JP4424836B2

JP4424836B2 - Air bag built-in pillar garnish and method for manufacturing the same

Info

Publication number: JP4424836B2
Application number: JP2000244863A
Authority: JP
Inventors: 健太郎岩永
Original assignee: Inoac Corp
Current assignee: Inoac Corp
Priority date: 2000-08-11
Filing date: 2000-08-11
Publication date: 2010-03-03
Anticipated expiration: 2020-08-11
Also published as: JP2002053002A

Description

【０００１】
【発明の属する技術分野】
この発明は、自動車のフロントピラー部に取り付けられるピラーガーニッシュに関し、特にはエアバッグを内蔵するピラーガーニッシュ及びその製造方法に関する。
【０００２】
【従来の技術】
近年、車両の側面衝突時にも乗員を保護するために、図１２および図１３に示すように、車体のピラー部９５に取り付けられるピラーガーニッシュ８０の裏側にもエアバッグＡが収容されるようになった。その場合、側面衝突によってエアバッグＡが膨張し、その膨張により、ピラーガーニッシュ８０が車室内側へ押し曲げられて車体ピラー部９５とピラーガーニッシュ８０間にエアバッグＡ通過用の隙間を形成し、その隙間を通ってエアバッグＡが乗員頭部ＴとウインドガラスＧ間に、鎖線Ｂｏのように展開し、乗員頭部Ｔを保護する。図中の符号Ｇはサイドガラス、Ｐはインストルメントパネルである。
【０００３】
ところで、前記エアバッグ内蔵式ピラーガーニッシュ８０にあっては、エアバッグＡ膨張時にピラーガーニッシュ８０が車体ピラー部９５から外れて飛散しないようにする必要がある。そのため、前記ピラーガーニッシュ８０の幅方向中間部をボルト等の棒状固定部材で車体ピラー部９５に確実に係止する構造が提案されている。
【０００４】
さらに、前記固定部材の頭部がピラーガーニッシュの意匠面、すなわち車室内側の表面に露出して美観を損なわないようにするため、図１２のＸ−Ｘ断面を示す図１４のように、射出成形時にピラーガーニッシュ８０の裏側に突出する固定部材用保持部８１を形成し、該固定部材用保持部８１に固定部材８５一端の頭部８６をインサート成形で埋設し固定することが考えられている。前記固定部材８５の軸部８７における他端には拡大した係止部８８が形成されている。図において、符号９１は車両のインナーパネル、９６はインナーパネル９１に形成された係止孔、Ｆはフロントガラス、Ｃはエンジンルームからの配線、１０１はオープニングトリム、１０２はグラスランチャンネル、１０３はボディフレームを示す。
【０００５】
しかしながら、図１４に示した構造を採用する場合には、固定部材用保持部８１の存在によってピラーガーニッシュ８０の厚みが局部的に変化するため、意匠面にヒケを生じ易くなる等の不具合がある。
【０００６】
【発明が解決しようとする課題】
この発明は前記の点に鑑みなされたもので、ピラーガーニッシュの外観にヒケの無い良好なもので、しかも簡単な構造で、かつエアバッグの膨張展開時にピラーガーニッシュの外れや破壊等を生じにくいエアバッグ内蔵式ピラーガーニッシュ及び、該ピラーガーニッシュを効率よく且つ精度良く射出成形できる製造方法を提供するものである。
【０００７】
【課題を解決するための手段】
すなわち請求項１の発明は、射出成形品からなるピラーガーニッシュの裏面に側壁を略筒状とする固定部材用保持部が突出形成され、該固定部材用保持部内に、軸部の途中から該軸部の一端の拡大した頭部までを被覆樹脂で覆った棒状固定部材が前記頭部を含む一端側で収容保持されて軸部途中の前記被覆樹脂で覆われた部位から他端側にかけて固定部材用保持部より突出したエアバッグ内蔵式ピラーガーニッシュにおいて、前記固定部材用保持部にはその先端に内向きの環状係止突部が形成され、前記被覆樹脂の側面外周には環状溝が形成され、該環状溝内の奥まで前記固定部材用保持部先端の環状係止突部内周縁が入り込んで係止すると共に、以下の（イ）、（ロ）の何れか又は両方の条件を満たしていることを特徴とするエアバッグ内蔵式ピラーガーニッシュに係る。
（イ）前記環状溝の溝幅ｔ１と、前記環状溝外側の固定部材用保持部外に位置する被覆樹脂の厚みｔ２との関係が、ｔ２＞ｔ１である。
（ロ）前記環状溝内最奥における被覆樹脂の厚みｔ３が１．５ｍｍ以上である。
【０００８】
また、請求項２の発明は、射出成形品からなるピラーガーニッシュの裏面に側壁を略筒状とする固定部材用保持部が突出形成され、該固定部材用保持部内に、軸部の途中から該軸部の一端の拡大した頭部までを被覆樹脂で覆った棒状固定部材が前記頭部を含む一端側で収容保持されて軸部途中の前記被覆樹脂で覆われている部位から他端側にかけて固定部材用保持部より突出したエアバッグ内蔵式ピラーガーニッシュにおいて、前記固定部材用保持部には側壁の内周に２つの環状係止突部が該側壁の長さ方向に離れて形成され、前記被覆樹脂の側面外周には前記環状係止突部と対応する位置に２つの環状溝が形成され、当該２つの環状溝内の奥までそれぞれ対応する前記環状係止突部が入り込んで係止すると共に、以下の（ニ）、（ホ）の何れか又は両方の条件を満たしていることを特徴とするエアバッグ内蔵式ピラーガーニッシュに係る。
（ニ）前記固定部材用保持部先端側に位置する環状溝内最奥における被覆樹脂の厚みｔ３ａが１．５ｍｍ以上である。
（ホ）前記固定部材用保持部先端側に位置する環状溝の溝幅ｔ１ａと、該固定部材用保持部先端からの被覆樹脂の突出寸法ｔ２ａの関係が、ｔ２ａ＞ｔ１ａである。
【０００９】
請求項３の発明は、型面に固定部材用保持部形成凹部と該固定部材用保持部形成凹部の内底面中央に形成された固定部材保持孔とを有するコア型と、前記コア型の型面との間で成形キャビティを構成する型面を有するキャビティ型とよりなる成形型を用い、被覆樹脂によって軸部の途中から該軸部の一端の拡大頭部までが覆われて当該軸部を覆う被覆樹脂側面外周に環状溝が形成された棒状固定部材を、前記拡大頭部とは反対の他端側から前記コア型の固定部材保持孔に挿入して被覆樹脂を固定部材用保持部形成凹部に配置し、該固定部材用保持部形成凹部の内壁側面と被覆樹脂側面間の隙間及び該被覆樹脂の環状溝により前記成形キャビティの固定部材用保持部形成空間を構成し、前記成形キャビティに溶融樹脂を射出することにより、ピラーガーニッシュの裏面に、側壁を略筒状とし該側壁先端に前記被覆樹脂側面の環状溝内の奥まで入り込んだ内向きの環状係止突部を有する固定部材用保持部が突出形成されたエアバッグ内蔵式ピラーガーニッシュを製造する方法において、以下（イ）、（ロ）、（ハ）の少なくとも１の条件を満たすことを特徴とするエアバッグ内蔵式ピラーガーニッシュの製造方法に係る。
（イ）前記環状溝の溝幅ｔ１と、前記環状溝外側の固定部材用保持部外に位置する被覆樹脂の厚みｔ２との関係が、ｔ２＞ｔ１である。
（ロ）前記環状溝内最奥における被覆樹脂の厚みｔ３が１．５ｍｍ以上である。
（ハ）前記コア型の固定部材保持孔の内径Ｗ１と、前記環状溝内最奥の被覆樹脂の径Ｗ２との関係が、Ｗ２≧Ｗ１である。
【００１０】
請求項４の発明は、型面に固定部材用保持部形成凹部と該固定部材用保持部形成凹部の内底面中央に形成された固定部材保持孔とを有するコア型と、前記コア型の型面との間で成形キャビティを構成する型面を有するキャビティ型とよりなる成形型を用い、被覆樹脂によって軸部の途中から該軸部の一端の拡大頭部までが覆われて当該軸部を覆う被覆樹脂側面外周に２つの環状溝が軸部の長さ方向に離れて形成された棒状固定部材を、前記拡大頭部とは反対の他端側から前記コア型の固定部材保持孔に挿入して被覆樹脂を固定部材用保持部形成凹部に配置し、該固定部材用保持部形成凹部の内壁側面と被覆樹脂側面間の隙間及び該被覆樹脂の２つの環状溝により前記成形キャビティの固定部材用保持部形成空間を構成し、前記成形キャビティに溶融樹脂を射出することにより、ピラーガーニッシュの裏面に、側壁を略筒状とし該側壁の内周面に前記被覆樹脂の２つの環状溝内の奥まで入り込んだ２つの環状係止突部を有する固定部材用保持部が突出形成されたエアバッグ内蔵式ピラーガーニッシュを製造する方法において、以下（ニ）、（ホ）、（ヘ）の少なくとも１の条件を満たすことを特徴とするエアバッグ内蔵式ピラーガーニッシュの製造方法に係る。
（ニ）前記固定部材用保持部先端側に位置する環状溝内最奥における被覆樹脂の厚みｔ３ａが１．５ｍｍ以上である。
（ホ）前記固定部材用保持部先端側に位置する環状溝の溝幅ｔ１ａと、該固定部材用保持部先端からの被覆樹脂の突出寸法ｔ２ａの関係が、ｔ２ａ＞ｔ１ａである。
（ヘ）前記コア型の固定部材保持孔の内径Ｗ１と、前記固定部材用保持部先端側に位置する環状溝内最奥の被覆樹脂の径Ｗ２ａとの関係が、Ｗ２ａ≧Ｗ１である。
【００１１】
【発明の実施の形態】
以下添付の図面に従ってこの発明を詳細に説明する。
図１はこの発明のエアバッグ内蔵式ピラーガーニッシュが取り付けられた車室内を示す概略図、図２は図１の２−２断面図、図３は図２の固定部材付近を示す拡大断面図、図４は図１の４−４断面図、図５は図１のピラーガーニッシュの製造時を示す成形型の部分断面図、図６は他の実施例に係るピラーガーニッシュの固定部材付近を示す図１の２−２と同位置における断面図、図７は図６の固定部材付近を示す拡大断面図、図８は図６のピラーガーニッシュの製造時を示す成形型の部分断面図、図９はインナーパネルの係止孔を示す斜視図、図１０は従来のピラーガーニッシュの製造時前半を示す成形型の部分断面図、図１１は同じくピラーガーニッシュの製造時後半を示す成形型の部分断面図である。
【００１２】
図１ないし図３に示すように、この発明におけるピラーガーニッシュ１０は、裏面側にエアバッグＡが折り畳まれた状態で自動車のインストルメントパネルＰ上方の車体ピラー部２０に取り付けられ、ピラー部２０の車室内側を覆う。そして自動車衝突時にはインストルメントパネルＰ付近に設置されているインフレータＩの作動によりガスがエアバッグＡ内に圧入され、インストルメントパネルＰ側（ピラーガーニッシュ１０下方側）から順次エアバッグＡが膨張して、ピラーガーニッシュ１０の車両後方側１１（すなわちサイドガラスＧ側）の側縁１２を車室内側へ押し曲げ、その押し曲げられたピラーガーニッシュ１０の側縁１２と車体ピラー部２０との隙間からエアバッグＡがサイドガラスＧ内側で展開して乗員の主として頭部を保護するようになっている。
【００１３】
前記ピラーガーニッシュ１０は、射出成形によって成形されたもので、車室内側へ膨らむ湾曲形状の横断面形状をした所要長さの樹脂製カバー体からなり、車両前後方向と対応する幅方向の略中央位置を境として車両後方側１１（サイドガラスＧ側）の裏面がエアバッグＡを収容する部分とされ、車両前方側１４（すなわちフロントガラスＦ側）の裏面がエンジンルームからの電源コードＣ等を収容する部分になっている。
【００１４】
前記ピラーガーニッシュ１０を構成する樹脂は適宜とされる。しかし、該ピラーガーニッシュ１０は、通常５０ｃｍ以上の長尺の部品とされるため、夏期の高い車室内温度等による熱膨張で寸法変化が生じ易く、しかも高温下では樹脂の軟化によってピラー部への取付部付近の強度が低下し易い性質がある。また、自動車の使用場所や季節を考慮すると、低温（−３５℃）から高温（９０℃）の範囲においてエアバッグ膨張時にピラーガーニッシュの破壊や飛散が生じにくいようにする必要があり、さらには、車体ピラー部への取付作業性の点から樹脂を適宜の硬さ（柔らかさ）とする必要がある。かかる点から、ピラーガーニッシュを構成する樹脂としては、アイゾッド衝撃強度（−３５℃、ＪＩＳＫ７１１０）が１９６Ｎ・ｍ／ｍ（２０ｋｇ・ｃｍ／ｃｍ）より大、曲げ弾性率（ＪＩＳＫ７２０３）が４．４１×１０³ＭＰａ（４，５００ｋｇ／ｃｍ²）より大、耐熱変形温度（０．４５ＭＰａ（４．６ｋｇ荷重）、ＪＩＳＫ７２０７）が９０℃より大、線膨張係数（−３５℃〜９０℃、ＡＳＴＭＤ６９６）が１０℃・ｃｍ／ｃｍより小のＴＰＯ（ポリオレフィン系熱可塑性エラストマー）が特に好ましい。
【００１５】
この例のピラーガーニッシュ１０は、下端がインストルメントパネルＰに形成された孔（図示せず）に挿入固定され、中間部がピラーガーニッシュ１０の長手方向に沿う４箇所の取付部位１５，１５，１６，１６で車体ピラー部２０に取り付けられる。この例の中間取付部位１５，１５，１６，１６は、エアバッグＡ膨張時のピラーガーニッシュ外れ防止用取付部位１５と、平常時のガタツキ防止用取付部位１６とよりなり、ピラーガーニッシュ１０の下方側から順に外れ防止用取付部位１５とガタツキ防止用取付部位１６が交互に位置する。
【００１６】
外れ防止用取付部位１５では、ピラーガーニッシュ１０の裏面に固定部材用保持部３０が突出形成され、その固定部材用保持部３０内に棒状固定部材４０の頭部４２側が収容保持されている。この固定部材用保持部３０は側壁３１を略筒状とするものであり、該側壁３１先端に内向きの環状係止突部３５が形成されている。この例の環状係止突部３５は、前記側壁３１先端から固定部材用保持部３０内へ略直角に突出し、中央部が固定部材４０との係合孔３４を構成している。なお、この固定部材用保持部３０における側壁３１の厚みＴ２は、固定部材用保持部３０外側のピラーガーニッシュの厚みＴ１との関係が、Ｔ１＞Ｔ２≧０が好ましい。このような厚み関係にすると、固定部材用保持部３０の側壁３１の剛性が小さくなって、ピラーガーニッシュ１０の車室内側への押し曲げの際に、ヒンジ部となる固定部材用保持部３０側壁３１の基部３２に応力集中が少なくなり、エアバッグＡの膨張展開時に固定部材用保持部３０側壁３１の基部３２で亀裂を生じ難くなる。
【００１７】
棒状固定部材４０は、軸部４３の一端を大径の頭部４２とし、該軸部４３の他端側に大径の係止部４４を設けた固定部材本体４１と、前記軸部４３の途中（軸部４３の両端間の適宜位置）から、該軸部４３の一端の拡大頭部４２までを覆った被覆樹脂４５とよりなる。
【００１８】
前記固定部材本体４１は、図示のものに限られるものではなく、ボルトとナットからなるものとし、ボルトの頭部が固定部材の頭部を構成し、ナットが係止部を構成するようにしたもの等適宜のものが用いられる。ボルトとナットで構成される場合は、前記係止部としてのナットはボルトに螺合され、頭部との間隔を所定距離として溶接などで位置がずれないように固着されたものとする。なお、前記頭部４２と係止部４４の間隔は、このピラーガーニッシュ１０を車体ピラー部２０に取り付ける際に取付け可能な寸法とされる。
【００１９】
前記被覆樹脂４５は、予め射出成形等によって固定部材本体４１の軸部４３途中から該軸部４３の一端の頭部４２までを覆うようにして形成される。この被覆樹脂４５で覆われた状態で固定部材４０は、前記ピラーガーニッシュ１０の射出成形の際に固定部材用保持部３０に収容保持される。前記被覆樹脂４５は固定部材本体４１の頭部４２より大径の円柱状からなり、該被覆樹脂４５の側面外周に、環状溝４６が形成され、該環状溝４６内の奥まで前記固定部材用保持部３０先端の環状係止突部３５内周縁３６が入り込んで係止する。前記環状溝４６の位置は、前記固定部材本体４１の頭部４２よりも軸部他端の係止部４４寄りが好ましい。
【００２０】
前記頭部４２表面４２ｓに位置する被覆樹脂４５の表面４５ｓは、前記固定部材用保持部３０の側壁３１で包囲されたピラーガーニッシュの部分１０ｓの表面形状と等しくなっていることが好ましい。それによって、前記固定部材用保持部３０の側壁３１で覆われたピラーガーニッシュ部分１０ｓにおけるピラーガーニッシュ１０の樹脂厚が均一になり、樹脂厚の不均一に起因するピラーガーニッシュ１０意匠面のヒケを防止できる。
【００２１】
また、前記固定部材４０は、後に詳述するように被覆樹脂４５で覆われた頭部４２を含む軸部４３の一端側がインサート射出成形によってピラーガーニッシュ１０の固定部材用保持部３０に収容保持される。そのインサート成形の際、図１０及び図１１に示すように、固定部材４０を射出成形型６０のコア型６１に形成されている固定部材保持孔６２に係止部４４側の他端側から挿入して固定部材用保持部形成凹部６３に被覆樹脂４５部分を配置し、該コア型６１とキャビティ型６５間の成形キャビティＣに溶融樹脂Ｐを射出し、該溶融樹脂Ｐをコア型６１の固定部材用保持部形成凹部の内壁側面６３ａと被覆樹脂４５間及び被覆樹脂４５の環状溝４６内とで構成される固定部材用保持部形成空間６４に充填することによって、前記筒状の側壁３１とその先端の環状係止突部３５とよりなる固定部材用保持部３０がピラーガーニッシュ１０の裏面に形成される。固定部材保持孔６２の内径はピラーガーニッシュ１０の脱型が可能なように、固定部材４０における係止部４４の径以上の寸法とされるため、固定部材４０の軸部４３と固定部材保持孔６２内周面間には空間Ｓが形成される。符号６９は突き出しピンである。
【００２２】
ところが、前記溶融樹脂Ｐが固定部材用保持部形成空間６４を満たす際に、図１１の（I）のように射出圧により、及び図１１の（II）のように射出完了後の型内保圧により、溶融樹脂Ｐが被覆樹脂４５の環状溝４６内奥を突き破ってコア型６１の固定部材保持孔６２内にまで侵入し、軸部４３周囲の空間Ｓを満たして硬化することが発生し易い。そのため、得られるピラーガーニッシュ１０は、前記環状溝４６が破壊された状態になり、前記固定部材４０の頭部４２保持不良を生じ易い。この不具合を防ぐには、コア型６１を分割式のものとし、前記被覆樹脂４５で覆われていない軸部４３の外周面と固定部材保持孔６２内周面間に空間Ｓを生じないようにすることが考えられるが、その場合には成形型のコストが上昇し、ピラーガーニッシュの作業性にも好ましくない。
【００２３】
そこで、前記不具合の発生を防ぐため、この発明においては、前記被覆樹脂４５を、以下の（イ）又は（ロ）のいずれか又は両方の条件を満たしているものとする。（イ）前記環状溝４６の溝幅ｔ１と、前記環状溝４６外側の固定部材用保持部３０外に位置する被覆樹脂４５の厚みｔ２との関係が、ｔ２＞ｔ１である。（ロ）前記環状溝４６内最奥における被覆樹脂４５の厚みｔ３が１．５ｍｍ以上である。このようにすることによって、前記被覆樹脂４５の環状溝４６部分における強度が向上して前記射出成形時の圧力に耐えられ、該環状溝４６が破壊されていない良好な固定部材用保持部３０が得られる。最も好ましいのは、前記（イ）、（ロ）の両方を満たす場合である。この例では、ｔ１：１．５ｍｍ、ｔ２：２．５ｍｍ、ｔ３：２．５ｍｍである。
【００２４】
前記被覆樹脂４５を構成する合成樹脂としては、例としてオレフィン系のエラストマーを挙げることができる。さらに好ましくは、被覆樹脂４５を構成する樹脂の曲げ弾性率（ＪＩＳＫ７２０３で測定）が７００ＭＰａ以上、熱変形温度（ＪＩＳＫ７２０７４５．０８Ｎ荷重（４．６ｋｇ荷重））が１００℃以上のエラストマーが挙げられる。このように樹脂を選択することによって、成形に際してピラーガーニッシュ本体１０（固定部材４０を除く部分）を成形する樹脂の熱及び圧力に耐える高剛性、高温耐熱の樹脂とすることができ、またピラーガーニッシュ１０本体の樹脂との融着強度が高くなる。
【００２５】
ガタツキ防止用固定部位１６には、図４に示すように、ピラーガーニッシュ１０裏面に形成されたクリップ用座部５３を有し、この座部５３に金属製または樹脂製のクリップ５１が固着され、車体ピラー部２０のインナーパネル２１に形成されたクリップ孔２９にクリップ５１が挿入されて係合するようになっている。この例のクリップ５１は、外側へ膨らむように屈曲した係止片５２，５２を有し、ピラーガーニッシュ１０の車体ピラー部２０への取り付けによって、ガタツキなくピラーガーニッシュ１０を車体ピラー部２０に固定し、エアバッグＡの膨張によるピラーガーニッシュ１０の押し曲げ時に、クリップ５１がインナーパネル２１のクリップ孔２９から外れるようになっている。また、このクリップ用座部５３は、薄肉のリブ状からなり、ピラーガーニッシュ１０の意匠面にヒケを生じないようになっている。
【００２６】
次に、前記ピラーガーニッシュ１０の製造方法の実施例について、射出成形型６０の一部を示す図５を用いて説明する。この発明のエアバッグ内蔵式ピラーガーニッシュ１０は、射出成形型６０を用いる公知のインサート射出成形を利用して行われる。射出成形型６０は、型面所定部に固定部材用保持部形成凹部６３と該固定部材用保持部形成凹部の内底面中央に形成された固定部材保持孔６２とを有するコア型６１と、前記コア型６１の型面との間で成形キャビティＣを構成する型面を有するキャビティ型６５とよりなる。固定部材用保持部形成凹部６３の寸法は、深さが前記固定部材４０の被覆樹脂４５の軸長方向の厚みと等しくされ、内径については固定部材４０の頭部４２とは反対側の被覆樹脂４５端部の径と等しくされている。また、前記固定部材保持孔６２は被覆樹脂４５を支持できるように被覆樹脂４５の径より小さくされ、さらに固定部材４０の係止部４４まで完全に収容できる深さとされる。なお、前記コア型６１の型面にはその他、前記ガタツキ防止用座部のための凹部等、必要な凹凸形状が成形されて前記成形キャビティＣがピラーガーニッシュ形状とされている。符号６９は製品突き出しピンである。
【００２７】
そして、前記被覆樹脂４５側面外周に環状溝４６が形成された棒状固定部材４０を、前記拡大頭部４２とは反対の他端側から前記コア型６１の固定部材保持孔６２に挿入して被覆樹脂４５を固定部材用保持部形成凹部６３に配置し、該固定部材用保持部形成凹部６３の内壁側面６３ａと被覆樹脂４５側面間の隙間及び該被覆樹脂４５の環状溝４６により前記成形キャビティＣの固定部材用保持部形成空間６４を構成する。次いで、この成形キャビティＣに溶融樹脂Ｐを射出することにより、ピラーガーニッシュ１０の裏面に、側壁３１を略筒状とし該側壁３１先端に前記被覆樹脂４５側面の環状溝４６内の奥まで入り込んだ内向きの環状係止突部３５を有する固定部材用保持部３０が突出形成される。
【００２８】
前記製造においては、図４に示した不具合を生じないようにするため、すなわち前記溶融樹脂Ｐが被覆樹脂４５の環状溝４６を破壊しないようにするため、以下（イ）、（ロ）、（ハ）の少なくとも１の条件を満たすことが好ましい。
（イ）前記環状溝４６の溝幅ｔ１と、前記環状溝４６外側の固定部材用保持部外に位置する被覆樹脂４５の厚みｔ２との関係が、ｔ２＞ｔ１である。
（ロ）前記環状溝４６内最奥における被覆樹脂４５の厚みｔ３が１．５ｍｍ以上である。
（ハ）前記コア型６１の固定部材保持孔６２の内径Ｗ１と、前記環状溝４６内最奥の被覆樹脂４５の径Ｗ２との関係が、Ｗ２≧Ｗ１である。
この（イ），（ロ）に関しては、先に述べたように被覆樹脂４５の強度向上を図る条件であり、（ハ）は射出成形時に環状溝４６外の被覆樹脂４５先端面を固定部材保持孔６２周縁の固定部材用保持部形成凹部６３で支持し、環状溝４６内に充填された溶融樹脂Ｐが被覆樹脂４５を破壊しないようにするものである。最も好ましいのは（イ）、（ロ）、（ハ）の全ての条件を満たす場合である。
射出終了後成形型６０を開き、前記突き出しピン６９により成形品を押し出せば、図１ないし４に示したピラーガーニッシュ１０が得られる。
【００２９】
この発明のピラーガーニッシュにおける外れ防止用取付部位１５の構造としては、前記したものだけでなく、図６及び７に示すピラーガーニッシュ１０Ａのように、固定部材用保持部３０Ａの側壁３１Ａの内周に固定部材４０Ａの軸方向に離れた２つの環状係止突部３５Ａ，３５Ａが形成され、棒状固定部材４０Ａの被覆樹脂４５Ａの側面外周には前記２つの環状係止突部３５Ａ，３５Ａと対応する位置に２つの環状溝４６Ａ，４６Ａが形成され、当該２つの環状溝４６Ａ，４６Ａ内の奥までそれぞれ対応する前記環状係止突部３５Ａ，３５Ａが入り込んで係止するとともに、以下の（ニ）、（ホ）のいずれか又は両方の条件を満たしている構造も好ましい。なお、前記ガタツキ防止用取付部位１６については、前記実施例のピラーガーニッシュ１０と同様である。図において、同一部材は同一符号で表す。
（ニ）前記固定部材用保持部３０Ａ先端側に位置する環状溝４６Ａ内最奥における被覆樹脂４５Ａの厚みｔ３ａが１．５ｍｍ以上である。
（ホ）前記固定部材用保持部３０Ａ先端側に位置する環状溝４６Ａの溝幅ｔ１ａと、該固定部材用保持部３０Ａ先端からの被覆樹脂４５Ａの突出寸法ｔ２ａの関係が、ｔ２ａ＞ｔ１ａである。
この条件は前記実施例のピラーガーニッシュ１０と同様に、射出成形の際の被覆樹脂４５Ａの強度を高め、図４の不具合を防止するものである。勿論、最も好ましいのは（ニ）、（ホ）の両方を満たす場合である。
【００３０】
この実施例のピラーガーニッシュ１０Ａに対する製造方法としては、前記ピラーガーニッシュ１０の製造と同様の成形キャビティＣを有する射出成形型６０を用い、前記被覆樹脂４５Ａ側面外周に２つの環状溝４６Ａ，４６Ａが形成された棒状固定部材４０Ａを、前記拡大頭部４２とは反対の他端側から前記コア型６１の固定部材保持孔６２に挿入して被覆樹脂４５Ａを固定部材用保持部形成凹部６３に配置し、該固定部材用保持部形成凹部６３の内壁側面６３ａと被覆樹脂４５Ａ側面間の隙間及び該被覆樹脂４５Ａの２つの環状溝４６Ａ，４６Ａにより前記成形キャビティの固定部材用保持部形成空間６４Ａを構成する。そして、前記成形キャビティＣに溶融樹脂Ｐを射出することにより、ピラーガーニッシュ１０Ａの裏面に、側壁３１Ａを略筒状とし該側壁３１Ａの内周面に前記被覆樹脂４５Ａの２つの環状溝４６Ａ，４６Ａ内の奥まで入り込んだ２つの環状係止突部３５Ａ，３５Ａを有する固定部材用保持部３０Ａが突出形成されたエアバッグ内蔵式ピラーガーニッシュ１０Ａが得られる。
【００３１】
また、前記製造方法において、以下（ニ）、（ホ）、（ヘ）の少なくとも１の条件を満たすことが好ましい。
（ニ）前記固定部材用保持部３０Ａ先端側に位置する環状溝４６Ａ内最奥における被覆樹脂４５Ａの厚みｔ３ａが１．５ｍｍ以上である。
（ホ）前記固定部材用保持部３０Ａ先端側に位置する環状溝４６Ａの溝幅ｔ１ａと、該固定部材用保持部３０Ａ先端からの被覆樹脂４５Ａの突出寸法ｔ２ａの関係が、ｔ２ａ＞ｔ１ａである。
（ヘ）前記コア型６１の固定部材保持孔６２の内径Ｗ１と、前記固定部材用保持部３０Ａ先端側に位置する環状溝４６Ａ内最奥の被覆樹脂４５Ａの径Ｗ２ａとの関係が、Ｗ２ａ≧Ｗ１である。
これらの条件は（ニ）、（ホ）は成形時における樹脂圧に耐えうるように被覆樹脂４５Ａを強化し、（へ）は環状溝４６Ａ，４６Ａ周辺における被覆樹脂４５Ａをコア型６１の固定部材用保持部形成凹部６３で支持し、溶融樹脂Ｐが被覆樹脂４５Ａを破壊するのを防止するものであり、最も好ましいのは、（ニ）、（ホ）、（ヘ）の全てを満たす場合である。
【００３２】
このようにしてなる前記ピラーガーニッシュ１０（１０Ａ）が取り付けられる車体ピラー部２０は、図４に示すようにインナーパネル２１に前記クリップ孔２９と、図９に示したような係止孔２５がピラーガーニッシュ１０の固定部材用固定部材用保持部３０（３０Ａ）の位置に対応して形成されている。この係止孔２５は、ピラーガーニッシュ１０（１０Ａ）の長手方向に沿う所定長の長孔からなり、前記固定部材４０（４０Ａ）の係止部４４が挿通可能な大径の孔２６を下端に有し、その上方に係止部４４の径より小さく、かつ軸部４３（４３Ａ）が挿通可能な大きさの軸部挿通路２７が伸びている。そして、ピラーガーニッシュ１０の取付時、まず、前記係止孔２５の大径の孔２６に前記固定部材４０（４０Ａ）の係止部４４を挿通し、前記軸部挿通路２７の上端２８に軸部４３（４３Ａ）が衝突するまで、ピラーガーニッシュ１０を車体ピラー部２０に沿って上方へスライドさせる。これによって、前記クリップ５１がインナーパネル２１のクリップ孔２９上に移動する。次いで、その位置でピラーガーニッシュ１０をインナーパネル２１側へ強く押してクリップ５１をクリップ孔２９に挿入係合させれば、ピラーガーニッシュ１０（１０Ａ）の取り付けが完了する。
【００３３】
前記車体ピラー部２０に取り付けられたピラーガーニッシュ１０（１０Ａ）は、エアバッグＡの膨張によりピラーガーニッシュ１０が車室内側へ押し曲げられる際に、前記固定部材４０（４０Ａ）の係止部４４がインナーパネル２１の係止孔２５の軸部挿通路２７に係合する（軸部挿通路２７の裏面に当たる）ことによって、車体ピラー部２０から外れることが防がれる。なお、前記固定部材４０（４０Ａ）の被覆樹脂４５（４５Ａ）で覆われていない軸部４３部分には、適宜ガタツキ防止用のクリップ等が適宜設けられてもよい。
【００３４】
【発明の効果】
以上図示し説明したように、請求項１の発明のエアバッグ内蔵式ピラーガーニッシュによれば、予め頭部を合成樹脂の被覆樹脂で覆った固定部材を、インサート射出成形時にピラーガーニッシュ裏面に一体に突出成形された固定部材用保持部に収容保持し、かつ固定部材用保持部には環状係止突部を設け、被覆樹脂には環状溝が形成されて該環状溝の奥まで固定部材用保持部先端の環状係止突部周縁が入り込んで係止する構造としたものであるため、意匠面にヒケの無い外観良好なものとなり、しかもエアバッグ膨出時におけるピラーガーニッシュの外れを確実に防止することができる。さらに、前記（イ）、（ロ）の条件の少なくとも一方を満たすことによって成形不良品を極めて少なくすることができ、かつ精度高いピラーガーニッシュが得られる。
【００３５】
さらに、請求項２のピラーガーニッシュによれば、予め頭部を合成樹脂の被覆樹脂で覆った固定部材を、インサート射出成形時にピラーガーニッシュ裏面に一体に突出成形された固定部材用保持部に収容固定し、かつ固定部材用保持部には２つの環状係止突部を設け、被覆樹脂には対応する位置に２つの環状溝が形成されて該環状溝の奥まで固定部材用保持部先端の環状係止突部周縁が入り込んで係止する構造としたものであるため、前記同様、エアバッグ膨出時におけるピラーガーニッシュの外れを確実に防止することができると共に、ヒケの発生も防ぐことができるので外観が良好になる。さらに、前記（ニ）、（ホ）の条件の少なくとも一方を満たすことによって成形不良品を極めて少なくすることができ、かつ精度高いピラーガーニッシュが得られる。
【００３６】
さらに、請求項３の発明における製造方法によれば、前記（イ）、（ロ）、（ハ）の条件の少なくとも１を満たすことにより、また請求項４の発明における製造方法によれば、前記（ニ）、（ホ）、（ヘ）の条件の少なくとも１を満たすことにより、エアバッグ膨出時に外れを生じ難く、しかも外観の良好なピラーガーニッシュを、成形不良少なく、かつ精度高く製造することができる。
【図面の簡単な説明】
【図１】この発明のエアバッグ内蔵式ピラーガーニッシュが取り付けられた車室内を示す概略図である。
【図２】図１の２−２断面図である。
【図３】図２の固定部材付近を示す拡大断面図である。
【図４】図１の４−４断面図である。
【図５】図１のピラーガーニッシュの製造時を示す成形型の部分断面図である。
【図６】他の実施例に係るピラーガーニッシュの固定部材付近を示す図１の２−２と同位置における断面図である。
【図７】図６の固定部材付近を示す拡大断面図である。
【図８】図６のピラーガーニッシュの製造時を示す成形型の部分断面図である。
【図９】インナーパネルの係止孔を示す斜視図である。
【図１０】従来のピラーガーニッシュの製造時前半を示す成形型の部分断面図である。
【図１１】同じくピラーガーニッシュの製造時後半を示す成形型の部分断面図である。
【図１２】従来のエアバッグ内蔵式ピラーガーニッシュが取り付けられた車室内の概略図である。
【図１３】エアバッグの膨張時を示す概略図である。
【図１４】図１２のＸ−Ｘ断面図である。
【符号の説明】
１０ピラーガーニッシュ
２０車体ピラー部
２５係止孔
３０固定部材用保持部
３５環状係止突部
４０固定部材
４２固定部材頭部
４３固定部材軸部
４４固定部材係止部
４５被覆樹脂
４６環状溝
６０成形型
６１コア型
６２固定部材保持孔
６３固定部材用保持部形成凹部
６５キャビティ型
Ｐ溶融樹脂
Ａエアバッグ
ｔ１環状溝の溝幅
ｔ２環状溝外側の固定部材用保持部外に位置する被覆樹脂の厚み
ｔ３環状溝内最奥における被覆樹脂の厚み
Ｗ１コア型の固定部材保持孔の内径
Ｗ２環状溝内最奥の被覆樹脂の径[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pillar garnish that is attached to a front pillar portion of an automobile, and more particularly, to a pillar garnish that incorporates an airbag and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, in order to protect an occupant even in the case of a side collision of a vehicle, as shown in FIGS. 12 and 13, the airbag A is also housed on the back side of the pillar garnish 80 attached to the pillar portion 95 of the vehicle body. It was. In that case, the airbag A is inflated due to a side collision, and the inflation causes the pillar garnish 80 to be pushed and bent toward the vehicle interior to form a gap for passing the airbag A between the vehicle body pillar portion 95 and the pillar garnish 80. Through the gap, the airbag A is deployed between the occupant head T and the wind glass G as indicated by a chain line Bo to protect the occupant head T. The code | symbol G in a figure is a side glass, P is an instrument panel.
[0003]
By the way, in the air bag built-in type pillar garnish 80, it is necessary to prevent the pillar garnish 80 from coming off the vehicle body pillar portion 95 when the airbag A is inflated. Therefore, a structure has been proposed in which the intermediate portion in the width direction of the pillar garnish 80 is securely locked to the vehicle body pillar portion 95 with a rod-like fixing member such as a bolt.
[0004]
Further, in order to prevent the head of the fixing member from being exposed to the design surface of the pillar garnish, that is, the surface on the vehicle interior side, so as not to impair the aesthetic appearance, as shown in FIG. 14 showing the XX cross section of FIG. It is considered that a fixing member holding portion 81 protruding to the back side of the pillar garnish 80 is formed at the time of molding, and a head 86 at one end of the fixing member 85 is embedded and fixed to the fixing member holding portion 81 by insert molding. . An enlarged locking portion 88 is formed at the other end of the shaft portion 87 of the fixing member 85. In the figure, reference numeral 91 denotes a vehicle inner panel, 96 denotes a locking hole formed in the inner panel 91, F denotes a windshield, C denotes wiring from the engine room, 101 denotes an opening trim, 102 denotes a glass run channel, and 103 denotes a body. Indicates a frame.
[0005]
However, when the structure shown in FIG. 14 is adopted, the thickness of the pillar garnish 80 is locally changed due to the presence of the fixing member holding portion 81, so that there is a problem such that the design surface is likely to be sinked. .
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and has a good appearance with no sink marks in the appearance of the pillar garnish, and has a simple structure, and air that hardly causes the pillar garnish to come off or break when the airbag is inflated and deployed. The present invention provides a bag built-in type pillar garnish and a production method capable of efficiently and accurately injection-molding the pillar garnish.
[0007]
[Means for Solving the Problems]
That is, in the first aspect of the present invention, a fixing member holding portion having a substantially cylindrical side wall protrudes from the back surface of a pillar garnish made of an injection molded product, and a shaft portion is formed in the fixing member holding portion. of The shaft part from the middle of A rod-shaped fixing member that is covered with a coating resin up to the enlarged head at one end is accommodated and held on one end side including the head, and is held for the fixing member from the portion covered with the coating resin in the middle of the shaft portion to the other end side. In the airbag built-in type pillar garnish protruding from the portion, the fixing member holding portion is formed with an inward annular locking protrusion at the tip thereof, and an annular groove is formed in the outer periphery of the side surface of the coating resin, The inner peripheral edge of the annular locking projection at the distal end of the holding part for the fixing member enters and locks to the back of the annular groove and satisfies either or both of the following conditions (A) and (B) The air bag built-in type pillar garnish is characterized.
(A) The relationship between the groove width t1 of the annular groove and the thickness t2 of the coating resin located outside the holding member holding portion outside the annular groove is t2> t1.
(B) The thickness t3 of the coating resin at the innermost end in the annular groove is 1.5 mm or more.
[0008]
Further, in the invention of claim 2, a fixing member holding portion having a substantially cylindrical side wall is formed on the back surface of a pillar garnish made of an injection-molded product, and a shaft portion is formed in the fixing member holding portion. of The shaft part from the middle of For a fixing member, a rod-shaped fixing member that covers up to the enlarged head at one end with a coating resin is accommodated and held at one end including the head and covered with the coating resin in the middle of the shaft portion to the other end. In the air bag built-in type pillar garnish protruding from the holding portion, the fixing member holding portion is formed with two annular locking protrusions on the inner periphery of the side wall apart from each other in the length direction of the side wall. On the outer periphery of the side surface, two annular grooves are formed at positions corresponding to the annular locking protrusions, and the corresponding annular locking protrusions enter and lock to the back of the two annular grooves, respectively. (D), (e), or both of the conditions are satisfied.
(D) The thickness t3a of the coating resin at the innermost end of the annular groove located on the distal end side of the holding part for the fixing member is 1.5 mm or more.
(E) The relationship between the groove width t1a of the annular groove located on the front end side of the fixing member holding portion and the protruding dimension t2a of the coating resin from the front end of the fixing member holding portion is t2a> t1a.
[0009]
According to a third aspect of the present invention, there is provided a fixing member holding portion forming concave portion on the mold surface, and the Holding part formation for fixed member Recess of Using a molding die comprising a core die having a fixing member holding hole formed in the center of the inner bottom surface and a cavity die having a die surface that forms a molding cavity between the core die surface and the coating resin From the middle of the shaft part of Hold the core-type fixing member from the other end opposite to the enlarged head from the other end side opposite to the enlarged head. The molding resin is inserted into the hole and disposed in the holding member forming recess for the fixing member, and the molding cavity is fixed by the gap between the inner wall side surface and the coating resin side surface of the fixing member holding portion forming recess and the annular groove of the coating resin. A member holding portion forming space is formed, and by injecting molten resin into the molding cavity, the side wall of the pillar garnish is formed into a substantially cylindrical shape, and the front end of the side wall enters into the inside of the annular groove on the side surface of the coating resin. In the method of manufacturing the airbag built-in type pillar garnish in which the fixing member holding portion having the inward annular locking projection protrudes, at least one of the following conditions (a), (b), and (c) Meet According to the method of manufacturing an airbag built-pillar garnish, characterized in that.
(A) The relationship between the groove width t1 of the annular groove and the thickness t2 of the coating resin located outside the holding member holding portion outside the annular groove is t2> t1.
(B) The thickness t3 of the coating resin at the innermost end in the annular groove is 1.5 mm or more.
(C) The relationship between the inner diameter W1 of the core-type fixing member holding hole and the diameter W2 of the innermost coating resin in the annular groove is W2 ≧ W1.
[0010]
According to a fourth aspect of the present invention, there is provided a fixing member holding portion forming concave portion on the mold surface and the fixing member forming concave portion. Holding part formation for fixed member Recess of Using a molding die comprising a core die having a fixing member holding hole formed in the center of the inner bottom surface and a cavity die having a die surface that forms a molding cavity between the core die surface and the coating resin From the middle of the shaft part of A rod-shaped fixing member in which two annular grooves are formed on the outer periphery of the side surface of the covering resin covering the shaft portion so as to cover the shaft portion at one end is opposite to the expansion head. Inserting into the core-type fixing member holding hole from the other end side and disposing the coating resin in the fixing member holding portion forming recess, the gap between the inner wall side surface and the coating resin side surface of the fixing member holding portion forming recess, A holding member forming space for the fixing member of the molding cavity is formed by the two annular grooves of the coating resin, and the molten resin is injected into the molding cavity, so that the side wall is substantially cylindrical on the back surface of the pillar garnish. In a method of manufacturing an airbag built-in type pillar garnish in which a fixing member holding portion having two annular locking protrusions that protrude into the inner peripheral surface of the coating resin as far as inside the two annular grooves protrudes, (D), ( ), According to the method of manufacturing an airbag built-pillar garnish, wherein the at least one condition is satisfied in (f).
(D) The thickness t3a of the coating resin at the innermost end of the annular groove located on the distal end side of the holding part for the fixing member is 1.5 mm or more.
(E) The relationship between the groove width t1a of the annular groove located on the front end side of the fixing member holding portion and the protruding dimension t2a of the coating resin from the front end of the fixing member holding portion is t2a> t1a.
(F) The relationship between the inner diameter W1 of the core-type fixing member holding hole and the diameter W2a of the innermost coating resin in the annular groove located on the distal end side of the fixing member holding portion is W2a ≧ W1.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view showing a passenger compartment in which an airbag built-in type pillar garnish of the present invention is attached, FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1, and FIG. 3 is an enlarged sectional view showing the vicinity of the fixing member in FIG. 4 is a cross-sectional view taken along the line 4-4 in FIG. 1, FIG. 5 is a partial cross-sectional view of the molding die when the pillar garnish of FIG. 1 is manufactured, and FIG. 6 is a view showing the vicinity of the fixing member of the pillar garnish according to another embodiment. 7 is a cross-sectional view at the same position as 2-2 in FIG. 1, FIG. 7 is an enlarged cross-sectional view showing the vicinity of the fixing member in FIG. 6, FIG. 8 is a partial cross-sectional view of the mold when the pillar garnish in FIG. FIG. 10 is a partial cross-sectional view of a mold that shows the first half of a conventional pillar garnish when it is manufactured, and FIG. 11 is a partial cross-sectional view of the mold that also shows the second half of a pillar garnish when it is manufactured. is there.
[0012]
As shown in FIGS. 1 to 3, the pillar garnish 10 according to the present invention is attached to a vehicle body pillar portion 20 above an instrument panel P of an automobile with the airbag A folded on the back surface side. Cover the passenger compartment. In the event of an automobile collision, gas is pressed into the airbag A by the operation of the inflator I installed near the instrument panel P, and the airbag A is inflated sequentially from the instrument panel P side (below the pillar garnish 10). The side edge 12 of the pillar garnish 10 on the vehicle rear side 11 (that is, the side glass G side) is pushed and bent toward the vehicle interior side, and the airbag is formed from the gap between the side edge 12 of the pushed pillar garnish 10 and the vehicle body pillar portion 20. A is developed inside the side glass G so as to mainly protect the head of the occupant.
[0013]
The pillar garnish 10 is formed by injection molding, and is formed of a resin cover body having a required length having a curved cross-sectional shape that swells toward the vehicle interior side, and is substantially in the center in the width direction corresponding to the vehicle longitudinal direction. The back side of the vehicle rear side 11 (side glass G side) is a part that accommodates the airbag A with the position as a boundary, and the back side of the vehicle front side 14 (that is, the windshield F side) accommodates the power cord C from the engine room. It is a part to do.
[0014]
The resin constituting the pillar garnish 10 is appropriate. However, since the pillar garnish 10 is usually a long part of 50 cm or more, a dimensional change is likely to occur due to thermal expansion due to a high vehicle interior temperature in summer, and the resin is softened at high temperatures to the pillar part. There exists a property which the intensity | strength of the attachment part vicinity falls easily. In consideration of the place of use of the car and the season, it is necessary to prevent the destruction and scattering of the pillar garnish when the airbag is inflated in the range of low temperature (−35 ° C.) to high temperature (90 ° C.). The resin needs to have an appropriate hardness (softness) from the viewpoint of workability in mounting to the vehicle body pillar portion. From this point, as a resin constituting the pillar garnish, the Izod impact strength (−35 ° C., JIS K 7110) is larger than 196 N · m / m (20 kg · cm / cm), and the flexural modulus (JIS K 7203) is 4. .41 × 10 ^Three MPa (4,500 kg / cm ² ), Heat resistant deformation temperature (0.45 MPa (4.6 kg load), JIS K 7207) is greater than 90 ° C., linear expansion coefficient (−35 ° C. to 90 ° C., ASTM D 696) is 10 ° C./cm/cm Smaller TPO (polyolefin thermoplastic elastomer) is particularly preferred.
[0015]
The pillar garnish 10 of this example is inserted and fixed at a lower end into a hole (not shown) formed in the instrument panel P, and an intermediate portion is provided at four attachment sites 15, 15, 16 along the longitudinal direction of the pillar garnish 10. , 16 are attached to the body pillar 20. The intermediate attachment portions 15, 15, 16, and 16 in this example include a pillar garnish removal prevention attachment portion 15 when the airbag A is inflated and a normal rattling prevention attachment portion 16, and the lower side of the pillar garnish 10. The mounting portions 15 for preventing disengagement and the mounting portions 16 for preventing backlash are alternately positioned in order.
[0016]
In the detachment preventing attachment portion 15, a fixing member holding portion 30 is formed to protrude from the back surface of the pillar garnish 10, and the head 42 side of the rod-like fixing member 40 is accommodated and held in the fixing member holding portion 30. The fixing member holding portion 30 has a side wall 31 having a substantially cylindrical shape, and an inward annular locking projection 35 is formed at the tip of the side wall 31. The annular locking projection 35 in this example protrudes from the front end of the side wall 31 into the fixing member holding portion 30 at a substantially right angle, and the center portion forms an engagement hole 34 with the fixing member 40. The thickness T2 of the side wall 31 in the fixing member holding portion 30 is preferably T1> T2 ≧ 0 in relation to the thickness T1 of the pillar garnish outside the fixing member holding portion 30. With such a thickness relationship, the rigidity of the side wall 31 of the fixing member holding portion 30 becomes small, and the side wall of the fixing member holding portion 30 that becomes a hinge portion when the pillar garnish 10 is pushed and bent toward the vehicle interior side. The stress concentration in the base portion 32 of the 31 is reduced, so that the base portion 32 of the side wall 31 of the fixing member holding portion 30 is hardly cracked when the airbag A is inflated and deployed.
[0017]
The rod-shaped fixing member 40 includes a fixing member body 41 having one end of the shaft portion 43 as a large-diameter head portion 42 and a large-diameter engaging portion 44 provided on the other end side of the shaft portion 43, and the shaft portion 43. From the middle (appropriate position between both ends of the shaft 43), the shaft 43 of The coating resin 45 covers up to the enlarged head 42 at one end.
[0018]
The fixing member main body 41 is not limited to the one shown in the figure, and is composed of a bolt and a nut, the head of the bolt constituting the head of the fixing member, and the nut constituting the locking portion. Appropriate ones such as those are used. When configured with a bolt and a nut, the nut as the locking portion is screwed into the bolt, and is fixed so as not to be displaced by welding or the like with a predetermined distance from the head. The distance between the head 42 and the locking portion 44 is a dimension that can be attached when the pillar garnish 10 is attached to the vehicle body pillar portion 20.
[0019]
The coating resin 45 is preliminarily formed from the middle of the shaft portion 43 of the fixing member main body 41 by injection molding or the like. of It is formed so as to cover up to the head 42 at one end. When the pillar garnish 10 is injection-molded, the fixing member 40 is accommodated and held in the fixing member holding portion 30 while being covered with the coating resin 45. The covering resin 45 has a columnar shape with a diameter larger than that of the head portion 42 of the fixing member main body 41, and an annular groove 46 is formed on the outer periphery of the side surface of the covering resin 45. The inner peripheral edge 36 of the annular locking projection 35 at the tip of the holding unit 30 enters and locks. The position of the annular groove 46 is preferably closer to the locking portion 44 at the other end of the shaft portion than the head portion 42 of the fixing member main body 41.
[0020]
The surface 45s of the coating resin 45 located on the surface 42s of the head 42 is preferably equal to the surface shape of the pillar garnish portion 10s surrounded by the side wall 31 of the fixing member holding portion 30. As a result, the resin thickness of the pillar garnish 10 in the pillar garnish portion 10s covered with the side wall 31 of the fixing member holding portion 30 becomes uniform, and the design surface of the pillar garnish 10 caused by unevenness of the resin thickness is prevented. it can.
[0021]
The fixing member 40 is housed and held in the fixing member holding portion 30 of the pillar garnish 10 by insert injection molding at one end side of the shaft portion 43 including the head portion 42 covered with the coating resin 45 as will be described in detail later. The In the insert molding, as shown in FIGS. 10 and 11, the fixing member 40 is inserted into the fixing member holding hole 62 formed in the core die 61 of the injection mold 60 from the other end side on the locking portion 44 side. Then, the covering resin 45 portion is arranged in the holding member forming concave portion 63, the molten resin P is injected into the molding cavity C between the core die 61 and the cavity die 65, and the molten resin P is fixed to the core die 61. Retaining part forming recess for member of By filling the fixing member holding portion forming space 64 formed between the inner wall side surface 63a and the coating resin 45 and in the annular groove 46 of the coating resin 45, the cylindrical side wall 31 and the annular locking protrusion at the tip thereof are filled. A fixing member holding portion 30 including the portion 35 is formed on the back surface of the pillar garnish 10. The inner diameter of the fixing member holding hole 62 is larger than the diameter of the locking portion 44 of the fixing member 40 so that the pillar garnish 10 can be removed, so that the shaft portion 43 of the fixing member 40 and the fixing member holding hole are fixed. A space S is formed between the inner peripheral surfaces of 62. Reference numeral 69 denotes a protruding pin.
[0022]
However, when the molten resin P fills the fixing member holding space forming space 64, it is retained by the injection pressure as shown in (I) of FIG. 11 and in-mold holding after the completion of injection as shown in (II) of FIG. Due to the pressure, the molten resin P breaks through the inside of the annular groove 46 of the coating resin 45 and penetrates into the fixing member holding hole 62 of the core mold 61, filling the space S around the shaft portion 43 and hardening. easy. Therefore, the obtained pillar garnish 10 is in a state in which the annular groove 46 is broken, and the head 42 of the fixing member 40 is likely to be poorly held. In order to prevent this problem, the core mold 61 is of a split type so that a space S is not generated between the outer peripheral surface of the shaft portion 43 and the inner peripheral surface of the fixing member holding hole 62 that are not covered with the coating resin 45. However, in that case, the cost of the mold increases, which is not preferable for the workability of the pillar garnish.
[0023]
Therefore, in order to prevent the occurrence of the problem, in the present invention, the coating resin 45 satisfies one or both of the following conditions (A) and (B). (A) The relationship between the groove width t1 of the annular groove 46 and the thickness t2 of the coating resin 45 located outside the fixing member holding portion 30 outside the annular groove 46 is t2> t1. (B) The thickness t3 of the coating resin 45 at the innermost end in the annular groove 46 is 1.5 mm or more. By doing so, the strength at the annular groove 46 portion of the coating resin 45 is improved and can withstand the pressure at the time of the injection molding, and the good fixing member holding portion 30 in which the annular groove 46 is not broken is obtained. can get. The most preferable case is that both (A) and (B) are satisfied. In this example, t1: 1.5 mm, t2: 2.5 mm, and t3: 2.5 mm.
[0024]
Examples of the synthetic resin constituting the coating resin 45 include an olefin elastomer. More preferably, an elastomer having a bending elastic modulus (measured by JISK7203) of the resin constituting the coating resin 45 of 700 MPa or more and a thermal deformation temperature (JISK7207 45.08 N load (4.6 kg load)) of 100 ° C. or more can be used. By selecting the resin as described above, the pillar garnish main body 10 (portion excluding the fixing member 40) can be made into a highly rigid and high temperature heat resistant resin that can withstand the heat and pressure of the resin to be molded. Tensile strength with the resin of the main body is increased.
[0025]
As shown in FIG. 4, the rattling prevention fixing portion 16 has a clip seat 53 formed on the back surface of the pillar garnish 10, and a metal or resin clip 51 is fixed to the seat 53. A clip 51 is inserted into and engaged with a clip hole 29 formed in the inner panel 21 of the vehicle body pillar portion 20. The clip 51 of this example has locking pieces 52 and 52 bent so as to bulge outward, and the pillar garnish 10 is fixed to the vehicle body pillar portion 20 without rattling by attaching the pillar garnish 10 to the vehicle body pillar portion 20. When the pillar garnish 10 is pushed and bent by the inflation of the airbag A, the clip 51 is detached from the clip hole 29 of the inner panel 21. In addition, the clip seat portion 53 has a thin rib shape so as not to cause sink marks on the design surface of the pillar garnish 10.
[0026]
Next, an embodiment of a method for manufacturing the pillar garnish 10 will be described with reference to FIG. The airbag built-in type pillar garnish 10 of the present invention is performed by using a known insert injection molding using an injection mold 60. The injection mold 60 includes a fixed member holding portion forming recess 63 and a predetermined portion of the mold surface. Holding part formation for fixed member Recess of A core die 61 having a fixing member holding hole 62 formed at the center of the inner bottom surface, and a cavity die 65 having a die surface constituting a molding cavity C between the core surfaces of the core die 61. Retaining part forming recess for fixing member 63 The depth of the fixing member 40 is the same as the thickness of the coating resin 45 in the axial length direction of the fixing member 40, and the inner diameter is the same as the diameter of the end of the coating resin 45 opposite to the head 42 of the fixing member 40. ing. Further, the fixing member holding hole 62 is made smaller than the diameter of the coating resin 45 so as to support the coating resin 45, and has a depth that allows the locking portion 44 of the fixing member 40 to be completely accommodated. In addition, the mold surface of the core mold 61 is formed with other necessary concavo-convex shapes such as a recess for the rattle for preventing rattling, and the molding cavity C is formed in a pillar garnish shape. Reference numeral 69 denotes a product ejection pin.
[0027]
Then, the rod-shaped fixing member 40 in which the annular groove 46 is formed on the outer periphery of the side surface of the coating resin 45 is inserted into the fixing member holding hole 62 of the core mold 61 from the other end side opposite to the enlarged head portion 42 and covered. The resin 45 is disposed in the fixing member holding portion forming recess 63, and the molding cavity C is formed by the gap between the inner wall side surface 63a and the coating resin 45 side surface of the fixing member holding portion forming recess 63 and the annular groove 46 of the coating resin 45. The fixing member holding portion forming space 64 is configured. Next, by injecting the molten resin P into the molding cavity C, the side wall 31 is formed into a substantially cylindrical shape on the back surface of the pillar garnish 10 and enters the end of the side wall 31 in the annular groove 46 on the side surface of the coating resin 45. A fixing member holding portion 30 having an inward annular locking projection 35 is formed to protrude.
[0028]
In the manufacturing, in order not to cause the trouble shown in FIG. 4, that is, in order to prevent the molten resin P from breaking the annular groove 46 of the coating resin 45, the following (A), (B), ( It is preferable that at least one condition of c) is satisfied.
(A) The relationship between the groove width t1 of the annular groove 46 and the thickness t2 of the coating resin 45 located outside the holding member holding portion outside the annular groove 46 is t2> t1.
(B) The thickness t3 of the coating resin 45 at the innermost end in the annular groove 46 is 1.5 mm or more.
(C) The relationship between the inner diameter W1 of the fixing member holding hole 62 of the core mold 61 and the diameter W2 of the innermost coating resin 45 in the annular groove 46 is W2 ≧ W1.
As described above, (A) and (B) are the conditions for improving the strength of the coating resin 45 as described above. (C) shows that the front end surface of the coating resin 45 outside the annular groove 46 is held by a fixing member during injection molding. The molten resin P supported by the fixing member holding portion forming concave portion 63 around the periphery of the hole 62 is prevented from destroying the coating resin 45 in the annular groove 46. The most preferable case is when all the conditions (a), (b), and (c) are satisfied.
When the molding die 60 is opened after the injection is completed and the molded product is pushed out by the protruding pin 69, the pillar garnish 10 shown in FIGS. 1 to 4 is obtained.
[0029]
The structure of the attachment preventing portion 15 for preventing detachment in the pillar garnish of the present invention is not limited to the structure described above, but on the inner periphery of the side wall 31A of the fixing member holding portion 30A as in the pillar garnish 10A shown in FIGS. Two annular locking projections 35A and 35A that are separated in the axial direction of the fixing member 40A are formed, and the outer periphery of the side surface of the coating resin 45A of the rod-shaped fixing member 40A corresponds to the two annular locking projections 35A and 35A. Two annular grooves 46A, 46A are formed at the positions, and the corresponding annular locking protrusions 35A, 35A are inserted into the two annular grooves 46A, 46A, respectively. A structure that satisfies either or both of the conditions (e) and (e) is also preferred. The mounting portion 16 for preventing rattling is the same as the pillar garnish 10 of the above embodiment. In the figure, the same members are denoted by the same reference numerals.
(D) The thickness t3a of the coating resin 45A at the innermost end of the annular groove 46A located on the distal end side of the fixing member holding portion 30A is 1.5 mm or more.
(E) The relationship between the groove width t1a of the annular groove 46A located on the front end side of the fixing member holding portion 30A and the protruding dimension t2a of the coating resin 45A from the front end of the fixing member holding portion 30A is t2a> t1a. .
This condition, like the pillar garnish 10 of the above-described embodiment, increases the strength of the coating resin 45A at the time of injection molding, and prevents the problem of FIG. Of course, the most preferable case is that both (d) and (e) are satisfied.
[0030]
As a manufacturing method for the pillar garnish 10A of this embodiment, an injection mold 60 having a molding cavity C similar to the manufacturing of the pillar garnish 10 is used, and two annular grooves 46A and 46A are formed on the outer periphery of the side surface of the coating resin 45A. The rod-shaped fixing member 40A thus formed is inserted into the fixing member holding hole 62 of the core mold 61 from the other end opposite to the enlarged head 42, and the coating resin 45A is disposed in the fixing member holding portion forming recess 63. The gap between the inner wall side surface 63a of the fixing member holding portion forming recess 63 and the side surface of the coating resin 45A and the two annular grooves 46A and 46A of the coating resin 45A constitute a fixing member holding portion forming space 64A of the molding cavity. To do. Then, by injecting the molten resin P into the molding cavity C, the side wall 31A is substantially cylindrical on the back surface of the pillar garnish 10A, and the two annular grooves 46A and 46A of the coating resin 45A are formed on the inner peripheral surface of the side wall 31A. An airbag built-in type pillar garnish 10A in which a fixing member holding portion 30A having two annular locking projections 35A and 35A that have entered into the interior is projected.
[0031]
In the manufacturing method, it is preferable that at least one of the following conditions (d), (e), and (f) is satisfied.
(D) The thickness t3a of the coating resin 45A at the innermost end of the annular groove 46A located on the distal end side of the fixing member holding portion 30A is 1.5 mm or more.
(E) The relationship between the groove width t1a of the annular groove 46A located on the front end side of the fixing member holding portion 30A and the protruding dimension t2a of the coating resin 45A from the front end of the fixing member holding portion 30A is t2a> t1a. .
(F) The relationship between the inner diameter W1 of the fixing member holding hole 62 of the core mold 61 and the diameter W2a of the innermost coating resin 45A in the annular groove 46A located on the distal end side of the fixing member holding portion 30A is W2a ≧ W1.
These conditions are (d), (e) reinforced coating resin 45A so that it can withstand the resin pressure at the time of molding, and (f) is the coating resin 45A around annular grooves 46A, 46A. It is supported by the holding portion forming concave portion 63 and prevents the molten resin P from destroying the coating resin 45A. The most preferable case is when all of (d), (e), and (f) are satisfied. is there.
[0032]
In the vehicle body pillar portion 20 to which the pillar garnish 10 (10A) thus constructed is attached, the clip hole 29 and the locking hole 25 as shown in FIG. It is formed corresponding to the position of the fixing member holding portion 30 (30A) for the fixing member of the garnish 10. The locking hole 25 is a long hole having a predetermined length along the longitudinal direction of the pillar garnish 10 (10A), and has a large diameter hole 26 through which the locking portion 44 of the fixing member 40 (40A) can be inserted at the lower end. A shaft portion insertion passage 27 having a size smaller than the diameter of the locking portion 44 and having a size through which the shaft portion 43 (43A) can be inserted extends. When the pillar garnish 10 is attached, first, the locking portion 44 of the fixing member 40 (40A) is inserted into the large-diameter hole 26 of the locking hole 25, and the shaft is inserted into the upper end 28 of the shaft portion insertion passage 27. The pillar garnish 10 is slid upward along the vehicle body pillar portion 20 until the portion 43 (43A) collides. As a result, the clip 51 moves onto the clip hole 29 of the inner panel 21. Next, if the pillar garnish 10 is strongly pushed to the inner panel 21 side at that position and the clip 51 is inserted and engaged with the clip hole 29, the attachment of the pillar garnish 10 (10A) is completed.
[0033]
When the pillar garnish 10 (10A) attached to the vehicle body pillar portion 20 is pushed and bent toward the vehicle interior side due to inflation of the airbag A, the locking portion 44 of the fixing member 40 (40A) is By engaging with the shaft portion insertion passage 27 of the locking hole 25 of the inner panel 21 (abutting against the back surface of the shaft portion insertion passage 27), it is prevented from coming off from the vehicle body pillar portion 20. Note that a clip or the like for preventing rattling may be appropriately provided on the shaft portion 43 portion of the fixing member 40 (40A) not covered with the coating resin 45 (45A).
[0034]
【The invention's effect】
As described above, according to the air bag built-in type pillar garnish of the invention of claim 1, the fixing member whose head is previously covered with the synthetic resin coating resin is integrated with the back surface of the pillar garnish at the time of insert injection molding. The fixed member holding portion is housed and held in a protruding shape, and the fixing member holding portion is provided with an annular locking protrusion, and an annular groove is formed in the coating resin, and the fixing member is held to the back of the annular groove. Since the peripheral edge of the annular locking projection at the tip of the head part is inserted and locked, the appearance of the design surface is good and the pillar garnish is prevented from coming off when the airbag is inflated. can do. Furthermore, by satisfying at least one of the conditions (a) and (b), it is possible to extremely reduce molding defects and to obtain a highly accurate pillar garnish.
[0035]
Furthermore, according to the pillar garnish of claim 2, the fixing member whose head is previously covered with the synthetic resin coating resin is accommodated and fixed in the fixing member holding portion that is integrally projected and formed on the back surface of the pillar garnish at the time of insert injection molding. The fixing member holding portion is provided with two annular locking protrusions, and two annular grooves are formed at the corresponding positions in the coating resin, and the tip of the fixing member holding portion is annularly formed to the back of the annular groove. Since the locking projection has a structure in which the periphery of the locking protrusion enters and locks, the pillar garnish can be reliably prevented from coming off when the airbag is inflated, as well as the occurrence of sink marks. So the appearance will be good. Further, by satisfying at least one of the above conditions (d) and (e), it is possible to extremely reduce the number of defective moldings and to obtain a highly accurate pillar garnish.
[0036]
Furthermore, according to the manufacturing method of the invention of claim 3, by satisfying at least one of the conditions (a), (b), and (c), and according to the manufacturing method of the invention of claim 4, the By satisfying at least one of the conditions (d), (e), and (f), a pillar garnish that does not easily disengage when the airbag is inflated and has a good appearance is produced with less molding defects and high accuracy. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a vehicle interior to which an airbag built-in type pillar garnish of the present invention is attached.
2 is a cross-sectional view taken along the line 2-2 of FIG.
FIG. 3 is an enlarged cross-sectional view showing the vicinity of the fixing member in FIG. 2;
4 is a cross-sectional view taken along line 4-4 of FIG.
FIG. 5 is a partial cross-sectional view of the mold showing the manufacturing process of the pillar garnish of FIG. 1;
6 is a cross-sectional view at the same position as 2-2 in FIG. 1, showing the vicinity of a fixing member of a pillar garnish according to another embodiment.
7 is an enlarged cross-sectional view showing the vicinity of the fixing member in FIG. 6. FIG.
FIG. 8 is a partial cross-sectional view of a mold showing the manufacturing time of the pillar garnish of FIG. 6;
FIG. 9 is a perspective view showing a locking hole of the inner panel.
FIG. 10 is a partial cross-sectional view of a molding die showing the first half of manufacturing a conventional pillar garnish.
FIG. 11 is a partial cross-sectional view of a mold showing the latter half of the manufacturing process of the pillar garnish.
FIG. 12 is a schematic view of the inside of a vehicle compartment to which a conventional air bag built-in type pillar garnish is attached.
FIG. 13 is a schematic view showing when the airbag is inflated.
14 is a sectional view taken along line XX in FIG.
[Explanation of symbols]
10 Pillar Garnish
20 Body pillar part
25 Locking hole
30 Holding part for fixing member
35 Annular locking projection
40 Fixing member
42 Fixed member head
43 Fixed member shaft
44 Fixing member locking part
45 Coating resin
46 annular groove
60 Mold
61 Core type
62 Fixing member holding hole
63 Retaining part forming recess for fixing member
65 cavity mold
P Molten resin
A Airbag
t1 Groove width of annular groove
t2 Thickness of the coating resin located outside the holding part for the fixing member outside the annular groove
t3 Thickness of the coating resin at the innermost end of the annular groove
W1 Inner diameter of core type fixing member holding hole
W2 Diameter of the innermost coating resin in the annular groove

Claims

Fixing member holding portion which is substantially cylindrical side wall to the rear surface of the pillar garnish made of injection-molded article is protruded, to the fixing member retaining portion, the head portion from the middle of the shaft portion enlarged end of the shaft portion An air bag in which a rod-shaped fixing member covered with a coating resin is accommodated and held on one end side including the head portion and protrudes from the fixing member holding portion from the portion covered with the coating resin in the middle of the shaft portion to the other end side In the built-in pillar garnish,
An inward annular locking projection is formed at the tip of the fixing member holding portion,
An annular groove is formed on the outer periphery of the side surface of the coating resin, and the inner peripheral edge of the annular locking projection at the distal end of the holding part for the fixing member enters into the annular groove and engages, and the following (A), ( B) Pillar garnish with a built-in airbag, characterized by satisfying either or both of the conditions.
(A) The relationship between the groove width t1 of the annular groove and the thickness t2 of the coating resin located outside the holding member holding portion outside the annular groove is t2> t1.
(B) The thickness t3 of the coating resin at the innermost end in the annular groove is 1.5 mm or more.

A fixing member holding portion having a substantially cylindrical side wall is formed on the back surface of a pillar garnish made of an injection-molded product, and the head portion in which one end of the shaft portion is enlarged from the middle of the shaft portion in the fixing member holding portion. The rod-shaped fixing member covered with the coating resin is accommodated and held on one end side including the head, and the air protrudes from the fixing member holding portion from the portion covered with the coating resin in the middle of the shaft portion to the other end side. In the bag built-in pillar garnish,
In the fixing member holding portion, two annular locking projections are formed on the inner periphery of the side wall apart from each other in the length direction of the side wall,
Two annular grooves are formed at positions corresponding to the annular locking projections on the outer periphery of the side surface of the coating resin, and the corresponding annular locking projections are inserted into the two annular grooves and locked. In addition, an air bag built-in pillar garnish characterized by satisfying one or both of the following conditions (d) and (e).
(D) The thickness t3a of the coating resin at the innermost end of the annular groove located on the distal end side of the holding part for the fixing member is 1.5 mm or more.
(E) The relationship between the groove width t1a of the annular groove located on the front end side of the fixing member holding portion and the protruding dimension t2a of the coating resin from the front end of the fixing member holding portion is t2a> t1a.

A mold cavity between a core mold having a fixing member holding portion forming recess on the mold surface and a fixing member holding hole formed in the center of the inner bottom surface of the fixing member holding portion forming recess, and the mold surface of the core mold Using a mold composed of a cavity mold having a mold surface constituting
A rod-shaped fixing member in which an annular groove is formed on the outer periphery of the side surface of the coating resin that covers the shaft portion from the middle of the shaft portion to the enlarged head portion at one end of the shaft portion by the coating resin is opposite to the expansion head. Is inserted into the core-type fixing member holding hole from the other end side, and the coating resin is disposed in the fixing member holding portion forming recess, and the gap between the inner wall side surface and the coating resin side surface of the fixing member holding portion forming recess A holding member forming space for the fixing member of the molding cavity is constituted by the annular groove of the coating resin,
By injecting molten resin into the molding cavity, an inward annular locking projection that enters the back of the pillar garnish and has a substantially cylindrical side wall and enters the inner end of the annular groove on the side surface of the coating resin. In the method of manufacturing the airbag built-in type pillar garnish in which the holding part for the fixing member having the protrusion is formed,
An air bag built-in pillar garnish manufacturing method that satisfies at least one of the following conditions (a), (b), and (c):
(A) The relationship between the groove width t1 of the annular groove and the thickness t2 of the coating resin located outside the holding member holding portion outside the annular groove is t2> t1.
(B) The thickness t3 of the coating resin at the innermost end in the annular groove is 1.5 mm or more.
(C) The relationship between the inner diameter W1 of the core-type fixing member holding hole and the diameter W2 of the innermost coating resin in the annular groove is W2 ≧ W1.

A mold cavity between a core mold having a fixing member holding portion forming recess on the mold surface and a fixing member holding hole formed in the center of the inner bottom surface of the fixing member holding portion forming recess, and the mold surface of the core mold Using a mold composed of a cavity mold having a mold surface constituting
From the middle of the shaft portion to the one end enlarged head of the shaft portion is covered with a coating resin rod shape two annular grooves in the coating resin wall part covering the shaft portion is formed apart in the longitudinal direction of the shaft portion The fixing member is inserted into the fixing member holding hole of the core type from the other end side opposite to the enlarged head, and the coating resin is arranged in the fixing member holding portion forming recess, and the fixing member holding portion forming recess A space between the inner wall side surface and the coating resin side surface and two annular grooves of the coating resin constitute a holding part forming space for the fixing member of the molding cavity,
By injecting molten resin into the molding cavity, two annular locks are formed on the back surface of the pillar garnish, with the side wall being substantially cylindrical, and entering the inner peripheral surface of the side wall into the interior of the two annular grooves of the coating resin. In the method of manufacturing the airbag built-in type pillar garnish in which the holding part for the fixing member having the protrusion protrudes,
An air bag built-in type pillar garnish manufacturing method characterized by satisfying at least one of the following conditions (d), (e), and (f).
(D) The thickness t3a of the coating resin at the innermost end of the annular groove located on the distal end side of the holding part for the fixing member is 1.5 mm or more.
(E) The relationship between the groove width t1a of the annular groove located on the front end side of the fixing member holding portion and the protruding dimension t2a of the coating resin from the front end of the fixing member holding portion is t2a> t1a.
(F) The relationship between the inner diameter W1 of the core-type fixing member holding hole and the diameter W2a of the innermost coating resin in the annular groove located on the distal end side of the fixing member holding portion is W2a ≧ W1.