JP4325051B2

JP4325051B2 - Manufacturing method of wheel bearing rolling bearing unit

Info

Publication number: JP4325051B2
Application number: JP35707399A
Authority: JP
Inventors: 裕也宮崎
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 1999-12-16
Filing date: 1999-12-16
Publication date: 2009-09-02
Anticipated expiration: 2019-12-16
Also published as: JP2001171304A

Description

【０００１】
【発明の属する技術分野】
この発明は、自動車の車輪を懸架装置に対して回転自在に支持する為の車輪支持用転がり軸受ユニットの製造方法の改良に関する。
【０００２】
【従来の技術】
自動車の車輪は、車輪支持用転がり軸受ユニットにより懸架装置に支持する。図２は、従来から広く実施されている車輪支持用転がり軸受ユニットの第１例を示している。この車輪支持用転がり軸受ユニット１は、ハブ２と、内輪３と、外輪４と、複数個の転動体５、５とを備える。このうちのハブ２の外周面の外端部（外とは、自動車への組み付け状態で幅方向外寄りとなる側を言い、図１、６を除く各図の左側となる。反対に幅方向中央寄りとなる側を内と言い、図１、６を除く各図の右側となる。）には、車輪を支持する為の第一のフランジ６を形成している。又、このハブ２の中間部外周面には第一の内輪軌道７を、同じく内端部には外径寸法が小さくなった段部８を、それぞれ形成している。
【０００３】
上記段部８には、外周面に第二の内輪軌道９を形成した、上記内輪３を外嵌している。又、上記ハブ２の内端部には雄ねじ部１０を形成し、この雄ねじ部１０の先端部（図２の右端部）を、上記内輪３の内端面よりも内方に突出させている。そして、この雄ねじ部１０に螺合したナット１１と上記段部８の段差面１２との間で上記内輪３を挟持する事により、この内輪３を上記ハブ２の所定位置に結合固定している。尚、上記雄ねじ部１０の先端部外周面には、係止凹部１３を形成している。そして、上記ナット１１を所定のトルクで緊締した後、このナット１１の一部で上記係止凹部１３に整合する部分を直径方向内方にかしめ付ける事により、このナット１１の緩み止めを図っている。
【０００４】
又、上記外輪４の内周面には、上記第一の内輪軌道７と対向する第一の外輪軌道１４、及び、上記第二の内輪軌道９に対向する第二の外輪軌道１５を形成している。そして、これら第一、第二の内輪軌道７、９と第一、第二の外輪軌道１４、１５との間に上記転動体５、５を、それぞれ複数個ずつ設けている。尚、図示の例では、転動体５、５として玉を使用しているが、重量の嵩む自動車用の転がり軸受ユニットの場合には、これら転動体としてテーパころを使用する場合もある。
【０００５】
上述の様な車輪支持用転がり軸受ユニット１を自動車に組み付けるには、上記外輪４の外周面に形成した第二のフランジ１６により、この外輪４を懸架装置に固定し、上記第一のフランジ６に車輪を固定する。この結果、この車輪を懸架装置に対し回転自在に支持する事ができる。
【０００６】
又、特開平１１−１２９７０３号公報には、図３〜５の様な車輪支持用転がり軸受ユニット１ａが記載されている。この従来構造の第２例の車輪支持用転がり軸受ユニット１ａは、ハブ２ａと、内輪３と、外輪４と、複数個の転動体５、５とを備える。このうちのハブ２ａの外周面の外端寄り部分には、車輪を支持する為の第一のフランジ６を形成している。又、このハブ２ａの中間部外周面には第一の内輪軌道７を、同じく内端部には外径寸法が小さくなった段部８を、それぞれ形成している。
【０００７】
又、上記ハブ２ａの内端部には、上記内輪３を固定する為のかしめ部１７を構成する為の円筒部１８を形成している。この円筒部１８の肉厚は、図５に示した、この円筒部１８を直径方向外方にかしめ広げる以前の状態で、先端縁（図５の右端縁）に向かう程小さくなっている。この為上記ハブ２ａの内端面に、奥部に向かう程次第に内径が小さくなるテーパ孔１９を形成している。
【０００８】
上記ハブ２ａの内端部に上記内輪３を固定すべく、上述の様な円筒部１８の先端部をかしめ広げるには、上記ハブ２ａが軸方向にずれ動かない様に固定した状態で、図４に示す様に、押型２０を上記円筒部１８の先端部に強く押し付ける。この押型２０の先端面（図４の左端面）中央部には、上記円筒部１８の内側に押し込み自在な円錐台状の凸部２１を形成し、この凸部２１の周囲に断面円弧状の凹部２２を、この凸部２１の全周を囲む状態で形成している。尚、この凹部２２の断面形状は、この凹部２２により上記円筒部１８の先端部を塑性変形させる事により得られるかしめ部１７の断面形状が、基端部から先端部に向かう程厚さ寸法が漸次小さくなる様に、特にこの厚さ寸法が先端部で急激に小さくなる様に、外径側に向かう程曲率半径が小さくなる複合曲面としている。
【０００９】
上述の様な形状並びに寸法の凸部２１と凹部２２とを有する押型２０を上記円筒部１８の先端部に押し付ければ、この円筒部１８の先端部を直径方向外方にかしめ広げて、上記かしめ部１７を形成する事ができる。そして、このかしめ部１７とハブ２ａの内端部に形成した段部８の段差面１２との間で上記内輪３を挟持して、この内輪３を上記ハブ２ａに固定できる。
【００１０】
尚、上記円筒部１８を塑性変形させて（かしめ広げて）上記かしめ部１７を形成する作業を行なうのに好ましくは、図６に示す様な揺動プレス装置２３を使用する。この揺動プレス装置２３は、押型２０と、抑え治具２４と、ホルダ２５とを備える。このホルダ２５は、この押型２０から円筒部１８に加えられる押圧力に基づく荷重を支承する受具として機能するもので、底板部２６の上面中央部に凹部２７を設けている。上記円筒部１８のかしめ広げ作業を行なう際には、ハブ２ａの外端面（図６の下端面）中央部に形成した円筒状のガイド部２８を上記凹部２７に進入させ、上記ハブ２ａの外端部外周面に形成した第一のフランジ６の外側面を、上記底板部２６の上面で上記凹部２７の周囲部分に載置する。
【００１１】
上記円筒部１８をかしめ広げて上記かしめ部１７を形成する際には、上記ホルダ２５を介して上記ハブ２ａを上方に押圧しつつ、上記押型２０を揺動変位させる。即ち、この押型２０の中心軸と上記ハブ２ａの中心軸とを角度θだけ傾斜させた状態で、この押型２０を、このハブ２ａの中心軸を中心として、転がる様に揺動変位させる。この様な揺動プレスにより上記かしめ部１７を形成する際には、上記押型２０の円周方向の一部が上記円筒部１８を押圧する事になり、上記かしめ部１７への加工作業は部分的に且つ円周方向に連続して進行する事になる。この為、一般的な鍛造加工により上記かしめ部１７を形成する場合に比べて、加工時に上記円筒部１８に加える荷重を小さくできる。尚、上記抑え治具２４は、それぞれが半円輪状に構成された１対の素子を組み合わせて円輪状としたもので、上記押型２０によるかしめ部１７の加工時に上記ハブ２ａ及び内輪３が径方向に振れる事を防止する。
【００１２】
【発明が解決しようとする課題】
上述した様な従来の車輪支持用転がり軸受ユニットとその製造方法の場合には、円筒部１８をかしめ広げる際に、ハブ２ａの外端部外周面に形成した第一のフランジ６に大きなスラスト荷重が加わる。即ち、揺動かしめ作業時にホルダ２５に加えられる押圧力は、このホルダ２５の底板部２６の上面から上記第一のフランジ６に加えられ、更に上記ハブ２ａの本体部分に伝わる。そして、このハブ２ａの内端部（図６の上端部）に形成した円筒部１８を、押型２０に押し付ける。従って、上記ハブ２ａには、これら円筒部１８と押型２０との押し付け合いに伴う反力がスラスト荷重として加わる。
【００１３】
このスラスト荷重が上記フランジ６の全周に亙って均等に、しかも上記ハブ２ａの軸方向に対し平行に加われば特に問題ないが、実際には上記スラスト荷重は、不均一にしかも上記ハブ２ａの軸方向に対し押型２０の傾斜角度θ分傾斜した状態で加わる。この結果、このハブ２ａの内端部に揺動かしめによりかしめ部１７を形成した後の状態では、車輪及びディスクロータの取付面となる、上記第一のフランジ６の外側面が、僅かとは言え、上記ハブ２ａの中心軸に直交する仮想平面に対し傾斜する可能性がある。
【００１４】
この様に上記第一のフランジ６の外側面が傾斜し、この外側面に取り付けたディスクロータの両側面が上記ハブ２ａの中心軸に直交する仮想平面に対し傾斜すると、高速走行状態からの制動時に、ジャダーと呼ばれる振動が発生する。この様な振動は、運転者を含む乗員に不快感を与える為、好ましくない。この様なジャダーの発生を防止する為に従来から、ハブの外周面に設ける内輪軌道と第一のフランジの外側面との位置関係を正確に規制しつつ、これらハブの外周面及び内輪軌道の仕上を行なう技術が提案されている。一方、上記円筒部１８をかしめ広げてかしめ部１７を形成する揺動かしめ作業は、上記ハブの外周面及び内輪軌道の仕上を行なった後に行なう。従って、この揺動かしめ作業時に上記第一のフランジ６が僅かと言えども変形する事を防止しない限り、上記ジャダーの発生を有効に防止できない。
本発明は、この様な事情に鑑みて、上記揺動かしめ作業時に上記第一のフランジ６が変形する事を防止した車輪支持用転がり軸受ユニットの製造方法の実現を図るものである。
【００１５】
【課題を解決するための手段】
本発明の製造方法の対象となる車輪支持用転がり軸受ユニットは、前述した従来から知られている車輪支持用転がり軸受ユニットと同様に、一端部外周面に第一のフランジを、中間部外周面に第一の内輪軌道を、一端面に円筒状のガイド部を、それぞれ形成したハブと、このハブの他端部に形成された、上記第一の内輪軌道を形成した部分よりも外径寸法が小さくなった段部と、外周面に第二の内輪軌道を形成して上記段部に外嵌した内輪と、内周面に上記第一の内輪軌道に対向する第一の外輪軌道及び上記第二の内輪軌道に対向する第二の外輪軌道を、外周面に第二のフランジを、それぞれ形成した外輪と、上記第一、第二の内輪軌道と上記第一、第二の外輪軌道との間に、それぞれ複数個ずつ設けられた転動体とを備える。そして、上記ハブの他端部で少なくとも上記段部に外嵌した内輪よりも突出した部分に形成した円筒部を、揺動変位する押型に押し付ける揺動かしめにより直径方向外方にかしめ広げる事でかしめ部を形成し、このかしめ部により、上記段部に外嵌した内輪をこの段部の段差面に向け抑え付けて、この段部に外嵌した上記内輪を上記ハブに結合固定している。
【００１６】
特に、本発明の車輪支持用転がり軸受ユニットの製造方法では、上記揺動かしめを行なう際に、上記ガイド部を、上記ハブの一端側に配置され、上記押型から上記円筒部に加えられる押圧力に基づく荷重を支承するホルダに設けたガイド筒部に内嵌すると共に、このホルダの一部でこのガイド筒部の内径側に設置した受具の先端面を、上記ハブの一端面で上記ガイド部に囲まれた部分に突き当てて、上記押型に上記円筒部を押し付ける事に伴って上記ハブに加わる荷重を、上記第一のフランジよりも内径側部分で支承する事により、この第一のフランジにこの荷重が加わらない状態で、上記揺動かしめを行なう。
【００１７】
【作用】
上述の様に構成する本発明の車輪支持用転がり軸受ユニットの製造方法によれば、かしめ部を形成する際に、第一のフランジに荷重が加わらない。従って、この第一のフランジが歪む事がなく、この第一のフランジに固定したディスクロータの両側面と、ハブの中心軸に対し直交する仮想平面とのずれを僅少に抑える事ができる。この結果、制動時に於けるジャダーの発生を防止若しくは低減できる。
【００１８】
【発明の実施の形態】
図１は、本発明の実施の形態の１例を示している。尚、本発明の特徴は、ハブ２ｂの内端部外周面に形成した段部８に外嵌固定した内輪３を抑え付ける、かしめ部１７の加工方法の改良に関する。車輪支持用転がり軸受ユニット全体の構造及び作用は、前述の図３に示した従来構造の第２例と同様であり、揺動プレス装置２３ａの基本的な構成及び作用は、前述の図６に示した従来方法と同様であるから、同等部分に関する説明は、省略若しくは簡略にし、以下、本発明の特徴部分を中心に説明する。
【００１９】
上記揺動プレス装置２３ａを構成するホルダ２５ａの底板部２６ａの上面中央部には、円形の支持凸部２９を設けている。この支持凸部２９の上面周縁部には円筒状のガイド筒部３０を形成しており、上面中央部でこのガイド筒部３０に囲まれた部分には、受具３１を載置している。そして、この受具３１の先端面（上端面）を、上記ハブ２ｂの外端面中央部に形成した凹部３２の奥端面に突き当てている。尚、このハブ２ｂの外端面には、車輪を構成するホイールの中心部に設けた円孔を外嵌する為の円筒状のガイド部２８ａを形成しており、上記凹部３２はこのガイド部２８ａの内径側に設けている。
【００２０】
上記ホルダ２５ａ側のガイド筒部３０の内径は、上記ハブ２ｂ側のガイド部２８ａの外径と同じか、この外径よりも僅かに大きくしている。又、上記ホルダ２５ａの上面で上記ガイド筒部３０の外径側に設けた周壁部３３の内径は、上記ハブ２ｂの外端部外周面に形成した第一のフランジ６の外径と同じか、この外径よりも僅かに大きくしている。従って、上記ハブ２ｂの内端部にかしめ部１７を形成すべく、このハブ２ｂを上記ホルダ２５ａにセットした状態では、上記第一のフランジ６の外周縁は上記周壁部３３の内周面に、上記ガイド部２８ａの外周面は上記ガイド筒部３０の内周面に、それぞれ当接若しくは近接対向する。そして、この状態で、上述の様に、上記ホルダ２５ａ側に載置した受具３１の先端面が、上記ハブ２ｂの外端面中央部に形成した凹部３２の奥端面に突き当たる。
【００２１】
この様に、上記ハブ２ｂを上記ホルダ２５ａ内にセットし、このホルダ２５ａの開口部に抑え治具２４ａを固定して、内輪３及びこの内輪３を外嵌した上記ハブ２ｂが径方向に振れるのを抑えた状態で、上記ホルダ２５ａを上方に押圧しつつ、押型２０を揺動変位させる（角度θで歳差に類似した揺動運動をさせる）。この押型２０の中心軸αは、上記ハブ２ｂの中心軸βに対し角度θだけ傾斜している。従って、上記押型２０は、その円周方向の一部が上記ハブ２ｂの内端部（図１の上端部）に形成した円筒部１８の円周方向の一部に当接すると共に、この当接部を円周方向に亙り連続的に移動させつつ、上記円筒部１８を直径方向外方にかしめ広げて、図１に示す様なかしめ部１７を形成する。
【００２２】
この様に円筒部１８をかしめ広げてかしめ部１７とする際に、上記押型２０と上記円筒部１８（かしめ部１７）との押し付け合いに基づいて上記ハブ２ｂに加わるスラスト荷重は、上記受具３１を介して上記ホルダ２５ａに支承される。上記ハブ２ｂの外端部外周面に形成した第一のフランジ６は前記周壁部３３に、軸方向の変位自在に嵌合しているので、この第一のフランジ６に大きなスラスト荷重が加わる事はない。従って、上記ハブ２ｂの内端部に揺動かしめによりかしめ部１７を形成した後の状態でも、車輪及びディスクロータの取付面となる、上記第一のフランジ６の外側面が、上記ハブ２ａの中心軸に直交する仮想平面に対し傾斜する事はない。
【００２３】
この為、上記第一のフランジ６の外側面とディスクロータとの取付精度を確保さえすれば、このディスクロータの両側面が上記ハブ２ｂの中心軸に直交する仮想平面に対し傾斜する事はなくなる。この結果、高速走行状態からの制動時に於けるジャダーの発生を、防止若しくは低減できる。言い換えれば、従来の場合には、上記ディスクロータの取付面となる、上記第一のフランジ６の外側面の精度を完全に確保する事が難しく、この第一のフランジ６の外側面とディスクロータとの取付精度を確保しても、上記ジャダーの発生を抑える事が難しかった。これに対して、本発明によれば、上記第一のフランジ６の外側面の精度を確保できるので、上述の様に、ジャダーの発生を、防止若しくは低減できる様になる。
【００２４】
【発明の効果】
本発明の車輪支持用転がり軸受ユニットの製造方法は、以上に述べた通り、ディスクロータの取付面となる第一のフランジの精度が悪化する事がないので、制動時にジャダーが発生するのを防止できる等、性能の良好な車輪支持用転がり軸受ユニットを安定して得る事ができる。
【図面の簡単な説明】
【図１】本発明の実施の形態の１例を示す部分断面図。
【図２】従来構造の第１例を示す半部断面図。
【図３】同第２例を示す半部断面図。
【図４】第２例の構造の製造時にハブに内輪を固定する為、このハブの内端部をかしめ広げる状態を示す部分拡大断面図。
【図５】同じくハブの内端部をかしめ広げる以前の状態で示す部分拡大断面図。
【図６】揺動プレス装置の要部縦断面図。
【符号の説明】
１、１ａ車輪支持用転がり軸受ユニット
２、２ａ、２ｂハブ
３内輪
４外輪
５転動体
６第一のフランジ
７第一の内輪軌道
８段部
９第二の内輪軌道
１０雄ねじ部
１１ナット
１２段差面
１３係止凹部
１４第一の外輪軌道
１５第二の外輪軌道
１６第二のフランジ
１７かしめ部
１８円筒部
１９テーパ孔
２０押型
２１凸部
２２凹部
２３、２３ａ揺動プレス装置
２４、２４ａ抑え治具
２５、２５ａホルダ
２６、２６ａ座板部
２７凹部
２８、２８ａガイド部
２９支持凸部
３０ガイド部
３１受具
３２凹部
３３周壁部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a manufacturing method of a wheel bearing rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device.
[0002]
[Prior art]
The wheels of the automobile are supported on the suspension device by a rolling bearing unit for supporting the wheels. FIG. 2 shows a first example of a wheel support rolling bearing unit that has been widely used in the past. The wheel support rolling bearing unit 1 includes a hub 2, an inner ring 3, an outer ring 4, and a plurality of rolling elements 5 and 5. Out of these, the outer end of the outer peripheral surface of the hub 2 (outside means the side that is outside in the width direction when assembled to the automobile, and is the left side of each figure except for FIGS. 1 and 6. The first flange 6 for supporting the wheel is formed on the side closer to the center is called the inner side, and is the right side of each drawing except FIGS. A first inner ring raceway 7 is formed on the outer peripheral surface of the intermediate portion of the hub 2, and a step portion 8 having a smaller outer diameter is formed on the inner end portion.
[0003]
The inner ring 3 having a second inner ring raceway 9 formed on the outer peripheral surface is externally fitted to the stepped portion 8. Further, a male screw portion 10 is formed at the inner end portion of the hub 2, and a tip end portion (right end portion in FIG. 2) of the male screw portion 10 protrudes inward from the inner end surface of the inner ring 3. The inner ring 3 is clamped and fixed to a predetermined position of the hub 2 by sandwiching the inner ring 3 between a nut 11 screwed into the male threaded portion 10 and a stepped surface 12 of the stepped portion 8. . A locking recess 13 is formed on the outer peripheral surface of the distal end portion of the male screw portion 10. Then, after tightening the nut 11 with a predetermined torque, a portion of the nut 11 that is aligned with the locking recess 13 is caulked inward in the diametrical direction, thereby preventing the nut 11 from loosening. Yes.
[0004]
A first outer ring raceway 14 that faces the first inner ring raceway 7 and a second outer ring raceway 15 that faces the second inner ring raceway 9 are formed on the inner peripheral surface of the outer ring 4. ing. A plurality of rolling elements 5 and 5 are provided between the first and second inner ring raceways 7 and 9 and the first and second outer ring raceways 14 and 15, respectively. In the illustrated example, balls are used as the rolling elements 5 and 5. However, in the case of a rolling bearing unit for automobiles that is heavy in weight, tapered rollers may be used as these rolling elements.
[0005]
In order to assemble the wheel support rolling bearing unit 1 as described above to the automobile, the outer ring 4 is fixed to the suspension device by the second flange 16 formed on the outer peripheral surface of the outer ring 4, and the first flange 6 Secure the wheels to the As a result, this wheel can be rotatably supported with respect to the suspension device.
[0006]
JP-A-11-129703 discloses a wheel bearing rolling bearing unit 1a as shown in FIGS. The wheel support rolling bearing unit 1a of the second example of the conventional structure includes a hub 2a, an inner ring 3, an outer ring 4, and a plurality of rolling elements 5, 5. Of these, a first flange 6 for supporting the wheel is formed in a portion near the outer end of the outer peripheral surface of the hub 2a. A first inner ring raceway 7 is formed on the outer peripheral surface of the intermediate portion of the hub 2a, and a step portion 8 having a smaller outer diameter is formed on the inner end portion.
[0007]
A cylindrical portion 18 for forming a caulking portion 17 for fixing the inner ring 3 is formed at the inner end portion of the hub 2a. The thickness of the cylindrical portion 18 becomes smaller toward the tip edge (the right edge in FIG. 5) in the state before the cylindrical portion 18 is caulked outward in the diametrical direction as shown in FIG. For this reason, a tapered hole 19 is formed in the inner end surface of the hub 2a, the inner diameter of which gradually decreases toward the inner part.
[0008]
In order to squeeze the tip of the cylindrical portion 18 as described above in order to fix the inner ring 3 to the inner end of the hub 2a, the hub 2a is fixed so that it does not move in the axial direction. As shown in FIG. 4, the pressing die 20 is strongly pressed against the tip portion of the cylindrical portion 18. A frustoconical convex portion 21 that can be pushed into the inside of the cylindrical portion 18 is formed at the central portion of the tip surface (left end surface in FIG. 4) of the pressing die 20, and a circular arc section is formed around the convex portion 21. The concave portion 22 is formed so as to surround the entire circumference of the convex portion 21. The cross-sectional shape of the concave portion 22 is such that the cross-sectional shape of the caulking portion 17 obtained by plastic deformation of the distal end portion of the cylindrical portion 18 by the concave portion 22 has a thickness dimension as it goes from the proximal end portion toward the distal end portion. The composite curved surface has a curvature radius that becomes smaller toward the outer diameter side, so that the thickness dimension is abruptly reduced especially at the tip portion so as to gradually become smaller.
[0009]
If the pressing die 20 having the convex portion 21 and the concave portion 22 having the shape and dimensions as described above is pressed against the tip portion of the cylindrical portion 18, the tip portion of the cylindrical portion 18 is caulked outward in the diametrical direction, The caulking portion 17 can be formed. The inner ring 3 can be clamped between the caulking portion 17 and the stepped surface 12 of the stepped portion 8 formed at the inner end of the hub 2a, so that the inner ring 3 can be fixed to the hub 2a.
[0010]
Preferably, a swing press device 23 as shown in FIG. 6 is used to perform the operation of forming the caulking portion 17 by plastically deforming (caulking and expanding) the cylindrical portion 18. The swing press device 23 includes a pressing die 20, a holding jig 24, and a holder 25. The holder 25 functions as a support for supporting a load based on the pressing force applied from the pressing die 20 to the cylindrical portion 18, and has a concave portion 27 at the center of the upper surface of the bottom plate portion 26. When the caulking and expanding operation of the cylindrical portion 18 is performed, a cylindrical guide portion 28 formed at the center of the outer end surface (the lower end surface in FIG. 6) of the hub 2a is caused to enter the concave portion 27 so that the outer side of the hub 2a The outer surface of the first flange 6 formed on the outer peripheral surface of the end portion is placed on the peripheral portion of the concave portion 27 on the upper surface of the bottom plate portion 26.
[0011]
When the caulking portion 17 is formed by caulking the cylindrical portion 18, the pressing die 20 is oscillated and displaced while pressing the hub 2 a upward via the holder 25. That is, in a state where the central axis of the pressing die 20 and the central axis of the hub 2a are inclined by an angle θ, the pressing die 20 is oscillated and displaced so as to roll around the central axis of the hub 2a. When the caulking portion 17 is formed by such a rocking press, a part of the pressing die 20 in the circumferential direction presses the cylindrical portion 18, and the machining operation to the caulking portion 17 is a partial process. And continuously in the circumferential direction. For this reason, compared with the case where the said caulking part 17 is formed by a general forging process, the load added to the said cylindrical part 18 at the time of a process can be made small. The holding jig 24 is formed into a ring shape by combining a pair of elements each formed in a semi-annular shape, and the hub 2a and the inner ring 3 have a diameter when the caulking portion 17 is processed by the pressing die 20. Prevents swinging in the direction.
[0012]
[Problems to be solved by the invention]
In the case of the conventional rolling bearing unit for supporting a wheel and the manufacturing method thereof as described above, when the cylindrical portion 18 is caulked and spread, a large thrust load is applied to the first flange 6 formed on the outer peripheral surface of the outer end portion of the hub 2a. Will be added. That is, the pressing force applied to the holder 25 during the rocking caulking operation is applied to the first flange 6 from the upper surface of the bottom plate portion 26 of the holder 25 and further transmitted to the main body portion of the hub 2a. Then, the cylindrical portion 18 formed on the inner end portion (upper end portion in FIG. 6) of the hub 2a is pressed against the pressing die 20. Accordingly, a reaction force accompanying the pressing of the cylindrical portion 18 and the pressing die 20 is applied to the hub 2a as a thrust load.
[0013]
If this thrust load is applied evenly over the entire circumference of the flange 6 and in parallel with the axial direction of the hub 2a, there is no particular problem. However, in reality, the thrust load is non-uniformly and the hub 2a. Is applied in a state where it is inclined by the inclination angle θ of the pressing die 20 with respect to the axial direction. As a result, in a state after the caulking portion 17 is formed by swing caulking on the inner end portion of the hub 2a, the outer surface of the first flange 6 that is the mounting surface of the wheel and the disc rotor is slightly different. In other words, there is a possibility of tilting with respect to a virtual plane orthogonal to the central axis of the hub 2a.
[0014]
In this way, when the outer surface of the first flange 6 is inclined and both side surfaces of the disk rotor attached to the outer surface are inclined with respect to a virtual plane perpendicular to the central axis of the hub 2a, braking from a high-speed running state is performed. Sometimes a vibration called judder occurs. Such vibration is not preferable because it causes discomfort to passengers including the driver. In order to prevent the occurrence of such judder, conventionally, the positional relationship between the inner ring raceway provided on the outer peripheral surface of the hub and the outer side surface of the first flange is accurately regulated, while the outer peripheral surface of these hubs and the inner ring raceway are controlled. Techniques for finishing have been proposed. On the other hand, the rocking caulking operation for caulking and expanding the cylindrical portion 18 to form the caulking portion 17 is performed after finishing the outer peripheral surface of the hub and the inner ring raceway. Therefore, the generation of the judder cannot be effectively prevented unless the first flange 6 is slightly deformed during the swaging caulking operation.
In view of such circumstances, the present invention aims to realize a method of manufacturing a wheel bearing rolling bearing unit that prevents the first flange 6 from being deformed during the swaging operation.
[0015]
[Means for Solving the Problems]
The wheel-supporting rolling bearing unit that is the object of the manufacturing method of the present invention is similar to the conventionally known wheel-supporting rolling bearing unit described above, and includes a first flange on one end outer peripheral surface and an intermediate outer peripheral surface. The outer diameter of the first inner ring raceway, the hub formed with the cylindrical guide portion on one end surface, and the portion formed on the other end of the hub, the portion forming the first inner ring raceway. , The inner ring formed on the outer peripheral surface and externally fitted to the step part, the first outer ring raceway facing the first inner ring raceway and the inner ring A second outer ring track facing the second inner ring track, an outer ring formed with a second flange on the outer peripheral surface, the first and second inner ring tracks, the first and second outer ring tracks, Are provided with a plurality of rolling elements. The cylindrical portion formed at least at the other end of the hub and protruding from the inner ring fitted on the stepped portion is caulked and spread outward in the diametrical direction by oscillating caulking that is pressed against the oscillating displacement pressing die. forming a caulking portion by the caulking portion, an inner ring fitted onto the step portion put suppressed towards the stepped surface of the stepped portion, a fitted the inner ring is fixedly connected to said hub on the step portion .
[0016]
In particular, in the method for manufacturing a wheel-supporting rolling bearing unit according to the present invention, when performing the swaging caulking, the guide portion is disposed on one end side of the hub, and the pressing force applied from the pressing die to the cylindrical portion. The guide tube portion provided in the holder for supporting the load based on the guide tube portion is fitted inside, and the tip end surface of the holder installed on the inner diameter side of the guide tube portion at a part of the holder is connected to the guide at the one end surface of the hub. The first load is applied to the hub by pressing the cylindrical portion against the pressing die and supporting the load applied to the hub on the inner diameter side of the first flange . The rocking caulking is performed in a state where this load is not applied to the flange.
[0017]
[Action]
According to the manufacturing method of the wheel bearing rolling bearing unit of the present invention configured as described above, no load is applied to the first flange when the caulking portion is formed. Therefore, the first flange is not distorted, and the deviation between the both side surfaces of the disk rotor fixed to the first flange and the virtual plane orthogonal to the central axis of the hub can be suppressed to a small extent. As a result, the occurrence of judder during braking can be prevented or reduced.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of an embodiment of the present invention. The feature of the present invention relates to an improvement in the method of processing the caulking portion 17 that suppresses the inner ring 3 that is externally fitted and fixed to the step portion 8 formed on the outer peripheral surface of the inner end portion of the hub 2b. The overall structure and operation of the wheel-supporting rolling bearing unit are the same as those of the second example of the conventional structure shown in FIG. 3, and the basic configuration and operation of the swing press device 23a are shown in FIG. Since it is the same as the conventional method shown, the explanation about the equivalent part is omitted or simplified, and hereinafter, the characteristic part of the present invention will be mainly described.
[0019]
A circular support convex portion 29 is provided at the center of the upper surface of the bottom plate portion 26a of the holder 25a constituting the swing press device 23a. A cylindrical guide tube portion 30 is formed on the peripheral edge of the upper surface of the support convex portion 29, and a receiving tool 31 is placed on the portion surrounded by the guide tube portion 30 at the center of the upper surface. . And the front end surface (upper end surface) of this receiving tool 31 is abutted on the back end surface of the recessed part 32 formed in the center part of the outer end surface of the said hub 2b. A cylindrical guide portion 28a is formed on the outer end surface of the hub 2b so as to fit a circular hole provided at the center of the wheel constituting the wheel. The concave portion 32 is formed on the guide portion 28a. Is provided on the inner diameter side.
[0020]
The inner diameter of the guide cylinder portion 30 on the holder 25a side is the same as or slightly larger than the outer diameter of the guide portion 28a on the hub 2b side. Whether the inner diameter of the peripheral wall 33 provided on the outer diameter side of the guide cylinder 30 on the upper surface of the holder 25a is the same as the outer diameter of the first flange 6 formed on the outer peripheral surface of the outer end of the hub 2b. The outer diameter is slightly larger. Therefore, when the hub 2b is set in the holder 25a so as to form the caulking portion 17 at the inner end portion of the hub 2b, the outer peripheral edge of the first flange 6 is on the inner peripheral surface of the peripheral wall portion 33. The outer peripheral surface of the guide portion 28a is in contact with or in close proximity to the inner peripheral surface of the guide tube portion 30, respectively. In this state, as described above, the distal end surface of the receiving member 31 placed on the holder 25a side abuts on the rear end surface of the recess 32 formed at the center of the outer end surface of the hub 2b.
[0021]
In this manner, the hub 2b is set in the holder 25a, the holding jig 24a is fixed to the opening of the holder 25a, and the inner ring 3 and the hub 2b externally fitted to the inner ring 3 swing in the radial direction. In a state where the above is suppressed, the pressing die 20 is oscillated and displaced while pressing the holder 25a upward (oscillating motion similar to precession is performed at an angle θ). The center axis α of the die 20 is inclined by an angle θ with respect to the center axis β of the hub 2b. Therefore, a part of the die 20 in the circumferential direction abuts on a part in the circumferential direction of the cylindrical portion 18 formed on the inner end portion (the upper end portion in FIG. 1) of the hub 2b. The cylindrical part 18 is caulked and spread outward in the diameter direction while continuously moving the part in the circumferential direction to form a caulking part 17 as shown in FIG.
[0022]
Thus, when the cylindrical portion 18 is caulked and spread into the caulking portion 17, the thrust load applied to the hub 2b based on the pressing force between the pressing die 20 and the cylindrical portion 18 (caulking portion 17) is 31 is supported by the holder 25a. Since the first flange 6 formed on the outer peripheral surface of the outer end portion of the hub 2b is fitted to the peripheral wall portion 33 so as to be axially displaceable, a large thrust load is applied to the first flange 6. There is no. Therefore, even after the caulking portion 17 is formed by swing caulking at the inner end portion of the hub 2b, the outer surface of the first flange 6 that serves as a mounting surface of the wheel and the disc rotor is the surface of the hub 2a. There is no inclination with respect to a virtual plane orthogonal to the central axis.
[0023]
Therefore, as long as the mounting accuracy between the outer surface of the first flange 6 and the disk rotor is ensured, both side surfaces of the disk rotor will not be inclined with respect to a virtual plane perpendicular to the central axis of the hub 2b. . As a result, it is possible to prevent or reduce the occurrence of judder during braking from a high-speed traveling state. In other words, in the conventional case, it is difficult to completely ensure the accuracy of the outer surface of the first flange 6 which is the mounting surface of the disk rotor. The outer surface of the first flange 6 and the disk rotor Even if the mounting accuracy is secured, it is difficult to suppress the occurrence of the judder. On the other hand, according to the present invention, since the accuracy of the outer surface of the first flange 6 can be ensured, the occurrence of judder can be prevented or reduced as described above.
[0024]
【The invention's effect】
As described above, the manufacturing method of the wheel bearing rolling bearing unit according to the present invention prevents the occurrence of judder during braking because the accuracy of the first flange serving as the mounting surface of the disk rotor does not deteriorate. It is possible to stably obtain a wheel bearing rolling bearing unit with good performance.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing an example of an embodiment of the present invention.
FIG. 2 is a half sectional view showing a first example of a conventional structure.
FIG. 3 is a half sectional view showing the second example.
FIG. 4 is a partially enlarged cross-sectional view showing a state in which the inner end of the hub is caulked and spread in order to fix the inner ring to the hub when the structure of the second example is manufactured.
FIG. 5 is a partially enlarged sectional view showing a state before the inner end of the hub is caulked and spread.
FIG. 6 is a longitudinal sectional view of a main part of the swing press device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 1a Rolling bearing unit for wheel support 2, 2a, 2b Hub 3 Inner ring 4 Outer ring 5 Rolling element 6 First flange 7 First inner ring raceway 8 Step portion 9 Second inner ring raceway 10 Male thread portion 11 Nut 12 Stepped surface DESCRIPTION OF SYMBOLS 13 Locking recessed part 14 1st outer ring track 15 2nd outer ring track 16 Second flange 17 Caulking part 18 Cylindrical part 19 Tapered hole 20 Stamping die 21 Convex part 22 Recessed part 23, 23a Oscillating press device 24, 24a Holding jig 25, 25a Holder 26, 26a Seat plate part 27 Concave part 28, 28a Guide part 29 Supporting convex part 30 Guide part 31 Receiving tool 32 Concave part 33 Peripheral wall part

Claims

The first flange is formed on the outer peripheral surface of the one end , the first inner ring raceway is formed on the outer peripheral surface of the intermediate portion, and the cylindrical guide portion is formed on the one end surface, and the hub is formed on the other end of the hub. A step portion having an outer diameter smaller than a portion where the first inner ring raceway is formed, an inner ring formed on the outer peripheral surface to form a second inner ring raceway and externally fitted to the step portion, and the inner peripheral surface A first outer ring raceway facing the first inner ring raceway and a second outer ring raceway facing the second inner ring raceway, an outer ring formed with a second flange on the outer peripheral surface, and the first, first A plurality of rolling elements provided between each of the two inner ring raceways and the first and second outer ring raceways, more than an inner ring that is externally fitted to at least the stepped portion at the other end of the hub. The cylindrical part formed in the protruding part is diametrically moved by a swaging caulking that presses against a pressing mold that swings and displaces. The caulked portion formed by extending caulking towards the inner ring fitted onto the step portion put suppressed towards the stepped surface of the stepped portion, a fitted the inner ring in the stepped portion is connected and fixed to said hub wheel A method of manufacturing a supporting rolling bearing unit , wherein when performing the swaging caulking, the guide portion is disposed on one end side of the hub, and a load based on a pressing force applied from the pressing die to the cylindrical portion is applied. The guide tube portion provided in the holder to be supported is fitted inside, and the tip end surface of the receiving member installed on the inner diameter side of the guide tube portion at a part of the holder is surrounded by the guide portion at one end surface of the hub. This load is applied to the first flange by supporting the load applied to the hub by pressing the cylindrical portion against the pressing die at the inner diameter side of the first flange. Is not added The method of the wheel supporting rolling bearing unit for Me move said rocking.

The rocking caulking which processes a cylindrical part into a caulking part is performed in a state where the first flange is fitted in a peripheral wall part provided on the outer diameter side of the guide cylinder part by a part of the holder. Manufacturing method of rolling bearing unit for wheel support.