JP4055853B2 - Induction tempering device for crankshaft and induction tempering coil body used in the device - Google Patents

Induction tempering device for crankshaft and induction tempering coil body used in the device Download PDF

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JP4055853B2
JP4055853B2 JP2003071226A JP2003071226A JP4055853B2 JP 4055853 B2 JP4055853 B2 JP 4055853B2 JP 2003071226 A JP2003071226 A JP 2003071226A JP 2003071226 A JP2003071226 A JP 2003071226A JP 4055853 B2 JP4055853 B2 JP 4055853B2
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tempering
induction
quenching
heating coil
outer peripheral
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JP2004277821A (en
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精一 沢津橋
啓一 久保
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DKK Co Ltd
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Denki Kogyo Co Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02P10/00—Technologies related to metal processing
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Description

【０００１】
【発明の属する技術分野】
本発明は、クランクシャフトのジャーナル部又はピン部の外周面を焼入処理してから焼戻処理するための高周波焼入焼戻装置に関するものである。
【０００２】
【従来の技術】
図４は、４気筒エンジン用クランクシャフト１を示すものであって、このクランクシャフト１は、中心軸Ｘ（ジャーナル部の軸線と同じ）を軸心とするジャーナル部２ａ，２ｂ，２ｃ，２ｄ，２ｅと、中心軸Ｘに対して偏心した位置にあるピン部３ａ，３ｂ，３ｃ，３ｄと、カウンターウエイト部４ａ，４ｂ，４ｃ，４ｄ，４ｅ，４ｆ，４ｇ，４ｈと、フランジ部５とを鍛造加工により一体に成形して成るものである。複数気筒エンジン用クランクシャフトであればピン部３は複数設けられ、図４に示す４気筒エンジン用クランクシャフト１の場合には、４つのピン部３ａ〜３ｄが設けられる。そして、これらのピン部３ａ〜３ｄは、中心軸Ｘの軸線方向に沿って所定の間隔を隔てた箇所において、互いに隣接するカウンターウエイト部４の間にそれぞれ配置される。また、中心軸Ｘの軸線方向において互いに隣接する各ピン部３ａ〜３ｄは、エンジンの形式に応じて、中心軸Ｘの回りに所定の位相角度だけ異なる角度位置に配設される。なお、図４に示す４気筒エンジン用クランクシャフト１の場合には、左右両端側のピン部３ａ，３ｄ（中心軸Ｙ1 を有する）が互いに同じ位相角度の箇所に配設されると共に、これらのピン部３ａ，３ｄ間のピン部３ｂ，３ｃ（中心軸Ｙ2 を有する）が互いに同じ位相角度の箇所に配設され、左右両端側のピン部３ａ，３ｄと中間位置のピン部３ｂ，３ｃとが互いに１８０度の位相角度をもって配設される。
【０００３】
この種のクランクシャフト１にあっては、従来より、クランクシャフト１のジャーナル部２ａ〜２ｅ及びピン部３ａ〜３ｄの外周面にそれぞれ高周波誘導加熱による焼入処理及び焼戻処理を施すことにより、耐摩耗性並びに疲労強度の向上を図るようにしている。ここで、クランクシャフト１のピン部３ａ〜３ｄ（以下においては、統括的にピン部３と記載する）を高周波誘導加熱する場合を例にとって説明すると、次の通りである。
【０００４】
図５は、ピン部３の外周面Ｓを焼入処理及び焼戻処理に際して高周波誘導加熱するために従来より用いられている高周波焼入焼戻装置８を示すものである。この高周波焼入装置８は、図５に明示するように、真鍮製又は樹脂製の一対の側板１０ａ，１０ｂ間に挟持状態で保持され、かつ、クランクシャフト１の中心軸Ｘを中心に回転駆動されるピン部３の外周面Ｓの上半分部分に対向配置される半開放鞍型の高周波誘導加熱コイル（半開放鞍型コイル）１１と、この高周波誘導加熱コイル１１に高周波電流を供給する高周波電源１２と、前記一対の側板１０ａ，１０に固定された例えば３つのセラミック製又は超硬合金製のガイド部材（チップ部材）１３ａ，１３ｂ，１３ｃとを備えている。
【０００５】
上述の高周波誘導加熱コイル１１は、図５及び図６に示すように、コイル頭部を構成する左右一対の第１及び第２の加熱コイル部分１４ａ，１４ｂと、これらの一対の加熱コイル部分１４ａ，１４ｂとを互いに接続する接続導体部１５ａ，１５ｂ，１５ｃと、一対の接続導体部１５ａ，１５ｂにそれぞれ接続された給電リード部１６ａ，１６ｂとから構成されている。ここで、高周波誘導加熱コイル１１の第１の加熱コイル部分１４ａについて詳述すると、この第１の加熱コイル部分１４ａは、図６に明示するように、互いに平行な一対の円弧状加熱導体部１７ａ，１８ａと、円弧状加熱導体部１７ａの一端と円弧状加熱導体部１８ａの一端とを互いに接続する直線状加熱導体部１９ａと、円弧状加熱導体部１７ａ，１８ａの他端と接続導体部１５ａ，１５ｃの一端とをそれぞれ接続する直線状加熱導体部２０ａ，２１ａとから構成され、全体として湾曲したほぼ矩形形状となされている。また、第２の加熱コイル部分１４ｂも上述の第１の加熱コイル部分１４ａと同様に構成され、一対の加熱コイル部分１４ａ，１４ｂが左右対称の配置関係をもって対応配置されている。なお、図６においては、第２の加熱コイル部分１４ｂの一対の円弧状加熱導体部１７ｂ，１８ｂ、直線状加熱導体部１９ｂ、接続導体部１５ａ，１５ｃ、及び給電リード部１６ｂが図示されているが、既述の直線状加熱導体部２０ａ，２１ａに相当する部分の直線状加熱導体部２０ｂ，２１ｂは、隠れた位置にあるため、図示されていない。
【０００６】
また、上述の給電リード部１６ａ，１６ｂは、高周波電流供給用のトランス（図示せず）を介して高周波電源１２に接続され、この高周波電源１２から所定の高周波電流が高周波誘導加熱コイル１１に供給されるように構成されている。
【０００７】
上述の高周波焼入焼戻装置８によりクランクシャフト１のピン部３の外周面Ｓを焼入処理或いは焼戻処理のために高周波誘導加熱するに際しては、図外の昇降機構により高周波焼入焼戻装置８を所定の待機位置から下降移動させてガイド部材１３ｂを介してピン部３の外周面Ｓ上に載置し、ガイド部材１３ａ〜１３ｃをピン部３の外周面Ｓに当接せしめることにより高周波誘導加熱コイル１１をピン部３の外周面Ｓの上半分部分に対して僅かな間隔を隔てて対向配置する。この状態の下で、クランクシャフト１を図外の回転駆動機構によりクランクシャフト１の中心軸Ｘを中心に回転駆動すると、これに伴いピン部３が前記中心軸Ｘを中心として公転運動する。この際、高周波焼入焼戻装置８が図外の追従機構によりピン部３に追従すると共に、高周波誘導加熱コイル１１の第１及び第２の加熱コイル部分１４ａ，１４ｂが左右対称位置においてピン部３の外周面Ｓの上半分部分に対して常に対向配置された状態を維持する。
【０００８】
このような状態の下で、高周波電源１２から図外のトランス並びに給電リード部１６ａ，１６ｂ、接続導体部１５ａ，１５ｂを順次に介して高周波誘導加熱コイル１１の第１及び第２の加熱コイル部分１４ａ，１４ｂに高周波電流を供給し、これによりピン部３の外周面Ｓを誘導加熱する。次いで、ピン部３の外周面Ｓが所要の焼入温度に誘導加熱された時点で、高周波電源１２から高周波誘導加熱コイル１１への高周波電流の供給を遮断すると共に、ピン部３の外周面Ｓに焼入冷却水噴射手段（図示せず）により焼入冷却水を噴射する。これにより、ピン部３の外周面Ｓが急速冷却されて焼入処理或いは焼戻処理がなされる。
【０００９】
また、図７は、別の形状の半開放鞍型の高周波誘導加熱コイル（半開放鞍型コイル）３０を備える従来の高周波焼入焼戻装置３１を示すものである。この高周波焼入焼戻装置３１は、図７に示すように、真鍮製又は樹脂製の一対の側板１０ａ，１０ｂ間に挟持状態で保持され、かつ、クランクシャフト１の中心軸Ｘを中心に回転駆動されるピン部３（ピン部３ａ〜３ｄ）の外周面Ｓの上半分部分に対向配置される１つの加熱コイル部分２９を有する高周波誘導加熱コイル３０を備えている。なお、その他の構成は、図５の高周波焼入焼戻装置８と同様である。
【００１０】
上述の高周波誘導加熱コイル３０は、図７及び図８に示すように、コイル頭部）を構成する１つの加熱コイル部分２９と、この加熱コイル部分２９に接続された一対の給電リード部３２ａ，３２ｂとから成り、上述の給電リード部３２ａ，３２ｂが高周波電源１２に接続されている。ここで、高周波誘導加熱コイル３０の加熱コイル部分２９の構成について詳述すると、この加熱コイル部分２９は、図８に明示するように、互いに平行な一対の円弧状加熱導体部３３ａ，３３ｂと、円弧状加熱導体部３３ａの一端と円弧状加熱導体部３３ｂの一端とを互いに接続する直線状加熱導体部３４と、円孤状導体部３３ａ，３３ｂの他端と給電リード部３２ａ，３２ｂの一端とをそれぞれ接続する直線状加熱導体部３５ａ，３５ｂとから構成されている。
【００１１】
そして、給電リード部３２ａ，３２ｂは、高周波電流供給用のトランス（図示せず）を介して高周波電源１２に接続されており、この高周波電源１２から所定の高周波電流が高周波誘導加熱コイル３０の加熱コイル部分２９に供給されるように構成されている。
【００１２】
なお、上述の高周波焼入焼戻装置３１は、特に、ピン部３或いはジャーナル部２の直径が小さい小型のクランクシャフトを高周波誘導加熱するのに有効である。その理由を述べると、次の通りである。すなわち、図５の高周波焼入焼戻装置８にあっては高周波誘導加熱コイル１１の頭部が２つの加熱コイル部分１４ａ，１４ｂに２分割されており、円弧状加熱導体部１７ａと１７ｂとが周方向で２つに分割されると共に円弧状加熱導体部１８ａと１８ｂとが周方向で２つに分割されているため、ピン部３ａ〜３ｄ或いはジャーナル部２ａ〜２ｅの直径が小さい場合には、円弧状加熱導体部１５ａ，１５ｂ及び１６ａ，１６ｂの弧長が相対的に短くなり加熱効率が悪くなるが、図７の高周波焼入焼戻装置３１にあっては高周波誘導加熱コイル３０の加熱コイル部分２９の円弧状加熱導体部３３ａ，３３ｂが２つに分割されていないので、ピン部３の外周面Ｓ（又はジャーナル部２の外周面Ｈ）に対向する円弧状加熱導体部３３ａ，３３ｂの弧長が上記の場合よりも相対的に長くなり、これに起因して加熱効率が向上するためである。
【００１３】
上述した図７の高周波焼入焼戻装置３１により、前記クランクシャフト１のピン部３の外周面Ｓを高周波誘導加熱して焼入処理或いは焼戻処理する工程は、前述した高周波焼入装置８による工程と同様であるので、その説明を省略する。
【００１４】
また、上述した高周波焼入或いは高周波焼戻の工程はジャーナル部２の外周面Ｈについても同様であるのでその説明を省略する。
【００１５】
図９（ａ）〜（ｃ）は、高周波誘導加熱コイル１１又は３０の断面形状の代表的な例、並びに、上述の如き焼入工程によりピン部３の外周面Ｓに得られる望ましい（理想的な）硬化層パターンＰ1 ，Ｐ2 ，Ｐ3 をそれぞれ示している。なお、図９（ａ）のようにピン部３の外周面（円筒状外周面）Ｓのみに焼入硬化層パターンＰ1 を形成する焼入は平焼入と称され、図９（ｂ）のようにピン部３の外周面Ｓからその両側のＲ部（円弧状隅部）Ｍに連なる焼入硬化層パターンＰ2 を形成する焼入はフィレットＲ焼入と称され、図９（ｃ）のようにピン部３の外周面Ｓから片側のＲ部Ｍ及びスラスト部（平面部）Ｎに連なる焼入硬化層パターンＰ3 を形成する焼入は片Ｒ焼入と通常呼ばれている。図９（ｃ）の片Ｒ焼入は、クランクシャフト１の両端に位置するジャーナル部、例えば図４に示す４気筒エンジン用クランクシャフト１においては第１ジャーナル部２ａ或いは第５ジャーナル部２ｅに施行されることが多い。
【００１６】
次に、上述した手順で焼入処理を施行したクランクシャフト１については、焼入処理後に焼戻処理にための焼戻加熱を行うが、その焼戻加熱方法としては、電気炉を用いる方法や高周浪誘導加熱による方法が一般的に施行されている。
【００１７】
電気炉による焼戻の場合には、まず、炉内温度を焼戻温度まで昇温しておき、昇温完了した電気炉に全てのジャーナル部２及び全てのピン部３に焼入が施行されたクランクシャフト１を電気炉の大きさに応じて複数本まとめて投入し、炉内温度まで前記クランクシャフトを昇温させた後に、所要時間（通常、１．０時間〜２.５時間程度）保持加熱してから電気炉から取り出して焼戻工程を完了するようにしている。
【００１８】
電気炉による加熱は、炉内雰囲気からの熱伝導によるものであるのでクランクシャフト１の１個体内での温度バラツキは皆無に等しく、従って焼戻硬さのバラツキは焼戻工程においては発生することはない。
【００１９】
また、高周波誘導加熱による焼戻方法としては、既述の焼入用高周波焼入焼戻装置８又は３１を用いて焼戻を行う方法があり、その焼戻方法の場合には、高周波焼入焼戻装置８又は３１を用いて前述した手順により焼入処理を完了したクランクシャフト１のピン部３の外周面Ｓ又はジャーナル部２の外周面Ｈに、再び高周波焼入焼戻装置８の構成要素である高周波誘導加熱コイル１１又は高周波焼入焼戻装置３の構成要素である高周波誘導加熱コイル３０に高周波電源１２より高周波電流を所要時間にわたり供給することにより高周波誘導加熱を行ってピン部３又はジャーナル部２毎に焼戻処理を施すようにしている。ただし、この焼戻方法は、図１０（ａ）に示すような平焼戻に対してのみ有効な方法であり、図１０（ｂ）に示すようなフィレットＲ焼入や図１０（ｃ）に示すような片Ｒ焼入に対しては適用できない。その理由は、従来の焼入用高周波誘導加熱コイルによる焼戻処理では、Ｒ部Ｍの半径が小さい場合はＲ部Ｍを充分に高周波誘導加熱するのは困難であり、またＲ部Ｍの半径が大きい場合はＲ部Ｍが先に昇温してしまい、何れの場合もＲ部Ｍを含んだ連続領域を焼戻時に均一に加熱することができないからである。
【００２０】
また、図１１は高周波誘導加熱による別の焼戻装置３７であり、この焼戻装置３７は、特開２００１−３０３１３４号公報（特許文献１）により提示されているものである。上述の焼戻装置３７は、高周波焼入焼戻装置８又は３１を用いて前述した手順により全てのジャーナル部２及び全てのピン部３に焼入処理が施されたクランクシャフト１を、高周波焼入工程とは別の位置に配置された略円形状ソレノイドタイプの高周波誘導加熱コイル３８により完全に取り囲まれた位置に配置して、焼入されていないカウンターウエイト部４及びフランジ部５等も含めてクランクシャフト１の全体を所要の焼戻温度まで一括して高周波誘導加熱を行って焼戻処理をするようにしたものである。
【００２１】
このような焼戻装置３７によれば、平焼入、フィレットＲ焼入によらず充分な焼戻効果を達成することが可能であり、また前述した電気炉による焼戻方法と比較して昇温時間及び保持（均熱）時間が短い（合計で６０秒〜２００秒程度）ため、疲労強度に関係する焼入された部位の圧縮残留応力が除去される度合いを少なく抑えることができて充分な圧縮残留応力を保持することが可能である。そして、加熱時間が短いことより、焼入から焼戻の工程を順次に行うような設備のインライン化が可能である。
【００２２】
【特許文献１】
特開２００１−３０３１３４号公報
【００２３】
【発明が解決しようとする課題】
しかしながら、電気炉による加熱は、炉内雰囲気からの熱伝導による加熱であるため、加熱時間（昇温時間と保持時間の合計時間）が高周波誘導加熱の場合と比べて非常に長くなるためインライン化は困難である。また、１回の処理量を増加させようとすると、電気炉の容積を大きくせざるを得ず、設備の設置面積が増大するといった問題点がある。さらに、上述したように長時間加熱であることに起因して、高周波焼入により焼入部であるジャーナル部２及びピン部３の外周面Ｈ及びＳに発生した圧縮残留応力が開放されて低減してしまうため、クランクシャフト１の疲労強度が低下してしまうといった問題点もある。そして、クランクシャフト１を焼戻処理する前に炉内雰囲気を焼戻温度まで昇温させるための時間並びに電力が必要であり、生産効率及びエネルギー効率が低いのが実状である。
【００２４】
焼入用高周波焼入焼戻装置８又は３１を用いてジャーナル部２又はピン部３の高周波焼入と高周波焼戻を連続して行う方法は、平焼入及び平焼戻に関しては従来より採用されている（図１０（ａ）参照）。平焼入の場合には、図１０（ａ）に示すように、焼入時と焼戻時における加熱条件並びに熱伝導の程度の違いにより焼入加熱時の加熱領域α1 ，α2 の幅に比べて焼戻加熱時の加熱領域α3 、α4 の幅が狭いため、焼入用半開放鞍型加熱コイル１１或いは３０を用いて短時間で高周波焼戻加熱を行うと、前記焼入用半開放鞍型加熱コイル１１或いは３０に対向する部分の僅かな一部分の領域にしか焼戻効果が現れない。この現象は、焼戻加熱時に焼入用高周波誘導加熱コイル１１或いは３０に供給する高周波電流値を増大させても変化せず、高周波電流値を増大させた分だけ、焼戻加熱領域α3 、α4 のみ過熱されて過剰に焼戻された状態になり、その領域は表面硬さが低下し過ぎてしまう一方、上述の過剰焼戻された領域の周辺には殆ど焼戻効果の現れない領域が存在することになる。その結果、焼戻処理完了後の硬化層各部での表面硬さが一定しないといった熱処理品質上の問題を生じる。
【００２５】
この理由について述べると、次の通りである。まず、高周波焼入されたクランクシャフト１を焼戻処理する際の焼戻温度の設定は、通常１５０℃〜２８０℃の範囲である。この温度領域における被加熱物表面の近傍に流れる誘導電流の浸透深さは、例えば周波数が２０ＫＨｚの場合は、約０．１ｍｍである。一方、クランクシャフトの材質である鋼の磁気変態点（約７６０℃）以上の焼入温度領域における浸透深さは、２０ＫＨｚの場合は、約３．５ｍｍであり、焼戻温度領域における浸透深さにくらべて非常に大きいため、焼入時と焼戻時とでは同一の高周波誘導加熱コイルを用いても加熱領域の大きさが異なるのである。因みに、クランクシャフト１のジャーナル部及びピン部に形成する焼入硬化層深さは、一般的に、３．０ｍｍ〜５．０ｍｍ程度である。
【００２６】
従って、前記焼入用高周波焼入装置８或いは３１を用いて高周波焼戻を行う場合、短時間加熱すると上述したような熱処理品質上の問題を解決することが困難である。熱処理品質上の問題を解決し、充分な焼戻効果を得るためには、誘導加熱の時間の他に熱伝導に要する時間（放冷時間）を充分に設け、電流浸透深さが非常に小さく、焼入硬化層に対して狭い領域を誘導加熱することで発生した熱を、熱伝導により浸透深さ以上の硬化層内部を昇温させることが必要になるが、焼戻処理に要する時間が長くなることに起因して、クランクシャフト１の総熱処理時間が長くなり、生産性が低下するという問題がある。
【００２７】
また、焼入硬化層領域が平焼入よりもさらに広いフィレットＲ焼入硬化層を形成したジャーナル部２又はピン部３の高周波焼入コイル体による高周波焼戻は上述した理由により焼戻に要する時間がさらに長くなる上に、平焼入の焼入硬化層を焼戻する場合よりも温度差が発生し易く、従って焼戻後の硬さめバラツキが大きくなるという問題がある。
【００２８】
また、高周波誘導加熱による別の焼戻方法として、全てのジャーナル部２及び全てのピン部３に焼入が施行されたクランクシャフト１を、カウンターウエイト部４を含む非焼入領域も含めて、既述の略円形状ソレノイドタイプの高周波誘導加熱コイル３８（図１１参照）によって完全に取り囲みクランクシャフト１を一括して高周波誘導加熱を行って焼戻処理をする方法もあるが、被焼戻対象となるクランクシャフト１の寸法が大きくなり例えば建設機械や船舶用のクランクシャフト（２．０ｍ以上）のものになるとソレノイドタイプの高周波誘導加熱コイル３８も相応に大型になり、その結果、焼戻装置の全体が大型になり設備の設置面積が大きくなるといった問題がある。
【００２９】
本発明は、かかる点に鑑みてなされたものであって、その目的は、上述の如き種々の問題点を解消し、短時間で充分な焼戻効果を得ることが可能でかつコンパクトなクランクシャフトの高周波焼入焼戻装置及びその装置に用いられる高周波焼戻コイル体を提供することにある。
【００３０】
【課題を解決するための手段】
上記目的を達成するために、本発明では、クランクシャフトのジャーナル部又はピン部の外周面に高周波焼入及び高周波焼焼戻を施行するための高周波焼入焼戻装置において、焼入用半開放鞍型高周波誘導加熱コイルを有する高周波焼入コイル体と、焼戻用半開放鞍型高周波誘導加熱コイルを有する高周波焼戻コイル体とをそれぞれ備え、前記ジャーナル部又はピン部の中心軸を挟む２方向から移動される前記焼入用半開放鞍型高周波誘導加熱コイルと前記焼戻用半開放鞍型高周波誘導加熱コイルとにより前記ジャーナル部又はピン部の外周面のほぼ全周を取り囲んで、前記焼入用半開放鞍型高周波誘導加熱コイル及び前記焼戻用半開放鞍型高周波誘導加熱コイルを前記ピン部又はジャーナル部の外周面に対向配置し、この状態の下で、前記クランクシャフトをその中心軸を中心に回転駆動するのに伴って自転運動する前記ジャーナル部の外周面、又は、前記クランクシャフトの中心軸を中心として公転運動を行う前記ピン部の外周面に前記高周波焼入コイル体を追従させながら高周波焼入を行い、次いで前記高周波焼戻コイル体を前記ジャーナル部又はピン部の外周面に追従させながら高周波焼戻するようにしている。
また、本発明では、前記高周波焼入コイル体及び前記高周波焼戻コイル体を、高周波電流経路を切り換える切換器を介して共通の高周波電源にそれぞれ接続し、高周波焼入工程においては、前記切換器により前記高周波焼入コイル体の高周波焼入用半開放鞍型高周波誘導加熱コイルに高周波電流を供給するようにし、高周波焼戻工程においては、前記切換器により前記高周波焼戻コイル体の焼戻用半開放鞍型高周波誘導加熱コイルに高周波電流を供給するようにしている。
また、本発明では、前記高周波焼入コイル体及び前記高周波焼戻コイル体を、それぞれ別の高周波電源に接続し、前記高周波焼入コイル体の焼入用半開放鞍型高周波誘導加熱コイルに高周波電流を供給している期間中に前記高周波焼戻コイル体の焼戻用半開放鞍型高周波誘導加熱コイルにも高周波電流を供給可能としている。
また、本発明では、上述の如きクランクシャフトの高周波焼入焼戻装置によって平焼入を施したクランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための、前記高周波焼入焼戻装置を構成する高周波焼戻コイル体において、前記高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、前記クランクシャフトの中心軸に沿う方向における幅が広く、かつ、前記ジャーナル部又はピン部の外周面との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記ジャーナル部又はピン部の外周面との間の距離よりも大きく設定されるように構成している。
また、本発明では、上述の如き構成のクランクシャフトの高周波焼入焼戻装置によってフィレットＲ焼入を施した前記クランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための、前記高周波焼入焼戻装置を構成する高周波焼戻コイル体において、前記高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、前記ジャーナル部又はピン部の外周面との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記外周面との間の距離よりも大きく、かつ、前記ジャーナル部又はピン部の外周面から連なるＲ部を含んで前記ジャーナル部又はピン部に対して垂直に立ち上がる部位との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記部位との間の距離との間の距離よりも大きく設定されるように構成している。
また、本発明では、上述の如き構成のクランクシャフトの高周波焼入焼戻装置によって片Ｒ焼入を施した、前記クランクシャフトの端部に位置するジャーナル部に対して高周波焼戻処理を行うための、前記高周波焼入焼戻装置を構成する高周波焼戻コイル体において、前記高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、前記ジャーナル部の外周面との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記外周面との間の距離との間の距離よりも大きく、かつ、前記ジャーナル部の外周面から連なるＲ部を含んで前記ジャーナル部又はピン部に対して垂直に立ち上がる部位との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記部位との間の距離より大きく、かつ、前記焼戻用半開放鞍型高周波誘導加熱コイルの前記外周面のみに対向している加熱導体部の前記クランクシャフトの中心軸に沿う方向の幅が、前記焼入用半開放鞍型高周波誘導加熱コイルの前記外周面のみに対向している加熱導体部の前記クランクシャフトの中心軸に沿う方向の幅より大きく設定されるように構成している。
【００３１】
【発明の実施の形態】
以下に、本発明の実施の形態を図１〜図３を参照して説明する。なお、図１〜図３において、図４〜図１１と同様の部分には同一の符号を付して重複する説明を省略する。
【００３２】
図１は、本発明の一実施形態に係る高周波焼入焼戻装置４０を示すものであって、この高周波焼入焼戻装置４０は、焼入用半開放鞍型高周波誘導加熱コイル３０ａ（以下において、焼入用加熱コイル３０ａと記載する）を有する高周波焼入コイル体Ｊと、焼戻用半開放鞍型高周波誘導加熱コイル３０ｂ（以下において、焼戻用加熱コイル３０ｂと記載する）を有する高周波焼戻コイル体Ｋとをそれぞれ備えている。すなわち、本装置４０は、真鍮製又は樹脂製の一対の側板４１ａ，４１ｂ間に挟持状態で保持された高周波焼入コイル体Ｊとしての焼入用加熱コイル３０ａと、真鍮製又は樹脂製の一対の側板４２ａ，４２ｂ間に挟持状態で保持された高周波焼戻コイル体Ｋとしての焼戻用加熱コイル３０ｂとをそれぞれ備えている。
【００３３】
上述の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂは、それぞれ、図８の高周波誘導加熱コイル３０と同様に構成されたコイル体、すなわち高周波誘導加熱コイル３０と同様に構成された加熱コイル部分２９を有するコイル体であり、互いに同一の形状に構成されている。
【００３４】
また、互いに同一の形状を有する焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂは、左右位置において互いに反対向きとなされて配置され、ピン部３の中心軸Ｙを挟む左右２方向から移動されて互いに対向配置されるように構成されている。この場合、焼入用加熱コイル３０ａと焼戻用加熱コイル３０ｂとが接触しないように配置しなければならないため、図１に示す如く焼入用加熱コイル３０ａの両端部と焼戻用加熱コイル３０ｂの両端部との間に僅かな間隔が設けられ、焼入用加熱コイル３０ａと焼戻用加熱コイル３０ｂとによりピン部３の外周面のほぼ全周（完全な全周ではなく、ピン部３の外周面の全周の大部分）が取り囲まれるようになっている。かくして、一対の円弧状加熱導体部３３ａ，３３ｂと、直線状加熱導体部３４と、一対の直線状加熱導体部３５ａ，３５ｂとから成る焼入用加熱コイル３０ａの加熱コイル部分２９が、クランクシャフト１の中心軸Ｘを中心に回転駆動されるクランクシャフト１のピン部３の外周面Ｓの一方側の側面半分部分に対向配置されるように構成されると共に、焼戻用加熱コイル３０ｂの加熱コイル部分２９が、クランクシャフト１の中心軸Ｘを中心に回転駆動されるクランクシャフト１のピン部３の外周面Ｓの他方側の側面半分部分に対向配置されるようになっている。
【００３５】
また、図１に示すように、第１の高周波誘導加熱コイル３０ａの給電リード部３２ａ，３２ｂは、第１及び第２の高周波電流供給用トランス（図示せず）にそれぞれ接続され、これらのトランスには、高周波電流経路を切り換える切換器５０を介して高周波電源１２が接続されている。従って、焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂには、上述の単一の高周波電源１２から切換器５０及び図外のトランスをそれぞれ介して所定の高周波電流が択一的に供給されるように構成されている。すなわち、焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂの何れか一方にのみ高周波電流が選択的に供給されるようになっている。
【００３６】
さらに、焼入用加熱コイル３０ａが取付けられている一対の側板４１ａ，４１ｂ間には、焼入用加熱コイル３０ａに対応する箇所に一対のガイド部材４３ａ，４３ｂが取付けられており、焼戻用加熱コイル３０ｂが取付けられている一対の側板４２ａ，４２ｂ間には、焼戻用加熱コイル３０ｂに対応する箇所に一対のガイド部材４４ａ，４４ｂが取付けられている。かくして、前記２台の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂは、これらのガイド部材４３ａ，４３ｂ及び４４ａ，４４ｂを介して、加熱対象であるピン部３の中心軸Ｙを挟む左右２方向からこのピン部３の外周面Ｓに対して僅かな隙間を隔てて対向配置され、これに伴いピン部３の外周面Ｓのほぼ全周が焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂの加熱コイル部分２９にて取り囲まれた状態となるように構成されている。
【００３７】
なお、図２（ａ），（ｂ）及び（ｃ）は、前述した高周波焼入焼戻装置４０の図１中のＡ−Ａ断面を示すものであって、図２（ａ）は、ピン部３の外周面Ｓを平焼入及び平焼戻するための高周波焼入焼戻装置としての平焼入用加熱コイル３０ａ及び平焼戻用加熱コイル３０ｂの断面図、図２（ｂ）は、ピン部３の外周面ＳをフィレットＲ焼入及びフィレットＲ焼戻するための高周波焼入焼戻装置としてのフィレットＲ焼入用加熱コイル３０ａ及びフィレットＲ焼戻用加熱コイル３０ｂを備えた高周波焼入焼戻装置４０の断面図、図２（ｃ）は、クランクシャフト１の端部に位置する第１ジャーナル部２ａ（或いは第５ジャーナル部２ｅ）の外周面Ｈを片Ｒ焼入及び片Ｒ焼戻するための高周波焼入焼戻装置としての片Ｒ焼入用加熱コイル３０ａ及び片Ｒ焼戻用加熱コイル３０ｂの断面図である。
【００３８】
図２（ａ），（ｂ）及び（ｃ）の場合には、焼入処理時及び焼戻処理時における焼入用加熱コイル３０ａの円弧状加熱導体部３３ａ，３３ｂとピン部３の外周面Ｓ又はジャーナル部２の外周面Ｈとの間の距離Ｌ1 と、焼戻用加熱コイル３０ｂの円弧状加熱導体部３３ａ，３３ｂとピン部３の外周面Ｓ又はジャーナル部２の外周面Ｈとの間の距離Ｌ2 との関係は、Ｌ1 ＜Ｌ2 となるように設定されている。さらに、図２（ａ）及び（ｃ）の場合には、平焼入，フィレットＲ焼入，或いは片Ｒ焼入用の高周波焼入焼戻装置４０の焼入用加熱コイル３０ａの一対の円弧状加熱導体部３３ａ，３３ｂとピン部３のスラスト部Ｎ（円筒状外周面から垂直に立ち上がる部位としての側面）との間の距離ｄ1 と、焼戻用加熱コイル３０ｂの一対の円弧状加熱導体部３３ａ，３３ｂとピン部３のスラスト部Ｎとの間の距離ｄ2 は、それぞれ、ｄ1 ＜ｄ2 なる関係となるように設定されている。
【００３９】
また、図２（ａ）及び（ｃ）にそれぞれ示す平焼入及び平焼戻用の高周波焼入焼戻装置４０に設置される焼戻用加熱コイル３０ｂの円弧状加熱導体部３３ａの幅Ｗ2 は、焼入用加熱コイル３０ａの円弧状加熱導体部３３ａの幅Ｗ1 に比べて幅広に形成されると共に（Ｗ1 ＜Ｗ2 ）、これにより焼入用加熱コイル３０ａで焼戻加熱を行う場合（加熱領域α1 及びα2 ）よりも加熱領域α3 及びα4 が広くなるように構成されている。なお、図２（ｃ）において、焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂの円弧状加熱導体部３３ａは、ジャーナル部２ａの外周面Ｈのみに対向している加熱導体部（Ｒ部Ｍ及びスラスト部Ｎには対向していない加熱導体部）である。
【００４０】
焼入処理及びこれに引き続く焼戻処理を行う時には、以上に述べたような配置関係で２台の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂをピン部３の外周面Ｓ又はジャーナル部２ａの外周面Ｈに対向配置した状態の下で、クランクシャフト１を図外の回転駆動機構によりその中心線Ｘの回りに回転駆動させ、この回転駆動に伴い中心軸Ｘの回りに公転運動をするピン部３又は中心軸Ｘを中心に自転運動するジャーナル部２ａに２台の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂを図外の追従機構によって追従させる。なお、この際、台の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂは、ピン部３の外周面Ｓ又はジャーナル部２ａの外周面Ｈの側方半分部分に各々常に所定間隔をもって対向配置された状態が維持される。
【００４１】
このような状態の下で、まず切換器５０をオフ状態から第１のオン状態に切り換えることにより、高周波電源１２から図外の第１のトランスを介して焼入用加熱コイル３０ａのみに高周波電流を供給し、これに応じてピン部３の外周面Ｓ又はジャーナル部２ａの外周面Ｈを高周波誘導加熱する。次いで、前記外周面Ｓ又はＨが所要の焼入温度に誘導加熱された時点で、切換器５０を元のオフ状態に切り換えることにより、高周波電源１２から焼入用加熱コイル３０ａへの高周波電流の供給を遮断し、所要の焼入温度に加熱された前記外周面Ｓ又はＨに焼入冷却水噴射手段（図示せず）により焼入冷却液を噴射する。これにより、前記外周面Ｓ又はＨが急速冷却されて焼入硬化層が形成される。
【００４２】
このような焼入処理に引き続いて、焼戻処理を行う。この際には、切換器５０をオフ状態から第２のオン状態に切り換えることにより、高周波電源１２から図外の第２のトランスを介して焼戻用加熱コイル３０ｂのみに高周波電流を供給し、これに応じてピン部３の外周面Ｓ又はジャーナル部２ａの外周面Ｈを高周波誘導加熱する。次いで、前記外周面Ｓ又はＨが所要の焼戻温度に誘導加熱された時点で、切換器５０を元のオフ状態に切り換えることにより、高周波電源１２から焼戻用加熱コイル３０ｂへの高周波電流の供給を遮断し、所要の焼入温度に加熱された前記外周面Ｓ又はＨに焼入冷却水噴射手段（図示せず）により焼入冷却液を噴射する。これにより、前記外周面Ｓ又はＨを常温まで冷却させて焼戻処理を完了する。
【００４３】
なお、切換器５０による焼入用加熱コイル３０ａから焼戻用加熱コイル３０ｂへの通電切換を焼入工程における加熱終了後の焼入冷却中に行うようにしても良く、このようにすることによって熱処理時間の短縮を図ることが可能である。
【００４４】
上述の如き高周波焼入焼戻装置４０によれば、次のような作用効果を奏することができる。すなわち、図２（ａ）に示す平焼入用の高周波焼入焼戻装置４０にあっては、焼戻用加熱コイル３０ｂの円弧状加熱導体部３３ａ，３３ｂの幅Ｗ2 を焼入用加熱コイル３０ａの円弧状加熱導体部３３ａ，３３ｂの幅に比べて幅広にしてあるため（焼戻用加熱コイル３０ｂの幅Ｗ2 を焼入用加熱コイル３０ａの幅Ｗ1 に対してＷ2 ＞Ｗ1 としているため）、焼入用加熱コイル３０ａで焼戻加熱を行う場合（加熱領域α1 ，α2 ）よりも焼戻加熱時における加熱領域α３及びα４が広くなる。さらに、焼戻用加熱コイル３０ｂの２つの円弧状加熱導体部３３ａ，３３ｂとピン部３の外周面Ｓとの間の距離Ｌ2 を、焼入用加熱コイル３０ａの２つの円弧状加熱導体部３３ａ，３３ｂとピン部３の外周面Ｓとの間の距離Ｌ1 よりも大きく設定しているので（Ｌ2 ＞Ｌ1 ）、焼入用加熱コイル３０ａによる加熱と比較して磁束密度の低い位置で緩やかな昇温速度で、内部への熱伝導を伴いながらにピン部３の外周面Ｓを焼戻加熱することにより、前記外周面Ｓ又はＨ並びにその周辺部分を均等に昇温させることができて、焼入硬化層に内部への熱移動を均一に行なうことができ、従って焼戻処理後の硬さのバラツキを抑えることが可能となる。
【００４５】
また、図２（ｂ）に示すフィレットＲ焼入用の高周波焼入焼戻装置４０にあっては、上記と同様にＬ2 ＞Ｌ1 とし、かつ、焼戻用加熱コイル３０ｂの一対の円弧状加熱導体部３３ａ，３３ｂとピン部３のスラスト部Ｎとの間の距離ｄ2 を、焼入用加熱コイル３０ａの一対の円弧状加熱導体部３３ａ，３３ｂとピン部３のスラスト部Ｎとの間の距離ｄ1 よりも大きく設定しているので（ｄ2 ＞ｄ1 ）、焼戻用加熱コイル３０ｂの方がコイル３０ａに比ベてピン部３より遠い位置にあるため、上述した平焼入の場合と同じく焼入用加熱コイル３０ａによる加熱と比較して磁束密度の低い位置で加熱を行うこととなり、焼入時の加熱領城α1 ，α2 に比べて焼戻時の加熱領域α3 ，α4 は広くなる。従って、緩やかな昇温速度で、内部への熱伝導を伴いながらにピン部３の外周面Ｓを焼戻加熱することとなるため、前記外周面Ｓ及びその周辺部分を均等に昇温させることができて、焼入硬化層の内部への熱移動を均一に行うことができ、従って焼戻後の硬さのバラツキを抑えることが可能となる。
【００４６】
また、図２（ｃ）に示すフィレットＲ焼入用の高周波焼入焼戻装置４０にあっては、上述した平焼入並びにフィレットＲ焼入の焼戻の場合と同様に、第１ジャーナル部２ａの外周面Ｈ及びＲ部Ｍの近傍の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂの位置関係は、焼入用加熱コイル３０ａより焼戻用加熱コイル３０ｂの方が前記外周面Ｈに対してより遠くに離れており、磁束密度の低い位置で加熱を行うようにしているため、焼入時の加熱領域α1 ，α2 に比べて焼戻時の加熱領域α3 ，α4 は広くなる。その結果、緩やかな昇温速度で、内部への熱伝導を伴いながらに第１ジャーナル部２ａ（或いは第５ジャーナル部２ｅ）の外周面Ｈを焼戻加熱することとなるため、ジャーナル部２ａの外周面Ｈ及びその周辺部分を均等に昇温させることができて、焼入硬化層の内部への熱移動を均一に行うことができ、従って焼戻後の硬さのバラツキを抑えることが可能となる。
【００４７】
図３は、本発明の別の実施形態に係る高周波焼入焼戻装置４０´を示すものであって、本装置４０´の構成は、図１に示すものと全く同一であるが、焼入用加熱コイル３０ａには第１の高周波電源１２ａが接続されると共に、焼戻用加熱コイル体３０ｂには第２の高周波電源１２ｂが接続されている。なお、第１及び第２の高周波電源１２ａ，１２ｂの発振周波数は同一であってよい。
【００４８】
上述のように構成することにより、焼入用加熱コイル３０ａと焼戻用加熱コイル３０ｂに同時に高周波電流を供給することができるため、高周波焼入焼戻装置４０´によれば、以下のような効果を奏することができる。
（１） 高周波焼入時に、第１の高周波電源１２ａから焼入用加熱コイル３０ａに高周波電流を供給すると同時に、第２の高周波電源１２ｂから焼戻用加熱コイル３０ｂに高周波電流を供給して焼入加熱を行うようにすれば、焼戻用加熱コイル３０ｂにより被加熱領域の全体を予熱する効果を得ることができるため、特に大型のクランクシャフト１に焼入を行う場合には、加熱時間を短縮することが可能である。また、ジャーナル部２又はピン部３の外周面Ｈ又はＳのほぼ２分の１の周面だけを加熱する従来の高周波焼入装置と異なり、そのほぼ全周を２台の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂにて取り囲んで高周波誘導加熱するようにしているので、均熱するまでの時間を短縮できるため、クランクシャフト１の焼入後の曲がりを小さく抑えることができる。
（２） 高周波焼入完了後の高周波焼戻工程において、焼戻用加熱コイル３０ｂに高周波電流を供給すると同時に、焼入用加熱コイル３０ａに高周波電流を供給して焼戻加熱を行うようにすれば、焼入の場合と同様に焼戻加熱時間の短縮が可能である。
【００４９】
また、上述の高周波焼入焼戻装置４０，４０´によれば、２台の焼入用加熱コイル３０ａ及び焼戻用加熱コイル３０ｂを備えるだけで良いので、図１１に示すような大型の焼戻用高周波誘導加熱コイル３８を備える必要がなく、装置全体をコンパクトにすることが可能である。
【００５０】
以上、本発明の実施例につき述べたが、本発明はこの実施例に限定されるものではなく、本発明の技術的思想に基づいて各種の変形及び変更が可能である。例えば、既述の２つの実施形態においては焼入用加熱コイル３０ａと焼戻用加熱コイル３０ｂとして、従来の高周波焼入焼戻装置３１を構成する高周波誘導加熱コイル３０と同等の構造のものを用いるようにしたが、従来の高周波焼入焼戻装置８を構成する高周波誘導加熱コイル１１に置き換え可能である。さらに、高周波焼入焼戻装置４０´にあっては、焼入用高周波加熱コイル３０ａに接続される高周波電源１２ａの発振周波数に比べて、焼戻用加熱コイル３０ｂに接続される高周波電源１２ｂの発振周波数を低くしても良い。
【００５１】
【発明の効果】
請求項１に記載の本発明は、焼入用半開放鞍型高周波誘導加熱コイルを有する高周波焼入コイル体と、焼戻用半開放鞍型高周波誘導加熱コイルを有する高周波焼戻コイル体とをそれぞれ備え、クランクシャフトのジャーナル部又はピン部の中心軸を挟む２方向から移動される焼入用半開放鞍型高周波誘導加熱コイルと焼戻用半開放鞍型高周波誘導加熱コイルとにより前記ジャーナル部又はピン部の外周面のほぼ全周を取り囲んで高周波焼入した後に高周波焼戻を行うようにしたものであるから、高周波焼入及び高周波焼戻を１台の装置で行うことができるため高周波焼入装置とは別に高周波焼戻装置を設ける必要がなく、従って装置（設備）をコンパクトにかつ安価にできると共に、装置の設置面積を小さくすることが可能である。そして、焼戻専用の高周波誘導加熱コイルによって焼戻加熱を行うようにしているため、短時間で充分な焼戻品質を得ることができ、生産性を向上させることが可能となる。
【００５２】
また、請求項２に記載の本発明は、高周波焼入コイル体及び高周波焼戻コイル体を切換器を介して共通の高周波電源にそれぞれ接続して、高周波焼入用半開放鞍型高周波誘導加熱コイル及び焼戻用半開放鞍型高周波誘導加熱コイルに高周波電流を選択的に供給するようにしたものであるから、高周波電源が１台でよく、装置を安価にすることが可能である。
【００５３】
また、請求項３に記載の本発明は、高周波焼入コイル体及び高周波焼戻コイル体を、それぞれ別の高周波電源に接続し、高周波焼入コイル体の焼入用半開放鞍型高周波誘導加熱コイルに高周波電流を供給している期間中に前記高周波焼戻コイル体の焼戻用半開放鞍型高周波誘導加熱コイルにも高周波電流を供給可能にしたものであるから、２台の焼入用半開放鞍型高周波誘導加熱コイル及び焼戻用半開放鞍型高周波誘導加熱コイルにより焼入加熱並びに焼戻加熱を行うことにより、クランクシャフトの熱処理時間を短縮することが可能であり、生産性を向上させることが可能となる。
【００５４】
また、請求項４に記載の本発明は、平焼入を施したクランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための高周波焼戻コイル体において、高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、クランクシャフトの中心軸に沿う方向における幅が広く、かつ、ジャーナル部又はピン部の外周面との間の距離が、焼入用半開放鞍型高周波誘導加熱コイルとジャーナル部又はピン部の外周面との間の距離よりも大きく設定されるように構成したものであるから、緩やかな昇温速度で、被加熱部の内部への熱伝導を伴いながらジャーナル部又はピン部の外周面を高周波誘導加熱することができ、ジャーナル部又はピン部の外周面及びその周辺部分が均等に昇温されることとなって焼入硬化層の内部への熱移動が均一に行われるため、焼戻処理後の硬さのバラツキを抑えることが可能となる。
【００５５】
また、請求項５に記載の本発明は、フィレットＲ焼入を施したクランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための高周波焼戻コイル体において、高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、ジャーナル部又はピン部の外周面との間の距離が、焼入用半開放鞍型高周波誘導加熱コイルと前記外周面との間の距離よりも大きく、かつ、ジャーナル部又はピン部の外周面から連なるＲ部を含んでジャーナル部又はピン部に対して垂直に立ち上がる部位（スラスト部）との間の距離が、焼入用半開放鞍型高周波誘導加熱コイルと前記部位との間の距離との間の距離よりも大きく設定されるように構成したものであるから、緩やかな昇温速度で、被加熱部の内部への熱伝導を伴いながらジャーナル部又はピン部の外周面を高周波誘導加熱することができ、ジャーナル部又はピン部の外周面及びその周辺部分が均等に昇温されることとなって焼入硬化層の内部への熱移動が均一に行われるため、焼戻処理後の硬さのバラツキを抑えることが可能となり、従来では困難とされていたフィレットＲ焼入部の高周波焼戻処理が可能となる。また、クランクシャフトの全体を加熱することなく、半開放鞍型高周波誘導加熱コイルを用いて各ジャーナル部又はピン部毎に誘導加熱による焼戻処理ができるため、フィレットＲ焼入が施されたクランクシャフトを焼戻処理するための従来の装置に比べて、装置が安価になり、装置全体の小型化（コンパクト化）が可能となる。
【００５６】
また、請求項６に記載の本発明は、片Ｒ焼入を施したクランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための高周波焼戻コイル体において、高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、ジャーナル部の外周面との間の距離が、焼入用半開放鞍型高周波誘導加熱コイルと前記外周面との間の距離との間の距離よりも大きく、かつ、ジャーナル部の外周面から連なるＲ部を含んでジャーナル部又はピン部に対して垂直に立ち上がる部位との間の距離が、焼入用半開放鞍型高周波誘導加熱コイルと部位との間の距離より大きく、かつ、焼戻用半開放鞍型高周波誘導加熱コイルの前記外周面のみに対向している加熱導体部のクランクシャフトの中心軸に沿う方向の幅が、焼入用半開放鞍型高周波誘導加熱コイルの前記外周面のみに対向している加熱導体部のクランクシャフトの中心軸に沿う方向の幅より大きく設定されるように構成したものであるから、緩やかな昇温速度で、被加熱部の内部への熱伝導を伴いながらジャーナル部又はピン部の外周面を高周波誘導加熱することができ、ジャーナル部又はピン部の外周面及びその周辺部分が均等に昇温されることとなって焼入硬化層の内部への熱移動が均一に行われるため、焼戻処理後の硬さのバラツキを抑えることが可能となり、従来では困難とされていた片Ｒ焼入部の高周波焼戻処理が可能となる。また、クランクシャフトの全体を加熱することなく、半開放鞍型高周波誘導加熱コイルを用いて各ジャーナル部又はピン部毎に誘導加熱による焼戻処理ができるため、フィレットＲ焼入が施されたクランクシャフトを焼戻処理するための従来の装置に比べて、装置が安価になり、装置全体の小型化（コンパクト化）が可能となる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係るクランクシャフトの高周波焼入焼戻装置の側面図である。
【図２】図１の高周波焼入焼戻装置のＡ−Ａ線拡大断面図であって、図２（ａ）は平焼入における焼入用加熱コイル及び焼戻用加熱コイルの断面並びに加熱領域を示す図、図２（ｂ）はフィレットＲ焼入における焼入用加熱コイル及び焼戻用加熱コイルの断面並びに加熱領域を示す図、図２（ｃ）は片Ｒ焼入における焼入用加熱コイル及び焼戻用加熱コイルの断面並びに加熱領域を示す図である。
【図３】本発明の別の実施形態に係るクランクシャフトの高周波焼入焼戻装置の側面図である。
【図４】４気筒エンジン用クランクシャフトの斜視図である。
【図５】従来のクランクシャフトの高周波誘導加熱装置の側面図である。
【図６】図５の高周波誘導加熱装置の構成要素である高周波誘導加熱コイルの概斜視図である。
【図７】従来の別のクランクシャフトの高周波誘導加熱装置の側面図である。
【図８】図７の高周波誘導加熱装置の構成要素である別の高周波誘導加熱コイルの斜視図である。
【図９】図９（ａ）は平焼入用加熱コイル及び平焼戻用加熱コイルの断面形状並びにピン部に形成される好ましい焼入硬化層を示す断面図、図９（ｂ）はフィレットＲ焼入用加熱コイル及びフィレットＲ焼入用加熱コイルの断面形状並びにピン部に形成される好ましい焼入硬化層を示す断面図、図９（ｃ）は片Ｒ焼入用加熱コイルイ及び片Ｒ焼戻用加熱コイルの断面形状並びにピン部に形成される好ましい焼入硬化層を示す断面図である。
【図１０】図５におけるＢ−Ｂ線拡大断面図（図７のＣ−Ｃ線拡大断面図に対応）であって、図１０（ａ）はピン部の平焼入及び平焼戻のための高周波誘導加熱コイルの断面形状並びに平焼入時及び平焼戻時の加熱領域を示す図、図１０（ｂ）はピン部のフィレットＲ焼入及びフィレットＲ焼戻のための高周波誘導加熱コイルの断面形状並びにフィレットＲ焼入時及びフィレットＲ焼戻時の加熱領域を示す図、図１０（ｃ）は第１ジャーナル部の片Ｒ焼入及び片Ｒ焼入のための高周波誘導加熱コイルの断面形状並びに片Ｒ焼入時及び片Ｒ焼戻時の加熱領域を示す図である。
【図１１】略円形状ソレノイドタイプの高周波誘導加熱コイルを備えたクランクシャフトの高周波焼戻装置の概観図である。
【符号の説明】
１ ４気筒エンジン用クランクシャフト
２（２ａ〜２ｅ） ジャーナル部
３（３ａ〜３ｄ） ピン部
１２ 高周波電源
１２ａ 第１の高周波電源
１２ｂ 第２の高周波電源
１７ａ，１７ｂ，１８ａ，１８ｂ 円弧状加熱導体部
３０ａ 焼入用半開放鞍型高周波誘導加熱コイル（焼入用加熱コイル）
３０ｂ 焼戻用半開放鞍型高周波誘導加熱コイル（焼戻用加熱コイル）
３３ａ，３３ｂ 円弧状加熱導体部
４０，４０´ 高周波焼入焼戻装置
４３ａ，４３ｂ，４４ａ，４４ｂ ガイド部材
５０ 切換器
５１ａ〜５１ｄ ガイド部材
Ｊ 高周波焼入コイル体
Ｋ 高周波焼戻コイル体
Ｈ ジャーナル部の外周面
Ｓ ピン部の外周面
Ｘ クランクシャフトの中心軸
Ｙ ピン部の中心軸[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction quenching and tempering apparatus for quenching and then tempering the outer peripheral surface of a journal portion or a pin portion of a crankshaft.
[0002]
[Prior art]
FIG. 4 shows a crankshaft 1 for a four-cylinder engine. The crankshaft 1 has journal parts 2a, 2b, 2c, 2d, centered on a central axis X (same as the axis of the journal part). 2e, pin portions 3a, 3b, 3c, 3d that are eccentric with respect to the central axis X, counterweight portions 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, and flange portion 5 It is formed integrally by forging. In the case of a crankshaft for a multiple cylinder engine, a plurality of pin portions 3 are provided. In the case of the crankshaft 1 for a four cylinder engine shown in FIG. 4, four pin portions 3a to 3d are provided. And these pin parts 3a-3d are each arrange | positioned between the counterweight parts 4 which adjoin each other in the location spaced apart by predetermined intervals along the axial direction of the central axis X. Further, the pin portions 3a to 3d that are adjacent to each other in the axial direction of the central axis X are disposed at angular positions that differ by a predetermined phase angle around the central axis X according to the type of the engine. In the case of the crankshaft 1 for a four-cylinder engine shown in FIG. 4, the pin portions 3a, 3d (center axis Y 1 Are disposed at locations having the same phase angle, and pin portions 3b and 3c (center axis Y) between these pin portions 3a and 3d. 2 The pin portions 3a, 3d on the left and right ends and the pin portions 3b, 3c at the intermediate positions are disposed at a phase angle of 180 degrees with respect to each other.
[0003]
In this type of crankshaft 1, conventionally, the outer peripheral surfaces of the journal portions 2a to 2e and the pin portions 3a to 3d of the crankshaft 1 are subjected to quenching treatment and tempering treatment by high frequency induction heating, respectively. The wear resistance and fatigue strength are improved. Here, the case where the pin portions 3a to 3d of the crankshaft 1 (hereinafter collectively referred to as the pin portion 3) are subjected to high-frequency induction heating will be described as an example.
[0004]
FIG. 5 shows an induction hardening and tempering apparatus 8 conventionally used for induction heating of the outer peripheral surface S of the pin portion 3 during the hardening and tempering processes. As shown in FIG. 5, the induction hardening device 8 is held in a state of being sandwiched between a pair of side plates 10 a and 10 b made of brass or resin, and is driven to rotate around the central axis X of the crankshaft 1. A semi-open saddle type high frequency induction heating coil (semi-open saddle type coil) 11 disposed opposite to the upper half portion of the outer peripheral surface S of the pin portion 3 to be applied, and a high frequency for supplying a high frequency current to the high frequency induction heating coil 11 A power source 12 and, for example, three ceramic or cemented carbide guide members (chip members) 13a, 13b, and 13c fixed to the pair of side plates 10a and 10 are provided.
[0005]
As shown in FIGS. 5 and 6, the high-frequency induction heating coil 11 described above includes a pair of left and right first and second heating coil portions 14a and 14b constituting a coil head, and a pair of these heating coil portions 14a. , 14b are connected to each other, and connection lead portions 16a, 16b connected to the pair of connection conductor portions 15a, 15b, respectively. Here, the first heating coil portion 14a of the high frequency induction heating coil 11 will be described in detail. As shown in FIG. 6, the first heating coil portion 14a is a pair of arc-shaped heating conductor portions 17a parallel to each other. , 18a, one end of the arc-shaped heating conductor portion 17a and one end of the arc-shaped heating conductor portion 18a, and the other end of the arc-shaped heating conductor portions 17a, 18a and the connecting conductor portion 15a. , 15c and linear heating conductors 20a, 21a respectively connecting one end of each of them, and having a generally rectangular shape that is curved as a whole. The second heating coil portion 14b is also configured in the same manner as the first heating coil portion 14a described above, and the pair of heating coil portions 14a and 14b are arranged correspondingly with a symmetrical arrangement relationship. In FIG. 6, a pair of arc-shaped heating conductor portions 17b and 18b, a linear heating conductor portion 19b, connection conductor portions 15a and 15c, and a feed lead portion 16b of the second heating coil portion 14b are illustrated. However, the linear heating conductor portions 20b and 21b corresponding to the linear heating conductor portions 20a and 21a described above are not illustrated because they are in a hidden position.
[0006]
The power supply lead portions 16a and 16b are connected to a high-frequency power source 12 via a high-frequency current supply transformer (not shown), and a predetermined high-frequency current is supplied from the high-frequency power source 12 to the high-frequency induction heating coil 11. It is configured to be.
[0007]
When high frequency induction heating of the outer peripheral surface S of the pin portion 3 of the crankshaft 1 is performed for quenching or tempering by the induction hardening and tempering apparatus 8 described above, induction hardening and tempering is performed by an elevating mechanism (not shown). By moving the device 8 downward from a predetermined standby position and placing it on the outer peripheral surface S of the pin portion 3 via the guide member 13b, the guide members 13a to 13c are brought into contact with the outer peripheral surface S of the pin portion 3. The high-frequency induction heating coil 11 is disposed opposite to the upper half portion of the outer peripheral surface S of the pin portion 3 with a slight gap. Under this state, when the crankshaft 1 is rotationally driven around the central axis X of the crankshaft 1 by a rotational drive mechanism (not shown), the pin portion 3 revolves around the central axis X accordingly. At this time, the induction hardening and tempering device 8 follows the pin portion 3 by a follow-up mechanism (not shown), and the first and second heating coil portions 14a and 14b of the high frequency induction heating coil 11 are located at the left and right symmetrical positions. 3 is always kept facing the upper half of the outer peripheral surface S.
[0008]
Under such a state, the first and second heating coil portions of the high-frequency induction heating coil 11 are sequentially passed from the high-frequency power source 12 through a transformer (not shown), power supply lead portions 16a and 16b, and connecting conductor portions 15a and 15b. A high frequency current is supplied to 14a and 14b, and the outer peripheral surface S of the pin part 3 is induction-heated by this. Next, when the outer peripheral surface S of the pin portion 3 is induction-heated to a required quenching temperature, the supply of the high-frequency current from the high-frequency power source 12 to the high-frequency induction heating coil 11 is interrupted, and the outer peripheral surface S of the pin portion 3 is stopped. The quenching cooling water is jetted by quenching cooling water jetting means (not shown). Thereby, the outer peripheral surface S of the pin part 3 is rapidly cooled, and a quenching process or a tempering process is performed.
[0009]
FIG. 7 shows a conventional induction hardening and tempering apparatus 31 including a semi-open saddle type high frequency induction heating coil (half open saddle type coil) 30 having another shape. As shown in FIG. 7, the induction hardening and tempering device 31 is held between a pair of side plates 10 a and 10 b made of brass or resin, and rotates around the central axis X of the crankshaft 1. A high frequency induction heating coil 30 having one heating coil portion 29 arranged to face the upper half portion of the outer peripheral surface S of the driven pin portion 3 (pin portions 3a to 3d) is provided. Other configurations are the same as those of the induction hardening and tempering apparatus 8 of FIG.
[0010]
As shown in FIGS. 7 and 8, the high-frequency induction heating coil 30 includes one heating coil portion 29 constituting a coil head) and a pair of power supply lead portions 32 a connected to the heating coil portion 29. 32b, and the power feed leads 32a and 32b described above are connected to the high frequency power supply 12. Here, the configuration of the heating coil portion 29 of the high frequency induction heating coil 30 will be described in detail. As shown in FIG. 8, the heating coil portion 29 includes a pair of arc-shaped heating conductor portions 33a and 33b parallel to each other, A linear heating conductor 34 that connects one end of the arc-shaped heating conductor 33a and one end of the arc-shaped heating conductor 33b, the other end of the arcuate conductors 33a and 33b, and one end of the power feed leads 32a and 32b Are respectively formed of linear heating conductor portions 35a and 35b.
[0011]
The power feed leads 32 a and 32 b are connected to a high frequency power supply 12 via a high frequency current supply transformer (not shown), and a predetermined high frequency current is heated from the high frequency power supply 12 to the high frequency induction heating coil 30. The coil portion 29 is configured to be supplied.
[0012]
The induction hardening and tempering device 31 described above is particularly effective for induction heating of a small crankshaft having a small diameter of the pin portion 3 or the journal portion 2. The reason for this is as follows. That is, in the induction hardening and tempering apparatus 8 of FIG. 5, the head of the high frequency induction heating coil 11 is divided into two heating coil portions 14a and 14b, and the arc-shaped heating conductor portions 17a and 17b are divided. When the diameter of the pin portions 3a to 3d or the journal portions 2a to 2e is small because the arc-shaped heating conductor portions 18a and 18b are divided into two in the circumferential direction and divided into two in the circumferential direction. Although the arc lengths of the arc-shaped heating conductor portions 15a, 15b and 16a, 16b are relatively short and the heating efficiency is deteriorated, in the induction hardening and tempering apparatus 31 of FIG. Since the arc-shaped heating conductor portions 33a and 33b of the coil portion 29 are not divided into two, the arc-shaped heating conductor portions 33a and 33b facing the outer peripheral surface S of the pin portion 3 (or the outer peripheral surface H of the journal portion 2). Arc length Relatively longer than the above case, because the heating efficiency is improved due to this.
[0013]
The induction hardening and tempering process of the pin portion 3 of the crankshaft 1 by the induction hardening and tempering apparatus 31 of FIG. Since it is the same as the process by, the description is abbreviate | omitted.
[0014]
Further, since the induction hardening or induction tempering process described above is the same for the outer peripheral surface H of the journal portion 2, the description thereof is omitted.
[0015]
FIGS. 9A to 9C are typical examples of the cross-sectional shape of the high-frequency induction heating coil 11 or 30, and are desirably obtained on the outer peripheral surface S of the pin portion 3 by the quenching process as described above (ideal N) Hardened layer pattern P 1 , P 2 , P Three Respectively. As shown in FIG. 9A, the hardened and hardened layer pattern P is formed only on the outer peripheral surface (cylindrical outer peripheral surface) S of the pin portion 3. 1 9 is called flat quenching, and a hardened and hardened layer pattern P connected from the outer peripheral surface S of the pin portion 3 to the R portions (arc-shaped corner portions) M on both sides thereof as shown in FIG. 9B. 2 The quench hardening layer pattern is referred to as fillet R quenching, and is a hardened hardened layer pattern continuous from the outer peripheral surface S of the pin portion 3 to the R portion M and the thrust portion (planar portion) N on one side as shown in FIG. P Three The quenching that forms is usually referred to as piece R quenching. The piece R quenching in FIG. 9C is performed on the first journal portion 2a or the fifth journal portion 2e in the journal portions located at both ends of the crankshaft 1, for example, in the crankshaft 1 for a four-cylinder engine shown in FIG. Often done.
[0016]
Next, the crankshaft 1 subjected to the quenching process according to the above-described procedure is subjected to tempering for tempering after the quenching process. As the tempering heating method, a method using an electric furnace, A method using high-circumferential induction heating is generally practiced.
[0017]
In the case of tempering with an electric furnace, the temperature inside the furnace is first raised to the tempering temperature, and all the journal parts 2 and all the pin parts 3 are quenched in the electric furnace after the temperature raising is completed. A plurality of the crankshafts 1 are put together according to the size of the electric furnace, and after raising the temperature of the crankshaft to the furnace temperature, the required time (usually about 1.0 to 2.5 hours) After holding and heating, it is taken out from the electric furnace and the tempering process is completed.
[0018]
Heating by the electric furnace is due to heat conduction from the atmosphere in the furnace, so there is no temperature variation in one crankshaft 1 and therefore tempering hardness variation occurs in the tempering process. There is no.
[0019]
Moreover, as a tempering method by induction heating, there is a method of tempering using the induction quenching and tempering apparatus 8 or 31 for quenching described above, and in the case of the tempering method, induction hardening is performed. The structure of the induction hardening and tempering device 8 is again applied to the outer peripheral surface S of the pin portion 3 of the crankshaft 1 or the outer peripheral surface H of the journal portion 2 of the crankshaft 1 that has been subjected to the quenching process using the tempering device 8 or 31. The high frequency induction heating coil 11 which is an element or the high frequency induction heating coil 30 which is a component of the induction hardening and tempering device 3 is supplied with a high frequency current from a high frequency power source 12 over a required time to perform high frequency induction heating and thereby the pin portion 3. Alternatively, a tempering process is performed for each journal portion 2. However, this tempering method is effective only for flat tempering as shown in FIG. 10 (a), and fillet R quenching as shown in FIG. 10 (b) or FIG. 10 (c). It cannot be applied to the piece R quenching as shown. The reason for this is that in the conventional tempering process using a high frequency induction heating coil for quenching, it is difficult to sufficiently induction heat the R part M when the radius of the R part M is small. This is because the temperature of the R part M first increases when the temperature is large, and in any case, the continuous region including the R part M cannot be heated uniformly during tempering.
[0020]
FIG. 11 shows another tempering device 37 using high-frequency induction heating, and this tempering device 37 is proposed by Japanese Patent Laid-Open No. 2001-303134 (Patent Document 1). The above-described tempering device 37 uses the induction hardening and tempering device 8 or 31 to inductively quench the crankshaft 1 in which all the journal portions 2 and all the pin portions 3 have been subjected to the quenching process by the procedure described above. Arranged at a position completely surrounded by a substantially circular solenoid type high frequency induction heating coil 38 arranged at a position different from the quenching process, including the unweighted counterweight part 4 and the flange part 5 etc. Thus, the entire crankshaft 1 is tempered by performing high-frequency induction heating collectively to the required tempering temperature.
[0021]
According to such a tempering device 37, it is possible to achieve a sufficient tempering effect regardless of flat quenching or fillet R quenching, and the temperature is increased as compared with the tempering method using the electric furnace described above. Since the warm time and holding (soaking) time are short (about 60 seconds to 200 seconds in total), the degree of removal of the compressive residual stress of the hardened part related to fatigue strength can be suppressed to a sufficient level. It is possible to maintain a high compressive residual stress. And since heating time is short, the installation of the equipment which performs the process of quenching to tempering sequentially is possible.
[0022]
[Patent Document 1]
JP 2001-303134 A
[0023]
[Problems to be solved by the invention]
However, since heating by an electric furnace is heating by heat conduction from the atmosphere in the furnace, the heating time (total time of temperature rising time and holding time) is much longer than that in the case of high frequency induction heating, so it is inlined. It is difficult. In addition, when trying to increase the amount of processing once, there is a problem that the volume of the electric furnace has to be increased, and the installation area of the facility increases. Furthermore, due to the long-time heating as described above, the compressive residual stress generated in the outer peripheral surfaces H and S of the journal portion 2 and the pin portion 3 which are the quenching portions due to induction hardening is released and reduced. Therefore, there is a problem that the fatigue strength of the crankshaft 1 is lowered. And before tempering the crankshaft 1, the time and electric power for raising temperature in a furnace to tempering temperature are required, and the reality is that production efficiency and energy efficiency are low.
[0024]
The method of continuously performing induction quenching and induction tempering of the journal part 2 or the pin part 3 using the induction hardening tempering apparatus 8 or 31 for quenching is conventionally employed for flat quenching and flat tempering. (See FIG. 10A). In the case of flat quenching, as shown in FIG. 10 (a), the heating region α during quenching heating depends on the heating conditions and the degree of heat conduction during quenching and tempering. 1 , Α 2 Heating area α during tempering heating compared to the width of Three , Α Four When the induction tempering heating is performed in a short time using the half-opening saddle type heating coil 11 or 30 for quenching, the portion of the portion facing the half-opening saddle type heating coil 11 or 30 for quenching is used. The tempering effect appears only in a small area. This phenomenon does not change even when the high-frequency current value supplied to the quenching high-frequency induction heating coil 11 or 30 during tempering heating is increased, and the tempering heating region α is increased by the amount of increased high-frequency current value. Three , Α Four Only the area is overheated and excessively tempered, and the surface hardness of the area is excessively lowered. On the other hand, there is an area where the tempering effect hardly appears in the vicinity of the above-mentioned overtempered area. Will do. As a result, there arises a problem in heat treatment quality that the surface hardness of each part of the cured layer after the tempering process is not constant.
[0025]
The reason for this will be described as follows. First, the setting of the tempering temperature when the tempered crankshaft 1 is tempered is usually in the range of 150 ° C to 280 ° C. The penetration depth of the induced current flowing in the vicinity of the surface of the object to be heated in this temperature region is, for example, about 0.1 mm when the frequency is 20 KHz. On the other hand, the penetration depth in the quenching temperature region above the magnetic transformation point (about 760 ° C.) of steel that is the material of the crankshaft is about 3.5 mm in the case of 20 KHz, and the penetration depth in the tempering temperature region. Therefore, even when the same high frequency induction heating coil is used at the time of quenching and tempering, the size of the heating region is different. Incidentally, the depth of the hardened hardened layer formed on the journal portion and the pin portion of the crankshaft 1 is generally about 3.0 mm to 5.0 mm.
[0026]
Therefore, when induction tempering is performed using the induction hardening apparatus 8 or 31 for quenching, it is difficult to solve the above-described problems in heat treatment quality if heating is performed for a short time. In order to solve the heat treatment quality problem and obtain a sufficient tempering effect, in addition to the induction heating time, a sufficient time for heat conduction (cooling time) is provided, and the current penetration depth is very small. The heat generated by induction heating of a narrow region with respect to the hardened hardened layer must be heated inside the hardened layer at a penetration depth or more by heat conduction, but the time required for the tempering process Due to the lengthening, there is a problem that the total heat treatment time of the crankshaft 1 is lengthened and productivity is lowered.
[0027]
Moreover, induction tempering by the induction hardening coil body of the journal part 2 or the pin part 3 in which the hardened hardened layer region has a wider fillet R hardened hardened layer than flat hardened is required for the tempering for the reasons described above. In addition to the longer time, there is a problem in that a temperature difference is more likely to occur than when a quench-hardened layer of flat quenching is tempered, and thus the hardness variation after tempering increases.
[0028]
In addition, as another tempering method by high frequency induction heating, the crankshaft 1 in which all the journal portions 2 and all the pin portions 3 are quenched, including the non-quenched region including the counterweight portion 4, There is a method in which the crankshaft 1 is completely surrounded by the above-described substantially circular solenoid type high-frequency induction heating coil 38 (see FIG. 11), and the crankshaft 1 is subjected to high-frequency induction heating collectively to perform tempering. When the size of the crankshaft 1 becomes larger, for example, a crankshaft (2.0 m or more) for a construction machine or a ship, the solenoid type high frequency induction heating coil 38 becomes correspondingly large. As a result, the tempering device There is a problem that the overall size of the system becomes large and the installation area of the equipment increases.
[0029]
The present invention has been made in view of the above points, and an object of the present invention is to eliminate various problems as described above, and to obtain a sufficient tempering effect in a short time, and a compact crankshaft. It is to provide an induction tempering apparatus and an induction tempering coil body used in the apparatus.
[0030]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in the induction hardening and tempering apparatus for performing induction hardening and induction tempering on the outer peripheral surface of the journal part or the pin part of the crankshaft, half-opening for quenching An induction hardening coil body having a saddle type high frequency induction heating coil and an induction hardening coil body having a semi-open saddle type high frequency induction heating coil for tempering, respectively, and sandwiching the central axis of the journal part or pin part 2 Surrounding substantially the entire circumference of the outer peripheral surface of the journal part or the pin part by the half-open vertical type high frequency induction heating coil for quenching and the half open vertical type high frequency induction heating coil for tempering moved from the direction, The quenching semi-open saddle type high frequency induction heating coil and the tempering half open saddle type high frequency induction heating coil are arranged opposite to the outer peripheral surface of the pin part or the journal part. The high frequency is applied to the outer peripheral surface of the journal portion that rotates as the rank shaft rotates about the central axis, or the outer peripheral surface of the pin portion that performs the revolving motion around the central axis of the crankshaft. Induction hardening is performed while following the quenched coil body, and then induction tempering is performed while following the outer peripheral surface of the journal portion or the pin portion.
In the present invention, the induction-hardened coil body and the induction-tempered coil body are connected to a common high-frequency power source via a switching device that switches a high-frequency current path, and the switching device is used in an induction hardening process. A high frequency current is supplied to the half-open vertical type induction induction coil for induction hardening of the induction hardening coil body. In the induction tempering step, the induction device is used for tempering the induction tempering coil body. A high frequency current is supplied to the half-open saddle type high frequency induction heating coil.
In the present invention, the induction-hardened coil body and the induction-tempered coil body are connected to different high-frequency power sources, respectively, and a high-frequency induction coil is used as a high-frequency induction coil for quenching the induction-hardened coil body. The high-frequency current can be supplied also to the semi-open saddle type high-frequency induction heating coil for tempering the high-frequency tempered coil body during the period of supplying the current.
In the present invention, the induction hardening and quenching for performing induction tempering treatment on the journal portion or the pin portion of the crankshaft subjected to flat quenching by the induction hardening and tempering device for a crankshaft as described above. In the induction tempering coil body constituting the tempering apparatus, the tempering half-open vertical type induction heating coil constituting the induction tempering coil body is a quenching half-open vertical type high frequency induction heating coil. Compared to the induction heating coil, the width in the direction along the center axis of the crankshaft is wide, and the distance between the journal part or the outer peripheral surface of the pin part is the semi-opening saddle type high frequency induction for quenching. The distance is set larger than the distance between the heating coil and the outer peripheral surface of the journal part or the pin part.
In the present invention, the above-described induction tempering treatment is performed on the journal portion or the pin portion of the crankshaft subjected to fillet R quenching by the induction hardening and tempering device for the crankshaft having the above-described configuration. In the induction tempering coil body constituting the induction hardening and tempering apparatus, the tempering semi-open vertical type induction heating coil constituting the induction tempering coil body is a quenching half constituting the induction hardening coil body. Compared with the open saddle type high frequency induction heating coil, the distance between the outer peripheral surface of the journal part or the pin part is more than the distance between the semi-open saddle type high frequency induction heating coil for quenching and the outer peripheral surface. And the distance between the part that rises perpendicularly to the journal part or the pin part including the R part that continues from the outer peripheral surface of the journal part or the pin part is half-open for quenching It is configured to be set larger than the distance between the mold high-frequency induction heating coil and the distance between the sites.
Moreover, in the present invention, the induction tempering process is performed on the journal portion positioned at the end of the crankshaft, which has been subjected to the piece R quenching by the induction hardening and tempering device for the crankshaft having the above-described configuration. In the induction tempering coil body constituting the induction hardening and tempering apparatus, the tempering half-open vertical induction heating coil constituting the induction tempering coil body is a tempering coil constituting the induction hardening coil body. Compared with the half-open saddle type high frequency induction heating coil for insertion, the distance between the outer peripheral surface of the journal part is the distance between the half open saddle type high frequency induction heating coil for quenching and the outer peripheral surface. The distance between the portion that rises perpendicularly to the journal portion or the pin portion including the R portion that is continuous from the outer peripheral surface of the journal portion is larger than the distance between Mold Along the central axis of the crankshaft of the heating conductor portion that is larger than the distance between the conductive heating coil and the portion and that faces only the outer peripheral surface of the semi-opening saddle type high frequency induction heating coil for tempering The width in the direction is set to be larger than the width in the direction along the central axis of the crankshaft of the heating conductor portion facing only the outer peripheral surface of the semi-opening saddle type high frequency induction heating coil for quenching is doing.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS. 1 to 3, the same parts as those in FIGS. 4 to 11 are denoted by the same reference numerals, and redundant description is omitted.
[0032]
FIG. 1 shows an induction hardening and tempering apparatus 40 according to an embodiment of the present invention. The induction hardening and tempering apparatus 40 is a half-open vertical type induction heating coil 30a for quenching (hereinafter referred to as the induction hardening coil 30a). The induction hardening coil body J having a quenching heating coil 30a) and a tempering semi-open saddle type high frequency induction heating coil 30b (hereinafter referred to as a tempering heating coil 30b). And an induction tempering coil body K. That is, the apparatus 40 includes a quenching heating coil 30a as a high-frequency quenching coil body J held between a pair of side plates 41a and 41b made of brass or resin, and a pair of brass or resin. Tempering heating coil 30b as induction tempering coil body K held between the side plates 42a and 42b.
[0033]
The above-described quenching heating coil 30a and tempering heating coil 30b are each a coil body configured similarly to the high-frequency induction heating coil 30 of FIG. 8, that is, a heating coil configured similar to the high-frequency induction heating coil 30. The coil body has a portion 29 and is configured in the same shape.
[0034]
Further, the quenching heating coil 30a and the tempering heating coil 30b having the same shape are arranged in opposite directions at the left and right positions, and are moved from the left and right directions sandwiching the central axis Y of the pin portion 3. Are arranged so as to face each other. In this case, since it is necessary to arrange the quenching heating coil 30a and the tempering heating coil 30b so as not to contact each other, both ends of the quenching heating coil 30a and the tempering heating coil 30b as shown in FIG. A slight gap is provided between both end portions of the pin portion 3, and the quenching heating coil 30 a and the tempering heating coil 30 b provide almost the entire circumference of the outer peripheral surface of the pin portion 3 (not the complete circumference but the pin portion 3. Most of the outer peripheral surface of the outer periphery of the outer periphery of the outer periphery of the outer periphery of the outer periphery. Thus, the heating coil portion 29 of the quenching heating coil 30a comprising the pair of arc-shaped heating conductor portions 33a and 33b, the linear heating conductor portion 34, and the pair of linear heating conductor portions 35a and 35b is replaced with a crankshaft. 1 is configured to be opposed to one half of the side surface of the outer peripheral surface S of the pin portion 3 of the crankshaft 1 that is driven to rotate about the central axis X of the crankshaft 1 and heats the heating coil 30b for tempering. The coil portion 29 is arranged to face the other half of the side surface of the outer peripheral surface S of the pin portion 3 of the crankshaft 1 that is driven to rotate about the central axis X of the crankshaft 1.
[0035]
As shown in FIG. 1, the power supply leads 32a and 32b of the first high-frequency induction heating coil 30a are connected to first and second high-frequency current supply transformers (not shown), respectively. Is connected to a high frequency power source 12 via a switch 50 for switching a high frequency current path. Therefore, a predetermined high-frequency current is alternatively supplied from the single high-frequency power source 12 to the quenching heating coil 30a and the tempering heating coil 30b via the switch 50 and a transformer (not shown). It is comprised so that. That is, the high-frequency current is selectively supplied to only one of the quenching heating coil 30a and the tempering heating coil 30b.
[0036]
Further, between the pair of side plates 41a and 41b to which the quenching heating coil 30a is attached, a pair of guide members 43a and 43b are attached at locations corresponding to the quenching heating coil 30a. Between the pair of side plates 42a, 42b to which the heating coil 30b is attached, a pair of guide members 44a, 44b are attached at locations corresponding to the tempering heating coil 30b. Thus, the two quenching heating coils 30a and the tempering heating coils 30b are arranged on the left and right sides of the center axis Y of the pin portion 3 to be heated via the guide members 43a, 43b and 44a, 44b. The outer circumferential surface S of the pin portion 3 is opposed to the outer circumferential surface S of the pin portion 3 with a slight gap from the two directions, and the outer circumferential surface S of the pin portion 3 is almost entirely surrounded by the quenching heating coil 30a and the tempering heating. It is comprised so that it may be in the state surrounded by the heating coil part 29 of the coil 30b.
[0037]
2 (a), 2 (b) and 2 (c) show the AA cross section in FIG. 1 of the induction hardening and tempering device 40 described above, and FIG. Sectional drawing of the heating coil 30a for flat quenching and the heating coil 30b for flat tempering as an induction hardening and tempering device for flat quenching and flat tempering of the outer peripheral surface S of the part 3, FIG. The high frequency provided with the fillet R quenching heating coil 30a and the fillet R quenching heating coil 30b as an induction quenching and tempering device for the fillet R quenching and fillet R tempering of the outer peripheral surface S of the pin portion 3 2C is a cross-sectional view of the quenching and tempering device 40. FIG. 2C shows the outer peripheral surface H of the first journal portion 2a (or the fifth journal portion 2e) positioned at the end portion of the crankshaft 1 as a piece R quenching and a piece. Heating coil 30a for piece R quenching as an induction hardening tempering device for R tempering It is a cross-sectional view of a beauty piece R tempering heating coil 30b.
[0038]
2A, 2B, and 2C, the outer peripheral surfaces of the arc-shaped heating conductor portions 33a, 33b and the pin portion 3 of the heating coil 30a for quenching during the quenching process and the tempering process. S or the distance L between the outer peripheral surface H of the journal part 2 1 And the distance L between the arc-shaped heating conductor portions 33a, 33b of the tempering heating coil 30b and the outer peripheral surface S of the pin portion 3 or the outer peripheral surface H of the journal portion 2. 2 The relationship with L 1 <L 2 It is set to become. Further, in the case of FIGS. 2A and 2C, a pair of circles of the heating coil 30a for quenching of the induction quenching and tempering apparatus 40 for flat quenching, fillet R quenching, or piece R quenching is used. The distance d between the arc-shaped heating conductor portions 33a and 33b and the thrust portion N of the pin portion 3 (side surface as a portion rising vertically from the cylindrical outer peripheral surface) 1 And the distance d between the pair of arc-shaped heating conductor portions 33a and 33b of the tempering heating coil 30b and the thrust portion N of the pin portion 3 2 Respectively, d 1 <D 2 Is set to be a relationship.
[0039]
Further, the width W of the arc-shaped heating conductor portion 33a of the tempering heating coil 30b installed in the induction hardening and tempering device 40 for flat quenching and flat tempering shown in FIGS. 2 (a) and 2 (c), respectively. 2 Is the width W of the arc-shaped heating conductor portion 33a of the heating coil 30a for quenching. 1 And wider than (W 1 <W 2 ), Thereby performing tempering heating with the heating coil 30a for quenching (heating region α) 1 And α 2 ) Than heating area α Three And α Four Is configured to be wide. In FIG. 2C, the arc-shaped heating conductor portion 33a of the quenching heating coil 30a and the tempering heating coil 30b is a heating conductor portion (R portion) facing only the outer peripheral surface H of the journal portion 2a. M and the heating conductor portion not facing the thrust portion N).
[0040]
When performing the quenching process and the subsequent tempering process, the two quenching heating coils 30a and 30b are arranged on the outer peripheral surface S or the journal part of the pin portion 3 in the arrangement relationship as described above. 2a, the crankshaft 1 is rotationally driven around its center line X by a rotational drive mechanism (not shown) under the state of being opposed to the outer peripheral surface H of the figure 2a. The two quenching heating coils 30a and the tempering heating coil 30b are caused to follow the pin portion 3 that rotates or the journal portion 2a that rotates about the central axis X by a tracking mechanism that is not shown. At this time, the quenching heating coil 30a and the tempering heating coil 30b of the table are always arranged to face each other at a predetermined interval on the outer half surface S of the pin portion 3 or the side half portion of the outer circumference surface H of the journal portion 2a. The maintained state is maintained.
[0041]
Under such a state, the switching device 50 is first switched from the off state to the first on state, whereby the high frequency current is supplied only from the high frequency power supply 12 to the quenching heating coil 30a via the first transformer (not shown). In response to this, the outer peripheral surface S of the pin portion 3 or the outer peripheral surface H of the journal portion 2a is subjected to high frequency induction heating. Next, when the outer peripheral surface S or H is induction-heated to a required quenching temperature, the high-frequency current from the high-frequency power source 12 to the quenching heating coil 30a is switched by switching the switch 50 to the original off state. The supply is shut off, and the quenching coolant is sprayed to the outer peripheral surface S or H heated to the required quenching temperature by quenching coolant injection means (not shown). Thereby, the said outer peripheral surface S or H is rapidly cooled, and a hardening hardening layer is formed.
[0042]
A tempering process is performed following such a quenching process. At this time, by switching the switch 50 from the off state to the second on state, a high frequency current is supplied from the high frequency power source 12 only to the tempering heating coil 30b via the second transformer (not shown), In response to this, the outer peripheral surface S of the pin portion 3 or the outer peripheral surface H of the journal portion 2a is heated by high frequency induction. Next, when the outer peripheral surface S or H is induction-heated to a required tempering temperature, the switching device 50 is switched to the original OFF state, whereby the high-frequency current from the high-frequency power source 12 to the tempering heating coil 30b is changed. The supply is shut off, and the quenching coolant is sprayed to the outer peripheral surface S or H heated to the required quenching temperature by quenching coolant injection means (not shown). Thereby, the said outer peripheral surface S or H is cooled to normal temperature, and a tempering process is completed.
[0043]
In addition, the energization switching from the heating coil 30a for quenching to the heating coil 30b for tempering by the switch 50 may be performed during quenching and cooling after the heating in the quenching process. It is possible to shorten the heat treatment time.
[0044]
According to the induction hardening and tempering apparatus 40 as described above, the following operational effects can be achieved. That is, in the induction hardening and tempering apparatus 40 for flat quenching shown in FIG. 2A, the width W of the arc-shaped heating conductor portions 33a and 33b of the heating coil 30b for tempering. 2 Is made wider than the width of the arc-shaped heating conductors 33a and 33b of the quenching heating coil 30a (the width W of the tempering heating coil 30b). 2 The width W of the heating coil 30a for quenching 1 Against W 2 > W 1 Therefore, when tempering heating is performed with the heating coil 30a for quenching (heating region α) 1 , Α 2 ), The heating regions α3 and α4 during tempering heating become wider. Further, the distance L between the two arc-shaped heating conductor portions 33a and 33b of the tempering heating coil 30b and the outer peripheral surface S of the pin portion 3. 2 , The distance L between the two arcuate heating conductor portions 33a, 33b of the quenching heating coil 30a and the outer peripheral surface S of the pin portion 3. 1 (L 2 > L 1 ) By tempering the outer peripheral surface S of the pin portion 3 with heat conduction to the inside at a position where the magnetic flux density is low compared with the heating by the quenching heating coil 30a. The outer peripheral surface S or H and the peripheral portion thereof can be heated uniformly, and the heat transfer to the quench hardened layer can be uniformly performed, so that the hardness variation after tempering treatment can be achieved. Can be suppressed.
[0045]
Further, in the induction hardening and tempering apparatus 40 for fillet R quenching shown in FIG. 2 > L 1 And a distance d between the pair of arc-shaped heating conductor portions 33a and 33b of the tempering heating coil 30b and the thrust portion N of the pin portion 3 2 The distance d between the pair of arc-shaped heating conductor portions 33a, 33b of the quenching heating coil 30a and the thrust portion N of the pin portion 3 1 Is set larger than (d 2 > D 1 ) Since the tempering heating coil 30b is located farther from the pin portion 3 than the coil 30a, the magnetic flux density as compared with the heating by the quenching heating coil 30a as in the case of the flat quenching described above. Will be heated at a low position, heating castle α at the time of quenching 1 , Α 2 Heating area α during tempering compared to Three , Α Four Becomes wider. Accordingly, the outer peripheral surface S of the pin portion 3 is tempered and heated at a moderate temperature increase rate while conducting heat conduction to the inside, so that the outer peripheral surface S and the peripheral portion thereof are uniformly heated. Thus, heat transfer to the inside of the quench-hardened layer can be performed uniformly, and hence it is possible to suppress variation in hardness after tempering.
[0046]
In addition, in the induction quenching and tempering apparatus 40 for fillet R quenching shown in FIG. 2 (c), the first journal portion is the same as in the case of the flat quenching and the fillet R quenching tempering described above. The positional relationship between the heating coil 30a for quenching and the heating coil 30b for tempering in the vicinity of the outer peripheral surface H and R part M of 2a is such that the tempering heating coil 30b is more for the outer peripheral surface H than the quenching heating coil 30a. Since the heating is performed at a position where the magnetic flux density is low, the heating region α during quenching is α. 1 , Α 2 Heating area α during tempering compared to Three , Α Four Becomes wider. As a result, the outer peripheral surface H of the first journal part 2a (or the fifth journal part 2e) is tempered and heated at a moderate temperature increase rate with heat conduction to the inside. It is possible to raise the temperature of the outer peripheral surface H and its peripheral portion evenly, and to uniformly transfer the heat to the inside of the hardened and hardened layer, and thus it is possible to suppress the variation in hardness after tempering. It becomes.
[0047]
FIG. 3 shows an induction hardening and tempering apparatus 40 ′ according to another embodiment of the present invention. The structure of the apparatus 40 ′ is exactly the same as that shown in FIG. A first high-frequency power source 12a is connected to the heating coil 30a, and a second high-frequency power source 12b is connected to the tempering heating coil body 30b. The oscillation frequencies of the first and second high frequency power supplies 12a and 12b may be the same.
[0048]
By configuring as described above, a high-frequency current can be simultaneously supplied to the quenching heating coil 30a and the tempering heating coil 30b. There is an effect.
(1) At the time of induction hardening, a high frequency current is supplied from the first high frequency power supply 12a to the quenching heating coil 30a, and at the same time, a high frequency current is supplied from the second high frequency power supply 12b to the tempering heating coil 30b. If the heating and heating are performed, the effect of preheating the entire heated region by the tempering heating coil 30b can be obtained. Therefore, particularly when the large crankshaft 1 is quenched, the heating time is reduced. It can be shortened. Moreover, unlike the conventional induction hardening apparatus which heats only the outer peripheral surface H or S of the outer peripheral surface H or S of the journal part 2 or the pin part 3, two heating coils for hardening are provided on almost the entire periphery. Since it is surrounded by 30a and the tempering heating coil 30b for high-frequency induction heating, the time until soaking can be shortened, so that the bending of the crankshaft 1 after quenching can be kept small.
(2) In the induction tempering step after the induction hardening is completed, a high-frequency current is supplied to the tempering heating coil 30b, and at the same time, a high-frequency current is supplied to the tempering heating coil 30a to perform tempering heating. In this case, the tempering heating time can be shortened as in the case of quenching.
[0049]
In addition, according to the induction hardening and tempering apparatus 40 and 40 'described above, it is only necessary to provide two heating coils 30a and 30b for tempering. It is not necessary to provide the return high-frequency induction heating coil 38, and the entire apparatus can be made compact.
[0050]
The embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, in the two embodiments described above, as the heating coil 30a for quenching and the heating coil 30b for tempering, those having a structure equivalent to the high frequency induction heating coil 30 constituting the conventional induction hardening and tempering device 31 are used. Although used, it can be replaced with a high-frequency induction heating coil 11 constituting the conventional induction hardening and tempering device 8. Furthermore, in the induction hardening and tempering apparatus 40 ', the high frequency power supply 12b connected to the tempering heating coil 30b is compared with the oscillation frequency of the high frequency power supply 12a connected to the high frequency heating coil 30a for hardening. The oscillation frequency may be lowered.
[0051]
【The invention's effect】
The present invention described in claim 1 includes an induction hardening coil body having a semi-open saddle type high frequency induction heating coil for quenching and an induction tempering coil body having a half open saddle type high frequency induction heating coil for tempering. Each of the journal portions includes a quenching semi-open saddle type high frequency induction heating coil and a tempering half open saddle type high frequency induction heating coil that are respectively provided and moved from two directions sandwiching the central axis of the journal portion or pin portion of the crankshaft Alternatively, since induction hardening is performed after induction hardening is performed around the entire circumference of the outer peripheral surface of the pin portion, induction hardening and induction tempering can be performed with a single device. There is no need to provide an induction tempering apparatus separately from the quenching apparatus, and therefore the apparatus (equipment) can be made compact and inexpensive, and the installation area of the apparatus can be reduced. And since tempering heating is performed by the high frequency induction heating coil only for tempering, sufficient tempering quality can be obtained in a short time, and productivity can be improved.
[0052]
According to the second aspect of the present invention, the induction hardening coil body and the induction tempering coil body are respectively connected to a common high frequency power source via a switching device, so that the half-open vertical induction induction heating for induction hardening is performed. Since the high-frequency current is selectively supplied to the coil and the tempering semi-open saddle type high-frequency induction heating coil, only one high-frequency power source is required, and the apparatus can be made inexpensive.
[0053]
According to the third aspect of the present invention, the induction-hardened coil body and the induction-tempered coil body are connected to different high-frequency power sources, and the induction-hardened coil body is half-opened saddle-type induction induction heating for quenching. Since the high-frequency current can be supplied also to the semi-open saddle type high-frequency induction heating coil for tempering the high-frequency tempered coil body during the period in which the high-frequency current is supplied to the coil, By performing quenching heating and tempering heating with a semi-open vertical type high frequency induction heating coil and a semi-open vertical type high frequency induction heating coil for tempering, it is possible to shorten the heat treatment time of the crankshaft and improve productivity. It becomes possible to improve.
[0054]
Further, the present invention described in claim 4 is an induction tempering coil body for performing induction tempering treatment on a journal part or a pin part of a crankshaft subjected to flat quenching. The tempering semi-open saddle type high frequency induction heating coil is smaller in width in the direction along the central axis of the crankshaft than the quenching half open saddle type high frequency induction heating coil constituting the induction hardening coil body. Wide and the distance between the outer peripheral surface of the journal part or the pin part is set to be larger than the distance between the semi-open saddle type high frequency induction heating coil for quenching and the outer peripheral surface of the journal part or the pin part. Thus, the outer peripheral surface of the journal part or the pin part can be induction-heated with high frequency induction at a moderate temperature increase rate while being accompanied by heat conduction to the inside of the heated part. Since the outer peripheral surface and the peripheral portion thereof are heated uniformly and heat transfer to the inside of the hardened and hardened layer is uniformly performed, it is possible to suppress variation in hardness after tempering treatment. Become.
[0055]
According to a fifth aspect of the present invention, there is provided an induction tempering coil body for performing induction tempering treatment on a journal portion or a pin portion of a crankshaft subjected to fillet R quenching. Compared with the half-open saddle type high frequency induction heating coil for quenching constituting the induction hardening coil body, the semi-open type saddle type high frequency induction heating coil for tempering is formed with the outer peripheral surface of the journal part or the pin part. The distance between them is larger than the distance between the quenching semi-open saddle type high frequency induction heating coil and the outer peripheral surface, and includes the R portion continuous from the outer peripheral surface of the journal portion or the pin portion. The distance between the part (thrust part) that rises perpendicular to the part is set to be larger than the distance between the half-open saddle type high frequency induction heating coil for quenching and the part. Configured Therefore, the outer peripheral surface of the journal part or the pin part can be subjected to high-frequency induction heating at a moderate temperature increase rate while being accompanied by heat conduction to the inside of the heated part. Since the peripheral portion is heated uniformly and the heat transfer to the inside of the quench hardened layer is performed uniformly, it is possible to suppress the variation in hardness after tempering, which is difficult in the past. The induction tempering process of the fillet R quenching portion that has been performed becomes possible. In addition, tempering by induction heating can be performed for each journal portion or pin portion using a semi-open saddle type high frequency induction heating coil without heating the entire crankshaft, so that a crank subjected to fillet R quenching is applied. Compared with the conventional apparatus for tempering the shaft, the apparatus becomes cheaper and the entire apparatus can be made smaller (compact).
[0056]
According to a sixth aspect of the present invention, there is provided an induction tempering coil body for performing induction tempering treatment on a journal portion or a pin portion of a crankshaft subjected to piece R quenching. The half-open vertical type induction heating coil for tempering that constitutes the distance between the outer peripheral surface of the journal part compared to the half-open vertical type induction induction coil for quenching that constitutes the induction hardening coil body Is larger than the distance between the half-open saddle type high frequency induction heating coil for quenching and the distance between the outer peripheral surface and includes an R portion continuous from the outer peripheral surface of the journal portion, or a journal portion or a pin portion. The distance between the part rising vertically with respect to the half open saddle type high frequency induction heating coil for quenching and the part is larger than the distance between the part and the half open saddle type high frequency induction heating coil for tempering. It faces only the outer peripheral surface The width in the direction along the center axis of the crankshaft of the heating conductor is such that the width along the center axis of the crankshaft of the heating conductor facing only the outer peripheral surface of the half-open saddle type high frequency induction heating coil for quenching. Since it is configured to be set to be larger than the width, the outer peripheral surface of the journal part or the pin part can be induction-heated at a moderate temperature increase rate while heat conduction to the inside of the heated part. Since the outer peripheral surface of the journal part or the pin part and the peripheral part thereof are heated uniformly, the heat transfer to the inside of the hardened and hardened layer is uniformly performed. Therefore, it is possible to perform induction tempering of the piece R quenching portion, which has been considered difficult in the past. In addition, tempering by induction heating can be performed for each journal portion or pin portion using a semi-open saddle type high frequency induction heating coil without heating the entire crankshaft, so that a crank subjected to fillet R quenching is applied. Compared with the conventional apparatus for tempering the shaft, the apparatus becomes cheaper and the entire apparatus can be made smaller (compact).
[Brief description of the drawings]
FIG. 1 is a side view of an induction hardening and tempering device for a crankshaft according to an embodiment of the present invention.
2 is an enlarged cross-sectional view taken along line AA of the induction hardening and tempering apparatus of FIG. 1, and FIG. FIG. 2B is a diagram showing a cross section of a heating coil for quenching and a tempering heating coil in the fillet R quenching, and a heating zone. FIG. 2C is a diagram for quenching in a piece R quenching. It is a figure which shows the cross section and heating area | region of a heating coil and the heating coil for tempering.
FIG. 3 is a side view of an induction hardening and tempering device for a crankshaft according to another embodiment of the present invention.
FIG. 4 is a perspective view of a crankshaft for a four-cylinder engine.
FIG. 5 is a side view of a conventional crankshaft high-frequency induction heating apparatus.
6 is a schematic perspective view of a high-frequency induction heating coil that is a component of the high-frequency induction heating device of FIG.
FIG. 7 is a side view of another conventional crankshaft high-frequency induction heating apparatus.
8 is a perspective view of another high-frequency induction heating coil that is a component of the high-frequency induction heating device of FIG. 7. FIG.
9A is a cross-sectional view showing a cross-sectional shape of a flat quenching heating coil and a flat tempering heating coil, and a preferable hardened and hardened layer formed on the pin portion, and FIG. 9B is a fillet. 9C is a cross-sectional view showing a cross-sectional shape of the heating coil for R quenching and the heating coil for fillet R quenching and a preferable hardened and hardened layer formed on the pin portion. FIG. It is sectional drawing which shows the cross-sectional shape of the heating coil for tempering, and the preferable hardening hardening layer formed in a pin part.
10 is an enlarged sectional view taken along the line BB in FIG. 5 (corresponding to an enlarged sectional view taken along the line CC in FIG. 7); FIG. FIG. 10B is a diagram showing a cross-sectional shape of a high-frequency induction heating coil and a heating region during flat quenching and flat tempering, and FIG. 10B is a high-frequency induction heating coil for fillet R quenching and fillet R tempering of a pin portion. FIG. 10 (c) is a diagram showing a cross-sectional shape and a heating region at the time of fillet R quenching and fillet R tempering, and FIG. 10 (c) shows a high frequency induction heating coil for the piece R quenching and the piece R quenching of the first journal part It is a figure which shows a heating area | region at the time of a cross-sectional shape and piece R quenching and piece R tempering.
FIG. 11 is a schematic view of a high-frequency tempering device for a crankshaft provided with a high-frequency induction heating coil of a substantially circular solenoid type.
[Explanation of symbols]
1 Crankshaft for 4-cylinder engine
2 (2a-2e) Journal part
3 (3a-3d) Pin part
12 High frequency power supply
12a First high frequency power supply
12b Second high frequency power supply
17a, 17b, 18a, 18b Arc-shaped heating conductor
30a Semi-open saddle type high frequency induction heating coil for quenching (heating coil for quenching)
30b Semi-open saddle type high frequency induction heating coil for tempering (heating coil for tempering)
33a, 33b Arc-shaped heating conductor
40,40 'Induction hardening and tempering equipment
43a, 43b, 44a, 44b Guide member
50 selector
51a-51d guide member
J Induction hardening coil body
K induction tempered coil body
H Outer surface of journal
S Pin outer peripheral surface
X Center axis of crankshaft
Y pin center axis

Claims (6)

クランクシャフトのジャーナル部又はピン部の外周面に高周波焼入及び高周波焼戻を施行するための高周波焼入焼戻装置において、
焼入用半開放鞍型高周波誘導加熱コイルを有する高周波焼入コイル体と、焼戻用半開放鞍型高周波誘導加熱コイルを有する高周波焼戻コイル体とをそれぞれ備え、
前記ジャーナル部又はピン部の中心軸を挟む２方向から移動される前記焼入用半開放鞍型高周波誘導加熱コイルと前記焼戻用半開放鞍型高周波誘導加熱コイルとにより前記ジャーナル部又はピン部の外周面のほぼ全周を取り囲んで、前記焼入用半開放鞍型高周波誘導加熱コイル及び前記焼戻用半開放鞍型高周波誘導加熱コイルを前記ピン部又はジャーナル部の外周面に対向配置し、
この状態の下で、前記クランクシャフトをその中心軸を中心に回転駆動するのに伴って自転運動する前記ジャーナル部の外周面、又は、前記クランクシャフトの中心軸を中心として公転運動を行う前記ピン部の外周面に前記高周波焼入コイル体を追従させながら高周波焼入を行い、次いで前記高周波焼戻コイル体を前記ジャーナル部又はピン部の外周面に追従させながら高周波焼戻するようにしたこと、
を特徴とするクランクシャフトの高周波焼入焼戻装置。In the induction hardening and tempering device for performing induction hardening and induction tempering on the outer peripheral surface of the journal part or pin part of the crankshaft,
An induction hardening coil body having a semi-open saddle type high frequency induction heating coil for quenching and an induction tempering coil body having a half open saddle type high frequency induction heating coil for tempering,
The journal portion or pin portion is formed by the quenching semi-open vertical type high frequency induction heating coil and the tempering half open vertical type high frequency induction heating coil which are moved from two directions across the central axis of the journal portion or pin portion. The quenching semi-open saddle type high frequency induction heating coil and the tempering half open saddle type high frequency induction heating coil are disposed opposite to the outer peripheral surface of the pin part or the journal part. ,
Under this state, the outer peripheral surface of the journal portion that rotates as the crankshaft is driven to rotate about its central axis, or the pin that performs a revolving motion around the central axis of the crankshaft. Induction hardening was performed while following the induction hardened coil body to the outer peripheral surface of the part, and then induction tempering was performed while following the outer peripheral surface of the journal part or the pin part. ,
Crankshaft induction hardening and tempering device. 前記高周波焼入コイル体及び前記高周波焼戻コイル体を、高周波電流経路を切り換える切換器を介して共通の高周波電源にそれぞれ接続し、高周波焼入工程においては、前記切換器により前記高周波焼入コイル体の高周波焼入用半開放鞍型高周波誘導加熱コイルに高周波電流を供給するようにし、高周波焼戻工程においては、前記切換器により前記高周波焼戻コイル体の焼戻用半開放鞍型高周波誘導加熱コイルに高周波電流を供給するようにしたことを特徴とする請求項１に記載のクランクシャフトの高周波焼入焼戻装置。  The induction-hardened coil body and the induction-tempered coil body are respectively connected to a common high-frequency power source via a switching device that switches a high-frequency current path. In the induction hardening process, the induction hardening coil body is used by the switching device. A high-frequency current is supplied to a half-open vertical type induction induction coil for induction hardening of a body, and in the induction tempering step, a half-open vertical type high-frequency induction for tempering the induction tempering coil body by the switch. 2. The induction hardening and tempering device for a crankshaft according to claim 1, wherein a high-frequency current is supplied to the heating coil. 前記高周波焼入コイル体及び前記高周波焼戻コイル体を、それぞれ別の高周波電源に接続し、前記高周波焼入コイル体の焼入用半開放鞍型高周波誘導加熱コイルに高周波電流を供給している期間中に前記高周波焼戻コイル体の焼戻用半開放鞍型高周波誘導加熱コイルにも高周波電流を供給可能としたことを特徴とする請求項１に記載のクランクシャフトの高周波焼入焼戻装置。  The induction-hardened coil body and the induction-tempered coil body are connected to different high-frequency power sources, respectively, and a high-frequency current is supplied to the half-open saddle type high-frequency induction heating coil for quenching the induction-hardened coil body. 2. The induction hardening and tempering device for a crankshaft according to claim 1, wherein a high-frequency current can be supplied also to a semi-open vertical type high-frequency induction heating coil for tempering the induction tempering coil body during the period. . 請求項１乃至３の何れか１項に記載のクランクシャフトの高周波焼入焼戻装置によって平焼入を施したクランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための、前記高周波焼入焼戻装置を構成する高周波焼戻コイル体において、
前記高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、前記クランクシャフトの中心軸に沿う方向における幅が広く、かつ、前記ジャーナル部又はピン部の外周面との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記ジャーナル部又はピン部の外周面との間の距離よりも大きく設定されることを特徴とする高周波焼戻コイル体。The said for performing the induction tempering process with respect to the journal part or pin part of the crankshaft which carried out the flat quenching by the induction hardening and tempering apparatus of the crankshaft of any one of Claims 1 thru | or 3. In the induction tempering coil body constituting the induction hardening and tempering device,
The tempering semi-open saddle type high frequency induction heating coil constituting the induction tempering coil body is compared with the quenching half open saddle type high frequency induction heating coil constituting the induction hardening coil body. The width in the direction along the central axis is wide, and the distance between the outer peripheral surface of the journal part or the pin part is the outer peripheral surface of the half-open vertical type high frequency induction heating coil for quenching and the journal part or the pin part. An induction tempered coil body, characterized in that it is set to be larger than the distance between the two. 請求項１乃至３の何れか１項に記載のクランクシャフトの高周波焼入焼戻装置によってフィレットＲ焼入を施した前記クランクシャフトのジャーナル部又はピン部に対して高周波焼戻処理を行うための、前記高周波焼入焼戻装置を構成する高周波焼戻コイル体において、
前記高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、前記ジャーナル部又はピン部の外周面との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記外周面との間の距離よりも大きく、かつ、前記ジャーナル部又はピン部の外周面から連なるＲ部を含んで前記ジャーナル部又はピン部に対して垂直に立ち上がる部位との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記部位との間の距離との間の距離よりも大きく設定されることを特徴とする高周波焼戻コイル体。An induction tempering process is performed on a journal portion or a pin portion of the crankshaft subjected to fillet R hardening by the induction hardening and tempering device for a crankshaft according to any one of claims 1 to 3. In the induction tempering coil body constituting the induction hardening and tempering device,
The semi-opening saddle type high frequency induction heating coil for tempering constituting the induction tempering coil body is compared with the semi-opening saddle type high frequency induction heating coil for quenching constituting the induction hardening coil body. The distance between the outer peripheral surface of the pin portion is larger than the distance between the semi-open saddle type high frequency induction heating coil for quenching and the outer peripheral surface, and continues from the outer peripheral surface of the journal portion or the pin portion. The distance between the part including the R part and rising vertically with respect to the journal part or the pin part is the distance between the half-open vertical type high frequency induction heating coil for quenching and the part. An induction tempered coil body characterized by being set larger than the above. 請求項１乃至３の何れか１項に記載のクランクシャフトの高周波焼入焼戻装置によって片Ｒ焼入を施した、前記クランクシャフトの端部に位置するジャーナル部に対して高周波焼戻処理を行うための、前記高周波焼入焼戻装置を構成する高周波焼戻コイル体において、
前記高周波焼戻コイル体を構成する焼戻用半開放鞍型高周波誘導加熱コイルは、高周波焼入コイル体を構成する焼入用半開放鞍型高周波誘導加熱コイルと比較して、前記ジャーナル部の外周面との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記外周面との間の距離との間の距離よりも大きく、かつ、前記ジャーナル部の外周面から連なるＲ部を含んで前記ジャーナル部又はピン部に対して垂直に立ち上がる部位との間の距離が、前記焼入用半開放鞍型高周波誘導加熱コイルと前記部位との間の距離より大きく、かつ、前記焼戻用半開放鞍型高周波誘導加熱コイルの前記外周面のみに対向している加熱導体部の前記クランクシャフトの中心軸に沿う方向の幅が、前記焼入用半開放鞍型高周波誘導加熱コイルの前記外周面のみに対向している加熱導体部の前記クランクシャフトの中心軸に沿う方向の幅より大きく設定されることを特徴とする高周波焼戻コイル体。The induction tempering treatment is performed on the journal portion positioned at the end of the crankshaft, which has been subjected to the piece R quenching by the induction hardening and tempering device for a crankshaft according to any one of claims 1 to 3. In the induction tempering coil body constituting the induction hardening and tempering device for performing,
The semi-opening saddle type high frequency induction heating coil for tempering that constitutes the induction tempering coil body is compared with the semi-opening saddle type high frequency induction heating coil for quenching that constitutes the induction hardening coil body. The distance between the outer peripheral surface is larger than the distance between the half-open vertical type high frequency induction heating coil for quenching and the outer peripheral surface, and is continuous from the outer peripheral surface of the journal portion. The distance between the part including the part and the part rising vertically with respect to the journal part or the pin part is larger than the distance between the semi-opening vertical induction heating coil for quenching and the part, and The width in the direction along the central axis of the crankshaft of the heating conductor portion facing only the outer peripheral surface of the tempering semi-open vertical type high frequency induction heating coil is the half open vertical type high frequency induction heating coil for quenching. Only on the outer peripheral surface of Induction tempering coil body, characterized in that it is larger than the width along the central axis of the crank shaft of the heating conductor portion being oriented.
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