JP3912889B2

JP3912889B2 - Tube for heat exchanger and manufacturing method thereof

Info

Publication number: JP3912889B2
Application number: JP08041998A
Authority: JP
Inventors: 浩隆門
Original assignee: Sanden Corp
Current assignee: Sanden Holdings Corp
Priority date: 1998-03-12
Filing date: 1998-03-12
Publication date: 2007-05-09
Anticipated expiration: 2018-03-12
Also published as: JPH11257886A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱交換器用チューブおよびその製造方法に関し、とくに、車両用熱交換器に好適な熱交換器用チューブおよびその製造方法、さらにはその熱交換器用チューブを備えた熱交換器に関する。
【０００２】
【従来の技術】
熱交換器用チューブ、より詳しくは、熱交換器において熱交換媒体を流通させる熱交換チューブは、従来、たとえば１枚の平板素材をロール加工によって幅方向に曲げ加工し、曲げ加工された素材の端部の先端同士を接合することによって作製されていた。このような製造方法では、たとえば図１５に示すように、上記先端同士が接合部１０２で突き合わせ接合された熱交換チューブ１０１が形成される。上記先端同士は、たとえば電解溶接によって接合される。
【０００３】
また、図１６に示すように、チューブ形成素材としての平板を複雑に折り曲げ加工し、チューブの幅方向中央部に接合部１１２を設けてこの部分でろう付けし、熱交換チューブ１１１を形成するようにした方法も知られている（特開平６−１２３５７１号公報）。
【０００４】
【発明が解決しようとする課題】
しかしながら、図１５に示したような製造方法においては、１枚のプレートをロール成形した電逢管を用いた場合、プレートの先端同士を接合部１０２で溶接接合しているため、接合面積が小さく接合強度が低いので、耐圧性能が低くなるおそれがある。また、長尺の素材にロール加工を施す必要があるため、チューブ１０１の加工費が高くなるという問題点がある。また、長尺物のロール加工では、加工後に所定寸法に切断することが多いので、不良品が生じやすかったり、後に修正加工が必要になったりし、この面からもコスト高になる傾向がある。さらに、プレートの先端同士を接合部１０２で接合しているだけなので、形成されるチューブ１０１の内寸、とくに、流路の高さを目標とする寸法に正確に決めることが難しく、該寸法にばらつきを生じるおそれがある。さらにまた、目標とする流路の高さが変更された場合には、その変更に正確に追従することが困難である。
【０００５】
また、図１６に示したようなチューブ製造方法においては次のような問題点がある。つまり、チューブとフィンとを交互に配置したコア部を有する熱交換器においては、通常、コア部を仮組した状態で炉中にて加熱ろう付けする方法が採用されている。しかし、図１６に示したように、熱交換チューブ１１１の幅方向中央部にチューブ形成のための接合部１１２を設ける構造では、ろう付け箇所にフラックスが十分に回らず、ろう付け不良が発生し、熱交換媒体の洩れに対する不良箇所が発生するおそれがある。
【０００６】
さらに、図１６に示したような、チューブ１１１の幅方向中央部にチューブ内を横断する方向に延びる接合部１１２を有する構造では、チューブ１１１の高い強度を確保することが可能であるが、図１５に示したような、チューブ１０１の幅方向中央部に何ら突き合わせ部等をもたない構造では、コア部本体をろう付けする際の、コア部本体とろう付け用治具（コア部のアセンブリを仮固定する治具）との熱膨張率の差に起因する締め付け力がコア部に加わり、チューブがつぶれたり、ろう付け不良箇所（洩れ発生箇所）等を生じたりするおそれがある。
【０００７】
そこで本発明の課題は、上記のような従来技術における問題点に着目し、熱交換器用チューブにおける接合箇所の接合強度が十分に高く、十分に高い耐圧性を確保することが可能で、チューブの内寸等の変更にも容易にかつ正確に対応でき、かつ、ろう付けの際にも必要部位にフラックスを十分に付与可能で、しかも、容易にチューブの幅方向中央部の補強構造を採ることが可能な、熱交換器用チューブおよびその製造方法を提供することにある。
【０００８】
【課題を解決するための手段】
上記課題を解決するために、本発明の熱交換器用チューブは、互いに対向し、間に熱交換媒体用流路を形成する２つの平板状部と、両平板状部の一方の幅方向端部において両平板状部を一体的に接続する曲げ加工部と、少なくとも一方の平板状部の他方の幅方向端部に形成され、該端部を複数回互いに逆方向に折り返すように曲げ加工された折り返し部とを有し、該折り返し部と、他方の平板状部の対応する端部とが互いに接合されており、前記折り返し部が、その最初の折り返し片部が前記一方の平板状部の他方の幅方向端部のチューブ内面に面接触し、後続の折り返し片部がその前の折り返し片部に面接触するように折り返されており、チューブ内寸が、折り返し片部の厚み×折り返し片部の数に相当する寸法に決められていることを特徴とするものからなる。
【０００９】
また、本発明に係る熱交換器用チューブは、互いに対向し、間に熱交換媒体用流路を形成する２つの平板状部と、少なくとも一方の平板状部の幅方向両端部において各端部をそれぞれ複数回互いに逆方向に折り返すように曲げ加工された折り返し部とを有し、該折り返し部と、他方の平板状部の対応する端部とが互いに接合されており、前記折り返し部が、その最初の折り返し片部が前記一方の平板状部の幅方向各端部のチューブ内面に面接触し、後続の折り返し片部がその前の折り返し片部に面接触するように折り返されており、チューブ内寸が、折り返し片部の厚み×折り返し片部の数に相当する寸法に決められていることを特徴とするものからなる。
【００１０】
このような熱交換器用チューブにおいては、前記折り返し部が、その最初の折り返し片部が前記平板状部のチューブ内面に面接触し、後続の折り返し片部がその前の折り返し片部に面接触するように折り返されており、このような折り返し部は、プレス加工により形成できる。
【００１１】
また、一方の平板状部の幅方向中央部に、該一方の平板状部自身の折り曲げ加工によって、他方の平板状部に向かって実質的に他方の平板状部に当接する位置まで突出する突き合わせ部が形成されている構造とすることもできる。また、上記折り返し部は、他方の平板状部の対応する端部にろう付けによって接合することができる。
【００１２】
このような熱交換器用チューブには、さらに次のような構成を付加してもよい。たとえば、前記平板状部間にインナーフィンが設けられている構造とすることができる。
【００１３】
また、前記平板状部の少なくとも一方に、チューブ内方に向かって突出する複数の突出部が設けられ、互いに対向する突出部同士が、または突出部と該突出部が設けられた平板状部に対向する平板状部の内面とが、互いに突き合わされている構造とすることができる。また、前記平板状部は、その幅方向の略中央部が頂点となるようにチューブ外方に向けて膨出するように形成し、チューブの耐圧性を向上する構造とすることもできる。
【００１４】
さらに、前記平板状部の各対向面上に、互いに交差する方向に延びる溝が設けられている構造とすることができる。
【００１５】
本発明に係る熱交換器は、上記のような熱交換器用チューブの構造を有するものである。熱交換器のタイプはとくに限定されず、たとえば、チューブとフィンとを交互に配置したタイプの熱交換器に本発明を適用できる。
【００１６】
また、本発明に係る熱交換器用チューブの製造方法は、（ａ）所定幅を有する１枚の平板の幅方向の少なくとも一端部に、該端部を複数回互いに逆方向に折り返すように曲げ加工して折り返し部を形成するとともに、その最初の折り返し片部が前記一端部に面接触し、後続の折り返し片部がその前の折り返し片部に面接触するように折り返し、（ｂ）該平板の幅方向中央部を前記折り返し部が内側となるように曲げ加工して、間に熱交換媒体用流路を形成する２つの平板状部を形成し、（ｃ）少なくとも一方の平板状部の端部に形成された前記折り返し部を、他方の平板状部の対応する端部に接合するとともに、チューブ内寸を、前記折り返し片部の厚み×前記折り返し片部の数に相当する寸法に決めることを特徴とする方法からなる。
【００１７】
さらに、本発明に係る熱交換器用チューブの製造方法は、（ａ）それぞれ所定幅を有する２枚の平板のうち少なくとも一方の平板の幅方向両端部に、各端部をそれぞれ複数回互いに逆方向に折り返すように曲げ加工して折り返し部を形成するとともに、その最初の折り返し片部が前記一方の平板の各端部に面接触し、後続の折り返し片部がその前の折り返し片部に面接触するように折り返し、（ｂ）幅方向両端部に折り返し部が形成された平板の折り返し部と、他方の平板の対応する端部とを互いに接合するとともに、チューブ内寸を、前記折り返し片部の厚み×前記折り返し片部の数に相当する寸法に決めることを特徴とする方法からなる。
【００１８】
このような製造方法においては、前記折り返し部を、その最初の折り返し片部が前記平板に面接触し、後続の折り返し片部がその前の折り返し片部に面接触するように折り返すが、このような折り返し部は、プレス加工により形成することができる。
【００１９】
また、前記折り返し部の形成の前または後に、一方の平板の幅方向中央部に、該一方の平板自身を折り曲げ加工することにより、チューブ完成後の状態において他方の平板に向かって実質的に他方の平板に当接する位置まで突出する突き合わせ部を形成することができる。上記折り返し部を、他方の平板の対応する端部にろう付けによって接合することができる。
【００２０】
また、この製造方法においても、前記チューブ形成用平板間にインナーフィンを介装するステップを加えることができる。また、前記平板に、チューブ形成の際にチューブ内方に向かって突出する複数の突出部を形成するようにしてもよい。
【００２１】
さらに、チューブ形成の際に互いに対向する面となる前記各平板の面上に、チューブ形成時に互いに交差する方向に延びる溝を刻設するようにしてもよい。
【００２２】
上記のような熱交換器用チューブおよびその製造方法においては、少なくとも一方の平板状部の幅方向端部に形成される折り返し部は、たとえばプレス加工によって成形可能である。したがって、加工費が安く、先に所定寸法の幅に切断したものをプレス加工するので、加工不良等が発生せず、修正加工も不要である。その結果、製造コストが大幅に低減される。
【００２３】
また、従来のように先端同士を突き合わせて接合するのではなく、折り返し部を、対応する他方の平板状部の幅方向端部（この部分も折り返し部に形成されていてもよい）に面接触状態にて接合できるので、十分に広い接合面積となり、高い接合強度が確保され、高い耐圧性を実現できる。そして、折り返し部は、複数回互いに逆方向に折り返すように曲げ加工されて、折り返し片部が面接触状態で重ねられるように形成されるので、折り返し部自身の高い強度が確保されるとともに、上記の如く面接触状態での接合面により高い接合強度が確保され、チューブ全体として高い耐圧性を実現できる。
【００２４】
さらに、折り返し部は、複数回互いに逆方向に折り返すように曲げ加工されて形成されるから、その折り返し回数によって、折り返し部の厚さを規定できる。すなわち、折り返し部の厚さ、とくにチューブの内寸決定に寄与する折り返し部の厚さは、折り返し回数、つまり、折り返し片部の積層数によって決めることができ、設計の自由度が大幅に増大する。この厚さは、折り返し片部同士、および、最初の折り返し片とその平板状部のチューブ内面形成面とが、それぞれ面接触されることにより、正確に、折り返し片の厚み×折り返し片の数に相当する寸法に決められる。したがって、形成されるチューブの内寸も、目標とする寸法に正確に決められることになり、高精度のチューブが得られる。
【００２５】
また、突き合わせ部を設ける場合にも、該突き合わせ部は平板状部自身を折り曲げ加工することによって形成できるので、チューブの幅方向中央部にはろう付け等を要求する部位は発生せず、フラックスの塗布不足、それに起因するろう付け不良、さらには洩れに対する不良箇所等が発生するおそれを除去できる。
【００２６】
突き合わせ部を設ければ、上記のような効果を保ちつつ、さらに、チューブをその幅方向中央部において補強できるので、コア部等をろう付けする際に、チューブの変形や、コア部とろう付け用治具との熱膨張率の差に起因するろう付け不良、洩れ不良箇所等の発生を防止することが可能となる。
【００２７】
【発明の実施の形態】
以下に、本発明の望ましい実施の形態を、図面を参照して説明する。
図１は、本発明の一実施態様に係る熱交換器１を示している。熱交換器１は、入出口側の２つのタンク部２、３と、タンク部２、３間に設けられ両タンク部２、３を連通する、内部に熱交換媒体流通用の流路を有する複数の熱交換チューブ４と、コルゲートフィン５とを有しており、熱交換チューブ４とフィン５とが交互に配置されている。本実施態様では、熱交換チューブ４とフィン５とを有するコア部６の最外層には、サイドプレート７、８が設けられている。また、一方のサイドプレート８の外面側および一方のタンク部２の側面には、熱交換器１取付用のブラケット９、１０が接合されている。タンク部２、３には、それぞれ、配管あるいは他の機器を接続するためのフィッティング１１、１２が設けられている。
【００２８】
このような熱交換器１の熱交換チューブ４は、たとえば、図２〜図５に示すように構成される（熱交換チューブ２１ａ、２１ｂ、２１ｃ、３１、４１ａ、４１ｂ、４１ｃ、５１）。
図２（Ａ）に示す態様の熱交換チューブ２１ａは、間隔をもって互いに対向し、間に熱交換媒体用流路２２を形成する２つの平板状部２３ａ、２３ｂと、両平板状部２３ａ、２３ｂの一方の幅方向端部において両平板状部２３ａ、２３ｂを一体的に接続する曲げ加工部２４と、一方の平板状部２３ａの他方の幅方向端部に形成され、該端部を複数回（本実施態様では２回）互いに逆方向に折り返すように曲げ加工された折り返し部２５ａとを有し、該折り返し部２５ａと、他方の平板状部２３ｂの対応する端部２５ｂ（本実施態様では該端部には折り返し部は形成されていない）とが互いに接合されている（接合部２６）。折り返し部２５ａにおいては、その最初の折り返し片部２７ａが平板状部２３ａのチューブ内面に面接触により密着し、後続の折り返し片部２７ｂがその前の折り返し片部２７ａに面接触により密着するように折り返されている。そして、この折り返し部２５ａの折り返し片部２７ｂが、他方の平板状部２３ｂの対応する端部２５ｂに面接触により密着するようにろう付けによって接合されている。このような折り返し部２５ａは、プレス加工により形成されている。
【００２９】
図２（Ｂ）に示す態様の熱交換チューブ２１ｂでは、他方の平板状部２３ｂの対応する一端部に、１回だけ折り返された折り返し部２８が形成され、折り返し部２５ａと折り返し部２８が面接触により密着するようにろう付けによって接合されている。図２（Ｃ）に示す態様の熱交換チューブ２１ｃでは、両平板状部２３ａ、２３ｂの互いに対応する端部に、それぞれ、２回折り返した折り返し部２５ａが形成され、折り返し部２５ａ同士が面接触により密着するようにろう付けによって接合されている。このように、折り返し部の折り返し回数、他方の平板状部２３ｂの対応する端部の形態は自由に設定でき、チューブの内寸（流路高さ）は、両平板状部２３ａ、２３ｂ間に介在する折り返し片の数によって正確に目標とする寸法に決められる。もちろん、図に示した以外の内寸も可能であり、目標とする寸法に応じて、両平板状部２３ａ、２３ｂ間に介在する折り返し片の数、折り返し部における折り返し回数を決めればよい。
【００３０】
図３に示す態様の熱交換チューブ３１は、上記熱交換チューブ２１ａ同様の、熱交換媒体用流路３２を形成する２つの平板状部３３ａ、３３ｂと、両平板状部３３ａ、３３ｂを一体的に接続する曲げ加工部３４と、一方の平板状部３３ａの他方の幅方向端部に形成され、該端部を複数回（本実施態様では２回）互いに逆方向に折り返すように曲げ加工された折り返し部３５ａとを有し、該折り返し部３５ａと、他方の平板状部３３ｂの対応する端部３５ｂ（本実施態様では該端部には折り返し部は形成されていない）とが互いに接合されている（接合部３６）。そして、本実施態様では、一方の平板状部３３ｂの幅方向中央部に、平板状部３３ｂ自身を折り曲げ加工することによって、他方の平板状部３３ａに向かって実質的に平板状部３３ａの内面に当接する位置まで突出する突き合わせ部３７が形成されている。この突き合わせ部３７の先端面は、平板状部３３ａの内面に接合されていてもよく、単に当接しているだけでもよい。前記熱交換チューブ２１ｂ、２１ｃについても同様の構成を採ることができる。
【００３１】
図４（Ａ）に示す態様の熱交換チューブ４１ａは、間隔をもって互いに対向し、間に熱交換媒体用流路４２を形成する２つの平板状部（平板）４３ａ、４３ｂと、一方の平板状部４３ａの幅方向両端部において各端部をそれぞれ複数回折り返すように曲げ加工された折り返し部４４ａ、４４ｂを有し、該折り返し部４４ａ、４４ｂが、他方の平板４３ｂの対応する幅方向両端部４５ａ、４５ｂにろう付けによって接合されている（接合部４６ａ、４６ｂ）。折り返し部４４ａ、４４ｂにおいては、その最初の折り返し片部４７ａが平板状部４３ａのチューブ内面に面接触により密着し、後続の折り返し片部４７ｂがその前の折り返し片部４７ａに面接触により密着するように折り返されている。そして、この折り返し部４４ａ、４４ｂの折り返し片部４７ｂが、他方の平板状部４３ｂの対応する端部４５ａ、４５ｂに面接触により密着するようにろう付けによって接合されている。このような折り返し部４４ａ、４４ｂは、プレス加工により形成されている。
【００３２】
図４（Ｂ）に示す態様の熱交換チューブ４１ｂでは、他方の平板状部４３ｂの対応する両端部に、１回だけ折り返された折り返し部４８が形成され、折り返し部４４ａ、４４ｂとそれらに対応する折り返し部４８が面接触により密着するようにろう付けによって接合されている。図４（Ｃ）に示す態様の熱交換チューブ４１ｃでは、両平板状部４３ａ、４３ｂの互いに対応する両端部に、それぞれ、２回折り返した折り返し部４４ａ、４４ｂが形成され、対応する折り返し部同士が面接触により密着するようにろう付けによって接合されている。このように、チューブ形成前には互いに分離されている態様においても、折り返し部の折り返し回数、他方の平板状部４３ｂの対応する端部の形態は自由に設定でき、チューブの内寸（流路高さ）は、両平板状部４３ａ、４３ｂ間に介在する折り返し片の数によって正確に目標とする寸法に決められる。もちろん、この態様においても、図に示した以外の内寸も可能であり、目標とする寸法に応じて、両平板状部４３ａ、４３ｂ間に介在する折り返し片の数、折り返し部における折り返し回数を決めればよい。
【００３３】
図５に示す態様の熱交換チューブ５１は、図４（Ａ）に示したと同様の、熱交換媒体用流路５２を形成する２つの平板状部５３ａ、５３ｂと、一方の平板状部５３ａの幅方向両端部において各端部をそれぞれ複数回折り返すように曲げ加工された折り返し部５４ａ、５４ｂを有し、該折り返し部５４ａ、５４ｂが、他方の平板５３ｂの対応する幅方向両端部５５ａ、５５ｂにろう付けによって接合されている（接合部５６ａ、５６ｂ）。そして、本実施態様では、一方の平板状部５３ｂの幅方向中央部に、平板状部５３ｂ自身を折り曲げ加工することによって、他方の平板状部５３ａに向かって実質的に平板状部５３ａの内面に当接する位置まで突出する突き合わせ部５７が形成されている。この突き合わせ部５７の先端面は、平板状部５３ａの内面に接合されていてもよく、単に当接しているだけでもよい。
【００３４】
図２ないし図５に示したような各熱交換チューブは、一般に、フィン、ヘッダーパイプ等の他の熱交換器用部品と仮組みされ、炉中ろう付けによって接合され、熱交換器として製造される。また、チューブ内部には、後述の如く、耐圧性能向上、伝熱性能向上を目的にインナーフィンが挿入されることがある。つまり、チューブ内外両面にフィンが接合されることがある。このような場合、ろう付け接合のために、通常、フィンかチューブシェルのいずれかにろう材が張り付けられたクラッド材を用いる。この場合、チューブシェルの両面にろう材が張り付けられたクラッド材を用いればチューブシェルが液密にろう付けされることは言うまでもないが、フィンにはろう材をクラッドしないベア材を用いることが可能である。また、チューブシェルのみのろう付けを考えた場合には、内外両面にろう材をクラッドした素材、片面にのみクラッドした素材を用いる方法、あるいはこれら素材を組み合わせて用いる方法を、適宜選択できる。
【００３５】
図２ないし図５に示した熱交換チューブ２１ａ、３１、４１ａ、５１は、それぞれ、図６ないし図９に示すような方法によって製造される。熱交換チューブ２１ｂ、２１ｃ、４１ｂ、４１ｃについても同様の方法によって製造できる。
【００３６】
図６は、図２（Ａ）に示した熱交換チューブ２１ａを製造する方法を示している。まず、チューブ形成用素材としての広幅の平板６１から、適当なカッター装置６２等による切断により、所定幅を有する平板６３を形成する。次に、所定幅を有する１枚の平板６３の幅方向一端部を、２回折り返すように曲げ加工し、該端部に折り返し部２５ａを形成する。
【００３７】
次に、この平板６３の幅方向中央部を図６の上面側に曲げ加工して、間隔をもって互いに対向し、間に熱交換媒体用流路２２を形成する２つの平板状部２３ａ、２３ｂを形成する。そして、平板状部２３ａの端部の折り返し部２５ａと、平板状部２３ｂの端部２５ｂを互いに接合する（接合部２６）ことによって、図２に示した熱交換チューブ２１ａが完成する。
【００３８】
図７は、図３に示した熱交換チューブ３１の製造方法を示している。まず、素材としての広幅の平板６１から、カッター装置６２等による切断により、図６に示したよりも若干大きい所定幅を有する平板７１を形成する。次に、この１枚の平板７１の所定位置に、突き合わせ部３７を折り曲げ加工によって形成する。そして、この平板７１の幅方向一端部を、突き合わせ部３７と同じ面側に２回折り返すように曲げ加工し、該端部に折り返し部３５ａを形成する。次に、この平板７１の幅方向中央部を突き合わせ部３７と同じ面側に曲げ加工して、間隔をもって互いに対向し、間に熱交換媒体用流路３２を形成する２つの平板状部３３ａ、３３ｂを形成する。そして、平板状部３３ａの端部の折り返し部３５ａと、平板状部３３ｂの端部３５ｂを互いに接合する（接合部３６）ことによって、図３に示した熱交換チューブ３１が完成する。
【００３９】
図８は、図４（Ａ）に示した熱交換チューブ４１ａの製造方法を示している。まず、素材としての広幅の平板６１から、カッター装置６２等による切断により、異なる幅の２枚の平板８１ａ、８１ｂを形成する。次に、このうち１枚の平板８１ａの両端部に、それぞれ、折り返し部４４ａ、４４ｂを曲げ加工によって形成する。両平板８１ａ、８１ｂを、両平板状部４３ａ、４３ｂとして、折り返し部４４ａ、４４ｂとそれらに対応する平板状部の両端部４５ａ、４５ｂが互いに対向するように位置決めし、互いに接合する（接合部４６ａ、４６ｂ）ことによって、図４に示した熱交換チューブ４１ａが完成する。
【００４０】
図９は、図５に示した熱交換チューブ５１の製造方法を示している。まず、素材としての広幅の平板６１から、カッター装置６２による切断により、２枚の平板９１ａ、９１ｂを形成する。次に、一方の平板９１ｂの幅方向中央部に、折り曲げ加工によって突き合わせ部５７を形成する。他方の平板９１ａの両端部に、各端部をそれぞれ複数回折り返すように曲げ加工して折り返し部５４ａ、５４ｂを形成する。該折り返し部５４ａ、５４ｂを、他方の平板９１ｂの対応する幅方向両端部５５ａ、５５ｂにろう付けによって接合する（接合部５６ａ、５６ｂ）ことによって、図５に示した熱交換チューブ５１が完成する。
【００４１】
上記のように製造され、構成された熱交換器用チューブにおいては、従来のように先端同士を突き合わせて接合するのではなく、少なくとも一方の平板状部の幅方向端部に形成される折り返し部を対応する他方の平板状部の幅方向端部に面接触状態にて接合できるので、十分に広い接合面積となり、高い接合強度が確保でき、高い耐圧性を実現できる。そして、折り返し部は、複数回互いに逆方向に折り返すように曲げ加工されて、折り返し片部が面接触状態で重ねられるように形成されるので、折り返し部自身についても高い強度が確保されるとともに、上記の如く面接触状態での接合面により高い接合強度が確保され、チューブ全体として一層高い耐圧性を実現できる。
【００４２】
また、平板状部の幅方向端部に形成される折り返し部は、プレス加工によって成形できる。したがって、従来のロール加工が不要となり、加工費、ひいてはチューブ、さらには熱交換器の製造コストの大幅な低減が可能となる。また、ロール加工を施さないので、加工後の修正等も不要となり、不良品の発生率も大幅に低下でき、製造の容易化とともに、一層の製造コスト低減が可能となる。
【００４３】
また、折り返し部は、複数回互いに逆方向に折り返すように曲げ加工されて形成され、折り返し回数によって、チューブの内寸を実質的に自由に、かつ、正確に決めることができるから、設計の自由度が大幅に増大する。このチューブの内寸は、折り返し片部同士、および、最初の折り返し片とその平板状部のチューブ内面形成面とが、それぞれ面接触されることにより、より正確に、折り返し片の厚み×折り返し片の数に相当する寸法に決められる。したがって、形成されるチューブの内寸も、目標とする寸法に高精度で正確に決められることになり、所望の内寸のチューブが容易に得られる。
【００４４】
また、チューブの幅方向中央部には、ろう付け部は存在しないので、フラックスの回り不良等のおそれもない。また、チューブ補強のための突き合わせ部も、一方の平板状部自身の折り曲げ加工によって容易に形成できるので、強度の高いチューブ構造を容易に実現できる。
【００４５】
しかも、この突き合わせ部は基本的に他の部位からフラックスを流動させたり、フラックスを外部から塗布したりする必要のない部位であるから、図１５に示した構造におけるような、フラックスの回り不良の発生もない。したがって、ろう付け不良箇所の発生を容易に防止できる。
【００４６】
さらに、突き合わせ部を備えた構造にあっては、コア部６を治具で固定してろう付けする際にも、コア部とろう付け用治具との熱膨張率の差に起因して発生する変形力や位置ずれ力に対し、高い抗力を発揮できる。その結果、チューブの変形やろう付け不良箇所の発生を効果的に防止することができる。したがって、確実なろう付けが施された、洩れ不安のない、高性能の熱交換器を製造できる。
【００４７】
なお、上記製造方法の説明においては、突き合わせ部は端部折り返し部形成前に形成するようにしたが、端部折り返し部形成後に形成することも可能である。
【００４８】
また、前述の図２ないし図５に示した構成を有する熱交換器用チューブには、さらに次のような構成を付加することができる。以下の付加構成は、図２（Ａ）に示した構造の熱交換器用チューブについて説明するが、図３ないし図５に示した構造のチューブにも同様に適用することができる。
【００４９】
まず、図１０に示す熱交換チューブ２０１においては、チューブ２０１の平板状部２０２ａ、２０２ｂ間に形成された熱交換媒体用流路２０３に、波形のインナーフィン２０４が設けられ、インナーフィン２０４によって流路２０３が複数に分割されている。インナーフィン２０４の構造はとくに限定されず、波形以外のものも適用可能である。このようなインナーフィン２０４は、チューブ２０１を形成した後に挿入することができるし、インナーフィン２０４を配置した後に、チューブ２０１を折り曲げ、形成することもできる。
【００５０】
このような構成を有する熱交換チューブ２０１では、前述の図２（Ａ）について説明した作用、効果に加え、チューブ２０１の温度の均一化がはかられ、チューブ２０１による熱交換性能がより向上される。
【００５１】
また、図１１（Ａ）、（Ｂ）に示す熱交換チューブ２１１においては、チューブ２１１の両平板状部２１２ａ、２１２ｂに、チューブ内方に向かって突出する複数の突出部２１３が設けられ、突出部２１３同士は互いに対向配置されて先端面同士が当接されている。各突出部２１３は、チューブ形成前の平板素材をエンボス加工することにより容易に形成でき、形成後チューブ加工すればよい。
【００５２】
このような構成を有する熱交換チューブ２１１では、前述の図２（Ａ）について説明した作用、効果に加え、突出部２１３によって流路内を流通する熱交換媒体のミキシング効果が向上するので、温度の均一化、熱伝達の促進がはかられ、チューブ２１１による熱交換性能がより向上される。
【００５３】
なお、突出部２１３は一方の平板状部のみに設け、その突出部２１３の先端面を対向する他方の平板状部の内面に当接させるようにしてもよい。
【００５４】
さらに、図１２（Ａ）、（Ｂ）に示す熱交換チューブ２２１においては、平板状部２２２ａ、２２２ｂの各対向面上に、互いに交差する方向に斜めに延びる溝２２３ａ、２２３ｂがそれぞれ複数条刻設されている。この溝２２３ａ、２２３ｂは、たとえば図１３に示すように、チューブ２２１に形成する前の平板状素材２２４に、チューブ２２１に形成した際に上記のように互いに交差する方向に延びるように溝２２３ａ、２２３ｂを刻設し、その後にチューブ２２１に加工すればよい。
【００５５】
このような構成を有する熱交換チューブ２２１では、前述の図２（Ａ）について説明した作用、効果に加え、交差する溝２２３ａ、２２３ｂによって流路内を流通する熱交換媒体のミキシング効果が向上するので、温度の均一化、熱伝達の促進がはかられ、チューブ２２１による熱交換性能がより向上される。
【００５６】
さらに、本発明においては、たとえば図１４に示すように、平板状部２３２ａ、２３２ｂを、その幅方向の略中央部が頂点となるようにチューブ外方に向けて膨出する形状としたチューブ２３１に構成してもよい。このように構成することにより、チューブ２３１の耐圧性を向上できる。この膨出量δは、ごく僅かな量でよい。
【００５７】
なお、本発明に係る熱交換器用チューブは、図１に示したようなタイプの熱交換器に限定されず、あらゆるタイプの熱交換器に適用可能である。とくに車両用の熱交換器、たとえばラジエータや空調装置用のヒータ、凝縮器、蒸発器等、さらにはインタークーラ等に好適である。
【００５８】
【発明の効果】
以上説明したように、本発明の熱交換器用チューブおよびその製造方法によるときは、チューブの少なくとも一方の平板状部の端部にプレス加工等によって複数回折り返した折り返し部を形成し、該折り返し部を他方の平板状部の対応する端部にろう付け等によって接合するようにしたので、十分に広い接合面積を確保して、高い接合強度、高い耐圧性能を得ることができる。また、折り返し部の折り返し回数によってチューブの内寸を実質的に自由にかつ正確に所望の寸法に設定でき、設計の自由度の高い熱交換器用チューブを容易にかつ安価に製造できる。さらに、チューブ幅方向中央部にろう付け部を有しないので、フラックス回り不良によるろう付け不良等の不安を除去でき、所望の接合が確実に行われたチューブを得ることができる。
【００５９】
また、一方の平板状部に折り曲げ加工によって突き合わせ部を形成しておけば、チューブの耐変形強度を大幅に高めることができ、熱交換器のコア部ろう付けの際にも、該コア部とろう付け用治具との熱膨張率の差に起因するチューブの潰れ等によるろう付け不良、洩れ不良箇所の発生を防止することができる。
【図面の簡単な説明】
【図１】本発明の一実施態様に係る熱交換器の正面図である。
【図２】本発明の一実施態様に係る各熱交換器用チューブの部分斜視図である。
【図３】本発明の別の実施態様に係る熱交換器用チューブの部分斜視図である。
【図４】本発明のさらに別の実施態様に係る各熱交換器用チューブの部分斜視図である。
【図５】本発明のさらに別の実施態様に係る熱交換器用チューブの部分斜視図である。
【図６】図２（Ａ）の熱交換器用チューブの製造方法を示す工程フロー図である。
【図７】図３の熱交換器用チューブの製造方法を示す工程フロー図である。
【図８】図４（Ａ）の熱交換器用チューブの製造方法を示す工程フロー図である。
【図９】図５の熱交換器用チューブの製造方法を示す工程フロー図である。
【図１０】図２（Ａ）に示した熱交換器用チューブの変形例を示すチューブの部分斜視図である。
【図１１】（Ａ）は、図２（Ａ）に示した熱交換器用チューブの別の変形例を示すチューブの部分斜視図であり、（Ｂ）は、（Ａ）のチューブのＡ−Ａ線に沿う断面図である。
【図１２】（Ａ）は、図２（Ａ）に示した熱交換器用チューブのさらに別の変形例を示すチューブの部分斜視図であり、（Ｂ）は、（Ａ）のチューブの拡大正面図である。
【図１３】図１２に示したチューブのチューブ加工前の平板状素材の部分平面図である。
【図１４】図２（Ａ）に示した熱交換器用チューブの変形例を示すチューブの断面図である。
【図１５】従来の熱交換器用チューブの部分斜視図である。
【図１６】従来の別の熱交換器用チューブの部分斜視図である。
【符号の説明】
１熱交換器
２、３タンク部
４チューブ
５フィン
６コア部
７、８サイドプレート
９、１０ブラケット
１１、１２フィッティング
２１ａ、２１ｂ、２１ｃ、３１、４１ａ、４１ｂ、４１ｃ、５１、２０１、２１１、２２１、２３１熱交換チューブ
２２、３２、４２、５２、２０３熱交換媒体用流路
２３ａ、２３ｂ、３３ａ、３３ｂ、４３ａ、４３ｂ、５３ａ、５３ｂ、２０２ａ、２０２ｂ、２１２ａ、２１２ｂ、２２２ａ、２２２ｂ平板状部（平板）
２４、３４曲げ加工部
２５ａ、２８、３５ａ、４４ａ、４４ｂ、４８、５４ａ、５４ｂ折り返し部
２５ｂ、３５ｂ、４５ａ、４５ｂ、５５ａ、５５ｂ対応する平板状部の端部
２６、３６、４６ａ、４６ｂ、５６ａ、５６ｂ接合部
２７ａ、２７ｂ、４７ａ、４７ｂ折り返し片部
３７、５７突き合わせ部
６１素材としての広幅の平板
６２カッター装置
６３、７１、８１ａ、８１ｂ、９１ａ、９１ｂ所定幅に切断された平板
２０４インナーフィン
２１３突出部
２２３ａ、２２３ｂ溝
２２４平板状素材
２３２ａ、２３２ｂ膨出加工された平板状部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchanger tube and a manufacturing method thereof, and more particularly to a heat exchanger tube suitable for a vehicle heat exchanger, a manufacturing method thereof, and a heat exchanger provided with the heat exchanger tube.
[0002]
[Prior art]
A heat exchanger tube, more specifically, a heat exchange tube for circulating a heat exchange medium in a heat exchanger, has been conventionally bent by, for example, a single flat plate material in the width direction by roll processing, and ends of the bent material. It was produced by joining the tips of the parts. In such a manufacturing method, for example, as shown in FIG. 15, a heat exchange tube 101 is formed in which the tips are butt-joined at a joint 102. The tips are joined together by, for example, electrolytic welding.
[0003]
In addition, as shown in FIG. 16, a flat plate as a tube forming material is complicatedly bent, and a joining portion 112 is provided at the central portion in the width direction of the tube and brazed at this portion, so that the heat exchange tube 111 is formed. A method is also known (Japanese Patent Laid-Open No. 6-123571).
[0004]
[Problems to be solved by the invention]
However, in the manufacturing method as shown in FIG. 15, when an electric steel tube in which one plate is roll-formed is used, since the tips of the plates are welded together by the joint portion 102, the joining area is small. Since the bonding strength is low, the pressure resistance may be lowered. Moreover, since it is necessary to roll a long material, there exists a problem that the processing cost of the tube 101 becomes high. Further, in roll processing of a long object, since it is often cut into a predetermined dimension after processing, defective products are likely to be generated, or correction processing is required later, and this also tends to increase costs. . Furthermore, since the tips of the plates are merely joined together by the joint portion 102, it is difficult to accurately determine the inner dimension of the tube 101 to be formed, particularly the height of the flow path, as a target dimension. There may be variations. Furthermore, when the target channel height is changed, it is difficult to accurately follow the change.
[0005]
Further, the tube manufacturing method as shown in FIG. 16 has the following problems. That is, in a heat exchanger having a core portion in which tubes and fins are alternately arranged, a method of heat brazing in a furnace with the core portion temporarily assembled is usually employed. However, as shown in FIG. 16, in the structure in which the joining portion 112 for forming the tube is provided in the center portion in the width direction of the heat exchange tube 111, the flux does not sufficiently rotate at the brazing location, and the brazing failure occurs. There is a possibility that a defective part with respect to leakage of the heat exchange medium may occur.
[0006]
Furthermore, in the structure having the joint portion 112 extending in the direction transverse to the inside of the tube 111 at the center portion in the width direction of the tube 111 as shown in FIG. 16, it is possible to ensure high strength of the tube 111. In the structure having no butted portion or the like at the center in the width direction of the tube 101 as shown in FIG. 15, the core body and the brazing jig (the assembly of the core section) when brazing the core body. Tightening force due to the difference in coefficient of thermal expansion from the jig (temporarily fixing) may be applied to the core portion, and the tube may be crushed or a brazed defective part (leakage occurrence part) may occur.
[0007]
Therefore, the object of the present invention is to pay attention to the problems in the prior art as described above, and the joint strength of the joint portion in the heat exchanger tube is sufficiently high, and it is possible to ensure a sufficiently high pressure resistance. Can easily and accurately respond to changes in internal dimensions, etc., and can sufficiently apply flux to the required part even during brazing, and easily adopt a reinforcing structure at the center in the width direction of the tube An object of the present invention is to provide a heat exchanger tube and a manufacturing method thereof.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, a heat exchanger tube according to the present invention has two flat plate portions that face each other and form a heat exchange medium flow path therebetween, and one widthwise end portion of both flat plate portions. Formed at the other end in the width direction of at least one of the flat plate portions, and the end portions are bent so as to be folded back and forth in a plurality of opposite directions. A folded portion, and the folded portion and the corresponding end portion of the other flat plate portion are joined to each other. The first folded piece is in surface contact with the inner surface of the tube at the other widthwise end of the one flat plate portion, and the subsequent folded piece is in surface contact with the preceding folded piece. The tube inner dimension is determined to be a dimension corresponding to the thickness of the folded piece portion × the number of the folded piece portions. It consists of what is characterized by this.
[0009]
Further, the heat exchanger tube according to the present invention has two flat plate portions that face each other and form a heat exchange medium flow path therebetween, and each end portion at the width direction both ends of at least one flat plate portion. Each of the folded portions is bent so as to be folded in the opposite direction, and the folded portion and the corresponding end of the other flat plate portion are joined to each other. The first folded piece portion is in surface contact with the inner surface of the tube at each end in the width direction of the one flat plate portion, and the subsequent folded piece portion is in surface contact with the preceding folded piece portion. The tube inner dimension is determined to be a dimension corresponding to the thickness of the folded piece portion × the number of the folded piece portions. It consists of what is characterized by this.
[0010]
In such a heat exchanger tube, the folded portion of the folded portion comes into surface contact with the tube inner surface of the flat plate portion, and the subsequent folded piece portion comes into surface contact with the preceding folded piece portion. Folded so that And Such a folded portion can be formed by press working.
[0011]
Also, a butt that protrudes to a position where it substantially contacts the other flat plate portion toward the other flat plate portion by bending the one flat plate portion itself at the center portion in the width direction of the one flat plate portion. A structure in which the portion is formed may be employed. Moreover, the said folding | returning part can be joined to the corresponding edge part of the other flat plate part by brazing.
[0012]
The following configuration may be further added to such a heat exchanger tube. For example, it can be set as the structure by which the inner fin is provided between the said flat plate-shaped parts.
[0013]
Also, at least one of the flat plate-like portions is provided with a plurality of protrusions protruding toward the inside of the tube, and the protrusions facing each other, or the flat plate-like portion provided with the protrusion and the protrusions are provided. It can be set as the structure where the inner surface of the opposing flat plate-shaped part is mutually abutted. In addition, the flat plate-like portion may be formed so as to bulge outward from the tube so that the substantially central portion in the width direction is the apex, thereby improving the pressure resistance of the tube.
[0014]
Furthermore, it can be set as the structure by which the groove | channel extended in the direction which mutually cross | intersects is provided on each opposing surface of the said flat plate-shaped part.
[0015]
The heat exchanger according to the present invention has the structure of the heat exchanger tube as described above. The type of heat exchanger is not particularly limited. For example, the present invention can be applied to a heat exchanger in which tubes and fins are alternately arranged.
[0016]
In addition, the method for manufacturing a heat exchanger tube according to the present invention includes: (a) bending at least one end in the width direction of a single flat plate having a predetermined width so that the end is folded back in the opposite direction a plurality of times. To form the folded part And the first folded piece portion is in surface contact with the one end portion, and the subsequent folded piece portion is folded back so as to be in surface contact with the preceding folded piece portion, (B) Bending the widthwise center of the flat plate so that the folded portion is on the inside to form two flat plate-like portions forming a heat exchange medium flow path therebetween, (c) at least one of them The folded portion formed at the end portion of the flat plate portion is joined to the corresponding end portion of the other flat plate portion. In addition, the inner dimension of the tube is determined to be a dimension corresponding to the thickness of the folded piece portion × the number of the folded piece portions. It consists of the method characterized by this.
[0017]
Furthermore, in the method for manufacturing a heat exchanger tube according to the present invention, (a) at least one of the two flat plates each having a predetermined width is opposite to each other a plurality of times at both ends in the width direction. Folded to form a folded part In addition, the first folded piece portion is in surface contact with each end portion of the one flat plate, and the subsequent folded piece portion is folded back so as to be in surface contact with the preceding folded piece portion, (B) A folded portion of a flat plate in which folded portions are formed at both ends in the width direction and a corresponding end portion of the other flat plate are joined to each other. In addition, the inner dimension of the tube is determined to be a dimension corresponding to the thickness of the folded piece portion × the number of the folded piece portions. It consists of the method characterized by this.
[0018]
In such a manufacturing method, the folded portion is folded so that the first folded piece portion is in surface contact with the flat plate and the subsequent folded piece portion is in surface contact with the preceding folded piece portion. But, Such a folded portion can be formed by press working.
[0019]
Further, before or after the formation of the folded portion, the one flat plate itself is bent at the center in the width direction of one flat plate, so that the other flat plate is substantially moved toward the other flat plate in the state after the tube is completed. A butting portion that protrudes to a position that contacts the flat plate can be formed. The folded portion can be joined to the corresponding end of the other flat plate by brazing.
[0020]
Also in this manufacturing method, it is possible to add a step of interposing an inner fin between the tube forming flat plates. Moreover, you may make it form in the said flat plate the some protrusion part which protrudes toward the inside of a tube in the case of tube formation.
[0021]
Furthermore, grooves extending in directions intersecting with each other at the time of tube formation may be formed on the surfaces of the flat plates which are surfaces facing each other at the time of tube formation.
[0022]
In the heat exchanger tube and the manufacturing method thereof as described above, the folded portion formed at the end in the width direction of at least one flat plate portion can be formed by, for example, press working. Accordingly, the processing cost is low, and the previously cut to a predetermined width is pressed, so that processing defects do not occur and correction processing is unnecessary. As a result, the manufacturing cost is greatly reduced.
[0023]
In addition, the folded portions are not brought into contact with each other as in the prior art, but the folded portion is in surface contact with the corresponding widthwise end portion of the other flat plate portion (this portion may also be formed in the folded portion). Since bonding can be performed in a state, a sufficiently large bonding area is obtained, high bonding strength is ensured, and high pressure resistance can be realized. And since the folded portion is bent so as to be folded in opposite directions a plurality of times and formed so that the folded piece portions are overlapped in a surface contact state, the folded portion itself is secured with high strength and the above Thus, high joint strength is ensured by the joint surface in the surface contact state, and high pressure resistance can be realized as a whole tube.
[0024]
Furthermore, since the folded portion is formed by being bent so as to be folded back in the opposite direction a plurality of times, the thickness of the folded portion can be defined by the number of times of folding. That is, the thickness of the folded portion, particularly the thickness of the folded portion that contributes to the determination of the inner dimensions of the tube, can be determined by the number of times of folding, that is, the number of stacked folded pieces, and the degree of design freedom is greatly increased. . The thickness of the folded piece portions, and the first folded piece and the tube inner surface forming surface of the flat plate portion are brought into surface contact with each other, so that the thickness of the folded piece x the number of folded pieces is accurately determined. The corresponding dimensions are determined. Therefore, the inner dimension of the tube to be formed is also accurately determined as the target dimension, and a highly accurate tube is obtained.
[0025]
In addition, even when a butt portion is provided, the butt portion can be formed by bending the flat plate portion itself, so that a portion requiring brazing or the like does not occur in the central portion in the width direction of the tube, and the flux It is possible to eliminate the risk of insufficient coating, poor brazing due to the application, and defective portions with respect to leakage.
[0026]
If the butt part is provided, the tube can be reinforced at the center in the width direction while maintaining the above-mentioned effects. Therefore, when brazing the core part, the tube is deformed or brazed to the core part. It becomes possible to prevent the occurrence of defective brazing, leaked parts, etc. due to the difference in thermal expansion coefficient with the jig for use.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a heat exchanger 1 according to an embodiment of the present invention. The heat exchanger 1 has two tank parts 2 and 3 on the inlet / outlet side and a flow path for circulating a heat exchange medium provided between the tank parts 2 and 3 and communicating between the tank parts 2 and 3. A plurality of heat exchange tubes 4 and corrugated fins 5 are provided, and the heat exchange tubes 4 and the fins 5 are alternately arranged. In this embodiment, side plates 7 and 8 are provided on the outermost layer of the core portion 6 having the heat exchange tubes 4 and the fins 5. Further, brackets 9 and 10 for attaching the heat exchanger 1 are joined to the outer surface side of one side plate 8 and the side surface of one tank portion 2. The tank portions 2 and 3 are provided with fittings 11 and 12 for connecting pipes or other devices, respectively.
[0028]
The heat exchange tube 4 of such a heat exchanger 1 is configured, for example, as shown in FIGS. 2 to 5 (heat exchange tubes 21a, 21b, 21c, 31, 41a, 41b, 41c, 51).
The heat exchange tube 21a of the mode shown in FIG. 2A is opposed to each other with a gap, and has two flat plate portions 23a and 23b forming a heat exchange medium flow path 22 therebetween, and both flat plate portions 23a and 23b. Are formed at the other widthwise end of one flat plate portion 23a, and the end portions are formed a plurality of times. (In the present embodiment, twice) a folded portion 25a bent so as to be folded in opposite directions, and the corresponding folded portion 25a and the corresponding end portion 25b of the other flat plate portion 23b (in this embodiment) The end portion is not formed with a folded portion) (joined portion 26). In the folded portion 25a, the first folded piece portion 27a is in close contact with the inner surface of the tube of the flat plate portion 23a by surface contact, and the subsequent folded piece portion 27b is in close contact with the previous folded piece portion 27a by surface contact. Wrapped. The folded piece portion 27b of the folded portion 25a is joined by brazing so as to be in close contact with the corresponding end portion 25b of the other flat plate portion 23b by surface contact. Such a folded portion 25a is formed by press working.
[0029]
In the heat exchange tube 21b of the mode shown in FIG. 2B, a folded portion 28 that is folded only once is formed at one end corresponding to the other flat plate portion 23b, and the folded portion 25a and the folded portion 28 are surfaces. They are joined by brazing so as to be in close contact with each other. In the heat exchange tube 21c of the aspect shown in FIG. 2 (C), folded portions 25a that are folded twice are formed at the ends corresponding to each other of the flat plate portions 23a and 23b, and the folded portions 25a are in surface contact with each other. It is joined by brazing so that it adheres more closely. In this way, the number of times of folding of the folded portion and the form of the corresponding end portion of the other flat plate portion 23b can be freely set, and the inner dimension (flow channel height) of the tube is between the flat plate portions 23a and 23b. The target size is accurately determined by the number of intervening folded pieces. Of course, internal dimensions other than those shown in the figure are possible, and the number of folded pieces interposed between the flat plate portions 23a and 23b and the number of times of folding in the folded portions may be determined according to the target dimensions.
[0030]
The heat exchange tube 31 of the aspect shown in FIG. 3 has two flat plate-like parts 33a and 33b that form the heat exchange medium flow path 32, and the two flat plate-like parts 33a and 33b, as in the heat exchange tube 21a. Are formed at the other end in the width direction of the flat plate portion 33a and the end portions are bent a plurality of times (twice in this embodiment) so as to be folded back in opposite directions. The folded portion 35a and the corresponding end portion 35b of the other flat plate portion 33b (in this embodiment, the folded portion is not formed at the end portion) are joined to each other. (Joint part 36). In this embodiment, the inner surface of the flat plate portion 33a is substantially directed toward the other flat plate portion 33a by bending the flat plate portion 33b itself at the center in the width direction of the one flat plate portion 33b. A butting portion 37 is formed so as to protrude to a position where it abuts against. The front end surface of the abutting portion 37 may be joined to the inner surface of the flat plate-like portion 33a, or may simply be in contact therewith. A similar configuration can be adopted for the heat exchange tubes 21b and 21c.
[0031]
The heat exchange tube 41a in the embodiment shown in FIG. 4A is opposed to each other with a gap, and has two flat plate portions (flat plates) 43a and 43b forming a heat exchange medium flow path 42 therebetween, and one flat plate shape. The end portions in the width direction of the portion 43a have folded portions 44a and 44b that are bent so that each end portion is folded back multiple times, and the folded portions 44a and 44b correspond to both end portions in the width direction of the other flat plate 43b. It is joined to 45a, 45b by brazing (joint portions 46a, 46b). In the folded portions 44a and 44b, the first folded piece portion 47a comes into close contact with the inner surface of the tube of the flat plate portion 43a by surface contact, and the subsequent folded piece portion 47b comes into close contact with the previous folded piece portion 47a through surface contact. Is folded. The folded pieces 47b of the folded portions 44a and 44b are joined by brazing so as to be in close contact with the corresponding end portions 45a and 45b of the other flat plate portion 43b by surface contact. Such folded portions 44a and 44b are formed by pressing.
[0032]
In the heat exchange tube 41b of the mode shown in FIG. 4 (B), the folded portions 48 that are folded only once are formed at the corresponding ends of the other flat plate portion 43b, and the folded portions 44a and 44b correspond to them. The folded portions 48 to be joined are joined by brazing so as to be brought into close contact by surface contact. In the heat exchange tube 41c of the aspect shown in FIG. 4 (C), the folded portions 44a and 44b that are folded twice are formed at both ends corresponding to each other of the flat plate portions 43a and 43b, respectively. Are joined by brazing so as to be in close contact by surface contact. As described above, even in a mode in which the tubes are separated from each other before forming the tube, the number of times of folding of the folded portion and the form of the corresponding end portion of the other flat plate portion 43b can be freely set. The height is accurately determined as a target dimension depending on the number of folded pieces interposed between the flat plate portions 43a and 43b. Of course, in this aspect, internal dimensions other than those shown in the figure are possible, and the number of folded pieces interposed between the flat plate portions 43a and 43b and the number of folded times in the folded portions are determined according to the target dimensions. Just decide.
[0033]
The heat exchange tube 51 of the aspect shown in FIG. 5 is similar to that shown in FIG. 4A, and includes two flat plate portions 53a and 53b that form the heat exchange medium flow path 52, and one flat plate portion 53a. There are folded portions 54a and 54b that are bent so that each end portion is folded back multiple times at both ends in the width direction, and the folded portions 54a and 54b correspond to both width direction end portions 55a and 55b corresponding to the other flat plate 53b. Are joined by brazing (joining portions 56a and 56b). In this embodiment, the flat plate portion 53b itself is bent at the center in the width direction of one flat plate portion 53b, so that the inner surface of the flat plate portion 53a is substantially directed toward the other flat plate portion 53a. A butting portion 57 is formed so as to protrude to a position where it abuts against. The front end surface of the abutting portion 57 may be joined to the inner surface of the flat plate-like portion 53a, or may simply be in contact therewith.
[0034]
Each of the heat exchange tubes as shown in FIGS. 2 to 5 is generally temporarily assembled with other heat exchanger parts such as fins and header pipes, joined by brazing in a furnace, and manufactured as a heat exchanger. . Further, as will be described later, inner fins may be inserted into the tube for the purpose of improving pressure resistance and heat transfer performance. That is, fins may be bonded to both the inside and outside of the tube. In such a case, a clad material in which a brazing material is attached to either a fin or a tube shell is usually used for brazing joining. In this case, it goes without saying that the tube shell is liquid-tightly brazed if a clad material with brazing material attached to both sides of the tube shell is used, but it is possible to use a bare material that does not clad the brazing material for the fins. It is. Moreover, when considering brazing only of the tube shell, a method of using a material clad with brazing material on both the inner and outer surfaces, a method of using a material clad only on one surface, or a method of combining these materials can be selected as appropriate.
[0035]
The heat exchange tubes 21a, 31, 41a, 51 shown in FIGS. 2 to 5 are manufactured by methods as shown in FIGS. 6 to 9, respectively. The heat exchange tubes 21b, 21c, 41b, and 41c can be manufactured by the same method.
[0036]
FIG. 6 shows a method of manufacturing the heat exchange tube 21a shown in FIG. First, a flat plate 63 having a predetermined width is formed from a wide flat plate 61 as a tube forming material by cutting with an appropriate cutter device 62 or the like. Next, one end portion in the width direction of one flat plate 63 having a predetermined width is bent so as to be folded twice, and a folded portion 25a is formed at the end portion.
[0037]
Next, the center part in the width direction of the flat plate 63 is bent to the upper surface side of FIG. 6, and the two flat plate-like parts 23 a and 23 b that are opposed to each other with a space therebetween and that form the heat exchange medium flow path 22 are formed. Form. Then, the folded portion 25a at the end of the flat plate portion 23a and the end portion 25b of the flat plate portion 23b are bonded to each other (bonded portion 26), thereby completing the heat exchange tube 21a shown in FIG.
[0038]
FIG. 7 shows a manufacturing method of the heat exchange tube 31 shown in FIG. First, a flat plate 71 having a predetermined width slightly larger than that shown in FIG. 6 is formed from a wide flat plate 61 as a material by cutting with a cutter device 62 or the like. Next, the butt portion 37 is formed at a predetermined position of the one flat plate 71 by bending. Then, one end portion in the width direction of the flat plate 71 is bent so as to be folded twice toward the same surface as the abutting portion 37, and a folded portion 35a is formed at the end portion. Next, two flat plate portions 33a are formed by bending the center portion in the width direction of the flat plate 71 on the same surface side as the abutting portion 37, facing each other with a space therebetween, and forming the heat exchange medium flow path 32 therebetween. 33b is formed. Then, the folded portion 35a at the end of the flat plate portion 33a and the end portion 35b of the flat plate portion 33b are bonded to each other (bonding portion 36), thereby completing the heat exchange tube 31 shown in FIG.
[0039]
FIG. 8 shows a method of manufacturing the heat exchange tube 41a shown in FIG. First, two flat plates 81a and 81b having different widths are formed from a wide flat plate 61 as a material by cutting with a cutter device 62 or the like. Next, folded portions 44a and 44b are respectively formed by bending at both ends of one flat plate 81a. Both flat plates 81a and 81b are positioned as both flat plate portions 43a and 43b so that the folded portions 44a and 44b and both end portions 45a and 45b of the corresponding flat plate portions face each other, and are joined to each other (joint portion). 46a, 46b), the heat exchange tube 41a shown in FIG. 4 is completed.
[0040]
FIG. 9 shows a manufacturing method of the heat exchange tube 51 shown in FIG. First, two flat plates 91 a and 91 b are formed from a wide flat plate 61 as a material by cutting with a cutter device 62. Next, a butt portion 57 is formed at the center in the width direction of one flat plate 91b by bending. Folded portions 54a and 54b are formed at both ends of the other flat plate 91a by bending each end so as to be folded back multiple times. The folded portions 54a and 54b are joined to the corresponding widthwise end portions 55a and 55b of the other flat plate 91b by brazing (joining portions 56a and 56b), thereby completing the heat exchange tube 51 shown in FIG. .
[0041]
In the tube for a heat exchanger manufactured and configured as described above, the folded portion formed at the end in the width direction of at least one flat plate portion is not abutted and joined as in the conventional case. Since it can be joined in a surface contact state to the corresponding widthwise end of the other flat plate-like part, a sufficiently large joining area can be obtained, high joining strength can be ensured, and high pressure resistance can be realized. And since the folded portion is bent so as to be folded back and forth in a plurality of times and formed so that the folded piece portion is overlapped in a surface contact state, high strength is ensured for the folded portion itself, As described above, a high bonding strength is ensured by the bonding surface in the surface contact state, and higher pressure resistance can be realized as a whole tube.
[0042]
Moreover, the folding | returning part formed in the width direction edge part of a flat plate-shaped part can be shape | molded by press work. Therefore, the conventional roll processing becomes unnecessary, and the manufacturing cost, and consequently the manufacturing cost of the tube and further the heat exchanger can be greatly reduced. Further, since roll processing is not performed, correction after processing or the like is not required, the generation rate of defective products can be greatly reduced, and manufacturing can be facilitated and manufacturing cost can be further reduced.
[0043]
In addition, the folded part is formed by being bent so that it is folded in the opposite direction several times, and the inner dimensions of the tube can be determined substantially freely and accurately depending on the number of times of folding. The degree is greatly increased. The inner dimension of this tube is such that the folded pieces are in contact with each other, and the first folded piece and the tube inner surface forming surface of the flat plate portion are in surface contact with each other, so that the thickness of the folded piece x the folded piece more accurately. The dimension corresponding to the number of. Therefore, the inner dimension of the tube to be formed is also accurately determined with high accuracy to the target dimension, and a tube having a desired inner dimension can be easily obtained.
[0044]
In addition, since there is no brazed portion at the central portion in the width direction of the tube, there is no fear of a flux rotation failure or the like. Further, the butting portion for reinforcing the tube can be easily formed by bending one flat plate portion itself, so that a high-strength tube structure can be easily realized.
[0045]
In addition, this butted portion is basically a part that does not require flux to flow from other parts or to apply the flux from the outside. There is no occurrence. Therefore, it is possible to easily prevent the occurrence of a defective brazing point.
[0046]
Furthermore, in the structure having a butt portion, it is generated due to the difference in thermal expansion coefficient between the core portion and the brazing jig when the core portion 6 is brazed with a jig. High resistance against deformation force and displacement force. As a result, it is possible to effectively prevent deformation of the tube and occurrence of defective brazing. Therefore, it is possible to manufacture a high-performance heat exchanger that is securely brazed and has no fear of leakage.
[0047]
In the above description of the manufacturing method, the butt portion is formed before the end folded portion is formed. However, it can be formed after the end folded portion is formed.
[0048]
The following configuration can be further added to the heat exchanger tube having the configuration shown in FIGS. The following additional structure will be described for the heat exchanger tube having the structure shown in FIG. 2A, but can be similarly applied to the tube having the structure shown in FIGS.
[0049]
First, in the heat exchange tube 201 shown in FIG. 10, a corrugated inner fin 204 is provided in the heat exchange medium flow path 203 formed between the flat plate portions 202 a and 202 b of the tube 201. The path 203 is divided into a plurality of sections. The structure of the inner fin 204 is not particularly limited, and other than the corrugation can be applied. Such an inner fin 204 can be inserted after the tube 201 is formed, or the tube 201 can be bent and formed after the inner fin 204 is disposed.
[0050]
In the heat exchange tube 201 having such a configuration, in addition to the operations and effects described with reference to FIG. 2A, the temperature of the tube 201 is made uniform, and the heat exchange performance of the tube 201 is further improved. The
[0051]
Moreover, in the heat exchange tube 211 shown to FIG. 11 (A), (B), the some flat part 212a, 212b of the tube 211 is provided with the some protrusion part 213 which protrudes toward a tube inward, and protrudes. The portions 213 are arranged to face each other and the front end surfaces are in contact with each other. Each protrusion 213 can be easily formed by embossing a flat plate material before tube formation, and may be tube processed after formation.
[0052]
In the heat exchange tube 211 having such a configuration, in addition to the operation and effect described with reference to FIG. 2A described above, the mixing effect of the heat exchange medium flowing through the flow path is improved by the protruding portion 213. The heat exchange performance by the tube 211 is further improved.
[0053]
The protruding portion 213 may be provided only on one flat plate portion, and the tip end surface of the protruding portion 213 may be brought into contact with the inner surface of the other flat plate portion facing each other.
[0054]
Furthermore, in the heat exchange tube 221 shown in FIGS. 12A and 12B, a plurality of grooves 223a and 223b extending obliquely in a direction intersecting each other are formed on the opposing surfaces of the flat plate portions 222a and 222b. It is installed. For example, as shown in FIG. 13, the grooves 223 a and 223 b are formed on the flat plate material 224 before being formed on the tube 221, so that the grooves 223 a and 223 a extend in a direction intersecting with each other as described above when formed on the tube 221. 223b may be engraved and then processed into a tube 221.
[0055]
In the heat exchange tube 221 having such a configuration, in addition to the operations and effects described with reference to FIG. 2A, the mixing effect of the heat exchange medium flowing in the flow path is improved by the intersecting grooves 223a and 223b. Therefore, the temperature is made uniform and the heat transfer is promoted, and the heat exchange performance by the tube 221 is further improved.
[0056]
Furthermore, in the present invention, for example, as shown in FIG. 14, the flat plate-like portions 232a and 232b have a shape that bulges outward from the tube so that the substantially central portion in the width direction is the apex. You may comprise. With this configuration, the pressure resistance of the tube 231 can be improved. This bulge amount δ may be a very small amount.
[0057]
In addition, the tube for heat exchangers which concerns on this invention is not limited to the type of heat exchanger as shown in FIG. 1, but can be applied to all types of heat exchangers. It is particularly suitable for heat exchangers for vehicles, such as heaters for radiators and air conditioners, condensers, evaporators, and further intercoolers.
[0058]
【The invention's effect】
As described above, when the tube for a heat exchanger according to the present invention and the method for manufacturing the same are formed, a folded portion that is folded back multiple times by pressing or the like is formed at the end of at least one flat plate portion of the tube, and the folded portion Is joined to the corresponding end portion of the other flat plate portion by brazing or the like, so that a sufficiently large joining area can be secured and high joining strength and high pressure resistance can be obtained. In addition, the inner dimension of the tube can be set to a desired dimension substantially freely and accurately depending on the number of times of folding of the folded portion, and a heat exchanger tube with a high degree of design freedom can be easily and inexpensively manufactured. Furthermore, since there is no brazing part in the center part in the tube width direction, it is possible to remove anxiety such as a brazing defect due to a flux rotation defect, and it is possible to obtain a tube in which desired joining is reliably performed.
[0059]
Also, if the butt portion is formed by bending on one flat plate-like portion, the deformation resistance of the tube can be greatly increased, and when the core portion of the heat exchanger is brazed, It is possible to prevent occurrence of defective brazing and leakage due to collapse of the tube due to a difference in thermal expansion coefficient from the brazing jig.
[Brief description of the drawings]
FIG. 1 is a front view of a heat exchanger according to an embodiment of the present invention.
FIG. 2 is a partial perspective view of each heat exchanger tube according to an embodiment of the present invention.
FIG. 3 is a partial perspective view of a heat exchanger tube according to another embodiment of the present invention.
FIG. 4 is a partial perspective view of each heat exchanger tube according to still another embodiment of the present invention.
FIG. 5 is a partial perspective view of a heat exchanger tube according to still another embodiment of the present invention.
6 is a process flow diagram showing a method for manufacturing the heat exchanger tube of FIG. 2 (A). FIG.
7 is a process flow diagram showing a method for manufacturing the heat exchanger tube of FIG. 3; FIG.
8 is a process flow diagram showing a method for manufacturing the heat exchanger tube of FIG. 4 (A). FIG.
FIG. 9 is a process flow diagram showing a method for manufacturing the heat exchanger tube of FIG. 5;
10 is a partial perspective view of a tube showing a modification of the heat exchanger tube shown in FIG. 2 (A). FIG.
11 (A) is a partial perspective view of a tube showing another modification of the heat exchanger tube shown in FIG. 2 (A), and FIG. 11 (B) is an AA view of the tube of FIG. It is sectional drawing which follows a line.
12 (A) is a partial perspective view of a tube showing still another modified example of the heat exchanger tube shown in FIG. 2 (A), and FIG. 12 (B) is an enlarged front view of the tube of FIG. FIG.
13 is a partial plan view of a flat material before tube processing of the tube shown in FIG.
14 is a cross-sectional view of a tube showing a modification of the heat exchanger tube shown in FIG. 2 (A). FIG.
FIG. 15 is a partial perspective view of a conventional heat exchanger tube.
FIG. 16 is a partial perspective view of another conventional heat exchanger tube.
[Explanation of symbols]
1 heat exchanger
2, 3 Tank part
4 tubes
5 Fin
6 Core part
7, 8 Side plate
9, 10 Bracket
11, 12 Fitting
21a, 21b, 21c, 31, 41a, 41b, 41c, 51, 201, 211, 221, 231 Heat exchange tube
22, 32, 42, 52, 203 Heat exchange medium flow path
23a, 23b, 33a, 33b, 43a, 43b, 53a, 53b, 202a, 202b, 212a, 212b, 222a, 222b Flat plate (flat plate)
24, 34 Bending part
25a, 28, 35a, 44a, 44b, 48, 54a, 54b Folding part
25b, 35b, 45a, 45b, 55a, 55b End of the corresponding flat plate-like part
26, 36, 46a, 46b, 56a, 56b
27a, 27b, 47a, 47b Folded piece
37, 57 Butt section
61 Wide flat plate as a material
62 Cutter device
63, 71, 81a, 81b, 91a, 91b Flat plate cut to a predetermined width
204 Inner fin
213 Protrusion
223a, 223b groove
224 flat plate material
232a, 232b Swelled flat plate portion

Claims

Two plate-like portions that face each other and form a heat exchange medium flow path, a bending portion that integrally connects the two plate-like portions at one widthwise end of both plate-like portions, and at least A folded portion formed at the other widthwise end portion of one flat plate portion and bent so that the end portion is folded back in the opposite direction a plurality of times, and the folded portion and the other flat plate portion And the corresponding folded end portion of the first folded plate portion is in surface contact with the inner surface of the tube at the other widthwise end portion of the one flat plate portion. The part is folded so as to be in surface contact with the previous folded piece part, and the inner dimension of the tube is determined to be a dimension corresponding to the thickness of the folded piece part x the number of folded piece parts , Tube for heat exchanger.

Two flat plate portions facing each other and forming a heat exchange medium flow path therebetween, and bending at each end in the width direction of at least one flat plate portion so that each end portion is folded back in the opposite direction multiple times. The folded portion and the corresponding end portion of the other flat plate portion are joined to each other, and the folded portion has its first folded piece portion as the one flat plate portion. It is folded so that the inner surface of the tube is in surface contact with the inner surface of the tube at each end in the width direction, and the subsequent folded piece is in surface contact with the preceding folded piece, and the inner dimension of the tube is the thickness of the folded piece × the folded piece A tube for a heat exchanger, characterized in that it has a dimension corresponding to the number of parts .

The heat exchanger tube according to claim 1 or 2 , wherein the folded portion is formed by pressing.

At the central portion in the width direction of one flat plate portion, a butt portion that protrudes to a position where it substantially contacts the other flat plate portion toward the other flat plate portion by bending the one flat plate portion itself. The heat exchanger tube according to any one of claims 1 to 3 , wherein the heat exchanger tube is formed.

The heat exchanger tube according to any one of claims 1 to 4 , wherein the folded portion is joined to a corresponding end portion of the other flat plate portion by brazing.

The heat exchanger tube according to any one of claims 1 to 5 , wherein an inner fin is provided between the flat plate portions.

At least one of the flat plate-like portions is provided with a plurality of protruding portions protruding toward the inside of the tube, and the protruding portions facing each other, or the protruding portion and the flat plate-like portion provided with the protruding portions are opposed. The tube for heat exchangers according to any one of claims 1 to 5 , wherein the inner surfaces of the flat plate portions are abutted against each other.

The heat exchanger tube according to any one of claims 1 to 5, wherein a groove extending in a direction intersecting with each other is provided on each facing surface of the flat plate-like portion.

The heat exchanger tube according to any one of claims 1 to 8 , wherein the flat plate portion bulges outward from the tube so that a substantially central portion in the width direction is a vertex.

The heat exchanger which has the tube for heat exchangers in any one of Claim 1 thru | or 9 .

The heat exchanger according to claim 10 , wherein the tubes and the fins are alternately arranged.

(A) At least one end portion in the width direction of a single flat plate having a predetermined width is bent so that the end portions are folded back in opposite directions a plurality of times , and a first folded piece portion is formed. Is folded so that the one end is in surface contact with the following folded piece, and (b) the widthwise central portion of the flat plate is bent so that the folded portion is on the inside. Forming two plate-like portions forming a heat exchange medium flow path therebetween, and (c) at least one of the plate-like portions formed on the end portion of the plate-like portion is replaced with the other plate-like portion. And a tube inner dimension is determined to be a dimension corresponding to the thickness of the folded piece portion × the number of the folded piece portions .

(A) At the both ends in the width direction of at least one flat plate of two flat plates each having a predetermined width, each end portion is bent so as to be folded back and forth in the opposite direction, and a folded portion is formed . The first folded piece is folded back so as to be in surface contact with each end of the one flat plate, and the subsequent folded piece is brought into surface contact with the preceding folded piece, and (b) folded portions at both ends in the width direction. The folded portion of the flat plate formed with the other end and the corresponding end portion of the other flat plate are joined together, and the inner dimension of the tube is determined to be a dimension corresponding to the thickness of the folded piece portion × the number of the folded piece portions. A method for producing a tube for a heat exchanger, characterized by:

The manufacturing method of the tube for heat exchangers of Claim 12 or 13 which forms the said folding | turning part by press work.

Before or after the formation of the folded portion, the one flat plate itself is bent at the center in the width direction of one flat plate, so that the other flat plate is substantially directed toward the other flat plate in a state after the tube is completed. The manufacturing method of the tube for heat exchangers in any one of Claim 12 thru | or 14 which forms the butt | matching part which protrudes to the position which contact | abuts.

The manufacturing method of the tube for heat exchangers in any one of Claim 12 thru | or 15 which joins the said folding | turning part to the corresponding edge part of the other flat plate by brazing.

The manufacturing method of the tube for heat exchangers in any one of Claim 12 thru | or 16 which interposes an inner fin between the said flat plates for tube formation.

The manufacturing method of the tube for heat exchangers in any one of Claim 12 thru | or 16 which forms the some protrusion part which protrudes toward the tube inward in the said flat plate at the time of tube formation.

The tube for a heat exchanger according to any one of claims 12 to 16 , wherein grooves extending in directions intersecting with each other at the time of tube formation are formed on the surfaces of the respective flat plates which are surfaces facing each other at the time of tube formation. Production method.