JP3779593B2

JP3779593B2 - Rotating atomizing head

Info

Publication number: JP3779593B2
Application number: JP2001336747A
Authority: JP
Inventors: 将俊近
Original assignee: ABB KK
Current assignee: ABB KK
Priority date: 2000-11-30
Filing date: 2001-11-01
Publication date: 2006-05-31
Anticipated expiration: 2021-11-01
Also published as: JP2002224593A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば車体等の被塗物に塗装を行なう塗装機に用いて好適な回転霧化頭に関する。
【０００２】
【従来の技術】
一般に、自動車の車体等の被塗物に塗装を行なうときには、例えば塗着効率、塗装仕上り等の面で有利な回転霧化頭型塗装装置が多用されている。そして、この回転霧化頭型塗装装置に用いられる回転霧化頭は、霧化頭本体とハブ部材とによって大略構成されている。
【０００３】
例えば、特開平９−２３４３９３号公報等に記載された回転霧化頭型塗装装置では、回転霧化頭の霧化頭本体は、後端側がエアモータの回転軸に取付けるための回転軸取付部となり、該回転軸取付部から前側に向けて筒形ないしベル形に形成されている。また、霧化頭本体の前部側には、放出端縁に向けて塗料を薄膜化する塗料薄膜化面が形成され、該塗料薄膜化面の奥部側には塗料溜りが設けられている。さらに、霧化頭本体には、塗料薄膜化面と塗料溜りとの間に位置して段付状のハブ嵌合段部が設けられている。
【０００４】
一方、回転霧化頭のハブ部材は、塗料溜りの前方を覆うようにハブ嵌合段部に嵌合して取付けられるもので、該ハブ部材の外周側には、塗料溜りに供給された塗料を霧化頭本体の塗料薄膜化面に流出させるための塗料流出孔が多数個穿設されている。
【０００５】
また、霧化頭本体に形成されたハブ嵌合段部の内周面とハブ部材の外周面のいずれか一方側には、Ｏリングが嵌着され、該Ｏリングの弾性力によってハブ嵌合段部に対しハブ部材を取付け、取外し可能に保持する構成としている。
【０００６】
ここで、通常色替などにより回転霧化頭を洗浄するときには、塗装装置に回転霧化頭を取付けたままで、その洗浄を行う所謂自動洗浄を行っている。即ち、自動洗浄とは、回転霧化頭を高速で回転させた状態で、フィードチューブから霧化頭本体の塗料溜りにシンナ等の洗浄流体を供給し、この洗浄流体により、塗料溜り、ハブ部材の前面、ハブ部材の後面、塗料流出孔、塗料薄膜化面等の塗料接液部に付着している塗料を洗い流すものである。しかし、この自動洗浄を行っても、これらの塗料接液部には、塗装中に塗料に含まれる顔料成分等が僅かずつ付着し、堆積する。このため、塗料接液部に顔料等が固着してしまった場合には、回転霧化頭を回転軸から取外し、ブラシ等を用いて手作業で塗料接液部に付着した顔料等の固着物を除去している。
【０００７】
【発明が解決しようとする課題】
ところで、前述した特開平９−２３４３９３号公報等による回転霧化頭によると、ハブ部材は、Ｏリングの弾性力を利用しハブ嵌合段部に取付け、取外し可能に保持する構成としている。この場合、Ｏリングは、押圧することにより容易に変形する程度の弾性を有している。このため、回転霧化頭を例えば４００００ｒｐｍ以上の高速で回転させた場合には、Ｏリングに作用する遠心力により該Ｏリングの内径寸法が増大してしまう。
【０００８】
これに対し、霧化頭本体とハブ部材は、一般的にアルミニウム合金、ステンレス合金、硬質な樹脂材料等を用いて形成されている。従って、回転霧化頭を高速回転させて遠心力が作用した場合でも、霧化頭本体とハブ部材はＯリングの変形量に比較して非常に小さく変形するだけである。
【０００９】
これらのことにより、回転霧化頭を高速回転させたときには、Ｏリングだけが遠心力によって拡径することになるから、該Ｏリングはハブ部材を保持することができなくなる。この結果、Ｏリングによるハブ部材の保持力が低下し、該ハブ部材がハブ嵌合段部内でがたつきを生じる虞れがあるという問題がある。
【００１０】
また、Ｏリングは、霧化頭本体とハブ部材の着脱作業を繰り返すと、劣化して弾性力が低下する。この状態で回転霧化頭を高速回転させると、Ｏリングは、回転霧化頭を確実に支持することができなくなり、該回転霧化頭の回転バランスが不安定になってしまう。さらに、霧化頭本体とハブ部材の着脱作業を繰り返すと、Ｏリングは、相手側の部材と擦れ合って損傷するから、頻繁な交換を要するという問題がある。
【００１１】
また、色替等により回転霧化頭を自動洗浄しても、霧化頭本体のハブ嵌合段部とハブ部材の外周面との間の隙間には、塗装中に塗料流出孔から塗料が入り込んで塗料中の顔料等が堆積し、固着する。従って、この隙間に固着した顔料等の固着物を除去するためには、ハブ部材の後部を押して霧化頭本体からハブ部材を取外す必要がある。このような場合、顔料等の固着物は、隙間に固まってしまい、くさびと同様の作用をするから、ハブ部材は容易に取外すことができないという問題がある。しかも、ハンマー等を用いてハブ部材の後部に強い力を加えて、霧化頭本体からハブ部材を無理に取外そうとすると、霧化頭本体のハブ嵌合段部とハブ部材の外周面との嵌合面が損傷するという問題がある。
【００１２】
一方、ハブ部材には、多数の塗料流出孔が設けられている。しかし、これらの塗料流出孔は、塗料溜りから塗料薄膜化面に塗料を均一に流出する必要があるため、その径寸法は小さく、周方向に多数個列設されている。従って、塗料流出孔を塗料が通過するときに、塗料中の顔料成分等が塗料流出孔の内面に付着して堆積し、徐々に塗料流出孔の径寸法を小さくしてしまう。
【００１３】
この結果、各塗料流出孔の径寸法は、塗料の堆積によってばらつきを生じるから、該各塗料流出孔から塗料薄膜化面に流出する塗料は、その流量が安定せず、塗料薄膜化面では塗料を均一に薄膜化することができなくなる。このため、放出端縁から放出された塗料粒子が不揃いとなり、塗装品質の低下を招くという問題がある。
【００１４】
しかも、塗料流出孔の径寸法が小さくなると、塗料が流出されずに塗料溜りに充満してしまうから、塗料溜りから溢れる塗料が回転軸等の隙間に流れ込んでしまい、エアモータに悪影響を与えるという問題がある。
【００１５】
そこで、従来技術では、金属材料からなる細い棒状（針状）の道具を用い、この棒を多数個の塗料流出孔に１個ずつ通し、該各塗料流出孔に堆積して固着した塗料を除去している。このため、固着した塗料の除去作業に非常に多くの手間を要してしまい、作業性の低下を招くという問題がある。
【００１６】
本発明は上述した従来技術の問題に鑑みなされたもので、本発明の目的は、霧化頭本体とハブ部材とを容易に組立、分解することができるようにした回転霧化頭を提供することにある。
【００１７】
また、本発明の他の目的は、高速回転時でもハブ嵌合凹溝内にハブ部材を確実に保持することができるようにした回転霧化頭を提供することにある。
【００１８】
さらに、本発明の他の目的は、塗料通路に固着した塗料中の顔料等の固着物を簡単に除去することができるようにした回転霧化頭を提供することにある。
【００１９】
【課題を解決するための手段】
本発明による回転霧化頭は、筒形ないしベル形に形成され、後端側が回転軸に取付けるための回転軸取付部となり、内周面の前側が放出端縁に向けて塗料を薄膜化する塗料薄膜化面となると共に奥部側が塗料溜りとなった霧化頭本体と、前記塗料溜りの前方を覆うように該霧化頭本体に着脱可能に取付けられたハブ部材とからなる。
【００２０】
そして、上述した課題を解決するために、本発明の請求項１の発明が採用する構成の特徴は、霧化頭本体には、塗料溜りと塗料薄膜化面との間の内周面に全周に亘って凹溝状に形成されたハブ嵌合凹溝を設け、ハブ部材は、霧化頭本体の内周面のうち該ハブ嵌合凹溝の前端と塗料薄膜化面との間に位置する部位の内径に比較して小径な円板状体からなる蓋部と、該蓋部から軸方向の後側に延びて設けられ先端部が弾性変形しながら前記ハブ嵌合凹溝に係合、離脱可能に嵌合する複数本の脚部と、隣合う各脚部間に位置して設けられた複数個の切欠溝とにより構成し、ハブ部材の各脚部を前記ハブ嵌合凹溝に嵌合したときには、前記ハブ嵌合凹溝と各切欠溝との間に複数の孔状塗料通路を形成すると共に、霧化頭本体の内周面と蓋部の外周面との間に環状塗料通路を形成する構成としたことにある。
【００２１】
このように構成したことにより、霧化頭本体の塗料溜りを覆うようにハブ部材をあてがい、該ハブ部材を霧化頭本体内に押込むと、該ハブ部材の各脚部は、それぞれが独立しているから霧化頭本体の内周面で径方向の内側に比較的容易に弾性変形し、ハブ嵌合凹溝で拡径して当該ハブ嵌合凹溝に嵌合する。これにより、ハブ部材は、各脚部の弾性力によってハブ嵌合凹溝に係合し抜止め状態に保持される。そして、回転霧化頭を高速回転させたときには、ハブ部材の各脚部は、遠心力によって拡径しようとするから、ハブ嵌合凹溝に強く押付けられ、ハブ部材の保持状態を維持する。
【００２２】
また、ハブ部材は、ハブ嵌合凹溝に嵌合した状態で、各切欠溝とハブ嵌合凹溝との間に孔状塗料通路を形成すると共に、霧化頭本体の内周面のうちハブ嵌合凹溝の前端と塗料薄膜化面との間に位置する部位と蓋部の外周面との間に環状塗料通路を形成するから、塗装を行う場合には、塗料溜りに塗料を供給することにより、塗料は該塗料溜りから各孔状塗料通路と環状塗料通路を通って塗料薄膜化面に流出し、放出端縁から塗料粒子となって飛行し、被塗物に塗装される。
【００２３】
一方、各孔状塗料通路、環状塗料通路等に堆積して固着した塗料中の顔料等の固着物を除去する場合には、霧化頭本体の回転軸取付部側からハブ部材の後面を前側に押圧する。これにより、ハブ嵌合凹溝と脚部との隙間に固着物が固着している場合でも、ハブ部材を霧化頭本体内に押込んだときと同様に、各脚部が比較的容易に弾性変形するから、該ハブ部材をハブ嵌合凹溝から取外すことができる。そして、霧化頭本体からハブ部材を取外した状態では、孔状塗料通路は、ハブ部材の切欠溝と霧化頭本体のハブ嵌合凹溝とに分割されるから、ブラシ等を用いて切欠溝、ハブ嵌合凹溝に固着した顔料等の固着物を容易に除去することができる。また、霧化頭本体の内周面、ハブ部材の塗料受面等の塗料接液部に堆積し固着した固着物も容易に除去することができる。
【００２４】
請求項２の発明によると、各脚部と切欠溝は蓋部の外周側に交互に形成し、各孔状塗料通路は各切欠溝とハブ嵌合凹溝との間に独立して形成する構成としたことにある。
【００２５】
このように構成したことにより、塗料溜りに供給された塗料は各孔状塗料通路から均一に流出し、環状塗料通路に流出する。
【００２６】
請求項３の発明によると、環状塗料通路は、霧化頭本体の内周面とハブ部材の蓋部外周面との間に全周に亘って円環状に形成したことにある。
【００２７】
このように構成したことにより、各孔状塗料通路を通過した塗料は、環状塗料通路を流れて塗料薄膜化面に供給される。
【００２８】
請求項４の発明によると、各脚部は、蓋部の位置から先端部の方向に離間するに従って径方向外側に向けて拡径する拡径脚部として形成したことにある。
【００２９】
このように構成したことにより、各脚部は、その先端部が最も径方向の外側に位置しているから、ハブ部材を霧化頭本体内に押込んだときには、各脚部の先端部をハブ嵌合凹溝に確実に嵌合することができる。
【００３０】
請求項５の発明によると、霧化頭本体のハブ嵌合凹溝と内周面との間の境界部は、滑らかな円弧面として形成したことにある。
【００３１】
このように構成したことにより、塗料等が塗料溜りから塗料薄膜化面に向けてハブ嵌合凹溝を乗り越えるように流れるときに、円弧面はこの塗料等を飛散させることなく、円滑に流通することができる。
【００３２】
請求項６の発明によると、環状塗料通路は、後側から前側に向けて漸次径寸法が大きくなる環状塗料通路として形成したことにある。
【００３３】
このように構成したことにより、霧化頭本体の内周面が、後側から前側に向けて拡径する内周面となるから、ハブ部材を霧化頭本体に組付けるときに、拡径内周面は、ハブ部材の脚部を徐々に弾性変形させてハブ嵌合凹溝に容易に嵌合させることができる。また、各孔状塗料通路を通過した塗料は、環状塗料通路を流れて塗料薄膜化面に供給される。
【００３４】
請求項７の発明によると、環状塗料通路は、後側から前側に向けてほぼ等しい径寸法をもった環状塗料通路として形成したことにある。
【００３５】
このように構成したことにより、各孔状塗料通路を通過した塗料は、均径な環状塗料通路を流れて塗料薄膜化面に供給される。
【００３６】
【発明の実施の形態】
以下、本発明の実施の形態による回転霧化頭を用いた回転霧化頭型塗装装置を図１ないし図８に従って詳細に説明する。
【００３７】
１は回転霧化頭型塗装装置のカバーで、該カバー１は円筒状に形成され、その内部には、後述のエアモータ２を収容している。
【００３８】
２はカバー１内に収容されたエアモータで、該エアモータ２は、筒状に形成されたモータケーシング２Ａと、該モータケーシング２Ａ内に収容されたエアタービン２Ｂと、後述する回転軸３を回転可能に軸支する静圧エア軸受２Ｃとによって大略構成されている。そして、エアモータ２は、エアタービン２Ｂに圧縮エアが供給されることにより、回転軸３を回転駆動するものである。
【００３９】
３はエアモータ２の静圧エア軸受２Ｃに回転可能に支持された中空の回転軸で、該回転軸３の先端はエアモータ２の前側に突出し、その先端部には後述の回転霧化頭１１が取付けられている。また、回転軸３の基端側はエアモータ２のエアタービン２Ｂに取付けられている。
【００４０】
４は回転軸３内に挿通して設けられたフィードチューブで、該フィードチューブ４の先端部は、回転軸３から突出して回転霧化頭１１内に延在している。そして、フィードチューブ４は、同軸な二重筒として形成され、中央に位置して塗料と洗浄流体としてのシンナ等が流通する塗料通路４Ａと、該塗料通路４Ａの外周側に位置してシンナ等が流通する環状のシンナ通路４Ｂとによって構成されている。そして、フィードチューブ４は、塗装作業時には、塗料通路４Ａから回転霧化頭１１に向け塗料を供給する。また、塗料の色替等に伴う洗浄作業時には、塗料通路４Ａは後述するハブ部材１４の前面等を洗浄するシンナ等を供給し、シンナ通路４Ｂは霧化頭本体１２の塗料薄膜化面１２Ｃ、放出端縁１２Ｄ等を洗浄するシンナ等を供給する。
【００４１】
５はカバー１の先端部に取付けられたシェーピングエアリングで、該シェーピングエアリング５は、円筒状に形成され、その先端側には回転霧化頭１１から噴霧された塗料の噴霧パターン等を制御するためのエアを噴出するエア噴出口５Ａ，５Ａ，…が周方向に多数個形成されている。
【００４２】
次に、１１は回転軸３の先端部に取付けられた本実施の形態による回転霧化頭で、該回転霧化頭１１は、図２に示す如く、後述する霧化頭本体１２、ハブ嵌合凹溝１３、ハブ部材１４、孔状塗料通路１９、環状塗料通路２０等によって大略構成されている。
【００４３】
１２は回転霧化頭１１の外形をなし、後部側から前部側に向けて拡開するベル形に形成された霧化頭本体で、該霧化頭本体１２は、例えばアルミニウム合金、ステンレス合金、硬質な樹脂材料等を用いて形成されている。ここで、霧化頭本体１２を樹脂材料によって形成する場合には、導電性を有する導電性樹脂材料、または表面に導電性塗料の皮膜処理を施した非導電性の樹脂材料が用いられている。これにより、霧化頭本体１２には、塗装を行なう場合に高電圧を印加することができるから、該霧化頭本体１２は、その表面を流れる塗料を高電圧に直接的に帯電させることができる。
【００４４】
そして、霧化頭本体１２は、その後端側が円筒状の回転軸取付部１２Ａとなり、該回転軸取付部１２Ａの奥部にはエアモータ２の回転軸３に螺着される雌ねじ１２Ａ1が刻設されている。また、霧化頭本体１２には、回転軸取付部１２Ａの奥部を閉塞するように環状隔壁１２Ｂが径方向内向きに突出して形成され、該環状隔壁１２Ｂの内周側には回転軸３の先端側から突出したフィードチューブ４の先端が挿通される。
【００４５】
一方、霧化頭本体１２の前面側は、円皿状に拡開する塗料薄膜化面１２Ｃとなり、霧化頭本体１２の前端（外周端）は塗料薄膜化面１２Ｃに連続した放出端縁１２Ｄとなっている。また、霧化頭本体１２には、奥部側に位置して環状隔壁１２Ｂと後述のハブ部材１４との間に塗料溜り１２Ｅが設けられ、該塗料溜り１２Ｅは、フィードチューブ４から吐出された塗料を一時的に溜め、拡散する空間である。さらに、塗料溜り１２Ｅと塗料薄膜化面１２Ｃとの間に位置する霧化頭本体１２の内周面１２Ｆは、図５に示すように、後側から前側に向けて拡径した拡径内周面として形成されている。また、前側が拡径した拡径内周面１２Ｆの前端部（塗料薄膜化面１２Ｃとの境界部）の内径寸法Ｄ1は、後述するハブ嵌合凹溝１３の最大内径寸法Ｄ2よりも大きく設定されている（Ｄ1＞Ｄ2）。
【００４６】
そして、霧化頭本体１２は、回転霧化頭１１が高速回転している状態で、塗料溜り１２Ｅに塗料が供給されると、この塗料を後述する孔状塗料通路１９から塗料薄膜化面１２Ｃに供給する。これにより、塗料薄膜化面１２Ｃに供給された塗料は、放出端縁１２Ｄから塗料粒子となって噴霧される。
【００４７】
１３は霧化頭本体１２の内周面１２Ｆに設けられたハブ嵌合凹溝で、該ハブ嵌合凹溝１３は、後述するハブ部材１４の脚部１７先端が係合、離脱可能に嵌合するもので、拡径内周面１２Ｆの前，後方向中間位置を全周に亘り断面円弧状に窪ませることによって形成されている。また、ハブ嵌合凹溝１３は、図６に示す如く、内周面１２Ｆとの間の境界部が滑らかな前側円弧面１３Ａ，後側円弧面１３Ｂとなっている。そして、各円弧面１３Ａ，１３Ｂは、塗料溜り１２Ｅから塗料薄膜化面１２Ｃに向け塗料が流れるときに、この塗料が飛散せずに円滑にハブ嵌合凹溝１３を乗り越えることができるようにしている。
【００４８】
ここで、ハブ嵌合凹溝１３の最大内径寸法Ｄ2は、前側円弧面１３Ａの位置での内径寸法Ｄ3よりも大きな寸法で、内周面１２Ｆの前端部の内径寸法Ｄ1よりも小さな寸法に設定されている（Ｄ1＞Ｄ2＞Ｄ3）。また、ハブ嵌合凹溝１３の最大内径寸法Ｄ2は、後述するハブ部材１４の脚部１７の最大外径寸法Ｄ6と同じ寸法か、または僅かに小さな寸法に設定されている（Ｄ2≦Ｄ6）。これにより、ハブ嵌合凹溝１３は、前側円弧面１３Ａを乗り越えて嵌合するハブ部材１４の各脚部１７をがたつかせることなく確実に保持することができる。
【００４９】
１４は塗料溜り１２Ｅの前方を覆うように霧化頭本体１２に着脱可能に取付けられたハブ部材で、該ハブ部材１４は、遠心力の作用によって変形し易く適度な弾性と撓み性をもった材料、例えばポリエーテルスルホン（ＰＥＳ）、ポリフェニレンサルファイド（ＰＰＳ）、ポリエーテルイミド（ＰＥＩ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、ポリオキシメチレン（ＰＯＭ）、ポリアミドイミド（ＰＡＩ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリイミド（ＰＩ）等の樹脂材料を用いてほぼ円板状に形成されている。そして、ハブ部材１４は、図７に示す如く、後述の蓋部１５、脚部１７、切欠溝１８等によって大略構成されている。
【００５０】
１５はハブ部材１４の本体部をなす円板状に形成された蓋部で、該蓋部１５は、その前面１５Ａが平坦面となり、後面側がフィードチューブ４から吐出される塗料を受けると共に前述した塗料溜り１２Ｅを閉塞する塗料受面１５Ｂとなっている。また、蓋部１５の外周面１５Ｃは、前端部の外径寸法Ｄ4が後端部の外径寸法Ｄ5よりも大きな寸法に設定され（Ｄ4＞Ｄ5）、これにより、後側から前側に向け漸次径寸法が大きくなる拡径外周面として形成されている。また、蓋部１５の前端部の外径寸法Ｄ4は、霧化頭本体１２の拡径内周面１２Ｆ前端部の内径寸法Ｄ1よりも小さく設定されている（Ｄ1＞Ｄ4）。さらに、蓋部１５の後端部の外径寸法Ｄ5はハブ嵌合凹溝１３の前側円弧面１３Ａの位置（即ち、拡径内周面１２Ｆの後端位置）での内径寸法Ｄ3よりも小さく設定されている（Ｄ3＞Ｄ5）。
【００５１】
一方、塗料受面１５Ｂの中心部には、フィードチューブ４から吐出された塗料の受渡しを円滑にするために後側に突出した円錐状突起１５Ｄが形成されている。ここで、蓋部１５の外周面１５Ｃは、霧化頭本体１２に取付けられた状態で、内周面１２Ｆとの間に一定の隙間寸法を有し、後述する環状塗料通路２０を形成する。
【００５２】
１６，１６，…は蓋部１５の軸中心側に設けられた４個のシンナ流出孔で、該各シンナ流出孔１６は、塗料受面１５Ｂ（円錐状突起１５Ｄ）から前面１５Ａに亘って穿設されている。そして、シンナ流出孔１６は、前面１５Ａに付着した塗料を洗浄するときに、シンナを塗料受面１５Ｂから前面１５Ａ側に供給する通路をなしている。
【００５３】
１７，１７，…は蓋部１５の後面外周側に一体的に形成された複数本の脚部（実施例の場合１４本）で、該各脚部１７は、図８に示すように、１本１本が独立して形成され、かつ周方向に等間隔で、全周に亘って配置されている。また、脚部１７は、蓋部１５の後面外周側から先端部１７Ａの方向（軸方向の後側）に離間するに従って径方向外側に向けて拡径する拡径脚部として形成され、その先端部１７Ａ位置での最大外径寸法Ｄ6は、蓋部１５の後端部の外径寸法Ｄ5よりも大きく設定されている（Ｄ6＞Ｄ5）。また、脚部１７の先端部１７Ａは、自由端となってハブ嵌合凹溝１３にほぼ合致するような球面形状をなしている。
【００５４】
また、脚部１７の先端部１７Ａの最大外径寸法Ｄ6は、蓋部１５の前端部の外径寸法Ｄ4と同じ寸法か、または小さな寸法に形成されている（Ｄ6≦Ｄ4）。さらに、各脚部１７（先端部１７Ａ位置）の最大外径寸法Ｄ6は、ハブ嵌合凹溝１３の最大内径寸法Ｄ2と同じ寸法か、または僅かに大きな寸法に設定されている（Ｄ6≧Ｄ2）。
【００５５】
そして、各脚部１７は、それぞれが独立していることにより、比較的容易に弾性変形することができるから、ハブ嵌合凹溝１３に対する着脱作業を容易に行うことができる。しかも、各脚部１７の最大外径寸法Ｄ6は、ハブ嵌合凹溝１３の最大内径寸法Ｄ2と同じ寸法か、または僅かに大きな寸法に設定しているから、該各脚部１７はハブ嵌合凹溝１３に確実に保持されることになる。
【００５６】
以上の点から霧化頭本体１２の内周面１２Ｆの前端部の内径寸法Ｄ1、ハブ嵌合凹溝１３の最大内径寸法Ｄ2、ハブ嵌合凹溝１３の前側円弧面１３Ａの位置での内径寸法Ｄ3と、ハブ部材１４の蓋部１５の前端部の外径寸法Ｄ4、蓋部１５の後端部の外径寸法Ｄ5、脚部１７の先端部１７Ａ位置での最大外径寸法Ｄ6とは、下記数１の関係にある。
【００５７】
【数１】
Ｄ1＞Ｄ2＞Ｄ3
Ｄ4≧Ｄ6＞Ｄ5
Ｄ6≧Ｄ2
Ｄ1＞Ｄ4
Ｄ3＞Ｄ5
【００５８】
１８，１８，…は蓋部１５の後面外周側に各脚部１７と交互に形成された複数個（実施例では１４個）の切欠溝で、該各切欠溝１８は、隣合う各脚部１７間に位置してほぼＵ字形状に形成され、かつ周方向に等間隔で全周に亘って配置されている。そして、切欠溝１８は、ハブ部材１４の脚部１７を霧化頭本体１２のハブ嵌合凹溝１３に嵌合したときに、該ハブ嵌合凹溝１３との間に後述の孔状塗料通路１９を形成するものである。
【００５９】
１９，１９，…は霧化頭本体１２内にハブ部材１４を取付けたときに、該霧化頭本体１２のハブ嵌合凹溝１３の内周面とハブ部材１４の各切欠溝１８との間に形成される複数個の孔状塗料通路で、該各孔状塗料通路１９は、図３に示すように周方向に等間隔で、全周に亘り、各脚部１７と交互に切欠溝１８と対応した数だけ独立して多数個列設されている。そして、各孔状塗料通路１９は、回転霧化頭１１を高速回転し、フィードチューブ４から塗料溜り１２Ｅに塗料を供給したときに、この塗料を後述の環状塗料通路２０に向け均一に流通するものである。
【００６０】
また、２０は霧化頭本体１２内にハブ部材１４を取付けたときに、該霧化頭本体１２の拡径内周面１２Ｆとハブ部材１４の蓋部１５の外周面１５Ｃとの間に形成される環状塗料通路で、該環状塗料通路２０は、図２、図４に示す如く、全周に亘って円環状をなし、内周面１２Ｆ、外周面１５Ｃにより後側から前側に向けて漸次径寸法が大きくなるように拡径している。これにより、拡径した環状塗料通路２０は、霧化頭本体１２の拡径内周面１２Ｆと蓋部１５の外周面１５Ｃとの間で、塗料を均一に流通することができ、また各面１５Ｃ、１２Ｆに接触するようにシンナを流通することができる。
【００６１】
ここで、環状塗料通路２０の幅寸法ａ（図２中に図示）は、その前端側で下記数２の関係にある。
【００６２】
【数２】
ａ≒（Ｄ1−Ｄ4）／２
【００６３】
本実施の形態による回転霧化頭１１は上述の如き構成を有するもので、次に、回転霧化頭１１の組立作業、回転霧化頭１１による塗装動作および固着した塗料中の顔料等の除去（分解）作業について説明する。
【００６４】
最初に、回転霧化頭１１の組立作業、即ち霧化頭本体１２にハブ部材１４を組付ける作業について説明する。
【００６５】
まず、霧化頭本体１２の塗料溜り１２Ｅを覆うようにハブ部材１４をあてがい、該ハブ部材１４を塗料溜り１２Ｅ側に押込むように押圧する。このときに、霧化頭本体１２の拡径内周面１２Ｆは、その前端部の内径寸法Ｄ1が各脚部１７の最大外径寸法Ｄ6よりも大きく設定されているから、ハブ部材１４を霧化頭本体１２の中央に位置決めすることができる。しかも、拡径内周面１２Ｆは、前側から後側に向け漸次径寸法が小さくなっているから、ハブ部材１４の各脚部１７は、徐々に弾性変形することができ、前側円弧面１３Ａを乗り越えることによってハブ嵌合凹溝１３に容易に嵌合することができる。さらに、脚部１７は、１本、１本が独立しているから、比較的容易に撓むことができ、これによってもハブ嵌合凹溝１３に容易に嵌合することができる。
【００６６】
そして、ハブ嵌合凹溝１３に嵌合したハブ部材１４の各脚部１７は、その最大外径寸法Ｄ6がハブ嵌合凹溝１３の最大内径寸法Ｄ2と同じ寸法か、または僅かに大きな寸法に設定されているから、各脚部１７は、ハブ嵌合凹溝１３に合致し、確実に保持される。
【００６７】
次に、このように組立てられた回転霧化頭１１を用いて被塗物に塗料を噴霧する塗装作業について説明する。
【００６８】
まず、エアモータ２によって回転軸３と共に回転霧化頭１１を高速、例えば３０００〜１０００００ｒｐｍで回転駆動する。このときには、回転霧化頭１１の霧化頭本体１２、ハブ部材１４に遠心力が作用するが、該ハブ部材１４の各脚部１７は、それぞれ独立して形成されており、弾性変形し易くなっているから、霧化頭本体１２よりもハブ部材１４の各脚部１７の方が径方向に大きく広がる。これにより、該各脚部１７は、ハブ嵌合凹溝１３に強く押付けられるから、ハブ嵌合凹溝１３によるハブ部材１４の保持状態をより一層高めることができる。
【００６９】
そして、フィードチューブ４からハブ部材１４の塗料受面１５Ｂに塗料を供給すると、塗料受面１５Ｂに供給された塗料は、遠心力により塗料溜り１２Ｅから各孔状塗料通路１９、環状塗料通路２０を通って霧化頭本体１２の塗料薄膜化面１２Ｃに流出する。このとき、各孔状塗料通路１９は、蓋部１５の外周側に全周に亘り等間隔で独立して形成されているから、塗料溜り１２Ｅに供給された塗料は、各孔状塗料通路１９から均一に流出する。しかも、環状塗料通路２０は、ほぼ一定の幅寸法ａをもって形成しているから、塗料を全周に亘って均一に流通することができる。これにより、塗料薄膜化面１２Ｃに供給された塗料は、放出端縁１２Ｄから塗料粒子となって噴霧され、被塗物に塗着する。
【００７０】
この塗装時に、回転霧化頭１１に高電圧発生器（図示せず）から供給される高電圧を印加することにより、霧化頭本体１２等の表面を流れる塗料を高電圧に直接的に帯電させることができるから、この帯電塗料を被塗物に向け飛行させて塗着効率を高めることができる。
【００７１】
次に、前色の塗装が終了し、次色の塗料に色替を行う場合の色替動作について説明する。
【００７２】
まず、塗料の色替を行う場合には、各部に付着している前色の塗料を洗浄する、所謂自動洗浄を行う。この自動洗浄作業では、回転霧化頭１１を回転させた状態で、フィードチューブ４の塗料通路４Ａにシンナを供給して前色の塗料を排出した後に、シンナ通路４Ｂから回転霧化頭１１に向け洗浄流体となるシンナ等を供給する。このときに、環状塗料通路２０は、ほぼ一定の幅寸法ａをもって形成し、かつ前側に向け漸次径寸法が大きくなるように拡径して形成しているから、ハブ部材１４の外周面１５Ｃにもシンナを供給することができる。
【００７３】
これにより、環状塗料通路２０を流通するシンナは、霧化頭本体１２の拡径内周面１２Ｆ、ハブ部材１４の外周面１５Ｃに付着した前色塗料を効率よく洗浄することができる。また、孔状塗料通路１９から流出したシンナは、霧化頭本体１２の塗料薄膜化面１２Ｃ、放出端縁１２Ｄに付着した塗料を洗浄し、シンナ流出孔１６から流出したシンナは、ハブ部材１４の前面１５Ａを洗浄することができる。
【００７４】
一方、ハブ部材１４の切欠溝１８、ハブ嵌合凹溝１３と各脚部１７との間の隙間等に付着した塗料は、前述した自動洗浄作業では除去することができない。このため、ハブ部材１４の切欠溝１８等には、付着した塗料中に含まれる顔料成分等が徐々に堆積して固着物となる。このため、この固着物は、回転霧化頭１１を分解し、この分解状態で除去するようになっている。そこで、回転霧化頭の分解作業、固着物の除去作業について説明する。
【００７５】
まず、霧化頭本体１２からハブ部材１４を取外す場合には、これに先立って回転軸３から回転霧化頭１１を取外す。次に、霧化頭本体１２の回転軸取付部１２Ａ内に棒状の分解用治具（図示せず）を挿入し、該冶具によってハブ部材１４を後側から押圧する。このときに、例えば脚部１７とハブ嵌合凹溝１３との間に塗料中の顔料等が固着物となって固着している場合でも、各脚部１７は、独立して形成され、弾性変形し易くなっているから、ハブ部材１４は、脚部１７を弾性変形させながらハブ嵌合凹溝１３から容易に取外すことができる。
【００７６】
このようにして霧化頭本体１２からハブ部材１４を取外した状態では、各孔状塗料通路１９は、霧化頭本体１２側のハブ嵌合凹溝１３とハブ部材１４側の切欠溝１８とに分割されるから、ブラシ等を用いてハブ嵌合凹溝１３、切欠溝１８を擦ることにより、固着物を容易に除去することができる。その他にも、洗浄が困難な霧化頭本体１２の塗料溜り１２Ｅ、内周面１２Ｆ、ハブ部材１４の外周面１５Ｃ、脚部１７等の塗料接液部に堆積し固着した固着物を、ハブ嵌合凹溝１３、切欠溝１８と同様に容易に除去することができる。
【００７７】
かくして、本実施の形態によれば、霧化頭本体１２は金属材料または硬質な樹脂材料を用いて形成し、ハブ部材１４は適度な弾性と撓み性を有する樹脂材料を用いて形成している。また、霧化頭本体１２の拡径内周面１２Ｆにはハブ嵌合凹溝１３を設け、ハブ部材１４には該ハブ嵌合凹溝１３に係合、離脱可能に嵌合する脚部１７を設けている。これにより、霧化頭本体１２にハブ部材１４を取付けるときには、霧化頭本体１２の内周面１２Ｆにハブ部材１４をあてがい、該ハブ部材１４を押込むことにより、脚部１７を弾性変形させながらハブ嵌合凹溝１３内に嵌合することができる。
【００７８】
この結果、回転霧化頭１１を高速回転させたときには、適度な弾性と撓み性を有する樹脂材料を用いて形成されたハブ部材１４は、その脚部１７をハブ嵌合凹溝１３に強く押付けることができるから、ハブ嵌合凹溝１３内での脚部１７の保持力を高めることができ、ハブ部材１４の脱落事故等を未然に防止して、回転霧化頭１１に対する信頼性を向上することができる。また、ハブ部材１４の回転バランスを長期に亘って安定させることができる。
【００７９】
一方、自動洗浄作業では除去することが困難な、ハブ部材１４の切欠溝１８、ハブ嵌合凹溝１３と各脚部１７との間の隙間等に堆積し固着した顔料等の固着物を除去する場合には、分解用治具を用いて霧化頭本体１２の回転軸取付部１２Ａ側からハブ部材１４を押圧することにより、該ハブ部材１４を霧化頭本体１２から容易に取外すことができる。この状態では、孔状塗料通路１９は、霧化頭本体１２側のハブ嵌合凹溝１３とハブ部材１４側の切欠溝１８とに分離することができるから、ブラシ等を用いてハブ嵌合凹溝１３、切欠溝１８を擦ることにより、各部に固着した固着物を容易に除去することができ、作業性を向上することができる。
【００８０】
また、環状塗料通路２０は、ほぼ一定の幅寸法ａをもって形成しているから、塗装を行うときには、塗料を全周に亘って均一に流通することができ、塗装品質を高めることができる。一方、塗料の洗浄を行うときには、霧化頭本体１２の内周面１２Ｆ、ハブ部材１４の外周面１５Ｃに付着した塗料をシンナによって効率よく洗浄することができ、洗浄効率を向上することができる。
【００８１】
また、ハブ部材１４の各脚部１７は、それぞれが独立して形成されているから、ハブ嵌合凹溝１３に嵌合、離脱するときに容易に弾性変形することができる。これにより、従来技術で述べたように、例えば脚部１７とハブ嵌合凹溝１３との間の孔状塗料通路１９に顔料等の固着物が固着している場合でも、ハブ部材１４は、指先の力だけで取外したり、取付けたりすることができ、着脱作業を容易に行うことができる。
【００８２】
さらに、ハブ嵌合凹溝１３は、拡径内周面１２Ｆとの間の境界部を滑らかな円弧面１３Ａ，１３Ｂとしているから、塗料溜り１２Ｅから塗料薄膜化面１２Ｃに向けて流れる塗料は、境界部で飛散することなく、ハブ嵌合凹溝１３を円滑に乗り越えることができる。これにより、円弧面１３Ａ，１３Ｂは、霧化頭本体１２内での塗料の流れをスムーズにして塗装品質を向上することができる。
【００８３】
また、後側から前側に向けて径寸法が大きくなる拡径した環状塗料通路２０によって、霧化頭本体１２の内周面１２Ｆも、後側から前側に向けて拡径した拡径内周面として形成されているから、ハブ部材１４を霧化頭本体１２に取付けるときに、該ハブ部材１４は、霧化頭本体１２の中央に位置決めすることができ、取付作業を容易かつ正確に行うことができる。
【００８４】
一方、ハブ部材１４の各脚部１７は、独立形状によって弾性変形し易くなっているから、ハブ部材１４を霧化頭本体１２と同様の金属材料、硬質な樹脂材料等によって形成した場合でも、各脚部１７は、容易に撓むことができ、ハブ嵌合凹溝１３内で十分な保持力を得ることができる。
【００８５】
なお、実施の形態では、霧化頭本体１２とハブ部材１４との間には、それぞれ後側から前側に向けて漸次径寸法が大きくなった霧化頭本体１２の拡径内周面１２Ｆと蓋部１５の外周面１５Ｃとによって拡径した環状塗料通路２０を形成した場合を例に挙げて説明した。
【００８６】
しかし、本発明はこれに限るものではなく、例えば図９に示す変形例のような回転霧化頭３１を用いてもよい。この場合、回転霧化頭３１は、回転軸取付部３２Ａ、環状隔壁３２Ｂ、塗料薄膜化面３２Ｃ、放出端縁３２Ｄ、塗料溜り３２Ｅ、内周面３２Ｆからなり、内周面３２Ｆにハブ嵌合凹溝３３が設けられた霧化頭本体３２と、蓋部３５、シンナ流出孔３６、脚部３７、切欠溝３８からなるハブ部材３４と、ハブ嵌合凹溝３３と切欠溝３８との間の孔状塗料通路３９とによって大略構成する。そして、ほぼ等しい径寸法をもった均径内周面３２Ｆと蓋部３５の外周面３５Ｃとの間には、後側から前側に向けてほぼ等しい径寸法をもった均径な環状塗料通路４０を形成する構成としてもよい。
【００８７】
従って、この変形例によれば、均径な環状塗料通路４０は、孔状塗料通路３９を通過した塗料を、塗料薄膜化面３２Ｃに供給することができる。また、シンナ等を供給したときには、環状塗料通路４０に付着した塗料を洗浄することができる。
【００８８】
また、実施の形態では、ハブ部材１４には１４本の各脚部１７を設けた場合を例に挙げて図示したが、本発明はこれに限らず、脚部１７は、ハブ部材１４を霧化頭本体１２に支持することができる本数、即ち、周方向に３本以上設けられていればよい。そして、脚部１７の本数が少ない場合には、孔状塗料通路は周方向に延びるスリット状の長孔となる。
【００８９】
一方、実施の形態では、回転霧化頭１１の霧化頭本体１２を金属材料または導電性の樹脂材料によって形成し、該霧化頭本体１２等を介して直接的に塗料を高電圧に帯電させる直接帯電式の回転霧化頭型塗装装置を例に挙げて説明したが、本発明はこれに限らず、例えばカバー１の外周側には外部電極を設け、この外部電極が回転霧化頭１１から噴霧された塗料を間接的に高電圧に帯電させる間接帯電式の回転霧化頭型塗装装置に適用してもよい。
【００９０】
さらに、実施の形態では、霧化頭本体１２をベル形状に形成した場合を例示したが、霧化頭本体は回転軸取付部から放出端縁に向けて徐々に大径となった筒形状に形成してもよい。
【００９１】
【発明の効果】
以上詳述した通り、請求項１の発明によれば、霧化頭本体には、塗料溜りと塗料薄膜化面との間の内周面に全周に亘って凹溝状に形成されたハブ嵌合凹溝を設け、ハブ部材は、霧化頭本体の内周面のうち該ハブ嵌合凹溝の前端と塗料薄膜化面との間に位置する部位の内径に比較して小径な円板状体からなる蓋部と、該蓋部から軸方向の後側に延びて設けられ先端部が弾性変形しながら前記ハブ嵌合凹溝に係合、離脱可能に嵌合する複数本の脚部と、隣合う各脚部間に位置して設けられた複数個の切欠溝とにより構成し、ハブ部材の各脚部を前記ハブ嵌合凹溝に嵌合したときには、前記ハブ嵌合凹溝と各切欠溝との間に複数の孔状塗料通路を形成すると共に、霧化頭本体の内周面と蓋部の外周面との間に環状塗料通路を形成する構成としている。
【００９２】
従って、霧化頭本体の塗料溜りを覆うようにハブ部材をあてがい、該ハブ部材を霧化頭本体内に押込むことにより、該ハブ部材の各脚部を弾性変形させる。このときに各脚部は、それぞれが独立しているから霧化頭本体の内周面で径方向の内側に比較的容易に弾性変形することができ、ハブ嵌合凹溝で拡径して当該ハブ嵌合凹溝に嵌合することができる。これにより、各脚部は、その弾性力によってハブ部材をハブ嵌合凹溝に係合し、抜止め状態に保持することができる。そして、回転霧化頭を高速回転させたときには、ハブ部材の各脚部は、遠心力によって拡径しようとするから、該各脚部は、ハブ部材を霧化頭本体内に強固に支持することができるから、ハブ部材の脱落事故等を未然に防止して、回転霧化頭に対する信頼性を向上することができる。
【００９３】
また、ハブ部材は、ハブ嵌合凹溝に嵌合した状態で、各切欠溝とハブ嵌合凹溝との間に孔状塗料通路を形成すると共に、蓋部の外周面と霧化頭本体の内周面との間に環状塗料通路を形成する構成としている。これにより、塗装を行う場合には、塗料溜りに塗料を供給することにより、この塗料は該塗料溜りから各孔状塗料通路と環状塗料通路を通して塗料薄膜化面に均一に流出させることができ、放出端縁から均一な塗料粒子として飛行させ、被塗物の塗装品質を向上することができる。
【００９４】
しかも、各孔状塗料通路、環状塗料通路等に堆積して固着した塗料中の顔料等の固着物を除去する場合には、霧化頭本体の回転軸取付部側からハブ部材の後面を前側に押圧する。これにより、ハブ嵌合凹溝と脚部との隙間に固着物が固着している場合でも、ハブ部材を霧化頭本体内に押込んだときと同様に、各脚部を容易に弾性変形させて、該ハブ部材をハブ嵌合凹溝から取外すことができる。そして、霧化頭本体からハブ部材を取外した状態では、孔状塗料通路は、ハブ部材の切欠溝と霧化頭本体のハブ嵌合凹溝とに分割されるから、ブラシ等を用いて切欠溝、ハブ嵌合凹溝に固着した顔料等の固着物を容易に除去することができ、また、霧化頭本体の内周面、ハブ部材の塗料受面等の塗料接液部に堆積し固着した固着物も容易に除去することができ、作業性を向上することができる。
【００９５】
請求項２の発明によれば、各脚部と切欠溝は蓋部の外周側に交互に形成し、各孔状塗料通路は各切欠溝とハブ嵌合凹溝との間に独立して形成する構成としている。これにより、塗料溜りに供給された塗料は各孔状塗料通路から均一に流出し、環状塗料通路に流出するから、均一な塗料粒子として被塗物に塗着することができる。
【００９６】
請求項３の発明によれば、環状塗料通路は、霧化頭本体の内周面とハブ部材の蓋部外周面との間に全周に亘って円環状に形成しているので、環状塗料通路は、各孔状塗料通路を通過した塗料を塗料薄膜化面に供給することができる。
【００９７】
請求項４の発明によれば、各脚部は、蓋部の位置から先端部の方向に離間するに従って径方向外側に向けて拡径する拡径脚部として形成しているので、ハブ部材を霧化頭本体内に押込んだときには、各脚部は、最も径方向の外側に位置する先端部をハブ嵌合凹溝に確実に嵌合することができる。
【００９８】
請求項５の発明によれば、霧化頭本体のハブ嵌合凹溝と内周面との間の境界部は、滑らかな円弧面として形成しているので、塗料等が塗料溜りから塗料薄膜化面に向けてハブ嵌合凹溝を乗り越えるように流れるときに、円弧面はこの塗料等を飛散させることなく、円滑に流通することができ、塗料の供給を安定化させて、塗装品質を向上することができる。
【００９９】
請求項６の発明によれば、環状塗料通路は、後側から前側に向けて漸次径寸法が大きくなる環状塗料通路として形成しているので、霧化頭本体の内周面は、後側から前側に向けて拡径する内周面となるから、該拡径内周面は、ハブ部材の脚部を徐々に弾性変形させてハブ嵌合凹溝に容易に嵌合させることができ、組立作業性を向上することができる。また、環状塗料通路は、各孔状塗料通路を通過した塗料を塗料薄膜化面に供給することができる。
【０１００】
請求項７の発明によれば、環状塗料通路は、後側から前側に向けてほぼ等しい径寸法をもった環状塗料通路として形成しているので、環状塗料通路は、各孔状塗料通路を通過した塗料を塗料薄膜化面に供給することができ、洗浄流体を供給したときには、環状塗料通路に付着した塗料を洗浄することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態による回転霧化頭を備えた回転霧化頭型塗装装置を示す断面図である。
【図２】図１中の回転霧化頭を拡大して示す拡大断面図である。
【図３】図２中の矢示III−III方向からみた要部拡大断面図である。
【図４】図２中の矢示IV−IV方向からみた要部拡大断面図である。
【図５】霧化頭本体とハブ部材とを分解して示す分解断面図である。
【図６】ハブ嵌合凹溝の近傍を拡大して示す要部拡大断面図である。
【図７】ハブ部材を単体で拡大して示す正面図である。
【図８】ハブ部材を図７中の矢示VIII−VIII方向からみた右側面図である。
【図９】本発明の変形例による回転霧化頭を図２と同様位置からみた拡大断面図である。
【符号の説明】
１１，３１回転霧化頭
１２，３２霧化頭本体
１２Ａ，３２Ａ回転軸取付部
１２Ｃ，３２Ｃ塗料薄膜化面
１２Ｄ，３２Ｄ放出端縁
１２Ｅ，３２Ｅ塗料溜り
１２Ｆ，３２Ｆ内周面
１３，３３ハブ嵌合凹溝
１３Ａ，１３Ｂ円弧面
１４，３４ハブ部材
１５，３５蓋部
１５Ｃ，３５Ｃ外周面
１７，３７脚部
１７Ａ先端部
１８，３８切欠溝
１９，３９孔状塗料通路
２０，４０環状塗料通路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary atomizing head suitable for use in, for example, a coating machine that coats an object to be coated such as a vehicle body.
[0002]
[Prior art]
In general, when painting on an object to be coated such as a car body of an automobile, a rotary atomizing head type coating apparatus that is advantageous in terms of, for example, the coating efficiency and the coating finish is frequently used. And the rotary atomization head used for this rotary atomization head type coating device is roughly comprised by the atomization head main body and the hub member.
[0003]
For example, in a rotary atomizing head type coating apparatus described in Japanese Patent Application Laid-Open No. 9-234393, the atomizing head body of the rotary atomizing head serves as a rotary shaft attaching portion for attaching the rear end side to the rotary shaft of the air motor. , It is formed in a cylindrical shape or a bell shape from the rotating shaft mounting portion toward the front side. In addition, a paint thinning surface for thinning the paint toward the discharge edge is formed on the front side of the atomizing head body, and a paint reservoir is provided on the back side of the paint thinning surface. . Further, the atomizing head main body is provided with a stepped hub fitting step portion located between the paint thinning surface and the paint reservoir.
[0004]
On the other hand, the hub member of the rotary atomizing head is fitted and attached to the hub fitting step so as to cover the front of the paint reservoir, and on the outer peripheral side of the hub member, the paint supplied to the paint reservoir is provided. A large number of paint outflow holes for allowing the paint to flow out into the coating film thinning surface of the atomizing head main body are formed.
[0005]
Also, an O-ring is fitted on either the inner peripheral surface of the hub fitting step formed on the atomizing head main body or the outer peripheral surface of the hub member, and the hub is fitted by the elastic force of the O-ring. A hub member is attached to the stepped portion so as to be detachably held.
[0006]
Here, when the rotary atomizing head is washed by normal color change or the like, so-called automatic cleaning is performed in which the rotary atomizing head is attached to the coating apparatus while the rotary atomizing head is attached. That is, the automatic cleaning means that a cleaning fluid such as thinner is supplied from a feed tube to a paint reservoir of the atomizing head main body while the rotary atomizing head is rotated at a high speed. The paint adhering to the paint wetted parts such as the front face, the rear face of the hub member, the paint outflow hole, and the paint thinning surface is washed away. However, even if this automatic cleaning is performed, pigment components and the like contained in the coating material adhere to and accumulate on these coating liquid contact portions little by little during painting. For this reason, when a pigment or the like adheres to the paint wetted part, the rotary atomizing head is removed from the rotary shaft, and a fixed object such as a pigment adhered to the paint wetted part manually using a brush or the like. Has been removed.
[0007]
[Problems to be solved by the invention]
By the way, according to the rotary atomizing head described in Japanese Patent Laid-Open No. 9-234393 described above, the hub member is configured to be attached to the hub fitting step portion by using the elastic force of the O-ring and detachably held. In this case, the O-ring has enough elasticity to be easily deformed when pressed. For this reason, when the rotary atomizing head is rotated at a high speed of, for example, 40000 rpm or more, the inner diameter of the O-ring increases due to the centrifugal force acting on the O-ring.
[0008]
On the other hand, the atomizing head main body and the hub member are generally formed using an aluminum alloy, a stainless alloy, a hard resin material, or the like. Therefore, even when the rotary atomizing head is rotated at a high speed and a centrifugal force is applied, the atomizing head main body and the hub member are deformed very small compared to the deformation amount of the O-ring.
[0009]
For these reasons, when the rotary atomizing head is rotated at a high speed, only the O-ring expands in diameter by centrifugal force, so that the O-ring cannot hold the hub member. As a result, there is a problem that the holding force of the hub member by the O-ring is reduced, and there is a possibility that the hub member may rattle in the hub fitting step portion.
[0010]
Further, the O-ring deteriorates and the elastic force decreases when the atomizing head main body and the hub member are repeatedly attached and detached. When the rotary atomizing head is rotated at a high speed in this state, the O-ring cannot reliably support the rotating atomizing head, and the rotational balance of the rotary atomizing head becomes unstable. Furthermore, if the attaching / detaching operation of the atomizing head main body and the hub member is repeated, the O-ring rubs against and damages the mating member, so that there is a problem that frequent replacement is required.
[0011]
In addition, even if the rotary atomizing head is automatically washed by color change or the like, the paint between the hub fitting step of the atomizing head main body and the outer peripheral surface of the hub member is not removed from the paint outflow hole during painting. The pigment in the paint deposits and sticks. Therefore, in order to remove the fixed matter such as pigment stuck to the gap, it is necessary to push the rear part of the hub member and remove the hub member from the atomizing head main body. In such a case, there is a problem that the fixed member such as the pigment is hardened in the gap and acts like a wedge, so that the hub member cannot be easily removed. Moreover, if a strong force is applied to the rear part of the hub member using a hammer or the like to forcefully remove the hub member from the atomizing head body, the hub fitting step of the atomizing head body and the outer peripheral surface of the hub member There is a problem that the mating surface is damaged.
[0012]
On the other hand, the hub member is provided with a large number of paint outflow holes. However, these paint outflow holes are required to uniformly flow out of the paint from the paint reservoir to the surface where the paint film is thinned. Therefore, the diameter of the paint outflow holes is small and a large number are arranged in the circumferential direction. Therefore, when the paint passes through the paint outflow hole, pigment components and the like in the paint adhere to and accumulate on the inner surface of the paint outflow hole, and gradually reduce the diameter of the paint outflow hole.
[0013]
As a result, the diameter size of each paint outflow hole varies depending on the accumulation of paint, so the flow rate of the paint flowing out from each paint outflow hole to the paint thinning surface is not stable. Cannot be uniformly thinned. For this reason, there is a problem in that the coating particles discharged from the discharge edge become uneven, resulting in a decrease in coating quality.
[0014]
In addition, when the diameter of the paint outflow hole is reduced, the paint does not flow out and fills the paint reservoir, so that the paint overflowing from the paint reservoir flows into the gap such as the rotating shaft and adversely affects the air motor. There is.
[0015]
Therefore, in the prior art, a thin rod-like (needle-like) tool made of a metal material is used to pass one of these rods through a number of paint outflow holes, and the paint deposited and fixed in each paint outflow hole is removed. is doing. For this reason, there is a problem that a great amount of labor is required to remove the adhered paint, resulting in a decrease in workability.
[0016]
The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a rotary atomizing head in which the atomizing head main body and the hub member can be easily assembled and disassembled. There is.
[0017]
Another object of the present invention is to provide a rotary atomizing head capable of reliably holding the hub member in the hub fitting concave groove even at high speed rotation.
[0018]
Furthermore, another object of the present invention is to provide a rotary atomizing head which can easily remove fixed matters such as pigments in the paint adhering to the paint passage.
[0019]
[Means for Solving the Problems]
The rotary atomizing head according to the present invention is formed in a cylindrical shape or a bell shape, and the rear end side serves as a rotary shaft mounting portion for mounting on the rotary shaft, In front of the inner surface An atomizing head body whose side is a paint thinning surface for thinning the paint toward the discharge edge and whose back side is a paint reservoir, and the atomizing head body so as to cover the front of the paint reservoir Detachable And an attached hub member.
[0020]
In order to solve the above-mentioned problem, the feature of the configuration adopted by the invention of claim 1 of the present invention is that the atomizing head main body is entirely disposed on the inner peripheral surface between the paint reservoir and the paint thinning surface. A hub fitting groove formed in a groove shape over the circumference is provided, and the hub member is an inner peripheral surface of the atomizing head main body. Compared to the inner diameter of the part located between the front end of the hub fitting concave groove and the paint thin film surface A plurality of lids made of a small-diameter disk-like body, and a plurality of fittings that are provided extending from the lid to the rear side in the axial direction and that engage and detachably engage with the hub fitting concave groove while elastically deforming the tip. When the leg portion of the hub member is fitted in the hub fitting concave groove, the hub portion is formed by a leg portion of the book and a plurality of cutout grooves provided between the adjacent leg portions. A plurality of hole paint passages are formed between the fitting concave groove and each notch groove, and an annular paint passage is formed between the inner peripheral surface of the atomizing head main body and the outer peripheral surface of the lid portion. There is.
[0021]
With this configuration, when the hub member is applied so as to cover the paint reservoir of the atomizing head main body and the hub member is pushed into the atomizing head main body, each leg portion of the hub member is independent of each other. Therefore, it is elastically deformed relatively easily inward in the radial direction on the inner peripheral surface of the atomizing head main body, and is expanded in diameter by the hub fitting groove to be fitted into the hub fitting groove. As a result, the hub member is engaged with the hub fitting concave groove by the elastic force of each leg portion and is held in the retaining state. When the rotary atomizing head is rotated at a high speed, each leg portion of the hub member attempts to expand its diameter by centrifugal force, so that it is strongly pressed against the hub fitting concave groove to maintain the holding state of the hub member.
[0022]
In addition, the hub member forms a hole-shaped paint passage between each notch groove and the hub fitting concave groove while being fitted in the hub fitting concave groove. ,fog Inner peripheral surface of the chemical head The part located between the front end of the hub fitting groove and the paint thin film surface When The outer peripheral surface of the lid and Since an annular paint passage is formed between the paint reservoirs, when coating is performed, the paint is supplied to the paint reservoir so that the paint passes through the hole paint passages and the annular paint passage from the paint reservoir. Then flows out as paint particles from the discharge edge and is applied to the object.
[0023]
On the other hand, when removing fixed matters such as pigments in the paint deposited and fixed in each hole paint passage, annular paint passage, etc., the rear surface of the hub member is moved forward from the rotary shaft mounting portion side of the atomizing head main body. Press on. As a result, even when a fixed object is stuck in the gap between the hub fitting concave groove and the leg portion, each leg portion is relatively easy as when the hub member is pushed into the atomizing head main body. Since it is elastically deformed, the hub member can be removed from the hub fitting groove. When the hub member is removed from the atomizing head main body, the hole-shaped paint passage is divided into a notch groove in the hub member and a hub fitting concave groove in the atomizing head main body. Fixed matters such as pigments fixed to the groove and the hub fitting concave groove can be easily removed. In addition, it is possible to easily remove the fixed matter that has accumulated and adhered to the paint wetted parts such as the inner peripheral surface of the atomizing head main body and the paint receiving surface of the hub member.
[0024]
According to the invention of claim 2, the leg portions and the notch grooves are alternately formed on the outer peripheral side of the lid portion, and the hole-shaped paint passages are independently formed between the notch grooves and the hub fitting recess grooves. It is in the configuration.
[0025]
With this configuration, the paint supplied to the paint reservoir uniformly flows out from each hole-shaped paint passage and flows out into the annular paint passage.
[0026]
According to the invention of claim 3, the annular paint passage is formed in an annular shape over the entire circumference between the inner peripheral surface of the atomizing head main body and the outer peripheral surface of the lid portion of the hub member.
[0027]
With this configuration, the paint that has passed through each hole-shaped paint passage flows through the annular paint passage and is supplied to the paint thinning surface.
[0028]
According to the invention of claim 4, each leg portion is formed as a diameter-expanded leg portion that increases in diameter toward the radially outer side as the distance from the position of the lid portion in the direction of the distal end portion.
[0029]
With this configuration, each leg has its distal end positioned on the outermost side in the radial direction. Therefore, when the hub member is pushed into the atomizing head body, the distal end of each leg is It can be securely fitted into the hub fitting groove.
[0030]
According to invention of Claim 5, the boundary part between the hub fitting recessed groove of an atomization head main body and an internal peripheral surface exists in having formed as a smooth circular arc surface.
[0031]
With this configuration, when the paint flows from the paint reservoir toward the paint thinning surface over the hub fitting groove, the arc surface smoothly circulates without scattering the paint. be able to.
[0032]
According to the invention of claim 6, the annular paint passage is formed as an annular paint passage having a gradually increasing diameter from the rear side toward the front side.
[0033]
By configuring in this way, the inner peripheral surface of the atomizing head main body becomes an inner peripheral surface that expands from the rear side toward the front side. Therefore, when the hub member is assembled to the atomizing head main body, the diameter is increased. The inner peripheral surface can be easily fitted into the hub fitting concave groove by gradually elastically deforming the leg portion of the hub member. In addition, the paint that has passed through each hole-shaped paint passage flows through the annular paint passage and is supplied to the paint thinning surface.
[0034]
According to the seventh aspect of the present invention, the annular paint passage is formed as an annular paint passage having substantially the same diameter from the rear side toward the front side.
[0035]
With this configuration, the paint that has passed through each hole-shaped paint passage flows through the uniform annular paint passage and is supplied to the paint thinning surface.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a rotary atomizing head type coating apparatus using a rotary atomizing head according to an embodiment of the present invention will be described in detail with reference to FIGS.
[0037]
Reference numeral 1 denotes a cover of a rotary atomizing head type coating apparatus. The cover 1 is formed in a cylindrical shape, and an air motor 2 described later is accommodated in the cover 1.
[0038]
Reference numeral 2 denotes an air motor accommodated in the cover 1, and the air motor 2 is capable of rotating a cylindrical motor casing 2A, an air turbine 2B accommodated in the motor casing 2A, and a rotating shaft 3 described later. And a hydrostatic air bearing 2 C that is pivotally supported on the shaft. And the air motor 2 rotates the rotating shaft 3 by supplying compressed air to the air turbine 2B.
[0039]
Reference numeral 3 denotes a hollow rotary shaft that is rotatably supported by a static pressure air bearing 2C of the air motor 2. The tip of the rotary shaft 3 protrudes to the front side of the air motor 2, and a rotary atomizing head 11 (to be described later) is provided at the tip. Installed. Further, the base end side of the rotating shaft 3 is attached to an air turbine 2 B of the air motor 2.
[0040]
A feed tube 4 is inserted through the rotary shaft 3, and the tip of the feed tube 4 protrudes from the rotary shaft 3 and extends into the rotary atomizing head 11. The feed tube 4 is formed as a coaxial double cylinder, is located in the center, and a paint passage 4A through which paint and thinner as a cleaning fluid circulate, and a thinner etc. located on the outer peripheral side of the paint passage 4A. Is formed by an annular thinner passage 4B. The feed tube 4 supplies the paint from the paint passage 4A toward the rotary atomizing head 11 during the painting operation. Further, at the time of a cleaning operation associated with the color change of the paint or the like, the paint passage 4A supplies thinner or the like for cleaning the front surface of the hub member 14 to be described later, and the thinner passage 4B is a paint thinning surface 12C of the atomizing head main body 12; A thinner or the like for cleaning the discharge edge 12D or the like is supplied.
[0041]
Reference numeral 5 denotes a shaping air ring attached to the tip of the cover 1. The shaping air ring 5 is formed in a cylindrical shape, and controls the spray pattern of the paint sprayed from the rotary atomizing head 11 on the tip side. A plurality of air outlets 5A, 5A,...
[0042]
Next, reference numeral 11 denotes a rotary atomizing head according to the present embodiment attached to the tip of the rotary shaft 3. The rotary atomizing head 11 includes an atomizing head main body 12 and a hub fitting, which will be described later, as shown in FIG. The groove is roughly constituted by the groove 13, the hub member 14, the hole-shaped paint passage 19, the annular paint passage 20, and the like.
[0043]
Reference numeral 12 denotes an atomizing head main body formed in a bell shape that has an outer shape of the rotary atomizing head 11 and expands from the rear side toward the front side. The atomizing head main body 12 is, for example, an aluminum alloy or a stainless alloy. It is formed using a hard resin material or the like. Here, when the atomizing head main body 12 is formed of a resin material, a conductive resin material having conductivity, or a non-conductive resin material having a surface coated with a conductive paint is used. . Thereby, since a high voltage can be applied to the atomizing head main body 12 when painting, the atomizing head main body 12 can directly charge the paint flowing on the surface to the high voltage. it can.
[0044]
The atomizing head main body 12 has a cylindrical rotating shaft mounting portion 12A on the rear end side, and a female screw 12A1 that is screwed to the rotating shaft 3 of the air motor 2 is engraved at the back of the rotating shaft mounting portion 12A. ing. The atomizing head main body 12 is formed with an annular partition 12B projecting radially inward so as to close the inner part of the rotating shaft mounting portion 12A, and the rotating shaft 3 is formed on the inner peripheral side of the annular partition 12B. The tip of the feed tube 4 that protrudes from the tip side is inserted.
[0045]
On the other hand, the front side of the atomizing head main body 12 is a paint thinning surface 12C that expands in a disc shape, and the front end (outer peripheral end) of the atomizing head main body 12 is a discharge edge 12D that is continuous with the paint thinning surface 12C. It has become. Further, the atomizing head main body 12 is provided with a paint reservoir 12E between the annular partition wall 12B and a hub member 14 to be described later, located on the back side, and the paint reservoir 12E is discharged from the feed tube 4. A space where paint is temporarily stored and diffused. Furthermore, the inner peripheral surface 12F of the atomizing head main body 12 located between the paint reservoir 12E and the paint thinning surface 12C has a diameter-expanded inner periphery that is expanded from the rear side toward the front side as shown in FIG. It is formed as a surface. Further, the inner diameter dimension D1 of the front end portion (boundary portion with the paint thinning surface 12C) of the enlarged inner peripheral surface 12F whose diameter is enlarged on the front side is set to be larger than the maximum inner diameter dimension D2 of the hub fitting groove 13 described later. (D1> D2).
[0046]
When the paint is supplied to the paint reservoir 12E in a state where the rotary atomizing head 11 is rotating at high speed, the atomizing head main body 12 passes the paint from the hole-like paint passage 19 described later to the paint thinning surface 12C. To supply. As a result, the paint supplied to the paint thinning surface 12C is sprayed as paint particles from the discharge edge 12D.
[0047]
Reference numeral 13 denotes a hub fitting concave groove provided on the inner peripheral surface 12F of the atomizing head main body 12, and the hub fitting concave groove 13 is fitted so that a distal end of a leg portion 17 of a hub member 14 described later can be engaged and detached. It is formed by denting the front and rear intermediate positions of the expanded inner peripheral surface 12F in a circular arc shape over the entire circumference. Further, as shown in FIG. 6, the hub fitting concave groove 13 has a smooth front arc surface 13A and rear arc surface 13B at the boundary with the inner peripheral surface 12F. The arc surfaces 13A and 13B are configured so that when the paint flows from the paint reservoir 12E toward the paint thinning surface 12C, the paint can smoothly get over the hub fitting concave groove 13 without scattering. Yes.
[0048]
Here, the maximum inner diameter dimension D2 of the hub fitting concave groove 13 is set to a dimension larger than the inner diameter dimension D3 at the position of the front arc surface 13A and smaller than the inner diameter dimension D1 of the front end portion of the inner peripheral surface 12F. (D1>D2> D3). The maximum inner diameter D2 of the hub fitting concave groove 13 is set to be the same as or slightly smaller than the maximum outer diameter D6 of the leg portion 17 of the hub member 14 described later (D2 ≦ D6). . Thereby, the hub fitting concave groove 13 can be reliably held without rattling each leg portion 17 of the hub member 14 that fits over the front circular surface 13A.
[0049]
A hub member 14 is detachably attached to the atomizing head main body 12 so as to cover the front of the paint reservoir 12E. The hub member 14 is easily deformed by the action of centrifugal force and has appropriate elasticity and flexibility. Materials such as polyethersulfone (PES), polyphenylene sulfide (PPS), polyetherimide (PEI), polyetheretherketone (PEEK), polyoxymethylene (POM), polyamideimide (PAI), polyethylene terephthalate (PET), It is formed in a substantially disk shape using a resin material such as polyimide (PI). As shown in FIG. 7, the hub member 14 is roughly constituted by a lid portion 15, a leg portion 17, a notch groove 18, and the like which will be described later.
[0050]
15 is a disc-shaped lid portion that forms the main body of the hub member 14, and the lid portion 15 has a flat front surface 15A and a rear surface side that receives paint discharged from the feed tube 4 and is described above. The paint receiving surface 15B closes the paint reservoir 12E. Further, the outer peripheral surface 15C of the lid portion 15 is set such that the outer diameter dimension D4 of the front end portion is larger than the outer diameter dimension D5 of the rear end portion (D4> D5), thereby gradually from the rear side toward the front side. It is formed as a diameter-enlarged outer peripheral surface that increases in diameter. Further, the outer diameter D4 of the front end portion of the lid portion 15 is set smaller than the inner diameter D1 of the front end portion of the enlarged inner peripheral surface 12F of the atomizing head main body 12 (D1> D4). Further, the outer diameter dimension D5 of the rear end portion of the lid portion 15 is smaller than the inner diameter dimension D3 at the position of the front arc surface 13A of the hub fitting concave groove 13 (that is, the rear end position of the enlarged inner peripheral surface 12F). It is set (D3> D5).
[0051]
On the other hand, a conical protrusion 15D protruding rearward is formed at the center of the paint receiving surface 15B in order to smoothly deliver the paint discharged from the feed tube 4. Here, the outer peripheral surface 15 C of the lid portion 15 is attached to the atomizing head main body 12, has a certain gap size with the inner peripheral surface 12 F, and forms an annular paint passage 20 described later.
[0052]
16, 16,... Are four thinner outflow holes provided on the axial center side of the lid portion 15. Each of the thinner outflow holes 16 is drilled from the paint receiving surface 15 B (conical protrusion 15 D) to the front surface 15 A. It is installed. The thinner outflow hole 16 forms a passage for supplying thinner from the paint receiving surface 15B to the front surface 15A side when the paint adhering to the front surface 15A is washed.
[0053]
17, 17,... Are a plurality of leg portions (14 in the case of the embodiment) integrally formed on the outer peripheral side of the rear surface of the lid portion 15, and each leg portion 17, as shown in FIG. One book is formed independently, and is arranged over the entire circumference at equal intervals in the circumferential direction. Further, the leg portion 17 is formed as a diameter-enlarged leg portion that increases in diameter toward the radially outer side as the distance from the outer peripheral side of the rear surface of the lid portion 15 in the direction of the tip portion 17A (the rear side in the axial direction) increases. The maximum outer diameter D6 at the position of the portion 17A is set to be larger than the outer diameter D5 of the rear end portion of the lid portion 15 (D6> D5). Further, the distal end portion 17A of the leg portion 17 has a spherical shape that becomes a free end and substantially matches the hub fitting concave groove 13.
[0054]
Further, the maximum outer diameter D6 of the tip 17A of the leg 17 is formed to be the same as or smaller than the outer diameter D4 of the front end of the lid 15 (D6 ≦ D4). Further, the maximum outer diameter D6 of each leg portion 17 (position of the distal end portion 17A) is set to be the same as or slightly larger than the maximum inner diameter D2 of the hub fitting concave groove 13 (D6 ≧ D2). ).
[0055]
And since each leg part 17 can be elastically deformed comparatively easily by each being independent, the attachment or detachment operation | work with respect to the hub fitting recessed groove 13 can be performed easily. Moreover, since the maximum outer diameter D6 of each leg 17 is set to be the same as or slightly larger than the maximum inner diameter D2 of the hub fitting concave groove 13, each leg 17 is fitted to the hub. It is securely held in the mating groove 13.
[0056]
In view of the above, the inner diameter D1 of the front end portion of the inner peripheral surface 12F of the atomizing head main body 12, the maximum inner diameter D2 of the hub fitting groove 13, and the inner diameter of the hub fitting groove 13 at the position of the front circular surface 13A. The dimension D3, the outer diameter D4 of the front end of the lid 15 of the hub member 14, the outer diameter D5 of the rear end of the lid 15, and the maximum outer diameter D6 of the leg 17 at the position of the tip 17A. The following equation 1 is satisfied.
[0057]
[Expression 1]
D1>D2> D3
D4 ≧ D6> D5
D6 ≧ D2
D1> D4
D3> D5
[0058]
18,... Are a plurality of (14 in the embodiment) cutout grooves formed alternately with the leg portions 17 on the outer peripheral surface of the rear surface of the lid portion 15. It is located between 17 and formed in a substantially U shape, and is arranged over the entire circumference at equal intervals in the circumferential direction. The notch groove 18 is a hole-shaped paint described later between the notch groove 18 and the hub fitting groove 13 when the leg portion 17 of the hub member 14 is fitted into the hub fitting groove 13 of the atomizing head main body 12. A passage 19 is formed.
[0059]
19, 19,... Are formed between the inner peripheral surface of the hub fitting concave groove 13 of the atomizing head body 12 and each notch groove 18 of the hub member 14 when the hub member 14 is mounted in the atomizing head body 12. As shown in FIG. 3, each of the porous paint passages 19 is formed with a plurality of porous paint passages at equal intervals in the circumferential direction as shown in FIG. A number corresponding to 18 is arranged in a row independently. Each of the hole-shaped paint passages 19 rotates the rotary atomizing head 11 at a high speed, and when the paint is supplied from the feed tube 4 to the paint reservoir 12E, the paint is uniformly distributed toward an annular paint passage 20 described later. Is.
[0060]
Further, 20 is formed between the enlarged inner peripheral surface 12F of the atomizing head main body 12 and the outer peripheral surface 15C of the lid portion 15 of the hub member 14 when the hub member 14 is mounted in the atomizing head main body 12. As shown in FIGS. 2 and 4, the annular paint passage 20 has an annular shape over the entire circumference, and gradually advances from the rear side to the front side by the inner peripheral surface 12F and the outer peripheral surface 15C. The diameter is expanded to increase the diameter. As a result, the annular paint passage 20 having an enlarged diameter can uniformly distribute the paint between the enlarged inner peripheral surface 12F of the atomizing head main body 12 and the outer peripheral surface 15C of the lid portion 15. Thinner can be distributed so as to contact 15C and 12F.
[0061]
Here, the width dimension a (illustrated in FIG. 2) of the annular paint passage 20 is in the relationship of the following formula 2 on the front end side.
[0062]
[Expression 2]
a ≒ (D1-D4) / 2
[0063]
The rotary atomizing head 11 according to the present embodiment has the above-described configuration. Next, the assembly operation of the rotary atomizing head 11, the painting operation by the rotary atomizing head 11, and the removal of pigments and the like in the fixed paint (Disassembly) work will be described.
[0064]
First, the assembly work of the rotary atomizing head 11, that is, the work of assembling the hub member 14 to the atomizing head main body 12 will be described.
[0065]
First, the hub member 14 is applied so as to cover the paint reservoir 12E of the atomizing head main body 12, and the hub member 14 is pressed to be pushed into the paint reservoir 12E side. At this time, since the inner diameter dimension D1 of the front end of the enlarged diameter inner peripheral surface 12F of the atomizing head main body 12 is set larger than the maximum outer diameter dimension D6 of each leg portion 17, the hub member 14 is fogged. It can be positioned in the center of the chemical head body 12. Moreover, since the diameter of the enlarged inner peripheral surface 12F gradually decreases from the front side toward the rear side, each leg portion 17 of the hub member 14 can be gradually elastically deformed, and the front arc surface 13A can be By getting over, it can be easily fitted into the hub fitting concave groove 13. Further, since one leg portion 17 is independent of each other, the leg portions 17 can be bent relatively easily and can be easily fitted into the hub fitting concave groove 13.
[0066]
Each of the leg portions 17 of the hub member 14 fitted in the hub fitting concave groove 13 has a maximum outer diameter D6 that is the same as or slightly larger than the maximum inner diameter D2 of the hub fitting concave groove 13. Therefore, each leg portion 17 matches the hub fitting groove 13 and is securely held.
[0067]
Next, a description will be given of a painting operation in which paint is sprayed onto an object to be coated using the rotary atomizing head 11 assembled in this way.
[0068]
First, the rotary atomizing head 11 is rotated together with the rotating shaft 3 by the air motor 2 at a high speed, for example, 3000 to 100000 rpm. At this time, centrifugal force acts on the atomizing head main body 12 and the hub member 14 of the rotary atomizing head 11, but each leg portion 17 of the hub member 14 is formed independently and is easily elastically deformed. Therefore, the leg portions 17 of the hub member 14 are larger in the radial direction than the atomizing head main body 12. Thereby, since each said leg part 17 is strongly pressed by the hub fitting recessed groove 13, the holding | maintenance state of the hub member 14 by the hub fitting recessed groove 13 can be improved further.
[0069]
When the paint is supplied from the feed tube 4 to the paint receiving surface 15B of the hub member 14, the paint supplied to the paint receiving surface 15B passes through the hole paint passage 19 and the annular paint passage 20 from the paint reservoir 12E by centrifugal force. It flows out to the paint thinning surface 12C of the atomizing head main body 12 through. At this time, since each hole paint passage 19 is independently formed at equal intervals over the entire circumference on the outer peripheral side of the lid portion 15, the paint supplied to the paint reservoir 12 E is supplied to each hole paint passage 19. Out uniformly. Moreover, since the annular paint passage 20 is formed with a substantially constant width dimension a, the paint can be distributed uniformly over the entire circumference. As a result, the paint supplied to the paint thinning surface 12C is sprayed as paint particles from the discharge edge 12D and is applied to the object to be coated.
[0070]
At the time of painting, a high voltage supplied from a high voltage generator (not shown) is applied to the rotary atomizing head 11 to directly charge the paint flowing on the surface of the atomizing head main body 12 to a high voltage. Therefore, the charging efficiency can be increased by flying the charged paint toward the object to be coated.
[0071]
Next, the color change operation in the case where the previous color coating is completed and the next color paint is changed will be described.
[0072]
First, when the color of the paint is changed, so-called automatic washing is performed to wash the paint of the previous color adhering to each part. In this automatic cleaning operation, with the rotary atomizing head 11 rotated, the thinner is supplied to the paint passage 4A of the feed tube 4 to discharge the previous color paint, and then the thinner passage 4B is moved to the rotary atomizing head 11. Supply thinner etc. that will be the cleaning fluid. At this time, the annular paint passage 20 is formed with a substantially constant width dimension a, and is formed with an enlarged diameter so that the diameter gradually increases toward the front side. Can also supply thinner.
[0073]
Thereby, the thinner which distribute | circulates the cyclic | annular coating material channel | path 20 can wash | clean the forecolor coating material adhering to the diameter expansion inner peripheral surface 12F of the atomization head main body 12, and the outer peripheral surface 15C of the hub member 14 efficiently. The thinner flowing out from the hole-shaped paint passage 19 cleans the paint adhering to the paint thinning surface 12C and the discharge edge 12D of the atomizing head main body 12, and the thinner flowing out from the thinner outflow hole 16 becomes the hub member 14. The front surface 15A can be cleaned.
[0074]
On the other hand, the paint adhering to the notch grooves 18 of the hub member 14, the gaps between the hub fitting concave grooves 13 and the respective leg portions 17 cannot be removed by the automatic cleaning operation described above. For this reason, the pigment component etc. which are contained in the adhering paint gradually accumulate in the notch groove 18 of the hub member 14 and become a fixed matter. For this reason, this fixed thing decomposes | disassembles the rotary atomization head 11, and removes it in this decomposition | disassembly state. Therefore, the disassembling operation of the rotary atomizing head and the removing operation of the fixed matter will be described.
[0075]
First, when removing the hub member 14 from the atomization head main body 12, the rotation atomization head 11 is removed from the rotating shaft 3 prior to this. Next, a rod-shaped disassembly jig (not shown) is inserted into the rotary shaft mounting portion 12A of the atomizing head main body 12, and the hub member 14 is pressed from the rear side by the jig. At this time, for example, even when the pigment or the like in the paint is fixed and fixed between the leg portion 17 and the hub fitting concave groove 13, each leg portion 17 is formed independently and elastic. Since it is easy to deform, the hub member 14 can be easily removed from the hub fitting concave groove 13 while elastically deforming the leg portion 17.
[0076]
In the state where the hub member 14 is removed from the atomizing head main body 12 in this way, each of the hole-shaped paint passages 19 includes a hub fitting groove 13 on the atomizing head main body 12 side and a notch groove 18 on the hub member 14 side. Therefore, the fixed object can be easily removed by rubbing the hub fitting concave groove 13 and the notch groove 18 with a brush or the like. In addition to the above, it is difficult to clean the atomized head main body 12 which is difficult to clean, and the fixed matter deposited and adhered to the paint wetted parts such as the inner peripheral surface 12F, the outer peripheral surface 15C of the hub member 14 and the leg 17 The fitting groove 13 and the notch groove 18 can be easily removed.
[0077]
Thus, according to the present embodiment, the atomizing head main body 12 is formed using a metal material or a hard resin material, and the hub member 14 is formed using a resin material having appropriate elasticity and flexibility. . Further, a hub fitting concave groove 13 is provided on the diameter-enlarged inner peripheral surface 12F of the atomizing head main body 12, and a leg portion 17 is fitted to the hub member 14 so as to be engaged with and detached from the hub fitting concave groove 13. Is provided. Thus, when the hub member 14 is attached to the atomizing head main body 12, the hub member 14 is applied to the inner peripheral surface 12F of the atomizing head main body 12, and the leg member 17 is elastically deformed by pressing the hub member 14. However, it can be fitted into the hub fitting concave groove 13.
[0078]
As a result, when the rotary atomizing head 11 is rotated at a high speed, the hub member 14 formed using a resin material having appropriate elasticity and flexibility strongly presses the leg portion 17 against the hub fitting concave groove 13. Therefore, the holding force of the leg portion 17 in the hub fitting concave groove 13 can be increased, and the hub member 14 can be prevented from dropping off and the reliability of the rotary atomizing head 11 can be improved. Can be improved. Moreover, the rotation balance of the hub member 14 can be stabilized over a long period of time.
[0079]
On the other hand, it is difficult to remove by the automatic cleaning operation, and the fixed matter such as the pigment deposited and fixed in the notch groove 18 of the hub member 14, the gap between the hub fitting concave groove 13 and each leg portion 17 is removed. In this case, the hub member 14 can be easily removed from the atomizing head body 12 by pressing the hub member 14 from the rotating shaft mounting portion 12A side of the atomizing head body 12 using a disassembly jig. it can. In this state, the hole-shaped paint passage 19 can be separated into the hub fitting concave groove 13 on the atomizing head main body 12 side and the notch groove 18 on the hub member 14 side. By rubbing the concave groove 13 and the notch groove 18, it is possible to easily remove the fixed matter fixed to each part and improve workability.
[0080]
Further, since the annular coating passage 20 is formed with a substantially constant width dimension a, when coating is performed, the coating can be uniformly distributed over the entire circumference, and the coating quality can be improved. On the other hand, when cleaning the paint, the paint adhering to the inner peripheral surface 12F of the atomizing head main body 12 and the outer peripheral surface 15C of the hub member 14 can be efficiently cleaned by the thinner, and the cleaning efficiency can be improved. .
[0081]
Moreover, since each leg part 17 of the hub member 14 is formed independently, it can be easily elastically deformed when fitted into or removed from the hub fitting groove 13. Thereby, as described in the prior art, for example, even when a fixed object such as a pigment is fixed to the hole-shaped paint passage 19 between the leg portion 17 and the hub fitting concave groove 13, the hub member 14 is It can be detached and attached only with the force of the fingertip, and can be easily attached and detached.
[0082]
Furthermore, since the hub fitting concave groove 13 has smooth arc surfaces 13A and 13B at the boundary with the enlarged inner peripheral surface 12F, the paint flowing from the paint reservoir 12E toward the paint thinning surface 12C The hub fitting concave groove 13 can be smoothly passed over without scattering at the boundary portion. Thereby, the arc surfaces 13A and 13B can improve the coating quality by smoothing the flow of the paint in the atomizing head main body 12.
[0083]
Further, the inner peripheral surface 12F of the atomizing head main body 12 is also expanded from the rear side to the front side by the enlarged annular paint passage 20 whose diameter increases from the rear side to the front side. Therefore, when the hub member 14 is attached to the atomizing head main body 12, the hub member 14 can be positioned at the center of the atomizing head main body 12, and the attaching operation can be performed easily and accurately. Can do.
[0084]
On the other hand, since each leg portion 17 of the hub member 14 is easily elastically deformed by an independent shape, even when the hub member 14 is formed of the same metal material as the atomizing head body 12, a hard resin material, etc. Each leg portion 17 can be easily bent, and a sufficient holding force can be obtained in the hub fitting concave groove 13.
[0085]
In the embodiment, between the atomizing head main body 12 and the hub member 14, an enlarged inner peripheral surface 12 F of the atomizing head main body 12 whose diameter is gradually increased from the rear side toward the front side. The case where the annular paint passage 20 having an enlarged diameter is formed by the outer peripheral surface 15C of the lid portion 15 has been described as an example.
[0086]
However, the present invention is not limited to this. For example, a rotary atomizing head 31 such as a modification shown in FIG. 9 may be used. In this case, the rotary atomizing head 31 includes a rotary shaft attachment portion 32A, an annular partition wall 32B, a paint thin film surface 32C, a discharge end edge 32D, a paint reservoir 32E, and an inner peripheral surface 32F. Between the atomizing head main body 32 provided with the concave groove 33, the hub member 34 including the lid portion 35, the thinner outflow hole 36, the leg portion 37, and the cutout groove 38, and between the hub fitting concave groove 33 and the cutout groove 38. And the hole-shaped paint passage 39. A uniform diameter annular paint passage 40 having a substantially equal diameter dimension from the rear side to the front side is provided between the uniform diameter inner peripheral face 32F having substantially the same diameter dimension and the outer peripheral face 35C of the lid portion 35. It is good also as a structure which forms.
[0087]
Therefore, according to this modification, the uniform diameter annular paint passage 40 can supply the paint that has passed through the hole-like paint passage 39 to the paint thinning surface 32C. Further, when the thinner or the like is supplied, the paint adhering to the annular paint passage 40 can be washed.
[0088]
Further, in the embodiment, the hub member 14 is illustrated with an example in which each of the 14 leg portions 17 is provided. However, the present invention is not limited to this, and the leg portion 17 causes the hub member 14 to be fogged. The number which can be supported by the chemical head main body 12, that is, three or more in the circumferential direction may be provided. When the number of the leg portions 17 is small, the hole-like paint passage is a slit-like long hole extending in the circumferential direction.
[0089]
On the other hand, in the embodiment, the atomizing head main body 12 of the rotary atomizing head 11 is formed of a metal material or a conductive resin material, and the paint is directly charged to a high voltage via the atomizing head main body 12 or the like. However, the present invention is not limited to this. For example, an external electrode is provided on the outer peripheral side of the cover 1, and the external electrode is a rotary atomizing head. 11 may be applied to an indirect charging type rotary atomizing head type coating apparatus that indirectly charges a paint sprayed from 11 to a high voltage.
[0090]
Furthermore, in the embodiment, the case where the atomizing head main body 12 is formed in a bell shape is exemplified, but the atomizing head main body has a cylindrical shape gradually increasing in diameter from the rotating shaft mounting portion toward the discharge edge. It may be formed.
[0091]
【The invention's effect】
As described in detail above, according to the first aspect of the present invention, the atomizing head main body has a hub formed in the shape of a concave groove on the entire inner peripheral surface between the paint reservoir and the paint thinning surface. The fitting groove is provided, and the hub member is the inner peripheral surface of the atomizing head main body. Compared to the inner diameter of the part located between the front end of the hub fitting concave groove and the paint thin film surface A plurality of lids made of a small-diameter disk-like body, and a plurality of fittings that are provided extending from the lid to the rear side in the axial direction and that engage and detachably engage with the hub fitting concave groove while elastically deforming the tip. When the leg portion of the hub member is fitted in the hub fitting concave groove, the hub portion is formed by a leg portion of the book and a plurality of cutout grooves provided between the adjacent leg portions. A plurality of hole-shaped paint passages are formed between the fitting concave grooves and the respective cutout grooves, and an annular paint passage is formed between the inner peripheral surface of the atomizing head main body and the outer peripheral surface of the lid portion. .
[0092]
Therefore, a hub member is applied so as to cover the paint reservoir of the atomizing head main body, and each leg portion of the hub member is elastically deformed by pushing the hub member into the atomizing head main body. At this time, since each leg is independent, it can be elastically deformed relatively easily inward in the radial direction on the inner peripheral surface of the atomizing head main body, and the diameter is increased by the hub fitting concave groove. It can be fitted into the hub fitting groove. Thereby, each leg part can engage a hub member with a hub fitting concave groove with the elastic force, and can hold | maintain it in a retaining state. When the rotary atomizing head is rotated at a high speed, each leg portion of the hub member attempts to expand its diameter by centrifugal force, so that each leg portion firmly supports the hub member in the atomizing head main body. Therefore, it is possible to prevent the hub member from dropping off and improve the reliability of the rotary atomizing head.
[0093]
Further, the hub member is formed in a state where it is fitted in the hub fitting concave groove, and a hole-shaped paint passage is formed between each notch groove and the hub fitting concave groove, and the lid portion Outer peripheral surface An annular paint passage is formed between the inner peripheral surface of the atomizing head main body. Thereby, when painting, by supplying the paint to the paint reservoir, the paint can be uniformly discharged from the paint reservoir to the paint thinning surface through each hole paint passage and the annular paint passage, It is possible to fly as uniform paint particles from the discharge edge and improve the coating quality of the object to be coated.
[0094]
In addition, when removing fixed matters such as pigments in the paint deposited and fixed in each hole paint passage, annular paint passage, etc., the rear surface of the hub member from the rotating shaft mounting portion side of the atomizing head main body to the front side Press on. This makes it easy to elastically deform each leg, even when a fixed object is stuck in the gap between the hub fitting concave groove and the leg, in the same manner as when the hub member is pushed into the atomizing head body. Thus, the hub member can be removed from the hub fitting concave groove. When the hub member is removed from the atomizing head main body, the hole-shaped paint passage is divided into a notch groove in the hub member and a hub fitting concave groove in the atomizing head main body. It is possible to easily remove pigments and other sticking objects stuck to the grooves and hub fitting concave grooves, and to deposit on paint wetted parts such as the inner peripheral surface of the atomizing head body and the paint receiving surface of the hub member. The fixed object that has been fixed can be easily removed, and workability can be improved.
[0095]
According to the invention of claim 2, the leg portions and the notch grooves are alternately formed on the outer peripheral side of the lid portion, and the hole-shaped paint passages are independently formed between the notch grooves and the hub fitting recess grooves. It is configured to do. As a result, the paint supplied to the paint reservoir uniformly flows out from the respective hole-shaped paint passages and out into the annular paint passage, so that it can be applied to the object as uniform paint particles.
[0096]
According to the invention of claim 3, the annular paint passage is formed in an annular shape over the entire circumference between the inner peripheral surface of the atomizing head main body and the outer peripheral surface of the lid portion of the hub member. The passages can supply the paint that has passed through the respective hole-like paint passages to the paint thinning surface.
[0097]
According to the invention of claim 4, each leg portion is formed as a diameter-enlarged leg portion that increases in diameter toward the radially outer side as it is separated from the position of the lid portion in the direction of the tip portion. When pushed into the atomizing head main body, each leg portion can reliably fit the distal end portion located on the outermost side in the radial direction into the hub fitting concave groove.
[0098]
According to the invention of claim 5, since the boundary portion between the hub fitting concave groove and the inner peripheral surface of the atomizing head main body is formed as a smooth arc surface, the paint or the like is applied from the paint reservoir to the paint thin film. The arc surface can flow smoothly without splashing this paint, etc. when flowing over the hub fitting concave groove toward the control surface, stabilizing the supply of paint, and improving the coating quality. Can be improved.
[0099]
According to the invention of claim 6, since the annular paint passage is formed as an annular paint passage whose diameter gradually increases from the rear side to the front side, the inner peripheral surface of the atomizing head main body is from the rear side. Since the inner peripheral surface expands toward the front side, the expanded inner peripheral surface can be easily fitted into the hub fitting concave groove by gradually elastically deforming the leg portion of the hub member. Workability can be improved. Further, the annular paint passage can supply the paint that has passed through each hole-like paint passage to the paint thin film surface.
[0100]
According to the seventh aspect of the present invention, since the annular paint passage is formed as an annular paint passage having substantially the same diameter from the rear side to the front side, the annular paint passage passes through each porous paint passage. The applied paint can be supplied to the paint thinning surface, and when the cleaning fluid is supplied, the paint attached to the annular paint passage can be cleaned.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rotary atomizing head type coating apparatus provided with a rotary atomizing head according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view showing a rotary atomizing head in FIG. 1 in an enlarged manner.
3 is an enlarged cross-sectional view of a main part when viewed from the direction of arrows III-III in FIG. 2;
4 is an enlarged cross-sectional view of a main part when viewed from the direction of arrows IV-IV in FIG. 2. FIG.
FIG. 5 is an exploded cross-sectional view showing the atomizing head main body and the hub member in an exploded manner.
FIG. 6 is an enlarged cross-sectional view of a main part showing an enlarged vicinity of a hub fitting concave groove.
FIG. 7 is an enlarged front view showing a hub member as a single unit.
8 is a right side view of the hub member as seen from the direction of arrows VIII-VIII in FIG. 7. FIG.
FIG. 9 is an enlarged cross-sectional view of a rotary atomizing head according to a modification of the present invention as seen from the same position as in FIG.
[Explanation of symbols]
11,31 Rotating atomizing head
12, 32 Atomizing head body
12A, 32A Rotating shaft mounting part
12C, 32C Paint thin film surface
12D, 32D discharge edge
12E, 32E Paint reservoir
12F, 32F Inner peripheral surface
13,33 Hub fitting groove
13A, 13B Arc surface
14, 34 Hub member
15, 35 lid
15C, 35C outer peripheral surface
17, 37 legs
17A Tip
18, 38 Notch groove
19,39 Porous paint passage
20, 40 Annular paint passage

Claims

It is formed in a cylindrical shape or a bell shape, and the rear end side becomes a rotary shaft mounting portion (12A, 32A) for mounting on the rotary shaft, and the front side of the inner peripheral surface (12F, 32F) faces the discharge end edge (12D, 32D) . The atomizing head main body (12 , 32) having a paint thinning surface (12C, 32C) and a paint reservoir (12E, 32E) on the back side , and the paint reservoir (12E, 32E). A rotary atomizing head ( 11, 31 ) comprising a hub member (14, 34) removably attached to the inner peripheral surface (12F, 32F) of the atomizing head main body (12, 32) so as to cover the front of the head. )
The atomizing head main body (12 , 32) is recessed over the entire circumference on the inner peripheral surface (12F, 32F) between the paint reservoir (12E, 32E) and the paint thinning surface (12C, 32C). Provide hub fitting concave grooves (13, 33) formed in a groove shape,
The hub member (14, 34) includes a front end of the hub fitting groove (13, 33) and a paint thinning surface ( of the inner peripheral surface (12F, 32F) of the atomizing head body (12, 32)). 12C, the lid portion comprising a small-diameter disk-shaped member compared to the inner diameter of a portion located between the 32C) and (15, 35), extends behind the lid portion from the (13, 35) in the axial direction a plurality of legs and (17, 37), adjacent each leg distal end portion is provided which fits into engagement detachably the hub fitting groove while being elastically deformed (13, 33) Te (17 , 37) and a plurality of notch grooves (18 , 38) provided between,
Wherein when the leg portions of the hub member (14, 34) and (17, 37) fitted to said hub fitting groove (13, 33), each notched groove and the hub fitting groove (13, 33) (18, 38) and a plurality of porous paint passages (19, 39) are formed between the inner peripheral surface (12F, 32F) of the atomizing head body (12, 32 ) and the lid (15, 35) A rotary atomizing head characterized in that an annular paint passage (20, 40) is formed between the outer peripheral surface (15C, 35C) of 35) .

The leg portions (17, 37) and the notch grooves (18, 38) are alternately formed on the outer peripheral side of the lid portion (15, 35) , and the hole-shaped paint passages (19, 39) are formed in the notch portions. The rotary atomizing head according to claim 1, wherein the rotary atomizing head is formed independently between the groove (18, 38) and the hub fitting concave groove ( 13, 33).

The annular paint passage (20, 40) is formed between the inner peripheral surface (12F, 32F) of the atomizing head body (12, 32) and the outer peripheral surface (15C, 35C) of the lid portion of the hub member (14, 34) . The rotary atomizing head according to claim 1, wherein the rotary atomizing head is formed in an annular shape all around.

Each said leg part (17, 37) is formed as a diameter expansion leg part diameter-expanded toward a radial direction outer side as it leaves | separates in the direction of a front- end | tip part from the position of the said cover part (15, 35). The rotary atomizing head according to 1, 2 or 3.

The boundary between the hub fitting concave groove (13, 33) and the inner peripheral surface (12F, 32F) of the atomizing head main body (12, 32) is formed as a smooth arc surface. , 2, 3 or 4.

The rotary atomizing head according to claim 1, 2, 3, 4, or 5, wherein the annular paint passage (20) is formed as an annular paint passage having a diameter that gradually increases from the rear side toward the front side.

The rotary atomizing head according to claim 1, 2, 3, 4, or 5, wherein the annular paint passage (40) is formed as an annular paint passage having substantially the same diameter from the rear side toward the front side.