JPH01318750A - Structure of insulated piston - Google Patents
Structure of insulated pistonInfo
- Publication number
- JPH01318750A JPH01318750A JP14835688A JP14835688A JPH01318750A JP H01318750 A JPH01318750 A JP H01318750A JP 14835688 A JP14835688 A JP 14835688A JP 14835688 A JP14835688 A JP 14835688A JP H01318750 A JPH01318750 A JP H01318750A
- Authority
- JP
- Japan
- Prior art keywords
- piston
- heat insulating
- heat
- thin plate
- piston head
- 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.)
- Granted
Links
- 239000011810 insulating material Substances 0.000 claims abstract description 22
- 239000000919 ceramic Substances 0.000 claims abstract description 15
- 238000003825 pressing Methods 0.000 claims description 10
- 230000002093 peripheral effect Effects 0.000 claims description 8
- 238000009413 insulation Methods 0.000 abstract description 4
- 238000000034 method Methods 0.000 abstract description 4
- 239000003566 sealing material Substances 0.000 abstract description 2
- 238000002485 combustion reaction Methods 0.000 description 20
- 229910010293 ceramic material Inorganic materials 0.000 description 13
- 239000000567 combustion gas Substances 0.000 description 9
- 229910052581 Si3N4 Inorganic materials 0.000 description 6
- NJLLQSBAHIKGKF-UHFFFAOYSA-N dipotassium dioxido(oxo)titanium Chemical compound [K+].[K+].[O-][Ti]([O-])=O NJLLQSBAHIKGKF-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 6
- 239000000835 fiber Substances 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
- 238000004880 explosion Methods 0.000 description 4
- 239000003779 heat-resistant material Substances 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005304 joining Methods 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 2
- UUTKICFRNVKFRG-WDSKDSINSA-N (4R)-3-[oxo-[(2S)-5-oxo-2-pyrrolidinyl]methyl]-4-thiazolidinecarboxylic acid Chemical compound OC(=O)[C@@H]1CSCN1C(=O)[C@H]1NC(=O)CC1 UUTKICFRNVKFRG-WDSKDSINSA-N 0.000 description 1
- 244000108452 Litchi chinensis Species 0.000 description 1
- 235000015742 Nephelium litchi Nutrition 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910000623 nickel–chromium alloy Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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
- F02F3/10—Pistons having surface coverings
- F02F3/12—Pistons having surface coverings on piston heads
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
- Combustion Methods Of Internal-Combustion Engines (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Abstract
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、断熱ピストンの構造に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a heat insulating piston.
従来、セラミック材料を断熱材又は耐熱材として利用し
た断熱ピストン等のエンジン部材は、例えば、特開昭６
１−６６８４８号公報に開示されている。該特開昭６１
−６６８４８号公報に開示された断熱ピストンについて
、第４図を参照して概説する。第４図において、断熱ピ
ストンが符号３０によって全体的に示されている。この
断熱ピストン３０については、セラミックスから成るピ
ストン冠部３１と対向するスカート部３２の端面にセラ
ミックスから成るコーティング層３３を備えたものであ
る。また、ピストン冠部３１には燃焼室３４が形成され
、ピストン冠部３１とスカート部３２とはガスケット３
６を介してポルト３５によって結合されている。更に、
ピストン冠部３１とスカート部３２との間にはシールリ
ング３７が配置されている。Conventionally, engine parts such as heat-insulating pistons using ceramic materials as heat-insulating or heat-resistant materials have been developed, for example, in Japanese Unexamined Patent Publication No. 6
It is disclosed in Japanese Patent No. 1-66848. JP-A-61
The heat insulating piston disclosed in Japanese Patent No. 66848 will be summarized with reference to FIG. In FIG. 4, an insulated piston is indicated generally by the numeral 30. This heat-insulating piston 30 is provided with a coating layer 33 made of ceramics on the end face of a skirt portion 32 facing a piston crown portion 31 made of ceramics. Further, a combustion chamber 34 is formed in the piston crown 31, and the piston crown 31 and the skirt 32 are connected to the gasket 3.
6 and connected by port 35. Furthermore,
A seal ring 37 is arranged between the piston crown portion 31 and the skirt portion 32.
しかしながら、上記のようなセラミック材料を断熱材又
は耐熱材として利用するピストン等の断熱エンジン部材
において、断熱特性を十分に得ることは極めて困難なこ
とである。セラミック材料が燃焼室側の高温に晒される
状態であり、そのため熱シｇ７りを受け、セラミック材
料の強度上の問題がある。また、断熱のため壁面のセラ
ミック材料の厚さを厚くすると、熱容量が大きくなる。However, it is extremely difficult to obtain sufficient heat-insulating properties in heat-insulating engine members such as pistons that utilize the above-mentioned ceramic materials as heat-insulating or heat-resistant materials. This is a state in which the ceramic material is exposed to high temperatures on the side of the combustion chamber, and is therefore subject to heat shrinkage, which poses problems in terms of the strength of the ceramic material. In addition, increasing the thickness of the ceramic material on the wall for heat insulation increases the heat capacity.
そのため吸入工程時に吸入空気が燃焼室から多く受熱し
て高温になり、その熱が吸気に影響し、吸入効率が低下
して空気が吸入されなくなるという現象が生じるという
問題がある０例えば、前掲特開昭６１−６６８４８号公
報に開示された断熱ピストン３０については、セラミッ
クスから成るピストン冠部３１の厚さは厚く構成されて
おり、上記と同様の問題点を有している。Therefore, during the intake process, the intake air receives a lot of heat from the combustion chamber and becomes high temperature, and this heat affects the intake air, reducing the intake efficiency and causing the phenomenon that no air is taken in. In the heat-insulating piston 30 disclosed in Japanese Patent Publication No. 61-66848, the piston crown 31 made of ceramic is thick and has the same problem as above.
ところで、シリンダライナ上部を一体構造に構成したシ
リンダヘッドにのみ水ジャケットを設け、シリンダボデ
ィ側から水ジャケットを排除して冷却系を縮小する場合
に、ピストンを断熱構造に構成することが好ましいが、
その場合に、シリンダライナが配置されたシリンダボデ
ィには水ジャケットが無いから、ピストン及びピストン
リングとシリンダライナとの摺動特性を向上させるため
、ピストンヘッド部で受熱した熱エネルギーがシリンダ
ライナ及びビストンスカート部へ少しでも熱伝導されな
いように構成し、適度な温度に維持されるようにしなけ
ればならないという課題がある。Incidentally, when a water jacket is provided only on a cylinder head in which the upper part of the cylinder liner is configured as an integral structure, and the water jacket is removed from the cylinder body side to reduce the cooling system, it is preferable to configure the piston with an adiabatic structure.
In this case, since the cylinder body in which the cylinder liner is arranged does not have a water jacket, the heat energy received at the piston head is transferred to the cylinder liner and piston in order to improve the sliding characteristics between the piston and piston rings and the cylinder liner. The problem is that it must be constructed so that even the slightest amount of heat is not conducted to the skirt portion, and the temperature must be maintained at an appropriate level.
この発明の目的は、上記の課題を解決することであり、
ピストンヘッドを構成する燃焼室に晒される面となる薄
板部材で受熱した熱をビストンスカート部へ熱伝導され
ないように構成し、シリンダライナ下部の冷却を不要に
し、また極めて高度の断熱性を得ると共に、燃焼ガスに
晒されて高温になる燃焼室側に面するピストンヘッドの
表面部の熱容量を可及的に小さく構成し、吸入効率及び
サイクル効率を向上させ、しかも熱ショックを受けても
強度上の問題が生じることなく、耐熱性、耐腐食性、耐
変形性を向上させ、しかも安定した取付状態を得ること
ができ、更に爆発時にピストンヘッドに作用する圧力を
好ましい状態で受けることができる構造に構成した断熱
ピストンの構造を提供することである。The purpose of this invention is to solve the above problems,
The piston head is configured so that the heat received by the thin plate member, which is the surface exposed to the combustion chamber, is not conducted to the piston skirt, eliminating the need for cooling the lower part of the cylinder liner, and achieving an extremely high level of heat insulation. , the heat capacity of the surface of the piston head facing the combustion chamber side, which is exposed to combustion gas and becomes high temperature, is configured to be as small as possible to improve suction efficiency and cycle efficiency, and to maintain its strength even when subjected to thermal shock. A structure that improves heat resistance, corrosion resistance, and deformation resistance without causing any problems, provides a stable mounting condition, and can receive the pressure that acts on the piston head in a favorable manner during an explosion. It is an object of the present invention to provide a structure of an adiabatic piston configured as follows.
この発明は、上記の問題点を解消し、上記の目的を達成
するために、次のように構成されている。In order to solve the above problems and achieve the above objects, the present invention is configured as follows.
即ち、この発明は、外周部にセラミック製筒部材を接合
したピストンヘッド部を断熱層を介してビストンスカー
ト部に固定し、前記筒部材に形成した押圧部分で断熱ガ
スケットを介してセラミック製薄板部材の周囲部分を押
圧することによって前記ピストンヘッド部の上面に断熱
材を介して前記薄板部材を固定したことを特徴とする断
熱ピストンの構造に関する。That is, in this invention, a piston head portion having a ceramic cylindrical member joined to the outer circumferential portion is fixed to a piston skirt portion via a heat insulating layer, and a ceramic thin plate member is attached to the piston head portion through a heat insulating gasket at a pressing portion formed on the cylindrical member. The present invention relates to a structure of a heat insulating piston, characterized in that the thin plate member is fixed to the upper surface of the piston head via a heat insulating material by pressing the peripheral portion of the piston.
また、前記筒部材の内面と前記薄板部材の表面との間に
は隙間が形成されていることを特徴とする。Further, a gap is formed between the inner surface of the cylindrical member and the surface of the thin plate member.
この発明による断熱ピストンの構造は、以上のように構
成されており、次のように作用する。即ち、この断熱ピ
ストンの構造は、外周部にセラミック製筒部材を接合し
たピストンヘッド部を断熱層を介してビストンスカート
部に固定し、前記筒部材に形成した押圧部分で断熱ガス
ケットを介してセラミック製薄板部材の周囲部分を押圧
して前記ピストンヘッド部の上面に断熱材を介して前記
薄板部材を固定したので、燃焼室に晒される面となる前
記薄板部材で受熱した熱は前記断熱ガスケットによって
断熱され、前記薄板部材から外周部に配置された前記筒
部材へは熱伝導されることがなく、しかも前記薄板部材
と前記ピストンヘッド部との間には前記断熱材によって
同様に断熱されているので、中間部に位置する前記ピス
トンヘッド部及び前記ビストンスカート部への熱伝導も
ない、また、燃焼ガスに晒されて高温になるピストンヘ
ッドの表面部に位置する前記薄板部材の厚さを可及的に
薄く構成でき、その熱容量を可及的に小さく構成するこ
とができ、吸入効率及びサイクル効率を向上させる。即
ち、前記薄板部材の厚さを薄く構成する程、ガス温度へ
の追従性がよくなり、そして、燃焼室内の高温時と低温
時との壁温振幅は厚さが厚い場合に比較して大きくなり
、結果的に燃焼ガスと前記薄板部材との温度差が小さく
なり、熱伝達量が減少するため、吸入空気の受熱を減少
させる。The structure of the heat insulating piston according to the present invention is constructed as described above, and operates as follows. That is, the structure of this heat-insulating piston is such that a piston head part with a ceramic cylinder member joined to the outer periphery is fixed to the piston skirt part through a heat-insulating layer, and a ceramic cylinder is connected to the piston head part through a heat-insulating gasket at the pressing part formed on the cylinder member. Since the peripheral portion of the thin plate member is pressed and the thin plate member is fixed to the upper surface of the piston head via the heat insulating material, the heat received by the thin plate member, which is the surface exposed to the combustion chamber, is transferred by the heat insulating gasket. The thin plate member is insulated, and no heat is conducted from the thin plate member to the cylindrical member disposed on the outer periphery, and the space between the thin plate member and the piston head is similarly insulated by the heat insulating material. Therefore, there is no heat conduction to the piston head part and the piston skirt part located in the middle part, and the thickness of the thin plate member located on the surface part of the piston head which is exposed to combustion gas and becomes high temperature can be reduced. It can be made as thin as possible, and its heat capacity can be made as small as possible, improving suction efficiency and cycle efficiency. In other words, the thinner the thin plate member is, the better the ability to follow the gas temperature, and the wall temperature amplitude between high and low temperatures in the combustion chamber is larger than when the thin plate member is thicker. As a result, the temperature difference between the combustion gas and the thin plate member becomes smaller, and the amount of heat transfer is reduced, so that the heat received by the intake air is reduced.
また、…■記筒部材の内面と前記薄板部材の外面との間
には隙間が形成されているので、前記薄板部材から前記
筒部材への熱伝導は遮断される。Further, since a gap is formed between the inner surface of the cylindrical member and the outer surface of the thin plate member, heat conduction from the thin plate member to the cylindrical member is blocked.
以下、図面を参照して、この発明による断熱ピストンの
構造の実施例を詳述する。Hereinafter, embodiments of the structure of the heat insulating piston according to the present invention will be described in detail with reference to the drawings.
第１図はこの発明による断熱ピストンの構造の一実施例
を示す断面図、及び第２図は第１図の符号Ａの部分の拡
大断面図である。この断熱ピストンは、主として、ピス
トンヘッド部１、ビストンスカート部２、断熱材３、薄
板部材５、筒部材６及び断熱ガスケット７から構成され
ている。ピストンヘッド部ｌは中央部に取付ボス部１０
を備えており、また、ビストンスカート部２は、金属材
から成り、ピストンリング溝２３及びピストンピン孔１
４を備えていると共に上端壁部４を備えている。ビスト
ンスカート部２の上端壁部４の中央部には、ピストンヘ
ッド部ｌを取付けるため、取付孔１６が形成されている
。従って、ピストンヘッド部ｌの取付ボス部１０をビス
トンスカート部２の取付孔２１に嵌合し、取付ボス部１
０の外周面に形成した嵌合溝と取付孔２１の内周面に形
成した嵌合溝とに跨がって金属リング１７をメタルフロ
ー即ち変形収容することによって、ビストンスカート部
２にピストンヘッド部ｌを固定することができる。この
場合に、ピストンヘッド部ｌの下面２４とビストンスカ
ート部２の上端壁部４の上面２５との間には、断熱材で
ある断熱ガスケラ）１１及び外周部に断熱シール材２２
が介在されると共に、断熱空気層１６が形成されている
。FIG. 1 is a cross-sectional view showing an embodiment of the structure of a heat-insulating piston according to the present invention, and FIG. 2 is an enlarged cross-sectional view of a portion indicated by the symbol A in FIG. This heat insulating piston mainly includes a piston head portion 1, a piston skirt portion 2, a heat insulating material 3, a thin plate member 5, a cylindrical member 6, and a heat insulating gasket 7. The piston head part l has a mounting boss part 10 in the center.
The piston skirt portion 2 is made of a metal material and has a piston ring groove 23 and a piston pin hole 1.
4 and an upper end wall portion 4. A mounting hole 16 is formed in the center of the upper end wall portion 4 of the piston skirt portion 2 for mounting the piston head portion l. Therefore, the mounting boss part 10 of the piston head part l is fitted into the mounting hole 21 of the piston skirt part 2, and the mounting boss part 1
The piston head is attached to the piston skirt part 2 by metal flow, that is, by deforming and housing the metal ring 17 across the fitting groove formed on the outer circumferential surface of the piston 0 and the fitting groove formed on the inner circumferential surface of the mounting hole 21. Part l can be fixed. In this case, between the lower surface 24 of the piston head portion l and the upper surface 25 of the upper end wall portion 4 of the piston skirt portion 2, there is a heat insulating gas keratinium 11 which is a heat insulating material and a heat insulating sealing material 22 on the outer periphery.
is interposed therebetween, and an insulating air layer 16 is formed.
また、ピストンへアト部ｌの燃焼室１５側の構造につい
ては、ピストンヘッドそのものには燃焼室が形成されて
おらず、ピストンヘッド部１の燃焼室１５側の面及びピ
ストンヘッド部１に断熱材３を介して取付けられた薄板
部材５は、、フラットな形状に構成されている。従って
、燃焼ガスに晒される面が上記のようなフラットな形状
のピストンでは、燃焼室１５をシリンダヘッド側に形成
することが好ましいものである。ピストンヘッド部１の
上面１８全体に渡って断熱材３が配置されており、該断
熱材３の上面には窒化珪素等のセラミック材から成る薄
板部材５が配置されている。この薄板部材５は燃焼室１
５側に面し、燃焼ガスに晒される面となる。そこで、薄
板部材５については、熱容量を小さくするためできるだ
け薄く形成したものである。この薄板部材５は、窒化珪
素、炭化珪素等のセラミック材料から平らな円板状に形
成され、例えば、厚さ約１＋ｓ−前後、或いはｌｓｍ以
下に製作されている。また、ピストンヘッド部１の外周
面１３に接合される筒部材６は、窒化珪素（ＳｉｓＮａ
）等のセラミック材から製作されている。この筒部材
６は、断面り字型であり、上端部に半径方向内向きに伸
びる押圧部分となるフランジ部１２を備えている。この
フランジ部１２は、断熱ガスケット７を介して薄板部材
５の周囲部分を押圧する押圧部分である。断熱ガスケッ
ト７については、第２図に示すように、チタン酸カリウ
ムウィスカー、或いはチタン酸カリウムウィスカーとア
ルミナファイバーとの混合材１９をステンレススチール
の薄板９で包み込んだものである。In addition, regarding the structure of the combustion chamber 15 side of the rear part l of the piston, no combustion chamber is formed in the piston head itself, and there is a heat insulating material on the surface of the piston head part 1 on the combustion chamber 15 side and the piston head part 1. The thin plate member 5 attached via 3 has a flat shape. Therefore, in a piston whose surface exposed to combustion gas is flat as described above, it is preferable to form the combustion chamber 15 on the cylinder head side. A heat insulating material 3 is disposed over the entire upper surface 18 of the piston head portion 1, and a thin plate member 5 made of a ceramic material such as silicon nitride is disposed on the upper surface of the heat insulating material 3. This thin plate member 5 is the combustion chamber 1
This is the surface that faces the 5 side and is exposed to combustion gas. Therefore, the thin plate member 5 is formed as thin as possible in order to reduce the heat capacity. The thin plate member 5 is formed into a flat disk shape from a ceramic material such as silicon nitride or silicon carbide, and is manufactured to have a thickness of, for example, about 1+s- or less than lsm. Further, the cylindrical member 6 joined to the outer circumferential surface 13 of the piston head portion 1 is made of silicon nitride (SisNa
) and other ceramic materials. The cylindrical member 6 has a cross-sectional shape, and is provided with a flange portion 12 at its upper end that serves as a pressing portion that extends radially inward. This flange portion 12 is a pressing portion that presses the peripheral portion of the thin plate member 5 via the heat insulating gasket 7. As shown in FIG. 2, the heat insulating gasket 7 is made by wrapping potassium titanate whiskers or a mixture 19 of potassium titanate whiskers and alumina fibers in a thin stainless steel plate 9.
また、燃焼室１５にし−む筒部材６のフランジ部１２の
長さは、断熱ガスケアドアを押圧して薄板部材５をピス
トン−、アト部ｌに対して固定できる程度でよく、でき
るだけ短い方が好ましいものである。一般に、エンジン
の燃焼室１５では、シリンダライチ周面付近はガス流速
が小さく熱伝導量は小さいもので、周囲部分の温度は低
く、中央部分の温度は高くなっている。従って、筒部材
６が位置する燃焼室１５に面する周囲部分を、できるだ
け小さな面積にすることによって、その部分の熱伝導を
小さくすることができる。The length of the flange portion 12 of the cylindrical member 6 connected to the combustion chamber 15 may be such that the thin plate member 5 can be fixed to the piston and rear portion l by pressing the insulating gas care door, and it is preferable that the length be as short as possible. It is something. Generally, in the combustion chamber 15 of the engine, the gas flow rate is low near the cylinder lychee peripheral surface and the amount of heat conduction is small, the temperature of the surrounding portion is low and the temperature of the central portion is high. Therefore, by making the area of the peripheral portion facing the combustion chamber 15 where the cylindrical member 6 is located as small as possible, heat conduction in that portion can be reduced.
ところで、これらの部材の取付は工程として、例えば、
ピストンヘッド部ｌの上面に断熱材３、薄板部材５及び
断熱ガスケット７を順次重ね、次いで筒部材６のフラン
ジ部１２を断熱ガスケット７上に載せ、薄板部材５及び
断熱材３を筒部材６内に収容した状態で、筒部材６の内
周面をピストンヘッド部１の外周面１３に接合すること
によって、ピストンヘッド部ｌに断熱材３、断熱ガスケ
ット７、薄板部材５及び筒部材６を固定してビストンヘ
ッドを構成することができる。この場合に、薄板部材５
と筒部材６との間には、隙間２０を形成して両者が直接
的な接触をするのを防止する。By the way, the installation of these members is a process, for example,
The heat insulating material 3, thin plate member 5, and heat insulating gasket 7 are stacked one after another on the top surface of the piston head l, then the flange portion 12 of the cylindrical member 6 is placed on the heat insulating gasket 7, and the thin plate member 5 and the heat insulating material 3 are placed inside the cylindrical member 6. The heat insulating material 3, the heat insulating gasket 7, the thin plate member 5 and the cylinder member 6 are fixed to the piston head l by joining the inner circumferential surface of the cylinder member 6 to the outer circumferential surface 13 of the piston head part 1 while housed in the piston head l. The piston head can be configured by In this case, the thin plate member 5
A gap 20 is formed between the cylindrical member 6 and the cylindrical member 6 to prevent them from coming into direct contact.
それ故に、′１ｊｉｖｉ、部材５と筒部材６との間には
断熱ガスケット７が介在するのみであり、薄板部材５か
ら筒部材６への熱伝導を遮断状態に構成する。Therefore, only the heat insulating gasket 7 is interposed between the member 5 and the cylindrical member 6, and the heat conduction from the thin plate member 5 to the cylindrical member 6 is blocked.
従って、燃焼ガスに晒される薄板部材５の熱は、筒部材
６に熱伝導されず、シリンダライナ下部へ流れる熱流は
、筒部材６で受熱した熱量のみとなり、熱伝導を極めて
小さく抑えることができ、ビストンスカート部２の温度
上昇を抑えることができる。また、ピストンヘッド部ｌ
は、窒化珪素等のセラミック材で形成されてもよいが、
窒化珪素等のセラミック材と熱膨張係数がほぼ等しい炭
化珪素、金属等の材料でもよい、筒部材６とピストンへ
ノド部１との接合については、同一材料であれば、例え
ば、化学蒸着（ＣＶＤ）で達成できるが、異種材料であ
れば、その材料に適合した接合法により接合し、例えば
、金属−セラミック材では、該結合部をメタライズ接合
、或いはメタルフロー等によって強固に結合することが
できる。Therefore, the heat of the thin plate member 5 exposed to the combustion gas is not thermally conducted to the cylinder member 6, and the heat flow flowing to the lower part of the cylinder liner is only the amount of heat received by the cylinder member 6, making it possible to suppress heat conduction to an extremely low level. , the temperature rise of the piston skirt portion 2 can be suppressed. In addition, the piston head l
may be formed of a ceramic material such as silicon nitride,
The cylindrical member 6 and the throat portion 1 may be joined to the piston using a material such as silicon carbide or metal, which has a coefficient of thermal expansion approximately equal to that of a ceramic material such as silicon nitride, using chemical vapor deposition (CVD), for example. ), but in the case of dissimilar materials, they can be joined by a joining method suitable for the materials. For example, in the case of metal-ceramic materials, the joint can be firmly joined by metallization joining, metal flow, etc. .
第３図は、この発明による断熱エンジンの構造の別の実
施例を示しており、第１図の符号Ａの部分の別の構造を
示す拡大断面図である。燃焼室１５側に面する薄板部材
５とピストンヘッド部１に接合された筒部材６のフラン
ジ部１２との間に介在した断熱ガスケット８は、チタン
酸カリウムウィスカーとアルミナファイバーとの混合材
で製作したもの、これらの断熱材ペーパを積層して構成
したもの、或いはジルコニアファイバー等を用いたもの
等である。FIG. 3 shows another embodiment of the structure of the adiabatic engine according to the present invention, and is an enlarged sectional view showing another structure of the portion A in FIG. The heat insulating gasket 8 interposed between the thin plate member 5 facing the combustion chamber 15 side and the flange portion 12 of the cylindrical member 6 joined to the piston head portion 1 is made of a mixed material of potassium titanate whiskers and alumina fibers. These include those constructed by laminating these heat insulating papers, and those using zirconia fibers.
筒部材６について、上記では窒化珪素等のセラミック材
で製作されたものについて説明したが、例えば、この筒
部材６は、セラミック材料と線膨張係数、言い換えれば
、熱膨張係数かはソ等しい金属材料、例えば、ニンケル
クロム合金等の耐熱合金で形成することもできる。この
場合には、筒部材６の下部内周面にピストンヘッド部ｌ
の雄ねじに螺合する雌ねじを形成し、筒部材６をピスト
ンヘッド部１に螺入すると共に螺合部即ち結合部１３を
レーザビーム溶接、メタルフロー等によって結合し、該
結合部１３を１めで強固に結合することができる。更に
、断熱材３及び断熱ガスケット７．８については、チタ
ン酸カリウムウィスカーとアルミナファイバーとの混合
材で製作したものに限らず、例えば、チタン酸カリウム
ウィスカー、ジルコニアファイバー、ポロシティの大き
い耐熱材等で製作することができる。また、この断熱材
３は、断熱機能を果たすと共に、爆発時に薄板部材５に
作用する圧力を受は止める構造材としても機能する。こ
の断熱ピストンの構造については、爆発による圧縮力を
、チタン酸カリウムウィスカー、ポロシティの大きい耐
熱材等の断熱材３によって均等に受ける必要があり、そ
のため、ピストンヘッド部ｌの燃焼室１５側の面１８及
び薄板部材５は、平らな形状即ちフラットな形状に構成
されている。The cylindrical member 6 has been described above as being made of a ceramic material such as silicon nitride, but for example, the cylindrical member 6 may be made of a metal material whose linear expansion coefficient, in other words, thermal expansion coefficient, is the same as that of the ceramic material. For example, it can also be formed of a heat-resistant alloy such as a nickel chromium alloy. In this case, the piston head l is attached to the lower inner circumferential surface of the cylindrical member 6.
The cylindrical member 6 is screwed into the piston head 1, and the threaded part, that is, the joint part 13, is joined by laser beam welding, metal flow, etc., and the joint part 13 is connected in the first place. Can be strongly bonded. Furthermore, the heat insulating material 3 and the heat insulating gasket 7.8 are not limited to those made of a mixed material of potassium titanate whiskers and alumina fibers, but may also be made of, for example, potassium titanate whiskers, zirconia fibers, heat-resistant materials with large porosity, etc. It can be manufactured. Further, the heat insulating material 3 not only performs a heat insulating function but also functions as a structural member that blocks pressure acting on the thin plate member 5 at the time of an explosion. Regarding the structure of this heat-insulating piston, it is necessary to receive the compressive force caused by the explosion evenly by the heat-insulating material 3 such as potassium titanate whiskers and a heat-resistant material with large porosity. 18 and the thin plate member 5 are configured in a flat shape.
この発明による断熱ピストンの構造は、以上のように構
成されているので、次のような特有の効果を奏する。即
ち、この断熱ピストンの構造は、外周部にセラミック製
筒部材を接合したピストンヘッド部を断熱層を介してビ
ストンスカート部に固定し、前記筒部材に形成した押圧
部分で断熱ガスケットを介してセラミック製薄板部材の
周囲部分を押圧して前記ピストンヘッド部の上面に断熱
材を介して前記薄板部材を固定したので、燃焼室に晒さ
れる面となる前記薄板部材で受熱した熱は前記断熱ガス
ケットによって断熱され、外周部に配置された前記筒部
材には熱伝導されることがなく、しかも前記薄板部材と
前記ピストンヘッド部との間には前記断熱材によって同
様に断熱されているので、前記ビストンスカート部への
熱伝導が抑えられ、それ故に、燃焼ガスに晒される前記
薄板部材で受熱した熱量が前記ビストンスカート部に流
れることを防止でき、シリンダライナ下部の冷却が不要
になる。従って、この断熱ピストンは、例えば、シリン
ダライナの外周部のシリンダボディから水ジャケットを
排除した構造のものに適用して橿めて好ましいものであ
る。また、燃焼ガスに晒されて高温になるピストンヘッ
ドの表面部に位置する前記薄板部材の厚さを薄く構成で
き、その熱容量を可及的に小さく構成することができ、
吸入効率及びサイクル効率を向上させる。即ち、前記薄
板部材の厚さを薄く構成する程、ガス温度への追従性が
よくなり、そして、燃焼室内の高温時と低温時との壁温
振幅は厚さが厚い場合に比較して大きくなり、結果的に
燃焼ガスと前記薄板部材との温度差が小さくなり、熱伝
達量が減少するため、吸入空気の受熱を減少させる。し
かも、燃焼室側の高温になる前記ピストンヘッド部につ
いて前記薄板部材が直接晒される状態に構成されており
、断熱性、耐熱性、耐変形性、耐腐食性等を向上させる
ことができ、熱ショックを受けても強度上の問題が生じ
ることがなく、安定した取付状態を得ることができ、更
に爆発時に前記薄板部材に作用する圧力を、前記断熱材
が介在され、前記薄板部材及び前記ピストンヘッド部の
面が平らに形成されるので、均等に好ましい状態で受は
止めることができる。Since the structure of the heat insulating piston according to the present invention is configured as described above, it has the following unique effects. That is, the structure of this heat-insulating piston is such that a piston head part with a ceramic cylinder member joined to the outer periphery is fixed to the piston skirt part through a heat-insulating layer, and a ceramic cylinder is connected to the piston head part through a heat-insulating gasket at the pressing part formed on the cylinder member. Since the peripheral portion of the thin plate member is pressed and the thin plate member is fixed to the upper surface of the piston head via the heat insulating material, the heat received by the thin plate member, which is the surface exposed to the combustion chamber, is transferred by the heat insulating gasket. Heat is insulated and there is no heat conduction to the cylindrical member disposed on the outer periphery, and since the thin plate member and the piston head are similarly insulated by the heat insulating material, the piston Heat conduction to the skirt portion is suppressed, and therefore, the amount of heat received by the thin plate member exposed to combustion gas can be prevented from flowing to the piston skirt portion, making it unnecessary to cool the lower part of the cylinder liner. Therefore, this heat-insulating piston is particularly preferable when applied to, for example, a structure in which the water jacket is excluded from the cylinder body at the outer peripheral portion of the cylinder liner. Further, the thickness of the thin plate member located on the surface of the piston head that is exposed to combustion gas and becomes high temperature can be made thin, and its heat capacity can be made as small as possible.
Improves suction efficiency and cycle efficiency. In other words, the thinner the thin plate member is, the better the ability to follow the gas temperature, and the wall temperature amplitude between high and low temperatures in the combustion chamber is larger than when the thin plate member is thicker. As a result, the temperature difference between the combustion gas and the thin plate member becomes smaller, and the amount of heat transfer is reduced, so that the heat received by the intake air is reduced. Furthermore, the thin plate member is configured to be directly exposed to the piston head, which is exposed to high temperatures on the combustion chamber side, so that it is possible to improve heat insulation, heat resistance, deformation resistance, corrosion resistance, etc. Even if subjected to shock, no strength problems will occur, and a stable mounting state can be obtained.Furthermore, the pressure acting on the thin plate member during an explosion can be absorbed by the heat insulating material and the thin plate member and the piston. Since the surface of the head portion is formed flat, the receiver can be stopped evenly and in a favorable condition.
また、１１；ｉ記筒部材の内面と前記薄板部材の外面と
の間には、隙間が形成されているので、前記薄板部材か
ら前記筒部材への熱伝導は確実に遮断される。Furthermore, since a gap is formed between the inner surface of the cylindrical member 11; and the outer surface of the thin plate member, heat conduction from the thin plate member to the cylindrical member is reliably blocked.
第１図はこの発明による断熱ピストンの構造の一実施例
を示す断面図、第２図は第１図の符号Ａの部分の一例を
示す拡大断面図、第３図は第１図の符号Ａの部分の別の
例を示す拡大断面図、及び第４図は従来の断熱ピストン
の一例を示す断面図である。
■−−−−・ピストンヘッド部、２−−−ビストンスカ
ート部、３−御所熱材、５−一−−薄板部材、６−−−
−−−筒部材、７．８ ・−断熱ガスケット、１２−−
−−−フランジ部（押圧部分） 、１５−−−一燃焼室
、１８−ピストンへノド部の上面、２〇 −隙間。
出願人 いすソ自動車株式会社
代理人 弁理士 尾 仲 −宗
第 １ 図
第 ２ 図 第 ３ 間第
４図FIG. 1 is a cross-sectional view showing an example of the structure of a heat insulating piston according to the present invention, FIG. 2 is an enlarged cross-sectional view showing an example of the part marked A in FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view showing another example of the portion of FIG. ■--- Piston head part, 2---Viston skirt part, 3-Gosho heating material, 5-1---Thin plate member, 6---
---Cylinder member, 7.8 - Insulating gasket, 12--
---Flange part (pressing part), 15-- one combustion chamber, 18- upper surface of throat part to piston, 20- gap. Applicant Isuso Jidosha Co., Ltd. Agent Patent Attorney So Onaka Figure 1 Figure 2 Figure 3 Figure 4
Claims (2)
ヘッド部を断熱層を介してビストンスカート部に固定し
、前記筒部材に形成した押圧部分で断熱ガスケットを介
してセラミック製薄板部材の周囲部分を押圧して前記ピ
ストンヘッド部の上面に断熱材を介して前記薄板部材を
固定したことを特徴とする断熱ピストンの構造。(1) A piston head part with a ceramic cylindrical member joined to the outer periphery is fixed to the piston skirt part via a heat insulating layer, and a pressing part formed on the cylindrical member is connected to the peripheral part of the ceramic thin plate member via a heat insulating gasket. A structure of a heat insulating piston, characterized in that the thin plate member is fixed to the upper surface of the piston head via a heat insulating material by pressing.
は隙間が形成されていることを特徴とする請求項１に記
載の断熱ピストンの構造。(2) The structure of the heat insulating piston according to claim 1, wherein a gap is formed between the inner surface of the cylindrical member and the surface of the thin plate member.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14835688A JP2560422B2 (en) | 1988-06-17 | 1988-06-17 | Structure of adiabatic piston |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14835688A JP2560422B2 (en) | 1988-06-17 | 1988-06-17 | Structure of adiabatic piston |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01318750A true JPH01318750A (en) | 1989-12-25 |
| JP2560422B2 JP2560422B2 (en) | 1996-12-04 |
Family
ID=15450924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14835688A Expired - Lifetime JP2560422B2 (en) | 1988-06-17 | 1988-06-17 | Structure of adiabatic piston |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2560422B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100372165B1 (en) * | 2000-07-07 | 2003-02-14 | 최진희 | Ceramic engine |
| WO2015029985A1 (en) | 2013-08-26 | 2015-03-05 | 日本碍子株式会社 | Internal combustion engine |
| CN107630764A (en) * | 2017-08-10 | 2018-01-26 | 中国北方发动机研究所(天津) | A kind of NEW TYPE OF COMPOSITE heat insulation structural piston |
-
1988
- 1988-06-17 JP JP14835688A patent/JP2560422B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100372165B1 (en) * | 2000-07-07 | 2003-02-14 | 최진희 | Ceramic engine |
| WO2015029985A1 (en) | 2013-08-26 | 2015-03-05 | 日本碍子株式会社 | Internal combustion engine |
| US9951740B2 (en) | 2013-08-26 | 2018-04-24 | Ngk Insulators, Ltd. | Internal combustion engine |
| CN107630764A (en) * | 2017-08-10 | 2018-01-26 | 中国北方发动机研究所(天津) | A kind of NEW TYPE OF COMPOSITE heat insulation structural piston |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2560422B2 (en) | 1996-12-04 |
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