JPH09280563A - Ceramic glow plug - Google Patents

Ceramic glow plug

Info

Publication number
JPH09280563A
JPH09280563A JP9444696A JP9444696A JPH09280563A JP H09280563 A JPH09280563 A JP H09280563A JP 9444696 A JP9444696 A JP 9444696A JP 9444696 A JP9444696 A JP 9444696A JP H09280563 A JPH09280563 A JP H09280563A
Authority
JP
Japan
Prior art keywords
heater
center shaft
housing
glow plug
central shaft
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
Application number
JP9444696A
Other languages
Japanese (ja)
Inventor
Masakazu Kurihara
正和 栗原
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Corp
Original Assignee
Denso Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Denso Corp filed Critical Denso Corp
Priority to JP9444696A priority Critical patent/JPH09280563A/en
Publication of JPH09280563A publication Critical patent/JPH09280563A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To enable connection of a heater and a central shaft on the same axis substantially without necessitating a process of correcting the coaxiality of the heater with the central shaft, by bringing one end part of the heater into contact with one end part of the central shaft and by soldering the two end parts directly in this state. SOLUTION: A heater 4 formed of insulative ceramic is fixed to one end part 2a of a housing 2 with a metal sleeve 3 interposed. The housing 2 and the metal sleeve 3, and the metal sleeve 3 and the heater 4, are soldered. A central shaft 7 is fixed to the other end part 2b of the housing 2 and a recessed part 73 is formed in one end part 71 of the central shaft 7. The recessed part 73 is constructed of a circular hole part (first part) 73a wherein one end part 41 of the heater 4 is disposed and of a conical hole part (second part) 73b which is recessed conically further from the circular hole part 73a. One end part 71 of the central shaft 7 and one end part 41 of the heater 4 are soldered with a soldering material 104 such as silver solder.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【発明の属する技術分野】本発明は、ディーゼルエンジ
ンの副室内を予熱するためのセラミックグロープラグに
関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic glow plug for preheating a sub chamber of a diesel engine.

【0002】[0002]

【従来の技術】図7(a)に示す従来技術のセラミック
グロープラグ1では、ヒータ4と中軸7とを接続金具1
1を介して接続していた。接続金具11は、図7(b)
に示すように、円筒部11aと、この円筒部11aから
軸方向に直線状に延びる直線部11bとからなり、円筒
部11aをヒータ4の一端部41に外挿した状態で接合
され、直線部11bが中軸7の一端部71外周面に接合
されている。
2. Description of the Related Art In a conventional ceramic glow plug 1 shown in FIG. 7A, a heater 4 and a center rod 7 are connected to each other by a metal fitting 1
I was connected through 1. The connection fitting 11 is shown in FIG.
As shown in FIG. 2, the cylindrical portion 11a and the linear portion 11b linearly extending in the axial direction from the cylindrical portion 11a are joined. 11b is joined to the outer peripheral surface of one end 71 of the center shaft 7.

【0003】[0003]

【発明が解決しようとする課題】ところが、上記従来技
術では、中軸7と接続金具11、および、ヒータ4と接
続金具11の2箇所を接合して中軸7とヒータ4とが接
続されるため、接合部分毎の位置ずれや、接続金具11
の寸法公差が合算されてしまい、ヒータ4と中軸7とを
略同軸上に接続できなくなってしまう。
However, in the above-mentioned conventional technique, the center rod 7 and the heater 4 are connected by joining the two positions of the center rod 7 and the connecting member 11 and the heater 4 and the connecting member 11 to each other. Displacement of each joint, connection fitting 11
Since the dimensional tolerances are added up, the heater 4 and the center shaft 7 cannot be connected substantially coaxially.

【0004】ここで、図2に示すように、セラミックグ
ロープラグ1をディーゼルエンジン100の複数のシリ
ンダヘッド101にネジ結合した後、電力供給用のコネ
クティングバー100cの複数の貫通孔100dを、複
数のセラミックグロープラグ1の中軸7に同時に挿嵌
し、ナット100eおよびスクリューグロメット100
fにより、コネクティングバー100cを中軸7に締め
つけ固定している。
Here, as shown in FIG. 2, after the ceramic glow plug 1 is screwed to a plurality of cylinder heads 101 of the diesel engine 100, a plurality of through holes 100d of a connecting bar 100c for power supply are formed into a plurality of through holes 100d. The ceramic glow plug 1 is inserted into the middle shaft 7 at the same time and fitted with the nut 100e and the screw grommet 100.
The connecting bar 100c is fastened and fixed to the center shaft 7 by f.

【0005】このため、中軸7とヒータ4とが略同軸上
に接続できていないと、コネクティングバー100cの
複数の貫通孔100dを中軸7に同時に挿嵌できなって
しまう。この場合、中軸7とヒータ4とを接続した後
に、ヒータ4と中軸7との同軸度を矯正する工程が必要
となり、生産性の悪いものであった。本発明は上記問題
に鑑みてなされたもので、ヒータと中軸との同軸度を矯
正する工程を必要とすることなく、ヒータと中軸とを略
同軸上に接続できるようにすることを目的とする。
For this reason, if the central shaft 7 and the heater 4 cannot be connected substantially coaxially, the plurality of through holes 100d of the connecting bar 100c cannot be inserted into the central shaft 7 at the same time. In this case, a step of correcting the coaxiality between the heater 4 and the central shaft 7 is required after connecting the central shaft 7 and the heater 4, resulting in poor productivity. The present invention has been made in view of the above problems, and an object of the present invention is to enable the heater and the center shaft to be connected substantially coaxially without requiring a step of correcting the coaxiality of the heater and the center shaft. .

【0006】[0006]

【課題を解決するための手段】上記目的を達成するため
に、請求項1ないし3に記載の発明では、ヒータ(4)
の一端部(41)と中軸(7)の一端部(71)とが当
接した状態で、両一端部(41)、(71)同志を直接
ろう接することを特徴としている。従って、ヒータ
(4)と中軸(7)とを直接ろう接しているので、接続
金具を介してヒータ(4)と中軸(7)とを接続する従
来技術に比べて、ヒータ(4)と中軸(7)との同軸度
を大幅に向上できる。このため、ヒータ(4)と中軸
(7)とを接続した後に同軸度を矯正する工程を必要と
せず、従来技術に比べて生産性をよくできる。
In order to achieve the above object, in the invention described in claims 1 to 3, the heater (4) is provided.
The one end portion (41) and the one end portion (71) of the center shaft (7) are in contact with each other, and both end portions (41) and (71) are directly brazed to each other. Therefore, since the heater (4) and the center shaft (7) are directly brazed to each other, the heater (4) and the center shaft (7) are connected with the heater (4) and the center shaft (7) via a connecting fitting, as compared with the prior art. The coaxiality with (7) can be greatly improved. Therefore, the step of correcting the coaxiality after connecting the heater (4) and the center shaft (7) is not required, and the productivity can be improved as compared with the conventional technique.

【0007】また、上記接続金具のような別部品が必要
ないので、セラミックグロープラグの構造が単純とな
り、コスト安となる。また、請求項2に記載の発明で
は、中軸(7)およびヒータ(4)のいずれか一方の一
端部(71)に形成した凹部(73)に、中軸(7)お
よびヒータ(4)のいずれか他方の一端部(41)を嵌
合した状態で、凹部(73)に上記他方の一端部(4
1)をろう接することを特徴としている。
Further, since a separate part such as the above-mentioned connecting fitting is not required, the structure of the ceramic glow plug is simple and the cost is low. Further, in the invention as set forth in claim 2, any one of the center shaft (7) and the heater (4) is provided in the recess (73) formed in one end portion (71) of one of the center shaft (7) and the heater (4). With the other end (41) fitted, the other end (4) is inserted into the recess (73).
It is characterized by brazing 1).

【0008】このため、上記他方の一端部(41)を凹
部(73)に嵌合することで、ヒータ(4)と中軸
(7)とが径方向についてある程度位置決めされる。よ
って、ヒータ(4)と中軸(7)との同軸度をさらに大
幅に向上できる。また、上記他方の一端部(41)を凹
部(73)に嵌合した状態なので、柱状部材の端面同志
を当接させたものに比べてろう接面積を大きくでき、ヒ
ータ(4)と中軸(7)との接合強度をより強くでき
る。
Therefore, by fitting the other end portion (41) into the recess portion (73), the heater (4) and the center shaft (7) are positioned to some extent in the radial direction. Therefore, the coaxiality between the heater (4) and the center shaft (7) can be further greatly improved. Further, since the other end portion (41) is fitted in the recess portion (73), the brazing area can be made larger than that in the case where the end faces of the columnar members are in contact with each other, and the heater (4) and the inner shaft ( The joint strength with 7) can be made stronger.

【0009】また、請求項3に記載の発明では、凹部
(73)は、上記他方の一端部(41)が配置される第
1部分(73a)と、この第1部分(73a)よりも断
面積が小さく、上記他方の一端部(41)の先端側に形
成される第2部分(73b)とから構成されている。こ
のため、凹部(73)が第1部分(73a)だけのもの
に比べて、上記他方の一端部(41)の先端側端面にろ
う材(104)が回りやすくなり、ヒータ(4)と中軸
(7)との接合強度をより一層強くできる。
Further, in the third aspect of the invention, the concave portion (73) is more severe than the first portion (73a) in which the other end portion (41) is arranged and the first portion (73a). The second area (73b) has a small area and is formed on the tip side of the other end (41). For this reason, the brazing material (104) is more likely to rotate around the tip end side end surface of the other end portion (41) as compared with the case where the concave portion (73) is only the first portion (73a), and the heater (4) and the center rod The joint strength with (7) can be further increased.

【0010】[0010]

【発明の実施の形態】本発明の実施形態を図に基づいて
説明する。 (第1の実施形態)図2に示すように、本実施形態のセ
ラミックグロープラグ1は、ディーゼルエンジン100
の複数のシリンダヘッド101にそれぞれ取り付けら
れ、副室を予熱するためのものである。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. (First Embodiment) As shown in FIG. 2, the ceramic glow plug 1 of the present embodiment is a diesel engine 100.
Is attached to each of the plurality of cylinder heads 101 to preheat the sub chamber.

【0011】以下、セラミックグロープラグ1の具体的
構造を図に基づいて説明する。図1(a)に示すよう
に、セラミックグロープラグ1は、略筒状で金属製のハ
ウジング2を備えており、このハウジング2の外周部に
は、上記ディーゼルエンジン100(図2参照)の雌ネ
ジ部100a(図2参照)と螺合する雄ネジ部21が形
成されている。
The specific structure of the ceramic glow plug 1 will be described below with reference to the drawings. As shown in FIG. 1 (a), a ceramic glow plug 1 is provided with a substantially tubular metal housing 2, and the housing 2 has an outer peripheral portion on which a female of the diesel engine 100 (see FIG. 2) is provided. A male screw portion 21 that is screwed with the screw portion 100a (see FIG. 2) is formed.

【0012】ハウジング2の一端部2aには、金属スリ
ーブ3を介して絶縁性セラミックからなるヒータ4が固
定されている。ハウジング2と金属スリーブ3、およ
び、金属スリーブ3とヒータ4とは、ろう接されてい
る。なお、図1(b)には、金属スリーブ3とヒータ4
とをろう接するろう材106を図示してある。また、ハ
ウジング2の他端部2bには、中軸7が固定され、この
中軸7の一端部71には凹部73が形成されている。凹
部73は、ヒータ4の一端部41が配置される円形孔部
(第1部分)73aと、この円形孔部73aからさらに
円錐状に凹む円錐状孔部(第2部分)73bとから構成
されている。そして、中軸7の一端部71とヒータ4の
一端部41とが、銀ろう等のろう材104によりろう接
されている。
A heater 4 made of an insulating ceramic is fixed to one end 2a of the housing 2 via a metal sleeve 3. The housing 2 and the metal sleeve 3, and the metal sleeve 3 and the heater 4 are brazed. 1B, the metal sleeve 3 and the heater 4 are shown.
A brazing material 106 for brazing is shown. Further, the inner shaft 7 is fixed to the other end 2b of the housing 2, and a recess 73 is formed in one end 71 of the inner shaft 7. The recessed portion 73 is composed of a circular hole portion (first portion) 73a in which the one end portion 41 of the heater 4 is arranged, and a conical hole portion (second portion) 73b further recessed in a conical shape from the circular hole portion 73a. ing. The one end 71 of the center shaft 7 and the one end 41 of the heater 4 are brazed by a brazing material 104 such as silver brazing.

【0013】なお、中軸の凹部73にヒータ4を嵌合す
るために、例えば、中軸73の径D1 は4.0mm、円
形孔部73aの径D2 は3.6mm、ヒータ4の径D3
は3.5mmとしている。図1(a)に示すように、中
軸7の他端部72側は、ハウジング2から外部に突出し
ており、絶縁ブッシュ9が圧着外挿されるとともに、雄
ネジ部72aが形成され、ナット8が備えられている。
そして、絶縁ブッシュ9を介してナット8を締めつける
ことで、ハウジング2に中軸7を固定している。また、
ハウジング2と中軸7との絶縁をするために、絶縁リン
グ5およびガラス封着部6が、ハウジング2と中軸7と
の間に配されている。
In order to fit the heater 4 into the recess 73 of the center shaft, for example, the center shaft 73 has a diameter D1 of 4.0 mm, the circular hole 73a has a diameter D2 of 3.6 mm, and the heater 4 has a diameter D3.
Is 3.5 mm. As shown in FIG. 1 (a), the other end 72 side of the center shaft 7 protrudes from the housing 2 to the outside, and the insulating bush 9 is crimped and inserted, the male screw portion 72 a is formed, and the nut 8 is It is equipped.
Then, by tightening the nut 8 via the insulating bush 9, the center shaft 7 is fixed to the housing 2. Also,
An insulating ring 5 and a glass sealing portion 6 are arranged between the housing 2 and the center shaft 7 in order to insulate the housing 2 and the center shaft 7 from each other.

【0014】なお、ヒータ4は、絶縁性セラミックから
なる略円柱部材に、タングステン等の高融点金属材料か
らなる図示しない発熱線が埋設されたもので、図1
(b)において、上記発熱線の一端をヒータ4の一端部
41側端面に露出させ、ろう材104を介して中軸7の
一端部71に電気的に接続している。また、上記発熱線
の他端をヒータ4の側面部43表面に露出させ、ろう材
106を介して金属スリーブ3に電気的に接続してい
る。
The heater 4 is formed by embedding a heating wire (not shown) made of a refractory metal material such as tungsten in a substantially cylindrical member made of an insulating ceramic.
In (b), one end of the heating wire is exposed on the end surface of the heater 4 on the one end portion 41 side, and is electrically connected to one end portion 71 of the center rod 7 via the brazing material 104. The other end of the heating wire is exposed on the surface of the side surface 43 of the heater 4 and electrically connected to the metal sleeve 3 via the brazing material 106.

【0015】そして、図2に示すように、セラミックグ
ロープラグ1は、複気筒(本実施形態では4気筒)のデ
ィーゼルエンジン100の各シリンダヘッド101の雌
ネジ部100aにネジ結合されている。そして、複数本
(本実施形態では4本)のセラミックグロープラグ1を
ディーゼルエンジン100の雌ネジ部100aにネジ結
合し、電力供給用のコネクティングバー100cの複数
の貫通孔100dを、中軸7の雄ネジ部72a(図1
(a)参照)にそれぞれ同時に挿嵌した後、ナット10
0eおよびスクリューグロメット100fにより、コネ
クティングバー100cを中軸7に締めつけ固定してい
る。
As shown in FIG. 2, the ceramic glow plug 1 is screwed to the female screw portion 100a of each cylinder head 101 of the double cylinder (four cylinders in this embodiment) diesel engine 100. Then, a plurality (four in the present embodiment) of the ceramic glow plugs 1 are screwed to the female screw portion 100a of the diesel engine 100, and the plurality of through holes 100d of the connecting bar 100c for power supply are connected to the male shaft 7 of the center rod 7. Screw portion 72a (Fig. 1
(See (a)), and the nut 10
0e and the screw grommet 100f, the connecting bar 100c is fastened and fixed to the center shaft 7.

【0016】そして、雄ネジ部72aには、コネクティ
ングバー100c、プレート部材100g、およびケー
ブル100hを介して、図示しないバッテリからの電力
が供給されるようになっている。これにより、図1
(a)において、中軸7の他端部72に上記バッテリか
らの電力が供給されると、中軸7、ヒータ4の上記発熱
線、金属スリーブ3、ハウジング2、ディーゼルエンジ
ン100(図2参照)、アースの順に電流が流れ、上記
発熱線が発熱して、ディーゼルエンジン100の図示し
ない副室を加熱する。
Electric power is supplied to the male screw portion 72a from a battery (not shown) via the connecting bar 100c, the plate member 100g, and the cable 100h. As a result, FIG.
In (a), when electric power is supplied from the battery to the other end 72 of the center shaft 7, the center shaft 7, the heating wire of the heater 4, the metal sleeve 3, the housing 2, the diesel engine 100 (see FIG. 2), An electric current flows in the order of ground, and the above-mentioned heating wire generates heat to heat a sub chamber (not shown) of the diesel engine 100.

【0017】次に、上記セラミックグロープラグ1を製
造する方法を説明する。まず、図3に示すような治具1
0を準備する。この治具10は、中軸7の径よりもわず
かに大きい径の第1円形貫通部101と、金属スリーブ
3の径よりもわずかに大きい径の第2円形貫通部102
とが形成され、さらに、第1円形貫通部101の下端に
は中軸7の他端部72を支持する支持部103が形成さ
れている。なお、図中上下方向は、治具10の天地方向
と一致している。
Next, a method of manufacturing the ceramic glow plug 1 will be described. First, the jig 1 as shown in FIG.
Prepare 0. The jig 10 includes a first circular penetrating portion 101 having a diameter slightly larger than the diameter of the center shaft 7 and a second circular penetrating portion 102 having a diameter slightly larger than the diameter of the metal sleeve 3.
And a support portion 103 that supports the other end portion 72 of the center rod 7 is formed at the lower end of the first circular penetrating portion 101. Note that the vertical direction in the figure corresponds to the vertical direction of the jig 10.

【0018】そして、治具10の第1、第2円形貫通部
101、102内に、中軸7、ヒータ4、リング状のろ
う材104、リング状で半割可能な絶縁材料からなる副
治具105、金属スリーブ3、リング状のろう材106
の順に挿入してから、治具10を図示しない炉の中に配
置し、ろう接を行う。副治具105は、図1(a)に示
す組付状態において、中軸7と金属スリーブ3との間に
所定距離tを形成するためのものである。上記炉内の温
度は、ろう材104、106の融点よりも若干高い温
度、例えば、800℃で、加熱時間は例えば30分と
し、炉は10-3Torr以下に真空引きしたものを用いた。
Then, in the first and second circular penetrating portions 101, 102 of the jig 10, a sub jig made of an insulating material capable of being split into a central shaft 7, a heater 4, a ring-shaped brazing material 104, and a ring shape. 105, metal sleeve 3, ring-shaped brazing material 106
Then, the jig 10 is placed in a furnace (not shown) and brazing is performed. The sub jig 105 is for forming a predetermined distance t between the center shaft 7 and the metal sleeve 3 in the assembled state shown in FIG. The temperature in the furnace was slightly higher than the melting points of the brazing filler metals 104 and 106, for example, 800 ° C., the heating time was 30 minutes, and the furnace was evacuated to 10 −3 Torr or less.

【0019】なお、中軸7の凹部73の開口側内周面、
および、金属スリーブ3の図3中上方側内周面は面取り
がしてある。これにより、ろう材104、106が、中
軸7の凹部73とヒータ4の一端部41との間、およ
び、金属スリーブ3とヒータ4との間に確実に流動する
ようにしている。上述のようにして、中軸7とヒータ4
とのろう接、ヒータ4と金属スリーブ3とのろう接が同
時に行われ、中軸7、ヒータ4、および金属スリーブ3
が一体化される。そして、中軸7、ヒータ4、および金
属スリーブ3が一体化された組立体を治具10から取り
出し、副治具105を取り外してから、金属スリーブ3
とハウジング1の内壁とをろう接する。次いで、ハウジ
ング2の他端部2b内側に絶縁リング5を配置し、さら
に、中軸7の保持固定およびシールをするためのガラス
封着部6を形成する。その後、絶縁ブッシュ9を介して
ナット8を締めつけて、ハウジング2に中軸7を固定
し、セラミックグロープラグ1を図1(a)に示すよう
な状態に組み立てる。
The inner peripheral surface on the opening side of the recess 73 of the center shaft 7,
The inner peripheral surface of the metal sleeve 3 on the upper side in FIG. 3 is chamfered. This ensures that the brazing filler metals 104 and 106 flow between the recess 73 of the center rod 7 and the one end 41 of the heater 4 and between the metal sleeve 3 and the heater 4. As described above, the central shaft 7 and the heater 4
And the heater 4 and the metal sleeve 3 are simultaneously brazed to each other, and the center shaft 7, the heater 4 and the metal sleeve 3 are brazed.
Are integrated. Then, the assembly in which the center shaft 7, the heater 4, and the metal sleeve 3 are integrated is taken out from the jig 10, and the sub jig 105 is removed.
And the inner wall of the housing 1 by brazing. Next, the insulating ring 5 is arranged inside the other end portion 2b of the housing 2, and further, the glass sealing portion 6 for holding and fixing and sealing the center rod 7 is formed. After that, the nut 8 is tightened via the insulating bush 9 to fix the center shaft 7 to the housing 2, and the ceramic glow plug 1 is assembled in the state as shown in FIG.

【0020】そして、本実施形態によれば、ヒータ4と
中軸7とを直接ろう接しているので、接続金具を介して
ヒータ4と中軸7とを接続する従来技術に比べて、ヒー
タ4と中軸7との同軸度を大幅に向上できる。このた
め、従来技術のような、同軸度を向上させる工程を省略
できる。また、中軸7の凹部73にヒータ4を嵌合した
状態でろう接されるので、ろう接時において、ヒータ4
と中軸7とが径方向についてある程度位置決めされる。
よって、ヒータ4と中軸7との同軸度をさらに大幅に向
上できる。また、ろう接面積が凹部73の内周面に相当
するので、柱状部材の端面同志を当接させたものに比べ
てろう接面積を大きくでき、ヒータ4と中軸7との接合
強度をより強くできる。
Further, according to this embodiment, since the heater 4 and the center rod 7 are directly brazed to each other, the heater 4 and the center rod 7 are connected to each other by a brazing metal, as compared with the conventional technique in which the heater 4 and the center rod 7 are connected to each other. The coaxiality with 7 can be greatly improved. Therefore, the step of improving the coaxiality, which is required in the conventional technique, can be omitted. Further, since the heater 4 is brazed in the recess 73 of the center shaft 7 in a fitted state, the heater 4 is not attached during brazing.
And the center shaft 7 are positioned to some extent in the radial direction.
Therefore, the coaxiality between the heater 4 and the central shaft 7 can be further greatly improved. Further, since the brazing area corresponds to the inner peripheral surface of the recess 73, the brazing area can be made larger than that in which the end surfaces of the columnar members are in contact with each other, and the joint strength between the heater 4 and the center rod 7 is stronger. it can.

【0021】なお、請求項では、ヒータ4の一端部41
と中軸7の一端部71とは当接していると述べている
が、実際は、ヒータ4の一端部41と中軸7の一端部7
1との間には、ろう接時に溶融したろう材104が通る
微小隙間が存在している。以下に、中軸7とヒータ4と
の同軸性について、本実施形態のセラミックグロープラ
グ1の上記組立体(以下、本発明品と示す)と、従来
技術の組立体(以下、従来品と示す)との比較実験を行
った結果を説明する。
In the claims, the one end portion 41 of the heater 4 is
Although it is stated that the one end 71 of the center shaft 7 is in contact with the one end 71 of the heater 4 and the one end 7 of the center shaft 7 in reality.
There is a minute gap between 1 and 1 through which the brazing material 104 melted during brazing passes. Regarding the coaxiality between the center shaft 7 and the heater 4, the above-mentioned assembly of the ceramic glow plug 1 of the present embodiment (hereinafter referred to as the product of the present invention) and the assembly of the conventional technique (hereinafter referred to as the conventional product) will be described below. The result of the comparison experiment with is explained.

【0022】本発明品としては、図1(b)におい
て、中軸73の径D1 が4.0mm、円形孔部73aの
径D2 が3.6mm、円形孔部73aの高さH1 が4.
0mm、円錐状孔部73bの高さH2 が1.0mm、ヒ
ータ4の径D3 が3.5mm、金属スリーブ3からの突
出高さH3 が7.0mmのものを用いた。従来品として
は、図4(a)、(b)に示すように、中軸7の一端部
71に小径部74を形成し、この小径部74とヒータ4
の一端部41とを接続金具11により接続したものを用
いた。なお、小径部74の外径D4 (図4(b)参照)
は3.0mm、小径部74の高さH4 は5.0mmであ
る。小径部74には、その外周面から幅W1 (=0.3
mm)分だけ切り欠いた切欠部74a、74aが、2箇
所対向するように形成されている。
As the product of the present invention, in FIG. 1 (b), the diameter D1 of the center shaft 73 is 4.0 mm, the diameter D2 of the circular hole 73a is 3.6 mm, and the height H1 of the circular hole 73a is 4.
0 mm, the height H2 of the conical hole portion 73b was 1.0 mm, the diameter D3 of the heater 4 was 3.5 mm, and the protruding height H3 from the metal sleeve 3 was 7.0 mm. As a conventional product, as shown in FIGS. 4A and 4B, a small diameter portion 74 is formed at one end portion 71 of the center shaft 7, and the small diameter portion 74 and the heater 4 are provided.
The one which was connected to the one end portion 41 by the connecting fitting 11 was used. The outer diameter D4 of the small diameter portion 74 (see FIG. 4 (b))
Is 3.0 mm and the height H4 of the small diameter portion 74 is 5.0 mm. The width W1 (= 0.3
mm) are formed so as to face each other at two positions.

【0023】接続金具11の円筒部11aの内径D5 は
3.6mm、円筒部11aの高さH5 は4.0mm、直
線部の幅W2 は1.5mm、ヒータ4において円筒部1
1a内に配置されている部分の高さH6 は3.5mmで
ある。そして、ヒータ4と接続金具74の円筒部74a
とは銀ろうにてろう接され、中軸7と接続金具74の直
線部74bとは抵抗溶接されている。抵抗溶接は、圧力
Pを15kgf、投入電力を1サイクル当たり350〜
400Wとして、1サイクル行った。
The inner diameter D5 of the cylindrical portion 11a of the connecting fitting 11 is 3.6 mm, the height H5 of the cylindrical portion 11a is 4.0 mm, the width W2 of the straight portion is 1.5 mm, and the cylindrical portion 1 of the heater 4 is 1 mm.
The height H6 of the portion arranged in 1a is 3.5 mm. Then, the cylindrical portion 74a of the heater 4 and the connection fitting 74
Are brazed with silver solder, and the central shaft 7 and the straight portion 74b of the connecting fitting 74 are resistance-welded. In resistance welding, the pressure P is 15 kgf, and the input power is 350-per cycle.
One cycle was performed at 400W.

【0024】そして、本発明品および従来品を100
個ずつ準備し、それぞれについての、中軸7とヒータ4
との同軸性を評価した。因みに、金属スリーブ3を回転
軸として180°回転させたときの、中軸7の他端部7
2(図1(a)参照)側先端面の径方向に関する偏心量
により、同軸性を評価するものとする。この結果、図5
に示すように、従来品における偏心量は約1.5mm〜
4.5mmの範囲で、本発明品における偏心量は約1
mm以下であり、本発明品は従来品に比べて偏心量を
小さくできることが確認された。よって、本発明品は
従来品に比べてヒータ4と中軸7との同軸度を大幅に向
上できる。
The product of the present invention and the conventional product are 100
Prepare one by one, and the center shaft 7 and heater 4 for each
The coaxiality with was evaluated. Incidentally, the other end portion 7 of the center shaft 7 when the metal sleeve 3 is rotated by 180 ° about the rotation shaft.
The coaxiality is evaluated by the amount of eccentricity in the radial direction of the 2nd end surface (see FIG. 1A). As a result, FIG.
As shown in, the eccentricity of the conventional product is about 1.5 mm
In the range of 4.5 mm, the amount of eccentricity in the product of the present invention is about 1
It was confirmed that the product of the present invention can reduce the amount of eccentricity as compared with the conventional product. Therefore, the product of the present invention can significantly improve the coaxiality between the heater 4 and the center shaft 7 as compared with the conventional product.

【0025】ここで、本実施形態では、図2において、
コネクティングバー100cの貫通孔100dの径を5
mm、中軸7の外径を4mmに設計しているので、上記
偏心量が1mm以上であると、コネクティングバー10
0cを4つのセラミックグロープラグ1に同時に嵌合で
きない。そして、従来品は偏心量が約1.5mm〜4.
5mmの範囲であるので、中軸7とヒータ4とを接合し
た後、中軸7とヒータ4との同軸度を矯正する必要があ
るが、本発明品は上述のように同軸性を向上できるの
で、中軸7とヒータ4との同軸度を矯正する必要がな
い。
Here, in this embodiment, in FIG.
The diameter of the through hole 100d of the connecting bar 100c is 5
mm, and the outer diameter of the center shaft 7 is designed to be 4 mm. Therefore, if the eccentricity is 1 mm or more, the connecting bar 10
0c cannot be fitted to the four ceramic glow plugs 1 at the same time. The eccentricity of the conventional product is about 1.5 mm to 4.
Since it is in the range of 5 mm, it is necessary to correct the coaxiality between the central shaft 7 and the heater 4 after joining the central shaft 7 and the heater 4, but since the product of the present invention can improve the coaxiality as described above, It is not necessary to correct the coaxiality between the center shaft 7 and the heater 4.

【0026】(第2の実施形態)本実施形態は、上記第
1の実施形態において、中軸7の凹部73の円錐状孔部
73bを廃止し、円形孔部73aのみにしたものであ
る。以下に、上記本発明品、従来品、および、第2の
実施形態のセラミックグロープラグの組立体(以下、本
発明品と示す)の引張強度について比較実験を行った
結果を図6に基づいて説明する。
(Second Embodiment) In the present embodiment, the conical hole portion 73b of the recess 73 of the center shaft 7 is eliminated from the first embodiment, and only the circular hole portion 73a is provided. Below, based on FIG. 6, the results of comparative experiments were conducted on the tensile strengths of the above-mentioned present invention product, the conventional product, and the ceramic glow plug assembly of the second embodiment (hereinafter referred to as the present invention product). explain.

【0027】まず、本発明品、本発明品、および従
来品を10個ずつ準備し、それぞれの中軸7とヒータ4
とを反対方向に引っ張る引張試験を行い、引張強度を測
定した。なお、従来品では接続金具10が切断され、本
発明品および本発明品では中軸7の凹部73からヒ
ータ4が抜けた。この結果、図6に示すように、従来品
の引張強度は約12〜20kgfで、本発明品の引張
強度は約56〜63kgfで、本発明品の引張強度は
約50〜55kgfであり、本発明品および本発明品
によれば、従来品よりも引張強度を大きくできること
が確認された。よって、本発明品および本発明品
は、従来品に対してより確実にヒータ4と中軸7とを接
続できることがわかった。
First, 10 products of the present invention, 10 products of the present invention, and 10 products of the conventional product are prepared, and each of the center shaft 7 and the heater 4 is prepared.
A tensile test was conducted by pulling and in opposite directions, and the tensile strength was measured. In the conventional product, the connection fitting 10 was cut, and in the product of the present invention and the product of the present invention, the heater 4 was pulled out from the recess 73 of the center shaft 7. As a result, as shown in FIG. 6, the tensile strength of the conventional product is about 12 to 20 kgf, the tensile strength of the present invention is about 56 to 63 kgf, and the tensile strength of the present invention is about 50 to 55 kgf. It was confirmed that the invention product and the present invention product can have higher tensile strength than conventional products. Therefore, it was found that the product of the present invention and the product of the present invention can more reliably connect the heater 4 and the center shaft 7 to the conventional product.

【0028】また、本発明品のように円形孔部73a
に加えて円錐状孔部73bを形成することで、本発明品
よりもさらに引張強度を大きくできることが確認され
た。これは、円錐状孔部73bを形成することで、ヒー
タ4の一端部41側先端面にろう材104がより回りや
すくなるためであると推定される。 (他の実施形態)上記第1、第2の実施形態では、中軸
7の凹部73にヒータ4を嵌合した状態で中軸7とヒー
タ4とをろう接していたが、本発明はこれに限定される
ことはなく、中軸7の一端部71とヒータ4の一端部4
1とを直接当接させた状態でろう接するものであればよ
い。例えば、中軸7の一端部71に凹部73を形成しな
いで、単なる円柱状部材とし、この中軸7の一端部71
とヒータ4の一端部41を当接させた状態で、中軸7と
ヒータ4とをろう接してもよい。これにより、中軸7と
ヒータ4とを直接ろう接できるので、中軸7の偏心量を
従来技術に比べて小さくできる。
Further, as in the case of the present invention, the circular hole 73a
It was confirmed that the tensile strength can be further increased by forming the conical hole portion 73b in addition to the above. It is presumed that this is because forming the conical hole portion 73b makes it easier for the brazing material 104 to rotate around the end surface of the heater 4 on the one end portion 41 side. (Other Embodiments) In the first and second embodiments described above, the center shaft 7 and the heater 4 are brazed together with the heater 4 fitted in the recess 73 of the center shaft 7, but the present invention is not limited to this. The end portion 71 of the center shaft 7 and the end portion 4 of the heater 4 are not
It suffices that they are brazed in the state where they are directly contacted with each other. For example, the concave portion 73 is not formed in the one end portion 71 of the inner shaft 7, but a simple columnar member is formed.
The intermediate shaft 7 and the heater 4 may be brazed to each other with the one end 41 of the heater 4 abutted. As a result, since the center shaft 7 and the heater 4 can be directly brazed, the amount of eccentricity of the center shaft 7 can be made smaller than in the prior art.

【0029】また、上記第1の実施形態では、円錐状孔
部73bの高さを1.0mmとしていたが、これよりも
小さくしてもよいし、大きくしてもよい。なお、この高
さを0.5mm以上とするのが好ましく、これにより、
ヒータ4の一端部41の先端面に安定的にろう材104
を回すことができる。
In the first embodiment, the height of the conical hole portion 73b is 1.0 mm, but it may be smaller or larger than this. In addition, it is preferable that this height is 0.5 mm or more.
The brazing material 104 is stably attached to the tip surface of the one end portion 41 of the heater 4.
Can be turned.

【図面の簡単な説明】[Brief description of drawings]

【図1】(a)は第1の実施形態のセラミックグロープ
ラグの縦断面図で、(b)は中軸とヒータとのろう接部
分を拡大した断面図である。
FIG. 1A is a vertical cross-sectional view of a ceramic glow plug according to a first embodiment, and FIG. 1B is an enlarged cross-sectional view of a brazing portion between a center shaft and a heater.

【図2】本発明のセラミックグロープラグの取付場所を
示す分解斜視図である。
FIG. 2 is an exploded perspective view showing a mounting place of a ceramic glow plug of the present invention.

【図3】治具にヒータおよび中軸を挿入した状態の断面
図である。
FIG. 3 is a cross-sectional view showing a state where a heater and a center shaft are inserted in a jig.

【図4】(a)は中軸の偏心量の評価に用いた従来品の
要部拡大断面図で、(b)は(a)のA−A断面図であ
る。
FIG. 4A is an enlarged cross-sectional view of a main part of a conventional product used for evaluating the amount of eccentricity of a center shaft, and FIG. 4B is a cross-sectional view taken along line AA of FIG.

【図5】本発明品および従来品における中軸の偏心量
を評価した結果を示すグラフである。
FIG. 5 is a graph showing the results of evaluating the amount of eccentricity of the center shaft in the product of the present invention and the conventional product.

【図6】本発明品、本発明品、および従来品の引張
強度を評価した結果を示すグラフである。
FIG. 6 is a graph showing the results of evaluating the tensile strength of the product of the present invention, the product of the present invention, and the conventional product.

【図7】(a)は従来技術におけるセラミックグロープ
ラグの縦断面図で、(b)は接続金具の拡大斜視図であ
る。
FIG. 7A is a vertical cross-sectional view of a ceramic glow plug according to a conventional technique, and FIG. 7B is an enlarged perspective view of a connection fitting.

【符号の説明】[Explanation of symbols]

1…セラミックグロープラグ、2…ハウジング、4…ヒ
ータ、41…ヒータの一端部、7…中軸、71…中軸の
一端部。
DESCRIPTION OF SYMBOLS 1 ... Ceramic glow plug, 2 ... Housing, 4 ... Heater, 41 ... One end of a heater, 7 ... Center shaft, 71 ... One end of a center shaft.

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 ハウジング(2)と、 その一端部(41)が前記ハウジング(2)内に挿嵌さ
れるセラミック製のヒータ(4)と、 その一端部(71)が前記ヒータ(4)の前記一端部
(41)に当接するように、ハウジング(2)内に挿嵌
される通電用の中軸(7)とを備え、 前記両一端部(41)、(71)同志を直接ろう接する
ことにより、前記ヒータ(4)と前記中軸(7)とを接
続することを特徴とするセラミックグロープラグ。
1. A housing (2), a ceramic heater (4) having one end (41) inserted in the housing (2), and one end (71) of the heater (4). And a middle shaft (7) for energization inserted into the housing (2) so as to come into contact with the one end portion (41), and the both end portions (41) and (71) are directly brazed to each other. The ceramic glow plug is characterized in that the heater (4) and the center rod (7) are thereby connected.
【請求項2】 前記中軸(7)および前記ヒータ(4)
のいずれか一方の一端部(71)には凹部(73)が形
成されており、 前記中軸(7)および前記ヒータ(4)のいずれか他方
の一端部(41)を、前記凹部(73)に嵌合した状態
で、前記両一端部(41)、(71)同志を直接ろう接
することにより、前記ヒータ(4)と前記中軸(7)と
を接続することを特徴とする請求項1に記載のセラミッ
クグロープラグ。
2. The center shaft (7) and the heater (4)
A concave portion (73) is formed at one end portion (71) of one of the two, and the other end portion (41) of the center pole (7) and the heater (4) is formed into the concave portion (73). The heater (4) and the center rod (7) are connected to each other by directly brazing the both ends (41) and (71) in a state of being fitted to each other. The described ceramic glow plug.
【請求項3】 前記凹部(73)は、前記他方の一端部
(41)が配置される第1部分(73a)と、この第1
部分(73a)よりも断面積が小さく、前記他方の一端
部(41)の先端側に形成される第2部分(73b)と
により構成されていることを特徴とする請求項2に記載
のセラミックグロープラグ。
3. The recess (73) includes a first portion (73a) in which the other end (41) is arranged, and the first portion (73a).
The ceramic according to claim 2, wherein the ceramic has a cross-sectional area smaller than that of the portion (73a) and is constituted by a second portion (73b) formed on the tip side of the other end portion (41). Glow plug.
JP9444696A 1996-04-16 1996-04-16 Ceramic glow plug Pending JPH09280563A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9444696A JPH09280563A (en) 1996-04-16 1996-04-16 Ceramic glow plug

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9444696A JPH09280563A (en) 1996-04-16 1996-04-16 Ceramic glow plug

Publications (1)

Publication Number Publication Date
JPH09280563A true JPH09280563A (en) 1997-10-31

Family

ID=14110496

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9444696A Pending JPH09280563A (en) 1996-04-16 1996-04-16 Ceramic glow plug

Country Status (1)

Country Link
JP (1) JPH09280563A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002310428A (en) * 2001-04-06 2002-10-23 Bosch Automotive Systems Corp Method for manufacturing ceramics heater type glow plug
JP2002364845A (en) * 2001-06-07 2002-12-18 Ngk Spark Plug Co Ltd Glow plug and its manufacturing method
JP2012047366A (en) * 2010-08-25 2012-03-08 Ngk Spark Plug Co Ltd Glow plug
JP2014142122A (en) * 2013-01-24 2014-08-07 Ngk Spark Plug Co Ltd Glow plug
JP2014211277A (en) * 2013-04-19 2014-11-13 日本特殊陶業株式会社 Glow plug

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002310428A (en) * 2001-04-06 2002-10-23 Bosch Automotive Systems Corp Method for manufacturing ceramics heater type glow plug
JP2002364845A (en) * 2001-06-07 2002-12-18 Ngk Spark Plug Co Ltd Glow plug and its manufacturing method
JP4672910B2 (en) * 2001-06-07 2011-04-20 日本特殊陶業株式会社 Glow plug manufacturing method
JP2012047366A (en) * 2010-08-25 2012-03-08 Ngk Spark Plug Co Ltd Glow plug
JP2014142122A (en) * 2013-01-24 2014-08-07 Ngk Spark Plug Co Ltd Glow plug
JP2014211277A (en) * 2013-04-19 2014-11-13 日本特殊陶業株式会社 Glow plug

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