JPH1121679A - Machine structural parts covered with ceramic heat insulation material - Google Patents
Machine structural parts covered with ceramic heat insulation materialInfo
- Publication number
- JPH1121679A JPH1121679A JP17788997A JP17788997A JPH1121679A JP H1121679 A JPH1121679 A JP H1121679A JP 17788997 A JP17788997 A JP 17788997A JP 17788997 A JP17788997 A JP 17788997A JP H1121679 A JPH1121679 A JP H1121679A
- Authority
- JP
- Japan
- Prior art keywords
- heat insulating
- ceramic heat
- insulating member
- ceramic
- heat insulation
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B77/00—Component parts, details or accessories, not otherwise provided for
- F02B77/02—Surface coverings of combustion-gas-swept parts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B77/00—Component parts, details or accessories, not otherwise provided for
- F02B77/11—Thermal or acoustic insulation
-
- 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
- F02F7/00—Casings, e.g. crankcases or frames
- F02F7/0085—Materials for constructing engines or their parts
- F02F7/0087—Ceramic materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
- F02B2275/16—Indirect injection
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Ceramic Engineering (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
- Fuel-Injection Apparatus (AREA)
- Thermal Insulation (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、高熱にさらされる
部位に用いられる耐熱性、信頼性、耐久性に優れた機械
構造部品に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical structural part which is used for a part exposed to high heat and has excellent heat resistance, reliability and durability.
【０００２】[0002]
【従来の技術】内燃機関や燃焼等においては、燃焼火炎
等に直接さらされる耐熱部品が数多く使用されている。
例えば、自動車エンジンの部品においても、排気バル
ブ、排気ポート、燃料噴射ノズル等の部品は燃焼火炎に
さらされ或いは高温の燃焼ガスに直接触れるため、耐熱
金属材料を用いるか又は冷却が不可欠となっている。2. Description of the Related Art In an internal combustion engine, combustion and the like, many heat-resistant parts which are directly exposed to a combustion flame or the like are used.
For example, even in the parts of an automobile engine, parts such as an exhaust valve, an exhaust port, and a fuel injection nozzle are exposed to a combustion flame or come into direct contact with a high-temperature combustion gas. I have.
【０００３】近年、自動車エンジン等においては、燃焼
効率を上げるために燃焼温度の上昇が図られている。こ
れに伴って、高温に直接さらされる構造部品には高い耐
熱性が要求されるようになり、金属材料での対応が困難
に成りつつある。In recent years, in automobile engines and the like, the combustion temperature has been increased in order to increase the combustion efficiency. Along with this, structural parts that are directly exposed to high temperatures are required to have high heat resistance, and it is becoming difficult to deal with metallic materials.
【０００４】[0004]
【発明が解決しようとする課題】そこで、燃焼火炎や高
温の燃焼ガス等に直接さらされる構造部品を含めて、耐
熱性を要求される箇所の金属部品に断熱コーティングを
施したり、或はセラミックス断熱部品を取り付けること
が検討されている。Therefore, heat-insulating coatings may be applied to metal parts where heat resistance is required, including structural parts directly exposed to a combustion flame, high-temperature combustion gas, etc. Attachment of parts is being considered.
【０００５】しかし、断熱コーティングでは、そのコー
ティング時に金属部品に変質や寸法変化が起こりやすい
だけでなく、コーティングによって形成できる断熱層の
厚みが小さため、十分な断熱効果が得られないという問
題があった。また、セラミックス断熱部品の取り付けに
関しては、セラミックスの熱衝撃強度や疲労強度が低い
ため寿命が短い上に、金属部品に脱落しないように取り
付けることが難しいという問題があった。[0005] However, the heat insulating coating has a problem that not only the metal parts are easily deteriorated or changed in dimensions at the time of coating, but also a sufficient heat insulating effect cannot be obtained because the thickness of the heat insulating layer formed by the coating is small. Was. In addition, as for the attachment of the ceramic heat insulating part, there are problems that the thermal shock strength and the fatigue strength of the ceramic are low, so that the service life is short and it is difficult to mount the ceramic heat insulating part so that it does not fall off.
【０００６】本発明は、このような事情に鑑み、セラミ
ックス部材を金属部品と組み合わせることによって、金
属部品の変質や寸法変化を伴うことなく、十分な断熱効
果を容易に発揮でき、寿命が長く、信頼性の高い機械構
造部品を提供することを目的とする。In view of such circumstances, the present invention, by combining a ceramic member with a metal component, can easily exert a sufficient heat insulating effect without accompanying deterioration or dimensional change of the metal component, and has a long life. It is an object of the present invention to provide a highly reliable mechanical structure component.
【０００７】[0007]
【課題を解決するための手段】上記目的を達成するた
め、本発明が提供する機械構造部品は、金属部品と、該
金属部品の一部又は全てを覆うように取り付けられたセ
ラミックス断熱部材とからなり、該セラミックス断熱部
材の熱伝導率が５Ｗ／ｍ・Ｋ以下及び耐熱衝撃性が８０
０°Ｋ以上であって、該セラミックス断熱部材の熱膨張
率が前記金属部品の熱膨張率より小さいことを特徴とす
る。In order to achieve the above object, a mechanical structural part provided by the present invention comprises a metal part and a ceramic heat insulating member attached so as to cover a part or all of the metal part. The thermal insulation member has a thermal conductivity of 5 W / m · K or less and a thermal shock resistance of 80.
0 ° K or more, wherein the coefficient of thermal expansion of the ceramic heat insulating member is smaller than the coefficient of thermal expansion of the metal component.
【０００８】上記のセラミックス断熱部材で被覆した機
械構造部品においては、セラミックス断熱部材として、
曲げ強度が１００ＭＰａ以上及び気孔率が３０％以上の
窒化ケイ素を主成分とする多孔体を用いることが好まし
い。[0008] In the mechanical structural component covered with the above ceramic heat insulating member,
It is preferable to use a porous body mainly composed of silicon nitride having a bending strength of 100 MPa or more and a porosity of 30% or more.
【０００９】また、金属部品をセラミックス断熱部材で
覆う手段としては、セラミックス断熱部材を金属部品に
嵌着する方法が好ましく、その場合、使用温度における
金属部品とセラミックス断熱部材との嵌着箇所の寸法差
が、その使用温度における金属部品の寸法の±０.３％
以内であることが好ましく、±０.１％以内であること
が更に好ましい。The means for covering the metal component with the ceramic heat insulating member is preferably a method of fitting the ceramic heat insulating member to the metal component. In this case, the dimensions of the fitting portion between the metal component and the ceramic heat insulating member at the operating temperature are preferable. The difference is ± 0.3% of the dimension of the metal part at its operating temperature
Is preferably within ± 0.1%, and more preferably within ± 0.1%.
【００１０】[0010]
【発明の実施の形態】本発明においては、熱伝導率が５
Ｗ／ｍ・Ｋ以下及び耐熱衝撃性が８００°Ｋ以上であっ
て、熱膨張率が金属部品の熱膨張率より小さいセラミッ
クス断熱部材を用いて金属部品を覆うことによって、コ
ーティングのごとく金属部材の変質や寸法変化を起こす
ことがなく、十分な断熱効果を発揮でき、しかも寿命が
長く、信頼性の高い機械構造部品を提供することができ
る。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a thermal conductivity of 5
W / m · K or less, thermal shock resistance is 800 ° K or more, and the coefficient of thermal expansion is smaller than the coefficient of thermal expansion of the metal component. It is possible to provide a highly reliable mechanical structural component that can exhibit a sufficient heat insulating effect without causing deterioration or dimensional change, and has a long life.
【００１１】本発明が対象とする機械構造部品には、排
気バルブや排気ポート、燃料噴射ノズル等の自動車エン
ジン部品のほか、断熱を必要とするあらゆる金属部品が
含まれる。また、金属部品の材質も特に制限されず、鉄
系、アルミ系、チタン系、或いはＮｉ基耐熱合金など、
金属系の材料であればよい。The mechanical structural parts to which the present invention is directed include automobile engine parts such as exhaust valves, exhaust ports, fuel injection nozzles, and any other metal parts that require heat insulation. In addition, the material of the metal component is not particularly limited, such as iron-based, aluminum-based, titanium-based, or Ni-based heat-resistant alloy.
Any metal-based material may be used.
【００１２】金属部品を覆うように取り付けられるセラ
ミックス断熱部材は、高強度で、熱伝導率が低く且つ耐
熱衝撃性に優れ、信頼性が高いセラミックスで構成す
る。かかるセラミックスとしては、窒化ケイ素、コーデ
ィエライト等を挙げることができる。尚、断熱の機能の
みであれば、セラミックス繊維のプリフォームなども候
補となり得るが、使用中に繊維が脱離しやすい等の不都
合があるため好ましくない。The ceramic heat insulating member attached so as to cover the metal parts is made of ceramic having high strength, low thermal conductivity, excellent thermal shock resistance, and high reliability. Examples of such ceramics include silicon nitride and cordierite. In addition, if only the heat insulation function is provided, a preform of a ceramic fiber or the like may be a candidate, but it is not preferable because there is a disadvantage that the fiber is easily detached during use.
【００１３】本発明で用いるセラミックス断熱部材は、
熱伝導率が５Ｗ／ｍ・Ｋ以下であると共に、耐熱衝撃性
が８００°Ｋ以上であることが必要である。熱伝導率が
５Ｗ／ｍ・Ｋを越えると、断熱効果が低くなり、金属部
品の特性低下や変形等が生じるため好ましくない。ま
た、耐熱衝撃性が８００°Ｋ未満では、使用中の熱衝撃
により、即時破壊あるいは疲労破壊につながる。尚、耐
熱衝撃性とは、所定の温度に加熱したセラミックスを水
中に投入したとき、セラミックスに亀裂が発生し始める
加熱温度と水温との最小の温度差をもって示す。The ceramic heat insulating member used in the present invention comprises:
It is necessary that the thermal conductivity is 5 W / m · K or less and the thermal shock resistance is 800 ° K or more. When the thermal conductivity exceeds 5 W / m · K, the heat insulating effect is lowered, and the characteristics and deformation of the metal parts are undesirably generated. Further, when the thermal shock resistance is less than 800 ° K, a thermal shock during use leads to immediate destruction or fatigue destruction. The thermal shock resistance is represented by a minimum temperature difference between a heating temperature at which a ceramic starts to crack when a ceramic heated to a predetermined temperature is put into water and a water temperature.
【００１４】また、セラミックス断熱部材の熱膨張率
は、金属部品の熱膨張率よりも小さいことが必要であ
る。セラミックス断熱部材の熱膨張率が金属部品よりも
大きい場合には、室温で金属部品とセラミックス断熱部
材を組み合わせて高温下で用いたとき、温度上昇による
セラミックス断熱部材の熱膨張が金属部品のそれに比べ
て大きいため、両者の寸法差が大きくなる結果、使用中
にセラミックス断熱部材が金属部品から脱落し易くなる
からである。特にセラミックス断熱部材が金属部品の外
側に嵌着して組み立てられる場合、上記した両者の熱膨
張率の関係が重要になる。Further, the coefficient of thermal expansion of the ceramic heat insulating member needs to be smaller than the coefficient of thermal expansion of the metal component. When the coefficient of thermal expansion of the ceramic heat insulating member is larger than that of the metal part, when the metal part and the ceramic heat insulating member are combined at room temperature and used at a high temperature, the thermal expansion of the ceramic heat insulating member due to the temperature rise is larger than that of the metal part. This is because the size difference between the two becomes large, and as a result, the ceramic heat insulating member easily falls off from the metal part during use. In particular, when the ceramic heat insulating member is fitted to the outside of the metal component and assembled, the relationship between the above-described coefficients of thermal expansion becomes important.
【００１５】かかるセラミックス断熱部材を構成する好
ましいセラミックス材料として、Ｓｉ3Ｎ4を主成分とす
る多孔体がある。特に、曲げ強度が１００ＭＰａ以上で
且つ気孔率が３０％以上のＳｉ3Ｎ4系多孔体が好まし
い。曲げ強度が１００ＭＰａ未満では、多孔体の機械的
強度が低く、使用中や組立中に多孔体が破損し易いから
である。また、多孔体の気孔率が３０％未満では、熱伝
導率が高くなり、十分な断熱効果を得ることができな
い。As a preferable ceramic material constituting such a ceramic heat insulating member, there is a porous body mainly composed of Si 3 N 4 . In particular, a Si 3 N 4 based porous material having a bending strength of 100 MPa or more and a porosity of 30% or more is preferable. When the bending strength is less than 100 MPa, the mechanical strength of the porous body is low, and the porous body is easily damaged during use or assembly. On the other hand, if the porosity of the porous body is less than 30%, the thermal conductivity increases, and a sufficient heat insulating effect cannot be obtained.
【００１６】金属部品へのセラミックス断熱部材の取り
付け方法としては、適当な部材や治具等を用いて固定す
る方法もあるが、セラミックス断熱部材を金属部品の必
要箇所又は全体を覆うように嵌着する方法が好ましい。As a method of attaching the ceramic heat insulating member to the metal part, there is a method of fixing the ceramic heat insulating member using an appropriate member, a jig, or the like. However, the ceramic heat insulating member is fitted so as to cover a necessary portion or the entire metal part. Is preferred.
【００１７】上記嵌着によって取り付ける場合、使用温
度における金属部品とセラミックス断熱部材との嵌着箇
所における寸法差を、その使用温度における金属部品の
寸法の±０.３％以内とすることが好ましく、±０.１％
以内とすることが更に好ましい。上記寸法差が金属部品
の寸法の０.３％を越えて大きい場合には、嵌着されて
いるセラミックス断熱部材が金属部品から脱落しやすい
からである。また、上記寸法差が金属部品の寸法の０.
３％を越えて小さい場合は、加熱時の金属部品の変形に
セラミックス断熱部材が追随できず、セラミックス断熱
部材が破壊するからである。In the case where the fitting is performed by the fitting, it is preferable that a dimensional difference in a fitting portion between the metal component and the ceramic heat insulating member at a use temperature is within ± 0.3% of a dimension of the metal component at the use temperature. ± 0.1%
More preferably, it is within the range. If the dimensional difference is larger than 0.3% of the dimension of the metal component, the fitted ceramic heat insulating member is likely to fall off the metal component. In addition, the above-mentioned dimensional difference is 0.
If it is smaller than 3%, the ceramic heat insulating member cannot follow the deformation of the metal part during heating, and the ceramic heat insulating member is broken.
【００１８】[0018]
【実施例】実施例１ 図１に示すように、シリンダーブロック１内のピストン
２の上方に渦流室３を設けたディーゼルエンジンにおい
て、渦流室３に燃料を供給する耐熱鋼製の燃料噴射ノズ
ル４の先端部を外側から覆うように、下記表１に示す各
種セラミックスからなるセラミックス断熱部材５を嵌着
によって取り付けた。用いた各セラミックスの熱膨張率
は、いずれも燃料噴射ノズル４の耐熱鋼の熱膨張率より
も小さいものを選定した。尚、図中の６は、予熱のため
のグロープラグである。Embodiment 1 As shown in FIG. 1, in a diesel engine provided with a swirl chamber 3 above a piston 2 in a cylinder block 1, a fuel injection nozzle 4 made of heat-resistant steel for supplying fuel to the swirl chamber 3 A ceramic heat insulating member 5 made of various ceramics shown in Table 1 below was fitted by fitting so as to cover the front end portion from outside. The coefficient of thermal expansion of each of the ceramics used was selected to be smaller than the coefficient of thermal expansion of the heat-resistant steel of the fuel injection nozzle 4. Reference numeral 6 in the figure is a glow plug for preheating.
【００１９】これら各試料のディーゼルエジンを用い
て、通常状態に比べて火炎が燃料噴射ノズル４の先端に
近く、燃料噴射ノズル４の先端部が加熱される条件下で
エンジンを１００時間稼働させた。その後、燃料噴射ノ
ズル４の先端部又はセラミックス断熱部材５の状態を調
査した。Using the diesel engines of these samples, the engine was operated for 100 hours under the condition that the flame was closer to the tip of the fuel injection nozzle 4 and the tip of the fuel injection nozzle 4 was heated as compared with the normal state. . Thereafter, the state of the tip of the fuel injection nozzle 4 or the state of the ceramic heat insulating member 5 was examined.
【００２０】得られた結果を、下記表１に各セラミック
スの特性と併せて示した。また、下記表１には、使用温
度（８００℃）における燃料噴射ノズル４とセラミック
ス断熱部材５の嵌着箇所の寸法差を、同温度での燃料噴
射ノズル４の嵌着箇所の寸法に対する百分率（％）とし
て表示した。The results obtained are shown in Table 1 below together with the characteristics of each ceramic. Table 1 below shows the dimensional difference between the fitting location of the fuel injection nozzle 4 and the ceramic heat insulating member 5 at the operating temperature (800 ° C.) as a percentage (%) with respect to the dimension of the fitting location of the fuel injection nozzle 4 at the same temperature. %).
【００２１】[0021]
【表１】 断 熱 熱伝導率 耐熱衝撃 曲げ強度 気孔率 寸法差試料 部 材 (W/m・K) 性(°K) (MPa) (％) (％) 使用結果 1 なし − − − − − ノズル先端変形 2 Si3N4 20 700 800 1 ＋0.05 ノズル先端変形 3 Si3N4 4 1000 300 35 ＋0.05 良好 4 Si3N4 2 1000 150 55 −0.05 良好 5 Al2O3 15 200 500 1 ＋0.05 断熱部材割れ 6 Si3N4 4 1000 300 35 ＋0.5 断熱部材落下 7 SiC 15 800 150 30 ＋0.05 ノズル先端変形 8 Si3Ｎ4 4 1000 120 50 ＋0.15 良好 9 コーテ゛ィエライト 2 800 50 40 ＋0.05 良好 10 コーテ゛イエライト 2 800 50 40 −0.5 断熱部材割れ[Table 1] Thermal insulation Thermal conductivity Thermal shock Bending strength Porosity Dimensional difference Specimen material (W / m ・ K) Properties (° K) (MPa) (%) (%) Usage result 1 None----- Nozzle tip deformation 2 Si 3 N 4 20 700 800 1 +0.05 Nozzle tip deformation 3 Si 3 N 4 4 1000 300 35 +0.05 Good 4 Si 3 N 4 2 1000 150 55 −0.05 Good 5 Al 2 O 3 15 200 500 1 +0.05 Insulation member crack 6 Si 3 N 4 4 1000 300 35 +0.5 Insulation member fall 7 SiC 15 800 150 30 +0.05 Nozzle tip deformation 8 Si 3 N 4 4 1000 120 50 +0.15 Good 9 Coat Ellite 2 800 50 40 +0.05 Good 10 Coat Jeilite 2 800 50 40 −0.5 Insulation material crack
【００２２】以上の結果から分かるように、セラミック
ス断熱部材５を備えない試料１、及びセラミックス断熱
部材５の熱伝導率が５Ｗ／ｍ・Ｋを越える試料２、５、
７では、燃料噴射ノズル４の先端が変形し、特に耐熱衝
撃性が低い試料５ではセラミックス断熱部材５に割れが
発生した。As can be seen from the above results, the sample 1 without the ceramic heat insulating member 5 and the samples 2 and 5, in which the thermal conductivity of the ceramic heat insulating member 5 exceeds 5 W / m · K,
In No. 7, the tip of the fuel injection nozzle 4 was deformed, and cracks occurred in the ceramic heat insulating member 5 especially in the sample 5 having low thermal shock resistance.
【００２３】これに対して、熱伝導率が５Ｗ／ｍ・Ｋ以
下で且つ耐熱衝撃性が８００°Ｋ以上の試料３、４、
８、９では、セラミックス断熱部材５の割れや燃料噴射
ノズル４の先端の変形は発生せず、優れた断熱効果を発
揮していることが分かる。On the other hand, samples 3, 4, and 5 having a thermal conductivity of 5 W / m · K or less and a thermal shock resistance of 800 ° K or more.
In Nos. 8 and 9, no cracking of the ceramic heat insulating member 5 and no deformation of the tip of the fuel injection nozzle 4 occurred, indicating that an excellent heat insulating effect was exhibited.
【００２４】ただし、熱伝導率及び耐熱衝撃性が上記範
囲にあっても、セラミックス断熱部材５と燃料噴射ノズ
ル４の使用温度における寸法差が、燃料噴射ノズル４の
寸法の０.３％を越えて大きい試料６では、クリオアラ
ンスが大きくなり過ぎるため嵌着状態を維持できず、使
用中にセラミックス断熱部材５が落下した。また、この
寸法差が逆に０.３％を越えて小さい試料１０では、セ
ラミックス断熱部材５に割れが発生した。However, even if the thermal conductivity and the thermal shock resistance are in the above ranges, the difference in size between the ceramic heat insulating member 5 and the fuel injection nozzle 4 at the operating temperature exceeds 0.3% of the size of the fuel injection nozzle 4. In the case of the sample 6 having a large size, the fitted state could not be maintained because the cryoalance became too large, and the ceramic heat insulating member 5 dropped during use. On the other hand, in the sample 10 in which the dimensional difference was smaller than 0.3%, the ceramic heat insulating member 5 was cracked.
【００２５】実施例２ チタン合金製の燃料噴射ノズル４とアルミナ製のセラミ
ックス断熱部材５を用いた以外は実施例１と同様にし
て、燃料噴射ノズル４の先端部にセラミックス断熱部材
５を取り付け、同様の条件でエンジンを１００時間稼働
させた。 Example 2 A ceramic heat insulating member 5 was attached to the tip of the fuel injection nozzle 4 in the same manner as in Example 1 except that a fuel injection nozzle 4 made of titanium alloy and a ceramic heat insulating member 5 made of alumina were used. The engine was operated for 100 hours under the same conditions.
【００２６】その結果、アルミナの熱膨張率がチタン合
金の熱膨張率よりも大きいため、使用中にセラミックス
断熱部材５が燃料噴射ノズル４から脱落した。As a result, since the coefficient of thermal expansion of alumina was larger than the coefficient of thermal expansion of the titanium alloy, the ceramic heat insulating member 5 fell off from the fuel injection nozzle 4 during use.
【００２７】[0027]
【発明の効果】本発明によれば、特定の特性を持つセラ
ミックス断熱部材を金属部品と組み合わせて、金属部品
を覆うように取り付けることによって、金属部品の変質
や寸法変化を伴うことなく、十分な断熱効果を容易に発
揮できるので、寿命が長く且つ信頼性の高い機械構造部
品を提供することができる。According to the present invention, a ceramic heat insulating member having specific characteristics is combined with a metal component and attached so as to cover the metal component. Since the heat insulation effect can be easily exerted, a mechanical component having a long life and high reliability can be provided.
【００２８】従って、本発明の機械構造部品は、例えば
自動車エンジンの排気バルブ、排気ポート、燃料噴射ノ
ズル等のように、燃焼火炎にさらされ或いは高温の燃焼
ガスに直接触れる部品として最適であり、その優れた耐
熱性によりエンジンの燃焼効率の向上に寄与するものと
期待される。Therefore, the mechanical structural component of the present invention is most suitable as a component that is exposed to a combustion flame or directly comes into contact with high-temperature combustion gas, such as an exhaust valve, an exhaust port, a fuel injection nozzle, etc. of an automobile engine. Its excellent heat resistance is expected to contribute to the improvement of engine combustion efficiency.
【図１】燃料噴射ノズルの先端部にセラミックス断熱部
材を取り付けたディーゼルエンジンを示す概略の一部切
欠断面図である。FIG. 1 is a schematic partially cutaway sectional view showing a diesel engine in which a ceramic heat insulating member is attached to a tip portion of a fuel injection nozzle.
１ シリンダーブロック ２ ピストン ３ 渦流室 ４ 燃料噴射ノズル ５ セラミックス断熱部材 ６ グロープラグ Reference Signs List 1 cylinder block 2 piston 3 vortex chamber 4 fuel injection nozzle 5 ceramic heat insulating member 6 glow plug
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｆ０２Ｍ 53/04 Ｆ０２Ｍ 53/04 Ｐ 61/14 ３２０ 61/14 ３２０Ｐ Ｆ１６Ｌ 59/02 Ｆ１６Ｌ 59/02 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI F02M 53/04 F02M 53/04 P 61/14 320 61/14 320P F16L 59/02 F16L 59/02
Claims (4)
を覆うように取り付けられたセラミックス断熱部材とか
らなり、該セラミックス断熱部材の熱伝導率が５Ｗ／ｍ
・Ｋ以下及び耐熱衝撃性が８００°Ｋ以上であって、該
セラミックス断熱部材の熱膨張率が前記金属部品の熱膨
張率より小さいことを特徴とする、セラミックス断熱部
材で被覆した機械構造部品。1. A heat insulating member comprising a metal part and a ceramic heat insulating member attached so as to cover a part or all of the metal part, wherein the heat conductivity of the ceramic heat insulating member is 5 W / m.
-A mechanical structural component covered with a ceramic heat insulating member, wherein K is not more than K and thermal shock resistance is 800 ° K or more, and a coefficient of thermal expansion of the ceramic heat insulating member is smaller than a coefficient of thermal expansion of the metal part.
１００ＭＰａ以上及び気孔率３０％以上の窒化ケイ素を
主成分とする多孔体であることを特徴とする、請求項１
に記載のセラミックス断熱部材で被覆した機械構造部
品。2. The ceramic heat insulating member according to claim 1, wherein the ceramic heat insulating member is a porous body mainly composed of silicon nitride having a bending strength of 100 MPa or more and a porosity of 30% or more.
A machine structural part covered with the ceramic heat insulating member according to any one of the above.
嵌着してあり、使用温度における金属部品とセラミック
ス断熱部材との嵌着箇所の寸法差が、該使用温度におけ
る金属部品の寸法の±０.３％以内であることを特徴と
する、請求項１又は２に記載のセラミックス断熱部材で
被覆した機械構造部品。3. A ceramic heat insulating member is fitted to said metal component, and a difference in size of a fitting portion between the metal component and the ceramic heat insulating member at a use temperature is ± 0.2 of a dimension of the metal component at the use temperature. The mechanical structural component covered with the ceramic heat insulating member according to claim 1 or 2, wherein the mechanical structural component is within 3%.
ス断熱部材との嵌着箇所の寸法差が、該使用温度におけ
る金属部品の寸法の±０.１％以内であることを特徴と
する、請求項３に記載のセラミックス断熱部材で被覆し
た機械構造部品。4. The method according to claim 3, wherein a difference in size of the fitting portion between the metal component and the ceramic heat insulating member at the use temperature is within ± 0.1% of the size of the metal component at the use temperature. A machine structural part covered with the ceramic heat insulating member according to any one of the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17788997A JPH1121679A (en) | 1997-07-03 | 1997-07-03 | Machine structural parts covered with ceramic heat insulation material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17788997A JPH1121679A (en) | 1997-07-03 | 1997-07-03 | Machine structural parts covered with ceramic heat insulation material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1121679A true JPH1121679A (en) | 1999-01-26 |
Family
ID=16038841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17788997A Pending JPH1121679A (en) | 1997-07-03 | 1997-07-03 | Machine structural parts covered with ceramic heat insulation material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1121679A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1256712A3 (en) * | 2001-05-09 | 2003-07-16 | Caterpillar Inc. | Fuel injector with non-metallic tip insulator |
| AT512667A1 (en) * | 2012-04-05 | 2013-10-15 | Bosch Gmbh Robert | Injection nozzle for injecting media into a combustion chamber |
| CN105980675A (en) * | 2014-02-10 | 2016-09-28 | 日锻汽门株式会社 | Hollow poppet valve |
-
1997
- 1997-07-03 JP JP17788997A patent/JPH1121679A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1256712A3 (en) * | 2001-05-09 | 2003-07-16 | Caterpillar Inc. | Fuel injector with non-metallic tip insulator |
| US7070126B2 (en) | 2001-05-09 | 2006-07-04 | Caterpillar Inc. | Fuel injector with non-metallic tip insulator |
| AT512667A1 (en) * | 2012-04-05 | 2013-10-15 | Bosch Gmbh Robert | Injection nozzle for injecting media into a combustion chamber |
| AT512667B1 (en) * | 2012-04-05 | 2014-03-15 | Bosch Gmbh Robert | Injection nozzle for injecting media into a combustion chamber |
| CN105980675A (en) * | 2014-02-10 | 2016-09-28 | 日锻汽门株式会社 | Hollow poppet valve |
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