JPH0375724B2 - - Google Patents
Info
- Publication number
- JPH0375724B2 JPH0375724B2 JP61161737A JP16173786A JPH0375724B2 JP H0375724 B2 JPH0375724 B2 JP H0375724B2 JP 61161737 A JP61161737 A JP 61161737A JP 16173786 A JP16173786 A JP 16173786A JP H0375724 B2 JPH0375724 B2 JP H0375724B2
- Authority
- JP
- Japan
- Prior art keywords
- rocker arm
- wear
- bearing
- resistant piece
- mold
- 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.)
- Expired - Lifetime
Links
Landscapes
- Valve-Gear Or Valve Arrangements (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、内燃機関の頭上カム軸式動弁機構で
使用するAl合金製ロツカアームをダイカスト法
により得る方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for obtaining an Al alloy rocker arm for use in an overhead camshaft valve mechanism of an internal combustion engine by die casting.
従来技術
内燃機関用構造部材においては、軽合金材料の
採用によつて積極的に軽量化が進められており、
ロツカアームの如き運動部品を軽合金材で形成す
ることは、慣性力を低減化する意味でも効果的で
ある。特に、高速機関に好適な頭上カム軸式動弁
機構で使用されるロツカアームを軽合金材で形成
するのは有効である。Prior Art In structural members for internal combustion engines, efforts are being made to reduce weight by adopting light alloy materials.
Forming moving parts such as the rocker arm from a light alloy material is also effective in reducing inertial force. In particular, it is effective to form the rocker arm used in an overhead camshaft type valve mechanism suitable for high-speed engines from a light alloy material.
第１図は、特開昭60−121237号公報に示された
一例としてのAl合金製ロツカアーム01を示して
いる。このロツカアーム01は、特開昭60−121237
号公報に示すように、ダイガスト法によつて得た
ものであり、その中央部にロツカアーム軸と嵌合
するロツカアーム軸孔03（ダイカスト品の穿孔に
より形成）が形成された厚肉の軸受部02を有する
とともに、腕04の端部に弁駆動カムと摺接する耐
摩耗部片05（鉄系焼結材、セラミツクス等で形成）
が鋳包みにより一体化され、腕06の端部にバル
ブ・クリアランス調整螺子用螺子孔07が形成され
ている。 FIG. 1 shows an Al alloy rocker arm 01 as an example disclosed in Japanese Patent Laid-Open No. 121237/1983. This Rotsuka Arm 01 is published in Japanese Patent Publication No. 60-121237.
As shown in the publication, the thick-walled bearing part 02 is obtained by the die-casting method and has a rocker arm shaft hole 03 (formed by drilling a die-cast product) formed in the center thereof to fit the rocker arm shaft. and a wear-resistant piece 05 (made of iron-based sintered material, ceramics, etc.) that slides into contact with the valve drive cam at the end of arm 04.
are integrated by casting, and a screw hole 07 for a valve clearance adjustment screw is formed at the end of the arm 06.
解決しようとする課題
しかるに、前記特開昭60−121237号に記載のよ
うな製造方法で製造されたロツカアーム01では、
軸受部02は、繰り返し作用する大きな応力に耐え
得るように、これを厚肉に形成しなければなら
ず、その内部に多孔性の鋳巣が生ずる可能性があ
る。Problems to be Solved However, in the Rotsuka Arm 01 manufactured by the manufacturing method described in JP-A No. 60-121237,
The bearing part 02 must be formed thick so that it can withstand the large stress that is applied repeatedly, and there is a possibility that porous cavities will be formed inside the bearing part 02.
また特開昭57−97861号公報には、ロツカアー
ムの厚肉軸受部の鋳巣発生を防止するために、キ
ヤビテイ内に注入された溶湯が凝固する前に加圧
棒たる加圧ピンをキヤビテイ内に突出させて、二
次加圧力を加えるようになつていたが、突起を有
する耐摩耗部片を鋳包む場合に、軸受部の中心に
向けて溶湯を注入すると、複雑な形状をした耐摩
耗部片の鋳包み部に溶湯が充分に到達することが
できず、密着性の良好な鋳包み構造が得られない
のみならず、該耐摩耗部片が位置ずれを起す惧れ
があつた。 Furthermore, in Japanese Patent Application Laid-Open No. 57-97861, in order to prevent the formation of cavities in the thick-walled bearing part of the rocker arm, a pressure pin as a pressure rod is inserted into the cavity before the molten metal injected into the cavity solidifies. However, when casting a wear-resistant piece with protrusions, injecting molten metal toward the center of the bearing part causes the wear-resistant piece to have a complex shape. The molten metal could not sufficiently reach the cast-in portion of the piece, and not only was it impossible to obtain a cast-in structure with good adhesion, but there was also a risk that the wear-resistant piece would become misaligned.
課題を解決するための手段および作用効果
本発明はこのような難点を克服したAl合金製
ロツカアームの製造方法の改良に係り、内燃機関
の頭上カム軸式動弁機構で使用するAl合金製ロ
ツカアームのダイカスト法による製造方法であつ
て、ロツカアーム軸と嵌合する厚肉の軸受部を有
するとともに、裏面に突起のあるカム摺接用耐摩
耗部片を一体に具備するロツカアームの製造方法
において、その型孔内に設置される前記耐摩耗部
片の裏面に向けて湯口を形成したロツカアーム用
金型を用い、耐摩耗部片に向けて加圧注湯を行な
つた後、溶湯が凝固する直前に、前記軸受部に対
し、外径ｄ＝0.17D〜0.60D（ただし、Ｄは軸受部
外径である）なる加圧棒を用いて、仮想ロツカア
ーム軸中心線方向の二次加圧力を作用させ、得ら
れた鋳造品の軸受部に、内径ｒ≧ｄ＋６mmなるロ
ツカアーム軸孔を穿孔形成することを特徴とする
ものである。Means and Effects for Solving the Problems The present invention relates to an improvement of a method for manufacturing an Al alloy rocker arm that overcomes the above-mentioned difficulties, and is directed to improving a manufacturing method of an Al alloy rocker arm used in an overhead camshaft type valve mechanism of an internal combustion engine. In a method of manufacturing a rocker arm using a die casting method, the rocker arm has a thick bearing part that fits into the rocker arm shaft and is integrally equipped with a wear-resistant piece for cam sliding contact with a protrusion on the back surface. After pouring the molten metal under pressure toward the wear-resistant piece using a rocker arm mold with a sprue formed on the back side of the wear-resistant piece installed in the hole, immediately before the molten metal solidifies, Applying a secondary pressure force in the direction of the virtual rocker arm axis center line to the bearing part using a pressure rod having an outer diameter d = 0.17D to 0.60D (where D is the outer diameter of the bearing part), This method is characterized in that a rocker arm shaft hole with an inner diameter of r≧d+6 mm is formed in the bearing portion of the obtained cast product.
本発明は前記したように前記耐摩耗部片の裏面
に向けて湯口を形成したロツカアーム用金型を用
い、耐摩耗部片に向けて加圧注湯を行なうように
したため、該耐摩耗部片を迂回するとなく湯口か
ら鋳包み部に溶湯を直接給湯することができ、そ
の結果、密着性の良好な鋳包み部を得ることがで
き、しかも高圧による注湯であつても、金型に対
して該耐摩耗部片を押付ける押付け力を作用させ
るので、該耐摩耗部片の位置ずれを未然に防止す
ることができる。 As described above, the present invention uses a rocker arm mold in which a sprue is formed toward the back surface of the wear-resistant piece, and pours the metal under pressure toward the wear-resistant piece. Molten metal can be directly supplied from the sprue to the cast-in part without detouring, and as a result, a cast-in part with good adhesion can be obtained.Moreover, even when pouring under high pressure, there is no contact with the mold. Since a pressing force is applied to press the wear-resistant piece, displacement of the wear-resistant piece can be prevented.
また本発明においては、前記ロツカアーム用金
型内への加圧注湯を行なつた後、溶湯が凝固する
直前に、前記軸受部に対し、ｄ＝0.17D〜0.60D
（Ｄはロツカアーム軸受部外径）の外径の加圧棒
を用いて、仮想ロツカアーム軸中心線方向の二次
加圧力を作用させたため、耐摩耗部片に向けて加
圧注湯することでもつてより一層鋳巣の発生し易
い軸受部での鋳巣の発生を未然に阻止することが
できるとともに、ロツカアーム特にその軸受部で
の結晶組織を均一化するとともに、微細化するこ
とができ、しかも大幅な強度向上を図ることがで
き、かつ優れた耐摩耗性を確保することができ
る。 Further, in the present invention, after pressure pouring into the rocker arm mold and immediately before the molten metal solidifies, d=0.17D to 0.60D is applied to the bearing portion.
(D is the outer diameter of the rocker arm bearing part) A pressure rod with an outer diameter of the rocker arm bearing was used to apply a secondary pressure force in the direction of the virtual rocker arm shaft center line, so pouring under pressure toward the wear-resistant parts also caused It is possible to prevent the formation of blowholes in the bearing part, where blowholes are more likely to occur, and the crystal structure of the rocker arm, especially in the bearing part, can be made uniform and finer. It is possible to improve the strength and ensure excellent wear resistance.
さらに本発明では、前記した二次加圧力を作用
させて得られたロツカアームの軸受部に、内径ｒ
＝ｄ＋６mmなるロツカアームの軸孔を形成するこ
とにより、前記二次加圧力の作用でもつて発生す
る湯皺等の異常組織部分を除去して、ロツカアー
ム軸孔の周辺孔壁を健全な組織部分にすることが
できる。 Furthermore, in the present invention, the inner diameter r
By forming the rocker arm shaft hole with = d + 6 mm, abnormal tissue parts such as water wrinkles that occur due to the action of the secondary pressurizing force are removed, and the hole wall around the rocker arm shaft hole is made into a healthy tissue part. be able to.
実施例
以下、本発明方法の一実施例を、第２図ないし
第５図の図面を参照しながら具体的に説明する。Embodiment Hereinafter, an embodiment of the method of the present invention will be specifically described with reference to the drawings of FIGS. 2 to 5.
金型１のロツカアーム用型孔２（キヤビテイ）
内には、その所定位置に、裏面に突起５を備えた
耐摩耗部片４（鉄系焼結材、セラミツクス等で形
成）が設置される。湯口３は、第２図において紙
面に直角な仮想ロツカアーム軸中心線Ｌに対し、
耐摩耗部片４設置位置側に寄つて形成されるとと
もに、該湯口３の向きは、矢印Ａで示すように耐
摩耗部片４の裏面に向かう方向に指向している。 Mold hole 2 (cavity) for rocker arm of mold 1
Inside, a wear-resistant piece 4 (made of iron-based sintered material, ceramics, etc.) having a protrusion 5 on its back surface is installed at a predetermined position. The sprue 3 is aligned with the virtual rocker arm axis center line L perpendicular to the plane of the paper in FIG.
The sprue 3 is formed closer to the wear-resistant piece 4 installation position, and the sprue 3 is oriented toward the back surface of the wear-resistant piece 4 as shown by arrow A.
このように湯口３の向きを耐摩耗部片４の裏面
に向う一定方向に指向させ、耐摩耗部片４に向け
て注湯を行う理由は、注湯圧力を、耐摩耗部片４
を不動に位置決めするための保持力として積極的
に利用するためである。 The reason why the sprue 3 is oriented in a fixed direction toward the back surface of the wear-resistant piece 4 and the molten metal is poured toward the wear-resistant piece 4 is to control the pouring pressure to the wear-resistant piece 4.
This is to actively use it as a holding force for immovably positioning.
また、金型要素１Ａ，１Ｂのうち、一方の金型
要素１Ａの壁部を貫通して、型孔２内に進入し得
る様に、油圧によつて駆動される加圧棒（プラン
ジヤー）６が設けられている。この加圧棒６は、
仮想ロツカアーム軸中心線Ｌ上にあり、該中心線
Ｌに沿つて進退する（第３図参照）。 Also, a pressure rod (plunger) 6 driven by hydraulic pressure so as to penetrate the wall of one of the mold elements 1A and 1B and enter the mold hole 2. is provided. This pressure rod 6 is
It is located on the virtual rocker arm axis center line L, and moves forward and backward along the center line L (see FIG. 3).
かかる構造の金型１を用い、湯口３を通じて型
孔２内にAl合金の加圧注湯（600Kg／cm2）を行う
と、最初の溶湯が耐摩耗部片４の周囲に供給さ
れ、その部分が充たされた後、軸受部を形成する
凹陥部2a側へ向かつて順次溶湯が充たされる。
そして、型孔２が溶湯によつて完全に充たされた
後、該溶湯が凝固する直前に、加圧棒６を前進さ
せ（第３図二点鎖線）、得られるべきロツカアー
ムの厚肉の軸受部に二次加圧力（2500Kg／cm2）を
作用させる。 Using the mold 1 having such a structure, when Al alloy is poured under pressure (600Kg/cm 2 ) into the mold hole 2 through the sprue 3, the first molten metal is supplied around the wear-resistant piece 4, and the area is After the molten metal is filled, the molten metal is sequentially filled toward the concave portion 2a side that forms the bearing portion.
After the mold cavity 2 is completely filled with the molten metal and just before the molten metal solidifies, the pressurizing rod 6 is advanced (double-dotted line in Figure 3) to reduce the thickness of the rocker arm to be obtained. Apply secondary pressure (2500Kg/cm 2 ) to the bearing.
このように軸受部に二次加圧を行う理由は、凝
固の遅れる厚肉部には鋳巣が生じ易いからであ
り、二次加圧によつて加圧棒６の周囲に均一、か
つ微細な結晶組織が得られ、ロツカアーム軸と嵌
合する部分である軸受部に大きな強度を付与する
ことができる。 The reason why secondary pressure is applied to the bearing part in this way is that cavities are likely to form in thick-walled parts where solidification is delayed. It is possible to obtain a crystal structure with a high degree of strength, and it is possible to impart great strength to the bearing part, which is the part that fits with the rocker arm shaft.
しかして、溶湯内に加圧棒６を押込むことによ
る効果は、加圧棒６の外径（d〓mm）によつて異な
り、外径(d)が増大するほど大きな効果を得ること
ができる。この事を確認するために、金型要素
1Bの凹陥部２ａ位置に圧力測定器決Ｂを取付け
（第３図参照）、種々異なる外径(d)の加圧棒６を軸
受部を充たす溶湯内に押し込んで溶湯圧を測定し
たところ、第４図に示す溶湯圧曲線が得られた
（グラフの横軸は、軸受部溶湯の外径（D〓mm）に
対する加圧棒６の外径(d)の比を示す）。 Therefore, the effect of pushing the pressure rod 6 into the molten metal varies depending on the outer diameter (d〓mm) of the pressure rod 6, and the larger the outer diameter (d), the greater the effect. can. To confirm this, the mold element
Pressure measuring device B was attached to the concave portion 2a of 1B (see Figure 3), and the pressure of the molten metal was measured by pushing pressure rods 6 with various outside diameters (d) into the molten metal filling the bearing. A molten metal pressure curve shown in FIG. 4 was obtained (the horizontal axis of the graph indicates the ratio of the outer diameter (d) of the pressure rod 6 to the outer diameter (D mm) of the molten metal in the bearing).
ところで、ｄ／Ｄ＜0.17では、二次加圧による
組織の改善を期待し難いため、ｄ／Ｄ≧0.17なる
条件を満たすように加圧棒６の外径(d)を選択する
ことが望まれる。しかしながら、ｄ／Ｄ＞0.6に
なると、加圧棒６の周囲の加圧による影響範囲が
大きく、凝固時における塑性変形、割れ等が生
じ、好ましくない。 By the way, when d/D<0.17, it is difficult to expect the structure to improve by secondary pressure, so it is desirable to select the outer diameter (d) of the pressure rod 6 so as to satisfy the condition d/D≧0.17. It will be done. However, when d/D>0.6, the area affected by the pressure around the pressure rod 6 is large, causing plastic deformation, cracking, etc. during solidification, which is not preferable.
それ故、本発明では、ｄ＝0.17D〜0.60Dmmを
満たす外径の加圧棒６を採用することとした。 Therefore, in the present invention, the pressure rod 6 having an outer diameter satisfying d=0.17D to 0.60Dmm is adopted.
斯くて、ダイカスト品であるロツカアーム素材
の軸受部を、機械加工により穿孔し、第５図に示
す形状のロツカアーム７を得ることができる。こ
こで問題になるのが、軸受部８にロツカアーム軸
孔９を形成する場合の切除量である。 In this manner, the bearing portion of the rocker arm material, which is a die-cast product, is bored by machining, and the rocker arm 7 having the shape shown in FIG. 5 can be obtained. The problem here is the amount of removal when forming the rocker arm shaft hole 9 in the bearing portion 8.
すなわち、加圧棒６によつてダイカスト品に形
成された有底開孔の内壁から層厚３mm程度の範囲
では、湯皺模様、塑性変形部、割れ等の異常組織
が生ずる傾向があるため、この部分を除去するの
が好ましい。したがつて、ロツカアーム軸孔９の
内径（ｒmm）は、ｒ≧ｄ＋６mmとする必要があ
り、この関係から逆に、加圧棒６の外径(d)は、ｄ
≦ｒ−６mmとなる。 That is, in a range of about 3 mm from the inner wall of the bottomed hole formed in the die-cast product by the pressurizing rod 6, abnormal structures such as wrinkling patterns, plastic deformation parts, and cracks tend to occur. It is preferable to remove this part. Therefore, the inner diameter (rmm) of the rocker arm shaft hole 9 needs to be r≧d+6mm, and from this relationship, conversely, the outer diameter (d) of the pressure rod 6 is d
≦r-6mm.
第１図は公知に係るロツカアーム要部欠截正面
図、第２図は本発明を実施するために用いるロツ
カアーム用金型の要部断面図、第３図は該金型の
全体断面図、第４図はロツカアーム軸受部の外径
(D)に対する二次加圧用加圧棒の外径(d)の比と溶融
圧力との関係を示すグラフ、第５図は製品として
のロツカアームを示す正面図である。
１……金型、２……型孔、２ａ……凹陥部、３
……湯口、４……耐摩耗部片、５……突起、６…
…加圧棒、７……ロツカアーム、８……軸受部、
９……ロツカアーム軸孔。
FIG. 1 is a cutaway front view of the main parts of a known rocker arm, FIG. 2 is a sectional view of the main parts of a mold for a rocker arm used to carry out the present invention, and FIG. 3 is an overall sectional view of the mold. Figure 4 shows the outer diameter of the rocker arm bearing.
A graph showing the relationship between the ratio of the outer diameter (d) of the pressure rod for secondary pressurization to (D) and the melting pressure, and FIG. 5 is a front view showing the rocker arm as a product. 1... Mold, 2... Mold hole, 2a... Concave portion, 3
... Sprue, 4... Wear-resistant piece, 5... Protrusion, 6...
...Pressure rod, 7...Rotsuka arm, 8...Bearing part,
9...Lotsuka arm shaft hole.
Claims (1)
Al合金製ロツカアームのダイカスト法による製
造方法であつて、ロツカアーム軸と嵌合する厚肉
の軸受部を有するとともに、裏面に突起のあるカ
ム摺接用耐摩耗部片を一体に具備するロツカアー
ムの製造方法において、 その型孔内に設置される前記耐摩耗部片の裏面
に向けて湯口を形成したロツカアーム用金型を用
い、耐摩耗部片に向けて加圧注湯を行なつた後、
溶湯が凝固する直前に、前記軸受部に対し、外径
ｄ＝0.17D〜0.60D（ただし、Ｄは軸受部外径であ
る）なる加圧棒を用いて、仮想ロツカアーム軸中
心線方向の二次加圧力を作用させ、得られた鋳造
品の軸受部に、内径ｒ≧ｄ＋６mmなるロツカアー
ム軸孔を穿孔形成することを特徴とするAl合金
製ロツカアームの製造方法。[Claims] 1. Used in an overhead camshaft valve mechanism of an internal combustion engine.
A manufacturing method of a rocker arm made of Al alloy by die-casting, the rocker arm having a thick bearing part that fits into the rocker arm shaft and integrally equipped with a wear-resistant piece for cam sliding contact with a protrusion on the back surface. In the method, after pouring under pressure toward the wear-resistant piece using a rocker arm mold in which a sprue is formed toward the back side of the wear-resistant piece installed in the mold hole,
Immediately before the molten metal solidifies, a pressurizing rod with an outer diameter d = 0.17D to 0.60D (D is the outer diameter of the bearing) is used to press the bearing in two directions in the direction of the center line of the virtual rocker arm axis. A method for producing a rocker arm made of an Al alloy, comprising: applying a pressing force to form a rocker arm shaft hole having an inner diameter of r≧d+6 mm in the bearing portion of the obtained cast product.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16173786A JPS6325305A (en) | 1986-07-09 | 1986-07-09 | Manufacturing method of Al alloy Rotsuka arm |
| US07/071,652 US4955121A (en) | 1986-07-09 | 1987-07-09 | Method for producing a rocker arm for use in an internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16173786A JPS6325305A (en) | 1986-07-09 | 1986-07-09 | Manufacturing method of Al alloy Rotsuka arm |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6325305A JPS6325305A (en) | 1988-02-02 |
| JPH0375724B2 true JPH0375724B2 (en) | 1991-12-03 |
Family
ID=15740926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16173786A Granted JPS6325305A (en) | 1986-07-09 | 1986-07-09 | Manufacturing method of Al alloy Rotsuka arm |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6325305A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030026624A (en) * | 2001-09-26 | 2003-04-03 | 현대자동차주식회사 | Manufacturing method of rocker arm using semi-solid metal forming |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5797861A (en) * | 1980-12-10 | 1982-06-17 | Toyota Motor Corp | Pressure casting method |
| JPS60121237A (en) * | 1983-12-06 | 1985-06-28 | Nissan Motor Co Ltd | Composite metallic body |
-
1986
- 1986-07-09 JP JP16173786A patent/JPS6325305A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6325305A (en) | 1988-02-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |