JP3569832B2

JP3569832B2 - Molds for foam moldings with undercuts

Info

Publication number: JP3569832B2
Application number: JP7949995A
Authority: JP
Inventors: 秋男桐生
Original assignee: Inoac Corp
Current assignee: Inoac Corp
Priority date: 1995-03-10
Filing date: 1995-03-10
Publication date: 2004-09-29
Anticipated expiration: 2019-09-29
Also published as: JPH08244050A

Description

【０００１】
【産業上の利用分野】
この発明は、アンダーカット部を有する発泡成形品の成形金型に関し、更に詳細には、該成形金型における下型の側面開口部を開閉自在に閉成して、アンダーカット部を有する発泡成形品の脱型を容易化する入れ子を、該成形金型における上型の開放動作と連繋して開放させ得るよう構成した提案に関するものである。
【０００２】
【従来技術】
自動車等の車両に使用される乗員用シートは、一般にウレタン樹脂を所要形状に発泡成形したクッション材を基材としている。この乗員用シートは、個別に成形した背もたれ部と座部を組合わせて構成される。例えば背もたれ部となる発泡成形品１０は、図１４に示す如き外観形状に成形され、そのＡ−Ａ線で切断した中央縦断面は図１５に示す形状を呈している。また発泡成形品１０をＢ−Ｂ線で切断した横断面は、図１７に示す形状（但し右半体部分だけを図示）を呈している。この場合に発泡成形品１０は、乗員の胴部両脇を左右から包持し得るように、その背当て部より外方へ僅かに延出する突出部１２が一体成形されるようになっている。この突出部１２は、図に示すように、成形金型１４における下型１６の型内面に対し傾斜するオーバーハング部分を有しているので、これは一般にアンダーカット部と称され、往々にして発泡成形品１０を金型から脱型する際の妨げとなっている。
【０００３】
図１３および図１５において成形金型１４は、発泡成形品１０の表面側を成形する下型１６と、この下型１６に対して開閉自在に設けられ、該発泡成形品１０の裏面側となる部分を成形する上型１８と、この上型１８に対して開閉自在に設けられ、該発泡成形品１０の裏面にリップ部２２を成形する湾入部２４を備えた中型２０とから構成される。このリップ部２２は、発泡成形品１０にシートの骨格となるパイプフレームを設けた際に、該フレームに張設した弾性ワイヤ（何れも図示せず）を抱持的に被覆するものである。
【０００４】
発泡成形に際しては、図示しない注入器によりウレタン原液を下型１６の底面に注入した後、該下型１６に対して中型２０を所定位置まで閉成させ、次いで該中型２０に対し上型１８を閉成して（型締め）、該ウレタン原液の発泡反応を進行させる。ここでウレタン原液は、例えばポリエーテルポリオールを主成分とし、発泡剤・触媒・架橋剤等を添加した第１液と、ポリイソシアネートからなる第２液との混合撹拌液からなる。そして反応混合物が飽和するクリームタイムを経過させると、ウレタン原液は発泡しながらウレタンフォームとなって成形金型１４の内部に充満する。発泡成形が終了したところで、図１６に示すように、下型１６に対し上型１８を開放させ（このとき上型１８は中型２０に対しても開放する）、次いで中型２０を下型１６から開放することにより、前記リップ部２２を備える所要形状の発泡成形品１０が成形される。前述したところは所謂オープン注入法によるものであるが、全ての金型を閉成して行なうクローズド注入法を使用してもよい。なお成形金型１４は、図１３に示すように、搬送レールからなる成形ライン２８に載置され、発泡プロセスの進行中に該ライン２８上を一方向へ搬送されるようになっている。
【０００５】
【発明が解決しようとする課題】
前述した如く発泡成形品１０が所謂アンダーカット部１２を有している場合は、成形後の製品脱型に際し次の如き不都合を生じている。すなわち前述の下型１６、上型１８および中型２０からなる三つ割式の成形金型１４では、製品となる発泡成形品１０を前記中型２０と共に下型１６から脱型させるのが基本となっている。しかるに本件の如く、アンダーカット部１２を発泡成形品１０が有する場合は、前記下型１６は該発泡成形品１０の一方の表面と、該表面の一部をなすアンダーカット部１２とを成形する必要がある（図１７参照）。このため図１８に示すように、上型１８および中型２０を下型１６に対し上昇させると、前記アンダーカット部１２の存在により発泡成形品１０は、往々にして該下型１６にそのまま残留してしまう。この状態で上型１８および中型２０が更に上昇すると、図１７に示すように該上型１８および中型２０により挟まれる部位に成形された巻込部２６が、図１８に示す過程で押し潰され、遂には図１９に示すように該巻込部２６に破れを生じてしまう重大な欠点が指摘される。
【０００６】
そこで下型１６が発泡成形品１０の表面の一部をなすアンダーカット部１２を成形するようになっている場合に、その脱型を容易化するための提案として、例えば図２０に示す入れ子構造が実用化されている。すなわち下型１６の側面には、前記アンダーカット部１２を成型する部位に臨むよう所要寸法の開口部３０が開設され、この開口部３０は該下型１６の下部外側にヒンジ３２を介して枢支した入れ子３４により開閉自在に閉成可能となっている。この入れ子３４は、螺旋バネの如き弾性押圧部材３６により常には閉成方向に弾力付勢され、その閉成状態で前記下型１６の一部となって、前記アンダーカット部１２の成形に寄与するものである。そして図２０（ａ）に示すように、入れ子３４により下型１２の開口部３０を閉成した状態で発泡成形を行なった後、得られた発泡成形品１０を脱型するには、該入れ子３４に設けたレバー３８を手動操作して、図２０（ｂ）に示す如く入れ子３４を斜め下方へ傾動させる。これにより下型１６の開口部３０が開放するので、該入れ子３４の裏面に位置している発泡成形品１０のアンダーカット部１２は金型と干渉することがなく、容易に脱型をなし得ることになる。しかし三つ割式の成形金型１４で、前述の如く下型１６に入れ子３４を設けるようにした方式では、その脱型作業に際し該入れ子３４を作業者の手でその都度開放する必要がある。これは脱型作業の合理化および省人化の要請に逆らうものであって、その自動化が強く望まれている。
【０００７】
【発明の目的】
この発明は、従来技術に内在している前述の諸欠点を好適に解決するべく提案されたものであって、アンダーカット部を有する発泡成形品を成形するための金型において、下型の側面開口部を開閉自在に閉成し、該アンダーカット部を有する発泡成形品の脱型を容易化し得る入れ子を、上型の開放動作と連繋して自動的に開放させ得る手段を提供することを目的とする。
【０００８】
【課題を解決するための手段】
前記課題を克服し、所期の目的を好適に達成するため本発明は、アンダーカット部を有する発泡成形品の成形金型であって、該発泡成形品の一方の表面および該表面の一部をなすアンダーカット部を成形する下型と、該下型に対して開閉自在に枢支され、該発泡成形品の他方の表面を成形する上型と、前記下型の側面でかつ前記アンダーカット部の成型部位に臨むよう開設した開口部と、該開口部を開閉自在に枢支され、その閉成時に前記下型の一部となって前記アンダーカット部の成形に寄与する入れ子とからなる成形金型において、
前記上型に回動自在に枢着されて常には自重で垂下し、該上型を下型に対し閉じた際に、前記閉成状態にある入れ子の側方に位置し得る付勢ロッドと、
前記入れ子に設けられて外側部に延出し、前記付勢ロッドの進入・退出を許容する溝部を形成したガイド部材とからなり、
前記上型から自重垂下する付勢ロッドは、該上型の閉成時に前記ガイド部材の溝部に位置して上方への移動自在かつ側方への移動不能に捕捉され、
前記上型の開放動作に伴って上昇する付勢ロッドは、前記溝部により側方への移動を規制される結果として、前記入れ子を外方へ強制的に付勢して前記開口部を開放し得るよう構成したことを特徴とする。
【０００９】
この場合に付勢ロッドは、上型から垂下するに従って外方へ延出する緩やかな湾曲部を有し、この湾曲部がガイド部材の溝部に当接し得るように設定するのが好ましい。またガイド部材の溝部は、その最奥部に該溝部の幅より僅かに広い切欠孔を有し、この切欠孔が付勢ロッドを上方への移動自在かつ側方への移動不能に捕捉するよう設定しておくのが好ましい。
【００１０】
【実施例】
次に、本発明に係るアンダーカット部を有する発泡成形品の成形金型につき、好適な実施例を挙げて、添付図面を参照しながら以下説明する。なお図１３〜図２０に関して説明した部材と同一の部材については、同じ参照符号で示すものとする。また実施例では、中子を備える三つ割式の成形金型に関して説明するが、この中子の存在は本発明の要旨となるものでなく、上型および下型だけからなる二つ割式の成形金型であってもよいことは勿論である。
【００１１】
実施例に係る成形金型１４は、図１に示す如く、上型１８が下型１６に対し前記成形ライン２８と交差する方向に開閉可能になっている。この上型１８には、その上面一端部に固定したボス部材４０によって回動自在に枢着され、常には自重で垂下する付勢ロッド４２が配設されている。すなわち該付勢ロッド４２は、図１に示すように、上型１８から垂下するに従って外方へ延出する緩やかな湾曲部分４２ａを有すると共に、その開放端部近傍が垂直方向に真直となるよう成形されたものであって、前記上型１８を下型１６に対して閉じた際に、閉成状態にある前記入れ子３４の側方に位置し得るようになっている。またこの状態における付勢ロッド４２の湾曲部分４２ａは、入れ子３４の上端部に設けられて外側部に延出し、該ロッド４２の進入・退出を許容するガイド部材４４（後述）の溝部４６に当接するよう構成されている。
【００１２】
前記ガイド部材４４は、図２および図３に示すように、入れ子３４の上端部から水平に外方へ延出すると共に、上型１８と下型１６との枢支部４８に向けて延出するもので、その溝部４６は枢支部４８の側に開放し、かつ開放角度が該枢支部４８に向かうにつれて次第に大きくなるよう湾曲成形されている。また溝部４６は、上型１８の下型１６に対する閉成に伴って、前記付勢ロッド４２の湾曲部分４２ａがガイド部材４４と当接あるいは若干の間隙を設けながら緩やかに係合し得るようになっている。従って溝部４６の開放端部は、付勢ロッド４２の真直部分よりも外方に位置するよう設定されている。更に該溝部４６は、その最奥部に該溝部４６の幅より僅かに広くなるよう設定した切欠孔５０が形成され、この切欠孔５０に付勢ロッド４２の湾曲部分４２ａが係合可能となっている。これによって、上型１８が下型１６に対し閉成状態にある場合は、切欠孔５０が付勢ロッド４２を上方への移動自在かつ側方への移動不能に捕捉すると共に、この側方への移動が規制される結果として、後述する如く上型１８の上昇に伴いロッド４２を介して前記入れ子３４を外方へ強制的に付勢して、下型１６に形成される前記開口部３０を開放し得るよう構成されている。
【００１３】
また上型１８の開放端部には、図１および図３に示す如く、外側端部から水平方向に所要長さの軸胴を備えた当接部材（以下「支持ローラ」という）５２が配設されている。この支持ローラ５２は、搬送レールからなる前記成形ライン２８に沿って起伏した所要形状の長尺部材（以下「支持バー」という）５４に上面から当接しており、成形ライン２８での成形金型１４の搬送に随伴して、支持ローラ５２が該支持バー５４に沿って上昇または下降し、これにより上型１８が自動的に開放および閉成するようになっている。なお前記入れ子３４は、下型１６における開口部３０の下部にヒンジ３２を介して枢支され、該入れ子３４と下型１６等の固定部位との間に介装したねじりコイルバネ等の弾性部材５６によって、開口部３０の閉成方向へ常に付勢されている。
【００１４】
【実施例の作用】
次に、実施例に係るアンダーカット部を有する発泡成形品の成形金型の使用の実際につき説明する。この成形金型１４は、図１５および図１６で説明した如く、成形時における発泡プロセスの進行中に成形ライン２８上を一方向へ搬送されるものであって、該金型１４内に前記ウレタン原液を注入した後、クリームタイムを経て原液が発泡することによりウレタンフォームが形成される。しかる後に前記上型１８を開放して所要形状の発泡成形品１０が得られる。この過程において、先ずウレタン原液が注入された成形金型１４が前記成形ライン２８で搬送されてくる。このとき上型１８に取付けた支持ローラ５２は、図４に示すように、該上型１８を閉成する高さ位置にある支持バーの水平部分に当接しながら回転移動する。なおこの図示する状態の前過程においては、成形金型１４内に注入されたウレタン原液が、搬送時に金型１４内での発泡が終了した状態となっている。従って図５に示す如く、成形金型１４内では、中型２０と下型１６および入れ子３４によって前記アンダーカット部１２が成形されている。また付勢ロッド４２は、その湾曲部分４２ａの上部がガイド部材４４の切欠孔５０に係合しており、この状態では入れ子３４が発泡成形品１０に対して密着的に当接している。
【００１５】
前記成形金型１４が成形ライン２８に沿って前進すると、図６に示すように、支持ローラ５２が支持バー５４の水平部から上方に屈曲した部分に到達し、該支持ローラ５２上方に付勢されることで上型１８が開放動作を開始する。これに伴って上昇する付勢ロッド４２は、ガイド部材４４の溝部４６により側方への移動を規制される結果として、前記入れ子３４を外方へ強制的に付勢して下型１６における前記開口部３０を開放し得るようになっている。すなわちこの付勢ロッド４２が垂直上方に上昇すると、その湾曲部分４２ａがガイド部材４４の切欠孔５０に係合した状態で上昇する。この湾曲部分４２ａは、前述したように、成形金型１４の外方に屈曲成形されているため、図７に示す如く、ガイド部材が切欠孔５０との係合状態を保持したまま、入れ子３４が弾性部材の弾力に抵してヒンジを中心に外方に回動する。なお三つ割式の成形金型１４の場合、上型１８が開放動作を開始した後に若干の時間差をおいて中型２０が開放し得るようになっているため、上型１８の上昇と共に入れ子３４が開放動作を開始する時点では、図の成形品１０が中型２０と共に下型１６に密着状態にある。また付勢ロッド４２は、上型１８に取付けた前記ボス部材４０によって回動自在に枢着されていることにより、該上型１８の動きに追従して回転し得るようになっている。
【００１６】
この位置から成形金型１４が前進し、支持ローラ５２が前記支持バー５４に沿って上方に移動することにより、図８に示すように、前記ガイド部材４４が付勢ロッド４２の湾曲部分４２ａから垂直下方に延在した部分へと移行する。この時点において付勢ロッド４２と係合するガイド部材４４が、前記開口部３０から最大に離間した位置まで回動されることにより、入れ子３４の展開動作が終了しており、上型１８は、該入れ子３４の展開位置を保持した状態で開放動作が継続されるようになっている。また前記発泡成形品１０は、前記中型２０に密着した状態で上型１８と一体的に上昇する。なお発泡成形品１０のアンダーカット部分は、入れ子３４が全開位置まで回動するのと同期して上昇するので、図９に示すように、入れ子３４と干渉することなく速やかに下型１６から脱型される。また付勢ロッド４２は、ガイド部材４４の切欠孔５０との係合が保持されており、上型１８の閉成時における垂直状態から前記ボス部材４０を中心にして所要角度だけ回転している。
【００１７】
更に金型１４が前記成形ライン２８に沿って前進することにより、図１０に示す如く、発泡成形品１０が取出される全開位置まで上型１８が回動するが、この全開位置に到る前段階において、付勢ロッド４２がガイド部材４４の垂直部分から離脱する。すなわち該ガイド部材４４は、前記中型２０が下型１６から完全に離脱する回転角度において、ガイド部材４４の前記切欠孔５０から離脱することになる。ガイド部材４４の離脱により、図１１の想像線に示す如く、展開動作の終了位置にある入れ子３４が、コイルバネ等の弾性部材５６を介して下型１６の開口部３０に回動復帰するようになっている。なお付勢ロッド４２は、前述したように、上型１８に配設されたボス部材４０に対して回動自在に軸支されているため、ガイド部材４４から離脱した後は、その自重によって鉛直下方に垂下する。
【００１８】
また発泡成形品１０を離脱させた中型２０およびこれと連動する上型１８を下型１６に閉成するに際しては、図２および図１２に示す如く、前記ボス部材４０を介して回転自在に配設された付勢ロッド４２が、その垂下状態を保持したまま上型１８の閉成動作に合わせてガイド部材４４の開放端部から係合される。このガイド部材４４は、前述したように、付勢ロッド４２の湾曲部分４２ａがガイド部材４４と当接あるいは若干の間隙を設けながら緩やかに係合し得るよう湾曲成形されているため、図に示すように、付勢ロッド４２が溝部４６に沿って速やかに侵入し、前記切欠孔５０と係合するよう構成されている。
【００１９】
【発明の効果】
以上説明した如く、本発明に係るアンダーカット部を有する発泡成形品の成形金型によれば、上型に対して回転自在に取付けた付勢ロッドと、入れ子の外側面に取付けられて該付勢ロッドと係合するガイド部材とによって、アンダーカット部の脱型を容易になし得る入れ子の開放動作を、上型の開放動作と連動して行なうことができる。しかも上型の開放動作は、上型に配設された当接部材を、成形金型の搬送ラインに沿って起伏する長尺部材に当接させることにより、該成形金型が一方向へ搬送されるに伴なって自動的に行な得るよう構成されており、発泡成形品の脱型作業の合理化および省人化に寄与し得る、等の利点を有する。
【図面の簡単な説明】
【図１】本発明の実施例に係るアンダーカット部を有する発泡成形品の成形金型を示す斜視図である。
【図２】本発明に係る発泡成形品の成形金型において、上型を閉成する状態を示す斜視図である。
【図３】本発明に係る発泡成形品の成形金型を示す平面図である。
【図４】本発明に係る発泡成形品の成形金型において、上型を開放する直前の状態を示す側面図である。
【図５】本発明に係る発泡成形品の成形金型において、シートクッションのアンダーカット部を示す要部縦断面図である。
【図６】本発明に係る発泡成形品の成形金型において、上型が開放動作を開始した状態を示す側面図である。
【図７】本発明に係る発泡成形品の成形金型において、上型の開放動作に伴って入れ子が回動を開始した状態を示す要部縦断面図である。
【図８】本発明に係る発泡成形品の成形金型において、上型が更に開放した状態を示す側面図である。
【図９】本発明に係る発泡成形品の成形金型において、入れ子が全開した状態を示す要部縦断面図である。
【図１０】本発明に係る発泡成形品の成形金型であって、上型が全開した状態を示す側面図である。
【図１１】本発明に係る発泡成形品の成形金型であって、上型に配設された付勢ロッドが入れ子のガイド部材から離脱して、下型に復帰する状態を示す要部縦断面図である。
【図１２】本発明に係る発泡成形品の成形金型であって、上型が閉成する際に付勢ロッドが入れ子のガイド部材に係合する状態を示す要部縦断面図である。
【図１３】従来技術に係るアンダーカット部を有する発泡成形品の成形金型を示す斜視図である。
【図１４】発泡成形品の成形金型で成型されたシートクッションを示す斜視図である。
【図１５】従来技術に係る発泡成形品の成形金型であって、シートクッションを成形する状態を示す縦断側面図である。
【図１６】従来技術に係る発泡成形品の成形金型であって、上型が開放した状態を示す縦断側面図である。
【図１７】従来技術に係る発泡成形品の成形金型であって、シートクッションのアンダーカット部を示す要部縦断面図である。
【図１８】従来技術に係る発泡成形品の成形金型であって、下型に残留したシートクッションの一部が、開放動作を開始した中型によって圧潰されている状態を示す要部縦断面図である。
【図１９】従来技術に係る発泡成形品の成形金型であって、中型の開放動作によりシートクッションの一部が破損した状態を示す要部縦断面図である。
【図２０】従来技術に係る発泡成形品の成形金型であって、下型に配設した入れ子の閉成時と開放時を示す要部縦断面図である。
【符号の説明】
１０発泡成形品
１２アンダーカット部
１６下型
１８上型
３０開口部
３４入れ子
４２付勢ロッド
４４ガイド部材
４６溝部[0001]
[Industrial applications]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die for a foam molded article having an undercut portion, and more particularly, to a foam molding having an undercut portion by closing a side opening of a lower mold in the molding die so as to be freely opened and closed. The present invention relates to a proposal in which a nest for facilitating release of a product can be opened in connection with an opening operation of an upper die in the molding die.
[0002]
[Prior art]
An occupant seat used for a vehicle such as an automobile generally has a base material of a cushion material obtained by foaming and molding urethane resin into a required shape. This occupant seat is configured by combining a separately formed backrest and a seat. For example, the foam molded product 10 serving as a backrest is formed into an external shape as shown in FIG. 14, and its central longitudinal section cut along the line AA has the shape shown in FIG. 15. A cross section of the foam molded product 10 taken along the line BB has a shape shown in FIG. 17 (only the right half portion is shown). In this case, the foam molded product 10 is integrally formed with a protruding portion 12 slightly extending outward from the backrest portion so that both sides of the body of the occupant can be held from the left and right. I have. As shown in the figure, since the projecting portion 12 has an overhang portion inclined with respect to the inner surface of the lower mold 16 in the molding die 14, it is generally called an undercut portion, and is often referred to as an undercut portion. This hinders the removal of the foam molded product 10 from the mold.
[0003]
In FIGS. 13 and 15, the molding die 14 is provided with a lower die 16 for molding the front side of the foam molded product 10, and is provided so as to be openable and closable with respect to the lower die 16, and is on the back surface side of the foam molded product 10. The foam mold 10 includes an upper mold 18 for molding a portion, and a middle mold 20 which is provided to be openable and closable with respect to the upper mold 18 and has an indentation 24 for molding a lip 22 on the back surface of the foam molded article 10. The lip portion 22 covers an elastic wire (neither is shown) stretched over the frame when a pipe frame serving as a skeleton of a sheet is provided on the foam molded product 10.
[0004]
At the time of foam molding, a urethane stock solution is injected into the bottom surface of the lower mold 16 by an injector (not shown), the middle mold 20 is closed to the lower mold 16 to a predetermined position, and then the upper mold 18 is moved to the middle mold 20. After closing (mold clamping), the foaming reaction of the urethane stock solution proceeds. Here, the urethane stock solution is composed of, for example, a mixed and stirred solution of a first solution containing a polyether polyol as a main component, a foaming agent, a catalyst, a cross-linking agent, and the like, and a second solution made of polyisocyanate. Then, when the cream time at which the reaction mixture is saturated elapses, the urethane stock solution becomes a urethane foam while foaming and fills the inside of the molding die 14. When the foam molding is completed, as shown in FIG. 16, the upper mold 18 is opened to the lower mold 16 (at this time, the upper mold 18 is also opened to the middle mold 20). By opening, the foam molded article 10 having the required shape including the lip portion 22 is molded. Although the above description is based on the so-called open injection method, a closed injection method in which all the molds are closed may be used. As shown in FIG. 13, the molding die 14 is mounted on a molding line 28 composed of a conveying rail, and is conveyed in one direction on the line 28 during the foaming process.
[0005]
[Problems to be solved by the invention]
When the foam molded article 10 has a so-called undercut portion 12 as described above, the following inconveniences occur in removing the product after molding. That is, in the three-part molding die 14 including the lower die 16, the upper die 18, and the middle die 20, the foam molded product 10 to be a product is basically released from the lower die 16 together with the middle die 20. ing. However, when the foam molded article 10 has the undercut section 12 as in the present case, the lower mold 16 molds one surface of the foam molded article 10 and the undercut section 12 forming a part of the surface. (See FIG. 17). Therefore, as shown in FIG. 18, when the upper die 18 and the middle die 20 are raised with respect to the lower die 16, the foam molded product 10 often remains as it is due to the presence of the undercut portion 12. Would. When the upper mold 18 and the middle mold 20 further rise in this state, the winding portion 26 formed at a portion sandwiched between the upper mold 18 and the middle mold 20 as shown in FIG. 17 is crushed in the process shown in FIG. Finally, as shown in FIG. 19, there is pointed out a serious disadvantage that the winding portion 26 is broken.
[0006]
Therefore, in a case where the lower die 16 is to form the undercut portion 12 which forms a part of the surface of the foam molded product 10, as a proposal for facilitating the demolding, for example, a nested structure shown in FIG. Has been put to practical use. That is, an opening 30 having a required size is opened on a side surface of the lower mold 16 so as to face a portion where the undercut portion 12 is molded. The opening 30 is pivotally connected to a lower outside of the lower mold 16 via a hinge 32. The nest 34 supported can be opened and closed freely. The insert 34 is always elastically urged in the closing direction by an elastic pressing member 36 such as a helical spring, and in the closed state, becomes a part of the lower die 16 and contributes to the formation of the undercut portion 12. To do. Then, as shown in FIG. 20 (a), after performing foam molding in a state where the opening 30 of the lower mold 12 is closed by the nest 34, to remove the obtained foam molded product 10 from the nest, By manually operating a lever 38 provided on the nest 34, the insert 34 is tilted obliquely downward as shown in FIG. As a result, the opening 30 of the lower die 16 is opened, so that the undercut portion 12 of the foam molded product 10 located on the back surface of the insert 34 does not interfere with the die and can be easily removed. Will be. However, in the method in which the nest 34 is provided on the lower mold 16 by the three-part molding die 14 as described above, it is necessary to open the nest 34 by the operator's hand each time when removing the mold. . This goes against the demands for rationalization and labor saving of the demolding work, and there is a strong demand for automation.
[0007]
[Object of the invention]
The present invention has been proposed in order to preferably solve the above-described drawbacks inherent in the prior art, and a mold for molding a foam molded article having an undercut portion is provided with a side surface of a lower mold. It is an object of the present invention to provide means for automatically opening a nest capable of opening and closing an opening part and facilitating demolding of a foam molded article having the undercut part in conjunction with an opening operation of an upper die. Aim.
[0008]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION In order to overcome the above problems and appropriately achieve the intended purpose, the present invention relates to a molding die for a foamed molded product having an undercut portion, wherein one surface of the foamed molded product and a part of the surface are provided. A lower mold for forming an undercut portion, an upper mold pivotally supported on the lower mold so as to be openable and closable, and forming the other surface of the foam molded article; and a side face of the lower mold and the undercut. An opening formed so as to face the molding part of the part, and a nest which is pivotally supported so as to be openable and closable and which becomes a part of the lower die when the opening is closed and contributes to the formation of the undercut part. In the molding die,
An urging rod which is rotatably pivotally attached to the upper mold and always hangs down by its own weight, and which can be positioned on the side of the nest in the closed state when the upper mold is closed with respect to the lower mold; ,
A guide member provided in the nest and extending to the outer side, and formed with a groove portion that allows entry and exit of the urging rod,
An urging rod that hangs from the upper mold by its own weight is captured in the groove of the guide member at the time of closing the upper mold so as to be movable upward and immovable laterally,
The urging rod that rises with the opening operation of the upper die, as a result of being restricted from moving laterally by the groove, forcibly urges the nest outward and opens the opening. It is characterized in that it is configured to obtain.
[0009]
In this case, it is preferable that the urging rod has a gently curved portion extending outward as it hangs down from the upper die, and is preferably set so that the curved portion can contact the groove of the guide member. Further, the groove of the guide member has a notch hole slightly wider than the width of the groove at the innermost portion thereof, and the notch hole urges the urging rod upward and movably to the side. It is preferable to set it.
[0010]
【Example】
Next, a molding die for a foam molded article having an undercut portion according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments. The same members as those described with reference to FIGS. 13 to 20 are denoted by the same reference numerals. Further, in the embodiment, a three-part mold having a core will be described, but the existence of the core is not the gist of the present invention, and a two-part mold composed of only an upper mold and a lower mold is described. It is needless to say that the molding die may be used.
[0011]
As shown in FIG. 1, the molding die 14 according to the embodiment is configured such that the upper die 18 can be opened and closed with respect to the lower die 16 in a direction crossing the molding line 28. The upper die 18 is provided with a biasing rod 42 which is rotatably pivoted by a boss member 40 fixed to one end of the upper surface thereof and which always hangs down by its own weight. That is, as shown in FIG. 1, the urging rod 42 has a gentle curved portion 42a extending outward as it hangs down from the upper die 18, and the vicinity of its open end is straightened vertically. When the upper mold 18 is closed with respect to the lower mold 16, the upper mold 18 can be positioned on the side of the nest 34 in a closed state. In this state, the curved portion 42a of the urging rod 42 is provided at the upper end of the nest 34 and extends to the outside, and abuts on a groove 46 of a guide member 44 (described later) that allows the rod 42 to enter and exit. It is configured to touch.
[0012]
As shown in FIGS. 2 and 3, the guide member 44 horizontally extends outward from the upper end of the nest 34 and extends toward a pivot 48 between the upper die 18 and the lower die 16. The groove 46 is formed in a curved shape so as to open toward the pivot 48 and to have an opening angle gradually increasing toward the pivot 48. The groove portion 46 is formed so that the curved portion 42a of the urging rod 42 can abut the guide member 44 or gently engage with the guide member 44 while closing the upper die 18 with the lower die 16. Has become. Therefore, the open end of the groove 46 is set to be located outside the straight part of the urging rod 42. Further, a notch hole 50 is formed at the innermost portion of the groove portion 46 so as to be slightly wider than the width of the groove portion 46, and the curved portion 42a of the urging rod 42 can be engaged with the notch hole 50. ing. Accordingly, when the upper die 18 is in the closed state with respect to the lower die 16, the cutout hole 50 catches the urging rod 42 so as to be movable upward and immovable laterally, and to the side. As a result, the nest 34 is forcibly urged outward via the rod 42 as the upper die 18 rises, as described later, so that the opening 30 formed in the lower die 16 is formed. Are configured to be open.
[0013]
As shown in FIGS. 1 and 3, a contact member (hereinafter referred to as a “support roller”) 52 having a shaft barrel of a required length in the horizontal direction from the outer end is disposed at the open end of the upper die 18. Is established. The support roller 52 is in contact with an elongate member (hereinafter referred to as a “support bar”) 54 of a required shape which is undulated along the molding line 28 formed of a conveying rail from an upper surface. Along with the transport of 14, the support roller 52 moves up or down along the support bar 54, so that the upper die 18 automatically opens and closes. The nest 34 is pivotally supported below the opening 30 in the lower mold 16 via a hinge 32, and an elastic member 56 such as a torsion coil spring interposed between the nest 34 and a fixed portion of the lower mold 16 or the like. Thus, the opening 30 is always urged in the closing direction.
[0014]
Operation of the embodiment
Next, the actual use of a molding die for a foam molded article having an undercut portion according to the embodiment will be described. As described with reference to FIGS. 15 and 16, the molding die 14 is conveyed in one direction on a molding line 28 during a foaming process during molding. After injecting the undiluted solution, the undiluted solution foams through the cream time to form urethane foam. Thereafter, the upper mold 18 is opened to obtain the foam molded article 10 having a required shape. In this process, first, the molding die 14 into which the urethane stock solution has been injected is conveyed through the molding line 28. At this time, as shown in FIG. 4, the support roller 52 attached to the upper die 18 rotates while abutting on a horizontal portion of the support bar at a height position for closing the upper die 18. In the process before the state shown in the figure, the urethane stock solution injected into the molding die 14 is in a state where foaming in the die 14 at the time of transportation is completed. Therefore, as shown in FIG. 5, in the molding die 14, the undercut portion 12 is molded by the middle die 20, the lower die 16 and the insert 34. The upper part of the curved portion 42a of the urging rod 42 is engaged with the cutout hole 50 of the guide member 44. In this state, the insert 34 is in close contact with the foam molded product 10.
[0015]
When the molding die 14 advances along the molding line 28, as shown in FIG. 6, the support roller 52 reaches a portion bent upward from a horizontal portion of the support bar 54, and is urged above the support roller 52. Then, the upper die 18 starts the opening operation. The urging rod 42 which rises with this is forcibly urged the nest 34 outward as a result of the lateral movement being restricted by the groove 46 of the guide member 44, and The opening 30 can be opened. That is, when the urging rod 42 rises vertically upward, the curved portion 42 a rises while engaging with the notch 50 of the guide member 44. As described above, since the curved portion 42a is bent outwardly of the molding die 14, the guide member 34 retains the engagement state with the notch hole 50 as shown in FIG. Rotate outwardly about the hinge against the elasticity of the elastic member. In the case of the three-piece molding die 14, the middle die 20 can be opened with a slight time difference after the upper die 18 starts the opening operation. At the time when the opening operation starts, the molded article 10 in the figure is in close contact with the lower mold 16 together with the middle mold 20. The urging rod 42 is rotatably pivoted by the boss member 40 attached to the upper die 18 so that it can rotate following the movement of the upper die 18.
[0016]
As the molding die 14 advances from this position and the support roller 52 moves upward along the support bar 54, the guide member 44 is moved from the curved portion 42a of the urging rod 42 as shown in FIG. It transitions to a vertically extending portion. At this point, the guide member 44 engaged with the urging rod 42 is rotated to the position farthest from the opening 30 to complete the deployment operation of the nest 34. The opening operation is continued with the nest 34 kept in the deployed position. Further, the foam molded article 10 is integrally lifted with the upper mold 18 in a state of being in close contact with the middle mold 20. Since the undercut portion of the foam molded article 10 rises in synchronization with the rotation of the insert 34 to the fully opened position, as shown in FIG. Typed. The urging rod 42 is held in engagement with the notch hole 50 of the guide member 44, and rotates from the vertical state when the upper die 18 is closed by a required angle about the boss member 40 from the vertical state. .
[0017]
When the mold 14 further advances along the molding line 28, as shown in FIG. 10, the upper mold 18 pivots to a fully open position where the foam molded article 10 is taken out, but before reaching the fully open position. In a stage, the biasing rod 42 is disengaged from the vertical portion of the guide member 44. That is, the guide member 44 separates from the cutout hole 50 of the guide member 44 at a rotation angle at which the middle mold 20 completely separates from the lower mold 16. With the detachment of the guide member 44, as shown by the imaginary line in FIG. 11, the insert 34 at the end position of the unfolding operation returns to the opening 30 of the lower die 16 via the elastic member 56 such as a coil spring. Has become. As described above, since the urging rod 42 is rotatably supported by the boss member 40 disposed on the upper die 18, after being separated from the guide member 44, the urging rod 42 is vertically moved by its own weight. Hang downward.
[0018]
When closing the middle mold 20 from which the foam molded article 10 has been detached and the upper mold 18 interlocking with the middle mold 20 to the lower mold 16, as shown in FIGS. 2 and 12, the middle mold 20 is rotatably arranged via the boss member 40. The provided urging rod 42 is engaged from the open end of the guide member 44 in accordance with the closing operation of the upper die 18 while maintaining the hanging state. As described above, the guide member 44 is curved and formed so that the curved portion 42a of the urging rod 42 can abut or loosely engage with the guide member 44 while providing a slight gap. Thus, the urging rod 42 is configured to quickly enter along the groove 46 and engage with the cutout hole 50.
[0019]
【The invention's effect】
As described above, according to the foaming mold having the undercut portion according to the present invention, the urging rod rotatably attached to the upper mold and the urging rod attached to the outer surface of the nest. With the guide member engaged with the urging rod, the opening operation of the nest that can easily remove the undercut portion can be performed in conjunction with the opening operation of the upper mold. In addition, the opening operation of the upper mold is performed by bringing the contact member provided on the upper mold into contact with the long member that rises and falls along the conveying line of the molding die, so that the molding die is transported in one direction. It is configured to be able to carry out automatically as it is performed, and has the advantage that it can contribute to the rationalization of the demolding operation of the foam molded article and labor saving.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a molding die for a foam molded article having an undercut portion according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a state in which an upper mold is closed in a molding die for a foam molded article according to the present invention.
FIG. 3 is a plan view showing a molding die for a foam molded product according to the present invention.
FIG. 4 is a side view showing a state immediately before an upper mold is opened in a molding die for a foam molded article according to the present invention.
FIG. 5 is a longitudinal sectional view of an essential part showing an undercut portion of a seat cushion in a molding die for a foam molded product according to the present invention.
FIG. 6 is a side view showing a state where the upper mold has started the opening operation in the molding die for the foam molded article according to the present invention.
FIG. 7 is a vertical cross-sectional view of a main part of the molding die for a foam molded product according to the present invention, showing a state where the nest has started to rotate with the opening operation of the upper die.
FIG. 8 is a side view showing a state in which the upper mold is further opened in the molding die for a foam molded article according to the present invention.
FIG. 9 is a longitudinal sectional view of an essential part showing a state in which a nest is fully opened in a molding die for a foam molded article according to the present invention.
FIG. 10 is a side view showing a molding die of a foam molded product according to the present invention, showing a state where an upper die is fully opened.
FIG. 11 is a molding longitudinal section of a foaming molded product according to the present invention, showing a state in which an urging rod disposed on an upper mold is separated from a nested guide member and returned to a lower mold. FIG.
FIG. 12 is a main part longitudinal cross-sectional view of a molding die for a foam molded product according to the present invention, showing a state where an urging rod is engaged with a nested guide member when the upper die is closed.
FIG. 13 is a perspective view showing a molding die of a foam molded article having an undercut portion according to the related art.
FIG. 14 is a perspective view showing a seat cushion molded by a molding die of a foam molded product.
FIG. 15 is a longitudinal sectional side view showing a state in which a seat cushion is molded, which is a molding die for a foam molded product according to the prior art.
FIG. 16 is a longitudinal sectional side view showing a molding die of a foam molded product according to the prior art, showing a state where an upper die is opened.
FIG. 17 is a main part longitudinal sectional view showing an undercut portion of a seat cushion in a molding die for a foam molded product according to a conventional technique.
FIG. 18 is a main part longitudinal sectional view showing a state in which a part of a seat cushion remaining in a lower mold is crushed by a middle mold that has started an opening operation, which is a molding die for a foam molded product according to a conventional technique. It is.
FIG. 19 is a main part longitudinal sectional view showing a state in which a part of a seat cushion is broken by an opening operation of a middle mold in a molding die of a foam molded product according to a conventional technique.
FIG. 20 is a main part longitudinal cross-sectional view of a molding die for a foam molded product according to the prior art, showing when a nest disposed in a lower die is closed and opened.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Foam molded product 12 Undercut part 16 Lower die 18 Upper die 30 Opening 34 Nesting 42 Urging rod 44 Guide member 46 Groove

Claims

A molding die for a foam molded product (10) having an undercut portion (12), wherein an undercut portion (12) forming one surface of the foam molded product (10) and a part of the surface is formed. A lower mold (16), an upper mold (18) pivotally supported on the lower mold (16) to open and close, and molding the other surface of the foam molded article (10); and the lower mold (16) An opening (30) opened on the side surface of the undercut part (12) and facing the molding part of the undercut part (12), and the opening (30) is pivotally supported so as to be openable and closable. And a nest (34) contributing to the formation of the undercut portion (12) as a part of
The upper mold (18) is rotatably connected to the upper mold (18) and always hangs down by its own weight. When the upper mold (18) is closed with respect to the lower mold (16), the nest (34) is in the closed state. )), A biasing rod (42) which may be located on the side of
A guide member (44) provided in the nest (34), extending outwardly, and forming a groove (46) for allowing the urging rod (42) to enter and exit;
When the upper die (18) is closed, the urging rod (42) which is suspended from the upper die (18) is located in the groove (46) of the guide member (44) and is movable upward and sideward. Is trapped immovable towards
The urging rod (42), which rises with the opening operation of the upper die (18), forcibly forces the nest (34) outward as a result of being restricted from moving laterally by the groove (46). A molding die for a foam molded article having an undercut portion, characterized in that the opening portion (30) is configured to be capable of being urged to open the opening (30).

The urging rod (42) has a gentle curved portion (42a) extending outward as it hangs down from the upper die (18), and the curved portion (42a) is formed by a groove (42) of the guide member (44). The molding die for a foam molded article having an undercut portion according to claim 1, wherein the molding die can be brought into contact with (46).

The groove (46) of the guide member (44) has a notch (50) at the innermost portion thereof slightly wider than the width of the groove (46), and the notch (50) is formed by the urging rod ( 2. A molding die for a foam molded article having an undercut portion according to claim 1, wherein 42a) is captured so as to be movable upward and immovable laterally.

The guide member (44) extends toward a pivot (48) between the upper mold (18) and the lower mold (16), and the groove (46) in the guide member (44) is formed on the pivot (48). The molding die for a foam molded article having an undercut portion according to claim 1, wherein the mold is opened to the side and the opening angle is curved so as to gradually increase toward the pivot portion (48).

The nest (34) is hingedly connected to a lower portion of the opening (30) in the lower mold (16), and is an elastic member interposed between the nest (34) and a fixed portion of the lower mold (16) and the like. The molding die for a foam molded article having an undercut portion according to claim 1, wherein the insert (34) is constantly urged in the closing direction of the opening (30) by (56).

The molding die is conveyed in one direction on a molding line (28) during a foaming process during molding, and the upper die (18) intersects with the lower die (16) in the conveying direction. An abutment member (54), which can be opened and closed in the direction and is undulating along the forming line (28), is provided on the upper die (18) and extends outwardly, 52) is contacted from above, and as the molding die is conveyed in one direction, the contact member (52) is urged upward by the long member (54), and the upper mold ( The mold according to claim 1, wherein the mold (18) is opened to the lower mold (16).

The foam having an undercut portion according to claim 1, further comprising a middle mold (20) arranged to be openable and closable with respect to the upper mold (18), and for forming a lip (22) on the foam molded article (10). Mold for forming molded products.