JPH0428882B2 - - Google Patents
Info
- Publication number
- JPH0428882B2 JPH0428882B2 JP61046497A JP4649786A JPH0428882B2 JP H0428882 B2 JPH0428882 B2 JP H0428882B2 JP 61046497 A JP61046497 A JP 61046497A JP 4649786 A JP4649786 A JP 4649786A JP H0428882 B2 JPH0428882 B2 JP H0428882B2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- shroud
- exhaust
- exhaust valve
- intake
- 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 - Lifetime
Links
- 239000000919 ceramic Substances 0.000 claims description 6
- 238000002485 combustion reaction Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 description 3
- 230000033001 locomotion Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
- Valve-Gear Or Valve Arrangements (AREA)
Description
【発明の詳細な説明】
「産業上の利用分野」
本発明は、内燃機関の排気弁に好適に利用され
得る。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention can be suitably used for exhaust valves of internal combustion engines.
「従来の技術」
従来、内燃機関の燃焼室に通ずる吸排気弁にお
いては、第３図に示すようなきのこ形状の弁を用
いてその開閉を弁体の上下運動によつて行うこと
により、吸気ガス及び排気ガスの出入を制御して
いた。ところで内燃機関の吸排気弁は高温高圧ガ
スにさらされて長時間の苛酷な運動に耐えなけれ
ばならないため、材質、形状などの選定にはきび
しい条件が要求される。近年その吸排気効率を向
上するために吸排気弁の軽量化を目的として材質
をセラミツクスとすることが行われている。ま
た、吸気にうずを発生させるために第４図に示す
ように吸気弁２１にシユラウド２２を付けること
が知られている。``Prior Art'' Conventionally, intake and exhaust valves communicating with the combustion chamber of internal combustion engines use mushroom-shaped valves as shown in Fig. 3, which are opened and closed by the vertical movement of the valve body. It controlled the inflow and outflow of gas and exhaust gas. Incidentally, since the intake and exhaust valves of internal combustion engines must withstand long-term harsh motions while being exposed to high-temperature, high-pressure gas, strict conditions are required when selecting materials, shapes, etc. In recent years, in order to improve the intake and exhaust efficiency, ceramics have been used as material for intake and exhaust valves in order to reduce their weight. It is also known to attach a shroud 22 to the intake valve 21, as shown in FIG. 4, in order to generate eddies in the intake air.
「発明が解決しようとする問題点」
しかしながら、材質をセラミツクスとすること
による軽量化において、従来のように単なるきの
こ型弁では強度的な要請から弁傘部の肉厚を厚く
しなければならず、かえつて重量が増すという問
題や、流れの抵抗が大きくなつて排気効率が低下
するという問題があつた。かといつて排気弁に第
４図に示したような吸気弁２１と同様のシユラウ
ドを付けると、シユラウドが排気ポート内壁に衝
突するのを避けるため、排気弁を回転させること
ができず、上下方向以外は固定されており、シリ
ンダヘツドのシートとの接触面が常に同じ位置と
なり、シートや排気弁の偏摩耗が起こるという問
題がある。``Problems to be solved by the invention'' However, in order to reduce the weight by using ceramics as the material, in the conventional mushroom-shaped valve, the thickness of the valve head must be increased due to strength requirements. However, there were problems in that the weight increased, and that the flow resistance increased and the exhaust efficiency decreased. However, if a shroud similar to the intake valve 21 shown in Fig. 4 is attached to the exhaust valve, the exhaust valve cannot be rotated in order to avoid the shroud colliding with the inner wall of the exhaust port, and the shroud cannot be rotated in the vertical direction. Since the other parts are fixed, the contact surface of the cylinder head with the seat is always at the same position, which causes uneven wear of the seat and exhaust valve.
「問題点を解決するための手段」
本発明は上記の問題点を解決するためになされ
たもので、その手段は、軸部及び弁傘部がセラミ
ツクス製である内燃機関の排気弁において、弁傘
部背面に放射状のシユラウドを一体的に設け、軸
部からシユラウドの始点までを研摩加工したとこ
ろにある。"Means for Solving the Problems" The present invention has been made in order to solve the above problems, and the present invention provides an exhaust valve for an internal combustion engine whose shaft portion and valve head portion are made of ceramics. A radial shroud is integrally provided on the back of the umbrella, and the area from the shaft to the starting point of the shroud is polished.
「作用」
本発明の作用を第１図及び第２図に基づいて説
明する。第１図及び第２図はそれぞれ本発明の一
実施例に係る排気弁の正面図及び平面図である。
図面において排気弁１１の弁傘部１３の肉厚は従
来の金属製排気弁の弁傘部の肉厚よりも薄く形成
してあり、その肉厚の減少を補うために放射状の
シユラウド１２，１２……１２が設けられてい
る。これによつて排気抵抗を小さくでき、しかも
軽量化を図ることができ高速回転にも適してい
る。また、肉厚の減少分をシユラウドによつて補
つているため強度的に低下することもない。"Operation" The operation of the present invention will be explained based on FIGS. 1 and 2. 1 and 2 are a front view and a plan view, respectively, of an exhaust valve according to an embodiment of the present invention.
In the drawing, the wall thickness of the valve head portion 13 of the exhaust valve 11 is formed to be thinner than the wall thickness of the valve head portion of a conventional metal exhaust valve, and in order to compensate for the decrease in wall thickness, radial shrouds 12, 12 are formed. ...12 are provided. This makes it possible to reduce exhaust resistance, reduce weight, and be suitable for high-speed rotation. Furthermore, since the shroud compensates for the decrease in wall thickness, there is no decrease in strength.
第５図及び第６図はそれぞれ本発明の他の実施
例に係る排気弁の斜視図及び平面図である。図面
において排気弁３１には弁傘部３３の背面に放射
状でかつわん曲したシユラウド３２，３２……３
２が設けられている。この場合、軸線を通るいか
なる軸方向断面においても二以上のシユラウドの
断面が現われるようにシユラウドを設けるのが望
ましい。すなわち、第８図Ａにおいて軸線を通る
いかなる軸方向断面（例えばイ−イ′断面）には
必ず二以上のシユラウドの断面が現われるのに対
し、第８図Ｂのような形状であれば例えば軸線を
通る軸方向ロ−ロ′断面にはシユラウドの断面が
全く現われないが、本願発明では前者が望ましい
とするのである。その理由は前者の方がシユラウ
ド間の面積が小さくなり、強度が向上することに
よる。 5 and 6 are a perspective view and a plan view, respectively, of an exhaust valve according to another embodiment of the present invention. In the drawing, the exhaust valve 31 has radial and curved shrouds 32, 32...3 on the back of the valve head part 33.
2 is provided. In this case, it is desirable to provide the shroud in such a way that at any axial cross section passing through the axis, two or more shroud cross sections appear. That is, in any axial cross section (e.g. E-A' cross section) passing through the axis in FIG. 8A, two or more cross sections of the shroud always appear, whereas if the shape is as shown in FIG. 8B, e.g. Although the cross section of the shroud does not appear at all in the axial roll-ro' cross section passing through the shaft, the former is desirable in the present invention. The reason for this is that in the former case, the area between the shrouds is smaller and the strength is improved.
排気弁においては弁傘部１３の裏側１３ａと軸
部１４との境界付近１５が熱的に最も厳しい位置
となる（以下、第９図参照）。ところが、軸部１
４のステムガイド（図示省略）と摺動する部位は
精度が必要なため研摩を行うが、他方弁傘部１３
の背面１３ａは研摩の必要がない。しかし、研摩
部と未研摩部の段差が上記境界付近１５に相当す
ると応力集中の原因となる。そこで、軸部１４全
体のみならず、背面１３ａの境界付近１５（図中
斜線部）をも研摩し、かつこの部分をアール形状
とすることにより応力集中を避けるのが望まし
い。この場合のアール形状は、R5以上とするの
が効果的である。 In the exhaust valve, the vicinity 15 of the boundary between the back side 13a of the valve head portion 13 and the shaft portion 14 is the most thermally severe position (see FIG. 9 below). However, the shaft part 1
The parts that slide with the stem guide (not shown) in No. 4 are polished because precision is required.
The back surface 13a does not require polishing. However, if the level difference between the polished part and the unpolished part corresponds to the boundary area 15, it will cause stress concentration. Therefore, it is desirable to avoid stress concentration by polishing not only the entire shaft portion 14 but also the boundary area 15 (shaded area in the figure) of the back surface 13a and making this portion rounded. In this case, it is effective to set the radius shape to R5 or more.
「実施例」
第５図において、シユラウドを５枚設けた窒化
ケイ素95重量％よりなる排気弁３１を、セラミツ
クス粉末を射出成形又はラバープレス後高温焼成
することによつて製造したところ、その重量は従
来の金属製排気弁の重量の60％であつた。"Example" In FIG. 5, an exhaust valve 31 made of 95% by weight silicon nitride with five shrouds was manufactured by injection molding or rubber pressing ceramic powder and then firing at high temperature. It was 60% of the weight of conventional metal exhaust valves.
「効果」
軽量化を図ることができるとともに、強度が向
上する。燃料効率が良くなる。``Effect'' It is possible to reduce weight and improve strength. Improves fuel efficiency.
「参考例」
なお、排気弁と同様に吸気弁も第５図のように
シユラウドを放射状で、かつわん曲した形状にす
ると、シユラウド３２，３２……３２の表側３２
ａ，３２ａ……３２ａに当たる吸気流については
うずが発生するが、裏側３２ｂ，３２ｂ……３２
ｂに当たる吸気流に対してはシユラウド３２，３
２……３２が抵抗となることから、シユラウド３
２，３２……３２の表側３２ａ，３２ａ……３２
ａに大部分の吸気流が当たるように第７図に示す
ように吸気ポート３４の片側３４ａを外側にふく
らませると良好なうずを発生させることができ
る。"Reference example" If the shroud of the intake valve is made into a radial and curved shape as shown in Fig. 5, the front side 32 of the shrouds 32, 32...32
A, 32a...32a causes eddies, but the back side 32b, 32b...32
Shroud 32,3 for the intake air flow corresponding to
Since 2...32 is the resistance, shroud 3
2, 32...32 front side 32a, 32a...32
If one side 34a of the intake port 34 is bulged outward as shown in FIG. 7 so that most of the intake airflow hits point a, a good swirl can be generated.
第１図及び第２図は、それぞれ本発明の一実施
例に係る排気弁の正面図及び平面図、第３図及び
第４図はそれぞれ従来の吸排気弁の正面図及び従
来の他の吸気弁の斜視図、第５図及び第６図はそ
れぞれ本発明の他の実施例に係る排気弁の斜視図
及び平面図、第７図は本発明排気弁と同一形状の
吸気弁を吸気ポートに取り付けたところを弁軸方
向から眺めた平面図、第８図Ａ及びＢは本発明吸
気弁を弁軸方向から眺めた平面図、第９図は本発
明の排気弁の要部正面図である。
１１……排気弁、２１，３１……吸気弁、１
２，２２，３２……シユラウド、１３，２３，３
３……弁傘部。
1 and 2 are respectively a front view and a plan view of an exhaust valve according to an embodiment of the present invention, and FIGS. 3 and 4 are respectively a front view of a conventional intake and exhaust valve and another conventional intake valve. 5 and 6 are respectively a perspective view and a plan view of an exhaust valve according to another embodiment of the present invention, and FIG. 7 shows an intake valve having the same shape as the exhaust valve of the present invention at an intake port. FIG. 8A and B are plan views of the intake valve of the present invention viewed from the valve shaft direction, and FIG. 9 is a front view of the main parts of the exhaust valve of the present invention. . 11... Exhaust valve, 21, 31... Intake valve, 1
2, 22, 32... Shroud, 13, 23, 3
3... Valve umbrella part.
Claims (1)
弁において、弁傘部背面に放射状のシユラウドが
一体的に設けられており、軸部からシユラウドの
始点までを研摩加工してなることを特徴とする内
燃機関のセラミツクス製排気弁。1. An exhaust valve whose shaft portion and valve head portion are made of ceramics, characterized in that a radial shroud is integrally provided on the back of the valve head portion, and the portion from the shaft portion to the starting point of the shroud is polished. Ceramic exhaust valve for internal combustion engines.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4649786A JPS62203910A (en) | 1986-03-04 | 1986-03-04 | Ceramic intake and exhaust valve for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4649786A JPS62203910A (en) | 1986-03-04 | 1986-03-04 | Ceramic intake and exhaust valve for internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62203910A JPS62203910A (en) | 1987-09-08 |
| JPH0428882B2 true JPH0428882B2 (en) | 1992-05-15 |
Family
ID=12748868
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4649786A Granted JPS62203910A (en) | 1986-03-04 | 1986-03-04 | Ceramic intake and exhaust valve for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62203910A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02115924U (en) * | 1989-03-03 | 1990-09-17 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5569721A (en) * | 1978-11-17 | 1980-05-26 | Toyota Motor Corp | Suction valve type internal combustion engine |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62116104U (en) * | 1986-01-16 | 1987-07-23 |
-
1986
- 1986-03-04 JP JP4649786A patent/JPS62203910A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5569721A (en) * | 1978-11-17 | 1980-05-26 | Toyota Motor Corp | Suction valve type internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62203910A (en) | 1987-09-08 |
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