JP3855853B2

JP3855853B2 - Flat tube and roll forming method and apparatus thereof

Info

Publication number: JP3855853B2
Application number: JP2002164356A
Authority: JP
Inventors: 友昭吉森; 一浩光川
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2002-06-05
Filing date: 2002-06-05
Publication date: 2006-12-13
Anticipated expiration: 2022-06-05
Also published as: JP2004009087A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱交換器等に用いる中央に補強部を備えた偏平チューブと、その偏平チューブをロール成形する方法および装置に関する。
【０００２】
【従来の技術】
従来、車両用のラジエータや温水式暖房装置等の熱交換器には、熱交換用の流体を流通させる偏平チューブが用いられている。図６は従来の偏平チューブの断面図であり、（ａ）はロール成形後を示す。図に示すように、偏平チューブを幅の広い熱交換器に適用できるように、中央に補強部６１を設けた断面横θ形状の偏平チューブ６０としている（特開平６−１２３５７１号公報参照）。
【０００３】
この補強部６１は、板材の両端を垂直に折り曲げた水直方向折り曲げ部６３と、板材の中央部を山形に折り返してなる折り返し突部６２とからなり、両部６２、６３はロウ付けにより接合されている。そして、この偏平チューブは、熱交換器の容器（タンク等）にロウ付けして用いられる。また、偏平チューブ等の長尺の部材を冷間で連続的に成形し量産する方法としてロール成形法が知られている。
【０００４】
例えば、特開平１０−８５８７７号公報では、ロール成形により帯板の幅方向中央部に台形形状の突部を形成する第１ロール成形工程（手段）と、その台形の上辺の幅を順次狭めて略三角形の突部としたのち突出した２辺の内側を密着させた折り返し突部を形成する第２ロール成形工程（手段）と、帯板の横幅方向両端に折り返し突部の高さ以下の垂直方向折り曲げ部を形成する第３ロール成形工程（手段）と、垂直方向折り曲げ部と折り返し突部との中間を半円状に折り曲げ平板部を互いに平行にすると共に垂直方向折り曲げ部を折り返し突部の両側面に密着せる第４ロール成形工程（手段）とからなる成形方法および装置が提案されている。
【０００５】
【発明が解決しようとする課題】
しかし、上述の折り曲げ形状は、材料板厚が約０．２５〜０．３ｍｍの範囲では問題ないが、材料板厚がそれよりも薄くなると、例えば約０．１５〜０．２ｍｍの範囲ではロウ付け時に前期水直方向折り曲げ部６３が熱応力により変形して前記折り返し突部６２との隙間が大きくなり充分なフィレットが形成されにくくなる。
【０００６】
図６の（ｂ）はロウ付け後で充分なフィレットＦが形成されている補強部６１周りの部分断面図、（ｃ）はロウ付け後で充分なフィレットＦが形成されていない補強部６１周りの部分断面図である。（ｃ）のように、充分なフィレットＦが形成されないと耐圧強度が低下し、漏れが発生し易くなるという問題がある。
【０００７】
本発明は、上記従来技術の問題点に鑑みて成されたものであり、その目的は、中央に折り返した突部を有する補強部を備えた偏平チューブにおいて、耐圧強度を確保して漏れが発生しにくい偏平チューブと、そのロール成形方法および装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記目的を達成するために、請求項１ないし請求項７に記載の技術的手段を採用する。すなわち、請求項１に記載の発明では、長尺の１枚の帯板（Ｗ）を順次折り曲げて断面が横θ形状を有し中央に補強部（６１）を備えた偏平チューブであって、
一方の長方形状の垂平方向折り曲げ部（６４）と、この垂平方向折り曲げ部（６４）の長辺から連続して略直角に形成された一方の水直方向折り曲げ部（６３）と、この水直方向折り曲げ部（６３）から連続にして略直角に形成された一方の平板状の第１平板部（６５）と、この第１平板部（６５）から連続に形成された一方の断面半円状の周曲部（６６）と、この周曲部（６６）から連続に形成され、第１平板部（６５）と略平行に設けられた一方の平板状の第２平板部（６７）と、この第２平板部（６７）から連続にして略直角に折り返し形成され、水直方向折り曲げ部（６３）と略平行に隣接して設けられた長方形状の折り返し突部（６２）と、この折り返し突部（６２）から連続にして第２平板部（６７）と対向する方向へ略直角に延びる他方の平板状の第２平板部（６７）と、この第２平板部（６７）から連続に形成された他方の断面半円状の周曲部（６６）と、この周曲部（６６）から連続して形成され、第２平板部（６７）と略平行に設けられた他方の平板状の第１平板部（６５）と、この第１平板部（６５）から連続して略直角に形成され、折り返し突部（６２）と略平行に隣接して設けられた他方の垂直方向折り曲げ部（６３）と、この垂直方向折り曲げ部（６３）から連続して略直角に形成され、第２平板部（６７）と略平行に設けられた他方の長方形状の垂平方向折り曲げ部（６４）とを備え、
折り返し突部（６２）の折り返した間、隣接して設けられた折り返し突部（６２）と水直方向折り曲げ部（６３）との間、および隣接して設けられた垂平方向折り曲げ部（６４）と第２平板部（６７）との間を接合し、水直方向折り曲げ部（６３）、垂平方向折り曲げ部（６４）、第１平板部（６５）、周曲部（６６）、および第２平板部（６７）とで囲まれた空間が熱交換流体の流通する流路を形成している。
【０００９】
図１は本発明の一実施形態における偏平チューブ６０の断面図であり、（ａ）はロール成形後、（ｂ）はロウ付け後で充分なフィレットＦが形成されている補強部６１周りの部分断面図、（ｃ）はロウ付け後で充分なフィレットＦが形成されていない補強部６１周りの部分断面図である。
【００１０】
（ｃ）のように充分なフィレットＦが形成されていなくとも折り返し突部（６２）と水直方向折り曲げ部（６３）との間、および垂平方向折り曲げ部（６４）と第２平板部（６７）との間の二ヶ所で接合するようになることより、熱変形が生じても耐圧強度を確保することができ、漏れが発生しにくい偏平チューブとすることができる。
【００１１】
請求項２に記載の発明では、長尺の１枚の帯板（Ｗ）を順次折り曲げて断面が横θ形状を有し中央に補強部（６１）を備えた偏平チューブを成形する偏平チューブのロール成形方法であって、
帯板（Ｗ）の幅方向中央部に台形形状の突部（６２ａ）を形成する第１ロール成形工程（１１）と、台形の上辺の幅を順次狭めて略三角形の突部（６２ｃ）としたのち突出した２辺の内側を密着させた折り返し突部（６２）を形成する第２ロール成形工程（２１〜２７）と、帯板（Ｗ）の横幅方向両端に垂直方向折り曲げ部（６３）を形成する第３ロール成形工程（３１、３２）と、垂直方向折り曲げ部（６３）の先端部に更に略直角に折り曲げた垂平方向折り曲げ部（６４）を形成する第４ロール成形工程（４１〜４５）と、垂直方向折り曲げ部（６３）と折り返し突部（６２）との中間に断面半円状の周曲部（６６）を形成して第１平板部（６５）と第２平板部（６７）とを互いに平行にすると共に、垂直方向折り曲げ部（６３）を折り返し突部（６２）の両側面に密着させ、垂平方向折り曲げ部（６４）と第２平板部（６７）とを密着させる第５ロール成形工程（５１〜５７）とからなることを特徴とする。
【００１２】
このようなロール成形方法により、垂平方向折り曲げ部（６４）を持った偏平チューブを成形することができる。
【００１３】
請求項３に記載の発明では、第４ロール成形工程（４１〜４５）は、帯板（Ｗ）を折り返し突部（６２）が突出する方向に湾曲させて垂平方向折り曲げ部（６４）を形成することを特徴とする。このようなロール成形方法により、垂直方向折り曲げ部（６３）から連続して更に略直角に形成した長方形状の垂平方向折り曲げ部（６４）を、アンダーカットとすることなく成形することができる。
【００１４】
請求項４に記載の発明では、第４ロール成形工程（４１〜４５）は、垂平方向折り曲げ部（６４）を形成した後、折り返し突部（６２）が突出する方向とは逆方向に湾曲させる矯正成形工程（４５）を含んでいることを特徴とする。このようなロール成形方法により、第１平板部（６５）と第２平板部（６７）とを略平行に設けることができると共に、接合部である折り返し突部（６２）と水直方向折り曲げ部（６３）との間、および垂平方向折り曲げ部（６４）と第２平板部（６７）との間を密着させて成形することができる。
【００１５】
請求項５に記載の発明では、長尺の１枚の帯板（Ｗ）を順次折り曲げて断面が横θ形状を有し中央に補強部（６１）を備えた偏平チューブを成形する偏平チューブのロール成形装置であって、
帯板（Ｗ）の幅方向中央部に台形形状の突部（６２ａ）を形成する第１ロール成形手段（１１）と、台形の上辺の幅を順次狭めて略三角形の突部（６２ｃ）としたのち突出した２辺の内側を密着させた折り返し突部（６２）を形成する第２ロール成形手段（２１〜２７）と、帯板（Ｗ）の横幅方向両端に垂直方向折り曲げ部（６３）を形成する第３ロール成形手段（３１、３２）と、垂直方向折り曲げ部（６３）の先端部に更に略直角に折り曲げた垂平方向折り曲げ部（６４）を形成する第４ロール成形手段（４１〜４５）と、垂直方向折り曲げ部（６３）と折り返し突部（６２）との中間に断面半円状の周曲部（６６）を形成して第１平板部（６５）と第２平板部（６７）とを互いに平行にすると共に、垂直方向折り曲げ部（６３）を折り返し突部（６２）の両側面に密着させ、垂平方向折り曲げ部（６４）と第２平板部（６７）とを密着させる第５ロール成形手段（５１〜５７）とからなることを特徴とする。
【００１６】
このようなロール成形装置により、垂平方向折り曲げ部（６４）を持った偏平チューブを成形することができる。
【００１７】
請求項６に記載の発明では、第４ロール成形手段（４１〜４５）は、帯板（Ｗ）を折り返し突部（６２）が突出する方向に湾曲させて垂平方向折り曲げ部（６４）を形成することを特徴とする。このようなロール成形装置により、垂直方向折り曲げ部（６３）から連続して更に略直角に形成した長方形状の垂平方向折り曲げ部（６４）を、アンダーカットとすることなく成形することができる。
【００１８】
請求項７に記載の発明では、第４ロール成形手段（４１〜４５）は、垂平方向折り曲げ部（６４）を形成した後、折り返し突部（６２）が突出する方向とは逆方向に湾曲させる矯正成形手段（４５）を含んでいることを特徴とする。
【００１９】
このようなロール成形装置により、第１平板部（６５）と第２平板部（６７）とを略平行に設けることができると共に、接合部である折り返し突部（６２）と水直方向折り曲げ部（６３）との間、および垂平方向折り曲げ部（６４）と第２平板部（６７）との間を密着させて成形することができる。ちなみに、上記各手段の括弧内の符号は、後述する実施形態に記載の具体的手段との対応関係を示す一例である。
【００２０】
【発明の実施の形態】
以下、本発明の実施形態を、図面に基づき説明する。図１は本発明の一実施形態における偏平チューブ６０の断面図であり、（ａ）はロール成形後の形状を示す。この偏平チューブ６０は、車両用のラジエータや温水式暖房装置等の熱交換器で、熱交換用の流体を流通させるのに用いられ、熱伝導の良好な黄銅やアルミニウムなどの板材を折り曲げて形成される。
【００２１】
具体的には、長尺の１枚の帯板を順次折り曲げ、断面が横θ形状を有する中央に補強部６１を備えた偏平チューブである。一方の長方形状の垂平方向折り曲げ部６４と、この垂平方向折り曲げ部６４の長辺から連続して略直角に形成された一方の水直方向折り曲げ部６３とを持つ。また、この水直方向折り曲げ部６３から連続にして略直角に形成された一方の平板状の第１平板部６５と、この第１平板部６５から連続に形成された一方の断面半円状の周曲部６６とを持つ。
【００２２】
また、この周曲部６６から連続に形成され、先の第１平板部６５と略平行に設けられた一方の平板状の第２平板部６７と、この第２平板部６７から連続にして略直角に折り返し形成され、先の水直方向折り曲げ部６３と略平行に隣接して設けられた長方形状の折り返し突部６２とを持つ。また、この折り返し突部６２から連続にして先の第２平板部６７と対向する方向へ略直角に延びる他方の平板状の第２平板部６７と、この第２平板部６７から連続に形成された他方の断面半円状の周曲部６６とを持つ。
【００２３】
また、この周曲部６６から連続して形成され、先の第２平板部６７と略平行に設けられた他方の平板状の第１平板部６５と、この第１平板部６５から連続して略直角に形成され、先の折り返し突部６２と略平行に隣接して設けられた他方の垂直方向折り曲げ部６３とを持つ。また、この垂直方向折り曲げ部６３から連続して略直角に形成され、先の第２平板部６７と略平行に設けられた他方の長方形状の垂平方向折り曲げ部６４とを持っている。
【００２４】
そして、先の折り返し突部６２の折り返した間、隣接して設けられた先の折り返し突部６２と先の水直方向折り曲げ部６３との間、および隣接して設けられた先の垂平方向折り曲げ部６４と先の第２平板部６７との間を接合している。これにより、水直方向折り曲げ部６３、垂平方向折り曲げ部６４、第１平板部６５、周曲部６６、および第２平板部６７とで囲まれた空間が熱交換流体の流通する流路となる。
【００２５】
これにより、接合部に充分なフィレットＦが形成されていなくとも、折り返し突部６２と水直方向折り曲げ部６３との間、および垂平方向折り曲げ部６４と第２平板部６７との間の二ヶ所で接合するようになることより、熱変形が生じても耐圧強度を確保することができ、漏れが発生しにくい偏平チューブ６０とすることができる。
【００２６】
次に、このような偏平チューブ６０をロール成形するための方法および装置について説明する。図２は、本発明の一実施形態におけるロール成形装置１の各ロール１１〜５７の配置図である。また、図３の（ａ）〜（ｐ）は、本発明の一実施形態における各ロール成形工程での材料の成形態様を示す図であり、図４は図３中本発明で新規となる第４ロール成形工程での材料の成形態様（ｈ）〜（ｌ）に対応する第４ロール成形手段での各ロール４１〜４５の型形状を示す図である。
【００２７】
図２の１は、長尺の１枚の帯板Ｗ（図３）を順次折り曲げて断面が横θ形状を有し中央に補強部６１を備えた偏平チューブ６０を成形する偏平チューブのロール成形装置である。このロール成形装置１は、図２に示すように、ロールの回転軸心が水平であるロール成形手段１１〜２４・２７・４１〜４５・５１〜５７と、ロールの回転軸心が垂直であるロール成形手段２５・２６とからなる。
【００２８】
始めに、ロール成形手段１１により、図３（ａ）に示すように、上辺の幅の大きい台形の突部６２ａを成形する。そして、ロール成形手段２１〜２３により、図３（ｂ）に示すようにその台形の上辺の幅を順次縮小する。そして、ロール成形手段２４により、図３（ｃ）に示すように、形状が三角形の突部６２ｃを形成する。
【００２９】
次に、ロールの回転軸が垂直であるロール成形手段２５・２６により、図３（ｄ）に示すように、突部６２ｃの突出した２辺の内側を密着させ、折り返し突部６２ｄを形成する。続いて、ロールの回転軸が水平であるロール成形手段２７により、折り返し突部６２ｄを上部から据え込み押圧し曲部の曲率半径を低減して角形形状化し、図３（ｅ）に示す折り返し突部６２を形成する。
【００３０】
次に、図３（ｆ）に示すように、ロール成形手段３１により折り返し突部６２を形成した中間成形体の両端部を４５°の角度に折り曲げ、折り曲げ部６３ａを形成する。続いて、図３（ｇ）に示すように、ロール成形手段３２により、上記折り曲げ部６３ａを垂直方向に折り曲げ垂直方向折り曲げ部６３を形成する。
【００３１】
次に、本実施形態での新規構成として、図３（ｈ）〜（ｌ）に示すように、垂直方向折り曲げ部６３の先端部に更に略直角に折り曲げた垂平方向折り曲げ部６４を形成する第４ロール成形手段４１〜４５がある。まず、図３（ｈ）に示すように、ロール成形手段４１により、中間成形体を折り返し突部６２が突出する方向に湾曲させながら、垂直方向折り曲げ部６３の先端部に更に４５°の角度に折り曲げた折り曲げ部６４ａを形成する。
【００３２】
次に、図３（ｉ）に示すように、ロール成形手段４２により、中間成形体を折り返し突部６２が突出する方向に更に湾曲させながら、垂直方向折り曲げ部６３の先端部に更に略直角に折り曲げた垂平方向折り曲げ部６４を形成する。次に、図３（ｊ）・（ｋ）に示すように、ロール成形手段４３・４４により、中間成形体の湾曲を平板に戻し、図３（ｌ）に示すように、ロール成形手段４５により、中間成形体を折り返し突部６２が突出する方向とは逆方向に湾曲させる矯正成形工程となっている。
【００３３】
次に、図３（ｍ）に示すように、ロール成形手段５１により、垂直方向折り曲げ部６３と折り返し突部６２との中間を３０°に折り曲げる。続いて、図３（ｎ）・（ｏ）に示すように、ロール成形手段５２〜５５により、垂直方向折り曲げ部６３と折り返し突部６２との中間を６０°（図示略）・９０°・１２０°・１５０°（図示略）に順次折り曲げる。
【００３４】
そして、図３（ｐ）に示すように、最後に成形ロール５６により第１平板部６５と第２平板部６７とを互いに平行にすると共に、垂直方向折り曲げ部６３を折り返し突部６２の両側面に密着させ、垂平方向折り曲げ部６４と第２平板部６７とを密着させる。そして、図２に示す搬送用のロール５７により成形品を次工程に送り込む。
【００３５】
次に、本実施形態のロール成形の方法および装置による特徴を述べる。帯板Ｗの幅方向中央部に台形形状の突部６２ａを形成する第１ロール成形手段１１と、台形の上辺の幅を順次狭めて略三角形の突部６２ｃとしたのち突出した２辺の内側を密着させた折り返し突部６２を形成する第２ロール成形手段２１〜２７と、帯板Ｗの横幅方向両端に垂直方向折り曲げ部６３を形成する第３ロール成形手段３１、３２とを備える。
【００３６】
また、本実施形態での新規構成として、垂直方向折り曲げ部６３の先端部に更に略直角に折り曲げた垂平方向折り曲げ部６４を形成する第４ロール成形手段４１〜４５と、垂直方向折り曲げ部６３と折り返し突部６２との中間に断面半円状の周曲部６６を形成して第１平板部６５と第２平板部６７とを互いに平行にすると共に、垂直方向折り曲げ部６３を折り返し突部６２の両側面に密着させ、垂平方向折り曲げ部６４と第２平板部６７とを密着させる第５ロール成形手段５１〜５７とを備える。
【００３７】
このようなロール成形の方法および装置により、垂平方向折り曲げ部６４を持った偏平チューブ６０を成形することができる。また、第４ロール成形手段４１〜４５は、帯板Ｗを折り返し突部６２が突出する方向に湾曲させて垂平方向折り曲げ部６４を形成している。このようなロール成形の方法および装置により、垂直方向折り曲げ部６３から連続して更に略直角に形成した長方形状の垂平方向折り曲げ部６４を、アンダーカットとすることなく成形することができる。
また、第４ロール成形手段４１〜４５は、垂平方向折り曲げ部６４を形成した後、折り返し突部６２が突出する方向とは逆方向に湾曲させる矯正成形手段４５を含んでいる。このようなロール成形の方法および装置により、第１平板部６５と第２平板部６７とを略平行に設けることができると共に、接合部である折り返し突部６２と水直方向折り曲げ部６３との間、および垂平方向折り曲げ部６４と第２平板部６７との間を密着させて成形することができる。
【００３８】
（その他の実施形態）
図５は、本発明の他の実施形態における偏平チューブ６０の断面図である。図に示すように、補強部６１を折り返し突部ではなく１枚の短板部６８で形成した偏平チューブ６０においても、水平方向折り曲げ部６４を形成しても良く、上述した実施形態と同様の効果が得られる。
【図面の簡単な説明】
【図１】本発明の一実施形態における偏平チューブの断面図であり、（ａ）はロール成形後、（ｂ）はロウ付け後で充分なフィレットが形成されている補強部周りの部分断面図、（ｃ）はロウ付け後で充分なフィレットが形成されていない補強部周りの部分断面図である。
【図２】本発明の一実施形態におけるロール成形装置の各ロールの配置図である。
【図３】（ａ）〜（ｐ）は、本発明の一実施形態における各ロール成形工程での材料の成形態様を示す図である。
【図４】図３中本発明で新規となる第４ロール成形工程での材料の成形態様（ｈ）〜（ｌ）に対応する第４ロール成形手段での各ロールの型形状を示す図である。
【図５】本発明の他の実施形態における偏平チューブの断面図である。
【図６】従来の偏平チューブの断面図であり、（ａ）はロール成形後、（ｂ）はロウ付け後で充分なフィレットが形成されている補強部周りの部分断面図、（ｃ）はロウ付け後で充分なフィレットが形成されていない補強部周りの部分断面図である。
【符号の説明】
１１第１ロール成形工程、第１ロール成形手段
２１〜２７第２ロール成形工程、第２ロール成形手段
３１、３２第３ロール成形工程、第３ロール成形手段
４１〜４５第４ロール成形工程、第４ロール成形手段
４５矯正成形工程、矯正成形手段
５１〜５７第５ロール成形工程、第５ロール成形手段
６１補強部
６２折り返し突部
６２ａ台形形状の突部
６２ｃ略三角形の突部
６３水直方向折り曲げ部
６４垂平方向折り曲げ部
６５第１平板部
６６周曲部
６７第２平板部
Ｗ帯板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flat tube having a reinforcing portion in the center used for a heat exchanger or the like, and a method and apparatus for roll-forming the flat tube.
[0002]
[Prior art]
Conventionally, a flat tube that circulates a fluid for heat exchange is used in a heat exchanger such as a radiator for a vehicle or a hot water heater. FIG. 6 is a cross-sectional view of a conventional flat tube, and (a) shows a state after roll forming. As shown in the drawing, a flat tube 60 having a transverse θ shape in cross section provided with a reinforcing portion 61 at the center is provided so that the flat tube can be applied to a wide heat exchanger (see Japanese Patent Laid-Open No. 6-123571).
[0003]
The reinforcing portion 61 includes a horizontal direction bending portion 63 in which both ends of the plate material are bent vertically and a folding protrusion 62 formed by folding the central portion of the plate material into a mountain shape, and both portions 62 and 63 are joined by brazing. Has been. And this flat tube is brazed to the container (tank etc.) of a heat exchanger, and is used. Further, a roll forming method is known as a method for continuously forming a long member such as a flat tube in a cold manner for mass production.
[0004]
For example, in Japanese Patent Application Laid-Open No. 10-85877, a first roll forming step (means) for forming a trapezoidal protrusion at the center in the width direction of a strip by roll forming and the width of the upper side of the trapezoid are narrowed sequentially. A second roll forming step (means) for forming a substantially triangular protrusion, and then forming a folded protrusion in which the inner sides of the two protruding sides are in close contact with each other, and a vertical width equal to or less than the height of the folded protrusion at both ends in the lateral width direction of the strip A third roll forming step (means) for forming the direction bent portion, a half circle between the vertical bent portion and the turn-up protrusion, and the flat plate portions parallel to each other, and the vertical-fold portion of the turn-up protrusion There has been proposed a forming method and apparatus comprising a fourth roll forming step (means) for closely contacting both side surfaces.
[0005]
[Problems to be solved by the invention]
However, the bent shape described above is not a problem when the material plate thickness is in the range of about 0.25 to 0.3 mm. However, if the material plate thickness is thinner than that, for example, the material plate thickness is about 0.15 to 0.2 mm. At the time of attaching, the first horizontal direction bent portion 63 is deformed by thermal stress, and a gap between the folded protrusion 62 becomes large, and it is difficult to form a sufficient fillet.
[0006]
6B is a partial cross-sectional view around the reinforcing portion 61 where a sufficient fillet F is formed after brazing, and FIG. 6C is a portion around the reinforcing portion 61 where a sufficient fillet F is not formed after brazing. FIG. As shown in (c), if sufficient fillet F is not formed, there is a problem that the pressure resistance is lowered and leakage is likely to occur.
[0007]
The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to secure a pressure-resistant strength and to generate leakage in a flat tube having a reinforcing portion having a protruding portion folded in the center. It is an object of the present invention to provide a flat tube that is difficult to perform and a roll forming method and apparatus therefor.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the technical means described in claims 1 to 7 are employed. That is, in the invention according to claim 1, a flat tube having a cross section having a transverse θ shape and a reinforcing portion (61) in the center by sequentially bending a long strip (W),
One rectangular bent portion (64) having one rectangular shape, and one horizontal bent portion (63) formed substantially at a right angle continuously from the long side of the vertically bent portion (64), One flat plate-like first flat plate portion (65) formed substantially perpendicular to the horizontal direction bent portion (63) and one cross-section half formed continuously from the first flat plate portion (65). A circular peripheral portion (66) and one flat second plate portion (67) formed continuously from the peripheral portion (66) and provided substantially parallel to the first flat plate portion (65). And a rectangular folded protrusion (62) that is continuously folded from the second flat plate portion (67) at a substantially right angle and provided adjacent to the horizontal direction folded portion (63) substantially in parallel. Continuously perpendicular to the direction of facing the second flat plate portion (67) from the folded protrusion (62). The other flat plate-like second flat plate portion (67), the other semicircular circumferential portion (66) formed continuously from the second flat plate portion (67), and the circumferential portion (66 ), The other flat plate-like first flat plate portion (65) provided substantially parallel to the second flat plate portion (67), and the first flat plate portion (65) continuously at a substantially right angle. The other vertical bent portion (63) provided adjacent to and substantially parallel to the turn-up protrusion (62) is formed at a substantially right angle continuously from the vertical bent portion (63). Two flat plate portions (67) and the other rectangular-shaped vertical bending portion (64) provided substantially in parallel,
While the folding projection (62) is folded, the vertical folding portion (64) provided between the folding projection (62) and the horizontal direction folding portion (63) provided adjacent to each other and adjacent to each other. ) And the second flat plate portion (67), the horizontal direction bent portion (63), the vertical direction bent portion (64), the first flat plate portion (65), the peripheral bent portion (66), and A space surrounded by the second flat plate portion (67) forms a flow path through which the heat exchange fluid flows.
[0009]
FIG. 1 is a cross-sectional view of a flat tube 60 according to an embodiment of the present invention, where (a) shows a portion around a reinforcing portion 61 where a sufficient fillet F is formed after roll forming and (b) after brazing. Sectional view (c) is a partial sectional view around reinforcing portion 61 where a sufficient fillet F is not formed after brazing.
[0010]
Even if sufficient fillet F is not formed as shown in (c), it is between the folding projection (62) and the horizontal direction bent portion (63), and the vertical direction bent portion (64) and the second flat plate portion ( 67), it is possible to secure a pressure-resistant strength even if thermal deformation occurs, and to obtain a flat tube that is less likely to leak.
[0011]
In the invention according to claim 2, a flat tube for forming a flat tube having a transverse θ shape in cross section and a reinforcing portion (61) in the center by sequentially bending a long strip (W). A roll forming method,
A first roll forming step (11) for forming a trapezoidal protrusion (62a) at the center in the width direction of the band plate (W), and a substantially triangular protrusion (62c) by sequentially reducing the width of the upper side of the trapezoid. After that, the second roll forming step (21 to 27) for forming the folded protrusion (62) in which the inner sides of the two protruding sides are brought into close contact with each other, and the vertical bent portion (63) at both lateral width direction ends of the strip (W). And a fourth roll forming step (41) for forming a vertical bent portion (64) further bent at a substantially right angle at the tip of the vertical bent portion (63). ˜45), and a first flat plate portion (65) and a second flat plate portion by forming a semicircular circumferential curved portion (66) between the vertical bent portion (63) and the folded protrusion (62). (67) are parallel to each other, and the vertical fold (63) is folded. It is characterized by comprising a fifth roll forming step (51-57) in close contact with both side surfaces of the protrusion (62) and in close contact with the vertical bent portion (64) and the second flat plate portion (67). To do.
[0012]
By such a roll forming method, a flat tube having a vertical direction bent portion (64) can be formed.
[0013]
In the invention according to claim 3, in the fourth roll forming step (41 to 45), the band plate (W) is bent in the direction in which the folded protrusion (62) protrudes and the vertical direction bent part (64) is formed. It is characterized by forming. By such a roll forming method, the rectangular vertical bent portion (64) formed at a substantially right angle continuously from the vertical bent portion (63) can be formed without undercutting.
[0014]
In the invention according to claim 4, in the fourth roll forming step (41 to 45), after forming the vertical bent portion (64), the curve is made in the direction opposite to the direction in which the folded protrusion (62) protrudes. It is characterized by including an orthodontic molding step (45). By such a roll forming method, the first flat plate portion (65) and the second flat plate portion (67) can be provided substantially in parallel, and the folded protrusion (62) which is a joint portion and the horizontal direction bent portion. (63) and between the vertical bent portion (64) and the second flat plate portion (67) can be molded.
[0015]
In the invention according to claim 5, a flat tube for forming a flat tube having a transverse θ shape in section and having a reinforcing portion (61) in the center by sequentially bending a long strip (W). A roll forming device,
A first roll forming means (11) for forming a trapezoidal protrusion (62a) at the center in the width direction of the band plate (W), and a substantially triangular protrusion (62c) by narrowing the width of the upper side of the trapezoid sequentially. After that, the second roll forming means (21 to 27) for forming the folded protrusions (62) in which the inner sides of the two protruding sides are in close contact with each other, and the vertical bent portions (63) at both ends in the lateral width direction of the strip (W). And a fourth roll forming means (41) for forming a vertical-direction bent portion (64) which is further bent at a substantially right angle at the tip of the vertical-direction bent portion (63). ˜45), and a first flat plate portion (65) and a second flat plate portion by forming a semicircular circumferential curved portion (66) between the vertical bent portion (63) and the folded protrusion (62). (67) are parallel to each other, and the vertical fold (63) is folded. It is characterized by comprising fifth roll forming means (51-57) which are brought into close contact with both side surfaces of the protrusion (62), and which brings the vertical bent portion (64) and the second flat plate portion (67) into close contact with each other. To do.
[0016]
By such a roll forming apparatus, a flat tube having a vertical direction bent portion (64) can be formed.
[0017]
In the invention according to claim 6, the fourth roll forming means (41 to 45) bends the strip plate (W) in the direction in which the folded protrusion (62) protrudes to form the vertical bent portion (64). It is characterized by forming. By such a roll forming apparatus, the rectangular vertical bent part (64) formed at a substantially right angle continuously from the vertical bent part (63) can be formed without undercutting.
[0018]
In the invention according to claim 7, the fourth roll forming means (41 to 45) bends in the direction opposite to the direction in which the folded protrusion (62) protrudes after forming the vertical direction bent part (64). It is characterized by including a correction molding means (45) to be made.
[0019]
With such a roll forming apparatus, the first flat plate portion (65) and the second flat plate portion (67) can be provided substantially in parallel, and the folded protrusion (62) which is a joint portion and the horizontal direction bent portion. (63) and between the vertical bent portion (64) and the second flat plate portion (67) can be molded. Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with the specific means described in the embodiments described later.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a flat tube 60 according to an embodiment of the present invention, and (a) shows a shape after roll forming. The flat tube 60 is a heat exchanger such as a radiator for a vehicle or a hot water heater, and is used to circulate a fluid for heat exchange, and is formed by bending a plate material such as brass or aluminum having good heat conduction. Is done.
[0021]
Specifically, it is a flat tube in which a single long strip is sequentially bent and a reinforcing portion 61 is provided in the center having a cross section having a horizontal θ shape. One rectangular-shaped bent portion 64 and one horizontal-folded portion 63 formed substantially at right angles continuously from the long side of the bent portion 64 are provided. Also, one flat plate-like first flat plate portion 65 formed substantially perpendicular to the straight direction bent portion 63 and one of the semicircular cross sections formed continuously from the first flat plate portion 65. It has a circumferential portion 66.
[0022]
Also, one flat plate-like second flat plate portion 67 formed continuously from the peripheral curved portion 66 and provided substantially in parallel with the first flat plate portion 65, and substantially continuous from the second flat plate portion 67. It has a rectangular folded protrusion 62 which is formed to be folded at a right angle, and is provided adjacent to and substantially parallel to the previous straight direction folded section 63. In addition, the other flat plate-like second flat plate portion 67 that extends from the turn-up protrusion 62 and extends in a direction substantially perpendicular to the direction facing the second flat plate portion 67 is formed continuously from the second flat plate portion 67. And a curved portion 66 having a semicircular cross section.
[0023]
Further, the other flat plate-like first flat plate portion 65 formed continuously from the circumferentially curved portion 66 and provided substantially in parallel with the second flat plate portion 67, and continuously from the first flat plate portion 65. It is formed at a substantially right angle, and has the other vertical bent portion 63 provided adjacent to and substantially parallel to the previous folded protrusion 62. In addition, the second bent portion 64 is formed at a substantially right angle continuously from the vertical bent portion 63 and has the other rectangular flat bent portion 64 provided substantially in parallel with the second flat plate portion 67.
[0024]
Then, while the previous folding projection 62 is folded, between the previous folding projection 62 and the previous horizontal direction bending section 63 provided adjacent to each other, and the previous vertical direction provided adjacent to each other. The bent portion 64 and the second flat plate portion 67 are joined. Thus, the space surrounded by the horizontal direction bent portion 63, the vertical direction bent portion 64, the first flat plate portion 65, the circumferential bent portion 66, and the second flat plate portion 67 is a flow path through which the heat exchange fluid flows. Become.
[0025]
As a result, even if a sufficient fillet F is not formed at the joint portion, the gap between the folding projection 62 and the horizontal direction bending portion 63 and between the vertical direction bending portion 64 and the second flat plate portion 67 is reduced. By joining at the places, the flat tube 60 can be obtained, which can secure the pressure strength even when thermal deformation occurs, and hardly leak.
[0026]
Next, a method and apparatus for roll forming such a flat tube 60 will be described. FIG. 2 is a layout diagram of the rolls 11 to 57 of the roll forming apparatus 1 according to the embodiment of the present invention. 3 (a) to 3 (p) are diagrams showing a molding mode of the material in each roll molding step in one embodiment of the present invention, and FIG. It is a figure which shows the mold shape of each roll 41-45 in the 4th roll shaping | molding means corresponding to the shaping | molding aspect (h)-(l) of the material in a 4-roll shaping | molding process.
[0027]
2 of FIG. 2 is a roll forming of a flat tube in which a single long strip W (FIG. 3) is sequentially bent to form a flat tube 60 having a transverse θ shape in cross section and a reinforcing portion 61 in the center. Device. As shown in FIG. 2, the roll forming apparatus 1 has roll forming means 11 to 24, 27, 41 to 45, and 51 to 57 in which the rotational axis of the roll is horizontal, and the rotational axis of the roll is vertical. It comprises roll forming means 25 and 26.
[0028]
First, as shown in FIG. 3A, a trapezoidal protrusion 62 a having a large upper side is formed by the roll forming means 11. Then, the roll forming means 21 to 23 sequentially reduce the width of the upper side of the trapezoid as shown in FIG. Then, as shown in FIG. 3C, the roll forming means 24 forms a protrusion 62c having a triangular shape.
[0029]
Next, as shown in FIG. 3 (d), the inner sides of the two protruding sides of the protrusion 62c are brought into close contact with each other by the roll forming means 25 and 26 whose roll rotation axis is vertical, thereby forming the folded protrusion 62d. . Subsequently, the roll forming means 27 whose roll rotation axis is horizontal is installed and pressed from above to turn the folding protrusion 62d to reduce the radius of curvature of the curved portion, thereby forming a square shape, and the folding protrusion shown in FIG. A portion 62 is formed.
[0030]
Next, as shown in FIG. 3 (f), both end portions of the intermediate molded body on which the folded protrusions 62 are formed by the roll forming means 31 are bent at an angle of 45 ° to form a bent portion 63a. Subsequently, as shown in FIG. 3G, the bent portion 63 a is bent in the vertical direction by the roll forming means 32 to form the vertical bent portion 63.
[0031]
Next, as a new configuration in the present embodiment, as shown in FIGS. 3H to 3L, a vertical-direction bent portion 64 that is further bent at a substantially right angle is formed at the tip of the vertical-direction bent portion 63. There are fourth roll forming means 41-45. First, as shown in FIG. 3 (h), the roll forming means 41 causes the intermediate molded body to bend in the direction in which the folded projection 62 protrudes, and at an angle of 45 ° to the tip of the vertical folded portion 63. A bent portion 64a is formed.
[0032]
Next, as shown in FIG. 3 (i), the intermediate molded body is further curved in the direction in which the folded projection 62 protrudes by the roll molding means 42, and further at a substantially right angle to the tip of the vertical folding section 63. The folded horizontal direction bent portion 64 is formed. Next, as shown in FIGS. 3 (j) and 3 (k), the curve of the intermediate molded body is returned to the flat plate by roll forming means 43 and 44, and as shown in FIG. The correction molding process is such that the intermediate molded body is bent in the direction opposite to the direction in which the folded protrusion 62 projects.
[0033]
Next, as shown in FIG. 3 (m), the middle of the vertical bent portion 63 and the folded protrusion 62 is bent at 30 ° by the roll forming means 51. Subsequently, as shown in FIGS. 3 (n) and 3 (o), the roll forming means 52 to 55 set the middle between the vertical bent portion 63 and the folded protrusion 62 to 60 ° (not shown), 90 °, and 120. Bend sequentially to ° · 150 ° (not shown).
[0034]
Then, as shown in FIG. 3 (p), the first flat plate portion 65 and the second flat plate portion 67 are finally made parallel to each other by the forming roll 56, and the vertical bent portion 63 is formed on both side surfaces of the folded protrusion 62. And the vertical direction bent portion 64 and the second flat plate portion 67 are brought into close contact with each other. Then, the molded product is fed into the next process by the transporting roll 57 shown in FIG.
[0035]
Next, features of the roll forming method and apparatus of this embodiment will be described. The first roll forming means 11 for forming a trapezoidal protrusion 62a at the center in the width direction of the band W, and the inner side of the two sides protruding after narrowing the width of the upper side of the trapezoid in order to form a substantially triangular protrusion 62c Are provided with second roll forming means 21 to 27 for forming the folded protrusions 62 closely attached to each other, and third roll forming means 31 and 32 for forming the vertical bent parts 63 at both ends in the widthwise direction of the strip W.
[0036]
Further, as a new configuration in the present embodiment, fourth roll forming means 41 to 45 for forming a vertical direction bent portion 64 which is further bent at a substantially right angle at a tip portion of the vertical direction bent portion 63, and the vertical direction bent portion 63. And a turn-up projection 62 are formed between the first and second flat plate portions 65 and 67 in parallel with each other, and the vertical turn-up portion 63 is turned up. Fifth roll forming means 51 to 57 are provided which are brought into close contact with both side surfaces of 62 and make the vertical bent portion 64 and the second flat plate portion 67 in close contact with each other.
[0037]
By such a roll forming method and apparatus, the flat tube 60 having the vertical bent portion 64 can be formed. Moreover, the 4th roll shaping | molding means 41-45 curves the strip W in the direction where the folding | turning protrusion 62 protrudes, and forms the horizontal direction bending part 64. FIG. By such a roll forming method and apparatus, the rectangular vertical bent portion 64 continuously formed at a substantially right angle from the vertical bent portion 63 can be formed without undercutting.
Moreover, the 4th roll shaping | molding means 41-45 contains the correction shaping | molding means 45 made to curve in the direction opposite to the direction where the folding | turning protrusion 62 protrudes, after forming the horizontal direction bending part 64. FIG. By such a roll forming method and apparatus, the first flat plate portion 65 and the second flat plate portion 67 can be provided substantially parallel to each other, and the folded protrusion 62 and the horizontal direction bent portion 63, which are joint portions, are provided. And between the vertical bent portion 64 and the second flat plate portion 67 can be formed.
[0038]
(Other embodiments)
FIG. 5 is a cross-sectional view of a flat tube 60 according to another embodiment of the present invention. As shown in the figure, the horizontal bent portion 64 may be formed in the flat tube 60 in which the reinforcing portion 61 is formed not by the folded protrusion but by the single short plate portion 68, which is the same as the above-described embodiment. An effect is obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a flat tube according to an embodiment of the present invention, in which (a) is a partial cross-sectional view around a reinforcing portion where a sufficient fillet is formed after roll forming and (b) is brazed. , (C) is a partial cross-sectional view around a reinforcing portion where a sufficient fillet is not formed after brazing.
FIG. 2 is a layout view of each roll of the roll forming apparatus according to the embodiment of the present invention.
FIGS. 3A to 3P are views showing a molding mode of a material in each roll molding step in one embodiment of the present invention.
FIG. 4 is a view showing the mold shape of each roll in the fourth roll forming means corresponding to the material forming modes (h) to (l) in the fourth roll forming step which is novel in the present invention in FIG. 3; is there.
FIG. 5 is a cross-sectional view of a flat tube according to another embodiment of the present invention.
6A and 6B are cross-sectional views of a conventional flat tube, in which FIG. 6A is a partial cross-sectional view around a reinforcing portion where a sufficient fillet is formed after roll forming, FIG. It is a fragmentary sectional view around the reinforcement part in which sufficient fillet is not formed after brazing.
[Explanation of symbols]
11 1st roll forming process, 1st roll forming means 21-27 2nd roll forming process, 2nd roll forming means 31, 32 3rd roll forming process, 3rd roll forming means 41-45 4th roll forming process, 1st 4 roll forming means 45 Straightening forming process, straightening forming means 51 to 57 Fifth roll forming process, fifth roll forming means 61 Reinforcement part 62 Folding protrusion 62a Trapezoidal protrusion 62c Substantially triangular protrusion 63 Bending in the horizontal direction Part 64 Vertical direction bending part 65 1st flat plate part 66 Circumflex part 67 2nd flat plate part W Band plate

Claims

長尺の１枚の帯板（Ｗ）を順次折り曲げて断面が横θ形状を有し中央に補強部（６１）を備えた偏平チューブであって、
一方の長方形状の垂平方向折り曲げ部（６４）と、
この垂平方向折り曲げ部（６４）の長辺から連続して略直角に形成された一方の水直方向折り曲げ部（６３）と、
この水直方向折り曲げ部（６３）から連続にして略直角に形成された一方の平板状の第１平板部（６５）と、
この第１平板部（６５）から連続に形成された一方の断面半円状の周曲部（６６）と、
この周曲部（６６）から連続に形成され、前記第１平板部（６５）と略平行に設けられた一方の平板状の第２平板部（６７）と、
この第２平板部（６７）から連続にして略直角に折り返し形成され、前記水直方向折り曲げ部（６３）と略平行に隣接して設けられた長方形状の折り返し突部（６２）と、
この折り返し突部（６２）から連続にして前記第２平板部（６７）と対向する方向へ略直角に延びる他方の平板状の第２平板部（６７）と、
この第２平板部（６７）から連続に形成された他方の断面半円状の周曲部（６６）と、
この周曲部（６６）から連続して形成され、前記第２平板部（６７）と略平行に設けられた他方の平板状の第１平板部（６５）と、
この第１平板部（６５）から連続して略直角に形成され、前記折り返し突部（６２）と略平行に隣接して設けられた他方の垂直方向折り曲げ部（６３）と、
この垂直方向折り曲げ部（６３）から連続して略直角に形成され、前記第２平板部（６７）と略平行に設けられた他方の長方形状の垂平方向折り曲げ部（６４）とを備え、
前記折り返し突部（６２）の折り返した間、隣接して設けられた前記折り返し突部（６２）と前記水直方向折り曲げ部（６３）との間、および隣接して設けられた前記垂平方向折り曲げ部（６４）と前記第２平板部（６７）との間を接合し、前記水直方向折り曲げ部（６３）、前記垂平方向折り曲げ部（６４）、前記第１平板部（６５）、前記周曲部（６６）、および前記第２平板部（６７）とで囲まれた空間が前記熱交換流体の流通する流路を形成することを特徴とする偏平チューブ。A flat tube in which a long strip (W) is sequentially bent and the cross section has a transverse θ shape and a reinforcing portion (61) in the center,
One rectangular-shaped vertical bent portion (64);
One horizontal direction bent portion (63) formed substantially at right angles continuously from the long side of the vertical direction bent portion (64),
One flat plate-shaped first flat plate portion (65) formed substantially perpendicular to the straight direction bent portion (63),
One circumferential semicircular section (66) formed continuously from the first flat plate section (65);
One flat plate-like second flat plate portion (67) formed continuously from the circumferentially curved portion (66) and provided substantially parallel to the first flat plate portion (65),
A rectangular folded protrusion (62) formed continuously and substantially perpendicularly to the second flat plate portion (67) and provided adjacent to the horizontal direction folded portion (63) substantially in parallel.
The other flat plate-like second flat plate portion (67) extending substantially perpendicular to the direction facing the second flat plate portion (67) continuously from the turn-up protrusion (62);
The other circumferential semicircular curved portion (66) formed continuously from the second flat plate portion (67);
The other flat plate-shaped first flat plate portion (65) formed continuously from the circumferential curved portion (66) and provided substantially parallel to the second flat plate portion (67),
The other vertical bent portion (63) formed substantially at right angles continuously from the first flat plate portion (65) and provided adjacent to and substantially parallel to the folded protrusion (62);
The other vertical rectangular bent portion (64) formed substantially perpendicular to the vertical bent portion (63) and provided substantially parallel to the second flat plate portion (67),
While the folding projection (62) is folded, the vertical direction is provided between and adjacent to the folding projection (62) and the horizontal direction folding portion (63). Between the bent portion (64) and the second flat plate portion (67), the horizontal direction bent portion (63), the vertical direction bent portion (64), the first flat plate portion (65), A flat tube characterized in that a space surrounded by the circumferentially curved portion (66) and the second flat plate portion (67) forms a flow path through which the heat exchange fluid flows.

長尺の１枚の帯板（Ｗ）を順次折り曲げて断面が横θ形状を有し中央に補強部（６１）を備えた偏平チューブを成形する偏平チューブのロール成形方法であって、
前記帯板（Ｗ）の幅方向中央部に台形形状の突部（６２ａ）を形成する第１ロール成形工程（１１）と、
前記台形の上辺の幅を順次狭めて略三角形の突部（６２ｃ）としたのち突出した２辺の内側を密着させた折り返し突部（６２）を形成する第２ロール成形工程（２１〜２７）と、
前記帯板（Ｗ）の横幅方向両端に垂直方向折り曲げ部（６３）を形成する第３ロール成形工程（３１、３２）と、
前記垂直方向折り曲げ部（６３）の先端部に更に略直角に折り曲げた垂平方向折り曲げ部（６４）を形成する第４ロール成形工程（４１〜４５）と、
前記垂直方向折り曲げ部（６３）と前記折り返し突部（６２）との中間に断面半円状の周曲部（６６）を形成して第１平板部（６５）と第２平板部（６７）とを互いに平行にすると共に、前記垂直方向折り曲げ部（６３）を前記折り返し突部（６２）の両側面に密着させ、前記垂平方向折り曲げ部（６４）と前記第２平板部（６７）とを密着させる第５ロール成形工程（５１〜５７）とからなることを特徴とする偏平チューブのロール成形方法。A flat tube roll forming method in which a single long strip (W) is sequentially bent to form a flat tube having a transverse θ shape in cross section and a reinforcing portion (61) in the center,
A first roll forming step (11) for forming a trapezoidal protrusion (62a) at the center in the width direction of the strip (W);
A second roll forming step (21-27) for forming a turn-up protrusion (62) in which the width of the upper side of the trapezoid is successively reduced to form a substantially triangular protrusion (62c), and the two protruding sides are in close contact with each other. When,
A third roll forming step (31, 32) for forming vertical bent portions (63) at both lateral ends of the strip (W);
A fourth roll forming step (41-45) for forming a vertical direction bent portion (64) bent further at a substantially right angle at the tip of the vertical direction bent portion (63);
A first flat plate portion (65) and a second flat plate portion (67) are formed by forming a semicircular curved portion (66) having a semicircular cross section between the vertical bent portion (63) and the folded protrusion (62). Are parallel to each other, and the vertical bent portion (63) is brought into close contact with both side surfaces of the folded protrusion (62), and the vertical bent portion (64) and the second flat plate portion (67) A flat tube roll forming method, comprising: a fifth roll forming step (51 to 57) for tightly contacting the flat tube.

前記第４ロール成形工程（４１〜４５）は、前記帯板（Ｗ）を前記折り返し突部（６２）が突出する方向に湾曲させて前記垂平方向折り曲げ部（６４）を形成することを特徴とする請求項２に記載の偏平チューブのロール成形方法。In the fourth roll forming step (41 to 45), the band plate (W) is bent in a direction in which the folded protrusion (62) protrudes to form the vertical direction bent part (64). The roll forming method for a flat tube according to claim 2.

前記第４ロール成形工程（４１〜４５）は、前記垂平方向折り曲げ部（６４）を形成した後、前記折り返し突部（６２）が突出する方向とは逆方向に湾曲させる矯正成形工程（４５）を含んでいることを特徴とする請求項２または請求項３に記載の偏平チューブのロール成形方法。In the fourth roll forming step (41 to 45), after forming the vertical direction bent portion (64), the straight forming step (45) for bending in the direction opposite to the direction in which the folded protrusion (62) protrudes. 4. The flat tube roll forming method according to claim 2, wherein:

長尺の１枚の帯板（Ｗ）を順次折り曲げて断面が横θ形状を有し中央に補強部（６１）を備えた偏平チューブを成形する偏平チューブのロール成形装置であって、
前記帯板（Ｗ）の幅方向中央部に台形形状の突部（６２ａ）を形成する第１ロール成形手段（１１）と、
前記台形の上辺の幅を順次狭めて略三角形の突部（６２ｃ）としたのち突出した２辺の内側を密着させた折り返し突部（６２）を形成する第２ロール成形手段（２１〜２７）と、
前記帯板（Ｗ）の横幅方向両端に垂直方向折り曲げ部（６３）を形成する第３ロール成形手段（３１、３２）と、
前記垂直方向折り曲げ部（６３）の先端部に更に略直角に折り曲げた垂平方向折り曲げ部（６４）を形成する第４ロール成形手段（４１〜４５）と、
前記垂直方向折り曲げ部（６３）と前記折り返し突部（６２）との中間に断面半円状の周曲部（６６）を形成して第１平板部（６５）と第２平板部（６７）とを互いに平行にすると共に、前記垂直方向折り曲げ部（６３）を前記折り返し突部（６２）の両側面に密着させ、前記垂平方向折り曲げ部（６４）と前記第２平板部（６７）とを密着させる第５ロール成形手段（５１〜５７）とからなることを特徴とする偏平チューブのロール成形装置。A flat tube roll forming apparatus for sequentially bending a long strip (W) and forming a flat tube having a transverse θ shape in cross section and having a reinforcing portion (61) in the center,
First roll forming means (11) for forming a trapezoidal protrusion (62a) at the center in the width direction of the strip (W);
Second roll forming means (21-27) for forming folded projections (62) in which the widths of the upper sides of the trapezoid are successively narrowed to form substantially triangular projections (62c), and the two projected sides are in close contact with each other. When,
Third roll forming means (31, 32) for forming vertical bent portions (63) at both lateral ends of the strip (W);
Fourth roll forming means (41 to 45) for forming a vertical direction bent portion (64) bent further substantially at a right angle at a tip portion of the vertical direction bent portion (63);
A first flat plate portion (65) and a second flat plate portion (67) are formed by forming a semicircular curved portion (66) having a semicircular cross section between the vertical bent portion (63) and the folded protrusion (62). Are parallel to each other, and the vertical bent portion (63) is brought into close contact with both side surfaces of the folded protrusion (62), and the vertical bent portion (64) and the second flat plate portion (67) A flat tube roll forming apparatus, characterized by comprising fifth roll forming means (51 to 57) for tightly contacting each other.

前記第４ロール成形手段（４１〜４５）は、前記帯板（Ｗ）を前記折り返し突部（６２）が突出する方向に湾曲させて前記垂平方向折り曲げ部（６４）を形成することを特徴とする請求項５に記載の偏平チューブのロール成形装置。The fourth roll forming means (41 to 45) bends the strip (W) in a direction in which the folded protrusion (62) protrudes to form the vertical direction bent part (64). The flat tube roll forming apparatus according to claim 5.

前記第４ロール成形手段（４１〜４５）は、前記垂平方向折り曲げ部（６４）を形成した後、前記折り返し突部（６２）が突出する方向とは逆方向に湾曲させる矯正成形手段（４５）を含んでいることを特徴とする請求項５または請求項６に記載の偏平チューブのロール成形装置。The fourth roll forming means (41 to 45) is a correction forming means (45) which, after forming the vertical direction bent portion (64), curves in a direction opposite to the direction in which the folded protrusion (62) protrudes. The flat tube roll forming apparatus according to claim 5 or 6, wherein the flat tube roll forming apparatus includes: