JP3885311B2 - Glow plug and manufacturing method thereof - Google Patents

Glow plug and manufacturing method thereof Download PDF

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JP3885311B2
JP3885311B2 JP27355397A JP27355397A JP3885311B2 JP 3885311 B2 JP3885311 B2 JP 3885311B2 JP 27355397 A JP27355397 A JP 27355397A JP 27355397 A JP27355397 A JP 27355397A JP 3885311 B2 JP3885311 B2 JP 3885311B2
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press
heater
fitting
housing
metal tube
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JPH1194253A (en
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哲也 渡辺
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Denso Corp
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Description

【０００１】
【技術分野】
本発明は，ディーゼルエンジンの予熱に用いるグロープラグ及びその製造方法に関する。
【０００２】
【従来技術】
ディーゼルエンジン予熱用のグロープラグとしては，図８に示すごとく，シーズ型のグロープラグ９がある。
グロープラグ９は，同図に示すごとく，先端を閉止した断面Ｕ字状の金属チューブ９１内に絶縁粉末２を充填するとともに，発熱用のヒートコイル３を収納したヒータ９０を有している。また，ヒータ９０には，金属チューブ９１の開口端から通電用の中軸４の先端を絶縁粉末２内に埋設してこれを一体的に連結してある。
【０００３】
また上記ヒートコイル３は，同図に示すごとく，その一端３１を金属チューブ９１の先端内面に接合してあると共に，他端３２を中軸４の先端に接続してある。
そして，ヒータ９０とハウジング５とは，ヒータ９０の圧入部９５をハウジング５の嵌合部５５に圧入嵌合させて固定してある。なお，図８における符号７１はナット，７２は樹脂製ブッシュ，７３は絶縁弾性材料からなるＯリング，７４は樹脂性ワッシャーである。
【０００４】
このグロープラグ９を製造するに当たっては，図９に示すごとく，まず上記金属チューブ９１へのヒートコイル３及び中軸４の挿入工程，絶縁粉末の充填工程，金属チューブ９１全体を外周から加圧縮径させるスエージング加工工程を経て，中軸４を一体的に接合したヒータ９０を作製する。このとき，金属チューブ９１の開口端９１２には，自然な感じで滑らかに形成された曲面部（自然Ｒ部）が形成される。その後，ヒータ９０とハウジング５との圧入固定を行う。
【０００５】
ヒータ９０とハウジング５との圧入工程を行うに当たっては，図１０に示すごとく，まずハウジング５のヒータ挿入口５１を上方に向けてハウジング固定治具８５に強固にセットする。次いで，ハウジング５のヒータ挿入口５１から中軸４及びヒータ９０の一体品を挿入する。
【０００６】
次いで，ヒータ９０の先端部をヒータ押圧治具８１により押圧し，自然Ｒが形成された開口端９１２から圧入部９５をハウジング５の嵌合部５５に圧入嵌合させ，両者を固定する。
尚，従来の圧入固定方法としては，例えば特開昭５２−１０７４４６号公報に示された方法等もある。
【０００７】
【解決しようとする課題】
しかしながら，上記従来のグロープラグ及びその製造方法には，次の問題がある。
即ち，ヒータ９０とハウジング５とは，単に仮組みしただけではこれらの軸芯を一致させることが困難である。そのため，これらの軸芯を一致させるためにはヒータ押圧治具８１とハウジング固定治具８５とを用いる。そして，これらの治具の位置関係を極めて正確に設定することが必要となる。これらの治具の位置関係の精度向上と調整には，ある程度の時間が必要であり，製造工程合理化の妨げになっている。
【０００８】
また，ヒータ９０とハウジング５と軸芯がずれた状態で仮組された場合に，そのまま圧入固定を行った場合には，ヒータ９０とハウジング５とが芯ずれした状態のグロープラグができあがってしまう。
また，上記ヒータ９０の製造過程においては上記のごとくスエージングを行うので，金属チューブ９１は縮径に伴ってその長さが伸びる。しかしながら，伸びる長さは必ずしも一定ではなく，ある程度のばらつきが発生する。そのため，ヒータ９０とハウジング５とを圧入固定した場合に，ハウジング５のヒータ挿入口５１から突出するヒータ９０の長さを一定とする場合，圧入部長さのばらつきが圧入荷重のばらつきになってしまうため，圧入荷重の過不足による不具合も発生しうる。
【０００９】
さらに，ヒータ９０をハウジング５に圧入するとヒータ９０の圧入部９５，即ち金属チューブ９１の開口端部近傍が圧縮，縮径される。このとき，均等な縮径が行われずに中軸４の位置が偏芯した場合には，金属チューブ９１の開口端と中軸４とが非常に近づいて両者の絶縁性が低下するという不具合も発生しうる。
【００１０】
このような芯ずれしたグロープラグ，ヒータの圧入荷重がばらついたグロープラグ，絶縁性の低下したグロープラグは，いずれも不良品となりうる。
即ち，従来の製造方法は，品質面でのばらつきも発生させていた。
【００１１】
本発明は，かかる従来の問題点に鑑みてなされたもので，ハウジングとヒータとの仮組み時の芯出しを容易に行うことができ，かつ，品質の安定化を図ることができるグロープラグ及びその製造方法を提供しようとするものである。
【００１２】
【課題の解決手段】
請求項１の発明は，内孔を設けたハウジングと，該ハウジングの上記内孔内に圧入固定したヒータと，該ヒータへの通電を行うための中軸とを有し，かつ，上記ハウジングと上記ヒータとの圧入固定は，上記ハウジングの内孔内に設けた嵌合部と上記ヒータの外周に設けた圧入部とを圧入嵌合させて行っており，
上記ヒータは，上記圧入部を設けた金属チューブと，該金属チューブ内に充填した絶縁粉末と，該絶縁粉末内に埋設したヒートコイルとを有しており，
該ヒートコイルは，その一端が上記金属チューブの先端内面に，その他端が上記中軸の先端にそれぞれ溶接してあり，
上記中軸の先端部分は，上記圧入部の内周側を通って上記絶縁粉末内に埋設してあり，
上記金属チューブにおいて上記圧入部を設けた側とは反対側の先端部には，当該金属チューブの一般部の外径よりも縮径した縮径部が形成してあるグロープラグを製造する方法において，
上記中軸と上記ヒータとを一体化させる一体化工程と，
上記ヒータの上記圧入部に切削を施し，上記嵌合部の内径よりも小さい外径を有するガイド部と，該ガイド部と上記圧入部とを結ぶテーパ面を有する挿入テーパ部を設けるガイド部形成工程と，
上記ハウジングの上記嵌合部の先端部に，上記ヒータにおける上記挿入テーパ部の軸方向に対する傾斜角度よりも大きい傾斜角度を有する嵌合テーパ部を設ける嵌合テーパ部形成工程と，
上記ガイド部を上記嵌合部内に挿入すると共に，上記挿入テーパ部を上記嵌合部と上記嵌合テーパ部との間の角部に当接させて，当該ヒータの軸芯と当該ハウジングの軸芯とを合わせた後，上記圧入部の表面を上記嵌合部と上記嵌合テーパ部との間の角部によって削って当該圧入部を当該嵌合部内に圧入することにより，当該ヒータを当該ハウジングに圧入固定する圧入工程とを含むことを特徴とするグロープラグの製造方法にある。
【００１３】
本発明において最も注目すべきことは，上記圧入工程の前には予め上記ガイド部形成工程を行うことである。即ち，ヒータには，予め上記ガイド部と上記挿入テーパ部とを設けることである。
【００１４】
上記ガイド部形成工程においては，ヒータの挿入側端部近傍を切削又は研削加工する。そしてその切削量又は研削量を調整することにより，上記ガイド部と挿入テーパ部とを隣接配置させて形成する。これにより，ヒータには，その挿入側端部から，ガイド部，挿入テーパ部，圧入部が形成される。
また，上記圧入工程においては，ヒータをハウジングの内孔内に挿入して仮組みした後に，両者を押圧して圧入固定する。
【００１５】
次に，本発明の作用効果につき説明する。
本発明のグロープラグの製造方法においては，上記ガイド部形成工程を行う。そのため，圧入工程時においては，ハウジングとヒータとの仮組の段階において容易に両者の軸芯合わせを行うことができる。
【００１６】
即ち，ガイド部形成工程を行うことにより，上記ヒータには，上記のごとく，挿入側端部からガイド部，挿入テーパ部，圧入部が形成される。そのため，ヒータとハウジングとを仮組みした場合には，まずガイド部がハウジングの嵌合部に挿入され，ヒータの軸芯とハウジングの軸芯とが一致する方向に導かれる。そして，嵌合部の先端にヒータの挿入テーパ部が当接することによって，テーパ面のセンターリング効果によってさらにヒータとハウジングとの軸芯が一致する方向に導かれる。
即ち，ヒータとハウジングとは，これらを単に仮組みするだけで容易に両者の軸芯合わせを行うことができる。
【００１７】
また，圧入工程は，上記のごとくヒータとハウジングとが精度よく軸芯合わせされた状態で行われる。そのため，得られるグロープラグにおいては，ヒータとハウジングとの軸芯が精度よく一致したものとなる。
【００１８】
また，ヒータにおける圧入部は，上記ガイド部形成工程において上記ガイド部及び挿入テーパ部を設けることにより位置決めされる。そのため，ヒータの製造過程においてヒータの長さにばらつきが生じた場合においても，ガイド部形成工程においてガイド部及び挿入テーパ部の形成位置を調整することにより，ヒータ先端から圧入部までの距離を常に一定に調整することができる。それ故，得られるグロープラグにおいては，ヒータの圧入荷重の均一化を図ることができる。
【００１９】
このように，本発明の製造方法によれば，ヒータとハウジングとの軸芯合わせを非常に短時間でかつ容易に行うことができ，さらに，芯ずれしたグロープラグ，ヒータの圧入荷重がばらついて荷重過大によるヒータ曲がり等の不良品の発生を防止することができる。
【００２０】
それ故，本発明によれば，ハウジングとヒータとの仮組み時の芯出しを容易に行うことができ，かつ，品質の安定化を図ることができるグロープラグの製造方法を提供することができる。
【００２１】
上記ガイド部形成工程においては，上記圧入部に切削を施して該圧入部を所定の外径寸法に加工する。これにより，圧入部の外径寸法及び真円度を非常に精度よく仕上げることができる。それ故，寸法精度又は真円度に起因する圧入条件（必要荷重等）の悪化を抑制することができ，常に安定した圧入固定を行うことができる。
【００２２】
また，上記ガイド部の長さは３ｍｍ以上であることが好ましい。３ｍｍ未満の場合にはハウジングとヒータとの仮組み時の芯出しが十分に行えないという問題がある。
【００２３】
また，上記ハウジングの上記嵌合部の先端部には，上記ヒータにおける挿入テーパ部の軸方向に対する傾斜角度よりも大きい傾斜角度を有する嵌合テーパ部を予め設けている。これにより，圧入工程における圧入作業をスムーズかつ容易にすることができる。
ここに，上記嵌合部の先端部とは，ハウジングのヒータ挿入口寄りの端部，即ち，ヒータをハウジング内に挿入した際にヒータの挿入テーパ部と当接する端部をいう。
また，請求項２の発明のように，上記圧入工程においては，ハウジング保持具上に上記ハウジングを載置し，該ハウジングの上記内孔内に上記中軸と一体化させた上記ヒータを挿入するときに，上記ガイド部を上記嵌合部内に挿入して，当該ヒータの軸芯と当該ハウジングの軸芯とを合わせ，その後，ヒータ固定治具における有底内孔内に，上記ヒータにおける上記金属チューブの上記一般部の一部及び上記縮径部を挿入し，当該ヒータ固定治具により当該ヒータを押圧することにより，上記圧入部を上記嵌合部内に圧入することが好ましい。
【００２４】
次に，上記優れた製造方法により得られたグロープラグとしては，次の発明がある。
即ち，請求項３の発明のように，内孔を設けたハウジングと，該ハウジングの上記内孔内に圧入固定したヒータと，該ヒータへの通電を行うための中軸とを有し，かつ，上記ハウジングと上記ヒータとの圧入固定は，上記ハウジングの内孔内に設けた嵌合部と上記ヒータの外周に設けた圧入部とを圧入嵌合させて行っているグロープラグにおいて，
上記ヒータは，上記圧入部を設けた金属チューブと，該金属チューブ内に充填した絶縁粉末と，該絶縁粉末内に埋設したヒートコイルとを有しており，上記圧入部は，切削により形成してあり，
該ヒートコイルは，その一端が上記金属チューブの先端内面に，その他端が上記中軸の先端にそれぞれ溶接してあり，
上記中軸の先端部分は，上記圧入部の内周側を通って上記絶縁粉末内に埋設してあり，
上記金属チューブにおいて上記圧入部を設けた側とは反対側の先端部には，当該金属チューブの一般部の外径よりも縮径した縮径部が形成してあり，
上記ヒータの挿入側端部と上記圧入部との間には，上記嵌合部の内径よりも小さい外径を有するガイド部と，該ガイド部と上記圧入部とを結ぶテーパ面を有する挿入テーパ部とが設けてあり，
上記ハウジングの上記嵌合部の先端部には，嵌合テーパ部が設けてあり，該嵌合テーパ部の傾斜角度は，上記ヒータにおける挿入テーパ部の軸方向に対する傾斜角度よりも大きくしてあることを特徴とするグロープラグがある。
【００２５】
本発明のグロープラグにおいて注目すべきことは，上記ヒータには，上記ガイド部と上記挿入テーパ部とを設けてあることである。
これにより，本発明のグロープラグは，上述した優れた製造方法により容易に製造することができ，寸法精度が高く，高品質の特性を得ることができる。
【００２６】
【発明の実施の形態】
実施形態例
本発明の実施形態例にかかるグロープラグ及びその製造方法につき，図１〜図７を用いて説明する。
本例のグロープラグ１は，図１に示すごとく，内孔５０を設けたハウジング５と，ハウジング５の内孔５０内に圧入固定したヒータ１０と，該ヒータ１０への通電を行うための中軸４とを有している。
【００２７】
また，図１に示すごとく，ハウジング５とヒータ１０との圧入固定は，ハウジング５の内孔５０に設けた嵌合部５５とヒータ１０の外周に設けた圧入部１５とを圧入嵌合させて行っている。
そして，ヒータ１０の挿入側端部１１２と圧入部１５との間には，ハウジング５の嵌合部５５の内径よりも小さい外径を有するガイド部１７と，ガイド部１７と圧入部１５とを結ぶテーパ面を有する挿入テーパ部１６を設けてある。
【００２８】
また，ヒータ１０は，図１に示すごとく，先端１１１を閉止した断面Ｕ字状の金属チューブ１１と，金属チューブ１１内に充填した絶縁粉末２を介して収納したヒートコイル３とよりなる。
また，中軸４はその先端４１をヒータ１０の挿入側端部（金属チューブ１１の開口端）１１２から絶縁粉末２内に埋設させてある。また，ヒートコイル３は，その一端３１を金属チューブ１１の先端内面に，他端３２を中軸４の先端にそれぞれ溶接してある。その他は，従来例と同様である。
【００２９】
次に，このグロープラグ１の製造方法につき説明する。
本例においては，まず，ヒータ１０用の金属チューブ１１を準備すると共に，予めヒートコイル３の一端を溶接した中軸４を準備する。次いで，ヒートコイル３を金属チューブ１１内に挿入すると共にヒートコイル３の他端と金属チューブ１１の先端１１１の内面を溶接する。
【００３０】
次いで，金属チューブ１１内に，上記ヒートコイル３及び中軸４の先端を埋めるように絶縁粉末２としてのマグネシア（ＭｇＯ）粉末を充填する。
次いで，金属チューブ１１の外周面からスエージング加工をおこない，金属チューブ１１を圧縮し，縮径させる。これにより，金属チューブ１１内の絶縁粉末２の充填密度が向上すると共に，中軸４とヒータ１０とが一体化する。
【００３１】
次に，ヒータ１０に対してガイド部形成工程を行う。
具体的には，図２に示すごとく，金属チューブ１１における圧入部１５となるべき部分から開口端１１２まで（点線部分）を研削又は切削加工し，圧入部１５，挿入テーパ部１６，ガイド部１７を形成する。このとき，圧入部１５の位置は，ヒータ１０の先端１１１からの距離が常に一定の距離Ｌ（図２）となるよう設ける。そして，上記スエージング加工に伴う金属チューブ１１の長さばらつきは，ガイド部の長さ変動によって吸収する。本例においては，ガイド部の長さを３ｍｍ以上の範囲で変動させることによって圧入部１５の位置を一定の位置に調整した。
【００３２】
次に，図３に示すごとく，ハウジング５を準備し，ヒータ１０をハウジング５に圧入固定する圧入工程を行う。
ハウジング５は，図３に示すごとく，その軸芯方向に貫通する内孔５０を有すると共に，ヒータ挿入口５１から内部へ少し入った所に嵌合部５５を有している。また，嵌合部５５の先端部，即ちヒータ挿入口５１寄りの端部には，拡開したテーパ面を有する嵌合テーパ部５６を設けてある。なお，嵌合テーパ部５６の軸芯方向に対する傾斜角度βは，図４に示すごとく，ヒータ１０における挿入テーパ部１６の傾斜角度αよりも大きくしてある。
【００３３】
そして，圧入工程を行うに当たっては，図３に示すごとく，ヒータ挿入口５１を上方に向けてハウジング５をハウジング保治具８６上に載置する。ハウジング保治具８６は，従来のものと異なり，ハウジング５を水平方向に拘束するものではなく，ハウジング５の内孔５０と同軸線上に中軸４の外径よりも十分大きくかつハウジング５の外径よりも小さい貫通穴８６０を有するものである。
【００３４】
次いで，図５に示すごとく，ヒータ１０を，中軸４を先頭にしてハウジング５の内孔内に挿入し，仮組みする。このとき，ヒータ１０とハウジング５との軸芯がずれている場合には，ヒータ１０のガイド部１７がハウジング５の嵌合部５５に挿入された時点で修正される。また，ヒータ１０の挿入テーパ部１６とハウジング５の嵌合テーパ部５６とが当接した時点においても，さらに両者の軸芯のずれが修正される。
【００３５】
次に，図６に示すごとく，ヒータ１０とハウジング５との仮組が完了した時点で，ヒータ固定治具８１によりヒータ１０を強く押圧し，その圧入部１５をハウジング５の嵌合部５５に圧 嵌合させる。これにより，同図に示すごとく，ヒータ１０とハウジング５とが強固に一体化されたグロープラグ１が得られる。
なお，図１に示すごとく，ハウジング５の中軸突出側には，従来と同様に，ナット７１，樹脂性ブッシュ７２，絶縁弾性材料からなるＯリング７３，樹脂性ワッシャー７４を配設する。
【００３６】
このようにして得られたグロープラグ１は，従来のグロープラグに比べて非常に品質的に安定し，かつ高い能率で製造することができる。
即ち，上記のごとくヒータ１０に対して予めガイド部形成工程を行うことによって，ヒータ１０とハウジング５とを仮組みするだけで容易に両者の軸芯を一致させることができる。それ故，圧入工程において軸芯合わせに必要な時間を従来よりも格段に短くすることができ，グロープラグの製造を高能率化することができる。
【００３７】
また，上記軸芯合わせを確実に行うことができるため，ヒータ１０とハウジング５とが芯ずれしたグロープラグの発生を防止することができる。また，ヒータ１０の製造過程におけるスエージング加工に伴う長さばらつきの影響を容易に回避することができ，ヒータ１０の突出長さを常に一定にした圧入を安定して容易に行うことができる。
【００３８】
また，金属チューブ１１の開口端（ヒータ１０の挿入側端部）１１２と圧入部１５とは，上記ガイド部１７及び挿入テーパ部１６の存在により一定距離離れて配置されている。そのため，圧入固定によって圧入部１５が縮径された場合においても，金属チューブ１１の開口端１１２はほとんど縮径されることがない。それ故，金属チューブ１１と中軸４との絶縁性を維持することができる。
【００３９】
さらに，本例においては，圧入部１５についても切削加工を施している。そのため，圧入部は高い真円度を有している。また，図４に示すごとく，ヒータ１０の挿入テーパ部１６の傾斜角度αとハウジング５の嵌合テーパ部５６の傾斜角度βを，α＜β＜４５°の関係に設定してある。それ故，圧入工程時における，圧入条件は安定し，そのため，常に安定した圧入固定部を得ることができる。
【００４０】
なお，圧入部１５の真円度等がスエージング加工後に十分な精度で得られる場合には，圧入部の切削加工を省略することができることは言うまでもない。即ち，図７に示すごとく，ヒータ１０の形状を２段形状，即ち，圧入部１５をヒータ１０の本体部と同じ外径とし，ガイド部１７を一段小径化した形状とすることができる。そして，この場合も上記と同様の効果が得られる。
【図面の簡単な説明】
【図１】実施形態例にかかるグロープラグの一部切り欠き断面図。
【図２】実施形態例における，ヒータと中軸の一体品を示す説明図。
【図３】実施形態例における，ハウジングをハウジング保治具に載置した状態を示す説明図。
【図４】実施形態例における，ヒータの挿入テーパ部とハウジングの嵌合テーパ部との傾斜角度の関係を示す説明図。
【図５】実施形態例における，ヒータとハウジングとの仮組状態を示す説明図。
【図６】実施形態例における，ヒータとハウジングとの圧入固定時を示す説明図。
【図７】実施形態例における，ヒータ形状の別例を示す説明図。
【図８】従来例にかかるグロープラグの一部切り欠き断面図。
【図９】従来例における，ヒータと中軸の一体品を示す説明図。
【図１０】従来例における，ヒータとハウジングとの圧入固定時を示す説明図。
【符号の説明】
１．．．グロープラグ，
１０．．．ヒータ，
１１．．．金属チューブ，
１５．．．圧入部，
１６．．．挿入テーパ部，
１７．．．ガイド部，
２．．．絶縁粉末，
３．．．ヒートコイル，
４．．．中軸，
５．．．ハウジング，
５０．．．内孔，
５５．．．嵌合部，
５６．．．嵌合テーパ部，[0001]
【Technical field】
The present invention relates to a glow plug used for preheating a diesel engine and a method for manufacturing the same.
[0002]
[Prior art]
As a glow plug for diesel engine preheating, there is a seeds-type glow plug 9 as shown in FIG.
As shown in the figure, the glow plug 9 has a heater 90 in which the insulating powder 2 is filled in a metal tube 91 having a U-shaped cross-section with its tip closed, and the heat coil 3 for heating is housed. In addition, the heater 90 has the tip of the middle shaft 4 for energization embedded in the insulating powder 2 from the opening end of the metal tube 91 and integrally connected thereto.
[0003]
The heat coil 3 has one end 31 bonded to the inner surface of the tip end of the metal tube 91 and the other end 32 connected to the tip end of the middle shaft 4 as shown in FIG.
The heater 90 and the housing 5 are fixed by press-fitting and fitting the press-fitting portion 95 of the heater 90 to the fitting portion 55 of the housing 5. In FIG. 8, reference numeral 71 is a nut, 72 is a resin bush, 73 is an O-ring made of an insulating elastic material, and 74 is a resin washer.
[0004]
In manufacturing the glow plug 9, as shown in FIG. 9, first, the heat coil 3 and the center shaft 4 are inserted into the metal tube 91, the insulating powder is filled, and the entire metal tube 91 is compressed and compressed from the outer periphery. Through the swaging process, a heater 90 in which the middle shaft 4 is integrally joined is manufactured. At this time, the open end 912 of the metal tube 91 is formed with a curved surface portion (natural R portion) that is smoothly formed with a natural feeling. Thereafter, the heater 90 and the housing 5 are press-fitted and fixed.
[0005]
In performing the press-fitting process of the heater 90 and the housing 5, as shown in FIG. 10, first, the heater insertion port 51 of the housing 5 is set firmly on the housing fixing jig 85 with the heater insertion port 51 facing upward. Next, an integrated product of the middle shaft 4 and the heater 90 is inserted from the heater insertion port 51 of the housing 5.
[0006]
Next, the front end portion of the heater 90 is pressed by the heater pressing jig 81, and the press-fit portion 95 is press-fitted and fitted into the fitting portion 55 of the housing 5 from the opening end 912 where the natural R is formed, and both are fixed.
As a conventional press-fitting and fixing method, for example, there is a method disclosed in Japanese Patent Laid-Open No. 52-107446.
[0007]
[Problems to be solved]
However, the conventional glow plug and the manufacturing method thereof have the following problems.
That is, it is difficult to align the axes of the heater 90 and the housing 5 simply by temporarily assembling them. Therefore, the heater pressing jig 81 and the housing fixing jig 85 are used in order to make these axes coincide. And it is necessary to set the positional relationship of these jigs extremely accurately. A certain amount of time is required to improve and adjust the positional relationship of these jigs, which hinders the rationalization of the manufacturing process.
[0008]
In addition, when the heater 90 and the housing 5 are temporarily assembled with the shaft center shifted, if the press fitting is performed as it is, a glow plug in which the heater 90 and the housing 5 are misaligned is completed. .
Further, since the swaging is performed as described above in the manufacturing process of the heater 90, the length of the metal tube 91 increases with the diameter reduction. However, the extending length is not always constant, and some variation occurs. For this reason, when the heater 90 and the housing 5 are press-fitted and fixed, if the length of the heater 90 protruding from the heater insertion port 51 of the housing 5 is constant, the variation in the press-fit portion becomes the variation in the press-fit load. For this reason, problems due to excessive or insufficient press-fit loads may occur.
[0009]
Further, when the heater 90 is press-fitted into the housing 5, the press-fitting portion 95 of the heater 90, that is, the vicinity of the opening end of the metal tube 91 is compressed and reduced in diameter. At this time, if the position of the center shaft 4 is decentered without uniform diameter reduction, the opening end of the metal tube 91 and the center shaft 4 are very close to each other, resulting in a problem that the insulation between them decreases. sell.
[0010]
Such misaligned glow plugs, glow plugs with varying heater press-fit loads, and glow plugs with poor insulation can all be defective.
That is, the conventional manufacturing method has also caused variations in quality.
[0011]
The present invention has been made in view of such conventional problems, and a glow plug that can easily perform centering during temporary assembly of a housing and a heater and can stabilize quality. The manufacturing method is intended to be provided.
[0012]
[Means for solving problems]
The invention of claim 1 includes a housing provided with an inner hole, a heater press-fitted and fixed in the inner hole of the housing, a center shaft for energizing the heater, and the housing and the above Press fitting with the heater is performed by press fitting the fitting portion provided in the inner hole of the housing and the press fitting portion provided on the outer periphery of the heater.
The heater includes a metal tube provided with the press-fitting portion, an insulating powder filled in the metal tube, and a heat coil embedded in the insulating powder.
One end of the heat coil is welded to the inner surface of the tip of the metal tube, and the other end is welded to the tip of the middle shaft.
The tip portion of the middle shaft is embedded in the insulating powder through the inner peripheral side of the press-fit portion,
In the method of manufacturing a glow plug, wherein the metal tube has a reduced diameter portion formed at the tip opposite to the side where the press-fitting portion is provided, which is smaller than the outer diameter of the general portion of the metal tube. ,
An integration step of integrating the middle shaft and the heater;
Guide part formation in which the press-fitted part of the heater is cut and a guide part having an outer diameter smaller than the inner diameter of the fitting part and an insertion taper part having a tapered surface connecting the guide part and the press-fitted part are provided. Process,
A fitting taper forming step in which a fitting taper portion having an inclination angle larger than an inclination angle with respect to an axial direction of the insertion taper portion in the heater is provided at a distal end portion of the fitting portion of the housing;
The guide portion is inserted into the fitting portion, and the insertion taper portion is brought into contact with a corner portion between the fitting portion and the fitting taper portion so that the heater shaft and the housing shaft are inserted. after combination of the core, by press-fitting the press-fit portion by cutting the corner portion between said fitting portion of the surface of the press-fit portion and the fitting tapered portion in the fitting portion, the said heater in the manufacturing method of the glow plug which comprises a press-fitting step of press-fitted into the housing.
[0013]
The most notable point in the present invention is that the guide portion forming step is performed in advance before the press-fitting step. That is, the heater is provided with the guide portion and the insertion taper portion in advance.
[0014]
In the guide part forming step, the vicinity of the insertion side end of the heater is cut or ground. Then, by adjusting the cutting amount or grinding amount, the guide portion and the insertion taper portion are formed adjacent to each other. Thereby, a guide part, an insertion taper part, and a press-fit part are formed in the heater from the insertion side end.
In the press-fitting step, after the heater is inserted into the inner hole of the housing and temporarily assembled, both are pressed and fixed.
[0015]
Next, the effects of the present invention will be described.
In the method for manufacturing a glow plug according to the present invention, the guide part forming step is performed. Therefore, during the press-fitting process, the axes can be easily aligned at the temporary assembly stage of the housing and the heater.
[0016]
That is, by performing the guide portion forming step, as described above, the guide portion, the insertion taper portion, and the press-fitting portion are formed in the heater from the insertion side end portion. For this reason, when the heater and the housing are temporarily assembled, the guide portion is first inserted into the fitting portion of the housing, and is guided in a direction in which the axis of the heater and the axis of the housing coincide. Then, when the insertion taper portion of the heater comes into contact with the tip of the fitting portion, the centering effect of the taper surface leads to the direction in which the axis of the heater and the housing further coincide.
That is, the heater and the housing can be easily aligned with each other simply by temporarily assembling them.
[0017]
Further, the press-fitting process is performed in a state where the heater and the housing are accurately aligned with each other as described above. For this reason, in the obtained glow plug, the axis of the heater and the housing are precisely aligned.
[0018]
The press-fitting portion of the heater is positioned by providing the guide portion and the insertion taper portion in the guide portion forming step. Therefore, even when the heater length varies in the heater manufacturing process, the distance from the tip of the heater to the press-fitted part is always adjusted by adjusting the formation position of the guide part and the insertion taper part in the guide part formation process. It can be adjusted to a certain level. Therefore, in the obtained glow plug, the press-fit load of the heater can be made uniform.
[0019]
As described above, according to the manufacturing method of the present invention, the centering of the heater and the housing can be easily performed in a very short time, and the glow plug with the misalignment and the press-fit load of the heater vary. It is possible to prevent the occurrence of defective products such as a bent heater due to an excessive load.
[0020]
Therefore, according to the present invention, it is possible to provide a method for manufacturing a glow plug that can easily perform centering during temporary assembly of the housing and the heater and can stabilize the quality. .
[0021]
In the guide portion forming step, the press-fit portion is cut to process the press-fit portion into a predetermined outer diameter . As a result , the outer diameter and roundness of the press-fit portion can be finished very accurately. Therefore, deterioration of the press-fitting conditions (necessary load, etc.) due to dimensional accuracy or roundness can be suppressed, and stable press-fitting can always be performed.
[0022]
Moreover , it is preferable that the length of the said guide part is 3 mm or more. If it is less than 3 mm, there is a problem that the centering at the time of temporary assembly of the housing and the heater cannot be performed sufficiently.
[0023]
Further, the distal end of the fitting portion of the housing is in advance provided with fitting tapered portion having a larger inclination angle than the inclination angle with respect to the axial direction of the insertion taper portion of the heater. Thereby, the press-fitting work in the press-fitting process can be made smooth and easy.
Here, the front end portion of the fitting portion refers to an end portion near the heater insertion opening of the housing, that is, an end portion that comes into contact with the insertion taper portion of the heater when the heater is inserted into the housing.
According to a second aspect of the present invention, in the press-fitting step, the housing is placed on a housing holder, and the heater integrated with the center shaft is inserted into the inner hole of the housing. Then, the guide portion is inserted into the fitting portion, the shaft core of the heater and the shaft core of the housing are aligned, and then the metal tube in the heater is inserted into the bottomed inner hole of the heater fixing jig. It is preferable to press-fit the press-fitting part into the fitting part by inserting a part of the general part and the reduced diameter part and pressing the heater with the heater fixing jig.
[0024]
Next, as a glow plug obtained by the above excellent manufacturing method, there is the following invention.
That is, as in the invention of claim 3 , it has a housing provided with an inner hole, a heater press-fitted and fixed in the inner hole of the housing, a center shaft for energizing the heater, and In the glow plug in which the housing and the heater are press-fitted and fixed by press-fitting the fitting portion provided in the inner hole of the housing and the press-fitting portion provided on the outer periphery of the heater,
The heater includes a metal tube provided with the press-fit portion, an insulating powder filled in the metal tube, and a heat coil embedded in the insulating powder. The press-fit portion is formed by cutting. And
One end of the heat coil is welded to the inner surface of the tip of the metal tube, and the other end is welded to the tip of the middle shaft.
The tip portion of the middle shaft is embedded in the insulating powder through the inner peripheral side of the press-fit portion,
A diameter-reduced portion that is smaller than the outer diameter of the general portion of the metal tube is formed at the tip of the metal tube opposite to the side where the press-fit portion is provided,
Between the insertion side end portion of the heater and the press-fit portion, an insertion taper having a guide portion having an outer diameter smaller than the inner diameter of the fitting portion, and a taper surface connecting the guide portion and the press-fit portion. Are provided, and
A fitting taper portion is provided at the tip of the fitting portion of the housing, and the inclination angle of the fitting taper portion is larger than the inclination angle of the insertion taper portion in the heater with respect to the axial direction. There is a glow plug characterized by that.
[0025]
What should be noted in the glow plug of the present invention is that the heater is provided with the guide portion and the insertion taper portion.
Thereby, the glow plug of the present invention can be easily manufactured by the above-described excellent manufacturing method, and high dimensional accuracy and high quality characteristics can be obtained.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary Embodiment A glow plug and a manufacturing method thereof according to an exemplary embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the glow plug 1 of this example includes a housing 5 provided with an inner hole 50, a heater 10 press-fitted into the inner hole 50 of the housing 5, and a central shaft for energizing the heater 10. 4.
[0027]
Further, as shown in FIG. 1, the press-fitting and fixing between the housing 5 and the heater 10 is performed by press-fitting the fitting portion 55 provided in the inner hole 50 of the housing 5 and the press-fitting portion 15 provided on the outer periphery of the heater 10. Is going.
Between the insertion side end 112 of the heater 10 and the press-fit portion 15, a guide portion 17 having an outer diameter smaller than the inner diameter of the fitting portion 55 of the housing 5, the guide portion 17 and the press-fit portion 15 are provided. An insertion taper portion 16 having a tapered surface to be connected is provided.
[0028]
Further, as shown in FIG. 1, the heater 10 includes a metal tube 11 having a U-shaped cross-section with the tip 111 closed, and a heat coil 3 accommodated via an insulating powder 2 filled in the metal tube 11.
The center shaft 4 has a tip 41 embedded in the insulating powder 2 from an insertion side end (open end of the metal tube 11) 112 of the heater 10. Further, one end 31 of the heat coil 3 is welded to the inner surface of the tip of the metal tube 11, and the other end 32 is welded to the tip of the middle shaft 4. Others are the same as the conventional example.
[0029]
Next, a manufacturing method of the glow plug 1 will be described.
In this example, first, the metal tube 11 for the heater 10 is prepared, and the middle shaft 4 in which one end of the heat coil 3 is welded in advance is prepared. Next, the heat coil 3 is inserted into the metal tube 11 and the other end of the heat coil 3 and the inner surface of the tip 111 of the metal tube 11 are welded.
[0030]
Next, the metal tube 11 is filled with magnesia (MgO) powder as the insulating powder 2 so as to fill the ends of the heat coil 3 and the central shaft 4.
Next, swaging is performed from the outer peripheral surface of the metal tube 11 to compress and reduce the diameter of the metal tube 11. Thereby, the filling density of the insulating powder 2 in the metal tube 11 is improved, and the middle shaft 4 and the heater 10 are integrated.
[0031]
Next, a guide portion forming process is performed on the heater 10.
Specifically, as shown in FIG. 2, the metal tube 11 is ground or cut from the portion to be the press-fit portion 15 to the opening end 112 (dotted line portion), and the press-fit portion 15, the insertion taper portion 16, and the guide portion 17. Form. At this time, the position of the press-fit portion 15 is provided such that the distance from the tip 111 of the heater 10 is always a constant distance L (FIG. 2). And the length variation of the metal tube 11 accompanying the said swaging process is absorbed by the length fluctuation | variation of a guide part. In this example, the position of the press-fit portion 15 is adjusted to a fixed position by changing the length of the guide portion in a range of 3 mm or more.
[0032]
Next, as shown in FIG. 3, the housing 5 is prepared, and a press-fitting process for press-fitting and fixing the heater 10 to the housing 5 is performed.
As shown in FIG. 3, the housing 5 has an inner hole 50 penetrating in the axial direction, and also has a fitting portion 55 at a position slightly inside the heater insertion port 51. Further, a fitting taper portion 56 having an expanded taper surface is provided at the distal end portion of the fitting portion 55, that is, the end portion near the heater insertion port 51. The inclination angle β of the fitting taper portion 56 with respect to the axial direction is larger than the inclination angle α of the insertion taper portion 16 in the heater 10 as shown in FIG.
[0033]
In performing the press-fitting process, the housing 5 is placed on the housing holding jig 86 with the heater insertion port 51 facing upward as shown in FIG. Unlike the conventional one, the housing holding jig 86 does not restrain the housing 5 in the horizontal direction, is sufficiently larger than the outer diameter of the central shaft 4 on the same axis as the inner hole 50 of the housing 5 and larger than the outer diameter of the housing 5. Have a small through hole 860.
[0034]
Next, as shown in FIG. 5, the heater 10 is inserted into the inner hole of the housing 5 with the middle shaft 4 at the head and temporarily assembled. At this time, if the axes of the heater 10 and the housing 5 are misaligned, they are corrected when the guide portion 17 of the heater 10 is inserted into the fitting portion 55 of the housing 5. Further, even when the insertion taper portion 16 of the heater 10 and the fitting taper portion 56 of the housing 5 come into contact with each other, the misalignment between both axes is further corrected.
[0035]
Next, as shown in FIG. 6, when the temporary assembly of the heater 10 and the housing 5 is completed, the heater 10 is strongly pressed by the heater fixing jig 81, and the press-fitting portion 15 is pressed against the fitting portion 55 of the housing 5. Press fit. Thereby, as shown in the figure, the glow plug 1 in which the heater 10 and the housing 5 are firmly integrated is obtained.
As shown in FIG. 1, a nut 71, a resin bush 72, an O-ring 73 made of an insulating elastic material, and a resin washer 74 are disposed on the central shaft protruding side of the housing 5 as in the conventional case.
[0036]
The glow plug 1 obtained in this way is very stable in quality and can be manufactured with high efficiency as compared with the conventional glow plug.
That is, by performing the guide portion forming process on the heater 10 in advance as described above, the axial centers of the heater 10 and the housing 5 can be easily aligned by simply temporarily assembling the heater 10 and the housing 5. Therefore, the time required for the alignment of the shaft in the press-fitting process can be remarkably shortened compared to the conventional case, and the production of the glow plug can be made highly efficient.
[0037]
In addition, since the alignment of the shaft can be reliably performed, it is possible to prevent the occurrence of a glow plug in which the heater 10 and the housing 5 are misaligned. Moreover, the influence of the length dispersion | variation accompanying the swaging process in the manufacture process of the heater 10 can be avoided easily, and the press-fit which always made the protrusion length of the heater 10 constant can be performed stably and easily.
[0038]
The opening end (insertion end portion of the heater 10) 112 and the press-fit portion 15 of the metal tube 11 and the press-fit portion 15 are arranged at a certain distance due to the presence of the guide portion 17 and the insertion taper portion 16. Therefore, even when the press-fit portion 15 is reduced in diameter by press-fitting and fixing, the opening end 112 of the metal tube 11 is hardly reduced in diameter. Therefore, the insulation between the metal tube 11 and the middle shaft 4 can be maintained.
[0039]
Furthermore, in this example, the press-fit portion 15 is also cut. Therefore, the press-fit part has a high roundness. Further, as shown in FIG. 4, the inclination angle α of the insertion taper portion 16 of the heater 10 and the inclination angle β of the fitting taper portion 56 of the housing 5 are set in a relationship of α <β <45 °. Therefore, the press-fitting conditions during the press-fitting process are stable, so that a stable press-fitting portion can always be obtained.
[0040]
Needless to say, if the roundness or the like of the press-fit portion 15 can be obtained with sufficient accuracy after swaging, the press-fit portion can be cut. That is, as shown in FIG. 7, the heater 10 can have a two-stage shape, that is, the press-fit portion 15 can have the same outer diameter as the main body of the heater 10 and the guide portion 17 can have a smaller diameter. In this case, the same effect as described above can be obtained.
[Brief description of the drawings]
FIG. 1 is a partially cutaway sectional view of a glow plug according to an embodiment.
FIG. 2 is an explanatory view showing an integrated product of a heater and a central shaft in the embodiment.
FIG. 3 is an explanatory view showing a state in which the housing is placed on a housing holding jig in the embodiment.
FIG. 4 is an explanatory diagram showing the relationship between the inclination angles of the insertion taper portion of the heater and the fitting taper portion of the housing in the embodiment.
FIG. 5 is an explanatory diagram showing a temporarily assembled state of the heater and the housing in the embodiment.
FIG. 6 is an explanatory view showing when the heater and the housing are press-fitted and fixed in the embodiment.
FIG. 7 is an explanatory diagram showing another example of the heater shape in the embodiment.
FIG. 8 is a partially cutaway cross-sectional view of a glow plug according to a conventional example.
FIG. 9 is an explanatory view showing an integrated product of a heater and a central shaft in a conventional example.
FIG. 10 is an explanatory view showing when a heater and a housing are press-fitted and fixed in a conventional example.
[Explanation of symbols]
1. . . Glow plug,
10. . . heater,
11. . . Metal tube,
15. . . Press fitting,
16. . . Insertion taper,
17. . . Guide section,
2. . . Insulating powder,
3. . . Heat coil,
4). . . Middle shaft,
5). . . housing,
50. . . Inner hole,
55. . . Fitting portion,
56. . . Mating taper,

Claims (3)

内孔を設けたハウジングと，該ハウジングの上記内孔内に圧入固定したヒータと，該ヒータへの通電を行うための中軸とを有し，かつ，上記ハウジングと上記ヒータとの圧入固定は，上記ハウジングの内孔内に設けた嵌合部と上記ヒータの外周に設けた圧入部とを圧入嵌合させて行っており，
上記ヒータは，上記圧入部を設けた金属チューブと，該金属チューブ内に充填した絶縁粉末と，該絶縁粉末内に埋設したヒートコイルとを有しており，
該ヒートコイルは，その一端が上記金属チューブの先端内面に，その他端が上記中軸の先端にそれぞれ溶接してあり，
上記中軸の先端部分は，上記圧入部の内周側を通って上記絶縁粉末内に埋設してあり，
上記金属チューブにおいて上記圧入部を設けた側とは反対側の先端部には，当該金属チューブの一般部の外径よりも縮径した縮径部が形成してあるグロープラグを製造する方法において，
上記中軸と上記ヒータとを一体化させる一体化工程と，
上記ヒータの上記圧入部に切削を施し，上記嵌合部の内径よりも小さい外径を有するガイド部と，該ガイド部と上記圧入部とを結ぶテーパ面を有する挿入テーパ部を設けるガイド部形成工程と，
上記ハウジングの上記嵌合部の先端部に，上記ヒータにおける上記挿入テーパ部の軸方向に対する傾斜角度よりも大きい傾斜角度を有する嵌合テーパ部を設ける嵌合テーパ部形成工程と，
上記ガイド部を上記嵌合部内に挿入すると共に，上記挿入テーパ部を上記嵌合部と上記嵌合テーパ部との間の角部に当接させて，当該ヒータの軸芯と当該ハウジングの軸芯とを合わせた後，上記圧入部の表面を上記嵌合部と上記嵌合テーパ部との間の角部によって削って当該圧入部を当該嵌合部内に圧入することにより，当該ヒータを当該ハウジングに圧入固定する圧入工程とを含むことを特徴とするグロープラグの製造方法。A housing having an inner hole, a heater press-fitted and fixed in the inner hole of the housing, and a central shaft for energizing the heater, and press-fitting and fixing the housing and the heater are: The fitting portion provided in the inner hole of the housing and the press-fitting portion provided on the outer periphery of the heater are press-fitted and fitted,
The heater includes a metal tube provided with the press-fitting portion, an insulating powder filled in the metal tube, and a heat coil embedded in the insulating powder.
One end of the heat coil is welded to the inner surface of the tip of the metal tube, and the other end is welded to the tip of the middle shaft.
The tip portion of the middle shaft is embedded in the insulating powder through the inner peripheral side of the press-fit portion,
In the method of manufacturing a glow plug, wherein the metal tube has a reduced diameter portion formed at the tip opposite to the side where the press-fitting portion is provided, which is smaller than the outer diameter of the general portion of the metal tube. ,
An integration step of integrating the middle shaft and the heater;
Guide part formation in which the press-fitted part of the heater is cut and a guide part having an outer diameter smaller than the inner diameter of the fitting part and an insertion taper part having a tapered surface connecting the guide part and the press-fitted part are provided. Process,
A fitting taper forming step in which a fitting taper portion having an inclination angle larger than an inclination angle with respect to an axial direction of the insertion taper portion in the heater is provided at a distal end portion of the fitting portion of the housing;
The guide portion is inserted into the fitting portion, and the insertion taper portion is brought into contact with a corner portion between the fitting portion and the fitting taper portion so that the heater shaft and the housing shaft are inserted. after combination of the core, by press-fitting the press-fit portion by cutting the corner portion between said fitting portion of the surface of the press-fit portion and the fitting tapered portion in the fitting portion, the said heater method of manufacturing a glow plug which comprises a press-fitting step of press-fitted into the housing. 請求項１において，上記圧入工程においては，ハウジング保持具上に上記ハウジングを載置し，該ハウジングの上記内孔内に上記中軸と一体化させた上記ヒータを挿入するときに，上記ガイド部を上記嵌合部内に挿入して，当該ヒータの軸芯と当該ハウジングの軸芯とを合わせ，In the press-fitting step according to claim 1, when the housing is placed on a housing holder and the heater integrated with the middle shaft is inserted into the inner hole of the housing, the guide portion is inserted. Insert it into the fitting part and align the axis of the heater and the axis of the housing,
その後，ヒータ固定治具における有底内孔内に，上記ヒータにおける上記金属チューブの上記一般部の一部及び上記縮径部を挿入し，当該ヒータ固定治具により当該ヒータを押圧することにより，上記圧入部を上記嵌合部内に圧入することを特徴とするグロープラグの製造方法。  Thereafter, by inserting a part of the general portion of the metal tube and the reduced diameter portion in the bottomed inner hole of the heater fixing jig, and pressing the heater with the heater fixing jig, A method for manufacturing a glow plug, wherein the press-fitting part is press-fitted into the fitting part. 内孔を設けたハウジングと，該ハウジングの上記内孔内に圧入固定したヒータと，該ヒータへの通電を行うための中軸とを有し，かつ，上記ハウジングと上記ヒータとの圧入固定は，上記ハウジングの内孔内に設けた嵌合部と上記ヒータの外周に設けた圧入部とを圧入嵌合させて行っているグロープラグにおいて，A housing having an inner hole, a heater press-fitted and fixed in the inner hole of the housing, and a central shaft for energizing the heater, and press-fitting and fixing the housing and the heater are: In a glow plug in which a fitting portion provided in an inner hole of the housing and a press-fitting portion provided on an outer periphery of the heater are press-fitted and fitted,
上記ヒータは，上記圧入部を設けた金属チューブと，該金属チューブ内に充填した絶縁粉末と，該絶縁粉末内に埋設したヒートコイルとを有しており，上記圧入部は，切削により形成してあり，  The heater includes a metal tube provided with the press-fit portion, an insulating powder filled in the metal tube, and a heat coil embedded in the insulating powder. The press-fit portion is formed by cutting. And
上記ヒートコイルは，その一端が上記金属チューブの先端内面に，その他端が上記中軸の先端にそれぞれ溶接してあり，  One end of the heat coil is welded to the inner surface of the tip of the metal tube, and the other end is welded to the tip of the center shaft.
上記中軸の先端部分は，上記圧入部の内周側を通って上記絶縁粉末内に埋設してあり，  The tip portion of the middle shaft is embedded in the insulating powder through the inner peripheral side of the press-fit portion,
上記金属チューブにおいて上記圧入部を設けた側とは反対側の先端部には，当該金属チューブの一般部の外径よりも縮径した縮径部が形成してあり，  A diameter-reduced portion that is smaller than the outer diameter of the general portion of the metal tube is formed at the tip of the metal tube opposite to the side where the press-fit portion is provided,
上記ヒータの挿入側端部と上記圧入部との間には，上記嵌合部の内径よりも小さい外径を有するガイド部と，該ガイド部と上記圧入部とを結ぶテーパ面を有する挿入テーパ部とが設けてあり，  Between the insertion side end portion of the heater and the press-fit portion, an insertion taper having a guide portion having an outer diameter smaller than the inner diameter of the fitting portion, and a taper surface connecting the guide portion and the press-fit portion. Are provided, and
上記ハウジングの上記嵌合部の先端部には，嵌合テーパ部が設けてあり，該嵌合テーパ部の傾斜角度は，上記ヒータにおける挿入テーパ部の軸方向に対する傾斜角度よりも大き  A fitting taper portion is provided at the tip of the fitting portion of the housing, and the inclination angle of the fitting taper portion is larger than the inclination angle of the insertion taper portion in the heater with respect to the axial direction. くしてあることを特徴とするグロープラグ。Glow plug characterized by being combed.
JP27355397A 1997-09-19 1997-09-19 Glow plug and manufacturing method thereof Expired - Lifetime JP3885311B2 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP27355397A JP3885311B2 (en) 1997-09-19 1997-09-19 Glow plug and manufacturing method thereof
EP19980117773 EP0903541B1 (en) 1997-09-19 1998-09-18 Glow plug
EP04008758A EP1441179A3 (en) 1997-09-19 1998-09-18 Glow plug
DE69827571T DE69827571T2 (en) 1997-09-19 1998-09-18 glow plug

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP27355397A JP3885311B2 (en) 1997-09-19 1997-09-19 Glow plug and manufacturing method thereof

Publications (2)

Publication Number Publication Date
JPH1194253A JPH1194253A (en) 1999-04-09
JP3885311B2 true JP3885311B2 (en) 2007-02-21

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DE60225618T3 (en) 2001-04-27 2014-04-30 Ngk Spark Plug Co., Ltd. Heating, glow plug and water heater
EP1262716B1 (en) 2001-05-28 2008-08-06 Ngk Spark Plug Co., Ltd Heater and glow plug
DE10140183A1 (en) * 2001-08-22 2003-03-13 Beru Ag Wasservorwärmstutzen
JP2003336842A (en) * 2002-05-15 2003-11-28 Ngk Spark Plug Co Ltd Method of manufacturing for glow plug
JP4843430B2 (en) * 2006-09-12 2011-12-21 日本特殊陶業株式会社 Glow plug manufacturing method
US10337358B2 (en) 2015-09-17 2019-07-02 Hitachi Automotive Systems, Ltd. Valve timing control apparatus for internal combustion engine

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