JP2004141958A

JP2004141958A - Method for manufacturing element of transmission belt for continuously variable transmission

Info

Publication number: JP2004141958A
Application number: JP2002312624A
Authority: JP
Inventors: Yasumasa Mitsui; 三井　康誠; Takekatsu Fujita; 藤田　剛克; Takashi Matsunaga; 松永　尚
Original assignee: Mitsui High Tec Inc
Current assignee: Mitsui High Tec Inc
Priority date: 2002-10-28
Filing date: 2002-10-28
Publication date: 2004-05-20
Anticipated expiration: 2022-10-28
Also published as: JP4081348B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an element of a transmission belt for a continuously variable transmission which smoothly transmits the power without causing any bend in the transmission belt, enhances the durability of the transmission belt, and prevents generation of noise. <P>SOLUTION: The method for manufacturing an element 10 of a transmission belt for a continuously variable transmission comprising a saddle portion 11 having inclined portions 14 and 15 in contact with an inner wall of a V-groove pulley and a thickness-reduced portion 16 on a lower side portion, and band holding units 12 and 13 formed on an upper side thereof to fit an endless band punching to form, includes a pressing step of performing thickness adjustment of realizing the uniform thickness at a predetermined element punching position of a plate A other than at least the thickness-reduced portion 16, and thickness reduction of reducing the thickness of a portion of the plate corresponding to the thickness-reduced portion 16, a punching step of punching an overall shape of the element 10 out of the plate, and a pressing step of pressing a peripheral portion of the element 10. <P>COPYRIGHT: (C)2004,JPO

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、サドル部の上側位置に形成され、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と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、板材の少なくとも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行うプレス加工工程と、板材からエレメントの外形抜きを行う打抜き加工工程と、外形抜きされたエレメントの周辺部の成形を行う押圧成形加工工程とを有する。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とが好ましい。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。
更に、前記実施の形態においては、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った場合について説明したが、板幅方向全体にわたって板厚調整加工した後に、所定箇所を減肉加工してもよい。また、少なくとも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うことも可能である。例えば、板厚減少部以外のエレメントの輪郭と実質的に同じ形状のパンチや、それより大きな形状のパンチを使用して板厚調整加工を行うことが可能である。なお、板厚減少部を含めたエレメントの打抜き予定位置に板厚調整加工を行う場合は、板厚調整加工を行った後に、板厚減少部に対応する部分に減肉加工を行う。
【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。
特に、請求項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、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]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for 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. 6 (A), in a continuously variable transmission 80 such as an automobile, a transmission belt 83 is used for transmitting power between a V-shaped driving pulley 81 and a driven pulley 82 having a variable groove width. Have been. As shown in FIG. 6B, the transmission belt 83 is composed of metal endless bands 84 and 85 and a number of elements 86 between which the endless bands 84 and 85 are sandwiched from both sides. In this case, by rotating the transmission belt 83 over the driving pulley 81 and the driven pulley 82, the rotational force of the driving pulley 81 is transmitted to the driven pulley 82 via the transmission belt 83.
At this time, since the transmission belt 83 changes the traveling direction to the driven pulley 82 through the driving pulley 81 or to the driving pulley 81 through the driven pulley 82, each element 86 is smoothly moved. As shown in FIG. 7, it is necessary to reduce the thickness of the lower part of the saddle portion 87 of the element 86 in contact with each of 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 in order to secure strength. As described above, the plate thickness of the element 86 varies within a single product (for example, see Patent Document 1).
The element 86 having such a shape has been manufactured by performing a plurality of punching processes from a plate material.
[0003]
[Patent Document 1]
JP-A-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 above-described elements has advanced rolling technology and the like, since the thickness deviation exists, for example, about 10 μm in the width direction of the plate, the upper plate portion 88 with which the adjacent element 86 contacts, The effect remains on the upper part 89 of the saddle part 87 and the element 86 formed by punching without adjusting the plate thickness of the connecting part 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 connected in series, so that the transmission belt 83 runs from the driving pulley 81 to the driven pulley 82. 8 and when traveling from the driven pulley 82 to the driving pulley 81, if the thickness of the upper portion 89 of the saddle portion 87 of the element 86 is uniform, as indicated by the two-dot chain line in FIG. In addition, the transmission belt 83 is straightened in a plan view, but if, for example, a slight deviation (for example, 10 μm) occurs in the plate width direction, as shown by a solid line in FIG. 83 may be bent, or a stress may be generated due to the bend, and the durability of the transmission belt 83 may be significantly impaired. In addition, there is a problem that this causes noise.
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the power transmission is smoothly performed without bending of the power transmission belt, the durability of the power transmission belt can be increased, and the continuously variable transmission that does not generate noise can be performed. An object of the present invention is to provide a method for manufacturing an element of a power transmission belt for a machine.
[0005]
[Means for Solving the Problems]
According to the method of manufacturing an element of a transmission belt for a continuously variable transmission according to the present invention, the inclined portions contacting the inner wall of the V-groove pulley are provided on both sides, and the lower portion has a plate thickness in use. A transmission for a continuously variable transmission including a saddle portion formed with a reduced thickness portion and a band holding portion formed at an upper position of the saddle portion and used for mounting an endless metal band. In a method of punching and forming an element of a belt from a plate material, a plate thickness adjusting process for making a plate thickness of an element punching expected position other than at least a plate thickness reduced portion of the plate material substantially uniform, and a portion corresponding to the plate thickness reduced portion The method includes a pressing step of performing a thickness reducing process for reducing the thickness of the sheet, a punching step of punching out the outer shape of the element from the plate material, and a press forming step of forming a peripheral portion of the element whose outer diameter has been cut out. As described above, in the pressing process, since the thickness adjusting process for making the thickness of the element punching scheduled position substantially uniform is performed, the width direction of the element manufactured through the punching process and the pressing process is performed. Plate thickness deviation can be eliminated.
Here, in the method for manufacturing an element of the transmission belt for a continuously variable transmission according to the present invention, it is preferable that the thickness adjustment processing and the thickness reduction processing in the pressing step are performed over the entire width of the plate material. Thereby, an element having excellent shape accuracy is manufactured.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.
Here, FIG. 1 is an explanatory view of a press working step of a method for manufacturing a transmission belt element for a continuously variable transmission according to an embodiment of the present invention, and FIGS. 2A and 2B are manufactured by the same method. FIG. 3 is an explanatory view of a strip material before and after a pressing step of the same method, FIG. 4 is an explanatory view of a punching step of the same method, and FIG. 5 is a view of a press forming step of the same method. FIG.
[0007]
First, an element 10 manufactured by applying the method for manufacturing an element of a transmission belt for a continuously variable transmission according to an embodiment of the present invention will be described with reference to FIGS.
The element 10 is made of, for example, carbon tool steel (SK), alloy tool steel (SKS), or other quenched and temperable alloy steel, and has an example of a sheet material having a sheet thickness of 1.8 to 2.5 mm, for example. This is a product that is shaped from a strip material A (see FIG. 1). The element 10 includes a saddle portion 11 and parallel groove portions 12 and 13 which are integrally connected to upper positions of the saddle portion 11 and which are one example of a band holding portion for mounting a metal endless band in use. It has.
[0008]
In use, the saddle portion 11 is provided with linear inclined portions 14 and 15 in contact with the inner wall of the V-groove pulley on both sides, and a reduced thickness portion 16 having a reduced thickness is formed on a lower portion. Have been. The angle of inclination of the inclined portions 14 and 15 matches the angle of inclination of the inner wall of the V-groove pulley using the transmission belt for a continuously variable transmission in an assembled state. As described above, the thickness of the saddle portion 11 from the middle position 17 which is the upper end of the thickness-reducing portion 16 is constant upward, but the thickness gradually decreases from the middle position 17 to the lower side, and the one-sided surface is formed. Is inclined. The thickness of the lower end of the thickness-reduced portion 16, that is, the thickness of the thinnest portion is, for example, 1/3 to 2/3 of the original thickness.
The lower end of the saddle portion 11 is provided with cuts 18 and 19 that are paired with each other in order to reduce the overall weight.
In addition, an upper plate portion 20 having an isosceles triangle with rounded corners and a connecting portion 21 connecting the upper plate portion 20 and the saddle portion 11 are provided at an upper position of the saddle portion 11. Further, parallel grooves 12 and 13 which are examples of the above-described band holding portion are formed on the left and right of the connecting portion 21 and between the saddle portion 11 and the upper plate portion 20, respectively.
[0009]
Each of the oblique sides 22, 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). I have. The concave portion 24 is formed of a circular hole having a circular cross section, and the convex portion 25 is formed of a columnar protrusion having a circular cross section which enters the concave portion 24 of the adjacent element 10 with a small gap. In addition, 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 in the concave portion 24 even if the inclination angle of each element 10 in the stacked state is slightly changed. Has a function of always keeping the attitude of the plurality of stacked elements 10 constant.
In the connecting portion between the connecting portion 21 and the saddle portion 11, partial circular escape grooves 26 and 27 which enter the saddle portion 11 are provided, respectively, and in the connecting portion between the connecting portion 21 and the upper plate portion 20. Are provided with partially circular escape grooves 28 and 29 that enter the upper plate portion 20 side.
[0010]
The right and left parallel grooves 12, 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 made of a material having sufficient strength in this portion and resistant to repeated bending (generally, Steel, also referred to as an endless ring) (see FIG. 6B). Therefore, in the element 10, the shapes of the inclined portions 14, 15 in contact with the V-groove pulley and the parallel grooves 12, 13 in contact with the endless band need to maintain a certain quality.
With this configuration, when the transmission belt for a continuously variable transmission curves along the V-groove pulley, the plate thickness reduction portion 16 engages with the convex portion 25 in the concave portion 24 of each element 10. Each element 10 can be brought into smooth contact (see FIG. 7).
[0011]
Next, a method for manufacturing an element of a transmission belt for a continuously variable transmission according to an embodiment of the present invention will be described.
A method for manufacturing an element of a transmission belt for a continuously variable transmission according to an embodiment of the present invention includes a pressing step, a punching step, a press forming step, and a heat treatment step.
First, as shown in FIGS. 1 and 3, in the pressing process, the pressing die device 30 that performs pressing (coining, crushing) is used to rewind from the reel and to apply to both sides in the plate width direction. The strip material A having the temporary guide holes 31 formed at a predetermined pitch is subjected to a thickness adjustment process and a thinning process, and then wound around a reel to form a coil.
[0012]
The pressing die device 30 includes a horizontal portion 33 for performing a thickness adjustment process for making the thickness of the element punching expected position 32 other than the thickness reduced portion 16 substantially uniform, and a portion corresponding to the thickness reduced portion 16. A punch 35 having an inclined portion 34 for performing a thinning process for reducing the thickness of the plate is provided, and a horizontal die 36 is provided. A strip material A manufactured by a material manufacturer and slit (cut) to a desired size is pressed by the punch 35 and the die 36 of the pressing mold apparatus 30 over the entire width direction of the strip, and the strip material A is formed into a uniform thickness. A stepped portion 39 including the portion 37 and the inclined portion 38 can be formed. The pressing die apparatus 30 is provided with a stripper 40 that moves up and down with respect to the punch 35, and performs a thickness adjustment process and a thickness reduction process on the strip material A by the punch 35 and the die 36, thereby forming a stepped portion. After forming 39, the punch 35 can be easily removed 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 (the oblique line rising 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 expected position 32 other than the plate thickness reduction portion 16 of the strip A. The thickness deviation is eliminated, and the thickness is substantially uniform. In addition, the inclined processed portion 38 (the oblique line rising to the left in FIG. 3) is pressed by the inclined portion 34 of the punch 35 and formed over the entire width direction of the plate including the portion corresponding to the reduced thickness portion 16 of the strip A. Accordingly, the thickness is gradually reduced toward the opposite side of the uniform thickness portion 37 to reduce the thickness.
At this time, the stepped portion 39 on which the plate thickness uniform portion 37 and the inclined portion 38 are formed is slightly hardened, and internal stress is generated.
[0014]
Here, the strip material A that has been subjected to the thickness adjustment processing and the thickness reduction processing in the pressing step may be annealed as necessary to remove the internal stress.
This annealing is preferably performed in a temperature range of, for example, 700 to 850 ° C. In the case of performing a batch process, the strip material A is heat-treated at, for example, 700 to 760 ° C for 1 to 5 hours, and is continuously processed (reel-to-reel). In the case of performing the process using a reel, the strip material A is heat-treated at 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 of the strip A in the plate width direction, and a punching die apparatus is formed from the strip A unwound from the reel. (Not shown), the outer shape of the element 10 is removed.
In this step, the saddle portion 11, the connection portion 21, and the upper plate portion 20 of the element 10 are used for the strip A in which the concave portion 24 and the convex portion 25 are formed in the upper plate portion 20 of the element 10 by a 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 with the punch. The lower end of the center of the saddle portion 11 of the element 10 and the upper end of the upper plate portion 20 of the element 10 formed by the punched portion 42 whose outer shape has been punched out by the punch are respectively provided with the frame portion 43 of the strip A and the connecting piece 44. , 45.
Note that the saddle portion 11, the connecting portion 21, and the upper plate portion 20 are not punched at once, but the saddle portion 11 and the connecting portion 21 are punched out, and then the upper plate portion 20 is punched out. It is also possible.
[0016]
Next, the element 10 whose outer shape has been removed is processed in a press forming step to form a peripheral portion of the element 10. When the outer shape removal of the saddle portion 11, the connecting portion 21, and the upper plate portion 20 is completed, burrs 46 are generated around the saddle portion 11, the connecting portion 21, and the upper plate portion 20, as shown in FIG. . However, each of the inclined portions 14 and 15 of the saddle portion 11 is a portion in contact with the V-groove pulley, and a portion of the saddle portion 11, the connecting portion 21, and the parallel groove portions 12 and 13 of the upper plate portion 20 is an endless band. Since it is the part to be mounted, the generation of burrs 46 and poor dimensional accuracy deteriorate the product quality of the element 10. For this reason, the saddle portion 11, the connecting portion 21, and the upper plate portion 20 are formed by a finishing mold device 49 having a punch 47 and a die 48 having a shape (a shape having rounded corners) corresponding to the final shape of the element 10. Finish processing around. This finishing 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.
Further, a punching process for punching the outer shape of the saddle portion 11 and the connecting portion 21 is performed, and a pressing process for finishing the saddle portion 11 and the connecting portion 21 is performed, and then the outer punching of the upper plate portion 20 is performed. It is also possible to perform a stamping process and a press forming process for finishing the upper plate portion 20.
[0017]
After the completion of the pressing process, a 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 higher, and forcibly cooling it, depending on the temperature at which a part is austenitized, for example, the composition of the strip A. Further, the tempering after quenching is preferably performed in a temperature range in which quenching distortion is removed and the solid solution carbon of the punched product is not reduced, for example, 250 ° C. or lower.
The heating temperature, the heating time, the cooling time, and the like are well-known techniques once the materials are determined, and thus detailed descriptions thereof are omitted. When this heat treatment is performed in a state where all the elements 10 are partially connected to the strip material 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-described 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.
After the pressing process is completed, the element 10 can be cut off from the frame portion 43 of the strip material A, and heat treatment can be performed 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-described embodiment, and is described in the claims. Other embodiments and modifications that can be considered within the scope of the present invention are also included. For example, a case where a method for manufacturing a transmission belt element for a continuously variable transmission of 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.
Further, in the above-described embodiment, a case has been described in which the shape of the plate thickness decreasing portion of the element is such that an inclined surface is provided only on one side and the other is a plane that is continuous with the connecting portion. However, the shape of the reduced thickness portion of the element has another shape, for example, both surfaces on the front side and the back side are inclined surfaces, and one side is chamfered to be partially circular and partially elliptical when viewed from the side. In addition, the thickness of the reduced thickness portion may be made smaller than the thickness of the connecting portion, so that only one side surface may be formed as a flat surface continuous with the connecting portion.
[0020]
And in the said embodiment, with respect to a strip | board material, the thickness adjustment processing which makes the thickness of the element punching scheduled position other than a thickness reduction part substantially uniform, and the part corresponding to a thickness reduction part The case where the thickness reduction processing for reducing the thickness is performed at the same time has been described. However, separate molds for thickness adjustment and thickness reduction are prepared separately, and after performing the thickness adjustment at the element punching scheduled position other than the thickness reduction part, the parts corresponding to the thickness reduction part are It is also possible to perform a thinning process.
Further, in the above embodiment, the case where the thickness adjustment processing and the thickness reduction processing are performed over the entire width direction of the plate has been described. You may. In addition, it is also possible to perform the thickness adjustment processing at least at the element punching scheduled position other than the thickness reduced portion. For example, it is possible to perform the thickness adjustment using a punch having substantially the same shape as the contour of the element other than the thickness reduced portion or a punch having a larger shape. In the case where the thickness adjustment processing is performed at the scheduled punching position of the element including the reduced thickness section, the thickness reduction processing is performed, and then the thickness reduction processing is performed on the portion corresponding to the reduced thickness section.
[0021]
【The invention's effect】
In the method for manufacturing the elements of the transmission belt for a continuously variable transmission according to the first and second aspects, in the pressing step, the thickness adjustment processing for making the thickness of the element punching expected position substantially uniform is performed. It is possible to eliminate the thickness deviation in the plate width direction of the element manufactured through the processing step and the press forming step. As a result, the transmission belt having a large number of continuous elements is straight and has no bending when viewed in plan, so that the power transmission function can be enhanced and no noise is generated. Further, since the generation of stress due to the bending of the power transmission belt can be prevented, the life of the power transmission belt can be increased, and the reliability is also excellent.
In particular, in the method for manufacturing an element of a transmission belt for a continuously variable transmission according to the second aspect, since the thickness adjustment processing and the thickness reduction processing are performed over the entire width direction of the belt, an element having excellent shape accuracy is stably manufactured. Is done.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a press working step of a method for manufacturing an element of a transmission belt for a continuously variable transmission according to an embodiment of the present invention.
FIGS. 2A and 2B are a front view and a plan view, respectively, of an element manufactured by the same method.
FIG. 3 is an explanatory view of a strip before and after a press working step of the method.
FIG. 4 is an explanatory view of a punching step of the method.
FIG. 5 is an explanatory view of a press forming process of the same method.
6A and 6B are an explanatory view of a continuously variable transmission according to a conventional example and a partially enlarged view of a transmission belt for a continuously variable transmission.
FIG. 7 is an explanatory diagram when the traveling direction of the transmission belt for a continuously variable transmission changes.
FIG. 8 is an explanatory view showing a state in which a 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 reduction part, 17: Middle position, 18, 19: Cut, 20: Upper plate Part, 21: connecting part, 22, 23: oblique side, 24: concave part, 25: convex part, 26 to 29: relief groove, 30: pressing die device, 31: temporary guide hole, 32: scheduled element punching position, 33 : Horizontal portion, 34: inclined portion, 35: punch, 36: die, 37: uniform thickness portion, 38: inclined portion, 39: stepped portion, 40: stripper, 41: guide hole, 42: punched portion, 43: frame part, 44, 45: connecting piece, 46: burr, 47: punch, 48: die, 49: finishing mold device

Claims

In use, an inclined portion in contact with the inner side wall of the V-groove pulley is provided on both sides, and a saddle portion having a reduced thickness portion formed in a lower portion at a lower portion, and an upper position of the saddle portion. In the method of punching and forming the element of the transmission belt for a continuously variable transmission having a formed and in use, a band holding portion for mounting a metal endless band,
A thickness adjusting process for making the thickness of the plate material at least at the element punching expected position other than the thickness reducing portion substantially uniform, and a thickness reducing process for reducing a thickness of a portion corresponding to the thickness reducing portion. Press working process,
A punching process for punching the outer shape of the element from the plate;
And a press forming step of forming a peripheral portion of the element whose outer shape has been removed. A method of manufacturing an element of a transmission belt for a continuously variable transmission, comprising:

The method for manufacturing an element of a transmission belt for a continuously variable transmission according to claim 1, wherein the thickness adjustment and the thickness reduction in the pressing are performed over the entire width of the plate. For manufacturing a transmission belt element for a continuously variable transmission.