JP2547815B2 - Piston for internal combustion engine - Google Patents
Piston for internal combustion engineInfo
- Publication number
- JP2547815B2 JP2547815B2 JP5659988A JP5659988A JP2547815B2 JP 2547815 B2 JP2547815 B2 JP 2547815B2 JP 5659988 A JP5659988 A JP 5659988A JP 5659988 A JP5659988 A JP 5659988A JP 2547815 B2 JP2547815 B2 JP 2547815B2
- Authority
- JP
- Japan
- Prior art keywords
- piston
- alloy
- internal combustion
- combustion engine
- intermetallic compound
- 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 - Fee Related
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
- F02F3/00—Pistons
- F02F3/0015—Multi-part pistons
- F02F3/003—Multi-part pistons the parts being connected by casting, brazing, welding or clamping
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/02—Light metals
- F05C2201/021—Aluminium
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は自動車エンジン等の内燃機関に用いるピスト
ンに関する。The present invention relates to a piston used in an internal combustion engine such as an automobile engine.
内燃機関用のピストンの材質としては、燃費向上を図
るため軽量なアルミニウム合金AC8Aが主流になりつつあ
る。As a material for pistons for internal combustion engines, the lightweight aluminum alloy AC8A is becoming the mainstream in order to improve fuel efficiency.
しかし、従来のAl合金からなるピストンは第３図に示
すように、ピストンの基部１及び頂部２とも同一材料AC
8Aから作成されていたので、特に高温にさらされる頂部
２の耐熱性及び耐摩耗性が充分でなかつた。However, as shown in FIG. 3, a piston made of a conventional Al alloy has the same material AC for both the base 1 and the top 2 of the piston.
Since it was made of 8A, the heat resistance and wear resistance of the top portion 2 which was particularly exposed to high temperature were not sufficient.
そこで、ピストンの耐熱性を高めるために、第４図に
示すように耐熱性に優れた鋳鉄製頂部４を具え、基部１
をAl合金とした鋳鉄クラウンピストンが開発された。し
かし、鋳鉄製頂部４は重いうえ、熱伝導性が悪いので高
温になり、破損する危険があつた。また、Al合金のピス
トン頂部にジルコニアやアルミナ等の溶射層を形成して
耐熱性を高めたプラズマ溶射ピストンも提案されている
が、溶射層の剥離、脱落、亀裂等が生じやすく、信頼性
に欠けていた。Therefore, in order to improve the heat resistance of the piston, a cast iron top 4 having excellent heat resistance is provided as shown in FIG.
A cast iron crown piston made of Al alloy was developed. However, since the cast iron top part 4 is heavy and has poor thermal conductivity, it has a high temperature and may be damaged. Also, plasma sprayed pistons have been proposed in which a thermal sprayed layer of zirconia, alumina, etc. is formed on the top of the Al alloy piston to improve heat resistance, but the thermal sprayed layer tends to peel, fall off, crack, etc. Was missing.
尚、第３図のピストンには第４図のピストンにない円
柱状のキヤビテイ３が頂部２の中央に形成してあるが、
このキヤビテイ３は直噴型デイーゼルエンジン等のピス
トンに特有の構造である。The piston shown in FIG. 3 has a cylindrical cavity 3 which is not formed in the piston shown in FIG.
This cavity 3 has a structure peculiar to a piston of a direct injection type diesel engine or the like.
最近では窒化珪素等のセラミツクスからなるピストン
も研究され、熱効率の向上が期待されているが、高価で
あるうえ、割れやすい欠点があり、皿に軸部分の潤滑を
いかに解決するか等の問題が残されている。Recently, pistons made of ceramics such as silicon nitride have also been researched and expected to improve thermal efficiency, but they are expensive and have the drawback of being easily cracked, and there are problems such as how to solve the lubrication of the shaft part of the dish. It is left.
本発明は上記した様な従来の事情に鑑み、軽量である
と同時に耐熱性及び耐摩耗性に優れ、過酷な条件下でも
亀裂や破損等の発生のない信頼性に富む内燃機関用ピス
トンを低コストにて提供することを目的とする。In view of the conventional circumstances as described above, the present invention provides a low-priced internal combustion engine piston that is lightweight and at the same time excellent in heat resistance and wear resistance, and does not cause cracks or damage even under severe conditions. It is intended to be provided at cost.
上記目的を達成するために、本発明の内燃機関用ピス
トンにおいては、ピストンの基部がアルミニウム合金か
らなり、基部に接合した頂部がAl30〜36重量％を含む金
属間化合物TiAl系合金からなることを特徴とする。In order to achieve the above object, in the piston for an internal combustion engine of the present invention, the base of the piston is made of an aluminum alloy, and the top joined to the base is made of an intermetallic compound TiAl-based alloy containing 30 to 36% by weight of Al. Characterize.
金属間化合物TiAl系合金は特公昭62−215号公報に記
載されるように、結晶構造がLI0の金属間化合物TiAlを
含む合金である。この合金はAl含有量26〜36重量％の範
囲でTiAl相とTi3Al相との２相合金となるが、Al含有量3
0重量％未満ではTi3Al相が多いため脆く、36重量％をこ
えるとTi3Al相がなくなり組織が粗大化する。依つて、A
l含有量が26〜36重量％の範囲でTiAl相がTi3Al相より多
く組織が微細化し、優れた耐熱性が得られるものであ
る。更に、延性を向上させるためにMnを添加することが
でき、最も好ましい組成としてはTi60〜70重量％、Al30
〜36重量％及びMn0.1〜5.0重量％である。The intermetallic compound TiAl-based alloy is an alloy containing an intermetallic compound TiAl having a crystal structure of LI 0 , as described in JP-B-62-215. This alloy becomes a two-phase alloy of TiAl phase and Ti 3 Al phase in the Al content range of 26 to 36% by weight.
If it is less than 0% by weight, the Ti 3 Al phase is large and thus it is brittle, and if it exceeds 36% by weight, the Ti 3 Al phase disappears and the structure becomes coarse. Therefore, A
When the l content is in the range of 26 to 36% by weight, the TiAl phase is finer than the Ti 3 Al phase and the structure becomes finer, resulting in excellent heat resistance. Further, Mn can be added to improve ductility, and the most preferable composition is Ti60 to 70% by weight, Al30
~ 36 wt% and Mn 0.1-5.0 wt%.
この金属間化合物TiAl系合金の製造は目的組成の合金
粉末を熱間加工により緻密化する方法によるが、精密鋳
造法によつても製造できる。The intermetallic compound TiAl-based alloy is produced by a method of densifying an alloy powder having a desired composition by hot working, but it can also be produced by a precision casting method.
この金属間化合物TiAl系合金をAl合金からなるピスト
ンの基部に接合するためには、従来と同様のプロセスを
用いることができる。しかし、好ましい方法としては、
頂部となる金属間化合物TiAl系合金を外径がピストン基
部より小さい円板状又は円環状に形成し、その外周を基
部のアルミニウム合金で鋳ぐるみする。金属間化合物Ti
Al系合金はアルミニウム合金となじみ性がよいので、上
記の鋳ぐるみによる方法で頂部と基部とを簡単かつ強固
に接合することができ、しかもこの方法によれば少ない
切削加工量ですむ利点がある。In order to bond this intermetallic compound TiAl-based alloy to the base of the piston made of Al alloy, the same process as the conventional process can be used. However, the preferred method is
An intermetallic compound TiAl alloy serving as the top is formed into a disk shape or an annular shape having an outer diameter smaller than the piston base, and the outer periphery thereof is casted with the aluminum alloy of the base. Intermetallic compound Ti
Since Al-based alloys have good compatibility with aluminum alloys, the top part and the base part can be easily and firmly joined together by the above-mentioned casting process method, and this method has the advantage of requiring a small cutting amount. .
金属間化合物TiAl系合金はAl合金よりも重いが鋳鉄等
よりもはるかに軽く、しかも耐熱性及び耐摩耗性がAl合
金よりも高く優れている。例えば組成（重量％）がTi−
33Al−2Mnの合金の圧縮耐力は、室温で50kg/mm2、500℃
で55kg/mm2及び700℃で60kg/mm2である。The intermetallic compound TiAl-based alloy is heavier than the Al alloy, but much lighter than cast iron and the like, and has higher heat resistance and wear resistance than the Al alloy. For example, the composition (% by weight) is Ti-
The compressive strength of 33Al-2Mn alloy is 50kg / mm 2 , 500 ℃ at room temperature.
At 55 kg / mm 2 and at 700 ° C 60 kg / mm 2 .
従つて、この金属間化合物TiAl系合金を、特に耐熱性
と耐摩耗性を必要とするピストンの頂部にのみ使用し、
ピストン基部には従来どおり軽量のAl合金を用いること
によつて、軽量化による燃費の向上と同時に過酷な条件
下でも頂部の亀裂や破損がなくなりピストンの信頼性を
高めることができる。また、ピストンの頂部にのみ金属
間化合物TiAl系合金を用いることは、切削加工を削減
し、経済性を高めるうえでも有利である。Therefore, this intermetallic compound TiAl alloy is used only on the top of the piston, which requires heat resistance and wear resistance,
By using a lightweight Al alloy for the piston base as before, it is possible to improve fuel efficiency by reducing the weight and at the same time eliminate cracks and breaks at the top even under harsh conditions to improve the reliability of the piston. In addition, the use of the intermetallic compound TiAl-based alloy only on the top of the piston is advantageous in reducing cutting work and improving economy.
実施例１ 組成がTi−33Al−2Mn（重量％）の金属間化合物TiAl
系合金の粉末を800℃にて熱間押出して直径50mmの丸棒
を作成し、これを厚さ14mmに切断した後、直径48mm×厚
さ12mmの円板に切削加工した。この円板の外周を800℃
にてAl合金AC8Aで鋳ぐるみし、切削加工して、第１図に
示すように円板のTiAl系合金製頂部５をAl合金AC8Aの基
部１につらいちに埋め込んで接合したピストンを製造し
た。Example 1 An intermetallic compound TiAl having a composition of Ti-33Al-2Mn (% by weight)
The alloy powder was hot extruded at 800 ° C. to form a round bar with a diameter of 50 mm, which was cut to a thickness of 14 mm and then cut into a disk having a diameter of 48 mm and a thickness of 12 mm. The outer circumference of this disc is 800 ℃
In the above, a piston was manufactured by casting a cast body of Al alloy AC8A and cutting it, and as shown in FIG. .
このピストンと従来の全体が鋳造Al合金AC8Aからなる
ピストンとを夫々ガソリンエンジンに装着し、ノツキン
グ発生の異常燃焼条件で200時間運転したところ、従来
の鋳造Al合金AC8Aピストンでは頂部に溶損がみられた
が、本発明のピストンでは全く溶損がみられなかつた。This piston and a conventional piston made entirely of cast Al alloy AC8A were installed in a gasoline engine, respectively, and operated for 200 hours under abnormal combustion conditions where knotting occurred. However, no melting loss was observed in the piston of the present invention.
実施例２ 実施例１と同様にして組成がTi−33Al−2Mn（重量
％）の金属間化合物TiAl系合金からなり、中心に内径14
mmの貫通孔を有する外径48mm×厚さ9mmの円板を作成し
た。この円板の外周を実施例１と同様にしてAl合金AC8A
で鋳ぐるみし、切削加工することにより、第２図に示す
ように、TiAl系合金製頂部５をAl合金AC8Aの基部１につ
らいちに埋め込んで接合した頂部中央にキヤビテイ３を
有する直噴型デイーゼルエンジン用ピストンを製造し
た。Example 2 Similar to Example 1, the composition was made of an intermetallic compound TiAl-based alloy having a composition of Ti-33Al-2Mn (wt%), and an inner diameter of 14
A disk having an outer diameter of 48 mm and a thickness of 9 mm having a through hole of mm was prepared. The outer periphery of this disk was made to be the same as in Example 1 using Al alloy AC8A.
As shown in Fig. 2, by directly casting the whole body in a cast iron and cutting it, a TiAl alloy top 5 is embedded directly in the base 1 of the Al alloy AC8A and joined, and the direct injection type has the cavity 3 in the center of the top. Manufactured pistons for diesel engines.
このピストンと第３図に示す従来の全体が鋳造Al合金
AC8Aからなるピストンを、誘導加熱と空気吹き付けのヒ
ートサイクルによる熱疲労テストに供した。ピストン頂
部、特にキヤビテイ３周辺での疲労クラツクの数を螢光
探傷法にて計数し、結果を下記に示した。サイクル数 本発明例 従来例（AC8A） 1×103 ０ 2 5×103 ０ 10 7×103 １ 24 10×103 ３ 47 本発明による金属間化合物TiAl系合金からなる頂部を
有するピストンは、従来のAl合金製ピストンに比べて、
耐熱性が飛躍的に優れていることがわかる。This piston and the conventional whole shown in Fig. 3 are cast aluminum alloys.
A piston made of AC8A was subjected to a thermal fatigue test by a heat cycle of induction heating and air blowing. The number of fatigue cracks at the top of the piston, especially around the cavity 3, was counted by the fluorescent flaw detection method, and the results are shown below. Number of Cycles Inventive Example Conventional Example (AC8A) 1 × 10 3 0 2 5 × 10 3 0 10 7 × 10 3 1 24 10 × 10 3 3 47 A piston having a top made of an intermetallic compound TiAl-based alloy according to the present invention is , Compared to the conventional Al alloy piston,
It can be seen that the heat resistance is dramatically superior.
本発明によれば、軽量でしかも耐熱性及び耐摩耗性に
優れ、高性能であつて且つ過酷な条件下でも亀裂や破損
等の発生が少ない信頼性に富んだ内燃機関用ピストンを
提供することができる。According to the present invention, it is possible to provide a highly reliable piston for an internal combustion engine that is lightweight, has excellent heat resistance and wear resistance, has high performance, and has little occurrence of cracks or damage even under severe conditions. You can
また、本発明のピストンは従来の製造プロセスを用い
て製造できるので、コスト的にも充分に実用性があり、
レーシング用のみならずヘビーデユーテイ用として利用
価値が高い。Further, since the piston of the present invention can be manufactured using the conventional manufacturing process, it is sufficiently practical in terms of cost,
It has high utility value not only for racing but also for heavy duty.
第１図及び第２図は夫々本発明の内燃機関用ピストンの
具体例を示す断面図であり、第３図及び第４図は夫々従
来の内燃機関用ピストンの断面図である。 １……基部、２……頂部、３……キヤビテイ ４……鋳鉄製頂部、５……TiAl系合金製頂部1 and 2 are sectional views showing specific examples of pistons for internal combustion engines of the present invention, and FIGS. 3 and 4 are sectional views of conventional pistons for internal combustion engines. 1 ... Base part, 2 ... Top part, 3 ... Cavity 4 ... Cast iron top part, 5 ... TiAl alloy top part
Claims (2)
り、基部に接合した頂部がAl30〜36重量％を含む金属間
化合物TiAl系合金からなることを特徴とする内燃機関用
ピストン。1. A piston for an internal combustion engine, wherein the base of the piston is made of an aluminum alloy, and the top portion joined to the base is made of an intermetallic compound TiAl-based alloy containing 30 to 36% by weight of Al.
部のアルミニウム合金で鋳ぐるみして接合した請求項
（１）記載の内燃機関用ピストン。2. The piston for an internal combustion engine according to claim 1, wherein the outer periphery of the intermetallic compound TiAl-based alloy at the top is cast and joined with the aluminum alloy at the base.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5659988A JP2547815B2 (en) | 1988-03-10 | 1988-03-10 | Piston for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5659988A JP2547815B2 (en) | 1988-03-10 | 1988-03-10 | Piston for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01232153A JPH01232153A (en) | 1989-09-18 |
| JP2547815B2 true JP2547815B2 (en) | 1996-10-23 |
Family
ID=13031679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5659988A Expired - Fee Related JP2547815B2 (en) | 1988-03-10 | 1988-03-10 | Piston for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2547815B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5518820A (en) * | 1992-06-16 | 1996-05-21 | General Electric Company | Case-hardened titanium aluminide bearing |
| JP6015185B2 (en) * | 2012-07-18 | 2016-10-26 | いすゞ自動車株式会社 | Piston structure of internal combustion engine |
-
1988
- 1988-03-10 JP JP5659988A patent/JP2547815B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01232153A (en) | 1989-09-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |