JP3875879B2 - Forging product manufacturing method, forging die and forging product manufacturing apparatus - Google Patents

Forging product manufacturing method, forging die and forging product manufacturing apparatus Download PDF

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JP3875879B2
JP3875879B2 JP2001370654A JP2001370654A JP3875879B2 JP 3875879 B2 JP3875879 B2 JP 3875879B2 JP 2001370654 A JP2001370654 A JP 2001370654A JP 2001370654 A JP2001370654 A JP 2001370654A JP 3875879 B2 JP3875879 B2 JP 3875879B2
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JP2003170238A (en
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正広 佐藤
巌 橋本
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Showa Denko KK
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Showa Denko KK
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Description

【０００１】
【発明の属する技術分野】
本発明は、鍛造製品の鍛造方法、鍛造金型および鍛造製品製造装置に関するもので、詳しくは、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法、鍛造金型および鍛造製品製造装置に関するものである。
【０００２】
【従来の技術】
細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品として、例えば、コンロッド（コネクティングロッド）、自転車用クランク、サスペンションリンクがある。図８に内燃機関用コンロッドの概略図を示す。エンジンピストンピンとの接続穴とクランク軸との接続穴を有しており、エンジンピストンとクランク軸とを接続する軸として用いられている。図９に自転車用クランクの概略図を、図１０にサスペンションリンクの概略図を示した。これらを鍛造する方法として太い径の丸棒素材を中央部を細め、端部を太くした一次成形品をバリ出し鍛造法により成形し、さらに仕上げのバリ出し鍛造により製品形状に成形する方法が一般的である。必要に応じて一次成形および仕上げ工程後にトリミングでバリ抜きをおこなっている。
【０００３】
こうした一次成形品を成形する他の手法としては、フォージングロールと呼ばれる成形機によって太い径の素材の中央部を絞ることにより一次成形品を成形した後、製品形状にさらに成形する方法も用いられる。
【０００４】
【発明が解決しようとする課題】
バリ出し鍛造法による一次成形では、太い径部にメタルを充満させるためには太い素材を使用した鍛造成形が必要となり、その為に中央部の主軸などの細い部位からバリを多く出すことが必要になり、材料歩留まりが悪くなる。またメタルバランスが悪いことに起因して細径部の主軸まわりの金型にかかる負荷が大きく、その結果、金型寿命も短くなる。よって、この手法は現実的ではなかった。
【０００５】
フォージングロールの手法においては中央部を絞り込む操作による成形方法であるため、太い径部に凹みなどの形状部を付加することが出来なかった。また、主軸と太い径部の重心線が偏芯している場合の成形ができなかった。さらに太い材料からの一次成形品となるため、長尺棒材を所要の長さの素材に切り出す時のノコ切断作業で発生する切りくずの量が多く、材料歩留まりの観点から好ましくなかった。
【０００６】
特開平１−２３７０３８号公報に示されている閉塞鍛造方法は、素材の丸棒材を上下方向に投入して横から金型で素材を成形して挟み込んでから据え込み加工する方法である。この方法では、ストロークの長いプレスが必要となり、さらに素材の投入、製品の排出に長いストロークの搬送機が必要となり、単一プレス内での一次成形工程、鍛造成形工程、バリ取りトリミング工程を連続して順次おこなうことは困難である。金型を設置するダイセット構造もこれに伴って大型となるため、一次成形工程と本成形（鍛造）工程を同一プレス内へ配置できない。
【０００７】
本発明は上記状況に鑑み、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きく、かつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品を、材料歩留まりを低下させずに生産性が高い方法で製造することができる鍛造製品の製造方法、鍛造金型および鍛造製品製造装置を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明者は、鍛造工程と製品形状の関係について鋭意研究をおこないその知見に基づいて本発明を完成するに至った。
１）上記課題を解決するための第１の発明は、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法において、細径部より細い径の棒材を素材として用いて、上金型と下金型により形成される細径部相当部位内に棒材を配置した後、上金型と下金型を接触させ金型が開かないように加圧させるとともに、その上金型と下金型とが接触したとき棒材は金型内を自由に移動できる状態でその細径部相当部位と棒材の外径とのクリアランスとして棒材の外径の０．２％〜３０％を確保し、続いて上金型および／または下金型に設けた貫通穴に嵌合しながら、金型の空間内に配置されている棒材の方向にパンチを進行させてその棒材方向に進むパンチにより成形位置を決め、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位および細径部を成形する、ことを特徴とする鍛造製品の製造方法である。
２）上記課題を解決するための第２の発明は、垂直な断面積が細径部より大きい部位に凹みを成形することを特徴とする１）の製造方法である。
３）上記課題を解決するための第３の発明は、細径部が据え込み成形されることを特徴とする１）または２）に記載の鍛造製品の製造方法である。
４）上記課題を解決するための第４の発明は、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法に用いる鍛造金型において、接触したときに素材としての棒材より大きい径を有する細径部相当部位を形成する上金型と下金型との組み合わせ金型と、細径部相当部位に続く垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に設けられていて、かつ、金型内に配置される棒材の長手方向に金型の外から空間内に貫通する横穴と、その横穴に嵌合しながら金型内の空間の棒材に向かって進行する手段を有する横パンチと、を有し、上金型と下金型とが接触したとき棒材は金型内を自由に移動できる状態であって細径部相当部位と棒材の外径とのクリアランスとして棒材の外径の０．２％〜３０％が確保され、棒材方向に進む横パンチにより成形位置が決まる、ことを特徴とする鍛造金型である。
５）上記課題を解決するための第５の発明は、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法に用いる鍛造金型において、素材としての棒材より大きい径を有する細径部相当部位を形成するとともに、その棒材が配置され細径部相当部位と棒材の外径とのクリアランスが棒材の外径の０．２％〜３０％となる上金型と下金型との組み合わせ金型と、上金型および／または下金型をクッション機能部を介して取りつけるホルダーと、上金型と下金型により形成される垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に設けられていて、かつ、金型の外から空間内に貫通する穴に侵入するようにホルダーに取りつけたカウンターパンチと、を有し、上記カウンターパンチは、上金型下金型が接触した状態でクッション機能部が縮むことにより、相対的に貫通する穴から金型内に進入してくる、ことを特徴とする鍛造金型である。
６）上記課題を解決するための第６の発明は、一次成形用金型として４）または５）に記載の金型で一次成形品を製造する工程、上記一次成形品を仕上成形用金型により鍛造成形する工程、上記仕上成形用金型により鍛造成形されたバリ付きの鍛造製品のバリをバリ取り用金型によりトリミングして鍛造製品とする工程を、順送りすることにより細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品を製造する鍛造製品の製造方法である。
７）上記課題を解決するための第７の発明は、鍛造製品を製造する鍛造製品製造装置に おいて、単一プレス機内に、一次成形用金型として請求項４または５に記載の鍛造金型、その一次成形用金型で製造された一次成形品を鍛造成形する仕上成形用金型、およびその仕上成形用金型により鍛造成形されたバリ付きの鍛造製品のバリをトリミングして鍛造製品とするバリ取り用金型が配置されて構成されている、ことを特徴とする鍛造製品製造装置である。
【０００９】
【発明の実施の形態】
図２に本発明の鍛造製品に関する概略見取り図の一例を示した。鍛造製品は、細径部（１）とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位（２ａ、２ｂ）を有する。垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位としては、例えば、断面形状が円状でありその中心線が細径部断面中心と同軸もの、断面形状が多角形形状であり中心線が細径部断面中心と同軸のもの、端部断面形状が円状であり中心線が細部断面中心と同軸でなく細径部外周と外周が連続的に繋がっているもの、これらの組み合わせたものを挙げることができる。
【００１０】
本発明の鍛造製品は、たとえばコンロッド、自転車用クランク、サスペンションリンクなどの細径部である主軸の両端に主軸に比べ大きな体積の部位を有する鍛造製品を製造する際の一次成形品として用いることもできる。この場合、コンロッド、自転車用クランク、サスペンションリンクの主軸と一次成形品の細径部の体積とをほぼ一致させ、例えばコンロッドの場合、主軸の両端に有るピストンピン接続部およびクランク軸接続部の各々の体積と、一次成形品の細径部の両端の垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位の体積とをほぼ一致させる。このようにすることにより、一次成形品を本成形する時に金型への負荷が小さくなり金型寿命を長くすることが期待でき、バリ出し量も少ないので材料歩留まりも好ましくなる。
【００１１】
鍛造用一次成形品として用いる場合は、この後に本成形される製品の形状に基づいて主軸や太径部、太い径部に設ける凹みの体積が設計されるのが好ましい。例えば、コンロッドの場合、細径部である主軸部の体積は、本成形される製品の主軸部の１．０５〜１．５倍の体積となるような外径に設計される。細径部よりも大きな断面積を有する部位である太い径部すなわちピストンピンへの接続部の体積は製品の１．０５〜１．５倍の体積で設計される。また、太い径部の中央部に本成形後に機械加工により開けられるピン穴用の凹みに相当する凹みを付加した形に設計される。このように設計することにより完成したピストンピン部の塑性加工率が一次成形品においても高くなるので機械的特性の一つである素材伸び特性が高くなり好ましいからである。主軸部については一次成形に続いて行なわれるバリ出し鍛造工程によってより塑性加工率を高め、伸びは高くなる。一次成形品の細径部である主軸部は、製品の主軸部の１．０５倍以上の体積であると本成形のバリ出し鍛造工程によって機械的特性の伸びが改善されるので好ましい。細径部である主軸部は製品の主軸部の１．５倍を超える体積では、材料歩留まりが悪く、好ましくない。
【００１２】
本発明の鍛造製品を一次成形品としてその後にバリ出し鍛造により製品とする工程において、一次成形品の体積バランスをその後のバリ出し鍛造製品の相似形状とするので材料歩留まりがよく、金型への負担も軽く、メタル未充満部位のない製品を得ることができる。特に主軸部の材料歩留まりは従来の歩留まりが６０〜７０％であったことよりも大幅に改善され、８０〜９５％となった。さらに鍛造ストロークが短く、良好な生産効率（例えば縦鍛造比２００％。）を得ることができるので好ましい。
【００１３】
図１に、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法に用いる金型において、
素材より大きい径を有する細径部相当部位を形成する上金型と下金型との組み合わせ金型と、上金型と下金型により形成される垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に設けられ、金型内に配置される棒状の素材の長手方向に金型の外から空間内に貫通する横穴と、その横穴に嵌合しながら金型内の空間の素材に向かって進行する手段を有する横パンチとを有することを特徴とする鍛造金型の一例を示した。
【００１４】
図１に従って詳しく説明する。
金型は、上ボルスター（２１）、下ボルスター（２７）に取りつけられた、上金型（３０）、下金型（２８）、カムスライダー（２５ａ、２５ｂ）、カム押し下げ棒（２３ａ、２３ｂ）、油圧シリンダー（３２）、ダイスホルダー（２２、２６）と、主成形方向に対して直行する方向から進入する機構を有する横パンチ（２４ａ、２４ｂ）とを含んで構成される。
【００１５】
成形の完了した鍛造用一次成形品を金型外に排出できるようにノックアウトピン（３１、２９）を上金型および下金型に配設している。
【００１６】
細径部相当部位（３６ａ、３６ｂ）は上金型と下金型で囲まれて形成されている。形状は、円柱状、角柱状、円錐台形状、角柱台形状などとすることができる。上金型下金型により形成される細径部相当部位（３６ａ、３６ｂ）は鍛造製品の細形部に等しい径を有する空間を形成している。上金型下金型により形成される細径部相当部位（３６ａ、３６ｂ）は素材より大きい径を有する空間を形成している。本発明の金型では細径部より細い径の棒材を素材として用いて、棒状の素材（３５）は、下金型の細径部相当部位に配置される。
【００１７】
細径部相当部位（３６ａ、３６ｂ）に続いて、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位が成形されるの空間（３７ａ、３７ｂ、３７ｃ、３７ｄ）が設けられている。この空間の形状は、鍛造製品形状にあわせて決めることができ、たとえば円柱形、四角柱形、楕円柱形とすることができる。また細径部相当部位（３６ａ、３６ｂ）と繋がる部位の形状も任意に鍛造製品形状にあわせて設計することができる。
【００１８】
横穴（３４ａ、３４ｂ、３４ｃ、３４ｄ）は、上金型と下金型で囲まれて形成されている。横穴（３４ａ、３４ｂ、３４ｃ、３４ｄ）は、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に、金型内に配置される棒状の素材の長手方向に金型の外から空間内に貫通するように設けられている。
【００１９】
太径部を成形する垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位には凹みを形成する凸部が付加することができ、この例の場合は、上金型、下金型に凸部（３８ａ、３８ｂ、３８ｃ、３８ｄ）が設けられている。凹みは、位置、個数、向き、形状、深さを最終製品の形状に合わせて任意に選んで穿設することができる。その場合、例えば、凹みを形成する凸部は、上金型、下金型の凸が対抗する位置に配設されて、鍛造によって太径部の凹の底が薄肉化するような形状を配置すしても良いし、或いは、凸部が上金型、下金型の一方だけに配設されていても良い。
【００２０】
細径部相当部位（３６ａ、３６ｂ）は素材より大きい径を有する空間を形成しているので、上金型と下金型を接触させた場合にも、素材を塑性加工することなく、素材は金型内を自由に移動できる状態となっている。その結果、素材投入時の位置決めがずれていても、上金型、下金型に囲まれた空間に外部より空間内に配置されている素材の方向にパンチを進行させることによって、適切な位置に配置されて塑性加工が開始される。その結果、例えば、単一プレス機内で後工程を一緒に処理する場合など、素材の搬送が容易になる。
【００２１】
細径部相当部位（３６ａ、３６ｂ）は素材より大きい径を有する空間を形成しているので、上金型、下金型に囲まれた空間に外部より空間内に配置されている素材の方向にパンチを進行させて成形させた場合に、素材は細径部において据え込み加工される。その結果、バリ出しすることなく、所望の機械的な強度を得るために充分な加工率を得ることができるので好ましい。据え込み加工されるので、連続鋳造棒を素材とした場合、連続鋳造棒の断面の中心から放射状の組織の特徴を生かすことができる。
【００２２】
主成形方向と直交する方向に前後する横パンチを金型内の空間の素材に向かって進行させる手段の一例として、カムスライダー（２５ａ、２５ｂ）による方法を採用している。この動きを説明する。上金型は外径を上型ホルダー（２２）に拘束された状態で上受圧板（３３）に固定された油圧シリンダー（３２）によって押し下げられた位置、上受圧板との間に空間をもって固定されている。上金型の外側に配置したカム押し下げバー（２３ａ、２３ｂ）はプレス作動方向（主成形方向）に下降し、カムスライダー斜面（３９ａ、３９ｂ）に接触する。カム押し下げバーにも斜面（４０ａ、４０ｂ）が付加されており、その結果、カムスライダーは台の上を横方向に移動する。カムスライダーの先端には横パンチ（２４ａ、２４ｂ）が備えられており、下金型および上金型に設けられた横穴（３４ａ、３４ｂ、３４ｃ、３４ｄ）にガイドされて閉塞状態の金型空間に挿入される。横パンチは細径素材を加圧して鍛造用一次成形品の太径部へ素材を塑性流動させて充満させる。カムスライダーには下金型との間にバネ（４１ａ、４１ｂ）が設けられており、バネの反力によって待機位置まで押し戻される。
【００２３】
続いてこの金型の、成形動作について図３、４を用いて説明する。
主成形動作により上金型が下金型に向かって下降する。下降した上金型は下金型と接触する。図３は上金型と下金型が接触した状態を示している。すなわち、素材を配置した金型内の空間以外の金型の面（図３における手前側と奥側の金型の面）が接触している。細径部より細い径の棒材を素材として用いているので、この時点では素材（３５）は金型細径部相当部よりも細いので素材は塑性加工を受けていない。上金型はさらに下降を続け、上金型を介して油圧シリンダーが縮み、カム押し下げバーがカムスライダー斜面と接触して、金型が接触して開かないように加圧された状態で横パンチが上金型と下金型により形成される貫通穴を移動して素材を据え込み成形する。横パンチは下金型に形成された貫通穴面に載置された状態で待機しても良いし、貫通穴外部にて待機しても良い。図４はプレス機が下死点の状態を示し、横パンチが進行を完了して製品成形が完了した状態を示している。
【００２４】
素材は細径部では据え込み加工されて、さらに細径部より大きな断面積かつ細径部直径が含まれる断面を有する部位にも充満して成形が完了する。
製品はノックアウトピンにより持ち上げられ金型から系外へ排出される。
【００２５】
図５に、本発明の、別の金型の例を示す。
細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法に用いる金型において、
素材より大きい径を有する細径部相当部位を形成する上金型と下金型との組み合わせ金型と、上金型および／または下金型を、クッション機能部を介して取りつけるホルダーと、上金型と下金型により形成される垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に設けられた金型の外から空間内に貫通する穴に侵入するようにホルダーに取りつけたカウンターパンチとを有することを特徴とする鍛造金型の一例を示す。
【００２６】
クッション機能を発する機構のクッション機能部としては、油圧シリンダー、ガスシリンダー、スプリングなどが挙げられる。
【００２７】
図５では上金型および下金型に油圧シリンダー、カウンターパンチの機構を設けているがどちらかの金型にのみ設けることも可能である。また、一つの金型に複数設けることも可能である。
【００２８】
図５に従って詳しく説明する。
上金型（５５）は上金型ホルダー（５４）に外径を拘束されており、上金型上部に配置した油圧シリンダー（５１ａ）により押し下げられており、受圧板（５３）との間に空間がある。カウンターパンチ（５７ａ、５７ｂ）は受圧板に固定されており、上金型に設けられた貫通穴（６３ａ、６３ｂ）と嵌合している。油圧シリンダーも受圧板に固定されている。
【００２９】
下金型（６０）は下金型ホルダー（５６）に外径を拘束されており、下金型下部に配置した油圧シリンダー（５１ｂ）により押し上げられており、受圧板（５９）との間に空間がある。カウンターパンチ（５７ｃ、５７ｄ）は受圧板に固定されており、下金型に設けられた穴（６５ａ、６５ｂ）と嵌合している。油圧シリンダーも受圧板に固定されている。
【００３０】
成形の完了した鍛造用一次成形品を金型外に排出できるようにノックアウトピン（６１、６２）を上金型および下金型に配設している。
【００３１】
これらの構成要素が、上ボルスター（５２）、下ボルスター（５８）に取りつけられている。
【００３２】
本発明の金型では細径部より細い径の棒材を素材として用いて、棒状の素材（６４）は、下金型の細径部相当部位に配置される。
【００３３】
細径部相当部位（６６ａ、６６ｂ）は上金型と下金型で囲まれて形成されている。形状は、円柱状、角柱状、円錐台形状、角柱台形状などとすることができる。上金型下金型により形成される細径部相当部位（６６ａ、６６ｂ）は鍛造製品の細形部に等しい径を有する空間を形成している。上金型下金型により形成される細径部相当部位（６６ａ、６６ｂ）は素材より大きい径を有する空間を形成している。
【００３４】
細径部相当部位（６６ａ、６６ｂ）に続いて、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位が成形されるの空間（６７）が設けられている。この空間の形状は鍛造製品にあわせて決めることができ、たとえば円柱形、四角柱形、楕円柱形とすることができる。また細径部相当部位（３６）と繋がる部位の形状も任意に鍛造製品形状にあわせて設計することができる。
【００３５】
続いてこの金型の、成形動作について図６，７を用いて説明する。
下金型の細径部相当部位に素材（６４）を投入する。上金型は鍛造機の主成形動作によって下金型に向かって下降する。図６に上金型と下金型が接触した状態を示した。上金型下面と下金型上面が接触した状態で油圧シリンダーの圧力により金型が開かないように加圧される。この時点では素材は金型細径部よりも細いので素材は塑性加工を受けていない。
【００３６】
主成形力が油圧シリンダーの圧力よりも勝っているので上金型下金型が接触した状態で油圧シリンダーが縮み、受圧板に固定されているカウンターパンチが上金型、下金型に設けた穴（６３ａ、６３ｂ、６５ａ、６５ｂ）に嵌合しながら相対的に貫通穴から金型内に進入してくる。カウンターパンチにより、素材は据え込み加工されて細径部に充満し、細径部より大きな断面積かつ細径部直径が含まれる断面を有する部位にメタルが充満して成形が完了する。
【００３７】
上金型下金型に備えられたノックアウトピンにより製品は金型からはずされ、金型外へ排出される。
【００３８】
カウンターパンチを用いているので、上下方向からパンチを進入させることができ、その結果深い凹部の形状が付加できるので好ましい。
【００３９】
本発明の金型では、細径部相当部位と棒材の外径とのクリアランスが棒材の外径の０．２％〜３０％（より好ましくは、０．５％〜１０％。）であるのが好ましい。例えば、２０〜５００ｍｍの直径を有する場合、クリアランスが０．０４〜１５０ｍｍ（より好ましくは０．１〜５０ｍｍ。）であることが好ましい。金型が接触後も素材が素材長手方向に移動可能なので横パンチにより材料位置を決めることができるため素材長手方向の位置決めが不要で好ましい。クリアランスが０．２％以上であると素材の長手方向の動きが良好であるので好ましい。クリアランスが３０％を超えるとと素材が成形時に座屈して巻き込みなどの鍛造欠陥を生じることがあるので好ましくない。
【００４０】
棒材外径と金型細径部の長さとの比と、材料の鍛造時の温度条件（冷間、温間）とその時の棒材の機械的特性と、座屈を起こさない条件と、からこの範囲でクリアランスを設定することができる。
【００４１】
クリアランスとは、細径部相当部位と棒材の外径との間の、隙間の平均値のことである。
【００４２】
本発明の金型を用いた、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法は、
細径部より細い径の棒材を素材として用いて、上金型下金型により形成される細径部相当部位内に棒材を配置した後、上金型と下金型を接触させ金型が開かないように加圧させた後、上金型および／または下金型に設けた貫通穴に嵌合しながら、金型の空間内に配置されている棒材の方向にパンチを進行させて、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位および細径部を成形することを特徴とする鍛造製品の製造方法となる。
【００４３】
本発明の製造方法は、上金型下金型が完全に閉塞状態で開かないように加圧された状態から素材を塑性変形流動させ、細径棒素材を素材長手方向に垂直方向から成形するため、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品を材料歩留まりを低下させずに生産性が高い製造方法となる。
【００４４】
本発発明の製造方法は、細径部より細い径の棒材を素材として用いて、細径部を囲む空間が上金型下金型により形成される細径部相当部位内に棒材を配置した後、上金型と下金型を接触させ、金型が開かないように加圧させた後、パンチを進行させているので金型の隙間が存在する状態で素材を塑性変形流動させることがなく、上金型下金型が完全に閉じた状態から塑性変形流動が起こるので完全な閉塞鍛造となり製品外周部にバリが生じないので材料歩留まりがよく好ましい。
【００４５】
本発明の金型を用いた製造方法では、水平方向に素材を置くので素材の配置が安定しており、また素材方向に進むパンチにより成形位置が決まるので、投入した素材と金型の長手方向の中心位置との関係を厳密に管理する必要はない。パンチの移動とともに素材は移動して鍛造製品で求められる位置に修正されるので、長手方向の素材位置決め精度を要求されないので好ましい。金型が接触して開かないように加圧した後に据え込み成形するので製品の外周にバリが発生せず好ましい。
【００４６】
本発明の製造方法は、本発明の金型を用いることにより、垂直な断面積が細径部より大きい部位に凹みを好ましく成形することができる。
【００４７】
本発明の製造方法は、本発明の金型を用いることにより、細径部を据え込んで好ましく成形することができる。
【００４８】
従来の金型に上記の構成品（油圧シリンダー、カムスライダー、横パンチ、カウンターパンチなど）を設置することで、本発明の金型構造を構成することができる。その結果、コンパクトな金型構成が可能であり、生産設備が安価になり好ましい。
【００４９】
本発明では、例えばＡ２０１４，Ａ２０１７，Ａ２６１８といったＡｌ−Ｃｕ系アルミ合金を素材とすることが、鍛造製品において高温強度に優れるのでコンロッドのような高温で高負荷にさらされる部品を鍛造製品とする場合の材質としては好ましい。例えばＡ６０６１，Ａ６０８２といったＡｌ−Ｍｇ−Ｓｉ系アルミ合金を素材とすることが、鍛造製品において中程度の強度を持ち靭性および耐食性に優れるのでサスペンションリンクのような水濡れ環境で繰返し荷重下で使用される部品を鍛造製品とする場合の材質としては好ましい。
【００５０】
例えば、コンロッドにおいて必要とされる高温強度および耐摩耗性を得るため、ＣｕおよびＳｉを含むアルミニウム合金が好ましい。Ａｌ−５〜２０質量％Ｓｉ−１〜７質量％Ｃｕ−０．１〜１．０質量％Ｍｇを含むアルミニウム合金を素材とすることが好ましい。鍛造製品が、高温強度、耐摩耗性に優れるので好ましい。アルミニウム合金であるので鉄部品に比べ密度が低く、軽量化できるので好ましい。Ｓｉが５％未満であると十分な耐摩耗性が得られず、２０％を超えると初晶ケイ素粒子数過剰による強度低下が予想される。Ｃｕが１％未満であると充分な強度が得られない。７％を超えると粗大な金属間化合物を生じ、疲労破壊の起点となるため好ましくない。０．１％未満のＭｇでは充分な強度が得られない。１．０％を超えると効果を発揮せず、過剰となる。
【００５１】
本発明の金型は、金型構造が鍛造製品成形部を長手方向で軸線を含む平面で上下方向に分割した金型であるので、金型設計の自由度が高くなる。その結果、金型において、細径部と垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位の中心線を一致させる必要はない。その結果、最終製品形状が細径部と垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位との重心線が一致していない場合に用いる製品の成形可能となる。
【００５２】
図１１に、細径部の軸方向の中心線（１３１）と垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位の軸方向の重心線（１３２ａ、１３２ｂ）とが同一直線上でないことを特徴とする鍛造製品の一例を示した。
【００５３】
このような形状の鍛造製品は、本発明の金型、製造方法を用いて製造することができる。上金型と下金型により形成される細径部成形相当部位中心線を細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位の重心線と前後方向にずらして配置している金型を用いることで、同一直線上でないものを製造することができる。
【００５４】
鍛造製品の細径部の中心線と細径部より大きな断面積かつ細径部直径が含まれる断面の重心線が同一直線上でないので細径部の中心線と細径部より大きな断面積かつ細径部直径が含まれる断面の重心線が同一直線上でない鍛造製品の予備成形品として好ましい。
【００５５】
従来のフォージングロールを用いた場合では、素材を上下のロールで挟み込んで中央部を絞りこんで成形するため、絞りこまない太径部と絞りこんだ細径部の中心線が一致することになる。そのため偏芯した鍛造製品を成形することが不可である。一方バリ出し鍛造では、中心線が一致しない偏芯した鍛造製品形状を彫り込んだ金型を用いることで成形が可能だが、製品の外周にバリを発生させることになり材料歩留まりが悪く、金型にかかる負担も大きく実用的でない。
【００５６】
本発明の鍛造方法は、バリのない偏芯した鍛造製品を容易に成形することができるので好ましい。
【００５７】
また、一次成形品として偏芯した本発明の鍛造製品を用いて、仕上げ鍛造により偏芯した鍛造製品を成形する場合には、材料歩留まりがよく、仕上げ金型の鍛造成形時の負荷が小さく金型寿命が長くなるので好ましい。
【００５８】
図２に、垂直な断面積が細径部より大きく、かつその断面の投影面に細径部断面の投影が含まれる部位が一方よりも他方が大きく、更に、凹部の形状もそれに合わせて大きく成形した鍛造製品の一例を示した。これらの部位は、それぞれに異なっていても良いし、同じでも良く、最終製品形状を得るための鍛造形状に合わせられる。
【００５９】
このような形状の鍛造製品は、本発明の金型、製造方法を用いて製造することができる。上金型および下金型の細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を成形する部位に製品の凹みに相当する突起（凸部）が設けてある金型を用いることで、細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に凹みを有する鍛造製品を製造することができる。突起部は所望の凹みの形状に合わせて設けることができる。たとえば図１に示した金型では、符号３８ａ、３８ｂ、３８ｃ、３８ｄがその突起である。
【００６０】
カウンターパンチを突起とすることが可能である。カウンターパンチを押し込むことで、細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に凹みを形成することが可能である。たとえば図５にしめした金型では、符号５７ａ、５７ｂ、５７ｃ、５７ｄがそのカウンターパンチである。カウンターパンチにより形成される凹みは深く形成することができるので好ましい。
【００６１】
凹みを有している製品を一次成形品として用いる場合、その後の本成形において凹みのある製品を鍛造成形する場合に一次成形品において本成形製品形状の凹みの大きさに応じて凹みを付加することにより材料歩留まりを向上させ、金型にかかる負荷を低減させることができるので好ましい。
【００６２】
本製品を一次成形品として用いることにより、例えばコンロッドのピストンピン接続部穴が一次成形品において凹みを付加した部位となるので、本成形において生じるバリの量が少なくでき、材料歩留まりが改善され、また本成形型のピストンピン接続部穴成形部である金型凸部の負担を小さくできる。
【００６３】
次ぎに本発明の鍛造製品を一次成形品として用いる場合の鍛造製品の製造方法を説明する。
一次成形用金型として前述したいずれかの金型、仕上成形用金型、バリ取り用金型を配置して、
一次成形用の金型で一次成形品を製造する工程、一次成形品を仕上成形用金型により鍛造成形する工程、発生するバリをトリミングして鍛造製品とする工程を、順送りすることによって
細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品を製造する。各金型は、並列に配列してあるのが搬送装置が容易になるので好ましい。
【００６４】
単一プレス機内に、各金型を配列するのが好ましい。装置をコンパクトにして生産効率を上げることができるからである。また、単一装置内に配列すると、素材の搬送時間が短くなるので、素材の加熱を効率良く実施できるので好ましい。
【００６５】
製造方法に用いる鍛造製品製造装置を正面から見た図１２に従って説明する。単一プレス機（１２１）内に、一次成形用金型（１２２ａ、１２２ｂ）、仕上成形用金型（１２３ａ、１２３ｂ）、バリ取り用金型（トリミング金型）（１２４ａ、１２４ｂ）を配置してある。配置は一次成型用金型、仕上成形金型、バリ取り用金型の順番で並列に配置されているのが好ましい。一次成形用金型には前述した本発明の金型の何れかを用いる。各金型間の加工対象物を搬送する手段（図示せず。）が設けられている。搬送する手段として、たとえばフィードバーにワークつかみ用の爪を具備した搬送機、ロボットを用いることができる。搬送する手段により、細径棒素材を一次成形金型へ投入し、一次成形が完了した一次成形品を本成形金型へ送り、本成形が完了したバリ付き製品をバリ取り用金型へ送り、バリ取り用金型からバリを除去した製品を排出する。
【００６６】
次ぎに動作を説明する。各工程で成形、加工して得られる製品の形状を図１２の各金型に対応して示した。
【００６７】
一次成形用金型では、細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する一次成形品（１２５）を、細径部より細い径の棒材を素材として用いて、細径部を囲む空間が上金型下金型により形成される細径部相当部位内に棒材を配置した後、上金型と下金型を接触させ、金型が開かないように加圧させた後、上金型および／または下金型に設けた貫通穴に嵌合しながら上金型下金型に囲まれた空間に外部より空間内に配置されている素材の方向にパンチを進行させて垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位および細径部を据え込み成形する。
【００６８】
成形された一次成形品は仕上げ鍛造金型によりバリ付きの鍛造製品（１２６）となる。バリ付きの鍛造製品はトリミング金型によりバリ（１２８）を取り、鍛造製品（１２７）となる。
【００６９】
素材の加熱は、例えば、最初に４００〜４５０℃まで加熱して２工程の成形をすることができる。または必要に応じて、工程間で加熱することができる。金型温度は、２５０℃〜４００℃程度に加熱するのが好ましい。トリミング金型は加熱を必ずしも必要とはしない。潤滑剤は油性の黒鉛系潤滑剤を固定スプレーで噴霧状にして塗布するのが好ましい。
【００７０】
これらの金型を配置しているので順次工程により生産性の高い製造方法となるので好ましい。横置き金型であるので縦鍛造に比べ、プレスストロークが短いので生産タクトタイムが短く、生産性が高くできるので好ましい。順次送りを実施する手段を自動搬送装置にすることによりプレス連続運転（上死点での待機時間がなく、１サイクル完了と同時に次のサイクルが開始される。）が可能となり、生産性の高い順次工程を自動的に運転することが可能で省力の面でも好ましい。
【００７１】
以上述べてきた各本発明の製造方法は、素材として細径の連続鋳造により製造されるものを用いるのが好ましい。連続鋳造棒は、凝固速度が速く、素材外径から中心に向けての凝固組織となっているので繊維状の組織の押出し棒に比べ、遷移金属元素が微細分散しているので再結晶しにくく、機械的特性が良好で、高温強度に優れる。
【００７２】
さらに、負荷の高い主軸についてはより強度を高めるために繊維状の組織である方が好ましい。鍛造本成形においてバリ出し鍛造とすることにより、バリ出しの方向へのメタルフローが得られ、機械的特性の伸び特性が向上するため、製品強度と靭性のバランスの良い製品とすることができる。なお、用途によっては繊維組織による強度の向上を求めることが無い場合は、バリ出し鍛造ではなく閉塞鍛造とすることができる。より発生するバリ量を削減することができるので好ましい。
【００７３】
鍛造潤滑剤として油性黒鉛潤滑剤を用いることが好ましい。金型温度を高い場合でも金型表面に均一な皮膜が形成でき、噴霧状にして塗布することで広範囲に短時間で塗布可能であるからである。
【００７４】
以上述べてきた各本発明の製造方法では、以下のような熱処理を施すことが好ましい。
鍛造用素材は鍛造する前に予備加熱処理を施す。予備加熱処理の温度条件は３５０℃〜（アルミニウム合金の固相温度−１０）℃での範囲とする。処理時間は鍛造用素材全体の温度が予備加熱温度範囲に到達するまでとし、その後鍛造工程に入る。３５０℃未満では鍛造用素材を熱間鍛造した時に充分な塑性流動が得られず、又（アルミニウム合金の固相温度−１０）℃を超えると鍛造用素材にバーニング（局所溶解）が発生するおそれがある。バーニングが発生すると鍛造製品の強度が激しく劣化するか、製品がフクレ、ミクロシュリンケージなどの局所溶解による欠陥を生じるので好ましくない。
【００７５】
鍛造は通常、熱間にて行われるので、素材に予備加熱を行うだけでなく、金型も加熱する。加熱温度は１００〜４００℃とすることができる。加熱温度は、鍛造する形状、鍛造設備の種類、使用される素材の合金の種類、その他鍛造上の要因によって選択される。温度が低すぎると素材からの抜熱が大きくなり、加工性が劣って素材の塑性流動が不十分となる。温度が高すぎると、金型の強度が低下し、摩耗、欠けなどの破損が起こりやすく、金型寿命の観点から好ましくない。鍛造に際しては金型に潤滑剤を塗布してから実施するのが好ましい。
【００７６】
鍛造によって得られた鍛造製品は、そのまま使用することも出来るが、Ｃｕ、Ｍｇ、Ｚｎ、Ｓｃ、Ａｇなどが添加された合金では、熱処理によって材料の機械的特性が向上するので、熱処理として人工時効処理を施すのが好ましい。人工時効処理は、たとえば、加熱温度が４００〜５５０℃で保持時間を０．２〜１０時間行った後に直ちに鍛造製品を水中に没して行う溶体化処理処理と、その後１２０〜２５０℃で０．２〜２０時間の焼き戻しを行うことが好ましい。また、焼戻し処理を温度条件を変えて何段階かに分けて行なっても良い。これにより、硬度を始めとして、機械的特性（例えば引張強度、０．２％耐力、伸び）や疲労強度を高めることが出来る。
【００７７】
熱間鍛造に供する前に、鍛造性と、鍛造後の人工時効処理性をより改善する場合は、素材を均質化処理するのが好ましい。均質化処理とは、鍛造製品の機械的強度や高温使用時の強度を高めるために添加されているＣｕやＭｇ等の添加金属が鋳造時に生じたミクロ偏析した状態を高温で加熱処理することで、アルミ基地内に均一に分散させることである。それにより鍛造時の加工性と、後工程の人工時効処理後の機械的特性の均一性を確保することができる。均質化処理条件の条件としては、４００℃〜（使用する合金の固相温度−１０）℃の温度範囲、保持時間１〜３０時間を挙げることができる。
【００７８】
一方、使用される合金成分、あるいは鍛造製品の形状によっては、鍛造前に施される素材への予備加熱を利用して均質化処理と同じ効果を得ることが可能であり、その場合は、鍛造前の予加熱工程の保持時間を１時間以上と長くすることで素材の均質化処理と同等の効果を得ることができる。また、使用される合金成分、あるいは鍛造製品の形状によっては鍛造後に施される熱処理工程を利用して均質化処理と同じ効果を得ることが可能であり、この場合は人工時効処理工程の溶体化処理時の保持時間を長くすることで素材の均質化処理と同等の効果を得ることができる。
【００７９】
【実施例】
[実施例１]
φ２８ｍｍ（直径２８ｍｍ）のＡ２０１４アルミ合金長尺材を長さ１８０ｍｍにノコ切断機により切断し、鍛造用素材とした。図１と同様な構成の金型で、細径部相当部の外径がφ２９ｍｍ、長さ５０ｍｍであり、細径部相当部の両端にφ３５ｍｍ、長さ４０ｍｍの円柱形状の太径部と１０ｍｍの４５°の斜面で細径部と接続している図２と同様な細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の形状を彫り込んだ金型を準備した。太径部には縦２０ｍｍ、横２０ｍｍ、高さ１０ｍｍの凸形状が上金型および下金型に２ヵ所づつ付加されている。この金型を用いて、以下の製造条件にて鍛造製品を鍛造成形した。
【００８０】
素材は４２０℃に加熱し、金型に油性の黒鉛系潤滑剤を１ｇスプレー塗布した。金型温度は上金型、下金型ともに成形部表面を３００℃に加熱した。
【００８１】
６３０ｔリンクモーション鍛造機に金型を配置して、素材を細径部相当位置に置き、成形した。バリのない鍛造製品が得られた。
【００８２】
得られた鍛造製品を一次成形品としてコンロッド成形金型を用いて図８に示した内燃機関用コンロッド部品を鍛造成形した。素材温度は４２０℃まで加熱し、金型に油性黒鉛系潤滑剤を２ｇスプレー塗布した。金型温度は、上金型、下金型ともに成形部表面温度が３００℃となるように加熱した。
【００８３】
鍛造した製品外周にバリを生じたのでバリ取り型でバリを打ち抜き除去した。高温強度に優れる良好なコンロッド鍛造製品が得られた。
【００８４】
[実施例２]
φ２８ｍｍのＡｌ−１２質量％Ｓｉ−４質量％Ｃｕ−０．５質量％Ｍｇおよびその他微量の不純物元素からなるアルミ合金長尺材を長さ１８０ｍｍにノコ切断機により切断し、鍛造用素材とした。図１と同様な構成の金型にて細径部の外径がφ２９ｍｍ、長さ５０ｍｍであり、細径部の両端にφ３５ｍｍ、長さ４０ｍｍの円柱形状の太径部と１０ｍｍの４５°の斜面で細径部と接続している図２に示したような形状を彫り込んだ金型を準備した。太径部には縦２０ｍｍ、横２０ｍｍ、高さ１０ｍｍの凸形状が上金型および下金型に２ヵ所づつ付加されている。この金型を用いて、以下の製造条件にて鍛造製品を鍛造成形した。
【００８５】
素材は４２０℃に加熱し、金型に油性の黒鉛系潤滑剤を１ｇスプレー塗布した。金型温度は上金型、下金型ともに成形部表面を３００℃に加熱した。
【００８６】
６３０ｔリンクモーション鍛造機に金型を配置して、素材を細径部相当位置に置き、成形した。バリのない鍛造製品が得られた。
【００８７】
得られた鍛造製品を一次成形品としてコンロッド成形金型を用いて図８に示すような内燃機関用コンロッド部品を鍛造成形した。素材温度は４２０℃まで加熱し、金型に油性黒鉛系潤滑剤を２ｇスプレー塗布した。金型温度は、上金型、下金型ともに成形部表面温度が３００℃となるように加熱した。
【００８８】
鍛造した製品外周にバリを生じたのでバリ取り型でバリを打ち抜き除去した。耐摩耗性および高温強度に優れる良好なコンロッド鍛造製品が得られた。
【００８９】
[実施例３]
φ３２ｍｍのＡ６０６１アルミ合金長尺材を長さ１８０ｍｍにノコ切断機により切断し、鍛造用素材とした。図５と同様な構成の金型を用いて、細径部の外径がφ３５ｍｍ、長さ８０ｍｍであり、細径部の両端にφ３５ｍｍ、長さ３０ｍｍの円柱形状の太径部と１０ｍｍの４５°の斜面で細径部と接続している図２に示すような形状を彫り込んだ金型を準備した。太径部長手方向中央にはφ１５ｍｍ、高さ１０ｍｍの凸形状が上金型および下金型に２ヵ所づつ付加されている。この金型を用いて、以下の製造条件にて鍛造製品を鍛造成形した。
素材は４２０℃に加熱し、金型に油性の黒鉛系潤滑剤を１ｇスプレー塗布した。金型温度は上金型、下金型ともに成形部表面を３００℃に加熱した。
６３０ｔリンクモーション鍛造機に金型を配置して、素材を細径部相当位置に置き、成形した。バリのない良好な鍛造製品が得られた。
得られた鍛造製品を一次成形品としてサスペンションリンク成形金型を用いて図１０に示すようなサスペンションリンク部品を鍛造成形した。
【００９０】
素材温度は４６０℃まで加熱し、金型成形部全体に油性黒鉛系潤滑剤を２ｇスプレー塗布した。金型温度は、上金型、下金型ともに成形部表面温度が３００℃となるように加熱した。サスペンションリンク外周にはバリを生じていたのでバリ取り型を用いてバリを除去して製品を得た。耐食性に優れる良好なサスペンションリンク鍛造製品が得られた。
【００９１】
【発明の効果】
本発明の製造方法は、
細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法において、細径部より細い径の棒材を素材として用いて、上金型と下金型により形成される細径部相当部位内に棒材を配置した後、上金型と下金型を接触させ金型が開かないように加圧させた後、上金型および／または下金型に設けた貫通穴に嵌合しながら、金型の空間内に配置されている棒材の方向にパンチを進行させて、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位と細径部を成形することを特徴とする鍛造製品の製造方法であるので、材料歩留まりを低下させずに生産性が高い製造方法となる。
【００９２】
本成形の金型に与える負荷が小さく、欠肉または未充満な箇所を抑えて成形することができるので、切削加工代の少ないニアネット形状のコンロッド部品やサスペンションリング部品、自転車クランク部品等を、材料歩留まりを向上させ工数低減した高い生産性のもとに製造することができる。
【図面の簡単な説明】
【図１】本発明の鍛造金型の一例の概略構成の断面図である。
【図２】本発明の鍛造製品の一例の概略見取り図である。
【図３】本発明の鍛造金型の一例の上下型接触時の概略構成の断面図である。
【図４】本発明の鍛造製品の一例の下死点の状態を説明する図である。
【図５】本発明の鍛造金型の別の一例の概略構成の断面図である。
【図６】本発明の鍛造金型の別の一例の上下型接触時の状態を説明する図である。
【図７】本発明の鍛造金型の別の一例の下死点の状態を説明する図である。
【図８】内燃機関用コンロッド鍛造製品の概略見取り図である。
【図９】自転車用クランク鍛造製品の概略見取り図である。
【図１０】サスペンションリンク鍛造製品の概略見取り図である。
【図１１】本発明の鍛造製品の一例の概略断面図である。
【図１２】 本発明の製造方法に用いる鍛造製品製造装置の概略見取り図である。
【符号の説明】
１：細径部
２ａ、２ｂ：垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位
３ａ、３ｂ：凹み
２２：ダイスホルダー
２３ａ、２３ｂ：カム押し下げ棒
２４ａ、２４ｂ：横パンチ
２５ａ、２５ｂ：カムスライダー
３０：上金型
３１：ノックアウトピン
３２：油圧シリンダー
３４ａ、３４ｂ、３４ｃ、３４ｄ：横穴
３５：棒状の素材
３６ａ、３６ｂ：細径部相当部位
３７ａ、３７ｂ、３７ｃ、３７ｄ：垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位が成形される空間
３８ａ、３８ｂ、３８ｃ、３８ｄ：凸部
３９ａ、３９ｂ：カムスライダー斜面
４０ａ、４０ｂ：カム押し下げ棒斜面
４１ａ、４１ｂ：バネ
５１ａ、５１ｂ：油圧シリンダー
５３：受圧板
５４：上金型ホルダー
５５：上金型
５７ａ、５７ｂ、５７ｃ、５７ｄ：カウンターパンチ
５９：受圧板
６０：下金型
６３ａ、６３ｂ：上金型に設けられた穴
６５ａ、６５ｂ：下金型に設けられた穴
６６ａ、６６ｂ：細径部相当部位
６７：垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位が成形される空間
１２１：鍛造機
１２２ａ、１２２ｂ：一次成形用金型
１２３ａ、１２３ｂ：仕上成形用金型
１２４ａ、１２４ｂ：バリ取り用金型[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a forging method for forging products., ForgingMold makingAnd forging product manufacturing equipmentMore specifically, a forged product having a small diameter portion and a portion in which the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the small diameter portion and the projection of the cross section of the small diameter portion is included in the projection plane of the cross section. Manufacturing method, ForgingMold makingAnd forging product manufacturing equipmentIt is about.
[0002]
[Prior art]
As a forged product having a narrow-diameter portion and a portion in which the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the thin-diameter portion and the projection of the cross-section includes the projection of the cross-section of the small-diameter portion, for example, a connecting rod (connecting Rod), bicycle crank, and suspension link. FIG. 8 shows a schematic view of a connecting rod for an internal combustion engine. It has a connection hole for the engine piston pin and a connection hole for the crankshaft, and is used as a shaft for connecting the engine piston and the crankshaft. FIG. 9 shows a schematic diagram of a bicycle crank, and FIG. 10 shows a schematic diagram of a suspension link. As a method of forging these, a method is generally used in which a large-diameter round bar material is thinned at the center, a primary molded product with a thickened end is formed by deburring and forging, and then formed into a product shape by final deburring and forging. Is. If necessary, burrs are removed by trimming after the primary forming and finishing steps.
[0003]
As another method for forming such a primary molded product, a method of forming the primary molded product by narrowing the center portion of the material having a large diameter with a molding machine called a forging roll and then further forming the product into a product shape is also used. .
[0004]
[Problems to be solved by the invention]
In the primary forming by deburring and forging method, it is necessary to forge using a thick material in order to fill the thick diameter part with metal, and for that purpose, it is necessary to put out a lot of burrs from thin parts such as the main shaft in the center part. And the material yield deteriorates. Further, due to the poor metal balance, the load applied to the mold around the main shaft of the small diameter portion is large, and as a result, the mold life is shortened. Therefore, this method was not realistic.
[0005]
Since the forging roll method is a forming method by an operation of narrowing down the central portion, it has been impossible to add a shape portion such as a dent to a thick diameter portion. In addition, molding was not possible when the main axis and the center of gravity line of the thick diameter portion were eccentric. Furthermore, since it becomes a primary molded product from a thicker material, the amount of chips generated in the saw cutting operation when cutting a long bar material into a raw material of a required length is large, which is not preferable from the viewpoint of material yield.
[0006]
The closed forging method disclosed in Japanese Patent Application Laid-Open No. 1-237038 is a method in which a round bar material is inserted in the vertical direction, the material is molded with a mold from the side and sandwiched, and then upsetting is performed. This method requires a press with a long stroke, and further requires a long-stroke transporter for material input and product discharge. The primary forming process, forging process, and deburring trimming process are continuously performed in a single press. Therefore, it is difficult to carry out sequentially. Since the die set structure in which the mold is installed is also increased in size, the primary molding process and the main molding (forging) process cannot be arranged in the same press.
[0007]
  In view of the above situation, the present invention has a portion having a small-diameter portion and a cross-sectional area perpendicular to one end or both ends in the axial direction larger than that of the thin-diameter portion, and a projection plane of the cross-section including the projection of the cross-section of the small-diameter portion. A method for producing a forged product capable of producing a forged product by a method with high productivity without reducing the material yield., ForgingMold makingAnd forging product manufacturing equipmentThe purpose is to provide.
[0008]
[Means for Solving the Problems]
  The inventor has conducted intensive research on the relationship between the forging process and the product shape, and has completed the present invention based on the findings.
  1) A first invention for solving the above-described problem is that the narrow-diameter portion and the cross-sectional area perpendicular to one end or both ends in the axial direction are larger than the thin-diameter portion and the cross-section of the thin-diameter portion is projected onto the projection surface of the cross-section. In a method for manufacturing a forged product having a part containing a bar, a bar is arranged in a part corresponding to a narrow part formed by an upper mold and a lower mold, using a bar having a diameter smaller than that of the narrow part as a material. After that, the upper mold and the lower mold are brought into contact with each other and pressurized so that the mold does not open, and the bar can move freely in the mold when the upper mold and the lower mold come into contact with each other. As a clearance between the portion corresponding to the small-diameter portion and the outer diameter of the bar, 0.2 to 30% of the outer diameter of the bar is secured, and then a through hole provided in the upper mold and / or the lower mold While being fitted to the mold, the punch is advanced in the direction of the bar disposed in the mold space and advanced in the direction of the bar. A forging product characterized in that a molding position is determined by a punch, and a portion having a vertical cross-sectional area larger than that of the small-diameter portion and a projection of the cross-section of the small-diameter portion and a small-diameter portion are formed on the projection surface of the cross-section. It is a manufacturing method.
  2) A second invention for solving the above-mentioned problem is the manufacturing method according to 1), characterized in that a recess is formed in a portion where the vertical cross-sectional area is larger than the small diameter portion.
  3) A third invention for solving the above-described problems is the method for producing a forged product according to 1) or 2), wherein the narrow-diameter portion is upset.
  4) A fourth invention for solving the above-mentioned problems is that the cross-sectional area perpendicular to one end or both ends in the axial direction of the small-diameter portion is larger than that of the small-diameter portion, and the projection of the cross-section of the small-diameter portion is projected on the cross-sectional projection plane. In a forging die used in a method for producing a forged product having a portion containing slag, a combination of an upper die and a lower die that form a portion corresponding to a small diameter portion having a diameter larger than that of a bar material as a material when contacted The mold and the vertical cross-sectional area that follows the portion corresponding to the small diameter portion are larger than the small diameter portion, and the projection surface of the cross section includes the projection of the cross section of the small diameter portion. A horizontal hole penetrating into the space from the outside of the mold in the longitudinal direction of the bar to be disposed, and a horizontal punch having means for proceeding toward the bar in the space in the mold while fitting in the horizontal hole When the upper mold and the lower mold are in contact, the bar can move freely in the mold. In this state, 0.2% to 30% of the outer diameter of the bar is secured as the clearance between the portion corresponding to the small diameter portion and the outer diameter of the bar, and the molding position is determined by the horizontal punch that proceeds in the bar direction. This is a forging die characterized by that.
  5) A fifth invention for solving the above-mentioned problems is that the cross-sectional area perpendicular to one end or both ends in the axial direction of the small-diameter portion is larger than that of the small-diameter portion, and the projection of the cross-section of the small-diameter portion on the cross-sectional projection plane In the forging die used in the method for producing a forged product having a portion containing, a portion corresponding to a small diameter portion having a larger diameter than a rod as a raw material is formed, and the rod is disposed and the portion corresponding to the small diameter portion Combination of upper and lower molds with clearance between the outer diameter of the bar and 0.2% to 30% of the outer diameter of the bar, and cushion function for the upper and / or lower mold And a vertical cross-sectional area formed by the upper mold and the lower mold is larger than that of the small-diameter portion, and the projection surface of the cross-section includes the projection of the cross-section of the small-diameter portion. And penetrates into a hole that penetrates into the space from outside the mold. Counter punch attached to the holder, and the counter punch enters the mold through a relatively penetrating hole when the cushion function part shrinks in a state where the upper mold and the lower mold are in contact with each other. It is a forging die characterized by
  6) A sixth invention for solving the above-mentioned problems is a step of producing a primary molded product using the mold according to 4) or 5) as a primary molding die, and the primary molded product is used as a final molding die. The process of forging and forming the burrs of the forged product with burrs forged by the above-mentioned finish forming mold and trimming the burrs of the forged product with the deburring mold to produce the forged product, and the small diameter portion and its A forged product manufacturing method for manufacturing a forged product having a portion in which a cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the small-diameter portion and the projection of the cross-section includes the projection of the cross-section of the small-diameter portion.
  7) The seventh invention for solving the above-mentioned problems isForged product manufacturing equipment for manufacturing forged products LeaveThe single press machine according to claim 4 or 5 as a primary molding die.ForgingMold,Forging a primary molded product manufactured with the primary moldFinishing mold,And trimming the burrs of the forged products with burrs that are forged by the mold for finishing molding to make the forged productsDeburring moldButArrangementForged product manufacturing apparatus characterized by being configuredIt is.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 2 shows an example of a schematic sketch relating to the forged product of the present invention. The forged product has a small-diameter portion (1) and a portion (2a, 2b) in which the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the small-diameter portion, ). As a part where the vertical cross-sectional area is larger than the small-diameter portion and the projection surface of the cross-section includes the projection of the cross-section of the small-diameter portion, for example, the cross-sectional shape is circular and the center line is coaxial with the center of the cross-section of the small-diameter portion The cross-sectional shape is polygonal and the center line is coaxial with the center of the small-diameter section.The end cross-section is circular and the center line is not coaxial with the center of the detailed cross-section. That are connected together, or a combination of these.
[0010]
The forged product of the present invention can also be used as a primary molded product when manufacturing a forged product having a portion having a larger volume than the main shaft at both ends of the main shaft, which is a small diameter portion such as a connecting rod, a bicycle crank, and a suspension link. it can. In this case, the main shaft of the connecting rod, bicycle crank, suspension link and the volume of the small diameter portion of the primary molded product are substantially matched. For example, in the case of the connecting rod, each of the piston pin connecting portion and the crankshaft connecting portion at both ends of the main shaft. And the volume of the portion where the vertical cross-sectional area at both ends of the small-diameter portion of the primary molded product is larger than that of the thin-diameter portion and the projection of the cross-section of the thin-diameter portion is included in the projection plane of the cross-section. By doing so, it can be expected that the load on the mold is reduced when the primary molded product is finally molded and the mold life is extended, and the amount of burrs is small, so that the material yield is also preferable.
[0011]
When used as a primary forging product for forging, it is preferable that the volume of the recess provided in the main shaft, the large diameter portion, and the large diameter portion is designed based on the shape of a product to be finally formed. For example, in the case of a connecting rod, the volume of the main shaft portion, which is a small diameter portion, is designed to have an outer diameter that is 1.05 to 1.5 times the volume of the main shaft portion of the product to be formed. The volume of the thick diameter portion, that is, the connecting portion to the piston pin, which is a portion having a cross-sectional area larger than that of the small diameter portion, is designed to be 1.05 to 1.5 times the volume of the product. Further, it is designed such that a recess corresponding to a recess for a pin hole that is opened by machining after the main molding is added to the central portion of the thick diameter portion. This is because the plastic working rate of the completed piston pin portion is increased in the primary molded product by designing in this way, so that the material elongation characteristic, which is one of the mechanical characteristics, is increased, which is preferable. With respect to the main shaft portion, the plastic working rate is further increased and the elongation is increased by a deburring and forging process performed following the primary forming. The main shaft portion, which is the small diameter portion of the primary molded product, is preferably 1.05 times or more the volume of the main shaft portion of the product, because the elongation of mechanical properties is improved by the deburring and forging process of the main molding. If the main shaft portion, which is a small diameter portion, has a volume exceeding 1.5 times the main shaft portion of the product, the material yield is poor, which is not preferable.
[0012]
In the process of making the forged product of the present invention as a primary molded product and then producing the product by deburring and forging, the volume balance of the primary molded product is made similar to that of the subsequent deburring and forging product, so the material yield is good, and The burden is light and a product with no metal unfilled parts can be obtained. In particular, the material yield of the main shaft portion was greatly improved from the conventional yield of 60 to 70%, to 80 to 95%. Furthermore, since the forging stroke is short and good production efficiency (for example, longitudinal forging ratio 200%) can be obtained, it is preferable.
[0013]
FIG. 1 shows a method for producing a forged product having a small diameter portion and a portion in which the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the small diameter portion and the projection of the cross section is included in the projection surface of the cross section. In the mold used for
A combination mold of an upper mold and a lower mold that form a portion corresponding to a small diameter portion having a diameter larger than that of the material, and a vertical cross-sectional area formed by the upper mold and the lower mold is larger than the small diameter section and A horizontal hole penetrating into the space from the outside of the mold in the longitudinal direction of the rod-shaped material disposed in the mold is provided in a portion where the projection of the small diameter section is included in the projection plane of the cross section, and the horizontal hole An example of a forging die characterized by having a horizontal punch having means for proceeding toward the material of the space in the die while being fitted is shown.
[0014]
This will be described in detail with reference to FIG.
The upper die (30), the lower die (28), the cam slider (25a, 25b), and the cam push-down rod (23a, 23b) attached to the upper bolster (21) and the lower bolster (27). The hydraulic cylinder (32), the die holders (22, 26), and the horizontal punches (24a, 24b) having a mechanism for entering from a direction perpendicular to the main molding direction are configured.
[0015]
Knockout pins (31, 29) are arranged in the upper die and the lower die so that the primary molded product for forging that has been formed can be discharged out of the die.
[0016]
The portions corresponding to the narrow diameter portions (36a, 36b) are formed by being surrounded by an upper mold and a lower mold. The shape may be a columnar shape, a prismatic shape, a truncated cone shape, a prismatic trapezoidal shape, or the like. The portion corresponding to the small diameter portion (36a, 36b) formed by the upper die and the lower die forms a space having the same diameter as the narrow portion of the forged product. The portion corresponding to the small diameter portion (36a, 36b) formed by the upper die and the lower die forms a space having a larger diameter than the material. In the mold of the present invention, a rod material having a diameter smaller than that of the narrow diameter portion is used as a material, and the rod-shaped material (35) is arranged at a portion corresponding to the small diameter portion of the lower mold.
[0017]
Subsequent to the narrow-diameter equivalent portions (36a, 36b), a space (37a, 36a, 36b) in which a vertical cross-sectional area is larger than that of the narrow-diameter portion and a portion of the cross-sectional projection plane includes the projection of the narrow-diameter section. 37b, 37c, 37d). The shape of this space can be determined according to the shape of the forged product. For example, it can be a cylindrical shape, a quadrangular prism shape, or an elliptical prism shape. Further, the shape of the portion connected to the portion corresponding to the small diameter portion (36a, 36b) can be arbitrarily designed according to the shape of the forged product.
[0018]
The horizontal holes (34a, 34b, 34c, 34d) are formed by being surrounded by an upper mold and a lower mold. The horizontal holes (34a, 34b, 34c, 34d) are rod-like shapes that are arranged in the mold in a region where the vertical cross-sectional area is larger than that of the small-diameter portion and the projection of the cross-section is included in the projection plane of the cross-section. It is provided so as to penetrate into the space from the outside of the mold in the longitudinal direction of the material.
[0019]
A convex part that forms a dent can be added to a portion where the vertical cross-sectional area forming the large-diameter portion is larger than that of the small-diameter portion and the projection of the cross-section is included in the projection surface of the cross-section, and this example In this case, the upper mold and the lower mold are provided with projections (38a, 38b, 38c, 38d). The dent can be drilled by arbitrarily selecting the position, number, orientation, shape, and depth according to the shape of the final product. In that case, for example, the protrusions forming the recesses are arranged at positions where the protrusions of the upper mold and the lower mold are opposed to each other, and the bottom of the recess of the large diameter part is thinned by forging. Alternatively, the convex portion may be disposed on only one of the upper mold and the lower mold.
[0020]
Since the narrow diameter portion (36a, 36b) forms a space having a diameter larger than that of the material, even if the upper die and the lower die are brought into contact with each other, the material is not processed plastically. The mold can be moved freely. As a result, even if the positioning at the time of starting the material is shifted, the punch is advanced in the direction of the material arranged in the space from the outside to the space surrounded by the upper die and the lower die. The plastic working is started. As a result, for example, when the subsequent processes are processed together in a single press machine, the material can be easily conveyed.
[0021]
Since the portion corresponding to the narrow diameter portion (36a, 36b) forms a space having a larger diameter than the material, the direction of the material disposed in the space from the outside in the space surrounded by the upper die and the lower die When the punch is advanced and formed, the material is upset at the small diameter portion. As a result, it is preferable because a sufficient processing rate can be obtained to obtain a desired mechanical strength without deburring. Since the upsetting process is performed, when the continuous cast bar is used as a raw material, the characteristics of the radial structure can be utilized from the center of the cross section of the continuous cast bar.
[0022]
A cam slider (25a, 25b) method is employed as an example of means for advancing the horizontal punch back and forth in the direction orthogonal to the main molding direction toward the material in the space in the mold. This movement will be described. The upper mold is fixed with a space between the upper pressure receiving plate and the position pressed down by the hydraulic cylinder (32) fixed to the upper pressure receiving plate (33) with the outer diameter constrained by the upper mold holder (22). Has been. Cam push-down bars (23a, 23b) arranged outside the upper mold are lowered in the press operation direction (main molding direction) and come into contact with the cam slider inclined surfaces (39a, 39b). Slopes (40a, 40b) are also added to the cam push-down bar. As a result, the cam slider moves laterally on the table. A lateral punch (24a, 24b) is provided at the tip of the cam slider, and the mold space is closed by being guided by lateral holes (34a, 34b, 34c, 34d) provided in the lower mold and the upper mold. Inserted into. The horizontal punch pressurizes a small diameter material and causes the material to plastically flow and fill the large diameter portion of the primary forging product. A spring (41a, 41b) is provided between the cam slider and the lower die, and is pushed back to the standby position by the reaction force of the spring.
[0023]
Next, the molding operation of this mold will be described with reference to FIGS.
The upper mold moves downward toward the lower mold by the main molding operation. The lowered upper mold comes into contact with the lower mold. FIG. 3 shows a state in which the upper mold and the lower mold are in contact with each other. That is, the surfaces of the mold (the front and back mold surfaces in FIG. 3) other than the space in the mold where the material is arranged are in contact. Since a rod having a diameter smaller than that of the small diameter portion is used as the material, the material (35) is thinner than the portion corresponding to the mold small diameter portion at this point, and thus the material has not undergone plastic working. The upper mold continues to descend further, the hydraulic cylinder shrinks through the upper mold, the cam push bar contacts the cam slider slope, and the horizontal punch is pressed so that the mold does not contact and open Moves the through-hole formed by the upper mold and the lower mold to upset the material. The horizontal punch may stand by in a state where it is placed on the surface of the through hole formed in the lower mold, or may stand by outside the through hole. FIG. 4 shows a state in which the press machine is at the bottom dead center, and shows a state in which the horizontal punching has been completed and product molding has been completed.
[0024]
The material is upset at the small diameter portion, and further, the portion having a cross-sectional area larger than the small diameter portion and a cross section including the diameter of the small diameter portion is filled to complete the molding.
The product is lifted by a knockout pin and discharged out of the system from the mold.
[0025]
FIG. 5 shows another example of the mold according to the present invention.
Mold for use in a method for manufacturing a forged product having a narrow diameter portion and a portion where the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the narrow diameter portion and the projection of the cross section is included in the projection surface of the cross section In
A combination mold of an upper mold and a lower mold that form a portion corresponding to a small-diameter portion having a diameter larger than that of the material, a holder for mounting the upper mold and / or the lower mold via the cushion function section, The vertical cross-sectional area formed by the mold and the lower mold is larger than the small-diameter portion, and penetrates into the space from the outside of the die provided in the portion where the projection of the cross-section of the small-diameter portion is included in the projection plane of the cross-section An example of a forging die having a counter punch attached to a holder so as to enter a hole to be formed is shown.
[0026]
Examples of the cushion function portion of the mechanism that generates the cushion function include a hydraulic cylinder, a gas cylinder, and a spring.
[0027]
In FIG. 5, the upper die and the lower die are provided with a hydraulic cylinder and a counter punch mechanism, but it is also possible to provide them only in either die. It is also possible to provide a plurality of molds in one mold.
[0028]
This will be described in detail with reference to FIG.
The upper mold (55) is constrained in the outer diameter by the upper mold holder (54), and is pushed down by a hydraulic cylinder (51a) arranged on the upper mold upper part, and between the pressure receiving plate (53). There is space. The counter punches (57a, 57b) are fixed to the pressure receiving plate and are fitted with through holes (63a, 63b) provided in the upper mold. The hydraulic cylinder is also fixed to the pressure plate.
[0029]
The lower mold (60) has an outer diameter constrained by the lower mold holder (56), and is pushed up by a hydraulic cylinder (51b) disposed at the lower part of the lower mold, and is located between the pressure receiving plate (59) and the lower mold (60). There is space. The counter punches (57c, 57d) are fixed to the pressure receiving plate and are fitted into holes (65a, 65b) provided in the lower mold. The hydraulic cylinder is also fixed to the pressure plate.
[0030]
Knockout pins (61, 62) are arranged in the upper die and the lower die so that the primary molded product for forging that has been formed can be discharged out of the die.
[0031]
These components are attached to the upper bolster (52) and the lower bolster (58).
[0032]
In the metal mold of the present invention, a bar material having a diameter smaller than that of the small diameter part is used as a raw material, and the bar-shaped material (64) is arranged in a portion corresponding to the small diameter part of the lower mold.
[0033]
The portions corresponding to the narrow diameter portions (66a, 66b) are formed by being surrounded by an upper mold and a lower mold. The shape may be a columnar shape, a prismatic shape, a truncated cone shape, a prismatic trapezoidal shape, or the like. The portion corresponding to the narrow diameter portion (66a, 66b) formed by the upper die and the lower die forms a space having the same diameter as the narrow portion of the forged product. The portion corresponding to the small diameter portion (66a, 66b) formed by the upper die and the lower die forms a space having a larger diameter than the material.
[0034]
Following the narrow diameter portion (66a, 66b), a space (67) in which a vertical cross-sectional area is larger than that of the narrow diameter portion and a portion where the projection of the narrow diameter section is included in the projection plane of the cross section Is provided. The shape of this space can be determined according to the forged product, and can be, for example, a cylindrical shape, a quadrangular prism shape, or an elliptical prism shape. Further, the shape of the portion connected to the portion corresponding to the small diameter portion (36) can be arbitrarily designed according to the shape of the forged product.
[0035]
Next, the molding operation of this mold will be described with reference to FIGS.
The material (64) is introduced into the portion corresponding to the small diameter portion of the lower mold. The upper mold is lowered toward the lower mold by the main molding operation of the forging machine. FIG. 6 shows a state where the upper mold and the lower mold are in contact with each other. In a state where the upper mold lower surface and the lower mold upper surface are in contact with each other, pressure is applied so that the mold is not opened by the pressure of the hydraulic cylinder. At this time, since the material is thinner than the small-diameter portion of the mold, the material has not undergone plastic working.
[0036]
Since the main molding force is greater than the pressure of the hydraulic cylinder, the hydraulic cylinder contracts with the upper mold and the lower mold in contact with each other, and counter punches fixed to the pressure plate are provided on the upper mold and the lower mold. While entering the holes (63a, 63b, 65a, 65b), they relatively enter the mold from the through holes. With the counter punch, the material is upset to fill the small diameter portion, and the metal is filled into a portion having a cross-sectional area larger than the small diameter portion and a cross section including the diameter of the small diameter portion, thereby completing the forming.
[0037]
The product is removed from the mold by the knockout pin provided in the upper mold and the lower mold, and discharged from the mold.
[0038]
Since the counter punch is used, the punch can be entered from above and below, and as a result, a deep concave shape can be added, which is preferable.
[0039]
In the mold of the present invention, the clearance between the portion corresponding to the small diameter portion and the outer diameter of the bar is 0.2% to 30% (more preferably 0.5% to 10%) of the outer diameter of the bar. Preferably there is. For example, when it has a diameter of 20 to 500 mm, the clearance is preferably 0.04 to 150 mm (more preferably 0.1 to 50 mm). Since the material can be moved in the longitudinal direction of the material even after the mold comes into contact, the material position can be determined by the horizontal punch, and therefore positioning in the longitudinal direction of the material is unnecessary and preferable. A clearance of 0.2% or more is preferable because the movement of the material in the longitudinal direction is good. If the clearance exceeds 30%, the material may buckle during molding, which may cause forging defects such as entrainment.
[0040]
The ratio between the outer diameter of the bar and the length of the small diameter part of the mold, the temperature conditions during the forging of the material (cold, warm), the mechanical properties of the bar at that time, the conditions that do not cause buckling, The clearance can be set within this range.
[0041]
The clearance is an average value of the gap between the portion corresponding to the small diameter portion and the outer diameter of the bar.
[0042]
Using the mold of the present invention, the narrow portion and the cross-sectional area perpendicular to one end or both ends in the axial direction are larger than the narrow portion, and the projection plane of the cross section includes the projection of the cross section of the narrow portion Forging product manufacturing method
Using a bar material with a diameter smaller than the small diameter part as a raw material, after placing the bar material in the part corresponding to the narrow diameter part formed by the upper mold and the lower mold, the upper mold and the lower mold are brought into contact with each other. After pressurizing so that the mold does not open, the punch proceeds in the direction of the bar placed in the mold space while fitting into the through hole provided in the upper mold and / or the lower mold Thus, the forged product manufacturing method is characterized in that a vertical cross-sectional area is larger than that of the small-diameter portion, and a portion including the projection of the cross-section of the small-diameter portion and a small-diameter portion are formed on the projection plane of the cross-section.
[0043]
In the manufacturing method of the present invention, the raw material is plastically deformed and flowed from a state in which the upper die and the lower die are not opened in a completely closed state, and a thin rod material is formed from a direction perpendicular to the longitudinal direction of the material. Therefore, it is possible to reduce the material yield of a forged product having a small-diameter portion and a cross-sectional area perpendicular to one end or both ends in the axial direction larger than that of the thin-diameter portion and the projection plane of the cross-section includes a projection of the cross-section of the small-diameter portion Without making it, it becomes a manufacturing method with high productivity.
[0044]
The manufacturing method of the present invention uses a bar material having a diameter smaller than that of the small diameter part as a raw material, and the bar material is placed in a portion corresponding to the small diameter part where the space surrounding the small diameter part is formed by the upper mold and the lower mold. After placement, the upper mold and the lower mold are brought into contact with each other, and after pressurizing so that the mold does not open, the punch is advanced, so that the material is plastically deformed and flowed in a state where there is a gap between the molds. Since the plastic deformation flow occurs from the state in which the upper mold and the lower mold are completely closed, complete closed forging is performed, and burrs are not generated on the outer peripheral portion of the product, so that the material yield is good.
[0045]
In the manufacturing method using the mold according to the present invention, since the material is placed in the horizontal direction, the arrangement of the material is stable, and the forming position is determined by the punch moving in the material direction. It is not necessary to strictly manage the relationship with the center position of the. Since the raw material moves and is corrected to the position required for the forged product with the movement of the punch, it is preferable because the material positioning accuracy in the longitudinal direction is not required. Since upsetting is performed after pressurizing so that the mold does not contact and open, burrs are not generated on the outer periphery of the product, which is preferable.
[0046]
In the production method of the present invention, by using the mold of the present invention, a dent can be preferably formed at a site where the vertical cross-sectional area is larger than the small diameter portion.
[0047]
In the production method of the present invention, by using the mold of the present invention, the small-diameter portion can be placed and preferably molded.
[0048]
By installing the above-described components (hydraulic cylinder, cam slider, lateral punch, counter punch, etc.) on a conventional mold, the mold structure of the present invention can be configured. As a result, a compact mold configuration is possible, and production equipment is inexpensive, which is preferable.
[0049]
In the present invention, for example, when a forged product is a part that is exposed to a high load at a high temperature such as a connecting rod, for example, an Al-Cu-based aluminum alloy such as A2014, A2017, and A2618 is excellent in high-temperature strength in a forged product. This material is preferable. For example, Al-Mg-Si-based aluminum alloys such as A6061 and A6082 are used as a raw material, and have a medium strength and excellent toughness and corrosion resistance in forged products. It is preferable as a material when the parts to be manufactured are forged products.
[0050]
For example, an aluminum alloy containing Cu and Si is preferable in order to obtain high temperature strength and wear resistance required for the connecting rod. It is preferable to use an aluminum alloy containing Al-5 to 20 mass% Si-1 to 7 mass% Cu-0.1 to 1.0 mass% Mg as a raw material. Forged products are preferred because they are excellent in high-temperature strength and wear resistance. Since it is an aluminum alloy, its density is lower than that of iron parts, which is preferable because it can be lightened. If Si is less than 5%, sufficient wear resistance cannot be obtained, and if it exceeds 20%, strength reduction due to an excessive number of primary crystal silicon particles is expected. If Cu is less than 1%, sufficient strength cannot be obtained. If it exceeds 7%, a coarse intermetallic compound is formed, which is an undesirable starting point for fatigue failure. If Mg is less than 0.1%, sufficient strength cannot be obtained. If it exceeds 1.0%, the effect is not exhibited and the amount becomes excessive.
[0051]
In the mold according to the present invention, the mold structure is a mold obtained by dividing the forged product forming portion in the vertical direction on the plane including the axis in the longitudinal direction, so that the degree of freedom in designing the mold is increased. As a result, in the mold, it is not necessary to match the center line of the portion where the cross-sectional area perpendicular to the small diameter portion is larger than that of the small diameter portion and the projection of the cross section includes the projection of the cross section of the small diameter portion. As a result, the final product shape is used when the cross-sectional area perpendicular to the small-diameter portion is larger than that of the small-diameter portion, and the center of gravity line does not coincide with the portion where the projection of the cross-section of the small-diameter portion is included in the projection plane of the cross-section. Product can be molded.
[0052]
FIG. 11 shows an axial center of gravity line of a portion where the cross-sectional area perpendicular to the axial center line (131) of the small-diameter portion is larger than that of the thin-diameter portion and the projection of the cross-section is included in the projection plane of the cross-section. An example of a forged product is shown in which (132a, 132b) is not collinear.
[0053]
A forged product having such a shape can be manufactured using the mold and the manufacturing method of the present invention. The center line corresponding to the molding of the small-diameter portion formed by the upper die and the lower die is shifted in the front-rear direction from the center of gravity line of the portion that is larger than the small-diameter portion and the projection of the cross-section includes the projection of the thin-diameter section. By using the molds arranged in the same manner, it is possible to manufacture products that are not on the same straight line.
[0054]
Since the center line of the forged product and the center line of the cross section including the diameter of the small diameter portion and the cross section including the diameter of the small diameter portion are not collinear, the cross sectional area larger than the center line of the small diameter portion and the small diameter portion It is preferable as a preformed product of a forged product in which the center of gravity line of the cross section including the small diameter portion is not collinear.
[0055]
When using a conventional forging roll, the material is sandwiched between upper and lower rolls and the center part is squeezed to form, so the center line of the large diameter part that does not squeeze matches the center line of the narrow diameter part that is squeezed. Become. Therefore, it is impossible to form an eccentric forged product. On the other hand, in burr out forging, it is possible to mold by using a die engraved with an eccentric forged product shape whose center line does not match, but it generates burrs on the outer periphery of the product, resulting in poor material yield and Such a burden is large and impractical.
[0056]
The forging method of the present invention is preferable because an eccentric forged product having no burr can be easily formed.
[0057]
In addition, when using a forged product of the present invention that is eccentric as a primary molded product to form an eccentric forged product by finish forging, the yield of the material is good, and the load during forging of the finished mold is small. This is preferable because the mold life is extended.
[0058]
FIG. 2 shows that the vertical cross-sectional area is larger than that of the small-diameter portion, and the portion where the projection of the cross-section of the small-diameter portion is included in the projection surface of the cross-section is larger than the other, and the shape of the concave portion is accordingly larger. An example of a molded forged product is shown. These portions may be different from each other, or may be the same, and are matched to a forged shape for obtaining a final product shape.
[0059]
A forged product having such a shape can be manufactured using the mold and the manufacturing method of the present invention. Protrusions (convex portions) that are larger than the narrow diameter portions of the upper mold and the lower mold and that correspond to the depressions of the product are provided in the portions where the projection of the cross section of the small diameter portion is included in the projection plane of the cross section. By using the mold, it is possible to manufacture a forged product that has a dent in a portion that is larger than the small-diameter portion and includes a projection of the cross-section of the small-diameter portion on the projection plane of the cross-section. The protrusion can be provided in accordance with a desired shape of the recess. For example, in the mold shown in FIG. 1, reference numerals 38a, 38b, 38c, and 38d are the protrusions.
[0060]
The counter punch can be a protrusion. By pressing the counter punch, it is possible to form a dent in a portion that is larger than the small diameter portion and includes a projection of the cross section of the small diameter portion on the projection surface of the cross section. For example, in the mold shown in FIG. 5, reference numerals 57a, 57b, 57c and 57d are the counter punches. The recess formed by the counter punch is preferable because it can be formed deeply.
[0061]
When a product having a dent is used as a primary molded product, a dent is added in the primary molded product according to the size of the dent in the molded product shape when forging a product having a dent in the subsequent main molding. This is preferable because the material yield can be improved and the load applied to the mold can be reduced.
[0062]
By using this product as a primary molded product, for example, the piston pin connection hole of the connecting rod becomes a part where a dent is added in the primary molded product, so that the amount of burrs generated in this molding can be reduced, and the material yield is improved. Moreover, the burden of the mold convex part which is a piston pin connection part hole shaping | molding part of this shaping | molding die can be made small.
[0063]
Next, a method for producing a forged product when the forged product of the present invention is used as a primary molded product will be described.
Place one of the above-mentioned molds as the primary molding mold, finish molding mold, deburring mold,
By sequentially feeding the process of manufacturing a primary molded product with a mold for primary molding, the process of forging a primary molded product with a mold for final molding, and the process of trimming the generated burr to make a forged product
A forged product having a small diameter portion and a portion where the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than that of the small diameter portion and the projection of the cross section of the small diameter portion is included in the projection plane of the cross section is manufactured. It is preferable that the molds are arranged in parallel because the conveying device is easy.
[0064]
It is preferable to arrange the molds in a single press. This is because the device can be made compact to increase production efficiency. In addition, it is preferable to arrange them in a single apparatus because the material conveyance time is shortened, so that the material can be efficiently heated.
[0065]
  Used in manufacturing methodForged product manufacturingThe apparatus will be described with reference to FIG. In a single press machine (121), a primary molding die (122a, 122b), a finishing molding die (123a, 123b), and a deburring die (trimming die) (124a, 124b) are arranged. It is. The arrangement is preferably arranged in parallel in the order of a primary molding die, a finishing molding die, and a deburring die. Any of the above-described molds of the present invention is used as the primary molding mold. Means (not shown) for conveying a workpiece between the molds is provided. As a means for conveying, for example, a conveying machine or a robot having a work bar on the feed bar can be used. By feeding means, the thin rod material is put into the primary molding die, the primary molded product after the primary molding is completed is sent to the main molding die, and the burred product after the final molding is sent to the deburring die. The product from which burrs are removed is discharged from the deburring mold.
[0066]
Next, the operation will be described. The shape of the product obtained by molding and processing in each step is shown corresponding to each mold in FIG.
[0067]
In the primary molding die, primary molding having a narrow diameter portion and a portion where the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than the narrow diameter portion and the projection of the cross section is included in the projection plane of the cross section. The product (125) is made of a bar material having a diameter smaller than that of the small diameter part, and the bar material is arranged in a portion corresponding to the small diameter part in which the space surrounding the small diameter part is formed by the upper mold and the lower mold. Then, the upper mold and the lower mold are brought into contact with each other, pressed so that the mold does not open, and then fitted into a through hole provided in the upper mold and / or the lower mold, The punch is advanced in the direction of the material placed in the space from the outside in the space surrounded by the mold, the vertical cross-sectional area is larger than the small diameter part, and the projection of the cross section of the small diameter part is included in the projection plane of the cross section The part and small-diameter portion to be formed are upset.
[0068]
The formed primary molded product becomes a forged product (126) with burrs by a finish forging die. The forged product with burrs is deburred (128) by a trimming die to become a forged product (127).
[0069]
The material can be heated, for example, by first heating to 400 to 450 ° C. to form two steps. Or it can heat between processes as needed. The mold temperature is preferably heated to about 250 ° C to 400 ° C. The trimming mold does not necessarily require heating. The lubricant is preferably applied by spraying an oily graphite lubricant with a fixed spray.
[0070]
Since these molds are arranged, it is preferable because a manufacturing method with high productivity is achieved by sequential processes. Since it is a horizontally placed mold, the press stroke is shorter than that for vertical forging, so the production tact time is short and the productivity can be increased, which is preferable. High-productivity by enabling continuous press operation (no waiting time at top dead center and starting the next cycle upon completion of one cycle) by using an automatic transfer device as the means for carrying out sequential feeding. Sequential processes can be automatically operated, which is preferable in terms of labor saving.
[0071]
In each of the manufacturing methods of the present invention described above, it is preferable to use a material manufactured by thin continuous casting as a raw material. Continuous casting rods have a high solidification rate and a solidified structure from the outer diameter of the material toward the center. Therefore, compared to extruded rods with a fibrous structure, transition metal elements are finely dispersed, making recrystallization difficult. Good mechanical properties and excellent high-temperature strength.
[0072]
Further, the main shaft having a high load is preferably a fibrous structure in order to increase the strength. By performing burring forging in the forging main forming, a metal flow in the direction of burring is obtained, and the elongation characteristics of the mechanical characteristics are improved, so that a product with a good balance between product strength and toughness can be obtained. If there is no need to improve the strength due to the fiber structure depending on the application, closed forging can be used instead of deburring forging. This is preferable because the amount of burrs generated can be reduced.
[0073]
It is preferable to use an oily graphite lubricant as the forging lubricant. This is because even when the mold temperature is high, a uniform film can be formed on the mold surface and can be applied over a wide range in a short time by applying it in a spray form.
[0074]
In each of the manufacturing methods of the present invention described above, the following heat treatment is preferably performed.
The forging material is preheated before forging. The temperature condition of the preheating treatment is in the range of 350 ° C. to (solid phase temperature of aluminum alloy−10) ° C. The processing time is set until the temperature of the entire forging material reaches the preheating temperature range, and then the forging process is started. If it is less than 350 ° C., sufficient plastic flow cannot be obtained when the forging material is hot forged, and if it exceeds (solid phase temperature of aluminum alloy −10) ° C., burning (local melting) may occur in the forging material. There is. Burning is not preferable because the strength of the forged product is severely deteriorated or the product has defects due to local dissolution such as bulges and micro-shrinkage.
[0075]
Since forging is usually performed hot, not only preheating the material but also the mold is heated. The heating temperature can be 100 to 400 ° C. The heating temperature is selected according to the shape to be forged, the type of forging equipment, the type of alloy used, and other forging factors. If the temperature is too low, heat removal from the material increases, resulting in poor workability and insufficient plastic flow of the material. If the temperature is too high, the strength of the mold is reduced, and damage such as wear and chipping tends to occur, which is not preferable from the viewpoint of the mold life. Forging is preferably carried out after applying a lubricant to the mold.
[0076]
The forged product obtained by forging can be used as it is, but in the case of an alloy to which Cu, Mg, Zn, Sc, Ag, etc. are added, the mechanical properties of the material are improved by heat treatment. It is preferable to apply the treatment. The artificial aging treatment includes, for example, a solution treatment treatment in which a forged product is immersed in water immediately after a heating temperature of 400 to 550 ° C. and a holding time of 0.2 to 10 hours, and then at 0 to 120 to 250 ° C. It is preferable to perform tempering for 2 to 20 hours. Further, the tempering process may be performed in several stages by changing the temperature condition. Thereby, mechanical properties (for example, tensile strength, 0.2% proof stress, elongation) and fatigue strength can be enhanced including hardness.
[0077]
Before subjecting to hot forging, in order to further improve the forgeability and the artificial aging treatment property after forging, it is preferable to homogenize the material. Homogenization treatment is a heat treatment of the microsegregated state that occurs during casting of added metals such as Cu and Mg that are added to increase the mechanical strength of forged products and the strength when used at high temperatures. , Disperse uniformly in the aluminum base. Thereby, the workability at the time of forging and the uniformity of the mechanical characteristics after the artificial aging treatment in the subsequent process can be ensured. Examples of the conditions for the homogenization treatment include a temperature range of 400 ° C. to (solid phase temperature of alloy to be used−10) ° C., and a holding time of 1 to 30 hours.
[0078]
On the other hand, depending on the alloy components used or the shape of the forged product, it is possible to obtain the same effect as the homogenization process using preheating to the material applied before forging. An effect equivalent to the homogenization treatment of the material can be obtained by lengthening the holding time of the previous preheating step to 1 hour or longer. In addition, depending on the alloy components used or the shape of the forged product, it is possible to obtain the same effect as the homogenization process using a heat treatment process performed after forging. An effect equivalent to the homogenization treatment of the material can be obtained by lengthening the holding time during the treatment.
[0079]
【Example】
[Example 1]
An A2014 aluminum alloy long material having a diameter of 28 mm (28 mm in diameter) was cut into a length of 180 mm by a saw cutting machine to obtain a forging material. A mold having the same configuration as in FIG. 1, the outer diameter of the portion corresponding to the small diameter portion is φ29 mm and the length is 50 mm, and the cylindrical large diameter portion having a diameter of 35 mm and a length of 40 mm is formed on both ends of the corresponding portion of the small diameter portion and 10 mm 2 is connected to the small-diameter portion at a slope of 45 °, and the cross-sectional area perpendicular to one or both ends in the axial direction is larger than the small-diameter portion, and the cross-sectional area is small on the projection plane of the cross-section. A mold engraved with the shape of a forged product having a portion including a partial cross-section projection was prepared. Convex shapes having a length of 20 mm, a width of 20 mm, and a height of 10 mm are added to the large diameter portion in two places on the upper mold and the lower mold. A forged product was forged using the mold under the following production conditions.
[0080]
The material was heated to 420 ° C., and 1 g of an oil-based graphite lubricant was spray applied to the mold. As for the mold temperature, the surface of the molded part was heated to 300 ° C. for both the upper mold and the lower mold.
[0081]
A mold was placed on a 630 t link motion forging machine, and the material was placed at a position corresponding to the small diameter portion and molded. A forged product without burr was obtained.
[0082]
Using the obtained forged product as a primary molded product, a connecting rod molding die was used to forge the connecting rod component for an internal combustion engine shown in FIG. The material temperature was heated to 420 ° C., and 2 g of oil-based graphite lubricant was sprayed on the mold. The mold temperature was heated so that the surface temperature of the molded part was 300 ° C. for both the upper mold and the lower mold.
[0083]
Since burrs were generated on the outer periphery of the forged product, burrs were punched and removed with a deburring die. A good connecting rod forged product excellent in high temperature strength was obtained.
[0084]
[Example 2]
An aluminum alloy long material composed of Al-12 mass% Si-4 mass% Cu-0.5 mass% Mg and other small amount of impurity elements having a diameter of 28 mm was cut into a length of 180 mm by a saw cutting machine to obtain a forging material. . The outer diameter of the small diameter portion is 29 mm and the length is 50 mm in a mold having the same configuration as that in FIG. 1. The cylindrical large diameter portion having a diameter of 35 mm and a length of 40 mm is formed at both ends of the small diameter portion and 45 mm of 10 mm. A mold engraved with a shape as shown in FIG. 2 connected to the small diameter portion on the slope was prepared. Convex shapes having a length of 20 mm, a width of 20 mm, and a height of 10 mm are added to the large diameter portion in two places on the upper mold and the lower mold. A forged product was forged using the mold under the following production conditions.
[0085]
The material was heated to 420 ° C., and 1 g of an oil-based graphite lubricant was spray applied to the mold. As for the mold temperature, the surface of the molded part was heated to 300 ° C. for both the upper mold and the lower mold.
[0086]
A mold was placed on a 630 t link motion forging machine, and the material was placed at a position corresponding to the small diameter portion and molded. A forged product without burr was obtained.
[0087]
Using the obtained forged product as a primary molded product, a connecting rod molding die as shown in FIG. 8 was forged using a connecting rod molding die. The material temperature was heated to 420 ° C., and 2 g of oil-based graphite lubricant was sprayed on the mold. The mold temperature was heated so that the surface temperature of the molded part was 300 ° C. for both the upper mold and the lower mold.
[0088]
Since burrs were generated on the outer periphery of the forged product, burrs were punched and removed with a deburring die. A good connecting rod forged product excellent in wear resistance and high temperature strength was obtained.
[0089]
[Example 3]
A long A6061 aluminum alloy material having a diameter of 32 mm was cut into a length of 180 mm by a saw cutting machine to obtain a forging material. Using a mold having the same configuration as that shown in FIG. 5, the outer diameter of the narrow diameter portion is 35 mm and the length is 80 mm, the cylindrical large diameter portion having a diameter of 35 mm and a length of 30 mm at both ends of the narrow diameter portion, and 45 mm of 10 mm. A mold engraved with a shape as shown in FIG. 2 connected to the small-diameter portion on a slope of ° was prepared. A convex shape having a diameter of 15 mm and a height of 10 mm is added to the upper die and the lower die at two locations in the center in the longitudinal direction of the large diameter portion. A forged product was forged using the mold under the following production conditions.
The material was heated to 420 ° C., and 1 g of an oil-based graphite lubricant was spray applied to the mold. As for the mold temperature, the surface of the molded part was heated to 300 ° C. for both the upper mold and the lower mold.
A mold was placed on a 630 t link motion forging machine, and the material was placed at a position corresponding to the small diameter portion and molded. A good forged product without burrs was obtained.
A suspension link component as shown in FIG. 10 was forged using the resulting forged product as a primary molded product using a suspension link molding die.
[0090]
The material temperature was heated to 460 ° C., and 2 g of an oil-based graphite lubricant was sprayed on the entire mold part. The mold temperature was heated so that the surface temperature of the molded part was 300 ° C. for both the upper mold and the lower mold. Since a burr was formed on the outer periphery of the suspension link, a product was obtained by removing the burr using a deburring die. A good suspension link forged product with excellent corrosion resistance was obtained.
[0091]
【The invention's effect】
The production method of the present invention comprises:
In a manufacturing method of a forged product having a narrow diameter portion and a portion where the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than the narrow diameter portion and the projection of the cross section is included in the projection surface of the cross section, the small diameter Using a bar with a diameter smaller than the part as a raw material, after placing the bar in the part corresponding to the narrow part formed by the upper mold and the lower mold, the mold is brought into contact with the upper mold and the lower mold After pressurizing so as not to open, the punch is advanced in the direction of the bar placed in the mold space while fitting into the through hole provided in the upper mold and / or the lower mold In addition, since the vertical cross-sectional area is larger than the small-diameter portion and the projection surface of the cross-section includes a portion including the projection of the small-diameter cross-section and the thin-diameter portion, the forged product manufacturing method, This is a production method with high productivity without reducing the material yield.
[0092]
Because the load applied to the mold for this molding is small and molding can be performed while suppressing missing or unfilled parts, near net-shaped connecting rod parts, suspension ring parts, bicycle crank parts, etc. It is possible to manufacture with high productivity with improved material yield and reduced man-hours.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a schematic configuration of an example of a forging die according to the present invention.
FIG. 2 is a schematic sketch of an example of the forged product of the present invention.
FIG. 3 is a cross-sectional view of a schematic configuration of an example of a forging die according to the present invention when contacting an upper and lower die.
FIG. 4 is a diagram for explaining a state of a bottom dead center of an example of the forged product of the present invention.
FIG. 5 is a cross-sectional view of a schematic configuration of another example of the forging die of the present invention.
FIG. 6 is a diagram for explaining a state of another example of the forging die according to the present invention when the upper and lower dies are in contact with each other.
FIG. 7 is a diagram for explaining the state of the bottom dead center of another example of the forging die according to the present invention.
FIG. 8 is a schematic sketch of a connecting rod forged product for an internal combustion engine.
FIG. 9 is a schematic sketch of a bicycle crank forged product.
FIG. 10 is a schematic sketch of a suspension link forged product.
FIG. 11 is a schematic cross-sectional view of an example of a forged product of the present invention.
FIG. 12 is used in the production method of the present invention.Forged product manufacturingIt is a schematic sketch of an apparatus.
[Explanation of symbols]
1: Small diameter part
2a, 2b: Sites where the vertical cross-sectional area is larger than that of the small-diameter portion and the projection of the cross-section is included in the cross-sectional projection plane
3a, 3b: dent
22: Dice holder
23a, 23b: cam push-down rod
24a, 24b: Horizontal punch
25a, 25b: Cam slider
30: Upper mold
31: Knockout pin
32: Hydraulic cylinder
34a, 34b, 34c, 34d: side holes
35: Stick-shaped material
36a, 36b: portion corresponding to the small diameter portion
37a, 37b, 37c, 37d: spaces in which a vertical cross-sectional area is larger than that of the small-diameter portion, and a portion where the projection of the cross-section of the small-diameter portion is included in the projection plane of the cross-section
38a, 38b, 38c, 38d: convex portion
39a, 39b: Cam slider slope
40a, 40b: Cam push-down bar slope
41a, 41b: spring
51a, 51b: Hydraulic cylinder
53: Pressure plate
54: Upper mold holder
55: Upper mold
57a, 57b, 57c, 57d: Counter punch
59: Pressure plate
60: Lower mold
63a, 63b: holes provided in the upper mold
65a, 65b: holes provided in the lower mold
66a, 66b: portion corresponding to the narrow diameter
67: A space in which a vertical cross-sectional area is larger than that of the small-diameter portion, and a portion in which the projection of the cross-section of the small-diameter portion is included in the projection plane of the cross-section
121: Forging machine
122a, 122b: mold for primary molding
123a, 123b: Finishing mold
124a, 124b: Deburring mold

Claims (7)

細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法において、
細径部より細い径の棒材を素材として用いて、上金型と下金型により形成される細径部相当部位内に棒材を配置した後、
上金型と下金型を接触させ金型が開かないように加圧させるとともに、その上金型と下金型とが接触したとき棒材は金型内を自由に移動できる状態でその細径部相当部位と棒材の外径とのクリアランスとして棒材の外径の０．２％〜３０％を確保し、
続いて上金型および／または下金型に設けた貫通穴に嵌合しながら、金型の空間内に配置されている棒材の方向にパンチを進行させてその棒材方向に進むパンチにより成形位置を決め、垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位および細径部を成形する、
ことを特徴とする鍛造製品の製造方法。In the method for producing a forged product having a small diameter portion and a cross-sectional area perpendicular to one end or both ends in the axial direction larger than the small diameter portion, and a projection surface of the cross section includes a projection of the cross section of the small diameter portion.
Using a bar material with a diameter smaller than the narrow diameter part as a raw material, after placing the bar material in the part corresponding to the narrow diameter part formed by the upper mold and the lower mold,
Its state bar stock that can move freely inside the mold when Rutotomoni was pressurized to the upper die and the the contacted die lower mold does not open, and the its upper and lower molds in contact As a clearance between the portion corresponding to the small diameter portion and the outer diameter of the bar, 0.2% to 30% of the outer diameter of the bar is secured,
Subsequently , the punch is advanced in the direction of the bar disposed in the mold space while being fitted into the through hole provided in the upper mold and / or the lower mold, and the punch proceeds in the direction of the bar. Determine the molding position, and mold the portion and the small diameter portion where the vertical cross-sectional area is larger than the small diameter portion and the projection of the cross section includes the projection of the small diameter section.
A method for producing a forged product. 垂直な断面積が細径部より大きい部位に凹みを成形することを特徴とする請求項１に記載の鍛造製品の製造方法。  The method for producing a forged product according to claim 1, wherein the dent is formed in a portion where the vertical cross-sectional area is larger than the small diameter portion. 細径部が据え込み成形されることを特徴とする請求項１または２に記載の鍛造製品の製造方法。  The method for producing a forged product according to claim 1 or 2, wherein the narrow-diameter portion is upset. 細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法に用いる鍛造金型において、
接触したときに素材としての棒材より大きい径を有する細径部相当部位を形成する上金型と下金型との組み合わせ金型と、
細径部相当部位に続く垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に設けられていて、かつ、金型内に配置される棒材の長手方向に金型の外から空間内に貫通する横穴と、
その横穴に嵌合しながら金型内の空間の棒材に向かって進行する手段を有する横パンチと、を有し、
上金型と下金型とが接触したとき棒材は金型内を自由に移動できる状態であって細径部相当部位と棒材の外径とのクリアランスとして棒材の外径の０．２％〜３０％が確保され、
棒材方向に進む横パンチにより成形位置が決まる、
ことを特徴とする鍛造金型。 Forging gold used in a method for manufacturing a forged product having a narrow diameter portion and a portion where the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than the narrow diameter portion and the projection of the cross section is included in the projection plane of the cross section In the mold,
A combined mold of an upper mold and a lower mold that form a portion corresponding to a small diameter portion having a larger diameter than a bar as a raw material when contacted;
A rod that is provided in a portion where the vertical cross-sectional area following the portion corresponding to the narrow-diameter portion is larger than that of the thin-diameter portion and the projection of the cross-section includes the projection of the cross-section of the small-diameter portion, and is disposed in the mold A lateral hole penetrating into the space from the outside of the mold in the longitudinal direction of the material ,
It has a transverse punch having a means for traveling toward the bar space in the mold while fitted into the lateral hole, and
When the upper mold and the lower mold are in contact, the bar is in a state where it can freely move in the mold, and the outer diameter of the bar is 0. 0 as the clearance between the portion corresponding to the small diameter portion and the outer diameter of the bar. 2% -30% is secured,
The forming position is determined by the horizontal punch that goes in the bar direction.
A forging die characterized by that. 細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品の製造方法に用いる鍛造金型において、
素材としての棒材より大きい径を有する細径部相当部位を形成するとともに、その棒材が配置され細径部相当部位と棒材の外径とのクリアランスが棒材の外径の０．２％〜３０％となる上金型と下金型との組み合わせ金型と、
上金型および／または下金型をクッション機能部を介して取りつけるホルダーと、
上金型と下金型により形成される垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位に設けられていて、かつ、金型の外から空間内に貫通する穴に侵入するようにホルダーに取りつけたカウンターパンチと、を有し、
上記カウンターパンチは、上金型下金型が接触した状態でクッション機能部が縮むことにより、相対的に貫通する穴から金型内に進入してくる、
ことを特徴とする鍛造金型。 Forging gold used in a method for manufacturing a forged product having a narrow diameter portion and a portion where the cross-sectional area perpendicular to one end or both ends in the axial direction is larger than the narrow diameter portion and the projection of the cross section is included in the projection plane of the cross section In the mold,
A portion corresponding to the small diameter portion having a larger diameter than the rod as a raw material is formed , and the clearance between the portion corresponding to the small diameter portion and the outer diameter of the rod is 0.2, which is the outer diameter of the rod. A combination mold of an upper mold and a lower mold, which is 30% to 30% ,
A holder for attaching the upper mold and / or the lower mold via the cushion function part;
The vertical cross-sectional area formed by the upper mold and the lower mold is larger than that of the small-diameter portion, and the projection surface of the cross-section is provided in a portion including the projection of the cross-section of the small-diameter portion. anda counter punch attached to a holder so as to penetrate the hole through the space from,
The counter punch comes into the mold through a relatively penetrating hole when the cushion function part contracts while the upper mold and the lower mold are in contact with each other.
A forging die characterized by that. 一次成形用金型として請求項４または５に記載の金型で一次成形品を製造する工程、
上記一次成形品を仕上成形用金型により鍛造成形する工程、
上記仕上成形用金型により鍛造成形されたバリ付きの鍛造製品のバリをバリ取り用金型によりトリミングして鍛造製品とする工程を、順送りすることにより細径部とその軸方向の片端もしくは両端に垂直な断面積が細径部より大きくかつその断面の投影面に細径部断面の投影が含まれる部位を有する鍛造製品を製造する鍛造製品の製造方法。A step of producing a primary molded product with the mold according to claim 4 or 5 as a primary molding mold,
A step of forging the above-mentioned primary molded product with a finishing mold,
The process of trimming the burrs of the forged product with burrs forged by the above-mentioned finish molding die to produce the forged products by using the deburring die, and then feeding the narrow diameter portion and its one or both ends in the axial direction. A forged product manufacturing method for manufacturing a forged product having a section having a cross-sectional area larger than that of the small-diameter portion and a projection plane of the cross-section including the projection of the cross-section of the small-diameter portion. 鍛造製品を製造する鍛造製品製造装置において、
単一プレス機内に、一次成形用金型としての請求項４または５に記載の鍛造金型、その一次成形用金型で製造された一次成形品を鍛造成形する仕上成形用金型、およびその仕上成形用金型により鍛造成形されたバリ付きの鍛造製品のバリをトリミングして鍛造製品とするバリ取り用金型が配置されて構成されている、
ことを特徴とする鍛造製品製造装置。 In the forging product manufacturing equipment that manufactures forging products,
6. A forging die according to claim 4 or 5 as a primary molding die in a single press, a finish molding die for forging a primary molded product produced by the primary molding die, and A deburring mold for trimming the burrs of a forged product with burrs that has been forged by a finish molding mold to form a forged product is arranged and configured.
A forged product manufacturing apparatus characterized by that.
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CN101633030B (en) * 2009-08-20 2011-08-24 上海保捷汽车零部件锻压有限公司 Split forging die based on expansion of plastic deformation zone
CN102825128B (en) * 2012-09-06 2014-08-06 宁波刚发实业有限公司 Positioning groove processing die for processing radial rectangular hole in pin
JP5936648B2 (en) * 2014-05-27 2016-06-22 アイダエンジニアリング株式会社 Press forming method and press forming apparatus of semi-solid metal material
CN105834336B (en) * 2016-03-25 2017-12-08 武汉理工大学 A kind of forging method for stepped complicated parting surface parts
US11883875B2 (en) * 2019-04-26 2024-01-30 Proterial, Ltd. Forging device and method for manufacturing forged product
CN110125303A (en) * 2019-05-24 2019-08-16 南宫市精强连杆有限公司 A kind of forging hot trimming and punching composite die
CN113275496B (en) * 2021-05-27 2024-06-21 安徽康尼精密机械有限公司 All-dimensional simultaneous forging die cavity mechanism and opening and closing method
CN114733988B (en) * 2022-03-31 2024-05-24 江苏龙城精锻集团有限公司 High-strength complex-structure point machine extrusion seat forging and manufacturing method thereof

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