JP3734208B2 - Iron golf club set and iron golf club headset - Google Patents

Description

【００２２】
また請求項１記載の発明は、さらに前記番手の番号をｍとおいた高摩擦フェース面のゴルフクラブは、ロフト角が２４〜５５゜であることを特徴とする。
【００２３】
また請求項２記載の発明は、ロフト角が最小である最も低番手（ｉ＝１）のゴルフクラブから、ロフト角が最大である最も高番手（ｉ＝ｑ）のゴルフクラブまで３本以上の番手（ｉ＝１〜ｑ）のゴルフクラブをセットとしたアイアンゴルフクラブセットであって、
該アイアンゴルフクラブセットは、クラブヘッドのフェース面の摩擦係数が最も大きい高摩擦フェース面を有するゴルフクラブを１本又は番手を連続させて２本以上含むとともに、
この高摩擦フェース面のゴルフクラブのロフト角を２４°〜５５゜としかつ番手をｍ（高摩擦フェース面のゴルフクラブが複数かつ奇数本あるとき、その中間の番手の番号をｍとおく。また、高摩擦フェース面のゴルフクラブが偶数本あるとき、中間下の番手の番号をｍ１、中間上の番手の番号をｍ２とし、高摩擦フェース面のゴルフクラブのクラブヘッドにおける各種の値を特定するときは、この２本の平均値を用いることとし、便宜的に符号ｍを付して示す）とするとき、
前記高摩擦フェース面のゴルフクラブの番手ｍ（又はｍ１、ｍ２）が、式（１）を満たし、かつｉ番目（ｉ＝１〜ｑ）のクラブヘッドのフェース面の摩擦係数をμｉとするとき式（２）の要件を満たし、

しかも前記アイアンゴルフクラブセットは、クラブヘッドのフェース面に複数本の溝を具えるゴルフクラブからなり、前記溝が以下の４つの条件ａ１、ａ２、ａ３、ａ４の条件を満たすとともに、
前記高摩擦フェース面のゴルフクラブにおいて、前記溝の溝深さＤを０．４〜０．５ mm 、溝幅Ｗを０．７〜０．９ mm 、溝４の間隔Ｋを２．１〜３．５ mm 、溝壁角度θを９０〜１２０度、
最も高番手および低番手のゴルフクラブのフェース面の溝は、高摩擦フェース 面のゴルフクラブに形成した前記溝４を基準とすると、溝深さ、溝幅Ｗがともに８０％以下、溝壁角度θ、溝の間隔Ｋがともに１２０％以上としたことを特徴とするアイアンゴルフクラブセットである。
ａ１）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドの溝深さをＤｉとするとき
Ｄ１＜Ｄｍ かつ
Ｄｍ＞Ｄｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｄｉ≦Ｄ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｄｉ≧Ｄ（ｉ＋１）
ａ２）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドの溝幅をＷｉとするとき
Ｗ１＜Ｗｍ かつ
Ｗｍ＞Ｗｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｗｉ≦Ｗ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｗｉ≧Ｗ（ｉ＋１）
ａ３）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドの溝と溝との間の間隔をＫｉとするとき
Ｋ１＞Ｋｍ かつ
Ｋｍ＜Ｋｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｋｉ≧Ｋ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｋｉ≦Ｋ（ｉ＋１）
ａ４）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドのフエース面と溝の溝壁とが挟む角度をθｉとするとき
θ１＞θｍ かつ
θｍ＜θｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では θｉ≧θ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では θｉ≦θ（ｉ＋１）
【００２４】
また請求項記載の発明は、ロフト角が最小である最も低番手（ｉ＝１）のゴルフクラブから、ロフト角が最大である最も高番手（ｉ＝ｑ）のゴルフクラブまで３本以上の番手（ｉ＝１〜ｑ）のゴルフクラブをセットとしたアイアンゴルフクラブセットであって、
該アイアンゴルフクラブセットは、クラブヘッドのフェース面の摩擦係数が最も大きい高摩擦フェース面を有するゴルフクラブを１本又は番手を連続させて２本以上含むとともに、
この高摩擦フェース面のゴルフクラブのロフト角を２４°〜５５゜としかつ番手をｍ（高摩擦フェース面のゴルフクラブが複数かつ奇数本あるとき、その中間の番手の番号をｍとおく。また、高摩擦フェース面のゴルフクラブが偶数本あるとき、中間下の番手の番号をｍ１、中間上の番手の番号をｍ２とし、高摩擦フェース面のゴルフクラブのクラブヘッドにおける各種の値を特定するときは、この２本の平均値を用いることとし、便宜的に符号ｍを付して示す）とするとき、
前記高摩擦フェース面のゴルフクラブの番手ｍ（又はｍ１、ｍ２）が、式（１）を満たし、かつｉ番目（ｉ＝１〜ｑ）のクラブヘッドのフェース面の摩擦係数をμｉとするとき式（２）の要件を満たすとともに、

前記アイアンゴルフクラブセットは、クラブヘッドのフェース面に複数個のパンチマークを具えるゴルフクラブからなり、
しかも前記パンチマークが以下の３つの条件ｂ１、ｂ２、ｂ３の条件を満たすとともに、
しかも高摩擦フェース面のゴルフクラブにおいて、フェース面３に設けられるパンチマーク５の深さｄを０．５〜１．０ mm 、パンチマークの面積Ｓを、２．０〜２．８ mm ² 、隣り合うパンチマークの間隔ｋを、４．３〜６．０ mm とするとと もに、
最も高番手および低番手のゴルフクラブに形成されるパンチマークは、前記高摩擦フェース面のゴルフクラブに形成したパンチマークを基準とすると、その深さｄ、面積Ｓがともに８０％以下、パンチマークの間隔Ｋを１２０％以上としたことを特徴とするアイアンゴルフクラブセットである。
ｂ１）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドのパンチマークの深さをｄｉとするとき
ｄ１＜ｄｍ かつ
ｄｍ＞ｄｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では ｄｉ≦ｄ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では ｄｉ≧ｄ（ｉ＋１）
ｂ２）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドのパンチマークの面積Ｓｉとするとき
Ｓ１＜Ｓｍ かつ
Ｓｍ＞Ｓｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｓｉ≦Ｓ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｓｉ≧Ｓ（ｉ＋１）
ｂ３）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドの隣り合うパンチマークの間隔をｋｉとするとき
ｋ１＞ｋｍ かつ
ｋｍ＜ｋｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では ｋｉ≧ｋ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では ｋｉ≦ｋ（ｉ＋１）
【００２５】
ロフト角が最小である最も低番手（ｉ＝１）のゴルフクラブから、ロフト角が最大である最も高番手（ｉ＝ｑ）のゴルフクラブまで３本以上の番手（ｉ＝１〜ｑ）のゴルフクラブをセットとしたアイアンゴルフクラブセットであって、
該アイアンゴルフクラブセットは、クラブヘッドのフェース面の摩擦係数が最も大きい高摩擦フェース面を有するゴルフクラブを１本又は番手を連続させて２本以上含むとともに、
この高摩擦フェース面のゴルフクラブのロフト角を２４°〜５５゜としかつ番手をｍ（高摩擦フェース面のゴルフクラブが複数かつ奇数本あるとき、その中間の番手の番号をｍとおく。また、高摩擦フェース面のゴルフクラブが偶数本あるとき、中間下の番手の番号をｍ１、中間上の番手の番号をｍ２とし、高摩擦フェース面のゴルフクラブのクラブヘッドにおける各種の値を特定するときは、この２本の平均値を用いることとし、便宜的に符号ｍを付して示す）とするとき、
前記高摩擦フェース面のゴルフクラブの番手ｍ（又はｍ１、ｍ２）が、式（１）を満たし、かつｉ番目（ｉ＝１〜ｑ）のクラブヘッドのフェース面の摩擦係数をμｉとするとき式（２）の要件を満たし、

【００２６】
しかも請求項４に係る発明は、前記アイアンゴルフクラブセットの各ゴルフクラブは、クラブヘッドのフェース面の十点平均粗さＲが以下の条件ｃ１を充足するとともに、
高摩擦フェース面のゴルフクラブのフェース面の十点平均粗さを２０μｍ以上、低番手、高番手のゴルフクラブのフェース面の十点平均粗さを１０μｍ以下としたことを特徴とするアイアンゴルフクラブセットである。
ｃ１）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドのフェース面の十点平均粗さをＲｉとするとき
Ｒ１＜Ｒｍ かつ
Ｒｍ＞Ｒｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｒｉ≦Ｒ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｒｉ≧Ｒ（ｉ＋１）
【００２７】
本明細書において、クラブヘッドのロフト角は、ライ角を規格値にあわせ、シャフト（ヘッドセットの場合にはホーゼル）を地面に対して垂直に固定し、プロトラクタなどの角度計で地面とフェース面との角度βを測定し、該角度β（図１に示す）から９０゜を引くことにより求めるいわゆるリアルロフト角として求める。
【００２８】
またフェース面の摩擦係数は、図１５に示すように、基台ａに対して滑らかに走行可能な移動台ｂに、市販の１ピースゴルフボールｃを固定するとともに、このボールｃに縦荷重４００ｋｇｆでフェース面と同じ材質かつ同じ表面状態にした被測定板ｄを配した押圧部ｆを押し当て、前記移動台に５０（mm／分）の横変位を与えてボールと被測定物とを滑らせるとともに、前記縦荷重とロードセルｇより測定される横荷重との関係より静止摩擦係数μを求めるものとする。なお本例では「３０ｔアムスラー試験機」を使用して測定した。
【００２９】
またフェース面の溝幅は、Ｒ＆Ａの内規「３０度測定法」に基づき測定するものとし、クラブヘッドのフェース面に溝が設けられていない場合には、溝幅、溝深さはともに０、溝の間隔は無限大、溝壁角度は１８０度とする。同様にフェース面にパンチマークが設けられていないクラブヘッドの場合には、パンチマークの深さ、面積はともに０とし、パンチマークの間隔は無限大とする。
【００３０】
さらにフェース面の十点平均粗さは、ＪＩＳ Ｂ０６０１の第５項の「十点平均粗さ（Ｒｚ）の定義及び表示」に従って測定するものとし、本例では表面形状解析装置ＳＡＳ−２０１０（東京精密社製）を使用して測定した。
【００３１】
【発明の実施の形態】
以下、本発明の実施の一形態をアイアンゴルフクラブセットを例にとり図面に基づき説明する。図１に示すように、本実施形態のアイアンゴルフクラブセット１は、ロフト角αが最小であり最も低番手（ｉ＝１）のゴルフヘッド２ａから、ロフト角αが最大である最も高番手（ｉ＝ｑ）のクラブヘッドまで３本以上の番手（ｉ＝１〜ｑ）をセットとしたものを例示している。なお、シャフトＳが未だ装着されていないヘッドＨの単体からなるアイアンクラブヘッドセットであってもかまわない。
【００３２】
このようなアイアンゴルフクラブセット１は、例えば番手数が奇数又は偶数のみからなるハーフセットや、３番アイアン〜９番アイアンまでの７本セット（ｉ＝１〜７）、 さらには、これらにドライビングアイアン、２番アイアン、ピッチングウエッジ、アプローチウエッジ、サンドウエッジ、ロブウエッジなどの１ないし複数本を加えたセットとすることができる。そして、セットの総本数は少なくとも３本以上、好ましくは５本以上、より好ましくは７本以上であってさらに好ましくは７〜１０本で構成されうる。
【００３３】
図１に示す実施形態では、３番アイアン、５番アイアン、７番アイアン、９番アイアン、１１番アイアン（サンドウエッジ）のゴルフクラブ２ａ〜２ｅからなるセットの総本数が５本（ｉ＝１〜５）のものを例示している。なお前記符号「ｉ」は、各ゴルフクラブ２の番手を特定するために低番手のゴルフクラブ２から順に付される自然数の番号であって、実際のクラブの番手数（例えば５番アイアンの「５」など）を表示するものとは異なる。また図の下方に各ロフト角αを表示している。
【００３４】
またアイアンゴルフクラブセット１においては、例えば最もロフト角が小さいもので１０〜２５度、最もロフト角が大きいもので５６〜６０度程度とするのが好ましい。またクラブヘッドＨ（以下、単にヘッドＨということがる。）は、ステンレス、チタン、チタン合金、あるいはこれらの２種以上を組み合わせた複合材料など種々の材料で構成でき、本例ではステンレス材からなるヘッド本体に、フェース面３として純チタンからなるフェースプレートを装着したものを例示している。なおシャフトＳは慣例に従い例えばロフト角の増大に伴って徐々に短くしうる。
【００３５】
またアイアンゴルフクラブセットは、クラブヘッドＨのフェース面３の摩擦係数が最も大きい高摩擦フェース面を具えるゴルフクラブを１本又は番手を連続させて２本以上含んでる。したがって、前記高摩擦フェース面のゴルフクラブが、複数本であっても、例えば番手の番号で１、３、５の如く非連続に含まれるゴルフクラブセットは本発明の対象外となる。
【００３６】
さらに本実施形態では、この高摩擦フェース面のゴルフクラブの番手をｍとおくが、高摩擦フェース面のゴルフクラブが複数かつ奇数本あるとき、その中間の番手の番号をｍとし、また高摩擦フェース面のゴルフクラブが偶数本あるとき、中間下の番手の番号をｍ１、中間上の番手の番号をｍ２とし、高摩擦フェース面のゴルフクラブのクラブヘッドにおける各種の値（例えばフェース面に設けられた溝の寸法など）を特定するときは、この２本の平均値を用いることとし、便宜的に符号ｍを付して示す。
【００３７】
また本発明のゴルフクラブヘッドセット１は、前記高摩擦フェース面のゴルフクラブの番手ｍ（又はｍ１、ｍ２）が、
１＜ｍ（又はｍ１、ｍ２）＜ｑ
の条件を満たす。つまり、高摩擦フェース面のゴルフクラブの番手ｍ（又はｍ１、ｍ２）は、１より大きくかつｑ（本例では５）よりも小さいものとして設定される。
【００３８】
また本発明では、各ゴルフクラブ２のヘッドＨのフェース面３の摩擦係数が以下の条件を満たすことを特徴の一つとしている。
ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨのフェース面３の摩擦係数をμｉとするとき
μ１＜μｍ かつ
μｍ＞μｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では μｉ≦μ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では μｉ≧μ（ｉ＋１）
【００３９】
このように、アイアンゴルフクラブセット１の各ゴルフクラブ２のフェース面３の摩擦係数を設定することにより、最も低番手および最も高番手のゴルフクラブの２本を除いた番手の中に最もフェース面３の摩擦係数が大きいゴルフクラブが存在し、かつ低番手及び高番手のゴルフクラブでは、これよりもフェース面３の摩擦係数が相対的に小さく設定され、また好ましくは低番手および高番手に向かうにつれてフェース面の摩擦係数が小さくなるよう設定されうる。
【００４０】
したがって、低番手のゴルフクラブ２ａでは、前記新たな知見に基づき、ボールのバックスピン量を増加させて揚力を補うことにより、打ち出し角度が低い初級者ゴルファにとってキャリー増大効果が得られ、ひいては飛距離を向上しうる。また高番手のゴルフクラブ２ｅではフェース面の低摩擦によりボールのバックスピン量が抑制されるため、吹け上がりを防いで同様にキャリーを増し飛距離を向上しうる。
【００４１】
さらに、フェース面の摩擦係数が最も大きく設定された高摩擦フェース面のゴルフクラブは、例えばそのゴルフクラブのロフト角が２４〜５５゜、より好ましくは２４〜５０゜、さらに好ましくは２６〜５０゜、さらに好ましくは２６〜４８゜であるのが好ましい。このような場合、初級者でも比較的ボールの打ち出し角度を比較的大きくしうるいわゆるミドルアイアンが高摩擦フェース面を具える傾向が強く、前記新規な知見に基づきバックスピン量が抑制されることとなるため吹け上がりが防止できキャリーの増大効果を期待しうる。
【００４２】
このように、本実施形態では、初級者ゴルファを対象として、アイアンゴルフクラブセットの全番手を通してキャリーを増大させ、飛距離性能を向上させることが可能になる。
【００４３】
図２には、この実施形態の一例を示し、（Ａ）、（Ｂ）は縦軸にフェース面の摩擦係数μ（上側が大）を、横軸には前記クラブセットの番手の番号ｉをとったグラフを示している。図２（Ａ）の曲線Ｌ３では、番手２、３、４が高摩擦フェース面のゴルフクラブとなるが、各種の比較を行う高摩擦フェース面のゴルフクラブの番手の番号ｍは、それらの中間をなす「３」となる。このセットでは、クラブセット内でフェース面の摩擦係数が２種類設定されたものを示している。
【００４４】
また図２（Ａ）の曲線Ｌ４では、セットの中間に位置する番手３が高摩擦フェース面のゴルフクラブとなる。このセットでは、クラブセット内でフェース面の摩擦係数が３種類で連続的に変化するものを示しており、高番手および低番手に向かうにつれてフェース面の摩擦係数が徐々に小さくなっている。すなわち、このアイアンゴルフクラブセットは、下記の好ましい関係を満たしている。
μ１＜μｍ かつ
μｍ＞μｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では μｉ＜μ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では μｉ＞μ（ｉ＋１）
【００４５】
また図２（Ｂ）の曲線Ｌ５、Ｌ６では、高摩擦フェース面のゴルフクラブの番手が「４」又は「２」となっている。このように、高摩擦フェース面のゴルフクラブの番手がゴルフクラブセットの中間に位置しなくても良い。特に曲線Ｌ５の如く、フェース面の摩擦係数をコントロールした場合には、例えば初級者の中でも特にボールの打ち出し角度が小さいレベルのゴルファのキャリー増大に好適である。逆に曲線Ｌ６の如く、フェース面の摩擦係数をコントロールした場合には、例えば初級者の中でもボールの打ち出し角度が大きいレベルのゴルファのキャリー増大に好適である。
【００４６】
なお、セット内で最大となるフェース面の摩擦係数は、例えば０．３５以上とする。より好ましくは０．４０以上、さらに好ましくは０．４５以上とするのが特に好ましい。
【００４７】
このようにフェース面３の摩擦係数を変化させる方法としては、例えばフェース面３に形成される溝、パンチマーク、表面粗さ、メッキ処理などに変化を与えることなどが挙げられ、以下順に説明する。
【００４８】
（第１実施形態）
この例では、図３に示すように、フェース面３に複数本の溝４を具える１以上のゴルフクラブ２を具え、本例では全てのゴルフクラブのヘッドＨに溝４を設けたものを例示している。このような溝４の断面を拡大して図４に示すが、溝４の深さＤを大きくするほど、また溝幅Ｗを大きくするほど、さらには溝と溝との間の間隔（同じ側の溝壁縁間の距離）を小さくするほど、またフェース面３と溝４の溝壁４ａとが挟む角度θを小さくするほど、フェース面３の摩擦係数を大きくしうる。
【００４９】
したがって、クラブセット１において上述のように摩擦係数μを変化させるためには、前記溝４が以下の４つの条件ａ１、ａ２、ａ３、ａ４の条件を満たすことが好ましい。なお高摩擦フェース面のゴルフクラブの番手の番号ｍなどは前記した通りである。
【００５０】
ａ１）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨの溝深さをＤｉとするとき
Ｄ１＜Ｄｍ かつ
Ｄｍ＞Ｄｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｄｉ≦Ｄ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｄｉ≧Ｄ（ｉ＋１）
ａ２）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨの溝幅をＷｉとするとき
Ｗ１＜Ｗｍ かつ
Ｗｍ＞Ｗｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｗｉ≦Ｗ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｗｉ≧Ｗ（ｉ＋１）
ａ３）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨの溝と溝との間の間隔をＫｉとするとき
Ｋ１＞Ｋｍ かつ
Ｋｍ＜Ｋｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｋｉ≧Ｋ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｋｉ≦Ｋ（ｉ＋１）
ａ４）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨのフエース面と溝の溝壁とが挟む角度をθｉとするとき
θ１＞θｍ かつ
θｍ＜θｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では θｉ≧θ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では θｉ≦θ（ｉ＋１）
【００５１】
そして、本実施形態のアイアンゴルフクラブセット１では、このような条件ａ１〜ａ４の少なくとも１つ、好ましくは２以上、より好ましくは３以上、さらに好ましくは全てを満たすことが最も望ましい。
【００５２】
なお高摩擦フェース面のゴルフクラブにおいて、例えば前記溝４の溝深さＤは０．４〜０．５mm、溝幅Ｗは０．７〜０．９mm、溝４の間隔Ｋを２．１〜３．５mm、溝壁角度θを９０〜１２０度とする。
【００５３】
前記溝深さＤが０．４mm未満、溝幅Ｗが０．７mm未満、溝の間隔Ｋが３．５mmよりも大、又は溝壁角度θが１２０度を超えるときなどでは、フェース面３の摩擦係数の増大効果が相対的に低下する傾向がある。逆に溝深さＤが０．５mmよりも大、溝幅Ｗが０．９mmよりも大、又は溝壁角度θが９０度未満のとき、ゴルフルールに適合しなくなり好ましくない。
【００５４】
なお、一般に雨天時などウェット状態でゴルフクラブを使用する際には打撃されたボールのバックスピン量が相対的に低下しやすいため、またセット中の全てのクラブに溝４があると購買者に安心感を与えるため、セット中の全てのクラブのフェース面３に溝４を設けるのが望ましい。
【００５５】
このような場合、最も高番手および低番手のゴルフクラブのフェース面３の溝４は、例えば高摩擦フェース面のゴルフクラブに形成した前記溝４を基準とすると、溝深さ、溝幅Ｗがともに８０％以下、溝壁角度θ、溝の間隔Ｋがともに１２０％以上とする。なおこれらの溝４は、ゴルフルールに従いクラブのフェース面および溝の長さの全体にわたって同じ断面形状に設定されかつ左右対称の溝壁４ａにて形成される。
【００５６】
またこの溝４に関して、溝深さＤについてのＤ１＞Ｄｑ、溝幅ＷについてのＷ１＞Ｗｑ、溝間間隔ＫについてのＫ１＞Ｋｑ、溝壁角度θについてのθ１＞θｑの少なくとも１つを充足することも好ましく、さらには不等号を逆とすることでも良い。
【００５７】
（第２実施形態）
次に、フェース面３の摩擦係数を変える手法として該フェース面３にパンチマーク５を設けたものについて説明する。パンチマーク５とは、図５に示すようにクラブヘッド２のフェース面３に設けられた円ないし楕円形状の小孔であり、このパンチマーク５の深さｄが大きいほど、また面積Ｓ（表面積）が大きいほど、また隣り合うパンチマーク５、５の間隔ｋが小さいほどフェース面３の摩擦係数を大きくすることができる。
【００５８】
そして前記アイアンゴルフクラブセットは、クラブヘッドのフェース面に複数個のパンチマーク５を具える１以上のゴルフクラブ２を具え、本例では全てのゴルフクラブのヘッドＨにパンチマーク５を具えたものを例示しており、このパンチマーク５が以下の３つの条件ｂ１、ｂ２、ｂ３の条件を満たすものを示している。
【００５９】
ｂ１）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨのパンチマークの深さをｄｉとするとき
ｄ１＜ｄｍ かつ
ｄｍ＞ｄｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では ｄｉ≦ｄ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では ｄｉ≧ｄ（ｉ＋１）
ｂ２）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨのパンチマークの面積Ｓｉとするとき
Ｓ１＜Ｓｍ かつ
Ｓｍ＞Ｓｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｓｉ≦Ｓ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｓｉ≧Ｓ（ｉ＋１）
ｂ３）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドＨの隣り合うパンチマークの間隔をｋｉとするとき
ｋ１＞ｋｍ かつ
ｋｍ＜ｋｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では ｋｉ≧ｋ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では ｋｉ≦ｋ（ｉ＋１）
【００６０】
このような実施例においては、前記条件ｂ１〜ｂ３の条件を満たすことが望ましい。
【００６１】
なお例えば高摩擦フェース面のゴルフクラブにおいて、例えばフェース面３に設けられるパンチマーク５の深さｄは０．５〜１．０mm、パンチマークの面積Ｓは、２．０〜２．８mm2 、隣り合うパンチマークの間隔ｋは、４．３〜６．０mmとする。
【００６２】
前記パンチマークの深さｄが０．５mm未満、パンチマークの面積Ｓが２．０mm² 未満、又は隣り合うパンチマークの間隔ｋは、６．０mmよりも大のときには、フェース面３の摩擦係数の増大効果が相対的に低下する傾向がある。逆にパンチマークの深さｄが１．０mmよりも大、パンチマークの間隔ｋが４．３mm未満であると、ゴルフルールに適合しなくなり好ましくない。
【００６３】
またセット中の全てのクラブにパンチマーク５を設ける場合、最も高番手および低番手のゴルフクラブに形成されるパンチマーク５は、例えば前記高摩擦フェース面のゴルフクラブに形成したパンチマーク５を基準とすると、その深さｄ、面積Ｓがともに８０％以下、パンチマークの間隔Ｋが１２０％以上とする。
【００６４】
（第３実施形態）
フェース面３の摩擦係数を変える他の手法として、図６に示すように、例えばサンドブラスト処理などにより微細な凹凸６をフェース面３に施すことが挙げられる。このようなフェース面３の摩擦係数は、表面粗さ、例えば十点平均粗さＲに比例する。そこで本例ではアイアンゴルフクラブセットの各ゴルフクラブは、クラブヘッドのフェース面の十点平均粗さＲが以下の条件ｃ１を満たす。
【００６５】
ｃ１）ｉ番目（ｉ＝１〜ｑ）のクラブヘッドのフェース面の十点平均粗さをＲｉとするとき
Ｒ１＜Ｒｍ かつ
Ｒｍ＞Ｒｑ かつ
ｉ＝１とｉ＝ｍ（又はｍ１）との間では Ｒｉ≦Ｒ（ｉ＋１） かつ
ｉ＝ｍ（又はｍ２）とｉ＝ｑとの間では Ｒｉ≧Ｒ（ｉ＋１）
【００６６】
なお高摩擦フェース面のゴルフクラブにおいて、フェース面３の十点平均粗さが例えば２０μｍ以上とする。より好ましくは３０μｍ以上、さらに好ましくは４０μｍ以上とするのが望ましい。また低番手、高番手のゴルフクラブでは、フェース面の十点平均粗さが１０μｍ以下とする。そして、このような粗さの変化は、例えばブラスト粒子の粒径を変化させることによって容易になしうる。
【００６７】
なお、上述した各条件、すなわち前記溝４、パンチマーク５、フェース面の十点平均粗さを適宜組み合わせて用いても良い。
【００６８】
以上好ましい実施形態について詳述したが、本発明は、例えばフェース面３のメッキ処理を施したものと、それを施さないものなどにより摩擦係数μを変えるようにしてもよく、種々の態様に変形しうる。
【００６９】
【実施例】
（第１実施例）
フェース面に溝を設けたゴルフクラブを含む総本数６本のアイアンゴルフクラブヘッドセットを表１の仕様にて試作し（実施例１、２、比較例１）、シャフトを装着してアイアンゴルフクラブセットとして製造するとともに、スイングロボットにより試打テストを行い、打ち出しされたボールのバックスピン量、打ち出し角度、キャリー、ラン、トータル飛距離をそれぞれ測定した。なおスイングロボットは、ロフト角１５度のクラブヘッドを有するクラブでヘッドスピード（３６．５ｍ／ｓ）になるよう設定した。クラブヘッドの仕様を表１に、テストの結果を表２に示す。
【００７０】
【表１】

【００７１】
【表２】

【００７２】
（第２実施例）
フェース面にパンチマークを設けたゴルフクラブを含む総本数６本のアイアンゴルフクラブセットを表３の仕様にて試作し（実施例３、比較例２）、前記の条件で試打テストを行った。クラブヘッドの仕様、テストの結果を表３に示す。
【００７３】
【表３】

【００７４】
（第３実施例）
フェース面にサンドプラスト処理を施すことによりその表面粗さを変えたクラブセットを表４の仕様にて試作し（実施例４、比較例３）、前記の条件で試打テストを行った。クラブヘッドの仕様及びテストの結果を表４に示す。
【００７５】
【表４】

【００７６】
テストの結果、実施例のアイアンゴルフクラブセットでは、最も低番手のゴルフクラブからロフト角３２゜までのゴルフクラブのフェース面の摩擦係数を小さくしたため、これらのクラブで打ち出しされたボールのバックスピン量が相対的に多くなっており、打ち出し角度が小さくてもキャリーが増大していることが確認できる。またロフト角が４０゜のゴルフクラブでは、フェース面の摩擦係数を大きく設定したことにより、バックスピン量が減少しており、打ち出し角度も十分に確保されていることと相まってキャリーが増大していることが確認できる。さらに最も高番手のゴルフクラブでは、フェース面の摩擦係数を小さくしたため、ボールのバックスピン量が相対的に少なく、吹け上がりが防止されてキャリーが増大していることが確認できる。
【００７７】
【発明の効果】
上述したように、請求項１〜６記載の発明では、初級者ゴルファなどにおいても、最も低番手のゴルフクラブでボールのバックスピンを増し、キャリーを増大する。また最も高番手のゴルフクラブでは、ボールのバックスピンを減じて吹け上がりを防ぎキャリーを増大しうる。さらにフェース面の摩擦係数が最も大きい高摩擦フェース面のゴルフクラブが、最も低番手および最も高番手を除いた番手に設定されるため、例えばミドルアイアンなどでボールのバックスピン量を減じることができ、キャリーの増大を可能としうる。
【００７８】
特に請求項２記載の発明では、高摩擦フェース面のゴルフクラブのロフト角を設定したことにより、全番手を通してより遠くにボールを飛ばすことが可能なアイアンゴルフクラブセット及びアイアンゴルフクラブヘッドセットを提供しうる。
【図面の簡単な説明】
【図１】本実施形態のアイアンゴルフクラブセットの一例を示す側面図である。
【図２】（Ａ）、（Ｂ）は、本実施形態のセットの各番手とフェース面の摩擦係数μとの関係を示すグラフである。
【図３】本実施形態のセットの中から一部のゴルフクラブを取り出して例示する正面図である。
【図４】フェース面の溝と直交するヘッドの断面図である。
【図５】本実施形態のセットの中から一部のゴルフクラブを取り出して例示する正面図である。
【図６】本実施形態のセットの中から一部のゴルフクラブを取り出して例示する正面図である。
【図７】従来のセットの各番手とフェース面の摩擦係数μとの関係を示すグラフである。
【図８】フェース面の表面状態とボールのバックスピン量との関係を示すグラフである。
【図９】３番アイアンのフェース面の表面状態とボールの打ち出し角度との関係を示すグラフである。
【図１０】５番アイアンのフェース面の表面状態とボールの打ち出し角度との関係を示すグラフである。
【図１１】７番アイアンのフェース面の表面状態とボールの打ち出し角度との関係を示すグラフである。
【図１２】ＳＷのフェース面の表面状態とボールの打ち出し角度との関係を示すグラフである。
【図１３】ボールとフェース面のインパクトの過程を説明する断面図である。
【図１４】インパクトからの経過時間とボールのカバーとコア部分との間のせん断力との関係を示すグラフである。
【図１５】フェース面の摩擦係数の測定方法を示す図である。
【符号の説明】
２ クラブヘッド
３ フェース面
４ 溝
５ パンチマーク
６ 凹凸
Ｓ シャフト
Ｈ クラブヘッド[0001]
BACKGROUND OF THE INVENTION
The present invention provides an iron golf club set in which the spin performance of a hit ball is improved according to each count so as to increase the flight distance of beginner golfers and the like through all counts by controlling the surface state of the face surface of the club head and The present invention relates to an iron golf club headset.
[0002]
[Prior art]
Women or beginner golfers generally have a slow club head speed, and a long iron with a small loft angle cannot provide a sufficient launch angle with respect to the hit ball. Therefore, in such a count, the hit ball falls immediately, and the flight distance is lost due to the so-called carry shortage. In order for golfers of the above levels to increase the flight distance with long irons, it is important to increase the backspin amount to the hit ball to some extent and compensate for the lift to the ball to increase carry. is there.
[0003]
On the other hand, even golfers of these technical levels can increase the launch angle of the ball to some extent according to the loft angle when the ball is hit with a short iron having a large loft angle. Therefore, in order to increase the flight distance of the ball with a short iron, it is important to reduce the backspin amount to prevent so-called blow-up.
[0004]
The backspin amount of such a ball greatly depends on the coefficient of friction of the face surface of the golf club with which the ball contacts at the time of impact. Conventionally, as an iron golf club set for controlling the backspin amount of a hit ball, for example, a special Japanese Laid-Open Patent Application No. 61-272067, Japanese Laid-Open Patent Application No. 2-228980, Japanese Laid-Open Patent Application No. 2-228811, Japanese Laid-Open Patent Application No. 9-192274 have been proposed.
[0005]
In these proposals, the depth, width, size, shape, arrangement interval, and surface roughness of the face surface according to the number of golf clubs, such as grooves and punch marks formed on the face surface of the club head. It is suggested to change. For example, in these proposals, as indicated by a curve L1 shown in FIG. 7, for example, a long iron with a smaller loft angle is set to have a smaller friction coefficient on the face surface, and conversely, a short iron with a larger loft angle has a smaller friction coefficient on the face surface. Is shown to be set large.
[0006]
When the friction coefficient of the face surface is controlled in this way, relatively long backspin is achieved with long irons and carry is increased for advanced players, etc., and the backspin amount is increased with short irons and the ball falls to the ground. It is explained that the control performance is improved by reducing the number of runs.
[0007]
In Japanese Patent Application Laid-Open No. 61-272067, as shown by a curve L2, the friction coefficient of the face surface is decreased as the short iron is suppressed to prevent the ball from being raised too high, and the back spin amount is increased with the long iron. It also discloses improving controllability.
[0008]
[Problems to be solved by the invention]
However, as a result of various experiments conducted by the present inventors, as for the high-count iron golf club, as the friction coefficient of the face surface was increased, the backspin amount of the hit ball certainly increased, but it was surprising. In particular, it has been found that in a low-count iron golf club, when the friction coefficient of the face surface is reduced, the backspin amount of the ball tends to increase slightly, contrary to the conventional expectation.
[0009]
FIG. 8 shows the relationship between the surface state of the face surface of the club head and the backspin amount of the hit ball among the experimental results. 9 to 12 show the relationship between the surface state of the face surface and the launch angle of the hit ball.
[0010]
In the experiment, 3 iron (loft angle 21 °), 5 iron (loft angle 29 °), 7 iron (loft angle 37 °), sand wedge (loft angle 56 °) from the iron golf club set. Using four clubs, the same ball (two-piece ball) was tested using a swing robot under the same conditions. The face surface of each iron is made of titanium but has no groove and has a smooth surface (the smallest friction coefficient), no groove and has a rough surface, and has a groove and a rough surface. Comparison was made in three stages of surface states of those having the highest (the coefficient of friction being the largest).
[0011]
As a result of these experiments, in the third, fifth and seventh irons having relatively small loft angles, the backspin amount of the hit ball is relatively smaller as the friction coefficient of the face surface is larger, contrary to the conventional prediction. In addition, a tendency for the launch angle to increase was confirmed.
[0012]
To fully elucidate such a phenomenon theoretically, further analysis of the complex deformation behavior of the ball at the time of impact is required, but one cause is the impact of the club head face surface and the ball. It can be presumed that the internal spin of the core part of the generated ball is influencing.
[0013]
13A to 13D show the impact state of the ball in time series. FIG. 14 is a graph showing the relationship between the shearing force between the core portion B1 (position P1) of the ball B and the cover B2 (position P2) and the elapsed time from the impact.
[0014]
As shown in FIG. 13A, the impacted ball B is deformed and comes into close contact with the face surface 3 in a relatively wide range. At this time, the ball B receives the frictional force M in the direction along the face surface 3 and the vertical force from the face surface 3 from the face surface 3. It was thought that the larger the M, the greater the backspin amount of the ball B.
[0015]
The inventors examined the process during the impact of the ball B in more detail. As a result, the cover B2 of the ball B has a position P1 inside the ball shown in FIG. 13 due to a shearing force that pulls the cover B2 in the frictional force direction. It was ascertained that the positions of P2 were relatively displaced in the circumferential direction (FIG. 13B).
[0016]
Such misalignment between the core portion B1 and the cover B2 tends to be restored as the deformation of the impacted ball B starts to be restored to the original state. Due to this restoring force, a shearing force in the direction opposite to the above acts between the core portion B1 and the cover B2, and the positions P1 and P2 are neutral positions where the positional deviation is eliminated (FIG. 13 (c)). It is launched from the face surface 3 at a position further beyond.
[0017]
At this time, it has been found that the internal spin in the forward direction, which is opposite to the back spin, remains in the core portion B1, and the back spin amount of the ball decreases as the internal spin increases. is there.
[0018]
Further, it has been found that the influence of such an internal spin appears remarkably in an iron golf club having a loft angle of, for example, 55 ° or less, particularly less than 50 °. Therefore, in such a golf club, when the coefficient of friction of the face surface is reduced, the internal spin rotating in the forward direction of the core portion B1 is decreased, so the backspin amount of the ball is rather increased.
[0019]
Therefore, in the case where the friction coefficient of the face surface is changed as shown by the curve L2, the backspin amount of the ball is actually reduced by a long iron or the like, and even a beginner golfer or the like causes a further carry shortage and the flying. There is a problem that the distance performance is significantly impaired.
[0020]
The present invention is based on improving the surface condition of the face surface of each iron club on the premise of the above new knowledge about the back spin amount and the friction coefficient of the face surface. An object is to provide an iron golf club set and an iron club headset that can be expected to increase the carry through all counts for beginners with small launches.
[0021]
[Means for Solving the Problems]
Of the present inventions, the invention according to claim 1 includes a golf club having a lowest loft angle (i = 1) to a golf club having the highest loft angle (i = q). An iron golf club set including a golf club having a count of more than 1 (i = 1 to q),
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The number of the high friction face surface golf club is m (when there are a plurality of odd number of high friction face surface golf clubs, the number of the intermediate number is m. Also, the high friction face surface golf club is an even number. When there is a book, the number of the lower middle number is m1, the number of the upper middle number is m2, and when specifying various values in the club head of the golf club of the high friction face surface, the average value of these two is used. And for convenience, it is indicated with the symbol m)
The golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1).And when the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi, the requirement of formula (2) is satisfied,
The friction coefficient of the high friction face surface is set to 0.35 or more.This is an iron golf club set.

[0022]
AlsoThe invention described in claim 1 further includesA golf club having a high friction face with the count number being m has a loft angle of 24 to 55 °.Do.
[0023]
AlsoClaim 2The described inventionThree or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
When the golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1) and the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi. Satisfy the requirement of equation (2)

  MoreoverThe iron golf club set includes a plurality of grooves on the face surface of the club head.Consisting of a golf clubThe groove has the following four conditions a1, a2, a3, a4ConditionsWhile satisfying
  In the golf club having the high friction face surface, the groove depth D of the groove is set to 0.4 to 0.5. mm , Groove width W is 0.7-0.9 mm , The distance K between the grooves 4 is 2.1 to 3.5. mm , The groove wall angle θ is 90 to 120 degrees,
The groove on the face of the highest and lowest golf clubs has a high friction face. The groove depth and groove width W are both 80% or less, the groove wall angle θ, and the groove interval K are both 120% or more, based on the groove 4 formed on the surface golf club.This is an iron golf club set.
a1) When the groove depth of the i-th (i = 1 to q) club head is Di
D1 <Dm and
Dm> Dq and
Between i = 1 and i = m (or m1), Di ≦ D (i + 1) and
Between i = m (or m2) and i = q, Di ≧ D (i + 1)
a2) When the groove width of the i-th (i = 1 to q) club head is Wi
W1 <Wm and
Wm> Wq and
Between i = 1 and i = m (or m1), Wi ≦ W (i + 1) and
Between i = m (or m2) and i = q, Wi ≧ W (i + 1)
a3) When the interval between the grooves of the i-th (i = 1 to q) club head is Ki
K1> Km and
Km <Kq and
Between i = 1 and i = m (or m1), Ki ≧ K (i + 1) and
Between i = m (or m2) and i = q, Ki ≦ K (i + 1)
a4) When the angle between the face surface of the i-th (i = 1 to q) club head and the groove wall is θi
θ1> θm and
θm <θq and
between i = 1 and i = m (or m1), θi ≧ θ (i + 1) and
Between i = m (or m2) and i = q, θi ≦ θ (i + 1)
[0024]
The invention described in the claimsThree or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
When the golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1) and the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi. While satisfying the requirement of formula (2),

The iron golf club set has a plurality of punch marks on the face surface of the club head.Consisting of a golf club,
  MoreoverThe punch mark satisfies the following three conditions b1, b2, and b3.With
  Moreover, in a golf club having a high friction face surface, the depth d of the punch mark 5 provided on the face surface 3 is set to 0.5 to 1.0. mm The area S of the punch mark is set to 2.0 to 2.8. mm ² , The interval k between adjacent punch marks is 4.3 to 6.0. mm And Also,
The punch marks formed on the highest and lowest count golf clubs have a depth d and an area S of 80% or less, based on the punch marks formed on the golf club having the high friction face. The interval K is set to 120% or more.This is an iron golf club set.
b1) When the punch mark depth of the i-th (i = 1 to q) club head is di
d1 <dm and
dm> dq and
between i = 1 and i = m (or m1), di ≦ d (i + 1) and
Between i = m (or m2) and i = q, di ≧ d (i + 1)
b2) When the area of the punch mark of the i-th (i = 1 to q) club head is Si
S1 <Sm and
Sm> Sq and
Between i = 1 and i = m (or m1), Si ≦ S (i + 1) and
Between i = m (or m2) and i = q, Si ≧ S (i + 1)
b3) When the interval between adjacent punch marks of the i-th (i = 1 to q) club head is ki
k1> km and
km <kq and
between i = 1 and i = m (or m1), ki ≧ k (i + 1) and
Between i = m (or m2) and i = q, ki ≦ k (i + 1)
[0025]
  Three or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
When the golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1) and the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi. Satisfy the requirement of equation (2)

[0026]
  In addition, in the invention according to claim 4, in each golf club of the iron golf club set, the ten-point average roughness R of the face surface of the club head satisfies the following condition c1,
An iron golf club characterized in that a ten-point average roughness of a face surface of a golf club having a high friction face is 20 μm or more, and a ten-point average roughness of a face surface of a golf club having a low count and a high count is 10 μm or less. Is a set.
c1) When the ten-point average roughness of the face surface of the i-th (i = 1 to q) club head is Ri
                              R1 <Rm And
                              Rm> Rq And
    Between i = 1 and i = m (or m1) Ri ≦ R (i + 1) And
    Between i = m (or m2) and i = q Ri≧ R (i + 1)
[0027]
In this specification, the loft angle of the club head is set so that the lie angle matches the standard value, the shaft (hosel in the case of a headset) is fixed perpendicular to the ground, and the ground and face are measured with an angle meter such as a protractor. The angle β with respect to the surface is measured, and a so-called real loft angle is obtained by subtracting 90 ° from the angle β (shown in FIG. 1).
[0028]
Further, as shown in FIG. 15, the friction coefficient of the face surface is such that a commercially available one-piece golf ball c is fixed to a moving table b that can run smoothly with respect to the base a, and a longitudinal load of 400 kgf is applied to the ball c. Then, a pressing portion f provided with a plate d to be measured having the same material and the same surface state as the face surface is pressed, and a lateral displacement of 50 (mm / min) is applied to the moving table to slide the ball and the object to be measured. In addition, the static friction coefficient μ is obtained from the relationship between the longitudinal load and the lateral load measured from the load cell g. In this example, measurement was performed using a “30 t Amsler tester”.
[0029]
Further, the groove width of the face surface is measured based on the internal rule “30 degree measurement method” of R & A. When no groove is provided on the face surface of the club head, the groove width and the groove depth are both 0, The interval between the grooves is infinite, and the groove wall angle is 180 degrees. Similarly, in the case of a club head in which punch marks are not provided on the face surface, the depth and area of the punch marks are both 0, and the interval between punch marks is infinite.
[0030]
Further, the ten-point average roughness of the face surface is measured in accordance with “Definition and display of ten-point average roughness (Rz)” in Section 5 of JIS B0601, and in this example, the surface shape analyzer SAS-2010 (Tokyo) Measured using a precision company.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking an iron golf club set as an example. As shown in FIG. 1, the iron golf club set 1 of the present embodiment has the lowest loft angle α and the lowest golf ball 2a (i = 1) to the highest golf ball 2a having the largest loft angle α (i = 1). A set of three or more counts (i = 1 to q) is illustrated up to the club head of i = q). It should be noted that an iron club headset including a single head H to which the shaft S is not yet mounted may be used.
[0032]
Such an iron golf club set 1 is, for example, a half set consisting of only an odd number or an even number of numbers, a set of 7 pieces from 3 iron to 9 iron (i = 1 to 7), and further to these A set including one or a plurality of irons, 2 irons, pitching wedges, approach wedges, sand wedges, lobe wedges, and the like can be used. And the total number of sets is at least 3 or more, preferably 5 or more, more preferably 7 or more, and still more preferably 7 to 10 pieces.
[0033]
In the embodiment shown in FIG. 1, the total number of golf clubs 2a to 2e of 3 iron, 5 iron, 7 iron, 9 iron, 11 iron (sand wedge) is 5 (i = 1). To 5). The symbol “i” is a natural number assigned in order from the lowest golf club 2 in order to identify the number of each golf club 2, and is the actual club number (for example, “5” 5 ”etc.). Each loft angle α is displayed at the bottom of the figure.
[0034]
Further, in the iron golf club set 1, for example, the smallest loft angle is preferably 10 to 25 degrees, and the largest loft angle is preferably about 56 to 60 degrees. The club head H (hereinafter simply referred to as the head H) can be made of various materials such as stainless steel, titanium, a titanium alloy, or a composite material combining two or more of these materials. In this example, a face plate made of pure titanium is mounted as the face surface 3 on the head body. It should be noted that the shaft S can be gradually shortened as the loft angle increases, for example, in accordance with conventional practice.
[0035]
Further, the iron golf club set includes one or more golf clubs having a high friction face surface having the largest friction coefficient of the face surface 3 of the club head H or two consecutive golf clubs. Therefore, even if there are a plurality of golf clubs having a high friction face, golf club sets that are discontinuously included, for example, 1, 3, and 5 by the number of the count, are out of the scope of the present invention.
[0036]
Further, in this embodiment, the golf club number of the high friction face surface is set to m. However, when there are a plurality of odd numbers of golf clubs of the high friction face surface, the number of the intermediate number is set to m, and the high friction surface number is high. When there are an even number of golf clubs on the face surface, the number of the lower middle number is m1 and the number of the upper middle number is m2. When specifying the dimension of the groove formed, etc., the average value of these two values is used, and is indicated with a symbol m for convenience.
[0037]
In the golf club headset 1 of the present invention, the golf club number m (or m1, m2) of the high friction face surface is
1 <m (or m1, m2) <q
Satisfy the condition of That is, the count m (or m1, m2) of the golf club having a high friction face is set to be larger than 1 and smaller than q (5 in this example).
[0038]
Further, the present invention is characterized in that the friction coefficient of the face surface 3 of the head H of each golf club 2 satisfies the following conditions.
When the friction coefficient of the face surface 3 of the i-th (i = 1 to q) club head H is μi
μ1 <μm and
μm> μq and
μi ≦ μ (i + 1) between i = 1 and i = m (or m1) and
Between i = m (or m2) and i = q, μi ≧ μ (i + 1)
[0039]
In this way, by setting the friction coefficient of the face surface 3 of each golf club 2 of the iron golf club set 1, the face surface is the most among the counts excluding the lowest and highest count golf clubs. In the case of golf clubs having a large friction coefficient of 3 and low and high count golf clubs, the friction coefficient of the face surface 3 is set to be relatively smaller than this, and preferably toward the low and high counts. Accordingly, the friction coefficient of the face surface can be set to be smaller.
[0040]
Therefore, in the low-count golf club 2a, by increasing the backspin amount of the ball and supplementing the lift force based on the new knowledge, a carry increasing effect can be obtained for a beginner golfer with a low launch angle, and thus a flight distance. Can be improved. Further, in the high-count golf club 2e, the backspin amount of the ball is suppressed by the low friction of the face surface, so that it is possible to prevent carry-up and increase the carry in the same manner, thereby improving the flight distance.
[0041]
Further, a golf club having a high friction face with the largest friction coefficient of the face surface has a loft angle of, for example, 24 to 55 °, more preferably 24 to 50 °, still more preferably 26 to 50 °. More preferably, the angle is 26 to 48 °. In such a case, even a beginner may tend to have a high friction face surface, so that the so-called middle iron that can make the ball launch angle relatively large, and the backspin amount is suppressed based on the new knowledge. Therefore, it is possible to prevent a blow-up and an increase in carry can be expected.
[0042]
Thus, in this embodiment, for beginner golfers, it is possible to increase the carry through all the iron counts of the iron golf club set and improve the flight distance performance.
[0043]
FIG. 2 shows an example of this embodiment. In FIGS. 2A and 2B, the vertical axis indicates the friction coefficient μ of the face surface (the upper side is large), and the horizontal axis indicates the number i of the club set. The graph is shown. In the curve L3 in FIG. 2A, the counts 2, 3, and 4 are golf clubs having a high friction face surface. The number m of the golf club having a high friction face surface to be subjected to various comparisons is an intermediate number between them. It becomes "3" which makes. In this set, two types of friction coefficients of the face surface are set in the club set.
[0044]
In the curve L4 in FIG. 2A, the count 3 located in the middle of the set is a golf club having a high friction face. In this set, the friction coefficient of the face surface is continuously changed in three types in the club set, and the friction coefficient of the face surface gradually decreases toward the higher and lower counts. That is, this iron golf club set satisfies the following preferable relationship.
μ1 <μm and
μm> μq and
μi <μ (i + 1) between i = 1 and i = m (or m1) and
Between i = m (or m2) and i = q, μi> μ (i + 1)
[0045]
Further, in the curves L5 and L6 in FIG. 2B, the golf club number of the high friction face surface is “4” or “2”. In this way, the golf club count of the high friction face surface does not have to be located in the middle of the golf club set. In particular, when the coefficient of friction of the face surface is controlled as shown by the curve L5, it is suitable for increasing the carry of a golfer having a small ball launch angle, for example, even among beginners. Conversely, when the coefficient of friction of the face surface is controlled as indicated by the curve L6, it is suitable for increasing the carry of a golfer having a large ball launch angle, for example, even among beginners.
[0046]
Note that the maximum friction coefficient of the face surface in the set is, for example, 0.35 or more.To. More preferably, it is 0.40 or more, and further preferably 0.45 or more.
[0047]
As a method of changing the friction coefficient of the face surface 3 in this way, for example, changing the groove, punch mark, surface roughness, plating treatment, etc. formed on the face surface 3 can be cited, and will be described in the following order. .
[0048]
(First embodiment)
In this example, as shown in FIG. 3, one or more golf clubs 2 having a plurality of grooves 4 are provided on the face surface 3, and in this example, the heads H of all the golf clubs are provided with the grooves 4. Illustrated. The cross section of the groove 4 is enlarged and shown in FIG. 4. As the depth D of the groove 4 is increased and the groove width W is increased, the distance between the grooves (same side) is increased. The distance between the groove wall edges)smallThe friction coefficient of the face surface 3 can be increased as the angle θ between the face surface 3 and the groove wall 4a of the groove 4 is decreased.
[0049]
Therefore, in order to change the friction coefficient μ in the club set 1 as described above, the groove 4 has the following four conditions a1, a2, a3,Condition of a4It is preferable to satisfy. The number m of the golf club with the high friction face surface is as described above.
[0050]
a1) When the groove depth of the i-th (i = 1 to q) club head H is Di
D1 <Dm and
Dm> Dq and
Between i = 1 and i = m (or m1), Di ≦ D (i + 1) and
Between i = m (or m2) and i = q, Di ≧ D (i + 1)
a2) When the groove width of the i-th (i = 1 to q) club head H is Wi
W1 <Wm and
Wm> Wq and
Between i = 1 and i = m (or m1), Wi ≦ W (i + 1) and
Between i = m (or m2) and i = q, Wi ≧ W (i + 1)
a3) When the interval between the grooves of the i-th (i = 1 to q) club head H is Ki
K1> Km and
Km <Kq and
Between i = 1 and i = m (or m1), Ki ≧ K (i + 1) and
Between i = m (or m2) and i = q, Ki ≦ K (i + 1)
a4) When the angle between the face surface of the i-th (i = 1 to q) club head H and the groove wall is θi
θ1> θm and
θm <θq and
between i = 1 and i = m (or m1), θi ≧ θ (i + 1) and
Between i = m (or m2) and i = q, θi ≦ θ (i + 1)
[0051]
In the iron golf club set 1 of the present embodiment, it is most desirable to satisfy at least one of these conditions a1 to a4, preferably 2 or more, more preferably 3 or more, and still more preferably all.
[0052]
In the golf club having a high friction face, for example, the groove depth D of the groove 4 is 0.4 to 0.5 mm, the groove width W is 0.7 to 0.9 mm, and the interval K of the grooves 4 is 2.1 to 3.5 mm, groove wall angle θ is 90-120 degreesTo do.
[0053]
When the groove depth D is less than 0.4 mm, the groove width W is less than 0.7 mm, the groove interval K is greater than 3.5 mm, or the groove wall angle θ exceeds 120 degrees, the face surface 3 The effect of increasing the friction coefficient tends to be relatively reduced. Conversely, when the groove depth D is greater than 0.5 mm, the groove width W is greater than 0.9 mm, or the groove wall angle θ is less than 90 degrees, it is not preferable because it does not conform to the golf rules.
[0054]
In general, when a golf club is used in a wet condition such as rainy weather, the backspin amount of the hit ball is relatively easy to decrease. In order to give a sense of security, it is desirable to provide grooves 4 on the face surfaces 3 of all clubs in the set.
[0055]
In such a case, the groove 4 on the face surface 3 of the golf club having the highest and lowest golf clubs has, for example, a groove depth and a groove width W based on the groove 4 formed on the golf club having the high friction face. Both are 80% or less, groove wall angle θ and groove interval K are both 120% or more.To do.These grooves 4 are formed in a symmetrical groove wall 4a which is set to have the same cross-sectional shape over the entire face surface of the club and the length of the groove in accordance with the golf rules.
[0056]
The groove 4 satisfies at least one of D1> Dq with respect to the groove depth D, W1> Wq with respect to the groove width W, K1> Kq with respect to the groove interval K, and θ1> θq with respect to the groove wall angle θ. It is also preferable that the inequality sign be reversed.
[0057]
(Second Embodiment)
Next, as a method for changing the friction coefficient of the face surface 3, a case where the punch mark 5 is provided on the face surface 3 will be described. The punch mark 5 is a circular or elliptical small hole provided in the face surface 3 of the club head 2 as shown in FIG. 5. As the depth d of the punch mark 5 increases, the area S (surface area) increases. ) Is larger, and the friction coefficient of the face surface 3 can be increased as the distance k between the adjacent punch marks 5 and 5 is smaller.
[0058]
The iron golf club set includes one or more golf clubs 2 each including a plurality of punch marks 5 on the face surface of the club head. In this example, all golf club heads H include the punch marks 5. This punch mark 5 has the following three conditions b1, b2, b3ConditionShows what meets.
[0059]
b1) When the punch mark depth of the i-th (i = 1 to q) club head H is di
d1 <dm and
dm> dq and
between i = 1 and i = m (or m1), di ≦ d (i + 1) and
Between i = m (or m2) and i = q, di ≧ d (i + 1)
b2) When the area is Si of the punch mark of the i-th (i = 1 to q) club head H
S1 <Sm and
Sm> Sq and
Between i = 1 and i = m (or m1), Si ≦ S (i + 1) and
Between i = m (or m2) and i = q, Si ≧ S (i + 1)
b3) When the interval between adjacent punch marks of the i-th (i = 1 to q) club head H is ki
k1> km and
km <kq and
between i = 1 and i = m (or m1), ki ≧ k (i + 1) and
Between i = m (or m2) and i = q, ki ≦ k (i + 1)
[0060]
In such an embodiment, the conditions b1 to b3Meets the requirements ofIt is desirable.
[0061]
For example, in a golf club having a high-friction face surface, for example, the depth d of the punch mark 5 provided on the face surface 3 is 0.5 to 1.0 mm, the area S of the punch mark is 2.0 to 2.8 mm @ 2, and adjacent. The distance k between the punch marks is 4.3 to 6.0 mm.To do.
[0062]
The punch mark depth d is less than 0.5 mm, and the punch mark area S is 2.0 mm.²When the distance k is less than or less than 6.0 mm, the effect of increasing the friction coefficient of the face surface 3 tends to be relatively reduced. On the contrary, if the depth d of the punch mark is larger than 1.0 mm and the interval k between the punch marks is less than 4.3 mm, it is not preferable because the golf rule is not satisfied.
[0063]
Further, when the punch marks 5 are provided on all the clubs in the set, the punch marks 5 formed on the highest and lowest golf clubs are based on, for example, the punch marks 5 formed on the golf club having the high friction face surface. Then, both the depth d and the area S are 80% or less, and the punch mark interval K is 120%.That's it.
[0064]
(Third embodiment)
As another method for changing the friction coefficient of the face surface 3, as shown in FIG. 6, for example, fine unevenness 6 is applied to the face surface 3 by sandblasting or the like. Such a friction coefficient of the face surface 3 is proportional to the surface roughness, for example, the ten-point average roughness R. Therefore, in this example, each golf club of the iron golf club set satisfies the following condition c1 where the ten-point average roughness R of the face surface of the club head isFulfill.
[0065]
c1) When the ten-point average roughness of the face surface of the i-th (i = 1 to q) club head is Ri
R1 <Rm and
Rm> Rq and
Between i = 1 and i = m (or m1), Ri ≦ R (i + 1) and
Between i = m (or m2) and i = q, Ri ≧ R (i + 1)
[0066]
Note that in a golf club having a high friction face surface, the ten-point average roughness of the face surface 3 is, for example, 20 μm or more.To. More preferably, it is 30 μm or more, and further preferably 40 μm or more. Also, in the low count and high count golf clubs, the 10-point average roughness of the face surface is 10 μm.Be as follows. Such a change in roughness can be easily made, for example, by changing the particle size of the blast particles.
[0067]
Note that the above-described conditions, that is, the ten-point average roughness of the groove 4, the punch mark 5, and the face surface may be used in appropriate combination.
[0068]
Although the preferred embodiment has been described in detail above, the present invention may be modified in various ways, for example, by changing the friction coefficient μ depending on whether the face surface 3 is plated or not. Yes.
[0069]
【Example】
(First embodiment)
A total of 6 iron golf club headsets including golf clubs with grooves on the face surface were manufactured according to the specifications shown in Table 1 (Examples 1 and 2 and Comparative Example 1), and a golf club was mounted with a shaft. In addition to being manufactured as a set, a test test was conducted with a swing robot, and the backspin amount, launch angle, carry, run, and total flight distance of the launched ball were measured. The swing robot was set to have a head speed (36.5 m / s) in a club having a club head with a loft angle of 15 degrees. Table 1 shows the club head specifications and Table 2 shows the test results.
[0070]
[Table 1]

[0071]
[Table 2]

[0072]
(Second embodiment)
A total of 6 iron golf club sets including golf clubs with punch marks on the face surface were made according to the specifications shown in Table 3 (Example 3, Comparative Example 2), and a test hit test was performed under the above conditions. Table 3 shows the club head specifications and test results.
[0073]
[Table 3]

[0074]
(Third embodiment)
A club set with the surface roughness changed by applying a sand plast treatment to the face surface was prototyped according to the specifications shown in Table 4 (Example 4 and Comparative Example 3), and a test hit test was performed under the conditions described above. Table 4 shows the club head specifications and the test results.
[0075]
[Table 4]

[0076]
As a result of the test, in the iron golf club set of the example, since the friction coefficient of the face surface of the golf club from the lowest golf club to the loft angle of 32 ° was reduced, the backspin amount of the balls hit with these clubs It can be confirmed that the carry increases even when the launch angle is small. In addition, in a golf club with a loft angle of 40 °, the backspin amount is reduced by setting the friction coefficient of the face surface large, and the carry is increased in combination with the sufficient launch angle. I can confirm that. Further, in the highest-numbered golf club, the coefficient of friction of the face surface is reduced, so that it can be confirmed that the backspin amount of the ball is relatively small, and the carry is increased by preventing the blow-up.
[0077]
【The invention's effect】
As described above, according to the first to sixth aspects of the invention, even in the beginner golfer, the backspin of the ball is increased and the carry is increased by the lowest golf club. In the highest golf club, the backspin of the ball can be reduced to prevent blow-up and carry. In addition, since the golf club with the highest friction coefficient on the face surface is set to the lowest count and the highest count except the highest count, the backspin amount of the ball can be reduced with a middle iron, for example. , Increase the carry.
[0078]
In particular, the invention according to claim 2 provides an iron golf club set and an iron golf club headset capable of flying a ball further through all counts by setting the loft angle of the golf club having a high friction face surface. Yes.
[Brief description of the drawings]
FIG. 1 is a side view showing an example of an iron golf club set of an embodiment.
FIGS. 2A and 2B are graphs showing the relationship between each count of the set of the present embodiment and the friction coefficient μ of the face surface.
FIG. 3 is a front view illustrating a part of golf clubs taken out from the set according to the embodiment.
FIG. 4 is a cross-sectional view of the head orthogonal to the groove on the face surface.
FIG. 5 is a front view illustrating a part of golf clubs taken out from the set according to the embodiment.
FIG. 6 is a front view illustrating a part of golf clubs taken out from the set according to the embodiment.
FIG. 7 is a graph showing the relationship between each count of a conventional set and the friction coefficient μ of the face surface.
FIG. 8 is a graph showing the relationship between the surface state of the face surface and the backspin amount of the ball.
FIG. 9 is a graph showing the relationship between the surface state of the face surface of a No. 3 iron and the ball launch angle.
FIG. 10 is a graph showing a relationship between a surface state of a face surface of a 5 iron and a ball launch angle.
FIG. 11 is a graph showing a relationship between a surface state of a face surface of a 7-iron and a ball launch angle.
FIG. 12 is a graph showing the relationship between the surface state of the SW face surface and the ball launch angle.
FIG. 13 is a cross-sectional view illustrating a process of impact between a ball and a face surface.
FIG. 14 is a graph showing the relationship between the elapsed time from impact and the shear force between the cover and core portion of the ball.
FIG. 15 is a diagram illustrating a method for measuring a friction coefficient of a face surface.
[Explanation of symbols]
2 Club head
3 Face side
4 groove
5 Punch mark
6 Concavities and convexities
S shaft
H club head

Claims (4)

Three or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
The high friction of the golf club face count m (or m1, m @ 2) is, meets the expression (1), and the friction coefficient of the face of the club head of the i-th (i = 1 to q) and μi While satisfying the requirement of time (2),
An iron golf club set, wherein a friction coefficient of the high friction face surface is 0.35 or more .

Three or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
Together with the iron golf club set comprises two or more by continuously one or count a golf club having a high friction face friction coefficient is large most of the face of the club head,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
When the golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1) and the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi. Satisfy the requirement of equation (2)

Moreover the iron golf club set consists golf club comprising a plurality of grooves on the face of the club head, the groove fulfills the following four conditions a1, a2, a3, a4 conditions,
In the golf club having the high friction face surface, the groove depth D of the groove is 0.4 to 0.5 mm , the groove width W is 0.7 to 0.9 mm , and the distance K between the grooves 4 is 2.1 to 3.5 mm , groove wall angle θ is 90 to 120 degrees,
The groove on the face surface of the golf club having the highest and the lowest golf clubs, when the groove 4 formed on the golf club having the high friction face surface is used as a reference, the groove depth and the groove width W are both 80% or less, and the groove wall angle. An iron golf club set in which both θ and groove interval K are 120% or more .
a1) When the groove depth of the i-th club head (i = 1 to q) is Di, D1 <Dm and Dm> Dq and between i = 1 and i = m (or m1), Di ≦ D ( i + 1) and between i = m (or m2) and i = q Di ≧ D (i + 1)
a2) When the groove width of the i-th club head (i = 1 to q) is Wi, W1 <Wm and Wm> Wq and between i = 1 and i = m (or m1), Wi ≦ W (i + 1) ) And between i = m (or m2) and i = q, Wi ≧ W (i + 1)
a3) When the distance between the grooves of the i-th (i = 1 to q) club head is Ki, K1> Km and Km <Kq, and between i = 1 and i = m (or m1) Then, Ki ≧ K (i + 1) and between i = m (or m2) and i = q, Ki ≦ K (i + 1)
a4) θ1> θm and θm <θq and i = 1 and i = m (or m1) where θi is an angle between the face surface of the i-th (i = 1 to q) club head and the groove wall of the groove Θi ≧ θ (i + 1) and between i = m (or m2) and i = q, θi ≦ θ (i + 1) Three or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
When the golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1) and the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi. While satisfying the requirement of formula (2),

The iron golf club set is composed of a golf club having a plurality of punch marks on a face surface of a club head,
Moreover, the punch mark satisfies the following three conditions b1, b2, and b3 ,
In addition, in a golf club having a high friction face surface, the depth d of the punch mark 5 provided on the face surface 3 is 0.5 to 1.0 mm , and the area S of the punch mark is 2.0 to 2.8 mm ² . The distance k between adjacent punch marks is 4.3 to 6.0 mm ,
The punch marks formed on the highest and lowest count golf clubs have a depth d and an area S of 80% or less, based on the punch marks formed on the golf club having the high friction face. An iron golf club set characterized by having an interval K of 120% or more .
b1) When the depth of the punch mark of the i-th club head (i = 1 to q) is di, d1 <dm and dm> dq and between i = 1 and i = m (or m1), di ≦ d (i + 1) and between i = m (or m2) and i = q, di ≧ d (i + 1)
b2) When the area of the punch mark of the i-th club head (i = 1 to q) is Si, S1 <Sm and Sm> Sq and between i = 1 and i = m (or m1), Si ≦ S ( i + 1) and between i = m (or m2) and i = q, Si ≧ S (i + 1)
b3) When the interval between adjacent punch marks of the i-th (i = 1 to q) club head is ki, k1> km and km <kq, and between i = 1 and i = m (or m1), ki ≧ k (i + 1) and between i = m (or m2) and i = q, ki ≦ k (i + 1) Three or more counts (i = 1 to q) from the lowest count (i = 1) golf club with the smallest loft angle to the highest count (i = q) golf club with the maximum loft angle An iron golf club set including a golf club,
The iron golf club set includes one or more golf clubs having a high friction face surface having the largest coefficient of friction of the face surface of the club head, or two consecutive golf clubs,
The loft angle of the high friction face surface golf club is 24 ° to 55 ° and the count is m (when there are a plurality of odd numbers of high friction face surface golf clubs, the intermediate count number is m. When there are an even number of golf clubs with a high friction face surface, the number of the lower middle number is m1, and the number of the upper middle number is m2, and various values in the club head of the golf club with the high friction face surface are specified. When the average value of these two values is used, and is indicated with a symbol m for convenience)
When the golf club count m (or m1, m2) of the high friction face surface satisfies the formula (1) and the friction coefficient of the face surface of the i-th (i = 1 to q) club head is μi. Satisfy the requirement of equation (2)

Moreover , in each golf club of the iron golf club set, the ten-point average roughness R of the face surface of the club head satisfies the following condition c1,
An iron golf club characterized in that a ten-point average roughness of a face surface of a golf club having a high friction face is 20 μm or more, and a ten-point average roughness of a face surface of a golf club having a low count and a high count is 10 μm or less. set.
c1) When the ten-point average roughness of the face surface of the i-th (i = 1 to q) club head is Ri, R1 <Rm and Rm> Rq and between i = 1 and i = m (or m1) Where Ri ≦ R (i + 1) and between i = m (or m2) and i = q, Ri ≧ R (i + 1)

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