JPS59231115A - Valve mechanism of internal-combustion engine - Google Patents

Valve mechanism of internal-combustion engine

Info

Publication number
JPS59231115A
JPS59231115A JP10429983A JP10429983A JPS59231115A JP S59231115 A JPS59231115 A JP S59231115A JP 10429983 A JP10429983 A JP 10429983A JP 10429983 A JP10429983 A JP 10429983A JP S59231115 A JPS59231115 A JP S59231115A
Authority
JP
Japan
Prior art keywords
valve
rocker arm
cam
arm
lift
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10429983A
Other languages
Japanese (ja)
Inventor
Nobuo Habu
土生　信男
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.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
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 Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP10429983A priority Critical patent/JPS59231115A/en
Publication of JPS59231115A publication Critical patent/JPS59231115A/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

PURPOSE:To enable to control the valve lift by a method wherein the surface of a rocker arm, which slides under contacting with a cam and the end part of a valve stem, is made in a circular arc surface centering around an axis parallel to a cam shaft and the rocker arm is rockingly supported by means of an arm pivoting around said axis. CONSTITUTION:The sliding surface 12 of a rocker arm 6, which slides under contacting with the cap 16 of a suction valve 5 and a cam 1, is formed in a circular arc surface centering around the axis center of a supporting shaft 9 parallel to a camshaft 2. The rocker arm 6 is mounted slidably with respect to the pivoting shaft 8 of an arm 7 fixed onto the supporting shaft 9 so as to transmit the lift of the cam 1 to the suction valve 5. The supporting shaft 9 is turned in response to the engine load so that the pivoting shaft 8 is shifted centering around the axis center of the supporting shaft 9 so as to change the arm ratio of the rocker arm 6 and consequently to control the lift of the suction valve 5 in order to enable to form the turbulence of combustion air corresponding to the engine load in a combustion chamber.

Description

【発明の詳細な説明】 技術分野 本発明は機関負荷に応じてバルブリフトを変化させるこ
とのできる内燃機関の動弁機構に関する。DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a valve operating mechanism for an internal combustion engine that can change valve lift in accordance with engine load.

従来技術 従来の動弁機構を用いた内燃機関では、吸入中（１） 気量が少い軽負荷領域における吸気乱れが小さいために
、高負荷領域におけるよりも燃焼が悪く、空燃比をさら
にリーン側に設定する際のネックとなっている。吸気ボ
ートや燃焼室の形状の改善により燃焼を改善する対策も
当然実施されているが、このような対策では、低負荷領
域から高負荷領域に亘る広範な領域全てに満足のいく結
果を得ることが難しく、吸気弁の作動を機関負荷状態に
応じて変化させる試みが提案されるに至っている。Prior Art In an internal combustion engine using a conventional valve mechanism, during intake (1), combustion is worse than in high load areas due to small intake air turbulence in the light load area where the air volume is small, and the air-fuel ratio is made leaner. This is a problem when setting it on the side. Naturally, measures have been taken to improve combustion by improving the shape of the intake boat and combustion chamber, but such measures cannot produce satisfactory results in a wide range of conditions, from low load to high load. This has led to proposals to change the operation of the intake valve according to the engine load condition.

特開昭箱５５−１３７３０５号公報に、バルブリフトを
可変とする構成例が示されている。この例においては、
カムとバルブとの間にロッカーアームと揺動カムとが配
設され、これらの部材間は全て面接触することによって
カムの運動がバルブに伝達されるようになっている。ロ
ッカーアームの回転軸線がバルブ軸線に対して直角方向
に移動することによりバルブリフトが変化される。この
ような構成ではタペットクリアランスが太き（なって信
頼性に欠け、それぞれの要素の相互の接触面角度が大き
く変化するために運動の伝達がスムーズでな（２） く且つ早期に摩耗することになる。Japanese Patent Laid-Open No. 55-137305 discloses an example of a configuration in which the valve lift is variable. In this example,
A rocker arm and a swinging cam are disposed between the cam and the valve, and the movement of the cam is transmitted to the valve by making surface contact between these members. The valve lift is changed by moving the rotational axis of the rocker arm in a direction perpendicular to the valve axis. In such a configuration, the tappet clearance is large (and therefore unreliable), and the mutual contact surface angle of each element changes greatly, resulting in poor transmission of motion (2) and premature wear. become.

発明の目的 本発明の目的はカムの運動を確実にバルブに伝達するこ
とができ、且つ機関負荷に応じてバルブリフトを変化さ
せることのできる内燃機関の動弁機構を得ることにある
。OBJECTS OF THE INVENTION An object of the present invention is to provide a valve operating mechanism for an internal combustion engine that can reliably transmit the motion of a cam to a valve and can change the valve lift in accordance with the engine load.

発明の構成 本発明による内燃機関の動弁機構は、カムとバルブとの
間で運動を伝達するロッカーアームがカム軸と平行な回
転軸線を有する支持部材に枢着され、この支持部材はカ
ム軸と平行に延びる支持軸に取付けられ、上記ロッカー
アームのカムに当接する面の輪郭及びバルブに当接する
面の輪郭が支持軸の軸線を中心とする円の円弧により形
成され、さらに上記支持軸を機関負荷に応じて所定角度
だけ回動せしめる駆動装置が設けられ、上記支持軸の回
動によりバルブリフトが変化するようにしたことを特徴
とする。Structure of the Invention In the valve operating mechanism for an internal combustion engine according to the present invention, a rocker arm that transmits motion between a cam and a valve is pivotally mounted to a support member having a rotation axis parallel to the camshaft. The contour of the surface of the rocker arm that contacts the cam and the contour of the surface that contacts the valve are formed by an arc of a circle centered on the axis of the support shaft; The present invention is characterized in that a drive device is provided to rotate the valve by a predetermined angle in accordance with the engine load, and the valve lift is changed by the rotation of the support shaft.

実施例 以下本発明を実施例について図面を参照して説（３） 明する。Example The present invention will be described below with reference to the drawings in terms of embodiments (3). I will clarify.

第１図には本発明による内燃機関の動弁機構の実施例が
示されている。周知のカム１がカム軸２に取付けられて
いる。シリンダヘッド３−は吸気ボート４が形成され、
吸気バルブ５が周知のように延びている。カム１の運動
はロッカーアーム６を介して吸気バルブ５に伝達される
。FIG. 1 shows an embodiment of a valve train for an internal combustion engine according to the present invention. A known cam 1 is mounted on a camshaft 2. The cylinder head 3- is formed with an intake boat 4,
The intake valve 5 extends in a known manner. The movement of the cam 1 is transmitted to the intake valve 5 via the rocker arm 6.

ロッカーアーム６は支持部材となるクランクアーム７に
回転自在に取付けられる。即ち、クランクアーム７の一
端部に設けた枢着軸８に枢着される。クランクアーム７
は他端部において支持軸９に取付けられる。クランクア
ーム７の概略構成は第２図にも示されている。第２図に
おいては、支持軸９に一対となったクランクアーム７が
取付けられ、一対のクランクアーム７間に枢着軸８が配
置される。枢着軸８にロッカーアーム６が取付けられる
。カム軸２、枢着軸８及び支持軸９は相互に平行に配置
される。The rocker arm 6 is rotatably attached to a crank arm 7 that serves as a support member. That is, it is pivotally connected to a pivot shaft 8 provided at one end of the crank arm 7. crank arm 7
is attached to the support shaft 9 at the other end. A schematic configuration of the crank arm 7 is also shown in FIG. In FIG. 2, a pair of crank arms 7 are attached to a support shaft 9, and a pivot shaft 8 is arranged between the pair of crank arms 7. A rocker arm 6 is attached to a pivot shaft 8. The camshaft 2, the pivot shaft 8 and the support shaft 9 are arranged parallel to each other.

支持軸９はリンク１０を介して駆動装置１１に結合され
る。駆動装置１１は例えばアクセルに連（４） 結されたリンクとすることもでき、又は機関負荷に基い
て制御信号を発生するコンピュータと出力装置とからな
るものであってもよい。従って、支持軸９は機関負荷に
応じて所定量だけ回動することができる。The support shaft 9 is coupled to a drive device 11 via a link 10. The drive device 11 can, for example, be a link connected to an accelerator (4) or it can consist of a computer and an output device that generates a control signal based on the engine load. Therefore, the support shaft 9 can rotate by a predetermined amount depending on the engine load.

ロッカーアーム６のカム１に当接する面の輪郭及びバル
ブ５に当接する面の輪郭は、支持軸９の軸線を中心とす
る円の一部である円弧１２で形成されている。これによ
って、支持軸９の回動により枢着軸８の軸線の位置が第
１図の線１３上から第３図の線１４上に変化しても、こ
のとき同時にロッカーアーム６が枢着軸８の回りを回動
して、図に示すようなバルブリフト零の状態ではロッカ
ーアーム６の外面輪郭は常に一定の円弧１２上にあるこ
とになる。即ち、吸気バルブ５の全閉位置は常に一定に
保持されることができるようになる。The outline of the surface of the rocker arm 6 that contacts the cam 1 and the outline of the surface that contacts the valve 5 are formed by an arc 12 that is a part of a circle centered on the axis of the support shaft 9. As a result, even if the position of the axis of the pivot shaft 8 changes from on the line 13 in FIG. 1 to on the line 14 in FIG. 8, the outer contour of the rocker arm 6 always lies on a constant circular arc 12 when the valve lift is zero as shown in the figure. That is, the fully closed position of the intake valve 5 can always be maintained constant.

吸気バルブ５はスプリング１５によりロッカーアーム６
及び弁座（図示せず）側に付勢されている。The intake valve 5 is connected to the rocker arm 6 by the spring 15.
and the valve seat (not shown).

吸気バルブ（ステム）５の頭部はねじが設けられており
、このねじ部に螺合されたキャップ１６が（５） ロッカーアーム６の支承面を形成し、キャップ１６はロ
ックナツト１７により位置固定される。The head of the intake valve (stem) 5 is provided with a screw, and a cap 16 screwed onto this screw portion forms a support surface for the rocker arm 6 (5), and the cap 16 is fixed in position by a lock nut 17. Ru.

機関高負荷時には、支持軸９の回動により枢着軸８が第
１図の線１３上にあるようにされる。機関低負荷時には
第３図の線１４上にあるようにされ、これらの間の負荷
状態で段階的又は連続的な位置を占めることができる。When the engine is under high load, the rotation of the support shaft 9 causes the pivot shaft 8 to be located on the line 13 in FIG. At low engine loads, it lies on line 14 in FIG. 3, and can assume stepwise or continuous positions at load conditions between these.

前述したように、ロッカーアーム６がカム１の基本円弧
部に当接しているときには吸気バルブ５のリフトは零で
あり、従って吸気バルブ５は閉じられている。As described above, when the rocker arm 6 is in contact with the basic circular arc portion of the cam 1, the lift of the intake valve 5 is zero, and therefore the intake valve 5 is closed.

カムエが回転して、カム輪郭の突起部がロッカーアーム
６に当接するようになると、ロッカーアーム６は枢着軸
８を中心として図において時計回り方向に回動し、吸気
バルブ５を押して開弁させる。このときの開弁量、即ち
バルブリフトは同一のカム１であっても第１図や第３図
で示されるような枢着軸８の位置によって変化する。こ
れは枢着軸８の軸線からロッカーアーム６とカム１の接
触点までの距離に対する同軸線からロッカーアーム６と
カム１の接触点までの距離の比、即ちアー（６） ム比が変化することによるものであり、バルブリフトは
第１図に示す高負荷時の方が第３図に示す低負荷時より
も大きくなる。このような可変バルブリフト特性が第４
図に示されている。曲線Ａは高負荷時を示し、曲線Ｂは
低負荷時を示す。When the camouflage rotates and the protrusion of the cam contour comes into contact with the rocker arm 6, the rocker arm 6 rotates clockwise in the figure around the pivot shaft 8, pushing the intake valve 5 to open it. let The amount of valve opening at this time, that is, the valve lift, varies depending on the position of the pivot shaft 8 as shown in FIGS. 1 and 3 even if the cam 1 is the same. This changes the ratio of the distance from the coaxial line to the contact point of rocker arm 6 and cam 1 to the distance from the axis of pivot shaft 8 to the contact point of rocker arm 6 and cam 1, that is, the arm ratio changes. This is due to the fact that the valve lift is larger at the high load shown in FIG. 1 than at the low load shown in FIG. This type of variable valve lift characteristic is the fourth
As shown in the figure. Curve A shows the time of high load, and curve B shows the time of low load.

このような可変バルブリフトの利点は、低負荷時にバル
ブリフトを相対的に小さくできるために、吸気バルブを
通過する吸入空気（又は空燃混合物）の速度が増し、燃
焼室内に強い乱れを発生させ、よって燃焼が改善される
ことにある。高負荷時にはバルブリフトが大きくなるた
め絞られることなく多量の空気（混合物）が吸入され、
出力の向上が図られる。The advantage of such a variable valve lift is that the valve lift can be relatively small at low loads, which increases the velocity of the intake air (or air/fuel mixture) passing through the intake valve, creating strong turbulence in the combustion chamber. , thus improving combustion. At high loads, the valve lift increases, so a large amount of air (mixture) is sucked in without being throttled.
The output is improved.

効果 以上の説明から明らかなように、本発明によれば、簡単
な構造で可変バルブリフトを実現することができ、カム
、ロッカーアーム及びバルブはそれぞれ円滑に接触して
いるために確実で正確なバルブ作動が得られる。Effects As is clear from the above explanation, according to the present invention, variable valve lift can be realized with a simple structure, and since the cam, rocker arm, and valve are in smooth contact with each other, reliable and accurate valve lift can be achieved. Valve actuation is obtained.

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

（７） 第１図は本発明による内燃機関の動弁機構を示す断面図
、第２図はロッカーアーム支持部材を簡単に示した斜視
図、第３図は他の状態にある第１図の動弁機構の断面図
、第４図はバルブリフト特性を示すグラフである。 １・・・カム、５・・・吸気バルブ、６・・・ロッカー
アーム、７・・・クランクアーム、８・・・枢着軸、９
・・・支持軸、１１・・・駆動装置。 特許出願人 トヨタ自動車株式会社 特許出願代理人 弁理士　青　木　　　朗 弁理士西舘和之 弁理土中山恭介 弁理士　山　口　昭　之 （８）(7) Fig. 1 is a cross-sectional view showing the valve mechanism of an internal combustion engine according to the present invention, Fig. 2 is a perspective view simply showing the rocker arm support member, and Fig. 3 is the same structure as Fig. 1 in another state. FIG. 4, which is a cross-sectional view of the valve mechanism, is a graph showing valve lift characteristics. 1...Cam, 5...Intake valve, 6...Rocker arm, 7...Crank arm, 8...Pivot shaft, 9
...Support shaft, 11...Drive device. Patent Applicant: Toyota Motor Corporation Patent Application Agent: Akira Aoki, Patent Attorney: Kazuyuki Nishidate, Patent Attorney: Kyosuke Tsuchinakayama, Patent Attorney: Akira Yamaguchi (8)

Claims (1)

【特許請求の範囲】[Claims] カムとバルブとの間で運動を伝達するロッカーアームが
カム軸と平行な回転軸線を有する支持部材に枢着され、
該支持部材はカム軸と平行に延びる支持軸に取付けられ
、上記ロッカーアームのカムに当接する面の輪郭及びバ
ルブに当接する面の輪郭が上記支持軸の軸線を中心とす
る円の円弧により形成され、さらに上記支持軸を機関負
荷に応じて所定角度だけ回動せしめる駆動装置が設けら
れ、上記支持軸の回動によりバルブリフトが変化するよ
うにした内燃機関の動弁機構。A rocker arm that transmits motion between the cam and the valve is pivotally connected to a support member having a rotation axis parallel to the camshaft;
The support member is attached to a support shaft extending parallel to the camshaft, and the outline of the surface of the rocker arm that contacts the cam and the outline of the surface that contacts the valve are formed by an arc of a circle centered on the axis of the support shaft. The valve operating mechanism for an internal combustion engine is further provided with a drive device that rotates the support shaft by a predetermined angle in accordance with engine load, and the valve lift is changed by rotation of the support shaft.
JP10429983A 1983-06-13 1983-06-13 Valve mechanism of internal-combustion engine Pending JPS59231115A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10429983A JPS59231115A (en) 1983-06-13 1983-06-13 Valve mechanism of internal-combustion engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10429983A JPS59231115A (en) 1983-06-13 1983-06-13 Valve mechanism of internal-combustion engine

Publications (1)

Publication Number Publication Date
JPS59231115A true JPS59231115A (en) 1984-12-25

Family

ID=14377042

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10429983A Pending JPS59231115A (en) 1983-06-13 1983-06-13 Valve mechanism of internal-combustion engine

Country Status (1)

Country Link
JP (1) JPS59231115A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5074260A (en) * 1989-04-27 1991-12-24 Honda Giken Kogyo Kabushiki Kaisha Valve driving device and valve driving method for internal combustion engine
US5253620A (en) * 1992-03-20 1993-10-19 Mercedes-Benz Ag Internal combustion engine adjustable valve gear
US7363899B2 (en) 2006-02-22 2008-04-29 Schaeffler Kg Valve drive of an internal combustion engine

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5074260A (en) * 1989-04-27 1991-12-24 Honda Giken Kogyo Kabushiki Kaisha Valve driving device and valve driving method for internal combustion engine
US5253620A (en) * 1992-03-20 1993-10-19 Mercedes-Benz Ag Internal combustion engine adjustable valve gear
US7363899B2 (en) 2006-02-22 2008-04-29 Schaeffler Kg Valve drive of an internal combustion engine

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