JP2004298301A

JP2004298301A - Racket frame

Info

Publication number: JP2004298301A
Application number: JP2003093107A
Authority: JP
Inventors: Takeshi Yoshida; 健吉田; Yoji Honda; 洋二本多
Original assignee: Mizuno Corp
Current assignee: Mizuno Corp
Priority date: 2003-03-31
Filing date: 2003-03-31
Publication date: 2004-10-28

Abstract

<P>PROBLEM TO BE SOLVED: To provide a racket frame capable of obtaining an excellent ball hitting feeling and a control performance by efficiently suppressing and mitigating an impact and vibrations in a direction inside a surface and a direction outside the surface caused on the racket frame. <P>SOLUTION: The racket frame is composed by disposing a yoke member 3 between both left and right throat parts 6 of a racket frame main body 2. For the yoke member 3, a connection part 13 of a U-shaped cross section provided with a receiving part 11 for supporting the inner peripheral side face 10 of both left and right throat parts 6 and an engaging part 12 which is extended from the receiving part 11 to be externally fitted on both left and right throat parts 6 and parallel to a ball hitting surface, is formed at both end parts. The receiving part 11 and engaging part 12 of the connection part 13 are adhered and fixed to both left and right throat parts 6 via an elastic member 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、テニス用のラケットフレーム（以下、ラケットフレームと称する）に関するものであり、特に、フレーム本体とヨーク部との接続部を改良することにより衝撃及び、振動の抑制効果を高めるものである。
【０００２】
【従来の技術】
従来、ラケットフレームは、木や金属等の材料を用いて形成されていたが、現在ではラケットフレームに要求される強靭性、剛性及び、反発力等の諸特性を満足させ、しかも、必要な形状を得易いといった設計上の自由度が大きいことから繊維強化樹脂製のラケットフレームが主流を占めるようになった。
【０００３】
通常、この種のラケットフレーム３０は、例えば、図１０に示すように、打球部３１と、グリップ部３２及び、前記打球部３１とグリップ部３２を繋ぐスロート部３３とシャフト部３４とが繊維強化樹脂製の外殻層によって一体的に構成される管状構造を有し、前記グリップ部３２を構成する外殻の周囲に発泡合成樹脂或いは、非発泡合成樹脂等から成るグリップ部材３５並びに、グリップレザー３６を取着せしめて構成されている。
【０００４】
ところで、通常、ラケットフレーム３０でボールを打撃した時に生ずる衝撃や振動は、ラケットフレーム３０の打球部３１からグリップ部３２を介してプレーヤーの手に伝播されるものであるが、上記のように従来構造のラケットフレーム３０では、打撃時の衝撃緩和及び、振動吸収を前記グリップ部３２に取着されるグリップ部材３５自体の持つ弾性のみに依存していることから、衝撃緩和及び、振動吸収に劣り、打撃時に生じる振動や衝撃が減衰されずにそのままプレーヤーの手に伝播され易いという欠点があった。その結果、プレーヤーに不快な振動が伝わることによって打球感が損なわれてしまうばかりか、特に、昨今のラケットフレームにおいては、操作性を向上させるためにラケットフレーム自体の軽量化、又、反発特性を向上させるためにラケットフレームの高剛性化の動きが年々進行しつつあり、これと平行して打撃時の衝撃がプレーヤーへの身体的な負担を招き、手首や肘等にかかる疲労が大きくなって、所謂『テニス肘』等のスポーツ障害を誘発する恐れを有するものであった。
【０００５】
そのため、従来では、このような打撃時に生じるフレームの衝撃や振動を抑制緩和することを目的として、ラケットフレームに種々の衝撃及び、振動の抑制対策が講じられている。なかでも近年では、ボール打撃時にプレーヤーが体感し易い振動とされるラケットフレームの面外一次曲げ振動の腹に相当するヨーク部３７の領域に衝撃及び、振動の抑制機能を持たせるように構成されたラケットフレームが種々提案されている。
【０００６】
例えば、特許文献１には、図１１に示すように、環状のフェース部４１に対し２ヶ所で連なる略Ｖ字状のシャフト部４２を有するテニスラケット４０において、該フェース部４１及び／又は、シャフト部４２のフェース面方向における厚さをヨーク部４３に向かって徐々に大きくなるように構成することにより、該ヨーク部４３近傍領域の剛性を高め、打球時における該ヨーク部４３付近の振幅を小さく抑え、テニスラケット４０全体の振動を小さく抑制するように構成されたラケットフレームが提案され公知となっている。
【０００７】
又、特許文献２には、図１２に示すように、フレーム本体５１の左右枠部５２を連結するヨーク５３を振動減衰性の良い熱可塑性樹脂をマトリックス樹脂とする繊維強化熱可塑性樹脂で構成し、且つ、前記ヨーク５３の左右両端部５４をフレーム本体５１の左右枠部５２に一体成形したラケットフレーム５０が提案されている。
【０００８】
更に、特許文献３には、図１３乃至図１４に示すように、テニスラケット６０のヨーク部を構成する枠部品６１をフレーム本体６２と分離独立せしめ、該枠部品６１の端部６３とフレーム本体６２との間にクッション材料からなる帯状片６４を介在せしめることによって、ボール打撃時の振動及び、衝撃を絶縁し減少せしめるように構成されたラケットフレームが提案されている。この種の提案において、前記枠部品６１は、ストリングの張設圧力により、該枠部品６１の端部６３がフレーム本体６２の左右両枠部６５に設けられる突出部６６に係合保持されるようになっている。
【０００９】
【特許文献１】
特開平９−１２２２７８号公報
【特許文献２】
特開２０００−７０４１５号公報
【特許文献３】
特開平５−２１２１３８号公報
【００１０】
【発明が解決しようとする課題】
しかし、このような従来より公知のラケットフレームにおいては、以下のような欠点を有するものであった。
【００１１】
即ち、特許文献１に提案されるように、フェース部及び／又は、シャフト部のフェース面方向における厚さをヨーク部に向かって徐々に大きくなるように構成されるラケットフレームにおいては、面内方向（打球面に平行な方向）の振動減衰には寄与するが、面外方向（打球面に直交する方向）の振動を減衰することが出来ない。
又、前記ヨーク部近傍領域の剛性が他の領域に比して際立って大きくなってしまうことため、ボール打撃時におけるラケットフレームの撓みが滑らかとならず、又、撓りが少なくなることから、打撃時にボールを打球面で捕える時間（ボールと打球面の接触時間）が短く、ボレー以外の通常のストロークやサービス、スマッシュなどにおいて、打球をコントロールし難いという問題があると共に、打球感が硬く、良好なフィーリングが得られ難いものと予測される。
【００１２】
更に、フェース面方向における厚さが大きくなると、スイング時の空気抵抗が増し、振り抜き性が悪くなる。
【００１３】
又、特許文献２に提案されるように、フレーム本体の左右枠部を連結するヨークを繊維強化熱可塑性樹脂で構成するようにしたラケットフレームにおいては、振動減衰性の良い熱可塑性樹脂によってヨークを中心とした領域の振動をある程度抑制させることができるものの、前記ヨークは、その左右両端部がフレーム本体の左右枠部に一体成形によって不動状態で強固に固着されているため、打撃時における振動の減衰能は前記ヨークを構成する材料自体が持つ振動減衰特性に依存するのみで、大きな衝撃や振動を抑制する効果に乏しいという問題があった。
【００１４】
更に、熱可塑性樹脂は熱硬化性樹脂と比較して、使用環境により剛性等の特性が変化し易いという問題がある。そのため、補強繊維の含有率を高めたり、ヨークの肉厚を厚く設計しなければならず、その分質量が嵩み、ラケットフレーム自体の質量やバランス設計に悪影響を与えてしまうという欠点がある。
【００１５】
又、特許文献３に提案されるように、ヨーク部を構成する枠部品をフレーム本体と分離独立せしめ、該枠部品の端部とフレーム本体との間にクッション材料からなる帯状片を介在せしめるようにしたラケットフレームにおいては、前記枠部品とフレーム本体との間に介在される帯状片によって面内方向の衝撃緩和及び、振動減衰には寄与するが、面外方向の衝撃と振動を抑制することが出来ない。
【００１６】
更に、前記枠部品はフレーム本体と一体化しておらず、ストリングの張設圧力だけによって、該枠部品の端部がフレーム本体の左右両枠部に設けられた突出部に係合保持されるものであるため、使用により経時的にストリングの張力が低くなった場合などに打撃時の衝撃で前記枠部品がフレーム本体から離脱してしまうといった恐れがある。
【００１７】
そこで、本発明は、このような従来の問題点に鑑み、ラケットフレームに生起する面内方向と面外方向の衝撃及び振動を効率良く抑制緩和して、良好な打球感とコントロール性能が得られるラケットフレームを提供することを目的とするものである。
【００１８】
【課題を解決するための手段】
上記目的を達成するために、本発明のラケットフレームは以下のような構成とした。
即ち、本発明の請求項１に係るラケットフレームは、ラケットフレーム本体の左右両枠部にヨーク部材を架設してなるラケットフレームにおいて、前記ヨーク部材は、その両端部に前記左右両枠部の内周側面を支持する受承部と、該受承部から延在して前記左右両枠部に係合される打球面と平行な係合部とを備え、前記受承部及び、係合部が前記左右両枠部に弾性部材を介して接着固定されていることを特徴とするものである。
【００１９】
又、請求項２は、前記請求項１に係るラケットフレームであって、前記ヨーク部材は、その両端部に前記左右両枠部の内周側面を支持する受承部と、該受承部から延在して前記左右両枠部に外嵌される打球面と平行な係合部とを備えた断面コ字状の連結部を有し、該連結部の受承部及び、係合部が前記左右両枠部に弾性部材を介して接着固定されていることを特徴とするものである。
【００２０】
請求項３は、前記請求項１又は、２に係るラケットフレームであって、前記係合部は、前記左右両枠部の打球面と平行な表裏両側面に設けられる凹部に嵌入されていることを特徴とするものである。
【００２１】
請求項４は、前記請求項１に係るラケットフレームであって、前記ヨーク部材は、その両端部に前記左右両枠部の内周側面を支持する受承部と、該受承部から延在して前記左右両枠部に嵌挿される打球面と平行な係合部とを備えた断面凸字状の連結部を有し、該連結部の受承部及び、係合部が前記左右両枠部に弾性部材を介して接着固定されていることを特徴とするものである。
【００２２】
請求項５は、前記請求項１又は、４に係るラケットフレームであって、前記係合部は、前記左右両枠部の内周側面に穿設された凹部或いは、貫通孔に嵌挿されていることを特徴とするものである。
【００２３】
【発明の実施の形態】
以下、図面と共に詳記する好適な実施例により本発明を説明する。
（実施例１）
図１は、本実施例のラケットフレーム１の外観説明図、図２は、図１のｂ−ｂ線部における端面説明図、図３乃至図４は、図１のａ部領域の構成説明図を示す。
【００２４】
即ち、本実施例のラケットフレーム１は、図１に示すように、各々別個に形成された繊維強化樹脂製のラケットフレーム本体２と、ヨーク部材３とから構成されている。
【００２５】
前記ラケットフレーム本体２は、打球面４の大部分を取り囲むガット張設部５と、該ガット張設部５から連続するＶ字状のスロート部６と、シャフト部７及び、グリップ部８とから成っており、前記ラケットフレーム本体２の左右両スロート部６間に前記ヨーク部材３が架設されることにより、打球面４を囲む環状の打球部９が形成される構成となっている。
【００２６】
本実施例のラケットフレーム１において、前記ヨーク部材３は、図３乃至図４に示すように、その両端部に前記左右両スロート部６の内周側面１０を支持する受承部１１と、該受承部１１から延在して前記左右両スロート部６に外嵌される打球面４と平行な係合部１２とを備えた断面コ字状の連結部１３を形成しており、該連結部１３の受承部１１及び、係合部１２が前記左右両スロート部６に弾性部材１４を介して接着固定される構成となっている。
【００２７】
又、前記左右両スロート部６の打球面４と平行な表裏両側面１５には凹部１６が設けられており、この凹部１６に前記ヨーク部材３の係合部１２が弾性部材１４と共に嵌入されている。
【００２８】
このような本実施例のラケットフレーム１では、前記左右両スロート部６の打球面４と平行な表裏両側面１５（凹部１６の底壁１７）及び、これと直交する内周側面１０に弾性部材１４を介して前記ヨーク部材３の連結部１３を接着固定しているので、図２に示すように、ボール打撃時に、前記ヨーク部材３は、面内方向ｘ及び、面外方向ｙへ可動して弾性部材１４自体の持つ損失エネルギーを大幅に高めるようになる。
【００２９】
即ち、ボール打撃時に発生する面内方向の衝撃及び、振動に対しては、前記ヨーク部材３が面内方向ｘへ可動することで、該ヨーク部材３の受承部１１と前記左右両スロート部６の内周側面１０との間に介在する弾性部材が圧縮方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、衝撃を大幅に緩和させると共に、前記ヨーク部材３の係合部１２と前記左右両スロート部６の表裏両側面１５（凹部１６の底壁１７）との間に介在する弾性部材１４がせん断方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、プレーヤーに伝播される振動を減衰させることが可能となるものである。
【００３０】
又、ボール打撃時に発生する面外方向の衝撃及び、振動に対しては、前記ヨーク部材３が面外方向ｙへ可動することで、該ヨーク部材３の係合部１２と前記左右両スロート部６の表裏両側面１５（凹部１６の底壁１７）との間に介在する弾性部材１４が圧縮方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、衝撃を大幅に緩和させると共に、前記ヨーク部材３の受承部１１と前記左右両スロート部６の内周側面１０との間に介在する弾性部材１４がせん断方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、プレーヤーに伝播される振動を減衰させることが可能となる。
【００３１】
更に、本実施例のラケットフレーム１では、前記ヨーク部材３の連結部１３が前記弾性部材１４により前記左右両スロート部６と離隔されているため、前記ヨーク部材３を架設する連結部１３周辺の剛性が高まることがない。この結果、ボール打撃時におけるラケットフレーム１の撓みが滑らかとなり、又、大きな撓りが得られるようになるため、コントロール性に優れ、良好な打球感が得られる。
【００３２】
又、前記ヨーク部材３は、前記左右両スロート部６と分離することなく、弾性部材１４を介して接着固定されており、しかも、前記スロート部材３の連結部１３が、前記左右両スロート部６の内周側面１０と表裏両側面１５を支持係合する受承部１１と係合部１２とを備えた構成となっているため、前記ヨーク部材３と左右両スロート部６との固定が確実となり、長期に亙って使用しても前記ヨーク部材３が前記左右両スロート部６から離脱してしまうようなことがなく、耐久性に優れる。特に、本実施例では、前記ヨーク部材３の係合部１２を前記左右両スロート部６の表裏両側面１５に設けた凹部１６に嵌入させて機械的結合を行なっていることから両者の固定がより確実となる。又、前記凹部１６に係合部１２を嵌入させると、前記左右両スロート部６の表裏両側面１５を段差のない平滑な状態に形成することができ、外観上の違和感を解消できる。
【００３３】
このような本実施例のラケットフレーム１を製造するには、例えば、内圧成形用のチューブの周囲に複数枚のプリプレグシートを積層してラケットフレーム成形体を形成し、これを金型のフレーム形状としたキャビティ内に配置した後に、前記チューブ内に圧縮空気等を注入し加熱するといった繊維強化樹脂製ラケットフレームの通常の製造法において、前記ラケットフレーム成形体のヨーク相当部の内周面及び、表裏両面に弾性部材１４を被覆させた後、予め別途成形しておいた断面コ字状の連結部１３を有するヨーク部材３を、その連結部１３が前記弾性部材１４を把持するように固定させた状態でキャビティ内に装填し、加熱、加圧することによって本実施例のラケットフレーム１が成形される。尚、このような方法の他、前述した通常の内圧成形法によって、ヨーク相当部の表裏両面に凹部１６を設けたラケットフレーム本体２を予め硬化成形しておき、その後、前記凹部１６及び、内周面に弾性部材１４を被覆させた後、前記弾性部材１４を把持するようにヨーク部材３の連結部１３を接着固定するような方法とすることも可能である。
【００３４】
本実施例のラケットフレーム本体２を構成する主たる補強繊維としては、炭素繊維、ガラス繊維、ボロン繊維、芳香族ポリアミド繊維等種々のものが使用できるが、強度や質量、コスト等の面からも炭素繊維が好適である。又、マトリックス樹脂としては、エポキシ樹脂、ナイロン樹脂等が使用できるが、強度、耐久性の点でエポキシ樹脂が好適である。
【００３５】
又、前記弾性部材１４を形成する材料としては、成形性が良く、低温から高温までの温度変化による硬度変化が少ない軟質材料が望ましい。好ましい材料の一例としては、例えば、スチレン系エラストマー、ポリエステルエラストマー、塩ビ系エラストマー、ＥＶＡ、ＥＰＤＭ、熱可塑性ポリウレタンエラストマー、ポリアミドエラストマー等からなる弾性材料或いは、粘弾性材料から形成されることが好ましい。なかでも、前記材料の硬度が、ＪＩＳ−Ａ硬度４０以上、１００以下（ＪＩＳ−Ｄ硬度では１０〜５０程度）の硬度を有するものが好ましい。前記材料の硬度がＪＩＳ−Ａ硬度４０よりも小さいと、保形性を保つことが難しく、取扱い性に難が有り、又、前記硬度がＪＩＳ−Ａ硬度１００よりも大きいと、ヨーク部材３が可動し難くなり、良好な衝撃緩和と、振動減衰特性を発揮させることができない。
【００３６】
又更に、前記ヨーク部材３を形成する材料としては、前記弾性部材１４を形成する材料との接着性が良く、しかも軽量で、高張力で張設されるガットを支持するのに必要な強度と剛性が得られる材料が望ましい。例えばその一例として、炭素繊維、ガラス繊維、ボロン繊維、芳香族ポリアミド繊維等を補強繊維とした繊維強化樹脂材料が強度及び、剛性が高く好適である。又、その他、ＡＢＳ樹脂、ポリプロピレン樹脂、塩化ビニル樹脂等の熱可塑性樹脂による射出成形品を使用することも可能である。
【００３７】
前記ヨーク部材３の連結部１３の形状寸法は、ラケットフレーム本体２との連結強度及び、衝撃や振動の抑制効果、更に、質量などを加味して多くの実験を行なった結果、前記連結部１３の前記左右両スロート部６に沿う長さＬは３０ｍｍ〜１００ｍｍ、とりわけ６０ｍｍ〜８０ｍｍの範囲内にあることが好ましい。前記連結部１３の長さＬが、３０ｍｍより小さいと、ラケットフレーム本体２との連結強度が十分に得られず、耐久性に問題が生じる恐れがあると共に、弾性部材１４との接触面積が小さくなり、衝撃や振動の抑制に関して十分な効果が期待できなくなる。又、前記長さＬが、１００ｍｍより長くなると、ヨーク部材３の質量が大きくなり過ぎ、ラケットフレーム１の振り抜き性が悪くなるという問題が生じる。
【００３８】
又、前記連結部１３における係合部１２の打球面４と平行な幅Ｗａは、前記左右両スロート部６の打球面４と平行な幅Ｗｂの０．５Ｗｂ〜１．０Ｗｂ、とりわけ０．７５Ｗｂ〜１．０Ｗｂの範囲内にあることが好ましい。前記係合部１２の幅Ｗａが前記左右両スロート部６の幅Ｗｂの０．５Ｗｂよりも小さいと、ラケットフレーム本体２との連結強度が十分に得られず、耐久性に問題が生じる恐れがあると共に、弾性部材１４との接触面積が小さくなり、面内方向の振動減衰と、面外方向の衝撃緩和に関して十分な効果が期待できなくなる。又、前記係合部１２の幅Ｗａが前記左右両スロート部６の幅Ｗｂの１．０Ｗｂよりも大きくなると、前記係合部１２が前記左右スロート部６の幅を超えて外周側面１８に張り出してしまうようになる為、不体制な外観を呈し、プレーヤーに違和感を与えてしまうことから好ましくない。
【００３９】
更に、前記弾性部材１４の肉厚ｔは、０．５ｍｍ〜３．０ｍｍ、とりわけ１．０ｍｍ〜２．０ｍｍの範囲内にあることが好ましい。前記肉厚ｔが０．５ｍｍよりも小さい場合では、満足のできるレベルにまで衝撃や振動を抑制させることができず、又、前記肉厚ｔが３．０ｍｍよりも大きい場合では、ラケットフレーム１自体の質量やバランスを損ねてしまう問題があり好ましくない。
【００４０】
尚、本実施例では、前記ヨーク部材３の受承部１１と前記左右両スロート部６の内周側面１０との間及び、前記ヨーク部材３の係合部１２と前記左右両スロート部６の表裏両側面１５（凹部１６の底壁１７）との間に弾性部材１４を介在せしめる例を説明したが、この他、図５乃至図６に示すように、前記係合部１２の前記左右両スロート部６に沿う長さＬ１を、凹部１６の長さＬ０よりも短く形成し、前記係合部１２の側壁１９と前記凹部１６の側壁２０との間に形成される間隙にも弾性部材１４を介在せしめるように構成することもできる。この場合、前記係合部１２の側壁１９と前記凹部１６の側壁２０との間に介在される弾性部材１４の損失エネルギーが作用し、打撃時の衝撃と振動の抑制効果をより一層高めることができると共に、前記係合部１２の側壁１９と前記凹部１６の側壁２０とが干渉することで生じる応力を前記弾性部材１４で和らげることができる。
【００４１】
本実施例において、前記ヨーク部材３と前記弾性部材１４との接着及び、前記弾性部材１４と左右両スロート部６との接着は、接着剤を用いて行なう方法の他、前記弾性部材１４を形成する材料として未加硫ゴムを用い、未硬化状態のラケットフレーム成形体に前記未加硫ゴムを介してヨーク部材３を固定させた状態で金型のキャビティ内に装填し、加熱、加圧成形することによって、ラケットフレーム本体２の硬化成形と同時に、未加硫ゴムの加硫及び、前記ヨーク部材３との接着を行なう方法とすることもできる。
【００４２】
（実施例２）
図７乃至図８は、本発明の実施例２の形態を表す構成説明図を示す。
【００４３】
即ち、本実施例のラケットフレームは、上述した実施例１と同様に、各々別個に形成された繊維強化樹脂製のラケットフレーム本体２と、ヨーク部材３とから構成されている。
【００４４】
本実施例のラケットフレームにおいて、前記ヨーク部材３は、図７乃至図８に示すように、その両端部に前記左右両スロート部６の内周側面１０を支持する受承部１１と、該受承部１１から延在して前記左右両スロート部６に嵌挿される打球面４と平行な係合部１２とを備えた断面凸字状の連結部１３を形成しており、該連結部１３の受承部１１及び、係合部１２が前記左右両スロート部６に弾性部材１４を介して接着固定される構成となっている。
【００４５】
又、前記左右両スロート部６には、その内周側面１０から外周側面１８に向けて貫通する貫通孔２３が設けられており、この貫通孔２３に前記ヨーク部材３の係合部１２が弾性部材１４と共に嵌挿されている。
【００４６】
このような本実施例のラケットフレームでは、上述した実施例１と同様に、ボール打撃時に発生する面内方向の衝撃及び、振動に対しては、前記ヨーク部材３が面内方向ｘへ可動することで、該ヨーク部材３の受承部１１と前記左右両スロート部６の内周側面１０との間に介在する弾性部材１４が圧縮方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、衝撃を大幅に緩和させると共に、前記ヨーク部材３の係合部１２における打球面と平行な表裏両側面２２と前記左右両スロート部６に穿設された貫通孔２３の内壁面２１との間に介在する弾性部材がせん断方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、プレーヤーに伝播される振動を減衰させることが可能となる。
【００４７】
又、ボール打撃時に発生する面外方向の衝撃及び、振動に対しては、前記ヨーク部材３が面外方向ｙへ可動することで、該ヨーク部材３の係合部１２における表裏両側面２２と前記左右両スロート部６に穿設された貫通孔２３の内壁面２１との間に介在する弾性部材１４が圧縮方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、衝撃を大幅に緩和させると共に、前記ヨーク部材３の受承部１１と前記左右両スロート部６の内周側面１０との間に介在する弾性部材１４がせん断方向に変形することによって、該部における弾性部材１４自体の損失エネルギーが高められ、プレーヤーに伝播される振動を減衰させることが可能となる。
【００４８】
【実施例】
本発明の効果を確認する為に、以下の実施例１と、比較例１〜３のテニス用のラケットフレームを用意した。
【００４９】
即ち、実施例１として用意したラケットフレームは、上述した実施の形態と同様、繊維強化樹脂製のラケットフレーム本体２と、該ラケットフレーム本体２とは別体に形成される繊維強化樹脂製のヨーク部材３とから構成されるものであって、図５乃至図６に示すように、受承部１１と係合部１２とを備えた断面コ字状の連結部１３を有するヨーク部材３を弾性部材１４を介してラケットフレーム本体２の左右両スロート部６に接着固定するように構成したものを用意した。前記ヨーク部材３の接着固定には、前記弾性部材１４を形成する材料として未加硫ゴムを用い、ラケットフレーム成形体の加熱硬化成形と同時に、前記未加硫ゴムを加硫させ、ラケットフレーム本体２とヨーク部材３とを一体的に接着させた。
尚、前記左右両スロート部６に形成する凹部１６の長さＬ０は、８０ｍｍとし、又、前記ヨーク部材３の連結部１３における係合部１２の長さＬ１は、７５ｍｍで、前記係合部１２の打球面４と平行な幅Ｗａは、前記左右両スロート部６の幅Ｗｂの１．０Ｗｂとし、又、前記弾性部材１４の肉厚ｔは、１．０ｍｍとして形成されたものを用意した。
【００５０】
比較例１としては、上記実施例１のラケットフレームを成型する金型を用い、ラケットフレーム本体とヨーク部材とを繊維強化樹脂で一体的に形成した構成のラケットフレームを用意した。
【００５１】
又、比較例２としては、ポリアミド樹脂をマトリックス樹脂とした繊維強化熱可塑性樹脂でヨーク部材を形成し、該ヨーク部材の左右両端部をラケットフレーム本体の左右両スロート部に一体的に接着固定させたラケットフレームを用意した。
【００５２】
更に、比較例３としては、実施例１のヨーク部材３における係合部１２を省き、図９に示すように、スロート部材３の受承部１１のみが弾性部材１４を介して左右両スロート部６の内周側面１０に接着固定されてなる構成のラケットフレームを用意した。
【００５３】
これらの実施例１と、比較例１〜３のラケットフレームについて、実打試験を行なった。この実打試験では、一般のアマチュアプレーヤーを対象にして、実際に実施例１と比較例１〜３のラケットフレームでボールを打撃し、その際、プレーヤーが体感した打撃時の打球感（手に伝播する衝撃や振動）、操作性（振り抜き易さ）及び、コントロール性等の評価を行った。この時の試験結果を以下の表１に示す。
【００５４】
【表１】

【００５５】
このような試験結果より、実施例１のラケットフレームは、比較例１〜３のラケットフレームに比し、優れた操作性とコントロール性を保持しながらも、ボール打撃時の衝撃緩和と振動減衰において優れた効果が得られるものであることを確認できた。
【００５６】
【発明の効果】
以上のように、本発明のラケットフレームでは、面外一次曲げ振動の腹に相当するヨーク部領域において優れた衝撃緩和と振動減衰機能を発揮させることができるため、打撃時に心地良い打球感が得られると共に、プレーヤーの手首や肘等に加わる疲労を著しく低減させることができるものである。
【図面の簡単な説明】
【図１】本実施例のラケットフレームの外観説明図。
【図２】図１のｂ−ｂ線部における端面説明図。
【図３】図１のａ部領域の構成説明図。
【図４】図１のａ部領域の構成説明図。
【図５】その他の実施形態を表す説明図。
【図６】その他の実施形態を表す説明図。
【図７】その他の実施形態を表す説明図。
【図８】その他の実施形態を表す説明図。
【図９】比較例を表す説明図。
【図１０】従来のラケットフレームを表す説明図。
【図１１】従来のラケットフレームを表す説明図。
【図１２】従来のラケットフレームを表す説明図。
【図１３】従来のラケットフレームを表す説明図。
【図１４】従来のラケットフレームを表す説明図。
【符号の説明】
１ラケットフレーム
２ラケットフレーム本体
３ヨーク部材
４打球面
５ガット張設部
６スロート部
７シャフト部
８グリップ部
９打球部
１０内周側面
１１受承部
１２係合部
１３連結部
１４弾性部材
１５側面
１６凹部
１７底壁
１８外周側面
１９側壁
２０側壁
２１内壁面
２２側面
２３貫通孔
３０ラケットフレーム
３１打球部
３２グリップ部
３３スロート部
３４シャフト部
３５グリップ部材
３６グリップレザー
３７ヨーク部
４０テニスラケット
４１フェース部
４２シャフト部
４３ヨーク部
５０ラケットフレーム
５１フレーム本体
５２左右枠部
５３ヨーク
５４端部
６０テニスラケット
６１枠部品
６２フレーム本体
６３端部
６４帯状片
６５枠部
６６突出部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a racket frame for tennis (hereinafter referred to as a racket frame), and in particular, improves the effect of suppressing impacts and vibrations by improving the connecting portion between the frame main body and the yoke portion. .
[0002]
[Prior art]
Conventionally, racket frames were formed using materials such as wood and metal, but now they satisfy various characteristics such as toughness, rigidity, and repulsive force required for racket frames, and they also have the required shape. Since the degree of freedom in design is easy to obtain, a racket frame made of fiber reinforced resin has come to dominate.
[0003]
Normally, as shown in FIG. 10, for example, this type of racket frame 30 includes a hitting portion 31, a grip portion 32, and a throat portion 33 and a shaft portion 34 that connect the hitting ball portion 31 and the grip portion 32. A grip member 35 having a tubular structure integrally formed by a resin outer shell layer and made of foamed synthetic resin or non-foamed synthetic resin around the outer shell constituting the grip portion 32, and grip leather 36 is attached.
[0004]
By the way, normally, the impact and vibration generated when a ball is hit with the racket frame 30 are propagated from the hitting part 31 of the racket frame 30 to the player's hand through the grip part 32. The racket frame 30 having the structure is inferior in shock relaxation and vibration absorption because the shock relaxation and vibration absorption at the time of impact depend only on the elasticity of the grip member 35 attached to the grip portion 32 itself. However, there is a drawback that vibrations and impacts generated at the time of hitting are not attenuated and are easily transmitted to the player's hand. As a result, unpleasant vibration is transmitted to the player, and the feeling of hitting the ball is impaired. Particularly, in recent racket frames, the racket frame itself is reduced in weight and rebound characteristics in order to improve operability. In order to improve the movement of the racket frame, the movement of the racket frame is progressing year by year, and in parallel with this, the impact at the time of hitting causes a physical burden on the player and the fatigue on the wrist, elbow, etc. increases. The so-called “tennis elbow” has a risk of inducing sports disorders.
[0005]
For this reason, conventionally, various measures for suppressing the impact and vibration of the racket frame have been taken for the purpose of suppressing and mitigating the impact and vibration of the frame generated at the time of hitting. In particular, in recent years, the structure of the yoke portion 37 corresponding to the antinode out-of-plane primary bending vibration of the racket frame, which is considered to be vibration that is easily felt by the player when hitting the ball, is provided with a function of suppressing impact and vibration. Various racket frames have been proposed.
[0006]
For example, in Patent Document 1, as shown in FIG. 11, in a tennis racket 40 having a substantially V-shaped shaft portion 42 connected to the annular face portion 41 at two locations, the face portion 41 and / or the shaft By configuring the thickness of the portion 42 in the face surface direction so as to gradually increase toward the yoke portion 43, the rigidity in the vicinity of the yoke portion 43 is increased, and the amplitude in the vicinity of the yoke portion 43 during hitting is reduced. A racket frame configured to suppress and suppress the vibration of the entire tennis racket 40 is proposed and publicly known.
[0007]
In Patent Document 2, as shown in FIG. 12, a yoke 53 that connects the left and right frame portions 52 of the frame main body 51 is made of a fiber reinforced thermoplastic resin using a thermoplastic resin having a good vibration damping property as a matrix resin. In addition, a racket frame 50 in which the left and right end portions 54 of the yoke 53 are integrally formed with the left and right frame portions 52 of the frame body 51 has been proposed.
[0008]
Further, in Patent Document 3, as shown in FIGS. 13 to 14, a frame part 61 constituting a yoke part of a tennis racket 60 is separated and independent from a frame main body 62, and an end 63 of the frame part 61 and the frame main body are separated. A racket frame configured to insulate and reduce vibration and impact at the time of hitting a ball by interposing a belt-like piece 64 made of a cushioning material between 62 and 62 has been proposed. In this type of proposal, the frame component 61 is configured such that the end portion 63 of the frame component 61 is engaged and held by the protruding portions 66 provided on the left and right frame portions 65 of the frame body 62 by the string tensioning pressure. It has become.
[0009]
[Patent Document 1]
JP-A-9-122278
[Patent Document 2]
JP 2000-70415 A
[Patent Document 3]
Japanese Patent Laid-Open No. 5-212138
[0010]
[Problems to be solved by the invention]
However, such a conventionally known racket frame has the following drawbacks.
[0011]
That is, as proposed in Patent Document 1, in the in-plane direction of the racket frame configured such that the thickness of the face portion and / or the shaft portion in the face surface direction gradually increases toward the yoke portion. Although it contributes to vibration attenuation in the direction (parallel to the ball striking surface), vibration in the out-of-plane direction (direction perpendicular to the ball striking surface) cannot be attenuated.
In addition, since the rigidity of the region near the yoke portion is significantly increased as compared with other regions, the racket frame is not smoothly bent at the time of hitting the ball, and the bending is reduced. At the time of hitting, the time for catching the ball with the ball striking surface (contact time between the ball and the ball striking surface) is short, and there is a problem that it is difficult to control the hit ball in normal strokes, services, smashes, etc. It is predicted that good feeling will be difficult to obtain.
[0012]
Further, when the thickness in the face surface direction is increased, the air resistance during swing is increased and the swing-out performance is deteriorated.
[0013]
In addition, as proposed in Patent Document 2, in a racket frame in which the yoke connecting the left and right frame portions of the frame body is made of fiber reinforced thermoplastic resin, the yoke is made of thermoplastic resin having good vibration damping properties. Although the vibration in the central region can be suppressed to some extent, the left and right end portions of the yoke are firmly fixed to the left and right frame portions of the frame main body in an immovable state, so that the vibration at the time of impact is The damping capacity depends only on the vibration damping characteristics of the material constituting the yoke, and there is a problem that the effect of suppressing a large impact or vibration is poor.
[0014]
Furthermore, compared to thermosetting resins, thermoplastic resins have a problem that characteristics such as rigidity are likely to change depending on the use environment. For this reason, it is necessary to increase the content of the reinforcing fibers or to increase the thickness of the yoke, which increases the mass, and has the disadvantage of adversely affecting the mass of the racket frame itself and the balance design.
[0015]
In addition, as proposed in Patent Document 3, the frame component constituting the yoke portion is separated and independent from the frame main body, and a belt-like piece made of a cushion material is interposed between the end of the frame component and the frame main body. In the racket frame, the strip-shaped piece interposed between the frame component and the frame body contributes to shock reduction and vibration attenuation in the in-plane direction, but suppresses shock and vibration in the out-of-plane direction. I can't.
[0016]
Further, the frame part is not integrated with the frame body, and the end of the frame part is engaged and held by the protrusions provided on the left and right frame parts of the frame body only by the string tensioning pressure. Therefore, there is a risk that the frame component may be detached from the frame body due to impact at the time of striking, for example, when the tension of the string decreases with time due to use.
[0017]
Therefore, in view of such a conventional problem, the present invention efficiently suppresses and relieves in-plane and out-of-plane impacts and vibrations generated in the racket frame, and provides a good shot feeling and control performance. The object is to provide a racket frame.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, the racket frame of the present invention has the following configuration.
That is, the racket frame according to claim 1 of the present invention is a racket frame in which yoke members are installed on both the left and right frame portions of the racket frame main body, and the yoke member has inner ends of the left and right frame portions at both ends thereof. A receiving portion that supports a peripheral side surface; and an engaging portion that extends from the receiving portion and that is parallel to the striking face that is engaged with the left and right frame portions, the receiving portion and the engaging portion Is bonded and fixed to the left and right frame portions via elastic members.
[0019]
In addition, a second aspect of the present invention is the racket frame according to the first aspect, wherein the yoke member includes a receiving portion that supports inner peripheral side surfaces of the left and right frame portions at both ends thereof, and the receiving portion. A connecting portion having a U-shaped cross section provided with an engaging portion extending in parallel with the striking face that is externally fitted to the left and right frame portions, and a receiving portion and an engaging portion of the connecting portion are provided It is characterized in that it is bonded and fixed to the left and right frame portions via elastic members.
[0020]
A third aspect of the present invention is the racket frame according to the first or second aspect, wherein the engaging portion is fitted into a recess provided on both front and back side surfaces parallel to the striking surfaces of the left and right frame portions. It is characterized by.
[0021]
According to a fourth aspect of the present invention, in the racket frame according to the first aspect, the yoke member includes a receiving portion that supports inner peripheral side surfaces of the left and right frame portions at both ends thereof, and extends from the receiving portion. A connecting portion having a convex section in cross section provided with an engaging portion parallel to the striking surface to be inserted into the left and right frame portions, and the receiving portion of the connecting portion and the engaging portion are the left and right It is characterized by being bonded and fixed to the frame part via an elastic member.
[0022]
A fifth aspect of the present invention is the racket frame according to the first or fourth aspect, wherein the engaging portion is inserted into a concave portion or a through-hole formed in an inner peripheral side surface of the left and right frame portions. It is characterized by being.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described by means of preferred embodiments which are described in detail in conjunction with the drawings.
(Example 1)
FIG. 1 is an external view of the racket frame 1 of the present embodiment, FIG. 2 is an end view of the bb line portion of FIG. 1, and FIGS. 3 to 4 are diagrams of the configuration of the a portion region of FIG. Indicates.
[0024]
That is, the racket frame 1 of the present embodiment is composed of a fiber reinforced resin-made racket frame body 2 and a yoke member 3 which are separately formed as shown in FIG.
[0025]
The racket frame body 2 includes a gut extending portion 5 that surrounds most of the hitting surface 4, a V-shaped throat portion 6 that continues from the gut extending portion 5, a shaft portion 7, and a grip portion 8. The yoke member 3 is installed between the left and right throat portions 6 of the racket frame main body 2, whereby an annular hitting ball portion 9 surrounding the hitting surface 4 is formed.
[0026]
In the racket frame 1 of the present embodiment, as shown in FIGS. 3 to 4, the yoke member 3 includes a receiving portion 11 that supports inner peripheral side surfaces 10 of the left and right throat portions 6 at both ends thereof, A connecting portion 13 having a U-shaped cross section is formed, which extends from the receiving portion 11 and includes a striking face 4 fitted to the left and right throat portions 6 and an engaging portion 12 in parallel. The receiving part 11 and the engaging part 12 of the part 13 are configured to be bonded and fixed to the left and right throat parts 6 via elastic members 14.
[0027]
The front and back side surfaces 15 parallel to the striking surfaces 4 of the left and right throat portions 6 are provided with recesses 16, and the engaging portions 12 of the yoke member 3 are fitted together with the elastic members 14 into the recesses 16. Yes.
[0028]
In such a racket frame 1 of this embodiment, elastic members are provided on the front and back side surfaces 15 (bottom wall 17 of the recess 16) parallel to the striking surfaces 4 of the left and right throat portions 6 and the inner peripheral side surface 10 orthogonal thereto. Since the connecting portion 13 of the yoke member 3 is bonded and fixed via 14, the yoke member 3 is movable in the in-plane direction x and the out-of-plane direction y when the ball is hit as shown in FIG. Thus, the loss energy of the elastic member 14 itself is greatly increased.
[0029]
That is, with respect to the impact and vibration in the in-plane direction generated when the ball is hit, the yoke member 3 is moved in the in-plane direction x, so that the receiving portion 11 of the yoke member 3 and the left and right throat portions are 6 is deformed in the compression direction, the loss energy of the elastic member 14 itself in the portion is increased, the impact is greatly reduced, and the yoke member 3 is The elastic member 14 interposed between the engaging portion 12 and both the front and back side surfaces 15 (the bottom wall 17 of the concave portion 16) of the left and right throat portions 6 is deformed in the shearing direction, whereby the elastic member 14 itself in the portion is deformed. Loss energy is increased, and vibrations transmitted to the player can be attenuated.
[0030]
Further, against the impact and vibration in the out-of-plane direction generated when the ball is hit, the yoke member 3 moves in the out-of-plane direction y, so that the engaging portion 12 of the yoke member 3 and the left and right throat portions The elastic member 14 interposed between the front and back side surfaces 15 (bottom wall 17 of the recess 16) of FIG. 6 is deformed in the compression direction, so that the loss energy of the elastic member 14 itself in the portion is increased and the impact is greatly increased. The elastic member 14 interposed between the receiving portion 11 of the yoke member 3 and the inner peripheral side surface 10 of the left and right throat portions 6 is deformed in the shearing direction, so that the elastic member 14 itself in the portion is relaxed. The loss energy of the player is increased, and the vibration transmitted to the player can be attenuated.
[0031]
Further, in the racket frame 1 of the present embodiment, the connecting portion 13 of the yoke member 3 is separated from the left and right throat portions 6 by the elastic member 14, so that the periphery of the connecting portion 13 around which the yoke member 3 is laid. There is no increase in rigidity. As a result, the racket frame 1 is smoothly bent at the time of hitting the ball, and a large bend can be obtained. Therefore, the controllability is excellent and a good shot feeling can be obtained.
[0032]
The yoke member 3 is bonded and fixed via an elastic member 14 without being separated from the left and right throat portions 6, and the connecting portion 13 of the throat member 3 is connected to the left and right throat portions 6. Since the receiving portion 11 and the engaging portion 12 that support and engage the inner peripheral side surface 10 and the front and back side surfaces 15 are provided, the yoke member 3 and the left and right throat portions 6 are securely fixed. Thus, even when used over a long period of time, the yoke member 3 is not detached from the left and right throat portions 6 and is excellent in durability. In particular, in this embodiment, since the engagement portion 12 of the yoke member 3 is fitted into the recesses 16 provided on the front and back side surfaces 15 of the left and right throat portions 6, both are fixed. More certain. Further, when the engaging portion 12 is fitted into the concave portion 16, both the front and back side surfaces 15 of the left and right throat portions 6 can be formed in a smooth state without a step, and the uncomfortable appearance can be eliminated.
[0033]
In order to manufacture such a racket frame 1 of the present embodiment, for example, a plurality of prepreg sheets are laminated around an inner pressure forming tube to form a racket frame molded body, and this is formed into a mold frame shape. In a normal manufacturing method of a fiber-reinforced resin racket frame such as injecting compressed air into the tube and heating it after being placed in the cavity, the inner peripheral surface of the yoke equivalent part of the racket frame molded body, and After the elastic member 14 is coated on both the front and back surfaces, the yoke member 3 having a connecting portion 13 having a U-shaped cross section, which is separately formed in advance, is fixed so that the connecting portion 13 holds the elastic member 14. In this state, the racket frame 1 of this embodiment is molded by loading into the cavity, heating and pressurizing. In addition to this method, the racket frame body 2 provided with the recesses 16 on both the front and back surfaces of the yoke equivalent portion is previously cured and molded by the above-described normal internal pressure molding method. It is also possible to use a method in which the connecting portion 13 of the yoke member 3 is bonded and fixed so that the elastic member 14 is gripped after the elastic member 14 is coated on the peripheral surface.
[0034]
As main reinforcing fibers constituting the racket frame main body 2 of the present embodiment, various fibers such as carbon fibers, glass fibers, boron fibers, and aromatic polyamide fibers can be used, but carbon is also used in terms of strength, mass, cost, and the like. Fiber is preferred. Moreover, as a matrix resin, an epoxy resin, a nylon resin, or the like can be used, but an epoxy resin is preferable in terms of strength and durability.
[0035]
Further, as the material for forming the elastic member 14, it is desirable to use a soft material that has good moldability and little hardness change due to temperature change from low temperature to high temperature. As an example of a preferable material, for example, it is preferably formed from an elastic material or a viscoelastic material made of a styrene elastomer, a polyester elastomer, a vinyl chloride elastomer, EVA, EPDM, a thermoplastic polyurethane elastomer, a polyamide elastomer, or the like. Among them, the material having a hardness of JIS-A hardness 40 or more and 100 or less (about 10 to 50 in JIS-D hardness) is preferable. If the hardness of the material is less than JIS-A hardness 40, it is difficult to maintain shape retention and handling is difficult, and if the hardness is greater than JIS-A hardness 100, the yoke member 3 is It becomes difficult to move, and good impact relaxation and vibration damping characteristics cannot be exhibited.
[0036]
Furthermore, the material for forming the yoke member 3 has good adhesiveness with the material for forming the elastic member 14 and is light in weight and has the strength necessary to support a gut stretched with high tension. A material that can provide rigidity is desirable. For example, as an example, a fiber reinforced resin material using carbon fiber, glass fiber, boron fiber, aromatic polyamide fiber or the like as a reinforcing fiber is preferable because of its high strength and rigidity. In addition, it is also possible to use an injection-molded product made of a thermoplastic resin such as ABS resin, polypropylene resin, or vinyl chloride resin.
[0037]
The shape and dimensions of the connecting portion 13 of the yoke member 3 were determined as a result of many experiments conducted in consideration of the connection strength with the racket frame main body 2, the effect of suppressing impact and vibration, and the mass. The length L along the left and right throat portions 6 is preferably in the range of 30 mm to 100 mm, particularly 60 mm to 80 mm. If the length L of the connecting portion 13 is smaller than 30 mm, the connecting strength with the racket frame main body 2 cannot be sufficiently obtained, there is a possibility that a problem in durability may occur, and the contact area with the elastic member 14 is small. Therefore, a sufficient effect cannot be expected with respect to suppression of impact and vibration. Moreover, when the length L is longer than 100 mm, the mass of the yoke member 3 becomes too large, and there arises a problem that the swingability of the racket frame 1 is deteriorated.
[0038]
Further, the width Wa parallel to the ball striking face 4 of the engaging portion 12 in the connecting portion 13 is 0.5 Wb to 1.0 Wb, particularly 0.75 Wb, of the width Wb parallel to the ball striking face 4 of the left and right throat portions 6. It is preferable to be within the range of -1.0 Wb. If the width Wa of the engaging portion 12 is smaller than 0.5 Wb of the width Wb of the left and right throat portions 6, sufficient connection strength with the racket frame body 2 cannot be obtained, and there is a possibility that a problem in durability may occur. At the same time, the contact area with the elastic member 14 is reduced, and a sufficient effect cannot be expected with respect to vibration damping in the in-plane direction and impact relaxation in the out-of-plane direction. Further, when the width Wa of the engaging portion 12 is larger than 1.0 Wb of the width Wb of the left and right throat portions 6, the engaging portion 12 projects over the outer side surface 18 beyond the width of the left and right throat portions 6. Therefore, it is not preferable because it gives an uncomfortable appearance and makes the player feel uncomfortable.
[0039]
Further, the thickness t of the elastic member 14 is preferably in the range of 0.5 mm to 3.0 mm, particularly 1.0 mm to 2.0 mm. When the wall thickness t is smaller than 0.5 mm, the impact and vibration cannot be suppressed to a satisfactory level, and when the wall thickness t is larger than 3.0 mm, the racket frame 1 There is a problem that the mass and balance of itself are impaired, which is not preferable.
[0040]
In this embodiment, between the receiving portion 11 of the yoke member 3 and the inner peripheral side surface 10 of the left and right throat portions 6 and between the engaging portion 12 of the yoke member 3 and the left and right throat portions 6. Although an example in which the elastic member 14 is interposed between the front and back side surfaces 15 (the bottom wall 17 of the recess 16) has been described, in addition to this, as shown in FIGS. The length L1 along the throat portion 6 is formed to be shorter than the length L0 of the concave portion 16, and the elastic member 14 is also formed in the gap formed between the side wall 19 of the engaging portion 12 and the side wall 20 of the concave portion 16. It can also comprise so that it may interpose. In this case, the loss energy of the elastic member 14 interposed between the side wall 19 of the engaging portion 12 and the side wall 20 of the concave portion 16 acts to further enhance the impact and vibration suppression effect at the time of impact. In addition, the elastic member 14 can relieve stress generated by the interference between the side wall 19 of the engaging portion 12 and the side wall 20 of the recess 16.
[0041]
In this embodiment, the yoke member 3 and the elastic member 14 and the elastic member 14 and the left and right throat portions 6 are bonded together by a method using an adhesive, and the elastic member 14 is formed. An unvulcanized rubber is used as a material to be used, and the yoke member 3 is fixed to an uncured racket frame molded body through the unvulcanized rubber, and is loaded into a mold cavity, and is heated and pressed. By doing so, it is also possible to adopt a method in which the vulcanized rubber is vulcanized and bonded to the yoke member 3 at the same time as the racket frame body 2 is cured and molded.
[0042]
(Example 2)
7 to 8 are structural explanatory views showing the form of the second embodiment of the present invention.
[0043]
That is, the racket frame of the present embodiment is constituted by a fiber reinforced resin-made racket frame body 2 and a yoke member 3 which are separately formed, as in the first embodiment.
[0044]
In the racket frame of this embodiment, as shown in FIGS. 7 to 8, the yoke member 3 has a receiving portion 11 that supports inner peripheral side surfaces 10 of the left and right throat portions 6 at both ends thereof, and the receiving portion 11. A connecting portion 13 having a convex cross section is formed, which extends from the support portion 11 and includes a striking surface 4 that is fitted into the left and right throat portions 6 and an engaging portion 12 that is parallel to the hitting surface 4. The receiving part 11 and the engaging part 12 are bonded and fixed to the left and right throat parts 6 via elastic members 14.
[0045]
The left and right throat portions 6 are provided with through holes 23 penetrating from the inner peripheral side surface 10 toward the outer peripheral side surface 18, and the engaging portions 12 of the yoke member 3 are elastically inserted into the through holes 23. It is inserted together with the member 14.
[0046]
In such a racket frame of the present embodiment, the yoke member 3 is movable in the in-plane direction x with respect to impact and vibration in the in-plane direction generated at the time of hitting the ball, as in the first embodiment. Thus, the elastic member 14 interposed between the receiving portion 11 of the yoke member 3 and the inner peripheral side surface 10 of the left and right throat portions 6 is deformed in the compression direction, so that the elastic member 14 itself in the portion is deformed. Loss energy is increased and the impact is remarkably reduced, and both the front and back side surfaces 22 parallel to the striking surface of the engaging portion 12 of the yoke member 3 and the through holes 23 formed in the left and right throat portions 6 are formed. When the elastic member interposed between the wall surface 21 is deformed in the shear direction, the loss energy of the elastic member 14 itself in the portion is increased, and the vibration transmitted to the player is attenuated. The ability.
[0047]
Further, against the impact and vibration in the out-of-plane direction that occurs when the ball is hit, the yoke member 3 moves in the out-of-plane direction y, so that both the front and back side surfaces 22 in the engaging portion 12 of the yoke member 3 When the elastic member 14 interposed between the inner wall surface 21 of the through hole 23 formed in the left and right throat portions 6 is deformed in the compression direction, the loss energy of the elastic member 14 itself in the portion is increased. While greatly reducing the impact, the elastic member 14 interposed between the receiving portion 11 of the yoke member 3 and the inner peripheral side surface 10 of the left and right throat portions 6 is deformed in the shear direction, thereby The loss energy of the elastic member 14 itself is increased, and the vibration transmitted to the player can be attenuated.
[0048]
【Example】
In order to confirm the effects of the present invention, tennis racket frames of Example 1 and Comparative Examples 1 to 3 below were prepared.
[0049]
That is, the racket frame prepared as Example 1 is a fiber reinforced resin racket frame main body 2 and a fiber reinforced resin yoke formed separately from the racket frame main body 2 as in the above-described embodiment. As shown in FIGS. 5 to 6, the yoke member 3 having a U-shaped connecting portion 13 having a receiving portion 11 and an engaging portion 12 is elastically formed. What was comprised so that it might adhere and fix to the both right and left throat parts 6 of the racket frame main body 2 via the member 14 was prepared. For bonding and fixing the yoke member 3, unvulcanized rubber is used as a material for forming the elastic member 14, and the uncured rubber is vulcanized simultaneously with heat curing molding of the racket frame molded body, and the racket frame main body is vulcanized. 2 and the yoke member 3 were bonded together.
The length L0 of the recess 16 formed in the left and right throat portions 6 is 80 mm, and the length L1 of the engaging portion 12 in the connecting portion 13 of the yoke member 3 is 75 mm. A width Wa parallel to the striking surface 4 of 12 is set to 1.0 Wb of the width Wb of the left and right throat portions 6, and a thickness t of the elastic member 14 is prepared to be 1.0 mm. .
[0050]
As Comparative Example 1, a racket frame having a configuration in which a racket frame body and a yoke member were integrally formed of fiber reinforced resin using a mold for molding the racket frame of Example 1 was prepared.
[0051]
In Comparative Example 2, the yoke member is formed of a fiber reinforced thermoplastic resin using a polyamide resin as a matrix resin, and the left and right ends of the yoke member are integrally bonded and fixed to the left and right throat portions of the racket frame body. A racket frame was prepared.
[0052]
Furthermore, as Comparative Example 3, the engaging portion 12 in the yoke member 3 of Example 1 is omitted, and as shown in FIG. 9, only the receiving portion 11 of the throat member 3 has both left and right throat portions via the elastic member 14. A racket frame configured to be bonded and fixed to the inner peripheral side surface 10 of 6 was prepared.
[0053]
An actual hit test was performed on the racket frames of Example 1 and Comparative Examples 1 to 3. In this actual hit test, a ball is hit with a racket frame of Example 1 and Comparative Examples 1 to 3 for a general amateur player. Impacts and vibrations to be propagated), operability (ease of swinging out), controllability, etc. were evaluated. The test results at this time are shown in Table 1 below.
[0054]
[Table 1]

[0055]
From such a test result, the racket frame of Example 1 is superior to the racket frames of Comparative Examples 1 to 3 in that it has excellent operability and controllability, while at the time of impact mitigation and vibration damping at the time of hitting the ball. It was confirmed that an excellent effect was obtained.
[0056]
【The invention's effect】
As described above, the racket frame of the present invention can exhibit excellent shock relaxation and vibration damping functions in the yoke region corresponding to the antinode of the out-of-plane primary bending vibration. In addition, the fatigue applied to the player's wrist and elbow can be significantly reduced.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the appearance of a racket frame according to an embodiment.
FIG. 2 is an explanatory diagram of an end surface taken along a line bb in FIG.
FIG. 3 is an explanatory diagram of a configuration of a region a in FIG. 1;
FIG. 4 is an explanatory diagram of a configuration of a region a in FIG. 1;
FIG. 5 is an explanatory diagram showing another embodiment.
FIG. 6 is an explanatory diagram showing another embodiment.
FIG. 7 is an explanatory diagram showing another embodiment.
FIG. 8 is an explanatory diagram showing another embodiment.
FIG. 9 is an explanatory diagram illustrating a comparative example.
FIG. 10 is an explanatory diagram showing a conventional racket frame.
FIG. 11 is an explanatory diagram showing a conventional racket frame.
FIG. 12 is an explanatory diagram showing a conventional racket frame.
FIG. 13 is an explanatory diagram showing a conventional racket frame.
FIG. 14 is an explanatory diagram showing a conventional racket frame.
[Explanation of symbols]
1 Racket frame
2 Racket frame body
3 Yoke member
4 Hitting surface
5 Gut tension section
6 Throat
7 Shaft
8 Grip part
9 Hitting ball
10 Inner peripheral side
11 Reception Department
12 Engagement part
13 Connecting part
14 Elastic members
15 side
16 recess
17 Bottom wall
18 peripheral side
19 Side wall
20 side walls
21 inner wall
22 side
23 Through hole
30 racket frame
31 Hitting ball
32 Grip part
33 Throat
34 Shaft
35 Grip member
36 grip leather
37 York
40 tennis rackets
41 Face part
42 Shaft
43 York
50 racket frame
51 frame body
52 Left and right frame
53 York
54 end
60 tennis rackets
61 Frame parts
62 Frame body
63 edge
64 Strip
65 Frame
66 Protrusion

Claims

In the racket frame formed by laying yoke members on the left and right frame portions of the racket frame main body, the yoke member includes a receiving portion that supports inner peripheral side surfaces of the left and right frame portions at both ends thereof, and the receiving portion. And an engaging portion parallel to the ball striking surface that is engaged with the left and right frame portions, and the receiving portion and the engaging portion are bonded and fixed to the left and right frame portions via elastic members. A racket frame characterized by being made.

The yoke member has a receiving portion that supports inner peripheral side surfaces of the left and right frame portions at both ends thereof, and is parallel to a striking surface that extends from the receiving portion and is externally fitted to the left and right frame portions. A connecting portion having a U-shaped cross section including an engaging portion, and the receiving portion of the connecting portion and the engaging portion are bonded and fixed to the left and right frame portions via elastic members. The racket frame according to claim 1.

The racket frame according to claim 1 or 2, wherein the engagement portion is fitted into a recess provided on both front and back side surfaces parallel to the hitting surfaces of the left and right frame portions.

The yoke member includes a receiving part that supports inner peripheral side surfaces of the left and right frame parts at both ends thereof, and a engaging member that extends from the receiving part and that is parallel to a striking surface that is inserted into the left and right frame parts. A connecting portion having a convex section in cross section, and a receiving portion and an engaging portion of the connecting portion are bonded and fixed to the left and right frame portions via elastic members. The racket frame according to claim 1.

5. The racket frame according to claim 1, wherein the engaging portion is fitted into a concave portion or a through hole formed in an inner peripheral side surface of the left and right frame portions.