JPH1162698A - Cylinder head for internal combustion engine of light alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head for internal combustion engine made of light alloy whose high-temp. strength of inter-valve part is enhanced, compared with the conventional technique which uses in combination the refusion process and a process to turn into alloy. SOLUTION: Reinforcing fibers are included only in the inter-valve part, where cracking can be prevented effectively if the fibers are oriented two- dimensionally as perpendicular to the piston moving direction. If the part containing the fibers is subjected to a refusion process, strengthening of the matrix itself is ensured owing to a finer constitution with refusion in addition to a complex strengthening with the reinforcing fibers, so that a construction with a higher strength can be established.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、軽合金製内燃機関
用シリンダヘッドに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light alloy cylinder head for an internal combustion engine.

【０００２】[0002]

【従来の技術】Ａｌ合金等の軽合金製内燃機関用シリン
ダヘッドは、高温強度を付与するために種々の改良が行
われている。本出願人は、特開昭６１−１９３７７３号
公報において、アルミニウム合金鋳物製内燃機関用シリ
ンダヘッドに、高密度エネルギー源を用いて再溶融微細
化処理を施し、高温強度および耐亀裂性を向上させる方
法を提案した。この方法によれば、アルミニウム合金鋳
物の鋳造欠陥が減少し、組織が微細化することで高温強
度および耐亀裂性が向上する。2. Description of the Related Art Various improvements have been made to cylinder heads for internal combustion engines made of light alloys such as Al alloys in order to impart high-temperature strength. The present applicant discloses in Japanese Patent Application Laid-Open No. 61-193773 that a cylinder head for an internal combustion engine made of an aluminum alloy casting is subjected to remelting and fine treatment using a high-density energy source to improve high-temperature strength and crack resistance. A method was proposed. According to this method, high-temperature strength and crack resistance are improved by reducing casting defects in the aluminum alloy casting and making the structure finer.

【０００３】本出願人は更に、内燃機関の高性能化が進
んでシリンダヘッドへの負荷が増大すると上記提案の方
法では不十分になるため、特開平６２−３８７８６号公
報において、アルミニウム合金鋳物性内燃機関用シリン
ダヘッドの吸気弁と排気弁との間の部分（弁間部）およ
び燃焼チャンバー孔と吸気弁および排気弁各々との間の
部分（弁／チャンバー間部）に、Ｆｅ、Ｎｉ、Ｃｏ、
Ｖ、Ｚｒ、Ｃｅのうち１種以上を、高密度エネルギーを
照射して合金化させることで、上記の再溶融微細化処理
に加えて合金化による耐熱性向上を行う方法を提案し
た。[0003] The present applicant further discloses that if the performance of the internal combustion engine is improved and the load on the cylinder head is increased, the method proposed above becomes insufficient. Fe, Ni, and the like are provided in a portion between the intake valve and the exhaust valve of the cylinder head for the internal combustion engine (an inter-valve portion) and a portion between the combustion chamber hole and each of the intake valve and the exhaust valve (the inter-valve / chamber portion). Co,
A method has been proposed in which one or more of V, Zr, and Ce are alloyed by irradiating high-density energy, thereby improving the heat resistance by alloying in addition to the remelting and miniaturizing treatment.

【０００４】しかし、内燃機関を更に高性能化するため
には、シリンダヘッドを更に高強度化する必要がある。However, in order to further improve the performance of the internal combustion engine, it is necessary to further increase the strength of the cylinder head.

【０００５】[0005]

【発明が解決しようとする課題】本発明は、再溶融処理
と合金化とを併用した従来方法よりも更に弁間部の高温
強度を向上させた軽金属製内燃機関用シリンダヘッドを
提供することを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a cylinder head for a light metal internal combustion engine in which the high-temperature strength of an inter-valve portion is further improved as compared with the conventional method using both remelting and alloying. Aim.

【０００６】[0006]

【課題を解決するための手段】上記の目的を達成するた
めに、本発明によれば、弁間部にのみ強化繊維を含有す
ることを特徴とする軽合金製内燃機関用シリンダヘッド
が提供される。本発明のシリンダヘッドは、特に強度が
要求される弁間部を強化繊維で複合強化したことによ
り、従来の再溶融＋合金化に比べて更に強度が向上す
る。According to the present invention, there is provided, in accordance with the present invention, a cylinder head for a light alloy internal combustion engine, characterized in that only an inter-valve portion contains reinforcing fibers. You. In the cylinder head of the present invention, the inter-valve portion, which particularly requires strength, is reinforced with composite fibers, thereby further improving the strength as compared with the conventional remelting + alloying.

【０００７】[0007]

【発明の実施の形態】本発明のシリンダヘッドにおいて
は、弁間部が軽金属又は軽合金のマトリクス中に強化繊
維が分散した複合材料として形成される。典型的な製造
方法は、金型キャビティー内の弁間部造形箇所に強化繊
維の加圧成形体を配置し、軽金属又は軽合金の溶湯を注
湯して鋳ぐるむ方法である。DETAILED DESCRIPTION OF THE INVENTION In the cylinder head of the present invention, an inter-valve portion is formed as a composite material in which reinforcing fibers are dispersed in a matrix of a light metal or a light alloy. A typical manufacturing method is a method in which a pressure-molded body of a reinforcing fiber is arranged at a molding portion of an inter-valve portion in a mold cavity, and a light metal or light alloy melt is poured and cast.

【０００８】鋳ぐるみ法で製造する観点から、強化繊維
の材質は、マトリクス用の軽金属又は軽合金の溶湯と濡
れ性は良いが実質的に化学反応はせず、溶湯によって損
傷を受けない材質が適当である。一般に、同様の製造方
法で繊維分散強化型軽金属複合材料を製造するのに用い
られる強化繊維であればよい。典型的には、強化繊維は
Ｆｅ、Ｃｕ、Ｔｉ、Ａｌ、黄銅、青銅等の金属の繊維で
あり、各繊維を単独で用いてもよいし、複数種類の繊維
を混合して用いてもよい。From the viewpoint of manufacturing by the as-cast method, the material of the reinforcing fiber is a material which has good wettability with the molten metal or light alloy for the matrix but does not substantially react chemically and is not damaged by the molten metal. Appropriate. Generally, any reinforced fiber used for producing a fiber-dispersed reinforced light metal composite material by a similar production method may be used. Typically, the reinforcing fibers are metal fibers such as Fe, Cu, Ti, Al, brass, and bronze, and each fiber may be used alone or a mixture of a plurality of types of fibers may be used. .

【０００９】強化繊維の形態は、特に限定する必要はな
いが、例えば自動車エンジン用あるいは類似用途のシリ
ンダヘッドの場合、直径３０〜１００μｍ程度、長さ２
〜５ｍｍ程度のいわゆる短繊維が一般に用いられる。強
化繊維は複合部の総体積に対して４０ vol％程度以上と
すると特に顕著な複合強化作用が得られる。The form of the reinforcing fibers is not particularly limited. For example, in the case of a cylinder head for an automobile engine or similar use, the diameter is about 30 to 100 μm and the length is 2
So-called short fibers of about 5 mm are generally used. Particularly remarkable composite reinforcing action can be obtained when the reinforcing fibers are set at about 40 vol% or more with respect to the total volume of the composite portion.

【００１０】特に、Ａｌ又はＡｌ合金をマトリクスと
し、上記金属繊維を複数種類混合して用いる場合、Ｔｉ
繊維を繊維総体積に対して１５ vol％程度以上とする
と、Ａｌ又はＡｌ合金の溶湯に対して繊維成形体全体と
して良好な濡れ性が得られ、鋳ぐるみ法（含浸法）にお
いて良好な含浸性すなわち高い複合性が確保できる。弁
間部では、ピストンの運動方向を基準にとると、それに
対して垂直な方向に亀裂が開口するから、強化繊維がピ
ストンの運動方向に対して垂直に２次元配向しているこ
とが亀裂発生防止に特に有効である。In particular, when Al or an Al alloy is used as a matrix and a plurality of types of the above metal fibers are used in combination,
When the fiber is about 15 vol% or more based on the total volume of the fiber, good wettability of the whole fiber molded body with respect to the molten Al or Al alloy is obtained, and good impregnation in the cast-in method (impregnation method). That is, high composite property can be secured. In the inter-valve part, cracks are opened in the direction perpendicular to the piston movement direction based on the piston movement direction, so that the reinforcing fibers are two-dimensionally oriented perpendicular to the piston movement direction. Especially effective for prevention.

【００１１】更に、強化繊維含有部に再溶融処理を施す
ことにより、強化繊維による複合強化に加えて再溶融微
細化によりマトリクス自体の強化も付加され、より一層
の高強度化が可能になる。この再溶融処理は、前出の従
来技術と同様に、レーザ、電子ビーム、プラズマアー
ク、ＴＩＧアーク等の高密度エネルギーを照射すること
により行うことができる。Further, by subjecting the reinforcing fiber-containing portion to the remelting treatment, the matrix itself is strengthened by remelting and miniaturization in addition to the composite reinforcement by the reinforcing fibers, so that the strength can be further increased. This re-melting treatment can be performed by irradiating high-density energy such as a laser, an electron beam, a plasma arc, a TIG arc or the like, similarly to the above-mentioned conventional technology.

【００１２】[0012]

【実施例】【Example】

〔実施例１〕強化繊維として、下記のＦｅ繊維、Ｔｉ繊
維、Ｃｕ繊維、Ａｌ繊維、黄銅繊維、青銅繊維を用い、
表１の示したように単独または複数種類を混合し、加圧
成形を行って繊維成形体（形状：３０ｍｍ×３０ｍｍ×
１０ｍｍ）を作成した。[Example 1] As the reinforcing fibers, the following Fe fibers, Ti fibers, Cu fibers, Al fibers, brass fibers, and bronze fibers were used.
As shown in Table 1, a single fiber or a mixture of a plurality of types is subjected to pressure molding to form a fiber molded body (shape: 30 mm × 30 mm ×
10 mm).

【００１３】＜用いた金属繊維＞ Ｆｅ繊維：虹枝（株）製、ＪＩＳ−Ｓ１０Ｃ、径３０μ
ｍ、長さ2.5 ｍｍ Ｔｉ繊維：東京製綱（株）製、純度９９．７％、径３０
μｍ、長さ３ｍｍ Ｃｕ繊維：虹枝（株）製、ＪＩＳ−Ｃ１１００、径３０
μｍ、長さ３ｍｍ Ａｌ繊維：虹枝（株）製、ＪＩＳ−Ａ５０５２、径３０
μｍ、長さ３ｍｍ 黄銅繊維：虹枝（株）製、ＪＩＳ−Ｃ２６００、径３０
μｍ、長さ３ｍｍ 青銅繊維：虹枝（株）製、ＪＩＳ−ＢＣ６Ｃ、径３０μ
ｍ、長さ３ｍｍ 各成形体をＡＣ２Ｃ溶湯（温度：７５０℃）中に３０秒
間浸漬した後、取り出して凝固させた。得られた鋳物を
切断して断面の組織を観察し、複合性（含浸の度合い）
を調べた。その結果を併せて表１に示す。<Metal fiber used> Fe fiber: manufactured by Nijie Co., Ltd., JIS-S10C, diameter 30 μm
m, length 2.5 mm Ti fiber: manufactured by Tokyo Seimitsu Co., Ltd., purity 99.7%, diameter 30
μm, length 3 mm Cu fiber: manufactured by Nijie Co., Ltd., JIS-C1100, diameter 30
μm, length 3 mm Al fiber: manufactured by Nijie Co., Ltd., JIS-A5052, diameter 30
μm, length 3 mm Brass fiber: manufactured by Nijie Co., Ltd., JIS-C2600, diameter 30
μm, length 3 mm Bronze fiber: manufactured by Nijie Co., Ltd., JIS-BC6C, diameter 30 μ
m, length 3 mm Each molded body was immersed in a molten AC2C (temperature: 750 ° C.) for 30 seconds, then taken out and solidified. The obtained casting is cut and the structure of the cross section is observed, and the composite (degree of impregnation)
Was examined. Table 1 also shows the results.

【００１４】[0014]

【表１】 [Table 1]

【００１５】表１に示したように、この例ではＴｉ繊維
以外の繊維を単独で、またはＴｉ繊維と混合し、あるい
は更に他の繊維と混合して用いた。どの繊維もＴｉ繊維
と混合することにより複合性（含浸性）が向上した。上
記で良好な複合性（○：完全含浸）が得られたものと同
じ繊維配合比の繊維成形体をそれぞれ作製した。繊維成
形体をシリンダヘッド鋳造用金型キャビティー内の弁間
部造形箇所に配置し、ＡＣ２Ｃ溶湯（温度：７５０℃）
を注湯して、シリンダヘッドを鋳造した。As shown in Table 1, in this example, fibers other than Ti fibers were used alone, mixed with Ti fibers, or mixed with other fibers. By mixing any of the fibers with the Ti fibers, the composite property (impregnation property) was improved. Fiber molded articles having the same fiber compounding ratio as those in which good composite properties (good: completely impregnated) were obtained above were produced. The fiber molding is placed in the molding area between the valves in the cavity of the cylinder head casting mold, and the AC2C molten metal (temperature: 750 ° C.)
Was poured to cast a cylinder head.

【００１６】鋳造されたシリンダヘッドの弁間部から複
合材料を切り出し、Ｔ６処理を施した後、機械加工によ
り引張試験片を作製した。これを２５０℃に２００時間
保持した後に、繊維配向面に沿って引張試験を行い、２
５０℃強度特性を評価した。その結果、ＡＣ２Ｃに比べ
て耐力が３０〜６０％向上していた。上記の例では、強
化繊維はいずれも径３０μｍのものを用いたが、径６０
μｍ、９０μｍのものについても同様に試料を作製して
試験を行った結果、同様の特性が得られた。The composite material was cut out from the inter-valve portion of the cast cylinder head, subjected to T6 treatment, and then machined to produce a tensile test piece. After maintaining this at 250 ° C. for 200 hours, a tensile test was performed
The 50 ° C. strength characteristics were evaluated. As a result, the yield strength was improved by 30 to 60% as compared with AC2C. In the above example, the reinforcing fibers each having a diameter of 30 μm were used.
The same characteristics were obtained as a result of preparing and testing samples for μm and 90 μm in the same manner.

【００１７】また上記の例では繊維長は２．５ｍｍまた
は３ｍｍのものを用いたが、繊維長５ｍｍのものについ
ても同様に試料を作製して試験を行った結果、同様の特
性が得られた。 〔実施例２〕実施例１のNo. １１と同様に繊維成形体を
弁間部に複合させたシリンダヘッドを鋳造した後、複合
部にＴＩＧアークを照射して再溶融処理を施した。In the above example, a fiber having a fiber length of 2.5 mm or 3 mm was used, but a sample having a fiber length of 5 mm was prepared and tested in the same manner. As a result, similar characteristics were obtained. . Example 2 In the same manner as in No. 11 of Example 1, after casting a cylinder head in which a fiber molded body was compounded in the inter-valve portion, a TIG arc was applied to the composite portion to perform a re-melting treatment.

【００１８】ＴＩＧアークの照射には、日立製作所性の
ARC-PAIR 200TX溶接機を用い、スライダーとして松本機
械製MAC-O-MATIC XII を用いた。溶接電流は直流１３０
〜１６０Ａとし、トーチ移動速度２０〜６０ｍｍ／分、
ウィービング幅３０ｍｍ、ウィービング速度４５回／分
であった。一般にアルミニウム合金の溶接については、
酸化皮膜を打ち破るクリーニング作用が必要とされるた
め交流ＴＩＧが用いられるが、本発明における再溶融処
理に関しては、交流ＴＩＧでは鋳造欠陥の減少効果が少
ないため直流ＴＩＧの方が有利であることが分かった。The TIG arc irradiation is performed by Hitachi, Ltd.
An ARC-PAIR 200TX welding machine was used, and MAC-O-MATIC XII manufactured by Matsumoto Kikai was used as a slider. The welding current is DC 130
~ 160A, torch moving speed 20 ~ 60mm / min,
The weaving width was 30 mm, and the weaving speed was 45 times / min. Generally, for welding aluminum alloys,
AC TIG is used because a cleaning action to break down the oxide film is required. However, regarding the remelting treatment in the present invention, DC TIG is more advantageous because AC TIG has a small effect of reducing casting defects. Was.

【００１９】トーチの移動速度と溶接電流を表２に○印
で示した組合せにすると、良好な溶け込み状態が得られ
た。When the moving speed of the torch and the welding current were set to the combinations indicated by the circles in Table 2, a good penetration state was obtained.

【００２０】[0020]

【表２】 [Table 2]

【００２１】上記の良好な組合せで再溶融処理を施した
シリンダヘッドについて、実施例１と同様に２５０℃強
度特性を調べたところ、実施例１のNo. １１に比べて高
温耐力が更に約１５％向上していることが分かった。実
施例１のNo. ２２についても同様に高温耐力向上が認め
られた。A 250 ° C. strength characteristic of the cylinder head having been subjected to the re-melting treatment in the above-mentioned favorable combination was examined in the same manner as in Example 1. % Improvement. Similarly, in No. 22 of Example 1, improvement in high-temperature proof stress was recognized.

【００２２】[0022]

【発明の効果】以上説明したように、本発明によれば、
再溶融処理と合金化とを併用した従来方法よりも更に弁
間部の高温強度を向上させた軽金属製内燃機関用シリン
ダヘッドが提供される。As described above, according to the present invention,
Provided is a light metal internal combustion engine cylinder head in which the high-temperature strength of the inter-valve portion is further improved as compared with the conventional method using both remelting and alloying.

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 弁間部にのみ強化繊維を含有することを
特徴とする軽合金製内燃機関用シリンダヘッド。1. A light alloy internal combustion engine cylinder head characterized in that it contains reinforcing fibers only in the inter-valve portion. 【請求項２】 前記強化繊維はピストンの運動方向に対
して垂直に２次元配向していることを特徴とする請求項
１記載の軽合金製内燃機関用シリンダヘッド。2. The cylinder head for a light alloy internal combustion engine according to claim 1, wherein the reinforcing fibers are two-dimensionally oriented perpendicular to the direction of movement of the piston. 【請求項３】 前記強化繊維含有部は再溶融処理が施さ
れていることを特徴とする請求項１または２記載の軽合
金製内燃機関用シリンダヘッド。3. The cylinder head for a light alloy internal combustion engine according to claim 1, wherein the reinforcing fiber-containing portion is subjected to a re-melting treatment.