JP3774022B2

JP3774022B2 - Aluminum alloy heat exchanger

Info

Publication number: JP3774022B2
Application number: JP05760097A
Authority: JP
Inventors: 正剛新濱
Original assignee: Calsonic Kansei Corp
Current assignee: Calsonic Kansei Corp
Priority date: 1997-03-12
Filing date: 1997-03-12
Publication date: 2006-05-10
Anticipated expiration: 2017-03-12
Also published as: JPH10253283A

Description

【０００１】
【産業上の利用分野】
この発明に係るアルミニウム合金製熱交換器は、例えば自動車用空調機を構成するコンデンサとして利用する。
【０００２】
【従来の技術】
自動車用空調機に組み込み、コンプレッサで圧縮されて温度上昇した冷媒を放熱して凝縮液化させる為のコンデンサとして、例えば図６に示す様なアルミニウム合金製の熱交換器が広く使用されている。この熱交換器は、例えば実開平４−９４１５９号公報に記載されたものである。先ず、この従来構造に就いて説明する。
【０００３】
１対のヘッダ１ａ、１ｂは、水平方向に互いに間隔をあけて平行に、それぞれ上下方向に配置されている。これら各ヘッダ１ａ、１ｂは、それぞれアルミニウム合金により円管状に造られて、蓋体９、９によりそれぞれの上下両端開口部を塞がれている。各ヘッダ１ａ、１ｂの側面で互いに対向する部分には、それぞれがスリット状である複数の通孔２、２を形成しており、各通孔２、２の内側にそれぞれ伝熱管３、３の両端部を、がたつきなく挿入している。これら各伝熱管３、３は、それぞれがアルミニウム合金製の板材により扁平管状に形成されている。又、隣り合う伝熱管３、３の間にはフィン４、４を挟持している。これら各フィン４、４は、それぞれがアルミニウム合金製の薄板を波形に形成して成るコルゲート型のものである。
【０００４】
更に、上記１対のヘッダ１ａ、１ｂのうちの一方（図６の左方）のヘッダ１ａの上部には、このヘッダ１ａ内に冷媒蒸気を送り込む為の送り込み管５を、他方（図６の右方）のヘッダ１ｂの下部には、液状冷媒を取り出す為の取り出し管６を、それぞれ設けている。尚、上記各伝熱管３、３と各フィン４、４とから成るコア部７の上下両側にはサイドサポート８、８を設け、各サイドサポート８、８の両端部を上記各ヘッダ１ａ、１ｂの上下両端部に接合して、上記コア部７の補強を図っている。上記各フィン４、４は、両端の伝熱管３、３の外側面と上記各サイドサポート８、８との間にも設けている。又、図示は省略したが、上記１対のヘッダ１ａ、１ｂの一方又は双方の内側に設けた隔壁により、当該ヘッダ内を複数の室に仕切り、冷媒が上記両ヘッダ１ａ、１ｂ同士の間を折り返しつつ流れる様に構成する場合もある。この場合に、冷媒が両ヘッダ１ａ、１ｂ同士の間で１乃至２往復（所謂２パス又は４パス）する様に構成すれば、上記送り込み管５と取り出し管６との両方を、上記一方のヘッダ１ａの上下両端部に設ける。
【０００５】
上述の様なアルミニウム合金製熱交換器の構成各部材は、図６に示す様に組み立てた状態で、やはりアルミニウム合金製のろう材により互いにろう付け接合される。この為、隣り合う部材同士の接合部には上記ろう材を存在させる。実際の場合には、上記各ヘッダ１ａ、１ｂ及び各伝熱管３、３を構成するアルミニウム合金製の板材として、内外両周面にろう材を積層した、所謂クラッド材を使用する。又、各サイドサポート８、８も、少なくともフィン４、４側にろう材を積層した、クラッド材を使用する。
【０００６】
これら各部材１ａ、１ｂ、３、８の表面に存在するろう材は、ろう付けの為の加熱により溶けて、上記各ヘッダ１ａ、１ｂの上下両端部周面と各蓋体９、９の周面との間、前記各通孔２、２の内周縁と各伝熱管３、３の端部外周面との間、各伝熱管３、３の上下両側面と各フィン４、４との当接部、ヘッダ１ａの上部に形成した通孔の内周縁と送り込み管５の基端部外周面との間、ヘッダ１ｂの下部に形成した通孔の内周縁と取り出し管６の基端部外周面との間に行き渡る。そして、冷却固化後は、これら各部材１ａ、１ｂ、３、４、５、６、８、９同士を結合固定すると共に、結合部の気密、液密保持を図る。尚、ろう付け性を向上させる為に、加熱に先立って、ろう付けすべき部材の表面にフラックスを付着する。
【０００７】
上述の様に構成されるアルミニウム合金製熱交換器をコンデンサとして使用する場合には、上記送り込み管５から冷媒蒸気を送り込むと共に、上記コア部７の表裏方向に冷却用の空気を流通させる。上記冷媒蒸気は、上記一方のヘッダ１ａから他方のヘッダ１ｂに向けて複数本の伝熱管３、３を流れる間に、上記冷却用の空気との間で熱交換を行なって冷却され、凝縮液化した状態で、上記取り出し管６から取り出される。
【０００８】
又、実公平７−３１７３号公報には、ヘッダの端部開口を塞ぐ蓋体に係止突起を設け、この係止突起を利用して、上記ヘッダを含むアルミニウム合金製熱交換器を車体に支持する構造が記載されている。但し、この公報に記載されている構造の場合には、上記蓋体としてアルミニウム合金の削り出しにより造ったものを利用する為、蓋体の材料費並びに加工費が嵩む事が避けられない。
【０００９】
又、上記公報に記載された構造のものを含め、従来のアルミニウム合金製熱交換器の場合には、各ヘッダ１ａ、１ｂの下端開口部を塞ぐ蓋体９、９のろう付け面積を確保する事が難しく、この蓋体９、９装着部分の耐圧強度が不足する可能性があった。即ち、上記ヘッダ１ａ（又は１ｂ。以下同じ。）の下端開口部を蓋体９で塞ぐには、例えば図７に示す様に、ヘッダ１ａの下端部を有底円筒状の蓋体９に圧入した後、これら両部品１ａ、９を加熱ろう付けする。ろう付けの為のろう材は、上記ヘッダ１ａの外周面（又は内周面）にクラッドされたろう材が流下する事により供給される。
【００１０】
上記ヘッダ１ａの外周面を流下したろう材が、このヘッダ１ａの外周面と上記蓋体９の内周面との間に入り込めば、このヘッダ１ａに対する蓋体９のろう付け面積を確保できる。ところが、上記両周面同士の嵌合状態は圧入であり、これら両周面同士の間には殆ど隙間が存在しない為、フラックスがこれら両周面同士の間に入り込みにくく、ろう材は図８に示す様に、上記蓋体９の上端縁にフィレット１０として溜る。勿論、上記ヘッダ１ａの下端部外周面で上記蓋体９の内周面と対向する部分にもろう材層が存在するが、上述した様にフラックスはこれら両周面同士の間に入り込みにくく、これら両周面同士のろう付けが不良になり易いだけでなく、場合によっては十分なろう材が確保されず、上記した様な耐圧強度の不足が発生する可能性がある。又、上記蓋体９内にヘッダ１ａの下端部を圧入する作業は面倒で、しばしば蓋体９内にヘッダ１ａを斜めに挿入しがちである。そして、斜めに挿入したままろう付け作業を行なった場合には、十分なろう付け面積を確保する事ができず、上述の様なろう付け不良に基づく耐圧強度の不足が発生し易い。
【００１１】
【先発明の説明】
上述の様な不都合を防止する為、本発明者は先に、図９〜１２に示す様な、ヘッダと蓋体とのろう付け部の改良に関するアルミニウム合金製熱交換器の構造を発明した（特願平８−４９２１３号）。この先発明のアルミニウム合金製熱交換器の場合には、各ヘッダ１ａの下端開口部を蓋体９ａにより塞ぎ、この蓋体９ａを覆う状態でブラケット１１を上記ヘッダ１ａの下端部に固定している。このブラケット１１は、アルミニウム合金製の板材に、絞り加工等の塑性加工を施す事により一体成形したもので、上記ヘッダ１ａの下端部に外嵌する円筒部１２と、この円筒部１２の下端開口部を塞ぐ底板部１３と、この底板部１３の中央部から上記円筒部１２と反対側である下方に突出する係止突部１４とを備える。そして、上記円筒部１２の内周面と上記ヘッダ１ａの下端部外周面とをろう付けする事により、上記ブラケット１１を、上記蓋体９ａと共に、上記ヘッダ１ａの下端部に固定している。
【００１２】
特に、先発明のアルミニウム合金製熱交換器の場合には、上記円筒部１２の内周面に、上記ヘッダ１ａの下端部外周面に向けて突出する、複数の小突起１５、１５を形成している。従って、上記ヘッダ１ａの下端開口部を塞ぐ蓋体９ａを覆う状態で上記ヘッダ１ａの下端部に固定するブラケット１１を構成する、円筒部１２の内周面と上記ヘッダ１ａの下端部外周面との間には、上記複数の小突起１５、１５の高さに見合う隙間１６が形成される。この為、この隙間１６から上記ブラケット１１の円筒部１２の内周面と上記ヘッダ１ａの下端部外周面との間にフラックスを流入させる事が可能となり、上記蓋体９ａ及びブラケット１１と上記ヘッダ１ａとのろう付け部を、フラックスで完全に覆う事ができる。更に、ろう付け時にはろう材がこの隙間１６に流入する。従って、上記円筒部１２の内周面と上記ヘッダ１ａの下端部外周面とを、十分に広い面積でろう付けできる。
【００１３】
【発明が解決しようとする課題】
上述の様に構成される先発明に係るアルミニウム合金製熱交換器の場合、次の様な点を改良する事が望まれている。即ち、ブラケット１１構成する円筒部１２の内周面と各ヘッダ１ａの下端部外周面とを、全周に亙って隙間なくろう付けできれば良いが、場合によっては、上記両周面同士のろう付け部に、ピンホール程度の微小通孔が発生する可能性がある。この様な微小通孔が形成される理由は、次の通りである。
【００１４】
上記ヘッダ１ａの下端部外周面と蓋体９ａと上記ブラケット１１とにより周囲を囲まれる空間１７内には、空気の他、ろう付けの為の加熱により温度上昇した状態では、フラックスの蒸気が存在する。これらの気体の体積は、ろう付けの為の温度上昇に伴って増大する。この為、上記各気体は、ブラケット１１を構成する円筒部１２の内周面と上記ヘッダ１ａの下端部外周面との間の隙間１６内に流入した溶融状態のろう材を押し退けつつ、上記空間１７外に排出される。この結果、上記隙間１６内に流入したろう材の一部に、上記空間１７の内外を連通させるピンホール状の微小通孔が形成される可能性がある。
【００１５】
この様な微小通孔自体は、特に上記ヘッダ１ａとブラケット１１とのろう付け強度を低下させる事はない。但し、この微小通孔を通じて上記空間１７内に、雨水等の異物が入り込む可能性がある。そして、この様な異物の進入に基づき、上記空間１７の内面を構成する上記蓋体９ａ或はヘッダ１ａに、腐食が発生する可能性がある為、好ましくない。
本発明は、この様な腐食の発生を防止すべく、上記ヘッダ１ａとブラケット１１との間の空間１７の内外を連通させる微小通孔が形成される事を防止する構造を実現するものである。
【００１６】
【課題を解決する為の手段】
本発明のアルミニウム合金製熱交換器は、前述した従来のアルミニウム合金製熱交換器と同様に、それぞれがアルミニウム合金により管状に造られ、水平方向に互いに間隔をあけてそれぞれ上下方向に配置された１対のヘッダと、各ヘッダの上下両端開口部を塞ぐ蓋体と、上記各ヘッダの側面で互いに対向する部分に形成された複数の通孔と、それぞれがアルミニウム合金により扁平管状に形成され、上記各通孔の内側にそれぞれの両端部をがたつきなく挿入された複数本の伝熱管と、それぞれがアルミニウム合金製の薄板を波形に形成して成り、隣り合う伝熱管の間に挟持されたフィンとを備え、上記１対のヘッダの上下両端部と上記各蓋体との間、上記各通孔の内周縁と上記各伝熱管の両端部外周面との間、上記各伝熱管の側面と上記フィンとの当接部を、それぞれアルミニウム合金製のろう材によりろう付けして成る。
【００１７】
特に、本発明のアルミニウム合金製熱交換器に於いては、少なくとも上記各ヘッダの下端開口部を塞ぐ蓋体を覆う状態で上記各ヘッダの下端部に固定されるブラケットが設けられている。このブラケットは、上記各ヘッダの下端部を内嵌する円筒部と、この円筒部の内周面から突出した小突起と、この円筒部の下端開口部を塞ぐ底板部と、この底板部の一部から下方に突出する係止突部と、上記円筒部と底板部とで囲まれる空間を外部に連通させる連通孔とを備える。そして、上記ブラケットは、上記円筒部の内周面と上記各ヘッダの下端部外周面とをろう付けする事により、上記各ヘッダの下端部に固定されている。
【００１８】
【作用】
上述の様に構成される本発明のアルミニウム合金製熱交換器によれば、各ヘッダの下端開口部を塞ぐ蓋体を覆う状態でこれら各ヘッダの下端部に固定されるブラケットを構成する円筒部の内周面とヘッダの下端部外周面との間には、小突起の高さに見合う隙間が形成される。そして、この隙間から上記ブラケットを構成する円筒部の内周面とヘッダの下端部外周面との間にフラックスを流入させる事が可能となり、このブラケットのろう付け部を、フラックスで完全に覆う事ができる。更に、ろう付け時にはろう材がこの隙間に流入する。従って、上記円筒部の内周面とヘッダの下端部外周面とを十分に広い面積でろう付けできる。
【００１９】
又、ろう付けの為の加熱に伴って、上記円筒部と底板部とで囲まれる空間内に存在する気体の体積が増大した場合に、この気体は、ブラケットに形成した連通孔を通じて、上記空間外に排出される。従って、上記気体が上記隙間内に流入したろう材を押し退ける事がなく、このろう材に微小通孔が形成される事がなくなる。
【００２０】
【発明の実施の形態】
図１〜４は、本発明の実施の形態の第１例を示している。尚、本例の特徴は、各ヘッダ１ａの下端部に、蓋体９ａとブラケット１１ａとを装着した部分の構造にある。アルミニウム合金製熱交換器全体の構成及び作用は、前述の図６に示した従来構造と同様であるから図示及び説明を省略し、以下、本発明の特徴部分を中心に説明する。上記ヘッダ１ａの下端開口部は、蓋体９ａにより塞いでいる。この蓋体９ａは、円筒部１８の上端を天板部１９により塞ぎ、この円筒部１８の下端縁部に外向フランジ状の鍔部２０を形成して成る。この様な蓋体９ａは、上記円筒部１８を上記ヘッダ１ａの下端部に圧入すると共に、上記鍔部２０の上面を上記ヘッダ１ａの下端縁に当接若しくは近接させた状態で、このヘッダ１ａの下端部に嵌合固定している。
【００２１】
そして、上記ヘッダ１ａの下端開口部を塞ぐ上記蓋体９ａを覆う状態で上記ヘッダ１ａの下端部に、ブラケット１１ａを外嵌固定している。このブラケット１１ａは、円筒部１２と、複数の小突起１５、１５と、底板部１３と、係止突部１４とを備える。このうちの円筒部１２の内径Ｒ₁₂は、上記ヘッダ１ａの下端部の外径Ｄ_1aよりも僅かに（例えば０．６mm以下）大きくしている。又、上記複数の小突起１５、１５は、上記円筒部１２の内周面に突設している。これら各小突起１５、１５は、上記円筒部１２の内周面の３個所以上（図示の例では４個所）に、円周方向に亙って等間隔に、且つ各部毎に軸方向（図１、２、４の上下方向、図３の表裏方向）に離隔して複数個ずつ（図示の例では２個ずつ、合計８個）設けている。
【００２２】
又、各部材９ａ、１ａの自由状態で、これら複数個の小突起１５、１５の最大内接円の直径Ｄ₁₅は、上記ヘッダ１ａの下端部の外径Ｄ_1aよりも僅かに小さく（Ｒ₁₂＞Ｄ_1a＞Ｄ₁₅）している。尚、この様な小突起１５、１５を形成する作業は、上記円筒部１２を形成する以前に行なう。即ち、上記ブラケット１１ａは、円形の平板を絞り加工する事により造るが、この絞り加工を行なう以前に、上記平板の一部で上記円筒部１２の内周面に対応する部分に上記各小突起１５、１５を、プレス加工により突出形成しておく。尚、上記各小突起１５、１５を、４個以上形成する場合には、必ずしも上述した様に、円周方向に亙って等間隔に、且つ各部毎に軸方向に離隔して設ける必要はない。例えば、小突起１５、１５を円周方向に亙って不均等な間隔で形成しても良い。
【００２３】
又、上記底板部１３は、上記円筒部１２の下端開口部を塞いでいる。又、上記係止突部１４は、上記底板部１３の中央部から下方に突出している。この係止突部１４は、下端部が半球状に塞がれ、上端が上記底板部１３の中央部に開口した、有底円筒状に形成している。更に、上記底板部１３の一部で上記係止突部１４から外れた部分には、連通孔２１を形成している。この連通孔２１は、前記蓋体９ａとヘッダ１ａと上記円筒部１２と底板部１３とで囲まれる空間１７を、外部に連通させる。
【００２４】
前述の様な形状を有する蓋体９ａと上述の様な形状を有するブラケット１１ａとにより、上記ヘッダ１ａの下端開口部を塞ぐ作業は、次の様にして行なう。先ず、図１に示す様に、上記ヘッダ１ａの下端部に上記蓋体９ａを構成する円筒部１８を押し込むと共に、上記ブラケット１１ａを構成する円筒部１２内に、上記ヘッダ１ａの下端部を押し込む。この押し込み作業の結果、上記複数の小突起１５、１５の先端が上記ヘッダ１ａの下端部外周面に弾性的に押し付けられ、この下端部外周面と上記円筒部１２の内周面との間に、円筒状の隙間１６が形成される。上記円筒部１２の内径Ｒ₁₂と上記ヘッダ１ａの下端部の外径Ｄ_1aとの差の２分の１である、この隙間１６の厚さＴ₁₆｛＝（Ｒ₁₂−Ｄ_1a）／２｝は僅か（例えば０．３mm以下）なものである。尚、上記複数の小突起１５、１５の存在に基づき、挿入作業時に上記ヘッダ１ａに対して上記ブラケット１１ａが傾斜しにくい。従って、上記隙間１６の厚さＴ₁₆は、全周並びに全長に亙ってほぼ均一になる。
【００２５】
上述の様にヘッダ１ａの下端部に蓋体９ａを内嵌すると共にブラケット１１ａを外嵌した状態で、アルミニウム合金製熱交換器のろう付け作業を行なえば、後述する様に、隙間１６内に十分な量のフラックスが流入する。又、上記ヘッダ１ａの内周面に積層したろう材が、この内周面と上記蓋体９ａを構成する円筒部１８の外周面とをろう付けすると共に、上記ヘッダ１ａの外周面に積層されたろう材が、上記隙間１６に流入する。即ち、上述した様にこの隙間１６の厚さＴ₁₆は僅かなものであるから、この隙間１６の上端開口部に達したフラックス及び（溶融した液状の）ろう材が、毛細管現象によって上記隙間１６内に入り込み、この隙間１６の全体に亙って広がる。従って、温度低下後、このろう材が固化した後に於いては、上記円筒部１２の内周面とヘッダ１ａの下端部外周面とが、十分に広い面積でろう付けされる。
【００２６】
尚、本発明は、ヘッダ１ａの表面に積層し、溶融状態でこのヘッダ１ａの外周面を流下するろう材を、ブラケット１１ａとヘッダ１ａとの間のろう付けに有効に利用すべく考慮している。更に、本例の場合には、上記隙間１６内にろう材が入り込むのに先立って、上記ヘッダ１ａの外周面に付着したフラックスが、この隙間１６内に入り込む。即ち、アルミニウム合金製熱交換器の構成部材同士をろう付けする際には、この構成部材を図６に示す様に仮組み付けした後、加熱に先立って表面にフラックスを付着させる。このうち、上記ヘッダ１ａの外周面に付着したフラックスは、加熱の比較的初期段階に於いて、上記隙間１６に入り込む。この結果、上記ブラケット１１ａを構成する円筒部１２の内周面とヘッダ１ａの下端部外周面との間に十分な量のフラックスを供給して、この部分のろう付け性を向上させる事ができる。又、フラックスの蒸気は、上記蓋体９ａとヘッダ１ａとの嵌合部にも達し、この嵌合部のろう付け性を向上させる。
【００２７】
尚、上記蓋体９ａを構成する円筒部１８の外周面とヘッダ１ａの下端部内周面とのろう付け面積は、従来構造に比べて広くなる事はない。但し、本発明の構造の場合には、上記蓋体９ａをヘッダ１ａの下端部に向け抑え付けているブラケット１１ａの円筒部１２が、このヘッダ１ａに対して十分に広い面積でろう付けされる。又、ヘッダ１ａの下端縁と蓋体９ａの鍔部２０の上面との間の隙間にろう材及びフラックスが流入し、上記下端縁と上記上面とをろう付けする。従って、上記蓋体９ａの耐圧強度並びに気密性を十分に確保できる。尚、上記蓋体９ａの円筒部１８の外周面に複数の小突起を突設することにより、この円筒部１８の外周面と上記ヘッダ１ａの下端部内周面との間に円筒状の隙間を形成すれば、上記円筒部１８の外周面とヘッダ１ａの下端部内周面とのろう付け面積を広くできる。
【００２８】
更に、本発明のアルミニウム合金製熱交換器の場合には、上記ブラケット１１ａを構成する底板部１３の一部に連通孔２１を形成し、この連通孔２１によって、内部である前記空間１７内に存在する空気及びフラックス蒸気等の気体を排出する様にしている。従って、上記気体が、上記円筒部１２の内周面とヘッダ１ａの下端部外周面との間に存在する隙間１６内に流入したろう材を押し退ける事がなく、このろう材に微小通孔が形成される事がなくなる。
【００２９】
上述の様にして、上記ヘッダ１ａの下端開口を蓋体９ａにより塞ぐと共に、この蓋体９ａを覆う状態で上記ブラケット１１ａを上記ヘッダ１ａの下端部に固定したならば、図４に示す様に、このブラケット１１ａの係止突部１４に、ゴム、エラストマー等の弾性材により円環状に造った緩衝材２２を外嵌する。そして、上記係止突部１４の下半部で上記緩衝材２２の下面から突出した部分を、車体側に設けた係止孔に挿入する事により、上記ヘッダ１ａを含むアルミニウム合金製熱交換器を、車体に対して緩衝支持する。
【００３０】
次に、図５は、本発明の実施の形態の第２例を示している。本例の場合には、ブラケット１１ｂを構成する係止突部１４ａの下端を開口させてこの係止突部１４ａを円筒状に形成し、この係止突部１４ａの内側部分に、円筒部１２と底板部１３とで囲まれる空間を外部に連通させる連通孔としての機能を持たせている。その他の構成及び作用は、上述した第１例の場合と同様であるから、重複する説明を省略する。
【００３１】
【発明の効果】
本発明のアルミニウム合金製熱交換器は、以上に述べた通り構成され作用するので、アルミニウム合金製熱交換器の耐圧強度を十分に確保して、製品の歩留を向上させる事ができる。又、ブラケットを構成する円筒部の内周面とヘッダの下端部外周面との間の隙間を埋めるろう材に微小通孔が形成される事を防止できるので、上記ブラケットの内側に雨水等の異物が進入する事を有効に防止できる。この為、上記ブラケットの内側部分に対向する蓋体やヘッダに腐食が発生する事を防止して、アルミニウム合金製熱交換器の耐久性を確保できる。
【図面の簡単な説明】
【図１】本発明の実施の形態の第１例を示す、要部縦断面図。
【図２】ブラケットのみを取り出して示す断面図。
【図３】同じく底面図。
【図４】ヘッダとブラケットとをろう付け後、緩衝材を装着した状態を示す、要部正面図。
【図５】本発明の実施の形態の第２例を示す、図２と同様の図。
【図６】従来から知られたアルミニウム合金製熱交換器の１例を示す斜視図。
【図７】従来構造を示す、ヘッダの下端部と蓋体との正面図。
【図８】従来構造を組み立てた状態で示す部分正面図。
【図９】先発明に係る構造を構成する、ブラケットの正面図。
【図１０】同じく平面図。
【図１１】先発明に係る構造を構成する、ヘッダの下端部と蓋体及びブラケットとを組み合わせ、ろう付け以前の状態で示す部分切断正面図。
【図１２】同じくろう付け後の状態で示す部分切断正面図。
【符号の説明】
１ａ、１ｂヘッダ
２通孔
３伝熱管
４フィン
５送り込み管
６取り出し管
７コア部
８サイドサポート
９、９ａ蓋体
１０フィレット
１１、１１ａ、１１ｂブラケット
１２円筒部
１３底板部
１４、１４ａ係止突部
１５小突起
１６隙間
１７空間
１８円筒部
１９天板部
２０鍔部
２１連通孔
２２緩衝材[0001]
[Industrial application fields]
The aluminum alloy heat exchanger according to the present invention is used as, for example, a capacitor constituting an automotive air conditioner.
[0002]
[Prior art]
For example, an aluminum alloy heat exchanger as shown in FIG. 6 is widely used as a condenser for dissipating and condensing liquid refrigerant that has been built into an automobile air conditioner and compressed by a compressor and whose temperature has risen. This heat exchanger is described in, for example, Japanese Utility Model Publication No. 4-94159. First, this conventional structure will be described.
[0003]
The pair of headers 1a and 1b are arranged in the vertical direction in parallel to each other with a space in the horizontal direction. Each of the headers 1a and 1b is made of an aluminum alloy in a circular tube shape, and the upper and lower end openings are closed by the lids 9 and 9, respectively. A plurality of through holes 2 and 2 each having a slit shape are formed on the side surfaces of the headers 1a and 1b facing each other, and the heat transfer tubes 3 and 3 are respectively formed inside the through holes 2 and 2, respectively. Both ends are inserted without rattling. Each of these heat transfer tubes 3 and 3 is formed in a flat tubular shape by a plate material made of an aluminum alloy. Further, fins 4 and 4 are sandwiched between adjacent heat transfer tubes 3 and 3. Each of the fins 4 and 4 is a corrugated type formed by forming a thin plate made of an aluminum alloy into a corrugated shape.
[0004]
Further, on the upper portion of one of the pair of headers 1a and 1b (left side in FIG. 6), a feeding pipe 5 for feeding refrigerant vapor into the header 1a is provided on the other side (in FIG. 6). A take-out pipe 6 for taking out the liquid refrigerant is provided at the lower part of the header 1b on the right side. In addition, side supports 8 and 8 are provided on both upper and lower sides of the core portion 7 including the heat transfer tubes 3 and 3 and the fins 4 and 4, and both end portions of the side supports 8 and 8 are provided on the upper and lower sides of the headers 1a and 1b. The core portion 7 is reinforced by joining both ends. The fins 4, 4 are also provided between the outer surfaces of the heat transfer tubes 3, 3 at both ends and the side supports 8, 8. Although not shown in the figure, a partition provided inside one or both of the pair of headers 1a and 1b divides the header into a plurality of chambers, and a refrigerant is provided between the headers 1a and 1b. There is a case where it is configured to flow while being folded. In this case, if the refrigerant is configured to make one or two reciprocations (so-called two-pass or four-pass) between the headers 1a and 1b, both the feed pipe 5 and the take-out pipe 6 are Provided at both upper and lower ends of the header 1a.
[0005]
The constituent members of the heat exchanger made of aluminum alloy as described above are brazed and joined together with a brazing material made of aluminum alloy in the assembled state as shown in FIG. For this reason, the said brazing material exists in the junction part of adjacent members. In an actual case, a so-called clad material in which a brazing material is laminated on both inner and outer peripheral surfaces is used as the aluminum alloy plate material constituting each of the headers 1a and 1b and the heat transfer tubes 3 and 3. The side supports 8 and 8 are also made of a clad material in which a brazing material is laminated at least on the fins 4 and 4 side.
[0006]
The brazing material existing on the surfaces of these members 1a, 1b, 3, 8 is melted by heating for brazing, and the peripheral surfaces of the upper and lower ends of each header 1a, 1b and the periphery of each lid 9, 9 are melted. Between the inner peripheral edge of each of the through holes 2 and 2 and the outer peripheral surface of the end of each of the heat transfer tubes 3 and 3, and between the upper and lower side surfaces of each of the heat transfer tubes 3 and 3 and the fins 4 and 4. Between the contact portion, the inner peripheral edge of the through hole formed in the upper portion of the header 1a and the outer peripheral surface of the proximal end portion of the feed pipe 5, and the inner peripheral edge of the through hole formed in the lower portion of the header 1b Go across the plane. And after cooling and solidifying, these members 1a, 1b, 3, 4, 5, 6, 8, and 9 are coupled and fixed together, and the coupling portion is kept airtight and liquid tight. In addition, in order to improve brazing property, a flux adheres to the surface of the member which should be brazed before a heating.
[0007]
When the aluminum alloy heat exchanger configured as described above is used as a condenser, the refrigerant vapor is fed from the feed pipe 5 and cooling air is circulated in the front and back direction of the core portion 7. While the refrigerant vapor flows through the plurality of heat transfer tubes 3 and 3 from the one header 1a toward the other header 1b, the refrigerant vapor is cooled by exchanging heat with the cooling air, and is condensed and liquefied. In this state, it is taken out from the take-out tube 6.
[0008]
Also, in Japanese Utility Model Publication No. 7-3173, a locking projection is provided on a lid that closes the end opening of the header, and by using this locking projection, an aluminum alloy heat exchanger including the header is attached to the vehicle body. The supporting structure is described. However, in the case of the structure described in this publication, since the lid body is made by cutting out an aluminum alloy, it is inevitable that the material cost and processing cost of the lid body increase.
[0009]
In addition, in the case of a conventional aluminum alloy heat exchanger including the one described in the above publication, a brazing area for the lids 9 and 9 that closes the lower end openings of the headers 1a and 1b is secured. This is difficult, and there is a possibility that the pressure-resistant strength of the lid 9, 9 mounting portion will be insufficient. That is, in order to close the lower end opening of the header 1a (or 1b, the same shall apply hereinafter) with the lid 9, for example, as shown in FIG. 7, the lower end of the header 1a is press-fitted into the bottomed cylindrical lid 9. After that, both the parts 1a and 9 are heated and brazed. The brazing material for brazing is supplied when the brazing material clad on the outer peripheral surface (or inner peripheral surface) of the header 1a flows down.
[0010]
If the brazing material flowing down the outer peripheral surface of the header 1a enters between the outer peripheral surface of the header 1a and the inner peripheral surface of the lid body 9, the brazing area of the lid body 9 with respect to the header 1a can be secured. . However, the fitting state between the two peripheral surfaces is press-fitting, and there is almost no gap between the two peripheral surfaces. Therefore, the flux hardly enters between the two peripheral surfaces. As shown in FIG. 4, the lid 9 accumulates as a fillet 10 at the upper end edge. Of course, there is a brazing filler metal layer on the outer peripheral surface of the lower end portion of the header 1a and also on the portion facing the inner peripheral surface of the lid body 9, but as described above, the flux is difficult to enter between these peripheral surfaces, Not only is the brazing between these two peripheral surfaces likely to be defective, but in some cases, a sufficient brazing material is not secured, and there is a possibility that the above-mentioned deficiency in pressure resistance may occur. Also, the operation of press-fitting the lower end of the header 1a into the lid 9 is troublesome, and the header 1a tends to be inserted into the lid 9 obliquely. When the brazing operation is performed while being inserted obliquely, a sufficient brazing area cannot be ensured, and the pressure strength is insufficient due to the brazing failure as described above.
[0011]
[Description of the invention]
In order to prevent the inconveniences as described above, the present inventor previously invented the structure of an aluminum alloy heat exchanger as shown in FIGS. 9 to 12 for improving the brazed portion between the header and the lid ( Japanese Patent Application No. 8-49213). In the case of this aluminum alloy heat exchanger according to the present invention, the lower end opening of each header 1a is closed with a lid 9a, and the bracket 11 is fixed to the lower end of the header 1a so as to cover the lid 9a. . The bracket 11 is integrally formed by subjecting a plate made of aluminum alloy to plastic processing such as drawing, and has a cylindrical portion 12 that is externally fitted to the lower end portion of the header 1a, and a lower end opening of the cylindrical portion 12. A bottom plate portion 13 that closes the portion, and a locking projection 14 that protrudes downward from the center portion of the bottom plate portion 13 on the opposite side to the cylindrical portion 12. And the said bracket 11 is being fixed to the lower end part of the said header 1a with the said cover body 9a by brazing the inner peripheral surface of the said cylindrical part 12, and the lower end part outer peripheral surface of the said header 1a.
[0012]
In particular, in the case of the heat exchanger made of aluminum alloy of the previous invention, a plurality of small protrusions 15, 15 projecting toward the outer peripheral surface of the lower end portion of the header 1 a are formed on the inner peripheral surface of the cylindrical portion 12. ing. Accordingly, an inner peripheral surface of the cylindrical portion 12 and an outer peripheral surface of the lower end portion of the header 1a that constitute the bracket 11 that is fixed to the lower end portion of the header 1a in a state of covering the lid body 9a that covers the lower end opening of the header 1a. A gap 16 corresponding to the height of the plurality of small protrusions 15 and 15 is formed between them. For this reason, it is possible to allow flux to flow from the gap 16 between the inner peripheral surface of the cylindrical portion 12 of the bracket 11 and the outer peripheral surface of the lower end portion of the header 1a, and the lid body 9a, the bracket 11 and the header. The brazed part with 1a can be completely covered with the flux. Further, the brazing material flows into the gap 16 during brazing. Therefore, the inner peripheral surface of the cylindrical portion 12 and the outer peripheral surface of the lower end portion of the header 1a can be brazed with a sufficiently large area.
[0013]
[Problems to be solved by the invention]
In the case of the heat exchanger made of aluminum alloy according to the prior invention configured as described above, it is desired to improve the following points. That is, it is sufficient that the inner peripheral surface of the cylindrical portion 12 constituting the bracket 11 and the outer peripheral surface of the lower end portion of each header 1a can be brazed over the entire circumference without any gaps. There is a possibility that a minute through hole of the size of a pinhole may occur in the attachment portion. The reason why such fine through holes are formed is as follows.
[0014]
In the space 17 surrounded by the outer peripheral surface of the lower end portion of the header 1a, the lid 9a and the bracket 11, in addition to air, there is flux vapor in a state where the temperature is increased by heating for brazing. To do. The volume of these gases increases with increasing temperature for brazing. For this reason, each said gas pushes away the brazing material of the molten state which flowed in the clearance gap 16 between the internal peripheral surface of the cylindrical part 12 which comprises the bracket 11, and the lower end part outer peripheral surface of the said header 1a, and said space 17 is discharged outside. As a result, a pinhole-shaped minute through hole that allows communication between the inside and outside of the space 17 may be formed in a part of the brazing material that has flowed into the gap 16.
[0015]
Such a small through hole itself does not particularly reduce the brazing strength between the header 1a and the bracket 11. However, foreign substances such as rainwater may enter the space 17 through the minute through holes. And, since the lid 9a or the header 1a constituting the inner surface of the space 17 may be corroded based on the entry of such foreign matter, it is not preferable.
In order to prevent the occurrence of such corrosion, the present invention realizes a structure that prevents the formation of a minute through hole that communicates the inside and outside of the space 17 between the header 1a and the bracket 11. .
[0016]
[Means for solving the problems]
The aluminum alloy heat exchangers of the present invention are each made of aluminum alloy in a tubular shape and arranged in the vertical direction at intervals in the horizontal direction, like the conventional aluminum alloy heat exchangers described above. A pair of headers, a lid that closes the upper and lower end openings of each header, a plurality of through holes formed in portions facing each other on the side surfaces of each header, each formed in a flat tubular shape with an aluminum alloy, A plurality of heat transfer tubes inserted into the inner side of each of the through holes without rattling, and each formed by forming a corrugated aluminum alloy thin plate and sandwiched between adjacent heat transfer tubes Fins, between the upper and lower ends of the pair of headers and the lids, between the inner periphery of the through holes and the outer peripheral surfaces of the ends of the heat transfer tubes, Side and above The contact portion between the down, and respectively brazed by the brazing material made of aluminum alloy.
[0017]
In particular, in the aluminum alloy heat exchanger of the present invention, a bracket is provided that is fixed to the lower end of each header so as to cover at least the lid that closes the lower end opening of each header. The bracket includes a cylindrical portion that fits in the lower end portion of each header, a small protrusion that protrudes from the inner peripheral surface of the cylindrical portion, a bottom plate portion that closes the lower end opening of the cylindrical portion, and one of the bottom plate portions. A locking projection protruding downward from the portion, and a communication hole for communicating the space surrounded by the cylindrical portion and the bottom plate portion to the outside. And the said bracket is being fixed to the lower end part of each said header by brazing the internal peripheral surface of the said cylindrical part, and the lower end part outer peripheral surface of each said header.
[0018]
[Action]
According to the aluminum alloy heat exchanger of the present invention configured as described above, the cylindrical portion constituting the bracket fixed to the lower end portion of each header in a state of covering the lid that closes the lower end opening of each header. A gap corresponding to the height of the small protrusions is formed between the inner peripheral surface of the head and the outer peripheral surface of the lower end portion of the header. From this gap, it is possible to allow flux to flow between the inner peripheral surface of the cylindrical portion constituting the bracket and the outer peripheral surface of the lower end portion of the header, and completely cover the brazed portion of the bracket with the flux. Can do. Furthermore, the brazing material flows into this gap during brazing. Therefore, it is possible to braze the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the lower end portion of the header with a sufficiently large area.
[0019]
In addition, when the volume of the gas existing in the space surrounded by the cylindrical portion and the bottom plate portion increases with the heating for brazing, the gas passes through the communication hole formed in the bracket. Discharged outside. Therefore, the gas does not push away the brazing material that has flowed into the gap, and micro-through holes are not formed in the brazing material.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show a first example of an embodiment of the present invention. The feature of this example is the structure of the portion where the lid 9a and the bracket 11a are attached to the lower end of each header 1a. Since the overall configuration and operation of the aluminum alloy heat exchanger are the same as those of the conventional structure shown in FIG. 6, the illustration and description thereof will be omitted, and the following description will focus on the features of the present invention. The lower end opening of the header 1a is closed with a lid 9a. The lid 9 a is formed by closing the upper end of the cylindrical portion 18 with a top plate portion 19 and forming an outward flange-like flange portion 20 on the lower end edge of the cylindrical portion 18. Such a lid 9a presses the cylindrical portion 18 into the lower end portion of the header 1a, and the header 1a with the upper surface of the flange portion 20 in contact with or close to the lower end edge of the header 1a. It is fitted and fixed to the lower end of the.
[0021]
The bracket 11a is externally fixed to the lower end of the header 1a so as to cover the lid 9a that closes the lower end opening of the header 1a. The bracket 11 a includes a cylindrical portion 12, a plurality of small protrusions 15, 15, a bottom plate portion 13, and a locking protrusion 14. Of these, the inner diameter R ₁₂ of the cylindrical portion 12 is slightly larger (eg, 0.6 mm or less) than the outer diameter D _1a of the lower end portion of the header 1a. Further, the plurality of small protrusions 15, 15 protrude from the inner peripheral surface of the cylindrical portion 12. These small protrusions 15 and 15 are provided at three or more locations (four locations in the illustrated example) on the inner peripheral surface of the cylindrical portion 12 at equal intervals in the circumferential direction and in the axial direction for each portion (see FIG. A plurality (two in the illustrated example, a total of eight) are provided apart from each other in the vertical direction of 1, 2, 4 and the front and back directions in FIG.
[0022]
Further, each member 9a, in free state 1a, the diameter D ₁₅ of the maximum inscribed circle of a plurality of small projections 15, 15 is slightly smaller than the outer diameter D _1a of the lower end portion of the header 1a (R ₁₂ > D _1a > D ₁₅ ). The operation for forming such small protrusions 15 is performed before the cylindrical portion 12 is formed. That is, the bracket 11a is formed by drawing a circular flat plate. Before the drawing, the small projections are formed on a portion of the flat plate corresponding to the inner peripheral surface of the cylindrical portion 12. 15 and 15 are formed in a protruding manner by pressing. When four or more small protrusions 15 are formed, it is not always necessary to provide them at equal intervals in the circumferential direction and at intervals in the axial direction as described above. Absent. For example, the small protrusions 15 and 15 may be formed at uneven intervals over the circumferential direction.
[0023]
The bottom plate portion 13 closes the lower end opening of the cylindrical portion 12. The locking protrusion 14 protrudes downward from the center of the bottom plate part 13. The locking projection 14 is formed in a bottomed cylindrical shape whose lower end is closed in a hemispherical shape and whose upper end is opened at the center of the bottom plate 13. Further, a communication hole 21 is formed in a part of the bottom plate 13 that is disengaged from the locking projection 14. The communication hole 21 allows the space 17 surrounded by the lid body 9a, the header 1a, the cylindrical portion 12 and the bottom plate portion 13 to communicate with the outside.
[0024]
The operation of closing the lower end opening of the header 1a with the lid 9a having the above-described shape and the bracket 11a having the above-described shape is performed as follows. First, as shown in FIG. 1, the cylindrical portion 18 constituting the lid 9a is pushed into the lower end portion of the header 1a, and the lower end portion of the header 1a is pushed into the cylindrical portion 12 constituting the bracket 11a. . As a result of this pushing operation, the tips of the plurality of small protrusions 15 and 15 are elastically pressed against the outer peripheral surface of the lower end portion of the header 1 a, and between the outer peripheral surface of the lower end portion and the inner peripheral surface of the cylindrical portion 12. A cylindrical gap 16 is formed. Is one-half of the difference between the outer diameter D _1a of the lower end portion of the inner diameter R ₁₂ and the header 1a of the cylindrical portion 12, the thickness T ₁₆ of the gap _{_{16 {= (R 12 -D 1a}} ) / 2 } Is a little (for example, 0.3 mm or less). Note that, due to the presence of the plurality of small protrusions 15, the bracket 11 a is not easily inclined with respect to the header 1 a during insertion work. Therefore, the thickness T ₁₆ of the gap 16 is substantially uniform over the entire circumference and the entire length.
[0025]
As described above, if the aluminum alloy heat exchanger is brazed in a state where the lid 9a is fitted into the lower end portion of the header 1a and the bracket 11a is fitted, the gap 16 is inserted into the gap 16 as will be described later. A sufficient amount of flux flows. The brazing material laminated on the inner circumferential surface of the header 1a brazes the inner circumferential surface and the outer circumferential surface of the cylindrical portion 18 constituting the lid body 9a, and is laminated on the outer circumferential surface of the header 1a. The brazing material flows into the gap 16. That is, since the thickness T ₁₆ of the gap 16 is small as described above, the flux and the (molten liquid) brazing material that have reached the upper end opening of the gap 16 are separated by the capillary phenomenon. It enters and spreads over the entire gap 16. Therefore, after the temperature is lowered and the brazing material is solidified, the inner peripheral surface of the cylindrical portion 12 and the outer peripheral surface of the lower end portion of the header 1a are brazed in a sufficiently wide area.
[0026]
In the present invention, the brazing material which is laminated on the surface of the header 1a and flows down the outer peripheral surface of the header 1a in a molten state is considered to be effectively used for brazing between the bracket 11a and the header 1a. Yes. Further, in the case of this example, the flux adhering to the outer peripheral surface of the header 1 a enters the gap 16 before the brazing material enters the gap 16. That is, when brazing the constituent members of the aluminum alloy heat exchanger, the constituent members are temporarily assembled as shown in FIG. 6 and then the flux is attached to the surface prior to heating. Among these, the flux adhering to the outer peripheral surface of the header 1a enters the gap 16 in a relatively initial stage of heating. As a result, a sufficient amount of flux can be supplied between the inner peripheral surface of the cylindrical portion 12 constituting the bracket 11a and the outer peripheral surface of the lower end portion of the header 1a, and the brazing performance of this portion can be improved. . Moreover, the vapor | steam of flux reaches also the fitting part of the said cover body 9a and the header 1a, and improves the brazing property of this fitting part.
[0027]
In addition, the brazing area between the outer peripheral surface of the cylindrical portion 18 constituting the lid body 9a and the inner peripheral surface of the lower end portion of the header 1a is not widened as compared with the conventional structure. However, in the case of the structure of the present invention, the cylindrical portion 12 of the bracket 11a holding the lid 9a toward the lower end portion of the header 1a is brazed with a sufficiently wide area to the header 1a. . Further, the brazing material and the flux flow into the gap between the lower end edge of the header 1a and the upper surface of the flange portion 20 of the lid body 9a, and the lower end edge and the upper surface are brazed. Therefore, it is possible to sufficiently ensure the pressure strength and airtightness of the lid 9a. In addition, by providing a plurality of small protrusions on the outer peripheral surface of the cylindrical portion 18 of the lid 9a, a cylindrical gap is formed between the outer peripheral surface of the cylindrical portion 18 and the inner peripheral surface of the lower end portion of the header 1a. If it forms, the brazing area of the outer peripheral surface of the said cylindrical part 18 and the lower end part inner peripheral surface of the header 1a can be enlarged.
[0028]
Further, in the case of the heat exchanger made of aluminum alloy according to the present invention, a communication hole 21 is formed in a part of the bottom plate portion 13 constituting the bracket 11a, and the communication hole 21 causes the inside of the space 17 to be inside. Gases such as existing air and flux vapor are discharged. Therefore, the gas does not push away the brazing material flowing into the gap 16 existing between the inner peripheral surface of the cylindrical portion 12 and the outer peripheral surface of the lower end portion of the header 1a. It will not be formed.
[0029]
If the lower end opening of the header 1a is closed with the lid 9a as described above, and the bracket 11a is fixed to the lower end of the header 1a while covering the lid 9a, as shown in FIG. The buffer material 22 made in an annular shape by an elastic material such as rubber or elastomer is fitted on the locking projection 14 of the bracket 11a. An aluminum alloy heat exchanger including the header 1a is formed by inserting a portion protruding from the lower surface of the cushioning material 22 at the lower half of the locking projection 14 into a locking hole provided on the vehicle body side. Is cushioned to the vehicle body.
[0030]
Next, FIG. 5 shows a second example of the embodiment of the present invention. In the case of this example, the lower end of the locking projection 14a constituting the bracket 11b is opened to form the locking projection 14a in a cylindrical shape, and the cylindrical portion 12 is formed on the inner portion of the locking projection 14a. And the bottom plate 13 have a function as a communication hole for communicating with the outside. Other configurations and operations are the same as those in the case of the first example described above, and thus redundant description is omitted.
[0031]
【The invention's effect】
Since the aluminum alloy heat exchanger of the present invention is configured and operates as described above, it is possible to sufficiently secure the pressure resistance of the aluminum alloy heat exchanger and improve the product yield. In addition, it is possible to prevent the formation of minute through holes in the brazing material filling the gap between the inner peripheral surface of the cylindrical portion constituting the bracket and the outer peripheral surface of the lower end portion of the header. It is possible to effectively prevent foreign objects from entering. For this reason, it is possible to prevent the lid body and the header facing the inner portion of the bracket from being corroded, and to ensure the durability of the aluminum alloy heat exchanger.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part showing a first example of an embodiment of the present invention.
FIG. 2 is a sectional view showing only a bracket taken out.
FIG. 3 is a bottom view of the same.
FIG. 4 is a front view of an essential part showing a state where a cushioning material is mounted after brazing the header and the bracket.
FIG. 5 is a view similar to FIG. 2, showing a second example of an embodiment of the present invention.
FIG. 6 is a perspective view showing an example of a conventionally known aluminum alloy heat exchanger.
FIG. 7 is a front view of a lower end portion of a header and a lid, showing a conventional structure.
FIG. 8 is a partial front view showing a state in which a conventional structure is assembled.
FIG. 9 is a front view of a bracket constituting the structure according to the previous invention.
FIG. 10 is a plan view of the same.
FIG. 11 is a partially cut front view showing the state before the brazing by combining the lower end portion of the header, the lid and the bracket, which constitutes the structure according to the present invention.
FIG. 12 is a partially cut front view showing the same state after brazing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a, 1b Header 2 Through-hole 3 Heat transfer pipe 4 Fin 5 Feed pipe 6 Take-out pipe 7 Core part 8 Side support 9, 9a Cover body 10 Fillet 11, 11a, 11b Bracket 12 Cylindrical part 13 Bottom plate part 14, 14a Locking protrusion 15 Small protrusion 16 Clearance 17 Space 18 Cylindrical portion 19 Top plate portion 20 Gutter portion 21 Communication hole 22 Buffer material

Claims

A pair of headers, each of which is made of an aluminum alloy and arranged in the vertical direction at intervals in the horizontal direction, a lid for closing the upper and lower end openings of each header, and the side surface of each header A plurality of through holes formed in portions facing each other, and a plurality of heat transfer tubes each formed into a flat tubular shape by an aluminum alloy, and inserted into each of the through holes without looseness at both ends. Each of which is formed by corrugating a thin plate made of an aluminum alloy, and includes fins sandwiched between adjacent heat transfer tubes, between the upper and lower ends of the pair of headers and the lids, Aluminum formed by brazing the abutting portions between the inner peripheral edge of each through hole and the outer peripheral surfaces of both end portions of each heat transfer tube, and the side surfaces of each heat transfer tube and the fins with an aluminum alloy brazing material, respectively. Together In the heat exchanger, a bracket is provided that is fixed to the lower end of each header so as to cover at least the lid that closes the lower end opening of each header. The bracket is provided at the lower end of each header. A cylindrical part that fits the inner part, a small protrusion that protrudes from the inner peripheral surface of the cylindrical part, a bottom plate part that closes the lower end opening of the cylindrical part, and a locking protrusion that protrudes downward from a part of the bottom plate part And a communication hole that communicates the space surrounded by the cylindrical portion and the bottom plate portion to the outside, and brazing the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the lower end portion of each header. An aluminum alloy heat exchanger characterized by being fixed to the lower end of the header.