JPH0248813B2 - - Google Patents
Info
- Publication number
- JPH0248813B2 JPH0248813B2 JP58104201A JP10420183A JPH0248813B2 JP H0248813 B2 JPH0248813 B2 JP H0248813B2 JP 58104201 A JP58104201 A JP 58104201A JP 10420183 A JP10420183 A JP 10420183A JP H0248813 B2 JPH0248813 B2 JP H0248813B2
- Authority
- JP
- Japan
- Prior art keywords
- ceramic
- heater
- tip
- glow plug
- outer periphery
- 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 23
- 229910052751 metal Inorganic materials 0.000 claims description 20
- 239000002184 metal Substances 0.000 claims description 20
- 238000010438 heat treatment Methods 0.000 claims description 14
- 238000002485 combustion reaction Methods 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 229910001080 W alloy Inorganic materials 0.000 claims description 2
- 229910052702 rhenium Inorganic materials 0.000 claims description 2
- 238000009423 ventilation Methods 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims 1
- 239000011733 molybdenum Substances 0.000 claims 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims 1
- 239000010937 tungsten Substances 0.000 claims 1
- 239000000446 fuel Substances 0.000 description 10
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 229910017060 Fe Cr Inorganic materials 0.000 description 1
- 229910002544 Fe-Cr Inorganic materials 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000000630 rising effect Effects 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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23Q—IGNITION; EXTINGUISHING-DEVICES
- F23Q7/00—Incandescent ignition; Igniters using electrically-produced heat, e.g. lighters for cigarettes; Electrically-heated glowing plugs
- F23Q7/001—Glowing plugs for internal-combustion engines
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
Description
【発明の詳細な説明】
本発明は、主としてデイーゼルエンジンの始動
時における着火補助のために用いるグロープラグ
に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glow plug used primarily to assist in ignition when starting a diesel engine.
デイーゼルエンジンの始動補助装置としては、
従来先端を閉塞した耐熱金属シース内に、マグネ
シア、アルミナ等の絶縁粉体を充填し、この中に
Fe―Cr、Ni等の発熱線を埋設したシーズヒータ
ー構造をもつメタル型グロープラグを副燃焼室内
に装着し、該プラグに通電して赤熱し、室内に噴
射される燃料の一部を燃焼させてエンジンの始動
を容易にする方法が知られている。 As a starting aid for diesel engines,
Conventionally, an insulating powder such as magnesia or alumina is filled inside a heat-resistant metal sheath whose tip is closed.
A metal glow plug with a sheathed heater structure in which a heating wire of Fe-Cr, Ni, etc. is buried is installed in the auxiliary combustion chamber, and the plug is energized to become red hot and burn a part of the fuel injected into the chamber. There is a known method for making it easier to start the engine.
然し乍らグロープラグは、エンジンの始動等に
は極めて有効である反面、始動後における燃焼安
定化のためのアフターグローとしての長時間運転
域においては、燃焼室内におけるその存在が、燃
焼性に与える影響の問題があつた。 However, while glow plugs are extremely effective for starting the engine, their presence in the combustion chamber has a negative impact on combustibility during long-term operation as an afterglow to stabilize combustion after startup. There was a problem.
即ち特に第１図に示す如き渦流室等の場合は、
始動後の圧縮行程において渦流室１内に連絡孔２
より流入する空気によつて室内に渦流を生ぜし
め、これに燃料噴射ノズル３より噴射され、グロ
ープラグにより予熱された燃料によつて混合気を
完全燃焼させようとするものであるから、渦流室
１内にグロープラグのヒーター部４が突出してい
ると始動後はこれが障害物となつてスムーズな渦
流形成を阻害することとなり、エンジン出力の低
下、燃費の悪化、有害な排気ガスの増大等エンジ
ン性能に悪影響を及ぼすという問題点があつた。
従つてグロープラグのヒーター部は可及的に細径
として、かつ急速昇温に適したものとする必要が
あるが、前記せるメタル型グロープラグに於て
は、ヒーター部の径を細くすると金属シースをも
つため噴射燃料及び渦流気による冷却作用により
昇温効率を低下させるほか、発熱線の融点が低い
ために加熱温度も余り上げられないという欠点が
あり、このため近時はＷ、Moもしくはこれらの
合金の如き高耐熱金属線材からなる発熱線をセラ
ミツク焼結体中に埋設したセラミツクヒーターを
ヒーター部としたセラミツクグロープラグが用い
られている。 That is, especially in the case of a vortex chamber as shown in Fig. 1,
A communication hole 2 is formed in the swirl chamber 1 during the compression stroke after startup.
The purpose is to create a vortex in the room by the air flowing in, and to completely burn the air-fuel mixture with the fuel injected from the fuel injection nozzle 3 and preheated by the glow plug. If the heater part 4 of the glow plug protrudes inside the interior of the engine, it will become an obstacle after starting and prevent smooth formation of a vortex. There was a problem that it had a negative effect on performance.
Therefore, the diameter of the heater part of the glow plug needs to be as small as possible and suitable for rapid temperature rise. Since it has a sheath, the heating efficiency is reduced due to the cooling effect of the injected fuel and swirling air, and the heating temperature cannot be raised very much due to the low melting point of the heating wire.For this reason, recently, W, Mo or Ceramic glow plugs are used in which the heater section is a ceramic heater in which heating wires made of highly heat-resistant metal wires such as these alloys are embedded in a ceramic sintered body.
このセラミツクヒーターは、前記のメタル型グ
ロープラグと異なりヒーター部が金属シースで覆
われていないため昇温効率が良く、また発熱線に
高耐熱金属を用いているため急速昇温によつて溶
断するおそれも極めて少ない利点を持つものであ
るが、この場合に於ても高温となるヒーター部は
渦流室内に曝され噴射燃料及び渦流気により表面
が冷却されるため、熱衝撃によりセラミツク割れ
を生ずるという問題があつた。 Unlike the metal glow plugs mentioned above, this ceramic heater has good heating efficiency because the heater part is not covered with a metal sheath, and because the heating wire uses a highly heat-resistant metal, it will not melt due to rapid temperature rise. Although this method has the advantage of minimizing the risk of thermal shock, even in this case, the high temperature heater section is exposed to the vortex chamber and its surface is cooled by the injected fuel and vortex air, so it is said that the ceramic cracks may occur due to thermal shock. There was a problem.
本発明は、かかる実情に鑑みなされたものであ
つて、渦流室等燃焼室内の突出するセラミツクヒ
ーターを金属外筒で覆い噴射燃料及び渦流気の冷
気が直接触れないようにするとともに、先端部に
おける発熱線埋設部分の外周と、金属外筒内壁の
間にのみ間隙を設けて昇温特性を向上し、かつ燃
料への着火性を阻害することなく始動性に優れた
セラミツクグロープラグを提供しようとするもの
である。 The present invention has been developed in view of the above circumstances, and includes covering a ceramic heater protruding inside a combustion chamber such as a vortex chamber with a metal outer cylinder to prevent the injected fuel and cold air from vortex air from coming into direct contact with the ceramic heater. We have attempted to provide a ceramic glow plug that improves temperature rise characteristics by providing a gap only between the outer periphery of the buried part of the heating wire and the inner wall of the metal outer cylinder, and has excellent starting performance without impairing the ignition of the fuel. It is something to do.
以下本発明につき付図を用いて詳細に説明す
る。 Hereinafter, the present invention will be explained in detail using the accompanying drawings.
第２図は、本発明セラミツクグロープラグの実
施例についての縦断面図を示したものであり、図
において１１はセラミツクヒーターで、Ｗ、Mo
もしくはＷとRe、Co、Mo、Zr等とのＷ合金を
線材として用い中央部分でＵ字状に折曲げられて
なる発熱線１２には、その両端にリード線１３―
１及び１３―2が溶接され、これを例えば窒化ケイ
素（Si3N4）を主成分としたセラミツク焼結体中
に埋設してなるもので、このセラミツクヒーター
１１は、金属外筒１４の内腔に嵌着されその先端
を該金属外筒１４の先端より僅かに（１〜２mm）
突出させて保持され、第３図イ及びロにその要部
を拡大して示す如く、先端部における発熱線１２
の埋設部で長さＬ（５〜10mm）に相当する部分に
外周には、金属外筒１４の内壁との間に間隙１５
を形成してなるものである。 FIG. 2 shows a longitudinal cross-sectional view of an embodiment of the ceramic glow plug of the present invention.
Alternatively, the heating wire 12 is made of a W alloy of W and Re, Co, Mo, Zr, etc., and is bent into a U-shape at the center, with lead wires 13 at both ends.
1 and 13-2 are welded and embedded in a ceramic sintered body mainly composed of, for example, silicon nitride (Si 3 N 4 ). It is fitted into the cavity and its tip is slightly (1 to 2 mm) smaller than the tip of the metal outer cylinder 14.
The heating wire 12 at the tip is held protruding and is shown in enlarged view in FIGS. 3A and 3B.
There is a gap 15 between the inner wall of the metal outer cylinder 14 and the outer periphery of the buried part corresponding to the length L (5 to 10 mm).
It is formed by forming.
なお前記金属外筒１４の先端外周には第３図ハ
に示す如く複数の円形又は長円形の通気孔１４―
１を設けてもよい。 As shown in FIG. 3C, a plurality of circular or oval ventilation holes 14 are provided on the outer periphery of the tip of the metal outer cylinder 14.
1 may be provided.
而して第２図に示すように発熱線１２の一端に
溶接されたリード線１３―1は金属外筒１４にろ
う接等により電気的に接続され、金属外筒１４は
取付金具１６の内腔に挿嵌されろう接されて電
極を構成し、一方発熱線１２の他端に溶接された
リード線１３―2は、セラミツクヒーター１１の
後端部側面でこれにろう接されているリード棒１
７に電気的に接続され、このリード棒１７が溶接
された中軸１８が絶縁体１９を取付金具１６との
間に介在させて丸ナツト２０で締付け固定され
電極となる構造をもつものである。 As shown in FIG. 2, the lead wire 13-1 welded to one end of the heating wire 12 is electrically connected to the metal outer cylinder 14 by brazing or the like, and the metal outer cylinder 14 is connected to the inside of the mounting bracket 16. The lead wire 13-2 is inserted into the cavity and soldered to form an electrode, while the lead wire 13-2 welded to the other end of the heating wire 12 is a lead rod that is soldered to the rear end side of the ceramic heater 11. 1
The center shaft 18, to which the lead rod 17 is welded, is tightened and fixed with a round nut 20 with an insulator 19 interposed between it and the mounting bracket 16, thereby forming an electrode.
このような構造をもつ本発明セラミツクグロー
プラグは、ヒーター部に、細径のセラミツクヒー
ターを用いているため、燃焼室内の渦流形成を阻
害することが少なく、室内突出部分はその大部分
が金属外筒で覆われており噴射燃料や渦流気が直
接触れないため高温のヒーター表面への冷却作用
が抑制されてセラミツク割れの発生を防止できる
ほか、先端部の発熱線埋設部分の外周には金属外
筒との間にのみ間隙が設けられ、必要により、さ
らに前記間隙形成部分の金属外筒先端外周に通気
孔を穿設することにより昇温特性を向上し、かつ
燃料への着火性能も低下しないので始動性に優れ
る利点をもつものであつて、昇温効果がすぐれ耐
久性の良い従来の欠点、問題点を解決した予熱装
置として提供できるものである。 The ceramic glow plug of the present invention having such a structure uses a small-diameter ceramic heater in the heater part, so it hardly interferes with the formation of vortices in the combustion chamber, and most of the protruding parts in the interior are made of metal. Since it is covered with a cylinder and the injected fuel and swirling air do not come into direct contact with it, the cooling effect on the high temperature heater surface is suppressed and the occurrence of ceramic cracking can be prevented. A gap is provided only between the metal outer cylinder and the cylinder, and if necessary, a vent hole is further provided on the outer periphery of the tip of the metal outer cylinder in the gap forming part, thereby improving the temperature rising characteristics and not reducing the performance of igniting the fuel. Therefore, it has the advantage of excellent startability, and can be provided as a preheating device that has an excellent temperature raising effect and good durability, and solves the conventional drawbacks and problems.
第１図は、グロープラグの渦流室への装着状態
を示す縦断面略図、第２図は本発明セラミツクグ
ロープラグの実施例を示す縦断面図、第３図イは
第２図におけるセラミツクヒーターの先端部構造
を示す要部拡大縦断面図、同図ロはその先端の端
面図で、第３図ハは、第２図におけるセラミツク
ヒーターの金属外筒先端部構造についての他の実
施例である。
１：渦流室、２：連絡孔、３：ノズル、４：グ
ロープラグ、１１：セラミツクヒーター、１２：
発熱線、１３―1，１３―2：リード線、１４：金
属外筒、１５：間隙、１６：取付金具、１７：リ
ード棒、１８：中軸、１９：絶縁体、２０：丸ナ
ツト。
FIG. 1 is a schematic vertical cross-sectional view showing how the glow plug is installed in the vortex chamber, FIG. 2 is a vertical cross-sectional view showing an embodiment of the ceramic glow plug of the present invention, and FIG. FIG. 3C is an enlarged vertical cross-sectional view of the main part showing the structure of the tip; FIG. 3B is an end view of the tip; FIG. . 1: Swirl chamber, 2: Communication hole, 3: Nozzle, 4: Glow plug, 11: Ceramic heater, 12:
Heat generating wire, 13-1 , 13-2 : Lead wire, 14: Metal outer cylinder, 15: Gap, 16: Mounting bracket, 17: Lead rod, 18: Center shaft, 19: Insulator, 20: Round nut.
Claims (1)
ター部を可及的に細径に形成してなるグロープラ
グにおいて、前記ヒーター部を、タングステン
（Ｗ）、モリブデン（Mo）あるいはＷとRe、Co、
Mo、Zr等とのＷ合金を線材とした発熱線をセラ
ミツク焼結体中に埋設したセラミツクヒーターが
その先端にわたつて金属外筒の延設部分で覆われ
保持されてなるものとし、該セラミツクヒーター
には、その先端部における発熱線埋設部分の外周
と金属外筒内壁との間にのみ間隙が設けられてい
ることを特徴とするセラミツクグロープラグ。 ２ セラミツクヒーターの先端部外周との間に間
隙を設けた前記金属外筒の先端部外周に、複数の
通気孔を配設したことを特徴とする特許請求の範
囲第１項記載のセラミツクグロープラグ。[Scope of Claims] 1. A glow plug in which a heater portion protruding into the auxiliary combustion chamber of a cylinder head is formed to have a diameter as small as possible, wherein the heater portion is made of tungsten (W), molybdenum (Mo), or W. and Re, Co.
A ceramic heater in which a heating wire made of a W alloy with Mo, Zr, etc. is embedded in a ceramic sintered body is covered and held over its tip by an extended part of a metal outer cylinder, and the ceramic heater is A ceramic glow plug characterized in that the heater has a gap only between the outer periphery of the heating wire buried portion at the tip thereof and the inner wall of the metal outer cylinder. 2. The ceramic glow plug according to claim 1, wherein a plurality of ventilation holes are provided on the outer periphery of the tip of the metal outer cylinder with a gap provided between the outer periphery of the tip of the ceramic heater and the outer periphery of the tip of the ceramic heater. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10420183A JPS59231323A (en) | 1983-06-13 | 1983-06-13 | Ceramic glow plug |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10420183A JPS59231323A (en) | 1983-06-13 | 1983-06-13 | Ceramic glow plug |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59231323A JPS59231323A (en) | 1984-12-26 |
| JPH0248813B2 true JPH0248813B2 (en) | 1990-10-26 |
Family
ID=14374354
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10420183A Granted JPS59231323A (en) | 1983-06-13 | 1983-06-13 | Ceramic glow plug |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59231323A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2683108B2 (en) * | 1989-07-03 | 1997-11-26 | 日本特殊陶業株式会社 | Seeds glow plug |
| JPH0724627Y2 (en) * | 1989-12-27 | 1995-06-05 | 三菱自動車工業株式会社 | Glow plug cover |
| JP4441136B2 (en) * | 2001-03-16 | 2010-03-31 | 日本特殊陶業株式会社 | Ceramic glow plug and its mounting structure to cylinder head |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5895122A (en) * | 1981-12-01 | 1983-06-06 | Ngk Spark Plug Co Ltd | Glow plug for high temperature |
| JPS5842557B2 (en) * | 1980-01-24 | 1983-09-20 | 株式会社東芝 | random access memory circuit |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57172273U (en) * | 1981-04-20 | 1982-10-29 | ||
| JPS6030607Y2 (en) * | 1981-09-07 | 1985-09-13 | いすゞ自動車株式会社 | Ceramic glow plug |
-
1983
- 1983-06-13 JP JP10420183A patent/JPS59231323A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5842557B2 (en) * | 1980-01-24 | 1983-09-20 | 株式会社東芝 | random access memory circuit |
| JPS5895122A (en) * | 1981-12-01 | 1983-06-06 | Ngk Spark Plug Co Ltd | Glow plug for high temperature |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59231323A (en) | 1984-12-26 |
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