JP4081348B2

JP4081348B2 - Method for manufacturing element of transmission belt for continuously variable transmission

Info

Publication number: JP4081348B2
Application number: JP2002312624A
Authority: JP
Inventors: 康誠三井; 剛克藤田; 尚松永
Original assignee: Mitsui High Tech Inc
Current assignee: Mitsui High Tech Inc
Priority date: 2002-10-28
Filing date: 2002-10-28
Publication date: 2008-04-23
Anticipated expiration: 2022-10-28
Also published as: JP2004141958A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車やその他の産業機械で使用されている無段変速機用伝動ベルトのエレメントの製造方法に関する。
【０００２】
【従来の技術】
従来、図６（Ａ）に示すように、自動車等の無段変速機８０においては、溝幅可変のＶ形の駆動側プーリ８１と被駆動側プーリ８２間の動力伝達に伝動ベルト８３が採用されている。この伝動ベルト８３は、図６（Ｂ）に示すように、金属製の無端バンド８４、８５と、この無端バンド８４、８５が両側からそれぞれ挟み込まれる多数のエレメント８６から構成されており、使用にあっては、伝動ベルト８３を駆動側プーリ８１及び被駆動側プーリ８２に掛け渡すことにより、駆動側プーリ８１の回転力が伝動ベルト８３を介して被駆動側プーリ８２に伝達される。
このとき、伝動ベルト８３は、駆動側プーリ８１を通って被駆動側プーリ８２側に、或いは、被駆動側プーリ８２を通って駆動側プーリ８１側に走行方向を変えるため、各エレメント８６が円滑に各プーリ８１、８２の周りを回れるように、図７に示すように、各プーリ８１、８２に接するエレメント８６のサドル部８７の下側部分の板厚を薄くする必要があった。一方、エレメント８６の上板部８８、サドル部８７の上側部分８９、及び上板部８８とサドル部８７との連結部９０は、強度確保の点から厚くする必要があった。このように、エレメント８６は、単一品内で板厚が変わっている（例えば、特許文献１参照。）。
なお、このような形状のエレメント８６は、板材から複数回の打抜き成形加工を行うことで製造されていた。
【０００３】
【特許文献１】
特開平１１−１１７９９９号公報（第２頁右欄９〜２７行目、図８、図９）
【０００４】
【発明が解決しようとする課題】
しかしながら、上記したエレメントの打抜きに使用する板材は、圧延技術等が進歩しているものの、板厚偏差が板幅方向で例えば１０μｍ程度存在するので、隣合うエレメント８６が当接する上板部８８、サドル部８７の上側部分８９、及び連結部９０の板厚を調整することなく打抜き形成されたエレメント８６には、その影響が残っている。このエレメント８６は、図７に示したように、多数個、例えば１００〜４００個連続して接続した形態で使用されるので、伝動ベルト８３が駆動側プーリ８１から被駆動側プーリ８２へ走行している場合、及び被駆動側プーリ８２から駆動側プーリ８１へ走行している場合、エレメント８６のサドル部８７の上側部分８９の板厚が均一であれば、図８の二点鎖線で示すように、伝動ベルト８３は平面視して真っ直ぐになるが、例えば板幅方向に僅かな偏差（例えば１０μｍ）が生じれば、図８の実線で示すように、板厚偏差が累積して伝動ベルト８３が曲がったり、この曲がりにより応力が発生して伝動ベルト８３の耐久性が著しく損なわれる恐れがある。また、これにより騒音を生じる問題がある。
本発明はかかる事情に鑑みてなされたもので、伝動ベルトに曲がりが生じることなく動力の伝達が円滑に行われ、伝動ベルトの耐久性を高めることが可能で、かつ騒音を生じない無段変速機用伝動ベルトのエレメントの製造方法を提供することを目的とする。
【０００５】
【課題を解決するための手段】
前記目的に沿う本発明に係る無段変速機用伝動ベルトのエレメントの製造方法は、使用にあってはＶ溝プーリの内側壁に接する傾斜部が両側に設けられ、かつ下側部分に板厚を薄くした板厚減少部が形成されたサドル部と、該サドル部の上側位置に設けられた上板部と、該上板部と前記サドル部を連結する連結部を有し、該連結部の左右にあって、前記サドル部と前記上板部の間には、使用にあっては金属製の無端バンドを装着するバンド保持部を備えた無段変速機用伝動ベルトのエレメントを、板材から打抜き形成する方法において、
前記板材の少なくとも前記板厚減少部以外の前記エレメント打抜き予定位置の板厚を実質的に均一にする板厚調整加工を行う水平部、及び前記板厚減少部に対応する部分の板厚を薄くする減肉加工を行う傾斜部を備えたパンチと水平のダイによって、板幅方向全体にプレス加工を行うプレス加工工程と、
板幅方向全体にプレス加工された前記板材から、前記サドル部の中央下端部及び前記上板部の上端部にそれぞれ設けられて該エレメントを該板材の枠部に繋ぐ連結片を除く前記エレメントの外形抜きを行う打抜き加工工程と、
外形抜きされた前記エレメントの周辺部を仕上げ金型装置によって成形を行う押圧成形加工工程と、
前記押圧成形加工工程によって処理された前記エレメントを前記連結片で前記枠部に繋がった状態で、熱処理する工程と、
前記連結片で前記枠部に繋がった前記エレメントを前記枠部から分離する工程とを有する。
このように、プレス加工工程で、エレメント打抜き予定位置の板厚を実質的に均一にする板厚調整加工を行うので、打抜き加工工程及び押圧成形加工工程を経て製造されたエレメントの板幅方向の板厚偏差を無くすことができる。
ここで、本発明に係る無段変速機用伝動ベルトのエレメントの製造方法において、プレス加工工程の板厚調整加工及び減肉加工は、板材の板幅方向全体にわたって行われる。これにより、形状精度の優れたエレメントが製造される。
【０００６】
【発明の実施の形態】
続いて、添付した図面を参照しつつ、本発明を具体化した実施の形態につき説明し、本発明の理解に供する。
ここに、図１は本発明の一実施の形態に係る無段変速機用伝動ベルトのエレメントの製造方法のプレス加工工程の説明図、図２（Ａ）、（Ｂ）はそれぞれ同方法で製造するエレメントの正面図、平面図、図３は同方法のプレス加工工程前後の条材の説明図、図４は同方法の打抜き加工工程の説明図、図５は同方法の押圧成形加工工程の説明図である。
【０００７】
まず、図２（Ａ）、（Ｂ）を参照しながら、本発明の一実施の形態に係る無段変速機用伝動ベルトのエレメントの製造方法を適用して製造したエレメント１０について説明する。エレメント１０は、材質が例えば、炭素工具鋼（ＳＫ）、合金工具鋼（ＳＫＳ）、その他の焼入れ焼戻し可能な合金鋼等からなって、板厚が例えば１．８〜２．５ｍｍの板材の一例である条材Ａ（図１参照）から金型によって形状加工される製品である。このエレメント１０は、サドル部１１と、このサドル部１１の上側位置に一体的に連結され、使用にあっては金属製の無端バンドを装着するバンド保持部の一例である平行溝部１２、１３とを備えている。
【０００８】
サドル部１１は、使用にあってはＶ溝プーリの内側壁に接する直線状の傾斜部１４、１５が両側に設けられ、かつ下側部分に板厚が薄くなった板厚減少部１６が形成されている。この傾斜部１４、１５の傾斜角度は、組立てられた状態の無段変速機用伝動ベルトを使用するＶ溝プーリの内側壁の傾斜角度に一致している。このように、サドル部１１は、板厚減少部１６の上端である途中位置１７から上方への厚みが一定であるが、途中位置１７から下方へかけては徐々にその厚みが薄くなって片面が傾斜している。この板厚減少部１６の下端、即ち最も厚みが薄い部分の板厚は、元の板厚の例えば１／３〜２／３となっている。
なお、サドル部１１の下端部には、全体の重量を軽減するために左右対となる切り込み１８、１９が設けられている。
また、サドル部１１の上側位置には、角部が丸くなった２等辺三角形の上板部２０と、この上板部２０とサドル部１１とを連結する連結部２１とを有している。そして、連結部２１の左右であって、サドル部１１と上板部２０との間には、前記したバンド保持部の一例である平行溝部１２、１３がそれぞれ形成されている。
【０００９】
上板部２０の各斜辺２２、２３は、内側に緩やかに湾曲し、上板部２０の中央部分の一方（背側）には凹部２４を、他方（前側）には凸部２５を備えている。凹部２４は断面円形の丸孔からなり、凸部２５は隣合うエレメント１０の凹部２４に僅少の隙間を有して入り込む断面円形の円柱状突起からなっている。また、凸部２５の高さは、凹部２４の深さよりも小さくなって、積層状態にある各エレメント１０の傾斜角度が多少変わっても、凸部２５が凹部２４に常時嵌入するようになって、複数の積重ねられたエレメント１０の姿勢を常時一定に保つ機能を有している。
また、連結部２１とサドル部１１との接続部分には、サドル部１１側に入り込んだ部分円形の逃げ溝２６、２７がそれぞれ設けられ、また連結部２１と上板部２０との接続部分には、上板部２０側に入り込んだ部分円形の逃げ溝２８、２９がそれぞれ設けられている。
【００１０】
サドル部１１、上板部２０、及び連結部２１によって形成される左右の平行溝部１２、１３は、この部分に十分な強度を有し繰返し曲げに強い材質からなる断面長方形の無端バンド（一般に、スチール、無端リングとも言われる）がそれぞれ嵌入している（図６（Ｂ）参照）。従って、このエレメント１０において、Ｖ溝プーリの接する傾斜部１４、１５と無端バンドに接する平行溝部１２、１３の形状が、一定の品質を保持する必要がある。
このように構成することで、無段変速機用伝動ベルトがＶ溝プーリに沿って湾曲する場合、各エレメント１０の凹部２４に凸部２５を係合させた状態で、板厚減少部１６により各エレメント１０を円滑に接触させることが可能になる（図７参照）。
【００１１】
続いて、本発明の一実施の形態に係る無段変速機用伝動ベルトのエレメントの製造方法について説明する。
本発明の一実施の形態に係る無段変速機用伝動ベルトのエレメントの製造方法は、プレス加工工程、打抜き加工工程、押圧成形加工工程、及び熱処理工程を有している。
まず、図１、図３に示すように、プレス加工工程では、押圧加工（コイニング、つぶし加工とも言う）を行う押圧金型装置３０を用いて、リールから巻戻され板幅方向の両側部に所定ピッチで仮ガイド孔３１が形成された条材Ａに、板厚調整加工及び減肉加工を施した後、リールに巻いてコイル状にする。
【００１２】
押圧金型装置３０は、板厚減少部１６以外のエレメント打抜き予定位置３２の板厚を実質的に均一にする板厚調整加工を行う水平部３３、及び板厚減少部１６に対応する部分の板厚を薄くする減肉加工を行う傾斜部３４を備えたパンチ３５と、水平のダイ３６とを備えている。この押圧金型装置３０のパンチ３５とダイ３６により、材料メーカーで製造され、所望サイズにスリット（切断）された条材Ａを、板幅方向全体にわたって押圧加工し、条材Ａに板厚均一部３７と傾斜加工部３８とからなる段差加工部３９を形成することができる。なお、押圧金型装置３０には、パンチ３５に対して上下動するストリッパ４０が設けられており、パンチ３５及びダイ３６によって条材Ａに板厚調整加工及び減肉加工を施し、段差加工部３９を形成した後は、条材Ａに当接したストリッパ４０に対してパンチ３５を上昇させることで、条材Ａからパンチ３５を容易に抜取ることができる。
【００１３】
板厚均一部３７（図３の右上がり斜線）は、パンチ３５の水平部３３によって押圧され、条材Ａの板厚減少部１６以外のエレメント打抜き予定位置３２を含む板幅方向全体にわたって形成されたもので、板厚偏差がなくなり、実質的に均一な板厚を有している。また、傾斜加工部３８（図３の左上がり斜線）は、パンチ３５の傾斜部３４によって押圧され、条材Ａの板厚減少部１６に対応する部分を含む板幅方向全体にわたって形成されたもので、板厚均一部３７の反対側に向かって徐々に傾斜して板厚が薄くなっている。
このとき、板厚均一部３７及び傾斜加工部３８が形成された段差加工部３９は、幾分加工硬化し、内部応力が発生する。
【００１４】
ここで、プレス加工工程で板厚調整加工及び減肉加工が施された条材Ａに対して、必要に応じて焼鈍を行って内部応力を除去してもよい。
この焼鈍は、例えば７００〜８５０℃の温度範囲で行うことが好ましく、バッチ処理で行う場合は、条材Ａを例えば７００〜７６０℃で１〜５時間加熱処理し、連続処理（リール・ツー・リールとも言う）で行う場合は、条材Ａを例えば７６０〜８５０℃で１〜３０分間加熱処理する。
【００１５】
続いて、条材Ａを、打抜き加工工程で加工処理する。図４に示すように、打抜き加工工程では、条材Ａの板幅方向の両側部に所定ピッチで新たなガイド孔４１が形成され、リールから巻戻された条材Ａから、打抜き金型装置（図示しない）を用いて、エレメント１０の外形抜きを行う。
この工程では、金型装置によってエレメント１０の上板部２０に凹部２４及び凸部２５が形成された条材Ａに対して、エレメント１０のサドル部１１、連結部２１、及び上板部２０の外形抜きを行う。この金型装置は、実質的にエレメント１０のサドル部１１、連結部２１、及び上板部２０の輪郭に対応した形状を備えるパンチ、及びこれと対となるダイを備えている。そして、外形がパンチによって抜き落とされた打抜き部４２によって形成されるエレメント１０のサドル部１１の中央下端部、及び上板部２０の上端部がそれぞれ、条材Ａの枠部４３と連結片４４、４５を介して繋がっている。
なお、サドル部１１、連結部２１、及び上板部２０の外形打抜きを一度に行うことなく、まずサドル部１１及び連結部２１の外形打抜きを行った後、上板部２０の外形打抜きを行うことも可能である。
【００１６】
次に、外形抜きされたエレメント１０を押圧成形加工工程で加工処理し、エレメント１０の周辺部の成形を行う。サドル部１１、連結部２１、及び上板部２０の外形抜きが終了した時点では、図５に示すように、サドル部１１、連結部２１、及び上板部２０の周辺部にバリ４６が生じる。しかし、サドル部１１の各傾斜部１４、１５はＶ溝プーリに接する部分であり、またサドル部１１、連結部２１、及び上板部２０の平行溝部１２、１３を形成する部分は無端バンドが装着される部分であるため、バリ４６の発生や寸法精度の悪さがエレメント１０の製品品質を悪くする。このため、エレメント１０の最終形状に対応した形状（角に丸みを備えた形状）のパンチ４７及びダイ４８を備えた仕上げ金型装置４９により、サドル部１１、連結部２１、及び上板部２０の周囲の仕上げ加工を行う。なお、この仕上げ加工は、条材Ａの硬さやエレメント１０の形状精度を考慮して、１つの工程で行うことも、また２つ以上の工程で行うことも可能である。
また、サドル部１１及び連結部２１の外形打抜きを行う打抜き加工工程を行い、サドル部１１及び連結部２１の仕上げ加工を行う押圧成形加工工程を行った後、上板部２０の外形打抜きを行う打抜き加工工程を行い、上板部２０の仕上げ加工を行う押圧成形加工工程を行うことも可能である。
【００１７】
押圧成形加工工程が終了した後、エレメント１０が条材Ａに連結片４４、４５を介して一部固定された状態で、熱処理工程を行う。この熱処理工程は、エレメント１０が例えば、耐衝撃性、耐摩耗性、靱性等を有するように、焼入れ、又は焼入れ焼戻し等を行う工程である。
焼入れは、一部がオーステナイト化する温度、例えば条材Ａの成分組成にもよるが、条材Ａを例えば７５０℃以上に加熱し、強制冷却して行う。また、焼入れ後の焼戻しは、焼入れ歪みを除去し、しかも打抜き品の固溶炭素を減らさない温度範囲で行うことが好ましく、例えば２５０℃以下で行う。
なお、それぞれの加熱温度、加熱時間、冷却時間等は、材料が決まれば周知の技術であるので、詳しい説明を省略する。この熱処理は、全部のエレメント１０が条材Ａに一部連結された状態で行うと、均一な熱処理を行うことができ、更には、作業を連続的に行うこともできる。
【００１８】
以上の処理によって、上記特性を有するエレメント１０が製造できるので、切り離し装置（例えば、トリム装置）を用いて、パンチによって条材Ａの枠部４３からエレメント１０を分離する。この分離は、前記パンチにより容易に行うことができる。
なお、押圧成形加工工程が終了した後、条材Ａの枠部４３からエレメント１０を切り離し、バッチ処理で熱処理を行うことも可能である。
【００１９】
以上、本発明を、一実施の形態を参照して説明してきたが、本発明は何ら上記した実施の形態に記載の構成に限定されるものではなく、特許請求の範囲に記載されている事項の範囲内で考えられるその他の実施の形態や変形例も含むものである。例えば、前記したそれぞれの実施の形態や変形例の一部又は全部を組合せて本発明の無段変速機用伝動ベルトのエレメントの製造方法を構成する場合も本発明の権利範囲に含まれる。
また、前記実施の形態においては、エレメントの板厚減少部の形状を、片側面のみに傾斜面が設けられ、他方が連結部に連続する平面とした場合について説明した。しかし、エレメントの板厚減少部の形状を他の形状、例えば、表面側と裏面側の両面を傾斜面にしたり、また片側面をアール面取りし、側面視して部分円形、部分楕円形とすることも、更に板厚減少部の板厚を連結部の板厚より薄くし、片側面のみを連結部に連続する平面とした段差形状とすること等にできる。
【００２０】
そして、前記実施の形態においては、条材に対して、板厚減少部以外のエレメント打抜き予定位置の板厚を実質的に均一にする板厚調整加工、及び板厚減少部に対応する部分の板厚を薄くする減肉加工を同時に行った場合について説明した。しかし、板厚調整加工と減肉加工を行う金型をそれぞれ個別に用意し、板厚減少部以外のエレメント打抜き予定位置に板厚調整加工を行った後、板厚減少部に対応する部分に減肉加工を行うことも可能である。
【００２１】
【発明の効果】
請求項１及び２記載の無段変速機用伝動ベルトのエレメントの製造方法においては、プレス加工工程で、エレメント打抜き予定位置の板厚を実質的に均一にする板厚調整加工を行うので、打抜き加工工程及び押圧成形加工工程を経て製造されたエレメントの板幅方向の板厚偏差を無くすことができる。これにより、エレメントを多数個連続して構成した伝動ベルトは、平面視して真っ直で曲がりがなく、動力の伝動機能を高めることができ、かつ騒音を生じない。また、伝動ベルトの曲がりによる応力の発生を防止できるので、伝動ベルトの寿命を高めることができ、併せて信頼性も優れる。
また、板幅方向全体にわたって板厚調整加工及び減肉加工を行うので、形状精度の優れたエレメントが安定して製造される。
【図面の簡単な説明】
【図１】本発明の一実施の形態に係る無段変速機用伝動ベルトのエレメントの製造方法のプレス加工工程の説明図である。
【図２】（Ａ）、（Ｂ）はそれぞれ同方法で製造するエレメントの正面図、平面図である。
【図３】同方法のプレス加工工程前後の条材の説明図である。
【図４】同方法の打抜き加工工程の説明図である。
【図５】同方法の押圧成形加工工程の説明図である。
【図６】（Ａ）、（Ｂ）はそれぞれ従来例に係る無段変速機の説明図、無段変速機用伝動ベルトの部分拡大図である。
【図７】同無段変速機用伝動ベルトの進行方向が変わる場合の説明図である。
【図８】同無段変速機用伝動ベルトを構成する多数のエレメントを並べた状態の説明図である。
【符号の説明】
１０：エレメント、１１：サドル部、１２、１３：平行溝部（バンド保持部）、１４、１５：傾斜部、１６：板厚減少部、１７：途中位置、１８、１９：切り込み、２０：上板部、２１：連結部、２２、２３：斜辺、２４：凹部、２５：凸部、２６〜２９：逃げ溝、３０：押圧金型装置、３１：仮ガイド孔、３２：エレメント打抜き予定位置、３３：水平部、３４：傾斜部、３５：パンチ、３６：ダイ、３７：板厚均一部、３８：傾斜加工部、３９：段差加工部、４０：ストリッパ、４１：ガイド孔、４２：打抜き部、４３：枠部、４４、４５：連結片、４６：バリ、４７：パンチ、４８：ダイ、４９：仕上げ金型装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing an element of a transmission belt for a continuously variable transmission used in automobiles and other industrial machines.
[0002]
[Prior art]
Conventionally, as shown in FIG. 6A, in a continuously variable transmission 80 such as an automobile, a transmission belt 83 is used for power transmission between a V-shaped driving pulley 81 and a driven pulley 82 having a variable groove width. Has been. As shown in FIG. 6 (B), the transmission belt 83 is composed of metal endless bands 84 and 85 and a large number of elements 86 in which the endless bands 84 and 85 are sandwiched from both sides. Then, the rotational force of the driving pulley 81 is transmitted to the driven pulley 82 via the transmission belt 83 by passing the transmission belt 83 over the driving pulley 81 and the driven pulley 82.
At this time, since the transmission belt 83 changes the traveling direction to the driven pulley 82 side through the driving pulley 81 or to the driving pulley 81 side through the driven pulley 82, each element 86 is smooth. As shown in FIG. 7, it is necessary to reduce the plate thickness of the lower portion of the saddle portion 87 of the element 86 in contact with the pulleys 81 and 82 so that the pulleys 81 and 82 can be turned around. On the other hand, the upper plate portion 88 of the element 86, the upper portion 89 of the saddle portion 87, and the connecting portion 90 between the upper plate portion 88 and the saddle portion 87 need to be thick from the viewpoint of ensuring strength. In this way, the element 86 has a different thickness within a single product (see, for example, Patent Document 1).
In addition, the element 86 having such a shape has been manufactured by performing punching and forming a plurality of times from a plate material.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-117999 (page 2, right column, lines 9 to 27, FIGS. 8 and 9)
[0004]
[Problems to be solved by the invention]
However, although the plate material used for punching the element described above has progressed in rolling technology and the like, the plate thickness deviation exists, for example, about 10 μm in the plate width direction, so the upper plate portion 88 with which the adjacent element 86 abuts, The effect remains in the upper portion 89 of the saddle portion 87 and the element 86 formed by punching without adjusting the plate thickness of the connecting portion 90. As shown in FIG. 7, the element 86 is used in a form in which a large number, for example, 100 to 400, are continuously connected, so that the transmission belt 83 travels from the driving pulley 81 to the driven pulley 82. If the plate thickness of the upper portion 89 of the saddle portion 87 of the element 86 is uniform when traveling from the driven pulley 82 to the driving pulley 81, as indicated by a two-dot chain line in FIG. In addition, the transmission belt 83 is straight in a plan view. For example, if a slight deviation (for example, 10 μm) occurs in the plate width direction, the plate thickness deviation is accumulated as shown by the solid line in FIG. 83 may be bent, or stress may be generated by the bending, and the durability of the transmission belt 83 may be significantly impaired. In addition, this causes a problem of generating noise.
The present invention has been made in view of such circumstances, and the transmission of power is smoothly performed without bending of the transmission belt, the durability of the transmission belt can be enhanced, and the continuously variable transmission does not generate noise. An object of the present invention is to provide a method for manufacturing an element of a mechanical transmission belt.
[0005]
[Means for Solving the Problems]
In the use of the element manufacturing method of the transmission belt for continuously variable transmission according to the present invention in accordance with the above-mentioned object, in use, inclined portions contacting the inner wall of the V-groove pulley are provided on both sides, and the plate thickness is formed on the lower portion. the has thinned and the saddle portion thickness reduction portion is formed with a top plate provided on the upper position of the saddle portion, a connecting portion for connecting the saddle portion and the upper plate portion, the connecting portion The element of the transmission belt for continuously variable transmission provided with a band holding part for mounting a metal endless band in use between the saddle part and the upper plate part In the method of punching forming from
Horizontal portion for performing thickness adjustment process be substantially uniform at least the thickness of the element punching scheduled position other than the plate thickness reduction of the plate, and thin the thickness of the portion corresponding to the plate thickness reduction portion A pressing process for pressing the entire plate width direction by means of a punch and a horizontal die having an inclined portion for performing the thinning process;
From the plate material pressed in the entire plate width direction, the element of the element except for the connecting piece that is provided at the center lower end portion of the saddle portion and the upper end portion of the upper plate portion and connects the element to the frame portion of the plate material . A punching process for punching the outer shape;
And pressing molding step for molding by the finishing mold apparatus periphery of outer vent has been the element,
A process of heat-treating the element processed by the press molding process in a state of being connected to the frame portion by the connecting piece;
Separating the element connected to the frame portion by the connecting piece from the frame portion .
In this way, in the press working process, the plate thickness adjustment process is performed to make the plate thickness at the element punching planned position substantially uniform. Therefore, in the plate width direction of the element manufactured through the punching process and the press molding process. Thickness deviation can be eliminated.
Here, in the manufacturing method of the element of the transmission belt for continuously variable transmission according to the present invention, the plate thickness adjustment processing and the thickness reduction processing in the press working step are performed over the entire plate width direction of the plate material. Thereby, an element with excellent shape accuracy is manufactured.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is an explanatory view of a pressing process of a method of manufacturing an element of a transmission belt for continuously variable transmission according to an embodiment of the present invention, and FIGS. 2 (A) and 2 (B) are manufactured by the same method. FIG. 3 is an explanatory view of the strip material before and after the pressing process of the method, FIG. 4 is an explanatory view of the punching process of the method, and FIG. 5 is a press forming process of the method. It is explanatory drawing.
[0007]
First, an element 10 manufactured by applying a method for manufacturing an element of a transmission belt for continuously variable transmission according to an embodiment of the present invention will be described with reference to FIGS. 2 (A) and 2 (B). The element 10 is made of, for example, carbon tool steel (SK), alloy tool steel (SKS), other quenchable and temperable alloy steel, and the like, and the plate thickness is, for example, 1.8 to 2.5 mm. It is the product shape-processed with a metal mold | die from the strip material A (refer FIG. 1) which is. The element 10 is integrally connected to a saddle portion 11 and an upper position of the saddle portion 11, and in use, parallel groove portions 12 and 13, which are examples of band holding portions to which metal endless bands are attached, It has.
[0008]
In use, the saddle portion 11 is formed with a plate thickness reducing portion 16 in which linear inclined portions 14 and 15 in contact with the inner wall of the V-groove pulley are provided on both sides and the plate thickness is reduced in the lower portion. Has been. The inclination angles of the inclined portions 14 and 15 coincide with the inclination angle of the inner wall of the V-groove pulley that uses the assembled transmission belt for continuously variable transmission. As described above, the saddle portion 11 has a constant thickness upward from the midway position 17 that is the upper end of the plate thickness reducing portion 16, but the thickness gradually decreases from the midway position 17 downward. Is inclined. The thickness of the lower end of the thickness reducing portion 16, that is, the thickness of the thinnest portion is, for example, 1/3 to 2/3 of the original thickness.
In addition, the lower end of the saddle portion 11 is provided with notches 18 and 19 that are paired left and right to reduce the overall weight.
In addition, the upper side portion of the saddle portion 11 includes an upper plate portion 20 of an isosceles triangle having a rounded corner portion, and a connecting portion 21 that connects the upper plate portion 20 and the saddle portion 11. Parallel groove portions 12 and 13, which are examples of the band holding portion, are formed on the left and right sides of the connecting portion 21 and between the saddle portion 11 and the upper plate portion 20.
[0009]
Each of the oblique sides 22 and 23 of the upper plate portion 20 is gently curved inward, and has a concave portion 24 on one (back side) of the central portion of the upper plate portion 20 and a convex portion 25 on the other (front side). Yes. The concave portion 24 is formed of a round hole having a circular cross section, and the convex portion 25 is formed of a cylindrical protrusion having a circular cross section that enters the concave portion 24 of the adjacent element 10 with a slight gap. Further, the height of the convex portion 25 is smaller than the depth of the concave portion 24, so that the convex portion 25 always fits into the concave portion 24 even if the inclination angle of each element 10 in the laminated state is slightly changed. In addition, the plurality of stacked elements 10 have a function of constantly maintaining the posture of the element 10.
The connecting portion between the connecting portion 21 and the saddle portion 11 is provided with partial circular relief grooves 26 and 27 that enter the saddle portion 11 side, and the connecting portion between the connecting portion 21 and the upper plate portion 20 is provided at the connecting portion. Are provided with partially circular relief grooves 28 and 29 that enter the upper plate 20 side.
[0010]
The left and right parallel groove portions 12 and 13 formed by the saddle portion 11, the upper plate portion 20, and the connecting portion 21 are endless bands having a rectangular cross section (generally, made of a material that has sufficient strength and resistance to repeated bending in this portion. Steel (also referred to as endless ring) is inserted (see FIG. 6B). Therefore, in this element 10, it is necessary to maintain a certain quality in the shapes of the inclined portions 14 and 15 in contact with the V-groove pulley and the parallel groove portions 12 and 13 in contact with the endless band.
With such a configuration, when the transmission belt for continuously variable transmission is curved along the V-groove pulley, the plate thickness reducing portion 16 causes the convex portion 25 to engage with the concave portion 24 of each element 10. Each element 10 can be brought into smooth contact (see FIG. 7).
[0011]
Then, the manufacturing method of the element of the transmission belt for continuously variable transmission which concerns on one embodiment of this invention is demonstrated.
A method for manufacturing an element of a transmission belt for continuously variable transmission according to an embodiment of the present invention includes a pressing process, a punching process, a press forming process, and a heat treatment process.
First, as shown in FIGS. 1 and 3, in the pressing process, a pressing die device 30 that performs pressing (also referred to as coining or crushing) is used to unwind the reel from both sides in the plate width direction. The strip material A in which the temporary guide holes 31 are formed at a predetermined pitch is subjected to plate thickness adjustment processing and thinning processing, and then wound around a reel to form a coil.
[0012]
The pressing die device 30 includes a horizontal portion 33 that performs plate thickness adjustment processing for making the plate thickness at the element punching scheduled positions 32 other than the plate thickness reducing portion 16 substantially uniform, and portions corresponding to the plate thickness reducing portion 16. The punch 35 provided with the inclination part 34 which performs the thinning process which makes plate | board thickness thin is provided, and the horizontal die | dye 36 is provided. The strip A manufactured by a material manufacturer and slitted (cut) to a desired size is pressed over the entire plate width direction by the punch 35 and the die 36 of the pressing mold apparatus 30, and the strip A has a uniform thickness. A step processed portion 39 composed of the portion 37 and the inclined processing portion 38 can be formed. The pressing die device 30 is provided with a stripper 40 that moves up and down with respect to the punch 35. The strip 35 is subjected to plate thickness adjustment processing and thickness reduction processing by the punch 35 and the die 36, and a step processing portion. After forming 39, the punch 35 can be easily extracted from the strip A by raising the punch 35 with respect to the stripper 40 in contact with the strip A.
[0013]
The plate thickness uniform portion 37 (inclined to the right in FIG. 3) is pressed by the horizontal portion 33 of the punch 35 and is formed over the entire plate width direction including the element punching planned position 32 other than the plate thickness reducing portion 16 of the strip A. Therefore, the thickness deviation is eliminated and the thickness is substantially uniform. Further, the inclined processing portion 38 (upward left slanting line in FIG. 3) is pressed by the inclined portion 34 of the punch 35 and formed over the entire plate width direction including the portion corresponding to the plate thickness reducing portion 16 of the strip A. Thus, the plate thickness is gradually inclined toward the opposite side of the plate thickness uniform portion 37 to reduce the plate thickness.
At this time, the step processed portion 39 in which the plate thickness uniform portion 37 and the inclined processed portion 38 are formed is somewhat work-hardened and internal stress is generated.
[0014]
Here, the strip A that has been subjected to plate thickness adjustment processing and thickness reduction processing in the press processing step may be annealed as necessary to remove internal stress.
This annealing is preferably performed in a temperature range of, for example, 700 to 850 ° C. When batch processing is performed, the strip A is subjected to heat treatment at, for example, 700 to 760 ° C. for 1 to 5 hours to perform continuous processing (reel-to-reel). In the case of carrying out by reel), the strip A is heat-treated at, for example, 760 to 850 ° C. for 1 to 30 minutes.
[0015]
Subsequently, the strip material A is processed in a punching process. As shown in FIG. 4, in the punching process, new guide holes 41 are formed at predetermined pitches on both sides in the plate width direction of the strip material A, and the punching die device is formed from the strip material A unwound from the reel. The outer shape of the element 10 is removed using (not shown).
In this step, the saddle portion 11, the connecting portion 21, and the upper plate portion 20 of the element 10 are formed on the strip A in which the concave portion 24 and the convex portion 25 are formed on the upper plate portion 20 of the element 10 by the mold device. Remove the outline. This mold apparatus includes a punch having a shape substantially corresponding to the contours of the saddle portion 11, the connecting portion 21, and the upper plate portion 20 of the element 10, and a die that is paired therewith. And the center lower end part of the saddle part 11 of the element 10 and the upper end part of the upper plate part 20 which are formed by the punching part 42 whose outer shape has been removed by punching are the frame part 43 and the connecting piece 44 of the strip A, respectively. , 45 are connected.
Note that the outer punching of the saddle part 11 and the connecting part 21 is first performed without performing the outer punching of the saddle part 11, the connecting part 21, and the upper plate part 20 at the same time, and then the outer punching of the upper plate part 20 is performed. It is also possible.
[0016]
Next, the element 10 with the outer shape removed is processed in a press molding process, and the periphery of the element 10 is molded. As shown in FIG. 5, when the saddle portion 11, the connecting portion 21, and the upper plate portion 20 have been removed from the outer shape, burrs 46 are generated around the saddle portion 11, the connecting portion 21, and the upper plate portion 20. . However, the inclined portions 14 and 15 of the saddle portion 11 are portions that contact the V-groove pulley, and the end portions of the saddle portion 11, the connecting portion 21, and the portions forming the parallel groove portions 12 and 13 of the upper plate portion 20 are endless bands. Since it is a mounted part, the generation of burrs 46 and poor dimensional accuracy deteriorate the product quality of the element 10. For this reason, the saddle part 11, the connecting part 21, and the upper plate part 20 are obtained by a finishing die device 49 having a punch 47 and a die 48 having a shape corresponding to the final shape of the element 10 (a shape having rounded corners). Finish processing around. Note that this finishing process can be performed in one step or in two or more steps in consideration of the hardness of the strip A and the shape accuracy of the element 10.
Moreover, after performing the punching process which performs the outer shape punching of the saddle part 11 and the connection part 21, and performing the press molding process process which performs the finishing process of the saddle part 11 and the connection part 21, the outer shape punching of the upper board part 20 is performed. It is also possible to perform a press forming process that performs a punching process and finishes the upper plate portion 20.
[0017]
After the press molding process is completed, the heat treatment process is performed in a state where the element 10 is partially fixed to the strip A via the connecting pieces 44 and 45. This heat treatment step is a step of performing quenching or quenching and tempering so that the element 10 has, for example, impact resistance, wear resistance, toughness and the like.
The quenching is performed by heating the strip A to, for example, 750 ° C. or more and forcibly cooling it, although depending on the temperature at which part thereof becomes austenite, for example, the composition of the strip A. In addition, tempering after quenching is preferably performed in a temperature range in which quenching distortion is removed and solid solution carbon of the punched product is not reduced, for example, 250 ° C. or less.
In addition, since each heating temperature, heating time, cooling time, etc. are well-known techniques if a material is decided, detailed description is abbreviate | omitted. When this heat treatment is performed in a state where all the elements 10 are partially connected to the strip A, a uniform heat treatment can be performed, and further, the operation can be performed continuously.
[0018]
Since the element 10 having the above characteristics can be manufactured by the above processing, the element 10 is separated from the frame portion 43 of the strip A by a punch using a separating device (for example, a trim device). This separation can be easily performed by the punch.
In addition, after the press molding process is completed, it is possible to separate the element 10 from the frame portion 43 of the strip A and perform heat treatment by batch processing.
[0019]
As described above, the present invention has been described with reference to one embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and is described in the claims. Other embodiments and modifications conceivable within the scope of the above are also included. For example, a case where a method for manufacturing an element of a transmission belt for continuously variable transmission according to the present invention is configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the present invention.
Moreover, in the said embodiment, the shape of the board thickness reduction | decrease part of the element demonstrated the case where an inclined surface was provided only in one side surface, and the other was made into the plane continuous to a connection part. However, the shape of the reduced thickness portion of the element is another shape, for example, both the front side and the back side are inclined, or one side is rounded, and the side view is partially circular or partially elliptical. In addition, the thickness of the plate thickness reducing portion can be made thinner than the plate thickness of the connecting portion so that only one side surface has a flat surface continuing to the connecting portion.
[0020]
And in the said embodiment, with respect to the strip material, the plate thickness adjusting process for making the plate thickness at the element punching scheduled positions other than the plate thickness reduced portion substantially uniform, and the portion corresponding to the plate thickness reduced portion The case where the thinning process for reducing the plate thickness is performed at the same time has been described. However, after preparing the molds for plate thickness adjustment processing and thinning processing individually and performing plate thickness adjustment processing at the element punching planned positions other than the plate thickness reduction portion, the part corresponding to the plate thickness reduction portion It is possible to reduce the thickness.
[0021]
【The invention's effect】
In the element manufacturing method of the transmission belt for continuously variable transmission according to claim 1 and 2, since the plate thickness adjustment processing is performed in the press processing step so that the plate thickness at the element punching scheduled position is substantially uniform, The thickness deviation in the plate width direction of the element manufactured through the processing step and the press molding step can be eliminated. As a result, the transmission belt constituted by a large number of elements in a straight line is straight and not bent when seen in a plan view, can enhance the power transmission function, and does not generate noise. Moreover, since generation | occurrence | production of the stress by the bending of a transmission belt can be prevented, the lifetime of a transmission belt can be improved and reliability is also excellent.
Moreover, since plate thickness adjustment processing and thickness reduction processing are performed over the whole plate width direction, an element with excellent shape accuracy is stably manufactured.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram of a pressing process of a method for manufacturing an element of a transmission belt for continuously variable transmission according to an embodiment of the present invention.
FIGS. 2A and 2B are a front view and a plan view of an element manufactured by the same method, respectively.
FIG. 3 is an explanatory diagram of a strip material before and after the press working step of the same method.
FIG. 4 is an explanatory diagram of a punching process of the same method.
FIG. 5 is an explanatory diagram of a press molding process of the same method.
FIGS. 6A and 6B are explanatory diagrams of a continuously variable transmission according to a conventional example, and partially enlarged views of a transmission belt for a continuously variable transmission, respectively.
FIG. 7 is an explanatory diagram when the traveling direction of the transmission belt for the continuously variable transmission changes.
FIG. 8 is an explanatory view showing a state in which a large number of elements constituting the transmission belt for the continuously variable transmission are arranged.
[Explanation of symbols]
10: Element, 11: Saddle part, 12, 13: Parallel groove part (band holding part), 14, 15: Inclined part, 16: Plate thickness reducing part, 17: Midway position, 18, 19: Cut, 20: Upper plate Part, 21: connecting part, 22, 23: oblique side, 24: concave part, 25: convex part, 26-29: relief groove, 30: pressing die device, 31: temporary guide hole, 32: element punching planned position, 33 : Horizontal part, 34: inclined part, 35: punch, 36: die, 37: plate thickness uniform part, 38: inclined processed part, 39: step processed part, 40: stripper, 41: guide hole, 42: punched part, 43: Frame part, 44, 45: Connecting piece, 46: Burr, 47: Punch, 48: Die, 49: Finishing die device

Claims

In use, the saddle portion is provided with inclined portions in contact with the inner wall of the V-groove pulley on both sides, and the lower portion is formed with a reduced thickness portion, and at an upper position of the saddle portion. An upper plate portion provided, and a connecting portion for connecting the upper plate portion and the saddle portion, which are on the left and right sides of the connecting portion and between the saddle portion and the upper plate portion. In the method of punching and forming the element of the transmission belt for continuously variable transmission equipped with a band holding part for attaching a metal endless band from a plate material,
A plate thickness adjusting process for making the plate thickness at the element punching scheduled positions other than at least the plate thickness reduction portion of the plate material substantially uniform, and a plate thickness of a portion corresponding to the plate thickness reduction portion are reduced. A pressing process for pressing the entire plate width direction by means of a punch and a horizontal die with an inclined portion for performing a thinning process, and
From the plate material pressed in the entire plate width direction, the element of the element except for the connecting piece that is provided at the center lower end portion of the saddle portion and the upper end portion of the upper plate portion and connects the element to the frame portion of the plate material . A punching process for punching the outer shape;
A press molding process for molding the peripheral portion of the element whose outer shape has been removed by a finishing mold apparatus ; and
A process of heat-treating the element processed by the press molding process in a state of being connected to the frame portion by the connecting piece;
Separating the element connected to the frame by the connecting piece from the frame, and a method for manufacturing an element of a transmission belt for continuously variable transmission.

2. The element manufacturing method for a transmission belt for continuously variable transmission according to claim 1 , wherein an annealing step for removing internal stress of the plate material is provided between the press working step and the punching step. Manufacturing method of element of transmission belt for step transmission.