JP2004281146A

JP2004281146A - Separator for fuel cell, and its manufacturing method

Info

Publication number: JP2004281146A
Application number: JP2003068939A
Authority: JP
Inventors: Tomoji Takahashi; 友次高橋; Yuichi Hori; 裕一堀
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2003-03-13
Filing date: 2003-03-13
Publication date: 2004-10-07
Anticipated expiration: 2023-03-13
Also published as: JP4291020B2

Abstract

PROBLEM TO BE SOLVED: To provide a separator for a fuel cell capable of securing a gas passage, of suitably flattening a top part, and of preventing damage of the top part; and to provide its manufacturing method. SOLUTION: This separator 15 for a fuel cell is so structured that channels for gas passages are formed between protrusion parts 42 by forming the protrusion parts 42 almost linearly extending on a flat separator surface 41, and the channels for the gas passages are formed by bringing the protrusion parts 42 into contact with positive/negative electrode layers. Each protrusion part 42 of the separator 15 comprises: a pair of leg parts 43 erected nearly perpendicularly to the separator surface 41; overhanging parts 44 overhanging toward the outside from the upper ends 43a of the leg parts 43; and abutting parts 45 straddling the upper ends 44a of the overhanging parts 44 so as to be parallel with the separator surface 41. COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、電解質膜の両側にそれぞれ正・負の電極層を積層し、これらを両側から挟持することにより燃料電池のセルモジュールを構成する燃料電池用セパレータ及びそれの製造方法に関する。
【０００２】
【従来の技術】
燃料電池は、電解質膜の両側にそれぞれ正電極層および負電極層を積層し、正・負の電極層にそれぞれセパレータを当接させてセルモジュールを構成し、このセルモジュールを多数個積層したものである。
【０００３】
ここで、正電極層には酸素ガスを接触させる必要がある。このため、正電極層にセパレータを当接することで、正電極層とセパレータとの間に酸素ガスを導くガス流路を形成する。
一方、負電極層には水素ガスを接触させる必要がある。このため、負電極層にセパレータを当接することで、負電極層とセパレータとの間に水素ガスを導くガス流路を形成する。
【０００４】
このセパレータとして、表面に複数の突起部を設けたものが知られている（例えば、特許文献１参照。）。
【０００５】
【特許文献１】
特開２０００−６７８８８公報（第３−４頁、図１−図２）
【０００６】
特許文献１について次図を参照の上、詳しく説明する。
図１６は従来のセパレータを示す平面図である。
セパレータ１００の表面１０１に複数の突起部１０２・・・（・・・は複数を示す）を設け、半球状に突出した頂部１０３・・・を押し潰して平坦にすることで、頂部１０３・・・を正電極層や負電極層の表面に沿うように張り出す。
頂部１０３・・・を平坦に押し潰すことで、正電極層や負電極層の表面に当接（接触）する面積が増す。
よって、正・負の電極層とセパレータ１００との導電性を高めることができる。
【０００７】
図１７（ａ），（ｂ）は従来のセパレータの製造方法を示す説明図である。
（ａ）において、セパレータ１００の表面１０１に複数の突起部１０２・・・を設け、突起部１０２・・・の頂部１０３・・・を半球状に突出させる。
この突起部１０３を突出させる際に、頂部１０３の肉厚ｔ１を、セパレータ１００の基部の板厚ｔ２より薄くなるように形成する。
【０００８】
（ｂ）において、突起部１０２・・・の頂部１０３・・・を平面パンチ１０４で、突起部１０２・・・の突出方向に対して逆方向に矢印の如く押し付ける。
これにより、頂部１０３・・・を平坦に押し潰して、正電極層や負電極層の表面に当接（接触）する面積を増加させる。
ここで、（ａ）で示すように、頂部１０３の肉厚ｔ１を基部の板厚ｔ２より薄くしたので、平面パンチ１０４で押圧することにより、半球状の頂部１０３を平坦に押し広げて膨出部１０５・・・（図１６も参照）を形成する。
【０００９】
頂部１０３を平坦に押し広げて膨出部１０５を形成することで、突起部１０２の外径を大きくすることなく、正・負の電極層の表面に当接（接触）する面積を増加させる。
突起部の外径を大きくする必要がないので、酸素ガスや水素ガスのガス流路を確保することが可能になる。
加えて、正・負の電極層の表面に当接（接触）する面積を増加させることで、導電性を高めることも可能になる。
【００１０】
【発明が解決しようとする課題】
図１８は従来のセパレータの半球状の頂部を平坦に押し広げる例を説明する図である。
突起部１０２の頂部１０３を平面パンチ１０４（図１７（ｂ）参照）で押圧することにより、半球状の頂部１０３を放射状に矢印の如く３６０°の範囲で押し広げ、突起部１０２の外周１０６に沿って膨出部１０５を環状に成形する。
ここで、半球状の頂部１０３を矢印の如く放射状に３６０°の範囲で押し広げるために、頂部１０３の肉厚ｔ１（図１７（ａ）参照）が薄くなりすぎて、頂部１０３が破損する虞がある。
【００１１】
加えて、半球状の頂部１０３を矢印の如く放射状に３６０°の範囲で押し広げるために、頂部１０３に凹凸（すなわち、皺）１０７・・・が発生する虞がある。頂部１０３に凹凸１０７・・・が発生すると、頂部１０３を、正・負の電極層の表面に好適に当接（接触）させることは難しい。
このため、頂部１０３を好適に平坦化する技術の実用化が望まれていた。
【００１２】
そこで、本発明の目的は、酸素ガスや水素ガスのガス流路を確保するとともに、頂部を好適に平坦化して導電性を高め、加えて頂部の破損を防止することができる燃料電池用セパレータ及びそれの製造方法を提供することにある。
【００１３】
【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は、平坦なセパレータ面にほぼ直線状に延びた複数の凸条部を設けることにより凸条部間にガス流路用溝を形成し、凸条部を正電極層又は負電極層に当接させてガス流路用溝をガス流路に形成する燃料電池用セパレータにおいて、前記凸条部は、前記セパレータ面に対してほぼ直角に立ち上げた一対の脚部と、それぞれの脚部の上端から外側に向けて張り出した張出部と、それぞれの張出部の上端に、前記セパレータ面に対して平行になるように掛け渡した当接部とからなり、この当接部を前記正電極層又は負電極層に当接させることを特徴とする。
【００１４】
凸条部をほぼ直線状に延ばし、一対の脚部の上端から外側に向けて張出部を張り出した。これら張出部の上端に当接部を掛け渡し、この当接部を電極層に当接させるように構成した。
当接部の両側部を一対の脚部の外側に向けて幅方向に張り出すことで、一対の脚部の間隔を狭く抑えた状態で、当接部の幅を一対の脚部の幅より大きく広げることが可能になる。
【００１５】
このように、一対の脚部の間隔を狭く抑えることで、凸条部間のガス流路用溝を大きく確保ことができる。さらに、当接部の幅を一対の脚部の幅より大きく広げることで、電極層に当接させる面積を大きく確保することができる。
【００１６】
さらに、凸条部を、ほぼ直線状に延びた突起とすることで、当接部を成形する際に、凸条部の頂部を幅方向にのみ広げるだけでよい。
これにより、従来技術のように、半球状の頂部を放射状に３６０°の範囲で押し広げる必要がない。よって、頂部から当接部を成形する際に、頂部が薄くなりすぎて破損することを防止でき、さらに頂部を平坦に好適に広げることがことができる。
【００１７】
請求項２において、セパレータは、当接部の肉厚を、脚部の肉厚ととほぼ同一にしたことを特徴とする。
【００１８】
当接部の肉厚を、脚部の肉厚ととほぼ同一にすることで、当接部の剛性を確保することで、当接部が破損することを防止する。
【００１９】
請求項３は、正電極層又は負電極層に対向する面にガス流路用溝を備え、正・負の電極層に当接させてガス流路用溝をガス流路とする燃料電池用セパレータの製造方法において、板状素材の面に対してほぼ直交する方向に、ほぼ直線状に延びた複数の凸条部を突出させ、凸条部間に前記ガス流路用溝を成形する工程と、各凸条部の頂部のほぼ中央を、凸条部の突出方向と逆方向に押圧することで、前記頂部のほぼ中央に凹みを成形する工程と、この凹みの両側部を凸条部の突出方向と逆方向に押圧することで、前記両側部をそれぞれ外側に向けて幅方向に張り出すとともに、前記頂部を前記電極層に当接可能となるように平坦に成形する工程と、から燃料電池用セパレータの製造方法を構成する。
【００２０】
ここで、従来技術で説明したように、半球状の頂部を放射状に３６０°の範囲で押し広げようとうすると、頂部の肉厚が薄くなりすぎて破損する虞がある。加えて、半球状の頂部を放射状に３６０°の範囲で押し広げようとうすると、頂部に凹凸（すなわち、皺）が発生する虞があり、平坦に成形することは難しい。
【００２１】
そこで、請求項３において、ほぼ直線状に延びた凸条部を成形した後、凸条部の頂部中央に凹みを成形し、その後凹みの両側部を外側に向けて幅方向にのみ張り出すようにした。
これにより、従来技術のように、頂部を放射状に広げる必要がないので、頂部の肉厚が薄くなりすぎて破損することを防ぐことができ、かつ凹凸（すなわち、皺）が発生することを防ぐことができる。よって、頂部を電極層に当接可能に良好に平坦にすることができる。
【００２２】
また、凸条部のうち、頂部を除いた部位を広げる必要がないので、凸条部間のガス流路用溝の幅を大きく確保することが可能になる。
【００２３】
請求項４は、正電極層又は負電極層に対向する面にガス流路用溝を備え、正・負の電極層に当接させてガス流路用溝をガス流路とする燃料電池用セパレータの製造方法において、板状素材の面に対してほぼ直交する方向に、ほぼ直線状に延びた複数の凸条部を突出させ、凸条部間に前記ガス流路用溝を成形する工程と、各凸条部の頂部のほぼ中央を、凸条部の突出方向と逆方向に押圧することで、前記頂部のほぼ中央に凹みを成形する工程と、この凹みの両側部を凸条部の突出方向と逆方向に押圧することで、前記両側部をそれぞれ外側に向けて幅方向に張り出すとともに、前記頂部をほぼ平坦に成形する工程と、この頂部を凸条部の突出方向と逆方向に押圧することで、前記電極層に当接可能となるように平坦に成形する工程と、から燃料電池用セパレータの製造方法を提供する。
【００２４】
請求項４によれば、請求項３と同様に、ほぼ直線状に延びた凸条部を成形した後、凸条部の頂部中央に凹みを成形し、その後凹みの両側部を外側に向けて幅方向にのみ張り出すようにした。
これにより、従来技術のように、頂部を放射状に広げる必要がないので、頂部の肉厚が薄くなりすぎて破損することを防ぐことができ、かつ凹凸（すなわち、皺）が発生することを防ぐことができる。よって、頂部を電極層に当接可能に良好に平坦にすることができる。
【００２５】
また、凸条部のうち、頂部を除いた部位を広げる必要がないので、凸条部間のガス流路用溝の幅を大きく確保することが可能になる。
【００２６】
加えて、請求項４によれば、頂部を平坦に成形する際に、凹みの両側部を外側に向けてラフに予備成形する工程と、頂部を平坦に成形する工程との２工程に分けた。これにより、頂部を平坦に成形する際に、成形荷重を各工程毎に分けて頂部にかけることができる。
したがって、頂部に成形荷重を集中的にかける必要がないので、成形荷重で凸条部の脚部が座屈変形することを防ぐことができる。
【００２７】
【発明の実施の形態】
本発明の実施の形態を添付図に基づいて以下に説明する。なお、図面は符号の向きに見るものとする。
図１は本発明に係る燃料電池用セパレータ（第１実施の形態）を備えた燃料電池を示す分解斜視図である。
燃料電池１０は、一例として電解質膜１２に固体高分子電解質を使用し、この電解質膜１２に正電極層１３および負電極層１４を積層し、正電極層１３に正極用のセパレータ（燃料電池用セパレータ）１５を当接するとともに、負電極層１４に負極用のセパレータ（燃料電池用セパレータ）１６を当接することによりセルモジュール１１を構成し、このセルモジュール１１を多数個積層した固体高分子型燃料電池である。
【００２８】
正極用のセパレータ１５は、正電極層１３に当接する面１５ａに酸素ガス流路用溝（ガス流路用溝）２１・・・を備え、正電極層１３に重ね合わせることで、酸素ガス流路用溝２１・・・の開口２７・・・（図３も参照）を正電極層１３で塞いで酸素ガス流路（ガス流路）２２（図３参照）を形成した略矩形状の部材である。
この酸素ガス流路２２に、正・負極のセパレータ１５，１６の上端右側の酸素ガス供給孔２３，２４を連通するとともに、正・負極のセパレータ１５，１６の下端左側の酸素ガス排出孔２５，２６を連通する。
【００２９】
負極用のセパレータ１６は、負電極層１４に当接する面１６ａに水素ガス流路用溝（ガス流路用溝）（図示せず）を備え、負電極層１４に重ね合わせることで、水素ガス流路用溝の開口（図示せず）を負電極層１４で塞いで水素ガス流路（ガス流路）（図示せず）を形成した略矩形状の部材である。
この水素ガス流路に、正・負極のセパレータ１５，１６の上端左側の水素ガス供給孔３３，３４を連通するとともに、正・負極のセパレータ１５，１６の下端右側の水素ガス排出孔部３５，３６を連通する。
【００３０】
正・負極のセパレータ１５，１６は、一例としてアルミニウム、アルミ合金、ステンレス鋼などの金属で形成した部材である。
なお、正・負極のセパレータ１５，１６は略同じ構成なので、以下、正極用のセパレータ１５について説明して、負極用のセパレータ１６の説明を省略する。以下、正極用のセパレータ１５を、単に「セパレータ」１５と称して説明する。
【００３１】
図２は本発明に係る燃料電池用セパレータ（第１実施の形態）の要部を示す斜視図である。
セパレータ１５は、正電極層１３に当接する面１５ａ（図１参照）側に、平坦なセパレータ面４１を備え、このセパレータ面４１に、白抜き矢印Ａ−Ａ方向にほぼ直線状に延びた複数本の凸条部４２・・・を設けることにより凸条部４２・・・間に酸素ガス流路用溝２１・・・を形成したものである。
【００３２】
凸条部４２は、セパレータ面４１に所定の間隔Ｓ１をおいて形成した突起である。凸条部４２，４２の間隔Ｓ１は、酸素ガス流路用溝２１の幅と同じである。凸条部４２は、セパレータ面４１から一対の脚部４３，４３を立ち上げ、それぞれの脚部４３，４３から外側に向けて張出部４４，４４を張り出し、それぞれの張出部４４，４４に当接部４５を掛け渡したものである。
ここで、一対の張出部４４，４４および当接部４５で平坦拡張頂部（頂部）４６を構成する。
【００３３】
両側に張出部４４，４４を張り出すことで、当接部４５の幅Ｓ２を、一対の脚部４３，４３間の幅Ｓ３より大きく確保する。
この当接部４５を平坦に形成するとともに、正電極層１３（図１参照）に当接可能に形成することで、正電極層１３に当接する当接面積を大きく確保する。
【００３４】
図３は本発明に係る燃料電池用セパレータ（第１実施の形態）を示す断面図である。
セパレータ１５の当接部４５を正電極層１３（想像線で示す）に当接することで、凸条部４２，４２間に形成した酸素ガス流路用溝２１の開口２７を塞ぎ、酸素ガス流路用溝２１から酸素ガス流路２２を形成する。
【００３５】
凸条部４２は、セパレータ面４１に対してほぼ直角に立ち上げた一対の脚部４３，４３と、それぞれの脚部４３，４３の上端４３ａ，４３ａから外側に向けて幅方向（白抜き矢印Ｂ−Ｂ方向）に張り出した両側の張出部４４，４４と、それぞれの張出部４４，４４の上端４４ａ，４４ａに、セパレータ面４１に対して平行になるように掛け渡した当接部４５とからなる。
【００３６】
両側の張出部４４，４４を備えることで、当接部４５の両側部４５ａ，４５ａを一対の脚部４３，４３の外側に向けて幅方向に張り出す。これにより、一対の脚部４３，４３の幅Ｓ３を狭く抑えたままの状態で、当接部４５の幅Ｓ２を一対の脚部の幅Ｓ３より広げることが可能になる。
【００３７】
一対の脚部４３，４３の幅Ｓ３を狭く抑えることで、酸素ガス流路用溝２１（酸素ガス流路２２）の幅Ｓ１を大きく確保する。よって、酸素ガス流路２２の断面積を大きく確保して、酸素ガスの流量を確保することができる。
また、当接部４５の幅Ｓ２を一対の脚部４３，４３の幅Ｓ３より広げることで、正電極層１３に当接させる面積を大きく確保する。よって、導電性を高めることができる。
このように、酸素ガスの流量を確保するとともに、導電性を高めることで、燃料電池１０の発電効果を高めることができる。
【００３８】
さらに、凸条部４２を、図２で説明したように、ほぼ直線状に延びた突起とすることで、当接部４５を成形する際に、凸条部４５の平坦拡張頂部４６を幅方向（白抜き矢印の方向）にのみ広げるだけでよい。
これにより、凸条部４２の平坦拡張頂部４６（一対の張出部４４，４４および当接部４５）の肉厚Ｔ１を、脚部４３の肉厚Ｔ２と比較して殆ど薄くする必要がない。すなわち、当接部４５の肉厚Ｔ１を、脚部４３の肉厚Ｔ２ととほぼ同一にすることで、平坦拡張頂部４６（特に、当接部４５）の剛性を確保して、平坦拡張頂部４６の破損を防止する。
【００３９】
ここで、従来技術のように、半球状の頂部を放射状に３６０°の範囲で押し広げようとうすると、頂部に凹凸（すなわち、皺）が発生して平坦に成形することは難しい。頂部に凹凸が発生すると、頂部を正電極層に良好に当接（接触）させることは難しい。
これにより、正電極層に当接させる面積を大きくすることが難しく、導電性を高め難い。
【００４０】
これに対して、セパレータ１５によれば、凸条部４２の平坦拡張頂部４６（特に、当接部４５）を幅方向（白抜き矢印方向）にのみ広げるだけなので、当接部４５を好適に平坦化することが可能になる。
これにより、正電極層１３に当接させる面積を大きくして、導電性を高めることができる。
【００４１】
次に、本発明に係る燃料電池用セパレータの製造方法を図４〜図１４に基づいて説明する。
図４（ａ），（ｂ）は本発明に係る燃料電池用セパレータ（第１実施の形態）の製造方法を示す第１作用説明図である。
（ａ）において、第１成形型５０のブランクホルダ５１に板状素材（ブランク材）５２を載せ、ダイ５３を矢印ａの如く下降させる。
【００４２】
（ｂ）において、板状素材５２をダイ５３で押さえ付けた後、ブランクホルダ５１およびダイ５３を矢印ａの如く下降する。
これにより、ブランクホルダ５１およびダイ５３とともに、板状素材５２を矢印ａの如く下降させる。
【００４３】
図５（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第２作用説明図である。
（ａ）において、ブランクホルダ５１およびダイ５３を下降することで、パンチ５４がブランクホルダ５１から突出する。
パンチ５４が突出することで、板状素材５２の面５２ａに対してほぼ直交する方向に第１予備凸条部（凸条部）５５を突出させる。
【００４４】
この第１予備凸条部５５は、紙面に直交する方向に延びた直線状の突起である。このため、従来技術のように板状素材から球体状の突起を成形する場合と比較して、第１予備凸条部５５の肉厚を大きく確保することができる。
第１予備凸条部５５を形成した後、ブランクホルダ５１およびダイ５３とともに、板状素材５２を矢印ｂの如く上昇させる。
【００４５】
（ｂ）において、第１成形型５０を型開きし、第１予備凸条部５５を成形した板状素材５２を第１成形型５０から外す。
第１予備凸条部５５は、面５２ａに対してほぼ直角に立ち上げた一対の脚部５６，５６と、それぞれの脚部５６，５６の上端５６ａ，５６ａに掛け渡した湾曲状の湾曲頂部（頂部）５７とからなる。
湾曲頂部５７は、長さをＬ１、肉厚をＴ３で形成した部位である。
【００４６】
図６（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第３作用説明図である。
（ａ）において、第１予備凸条部５５を成形した板状素材５２を、第２成形型６０に搬送した後、この板状素材５２を第２成形型６０のブランクホルダ６１に矢印ｃの如く載せ、ダイ６２を矢印ｄの如く下降させる。
【００４７】
（ｂ）において、板状素材５２をダイ６２で押さえ付けた後、ブランクホルダ６１およびダイ６２を矢印ｅの如く下降する。
これにより、ブランクホルダ６１およびダイ６２とともに、板状素材５２を矢印ｅの如く下降させる。
【００４８】
図７（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第４作用説明図である。
（ａ）において、ブランクホルダ６１およびダイ６２を下降することで、押さえパンチ６３をブランクホルダ６１から突出させる。これにより、押さえパンチ６３を第１予備凸条部５５内に差し込む。
押さえパンチ６３は、頂部６３ａの中央６３ｂに凹部６４を備える。
【００４９】
押さえパンチ６３を第１予備凸条部５５内に差し込んだ後、パンチ６５を矢印ｆの如く下降させる。
パンチ６５は、下部６５ａの中央６５ｂに突起６６を備える。突起６６は、押さえパンチ６３の凹部６４に対応する位置に設けられている。
【００５０】
（ｂ）において、パンチ６５の突起６６で湾曲頂部５７のほぼ中央５７ａ（（ａ）参照）を押圧することで、湾曲頂部５７のほぼ中央５７ａを、第１予備凸条部（（ａ）参照）の突出方向と逆方向に押圧する。
これにより、湾曲頂部５７のほぼ中央５７ａを、押さえパンチ６３の凹部６４内に折り曲げて、凹み６７を成形する。
【００５１】
湾曲頂部５７のほぼ中央に凹み６７を成形することで、第１予備凸条部５５（（ａ）参照）は第２予備凸条部（凸条部）６８に成形される。
次に、パンチ６５を矢印ｇの如く上昇させた後、ブランクホルダ６１およびダイ６２とともに、板状素材５２を矢印ｈの如く上昇させる。
【００５２】
図８は本発明に係る第１実施の形態の製造方法を示す第５作用説明図である。第２成形型６０を型開きし、第２予備凸条部６８を成形した板状素材５２を第２成形型６０から外す。
第２予備凸条部６８は、板状素材５２の面５２ａに対してほぼ直角に立ち上げた一対の脚部５６，５６と、それぞれの脚部５６，５６の上端５６ａ、５６ａに掛け渡したほぼＭ字形のＭ字状頂部（頂部）６９とからなる。
Ｍ字状頂部６９は、長さをほぼＬ２、肉厚をほぼＴ４で形成した部位である。
【００５３】
ここで、Ｍ字状頂部６９は、湾曲頂部５７（図７（ａ）参照）のほぼ中央を折り曲げるだけで凹み６７を形成したものである。
よって、Ｍ字状頂部６９の長さＬ２は、湾曲頂部５７の長さＬ１（図５（ｂ）参照）とほぼ同じ長さであり、Ｍ字状頂部６９の肉厚Ｔ４は、湾曲頂部５７の肉厚Ｔ３（図５（ｂ）参照）とほぼ同一である。
【００５４】
図９（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第６作用説明図である。
（ａ）において、第２予備凸条部６８を成形した板状素材５２を、第３成形型７０に搬送した後、板状素材５２を第３成形型７０のブランクホルダ７１に矢印ｉの如く載せ、ダイ７２を矢印ｊの如く下降させる。
（ｂ）において、板状素材５２をダイ７２で押さえ付けた後、ブランクホルダ７１およびダイ７２を矢印ｊの如く下降する。
これにより、ブランクホルダ７１およびダイ７２とともに、板状素材５２を矢印ｊの如く下降させる。
【００５５】
図１０（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第７作用説明図である。
（ａ）において、ブランクホルダ７１およびダイ７２を下降することで、押さえパンチ７３をブランクホルダ７１から突出させる。これにより、押さえパンチ７３を第２予備凸条部６８内に差し込ませて、押さえパンチ７３の頂部７３ａを凹み６７の裏面６７ａに当接させる。
【００５６】
押さえパンチ７３は、頂部７３ａを平坦に形成したものであり、さらに幅Ｗ１を第２予備凸条部６８の幅より狭く形成したものである。
押さえパンチ７３の幅Ｗ１を第２予備凸条部６８の幅より狭く形成することで、第２予備凸条部６８と押さえパンチ７３との間に隙間７８，７８を形成する。
【００５７】
押さえパンチ７３を第２予備凸条部６８内に差し込んだ後、パンチ７４を矢印ｋの如く下降させる。
パンチ７４は、下部７４ａを中央７４ｂから両側部７４ｃ，７４ｃに向けて傾斜角θの上り勾配に形成したものである。
【００５８】
（ｂ）において、パンチ７４の下部７４ａでＭ字状頂部６９を押圧する。詳しくは、パンチ７４の下部７４ａで凹み６７の両側部６９ａ，６９ａを第２予備凸条部６８（（ａ）参照）の突出方向と逆方向に押圧する。
【００５９】
ここで、パンチ７４の下部７４ａを中央７４ｂから両側部７４ｃ，７４ｃに向けて傾斜角θ（（ａ）参照）の上り勾配に形成したので、Ｍ字状頂部６９の両側部６９ａ，６９ａをそれぞれ外側に向けて幅方向（白抜き矢印方向）に良好に折り曲げる。
両側部６９ａ，６９ａが外側に向けて張り出し、Ｍ字状頂部６９はほぼ平坦に成形される。これにより、Ｍ字状頂部６９は拡張頂部（頂部）７５に成形される。
【００６０】
このように、両側部６９ａ，６９ａを両側部のみに広げるだけで、従来技術のように放射状に広げる必要がないので、両側部６９ａ，６９ａの肉厚が薄くなりすぎて破損することを防ぐことができ、かつ両側部６９ａ，６９ａに凹凸（すなわち、皺）が発生することを防ぐことができる。
【００６１】
ところで、押さえパンチ７３の幅Ｗ１を第２予備凸条部６８（（ａ）参照）の幅より狭く形成して、第２予備凸条部６８と押さえパンチ７３との間に隙間７８，７８（（ａ）参照）を形成する。
よって、両側部６９ａ，６９ａが外側に向けて張り出す際に、一対の脚部５６，５６を内側に折り曲げて、一対の脚部５６，５６の内面５６ｂ，５６ｂを押さえパンチ７３の両側面７３ｂ，７３ｂに当接させる。
当接させることで、一対の脚部５６，５６の間隔を狭くする。
【００６２】
このように、Ｍ字状頂部６９をほぼ平坦に成形して拡張頂部７５に成形するとともに、一対の脚部５６，５６の間隔を狭くすることで、（ａ）に示す第２予備凸条部６８を第３予備凸条部（凸条部）７７に成形する。
次に、パンチ７４を矢印ｌの如く上昇させた後、ブランクホルダ７１およびダイ７２とともに、板状素材５２を矢印ｍの如く上昇させる。
【００６３】
図１１は本発明に係る第１実施の形態の製造方法を示す第８作用説明図である。
第３成形型７０を型開きし、第３予備凸条部７７を成形した板状素材５２を第３成形型７０から外す。
第３予備凸条部７７は、板状素材５２の面５２ａに対して立ち上げた一対の脚部５６，５６と、それぞれの脚部５６，５６の上端５６ａ，５６ａに掛け渡したほぼ平坦な拡張頂部７５とからなる。
拡張頂部７５は、長さをほぼＬ３、肉厚をほぼＴ５で形成した部位である。
【００６４】
ここで、拡張頂部７５は、図１０（ａ）に示すＭ字状頂部６９の両側部６９ａ，６９ａを、それぞれ外側に向けて幅方向に折り曲げるのみで、ほぼ平坦に成形した部位である。
よって、拡張頂部７５の長さＬ３は、図８に示すＭ字状頂部６９の長さＬ２とほぼ同じ長さであり、拡張頂部７５の肉厚Ｔ５は、図８に示すＭ字状頂部６９の肉厚Ｔ４とほぼ同一である。
【００６５】
図１２（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第９作用説明図である。
（ａ）において、第３予備凸条部７７を成形した板状素材５２を、第４成形型８０に搬送した後、この板状素材５２を第４成形型８０のブランクホルダ８１に矢印ｎの如く載せ、ダイ８２を矢印ｏの如く下降させる。
（ｂ）において、板状素材５２をダイ８２で押さえ付けた後、ブランクホルダ８１およびダイ８２を矢印ｐの如く下降する。
これにより、ブランクホルダ８１およびダイ８２とともに、板状素材５２を矢印ｐの如く下降させる。
【００６６】
図１３（ａ），（ｂ）は本発明に係る第１実施の形態の製造方法を示す第１０作用説明図である。
（ａ）において、ブランクホルダ８１およびダイ８２を下降することで、押さえパンチ８３をブランクホルダ８１から突出させる。これにより、押さえパンチ８３を第３予備凸条部７７内に差し込ませて、押さえパンチ８３の頂部８３ａを凹み６７の裏面６７ａに当接させる。
押さえパンチ８３は、頂部８３ａを平坦に形成したものである。
【００６７】
また、押さえパンチ８３は、幅Ｗ２を、図１０（ａ）に示す押さえパンチ７３の幅Ｗ１とほぼ同一で、第３予備凸条部７７の幅より僅かに小さく形成したものである。
よって、押さえパンチ８３の両側部が一対の脚部５６，５６間に接触する。
【００６８】
押さえパンチ８３を第３予備凸条部７７内に差し込んだ後、パンチ８４を矢印ｑの如く下降させる。
パンチ８４は、下部８４ａを平坦に形成したものである。
【００６９】
（ｂ）において、パンチ８４の下部８４ａで拡張頂部７５を押圧する。詳しくは、パンチ８４の下部８４ａで拡張頂部７５（図１３（ａ）参照）の両側部７５ａ，７５ａを第３予備凸条部７７（（ａ）参照）の突出方向と逆方向に押圧する。
パンチ８４の下部８４ａは平坦なので、拡張頂部７５の両側部７５ａ，７５ａをそれぞれ外側に向けて幅方向（白抜き矢印方向）に折り曲げる。
【００７０】
パンチ８４の下部８４ａと押さえパンチ８３の頂部８３ａとで、両側部７５ａ，７５ａを挟持することで平坦に形成する。
このように、両側部７５ａ，７５ａを両側部のみに広げるだけで、従来技術のように放射状に広げる必要がないので、両側部７５ａ，７５ａの肉厚が薄くなりすぎて破損することを防ぐことができ、かつ両側部７５ａ，７５ａに凹凸（すなわち、皺）が発生することを防ぐことができる。
【００７１】
同時に、一対の脚部５６，５６の内面５６ｂ，５６ｂを押さえパンチ８３の両側面８３ｂ，８３ｂに当接させて倣わせる。
これにより、一対の脚部５６，５６を直線状に立ち上げた状態にして、一対の脚部４３，４３（図２、図３も参照）に成形する。
【００７２】
このように、両側部７５ａ，７５ａを平坦に成形するとともに、一対の脚部５６，５６を一対の脚部４３，４３（図２、図３も参照）に成形することで、（ａ）に示す第３予備凸条部７７を凸条部４２（図２、図３も参照）に成形する。
板状素材５２に凸条部４２を成形することで、板状素材５２がセパレータ１５になる。
次に、パンチ８４を矢印ｒの如く上昇させた後、ブランクホルダ８１およびダイ８２とともに、セパレータ１５を矢印ｓの如く上昇させる。
【００７３】
図１４は本発明に係る第１実施の形態の製造方法を示す第１１作用説明図である。
第４成形型８０を型開きし、凸条部４２を成形したセパレータ１５を第４成形型８０から外す。
凸条部４２は、セパレータ１５の面４１に対してほぼ直角に立ち上げた一対の脚部４３，４３と、それぞれの脚部４３，４３の上端４３ａ，４３ａに掛け渡した平坦拡張頂部４６とからなる。
【００７４】
平坦拡張頂部４６は、長さをほぼＬ４、肉厚をほぼＴ１で形成した部位である。
この平坦拡張頂部４６は、図２で説明したように、一対の張出部４４，４４および当接部４５で構成したものである。
【００７５】
ここで、平坦拡張頂部４６を構成する当接部４５は、図１３（ａ）に示す拡張頂部７５の両側部７５ａ，７５ａを、それぞれ外側に向けて幅方向にのみ折り曲げただけで、平坦に成形した部位である。
よって、平坦拡張頂部４６の長さＬ４は、拡張頂部７５の長さＬ３とほぼ同じ長さであり、平坦拡張頂部４６の肉厚Ｔ１は、拡張頂部７５の肉厚Ｔ５とほぼ同一である。
【００７６】
以上説明したように、セパレータ１５の製造方法によれば、複数の第１予備凸条部５５（図５参照）をほぼ直線状に成形した後、凸条部５５の湾曲頂部５７中央に凹み６７（図７（ｂ）参照）を成形し、その後凹み６７の両側部６９ａ，６９ａ（図１０参照）を外側に向けて幅方向にのみ張り出すようにした。
【００７７】
これにより、従来技術のように、突起部の頂部を放射状に広げる必要がないので、湾曲頂部５７の肉厚Ｔ３（図５（ｂ）参照）が薄くなりすぎて破損することを防ぐことができ、かつ凹凸（すなわち、皺）が発生することを防ぐことができる。
したがって、当接部４５（図３参照）を正電極層１３に当接可能に良好に平坦にし、正電極層１３に当接させる面積を増やすことができる。
【００７８】
加えて、第１予備凸条部５５の湾曲頂部５７中央に凹み６７を成形し、凹み６７の両側部６９ａ，６９ａを外側に向けて幅方向に張り出すようにしたので、湾曲頂部５７を効率よくスムーズに平坦にすることができる。
【００７９】
また、図３に示す凸条部４２のうち、平坦拡張頂部４６を除いた部位、すなわち一対の脚部４３，４３を広げる必要がないので、凸条部４２間の酸素ガス流路用溝２１の幅Ｓ３を大きく確保することが可能になる。
これにより、正電極層１５に当接させる面積を大きく確保して、導電性を高めるとともに酸素ガス流路２２（図３参照）を大きく確保することができる。
【００８０】
また、当接部４５を平坦に成形する際に、先ず図１０に示すように凹み６７の両側部６９ａ，６９ａを外側に向けてラフに予備成形し、次に図１３に示すように両側部６９ａ，６９ａを平坦に成形した。
このように、凹み６７の両側部６９ａ，６９ａを平坦にする工程を２つに分けることにより、凹み６７の両側部６９ａ，６９ａを平坦に成形する際に、成形荷重を各工程毎に分けて頂部にかけることができる。
【００８１】
したがって、両側部６９ａ，６９ａに成形荷重を集中的にかける必要がないので、図１３（ａ）に示す一対の脚部５６，５６や、図１３（ｂ）に示す一対の脚部４３，４３を成形荷重で予期せぬ方向に座屈変形することを防止することができる。
【００８２】
次に、燃料電池用セパレータの第２実施の形態を図１５に基づいて説明する。図１５は本発明に係る燃料電池用セパレータ（第２実施の形態）を示す断面図である。なお、第２実施の形態において、第１実施の形態と同じ構成部材については同一符号を付して説明を省略する。
第２実施の形態の燃料電池用セパレータ９０は、第１実施の形態のセパレータ１５（図３参照）に相当するもので、凸条部４２に代えて凸条部９２を形成したものである。
【００８３】
凸条部９２は、脚部４３，４３から外側に向けて張出部９４，９４を張り出し、それぞれの張出部９４，９４に当接部９５を掛け渡し、張出部９４，９４に当接部９５の両側部９５ａ，９５ａを当接させたものである。
ここで、一対の張出部９４，９４および当接部９５で平坦拡張頂部（頂部）９６を構成する。
【００８４】
この第２実施の形態の燃料電池用セパレータ９０は、張出部９４，９４に当接部９５の両側部９５ａ，９５ａを当接させることで、張出部９４，９４と当接部９５の両側部９５ａ，９５ａとの間に隙間がないようにしたものであり、この点が第１実施の形態のセパレータ１５（図３参照）と異なるだけで、その他の構成は第１実施の形態と同様である。
なお、第１実施の形態のセパレータ１５は、図３に示すように張出部４４，４４と当接部４５の両側部との間に所定の隙間を備える。
第２実施の形態のセパレータ９０によれば、第１実施の形態と同様の効果を得ることができる。
【００８５】
なお、前記実施の形態では、当接部４５を平坦に成形する際に、先ず図１０に示すように凹み６７の両側部６９ａ，６９ａを外側に向けてラフに予備成形し、次に図１３に示すように両側部６９ａ，６９ａを平坦に成形した例について説明したが、これに限らないで、凹み６７の両側部６９ａ，６９ａを一回の成形で平坦にすることも可能である。
二回の成形工程を、一回の成形工程に減らすことができるので、成形工程の簡素化できる。
【００８６】
【発明の効果】
本発明は上記構成により次の効果を発揮する。
請求項１は、凸条部をほぼ直線状に延ばし、一対の脚部の上端から外側に向けて張出部を張り出した。これら張出部の上端に当接部を掛け渡し、この当接部を電極層に当接させるように構成した。
当接部の両側部を一対の脚部の外側に向けて幅方向に張り出すことで、一対の脚部の間隔を狭く抑えた状態で、当接部の幅を一対の脚部の幅より大きく広げることが可能になる。
【００８７】
このように、一対の脚部の間隔を狭く抑えることで、凸条部間のガス流路用溝を大きく確保して、ガスの流量を良好に確保することができる。
また、当接部の幅を一対の脚部の幅より大きく広げることで、電極層に当接させる面積を大きく確保し、導電性を高めることができる。
【００８８】
さらに、凸条部を、ほぼ直線状に延びた突起とすることで、当接部を成形する際に、凸条部の頂部を幅方向にのみ広げるだけでよい。
これにより、従来技術のように、半球状の頂部を放射状に３６０°の範囲で押し広げる必要がない。
したがって、頂部から当接部を成形する際に、頂部が薄くなりすぎて破損することを防ぐことができ、加えて頂部を平坦に好適に広げ、電極層に当接させる面積を十分に確保して導電性を高めることができる。
【００８９】
請求項２は、当接部の肉厚を、脚部の肉厚ととほぼ同一にすることで、当接部の剛性を確保するように構成した。これにより、当接部が破損することをより確実に防ぐことができる。
【００９０】
請求項３は、ほぼ直線状に延びた凸条部を成形した後、凸条部の頂部中央に凹みを成形し、その後凹みの両側部を外側に向けて幅方向にのみ張り出すようにした。
これにより、従来技術のように、頂部を放射状に広げる必要がないので、頂部の肉厚が薄くなりすぎて破損することを防ぐことができ、かつ凹凸（すなわち、皺）が発生することを防ぐことができる。
したがって、頂部を電極層に当接可能に良好に平坦にし、正電極層又は負電極層に当接させる面積を増やすことができる。
【００９１】
また、凸条部のうち、頂部を除いた部位を広げる必要がないので、凸条部間のガス流路用溝の幅を大きく確保することができる。
これにより、電極層に当接させる面積を大きく確保して、導電性を高めるとともにガス流路を大きく確保することができる。
【００９２】
請求項４は、請求項３と同様に、ほぼ直線状に延びた凸条部を成形した後、凸条部の頂部中央に凹みを成形し、その後凹みの両側部を外側に向けて幅方向にのみ張り出すようにした。
これにより、従来技術のように、頂部を放射状に広げる必要がないので、頂部の肉厚が薄くなりすぎて破損することを防ぐことができ、かつ凹凸（すなわち、皺）が発生することを防ぐことができる。
したがって、頂部を電極層に当接可能に良好に平坦にし、正電極層又は負電極層に当接させる面積を増やすことができる。
【００９３】
また、凸条部のうち、頂部を除いた部位を広げる必要がないので、凸条部間のガス流路用溝の幅を大きく確保することが可能になる。
これにより、電極層に当接させる面積を大きく確保して、導電性を高めるとともにガス流路を大きく確保することができる。
【００９４】
加えて、請求項４によれば、頂部を平坦に成形する際に、凹みの両側部を外側に向けてラフに予備成形する工程と、頂部を平坦に成形する工程との２工程に分けた。
これにより、頂部を平坦に成形する際に、成形荷重を各工程毎に分けて頂部にかけることができる。
したがって、頂部に成形荷重を集中的にかける必要がないので、成形荷重で凸条部の脚部が座屈変形する虞がなく、生産性の向上を図ることができる。
【図面の簡単な説明】
【図１】本発明に係る燃料電池用セパレータ（第１実施の形態）を備えた燃料電池を示す分解斜視図
【図２】本発明に係る燃料電池用セパレータ（第１実施の形態）の要部を示す斜視図
【図３】本発明に係る燃料電池用セパレータ（第１実施の形態）を示す断面図
【図４】本発明に係る燃料電池用セパレータ（第１実施の形態）の製造方法を示す第１作用説明図
【図５】本発明に係る第１実施の形態の製造方法を示す第２作用説明図
【図６】本発明に係る第１実施の形態の製造方法を示す第３作用説明図
【図７】本発明に係る第１実施の形態の製造方法を示す第４作用説明図
【図８】本発明に係る第１実施の形態の製造方法を示す第５作用説明図
【図９】本発明に係る第１実施の形態の製造方法を示す第６作用説明図
【図１０】本発明に係る第１実施の形態の製造方法を示す第７作用説明図
【図１１】本発明に係る第１実施の形態の製造方法を示す第８作用説明図
【図１２】本発明に係る第１実施の形態の製造方法を示す第９作用説明図
【図１３】本発明に係る第１実施の形態の製造方法を示す第１０作用説明図
【図１４】本発明に係る第１実施の形態の製造方法を示す第１１作用説明図
【図１５】本発明に係る燃料電池用セパレータ（第２実施の形態）を示す断面図
【図１６】従来のセパレータを示す平面図
【図１７】従来のセパレータの製造方法を示す説明図
【図１８】従来のセパレータの半球状の頂部を平坦に押し広げる例を説明する図
【符号の説明】
１０…燃料電池、１２…電解質膜、１３…正電極層、１４…負電極層、１５，９０…燃料電池用セパレータ（正極用のセパレータ）、１６…燃料電池用セパレータ（負極用のセパレータ）、２１…ガス流路用溝（酸素ガス流路用溝）、２２…ガス流路（酸素ガス流路）、４１…セパレータ面、４２，９２…凸条部、４３…脚部、４３ａ…脚部の上端、４４，９４…張出部、４４ａ…張出部の上端、４５，９５…当接部、４６，９６…頂部（平坦拡張頂部）、５２…板状素材、５２ａ…板状素材の面、５５…凸条部（第１予備凸条部）、５７…頂部（湾曲頂部）、５７ａ…頂部のほぼ中央、６７…凹み、６８…凸条部（第２予備凸条部）、６９…頂部（Ｍ字状頂部）、６９ａ…両側部、７５…頂部（拡張頂部）、７７…凸条部（第３予備凸条部）、Ｔ１…当接部の肉厚、Ｔ２…脚部の肉厚。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell separator that constitutes a cell module of a fuel cell by laminating positive and negative electrode layers on both sides of an electrolyte membrane and sandwiching these layers from both sides, and a method of manufacturing the same.
[0002]
[Prior art]
A fuel cell has a structure in which a positive electrode layer and a negative electrode layer are laminated on both sides of an electrolyte membrane, and a separator is brought into contact with each of the positive and negative electrode layers to form a cell module. It is.
[0003]
Here, it is necessary to contact oxygen gas with the positive electrode layer. For this reason, a gas flow path for introducing oxygen gas is formed between the positive electrode layer and the separator by bringing the separator into contact with the positive electrode layer.
On the other hand, it is necessary to contact hydrogen gas with the negative electrode layer. Therefore, a gas flow path for introducing hydrogen gas between the negative electrode layer and the separator is formed by bringing the separator into contact with the negative electrode layer.
[0004]
As this separator, a separator provided with a plurality of protrusions on its surface is known (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2000-67888 (page 3-4, FIGS. 1-2)
[0006]
Patent Document 1 will be described in detail with reference to the following drawings.
FIG. 16 is a plan view showing a conventional separator.
A plurality of projections 102 are provided on the surface 101 of the separator 100 (... indicate a plurality), and the tops 103 projecting in a hemispherical shape are flattened by flattening the tops 103. Overhang along the surface of the positive electrode layer or the negative electrode layer.
By flattening the tops 103..., The area of contact (contact) with the surface of the positive electrode layer or the negative electrode layer increases.
Therefore, the conductivity between the positive and negative electrode layers and the separator 100 can be increased.
[0007]
FIGS. 17A and 17B are explanatory views showing a conventional method for manufacturing a separator.
In (a), a plurality of projections 102 are provided on the surface 101 of the separator 100, and the tops 103 of the projections 102 are projected in a hemispherical shape.
When projecting the projection 103, the thickness t 1 of the top 103 is formed to be smaller than the plate thickness t 2 of the base of the separator 100.
[0008]
In (b), the tops 103 of the projections 102 are pressed by a flat punch 104 in the direction opposite to the direction in which the projections 102 project, as indicated by arrows.
This flattenes the tops 103... To increase the area in contact with the surface of the positive electrode layer or the negative electrode layer.
Here, as shown in (a), the thickness t1 of the top 103 is made thinner than the thickness t2 of the base, so that the hemispherical top 103 is flattened and expanded by pressing with the flat punch 104. (See also FIG. 16).
[0009]
By forming the bulging portion 105 by flattening and expanding the top portion 103, the area of contact (contact) with the surface of the positive and negative electrode layers is increased without increasing the outer diameter of the protruding portion 102.
Since it is not necessary to increase the outer diameter of the projection, a gas flow path for oxygen gas or hydrogen gas can be secured.
In addition, by increasing the area in contact with (contacting) the surface of the positive / negative electrode layer, it is possible to increase the conductivity.
[0010]
[Problems to be solved by the invention]
FIG. 18 is a view for explaining an example in which a hemispherical top of a conventional separator is spread flat.
By pressing the top 103 of the projection 102 with a plane punch 104 (see FIG. 17B), the hemispherical top 103 is radially pushed out in the range of 360 ° as indicated by an arrow, and is spread on the outer periphery 106 of the projection 102. The bulge 105 is formed in an annular shape along with the bulge 105.
Here, in order to spread the hemispherical top 103 radially in the range of 360 ° as shown by the arrow, the thickness t1 of the top 103 (see FIG. 17A) becomes too thin, and the top 103 may be damaged. There is.
[0011]
In addition, since the hemispherical top 103 is spread radially in the range of 360 ° as shown by the arrow, there is a possibility that unevenness (ie, wrinkles) 107... When the irregularities 107 occur on the top 103, it is difficult to make the top 103 appropriately contact (contact) the surfaces of the positive and negative electrode layers.
For this reason, there has been a demand for practical use of a technique for suitably flattening the top 103.
[0012]
Therefore, an object of the present invention is to provide a fuel cell separator that secures a gas flow path for oxygen gas and hydrogen gas, suitably flattens the top to increase conductivity, and additionally prevents damage to the top. It is to provide a manufacturing method for it.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is to form a gas flow channel between the ridges by providing a plurality of ridges extending substantially linearly on a flat separator surface. In a fuel cell separator in which a gas flow channel groove is formed in a gas flow channel by being brought into contact with a positive electrode layer or a negative electrode layer, the protruding ridge portion is formed by a pair of raised substantially perpendicular to the separator surface. From the legs, the overhanging portions projecting outward from the upper ends of the respective legs, and the abutment portions that extend over the upper ends of the respective overhangs so as to be parallel to the separator surface. In this case, the contact portion is brought into contact with the positive electrode layer or the negative electrode layer.
[0014]
The ridges were extended substantially linearly, and the overhangs protruded outward from the upper ends of the pair of legs. An abutting portion was extended over the upper ends of these overhanging portions, and the abutting portion was configured to abut on the electrode layer.
The width of the contact portion is set smaller than the width of the pair of leg portions in a state where the distance between the pair of leg portions is narrowed by extending the both side portions of the contact portion toward the outside of the pair of leg portions in the width direction. It becomes possible to widen greatly.
[0015]
As described above, by suppressing the interval between the pair of legs to be small, it is possible to secure a large gas flow channel between the ridges. Further, by making the width of the contact portion larger than the width of the pair of leg portions, it is possible to secure a large area for contact with the electrode layer.
[0016]
Further, by forming the protruding portion as a substantially linearly extending projection, it is only necessary to widen the top of the protruding portion only in the width direction when forming the contact portion.
This eliminates the need to radially expand the hemispherical top portion within a range of 360 ° as in the prior art. Therefore, when the contact portion is formed from the top portion, it is possible to prevent the top portion from being too thin and being damaged, and it is possible to preferably spread the top portion flat.
[0017]
According to a second aspect of the present invention, in the separator, the thickness of the contact portion is substantially equal to the thickness of the leg portion.
[0018]
By making the thickness of the contact portion substantially the same as the thickness of the leg portion, the rigidity of the contact portion is ensured, thereby preventing the contact portion from being damaged.
[0019]
Claim 3 is for a fuel cell comprising a gas flow channel groove on a surface facing the positive electrode layer or the negative electrode layer, and a gas flow channel having a gas flow channel groove in contact with the positive and negative electrode layers. In the method of manufacturing a separator, a step of projecting a plurality of substantially linearly extending ridges in a direction substantially perpendicular to the surface of the plate-like material, and forming the gas flow channel between the ridges. Forming a dent in the approximate center of the top by pressing the approximate center of the top of each ridge in the direction opposite to the direction in which the ridge protrudes; By pressing in the opposite direction to the projecting direction, the two side portions are each extended outward in the width direction, and the step of forming the top portion flat so that the top portion can contact the electrode layer. A method for manufacturing a fuel cell separator is provided.
[0020]
Here, as described in the prior art, if the hemispherical top is to be radially pushed and widened within a range of 360 °, the thickness of the top may become too thin and may be damaged. In addition, when trying to spread the hemispherical top portion radially within a range of 360 °, there is a possibility that irregularities (ie, wrinkles) may occur at the top portion, and it is difficult to form the top flat.
[0021]
Therefore, in claim 3, after forming a substantially linearly extending ridge, a dent is formed at the center of the top of the ridge, and then both sides of the dent are projected outward only in the width direction. I made it.
Accordingly, unlike the related art, the top portion does not need to be spread radially, so that the top portion can be prevented from being excessively thinned and damaged, and the occurrence of unevenness (ie, wrinkles) can be prevented. be able to. Therefore, the top can be satisfactorily flattened so as to be in contact with the electrode layer.
[0022]
In addition, since it is not necessary to widen the portion of the ridge except for the top, it is possible to secure a large width of the gas flow channel between the ridges.
[0023]
A fourth aspect of the present invention is directed to a fuel cell having a gas flow channel groove provided on a surface facing a positive electrode layer or a negative electrode layer, and having the gas flow channel groove as a gas flow channel in contact with the positive and negative electrode layers. In the method of manufacturing a separator, a step of projecting a plurality of substantially linearly extending ridges in a direction substantially perpendicular to the surface of the plate-like material, and forming the gas flow channel between the ridges. Forming a dent in the approximate center of the top by pressing the approximate center of the top of each ridge in the direction opposite to the direction in which the ridge protrudes; By pressing in the opposite direction to the projecting direction, the both side portions are respectively extended outward in the width direction, and the step of forming the top portion almost flat is performed. Pressing in the direction to form a flat surface so as to be able to contact the electrode layer; and To provide a method of manufacturing a pond separator.
[0024]
According to the fourth aspect, similarly to the third aspect, after forming the substantially linearly extending ridge, a dent is formed at the center of the top of the ridge, and then both sides of the dent are directed outward. It overhangs only in the width direction.
Accordingly, unlike the related art, the top portion does not need to be spread radially, so that the top portion can be prevented from being excessively thinned and damaged, and the occurrence of unevenness (ie, wrinkles) can be prevented. be able to. Therefore, the top can be satisfactorily flattened so as to be in contact with the electrode layer.
[0025]
In addition, since it is not necessary to widen the portion of the ridge except for the top, it is possible to secure a large width of the gas flow channel between the ridges.
[0026]
In addition, according to the fourth aspect, when the top is formed flat, it is divided into two steps, a step of rough preforming with both sides of the recess facing outward and a step of forming the top flat. . Accordingly, when the top is formed flat, the forming load can be applied to the top separately for each step.
Therefore, since it is not necessary to apply the forming load intensively to the top portion, it is possible to prevent the legs of the ridge from being buckled by the forming load.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals.
FIG. 1 is an exploded perspective view showing a fuel cell provided with a fuel cell separator (first embodiment) according to the present invention.
As an example, the fuel cell 10 uses a solid polymer electrolyte for the electrolyte membrane 12, stacks a positive electrode layer 13 and a negative electrode layer 14 on the electrolyte membrane 12, and forms a positive electrode separator (for a fuel cell) on the positive electrode layer 13. A cell module 11 is formed by abutting a separator 15 on the negative electrode layer 14 and a separator 16 for a negative electrode (separator for a fuel cell) on the negative electrode layer 14. Battery.
[0028]
The positive electrode separator 15 is provided with oxygen gas flow grooves (gas flow grooves) 21... On a surface 15 a in contact with the positive electrode layer 13. (See FIG. 3) is closed by the positive electrode layer 13 to form an oxygen gas flow path (gas flow path) 22 (see FIG. 3). It is.
Oxygen gas supply holes 23 and 24 on the upper right side of the positive and negative electrode separators 15 and 16 communicate with the oxygen gas flow path 22, and oxygen gas discharge holes 25 and 24 on the lower left side of the positive and negative electrode separators 15 and 16. 26 is communicated.
[0029]
The separator 16 for the negative electrode is provided with a hydrogen gas flow channel groove (gas flow channel groove) (not shown) on the surface 16 a in contact with the negative electrode layer 14. A substantially rectangular member in which a hydrogen gas flow path (gas flow path) (not shown) is formed by closing an opening (not shown) of the flow path groove with the negative electrode layer 14.
The hydrogen gas flow path is communicated with hydrogen gas supply holes 33, 34 on the upper left side of the positive and negative electrode separators 15, 16 and the hydrogen gas discharge holes 35, 34 on the lower right side of the positive and negative electrode separators 15, 16. 36.
[0030]
The positive and negative separators 15 and 16 are members formed of a metal such as aluminum, an aluminum alloy, and stainless steel, for example.
Since the positive and negative separators 15 and 16 have substantially the same configuration, the positive electrode separator 15 will be described below, and the description of the negative electrode separator 16 will be omitted. Hereinafter, the separator 15 for the positive electrode will be simply referred to as a “separator” 15.
[0031]
FIG. 2 is a perspective view showing a main part of the fuel cell separator (first embodiment) according to the present invention.
The separator 15 is provided with a flat separator surface 41 on the surface 15a (see FIG. 1) contacting the positive electrode layer 13, and the separator 15 has a plurality of lines extending substantially linearly in the direction of the outline arrow AA. The grooves 21 for oxygen gas flow passages are formed between the ridges 42 by providing the ridges 42 of the book.
[0032]
The ridge 42 is a projection formed on the separator surface 41 at a predetermined interval S1. The interval S1 between the ridges 42 is the same as the width of the groove 21 for the oxygen gas flow path. The ridge 42 raises a pair of legs 43, 43 from the separator surface 41, projects the projections 44, 44 outward from the respective legs 43, 43, and projects the respective projections 44, 44. And the contact portion 45 is stretched over.
Here, a pair of overhang portions 44, 44 and the contact portion 45 constitute a flat expanded top portion (top portion) 46.
[0033]
By projecting the projecting portions 44, 44 on both sides, the width S2 of the contact portion 45 is ensured to be larger than the width S3 between the pair of leg portions 43, 43.
By forming the contact portion 45 flat and being capable of contacting the positive electrode layer 13 (see FIG. 1), a large contact area for contact with the positive electrode layer 13 is ensured.
[0034]
FIG. 3 is a cross-sectional view showing a fuel cell separator (first embodiment) according to the present invention.
By contacting the contact portion 45 of the separator 15 with the positive electrode layer 13 (shown by an imaginary line), the opening 27 of the oxygen gas flow channel groove 21 formed between the ridges 42 is closed, and the oxygen gas flow An oxygen gas flow path 22 is formed from the road groove 21.
[0035]
The ridge 42 has a pair of legs 43, 43 rising substantially perpendicular to the separator surface 41, and a width direction (open arrow) extending outward from upper ends 43 a, 43 a of the legs 43, 43. (B-B direction) Overhanging portions 44, 44 on both sides projecting in the direction (B-B direction), and abutting portions which are extended over upper ends 44a, 44a of the respective overhanging portions 44, 44 so as to be parallel to the separator surface 41. 45.
[0036]
By providing the projecting portions 44 on both sides, the side portions 45a of the contact portion 45 project in the width direction toward the outside of the pair of legs 43. This allows the width S2 of the abutting portion 45 to be wider than the width S3 of the pair of legs while keeping the width S3 of the pair of legs 43, 43 narrow.
[0037]
By suppressing the width S3 of the pair of legs 43, 43 to be narrow, the width S1 of the oxygen gas flow channel groove 21 (oxygen gas flow channel 22) is ensured to be large. Therefore, it is possible to secure a large cross-sectional area of the oxygen gas flow path 22 and secure a flow rate of the oxygen gas.
In addition, by making the width S2 of the contact portion 45 wider than the width S3 of the pair of leg portions 43, 43, a large area to be brought into contact with the positive electrode layer 13 is ensured. Therefore, conductivity can be increased.
As described above, the power generation effect of the fuel cell 10 can be enhanced by securing the flow rate of the oxygen gas and increasing the conductivity.
[0038]
Further, as described with reference to FIG. 2, by forming the protruding ridge 42 as a substantially linearly extending projection, when the abutting portion 45 is formed, the flat expanded apex 46 of the protruding ridge 45 is moved in the width direction. It only needs to be spread in the direction of the white arrow.
Thereby, the thickness T1 of the flat expanded top portion 46 (the pair of overhang portions 44, 44 and the contact portion 45) of the ridge portion 42 does not need to be reduced as compared with the thickness T2 of the leg portion 43. . That is, by making the thickness T1 of the contact portion 45 substantially equal to the thickness T2 of the leg portion 43, the rigidity of the flat expanded top portion 46 (particularly, the contact portion 45) is secured, and the flat expanded top portion 46 is secured. 46 is prevented from being damaged.
[0039]
Here, as in the prior art, if the hemispherical top is to be spread radially within a range of 360 °, irregularities (ie, wrinkles) are generated at the top, and it is difficult to form the top flat. When the tops have irregularities, it is difficult to make the tops properly contact the positive electrode layer.
Thus, it is difficult to increase the area in contact with the positive electrode layer, and it is difficult to increase conductivity.
[0040]
On the other hand, according to the separator 15, the flat expanded top portion 46 (particularly, the contact portion 45) of the ridge portion 42 is only widened in the width direction (the direction of the white arrow). It can be flattened.
Thereby, the area brought into contact with the positive electrode layer 13 can be increased, and the conductivity can be increased.
[0041]
Next, a method for manufacturing a fuel cell separator according to the present invention will be described with reference to FIGS.
FIGS. 4A and 4B are first operation explanatory views showing a method of manufacturing the fuel cell separator (first embodiment) according to the present invention.
In (a), a plate material (blank material) 52 is placed on a blank holder 51 of a first molding die 50, and a die 53 is lowered as indicated by an arrow a.
[0042]
In (b), after the plate-shaped material 52 is pressed by the die 53, the blank holder 51 and the die 53 are lowered as shown by the arrow a.
As a result, the plate material 52 is lowered together with the blank holder 51 and the die 53 as shown by the arrow a.
[0043]
FIGS. 5A and 5B are second operation explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), the punch 54 projects from the blank holder 51 by descending the blank holder 51 and the die 53.
The projection of the punch 54 causes the first preliminary convex portion (projecting portion) 55 to project in a direction substantially orthogonal to the surface 52 a of the plate-shaped material 52.
[0044]
The first preliminary ridges 55 are linear projections extending in a direction perpendicular to the plane of the paper. For this reason, compared with the case where a spherical projection is formed from a plate-like material as in the related art, it is possible to ensure a large thickness of the first preliminary ridge portion 55.
After forming the first preliminary ridge portion 55, the plate-shaped material 52 is raised together with the blank holder 51 and the die 53 as shown by an arrow b.
[0045]
In (b), the first molding die 50 is opened, and the plate-shaped material 52 on which the first preliminary ridge 55 is molded is removed from the first molding die 50.
The first preliminary ridge portion 55 has a pair of legs 56, 56 rising substantially at right angles to the surface 52 a, and a curved curved top portion extending over upper ends 56 a, 56 a of the respective legs 56, 56. (Top) 57.
The curved top 57 is a portion formed by length L1 and thickness T3.
[0046]
FIGS. 6A and 6B are third operation explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), after the plate-shaped material 52 formed with the first preliminary convex portion 55 is conveyed to the second molding die 60, the plate-shaped material 52 is placed on the blank holder 61 of the second molding die 60 as indicated by an arrow c. And the die 62 is lowered as shown by the arrow d.
[0047]
In (b), after pressing the plate-shaped material 52 with the die 62, the blank holder 61 and the die 62 are lowered as shown by the arrow e.
As a result, the plate material 52 is lowered together with the blank holder 61 and the die 62 as shown by the arrow e.
[0048]
FIGS. 7A and 7B are fourth operation explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), the holding punch 63 is projected from the blank holder 61 by lowering the blank holder 61 and the die 62. Thus, the holding punch 63 is inserted into the first preliminary ridge 55.
The pressing punch 63 has a concave portion 64 at the center 63b of the top portion 63a.
[0049]
After the holding punch 63 is inserted into the first preliminary convex portion 55, the punch 65 is lowered as shown by the arrow f.
The punch 65 has a projection 66 at the center 65b of the lower portion 65a. The protrusion 66 is provided at a position corresponding to the concave portion 64 of the holding punch 63.
[0050]
In (b), when the projection 66 of the punch 65 presses the approximate center 57a (see (a)) of the curved top 57, the approximate center 57a of the curved top 57 is brought into contact with the first preliminary ridge (see (a)). ) Is pressed in the direction opposite to the projecting direction.
As a result, the substantially central portion 57 a of the curved top portion 57 is bent into the concave portion 64 of the holding punch 63 to form the recess 67.
[0051]
By forming the recess 67 substantially in the center of the curved top 57, the first preliminary ridge 55 (see (a)) is formed into the second preliminary ridge (ridge) 68.
Next, after the punch 65 is raised as shown by the arrow g, the plate material 52 is raised together with the blank holder 61 and the die 62 as shown by the arrow h.
[0052]
FIG. 8 is a fifth operation explanatory view showing the manufacturing method according to the first embodiment of the present invention. The second forming die 60 is opened, and the plate-shaped material 52 on which the second preliminary convex portion 68 has been formed is removed from the second forming die 60.
The second preliminary ridge 68 extends over a pair of legs 56, 56 rising substantially at right angles to the surface 52 a of the plate-shaped material 52 and upper ends 56 a, 56 a of the respective legs 56, 56. A substantially M-shaped M-shaped top (top) 69 is provided.
The M-shaped top 69 is a portion formed with a length of approximately L2 and a thickness of approximately T4.
[0053]
Here, the M-shaped top 69 is formed by simply bending substantially the center of the curved top 57 (see FIG. 7A) to form the recess 67.
Therefore, the length L2 of the M-shaped top 69 is substantially the same as the length L1 of the curved top 57 (see FIG. 5B), and the thickness T4 of the M-shaped top 69 is (See FIG. 5B).
[0054]
FIGS. 9A and 9B are sixth operation explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), after the plate-shaped raw material 52 on which the second preliminary convex portion 68 has been formed is conveyed to the third forming die 70, the plate-shaped raw material 52 is placed on the blank holder 71 of the third forming die 70 as shown by an arrow i. Then, the die 72 is lowered as shown by the arrow j.
In (b), after pressing the plate-shaped material 52 with the die 72, the blank holder 71 and the die 72 are lowered as indicated by the arrow j.
Thereby, the plate material 52 is lowered together with the blank holder 71 and the die 72 as shown by the arrow j.
[0055]
FIGS. 10A and 10B are seventh operation explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), the holding punch 73 is projected from the blank holder 71 by lowering the blank holder 71 and the die 72. Thereby, the holding punch 73 is inserted into the second preliminary convex portion 68, and the top portion 73 a of the holding punch 73 is brought into contact with the back surface 67 a of the recess 67.
[0056]
The holding punch 73 has a top portion 73a formed flat, and a width W1 formed smaller than the width of the second preliminary ridge portion 68.
By forming the width W1 of the holding punch 73 smaller than the width of the second preliminary ridge 68, the gaps 78, 78 are formed between the second preliminary ridge 68 and the pressing punch 73.
[0057]
After inserting the holding punch 73 into the second preliminary convex portion 68, the punch 74 is lowered as indicated by an arrow k.
The punch 74 has a lower portion 74a formed with an upward slope of an inclination angle θ from the center 74b to both side portions 74c, 74c.
[0058]
In (b), the M-shaped top 69 is pressed by the lower part 74a of the punch 74. Specifically, both sides 69a, 69a of the recess 67 are pressed by the lower portion 74a of the punch 74 in a direction opposite to the direction in which the second preliminary ridge 68 (see (a)) projects.
[0059]
Here, since the lower part 74a of the punch 74 is formed with an upward slope of the inclination angle θ (see (a)) from the center 74b toward the both sides 74c, 74c, the both sides 69a, 69a of the M-shaped top 69 are respectively formed. Fold it outwards in the width direction (the direction of the white arrow).
Both sides 69a, 69a project outward, and the M-shaped top 69 is formed substantially flat. As a result, the M-shaped top 69 is formed into the expanded top (top) 75.
[0060]
As described above, since the side portions 69a, 69a are only spread on both side portions and do not need to be radially spread unlike the related art, it is possible to prevent the side portions 69a, 69a from being excessively thin and from being damaged. And the occurrence of irregularities (ie, wrinkles) on both sides 69a, 69a can be prevented.
[0061]
By the way, the width W1 of the pressing punch 73 is formed smaller than the width of the second preliminary convex portion 68 (see (a)), and the gaps 78, 78 (between the second preliminary convex portion 68 and the pressing punch 73 are formed. (See (a)).
Therefore, when the both sides 69 a, 69 a project outward, the pair of legs 56, 56 are bent inward to hold the inner surfaces 56 b, 56 b of the pair of legs 56, 56 on both sides 73 b of the punch 73. , 73b.
The contact makes the interval between the pair of legs 56, 56 narrow.
[0062]
As described above, the M-shaped top 69 is formed almost flat to form the expanded top 75, and the interval between the pair of legs 56, 56 is reduced, so that the second preliminary ridge shown in FIG. 68 is formed into a third preliminary ridge (a ridge) 77.
Next, after the punch 74 is raised as shown by the arrow l, the plate material 52 is raised together with the blank holder 71 and the die 72 as shown by the arrow m.
[0063]
FIG. 11 is an eighth operation explanatory view showing the manufacturing method according to the first embodiment of the present invention.
The third mold 70 is opened, and the plate-shaped material 52 on which the third preliminary ridge 77 has been formed is removed from the third mold 70.
The third preliminary ridge 77 is a pair of legs 56, 56 that are raised with respect to the surface 52 a of the plate-shaped material 52, and is substantially flat across the upper ends 56 a, 56 a of the respective legs 56, 56. And an extended top 75.
The expanded top portion 75 is a portion having a length of approximately L3 and a thickness of approximately T5.
[0064]
Here, the expanded top portion 75 is a substantially flat portion formed by simply bending both side portions 69a, 69a of the M-shaped top portion 69 shown in FIG. 10A outward in the width direction.
Therefore, the length L3 of the expanded top 75 is substantially the same as the length L2 of the M-shaped top 69 shown in FIG. 8, and the thickness T5 of the expanded top 75 is set to the M-shaped top 69 shown in FIG. Is substantially the same as the thickness T4.
[0065]
FIGS. 12A and 12B are ninth action explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), after the plate-shaped material 52 on which the third preliminary convex portion 77 has been formed is conveyed to the fourth molding die 80, the plate-shaped material 52 is placed on the blank holder 81 of the fourth molding die 80 as indicated by an arrow n. And the die 82 is lowered as indicated by the arrow o.
In (b), after the plate-shaped material 52 is pressed by the die 82, the blank holder 81 and the die 82 are lowered as shown by the arrow p.
As a result, the plate material 52 is lowered together with the blank holder 81 and the die 82 as shown by the arrow p.
[0066]
FIGS. 13A and 13B are tenth operation explanatory views showing the manufacturing method according to the first embodiment of the present invention.
In (a), the holding punch 83 is made to protrude from the blank holder 81 by lowering the blank holder 81 and the die 82. As a result, the holding punch 83 is inserted into the third preliminary convex portion 77, and the top portion 83 a of the holding punch 83 is brought into contact with the back surface 67 a of the recess 67.
The pressing punch 83 has a top portion 83a formed flat.
[0067]
The pressing punch 83 has a width W2 substantially equal to the width W1 of the pressing punch 73 shown in FIG. 10A and is slightly smaller than the width of the third preliminary ridge 77.
Therefore, both sides of the holding punch 83 come into contact between the pair of legs 56, 56.
[0068]
After inserting the holding punch 83 into the third preliminary ridge 77, the punch 84 is lowered as indicated by the arrow q.
The punch 84 has a lower portion 84a formed flat.
[0069]
In (b), the expanded top portion 75 is pressed by the lower portion 84a of the punch 84. More specifically, the lower portion 84a of the punch 84 presses the side portions 75a, 75a of the expanded top portion 75 (see FIG. 13A) in a direction opposite to the direction in which the third preliminary ridge 77 (see FIG. 13A) projects.
Since the lower portion 84a of the punch 84 is flat, both side portions 75a, 75a of the expanded top portion 75 are bent outward in the width direction (the direction of the white arrow).
[0070]
The lower portion 84a of the punch 84 and the top portion 83a of the holding punch 83 sandwich the both sides 75a, 75a to form a flat surface.
As described above, since the side portions 75a, 75a are only spread on both side portions and do not need to be radially spread as in the related art, it is possible to prevent the side portions 75a, 75a from being excessively thin and from being damaged. And the occurrence of irregularities (ie, wrinkles) on both sides 75a, 75a can be prevented.
[0071]
At the same time, the inner surfaces 56b, 56b of the pair of leg portions 56, 56 are brought into contact with the both side surfaces 83b, 83b of the holding punch 83 to be imitated.
In this way, the pair of legs 56, 56 is formed into a pair of legs 43, 43 (see also FIG. 2 and FIG. 3) in a state where the pair of legs 56 is linearly raised.
[0072]
As described above, by forming both side portions 75a, 75a flat and forming the pair of leg portions 56, 56 into the pair of leg portions 43, 43 (see also FIGS. 2 and 3), (a) is obtained. The third preliminary ridge 77 shown is formed into the ridge 42 (see also FIGS. 2 and 3).
By forming the protruding ridges 42 on the plate-shaped material 52, the plate-shaped material 52 becomes the separator 15.
Next, after raising the punch 84 as shown by the arrow r, the separator 15 is raised together with the blank holder 81 and the die 82 as shown by the arrow s.
[0073]
FIG. 14 is an eleventh operation explanatory view showing the manufacturing method according to the first embodiment of the present invention.
The fourth mold 80 is opened, and the separator 15 on which the ridges 42 are formed is removed from the fourth mold 80.
The ridge 42 has a pair of legs 43, 43 rising substantially at right angles to the surface 41 of the separator 15, a flat expanded top 46 extending over the upper ends 43 a, 43 a of the legs 43, 43. Consists of
[0074]
The flat expanded top portion 46 is a portion having a length of approximately L4 and a thickness of approximately T1.
As shown in FIG. 2, the flat expanded top portion 46 includes a pair of overhang portions 44, 44 and a contact portion 45.
[0075]
Here, the contact portion 45 constituting the flat expanded top portion 46 is flattened only by bending both side portions 75a, 75a of the expanded top portion 75 shown in FIG. It is a molded part.
Therefore, the length L4 of the flat expanded top 46 is substantially the same as the length L3 of the expanded top 75, and the thickness T1 of the flat expanded top 46 is substantially the same as the thickness T5 of the expanded top 75.
[0076]
As described above, according to the method of manufacturing the separator 15, after the plurality of first preliminary ridges 55 (see FIG. 5) are formed in a substantially linear shape, the concave 67 is formed in the center of the curved top 57 of the ridge 55. (See FIG. 7B), and then both side portions 69a, 69a (see FIG. 10) of the recess 67 project outward only in the width direction.
[0077]
As a result, unlike the related art, it is not necessary to radially expand the top of the protrusion, so that it is possible to prevent the thickness T3 (see FIG. 5B) of the curved top 57 from being too thin and being damaged. In addition, the occurrence of unevenness (ie, wrinkles) can be prevented.
Therefore, the contact portion 45 (see FIG. 3) can be satisfactorily flattened so as to be in contact with the positive electrode layer 13, and the area to be in contact with the positive electrode layer 13 can be increased.
[0078]
In addition, a concave 67 is formed at the center of the curved top 57 of the first preliminary convex portion 55, and the both sides 69a, 69a of the recess 67 are projected outward in the width direction, so that the curved top 57 is efficiently formed. It can be smooth and flat.
[0079]
Further, since it is not necessary to expand the portion of the ridge 42 shown in FIG. 3 except for the flat expanded top 46, that is, the pair of legs 43, 43, the oxygen gas flow channel 21 between the ridges 42 is not necessary. Large width S3 can be secured.
Thereby, a large area to be brought into contact with the positive electrode layer 15 can be ensured, the conductivity can be increased, and the oxygen gas flow path 22 (see FIG. 3) can be ensured large.
[0080]
When the contact portion 45 is formed flat, first, both sides 69a, 69a of the recess 67 are roughly preformed outwardly as shown in FIG. 10, and then both sides are formed as shown in FIG. 69a, 69a were formed flat.
As described above, by dividing the process of flattening the both sides 69a, 69a of the recess 67 into two, when forming the both sides 69a, 69a of the recess 67 flat, the forming load is divided for each process. Can be hung on top.
[0081]
Therefore, since it is not necessary to apply a molding load intensively to both side portions 69a, 69a, a pair of leg portions 56, 56 shown in FIG. 13A and a pair of leg portions 43, 43 shown in FIG. Can be prevented from being buckled and deformed in an unexpected direction by a forming load.
[0082]
Next, a second embodiment of the fuel cell separator will be described with reference to FIG. FIG. 15 is a cross-sectional view showing a fuel cell separator (second embodiment) according to the present invention. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The fuel cell separator 90 of the second embodiment corresponds to the separator 15 of the first embodiment (see FIG. 3), and has a ridge 92 formed in place of the ridge 42.
[0083]
The protruding ridges 92 project outwardly from the legs 43, 43, projecting outwards 94, 94, and abut a contact portion 95 on the respective projecting portions 94, 94, and contact the projecting portions 94, 94. The contact portion 95 has both side portions 95a, 95a in contact with each other.
Here, a pair of overhang portions 94, 94 and the contact portion 95 constitute a flat expanded top portion (top portion) 96.
[0084]
In the fuel cell separator 90 according to the second embodiment, the overhang portions 94, 94 are brought into contact with both side portions 95a, 95a of the abutment portion 95, so that the overhang portions 94, 94 and the abutment portion 95 are formed. There is no gap between the both sides 95a, 95a, and only this point is different from the separator 15 of the first embodiment (see FIG. 3), and other configurations are the same as those of the first embodiment. The same is true.
Note that the separator 15 of the first embodiment has a predetermined gap between the overhang portions 44, 44 and both side portions of the contact portion 45 as shown in FIG.
According to the separator 90 of the second embodiment, the same effects as those of the first embodiment can be obtained.
[0085]
In the above-described embodiment, when the contact portion 45 is formed flat, first, as shown in FIG. 10, both sides 69a, 69a of the recess 67 are preformed roughly outward and then rough preformed. Although the example in which the both sides 69a, 69a are formed flat as shown in Fig. 7 has been described, the present invention is not limited to this, and it is also possible to flatten the both sides 69a, 69a of the recess 67 by a single forming.
Since two molding steps can be reduced to one molding step, the molding step can be simplified.
[0086]
【The invention's effect】
The present invention has the following effects by the above configuration.
According to the first aspect of the present invention, the protruding portions are extended substantially linearly, and the protruding portions protrude outward from the upper ends of the pair of leg portions. An abutting portion was extended over the upper ends of these overhanging portions, and the abutting portion was configured to abut on the electrode layer.
The width of the contact portion is set smaller than the width of the pair of leg portions in a state where the distance between the pair of leg portions is narrowed by extending the both side portions of the contact portion toward the outside of the pair of leg portions in the width direction. It becomes possible to widen greatly.
[0087]
In this way, by suppressing the interval between the pair of legs to be small, a large gas flow channel between the protruding ridges can be secured, and the gas flow rate can be favorably secured.
In addition, by increasing the width of the contact portion to be larger than the width of the pair of leg portions, a large area for contact with the electrode layer can be secured, and the conductivity can be increased.
[0088]
Further, by forming the protruding portion as a substantially linearly extending projection, it is only necessary to widen the top of the protruding portion only in the width direction when forming the contact portion.
This eliminates the need to radially expand the hemispherical top portion within a range of 360 ° as in the prior art.
Therefore, when forming the contact portion from the top portion, it is possible to prevent the top portion from becoming too thin and being damaged, and in addition, to appropriately spread the top portion flatly and to secure a sufficient area for contact with the electrode layer. And the conductivity can be increased.
[0089]
In the second aspect, the rigidity of the contact portion is ensured by making the thickness of the contact portion substantially the same as the thickness of the leg portion. This can more reliably prevent the contact portion from being damaged.
[0090]
According to a third aspect of the present invention, after forming the substantially linearly extending ridge, a dent is formed at the center of the top of the ridge, and then both sides of the dent are projected outward only in the width direction. .
Accordingly, unlike the related art, the top portion does not need to be spread radially, so that the top portion can be prevented from being excessively thinned and damaged, and the occurrence of unevenness (ie, wrinkles) can be prevented. be able to.
Therefore, the top portion can be satisfactorily flattened so as to be in contact with the electrode layer, and the area to be in contact with the positive electrode layer or the negative electrode layer can be increased.
[0091]
In addition, since it is not necessary to widen the portion of the ridge except for the top, the width of the gas flow channel between the ridges can be made large.
Accordingly, it is possible to secure a large area to be brought into contact with the electrode layer, to increase conductivity, and to secure a large gas flow path.
[0092]
According to a fourth aspect of the present invention, similarly to the third aspect, after forming a substantially linearly extending ridge, a dent is formed at the center of the top of the ridge, and then both sides of the dent are directed outward in the width direction. Only overhanged.
Accordingly, unlike the related art, the top portion does not need to be spread radially, so that the top portion can be prevented from being excessively thinned and damaged, and the occurrence of unevenness (ie, wrinkles) can be prevented. be able to.
Therefore, the top portion can be satisfactorily flattened so as to be in contact with the electrode layer, and the area to be in contact with the positive or negative electrode layer can be increased.
[0093]
In addition, since it is not necessary to widen the portion of the ridge except for the top, it is possible to secure a large width of the gas flow channel between the ridges.
Accordingly, it is possible to secure a large area to be brought into contact with the electrode layer, to increase conductivity, and to secure a large gas flow path.
[0094]
In addition, according to the fourth aspect, when the top is formed flat, it is divided into two steps, a step of rough preforming with both sides of the recess facing outward and a step of forming the top flat. .
Accordingly, when the top is formed flat, the forming load can be applied to the top separately for each step.
Therefore, since it is not necessary to apply the forming load intensively to the top portion, there is no possibility that the leg portion of the ridge portion is buckled and deformed by the forming load, and the productivity can be improved.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a fuel cell provided with a fuel cell separator (first embodiment) according to the present invention.
FIG. 2 is a perspective view showing a main part of a fuel cell separator (first embodiment) according to the present invention.
FIG. 3 is a cross-sectional view showing a fuel cell separator (first embodiment) according to the present invention.
FIG. 4 is a first operation explanatory view showing a method for manufacturing a fuel cell separator (first embodiment) according to the present invention;
FIG. 5 is a second operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 6 is a third operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 7 is a fourth operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 8 is a fifth operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 9 is a sixth operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 10 is a seventh operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 11 is an eighth operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 12 is a ninth action explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 13 is an explanatory view illustrating a tenth operation of the manufacturing method according to the first embodiment of the present invention.
FIG. 14 is an eleventh operation explanatory view showing the manufacturing method according to the first embodiment of the present invention;
FIG. 15 is a sectional view showing a fuel cell separator (second embodiment) according to the present invention.
FIG. 16 is a plan view showing a conventional separator.
FIG. 17 is an explanatory view showing a conventional separator manufacturing method.
FIG. 18 is a view for explaining an example in which a hemispherical top portion of a conventional separator is spread flat.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... fuel cell, 12 ... electrolyte membrane, 13 ... positive electrode layer, 14 ... negative electrode layer, 15, 90 ... fuel cell separator (positive electrode separator), 16 ... fuel cell separator (negative electrode separator), Reference numeral 21: groove for gas flow path (groove for oxygen gas flow path), 22: gas flow path (oxygen gas flow path), 41: separator surface, 42, 92: convex ridge, 43: leg, 43a: leg Top, 44, 94 ... overhang, 44a ... top of overhang, 45, 95 ... abutment, 46, 96 ... top (flat expanded top), 52 ... plate-like material, 52a ... plate-like material Surface 55: convex portion (first preliminary convex portion), 57: top portion (curved top portion), 57a: approximately center of the top portion, 67: concave portion, 68: convex portion (second preliminary convex portion), 69 ... Top (M-shaped top), 69a ... Both sides, 75 ... Top (expanded top), 77 ... Protrusion (third preliminary ridge) , T1 ... the wall thickness of the contact portion, the thickness of the T2 ... leg.

Claims

By providing a plurality of substantially linearly extending ridges on the flat separator surface, gas flow grooves are formed between the ridges, and the ridges are brought into contact with the positive electrode layer or the negative electrode layer. In the fuel cell separator forming the gas flow channel groove in the gas flow channel,
The ridges are a pair of legs rising substantially at right angles to the separator surface, projecting portions projecting outward from the upper ends of the respective legs, and upper ends of the projecting portions. , Consisting of a contact portion that is extended so as to be parallel to the separator surface,
A separator for a fuel cell, wherein the contact portion is in contact with the positive electrode layer or the negative electrode layer.

2. The fuel cell separator according to claim 1, wherein said separator has a thickness of said contact portion substantially equal to a thickness of said leg portion.

A method for manufacturing a fuel cell separator, comprising a gas flow channel groove on a surface facing the positive electrode layer or the negative electrode layer, and making the gas flow channel groove a gas flow channel by contacting the positive and negative electrode layers. ,
A step of projecting a plurality of substantially linearly extending ridges in a direction substantially orthogonal to the surface of the plate-like material, and forming the gas flow channel between the ridges;
A step of forming a dent at substantially the center of the top by pressing substantially the center of the top of each ridge in the direction opposite to the projecting direction of the ridge,
By pressing both sides of this dent in the direction opposite to the projecting direction of the protruding ridges, the two sides are each projected outward in the width direction, and the top can be brought into contact with the electrode layer. Forming a flat surface on the
A method for producing a fuel cell separator, comprising:

A method for manufacturing a fuel cell separator, comprising a gas flow channel groove on a surface facing the positive electrode layer or the negative electrode layer, and making the gas flow channel groove a gas flow channel by contacting the positive and negative electrode layers. ,
A step of projecting a plurality of substantially linearly extending ridges in a direction substantially orthogonal to the surface of the plate-like material, and forming the gas flow channel between the ridges;
A step of forming a dent at substantially the center of the top by pressing substantially the center of the top of each ridge in the direction opposite to the projecting direction of the ridge,
By pressing both sides of the dent in the direction opposite to the projecting direction of the ridge, the two sides are each extended outward in the width direction, and a step of forming the top almost flat,
By pressing this apex in a direction opposite to the protruding direction of the ridge, a step of forming the top flat so as to be able to contact the electrode layer,
A method for producing a fuel cell separator, comprising: