【０００１】
【発明の属する技術分野】
本発明は、プリント基板等の穴、スリット或は外形等の打ち抜きを行うポンチ装置の改良に関する。
【０００２】
【従来の技術】
電子機器類のプリント基板その他の薄板部材として、積層合成樹脂薄板、或は銅、アルミ等の金属薄板と合成樹脂薄板との積層板等が多用されており、これ等の薄板に、穴、スリット或は外形等の成形加工として、ポンチによる打ち抜き加工が行われている。
【０００３】
プレス加工としての、ポンチとダイとによる打ち抜き加工では、板材が数ｍｍ以上の厚さの場合、図１８ないし図２１に示すごとく、ポンチＥ、ＦとダイＧ、Ｈとの間にクリアランスＩ、Ｊを設けることが必須とされ、クリアランスＩが小さすぎると、図１８に示すごとく、上層と下層との割れに、食い違いＫ１、Ｋ２が生じ、中間部が引張りによって切断され、図１９に示すごとく、Ｓ字状破断面Ｋが生じ、クリアランスＪが大きすぎると図２０に示すごとく、中間部の引張りによる切断片が上方へ変曲し、図２１に示すごとく、バリＣが発生することが知られている。
【０００４】
被加工材たる板材が１ｍｍ以下の合成樹脂の積層板、合成樹脂板と銅薄板との積層板のごとき薄板の場合でも同様の現象が生じている。
【０００５】
即ち図１１、図１２及び図１３に示すごとく、板厚に応じてクリアランスＬも小さく選定されるが、ポンチＭがダイスＮに向い板材Ｏにくい込み、Ｐ方向に剪断力が作用すると、パンチによる打ち抜きは、パンチとダイとにより被加工板材を挟んで引きちぎる破壊による加工であるため、打ち抜き部Ｑと、残部Ｒとの境界に図１３に示すごとく、広い範囲にわたるクラックＳが発生し、前記図２０、図２１について説明したと同様にバリの発生或は合成樹脂が糸状に引き伸ばされて打ち抜き穴面に残存する所謂糸バリが発生していた。
【０００６】
また、小径孔或は小幅のスリット等の打ち抜き用のポンチでは、図１１ないし図１５に示す如く、ポンチの刃先底面がフラットに成形されているため、図１１に示すごとく、刃先Ｘに摩耗が生じて丸くなり、打ち抜きの繰り返しにより摩耗がポンチ外周面に波及し、前記クリアランスＬが大となると共に、ポンチの切れ味も劣化し、図１８ないし図２１について説明したバリＣ、Ｓ字状破断面Ｋ或は糸バリ等の発生が著しくなる問題が存する。
【０００７】
更に、ポンチの底面が平面の場合、打ち抜き終った瞬間に、抜きカスとポンチ底面との間に真空部分が発生し、高速で上下駆動されているポンチの上昇時に抜きカスが吸引されて所謂カス上り現象が生ずる問題もある。
【０００８】
また前記底面が平面のポンチでは、被加工板材が積層板の場合には、上層の材料が剪断されると同時に延伸された上層の材料がポンチの切刃部分を覆い、そのまま下層材料に当接するため、下層の材料はポンチの切刃が直接当接せずに剪断されるため切断面にバリが発生し易い問題が存するのみでなく、上述の状態のポンチでは、被加工板材に作用する打ち抜き圧が打ち抜き完了まで連続的に変化することとなり、打ち抜き面に変形、撓み、バリ等が生ずる問題もある。
【０００９】
図１５について既述したごとく積層材に、特に接着剤が使用されている積層材に層間剥離が生ずると、厚さの寸法精度の低下のみでなく、加工時の空気の圧縮現象により、微粉となった抜きゴミの剥離部分への侵入の問題も発生する。
【００１０】
前述の抜きカス、抜きクズのポンチ上昇に伴なう問題点の解決策として、図１６に示されるようにポンチＴに空気噴出路Ｕを設け抜きカスＶを吹き飛ばす構造としたり、図１７に示すごとく、抜きカスＶを積極的にバネ弾性で排出する構造等も提案されているが、ポンチの構造が複雑となり、ポンチが小形の場合、加工困難となる問題を有している。
【００１１】
前記諸問題に対し、特開平１１−２４５１９８号公報所載の発明も提案されているが、ポンチとダイスとの相互作用については、該公報の図５に関し、段落番号００１９に、ポンチを分割しなかった場合に、全周縁が凸弧で形成されているポンチでは、スリット穴３４の半円状の両端３５の外方にクラック３６が発生した旨が記述され、ポンチが全周にわたり凸弧刃縁を具備するものの欠点が記述されており、凹弧刃縁を組み合わせた点の有効性は記述されているものの、ポンチの切刃が単一平面において、全周にわたり凸弧刃縁とされている場合の作用時における被加工品のクラックの発生防止策、ポンチ寿命の延長策等については全く開示されていない。
【００１２】
【発明が解決しようとする課題】
前記従来の打ち抜きポンチ装置の有する問題点に鑑み、本発明は、ポンチとダイとの間に広いクリアランスを設ける必要がなく、従ってクリアランスの存在によるクラックの発生、バリや糸バリの発生等が無く、ポンチの打ち抜き作動時には、ポンチの切刃部が、該刃部に作用する内圧によってダイ内面に当接して常時仕上研磨された状態となり、鋭い切刃部が常に被加工板材に切り込む作用を生じ、この切り込みにより、ポンチ下面と被加工板材との間に密封された空気を、該ポンチの切刃部で囲まれた凹陥部内で受止し、前記切刃部の研磨圧として利用することにより、尖鋭な切れ味で、常にクラックの発生や剪断に伴うバリ、糸バリの発生を防止できるのみでなく、該凹陥部の内圧で、剪断完了時に抜きカス、抜きクズの下方への排出が確実に行われ、簡単な構造でありながら尖鋭な切れ味を長期にわたって維持でき、しかもポンチの加工が容易であり、如何なる形状の切刃部でも成形できる打ち抜きポンチ装置を提供することを課題としている。
【００１３】
【課題を解決するための手段】
前記課題を解決するため、請求項１の発明では、打ち抜きポンチが、ダイの上面に対し垂直な外周面と、該外周面下端たる単一水平面内に位置する尖鋭な切刃部とを具備し、該ポンチの下面は、前記切刃部に連続する略凹弧面で囲まれた凹陥部とされ、該ポンチの切刃部とダイとのクリアランスと切刃部の肉厚とが、打ち抜き作動時に凹陥部の前記略凹弧面に作用する内圧により、該切刃部がダイ内周面に当接する寸法に選定されているという構成とした。
【００１４】
請求項２の発明では、請求項１の発明に、ダイの上面に、ワーク押えを兼ねるポンチガイドが配設され、該ポンチガイドのガイド孔にポンチが摺動自在に貫挿されており、該ガイド孔の開孔寸法がダイの開孔寸法と同寸法に設定されているという構成要件を付加した。
【００１５】
【発明の実施の形態】
図１ないし図１０は、請求項１及び請求項２の両発明を併せ適用した実施の一例を示しており、図１、図６及び図７はポンチ１とダイ２及びポンチガイド３並びに被加工板体４、５、６を要部のみの拡大縦断面図として示しており、図２ないし図５はそれぞれ拡大率の異なる拡大半截縦断面図として示している。
【００１６】
各図において、ポンチ１の切刃部の外形寸法と、ダイ２の開口寸法と、ポンチガイド３の開口寸法とは、ポンチ１が噛み合いを生ずることなくダイ２とポンチガイド３の内孔に摺動自在に嵌入しうる微小クリアランスで嵌入され、組み合わされており、図示実施例の各部材は、図８、図９及び図１０に示されるごとく、略正方形のポンチ１を基準として成形されている。なお、本発明の場合、前記クリアランスは３ミクロンメートル〜０．５ミクロンメートルの範囲で、ポンチ及びダイの材質及び被加工板材の材質に応じて選定される。
【００１７】
ポンチ１は、ダイ２の上面７に対し垂直な外周面８と、外周面８の下端たる単一水平面９内に位置する尖鋭な切刃部１０とを具備し、ポンチ１の底面１１は、切刃部１０に連続する略凹弧面１２で囲まれた凹陥部１３を形成している。
【００１８】
図１ないし図７に示す実施例では、略凹弧面１２は、図２に明示されているごとく、二つの緩斜面１４、１５で形成さており、刃先の角度は３０度〜４５度の範囲に選定されているが、単一の緩弧面であってもよく、また凹陥部１３を形成するポンチ１の底面１１は平坦面に形成されているが凹陥部１３は、切刃部１０を下端とするドーム形状であってもよく、その深さは０．２ｍｍ〜０．５ｍｍの範囲に選定されている。然し、被加工板材の材質に応じ、前記角度及び深さは実験的に選択、変更される。
なお、図８ないし図１０に示す実施例では略凹弧面１２は、斜面１２Ａと斜面１２Ｂとで形成されており、切刃部１０を形成する斜面１２Ａの角度θ１は４５度、斜面１２Ｂの角度θ２は３０度に設定され、切刃部１０の一辺の長さは、１．９８ミリメートル、斜面１２Ａと１２Ｂとの高さＨ１とＨ２とは０．２〜０．３ミリメートルの範囲に選定されている。
これ等の斜面１２Ａ、１２Ｂを含む凹弧面１２、凹陥部１３の成形は、立方晶窒化ほう素系またはダイヤモンド系の工具によるドリル加工、リーマー仕上げ、タップ立て仕上げ等により行われ、ポンチ１の材質としては、ＨＲＣ６４（ロックウエル硬度計、スケールＣ）程度のものが採用される。
【００１９】
図１ないし図４は本発明装置の１実施例の作用を時系列的に表しており、図１においてダイ２の上面７に被加工板材４を静置してポンチガイド３で押圧保持し、ポンチ１を降下させた状態を略示しており、ポンチ１の降下に従い、被加工板材４の上面とポンチガイド３の内周面とポンチ１の凹陥部１３とで囲まれた空間に閉じ込められた空気は、矢印で示すごとく、囲繞する各面に押圧力を作用させるが、該空間の容積は、図１１ないし図１５に示したポンチＭの底面が平坦面である場合に比し、凹陥部１３の容積分だけ大きいので、空気の圧縮度合は著しく小さくなり、図４に示されるごとく、被加工板材４の打ち抜き部Ｑを撓曲させること無く、ポンチ１の切刃部１０が図２に示すごとく被加工板材４に切り込み、この切り込みにより打ち抜き部の被加工板材４は、ポンチ３の凹陥部１３の中心方向に押圧される。
【００２０】
この切刃部１０の被加工板材４への進入は、尖鋭な切刃部１０の突き刺さりと切断であるため、被加工板材４の切断部のクラックＳの発生は図３に示されるごとく僅少に留まる。
【００２１】
また切断されつつある打ち抜き部Ｑは、図４に示されるごとく、凹陥部１３内に撓曲され、収容されるため、切刃部１０による切断面にテンションをかけることとなり、引張られた状態で切刃部１０が当り、切断が促進され、バリの無い綺麗な切断面が得られる。
【００２２】
以上記述したポンチ１による打ち抜き作用において、ポンチ１の切刃部１０が被加工板材４に当接した時点から、打ち抜きが完了するまでの間のポンチ１と打ち抜き部Ｑとの間に閉じ込められた空気圧の作用を考察すると、図５に示されるごとく、凹陥部１３に閉じ込められた空気の圧縮圧Ｐ１、Ｐ２と、被加工板材４の切断部からの、押圧力Ｐ３とがポンチ１の切刃部１０内面に作用し、この圧縮圧Ｐ１、Ｐ２と押圧力Ｐ３とにより切刃部１０とその上部の外周面８とは、ダイ２の内周面に弾圧接触され、ポンチ１の切刃部１０の弾性膨出変形が防止されると同時に、該切刃部１０を鋭くする研磨作用をも生ずる。
【００２３】
本発明の前記作用により、ポンチ１の下面１１と被加工板材４の上面との間の空気は、凹陥部１３に貯溜され、切断されつつある打ち抜き部Ｑも凹陥部１３内へ一時的に収容されるので、この凹陥部１３の内圧で打ち抜き部Ｑは排出され、従来の打ち抜き作業で必要であった空気排出の為のプレス速度の低速化を全く考慮することなく生産性を向上させうる。
【００２４】
また尖鋭な切刃部１０が最初に被加工板材４に当接し、切断作用を生ずるので、表面が銅箔の被加工板材４でも、表面が合成樹脂材の被加工板材４であっても、切断のキッカケを強制的に作るので、位相のずれた位置でのクラックの発生を防止する。
【００２５】
更に、凹陥部１３内へ、打ち抜かれる板材、打ち抜きゴミ、粉体等を一時的に収容するので、これ等がポンチ１の切口に架かり、製品の歪みや寸法精度を狂わせることも無い。
【００２６】
本発明では、図６に示すごとく被加工板材５の上面に金属層１６が位置する被加工板材５でも、或は図７に示すごとく被加工板材６の下面に金属層１７が位置する被加工板材６であっても、常に尖鋭な切刃部１０が切り進み、該金属層１６、１７を切断するので切口に金属のダレを生ずることが無い。
【００２７】
請求項２の発明では、ポンチガイド３のガイド孔１８の開孔寸法がポンチ１の外径と同寸法に設定されているので、ポンチ１の切刃部１０はポンチガイド３のガイド孔１８との接触でも研磨作用を受け、その尖鋭な切れ味を維持できるのみでなく、ポンチ１とダイ２とのクリアランスが小さく設定されていても、高速運転時に、ポンチ１は正確にダイ２内へ導入される。
【００２８】
【発明の効果】
請求項１の発明では、ポンチ１がダイ２の上面に対し垂直な外周面の下端の単一水平面内に位置する尖鋭な切刃部１０と、切刃部１０に連続する略凹弧面１２で囲まれた凹陥部１３とを具備し、前記ポンチ１とダイ２との間のクリアランスと切刃部１０の肉厚とが、打ち抜き作動時に、凹陥部１３の略凹弧面１２に作用する内圧により、切刃部１０がダイ２の内周面に当接する寸法に選定されているので、打ち抜き作動時に被加工板材４とポンチ１の下面１１との間に閉じ込められた空気は凹陥部１３に閉じ込められるが、従来の平坦下面のポンチに比し、凹陥部１３の容積分だけ該空気の圧縮度合は小さくなり、従って加工当初は、打ち抜き部Ｑを撓曲させることなく切刃部１０が被加工板材４に切り込み、次いで該打ち抜き部Ｑを凹陥部１３の中心方向へ押圧するので、加工初期に打ち抜き部Ｑの周囲にクラックを発生させる率が著しく小となり、切断面にバリ、糸バリ等を発生させない効果を奏する。
【００２９】
また尖鋭な切刃部１０が最初に被加工板材４に切り込み、かつ打ち抜き部Ｑは凹陥部１３内へ撓曲しながら押圧される結果として、切断面には、凹陥部中心方向への引張り力が作用した状態で切刃部１０が切り込むこととなり、切断を助長し、バリの無い綺麗な切断面を形成しうる効果を奏する。
【００３０】
既述のごとく、ポンチ１による被加工板材４への切り込み時に、略凹弧面１２に作用する切込み圧、凹陥部１３内に閉じ込められた空気、打ち抜き部Ｑによる前記略凹弧面１２に作用する押圧力により、ポンチ１の切刃部１０とこれに連続するポンチ１の外周面とは打ち抜きの往復作動ごとにダイ２の内周面と摩擦接触して研磨作用を受けるので、切刃部１０は常に尖鋭さを保持し、長いポンチ寿命を保持できる効果を奏する。
【００３１】
ポンチ１の切刃部１０が、常に尖鋭な切れ味を保持する結果として、切断面にバリ、糸バリ等の発生の無い美麗な切断面を形成できる効果も奏する。
【００３２】
本発明に係る打ち抜きポンチ装置では、凹陥部１３内に打ち抜き部Ｑが保持され、打ち抜きゴミ、粉体等も同じに打ち抜き部Ｑに保持されたままで１回ごとの打ち抜きが完了し、凹陥部１３の周囲が略凹弧面であることにより打ち抜きと同時に下方へ排出されるのでカス上り、粉塵等のワークへの付着等も、空気吹出し、バネ材による押し出し等の付加装置なしで実現でき、高速運転が可能となり生産性を向上させうる効果を奏する。
【００３３】
請求項２の発明によると、ポンチガイドの開孔寸法がポンチの外径と同寸法とされているので、ポンチとダイとのクリアランスが僅少であっても、ポンチが正確にダイと協働できるのみでなく、ポンチガイド内の往復動によってもポンチの研磨を行いうる効果を奏する。
【図面の簡単な説明】
【図１】実施の一例の要部の略示縦断面図である。
【図２】図１に示すものの加工初期のパンチの作用の半截略示縦断面図である。
【図３】図２に示す状態より加工が進行した状態のパンチと被加工板材との関係を示す図２と同様の半截略示縦断面図である。
【図４】打ち抜き完了の時点の図３と同様の半截略示縦断面図である。
【図５】パンチとダイと、加工時にパンチの凹陥部が受ける作用との関係を示す図４と同様の半截略示縦断面図である。
【図６】金属層が上面に存する被加工板材と加工状態を示す図１と同様の略示縦断面図である。
【図７】金属層が下面に存する被加工板材の加工状態を示す図６と同様の略示縦断面図である。
【図８】ポンチの１実施例の斜面図である。
【図９】図８に示すものの底面図である。
【図１０】図９中Ｚ−Ｚ線縦断面図である。
【図１１】従来のポンチとダイとの加工時の位置関係を示す半截略示縦断面図である。
【図１２】図１１に示すものの加工初期の状態の図１１と同様の半截略示縦断面図である。
【図１３】図１１に示すものの被加工板材の生ずるクラックの状態を示す図１１と同様の半截略示縦断面図である。
【図１４】図１１に示す装置のポンチ下降初期の被加工板材の受ける作用を示す略示縦断面図である。
【図１５】図１４に示す装置による加工時に被加工板材に生ずる層間剥離を模型的に示す略示縦断面図である。
【図１６】従来装置における打ち抜きカスの空気吹出しによる除去手段の要部の略示縦断面図である。
【図１７】従来装置における打ち抜きカスのバネによる除去手段の要部の略示縦断面図である。
【図１８】金属板のクリアランスが小さい従来装置によるポンチによる打ち抜き時に金属板の受ける破断構造の説明的縦断面図である。
【図１９】図１８に示す金属板の打ち抜き完了時の金属板の打ち抜き面構造の説明的縦断面図である。
【図２０】金属板のクリアランスが大きい従来装置によるポンチによる打ち抜き時に金属板の受ける破断構造の説明的縦断面図である。
【図２１】図２０に示す金属板の打ち抜き完了時の金属板の打ち抜き面構造の説明的縦断面図である。
【符号の説明】
１ ポンチ
２ ダイ
３ ポンチガイド
７ ダイの上面
８ ポンチの外周面
１０ 切刃部
１２ 略凹弧面
１３ 凹陥部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a punch device for punching a hole, a slit or an outer shape of a printed circuit board or the like.
[0002]
[Prior art]
As printed circuit boards and other thin plate members for electronic devices, laminated synthetic resin thin plates, or laminated plates of thin metal plates such as copper and aluminum and synthetic resin thin plates, etc. are frequently used, and holes and slits are formed in these thin plates. Alternatively, punching using a punch is performed as a forming process of the outer shape or the like.
[0003]
In the punching process using a punch and a die as a press process, when the plate material has a thickness of several mm or more, as shown in FIGS. 18 to 21, the clearances I, It is essential to provide J, and if the clearance I is too small, as shown in FIG. 18, there are discrepancies K1 and K2 in the crack between the upper layer and the lower layer, and the middle part is cut by pulling, as shown in FIG. 19. , An S-shaped fractured surface K is generated, and if the clearance J is too large, the cut piece is bent upward by the tension at the intermediate portion as shown in FIG. 20, and burrs C are generated as shown in FIG. Have been.
[0004]
The same phenomenon occurs when the plate material to be processed is a thin plate such as a synthetic resin laminated plate having a thickness of 1 mm or less, or a laminated plate of a synthetic resin plate and a copper thin plate.
[0005]
That is, as shown in FIGS. 11, 12, and 13, the clearance L is also selected to be small depending on the plate thickness. However, when the punch M enters the die N and hardens into the plate O and a shear force acts in the P direction, the punch L Since the punching is a breakage process in which the plate material to be processed is torn between the punch and the die, a crack S over a wide range occurs at the boundary between the punched portion Q and the remaining portion R as shown in FIG. In the same manner as described with reference to FIGS. 20 and 21, burrs were generated or so-called thread burrs remaining on the punched hole surface due to the synthetic resin being stretched into a thread shape.
[0006]
Further, in the punch for punching a small diameter hole or a narrow slit, etc., as shown in FIGS. 11 to 15, the bottom surface of the blade edge of the punch is formed flat, so that as shown in FIG. The punches are rounded, and due to repetition of punching, wear spreads to the outer peripheral surface of the punch, and the clearance L increases, and the sharpness of the punch also deteriorates. The burrs C and S-shaped fracture surfaces described with reference to FIGS. There is a problem that the generation of K or thread burrs becomes remarkable.
[0007]
Furthermore, when the bottom of the punch is flat, a vacuum portion is generated between the scrap and the bottom of the punch at the moment when the punching is completed, and the scrap is sucked when the punch which is being driven up and down at a high speed is sucked. There is also a problem that an upward phenomenon occurs.
[0008]
In the case of the punch having a flat bottom surface, when the plate material to be processed is a laminated plate, the upper layer material is sheared and the stretched upper layer material covers the cutting edge portion of the punch and comes into contact with the lower layer material as it is. Therefore, the material of the lower layer is sheared without directly contacting the cutting edge of the punch, so not only there is a problem that burrs are easily generated on the cut surface, but also in the punch in the above-described state, the punching which acts on the plate material to be processed Since the pressure changes continuously until the punching is completed, there is a problem that the punched surface is deformed, bent, burr, and the like.
[0009]
As described above with reference to FIG. 15, when delamination occurs in the laminated material, particularly in the laminated material in which the adhesive is used, not only the decrease in the dimensional accuracy of the thickness but also the fine powder due to the compression phenomenon of air during processing. There is also a problem of invading the removed dust into the peeled portion.
[0010]
As a solution to the above-mentioned problem associated with the rise of the punches and scraps, the punch T is provided with an air ejection path U as shown in FIG. 16 to blow off the scrap V, as shown in FIG. As described above, a structure or the like for positively discharging the scrap V with spring elasticity has been proposed. However, the structure of the punch is complicated, and there is a problem that processing is difficult when the punch is small.
[0011]
With respect to the above problems, an invention described in Japanese Patent Application Laid-Open No. H11-245198 has also been proposed. Regarding the interaction between the punch and the die, the punch is divided into paragraphs 0019 in FIG. In the case where the punch was not formed, it was described that a crack 36 was generated outside the semicircular ends 35 of the slit hole 34 in the punch having the entire periphery formed by a convex arc, and the punch was formed over the entire circumference by the convex arc blade. Although the disadvantages of having an edge are described and the effectiveness of the point combining concave arc edges is described, the cutting edge of the punch is a convex arc edge over the entire circumference in a single plane. There is no disclosure of any measures to prevent the occurrence of cracks in the workpiece during the operation when it is present, or to extend the life of the punch.
[0012]
[Problems to be solved by the invention]
In view of the problems of the conventional punching device, the present invention does not require providing a wide clearance between the punch and the die, and thus eliminates the occurrence of cracks, burrs and yarn burrs due to the presence of the clearance. During the punching operation of the punch, the cutting blade portion of the punch comes into contact with the inner surface of the die due to the internal pressure acting on the blade portion, so that the finish is constantly polished, and the sharp cutting blade always cuts into the plate material to be processed. By this notch, the air sealed between the lower surface of the punch and the plate material to be processed is received in the concave portion surrounded by the cutting blade portion of the punch, and is used as the polishing pressure of the cutting blade portion. In addition to the sharpness, not only can cracks and burrs due to shearing be prevented at all times, but also due to the internal pressure of the recesses, when the shearing is completed, the scraps and scraps are discharged downward. Reliably performed, with a simple structure can maintain a sharp cutting performance over a long period, yet is easily processed punch has an object to provide a punch device which can be molded at the cutting edge of any shape.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, in the invention of claim 1, the punch has an outer peripheral surface perpendicular to the upper surface of the die, and a sharp cutting edge located in a single horizontal plane, which is the lower end of the outer peripheral surface. The lower surface of the punch is a concave portion surrounded by a substantially concave arc surface continuous with the cutting blade portion, and the clearance between the cutting blade portion and the die of the punch and the thickness of the cutting blade portion are determined by a punching operation. In some cases, the cutting edge is selected to have a size in contact with the inner peripheral surface of the die due to an internal pressure acting on the substantially concave arc surface of the concave portion.
[0014]
According to the second aspect of the present invention, in the first aspect of the present invention, a punch guide serving also as a work holder is provided on the upper surface of the die, and the punch is slidably inserted into a guide hole of the punch guide. A component requirement that the opening size of the guide hole is set to the same size as the opening size of the die is added.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 10 show an embodiment in which both the first and second aspects of the present invention are applied. FIGS. 1, 6, and 7 show a punch 1, a die 2, a punch guide 3, and a work to be processed. The plate bodies 4, 5, and 6 are shown as enlarged longitudinal sectional views of only essential parts, and FIGS. 2 to 5 are shown as enlarged half sectional longitudinal sectional views having different magnifications.
[0016]
In each of the drawings, the outer dimensions of the cutting blade portion of the punch 1, the opening size of the die 2, and the opening size of the punch guide 3 are set so that the punch 1 slides in the inner hole of the die 2 and the punch guide 3 without causing engagement. The members are fitted and combined with a small clearance that can be movably fitted, and each member of the illustrated embodiment is formed based on a substantially square punch 1 as shown in FIGS. 8, 9 and 10. . In the case of the present invention, the clearance is selected in the range of 3 μm to 0.5 μm according to the material of the punch and the die and the material of the plate material to be processed.
[0017]
The punch 1 includes an outer peripheral surface 8 perpendicular to the upper surface 7 of the die 2 and a sharp cutting edge 10 located in a single horizontal plane 9 as a lower end of the outer peripheral surface 8. A concave portion 13 surrounded by a substantially concave arc surface 12 which is continuous with the cutting edge portion 10 is formed.
[0018]
In the embodiment shown in FIGS. 1 to 7, the substantially concave arc surface 12 is formed by two gentle slopes 14, 15 as clearly shown in FIG. 2, and the angle of the cutting edge is in the range of 30 to 45 degrees. However, the bottom surface 11 of the punch 1 forming the concave portion 13 is formed as a flat surface, but the concave portion 13 is formed with the cutting edge portion 10. It may have a dome shape with its lower end, and its depth is selected in the range of 0.2 mm to 0.5 mm. However, the angle and the depth are experimentally selected and changed according to the material of the plate material to be processed.
In the embodiment shown in FIGS. 8 to 10, the substantially concave arc surface 12 is formed by a slope 12A and a slope 12B, and the angle θ1 of the slope 12A forming the cutting edge 10 is 45 degrees, and the angle of the slope 12B is 45 degrees. The angle θ2 is set to 30 degrees, the length of one side of the cutting edge 10 is 1.98 mm, and the heights H1 and H2 of the slopes 12A and 12B are selected in the range of 0.2 to 0.3 mm. Have been.
The concave arc surface 12 including these slopes 12A and 12B and the concave portion 13 are formed by drilling with a cubic boron nitride-based or diamond-based tool, reamer finishing, tapping finishing, and the like. As the material, HRC64 (Rockwell hardness scale, scale C) or so is used.
[0019]
FIGS. 1 to 4 show the operation of one embodiment of the apparatus of the present invention in chronological order. In FIG. 1, the plate 4 to be processed is placed on the upper surface 7 of the die 2 and pressed and held by the punch guide 3. This schematically shows a state in which the punch 1 is lowered. As the punch 1 is lowered, the punch 1 is confined in a space surrounded by the upper surface of the workpiece 4, the inner peripheral surface of the punch guide 3, and the recess 13 of the punch 1. The air exerts a pressing force on the surrounding surfaces as indicated by arrows, but the volume of the space is smaller than that of the case where the bottom surface of the punch M shown in FIGS. 11 to 15 is a flat surface. 13, the degree of air compression is significantly reduced, and as shown in FIG. 4, the cutting edge 10 of the punch 1 is not bent as shown in FIG. As shown, a cut is made in the plate material 4 to be processed, Workpiece material 4 of the punching unit is pressed toward the center of the recessed portion 13 of the punch 3.
[0020]
Since the entry of the cutting edge portion 10 into the plate material 4 to be processed is the piercing and cutting of the sharp cutting edge portion 10, the occurrence of cracks S in the cut portion of the plate material 4 to be processed is slightly as shown in FIG. stay.
[0021]
Further, as shown in FIG. 4, the punched portion Q that is being cut is bent and accommodated in the recessed portion 13, so that tension is applied to the cut surface by the cutting blade portion 10, and the cut portion Q is pulled in a pulled state. The cutting edge portion 10 hits, cutting is promoted, and a clean cut surface without burrs is obtained.
[0022]
In the punching action of the punch 1 described above, the punch 1 is confined between the punch 1 and the punched portion Q from the time when the cutting edge portion 10 of the punch 1 comes into contact with the plate material 4 to be punched. Considering the action of the air pressure, as shown in FIG. 5, the compression pressures P1, P2 of the air confined in the recess 13 and the pressing force P3 from the cut portion of the plate material 4 to be processed are the cutting edges of the punch 1. The cutting pressure is applied to the inner surface of the die 2 by the compression pressures P1 and P2 and the pressing force P3. The elastic swelling deformation of the cutting edge 10 is prevented, and at the same time, a sharpening action for sharpening the cutting edge portion 10 is generated.
[0023]
By the above-described operation of the present invention, air between the lower surface 11 of the punch 1 and the upper surface of the plate material 4 to be processed is stored in the concave portion 13, and the punched portion Q being cut is temporarily stored in the concave portion 13. Therefore, the punched portion Q is discharged by the internal pressure of the concave portion 13, and the productivity can be improved without any consideration of a reduction in the press speed for the air discharge required in the conventional punching operation.
[0024]
Further, since the sharp cutting edge portion 10 first comes into contact with the plate material 4 to be processed and causes a cutting action, even if the plate material 4 is made of a copper foil or the surface 4 is made of a synthetic resin material, Since the cutting kick is forcibly made, it is possible to prevent the occurrence of cracks at a position out of phase.
[0025]
Further, since the punched plate material, punched dust, powder, and the like are temporarily stored in the recessed portion 13, they do not bridge the cut of the punch 1 and do not disturb the product distortion or dimensional accuracy.
[0026]
In the present invention, the work piece 5 in which the metal layer 16 is located on the upper face of the work piece 5 as shown in FIG. 6 or the work piece in which the metal layer 17 is located on the lower face of the work piece 6 as shown in FIG. Even with the plate material 6, the sharp cutting edge portion 10 always cuts and cuts the metal layers 16 and 17, so that no metal sag occurs at the cut.
[0027]
According to the second aspect of the present invention, since the opening dimension of the guide hole 18 of the punch guide 3 is set to be the same as the outer diameter of the punch 1, the cutting edge portion 10 of the punch 1 is connected to the guide hole 18 of the punch guide 3. In addition to being able to maintain its sharpness even when contacting the punch, the punch 1 can be accurately introduced into the die 2 during high-speed operation even if the clearance between the punch 1 and the die 2 is set small. You.
[0028]
【The invention's effect】
According to the first aspect of the present invention, the punch 1 has a sharp cutting edge portion 10 located in a single horizontal plane at the lower end of the outer peripheral surface perpendicular to the upper surface of the die 2, and a substantially concave arc surface 12 continuous with the cutting edge portion 10. The clearance between the punch 1 and the die 2 and the thickness of the cutting blade 10 act on the substantially concave arc surface 12 of the recess 13 during the punching operation. Because of the internal pressure, the cutting edge 10 is selected to have a size that abuts against the inner peripheral surface of the die 2, so that the air trapped between the plate material 4 to be processed and the lower surface 11 of the punch 1 during the punching operation will However, the degree of compression of the air is reduced by the volume of the concave portion 13 as compared with a conventional flat bottom punch, and therefore, at the beginning of processing, the cutting edge portion 10 can be bent without bending the punched portion Q. Cut into the plate material 4 to be processed, and then cut out the punched portion Q Since pushing into the third central direction exerts around the machining initial punching unit Q remarkably constant for cracks small, and the burr on the cut surface, the effect of not generating a yarn burrs.
[0029]
Further, as a result of the sharp cutting edge 10 being cut into the plate material 4 to be processed first and the punched portion Q being pressed into the recess 13 while being bent, a tensile force toward the center of the recess is applied to the cut surface. In this state, the cutting blade 10 cuts in a state in which is applied, which promotes cutting, and has an effect of forming a clean cut surface without burrs.
[0030]
As described above, when the punch 1 cuts into the plate material 4 to be processed, the cutting pressure acting on the substantially concave arc surface 12, the air confined in the concave portion 13, and the substantially concave arc surface 12 acting on the punched portion Q. As a result of the pressing force, the cutting edge portion 10 of the punch 1 and the outer peripheral surface of the punch 1 continuous therewith come into frictional contact with the inner peripheral surface of the die 2 and undergo a polishing action each time the punching reciprocating operation causes the cutting edge portion. 10 has the effect of maintaining sharpness at all times and maintaining a long punch life.
[0031]
As a result of the cutting blade portion 10 of the punch 1 always maintaining sharp sharpness, there is also an effect that a beautiful cut surface free of burrs, thread burrs and the like can be formed on the cut surface.
[0032]
In the punching device according to the present invention, the punched portion Q is held in the recessed portion 13, and the punching is completed while the punched dust, powder, and the like are also held in the punched portion Q. Since the area around the surface is a substantially concave arc surface, it is ejected downward at the same time as punching, so it is possible to realize dust climbing up and adhesion of dust etc. to the work without additional equipment such as air blowing, pushing out with a spring material, etc. Driving becomes possible and there is an effect that productivity can be improved.
[0033]
According to the second aspect of the present invention, since the opening dimension of the punch guide is the same as the outer diameter of the punch, the punch can accurately cooperate with the die even if the clearance between the punch and the die is small. In addition to this, there is an effect that the punch can be polished by the reciprocating motion in the punch guide.
[Brief description of the drawings]
FIG. 1 is a schematic vertical sectional view of a main part of an embodiment.
FIG. 2 is a schematic vertical sectional view showing a half of the operation of the punch shown in FIG.
FIG. 3 is a half cut schematic vertical sectional view similar to FIG. 2 showing a relationship between a punch and a plate material to be processed in a state where processing has progressed from the state shown in FIG. 2;
FIG. 4 is a half cut schematic vertical sectional view similar to FIG. 3 at the time of completion of punching.
FIG. 5 is a half cut schematic vertical sectional view similar to FIG. 4, showing the relationship between the punch and the die, and the action that a concave portion of the punch receives during processing.
FIG. 6 is a schematic longitudinal sectional view similar to FIG. 1 showing a plate material to be processed having a metal layer on the upper surface and a processing state;
FIG. 7 is a schematic vertical sectional view similar to FIG. 6, showing a processing state of a plate material on which a metal layer is present on a lower surface.
FIG. 8 is a perspective view of one embodiment of the punch.
FIG. 9 is a bottom view of what is shown in FIG.
FIG. 10 is a vertical sectional view taken along line ZZ in FIG. 9;
FIG. 11 is a half-section schematic longitudinal sectional view showing a positional relationship between a conventional punch and a die during processing.
FIG. 12 is a half cut schematic vertical sectional view similar to FIG. 11, but in an initial state of machining of the one shown in FIG. 11;
FIG. 13 is a half sectional schematic vertical sectional view similar to FIG. 11, showing a state of cracks generated in the plate material to be processed shown in FIG. 11;
FIG. 14 is a schematic vertical sectional view showing the operation of the apparatus shown in FIG.
15 is a schematic vertical sectional view schematically showing delamination occurring in a plate material to be processed during processing by the apparatus shown in FIG. 14;
FIG. 16 is a schematic vertical sectional view of a main part of a removing means of the conventional device for removing punched waste by air blowing.
FIG. 17 is a schematic longitudinal sectional view of a main part of a removing means of a punched waste by a spring in a conventional apparatus.
FIG. 18 is an explanatory vertical cross-sectional view of a fracture structure that a metal plate undergoes when punching with a punch by a conventional device having a small metal plate clearance.
FIG. 19 is an explanatory longitudinal sectional view of a punched surface structure of the metal plate when the punching of the metal plate shown in FIG. 18 is completed.
FIG. 20 is an explanatory vertical cross-sectional view of a rupture structure received by a metal plate at the time of punching with a punch in a conventional device having a large metal plate clearance.
21 is an explanatory longitudinal sectional view of a punched surface structure of the metal plate when the punching of the metal plate shown in FIG. 20 is completed.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 punch 2 die 3 punch guide 7 die upper surface 8 punch outer peripheral surface 10 cutting edge portion 12 substantially concave arc surface 13 concave portion
