JP2020193588A - Valve lift adjustment device of internal combustion engine - Google Patents
Valve lift adjustment device of internal combustion engine Download PDFInfo
- Publication number
- JP2020193588A JP2020193588A JP2019099351A JP2019099351A JP2020193588A JP 2020193588 A JP2020193588 A JP 2020193588A JP 2019099351 A JP2019099351 A JP 2019099351A JP 2019099351 A JP2019099351 A JP 2019099351A JP 2020193588 A JP2020193588 A JP 2020193588A
- Authority
- JP
- Japan
- Prior art keywords
- cam
- internal combustion
- combustion engine
- valve lift
- valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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
- F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
-
- 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
- F01L1/30—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of positively opened and closed valves, i.e. desmodromic valves
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
Description
本発明は、内燃機関に用いられるバルブの作動を連続的に制御するためのバルブリフト調整装置に関する。 The present invention relates to a valve lift adjusting device for continuously controlling the operation of a valve used in an internal combustion engine.
自動車や自動二輪車などに搭載される内燃機関では、様々な回転数や負荷状態での出力が要求され、このような内燃機関の出力の制御のため、シリンダーヘッドに配設される吸排気バルブを可変な所定のリフト量や弁角度で作動させることが行われている。このような可変バルブ機構については、種々の構造のものが知られているが、その一例としては複数のカムを切り替える方式ものが知られており、主に高回転時に使用されるカムと低回転時に使用されるカムをカムシャフトの軸方向に並べ、これらの間でカムシャフトの軸方向にカムをスライドさせて弁に作動するカムを切り替えることができる（例えば、特許文献１参照。）。 Internal combustion engines installed in automobiles and motorcycles are required to output at various rotation speeds and load conditions, and in order to control the output of such internal combustion engines, intake and exhaust valves arranged in the cylinder head are used. It is operated with a variable predetermined lift amount and valve angle. As for such a variable valve mechanism, various structures are known, and as an example, a method of switching a plurality of cams is known, and a cam mainly used at high rotation speed and a low rotation speed are known. The cams sometimes used can be arranged in the axial direction of the camshaft, and the cams can be slid in the axial direction of the camshaft to switch the cams that operate on the valve (see, for example, Patent Document 1).
ところが、上記文献記載の技術では、高速回転域と低速回転域で２段階の切り替えが可能とされるが、さらに多くの制御には対応できないという欠点があり、カムシャフト上のカムキャリアにカムを配設する場合には、２つのカム間の距離も精度良く組み立てる必要がある。このような複数のカムを使用する場合には、それぞれのカムの部品精度も必要とされるが、同時に部品点数の増大や、複数のカムの間のスペースの寸法精度も必要となり、それを確保するためには、連動する部品によるシリンダーヘッド回りの空間の占有も問題となって、内燃機関の軽量化や小型化などの要求に対する障害となり得る。 However, in the technique described in the above document, it is possible to switch between two stages in the high-speed rotation range and the low-speed rotation range, but there is a drawback that it cannot support more control, and the cam is attached to the cam carrier on the camshaft. When arranging, it is necessary to assemble the distance between the two cams with high accuracy. When using multiple cams like this, the accuracy of the parts of each cam is also required, but at the same time, it is also necessary to increase the number of parts and the dimensional accuracy of the space between the multiple cams, which is ensured. In order to do so, the occupation of the space around the cylinder head by the interlocking parts also becomes a problem, which may be an obstacle to the demands such as weight reduction and miniaturization of the internal combustion engine.
本発明は、上述の技術的は課題に鑑み、柔軟なバルブリフト制御が可能とされ複数カムに起因する占有空間などの問題も解決できる内燃機関のバルブリフト調整装置を提供することを目的とする。 An object of the present invention is to provide a valve lift adjusting device for an internal combustion engine, which enables flexible valve lift control and can solve problems such as occupied space caused by a plurality of cams in view of the above-mentioned technical problems. ..
上述の技術的は課題を解決するため、本発明の内燃機関のバルブリフト調整装置は、内燃機関のシリンダーヘッドに回転自在に軸支されたカムシャフトと、該カムシャフトの外周に配設され、前記シリンダーヘッドに設けられた吸排気バルブに作動させるように設けられたカムを有し、前記カムは前記カムシャフトの軸方向に前記シリンダーヘッドに対して相対的に摺動可能とされ、前記カムの前記カムシャフトの軸方向への移動に伴って無段階で連続して変化するカム外周面の形状に従い前記吸排気バルブの開閉が制御されることを特徴とする。 In order to solve the above-mentioned technical problems, the valve lift adjusting device for an internal combustion engine of the present invention is provided with a camshaft rotatably supported by the cylinder head of the internal combustion engine and an outer periphery of the camshaft. It has a cam provided to operate on an intake / exhaust valve provided on the cylinder head, and the cam is made slidable relative to the cylinder head in the axial direction of the camshaft. It is characterized in that the opening and closing of the intake / exhaust valve is controlled according to the shape of the outer peripheral surface of the cam that continuously changes steplessly with the axial movement of the camshaft.
前記バルブリフト調整装置によれば、前記カムのカム外周面は、前記カムシャフトの軸方向の一端側から他端側に向けて連続した斜面を有するように構成することができる。カム外周面には、バルブの開閉動作と連動するロッカーアームが当接することから、カム外周面の一端側から他端側に向けて連続した斜面にロッカーアームを当接させることで、バルブのリフト量や開閉時期を連続的に変えることができ、より多くの状況に対応した制御が実現される。 According to the valve lift adjusting device, the cam outer peripheral surface of the cam can be configured to have a continuous slope from one end side to the other end side in the axial direction of the cam shaft. Since the rocker arm that works with the opening and closing operation of the valve comes into contact with the outer peripheral surface of the cam, the rocker arm is brought into contact with the continuous slope from one end side to the other end side of the outer peripheral surface of the cam to lift the valve. The amount and opening / closing timing can be changed continuously, and control corresponding to more situations is realized.
以下、本発明の内燃機関のバルブリフト調整装置の第１の実施形態について図１ないし図４を参照しながら説明する。本実施形態の内燃機関は、例示として自動二輪車に搭載される２バルブ方式の単気筒の内燃機関である。 Hereinafter, the first embodiment of the valve lift adjusting device for an internal combustion engine of the present invention will be described with reference to FIGS. 1 to 4. The internal combustion engine of the present embodiment is, for example, a two-valve single-cylinder internal combustion engine mounted on a motorcycle.
図１は本実施形態の吸気側のカム及びカムシャフトの断面図であり、円柱状の部材のカムシャフト１０の外周に円柱状のカムキャリア１２が設けられ、このカムキャリア１２のさらに外周面にカム１４が設けられている。カム１４は無段階で連続して傾斜したカム外周面を有する楕円錐台形状を有しており、カムシャフト１０の一端側では長径が長いカムの楕円形状断面を有し、逆にカムシャフト１０の他端側では長径が短いカムの楕円形状断面を有し、それらが外周面１６上は面内に段差を生じないように連続する面を有する。すなわち、カムの、カムシャフトの軸方向に垂直な断面における長径サイズは、カムシャフト１０の一端側から他端側に向かって徐々に短くなるように設計されており、カム１４を短径の延長線上から見た場合には、図２に示すように、カム１４の縁が斜めに傾斜した形状を呈する。 FIG. 1 is a cross-sectional view of a cam and a camshaft on the intake side of the present embodiment. A columnar cam carrier 12 is provided on the outer periphery of a camshaft 10 of a columnar member, and a cylindrical cam carrier 12 is further provided on the outer peripheral surface of the cam carrier 12. A cam 14 is provided. The cam 14 has an elliptical cone shape having a cam outer peripheral surface that is continuously inclined steplessly, and one end side of the cam shaft 10 has an elliptical cross section of a cam having a long major axis, and conversely, the cam shaft 10 The other end side of the cam has an elliptical cross section with a short major axis, and they have a continuous surface on the outer peripheral surface 16 so as not to cause a step in the surface. That is, the major axis size of the cam in the cross section perpendicular to the axial direction of the cam shaft is designed to be gradually shortened from one end side to the other end side of the cam shaft 10, and the cam 14 is an extension of the minor axis. When viewed from the line, as shown in FIG. 2, the edge of the cam 14 has an obliquely inclined shape.
このように連続して傾斜する外周面１６を有するカム１４は、内燃機関のシリンダーヘッド内で、その外周面１６に従動節としてのロッカーアーム２２が当接される。ロッカーアーム２２は、スイングアーム式であってカムシャフト１０とその軸方向が平行に延長されるロッカーシャフト２６に回動自在に軸支されている。ロッカーアーム２２とカム１４の外周面１６との摺接点には回転自在なローラ２４がロッカーアーム２２の上面に設けられ、回転するカム１４の外周面１６にローラ２４の周面が当接する。なお、カム１４は軸方向に対して傾斜して連続する外周面１６を有しているが、摩擦を減らすことができるローラ２４が当接することから、カム１４とロッカーアーム２２の間では比較的に摩擦の小さな当接関係が実現され、耐摩耗性も向上する The cam 14 having the outer peripheral surface 16 that is continuously inclined in this way is brought into contact with the rocker arm 22 as a driven node of the outer peripheral surface 16 in the cylinder head of the internal combustion engine. The rocker arm 22 is a swing arm type and is rotatably supported by a rocker shaft 26 whose axial direction is extended in parallel with the cam shaft 10. A rotatable roller 24 is provided on the upper surface of the rocker arm 22 at the sliding contact point between the rocker arm 22 and the outer peripheral surface 16 of the cam 14, and the peripheral surface of the roller 24 comes into contact with the outer peripheral surface 16 of the rotating cam 14. Although the cam 14 has a continuous outer peripheral surface 16 that is inclined in the axial direction, the roller 24 that can reduce friction comes into contact with the cam 14, so that the cam 14 and the rocker arm 22 are relatively close to each other. A contact relationship with low friction is realized, and wear resistance is also improved.
ロッカーアーム２２のロッカーシャフト２６から離れたアーム先端側の底部では、吸気側のバルブ２８のシャフト３０の上端部に当接する。ロッカーアーム２２は、ロッカーアーム２２の作用部となる端部の上下動に応じて吸気側のバルブ２８のリフト量やバルブ２８の開閉のタイミングを制御する。吸気側のバルブ２８は、図示しないコイルバネなどにより常時軸方向上側に付勢されており、バルブ２８の位置が最も上側の時、バルブ２８は閉状態とされ、ロッカーアーム２２の揺動に応じてバルブ２８は開閉する。カム１４の長径部分のカム面がロッカーアーム２２に当接するタイミングで最もバルブ２８のリフト量が大きくなるように制御される。 The bottom of the rocker arm 22 on the tip end side of the arm away from the rocker shaft 26 abuts on the upper end of the shaft 30 of the valve 28 on the intake side. The rocker arm 22 controls the lift amount of the valve 28 on the intake side and the opening / closing timing of the valve 28 according to the vertical movement of the end portion of the rocker arm 22. The valve 28 on the intake side is always urged upward in the axial direction by a coil spring or the like (not shown), and when the position of the valve 28 is the uppermost, the valve 28 is closed and responds to the swing of the rocker arm 22. The valve 28 opens and closes. The lift amount of the valve 28 is controlled to be the largest at the timing when the cam surface of the major axis portion of the cam 14 comes into contact with the rocker arm 22.
カムシャフト１０の他端部には、図示しないタイミングチェーンなどにより駆動される吸気側従動ギア１８が設けられており、内燃機関のクランクシャフトに連動してカムシャフト１０は回転される。また、カムのプロフィールを変更するためには、カムシャフト１０上のカム１４の位置を軸方向に摺動させることが行われるが、モーターなどで駆動する電動アクチュエーターや油圧回路等が作動するとカムシャフト１０の外周部に設けられたカムキャリア１２が摺動し、このカムキャリア１２の軸方向への移動に伴い、カム１４の位置もカムシャフト１０に沿って移動する。ここでカム１４の移動には、所定のモーターや油圧回路が使用され、回転速度に応じた最適な位置及びタイミングにカム１４を摺動させる。 At the other end of the camshaft 10, an intake side driven gear 18 driven by a timing chain or the like (not shown) is provided, and the camshaft 10 is rotated in conjunction with the crankshaft of the internal combustion engine. Further, in order to change the profile of the cam, the position of the cam 14 on the camshaft 10 is slid in the axial direction, but when an electric actuator driven by a motor or the like, a hydraulic circuit or the like is activated, the camshaft is operated. The cam carrier 12 provided on the outer peripheral portion of the 10 slides, and the position of the cam 14 also moves along the cam shaft 10 as the cam carrier 12 moves in the axial direction. Here, a predetermined motor or hydraulic circuit is used to move the cam 14, and the cam 14 is slid at an optimum position and timing according to the rotation speed.
カム１４は、上述のように、カムシャフト１０上のカム１４の水平方向の位置に応じて、カムの回転中心からカム１４の外周部１６とロッカーアーム２２の当接部であるローラ２４までの距離が変化し、高速回転時にはバルブ２８のリフト量が多くなり、逆に低速回転時にはバルブ２８のリフト量は少なくなるように制御される。図３は、本実施形態の内燃機関のバルブリフト調整装置にかかるカム１４の断面であり、Ａ断面はカムシャフト１０の一端側に最も近い側の図２におけるＡ−Ａ線断面、Ｂ断面はカムシャフト１０の一端側と他端側のほぼ中間部分の図２おけるＢ−Ｂ線断面、Ｃ断面はカムシャフト１０の他端側に最も近い側の図２におけるＣ−Ｃ線断面である。 As described above, the cam 14 extends from the center of rotation of the cam to the roller 24 which is the contact portion between the outer peripheral portion 16 of the cam 14 and the rocker arm 22 according to the horizontal position of the cam 14 on the cam shaft 10. The distance is changed, and the lift amount of the valve 28 is increased at high speed rotation, and conversely, the lift amount of the valve 28 is controlled to be small at low speed rotation. FIG. 3 is a cross section of the cam 14 of the valve lift adjusting device of the internal combustion engine of the present embodiment. The A cross section is the AA line cross section and the B cross section in FIG. 2 on the side closest to one end side of the camshaft 10. The BB line cross section in FIG. 2 and the C cross section of the substantially intermediate portion between one end side and the other end side of the camshaft 10 are the CC line cross sections in FIG. 2 on the side closest to the other end side of the camshaft 10.
カムのＡ断面は、３つの断面の中で最も断面積が大きくなり、カムの長径も長くなり、カムの回転中心からロッカーアームの当接部までの距離ＬＡも長くなることから、バルブのリフト量が大きくなって、その部分ではピストンの行程容積に対する大気状態に換算した吸入新気の容積比である充填率を高くすることができる。また、カムのＣ断面は、３つの断面の中で最も断面積が小さくなり、カムの長径ＬＣも短くなり、カムの回転中心からロッカーアームの当接部までの距離も短くなることから、バルブのリフト量が小さくなって、その部分では排気の残りや逆流ガスなどの残留ガスを低くできる。Ｂ断面は、Ａ断面とＣ断面の中間的は断面形状を示し、３つの断面の中では中間的な断面積とされ、カムの長径ＬＢも中間的な値をとり、従って、バルブのリフト量も中間値となる。高速回転時にはバルブ２８のリフト量が多くなり、逆に低速回転時にはバルブ２８のリフト量は少なくなるように制御されることから、高速回転時にはＡ断面となるような位置でカム１４、１６の位置が設定され、反対に低速回転時にはＣ断面となるような位置でカム１４、１６の位置が設定される。そして、本実施形態の内燃機関のバルブリフト調整装置では、Ａ断面とＣ断面の間の中間的なＢ断面によっても、バルブ２８のリフト量を制御することができ、中間的なＢ断面を使用することで例えば高速と低速の間の中速度に対応した効率の良い制御が可能となる。 A cross section of the cam is most cross-sectional area is increased in the three section, even longer major axis of the cam, since it also increases the distance L A to the contact portion of the rocker arm from the rotation center of the cam, the valve As the lift amount increases, the filling rate, which is the volume ratio of the intake fresh air converted into the atmospheric state with respect to the stroke volume of the piston, can be increased in that portion. Also, C cross-section of the cam, most cross-sectional area is reduced in the three section, major axis L C of the cam is shortened, since the even shorter distance from the rotation center of the cam to the abutting portion of the rocker arm, The lift amount of the valve is reduced, and the residual gas such as the residual exhaust gas and the backflow gas can be reduced in that portion. B cross-section, intermediate the A section and C cross section shows a cross-sectional shape, is an intermediate cross-sectional area of the three section, also take intermediate values major axis L B of the cam, thus, the lift of the valve The amount is also an intermediate value. Since the lift amount of the valve 28 is controlled to increase during high-speed rotation and conversely, the lift amount of the valve 28 is controlled to decrease during low-speed rotation, the positions of cams 14 and 16 are positioned so as to have an A cross section during high-speed rotation. Is set, and conversely, the positions of the cams 14 and 16 are set at positions that form a C cross section during low-speed rotation. Then, in the valve lift adjusting device of the internal combustion engine of the present embodiment, the lift amount of the valve 28 can be controlled by the intermediate B cross section between the A cross section and the C cross section, and the intermediate B cross section is used. By doing so, for example, efficient control corresponding to a medium speed between high speed and low speed becomes possible.
さらに、３つの断面の面の広がりを比べてみると、カムのＡ断面は、カムの長径部分からの立下りが緩やかであり、即ち、回転角が進んだ場合でもバルブのリフト量が最大値から低下する速度も遅く、ゆっくりとバルブ２８が閉じられ且つ開かれるものであることが分かる。また、カムのＣ断面は、カムの長径部分からの立下りがやや急峻になり、即ち、回転角が進んだ場合でもバルブのリフト量が最大値から低下する速度が速く、素早くバルブ２８が閉じられ且つ開かれるものであることが分かる。カムのＢ断面は、３つの断面の中では中間的な断面積とされ、Ａ断面の場合よりも素早くバルブ２８は開閉するが、Ｃ］断面よりはゆっくりとバルブ２８は開閉する。このようにカム１４の外形形状をバルブ２８の開閉速度に合わせて構成することができる。 Furthermore, when comparing the spreads of the surfaces of the three cross sections, the A cross section of the cam has a gentle fall from the major axis portion of the cam, that is, the lift amount of the valve is the maximum value even when the rotation angle advances. It can be seen that the rate of decrease is also slow, and the valve 28 is slowly closed and opened. Further, in the C cross section of the cam, the falling edge from the major axis portion of the cam becomes slightly steep, that is, even if the rotation angle advances, the valve lift amount decreases from the maximum value at a high speed, and the valve 28 closes quickly. It turns out that it is open and open. The B cross section of the cam has an intermediate cross-sectional area among the three cross sections, and the valve 28 opens and closes faster than in the case of the A cross section, but opens and closes more slowly than in the C] cross section. In this way, the outer shape of the cam 14 can be configured according to the opening / closing speed of the valve 28.
本実施形態の内燃機関のバルブリフト調整装置では、各カムが無段階で連続して変化するカム外周面の形状を有することから、先に説明したＡ乃至Ｃ断面の３段階だけではなく、さらにその間の連続的に変化するバルブリフト調整を実現する。図４は、カムシャフトの回転角度に対するバルブのリフト量を模式的に示したグラフであり、縦軸はバルブのリフト量であり、横軸はカムシャフトの回転角度である。このグラフによってカムシャフトの回転に応じて、カム１４におけるバルブリフト量も変動することが分かるが、本実施形態のバルブリフト調整装置では、無段階のバルブリフト量の調整が可能であり、特に中間速度での制御に幅を持たせることができる。図４に示すように、曲線Ａは図３のカム断面Ａに対応したプロフィールであり、曲線Ｂは図３のカム断面Ｂに対応したプロフィールであり、曲線Ｃは図３のカム断面Ｃに対応したプロフィールである。さらに曲線Ａと曲線Ｂの間には曲線Ｍ１が存在し、曲線Ｂと曲線Ｃの間には曲線Ｍ２が存在する。これらの曲線Ｍ１、Ｍ２はカム１４におけるバルブリフト量も中間的は値を取り得ることを示しており、本実施形態のバルブリフト調整装置は無段階のバルブリフト量の調整が可能なことから、これらの曲線Ｍ１、Ｍ２自体をそれぞれ曲線Ａ若しくは曲線Ｂ、曲線Ｂ若しくは曲線Ｃに寄せた位置に移動させることもできる。 In the valve lift adjusting device of the internal combustion engine of the present embodiment, since each cam has a shape of the outer peripheral surface of the cam that changes continuously in a stepless manner, not only the three stages of the cross sections A to C described above but also further. Achieve continuously changing valve lift adjustment during that time. FIG. 4 is a graph schematically showing the lift amount of the valve with respect to the rotation angle of the camshaft, the vertical axis is the lift amount of the valve, and the horizontal axis is the rotation angle of the camshaft. From this graph, it can be seen that the valve lift amount in the cam 14 also fluctuates according to the rotation of the camshaft. However, in the valve lift adjusting device of the present embodiment, the valve lift amount can be adjusted steplessly, particularly in the middle. There can be a range of control over speed. As shown in FIG. 4, the curve A corresponds to the cam cross section A in FIG. 3, the curve B corresponds to the cam cross section B in FIG. 3, and the curve C corresponds to the cam cross section C in FIG. Profile. Further, there is a curve M1 between the curve A and the curve B, and a curve M2 between the curve B and the curve C. These curves M1 and M2 indicate that the valve lift amount in the cam 14 can also take an intermediate value, and the valve lift adjusting device of the present embodiment can adjust the valve lift amount steplessly. It is also possible to move these curves M1 and M2 themselves to positions closer to the curve A or B, the curve B or the curve C, respectively.
図５はカムの形状の変形例の断面図を示しており、先の実施形態の例と同様に、カム４０は軸方向に対して段々と傾斜して連続するカム外周面を有している。さらにカム４０は、図５に示すように、長径自体が回転方向で遅れた位置にあるＤ断面と、長径自体が回転方向で進んだ位置にあるＦ断面と、遅れも進みもない位置にあるＥ断面とを呈する形状とされ、カムのシャフト方向からは捩じれた形状の外周面を有している。 FIG. 5 shows a cross-sectional view of a modified example of the shape of the cam. Similar to the example of the previous embodiment, the cam 40 has a continuous cam outer peripheral surface that is gradually inclined with respect to the axial direction. .. Further, as shown in FIG. 5, the cam 40 is in a position where there is no delay or advance, with a D cross section in which the major axis itself is delayed in the rotational direction and an F cross section in which the major axis itself is advanced in the rotational direction. It has a shape that exhibits an E cross section, and has an outer peripheral surface that is twisted from the shaft direction of the cam.
即ち、この変形例のカム４０では、一端側に最も近い側のＤ断面は、長径方向が垂直な断面Ｂに対して角度ＡＤだけ傾いた長径方向を有し、他端側に最も近い側のＦ断面は、長径方向が垂直な断面Ｂに対して角度ＡＦだけ傾いた長径方向を有しており、同じカム４０の内部でカムシャフトに垂直な断面での長径方向が徐々に変化する。 That is, in the cam 40 of this modification, the cross section D on the side closest to one end side has a major axis direction inclined by an angle AD with respect to the cross section B whose major axis direction is perpendicular, and the side closest to the other end side. The F cross section of is inclined by an angle AF with respect to the cross section B perpendicular to the major axis direction, and the major axis direction in the cross section perpendicular to the cam shaft gradually changes inside the same cam 40. ..
図７はさらに他の実施形態のカム及びカムシャフトの構造一部断面図であり、本実施形態は吸排気弁をバルブスプリングに依らず、カムとロッカーアームの機構によって閉じる機構であるデスモドロミック機構を備えている。円柱状の部材のカムシャフト４０の外周に円柱状のカムキャリア４２が設けられ、このカムキャリア４２のさらに外周面に第１のカム４４と第２のカム４６が設けられている。第１のカム４４はバルブ６６の位置を押し下げる際に大きく作用するカムであり、その連続して傾斜した外周面４８は回転自在なローラ５４に当接しながら該ローラ５４を備えたロッカーアーム５２を介してリング部材５６を押し下げることができ、これによりシャフト６４を介してバルブ６６は押し下げられる。第２のカム４６はバルブ６６の位置を押し上げる際に大きく作用するカムであり、その連続して傾斜した外周面５０は回転自在なローラ６２に当接しながら該ローラ６２を備えたロッカーアーム６０とアーム連続部５８を介してリング部材５６を押し上げることができ、これによりシャフト６４を介してバルブ６６は押し上げられる。 FIG. 7 is a partial cross-sectional view of the structure of the cam and camshaft of still another embodiment. In this embodiment, the intake / exhaust valve is closed by a cam and rocker arm mechanism without depending on a valve spring. It has a mechanism. A columnar cam carrier 42 is provided on the outer periphery of the camshaft 40 of the columnar member, and a first cam 44 and a second cam 46 are provided on the outer peripheral surface of the cam carrier 42. The first cam 44 is a cam that greatly acts when pushing down the position of the valve 66, and its continuously inclined outer peripheral surface 48 abuts on the rotatable roller 54 while holding the rocker arm 52 provided with the roller 54. The ring member 56 can be pushed down through the shaft 64, which pushes down the valve 66. The second cam 46 is a cam that greatly acts when pushing up the position of the valve 66, and its continuously inclined outer peripheral surface 50 is in contact with the rotatable roller 62 with the rocker arm 60 provided with the roller 62. The ring member 56 can be pushed up via the arm continuous portion 58, whereby the valve 66 is pushed up via the shaft 64.
第１のカム４４と第２のカム４６は、それぞれバルブ６６の開閉のタイミングに応じて所要の角度差を以ってカムキャリア４２に取り付けられているが、図１に示した実施形態と同様に、第１のカム４４と第２のカム４６は、そのシャフト４０の軸方向で位置を変えるように移動することができる。即ち、従動ギア５２側に第１のカム４４と第２のカム４６が移動した場合には、それぞれ径のより大きなカムに当接するのと同じ効果が得られ、その従動ギア５２から離れる方向に第１のカム４４と第２のカム４６が移動した場合には、それぞれ径のより小さなカムに当接するのと同じ効果が得られる。各カム４４、４６の外周面４８、５０の形状は、バルブのタイミングとその変化（リフト量及びリフト角）に応じて設定することができ、このようにデスモドロミック機構に対しても本実施形態の内燃機関のバルブリフト調整装置は、リフト量とタイミングとリフト角が無段階に変化させることができる。なお、本実施形態では、第１、第２のカムが同軸に配列される例を説明したが、第１、第２のカムが異なる軸で配列される装置であっても良い。 The first cam 44 and the second cam 46 are attached to the cam carrier 42 with a required angle difference according to the opening / closing timing of the valve 66, respectively, as in the embodiment shown in FIG. In addition, the first cam 44 and the second cam 46 can be moved so as to change their positions in the axial direction of the shaft 40. That is, when the first cam 44 and the second cam 46 move to the driven gear 52 side, the same effect as contacting the cam having a larger diameter is obtained, and the direction away from the driven gear 52 is obtained. When the first cam 44 and the second cam 46 move, the same effect as contacting a cam having a smaller diameter can be obtained. The shapes of the outer peripheral surfaces 48 and 50 of the cams 44 and 46 can be set according to the valve timing and its change (lift amount and lift angle), and thus this implementation is also applied to the desmodromic mechanism. The valve lift adjusting device of the internal combustion engine of the form can change the lift amount, timing and lift angle steplessly. In the present embodiment, the example in which the first and second cams are arranged coaxially has been described, but the device may be a device in which the first and second cams are arranged on different axes.
１０、４０ カムシャフト
１２、４２ カムキャリア
１４、１６、４０、４４、４６ カム
１８、５２ 従動ギア
２２、２４、４４、５２、６０ ロッカーアーム
２８、６０ バルブ
10, 40 Camshaft 12, 42 Cam carrier 14, 16, 40, 44, 46 Cam 18, 52 Driven gear 22, 24, 44, 52, 60 Rocker arm 28, 60 Valve
Claims (4)
前記カムは前記カムシャフトの軸方向に前記シリンダーヘッドに対して相対的に摺動可能とされ、前記カムの前記カムシャフトの軸方向への移動に伴って無段階で連続して変化するカム外周面の形状に従い前記吸排気バルブの開閉が制御されることを特徴とする内燃機関のバルブリフト調整装置。 It has a camshaft that is rotatably supported by the cylinder head of an internal combustion engine, and a cam that is arranged on the outer periphery of the camshaft and is provided to operate on an intake / exhaust valve provided on the cylinder head.
The cam is slidable relative to the cylinder head in the axial direction of the cam shaft, and the outer circumference of the cam changes steplessly and continuously as the cam shaft moves in the axial direction. A valve lift adjusting device for an internal combustion engine, characterized in that the opening and closing of the intake / exhaust valve is controlled according to the shape of the surface.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019099351A JP2020193588A (en) | 2019-05-28 | 2019-05-28 | Valve lift adjustment device of internal combustion engine |
| PCT/JP2020/020855 WO2020241667A1 (en) | 2019-05-28 | 2020-05-27 | Internal combustion engine valve lift adjusting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019099351A JP2020193588A (en) | 2019-05-28 | 2019-05-28 | Valve lift adjustment device of internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2020193588A true JP2020193588A (en) | 2020-12-03 |
Family
ID=73546243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2019099351A Pending JP2020193588A (en) | 2019-05-28 | 2019-05-28 | Valve lift adjustment device of internal combustion engine |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2020193588A (en) |
| WO (1) | WO2020241667A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03156112A (en) * | 1989-11-13 | 1991-07-04 | Nissan Motor Co Ltd | Variable valve system for engine |
| US5445117A (en) * | 1994-01-31 | 1995-08-29 | Mendler; Charles | Adjustable valve system for a multi-valve internal combustion engine |
| JPH0921305A (en) * | 1995-07-04 | 1997-01-21 | Otix:Kk | Variable valve gear |
-
2019
- 2019-05-28 JP JP2019099351A patent/JP2020193588A/en active Pending
-
2020
- 2020-05-27 WO PCT/JP2020/020855 patent/WO2020241667A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03156112A (en) * | 1989-11-13 | 1991-07-04 | Nissan Motor Co Ltd | Variable valve system for engine |
| US5445117A (en) * | 1994-01-31 | 1995-08-29 | Mendler; Charles | Adjustable valve system for a multi-valve internal combustion engine |
| JPH0921305A (en) * | 1995-07-04 | 1997-01-21 | Otix:Kk | Variable valve gear |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2020241667A1 (en) | 2020-12-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5365895A (en) | Variable valve lift mechanism for internal combustion engine | |
| US5074260A (en) | Valve driving device and valve driving method for internal combustion engine | |
| US7913658B2 (en) | Valve actuating mechanism for an internal combustion engine, and cylinder head incorporating same | |
| US5107802A (en) | Valve driving mechanism for internal combustion engines | |
| US20030121484A1 (en) | Continuously variable valve timing, lift and duration for internal combustion engine | |
| JP2007146733A (en) | Variable valve gear for internal combustion engine | |
| US20030127063A1 (en) | Continually variable valve timing, lift, and duration for internal combustion engine | |
| EP2561191B1 (en) | Valve lift device for a combustion engine | |
| KR102440614B1 (en) | Continuous varible vavle duration apparatus and engine provided with the same | |
| WO2020241667A1 (en) | Internal combustion engine valve lift adjusting device | |
| JP2005140026A (en) | Engine valve system | |
| KR101317140B1 (en) | Continuous variable valve lift apparatus | |
| KR100897263B1 (en) | Continuous variable valve lift apparatus | |
| EP0354926B1 (en) | Variable timing system for engine valve operating gear | |
| KR100957145B1 (en) | Continuous variable valve lift apparatus | |
| JP4871310B2 (en) | Variable valve mechanism for internal combustion engine | |
| KR101241595B1 (en) | Variable valve timing device of car engine | |
| JP2007146734A (en) | Variable valve gear for internal combustion engine | |
| KR100521171B1 (en) | variable valve actuation apparatus for engine | |
| JPH0245603A (en) | Variable valve timing device for intake/exhaust system of engine | |
| KR20120124650A (en) | Dual valve timing apparatus using decenterizing axis and self locking | |
| JP5556932B2 (en) | Valve system for internal combustion engine | |
| JP2007154706A (en) | Variable valve gear | |
| LV13993B (en) | Device for gas allocation adjustement in internal combustion engines | |
| JP2010270706A (en) | Variable valve gear for internal combustion engine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20200526 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200811 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20210302 |