JPH0238776B2 - - Google Patents
Info
- Publication number
- JPH0238776B2 JPH0238776B2 JP56112285A JP11228581A JPH0238776B2 JP H0238776 B2 JPH0238776 B2 JP H0238776B2 JP 56112285 A JP56112285 A JP 56112285A JP 11228581 A JP11228581 A JP 11228581A JP H0238776 B2 JPH0238776 B2 JP H0238776B2
- Authority
- JP
- Japan
- Prior art keywords
- negative pressure
- air
- valve
- fuel ratio
- approximately
- 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 68
- 238000002485 combustion reaction Methods 0.000 claims description 19
- 239000000203 mixture Substances 0.000 claims description 11
- 230000007423 decrease Effects 0.000 claims description 9
- 238000002347 injection Methods 0.000 description 23
- 239000007924 injection Substances 0.000 description 23
- 238000000034 method Methods 0.000 description 7
- 238000004891 communication Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000012447 hatching Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B31/00—Modifying induction systems for imparting a rotation to the charge in the cylinder
- F02B31/08—Modifying induction systems for imparting a rotation to the charge in the cylinder having multiple air inlets
- F02B31/082—Modifying induction systems for imparting a rotation to the charge in the cylinder having multiple air inlets the main passage having a helical shape around the intake valve axis; Engines characterised by provision of driven charging or scavenging pumps
-
- 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
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Description
【発明の詳細な説明】 本発明は内燃機関に関する。[Detailed description of the invention] The present invention relates to internal combustion engines.
燃料消費率を向上するための一つの方法として
稀薄混合気を用いる方法がある。しかしながら稀
薄混合気は本来火炎の伝播速度が遅く、従つて燃
焼速度が遅いために安定した燃焼を得るのが困難
となつている。特に空燃比が20以上の、いわゆる
超稀薄混合気を用いた場合には更に燃焼速度が遅
くなるために安定した燃焼を得るのが一層困難と
なる。燃焼速度を速める方法として従来より燃焼
室内に旋回流を発生せしめることが知られている
が、この旋回流は強すぎるとシリンダ内壁面から
逃げる熱が多くなるために熱効率が低下し、一方
弱すぎると燃焼速度を十分に速められないために
良好な燃焼が得られず、従つて旋回流には機関の
種類に応じた最適の旋回流の強さが存在すること
が判明している。 One method for improving fuel consumption is to use a lean mixture. However, since a lean mixture inherently has a slow flame propagation speed and therefore a slow combustion speed, it is difficult to obtain stable combustion. In particular, when a so-called ultra-lean mixture with an air-fuel ratio of 20 or more is used, the combustion speed becomes even slower, making it even more difficult to obtain stable combustion. Generating a swirling flow inside the combustion chamber has been known as a method of increasing the combustion rate. However, if this swirling flow is too strong, more heat escapes from the inner wall of the cylinder, resulting in a decrease in thermal efficiency; on the other hand, if it is too weak, It has been found that good combustion cannot be obtained because the combustion speed cannot be sufficiently increased.Therefore, it has been found that there is an optimum swirl flow strength depending on the type of engine.
本発明は空燃比が20以上の超稀薄混合気を用い
ることのできる内燃機関を提供することにある。 An object of the present invention is to provide an internal combustion engine that can use an ultra-lean mixture having an air-fuel ratio of 20 or more.
以下、添附図面を参照して本発明を詳細に説明
する。 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
第１図並びに第２図を参照すると、１はシリン
ダブロツク、２はシリンダブロツク１内で往復動
するピストン、３はシリンダブロツク１上に固定
されたシリンダヘツド、４はピストン２とシリン
ダヘツド３間に形成された燃焼室、５は吸気弁、
６はシリンダヘツド３内に形成されたヘリカル型
吸気ポート、７は排気弁、８はシリンダヘツド３
内に形成された排気ポートを夫々示す。なお、図
には示さないが燃焼室４内に点火栓が配置され
る。 Referring to FIGS. 1 and 2, 1 is a cylinder block, 2 is a piston that reciprocates within cylinder block 1, 3 is a cylinder head fixed on cylinder block 1, and 4 is a link between piston 2 and cylinder head 3. 5 is an intake valve,
6 is a helical intake port formed in the cylinder head 3, 7 is an exhaust valve, and 8 is a cylinder head 3.
Exhaust ports formed therein are shown respectively. Although not shown in the figure, an ignition plug is disposed within the combustion chamber 4.
第３図から第５図に第２図のヘリカル型吸気ポ
ート６の形状を図解的に示す。このヘリカル型吸
気ポート６は第４図に示されるように流路軸線ａ
がわずかに彎曲した入口通路部Ａと、吸気弁５の
弁軸周りに形成された渦巻部Ｂとにより構成さ
れ、入口通路部Ａは渦巻部Ｂに接線状に接続され
る。第３図、第４図並びに第７図に示されるよう
に入口通路部Ａの渦巻軸線ｂに近い側の側壁面９
の上方側壁部９ａは下方を向いた傾斜面に形成さ
れ、この傾斜面９ａの巾は渦巻部Ｂに近づくに従
つて広くなり、入口通路部Ａと渦巻部Ｂとの接続
部においては第７図に示されるように側壁面９の
全体が下方に向いた傾斜面９ａに形成される。側
壁面９の上半分は吸気弁ガイド１０（第２図）周
りの吸気ポート上壁面上に形成された円筒状突起
１１の周壁面に滑らかに接続され、一方側壁面９
の下半分は渦巻部Ｂの渦巻終端部Ｃにおいて渦巻
部Ｂの側壁面１２に接続される。なお、渦巻部Ｂ
の上壁面１３は渦巻終端部Ｃにおいて下向きの急
傾斜壁Ｄに接続される。 3 to 5 schematically show the shape of the helical intake port 6 of FIG. 2. This helical intake port 6 has a flow path axis a as shown in FIG.
It is composed of a slightly curved inlet passage part A and a spiral part B formed around the valve axis of the intake valve 5, and the inlet passage part A is tangentially connected to the spiral part B. As shown in FIGS. 3, 4, and 7, the side wall surface 9 of the inlet passage A near the spiral axis b
The upper side wall portion 9a is formed as an inclined surface facing downward, and the width of this inclined surface 9a becomes wider as it approaches the spiral portion B. As shown in the figure, the entire side wall surface 9 is formed into a downwardly oriented inclined surface 9a. The upper half of the side wall surface 9 is smoothly connected to the peripheral wall surface of a cylindrical projection 11 formed on the upper wall surface of the intake port around the intake valve guide 10 (FIG. 2).
The lower half of the spiral portion B is connected to the side wall surface 12 of the spiral portion B at the spiral end portion C of the spiral portion B. In addition, spiral part B
The upper wall surface 13 is connected to the downwardly inclined wall D at the spiral end C.
一方、第１図から第５図に示されるようにシリ
ンダヘツド３内には入口通路部Ａから分岐された
ほぼ一様断面の分岐路１４が形成され、この分岐
路１４は渦巻終端部Ｃに接続される。分岐路１４
の入口開口１５は入口通路部Ａの入口開口近傍に
おいて側壁面９上に形成され、分岐路１４の出口
開口１６は渦巻終端部Ｃにおいて側壁面１２の上
端部に形成される。更に、シリンダヘツド３内に
は分岐路１４を貫通して延びる開閉弁挿入孔１７
が穿設され、この開閉弁挿入孔１７内には夫々通
路開閉弁の作用をなすロータリ弁１８が挿入され
る。このロータリ弁１８は分岐路１４内に配置さ
れかつ第９図に示すように薄板状をなす弁体１９
と、弁体１９と一体形成された弁軸２０とを具備
し、この弁軸２０は開閉弁挿入孔１７内に嵌着さ
れた案内スリーブ２１により回転可能に支承され
る。弁軸２０は案内スリーブ２１の頂面から上方
に突出し、この突出端部にアーム２２が固着され
る。 On the other hand, as shown in FIGS. 1 to 5, a branch passage 14 having a substantially uniform cross section is formed in the cylinder head 3, branching from the inlet passage part A, and this branch passage 14 is connected to the spiral terminal part C. Connected. Branch road 14
An inlet opening 15 is formed on the side wall surface 9 in the vicinity of the inlet opening of the inlet passage section A, and an outlet opening 16 of the branch passage 14 is formed at the upper end of the side wall surface 12 at the spiral end C. Furthermore, an on-off valve insertion hole 17 is provided in the cylinder head 3 and extends through the branch passage 14.
are drilled, and rotary valves 18 functioning as passage opening/closing valves are inserted into the opening/closing valve insertion holes 17, respectively. This rotary valve 18 is disposed within the branch passage 14 and has a thin plate-like valve body 19 as shown in FIG.
and a valve shaft 20 integrally formed with the valve body 19, and the valve shaft 20 is rotatably supported by a guide sleeve 21 fitted into the opening/closing valve insertion hole 17. The valve stem 20 projects upward from the top surface of the guide sleeve 21, and an arm 22 is fixed to the projecting end.
第１０図を参照すると、吸気ポート６は枝管２
３を介して共通のサージタンク２４に接続され、
更にサージタンク２４はエアダクト２５並びにエ
アクリーナ２６を介して大気に連通する。第２図
並びに第１０図を参照すると各枝管２３には吸気
ポート６内に向けて燃料を噴射するための燃料噴
射弁２７が取付けられ、またエアダクト２５内に
はアクセルペダルに連結されたスロツトル弁２８
が挿入される。一方、各気筒のロータリ弁１８の
アーム２２の先端部は連結ロツド２９によつて互
に連結され、この連結ロツド２９は負圧ダイアフ
ラム装置３０のダイアフラム３１に固着された制
御ロツド３２に連結される。負圧ダイアフラム装
置３０はダイアフラム３１によつて大気から隔離
された負圧室３３を有し、この負圧室３３内にダ
イアフラム押圧用圧縮ばね３４が挿入される。負
圧室３３は導管３５を介して大気連通制御弁３６
の弁室３７に連結される。弁室３７は一方では弁
室３７からサージタンク２４内に向けてのみ流通
可能な逆止弁３８を介してサージタンク２４に連
結され、他方では大気連通ポート３９並びにエア
フイルタ４０を介して大気に連通する。更に、大
気連通制御弁３６は電磁弁４１を具備し、この電
磁弁４１は大気連通ポート３９の開閉制御をする
弁体４２と、弁体４２に連結された可動プランジ
ヤ４３と、可動プランジヤ吸引用のソレノイド４
４から構成される。電磁弁４１のソレノイド４４
は電子制御ユニツト５０の出力端子に接続され
る。更に、スロツトル弁２８にはポテンシヨメー
タ４５が取付けられる。このポテンシヨメータ４
５はスロツトル弁２８に連結されてスロツトル弁
２８と共に回動する摺動子４５ａと、固定抵抗４
５ｂからなり、摺動子４５ａにはスロツトル弁２
８の開度に比例した出力電圧が発生する。 Referring to FIG. 10, the intake port 6 is connected to the branch pipe 2.
3 to a common surge tank 24,
Furthermore, the surge tank 24 communicates with the atmosphere via an air duct 25 and an air cleaner 26. 2 and 10, a fuel injection valve 27 for injecting fuel into the intake port 6 is attached to each branch pipe 23, and a throttle valve connected to an accelerator pedal is installed in the air duct 25. valve 28
is inserted. On the other hand, the ends of the arms 22 of the rotary valves 18 of each cylinder are connected to each other by a connecting rod 29, and this connecting rod 29 is connected to a control rod 32 fixed to a diaphragm 31 of a negative pressure diaphragm device 30. . The negative pressure diaphragm device 30 has a negative pressure chamber 33 isolated from the atmosphere by a diaphragm 31, and a compression spring 34 for pressing the diaphragm is inserted into the negative pressure chamber 33. The negative pressure chamber 33 is connected to an atmosphere communication control valve 36 via a conduit 35.
The valve chamber 37 is connected to the valve chamber 37 of the valve chamber 37 . The valve chamber 37 is connected to the surge tank 24 on one side via a check valve 38 that allows flow only from the valve chamber 37 into the surge tank 24, and on the other side communicates with the atmosphere via an atmosphere communication port 39 and an air filter 40. do. Further, the atmosphere communication control valve 36 includes a solenoid valve 41, and this solenoid valve 41 includes a valve body 42 for controlling the opening and closing of the atmosphere communication port 39, a movable plunger 43 connected to the valve body 42, and a movable plunger for suction. solenoid 4
Consists of 4. Solenoid 44 of solenoid valve 41
is connected to the output terminal of the electronic control unit 50. Further, a potentiometer 45 is attached to the throttle valve 28. This potentiometer 4
5 is a slider 45a connected to the throttle valve 28 and rotates together with the throttle valve 28, and a fixed resistor 4.
5b, and the throttle valve 2 is attached to the slider 45a.
An output voltage proportional to the opening degree of 8 is generated.
電子制御ユニツト５０はデイジタルコンピユー
タからなり、各種の演算処理を行なうマイクロプ
ロセツサ（MPU）５１、ランダムアクセスメモ
リ（RAM）５２、制御プログラム、演算定数等
が予め格納されているリードオンリメモリ
（ROM）５３、入力ポート５４並びに出力ポー
ト５５が双方向性バス５６を介して互に接続され
ている。更に、電子制御ユニツト５０内には各種
のクロツク信号を発生するクロツク発生器５７が
設けられる。入力ポート５４にはサージタンク２
４内の負圧を検出するための負圧センサ５８が
AD変換器５９を介して接続され、更に入力ポー
ト５４にはポテンシヨメータ４５がAD変換器６
０を介して接続される。また、入力ポート５４に
は回転数センサ６１が接続される。負圧センサ５
８はサージタンク２４内の負圧に比例した出力電
圧を発生し、この電圧がAD変換器５９において
対応する２進数に変換されてこの２進数が入力ポ
ート５４並びにバス５６を介してMPU５１に入
力される。ポテンシヨメータ４５は前述したよう
にスロツトル弁２８の開度に比例した出力電圧を
発生し、この電圧がAD変換器６０において対応
する２進数に変換されてこの２進数が入力ポート
５４並びにバス５６を介してMPU５１に入力さ
れる。一方、回転数センサ６１は機関クランクシ
ヤフトが所定クランク角度回転する毎にパルスを
発生し、このパルスが入力ポート５４並びにバス
５６を介してMPU５１に入力される。 The electronic control unit 50 consists of a digital computer, including a microprocessor (MPU) 51 that performs various calculation processes, a random access memory (RAM) 52, and a read-only memory (ROM) in which control programs, calculation constants, etc. are stored in advance. 53, an input port 54, and an output port 55 are connected to each other via a bidirectional bus 56. Furthermore, a clock generator 57 is provided within the electronic control unit 50 for generating various clock signals. Surge tank 2 is connected to input port 54.
A negative pressure sensor 58 for detecting negative pressure within the
A potentiometer 45 is connected to the input port 54 via an AD converter 59, and a potentiometer 45 is connected to the AD converter 6.
Connected via 0. Further, a rotation speed sensor 61 is connected to the input port 54 . Negative pressure sensor 5
8 generates an output voltage proportional to the negative pressure inside the surge tank 24, and this voltage is converted into a corresponding binary number in the AD converter 59, and this binary number is input to the MPU 51 via the input port 54 and bus 56. be done. As described above, the potentiometer 45 generates an output voltage proportional to the opening degree of the throttle valve 28, and this voltage is converted into a corresponding binary number by the AD converter 60. The signal is input to the MPU 51 via. On the other hand, the rotation speed sensor 61 generates a pulse every time the engine crankshaft rotates by a predetermined crank angle, and this pulse is input to the MPU 51 via the input port 54 and the bus 56.
出力ポート５５は燃料噴射弁２７と電磁弁４１
とを作動するためのデータを出力するために設け
られており、この出力ポート５５には２進数のデ
ータがMPU５１からバス５６を介して書込まれ
る。出力ポート５５の出力端子は一方では電力増
幅回路６２を介して電磁弁４１のソレノイド４４
に接続され、他方ではダウンカウンタ６３の対応
する入力端子に接続される。このダウンカウンタ
６３はMPU５１から書込まれた２進数のデータ
をそれに対応する時間の長さに変換するために設
けられており、このダウンカウンタ６３は出力ポ
ート５５から送り込まれたデータのダウンカウン
タをクロツク発生器５７のクロツク信号によつて
開始し、カウント値が０になるとカウントを完了
して出力端子にカウント完了信号を発生する。Ｓ
−Ｒフリツプフロツプ６４のリセツト入力端子Ｒ
はダウンカウンタ６３の出力端子に接続され、Ｓ
−Ｒフリツプフロツプ６４のセツト入力端子Ｓは
クロツク発生器５７に接続される。このＳ−Ｒフ
リツプフロツプ６４はクロツク発生器５７のクロ
ツク信号によりダウンカウント開始と同時にセツ
トされ、ダウンカウント完了時にダウンカウンタ
６３のカウント完了信号によつてリセツトされ
る。従つてＳ−Ｒフリツプフロツプ６４の出力端
子Ｑはダウンカウントが行なわれている間高レベ
ルとなる。Ｓ−Ｒフリツプフロツプ６４の出力端
子Ｑは電力増幅回路６５を介して燃料噴射弁２７
に接続されており、従つて燃料噴射弁２７はダウ
ンカウンタ６３がダウンカウントしている間付勢
されることがわかる。 The output port 55 is connected to the fuel injection valve 27 and the solenoid valve 41.
Binary data is written to this output port 55 from the MPU 51 via a bus 56. On the one hand, the output terminal of the output port 55 is connected to the solenoid 44 of the solenoid valve 41 via the power amplifier circuit 62.
and the corresponding input terminal of the down counter 63 on the other hand. This down counter 63 is provided to convert the binary data written from the MPU 51 into the corresponding time length, and this down counter 63 converts the down counter of the data sent from the output port 55. It is started by a clock signal from the clock generator 57, and when the count value reaches 0, the counting is completed and a count completion signal is generated at the output terminal. S
-R Reset input terminal R of flip-flop 64
is connected to the output terminal of the down counter 63, and S
The set input terminal S of the -R flip-flop 64 is connected to the clock generator 57. This SR flip-flop 64 is set by the clock signal of the clock generator 57 at the same time as the down count starts, and is reset by the count completion signal of the down counter 63 when the down count is completed. Therefore, the output terminal Q of the S-R flip-flop 64 is at a high level while the down count is being performed. The output terminal Q of the S-R flip-flop 64 is connected to the fuel injector 27 via a power amplifier circuit 65.
Therefore, it can be seen that the fuel injection valve 27 is energized while the down counter 63 is counting down.
一方、前述したように出力ポート５５の出力端
子は電磁弁４１に接続される。電磁弁４１のソレ
ノイド４４が付勢されると弁体４２は大気連通ポ
ート３９を開口する。その結果、負圧室３３内は
大気圧となるのでダイアフラム３１は圧縮ばね３
４のばね力により下方に移動し、斯しくてロータ
リ弁１８が回動せしめられて分岐路１４を全開す
る。一方、電磁弁４１のソレノイド４４が消勢さ
れると弁体４２が大気連通ポート３９を閉鎖す
る。このとき逆止弁３８はサージタンク２４内の
負圧が負圧ダイアフラム装置３０の負圧室３３内
の負圧よりも大きくなると開弁し、サージタンク
２４内の負圧が負圧室３３内の負圧よりも小さく
なると閉弁するので弁体４２が閉弁している限り
負圧室３３内の負圧はサージタンク２４内に発生
した最大負圧に維持される。負圧室３３内に負圧
が加わるとダイアフラム３１は圧縮ばね３４に抗
して上昇し、その結果ロータリ弁１８が回動せし
められて分岐路１４が閉鎖される。 On the other hand, as described above, the output terminal of the output port 55 is connected to the solenoid valve 41. When the solenoid 44 of the electromagnetic valve 41 is energized, the valve body 42 opens the atmosphere communication port 39. As a result, the inside of the negative pressure chamber 33 becomes atmospheric pressure, so the diaphragm 31
4, the rotary valve 18 is rotated and the branch passage 14 is fully opened. On the other hand, when the solenoid 44 of the electromagnetic valve 41 is deenergized, the valve body 42 closes the atmosphere communication port 39. At this time, the check valve 38 opens when the negative pressure in the surge tank 24 becomes larger than the negative pressure in the negative pressure chamber 33 of the negative pressure diaphragm device 30, and the negative pressure in the surge tank 24 increases in the negative pressure chamber 33. Since the valve closes when the negative pressure becomes smaller than the negative pressure of , the negative pressure in the negative pressure chamber 33 is maintained at the maximum negative pressure generated in the surge tank 24 as long as the valve body 42 is closed. When negative pressure is applied within the negative pressure chamber 33, the diaphragm 31 rises against the compression spring 34, and as a result, the rotary valve 18 is rotated and the branch passage 14 is closed.
第１１図はサージタンク２４内の負圧Ｐ（−mm
Hg）と機関回転数Ｎ（rpm）に対する空燃比Ａ／
Ｆを示している。第１１図において図中に記載さ
れた数値は空燃比を示しているが実際には第１１
図は図中に記載された空燃比となるような燃料噴
射時間が書込まれたマツプとなつている。従つて
機関回転数Ｎと負圧Ｐが定まると第１１図から燃
料噴射時間が定まり、そのとき機関シリンダ内に
供給される空燃比は第１１図中に記載された数値
のようになる。第１１図に示す燃料噴射時間のマ
ツプは予めROM５３内に記憶されている。第１
１図からわかるように燃料噴射量は機関回転数Ｎ
がほぼ1400rpmからほぼ3200rpmの間でかつ負圧
Ｐがほぼ350mmHgよりも小さなときに空燃比が22
となるように設定されている。更に、機関回転数
Ｎがほぼ600rpmからほぼ1400rpmの間では機関
回転数Ｎが低くなるにつれて空燃比が100rpm当
り1.25〜2.75づつ小さくなるように設定されてい
る。これは機関回転数Ｎが小さくなつた場合に空
燃比が大きいとトルク変動を生じ、このトルク変
動を抑制するために機関回転数Ｎが小さくなるに
つれて空燃比を小さくするようにしている。一
方、負圧Ｐが−350mmHgよりも大きなときには負
圧Ｐが大きくなるにつれて空燃比が100mmHg当り
１〜２づつ小さくなるように設定されている。こ
れは負圧Ｐが大きくなつた場合に空燃比が大きい
とトルク変動を生じ、このトルク変動を抑制する
ために負圧Ｐが大きくなるにつれて空燃比を小さ
くするようにしている。また、機関回転数Ｎがほ
ぼ3200rpm以上では空燃比は100rpm当り0.5〜1.5
づつ小さくなるように設定され、それによつて機
関回転数Ｎが高いときに高出力が得られるように
している。 Figure 11 shows the negative pressure P (-mm
Hg) and air-fuel ratio A/ for engine speed N (rpm)
It shows F. In Figure 11, the numbers written in the figure indicate the air-fuel ratio, but actually
The figure is a map in which the fuel injection time to achieve the air-fuel ratio shown in the figure is written. Therefore, when the engine speed N and the negative pressure P are determined, the fuel injection time is determined from FIG. 11, and the air-fuel ratio supplied into the engine cylinder at that time becomes the numerical value shown in FIG. The fuel injection time map shown in FIG. 11 is stored in the ROM 53 in advance. 1st
As can be seen from Figure 1, the fuel injection amount depends on the engine speed N.
is between approximately 1400 rpm and approximately 3200 rpm and the negative pressure P is less than approximately 350 mmHg, the air-fuel ratio is 22
It is set so that Further, when the engine speed N is between approximately 600 rpm and approximately 1400 rpm, the air-fuel ratio is set to decrease by 1.25 to 2.75 per 100 rpm as the engine speed N decreases. This is because when the engine speed N decreases and the air-fuel ratio is large, torque fluctuations occur, and in order to suppress this torque fluctuation, the air-fuel ratio is made smaller as the engine speed N decreases. On the other hand, when the negative pressure P is greater than -350 mmHg, the air-fuel ratio is set to decrease by 1 to 2 per 100 mmHg as the negative pressure P increases. This is because when the negative pressure P increases and the air-fuel ratio is large, torque fluctuations occur, and in order to suppress this torque fluctuation, the air-fuel ratio is made smaller as the negative pressure P increases. Also, when the engine speed N is approximately 3200 rpm or more, the air-fuel ratio is 0.5 to 1.5 per 100 rpm.
This is set to gradually decrease, thereby allowing high output to be obtained when the engine speed N is high.
第１１図のマツプによる燃料噴射量の制御はス
ロツトル弁２８の開度が第１２図のθ0よりも小さ
いときに行なわれ、スロツトル弁２８の開度が第
１２図のθ0よりも大きいときにはスロツトル弁２
８の開度によつて燃料噴射量の制御が行なわれ
る。なお、第１２図において縦軸θはスロツトル
弁２８の開度θを示しており、スロツトル開度
80゜は全開状態を示している。第１２図からわか
るように開度θ0は機関回転数Ｎが1000rpmのとき
30゜〜40゜であり、機関回転数Ｎが4000rpmのとき
50゜〜60゜である。この開度θ0に対応する負圧Ｐが
第１１図において破線Ｔで示される。従つて第１
１図の破線Ｔよりも負圧Ｐが小さなとき、即ち第
１２図の開度θ0よりもスロツトル弁２８の開度θ
が大きなときにはスロツトル弁２８の開度によつ
て燃料噴射量が制御される。第１１図の破線Ｔよ
りも負圧Ｐが小さなときには高出力を得るために
負圧Ｐが小さくなるに従つて空燃比が急激に減少
せしめられ、従つて負圧Ｐがわずかばかり変化す
ると空燃比が大きく変化するので空燃比を負圧Ｐ
に応じて変化させると細かな制御が難かしくな
る。斯くして第１１図の破線Ｔよりも負圧Ｐが小
さなときにはスロツトル弁２８の開度θによつて
燃料噴射量の制御が行なわれる。なお、第１２図
において実線θ0で示される機関回転数Ｎとスロツ
トル弁開度θの関係は予めROMS５３内に記憶
されている。 Control of the fuel injection amount using the map in FIG. 11 is performed when the opening degree of the throttle valve 28 is smaller than θ 0 in FIG. 12, and when the opening degree of the throttle valve 28 is larger than θ 0 in FIG. Throttle valve 2
The fuel injection amount is controlled by the opening degree of 8. In addition, in FIG. 12, the vertical axis θ indicates the opening degree θ of the throttle valve 28, and the throttle opening degree
80° indicates a fully open state. As can be seen from Figure 12, the opening degree θ 0 is when the engine speed N is 1000 rpm.
30° to 40° and when the engine speed N is 4000 rpm
The angle is between 50° and 60°. The negative pressure P corresponding to this opening degree θ 0 is indicated by a broken line T in FIG. Therefore, the first
When the negative pressure P is smaller than the broken line T in Fig. 1, that is, the opening θ of the throttle valve 28 is smaller than the opening θ 0 in Fig. 12.
When the amount is large, the fuel injection amount is controlled by the opening degree of the throttle valve 28. When the negative pressure P is smaller than the broken line T in Fig. 11, the air-fuel ratio is rapidly decreased as the negative pressure P becomes smaller in order to obtain high output. changes significantly, so the air-fuel ratio is reduced to negative pressure P.
If you change it according to the , detailed control becomes difficult. Thus, when the negative pressure P is smaller than the broken line T in FIG. 11, the fuel injection amount is controlled by the opening degree θ of the throttle valve 28. The relationship between the engine speed N and the throttle valve opening θ, which is indicated by the solid line θ 0 in FIG. 12, is stored in the ROMS 53 in advance.
第１３図はスロツトル弁２８の開度θと機関回
転数Ｎに対する空燃比Ａ／Ｆを示している。第１
３図において図中に記載された数値は空燃比を示
しているが実際には第１３図は図中に記載された
空燃比となるような燃料噴射時間が書込まれたマ
ツプとなつている。従つて機関回転数Ｎとスロツ
トル弁開度θが定まると第１３図から燃料噴射時
間が定まり、そのとき機関シリンダ内に供給され
る空燃比は第１３図中に記載された数値のように
なる。第１３図に示す燃料噴射時間のマツプは予
めROM５３内に記憶されている。第１３図から
わかるように燃料噴射量はスロツトル弁開度θが
大きくなるにつれて空燃比が小さくなるように設
定されており、スロツトル弁２８が全開したとき
には空燃比は12.5程度となる。 FIG. 13 shows the air-fuel ratio A/F with respect to the opening degree θ of the throttle valve 28 and the engine speed N. 1st
In Figure 3, the numbers written in the figure indicate the air-fuel ratio, but in reality, Figure 13 is a map in which the fuel injection time that will result in the air-fuel ratio written in the figure is written. . Therefore, when the engine speed N and throttle valve opening θ are determined, the fuel injection time is determined from FIG. 13, and the air-fuel ratio supplied to the engine cylinder at that time becomes the numerical value shown in FIG. . The fuel injection time map shown in FIG. 13 is stored in the ROM 53 in advance. As can be seen from FIG. 13, the fuel injection amount is set so that the air-fuel ratio decreases as the throttle valve opening θ increases, and when the throttle valve 28 is fully open, the air-fuel ratio is approximately 12.5.
次いで第１５図を参照して燃料噴射制御につい
て説明する。第１５図を参照すると、まず始めに
ステツプ70において回転数センサ６１の出力信号
がMPU５１に入力されて機関回転数Ｎが計算さ
れる。次いでステツプ71においてスロツトル弁開
度θを表わすポテンシヨメータ４５の出力信号が
MPU５１に入力され、次いでステツプ72におい
て負圧Ｐを表わす負圧センサ５８の出力信号が
MPU５１に入力される。次いでステツプ73にお
いてスロツトル開度θと機関回転数Ｎとにより定
まる第１２図の点Ｑ（Ｎ）が第１２図の開度θ0よ
りも大きいか否かが判別される。ステツプ73にお
いてＱ（Ｎ）が開度θ0よりも大きくないと判別さ
れたときはステツプ74に進んで第１１図に示すマ
ツプから燃料噴射時間Ｔが計算され、次いでステ
ツプ75に進む。一方、ステツプ73においてＱ（Ｎ）
が開度θ0よりも大きいと判別されたときはステツ
プ76に進んで第１３図に示すマツプから燃料噴射
時間Ｔが計算され、次いでステツプ75に進む。ス
テツプ75ではステツプ74或いはステツプ76におい
て求められた燃料噴射時間Ｔに対応する駆動デー
タを出力ポート５５に書込み、この燃料噴射時間
Ｔだけ燃料噴射弁２７から燃料が噴射される。従
つて機関シリンダ内には第１１図或いは第１３図
に示すような空燃比の混合気が供給される。 Next, fuel injection control will be explained with reference to FIG. Referring to FIG. 15, first, in step 70, the output signal of the rotation speed sensor 61 is input to the MPU 51, and the engine rotation speed N is calculated. Next, in step 71, the output signal of the potentiometer 45 representing the throttle valve opening θ is
The output signal of the negative pressure sensor 58 representing the negative pressure P is inputted to the MPU 51 and then in step 72.
It is input to MPU51. Next, in step 73, it is determined whether the point Q(N) in FIG. 12, which is determined by the throttle opening .theta. and the engine speed N, is larger than the opening .theta..sub.0 in FIG. If it is determined in step 73 that Q(N) is not greater than the opening degree θ 0 , the process proceeds to step 74 where the fuel injection time T is calculated from the map shown in FIG. 11, and then the process proceeds to step 75. On the other hand, in step 73, Q(N)
If it is determined that the opening degree θ 0 is greater than the opening degree θ 0 , the process proceeds to step 76 where the fuel injection time T is calculated from the map shown in FIG. 13, and then the process proceeds to step 75. In step 75, drive data corresponding to the fuel injection time T determined in step 74 or step 76 is written to the output port 55, and fuel is injected from the fuel injection valve 27 for this fuel injection time T. Therefore, an air-fuel mixture having an air-fuel ratio as shown in FIG. 11 or 13 is supplied into the engine cylinder.
第１４図は電磁弁４１を作動すべき機関回転数
Ｎ（rpm）とサージタンク２４内の負圧Ｐ（−mm
Hg）との関係を示しており、この関係は予め
ROM５３内に記憶されている。電磁弁４１は第
１４図の実線Ｗよりも上方のハツチングで示され
る領域で付勢される。第１４図の実線Ｗはほぼ吸
入空気量が一定のところを示しており、従つて吸
入空気量が所定量以上になるとソレノイド４４を
付勢すべきデータが出力ポート５５に書込まれて
ソレノイド４４が付勢される。ソレノイド４４が
付勢されるとロータリ弁１８が分岐路１４を全開
する。従つて吸入空気量が多いときにはロータリ
弁１８が分岐路１４を全開し、一方吸入空気量が
少ないときにはロータリ弁１８が分岐路１４を閉
鎖することがわかる。 Figure 14 shows the engine speed N (rpm) at which the solenoid valve 41 should be operated and the negative pressure P (-mm) in the surge tank 24.
Hg), and this relationship has been determined in advance.
It is stored in the ROM53. The solenoid valve 41 is energized in the region shown by hatching above the solid line W in FIG. The solid line W in FIG. 14 indicates a point where the amount of intake air is approximately constant. Therefore, when the amount of intake air exceeds a predetermined amount, data to energize the solenoid 44 is written to the output port 55 and the solenoid 44 is activated. is energized. When the solenoid 44 is energized, the rotary valve 18 fully opens the branch passage 14. Therefore, it can be seen that when the amount of intake air is large, the rotary valve 18 fully opens the branch passage 14, while when the amount of intake air is small, the rotary valve 18 closes the branch passage 14.
上述したように吸入空気量の少ない機関低速低
負荷運転時にはロータリ弁１８が分岐路１４を遮
断している。このとき入口通路部Ａ内に送り込ま
れた吸入空気は渦巻部Ｂの上壁面１３に沿つて旋
回しつつ渦巻部Ｂ内を下降し、次いで旋回しつつ
燃焼室４内に流入するので燃焼室４内には強力な
旋回流が発生せしめられる。第１６図はスワール
比Ｓ（クランク角度360度当りの燃焼室内における
旋回流の旋回数）と燃料消費率Ｑとの関係を示
す。第１６図からわかるように空燃比が22のよう
に超稀薄混合気を用いた場合にはスワール比がほ
ぼ1.5から３の範囲で燃料消費率Ｑが低く、これ
以上スワール比Ｓが大きくなつても小さくなつて
も燃料消費率が悪化する。本発明に係るヘリカル
型吸気ポートでは1.5から３の範囲のスワール比
が得られ、斯くして超稀薄混合気でも安定した燃
焼を得ることができる。 As described above, the rotary valve 18 shuts off the branch passage 14 when the engine is operating at low speed and low load with a small amount of intake air. At this time, the intake air sent into the inlet passage part A descends inside the swirl part B while swirling along the upper wall surface 13 of the swirl part B, and then flows into the combustion chamber 4 while swirling. A strong swirling flow is generated inside. FIG. 16 shows the relationship between the swirl ratio S (the number of turns of the swirling flow in the combustion chamber per 360 degrees of crank angle) and the fuel consumption rate Q. As can be seen from Figure 16, when an ultra-lean mixture with an air-fuel ratio of 22 is used, the fuel consumption rate Q is low when the swirl ratio is approximately in the range of 1.5 to 3, and the swirl ratio S increases beyond this range. Even if the fuel consumption rate becomes smaller, the fuel consumption rate will worsen. With the helical intake port according to the present invention, a swirl ratio in the range of 1.5 to 3 can be obtained, and thus stable combustion can be obtained even with an ultra-lean mixture.
一方、吸入空気量が多い機関高速高負荷運転時
にはロータリ弁１８が開弁するので入口通路部Ａ
内に送り込まれた吸入空気の一部が流れ抵抗の小
さな分岐路１４を介して渦巻部Ｂ内に送り込まれ
る。分岐路１４から渦巻部Ｂ内に流入した吸入空
気は入口通路部Ａから渦巻部Ｂ内に流入して旋回
しつつ流れる吸入空気流を減速させる作用をなす
ので旋回流が弱められる。このように機関高速高
負荷運転時にはロータリ弁１８が開弁することに
よつて全体の流路面積が増大するばかりでなく旋
回流が弱められるので高い充填効率を確保でき、
斯しくて高出力を得ることができる。また、入口
通路部Ａに傾斜側端部９ａを設けることによつて
入口通路部Ａ内に送り込まれた吸入空気の一部は
下向きの力を与えられ、その結果この吸入空気は
旋回することなく入口通路部Ａの下壁面に沿つて
渦巻部Ｂ内に流入するために流入抵抗は小さくな
り、斯くして高速高負荷運転時における充填効率
を更に高めることができる。 On the other hand, during engine high-speed, high-load operation with a large amount of intake air, the rotary valve 18 opens, so the inlet passage A
A part of the intake air sent into the spiral portion B is sent into the spiral portion B via the branch path 14 having low flow resistance. The intake air that has flowed into the spiral portion B from the branch passage 14 flows into the spiral portion B from the inlet passage portion A and has the effect of decelerating the flowing intake air flow while swirling, thereby weakening the swirling flow. In this manner, when the engine is operated at high speed and under high load, the rotary valve 18 opens, which not only increases the overall flow path area but also weakens the swirling flow, ensuring high filling efficiency.
In this way, high output can be obtained. Furthermore, by providing the inclined end 9a in the inlet passage A, a portion of the intake air sent into the inlet passage A is given a downward force, and as a result, this intake air is prevented from swirling. Since the liquid flows into the spiral part B along the lower wall surface of the inlet passage part A, the inflow resistance becomes small, and thus the filling efficiency during high-speed, high-load operation can be further improved.
以上述べたように本発明によれば燃焼室内にス
ワール比が1.5から３の最適な旋回流が発生せし
められるので超稀薄混合気を用いても安定した燃
焼を得ることができる。更に機関回転数が低いと
きには空燃比が減少せしめられるのでトルク変動
を抑制でき、良好な運転性を確保することができ
る。また、機関高負荷運転時には空燃比が減少せ
しめられるので高出力を得ることができる。 As described above, according to the present invention, an optimal swirl flow with a swirl ratio of 1.5 to 3 is generated in the combustion chamber, so that stable combustion can be obtained even when using an ultra-lean mixture. Furthermore, since the air-fuel ratio is reduced when the engine speed is low, torque fluctuations can be suppressed and good drivability can be ensured. Furthermore, since the air-fuel ratio is reduced during high-load engine operation, high output can be obtained.
第１図は本発明に係る内燃機関の平面図、第２
図は第１図の−線に沿つてみた断面図、第３
図はヘリカル型吸気ポートの形状をす斜視図、第
４図は第３図の平面図、第５図は第３図の分岐路
に沿つて切断した側面断面図、第６図は第４図の
−線に沿つてみた断面図、第７図は第４図の
−線に沿つてみた断面図、第８図は第４図の
−線に沿つてみた断面図、第９図はロータリ
弁の斜視図、第１０図は吸気装置の全体図、第１
１図はサージタンク内の負圧と機関回転数によつ
て定まる空燃比を示す図、第１２図はスロツトル
弁開度制御に切換わるスロツトル開度を示す図、
第１３図はスロツトル弁開度と機関回転数によつ
て定まる空燃比を示す図、第１４図は開閉弁の開
弁領域を示す図、第１５図は燃料噴射制御の作動
を示すフローチヤート、第１６図は燃料消費率と
スワール比との関係を示すグラフである。
６……ヘリカル型吸気ポート、２４……サージ
タンク、２７……燃料噴射弁、２８……スロツト
ル弁、５８……負圧センサ、６１……回転数セン
サ。
Fig. 1 is a plan view of an internal combustion engine according to the present invention, Fig. 2 is a plan view of an internal combustion engine according to the present invention;
The figure is a cross-sectional view taken along the - line in Figure 1.
The figure is a perspective view of the shape of the helical intake port, Figure 4 is a plan view of Figure 3, Figure 5 is a side cross-sectional view taken along the branching path of Figure 3, and Figure 6 is Figure 4. 7 is a sectional view taken along the - line in Fig. 4, Fig. 8 is a sectional view taken along the - line in Fig. 4, and Fig. 9 is a sectional view taken along the - line in Fig. 4. Figure 10 is a perspective view of the intake system, and Figure 1 is an overall view of the intake system.
Figure 1 is a diagram showing the air-fuel ratio determined by the negative pressure in the surge tank and engine speed, Figure 12 is a diagram showing the throttle opening when switching to throttle valve opening control,
FIG. 13 is a diagram showing the air-fuel ratio determined by the throttle valve opening and engine speed, FIG. 14 is a diagram showing the opening range of the on-off valve, and FIG. 15 is a flowchart showing the operation of fuel injection control. FIG. 16 is a graph showing the relationship between fuel consumption rate and swirl ratio. 6... Helical intake port, 24... Surge tank, 27... Fuel injection valve, 28... Throttle valve, 58... Negative pressure sensor, 61... Rotational speed sensor.
Claims (1)
機関回転数がほぼ1400rpm以上でかつ吸気通路内
負圧がほぼ−50mmHgからほぼ−350mmHgのとき
に一定空燃比の稀薄混合気を形成し、機関回転数
がほぼ1400rpm以下のときには機関回転数が減少
するにつれて混合気の空燃比を上記一定空燃比よ
りも小さくし、吸気通路内負圧がほぼ−50mmHg
よりも小さなときには吸気通路内負圧が小さくな
るにつれて混合気の空燃比を上記一定空燃比より
も小さくするようにした燃料供給装置を具備し、
更に吸気ポートをほぼ1.5から３のスワール比が
得られるヘリカル型に形成した内燃機関。1. In response to the engine speed and the negative pressure in the intake passage, a lean mixture with a constant air-fuel ratio is formed when the engine speed is approximately 1400 rpm or more and the negative pressure in the intake passage is approximately -50 mmHg to approximately -350 mmHg, When the engine speed is approximately 1400 rpm or less, as the engine speed decreases, the air-fuel ratio of the mixture is made smaller than the above constant air-fuel ratio, and the negative pressure in the intake passage is approximately -50 mmHg.
a fuel supply device configured to make the air-fuel ratio of the air-fuel mixture smaller than the constant air-fuel ratio as the negative pressure in the intake passage becomes smaller;
Furthermore, this internal combustion engine has a helical intake port that achieves a swirl ratio of approximately 1.5 to 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56112285A JPS5828512A (en) | 1981-07-20 | 1981-07-20 | Suction device of internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56112285A JPS5828512A (en) | 1981-07-20 | 1981-07-20 | Suction device of internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5828512A JPS5828512A (en) | 1983-02-19 |
| JPH0238776B2 true JPH0238776B2 (en) | 1990-08-31 |
Family
ID=14582859
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56112285A Granted JPS5828512A (en) | 1981-07-20 | 1981-07-20 | Suction device of internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5828512A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6153419A (en) * | 1984-08-20 | 1986-03-17 | Toyota Motor Corp | Method of controlling intake in variable intake swirl system internal-combustion engine |
-
1981
- 1981-07-20 JP JP56112285A patent/JPS5828512A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5828512A (en) | 1983-02-19 |
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