JP2009185656A

JP2009185656A - Valve gear for engine

Info

Publication number: JP2009185656A
Application number: JP2008025136A
Authority: JP
Inventors: Daijiro Masuda; 大治郎益田
Original assignee: Suzuki Motor Corp
Current assignee: Suzuki Motor Corp
Priority date: 2008-02-05
Filing date: 2008-02-05
Publication date: 2009-08-20

Abstract

PROBLEM TO BE SOLVED: To stabilize operation characteristics in valve timing change with maintaining good response, and avoid enlargement of a device and increase of manufacturing cost. SOLUTION: A camshaft phase variable device 40 of a valve gear 20 includes a drive member 42 driven by a crankshaft and has a same phase in rotation direction to the crankshaft, a guide plate 43 capable of rotating as one unit with an intake side camshaft 34 and rotating relatively to the driven member, a weight ball 44 retained between the driven member and radial guide grooves 51, 52 of the guide plate and transmitting rotation of the driven member to the guide plate, and an urging member 45 urging the driven member in a direction approaching the guide plate. Centrifugal force acts on the weight ball 44 and the weight ball moves radial direction outward in the guide groove. Consequently, the driven member moves in an axial direction with resisting urging force of the urging member, and the guide plate rotates relatively to the driven member. COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、クランクシャフトに対するカムシャフトの回転方向の位相を変化させるカムシャフト位相可変装置を備えて、吸気バルブ、排気バルブのバルブタイミングを変更可能なエンジンの動弁装置に関する。 The present invention relates to a valve operating apparatus for an engine that includes a camshaft phase varying device that changes a phase of a camshaft in a rotational direction with respect to a crankshaft and that can change valve timings of an intake valve and an exhaust valve.

一般に、エンジンには吸、排気バルブを、クランクシャフトの回転と同期したタイミング（即ち、クランクシャフトと回転方向の位相が同一のタイミング）で開閉させる動弁装置が設置されている。しかしながら、このような動弁装置を備えたエンジンでは、吸気バルブ及び排気バルブの最適なバルブタイミングが、エンジンの運転状態（例えばエンジン回転数やエンジン負荷）などによって変化することが知られている。そこで、近年、エンジンの運転状態などに応じて吸気バルブ、排気バルブのバルブタイミングを変化させるバルブタイミング可変装置を備えた動弁装置を有するエンジンが提案されている。 In general, an engine is provided with a valve operating device that opens and closes intake and exhaust valves at a timing synchronized with the rotation of the crankshaft (that is, at the same timing in the rotational direction as the crankshaft). However, in an engine equipped with such a valve operating device, it is known that the optimum valve timings of the intake valve and the exhaust valve change depending on the operating state of the engine (for example, the engine speed and engine load). Therefore, in recent years, an engine having a valve operating device including a valve timing variable device that changes the valve timing of the intake valve and the exhaust valve in accordance with the operating state of the engine has been proposed.

上述のバルブタイミング可変装置は、そのほとんどが高圧の作動油を用いるものであり、例えば特許文献１に記載のように、カムシャフトに油路が形成されている。この特許文献１の可変バルブタイミング制御装置では、作動油圧を制御する油圧制御弁を廃止し、カムシャフトに配置されたシャッタバルブを、当該カムシャフトの回転時に生ずる遠心力の作用で作動させて上記油路を開閉し、カムシャフトのクランクシャフトに対する回転方向の位相を変化させて、吸気バルブのバルブタイミングを変更している。 Most of the valve timing variable devices described above use high-pressure hydraulic oil. For example, as described in Patent Document 1, an oil passage is formed in the camshaft. In the variable valve timing control device of Patent Document 1, the hydraulic control valve for controlling the operating hydraulic pressure is abolished, and the shutter valve disposed on the camshaft is operated by the action of centrifugal force generated when the camshaft rotates. The valve timing of the intake valve is changed by opening and closing the oil passage and changing the rotational phase of the camshaft relative to the crankshaft.

また、機械式のバルブタイミング可変装置も提案されている。このような機械式のバルブタイミング可変装置は、油圧式の場合よりも応答性が優れ、また、オイルポンプが不要なためメカニカルロスを低減でき、更に、作動油の油温や粘度による動作特性の不安定を解消できる等の利点がある。 A mechanical valve timing variable device has also been proposed. Such a mechanical valve timing variable device is more responsive than the hydraulic type, and can reduce mechanical loss because it does not require an oil pump. There is an advantage that instability can be eliminated.

例えば、特許文献２のバルブタイミング可変制御装置では、カムシャフトが高回転すると端部が拡開するウェイト部を設け、このウェイト部の拡開端部の反対側に爪部を設け、この爪部がカムシャフトの凹部に係止することで、このカムシャフトを軸方向にスライドさせる。カムシャフトには軸方向に２つのカムプロフィールが設けられているので、これらのカムプロフィールが選択されることで吸気バルブ、排気バルブのバルブタイミングが変更される。 For example, in the variable valve timing control device of Patent Document 2, a weight portion whose end portion expands when the camshaft rotates at a high speed is provided, and a claw portion is provided on the opposite side of the expanded end portion of the weight portion. The camshaft is slid in the axial direction by engaging with the recess of the camshaft. Since the camshaft is provided with two cam profiles in the axial direction, the valve timings of the intake valve and the exhaust valve are changed by selecting these cam profiles.

また、特許文献３のバルブタイミング制御装置では、カムシャフトが高回転するときに低速用カムシャフトに作用する遠心力によってこのウェイトが開いて低速ロックピンが引き抜かれ、ドリブンスプロケット（クランクシャフト）に対してカムシャフトが相対回転した後、高速用ウェイトが開いて高速ロックピンがカムシャフトに挿入され、当該カムシャフトが高速用位相に変更され、これにより吸気バルブのバルブタイミングが変更される。
特開平６−１８５３１６号公報実開昭６２−１５６１０８号公報特開２００６−１７０１１７号公報 Further, in the valve timing control device of Patent Document 3, the weight is opened by the centrifugal force acting on the low-speed camshaft when the camshaft rotates at a high speed, and the low-speed lock pin is pulled out, so that the driven sprocket (crankshaft) After the camshaft rotates relatively, the high-speed weight opens and the high-speed lock pin is inserted into the camshaft, and the camshaft is changed to the high-speed phase, thereby changing the valve timing of the intake valve.
JP-A-6-185316 Japanese Utility Model Publication No. 62-156108 JP 2006-170117 A

ところが、特許文献１を含めた油圧式のバルブタイミング可変装置では、作動油の温度や粘度によって動作特性が不安定になり、また、オイルポンプの駆動により油圧を生じさせて動作させるため応答性が低く、更に、カムシャフトに油路が形成されるためカムシャフトが大型化したり、高精度な油路が必要となることから製造コストが上昇してしまう。 However, in the hydraulic valve timing variable device including Patent Document 1, the operating characteristics become unstable due to the temperature and viscosity of the hydraulic oil, and the oil pump is driven to generate the hydraulic pressure to operate. Further, since the oil passage is formed in the camshaft, the camshaft is increased in size and a highly accurate oil passage is required, resulting in an increase in manufacturing cost.

また、特許文献２のバルブタイミング可変制御装置では、カムシャフトが軸方向にスライドする方式であるため、このカムシャフトを収容するシリンダヘッド周りの寸法が大きくなり、エンジンの小型化の妨げとなる。 Further, in the variable valve timing control device of Patent Document 2, since the camshaft slides in the axial direction, the size around the cylinder head that accommodates the camshaft increases, which hinders the downsizing of the engine.

更に、特許文献３のバルブタイミング制御装置では、バルブスプリングの付勢力が吸気カムに作用することで、カムシャフトがドリブンスプロケット（クランクシャフト）に対して相対回転する構成であり、ドリブンスプロケットに対するカムシャフトの相対回転の禁止／許容を切り替えるだけであって、これらに積極的に相対回転を生じさせるものではない。従って、バルブタイミングが能動的に変更されるものではないので、バルブタイミングの切り換えに際し応答遅れが生じやすい。 Furthermore, in the valve timing control device of Patent Document 3, the camshaft rotates relative to the driven sprocket (crankshaft) by the biasing force of the valve spring acting on the intake cam, and the camshaft with respect to the driven sprocket. The relative rotation is only prohibited / permitted, and does not actively cause relative rotation. Therefore, since the valve timing is not actively changed, a response delay tends to occur when the valve timing is switched.

本発明の目的は、上述の事情を考慮してなされたものであり、バルブタイミングの変更に関し動作特性が安定化し、且つ応答性が良好であると共に、装置の大型化及び製造コストの上昇を回避できるエンジンの動弁装置を提供することにある。 The object of the present invention has been made in consideration of the above-mentioned circumstances, stabilizes the operation characteristics regarding the change of the valve timing, has good response, and avoids the increase in the size of the apparatus and the increase in the manufacturing cost. An object of the present invention is to provide a valve operating device for an engine.

本発明は、クランクシャフトと、このクランクシャフトにより駆動され、バルブを駆動するカムを備えたカムシャフトと、このカムシャフトに設けられ、前記クランクシャフトに対する当該カムシャフトの回転方向の位相を変化させるカムシャフト位相可変装置と、を有するエンジンの動弁装置において、前記カムシャフト位相可変装置は、前記クランクシャフトにより駆動され、前記クランクシャフトに対する回転方向の位相が同一の従動部材と、前記カムシャフトと一体に回転すると共に、前記従動部材に対して相対回転可能なガイドプレートと、前記従動部材及び前記ガイドプレートの相互に対向する面にそれぞれ形成された放射状のガイド溝間に保持されて、前記従動部材の回転を前記ガイドプレートへ伝達するウェイトボールと、前記従動部材と前記ガイドプレートの少なくとも一方に、これらの従動部材及びガイドプレートを互いに接近する方向に付勢する付勢力を付与する付勢部材とを有し、前記従動部材と前記ガイドプレートのガイド溝は、径方向外方に向かうに従って互いのガイド溝の底部が近づくよう形成されると共に、少なくとも一方のガイド溝が径方向に対して周方向一方側に傾斜して形成され、前記ウェイトボールに遠心力が作用して当該ウェイトボールが前記ガイド溝内を径方向外方に移動することにより、前記従動部材が前記付勢部材の付勢力に抗して軸方向に移動すると共に、前記ガイドプレートが前記従動部材に対して所定量相対回転するよう構成されたことを特徴とするものである。 The present invention includes a crankshaft, a camshaft that is driven by the crankshaft and includes a cam that drives a valve, and a cam that is provided on the camshaft and changes a phase of the camshaft relative to the crankshaft. In the valve operating apparatus for an engine having a shaft phase varying device, the camshaft phase varying device is driven by the crankshaft, and a driven member having the same rotational direction phase with respect to the crankshaft, and the camshaft are integrated. And a guide plate that is rotatable relative to the driven member, and is held between radial guide grooves respectively formed on mutually opposing surfaces of the driven member and the guide plate, and the driven member A weight ball that transmits the rotation of the guide plate to the guide plate; A biasing member that applies a biasing force that biases the driven member and the guide plate in a direction approaching each other is provided on at least one of the driven member and the guide plate, the guide of the driven member and the guide plate The grooves are formed so that the bottoms of the guide grooves approach each other as they go outward in the radial direction, and at least one guide groove is formed to be inclined in the circumferential direction on one side with respect to the radial direction. When the centrifugal force is applied and the weight ball moves radially outward in the guide groove, the driven member moves in the axial direction against the urging force of the urging member, and the guide plate Is configured to rotate relative to the driven member by a predetermined amount.

本発明によれば、カムシャフト位相可変装置は、遠心力によりウェイトボールがガイド溝内を移動することで、従動部材に対してガイドプレートを相対回転させるため、簡単な構造で確実にバルブタイミングを変更でき、バルブタイミングの変更に関し動作特性が安定化して信頼性が向上すると共に、応答性も向上する。また、ガイドプレートを相対回転させてカムシャフトを周方向に回転させる構造であり、カムシャフトを軸方向にスライドさせる構造ではないので、シリンダヘッド周りを含めた装置の小型化を実現できる。更に、作動油を一切用いない機械式のカムシャフト位相可変装置であるため、カムシャフトに油室や油路を形成するスペースが不要となり、カムシャフトの大型化に伴う装置の大型化を回避できると共に、油路形成などの機械加工を省略できるので製造コストの上昇を回避できる。 According to the present invention, the camshaft phase varying device rotates the guide plate relative to the driven member by moving the weight ball in the guide groove by centrifugal force, so that the valve timing can be reliably ensured with a simple structure. It can be changed, and the operation characteristics are stabilized and the reliability is improved with respect to the change of the valve timing, and the responsiveness is also improved. Further, since the cam plate is rotated in the circumferential direction by relatively rotating the guide plate and not the structure in which the cam shaft is slid in the axial direction, the apparatus including the cylinder head can be downsized. In addition, since it is a mechanical camshaft phase variable device that does not use any hydraulic oil, a space for forming an oil chamber or an oil passage in the camshaft is not required, and the enlargement of the device accompanying the enlargement of the camshaft can be avoided In addition, since machining such as oil passage formation can be omitted, an increase in manufacturing cost can be avoided.

以下、本発明を実施するための最良の形態を、図面に基づき説明する。 The best mode for carrying out the present invention will be described below with reference to the drawings.

［Ａ］第１の実施の形態（図１〜図８）
図１は、本発明に係るエンジンの動弁装置における第１の実施の形態が適用されたエンジンを搭載する自動二輪車の右側面図である。図２は、図１のエンジンの上部を示す部分右側面図である。図３は、図２のIII−III線に沿う断面図である。 [A] First embodiment (FIGS. 1 to 8)
FIG. 1 is a right side view of a motorcycle equipped with an engine to which the first embodiment of the valve operating apparatus for an engine according to the present invention is applied. FIG. 2 is a partial right side view showing an upper portion of the engine of FIG. 3 is a cross-sectional view taken along line III-III in FIG.

図１に示す自動二輪車１は、メインフレーム２とリヤフレーム３からなる車体フレーム４の前頭部に形成されたヘッドパイプ（不図示）に、前輪５を支持するフロントフォーク６が、ハンドルバー７やフロントフェンダー９等と共に左右回動自在に軸支され、メインフレーム２の後下部に架設されたピボット軸１１に、後輪１２を支持するスイングアーム１３が上下揺動自在に軸支されている。フロントフォーク６の上部及びヘッドパイプの前方にフロントカバー８が設けられている。 A motorcycle 1 shown in FIG. 1 includes a front fork 6 that supports a front wheel 5 on a head pipe (not shown) formed on a front head of a vehicle body frame 4 including a main frame 2 and a rear frame 3. A swing arm 13 that supports the rear wheel 12 is pivotally supported by a pivot shaft 11 that is pivotally supported in the left and right direction together with the front fender 9 and the like, and is installed in the rear lower portion of the main frame 2. . A front cover 8 is provided above the front fork 6 and in front of the head pipe.

また、メインフレーム２に懸架されるようにしてエンジン１０が搭載され、このエンジン１０の上方に燃料タンク１４が配置され、リヤフレーム３上にライダーシート１５とピリオンシート１６が載置され、これらのシート１５、１６の下方かつエンジン１０の後方にサイドカバー１７が設けられている。 An engine 10 is mounted so as to be suspended from the main frame 2, a fuel tank 14 is disposed above the engine 10, and a rider seat 15 and a pillion seat 16 are placed on the rear frame 3. A side cover 17 is provided below the seats 15 and 16 and behind the engine 10.

エンジン１０は、図２に示すように、クランクケース１８に前後二つのシリンダ部１９Ｆ、１９Ｒが設置された４サイクルＶ型２気筒エンジンである。このエンジン１０の動力は、クランクケース１８に配置されたクランクシャフト２１から、トランスミッション及びドライブチェーン（共に図示せず）を介して後輪１２へ伝達される。 As shown in FIG. 2, the engine 10 is a four-cycle V-type two-cylinder engine in which two cylinder parts 19 F and 19 R are installed in a crankcase 18. The power of the engine 10 is transmitted from the crankshaft 21 disposed in the crankcase 18 to the rear wheel 12 via a transmission and a drive chain (both not shown).

各シリンダ部１９Ｆ、１９Ｒは、図示しないピストンを収容するシリンダブロック２２と、吸気バルブ及び排気バルブ（共に図示せず）を収容するシリンダヘッド２３と、シリンダヘッド２３の上部開口を覆うヘッドカバー２４とが順次連設されて構成される。また、このエンジン１０は、吸気バルブ及び排気バルブを駆動する動弁装置２０を備える。この動弁装置２０は、本実施の形態ではＤＯＨＣ（ＤｏｕｂｌｅＯｖｅｒＨｅａｄＣａｍｓｈａｆｔ）型式である。 Each cylinder portion 19F, 19R includes a cylinder block 22 that houses a piston (not shown), a cylinder head 23 that houses an intake valve and an exhaust valve (both not shown), and a head cover 24 that covers an upper opening of the cylinder head 23. Consecutively connected. The engine 10 also includes a valve gear 20 that drives an intake valve and an exhaust valve. This valve operating device 20 is a DOHC (Double Overhead Camshaft) type in the present embodiment.

この動弁装置２０は、クランクケース１８に配設されて、シャフトドライブギア２５を回転一体に備えたクランクシャフト２１と、クランクケース１８に配設されて、回転一体のシャフトドリブンギア２６及びカムドライブスプロケット２７を備えたカムドライブシャフト２８と、シリンダヘッド２３に配設されて、回転一体のアイドルドリブンスプロケット２９及びアイドルドライブギア３０を備えたアイドルシャフト３１と、シリンダヘッド２３及びヘッドカバー２４間に配設されると共に、吸気カム３２が一体に形成され、吸気側カムドリブンギア３３を備える吸気側カムシャフト３４と、シリンダヘッド２３とヘッドカバー２４間に配設されると共に、排気カム３５が一体に形成され、排気側カムドリブンギア３６を回転一体に備えた排気側カムシャフト３７と、吸気側カムシャフト３４と吸気側カムドリブンギア３３との間に配設されたカムシャフト位相可変装置４０（図３）と、を有して構成される。 The valve gear 20 is disposed in the crankcase 18 and is provided with a crankshaft 21 that is integrally provided with a shaft drive gear 25, and a shaft-driven gear 26 and cam drive that are disposed on the crankcase 18 and are integrally rotated. A cam drive shaft 28 having a sprocket 27 and a cylinder head 23, and an idle shaft 31 having a rotation-integrated idle driven sprocket 29 and an idle drive gear 30, and a cylinder head 23 and a head cover 24. In addition, the intake cam 32 is integrally formed, and is disposed between the intake side camshaft 34 including the intake side cam driven gear 33, the cylinder head 23 and the head cover 24, and the exhaust cam 35 is formed integrally. The exhaust side cam driven gear 36 is integrated with the rotation. An exhaust-side camshaft 37, and a, a cam shaft phase variable device 40 disposed (FIG. 3) between the intake side camshaft 34 and the intake side cam driven gear 33.

図２に示すように、シャフトドライブギア２５がシャフトドリブンギア２６に噛み合って、クランクシャフト２１の駆動力が、これらのシャフトドライブギア２５及びシャフトドリブンギア２６を介してカムドライブスプロケット２７に伝達される。このカムドライブスプロケット２７とアイドルドリブンスプロケット２９間にカムチェーン３８が巻き掛けられて、クランクシャフト２１の駆動力が、これらのカムドライブスプロケット２７、カムチェーン３８及びアイドルドリブンスプロケット２９を経てアイドルドライブギア３０へ伝達される。このアイドルドライブギア３０と吸気側カムドリブンギア３３及び排気側カムドリブンギア３６とが噛み合い、これらの吸気側カムドリブンギア３３及び排気側カムドリブンギア３６は、クランクシャフト２１と回転方向に同一の位相で回転する。このうち、排気側カムドリブンギア３６が排気側カムシャフト３７と回転一体であることから、排気側カムシャフト３７の排気カム３５は、クランクシャフト２１により駆動されて、このクランクシャフト２１と回転方向に同一の位相で回転駆動され、排気バルブを開閉駆動する。 As shown in FIG. 2, the shaft drive gear 25 meshes with the shaft driven gear 26, and the driving force of the crankshaft 21 is transmitted to the cam drive sprocket 27 via the shaft drive gear 25 and the shaft driven gear 26. . A cam chain 38 is wound between the cam drive sprocket 27 and the idle driven sprocket 29, and the driving force of the crankshaft 21 passes through the cam drive sprocket 27, the cam chain 38, and the idle driven sprocket 29, and the idle drive gear 30. Is transmitted to. The idle drive gear 30, the intake side cam driven gear 33, and the exhaust side cam driven gear 36 mesh with each other, and these intake side cam driven gear 33 and exhaust side cam driven gear 36 have the same phase in the rotational direction as the crankshaft 21. Rotate with. Among these, since the exhaust side cam driven gear 36 is integrally rotated with the exhaust side camshaft 37, the exhaust cam 35 of the exhaust side camshaft 37 is driven by the crankshaft 21 in the rotational direction. It is rotationally driven at the same phase, and opens and closes the exhaust valve.

また、吸気側カムシャフト３４と吸気側カムドリブンギア３３との間に設けられた前記カムシャフト位相可変装置４０は、クランクシャフト２１に対する吸気側カムシャフト３４の回転方向の位相を変化させるものである。従って、吸気側カムシャフト３４の吸気カム３２は、クランクシャフト２１により駆動されて、このクランクシャフト２１と回転方向に同一の位相または異なった位相で回転駆動され、吸気バルブを開閉駆動する。尚、カムチェーン３８は、チェーンガイド３９に案内されると共に、チェーンテンショナ４１によりその緩みが抑制される。 The camshaft phase varying device 40 provided between the intake side camshaft 34 and the intake side cam driven gear 33 changes the phase in the rotational direction of the intake side camshaft 34 with respect to the crankshaft 21. . Accordingly, the intake cam 32 of the intake camshaft 34 is driven by the crankshaft 21 and is rotationally driven in the same or different phase in the rotational direction with respect to the crankshaft 21 to open and close the intake valve. The cam chain 38 is guided by the chain guide 39 and its loosening is suppressed by the chain tensioner 41.

さて、図３に示すカムシャフト位相可変装置４０は、エンジン１０の運転状態に応じて、吸気バルブと排気バルブの少なくとも一方（本実施の形態では吸気バルブ）のバルブタイミングを制御して、吸気バルブの開時期と排気バルブの開時期とが重なるバルブオーバーラップを調整するものである。例えば、エンジン１０の低回転時には、バルブオーバーラップを小さく設定して吸気の吹き抜けを防止し、トルク及び燃費を向上させると共に、排気中への有害物質の排出を抑制する。また、エンジン１０の高回転時にはバルブオーバーラップを大きく設定して、吸気の慣性を利用して吸気効率を高め、エンジン１０の出力を向上させる。 Now, the camshaft phase varying device 40 shown in FIG. 3 controls the valve timing of at least one of the intake valve and the exhaust valve (intake valve in the present embodiment) according to the operating state of the engine 10, This adjusts the valve overlap in which the opening timing of the exhaust gas and the opening timing of the exhaust valve overlap. For example, when the engine 10 is running at a low speed, the valve overlap is set small to prevent the intake air from being blown through, thereby improving the torque and fuel consumption and suppressing the discharge of harmful substances into the exhaust. Further, the valve overlap is set to be large when the engine 10 is rotating at high speed, the intake efficiency is increased by utilizing the inertia of the intake air, and the output of the engine 10 is improved.

このカムシャフト位相可変装置４０は、図３及び図４に示すように、従動部材４２、ガイドプレート４３、ウェイトボール４４、付勢部材４５及び筒状部材４６を有して構成される。従動部材４２は、外周面に動力受部としての前記吸気側カムドリブンギア３３が形成され、クランクシャフト２１により駆動され、このクランクシャフト２１に対する回転方向の位相が同一に設けられる。また、ガイドプレート４３は、吸気側カムシャフト３４に回転一体に設けられると共に、従動部材４２に対して相対回転可能に設けられる。また、ウェイトボール４４は、従動部材４２とガイドプレート４３のガイド溝５１、５２（後述）間に保持されて、従動部材４２の回転をガイドプレート４３へ伝達する。更に、付勢部材４５は、従動部材４２とガイドプレート４３とを互いに接近する方向に常時付勢する。また、筒状部材４６は、摺動面部４７及び座面受部４８を備える。 As shown in FIGS. 3 and 4, the camshaft phase varying device 40 includes a driven member 42, a guide plate 43, a weight ball 44, a biasing member 45, and a cylindrical member 46. The driven member 42 is formed with the intake side cam driven gear 33 as a power receiving portion on the outer peripheral surface thereof, and is driven by the crankshaft 21, and is provided with the same rotational phase with respect to the crankshaft 21. Further, the guide plate 43 is provided integrally with the intake side camshaft 34 so as to be rotatable relative to the driven member 42. Further, the weight ball 44 is held between the driven member 42 and guide grooves 51 and 52 (described later) of the guide plate 43, and transmits the rotation of the driven member 42 to the guide plate 43. Further, the urging member 45 constantly urges the driven member 42 and the guide plate 43 in a direction in which they are close to each other. The tubular member 46 includes a sliding surface portion 47 and a seat surface receiving portion 48.

更に詳説すると、従動部材４２は、図３及び図５に示すように、吸気側カムドリブンギア３３の内周側に周壁部４９が形成され、この周壁部４９の内壁面５０にガイドプレート４３の外周面が軸方向に摺接可能に設けられる。また、この従動部材４２には、周壁部４９の内側部分でガイドプレート４３に対向する面に、放射状のガイド溝５１が複数形成される。このガイド溝５１は、ウェイトボール４４を案内するものであり、溝深さが一定に形成されると共に、従動部材４２の径方向に対し周方向一方側に角度θ（図５（Ｂ））だけ傾斜して形成される。 More specifically, as shown in FIGS. 3 and 5, the driven member 42 has a peripheral wall portion 49 formed on the inner peripheral side of the intake side cam driven gear 33, and the guide plate 43 is formed on the inner wall surface 50 of the peripheral wall portion 49. The outer peripheral surface is provided so as to be slidable in the axial direction. The driven member 42 is formed with a plurality of radial guide grooves 51 on a surface facing the guide plate 43 at the inner portion of the peripheral wall portion 49. The guide groove 51 guides the weight ball 44, has a constant groove depth, and has an angle θ (FIG. 5B) on one side in the circumferential direction with respect to the radial direction of the driven member. Inclined.

ガイドプレート４３は、図３及び図６に示すように、従動部材４２と対向する面に放射状のガイド溝５２が複数形成される。このガイド溝５２は、ウェイトボール４４を案内するものであり、ガイドプレート４３の径方向に沿って形成される。また、このガイド溝５２には、ガイドプレート４３の径方向外方へ向かうに従って溝深さが浅くなる勾配が設けられると共に、この勾配は、ガイドプレート４３の径方向外方へ向かうに従って急峻になるよう構成される。つまり、ガイド溝５２の溝深さの勾配は、ガイドプレート４３の径方向内側が勾配αであり、外側が勾配β（β＞α）に設定される。勾配αと勾配βは、ガイド溝５２底部のある一点（図６（Ｂ）の点Ｘ）を境に切り替えられている。このガイド溝５２の勾配α及びβによって、従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２とは、径方向外側へ向かうに従って互いの溝底部が接近するよう構成される。 As shown in FIGS. 3 and 6, the guide plate 43 has a plurality of radial guide grooves 52 formed on the surface facing the driven member 42. The guide groove 52 guides the weight ball 44 and is formed along the radial direction of the guide plate 43. In addition, the guide groove 52 is provided with a gradient in which the groove depth becomes shallower as it goes outward in the radial direction of the guide plate 43, and this gradient becomes steeper as it goes outward in the radial direction of the guide plate 43. It is configured as follows. That is, the gradient of the groove depth of the guide groove 52 is set to the gradient α on the radially inner side of the guide plate 43 and the gradient β (β> α) on the outer side. The gradient α and the gradient β are switched with respect to one point (point X in FIG. 6B) at the bottom of the guide groove 52. Due to the gradients α and β of the guide groove 52, the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43 are configured such that the groove bottoms approach each other as they go radially outward.

図３に示すウェイトボール４４は、鋼やタングステンなどのように比重の大きな材料にて構成される。また、付勢部材４５は、本実施の形態では皿ばねが用いられているが、波板ばね、渦巻ばね（竹の子ばね）等であってもよい。 The weight ball 44 shown in FIG. 3 is made of a material having a large specific gravity such as steel or tungsten. The biasing member 45 is a disc spring in the present embodiment, but may be a corrugated spring, a spiral spring (bamboo spring), or the like.

筒状部材４６は、ボルト５３を用いて吸気側カムシャフト３４の一端面に結合され、この吸気側カムシャフト３４側に摺動面部４７が、この摺動面部４７と軸方向反対側の端部に座面受部４８がそれぞれ設けられる。摺動面部４７は、従動部材４２の内周面に摺接可能に設けられて、従動部材４２の軸方向移動を案内する。また、座面受部４８は、付勢部材４５の座面５５を支持して、従動部材４２との間に付勢部材４５を介在する。これにより、付勢部材４５の付勢力が従動部材４２に付与される。また、この筒状部材４６には、摺動面部４７と座面受部４８との間に、従動部材４２が当接可能な段部５４が形成され、この段部５４によって従動部材４２の摺動範囲が規定される。 The cylindrical member 46 is coupled to one end surface of the intake side camshaft 34 using a bolt 53, and a sliding surface portion 47 is provided on the intake side camshaft 34 side, and an end portion on the opposite side to the sliding surface portion 47 in the axial direction. Each is provided with a seat surface receiving portion 48. The sliding surface portion 47 is provided so as to be slidable on the inner peripheral surface of the driven member 42 and guides the axial movement of the driven member 42. The seat surface receiving portion 48 supports the seat surface 55 of the urging member 45 and interposes the urging member 45 with the driven member 42. Thereby, the urging force of the urging member 45 is applied to the driven member 42. Further, the cylindrical member 46 is formed with a step portion 54 with which the driven member 42 can abut between the sliding surface portion 47 and the seat surface receiving portion 48, and the step portion 54 slides the driven member 42. A moving range is defined.

次に、作用を説明する。 Next, the operation will be described.

図７に示すように、エンジン９が低回転域にあるときには、ウェイトボール４４に作用する遠心力が小さく、このウェイトボール４４はガイドプレート４３のガイド溝５２の勾配αと付勢部材４５の付勢力との作用で、ガイド溝５１及び５２の径方向内側端の初期位置に留まる。このため、吸気側カムシャフト３４は、吸気側カムドリブンギア３３つまりクランクシャフト２１と回転方向の位相が同一となり、この吸気側カムシャフト３４に一体に形成された吸気カム３２は、組み付け時の位相で吸気バルブを駆動する。これにより、吸気バルブと排気バルブは、バルブオーバーラップの小さな低速用バルブタイミングとなり、トルク及び燃費が向上し、有害物質の排出が抑制される。 As shown in FIG. 7, when the engine 9 is in the low rotation range, the centrifugal force acting on the weight ball 44 is small, and the weight ball 44 is applied to the gradient α of the guide groove 52 of the guide plate 43 and the biasing member 45. The action of the force remains at the initial position of the radially inner ends of the guide grooves 51 and 52. For this reason, the intake side camshaft 34 has the same rotational phase as the intake side cam driven gear 33, that is, the crankshaft 21, and the intake cam 32 formed integrally with the intake side camshaft 34 has a phase during assembly. To drive the intake valve. Thereby, the intake valve and the exhaust valve become low-speed valve timing with a small valve overlap, and torque and fuel consumption are improved, and emission of harmful substances is suppressed.

図８に示すように、エンジン９が高回転域に至ると、ウェイトボール４４に作用する遠心力が大きくなり、このウェイトボール４４は従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２内を径方向外方へ向かって移動する。これにより、従動部材４２は、ガイドプレート４３のガイド溝５２の勾配α及びβの作用で、付勢部材４５の付勢力に抗して、吸気側カムシャフト３４の軸方向外方側（矢印Ａ方向）へ移動する。このとき、従動部材４２のガイド溝５１には径方向に対して周方向一方側に角度θ(図５)の傾斜が設けられているので、ガイドプレート４３は、ガイド溝５１の傾斜方向（図８(Ｂ)及び(Ｃ)の矢印Ｂ方向）に従動部材４２に対して上記角度θだけ相対回転する。 As shown in FIG. 8, when the engine 9 reaches a high rotation range, the centrifugal force acting on the weight ball 44 increases, and the weight ball 44 is inserted into the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43. Is moved radially outward. As a result, the driven member 42 acts against the urging force of the urging member 45 by the action of the gradients α and β of the guide groove 52 of the guide plate 43 (see the arrow A). Direction). At this time, since the guide groove 51 of the driven member 42 is inclined at an angle θ (FIG. 5) on one side in the circumferential direction with respect to the radial direction, the guide plate 43 is inclined in the direction of inclination of the guide groove 51 (see FIG. 8 (B) and (C) in the direction of arrow B) relative to the driven member 42 by the angle θ.

これにより、吸気側カムシャフト３４は、クランクシャフト２１に対して回転方向の位相が変化する。このときの吸気側カムシャフト３４の位相の変化は、吸気側カムシャフト３４の回転方向（進角側）である。従って、この吸気側カムシャフト３４に一体に形成された吸気カム３２は、組み付け時の位相よりも進角側へ変化した位相で吸気バルブを駆動する。この結果、吸気バルブと排気バルブは、バルブオーバーラップが大きな高速用バルブタイミングとなり、エンジン１０の出力が向上する。 As a result, the intake camshaft 34 changes its rotational phase relative to the crankshaft 21. The change in the phase of the intake side camshaft 34 at this time is the rotational direction (advance side) of the intake side camshaft 34. Accordingly, the intake cam 32 formed integrally with the intake side camshaft 34 drives the intake valve at a phase that has changed to the advance side from the phase at the time of assembly. As a result, the intake valve and the exhaust valve have a high valve timing with a large valve overlap, and the output of the engine 10 is improved.

エンジン１０の回転数が低下すると、ウェイトボール４４に作用する遠心力が小さくなるため、遠心力によって従動部材４２を矢印Ａ方向に移動させる力よりも付勢部材４５による付勢力の方が勝り、付勢部材４５の付勢力の作用で従動部材４２がガイドプレート４３側へ移動し、ウェイトボール４４がガイド溝５１及び５２の径方向内側へ移動して、従動部材４２及びウェイトボール４４は、やがて図７に示す原位置に復帰する。ウェイトボール４４の原位置への復帰に伴い、ガイドプレート４３は、従動部材４２に対して遅角側（図８（Ｂ）及び（Ｃ）の矢印Ｂ方向の反対方向）に相対回転し、吸気側カムシャフト３４はクランクシャフト２１に対して遅角側へ位相を変化させる。この結果、吸気バルブと排気バルブは、バルブオーバーラップが小さな低速用バルブタイミングとなり、エンジン１０の出力が減少する。 When the rotational speed of the engine 10 decreases, the centrifugal force acting on the weight ball 44 decreases, so the biasing force by the biasing member 45 is superior to the force that moves the driven member 42 in the direction of arrow A by the centrifugal force. The driven member 42 moves to the guide plate 43 side by the action of the urging force of the urging member 45, the weight ball 44 moves inward in the radial direction of the guide grooves 51 and 52, and the driven member 42 and the weight ball 44 eventually become. Return to the original position shown in FIG. As the weight ball 44 returns to the original position, the guide plate 43 rotates relative to the driven member 42 in the retarded direction (the direction opposite to the arrow B direction in FIGS. 8B and 8C), The side camshaft 34 changes the phase toward the retard side with respect to the crankshaft 21. As a result, the intake valve and the exhaust valve have low valve timing with a small valve overlap, and the output of the engine 10 decreases.

以上のように構成されたことから、本実施の形態によれば、次の効果（１）〜（１１）を奏する。 With the configuration as described above, the following effects (1) to (11) are achieved according to the present embodiment.

（１）カムシャフト位相可変装置４０は、遠心力によりウェイトボール４４が従動部材４２のガイド溝５１及びガイドプレート４３のガイド溝５２内を移動することで、従動部材４２に対してガイドプレート４３を相対回転させ、クランクシャフト２１に対する吸気側カムシャフト３４の回転方向の位相を変化させる。このため、簡単な構造で確実に吸気バルブのバルブタイミングを変更でき、バルブタイミングの変更に関し動作特性が安定化して信頼性が向上すると共に、応答性も向上する。 (1) The camshaft phase varying device 40 moves the guide plate 43 relative to the driven member 42 by moving the weight ball 44 in the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43 by centrifugal force. The phase of the rotation direction of the intake camshaft 34 with respect to the crankshaft 21 is changed by relative rotation. For this reason, the valve timing of the intake valve can be reliably changed with a simple structure, and the operation characteristics are stabilized and reliability is improved with respect to the change of the valve timing, and the responsiveness is also improved.

（２）ガイドプレート４３を相対回転させて吸気側カムシャフト３４を周方向に回転させる構造であり、吸気側カムシャフト３４を軸方向にスライドさせる構造ではないので、シリンダヘッド２３周りを含めた動弁装置２０ひいてはエンジン１０の小型化を実現できる。 (2) The structure is such that the guide plate 43 is relatively rotated to rotate the intake side camshaft 34 in the circumferential direction, and the intake side camshaft 34 is not slid in the axial direction. The valve device 20 and thus the engine 10 can be reduced in size.

（３）作動油を一切用いない機械式のカムシャフト位相可変装置４０であるため、吸気側カムシャフト３４に油室や油路を形成するスペースが不要となり、この吸気側カムシャフト３４の大型化に伴う動弁装置２０ひいてはエンジン１０の大型化を回避できる。更に、油路形成などの機械加工を省略できるので、製造コストの上昇を防止できる。 (3) Since the mechanical camshaft phase varying device 40 does not use any hydraulic oil, a space for forming an oil chamber or an oil passage in the intake side camshaft 34 is not required, and the intake side camshaft 34 is enlarged. Accordingly, it is possible to avoid an increase in the size of the valve gear 20 and the engine 10. Furthermore, since machining such as oil passage formation can be omitted, an increase in manufacturing cost can be prevented.

（４）従動部材４２の外周に動力受部として吸気側カムドリブンギア３３が形成されたので、この吸気側カムドリブンギア３３の内周側に、ウェイトボール４４の最大位置を位置決めするための周壁部４９を形成できる。仮に、ガイドプレート４３に周壁部を形成すると、ウェイトボール４４のストロークを確保する必要上、ガイドプレート４３自体が径方向に大型化する。更に、ガイドプレート４３には従動部材４２が外嵌されるため、従動部材４２の外形寸法が大きくなり、カムシャフト位相可変装置４０が大型化してしまう。これに対し、従動部材４２に周壁部４９を形成することで、ガイドプレート４３側に周壁部を形成する場合に比べて従動部材４２の外形寸法を抑制でき、カムシャフト位相可変装置４０を小型化できる。 (4) Since the intake side cam driven gear 33 is formed on the outer periphery of the driven member 42 as a power receiving portion, the peripheral wall for positioning the maximum position of the weight ball 44 on the inner peripheral side of the intake side cam driven gear 33 A portion 49 can be formed. If the peripheral wall portion is formed on the guide plate 43, the guide plate 43 itself is enlarged in the radial direction in order to secure the stroke of the weight ball 44. Furthermore, since the driven member 42 is fitted on the guide plate 43, the outer dimension of the driven member 42 is increased, and the camshaft phase varying device 40 is increased in size. On the other hand, by forming the peripheral wall portion 49 on the driven member 42, the outer dimension of the driven member 42 can be suppressed as compared with the case where the peripheral wall portion is formed on the guide plate 43 side, and the camshaft phase varying device 40 is downsized. it can.

（５）従動部材４２の周壁部４９の内壁面５０に沿ってガイドプレート４３が摺動するので、この従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２との間に異物の侵入を防止でき、ウェイトボール４４の摺動抵抗の増大を回避できる。その結果、吸気バルブのバルブタイミング切替特性の変化や、カムシャフト位相可変装置４０の性能劣化を未然に防止できる。 (5) Since the guide plate 43 slides along the inner wall surface 50 of the peripheral wall portion 49 of the driven member 42, foreign matter enters between the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43. This can prevent the sliding resistance of the weight ball 44 from increasing. As a result, it is possible to prevent changes in the valve timing switching characteristics of the intake valves and performance deterioration of the camshaft phase varying device 40.

（６）従動部材４２には、ウェイトボール４４の受部となる周壁部４９が形成されており、この周壁部４９の軸方向寸法は、ウェイトボール４４の径よりも長尺に形成する必要がある。従って、仮に従動部材４２のガイド溝５１に勾配α、βを設けると、その分だけ従動部材４２の軸方向寸法が増大することになり、カムシャフト位相可変装置４０が大型化してしまう。これに対し、ガイドプレート４３のガイド溝５２に勾配α、βが設けられたことで、従動部材４２の軸方向寸法の増大を防止でき、カムシャフト位相可変装置４０を小型化できる。 (6) The driven member 42 has a peripheral wall portion 49 that serves as a receiving portion for the weight ball 44, and the axial dimension of the peripheral wall portion 49 needs to be longer than the diameter of the weight ball 44. is there. Accordingly, if the gradients α and β are provided in the guide groove 51 of the follower member 42, the axial dimension of the follower member 42 increases accordingly, and the camshaft phase varying device 40 becomes larger. On the other hand, since the gradients α and β are provided in the guide groove 52 of the guide plate 43, an increase in the axial dimension of the driven member 42 can be prevented, and the camshaft phase varying device 40 can be downsized.

（７）従動部材４２のガイド溝５１は、一定の溝深さに形成されると共に、従動部材４２の径方向に対して周方向一方側に角度θだけ傾斜して形成されている。径方向に対して周方向に傾斜したガイド溝５１には、ウェイトボール４４を介して従動部材４２の径方向の力が作用する。仮に、このガイド溝５１の溝深さを径方向外方へ向かうに従って浅くなるように形成した場合、このガイド溝５１は、上記径方向の力を十分に受けることができず、溝の縁に摩耗が生じて耐久性が低下したり、従動部材４２とガイドプレート４３との間に周方向の滑りが生じて、吸気側カムシャフト３４の回転方向の位相を変化させることができない恐れがある。これに対し、溝深さが一定なガイド溝５１に、径方向に対して周方向一方側に傾斜を設けたことで、上述の耐久性の低下や、従動部材４２とガイドプレート４３間の滑りの発生を確実に防止できる。 (7) The guide groove 51 of the driven member 42 is formed to have a constant groove depth and is inclined at an angle θ on one side in the circumferential direction with respect to the radial direction of the driven member 42. A radial force of the driven member 42 acts on the guide groove 51 inclined in the circumferential direction with respect to the radial direction via the weight ball 44. If the groove depth of the guide groove 51 is formed so as to become shallower outward in the radial direction, the guide groove 51 cannot sufficiently receive the radial force, and is not formed on the edge of the groove. Wear may occur and durability may be reduced, or slippage in the circumferential direction may occur between the driven member 42 and the guide plate 43, and the phase in the rotational direction of the intake camshaft 34 may not be changed. On the other hand, the guide groove 51 having a constant groove depth is provided with an inclination on one side in the circumferential direction with respect to the radial direction, so that the above-described deterioration in durability and slip between the driven member 42 and the guide plate 43 are achieved. Can be reliably prevented.

（８）エンジン１０の高回転時における吸気バルブのバルブタイミングは、吸気側カムシャフト３４（つまり吸気カム３２）の位相をエンジン１０の低回転時に比べて進角側へ変化させて得られる。従って、エンジン高回転時のバルブタイミングからエンジン低回転時のバルブタイミングへ復帰させる際には吸気側カムシャフト３４を遅角側へ位相変化させることとなり、吸気側カムシャフト３４を回転方向の慣性力に抗して減速させる必要がある。このためには、ウェイトボール４４をガイド溝５１及び５２内で従動部材４２及びガイドプレート４３の径方向内側へ速く押し戻さなければならない。 (8) The valve timing of the intake valve at the time of high rotation of the engine 10 is obtained by changing the phase of the intake camshaft 34 (that is, the intake cam 32) to the advance side as compared with the low rotation of the engine 10. Therefore, when returning from the valve timing at the time of high engine rotation to the valve timing at the time of low engine rotation, the phase of the intake side camshaft 34 is changed to the retard side, and the inertial force in the rotational direction of the intake side camshaft 34 is changed. It is necessary to slow down against this. For this purpose, the weight ball 44 has to be pushed back inwardly in the radial direction of the driven member 42 and the guide plate 43 in the guide grooves 51 and 52.

本実施の形態のごとく、ガイドプレート４３のガイド溝５２の溝底部の勾配が、ガイドプレート４３の径方向外側へ向かうに従って急峻になるよう構成されたので（勾配α＜勾配β）、ウェイトボール４４の上述の戻りを速くすることができる。また、付勢部材４５の付勢方向に対向するガイドプレート４３に、径方向外方へ向かって溝深さが浅くなる勾配を有するガイド溝５２が形成されているので、ウェイトボール４４の上述の戻りを更に速くすることができる。 As in the present embodiment, the gradient of the groove bottom portion of the guide groove 52 of the guide plate 43 is configured to be steeper toward the radially outer side of the guide plate 43 (gradient α <gradient β). The above-mentioned return can be made faster. Further, since the guide plate 52 facing the urging direction of the urging member 45 is formed with the guide groove 52 having a gradient in which the groove depth becomes shallower outward in the radial direction, the above-described weight ball 44 is provided. Return can be made even faster.

（９）吸気バルブのバルブタイミングを変更するに際して従動部材４２が軸方向に移動するため、この従動部材４２の動力受部をスプロケットとしたカムチェーン方式を採用した場合には、チェーンラインが移動することになり、また、このチェーンラインの移動に伴いチェーンテンショナ等を移動させることになるので、構造が複雑になる。これに対し、従動部材４２の動力受部がギア（吸気側カムドリブンギア３３）であって、従動部材４２の最終動力伝達をギア駆動で行う場合には、この吸気側カムドリブンギア３３の歯幅を広く設定するだけで従動部材４２の軸方向の移動に対応でき、構造を簡素化できる。 (9) Since the driven member 42 moves in the axial direction when changing the valve timing of the intake valve, the chain line moves when the cam chain system using the power receiving portion of the driven member 42 as a sprocket is adopted. In addition, since the chain tensioner and the like are moved along with the movement of the chain line, the structure becomes complicated. On the other hand, when the power receiving portion of the driven member 42 is a gear (intake side cam driven gear 33) and the final power transmission of the driven member 42 is performed by gear drive, the teeth of the intake side cam driven gear 33 are provided. It is possible to cope with the axial movement of the driven member 42 simply by setting the width wide, and the structure can be simplified.

（１０）吸気側カムシャフト３４の一端部に筒状部材４６がボルト５３にて結合され、この筒状部材４６の座面受部４８と従動部材４２との間に付勢部材４５が介在されたので、ヘッドカバー２４を取り外し、筒状部材４６を取り外すだけで付勢部材４５を交換できる。この結果、イニシャル荷重の異なる付勢部材４５に交換することで、吸気バルブのバルブタイミング切替特性を容易に変更できる。 (10) A cylindrical member 46 is coupled to one end of the intake side camshaft 34 by a bolt 53, and a biasing member 45 is interposed between the seat surface receiving portion 48 of the cylindrical member 46 and the driven member 42. Therefore, the urging member 45 can be replaced simply by removing the head cover 24 and removing the tubular member 46. As a result, the valve timing switching characteristic of the intake valve can be easily changed by replacing the biasing member 45 with a different initial load.

（１１）筒状部材４６の摺動面部４７と座面受部４８との間に段部５４が形成され、この段部５４により従動部材４２の摺動範囲が規定されるので、ウェイトボール４４が、従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２との間でガタツクことを防止できる。更に、ウェイトボール４４がガイド溝５１やガイド溝５２から飛び出して、従動部材４２とガイドプレート４３との間に噛み込まれることを防止でき、これにより、カムシャフト位相可変装置４０のロック（動作不良）を回避できる。 (11) A step portion 54 is formed between the sliding surface portion 47 and the seat surface receiving portion 48 of the cylindrical member 46, and the sliding range of the driven member 42 is defined by the step portion 54. However, rattling between the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43 can be prevented. Further, it is possible to prevent the weight ball 44 from jumping out of the guide groove 51 or the guide groove 52 and being caught between the driven member 42 and the guide plate 43, thereby locking the camshaft phase varying device 40 (malfunction). ) Can be avoided.

尚、付勢部材４５の付勢力は従動部材４２に付与されず、ガイドプレート４３に付与されてもよく、これらの両者に付与されてもよい。また、従動部材４２のガイド溝５１に、溝深さの勾配α及びβを設け、ガイドプレート４２のガイド溝５２を角度θだけ傾斜して形成してもよい。または、ガイド溝５１とガイド溝５２のいずれか一方に、溝深さの勾配α及びβを設け、且つ角度θの傾斜を設けてもよい。更に、従動部材４２が形成された動力受部はギアに限らず、ベルトプーリまたはスプロケットであってもよい。 The urging force of the urging member 45 may not be applied to the driven member 42 but may be applied to the guide plate 43 or may be applied to both of them. Alternatively, the guide groove 51 of the driven member 42 may be provided with groove depth gradients α and β, and the guide groove 52 of the guide plate 42 may be formed to be inclined by an angle θ. Alternatively, groove depth gradients α and β may be provided in either one of the guide groove 51 and the guide groove 52, and an inclination of an angle θ may be provided. Furthermore, the power receiving portion in which the driven member 42 is formed is not limited to a gear, and may be a belt pulley or a sprocket.

［Ｂ］第２の実施の形態（図９〜図１１）
図９は、本発明に係るエンジンの動弁装置における第２の実施の形態のカムシャフト位相可変装置において、付勢部材のイニシャル荷重変更前の状態を示す断面図である。図１０は、図９のカムシャフト位相可変装置において、付勢部材のイニシャル荷重変更後の状態を示す断面図である。この第２の実施の形態において、前記第１の実施の形態と同様な部分には同一の符号を付して説明を簡略化し、または省略する。 [B] Second embodiment (FIGS. 9 to 11)
FIG. 9 is a cross-sectional view showing the state before the initial load of the urging member is changed in the camshaft phase varying device according to the second embodiment of the valve gear of the engine according to the present invention. 10 is a cross-sectional view showing a state after changing the initial load of the biasing member in the camshaft phase varying device of FIG. In the second embodiment, the same reference numerals are given to the same parts as those in the first embodiment, and the description will be simplified or omitted.

本実施の形態における動弁装置６０のカムシャフト位相可変装置６１が前記実施の形態における動弁装置２０のカムシャフト位相可変装置４０と異なる点は、付勢部材４５のイニシャル荷重が、当該付勢部材４５を交換することなく無段階に変更可能に構成された点である。 The camshaft phase varying device 61 of the valve gear 60 in the present embodiment is different from the camshaft phase varying device 40 of the valve gear 20 in the above embodiment in that the initial load of the biasing member 45 is the biasing force. This is a point that can be changed steplessly without replacing the member 45.

つまり、本実施の形態におけるカムシャフト位相可変装置６１における筒状部材６２は、摺動面部４７を備える摺動面部側部材６３と、座面受部４８を備える座面受部側部材６４とを有してなる。摺動面部側部材６３がボルト５３により吸気側カムシャフト３４の一端面に結合されると共に、座面受部側部材６４が摺動面部側部材６３に対して軸方向に相対移動可能に設けられる。 That is, the cylindrical member 62 in the camshaft phase varying device 61 in the present embodiment includes the sliding surface portion side member 63 provided with the sliding surface portion 47 and the seat surface receiving portion side member 64 provided with the seat surface receiving portion 48. Have. The sliding surface portion side member 63 is coupled to one end surface of the intake side camshaft 34 by a bolt 53, and the seat surface receiving portion side member 64 is provided so as to be relatively movable in the axial direction with respect to the sliding surface portion side member 63. .

また、カムシャフト位相可変装置６１は、従動部材４２、ガイドプレート４３、ウェイトボール４４、付勢部材４５及び上記筒状部材６２の他、スライドギア６５、スライドギアガイド６６、アイドルギア６７、ドライブギア６８及び電動アクチュエータ６９を有して構成される。 The camshaft phase varying device 61 includes a driven gear 42, a guide plate 43, a weight ball 44, a biasing member 45 and the cylindrical member 62, a slide gear 65, a slide gear guide 66, an idle gear 67, a drive gear. 68 and an electric actuator 69.

スライドギア６５は、座面受部側部材６４とベアリング７０を介して連結され、この座面受部側部材６４に対して、軸方向に一体で相対回転自在に構成される。また、スライドギアガイド６６は、シリンダヘッド２３に固定されると共に、スライドギア６５の送りねじ７１に螺合するねじ部７２を備える。このスライドギアガイド６６は、スライドギア６５の回転により当該スライドギア６５を軸方向に移動させる。 The slide gear 65 is connected to the seat surface receiving portion side member 64 via a bearing 70, and is configured to be rotatable relative to the seat surface receiving portion side member 64 integrally in the axial direction. The slide gear guide 66 includes a screw portion 72 that is fixed to the cylinder head 23 and is screwed to the feed screw 71 of the slide gear 65. The slide gear guide 66 moves the slide gear 65 in the axial direction by the rotation of the slide gear 65.

ドライブギア６８は、電動アクチュエータ６９のシャフトに結合され、アイドルギア６７の大径ギアに噛み合う。このアイドルギア６７の小径ギアは、スライドギア６５のドリブンギア７３に噛み合う。これらのドライブギア６８、アイドルギア６７及びドリブンギア７３が、電動アクチュエータ６９の回転を減速する減速装置として機能する。電動アクチュエータ６９は、この減速装置を経てスライドギア６５を回転駆動し、当該スライドギア６５及び座面受部側部材６４を軸方向に移動させる。この座面受部側部材６４の軸方向位置は、スライドギア６５の背面に当接したギャップセンサ７４により検出される。 The drive gear 68 is coupled to the shaft of the electric actuator 69 and meshes with the large-diameter gear of the idle gear 67. The small diameter gear of the idle gear 67 meshes with the driven gear 73 of the slide gear 65. These drive gear 68, idle gear 67 and driven gear 73 function as a speed reducer that decelerates the rotation of the electric actuator 69. The electric actuator 69 rotationally drives the slide gear 65 through this reduction device, and moves the slide gear 65 and the seat surface receiving portion side member 64 in the axial direction. The axial position of the seat surface receiving portion side member 64 is detected by a gap sensor 74 that is in contact with the back surface of the slide gear 65.

従って、座面受部側部材６４が摺動面部側部材６３に最も接近した図９に示す位置で電動アクチュエータ６９を所定方向に回転させると、ギア６８、６７及び７３の作用でスライドギア６５が回転し、このスライドギア６５は、図１０に示すように、スライドギア６５の送りねじ７１とスライドギアガイド６６のねじ部７２とによって軸方向外方へ移動し、座面受部側部材６４を摺動面部側部材６３から離反する方向に移動する。これにより、付勢部材４５の座面５５が従動部材４２から離反し、付勢部材４５のイニシャル荷重が減少する。 Therefore, when the electric actuator 69 is rotated in a predetermined direction at the position shown in FIG. 9 where the seat surface receiving portion side member 64 is closest to the sliding surface portion side member 63, the slide gear 65 is moved by the action of the gears 68, 67 and 73. As shown in FIG. 10, the slide gear 65 moves outward in the axial direction by the feed screw 71 of the slide gear 65 and the screw portion 72 of the slide gear guide 66, so that the seat surface receiving portion side member 64 is moved. It moves in a direction away from the sliding surface portion side member 63. Thereby, the seating surface 55 of the urging member 45 is separated from the driven member 42, and the initial load of the urging member 45 is reduced.

このように付勢部材４５のイニシャル荷重が減少すると、ウェイトボール４４は、従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２内を径方向外方へ移動し易くなり、吸気側カムシャフト３４（つまり吸気カム３２）の進角側への回転方向位相の変化は、第１実施形態におけるエンジン１０の高回転でない回転域でも発生する。従って、吸気バルブのバルブタイミングも、第１実施形態におけるエンジン１０の高回転でない回転域で、バルブオーバーラップの小さな低速用バルブタイミングから、バルブオーバーラップの大きな高速用バルブタイミングへと切り替わり、バルブタイミング切替のエンジン回転数が低く設定される。 When the initial load of the urging member 45 is reduced in this way, the weight ball 44 is likely to move radially outward in the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43, and the intake camshaft The change in the rotational direction phase of 34 (that is, the intake cam 32) toward the advance side also occurs in a rotational region where the engine 10 in the first embodiment is not at a high rotational speed. Accordingly, the valve timing of the intake valve is also switched from the low-speed valve timing with a small valve overlap to the high-speed valve timing with a large valve overlap in the rotation range of the engine 10 in the first embodiment that is not high. The engine speed for switching is set low.

例えば、筒状部材６２の座面受部側部材６４が摺動面部側部材６３に最も接近して、付勢部材４５のイニシャル荷重が最も高い図９に示す状態では、図１１の実線Ｎに示すように、エンジン回転数が例えば１２０００ｒｐｍ程度を越えなければ吸気側カムシャフト３４（吸気カム３２）の回転方向の位相が進角側へ変化せず、吸気バルブのバルブタイミングが、バルブオーバーラップの大きな高速用バルブタイミングへと切り替わらない。 For example, in the state shown in FIG. 9 in which the seat surface receiving portion side member 64 of the cylindrical member 62 is closest to the sliding surface portion side member 63 and the initial load of the biasing member 45 is the highest, the solid line N in FIG. As shown, if the engine speed does not exceed, for example, about 12000 rpm, the phase in the rotational direction of the intake camshaft 34 (intake cam 32) does not change to the advance side, and the valve timing of the intake valve is the valve overlap. Does not switch to large high-speed valve timing.

これに対し、筒状部材６２の座面受部側部材６４が摺動面部側部材６３から最も離反して、付勢部材４５のイニシャル荷重が最も低い図１０に示す状態では、図１１の実線Ｍに示すように、エンジン回転数が例えば６０００ｒｐｍ程度の段階で、吸気側カムシャフト３４（吸気カム３２）の回転方向の位相が進角側へ変化する。これにより、吸気バルブのバルブタイミングは、バルブオーバーラップの大きな高速用バルブタイミングに切り替わる。付勢部材４５のイニシャル荷重を任意に変更することで、バルブオーバーラップの大きな高速用バルブタイミングへ切り替えるバルブタイミング切替回転数を無段階に変更することが可能となる。 On the other hand, in the state shown in FIG. 10 in which the seat surface receiving portion side member 64 of the cylindrical member 62 is farthest from the sliding surface portion side member 63 and the initial load of the biasing member 45 is the lowest, the solid line in FIG. As indicated by M, the phase in the rotational direction of the intake camshaft 34 (intake cam 32) changes to the advance side when the engine speed is about 6000 rpm, for example. As a result, the valve timing of the intake valve is switched to a high-speed valve timing with a large valve overlap. By arbitrarily changing the initial load of the urging member 45, it is possible to change the valve timing switching rotational speed for switching to a high-speed valve timing with a large valve overlap steplessly.

以上のように構成されたことから、本実施の形態によれば、前記実施の形態の効果（１）〜（１１）と同様な効果を奏するほか、次の効果（１２）を奏する。 With the configuration as described above, according to the present embodiment, in addition to the same effects as the effects (1) to (11) of the above embodiment, the following effect (12) is achieved.

（１２）電動アクチュエータ６９を駆動して付勢部材４５のイニシャル荷重を任意に変更することで、吸気バルブをバルブオーバーラップの大きな高速用バルブタイミングへ切り替えるバルブタイミング切替回転数を無段階に変更可能に構成している。このことから、車両走行中に、エンジン回転数などの運転状況や路面状況に応じて付勢部材４５のイニシャル荷重を変更することで、吸気バルブのバルブタイミング切替特性を、その時点の運転状況などに応じて最適に設定することができる。 (12) By driving the electric actuator 69 and arbitrarily changing the initial load of the biasing member 45, the valve timing switching speed for switching the intake valve to the high-speed valve timing with a large valve overlap can be changed steplessly. It is configured. From this, while the vehicle is running, by changing the initial load of the biasing member 45 according to the driving situation such as the engine speed and the road surface situation, the valve timing switching characteristics of the intake valve, the driving situation at that time, etc. It can be set optimally according to.

［Ｃ］第３の実施の形態（図１２〜図１５）
図１２は、本発明に係るエンジンの動弁装置における第３の実施の形態のカムシャフト位相可変装置を示す断面図である。この第３の実施の形態において、前記第１の実施の形態と同様な部分には同一の符号を付して説明を簡略化し、または省略する。 [C] Third embodiment (FIGS. 12 to 15)
FIG. 12 is a cross-sectional view showing a camshaft phase varying device according to a third embodiment of the valve gear for an engine according to the present invention. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be simplified or omitted.

本実施の形態における動弁装置８０のカムシャフト位相可変装置８１が前記第１の実施の形態における動弁装置２０のカムシャフト位相可変装置４０と異なる点は、付勢部材４５に代えて、従動部材４２とガイドプレート４３とが周方向に沿って反発する方向の付勢力を付与する付勢部材８２を用い、また、ガイドプレート４３のガイド溝５２の溝深さが一定に形成され、更に、筒状部材４６に代えて筒状部材８３を用いた点である。 The camshaft phase varying device 81 of the valve operating device 80 in the present embodiment is different from the camshaft phase varying device 40 of the valve operating device 20 in the first embodiment in that the follower is replaced with the urging member 45. Using a biasing member 82 that applies a biasing force in a direction in which the member 42 and the guide plate 43 repel each other in the circumferential direction, the groove depth of the guide groove 52 of the guide plate 43 is formed constant, The cylindrical member 83 is used instead of the cylindrical member 46.

つまり、筒状部材８３は、吸気側カムシャフト３４の一端にボルト５３を用いて結合され、内部に付勢部材８２としての捩りコイルスプリング（図１３）を収容すると共に、この付勢部材８２の一端８２Ａを係止する。付勢部材８２の他端８２Ｂは従動部材４２に係止される。 That is, the cylindrical member 83 is coupled to one end of the intake side camshaft 34 using the bolt 53 and accommodates a torsion coil spring (FIG. 13) as the urging member 82 therein. One end 82A is locked. The other end 82 B of the urging member 82 is locked to the driven member 42.

図１４及び図１５に示す従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２とは、共に溝深さが一定に形成される。また、これらのガイド溝５１と５２のうち少なくとも一方、本実施の形態ではガイド溝５１が、従動部材４２の径方向に対して周方向一方側に角度θだけ傾斜して形成され、ガイド溝５２がガイドプレート４３の径方向に形成されている。そして、これらのガイド溝５１及び５２間にウェイトボール４４が保持される。 Both the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43 shown in FIGS. 14 and 15 are formed to have a constant groove depth. In addition, at least one of the guide grooves 51 and 52, in this embodiment, the guide groove 51 is formed to be inclined at an angle θ on one side in the circumferential direction with respect to the radial direction of the driven member 42. Is formed in the radial direction of the guide plate 43. A weight ball 44 is held between the guide grooves 51 and 52.

付勢部材８２は、その一端８２Ａが筒状部材８３に、他端８２Ｂが従動部材４２にそれぞれ係止されているので、従動部材４２とガイドプレート４３の少なくとも一方、本実施の形態では従動部材４２及びガイドプレート４３に、従動部材４２と、筒状部材８３及び吸気側カムシャフト３４を介してのガイドプレート４３とが周方向に沿って反発する方向の付勢力を付与する。つまり、付勢部材８２は、従動部材４２に対しては図１４の矢印Ｐ方向の付勢力を、ガイドプレート４３に対しては上記矢印Ｐ方向と反対の矢印Ｑ（図１４、図１５）方向の付勢力をそれぞれ付与する。 The urging member 82 has one end 82A engaged with the cylindrical member 83 and the other end 82B engaged with the driven member 42. Therefore, at least one of the driven member 42 and the guide plate 43, in this embodiment, the driven member A biasing force in a direction in which the driven member 42 and the guide plate 43 through the cylindrical member 83 and the intake side camshaft 34 are repelled in the circumferential direction is applied to the guide plate 43 and the guide plate 43. That is, the urging member 82 exerts an urging force in the direction of arrow P in FIG. 14 on the driven member 42, and an arrow Q (FIG. 14, FIG. 15) direction opposite to the arrow P direction on the guide plate 43. Each of the energizing power is given.

また、この付勢部材８２の付勢力は、従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２とを、それぞれの径方向内側端で重なる初期位置に設定し、ウェイトボール４４をガイド溝５１及び５２内で上記初期位置に位置させる方向に作用する。上記初期位置は、従動部材４２の周壁部４９に形成された位置決め突起８４と、ガイドプレート４３の外周面に設けられた位置決めピン８５とが当接することにより得られる。 Further, the urging force of the urging member 82 is set such that the guide groove 51 of the driven member 42 and the guide groove 52 of the guide plate 43 overlap each other at the radially inner end, and the weight ball 44 is guided to the guide groove. It acts in the direction to be positioned at the initial position within 51 and 52. The initial position is obtained when the positioning projections 84 formed on the peripheral wall portion 49 of the driven member 42 and the positioning pins 85 provided on the outer peripheral surface of the guide plate 43 abut.

従って、エンジン１０が高回転域に至り、吸気側カムシャフト３４が高回転してウェイトボール４４に作用する遠心力が大きくなると、このウェイトボール４４が、従動部材４２のガイド溝５１とガイドプレート４３のガイド溝５２の径方向外方へ移動する。このとき、ガイドプレート４３は、ガイド溝５１及び５２のガイド溝形状によって、吸気側カムシャフト３４及び筒状部材８３と一体的に、付勢部材８２の付勢力（矢印Ｑ方向）に抗し、従動部材４２に対して図１５の矢印Ｒ方向（図１４の矢印Ｐ方向）に相対回転する。その結果、ガイドプレート４３は、従動部材４２に対して、当該従動部材４２におけるガイド溝５１の傾斜方向に角度θだけ相対回転して、吸気側カムシャフト３４のクランクシャフト２１に対する回転方向の位相が変化する。このときの吸気側カムシャフト３４の位相の変化は、この吸気側カムシャフト３４の回転方向の進角側である。この吸気側カムシャフト３４（吸気カム３２）のクランクシャフト２１に対する位相の変化により、吸気バルブと排気バルブは、バルブオーバーラップの大きな高速用バルブタイミングとなる。 Accordingly, when the engine 10 reaches a high rotation range and the intake camshaft 34 rotates at a high speed and the centrifugal force acting on the weight ball 44 increases, the weight ball 44 is guided by the guide groove 51 and the guide plate 43 of the driven member 42. The guide groove 52 moves outward in the radial direction. At this time, the guide plate 43 resists the urging force (in the direction of the arrow Q) of the urging member 82 integrally with the intake side camshaft 34 and the tubular member 83 due to the guide groove shapes of the guide grooves 51 and 52. It rotates relative to the driven member 42 in the direction of arrow R in FIG. 15 (direction of arrow P in FIG. 14). As a result, the guide plate 43 rotates relative to the driven member 42 by an angle θ in the inclination direction of the guide groove 51 in the driven member 42, so that the rotational direction phase of the intake camshaft 34 relative to the crankshaft 21 is increased. Change. The change in the phase of the intake camshaft 34 at this time is the advance side in the rotational direction of the intake camshaft 34. Due to the change in phase of the intake camshaft 34 (intake cam 32) with respect to the crankshaft 21, the intake valve and the exhaust valve have a high valve timing with a large valve overlap.

エンジン１０の回転数が低下して、吸気側カムシャフト３４が低回転になり、ウェイトボール４４に作用する遠心力が小さくなり、付勢部材８２の付勢力が勝ると、この付勢力が筒状部材８３、吸気側カムシャフト３４及びガイドプレート４３を矢印Ｑ方向に回転させ、ウェイトボール４４をガイド溝５１及び５２の径方向内側端の方向へ移動させ、やがて従動部材４２とガイドプレート４３との相対位置が初期位置に復帰する。この結果、吸気バルブと排気バルブは、バルブオーバーラップの小さな低速用バルブタイミングとなる。 When the rotational speed of the engine 10 is reduced, the intake camshaft 34 is rotated at a low speed, the centrifugal force acting on the weight ball 44 is reduced, and the urging force of the urging member 82 is won, the urging force is cylindrical. The member 83, the intake side camshaft 34 and the guide plate 43 are rotated in the direction of the arrow Q, and the weight ball 44 is moved toward the radially inner end of the guide grooves 51 and 52. Eventually, the driven member 42 and the guide plate 43 The relative position returns to the initial position. As a result, the intake valve and the exhaust valve have a low-speed valve timing with a small valve overlap.

以上のように構成されたことから、本実施の形態の動弁装置８０においても、前記第１の実施の形態の動弁装置２０の効果（１）〜（１１）と同様な効果を奏する（効果（６）〜（８）は除く）。 With the configuration as described above, the valve operating device 80 of the present embodiment also has the same effects as the effects (1) to (11) of the valve operating device 20 of the first embodiment ( Effects (6) to (8) are excluded).

以上、本発明を上記実施の形態に基づいて説明したが、本発明はこれに限定されるものではない。 As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this.

例えば、上述の第１〜第３の実施の形態では、吸気側カムシャフト３４にカムシャフト位相可変装置４０、６１、８１が設置されて、エンジン高回転時に吸気側カムシャフト３４の回転方向の位相をクランクシャフト２１に対し進角側に変化させ、吸気バルブと排気バルブとのバルブタイミングを、バルブオーバーラップの大きな高速用バルブタイミングに変更するものを述べた。これに対し、排気側カムシャフト３７に、カムシャフト位相可変装置４０と同様なカムシャフト位相可変装置を設置し、エンジン高回転時に排気側カムシャフト３７の回転方向の位相をクランクシャフト２１に対し遅角側に変化させて、吸気バルブと排気バルブのバルブタイミングを、バルブオーバーラップの大きな高速用バルブタイミングに変更するように構成してもよい。また、これらの吸気側カムシャフト３４と排気側カムシャフト３７の両者にカムシャフト位相可変装置を設置して、エンジン高回転時に吸気バルブと排気バルブのバルブタイミングを、バルブオーバーラップの大きな高速用バルブタイミングに変更するように構成してもよい。 For example, in the above-described first to third embodiments, the camshaft phase varying devices 40, 61, 81 are installed on the intake side camshaft 34, and the rotational direction phase of the intake side camshaft 34 during high engine rotation. Has been described in which the valve timing of the intake valve and the exhaust valve is changed to a high-speed valve timing with a large valve overlap. On the other hand, a camshaft phase varying device similar to the camshaft phase varying device 40 is installed on the exhaust side camshaft 37 so that the phase in the rotational direction of the exhaust side camshaft 37 is delayed with respect to the crankshaft 21 at the time of high engine rotation. The valve timing of the intake valve and the exhaust valve may be changed to a high-speed valve timing with a large valve overlap by changing to the corner side. In addition, camshaft phase variable devices are installed on both the intake side camshaft 34 and the exhaust side camshaft 37 so that the valve timings of the intake valve and the exhaust valve can be set at a high engine speed when the engine speed is high. You may comprise so that it may change to a timing.

本発明に係るエンジンの動弁装置における第１の実施の形態が適用されたエンジンを搭載する自動二輪車の右側面図。1 is a right side view of a motorcycle equipped with an engine to which a first embodiment of an engine valve gear according to the present invention is applied. 図１のエンジンの上部を示す部分右側面図。The partial right view which shows the upper part of the engine of FIG. 図２のIII−III線に沿う断面図。Sectional drawing which follows the III-III line | wire of FIG. 図３のカムシャフト位相可変装置を示す分解斜視図。The disassembled perspective view which shows the camshaft phase variable apparatus of FIG. （Ａ）は図３の従動部材を示す正面図、（Ｂ）は図５（Ａ）のVＢ部の部分拡大図。(A) is a front view which shows the driven member of FIG. 3, (B) is the elements on larger scale of the VB part of FIG. 5 (A). （Ａ）は図３のガイドプレートを示す正面図、（Ｂ）は図６（Ａ）のVI−VI線に沿う断面図。(A) is a front view which shows the guide plate of FIG. 3, (B) is sectional drawing which follows the VI-VI line of FIG. 6 (A). 図３のカムシャフト位相可変装置におけるエンジン低回転時のウェイトボールの位置を示す動作説明図。FIG. 4 is an operation explanatory view showing the position of the weight ball at the time of engine low rotation in the camshaft phase varying device of FIG. 3. 図３のカムシャフト位相可変装置におけるエンジン高回転時のウェイトボールの位置を示す動作説明図。FIG. 4 is an operation explanatory view showing the position of the weight ball when the engine rotates at a high speed in the camshaft phase varying device of FIG. 3. 本発明に係るエンジンの動弁装置における第２の実施の形態のカムシャフト位相可変装置において、付勢部材のイニシャル荷重変更前の状態を示す断面図。Sectional drawing which shows the state before the initial load change of an urging | biasing member in the camshaft phase variable apparatus of 2nd Embodiment in the valve operating apparatus of the engine which concerns on this invention. 図９のカムシャフト位相可変装置において、付勢部材のイニシャル荷重変更後の状態を示す断面図。FIG. 10 is a cross-sectional view showing a state after changing an initial load of a biasing member in the camshaft phase varying device of FIG. 9. 図９及び図１０のカムシャフト位相可変装置におけるエンジン回転数と吸気カムの回転方向の位相との関係を示すグラフ。The graph which shows the relationship between the engine speed in the camshaft phase variable apparatus of FIG.9 and FIG.10, and the phase of the rotation direction of an intake cam. 本発明に係るエンジンの動弁装置における第３の実施の形態のカムシャフト位相可変装置を示す断面図。Sectional drawing which shows the camshaft phase variable apparatus of 3rd Embodiment in the valve operating apparatus of the engine which concerns on this invention. 図１２の捩りコイルスプリングを示す斜視図。The perspective view which shows the torsion coil spring of FIG. 図１２の従動部材を示す正面図。The front view which shows the driven member of FIG. 図１２のガイドプレートを示す正面図。The front view which shows the guide plate of FIG.

Explanation of symbols

１０エンジン
２０動弁装置
２１クランクシャフト
２３シリンダヘッド
３２吸気カム
３４吸気側カムシャフト
３７排気側カムシャフト
４０カムシャフト位相可変装置
４２従動部材
４３ガイドプレート
４４ウェイトボール
４５付勢部材
４６筒状部材
４７摺動面部
４８座面受部
４９周壁部
５０内壁面
５１、５２ガイド溝
５４段部
６０動弁装置
６１カムシャフト位相可変装置
６２筒状部材
６３摺動面部側部材
６４座面受部側部材
６５スライドギア
６６スライドギアガイド
６７アイドルギア(減速装置)
６８ドライブギア(減速装置)
６９電導アクチュエータ
７３ドリブンギア(減速装置)
８０動弁装置
８１カムシャフト位相可変装置
８２付勢部材
８３筒状部材
θ 角度
α、β 勾配 DESCRIPTION OF SYMBOLS 10 Engine 20 Valve operating apparatus 21 Crankshaft 23 Cylinder head 32 Intake cam 34 Intake side camshaft 37 Exhaust side camshaft 40 Camshaft phase variable apparatus 42 Follower member 43 Guide plate 44 Weight ball 45 Energizing member 46 Cylindrical member 47 Sliding Moving surface portion 48 Seat surface receiving portion 49 Peripheral wall portion 50 Inner wall surface 51, 52 Guide groove 54 Step portion 60 Valve operating device 61 Camshaft phase varying device 62 Cylindrical member 63 Sliding surface portion side member 64 Seat surface receiving portion side member 65 Slide Gear 66 Slide gear guide 67 Idle gear (reduction gear)
68 Drive gear (reduction gear)
69 Conductive actuator 73 Driven gear (reduction gear)
80 Valve operating device 81 Camshaft phase varying device 82 Biasing member 83 Cylindrical member θ Angle α, β Gradient

Claims

A crankshaft,
A camshaft that is driven by the crankshaft and has a cam that drives the valve;
A valve operating device for an engine having a camshaft phase varying device provided on the camshaft and changing a phase of the camshaft in a rotational direction with respect to the crankshaft.
The camshaft phase varying device is
A driven member driven by the crankshaft and having the same rotational direction phase with respect to the crankshaft;
A guide plate that rotates integrally with the camshaft and is rotatable relative to the driven member;
Weight balls that are held between radial guide grooves respectively formed on mutually facing surfaces of the driven member and the guide plate, and transmit the rotation of the driven member to the guide plate;
A biasing member that applies a biasing force that biases the driven member and the guide plate in a direction in which the driven member and the guide plate approach each other, on at least one of the driven member and the guide plate;
The follower member and the guide groove of the guide plate are formed so that the bottoms of the guide grooves approach each other as they go radially outward, and at least one of the guide grooves is inclined to one side in the circumferential direction with respect to the radial direction. Formed,
As the centrifugal force acts on the weight ball and the weight ball moves radially outward in the guide groove, the driven member moves in the axial direction against the urging force of the urging member. A valve operating apparatus for an engine, wherein the guide plate is configured to rotate relative to the driven member by a predetermined amount.

In the driven member, a power receiving portion is formed on the outer peripheral surface, a peripheral wall portion is formed on the inner peripheral side of the power receiving portion, and the outer peripheral surface of the guide plate can be slidably contacted with the wall surface of the peripheral wall portion. The valve operating apparatus for an engine according to claim 1, wherein the valve operating apparatus is configured as follows.

3. The guide groove of the driven member is formed to have a constant groove depth, and a gradient is provided in the guide groove of the guide plate such that the groove depth decreases toward the outer side in the radial direction. The valve operating device for an engine according to 1.

4. The engine according to claim 3, wherein the guide groove of the guide plate is formed in a radial direction, and the guide groove of the driven member is formed to be inclined to one side in the circumferential direction with respect to the radial direction. Valve gear.

4. The valve gear for an engine according to claim 3, wherein the guide groove of the guide plate is configured such that a gradient of a groove bottom portion becomes steeper toward a radially outward direction.

The engine valve operating device according to claim 2, wherein the power receiving portion of the driven member is a gear.

The camshaft phase varying device further includes a cylindrical member having a sliding surface portion and a seating surface receiving portion, and the sliding surface portion is formed on the outer peripheral surface of the cylindrical member to slide the driven member. The seating surface receiving portion is formed at an end portion on the opposite side to the sliding surface portion in the cylindrical member, and the biasing member is interposed between the driven member and the driven member. The valve operating apparatus for an engine according to claim 1.

8. The valve gear for an engine according to claim 7, wherein a stepped portion on which the driven member can abut between the sliding surface portion and the seat surface receiving portion is formed on the cylindrical member.

The cylindrical member has a sliding surface portion side member provided with the sliding surface portion and a seat surface receiving portion side member provided with the seat surface receiving portion, and these both members move relative to each other in the axial direction. Configured and possible
In addition, the camshaft phase varying device further includes a slider gear that is integral and axially rotatable relative to the seat surface receiving portion side member;
A slider gear guide threadedly engaged with the feed screw of the slider gear and moving the slider gear in the axial direction by rotation of the slider gear;
The valve operating apparatus for an engine according to claim 7, further comprising an actuator that rotationally drives the slider gear via a speed reducer.

A crankshaft,
A camshaft that is driven by the crankshaft and has a cam that drives the valve;
A valve operating device for an engine having a camshaft phase varying device that is provided on the camshaft and changes a phase of the camshaft in a rotation direction with respect to the crankshaft.
The camshaft phase varying device is
A driven member driven by the crankshaft and having the same rotational direction phase with respect to the crankshaft;
A guide plate that rotates integrally with the camshaft and is rotatable relative to the driven member;
Weight balls that are held between radial guide grooves respectively formed on mutually facing surfaces of the driven member and the guide plate, and transmit the rotation of the driven member to the guide plate;
A biasing member that applies a biasing force in a direction in which the driven member and the guide plate are repelled in a circumferential direction on at least one of the driven member and the guide plate;
At least one of the follower member and the guide groove of the guide plate is formed to be inclined in the circumferential direction one side with respect to the radial direction,
The urging force of the urging member positions the weight ball at the radially inner end in the guide groove,
Centrifugal force acts on the weight ball, and the weight ball moves radially outward in the guide groove against the urging force of the urging member, so that the guide plate moves relative to the driven member. And a valve operating device for an engine, wherein the valve operating device is configured to relatively rotate by a predetermined amount.