JP2004298734A

JP2004298734A - Coating drying oven

Info

Publication number: JP2004298734A
Application number: JP2003094229A
Authority: JP
Inventors: Takeshi Sakamaki; 剛坂巻; Shingo Sano; 信吾佐野
Original assignee: Kanto Jidosha Kogyo KK; Toyota Motor Corp; Kanto Auto Works Ltd
Current assignee: Kanto Jidosha Kogyo KK; Toyota Motor Corp; Toyota Motor East Japan Inc
Priority date: 2003-03-31
Filing date: 2003-03-31
Publication date: 2004-10-28
Anticipated expiration: 2023-03-31
Also published as: JP4472938B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating drying oven wherein the temperature of a car body (a drying object) is uniformly raised and the inside of a drying oven is easily cleaned. <P>SOLUTION: A returning section 8 is formed at the upper end of each of ceiling panels of a ceiling 7. Therefore, the flow direction of an air current flowing along each ceiling panel from the upper end of each ceiling panel toward the lower end is converted by each returning section 8 to form an air current which flows from about the center of the ceiling 7 through both the sides of the car body 1 toward the underside of the car body 1 in the drying oven. Thus, the temperature of the car body 1 is uniformly raised by circulating the air for drying to under the car body 1, while, in a conventional drying oven, the air (air current) for drying is hardly circulated to under the car body 1. Since the inside surface 7a of the ceiling 7 is coated with a fluororesin, a viscous contaminant or the like adhering to the inside surface 7a can be easily removed, enabling the drying oven 4 to be easily cleaned. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車の車体の塗装ライン等に用いられるトンネル式の塗装乾燥炉に関する。
【０００２】
【従来の技術】
一般に、自動車の塗装ラインに組み込まれる塗装乾燥炉（以下、単に乾燥炉と称す）は、輻射式乾燥炉と対流式乾燥炉とが組み合わされて構成されている。上記輻射式乾燥炉は、乾燥炉内に両側壁に沿って放熱ダクトが設けられ、該放熱ダクトに燃焼装置を通過させて昇温させた空気が導入されている。そして、輻射式乾燥炉は、乾燥炉内が放熱ダクトの放射熱（輻射熱）により昇温されて所要温度（塗料を乾燥させるのに適した温度）に維持されている。また、上記対流式乾燥炉は、乾燥炉内の一側壁に吹出しダクトが配置されると共に他側壁に吸気ダクトが配置され、吸気ダクトから吸い込まれた空気が燃焼装置により加熱されて吹出しダクトから乾燥炉内へ吹出される。そして、対流式乾燥炉は、輻射式乾燥炉と比較して熱効率が高い反面、乾燥炉内の空気が循環されるため、塗膜が未硬化の状態であると塗装面（車体の外観面）に空気中の塵埃が付着して車体に外観不良が生じる虞がある。
【０００３】
従って、乾燥炉は、対流式乾燥炉と比較して熱効率が低いが車体の外観品質が確保される輻射式乾燥炉が乾燥炉の入口側に設置されている。そして、乾燥炉の出口側には対流式乾燥炉が設置され、対流式乾燥炉には塗膜が適度（塗装面に塵埃が付着しない程度）に乾燥された車体が搬入される。ところで、自動車の塗装に多く使用されている熱硬化性塗料は、所定温度以上を所定時間だけ保持することで硬化する。従って、乾燥炉は、複雑な形状の車体（塗装面）を均一に昇温させて部位による温度差を最小限に抑制することが必要となる。しかしながら、輻射式乾燥炉においては、放射ダクトと対向するフェンダパネル、ドアパネル等と、その他の部位、特にルーフ、フードパネル等とを比較すると、昇温速度に大きな差があり、車体全体を均一に昇温させるのが困難であった。
【０００４】
そこで、車体を均一に昇温させる目的で、天井がアーチ状に形成された乾燥炉が特許文献１に記載されている。天井がアーチ状に形成された場合、乾燥炉は、乾燥炉内の無駄な容積が省かれて当該乾燥炉内の空気を乾燥に向けて効果的に循環させることができる。しかしながら、天井部分は、車体を懸持して塗装ライン上を搬送するハンガーとの干渉を回避させる必要があるため、車体から比較的離れた位置に配置されている。これにより、従来の乾燥炉は、乾燥炉内の乾燥炉幅方向中央に生じる上昇気流がアーチ状に形成された天井に沿って車体から離れた位置で下降され、乾燥用空気が車体の下側部分に効果的に供給することができなかった。特に、従来の乾燥炉は、ロッカーの下面の昇温速度が他の部位と比較して小さくなる傾向があり、車体の下部の昇温速度を高めて車体をより均一に昇温することが必要である。
【０００５】
また、従来の乾燥炉は、内壁面が亜鉛めっき鋼鈑で形成されているため、内壁面に塗膜から蒸発した有機溶剤成分等がヤニ状になって付着する。そして、内壁面に付着したヤニ状の汚染物質が塗装面に付着した場合、車体に外観不良を引き起こす原因になるため、乾燥炉内の清掃を定期的に行う必要がある。しかしながら、ヤニ状の汚染物質は乾燥炉の内壁面にこびりついているため、その清掃には多大な時間と労力を要し、維持コストを増大させる要因になっていた。さらに、天井にこびりついたヤニ状の汚染物質を清掃するのは上を向いての作業となるため、作業者への負担が大きく改善が要望されていた。
【０００６】
【特許文献１】
実用新案登録第２５０１４２７号公報（第３頁左欄１８行目〜第４頁左欄９行目、第２図）
【０００７】
【発明が解決しようとする課題】
そこで本発明は、上記事情に鑑みてなされたもので、車体（被乾燥物）が均一に昇温されると共に乾燥炉内の清掃が容易な塗装乾燥炉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】
上記目的を達成するために、本発明のうち請求項１に記載の発明は、トンネル式の塗装乾燥炉であって、天井の断面がアーチ状に形成され、天井に乾燥炉内を循環する気流を方向転換させる返り部が設けられることを特徴とする。
【０００９】
請求項２に記載の発明は、請求項１に記載の発明において、返り部に該返り部で方向転換させた直後の気流が通過する集塵フィルタが設けられることを特徴とする。
【００１０】
請求項３に記載の発明は、請求項１又は２に記載の発明において、内壁面が弗素樹脂コーティング処理されることを特徴とする。
【００１１】
請求項４に記載の発明は、請求項１〜３のいずれかに記載の発明において、天井が開閉可能であることを特徴とする。
【００１２】
請求項５に記載の発明は、請求項１〜４に記載の発明において、被乾燥物の下方に所定温度の水が所定流量で流下する流水パンが設けられることを特徴とする。
【００１３】
請求項６に記載の発明は、請求項５に記載の発明において、流水パンの底部に突起が設けられることを特徴とする。
【００１４】
上記目的を達成するために、本発明のうち請求項７に記載の発明は、トンネル式の塗装乾燥炉であって、被乾燥物の下方に所定温度の水が所定流量で流下する流水パンが設けられることを特徴とする。
【００１５】
従って、請求項１に記載の発明では、返り部により乾燥炉内を循環する気流が方向転換されて乾燥炉内に被乾燥物を均一に乾燥するのに適した気流を形成することができる。
【００１６】
請求項２に記載の発明では、乾燥炉内の乾燥用空気を効率よく清浄化することができる。
【００１７】
請求項３に記載の発明では、内壁面に付着したヤニ状の汚染物質を容易に取り除くことが可能になる。
【００１８】
請求項４に記載の発明では、天井を開いた状態で清掃を行うことができる。
【００１９】
請求項５に記載の発明では、乾燥炉の床面に垂れ落とされた汚染物質が流水パンを流下する流水により乾燥炉外へ搬送されて乾燥炉内がクリーンに保たれる。また、流水パンに所定温度の流水を所定流量で流下させることで、被乾燥物の下部が効果的に昇温されて被乾燥物全体が均一に昇温される。
【００２０】
請求項６に記載の発明では、流水が突起を通過することで攪拌され、流水に酸素が取り込まれて流水を活性化させることができる。この活性化された流水を回収して水洗工程で再利用することで、洗浄水の洗浄効果を高めることが可能になる。
【００２１】
請求項７に記載の発明では、乾燥炉の床面に垂れ落とされた汚染物質が流水パンを流下する流水により乾燥炉外へ搬送されて乾燥炉内がクリーンに保たれる。また、流水パンに所定温度の流水を所定流量で流下させることで、被乾燥物の下部が効果的に昇温されて被乾燥物全体が均一に昇温される。
【００２２】
【発明の実施の形態】
本発明の一実施の形態を図１〜図６に基づいて説明する。図２に本塗装乾燥炉３（以下、単に乾燥炉３と称す）の概略構成を示す。この図に示されるように、本乾燥炉３は、当該乾燥炉３の入口側（図２における紙面視右側）に本輻射式乾燥炉４が配置され、また乾燥炉３の出口側（図２における紙面視左側）には本対流式乾燥炉５が配置されている。そして、車体１（被乾燥物）は、搬送用ハンガ２で懸持された状態で、乾燥炉４，５内を図２における紙面視左方向へ所定速度で搬送されて、塗膜が乾燥して焼き付けられる構造になっている。図１に示すように、本輻射式乾燥炉４は、乾燥炉幅方向（図１における紙面視左右方向）両側に放熱ダクト６が配置され、該放熱ダクト６の放熱面６ａにより乾燥炉４の内壁面のうち側部が形成されている。
【００２３】
また、図１に示すように、本輻射式乾燥炉４は、天井７が乾燥炉幅方向（図１における紙面視左右方向）両側に分割された各天井パネルで構成され、各天井パネルが断面が弧状に形成されて天井全体でアーチ状に形成されている。また、各天井パネルは、各下端部が上記放熱ダクト６の上部にヒンジを介して接続され、該ヒンジの回りに回動可能な構造になっている。そして、本輻射式乾燥炉４は、乾燥炉４の内壁面の上部を形成する各天井パネルの内側面７ａに弗素樹脂コーティング処理が施され、各天井パネルの内側面７ａに付着するヤニ状の汚染物質が各天井パネルにこびりつくのが防止されている。なお、図２に示すように、各放熱ダクト６には熱風供給装置１０により熱風が給排（循環）されている。また、図１に示すように、本輻射式乾燥炉４は、天井７の各天井パネルの内側面７ａの上端部に、車体搬送方向（図１における紙面視方向）へ延びて断面が略三角形状に形成された返り部８が設けられている。
【００２４】
これにより、本輻射式乾燥炉４は、乾燥炉内の乾燥炉幅方向（図１における紙面視左右方向）中央から天井７の各天井パネルに沿って各天井パネルの下端部へ向けて流れる気流が図１に示されるように方向転換され、車体１の側面に沿うように流れて車体１の下部に到達するように返り部８の返り角度θが設定されている。なお、本実施の形態においては、上記返り部８の返り角度θが２８〜３０度に設定されている。また、本輻射式乾燥炉４は、天井７の各天井パネルに設けられた各返り部８の各返り面８ａの下流側端部に集塵フィルタ９が設けられている。これにより、本輻射式乾燥炉４は、各返り部８で方向転換された直後の気流が各集塵フィルタ９を通過して清浄化される構造になっている。また、図３に示すように、上記本対流式乾燥炉５は、乾燥炉幅方向（図３における紙面視左右方向）の一側（図３における紙面視右側）に乾燥炉内に開口された吸気ダクト１１が設けられると共に他側（図３における紙面視左側）に乾燥炉内に開口された吹出しダクト１２が設けられている。
【００２５】
そして、図４に示すように、吸気ダクト１１は開口部１１ａの奥に括れ部１１ｂが形成されている。これにより、本対流式乾燥炉５は、吸気ダクト１１の括れ部１１ｂを流れる気流がノズル効果により加速されて開口部１１ａにおける気圧が大気圧と比較して低くなり、乾燥炉内の空気が吸気ダクト１１へ円滑に導かれる構造になっている。また、本対流式乾燥炉５は、乾燥炉５の内壁面の上部を形成する天井１３が乾燥炉幅方向（図３における紙面視左右方向）両側に分割された各天井パネルにより形成され、各天井パネルは断面が弧状に形成されて天井全体でアーチ状に形成されている。また、各天井パネルは、各下端部が乾燥炉５の内壁面の側部にヒンジを介して接続され、該ヒンジの回りに回動可能な構造になっている。そして、本対流式乾燥炉５は、吸気ダクト１１から吸い込まれた乾燥炉内の空気が熱風供給装置１０により所定温度に昇温されて再び吹出しダクト１２から乾燥炉内へ吹出されている。
【００２６】
これにより、本対流式乾燥炉５は、吹出しダクト１２から吹出された空気がアーチ状に形成された天井１３に沿って流れて、乾燥炉内に図３における紙面視で反時計回り方向に循環する気流が形成される構造になっている。なお、本対流式乾燥炉５は、各天井パネルの内側面１３ａに弗素樹脂コーティング処理が施され、各天井パネルの内側面１３ａに付着するヤニ状の汚染物質が各天井パネルにこびりつくのが防止されている。また、図２及び図５に示すように、本乾燥炉３は、各乾燥炉４，５の底部に車体搬送方向（図２における紙面視左右方向）へ延びる流水パン１４が設置されている。そして、上記流水パン１４には、温水ボイラにより所定温度（本実施の形態では約６０℃）に昇温された水（温水）が所定流量（本実施の形態では毎分６リットル）で供給されている。
【００２７】
また、本乾燥炉３は、流水パン１４を流れる流水（温水）が、輻射式乾燥炉４の入口側から出口側へ向かう方向（図２における紙面視左方向）へ流下されると共に対流式乾燥炉５の出口側から入口側へ向かう方向（図２における紙面視右方向）へ流下されている。そして、本乾燥炉３は、各乾燥炉４，５の乾燥炉内を流下した後の温水が回収部１６で回収され、回収された温水が浄水装置で浄水処理されて水洗工程で再利用される構造になっている。また、図６に示すように、上記流水パン１４には底部１４ａに、アングル材で形成された突起１５が当該流水パン１４を流下する流水が流れる方向（図６における紙面視右方向）と直交する方向（図６における紙面視方向）に延設されると共に流水が流れる方向へ所定間隔で配置されている。
【００２８】
そして、本乾燥炉３は、流水パン１４を流下する流水（温水）が上記突起１５を通過して流水に酸素が取り込まれることで流水が活性化される。これにより、本乾燥炉３は、回収部１６で回収された汚濁水が浄水装置で水と汚染物質とに分離され易くなると共に水洗工程で再利用される水の洗浄能力が向上される構造になっている。なお、本乾燥炉３は、各乾燥炉４，５から回収される水の流量が確認（目視）することができるように構成されている。
【００２９】
次に、本実施の形態の作用を説明する。車体１の塗装ラインにおいては、車体１が搬送用ハンガ２（図１参照）で懸持された状態で、脱脂等の前処理が施された後に水洗処理される。そして、車体１は、水洗処理された後、電着塗装槽に浸漬されて電着塗装される。次に、電着塗装された車体１は、複数の水洗槽に順次浸漬されて付着した余分な電着液が洗い流された後、乾燥炉３の入口側に配置された本輻射式乾燥炉４の乾燥炉内へ搬送される。そして、図１に示すように、本輻射式乾燥炉４は、乾燥炉内の乾燥炉幅方向（図１における紙面視左右方向）中央に生じる上昇気流が乾燥炉幅方向両側へ分岐され、分岐された各気流が天井７の各天井パネルに設けられた各返り部８の各返り面８ａに沿って方向転換する。各返り部８により方向転換された各気流は各集塵フィルタ９を通過して乾燥用空気が清浄化される。
【００３０】
そして、本輻射式乾燥炉４は、清浄化された乾燥用空気（気流）が車体１（被乾燥物）の側部に沿って流れて車体１の下部に到達する。これにより、本輻射式乾燥炉４は、従来の乾燥炉において乾燥用空気（気流）を循環させるのが困難であった車体１の下部に乾燥用空気を循環させて車体１が均一に昇温される。さらに、本輻射式乾燥炉４は、車体１の下方に流水パン１４が設置され、該流水パン１４に所定温度（本実施の形態では６０℃）の温水が所定流量（本実施の形態では毎分６リットル）で流下されている。これにより、本輻射式乾燥炉４は、車体１の下部がより効果的に昇温されて車体１がより均一に（部位による温度斑がなく）昇温される。また、本輻射式乾燥炉４は、車体１から垂れ落とされた電着液等の汚染物質が流水パン１４を流下する流水により乾燥炉外へ搬出されて乾燥炉内がクリーンに保つことができる。そして、本輻射式乾燥炉４により適度（塗膜に塵埃が付着しない程度）に乾燥された車体１は、搬送用ハンガ２に懸持された状態で本輻射式乾燥炉４と連結された本対流式乾燥炉５の乾燥炉内へ搬送される。
【００３１】
そして、本対流式乾燥炉５は、吸気ダクト１１から吸い込まれた乾燥炉内の空気が熱風供給装置１０で所定温度に昇温されて吹出しダクト１２から再び乾燥炉内へ吹出される。これにより、本対流式乾燥炉５は、吹出しダクト１２から吹出された乾燥用空気（熱風）が天井１３のアーチ形状に沿って流れて、乾燥炉内に図３における紙面視で反時計回り方向へ循環する気流が形成される。これにより、本対流式乾燥炉５は、乾燥用空気が乾燥炉内を搬送される車体１の周囲を循環して車体１が均一に昇温される。さらに、本対流式乾燥炉５は、車体１の下方に流水パン１４が設置され、該流水パン１４に所定温度（本実施の形態では６０℃）の温水が所定流量（本実施の形態では毎分６リットル）で流下されている。これにより、本対流式乾燥炉５は、車体１の下部がより効果的に昇温されて車体１がより均一に（部位による温度斑がなく）昇温される。また、本対流式乾燥炉５は、天井１３から落下したヤニ状の汚染物質等が流水パン１４を流下する流水により乾燥炉外へ搬出されて乾燥炉内がクリーンに保たれる。
【００３２】
そして、車体１は、本対流式乾燥炉５の乾燥炉内を通過する過程で所定温度に昇温された状態が所定時間の間保持される。これにより、本対流式乾燥炉５は、車体１に塗装が均一（焼き斑がない状態）に焼き付けられる。一方、各乾燥炉４，５の流水パン１４を流下する流水（温水）は流水パン１４の底部１４ａに設置された突起１５を通過することで、酸素が取り込まれて活性化される。そして、活性化された温水は回収部１６で回収されて浄水装置で浄化処理された後、水洗工程で再利用される。また、本乾燥炉３は、各乾燥炉４，５の各天井７，１３を開いて各天井７，１３を清掃することで、作業が上を向いて行う清掃作業を廃止することができる。さらに、本乾燥炉３は、各天井７，１３の各内側面７ａ，１３ａに弗素樹脂コーティング処理が施されているため、各内側面７ａ，１３ａにヤニ状の汚染物質がこびりつくことがなく、各内側面７ａ，１３ａに付着したヤニ状の汚染物質を容易に取り除くことができる。
【００３３】
この実施の形態では以下の効果を奏する。
本乾燥炉３は、各乾燥炉４，５の天井７，１３がアーチ状に形成されたので、各乾燥炉内の不要な容量が省かれて熱効率が向上し、各乾燥炉４，５のランニングコストを低減させることができる。さらに、本乾燥炉３は、乾燥用空気がアーチ状に形成された各天井７，１３に沿って流れることで、各乾燥炉４，５の乾燥炉内に車体１の乾燥に向けて好適な気流を形成することが可能になる。
本乾燥炉３は、各乾燥炉４，５の各天井７，１３が開閉可能であるので、各天井４，５を開いて各天井７，１３の清掃を行うことにより、作業者が上を向いた状態での清掃作業を廃止して作業者への負担を軽減することができる。
本乾燥炉３は、各乾燥炉４，５の各天井７，１３の各内側面７ａ，１３ａに弗素樹脂コーティング処理が施されている。従って、本乾燥炉３は、各天井７，１３の各内側面７ａ，１３ａにヤニ状の汚染物質等が付着しにくくなり、また付着した場合であっても汚染物質等がこびりつくことがないので容易に取り除くことができ、乾燥炉４，５の清掃時間を大幅に短縮することができると共に乾燥炉４，５の清掃サイクルを延長することが可能になる。
本乾燥炉３は、各乾燥炉４，５の乾燥炉内に流水パン１４が設置され、該流水パン１４に所定温度（本実施の形態では６０℃）の温水が所定流量（本実施の形態では毎分６リットル）で流下されているので、他の部位と比較して昇温速度が小さい車体１の下部が効果的に昇温されて車体１をより均一に昇温させることが可能となる。従って、本乾燥炉３は、車体１に塗膜が均一に（焼き斑なく）焼き付けられて車体１の外観品質を確保することができる。
本乾燥炉３は、車体１から垂れ落ちた電着液や各乾燥炉４，５の天井７，１３から落下したヤニ状の汚染物質等が流水パン１４を流下する流水（温水）により乾燥炉外へ搬出される。従って、本乾燥炉３は、各乾燥炉４，５の各乾燥炉内がクリーンに保たれて清掃のサイクルタイムを延長させることができる。
本乾燥炉３は、流水パン１４の底部１４ａに突起１５が設けられたので、流水パン１４を流下する流水（温水）が突起１５を通過することで当該流水に酸素が取り込まれて流水が活性化される。従って、本乾燥炉３は、回収部１６で回収された汚濁水が浄水装置で水と汚濁物質とに分離し易くなり、浄水装置での浄水効率を向上させることができる。また、酸素が取り込まれて活性化された水（温水）を水洗工程で再利用することで、水洗工程で使用される水の洗浄能力を向上させることが可能となる。
本輻射式乾燥炉４は、天井７の各天井パネルの上端部に返り部８が設けられているので、各天井パネルに沿って各天井パネルの上端部から下端部へ向けて流れる気流（乾燥用空気）が各返り部８により方向が転換され、乾燥炉内に天井７の略中央から車体１の両側面を通過して車体１の下部へ向けて流れる気流が形成される。これにより、本輻射式乾燥炉４は、従来の乾燥炉において乾燥用空気（気流）を循環させるのが困難であった車体１の下部に乾燥用空気を循環させて車体１を均一に昇温させることが可能になる。従って、本輻射式乾燥炉４は、塗膜が車体１に均一に（焼き斑なく）焼き付けられて、車体の外観品質を向上させることができる。
本輻射式乾燥炉４は、天井７の各天井パネルに設けられた各返り部８の各返り面８ａの下流側端部に集塵フィルタ９が設けられたので、乾燥炉内を循環する全ての乾燥用空気が各集塵フィルタ９を通過して浄化される。従って、本輻射式乾燥炉４は、乾燥炉内を循環する乾燥用空気がクリーンに保たれて、塵埃が塗膜に付着するのを防いで車体１の外観品質を確保することができる。
本対流式乾燥炉５は、吸気ダクト１１に括れ部１１ｂが設けられたので、該括れ部１１ｂを流れる気流がノズル効果により加速されて開口部１１ａにおける気圧が大気圧と比較して低くなり、乾燥炉内の空気が吸気ダクト１１へ円滑に導かれる。従って、本対流式乾燥炉５は、吸気ダクト１１の吸気効率を向上させて乾燥炉内の乾燥用空気（気流）の循環効率を高めることができる。
【００３４】
なお、実施の形態は上記に限定されるものではなく、例えば次のように構成してもよい。
輻射式乾燥炉４は、返り部８の返り角度θを調節可能に構成してもよい。この場合、返り部８の返り角度θを車体形状に応じて調節することで、乾燥炉内に車体１を乾燥させるに向けて最適な気流を形成することが可能となる。
輻射式乾燥炉４に用いられる返り部８を対流式乾燥炉５に設けて構成してもよい。この場合、形成したい気流に応じて返り部８の数量、形状並びに設置位置を選定する。また、この場合においても、必要に応じて集塵フィルタ９を設けてもよい。
流水パン１４は、例えば輻射式乾燥炉４と対流式乾燥炉５とのいずれか一方のみに設けるだけでもよい。また、流水パン１４の形状並びに設置位置、及び水温、流水量等の諸事項は適宜選定すればよい。
【００３５】
【発明の効果】
以上詳述したように、本発明によれば、車体（被乾燥物）が均一に昇温されると共に乾燥炉内の清掃が容易な塗装乾燥炉を提供することができる。
【図面の簡単な説明】
【図１】本輻射式乾燥炉の説明図である。
【図２】本塗装乾燥炉の概略構成を示す全体図である。
【図３】本対流式乾燥炉の説明図である。
【図４】本対流式乾燥炉の説明図で、特に、吸気ダクトの形状を示すための斜視図である。
【図５】本塗装乾燥炉の説明図で、特に、対流式乾燥炉に設置された流水パンを流下する流水（温水）を示す図である。
【図６】図５におけるＡ−Ａ断面を示す図である。
【符号の説明】
１車体（被乾燥物）
３塗装乾燥炉
４輻射式乾燥炉（塗装乾燥炉）
５対流式乾燥炉（塗装乾燥炉）
７天井（輻射式乾燥炉側）
７ａ内側面（内壁面）
８返り部
９集塵フィルタ
１３天井（対流式乾燥炉側）
１３ａ内側面（内壁面）
１４流水パン
１４ａ底部（流水パン）
１５突起[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tunnel-type coating and drying furnace used for a coating line or the like of an automobile body.
[0002]
[Prior art]
Generally, a paint drying oven (hereinafter, simply referred to as a drying oven) incorporated in a coating line of an automobile is configured by combining a radiation drying oven and a convection drying oven. In the radiation drying furnace, a heat radiation duct is provided along both side walls in the drying furnace, and air heated by passing through a combustion device is introduced into the heat radiation duct. In the radiant drying furnace, the temperature inside the drying furnace is raised by radiant heat (radiant heat) of the heat radiation duct and maintained at a required temperature (a temperature suitable for drying the paint). Further, in the convection type drying furnace, an outlet duct is arranged on one side wall in the drying furnace and an intake duct is arranged on the other side wall, and the air sucked from the inlet duct is heated by a combustion device and dried from the outlet duct. It is blown into the furnace. The convection drying oven has higher thermal efficiency than the radiant drying oven, but because the air in the drying oven is circulated, if the coating film is in an uncured state, the painted surface (the exterior surface of the vehicle body) There is a possibility that dust in the air adheres to the vehicle and the appearance of the vehicle body becomes poor.
[0003]
Therefore, in the drying oven, a radiant drying oven having lower thermal efficiency than the convection drying oven but ensuring the appearance quality of the vehicle body is installed at the entrance side of the drying oven. A convection drying oven is installed at the outlet side of the drying oven, and a vehicle body having a coating film dried appropriately (to the extent that dust does not adhere to the painted surface) is carried into the convection drying oven. By the way, thermosetting paints, which are often used for painting automobiles, are cured by maintaining a predetermined temperature or higher for a predetermined time. Therefore, in the drying oven, it is necessary to uniformly raise the temperature of a vehicle body (painted surface) having a complicated shape to minimize the temperature difference between the parts. However, in the radiant drying oven, when comparing the fender panel, door panel, etc. facing the radiation duct with other parts, especially the roof, the hood panel, etc., there is a large difference in the rate of temperature rise, and the entire vehicle body is made uniform. It was difficult to raise the temperature.
[0004]
Therefore, Patent Document 1 discloses a drying furnace in which a ceiling is formed in an arch shape for the purpose of uniformly heating a vehicle body. When the ceiling is formed in an arch shape, the drying furnace can effectively circulate the air in the drying furnace toward drying by eliminating a wasteful volume in the drying furnace. However, the ceiling portion is disposed at a position relatively distant from the vehicle body because it is necessary to avoid interference with a hanger that carries the vehicle body on the painting line while suspending the vehicle body. As a result, in the conventional drying furnace, the rising airflow generated in the center of the drying furnace in the width direction of the drying furnace is lowered at a position away from the vehicle body along the vaulted ceiling, and the drying air is supplied to the lower side of the vehicle body. Parts could not be supplied effectively. In particular, conventional drying furnaces tend to have a lower heating rate at the lower surface of the rocker than other parts, and it is necessary to increase the heating rate at the lower part of the vehicle body to more uniformly heat the vehicle body. It is.
[0005]
Further, in the conventional drying furnace, since the inner wall surface is formed of a galvanized steel sheet, an organic solvent component or the like evaporated from the coating film adheres to the inner wall surface in a tan-like manner. And, if the tar-like contaminant adhered to the inner wall surface adheres to the painted surface, it may cause the appearance of the vehicle body to be poor. Therefore, it is necessary to periodically clean the inside of the drying furnace. However, since the tar-like contaminants are stuck to the inner wall surface of the drying furnace, cleaning them requires a great deal of time and effort, and increases the maintenance cost. Furthermore, since cleaning of the scum-like contaminants stuck on the ceiling is an upward operation, the burden on the operator has been greatly improved, and improvement has been demanded.
[0006]
[Patent Document 1]
Utility Model Registration No. 2501427 (page 18, left column, line 18 to page 4, left column, line 9, FIG. 2)
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coating and drying furnace in which the temperature of the vehicle body (the object to be dried) is uniformly increased and the inside of the drying furnace is easily cleaned.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 of the present invention is a tunnel type coating and drying furnace, wherein a cross section of a ceiling is formed in an arch shape, and an air flow circulating in the drying furnace on the ceiling. Is provided with a return portion for changing the direction.
[0009]
According to a second aspect of the present invention, in the first aspect of the present invention, the return portion is provided with a dust collection filter through which the airflow immediately after the direction is changed by the return portion passes.
[0010]
According to a third aspect of the present invention, in the first or second aspect, the inner wall surface is subjected to a fluorine resin coating treatment.
[0011]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the ceiling can be opened and closed.
[0012]
According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, a running water pan through which water having a predetermined temperature flows at a predetermined flow rate is provided below the object to be dried.
[0013]
According to a sixth aspect of the present invention, in the fifth aspect of the invention, a projection is provided on a bottom portion of the running water pan.
[0014]
In order to achieve the above object, an invention according to claim 7 of the present invention is a tunnel-type coating and drying furnace, in which a flowing water pan through which water at a predetermined temperature flows down at a predetermined flow rate below an object to be dried. It is characterized by being provided.
[0015]
Therefore, according to the first aspect of the present invention, the airflow circulating in the drying furnace is changed in direction by the return portion, and an airflow suitable for uniformly drying the object to be dried in the drying furnace can be formed.
[0016]
According to the second aspect of the present invention, the drying air in the drying furnace can be efficiently cleaned.
[0017]
According to the third aspect of the present invention, it is possible to easily remove the tar-like contaminants attached to the inner wall surface.
[0018]
According to the invention described in claim 4, cleaning can be performed with the ceiling open.
[0019]
According to the fifth aspect of the present invention, the contaminants dropped on the floor of the drying furnace are transported to the outside of the drying furnace by running water flowing down the running water pan, and the inside of the drying furnace is kept clean. Further, by flowing flowing water at a predetermined temperature into the flowing water pan at a predetermined flow rate, the temperature of the lower portion of the object to be dried is effectively increased, and the entire object to be dried is uniformly heated.
[0020]
In the invention described in claim 6, the running water is stirred by passing through the projections, and oxygen is taken into the running water to activate the running water. By collecting the activated running water and reusing it in the washing step, the washing effect of the washing water can be enhanced.
[0021]
According to the seventh aspect of the present invention, the contaminants dropped on the floor of the drying furnace are transported to the outside of the drying furnace by running water flowing down the running water pan, and the inside of the drying furnace is kept clean. Further, by flowing flowing water at a predetermined temperature into the flowing water pan at a predetermined flow rate, the temperature of the lower portion of the object to be dried is effectively increased, and the entire object to be dried is uniformly heated.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows a schematic configuration of the main coating and drying furnace 3 (hereinafter, simply referred to as the drying furnace 3). As shown in this figure, the present drying furnace 3 is provided with a radiation-type drying furnace 4 on the inlet side of the drying furnace 3 (on the right side in the drawing of FIG. 2) and the outlet side of the drying furnace 3 (FIG. 2). (On the left side in the drawing), the convection drying oven 5 is disposed. Then, the vehicle body 1 (the object to be dried) is conveyed in the drying furnaces 4 and 5 at a predetermined speed to the left as viewed in FIG. It is structured to be baked. As shown in FIG. 1, in the present radiation type drying furnace 4, heat radiation ducts 6 are arranged on both sides in the width direction of the drying furnace (the left-right direction as viewed in FIG. 1). A side portion is formed on the inner wall surface.
[0023]
As shown in FIG. 1, the radiant drying furnace 4 includes ceiling panels each having a ceiling 7 divided into both sides in a width direction of the drying furnace (a left-right direction as viewed in FIG. 1). Are formed in an arc shape and are formed in an arch shape over the entire ceiling. Each ceiling panel has a lower end connected to an upper portion of the heat radiation duct 6 via a hinge, and has a structure capable of rotating around the hinge. The radiant drying furnace 4 has a tan-like shape in which the inner surface 7a of each ceiling panel forming the upper part of the inner wall surface of the drying furnace 4 is coated with a fluorine resin, and adheres to the inner surface 7a of each ceiling panel. Contaminants are prevented from sticking to each ceiling panel. In addition, as shown in FIG. 2, hot air is supplied / discharged (circulated) to each heat radiation duct 6 by a hot air supply device 10. As shown in FIG. 1, the radiant drying furnace 4 has a substantially triangular cross-section extending at the upper end of the inner side surface 7 a of each ceiling panel of the ceiling 7 in the vehicle body transport direction (the direction as viewed in the drawing in FIG. 1). A return portion 8 formed in a shape is provided.
[0024]
Accordingly, the radiant drying furnace 4 is configured such that the airflow flowing from the center of the drying furnace in the width direction of the drying furnace (the left-right direction as viewed in FIG. 1) along the ceiling panels of the ceiling 7 toward the lower end of each ceiling panel. The return angle θ of the return portion 8 is set so that the direction is changed as shown in FIG. 1 and flows along the side surface of the vehicle body 1 to reach the lower part of the vehicle body 1. In the present embodiment, the return angle θ of the return portion 8 is set to 28 to 30 degrees. In the radiation drying furnace 4, a dust collecting filter 9 is provided at a downstream end of each return surface 8a of each return portion 8 provided on each ceiling panel of the ceiling 7. Thus, the radiant drying furnace 4 has a structure in which the airflow immediately after the direction change in each return portion 8 passes through each dust collection filter 9 and is cleaned. As shown in FIG. 3, the convection drying oven 5 is opened in the drying oven on one side (right side in FIG. 3) in the width direction of the drying oven (right and left direction in FIG. 3). An intake duct 11 is provided, and an outlet duct 12 opened in the drying furnace is provided on the other side (on the left side in FIG. 3 as viewed in the drawing).
[0025]
As shown in FIG. 4, the intake duct 11 has a constricted portion 11b formed at the back of the opening 11a. Thereby, in the convection type drying furnace 5, the airflow flowing through the constricted portion 11b of the intake duct 11 is accelerated by the nozzle effect, and the air pressure in the opening 11a becomes lower than the atmospheric pressure. It is structured to be smoothly guided to the duct 11. Further, the convection type drying furnace 5 is formed by respective ceiling panels in which a ceiling 13 forming an upper portion of an inner wall surface of the drying furnace 5 is divided into both sides in a width direction of the drying furnace (a left-right direction as viewed in FIG. 3). The ceiling panel has an arc-shaped cross section, and is formed in an arch shape over the entire ceiling. Each ceiling panel has a lower end connected to a side of the inner wall surface of the drying furnace 5 via a hinge, and has a structure rotatable around the hinge. Then, in the convection type drying furnace 5, the air in the drying furnace sucked from the intake duct 11 is heated to a predetermined temperature by the hot air supply device 10 and is blown out again from the blowing duct 12 into the drying furnace.
[0026]
Thereby, in the convection type drying furnace 5, the air blown out from the blowing duct 12 flows along the arched ceiling 13 and circulates in the drying furnace in a counterclockwise direction as viewed in the drawing in FIG. 3. It has a structure in which a flowing air flow is formed. The convection drying furnace 5 is provided with a fluorine resin coating treatment on the inner surface 13a of each ceiling panel, thereby preventing the dust-like contaminants adhering to the inner surface 13a of each ceiling panel from sticking to each ceiling panel. Have been. As shown in FIGS. 2 and 5, the drying oven 3 is provided with a running water pan 14 extending in the vehicle body transport direction (the left-right direction as viewed in FIG. 2) at the bottom of each of the drying ovens 4 and 5. Water (warm water) heated to a predetermined temperature (about 60 ° C. in the present embodiment) by the hot water boiler is supplied to the running water pan 14 at a predetermined flow rate (6 liters per minute in the present embodiment). ing.
[0027]
In the drying furnace 3, the flowing water (hot water) flowing through the flowing water pan 14 flows down from the inlet side to the outlet side of the radiant drying furnace 4 (to the left as viewed in FIG. 2) and the convection drying is performed. It flows down in the direction from the outlet side of the furnace 5 to the inlet side (to the right as viewed in FIG. 2). In the drying oven 3, the hot water flowing down in the drying ovens of the drying ovens 4 and 5 is collected by the collection unit 16, and the collected hot water is subjected to the water purification treatment by the water purification device and reused in the water washing process. The structure is As shown in FIG. 6, a projection 15 formed of an angle material is formed on the bottom portion 14a of the running water pan 14 at right angles to a direction in which flowing water flowing down the running water pan 14 flows (rightward in FIG. 6). And extending at predetermined intervals in the direction in which the flowing water flows.
[0028]
In the drying furnace 3, flowing water (hot water) flowing down the flowing water pan 14 passes through the protrusions 15, and oxygen is taken into the flowing water to activate the flowing water. Thereby, the present drying furnace 3 has a structure in which the polluted water collected by the collecting unit 16 is easily separated into water and contaminants by the water purification device, and the washing ability of the water reused in the washing step is improved. Has become. The drying furnace 3 is configured so that the flow rate of water recovered from each of the drying furnaces 4 and 5 can be checked (visually).
[0029]
Next, the operation of the present embodiment will be described. In the painting line of the vehicle body 1, in a state where the vehicle body 1 is suspended by the transport hanger 2 (see FIG. 1), a pre-treatment such as degreasing is performed and then a water washing process is performed. Then, after the vehicle body 1 is washed with water, it is immersed in an electrodeposition coating tank and subjected to electrodeposition coating. Next, the body 1 subjected to the electrodeposition coating is successively immersed in a plurality of washing tanks, and after the excess electrodeposition liquid attached thereto is washed away, the radiant drying furnace 4 disposed at the entrance side of the drying furnace 3 is used. Transported into the drying oven. As shown in FIG. 1, in the radiation drying furnace 4, an ascending airflow generated in the center of the drying furnace in the width direction of the drying furnace (the left-right direction as viewed in FIG. 1) is branched to both sides in the drying furnace width direction. Each of the generated airflows changes its direction along each return surface 8a of each return portion 8 provided on each ceiling panel of the ceiling 7. The respective airflows whose directions have been changed by the respective return portions 8 pass through the respective dust collection filters 9 to purify the drying air.
[0030]
In the radiant drying furnace 4, the purified drying air (air flow) flows along the side of the vehicle body 1 (the object to be dried) and reaches the lower part of the vehicle body 1. As a result, the radiant drying furnace 4 circulates the drying air in the lower part of the vehicle body 1 where it was difficult to circulate the drying air (air flow) in the conventional drying furnace, so that the vehicle body 1 is uniformly heated. Is done. Further, in the radiant drying furnace 4, a running water pan 14 is installed below the vehicle body 1, and hot water at a predetermined temperature (60 ° C. in the present embodiment) is supplied to the flowing water pan 14 at a predetermined flow rate (every time in the present embodiment). (6 liters per minute). As a result, in the radiation drying furnace 4, the temperature of the lower portion of the vehicle body 1 is more effectively raised, and the temperature of the vehicle body 1 is raised more uniformly (there is no temperature unevenness due to parts). Further, in the radiation drying furnace 4, contaminants such as electrodeposition liquid dropped from the vehicle body 1 are carried out of the drying furnace by running water flowing down the running water pan 14, and the inside of the drying furnace can be kept clean. . Then, the vehicle body 1 dried moderately (to the extent that dust does not adhere to the coating film) by the radiant drying furnace 4 is connected to the radiant drying furnace 4 while being suspended by the transport hanger 2. The convection type drying furnace 5 is conveyed into the drying furnace.
[0031]
Then, in the convection type drying furnace 5, the air in the drying furnace sucked from the intake duct 11 is heated to a predetermined temperature by the hot air supply device 10, and is blown out from the blowing duct 12 into the drying furnace again. Thereby, in the convection type drying furnace 5, the drying air (hot air) blown out from the blowing duct 12 flows along the arch shape of the ceiling 13, and flows into the drying furnace in a counterclockwise direction as viewed in a plane of FIG. 3. A circulating airflow is formed. Thereby, in the convection type drying furnace 5, the drying air circulates around the vehicle body 1 being conveyed in the drying furnace, so that the vehicle body 1 is uniformly heated. Further, in the convection type drying furnace 5, a running water pan 14 is provided below the vehicle body 1, and hot water at a predetermined temperature (60 ° C. in the present embodiment) is supplied to the running water pan 14 at a predetermined flow rate (every time in the present embodiment). (6 liters per minute). Thereby, in the convection type drying furnace 5, the temperature of the lower portion of the vehicle body 1 is more effectively raised, and the temperature of the vehicle body 1 is raised more uniformly (there is no temperature unevenness due to parts). Further, in the convection type drying furnace 5, tar-like contaminants falling from the ceiling 13 are carried out of the drying furnace by running water flowing down the running water pan 14, and the inside of the drying furnace is kept clean.
[0032]
Then, the state in which the vehicle body 1 has been heated to a predetermined temperature in the course of passing through the drying furnace of the convection drying furnace 5 is maintained for a predetermined time. Thereby, the convection type drying furnace 5 is baked on the vehicle body 1 so that the coating is uniform (without burning). On the other hand, flowing water (hot water) flowing down the flowing water pan 14 of each of the drying ovens 4 and 5 passes through the protrusion 15 provided on the bottom 14a of the flowing water pan 14, and is taken in and activated by oxygen. Then, the activated warm water is recovered by the recovery unit 16 and purified by the water purification device, and then reused in the water washing step. Further, in the drying oven 3, the ceilings 7, 13 of the drying ovens 4, 5 are opened and the ceilings 7, 13 are cleaned, so that the cleaning operation in which the operation is directed upward can be eliminated. Further, in the present drying furnace 3, since the inner surfaces 7a and 13a of the ceilings 7 and 13 are subjected to the fluororesin coating treatment, the inner surface 7a and 13a do not stick to the tar-like contaminants. The tar-like contaminants adhering to the inner side surfaces 7a and 13a can be easily removed.
[0033]
This embodiment has the following effects.
In the present drying furnace 3, since the ceilings 7, 13 of the drying furnaces 4, 5 are formed in an arch shape, unnecessary capacity in each of the drying furnaces is omitted, the thermal efficiency is improved, and the drying furnaces 4, 5 Running costs can be reduced. Further, the drying oven 3 is suitable for drying the vehicle body 1 in the drying ovens of the drying ovens 4 and 5 by allowing the drying air to flow along the ceilings 7 and 13 formed in an arch shape. An airflow can be formed.
Since the ceilings 7 and 13 of the drying furnaces 4 and 5 can be opened and closed in the main drying furnace 3, the ceilings 4 and 5 are opened to clean the ceilings 7 and 13, so that the worker can move upward. The cleaning work in the facing state is abolished, and the burden on the worker can be reduced.
In the present drying furnace 3, the inner surfaces 7a and 13a of the ceilings 7 and 13 of the drying furnaces 4 and 5 are coated with a fluorine resin. Accordingly, in the present drying furnace 3, the dust-like contaminants and the like hardly adhere to the inner side surfaces 7 a and 13 a of the ceilings 7 and 13, and even if they do, the contaminants and the like do not stick. The drying furnaces 4 and 5 can be easily removed, and the cleaning time of the drying furnaces 4 and 5 can be significantly reduced, and the cleaning cycle of the drying furnaces 4 and 5 can be extended.
In the present drying furnace 3, a flowing water pan 14 is installed in the drying furnace of each of the drying furnaces 4 and 5, and hot water at a predetermined temperature (60 ° C. in the present embodiment) is supplied to the flowing water pan 14 at a predetermined flow rate (this embodiment). (6 liters per minute), the lower part of the vehicle body 1, which has a lower heating rate than other parts, can be heated effectively, and the body 1 can be heated more uniformly. Become. Therefore, in the drying furnace 3, the coating film is uniformly baked (without burning) on the vehicle body 1, and the appearance quality of the vehicle body 1 can be secured.
The drying furnace 3 is a drying furnace which uses flowing water (warm water) in which the electrodeposition liquid dropped from the vehicle body 1 and the contaminant-like contaminants dropped from the ceilings 7 and 13 of the drying furnaces 4 and 5 flow down the flowing water pan 14. It is carried out. Therefore, in the drying furnace 3, the inside of each of the drying furnaces 4 and 5 is kept clean, and the cycle time of cleaning can be extended.
In the present drying furnace 3, the projections 15 are provided on the bottom portion 14 a of the flowing water pan 14. When the flowing water (hot water) flowing down the flowing water pan 14 passes through the projections 15, oxygen is taken into the flowing water to activate the flowing water. Be converted to Therefore, in the present drying furnace 3, the contaminated water collected by the collection unit 16 is easily separated into water and polluted substances by the water purification device, and the water purification efficiency in the water purification device can be improved. Further, by reusing the water (warm water) activated by the incorporation of oxygen in the washing step, it is possible to improve the washing ability of the water used in the washing step.
In the radiant drying furnace 4, since the return portion 8 is provided at the upper end of each ceiling panel of the ceiling 7, the airflow (drying) flowing from the upper end to the lower end of each ceiling panel along each ceiling panel. The direction of the air for use is changed by each return portion 8, and an airflow is formed in the drying oven, which flows from substantially the center of the ceiling 7 to the lower portion of the vehicle body 1 through the both sides of the vehicle body 1. As a result, the radiation drying furnace 4 circulates the drying air in the lower part of the vehicle body 1 where it was difficult to circulate the drying air (air flow) in the conventional drying furnace, thereby uniformly heating the vehicle body 1. It becomes possible to do. Therefore, in the radiation drying furnace 4, the coating film is baked uniformly (without burning) on the vehicle body 1, and the appearance quality of the vehicle body can be improved.
In the present radiation type drying furnace 4, since the dust collecting filter 9 is provided at the downstream end of each return surface 8 a of each return portion 8 provided on each ceiling panel of the ceiling 7, all of the circulating inside the drying furnace is performed. Drying air passes through each dust collecting filter 9 and is purified. Therefore, in the radiation type drying furnace 4, the drying air circulating in the drying furnace is kept clean, dust is prevented from adhering to the coating film, and the appearance quality of the vehicle body 1 can be secured.
In the convection type drying furnace 5, the constricted portion 11b is provided in the intake duct 11, so that the airflow flowing through the constricted portion 11b is accelerated by the nozzle effect, and the pressure in the opening 11a becomes lower than the atmospheric pressure, The air in the drying furnace is smoothly guided to the intake duct 11. Therefore, the convection type drying furnace 5 can improve the suction efficiency of the suction duct 11 and increase the circulation efficiency of the drying air (air flow) in the drying furnace.
[0034]
The embodiment is not limited to the above, and may be configured as follows, for example.
The radiation type drying furnace 4 may be configured so that the return angle θ of the return portion 8 can be adjusted. In this case, by adjusting the return angle θ of the return portion 8 according to the shape of the vehicle body, it is possible to form an optimal airflow for drying the vehicle body 1 in the drying furnace.
The return section 8 used in the radiation drying furnace 4 may be provided in the convection drying furnace 5. In this case, the number, shape, and installation position of the return portions 8 are selected according to the airflow to be formed. Also in this case, a dust collection filter 9 may be provided as needed.
The flowing water pan 14 may be provided only in one of the radiation drying furnace 4 and the convection drying furnace 5, for example. In addition, the shape and installation position of the running water pan 14 and various items such as water temperature and flowing water amount may be appropriately selected.
[0035]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a coating and drying furnace in which the temperature of the vehicle body (the object to be dried) is uniformly increased and the inside of the drying furnace is easily cleaned.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of the present radiation drying furnace.
FIG. 2 is an overall view showing a schematic configuration of the present coating and drying furnace.
FIG. 3 is an explanatory diagram of the convection type drying furnace.
FIG. 4 is an explanatory view of the convection-type drying furnace, particularly a perspective view showing a shape of an intake duct.
FIG. 5 is an explanatory view of the present coating and drying furnace, particularly showing flowing water (hot water) flowing down a flowing water pan installed in a convection type drying furnace.
FIG. 6 is a diagram showing a cross section taken along line AA in FIG. 5;
[Explanation of symbols]
1 body (dry matter)
3 Paint drying oven 4 Radiation drying oven (paint drying oven)
5 Convection type drying oven (paint drying oven)
7 Ceiling (radiant drying furnace side)
7a Inner surface (inner wall)
8 Return part 9 Dust collection filter 13 Ceiling (convection type drying furnace side)
13a Inner surface (inner wall)
14 Running water pan 14a Bottom (running water pan)
15 protrusion

Claims

A tunnel type coating / drying furnace, wherein a cross section of a ceiling is formed in an arch shape, and a return portion for changing a direction of an airflow circulating in the drying furnace is provided on the ceiling.

The paint drying oven according to claim 1, wherein the return portion is provided with a dust collection filter through which an airflow immediately after the direction of the return portion is changed.

The coating and drying furnace according to claim 1 or 2, wherein the inner wall surface is subjected to a fluorine resin coating treatment.

The coating and drying furnace according to any one of claims 1 to 3, wherein the ceiling is openable and closable.

The coating and drying oven according to any one of claims 1 to 4, wherein a flowing water pan through which water at a predetermined temperature flows down at a predetermined flow rate is provided below the object to be dried.

The coating and drying furnace according to claim 5, wherein a projection is provided on a bottom of the running water pan.

What is claimed is: 1. A coating / drying furnace of a tunnel type, wherein a flowing water pan through which water at a predetermined temperature flows down at a predetermined flow rate is provided below an object to be dried.