JPS6021442Y2 - Flat tappet for internal combustion engine - Google Patents

Description

【考案の詳細な説明】 本考案は、内燃機関の吸、排気弁を開閉作動せしめる動
弁装置における筒状の平タペットに関する。[Detailed Description of the Invention] The present invention relates to a cylindrical flat tappet in a valve train that opens and closes intake and exhaust valves of an internal combustion engine.

この種、筒状平タペットには、シリンダやシリンダヘッ
ドの熱による伸びと、動弁装置の熱による伸びとの差を
考慮して、いわゆる弁クリアランスを設けている。This type of cylindrical flat tappet is provided with a so-called valve clearance in consideration of the difference between the heat-induced elongation of the cylinder or cylinder head and the heat-induced elongation of the valve train.

かかる弁クリアランスは、騒音の原因となったり、弁の
躍りの一因になったり、更には、摩耗の原因にもなり、
機関性能に好ましくない。Such valve clearance causes noise, contributes to valve movement, and even causes wear.
Unfavorable for engine performance.

そのため、吸、排気弁の作動中、常にかかる弁クリアラ
ンスを零に保ち、かつ、熱による前記伸びの変化も吸収
できる機構が各種提案されている。Therefore, various mechanisms have been proposed that can always maintain the valve clearance at zero during operation of the intake and exhaust valves, and can also absorb changes in elongation due to heat.

例えば、ハイドロタペットや、該ハイドロタペット機構
中のコイルスプリングのみで構成したスプリング内蔵タ
ペット（例えば、実開昭５５−７３５０４号公報）が提
案されている。For example, a hydrotappet and a spring-incorporated tappet (for example, Japanese Utility Model Application Publication No. 55-73504), which is constructed of only a coil spring in the hydrotappet mechanism, have been proposed.

かかる提案されたタペットの場合、前者では、油圧室の
オイルの量と該油圧室のオイルのスピルする量とのバラ
ンス得がたく、後者では、コイルスプリングによる複雑
な振動の発生は否めない。In the case of such proposed tappets, in the former case, it is difficult to achieve a balance between the amount of oil in the hydraulic chamber and the amount of spilled oil in the hydraulic chamber, and in the latter case, it is undeniable that complex vibrations are generated due to the coil spring.

一方、機関が高速化するにしたがい、タペットなどに事
故が多発する。On the other hand, as engines become faster, accidents involving tappets and other parts occur more frequently.

例えば、タペットカムが一時的に離れたり、接触したり
すると、その衝撃で、ピッチング（点食）が大巾に増大
する。For example, when the tappet cams temporarily separate or come into contact, the impact greatly increases pitching (pitting).

しかるに、前記提案されたタペットでは、機構が複雑な
だけに、例えば、ピッチングの問題にしても、完全に回
避できず、しかも、弁バネの固有振動を下げる目的でタ
ペット軽量化を図っているが、かかる軽量化にもそぐわ
ない。However, since the proposed tappet has a complicated mechanism, it is impossible to completely avoid the problem of pitching, for example.Moreover, although efforts have been made to reduce the weight of the tappet in order to reduce the natural vibration of the valve spring, , it is not suitable for such weight reduction.

そこで本考案は、これらの欠点を一挙に除くため案出さ
れたもので、第１図は動弁装置の全体図、第２図は本考
案の実施例の要部図で、１は吸気または排気弁、２は軸
３に枢着された弁腕、４は弁押棒、５は筒状タペット本
体、６はカム軸、７はタペット本体５の底部上に横設さ
れた板バネであるが、該板バネ７は打抜きにより中央部
を凹状に彎曲させて弁押棒４の球状端部が当接するよう
にしており、該横設は板バネ７周端をタペット本体５の
内に突出した肩部９に載置して構成している。Therefore, the present invention was devised to eliminate these drawbacks all at once. Figure 1 is an overall view of the valve train, Figure 2 is a diagram of the main parts of an embodiment of the present invention, and 1 is the intake or In the exhaust valve, 2 is a valve arm pivotally connected to a shaft 3, 4 is a valve push rod, 5 is a cylindrical tappet body, 6 is a camshaft, and 7 is a leaf spring installed horizontally on the bottom of the tappet body 5. The leaf spring 7 is punched and curved in a concave shape at the center so that the spherical end of the valve pusher rod 4 comes into contact with it, and the horizontal end of the leaf spring 7 is bent into a shoulder projecting into the tappet body 5. It is configured by being placed in section 9.

板バネ７の凹状による板バネ突出部とタペット本体５の
底部とは機関が無負荷時ないし軽負荷時には、スキマ七
を有しているが、高負荷時には板バネ７がたわみを生じ
、このスキマＳが零になるようにしている。When the engine is under no load or under a light load, there is a gap 7 between the protruding portion of the leaf spring 7 due to the concave shape and the bottom of the tappet body 5, but when the load is high, the leaf spring 7 deflects and this gap is removed. It is made so that S becomes zero.

かかる動弁装置において、機関が無負荷または軽負荷時
には、カム軸６のカムノーズ６′の動キの弁１に伝える
が、その駆動はタペット本体５→肩部９→板バネ７→弁
押棒４→弁腕２→弁１の順序に伝え、これら中間に板バ
ネ７が介在した状態で動きが伝えられる。In such a valve train, when the engine is under no load or light load, the movement of the cam nose 6' of the camshaft 6 is transmitted to the valve 1, and the drive is transmitted from the tappet body 5 to the shoulder 9 to the leaf spring 7 to the valve push rod 4. The movement is transmitted in the order of →valve arm 2 →valve 1, with the leaf spring 7 interposed between them.

したがって、板バネ７およびスキマＳの存在により動弁
系の弁クリアランスを零にしている。Therefore, the presence of the leaf spring 7 and the gap S makes the valve clearance of the valve train zero.

機関が高負荷時になると、板バネ７の突出部がタペット
本体５底部に接当し、カムノーズ６の動きを弁１に伝え
るに際し、スキマ７の存在がなくなり、板バネ７の厚み
のみの存在になり、その結果、カムの加速度上昇を滑ら
かにして動弁系の高速時振動を防止している。When the engine is under high load, the protruding part of the leaf spring 7 comes into contact with the bottom of the tappet body 5, and when transmitting the movement of the cam nose 6 to the valve 1, the gap 7 disappears and only the thickness of the leaf spring 7 exists. As a result, the increase in cam acceleration is smoothed out and vibrations of the valve train at high speeds are prevented.

以上要するに本考案は、筒状のタペット本体の底部上に
板バネを横設し、該板バネに凹部を形成するとともに、
該凹部成形による板バネ突出部と前記タペット本体の底
部との間に、機関無負荷時ないし軽負荷時のみ、スキマ
を生じるようにした内燃機関和平タペットであるから、
次の諸効果を奏する。In summary, the present invention includes horizontally installing a leaf spring on the bottom of a cylindrical tappet body, forming a recess in the leaf spring, and
This is an internal combustion engine peace tappet in which a gap is created between the leaf spring protrusion formed by the recess molding and the bottom of the tappet body only when the engine is under no load or under light load.
It has the following effects.

■ 筒状タペット本体の底部と弁押棒の下端との間にス
キマおよび横設した板バネを介しているので、機関軽負
荷時には、該板バネの弾力によって、常時、弁押棒とタ
ペット本体とを接触させて、いわゆる弁クリアランスを
なくシ、弁クリアランスによる各種悪影響を回避するこ
とができる。■ There is a gap and a horizontal plate spring between the bottom of the cylindrical tappet body and the lower end of the valve pusher rod, so when the engine is under light load, the elasticity of the leaf spring always keeps the valve pusher rod and tappet body connected. By bringing them into contact with each other, so-called valve clearance can be eliminated and various adverse effects caused by valve clearance can be avoided.

■ 高速ないし高負荷時には、カム面の加速上昇を円滑
（弁の動きはじめに生ずる１おどリョを回避するため緩
衝曲線１ランブヨを形成するが、特に、かかるランプ部
における加速が円滑に上昇する）にする。■ At high speeds or high loads, the acceleration of the cam surface is smoothly increased (a buffer curve is formed to avoid the 1st jolt that occurs at the beginning of valve movement, but in particular, the acceleration at such a ramp section is increased smoothly). do.

したがって、更に、動弁系の高速時振動を防止する。Therefore, vibration of the valve train system at high speed is further prevented.

■ 単に、板バネを横設しただけであり、かつ、板バネ
自体も型打ちによるから、構造簡単で、殊に、軽量化と
し、弁バネの固有振動を増大させない。(2) Since the leaf spring is simply installed horizontally, and the leaf spring itself is stamped, the structure is simple, particularly lightweight, and does not increase the natural vibration of the valve spring.

■ しかも、スキマ、およびスキマを零にする密着寸法
法の管理がコイルスプリングに比べ、容易で機関に信頼
性を与えることができる。■ Moreover, the management of the gap and the tight dimension method to eliminate the gap is easier than with coil springs, and it can provide reliability to the engine.

■ 一般の弁押棒とタペット本体との接触部は、これら
がはずれないように、弁押棒の端部を球状とし、タペッ
ト本体の底部に凹部を形威し、これらの接触部を夫々焼
入れしているが、本考案の場合、板バネの凹部の介在に
よって、タペット本体の底部の焼入れを省くことができ
る。■ In order to prevent the contact between the general valve pusher rod and the tappet body from coming off, the end of the valve pusher rod is made into a ball shape, a recess is formed on the bottom of the tappet body, and these contact areas are hardened. However, in the case of the present invention, hardening of the bottom of the tappet body can be omitted due to the interposition of the recessed portion of the leaf spring.

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

第１図は動弁系の全体図、第２図は本考案実施例の要部
断面図、第３図は従来例の要部断面図を示す。 ４・・・・・・弁押棒、５・・・・・・タペット本体、
６′・・・・・・カムノーズ、７・・・・・・板バネ、
Ｓ・・・・・・スキマ。FIG. 1 is an overall view of a valve train, FIG. 2 is a cross-sectional view of a main part of an embodiment of the present invention, and FIG. 3 is a cross-sectional view of a main part of a conventional example. 4... Valve pusher rod, 5... Tappet body,
6'...cam nose, 7...plate spring,
S... gap.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 筒状のタペット本体の底部上に板バネを横設し、該板バ
ネに凹部を形成するとともに、該凹部の弁押棒の球状下
端を当接し、該凹部成形による板バネの凹部反対側の突
出部と前記タペット本体の底部との間に、機関無負荷な
いし軽負荷時のみ、スキマを生じるようにした内燃機関
用平タペット。A leaf spring is installed horizontally on the bottom of the cylindrical tappet body, a recess is formed in the leaf spring, and the spherical lower end of the valve push rod is brought into contact with the recess, and the side opposite to the recess of the leaf spring is protruded by forming the recess. A flat tappet for an internal combustion engine in which a gap is created between the bottom part of the tappet body and the bottom part of the tappet body only when the engine is under no load or under light load.