JPS61160507A - Four valve type engine - Google Patents

Four valve type engine

Info

Publication number
JPS61160507A
JPS61160507A JP182585A JP182585A JPS61160507A JP S61160507 A JPS61160507 A JP S61160507A JP 182585 A JP182585 A JP 182585A JP 182585 A JP182585 A JP 182585A JP S61160507 A JPS61160507 A JP S61160507A
Authority
JP
Japan
Prior art keywords
intake
exhaust
valves
valve
camshaft
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP182585A
Other languages
Japanese (ja)
Inventor
Hiroyuki Oda
博之 小田
Akira Kageyama
明 陰山
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mazda Motor Corp
Original Assignee
Mazda Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mazda Motor Corp filed Critical Mazda Motor Corp
Priority to JP182585A priority Critical patent/JPS61160507A/en
Publication of JPS61160507A publication Critical patent/JPS61160507A/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/047—Camshafts
    • F01L1/053—Camshafts overhead type
    • 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
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/181—Centre pivot rocking arms
    • 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
    • F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
    • F02B2275/20—SOHC [Single overhead camshaft]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F1/42—Shape or arrangement of intake or exhaust channels in cylinder heads
    • F02F1/4214—Shape or arrangement of intake or exhaust channels in cylinder heads specially adapted for four or more valves per cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F2001/244—Arrangement of valve stems in cylinder heads
    • F02F2001/245—Arrangement of valve stems in cylinder heads the valve stems being orientated at an angle with the cylinder axis

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

PURPOSE:To prevent load from being concentrated to a cam shaft, by alternately arranging intake rocker arms and exhaust rocker arms along one cam shaft so that four valves are opened and closed for every engine cylinder. CONSTITUTION:Each engine cylinder is provided with two intake valves and two exhaust valves which are driven by one cam shaft 39. Intake rocker arms 49 and exhaust rocker arms 50 are alternately arranged along the cam shaft 39. With this arrangement it is possible to eliminate such a risk that two spring reaction forces are concentrated to the center of the cam shaft 39 between bearing sections, and therefore, a deflection in the cam shaft may be reduced, and fatigue and abrasion in bearings are reduced, thereby it is possible to enhance the durabilities of the cam shaft and the bearings.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、１気筒について２個の吸気弁と２個の排気弁
とを備え、これらを１本の頭上カム軸により夫々ロッカ
ーアームを介して駆動するようにした４弁式エンジンに
関する。Detailed Description of the Invention (Industrial Application Field) The present invention has two intake valves and two exhaust valves for one cylinder, which are connected by one overhead camshaft through rocker arms. The present invention relates to a four-valve engine that is driven by a four-valve engine.

（従　　来　　技　　術） 自動車用等のエンジンとして、１気筒について２個の吸
気弁と２個の排気弁とを備えた４弁式エンジンが実用化
されている。このエンジンによれば、吸気充填効率や排
気効率が向上して燃焼状態が改善されることにより、エ
ンジンの高出力化が実現される。一方、吸気弁と排気弁
とを夫々異なるカム軸で駆動するようにした２頭上カム
軸式エンジンが実用化されている。このエンジンによれ
ば、動弁機構におけるロッカーアームが廃止されること
により、高回転化の妨げとなる往復慣性質量が低減され
てエンジンの高回転化が可能となる。(Prior Art) Four-valve engines, each having two intake valves and two exhaust valves per cylinder, have been put into practical use as engines for automobiles and the like. According to this engine, the intake air filling efficiency and the exhaust efficiency are improved, and the combustion state is improved, thereby realizing high output of the engine. On the other hand, a dual overhead camshaft engine in which the intake valve and the exhaust valve are driven by different camshafts has been put into practical use. According to this engine, by eliminating the rocker arm in the valve mechanism, the reciprocating inertial mass that impedes high engine speed is reduced, making it possible to increase the engine speed.

しかし、この２頭上カム軸式エンジンは、構造が著しく
複雑化するのでコストが高く付く難点がある。However, this double overhead camshaft engine has a disadvantage in that it has a significantly complicated structure and is therefore expensive.

そこで、高出力は要するが、特に高回転を要しないエン
ジンの場合は、１気筒について吸気弁及び排気弁を夫々
２個備えると共に、これらの弁を１本の頭上カム軸で駆
動する構造として、所要の出力を確保し且つコストを低
減することが考えられる。このような４弁１頭上カム軸
式エンジンとしては、例えば特開昭５．７−１０２５０
６号公報に開示されたエンジンがある。このエンジンは
、第６．７図に示すように、１つの燃焼室１について２
個の吸気弁２，２と２個の排気弁３，３とを四角形状に
配置し、且つ燃焼室１の中央部上方に１本のカム軸４を
配設すると共に、該カム軸４に２個の吸気カム４ａ　、
４ａと２個の排気カム４ｂ。Therefore, in the case of an engine that requires high output but does not require particularly high rotation, a structure is adopted in which each cylinder has two intake valves and two exhaust valves, and these valves are driven by one overhead camshaft. It is possible to secure the required output and reduce costs. An example of such a 4-valve, 1-overhead camshaft engine is the Japanese Patent Application Laid-open No. 5.7-10250.
There is an engine disclosed in Publication No. 6. As shown in Fig. 6.7, this engine has two combustion chambers for one combustion chamber 1.
The intake valves 2, 2 and the two exhaust valves 3, 3 are arranged in a square shape, and one camshaft 4 is arranged above the center of the combustion chamber 1. two intake cams 4a,
4a and two exhaust cams 4b.

４ｂとを形成し、これらのカム４ａ　、　４ａ　、　４
ｂ　。4b, and these cams 4a, 4a, 4
b.

４ｂによって夫々吸気弁用ロッカーアーム５．５及び排
気弁用ロッカーアーム６．６を介して上記吸気弁２，２
及び排気弁３．３を駆動するようにしたものである。し
かし、このエンジンにおいては、カム軸４における両端
の軸受７，７間において、２個の吸気カム４ａ、４ａな
いし吸気弁用ロッカーアーム５．５を中央部に隣接して
配置し、その両側における上記軸受７．７寄りに２個の
排気カム４ｂ、４ｂないし排気弁用ロッカーアーム６．
６を配置している関係で以下のような問題が生じる。つ
まり上記多弁２．２，３．３は、夫々対応するカム４ａ
　、４ａ　、４ｂ　、４ｂないしロッカーアーム５．５
．６．６を介してバルブスプリング８・・・８に抗して
開かれるが、その時に該バルブスプリング８・・・８の
反力がロッカーアーム５゜５．６．６を介して上記カム
４ａ　、　４ａ　、　４ｂ　。4b, the intake valves 2, 2 are connected via the intake valve rocker arm 5.5 and the exhaust valve rocker arm 6.6, respectively.
and the exhaust valve 3.3. However, in this engine, two intake cams 4a, 4a or intake valve rocker arms 5.5 are arranged adjacent to the center between the bearings 7, 7 at both ends of the camshaft 4, and Two exhaust cams 4b, 4b or exhaust valve rocker arm 6 near the bearing 7.7.
The following problem arises due to the arrangement of 6. In other words, the multiple valves 2.2 and 3.3 each have a corresponding cam 4a.
, 4a , 4b , 4b or rocker arm 5.5
．． The valve springs 8...8 are opened against the valve springs 8...8 through the rocker arm 5. , 4a, 4b.

４ｂに夫々作用することになる。その場合に、２個の吸
気弁２，２及び２個の排気弁３，３は夫々同時に開くの
で、カム４ａ　、４ａ　、４ｂ　、４ｂが上記のような
配置構成であると、特に吸気弁２゜２の開時に、２［１
の吸気カム４ａ、４ａが隣接して配置されたカム軸４の
中央部にスプリング反力が集中して作用することになる
。そのため、該反力によりカム軸４の中央部が填み、ま
た、該軸４の軸受７．７はカム軸４が撓んだ状態でその
両端を支えるので、該カム軸４の疲労が促進されると共
に、軸受７，７が早期に摩耗し、よって両者の耐久性が
低下するという問題が生じる。4b, respectively. In that case, the two intake valves 2, 2 and the two exhaust valves 3, 3 open simultaneously, so if the cams 4a, 4a, 4b, 4b are arranged as described above, especially the intake valve 2 When opening ゜2, 2[1
The spring reaction force concentrates on the center of the camshaft 4 where the intake cams 4a, 4a are arranged adjacent to each other. Therefore, the center portion of the camshaft 4 is compressed by the reaction force, and since the bearings 7.7 of the shaft 4 support both ends of the camshaft 4 in a bent state, fatigue of the camshaft 4 is accelerated. At the same time, a problem arises in that the bearings 7, 7 are worn out early, and the durability of both is reduced.

（発　　明　　の　　目　　的） 本発明は従来における上記のような実情に対処するもの
で、各２個の吸、排気弁を１本の頭上カム軸により夫々
ロッカーアームを介して駆動するようにしたエンジンに
おいて、上記カム軸の中央部にスプリング反力が集中し
て作用することを防止し、これにより、該カム軸ないし
該軸を支持する軸受に作用する荷重を軽減して、これら
の耐久性を向上させることを目的とする。(Object of the Invention) The present invention is intended to address the above-mentioned conventional situation, and includes a system in which each of the two intake and exhaust valves is driven by one overhead camshaft via a rocker arm. In an engine, the spring reaction force is prevented from acting concentratedly on the center of the camshaft, thereby reducing the load acting on the camshaft or the bearings that support the shaft, thereby improving their durability. The purpose is to improve

（発　　明　　の　　構　　成） 本発明に係る４弁式エンジンは、上記目的達成のため次
のように構成したことを特徴とする。(Structure of the Invention) A four-valve engine according to the present invention is characterized by having the following structure in order to achieve the above object.

即ち、１気筒について２個の吸気弁及び２個の排気弁と
、これらの弁に対応する２個の吸気弁用ロッカーアーム
及び２個の排気弁用ロッカーアームとを備え、これらの
ロッカーアームを介して上記多弁を１本の頭上カム軸で
駆動するようにした構成において、上記吸気弁用ロッカ
ーアームと排気弁用ロッカーアームとをカム軸に沿って
交互に配置する。このような構成によれば、各２個の吸
気弁及び排気弁の開時に、夫々カム軸に同時に働くバル
ブスプリングの反力が該カム軸における離れた位置に作
用することになる。That is, one cylinder is provided with two intake valves and two exhaust valves, two intake valve rocker arms and two exhaust valve rocker arms corresponding to these valves, and these rocker arms are In the configuration in which the multiple valves are driven by one overhead camshaft through the intake valve rocker arm and the exhaust valve rocker arm are arranged alternately along the camshaft. According to this configuration, when each of the two intake valves and the two exhaust valves are opened, the reaction forces of the valve springs that act simultaneously on the camshafts act on separate positions on the camshafts.

（発　　明　　の　　効　　果） 上記の構成によれば、４弁１頭上カム軸式エンジンにお
いて、カム軸における軸受部間の中央に２つのスプリン
グ反力が集中して作用することがなくなるので、該カム
軸の撓みが軽減されることになり、これに伴ってカム軸
の疲労や軸受の摩耗等が低減され、もって該カム軸や軸
受の耐久性が向上することになる。(Effects of the Invention) According to the above configuration, in a 4-valve, 1-overhead camshaft engine, the two spring reaction forces do not concentrate and act on the center between the bearings on the camshaft. Deflection of the camshaft is reduced, and fatigue of the camshaft and wear of the bearing are thereby reduced, thereby improving the durability of the camshaft and the bearing.

（実　　施　　例） 以下、本発明の実施例について説明する。(Example) Examples of the present invention will be described below.

第１．２図に示すように、エンジン２０は複数のシリン
ダを列状に配置したシリンダブロック２１と、該ブロッ
ク２１の上面にガスケット２２を介して設置されたシリ
ンダヘッド２３とを有し、シリンダブロック２１におけ
るシリンダ２４の内周面と、該シリンダ２４内に嵌合さ
れたピストン２５の上面と、シリンダヘッド２３の上方
に窪まされた下面２３ａとで燃焼室２６が画成されてい
る。また、シリンダヘッド２３には、一方の側面２３ｂ
から上記燃焼室２６に通じる２つの吸気ボート２７．２
７と、他方の側面２３Ｃから燃焼至２６に通じる２つの
排気ボート２８．２８とが設けられ、これら各ボートの
燃焼至２６への開口部２７ａ　、’　２７ａ　、２８ａ
　、２８ａがシリンダヘッド下面２３ａに四角形状に配
設されていると共に、各開口部２７ａ　、２７ａ　、２
８ａ　、２８ａを夫々開閉する２個の吸気弁２９．２９
と２個の排気弁３０．３０とが備えられている。これら
の合弁の上方に延びるステム部２９ａ　、２９ａ　、３
０ａ　。As shown in FIG. 1.2, the engine 20 has a cylinder block 21 in which a plurality of cylinders are arranged in a row, and a cylinder head 23 installed on the upper surface of the block 21 via a gasket 22. A combustion chamber 26 is defined by the inner peripheral surface of the cylinder 24 in the block 21, the upper surface of the piston 25 fitted into the cylinder 24, and the lower surface 23a recessed above the cylinder head 23. Further, the cylinder head 23 has one side surface 23b.
two intake boats 27.2 leading from the combustion chamber 26 to the combustion chamber 26;
7 and two exhaust boats 28,28 leading from the other side 23C to the combustion chamber 26, each of which has an opening 27a,' 27a, 28a to the combustion chamber 26.
, 28a are arranged in a square shape on the lower surface 23a of the cylinder head, and each opening 27a, 27a, 2
Two intake valves 29.29 that open and close 8a and 28a, respectively.
and two exhaust valves 30,30. Stem portions 29a, 29a, 3 extending above these joint ventures
0a.

３０ａはシリンダヘッド２３の上面２３ｄから上方に突
出され、その上端部に夫々固着されたスプリングリテー
ナ３１．３１．３２．３２と、シリンダヘッド２３の上
面２３ｄにおける各ステム部２９ａ　、２９ａ　、３０
ａ　、３０ａの突出部に形成されたスプリングシート部
３３．３３．３４．３４との間には、合弁２９．２９．
３０．３０を夫々開方向に付勢するバルブスプリング３
５．３５゜３６．３６が装着されている。また、シリン
ダヘッド２３には、各気筒における２個の排気ポート２
８．２８間において排気弁３０．３０に交差するように
点火プラグ挿入孔３７が傾斜状に設けられ、その先端部
３７ａが燃焼ｖ２６の上部中央部に開口されていると共
に、その侵端部３７ｂは、排気ボート２８．２８の開口
部２８ｂ、２８１＋と排気弁３０．３０のスプリングシ
ート部３４，３４との間から該ヘッド２３の上部外側方
を臨むように開口され、該孔３７内に点火プラグ３８が
装着されている。一方、シリンダヘッド２３の上部中央
における上記吸気弁２９．２９と排気弁３０゜３０とに
挾まれた位置には、エンジン２０のクランク軸方向に延
びる１本のカム軸３９が配設されている。このカム軸３
９のジャーナル部４０・・・４０は、第１図及び第３〜
５図に示すように、シリンダヘッド２３の上面中央部に
おける隣接気筒間及びヘッド両端部に立設された軸受壁
４１・・・４１と、各軸受壁４１・・・４１に夫々２本
のボルト４２゜４２を用いて固着された軸受キャップ４
３・・・４３とで形成された軸受４４・・・４４に回転
自在に軸承されている。そして、該カム軸３９における
隣接ジャーナル部４０．４０間には、１気筒分の２個の
吸気カム４５．４５と２個の排気カム４６，４６とが形
成され、また、該カム軸３９の上部両側に平行に架設さ
れた２本のロッカーアーム軸４７゜４８に【１．１気筒
について２個の吸気弁用ロッカーアーム４９．４９及び
２ＷＡの排気弁用ロッカーアーム５０．５０が夫々揺動
自在に支持され、各ロッカーアーム４９．４９．５０．
５０の両端が対応する吸気カム４５．４５及び排気カム
４６゜４６の周面と、吸気弁のステム部２９ａ　、２９
ａ及び排気弁のステム部３０ａ　、３０ａの上端とに夫
々対接されていることにより、クランク軸に同期するカ
ム軸３９の回転によって各ロッカーアーム４９．４９．
５０．５０を介して合弁２９，２９．３０．３０が上記
バルブスプリング３５．３５．３６．３６に抗して開動
されるようになっている。30a projects upward from the upper surface 23d of the cylinder head 23, and includes spring retainers 31, 31, 32, and 32 fixed to their upper ends, respectively, and stem portions 29a, 29a, 30 on the upper surface 23d of the cylinder head 23.
There is a joint valve 29.29.a between the spring seat portion 33.33.34.34 formed on the protruding portion of 30a.
Valve spring 3 that biases 30 and 30 in the opening direction, respectively.
5.35°36.36 are installed. The cylinder head 23 also has two exhaust ports 2 for each cylinder.
An ignition plug insertion hole 37 is provided in an inclined manner so as to intersect the exhaust valve 30.30 between 8.28 and 30.30, and its tip 37a is opened at the upper center of the combustion v26, and its intrusive end 37b is opened so as to face the upper outer side of the head 23 from between the openings 28b, 281+ of the exhaust boat 28.28 and the spring seat portions 34, 34 of the exhaust valve 30.30, and the ignition is inserted into the hole 37. A plug 38 is attached. On the other hand, a single camshaft 39 extending in the direction of the crankshaft of the engine 20 is disposed at a position sandwiched between the intake valve 29, 29 and the exhaust valve 30, 30 at the center of the upper part of the cylinder head 23. . This camshaft 3
9 journal parts 40...40 are shown in FIG.
As shown in Fig. 5, bearing walls 41...41 are provided upright between adjacent cylinders at the center of the upper surface of the cylinder head 23 and at both ends of the head, and two bolts are attached to each bearing wall 41...41. Bearing cap 4 fixed using 42°42
3...43 are rotatably supported by bearings 44...44. Two intake cams 45.45 and two exhaust cams 46, 46 for one cylinder are formed between adjacent journal portions 40.40 of the camshaft 39. Two rocker arm shafts 47 and 48 installed in parallel on both sides of the upper part swing [1. Two intake valve rocker arms 49, 49 and 2WA exhaust valve rocker arms 50, 50 for each cylinder] respectively. Each rocker arm 49.49.50.
Both ends of the intake cam 45, 45 and the exhaust cam 46, 46, and the stem portions 29a and 29 of the intake valve have corresponding ends.
a and the upper ends of the exhaust valve stem portions 30a, 30a, respectively, so that rotation of the camshaft 39 in synchronization with the crankshaft causes each rocker arm 49, 49.
50.50, the joint valves 29, 29.30.30 are opened against the valve springs 35.35.36.36.

然して、上記カム軸３９における２個の吸気カム４５．
４５及び２個の排気カム４６．４６は隣接ジャーナル部
４０．４０間において交互に配置されていると共に、こ
れに伴って２個の吸気弁用ロッカーアーム４９．４９及
び２個の排気弁用ロッカーアーム５０．５０もカム軸３
９に沿って両側から交互に配置されている。ここで、第
５図に示すように、ロッカーアーム軸４７．４８は、軸
受キャップ４３の上面に設けられた半円状凹部４３ａ　
、４３ａに下半部を嵌合され、且つ上方から軸受キャッ
プ４３を軸受壁４１に固着する上記のボルト４２．４２
によって挟持部材５１．５１を介して締め付けられるこ
とにより固定されている。Therefore, the two intake cams 45. on the camshaft 39.
45 and two exhaust cams 46,46 are arranged alternately between adjacent journal parts 40,40, and accordingly two intake valve rocker arms 49,49 and two exhaust valve rockers. Arm 50.50 is also camshaft 3
They are arranged alternately from both sides along 9. Here, as shown in FIG.
, 43a, and fixes the bearing cap 43 to the bearing wall 41 from above.
It is fixed by being tightened via the clamping members 51.51.

また、２個の吸気弁用ロッカーアーム４９．４９及び排
気弁用ロッカーアーム５０．５０間にはスプリング５２
．５２が介設され、これらのロッカーアーム４９．４９
．５０．５０を所定の位置に埼 保革するようになっている。Also, a spring 52 is installed between the two intake valve rocker arms 49.49 and the exhaust valve rocker arms 50.50.
．． 52 are interposed and these rocker arms 49.49
．． 50.50 is to be adjusted to a predetermined position.

上記の構成によれば、エンジン２００作動時にクランク
軸に同期するカム軸３９の回転によって、吸気行程時に
２個の吸気弁２９．２９が、また排気行程時に２個の排
気弁３０．３０が夫々同時に開かれるが、これらの弁２
９．２９又は３０，３０の開時にはこれらを開方向に付
勢するバルブスプリング３５．３５又は３６．３６の反
力が口・ソカーアーム４９．４９又は５０．５０を介し
てカム軸３．９のカム４５．４５又は４６．４６に同時
に作用する。つまり、第４図に示すように、例えば吸気
行程時にはカム軸３つにおける隣接ジャーナル部４０．
４０聞くおける２ＷＡの吸気カム４５゜４５のリフト部
に吸気弁用ロッカーアーム４９゜４９が対接し、該ロッ
カーアーム４９．４９の揺動により２個の吸気弁２９．
２９が開かれるが、この時バルブスプリング３５．３５
の反力Ｆ、　Ｆが２個の吸気カム４５．４５に同時に作
用し、同様に排気行程時には２個の排気カム４６．４６
にバルブスプリング３６．３６の反力Ｆ’　、Ｆ’　が
同時に作用する。そして、これらの反力Ｆ、Ｆ又はＦ’
　、Ｆ’　は両側の軸受４４．４４に受は止められる。According to the above configuration, the rotation of the camshaft 39 in synchronization with the crankshaft when the engine 200 is in operation causes the two intake valves 29.29 to open during the intake stroke, and the two exhaust valves 30.30 to open during the exhaust stroke. Two of these valves are opened at the same time.
9.29 or 30, 30, the reaction force of the valve spring 35.35 or 36.36 which urges them in the opening direction is applied to the camshaft 3.9 via the mouth/soaker arm 49.49 or 50.50. It acts simultaneously on cams 45.45 or 46.46. That is, as shown in FIG. 4, for example, during the intake stroke, adjacent journal portions 40.
An intake valve rocker arm 49.49 is in contact with the lift portion of the 2WA intake cam 45.45 at the 40.degree.
29 is opened, but at this time the valve spring 35.35
The reaction forces F and F act simultaneously on the two intake cams 45.45, and similarly, during the exhaust stroke, the two exhaust cams 46.46
The reaction forces F' and F' of the valve springs 36 and 36 act simultaneously. And these reaction forces F, F or F'
, F' are fixed to bearings 44 and 44 on both sides.

然して、上記の構成によれば、各２個の吸気弁用ロッカ
ーアーム４９．４９と排気弁用ロッカーアーム５０．５
０とがカム軸３９に沿って交互に配置され、これに伴っ
て該軸３９における各２個の吸気カム４５．４５と排気
カム４６．４６も交互に配置されているので、第４図に
示すように吸気行程時に吸気カム４５．４５に夫々作用
するスプリング反力Ｆ、Ｆ及び排気行程時に排気カム４
６．４６に作用するスプリング反力Ｆ′。However, according to the above configuration, two intake valve rocker arms 49.49 and two exhaust valve rocker arms 50.5 are provided.
0 are alternately arranged along the cam shaft 39, and along with this, the two intake cams 45, 45 and the two exhaust cams 46, 46 on the shaft 39 are also arranged alternately. As shown, the spring reaction forces F and F that act on the intake cams 45 and 45 respectively during the intake stroke and the exhaust cam 4 during the exhaust stroke
Spring reaction force F' acting on 6.46.

Ｆ′は、カム軸における隣接ジャーナル部４０゜４０間
において離れた位置に作用することになる。F' acts at a remote position between adjacent journal portions 40.degree. 40 on the camshaft.

これにより、中央部に同時に反力が作用することによる
カム軸３９の撓みや上記軸受４４．４４に作用する荷重
が軽減され、これらの耐久性が向上する。This reduces the deflection of the camshaft 39 and the load acting on the bearings 44, 44 due to reaction force simultaneously acting on the central portion, and improves their durability.

尚、この実施例では、燃焼室２６の中央上方にカム軸３
９が配置され、且つ該カム軸３９の両側に吸、排気弁２
９．２９．３０．３０が対称的に配置されていることに
伴って、該弁２９，２９゜３０．３０について２個の吸
気弁用ロッカーアーム４９．４９及び２個の排気弁用ロ
ッカーアーム５０．５０が第３図に示す燃焼室２６の中
心０の周りに点対称に配置されている。従って内側に位
置する吸気弁用ロッカーアーム４９′と排気弁用ロッカ
ーアーム５０′及び外側に位置する吸気弁用ロッカーア
ーム４９″と排気弁用ロッカーアーム５０″を夫々同形
状とすることが可能となり、これらの共通化が図られて
いる。In this embodiment, the camshaft 3 is located above the center of the combustion chamber 26.
9 is arranged, and intake and exhaust valves 2 are arranged on both sides of the camshaft 39.
Due to the symmetrical arrangement of the valves 9.29.30.30, there are two intake valve rocker arms 49.49 and two exhaust valve rocker arms for the valves 29,29°30.30. 50.50 are arranged point-symmetrically around the center 0 of the combustion chamber 26 shown in FIG. Therefore, it is possible to make the intake valve rocker arm 49' and the exhaust valve rocker arm 50' located on the inside, and the intake valve rocker arm 49'' and the exhaust valve rocker arm 50'' located on the outside to have the same shape. , these are being standardized.

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

第１〜５図は本発明の実施例を示すもので、第１図は燃
焼室の中央で切断したシリンダヘッド及びその周辺の縦
断正面図、第２図は第１図Ｉｆ−ＩＩ線で切断したシリ
ンダヘッド単体の横断平面図、第３図は動弁機構の平面
図、第４図は第３図■−■線で切断したカム軸の一部側
面図、第５図は第３図ｖ−ｖ線で切断したカム軸の軸受
部の縦断正面図である。第６．７図は従来例を示すシリ
ンダヘッド及びその周辺の縦断正面図及び横断平面図で
ある。 ２９・・・吸気弁、３０・・・排気弁、３９・・・カム
軸、４９・・・吸気弁用ロッカーアーム、５０・・・排
気弁用ロッカーアーム。Figures 1 to 5 show embodiments of the present invention. Figure 1 is a longitudinal sectional front view of the cylinder head and its surroundings cut at the center of the combustion chamber, and Figure 2 is a cut along line If-II in Figure 1. Fig. 3 is a plan view of the valve mechanism, Fig. 4 is a partial side view of the camshaft taken along the line ■-■ in Fig. 3, and Fig. 5 is a cross-sectional plan view of the cylinder head alone. FIG. 3 is a longitudinal sectional front view of the bearing portion of the camshaft taken along the -v line. FIG. 6.7 is a vertical front view and a cross-sectional plan view of a cylinder head and its surroundings, showing a conventional example. 29... Intake valve, 30... Exhaust valve, 39... Camshaft, 49... Rocker arm for intake valve, 50... Rocker arm for exhaust valve.

Claims (1)

【特許請求の範囲】[Claims] （１）１気筒について２個の吸気弁及び２個の排気弁と
、これらの弁に夫々対応する２個の吸気弁用ロッカーア
ーム及び２個の排気弁用ロッカーアームとが備えられ、
これらのロッカーアームを介して上記各弁が１本の頭上
カム軸で駆動されるように構成された４弁式エンジンで
あって、上記カム軸に沿って吸気弁用ロッカーアームと
排気弁用ロッカーアームとが交互に配置されていること
を特徴とする４弁式エンジン。(1) One cylinder is provided with two intake valves and two exhaust valves, and two intake valve rocker arms and two exhaust valve rocker arms corresponding to these valves, respectively;
A four-valve engine configured such that each of the valves is driven by one overhead camshaft via these rocker arms, and an intake valve rocker arm and an exhaust valve rocker are installed along the camshaft. A four-valve engine characterized by alternating arms.
JP182585A 1985-01-08 1985-01-08 Four valve type engine Pending JPS61160507A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP182585A JPS61160507A (en) 1985-01-08 1985-01-08 Four valve type engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP182585A JPS61160507A (en) 1985-01-08 1985-01-08 Four valve type engine

Publications (1)

Publication Number Publication Date
JPS61160507A true JPS61160507A (en) 1986-07-21

Family

ID=11512337

Family Applications (1)

Application Number Title Priority Date Filing Date
JP182585A Pending JPS61160507A (en) 1985-01-08 1985-01-08 Four valve type engine

Country Status (1)

Country Link
JP (1) JPS61160507A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5996405A (en) * 1982-11-24 1984-06-02 Yamaha Motor Co Ltd Overhead cam shaft type four-valve engine

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5996405A (en) * 1982-11-24 1984-06-02 Yamaha Motor Co Ltd Overhead cam shaft type four-valve engine

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