JPH0134662Y2 - - Google Patents
Info
- Publication number
- JPH0134662Y2 JPH0134662Y2 JP18723183U JP18723183U JPH0134662Y2 JP H0134662 Y2 JPH0134662 Y2 JP H0134662Y2 JP 18723183 U JP18723183 U JP 18723183U JP 18723183 U JP18723183 U JP 18723183U JP H0134662 Y2 JPH0134662 Y2 JP H0134662Y2
- Authority
- JP
- Japan
- Prior art keywords
- chamber
- ceramic
- subchamber
- ceramic material
- wall
- 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
Links
- 239000000919 ceramic Substances 0.000 claims description 29
- 229910010293 ceramic material Inorganic materials 0.000 claims description 29
- 238000002485 combustion reaction Methods 0.000 claims description 15
- 238000009413 insulation Methods 0.000 description 11
- 230000000694 effects Effects 0.000 description 10
- 239000000446 fuel Substances 0.000 description 10
- 230000008646 thermal stress Effects 0.000 description 9
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 239000010410 layer Substances 0.000 description 7
- 230000035882 stress Effects 0.000 description 6
- 239000002184 metal Substances 0.000 description 5
- 239000007789 gas Substances 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000009841 combustion method Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 239000000567 combustion gas Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910002077 partially stabilized zirconia Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Combustion Methods Of Internal-Combustion Engines (AREA)
Description
【考案の詳細な説明】
（産業上の利用分野）
本考案はエンジンの副室、特に周壁をセラミツ
ク材で形成した副室の構造に関する。[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to the structure of an engine subchamber, particularly the subchamber whose peripheral wall is formed of ceramic material.
（従来技術）
自動車用等のエンジンにおいては、燃焼室を主
燃焼室と該主燃焼室に噴孔を介して連通する副室
とで構成し、該副室内に燃料噴射ノズルから燃料
を噴射して着火させると共に、半燃焼状態のガス
を主燃焼室に噴出して拡散燃焼させるようにした
所謂副室式の燃焼方式が採用されることがある。(Prior art) In engines for automobiles, etc., the combustion chamber is composed of a main combustion chamber and an auxiliary chamber that communicates with the main combustion chamber through an injection hole, and fuel is injected into the auxiliary chamber from a fuel injection nozzle. In some cases, a so-called pre-chamber type combustion method is adopted, in which semi-combusted gas is injected into the main combustion chamber and diffused and combusted.
この燃焼方式においては、炭化水素等の未燃焼
ガスの排出を抑制する等のために上記副室内を高
温保持することが重要であり、そこで副室の周囲
を断熱性に優れたセラミツク材で形成することが
試みられている。 In this combustion method, it is important to maintain a high temperature inside the pre-chamber in order to suppress the emission of unburned gas such as hydrocarbons, so the pre-chamber is surrounded by a ceramic material with excellent heat insulation properties. An attempt is being made to do so.
然して、上記のように副室の周囲をセラミツク
材で形成するようにした場合、該セラミツク材
は、エンジン運転時に自らの断熱作用によつて副
室に面する内面側が高温、外面側が低温の状態と
なり、この内外面の温度差に基づいて内面側が圧
縮応力、外面側が引張応力となるような熱応力が
発生する。その場合に、上記内外面の温度差はセ
ラミツク材が厚くなるほど大きくなり、これに伴
つて発生する熱応力も大きくなる。ところが、セ
ラミツク材は断熱性に優れている反面、熱応力、
特に引張応力に対して脆く、そのため上記のよう
に副室をセラミツク材で形成した場合、引張応力
が作用するセラミツク材の外面側からクラツクが
発生し或いは破損するという問題があつた。 However, when the periphery of the pre-chamber is made of ceramic material as described above, the ceramic material maintains a state in which the inner surface facing the pre-chamber is high temperature and the outer surface side is low temperature due to its own insulating effect during engine operation. Based on this temperature difference between the inner and outer surfaces, thermal stress is generated such that the inner surface becomes compressive stress and the outer surface becomes tensile stress. In this case, the temperature difference between the inner and outer surfaces becomes larger as the ceramic material becomes thicker, and the thermal stress generated accordingly becomes larger. However, although ceramic materials have excellent heat insulation properties, they are susceptible to thermal stress,
It is especially brittle against tensile stress, and therefore, when the sub-chamber is made of ceramic material as described above, there is a problem that cracks occur or breakage occurs from the outer surface of the ceramic material on which tensile stress acts.
尚、副室の周囲をセラミツク材で覆うものとし
て、例えば実開昭54−45814号公報に開示された
ものがある。これはシリンダヘツドに設けられた
凹部に金属製のドームを装着することにより副室
を形成するようにしたもので、その場合にこの金
属製のドームの表裏面に無機質断熱膜（セラミツ
ク）を設けたものである。しかし、上記金属製の
ドームの表裏面に設けられる無機質断熱膜はいず
れも単層であると共に、上記ドームは金属製であ
つて断熱作用を有しないから、全体として副室に
対する断熱保温作用が十分でない。 Incidentally, as a device for covering the periphery of the subchamber with a ceramic material, for example, there is a device disclosed in Japanese Utility Model Application Publication No. 54-45814. This is a subchamber formed by attaching a metal dome to a recess provided in the cylinder head.In this case, an inorganic heat insulating film (ceramic) is installed on the front and back surfaces of this metal dome. It is something that However, since the inorganic heat insulating films provided on the front and back surfaces of the metal dome are both single-layered, and the dome is made of metal and has no heat insulation effect, the heat insulation effect for the subchamber as a whole is sufficient. Not.
（考案の目的）
本考案は、副室の内壁をセラミツク材で形成す
る場合における上記のような問題に対処するもの
で、上記副室内壁を薄肉のセラミツク材を複数枚
重ね合せてなる多層構造とすることにより、全体
として所要の断熱性を確保すると共に、セラミツ
ク材の各層については内外面の温度差ないし熱応
力を小さくすることにより、該セラミツク材の破
損やクラツクの発生を防止することを目的とす
る。(Purpose of the invention) The present invention deals with the above-mentioned problems when the inner wall of the sub-chamber is formed of ceramic material. By doing so, it is possible to ensure the required thermal insulation properties as a whole, and to reduce the temperature difference or thermal stress between the inner and outer surfaces of each layer of the ceramic material, thereby preventing damage or cracks in the ceramic material. purpose.
（考案の構成）
即ち、本考案に係るエンジンの副室構造は、主
燃焼室に噴孔を介して連通する副室の内壁を、薄
肉のセラミツク材を複数枚重ね合せることにより
多層構造としたセラミツク壁で構成するようにす
る。(Structure of the invention) In other words, the sub-chamber structure of the engine according to the present invention is such that the inner wall of the sub-chamber, which communicates with the main combustion chamber through the nozzle holes, has a multi-layered structure by stacking a plurality of thin ceramic materials. It should be constructed with ceramic walls.
このような構成によれば、上記多層構造を形成
する薄肉の各セラミツク材については、その内外
面の温度差が小さくなり、従つて該温度差に基づ
いて生ずる熱応力も小さくなる。これにより、多
層構造を形成する各セラミツク材の外面側に大き
な引張応力が生じることはない。 According to this configuration, the temperature difference between the inner and outer surfaces of each of the thin ceramic materials forming the multilayer structure is reduced, and therefore the thermal stress generated based on the temperature difference is also reduced. This prevents large tensile stress from occurring on the outer surface of each ceramic material forming the multilayer structure.
また、セラミツク壁は全体として所要の厚さが
確保されるから副室に対する断熱保温作用が低下
することはない。 Further, since the ceramic wall has the required thickness as a whole, the heat insulation effect on the auxiliary chamber does not deteriorate.
（実施例）
以下、本考案の実施例を図面に基づいて説明す
る。(Example) Hereinafter, an example of the present invention will be described based on the drawings.
第１図に示すように、エンジン１は燃焼室とし
て、シリンダブロツク２とシリンダヘツド３とピ
ストン４とによつて形成された主燃焼室５と、シ
リンダヘツド３内に設けられて噴孔６を介して主
燃焼室５に連通された副室７とを有する。この副
室７は、第２図に示すように予め組立て一体化さ
れた中空状の副室構造体８をシリンダヘツド３に
設けられた嵌合凹部９に嵌挿固着することにより
設けられるが、該構造体８は上部がドーム状とさ
れた金属製の保持部材１０と、該保持部材１０の
内側に焼きばめ等によつて嵌め込まれたセラミツ
ク壁１１とで構成され、該セラミツク壁１１の内
部が副室７とされている。そして、保持部材１０
の下端部に設けられた鍔部１０ａが上記シリンダ
ヘツド３における凹部９の入口部に圧入されるこ
とにより該シリンダヘツド３に固着されるように
なつている。 As shown in FIG. 1, an engine 1 has a main combustion chamber 5 formed by a cylinder block 2, a cylinder head 3, and a piston 4 as a combustion chamber, and a main combustion chamber 5 formed within the cylinder head 3 with nozzle holes 6. It has an auxiliary chamber 7 that communicates with the main combustion chamber 5 through the combustion chamber 5. The auxiliary chamber 7 is provided by fitting and fixing a hollow auxiliary chamber structure 8, which has been assembled and integrated in advance, into a fitting recess 9 provided in the cylinder head 3, as shown in FIG. The structure 8 is composed of a metal holding member 10 with a dome-shaped upper part, and a ceramic wall 11 fitted inside the holding member 10 by shrink fitting or the like. The interior is designated as sub-chamber 7. And the holding member 10
A flange 10a provided at the lower end of the cylinder head 3 is press-fitted into the entrance of a recess 9 in the cylinder head 3, thereby being fixed to the cylinder head 3.
また、シリンダヘツド３には副室７内に燃料を
噴射する燃料噴射ノズル１２と、エンジンの始動
時に該副室７内を予熱するグロープラグ１３とが
装着されていると共に、上記燃料噴射ノズル１２
から噴出される燃料の噴流を副室７内に導入する
ため、またグロープラグ１３の先端部を副室７内
に突入させるために、上記副室構造体８を構成す
る保持部材１０及びセラミツク壁１１の上部には
貫通孔１４，１５が形成されている。 Further, the cylinder head 3 is equipped with a fuel injection nozzle 12 for injecting fuel into the auxiliary chamber 7, and a glow plug 13 for preheating the inside of the auxiliary chamber 7 when the engine is started.
In order to introduce the jet of fuel ejected from the auxiliary chamber 7 into the auxiliary chamber 7 and to force the tip of the glow plug 13 into the auxiliary chamber 7, the holding member 10 and the ceramic wall that constitute the auxiliary chamber structure 8 are used. Through holes 14 and 15 are formed in the upper part of 11.
然して、上記副室構造体８における副室７の周
囲を構成するセラミツク壁１１は噴孔６が設けら
れた円板状の下部セラミツク壁１６と、燃料噴射
ノズル１２等が臨む貫通孔１４，１５が設けられ
且つ下面が開口した略球状の上部セラミツク壁１
７とから構成されていると共に、該上部セラミツ
ク壁１７が、例えばインジエクシヨン法やラバー
プレス法で形成された薄肉のセラミツク材１７1
〜１７4を重ね合せてなる多層構造とされている。 The ceramic wall 11 surrounding the sub-chamber 7 in the sub-chamber structure 8 includes a disk-shaped lower ceramic wall 16 in which the injection hole 6 is provided, and through holes 14 and 15 from which the fuel injection nozzle 12 and the like face. A substantially spherical upper ceramic wall 1 having an open bottom surface and having a
7, and the upper ceramic wall 17 is made of a thin ceramic material 17 1 formed by, for example, an injection method or a rubber press method.
It has a multi-layered structure made by stacking ~17 4 layers.
ここで、この実施例においては、上部セラミツ
ク壁１７は４層構造とされ、全体として副室７に
対する所要の断熱保温作用が得られる厚さとされ
ていると共に、最も内側の層を形成するセラミツ
ク材１７1には耐熱性に優れた窒化珪素が、他の
層を形成するセラミツク材１７2，１７3，１７4
には断熱性に優れたジルコニア（部分安定化ジル
コニア）が用いられている。一方、高温の燃焼ガ
スと低温の新気とに交互に曝される下部セラミツ
ク壁１６にはサーマルシヨツクに強い窒化珪素が
用いられている。 Here, in this embodiment, the upper ceramic wall 17 has a four-layer structure, and has a thickness that provides the necessary heat insulation effect for the subchamber 7 as a whole, and the ceramic material forming the innermost layer 17 1 is made of silicon nitride with excellent heat resistance, and the other layers are made of ceramic materials 17 2 , 17 3 , 17 4
Zirconia (partially stabilized zirconia), which has excellent heat insulation properties, is used. On the other hand, silicon nitride, which is resistant to thermal shock, is used for the lower ceramic wall 16, which is exposed alternately to high-temperature combustion gas and low-temperature fresh air.
また、上部セラミツク壁１７は製造上の理由で
ドーム状の上半部１７′と環状の下半部１７″とに
分割され、夫々が複数の薄肉セラミツク材１７1
〜１７4により形成されていると共に、上半部１
７″に設けられる貫通孔１４，１５の周囲及び下
半部１７″の下端部が結束リング１８…１８で結
束され、該部分からの破損が防止されている。更
に、下すぼみとなつている下半部１７″の外周に
生じる空間が断面楔状の補助セラミツク材１９で
埋められている。 Further, for manufacturing reasons, the upper ceramic wall 17 is divided into a dome-shaped upper half 17' and an annular lower half 17'', each of which is made of a plurality of thin ceramic materials 171.
~17 4 and the upper half 1
The periphery of the through holes 14 and 15 provided in the 7'' and the lower end of the lower half 17'' are bound by binding rings 18...18 to prevent damage from these parts. Furthermore, the space created around the outer periphery of the lower half 17'', which has a downward depression, is filled with an auxiliary ceramic material 19 having a wedge-shaped cross section.
上記の構成によれば、エンジン１の運転時に副
室７内には圧縮行程時に主燃焼室５から噴孔６を
通つて空気が押し込められて渦流が形成されると
共に、圧縮行程から膨張行程に移行する際の所定
時期に該副室７内に燃料噴射ノズル１２から燃料
が噴射される。この燃料は副室７内で直ちに着火
されると共に、半燃焼状態のガスとなつて上記噴
孔６から主燃焼室５に噴出され、該主燃焼室５に
おいて更に燃焼してピストン４を押し下げる。そ
の場合に、上記副室７はその全周囲を断熱性に優
れたセラミツク壁１１で覆われているから、内部
が高温に保持されて上記燃料の着火、燃焼が良好
に行われる。 According to the above configuration, when the engine 1 is operating, air is forced into the auxiliary chamber 7 from the main combustion chamber 5 through the nozzle holes 6 during the compression stroke, forming a vortex flow, and from the compression stroke to the expansion stroke. Fuel is injected from the fuel injection nozzle 12 into the auxiliary chamber 7 at a predetermined time during the transition. This fuel is immediately ignited in the auxiliary chamber 7, becomes semi-combusted gas, and is injected from the nozzle hole 6 into the main combustion chamber 5, where it is further combusted and pushes down the piston 4. In this case, since the auxiliary chamber 7 is entirely covered with a ceramic wall 11 having excellent heat insulation properties, the inside is maintained at a high temperature, and the fuel can be ignited and burned well.
然して、副室７の周囲を形成するセラミツク壁
１１は自らの断熱作用によつて副室７側の内面が
高温、外面が低温の状態となつて、内外面間に大
きな温度差が生じる。この温度差は副室７に対す
る保温効果を高めるべくセラミツク壁１１を厚く
するほど大きくなり、セラミツク壁が単層の場合
は、これに伴つて該セラミツク壁に生じる熱応力
も大きくなる。そして、特に大きな熱応力が生じ
た場合、該応力によつてセラミツク壁が破損した
りクラツクが生じたりする。 However, due to its own heat insulating effect, the ceramic wall 11 forming the periphery of the auxiliary chamber 7 has a high temperature on its inner surface on the side of the auxiliary chamber 7 and a low temperature on its outer surface, resulting in a large temperature difference between the inner and outer surfaces. This temperature difference becomes larger as the ceramic wall 11 is made thicker to enhance the heat retention effect on the subchamber 7, and when the ceramic wall is a single layer, the thermal stress generated in the ceramic wall also becomes larger. If particularly large thermal stress occurs, the ceramic wall may be damaged or cracked due to the stress.
しかし、副室７の周囲を形成する上部セラミツ
ク壁１７は薄肉のセラミツク材１７1，１７2…を
複数枚重ねることにより多層構造とされているの
で、最内層のセラミツク材１７1の内面と最外層
のセラミツク材１７4の外面との間には大きな温
度差が生じるが、夫々の層については各セラミツ
ク材１７1，１７2…の内外面の温度差は小さく、
従つて各セラミツク材１７1，１７2…に生じる熱
応力も小さくなる。これにより上部セラミツク壁
１７に破損やクラツクが発生するのが防止される
ことになる。 However, since the upper ceramic wall 17 forming the periphery of the subchamber 7 has a multilayer structure by stacking a plurality of thin ceramic materials 17 1 , 17 2 . A large temperature difference occurs between the outer surface of the ceramic material 17 4 of the outer layer, but the temperature difference between the inner and outer surfaces of each ceramic material 17 1 , 17 2 . . . is small for each layer.
Therefore, the thermal stress generated in each ceramic material 17 1 , 17 2 . . . is also reduced. This prevents damage or cracks from occurring in the upper ceramic wall 17.
また、上部セラミツク壁１７は全体として所要
の厚さが確保され、副室７に対する十分な断熱保
温効果が得られることになる。 Further, the upper ceramic wall 17 has a required thickness as a whole, and a sufficient heat insulation effect for the subchamber 7 can be obtained.
（考案の効果）
以上のように本考案によれば、主燃焼室に噴孔
を介して連通する副室の周囲をセラミツク壁で構
成する副室構造において、該セラミツク壁を薄肉
のセラミツク材を複数枚重ね合せた多層構造とす
る構成としたから、副室に対する所要の断熱保温
効果が得られると共に、該セラミツク壁を構成す
る各セラミツク材についてはその内外面間の温度
差が小さくなり、これに伴つて各セラミツク材に
生ずる熱応力も小さくなる。これにより、この種
の副室構造におけるセラミツク壁の破損やクラツ
クの発生が防止されることになる。(Effects of the invention) As described above, according to the invention, in the subchamber structure in which the periphery of the subchamber that communicates with the main combustion chamber through the nozzle hole is constructed of a ceramic wall, the ceramic wall is made of a thin ceramic material. Since it has a multi-layered structure with multiple layers stacked on top of each other, it is possible to obtain the necessary heat insulation effect for the subchamber, and the temperature difference between the inner and outer surfaces of each ceramic material constituting the ceramic wall is reduced. As a result, the thermal stress generated in each ceramic material also decreases. This prevents damage to the ceramic wall and occurrence of cracks in this type of subchamber structure.
図面は本考案の実施例を示すもので、第１図は
エンジンにおける副室周辺の縦断面図、第２図は
副室構造体の一部縦断斜視図である。
１……エンジン、５……主燃焼室、６……噴
孔、７……副室、１１，１７……セラミツク壁
（上部セラミツク壁）、１７1〜１７4……薄肉のセ
ラミツク材。
The drawings show an embodiment of the present invention, and FIG. 1 is a vertical sectional view of the vicinity of the subchamber in an engine, and FIG. 2 is a partial longitudinal sectional perspective view of the subchamber structure. DESCRIPTION OF SYMBOLS 1...Engine, 5...Main combustion chamber, 6...Nozzle hole, 7...Subchamber, 11, 17...Ceramic wall (upper ceramic wall), 171 to 174 ...Thin ceramic material.
Claims (1)
セラミツク壁で構成するエンジンの副室構造であ
つて、上記セラミツク壁が薄肉のセラミツク材を
複数枚重ね合せてなる多層構造とされていること
を特徴とするエンジンの副室構造。 An engine sub-chamber structure in which a sub-chamber that communicates with the main combustion chamber via a nozzle hole is surrounded by a ceramic wall, and the ceramic wall has a multi-layered structure made by stacking a plurality of thin ceramic materials. The subchamber structure of an engine is characterized by a
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18723183U JPS6095134U (en) | 1983-12-02 | 1983-12-02 | Engine pre-chamber structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18723183U JPS6095134U (en) | 1983-12-02 | 1983-12-02 | Engine pre-chamber structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6095134U JPS6095134U (en) | 1985-06-28 |
| JPH0134662Y2 true JPH0134662Y2 (en) | 1989-10-23 |
Family
ID=30404206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18723183U Granted JPS6095134U (en) | 1983-12-02 | 1983-12-02 | Engine pre-chamber structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6095134U (en) |
-
1983
- 1983-12-02 JP JP18723183U patent/JPS6095134U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6095134U (en) | 1985-06-28 |
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