JP3968958B2

JP3968958B2 - Auto tensioner

Info

Publication number: JP3968958B2
Application number: JP2000185753A
Authority: JP
Inventors: 官治川崎
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2000-06-21
Filing date: 2000-06-21
Publication date: 2007-08-29
Anticipated expiration: 2020-06-21
Also published as: JP2002005253A

Description

【０００１】
【発明の属する技術分野】
本発明は、ベルト駆動機構のベルトの張力を自動的に適度に保つためのオートテンショナに関する。
【０００２】
【従来の技術】
一般に、オートテンショナは、環境の温度変化や経時的な伸縮変化等によって発生するベルトの張力変動に応じてテンションプーリの動きを許容しつつ、ベルトからの振動や衝撃を減衰するようにテンションプーリの動きを規制する機能を有した構造になっている。
【０００３】
このような機能を実現するために、テンションプーリ支持用のアームのボス部の前側端面と、アーム支持用の支軸の前端に一体的に取付けられる押え板（ガイド板）との隙間に環状の摩擦板を挟み、ねじりコイルばねの伸張復元力により前記摩擦板をボス部と押え板とに圧接させるようにしている。
【０００４】
【発明が解決しようとする課題】
ところで、オートテンショナの軽量化のために、押え板には薄い平板が用いられてきた。しかし、この押え板には、ねじりコイルばねの伸張復元力が摩擦板を介して継続的に働いている。
【０００５】
このため、押え板に、その外周部が反り上がるような変形が発生して摩擦板の面圧が不均一になってしまい、摩擦板に偏摩耗が発生したり、あるいは押え板に対する摩擦板の摺動が不安定になって、アームが振動してしまうという不都合があった。
【０００６】
このような不都合を解消するには、押え板の厚みを厚くしてその剛性を高める構成とすることが考えられるが、そうすると、オートテンショナの軽量化を図れなくなってしまうという課題が生じる。
【０００７】
そこで本発明は、上記課題を解決し得るオートテンショナの提供を目的とする。
【０００８】
【課題を解決するための手段】
本発明の請求項１に係るオートテンショナは、ベルト駆動機構のベルトの張力を自動的に適度に保つためのオートテンショナであって、固定の支軸部材と、この支軸部材に対しボス部が回動可能に嵌合支持されたアームと、このアームを支軸部材回りに一定方向に回動付勢するためのばねと、アームの先端部に回転可能に枢支されるテンションプーリと、前記ボス部の軸心方向端面に形成した凹部に配置されてアームに対して回動抵抗を与えるための摩擦板と、前記支軸部材の軸心方向端面側に取付けられるとともに前記摩擦板をボス部の軸心方向端面に押圧して挟持する平坦な押え面を有した押え板とを備え、この押え板の外周縁を折曲させて、この折り曲げ部により、摩擦板の反対側である開放された外側に向けて軸方向に延び、かつ押え板の周方向に連続する環状の補強部を形成して、押え板の断面係数を増加させたことを特徴とする。
本発明の請求項２に係るオートテンショナは、ベルト駆動機構のベルトの張力を自動的に適度に保つためのオートテンショナであって、固定の支軸部材と、この支軸部材に対しボス部が回動可能に嵌合支持されたアームと、このアームを支軸部材回りに一定方向に回動付勢するためのばねと、アームの先端部に回転可能に枢支されるテンションプーリと、前記ボス部の軸心方向端面に形成した凹部に配置されてアームに対して回動抵抗を与えるための摩擦板と、前記支軸部材の軸心方向端面側に取付けられるとともに前記摩擦板をボス部の軸心方向端面に押圧して挟持する平坦な押え面を有した押え板とを備え、この押え板の押え面を折曲させて、この折曲げ部により、摩擦板の反対側である開放された外側に向けて軸方向に延びるように突出し、かつ押え板の周方向に連続する環状の補強部を形成して押え板の断面係数を増加させ、前記折曲げ部は、突出して折り曲げられることにより径方向で対向する面同士が互いに密接していることを特徴とする。
本発明の請求項３に係るオートテンショナは、ベルト駆動機構のベルトの張力を自動的に適度に保つためのオートテンショナであって、固定の支軸部材と、この支軸部材に対しボス部が回動可能に嵌合支持されたアームと、このアームを支軸部材回りに一定方向に回動付勢するためのばねと、アームの先端部に回転可能に枢支されるテンションプーリと、前記ボス部の軸心方向端面に形成した凹部に配置されてアームに対して回動抵抗を与えるための摩擦板と、前記支軸部材の軸心方向端面側に取付けられるとともに前記摩擦板をボス部の軸心方向端面に押圧して挟持する平坦な押え面を有した押え板とを備え、この押え板の外周縁を折曲させて、この折り曲げ部により、摩擦板の反対側である開放された外側に向けて軸方向に延び、かつ押え板の周方向に連続する環状の補強部を形成するとともに、前記押え板の押え面を折曲させて、この折曲げ部により、摩擦板の反対側である開放された外側に向けて軸方向に延びるように突出し、かつ押え板の周方向に連続する環状の補強部を形成して、前記両補強部により押え板の断面係数を増加させ、前記押え板の押え面に形成した折曲げ部は、突出して折り曲げられることにより径方向で対向する面同士が互いに密接していることを特徴とする。
【０００９】
上記構成において、ベルトの張力が減少した場合、ばねの復元力により、アームおよびテンションプーリが傾動してベルトの張力が一定になるよう調節され、ベルトの張力が増加した場合、ばねの復元力に抗してアームおよびテンションプーリが反対方向に傾動して、ベルトの張力が一定になるよう調節され、さらに、ベルトから激しい振動や衝撃が加わった場合、テンションプーリを支持しているアームのボス部にその振動や衝撃が伝わることになる。このとき、ばねの伸張復元力によりボス部が摩擦板に押付けられて摩擦抵抗が発生しているので、振動や衝撃が吸収、減衰され、アーム部材の不要な揺動を抑制し、これにより、テンションプーリの変位が抑えられ、ベルトに対するテンションが一定に保たれる。
【００１１】
上記構成によれば、押え板の外周部に、ばねの伸張復元力が、摩擦板を介して継続的に働いた状態にあっても、補強部によって押え板の外周縁部が反るような変形が抑えられ、したがって、摩擦板の偏摩耗を防止して摩擦板の面圧を継続的に均一に維持し、押え板に対する摩擦板の摺動動作を安定させてベルトに対して常に安定したテンションを付与する。
【００１２】
【発明の実施の形態】
以下、本発明の実施の形態を、図１ないし図３に基づいて説明する。図1は本発明の実施の形態に係るオートテンショナの正面図、図２は図1におけるＹ−Ｙ線矢視図、図3は摩擦板押え部材の単体斜視図である。
【００１３】
本発明の実施の形態に係るオートテンショナ１は、図示しないベルト駆動機構の所定の場所に、ボルト２によって取付け片１８が固定される支軸部材５と、この支軸部材５の円錐台状のアーム支持部６に対し、環状の基端ボス部７がブッシュ８を介して回動可能に嵌合支持されたアーム部材９と、このアーム部材９の先端部のプーリ支持部１０に、転がり軸受１１および支軸部材５の軸心Ｃ方向に沿って配置されたボルト３を介して回転可能に支持されるテンションプーリ（板金プレス加工によって製作されている）１２とを備えている。
【００１４】
前記支軸部材５は、アルミニウム合金などを用いたダイカスト成形により製作され、前記アーム支持部６と外筒部１３とを備え、この外筒部１３は、アーム支持部６の基端側から径方向外向きに延びるとともに自由端側に延びてアーム支持部６の外周を囲むように形成され、この支軸部材５における、アーム支持部６の外周面の形状は、成形金型の抜き勾配に対応している。
【００１５】
前記アーム部材９を支軸部材５回りに一定方向に回動付勢するためのねじりコイルバネ１４が設けられ、このねじりコイルバネ１４は、前記アーム支持部６の外周面およびアーム部材９の基端ボス部７の外周面、支軸部材５の外筒部１３の内周面との間に形成される環状空間５Ａに、それぞれの面に対して非接触で、かつねじり圧縮された状態で配置されている。
【００１６】
このねじりコイルバネ１４の両端側には、支軸部材５の径方向外向きに屈曲された屈曲部１５ａ，１５ｂが一体的に形成されており、これらの屈曲部１５ａ，１５ｂが支軸部材５の底部に形成されたスリット状の切欠き１６と、アーム部材９の基端ボス部７に形成されたスリット状の切欠き１７とにそれぞれ係止されている。
【００１７】
そして、このねじりコイルバネ１４は、そのねじり復元力によってアーム部材９を、軸心Ｃ回りに図1の反時計方向に付勢しており、前記軸心Ｃ方向の伸張復元力によりアーム部材９の基端ボス部７を後述の摩擦板２０に押付けて基端ボス部７に対して摩擦抵抗を付与する機能を有している。
【００１８】
前記摩擦板２０は、基端ボス部７の軸心Ｃ方向前端面に形成した凹部２１に配置されて、支軸部材５におけるアーム支持部６の先端側にボルト１９により固定される環状の摩擦板押え部材２２の平坦押え面２２ａとの間に挟まれた状態で保持されている。
【００１９】
そして、摩擦板２０は、ねじりコイルバネ１４の伸張復元力により基端ボス部７の端面と摩擦板押え部材２２とに対して所定圧力で押付けられて、基端ボス部７に対して回動抵抗を付与している。
【００２０】
なお、前記摩擦板２０は、例えばポリエーテルエーテルケトン（ＰＥＥＫ）などのポリアミド樹脂、クラッチフェーシング材、ブレーキライニング材あるいはブレーキパッド材などで形成されている。
【００２１】
また、摩擦板２０が周方向に回って適正位置からずれてしまうのを防止するために、図示しないが、基端ボス部７の端面の一箇所に径方向外方に突出する突起を設ける一方で、摩擦板２０の中心孔の円周上の一箇所に突起に係合する凹部を形成し、これらの係合により、摩擦板２０を不動に拘束させている。
【００２２】
前記摩擦板押え部材２２は、中央に嵌合孔３０が形成され、この嵌合孔３０が、基端ボス部７の前端面中央部に形成された段付き凸部３１に嵌合支持され、この摩擦板押え部材２２に、前記軸心Ｃ方向に沿って摩擦板２０の反対側（外方）に向けて突出するとともに、摩擦板押え部材２２の周方向に沿うフランジ状の補強部２５がプレス加工により一体形成され、この補強部２５は、摩擦板押え部材２２の外周縁を折曲させて環状に形成している。このような補強部２５を形成することにより、摩擦板押え部材２２の断面係数（剛性）を増加させている。
【００２３】
本発明の実施の形態におけるオートテンショナ１では、ベルトＢの張力変動に応じたテンションプーリ１２の動きを許容しつつ、ベルトＢからの振動や衝撃を減衰するようにテンションプーリ１２の動きを規制する。
【００２４】
例えば、ベルトＢの張力が緩やかに減少した場合、ねじりコイルバネ１４のねじり復元力（周方向の付勢力）により、アーム部材９およびテンションプーリ１２が、図1の左側に傾動してベルトＢの張力が一定になるよう調節される。
【００２５】
ベルトＢの張力が緩やかに増加した場合、ねじりコイルバネ１４のねじり復元力に抗してアーム部材９およびテンションプーリ１２が、図1の右側に傾動して、ベルトＢの張力が一定になるよう調節される。
【００２６】
さらに、オートテンショナ１に対してベルトＢから激しい振動や衝撃が加わった場合、テンションプーリ１２を支持しているアーム支持部６の基端ボス部７にその振動や衝撃が伝わることになるが、ねじりコイルバネ１４の伸張復元力により、基端ボス部７の端面を摩擦板２０に押付けて摩擦抵抗を発生させているので、ベルトＢからの振動や衝撃が吸収、減衰され、アーム部材９の不要な揺動を抑制することができる。これにより、テンションプーリ１２の変位が抑えられ、ベルトＢに対するテンションを一定に保つことができる。
【００２７】
ところで、本発明の実施の形態におけるオートテンショナ１では、上述したように、摩擦板２０は、ねじりコイルバネ１４の伸張復元力により基端ボス部７の端面と摩擦板押え部材２２とに対して所定圧力で押付けられて、基端ボス部７に対して回動抵抗を付与しているものであり、摩擦板押え部材２２の外周部に、ねじりコイルバネ１４の伸張復元力が、摩擦板２０を介して継続的に働いた状態にある。
【００２８】
しかし、本発明の実施の形態に係る摩擦板押え部材２２には、摩擦板押え部材２２の外周縁を折曲させて環状に形成した補強部２５を設けることで摩擦板押え部材２２の断面係数を増加させているので、摩擦板押え部材２２にねじりコイルバネ１４の伸張復元力が働いたとしても、この補強部２５によって、摩擦板押え部材２２の外周縁部が反り上がるといった変形を抑えることができる。
【００２９】
このように、摩擦板押え部材２２の変形を抑えることにより、摩擦板２０の偏摩耗を防止して摩擦板２０の面圧を継続的に均一に維持し、摩擦板押え部材２２に対する摩擦板２０の摺動動作を安定させてベルトＢに対して常に安定したテンションを付与することができる。
【００３０】
なお、上記実施の形態では、摩擦板押え部材２２の周方向に沿う補強部２５を、摩擦板押え部材２２の外周縁を折曲させて環状に形成したが、これに限定されるものではなく、例えば図４の断面図に示すように、平坦押え面２２ａに、軸心Ｃ方向に沿ってかつ摩擦板２０の反対側に向けて突出する環状の凸部を、プレス加工によって同心円上に複数列で形成して補強部２５としてもよい。
【００３１】
さらに、図５の斜視図に示すように、摩擦板押え部材２２の外周縁を折曲させて環状に形成するとともに、平坦押え面２２ａに、軸心Ｃ方向に沿ってかつ摩擦板２０の反対側に向けて突出する環状の凸部を、プレス加工によって同心円上に複数列で形成して補強部２５としてもよい。いずれの実施の形態の場合も凸部を形成することで、摩擦板押え部材２２の断面係数が増加して、確実に摩擦板押え部材２２の変形を抑えることができる。他の作用効果は上記実施の形態と同様である。
【００３２】
さらに、上記各実施の形態における摩擦板押え部材２２は、基端ボス部７に対して支軸部材５の軸心Ｃ方向に離間してオフセット配置（支軸部材５の先端よりも前方に突出した位置に配置）されるタイプのオートテンショナ１にも適用可能であり、この場合も、上記各実施の形態と同様の効果を奏し得る。
【００３３】
【発明の効果】
以上の説明から明らかな通り、本発明は、摩擦板をボス部の軸心方向端面に押圧して挟持する押え面を有した押え板に、軸心方向に沿ってかつ摩擦板の反対側に向けて突出するとともに、押え板の周方向に沿う補強部を形成して押え板の断面係数を増加させ、補強部は、押え板の外周縁を折曲させて環状に形成し、あるいは押え板の押え面を変形させて環状に形成しているので、押え板の外周部に、ばねの伸張復元力が、摩擦板を介して継続的に働いた状態にあっても、補強部によって押え板の外周縁部が反るような変形が抑えられ、したがって、摩擦板の偏摩耗を防止して摩擦板の面圧を継続的に均一に維持し、押え板に対する摩擦板の摺動動作を安定させて、ベルト駆動機構のベルトに対して常に安定したテンションを付与することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態を示すオートテンショナの正面図である。
【図２】同じく図1におけるＡ−Ａ線矢視断面図である。
【図３】同じく摩擦板押え部材の単体斜視図である。
【図４】同じく他の実施の形態を示す摩擦板押え部材の断面図である。
【図５】同じく他の実施の形態を示す摩擦板押え部材の単体斜視図である。
【符号の説明】
１オートテンショナ
５支軸部材
５Ａ環状空間
６アーム支持部
７基端ボス部
９アーム部材
１０プーリ支持部
１１転がり軸受
１２テンションプーリ
１３外筒部
１４ねじりコイルバネ
２０摩擦板
２２摩擦板押え部材
２５補強部
Ｃ軸心[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an auto tensioner for automatically and appropriately maintaining a belt tension of a belt driving mechanism.
[0002]
[Prior art]
In general, the auto tensioner allows the tension pulley to move in response to belt tension fluctuations caused by temperature changes in the environment or changes in expansion and contraction over time, and to reduce vibration and shock from the belt. It has a structure with a function to restrict movement.
[0003]
In order to realize such a function, an annular ring is formed in the gap between the front end surface of the boss portion of the tension pulley supporting arm and the presser plate (guide plate) integrally attached to the front end of the arm supporting shaft. The friction plate is sandwiched, and the friction plate is pressed against the boss portion and the presser plate by the extension restoring force of the torsion coil spring.
[0004]
[Problems to be solved by the invention]
By the way, in order to reduce the weight of the auto tensioner, a thin flat plate has been used as a presser plate. However, the tension restoring force of the torsion coil spring continuously acts on the presser plate via the friction plate.
[0005]
For this reason, the presser plate is deformed so that its outer peripheral portion is warped, and the surface pressure of the friction plate becomes non-uniform, and the friction plate is unevenly worn, or the friction plate is pressed against the presser plate. There was a problem that the sliding became unstable and the arm vibrated.
[0006]
In order to eliminate such inconvenience, it is conceivable to increase the rigidity of the presser plate to increase its rigidity. However, in this case, there arises a problem that it becomes impossible to reduce the weight of the auto tensioner.
[0007]
Accordingly, an object of the present invention is to provide an auto tensioner that can solve the above-described problems.
[0008]
[Means for Solving the Problems]
An auto tensioner according to a first aspect of the present invention is an auto tensioner for automatically and appropriately maintaining the belt tension of a belt drive mechanism, and has a fixed support shaft member and a boss portion with respect to the support shaft member. An arm that is rotatably fitted and supported; a spring that urges the arm to rotate in a fixed direction around the support shaft member; a tension pulley that is pivotally supported by the tip of the arm; A friction plate disposed in a concave portion formed on the end surface in the axial direction of the boss portion to provide rotation resistance to the arm, and attached to the end surface side in the axial direction of the support shaft member, and the friction plate is attached to the boss portion A presser plate having a flat presser surface that is pressed against and pinched in the axial direction end surface, and the outer peripheral edge of the presser plate is bent, and the bent part opens the opposite side of the friction plate. Extending in the axial direction toward the outside To form a reinforcement portion of the annular circumferentially continuous plate, characterized in that increased section modulus of the pressing plate.
An auto tensioner according to a second aspect of the present invention is an auto tensioner for automatically and appropriately maintaining the belt tension of the belt drive mechanism, and has a fixed support shaft member and a boss portion with respect to the support shaft member. An arm that is rotatably fitted and supported; a spring that urges the arm to rotate in a fixed direction around the support shaft member; a tension pulley that is pivotally supported by the tip of the arm; A friction plate disposed in a concave portion formed on the end surface in the axial direction of the boss portion to provide rotation resistance to the arm, and attached to the end surface side in the axial direction of the support shaft member, and the friction plate is attached to the boss portion A presser plate having a flat presser surface that is pressed against and clamped to the axial end surface of the presser plate, and the presser surface of the presser plate is bent, and the bent part is opened on the opposite side of the friction plate. Projected to extend in the axial direction toward the outside In addition, an annular reinforcing portion that is continuous in the circumferential direction of the presser plate is formed to increase the section modulus of the presser plate, and the bent portions protrude and bend so that the surfaces facing each other in the radial direction are in close contact with each other. It is characterized by that.
An auto tensioner according to a third aspect of the present invention is an auto tensioner for automatically and appropriately maintaining the belt tension of the belt driving mechanism, and a fixed support shaft member and a boss portion with respect to the support shaft member. An arm that is rotatably fitted and supported; a spring that urges the arm to rotate in a fixed direction around the support shaft member; a tension pulley that is pivotally supported by the tip of the arm; A friction plate disposed in a concave portion formed on the end surface in the axial direction of the boss portion to provide rotation resistance to the arm, and attached to the end surface side in the axial direction of the support shaft member, and the friction plate is attached to the boss portion A presser plate having a flat presser surface that is pressed against and pinched in the axial direction end surface, and the outer peripheral edge of the presser plate is bent, and the bent part opens the opposite side of the friction plate. Extending in the axial direction toward the outside An annular reinforcing portion that is continuous in the circumferential direction of the plate is formed, and the holding surface of the holding plate is bent, and this bent portion is axially directed toward the open outer side opposite to the friction plate. A bent portion formed on the pressing surface of the presser plate by forming an annular reinforcing portion that extends so as to extend in the circumferential direction and increasing the section modulus of the presser plate by the two reinforcing portions. Are characterized in that the surfaces facing each other in the radial direction are in close contact with each other by being projected and bent.
[0009]
In the above configuration, when the belt tension decreases, the restoring force of the spring adjusts the arm and the tension pulley so that the belt tension becomes constant, and when the belt tension increases, the restoring force of the spring increases. The arm and tension pulley are tilted in the opposite direction, and the belt tension is adjusted to be constant. In addition, when severe vibration or impact is applied from the belt, the boss part of the arm that supports the tension pulley The vibrations and shocks are transmitted. At this time, since the boss portion is pressed against the friction plate by the extension restoring force of the spring and frictional resistance is generated, vibration and impact are absorbed and attenuated, thereby suppressing unnecessary swinging of the arm member, The displacement of the tension pulley is suppressed, and the tension on the belt is kept constant.
[0011]
According to the above configuration, the outer peripheral edge portion of the presser plate is warped by the reinforcing portion even when the extension / restoring force of the spring continuously acts on the outer peripheral portion of the presser plate via the friction plate. Deformation is suppressed, therefore, the friction plate is prevented from uneven wear, the friction plate surface pressure is continuously maintained uniformly, the friction plate slides against the presser plate, and the belt is always stable against the belt. Apply tension.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a front view of an auto tensioner according to an embodiment of the present invention, FIG. 2 is a view taken along the line YY in FIG. 1, and FIG. 3 is a single perspective view of a friction plate pressing member.
[0013]
The auto tensioner 1 according to the embodiment of the present invention includes a spindle member 5 to which a mounting piece 18 is fixed by a bolt 2 at a predetermined location of a belt drive mechanism (not shown), and a truncated cone shape of the spindle member 5. Rolling bearings are provided on an arm member 9 in which an annular base end boss portion 7 is rotatably fitted and supported via a bush 8 with respect to the arm support portion 6, and a pulley support portion 10 at the distal end portion of the arm member 9. 11 and a tension pulley (manufactured by sheet metal pressing) 12 that is rotatably supported via a bolt 3 disposed along the axis C direction of the support shaft member 5.
[0014]
The support shaft member 5 is manufactured by die casting using an aluminum alloy or the like, and includes the arm support portion 6 and the outer cylinder portion 13, and the outer cylinder portion 13 has a diameter from the base end side of the arm support portion 6. It extends outward in the direction and extends to the free end side so as to surround the outer periphery of the arm support portion 6. The shape of the outer peripheral surface of the arm support portion 6 in this support shaft member 5 is the draft of the molding die. It corresponds.
[0015]
A torsion coil spring 14 is provided for rotating and biasing the arm member 9 around the support shaft member 5 in a fixed direction. The torsion coil spring 14 includes an outer peripheral surface of the arm support portion 6 and a proximal boss of the arm member 9. The annular space 5A formed between the outer peripheral surface of the portion 7 and the inner peripheral surface of the outer cylindrical portion 13 of the support shaft member 5 is arranged in a non-contact and torsionally compressed state with respect to each surface. ing.
[0016]
Bent portions 15 a and 15 b that are bent outward in the radial direction of the support shaft member 5 are integrally formed on both ends of the torsion coil spring 14, and these bent portions 15 a and 15 b are formed on the support member 5. The slit-shaped notch 16 formed on the bottom and the slit-shaped notch 17 formed on the proximal end boss 7 of the arm member 9 are respectively engaged.
[0017]
The torsion coil spring 14 urges the arm member 9 in the counterclockwise direction of FIG. 1 around the axis C by the torsional restoring force. The base end boss portion 7 has a function of pressing the base plate boss portion 7, which will be described later, to impart frictional resistance to the base end boss portion 7.
[0018]
The friction plate 20 is disposed in a recess 21 formed on the front end surface of the proximal boss 7 in the direction of the axis C, and is fixed to the distal end side of the arm support 6 in the support shaft member 5 by a bolt 19. The plate pressing member 22 is held in a state of being sandwiched between the flat pressing surface 22a.
[0019]
The friction plate 20 is pressed at a predetermined pressure against the end surface of the base boss portion 7 and the friction plate pressing member 22 by the extension restoring force of the torsion coil spring 14, and the resistance against rotation against the base end boss portion 7. Is granted.
[0020]
The friction plate 20 is made of, for example, a polyamide resin such as polyether ether ketone (PEEK), a clutch facing material, a brake lining material, or a brake pad material.
[0021]
Further, in order to prevent the friction plate 20 from rotating in the circumferential direction and deviating from an appropriate position, although not shown, a protrusion protruding radially outward is provided at one place on the end surface of the proximal boss portion 7. Thus, a concave portion that engages with the protrusion is formed at one place on the circumference of the center hole of the friction plate 20, and the friction plate 20 is immobilized by these engagements.
[0022]
The friction plate pressing member 22 has a fitting hole 30 formed at the center, and the fitting hole 30 is fitted and supported by a stepped convex portion 31 formed at the center of the front end surface of the base boss 7. A flange-shaped reinforcing portion 25 that protrudes toward the opposite side (outward) of the friction plate 20 along the axial center C direction and extends along the circumferential direction of the friction plate holding member 22 is formed on the friction plate holding member 22. The reinforcing portion 25 is integrally formed by pressing, and the outer peripheral edge of the friction plate pressing member 22 is bent to form an annular shape. By forming such a reinforcing portion 25, the section modulus (rigidity) of the friction plate pressing member 22 is increased.
[0023]
In the auto tensioner 1 according to the embodiment of the present invention, the movement of the tension pulley 12 is regulated so as to attenuate the vibration and impact from the belt B while allowing the movement of the tension pulley 12 according to the tension fluctuation of the belt B. .
[0024]
For example, when the tension of the belt B is gently reduced, the arm member 9 and the tension pulley 12 are tilted to the left in FIG. 1 by the torsional restoring force (circumferential biasing force) of the torsion coil spring 14, and the tension of the belt B is increased. Is adjusted to be constant.
[0025]
When the tension of the belt B increases moderately, the arm member 9 and the tension pulley 12 are tilted to the right in FIG. 1 against the torsional restoring force of the torsion coil spring 14 so that the tension of the belt B becomes constant. Is done.
[0026]
Furthermore, when intense vibration or impact is applied to the auto tensioner 1 from the belt B, the vibration or impact is transmitted to the base end boss portion 7 of the arm support portion 6 that supports the tension pulley 12. Since the end face of the base end boss 7 is pressed against the friction plate 20 by the extension restoring force of the torsion coil spring 14, the friction resistance is generated, so that the vibration and impact from the belt B are absorbed and attenuated, and the arm member 9 is unnecessary. Can be suppressed. Thereby, the displacement of the tension pulley 12 is suppressed, and the tension on the belt B can be kept constant.
[0027]
By the way, in the auto tensioner 1 according to the embodiment of the present invention, as described above, the friction plate 20 is predetermined with respect to the end surface of the base boss portion 7 and the friction plate pressing member 22 by the extension restoring force of the torsion coil spring 14. It is pressed by pressure and imparts rotational resistance to the proximal boss portion 7, and the extension restoring force of the torsion coil spring 14 is applied to the outer peripheral portion of the friction plate pressing member 22 via the friction plate 20. Is working continuously.
[0028]
However, the friction plate pressing member 22 according to the embodiment of the present invention is provided with a reinforcing portion 25 that is formed in an annular shape by bending the outer peripheral edge of the friction plate pressing member 22 so that the section coefficient of the friction plate pressing member 22 is increased. Therefore, even if the extension restoring force of the torsion coil spring 14 acts on the friction plate holding member 22, the reinforcing portion 25 can suppress deformation such as the outer peripheral edge of the friction plate holding member 22 warping up. it can.
[0029]
In this way, by suppressing the deformation of the friction plate pressing member 22, uneven wear of the friction plate 20 is prevented, the surface pressure of the friction plate 20 is continuously maintained uniformly, and the friction plate 20 against the friction plate pressing member 22 is maintained. Thus, it is possible to always apply a stable tension to the belt B.
[0030]
In the above-described embodiment, the reinforcing portion 25 along the circumferential direction of the friction plate pressing member 22 is formed in an annular shape by bending the outer peripheral edge of the friction plate pressing member 22. However, the present invention is not limited to this. For example, as shown in the cross-sectional view of FIG. 4, a plurality of annular convex portions that protrude along the axis C direction and toward the opposite side of the friction plate 20 are formed on the flat pressing surface 22a on a concentric circle by pressing. The reinforcing portion 25 may be formed in a row.
[0031]
Further, as shown in the perspective view of FIG. 5, the outer peripheral edge of the friction plate pressing member 22 is bent and formed into an annular shape, and the flat pressing surface 22 a is formed along the axis C direction and opposite to the friction plate 20. The annular convex portions projecting toward the side may be formed in a plurality of rows on concentric circles by press working to form the reinforcing portion 25. In any embodiment, by forming the convex portion, the section modulus of the friction plate pressing member 22 is increased, and the deformation of the friction plate pressing member 22 can be surely suppressed. Other functions and effects are the same as those of the above embodiment.
[0032]
Further, the friction plate pressing member 22 in each of the above embodiments is offset from the base boss portion 7 in the direction of the axis C of the support shaft member 5 (projects forward from the tip of the support shaft member 5). The present invention can also be applied to the type of auto tensioner 1 that is disposed at the position described above, and in this case as well, the same effects as those of the above embodiments can be obtained.
[0033]
【The invention's effect】
As is apparent from the above description, the present invention provides a pressing plate having a pressing surface that presses and holds the friction plate against the axial end surface of the boss portion, along the axial direction and on the opposite side of the friction plate. And the reinforcing part is formed along the circumferential direction of the presser plate to increase the section modulus of the presser plate, and the reinforcing part is formed in an annular shape by bending the outer peripheral edge of the presser plate, or the presser plate Since the presser face is deformed and formed into an annular shape, the presser plate is supported by the reinforcing part even if the spring's expansion and recovery force continues to act on the outer periphery of the presser plate via the friction plate. Therefore, deformation of the outer peripheral edge of the friction plate is suppressed, and therefore, the friction plate is prevented from uneven wear, and the surface pressure of the friction plate is continuously maintained to be uniform, and the sliding motion of the friction plate with respect to the presser plate is stabilized. To provide a stable tension to the belt of the belt drive mechanism. That.
[Brief description of the drawings]
FIG. 1 is a front view of an auto tensioner showing an embodiment of the present invention.
2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a single perspective view of the friction plate pressing member.
FIG. 4 is a cross-sectional view of a friction plate pressing member showing another embodiment.
FIG. 5 is a single perspective view of a friction plate pressing member according to another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Auto tensioner 5 Support shaft member 5A Annular space 6 Arm support part 7 Base end boss part 9 Arm member 10 Pulley support part 11 Rolling bearing 12 Tension pulley 13 Outer cylinder part 14 Torsion coil spring 20 Friction plate 22 Friction plate holding member 25 Reinforcement part C axis

Claims

An auto tensioner for automatically maintaining a belt tension of a belt driving mechanism appropriately,
A fixed support shaft member, an arm having a boss portion pivotably fitted to and supported by the support shaft member, a spring for biasing the arm in a fixed direction around the support shaft member, and an arm A tension pulley that is pivotally supported at the tip of the boss, a friction plate that is disposed in a recess formed in an end surface in the axial direction of the boss, and that provides rotational resistance to the arm, and the support member A pressing plate having a flat pressing surface that is attached to the axial end surface side and presses and holds the friction plate against the axial end surface of the boss portion,
By bending the outer peripheral edge of the presser plate, an annular reinforcing portion that extends in the axial direction toward the open outer side that is the opposite side of the friction plate and continues in the circumferential direction of the presser plate is formed by the bent portion. An auto tensioner that is formed to increase the section modulus of the presser plate.

An auto tensioner for automatically maintaining a belt tension of a belt driving mechanism appropriately,
A fixed support shaft member, an arm having a boss portion pivotably fitted to and supported by the support shaft member, a spring for biasing the arm in a fixed direction around the support shaft member, and an arm A tension pulley that is pivotally supported at the tip of the boss, a friction plate that is disposed in a recess formed in an end surface in the axial direction of the boss, and that provides rotational resistance to the arm, and the support member A pressing plate having a flat pressing surface that is attached to the axial end surface side and presses and holds the friction plate against the axial end surface of the boss portion,
The presser surface of the presser plate is bent, and the bent part projects in an axial direction toward the open outer side opposite to the friction plate, and continues in the circumferential direction of the presser plate. To increase the section modulus of the presser plate
The auto-tensioner according to claim 1, wherein the bent portions protrude and bend so that surfaces facing each other in the radial direction are in close contact with each other.

An auto tensioner for automatically maintaining a belt tension of a belt driving mechanism appropriately,
A fixed support shaft member, an arm having a boss portion pivotably fitted to and supported by the support shaft member, a spring for biasing the arm in a fixed direction around the support shaft member, and an arm A tension pulley that is pivotally supported at the tip of the boss, a friction plate that is disposed in a recess formed in an end surface in the axial direction of the boss, and that provides rotational resistance to the arm, and the support member A pressing plate having a flat pressing surface that is attached to the axial end surface side and presses and holds the friction plate against the axial end surface of the boss portion,
By bending the outer peripheral edge of the presser plate, an annular reinforcing portion that extends in the axial direction toward the open outer side that is the opposite side of the friction plate and continues in the circumferential direction of the presser plate is formed by the bent portion. With forming
The holding surface of the press plate is bent, and the bent portion projects to extend outward in the axial direction toward the open outer side opposite to the friction plate, and continues in the circumferential direction of the press plate. Forming a reinforcing part of the above, increasing the section modulus of the presser plate by the two reinforcing parts,
The auto tensioner, wherein the bent portion formed on the pressing surface of the pressing plate protrudes and is bent so that the radially opposing surfaces are in close contact with each other.