JP2005069244A - Washer, its manufacturing method and automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive synthetic resin thrust washer having superior abrasion resistance and low coefficient of friction, and its manufacturing method, and to provide an automatic transmission contributing on the reduction in size and weight, and the improvement in efficiency. <P>SOLUTION: This washer has a disc-shaped synthetic resin as a base material, its sliding face is coated with a hard carbon thin film, and lubricant and working fluid, including fatty acid ester ashless friction adjusting agent and aliphatic amine ashless friction adjusting agent, are applied to the sliding face. This washer is manufactured by molding the synthetic resin into the shape of the washer, and then coating its surface with diamond-like carbon by a plasma CDV method to form the hard carbon thin film. This automatic transmission applies the washer, and the lubricant and the working fluid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２７】
【化２】

【００２８】
で表される化合物が挙げられる。これら化学式におけるＰＩＢは、ポリブテニル基を示し、高純度イソブテン又は１−ブテンとイソブテンの混合物をフッ化ホウ素系触媒又は塩化アルミニウム系触媒で重合させて得られる数平均分子量が９００〜３５００、望ましくは１０００〜２０００のポリブテンから得られる。上記数平均分子量が９００未満の場合は清浄性効果が劣り易く、３５００を超える場合は低温流動性に劣り易いため、望ましくない。
また、上記化学式におけるｎは、清浄性に優れる点から１〜５の整数、より望ましくは２〜４の整数であることがよい。更に、上記ポリブテンは、製造過程の触媒に起因して残留する微量のフッ素分や塩素分を吸着法や十分な水洗等の適切な方法により、５０ｐｐｍ以下、より望ましくは１０ｐｐｍ以下、特に望ましくは１ｐｐｍ以下まで除去してから用いることもよい。
【００２９】
更に、上記ポリブテニルコハク酸イミドの製造方法としては、特に限定はないが、例えば、上記ポリブテンの塩素化物又は塩素やフッ素が充分除去されたポリブテンと無水マレイン酸とを１００〜２００℃で反応させて得られるポリブテニルコハク酸を、ジエチレントリアミン、トリエチレンテトラミン、テトラエチレンペンタミン、ペンタエチレンヘキサミン等のポリアミンと反応させることにより得ることができる。
【００３０】
一方、上記ポリブテニルコハク酸イミドの誘導体としては、上記化学式（１）又は（２）で表される化合物に、ホウ素化合物や含酸素有機化合物を作用させて、残存するアミノ基及び／又はイミノ基の一部又は全部を中和したり、アミド化した、いわゆるホウ素変性又は酸変性化合物を例示できる。その中でもホウ素含有ポリブテニルコハク酸イミド、特にホウ素含有ビスポリブテニルコハク酸イミドが最も好ましいものとして挙げられる。
【００３１】
上記ホウ素化合物としては、ホウ酸、ホウ酸塩、ホウ酸エステル等が挙げられる。具体的には、上記ホウ酸として、オルトホウ酸、メタホウ酸及びテトラホウ酸などが挙げられる。また、上記ホウ酸塩としては、アンモニウム塩等、具体的には、例えばメタホウ酸アンモニウム、四ホウ酸アンモニウム、五ホウ酸アンモニウム、八ホウ酸アンモニウム等のホウ酸アンモニウムが好適例として挙げられる。また、ホウ酸エステルとしては、ホウ酸と好ましくは炭素数１〜６のアルキルアルコールとのエステル、より具体的には例えば、ホウ酸モノメチル、ホウ酸ジメチル、ホウ酸トリメチル、ホウ酸モノエチル、ホウ酸ジエチル、ホウ酸トリエチル、ホウ酸モノプロピル、ホウ酸ジプロピル、ホウ酸トリププロピル、ホウ酸モノブチル、ホウ酸ジブチル、ホウ酸トリブチル等が好適例として挙げられる。なお、ホウ素含有ポリブテニルコハク酸イミドにおけるホウ素含有量Ｂと窒素含有量Ｎとの質量比「Ｂ／Ｎ」は、通常０．１〜３であり、好ましくは、０．２〜１である。
また、上記含酸素有機化合物としては、具体的には、例えばぎ酸、酢酸、グリコール酸、プロピオン酸、乳酸、酪酸、吉草酸、カプロン酸、エナント酸、カプリル酸、ペラルゴン酸、カプリン酸、ウンデシル酸、ラウリン酸、トリデカン酸、ミリスチン酸、ペンタデカン酸、パルミチン酸、マルガリン酸、ステアリン酸、オレイン酸、ノナデカン酸、エイコサン酸等の炭素数１〜３０のモノカルボン酸や、シュウ酸、フタル酸、トリメリット酸、ピロメリット酸等の炭素数２〜３０のポリカルポン酸並びにこれらの無水物、又はエステル化合物、炭素数２〜６のアルキレンオキサイド、ヒドロキシ（ポリ）オキシアルキレンカーボネート等が挙げられる
【００３２】
なお、本発明に用いる作動油において、ポリブテニルコハク酸イミド及び／又はその誘導体の含有量は特に制限されないが、０．１〜１５％が望ましく、より望ましくは１．０〜１２％であることが好ましい。０．１％未満では清浄性効果に乏しくなることがあり、１５％を超えると含有量に見合う清浄性効果が得られにくく、抗乳化性が悪化し易い。
【００３３】
更にまた、本発明に用いる潤滑油、作動油のいずれか一方又は双方は、次の化学式（３）
【００３４】
【化３】

【００３５】
で表されるジチオリン酸亜鉛を含有することが好適である。
上記化学式（３）中のＲ^４、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ別個に炭素数１〜２４の炭化水素基を示す。これら炭化水素基としては、炭素数１〜２４の直鎖状又は分枝状のアルキル基、炭素数３〜２４の直鎖状又は分枝状のアルケニル基、炭素数５〜１３のシクロアルキル基又は直鎖状若しくは分枝状のアルキルシクロアルキル基、炭素数６〜１８のアリール基又は直鎖状若しくは分枝状のアルキルアリール基、炭素数７〜１９のアリールアルキル基等のいずれかであることが望ましい。また、アルキル基やアルケニル基は、第１級、第２級及び第３級のいずれであってもよい。
【００３６】
上記Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７としては、具体的には、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、へキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基、ノナデシル基、イコシル基、ヘンイコシル基、ドコシル基、トリコシル基、テトラコシル基等のアルキル基、プロペニル基、イソプロペニル基、ブテニル基、ブタジエニル基、ペンテニル基、ヘキセニル基、ヘプテニル基、オクテニル基、ノネニル基、デセニル基、ウンデセニル基、ドデセニル基、トリデセニル基、テトラデセニル基、ペンタデセニル基、ヘキサデセニル基、ヘプタデセニル基、オレイル基等のオクタデセニル基、ノナデセニル基、イコセニル基、ヘンイコセニル基、ドコセニル基、トリコセニル基、テトラコセニル基等のアルケニル基、シクロペンチル基、シクロへキシル基、シクロヘプチル基等のシクロアルキル基、メチルシクロペンチル基、ジメチルシクロペンチル基、エチルシクロペンチル基、プロピルシクロペンチル基、エチルメチルシクロペンチル基、トリメチルシクロペンチル基、ジエチルシクロペンチル基、エチルジメチルシクロペンチル基、プロピルメチルシクロペンチル基、プロピルエチルシクロペンチル基、ジ−プロピルシクロペンチル基、プロピルエチルメチルシクロペンチル基、メチルシクロへキシル基、ジメチルシクロへキシル基、エチルシクロへキシル基、プロピルシクロへキシル基、エチルメチルシクロへキシル基、トリメチルシクロへキシル基、ジエチルシクロヘキシル基、エチルジメチルシクロヘキシル基、プロピルメチルシクロヘキシル基、プロピルエチルシクロヘキシル基、ジ−プロピルシクロへキシル基、プロピルエチルメチルシクロヘキシル基、メチルシクロヘプチル基、ジメチルシクロヘプチル基、エチルシクロヘプチル基、プロピルシクロヘプチル基、エチルメチルシクロヘプチル基、トリメチルシクロヘプチル基、ジエチルシクロヘプチル基、エチルジメチルシクロヘプチル基、プロピルメチルシクロヘプチル基、プロピルエチルシクロヘプチル基、ジ−プロピルシクロヘプチル基、プロピルエチルメチルシクロヘプチル基等のアルキルシクロアルキル基、フェニル基、ナフチル基等のアリール基、トリル基、キシリル基、エチルフェニル基、プロピルフェニル基、エチルメチルフェニル基、トリメチルフェニル基、ブチルフェニル基、プロピルメチルフェニル基、ジエチルフェニル基、エチルジメチルフェニル基、テトラメチルフェニル基、ペンチルフェニル基、ヘキシルフェニル基、ヘプチルフェニル基、オクチルフェニル基、ノニルフェニル基、デシルフェニル基、ウンデシルフェニル基、ドデシルフェニル基等のアルキルアリール基、ベンジル基、メチルベンジル基、ジメチルベンジル基、フェネチル基、メチルフェネチル基、ジメチルフェネチル基等のアリールアルキル基、等が例示できる。
なお、Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７がとり得る上記炭化水素基には、考えられる全ての直鎖状構造及び分枝状構造をが含まれ、また、アルケニル基の二重結合の位置、アルキル基のシクロアルキル基への結合位置、アルキル基のアリール基への結合位置、及びアリール基のアルキル基への結合位置は任意である。また、上記炭化水素基の中でも、その炭化水素基が、直鎖状又は分柱状の炭素数１〜１８のアルキル基である場合若しくは炭素数６〜１８のアリール基、又は直鎖状若しくは分枝状アルキルアリール基である場合が特に好ましい。
【００３７】
上記ジチオリン酸亜鉛の好適な具体例としては、例えば、ジイソプロピルジチオリン酸亜鉛、ジイソブチルジチオリン酸亜鉛、ジ−ｓｅｃ−ブチルジチオリン酸亜鉛、ジ−ｓｅｃ−ペンチルジチオリン酸亜鉛、ジ−ｎ−ヘキシルジチオリン酸亜鉛、ジ−ｓｅｃ−ヘキシルジチオリン酸亜鉛、ジ−オクチルジチオリン酸亜鉛、ジ−２−エチルヘキシルジチオリン酸亜鉛、ジ−ｎ−デシルジチオリン酸亜鉛、ジ−ｎ−ドデシルジチオリン酸亜鉛、ジイソトリデシルジチオリン酸亜鉛、及びこれらの任意の組合せに係る混合物等が挙げられる。
【００３８】
また、上記ジチオリン酸亜鉛の含有量は、特に制限されないが、より高い摩擦低減効果を発揮させる観点から、潤滑油及び／又は作動油の全量基準且つリン元素換算量で、０．１％以下であることが好ましく、また０．０６％以下であることがより好ましく、更にはジチオリン酸亜鉛が含有されないことが特に好ましい。ジチオリン酸亜鉛の含有量がリン元素換算量で０．１％を超えると、ＤＬＣ部材と鉄基部材との摺動面における上記脂肪酸エステル系無灰摩擦調整剤や上記脂肪族アミン系無灰摩擦調整剤の優れた摩擦低減効果が阻害されるおそれがある。
【００３９】
上記ジチオリン酸亜鉛の製造方法としては、従来方法を任意に採用することができ、特に制限されないが、具体的には、例えば、上記Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７に対応する炭化水素基を持つアルコール又はフェノールを五二硫化りんと反応させてジチオリン酸とし、これを酸化亜鉛で中和させることにより合成することができる。なお、上記ジチオリン酸亜鉛の構造は、使用する原料アルコールによって異なることは言うまでもない。
本発明においては、上記化学式（３）に包含される２種以上のジチオリン酸亜鉛を任意の割合で混合して使用することもできる。
【００４０】
上述のように、本発明に使用する作動油は、ＤＬＣなどの硬質炭素薄膜との摺動面に用いた場合に、極めて優れた低摩擦特性を示すものであるが、特に自動変速機の作動油として必要な性能を高める目的で、金属系清浄剤、酸化防止剤、粘度指数向上剤、他の無灰摩擦調整剤、他の無灰分散剤、磨耗防止剤若しくは極圧剤、防錆剤、非イオン系界面活性剤、抗乳化剤、金属不活性化剤、消泡剤等を単独で又は複数種を組合せて配合し、必要な性能を高めることができる。
【００４１】
上記金属系清浄剤としては、潤滑油などの金属系清浄剤として通常用いられる任意の化合物が使用できる。例えば、アルカリ金属又はアルカリ土類金属のスルホネート、フェネート、サリシレート、ナフテネート等を単独で又は複数種を組合せて使用できる。ここで、上記アルカリ金属としてはナトリウム（Ｎａ）やカリウム（Ｋ）等、上記アルカリ土類金属としてはカルシウム（Ｃａ）やマグネシウム（Ｍｇ）等が例示できる。また、具体的な好適例としては、Ｃａ又はＭｇのスルフォネート、フェネート及びサリシレートが挙げられる。
なお、これら金属系清浄剤の全塩基価及び添加量は、要求される作動油の性能に応じて任意に選択できる。通常、全塩基価は、過塩素酸法で０〜５００ｍｇＫＯＨ／ｇ、望ましくは１５０〜４００ｍｇＫＯＨ／ｇであり、その添加量は潤滑油及び／又は作動油の全量基準で、通常０．１〜１０％である。
【００４２】
また、上記酸化防止剤としては、潤滑油などの酸化防止剤として通常用いられる任意の化合物を使用できる。例えば、４，４’−メチレンビス（２，６−ジ−ｔｅｒｔ−ブチルフェノール）、オクタデシル−３−（３，５−ジ−ｔｅｒｔ−ブチル−４−ヒドロキシフェニル）プロピオネート等のフェノール系酸化防止剤、フェニル−α−ナフチルアミン、アルキルフェニル−α−ナフチルアミン、アルキルジフェニルアミン等のアミン系酸化防止剤、並びにこれらの任意の組合せに係る混合物等が挙げられる。また、かかる酸化防止剤の添加量は、潤滑油及び／又は作動油の全量基準で、通常０．０１〜５％である。
【００４３】
更に、上記粘度指数向上剤としては、具体的には、各種メタクリル酸エステルから選ばれる１種又は２種以上のモノマーの共重合体やその水添物等のいわゆる非分散型粘度指数向上剤、及び更に窒素化合物を含む各種メタクリル酸エステルを共重合させたいわゆる分散型粘度指数向上剤等が例示できる。また、他の粘度指数向上剤の具体例としては、非分散型又は分散型エチレン−α−オレフィン共重合体（α−オレフィンとしては、例えばプロピレン、１−ブテン、１−ペンテン等）及びその水素化物、ポリイソブチレン及びその水添物、スチレン−ジエン水素化共重合体、スチレン−無水マレイン酸エステル共重合体、並びにポリアルキルスチレン等も例示できる。
これら粘度指数向上剤の分子量は、せん断安定性を考慮して選定することが必要である。具体的には、粘度指数向上剤の数平均分子量は、例えば分散型及び非分散型ポリメタクリレートでは５０００〜１００００００、好ましくは１０００００〜８０００００がよく、ポリイソブチレン又はその水素化物では８００〜５０００、エチレン−α−オレフィン共重合体又はその水素化物では８００〜３０００００、好ましくは１００００〜２０００００がよい。また、かかる粘度指数向上剤は、単独で又は複数種を任意に組合せて含有させることができるが、通常その含有量は、作動油全量基準で０．１〜４０．０％であることが望ましい。
【００４４】
更にまた、他の無灰摩擦調整剤としては、ホウ酸エステル、高級アルコール、脂肪族エーテル等の無灰摩擦調整剤、ジチオリン酸モリブデン、ジチオカルバミン酸モリブデン、二硫化モリブデン等の金属系摩擦調整剤等が挙げられる。
また、他の無灰分散剤としては、数平均分子量が９００〜３５００のポリブテニル基を有するポリブテニルベンジルアミン、ポリブテニルアミン、数平均分子量が９００未満のポリブテニル基を有するポリブテニルコハク酸イミド等及びそれらの誘導体等が挙げられる。
【００４５】
更に、上記磨耗防止剤又は極圧剤としては、ジスルフィド、硫化油脂、硫化オレフィン、炭素数２〜２０の炭化水素基を１〜３個含有するリン酸エステル、チオリン酸エステル、亜リン酸エステル、チオ亜リン酸エステル及びこれらのアミン塩等が挙げられる。
更にまた、上記防錆剤としては、アルキルベンゼンスルフォネート、ジノニルナフタレンスルフォネート、アルケニルコハク酸エステル、多価アルコールエステル等が挙げられる。
【００４６】
また、上記非イオン系界面活性剤及び抗乳化剤としては、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンアルキルナフチルエーテル等のポリアルキレングリコール系非イオン系界面活性剤等が挙げられる。
更に、上記金属不活性化剤としては、イミダゾリン、ピリミジン誘導体、チアジアゾール、ベンゾトリアゾール、チアジアゾール等が挙げられる。
更にまた、上記消泡剤としては、シリコーン、フルオロシリコーン、フルオロアルキルエーテル等が挙げられる。
【００４７】
なお、上記各添加剤を本発明に用いる作動油に含有させる場合には、その含有量は、作動油全量基準で、他の摩擦調整剤、他の無灰分散剤、磨耗防止剤又は極圧剤、防錆剤、及び抗乳化剤については０．０１〜５％、金属不活性剤については０．００５〜１％、消泡剤については０．０００５〜１％の範囲から適宜選択できる。
【００４８】
以上に説明した本発明のワッシャは、金属製部品又はセラミックス製部品を摺動相手材として使用されることが好ましく、更にこの摺動相手材の摺動面の表面粗さは、Ｒｚ（ＪＩＳ Ｂ ０６０１−２００１の最大平均粗さ）で２μｍ以下であることが好ましい。これより、長期に亘って安定な摺動状態が維持され易い。なお、摺接面のＲｚが２μｍを超えると、摺接面により硬質炭素薄膜が基材から剥離し易くなり、硬質炭素薄膜によるフリクション低減効果及び耐摩擦性向上効果が得られなくなることがある。
また、摺動相手材の材質としては、例えば炭素鋼、ステンレス鋼、鋳鉄等の金属材料や、ＳｉＣ、ＴｉＣ、Ａｌ_２Ｏ_３等のセラミックス材料などが挙げられる。
【００４９】
次に、本発明のワッシャの製造方法について、更に詳細に説明する。
本製造方法では、合成樹脂をワッシャ形状に成形後、その表面にプラズマＣＤＶ法によりダイヤモンドライクカーボンを被覆して硬質炭素薄膜を設けてワッシャを得る。このとき、硬質炭素薄膜は、合成樹脂表面の全体に必ずしも被覆しなくて良く、高圧負荷のかかる部位のみに被覆しても良い。
また、硬質炭素薄膜を被覆する前の合成樹脂表面は、摺動相手材への攻撃性を抑制する観点から、表面粗さがＪＩＳ Ｂ ０６０１−２００１の算術平均粗さＲａで５．０μｍ以下であることが望ましい。
更に、硬質炭素薄膜の厚さは、０．０１〜１μｍとすることが望ましい。
【００５０】
次に、本発明の自動変速装置について、更に詳細に説明する。
本発明の自動変速装置は、上述のワッシャと潤滑油及び／又は作動油を用いて構成される。このため、相手材側の摩耗量が大幅に軽減されることから、自動変速装置の小型化、軽量化が達成され、更には効率が向上する。
【００５１】
図２は、ワッシャを組み込んだ自動車用自動変速機の構造を示す断面図であって、自動車の流体式トルクコンバータの要部に油中スラストワッシャ１と、これより小径の油中スラストワッシャ９と、両面に突起を有しない油中スラストワッシャ１０を装着した状態を示す。
このトルクコンバータの要部は、タービン側のボス１１とインペラ側のハブ１２の間で回転動力（トルク）を伝達する。そして、油中スラストワッシャ１０は、コンバータカバー１３とタービンハブ１４とのスラスト力を受け持ちまた摺接し、油中スラストワッシャ９は、タービンハブ１４とワンウェイクラッチ１５のタービン側面部材１６とのスラスト力を受け持ちまた摺接し、そして、油中スラストワッシャ１は、ワンウェイクラッチ１５のインペラ側面部材１７とインペラ側のハブ１８とのスラスト力を受け持ちまた摺接する。
【００５２】
【実施例】
以下、本発明を実施例と比較例によって、更に具体的に説明するが、本発明は、これら実施例のみに限定されるものではない。
【００５３】
（作動油の調整）
〔１〕作動油Ａ
ベースオイルとしてのポリアルファオレフィン（１−オクテンオリゴマー）に、エステル系無灰摩擦調整剤としてグリセリンモノオレートを１．０％、無灰系分散剤としてポリブテニルコハク酸イミドを５．０％、その他添加剤として粘度指数向上剤、酸化防止剤、防錆剤、抗乳化剤、非イオン系界面活性剤、金属不活性化剤、消泡剤等を合計で７．０％それぞれ添加し、作動油Ａとした。
〔２〕作動油Ｂ
ベースオイルとしてのポリアルファオレフィン（１−オクテンオリゴマー）のみから成る作動油を調整し、作動油Ｂとした。
【００５４】
（実施例１）
事前にガラス繊維３３％をコンパウンドさせたポリアミド６６樹脂（ザイテル７０Ｇ３３ＨＳ１Ｌ デゥポン社製）のペレットを乾燥後、射出成形機を用いて、図３に示すような、ワッシャ試験片１０を成形した。その後、このワッシャ試験片１０の側面を研磨して表面粗さＲａを３μｍ程度とした。
次に、プラズマＣＶＤ装置にワッシャ試験片１０を入れ、真空に引いた後、Ｈ_２プラズマにより成膜面であるワッシャ試験片側面の洗浄後、ＣＨ_４プラズマにより硬質炭素薄膜を成膜した。なお、硬質炭素薄膜の膜厚は０．７〜０．８μｍとした。
リング試験片及び作動油Ａを用いて後述する摩耗試験を行った。
【００５５】
（実施例２）
事前にガラス繊維３０％をコンパウンドさせたポリエーテルエーテルケトン樹脂（ビクトレックスエムシー社製 ４５０ＧＬ３０）のペレットを用いた以外は、実施例１と同様の操作を繰り返して、ワッシャ試験片を得た。また、同様に後述する摩耗試験を行った。
【００５６】
（比較例１）
実施例１と同様の操作を繰り返して、ワッシャ試験片を得た。また、作動油Ｂを用いた以外は実施例１と同様に後述する摩耗試験を行った。
【００５７】
（比較例２）
実施例２と同様の操作を繰り返して、ワッシャ試験片を得た。また、作動油Ｂを用いた以外は実施例１と同様に後述する摩耗試験を行った。
【００５８】
（比較例３）
硬質炭素薄膜を設けないこと以外は、実施例１と同様の操作を繰り返して、ワッシャ試験片を得た。また、実施例１と同様に後述する摩耗試験を行った。
【００５９】
（性能評価）
本発明の摺動特性改善効果を確認するため、ワッシャ試験片を用いた摩耗試験を油中で実施した。摺接する相手材としては一般的な炭素鋼（Ｓ５５Ｃ調質材 ＨＲＡ＝７０）を選定した。試験装置に取り付けるため炭素鋼の試験片形状は、直径６０ｍｍ、厚さ１０ｍｍのディスク３８とし、摺接面の表面粗さはＲｚ（最大粗さ）＝２μｍとした。
【００６０】
この摩耗試験に使用した縦型ピンオンディスク方式の摩擦摩耗試験機の概要を図４に示す。
当該試験機は、上部にリングホルダー３４を有し、このリングホルダー３４は、摺動時にワッシャ試験片１０の径方向の移動が生じないように、ワッシャ試験片内周面側に設置したスナップリング３５のバネ力によって、ワッシャ試験片外周面をホルダー溝部に押し付けて固定するようになっている。
一方、当該試験機の下部には回転軸４０に結合されたディスクホルダー３９を備え、ディスク３８をディスクホルダー３９にボルトで固定すると、ディスク３８はワッシャ試験片１０に対して回転自在となる。次に、リングホルダー３４を下降させることでワッシャ試験片１０とディスク３８を摺接関係とさせ、さらにリングホルダー３４の軸線方向から圧力Ｐを加えることによって、ワッシャ試験片１０とディスク３８とが圧接することになる。この際、ワッシャ試験片１０とディスク３８の摺接部は、作動油４１中に浸漬されている。なお、符号３６はロードセル、符号３７はトルク検出器を示している。
【００６１】
上記試験機を用いて、圧接面圧：３ＭＰａ、摩擦速度：１０ｍ／秒、試験時間：６時間の試験条件で行った摩耗試験の結果を表１に示す。
【００６２】
【表１】

【００６３】
表１より、本発明の模擬実施形態である、実施例１及び２に係るワッシャ試験片及び作動油の組み合わせは、優れた低摩擦特性を示すことが明らかである。
【００６４】
【発明の効果】
以上説明してきたように、本発明によれば、ワッシャの摺動面を硬質炭素薄膜で被覆すると共に、潤滑油や作動油に特定の無灰摩擦調整剤を添加することとしたため、低コストで且つ耐摩耗性と低摩擦係数に優れた合成樹脂製スラストワッシャ及びその製造方法を提供すること、並びに小型化、軽量化及び効率向上に貢献する自動変速装置を提供することができる。
【図面の簡単な説明】
【図１】本発明のワッシャの一例を示す概略図である。
【図２】本発明のワッシャを用いた自動変速装置の一例を示す断面図である。
【図３】実施例において摩耗試験に用いたワッシャ試験片の形状を示す斜視図である。
【図４】実施例において摩耗試験に用いた縦型ピンオンディスク方式の摩擦摩耗試験機の概略図である。
【符号の説明】
１ 油中スラストワッシャ
９ 油中スラストワッシャ（１より小径）
１０ 油中スラストワッシャ（両面に突起を有しない）
１１ タービン側のボス
１２ インペラ側のハブ
１３ コンバータカバー
１４ タービンハブ
１５ ワンウェイクラッチ
１６ タービン側面部材
１７ インペラ側面部材
１８ インペラ側のハブ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a washer, a manufacturing method thereof, and an automatic transmission, and more specifically, a washer that excels in low friction characteristics of a sliding surface and absorbs a rotational difference of a relative rotating portion and a thrust force, a manufacturing method thereof, and The present invention relates to an automatic transmission.
[0002]
[Prior art]
In recent years, in a transmission for an automobile, a thrust needle bearing has been replaced with a synthetic resin thrust washer from the viewpoint of size reduction, weight reduction, and cost reduction. Since resin thrust washers are required to have excellent wear resistance and a low coefficient of friction, countermeasures have conventionally been taken by optimizing the base resin and filler (for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-170397
However, the optimization of the base resin and filler generally involves using expensive materials, so there is a large rebound to the cost. Therefore, the thrust needle bearing is replaced with a synthetic resin thrust washer. However, the cost merit is greatly reduced.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of such problems of the prior art, and an object of the present invention is a synthetic resin thrust washer that is low in cost and excellent in wear resistance and a low friction coefficient, and its manufacture. It is an object of the present invention to provide a method and an automatic transmission that contributes to reduction in size, weight, and efficiency.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the inventors have coated the washer sliding surface with a hard carbon thin film and added a specific ashless friction modifier to the lubricating oil or hydraulic oil. Thus, it has been found that the friction torque at the sliding contact portion with the mating member can be reduced, and the present invention has been completed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail. In the present specification, “%” indicates mass percentage unless otherwise specified.
[0008]
The washer of the present invention comprises a disc-shaped synthetic resin as a base material and a sliding surface covered with a hard carbon thin film. With such a configuration, the friction torque of the sliding contact portion with the counterpart member is reduced. For example, a washer as shown in FIG.
[0009]
Here, as the hard carbon thin film, for example, a DLC material mainly composed of carbon atoms can be used. For example, the hard carbon thin film can be formed by a plasma CVD method.
This DLC material is amorphous, and the bonding form between carbons consists of both a diamond structure (SP ³ bond) and a graphite bond (SP ² bond). Specifically, aC (amorphous carbon) consisting only of carbon elements, aC: H (hydrogen amorphous carbon) containing hydrogen, and some metal elements such as titanium (Ti) and molybdenum (Mo). MeC contained in can be preferably used.
[0010]
In addition, the synthetic resin used as the base material (base material) of the washer of the present invention is typically a resin having a heat resistance that is increasingly demanded as a thrust washer, specifically a resin having a heat resistance of 150 ° C. or higher. Desirably, it is also desirable to have excellent wear resistance.
Examples of such resins include polyamide resins, polyester resins, polyphenylene sulfide resins, polyether sulfone resins, polyamide imide resins, polyether imide resins, polyether ether ketone resins, polyimide resins or phenol resins, and any of these. Combinations can be mentioned. When such a resin is used, the risk of softening and erosion can be reduced.
[0011]
Other resins, alumina powder or graphite powder as a filler, glass fiber or carbon fiber as a fiber reinforcement, bronze powder or stainless steel powder as a metal powder for improving heat dissipation are added to the resin. However, from the viewpoint of ensuring moldability and workability for forming a washer shape, it is desirable that the content of the thermoplastic resin having a melting point of 150 ° C. or higher is at least 40%.
[0012]
Accordingly, the washer according to the present invention has, for example, a disk-shaped member containing the above resin as a base material, and at least one of the inner peripheral surface, outer peripheral surface, and both side surfaces of the base material, specifically, at least the counterpart member Can be manufactured by forming a DLC film on the slidable contact surface by a plasma CVD method.
[0013]
The washer of the present invention is used with either or both of lubricating oil and hydraulic oil interposed on the sliding surface. Accordingly, the low friction characteristic is excellent, and the rotation difference of the relative rotating part and the absorption of the thrust force are excellent. As the lubricating oil or hydraulic oil, a base oil (base oil) containing either or both of a fatty acid ester-based ashless friction modifier and an aliphatic amine-based ashless friction modifier is used.
[0014]
Here, the base oil is not particularly limited, and any base oil can be used as long as it is normally used as a base oil for hydraulic oil such as mineral oil, synthetic oil, fats and oils, and mixtures thereof. Can do.
Specifically, as mineral oil, the working oil fraction obtained by atmospheric distillation and vacuum distillation of crude oil can be desolvated, solvent extraction, hydrocracking, solvent dewaxing, hydrorefining, sulfuric acid washing, clay Oils such as paraffinic or naphthenic oils or normal paraffins, etc., which are refined by appropriately combining purification treatments, etc., can be used. Solvent refining and hydrorefining treatments are generally used, but the aromatic content is further reduced. It is more preferable to use an advanced hydrocracking process that can be carried out or a GTL Wax (gas tow liquid wax) produced by isomerization.
[0015]
Specific examples of synthetic oils include poly-α-olefins (eg, 1-octene oligomers, 1-decene oligomers, ethylene-propylene oligomers), poly-α-olefin hydrides, isobutene oligomers, and isobutene oligomers. Hydride, isoparaffin, alkylbenzene, alkylnaphthalene, diester (eg, ditridecyl glutarate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, dioctyl sebacate, etc.), polyol ester (eg, trimethylolpropane caprylate, trimethylolpropane pelargol And trimethylolpropane esters such as trimethylolpropane isostearinate; pentaerythritol 2-ethylhexanoate, pentaerythritol Pentaerythritol esters such as largonate), polyoxyalkylene glycols, dialkyldiphenyl ethers, polyphenyl ethers and the like. Among them, preferred examples include poly-α-olefins such as 1-octene oligomers and 1-decene oligomers or hydrides thereof.
[0016]
The base oil may be a mixture of two or more kinds of mineral base oils or two or more kinds of synthetic base oils, in addition to using a mineral base oil or a synthetic base oil alone or in combination. . Further, the mixing ratio of two or more kinds of base oils in the above mixture is not particularly limited and can be arbitrarily selected.
[0017]
Although there is no restriction | limiting in particular about the sulfur content in the said base oil, It is preferable that it is 0.2% or less on a base oil whole quantity basis, More preferably, it is 0.1% or less, Furthermore, it is 0.05% or less. It is preferable. In particular, since the sulfur content of hydrorefined mineral oil or synthetic base oil is 0.005% or less, or contains substantially no sulfur content (5 ppm or less), these are preferably used as the base oil.
[0018]
Also, the aromatic content in the base oil is not particularly limited. For example, in order to maintain a low friction characteristic for a long period of time as a hydraulic oil for an automobile automatic transmission, the total aromatic content is 15% or less. More preferably, it is preferably 10% or less, more preferably 5% or less. That is, when the total aromatic content of the hydraulic oil base oil exceeds 15%, oxidation stability is inferior, which is not preferable.
In addition, the total aromatic content said here means the aromatic fraction content measured based on the method prescribed | regulated to ASTMD2549.
[0019]
The kinematic viscosity of the base oil is not particularly limited, but when used as a hydraulic oil for an automatic transmission as described above, the kinematic viscosity at 100 ° C. is preferably 2 mm ² / s or more, more preferably. Is 3 mm ² / s or more. On the other hand, the kinematic viscosity is preferably 20 mm ² / s or less, preferably 10 mm ² / s or less, and particularly preferably 8 mm ² / s or less. When the kinematic viscosity at 100 ° C. of the base oil is less than 2 mm ² / s, it is not preferable because sufficient wear resistance cannot be obtained and the evaporation characteristics may be inferior. On the other hand, when the kinematic viscosity exceeds 20 mm ² / s, it is difficult to exhibit low friction performance, and low temperature performance may be deteriorated. In the present invention, a mixture of any two or more base oils selected from the above base oils can be used, and the base oil alone is used as long as the kinematic viscosity at 100 ° C. falls within the above preferred range. Even if the kinematic viscosity is other than the above, it can be used.
[0020]
Further, the viscosity index of the base oil is not particularly limited, but is preferably 80 or more, more preferably 100 or more, particularly 120 or more when used as hydraulic oil for an automatic transmission. It is preferable that By increasing the viscosity index of the base oil, it is possible to obtain a lubricating oil or hydraulic oil with less oil consumption and excellent low-temperature viscosity characteristics and fuel saving performance.
[0021]
The fatty acid ester ashless friction modifier and / or the aliphatic amine ashless friction modifier is a straight chain having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms, and particularly preferably 10 to 20 carbon atoms. Or the fatty acid ester which has a branched hydrocarbon group, a fatty-acid amine compound, and these arbitrary mixtures can be mentioned. When the carbon number is outside the range of 6 to 30, there is a possibility that the friction reducing effect cannot be obtained sufficiently.
[0022]
Specific examples of the straight chain or branched hydrocarbon group having 6 to 30 carbon atoms include hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group. Group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triaconyl group, etc. Alkyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icosenyl group, N'ikoseniru group include docosenyl, tricosenyl group, tetracosenyl group, Pentakoseniru group, Hekisakoseniru group, Heputakoseniru group, Okutakoseniru group, Nonakoseniru group, an alkenyl group such as tri container group.
The alkyl group and alkenyl group include all possible linear structures and branched structures, and the position of the double bond in the alkenyl group is arbitrary.
[0023]
Moreover, as said fatty acid ester, the ester of the fatty acid which has this C6-C30 hydrocarbon group, and aliphatic monohydric alcohol or aliphatic polyhydric alcohol etc. can be illustrated, Specifically, glycerol monooleate, Particularly preferred examples include glycerine diolate, sorbitan monooleate, sorbitan diolate, and the like.
Examples of the aliphatic amine compound include aliphatic monoamines or their alkylene oxide adducts, aliphatic polyamines, imidazoline compounds, and derivatives thereof. Specifically, fats such as laurylamine, lauryldiethylamine, lauryldiethanolamine, dodecyldipropanolamine, palmitylamine, stearylamine, stearyltetraethylenepentamine, oleylamine, oleylpropylenediamine, oleyldiethanolamine, N-hydroxyethyloleylimidazoline, etc. Amine alkylene compounds, amine alkylene oxide adducts such as N, N-dipolyoxyalkylene-N-alkyl (or alkenyl) (carbon number 6 to 28) of these aliphatic amine compounds, carbon numbers in these aliphatic amine compounds Residual amino group and / or imino by reacting 2-30 monocarboxylic acid (fatty acid, etc.) or polycarboxylic acid having 2-30 carbon atoms such as oxalic acid, phthalic acid, trimellitic acid, pyromellitic acid, etc. Base Some or amidated or neutralize all, so-called acid-modified compounds, and the like. Preferable examples include N, N-dipolyoxyethylene-N-oleylamine.
[0024]
Further, the content of the fatty acid ester-based ashless friction modifier and / or the aliphatic amine-based ashless friction modifier is not particularly limited, but is 0.05 to 5 based on the total amount of the lubricating oil and / or hydraulic oil. It is preferably 3.0%, more preferably 0.1 to 2.0%, particularly preferably 0.5 to 1.4%. If the content is less than 0.05%, the friction reducing effect tends to be small, and if it exceeds 3.0%, the solubility in hydraulic oil and storage stability are significantly deteriorated, and precipitates are easily generated. It is not preferable.
[0025]
On the other hand, it is preferable that one or both of the lubricating oil and hydraulic oil used in the present invention contain polybutenyl succinimide and / or a derivative thereof.
Examples of the polybutenyl succinimide include the following chemical formulas (1) and (2)
[0026]
[Chemical 1]

[0027]
[Chemical 2]

[0028]
The compound represented by these is mentioned. PIB in these chemical formulas represents a polybutenyl group, and the number average molecular weight obtained by polymerizing a high purity isobutene or a mixture of 1-butene and isobutene with a boron fluoride catalyst or an aluminum chloride catalyst is 900 to 3500, preferably 1000. Obtained from ˜2000 polybutenes. When the number average molecular weight is less than 900, the cleanability effect tends to be poor, and when it exceeds 3500, the low temperature fluidity tends to be poor.
Further, n in the chemical formula is preferably an integer of 1 to 5, more preferably an integer of 2 to 4, from the viewpoint of excellent cleanliness. Further, the polybutene is used to remove a trace amount of fluorine and chlorine remaining due to the catalyst in the production process by an appropriate method such as an adsorption method or sufficient water washing, and is preferably 50 ppm or less, more preferably 10 ppm or less, and particularly preferably 1 ppm. It is also possible to use after removing to the following.
[0029]
Furthermore, the method for producing the polybutenyl succinimide is not particularly limited. For example, the polybutene chlorinated product or polybutene from which chlorine or fluorine is sufficiently removed and maleic anhydride are reacted at 100 to 200 ° C. The polybutenyl succinic acid thus obtained can be obtained by reacting with polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and the like.
[0030]
On the other hand, as a derivative of the polybutenyl succinimide, a boron compound or an oxygen-containing organic compound is allowed to act on the compound represented by the chemical formula (1) or (2), thereby remaining amino group and / or imino. Examples thereof include so-called boron-modified or acid-modified compounds in which part or all of the groups are neutralized or amidated. Among them, boron-containing polybutenyl succinimide, particularly boron-containing bispolybutenyl succinimide is most preferable.
[0031]
Examples of the boron compound include boric acid, borates, and borate esters. Specifically, examples of the boric acid include orthoboric acid, metaboric acid, and tetraboric acid. Moreover, as said borate, ammonium borate, such as ammonium salt etc., specifically, for example, ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium octaborate, etc. are mentioned as a suitable example. As the boric acid ester, an ester of boric acid and preferably an alkyl alcohol having 1 to 6 carbon atoms, more specifically, for example, monomethyl borate, dimethyl borate, trimethyl borate, monoethyl borate, boric acid Preferred examples include diethyl, triethyl borate, monopropyl borate, dipropyl borate, triplypropyl borate, monobutyl borate, dibutyl borate, tributyl borate and the like. In addition, the mass ratio “B / N” of the boron content B and the nitrogen content N in the boron-containing polybutenyl succinimide is usually 0.1 to 3, preferably 0.2 to 1. .
Specific examples of the oxygen-containing organic compound include formic acid, acetic acid, glycolic acid, propionic acid, lactic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecyl. C1-C30 monocarboxylic acid such as acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, oleic acid, nonadecanoic acid, eicosanoic acid, oxalic acid, phthalic acid, Examples thereof include C2-C30 polycarponic acids such as trimellitic acid and pyromellitic acid, and anhydrides or ester compounds thereof, alkylene oxides having 2 to 6 carbon atoms, and hydroxy (poly) oxyalkylene carbonates.
In the hydraulic oil used in the present invention, the content of polybutenyl succinimide and / or its derivative is not particularly limited, but is preferably 0.1 to 15%, more preferably 1.0 to 12%. It is preferable. If it is less than 0.1%, the cleaning effect may be poor, and if it exceeds 15%, it is difficult to obtain a cleaning effect corresponding to the content, and the demulsibility tends to deteriorate.
[0033]
Furthermore, one or both of the lubricating oil and hydraulic oil used in the present invention are represented by the following chemical formula (3):
[0034]
[Chemical 3]

[0035]
It is preferable to contain the zinc dithiophosphate represented by these.
R ⁴ , R ⁵ , R ⁶ and R ⁷ in the chemical formula (3) each independently represent a hydrocarbon group having 1 to 24 carbon atoms. Examples of these hydrocarbon groups include linear or branched alkyl groups having 1 to 24 carbon atoms, linear or branched alkenyl groups having 3 to 24 carbon atoms, and cycloalkyl groups having 5 to 13 carbon atoms. Or a linear or branched alkylcycloalkyl group, an aryl group having 6 to 18 carbon atoms, a linear or branched alkylaryl group, an arylalkyl group having 7 to 19 carbon atoms, or the like. It is desirable. The alkyl group or alkenyl group may be any of primary, secondary, and tertiary.
[0036]
Specific examples of R ⁴ , R ⁵ , R ⁶ and R ⁷ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group, tricosyl group, tetracosyl group, alkyl group, propenyl group, Isopropenyl group, butenyl group, butadienyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, oleyl Octadeseni Group, nonadecenyl group, icocenyl group, heicosenyl group, dococenyl group, tricocenyl group, tetracocenyl group and other alkenyl groups, cyclopentyl group, cyclohexyl group, cycloheptyl group and other cycloalkyl groups, methylcyclopentyl group, dimethylcyclopentyl group, ethyl Cyclopentyl group, propylcyclopentyl group, ethylmethylcyclopentyl group, trimethylcyclopentyl group, diethylcyclopentyl group, ethyldimethylcyclopentyl group, propylmethylcyclopentyl group, propylethylcyclopentyl group, di-propylcyclopentyl group, propylethylmethylcyclopentyl group, methylcyclohexyl Group, dimethylcyclohexyl group, ethylcyclohexyl group, propylcyclohexyl group, ethylmethylcyclohexyl , Trimethylcyclohexyl group, diethylcyclohexyl group, ethyldimethylcyclohexyl group, propylmethylcyclohexyl group, propylethylcyclohexyl group, di-propylcyclohexyl group, propylethylmethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, Ethylcycloheptyl group, propylcycloheptyl group, ethylmethylcycloheptyl group, trimethylcycloheptyl group, diethylcycloheptyl group, ethyldimethylcycloheptyl group, propylmethylcycloheptyl group, propylethylcycloheptyl group, di-propylcycloheptyl group Alkylcycloalkyl groups such as propylethylmethylcycloheptyl group, aryl groups such as phenyl group and naphthyl group, tolyl group, xylyl group, Nyl group, propylphenyl group, ethylmethylphenyl group, trimethylphenyl group, butylphenyl group, propylmethylphenyl group, diethylphenyl group, ethyldimethylphenyl group, tetramethylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group , Alkylaryl groups such as octylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group, dodecylphenyl group, benzyl group, methylbenzyl group, dimethylbenzyl group, phenethyl group, methylphenethyl group, dimethylphenethyl group, etc. An arylalkyl group etc. can be illustrated.
The hydrocarbon groups that R ⁴ , R ⁵ , R ^6, and R ⁷ can include all possible linear structures and branched structures, and also include double bonds of alkenyl groups. The position, the bonding position of the alkyl group to the cycloalkyl group, the bonding position of the alkyl group to the aryl group, and the bonding position of the aryl group to the alkyl group are arbitrary. Further, among the hydrocarbon groups, when the hydrocarbon group is a linear or branched alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a linear or branched group Particularly preferred is a linear alkylaryl group.
[0037]
Preferred examples of the zinc dithiophosphate include, for example, zinc diisopropyldithiophosphate, zinc diisobutyldithiophosphate, zinc di-sec-butyldithiophosphate, zinc di-sec-pentyldithiophosphate, zinc di-n-hexyldithiophosphate. , Zinc di-sec-hexyldithiophosphate, zinc di-octyldithiophosphate, zinc di-2-ethylhexyldithiophosphate, zinc di-n-decyldithiophosphate, zinc di-n-dodecyldithiophosphate, zinc diisotridecyldithiophosphate , And mixtures according to any combination thereof.
[0038]
In addition, the content of the zinc dithiophosphate is not particularly limited, but from the viewpoint of exerting a higher friction reduction effect, it is 0.1% or less in terms of the total amount of the lubricating oil and / or hydraulic oil and in terms of phosphorus element. It is preferable that it is 0.06% or less, and it is particularly preferable that zinc dithiophosphate is not contained. When the zinc dithiophosphate content exceeds 0.1% in terms of phosphorus element, the fatty acid ester-based ashless friction modifier and the aliphatic amine-based ashless friction on the sliding surface between the DLC member and the iron base member There exists a possibility that the outstanding friction reduction effect of a regulator may be inhibited.
[0039]
As a method for producing the zinc dithiophosphate, a conventional method can be arbitrarily adopted, and is not particularly limited. Specifically, for example, hydrocarbons corresponding to R ⁴ , R ⁵ , R ⁶ and R ⁷ are used. It can be synthesized by reacting a group-containing alcohol or phenol with phosphorus pentasulfide to dithiophosphoric acid and neutralizing it with zinc oxide. In addition, it cannot be overemphasized that the structure of the said zinc dithiophosphate changes with raw material alcohol to be used.
In the present invention, two or more kinds of zinc dithiophosphates included in the chemical formula (3) may be mixed and used at an arbitrary ratio.
[0040]
As described above, the hydraulic oil used in the present invention exhibits extremely excellent low friction characteristics when used on a sliding surface with a hard carbon thin film such as DLC. For the purpose of enhancing the performance required as oil, metallic detergents, antioxidants, viscosity index improvers, other ashless friction modifiers, other ashless dispersants, antiwear or extreme pressure agents, rust inhibitors, A nonionic surfactant, a demulsifier, a metal deactivator, an antifoamer, etc. can be mix | blended individually or in combination of multiple types, and required performance can be improved.
[0041]
As said metallic detergent, the arbitrary compounds normally used as metallic detergents, such as lubricating oil, can be used. For example, alkali metal or alkaline earth metal sulfonates, phenates, salicylates, naphthenates, and the like can be used alone or in combination. Here, examples of the alkali metal include sodium (Na) and potassium (K), and examples of the alkaline earth metal include calcium (Ca) and magnesium (Mg). Specific preferred examples include Ca or Mg sulfonates, phenates and salicylates.
In addition, the total base number and addition amount of these metal detergents can be arbitrarily selected according to the required performance of the hydraulic oil. Usually, the total base number is 0 to 500 mgKOH / g, preferably 150 to 400 mgKOH / g by the perchloric acid method, and the amount added is usually 0.1 to 10 based on the total amount of the lubricating oil and / or hydraulic oil. %.
[0042]
Moreover, as said antioxidant, the arbitrary compounds normally used as antioxidant, such as lubricating oil, can be used. For example, phenolic antioxidants such as 4,4′-methylenebis (2,6-di-tert-butylphenol) and octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, phenyl Examples thereof include amine-based antioxidants such as -α-naphthylamine, alkylphenyl-α-naphthylamine, and alkyldiphenylamine, as well as mixtures according to any combination thereof. Moreover, the addition amount of this antioxidant is 0.01 to 5% normally on the basis of the total amount of lubricating oil and / or hydraulic oil.
[0043]
Furthermore, as the above viscosity index improver, specifically, a so-called non-dispersion type viscosity index improver such as a copolymer of one or more monomers selected from various methacrylic acid esters and hydrogenated products thereof, Furthermore, a so-called dispersion type viscosity index improver obtained by copolymerizing various methacrylic acid esters containing a nitrogen compound can be exemplified. Specific examples of other viscosity index improvers include non-dispersed or dispersed ethylene-α-olefin copolymers (eg, α-olefins include propylene, 1-butene, 1-pentene, etc.) and hydrogen thereof. Examples thereof include a compound, polyisobutylene and a hydrogenated product thereof, a styrene-diene hydrogenated copolymer, a styrene-maleic anhydride ester copolymer, and a polyalkylstyrene.
The molecular weight of these viscosity index improvers needs to be selected in consideration of shear stability. Specifically, the number average molecular weight of the viscosity index improver is, for example, 5,000 to 1,000,000, preferably 100,000 to 800,000 for dispersed and non-dispersed polymethacrylates, 800 to 5,000 for polyisobutylene or a hydride thereof, ethylene- In the case of an α-olefin copolymer or a hydride thereof, 800 to 300,000, preferably 10,000 to 200,000 is preferable. Further, such a viscosity index improver can be contained alone or in any combination of plural kinds, but the content is usually preferably 0.1 to 40.0% based on the total amount of hydraulic oil. .
[0044]
Furthermore, other ashless friction modifiers include ashless friction modifiers such as boric acid esters, higher alcohols, aliphatic ethers, metal friction modifiers such as molybdenum dithiophosphate, molybdenum dithiocarbamate, and molybdenum disulfide. Is mentioned.
Other ashless dispersants include polybutenylbenzylamine and polybutenylamine having a polybutenyl group having a number average molecular weight of 900 to 3500, and polybutenyl succinimide having a polybutenyl group having a number average molecular weight of less than 900. And derivatives thereof.
[0045]
Furthermore, as the antiwear agent or extreme pressure agent, disulfide, sulfurized fat and oil, sulfurized olefin, phosphate ester containing 1 to 3 hydrocarbon groups having 2 to 20 carbon atoms, thiophosphate ester, phosphite ester, Examples thereof include thiophosphite esters and amine salts thereof.
Furthermore, examples of the rust preventive include alkylbenzene sulfonate, dinonyl naphthalene sulfonate, alkenyl succinate, polyhydric alcohol ester and the like.
[0046]
Examples of the nonionic surfactant and demulsifier include polyalkylene glycol nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl naphthyl ether, and the like. .
Furthermore, examples of the metal deactivator include imidazoline, pyrimidine derivatives, thiadiazole, benzotriazole, thiadiazole and the like.
Furthermore, examples of the antifoaming agent include silicone, fluorosilicone, and fluoroalkyl ether.
[0047]
When each of the above additives is contained in the hydraulic oil used in the present invention, the content is based on the total amount of the hydraulic oil, and other friction modifiers, other ashless dispersants, antiwear agents, or extreme pressure agents. Further, it can be appropriately selected from the range of 0.01 to 5% for the rust inhibitor and the demulsifier, 0.005 to 1% for the metal deactivator, and 0.0005 to 1% for the antifoaming agent.
[0048]
In the washer of the present invention described above, it is preferable to use a metal part or a ceramic part as a sliding counterpart, and the surface roughness of the sliding surface of this sliding counterpart is Rz (JIS B). The maximum average roughness (0601-2001) is preferably 2 μm or less. Thus, a stable sliding state is easily maintained over a long period of time. In addition, when Rz of the sliding contact surface exceeds 2 μm, the hard carbon thin film is easily peeled off from the substrate by the sliding contact surface, and the friction reducing effect and the friction resistance improving effect by the hard carbon thin film may not be obtained.
Further, examples of the material of the sliding partner material include metal materials such as carbon steel, stainless steel, and cast iron, and ceramic materials such as SiC, TiC, and Al ₂ O ₃ .
[0049]
Next, the washer manufacturing method of the present invention will be described in more detail.
In this manufacturing method, a synthetic resin is molded into a washer shape, and then a diamond-like carbon is coated on the surface by a plasma CDV method to provide a hard carbon thin film to obtain a washer. At this time, the hard carbon thin film does not necessarily have to be coated on the entire surface of the synthetic resin, and may be coated only on a portion to which a high-pressure load is applied.
In addition, the surface of the synthetic resin before coating the hard carbon thin film has an arithmetic average roughness Ra of 5.0 μm or less with an arithmetic average roughness Ra of JIS B 0601-2001 from the viewpoint of suppressing the aggressiveness to the sliding partner material. It is desirable to be.
Furthermore, it is desirable that the thickness of the hard carbon thin film be 0.01 to 1 μm.
[0050]
Next, the automatic transmission according to the present invention will be described in more detail.
The automatic transmission according to the present invention is configured using the above-described washer and lubricating oil and / or hydraulic oil. For this reason, since the amount of wear on the counterpart material side is greatly reduced, the automatic transmission can be reduced in size and weight, and the efficiency can be further improved.
[0051]
FIG. 2 is a cross-sectional view showing the structure of an automatic transmission for an automobile incorporating a washer. An oil-in-water thrust washer 1 and a smaller-diameter oil-in-oil thrust washer 9 are provided in the main part of a fluid torque converter of the automobile. The state which mounted | wore the thrust washer 10 in oil which does not have a processus | protrusion on both surfaces is shown.
The main part of the torque converter transmits rotational power (torque) between the turbine-side boss 11 and the impeller-side hub 12. The in-oil thrust washer 10 is responsible for the thrust force between the converter cover 13 and the turbine hub 14 and is in sliding contact with the in-oil thrust washer 9. The in-oil thrust washer 1 receives and thrusts the thrust force between the impeller side member 17 of the one-way clutch 15 and the hub 18 on the impeller side.
[0052]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited only to these Examples.
[0053]
(Adjusting hydraulic oil)
[1] Hydraulic oil A
Polyalphaolefin (1-octene oligomer) as base oil, 1.0% glycerin monooleate as ester ashless friction modifier, 5.0% polybutenyl succinimide as ashless dispersant, etc. A total of 7.0% of a viscosity index improver, antioxidant, rust inhibitor, anti-emulsifier, nonionic surfactant, metal deactivator, antifoaming agent, etc. are added as additives. It was.
[2] Hydraulic oil B
A hydraulic oil consisting only of polyalphaolefin (1-octene oligomer) as a base oil was prepared as hydraulic oil B.
[0054]
(Example 1)
After drying pellets of polyamide 66 resin (Zytel 70G33HS1L DuPont) compounded with glass fiber 33% in advance, a washer test piece 10 as shown in FIG. 3 was molded using an injection molding machine. Thereafter, the side surface of the washer test piece 10 was polished to have a surface roughness Ra of about 3 μm.
Next, the washer test piece 10 was put in a plasma CVD apparatus, vacuumed, and then the side surface of the washer test piece, which is a film formation surface, was washed with H ₂ plasma, and then a hard carbon thin film was formed with CH ₄ plasma. The film thickness of the hard carbon thin film was 0.7 to 0.8 μm.
A wear test described later was performed using the ring test piece and the hydraulic oil A.
[0055]
(Example 2)
A washer test piece was obtained by repeating the same operation as in Example 1 except that a pellet of polyetheretherketone resin (450GL30 manufactured by Victorex MC Corporation) in which 30% glass fiber was previously compounded was used. Similarly, a wear test described later was performed.
[0056]
(Comparative Example 1)
The same operation as in Example 1 was repeated to obtain a washer test piece. Moreover, the abrasion test mentioned later was done similarly to Example 1 except having used hydraulic oil B.
[0057]
(Comparative Example 2)
The same operation as Example 2 was repeated to obtain a washer test piece. Moreover, the abrasion test mentioned later was done similarly to Example 1 except having used hydraulic oil B.
[0058]
(Comparative Example 3)
A washer test piece was obtained by repeating the same operation as in Example 1 except that the hard carbon thin film was not provided. Moreover, the abrasion test mentioned later was done like Example 1. FIG.
[0059]
(Performance evaluation)
In order to confirm the effect of improving the sliding characteristics of the present invention, a wear test using a washer test piece was performed in oil. A general carbon steel (S55C tempered material HRA = 70) was selected as the mating material for sliding contact. In order to attach to a test apparatus, the shape of the test piece of carbon steel was a disk 38 having a diameter of 60 mm and a thickness of 10 mm, and the surface roughness of the sliding surface was Rz (maximum roughness) = 2 μm.
[0060]
FIG. 4 shows an outline of a vertical pin-on-disk type friction wear tester used for this wear test.
The tester has a ring holder 34 at the top, and this ring holder 34 is a snap ring installed on the inner peripheral surface side of the washer test piece so that radial movement of the washer test piece 10 does not occur during sliding. With the spring force of 35, the outer peripheral surface of the washer test piece is pressed against the holder groove and fixed.
On the other hand, a disk holder 39 coupled to the rotating shaft 40 is provided at the lower part of the test machine. When the disk 38 is fixed to the disk holder 39 with bolts, the disk 38 is rotatable with respect to the washer test piece 10. Next, the washer test piece 10 and the disk 38 are brought into a sliding contact relationship by lowering the ring holder 34, and the washer test piece 10 and the disk 38 are pressed against each other by applying pressure P from the axial direction of the ring holder 34. Will do. At this time, the sliding contact portion between the washer test piece 10 and the disk 38 is immersed in the hydraulic oil 41. Reference numeral 36 denotes a load cell, and reference numeral 37 denotes a torque detector.
[0061]
Table 1 shows the results of a wear test performed using the above tester under the test conditions of pressure contact surface pressure: 3 MPa, friction speed: 10 m / sec, test time: 6 hours.
[0062]
[Table 1]

[0063]
From Table 1, it is clear that the combination of the washer test piece and the working oil according to Examples 1 and 2 which are simulation embodiments of the present invention exhibits excellent low friction characteristics.
[0064]
【The invention's effect】
As described above, according to the present invention, the sliding surface of the washer is covered with a hard carbon thin film, and a specific ashless friction modifier is added to the lubricating oil or hydraulic oil. Further, it is possible to provide a synthetic resin thrust washer excellent in wear resistance and a low friction coefficient and a method for manufacturing the same, and an automatic transmission that contributes to reduction in size, weight, and efficiency.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of the washer of the present invention.
FIG. 2 is a sectional view showing an example of an automatic transmission using the washer of the present invention.
FIG. 3 is a perspective view showing the shape of a washer test piece used in an abrasion test in Examples.
FIG. 4 is a schematic view of a vertical pin-on-disk type friction wear tester used for wear tests in Examples.
[Explanation of symbols]
1 Thrust washer in oil 9 Thrust washer in oil (smaller than 1)
10 Thrust washer in oil (no protrusions on both sides)
11 Turbine-side boss 12 Impeller-side hub 13 Converter cover 14 Turbine hub 15 One-way clutch 16 Turbine side member 17 Impeller side member 18 Impeller-side hub

Claims (10)

A washer comprising a disk-shaped synthetic resin as a base material,
The sliding surface is coated with a hard carbon thin film, and a lubricating oil and / or hydraulic fluid containing a fatty acid ester-based ashless friction modifier and / or an aliphatic amine-based ashless friction modifier is applied to the sliding surface. A washer characterized by interposition. The fatty acid ester-based ashless friction modifier and / or the aliphatic amine-based ashless friction modifier has a hydrocarbon group having 6 to 30 carbon atoms and is 0.05 on the basis of the total amount of lubricating oil and / or hydraulic oil. The washer according to claim 1, which is contained in an amount of ˜3.0%. The washer according to claim 1 or 2, wherein the lubricating oil and / or hydraulic oil contains polybutenyl succinimide and / or a derivative thereof. The washer according to claim 3, comprising 0.1 to 15% of the polybutenyl succinimide and / or derivative thereof based on the total amount of lubricating oil and / or hydraulic oil. The lubricating oil and / or hydraulic oil contains zinc dithiophosphate in an amount of 0.1% or less in terms of the total amount of the lubricating oil and / or hydraulic oil and in terms of phosphorus element. The washer according to any one of the items. The synthetic resin is at least one selected from the group consisting of polyamide resin, polyester resin, polyphenylene sulfide resin, polyethersulfone resin, polyamideimide resin, polyetherimide resin, polyetheretherketone resin, polyimide resin, and phenol resin. The washer according to any one of claims 1 to 5, wherein the washer is a seed resin. The washer according to any one of claims 1 to 6, wherein the hard carbon thin film is diamond-like carbon formed by a plasma CVD method. A metal part or a ceramic part is used as a sliding member, and the surface roughness of the sliding surface of this sliding member is 2 μm or less in terms of Rz (maximum average roughness). The washer according to any one of 7 items. In manufacturing the washer according to any one of claims 1 to 8,
A method for producing a washer, comprising forming a hard carbon thin film by coating a diamond-like carbon on a part or all of a surface by a plasma CDV method after molding a synthetic resin into a washer shape. An automatic transmission comprising the washer according to any one of claims 1 to 8, a lubricating oil, and / or a hydraulic oil.

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