JP3771170B2

JP3771170B2 - Steering shaft coupling structure and coupling method

Info

Publication number: JP3771170B2
Application number: JP2001382287A
Authority: JP
Inventors: 勲藤生; 勝利辻; 直樹下山
Original assignee: Yamada Manufacturing Co Ltd
Current assignee: Yamada Manufacturing Co Ltd
Priority date: 2001-01-25
Filing date: 2001-12-14
Publication date: 2006-04-26
Anticipated expiration: 2021-12-14
Also published as: JP2002293252A

Description

【０００１】
【発明の属する技術分野】
本発明は、ステアリング装置において、２つの軸部材同士をカシメ構造により非可動状態に連結固定するタイプであり、特に、カシメ部を形成し、両軸部材をしっかりと連結固定するのに大きな荷重を必要とせずにでき、コスト低減ができ、軸方向及び回転方向のガタを抑止することができるステアリングシャフトの連結方法に関する。
【０００２】
【従来の技術】
従来より、ステアリング装置のステアリングシャフトにおいて、異なる軸部材同士を非可動状態に連結固定する手段としては、溶接による固着や、固定ピン等にる固着具の使用等により、しっかりと連結固定されている。また、軸部材同士をカシメにより連結する構造が特許文献１に開示されている。これは、２部材の軸体から構成され、その２部材の一方を雄セレーションが形成された中実軸とし、他方を雌セレーションが形成された中空軸として、前記中空軸に中実軸を挿入して軸方向に伸縮可能としている。
【特許文献１】
特開平９−２７２４４７号
【０００３】
そして、中実軸の周方向に形成された周溝を利用して、該周溝箇所に該当する中空軸の外側位置に径方向内向きの陥没部が形成されたのち、次いで中空軸と中実軸とを相互に移動させ、前記陥没部を中実軸側外周のセレーションを食い込ませたものである。この中間軸の連結は、中実軸の円形状外周に対して接線方向に陥没部が形成されるものであり、所定以上の衝撃荷重を受けたときに、軸方向に短縮して衝撃吸収されるものである。
【０００４】
【発明が解決しようとする課題】
２部材より構成したステアリングシャフトの連結固定手段として、溶接や、固定ピン等を使用すると以下の欠点がある。即ち、溶接では、連結シャフト構成によって熱歪み等による熱影響が生じる。また固定ピンにして連結固定する場合では、嵌合孔の加工や、固定ピン等の部材が必要となる。さらに、嵌合孔と固定ピンとがしっかり嵌合されなかったり、工作精度が甘いと、軸方向，回転方向のガタが発生し、操舵フィーリングを損なうおそれがある。このため、嵌合孔と固定ピンは、高精度加工により、部材間のクリアランスを小さくし、ガタ発生を低減するようにしているので、コストが高くなる。以上のようなことから、溶接及び固定ピン等による連結固定手段の使用は好ましくない。
【０００５】
また、上記特許文献１に開示されたものは、所定以上の荷重がかかることにより、重合箇所が相互に安定した状態で移動することができるようになっている。これは、ステアリング装置にかかる衝撃を吸収するものであり、軸部材同士を非可動状態にしっかりと連結固定するものではない。
【０００６】
しかし、カシメ手段を介して２つの軸部材を非可動状態で連結固定するには、１つのカシメ部では連結強度が不足で、軸方向の衝撃に極めて弱く、２つの軸部材同士が相互に移動するおそれがある。そのために、複数のカシメ部が必要となるが、カシメ部が多くなると、連結作業時にそのカシメ部を介して軸部材同士が干渉しあい、大きな荷重が必要となり、製造機械も大がかりとなり、作業が極めて困難で、ひいてはコスト高となる。本発明の目的は、ステアリングシャフトにおける２つの軸部材をカシメ手段により連結固定するのに比較的小さな荷重にて行うことが可能となるようにすることにある。
【０００７】
【課題を解決するための手段】
そこで、発明者は、上記課題を解決すべく、鋭意，研究を重ねた結果、本発明を、軸端側から外歯車状軸部及び細径軸部が形成された中実軸と、内歯車状部が形成された中空軸とからなり、前記中実軸の外歯車状軸部と細径軸部とが前記中空軸の内歯車状部に挿入され、該中空軸の内歯車状部に前記外歯車状軸部の軸方向より短い適宜の間隔をおいて前記第１及び第２位置が設定され、該第１位置を前記細径軸部に位置させ、前記第２位置を前記細径軸部又は前記外歯車状軸部に形成された溝部に位置させ、前記第１及び第２位置に内歯車状部の内方に突出するカシメ変形部が形成され、次いで前記中実軸と中空軸とを軸方向に引き離し、前記第２位置に形成されたカシメ変形部が前記細径軸部又は前記外歯車状軸部に形成された前記溝部の位置から外歯車状軸部と係合し、次いで前記第１位置に形成されたカシメ変形部が細径軸部を軸方向に移動して、前記カシメ変形部が外歯車状軸部に軸方向及び回転方向を固定してなることを特徴とするステアリングシャフトの連結方法としたことにより、２つの軸部材同士をカシメ構造により非可動状態に連結固定するタイプとして、特にカシメ部を形成し、両軸部材をしっかりと連結固定するのに大きな荷重を必要とせずにでき、コスト低減ができ、しかも軸方向及び回転方向のガタを抑止することができ、上記課題を解決したものである。
【０００８】
【発明の実施の形態】
以下、本発明の実施形態を図面に基づいて、本発明の第１実施形態の連結方法について説明する。まず構成部材について説明する。ステアリングシャフトは、図１（Ａ）に示すように、ステアリング装置を構成する一部材であり、中実軸Ａと中空軸Ｂとから構成されるものである。その中実軸Ａは、図２（Ａ）に示すように、軸端部から軸方向に外歯車状軸部１及び細径軸部２が形成されている。外歯車状軸部１は、その軸方向に直交する断面が略歯車形状に形成されたもので、具体的にはセレーション又はスプライン等である。その外歯車状軸部１には、軸方向に沿って適宜の位置に軸周方向に溝部３が形成されている。また、中実軸Ａには、フランジ部４が形成されており、ステアリング装置を構成する他の部材との連結を可能としている〔図１（Ｂ），図４等参照〕。
【０００９】
前記中空軸Ｂは、管状の軸本体５の内周側に内歯車状部６が形成されたものである。該内歯車状部６は、前記中実軸Ａの外歯車状軸部１と噛み合う構成となっており、中実軸Ａと中空軸Ｂの相互に回転方向の伝達を行うことができる。その内歯車状部６は、軸方向に直交する断面が内歯車状であり、具体的には、前記外歯車状軸部１と同様にセレーション又はスプライン等である。
【００１０】
その中空軸Ｂは、軸端から軸方向に沿って第１位置Ｐ₁及び第２位置Ｐ₂が設定され、その第１位置Ｐ₁及び第２位置Ｐ₂には、図２（Ａ），（Ｂ）及び図４に示すように、それぞれカシメ変形部７が形成される。実際には、第１位置Ｐ₁及び第２位置Ｐ₂は、前記中実軸Ａとの連結固定作業時に、強固なる固定をするためのカシメ変形部７が形成される箇所であり〔図２（Ｂ）参照〕、連結固定をするための組立前には、図２（Ａ）に示すように、第１位置Ｐ₁及び第２位置Ｐ₂にはカシメ変形部７が形成されていない。前記中実軸Ａと中空軸Ｂとが軸方向に連結固定されるものであり、中実軸Ａの他端側はハンドル側シャフトとジョイントを介して連結され、また中空軸Ｂは、軸方向に伸縮可能な構造となっており、その他端側は、前輪の操舵機構側に連結される。
【００１１】
次に、第１実施形態の連結方法としての、前記中実軸Ａと前記中空軸Ｂとの連結固定の組立の工程について説明する。まず、前記中空軸Ｂの内周側に前記中実軸Ａの外歯車状軸部１及び細径軸部２が挿入される。このとき図４（Ａ），（Ｂ）に示すように、中空軸Ｂの軸端箇所に対して中実軸Ａの細径軸部２が深く挿入される。ここで、中空軸Ｂに第１位置Ｐ₁と第２位置Ｐ₂とが中空軸Ｂに設定される。前記第１位置Ｐ₁が軸端側であり、第２位置Ｐ₂が前記第１位置Ｐ₁よりも軸方向奥側に設定される。
【００１２】
そして、中空軸Ｂの第１位置Ｐ₁は、前記中実軸Ａの細径軸部２の箇所に対応させ、第２位置Ｐ₂は、前記溝部３の位置に対応させる。この状態で中空軸Ｂの第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれカシメ変形部７が形成される。該カシメ変形部７は、中空軸Ｂの第１位置Ｐ₁及び第２位置Ｐ₂のそれぞれの周方向に等間隔に複数が形成される。具体的には、等間隔に３箇所形成されるのが好適である〔図３（Ａ）参照〕が、２箇所形成されることもあるし〔図３（Ｂ）参照〕、１箇所のみに形成されることもある〔図３（Ｃ）参照〕。
【００１３】
前記カシメ変形部７は、中空軸Ｂの内周側に突出するようにして形成されるものである〔図２（Ｃ）参照〕。そして、中空軸Ｂが前記中実軸Ａから外れる方向に移動させる。ここで、第２位置Ｐ₂に形成されたカシメ変形部７は、前記溝部３の位置から外歯車状軸部１に移動し、そのままカシメ変形部７が外歯車状軸部１をしごくようにして外歯車状軸部１の軸端側に向かう〔図４（Ｃ）参照〕。
【００１４】
一方，第１位置Ｐ₁に形成されたカシメ変形部７は細径軸部２を軸方向に沿って移動し、前記第２位置Ｐ₂に形成されたカシメ変形部７が軸端に到達すると同時に、細径軸部２から外歯車状軸部１に移動する。そして、第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれ形成されたカシメ変形部７が外歯車状軸部１を軸方向に適宜の間隔をおいて、食い付くようにして強圧状態で当接し、中実軸Ａと中空軸Ｂとの連結固定作業が完了する〔図４（Ｄ）参照〕。
【００１５】
図５は、中実軸Ａに形成されたカシメ変形部７が中実軸Ａの外歯車状軸部１に食い込むようにして連結される工程を示す拡大図である。前記カシメ変形部７の外歯車状軸部１に対して移動する際に、該外歯車状軸部１の軸径方向に対して、カシメ変形部７が次第に外歯車状軸部１に食い込むように変形され、安定した締付状態にすることができる。
【００１６】
また、第１位置Ｐ₁及び第２位置Ｐ₂の２箇所にカシメ変形部７が設けられていても、外歯車状軸部１に食い付くカシメ変形部７は、第２位置Ｐ₂に形成されたカシメ変形部７、即ち外歯車状軸部１の溝部３に対応する位置に形成されたカシメ変形部７からである〔図５（Ａ）参照〕。その第２位置Ｐ₂のカシメ変形部７が外歯車状軸部１に対してしごき状態が安定したころに第１位置Ｐ₁に形成されたカシメ変形部７が細径軸部２から外歯車状軸部１に入り込み外歯車状軸部１に食い付き、第１位置Ｐ₁及び第２位置Ｐ₂のカシメ変形部７の外歯車状軸部１への食付きが完成する〔図５（Ｂ），（Ｃ）参照〕。
【００１７】
この中実軸Ａの細径軸部２側で形成された第１位置Ｐ₁のカシメ変形部７は、先に外歯車状軸部１に食い付いたカシメ変形部７の軸径方向、周方向のカシメ状態を安定させるとともに、第２位置Ｐ₂のカシメ変形部７の外歯車状軸部１に対する移動を案内しつつ、前記外歯車状軸部１の山，谷との食付き精度を確保でき、安定且つ強固なカシメ変形部７の食付き状態とすることができる。前記中実軸Ａの細径軸部２は、中空軸Ｂのカシメ変形部７を形成するだけでなく、ステアリングシャフトのヒューズ部としての役目もなし、万一の衝撃において、ヒューズ部とした細径軸部２が破損し、衝撃エネルギを遮断して一次衝撃を運転者へ伝えないようにすることができる。
【００１８】
前記中空軸Ｂにカシメ変形部７を軸方向に適宜距離をおいて、第１位置Ｐ₁及び第２位置Ｐ₂の２箇所に設けることで、連結部における曲げ方向の力に対して強度を確保することができる。さらに工作時においては、２箇所のカシメ変形部７が中実軸Ａの外歯車状軸部１への食付き移動を同時にすることがないので、中実軸Ａから中空軸Ｂを引き離す方向に移動させて、連結固定を行うときにも、大きな荷重によって食付き加工をすることが避けられ大荷重加工によるワークの余計な変形を防ぐことができる。
【００１９】
図６は、中実軸Ａの外歯車状軸部１に溝部３が形成されないタイプのもので、連結する工程を示している。この場合には、細径軸部２箇所で第１位置Ｐ₁及び第２位置Ｐ₂を設定し、カシメ変形部７が形成される〔図６（Ｂ）参照〕。そして、前述のタイプと同様に中空軸Ｂを中実軸Ａより引き出しカシメ変形部７を外歯車状軸部１に食い付かせるものである〔図６（Ｃ），（Ｄ）参照〕。
【００２０】
次に、本発明の第２実施形態の連結方法について説明する。その構成部材のステアリングシャフトの構成について、図７乃至図１２に基づいて説明する。まず前述したように、先の第１実施形態の連結方法における構成部材では、前記第１位置Ｐ₁及び第２位置Ｐ₂のカシメ変形部７は、中実軸Ａの外歯車状軸部１と中空軸Ｂの内歯車状部６とを軸方向に相対移動によって、前記中空軸Ｂの内方に突出するカシメ変形部７と外歯車状軸部１とを押圧状態で係合する構造としたものである。
【００２１】
第２実施形態の連結方法における構成部材では、図７，図１０等に示すように、前記第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれ形成されて設けられるカシメ変形部７，７，…に加えて、新たに設定される第３位置Ｐ₃にカシメ変形部７が設けられるものである。前記第３位置Ｐ₃は、前記中空軸Ｂに設定された第１位置Ｐ₁及び第２位置Ｐ₂の中間の所定位置に設定される。
【００２２】
具体的には、前記中空軸Ｂの内周側に前記中実軸Ａの外歯車状軸部１及び細径軸部２が挿入され、前記中空軸Ｂにそれぞれ第１位置Ｐ₁と第２位置Ｐ₂とが設定され、これら第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれカシメ変形部７が形成される。そして、前記第３位置Ｐ₃は、図７，図１０に示すように、前記第１位置Ｐ₁と前記第２位置Ｐ₂のカシメ変形部７，７における軸方向間であって、前記中空軸Ｂと固定状態に連結された前記中実軸Ａの外歯車状軸部１の中間にある軸周方向の溝部３に対応する位置が第３位置Ｐ₃となる。
【００２３】
そして、前記第３位置Ｐ₃にも中間カシメ変形部８が形成される。該中間カシメ変形部８は、前記第１位置Ｐ₁及び第２位置Ｐ₂に形成されたカシメ変形部７とほぼ同等形状である。その第３位置Ｐ₃に形成される中間カシメ変形部８は、図９（Ａ）及び図９（Ｂ）に示すように、中空軸Ｂの溝部３に係合する状態となる。また、通常は、図９（Ｃ）に示すように、前記中間カシメ変形部８は、中空軸Ｂの軸周方向に沿って複数形成される。
【００２４】
このように複数の中間カシメ変形部８，８，…が形成される場合には、軸周方向に等間隔で形成されることが好ましいが、必ずしも等間隔とする必要はない。また、必要に応じて、中間カシメ変形部８が軸周方向に２つのみ形成されることもある〔図９（Ｄ）参照〕。また中間カシメ変形部８は軸周方向に一つのみ形成されることもある〔図９（Ｅ）参照〕。また、前記第３位置Ｐ₃に形成される中間カシメ変形部８が溝部３に係合する状態は、図９（Ｂ）に示すように、該溝部３と中間カシメ変形部８とが少なくとも一部が当接する構造としたものであり、また中間カシメ変形部８が溝部３に係合するとともに押圧状態が加わるようにすることもある。また、中間カシメ変形部８が溝部３に入り込むが、このとき中間カシメ変形部８と溝部３の底とが非接触状態であってもかまわない。
【００２５】
また、前記中間カシメ変形部８を中空軸Ｂの軸周方向に沿って複数形成された場合には、図１０（Ａ）に示すように、前記第１位置Ｐ₁及び第２位置Ｐ₂のカシメ変形部７の軸周方向の位置に対して均等に適宜ずれていることが好ましい。すなわち、前記第１位置Ｐ₁及び第２位置Ｐ₂にカシメ変形部７，７，…がそれぞれ軸周方向に沿って等間隔に形成された場合、前記第３位置Ｐ₃の軸周方向に沿って形成されるそれぞれの中間カシメ変形部８，８，…は、軸周方向において隣接する前記カシメ変形部７，７間に位置するように形成されるものである。
【００２６】
たとえば、前記第１及び第２位置Ｐ₂を基準として、軸周方向に沿って複数のカシメ変形部７，７，…が等間隔に３箇所に形成されるとすれば、それぞれに軸周方向に沿って隣接するカシメ変形部７，７は、前記中空軸Ｂの直径方向中心を基準にして１２０度である〔図１０（Ｂ）は、第１位置Ｐ₁及び第２位置Ｐ₂におけるＸ₂−Ｘ₂矢視断面図〕。そして、前記第３位置Ｐ₃の軸周方向に形成される中間カシメ変形部８が前記軸周方向に隣接するカシメ変形部７，７の中間位置となるように設定して形成されると、カシメ変形部７と中間カシメ変形部８との軸周方向における角度は、ほぼ６０度均等にズレた位置に形成されることになる〔図１０（Ｃ）参照〕。
【００２７】
勿論、上記のように、カシメ変形部７及び中間カシメ変形部８は、軸周方向においてほぼ６０度ずれることに限定されるものではなく、適宜角度に設定されてもよい。また、前記第１位置Ｐ₁及び第２位置Ｐ₂のカシメ変形部７と、前記第３位置Ｐ₃の中間カシメ変形部８は、軸周方向にずれていることが好ましいが、必ずしもこの限りではなく、カシメ変形部７と中間カシメ変形部８とが軸方向に沿って同一位置に形成されたものであってもかまわない。この中空軸Ｂの第３位置Ｐ₃における中間カシメ変形部８と、中実軸Ａの溝部３との係合により、カシメ変形部７のみの係合による連結固定状態よりも更に強固な連結固定を得ることができる。
【００２８】
次に、第２実施形態の連結方法又は組立方法、すなわち中実軸Ａと中空軸Ｂとの連結固定の組立工程について説明する。この工程は先の実施形態とほぼ同様の工程となるが最終段階で異なる。まず、図１１（Ａ），（Ｂ）に示すように、前記中空軸Ｂの内周側に前記中実軸Ａの外歯車状軸部１及び細径軸部２が深く挿入され、前記中空軸Ｂに第１位置Ｐ₁と第２位置Ｐ₂とが中空軸Ｂに設定される。このとき、前記第１位置Ｐ₁が軸端側であり、第２位置Ｐ₂が前記第１位置Ｐ₁よりも軸方向奥側に設定される。
【００２９】
そして、図１１（Ｃ）に示すように、中空軸Ｂの第１位置Ｐ₁は、前記中実軸Ａの細径軸部２の箇所に対応させ、第２位置Ｐ₂は、前記溝部３の位置に対応させる。この状態で中空軸Ｂの第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれカシメ変形部７が形成される。該カシメ変形部７は、中空軸Ｂの第１位置Ｐ₁及び第２位置Ｐ₂のそれぞれの周方向に等間隔に複数が形成される。
【００３０】
前記カシメ変形部７は、中空軸Ｂの内周側に突出するようにして形成され、該中空軸Ｂを前記中実軸Ａから外れる方向に移動させる。ここで、第２位置Ｐ₂に形成されたカシメ変形部７は、図１１（Ｄ）に示すように、前記溝部３の位置から外歯車状軸部１に移動し、そのままカシメ変形部７が外歯車状軸部１をしごくようにして外歯車状軸部１の軸端側に向かう。
【００３１】
一方，第１位置Ｐ₁に形成されたカシメ変形部７は細径軸部２を軸方向に沿って移動し、前記第２位置Ｐ₂に形成されたカシメ変形部７が軸端に到達すると同時に、細径軸部２から外歯車状軸部１に移動し、前記第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれ形成されたカシメ変形部７が外歯車状軸部１を軸方向に適宜の間隔をおいて、食い付くようにして強圧状態で当接する〔図１１（Ｄ）参照〕。次に、前記中空軸Ｂの第３位置Ｐ₃に中間カシメ変形部８が形成されると、該中間カシメ変形部８は、中実軸Ａの溝部３に入り込む状態で係合する〔図１１（Ｅ）参照〕。これによって、中実軸Ａと中空軸Ｂとの連結固定が完了する。
【００３２】
図１２は、第２実施形態における工程を示す要部の拡大図であり、図１２（Ａ）乃至（Ｃ）では、前記中空軸Ｂの第１位置Ｐ₁及び第２位置Ｐ₂にカシメ変形部７が形成された状態で、中実軸Ａと中空軸Ｂとが所定の位置に設定され、その状態で、図１２（Ｄ）では、第３位置Ｐ₃に中間カシメ変形部８が形成され、該中間カシメ変形部８が溝部３に食い込む状態となっている。
【００３３】
【発明の効果】
次に、請求項１の発明は、軸端側から外歯車状軸部１及び細径軸部２が形成された中実軸Ａと、内歯車状部６が形成された中空軸Ｂとからなり、前記中実軸Ａの外歯車状軸部１と細径軸部２とが前記中空軸Ｂの内歯車状部６に挿入され、該中空軸Ｂの内歯車状部６に前記外歯車状軸部１の軸方向より短い適宜の間隔をおいて前記第１及び第２位置が設定され、該第１位置Ｐ₁を前記細径軸部２に位置させ、前記第２位置Ｐ₂を前記細径軸部２又は前記外歯車状軸部１に形成された溝部３に位置させ、前記第１及び第２位置に内歯車状部６の内方に突出するカシメ変形部７が形成され、次いで前記中実軸Ａと中空軸Ｂとを軸方向に引き離し、前記第２位置Ｐ₂に形成されたカシメ変形部７が前記細径軸部２又は前記外歯車状軸部１に形成された前記溝部３の位置から外歯車状軸部１と係合し、次いで前記第１位置Ｐ₁に形成されたカシメ変形部７が細径軸部２を軸方向に移動して、前記カシメ変形部７が外歯車状軸部１に軸方向及び回転方向を固定してなるステアリングシャフトの連結方法としたことにより、中実軸Ａと中空軸Ｂとの連結固定作業を効率的に行うことができ、強固なる連結固定とすることができる。
【００３４】
上記効果を詳述すると、第１位置Ｐ₁及び第２位置Ｐ₂にカシメ変形部７を形成するときには、前記中空軸Ｂの細径軸部２にて行うことになるので、外歯車状軸部１からカシメ変形部７の形成時になんら抵抗を受けることなく、容易に形成することができる。さらに、カシメ変形部７を形成してから中空軸Ｂを中実軸Ａから引き離す方向に移動させるときには、第２位置Ｐ₂に形成されたカシメ変形部７から外歯車状軸部１に移動し、第２位置Ｐ₂のカシメ変形部７が外歯車状軸部１の軸端位置に近接してから、第１位置Ｐ₁のカシメ変形部７が外歯車状軸部１に移動する。
【００３５】
したがって、中空軸Ｂに第１位置Ｐ₁及び第２位置Ｐ₂の２箇所にそれぞれ形成されたカシメ変形部７が中実軸Ａの外歯車状軸部１への食い付き移動を同時にすることがないので、前記中実軸Ａから中空軸Ｂを引き離す方向に移動させて、外歯車状軸部１の軸方向両端箇所でカシメ変形部７による食いつき状態の連結固定を行うときにも、大きな荷重によって食付き加工をする必要がなく、したがって大荷重加工による中実軸Ａ及び中空軸Ｂへの不必要な変形を防止することができる。
【００３６】
この中実軸Ａの細径軸部２側で形成された第１位置Ｐ₁のカシメ変形部７は、先に外歯車状軸部１に食い付いたカシメ変形部７の軸径方向、周方向のカシメ状態を安定させるとともに、第２位置Ｐ₂のカシメ変形部７の外歯車状軸部１に対する移動を案内しつつ、前記外歯車状軸部１の山，谷との食付き精度を確保でき、安定かつ強固なカシメ変形部７の食い付き状態とすることができる。
【００３７】
さらに、上記効果を詳述すると、中空軸Ｂが前記中実軸Ａから外れる方向に移動させるときに第２位置Ｐ₂に形成されたカシメ変形部７は、前記溝部３の位置から外歯車状軸部１に移動し、そのままカシメ変形部７が外歯車状軸部１をしごくようにして外歯車状軸部１の軸端側に向かう。前記溝部３は、外歯車状軸部１の領域に形成されているので、溝部３に対応して形成されたカシメ変形部７が外歯車状軸部１に沿って、該外歯車状軸部１の軸方向端部に到達する距離を少なくすることができ、作業効率を向上させるものである。
【００３８】
なお、前記外歯車状軸部１の細径軸部２側寄りの適宜の位置に周方向に沿って溝部３が形成され、前記第２位置Ｐ₂は前記溝部３の位置に一致させて前記カシメ変形部７が形成されることにより、中実軸Ａと中空軸Ｂとの連結固定作業をより一層効率的に行うことができる。また、前記中実軸Ａの細径軸部２は、ステアリングシャフトのヒューズ部としての役目もなすことができる。即ち、衝突時の衝撃において、細径軸部２が破損し、この部位で衝撃エネルギが遮断され、一次衝撃を運転者へ伝えることを防止することができるものである。
【００３９】
請求項２の発明は、軸端側から外歯車状軸部１と，該外歯車状軸部１のほぼ中間且つ軸周方向に形成された溝部３と，前記外歯車状軸部１の軸端に形成された細径軸部２とからなる中実軸Ａと、内歯車状部６が形成された中空軸Ｂとからなり、前記中実軸Ａの外歯車状軸部１と細径軸部２とが前記中空軸Ｂの内歯車状部６に挿入され、該中空軸Ｂの内歯車状部６に前記外歯車状軸部１の軸方向より短い適宜の間隔をおいて第１位置Ｐ₁及び第２位置Ｐ₂が設定され、前記第１位置Ｐ₁を前記細径軸部２に位置させ、第２位置Ｐ₂を前記細径軸部２又は外歯車状軸部１に形成された溝部３に位置させ、前記第１位置Ｐ₁及び第２位置Ｐ₂に内歯車状部６の内方に突出するカシメ変形部７が形成され、次いで前記中実軸Ａと中空軸Ｂとを軸方向に引き離し、前記第２位置Ｐ₂に形成されたカシメ変形部７が前記細径軸部２又は前記溝部３の位置から外歯車状軸部１と係合し、次いで前記第１位置Ｐ₁に形成されたカシメ変形部７が細径軸部２を軸方向に移動して、外歯車状軸部１に押圧状態で軸方向及び回転方向を固定させ、その第１位置Ｐ₁及び第２位置Ｐ₂の中間にて第３位置Ｐ₃が設定され、該第３位置Ｐ₃は前記外歯車状軸部１の溝部３に位置し、中空軸Ｂに内歯車状部６を前記溝部３に入り込むように中間カシメ変形部８が形成され、前記外歯車状軸部１に係合されてなるステアリングシャフトの連結方法としたことにより、中実軸Ａと中空軸Ｂとをより一層，強固なる連結固定とすることができるとともに、その連結固定作業の極めて効率的に行うことができる。
【００４０】
上記効果を詳述すると、前記中実軸Ａを前記中空軸Ｂに一旦，深く挿入し、第１位置Ｐ₁及び第２位置Ｐ₂にそれぞれカシメ変形部７を形成してから中空軸Ｂが前記中実軸Ａから外れる方向に移動させるときに第２位置Ｐ₂に形成されたカシメ変形部７は、前記溝部３の位置から外歯車状軸部１に移動するものであり、前記溝部３が外歯車状軸部１のほぼ中間位置に形成されているので、カシメ変形部７が溝部３から外歯車状軸部１の所定位置に到達する距離は短くて済む。
【００４１】
さらに、中実軸Ａと中空軸Ｂとを所定の位置に設定した後、前記第３位置Ｐ₃に中間カシメ変形部８を形成するので、該中間カシメ変形部８が中空軸Ｂの内周側に膨出する工程で、溝部３内に入り込むように形成され、比較的少ない抵抗で形成することができ、且つ中実軸Ａと中空軸Ｂとの軸方向における連結状態は極めて強固なものにできる。
【００４２】
なお、第１位置Ｐ₁及び第２位置Ｐ₂のカシメ変形部７，７，…を軸周方向に複数箇所（たとえば３箇所）に均等に設けた後に、前記第３位置Ｐ₃の中間カシメ変形部８，８，…を軸周方向に沿って複数箇所（たとえば３箇所）に均等に設けることで、前記第１位置Ｐ₁と第２位置Ｐ₂の軸周方向における隣接するカシメ変形部７，７間のカシメ変形されていない部分，すなわち未カシメ成形部位に前記中間カシメ変形部８，８，…が位置することとなる。これによって、カシメ変形部７と中間カシメ変形部８とは軸方向及び軸周方向において相互に距離をおいて存在しているので、カシメ成形による歪みが相互に及ぶことがなく中空軸Ｂの強度を劣化することがない。しかも、これらカシメ変形部７及び中間カシメ変形部８が形成される中空軸Ｂは、その軸径の大きなものでなくとも、軸周方向にカシメ成形箇所を多数設けることができ、これによって軽量，小型化を実現することができ、しかもカシメによる連結固定の強度を損なうことなく、連結構造を安定させることができる。
【図面の簡単な説明】
【図１】（Ａ）は本発明の第１実施形態の連結方法によるステアリングシャフトの全体を示す側面図、（Ｂ）は（Ａ）の一部断面にした要部拡大図である。
【図２】（Ａ）は本発明の第１実施形態の連結方法による中実軸と中空軸の要部斜視図、（Ｂ）は中実軸と中空軸の連結状態の斜視図、（Ｃ）は中空軸のカシメ変形部部分の拡大斜視図である。
【図３】（Ａ）は本発明の第１実施形態の連結方法によるカシメ変形部の数を周方向に３個としたタイプを示す要部断面図、（Ｂ）はカシメ変形部の数を周方向に２個としたタイプを示す要部断面図、（Ｃ）はカシメ変形部の数を周方向に１個としたタイプを示す要部断面図である。
【図４】（Ａ）は本発明の第１実施形態の連結方法による中実軸を中空軸に挿入しようとする状態図、（Ｂ）は中実軸を中空軸に挿入した状態図、（Ｃ）は中空軸の第１位置及び第２位置にカシメ変形部を形成した状態図、（Ｄ）は連結固定が完了した状態図である。
【図５】（Ａ）は本発明の第１実施形態の連結方法によるカシメ変形部が外歯車状軸部に食い込む前の拡大した状態図、（Ｂ）はカシメ変形部が外歯車状軸部に食い込み始めた拡大した状態図、（Ｃ）は連結固定が完了した拡大した状態図である。
【図６】（Ａ），（Ｂ），（Ｃ），（Ｄ）は本発明の第１実施形態の連結方法による外歯車状軸部に溝部が形成されないタイプの工程図である。
【図７】（Ａ）は本発明の第２実施形態の連結方法による中実軸と中空軸の要部斜視図、（Ｂ）は第２実施形態の連結方法による中実軸と中空軸の連結状態の斜視図である。
【図８】本発明の第２実施形態の連結方法による中空軸のカシメ変形部及び中間カシメ変形部箇所の拡大断面斜視図である。
【図９】（Ａ）は本発明の第２実施形態の連結方法による中空軸の中間カシメ変形部における部分の拡大縦断側面図、（Ｂ）は（Ａ）のＸ₁−Ｘ₁矢視断面図、（Ｃ）は中間カシメ変形部を軸周方向に３箇所形成した縦断正面図、（Ｄ）は中間カシメ変形部を軸周方向に２箇所形成した縦断正面図、（Ｅ）は中間カシメ変形部を軸周方向に１箇所形成した縦断正面図である。
【図１０】（Ａ）は本発明の第２実施形態の連結方法によるカシメ変形部と中間カシメ変形部とを軸周方向に位置をズラして形成した状態を示す要部側面図、（Ｂ）は（Ａ）の第１位置，第２位置の２個所におけるＸ₂−Ｘ₂矢視断面図、（Ｃ）は（Ａ）のＸ₃−Ｘ₃矢視断面図である。
【図１１】（Ａ）は本発明の第２実施形態の連結方法による中実軸を中空軸に挿入しようとする状態図、（Ｂ）は中実軸を中空軸に挿入した状態図、（Ｃ）は中空軸の第１位置及び第２位置にカシメ変形部を形成した状態図、（Ｄ）は中実軸と中空軸とを所定位置に設定し状態図、（Ｅ）は第３位置に中間カシメ変形部を形成して連結固定が完了した状態図である。
【図１２】（Ａ）は本発明の第２実施形態の連結方法によるカシメ変形部が外歯車状軸部に食い込む前の拡大した状態図、（Ｂ）は本発明の第２実施形態の連結方法によるカシメ変形部が外歯車状軸部に食い込み始めた拡大した状態図、（Ｃ）は本発明の第２実施形態の連結方法によるカシメ変形部が外歯車状軸部の第１位置及び第２位置への食い込みを完了したことを示す拡大した状態図、（Ｄ）は第３位置に中間カシメ変形部が食い込んだことを示す拡大した状態図である。
【符号の説明】
Ａ…中実軸
Ｂ…中空軸
１…外歯車状軸部
２…細径軸部
６…内歯車状部
７…カシメ変形部
８…中間カシメ変形部
Ｐ₁…第１位置
Ｐ₂…第２位置
Ｐ₃…第３位置[0001]
BACKGROUND OF THE INVENTION
The present invention is a type in which two shaft members are connected and fixed in a non-movable state by a caulking structure in a steering device. In particular, a large load is applied to form a caulking portion and firmly connect and fix both shaft members. The present invention relates to a steering shaft coupling method that can be performed without necessity, can reduce costs, and can suppress backlash in the axial direction and rotational direction.
[0002]
[Prior art]
Conventionally, in a steering shaft of a steering device, as means for connecting and fixing different shaft members in a non-movable state, they are firmly connected and fixed by fixing by welding or using a fixing tool such as a fixing pin. . Patent Document 1 discloses a structure in which shaft members are connected by caulking. This is composed of two member shafts, one of the two members is a solid shaft with male serrations and the other is a hollow shaft with female serrations, and the solid shaft is inserted into the hollow shaft Thus, it can be expanded and contracted in the axial direction.
[Patent Document 1]
JP-A-9-272447
Then, using the circumferential groove formed in the circumferential direction of the solid shaft, a radially inward recessed portion is formed at the outer position of the hollow shaft corresponding to the circumferential groove portion, and then the hollow shaft and the middle shaft are formed. The solid shaft is moved relative to each other, and the depressed portion is bitten by serrations on the outer periphery of the solid shaft. This intermediate shaft connection is a tangential depression with respect to the circular outer periphery of the solid shaft, and when subjected to an impact load exceeding a predetermined value, it is shortened in the axial direction and absorbed. Is.
[0004]
[Problems to be solved by the invention]
When welding, a fixing pin, or the like is used as a connecting and fixing means for a steering shaft composed of two members, there are the following drawbacks. That is, in welding, a thermal influence due to thermal distortion or the like occurs due to the configuration of the connecting shaft. In the case of connecting and fixing as a fixing pin, processing of a fitting hole and a member such as a fixing pin are required. Furthermore, if the fitting hole and the fixing pin are not firmly fitted or if the work accuracy is poor, the play in the axial direction and the rotational direction may occur and the steering feeling may be impaired. For this reason, since the fitting hole and the fixing pin reduce the clearance between the members by high-precision processing and reduce the occurrence of backlash, the cost increases. For these reasons, it is not preferable to use a connection fixing means such as welding and fixing pins.
[0005]
Moreover, what was disclosed by the said patent document 1 can move a superposition | polymerization location in the mutually stable state by applying the load more than predetermined. This absorbs an impact applied to the steering device, and does not firmly connect and fix the shaft members in a non-movable state.
[0006]
However, in order to connect and fix two shaft members in a non-movable state via caulking means, the connection strength of one caulking portion is insufficient and it is extremely weak against an impact in the axial direction, and the two shaft members move relative to each other. There is a risk. For this reason, a plurality of crimping parts are required. However, if the number of crimping parts increases, the shaft members interfere with each other through the crimping parts at the time of connecting work, a large load is required, the manufacturing machine becomes large, and the work is extremely difficult. Difficult and eventually expensive. An object of the present invention is to enable two shaft members in a steering shaft to be connected and fixed by caulking means with a relatively small load.
[0007]
[Means for Solving the Problems]
In view of the above, the inventor has intensively and intensively studied to solve the above-mentioned problems. As a result, the present invention has been described as a solid shaft having an outer gear-shaped shaft portion and a small diameter shaft portion formed from the shaft end side, A hollow shaft in which a hollow portion is formed, and the outer gear-like shaft portion and the small-diameter shaft portion of the solid shaft are inserted into the inner gear-like portion of the hollow shaft, and the inner gear-like portion of the hollow shaft The first and second positions are set at an appropriate interval shorter than the axial direction of the external gear-shaped shaft portion, the first position is positioned on the small-diameter shaft portion, and the second position is positioned on the small-diameter portion. A caulking deforming portion is formed in the shaft portion or the groove portion formed in the outer gear-like shaft portion and protrudes inward of the inner gear-like portion in the first and second positions, and then the solid shaft and the hollow The caulking deformed portion formed in the second position is separated from the shaft in the axial direction, and the groove portion formed in the small-diameter shaft portion or the external gear-shaped shaft portion. The caulking deformation part formed in the first position moves in the axial direction along the small diameter shaft part, and the caulking deformation part axially moves to the external gear-like shaft part. And a steering shaft coupling method characterized by fixing the rotation direction, and as a type in which the two shaft members are coupled and fixed in a non-movable state by a caulking structure, a caulking portion is formed in particular. A large load is not required to firmly connect and fix the shaft member, the cost can be reduced, and backlash in the axial direction and the rotational direction can be suppressed, thereby solving the above problems.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the connection method of the first embodiment of the present invention will be described with reference to the drawings. First, components will be described. As shown in FIG. 1A, the steering shaft is a member that constitutes the steering device, and is composed of a solid shaft A and a hollow shaft B. As shown in FIG. 2A, the solid shaft A has an external gear-shaped shaft portion 1 and a small-diameter shaft portion 2 formed in the axial direction from the shaft end portion. The outer gear-shaped shaft portion 1 has a cross section orthogonal to the axial direction formed in a substantially gear shape, and is specifically a serration or a spline. In the external gear shaft 1, grooves 3 are formed in the axial circumferential direction at appropriate positions along the axial direction. Further, the solid shaft A is formed with a flange portion 4 and can be connected to other members constituting the steering device [see FIG. 1 (B), FIG. 4 etc.].
[0009]
The hollow shaft B has an internal gear-like portion 6 formed on the inner peripheral side of a tubular shaft body 5. The internal gear-shaped portion 6 is configured to mesh with the external gear-shaped shaft portion 1 of the solid shaft A, and can transmit the rotational direction between the solid shaft A and the hollow shaft B to each other. The cross section orthogonal to the axial direction of the internal gear-shaped portion 6 is an internal gear shape, and specifically, it is a serration or a spline as with the external gear-shaped shaft portion 1.
[0010]
Its hollow shaft B, the first position P ₁ and the second position P ₂ is set along the shaft end in the axial direction, in its first position P ₁ and the second position P _2, FIG. 2 (A), the As shown in FIG. 4B and FIG. Actually, the first position P ₁ and the second position P ₂ are places where caulking deforming portions 7 for firm fixation are formed during the connecting and fixing operation with the solid shaft A [FIG. (See (B)) Before the assembly for connecting and fixing, as shown in FIG. 2 (A), the crimping deformation portion 7 is not formed at the first position P ₁ and the second position P ₂ . The solid shaft A and the hollow shaft B are connected and fixed in the axial direction, the other end side of the solid shaft A is connected to the handle side shaft via a joint, and the hollow shaft B is connected in the axial direction. The other end side is connected to the steering mechanism side of the front wheel.
[0011]
Next, a process for assembling and fixing the solid shaft A and the hollow shaft B as a connecting method according to the first embodiment will be described. First, the outer gear-shaped shaft portion 1 and the small-diameter shaft portion 2 of the solid shaft A are inserted on the inner peripheral side of the hollow shaft B. At this time, as shown in FIGS. 4A and 4B, the thin shaft portion 2 of the solid shaft A is inserted deeply into the shaft end portion of the hollow shaft B. Here, the first position P ₁ and the second position P ₂ are set to the hollow shaft B in the hollow shaft B. The first position P ₁ is set on the shaft end side, and the second position P ₂ is set on the back side in the axial direction with respect to the first position P ₁ .
[0012]
The first position P ₁ of the hollow shaft B corresponds to the position of the small-diameter shaft portion 2 of the solid shaft A, and the second position P ₂ corresponds to the position of the groove portion 3. In this state, caulking deformation portions 7 are formed at the first position P ₁ and the second position P ₂ of the hollow shaft B, respectively. A plurality of the crimping deformation portions 7 are formed at equal intervals in the respective circumferential directions of the first position P ₁ and the second position P ₂ of the hollow shaft B. Specifically, it is preferable that three places are formed at equal intervals [see FIG. 3A], but two places may be formed [see FIG. 3B], and only one place is formed. It may be formed (see FIG. 3C).
[0013]
The caulking deformation portion 7 is formed so as to protrude toward the inner peripheral side of the hollow shaft B [see FIG. 2 (C)]. Then, the hollow shaft B is moved in a direction away from the solid shaft A. Here, the caulking deformation portion 7 formed at the second position P ₂ moves from the position of the groove portion 3 to the external gear-shaped shaft portion 1, and the caulking deformation portion 7 keeps the external gear-shaped shaft portion 1 as it is. Toward the shaft end of the external gear shaft 1 [see FIG. 4C].
[0014]
On the other hand, the caulking deformed portion 7 formed at the first position P ₁ moves along the axial direction of the thin shaft portion 2, and when the caulking deformed portion 7 formed at the second position P ₂ reaches the shaft end. At the same time, it moves from the small diameter shaft portion 2 to the external gear shaft portion 1. Then, the caulking deformed portions 7 formed at the first position P ₁ and the second position P ₂ respectively contact the external gear shaft 1 in a strong pressure state so as to bite at an appropriate interval in the axial direction. Then, the connecting and fixing operation of the solid shaft A and the hollow shaft B is completed (see FIG. 4D).
[0015]
FIG. 5 is an enlarged view showing a process in which the caulking deformed portion 7 formed on the solid shaft A is connected so as to bite into the external gear shaft portion 1 of the solid shaft A. FIG. When moving with respect to the external gear-shaped shaft portion 1 of the caulking deformation portion 7, the caulking deformation portion 7 gradually bites into the external gear-shaped shaft portion 1 with respect to the axial radial direction of the external gear-shaped shaft portion 1. It can be transformed into a stable tightening state.
[0016]
Further, even if the caulking deformation portion 7 is provided at two locations of the first position P ₁ and the second position P ₂ , the caulking deformation portion 7 that bites into the external gear shaft 1 is formed at the second position P ₂ . It is from the crimping deformation | transformation part 7 formed, ie, the crimping deformation | transformation part 7 formed in the position corresponding to the groove part 3 of the external gear-shaped shaft part 1 (refer FIG. 5 (A)). The caulking deformation portion 7 formed at the first position P ₁ is moved from the small-diameter shaft portion 2 to the external gear when the caulking deformation portion 7 at the second position P ₂ is stable in the ironing state with respect to the external gear shaft portion 1. 5 enters the outer shaft 1 and bites the outer gear shaft 1 to complete the biting of the caulking deformed portion 7 at the first position P ₁ and the second position P _{2 on} the outer gear shaft 1 [FIG. B) and (C)].
[0017]
The caulking deformed portion 7 at the first position P ₁ formed on the small shaft portion 2 side of the solid shaft A is in the axial radial direction of the caulking deformed portion 7 that bites into the outer gear shaft 1 first. The direction of caulking of the outer gear-shaped shaft portion 1 is improved while the staking state of the direction is stabilized and the movement of the caulking deformation portion 7 at the second position P ₂ with respect to the outer gear-shaped shaft portion 1 is guided. It can be ensured, and the biting state of the caulking deformation part 7 can be made stable and strong. The thin shaft portion 2 of the solid shaft A not only forms the caulking deformed portion 7 of the hollow shaft B, but also serves as a fuse portion of the steering shaft. It is possible to prevent the radial shaft portion 2 from being broken, interrupting the impact energy, and transmitting the primary impact to the driver.
[0018]
By providing the hollow shaft B with the caulking deformation portion 7 at an appropriate distance in the axial direction at two locations, the first position P ₁ and the second position P ₂ , the strength against the bending force at the connecting portion is increased. Can be secured. Further, at the time of working, the two caulking deforming portions 7 do not bite and move the solid shaft A to the external gear shaft portion 1 at the same time, so that the hollow shaft B is pulled away from the solid shaft A. Even when moved and connected and fixed, it is possible to avoid chamfering due to a large load and to prevent excessive deformation of the workpiece due to the heavy load.
[0019]
FIG. 6 is a type in which the groove portion 3 is not formed in the external gear-like shaft portion 1 of the solid shaft A, and shows a connecting step. In this case, the first position P ₁ and the second position P ₂ are set at two places on the small-diameter shaft portion, and the crimping deformation portion 7 is formed (see FIG. 6B). Then, the hollow shaft B is pulled out from the solid shaft A in the same manner as described above, and the caulking deformed portion 7 is bitten on the external gear-shaped shaft portion 1 (see FIGS. 6C and 6D).
[0020]
Next, a connection method according to the second embodiment of the present invention will be described. The structure of the steering shaft of the component will be described with reference to FIGS. First, as described above, in the constituent members in the connection method of the first embodiment, the caulking deformed portion 7 at the first position P ₁ and the second position P ₂ is the external gear-shaped shaft portion 1 of the solid shaft A. And the inner gear-like portion 6 of the hollow shaft B are engaged with each other in a pressed state by the caulking deformation portion 7 projecting inward of the hollow shaft B and the outer gear-like shaft portion 1 by relative movement in the axial direction. It is a thing.
[0021]
As shown in FIGS. 7 and 10 and the like, the components in the connecting method according to the second embodiment are caulking deformed portions 7, 7,... Provided at the first position P ₁ and the second position P ₂ , respectively. In addition, the caulking deformation portion 7 is provided at the newly set third position P ₃ . The third position P ₃ is set at a predetermined position between the first position P ₁ and the second position P ₂ set on the hollow shaft B.
[0022]
Specifically, the outer gear-like shaft portion 1 and the small-diameter shaft portion 2 of the solid shaft A are inserted on the inner peripheral side of the hollow shaft B, and the first position P ₁ and the second position are respectively inserted into the hollow shaft B. The position P ₂ is set, and the crimping deformation portions 7 are formed at the first position P ₁ and the second position P ₂ , respectively. As shown in FIGS. 7 and 10, the third position P ₃ is between the first position P ₁ and the second position P _{2 in} the crimping deformed portions 7 and 7 in the axial direction, and is hollow. A position corresponding to the axial circumferential groove 3 in the middle of the external gear-like shaft 1 of the solid shaft A connected in a fixed state with the shaft B is a third position P ₃ .
[0023]
An intermediate crimping deformation portion 8 is also formed at the third position P ₃ . The intermediate crimping deformation portion 8 has substantially the same shape as the crimping deformation portion 7 formed at the first position P ₁ and the second position P ₂ . The intermediate crimping deformation portion 8 formed at the third position P ₃ is in a state of being engaged with the groove portion 3 of the hollow shaft B as shown in FIGS. 9 (A) and 9 (B). In addition, normally, as shown in FIG. 9C, a plurality of the intermediate crimping deformation portions 8 are formed along the axial direction of the hollow shaft B.
[0024]
When a plurality of intermediate crimping deformation portions 8, 8,... Are formed in this way, it is preferable that they are formed at equal intervals in the axial circumferential direction, but it is not always necessary to have equal intervals. Further, if necessary, only two intermediate caulking deformable portions 8 may be formed in the axial circumferential direction (see FIG. 9D). Further, only one intermediate crimping deformation portion 8 may be formed in the axial circumferential direction (see FIG. 9E). Further, the state in which the intermediate caulking deformed portion 8 formed at the third position P ₃ is engaged with the groove portion 3 is that the groove portion 3 and the intermediate caulking deformed portion 8 are at least one as shown in FIG. Further, the intermediate crimping deformed portion 8 may be engaged with the groove portion 3 and a pressing state may be applied. Moreover, although the intermediate crimping deformation | transformation part 8 penetrates into the groove part 3, the intermediate crimping deformation part 8 and the bottom of the groove part 3 may be in a non-contact state.
[0025]
Further, when a plurality of intermediate crimping deformation portions 8 are formed along the axial direction of the hollow shaft B, as shown in FIG. 10 (A), the first position P ₁ and the second position P ₂ It is preferable that the crimping deformation portion 7 is appropriately deviated from the position in the axial circumferential direction. That is, the first position P ₁ and the second position P ₂ in the crimping deformation portions 7, ... may have been formed at regular intervals along the axial circumferential direction, the axial peripheral direction of the third position P ₃ The intermediate caulking deformation portions 8, 8,... Formed along the axial direction are formed so as to be positioned between the caulking deformation portions 7, 7 adjacent to each other in the axial circumferential direction.
[0026]
For example, the a first and second position P ₂ a reference, if a plurality of crimping deformation portions 7 along the axial circumferential direction, ... are formed at equal intervals in three places, Jikushu direction respectively The caulking deformation portions 7 and 7 adjacent to each other are 120 degrees with respect to the diametrical center of the hollow shaft B [FIG. 10B shows X at the first position P ₁ and the second position P ₂ . ₂ -X ₂ arrow sectional view]. When the intermediate caulking deformation portion 8 formed in the axial peripheral direction of the third position P ₃ is formed by setting so that the intermediate position of the crimping deformation portions 7 adjacent to the axis circumferential direction, The angle in the axial circumferential direction between the crimping deformation portion 7 and the intermediate crimping deformation portion 8 is formed at a position shifted by approximately 60 degrees (see FIG. 10C).
[0027]
Of course, as described above, the caulking deformation portion 7 and the intermediate caulking deformation portion 8 are not limited to be shifted by approximately 60 degrees in the axial circumferential direction, and may be set at an appropriate angle. In addition, it is preferable that the caulking deformation portion 7 at the first position P ₁ and the second position P ₂ and the intermediate caulking deformation portion 8 at the third position P ₃ are shifted in the axial circumferential direction. Instead, the caulking deformation portion 7 and the intermediate caulking deformation portion 8 may be formed at the same position along the axial direction. Due to the engagement between the intermediate caulking deformed portion 8 at the third position P ₃ of the hollow shaft B and the groove portion 3 of the solid shaft A, the coupling and fixing is stronger than the connecting and fixing state in which only the caulking deformed portion 7 is engaged. Can be obtained.
[0028]
Next, the connecting method or assembling method of the second embodiment, that is, the assembling process of connecting and fixing the solid shaft A and the hollow shaft B will be described. This process is almost the same as the previous embodiment, but differs in the final stage. First, as shown in FIGS. 11A and 11B, the outer gear-like shaft portion 1 and the small-diameter shaft portion 2 of the solid shaft A are inserted deeply into the inner peripheral side of the hollow shaft B so that the hollow shaft A first position P ₁ and a second position P ₂ are set on the shaft B as the hollow shaft B. At this time, the first position P ₁ is set on the axial end side, and the second position P ₂ is set on the far side in the axial direction from the first position P ₁ .
[0029]
As shown in FIG. 11C, the first position P ₁ of the hollow shaft B corresponds to the position of the small-diameter shaft portion 2 of the solid shaft A, and the second position P ₂ corresponds to the groove portion 3. Correspond to the position of. In this state, caulking deformation portions 7 are formed at the first position P ₁ and the second position P ₂ of the hollow shaft B, respectively. A plurality of the crimping deformation portions 7 are formed at equal intervals in the respective circumferential directions of the first position P ₁ and the second position P ₂ of the hollow shaft B.
[0030]
The caulking deformation portion 7 is formed so as to protrude toward the inner peripheral side of the hollow shaft B, and moves the hollow shaft B in a direction away from the solid shaft A. Here, as shown in FIG. 11 (D), the caulking deformed portion 7 formed at the second position P ₂ moves from the position of the groove portion 3 to the external gear-shaped shaft portion 1, and the caulking deforming portion 7 is moved as it is. The external gear-shaped shaft portion 1 is moved toward the shaft end side of the external gear-shaped shaft portion 1 in a squeezed manner.
[0031]
On the other hand, the caulking deformed portion 7 formed at the first position P ₁ moves along the axial direction of the thin shaft portion 2, and when the caulking deformed portion 7 formed at the second position P ₂ reaches the shaft end. At the same time, it moves from the small-diameter shaft portion 2 to the external gear shaft portion 1 and the crimping deformation portions 7 formed at the first position P ₁ and the second position P ₂ respectively move the external gear shaft portion 1 in the axial direction. At an appropriate interval, they come into contact with each other in a strong pressure state (see FIG. 11D). Next, when the intermediate caulking deformed portion 8 is formed at the third position P ₃ of the hollow shaft B, the intermediate caulking deformed portion 8 engages in a state of entering the groove portion 3 of the solid shaft A [FIG. (See (E)). Thereby, the coupling and fixing of the solid shaft A and the hollow shaft B are completed.
[0032]
FIG. 12 is an enlarged view of a main part showing steps in the second embodiment. In FIGS. 12A to 12C, the hollow shaft B is caulked to the first position P ₁ and the second position P _2. In a state where the portion 7 is formed, the solid shaft A and the hollow shaft B are set at predetermined positions, and in this state, the intermediate crimping deformed portion 8 is formed at the third position P ₃ in FIG. Thus, the intermediate crimping deformation portion 8 is in a state of biting into the groove portion 3.
[0033]
【The invention's effect】
Next, the invention of claim 1 includes a solid shaft A in which the outer gear-shaped shaft portion 1 and the small-diameter shaft portion 2 are formed from the shaft end side, and a hollow shaft B in which the inner gear-shaped portion 6 is formed. Thus, the external gear-shaped shaft portion 1 and the small-diameter shaft portion 2 of the solid shaft A are inserted into the internal gear-shaped portion 6 of the hollow shaft B, and the external gear is inserted into the internal gear-shaped portion 6 of the hollow shaft B. The first and second positions are set at an appropriate interval shorter than the axial direction of the shaft 1, the first position P ₁ is positioned on the small-diameter shaft 2, and the second position P ₂ is A caulking deformation portion 7 is formed in the groove portion 3 formed in the small-diameter shaft portion 2 or the external gear-like shaft portion 1 and protrudes inward of the internal gear-like portion 6 at the first and second positions. Next, the solid shaft A and the hollow shaft B are pulled apart in the axial direction, and a caulking deformed portion 7 formed at the second position P ₂ is formed on the small-diameter shaft portion 2 or the external gear-shaped shaft portion 1. Before Groove 3 engages with the external gear shaped shaft portion 1 from the position, then moving the crimping deformation portion 7 is thin shaft portion 2 formed in the first position P ₁ in the axial direction, the caulking deformation portion 7 Is a method of connecting the steering shaft by fixing the axial direction and the rotational direction to the external gear shaft 1, so that the connecting and fixing operation of the solid shaft A and the hollow shaft B can be performed efficiently, It can be set as firm connection fixation.
[0034]
The above effect will be described in detail. When the caulking deformed portion 7 is formed at the first position P ₁ and the second position P ₂ , the small diameter shaft portion 2 of the hollow shaft B is used. It can be easily formed without receiving any resistance when the caulking deformed portion 7 is formed from the portion 1. Further, when the hollow shaft B is moved away from the solid shaft A after the crimping deformed portion 7 is formed, the caulking deformed portion 7 formed at the second position P ₂ is moved to the external gear-shaped shaft portion 1. After the caulking deformed portion 7 at the second position P ₂ approaches the shaft end position of the external gear shaft ₁ , the caulking deformed portion 7 at the first position P ₁ moves to the external gear shaft 1.
[0035]
Therefore, the caulking deformation portions 7 formed on the hollow shaft B at the first position P ₁ and the second position P ₂ , respectively, simultaneously bite and move the solid shaft A to the external gear shaft portion 1. Therefore, when the hollow shaft B is moved away from the solid shaft A and the caulking deformed portion 7 is used to fix the biting state at both ends in the axial direction of the external gear-shaped shaft portion 1, it is large. It is not necessary to carry out chamfering with a load, and therefore unnecessary deformation to the solid shaft A and the hollow shaft B due to heavy load processing can be prevented.
[0036]
The caulking deformed portion 7 at the first position P ₁ formed on the small shaft portion 2 side of the solid shaft A is in the axial radial direction of the caulking deformed portion 7 that bites into the outer gear shaft 1 first. The direction of caulking of the outer gear-shaped shaft portion 1 is improved while the staking state of the direction is stabilized and the movement of the caulking deformation portion 7 at the second position P ₂ with respect to the outer gear-shaped shaft portion 1 is guided. It can be ensured, and the biting state of the caulking deformation part 7 can be secured stably.
[0037]
Further, in detail, the caulking deformation portion 7 formed at the second position P ₂ when the hollow shaft B is moved in the direction away from the solid shaft A is shaped like an external gear from the position of the groove portion 3. It moves to the shaft portion 1, and the caulking deformed portion 7 moves toward the shaft end side of the outer gear-shaped shaft portion 1 as it squeezes the outer gear-shaped shaft portion 1. Since the groove portion 3 is formed in the region of the external gear-shaped shaft portion 1, the caulking deformation portion 7 formed corresponding to the groove portion 3 extends along the external gear-shaped shaft portion 1. Thus, the distance to reach the axial end of 1 can be reduced, and the working efficiency is improved.
[0038]
A groove portion 3 is formed along the circumferential direction at an appropriate position near the small-diameter shaft portion 2 side of the external gear-shaped shaft portion 1, and the second position P ₂ coincides with the position of the groove portion 3. By forming the caulking deformed portion 7, the connecting and fixing operation of the solid shaft A and the hollow shaft B can be performed more efficiently. The thin shaft portion 2 of the solid shaft A can also serve as a fuse portion of the steering shaft. That is, in the impact at the time of the collision, the small-diameter shaft portion 2 is broken, and the impact energy is cut off at this portion, so that the primary impact can be prevented from being transmitted to the driver.
[0039]
The invention of claim 2 includes an external gear-shaped shaft portion 1 from the shaft end side, a groove portion 3 formed substantially in the middle of the external gear-shaped shaft portion 1 in the axial circumferential direction, and the shaft of the external gear-shaped shaft portion 1. It consists of a solid shaft A composed of a small-diameter shaft portion 2 formed at the end and a hollow shaft B formed with an internal gear-shaped portion 6, and has a small diameter relative to the external gear-shaped shaft portion 1 of the solid shaft A. The shaft portion 2 is inserted into the internal gear-shaped portion 6 of the hollow shaft B, and the internal gear-shaped portion 6 of the hollow shaft B is first spaced at an appropriate interval shorter than the axial direction of the external gear-shaped shaft portion 1. A position P ₁ and a second position P ₂ are set, the first position P ₁ is positioned on the small-diameter shaft portion 2, and the second position P ₂ is positioned on the small-diameter shaft portion 2 or the external gear-shaped shaft portion 1. A caulking deformed portion 7 is formed in the groove portion 3 formed and protrudes inward of the internal gear-like portion 6 at the first position P ₁ and the second position P ₂ , and then the solid shaft A and the hollow shaft Pull B in the axial direction And the second position P ₂ crimping deformation portion 7 formed engages with the external gear shaped shaft portion 1 from the position of the small-diameter shaft portion 2 or the groove 3, and then formed on the first position P ₁ The crimped deformed portion 7 moves the small-diameter shaft portion 2 in the axial direction, and fixes the axial direction and the rotational direction in the pressed state to the external gear shaft portion 1, and the first position P ₁ and the second position P thereof. at _second intermediate third position P ₃ is set, the third position P ₃ is located in the groove 3 of the outer toothed shaft portion 1, enters the internal toothed portion 6 in the groove 3 to the hollow shaft B In this way, the solid shaft A and the hollow shaft B are connected more firmly by the intermediate shaft crimping portion 8 being formed and the steering shaft connecting method being engaged with the external gear shaft portion 1 as described above. It can be fixed, and the connecting and fixing work can be performed very efficiently.
[0040]
In detail, the solid shaft A is once inserted deeply into the hollow shaft B, and the caulking deformed portions 7 are formed at the first position P ₁ and the second position P ₂ respectively. The caulking deformation portion 7 formed at the second position P ₂ when moving in the direction away from the solid shaft A moves from the position of the groove portion 3 to the external gear shaft portion 1, and the groove portion 3 Is formed at a substantially intermediate position of the external gear shaft 1, the distance at which the caulking deformed portion 7 reaches the predetermined position of the external gear shaft 1 from the groove 3 may be short.
[0041]
Further, after setting the solid shaft A and the hollow shaft B to predetermined positions, the intermediate crimping deformed portion 8 is formed at the third position P _{3, so} that the intermediate crimping deformed portion 8 is formed on the inner periphery of the hollow shaft B. It is formed so as to enter into the groove portion 3 in the process of bulging to the side, can be formed with relatively little resistance, and the solid shaft A and the hollow shaft B are connected in an axial direction that is extremely strong Can be.
[0042]
The first position P ₁ and the second position P ₂ of the caulking deformation portions 7, ... after uniformly provided at a plurality of locations to Jikushu direction (e.g. three), an intermediate caulking of the third position P ₃ The deforming portions 8, 8,... Are evenly provided at a plurality of locations (for example, three locations) along the axial direction, so that the caulking deformation portions adjacent to each other in the axial direction of the first position P ₁ and the second position P ₂ are provided. The intermediate caulking deformed portions 8, 8,... Are located in a portion that is not caulked and deformed between 7, 7, that is, an uncrimped portion. As a result, the caulking deformation part 7 and the intermediate caulking deformation part 8 exist at a distance from each other in the axial direction and the axial circumferential direction, so that the distortion of the caulking molding does not reach each other and the strength of the hollow shaft B Will not deteriorate. Moreover, the hollow shaft B on which the crimping deformation portion 7 and the intermediate crimping deformation portion 8 are formed can be provided with a large number of crimping locations in the circumferential direction of the shaft, even if the shaft diameter is not large. Miniaturization can be realized, and the connection structure can be stabilized without impairing the strength of connection fixing by caulking.
[Brief description of the drawings]
FIG. 1A is a side view showing an entire steering shaft according to a connecting method of a first embodiment of the present invention, and FIG. 1B is an enlarged view of a main part in a partial cross section of FIG.
2A is a perspective view of a main part of a solid shaft and a hollow shaft according to the connection method of the first embodiment of the present invention, FIG. 2B is a perspective view of a connection state of the solid shaft and the hollow shaft, and FIG. ) Is an enlarged perspective view of the caulking deformed portion of the hollow shaft.
3A is a cross-sectional view of an essential part showing a type in which the number of crimping deformation portions according to the connection method of the first embodiment of the present invention is three in the circumferential direction, and FIG. 3B is a diagram showing the number of crimping deformation portions. The principal part sectional view which shows the type made into two in the circumferential direction, (C) is principal part sectional drawing which shows the type which made the number of crimping deformation parts one in the circumferential direction.
4A is a state diagram in which a solid shaft is to be inserted into a hollow shaft according to the connection method of the first embodiment of the present invention, FIG. 4B is a state diagram in which the solid shaft is inserted into the hollow shaft, (C) is a state diagram in which caulking deformation portions are formed at the first position and the second position of the hollow shaft, and (D) is a state diagram in which the coupling and fixing are completed.
FIG. 5A is an enlarged state diagram before the caulking deformation portion bites into the external gear shaft portion according to the connecting method of the first embodiment of the present invention, and FIG. 5B is the caulking deformation portion of the external gear shaft portion. (C) is an enlarged state diagram in which the connection and fixing are completed.
6 (A), (B), (C), and (D) are process diagrams of a type in which no groove is formed in the external gear shaft portion according to the connecting method of the first embodiment of the present invention.
7A is a perspective view of a main part of a solid shaft and a hollow shaft according to the connection method of the second embodiment of the present invention, and FIG. 7B is a perspective view of the solid shaft and the hollow shaft according to the connection method of the second embodiment. It is a perspective view of a connection state.
FIG. 8 is an enlarged cross-sectional perspective view of a caulking deformed portion and an intermediate caulking deformed portion of a hollow shaft according to the connecting method of the second embodiment of the present invention.
9A is an enlarged vertical side view of a portion of an intermediate caulking deformed portion of a hollow shaft according to the connecting method of the second embodiment of the present invention, and FIG. 9B is a cross-sectional view taken along arrow X ₁ -X _{1 in} FIG. (C) is a longitudinal front view in which three intermediate caulking deformation portions are formed in the axial circumferential direction, (D) is a vertical front view in which two intermediate caulking deformation portions are formed in the axial circumferential direction, and (E) is an intermediate caulking. It is the vertical front view which formed the deformation | transformation part in one place in the axial circumferential direction.
FIG. 10A is a side view of an essential part showing a state in which a caulking deformation part and an intermediate caulking deformation part are formed by shifting their positions in the axial circumferential direction by the connecting method according to the second embodiment of the present invention; ) Is a cross-sectional view taken along the arrow line X ₂ -X _{2 at} two positions of the first position and the second position of (A), and (C) is a cross-sectional view taken along the line X ₃ -X ₃ of (A).
FIG. 11A is a state diagram in which a solid shaft is to be inserted into a hollow shaft according to the connecting method of the second embodiment of the present invention, and FIG. 11B is a state diagram in which the solid shaft is inserted into the hollow shaft. (C) is a state diagram in which caulking deformation portions are formed at the first position and the second position of the hollow shaft, (D) is a state diagram in which the solid shaft and the hollow shaft are set at predetermined positions, and (E) is a third position. FIG. 6 is a state diagram in which the intermediate crimping deformed portion is formed to complete the connection and fixation.
12A is an enlarged state diagram before the caulking deformed portion bites into the external gear shaft portion according to the connecting method of the second embodiment of the present invention, and FIG. 12B is the connection state of the second embodiment of the present invention. FIG. 8C is an enlarged state diagram in which the caulking deformed portion by the method starts to bite into the external gear-shaped shaft portion, and FIG. FIG. 4D is an enlarged state diagram showing that the biting into the second position has been completed, and FIG. 4D is an enlarged state diagram showing that the intermediate caulking deformed portion has bitten into the third position.
[Explanation of symbols]
A ... Solid shaft B ... hollow shaft 1 ... external gear shaped shank 2 ... small diameter shaft portion 6 ... internal gear shaped portion 7 ... caulking deformation portion 8 ... intermediate caulking deformation portion P ₁ ... the first position P ₂ ... second Position P ₃ ... Third position

Claims

A solid shaft formed with an outer gear-shaped shaft portion and a small-diameter shaft portion from the shaft end side, and a hollow shaft formed with an internal gear-shaped portion, and the outer gear-shaped shaft portion and the small diameter of the solid shaft A shaft portion is inserted into the internal gear-shaped portion of the hollow shaft, and the first and second positions are spaced from the internal gear-shaped portion of the hollow shaft at an appropriate interval shorter than the axial direction of the external gear-shaped shaft portion. The first position is positioned at the small-diameter shaft portion, the second position is positioned at a groove formed in the small-diameter shaft portion or the external gear-shaped shaft portion, and the first and second positions are set. A caulking deformation portion protruding inward of the internal gear-shaped portion is formed, and then the solid shaft and the hollow shaft are separated from each other in the axial direction, and the caulking deformation portion formed at the second position is the small diameter shaft portion. or engages the external gear shaped shaft portion from the position of the groove formed in the outer toothed shaft portion, then crimping deformation portion formed in the first position The diameter shaft portion to move in the axial direction, the coupling method of a steering shaft caulking deformation portion is characterized by being obtained by fixing the axial and rotational directions on the outer toothed shaft portion.

An external gear-shaped shaft portion from the shaft end side, a groove portion formed substantially in the middle of the external gear-shaped shaft portion and in the axial circumferential direction, and a small-diameter shaft portion formed at the shaft end of the external gear-shaped shaft portion A solid shaft and a hollow shaft formed with an internal gear-shaped portion, and the external gear-shaped shaft portion and the small-diameter shaft portion of the solid shaft are inserted into the internal gear-shaped portion of the hollow shaft, A first position and a second position are set at an appropriate interval shorter than the axial direction of the outer gear-shaped shaft portion on the inner gear-shaped portion of the hollow shaft, and the first position is positioned on the small-diameter shaft portion, The second position is positioned in a groove formed in the small-diameter shaft portion or the external gear-shaped shaft portion, and a caulking deformation portion that protrudes inward of the internal gear-shaped portion is formed in the first position and the second position, Next, the solid shaft and the hollow shaft are separated from each other in the axial direction, and the caulking deformed portion formed at the second position is shaped like an external gear from the position of the small diameter shaft portion or the groove portion. The caulking deformed portion formed at the first position moves the small-diameter shaft portion in the axial direction, and fixes the axial direction and the rotational direction in the pressed state to the external gear-like shaft portion, is the third position is set in the middle of the first position and the second position, the third position is located in the groove of the outer toothed shaft portion, the intermediate so as to enter the internal toothed portion in the groove in the hollow shaft A method of connecting a steering shaft, wherein a crimping deformation portion is formed and engaged with the external gear shaft portion.