JP3644054B2

JP3644054B2 - Refrigerant evaporator

Info

Publication number: JP3644054B2
Application number: JP24365994A
Authority: JP
Inventors: 恵津夫長谷川; 聡也長沢
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1994-10-07
Filing date: 1994-10-07
Publication date: 2005-04-27
Anticipated expiration: 2020-04-27
Also published as: JPH08110124A

Description

【０００１】
【産業上の利用分野】
本発明は冷媒通路を金属薄板の積層構造により形成する積層型の冷媒蒸発器に関するもので、特に冷媒通路内を流れる内部冷媒同志で熱交換を行う副熱交換部を有する積層型の冷媒蒸発器に関する。
【０００２】
【従来の技術】
本出願人は、特開平５−１９６３２１号公報において、冷媒通路内を流れる内部冷媒同志で熱交換を行う副熱交換部を有する積層型の蒸発器を提案している。
上記公報記載のものは、通常の冷媒−空気間の熱交換をおこなう主熱交換部の他に、蒸発器入口側の冷媒と蒸発器出口側の冷媒とを熱交換させて、主熱交換部の入口タンク内に流入する冷媒の乾き度を小さくする、副熱交換部（冷媒−冷媒熱交換部）を設けている。
【０００３】
この副熱交換部の作用により主熱交換部の入口タンク内に流入する冷媒の乾き度を大幅に小さくして、入口タンク内における冷媒が液単相に近い状態にすることにより、入口タンクから多数のチューブに冷媒を分配する際に、各チューブに均一に液冷媒を分配できる。しかも、各チューブ内面が液冷媒で覆われた状態となり、チューブ内面での熱伝達率が向上し、これらのことが相まって蒸発器の冷却性能を向上できるものである。
【０００４】
【発明が解決しようとする課題】
ところで、本発明者らの実験検討によれば、上記公報記載のものでは、その製造に際して、副熱交換部（冷媒−冷媒熱交換部）を持つことに起因する冷媒内部洩れという特有の問題が生じることが分かった。すなわち、性能向上の心臓部となる副熱交換部（冷媒−冷媒熱交換部）にてろう付け不良等が生じると、蒸発器の入口側冷媒と出口側冷媒とが直接混合してしまう状態、つまり、副熱交換部の冷媒通路相互間での冷媒洩れ（以下内部洩れという）が発生することがある。この内部洩れが一旦発生すると、蒸発器の冷却性能が低下するのみならず、この蒸発器を用いた空調用冷凍サイクルが制御不能になる場合もある。
【０００５】
ところで、蒸発器の入口側と出口側は本来、主熱交換部の冷媒通路を介して連通しているので、上記内部洩れの発生状態と、主熱交換部の冷媒通路を介した正規の連通状態との区別ができないので、上記内部洩れの有無を従来確認することができなかった。
本発明は上記点に鑑みてなされたもので、冷媒通路内を流れる内部冷媒同志で熱交換を行う副熱交換部を有する積層型熱交換器において、内部洩れの有無を的確に検知できるようにすることを目的とする。
【０００６】
また、本発明の他の目的は、蒸発器のコアサイズの変更（チューブ積層段数の変更、コア部長さの変更）に対しても、主熱交換部の複数チューブへの冷媒分配性を簡単な構成変更で容易に対応できる冷媒蒸発器を提供することを目的とする。
【０００７】
【課題を解決するための手段】
本発明は上記目的を達成するため、以下の技術的手段を採用する。
請求項１記載の発明では、冷媒通路（７ａ）内を流れる冷媒と前記冷媒通路（７ａ）の外部を流れる被冷却流体とを熱交換させる主熱交換部（７）と、
前記主熱交換部（７）の冷媒通路（７ａ）の入口側に流入する冷媒と、前記主熱交換部（７）の冷媒通路（７ａ）の出口側から流出する冷媒とを熱交換させる副熱交換部（８）とを有し、
前記主及び副熱交換部（７、８）の冷媒通路（７ａ）は金属薄板（７ｂ、８ｃ）の積層構造により形成されており、
前記副熱交換部（８）において、前記主熱交換部（７）の冷媒通路（７ａ）の入口部（７ｃ）に対向する部位に、冷媒入口穴（１６）、およびこの冷媒入口穴（１６）を閉塞可能な検査治具（１７）を挿入するための治具挿入穴（１９）が設けられており、
この治具挿入穴（１９）には、この穴を密封するための密封部材（２０）が装着されており、
さらに前記冷媒入口穴（１６）の冷媒出口側に、前記冷媒入口穴部分とは別体で形成されたノズル（２１）が配置されている冷媒蒸発器を特徴としている。
【０００８】
請求項２記載の発明では、請求項１に記載の冷媒蒸発器において、前記冷媒入口穴（１６）は、前記副熱交換部（８）のうち前記主熱交換部（７）側端部に配置された中間プレート（１４）に設けられており、
また前記治具挿入穴（１９）は、前記副熱交換部（８）のうち前記主熱交換部（７）とは反対側の端部に配置された端板（１２）に設けられていることを特徴とする。
【０００９】
請求項３記載の発明では、請求項１または２に記載の冷媒蒸発器において、前記ノズル（２１）は、その先端部が前記主熱交換部（７）の冷媒通路（７ａ）の入口部（７ｃ）内に挿入されるように配置されていることを特徴とする。
請求項４記載の発明では、請求項１ないし３のいずれか１つに記載の冷媒蒸発器において、前記ノズル（２１）は非円形の絞り穴（２１ｂ）を有しており、
この非円形の絞り穴（２１ｂ）の方向が所定方向に向くように前記ノズル（２１）が前記冷媒入口穴（１６）に対して位置決めして固定されるようにしたことを特徴とする。
【００１０】
なお、上記各手段の括弧内の符号は、後述する実施例記載の具体的手段との対応関係を示すものである。
【００１１】
【発明の作用効果】
請求項１〜４記載の発明によれば、上記技術的手段を有しているため、主熱交換部の冷媒通路と副熱交換部の冷媒通路との連通状態を検査治具により遮断して、副熱交換部の冷媒通路相互間の内部洩れの検査を確実に実施できる積層型の冷媒蒸発器を提供できる。
【００１２】
しかも、前記冷媒入口穴の冷媒出口側に、前記冷媒入口穴部分とは別体で形成されたノズルを配置しているから、冷媒出口穴の形状は検査治具により閉塞しやすい円形状としても、別体のノズルにて主熱交換部の多数の冷媒通路への冷媒分配性を最適化する非円形の形状を自由に設定できる。
従って、本発明では、蒸発器のコアサイズの変更に対しても、別体ノズルの変更という簡単な構成変更で、最適な冷媒分配性を確保できる。
【００１３】
【実施例】
以下、本発明を図に示す実施例について説明する。図１は本発明による冷媒蒸発器を適用した自動車用空調装置の冷凍サイクルを示しており、１は圧縮機で、電磁クラッチ２を介して自動車用エンジン（駆動源、図示せず）により駆動されるものである。３は凝縮器で、圧縮機１から吐出された高温、高圧のガス冷媒を冷却ファン（図示せず）の送風空気と熱交換して冷却し、凝縮するものである。
【００１４】
４は凝縮器３で凝縮した液冷媒を溜めて液冷媒のみをサイクル下流側へ導出する受液器、５は冷媒の減圧手段を構成する温度作動式膨張弁で、５ａはその感温筒である。６は本発明による積層型の冷媒蒸発器である。
この蒸発器６は、冷媒通路７ａ内を流れる冷媒と前記冷媒通路７ａの外部を流れる空調用送風空気（被冷却流体）とを熱交換させる主熱交換部７と、
この主熱交換部７の冷媒通路７ａの入口側に流入する冷媒と、前記主熱交換部７の冷媒通路７ａの出口側から流出する冷媒とを熱交換させる副熱交換部８とを有している。
【００１５】
ここで、副熱交換部８において、８ａは前記主熱交換部７の冷媒通路７ａの入口側に流入する冷媒が流れる入口側冷媒通路を示し、８ｂは前記主熱交換部７の冷媒通路７ａの出口側から流出する冷媒が流れる出口側冷媒通路を示す。従って、副熱交換部８は冷媒−冷媒熱交換部を構成することになる。一方、主熱交換部７は送風空気から冷媒が吸熱して蒸発する冷媒蒸発部（冷媒−空気熱交換部）を構成することになる。
【００１６】
９は副熱交換部８の入口側冷媒通路８ａと主熱交換部７の冷媒通路７ａの入口部との間に蛇行状に形成された微小断面積の絞り通路で、一般にキャピラリチューブと称されている減圧手段の役割を果たす。但し、この絞り通路９による減圧度合いは膨張弁５の減圧度合いよりも小さく設定されており、この絞り通路９はその上流側と下流側との間に冷媒の圧力差を設けて、副熱交換部８における入口側冷媒通路８ａの冷媒温度と、出口側冷媒通路８ｂの冷媒温度との間に、高低の温度差をつけることにより、両通路８ａ、８ｂ間の熱交換を良好に行わせるものである。
【００１７】
１０は定圧弁で、冬季の如く冷凍サイクル熱負荷が著しく低下して、その前後の圧力差が設定値以下になると、開弁して受液器４からの液冷媒を所定量減圧して直接主熱交換部７の冷媒通路７ａの入口に流入させるものである。
冬季の低負荷条件時には、凝縮器３での冷媒圧力と蒸発器６での冷媒圧力との差が小となり、絞り通路９の抵抗による圧力差が全体の圧力差の大半を占めることとなって、冷媒流量が小となり、かつ車室内空気を循環させる内気循環モードでは、小流量の冷媒が比較的高温の内気から吸熱して、主熱交換部７の出口冷媒温度が入口冷媒温度より高くなってしまうことがある。その結果、副熱交換部８で、主熱交換部７の出口冷媒により入口側冷媒を加熱するという不具合が生じる。
【００１８】
そこで、このような低負荷条件下では、前記定圧弁１０を開弁して、上記不具合の発生を防止するようにしてある。
前記主及び副熱交換部７、８及び絞り通路９は金属薄板の積層構造により形成されており、その具体的構造は基本的には特開平５−１９６３２１号公報と同じでよいので、以下積層構造の概略を図２、３により説明すると、主熱交換部７では、金属薄板７ｂ、具体的にはアルミニュウム心材の両面にろう材をクラッドした両面クラッド材を所定形状に成形して、これを２枚１組として多数組積層した上で、ろう付けにより接合することにより多数の冷媒通路７ａを並列に形成するものである。
【００１９】
この多数の冷媒通路７ａはそれぞれ図２、３の上方でＵターンするＵ形状のものであり、この各Ｕ形状の冷媒通路７ａの入口部及び出口部はそれぞれ通路下方部に形成された入口側タンク部７ｃ、出口側タンク部７ｄの開口部にて相互にコア奥行き方向で連通するようになっている。
また、主熱交換部７では、隣接する冷媒通路７ａの外面側相互の間隙にコルゲートフィン（フィン手段）１１を接合して空気側の伝熱面積の増大を図るようになっている。
【００２０】
同様に、副熱交換部８においても、金属薄板８ｃ、具体的にはアルミニュウム心材の両面にろう材をクラッドした両面クラッド材を所定形状に成形して、これを多数枚積層してろう付けにより接合することにより、この多数枚の積層構造の金属薄板８ｃの間に、前記入口側冷媒通路８ａと、出口側冷媒通路８ｂを交互に形成するようになっている。
【００２１】
ここで、副熱交換部８の端板１２には配管コネクタ部材１３が接合されるようになっており、この配管コネクタ部材１３には、膨張弁５で減圧された気液２相冷媒が流入する入口管１３ａと、蒸発器６から圧縮機１側へ吸入されるガス冷媒が流出する出口管１３ｂと、絞り通路９の下流側を定圧弁１０の下流側に接続する接続管１３ｃとが配設されている。
【００２２】
そして、この入口管１３ａからの冷媒は、金属薄板８ｃの上部に形成された、入口側冷媒通路８ａの入口側タンク部８ｄに流入するようになっており、この入口側タンク部８ｄはそれ自身の開口部にてコア奥行き方向に連通している。
一方、金属薄板８ｃの下部に入口側冷媒通路８ａの出口側タンク部８ｅが形成されており、この出口側タンク部８ｅもそれ自身の開口部にてコア奥行き方向に連通している。そして、上部の入口側タンク部８ｄから下部の出口側タンク部８ｅに向かって、入口側冷媒通路８ａが蛇行状に形成されている。
【００２３】
また、前記した絞り通路９は、主熱交換部７のうち最も副熱交換部８寄りの金属薄板７ｂ′と、主、副両熱交換部７、８の中間に介在された肉厚の中間プレート１４との間に形成されるようになっている。
副熱交換部８の入口側冷媒通路８ａの出口側タンク部８ｅから流出した冷媒は中間プレート１４に形成された通路穴（図示せず）を通り、次に絞り通路９の入口部９ａに流入する。そして、この絞り通路９を通過した後、絞り通路９の出口部９ｂから冷媒は中間プレート１４に形成された別の通路穴１４ｂ（図７参照）を通り、再度副熱交換部８側へ流入し、その中継タンク部８ｉを通過して中間プレート１４に形成されたさらに別の通路穴、すなわち後述の冷媒入口穴１６を通り、さらに別体ノズル２１を通り、主熱交換部７の入口側タンク部７ｃに流入する。
【００２４】
そして、ここから冷媒は主熱交換部７の各冷媒通路７ａをＵターン状に流れ、その後出口側タンク部７ｄに集合するようになっている。
この出口側タンク部７ｄに集合した冷媒は、中間プレート１４に形成された別の通路穴１４ａ（図８（ｂ）参照）を通り、副熱交換部８の金属薄板８ｃの下部に形成された、出口側冷媒通路８ｂの入口側タンク部８ｆに流入するようになっており、この入口側タンク部８ｆはそれ自身の開口部にてコア奥行き方向に連通している。一方、金属薄板８ｃの上部に出口側冷媒通路８ｂの出口側タンク部８ｇが形成されており、この出口側タンク部８ｇもそれ自身の開口部にてコア奥行き方向に連通している。そして、下部の入口側タンク部８ｆから上部の出口側タンク部８ｇに向かって、出口側冷媒通路８ｂが略直線状に形成されている。
【００２５】
副熱交換部８において、入口側冷媒通路８ａと出口側冷媒通路８ｂは多数枚積層された金属薄板８ｃの表裏両側に交互に形成されている。出口側冷媒通路８ｂの出口側タンク部８ｇから冷媒は配管コネクタ部材１３の出口管１３ｂへ流出する。１５は主熱交換部７の端板である。
次に、図４により本発明の要部をなす副熱交換部８の内部洩れ（入口側冷媒通路８ａと出口側冷媒通路８ｂとの区画接合部８ｈにろう付け不良等により隙間が生じて、冷媒が洩れる状態をいう）を検査するための構成を説明する。前記冷媒入口穴１６は前記中間プレート１４に設けられた、断面円弧状の円形打ち出し部（円形ノズル形状）を有する形状であって、図７に示すように主熱交換部７の入口側タンク部７ｃにノズル２１を介して連通するものである。
【００２６】
このノズル２１は、中間プレート１４とは別体で独立に形成されたもので、ろう材をクラッドしてないアルミニュウムベア材（Ａ３００３）で切削加工等により所定のノズル形状に形成されている。また、ノズル２１は、その先端部が主熱交換部７の冷媒通路７ａの入口側タンク部７ｃ内に挿入されるように配置されている。
【００２７】
ノズル２１の形状としては、図８に示す例では円錐状の穴部２１ａの頂部に横長の楕円形状からなる絞り穴２１ｂを設けている。この絞り穴２１ｂの横長の楕円形状の方向は、主熱交換部７の冷媒通路７ａへの冷媒分配性を改善するために冷媒入口穴１６および入口側タンク部７ｃに対して所定の方向に規定する必要がある。そのために、図８の例では、ノズル２１の周方向の位置決め用手段として、ノズル２１の外周部に溝部２１ｃを形成するとともに、中間プレート１４には入口冷媒穴１６の外周側にピン１６ａを形成して、溝部２１ｃにピン１６ａを嵌合することによりノズル２１の周方向の位置決めを行うようにしてある。
【００２８】
なお、溝部２１ｃは、ノズル２１の左右対称位置に２箇所設けて、ノズル２１の組付方向が左右逆転しても、同一のノズル２１を使用して対応できるようにしてある。
一方、副熱交換部８の端板１２においては、上記冷媒入口穴１６に対向する部位に穴１２ａが開けられており、この端板１２の穴１２ａに検査治具１７の取付座１８が一体に接合されている。この取付座１８は雌ねじ１８ａを有し、この雌ねじ１８ａにより、上記冷媒入口穴１６を閉塞可能な検査治具１７を挿入できる大きさを持った治具挿入穴１９を設定している。
【００２９】
上記検査治具１７は、雄ねじ１７ａを外周部に形成した本体１７ｂを有し、この本体１７ｂには前記冷媒入口穴１６を閉塞するように円錐状に形成された弁体１７ｃと、この弁体１７ｃに一体に結合された軸部１７ｄが軸方向に移動可能に保持されている。
１７ｅは弁体１７ｃを外方側へ押圧するスプリング、１７ｆ、１７ｇはシール用Ｏリング（シール部材）で、取付座１８に検査治具１７を装着したときに取付座１８の治具挿入穴１９を検査治具１７により密封するためのものである。Ｏリング１７ｇは本体１７ｂの鍔状部１７ｈの端面に配置されており、また他のＯリング１７ｆは本体１７ｂの中心穴１７ｉに配置されている。
【００３０】
なお、Ｏリング１７ｇを本体１７ｂの鍔状部１７ｈの端面に配置せずに、取付座１８側に配置してもよい。
また、検査治具１７としては、図４、５に示すスプリング１７ｅにより弁体１７ｃを冷媒入口穴１６に押圧する形式のものの他に、図９に示すように弁体１７ｃを軸部１７ｄを介して本体１７ｂに一体に連結し、本体１７ｂの雄ねじ１７ａを取付座１８の雌ねじ１８ａにねじ込むことにより、弁体１７ｃを冷媒入口穴１６の内周面に押し当てて、冷媒入口穴１６を閉塞する形式のものであってもよい。
【００３１】
図６において、２０は治具挿入穴１９を密封するための密封部材をなす蓋体で、雄ねじ２０ａを有し、この雄ねじ２０ａにより蓋体２０は取付座１８の雌ねじ１８ａに脱着可能に取付けられる。また、蓋体２０は鍔状部２０ｂを有し、この鍔状部２０ｂの上端面にシール用Ｏリング（シール部材）２０ｃを配置している。なお、このＯリング２０ｃを蓋体２０の端面に配置せずに、取付座１８側に配置してもよい。
【００３２】
次に、上記構成において本実施例の冷媒蒸発器の製造方法及び冷媒洩れの検査方法について説明する。
本実施例では、蒸発器６をアルミニュウムの一体ろう付けで製造するようにしてあるので、冷間鍛造、切削加工等の必要な厚肉部品である配管コネクタ部材１３及び取付座１８、ノズル２１、さらにはろう材の不要なコルゲートフィン１１を除く他の薄板形状の部品は、すべてろう材（Ａ４１０４）を心材（Ａ３００３）の両面にクラッドしたアルミニュウム両面クラッド材から成形されている。
【００３３】
厚肉部品の配管コネクタ部材１３、取付座１８、およびノズル２１と、コルゲートフィン１１はろう材をクラッドしてないアルミニュウムベア材（Ａ３００３）で成形している。
以下製造方法を工程順に説明する。
１．主熱交換部７及び副熱交換部８のそれぞれ個別の組付工程
主熱交換部７においては、まず、入口タンク部７ｃ、出口タンク部７ｄのバーリング形状部７ｅ（図７、９参照）をかしめて口拡することによりコルゲートフィン１１を挟む２つの金属薄板７ｂ、７ｂ（７ｂ′）を一体化して、これらの三者１１、７ｂ、７ｂ（７ｂ′）を１ユニットしておく。しかるのち、端板１５と、前記１ユニット化した金属薄板７ｂ、７ｂ、絞り通路９を形成する金属薄板７ｂ′と、コルゲートフィン１１と、を図２、３に示すごとき形態に積層して、主熱交換部７の組付を終える。
【００３４】
副熱交換部８においては、前述の冷媒入口穴１６を予め加工した中間プレート１４、ノズル２１、金属薄板８ｃ、及び端板１２を図２、３に示す形態に積層するとともに、治具挿入穴１９を設定する雌ねじ１８ａを加工した取付座１８及び配管コネクタ部材１３を端板１２に組付けて、副熱交換部８の組付を終える。
２．蒸発器６全体の組付工程
上記のように、それぞれ個別に組付けられた主熱交換部７と副熱交換部８とを、主熱交換部７が下方、その上方に副熱交換部８が位置するように、この両者７、８を積層して、この両者７、８の積層組付体を縦方向の組付治具により保持して、蒸発器６全体の積層状態を維持する。
３．蒸発器６全体の一体ろう付け工程
縦方向の組付治具により上記両熱交換部７、８の積層状態を維持しながら、この組付体を真空炉中に搬入して、アルミニュウムクラッド材のろう材融点以上に加熱して、組付体各部の接合部分をろう付けにより一体に接合し、蒸発器６全体を一体構造にする。
４．冷媒の外部洩れ検査工程
蒸発器６の外部への開口部は、図２、３、４に示す配管コネクタ部材１３の入口管１３ａ、出口管１３ｂ、接続管１３ｃ及び取付座１８の治具挿入穴１９の４箇所あるので、これらの開口部のうち１つを残して、他の３つの開口部を閉塞する。例えば、入口管１３ａのみ開口しておき、他の開口部はすべて適宜の盲蓋で閉塞しておく。但し、治具挿入穴１９は蓋体２０にて図６に示すように閉塞する。
【００３５】
次に、蒸発器６を密閉室内に搬入し、入口管１３ａに洩れ検査用流体（例えばヘリウムガス）の供給装置を接続して、この検査用流体を所定圧力に加圧して入口管１３ａから蒸発器６の主、副両熱交換部７、８の冷媒通路７ａ、８ａ、８ｂ内に供給し、蒸発器６外への流体洩れ（密閉室内への流体洩れ）の有無を検査する。
５．冷媒の内部洩れ検査工程
副熱交換部８においてろう付け不良等により入口側冷媒通路８ａと出口側冷媒通路８ｂとが直接連通する状態が内部洩れ（図１の矢印Ｘはこの内部洩れを模式的に示す）であり、この内部洩れによる連通状態と、入口側冷媒通路８ａと出口側冷媒通路８ｂとが主熱交換部７の冷媒通路７ａを介して連通している正規の連通状態は、蒸発器６の本来の構成のままでは区別することができない。
【００３６】
そこで、本例では、主熱交換部７の冷媒通路７ａの入口部を閉鎖（図１のＹ部はその閉鎖部を示す）することにより、冷媒の内部洩れの検査を可能としている。すなわち、冷媒の外部洩れ検査工程で装着した蓋体２０を取付座１８から取り外して、その代わりに検査治具１７の先端の弁体１７ｃを取付座１８の治具挿入穴１９から副熱交換部８内に挿入し、検査治具１７の雄ねじ１７ａを取付座１８の雌ねじ１８ａにねじ込む。
【００３７】
図５はこのねじ込みが終了した状態であり、この状態では、鍔状部１７ｈのＯリング１７ｇが取付座１８の端面に圧着して、この端面部分のシールを行う。また、中心穴１７ｉ部分のシールはＯリング１７ｆによって行われる。これと同時に、弁体１７ｃが冷媒入口穴１６の内周面に圧着してこの冷媒入口穴１６を閉鎖する。この閉鎖部分は図１の閉鎖部Ｙに対応する。
【００３８】
そして、接続管１３ｃは適宜の盲蓋で閉塞し、出口管１３ｂは開口したままにしておく。
しかるのち、蒸発器６を密閉室内に搬入し、入口管１３ａに洩れ検査用流体（例えばヘリウムガス）の供給装置を接続して、この検査用流体を所定圧力に加圧して入口管１３ａから蒸発器６の副熱交換部８の入口側冷媒通路８ａ内に供給し、副熱交換部８の入口側冷媒通路８ａから出口側冷媒通路８ｂへの流体洩れ（出口管１３ｂを通して密閉室内への流体洩れ）の有無を検査する。
【００３９】
つまり、図１の矢印Ｘのような内部洩れがあるときは、出口管１３ｂを通して密閉室内へ流体が洩れてくるので、内部洩れの発生を検知できる。
ここで、内部洩れの検査は、本例のように外部洩れを実施した後に行うことが重要である。なぜならば、内部洩れの検査は、本例とは逆に外部洩れの実施前に行うと、内部洩れ検査時に密閉室内に洩れ出た流体が、内部洩れによるものか、外部洩れによるものか判別できないからである。
【００４０】
６．蓋体装着工程
外部洩れ検査及び内部洩れ検査により、洩れなしと判定された良品については、検査治具１７を取付座１８から取り外して、その代わりに蓋体２０を図６に示すように取付座１８にねじ込みで装着し、Ｏリング２０ｃが取付座１８の端面に弾性的に圧着することにより、この端面部分をシールして、取付座１８のねじ部分から外部へ冷媒が洩れることを確実に防ぐ。
【００４１】
以上により蒸発器６の骨格構造の製造を終了でき、この後は表面処理等の仕上げを行うことにより、蒸発器６の製造を完了できる。
なお、上述の例では、密封部材である蓋体２０をねじにより脱着可能に取付座１８に装着しているので、蒸発器６使用後でも、蓋体２０を取り外して、検査治具１７により冷媒入口穴１６を閉鎖することにより、何回も内部洩れの検査を実施できるが、内部洩れの検査を製造工程時に行うだけでよい場合は蓋体２０をねじ込み等の脱着可能な手段で取付座１８に装着せず、かしめ、ろう付け等の手段で蓋体２０を取付座１８側に一体に固着するようにしてもよい。
【００４２】
また、上述の例では、主熱交換部７の冷媒通路７ａの入口部（冷媒入口穴１６）を検査治具１７で閉鎖して、入口管１３ａから検査用流体を加圧して供給するようにしたが、主熱交換部７の冷媒通路７ａの出口部（冷媒入口穴１６の代わりに冷媒出口穴を中間プレート１２に設置する）を検査治具１７で閉鎖して、出口管１３ｂから検査用流体を加圧して供給するようにして、内部洩れの検査を行うことも可能である。
【００４３】
ところで、上述した副熱交換部８における内部洩れの検査を確実に行うためには、中間プレート１４の冷媒入口穴１６の内周面に検査治具１７の先端の弁体１７ｃを密着させて、冷媒入口穴１６を確実に閉鎖する必要がある。そのため、冷媒入口穴１６は検査治具１７の先端の弁体１７ｃとのシール性を確保し易い円形状とする必要が生じ、その形状の選択の自由度がない。
【００４４】
そこで、本例では、冷媒入口穴１６部分とは別体で形成したノズル２１を冷媒入口穴１６の出口側に設置して、主熱交換部７における各冷媒通路７ａへの冷媒分配性の改善（均一な冷媒分配）を図っている。
すなわち、主熱交換部７における各冷媒通路７ａへの冷媒分配性の改善を図るためには、ノズル２１による入口タンク７ｃへの冷媒噴出形態を主熱交換部７のコアサイズ（図２の寸法Ａ、Ｂ）の変更に対応して最適形態に設定する必要があるが、本例では、冷媒入口穴１６の出口側に別体で独立に形成したノズル２１を設置しているので、このノズル２１の交換により前記最適形態設定への対応を容易に行うことができる。
【００４５】
ノズル２１の形状としては、図８に示す例では円錐状の穴部２１ａの頂部に横長の楕円形状からなる絞り穴２１ｂを設けており、そしてこの絞り穴２１ｂの横長の方向は、前述した通り、溝部２１ｃとピン１６ａとの嵌合により所定方向（図８の例では水平方向）に規定している。
また、絞り穴２１ｂの形状は、上記横長の楕円形状の他に、長穴形状、長方形、三角形等の形状を必要に応じて採用してもよい。
【図面の簡単な説明】
【図１】本発明蒸発器を含む冷凍サイクル図である。
【図２】本発明蒸発器の一実施例を示す斜視図である。
【図３】図２の蒸発器の分解斜視図である。
【図４】図２、３の蒸発器において、検査治具挿入前の状態を示す要部断面図である。
【図５】図２、３の蒸発器において、検査治具挿入後の状態を示す要部断面図である。
【図６】図２、３の蒸発器において、検査治具の代わりに蓋体を装着した状態を示す要部断面図である。
【図７】図２、３の蒸発器において、検査治具挿入前の状態を示す要部断面図である。
【図８】（ａ）は図７に示すノズルの正面図、（ｂ）はその断面図、（ｃ）はノズルの組付位置関係を示す分解斜視図である。
【図９】検査治具の他の例を示す図で、検査治具挿入後の状態を示す要部断面図である。
【符号の説明】
６…蒸発器、７…主熱交換部、７ａ…冷媒通路、７ｂ…金属薄板、
８…副熱交換部、８ａ…入口側冷媒通路、８ｂ…出口側冷媒通路、
８ｃ…金属薄板、１４…中間プレート、１６…冷媒入口穴（入口部）、
１７…検査治具、１９…治具挿入穴、２０…蓋体（密封部材）、
２１…ノズル。[0001]
[Industrial application fields]
The present invention relates to a laminated refrigerant evaporator in which a refrigerant passage is formed by a laminated structure of thin metal plates, and more particularly, a laminated refrigerant evaporator having a sub-heat exchanging portion that exchanges heat between internal refrigerants flowing in the refrigerant passage. About.
[0002]
[Prior art]
In Japanese Patent Application Laid-Open No. 5-196321, the applicant of the present application has proposed a stacked evaporator having a sub heat exchange section that exchanges heat between internal refrigerants flowing in the refrigerant passage.
In addition to the main heat exchanging part that performs heat exchange between the normal refrigerant and air, the above-mentioned publication describes that the refrigerant on the evaporator inlet side and the refrigerant on the evaporator outlet side exchange heat, and the main heat exchanging part An auxiliary heat exchange unit (refrigerant-refrigerant heat exchange unit) is provided to reduce the dryness of the refrigerant flowing into the inlet tank.
[0003]
By the action of this sub heat exchange part, the dryness of the refrigerant flowing into the inlet tank of the main heat exchange part is greatly reduced, so that the refrigerant in the inlet tank is in a state close to a liquid single phase. When distributing the refrigerant to a large number of tubes, the liquid refrigerant can be uniformly distributed to each tube. In addition, the inner surface of each tube is covered with the liquid refrigerant, the heat transfer coefficient on the inner surface of the tube is improved, and these can be combined to improve the cooling performance of the evaporator.
[0004]
[Problems to be solved by the invention]
By the way, according to the experimental study by the present inventors, in the above-mentioned publication, there is a specific problem of refrigerant internal leakage due to having a secondary heat exchange part (refrigerant-refrigerant heat exchange part) in the production. I found it to happen. That is, when brazing failure occurs in the auxiliary heat exchange part (refrigerant-refrigerant heat exchange part) which is the heart of performance improvement, the state where the inlet side refrigerant and the outlet side refrigerant of the evaporator are directly mixed, That is, refrigerant leakage (hereinafter referred to as internal leakage) may occur between the refrigerant passages of the auxiliary heat exchange unit. Once this internal leakage occurs, not only does the cooling performance of the evaporator deteriorate, but the air-conditioning refrigeration cycle using this evaporator may become uncontrollable.
[0005]
By the way, since the inlet side and the outlet side of the evaporator are originally communicated with each other through the refrigerant passage of the main heat exchange part, the occurrence of the internal leakage and the regular communication via the refrigerant passage of the main heat exchange part are performed. Since it cannot be distinguished from the state, it has not been possible to confirm the presence of the internal leakage.
The present invention has been made in view of the above points, and in a stacked heat exchanger having a sub heat exchange section that exchanges heat between internal refrigerants flowing in a refrigerant passage, it is possible to accurately detect the presence or absence of internal leakage. The purpose is to do.
[0006]
Another object of the present invention is to simplify the refrigerant distribution to the multiple tubes of the main heat exchanging part even when the core size of the evaporator is changed (change of the number of tube stacking stages, change of the length of the core part). An object of the present invention is to provide a refrigerant evaporator that can be easily adapted by changing the configuration.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following technical means.
In invention of Claim 1, the main heat exchange part (7) which heat-exchanges the refrigerant | coolant which flows through the inside of a refrigerant path (7a), and the to-be-cooled fluid which flows the exterior of the said refrigerant path (7a),
A sub-flow for exchanging heat between the refrigerant flowing into the inlet side of the refrigerant passage (7a) of the main heat exchange section (7) and the refrigerant flowing out from the outlet side of the refrigerant passage (7a) of the main heat exchange section (7). A heat exchange part (8),
The refrigerant passages (7a) of the main and sub heat exchange sections (7, 8) are formed by a laminated structure of thin metal plates (7b, 8c),
In the sub heat exchange section (8), a refrigerant inlet hole (16) and a refrigerant inlet hole (16) are formed in a portion of the main heat exchange section (7) facing the inlet section (7c) of the refrigerant passage (7a). ) Is provided with a jig insertion hole (19) for inserting an inspection jig (17) capable of closing.
The jig insertion hole (19) is equipped with a sealing member (20) for sealing the hole,
Furthermore, the refrigerant | coolant evaporator by which the nozzle (21) formed separately from the said refrigerant | coolant inlet hole part is arrange | positioned at the refrigerant | coolant outlet side of the said refrigerant | coolant inlet hole (16) is characterized.
[0008]
According to a second aspect of the present invention, in the refrigerant evaporator according to the first aspect, the refrigerant inlet hole (16) is located at an end of the auxiliary heat exchange part (8) on the main heat exchange part (7) side. Provided in the arranged intermediate plate (14),
The jig insertion hole (19) is provided in an end plate (12) disposed at an end of the auxiliary heat exchange part (8) opposite to the main heat exchange part (7). It is characterized by that.
[0009]
According to a third aspect of the present invention, in the refrigerant evaporator according to the first or second aspect, the tip of the nozzle (21) is an inlet portion (7a) of the refrigerant passage (7a) of the main heat exchange portion (7). 7c) is arranged so as to be inserted into the inside.
According to a fourth aspect of the present invention, in the refrigerant evaporator according to any one of the first to third aspects, the nozzle (21) has a non-circular throttle hole (21b),
The nozzle (21) is positioned and fixed with respect to the refrigerant inlet hole (16) so that the direction of the non-circular throttle hole (21b) is in a predetermined direction.
[0010]
In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of the Example description described later.
[0011]
[Effects of the invention]
According to invention of Claims 1-4, since it has the said technical means, the communication state of the refrigerant path of a main heat exchange part and the refrigerant path of a sub heat exchange part is interrupted | blocked by an inspection jig. Thus, it is possible to provide a stacked type refrigerant evaporator that can surely carry out an inspection of internal leakage between the refrigerant passages of the auxiliary heat exchange section.
[0012]
Moreover, since the nozzle formed separately from the refrigerant inlet hole portion is arranged on the refrigerant outlet side of the refrigerant inlet hole, the shape of the refrigerant outlet hole may be a circular shape that is easily closed by an inspection jig. The non-circular shape that optimizes the refrigerant distribution property to the large number of refrigerant passages of the main heat exchange section can be set freely with a separate nozzle.
Therefore, in the present invention, even when the core size of the evaporator is changed, the optimum refrigerant distribution can be ensured by a simple configuration change such as change of a separate nozzle.
[0013]
【Example】
The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows a refrigeration cycle of an automobile air conditioner to which a refrigerant evaporator according to the present invention is applied. Reference numeral 1 denotes a compressor, which is driven by an automobile engine (drive source, not shown) via an electromagnetic clutch 2. Is. Reference numeral 3 denotes a condenser, which cools and condenses the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 by exchanging heat with blown air from a cooling fan (not shown).
[0014]
4 is a liquid receiver that stores the liquid refrigerant condensed in the condenser 3 and leads only the liquid refrigerant to the downstream side of the cycle, 5 is a temperature-actuated expansion valve that constitutes a pressure reducing means for the refrigerant, and 5a is a temperature sensing cylinder. is there. Reference numeral 6 denotes a stacked refrigerant evaporator according to the present invention.
The evaporator 6 includes a main heat exchanging unit 7 for exchanging heat between the refrigerant flowing in the refrigerant passage 7a and the air-conditioning blown air (cooled fluid) flowing outside the refrigerant passage 7a.
A sub heat exchanging portion 8 for exchanging heat between the refrigerant flowing into the inlet side of the refrigerant passage 7a of the main heat exchanging portion 7 and the refrigerant flowing out from the outlet side of the refrigerant passage 7a of the main heat exchanging portion 7; ing.
[0015]
Here, in the auxiliary heat exchange unit 8, 8 a denotes an inlet side refrigerant passage through which refrigerant flows into the inlet side of the refrigerant passage 7 a of the main heat exchange unit 7, and 8 b denotes the refrigerant passage 7 a of the main heat exchange unit 7. 2 shows an outlet side refrigerant passage through which refrigerant flowing out from the outlet side of the refrigerant flows. Accordingly, the auxiliary heat exchange unit 8 constitutes a refrigerant-refrigerant heat exchange unit. On the other hand, the main heat exchange unit 7 constitutes a refrigerant evaporation unit (refrigerant-air heat exchange unit) in which the refrigerant absorbs heat from the blown air and evaporates.
[0016]
9 is a narrow passage having a minute cross-sectional area formed in a meandering manner between the inlet side refrigerant passage 8a of the auxiliary heat exchange section 8 and the inlet portion of the refrigerant passage 7a of the main heat exchange section 7, and is generally called a capillary tube. Serves as a decompression means. However, the degree of pressure reduction by the throttle passage 9 is set to be smaller than the degree of pressure reduction of the expansion valve 5, and this throttle passage 9 provides a pressure difference of the refrigerant between the upstream side and the downstream side so that sub heat exchange is performed. By making a difference in temperature between the refrigerant temperature of the inlet side refrigerant passage 8a in the section 8 and the refrigerant temperature of the outlet side refrigerant passage 8b, heat exchange between both the passages 8a and 8b is favorably performed. It is.
[0017]
10 is a constant pressure valve. When the heat load of the refrigeration cycle is significantly reduced as in winter, and the pressure difference before and after that is less than a set value, the valve is opened and the liquid refrigerant from the liquid receiver 4 is depressurized by a predetermined amount directly. It is made to flow into the inlet of the refrigerant passage 7a of the main heat exchange part 7.
Under low load conditions in winter, the difference between the refrigerant pressure in the condenser 3 and the refrigerant pressure in the evaporator 6 is small, and the pressure difference due to the resistance of the throttle passage 9 accounts for most of the total pressure difference. In the inside air circulation mode in which the refrigerant flow rate is small and the passenger compartment air is circulated, the small flow rate refrigerant absorbs heat from the relatively high temperature inside air, and the outlet refrigerant temperature of the main heat exchange unit 7 becomes higher than the inlet refrigerant temperature. May end up. As a result, the sub heat exchange unit 8 has a problem that the inlet side refrigerant is heated by the outlet refrigerant of the main heat exchange unit 7.
[0018]
Therefore, under such a low load condition, the constant pressure valve 10 is opened to prevent the occurrence of the above problem.
The main and auxiliary heat exchanging portions 7 and 8 and the throttle passage 9 are formed by a laminated structure of thin metal plates, and the specific structure may be basically the same as that of JP-A-5-196321. 2 and 3, the main heat exchanging unit 7 forms a metal thin plate 7b, specifically, a double-sided clad material in which a brazing material is clad on both sides of an aluminum core material into a predetermined shape. A large number of refrigerant passages 7a are formed in parallel by laminating a large number of two sheets as one set and joining them by brazing.
[0019]
Each of the plurality of refrigerant passages 7a has a U-shape that makes a U-turn in the upper part of FIGS. 2 and 3, and the inlet portion and the outlet portion of each of the U-shaped refrigerant passages 7a are respectively formed on the inlet side formed in the lower portion of the passage. The tank portion 7c and the outlet side tank portion 7d communicate with each other in the core depth direction.
In the main heat exchanging section 7, corrugated fins (fin means) 11 are joined to the gaps between the outer surfaces of the adjacent refrigerant passages 7a to increase the heat transfer area on the air side.
[0020]
Similarly, in the auxiliary heat exchanging section 8, a thin metal plate 8c, specifically, a double-sided clad material in which a brazing material is clad on both sides of an aluminum core is formed into a predetermined shape, and a large number of these are laminated and brazed. By joining, the inlet side refrigerant passages 8a and the outlet side refrigerant passages 8b are alternately formed between the multiple thin metal plates 8c having a laminated structure.
[0021]
Here, a pipe connector member 13 is joined to the end plate 12 of the auxiliary heat exchange unit 8, and the gas-liquid two-phase refrigerant decompressed by the expansion valve 5 flows into the pipe connector member 13. An inlet pipe 13a, an outlet pipe 13b from which the gas refrigerant sucked from the evaporator 6 to the compressor 1 flows out, and a connection pipe 13c that connects the downstream side of the throttle passage 9 to the downstream side of the constant pressure valve 10 are arranged. It is installed.
[0022]
The refrigerant from the inlet pipe 13a flows into the inlet side tank portion 8d of the inlet side refrigerant passage 8a formed in the upper part of the thin metal plate 8c, and the inlet side tank portion 8d itself The opening communicates in the core depth direction.
On the other hand, an outlet side tank portion 8e of the inlet side refrigerant passage 8a is formed in the lower part of the thin metal plate 8c, and this outlet side tank portion 8e is also communicated in the core depth direction at its own opening. An inlet-side refrigerant passage 8a is formed in a meandering manner from the upper inlet-side tank portion 8d toward the lower outlet-side tank portion 8e.
[0023]
Further, the throttle passage 9 described above is formed between the thin metal plate 7 b ′ closest to the sub heat exchanging portion 8 in the main heat exchanging portion 7 and the intermediate thickness between the main and sub heat exchanging portions 7, 8. It is formed between the plate 14.
The refrigerant flowing out from the outlet side tank portion 8e of the inlet side refrigerant passage 8a of the auxiliary heat exchange portion 8 passes through a passage hole (not shown) formed in the intermediate plate 14, and then flows into the inlet portion 9a of the throttle passage 9. To do. Then, after passing through the throttle passage 9, the refrigerant flows from the outlet portion 9 b of the throttle passage 9 through another passage hole 14 b (see FIG. 7) formed in the intermediate plate 14 and again flows into the auxiliary heat exchange portion 8 side. Then, it passes through the relay tank portion 8i, passes through another passage hole formed in the intermediate plate 14, that is, a refrigerant inlet hole 16 described later, further passes through a separate nozzle 21, and enters the inlet side of the main heat exchanging portion 7. It flows into the tank part 7c.
[0024]
And from here, a refrigerant | coolant flows through each refrigerant path 7a of the main heat exchange part 7 in the shape of a U-turn, and it collects in the outlet side tank part 7d after that.
The refrigerant gathered in the outlet-side tank portion 7d passes through another passage hole 14a (see FIG. 8B) formed in the intermediate plate 14, and is formed in the lower part of the thin metal plate 8c of the auxiliary heat exchange portion 8. The inlet-side tank portion 8f of the outlet-side refrigerant passage 8b flows into the inlet-side tank portion 8f, and the inlet-side tank portion 8f communicates in the core depth direction at its own opening. On the other hand, an outlet side tank portion 8g of the outlet side refrigerant passage 8b is formed on the upper part of the thin metal plate 8c, and this outlet side tank portion 8g is also communicated in the core depth direction at its own opening. An outlet side refrigerant passage 8b is formed in a substantially linear shape from the lower inlet side tank portion 8f toward the upper outlet side tank portion 8g.
[0025]
In the auxiliary heat exchanging section 8, the inlet side refrigerant passages 8a and the outlet side refrigerant passages 8b are alternately formed on both front and back sides of the laminated metal thin plates 8c. The refrigerant flows out from the outlet side tank portion 8g of the outlet side refrigerant passage 8b to the outlet pipe 13b of the pipe connector member 13. Reference numeral 15 denotes an end plate of the main heat exchange unit 7.
Next, the internal leakage of the auxiliary heat exchanging portion 8 constituting the main part of the present invention according to FIG. 4 (a gap is generated due to brazing failure etc. in the partition joint portion 8h between the inlet side refrigerant passage 8a and the outlet side refrigerant passage 8b, A configuration for inspecting a state in which the refrigerant leaks) will be described. The refrigerant inlet hole 16 has a circular punching portion (circular nozzle shape) provided in the intermediate plate 14 and having an arc cross section, as shown in FIG. 7 c communicates with the nozzle 21.
[0026]
The nozzle 21 is formed separately from the intermediate plate 14 and is independently formed, and is formed into a predetermined nozzle shape by cutting or the like using an aluminum bare material (A3003) not clad with a brazing material. Further, the nozzle 21 is disposed so that the tip end portion thereof is inserted into the inlet side tank portion 7 c of the refrigerant passage 7 a of the main heat exchange portion 7.
[0027]
As the shape of the nozzle 21, in the example shown in FIG. 8, a constricted hole 21b having a horizontally long elliptical shape is provided at the top of the conical hole 21a. The direction of the oblong shape of the throttle hole 21b is defined in a predetermined direction with respect to the refrigerant inlet hole 16 and the inlet side tank portion 7c in order to improve the refrigerant distribution property to the refrigerant passage 7a of the main heat exchanging portion 7. There is a need to. Therefore, in the example of FIG. 8, as a means for positioning the nozzle 21 in the circumferential direction, a groove portion 21 c is formed on the outer peripheral portion of the nozzle 21, and a pin 16 a is formed on the outer peripheral side of the inlet refrigerant hole 16 in the intermediate plate 14. The nozzle 21 is positioned in the circumferential direction by fitting the pin 16a into the groove 21c.
[0028]
In addition, the groove part 21c is provided in two places in the left-right symmetrical position of the nozzle 21, so that the same nozzle 21 can be used even if the assembly direction of the nozzle 21 is reversed left and right.
On the other hand, in the end plate 12 of the auxiliary heat exchanging portion 8, a hole 12 a is formed in a portion facing the refrigerant inlet hole 16, and the mounting seat 18 of the inspection jig 17 is integrated with the hole 12 a of the end plate 12. It is joined to. The mounting seat 18 has a female screw 18a, and a jig insertion hole 19 having a size capable of inserting the inspection jig 17 capable of closing the refrigerant inlet hole 16 is set by the female screw 18a.
[0029]
The inspection jig 17 has a main body 17b in which an external thread 17a is formed on the outer peripheral portion. The main body 17b has a conical valve body 17c so as to close the refrigerant inlet hole 16, and the valve body. A shaft portion 17d integrally coupled to 17c is held so as to be movable in the axial direction.
17e is a spring that presses the valve body 17c outward, and 17f and 17g are sealing O-rings (seal members). When the inspection jig 17 is mounted on the mounting seat 18, a jig insertion hole 19 in the mounting seat 18 is provided. Is sealed with the inspection jig 17. The O-ring 17g is disposed on the end face of the flange portion 17h of the main body 17b, and the other O-ring 17f is disposed in the center hole 17i of the main body 17b.
[0030]
The O-ring 17g may be disposed on the mounting seat 18 side without being disposed on the end face of the flange portion 17h of the main body 17b.
Further, as the inspection jig 17, in addition to the type in which the valve body 17 c is pressed against the refrigerant inlet hole 16 by the spring 17 e shown in FIGS. 4 and 5, the valve body 17 c is interposed via the shaft portion 17 d as shown in FIG. 9. The main body 17b is integrally connected, and the male screw 17a of the main body 17b is screwed into the female screw 18a of the mounting seat 18, whereby the valve body 17c is pressed against the inner peripheral surface of the refrigerant inlet hole 16 to close the refrigerant inlet hole 16. It may be of a form.
[0031]
In FIG. 6, reference numeral 20 denotes a lid that forms a sealing member for sealing the jig insertion hole 19, and has a male screw 20 a, and the lid 20 is detachably attached to the female screw 18 a of the mounting seat 18 by the male screw 20 a. . Further, the lid 20 has a bowl-shaped part 20b, and a sealing O-ring (seal member) 20c is disposed on the upper end surface of the bowl-shaped part 20b. The O-ring 20c may be disposed on the mounting seat 18 side without being disposed on the end face of the lid body 20.
[0032]
Next, a method for manufacturing the refrigerant evaporator and a method for inspecting refrigerant leakage in this embodiment will be described.
In this embodiment, since the evaporator 6 is manufactured by integrally brazing aluminum, the pipe connector member 13 and the mounting seat 18, the nozzle 21, which are necessary thick parts such as cold forging and cutting, Further, all of the thin plate-like parts other than the corrugated fins 11 that do not require the brazing material are formed from an aluminum double-sided clad material in which the brazing material (A4104) is clad on both sides of the core material (A3003).
[0033]
The thick-walled pipe connector member 13, the mounting seat 18, the nozzle 21, and the corrugated fin 11 are formed of an aluminum bare material (A3003) in which a brazing material is not clad.
Hereinafter, the production method will be described in the order of steps.
1. In the individual assembly process main heat exchange section 7 for each of the main heat exchange section 7 and the sub heat exchange section 8, first, the burring shape section 7e (see FIGS. 7 and 9) of the inlet tank section 7c and the outlet tank section 7d is used. The two metal thin plates 7b and 7b (7b ') sandwiching the corrugated fin 11 are integrated by caulking and the three members 11, 7b and 7b (7b') are united. After that, the end plate 15, the thin metal plates 7b and 7b made into one unit, the thin metal plate 7b 'forming the throttle passage 9, and the corrugated fin 11 are laminated in the form shown in FIGS. The assembly of the main heat exchange part 7 is finished.
[0034]
In the auxiliary heat exchanging portion 8, the intermediate plate 14, the nozzle 21, the metal thin plate 8c, and the end plate 12 in which the refrigerant inlet hole 16 is previously processed are stacked in the form shown in FIGS. The mounting seat 18 and the pipe connector member 13 in which the female screw 18a for setting 19 is processed are assembled to the end plate 12, and the assembly of the auxiliary heat exchange unit 8 is completed.
2. Assembling process of the entire evaporator 6 As described above, the main heat exchanging section 7 and the sub heat exchanging section 8 that are individually assembled are connected to the main heat exchanging section 7 below and above the sub heat exchanging section 8. The two layers 7 and 8 are stacked so that is positioned, and the stacked assembly of both the layers 7 and 8 is held by the vertical assembly jig to maintain the stacked state of the entire evaporator 6.
3. An integral brazing process for the entire evaporator 6. While maintaining the laminated state of the heat exchangers 7 and 8 by means of an assembling jig in the vertical direction, the assembled body is carried into a vacuum furnace and an aluminum clad material is formed. It heats more than melting | fusing point of brazing material, the junction part of each part of an assembly body is integrally joined by brazing, and the whole evaporator 6 is made into an integral structure.
4). Refrigerant External Leakage Inspection Process The opening to the outside of the evaporator 6 has an inlet pipe 13a, an outlet pipe 13b, a connecting pipe 13c and a jig insertion hole in the mounting seat 18 shown in FIGS. Since there are 19 four locations, one of these openings is left and the other three openings are closed. For example, only the inlet pipe 13a is opened, and all other openings are closed with an appropriate blind cover. However, the jig insertion hole 19 is closed by the lid 20 as shown in FIG.
[0035]
Next, the evaporator 6 is carried into the sealed chamber, a leakage inspection fluid (for example, helium gas) supply device is connected to the inlet pipe 13a, and the inspection fluid is pressurized to a predetermined pressure and evaporated from the inlet pipe 13a. The refrigerant is supplied into the refrigerant passages 7a, 8a and 8b of the main and sub heat exchange sections 7 and 8 of the evaporator 6, and the presence or absence of fluid leakage outside the evaporator 6 (fluid leakage into the sealed chamber) is inspected.
5. Internal refrigerant leakage inspection process In the secondary heat exchange section 8, the state where the inlet side refrigerant passage 8a and the outlet side refrigerant passage 8b are in direct communication due to poor brazing or the like is an internal leakage (the arrow X in FIG. 1 schematically shows this internal leakage). And the normal communication state in which the inlet-side refrigerant passage 8a and the outlet-side refrigerant passage 8b communicate with each other via the refrigerant passage 7a of the main heat exchanging portion 7 is an evaporation state. The original configuration of the vessel 6 cannot be distinguished.
[0036]
Therefore, in this example, the internal leakage of the refrigerant can be inspected by closing the inlet portion of the refrigerant passage 7a of the main heat exchanging portion 7 (the Y portion in FIG. 1 indicates the closed portion). That is, the lid 20 mounted in the refrigerant external leakage inspection process is removed from the mounting seat 18, and instead, the valve body 17 c at the tip of the inspection jig 17 is inserted from the jig insertion hole 19 of the mounting seat 18 into the auxiliary heat exchange section. 8, the male screw 17 a of the inspection jig 17 is screwed into the female screw 18 a of the mounting seat 18.
[0037]
FIG. 5 shows a state in which the screwing is completed. In this state, the O-ring 17g of the flange-shaped portion 17h is pressed against the end surface of the mounting seat 18 to seal the end surface portion. The center hole 17i is sealed by an O-ring 17f. At the same time, the valve body 17 c is pressed against the inner peripheral surface of the refrigerant inlet hole 16 to close the refrigerant inlet hole 16. This closed portion corresponds to the closed portion Y in FIG.
[0038]
The connecting pipe 13c is closed with an appropriate blind lid, and the outlet pipe 13b is left open.
After that, the evaporator 6 is carried into the sealed chamber, a leakage inspection fluid (for example, helium gas) supply device is connected to the inlet pipe 13a, and the inspection fluid is pressurized to a predetermined pressure and evaporated from the inlet pipe 13a. The fluid leaks from the inlet side refrigerant passage 8a of the auxiliary heat exchange unit 8 to the outlet side refrigerant passage 8b (fluid into the sealed chamber through the outlet pipe 13b). Check for leaks.
[0039]
That is, when there is an internal leak as indicated by an arrow X in FIG. 1, the fluid leaks into the sealed chamber through the outlet pipe 13b, so that the occurrence of the internal leak can be detected.
Here, it is important that the inspection for the internal leakage is performed after the external leakage is performed as in this example. This is because if the internal leak test is performed prior to the external leak, contrary to this example, it cannot be determined whether the fluid leaking into the sealed chamber during the internal leak test is due to an internal leak or an external leak. Because.
[0040]
6). For the good product determined to be free from leakage by the external leak inspection and internal leak inspection, the inspection jig 17 is removed from the mounting seat 18, and the lid 20 is replaced with a mounting seat as shown in FIG. The O-ring 20c is elastically pressure-bonded to the end face of the mounting seat 18 so as to seal the end face portion, thereby reliably preventing the refrigerant from leaking from the threaded portion of the mounting seat 18 to the outside. .
[0041]
The manufacture of the skeleton structure of the evaporator 6 can be completed as described above, and thereafter the manufacture of the evaporator 6 can be completed by finishing the surface treatment or the like.
In the above-described example, the lid 20 that is a sealing member is attached to the mounting seat 18 so as to be detachable with screws. Therefore, the lid 20 is removed even after the evaporator 6 is used, and the inspection jig 17 allows the refrigerant to be removed. By closing the inlet hole 16, the internal leak can be inspected many times. However, when the internal leak only needs to be inspected during the manufacturing process, the lid 20 can be attached and removed by means such as screwing. The lid 20 may be integrally fixed to the mounting seat 18 side by means such as caulking or brazing.
[0042]
In the above example, the inlet portion (refrigerant inlet hole 16) of the refrigerant passage 7a of the main heat exchanging portion 7 is closed by the inspection jig 17, and the inspection fluid is pressurized and supplied from the inlet pipe 13a. However, the exit part of the refrigerant passage 7a of the main heat exchange part 7 (the refrigerant outlet hole is installed in the intermediate plate 12 instead of the refrigerant inlet hole 16) is closed with the inspection jig 17, and the inspection pipe 17b is used for inspection. It is also possible to check for internal leakage by supplying fluid under pressure.
[0043]
By the way, in order to reliably inspect the internal leakage in the auxiliary heat exchange section 8 described above, the valve body 17c at the tip of the inspection jig 17 is brought into close contact with the inner peripheral surface of the refrigerant inlet hole 16 of the intermediate plate 14, It is necessary to securely close the refrigerant inlet hole 16. Therefore, the refrigerant inlet hole 16 needs to have a circular shape that can easily ensure the sealing property with the valve body 17c at the tip of the inspection jig 17, and there is no degree of freedom in selecting the shape.
[0044]
Therefore, in this example, the nozzle 21 formed separately from the refrigerant inlet hole 16 portion is installed on the outlet side of the refrigerant inlet hole 16 to improve the refrigerant distribution property to the refrigerant passages 7a in the main heat exchange section 7. (Uniform refrigerant distribution).
That is, in order to improve the refrigerant distribution property to each refrigerant passage 7a in the main heat exchanging portion 7, the refrigerant jet form to the inlet tank 7c by the nozzle 21 is changed to the core size of the main heat exchanging portion 7 (dimensions in FIG. 2). Although it is necessary to set the optimum form corresponding to the change of A and B), in this example, the nozzle 21 formed separately and independently is installed on the outlet side of the refrigerant inlet hole 16, so this nozzle By exchanging 21, it is possible to easily cope with the optimum configuration setting.
[0045]
As the shape of the nozzle 21, in the example shown in FIG. 8, a constricted hole portion 21b having a horizontally long elliptical shape is provided at the top of the conical hole portion 21a, and the horizontally elongated direction of the restrictive hole 21b is as described above. The groove portion 21c and the pin 16a are defined in a predetermined direction (horizontal direction in the example of FIG. 8).
Further, as the shape of the throttle hole 21b, in addition to the horizontally long elliptical shape, a shape such as a long hole shape, a rectangle, or a triangle may be adopted as necessary.
[Brief description of the drawings]
FIG. 1 is a refrigeration cycle diagram including an evaporator according to the present invention.
FIG. 2 is a perspective view showing an embodiment of the evaporator of the present invention.
FIG. 3 is an exploded perspective view of the evaporator of FIG.
4 is a cross-sectional view of a main part showing a state before the inspection jig is inserted in the evaporator of FIGS. 2 and 3. FIG.
5 is a cross-sectional view of the main part showing a state after the inspection jig is inserted in the evaporator of FIGS. 2 and 3. FIG.
6 is a cross-sectional view of a main part showing a state where a lid is attached instead of the inspection jig in the evaporator of FIGS.
7 is a cross-sectional view of a main part showing a state before the inspection jig is inserted in the evaporator of FIGS. 2 and 3. FIG.
8A is a front view of the nozzle shown in FIG. 7, FIG. 8B is a sectional view thereof, and FIG. 8C is an exploded perspective view showing a positional relationship of the nozzles.
FIG. 9 is a view showing another example of the inspection jig and is a cross-sectional view of the main part showing a state after the inspection jig is inserted.
[Explanation of symbols]
6 ... Evaporator, 7 ... Main heat exchange part, 7a ... Refrigerant passage, 7b ... Metal thin plate,
8 ... Sub heat exchange part, 8a ... Inlet side refrigerant passage, 8b ... Outlet side refrigerant passage,
8c ... Metal thin plate, 14 ... Intermediate plate, 16 ... Refrigerant inlet hole (inlet part),
17 ... Inspection jig, 19 ... Jig insertion hole, 20 ... Lid (sealing member),
21 ... Nozzle.

Claims

A main heat exchanging section for exchanging heat between the refrigerant flowing in the refrigerant passage and the cooled fluid flowing outside the refrigerant passage;
A sub heat exchange section that exchanges heat between the refrigerant flowing into the inlet side of the refrigerant passage of the main heat exchange section and the refrigerant flowing out from the outlet side of the refrigerant path of the main heat exchange section,
The refrigerant passages of the main and sub heat exchange parts are formed by a laminated structure of metal thin plates,
In the auxiliary heat exchanging part, a refrigerant inlet hole and a jig insertion hole for inserting an inspection jig capable of closing the refrigerant inlet hole are provided in a part facing the inlet part of the refrigerant passage of the main heat exchanging part. Provided,
The jig insertion hole is equipped with a sealing member for sealing the hole,
Furthermore, the nozzle formed separately from the said refrigerant | coolant inlet hole part is arrange | positioned at the refrigerant | coolant outlet side of the said refrigerant | coolant inlet hole, The refrigerant evaporator characterized by the above-mentioned.

The refrigerant inlet hole is provided in an intermediate plate disposed at an end of the auxiliary heat exchange part on the main heat exchange part side,
2. The refrigerant according to claim 1, wherein the jig insertion hole is provided in an end plate disposed at an end of the auxiliary heat exchange portion opposite to the main heat exchange portion. Evaporator.

3. The refrigerant evaporator according to claim 1, wherein the nozzle is disposed such that a tip portion thereof is inserted into an inlet portion of a refrigerant passage of the main heat exchange unit.

The nozzle has a non-circular aperture;
4. The nozzle according to claim 1, wherein the nozzle is positioned and fixed with respect to the refrigerant inlet hole so that the direction of the non-circular throttle hole is in a predetermined direction. The refrigerant evaporator as described.