JP4133451B2

JP4133451B2 - Interior parts for automobile, manufacturing method thereof and molding die

Info

Publication number: JP4133451B2
Application number: JP2003055639A
Authority: JP
Inventors: 哲行大田; 正彦原; 伸明関; 樹史大野; 洋行相澤
Original assignee: Kasai Kogyo Co Ltd
Current assignee: Kasai Kogyo Co Ltd
Priority date: 2003-03-03
Filing date: 2003-03-03
Publication date: 2008-08-13
Anticipated expiration: 2023-03-03
Also published as: JP2004262119A

Description

【０００１】
【発明の属する技術分野】
この発明は、ドアトリム、リヤパーセルシェルフ、フロアトリム、トランクトリム、リヤサイドトリム等の自動車用内装部品及びその製造方法並びに成形金型に係り、特に、軽量でかつ外周端末部の見栄え並びに機械強度に優れ、しかも、簡単かつ廉価に製作できる自動車用内装部品及びその製造方法並びに成形金型に関する。
【０００２】
【従来の技術】
例えば、自動車用内装部品の構成をドアトリムを例示して図２０，図２１を基に説明する。ドアトリム１は、保形性及び車体パネルへの取付剛性を備え、製品面のほぼ全面にゆきわたっている樹脂芯材２の表面に、表面外観に優れた表皮３を積層一体化して構成されている。
【０００３】
上記樹脂芯材２としては、タルクを混入したポリプロピレン系樹脂を素材としており、また、表皮３は、それ自体保形性を備えておらず、塩ビシート等の合成樹脂シート裏面にポリエチレンフォーム等のクッション材が積層された積層シート材料が使用され、最近では、環境面やリサイクル面を考慮して、ＴＰＯ（サーモプラスチックオレフィン）シート等のエラストマーシートが多用される傾向にある。
【０００４】
次に、上記ドアトリム１の成形方法における従来例について図２２を基に説明する。まず、ドアトリム１を成形する成形金型４は、所定ストローク上下動可能な成形上型５と、成形上型５と対をなす固定側の成形下型６と、成形下型６と接続される射出機７とから大略構成されている。
【０００５】
そして、成形上下型５，６を型締めした際、ドアトリム１の製品形状を形造るために成形上型５にはキャビティ部５ａが形成され、成形下型６にはコア部６ａが設けられている。上記成形上型５を所定ストローク上下動作させるために、昇降シリンダ５ｂが連結され、成形下型６には射出機７からの溶融樹脂の通路となるマニホールド６ｂ、ゲート６ｃが設けられている。
【０００６】
また、上下動作する成形上型５は、適正姿勢を維持させるために、成形下型６の４隅部にガイドポスト６ｄが設けられ、このガイドポスト６ｄに対応して成形上型５にはガイドブッシュ５ｃが設けられている。
【０００７】
従って、成形上下型５，６が型開き状態にあるとき、表皮３を金型内にセットし、その後、成形上下型５，６を型締めする直前か、または型締めした後のいずれかのタイミングで両金型間の製品キャビティ内に射出機７からマニホールド６ｂ、ゲート６ｃを通じて溶融樹脂Ｍを射出充填することにより、樹脂芯材２を所要の曲面形状に成形するとともに、樹脂芯材２の表面に表皮３を一体成形している（例えば、特許文献１参照。）。
【０００８】
尚、図２２では、説明の便宜上、コア部６ａの型面にオープン状態で溶融樹脂Ｍが供給されているが、実際は、溶融樹脂Ｍは成形上下型５，６の型締め後にキャビティ内に射出充填されても良い。
【０００９】
更に、ドアトリム１の製品の外周端末の処理については、図２３に示すように、芯材２の表面に表皮３を同時プレス成形した後、型内の型刃、あるいは成形後、別工程でピアスカット処理が行なわれている。
【００１０】
また、図２４に示すように、芯材２のプレス成形後、表皮３を別工程で真空圧着、プレス圧着等により一体化した後、表皮３の端末３ａを芯材２の裏面側に巻込み処理することも従来から行なわれている。
【００１１】
【特許文献１】
特開平１０−１３８２６８号公報（第２頁、図３、図４）
【００１２】
【発明が解決しようとする課題】
しかしながら、従来のドアトリム１においては、樹脂芯材２の投影面積が大きいため、材料コストが高く、かつ製品が重量化するという問題点が指摘されている。
【００１３】
また、樹脂芯材２の投影面積が大きいことから、成形時における射出圧を高く設定せざるを得ず、高い射出圧に耐え得る金型構造が必要となり、金型の作製費用も嵩み、しかも、大量の溶融樹脂を冷却固化させるため、成形サイクルが長期化し、生産性を低下させる大きな要因となっている。
【００１４】
更に、ドアトリム１の外周縁においては、図２３に示すように、表皮同時プレス成形を行なった場合、外周の端末処理が困難で、見栄えが悪く、外観性能を低下させる欠点があるとともに、図２４に示すように、別工程で表皮３を巻込み処理する方法では、工数が多く、コストアップが避けられない。
【００１５】
本発明は、このような事情に鑑みてなされたもので、軽量化を促進でき、高剛性でコストダウンを図れる自動車用内装部品を提供でき、成形金型費用を低減でき、成形サイクルも短縮化できるとともに、特に、製品外周端末部の見栄え並びに剛性を高めることで、外観性能を向上させた自動車用内装部品及びその製造方法並びに成形金型を提供することを目的とする。
【００１６】
【課題を解決するための手段】
本発明者らは、上記課題を解決するために、鋭意研究の結果、従来から表皮として使用していた発泡樹脂シートに保形性を付与することで、芯材としての機能をもたせ、より以上に剛性が必要な箇所、すなわち製品の周縁部分やパネル、相手部品との合わせ部で密接可能、または一定クリアランスを確保する箇所、あるいは部品取付箇所並びに荷重がかかる部分には、剛性に優れた樹脂リブを配置することで従来の投影面積の広い樹脂芯材に比べ軽量化して対応するとともに、製品の外周端末処理については、発泡樹脂基材に巻込み部を付設するだけで、簡単かつ美麗に端末処理を達成できることを見い出し、本発明を完成するに至った。
【００１７】
すなわち、本発明に係る自動車用内装部品は、発泡樹脂シートを圧縮加工してなり、軽量で、かつ保形性を有する発泡樹脂基材と、この発泡樹脂基材の裏面に積層一体化される投影面積が低減化された樹脂リブと、上記発泡樹脂基材の表面に積層一体化される加飾材とからなる自動車用内装部品であって、製品外周のやや内側に沿って、発泡樹脂基材に設けられた薄肉ヒンジ部を基に該薄肉ヒンジ部外周の巻込みシロを発泡樹脂基材の裏面に巻込み処理することにより、端末部分の剛性を強化したことを特徴とする。
【００１８】
更に、本発明の別の実施態様は、軽量で、かつ保形性を有する発泡樹脂基材と、この発泡樹脂基材の裏面に積層一体化される樹脂リブと、上記発泡樹脂基材の表面に積層一体化される加飾材とからなる自動車用内装部品であって、製品外周の内側に沿って設定された折返しラインから外周端末にかけて発泡樹脂基材が切削され、可撓性を備えた巻込みシロとして形成され、該折返しラインを基に発泡樹脂基材の裏面側に上記巻込みシロを巻込み処理してなることを特徴とする。
【００１９】
ここで、自動車用内装部品としては、ドアトリム、リヤパーセルシェルフ、フロアトリム、ラゲージトリム、トランクトリム、リヤサイドトリム等に適用できる。
【００２０】
軽量で、かつ保形性を有する発泡樹脂基材は、フラット形状に近い場合は、加熱軟化工程を省略して、成形型により所望形状に成形するが、三次元形状の製品に適用する場合は、発泡樹脂シートを加熱軟化処理した後、成形金型内で所要の曲面形状に成形することで、その形状を保持する。尚、ここで言う「保形性」とは、リブ等の補強材がなくても、成形後脱型したとき、その形状を保持する程度の剛性を備えていることである。また、製品形状が高展開率部分を含む場合には、発泡樹脂シートを加熱軟化処理した後、成形金型に真空吸引機構を配設して成形金型の内面に沿って発泡樹脂シートに真空吸引力を作用させるようにしても良い。
【００２１】
上記発泡樹脂シートとしては、熱可塑性樹脂に発泡剤を添加した素材を使用する。尚、熱可塑性樹脂は、１種類の熱可塑性樹脂でも２種類以上の熱可塑性樹脂からなっても良い。好ましくは、ポリエチレン系樹脂、ポリプロピレン系樹脂、ポリスチレン系樹脂、ポリエチレンテレフタレート系樹脂、ポリビニルアルコール系樹脂、塩化ビニル系樹脂、アイオノマー系樹脂、アクリロニトリル／ブタジエン／スチレン（ＡＢＳ）樹脂などが使用できる。
【００２２】
また、発泡剤としては、アゾ化合物、スルホヒドラジド化合物、ニトロソ化合物、アジド化合物等の有機発泡剤、あるいは重炭酸ナトリウム等の無機発泡剤の使用が可能である。
【００２３】
上記発泡樹脂シートを加熱軟化処理後、所要形状に成形して得た発泡樹脂基材は、製品の重量と強度とのバランスを考慮した場合、２〜１０倍の発泡倍率が好ましい。そのときの発泡樹脂基材のセル径は、０．１μｍ〜２．０ｍｍの範囲であることが好ましく、厚みは０．５〜３０ｍｍ、好ましくは１〜１０ｍｍのものが良い。
【００２４】
一方、樹脂リブとして使用する熱可塑性樹脂材料は、広範な熱可塑性樹脂から適宜選択することができる。通常好ましく使用できるものとして、ポリエチレン系樹脂、ポリプロピレン系樹脂、ポリスチレン系樹脂、ポリエチレンテレフタレート系樹脂、ポリビニルアルコール系樹脂、塩化ビニル系樹脂、アイオノマー系樹脂、ポリアミド系樹脂、アクリロニトリル／ブタジエン／スチレン（ＡＢＳ）樹脂、ポリカーボネート樹脂等が使用できる。
【００２５】
また、これら熱可塑性樹脂中に各種充填剤を混入しても良い。使用できる充填剤としては、ガラス繊維、カーボン繊維等の無機繊維、タルク、クレイ、シリカ、炭酸カルシウム等の無機粒子などがある。また、酸化防止剤、紫外線吸収剤、着色剤、難燃剤、低収縮剤等の各種の添加剤が配合されても良い。
【００２６】
そして、外観意匠性を高めるために、発泡樹脂基材の表面に積層一体化される加飾材としては、織布、不織布、編布、シート、フィルム、発泡体、網状物などが使用できる。これら加飾材を構成する材料は特に限定されないが、織布、不織布、編布等、通気性を有する素材を使用したほうが、発泡樹脂基材の吸音性能を生かす上で好ましい。また、加飾材としてＴＰＯシートを使用した場合、材料をオレフィン系樹脂に統一できることから、リサイクル作業を円滑に行なえる。
【００２７】
更に、内装部品の外周縁は、折返しラインとなる薄肉ヒンジ部が発泡樹脂基材に形成されており、この薄肉ヒンジ部を基に外側の巻込みシロが発泡樹脂基材の裏面側に巻込み処理されている。
【００２８】
また、端末処理の別態様としては、折返しラインから外側部分における発泡樹脂基材が削り取られ、折返しラインより外側部分がほぼ加飾材のみの可撓性を備えた巻込み部として形成され、この巻込み部を発泡樹脂基材の裏面側に巻込み処理すれば良い。
【００２９】
そして、本発明に係る自動車用内装部品によれば、保形性を有する発泡樹脂基材の表面側に加飾性を有する加飾材が積層され、かつ裏面側に剛性を強化する意味で樹脂リブが積層一体化されるという構成であるため、従来の樹脂芯材を廃止することができる。従って、従来の投影面積の非常に広い樹脂芯材を廃止することで、製品の軽量化を図ることができ、しかも、樹脂材料を節約できることから、材料コストの低減化も同時に達成できる。
【００３０】
更に、内装部品の外周部については、薄肉ヒンジ部を折返し基点に外側部分を巻込みシロとして巻込み処理されるため、切断木口等が外部に目立たず、外観意匠性に優れ、かつ端末部分は、発泡樹脂基材が二重構造となり、剛性も強化できる。
【００３１】
更に、発泡樹脂基材の折返しラインより外側部分の発泡樹脂基材を削り取る構成を採用すれば、切断木口が外部に目立たないとともに、ほぼ加飾材のみの巻込み部の構成となるため、可撓性を有することから、巻込み作業が円滑に行なえる。
【００３２】
加えて、発泡樹脂基材の多孔質吸音機能により、吸音性能に優れた内装部品が得られるとともに、発泡樹脂基材及び樹脂リブの素材として、ポリオレフィン系樹脂を使用した場合、オールオレフィン系樹脂に統一されるため、分離工程が廃止でき、リサイクル作業が簡素化できる。
【００３３】
更に、樹脂リブのリブ厚みは、例えば、製品に外力が大きく加わる部位などはリブ厚みを厚く設定し、比較的外力が加わりにくい部位はリブ厚みを薄肉にするなど、リブ厚みを適宜可変させることができる。従って、必要最小限度の樹脂材料を使用すれば足り、製品の軽量化やコストダウンに寄与できる。また、樹脂リブにクリップ座、あるいは各種エスカッション部品を取り付けるための取付座を一体に形成することもできる。
【００３４】
次いで、本発明に係る自動車用内装部品の製造方法は、軽量で、かつ保形性を有する発泡樹脂基材と、該発泡樹脂基材の裏面に積層一体化される樹脂リブと、上記発泡樹脂基材の表面に積層一体化される加飾材とからなる自動車用内装部品の製造方法において、成形金型内に加飾材を積層してなる発泡樹脂シートをセットする発泡樹脂シートのセット工程と、成形金型同士を型締めして、成形金型の製品キャビティ形状に発泡樹脂基材を所要形状に成形し、上記発泡樹脂基材の外周縁からやや内側の折返しラインに沿って薄肉ヒンジ部を形成する一方、成形金型の型締め直前、または型締め後のいずれかのタイミングで成形下型の溝部内に溶融樹脂を射出充填して、樹脂リブを発泡樹脂基材の裏面側に積層一体化する発泡樹脂基材と樹脂リブの一体化工程と、一体化した積層品を成形金型の型開き後、脱型し、巻込みシロを上記薄肉ヒンジ部を基に発泡樹脂基材の裏面に折返し固着する内装部品の端末処理工程とからなることを特徴とする。
【００３５】
ここで、本発明方法に使用する成形金型は、所定ストローク上下動可能な成形上型と、この成形上型の下方側に位置する固定側である成形下型と、成形下型に連結される射出機から構成される。
【００３６】
射出機から供給される溶融樹脂は、成形下型に設けられたマニホールド、ゲート等の樹脂通路を通じて成形下型の型面、詳しくは、成形下型の型面上に形成される溝部内に供給されるが、成形上型が下死点まで下降して、成形上下型を型締めした後、溶融樹脂を所定の射出圧で成形下型の型面に設けられた溝部に射出充填しても良いが、溶融樹脂の射出充填のタイミングとして、型締め前に行なうようにしても良い。
【００３７】
更に、成形上下型の型面は、製品形状に合致する所望の曲面形状に設定されているが、外周端末部の巻込み処理を考慮して、成形上下型のいずれか一方側に凸条が設けられ、巻込みシロの折返し基点となる薄肉ヒンジ部が発泡樹脂基材に形成される。
【００３８】
従って、成形上下型の型締めにより、発泡樹脂シートは成形金型の型面形状に沿って所望の曲面形状に成形されるとともに、外周縁に沿うやや内側には薄肉ヒンジ部が形成されることになる。更に、溶融樹脂が射出充填されることで、発泡樹脂基材の裏面に樹脂リブが積層一体化される。
【００３９】
そして、製品形状が三次元形状に設定されている場合には、全工程でヒーター等により加熱軟化処理を行なった後、発泡樹脂シートを成形金型内にセットする。
【００４０】
更に、成形金型内に加熱軟化状態の発泡樹脂シートを供給した後、成形金型を型締めすれば、所望形状に成形された保形性を有する発泡樹脂基材が得られ、この発泡樹脂基材には、巻込みシロの折返し処理の際、折返し基点となる薄肉ヒンジ部が形成される。
【００４１】
そして、発泡樹脂基材の成形と同時に、発泡樹脂基材裏面に樹脂リブを積層一体化すれば良い。尚、最終製品形状が高展開率部分を備えている場合には、成形金型の型締めを複数回行ない、最終の型締め工程で溶融樹脂の射出充填を行なうと良い。また、製品形状がより高展開率部分を含む場合には、成形上型に真空吸引機構を配設し、成形上型の型面に沿って真空吸引力により発泡樹脂基材を所要形状に成形するのが良い。
【００４２】
従って、本発明方法によれば、従来の投影面積の広い樹脂芯材に比べ、樹脂リブだけを成形するため、射出圧力を従来に比べて低く設定できることにより、成形金型の負荷が少なくて済むとともに、樹脂量も少なく、材料費を節約でき、しかも、従来の樹脂芯材に比べ、冷却時間も少なくて済むため、製品の成形サイクルも短縮化できる。
【００４３】
更に、端末処理工程としては、加飾材、発泡樹脂基材、樹脂リブを一体化した積層成形体を成形金型から取り出し、発泡樹脂基材に設けられている薄肉ヒンジ部を折返し基点として外周に沿う巻込みシロを発泡樹脂基材の裏面に折返し固着すれば良く、製品の外周縁は薄肉ヒンジ部が対応するため、シャープな外周ラインが確保でき、かつ端末部分は二重構造であるため、剛性が強化でき、変形の恐れがない。
【００４４】
次いで、本発明方法の別の実施態様としては、前記発泡樹脂基材と樹脂リブの一体化工程において、成形金型同士を型締めして、成形金型の製品キャビティ形状に発泡樹脂基材を成形し、成形金型の型締め直前、または型締め後のいずれかのタイミングで成形下型の溝部内に溶融樹脂を射出充填して、樹脂リブを発泡樹脂基材の裏面側に積層一体化する一方、成形下型の外周のうち、巻込み処理する部位に沿って押圧機構が設けられ、該押圧機構における押圧ブロックが駆動シリンダにより上下駆動され、発泡樹脂基材の外周縁からやや内側に沿って巻込みシロの折返し基点となる薄肉ヒンジ部が形成されることを特徴とする。
【００４５】
ここで、該方法に使用する成形金型は、軽量で、かつ保形性を有する発泡樹脂基材と、該発泡樹脂基材の裏面に積層一体化される樹脂リブと、上記発泡樹脂基材の表面に積層される加飾材とからなる自動車用内装部品を成形する成形金型であって、前記成形金型は、相互に型締め、型開き可能な成形上型並びに成形下型と、成形下型に連結され、樹脂リブの素材である溶融樹脂を供給する射出機とから構成され、前記成形上下型間の製品キャビティは、発泡樹脂基材の製品形状に即した形状に設定されるとともに、樹脂リブに対応する溝部が成形下型のコア部型面に設けられ、かつ成形下型の外周縁部に沿って、発泡樹脂基材の巻込みシロの折返し基点となる薄肉ヒンジ部を形成するための押圧機構が配置されていることを特徴とする。
【００４６】
また、本発明方法の更に別の実施態様としては、軽量で、かつ保形性を有する発泡樹脂基材と、該発泡樹脂基材の裏面に積層一体化される樹脂リブと、上記発泡樹脂基材の表面に積層される加飾材とからなる自動車用内装部品の製造方法において、成形金型内に加飾材を積層してなる発泡樹脂シートをセットする発泡樹脂シートのセット工程と、成形金型同士を型締めして、成形金型の製品キャビティ形状に沿って発泡樹脂基材を成形し、発泡樹脂基材の製品端縁部に沿って、成形下型の壁面に形成した鋸刃形状により、巻込みシロに相当する発泡樹脂基材を削ぎ落とし、成形金型の型締め直前、または型締め後のいずれかのタイミングで成形下型の溝部内に溶融樹脂を射出充填して、樹脂リブを発泡樹脂基材の裏面側に積層一体化する発泡樹脂基材と樹脂リブの一体化工程と、成形金型から樹脂リブを一体化した発泡樹脂基材を脱型し、発泡樹脂基材を削ぎ落とした薄肉状の可撓性を有する巻込みシロを発泡樹脂基材裏面に折返し固着する内装部品の端末処理工程とからなることを特徴とする。
【００４７】
そして、これに使用する成形金型は、軽量で、かつ保形性を有する発泡樹脂基材と、該発泡樹脂基材の裏面に積層一体化される樹脂リブと、上記発泡樹脂基材の表面に積層される加飾材とからなる自動車用内装部品を成形する成形金型であって、この成形金型は、相互に型締め、型開き可能な成形上型並びに成形下型と、成形下型に連結され、樹脂リブの素材である溶融樹脂を供給する射出機とから構成され、前記成形下型の外周面には、発泡樹脂基材の外周縁の巻込みシロを切削するための鋸刃形状の切削部が設定されていることを特徴とする。
【００４８】
【発明の実施の形態】
以下、本発明に係る自動車用内装部品及びその製造方法並びに成形金型の好適な実施の形態について、自動車用ドアトリム及びその製造方法を例示して説明する。
【００４９】
図１乃至図１２は本発明の第１実施形態を示し、図１はツートンタイプの自動車用ドアトリムを示す正面図、図２は同自動車用ドアトリムの構成を示す断面図、図３は同自動車用ドアトリムにおけるドアトリムアッパーの樹脂リブとドアトリムロアを示す正面図、図４は同自動車用ドアトリムにおけるドアトリムアッパーの外周縁の構成を示す断面図、図５乃至図７は同自動車用ドアトリムの製造方法に使用する成形金型をそれぞれ示し、図５は成形金型の全体図、図６は成形金型におけるドアトリムアッパー形成部分を示す断面図、図７はドアトリムアッパー形成部分における外周部の拡大断面図である。更に、図８乃至図１２は同自動車用ドアトリムの製造方法の各工程を示し、図８は発泡樹脂シートの予熱工程、図９は発泡樹脂シートの成形金型へのセット工程、図１０はドアトリムの成形工程、図１１は巻込みシロの成形工程、図１２は巻込みシロの端末処理工程をそれぞれ示す説明図である。
【００５０】
また、図１３乃至図１５は本発明の第２実施形態を示すもので、図１３，図１４はドアトリムアッパーの外周縁部の巻込みシロの形成工程を示す各説明図、図１５は巻込みシロの端末処理工程を示す説明図である。また、図１６乃至図１９は本発明の第３実施形態を示すもので、図１６，図１７は第３実施形態に使用する成形金型の要部を示す斜視図並びに断面図、図１８は成形金型を使用して巻込み部を形成する説明図、図１９は巻込みシロの端末処理工程を示す説明図である。
【００５１】
まず、図１乃至図１２に基づいて、本発明の第１実施形態を説明する。図１，図２において、ツートンタイプの自動車用ドアトリム１０は、積層構造体からなるドアトリムアッパー２０と樹脂単体品からなるドアトリムロア３０との上下２分割体から構成されている。
【００５２】
ドアトリム１０に装着される機能部品としては、ドアトリムアッパー２０にインサイドハンドルエスカッション１１、パワーウインドウスイッチエスカッション１２が取り付けられている。ドアトリムロア３０には、ドアポケット用開口１３が開設され、その背面側には、図２に示すように、ポケットバックカバー（樹脂成形体からなる）１４が取り付けられており、ドアトリムロア３０のフロント側にスピーカグリル１５が一体あるいは別体に形成されている。
【００５３】
ところで、本発明に係る自動車用ドアトリム１０は、積層構造体であるドアトリムアッパー２０の構造に本発明を適用し、製品の軽量化を図るとともに、外周端末部の見栄えを高め、かつ成形工程、端末処理工程を簡素化したことが特徴である。
【００５４】
すなわち、ドアトリムアッパー２０は、図２に示すように、所望の曲面形状に成形され、保形性を有する発泡樹脂基材２１と、この発泡樹脂基材２１の裏面側に積層一体化される樹脂リブ２２と、発泡樹脂基材２１の表面側に積層一体化される加飾機能をもつ加飾材２３とから大略構成されている。尚、図中符合１６は車体パネルを示す。
【００５５】
また、上記発泡樹脂基材２１は、保形性を備えるように発泡樹脂シートを加熱軟化処理後、所要形状に熱成形、例えば、所望の型面を有する成形金型でコールドプレス成形されるが、更に高展開率部分については、真空成形により発泡樹脂基材２１を賦形しても良い。尚、ジャッキリッド等のリッド部品のようなフラット形状の部品においては、発泡樹脂シートに加熱軟化処理を行なわずにフラット形状に成形することができる。
【００５６】
上記発泡樹脂シートは、汎用の熱可塑性樹脂に発泡剤を添加した構成であり、熱可塑性樹脂としては、ポリエチレン系樹脂、ポリプロピレン系樹脂、ポリスチレン系樹脂、ポリエチレンテレフタレート系樹脂、ポリビニルアルコール系樹脂、塩化ビニル系樹脂、アイオノマー系樹脂、アクリロニトリル／ブタジエン／スチレン（ＡＢＳ）樹脂等が使用でき、発泡剤としては、アゾジカルボンアミド等の有機発泡剤や重炭酸ナトリウム等の無機発泡剤が使用できる。この実施形態では、ポリプロピレン系樹脂に発泡剤として重炭酸ナトリウムを適宜添加した発泡樹脂シートを使用している。また、この発泡樹脂基材２１の発泡倍率は、２〜１０倍に設定され、厚みは０．５〜３０ｍｍ、特に１〜１０ｍｍの範囲に設定されている。
【００５７】
次いで、樹脂リブ２２は、発泡樹脂基材２１の裏面側に配設され、特に、図３に示すように、交差状に延びる所定パターンに設定されている。尚、このパターンは、縦横方向、斜め方向、あるいはその組み合わせ等、交差状であれば任意のパターンが選択されて良い。この樹脂リブ２２は、汎用の合成樹脂成形体からなり、通常好ましく使用できる合成樹脂として、ポリエチレン系樹脂、ポリプロピレン系樹脂、ポリスチレン系樹脂、ポリエチレンテレフタレート系樹脂、ポリビニルアルコール系樹脂、塩化ビニル系樹脂、アイオノマー系樹脂、ポリアミド系樹脂、アクリロニトリル／ブタジエン／スチレン（ＡＢＳ）樹脂、ポリカーボネート樹脂等から適宜選択されて良く、本実施形態では、環境面、リサイクル面を考慮してポリプロピレン系樹脂が使用されている。
【００５８】
また、この樹脂リブ２２には、上記熱可塑性樹脂中に適宜フィラー、例えば、ガラス繊維、カーボン繊維等の無機繊維や、タルク、クレイ、シリカ、炭酸カルシウム等の無機粒子等の充填剤が混入されていても良い。
【００５９】
このように、図１乃至図３に示すドアトリム１０は、積層構造体からなるドアトリムアッパー２０と、合成樹脂単体のドアトリムロアとから構成され、外観上のアクセント効果により、優れた外観意匠性を備えている。更にドアトリムアッパー２０は、保形性を有する発泡樹脂基材２１と、発泡樹脂基材２１の裏面に積層一体化される樹脂リブ２２と、加飾性を有する加飾材２３とから構成されているため、従来のように製品の全周に亘り占有していた樹脂芯材を廃止でき、かつ軽量な発泡樹脂基材２１を使用する関係で、製品の重量について、従来例に比し４０％以上の軽量化を図ることができるとともに、樹脂材料も大幅に節約でき、コストダウンにも貢献できる。
【００６０】
更に、発泡樹脂基材２１は、多孔質構造であるため、ドアトリムアッパー２０は、吸音性能に優れ、車室内の騒音を低減することができる。また、発泡樹脂基材２１の吸音性を維持するために、発泡樹脂基材２１の表面に予めラミネートされるか、または成形時に一体化されて積層一体化される加飾材２３は、織布、不織布、編布等の通気性を備えたシート材料が好ましい。尚、加飾材２３は、織布、不織布、編布等の通気性シート以外にも塩ビシートやＴＰＯシート等の合成樹脂シート、合成樹脂フィルム、発泡体、網状体を使用することができる。尚、ＴＰＯシートを使用した場合、オレフィン系樹脂材料で統一できるため、リサイクル面で有利である。
【００６１】
次に、ドアトリム１０におけるドアトリムアッパー２０の外周端末に沿う構造について、図４を基に説明する。すなわち、ドアトリムアッパー２０は、上述したように、保形性を有する軽量な発泡樹脂基材２１の裏面に、剛性を強化する樹脂リブ２２が一体化され、かつ発泡樹脂基材２１の表面には、加飾性を有する加飾材２３が積層一体化されている。更に、ドアトリムアッパー２０の製品外周部に沿って、製品に立体感を現出させるためのフランジ２１１が下向きに形成されるとともに、フロント側縁部は、このフランジ２１１から更に延長部２１２が水平状に延設され、その先端には、薄肉ヒンジ部２４を基に巻込み処理される巻込みシロ２５が設定されている。そして、この巻込みシロ２５は、延長部２１２の裏面に超音波溶着、あるいは熱溶着、接着止め等により固着され、車体パネル１６に対して面当て状態で当接している。
【００６２】
一方、ドアトリムアッパー２０のリヤ側縁部は、延長部２１２が省略され、フランジ２１１の先端に薄肉ヒンジ部２４を基に巻込み処理される巻込みシロ２５が設定されている。そして、ドアトリムアッパー２０のリヤ側縁部は、車体パネル１６に対して上記薄肉ヒンジ部２４が点当て状態で当接している。
【００６３】
従って、ドアトリムアッパー２０の外周縁部に薄肉ヒンジ部２４が該当するため、シャープな外周ラインが確保でき、外観見栄えに優れるとともに、延長部２１２の裏面に巻込みシロ２５が折り返された二重構造となっているため、外周部の剛性が強化でき、波打ち変形等の恐れがなく、車体パネル１６に対してスキなく密着でき、合わせ精度を高めることができるという利点がある。また、相手部品と一定クリアランスを設けた合わせ形状とする場合においても、その合わせ精度を高めることができる。
【００６４】
次に、ドアトリムアッパー２０の外周端末部の端末処理工程を含めたドアトリム１０の製造方法の概要について、以下に説明する。まず、図５で成形金型４０の全体構造について説明し、図６でドアトリムアッパー２０に対応する部位について、図７はドアトリムアッパーにおける外周部に対応するそれぞれ成形金型４０の構成について説明する。
【００６５】
図５において、ドアトリム１０の成形に使用する成形金型４０は、所定ストローク上下動可能な成形上型４１と、成形上型４１と対をなす固定側の成形下型４２と、成形下型４２に接続される２基の射出機４３ａ，４３ｂとから大略構成されている。
【００６６】
更に詳しくは、成形上型４１は、製品形状に合致したキャビティ部４１１が形成されており、成形上型４１の上面に連結された昇降シリンダ４１２により所定ストローク上下駆動される。また、成形上型４１の４隅部には、ガイド機構となるガイドブッシュ４１３が設けられている。
【００６７】
一方、成形下型４２には、成形上型４１のキャビティ部４１１に対応するコア部４２１が設けられている。また、このコア部４２１の型面に溶融樹脂を供給するために、マニホールド４２２ａ，４２２ｂ、ゲート４２３ａ，４２３ｂが設けられており、このマニホールド４２２ａ，４２２ｂ、ゲート４２３ａ，４２３ｂの樹脂通路を経て射出機４３ａ，４３ｂから供給される溶融樹脂Ｍ１，Ｍ２がコア部４２１の上面に形成された溝部４２４内、及びドアトリムロア３０を形成するためのキャビティ内に供給される。
【００６８】
また、成形下型４２の４隅部には、ガイド機構となるガイドポスト４２５が突設され、このガイドポスト４２５は、成形上下型４１，４２が型締めされる際、ガイドブッシュ４１３内に案内されることで成形上型４１のプレス姿勢を適正に維持できる。
【００６９】
図６は、図５に示す成形金型のVI−VI線断面図を示すもので、ドアトリムアッパー２０を構成する発泡樹脂基材２１、樹脂リブ２２、加飾材２３を成形するための成形金型４０は、特に、成形下型４２において、コア部４２１の型面に所定パターン形状の樹脂リブ２２に対応する溝部４２４が設けられている。
【００７０】
また、このドアトリムアッパー２０に対応する部分における成形金型４０においては、特に、図７に示すように、ドアトリムアッパー２０の外周端末の巻込みシロ２５を形成するために、成形上型４１に凸条４１４が形成されており、この凸条４１４が発泡樹脂基材２１に薄肉ヒンジ部２４を形成する。
【００７１】
次いで、図８乃至図１２に基づいて、上述したドアトリム１０の製造方法の各工程について説明する。まず、図８に示すように、ヒーター装置５０により発泡樹脂シートＳの一方面に加飾材２３をラミネートしたものを所定温度に加熱軟化させる。この発泡樹脂シートＳとしては、ポリプロピレン製発泡シート（住化プラステック製、商品名：スミセラー発泡ＰＰシート、発泡倍率＝３倍、厚み３ｍｍ）が使用されている。
【００７２】
続いて、図９に示すように、加熱軟化処理した発泡樹脂シートＳ（加飾材２３をラミネートしている）をドアトリムアッパー２０対応箇所における成形上型４１のキャビティ部４１１と成形下型４２のコア部４２１で画成されるキャビティの上半部分にセットする。
【００７３】
そして、発泡樹脂シートＳをセットした後、成形上型４１の昇降シリンダ４１２が動作して、成形上型４１が所定ストローク下降して、図１０に示すように、成形上下型４１，４２が型締めされて発泡樹脂シートＳが所望の型面形状に沿って賦形され、発泡樹脂基材２１が成形されるとともに、第１の射出機４３ａからマニホールド４２２ａ、ゲート４２３ａを通じてドアトリムアッパー２０における樹脂リブ２２を形成するために、溶融樹脂Ｍ１がコア部４２１の溝部４２４内に射出充填される。
【００７４】
同時に、ドアトリムロア３０を成形するために、第２の射出機４３ｂからマニホールド４２２ｂ、ゲート４２３ｂを通じてキャビティの略下半部分に溶融樹脂Ｍ２が射出充填され、ドアトリムロア３０が所要形状に成形される。
【００７５】
従って、第１の射出機４３ａ、第２の射出機４３ｂからそれぞれ溶融樹脂Ｍ１，Ｍ２をキャビティ内に射出充填することにより、ドアトリムアッパー２０における樹脂リブ２２を所要形状に成形するとともに、これと一体にドアトリムロア３０が成形される。尚、この溶融樹脂Ｍ１，Ｍ２としては、住友ノーブレンＢＵＥ８１Ｅ６（住友化学工業製ポリプロピレン、メルトインデックス＝６５ｇ／１０分）でタルクが適宜割り合いで混入されている。尚、溶融樹脂Ｍ１，Ｍ２の射出のタイミングを成形上下型４１，４２の型締め前に設定しても良い。
【００７６】
このように、ツートンタイプのドアトリム１０を製造するには、成形下型４２に２基の射出機４３ａ，４３ｂを連結して、ドアトリムアッパー２０とドアトリムロア３０とについて、各樹脂通路を通じて溶融樹脂Ｍ１，Ｍ２を射出充填することで、単一の成形金型４０で、かつ工程数が短縮化された形でツートンタイプのドアトリム１０を製造することができる。
【００７７】
そして、上述したドアトリム１０の製造方法において、特に、ドアトリムアッパー２０については、図１１に示すように、成形上型４１と成形下型４２との間で発泡樹脂基材２１及び加飾材２３が所望の曲面形状に成形され、かつ成形下型４２の溝部４２４内に溶融樹脂が射出充填され、樹脂リブ２２を一体成形する際、成形上型４１に形成されている凸条４１４により、発泡樹脂基材２１に薄肉ヒンジ部２４が形成され、その外側部分は、巻込みシロ２５として画定される。
【００７８】
従って、ドアトリムアッパー２０及びドアトリムロア３０の成形完了後、成形上型４１が上昇して型開きが行なわれた後、成形金型４０から成形品を取り出し、次いで、図１２に示すように、ドアトリムアッパー２０における外周端末において、薄肉ヒンジ部２４を折返し基点としてその外周に位置する巻込みシロ２５を発泡樹脂基材２１の裏面に超音波溶着、あるいは熱溶着、または接着止め、機械止め等により固着すれば、図４に示すように、ドアトリムアッパー２０の外周端末は、薄肉ヒンジ部２４が対応し、外周端末の見栄えが良く、かつ二重構造となり、剛性も強化されたドアトリムアッパー２０の端末処理が完了する。尚、この方式では、ドアトリムアッパー２０における樹脂リブ２２の素材とドアトリムロア３０の素材を相違させることができ、それぞれの要求される項目に応じて、材料を適宜変更することができる。
【００７９】
また、ドアトリムアッパー２０とドアトリムロア３０とに分岐して供給される溶融樹脂Ｍ１，Ｍ２を同一素材として、１基の射出機４３から供給することもできる。この場合は、射出機４３と連通するメインのマニホールドからドアトリムアッパー２０側に供給する溶融樹脂Ｍ１の通路となる分岐マニホールドと、ドアトリムロア３０に溶融樹脂Ｍ２を供給する樹脂通路の分岐マニホールドとを設定して行なえば良い。
【００８０】
次いで、図１３乃至図１５は、本発明の第２実施形態を示すもので、この第２実施形態においては、成形金型４０において、成形下型４２のドアトリムアッパー２０対応箇所において押圧機構４４が設けられている。
【００８１】
この押圧機構４４は、押圧ブロック４４１と、駆動シリンダ４４２により構成されており、この押圧機構４４は、成形上型４１に形成されている薄肉ヒンジ部２４を形成するための凸条４１４の直下に位置する。
【００８２】
そして、まず、図１３に示すように、加熱軟化状態にある発泡樹脂シートＳ（表面側に加飾材２３の原反シートがラミネートされている）を成形下型４２の型面上に加熱軟化状態でセットした後、成形上型４１が下降動作すると同時に、押圧機構４４における押圧ブロック４４１が駆動シリンダ４４２の動作により上昇し、この押圧ブロック４４１が成形上型４１の型面に対して発泡樹脂シートＳを押圧することで、発泡樹脂シートＳに薄肉ヒンジ部２４が形成される。
【００８３】
更に、この状態、すなわち、発泡樹脂シートＳの外周部に沿って成形上型４１と押圧ブロック４４１とで挟み込んだ状態で成形上型４１が下降して発泡樹脂基材２１を所望形状に成形すると同時に、駆動シリンダ４４２が収縮動作することで、成形上型４１と連繋して押圧ブロック４４１もそれと連動して下降する（図１４参照）。
【００８４】
そして、成形が完了して、成形上型４１が上昇して型開きが行なわれた後、ドアトリムアッパー２０（図示はしないがドアトリムロア３０と一体化されている）を脱型した後、薄肉ヒンジ部２４を折返し基点として巻込みシロ２５を発泡樹脂基材２１の裏面側に巻込み処理すれば、簡単に端末処理が行なえる。
【００８５】
また、この第２実施形態においては、成形上型４１と成形下型４２との側壁面とのクリアランスを適切位置に設定することで、剛性の強化された剛性強化部２６を設定することができる利点がある。
【００８６】
次いで、図１６乃至図１９は、本発明の第３実施形態を示すもので、図１６，図１７は、第３実施形態に使用する成形金型４０の要部を示す斜視図並びに断面図、図１８は、第３実施形態における端末部の成形工程を示す説明図、図１９は、端末処理工程を示す説明図である。
【００８７】
すなわち、この第３実施形態においては、図１６，図１７に示すように、成形下型４２の外側面に成形金型４０の開閉方向と同一方向の断面において鋸刃形状をなす切削部４５がドアトリムアッパー２０該当部分の外周縁に沿って形成されている。
【００８８】
従って、成形金型４０内に加熱軟化処理を施した発泡樹脂シートＳ（一面に加飾材２３の原反シートがラミネートされている）をセットした後、成形金型４０の型締め時、成形上下型４１，４２のキャビティ形状に沿って発泡樹脂基材２１及び加飾材２３が所望の曲面形状に成形される成形工程において、特にコア部４２１の側壁面に沿って切削部４５が形成されているため、成形上型４１の下降により、この切削部４５と成形上型４１の内面との間で発泡樹脂基材２１が押し切られるように削り取られ、巻込みシロ２５相当箇所（折返しラインＰより下部側）の発泡樹脂基材２１が切削されることで、薄肉状の巻込みシロ２５を簡単に形成できる。次いで、図１８に示すように、加飾材２３と削り取られた後の発泡樹脂の残骸からなる巻込みシロ２５を発泡樹脂基材２１の裏面に巻込み処理すれば良く、この第３実施形態においては、発泡樹脂基材２１の成形と同時に巻込みシロ２５を薄肉状及び可撓性をもつように形成することができ、巻込みシロ２５の巻込み端末処理工程を円滑に行なうことができるという利点がある。
【００８９】
【発明の効果】
以上説明した通り、本発明に係る自動車用内装部品は、軽量でかつ保形性を有する発泡樹脂基材と、この発泡樹脂基材の裏面で、かつ製品の外周縁など、剛性が要求される部位に積層一体化される樹脂リブと、発泡樹脂基材の表面に積層される加飾材とから構成されるため、従来の重量の嵩む樹脂芯材を廃止できることから、軽量で低コスト、しかも多孔質素材であるため、吸音性能に優れた自動車用内装部品を提供できるという効果を有する。
【００９０】
更に、成形金型のキャビティ形状に沿って、発泡樹脂基材を所要形状に成形すると同時に発泡樹脂基材の裏面側に樹脂リブを成形するという工程を採用すれば、樹脂成形体である樹脂リブの投影面積が少ないため、従来の樹脂芯材に比べ、成形金型にかかる負荷も少なく、かつ冷却時間も短縮化でき、歩留まりを高めることができることから、作業能率を高めることができるとともに、大幅なコストダウンを招来できるという作用効果を有する。
【００９１】
また、本発明に係る自動車用内装部品における外周端縁部は、発泡樹脂基材に形成された薄肉ヒンジ部を折返し基点として巻込みシロが発泡樹脂基材裏面に巻込み処理されていることにより、外周端末部は薄肉ヒンジ部が該当するため、シャープな外周ラインが形成でき、外観意匠性に優れるとともに、特に、端末部分においては、折り返した二重構造であるため、剛性が強化されており、波打ち不良等が生じることがなく、かつパネルまたは隣接する相手部品に対する合わせ精度を高めるなどの種々の効果を有する。
【００９２】
更に、本発明方法の別態様として、発泡樹脂基材の成形時に折返し基点を基に外周部の外側部分を成形金型の合わせにより切削処理して薄肉状の巻込みシロを形成する構成を採用すれば、巻込みシロの可撓性を利用して裏面への巻込み処理を円滑に行なえ、端末処理作業を円滑に行なうことができるという効果を有する。
【図面の簡単な説明】
【図１】本発明に係る自動車用内装部品を適用した自動車用ドアトリムの第１実施形態を示す正面図である。
【図２】図１中II−II線断面図である。
【図３】図１に示す自動車用ドアトリムにおけるドアトリムアッパーの樹脂リブとドアトリムロアとを示す正面図である。
【図４】図１中IV−IV線断面図であり、ドアトリムアッパーの外周端末部の構成を示す断面図である。
【図５】図１に示す自動車用ドアトリムを成形する際に使用する成形金型の構成を示す全体図である。
【図６】図５中VI−VI線断面図である。
【図７】図６に示す成形金型の外周部を示す断面図である。
【図８】図１に示す自動車用ドアトリムの製造方法における発泡樹脂シートの予熱工程を示す説明図である。
【図９】図１に示す自動車用ドアトリムの製造方法における発泡樹脂シートのセット工程を示す説明図である。
【図１０】図１に示す自動車用ドアトリムの製造方法における発泡樹脂基材及び樹脂リブの成形工程を示す説明図である。
【図１１】図１に示すドアトリムアッパーにおける薄肉ヒンジ部の形成工程を示す説明図である。
【図１２】図１に示すドアトリムアッパーにおける巻込みシロの端末処理工程を示す説明図である。
【図１３】本発明方法の第２実施形態に使用する成形金型の要部を示す説明図である。
【図１４】図１３に示す成形金型を使用してドアトリムアッパーを成形する工程を示す説明図である。
【図１５】本発明方法の第２実施形態で成形されたドアトリムアッパーの外周部を示す断面図である。
【図１６】本発明方法の第３実施形態に使用する成形金型の要部を示す斜視図である。
【図１７】本発明方法の第３実施形態に使用する成形金型の要部を示す図１６中XVII−XVII線断面図である。
【図１８】図１６に示す成形金型を使用してドアトリムアッパーを成形する工程を示す説明図である。
【図１９】本発明方法の第３実施形態におけるドアトリムアッパーの端末処理工程を示す説明図である。
【図２０】従来の自動車用ドアトリムを示す正面図である。
【図２１】図２０中XXI −XXI 線断面図である。
【図２２】従来の自動車用ドアトリムの成形金型を示す説明図である。
【図２３】プレス成形による自動車用ドアトリムの端末部分の従来例を示す説明図である。
【図２４】表皮巻込みタイプの自動車用ドアトリムにおける端末部分の従来例を示す説明図である。
【符号の説明】
１０ツートンタイプの自動車用ドアトリム
１１インサイドハンドルエスカッション
１２パワーウインドウスイッチエスカッション
１３ポケット用開口
１４ポケットバックカバー
１５スピーカグリル
２０ドアトリムアッパー
２１発泡樹脂基材
２１１フランジ
２１２延長部
２２樹脂リブ
２３加飾材
２４薄肉ヒンジ部
２５巻込みシロ
２６剛性強化部
３０ドアトリムロア
４０成形金型
４１成形上型
４２成形下型
４３ａ，４３ｂ射出機
４４押圧機構
４４１押圧ブロック
４４２駆動シリンダ
４５切削部
５０ヒーター装置
Ｓ発泡樹脂シート
Ｍ１，Ｍ２溶融樹脂
Ｐ折返しライン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to automotive interior parts such as door trims, rear parcel shelves, floor trims, trunk trims, rear side trims, and manufacturing methods thereof, and molding dies. In particular, the present invention is lightweight and has excellent appearance and mechanical strength of an outer peripheral terminal portion. In addition, the present invention relates to an automotive interior part that can be manufactured easily and inexpensively, a method for manufacturing the same, and a molding die.
[0002]
[Prior art]
For example, the configuration of automobile interior parts will be described with reference to FIGS. The door trim 1 has a shape retaining property and a mounting rigidity to a vehicle body panel, and is formed by laminating and integrating a skin 3 excellent in surface appearance on the surface of a resin core material 2 that extends over almost the entire product surface. Yes.
[0003]
The resin core material 2 is made of a polypropylene resin mixed with talc, and the skin 3 does not have shape retention itself, and the back surface of the synthetic resin sheet such as a vinyl chloride sheet is made of polyethylene foam or the like. A laminated sheet material in which a cushion material is laminated is used, and recently, an elastomer sheet such as a TPO (thermoplastic olefin) sheet tends to be frequently used in consideration of environmental aspects and recycling aspects.
[0004]
Next, a conventional example of the method for forming the door trim 1 will be described with reference to FIG. First, a molding die 4 that molds the door trim 1 is connected to a molding upper die 5 that can move up and down by a predetermined stroke, a molding lower die 6 that forms a pair with the molding upper die 5, and a molding lower die 6. It is generally composed of the injection machine 7.
[0005]
When the upper and lower molds 5 and 6 are clamped, a cavity portion 5a is formed in the molded upper mold 5 and a core section 6a is provided in the molded lower mold 6 in order to shape the product shape of the door trim 1. Yes. In order to move the molding upper die 5 up and down by a predetermined stroke, an elevating cylinder 5b is connected, and the molding lower die 6 is provided with a manifold 6b and a gate 6c that serve as a passage of molten resin from the injection machine 7.
[0006]
Further, in order to maintain an appropriate posture, the upper molding die 5 that moves up and down is provided with guide posts 6d at the four corners of the lower molding die 6, and the molding upper die 5 has guides corresponding to the guide posts 6d. A bush 5c is provided.
[0007]
Therefore, when the molding upper and lower molds 5 and 6 are in the mold open state, either the skin 3 is set in the mold, and then either immediately before or after the molding upper and lower molds 5 and 6 are clamped The molten resin M is injected and filled from the injection machine 7 through the manifold 6b and the gate 6c into the product cavity between the molds at the timing, thereby forming the resin core material 2 into a required curved shape and the resin core material 2 The skin 3 is integrally formed on the surface (for example, see Patent Document 1).
[0008]
In FIG. 22, for convenience of explanation, the molten resin M is supplied to the mold surface of the core portion 6 a in an open state, but actually, the molten resin M is injected into the cavity after the mold upper and lower molds 5 and 6 are clamped. It may be filled.
[0009]
Furthermore, as shown in FIG. 23, the outer peripheral terminal of the door trim 1 product is subjected to simultaneous press molding of the skin 3 on the surface of the core material 2, and then pierced in a separate step after molding in the mold or after molding. Cut processing is performed.
[0010]
Also, as shown in FIG. 24, after the core material 2 is press-molded, the skin 3 is integrated by vacuum pressing, press-bonding, etc. in a separate process, and then the terminal 3 a of the skin 3 is wound around the back surface side of the core material 2. Processing is also conventionally performed.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-138268 (Page 2, FIGS. 3 and 4)
[0012]
[Problems to be solved by the invention]
However, in the conventional door trim 1, since the projected area of the resin core material 2 is large, there are problems that the material cost is high and the product is heavy.
[0013]
In addition, since the projected area of the resin core material 2 is large, it is necessary to set the injection pressure at the time of molding high, and a mold structure that can withstand the high injection pressure is required, and the production cost of the mold is increased, In addition, since a large amount of molten resin is cooled and solidified, the molding cycle becomes longer, which is a major factor for reducing productivity.
[0014]
Furthermore, as shown in FIG. 23, the outer peripheral edge of the door trim 1 has the disadvantages that when the outer skin simultaneous press molding is performed, the outer peripheral terminal processing is difficult, the appearance is poor, and the appearance performance is deteriorated. As shown in FIG. 3, the method of winding the skin 3 in a separate process requires a large number of man-hours and inevitably increases costs.
[0015]
The present invention has been made in view of such circumstances, and can provide weight reduction, provide high-rigidity and low-cost interior parts for automobiles, reduce molding die costs, and shorten the molding cycle. In particular, an object of the present invention is to provide an automotive interior part, a manufacturing method thereof, and a molding die that have improved appearance performance by enhancing the appearance and rigidity of a product outer peripheral terminal portion.
[0016]
[Means for Solving the Problems]
As a result of earnest research, the present inventors have given the function as a core material by imparting shape retention to the foamed resin sheet that has been used conventionally as the skin, and more. Resin with excellent rigidity at locations where high rigidity is required, i.e. it can be intimately contacted with the peripheral part of the product, the panel, the mating part with the mating part, or where a certain clearance is secured, or where the part is attached and where the load is applied By arranging ribs, it can be reduced in weight compared to conventional resin cores with a large projected area, and the outer peripheral terminal treatment of products can be done easily and beautifully by simply attaching a winding part to the foamed resin base material. It has been found that terminal processing can be achieved, and the present invention has been completed.
[0017]
That is, the automotive interior part according to the present invention is formed by compressing a foamed resin sheet and is laminated and integrated on the back surface of the foamed resin base material that is lightweight and has shape retention. Resin ribs with a reduced projected area A decorative material laminated and integrated on the surface of the foamed resin substrate; An automotive interior part comprising a thin hinge portion provided on a foamed resin base material on a back surface of the foamed resin base material along a slightly inner side of the outer periphery of the product. It is characterized in that the rigidity of the terminal portion is reinforced by the winding process.
[0018]
Furthermore, another embodiment of the present invention includes a foamed resin base material that is lightweight and has shape retention, a resin rib that is laminated and integrated on the back surface of the foamed resin base material, and a surface of the foamed resin base material. It is an automotive interior part consisting of a decorative material laminated and integrated with the foamed resin base material cut from the folding line set along the inner periphery of the product periphery to the outer peripheral terminal, and has flexibility It is formed as a wrapping sheet, and the wrapping sheet is formed on the back side of the foamed resin base material based on the folding line.
[0019]
Here, the interior parts for automobiles can be applied to door trims, rear parcel shelves, floor trims, luggage trims, trunk trims, rear side trims, and the like.
[0020]
When the foamed resin base material that is lightweight and has shape retention properties is close to a flat shape, the heat softening step is omitted and it is molded into a desired shape by a mold, but when applied to a three-dimensional product After the heat-softening treatment of the foamed resin sheet, the foamed resin sheet is molded into a required curved shape in a molding die, and the shape is maintained. Here, “shape retention” refers to having rigidity enough to retain the shape when the mold is removed after molding, even without a reinforcing material such as a rib. Also, if the product shape includes a high expansion ratio part, after the foamed resin sheet is heat-softened, a vacuum suction mechanism is provided in the molding die and the foamed resin sheet is vacuumed along the inner surface of the molding die. A suction force may be applied.
[0021]
As the foamed resin sheet, a material obtained by adding a foaming agent to a thermoplastic resin is used. The thermoplastic resin may be one type of thermoplastic resin or two or more types of thermoplastic resins. Preferably, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, and the like can be used.
[0022]
As the foaming agent, an organic foaming agent such as an azo compound, a sulfohydrazide compound, a nitroso compound or an azide compound, or an inorganic foaming agent such as sodium bicarbonate can be used.
[0023]
The foamed resin base material obtained by molding the foamed resin sheet into a required shape after heat softening treatment preferably has a foaming ratio of 2 to 10 times in consideration of the balance between the weight and strength of the product. The cell diameter of the foamed resin base material at that time is preferably in the range of 0.1 μm to 2.0 mm, and the thickness is 0.5 to 30 mm, preferably 1 to 10 mm.
[0024]
On the other hand, the thermoplastic resin material used as the resin rib can be appropriately selected from a wide range of thermoplastic resins. Generally, polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, ionomer resin, polyamide resin, acrylonitrile / butadiene / styrene (ABS) can be preferably used. Resin, polycarbonate resin, etc. can be used.
[0025]
Moreover, you may mix various fillers in these thermoplastic resins. Examples of the filler that can be used include inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica, and calcium carbonate. Moreover, various additives, such as antioxidant, a ultraviolet absorber, a coloring agent, a flame retardant, and a low shrinkage agent, may be mix | blended.
[0026]
And as a decorating material laminated and integrated on the surface of the foamed resin base material in order to enhance the appearance design, woven fabrics, non-woven fabrics, knitted fabrics, sheets, films, foams, nets and the like can be used. Although the material which comprises these decorating materials is not specifically limited, It is more preferable to use the raw material which has air permeability, such as a woven fabric, a nonwoven fabric, and a knitted fabric, in order to utilize the sound absorption performance of a foamed resin base material. In addition, when a TPO sheet is used as a decorating material, the material can be unified with an olefin resin, so that the recycling work can be performed smoothly.
[0027]
In addition, the outer peripheral edge of the interior part has a thin hinge part formed on the foamed resin base material that serves as a folding line, and the outer winding wrap around this foamed resin base material on the back side of the foamed resin base material. Has been processed.
[0028]
Further, as another aspect of the terminal treatment, the foamed resin base material in the outer part is scraped off from the folding line, and the outer part from the folding line is formed as a winding part having flexibility of only a decorative material, What is necessary is just to wind a winding part in the back surface side of a foamed resin base material.
[0029]
And according to the interior part for automobiles according to the present invention, the decorative material having the decorating property is laminated on the front surface side of the foamed resin base material having the shape-retaining property, and the resin is meant to reinforce the rigidity on the back surface side. Since the ribs are laminated and integrated, the conventional resin core material can be eliminated. Therefore, by eliminating the conventional resin core material having a very large projected area, the weight of the product can be reduced and the resin material can be saved, so that the material cost can be reduced at the same time.
[0030]
Furthermore, for the outer peripheral part of the interior part, the thin hinge part is folded back and the outer part is wound as a wrapping process, so the cut end is not conspicuous to the outside, the appearance design is excellent, and the terminal part is The foamed resin base material has a double structure, and the rigidity can be enhanced.
[0031]
Furthermore, if a configuration in which the foamed resin base material outside the folding line of the foamed resin base material is scraped off is adopted, the cut end is not conspicuous on the outside, and the configuration includes a wrapping part of only the decorative material. Since it has flexibility, winding work can be performed smoothly.
[0032]
In addition, the porous sound-absorbing function of the foamed resin base material provides interior parts with excellent sound-absorbing performance. When polyolefin resin is used as the material for the foamed resin base material and resin ribs, Since it is unified, the separation process can be abolished and the recycling work can be simplified.
[0033]
Furthermore, the rib thickness of the resin rib can be varied as appropriate, for example, by setting the rib thickness to be thicker at sites where a large external force is applied to the product, and by reducing the rib thickness at sites where external force is relatively difficult to apply. Can do. Therefore, it is sufficient to use the minimum necessary amount of resin material, which can contribute to weight reduction and cost reduction of the product. Moreover, the clip seat or the attachment seat for attaching various escutcheon parts can also be integrally formed in the resin rib.
[0034]
Next, a method for manufacturing an automotive interior part according to the present invention comprises a foamed resin base material that is lightweight and has shape retention, and a resin rib that is laminated and integrated on the back surface of the foamed resin base material. A decorative material laminated and integrated on the surface of the foamed resin substrate; In the manufacturing method of interior parts for automobiles, Laminated with decorative materials The step of setting the foamed resin sheet, the molds are clamped together, and the foamed resin base material is molded into the required shape of the product cavity of the molding die. While forming the thin hinge part along the folding line slightly inside from the periphery, the molten resin is injected and filled into the groove part of the molding lower mold at the timing just before or after the mold clamping. The resin rib is laminated and integrated on the back side of the foamed resin base material, and the integrated process of the foamed resin base material and the resin rib, and the integrated laminated product is removed from the mold after the mold is opened and rolled up. And a terminal treatment process for interior parts which are folded and fixed to the back surface of the foamed resin base material based on the thin hinge portion.
[0035]
Here, the molding die used in the method of the present invention is connected to a molding upper mold that can move up and down by a predetermined stroke, a molding lower mold that is a fixed side located below the molding upper mold, and a molding lower mold. It consists of an injection machine.
[0036]
The molten resin supplied from the injection machine is supplied to the mold surface of the molded lower mold through a resin passage such as a manifold and a gate provided in the molded lower mold, and more specifically, into a groove formed on the mold surface of the molded lower mold. However, after the upper mold is lowered to the bottom dead center and the upper and lower molds are clamped, the molten resin may be injected and filled into the groove provided on the mold surface of the lower mold with a predetermined injection pressure. Although it is good, it may be performed before mold clamping as the injection filling timing of the molten resin.
[0037]
Furthermore, the mold surface of the molded upper and lower molds is set to a desired curved surface shape that matches the product shape. However, in consideration of the winding process of the outer peripheral terminal portion, a protrusion is formed on either side of the molded upper and lower molds. A thin-walled hinge portion is provided on the foamed resin base material, which is provided and serves as a folding base point of the entrainment white.
[0038]
Therefore, by molding the upper and lower molds, the foamed resin sheet is molded into a desired curved surface shape along the mold surface shape of the molding die, and a thin hinge portion is formed slightly inside along the outer peripheral edge. become. Furthermore, the resin rib is laminated and integrated on the back surface of the foamed resin base material by injection filling the molten resin.
[0039]
When the product shape is set to a three-dimensional shape, the foamed resin sheet is set in a molding die after performing heat softening treatment with a heater or the like in all steps.
[0040]
Furthermore, after supplying the heat-softened foamed resin sheet into the molding die, the molded die is clamped to obtain a foamed resin base material having a shape-retaining property, and this foamed resin. In the base material, a thin hinge portion serving as a folding base point is formed during the folding process of the winding white.
[0041]
And simultaneously with shaping | molding of a foamed resin base material, what is necessary is just to laminate | stack and integrate a resin rib on the back surface of a foamed resin base material. In the case where the final product shape has a high development rate portion, it is preferable to perform mold clamping of the molding die a plurality of times and perform injection filling of the molten resin in the final mold clamping process. In addition, if the product shape includes a portion with a higher development ratio, a vacuum suction mechanism is provided in the molding upper mold, and the foamed resin base material is molded into the required shape by the vacuum suction force along the mold surface of the molding upper mold. Good to do.
[0042]
Therefore, according to the method of the present invention, since only the resin rib is molded as compared with the conventional resin core material having a large projected area, the injection pressure can be set lower than the conventional one, so that the load on the molding die can be reduced. At the same time, the amount of resin is small, material costs can be saved, and the cooling time is shorter than that of conventional resin cores, so that the product molding cycle can be shortened.
[0043]
Furthermore, as the terminal processing step, the laminated molded body in which the decorating material, the foamed resin base material, and the resin rib are integrated is taken out from the molding die, and the outer periphery with the thin hinge portion provided on the foamed resin base material as the turning base point. It is only necessary to fold and fix the winding roll along the back of the foamed resin base material, and since the outer peripheral edge of the product corresponds to the thin-walled hinge part, a sharp outer peripheral line can be secured and the terminal part has a double structure The rigidity can be strengthened and there is no fear of deformation.
[0044]
Next, as another embodiment of the method of the present invention, in the step of integrating the foamed resin base material and the resin rib, the molding dies are clamped to form the foamed resin base material in the product cavity shape of the molding die. Molding, injection and filling of molten resin into the groove of the molding lower mold at the timing just before or after the mold clamping, and the resin rib is laminated and integrated on the back side of the foamed resin substrate On the other hand, a pressing mechanism is provided along the part to be wound in the outer periphery of the molding lower mold, and the pressing block in the pressing mechanism is driven up and down by the driving cylinder, and slightly inward from the outer peripheral edge of the foamed resin base material A thin-walled hinge portion is formed as a folding base point of the winding white.
[0045]
Here, the molding die used in the method is a lightweight and shape-retaining foamed resin base material, a resin rib laminated and integrated on the back surface of the foamed resin base material, and the foamed resin base material A molding die that molds an automotive interior part composed of a decorative material laminated on the surface of the molding die, the molding die is a mold upper mold and a mold lower mold capable of mutual clamping and mold opening, It is composed of an injection machine that is connected to the lower mold and supplies molten resin that is the material of the resin rib, and the product cavity between the upper and lower molds is set to a shape that matches the product shape of the foamed resin base material In addition, a groove portion corresponding to the resin rib is provided on the core portion mold surface of the molded lower mold, and a thin hinge portion that serves as a folding base point of the rolled-up resin base is provided along the outer peripheral edge portion of the molded lower mold. The press mechanism for forming is arrange | positioned, It is characterized by the above-mentioned.
[0046]
Further, as another embodiment of the method of the present invention, a foamed resin base material that is lightweight and has shape retention, a resin rib laminated and integrated on the back surface of the foamed resin base material, and the foamed resin base In the manufacturing method of interior parts for automobiles, which are made of decorative materials laminated on the surface of the material, in the mold Laminated with decorative materials Set the foamed resin sheet and mold the foamed resin substrate along the shape of the product cavity of the molded mold by clamping the molds together. The saw blade shape formed on the wall surface of the lower mold along the part is used to scrape off the foamed resin base material corresponding to the entrainment scissors, either at the timing immediately before or after the mold clamping. The molten resin is injected and filled into the groove of the lower mold, and the resin rib is laminated and integrated on the back side of the foamed resin base material. It consists of a terminal treatment process for interior parts that removes the integrated foamed resin base material and folds and fixes the thin-walled flexible winding scissors on the back of the foamed resin base material. It is characterized by that.
[0047]
The molding die used for this is a lightweight and shape-retaining foamed resin base material, a resin rib laminated and integrated on the back surface of the foamed resin base material, and the surface of the foamed resin base material A molding die for molding automotive interior parts composed of decorative materials laminated on the mold, the molding die comprising a mold upper mold and a mold lower mold capable of mutual clamping and mold opening, and a mold lower mold An injection machine that is connected to a mold and supplies molten resin that is a material of resin ribs, and a saw for cutting the winding periphery of the outer peripheral edge of the foamed resin base material on the outer peripheral surface of the lower mold A blade-shaped cutting part is set.
[0048]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of an automobile interior part, a manufacturing method thereof, and a molding die according to the present invention will be described by exemplifying an automobile door trim and a manufacturing method thereof.
[0049]
FIG. 1 to FIG. 12 show a first embodiment of the present invention, FIG. 1 is a front view showing a two-tone type automobile door trim, FIG. 2 is a sectional view showing the configuration of the automobile door trim, and FIG. FIG. 4 is a sectional view showing the structure of the outer periphery of the door trim upper in the door trim for the automobile, and FIGS. 5 to 7 are used in the method for manufacturing the door trim for the automobile. FIG. 5 is an overall view of the molding die, FIG. 6 is a sectional view showing a door trim upper forming portion in the molding die, and FIG. 7 is an enlarged sectional view of an outer peripheral portion in the door trim upper forming portion. . Further, FIGS. 8 to 12 show the respective steps of the manufacturing method of the automobile door trim, FIG. 8 is a preheating step of the foamed resin sheet, FIG. 9 is a step of setting the foamed resin sheet to the molding die, and FIG. 10 is the door trim. FIG. 11 is an explanatory view showing the step of forming the winding white, and FIG. 12 is an explanatory view showing the terminal processing step of the winding white.
[0050]
FIGS. 13 to 15 show a second embodiment of the present invention. FIGS. 13 and 14 are explanatory views showing the process of forming a winding sill on the outer peripheral edge of the door trim upper, and FIG. 15 shows the winding. It is explanatory drawing which shows the terminal processing process of white. FIGS. 16 to 19 show a third embodiment of the present invention. FIGS. 16 and 17 are a perspective view and a sectional view showing a main part of a molding die used in the third embodiment, and FIG. FIG. 19 is an explanatory view showing a terminal process step of a winding sill. FIG. 19 is an explanatory view of forming a winding part using a molding die.
[0051]
First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2, a two-tone type automobile door trim 10 is composed of an upper and lower divided part of a door trim upper 20 made of a laminated structure and a door trim lower 30 made of a single resin product.
[0052]
As functional parts to be mounted on the door trim 10, an inside handle escutcheon 11 and a power window switch escutcheon 12 are attached to the door trim upper 20. The door trim lower 30 is provided with a door pocket opening 13, and on the back side thereof, as shown in FIG. 2, a pocket back cover (made of a resin molded body) 14 is attached. The speaker grill 15 is formed integrally or separately on the side.
[0053]
By the way, the door trim 10 for automobiles according to the present invention is applied to the structure of the door trim upper 20 which is a laminated structure to reduce the weight of the product, improve the appearance of the outer peripheral terminal portion, and form the molding process, terminal It is characterized by a simplified processing process.
[0054]
That is, as shown in FIG. 2, the door trim upper 20 is molded into a desired curved surface shape and has a foamed resin base material 21 having shape retention, and a resin laminated and integrated on the back surface side of the foamed resin base material 21. The rib 22 and the decorating material 23 having a decorating function laminated and integrated on the surface side of the foamed resin base material 21 are roughly configured. In the figure, reference numeral 16 denotes a vehicle body panel.
[0055]
In addition, the foamed resin base material 21 is heat-softened to heat the foamed resin sheet so as to have shape retention, and then thermoformed into a required shape, for example, cold press-molded with a molding die having a desired mold surface. In addition, the foamed resin base material 21 may be shaped by vacuum forming for a portion with a higher development rate. In addition, in flat parts like lid parts, such as a jack lid, it can shape | mold into a flat shape, without performing a heat softening process to a foamed resin sheet.
[0056]
The foamed resin sheet has a structure in which a foaming agent is added to a general-purpose thermoplastic resin. The thermoplastic resin includes a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyethylene terephthalate resin, a polyvinyl alcohol resin, a chloride resin. Vinyl resin, ionomer resin, acrylonitrile / butadiene / styrene (ABS) resin, and the like can be used. As the foaming agent, an organic foaming agent such as azodicarbonamide and an inorganic foaming agent such as sodium bicarbonate can be used. In this embodiment, a foamed resin sheet in which sodium bicarbonate is appropriately added as a foaming agent to a polypropylene resin is used. The expansion ratio of the foamed resin base material 21 is set to 2 to 10 times, and the thickness is set to a range of 0.5 to 30 mm, particularly 1 to 10 mm.
[0057]
Next, the resin ribs 22 are disposed on the back surface side of the foamed resin base material 21 and, in particular, are set in a predetermined pattern extending in an intersecting manner as shown in FIG. In addition, as for this pattern, arbitrary patterns may be selected as long as it is intersecting, such as a vertical and horizontal direction, an oblique direction, or a combination thereof. The resin rib 22 is made of a general-purpose synthetic resin molded body, and as a synthetic resin that can be preferably used normally, a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyethylene terephthalate resin, a polyvinyl alcohol resin, a vinyl chloride resin, It may be appropriately selected from ionomer resins, polyamide resins, acrylonitrile / butadiene / styrene (ABS) resins, polycarbonate resins, etc. In this embodiment, polypropylene resins are used in consideration of environmental and recycling aspects. .
[0058]
The resin rib 22 is appropriately mixed with a filler such as inorganic fibers such as glass fiber and carbon fiber, and inorganic particles such as talc, clay, silica and calcium carbonate in the thermoplastic resin. May be.
[0059]
As described above, the door trim 10 shown in FIGS. 1 to 3 includes the door trim upper 20 made of a laminated structure and the door trim lower made of a single synthetic resin, and has an excellent appearance design due to an accent effect on the appearance. ing. Further, the door trim upper 20 includes a foamed resin base material 21 having shape retention, a resin rib 22 laminated and integrated on the back surface of the foamed resin base material 21, and a decorating material 23 having a decorating property. Therefore, the resin core material occupied over the entire circumference of the product can be abolished as in the past, and the weight of the product is 40% compared to the conventional example because the lightweight foamed resin base material 21 is used. The weight can be reduced as described above, and the resin material can be greatly saved, thereby contributing to cost reduction.
[0060]
Furthermore, since the foamed resin base material 21 has a porous structure, the door trim upper 20 is excellent in sound absorption performance and can reduce noise in the vehicle interior. Moreover, in order to maintain the sound absorption of the foamed resin base material 21, the decorative material 23 laminated in advance on the surface of the foamed resin base material 21 or integrated and laminated at the time of molding is a woven fabric. Sheet materials having air permeability such as nonwoven fabric and knitted fabric are preferred. In addition to the breathable sheet such as a woven fabric, a nonwoven fabric, and a knitted fabric, the decorative material 23 may be a synthetic resin sheet such as a vinyl chloride sheet or a TPO sheet, a synthetic resin film, a foam, or a net-like body. In addition, when a TPO sheet is used, since it can unify with an olefin resin material, it is advantageous in terms of recycling.
[0061]
Next, the structure along the outer peripheral terminal of the door trim upper 20 in the door trim 10 will be described based on FIG. That is, as described above, the door trim upper 20 is integrated with the resin ribs 22 that reinforce the rigidity on the back surface of the lightweight foamed resin base material 21 having shape retention, and on the surface of the foamed resin base material 21. The decorative material 23 having a decorative property is laminated and integrated. Further, a flange 211 is formed downward along the product outer periphery of the door trim upper 20 so that the product has a three-dimensional effect, and the front side edge is further extended from the flange 211 with an extension 212 in a horizontal shape. A winding scissor 25 is set at the front end of the coil. The entrainment scissors 25 are fixed to the back surface of the extension portion 212 by ultrasonic welding, heat welding, adhesive bonding, or the like, and are in contact with the vehicle body panel 16 in a face-contact state.
[0062]
On the other hand, at the rear side edge of the door trim upper 20, the extension 212 is omitted, and a winding scissor 25 that is wound based on the thin hinge portion 24 is set at the tip of the flange 211. The rear edge of the door trim upper 20 is in contact with the vehicle body panel 16 with the thin hinge portion 24 in a pointed state.
[0063]
Therefore, since the thin hinge portion 24 corresponds to the outer peripheral edge portion of the door trim upper 20, a sharp outer peripheral line can be secured, the appearance is excellent, and a double structure in which the winding white 25 is folded back on the back surface of the extension portion 212. Therefore, there is an advantage that the rigidity of the outer peripheral portion can be strengthened, there is no fear of undulation deformation, and it can be tightly adhered to the vehicle body panel 16 and the alignment accuracy can be increased. Further, even when the mating shape is provided with a certain clearance with the counterpart part, the mating accuracy can be increased.
[0064]
Next, the outline | summary of the manufacturing method of the door trim 10 including the terminal processing process of the outer periphery terminal part of the door trim upper 20 is demonstrated below. First, the overall structure of the molding die 40 will be described with reference to FIG. 5, the portion corresponding to the door trim upper 20 will be described with reference to FIG. 6, and the configuration of the molding die 40 corresponding to the outer peripheral portion of the door trim upper will be described with reference to FIG.
[0065]
In FIG. 5, a molding die 40 used for molding the door trim 10 includes a molding upper mold 41 that can move up and down by a predetermined stroke, a molding lower mold 42 that is paired with the molding upper mold 41, and a molding lower mold 42. It consists of two injection machines 43a and 43b connected to each other.
[0066]
More specifically, the molding upper die 41 has a cavity portion 411 that matches the product shape, and is driven up and down by a predetermined stroke by an elevating cylinder 412 connected to the upper surface of the molding upper die 41. In addition, guide bushes 413 serving as a guide mechanism are provided at the four corners of the molding upper die 41.
[0067]
On the other hand, the molding lower die 42 is provided with a core portion 421 corresponding to the cavity portion 411 of the molding upper die 41. In addition, manifolds 422a and 422b and gates 423a and 423b are provided to supply molten resin to the mold surface of the core portion 421, and the injection machine passes through the resin passages of the manifolds 422a and 422b and gates 423a and 423b. The molten resins M1 and M2 supplied from 43a and 43b are supplied into a groove 424 formed on the upper surface of the core 421 and into a cavity for forming the door trim lower 30.
[0068]
In addition, guide posts 425 that serve as a guide mechanism protrude from the four corners of the molded lower mold 42, and the guide posts 425 are guided into the guide bush 413 when the molded upper and lower molds 41 and 42 are clamped. As a result, the pressing posture of the molding upper die 41 can be properly maintained.
[0069]
FIG. 6 is a sectional view taken along the line VI-VI of the molding die shown in FIG. 5, and is a molding die for molding the foamed resin base material 21, the resin rib 22, and the decorating material 23 that constitute the door trim upper 20. In particular, the mold 40 is provided with a groove portion 424 corresponding to the resin rib 22 having a predetermined pattern shape on the mold surface of the core portion 421 in the lower molding die 42.
[0070]
Further, in the molding die 40 corresponding to the door trim upper 20, in particular, as shown in FIG. 7, the molding upper die 41 is protruded to form the winding sill 25 of the outer peripheral end of the door trim upper 20. A strip 414 is formed, and the convex strip 414 forms a thin hinge portion 24 on the foamed resin base material 21.
[0071]
Next, each step of the method for manufacturing the door trim 10 described above will be described with reference to FIGS. First, as shown in FIG. 8, the heater device 50 heats and softens the laminate of the decorating material 23 on one surface of the foamed resin sheet S to a predetermined temperature. As the foamed resin sheet S, a polypropylene foam sheet (manufactured by Sumika Plustech, trade name: Sumiceller foam PP sheet, expansion ratio = 3 times, thickness 3 mm) is used.
[0072]
Subsequently, as shown in FIG. 9, the heat-softened foamed resin sheet S (with the decorative material 23 laminated) is formed between the cavity portion 411 of the molding upper mold 41 and the molding lower mold 42 at locations corresponding to the door trim upper 20. Set in the upper half of the cavity defined by the core part 421.
[0073]
Then, after setting the foamed resin sheet S, the lifting cylinder 412 of the molding upper die 41 is operated, the molding upper die 41 is lowered by a predetermined stroke, and the molding upper and lower dies 41 and 42 are molds as shown in FIG. The foamed resin sheet S is shaped along the desired mold surface shape to form the foamed resin base material 21 and the resin ribs in the door trim upper 20 from the first injection machine 43a through the manifold 422a and the gate 423a. In order to form 22, molten resin M <b> 1 is injected and filled into the groove portion 424 of the core portion 421.
[0074]
At the same time, in order to mold the door trim lower 30, the molten resin M2 is injected and filled into the substantially lower half of the cavity from the second injector 43b through the manifold 422b and the gate 423b, and the door trim lower 30 is molded into a required shape.
[0075]
Therefore, the resin ribs 22 in the door trim upper 20 are molded into a required shape by injecting and filling the molten resins M1 and M2 into the cavities from the first injection machine 43a and the second injection machine 43b, respectively. A door trim lower 30 is formed. As the molten resins M1 and M2, talc is mixed in an appropriate proportion with Sumitomo Noblen BUE81E6 (polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g / 10 min). The injection timing of the molten resins M1 and M2 may be set before the mold upper and lower molds 41 and 42 are clamped.
[0076]
Thus, in order to manufacture the two-tone type door trim 10, two injection machines 43 a and 43 b are connected to the molding lower mold 42, and the molten resin M <b> 1 passes through each resin passage for the door trim upper 20 and the door trim lower 30. , M2 can be injection-filled to produce a two-tone door trim 10 with a single molding die 40 and a reduced number of processes.
[0077]
And in the manufacturing method of the door trim 10 mentioned above, especially about the door trim upper 20, as shown in FIG. 11, the foaming resin base material 21 and the decorating material 23 are between the shaping | molding upper mold | type 41 and the shaping | molding lower mold | type 42. When the resin rib 22 is integrally formed by injection molding and filling the resin rib 22 into the groove portion 424 of the lower molding die 42, the foamed resin is formed by the convex strip 414 formed on the upper molding die 41. A thin-walled hinge portion 24 is formed on the base material 21, and an outer portion thereof is defined as a winding white 25.
[0078]
Therefore, after the molding of the door trim upper 20 and the door trim lower 30 is completed, the molding upper die 41 is raised and the mold is opened, and then the molded product is taken out from the molding die 40. Then, as shown in FIG. At the outer peripheral terminal of the upper 20, the winding scissors 25 positioned on the outer periphery of the thin hinge portion 24 are fixed to the back surface of the foamed resin base material 21 by ultrasonic welding, thermal welding, adhesive fixing, mechanical fixing or the like. In this case, as shown in FIG. 4, the outer peripheral terminal of the door trim upper 20 corresponds to the thin hinge portion 24, the outer peripheral terminal has a good appearance, has a double structure, and the rigidity is enhanced. Is completed. In this method, the material of the resin rib 22 in the door trim upper 20 and the material of the door trim lower 30 can be made different, and the material can be appropriately changed according to each required item.
[0079]
Further, the molten resins M1 and M2 branched and supplied to the door trim upper 20 and the door trim lower 30 can be supplied from one injection machine 43 as the same material. In this case, a branch manifold serving as a passage for the molten resin M1 supplied to the door trim upper 20 side from a main manifold communicating with the injection machine 43 and a branch manifold serving as a resin passage for supplying the molten resin M2 to the door trim lower 30 are set. You can do it.
[0080]
Next, FIGS. 13 to 15 show a second embodiment of the present invention. In the second embodiment, in the molding die 40, the pressing mechanism 44 is provided at a location corresponding to the door trim upper 20 of the molding lower die 42. Is provided.
[0081]
The pressing mechanism 44 includes a pressing block 441 and a drive cylinder 442, and the pressing mechanism 44 is directly below the ridge 414 for forming the thin hinge portion 24 formed on the molding upper die 41. To position.
[0082]
First, as shown in FIG. 13, the foamed resin sheet S in a heat-softened state (the raw sheet of the decorating material 23 is laminated on the surface side) is heat-softened on the mold surface of the molding lower mold 42. After setting in the state, the upper molding die 41 is lowered, and at the same time, the pressing block 441 in the pressing mechanism 44 is raised by the operation of the drive cylinder 442, and the pressing block 441 is foamed resin with respect to the mold surface of the molding upper die 41. By pressing the sheet S, the thin hinge 24 is formed in the foamed resin sheet S.
[0083]
Furthermore, when the molding upper die 41 descends in this state, that is, between the molding upper die 41 and the pressing block 441 along the outer peripheral portion of the foamed resin sheet S, the foamed resin base material 21 is molded into a desired shape. At the same time, the drive cylinder 442 is contracted, so that the pressing block 441 is linked with the upper molding die 41 and is moved downward (see FIG. 14).
[0084]
After the molding is completed and the upper mold 41 is raised and the mold is opened, the door trim upper 20 (integrated with the door trim lower 30 (not shown)) is removed, and then the thin hinge If the winding white 25 is wound on the back side of the foamed resin base material 21 with the portion 24 as a turning base point, the terminal processing can be easily performed.
[0085]
In the second embodiment, the rigidity reinforcing portion 26 with enhanced rigidity can be set by setting the clearance between the side wall surfaces of the upper molding die 41 and the lower molding die 42 to an appropriate position. There are advantages.
[0086]
Next, FIGS. 16 to 19 show a third embodiment of the present invention. FIGS. 16 and 17 are a perspective view and a cross-sectional view showing a main part of a molding die 40 used in the third embodiment. FIG. 18 is an explanatory view showing the molding process of the terminal portion in the third embodiment, and FIG. 19 is an explanatory view showing the terminal processing process.
[0087]
That is, in the third embodiment, as shown in FIGS. 16 and 17, a cutting portion 45 having a saw blade shape in a cross section in the same direction as the opening and closing direction of the molding die 40 is formed on the outer surface of the molding lower mold 42. The door trim upper 20 is formed along the outer peripheral edge of the corresponding portion.
[0088]
Therefore, after setting the foamed resin sheet S (the raw sheet of the decorating material 23 is laminated on one side) in the molding die 40, molding is performed when the molding die 40 is clamped. In the molding process in which the foamed resin base material 21 and the decorating material 23 are molded into a desired curved shape along the cavity shape of the upper and lower molds 41, 42, the cutting portion 45 is formed particularly along the side wall surface of the core portion 421. Therefore, the foamed resin base material 21 is scraped off by the lowering of the molding upper die 41 so that the foamed resin base material 21 is pushed between the cutting portion 45 and the inner surface of the molding upper die 41. By cutting the lower part of the foamed resin base material 21, the thin-walled winding scissors 25 can be easily formed. Next, as shown in FIG. 18, a winding white 25 made of the decorating material 23 and the residue of the foamed resin after being scraped off may be wound on the back surface of the foamed resin base material 21, and this third embodiment. , The winding scissors 25 can be formed so as to have a thin shape and flexibility simultaneously with the molding of the foamed resin base material 21, and the winding terminal processing step of the curling scissors 25 can be performed smoothly. There is an advantage.
[0089]
【The invention's effect】
As described above, the automobile interior part according to the present invention is required to have rigidity such as a lightweight and shape-retaining foamed resin base material, a back surface of the foamed resin base material, and an outer peripheral edge of the product. Because it is composed of resin ribs that are laminated and integrated on the part and a decorative material that is laminated on the surface of the foamed resin base material, the conventional heavy resin core material can be abolished. Since it is a porous material, it has the effect that the interior component for motor vehicles excellent in sound absorption performance can be provided.
[0090]
Furthermore, if the process of molding the resin foam on the back side of the foamed resin base material at the same time as molding the foamed resin base material into the required shape along the cavity shape of the molding die, the resin rib that is a resin molded body Compared to conventional resin core materials, the projected area is less, the load on the mold is less, the cooling time can be shortened, and the yield can be increased. This has the effect of reducing the cost.
[0091]
Moreover, the outer periphery edge part in the interior part for automobiles according to the present invention is obtained by winding the wrapping around the back surface of the foamed resin base material with the thin hinge portion formed on the foamed resin base material as the turning base point. , Since the outer peripheral end corresponds to a thin hinge, a sharp outer peripheral line can be formed, and the appearance design is excellent. Especially, the terminal has a folded double structure, so the rigidity is enhanced. In addition, there are various effects such as the occurrence of undulation failure and the like, and the improvement of the alignment accuracy with respect to the panel or the adjacent counterpart component.
[0092]
Furthermore, as another aspect of the method of the present invention, a configuration is adopted in which the outer portion of the outer peripheral portion is cut by fitting a molding die based on the folding base point during molding of the foamed resin base material to form a thin-walled wrapping sheet. If it does so, it has the effect that the winding process to a back surface can be performed smoothly using the flexibility of winding roll, and a terminal processing work can be performed smoothly.
[Brief description of the drawings]
FIG. 1 is a front view showing a first embodiment of an automotive door trim to which an automotive interior part according to the present invention is applied.
2 is a cross-sectional view taken along line II-II in FIG.
3 is a front view showing a resin rib and a door trim lower of a door trim upper in the automobile door trim shown in FIG. 1. FIG.
4 is a cross-sectional view taken along line IV-IV in FIG. 1, and is a cross-sectional view showing a configuration of an outer peripheral terminal portion of the door trim upper.
5 is an overall view showing the configuration of a molding die used when molding the automobile door trim shown in FIG. 1; FIG.
6 is a cross-sectional view taken along line VI-VI in FIG.
7 is a cross-sectional view showing an outer peripheral portion of the molding die shown in FIG. 6. FIG.
FIG. 8 is an explanatory view showing a preheating step of the foamed resin sheet in the method for manufacturing the automobile door trim shown in FIG. 1;
FIG. 9 is an explanatory view showing a foamed resin sheet setting step in the method for manufacturing the automobile door trim shown in FIG. 1;
10 is an explanatory view showing a molding step of a foamed resin base material and resin ribs in the method for manufacturing the automobile door trim shown in FIG. 1. FIG.
FIG. 11 is an explanatory view showing a process of forming a thin hinge portion in the door trim upper shown in FIG. 1;
12 is an explanatory view showing a terminal process step of a winding white in the door trim upper shown in FIG. 1. FIG.
FIG. 13 is an explanatory view showing a main part of a molding die used in the second embodiment of the method of the present invention.
14 is an explanatory view showing a process of forming a door trim upper using the molding die shown in FIG. 13; FIG.
FIG. 15 is a cross-sectional view showing an outer peripheral portion of a door trim upper formed by a second embodiment of the method of the present invention.
FIG. 16 is a perspective view showing a main part of a molding die used in a third embodiment of the method of the present invention.
17 is a cross-sectional view taken along the line XVII-XVII in FIG. 16, showing the main part of the molding die used in the third embodiment of the method of the present invention.
18 is an explanatory view showing a process of forming a door trim upper using the molding die shown in FIG. 16. FIG.
FIG. 19 is an explanatory view showing a terminal processing step of the door trim upper in the third embodiment of the method of the present invention.
FIG. 20 is a front view showing a conventional automobile door trim.
21 is a cross-sectional view taken along line XXI-XXI in FIG.
FIG. 22 is an explanatory view showing a molding die for a conventional automobile door trim.
FIG. 23 is an explanatory view showing a conventional example of a terminal portion of an automobile door trim by press molding.
FIG. 24 is an explanatory view showing a conventional example of a terminal portion in an automobile door trim of a skin entrainment type.
[Explanation of symbols]
10 Two-tone type automotive door trim
11 Inside handle escutcheon
12 Power window switch escutcheon
13 Pocket opening
14 Pocket back cover
15 Speaker grill
20 Door trim upper
21 Foamed resin substrate
211 flange
212 Extension
22 resin ribs
Decorative material
24 Thin hinge
25 wrapping white
26 Stiffening part
30 Door trim lower
40 Mold
41 Upper mold
42 Molded lower mold
43a, 43b Injection machine
44 Pressing mechanism
441 Pressing block
442 Drive cylinder
45 Cutting part
50 Heater device
S Foamed resin sheet
M1, M2 molten resin
P Folding line

Claims

A foamed resin base material (21) that is formed by compressing the foamed resin sheet (S), has a lightweight and shape-retaining property, and a projected area that is laminated and integrated on the back surface of the foamed resin base material (21). An automotive interior part (20) comprising a reduced resin rib (22) and a decorative material (23) laminated and integrated on the surface of the foamed resin base material (21) , Slightly along the inner side, the winding scissors (25) on the outer periphery of the thin hinge portion (24) are formed on the foam resin base material (21) based on the thin hinge portion (24) provided on the foam resin base material (21). An interior part for an automobile, characterized in that the rigidity of the terminal portion is reinforced by winding on the back surface.

A foamed resin base material (21) that is lightweight and has shape retention, a resin rib (22) laminated and integrated on the back surface of the foamed resin base material (21), and the foamed resin base material (21) In the manufacturing method of the interior part (20) for an automobile comprising the decorative material (23) laminated and integrated on the surface ,
A step of setting the foamed resin sheet (S) to set the foamed resin sheet (S) formed by laminating the decorating material (23 ) in the molding die (41, 42);
The molding dies (41, 42) are clamped together, the foamed resin base material (21) is molded into a required shape into the product cavity shape of the molding dies (41, 42), and the foamed resin base material (21). The thin hinge part (24) is formed along the folding line (P) on the inner side slightly from the outer peripheral edge of the mold, while molding is performed either before or after the mold clamping of the molding dies (41, 42). Foamed resin base material (21) and resin in which molten resin is injected and filled into the groove (424) of the lower mold (42), and the resin rib (22) is laminated and integrated on the back side of the foamed resin base material (21). An integration step of the rib (22);
The integrated laminated product is demolded after the molds (41, 42) are opened, and the wrapping white (25) is placed on the back surface of the foamed resin substrate (21) based on the thin hinge portion (24). A terminal treatment process of the interior part (20) to be folded and fixed;
A method for producing an interior part for an automobile, comprising:

In the step of integrating the foamed resin base material (21) and the resin rib (22), the molding dies (41, 42) are clamped together to form the foamed resin into the product cavity shape of the molding dies (41, 42). The base material (21) is molded, and molten resin is injected and filled into the groove (424) of the molded lower mold (42) either before or after the molds (41, 42) are clamped. Then, while the resin rib (22) is laminated and integrated on the back surface side of the foamed resin base material (21), the pressing mechanism (44) along the part to be wound in the outer periphery of the molded lower mold (42). The pressing block (441) in the pressing mechanism (44) is driven up and down by the drive cylinder (442), and the winding block (25) of the winding resin (25) is moved slightly inward from the outer peripheral edge of the foamed resin base material (21). A thin hinge (24) is formed as a turning base. Automobile interior part manufacturing method according to claim 2, characterized in that it is.

When the thin hinge part (24) is formed on the foamed resin base material (21) by the pressing mechanism (44), the foamed resin base material (21) sets the mold clearance of the molded upper and lower molds (41, 42) to be narrow. The manufacturing method of the interior component for automobiles according to claim 3, wherein the rigidity reinforcing portion (26) for supporting the terminal portion is formed.

A foamed resin base material (21) that is lightweight and has shape retention, a resin rib (22) laminated and integrated on the back surface of the foamed resin base material (21), and the foamed resin base material (21) In the manufacturing method of the automotive interior part (20) comprising the decorative material (23) laminated on the surface,
A foaming resin sheet setting step for setting the foaming resin sheet (S) formed by laminating the decorating material (23) in the molding die (41, 42);
The molds (41, 42) are clamped together to form the foamed resin base material (21) along the product cavity shape of the molds (41, 42), and the product of the foamed resin base material (21) The foamed resin base material (21) corresponding to the entrainment scissors (25) is scraped off along the edge portion by the saw blade shape formed on the wall surface of the molding lower mold (42), and the molding dies (41, 42) are obtained. The molten resin is injected and filled into the groove (424) of the molded lower mold (42) at any timing immediately before or after the mold clamping, and the resin rib (22) is made into the foamed resin base material (21). A step of integrating the foamed resin base material (21) and the resin rib (22) to be laminated and integrated on the back side of
The foamed resin base material (21) in which the resin ribs (22) are integrated is removed from the molding die (41, 42), and the foamed resin base material (21) is scraped off. A terminal treatment step of the interior part (20) for folding back and fixing the blank (25) to the back surface of the foamed resin base material (21);
A method for producing an interior part for an automobile, comprising:

A foamed resin base material (21) that is lightweight and has shape retention, a resin rib (22) laminated and integrated on the back surface of the foamed resin base material (21), and the foamed resin base material (21) A molding die (40) for molding an automotive interior part (20) comprising a decorative material (23) laminated on the surface,
The molding die (40) is connected to the molding upper mold (41) and the molding lower mold (42) which can be clamped and opened with each other, and the molding lower mold (42), and is a material for the resin rib (22). And a product cavity between the molding upper and lower molds (41, 42) is set to a shape corresponding to the product shape of the foamed resin base material (21). In addition, a groove portion (424) corresponding to the resin rib (22) is provided on the mold surface of the core portion (421) of the molded lower mold (42), and the foamed resin is formed along the outer peripheral edge portion of the molded lower mold (42). A molding die characterized in that a pressing mechanism (44) for forming a thin hinge portion (24) serving as a folding base point of a winding scissor (25) of a base material (21) is disposed.

A foamed resin base material (21) that is lightweight and has shape retention, a resin rib (22) laminated and integrated on the back surface of the foamed resin base material (21), and the foamed resin base material (21) A molding die (40) for molding an automotive interior part (20) comprising a decorative material (23) laminated on the surface,
The molding die (40) is connected to the molding upper mold (41) and the molding lower mold (42) which can be clamped and opened with each other, and the molding lower mold (42), and is a material for the resin rib (22). And an injection machine (43) for supplying a molten resin, and the outer peripheral surface of the molded lower mold (42) is cut with a winding scissor (25) on the outer peripheral edge of the foamed resin base material (21). A molding die having a saw blade-shaped cutting portion (45) for the purpose.