JPS61138823A - Four-valve type engine - Google Patents

Four-valve type engine

Info

Publication number
JPS61138823A
JPS61138823A JP59261337A JP26133784A JPS61138823A JP S61138823 A JPS61138823 A JP S61138823A JP 59261337 A JP59261337 A JP 59261337A JP 26133784 A JP26133784 A JP 26133784A JP S61138823 A JPS61138823 A JP S61138823A
Authority
JP
Japan
Prior art keywords
combustion chamber
insertion hole
engine
exhaust
spark plug
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
JP59261337A
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 JP59261337A priority Critical patent/JPS61138823A/en
Priority to US06/804,839 priority patent/US4741302A/en
Priority to EP85115654A priority patent/EP0187287B1/en
Priority to DE8585115654T priority patent/DE3576549D1/en
Priority to KR1019850009280A priority patent/KR890003951B1/en
Publication of JPS61138823A publication Critical patent/JPS61138823A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B1/00—Engines characterised by fuel-air mixture compression
    • F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
    • F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into 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
    • 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)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

PURPOSE:To make an insertion hole for a spark plug installable in position between two exhaust ports in an inclinatory manner, by forming these two exhaust ports a cylinder head so as to be bulged to both sides in the vicinity of an opening part at the combustion chamber side. CONSTITUTION:In order to avoid any interference with an insertion hole 36, two exhaust ports 18 and 18 are bulged to both sides so as to be mutually separated from opening parts 18a and 18a at the combustion chamber side. And, the insertion hole 36 is made to pass through between the bulged parts 18c and 18c, while downstream parts 18d and 18d are made to come closer again from a spot beyond the insertion hole 36 whereby a plane surface form in these exhaust ports 18 and 18 is made so as to become almost parallelism as a whole. With this constitution, the insertion hole 36 for a spark plug is installable in position between these two exhaust ports 18 and 18 in an inclinatory manner, thus such a four-valve on-overhead cam shaft engine as being simplified in structure and excellent in combustibility and serviceability is secured.

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
とを有する４弁式エンジン、特にこれら゛　　　の弁を
１本の頭上カム軸で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 relates to a four-valve engine having two intake valves and two exhaust valves per cylinder, and particularly to a four-valve engine having two intake valves and two exhaust valves per cylinder. This invention relates to a four-valve engine driven by a camshaft.

（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弁式のエンジンが実用
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ｍ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。しかし、この２
ｇｉ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＾く付く難点がある。(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 exhaust efficiency are improved, and the combustion condition is improved.
High engine output is achieved. 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 hinders high engine speed is reduced, making it possible to increase the engine speed. However, these two
The GI upper camshaft engine has a disadvantage in that it has a significantly more complicated structure and is therefore more expensive.

そこで、高出力は必要とするが、特に６回転を要しない
エンジンの場合には、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ｌｌｉ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が、このエンジンの
場合、点火プラグを着火性とサービス性との関係でどの
ように配置するかの問題がある。つまり、１気筒につい
て吸、排気弁を各２個備える場合、良好な着火性を得る
ためには、燃焼室に対して四角形状に配置した４個の弁
の中央部に点火プラグを配置することが必要であるが、
カム軸が１本の場合は、該カム軸が燃焼室の中央部上方
を通過するので、点火プラグの直上方にカム軸が位置す
ることになる。そのため、該カム軸が点火プラグの取付
は取外しの邪魔となってエンジンのサービス性が悪化す
るのである。Therefore, in the case of an engine that requires high output but does not require 6 revolutions, each cylinder is equipped with two intake valves and two exhaust valves, and these valves are driven by one overhead camshaft. Although it is conceivable that the engine can be constructed with a 300mm engine, it is possible to secure the required output and reduce costs, but in the case of this engine, there is a problem in how to arrange the spark plug in relation to ignitability and serviceability. In other words, when each cylinder has two intake and two exhaust valves, in order to obtain good ignition performance, the spark plug should be placed in the center of the four valves arranged in a square shape with respect to the combustion chamber. is necessary, but
If there is only one camshaft, the camshaft passes above the center of the combustion chamber, so the camshaft is located directly above the spark plug. Therefore, the camshaft obstructs the installation and removal of the spark plug, resulting in poor engine serviceability.

４弁１頭上カム軸式エンジンに関する上記のような問題
に対しては、例えば特開昭５７−１０２５０６号公報に
開示されたエンジンがある。このエンジンは、第５，６
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を配設した構
成において、点火プラグ５を２個の排気弁３，３間に傾
斜状に配置することにより、その先端の着火部５ａを燃
焼室１の中央に位置させると共に、その上部５ｂをカム
軸４の側方から斜め上方に臨ませたものである。これに
よれば、良好な着火性が得られ、また点火プラグ５をカ
ム軸４に邪魔されることなく取付は取外しすることが可
能となる。In order to solve the above-mentioned problems regarding the four-valve one-overhead camshaft engine, there is an engine disclosed in, for example, Japanese Patent Application Laid-Open No. 57-102506. This engine is the 5th and 6th
As shown in the figure, two intake valves 2.2 and two exhaust valves 3.3 are arranged in a square shape for one combustion chamber 1, and one cam is arranged above the center of the combustion chamber 1. In the configuration in which the shaft 4 is arranged, the spark plug 5 is arranged in an inclined manner between the two exhaust valves 3, 3, so that the ignition part 5a at the tip thereof is located in the center of the combustion chamber 1, and the upper part of the spark plug 5 is located in the center of the combustion chamber 1. 5b facing diagonally upward from the side of the camshaft 4. According to this, good ignitability can be obtained, and the spark plug 5 can be installed and removed without being obstructed by the camshaft 4.

ところで、上記のように点火プラグを２個の排気弁開に
配置する場合、該プラグの取付はスペースをその両側に
位置する２個の排気ポート間に確保する必要がある。そ
こで、上記公報に開示されたエンジンにおいては、第６
図に示すように２個の排気ポート６．６を燃焼室１側の
開口部５ａ。By the way, when the spark plug is arranged with the two exhaust valves open as described above, it is necessary to secure a space between the two exhaust ports located on both sides of the spark plug for mounting the spark plug. Therefore, in the engine disclosed in the above publication, the sixth
As shown in the figure, the two exhaust ports 6.6 are connected to the opening 5a on the combustion chamber 1 side.

６ａから下流側に向けて次第に離反させて平面形状がハ
状となるように設け、これにより両排気ポート６．６間
に点火プラグ５の取付はスペース７を確保している。そ
して、両排気ポート６．６を離反させることに伴って、
その外側に配置されるヘッドボルト８．８のクランク軸
方向の間隔りが吸気ポート側のヘッドボルト９．９との
間ＷＡＬ’より広くされ、４本のボルト８，８，９．９
の配置がクランク軸方向に長い長方形状とされている。The spark plugs 6 and 6 are gradually separated from each other toward the downstream side from the exhaust ports 6a so as to have a V-shaped planar shape, thereby securing a space 7 for mounting the spark plug 5 between the two exhaust ports 6 and 6. Then, along with separating both exhaust ports 6.6,
The distance between the head bolts 8.8 located on the outside in the crankshaft direction and the head bolts 9.9 on the intake port side is made wider than WAL', and the four bolts 8, 8, 9.9
are arranged in a rectangular shape that is long in the direction of the crankshaft.

しかし、このような構成は、第５，６図に示す皐気筒エ
ンジンの場合には適用できるが、自動車用等として通常
用いられる多気筒エンジンには適用が困難である。つま
り、２個の排気ポートの間隔或いはクランク軸方向に並
ぶヘッドボルトの間隔が広くなると、多気筒エンジンの
場合、隣接気筒間の間隔が大きくなって、エンジン全体
としてクランク軸方向の寸法が著しく長くなり、また該
寸法を短縮しようとすると、排気ポートの通路断面積が
制限されることになる。また、上記のようにヘッドボル
トの配置が長方形状となると、燃焼室の周囲におけるシ
リンダヘッドとシリンダブロックとの間の締付面圧が不
均一となって、燃焼室に対するシール性の悪化を招くこ
とになる。However, although such a configuration can be applied to the case of the single-cylinder engine shown in FIGS. 5 and 6, it is difficult to apply it to a multi-cylinder engine commonly used for automobiles or the like. In other words, when the distance between two exhaust ports or the distance between head bolts aligned in the crankshaft direction increases, in the case of a multi-cylinder engine, the distance between adjacent cylinders increases, and the overall dimension of the engine in the crankshaft direction becomes significantly longer. Moreover, if the dimensions are to be reduced, the passage cross-sectional area of the exhaust port will be limited. In addition, if the head bolts are arranged in a rectangular shape as described above, the tightening surface pressure between the cylinder head and cylinder block around the combustion chamber becomes uneven, leading to deterioration of the sealing performance against the combustion chamber. It turns out.

（発　　明　　の　　目　　的） 本発明は４弁１頭上カム軸式エンジンにおける上記のよ
うな実情に対処するもので、点火プラグをシリンダヘッ
ドにおける２個の排気ポート間に傾斜状に配置すること
により、該プラグの良好な着火性やサービス性を得ると
共に、特に多気筒エンジンの場合に、排気ポートの通路
断面積を十分に確保しながらエンジンのクランク軸方向
寸法が長くならないようにすることを目的とする。(Object of the Invention) The present invention addresses the above-mentioned situation in a four-valve single overhead camshaft engine by arranging the spark plug in an inclined manner between two exhaust ports in the cylinder head. The purpose of this plug is to obtain good ignition performance and serviceability of the plug, and to prevent the engine's crankshaft dimension from increasing while ensuring a sufficient passage cross-sectional area of the exhaust port, especially in the case of a multi-cylinder engine. shall be.

（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個の吸気弁と２個の排気弁とを
備え、これらの弁を１本の頭上カム軸で駆動するように
した構成において、シリンダヘッドにおける２個の排気
ポートを燃焼室側開口部の近傍で両側に膨出するように
屈曲形成すると共に、点火プラグの挿入孔を両排気ポー
トの膨出部間を傾斜状に通過させて先端部が燃焼室の中
央に開口するように設ける。従って、該挿入孔に点火プ
ラグを挿入した時に、該プラグ先端の着火部が燃焼室の
中央に位冒し、且つ上部がシリンダヘッドの側部から斜
め上方を臨むことになる。また、上記挿入孔の両側に位
置する排気ポートが眼孔の通過部においてのみ両側に膨
出されて、全体としては両ポート間の間隔が狭くなる。That is, in a configuration in which one cylinder has two intake valves and two exhaust valves, and these valves are driven by one overhead camshaft, two exhaust ports in the cylinder head are connected to the combustion chamber. It is bent so that it bulges out on both sides near the side opening, and the insertion hole for the spark plug is passed through between the bulges of both exhaust ports in an inclined manner so that the tip opens in the center of the combustion chamber. Provided for. Therefore, when the spark plug is inserted into the insertion hole, the ignition part at the tip of the plug extends to the center of the combustion chamber, and the upper part faces obliquely upward from the side of the cylinder head. Further, the exhaust ports located on both sides of the insertion hole are bulged out on both sides only at the passage through the eye hole, and the distance between the two ports is narrowed as a whole.

そして、これに伴つで燃焼室周囲に配置されるヘッドボ
ルトのクランク軸方向の間隔をこれに直交する方向の間
隔と等しくすることが可能となる。Accordingly, it becomes possible to make the distance between the head bolts disposed around the combustion chamber in the crankshaft direction equal to the distance in the direction perpendicular thereto.

（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、点火プラグの先端の着火部が燃焼室の中央に位置
することにより、良好な着火性ないし火炎の伝播性等が
得られると共に、上記点火プラグの上部がシリンダヘッ
ドの側部から斜め上方を臨むので、カム軸や排気弁の動
弁機構等に邪魔されることなく該点火プラグを取付は取
外しすることが可能となる。これにより、この種のエン
ジンとして、燃焼性及びサービス性に優れたエンジンが
実装される。そして、特に本発明によれば、多気筒エン
ジンの場合において、２個の排気ポート間に点火プラグ
の挿入孔が設けられるにも拘らず、両排気ポートの間の
間隔を狭くすることができるので、排気ポートの通路断
面積を確保しながらエンジン全長の増大を防止すること
ができ、またヘッドボルトを燃焼室の周囲に正方形状に
配置することができるので、燃焼室に対するシール性が
悪化することがない。(Effects of the Invention) According to the above configuration, in a four-valve single overhead camshaft engine, the ignition part at the tip of the spark plug is located in the center of the combustion chamber, resulting in good ignition performance and flame propagation. In addition, since the upper part of the spark plug faces diagonally upward from the side of the cylinder head, the spark plug can be installed or removed without being obstructed by the camshaft or the valve operating mechanism of the exhaust valve. becomes possible. As a result, an engine with excellent combustibility and serviceability is implemented as this type of engine. Particularly, according to the present invention, in the case of a multi-cylinder engine, even though the spark plug insertion hole is provided between the two exhaust ports, the distance between the two exhaust ports can be narrowed. , it is possible to prevent the overall length of the engine from increasing while ensuring the passage cross-sectional area of the exhaust port, and because the head bolts can be arranged in a square shape around the combustion chamber, there is no possibility that the sealing performance against the combustion chamber will deteriorate. There is no.

（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１０は複数のシリン
ダを列状に配置したシリンダブロック１１と、該ブロッ
ク１１の上面にガスケット１２を介して設置されたシリ
ンダヘッド１３とを有し、シリンダブロック１１におけ
るシリンダ１４の内周面と、該シリンダ１４内に嵌合さ
れたピストン１５の上面と、シリンダヘッド１３の上方
に窪まされた下面１３ａとで燃焼室１６が画成されてい
る。また、シリンダヘッド１３には、一方の側面１３ｂ
から上記燃焼室１６に通じる２つの吸気ポート１７．１
７と１．他方の側面１３０から燃焼室１６に通じる２つ
の排気ポート１８．１８とが設けられ、これら各ポート
の燃焼室１６への開口部１７ａ、１７ａ、１８ａ、１８
ａがシリンダヘッド下面１３ａに四角形状に配設されて
いると共に、各開口部１７ａ、１７ａ、１８ａ、１８ａ
を夫々開閉する２個の吸気弁１９．１９と２個の排気弁
２０．２０とが備えられている。そして、これら６弁の
上方に延びるステム部１９ａ、１９ａ、２０ａ、２０ａ
はシリンダヘッド１３の上面１’３ｄ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２
１．２１．２２．２２と、シリンダヘッド１３の上面１
３ｄにおける各ステム部１９ａ　、１９ａ　、２０ａ、
２Ｑａの突出部に形成されたスプリングシート部２３．
２３．２４゜２４との間には、各バルブ１９．１９．２
０．２０を夫々閉方向に付勢するバルブスプリング２５
゜２５．２６．２６が装着されている。As shown in FIG. 1.2, the engine 10 has a cylinder block 11 in which a plurality of cylinders are arranged in a row, and a cylinder head 13 installed on the upper surface of the block 11 via a gasket 12. A combustion chamber 16 is defined by the inner peripheral surface of the cylinder 14 in the block 11, the upper surface of the piston 15 fitted in the cylinder 14, and the lower surface 13a recessed above the cylinder head 13. The cylinder head 13 also has one side surface 13b.
two intake ports 17.1 leading from the combustion chamber 16 to the combustion chamber 16;
7 and 1. Two exhaust ports 18.18 are provided leading from the other side 130 into the combustion chamber 16, each of which has an opening 17a, 17a, 18a, 18 into the combustion chamber 16.
a is arranged in a rectangular shape on the lower surface 13a of the cylinder head, and each opening 17a, 17a, 18a, 18a
Two intake valves 19.19 and two exhaust valves 20.20 are provided, which open and close the intake valves, respectively. Stem portions 19a, 19a, 20a, 20a extending above these six valves
are spring retainers 2 that protrude upward from the upper surface 1'3d of the cylinder head 13 and are fixed to their upper ends, respectively.
1.21.22.22 and the upper surface 1 of the cylinder head 13
Each stem part 19a, 19a, 20a in 3d,
Spring seat portion 23 formed on the protruding portion of 2Qa.
Between 23.24° and 24, each valve 19.19.2
Valve springs 25 each bias 0.20 in the closing direction.
゜25.26.26 is installed.

一方、シリンダヘッド１３の上部中央における上記吸気
弁１９．１９と排気弁２０．２０とに挾まれた位置には
、エンジン１ｏのクランク軸方向に延びる１本のカム軸
２７が配設されている。このカム軸２７のジャーナル部
２７ａ・・・２７ａは、第１図及び第３図に示すように
、シリンダヘッド１３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２８・・・２８と
、各軸受壁２８・・・２８に夫々２本のボルト２９．２
９を用いて固着された軸受キャップ３０・・・３０とで
形成された軸受孔に回転自在に軸承されていると共に、
該カム軸２７における隣接ジャーナル部２７ａ。On the other hand, a single camshaft 27 extending in the direction of the crankshaft of the engine 1o is disposed at the center of the upper part of the cylinder head 13 at a position sandwiched between the intake valve 19.19 and the exhaust valve 20.20. . As shown in FIGS. 1 and 3, the journal portions 27a...27a of the camshaft 27 are provided with bearing walls 28 and 27a, which are provided upright between adjacent cylinders at the center of the upper surface of the cylinder head 13 and at both ends of the head. ...28, and two bolts 29.2 for each bearing wall 28...28.
It is rotatably supported in a bearing hole formed by the bearing caps 30...30 fixed using the bearing caps 9, and
an adjacent journal portion 27a on the camshaft 27;

２７ａｆｍには、１気筒分の２ｇの吸気カム２７ｂ。27afm has a 2g intake cam 27b for one cylinder.

２７ｂと２個の排気カム２７ｃ、２７ｃとが交互に形成
されている。そして、該カム軸２７の上部両側には２本
のロッカーアーム軸３１．３２が平行に架設されている
と共に、これらの軸３１．３２に１気筒について各２個
の吸気弁用ロッカーアーム３３．３３及び排気弁用ロッ
カーアーム３４゜３４が揺動自在に支持され、各ロッカ
ーアーム３３．３３．３４．３４の両端が対応するカム
２７ｂ　、２７ｂ　、２７ｃ　、２７ｃの周面と吸排気
弁のステム部１９ａ　、１９ａ　、２０ａ　、２０ａ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２７の回転によって該ロッカーアーム３
３．３３．３４．３４を介して６弁１９゜１９．２０．
２０が所定のタイミングで開動されるようになっている
。ここで、上記口ツカーアーム＠３１，３２１．１１軸
受キャップ３ｏ・・・３０の上面に押え部材３５・・・
３５を用いて上記ボルト２９・・・２９により固着され
ている。27b and two exhaust cams 27c, 27c are formed alternately. Two rocker arm shafts 31.32 are installed in parallel on both sides of the upper part of the camshaft 27, and two intake valve rocker arms 33.32 for each cylinder are connected to these shafts 31.32. 33 and exhaust valve rocker arms 34 and 34 are swingably supported, and both ends of each rocker arm 33, 33, 34, 34 are connected to the peripheral surfaces of the corresponding cams 27b, 27b, 27c, and 27c and the stem of the intake and exhaust valves. The rocker arm 3 is in contact with the upper ends of the parts 19a, 19a, 20a, and 20a, respectively, so that the rocker arm 3 is rotated by the rotation of the camshaft 27 in synchronization with the crankshaft.
3.33.34.34 through 6 valves 19°19.20.
20 is opened and moved at a predetermined timing. Here, the pressing member 35...
35 and are fixed by the bolts 29...29.

以上の構成に加えて、シリンダヘッド１３には点火プラ
グ挿入孔３６が設けられ、該孔３６内に点火プラグ３７
が装着されている。この挿入孔３６は、第１．２図に示
すように、各気筒における２個の排気ポート１８，１．
８間において排気弁２０．２０に交差するように傾斜状
に設けられ、その先端ＲＢ３６ａがシリンダヘッド１３
の下面１３ａにおける各ポートの開口部１７ａ、１７ａ
、１８ａ、１８ａに囲まれた位置、即ち燃焼室１６の上
部中央に開口されていると共に、眼孔３６の後端部３６
ｂは、シリンダヘッド１３の一側面１３Ｃにおける排気
ポート１８．１８の開口部１８ｂ。In addition to the above configuration, a spark plug insertion hole 36 is provided in the cylinder head 13, and a spark plug 37 is inserted into the hole 36.
is installed. As shown in FIG. 1.2, this insertion hole 36 connects two exhaust ports 18, 1.
RB36a is provided in an inclined manner so as to intersect the exhaust valves 20 and 20 between the cylinder heads 13 and 8.
Openings 17a, 17a of each port on the lower surface 13a of
, 18a, 18a, that is, at the center of the upper part of the combustion chamber 16, and at the rear end 36 of the eye hole 36.
b is the opening 18b of the exhaust port 18.18 on one side 13C of the cylinder head 13;

１８ｂと、該ヘッド１３の上面１３ｄにおける排気弁２
０．２０のスプリングシート部２４．２４との間から該
ヘッド１３の上部外側方を臨むように開口されている。18b, and an exhaust valve 2 on the upper surface 13d of the head 13.
It is opened so as to face the upper outer side of the head 13 from between the spring seat portions 24 and 24 having a diameter of 0.20 mm.

そして、該挿入孔３６の先端部３６ａに続く部分はメネ
ジ部３６ｃとされ、該メネジ部３６Ｃに点火プラグ３７
のオネジ部３７ａを螺合した時に該プラグ先端の着火部
３７ｂが燃焼室１６の上部中火に突出されるようになっ
ている。A portion of the insertion hole 36 following the tip 36a is a female threaded portion 36c, and a spark plug 37 is attached to the female threaded portion 36C.
When the male threaded portion 37a of the plug is screwed together, the ignition portion 37b at the tip of the plug is projected into the upper medium flame of the combustion chamber 16.

然して、この点火プラグ挿入孔３６を排気ポート１８．
１８間に設けるため、該ポート１８．１８は次のような
形状とされている。即ち、第２図に示すように、排気ポ
ート１８．１８を、挿入孔３６との干渉を回ｉ７Ｊるた
めに燃Ｉ２室側開口部１８ａ、１８ａから互いに離反す
るように両側に膨出させ、挿入孔３６をその膨出部１８
ｃ、１８Ｃ間を通過させると共に、両ポート１８．１８
の挿入孔３６を越えた箇所より下流部１８６．１８（１
を再び接近させ、両ポート１８．１８の平面形状が全体
としては略平行となるように形成されている。そして、
両ポート１８．１８の下流部１８ｄ。Therefore, this spark plug insertion hole 36 is connected to the exhaust port 18.
18, the port 18.18 has the following shape. That is, as shown in FIG. 2, the exhaust ports 18.18 are bulged out to both sides away from the combustion I2 chamber side openings 18a, 18a to avoid interference with the insertion hole 36, The insertion hole 36 is inserted into the swollen portion 18
c, 18C, and both ports 18.18
The downstream part 186.18 (1
The ports 18 and 18 are brought close to each other again so that the planar shapes of both ports 18 and 18 are generally parallel to each other. and,
Downstream portion 18d of both ports 18.18.

１８ｄを接近させることにより、隣接気筒間における排
気ポート側のヘッドボルト穴３８．３８の間隔を吸気ポ
ート側のヘッドボルト穴３９．３９と同じ間隔にするこ
とを可能とし、全体として燃焼室１６を囲む正方形状に
ヘッドボルト穴３８゜３８．３９．３９を配置している
。18d, it is possible to make the spacing between the head bolt holes 38.38 on the exhaust port side between adjacent cylinders the same as the head bolt holes 39.39 on the intake port side, and the combustion chamber 16 as a whole can be Head bolt holes 38°, 38, 39, and 39 are arranged in a surrounding square shape.

上記の構成によれば、シリンダヘッド１３の上部中央に
配置しに１本のカム軸２７によって１気筒について各２
個備えられた吸気弁１９．１９及び排気弁２０．２０を
駆動するようにしたエンジン１０において、点火プラグ
３７の先端の着火部３７ｂが燃焼室１６の中央に位置す
ることになって、該燃焼室１６内における混合気の着火
や火炎の伝播が良好に行われることになる。これにより
、良好な燃焼状態が得られ、各２個の吸、排気弁１９．
１９．２０．２０を設けたことによる吸排気効率の向上
と相俟って、優れた出力性能と、良好な燃費及び排気性
能等が得られることになる。According to the above configuration, one camshaft 27 is arranged at the center of the upper part of the cylinder head 13, and two camshafts are provided for each cylinder.
In the engine 10 configured to drive the intake valves 19, 19 and exhaust valves 20, 20, which are individually provided, the ignition part 37b at the tip of the spark plug 37 is located in the center of the combustion chamber 16, so that the combustion The ignition of the air-fuel mixture and the propagation of flame within the chamber 16 will be performed satisfactorily. As a result, a good combustion condition is obtained, and each of the two intake and exhaust valves 19.
Coupled with the improvement in intake and exhaust efficiency due to the provision of 19.20.20, excellent output performance, good fuel efficiency, and exhaust performance can be obtained.

また、上記点火プラグ挿入孔３６の後端部３６ｂがシリ
ンダヘッド１３の側面１３Ｃにお【プる排気ポート１８
．１８の後端開口部１８ｂ、１８ｂと排気弁２０．２０
のスプリングシート部２４゜２４との間にＩｆｉ１口さ
れているので、上記点火プラグ３７をシリンダヘッド１
３の当該側部における排気弁用動弁ＩＪ構の外側から該
動弁抵構やカム紬２７に邪魔されることなく、取付は取
外しすることが可能となる。これにより、当該エンジン
１０の優れたサービス性が得られる。Further, the rear end 36b of the spark plug insertion hole 36 connects to the exhaust port 18 which connects to the side surface 13C of the cylinder head 13.
．． 18 rear end openings 18b, 18b and exhaust valve 20.20
Since the spark plug 37 is inserted between the spring seat portion 24 and the spring seat portion 24 of the cylinder head 1,
Attachment and removal can be performed from the outside of the exhaust valve valve IJ structure on the side of No. 3 without being obstructed by the valve train resistance structure or the cam pongee 27. Thereby, excellent serviceability of the engine 10 can be obtained.

そして、特に上記の構成によれば、２個の排気ポート１
８．１８の平面形状が、点火プラグ挿入孔３６が通過す
る部分のみが両側に膨出し、該膨出部１８ｃ、１８ｃの
下流部１８ｄ、１８ｄが再び接近する形状とされている
ので、両ポート１８゜１８間に上記挿入孔３６が設けら
れているにも拘らず、両ポート１８．１８が全体として
互いに接近されている。これにより、多気筒エンジンの
場合において、植接気筒間の間隔を狭くすることが可能
となり、エンジン１０のクランク軸方向の寸法が長くな
ることが防止される。また、両排気ポート１８．１８の
下流８Ｉ！１８ｄ、１８ｄが接近されていることに伴っ
て、その両側に設【プられたヘッドボルト穴３８．３８
の間隔が狭くされ、これに伴って燃焼室１６の周囲のヘ
ッドボルト３８゜３８．３９．３９を正方形状に配置す
ることが可能となり、燃焼室１６に対する良好なシール
性が得られることになる。このようにして、４弁ｌＷＡ
上カム軸エンジンとして、点火プラグによる着火性と該
プラグに対するサービス性とに優れ、しかも多気筒エン
ジンの場合に、全長が短く且つ燃焼室に対する所要のシ
ール性が確保されたエンジンが実現される。In particular, according to the above configuration, two exhaust ports 1
The planar shape of 8.18 is such that only the portion through which the spark plug insertion hole 36 passes bulges out on both sides, and the downstream portions 18d, 18d of the bulged portions 18c, 18c approach each other again. Although the insertion hole 36 is located between 18 degrees 18, both ports 18, 18 are generally close to each other. Thereby, in the case of a multi-cylinder engine, it becomes possible to narrow the interval between the implanted cylinders, and the dimension of the engine 10 in the crankshaft direction is prevented from increasing. Also, downstream 8I of both exhaust ports 18.18! Since 18d and 18d are close together, the head bolt holes 38 and 38 are set on both sides.
The spacing between the head bolts 38, 39, and 39 around the combustion chamber 16 can be narrowed, and the head bolts 38, 38, 39, 39 around the combustion chamber 16 can be arranged in a square shape, and good sealing performance against the combustion chamber 16 can be obtained. . In this way, the 4-valve lWA
As an upper camshaft engine, it is possible to realize an engine that has excellent ignition performance using a spark plug and serviceability for the plug, and, in the case of a multi-cylinder engine, has a short overall length and ensures the required sealing performance for the combustion chamber.

尚、第４図は本発明の他の実施例を示すもので、この実
施例においては、シリンダヘッド１３′における２個の
排気ポート１８’、１８’の下流部１８ｄ’、１８ｄ’
　が合流され、該ヘッド１３′の側面１３０′に１個の
開口部１８ｂ′として開口されている。しかし、この実
施例においても、点火プラグ挿入孔３６′が２個の排気
ポート１８’、１８’　の分岐している部分の門に傾斜
状に配設されて、該挿入孔３６′の先端部３６８′が燃
焼室１６′の中央に開口されていると共に、両ポート１
８’　、１８’の燃焼室側開口部１８ａ’。Note that FIG. 4 shows another embodiment of the present invention, and in this embodiment, two exhaust ports 18', 18' downstream of the cylinder head 13', 18d', 18d'
are merged into one opening 18b' in the side surface 130' of the head 13'. However, also in this embodiment, the spark plug insertion hole 36' is arranged in an inclined manner at the gate of the part where the two exhaust ports 18', 18' diverge, and the tip of the insertion hole 36'368' is opened in the center of the combustion chamber 16', and both ports 1
8', 18' combustion chamber side opening 18a'.

１８８′に続く部分が両側に膨出されて、その膨出部１
８ｃ’　、１８ａ’間を上記挿入孔３６′が通過してい
る。従って、この実施例によっても、前記実施例と同様
に点火プラグの優れた着火性とサービス性とが得られる
と共に、エンジンの全長が長くなることがなく、またヘ
ッドボルト穴３８’　、３８’　、３９’　、３９’を
正方形状に配置することができて、燃焼室１６′に対す
る所要のシール性が確保される。The part following 188' is bulged out on both sides, and the bulged part 1
The insertion hole 36' passes between 8c' and 18a'. Therefore, this embodiment also provides excellent ignition performance and serviceability of the spark plug as in the previous embodiment, and the overall length of the engine is not increased, and the head bolt holes 38', 38', 39', 39' can be arranged in a square shape, ensuring the required sealing performance for the combustion chamber 16'.

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

第１〜３図は本発明の１丈施例を示すもので、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■−■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
である。第４図は本発明の他の実施例を示すシリンダヘ
ッド単体の横断平面図である。第５．６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。 １３．１３’　・・・シリンダヘッド、１６．１６’・
・・燃焼室、１８．１８’・・・排気ポート、１８ａ。 １８ａ’−・・開口部、１８ｃ、１８ｃ’　・・・膨出
部、１９・・・吸気弁、２０・・・排気弁、２７・・・
カム軸、３６．３６’・・・挿入孔、３６ａ、３６８′
・・・先端部、３７・・・点火プラグ。Figures 1 to 3 show one embodiment 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 the line shown in Figure 1 - ■. FIG. 3 is a cross-sectional plan view of the single cylinder head cut at , and FIG. 3 is a plan view of the valve mechanism. FIG. 4 is a cross-sectional plan view of a single cylinder head showing another embodiment of the present invention. FIG. 5.6 is a longitudinal sectional front view and a lateral plan view of a cylinder head and its surroundings, showing a conventional example. 13.13'...Cylinder head, 16.16'.
...Combustion chamber, 18.18'...Exhaust port, 18a. 18a'--Opening part, 18c, 18c'-Bulging part, 19-Intake valve, 20-Exhaust valve, 27-
Camshaft, 36.36'...Insertion hole, 36a, 368'
...Tip, 37...Spark plug.

Claims (1)

【特許請求の範囲】[Claims] （１）１気筒について２個の吸気弁と２個の排気弁とを
備え、これらの弁を１本の頭上カム軸で駆動するように
した４弁式エンジンにおいて、シリンダヘッドにおける
２個の排気ポートを燃焼室側開口部の近傍で両側に膨出
するように屈曲形成すると共に、点火プラグの挿入孔を
両排気ポートの上記膨出部間を傾斜状に通過させて先端
部が燃焼室の中央に開口するように設けたことを特徴と
する４弁式エンジン。(1) In a four-valve engine in which each cylinder has two intake valves and two exhaust valves, and these valves are driven by one overhead camshaft, two exhaust valves in the cylinder head The ports are bent so as to bulge out on both sides near the opening on the combustion chamber side, and the spark plug insertion hole is passed in an inclined manner between the bulges of both exhaust ports so that the tip end is in the combustion chamber side. A four-valve engine characterized by an opening in the center.
JP59261337A 1984-12-10 1984-12-10 Four-valve type engine Pending JPS61138823A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP59261337A JPS61138823A (en) 1984-12-10 1984-12-10 Four-valve type engine
US06/804,839 US4741302A (en) 1984-12-10 1985-12-05 Internal combustion engine
EP85115654A EP0187287B1 (en) 1984-12-10 1985-12-09 Internal combustion engine
DE8585115654T DE3576549D1 (en) 1984-12-10 1985-12-09 INTERNAL COMBUSTION ENGINE.
KR1019850009280A KR890003951B1 (en) 1984-12-10 1985-12-10 4-valve type engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59261337A JPS61138823A (en) 1984-12-10 1984-12-10 Four-valve type engine

Publications (1)

Publication Number Publication Date
JPS61138823A true JPS61138823A (en) 1986-06-26

Family

ID=17360418

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59261337A Pending JPS61138823A (en) 1984-12-10 1984-12-10 Four-valve type engine

Country Status (1)

Country Link
JP (1) JPS61138823A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0414747U (en) * 1990-05-23 1992-02-06
JPH057200U (en) * 1991-07-16 1993-02-02 難波プレス工業株式会社 Cover material for vehicle seat cushions

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56167805A (en) * 1980-05-28 1981-12-23 Yamaha Motor Co Ltd Cylinder head of 4-valve/1-head cam shaft type engine

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56167805A (en) * 1980-05-28 1981-12-23 Yamaha Motor Co Ltd Cylinder head of 4-valve/1-head cam shaft type engine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0414747U (en) * 1990-05-23 1992-02-06
JPH057200U (en) * 1991-07-16 1993-02-02 難波プレス工業株式会社 Cover material for vehicle seat cushions

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