート３を開放する（図中、鎖線で示す位置）。 The actuator 10 is configured such that a shell 11 is divided into an atmospheric chamber 13 and a variable pressure chamber 14 by a diaphragm 12, and atmospheric pressure or negative pressure can be selectively introduced into the variable pressure chamber 14. Diaphragm 1
A rod 15 is fixed to 2, and this rod 15
is connected to the intake control valve 7 by engaging a long hole 16 formed at its tip with a pin 17 provided on the intake control valve 7. A spring 18 capable of biasing the diaphragm 12 is provided within the variable pressure chamber 14 . When negative pressure is introduced into the variable pressure chamber 14, the diaphragm 12 compresses the spring 18 and is displaced, causing the rod 15 to move to the right and the intake control valve 7 to close the second intake port 3 (in the figure, position shown by the solid line). Conversely, if the inside of the pressure changing chamber 14 becomes atmospheric pressure,
The diaphragm 12 is pushed by the spring 18 and moves to the left, and the intake control valve 7 opens the second intake port 3 via the rod 15 (the position shown by the chain line in the figure).
負圧切換弁（VSV）２０はアクチユエータ１
０の変圧室１４に負圧もしくは大気圧を導くもの
である。すなわち、負圧切換弁２０は第１導管２
１を介して変圧室１４に常時連通しており、この
第１導管２１を、空気フイルタ３０に開放された
第２導管２２、またはバキユームタンク２３に連
通する第３導管２４に連通されるようになつてい
る。負圧切換弁２０の弁体の切換は、後述の制御
回路２５によつて行なわれる。一方、バキユーム
タンク２３は、吸気通路１のスロツトル弁２７よ
りも下流側に、逆止弁２８を介して接続され、エ
ンジンの運転中は常時負圧が保持されるようにな
つている。 Negative pressure switching valve (VSV) 20 is actuator 1
This is to introduce negative pressure or atmospheric pressure into the variable pressure chamber 14 at zero. That is, the negative pressure switching valve 20 is connected to the first conduit 2
1, and the first conduit 21 is connected to a second conduit 22 which is open to the air filter 30, or a third conduit 24 which communicates with the vacuum tank 23. It's getting old. Switching of the valve body of the negative pressure switching valve 20 is performed by a control circuit 25, which will be described later. On the other hand, the vacuum tank 23 is connected to the intake passage 1 downstream of the throttle valve 27 via a check valve 28, so that negative pressure is maintained at all times during engine operation.
第１燃料噴射弁３１は第１吸気ポート２の途中
に配設され、第２燃料噴射弁３２は第２吸気ポー
ト３の途中であつて吸気制御弁７よりも下流側に
設けられる。これらの燃料噴射弁３１，３２は、
それぞれ後述のように制御回路２５によつて制御
される。 The first fuel injection valve 31 is disposed in the middle of the first intake port 2, and the second fuel injection valve 32 is disposed in the middle of the second intake port 3 and downstream of the intake control valve 7. These fuel injection valves 31 and 32 are
Each is controlled by a control circuit 25 as described later.
制御回路２５は、マイクロプロセツサ（MPU）
３４と、Ａ／Ｄコンバータ３５と、入力インター
フエイス３６と、出力インターフエイス３７と、
タイミング制御回路３８を備え、これらはバス３
９によつて相互に結線される。入力インターフエ
イス３６にはエンジンのクランク軸１０１の回転
パルス（クランク角パルス）を検知するクランク
角センサ４０が結線され、エンジン回転数を知
り、更にはクランク角毎の割込ルーチンのトリガ
として利用される。Ａ／Ｄコンバータ３５はスロ
ツトル弁２７の下流の吸気管圧力を知るための圧
力センサ４１、及びスロツトル弁２７を通過する
吸入空気量を知るためのエアーフローセンサ４２
に接続され、これらのセンサからのアナログ信号
がMPU３４の指令に応じてデジタル化される。
出力インターフエイス３７は第１噴射弁制御回路
４４、第２噴射弁制御回路４６を介して夫々の燃
料噴射弁３１，３２に接続されると共に、吸気制
御弁制御回路４８を介して負圧切替弁２０に接続
される。 The control circuit 25 is a microprocessor (MPU)
34, an A/D converter 35, an input interface 36, an output interface 37,
A timing control circuit 38 is provided, and these are connected to the bus 3.
9 are interconnected. A crank angle sensor 40 that detects rotation pulses (crank angle pulses) of the engine crankshaft 101 is connected to the input interface 36, and is used to know the engine rotation speed and furthermore to be used as a trigger for an interrupt routine for each crank angle. Ru. The A/D converter 35 includes a pressure sensor 41 for determining the intake pipe pressure downstream of the throttle valve 27, and an air flow sensor 42 for determining the amount of intake air passing through the throttle valve 27.
The analog signals from these sensors are digitized according to commands from the MPU 34.
The output interface 37 is connected to the respective fuel injection valves 31 and 32 via a first injection valve control circuit 44 and a second injection valve control circuit 46, and is connected to the negative pressure switching valve via an intake control valve control circuit 48. 20.
MPU３４はメモリ（図示せず）を備え、本発
明に従がつた燃料噴射弁３１，３２及び吸気制御
弁７の制御を行うためのプログラムが格納されて
いる。以下そのプログラムをフローチヤートによ
つて説明する。またこのフローチヤートの説明に
よつて本発明装置の作動も明らかになろう。 The MPU 34 includes a memory (not shown), and stores a program for controlling the fuel injection valves 31, 32 and the intake control valve 7 according to the present invention. The program will be explained below using a flowchart. The operation of the apparatus of the present invention will also become clear through the explanation of this flowchart.
第２図は吸気制御弁７の制御フローチヤートで
あつて、200のステツプよりこのルーチンが実行
される。このルーチンは所定時間毎に実行される
時間割込みルーチンとすることができる。202の
ステツプでMPU３４はＡ／Ｄコンバータ３５に
圧力センサ４１からのデータのＡ／Ｄ変換指令を
出し、吸気管圧力PBのデータがロードされる。
204のステツプではその実測される吸気管圧力PB
が所定値以上かどうか判定される。吸気管圧力が
所定値より高いとき（Yes）はスロツトル弁２７
の開度が大きい高負荷時と判定され、206に進み
出力インターフエイス３７は制御回路４８を介し
負圧切替弁２０に消磁信号を出す。そのため同切
替弁２０は白抜きのポート位置をとり、アクチユ
エータ１０の変圧室１４に大気圧が作用し、ばね
１８の力によつてダイヤフラム１２は左行し、吸
気制御弁７は破線の如く全開位置する。次の208
のステツプでフラグｆが０とされる。このフラグ
は吸気制御弁７が開か閉かを示すフラグである。 FIG. 2 is a control flowchart of the intake control valve 7, and this routine is executed from 200 steps. This routine may be a time interrupt routine that is executed at predetermined intervals. At step 202, the MPU 34 issues an A/D conversion command for the data from the pressure sensor 41 to the A/D converter 35, and the data of the intake pipe pressure P B is loaded.
In step 204, the actually measured intake pipe pressure P B
It is determined whether or not is greater than or equal to a predetermined value. When the intake pipe pressure is higher than the predetermined value (Yes), the throttle valve 27
It is determined that the load is high, and the process proceeds to step 206, where the output interface 37 outputs a degaussing signal to the negative pressure switching valve 20 via the control circuit 48. Therefore, the switching valve 20 assumes the white port position, atmospheric pressure acts on the variable pressure chamber 14 of the actuator 10, the diaphragm 12 moves to the left due to the force of the spring 18, and the intake control valve 7 is fully opened as shown by the broken line. To position. next 208
The flag f is set to 0 in step . This flag is a flag indicating whether the intake control valve 7 is open or closed.
204で吸気管圧力が所定値より低いとき（No）
は低負荷時と判断され210に進み制御回路４８よ
り負圧切替弁２０の励磁信号が出され、同切替弁
２０は黒のポート位置をとり、吸気管負圧がアク
チユエータ１０の変圧室１４に伝達される。その
ため、ダイヤフラム１２はばね１８に抗して右行
く吸気制御弁７は実線の全閉位置をとる。212は
フラグｆのセツトを示す。尚、説明上省略したが
制御弁７の駆動条件として機関回転数の要因をと
り入れることができる。 When the intake pipe pressure is lower than the specified value in 204 (No)
It is determined that the load is low, and the process proceeds to 210, where the control circuit 48 outputs an excitation signal for the negative pressure switching valve 20, and the switching valve 20 assumes the black port position, and the intake pipe negative pressure is transferred to the variable pressure chamber 14 of the actuator 10. communicated. Therefore, the diaphragm 12 resists the spring 18, and the right-going intake control valve 7 assumes the fully closed position shown by the solid line. 212 indicates the setting of flag f. Incidentally, although omitted for the sake of explanation, the engine speed factor can be incorporated as a drive condition for the control valve 7.
第１図は燃料噴射制御ルーチンであつて、300
はそのルーチンの開始を示し、クランク角センサ
４０からの所定のスランク角毎（例えば30°毎）
の信号によつて割込みに入る。302のステツプで
は運転条件（例えば回転数Ｎ、負荷相当値として
の回転数−吸入空気量比Ｑ／Ｎ）に応じた燃料噴
射時間τの計算ルーチンを示す。このルーチン自
体は周知でありまた本発明の特徴部分ではないか
ら簡略化して示すが、所定の空燃比が得られるよ
うにＮ、Ｑ／Ｎに応じた燃料噴射時間のマツプが
メモリ内にあり、実測されたＮ、Ｑ／Ｎに対応す
る燃料噴射時間τが302のステツプで計算される。
そのようなマツプとしては例えば第４図のように
模式的に表わすことができ、低回転・低負荷域で
の25位のスーパーリーンから高回転・高負荷域で
の12.5位のややリツチまでの設定空燃比範囲をも
つている。 Figure 1 shows the fuel injection control routine.
indicates the start of the routine, and every predetermined crank angle from the crank angle sensor 40 (for example, every 30 degrees)
An interrupt is entered by the signal. Step 302 shows a calculation routine for the fuel injection time τ according to the operating conditions (for example, the rotational speed N and the rotational speed-intake air amount ratio Q/N as a load equivalent value). This routine itself is well known and is not a characteristic part of the present invention, so it will be shown in a simplified manner. However, in order to obtain a predetermined air-fuel ratio, a map of fuel injection times according to N and Q/N is stored in memory. The fuel injection time τ corresponding to the actually measured N and Q/N is calculated in step 302.
Such a map can be schematically represented, for example, as shown in Figure 4, ranging from super lean at 25th place in the low rotation/low load range to slightly rich at 12.5 in the high rotation/high load range. It has a set air-fuel ratio range.
第１図で、次の304のステツプではフラグｆが
１かどうか、即ち、吸気制御弁７は閉じでいるか
どうかが判定される。ｆ＝０の場合は吸気制御弁
７は開であり、このときは306に進み、燃料分配
係数αを0.5に設定する。この係数αは1.0のとき
は第１の燃料噴射弁３１から全量の燃料が噴射さ
れ、０のときは逆に第２の燃料噴射弁３２から全
量の燃料が噴射されることを意味し、1.0と０の
中間の値ではαに応じた比率で夫々の燃料噴射弁
３１，３２から燃料が噴射される。308ではαに
τを乗算したものとして第１の燃料噴射弁３１の
噴射パルスの開時間（パルス幅）τ1が設定され、
301では１−αにτを乗算したものとして第２の
燃料噴射弁３２の噴射パルスの開時間τ2が設定さ
れる。前述のようにαは306のステツプで0.5に設
定されているから吸気制御弁７が開となることの
高負荷運転時は双方の燃料噴射弁３１，３２より
燃料噴射量は均等化される。 In FIG. 1, in the next step 304, it is determined whether the flag f is 1, that is, whether the intake control valve 7 is closed. When f=0, the intake control valve 7 is open, and in this case, the process proceeds to 306, where the fuel distribution coefficient α is set to 0.5. When this coefficient α is 1.0, it means that the entire amount of fuel is injected from the first fuel injection valve 31, and when it is 0, it means that the entire amount of fuel is injected from the second fuel injection valve 32. At a value intermediate between and 0, fuel is injected from each of the fuel injection valves 31 and 32 at a ratio according to α. In 308, the opening time (pulse width) τ 1 of the injection pulse of the first fuel injection valve 31 is set as α multiplied by τ,
In step 301, the opening time τ 2 of the injection pulse of the second fuel injection valve 32 is set as 1−α multiplied by τ. As mentioned above, α is set to 0.5 in step 306, so during high load operation when the intake control valve 7 is open, the fuel injection amounts from both fuel injection valves 31 and 32 are equalized.
312のステツプでは第１の燃料噴射弁３１から
の燃料噴射を実行すべきクランク角θ1が演算さ
れ、314のステツプでは第２の燃料噴射弁３２か
らの燃料噴射を実行すべきクランク角θ2が計算さ
れ、316ではこれらのτ1、τ2、θ1、θ2がMPU３４
のレジスタにセツトされる。周知のようにタイミ
ング制御回路３８はθ1、θ2のクランクアングルか
ら燃料噴射弁３１，３２が燃料噴射をτ1、τ2の間
実行するように出力インターフエイス３７より
夫々の制御回路４４，４６を駆動することにな
る。 At step 312, the crank angle θ 1 at which fuel injection from the first fuel injection valve 31 should be executed is calculated, and at step 314, the crank angle θ 2 at which fuel injection from the second fuel injection valve 32 should be executed is calculated. are calculated, and in 316, these τ 1 , τ 2 , θ 1 , θ 2 are calculated by MPU 34
is set in the register. As is well known, the timing control circuit 38 controls the respective control circuits 44 and 44 from the output interface 37 so that the fuel injection valves 31 and 32 inject fuel from the crank angles θ 1 and θ 2 for the durations τ 1 and τ 2 . 46.
以上述べた吸気制御弁７が開となる高負荷運転
時には第１の燃料噴射弁３１及び第２の燃料噴射
弁３２から均等量の燃料が噴射される。従つて、
第５図のように燃料室１００内には夫々の燃料噴
射弁３１，３２からの燃料に基づく均等な空燃比
混合気がA1、A2のように形成される。吸気制御
弁７が開となるこの運転時は成層作用は得られな
いが第１ポート２、第２ポート３より混合気が導
入されることによつて燃料室１００内の混合気は
均一となり空燃比が小さい（12.5程度）こととあ
いまつて高トルク、高出力を得ることができる。 During high-load operation when the intake control valve 7 described above is open, equal amounts of fuel are injected from the first fuel injection valve 31 and the second fuel injection valve 32. Therefore,
As shown in FIG. 5, air-fuel mixtures with equal air-fuel ratios are formed in the fuel chamber 100 as A 1 and A 2 based on the fuel from the respective fuel injection valves 31 and 32. During this operation when the intake control valve 7 is open, a stratification effect cannot be obtained, but as the air-fuel mixture is introduced from the first port 2 and the second port 3, the air-fuel mixture in the fuel chamber 100 becomes homogeneous and becomes empty. Combined with the low fuel ratio (about 12.5), it is possible to obtain high torque and high output.
第１図の304でｆ＝１であるとき即ち吸気制御
弁７が閉とされる低負荷時は318のステツプに進
み、燃料分配比αはエンジン運転条件、即ち回転
数Ｎ及び負荷相当値である吸入空気量−回転数比
Ｑ／Ｎ、に応じて決められる。以下のステツプ
308−316は同様であり、αの比率で分配された燃
料が噴射時間τ1、τ2をもつて第１の燃料噴射弁３
１、第２の燃料噴射弁３２より夫々θ1、θ2のクラ
ンク角で噴射される。 When f = 1 at 304 in Fig. 1, that is, when the intake control valve 7 is closed and the load is low, the process proceeds to step 318, and the fuel distribution ratio α is determined based on the engine operating conditions, that is, the rotation speed N and the load equivalent value. It is determined according to a certain intake air amount-rotational speed ratio Q/N. Steps below
308-316 are similar, and the fuel distributed at the ratio of α is injected into the first fuel injector 3 with injection times τ 1 and τ 2 .
1. The fuel is injected from the second fuel injection valve 32 at crank angles of θ 1 and θ 2 , respectively.
吸気制御弁７が閉鎖される低負荷運転において
は、第６図に示すようにヘリカル状第１ポート２
からの空気は第１燃料噴射弁３１からの燃料と共
に混合気となつて矢印Ｓのようにスワールをなし
てシリンダ内に導入される。一方ストレート状の
第２ポート３内の第２燃料噴射弁３２からは燃料
が燃料室１００の中央に向け噴射され、その結
果、点火栓６の周囲B2の部分の混合気はスワー
ルポート２からのスワールＳによつて形成される
シリンダ内の混合気B1より濃く、強い成層が行
われる。即ち、全体としては空燃比は超希薄（例
えば25.0）であつても点火栓６の付近は理論空燃
比（14.0）程度となり、このような成層作用によ
つて点火燃焼を図ることができる。第１燃料噴射
弁３１、第２の燃料噴射弁からの燃料分配を決め
る係数αは、前述のように回転数Ｎ、吸入空気量
−回転数比Ｑ／Ｎなどの運転条件に応じて変化さ
せるが、傾向としては、低回転・低負荷側ではα
は０に近く、ほとんどの燃料がストレートポート
側の第２燃料噴射弁３２よ噴射され、回転数及び
負荷が大きくなるにつれて第２燃料噴射弁３２よ
りの噴射量を減少し第１燃料噴射弁３１よりの噴
射量を増大させ吸気制御弁７が閉から開に切替る
点では0.5とするように変えることになる。これ
を極度に模式化して示すと第７図のようになる。
ストレート状の第２ポート側第２燃料噴射弁３２
からの噴射量が多い程成層が良く行われ、総合的
にはよりリーン化しても燃焼させることができ
る。しかしながら、成層度を大きくとりすぎる
と、かえつてNOxの排出量が増加する問題があ
る。そこで回転数および負荷によつて燃料の分配
比αを変えることによつて成層度を変えることで
NOxを抑制することができる。即ち第８図で成
層度を大小と２種類選択した場合の空燃比に対す
るNOx排出量変化をモデル的に示す。成層度が
大きい方がNOx排出量がピークとなる空燃比が
希薄側に移り、上記の現象を示している。 During low load operation when the intake control valve 7 is closed, the helical first port 2 is closed as shown in FIG.
The air from the first fuel injection valve 31 forms a mixture with the fuel from the first fuel injection valve 31, and is introduced into the cylinder in a swirl as shown by an arrow S. On the other hand, fuel is injected from the second fuel injection valve 32 in the straight-shaped second port 3 toward the center of the fuel chamber 100, and as a result, the air-fuel mixture in the area B 2 around the spark plug 6 flows from the swirl port 2. The air-fuel mixture B1 in the cylinder formed by the swirl S is richer and strongly stratified. That is, even if the overall air-fuel ratio is extremely lean (for example, 25.0), the area near the spark plug 6 is about the stoichiometric air-fuel ratio (14.0), and ignition combustion can be achieved by such a stratification effect. As described above, the coefficient α that determines the fuel distribution from the first fuel injection valve 31 and the second fuel injection valve is changed depending on the operating conditions such as the rotation speed N and the intake air amount-rotation speed ratio Q/N. However, the tendency is that at low rotation speeds and low loads, α
is close to 0, and most of the fuel is injected through the second fuel injection valve 32 on the straight port side, and as the rotation speed and load increase, the injection amount from the second fuel injection valve 32 is reduced and The injection amount is increased to 0.5 at the point where the intake control valve 7 switches from closed to open. This is illustrated in an extremely schematic manner as shown in FIG.
Straight second port side second fuel injection valve 32
The larger the amount of fuel injected from the fuel, the better the stratification will be, and overall, even if the fuel is leaner, combustion will be possible. However, if the degree of stratification is set too high, there is a problem in that the amount of NOx emissions increases. Therefore, by changing the fuel distribution ratio α depending on the rotation speed and load, the degree of stratification can be changed.
NOx can be suppressed. That is, FIG. 8 shows a model of the change in NOx emission amount with respect to the air-fuel ratio when two types of stratification degree, large and small, are selected. As the degree of stratification increases, the air-fuel ratio at which the NOx emission peaks shifts to the leaner side, indicating the above phenomenon.
発明の効果
吸気制御弁が閉鎖する低負荷運転時においてス
ワールポート側の第１燃料噴射弁とストレートポ
ート側の第２燃料噴射弁を共に作動させ、かつそ
の燃料分配を運転条件に応じて適当に変えること
によつて成層度が任意にコントロールされ、
NOx成分の排出の抑制と空燃比のリーン化（即
ち燃料消費率の改善）との双方の要求を調和させ
ることができる。Effects of the Invention During low-load operation when the intake control valve is closed, the first fuel injection valve on the swirl port side and the second fuel injection valve on the straight port side are operated together, and the fuel distribution is appropriately controlled according to the operating conditions. The degree of stratification can be controlled arbitrarily by changing the
It is possible to harmonize the demands for suppressing the emission of NOx components and making the air-fuel ratio leaner (that is, improving the fuel consumption rate).
尚、実施例では燃料噴射量の制御のため噴射時
間を変えているが、その代りに各々の燃料噴射弁
の噴口径、リフト量を変えても同様な効果が得ら
れる。 In the embodiment, the injection time is changed to control the fuel injection amount, but the same effect can be obtained by changing the nozzle diameter and lift amount of each fuel injection valve instead.
第１図は燃料噴射制御のソフトウエアを示すフ
ローチヤート、第２図は吸気制御弁制御のソフト
ウエアを示すフローチヤート、第３図は本発明の
実施例構成図、第４図は回転数、負荷に対する空
燃比設定を説明するための模式的なグラフ、第５
図は高負荷時の燃料室内の混合気分布の説明図、
第６図は低負荷時の燃料室内の混合気分布の説明
図、第７図は負荷、回転数に対する燃料分布比の
設定を模式的に示すグラフ、第８図は空燃比に対
するNOx排出量特性を成層度の大小で示すグラ
フ。
２……第１吸気ポート、３……第２吸気ポー
ト、７……吸気制御弁、２５……制御回路、３１
……第１燃料噴射弁、３２……第２燃料噴射弁。
FIG. 1 is a flowchart showing the software for fuel injection control, FIG. 2 is a flowchart showing the software for controlling the intake control valve, FIG. 3 is a configuration diagram of an embodiment of the present invention, and FIG. 4 is a flow chart showing the rotation speed, 5th schematic graph for explaining air-fuel ratio setting with respect to load
The figure is an explanatory diagram of the air-fuel mixture distribution in the fuel chamber under high load.
Figure 6 is an explanatory diagram of the air-fuel mixture distribution in the fuel chamber at low load, Figure 7 is a graph schematically showing the setting of the fuel distribution ratio with respect to load and rotation speed, and Figure 8 is the NOx emission characteristics with respect to air-fuel ratio. A graph showing the degree of stratification. 2...First intake port, 3...Second intake port, 7...Intake control valve, 25...Control circuit, 31
...First fuel injection valve, 32...Second fuel injection valve.
Claims (1)
ワールを発生させるよう成形された第１吸気ポー
トに配設された第１の燃料噴射弁と、上記燃焼室
に開口するストレート状の第２吸気ポートに設け
られ、この第２吸気ポートを開閉可能な吸気制御
弁と、上記第２吸気ポートの上記吸気制御弁より
下流側に配設された第２燃料噴射弁とを備え、上
記吸気制御弁はエンジンの低回転低負荷域で閉塞
し、上記吸気制御弁の閉塞時において第１燃料噴
射弁及び第２燃料噴射弁からの燃料噴射量の割合
は機関運転条件に応じて制御される複吸気弁エン
ジン。1. A first fuel injection valve disposed in a first intake port that opens into the combustion chamber and is shaped to generate a swirl within the combustion chamber, and a second straight intake port that opens into the combustion chamber. an intake control valve that can open and close the second intake port; and a second fuel injection valve that is disposed downstream of the intake control valve of the second intake port, and the intake control valve A dual intake valve engine in which the intake control valve is closed in a low rotation and low load range, and the ratio of the fuel injection amount from the first fuel injection valve and the second fuel injection valve is controlled according to engine operating conditions when the intake control valve is closed. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59204133A JPS6183459A (en) | 1984-10-01 | 1984-10-01 | Double-suction-valve engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59204133A JPS6183459A (en) | 1984-10-01 | 1984-10-01 | Double-suction-valve engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6183459A JPS6183459A (en) | 1986-04-28 |
| JPH0565705B2 true JPH0565705B2 (en) | 1993-09-20 |
Family
ID=16485380
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59204133A Granted JPS6183459A (en) | 1984-10-01 | 1984-10-01 | Double-suction-valve engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6183459A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006224054A (en) * | 2005-02-21 | 2006-08-31 | Matsushita Electric Ind Co Ltd | Electric dust collecting unit |
| WO2012014288A1 (en) * | 2010-07-27 | 2012-02-02 | トヨタ自動車株式会社 | Internal combustion engine controller |
| JP5581935B2 (en) * | 2010-09-24 | 2014-09-03 | トヨタ自動車株式会社 | Fuel injection control device for internal combustion engine |
-
1984
- 1984-10-01 JP JP59204133A patent/JPS6183459A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6183459A (en) | 1986-04-28 |
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