JP3911822B2

JP3911822B2 - Manufacturing method of heat exchanger

Info

Publication number: JP3911822B2
Application number: JP04582498A
Authority: JP
Inventors: 幹夫福岡; 貢中村
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1998-02-26
Filing date: 1998-02-26
Publication date: 2007-05-09
Anticipated expiration: 2018-02-26
Also published as: JPH11245023A

Description

【０００１】
【発明の属する技術分野】
本発明はろう付けにより製造される熱交換器において、ろう付け前にコア部内に所定の大きさを持った保形部材（治具）を配置して、空間部を形成する製造方法に関する。
【０００２】
【従来の技術】
本発明者らは、車両エンジン（内燃機関）にて加熱された温水（エンジン冷却水）を熱源として空気を加熱する車両暖房用熱交換器において、温水温度の低温時における暖房熱源不足の解消のために、熱交換用コア部内に電気発熱体を一体化して、電気発熱体により空気を加熱するようにしたものを開発中であり、例えば、特願平９−２１１９５４号の特許出願にて「電気発熱体を一体化した暖房用熱交換器」を提案している。
【０００３】
この先願においては、図８〜１０に示すように、温水が流通する偏平チューブ６を多数本並列配置するとともに、この多数本の偏平チューブ６の間にコルゲートフィン７を接合することにより熱交換用コア部３が構成される暖房用熱交換器において、熱交換用コア部３の一部の部位に電気発熱体ユニット９設置用の所定間隔の空間部を設定して、熱交換用コア部３をろう付けにより組付けた後に、前記一部の部位に電気発熱体ユニット９を設置している。
【０００４】
この電気発熱体ユニット９は発熱体素子９０ａを包含する発熱体本体部９０を備え、この発熱体本体部９０をコルゲートフィン９１、９２を介して枠体９３、９４の内側に一体保持する構成となっている。
これによると、熱交換用コア部３の組付後（一体ろう付け終了後）に電気発熱体ユニット９を設置できるから、熱交換用コア部３のろう付けによって発熱体素子９０ａの電気的特性を損なう恐れがない。しかも、電気発熱体ユニット９は予め、枠体９３、９４の内側に発熱体本体部９０とコルゲートフィン９１、９２とを一体保持した１ユニットとして構成しており、かつ熱交換用コア部３がコルゲートフィンタイプであるから、電気発熱体ユニット９の厚さに相当する分の偏平チューブ６とコルゲートフィン７を除去するだけで、電気発熱体ユニット９を熱交換用コア部３に対して簡単に組付できる等の特徴を持っている。
【０００５】
ところで、偏平チューブ６とコルゲートフィン７との組合せで構成される熱交換用コア部３の一部の部位に所定間隔の空間部を設定する製造方法としては、従来、特公平６−７７８２７号公報において提案されているものがあり、この従来方法によると、図１１に示すように、保形部材１１が全面的に両隣の偏平チューブ６、６の偏平面に密着するように配置されている。
【０００６】
【発明が解決しようとする課題】
このため、保形部材１１の存在により偏平チューブ６へのフラックス塗布が妨げられ、偏平チューブ接合部６ｃのろう付け性を悪化させるという不具合が生じることが判明した。
すなわち、熱交換器の各部を一体ろう付けにより組み立てる場合に、ろう付け性の確保のために、熱交換器の組み立て体に噴射器１２からフラックスを噴射して、熱交換器の各部品を構成するアルミニウム部材表面にフラックスを塗布する。このフラックスは熱交換器のアルミニウム部材表面の酸化皮膜の除去、再酸化の防止作用を果して、アルミニウム部材のろう付け性を向上するものである。
【０００７】
しかるに、上記の従来方法によると、保形部材１１が全面的に偏平チューブ６の偏平面に密着するので、保形部材１１と接するチューブ偏平面へのフラックス塗布が阻害される。その結果、図１１において、偏平チューブ６の中央接合部６ｃのろう付け不良が発生して、偏平チューブ６からの流体洩れ（例えば、暖房用温水の洩れ）を引き起こす原因になることが判明した。
【０００８】
本発明は上記点に鑑みてなされたもので、ろう付け前にコア部内に所定の大きさを持った保形部材を配置して、空間部を形成する製造方法において、保形部材によるろう付け性の悪化を解消することを目的とする。
【０００９】
【課題を解決するための手段】
上記目的を達成するため、請求項１記載の発明では、保形部材（１１）のうち、偏平チューブ（６）に接する面を、偏平チューブ（６）の長手方向と直交する方向に延びる凸面（１１ａ）と凹面（１１ｂ）とを有する凹凸面となし、凸面（１１ａ）の部分で保形部材（１１）が偏平チューブ（６）の面と接するようにしたことを特徴としている。
【００１０】
これによると、保形部材（１１）が全面的に偏平チューブ（６）の面と接することがなくなり、保形部材（１１）の凹面（１１ｂ）の部分はフラックスの浸透経路となるので、凹面（１１ｂ）部を通ってフラックスを偏平チューブ（６）の接合部（６ｃ）に十分塗布することができる。
その結果、ろう付け前にコア部（３）内に所定の大きさを持った保形部材（１１）を配置して空間部を形成する熱交換器においても、保形部材（１１）に阻害されることなく、偏平チューブ（６）へのフラックス塗布を十分行って、偏平チューブ（６）の接合部（６ｃ）のろう付けを良好に行うことができる。
【００１１】
本発明は、具体的には、請求項２記載のように、保形部材（１１）を取り出した後に形成される空間部に電気発熱体ユニット（９）を組付ける熱交換器において良好に実施できる。
また、請求項３記載の発明のように、凸面（１１ａ）と凹面（１１ｂ）を偏平チューブ（６）の長手方向と直交する方向に対して所定角度（θ）傾斜させれば、偏平チューブ（６）の長手方向において、隣接する凸面（１１ａ）相互のラップ部分（１１ｃ）を形成でき、偏平チューブ（６）の厚さ寸法の管理を良好に行うことができ、偏平チューブ（６）の厚さ寸法のばらつきを解消できる。
【００１２】
また、請求項４記載の発明のように、凸面（１１ａ）の途中に凸面（１１ａ）を分断する溝部（１１ｅ）を形成すれば、この溝部（１１ｅ）を通して偏平チューブ（６）へのフラックス塗布をより一層良好に行うことができる。
なお、上記各手段の括弧内の符号は、後述する実施形態記載の具体的手段との対応関係を示すものである。
【００１３】
【発明の実施の形態】
以下、本発明の実施形態を図に基づいて説明する。
（第１実施形態）
最初に、本発明方法により製造された車両暖房用熱交換器の全体構成を前述の図８〜１０に基づいて説明する。この熱交換器は、温水入口側タンク１と、温水出口側タンク２と、この両タンク１、２の間に設けられた熱交換用コア部３とを有している。
【００１４】
温水入口側タンク１には図示しない車両エンジンからの温水（エンジン冷却水）が流入する入口パイプ４が設けられ、温水出口側タンク２には温水を外部へ流出させ、エンジン側に還流させる出口パイプ５が設けられている。なお、本例の熱交換器は図８に示すように上下対称形であるので、温水入口側タンク１と温水出口側タンク２とを上下逆転してもよい。
【００１５】
各タンク１、２はそれぞれタンク本体部１ａ、２ａと、このタンク本体部１ａ、２ａの開口端面を閉じるシートメタル１ｂ、２ｂとからなり、図８の左右方向が長手方向となる周知のタンク構造である。そして、シートメタル１ｂ、２ｂには偏平状のチューブ挿入穴（図示せず）が多数個、図８の左右方向に１列または複数列並んで形成されている。
【００１６】
熱交換用コア部３は暖房用空気の流れ方向（図８の矢印Ａ方向）に対して平行な偏平状に形成された偏平チューブ６を多数個図８の左右方向に並列配置している。そして、この多数個の偏平チューブ６相互の間に波形状に成形されたコルゲートフィン（フィン部材）７を配置し接合している。このコルゲートフィン７には周知のごとく暖房用空気の流れ方向に対して所定角度で斜めに多数のルーバ７ａ（図１等参照）が切り起こし成形されており、このルーバ７ａの成形によりフィン熱伝達率を向上させている。
【００１７】
偏平チューブ６の両端開口部はシートメタル１ｂ、２ｂのチューブ挿入穴内にそれぞれ挿入され、接合される。また、コア部３の最外側（図８の左右両端部）のコルゲートフィン７のさらに外側にはサイドプレート８ａ、８ｂが配設され、このサイドプレート８ａ、８ｂは最外側のコルゲートフィン７およびシートメタル１ｂ、２ｂに接合される。
【００１８】
なお、本例における熱交換器では、上記各構成部品１〜８ｂのすべてがアルミニュウム（アルミニュウム合金も含む）にて成形され、ろう付けにて各部が一体に接合されて組付られる。
さらに、熱交換用コア部３の一部の部位に電気発熱体ユニット９を設置しており、より具体的には、図８の例では、熱交換用コア部３の４箇所に電気発熱体ユニット９を等間隔で設置している。この電気発熱体ユニット９の設置のために、熱交換用コア部３の所定部位において、１本の偏平チューブ６とこの偏平チューブ６の両側に接合されるコルゲートフィン７を除去して設定される所定間隔の空間部を形成しておき、この状態で、熱交換器をろう付けした後に、熱交換用コア部３内の上記偏平チューブ６およびコルゲートフィン７の除去部位に電気発熱体ユニット９を挿入している。
【００１９】
従って、電気発熱体ユニット９の厚さｔ₀（図９）は上記１本の偏平チューブ６とその両側のコルゲートフィン７とを合わせた厚さと同等に設定され、かつ長さＬはシートメタル１ｂ、２ｂ間の寸法と同等に設定されている。
図９、図１０はフィン付き電気発熱体ユニット９の具体的構造を例示するもので、電気発熱体ユニット９は、大別して発熱体本体部９０と、コルゲートフィン（フィン部材）９１、９２と、枠体９３、９４とから構成されている。まず、発熱体本体部９０は、図１０に示す構造になっており、板状の発熱体素子９０ａと、この発熱体素子９０ａの表裏両面に配置された細長の平板状の電極板９０ｂ、９０ｃとからなる３層のサンドウイッチ構造になっている。
【００２０】
そして、この電極板９０ｂ、９０ｃの周囲を全周にわたって電気的絶縁材料からなる被覆部材９０ｄにより被覆している。ここで、発熱体素子９０ａは所定の設定温度Ｔ₀（例えば、１５０°Ｃ付近）にて抵抗値が急増する正の抵抗温度特性を有する抵抗体材料（例えば、チタン酸バリウム）からなるＰＴＣヒータ素子である。発熱体素子９０ａの両電極板９０ｂ、９０ｃはアルミニュウム、銅、ステンレス等の導電金属材から成形されている。発熱体素子９０ａと両電極板９０ｂ、９０ｃは互いに圧接することにより、両者間の電気的導通を得る。
【００２１】
発熱体本体部９０はその被覆部材９０ｄが両側のコルゲートフィン９１、９２の波状の折り曲げ頂部に圧接するようにして、２つの枠体９３、９４内に組付られる。被覆部材９０ｄの具体的材質としては、高耐熱性の樹脂（例えば、ポリイミド樹脂等）が好ましい。上記電極板９０ｂは正極側電極板であり、また、上記電極板９０ｃは負極側電極板であり、それぞれ外部回路との電気接続用の端子部９０ｅ、９０ｆが一体成形されている。なお、端子部９０ｅ、９０ｆには、図示しない外部制御回路が電気接続され、この外部制御回路を介して車載電源から各電気発熱体ユニット９に通電されるようになっている。
【００２２】
次に、コルゲートフィン９１、９２は、熱交換用コア部３のコルゲートフィン７と同様の波形状のもので、アルミニウム等の熱伝導性に優れた金属からなる。また、枠体９３、９４はアルミニウム、ステンレス等の熱伝導性に優れた金属でコ字状に成形されており、枠体９３、９４にはその長手方向の両側面（空気流れ方向Ａ前後の両側面）の途中にそれぞれ、複数（本例では２個）の取付片９３ａ、９４ａが曲げ成形されている。
【００２３】
そして、この取付片９３ａ、９４ａの先端部を互いに重ね合わせて、この重ね合わせ部を溶接、ろう付け等の手段で接合することにより、２つの枠体９３、９４を一体に結合するとともに、２つの枠体９３、９４の間で発熱体本体部９０と、コルゲートフィン９１、９２に対して押圧力を作用させて、枠体９３、９４の内側空間に発熱体本体部９０と、コルゲートフィン９１、９２を保持する。
【００２４】
１０はステンレスのような耐食性に優れた金属材料からなる締結（バンド）部材であって、熱交換用コア部３の空気入口側の面および空気出口側の面の両方に配置される。締結部材１０はその両端に折り曲げ形状からなる引掛け部を有しており、この引掛け部を上下のサイドプレート８ａ、８ｂの長手方向の中央部に形成された係止溝部８ｃ、８ｄに引掛けて、上下のサイドプレート８ａ、８ｂの間に装着する。
【００２５】
この締結部材１０の装着により、熱交換用コア部３に対して圧縮方向の締付け力が作用するので、電気発熱体ユニット９を隣接する２個の偏平チューブ６、６の間に圧接保持させる締付け力を得ることができる。なお、図８では締結部材１０を熱交換用コア部３の上下方向の中央の１箇所のみに配置しているが、上下方向の複数箇所に締結部材１０を配置してもよい。
【００２６】
次に、上記した暖房用熱交換器の製造方法を説明すると、まず、最初に熱交換器構成を組み付けるコア組付工程を行う。すなわち、図１に示すように、熱交換用コア部３の偏平チューブ６とコルゲートフィン７を交互に積層するとともに、熱交換用コア部３のうち、電気発熱体ユニット９が設置される部位（図８の４箇所の斜線部）では、隣接する２本の偏平チューブ６、６の間に所定間隔Ｋを保持するために、この２本の偏平チューブ６、６の間に、所定間隔Ｋと同一の幅寸法を有する保形部材（治具）１１を挿入する。
【００２７】
この保形部材１１は後述の一体ろう付けの工程に対する耐熱性を有し、かつアルミニュウムろう付けされない特性を持った材質（例えば、カーボン等）で形成しておく。また、保形部材１１のうち、偏平チューブ６、６の偏平面と接する面には、図２に示すように、偏平チューブ６、６の長手方向（図１の上下方向）と直交する方向（換言すると空気流れ方向Ａ）に延びる凹凸面を形成している。従って、保形部材１１には、偏平チューブ６、６の偏平面と接する凸面１１ａと、偏平チューブ６、６の偏平面と接しない凹面１１ｂが交互に多数形成されている。なお、保形部材１１の長手方向寸法は、コア部３内への組み込み作業を容易化するため、偏平チューブ６、６の長手方向寸法より若干短くしてある。
【００２８】
上記のコア組付工程において、タンク１、２、パイプ４、５、およびサイドプレート８ａ、８ｂも組み付けて、図８に示す熱交換器全体構成の組付を行うことはもちろんである。
次に、上記のごとくして、組み付けた熱交換器組付体の組付状態を図示しない適宜の治具により保持する。
【００２９】
次に、熱交換器組付体の外面にフラックス噴射器（ノズル）１２からフラックスを吹きつけて、フラックスを熱交換器組付体の各アルミニウム部材の表面に塗布する。ここで、保形部材１１のうち、偏平チューブ６、６の偏平面と接する面には、偏平チューブ６、６の長手方向（図１の上下方向）と直交する方向（換言すると空気流れ方向Ａ）に延びる凹凸面を形成しており、そして、保形部材１１の凹面１１ｂはフラックス噴射器１２からのフラックス噴霧方向と平行になっているから、保形部材１１の左右両隣の偏平チューブ６、６においても凹面１１ｂを通って、フラックスが偏平チューブ６、６の偏平面の中央部に位置する接合部６ｃまで浸透することができ、この接合部６ｃ付近にも十分フラックスを塗布できる。
【００３０】
ここで、偏平チューブ６の具体的構成について説明すると、偏平チューブ６は、アルミニウム芯材（例えば：Ａ３０００系）の両面あるいは片面にろう材（例えば：Ａ４０００系）をクラッドした薄板状のアルミニウムクラッド材を用い、このアルミニウムクラッド材を図１に示すように巻き締め加工して、２つの偏平状の温水通路６ａ、６ｂを独立に構成するとともに、この２つの偏平状の温水通路６ａ、６ｂの中間に接合部６ｃを配置している。この接合部６ｃは、後述の熱交換器全体の一体ろう付けと同時にろう付けされるものである。
【００３１】
なお、コルゲートフィン７はろう材をクラッドしてないアルミニウムベア材（例えば：Ａ３０００系）からなる。また、上記フラックスとしては、非腐食性のフッ化物系フラックス（ＫＦ・ＡｌＦ₃等）が好適である。
上記のフラックス塗布工程を終了した後に、熱交換器組付体を治具により保持したまま、ろう付け炉内に搬入し、ろう付け工程を行う。すなわち、ろう付け炉内は窒素ガスまたは不活性ガス雰囲気に保持されており、この雰囲気にて熱交換器組付体をろう付け温度（６００°Ｃ程度）に加熱して、熱交換器各部材のアルミニウムクラッド材のろう材を溶融し、熱交換器組付体の各部材間を一体ろう付けする。このろう付け工程の時間は数分程度である。
【００３２】
このろう付け工程において、保形部材１１の両隣の偏平チューブ６、６では、その偏平面に保形部材１１が当接しているが、前述のごとく保形部材１１の凹面１１ｂを通して偏平チューブ６、６の接合部６ｃ付近にも十分フラックスを塗布しているので、偏平チューブ６、６の接合部６ｃのろう付け性を良好に維持できる。
【００３３】
また、保形部材１１と偏平チューブ６、６とが凸面１１ａのみで接触しており、両者間の接触面積を小さくしているから、ろう付け時に、熱容量の大きい保形部材１１の影響を受けて、両隣の偏平チューブ６、６の昇温速度が他の部位の偏平チューブ６に比して小さくなることを抑制でき、このことも、両隣の偏平チューブ６、６のろう付け性確保に貢献できる。
【００３４】
上記のろう付け工程の終了後に、熱交換器組付体をろう付け炉から搬出し、常温まで熱交換器組付体の温度が低下した後に、電気発熱体ユニット９の組付工程を行う。
電気発熱体ユニット９はそれ単独で、熱交換器組付体とは別に組付を行って、図９の構造を完成しておく。そして、熱交換器組付体の熱交換用コア部３における２本の偏平チューブ６、６の間に挿入されている４箇所の保形部材１１を取り出し、２本の偏平チューブ６、６の間に形成される所定間隔Ｋの空間部に、電気発熱体ユニット９を２つの枠体９３、９４の外側面が偏平チューブ面に接触するようにして組み付ける。この組付の後に、締結部材１０の両端の引掛け部を上下のサイドプレート８ａ、８ｂの係止溝部８ｃ、８ｄに引掛けて、上下のサイドプレート８ａ、８ｂの間に締結部材１０を熱交換用コア部３が圧縮されるように装着する。
【００３５】
これにより、電気発熱体ユニット９を２本の偏平チューブ６、６の間に圧接保持させる締付け力を熱交換用コア部３に対して作用させ、電気発熱体ユニット９を２本の偏平チューブ６、６の間に確実に保持固定できる。
（第２実施形態）
図３は第２実施形態による保形部材１１であり、凸面１１ａおよび凹面１１ｂを右下がりの所定角度θで傾斜させている。この傾斜角度θにより上段の凸面１１ａと下段の凸面１１ａとの間にラップ部分１１ｃが形成される。
【００３６】
第１実施形態の保形部材１１によると、偏平チューブ６、６の長手方向に沿って凸面１１ａによる押圧面と凹面１１ｂによる非押圧面とが交互に形成され、凹面１１ｂによる非押圧面の部分では偏平チューブ６、６の偏平面に押圧力が作用せず、偏平チューブ６、６の厚さ管理がしにくくなる。
これに対し、第２実施形態の保形部材１１によると、上記凸面１１ａのラップ部分１１ｃの存在により、偏平チューブ６、６の長手方向に沿って凸面１１ａによる押圧面が断続されることなく連続的に形成されるので、偏平チューブ６、６の厚さを良好に管理でき、偏平チューブ６、６の厚さのばらつきを解消することができる。
【００３７】
（第３実施形態）
図４は第３実施形態による保形部材１１であり、中央部に中空部１１ｄを有する形状としている。この中空部１１ｄの形成により、保形部材１１全体の質量が減少し、その分だけ保形部材１１の熱容量を減少できる。その結果、ろう付け時に、保形部材１１の昇温速度を高めることができるので、保形部材１１の存在による両隣の偏平チューブ６、６の昇温速度が低下することをより一層良好に抑制できる。
【００３８】
（第４実施形態）
図５は第４実施形態による保形部材１１であり、第１実施形態による凸面１１ａの形状（図２）に対して、凸面１１ａの中央部を分断する溝部１１ｅを追加したものである。この溝部１１ｅの追加により、偏平チューブ６、６の中央部の接合部６ｃへのフラックス塗布をより一層良好にすることができる。
【００３９】
（第５実施形態）
図６は第５実施形態による保形部材１１であり、凸面１１ａの形状を矩形状から断面三角状に尖っている楔形にした例である。
（第６実施形態）
図７は第６実施形態による保形部材１１であり、凸面１１ａの形状を矩形状から断面円弧状に成形された曲面形状（Ｒ形状）にした例である。
【００４０】
（他の実施形態）
なお、上記の実施形態では、車両暖房用熱交換器に方発明方法を適用する場合について説明したが、本発明方法は車両暖房用に限定されることなく、種々な用途の熱交換器に広く適用可能であり、また、所定間隔Ｋの空間部に、電気発熱体ユニット９を挿入する場合について説明したが、電気発熱体ユニット９以外の機器を挿入する場合にも本発明方法は適用可能である。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示す暖房用熱交換器組付状態の要部斜視図である。
【図２】図１の保形部材の斜視図である。
【図３】本発明の第２実施形態の保形部材の側面図である。
【図４】本発明の第３実施形態を示す暖房用熱交換器組付状態の要部斜視図である。
【図５】本発明の第４実施形態の保形部材の側面図である。
【図６】本発明の第５実施形態を示す暖房用熱交換器組付状態の要部斜視図である。
【図７】本発明の第６実施形態を示す暖房用熱交換器組付状態の要部斜視図である。
【図８】先願による暖房用熱交換器全体の斜視図である。
【図９】図８の暖房用熱交換器における電気発熱体ユニットの斜視図である。
【図１０】（ａ）は同電気発熱体ユニットの発熱体本体部の一部破断斜視図、（ｂ）は同発熱体本体部の横断面図、（ｃ）は同発熱体本体部の縦断面図、（ｄ）は同発熱体本体部の平面図である。
【図１１】従来方法による暖房用熱交換器組付状態の要部斜視図である。
【符号の説明】
１、２…タンク、３…熱交換用コア部、６…偏平チューブ、６ｃ…接合部、
７…コルゲートフィン、９…電気発熱体ユニット、１０…締結部材、
１１…保形部材、１１ａ…凸面、１１ｂ…凹面、１１ｃ…ラップ部分、
１１ｄ…中空部、１１ｅ…溝部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method for forming a space portion by arranging a shape-retaining member (jig) having a predetermined size in a core portion before brazing in a heat exchanger manufactured by brazing.
[0002]
[Prior art]
In the heat exchanger for heating a vehicle that heats air using hot water (engine cooling water) heated by a vehicle engine (internal combustion engine) as a heat source, the present inventors have solved the shortage of the heating heat source when the temperature of the hot water is low. Therefore, an electric heating element is integrated into the heat exchanging core and air is heated by the electric heating element. For example, in the patent application of Japanese Patent Application No. 9-211954, “ A heat exchanger for heating that integrates an electric heating element is proposed.
[0003]
In this prior application, as shown in FIGS. 8 to 10, a large number of flat tubes 6 through which hot water flows are arranged in parallel, and corrugated fins 7 are joined between the multiple flat tubes 6 for heat exchange. In the heating heat exchanger in which the core part 3 is configured, a space part with a predetermined interval for installing the electric heating element unit 9 is set in a part of the heat exchange core part 3, and the heat exchange core part 3 After being assembled by brazing, the electric heating element unit 9 is installed in the part of the part.
[0004]
The electric heating element unit 9 includes a heating element main body 90 including a heating element 90a, and the heating element main body 90 is integrally held inside the frames 93 and 94 via corrugated fins 91 and 92. It has become.
According to this, since the electric heating element unit 9 can be installed after the heat exchange core part 3 is assembled (after completion of the integral brazing), the electric characteristics of the heating element 90a are obtained by brazing the heat exchange core part 3. There is no fear of damage. Moreover, the electric heating element unit 9 is configured in advance as one unit in which the heating element main body 90 and the corrugated fins 91 and 92 are integrally held inside the frames 93 and 94, and the heat exchanging core 3 is provided. Since it is a corrugated fin type, simply removing the flat tube 6 and the corrugated fin 7 corresponding to the thickness of the electric heating element unit 9 makes it possible to easily connect the electric heating element unit 9 to the heat exchanging core 3. It has the characteristics that it can be assembled.
[0005]
By the way, as a manufacturing method for setting a space portion at a predetermined interval in a part of the heat exchange core portion 3 constituted by a combination of the flat tube 6 and the corrugated fins 7, Japanese Patent Publication No. 6-77827 has been known. In this conventional method, as shown in FIG. 11, the shape-retaining member 11 is disposed so as to be in close contact with the flat surfaces of the adjacent flat tubes 6 and 6 on both sides.
[0006]
[Problems to be solved by the invention]
For this reason, it has been found that the presence of the shape-retaining member 11 hinders the flux application to the flat tube 6 and causes a problem that the brazing property of the flat tube joint 6c is deteriorated.
That is, when assembling each part of the heat exchanger by integral brazing, in order to ensure brazability, the flux is injected from the injector 12 to the assembly of the heat exchanger to constitute each part of the heat exchanger. A flux is applied to the surface of the aluminum member. This flux removes the oxide film on the surface of the aluminum member of the heat exchanger and prevents reoxidation, thereby improving the brazing property of the aluminum member.
[0007]
However, according to the above-described conventional method, the shape-retaining member 11 is in close contact with the flat surface of the flat tube 6, so that flux application to the tube flat surface in contact with the shape-retaining member 11 is hindered. As a result, it has been found in FIG. 11 that a poor brazing of the central joint portion 6c of the flat tube 6 occurs and causes fluid leakage from the flat tube 6 (for example, leakage of warm water for heating).
[0008]
The present invention has been made in view of the above points. In a manufacturing method in which a shape-retaining member having a predetermined size is arranged in a core portion before brazing to form a space portion, the shape-retaining member is brazed. The purpose is to eliminate the deterioration of sex.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the surface of the shape-retaining member (11) in contact with the flat tube (6) is a convex surface extending in a direction perpendicular to the longitudinal direction of the flat tube (6). 11a) and a concave and convex surface having a concave surface (11b), and the shape retaining member (11) is in contact with the surface of the flat tube (6) at the convex surface (11a).
[0010]
According to this, since the shape-retaining member (11) does not entirely contact the surface of the flat tube (6) and the concave surface (11b) portion of the shape-retaining member (11) serves as a flux permeation path, The flux can be sufficiently applied to the joint portion (6c) of the flat tube (6) through the portion (11b).
As a result, even in the heat exchanger in which the shape retaining member (11) having a predetermined size is disposed in the core portion (3) before brazing to form a space portion, the shape retaining member (11) is obstructed. However, it is possible to satisfactorily braze the joint portion (6c) of the flat tube (6) by sufficiently applying the flux to the flat tube (6).
[0011]
Specifically, the present invention is preferably carried out in a heat exchanger in which the electric heating element unit (9) is assembled in the space formed after the shape-retaining member (11) is taken out. it can.
Moreover, if the convex surface (11a) and the concave surface (11b) are inclined at a predetermined angle (θ) with respect to the direction orthogonal to the longitudinal direction of the flat tube (6) as in the invention described in claim 3, the flat tube ( In the longitudinal direction of 6), adjacent convex surfaces (11a) can form a lap portion (11c) between each other, the thickness of the flat tube (6) can be well managed, and the thickness of the flat tube (6) Variations in height can be eliminated.
[0012]
Moreover, if the groove part (11e) which divides | segments a convex surface (11a) is formed in the middle of a convex surface (11a) like invention of Claim 4, the flux application | coating to a flat tube (6) will be carried out through this groove part (11e). Can be performed even better.
In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
Initially, the whole structure of the heat exchanger for vehicle heating manufactured by the method of this invention is demonstrated based on above-mentioned FIGS. This heat exchanger has a hot water inlet side tank 1, a hot water outlet side tank 2, and a heat exchanging core portion 3 provided between the tanks 1 and 2.
[0014]
The warm water inlet side tank 1 is provided with an inlet pipe 4 into which warm water (engine cooling water) from a vehicle engine (not shown) flows, and the warm water outlet side tank 2 is an outlet pipe that causes the warm water to flow outside and return to the engine side. 5 is provided. Since the heat exchanger of this example is vertically symmetrical as shown in FIG. 8, the hot water inlet side tank 1 and the hot water outlet side tank 2 may be turned upside down.
[0015]
Each of the tanks 1 and 2 includes a tank body 1a and 2a, and sheet metals 1b and 2b for closing the opening end faces of the tank body 1a and 2a. It is. A large number of flat tube insertion holes (not shown) are formed in the sheet metals 1b and 2b, and one or more rows are formed in the left-right direction in FIG.
[0016]
The heat exchanging core section 3 has a number of flat tubes 6 formed in a flat shape parallel to the flow direction of the heating air (in the direction of arrow A in FIG. 8) and arranged in parallel in the left-right direction in FIG. Then, corrugated fins (fin members) 7 formed in a wave shape are arranged and joined between the multiple flat tubes 6. As is well known, a large number of louvers 7a (see FIG. 1 and the like) are cut and raised obliquely at a predetermined angle with respect to the flow direction of the heating air. The rate is improving.
[0017]
Openings at both ends of the flat tube 6 are inserted and joined into tube insertion holes of the sheet metals 1b and 2b, respectively. Further, side plates 8a and 8b are arranged on the outer side of the corrugated fins 7 on the outermost side (the left and right end portions in FIG. 8) of the core part 3, and the side plates 8a and 8b are arranged on the outermost corrugated fins 7 and the sheet. Joined to the metal 1b, 2b.
[0018]
In the heat exchanger in this example, all of the component parts 1 to 8b are formed of aluminum (including an aluminum alloy), and each part is integrally joined and assembled by brazing.
Furthermore, the electric heating element unit 9 is installed in a part of the heat exchanging core section 3, and more specifically, in the example of FIG. Units 9 are installed at equal intervals. In order to install the electric heating element unit 9, one flat tube 6 and corrugated fins 7 bonded to both sides of the flat tube 6 are removed and set at a predetermined portion of the heat exchanging core 3. After forming a space portion with a predetermined interval and brazing the heat exchanger in this state, the electric heating element unit 9 is attached to the removed portion of the flat tube 6 and the corrugated fin 7 in the core portion 3 for heat exchange. Inserting.
[0019]
Therefore, the thickness t ₀ (FIG. 9) of the electric heating element unit 9 is set to be equal to the thickness of the one flat tube 6 and the corrugated fins 7 on both sides thereof, and the length L is the sheet metal 1b. 2b is set to be equivalent to the dimension between 2b.
9 and 10 illustrate the specific structure of the finned electric heating element unit 9. The electric heating element unit 9 is roughly divided into a heating element body 90, corrugated fins (fin members) 91, 92, It is comprised from the frames 93 and 94. First, the heating element main body 90 has a structure shown in FIG. 10, and includes a plate-like heating element 90a and elongated plate-like electrode plates 90b, 90c arranged on both the front and back surfaces of the heating element 90a. It has a three-layer sandwich structure.
[0020]
The periphery of the electrode plates 90b and 90c is covered with a covering member 90d made of an electrically insulating material over the entire circumference. Here, the heating element 90a is a PTC heater made of a resistor material (eg, barium titanate) having a positive resistance temperature characteristic in which the resistance value rapidly increases at a predetermined set temperature T ₀ (eg, around 150 ° C.). It is an element. Both electrode plates 90b and 90c of the heating element 90a are formed from a conductive metal material such as aluminum, copper, and stainless steel. The heating element 90a and the electrode plates 90b and 90c are brought into pressure contact with each other, thereby obtaining electrical continuity therebetween.
[0021]
The heating element main body 90 is assembled in the two frames 93 and 94 such that the covering member 90d is in pressure contact with the corrugated fins 91 and 92 on both sides. As a specific material of the covering member 90d, a highly heat-resistant resin (for example, a polyimide resin) is preferable. The electrode plate 90b is a positive electrode plate, and the electrode plate 90c is a negative electrode plate. Terminal portions 90e and 90f for electrical connection with an external circuit are integrally formed. Note that an external control circuit (not shown) is electrically connected to the terminal portions 90e and 90f, and each electric heating element unit 9 is energized from an in-vehicle power source via the external control circuit.
[0022]
Next, the corrugated fins 91 and 92 have a wave shape similar to that of the corrugated fin 7 of the core portion 3 for heat exchange, and are made of a metal having excellent thermal conductivity such as aluminum. The frames 93 and 94 are made of a metal having excellent thermal conductivity, such as aluminum and stainless steel, and are formed in a U-shape. The frames 93 and 94 have both longitudinal side surfaces (in front and rear of the air flow direction A). A plurality (two in this example) of mounting pieces 93a and 94a are bent and formed in the middle of both side surfaces.
[0023]
Then, the front end portions of the mounting pieces 93a and 94a are overlapped with each other, and the overlapped portions are joined by means such as welding and brazing, so that the two frame bodies 93 and 94 are joined together and 2 A pressing force is applied to the heating element main body 90 and the corrugated fins 91 and 92 between the two frame bodies 93 and 94, so that the heating element main body 90 and the corrugated fins 91 are placed in the inner space of the frames 93 and 94. , 92 are held.
[0024]
Reference numeral 10 denotes a fastening (band) member made of a metal material having excellent corrosion resistance, such as stainless steel, and is disposed on both the air inlet side surface and the air outlet side surface of the heat exchanging core 3. The fastening member 10 has hook portions that are bent at both ends thereof, and the hook portions are hooked into locking groove portions 8c and 8d formed in the center in the longitudinal direction of the upper and lower side plates 8a and 8b. It is hung and mounted between the upper and lower side plates 8a, 8b.
[0025]
When the fastening member 10 is attached, a tightening force in the compression direction acts on the heat exchanging core 3, so that the electric heating element unit 9 is pressed and held between the two adjacent flat tubes 6, 6. You can gain power. In FIG. 8, the fastening members 10 are disposed at only one central position in the vertical direction of the heat exchanging core 3, but the fastening members 10 may be disposed at a plurality of vertical positions.
[0026]
Next, the manufacturing method of the above-described heating heat exchanger will be described. First, a core assembling step for assembling the heat exchanger configuration is first performed. That is, as shown in FIG. 1, the flat tubes 6 and the corrugated fins 7 of the heat exchanging core portion 3 are alternately stacked, and the portion of the heat exchanging core portion 3 where the electric heating element unit 9 is installed ( In the four hatched portions in FIG. 8, in order to maintain a predetermined interval K between the two adjacent flat tubes 6, 6, a predetermined interval K is set between the two flat tubes 6, 6. A shape-retaining member (jig) 11 having the same width dimension is inserted.
[0027]
The shape-retaining member 11 is formed of a material (for example, carbon or the like) having a heat resistance against an integral brazing process, which will be described later, and having a characteristic not to be brazed with aluminum. Further, as shown in FIG. 2, the shape-retaining member 11 is in contact with the flat surface of the flat tubes 6, 6 in a direction (vertical direction in FIG. 1) orthogonal to the longitudinal direction (vertical direction in FIG. 1). In other words, an uneven surface extending in the air flow direction A) is formed. Accordingly, the shape retaining member 11 is formed with a large number of convex surfaces 11a in contact with the flat surfaces of the flat tubes 6 and 6, and concave surfaces 11b not in contact with the flat surfaces of the flat tubes 6 and 6. In addition, the longitudinal dimension of the shape retaining member 11 is slightly shorter than the longitudinal dimension of the flat tubes 6 and 6 in order to facilitate the assembling work into the core portion 3.
[0028]
Of course, the tank 1, 2, pipes 4, 5, and side plates 8a, 8b are also assembled in the above-described core assembling step to assemble the entire heat exchanger configuration shown in FIG.
Next, as described above, the assembled state of the assembled heat exchanger is held by an appropriate jig (not shown).
[0029]
Next, flux is blown from the flux injector (nozzle) 12 to the outer surface of the heat exchanger assembly, and the flux is applied to the surface of each aluminum member of the heat exchanger assembly. Here, on the surface of the shape-retaining member 11 that is in contact with the flat surfaces of the flat tubes 6, 6, a direction orthogonal to the longitudinal direction (vertical direction in FIG. 1) of the flat tubes 6, 6 (in other words, the air flow direction A). ) And the concave surface 11b of the shape-retaining member 11 is parallel to the direction of flux spraying from the flux injector 12, so that the flat tubes 6 adjacent to the left and right sides of the shape-retaining member 11 are 6, the flux can penetrate through the concave surface 11b to the joint 6c located at the center of the flat surface of the flat tubes 6 and 6, and the flux can be sufficiently applied to the vicinity of the joint 6c.
[0030]
Here, the specific configuration of the flat tube 6 will be described. The flat tube 6 is a thin aluminum clad material in which a brazing material (for example: A4000 series) is clad on both sides or one side of an aluminum core (for example: A3000 series). 1 to form two flat hot water passages 6a and 6b independently, and between these two flat hot water passages 6a and 6b. The joint portion 6c is disposed at the end. The joint portion 6c is brazed simultaneously with integral brazing of the entire heat exchanger described later.
[0031]
The corrugated fins 7 are made of an aluminum bare material (for example: A3000 series) that is not clad with a brazing material. Further, as the flux, a non-corrosive fluoride-based flux (KF / AlF ₃ or the like) is preferable.
After finishing the above-described flux application process, the heat exchanger assembly is carried into a brazing furnace while being held by a jig, and a brazing process is performed. That is, the inside of the brazing furnace is maintained in a nitrogen gas or inert gas atmosphere, and the heat exchanger assembly is heated to the brazing temperature (about 600 ° C.) in this atmosphere, so that each member of the heat exchanger is heated. The aluminum clad brazing material is melted, and the members of the heat exchanger assembly are brazed together. The brazing process takes about a few minutes.
[0032]
In this brazing process, in the flat tubes 6 and 6 adjacent to the shape-retaining member 11, the shape-retaining member 11 is in contact with the flat surfaces, but as described above, the flat tubes 6 and 6 pass through the concave surface 11b of the shape-retaining member 11. Since the flux is sufficiently applied also in the vicinity of the joint portion 6c of 6, the brazing property of the joint portion 6c of the flat tubes 6 and 6 can be maintained well.
[0033]
Further, since the shape-retaining member 11 and the flat tubes 6 and 6 are in contact with each other only by the convex surface 11a and the contact area between them is reduced, the shape-retaining member 11 having a large heat capacity is affected during brazing. Thus, it is possible to suppress the temperature increase rate of the adjacent flat tubes 6 and 6 from becoming smaller than that of the flat tubes 6 in other parts, which also contributes to securing the brazing properties of the adjacent flat tubes 6 and 6. it can.
[0034]
After completion of the brazing process, the heat exchanger assembly is carried out of the brazing furnace, and after the temperature of the heat exchanger assembly is lowered to room temperature, the assembly process of the electric heating element unit 9 is performed.
The electric heating element unit 9 alone is assembled separately from the heat exchanger assembly to complete the structure shown in FIG. Then, the four shape-retaining members 11 inserted between the two flat tubes 6 and 6 in the heat exchange core portion 3 of the heat exchanger assembly are taken out, and the two flat tubes 6 and 6 are removed. The electric heating element unit 9 is assembled in a space portion formed at a predetermined interval K so that the outer surfaces of the two frames 93 and 94 are in contact with the flat tube surfaces. After this assembly, the hooks at both ends of the fastening member 10 are hooked on the locking grooves 8c, 8d of the upper and lower side plates 8a, 8b, and the fastening member 10 is heated between the upper and lower side plates 8a, 8b. The replacement core 3 is mounted so as to be compressed.
[0035]
As a result, a tightening force that presses and holds the electric heating element unit 9 between the two flat tubes 6, 6 is applied to the heat exchanging core 3, so that the electric heating element unit 9 is connected to the two flat tubes 6. , 6 can be securely held and fixed.
(Second Embodiment)
FIG. 3 shows a shape-retaining member 11 according to the second embodiment, in which the convex surface 11a and the concave surface 11b are inclined at a predetermined angle θ downwardly to the right. A wrap portion 11c is formed between the upper convex surface 11a and the lower convex surface 11a by the inclination angle θ.
[0036]
According to the shape retaining member 11 of the first embodiment, the pressing surface by the convex surface 11a and the non-pressing surface by the concave surface 11b are alternately formed along the longitudinal direction of the flat tubes 6 and 6, and the portion of the non-pressing surface by the concave surface 11b Then, the pressing force does not act on the flat surfaces of the flat tubes 6 and 6, and it becomes difficult to manage the thickness of the flat tubes 6 and 6.
On the other hand, according to the shape retaining member 11 of the second embodiment, the pressing surface by the convex surface 11a is continuous along the longitudinal direction of the flat tubes 6 and 6 due to the presence of the wrap portion 11c of the convex surface 11a. Therefore, the thickness of the flat tubes 6 and 6 can be managed well, and variations in the thickness of the flat tubes 6 and 6 can be eliminated.
[0037]
(Third embodiment)
FIG. 4 shows a shape-retaining member 11 according to the third embodiment, which has a shape having a hollow portion 11d at the center. By forming the hollow portion 11d, the mass of the entire shape retaining member 11 is reduced, and the heat capacity of the shape retaining member 11 can be reduced by that amount. As a result, since the temperature rising rate of the shape retaining member 11 can be increased during brazing, the temperature rising rate of the adjacent flat tubes 6 and 6 due to the presence of the shape retaining member 11 can be further suppressed. it can.
[0038]
(Fourth embodiment)
FIG. 5 shows a shape-retaining member 11 according to the fourth embodiment, in which a groove 11e for dividing the central portion of the convex surface 11a is added to the shape of the convex surface 11a according to the first embodiment (FIG. 2). By the addition of the groove 11e, the flux application to the joint 6c at the center of the flat tubes 6 and 6 can be made even better.
[0039]
(Fifth embodiment)
FIG. 6 shows a shape-retaining member 11 according to the fifth embodiment, which is an example in which the shape of the convex surface 11a is changed from a rectangular shape to a wedge shape having a triangular cross section.
(Sixth embodiment)
FIG. 7 shows a shape-retaining member 11 according to the sixth embodiment, which is an example in which the shape of the convex surface 11a is changed to a curved surface shape (R shape) formed from a rectangular shape into a cross-sectional arc shape.
[0040]
(Other embodiments)
In the above embodiment, the case where the method of the present invention is applied to the heat exchanger for vehicle heating has been described. However, the method of the present invention is not limited to the vehicle heating, and is widely applied to heat exchangers for various uses. Although the case where the electric heating element unit 9 is inserted into the space portion of the predetermined interval K has been described, the method of the present invention can also be applied when an apparatus other than the electric heating element unit 9 is inserted. is there.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part in a heating heat exchanger assembly state according to a first embodiment of the present invention.
FIG. 2 is a perspective view of the shape-retaining member of FIG.
FIG. 3 is a side view of a shape retaining member according to a second embodiment of the present invention.
FIG. 4 is a perspective view of an essential part in a heating heat exchanger assembly state showing a third embodiment of the present invention.
FIG. 5 is a side view of a shape retaining member according to a fourth embodiment of the present invention.
FIG. 6 is a perspective view of essential parts in a heating heat exchanger assembly state according to a fifth embodiment of the present invention.
FIG. 7 is a perspective view of main parts in a heating heat exchanger assembly state according to a sixth embodiment of the present invention.
FIG. 8 is a perspective view of the entire heating heat exchanger according to the prior application.
9 is a perspective view of an electric heating element unit in the heating heat exchanger of FIG. 8. FIG.
10A is a partially broken perspective view of a heating element main body of the electric heating element unit, FIG. 10B is a transverse sectional view of the heating element main body, and FIG. 10C is a longitudinal section of the heating element main body. FIG. 4D is a plan view of the heat generating body main body.
FIG. 11 is a perspective view of a main part in a heating heat exchanger assembly state according to a conventional method.
[Explanation of symbols]
1, 2 ... tank, 3 ... heat exchange core, 6 ... flat tube, 6c ... junction,
7 ... corrugated fin, 9 ... electric heating element unit, 10 ... fastening member,
11 ... Shape retaining member, 11a ... Convex surface, 11b ... Concave surface, 11c ... Wrap part,
11d ... hollow part, 11e ... groove part.

Claims

The flat tubes (6) having the joint portions (6c) to be joined by brazing and the corrugated fins (7) are assembled alternately, and a predetermined width dimension (K) is provided between the flat tubes (6). A core assembly process for inserting a shape-retaining member (11) having
After this core part assembling step, a flux applying step of applying flux to the surface of the assembly of the flat tube (6) and the corrugated fin (7),
After the flux application step, the assembly is heated in a brazing furnace to braze the assembly in one piece,
The shape-retaining member (11) is made of a material having heat resistance against brazing temperature and not brazed, so that the shape-retaining member (11) is taken out after brazing, and the flat tube (6) A method of manufacturing a heat exchanger that forms a space portion having a predetermined width dimension (K) between each other,
An uneven surface having a convex surface (11a) and a concave surface (11b) extending in a direction perpendicular to the longitudinal direction of the flat tube (6) on the surface of the shape retaining member (11) contacting the flat tube (6). None, The manufacturing method of the heat exchanger characterized by the said shape-retaining member (11) being in contact with the surface of the said flat tube (6) in the part of the said convex surface (11a).

The method for manufacturing a heat exchanger according to claim 1, wherein the electric heating element unit (9) is assembled in a space formed after the shape-retaining member (11) is taken out.

The heat according to claim 1 or 2, wherein the convex surface (11a) and the concave surface (11b) are inclined at a predetermined angle (θ) with respect to a direction orthogonal to the longitudinal direction of the flat tube (6). Exchanger manufacturing method.

The method for manufacturing a heat exchanger according to any one of claims 1 to 3, wherein a groove (11e) for dividing the convex surface (11a) is formed in the middle of the convex surface (11a).