JPS6248906A - Overhead cam type engine - Google Patents

Abstract

PURPOSE:To form a compact tappet mechanism with a small number of parts by slanting valve stems of intake and exhaust valves with each other towards the center of an overhead cam and driving these valves directly by means of a single cam. CONSTITUTION:Axes A of valve stems 4a, 5a for an intake valve 4 and an exhaust valve 5 are slanted in such a manner as they coincide with the center O of a single cam shaft 6 provided over the heads of and in the medium position between said both valves. A cam for the intake valve and a cam for the exhaust valve provided on the cam shaft 6 in a row, open and close respective valves 4, 5 through valve lifters 10. Thus, since the intake valve 4 and the exhaust valve 5 are driven directly by means of a cam of one cam phase 6 without use of a locker arm and the like, the number of parts is lessened and a lateral projecting part is eliminated, thereby forming a compact tappet valve mechanism.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、シリンダヘッドに吸気弁と排気弁と更に共通
１本の動弁カム軸とを備える所謂シンクルオーバへラド
カム型エンジンに関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a so-called sinkle-over Rad cam type engine, which includes an intake valve, an exhaust valve, and a common valve operating camshaft in a cylinder head.

（従来の技術） 従来、ｆ４ｃ１図に示すような、吸気弁ａと排気弁ｂＩ
！：を動弁カム＋ＭＯ？挟んでその径方向前後に配置し
て成るシングルオーバへラドカム型エンジンは特開昭５
９−９３９２１号公報等によシ知られ、この場合、該吸
気弁ａのステム部と該排気弁すのステム部とは該各ステ
ム部の端部が該動弁カム軸０の径方向前後の互に離間す
る方向に傾斜して設けられ、該各ステム部の端面に一端
が当接するシーン形やスイング形の各ロッカアームｄｉ
介して該吸気弁ａと該排気弁すとに該動弁カム軸０によ
る開弁作動が与えられるようにするを一般とする。(Prior art) Conventionally, an intake valve a and an exhaust valve bI as shown in Fig. f4c1 are used.
! : Valve train cam + MO? The single-over Radcam type engine, which is sandwiched and arranged radially front and rear, was developed in Japanese Patent Application Publication No. 5.
9-93921, etc., and in this case, the stem portion of the intake valve a and the stem portion of the exhaust valve a are such that the end portions of each stem portion are radially front and rear of the valve drive camshaft 0. Each of the scene-type and swing-type rocker arms DI is provided to be inclined in a direction away from each other, and one end abuts the end surface of each stem portion.
Generally, the valve-operating camshaft 0 provides a valve-opening operation to the intake valve a and the exhaust valve.

（発明が解決しようとする問題点） 上記従来のものにあっては、ロッカアームｄやロッカア
ームシャ７）ｅ等が必要で比較的部品点数が増加し勝ち
であυ、又ロッカアームｄやロッカアームシャフトｅの
配置スペースの確保及び各ステム部をその各端部が動弁
カム軸０の径方向前後の互に離間する方向に傾斜させて
設けることからシリンダヘッドが比較的大型化する問題
がある。(Problems to be Solved by the Invention) The above-mentioned conventional device requires a rocker arm d, a rocker arm shaft 7)e, etc., and the number of parts is relatively increased. There is a problem in that the cylinder head becomes relatively large because of the securing of the arrangement space and the fact that each stem portion is provided so that each end thereof is inclined in a direction that is spaced apart from each other in the radial direction of the valve drive camshaft 0.

ところで、吸気弁のステム部の上側と排気弁のステム部
の上側とに動弁カム軸を１対に配直しロッカアームを省
略し得るようにした所謂ダブルオーバヘッドカム型エン
ジンはあるが、この場合も動弁カム軸を１対に設けるこ
とから部品点数が増加し、又シリンダヘッドも比較的大
型化し勝ちである。By the way, there is a so-called double overhead cam type engine in which the valve drive camshafts are arranged in a pair above the intake valve stem and above the exhaust valve stem so that the rocker arm can be omitted. Since a pair of valve drive camshafts are provided, the number of parts increases, and the cylinder head also becomes relatively large.

本発明は、かかる問題点を解決したオーバヘッドカム型
エンジンを提供することをその目的とする。An object of the present invention is to provide an overhead cam type engine that solves these problems.

（問題点を解決するための手段） 本発明は、かかる目的を達成すべく、シリンダヘッドに
吸気弁と排気弁と更に共通１本の動弁カム軸とを備える
オーバヘッドカム型エンジンであって、該吸気弁と該排
気弁とを該動弁カム軸を挟んでその径方向前後に配置し
て成るものにおいて、該吸気弁のステム部と該排気弁の
ステム部とを該各ステム部の軸線が該動弁カム軸の各カ
ム部のベース円中心を通るように傾斜させて設け、該各
ステム部の端面全該各カム部にパルプリフタを介して当
接させたことを特徴とする。(Means for Solving the Problems) In order to achieve the above object, the present invention provides an overhead cam type engine that includes an intake valve, an exhaust valve, and a common valve-driving camshaft in a cylinder head, The intake valve and the exhaust valve are arranged radially forward and backward with the valve drive camshaft in between, and the stem portion of the intake valve and the stem portion of the exhaust valve are aligned with the axis of each stem portion. is inclined so as to pass through the center of the base circle of each cam portion of the valve operating camshaft, and the entire end face of each stem portion is brought into contact with each cam portion via a pulp lifter.

（実施例） 本発明全図示の実施例につき説明する。(Example) A fully illustrated embodiment of the present invention will be described.

図面で１１）はシリンダ、（２）はその上側のシリンダ
ヘラドラ示し、該シリンダ（１）内にピストン（３）ト
、該シリンダヘッド（２）に吸気弁（４）の１対と排気
弁（５）と更に共通１本の動弁カム軸（６）とを設け３
弁型のシングルオーバへラドカム型エンジンを構成し、
該吸気弁（４）　（４１と該排気弁（５）とを該動弁カ
ム軸（６）を挟んでその径方向前後に配置すると共に、
該シリンダヘッド（２）の該吸気弁Ｔ４１　＋４１の配
置側に１対の吸気ボー）　＋７１　（７１と該排気弁（
５）の配置側に排気ビート（８）と′５ｅ開設しクロス
７０−型に構成した。In the drawing, 11) is a cylinder, (2) is a cylinder spatula on the upper side, a piston (3) is installed in the cylinder (1), and a pair of intake valves (4) and an exhaust valve are installed in the cylinder head (2). (5) and one common valve camshaft (6) are provided.
Constructs a valve type single over Radcam type engine,
The intake valve (4) (41) and the exhaust valve (5) are arranged in front and behind the valve drive camshaft (6) in the radial direction, and
+71 (a pair of intake bows on the side where the intake valve T41 +41 of the cylinder head (2) is arranged) +71 (71 and the exhaust valve (
The exhaust beat (8) and '5e were opened on the side where 5) was placed, and it was configured in a cross 70-type.

図面で（９）は両吸気弁＋４１　ｆ４）間に位置させて
シリンダヘッド（２］に設けた点大プラグを示す。In the drawing, (9) shows a large dot plug located in the cylinder head (2) between both intake valves (+41 f4).

ここで本発明によれば、吸気弁（４）のステム部（４ａ
）と排気弁（５）のステム部（５ａ）とｔｉ各ステム部
（４ａ）　（５ａ）の軸線Ａが動弁カム軸（６）の各カ
ム部（６＆）のベース円中心０を通るように傾斜させて
設け、該各ステム部（４ａ）　（５ａ）の端面（４’ｂ
）　（５ｂ）を該各カム部（６＆）にパルプリフタαＱ
を介して当接させるもので、これを詳述するに図示のも
のでは、該動弁カム軸（６）の軸線に対する該両吸気弁
（４１（４１と該排気弁（５）との該動弁カム軸（６）
の径方向前後へのオフセットｕｔ同一にし、シリンダ（
１）の軸線に対する該各吸気弁（４）のステム部（４ａ
）と該排気弁（５）のステム部（５＆）との傾斜角が同
一となるようにした。又、該各パルプリフタα１は円筒
キャップ状に形成され、これをシリンダヘッド（２）に
形成したガイド孔任υに摺動自在に嵌挿し、該各パルブ
リ７りα〔の頂部をその内面において該各ステム部（４
ａ）　（５ｍ）の各端面（４ｂ）（５ｂ）とその外面に
おいて該各カム部（６＆）とに当接させるようにした。According to the present invention, the stem portion (4a) of the intake valve (4)
), the stem part (5a) of the exhaust valve (5), and the axis A of each stem part (4a) (5a) of the exhaust valve (5), so that it passes through the base circle center 0 of each cam part (6 &) of the valve drive camshaft (6). The end face (4'b) of each stem part (4a) (5a)
) (5b) to each cam part (6&) with pulp lifter αQ
To explain this in detail, in the illustrated example, the movement of both intake valves (41 (41 and exhaust valve (5)) with respect to the axis of the valve drive camshaft (6) Valve cam shaft (6)
The offset ut in the radial direction is the same, and the cylinder (
The stem portion (4a) of each intake valve (4) with respect to the axis of
) and the stem portion (5&) of the exhaust valve (5) are made to have the same inclination angle. Further, each pulp lifter α1 is formed in the shape of a cylindrical cap, which is slidably inserted into a guide hole formed in the cylinder head (2), and the top of each pulp lifter α Each stem part (4
a) Each end face (4b) (5b) of (5m) and its outer surface were brought into contact with each of the cam parts (6&).

図面でα２はパルプクリアランス調節用シム、α３は各
吸気弁（４）及び排気弁（５）ヲ夫々閉じ側に付勢する
パルプスプリング、ａ４１はパルプガイド、０りは各ガ
イド孔αＤ内への空気の閉込み防止とオイルを抜く透孔
、ａＧは動弁カム軸（６］の端部に固定のスプロケット
、住ηはカムカバ全示す。In the drawing, α2 is a shim for adjusting pulp clearance, α3 is a pulp spring that biases each intake valve (4) and exhaust valve (5) toward the closing side, a41 is a pulp guide, and 0 is a shim for each guide hole αD. Through hole for preventing air entrapment and draining oil, aG shows the sprocket fixed to the end of the valve train camshaft (6), and η shows the cam cover in its entirety.

（作用） 吸気弁（４）のステム部（４ａ）と排気弁（５）のステ
ム部（５ａ）とを該各ステ五部（４ｍ）　（５ａ）の軸
線Ａが動弁カム軸（６）の各カム部（６ａ）のベース円
中心０を通るように傾斜させて設け、該各ステム部（４
＆）（５ａ）の端面（４ｂ）　（５ｂ）　’ｉ該各カム
部（６ａ）にパルプリフタαｌｔ−介して当接させるこ
とによシ、ロッカアームやロッカアームシャフトが不要
となシ、又ロッカアームやロッカアームシャフトの配置
スペースが不要で、而も吸気弁（４）のステム部（４＆
）と排気弁（５）との各ステム部（４ａ）（５ａ）の各
端部が動弁カム軸（６）の径方向前後の互に離間する方
向に傾斜せず逆に狭まる方向に傾斜していることからシ
リンダヘッド（２）が非常にコンパクトになる。(Function) The stem part (4a) of the intake valve (4) and the stem part (5a) of the exhaust valve (5) are connected to each other when the axis A of each stem part (4m) (5a) is the valve drive camshaft (6). The cam portions (6a) of each cam portion (6a) are inclined so as to pass through the center 0 of the base circle,
&) By bringing the end face (4b) of (5a) into contact with each cam part (6a) via the pulp lifter αlt-, there is no need for a rocker arm or rocker arm shaft, and the rocker arm or rocker arm No space is required for the shaft, and the stem part (4&
) and the exhaust valve (5), each end of each stem portion (4a) (5a) does not incline in the direction of separating from each other in the radial direction of the valve drive camshaft (6), but on the contrary, inclines in the direction of narrowing. This makes the cylinder head (2) extremely compact.

又、吸気弁（４）をそのステム部（４ａ）の端部がシリ
ンダ（１）の中心側に傾斜するように配置することによ
シ、第４図に明示するように吸気ボート（７）の軸線の
該シリンダ（１）の軸線に対する傾斜角が小ごくなる、
即ち吸気ボート（７）の曲りが少なくなるような配置が
可能となる。Furthermore, by arranging the intake valve (4) so that the end of its stem portion (4a) is inclined toward the center of the cylinder (1), the intake boat (7) can be opened as clearly shown in FIG. the angle of inclination of the axis of the cylinder (1) with respect to the axis of the cylinder (1) becomes smaller;
In other words, it is possible to arrange the intake boat (7) so that the bending thereof is reduced.

（発明の効果） このように本発明によれば、共通１本の動弁カム軸を挟
んでその径方向前後に吸気弁と排気弁とを備えるり四ス
フロー型のシングルオーバへラドカム型エンジンの動弁
機構を、各ステム部をその軸線が該動弁カム軸の各カム
部のベース円中心を通るように傾斜させて設けると共に
、該各ステム部の端面を該各カム部にパルブリ７りを介
して当接させるようにした直動式に構成するもので、上
記従来のものに比し部品点数の削減ができ、而もシリン
ダヘッドの小型化を図ることができ、又吸気弁と排気弁
との各ステム部の各端部が動弁カム軸の径方向前後の互
に狭まる方向に傾斜していることから、曲りの少ない吸
気ボートのレイアウトが可能となる効果を有する。(Effects of the Invention) According to the present invention, an intake valve and an exhaust valve are provided at the front and rear in the radial direction across a common valve camshaft, and a four-flow type single-over Radcam type engine is equipped with The valve mechanism is provided such that each stem portion is inclined so that its axis passes through the center of the base circle of each cam portion of the valve camshaft, and the end face of each stem portion is provided with a valve 7 on each cam portion. It is configured as a direct-acting type that contacts through Since each end of each stem portion connected to the valve is inclined in a direction in which the front and back narrow in the radial direction of the valve operating camshaft, it is possible to layout the intake boat with less curvature.

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

第１図は従来例の説明線図、第２図は本発明エンジンの
１例の平面図、第５図及び第４図は夫々第１図のＩ−１
線及びＩＶ−ＩＶ線截斯側面図、第５図は第３図のｖ−
Ｙ線截断正面図、第６図は第４図の■−■線截断正面図
である。 （２）・・・シリンダヘッド　　　（４）・・・吸気弁
（４＆）・・・吸気弁のステム部　（４ｂ）・・・端面
（５）・・・排気弁　　　　　（５１）・・・排気弁の
ステム部（５ｂ）・・・端面　　　　（６）・・・動弁
カム軸（６ａ）・・・カム部　　　α１・・・パルブリ
７りＡ・・・ステム部の軸線 ０・・・ペース円中心FIG. 1 is an explanatory diagram of a conventional example, FIG. 2 is a plan view of an example of the engine of the present invention, and FIGS. 5 and 4 are I-1 in FIG. 1, respectively.
Sectional side view taken along line and IV-IV; FIG.
FIG. 6 is a front view taken along the line ■--■ in FIG. 4. (2)...Cylinder head (4)...Intake valve (4&)...Intake valve stem (4b)...End face (5)...Exhaust valve (51)...Exhaust valve Stem part (5b)...End face (6)...Valve train camshaft (6a)...Cam part α1...Palburi 7riA...Axis of stem part 0...Center of pace circle

Claims (1)

【特許請求の範囲】[Claims] シリンダヘッドに吸気弁と排気弁と更に共通１本の動弁
カム軸とを備えるオーバヘッドカム型エンジンであって
、該吸気弁と該排気弁とを該動弁カム軸を挟んでその径
方向前後に配置して成るものにおいて、該吸気弁のステ
ム部と該排気弁のステム部とを該各ステム部の軸線が該
動弁カム軸の各カム部のベース円中心を通るように傾斜
させて設け、該各ステム部の端面を該各カム部にバルブ
リフタを介して当接させたことを特徴とするオーバヘッ
ドカム型エンジン。An overhead cam type engine that includes an intake valve, an exhaust valve, and a common valve camshaft in a cylinder head, and the intake valve and the exhaust valve are arranged in front and rear in a radial direction with the valve camshaft in between. in which the stem portion of the intake valve and the stem portion of the exhaust valve are inclined so that the axis of each stem portion passes through the center of the base circle of each cam portion of the valve drive camshaft. An overhead cam type engine, characterized in that an end face of each of the stem portions is brought into contact with each of the cam portions via a valve lifter.