JPH11280504A - Spark ignition internal combustion engine - Google Patents

Spark ignition internal combustion engine

Info

Publication number
JPH11280504A
JPH11280504A JP10085767A JP8576798A JPH11280504A JP H11280504 A JPH11280504 A JP H11280504A JP 10085767 A JP10085767 A JP 10085767A JP 8576798 A JP8576798 A JP 8576798A JP H11280504 A JPH11280504 A JP H11280504A
Authority
JP
Japan
Prior art keywords
engine
spark ignition
intake
valve
compression ratio
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.)
Granted
Application number
JP10085767A
Other languages
Japanese (ja)
Other versions
JP4019492B2 (en
Inventor
Akihiro Iiyama
明裕 飯山
Tomonori Urushibara
友則 漆原
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Priority to JP08576798A priority Critical patent/JP4019492B2/en
Publication of JPH11280504A publication Critical patent/JPH11280504A/en
Application granted granted Critical
Publication of JP4019492B2 publication Critical patent/JP4019492B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

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
    • F02B69/00—Internal-combustion engines convertible into other combustion-engine type, not provided for in F02B11/00; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types
    • F02B69/06—Internal-combustion engines convertible into other combustion-engine type, not provided for in F02B11/00; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types for different cycles, e.g. convertible from two-stroke to four stroke
    • 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
    • F02B1/00—Engines characterised by fuel-air mixture compression
    • F02B1/12—Engines characterised by fuel-air mixture compression with compression ignition
    • 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
    • F02B1/00—Engines characterised by fuel-air mixture compression
    • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
    • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
    • 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
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Exhaust-Gas Circulating Devices (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a spark ignition internal combustion engine capable of performing good combustion in both self ignition combustion and spark ignition combustion, also easily ensuring durability of the engine and a seal property of combustion gas. SOLUTION: An internal combustion engine is provided with a first/second intake valves 30 and a first/second exhaust valves 34, respectively opening/ closing a first/second intake passages 22 and a first/second exhaust passages 26 opened to a combustion chamber 18 synchronously with rotation of the engine, and a control valve 46 changing actual compression ratio of the engine by changing open/close timing of both the intake valves 30. In this constitution, the actual compression ratio at self ignition combustion time and the actual compression ratio at spark ignition operation time are made different by this control valve 46.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、運転領域に応じて
自己着火燃焼と火花点火燃焼との両方を行わせる火花点
火式内燃機関の改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a spark ignition type internal combustion engine which performs both self-ignition combustion and spark ignition combustion according to an operation range.

【０００２】[0002]

【従来の技術】２サイクル型の内燃機関の分野において
は、低負荷運転領域で自己着火燃焼を行わせる機関につ
いて様々な提案がなされており、例えば、特開平９−２
４２５７０号公報には、自己着火燃焼に適した圧縮比と
通常の火花点火燃焼に適した圧縮比との両立を図るた
め、運転状態に応じて燃焼室容積を変更するものが開示
されている。2. Description of the Related Art In the field of a two-cycle internal combustion engine, various proposals have been made for an engine that performs self-ignition combustion in a low load operation range.
Japanese Patent No. 42570 discloses a technique in which the volume of a combustion chamber is changed in accordance with an operation state in order to achieve both a compression ratio suitable for self-ignition combustion and a compression ratio suitable for normal spark ignition combustion.

【０００３】[0003]

【発明が解決しようとする課題】本出願人はこの様な自
己着火を４サイクル型の内燃機関に適用する場合に特に
有効な技術を先に提案している（特願平９−２９６５６
７号等）。４サイクル型の内燃機関においても自己着火
燃焼と火花点火燃焼との両方を良好に行わせるにはそれ
ぞれに適した圧縮比とするのが望ましいのであるが、前
述の従来技術のように燃焼圧力を直接受ける部位に可動
部材を設けて圧縮比を可変にする場合は、可動部分の耐
久性確保や可動部分の燃焼ガスのシール性確保等が困難
となる。The present applicant has previously proposed a technique particularly effective when such self-ignition is applied to a four-cycle internal combustion engine (Japanese Patent Application No. 9-29656).
No. 7). Even in a four-cycle type internal combustion engine, it is desirable to set the compression ratios to be suitable for each of the self-ignition combustion and the spark ignition combustion in order to perform well. In the case where the movable member is provided directly at the receiving portion to change the compression ratio, it becomes difficult to ensure the durability of the movable portion, the sealing property of the combustion gas at the movable portion, and the like.

【０００４】ところで、一般的な４サイクル型の内燃機
関のように、燃焼室内への新気あるいは燃料との混合気
の充填効率が機関の回転に同期して駆動される吸気弁の
開閉時期によって変化する機関では、吸気弁の開閉時期
を変更することにより実質的な圧縮比を変更することが
可能である。本発明は、機関の回転に同期して駆動され
る吸気弁を有する内燃機関を前提とし、自己着火燃焼と
火花点火燃焼との両方の燃焼とも良好に行わせる火花点
火式内燃機関を提供することを目的とする。As in a general four-cycle internal combustion engine, the charging efficiency of fresh air or a mixture with fuel in the combustion chamber depends on the opening and closing timing of an intake valve driven in synchronization with the rotation of the engine. In a changing engine, it is possible to change the substantial compression ratio by changing the opening / closing timing of the intake valve. The present invention is based on the premise that an internal combustion engine having an intake valve driven in synchronization with the rotation of the engine is provided, and to provide a spark ignition type internal combustion engine that can favorably perform both self-ignition combustion and spark ignition combustion. With the goal.

【０００５】[0005]

【課題を解決するための手段】そこで、請求項１の発明
は、所定の運転領域で自己着火燃焼を行わせ、前記所定
の運転領域以外の運転領域で火花点火燃焼を行わせる火
花点火式内燃機関において、機関の回転に同期して燃焼
室に開口する吸気通路および排気通路をそれぞれ開閉す
る吸気弁および排気弁と、前記吸気弁の開閉時期を変更
することにより機関の実圧縮比を変更する可変動弁機構
と、を備え、この可変動弁機構により、自己着火燃焼時
の実圧縮比と火花点火運転時の実圧縮比とを異ならせる
ことを特徴としている。SUMMARY OF THE INVENTION Accordingly, a first aspect of the present invention is a spark ignition type internal combustion engine in which self-ignition combustion is performed in a predetermined operation region and spark ignition combustion is performed in an operation region other than the predetermined operation region. In the engine, the actual compression ratio of the engine is changed by changing the opening and closing timing of the intake valve and the exhaust valve that respectively open and close the intake passage and the exhaust passage that open to the combustion chamber in synchronization with the rotation of the engine. And a variable valve mechanism, wherein the actual compression ratio at the time of self-ignition combustion is made different from the actual compression ratio at the time of spark ignition operation.

【０００６】具体的には、例えば請求項２記載の発明の
ように、自己着火燃焼時の実圧縮比を火花点火運転時の
実圧縮比よりも高くする。この場合、機関のボア径やピ
ストンのストローク、燃焼室の容積等は不変であり、燃
焼室回りの構造を複雑にする必要がないので、機関の耐
久性や燃焼ガスのシール性を容易に確保することができ
る。また、実圧縮比がそれぞれの燃焼状態に適するよう
に変更されるため、自己着火燃焼を行わせるときの圧縮
行程では、高い実圧縮比によって燃焼室内のガスが良好
に昇温され、火花点火燃焼を行わせるときには自己着火
燃焼時よりも低い実圧縮比によってノッキングの発生が
良好に抑制される。More specifically, the actual compression ratio during self-ignition combustion is made higher than the actual compression ratio during spark ignition operation. In this case, the bore diameter of the engine, the stroke of the piston, the volume of the combustion chamber, etc. are unchanged, and the structure around the combustion chamber does not need to be complicated, so that the durability of the engine and the sealing property of the combustion gas can be easily secured. can do. Further, since the actual compression ratio is changed so as to be suitable for each combustion state, in the compression stroke when performing the self-ignition combustion, the gas in the combustion chamber is satisfactorily heated by the high actual compression ratio, and spark ignition combustion is performed. Is performed, the occurrence of knocking is favorably suppressed by the actual compression ratio lower than that at the time of self-ignition combustion.

【０００７】詳しくは、請求項３記載の発明のように、
シリンダ略中央に配設された火花点火プラグと、燃焼室
に開口する吸気通路および排気通路と、機関の回転に同
期して前記吸気通路と排気通路とをそれぞれ開閉する吸
気弁および排気弁と、前記吸気弁の開閉時期を変更する
ことにより機関の実圧縮比を変更する可変動弁機構と、
既燃ガスの一部を燃焼室内に残留させる既燃ガス残留手
段と、を備え、所定の運転領域では、前記既燃ガス残留
手段により既燃ガスの一部を燃焼室内に残留させるとと
もに前記可変動弁機構により機関の実圧縮比を高めるこ
とで自己着火燃焼を行わせ、前記所定の運転領域以外の
運転領域では、前記既燃ガス残留手段による既燃ガスの
残留を減少させるとともに前記可変動弁機構により機関
の実圧縮比を低下させて前記火花点火プラグによる火花
点火燃焼を行わせるようにすることができる。自己着火
燃焼を行わせるときには、燃焼室内に残留した既燃ガス
が前述の高い圧縮比によって圧縮行程で良好に昇温さ
れ、これが火種となって安定した自己着火燃焼が実現さ
れる。More specifically, as in the third aspect of the present invention,
A spark ignition plug disposed substantially at the center of the cylinder, an intake passage and an exhaust passage opening to the combustion chamber, and an intake valve and an exhaust valve respectively opening and closing the intake passage and the exhaust passage in synchronization with rotation of the engine; A variable valve mechanism that changes the actual compression ratio of the engine by changing the opening / closing timing of the intake valve;
A burned gas residue means for causing a part of the burned gas to remain in the combustion chamber; and in a predetermined operating region, the burned gas residue means causes a part of the burned gas to remain in the combustion chamber and The self-ignition combustion is performed by increasing the actual compression ratio of the engine by the variable valve mechanism, and in an operation region other than the predetermined operation region, the residual burned gas by the burned gas residual means is reduced and the variable operation is performed. The actual compression ratio of the engine can be reduced by a valve mechanism to cause spark ignition combustion by the spark ignition plug. When the self-ignition combustion is performed, the burned gas remaining in the combustion chamber is satisfactorily heated in the compression stroke by the above-described high compression ratio, and this becomes an ignition source to realize stable self-ignition combustion.

【０００８】既燃ガスを燃焼室内に残留させるには、請
求項４記載の発明のように、第２の可変動弁機構によっ
て排気弁の閉じ時期を早めることにより実現される。あ
るいは、請求項５記載の発明のように、前記既燃ガス残
留手段を、前記排気通路とは独立に設けられた第２の排
気通路と、機関の排気行程と吸気行程とで前記第２の排
気通路を開く第２の排気弁と、機関の回転に関わらず前
記第２の排気通路を開閉可能な開閉手段と、から構成
し、前記開閉手段を開くことにより排気行程中に前記第
２の排気通路に排出された既燃ガスを吸気行程中に燃焼
室内に導入して既燃ガスの一部を燃焼室内に残留させる
ようにすることができる。この場合、吸気通路から燃焼
室内に導入された新気（混合気）と第２の排気通路から
燃焼室内に導入された既燃ガスとが燃焼室内で偏在する
ようになり、排気側から吸気側への自己着火が行われ
る。ここで燃焼室は、請求項６記載の発明のように、前
記吸気通路が開口する側と前記排気通路が開口する側と
が略対称形に形成された、いわゆるクロスフロー形式と
すると良い。これにより、新気（混合気）と既燃ガスと
が燃焼室内で成層化され、その境界面において、さらに
良好に自己着火が行われる。The burned gas remains in the combustion chamber by making the closing timing of the exhaust valve advanced by the second variable valve mechanism as in the invention described in claim 4. Alternatively, as in the invention as set forth in claim 5, the burned gas remaining means is divided into a second exhaust passage provided independently of the exhaust passage, and the second exhaust passage provided in the exhaust stroke and the intake stroke of the engine. A second exhaust valve for opening the exhaust passage, and opening / closing means capable of opening and closing the second exhaust passage regardless of the rotation of the engine. The opening / closing means opens the second exhaust valve during the exhaust stroke. The burned gas discharged to the exhaust passage can be introduced into the combustion chamber during the intake stroke so that a portion of the burned gas remains in the combustion chamber. In this case, fresh air (air-fuel mixture) introduced into the combustion chamber from the intake passage and burned gas introduced into the combustion chamber from the second exhaust passage are unevenly distributed in the combustion chamber. Self-ignition is performed. Here, the combustion chamber may be of a so-called cross-flow type in which the side where the intake passage opens and the side where the exhaust passage opens are formed substantially symmetrically. Thereby, the fresh air (air-fuel mixture) and the burned gas are stratified in the combustion chamber, and the self-ignition is more favorably performed at the boundary surface.

【０００９】また、可変動弁機構は、請求項７記載の発
明のように、前記吸気弁を駆動する吸気カムシャフトと
機関のクランクシャフトとの位相を変更することによ
り、前記所定の運転領域では前記吸気弁のバルブタイミ
ングを進角させて機関の実圧縮比を高め、前記所定の運
転領域以外の運転領域では前記吸気弁のバルブタイミン
グを遅角させて機関の実圧縮比を低下させることができ
る。The variable valve mechanism changes the phase of the intake camshaft for driving the intake valve and the phase of the crankshaft of the engine in the predetermined operating range. The actual compression ratio of the engine may be increased by advancing the valve timing of the intake valve, and the actual compression ratio of the engine may be decreased by retarding the valve timing of the intake valve in an operation region other than the predetermined operation region. it can.

【００１０】請求項８記載の発明では、前記所定の運転
領域とそれ以外の運転領域との間で機関の運転条件が変
化したときに、前記既燃ガス残留手段の作動時期と前記
可変動弁の作動時期とを異ならせるようにしている。既
燃ガスの残留量と圧縮比とはともに機関の燃焼に大きな
影響があり、これらの変更は適切なタイミングで行う必
要がある。通常、既燃ガス残留手段や可変動弁機構は瞬
時に切換えるようなものではなく、ある速度でもって作
動し、またこの速度が機関の状態で変化する場合もあ
る。自己着火燃焼と火花点火燃焼とを切換えるときにこ
のような２つの手段を同時に作動させると、切換開始か
ら完了までの間に予想し得ない既燃ガス残留量と圧縮比
の状態を通過することになるが、両者の作動時期を異な
らせることでこのような問題を生じることなく、円滑に
２つの燃焼状態を切換えることができる。According to the present invention, when the operating condition of the engine changes between the predetermined operating region and the other operating region, the operation timing of the burned gas residual means and the variable valve actuation are controlled. The operation timing is different. Both the residual amount of burned gas and the compression ratio have a great influence on the combustion of the engine, and these changes need to be made at an appropriate timing. Normally, the burned gas residual means and the variable valve mechanism are not switched instantaneously, but operate at a certain speed, and this speed may change depending on the state of the engine. If these two means are operated simultaneously when switching between self-ignition combustion and spark ignition combustion, it will pass through an unpredictable state of residual burned gas and compression ratio between the start and completion of the switch. However, by making the operation timings of the two different, it is possible to smoothly switch between the two combustion states without such a problem.

【００１１】また、既燃ガス残留手段の作動部が開閉手
段であり、可変動弁機構が吸気カムシャフトと機関のク
ランクシャフトとの位相を変更する機構である場合に
は、請求項９記載の発明のように、前記所定の運転領域
以外の運転領域から前記所定の運転領域へ機関の運転条
件が変化したときには前記吸気弁のバルブタイミングを
進角させた後に前記開閉手段を開き、前記所定の運転領
域からそれ以外の運転領域へ機関の運転条件が変化した
ときには前記開閉手段を閉じた後に前記吸気弁のバルブ
タイミングを遅角させるよう前記可変動弁機構と前記開
閉手段とを制御すると良い。なお、自己着火燃焼を行わ
せる所定の運転領域は、請求項１０記載の発明のよう
に、部分負荷領域に設定することができる。また、請求
項１１記載の発明のように、所定の運転領域の周囲にヒ
ステリシス領域を設定すると２つの燃焼状態の頻繁な切
換が抑制され、機関をより円滑に運転することができ
る。In the case where the operating portion of the burned gas residual means is an opening / closing means and the variable valve mechanism is a mechanism for changing a phase between an intake camshaft and a crankshaft of the engine, the present invention is further described in claim 9. As in the present invention, when the operating condition of the engine changes from an operating region other than the predetermined operating region to the predetermined operating region, the valve timing of the intake valve is advanced and then the opening / closing means is opened, and the predetermined When the operating condition of the engine changes from the operating region to another operating region, the variable valve mechanism and the opening / closing means may be controlled so as to delay the valve timing of the intake valve after closing the opening / closing means. In addition, the predetermined operation region in which the self-ignition combustion is performed can be set to the partial load region as in the tenth aspect of the present invention. Further, when the hysteresis region is set around the predetermined operation region, the frequent switching between the two combustion states is suppressed, and the engine can be operated more smoothly.

【００１２】[0012]

【発明の実施の形態】次に、本発明を火花点火式内燃機
関である４サイクル型の自動車用ガソリンエンジンに適
用した実施の形態を、添付図面に基づいて詳細に説明す
る。図１、２に示すように、シリンダブロック１０に
は、複数のシリンダ１２が直列に配置されており、その
上面を覆うように、シリンダヘッド１４が固定されてい
る。シリンダ１２内にはピストン１６が摺動可能に嵌合
しているとともに、シリンダヘッド１４の下面とピスト
ン１６上面との間に、いわゆるペントルーフ型の燃焼室
１８が形成されている。この燃焼室１８の一方の傾斜面
１８ａには第１吸気通路２０及び第２吸気通路２２が開
口しており、他方の傾斜面１８ｂに第１排気通路２４及
び第２排気通路２６が開口している。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a four-cycle type automobile gasoline engine which is a spark ignition type internal combustion engine will be described in detail with reference to the accompanying drawings. As shown in FIGS. 1 and 2, a plurality of cylinders 12 are arranged in series in a cylinder block 10, and a cylinder head 14 is fixed so as to cover an upper surface thereof. A piston 16 is slidably fitted in the cylinder 12, and a so-called pent roof type combustion chamber 18 is formed between the lower surface of the cylinder head 14 and the upper surface of the piston 16. A first intake passage 20 and a second intake passage 22 are opened on one inclined surface 18a of the combustion chamber 18, and a first exhaust passage 24 and a second exhaust passage 26 are opened on the other inclined surface 18b. I have.

【００１３】また、燃焼室１８には、第１，第２吸気通
路２０，２２との間をそれぞれ開閉する第１吸気弁２８
及び第２吸気弁３０と、第１，第２排気通路２４，２６
との間をそれぞれ開閉する第１排気弁３２及び第２排気
弁３４が設けられ、これら吸気弁２８，３０及び排気弁
３２，３４によって囲まれたシリンダ１２の略中心位置
に、点火プラグ３６が配設されている。吸気通路２０，
２２は、上流側で互いに合流しており、その合流部３８
に、電磁式の燃料噴射弁４０が設けられている。A first intake valve 28 for opening and closing the first and second intake passages 20 and 22 is provided in the combustion chamber 18.
And the second intake valve 30, and the first and second exhaust passages 24, 26
A first exhaust valve 32 and a second exhaust valve 34 are provided to open and close, respectively, and an ignition plug 36 is provided at a substantially central position of the cylinder 12 surrounded by the intake valves 28, 30 and the exhaust valves 32, 34. It is arranged. Intake passage 20,
22 are joined to each other on the upstream side,
, An electromagnetic fuel injection valve 40 is provided.

【００１４】第１，第２排気通路２４，２６は、それぞ
れシリンダヘッド１４内部に穿設された一対の排気ポー
トからシリンダヘッド１４に取り付けられる第１排気管
４２及び第２排気管４４の内部にわたって互いに独立し
て延びている。そして、第２排気管４４の途中には、第
２排気通路２６を開閉するバタフライバルブ型の制御弁
４６が介装されている。この制御弁４６は、シャフト４
８を介して図示せぬ駆動機構によって機関運転条件に応
じて開閉制御される。The first and second exhaust passages 24 and 26 extend from a pair of exhaust ports formed in the cylinder head 14 to the inside of a first exhaust pipe 42 and a second exhaust pipe 44 attached to the cylinder head 14. They extend independently of each other. In the middle of the second exhaust pipe 44, a butterfly valve type control valve 46 for opening and closing the second exhaust passage 26 is interposed. The control valve 46 is connected to the shaft 4
Opening / closing control is performed by a drive mechanism (not shown) via the control unit 8 in accordance with engine operating conditions.

【００１５】図３は、吸気弁２８，３０及び排気弁３
２，３４のバルブリフト特性を示している。これらの吸
気弁２８，３０及び排気弁３２，３４は、それぞれ機関
のクランクシャフトと同期して回転するカムのプロフィ
ールに応じて開閉作動する。FIG. 3 shows the intake valves 28 and 30 and the exhaust valve 3.
2 and 34 show valve lift characteristics. The intake valves 28, 30 and the exhaust valves 32, 34 open and close according to the profile of a cam that rotates in synchronization with the crankshaft of the engine.

【００１６】吸気弁２８，３０を駆動するカムシャフト
には、カムひねり機構５０が設けられており、カムシャ
フトと図示しないクランクシャフトとの回転位相を変更
することができる。このカムひねり機構５０の作動範囲
の一例を図４に示す。自己着火を起こすような高圧縮
比、例えば１４〜１８を実現する場合は、吸気バルブタ
イミング１となり、上死点ＴＤＣより前に吸気弁２８，
３０が開弁し、下死点ＢＤＣ付近で、吸気弁２８，３０
が閉弁する。自己着火が起きず、火花点火においてもノ
ッキングが起きないような低圧縮比、例えば１２以下、
を実現する場合は、吸気バルブタイミング２となり、上
死点ＴＤＣ付近で吸気弁２８，３０が開弁し、下死点Ｂ
ＤＣを大きく過ぎた角度で吸気弁２８，３０が閉弁する
よう構成されている。A cam twist mechanism 50 is provided on a camshaft for driving the intake valves 28 and 30 so that the rotational phase between the camshaft and a crankshaft (not shown) can be changed. FIG. 4 shows an example of the operation range of the cam twist mechanism 50. In the case of realizing a high compression ratio that causes self-ignition, for example, 14 to 18, the intake valve timing is 1 and the intake valves 28,
30 is opened, and the intake valves 28, 30 near the bottom dead center BDC.
Closes. A low compression ratio such that self-ignition does not occur and knocking does not occur even in spark ignition, for example, 12 or less,
Is realized, the intake valve timing 2 is reached, the intake valves 28 and 30 are opened near the top dead center TDC, and the bottom dead center B
The intake valves 28 and 30 are configured to close at an angle exceeding DC.

【００１７】各吸気弁２８，３０及び排気弁３２，３４
の開閉動作を図５、図６を参照して説明すると、図３
（イ）に示す第１排気弁３２は、排気行程（ａ）付近で
開作動し、その他の吸気行程（ｂ）、圧縮行程（ｃ）及
び膨張行程（ｄ）の付近では閉状態に制御されている。Each of the intake valves 28, 30 and the exhaust valves 32, 34
The opening / closing operation of FIG. 3 will be described with reference to FIGS.
The first exhaust valve 32 shown in (a) is opened near the exhaust stroke (a), and is controlled to be closed around the other intake strokes (b), compression strokes (c), and expansion strokes (d). ing.

【００１８】一方、図３（ロ）に示す第２排気弁３４
は、排気行程（ａ）及び吸気行程（ｂ）付近の両方で開
作動し、圧縮行程（ｃ）及び膨張行程（ｄ）付近では、
閉状態に制御される。つまり、第２排気弁３４は、通常
の第１排気弁３２とともに、排気行程（ａ）付近で開作
動するとともに、吸気弁２８，３０とともに吸気行程
（ｂ）付近で開作動し排気行程（ａ）から吸気行程
（ｂ）にまたがって開状態に保持されることとなる。On the other hand, the second exhaust valve 34 shown in FIG.
Opens in both the vicinity of the exhaust stroke (a) and the intake stroke (b), and in the vicinity of the compression stroke (c) and the expansion stroke (d),
It is controlled to the closed state. In other words, the second exhaust valve 34 opens with the normal first exhaust valve 32 near the exhaust stroke (a), and opens with the intake valves 28 and 30 near the intake stroke (b). ) To the open state over the intake stroke (b).

【００１９】また、吸気弁２８，３０は、図３（ハ）に
示すように、吸気行程（ｂ）付近で開作動し、その他の
排気行程（ａ）、圧縮行程（ｃ）及び膨張行程（ｄ）の
付近では、閉状態に制御される。つまり、吸気行程
（ｂ）では、両吸気弁２８，３０と、第２排気弁３４と
が同期して開作動する。As shown in FIG. 3C, the intake valves 28 and 30 are opened near the intake stroke (b), and the other exhaust strokes (a), compression strokes (c), and expansion strokes ( In the vicinity of d), the closed state is controlled. That is, in the intake stroke (b), the two intake valves 28 and 30 and the second exhaust valve 34 are opened synchronously.

【００２０】例えば図７に斜線の領域で示す部分負荷時
には、吸気弁２８，３０は図４の吸気バルブタイミング
１に設定されシリンダ１２内は、高圧縮比になる。この
時、図５に示すように、制御弁４６は開状態に制御さ
れ、自己着火燃焼が行われる。詳述すると、排気行程
（ａ）では、両方の排気通路２４，２６が開作動し、ピ
ストン１６の上昇に伴って燃焼室１８内の既燃ガスが両
排気通路２４，２６を通って排出される。続く吸気行程
（ｂ）では、上述したように吸気弁２８，３０及び第２
排気弁３４がともに開作動する。従って燃焼室１８に
は、ピストン１６の下降に伴って新気（混合気）Ｐが吸
気通路２０，２２側から導入されると同時に、第２排気
通路２６内に残留する既燃ガスＱが導入される。ここ
で、燃焼室１８は、いわゆるクロスフロー形式となって
おり、吸気通路２０，２２が開口する側と排気通路２
４，２６が開口する側とが略対称形に形成され、かつ、
ピストン１６の上面が略平面に形成されているため、吸
気通路２０，２２から導入される混合気Ｐがそのまま吸
気通路２０，２２側に残留し、第２排気通路２６から導
入される既燃ガスＱがそのまま排気通路２４，２６側に
残留する。従って、燃焼室１８内は、混合気Ｐと既燃ガ
スＱとが成層化した状態となる。なお、この吸気行程
（ｂ）では、第１排気弁３２（図３）は開状態となって
おり、第１排気通路２４内に残留する既燃ガスＱが燃焼
室１８へ逆流することはない。続く圧縮行程（ｃ）で
は、燃焼室１８内の混合気Ｐと既燃ガスＱとが成層化し
た状態で圧縮される。このため、燃焼室１８内に残留す
る既燃ガスＱの温度が、断熱圧縮の作用によって混合気
Ｐの発火温度を越えるまで上昇し、混合気Ｐと残留既燃
ガスＱとの界面において、残留既燃ガスＱから混合気Ｐ
への自己着火が行われる。そして膨張行程（ｄ）では、
爆発圧力によりピストン１６が下死点ＢＤＣ側へ押し下
げられて、再び排気行程（ａ）へと戻り、上述した動作
が繰り返される。For example, at the time of partial load indicated by the hatched area in FIG. 7, the intake valves 28 and 30 are set to the intake valve timing 1 in FIG. 4, and the inside of the cylinder 12 has a high compression ratio. At this time, as shown in FIG. 5, the control valve 46 is controlled to the open state, and self-ignition combustion is performed. More specifically, in the exhaust stroke (a), both the exhaust passages 24 and 26 are opened, and the burned gas in the combustion chamber 18 is discharged through the exhaust passages 24 and 26 as the piston 16 rises. You. In the subsequent intake stroke (b), as described above, the intake valves 28, 30 and the second
The exhaust valves 34 are both opened. Accordingly, fresh air (air-fuel mixture) P is introduced into the combustion chamber 18 from the intake passages 20 and 22 as the piston 16 descends, and at the same time, the burned gas Q remaining in the second exhaust passage 26 is introduced. Is done. Here, the combustion chamber 18 is of a so-called cross-flow type, and the side where the intake passages 20 and 22 open and the exhaust passage 2
The side where the openings 4 and 26 are opened is formed substantially symmetrically, and
Since the upper surface of the piston 16 is formed substantially flat, the air-fuel mixture P introduced from the intake passages 20 and 22 remains on the intake passages 20 and 22 side as it is, and the burned gas introduced from the second exhaust passage 26 Q remains on the exhaust passages 24 and 26 side as it is. Therefore, in the combustion chamber 18, the mixture P and the burned gas Q are stratified. In this intake stroke (b), the first exhaust valve 32 (FIG. 3) is in the open state, and the burned gas Q remaining in the first exhaust passage 24 does not flow back to the combustion chamber 18. . In the subsequent compression stroke (c), the air-fuel mixture P and the burned gas Q in the combustion chamber 18 are compressed in a stratified state. For this reason, the temperature of the burned gas Q remaining in the combustion chamber 18 rises by the action of the adiabatic compression until it exceeds the ignition temperature of the air-fuel mixture P, and at the interface between the air-fuel mixture P and the remaining burned gas Q, Mixture P from burned gas Q
Self-ignition is performed. And in the expansion stroke (d),
The piston 16 is pushed down to the bottom dead center BDC side by the explosion pressure, returns to the exhaust stroke (a) again, and the above-described operation is repeated.

【００２１】一方、機関の運転が部分負荷領域を外れた
場合には、吸気弁２８，３０は図４の吸気バルブタイミ
ング２に示すように設定され、シリンダ１２内は、自己
着火が起きずノッキングも起きない低圧縮比になる。こ
の際、図２に示すように、制御弁４６は全開状態に制御
され、シリンダ１２内に均質な混合気Ｐを形成して点火
する均質燃焼が行われる。詳述すると、排気行程（ａ）
では第１排気通路２４（図３）を通って燃焼室１８内の
既燃ガスＱが排出され、吸気行程（ｂ）では両吸気弁２
８，３０が開状態となり、両吸気通路２０，２２から混
合気Ｐが燃焼室１８内に導入される。このとき、制御弁
４６が開状態となっているから、第２排気通路２６から
既燃ガスＱが導入されることはない。続く圧縮行程
（ｃ）で圧縮された混合気Ｐは点火プラグ３６で着火さ
れ、膨張行程（ｄ）では爆発圧力によりピストン１６が
押し下げられる。On the other hand, when the operation of the engine is out of the partial load region, the intake valves 28 and 30 are set as shown in the intake valve timing 2 in FIG. And a low compression ratio that does not occur. At this time, as shown in FIG. 2, the control valve 46 is controlled to a fully open state, and a homogeneous mixture P is formed in the cylinder 12 to perform homogeneous combustion for ignition. Specifically, the exhaust stroke (a)
Then, the burned gas Q in the combustion chamber 18 is discharged through the first exhaust passage 24 (FIG. 3), and in the intake stroke (b), the two intake valves 2
8 and 30 are opened, and the air-fuel mixture P is introduced into the combustion chamber 18 from both the intake passages 20 and 22. At this time, the burned gas Q is not introduced from the second exhaust passage 26 because the control valve 46 is in the open state. The air-fuel mixture P compressed in the subsequent compression stroke (c) is ignited by the ignition plug 36, and in the expansion stroke (d), the piston 16 is pushed down by the explosion pressure.

【００２２】ここで、自己着火領域と火花点火領域の両
領域間の移行について述べる。図８に示すように、加速
時など、部分負荷の自己着火領域から、負荷や回転が増
大し、火花点火運転領域に移行する場合は、その判定負
荷と回転数とを、その反対の減速時の場合よりも、高く
する。これにより、この負荷と回転付近の運転時におい
て、負荷と回転とが変動する際、頻繁に自己着火と均質
燃焼が変化するのを防ぐことができる。機関の運転の円
滑、安定を実現でき、かつ、作動機構の耐久性も向上で
きる。The transition between the self-ignition region and the spark ignition region will now be described. As shown in FIG. 8, when the load or rotation increases from the self-ignition region of the partial load, such as during acceleration, and shifts to the spark ignition operation region, the determination load and the rotation speed are set to the opposite during deceleration. Higher than the case. Thereby, when the load and the rotation fluctuate during the operation near the load and the rotation, it is possible to prevent the self-ignition and the homogeneous combustion from frequently changing. The smooth and stable operation of the engine can be realized, and the durability of the operating mechanism can be improved.

【００２３】また、図９に示すように、負荷と回転数と
があらかじめ定められた自己着火領域になった場合に
も、その後一定の時間、負荷や回転が略一定になってい
るかどうかを確認後、自己着火運転に移行することも考
えられる。これにより、急激なアクセルペダルの開閉や
エンジン回転の上下により、頻繁に自己着火と火花点火
とを切換えることが防止され、安定した運転が期待でき
る。この際、自己着火運転に入った後、負荷や回転が高
くなり火花点火運転に移行する際は、このような略一定
の運転かどうかの確認をせず、即座に火花点火運転に移
行する。これにより、負荷増大の応答性を高くすること
ができ、加速等のときのレスポンスを向上できる。Also, as shown in FIG. 9, even when the load and the number of revolutions reach a predetermined self-ignition region, it is checked whether the load and the revolution are substantially constant for a certain period of time thereafter. Later, it is conceivable to shift to the self-ignition operation. This prevents frequent switching between self-ignition and spark ignition due to sudden opening / closing of the accelerator pedal and up / down of engine rotation, and stable operation can be expected. At this time, after the self-ignition operation is started, when the load or rotation becomes high and the operation shifts to the spark ignition operation, the operation immediately shifts to the spark ignition operation without confirming whether the operation is substantially constant. As a result, it is possible to increase the responsiveness of the load increase and improve the response at the time of acceleration or the like.

【００２４】このような、自己着火と火花点火の運転領
域の切換えの際、圧縮比を制御する吸気カムひねり機構
５０と、燃焼室１８内に残留させる既燃ガスＱの量を制
御する制御弁４６の作動について述べる。基本的には、
自己着火領域は部分負荷なので、吸気管負圧が低く、シ
リンダ１２内の圧力も低いため、圧縮比を高めても残留
ガスが少ない限り、ノッキングは起こりにくい。また、
既燃ガスＱが大量にシリンダ１２に流入すると、圧縮比
が自己着火が起こるような１４以下である場合には、火
花点火運転しなくてはいけないが、このような大量の残
留既燃ガスＱがある場合は、燃焼が不安定となりがちで
エンジンの運転が不安定がちとなり、長い時間この状態
にエンジンがあることは好ましくない。従って、火花点
火運転領域から自己着火運転領域に移行する際は、図１
０に示すように、まず、時間のかかる吸気弁２８，３０
のひねりを先行させ、圧縮比が高くなってから、応答速
度の早い制御弁４６を開けて既燃ガスＱをシリンダ１２
内に導入すると、移行の際のノッキングの発生や、燃焼
の不安定が抑制されて、移行が円滑に、安定に行うこと
ができる。つまり、システム応答速度の劣る圧縮比を先
に高めてから、その後、システム応答速度の早い内部Ｅ
ＧＲガスを導入するように、カムひねり機構５０と、制
御弁４６の作動を制御する。その後、自己着火が確認さ
れれば、図示しないが、点火プラグ３６を休止してもよ
い。When switching between the operation ranges of the self-ignition and the spark ignition, the intake cam twist mechanism 50 for controlling the compression ratio and the control valve for controlling the amount of the burned gas Q remaining in the combustion chamber 18 are provided. The operation of 46 will be described. Basically,
Since the auto-ignition region is a partial load, the intake pipe negative pressure is low and the pressure in the cylinder 12 is low. Therefore, even if the compression ratio is increased, knocking does not easily occur as long as the residual gas is small. Also,
If a large amount of the burned gas Q flows into the cylinder 12, if the compression ratio is 14 or less at which auto-ignition occurs, the spark ignition operation must be performed. If there is, the combustion tends to be unstable and the operation of the engine tends to be unstable, and it is not preferable that the engine remains in this state for a long time. Therefore, when shifting from the spark ignition operation region to the self-ignition operation region, FIG.
First, as shown in FIG.
After the compression ratio is increased, the control valve 46 having a fast response speed is opened to burn the burned gas Q into the cylinder 12.
When it is introduced inside, the occurrence of knocking at the time of transition and the instability of combustion are suppressed, and the transition can be performed smoothly and stably. That is, after increasing the compression ratio, which is inferior to the system response speed, first, the internal E, which has a high system response speed, is increased.
The cam twist mechanism 50 and the operation of the control valve 46 are controlled so as to introduce the GR gas. Thereafter, if self-ignition is confirmed, the ignition plug 36 may be stopped (not shown).

【００２５】反対に、自己着火領域から火花点火運転領
域に移行する際は、図示しないが、図１０で示したこの
順番とは逆にする。つまり、まず火花点火を再開し、つ
いで既燃ガスＱのシリンダ１２内への流入を止め、その
後、カムひねり機構５０により、圧縮比を低下させる。
これにより、加速開始直後の既燃ガスＱによる火花点火
時の燃焼不安定が抑制されるとともに、高圧縮比のまま
残留既燃ガスＱがなくなることによりトルクが増大し、
加速感の向上が得られる。その後は吸気側のスロットル
の開度が開くことが現れて吸気量自体が増大するので、
低圧縮比でも出力を増大できる。Conversely, when shifting from the self-ignition region to the spark ignition operation region, although not shown, the order shown in FIG. 10 is reversed. That is, first, spark ignition is restarted, and then the inflow of the burned gas Q into the cylinder 12 is stopped. Then, the compression ratio is reduced by the cam twist mechanism 50.
As a result, combustion instability at the time of spark ignition by the burned gas Q immediately after the start of acceleration is suppressed, and the torque is increased by eliminating the remaining burned gas Q at a high compression ratio,
The feeling of acceleration is improved. After that, the opening of the throttle on the intake side opens and the intake air amount itself increases,
The output can be increased even at a low compression ratio.

【００２６】以上のように、本実施の形態にかかる４ス
トローク型の火花点火式エンジンでは、部分負荷時にお
ける実圧縮比が高く設定され、しかも、吸気行程（ｂ）
の際に、第２排気通路２６に残留する既燃ガスＱが燃焼
室１８へ導入されるため、燃焼室１８内で既燃ガスＱ側
から混合気Ｐへの自己着火が可能となり、良好な自己着
火燃焼が実現される。この結果、従来のように吸気通路
の途中に設けられたスロットル弁によって、部分負荷時
に吸入される新気の量を制限する必要がないため、吸入
負圧に起因するポンピングロスの低減が可能となる。As described above, in the four-stroke spark ignition engine according to the present embodiment, the actual compression ratio at the time of partial load is set high, and the intake stroke (b)
At this time, the burned gas Q remaining in the second exhaust passage 26 is introduced into the combustion chamber 18, so that the self-ignition from the burned gas Q side to the air-fuel mixture P in the combustion chamber 18 becomes possible, Self-ignition combustion is realized. As a result, there is no need to limit the amount of fresh air sucked at the time of partial load by the throttle valve provided in the middle of the intake passage as in the related art, so that it is possible to reduce the pumping loss caused by the suction negative pressure. Become.

【００２７】また、部分負荷以外の運転領域において
は、圧縮比を低くし、制御弁４６を閉じて第２排気通路
２６を遮断することにより、上述したように吸気行程
（ｂ）で既燃ガスＱが第２排気通路２６から燃焼室１８
へ導入されることはなく、ノッキングを抑制でき、十分
に良好な出力を得ることができる。In the operating range other than the partial load, the compression ratio is lowered, the control valve 46 is closed, and the second exhaust passage 26 is shut off, so that the burned gas is reduced in the intake stroke (b) as described above. Q from the second exhaust passage 26 to the combustion chamber 18
, Knocking can be suppressed, and a sufficiently good output can be obtained.

【００２８】また、自己着火領域と火花点火領域との切
換えの際、火花点火から自己着火に切換える際は、まず
圧縮比を高め、ついで、既燃ガスＱを導入するよう、カ
ムひねり機構５０と制御弁４６の作動に時間差を設けた
ので、既燃ガスＱによる火花点火時の燃焼不安定が抑制
され、エンジンの円滑な安定な運転が実現できる。ま
た、自己着火から火花点火に移行する際は、その逆で、
まず燃焼室１８内への既燃ガスＱの導入を止め、ついで
圧縮比を低くするので、既燃ガスＱ存在下での火花点火
燃焼が少なく、しかも、高圧縮比のまま残留ガスの少な
い火花点火になるので、トルクも増大し、加速感の向上
が得られる。つまり本実施の形態では、部分負荷時にお
ける自己着火燃焼と高負荷時における均質燃焼とを高度
に両立させることができる。Further, when switching between the self-ignition region and the spark ignition region, when switching from spark ignition to self-ignition, the compression ratio is first increased, and then the cam twist mechanism 50 is introduced so that the burned gas Q is introduced. Since a time difference is provided in the operation of the control valve 46, unstable combustion during spark ignition due to the burned gas Q is suppressed, and a smooth and stable operation of the engine can be realized. When switching from self-ignition to spark ignition, the reverse is true.
First, the introduction of the burned gas Q into the combustion chamber 18 is stopped, and then the compression ratio is lowered, so that spark ignition combustion in the presence of the burned gas Q is small, and furthermore, there is little residual gas with a high compression ratio. Since the ignition occurs, the torque is also increased, and the feeling of acceleration is improved. That is, in the present embodiment, the self-ignition combustion at the time of the partial load and the homogeneous combustion at the time of the high load can both be highly compatible.

【００２９】なお、本実施の形態は、排気弁（第１排気
弁３２、第２排気弁３４）を２弁設け、片方の排気弁
（第２排気弁３４）を吸気行程にも開状態とし、排気通
路の開閉弁により燃焼室１８内に残留する既燃ガスＱを
制御するような自己着火機構を用いて説明したが、本発
明はこれに限定されるものではなく、例えば、排気側に
も可変動弁機構を設けて排気弁の閉じ時期を早めること
により既燃ガスＱの一部を燃焼室内に残留させるものに
適用しても良い。さらには、残留既燃ガスＱの制御によ
って自己着火を制御するものに限定されるものでもな
く、要するに、自己着火燃焼と火花点火燃焼とを両立さ
せる際に圧縮比を変更しようとする機関には全て適用可
能である。In this embodiment, two exhaust valves (the first exhaust valve 32 and the second exhaust valve 34) are provided, and one of the exhaust valves (the second exhaust valve 34) is also opened during the intake stroke. Although the self-ignition mechanism in which the burned gas Q remaining in the combustion chamber 18 is controlled by the on-off valve of the exhaust passage has been described, the present invention is not limited to this. Alternatively, the present invention may be applied to a system in which a portion of the burned gas Q is left in the combustion chamber by providing a variable valve mechanism to advance the closing timing of the exhaust valve. Furthermore, the present invention is not limited to the one that controls self-ignition by controlling the residual burned gas Q. In short, an engine that attempts to change the compression ratio when achieving both self-ignition combustion and spark ignition combustion is required. All are applicable.

【００３０】また、実圧縮比を変更する可変動弁機構と
して吸気カムシャフトと機関のクランクシャフトとの位
相を変更する機構を用いているが、２種類以上のカムを
切換えてバルブリフト特性を変更する動弁系やクランク
シャフトに対するカムシャフトの角速度を変更して開弁
機関を連続的に変更可能な動弁系、電磁力あるいは油圧
によって開閉時期を自由に制御することが可能な動弁系
等を使用しても良いことはもちろんである。Although a mechanism for changing the phase between the intake camshaft and the engine crankshaft is used as a variable valve mechanism for changing the actual compression ratio, two or more kinds of cams are switched to change the valve lift characteristics. Valve system that can continuously change the valve opening engine by changing the angular velocity of the camshaft with respect to the crankshaft, valve system that can freely control the opening and closing timing by electromagnetic force or hydraulic pressure, etc. Of course, you can use.

【００３１】[0031]

【発明の効果】以上のように、本発明によれば、自己着
火燃焼と火花点火燃焼の両方の燃焼とも良好に行わせる
ことができるとともに、機関の耐久性や燃焼ガスのシー
ル性を容易に確保することができる。As described above, according to the present invention, both the self-ignition combustion and the spark ignition combustion can be favorably performed, and the durability of the engine and the sealing property of the combustion gas can be easily improved. Can be secured.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明実施の形態の構成例の一例を示す図であ
る。FIG. 1 is a diagram illustrating an example of a configuration example according to an embodiment of the present invention.

【図２】実施の形態の構成例の一例を示す図である。FIG. 2 is a diagram illustrating an example of a configuration example of an embodiment.

【図３】実施の形態の吸気弁と排気弁の作動の一例を示
す図である。FIG. 3 is a diagram illustrating an example of an operation of an intake valve and an exhaust valve according to the embodiment;

【図４】実施の形態の自己着火時と火花点火時との吸気
可変動弁の作動例を示す図である。FIG. 4 is a diagram illustrating an operation example of an intake variable valve in self-ignition and spark ignition according to the embodiment;

【図５】実施の形態の部分負荷の動作を示す図である。FIG. 5 is a diagram illustrating an operation of a partial load according to the embodiment.

【図６】実施の形態の高負荷時の動作を示す図である。FIG. 6 is a diagram illustrating an operation at the time of a high load according to the embodiment;

【図７】実施の形態の自己着火運転領域を示す図であ
る。FIG. 7 is a diagram showing a self-ignition operation region according to the embodiment.

【図８】実施の形態の加減速時の自己着火判断領域の一
例を示す図である。FIG. 8 is a diagram illustrating an example of a self-ignition determination area during acceleration / deceleration according to the embodiment;

【図９】実施の形態の自己着火燃焼指示のその他の一例
を示す図である。FIG. 9 is a diagram showing another example of the self-ignition combustion instruction of the embodiment.

【図１０】実施の形態の自己着荷領域への移行時のバル
ブひねりと排気制御弁の動きの一例を示す図である。FIG. 10 is a diagram illustrating an example of a valve twist and a movement of an exhaust control valve when shifting to a self-loading region according to the embodiment.

【符号の説明】[Explanation of symbols]

１０ シリンダブロック １２ シリンダ １４ シリンダヘッド １６ ピストン １８ 燃焼室 １８ａ 傾斜面 １８ｂ 傾斜面 ２０ 第１吸気通路 ２２ 第２吸気通路 ２４ 第１排気通路 ２６ 第２排気通路 ２８ 第１吸気弁 ３０ 第２吸気弁 ３２ 第１排気弁 ３４ 第２排気弁 ３６ 点火プラグ ３８ 合流部 ４０ 燃料噴射弁 ４２ 第１排気管 ４４ 第２排気管 ４６ 制御弁 ４８ シャフト ５０ カムひねり機構 Reference Signs List 10 cylinder block 12 cylinder 14 cylinder head 16 piston 18 combustion chamber 18a inclined surface 18b inclined surface 20 first intake passage 22 second intake passage 24 first exhaust passage 26 second exhaust passage 28 first intake valve 30 second intake valve 32 First exhaust valve 34 Second exhaust valve 36 Ignition plug 38 Merging section 40 Fuel injection valve 42 First exhaust pipe 44 Second exhaust pipe 46 Control valve 48 Shaft 50 Cam twist mechanism

Claims (11)

【特許請求の範囲】[Claims] 【請求項１】 所定の運転領域で自己着火燃焼を行わ
せ、前記所定の運転領域以外の運転領域で火花点火燃焼
を行わせる火花点火式内燃機関において、 機関の回転に同期して燃焼室に開口する吸気通路および
排気通路をそれぞれ開閉する吸気弁および排気弁と、前
記吸気弁の開閉時期を変更することにより機関の実圧縮
比を変更する可変動弁機構と、を備え、 この可変動弁機構により、自己着火燃焼時の実圧縮比と
火花点火運転時の実圧縮比とを異ならせることを特徴と
する火花点火式内燃機関。1. A spark ignition type internal combustion engine in which self-ignition combustion is performed in a predetermined operation region and spark ignition combustion is performed in an operation region other than the predetermined operation region. An intake valve and an exhaust valve that respectively open and close the open intake passage and the exhaust passage; and a variable valve mechanism that changes the actual compression ratio of the engine by changing the opening and closing timing of the intake valve. A spark ignition type internal combustion engine characterized in that an actual compression ratio during self-ignition combustion is made different from an actual compression ratio during spark ignition operation by a mechanism. 【請求項２】 自己着火燃焼時の実圧縮比を火花点火運
転時の実圧縮比よりも高くすることを特徴とする請求項
１記載の火花点火式内燃機関。2. The spark ignition type internal combustion engine according to claim 1, wherein the actual compression ratio during self-ignition combustion is higher than the actual compression ratio during spark ignition operation. 【請求項３】 シリンダ略中央に配設された火花点火プ
ラグと、 燃焼室に開口する吸気通路および排気通路と、 機関の回転に同期して前記吸気通路と排気通路とをそれ
ぞれ開閉する吸気弁および排気弁と、 前記吸気弁の開閉時期を変更することにより機関の実圧
縮比を変更する可変動弁機構と、 既燃ガスの一部を燃焼室内に残留させる既燃ガス残留手
段と、を備え、 所定の運転領域では、前記既燃ガス残留手段により既燃
ガスの一部を燃焼室内に残留させるとともに前記可変動
弁機構により機関の実圧縮比を高めることで自己着火燃
焼を行わせ、前記所定の運転領域以外の運転領域では、
前記既燃ガス残留手段による既燃ガスの残留を減少させ
るとともに前記可変動弁機構により機関の実圧縮比を低
下させて前記火花点火プラグによる火花点火燃焼を行わ
せることを特徴とする火花点火式内燃機関。3. A spark ignition plug disposed substantially in the center of a cylinder, an intake passage and an exhaust passage opening to a combustion chamber, and an intake valve for opening and closing the intake passage and the exhaust passage in synchronization with rotation of the engine. And an exhaust valve; a variable valve mechanism that changes the actual compression ratio of the engine by changing the opening / closing timing of the intake valve; and a burned gas residual unit that leaves a portion of the burned gas in the combustion chamber. In a predetermined operation region, the burned gas residual means causes a part of the burned gas to remain in the combustion chamber, and the variable valve mechanism increases the actual compression ratio of the engine to perform self-ignition combustion, In operation regions other than the predetermined operation region,
A spark ignition type wherein the remaining burned gas by the burned gas residual means is reduced, and the actual compression ratio of the engine is reduced by the variable valve mechanism to perform spark ignition combustion by the spark ignition plug. Internal combustion engine. 【請求項４】 前記既燃ガス残留手段は、前記排気弁の
閉じ時期を早めることにより既燃ガスの一部を燃焼室内
に残留させる第２の可変動弁機構であることを特徴とす
る請求項３記載の火花点火式内燃機関。4. The burned gas residual means is a second variable valve mechanism that causes a portion of burned gas to remain in a combustion chamber by accelerating a closing timing of the exhaust valve. Item 4. A spark ignition type internal combustion engine according to item 3. 【請求項５】 前記既燃ガス残留手段は、前記排気通路
とは独立に設けられた第２の排気通路と、機関の排気行
程と吸気行程とで前記第２の排気通路を開く第２の排気
弁と、機関の回転に関わらず前記第２の排気通路を開閉
可能な開閉手段と、からなり、前記開閉手段を開くこと
により排気行程中に前記第２の排気通路に排出された既
燃ガスを吸気行程中に燃焼室内に導入して既燃ガスの一
部を燃焼室内に残留させることを特徴とする請求項３記
載の火花点火式内燃機関。5. The burned gas remaining means includes a second exhaust passage provided independently of the exhaust passage, and a second exhaust passage that opens the second exhaust passage during an exhaust stroke and an intake stroke of an engine. An exhaust valve, and opening and closing means capable of opening and closing the second exhaust passage irrespective of rotation of the engine, and opening the opening and closing means to release the burned combusted gas discharged into the second exhaust passage during an exhaust stroke. 4. The spark ignition type internal combustion engine according to claim 3, wherein the gas is introduced into the combustion chamber during an intake stroke, and a part of the burned gas remains in the combustion chamber. 【請求項６】 前記燃焼室は、前記吸気通路が開口する
側と前記排気通路が開口する側とが略対称形に形成され
ることを特徴とする請求項５記載の火花点火式内燃機
関。6. The spark ignition type internal combustion engine according to claim 5, wherein the combustion chamber is formed such that a side where the intake passage opens and a side where the exhaust passage opens are substantially symmetrical. 【請求項７】 前記可変動弁機構は、前記吸気弁を駆動
する吸気カムシャフトと機関のクランクシャフトとの位
相を変更することにより、前記所定の運転領域では前記
吸気弁のバルブタイミングを進角させて機関の実圧縮比
を高め、前記所定の運転領域以外の運転領域では前記吸
気弁のバルブタイミングを遅角させて機関の実圧縮比を
低下させることを特徴とする請求項５または６記載の火
花点火式内燃機関。7. The variable valve mechanism advances a valve timing of the intake valve in the predetermined operation region by changing a phase between an intake camshaft that drives the intake valve and a crankshaft of an engine. 7. The actual compression ratio of the engine is increased by increasing the actual compression ratio of the engine, and in an operation region other than the predetermined operation region, the valve timing of the intake valve is retarded to decrease the actual compression ratio of the engine. Spark ignition type internal combustion engine. 【請求項８】 前記所定の運転領域とそれ以外の運転領
域との間で機関の運転条件が変化したときに、前記既燃
ガス残留手段の作動時期と前記可変動弁の作動時期とを
異ならせることを特徴とする請求項３から７のいずれか
に記載の火花点火式内燃機関。8. When the operating condition of the engine is changed between the predetermined operating region and the other operating region, the operating timing of the burned gas residual means and the operating timing of the variable valve are different. The spark ignition type internal combustion engine according to any one of claims 3 to 7, wherein 【請求項９】 前記所定の運転領域以外の運転領域から
前記所定の運転領域へ機関の運転条件が変化したときに
は前記吸気弁のバルブタイミングを進角させた後に前記
開閉手段を開き、前記所定の運転領域からそれ以外の運
転領域へ機関の運転条件が変化したときには前記開閉手
段を閉じた後に前記吸気弁のバルブタイミングを遅角さ
せるよう前記可変動弁機構と前記開閉手段とを制御する
ことを特徴とする請求項７記載の火花点火式内燃機関。9. When the operating condition of the engine changes from an operating region other than the predetermined operating region to the predetermined operating region, the valve timing of the intake valve is advanced and then the opening / closing means is opened, When the operating condition of the engine changes from the operating region to the other operating region, controlling the variable valve mechanism and the opening / closing means so as to delay the valve timing of the intake valve after closing the opening / closing means. The spark ignition type internal combustion engine according to claim 7, characterized in that: 【請求項１０】 前記所定の運転領域は部分負荷領域に
設定されることを特徴とする請求項１から９のいずれか
に記載の火花点火式内燃機関。10. The spark ignition type internal combustion engine according to claim 1, wherein the predetermined operation region is set to a partial load region. 【請求項１１】 前記所定の運転領域の周囲にヒステリ
シス領域を設定することを特徴とする請求項１から１０
のいずれかに記載の火花点火式内燃機関。11. A hysteresis area is set around the predetermined operation area.
The spark ignition type internal combustion engine according to any one of the above.
JP08576798A 1998-03-31 1998-03-31 Spark ignition internal combustion engine Expired - Fee Related JP4019492B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP08576798A JP4019492B2 (en) 1998-03-31 1998-03-31 Spark ignition internal combustion engine

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Application Number Priority Date Filing Date Title
JP08576798A JP4019492B2 (en) 1998-03-31 1998-03-31 Spark ignition internal combustion engine

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Publication Number Publication Date
JPH11280504A true JPH11280504A (en) 1999-10-12
JP4019492B2 JP4019492B2 (en) 2007-12-12

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ID=13868035

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1455063A1 (en) 2003-03-03 2004-09-08 Toyota Jidosha Kabushiki Kaisha Variable cycle engine and operation mode switching method
JP2005330842A (en) * 2004-05-18 2005-12-02 Toyota Industries Corp Internal combustion engine
EP1234961A3 (en) * 2001-02-27 2007-05-30 Fuji Jukogyo Kabushiki Kaisha Combustion control apparatus for engine
JP2011153562A (en) * 2010-01-27 2011-08-11 Mazda Motor Corp Control device of spark ignition engine
JP2014224462A (en) * 2013-05-15 2014-12-04 日産自動車株式会社 Control device and control method for internal combustion engine

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1234961A3 (en) * 2001-02-27 2007-05-30 Fuji Jukogyo Kabushiki Kaisha Combustion control apparatus for engine
EP1455063A1 (en) 2003-03-03 2004-09-08 Toyota Jidosha Kabushiki Kaisha Variable cycle engine and operation mode switching method
US6971338B2 (en) 2003-03-03 2005-12-06 Toyota Jidosha Kabushiki Kaisha Variable cycle engine and operation mode switching method
JP2005330842A (en) * 2004-05-18 2005-12-02 Toyota Industries Corp Internal combustion engine
JP2011153562A (en) * 2010-01-27 2011-08-11 Mazda Motor Corp Control device of spark ignition engine
JP2014224462A (en) * 2013-05-15 2014-12-04 日産自動車株式会社 Control device and control method for internal combustion engine

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