JP3858482B2

JP3858482B2 - Manufacturing method of resin molded products

Info

Publication number: JP3858482B2
Application number: JP31926598A
Authority: JP
Inventors: 貴久新美; 久茅野
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1998-11-10
Filing date: 1998-11-10
Publication date: 2006-12-13
Anticipated expiration: 2018-11-10
Also published as: JP2000141412A

Description

【０００１】
【技術分野】
本発明は，樹脂成形品及びその製造方法に関し，特にシール部又は断熱部を有する樹脂成形品の成形方法に関する。
【０００２】
【従来技術】
近年，廃棄物低減のためリサイクルが盛んに行われている。従来，樹脂成形品で部分的に断熱性及びシール性を要する製品には，ウレタン，ゴム，エラストマーのような断熱性やシール性を有する異種材を貼り付けたり成形をすることが行われていた。
【０００３】
【解決しようとする課題】
しかしながら，上記従来の方法では，異種材を貼り合わせたり成形するには製造上の手間がかかる。また，リサイクルする際に異種材を分離する必要がある。そのため，リサイクルに手間，労力及びコストがかかり，リサイクル化を妨げる要因となっていた。
【０００４】
本発明はかかる従来の問題点に鑑み，部分的に断熱性及びシール性を要する樹脂成形品の製造が容易で，かつリサイクル化の進行をもたらす樹脂成形品及びその製造方法を提供しようとするものである。
【０００５】
【課題の解決手段】
本発明は，請求項１記載のように，樹脂材と発泡剤とからなる発泡性樹脂材料を成形型のキャビティ内に注入して部分発泡させて，発泡剤を発泡させた発泡部と，発泡剤を発泡させない未発泡部とからなる樹脂成形品を製造する方法であって，
上記成形型は，樹脂成形品を成形するキャビティと，該キャビティ内における少なくとも上型面または下型面のいずれか一方を拡大し得る可動型と，上記キャビティ内に突き出し可能に進退する突き出しピンと，上記発泡部形成部分を加熱する加熱手段と，キャビティ内に発泡性樹脂材料を注入するためのゲートとからなり，
上記ゲートからキャビティ内に発泡性樹脂材料を射出し，上記可動型を移動させて発泡性樹脂材料と型面との間に発泡用空間を形成し，加熱手段により発泡部形成部分における発泡性樹脂材料を発泡させるに当たり，
上記成形型のキャビティ内に発泡性樹脂材料を射出した後に上記可動型をキャビティ拡大方向に移動させ，上記突き出しピンをキャビティ内に突き出すことにより上記発泡性樹脂材料を上記突き出しピンにより上記可動型と型面との間に支持し位置決めして上記発泡性樹脂材料の上下に上記発泡用空間を形成することを特徴とする樹脂成形品の製造方法である。
【０００６】
本発明においては，発泡性樹脂材料を射出した後にキャビティ内における発泡部形成部分に発泡用空間を形成し，該発泡部形成部分を加熱し発泡性樹脂材料の発泡部形成部分を発泡させて発泡部を形成する。
一方，キャビティ内の発泡性樹脂材料の発泡部形成部分以外の部分は，加熱されず発泡しないため，未発泡部となる。
以上のごとく，本発明によれば，発泡部と未発泡部とからなる部分発泡成形体を製造することができる。
【０００７】
そして，発泡部は，未発泡部よりも弾性が高く，断熱性及びシール性に優れている。そのため，発泡部は，断熱部またはシール部として用いることができる。従って，樹脂成形品に，断熱材及びシール材としての異種材を貼り付ける必要はなく，製造容易である。また，異種材を分離する必要はなく，リサイクル性にも優れている。
【０００９】
本発明では，上記成形型は，キャビティにおける少なくとも上型面または下型面のいずれか一方を拡大し得る可動型と，キャビティ内に突き出し可能に進退する突き出しピンとを有し，かつ上記成形型のキャビティ内に発泡性樹脂材料を射出した後に上記可動型をキャビティ拡大方向に移動させ，上記突き出しピンをキャビティ内に突き出すことにより上記発泡性樹脂材料を上記突き出しピンにより上記可動型と型面との間に支持し位置決めして上記発泡性樹脂材料の上下に上記発泡用空間を形成する。
【００１１】
これにより，既知の成形型を用いて発泡用空間を容易に形成することができる。
【００１２】
また，請求項２記載のように，上記成形型を冷媒で冷却することが好ましい。これにより，発泡させたい部位の発泡剤のみを発泡させることができ，発泡部の形状制御が容易となる。冷媒としては，水，エアなどがある。
【００１３】
請求項３記載のように，上記加熱手段は，ヒータまたはグロープラグであることが好ましい。発泡用空間を局所的に加熱することができる。
【００１４】
発泡性樹脂材料に含まれている発泡剤としては，例えば揮発性発泡剤または化学発泡剤などを用いることができるが，これらに限定されない。
【００１５】
樹脂材と発泡剤とからなる発泡性樹脂材料を成形型のキャビティ内に射出して部分発泡させて，発泡性樹脂材料を発泡させた発泡部と，発泡性樹脂材料を発泡させない未発泡部とを一体成形してなることを特徴とする樹脂成形品がある。
【００１６】
上記樹脂成形品は，部分発泡させて得られたものであるので，製造が容易である。また，樹脂成形品は，部分発泡成形品であるため，発泡部と未発泡部との組成が同じであり，リサイクルを容易に行うことができる。
また，発泡部は断熱性及びシール性を有するため，これらの性質を要する部材として利用できる。
本発明の樹脂成形品は，例えば，自動車の内外気切替え装置，エアコンディショナーのダクト，ダンパー，ケースなどに用いることができるが，これらに限定されない。
【００１７】
【発明の実施の形態】
実施形態例１
本発明の実施形態に係る樹脂成形品について，図１〜図５を用いて説明する。
本例の樹脂成形品７は，図１（ａ），図１（ｂ）に示すごとく，樹脂材と発泡剤とからなる発泡性樹脂材料を成形型のキャビティ内に射出して部分発泡させて，発泡性樹脂材料を発泡させた発泡部７１と，発泡性樹脂材料を発泡させない未発泡部７２とからなる一体成形品である。
【００１８】
樹脂成形品７はダンパであり，平板部７３２とその周囲を囲むシール部７３１と回動軸７３３とからなる。シール部７３１は発泡部７１からなり，平板部７３２及び回動軸７３３は未発泡部７２からなる。
【００１９】
樹脂成形品の製造方法について説明する。
図２に示すごとく，射出成形用の成形型１９を準備する。成形型１９は，樹脂成形品を成形するキャビティ１と，キャビティ１内における少なくとも発泡部形成部分１０１を拡大させ得る可動性の下型１２と，上型１１と，発泡部形成部分１０１を加熱する加熱手段２と，キャビティ１内に発泡性樹脂材料を注入するためのゲート１３と，キャビティ１内に進退可能に取付けた突き出しピン４とからなる。
成形型１９は，成形機６に対して，固定金具６１により固定されている。
【００２０】
図３（ａ）に示すごとく，加熱手段２は，電熱ヒータであり，一端に配線部２１を設けている。加熱手段２は，キャビティ１内を発泡剤が発泡可能な温度，例えば２００℃以上に加熱する。加熱手段２の周囲には，発泡部形成部分１０１以外の部分が加熱されないように冷媒管３が配設されている。冷媒管３の中には水が充填されており，成形型の外部に設けたクーラーとの間を循環するよう構成されている。
【００２１】
成形型１９のキャビティ１は，図２，図３（ｂ）に示すごとく，上型１１の上型面１０５と下型１２の下型面１０６との間に形成されている。キャビティ１は，樹脂成形品の未発泡部を形成するための未発泡部形成部分１０２と，発泡部を形成するための発泡部形成部分１０１とからなる。
上型１１と下型１２とを型締めしたときの発泡部形成部分１０１の厚みは例えば４ｍｍであり，未発泡部形成部分１０２の厚みは１ｍｍであって，前者は後者よりも肉厚である。
【００２２】
図４（ａ）に示すごとく，上型１１は，発泡部形成部分１０１の上型面１０５を形成する加熱部１１２と，未発泡部形成部分１０２の上型面１０５を形成する非加熱部１１１とからなる。加熱部１１２は，熱伝導性のよい材料，例えばアルミニウムからなる。加熱部１１２の中には，加熱手段２が設けられている。加熱手段２は閉止部材１１３の開閉により出し入れ可能に埋設されている。一方，非加熱部１１１は，熱伝導性に劣る材料，例えば鉄からなる。非加熱部１１１には，冷媒管３が埋設されている。
また，下型１２も，上記上型１１と同様の加熱部と非加熱部とからなる。
【００２３】
なお，図４（ｂ）に示すごとく，加熱部１１２と非加熱部１１１との間には，断熱材１１４を設けてもよい。これにより，加熱部１１２の熱が非加熱部１１１に伝達されにくく，発泡部形成部分１０１だけを加熱することができる。断熱材１１４は，例えば耐熱積層板などを用いることができる。また，加熱部１１２と非加熱部１１１との間には，上記断熱材の代わりに空隙を設けてもよい。
【００２４】
次に，図５（ａ）に示すごとく，上型１１と下型１２とを型締めし，ゲート１３より発泡性樹脂材料７０をキャビティ１内に射出する。発泡性樹脂材料７０は，例えば発泡剤２０重量％と，樹脂材８０重量％とからなる。
次に，図５（ｂ）に示すごとく，射出したキャビティ１内の発泡性樹脂材料７０が取出し可能な温度となった後，下型１２を下方に動かす。すると，発泡性樹脂材料７０は下型１２の下型面１０６にしたがって下降し，上型１１の上型面１０５と離型する。
【００２５】
次に，図５（ｃ）に示すごとく，突き出しピン４をキャビティ１内に進出させて，下型面１０６に配置されている発泡性樹脂材料７０を持ち上げて，キャビティ１の上型面１０５と下型面１０６との間の例えば中央に支持する。すると，キャビティ１の発泡部形成部分１０１における，発泡性樹脂材料７０の上下に，発泡用空間１０が形成される。
【００２６】
次に，図５（ｄ）に示すごとく，加熱手段２により予め２００℃以上に加熱されているため，発泡性樹脂材料７０の発泡部形成部分１０１が加熱発泡して，発泡部７１が形成される。一方，発泡部形成部分１０１以外の部分に射出された発泡性樹脂材料７０は，加熱されないため，発泡せず，未発泡部７２となる。
その後，下型１２を下方に移動させて，樹脂成形品７を取出す。
以上により，部分発泡させた樹脂成形品７が得られる。
【００２７】
得られた樹脂成形品７の発泡部７１は，断熱性及びシール性があり，自動車の内外気切替え装置のダンパとして用いられる（図１４参照）。
【００２８】
本例の樹脂成形品７は部分発泡品であるため，断熱材及びシール材としての異種材を貼り付ける必要はなく，製造容易である。また，異種材を分離する必要はなく，リサイクル性にも優れている。
また，未発泡部形成部分１０２の型面を形成する加熱部１１２と，発泡成形部分１０１の型面を形成する非加熱部１１１との境界付近には，冷媒管３を設けている。冷媒管３は，加熱ヒータ２の熱を未発泡部形成部分１０２に伝達させない。そのため，発泡部形成部分１０１と未発泡部形成部分１０２との境界を明確にすることができる。
発泡部形成部分１０１は未発泡部形成部分１０２よりも肉厚であるため，発泡倍率が高くても発泡時に拡大した発泡部形成部分１０１全体に発泡性樹脂材料７０が体積膨張し，設計形状にあった形状の発泡部７１を形成できる。
【００２９】
実施形態例２
本例においては，図６（ａ）に示すごとく，上型１１と下型１２とを型締めしたときのキャビティ１内における，発泡部形成部分１０１と未発泡部形成部分１０２との厚みが例えば１ｍｍと同じである。
【００３０】
図６（ａ）に示すごとく，加熱手段２によりキャビティ１内の発泡部形成部分１０１を加熱する。次いで，上記キャビティ１内にゲート１３より発泡性樹脂材料７０を射出する。次いで，実施形態例１と同様に下型１２の下降（図５（ｂ）），突き出しピン４による発泡性樹脂材料７０の支持（図５（ｃ））を行う。すると，図６（ｂ）に示すごとく，発泡部形成部分１０１における発泡性樹脂材料７０が発泡し体積膨張する。一方，未発泡形成部分１０２における発泡性樹脂材料７０は発泡しない。これにより，実施形態例１と同様の部分発泡した樹脂成形品７が得られる。
その他は，実施形態例１と同様である。
【００３１】
参考例１
本例の樹脂成形品７は，図７（ｂ）に示すごとく，片面側にだけ発泡部７１をもつ。
片面発泡させた樹脂成形品を成形するに当たっては，実施形態例１と同様に加熱手段２によりキャビティ１内の発泡部形成部分１０１を加熱する。次いで，キャビティ１内に発泡性樹脂材料７０を射出し，図７（ａ）に示すごとく，下型１２を下方に移動させる。すると，発泡部形成部分１０１における発泡性樹脂材料７０の上面側に発泡用空間１０が形成される。すると，図７（ｂ）に示すごとく，発泡部形成部分１０１における発泡性樹脂材料７０が発泡し，体積膨張して，発泡用空間１０に充満する。以上により，本例の片面発泡させた樹脂成形品７が得られる。その他は，実施形態例１と同様である。
【００３２】
参考例２
本例の成形型の上型１１は，図８に示すごとく，キャビティ１内における発泡部形成部分１０１を拡大させ得る可動型１１６と，発泡部形成部分以外の部分の型面を形成する一般型１１５とからなる。また，下型１２も，可動型１２６と一般型１２５とからなる。可動型１１６，１２６はアルミニウムからなり，内部に加熱手段２が埋設されている。一般型１１５，１２５は鉄からなり，内部に冷媒管３が埋設されている。
【００３３】
上記成形型を用いて樹脂成形品７を成形するに当たっては，まず，図８に示すごとく，可動型１１６，１２６をキャビティ１内に進行させた状態で，加熱手段２によりキャビティ１内の発泡部形成部分１０１を加熱する。次いで，キャビティ１内に発泡性樹脂材料７０をゲート１３より射出する。
次いで，図９（ａ）に示すごとく，可動ダイ１１６，１２６をキャビティ１内から後退させて発泡用空間１０を形成する。
【００３４】
すると，図９（ｂ）に示すごとく，発泡部形成部分１０１における発泡性樹脂材料７０が加熱発泡し体積膨張し，発泡用空間１０に充満する。一方，未発泡部形成部分１０２における発泡性樹脂材料７０は発泡せず，未発泡部７２となる。
以上により，部分発泡させた樹脂成形品７を得る。
【００３５】
実施形態例３
本例においては，図１０に示すごとく，加熱手段として複数のグロープラグ２２を用いている。グロープラグ２２の先端加熱部２２０は，上型１１及び下型における発泡部形成部分１０１に対向するように装着されている。グロープラグ２２は，上型１１及び下型の移動方向に沿って配置されている。
【００３６】
グロープラグ２２は自己制御型であり，図１１に示すごとく，発熱体２２１を内蔵したヒータケース２２５と，ハウジング２２６とを有する。発熱体２２１は，先端側に配置された発熱コイル２２２と，後端側に配置された制御コイル２２３とからなる。ヒータケース２２５と発熱体との間には電気絶縁材２２７が設けられている。ハウジング２２６は，外部接続端子２２４と接続されている。
グロープラグ２２を作動させると，発熱コイル２２２が配置されている先端加熱部２２０が瞬時に加熱される。
その他は，実施形態例１と同様である。
【００３７】
グロープラグ２２は，局部を短時間で加熱することができるため，発泡部形成部分１０１の急激な加熱に適している。その他は，本例においても，実施形態例１と同様の効果を得ることができる。
【００３８】
実施形態例４
本例は，図１２に示すごとく，複数のグロープラグ２２を上型１１及び下型の移動方向と垂直方向に沿って配列している。その他は，実施形態例３と同様である。本例においても，実施形態例３と同様の効果を得ることができる。
【００３９】
実施形態例５
本例の樹脂成形品は，図１３，図１４に示すごとく，自動車の内外気切替え装置７９である。内外気切替え装置７９は，内気通路７０８及び外気通路７０９と，内外気通路の接続部７０１，７０５，７０７と，相手部材を取付けるための取付け部７０２，７０３と，内外気切替え用の窓部７０４，７０６とを設けている。また，内外気切替え装置７９の全体は，樹脂剤と発泡剤とからなり，その中の上記接続部，取付け部及び窓部は発泡剤を発泡させた発泡部７１からなる。一方，他の部分は未発泡部７２からなる。
【００４０】
また，内外気切替え装置７９は，窓部７０４，７０６の開閉を行うためのダンパ７００を取付けている。ダンパ７００の構造は実施形態例１と同様であり（図１参照），そのシール部７３１は発泡部からなり，平板部７３２及び回動軸７３３は未発泡部からなる。
ダンパ７００は，回動軸７３を中心に回動可能に，窓部７０４，７０６の間に設けた支軸７３０に取付けられている。
【００４１】
ダンパ７００の矢印Ｓ方向への回動により，ダンパ７００のシール部７３１が内気導入用の窓部７０４を閉止する。一方，矢印Ｒ方向への回動により，ダンパ７００のシール部７３１が外気導入用の窓部７０６を閉止する。
【００４２】
本例の内外気切替え装置７９及びダンパ７００は，接続部及び開閉部が発泡部７１から構成されているため，弾性，シール性及び断熱性が高い。また，これらｈ部分発泡成形品であるため，リサイクル性も高い。また，実施形態例１で詳細に説明したように，一の成形型によって容易に成形，部分発泡させることができるため，製造も容易である。
【図面の簡単な説明】
【図１】実施形態例１の樹脂成形品の斜視図（ａ），及び（ａ）のＡ−Ａ線矢視断面図（ｂ）。
【図２】実施形態例１の樹脂成形品を成形するための成形型の断面図。
【図３】図２のＢ−Ｂ線矢視断面図（ａ）及びＣ−Ｃ線矢視断面図（ｂ）。
【図４】実施形態例１の上型における加熱部及び非加熱部を示すための断面説明図（ａ）及び，加熱部と非加熱部の間に断熱材を設けた上型の断面説明図（ｂ）。
【図５】実施形態例１の樹脂成形品の製造方法を示すための説明図（ａ）〜（ｄ）。
【図６】実施形態例２の樹脂成形品の製造方法を示すための説明図（ａ）〜（ｂ）。
【図７】参考例１の樹脂成形品の製造方法を示すための説明図（ａ）〜（ｂ）。
【図８】参考例２の成形型の断面説明図。
【図９】参考例２の樹脂成形品の製造方法を示すための説明図（ａ）〜（ｂ）。
【図１０】実施形態例３の加熱手段の配置を示すための，上型の断面説明図（ａ）及び（ａ）のＥ−Ｅ線矢視断面図（ｂ）。
【図１１】実施形態例３のグロープラグの断面図。
【図１２】実施形態例４の加熱手段の配置を示すための，上型の断面説明図（ａ）及び（ａ）のＦ−Ｆ線矢視断面図（ｂ）。
【図１３】実施形態例５の内外気切替え装置の斜視図。
【図１４】図１３のＤ−Ｄ線矢視断面図。
【符号の説明】
１．．．キャビティ，
１０．．．発泡用空間，
１１．．．上型，
１２．．．下型，
１３．．．ゲート，
１０１．．．発泡部形成部分，
１０２．．．未発泡部形成部分，
１０５．．．上型面，
１０６．．．下型面，
１１１．．．非加熱部，
１１２．．．加熱部，
１１４．．．断熱材，
１１５，１２５．．．一般型，
１１６，１２６．．．可動型，
２．．．加熱手段，
２２．．．グロープラグ，
３．．．冷媒管，
４．．．突き出しピン，
７．．．樹脂成形品，
７０．．．発泡性樹脂材料，
７１．．．発泡部，
７２．．．未発泡部，
７９．．．内外気切替え装置，
７００．．．ダンパ，
７３１．．．シール部，
７３２．．．平板部，
７３３．．．回動軸，[0001]
【Technical field】
The present invention relates to a resin molded product and a manufacturing method thereof, and more particularly to a method of molding a resin molded product having a seal part or a heat insulating part.
[0002]
[Prior art]
In recent years, recycling has been actively performed to reduce waste. Conventionally, resin molded products that require partial heat insulation and sealing have been made by attaching or molding dissimilar materials with heat insulation and sealing properties such as urethane, rubber, and elastomer. .
[0003]
[Problems to be solved]
However, in the above conventional method, it takes time and effort to bond and form different materials. It is also necessary to separate different materials when recycling. For this reason, it takes time, labor and cost to recycle, which is a factor that hinders recycling.
[0004]
SUMMARY OF THE INVENTION In view of the conventional problems, the present invention intends to provide a resin molded product that can easily produce a resin molded product that partially requires heat insulation and sealing properties, and that promotes recycling, and a method for manufacturing the resin molded product. It is.
[0005]
[Means for solving problems]
According to the present invention, a foaming resin material made of a resin material and a foaming agent is injected into a cavity of a molding die to partially foam the foamed portion, and the foaming agent is foamed. A method for producing a resin molded product comprising an unfoamed part that does not foam the agent,
The mold includes a cavity for molding a resin molded product, a movable mold capable of enlarging at least one of the upper mold surface and the lower mold surface in the cavity, a projecting pin that can be projected and retracted into the cavity , The heating means for heating the foamed portion forming portion and a gate for injecting a foamable resin material into the cavity,
The foamable resin material is injected from the gate into the cavity, the movable mold is moved to form a foaming space between the foamable resin material and the mold surface, and the foamable resin in the foamed portion forming portion is formed by heating means. In foaming the material ,
After injecting the foamable resin material into the cavity of the mold, the movable mold is moved in the cavity enlargement direction, and the protruding pin is protruded into the cavity so that the foamable resin material is separated from the movable mold by the protruding pin. It is a method for producing a resin molded product, characterized in that the foaming spaces are formed above and below the foamable resin material by supporting and positioning between the mold surfaces .
[0006]
In the present invention, after injecting the foamable resin material, a foaming space is formed in the foamed portion forming portion in the cavity, and the foamed portion forming portion is heated to foam and expand the foamed portion forming portion of the foamable resin material. Forming part.
On the other hand, portions other than the foamed portion forming portion of the foamable resin material in the cavity are not heated and do not foam, and thus become unfoamed portions.
As described above, according to the present invention, it is possible to manufacture a partially foamed molded body including a foamed part and an unfoamed part.
[0007]
The foamed portion has higher elasticity than the non-foamed portion, and is excellent in heat insulation and sealing properties. Therefore, the foamed part can be used as a heat insulating part or a seal part. Therefore, it is not necessary to affix different types of materials as a heat insulating material and a sealing material to the resin molded product, and it is easy to manufacture. In addition, it is not necessary to separate different materials and is excellent in recyclability.
[0009]
In the present invention, the mold has a movable mold capable of enlarging at least one of the upper mold surface and the lower mold surface in the cavity, and a projecting pin that can be projected and retracted into the cavity. After injecting the foamable resin material into the cavity, the movable mold is moved in the cavity enlargement direction, and the protruding pin is protruded into the cavity so that the foamable resin material is moved between the movable mold and the mold surface by the protruding pin. The foaming spaces are formed above and below the foamable resin material by supporting and positioning between them .
[0011]
Thereby, the foaming space can be easily formed using a known mold.
[0012]
Also, as in claim 2, it is preferable to cool the mold by the refrigerant. Thereby, only the foaming agent of the site | part which wants to foam can be foamed, and the shape control of a foaming part becomes easy. Examples of the refrigerant include water and air.
[0013]
As described in claim 3 , the heating means is preferably a heater or a glow plug. The foaming space can be locally heated.
[0014]
As a foaming agent contained in the foamable resin material, for example, a volatile foaming agent or a chemical foaming agent can be used, but it is not limited thereto.
[0015]
A foamed resin material and a foaming agent are injected into the mold cavity and partially foamed to foam the foamable resin material, and an unfoamed part that does not foam the foamable resin material. There is a resin molded product characterized by being integrally molded.
[0016]
Since the resin molded product is obtained by partial foaming, it is easy to manufacture. Further, since the resin molded product is a partially foamed molded product, the composition of the foamed part and the unfoamed part is the same, and recycling can be easily performed.
In addition, since the foamed portion has a heat insulating property and a sealing property, it can be used as a member requiring these properties.
The resin molded product of the present invention can be used for, for example, an automobile inside / outside air switching device, an air conditioner duct, a damper, a case, and the like, but is not limited thereto.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
A resin molded product according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 (a) and 1 (b), the resin molded product 7 of this example is obtained by injecting a foamable resin material made of a resin material and a foaming agent into a cavity of a molding die and partially foaming. , An integrally molded product including a foamed portion 71 obtained by foaming a foamable resin material and an unfoamed portion 72 where the foamable resin material is not foamed.
[0018]
The resin molded product 7 is a damper, and includes a flat plate portion 732, a seal portion 731 surrounding the periphery thereof, and a rotating shaft 733. The seal portion 731 includes a foamed portion 71, and the flat plate portion 732 and the rotation shaft 733 include an unfoamed portion 72.
[0019]
A method for producing a resin molded product will be described.
As shown in FIG. 2, a molding die 19 for injection molding is prepared. The mold 19 heats the cavity 1 for molding the resin molded product, the movable lower mold 12 capable of enlarging at least the foamed part forming part 101 in the cavity 1, the upper mold 11, and the foamed part forming part 101. The heating means 2, a gate 13 for injecting a foamable resin material into the cavity 1, and a protruding pin 4 attached to the cavity 1 so as to be able to advance and retract.
The molding die 19 is fixed to the molding machine 6 with a fixing bracket 61.
[0020]
As shown in FIG. 3A, the heating means 2 is an electric heater and has a wiring portion 21 at one end. The heating means 2 heats the inside of the cavity 1 to a temperature at which the foaming agent can foam, for example, 200 ° C. or higher. A refrigerant pipe 3 is disposed around the heating means 2 so that portions other than the foamed portion forming portion 101 are not heated. The refrigerant pipe 3 is filled with water and is configured to circulate between a cooler provided outside the mold.
[0021]
As shown in FIGS. 2 and 3B, the cavity 1 of the mold 19 is formed between the upper mold surface 105 of the upper mold 11 and the lower mold surface 106 of the lower mold 12. The cavity 1 includes an unfoamed portion forming portion 102 for forming an unfoamed portion of the resin molded product and a foamed portion forming portion 101 for forming the foamed portion.
When the upper mold 11 and the lower mold 12 are clamped, the thickness of the foamed portion forming portion 101 is, for example, 4 mm, the thickness of the unfoamed portion forming portion 102 is 1 mm, and the former is thicker than the latter. .
[0022]
As shown in FIG. 4A, the upper mold 11 includes a heating part 112 that forms the upper mold surface 105 of the foamed part forming portion 101 and a non-heated part 111 that forms the upper mold surface 105 of the non-foamed part forming part 102. It consists of. The heating unit 112 is made of a material having good thermal conductivity, for example, aluminum. A heating means 2 is provided in the heating unit 112. The heating means 2 is embedded so that it can be taken in and out by opening and closing the closing member 113. On the other hand, the non-heating portion 111 is made of a material having poor thermal conductivity, for example, iron. A refrigerant pipe 3 is embedded in the non-heating unit 111.
The lower mold 12 also includes a heating part and a non-heating part similar to the upper mold 11.
[0023]
As shown in FIG. 4B, a heat insulating material 114 may be provided between the heating unit 112 and the non-heating unit 111. Thereby, the heat of the heating part 112 is hardly transmitted to the non-heating part 111, and only the foaming part forming part 101 can be heated. As the heat insulating material 114, for example, a heat-resistant laminated plate or the like can be used. Moreover, you may provide a space | gap instead of the said heat insulating material between the heating part 112 and the non-heating part 111. FIG.
[0024]
Next, as shown in FIG. 5A, the upper mold 11 and the lower mold 12 are clamped, and the foamable resin material 70 is injected into the cavity 1 from the gate 13. The foamable resin material 70 comprises, for example, 20% by weight of a foaming agent and 80% by weight of a resin material.
Next, as shown in FIG. 5B, after the foamable resin material 70 in the injected cavity 1 reaches a temperature at which it can be taken out, the lower mold 12 is moved downward. Then, the foamable resin material 70 descends according to the lower mold surface 106 of the lower mold 12 and is released from the upper mold surface 105 of the upper mold 11.
[0025]
Next, as shown in FIG. 5 (c), the protruding pin 4 is advanced into the cavity 1 to lift the foamable resin material 70 disposed on the lower mold surface 106, and the upper mold surface 105 of the cavity 1 and For example, it is supported at the center between the lower mold surface 106. Then, foaming spaces 10 are formed above and below the foamable resin material 70 in the foamed portion forming portion 101 of the cavity 1.
[0026]
Next, as shown in FIG. 5D, since the heating means 2 has been heated to 200 ° C. or higher in advance, the foamed portion forming portion 101 of the foamable resin material 70 is heated and foamed to form the foamed portion 71. The On the other hand, since the foamable resin material 70 injected into the portion other than the foamed portion forming portion 101 is not heated, it does not foam and becomes an unfoamed portion 72.
Thereafter, the lower mold 12 is moved downward to take out the resin molded product 7.
In this way, a partially molded resin molded product 7 is obtained.
[0027]
The foamed part 71 of the obtained resin molded product 7 has a heat insulating property and a sealing property, and is used as a damper for an inside / outside air switching device of an automobile (see FIG. 14).
[0028]
Since the resin molded product 7 of this example is a partially foamed product, it is not necessary to affix different materials as a heat insulating material and a sealing material, and it is easy to manufacture. In addition, it is not necessary to separate different materials and is excellent in recyclability.
A refrigerant pipe 3 is provided in the vicinity of the boundary between the heating part 112 that forms the mold surface of the unfoamed part forming part 102 and the non-heating part 111 that forms the mold surface of the foam-molded part 101. The refrigerant tube 3 does not transmit the heat of the heater 2 to the unfoamed portion forming portion 102. Therefore, the boundary between the foamed portion forming portion 101 and the unfoamed portion forming portion 102 can be clarified.
Since the foamed portion forming portion 101 is thicker than the unfoamed portion forming portion 102, the foamable resin material 70 expands in volume over the entire foamed portion forming portion 101 expanded at the time of foaming even when the foaming ratio is high, resulting in a design shape. The foamed portion 71 having a suitable shape can be formed.
[0029]
Embodiment 2
In this example, as shown in FIG. 6A, the thicknesses of the foamed portion forming portion 101 and the unfoamed portion forming portion 102 in the cavity 1 when the upper mold 11 and the lower mold 12 are clamped are, for example, It is the same as 1 mm.
[0030]
As shown in FIG. 6A, the foaming portion forming portion 101 in the cavity 1 is heated by the heating means 2. Next, a foamable resin material 70 is injected into the cavity 1 from the gate 13. Next, as in the first embodiment, the lower mold 12 is lowered (FIG. 5B), and the foamable resin material 70 is supported by the protruding pins 4 (FIG. 5C). Then, as shown in FIG. 6B, the foamable resin material 70 in the foamed portion forming portion 101 foams and expands in volume. On the other hand, the foamable resin material 70 in the unfoamed portion 102 does not foam. As a result, a partially foamed resin molded product 7 similar to that in Embodiment 1 is obtained.
Others are the same as in the first embodiment.
[0031]
Reference example 1
As shown in FIG. 7B, the resin molded product 7 of this example has a foamed portion 71 only on one side.
In molding a resin molded product that is foamed on one side, the foamed portion forming portion 101 in the cavity 1 is heated by the heating means 2 as in the first embodiment. Next, the foamable resin material 70 is injected into the cavity 1, and the lower mold 12 is moved downward as shown in FIG. Then, the foaming space 10 is formed on the upper surface side of the foamable resin material 70 in the foamed portion forming portion 101. Then, as shown in FIG. 7B, the foamable resin material 70 in the foamed portion forming portion 101 is foamed, volume-expanded, and fills the foaming space 10. As described above, the resin molded product 7 which is foamed on one side of this example is obtained. Others are the same as in the first embodiment.
[0032]
Reference example 2
As shown in FIG. 8, the upper die 11 of the molding die of this example includes a movable die 116 that can enlarge the foamed portion forming portion 101 in the cavity 1 and a general die that forms a die surface other than the foamed portion forming portion. 115. The lower mold 12 is also composed of a movable mold 126 and a general mold 125. The movable molds 116 and 126 are made of aluminum, and the heating means 2 is embedded therein. The general molds 115 and 125 are made of iron, and the refrigerant pipe 3 is embedded therein.
[0033]
In molding the resin molded product 7 using the molding die, first, as shown in FIG. 8, the foaming portion in the cavity 1 is heated by the heating means 2 while the movable molds 116 and 126 are advanced into the cavity 1. The formation part 101 is heated. Next, a foamable resin material 70 is injected from the gate 13 into the cavity 1.
Next, as shown in FIG. 9A, the movable dies 116 and 126 are retracted from the cavity 1 to form the foaming space 10.
[0034]
Then, as shown in FIG. 9B, the foamable resin material 70 in the foamed portion forming portion 101 is heated and foamed to expand in volume and fill the foaming space 10. On the other hand, the foamable resin material 70 in the unfoamed portion forming portion 102 does not foam but becomes the unfoamed portion 72.
Thus, a partially molded resin molded product 7 is obtained.
[0035]
Embodiment 3
In this example, as shown in FIG. 10, a plurality of glow plugs 22 are used as heating means. The tip heating portion 220 of the glow plug 22 is mounted so as to face the foamed portion forming portion 101 in the upper mold 11 and the lower mold. The glow plug 22 is disposed along the movement direction of the upper mold 11 and the lower mold.
[0036]
The glow plug 22 is a self-control type, and has a heater case 225 with a built-in heating element 221 and a housing 226 as shown in FIG. The heating element 221 includes a heating coil 222 disposed on the front end side and a control coil 223 disposed on the rear end side. An electrical insulating material 227 is provided between the heater case 225 and the heating element. The housing 226 is connected to the external connection terminal 224.
When the glow plug 22 is actuated, the tip heating unit 220 in which the heat generating coil 222 is arranged is instantaneously heated.
Others are the same as in the first embodiment.
[0037]
Since the glow plug 22 can heat the local portion in a short time, it is suitable for rapid heating of the foamed portion forming portion 101. Other than this, also in this example, the same effects as those of the first embodiment can be obtained.
[0038]
Embodiment 4
In this example, as shown in FIG. 12, a plurality of glow plugs 22 are arranged along the direction perpendicular to the movement direction of the upper mold 11 and the lower mold. Others are the same as the third embodiment . Also in this example, the same effect as in the third embodiment can be obtained.
[0039]
Embodiment 5
The resin molded product of this example is an inside / outside air switching device 79 of an automobile as shown in FIGS. The inside / outside air switching device 79 includes an inside air passage 708 and an outside air passage 709, inside / outside air passage connecting portions 701, 705, 707, attachment portions 702, 703 for attaching mating members, and inside / outside air switching windows 704. , 706. The entire inside / outside air switching device 79 is made of a resin agent and a foaming agent, and the connecting portion, the mounting portion, and the window portion therein are made of a foaming portion 71 obtained by foaming the foaming agent. On the other hand, the other part consists of an unfoamed part 72.
[0040]
The inside / outside air switching device 79 is provided with a damper 700 for opening and closing the windows 704 and 706. The structure of the damper 700 is the same as that of the first embodiment (see FIG. 1), the seal portion 731 is a foamed portion, and the flat plate portion 732 and the rotating shaft 733 are unfoamed portions.
The damper 700 is attached to a support shaft 730 provided between the window portions 704 and 706 so as to be rotatable about the rotation shaft 73.
[0041]
By the rotation of the damper 700 in the arrow S direction, the seal portion 731 of the damper 700 closes the window portion 704 for introducing the inside air. On the other hand, the seal portion 731 of the damper 700 closes the window portion 706 for introducing outside air by the rotation in the direction of the arrow R.
[0042]
The inside / outside air switching device 79 and the damper 700 of this example have high elasticity, sealing properties, and heat insulation properties because the connecting portion and the opening / closing portion are constituted by the foamed portion 71. In addition, since these h partial foamed molded products, recyclability is also high. Further, as described in detail in the first embodiment, since it can be easily molded and partially foamed with a single mold, it is easy to manufacture.
[Brief description of the drawings]
FIG. 1A is a perspective view of a resin molded product according to Embodiment 1 and FIG. 1B is a cross-sectional view taken along line AA in FIG.
FIG. 2 is a cross-sectional view of a molding die for molding a resin molded product according to Embodiment 1;
3 is a cross-sectional view taken along line B-B in FIG. 2 (a) and a cross-sectional view taken along line C-C (b).
FIG. 4 is a cross-sectional explanatory view (a) for showing a heating part and a non-heating part in the upper mold of Embodiment 1 and a cross-sectional explanatory view of the upper mold in which a heat insulating material is provided between the heating part and the non-heating part. (B).
FIGS. 5A to 5D are explanatory views (a) to (d) for illustrating a method for producing a resin molded product according to Embodiment 1. FIG.
6A to 6B are explanatory views (a) to (b) for illustrating a method for producing a resin molded product according to Embodiment 2. FIG.
7 is an explanatory diagram (a) to (b) for illustrating a method for producing a resin molded product of Reference Example 1. FIG.
8 is a cross-sectional explanatory view of a molding die of Reference Example 2. FIG.
FIG. 9 is an explanatory diagram (a) to (b) for illustrating a method for producing a resin molded product of Reference Example 2 .
FIG. 10 is a cross-sectional explanatory view (a) of the upper mold and a cross-sectional view taken along the line EE of (a) for illustrating the arrangement of the heating means of Embodiment 3. FIG.
11 is a cross-sectional view of a glow plug according to Embodiment 3. FIG.
FIG. 12 is a cross-sectional explanatory view (a) of the upper mold and a cross-sectional view taken along line FF in (a) for illustrating the arrangement of the heating means of the fourth embodiment .
13 is a perspective view of an inside / outside air switching device according to Embodiment 5. FIG.
14 is a cross-sectional view taken along line DD in FIG.
[Explanation of symbols]
1. . . cavity,
10. . . Foaming space,
11. . . Upper mold,
12 . . Lower mold,
13. . . Gate,
101. . . Foamed part forming part,
102. . . Unfoamed part forming part,
105. . . Upper mold surface,
106. . . Lower mold surface,
111. . . Non-heated part,
112. . . Heating section,
114. . . Insulation,
115,125. . . General type,
116,126. . . Movable,
2. . . Heating means,
22. . . Glow plug,
3. . . Refrigerant pipe,
4). . . Protruding pin,
7). . . Resin molded products,
70. . . Foam resin material,
71. . . Foam part,
72. . . Unfoamed part,
79. . . Inside / outside air switching device,
700. . . damper,
731. . . Seal part,
732. . . Flat plate,
733. . . Pivot axis,

Claims

Resin molding consisting of a foamed part that foams foaming agent and a non-foamed part that does not foam the foaming agent by injecting a foamable resin material consisting of resin material and foaming agent into the mold cavity and partially foaming A method of manufacturing an article,
The mold includes a cavity for molding a resin molded product, a movable mold capable of enlarging at least one of the upper mold surface and the lower mold surface in the cavity, and a projecting pin that can be projected and retracted into the cavity . The heating means for heating the foamed portion forming portion and a gate for injecting a foamable resin material into the cavity,
The foamable resin material is injected from the gate into the cavity, the movable mold is moved to form a foaming space between the foamable resin material and the mold surface, and the foamable resin in the foamed portion forming portion is formed by heating means. In foaming the material ,
After injecting the foamable resin material into the cavity of the mold, the movable mold is moved in the cavity enlargement direction, and the protruding pin is protruded into the cavity so that the foamable resin material is separated from the movable mold by the protruding pin. A method for producing a resin molded product , comprising: supporting and positioning between a foam surface and forming the foaming space above and below the foamable resin material .

2. The method for producing a resin molded product according to claim 1, wherein the mold is cooled with a refrigerant.

3. The method of manufacturing a resin molded product according to claim 1, wherein the heating means is a heater or a glow plug.