JP3186816B2 - Sintered alloy for valve seat - Google Patents
Sintered alloy for valve seatInfo
- Publication number
- JP3186816B2 JP3186816B2 JP01324992A JP1324992A JP3186816B2 JP 3186816 B2 JP3186816 B2 JP 3186816B2 JP 01324992 A JP01324992 A JP 01324992A JP 1324992 A JP1324992 A JP 1324992A JP 3186816 B2 JP3186816 B2 JP 3186816B2
- Authority
- JP
- Japan
- Prior art keywords
- valve seat
- particles
- alloy
- hard particles
- matrix
- 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
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- Powder Metallurgy (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、往復動内燃機関（エン
ジン）のバルブシート、より詳しくは、焼結合金製のバ
ルブシートに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve seat for a reciprocating internal combustion engine, and more particularly to a valve seat made of a sintered alloy.
【０００２】[0002]
【従来の技術】バルブシートはエンジンの吸気および排
気バルブと接触するように配置されて使用されるので、
過酷な熱的・機械的負荷が加わるために、高度の耐熱性
・耐摩耗性が要求されている。そこで、高硬度の高合金
粉末粒子をマトリックス中に分散させることによって、
耐摩耗性を高めた鉄系焼結合金のバルブシートが提案さ
れている（例えば、特公昭５０−１４６０３号公報での
モリブデン（Ｍｏ）粒子、特公昭５７−１９１８８号公
報でのＣ−Ｃｒ−Ｎｉ−Ｍｏ−Ｎｂ−Ｆｅ粒子など、さ
らにマトリックス中に二種類の硬質粒子を分散指せたも
のとして、特公昭５１−４４４８３号公報でのＣ−Ｃｒ
−Ｗ−Ｃｏ−ＦｅおよびＦｅ−Ｍｏ粒子、特公昭５１−
１３０９３号公報でのＣ−Ｃｒ−Ｗ−Ｃｏ−Ｆｅ、Ｆｅ
−Ｍｏ粒子など）。これらの硬質粒子のうちで、Ｆｅ−
Ｍｏ、Ｃ−Ｃｒ−Ｗ−Ｃｏ−Ｆｅは硬度が高く、Ｃ−Ｃ
ｒ−Ｎｉ−Ｍｏ−Ｎｂ−Ｆｅは中程度の硬度であるとい
う特徴を有していた。その他ＮｉやＣｒをマトリックス
に添加して、マトリックス自体の強度、耐熱性を向上さ
せることも行われている。2. Description of the Related Art Since valve seats are used in contact with intake and exhaust valves of an engine,
Since severe thermal and mechanical loads are applied, high heat resistance and wear resistance are required. Therefore, by dispersing high hardness high alloy powder particles in the matrix,
A valve seat made of an iron-based sintered alloy having improved wear resistance has been proposed (for example, molybdenum (Mo) particles in Japanese Patent Publication No. 50-14603, C-Cr- in Japanese Patent Publication No. 57-19188). Ni-Mo-Nb-Fe particles and the like, and two types of hard particles dispersed in a matrix, are referred to as C-Cr in Japanese Patent Publication No. 51-44383.
-W-Co-Fe and Fe-Mo particles, JP-B-51-
No. 13093, C-Cr-W-Co-Fe, Fe
-Mo particles). Of these hard particles, Fe-
Mo and C-Cr-W-Co-Fe have high hardness and C-C
r-Ni-Mo-Nb-Fe had a characteristic of moderate hardness. In addition, Ni and Cr are added to the matrix to improve the strength and heat resistance of the matrix itself.
【０００３】一般的に、エンジンの運転中にバルブシー
トに発生する酸化膜は、バルブとの間に介在して、バル
ブシートとバルブとの金属間接触を防止して、凝着摩耗
や焼付を防止する作用がある。しかしながら、ガスエン
ジン（例えば、コージェネレータ用）や水素エンジン等
の特殊な燃料のエンジンの場合に、燃焼が完全燃焼に近
いため、バルブシートに酸化膜がほとんど形成されな
い。このような特殊燃料の使用と過酷な負荷条件下で
は、上述したバルブシート材料を採用することができな
い。そこで、このようなエンジンに使用するバルブシー
トは、例えば、鉛合金を溶浸した焼結材料やＣａＦ2 を
添加した焼結材料（特開平３−２２５００８号公報参
照）が採用されている。[0003] Generally, an oxide film generated on a valve seat during operation of an engine is interposed between the valve to prevent metal-to-metal contact between the valve seat and the valve, thereby preventing adhesion wear and seizure. It has the effect of preventing. However, in the case of a special fuel engine such as a gas engine (for example, for a co-generator) or a hydrogen engine, since the combustion is close to complete combustion, almost no oxide film is formed on the valve seat. Under the use of such special fuel and severe load conditions, the above-mentioned valve seat material cannot be adopted. Therefore, as a valve seat used in such an engine, for example, a sintered material in which a lead alloy is infiltrated or a sintered material to which CaF 2 is added (see JP-A-3-225008).
【０００４】[0004]
【発明が解決しようとする課題】鉛溶浸の焼結材料で
は、素材焼結後に鉛浴等を用いて再度加熱して溶浸する
必要があって、生産性が劣り、さらに、鉛溶浸時に蒸発
する鉛が溶浸炉の耐久性を低下させたり、作業環境を悪
化させる。また、特開平３−２２５００８号公報のＣａ
Ｆ2 添加焼結材料では、焼結後に鍛造を施し、再度焼結
するので生産性が一層劣る。In the case of a lead-infiltrated sintered material, it is necessary to re-heat and infiltrate the material using a lead bath or the like after sintering the material, resulting in poor productivity and furthermore, lead infiltration. Sometimes evaporating lead reduces the durability of the infiltration furnace or worsens the working environment. Also, Japanese Patent Application Laid-Open No. 3-225008 discloses Ca
In the case of the F 2 -added sintered material, forging is performed after sintering and sintering is performed again, so that productivity is further deteriorated.
【０００５】本発明の目的は、ガスエンジン等の特殊燃
料を使用するエンジンに使用でき、かつ生産性および耐
摩耗性の優れたバルブシートとなるバルブシート用焼結
合金を提供することである。An object of the present invention is to provide a sintered alloy for a valve seat which can be used for an engine using a special fuel such as a gas engine and which is excellent in productivity and wear resistance.
【０００６】[0006]
【課題を解決するための手段】上述の目的が、下記組
成： 炭素： ０．６〜１．０ wt％ クロム： １．６〜４．７ wt％ 鉄および不可避的不純物： 残部 からなる焼結合金スケルトンのマトリックス中に、硬度
ＨＶ５００〜９００の硬質粒子（Ａ）と、硬度ＨＶ１０
００以上の硬質粒子（Ｂ）と、ＣａＦ2 粒子とが、 Ａ ： ２０〜３０ wt％ Ｂ ： １〜１０ wt％ （Ａ＋Ｂ： ３５ wt％未満） ＣａＦ2 ：0.５〜７ wt％ の割合で分散されており、かつ、前記スケルトンの空孔
に銅ないし銅合金が１０〜２０wt％溶浸されていること
を特徴とするバルブシート用焼結合金によって達成され
る。Means for Solving the Problems The above object is achieved by the following composition: carbon: 0.6 to 1.0 wt% Chromium: 1.6 to 4.7 wt% Iron and unavoidable impurities: sinter bonding consisting of the balance In a matrix of a gold skeleton, hard particles (A) having a hardness of HV 500 to 900 and a hardness HV 10
The hard particles (B) of not less than 00 and the CaF 2 particles are: A: 20 to 30 wt% B: 1 to 10 wt% (A + B: less than 35 wt%) CaF 2 : 0.5 to 7 wt% The sintered alloy for a valve seat is characterized in that copper or a copper alloy is infiltrated with 10 to 20% by weight of pores of the skeleton.
【０００７】そして、硬質粒子（Ａ）が下記組成： 炭素： １〜 ４ wt％ クロム： １０〜３０ wt％ ニッケル： ２〜１５ wt％ モリブデン：１０〜３０ wt％ コバルト： ２０〜４０ wt％ ニオブ： １〜 ５ wt％ 鉄および不可避的不純物： 残部 の合金粉末粒子であり、および硬質粒子（Ｂ）がフェロ
モリブデン粒子であることが好ましい。The hard particles (A) have the following composition: carbon: 1-4 wt% chromium: 10-30 wt% nickel: 2-15 wt% molybdenum: 10-30 wt% cobalt: 20-40 wt% niobium : 1 to 5 wt% iron and inevitable impurities: The balance is preferably alloy powder particles, and the hard particles (B) are preferably ferromolybdenum particles.
【０００８】スケルトンのマトリックスが金型用合金工
具鋼、特に、ＳＫＤ１１（ＪＩＳＧ ４４０４）で強化
されていることが望ましい。さらに、スケルトンのマト
リックスが焼戻しマルテンサイト組織を有することも好
ましい。[0008] It is desirable that the matrix of the skeleton be reinforced with alloy tool steel for molds, especially SKD11 (JISG 4404). Furthermore, it is also preferred that the matrix of the skeleton has a tempered martensitic structure.
【０００９】[0009]
【作用】本発明では、ＣａＦ2 粒子を固体潤滑剤として
用いて、金属接触による凝着摩耗を抑制し、焼結合金の
マトリックス中に分散させる硬度の異なる２種類の硬質
粒子とその割合との最適化およびマトリックスの強化を
図ることにより、バルブシート（焼結合金）自身の摩耗
が少なく、かつ摺接相手材のバルブを摩耗させることが
少ないようにしている。そして、２種類の硬質粒子とマ
トリックスからなる焼結スケルトンだけでは、強度が十
分でないので、これを補償するために銅ないし銅合金の
溶浸を行っている。さらに、金型用合金工具鋼（ＳＫＤ
１１）粒子を添加してマトリックスの耐熱性を向上させ
ている。According to the present invention, CaF 2 particles are used as a solid lubricant to suppress cohesive wear due to metal contact and to disperse in a matrix of a sintered alloy two kinds of hard particles having different hardnesses and a ratio thereof. By optimizing and strengthening the matrix, wear of the valve seat (sintered alloy) itself is reduced, and wear of the valve of the sliding contact partner is reduced. Since the strength is not sufficient with only the sintered skeleton composed of the two types of hard particles and the matrix, copper or copper alloy is infiltrated to compensate for the strength. Furthermore, alloy tool steel for molds (SKD)
11) The heat resistance of the matrix is improved by adding particles.
【００１０】マトリックスの組成について、炭素（Ｃ）
はマトリックスを強化し、急冷によるマルテンサイト組
織を与える。このＣ量が、0.６wt％未満では、十分なマ
ルテンサイト組織が得られず、一方、1.０wt％を越える
とセメンタイトが析出し脆化し、残留オーステナイトが
出て焼入性が低下する。クロム（Ｃｒ）はマトリックス
に固溶してその高温強度を高め、硬質粒子の脱落あるい
はマトリックスへの沈み込みを防止する。このＣｒ量
が、1.６wt％未満では、これらの効果が乏しく、一方、
4.７wt％を越えると、添加の割に高温強度の改善がそれ
以上にはない。Regarding the composition of the matrix, carbon (C)
Strengthens the matrix and gives a martensitic structure by quenching. If the C content is less than 0.6 wt%, a sufficient martensite structure cannot be obtained, while if it exceeds 1.0 wt%, cementite precipitates and becomes embrittled, resulting in residual austenite and reduced hardenability. Chromium (Cr) forms a solid solution in the matrix to increase its high-temperature strength and prevents hard particles from falling off or sinking into the matrix. If the Cr content is less than 1.6 wt%, these effects are poor, while
If it exceeds 4.7 wt%, there is no further improvement in high-temperature strength for the addition.
【００１１】マトリックス中に分散する２種類の硬質粒
子（Ａ）および（Ｂ）は、マトリックスの耐摩耗性を高
めるものであり、硬度ＨＶ５００〜９００の硬質粒子
（Ａ）のみでは、マトリックスの摩耗が大きくなり、他
方、硬度ＨＶ１０００以上の硬質粒子（Ｂ）のみでは相
手材バルブの摩耗が大きくなってしまうので、これら２
種類の硬質粒子を併用する。The two types of hard particles (A) and (B) dispersed in the matrix enhance the abrasion resistance of the matrix. With only the hard particles (A) having a hardness of HV 500 to 900, wear of the matrix is reduced. On the other hand, only the hard particles (B) having a hardness of HV1000 or more would increase the wear of the counterpart valve.
A combination of different types of hard particles is used.
【００１２】硬質粒子（Ａ）の割合が、２０wt％では十
分な耐摩耗性が得られず、３０wt％を越えると該硬質粒
子とマトリックスとの結合力が低下し、粉末成形時にク
ラックが入りやすくなって成形が難しくなり、成形用金
型の寿命が短くなり、かつ焼結時の寸法変化（収縮）が
大きいものとなる。そして、硬質粒子（Ｂ）の割合が、
１wt％未満では添加の効果がなく、１０wt％を越えると
粉末成形時にクラックが入りやすくなって成形が難しく
なり、成形用金型の寿命が短くなり、かつ相手材のバル
ブフェース部の摩耗が大きくなってしまう。さらに、こ
れら２種類の硬質粒子（Ａ＋Ｂ）の合計割合が、３５wt
％を越えると粉末の流動性が悪化し粉末成形が難しくな
り、かつ製造時の重量のばらつきが大きくなる。When the proportion of the hard particles (A) is 20% by weight, sufficient abrasion resistance cannot be obtained, and when it exceeds 30% by weight, the bonding force between the hard particles and the matrix is reduced, and cracks are apt to be formed during powder molding. As a result, molding becomes difficult, the life of the molding die is shortened, and the dimensional change (shrinkage) during sintering becomes large. And the ratio of the hard particles (B) is
If it is less than 1 wt%, the effect of addition is not obtained. If it exceeds 10 wt%, cracks are apt to be formed during powder molding, making molding difficult, shortening the life of the molding die and increasing the wear of the valve face of the mating material. turn into. Furthermore, the total ratio of these two types of hard particles (A + B) is 35 wt.
%, The fluidity of the powder deteriorates, the powder molding becomes difficult, and the variation in weight during production increases.
【００１３】ＣａＦ2 粒子は、高温で安定な固体潤滑剤
であり、バルブシートとバルブとの金属間接触を防止し
て凝着摩耗を抑制する作用があり、０．５wt％未満では
摩耗量を低減させる効果が乏しく、７wt％を越えるとバ
ルブシートの強度低下を招き、かつ摩耗量が増加するよ
うになる。CaF 2 particles are solid lubricants that are stable at high temperatures and have the effect of preventing metal-to-metal contact between the valve seat and the valve to suppress cohesive wear. The effect of reducing the amount is poor. If it exceeds 7% by weight, the strength of the valve seat decreases, and the amount of wear increases.
【００１４】金型用合金工具鋼（ＳＫＤ１１）粒子はマ
トリックスの耐熱性を高める効果があり、その為に添加
され、５wt％未満ではその効果が乏しく、１５wt％を越
えると圧粉成形体にクラック（亀裂）が入り易くなり、
かつ高温強度の増加も飽和する。The alloy tool steel for mold (SKD11) has an effect of increasing the heat resistance of the matrix, and is added for that purpose. If it is less than 5% by weight, the effect is poor, and if it exceeds 15% by weight, cracks occur in the compact. (Cracks) easily enter,
In addition, the increase in high-temperature strength is saturated.
【００１５】上述した要件を満たした焼結体はそのスケ
ルトンに空孔があり、この空孔をその空孔量に依存して
１０〜２０wt％の溶浸量にて銅ないし銅合金で満たすな
らば、焼結体の強度および熱伝導性を高めることによ
り、耐摩耗性・耐熱性を高めることができる。２０wt％
を越えると、高温強度、クリープ強度が低下する。硬質
粒子（Ａ）は、Ｆｅ−Ｃｒ、Ｆｅ−Ｍｏ、Ｆｅ−Ｎｂ、
Ｎｉ、Ｃｏ、黒鉛などの材料を下記の組成となるように
配合し、溶解し、鋳造して鋼塊とし、該鋼塊を機械的に
粉砕し、分級して１５０メッシュ以下の合金粉末とした
ものが好ましい。The sintered body satisfying the above requirements has voids in its skeleton, and if these voids are filled with copper or copper alloy at an infiltration amount of 10 to 20% by weight depending on the amount of the voids, For example, abrasion resistance and heat resistance can be increased by increasing the strength and thermal conductivity of the sintered body. 20wt%
If it exceeds, the high temperature strength and the creep strength decrease. Hard particles (A) are Fe-Cr, Fe-Mo, Fe-Nb,
Materials such as Ni, Co, and graphite are blended so as to have the following composition, melted and cast to form a steel ingot, and the steel ingot is mechanically pulverized and classified to obtain an alloy powder of 150 mesh or less. Are preferred.
【００１６】 炭素： １〜 ４ wt％ クロム： １０〜３０ wt％ ニッケル： ２〜１５ wt％ モリブデン：１０〜３０ wt％ コバルト： ２０〜４０ wt％ ニオブ： １〜 ５ wt％ 鉄および不可避的不純物： 残部 この合金粉末粒子はこの組成範囲内で該粒子の硬度（Ｈ
Ｖ５００〜９００）を含めた機械的特性を適宜調整でき
る。なお、この合金粉末は本出願人が特公昭５７−１９
１８８号公報にて提案したものである。Carbon: 1-4 wt% Chromium: 10-30 wt% Nickel: 2-15 wt% Molybdenum: 10-30 wt% Cobalt: 20-40 wt% Niobium: 1-5 wt% Iron and inevitable impurities : Balance The hardness of the alloy powder particles (H
V500 to 900) can be appropriately adjusted. This alloy powder was prepared by the present applicant by Japanese Patent Publication No. 57-19 / 1982.
No. 188.
【００１７】そして、硬質粒子（Ｂ）は、２００メッシ
ュ以下の低炭素フェロモリブデン粒子（粉末）であるこ
とが好ましいが、硬度ＨＶ１０００以上に硬い粒子であ
れば、タングステン（Ｗ）を含む高合金（Ｃ−Ｃｒ−Ｗ
−Ｃｏ系合金やＣ−Ｃｒ−Ｗ−Ｆｅ系合金）の硬質粒子
などであってもよい。The hard particles (B) are preferably low-carbon ferromolybdenum particles (powder) having a mesh size of 200 mesh or less. If the hard particles have a hardness of HV1000 or more, a high alloy containing tungsten (W) ( C-Cr-W
-Co-based alloy or C-Cr-W-Fe-based alloy).
【００１８】[0018]
【実施例】以下、添付図面を参照して、本発明の実施態
様例および比較例によって本発明を詳細に説明する。実
施例および比較例の焼結合金を製造するのに使用する原
料粉末を用意する。硬質粒子（Ａ）としては、Ｆｅ−Ｃ
ｒ、Ｆｅ−Ｍｏ、Ｆｅ−Ｎｂ、Ｎｉ、Ｃｏおよび黒鉛を
下記記載の組成となるように配合し、溶解し、鋳造して
鋼塊とし、該鋼塊を機械的に粉砕し、分級して１５０メ
ッシュ以下の合金粉末とする。 炭素： ２ wt％ クロム： ２０ wt％ ニッケル： ８ wt％ モリブデン： ２０ wt％ コバルト： ３２ wt％ ニオブ： ２ wt％ 鉄および不可避的不純物： 残部 このようにして、硬度ＨＶ６００〜８００、最大粒径１
００μｍ、平均粒径５０μｍの硬質粒子（Ａ）を用意す
る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings with reference to embodiments and comparative examples of the present invention. Raw material powders used for producing the sintered alloys of the examples and comparative examples are prepared. As the hard particles (A), Fe-C
r, Fe-Mo, Fe-Nb, Ni, Co and graphite are blended to have the composition described below, melted, cast into a steel ingot, and the steel ingot is mechanically pulverized and classified. An alloy powder of 150 mesh or less is used. Carbon: 2 wt% Chromium: 20 wt% Nickel: 8 wt% Molybdenum: 20 wt% Cobalt: 32 wt% Niobium: 2 wt% Iron and inevitable impurities: balance In this way, the hardness HV is 600 to 800 and the maximum particle size. 1
Hard particles (A) having a size of 00 μm and an average particle size of 50 μm are prepared.
【００１９】硬質粒子（Ｂ）としては、硬度ＨＶ１３０
０、最大粒径７５μｍ、平均粒径３０μｍの低炭素フェ
ロモリブデン粉末を用意する。ＣａＦ2 粒子としては、
最大粒径１５０μｍ、平均粒径４５μｍの粉末を用意す
る。As the hard particles (B), hardness HV130
0, a low carbon ferromolybdenum powder having a maximum particle size of 75 μm and an average particle size of 30 μm is prepared. As CaF 2 particles,
A powder having a maximum particle size of 150 μm and an average particle size of 45 μm is prepared.
【００２０】鉄系焼結合金（スケルトン）のマトリック
スを構成する材料として、ＳＫＤ１１鋼粉、Ｆｅ−３％
Ｃｒ、ＦｅおよびＣの粉末を用意する。ＳＫＤ１１鋼粉
は、最大粒径１６０μｍ、平均粒径６０μｍのものであ
る。As a material constituting a matrix of an iron-based sintered alloy (skeleton), SKD11 steel powder, Fe-3%
A powder of Cr, Fe and C is prepared. The SKD11 steel powder has a maximum particle size of 160 μm and an average particle size of 60 μm.
【００２１】これらの原料粉末を表１に示すように所定
割合で用意し、ステアリン酸亜鉛を１wt％添加して混合
し、成型圧力５トン／cm2 で圧縮成型して圧粉成形体
（密度：6.３〜6.９ｇ／cm3 、リング形状）を形成す
る。この成形体の上部に所定量の溶浸用銅合金（例え
ば、Ｃｕ−Ｆｅ−Ｍｎ系合金）を配置して、アンモニア
分解ガス雰囲気中で、１１２０℃の温度にて３０分間焼
結を行う。この焼結と同時に溶浸も行われ、成形体密度
が6.８の場合に、可能な銅合金溶浸量は最大１７％にな
るが、スケルトン密度のばらつきもあって、焼結体中の
溶浸量は１０〜２０wt％の範囲にある。These raw material powders were prepared at predetermined ratios as shown in Table 1, 1 wt% of zinc stearate was added and mixed, and the mixture was compression-molded at a molding pressure of 5 ton / cm 2 to obtain a green compact (density). : 6.3 to 6.9 g / cm 3 , ring shape). A predetermined amount of a copper alloy for infiltration (e.g., a Cu-Fe-Mn-based alloy) is arranged on the upper part of the compact, and sintering is performed at a temperature of 1120 ° C for 30 minutes in an ammonia decomposition gas atmosphere. Infiltration is performed simultaneously with this sintering. When the compact density is 6.8, the possible copper alloy infiltration amount is up to 17%, but there is variation in the skeleton density, The amount of infiltration is in the range of 10-20% by weight.
【００２２】[0022]
【表１】 [Table 1]
【００２３】表１に示すように、試料No. １〜７が本発
明の実施例であり、試料No. ８〜１６が比較例である。
試料No. ８および９は銅溶浸量が本発明の限定範囲から
外れており、試料No. １０および１１はＣａＦ2 粒子量
が本発明の限定範囲よりも少ない場合であり、試料No.
１２〜１４はＳＤＫ１１粒子量が本発明の限定範囲より
も少ない場合であり（試料No. １３は硬質粒子Ａが少な
くかつ硬質粒子Ｂが多く場合であり、試料No. １４は硬
質粒子Ｂがない場合であり）、試料No. １５は硬質粒子
Ａが多くかつ硬質粒子Ｂがない場合であり、そして試料
No. １６はＣａＦ2 粒子量が本発明の限定範囲よりも多
い場合である。As shown in Table 1, Sample Nos. 1 to 7 are Examples of the present invention, and Sample Nos. 8 to 16 are Comparative Examples.
Samples Nos. 8 and 9 had copper infiltration amounts outside the limited range of the present invention, and Sample Nos. 10 and 11 were cases where the amount of CaF 2 particles was smaller than the limited range of the present invention.
Samples Nos. 12 to 14 are cases where the amount of SDK11 particles is smaller than the limited range of the present invention (Sample No. 13 is a case where hard particles A are small and hard particles B are many), and Sample No. 14 is a case where hard particles B are not. Sample No. 15 is a case where the hard particles A are large and the hard particles B are absent, and
No. 16 is a case where the amount of CaF 2 particles is larger than the limited range of the present invention.
【００２４】得られる焼結合金リング（バルブシート）
にサブゼロ処理を含む焼入・焼戻し処理を施して、マト
リックスが焼戻しマルテンサイト組織を有するようにす
る。この処理はバルブシートのシリンダヘッドからの脱
落を抑制防止することに寄与する。得られた焼結合金リ
ング（バルブシート）を図１に示すようなバルブシート
摩耗試験機に取り付けて下記条件で摩耗試験を行い、バ
ルブシートおよび相手材のバルブのフェース面の摩耗を
測定する。バルブシートの加熱をガスバーナにて行い、
その際に、バルブシートの表面に酸化膜が生じないよう
にガスバーナの燃焼状態を完全燃焼とする。The resulting sintered alloy ring (valve seat)
Is subjected to a quenching / tempering treatment including a sub-zero treatment so that the matrix has a tempered martensite structure. This process contributes to preventing the valve seat from falling off the cylinder head. The obtained sintered alloy ring (valve seat) is attached to a valve seat abrasion tester as shown in FIG. 1, and a wear test is performed under the following conditions to measure the abrasion of the face of the valve seat and the mating valve. Heat the valve seat with a gas burner,
At this time, the combustion state of the gas burner is set to complete combustion so that no oxide film is formed on the surface of the valve seat.
【００２５】試験条件： バルブ材料： 耐熱鋼（ＳＵＨ３） バルブシート温度： ３００℃ カムシャフト回転数： ２０００rpm 試験時間： １０時間Test conditions: Valve material: Heat resistant steel (SUH3) Valve seat temperature: 300 ° C. Camshaft rotation speed: 2000 rpm Test time: 10 hours
【００２６】なお、バルブシート摩耗試験機は、図１に
示すように、枠１のシートホルダー２に嵌め込まれた焼
結合金リング（バルブシート）３に対して、バルブ４の
フェース面がスプリング５によって当接するようになっ
ている。バルブ４は、電動機６で回転するカムシャフト
７によってロッド８を介して上方へ持ち上げられ、スプ
リング５で戻され、このような往復運動で焼結合金リン
グ（バルブシート）３に当たる。そして、バルブ４をガ
スバーナー９にて加熱し、焼結合金リング（バルブシー
ト）３の温度を熱電対１０で測定している。バルブ４、
スプリング５、カムシャフト８、ロッド８などはエンジ
ン実機部品を用いている。In the valve seat wear tester, as shown in FIG. 1, a face of a valve 4 is attached to a sintered alloy ring (valve seat) 3 fitted in a seat holder 2 of a frame 1 by a spring 5. Is to be brought into contact. The valve 4 is lifted upward via a rod 8 by a camshaft 7 rotated by an electric motor 6, returned by a spring 5, and hits the sintered alloy ring (valve seat) 3 by such a reciprocating motion. Then, the valve 4 is heated by the gas burner 9, and the temperature of the sintered alloy ring (valve seat) 3 is measured by the thermocouple 10. Valve 4,
The spring 5, the camshaft 8, the rod 8, and the like use parts of an actual engine.
【００２７】得られた摩耗量測定値を表１に示す。これ
らの摩耗量結果から、本発明に係るバルブシート（試料
No. １〜７）では、バルブシート自身の摩耗量および相
手材バルブの摩耗量の両方とも比較例の場合よりも少な
いことが分かる。また、酸化膜の生成がなかったこと
が、試験後にバルブシート（試料）の摺動面および断面
組織を観察して確認した。Table 1 shows the measured values of the obtained wear amount. From the results of these wear amounts, the valve seat according to the present invention (sample
In Nos. 1 to 7), it can be seen that both the abrasion amount of the valve seat itself and the abrasion amount of the mating valve are smaller than those of the comparative example. Further, it was confirmed by observation of the sliding surface and the cross-sectional structure of the valve seat (sample) after the test that no oxide film was formed.
【００２８】図２は、ＣａＦ2 添加量とバルブシートお
よびバルブの摩耗量との関係を表１での試料No. １〜
５、１９、１１および１６の結果に基づいてグラフにし
たものであり、０．５〜７wt％の添加量が好適であるこ
とが分かる。FIG. 2 shows the relationship between the amount of CaF 2 added and the amount of wear of the valve seat and the valve.
It is a graph based on the results of 5, 19, 11 and 16, and it is understood that the addition amount of 0.5 to 7 wt% is suitable.
【００２９】なお、本発明に係るバルブシートを、特公
昭５６−４４１２３号公報にて提案されたような異なる
組成の基層と当接層とからなる２層複合焼結バルブシー
トでの当接層に使用することもできる。The valve seat according to the present invention is used as a contact layer in a two-layer composite sintered valve seat comprising a base layer and a contact layer having different compositions as proposed in Japanese Patent Publication No. 56-44123. It can also be used for
【００３０】[0030]
【発明の効果】以上説明したように、本発明に係る焼結
合金バルブシートでは、固体潤滑剤のＣａＦ2 添加、２
種類の硬質粒子の組合せ、マトリックスの強化、合金工
具鋼添加の耐熱性向上およびスケルトンの溶浸強化によ
って、酸化膜の生じない特殊燃料での過酷な負荷条件に
おいてもバルブシート自身の耐摩耗性が優れかつ相手材
のバルブの摩耗をあまり招かない。また、従来の焼結合
金バルブシート製造方法に準じて本発明に係るバルブシ
ートを容易に製造することができる。As described above, in the sintered alloy valve seat according to the present invention, the addition of CaF 2 as a solid lubricant,
The combination of different types of hard particles, strengthened matrix, improved heat resistance by adding alloy tool steel, and enhanced infiltration of the skeleton ensure that the wear resistance of the valve seat itself even under severe load conditions with special fuels that do not generate oxide films Excellent and does not cause much wear of the valve of the mating material. Further, the valve seat according to the present invention can be easily manufactured according to the conventional method for manufacturing a sintered alloy valve seat.
【図１】バルブシート摩耗機の概略部分断面図である。FIG. 1 is a schematic partial sectional view of a valve seat wear machine.
【図２】ＣａＦ2 添加量とバルブシートおよびバルブの
摩耗量との関係を示すグラフである。FIG. 2 is a graph showing the relationship between the amount of CaF 2 added and the amount of wear of a valve seat and a valve.
１…枠 ２…シートホルダー ３…バルブシート（焼結合金リング） ４…バルブ ５…スプリング ７…カムシャフト ８…ロッド DESCRIPTION OF SYMBOLS 1 ... Frame 2 ... Seat holder 3 ... Valve seat (sintered alloy ring) 4 ... Valve 5 ... Spring 7 ... Camshaft 8 ... Rod
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) C22C 38/00 - 38/60 C22C 33/02 B22F 1/00 - 8/00 F01L 3/02 ──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. 7 , DB name) C22C 38/00-38/60 C22C 33/02 B22F 1/00-8/00 F01L 3/02
Claims (3)
ＨＶ５００〜９００の硬質粒子（Ａ）と、硬度ＨＶ１０
００以上の硬質粒子（Ｂ）と、ＣａＦ2 粒子が、 Ａ ： ２０〜３０ wt％ Ｂ ： １〜１０ wt％ （Ａ＋Ｂ： ３５ wt％未満） ＣａＦ2 ：0.５〜７ wt％ の割合で分散されており、かつ、前記スケルトンの空孔
に銅ないし銅合金が１０〜２０wt％溶浸されていること
を特徴とするバルブシート用焼結合金。1. Carbon: 0.6 to 1.0 wt% Chromium: 1.6 to 4.7 wt% Iron and unavoidable impurities: balance Hard particles (A) and hardness HV10
The hard particles (B) of not less than 00 and the CaF 2 particles are: A: 20 to 30 wt% B: 1 to 10 wt% (A + B: less than 35 wt%) CaF 2 : 0.5 to 7 wt% A sintered alloy for a valve seat, wherein the sintered alloy is dispersed and copper or copper alloy is infiltrated into pores of the skeleton by 10 to 20% by weight.
ェロモリブデン粒子であることを特徴とする請求項１記
載の焼結合金。2. The hard particles (A) have the following composition: carbon: 1 to 4 wt% chromium: 10 to 30 wt% nickel: 2 to 15 wt% molybdenum: 10 to 30 wt% cobalt: 20 to 40 wt% Niobium: 1 to 5 wt% Iron and inevitable impurities: The balance is alloy powder particles, and the hard particles (B) are ferromolybdenum particles.
中に、金型用合金工具鋼粉が５〜１５wt％含まれている
ことを特徴とする請求項１記載の焼結合金。3. The sintered alloy according to claim 1, wherein the matrix of the sintered alloy skeleton contains 5 to 15 wt% of alloy tool steel powder for a mold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01324992A JP3186816B2 (en) | 1992-01-28 | 1992-01-28 | Sintered alloy for valve seat |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01324992A JP3186816B2 (en) | 1992-01-28 | 1992-01-28 | Sintered alloy for valve seat |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05202451A JPH05202451A (en) | 1993-08-10 |
| JP3186816B2 true JP3186816B2 (en) | 2001-07-11 |
Family
ID=11827938
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01324992A Expired - Fee Related JP3186816B2 (en) | 1992-01-28 | 1992-01-28 | Sintered alloy for valve seat |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3186816B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6657766B2 (en) | 2000-03-31 | 2003-12-02 | Sharp Kabushiki Kaisha | Reflective display device and retro-reflector used therefor |
| US6951579B2 (en) | 2002-03-15 | 2005-10-04 | Teikoku Piston Ring Co., Ltd. | Sintered alloy for valve seats, valve seat and manufacturing method thereof |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08134607A (en) * | 1994-11-09 | 1996-05-28 | Sumitomo Electric Ind Ltd | Wear resistant ferrous sintered alloy for valve seat |
| JP3346306B2 (en) * | 1998-11-18 | 2002-11-18 | 三菱マテリアル株式会社 | Valve seat made of iron-based sintered alloy |
| JP3346321B2 (en) * | 1999-02-04 | 2002-11-18 | 三菱マテリアル株式会社 | High strength Fe-based sintered valve seat |
| GB2440737A (en) * | 2006-08-11 | 2008-02-13 | Federal Mogul Sintered Prod | Sintered material comprising iron-based matrix and hard particles |
| JP6290107B2 (en) * | 2013-01-31 | 2018-03-07 | 日本ピストンリング株式会社 | Valve seat for internal combustion engine having excellent wear resistance and method for producing the same |
| CN108026800B (en) * | 2015-10-02 | 2020-06-09 | 株式会社理研 | Sintered valve seat |
| JP7286037B1 (en) * | 2022-12-09 | 2023-06-02 | Ｔｐｒ株式会社 | Ferrous sintered alloy valve seats |
-
1992
- 1992-01-28 JP JP01324992A patent/JP3186816B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6657766B2 (en) | 2000-03-31 | 2003-12-02 | Sharp Kabushiki Kaisha | Reflective display device and retro-reflector used therefor |
| US6951579B2 (en) | 2002-03-15 | 2005-10-04 | Teikoku Piston Ring Co., Ltd. | Sintered alloy for valve seats, valve seat and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05202451A (en) | 1993-08-10 |
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