JPS6149112A - Valve moving mechanism of engine - Google Patents
Valve moving mechanism of engineInfo
- Publication number
- JPS6149112A JPS6149112A JP17205384A JP17205384A JPS6149112A JP S6149112 A JPS6149112 A JP S6149112A JP 17205384 A JP17205384 A JP 17205384A JP 17205384 A JP17205384 A JP 17205384A JP S6149112 A JPS6149112 A JP S6149112A
- Authority
- JP
- Japan
- Prior art keywords
- cam
- valve
- base circle
- ramp
- clearance
- 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
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/08—Shape of cams
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Valve-Gear Or Valve Arrangements (AREA)
Abstract
Description
【産業上の利用分野１
本発明は、油圧タペットを備えたエンジンの動弁機構に
関するもので、ざらに詳しくは、動弁機構におけるカム
に３０するものである。
【従来技術］
油圧タペット付エンジンの動弁機構は、実開昭５５−６
９１０４号公報に囲示されてるように従来公知である。
ところで、このタペット番よエンジンの熱膨張、艮明間
使用における摩耗等による静的変位は吸収できるものの
、カム軸が回転中に発生ずるカムの振動のような速い動
的変位は吸収できない。。
先行技術で使用されるでいるカムは、ベース円区間にお
いてカムベース円センターからの距離がどこでも一定で
あるため、カムの振動がバルブステムと同一方向に発生
１“ると、上述したように油圧タペットはカムの振動を
吸収できないため、動弁系のクリアランスは零になって
いることから、カムの振動はロッカアームを介して直接
バルブステムに伝達され、バルブを微氾押し上げること
になってしまう。このため、圧縮工程においてシリンダ
内の混合気が外に洩れてしまい、出力が低下する問題が
あった。
【発明の目的】
本発明は、上記問題を解決プ゛べく提案されたものであ
り、カムノーズ部と反対側のベース円区間では、ランプ
終りからランプ始まりにかけてベース円を偏移させるこ
とにより、カムの振動を吸収してバルブが微ω押し上げ
られることを防止するような油圧タペット付エンジンの
動弁Ｉａ溝を提供することを目的とするものである。
（発明の構成１
上記目的を達成するため、本発明は、油圧タペットを備
えたエンジンの動弁機構において、カムのプロフィルを
、カムノーズ部と反対側のベース円区間では、ランプ終
りからランプ始まりにかけてベース円センターからのｈ
ｎ値が順次小さくなるような直線勾配にしたことを特徴
とするものである。INDUSTRIAL APPLICATION FIELD 1 The present invention relates to a valve mechanism for an engine equipped with a hydraulic tappet, and more specifically, to a cam in the valve mechanism. [Prior art] The valve mechanism of an engine with hydraulic tappets was developed in 1986-6.
This is conventionally known as shown in Japanese Patent No. 9104. By the way, although this tappet number can absorb static displacement due to thermal expansion of the engine, wear during use, etc., it cannot absorb fast dynamic displacement such as vibration of the cam that occurs while the camshaft is rotating. . In the cam used in the prior art, the distance from the cam base circle center is constant everywhere in the base circle section, so when the cam vibration occurs in the same direction as the valve stem, the hydraulic tappet Since the valve train cannot absorb cam vibrations and the clearance of the valve train is zero, the cam vibrations are transmitted directly to the valve stem via the rocker arm, pushing the valve upward slightly. Therefore, there was a problem that the air-fuel mixture inside the cylinder leaked outside during the compression process, resulting in a decrease in output. [Object of the Invention] The present invention was proposed to solve the above problem, and it In the base circle section on the opposite side, the base circle is shifted from the end of the ramp to the beginning of the ramp to absorb cam vibrations and prevent the valve from being pushed up slightly. It is an object of the present invention to provide a valve Ia groove. (Structure 1 of the Invention In order to achieve the above object, the present invention provides a valve mechanism for an engine equipped with a hydraulic tappet. In the base circle section on the opposite side, h from the base circle center from the end of the ramp to the beginning of the ramp.
It is characterized by having a linear gradient such that the n value becomes smaller sequentially.
以下、図面を参照して本発明の一実施例を具体的に説明
する。
第１図において、符号１はカム、２はロッカアーム、３
は油圧タペット、４はバルブである。ロッカアーム２は
、油圧タペット３に球団節で支承され、カム１の回転に
より揺動してバルブ４を上下動させるようになっている
ものである。
本発明の動弁機構に使用されるカム１のプロフィルは、
第２図および第３図に示すように、カムノーズ部５と反
対側のベース円６区間では、ランプ終りＱｓからランプ
始まり、即ちバルブ４閉がらパルプ４間までの間では、
ベース円センター７からのｈｎ値はｈｌ〉１１□〉１）
、と順次小さくなるように一定角１真の下り勾配となっ
ている。つまりカム１はｏ、ｏｓｍｍ程度の偏移量を有
する偏移カムとなっている。この偏移量は加工ｖＪ度等
により多少変化することもある。なお第２図中、点線で
描かれた円８は従来のカムのベース円である。
本実施例は以上のような構成なので、カム１が矢印方向
く第１図および第２図参照）に回転すると、カム１はラ
ンプ終りＱｓ＜パルプ４閉）からランプ上のＱ４（バル
ブ４間）にかけてはロッカアーム２の周面から離れよう
とする動きになる。
即らランプ柊りＱ、で油圧タペット３の圧力学内のバネ
が伸びるため、圧力学内に入る油圧がそれに追従できず
時間と共に変化する油圧上昇に対し、カム１のベース円
６に形成されｌζ偏移曾は逃げ方向となるため、油圧タ
ペット３とカム１との間に微少クリアランスを生じ、こ
のクリアランスにより、カム１に発生ずる振動がガタに
よってバルブ４を押し上げるカム軸の動き代が形成され
るため、該振動やガタがロッカアーム２を介してバルブ
４に直接伝達されず、カム軸の振動が吸収されるのであ
る。Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In Fig. 1, numeral 1 is a cam, 2 is a rocker arm, and 3 is a cam.
is a hydraulic tappet, and 4 is a valve. The rocker arm 2 is supported by a hydraulic tappet 3 at a ball joint, and is swung by the rotation of the cam 1 to move the valve 4 up and down. The profile of the cam 1 used in the valve train of the present invention is as follows:
As shown in FIGS. 2 and 3, in the section of the base circle 6 on the opposite side of the cam nose portion 5, from the end of the ramp Qs to the beginning of the ramp, that is, from the time the valve 4 is closed to the time between the pulp 4,
The hn value from the base circle center 7 is hl〉11□〉1)
, it becomes a downward slope of a constant angle of 1 true so that it becomes smaller sequentially. In other words, the cam 1 is a shift cam having a shift amount of about o, osmm. This amount of deviation may change somewhat depending on the degree of machining vJ, etc. In FIG. 2, the circle 8 drawn with a dotted line is the base circle of the conventional cam. This embodiment has the above-described configuration, so when the cam 1 rotates in the direction of the arrow (see Figures 1 and 2), the cam 1 moves from the end of the ramp Qs<pulp 4 closed) to Q4 on the ramp (between valves 4 and 4). ), it moves away from the circumferential surface of the rocker arm 2. In other words, because the spring in the pressure field of the hydraulic tappet 3 is stretched by the ramp hiragiri Q, the hydraulic pressure entering the pressure field cannot follow it, and the lζ deviation formed in the base circle 6 of the cam 1 is generated in response to the rise in hydraulic pressure that changes over time. Since the movement is in the escape direction, a slight clearance is created between the hydraulic tappet 3 and the cam 1, and this clearance creates a movement allowance for the camshaft that causes vibrations generated in the cam 1 to push up the valve 4 due to backlash. Therefore, the vibration and backlash are not directly transmitted to the valve 4 via the rocker arm 2, and the vibration of the camshaft is absorbed.
以上説明したように、本発明は、カム１のプロフィルを
、カムノーズ部５と反対側のベース円６区間では、ラン
プ柊りＱｓからランプ始まりにかけてベース円センター
７からのｈｎ値がり、 ＞ ｈ２〉１）３ ど順次小さ
くなるような直線勾配にしたので、油圧タペット３とカ
ム１との間にクリアランスが生じ、このクリアランスに
よって、カム軸の微振動やガタによりバルブ４が微ｍ押
し上げられるのを防止できるため、圧縮工程におけるシ
リンダ内混合気の洩れを防止でき、出力の向上を達成し
得る。
また、カム１とロッカアーム２間が離れる動きを示すこ
とから、ロッカアーム２とバルブ４の接触部も離れる動
きを示し、これにより接触部間にオイル飛沫を吸引して
油膜が形成されることから、従来のものより潤滑が良好
となり、各接触部の耐久性の向上が図られる。
更に、バルブ４がパルプスプリングによってシート部に
緊密に圧着されることから、バルブ４の熱の逃げ道が確
保され、バルブ４の熱破壊を防止することもできる。
以上のように、本発明は、簡単な構成でありながら上述
した多くの効果を有するため、その実施効果は多大なも
のがある。As explained above, in the present invention, the profile of the cam 1 is such that in the section of the base circle 6 on the opposite side from the cam nose portion 5, the hn value from the base circle center 7 increases from the ramp hole Qs to the ramp start, >h2> 1) 3 Since the linear slope gradually decreases, a clearance is created between the hydraulic tappet 3 and the cam 1, and this clearance prevents the valve 4 from being pushed up by a slight meter due to slight vibrations or play of the camshaft. Since this can be prevented, leakage of the air-fuel mixture in the cylinder during the compression process can be prevented, and an improvement in output can be achieved. Furthermore, since the cam 1 and the rocker arm 2 move apart, the contact area between the rocker arm 2 and the valve 4 also moves away, and this causes oil droplets to be sucked between the contact areas and an oil film is formed. The lubrication is better than the conventional one, and the durability of each contact part is improved. Furthermore, since the valve 4 is tightly pressed against the seat portion by the pulp spring, an escape route for the heat of the valve 4 is ensured, and thermal damage to the valve 4 can also be prevented. As described above, the present invention has many of the above-mentioned effects even though it has a simple configuration, and therefore has great effects when implemented.
第１図は本発明が適用される油圧タベツｊ・付エンジン
動弁機構の概略図、第２図は本発明の油圧クペット（＝
Ｉエンジン動弁機構に使用されるカムの一実施例を示す
断面図、第３図は第２図に示されるカムのプロフィル展
間図である。
１・・・カム、２・・・ロッカアーム、３・・・油圧タ
ペット、４・・・バルブ、５・・・カムノーズ部、６・
・・ベース円、７・・・ベース円センター。
第１図
第２図Fig. 1 is a schematic diagram of an engine valve mechanism with a hydraulic valve to which the present invention is applied, and Fig. 2 is a schematic diagram of an engine valve mechanism with a hydraulic valve (
FIG. 3 is a cross-sectional view showing one embodiment of a cam used in the I engine valve mechanism, and FIG. 3 is a profile diagram of the cam shown in FIG. 2. DESCRIPTION OF SYMBOLS 1...Cam, 2...Rocker arm, 3...Hydraulic tappet, 4...Valve, 5...Cam nose part, 6...
...Base circle, 7...Base circle center. Figure 1 Figure 2
Claims (1)
ムのプロフィルを、カムノーズ部と反対側のベース円区
間では、ランプ終りからランプ始まりにかけてベース円
センターからのｈｎ値が順次小さくなるような直線勾配
にしたことを特徴とする動弁機構。In the valve train of an engine equipped with a hydraulic tappet, the cam profile is made to have a linear slope in the base circle section on the opposite side of the cam nose so that the hn value from the base circle center gradually decreases from the end of the ramp to the beginning of the ramp. A valve mechanism characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17205384A JPS6149112A (en) | 1984-08-17 | 1984-08-17 | Valve moving mechanism of engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17205384A JPS6149112A (en) | 1984-08-17 | 1984-08-17 | Valve moving mechanism of engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6149112A true JPS6149112A (en) | 1986-03-11 |
Family
ID=15934657
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17205384A Pending JPS6149112A (en) | 1984-08-17 | 1984-08-17 | Valve moving mechanism of engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6149112A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01224406A (en) * | 1988-03-03 | 1989-09-07 | Honda Motor Co Ltd | Device for valve system of internal combustion engine |
| JPH01253511A (en) * | 1988-04-01 | 1989-10-09 | Honda Motor Co Ltd | Valve system for internal combustion engine |
| JPH01301903A (en) * | 1988-05-30 | 1989-12-06 | Honda Motor Co Ltd | Valve system for internal combustion engine |
| JPH01301904A (en) * | 1988-05-30 | 1989-12-06 | Honda Motor Co Ltd | Valve system for internal combustion engine |
| EP2625393A1 (en) * | 2010-10-08 | 2013-08-14 | Pinnacle Engines, Inc. | Positive control (desmodromic) valve systems for internal combustion engines |
-
1984
- 1984-08-17 JP JP17205384A patent/JPS6149112A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01224406A (en) * | 1988-03-03 | 1989-09-07 | Honda Motor Co Ltd | Device for valve system of internal combustion engine |
| JPH01253511A (en) * | 1988-04-01 | 1989-10-09 | Honda Motor Co Ltd | Valve system for internal combustion engine |
| JPH01301903A (en) * | 1988-05-30 | 1989-12-06 | Honda Motor Co Ltd | Valve system for internal combustion engine |
| JPH01301904A (en) * | 1988-05-30 | 1989-12-06 | Honda Motor Co Ltd | Valve system for internal combustion engine |
| US8910606B2 (en) | 2009-11-23 | 2014-12-16 | Pinnacle Engines, Inc. | Positive control (desmodromic) valve systems for internal combustion engines |
| EP2625393A1 (en) * | 2010-10-08 | 2013-08-14 | Pinnacle Engines, Inc. | Positive control (desmodromic) valve systems for internal combustion engines |
| EP2625393A4 (en) * | 2010-10-08 | 2014-04-30 | Pinnacle Engines Inc | Positive control (desmodromic) valve systems for internal combustion engines |
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