JP3668390B2

JP3668390B2 - Hole drilling method having a seating surface on a cylindrical member and punch for punching used therefor

Info

Publication number: JP3668390B2
Application number: JP16720499A
Authority: JP
Inventors: 成幸中川; 謙二金森; 久男谷川; 公雄伊藤
Original assignee: Mitsubishi Aluminum Co Ltd; Nissan Motor Co Ltd
Current assignee: Mitsubishi Aluminum Co Ltd; Nissan Motor Co Ltd
Priority date: 1999-06-14
Filing date: 1999-06-14
Publication date: 2005-07-06
Anticipated expiration: 2019-06-14
Also published as: JP2000351027A

Description

【０００１】
【発明の属する技術分野】
本発明は、筒状部材の内部の内液圧と穴加工用パンチを利用した筒状部材への座面を有する穴加工方法およびそれに用いる穴加工用パンチに関する。
【０００２】
【従来の技術】
近年、ＣＯ₂削減のための車体軽量化や強度向上のための車体補強を目的とした車体やシャーシ部品が求められている。こうした車体やシャーシ部品として、中空の筒状部材を内液圧成形した部品を適用する動きが高まってきている。これらの部品は、所定形状に内液圧成形された後、他の部品を取り付けるための穴や位置決めするための穴が加工される。しかし、最近、経済性や加工精度の向上に対する要請に基づいて、内液圧成形の一連の工程内で穴加工を行う加工方法が検討されている。
【０００３】
例えば、筒状部材の内部に内液圧を負荷しつつ、穴抜きパンチを筒状部材の外側から内部側に向かって打ち付けることにより、穴抜き加工する方法が開示されている（特開平６−２９２９２９号公報）。
【０００４】
【発明が解決しようとする課題】
しかしながら、上述の方法では、抜きカスとなる部分の剛性が低いため、穴抜き加工の過程で、抜きカスとなる部分の周辺部に塑性変形が起こり、穴抜き加工後に、穴の周辺部にダレが生じたり、穴径の精度が低下するといった問題があった。こうした問題は、その穴をロケートピン用の穴として使用する場合に、ロケートピンを立てる座面の精度が低下するという点で特に顕著であった。
【０００５】
こうした問題を解決するため、本発明は、穴の周辺部にダレがなく、穴径の精度の高い座面を有する穴を、筒状部材の内部の内液圧と穴加工用パンチを利用して穴加工する方法およびそれに用いる穴加工用パンチを提供する。
【０００６】
【課題を解決するための手段】
請求項１に記載の発明は、筒状部材の内部に内液圧を負荷しつつ、穴加工用パンチにより前記筒状部材に穴抜き加工を行う加工方法において、一旦、穴抜き加工する方向とは逆方向に、座面と略同一外形で凸形状となる突起を形成し、その後、先端にシャーエッジを有する穴加工用パンチを前進させて、前記突起の先端側から加圧して穴をあけ、さらに引き続き前記穴加工用パンチを前進させて、前記穴を拡大しつつ当該穴の周辺部の余肉を外周方向に押し付けるとともに、前記穴の周辺部の余肉を前記内液圧と前記穴加工用パンチの進行方向に当該穴の周辺部の余肉を押し付ける前記穴加工用パンチの押圧面との間で加圧して、座面を有する穴を成形することに特徴を有する。
【０００７】
この発明によれば、形成された凸形状の突起は、形状効果と加工歪みの蓄積によって剛性を有するので、その突起の先端に、穴加工用パンチで精度よく穴を形成することができる。そして、この穴をさらに拡大し、穴の周辺部の余肉を穴の外周方向に押し付け、筒状部材の内部の内液圧と穴加工用パンチとの間で加圧して、穴の周辺部に座面が成形される。この座面は、内液圧と穴加工用パンチとで成形されるので、穴加工用パンチの外形形状と、内液圧を調節することによって、座面の形状を規制して成形することができる。その結果、筒状部材を内液圧成形するのと同一工程で、座面を有する穴の加工を行うことができる。なお、穴加工用パンチの先端のシャーエッジは、凸形状の突起の先端に食い込み痕を形成するので、加圧されたせん断力を一層集中させることができ、精度よく穴あけできる。
【０００８】
請求項２に記載の発明は、請求項１に記載の筒状部材への座面を有する穴加工方法において、前記穴加工用パンチが、穴開け部材と押圧部材とが一体に形成されてなり、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる前記押圧面を有することに特徴を有する。
【０００９】
この発明によれば、穴加工用パンチの穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有するので、穴あけ、穴の拡大、および、穴の外周方向への穴の周辺部の余肉の押し付けを、連続して行うことができる。また、穴加工用パンチの押圧部材が、座面の形状と同じ外形形状からなる押圧面を有するので、押圧面の形状や位置によって、座面の形状や高さを調節することができる。さらに、穴開け部材と押圧部材が一体となっているので、座面を有する穴の形状は、穴加工用パンチと内液圧によって形状を規制して成形することができると共に、穴加工用パンチの摺動を単純化できる。
【００１０】
請求項３に記載の発明は、請求項１に記載の筒状部材への座面を有する穴加工方法において、前記穴加工用パンチが、穴開け部材と、当該穴開け部材に独立して軸方向に摺動自在に支持される押圧部材とで構成され、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる前記押圧面を有することに特徴を有する。
【００１１】
この発明によれば、穴加工用パンチを構成する穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有するので、穴あけ、穴の拡大、および、穴の外周方向への穴の周辺部の余肉の押し付けを、連続して行うことができる。また、穴加工用パンチを構成する押圧部材が、座面の形状と同じ外形形状からなる押圧面を有するので、押圧面の形状や位置によって、座面の形状や高さを調節することができる。さらに、押圧部材は、穴開け部材とは独立して、軸方向に摺動自在に支持されるので、座面の形状や高さを容易に変更できると共に、穴開け部材のみの変更も可能になる。こうした穴加工用パンチを用いた穴加工方法は、余肉を移動させる座面形成プロセスをより正確に制御する事ができるため、板厚の異なる筒状部材に穴加工する場合や、座面の肉厚やキャビティ面からの高さを適宜調節する場合等に便利である。
【００１２】
請求項４に記載の発明は、請求項１乃至請求項３の何れかに記載の筒状部材への座面を有する穴加工方法において、前記穴加工用パンチの押圧面が、前記筒状部材の外側表面に配置された液圧バルジ成形型のキャビティ面よりも後退した位置に配置されて、前記座面を有する穴が成形されることに特徴を有する。
【００１３】
この発明によれば、座面の形状と同じ外形形状からなる押圧面が、液圧バルジ成形型のキャビティ面よりも後退した位置に配置されているので、穴の周辺部が厚肉で、筒状部材の外側方向に均等厚さに成形された座面を有する穴を加工することができる。得られた座面は、肉厚が厚いので、ねじ切り長さを十分に確保することが可能になると共に、内液圧で押圧面に押し付けられるので、座面の形状と位置が精度よく形成され、ロケートピン用の穴として使用した場合であっても精度の低下が起こらない。
【００１４】
請求項５に記載の発明は、請求項１に記載の筒状部材への座面を有する穴加工方法に用いる穴加工用パンチであって、前記穴加工用パンチが、前記穴を拡大しつつ当該穴の周辺部の余肉を外周方向に押し付ける穴開け部材と前記穴の周辺部の余肉を前記穴加工用パンチの進行方向に押し付ける押圧部材とが一体に成形されてなり、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる前記押圧面を有することに特徴を有する。
【００１５】
請求項６に記載の発明は、請求項１に記載の筒状部材への座面を有する穴加工方法に用いる穴加工用パンチであって、前記穴加工用パンチが、前記穴を拡大しつつ当該穴の周辺部の余肉を外周方向に押し付ける穴開け部材と、当該穴開け部材に独立して軸方向に摺動自在に支持され、前記穴の周辺部の余肉を前記穴加工用パンチの進行方向に押し付ける押圧部材とで構成され、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる押圧面を有することに特徴を有する。
【００１６】
【発明の実施の形態】
以下、添付図面を参照して本発明を具体的に説明する。
【００１７】
図１は、本発明の筒状部材への座面を有する穴加工方法の一例を示す正面断面図である。図１においては、図１（ａ）から図１（ｄ）の順に加工される。
【００１８】
先ず、図１（ａ）に示すように、穴加工用パンチ１１を、筒状部材１９の外側表面に配置される液圧バルジ成形型１６のキャビティ面１８から所定の長さだけ後退した位置に配置する。穴加工用パンチ１１をそうした位置に配置するのは、筒状部材１９の内液圧Ｐを負荷する前であっても負荷した後であってもよい。その方法としては、予めキャビティ面１８から所定の長さだけ隔てた位置に配置しても、キャビティ面１８と同じ位置から後退させて配置してもよい。このうち、穴加工用パンチ１１を成形型１６のキャビティ面１８と同じ位置から後退させる方法としては、空気圧制御、液圧（油圧）制御または機械制御による方法を挙げることができる。
【００１９】
次に、図１（ｂ）に示すように、筒状部材１９を内液圧Ｐによって塑性変形させ、筒状部材１９の外側方向に凸形状となる突起２０を形成する。上述のように、穴加工用パンチ１１は、筒状部材１９の外側表面の位置から所定の間隔を隔てて配置されることになるので、そのスペースに凸形状の突起２０を形成できる。この突起２０は、穴加工用パンチ１１を予め所定の位置に配置する場合には、その後に加えられた筒状部材１９の内液圧Ｐによって形成される。また、穴加工用パンチ１１を所定の位置まで後退させて配置する場合には、後退後に加えられた筒状部材１９の内液圧Ｐによって突起２０を形成したり、筒状部材１９の内液圧Ｐによって穴加工用パンチ１１を後退させつつ突起２０を形成したりすることができる。
【００２０】
このうち、内液圧Ｐによって穴加工用パンチ１１を後退させつつ凸形状の突起２０を形成する方法としては、内液圧Ｐと穴加工用パンチ１１の駆動手段の圧力Ｐｃとの相対差によって後退させる方法を挙げることができる。具体的には、内液圧Ｐを増圧させることによって、圧力Ｐｃとの相対差を拡大して穴加工用パンチ１１を強制後退させたり、圧力Ｐｃを減圧させることによって、内液圧Ｐとの相対差を拡大して穴加工用パンチ１１を強制後退させる。また、内液圧Ｐと圧力Ｐｃの両方を同時に変化させることにより、相対差を拡大して穴加工用パンチ１１を強制後退させてもよい。各圧力の相対差によって穴加工用パンチ１１を強制後退させる方法は、製造上その制御が簡便となるので、通常好ましく用いられる。穴加工用パンチの駆動は、空気圧制御や液圧（油圧）制御で行うことができる。また、バネ等の弾性体による制御を組み合わせたり、機械制御によっても行うことができる。
【００２１】
こうして形成された突起２０は、塑性変形に基づく加工歪みの蓄積やドーム形に変形した突起周辺の形状効果によって、突起２０の先端側からの加圧に対する剛性が、塑性変形していない部分に比べて高くなる。なお、塑性変形した突起２０の外形寸法は、後退した穴加工用パンチ１１の外形寸法とほぼ同じである。
【００２２】
次に、図１（ｃ）に示すように、穴加工用パンチ１１を筒状部材１９の内部側に前進させることによって、凸形状の突起２０の先端に穴あけを行う。
【００２３】
すなわち、穴加工用パンチ１１を、凸形状の突起２０の先端側から筒状部材１９の内部側に加圧して前進させる。このとき、凸形状の突起２０は、その先端側からの加圧に対する剛性が高く、塑性変形しにくいので、穴加工用パンチ１１の先端を突起２０の先端部に押し込むと、穴加工用パンチ１１の先端部にせん断力が集中して、穴加工用パンチ１１の先端部とほぼ同じ形状で穴抜きされる。こうして穴抜きされた破断面は、せん断力が集中して破断されているので、穴径の精度が優れ、また、穴の周辺部のダレが少ない。なお、穴加工用パンチ１１の前進およびその速度等は、上述したような内液圧Ｐと圧力Ｐｃとの相対差を調節して制御したり、機械的に制御して行うことができる。
【００２４】
ここで、本発明で用いられる穴加工用パンチ１１について説明する。穴加工用パンチ１１は、図１に示すように、穴開け部材１２と押圧部材１３が一体に形成されたものを好ましく用いることができる。穴加工用パンチ１１の穴開け部材１２は、穿孔部１２ａと口径決定部１２ｃとこれらを滑らかに連続させた口径拡大部１２ｂとを有している。また、押圧部材１３は、成形すべき座面２３（図１（ｄ）を参照。）の形状と同じ外形形状からなる押圧面１５を有している。
【００２５】
穿孔部１２ａは、口径決定部１２ｃの外径よりも小さい外径で形成されている。この穿孔部１２ａを、剛性が高められた突起２０の先端に押し込むと、突起２０の先端は、押し込まれた部分にせん断力が集中して、穿孔部１２ａの外径と同じ大きさの穴があけられる。通常は、穿孔部１２ａの外周部にシャーエッジ１４を有する穴加工用パンチ１１が使用される。穿孔部１２ａの外周部にシャーエッジ１４を形成することによって、突起２０の先端にはそのシャーエッジ１４による食い込み痕が形成される。この食い込み痕は、穴加工用パンチ１１の加圧によるせん断力をより一層集中させるので、穴抜きを容易に行うことができる。
【００２６】
口径拡大部１２ｂは、穿孔部１２ａと口径決定部１２ｃとを滑らかに連続させるように、次第に外径が拡大するように設けられている。穿孔部１２ａによって穴あけした後、さらに穴加工用パンチ１１を前進させて押し込んでいくと、口径拡大部１２ｂは、穴をさらに拡大していく。このとき、穴の周辺部と成形型１６の内周面１７との間の余肉２２は、口径拡大部１２ｂが押し込まれるにしたがって、穴の外周方向、すなわち成形型１６の内周面１７の方向に押し付けられる。
【００２７】
口径決定部１２ｃは、成形すべき穴径と同じ径で形成されているので、穴加工用パンチ１１を、口径決定部１２ｃまで押し込むことによって、得るべき穴径を成形することができる。
【００２８】
押圧部材１３は、成形すべき座面２３の形状と同じ外形形状からなる押圧面１５を有しているので、押圧面１５の形状と同じ形状の座面２３を得ることができる。
【００２９】
最後に、図１（ｄ）に示すように、穴の周辺部２４を内液圧Ｐと穴加工用パンチ１１とによって、座面２３を成形する。穴加工用パンチ１１を所定の位置まで押し込むと、上述のように、得るべき穴が成形されると共に、穴の外周方向に押し付けられた余肉が、口径決定部１２ｃの外周と押圧部材１３の押圧面１５とで形づくられた形状に、穴加工用パンチと内液圧Ｐとで加圧されて成形される。押圧面１５は、成形すべき座面２３の形状と同じ外形形状で形成されているので、得られる座面２３は押圧面１５の外形形状と同じ形状で成形される。
【００３０】
穴加工用パンチ１１の押圧面１５を、液圧バルジ成形型１６のキャビティ面１８から後退した位置に配置することによって、穴の周辺部２４が厚肉で、筒状部材１９の外側方向に均等厚さで成形された座面２３を有する穴を加工できる。
【００３１】
図２は、本発明の穴加工方法によって得られた座面を有する穴の一例を示す正面断面図である。得られた座面２３は、肉厚が厚いので、ねじ切り長さを十分に確保することが可能になると共に、内液圧Ｐで押圧面１５に押し付けられるので、一定形状で精度のよい座面２３を成形することができる。そのため、ロケートピン用の穴として使用した場合であっても精度の低下が起こらない。座面２３の肉厚は、穿孔部１２ａと口径決定部１２ｃの外径差が大きいほど余肉２２が多くなるので厚くなる。また、座面２３の位置は、押圧面１５とキャビティ面１８の位置関係によって適宜調節することができる。
【００３２】
以上説明したように、本発明の筒状部材１９への座面２３を有する穴加工方法においては、一旦、穴加工する方向とは逆方向に凸形状の突起２０を形成し、その突起２０の先端側から穴加工用パンチ１１を前進させて、穴あけ、穴の拡大、および、穴の外周方向への穴の周辺部の余肉２２の押し付けを、連続して行うことができる。また、穴加工用パンチ１１の押圧部材１５が、座面２３の形状と同じ外形形状からなる押圧面１５を有するので、押圧面１５の形状や位置によって座面２３の形状や高さを調節することができる。なお、この方法によって加工する穴および座面は、丸形状が望ましいが、角形状や異形形状等の何れの形状でもよく、求める形状に適合した穴開け部材１２および押圧部材１３を有した穴加工用パンチ１１を用いることができる。従って、例えば、穴および座面が丸形状の場合には、穴開け部材と押圧部材の何れも丸形状のものが用いられる。
【００３３】
図３は、本発明の穴加工用パンチの他の一例を示す正面断面図である。この穴加工用パンチ３１は、穴開け部材３２と、穴開け部材３２に独立して軸方向に摺動自在に支持される押圧部材３３とで構成されている。穴開け部材３２は、穿孔部３２ａと口径決定部３２ｃとこれらを滑らかに連続させた口径拡大部３２ｂとを有し、押圧部材３３は、座面の形状と同じ外形形状からなる押圧面３５を有している。穴開け部材３２の穿孔部３２ａと口径拡大部３２ｂと口径決定部３２ｃは、上述の穴加工用パンチ１１と同様に、穴あけ、穴の拡大、および、穴の外周方向への穴の周辺部の余肉の押し付けを、連続して行うことができる。また、上述と同様に、穴開け部材３２の先端に、シャーエッジ３４を設けることもできる。図３に示す穴加工用パンチ３１は、押圧部材３３が、穴開け部材３２とは独立して、軸方向に摺動自在に支持されるので、座面の形状や高さを容易に変更できると共に、穴開け部材３２のみの変更も可能になる。こうした穴加工用パンチ３１を用いた穴加工方法は、余肉を移動させる座面形成プロセスをより正確に制御する事ができるため、板厚の異なる筒状部材に穴加工する場合や、座面の肉厚やキャビティ面からの高さを適宜調節する場合等に便利である。
【００３４】
押圧部材３３は、図３に示すように、バネ等の弾性体３９で支持した構造にして、穴開け部材３２と独立して制御することができる。また、押圧部材３３と穴開け部材３２を、油圧シリンダでそれぞれ制御するダブル油圧シリンダ構造にすることもできる。
【００３５】
また、本発明で用いられる筒状部材は、通常アルミニウム合金が用いられるが、合金の種類は特に限定されるものではない。さらに、本発明の穴加工方法は、一般的に用いられている内液圧加工方法に適用することができる。従って、その条件、すなわち流体の種類や内液圧は内液圧成形加工装置の一般的な条件の範囲内で行われる。例えば、内液圧としては、約５００〜１５００気圧の圧力範囲で行われる。
【００３６】
【発明の効果】
以上説明したように、本発明の筒状部材への座面を有する穴加工方法およびそれに用いる穴加工用パンチによれば、一旦形成された凸形状の突起が、形状効果と加工歪みの蓄積によって剛性を有するので、その突起の先端に、穴加工用パンチで精度よく穴を形成することができる。そして、この穴を拡大し、穴の周辺部の余肉を外周方向に押し付け、内液圧と穴加工用パンチとによって、形状が規制された座面を成形することができる。穴加工用パンチの有する押圧面の位置を、液圧バルジ成形型のキャビティ面よりも後退した位置に配置することによって、穴の周辺部が厚肉で、筒状部材の外側方向に均等厚さに成形された座面を有する穴を加工することができる。得られた座面は、肉厚が厚いので、ねじ切り長さを十分に確保することが可能になると共に、内液圧で押圧面に押し付けられるので、座面の形状と位置が精度よく形成され、ロケートピン用の穴として使用した場合であっても精度の低下が起こらない。
【００３７】
本発明の座面を有する穴加工方法およびそれに用いる穴加工用パンチを採用することによって、パイプ状の中空筒状部材を内液圧成形法によって成形加工する際に、成形加工と穴加工を、内液圧成形加工の一連の工程内で同時に行うことができる。その結果、経済性にも優れた車体やシャーシ部品を得ることができる。
【図面の簡単な説明】
【図１】本発明の筒状部材への座面を有する穴加工方法の一例を示す正面断面図である。
【図２】本発明の穴加工方法で加工された座面を有する穴形状の一例を示す正面断面図である。
【図３】本発明の穴加工用パンチの他の一例を示す正面断面図である。
【符号の説明】
１１、３１穴加工用パンチ
１２、３２穴開け部材
１２ａ、３２ａ穿孔部
１２ｂ、３２ｂ口径拡大部
１２ｃ、３２ｃ口径決定部
１３、３３押圧部材
１４、３４シャーエッジ
１５、３５押圧面
１６、３６成形型
１７、３７内周面
１８、３８キャビティ面
１９筒状部材
２０突起
２２余肉
２３座面
２４穴の周辺部
３９弾性体
Ｐ内液圧
Ｐｃ穴加工用パンチの駆動手段の圧力[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hole drilling method having a seating surface on a cylindrical member using an internal hydraulic pressure inside the cylindrical member and a punch for hole drilling, and a punch for hole drilling used therefor.
[0002]
[Prior art]
In recent years, there has been a demand for a vehicle body and chassis parts for the purpose of reducing the weight of the vehicle body for reducing CO ₂ and reinforcing the vehicle body for improving strength. As such vehicle body and chassis parts, there is an increasing movement to apply parts obtained by internal pressure molding of hollow cylindrical members. These components are subjected to internal fluid pressure molding into a predetermined shape, and then holes for attaching other components and holes for positioning are processed. However, recently, a processing method for drilling a hole in a series of processes of internal hydraulic forming has been studied based on a demand for improvement in economic efficiency and processing accuracy.
[0003]
For example, a method of punching a hole by punching a punching punch from the outside to the inside of the cylindrical member while applying an internal hydraulic pressure to the inside of the cylindrical member is disclosed (Japanese Patent Laid-Open No. 6-1994). 292929).
[0004]
[Problems to be solved by the invention]
However, in the above method, since the rigidity of the portion that becomes the punched residue is low, plastic deformation occurs in the peripheral portion of the portion that becomes the punched hole during the punching process. There is a problem in that the accuracy of the hole diameter decreases. Such a problem is particularly remarkable in that when the hole is used as a hole for a locate pin, the accuracy of the seating surface on which the locate pin is raised decreases.
[0005]
In order to solve such a problem, the present invention uses the internal fluid pressure inside the cylindrical member and the punch for drilling the hole having a seat surface with high accuracy of the hole diameter without sagging around the hole. A hole drilling method and a hole punch used therefor are provided.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a processing method in which a hole is punched in the cylindrical member by a punch for hole processing while applying an internal hydraulic pressure to the inside of the cylindrical member. In the opposite direction, a protrusion having a convex shape with substantially the same outer shape as the seating surface is formed, and then a hole punch having a shear edge at the tip is advanced, and a hole is formed by applying pressure from the tip side of the protrusion. further continue to advance the drilling punch Rutotomoni pressing the excess thickness of the peripheral portion of the hole in the outer circumferential direction of the hole while expanding, said fluid pressure the excess thickness of the peripheral portion of the hole and It is characterized in that a hole having a seating surface is formed by pressing between the pressing surface of the hole processing punch that presses the surplus portion of the peripheral portion of the hole in the traveling direction of the hole processing punch.
[0007]
According to the present invention, since the formed convex protrusion has rigidity due to the shape effect and accumulation of processing distortion, a hole can be accurately formed at the tip of the protrusion with the punch for hole processing. Then, the hole is further enlarged, the surplus portion of the peripheral portion of the hole is pressed in the outer peripheral direction of the hole, and the pressure is applied between the internal hydraulic pressure inside the cylindrical member and the punch for punching the hole. A seating surface is formed. Since this seating surface is formed by the internal fluid pressure and the punch for punching holes, the shape of the seating surface can be regulated by adjusting the outer shape of the punch for hole processing and the internal fluid pressure. it can. As a result, the hole having the seating surface can be processed in the same process as the internal pressure molding of the cylindrical member. In addition, since the shear edge at the tip of the punch for punching holes bites into the tip of the convex protrusion, the pressurized shearing force can be further concentrated and the punch can be made with high accuracy.
[0008]
According to a second aspect of the present invention, in the hole drilling method having a seating surface on the cylindrical member according to the first aspect, the punch for punching is formed by integrally forming a punching member and a pressing member. The perforating member has a perforated part, a diameter determining part, and an enlarged diameter part obtained by smoothly connecting these parts, and the pressing member has the pressing surface having the same outer shape as the seating surface. It has a special feature.
[0009]
According to the present invention, the hole forming member of the punch for punching has the perforated part, the diameter determining part, and the diameter enlarged part in which these are smoothly continuous. It is possible to continuously press the excess of the peripheral portion of the hole. Moreover, since the pressing member of the punch for punching holes has a pressing surface having the same outer shape as the shape of the seating surface, the shape and height of the seating surface can be adjusted according to the shape and position of the pressing surface. Furthermore, since the punching member and the pressing member are integrated, the shape of the hole having the seating surface can be formed by regulating the shape by the punch for hole processing and the internal hydraulic pressure, and the punch for hole processing. Can be simplified.
[0010]
According to a third aspect of the present invention, there is provided a drilling method having a seating surface on the cylindrical member according to the first aspect, wherein the punch for punching includes a drilling member and a shaft independent of the drilling member. A pressing member that is slidably supported in the direction, and the perforating member has a perforated part, a diameter determining part, and an enlarged diameter part that smoothly connects them, and the pressing member is It has the characteristic that it has the said press surface which consists of the same external shape as the shape of a seat surface.
[0011]
According to this invention, the hole forming member constituting the punch for hole processing has the perforated part, the diameter determining part, and the diameter enlarged part in which these are smoothly continued. It is possible to continuously press the excess of the peripheral portion of the hole in the outer peripheral direction. Moreover, since the pressing member which comprises the punch for hole processing has a pressing surface which consists of the same external shape as the shape of a seating surface, the shape and height of a seating surface can be adjusted with the shape and position of a pressing surface. . Furthermore, since the pressing member is supported so as to be slidable in the axial direction independently of the punching member, the shape and height of the seating surface can be easily changed, and only the punching member can be changed. Become. The hole drilling method using such a hole punch can more accurately control the seating surface formation process for moving the surplus, so when drilling holes in cylindrical members with different plate thicknesses, This is convenient when adjusting the thickness or height from the cavity surface as appropriate.
[0012]
According to a fourth aspect of the present invention, in the hole drilling method having a seating surface on the cylindrical member according to any one of the first to third aspects, the pressing surface of the punch for hole drilling is the cylindrical member. The hole having the seating surface is formed by being disposed at a position retracted from the cavity surface of the hydraulic bulge forming die disposed on the outer surface of the mold.
[0013]
According to the present invention, the pressing surface having the same outer shape as the shape of the seating surface is disposed at a position retracted from the cavity surface of the hydraulic bulge forming die, so that the peripheral portion of the hole is thick, It is possible to machine a hole having a seating surface formed with a uniform thickness in the outer direction of the shaped member. Since the obtained seating surface is thick, it is possible to secure a sufficient threading length and press against the pressing surface with internal hydraulic pressure, so that the shape and position of the seating surface are formed with high accuracy. Even if it is used as a hole for a locate pin, the accuracy does not decrease.
[0014]
The invention according to claim 5 is a punch for hole machining used in the hole machining method having a seating surface on the cylindrical member according to claim 1, wherein the punch for hole machining enlarges the hole. A punching member that presses the surplus portion of the peripheral portion of the hole in the outer peripheral direction and a pressing member that presses the surplus portion of the peripheral portion of the hole in the advancing direction of the punch for punching the hole are integrally formed. The member has a perforated part, a diameter determining part, and an enlarged-diameter part in which these are smoothly continued, and the pressing member has the pressing surface having the same outer shape as the shape of the seating surface. Have.
[0015]
Invention of Claim 6 is a punch for hole processing used for the hole processing method which has a seat surface to the cylindrical member of Claim 1, Comprising: The said punch for hole processing is expanding the said hole. a perforating member which is pressed against the outer circumferential direction of the excess thickness of the peripheral portion of the bore, is slidably supported in the axial direction independently of the perforating member, the drilling punch excess thickness of the peripheral portion of the hole A pressing member that presses in the advancing direction, and the perforating member has a perforated portion, a diameter determining portion, and an enlarged diameter portion that smoothly connects these, and the pressing member has a shape of the seating surface. And having a pressing surface having the same outer shape.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0017]
FIG. 1 is a front sectional view showing an example of a hole drilling method having a seating surface for a cylindrical member of the present invention. In FIG. 1, the processing is performed in the order from FIG. 1 (a) to FIG. 1 (d).
[0018]
First, as shown in FIG. 1 (a), the hole punching punch 11 is at a position retracted by a predetermined length from the cavity surface 18 of the hydraulic bulge forming die 16 disposed on the outer surface of the cylindrical member 19. Deploy. The hole punch 11 may be arranged at such a position before or after the internal hydraulic pressure P of the cylindrical member 19 is loaded. As a method thereof, it may be arranged in advance at a position separated from the cavity surface 18 by a predetermined length, or may be arranged by retreating from the same position as the cavity surface 18. Among these, examples of a method for retracting the hole punch 11 from the same position as the cavity surface 18 of the mold 16 include a method using air pressure control, hydraulic pressure (hydraulic pressure) control, or mechanical control.
[0019]
Next, as shown in FIG. 1B, the cylindrical member 19 is plastically deformed by the internal hydraulic pressure P to form a protrusion 20 that is convex in the outer direction of the cylindrical member 19. As described above, the hole processing punch 11 is disposed at a predetermined interval from the position of the outer surface of the cylindrical member 19, so that a convex protrusion 20 can be formed in the space. This protrusion 20 is formed by the internal hydraulic pressure P of the cylindrical member 19 applied after that when the hole punching punch 11 is previously arranged at a predetermined position. When the hole punch 11 is moved backward to a predetermined position, the protrusion 20 is formed by the internal fluid pressure P of the cylindrical member 19 applied after the backward movement, or the internal liquid of the cylindrical member 19 is formed. The protrusions 20 can be formed while the hole punch 11 is retracted by the pressure P.
[0020]
Among them, as a method of forming the convex projection 20 while the hole punch 11 is retracted by the internal pressure P, a relative difference between the internal pressure P and the pressure Pc of the driving means of the hole punch 11 is used. A method of retreating can be mentioned. Specifically, by increasing the internal fluid pressure P, the relative difference from the pressure Pc is expanded to forcibly retract the hole punching punch 11, or by reducing the pressure Pc, The hole processing punch 11 is forcibly retracted by enlarging the relative difference. Further, by changing both the internal fluid pressure P and the pressure Pc at the same time, the relative difference may be enlarged to forcibly retract the hole punching punch 11. The method of forcibly retracting the hole punch 11 by the relative difference between the pressures is usually preferably used because its control is simple in manufacturing. The drilling punch can be driven by air pressure control or hydraulic pressure (hydraulic pressure) control. Further, control by an elastic body such as a spring can be combined, or can be performed by mechanical control.
[0021]
The protrusion 20 formed in this way has a higher rigidity against pressure from the tip side of the protrusion 20 than the part that is not plastically deformed due to the accumulation of processing strain based on plastic deformation and the shape effect around the protrusion deformed into a dome shape. Become higher. The outer dimensions of the plastically deformed protrusions 20 are substantially the same as the outer dimensions of the retreated hole punch 11.
[0022]
Next, as shown in FIG. 1C, the hole-forming punch 11 is advanced toward the inside of the cylindrical member 19, thereby making a hole at the tip of the convex protrusion 20.
[0023]
That is, the hole processing punch 11 is advanced from the front end side of the convex projection 20 to the inner side of the cylindrical member 19 by pressing. At this time, the convex protrusion 20 has high rigidity against pressure from the tip side and is difficult to be plastically deformed. Therefore, when the tip of the hole processing punch 11 is pushed into the tip of the protrusion 20, the hole processing punch 11 is pressed. The shearing force concentrates on the tip of the hole, and the hole is punched in substantially the same shape as the tip of the hole processing punch 11. Since the fractured surface thus punched is broken due to the concentration of shearing force, the accuracy of the hole diameter is excellent and the sagging of the peripheral part of the hole is small. The advancement and speed of the hole punching punch 11 can be controlled by adjusting the relative difference between the internal fluid pressure P and the pressure Pc as described above, or mechanically controlled.
[0024]
Here, the punching punch 11 used in the present invention will be described. As shown in FIG. 1, a hole processing punch 11 in which a punching member 12 and a pressing member 13 are integrally formed can be preferably used. The punching member 12 of the punch 11 for drilling has a perforated part 12a, a diameter determining part 12c, and an enlarged diameter part 12b in which these are smoothly continued. Moreover, the pressing member 13 has the pressing surface 15 which consists of the same external shape as the shape of the seat surface 23 (refer FIG.1 (d)) which should be shape | molded.
[0025]
The perforated part 12a is formed with an outer diameter smaller than the outer diameter of the aperture determining part 12c. When the perforated portion 12a is pushed into the tip of the projection 20 with increased rigidity, the tip of the projection 20 has a shearing force concentrated on the pushed-in portion, and a hole having the same size as the outer diameter of the perforated portion 12a is formed. Opened. Normally, a punch 11 for drilling having a shear edge 14 on the outer peripheral portion of the perforated portion 12a is used. By forming the shear edge 14 on the outer peripheral portion of the perforated portion 12a, a bite mark by the shear edge 14 is formed at the tip of the protrusion 20. This bite mark further concentrates the shearing force due to pressurization of the hole punching punch 11, so that the hole can be easily punched.
[0026]
The diameter expanding part 12b is provided so that the outer diameter gradually increases so that the perforated part 12a and the diameter determining part 12c are smoothly continuous. After the hole is punched by the punching portion 12a, when the hole processing punch 11 is further advanced and pushed in, the aperture expanding portion 12b further expands the hole. At this time, the surplus portion 22 between the peripheral portion of the hole and the inner peripheral surface 17 of the molding die 16 is in the outer peripheral direction of the hole, that is, the inner peripheral surface 17 of the molding die 16 as the diameter enlarged portion 12b is pushed. Pressed in the direction.
[0027]
Since the diameter determining part 12c is formed with the same diameter as the hole diameter to be formed, the hole diameter to be obtained can be formed by pushing the hole machining punch 11 into the diameter determining part 12c.
[0028]
Since the pressing member 13 has the pressing surface 15 having the same outer shape as the shape of the seating surface 23 to be molded, the seating surface 23 having the same shape as the pressing surface 15 can be obtained.
[0029]
Finally, as shown in FIG. 1 (d), the seating surface 23 is formed in the peripheral portion 24 of the hole by the internal hydraulic pressure P and the punch 11 for hole processing. When the hole punching punch 11 is pushed into a predetermined position, the hole to be obtained is formed as described above, and the surplus pressed against the outer circumferential direction of the hole is formed between the outer circumference of the diameter determining portion 12c and the pressing member 13. A shape formed with the pressing surface 15 is formed by being pressed with a hole punch and an internal fluid pressure P. Since the pressing surface 15 is formed with the same outer shape as the shape of the seating surface 23 to be molded, the resulting seating surface 23 is molded with the same shape as the outer shape of the pressing surface 15.
[0030]
By disposing the pressing surface 15 of the hole processing punch 11 at a position retracted from the cavity surface 18 of the hydraulic bulge forming die 16, the peripheral portion 24 of the hole is thick, and is uniform in the outer direction of the tubular member 19. A hole having a seating surface 23 formed with a thickness can be processed.
[0031]
FIG. 2 is a front sectional view showing an example of a hole having a seating surface obtained by the hole machining method of the present invention. Since the obtained seating surface 23 is thick, it is possible to secure a sufficient threading length, and the inner seating pressure 23 is pressed against the pressing surface 15 by the internal hydraulic pressure P. 23 can be molded. Therefore, even if it is used as a hole for a locate pin, the accuracy does not decrease. The thickness of the seating surface 23 increases as the difference in outer diameter between the perforated portion 12a and the diameter determining portion 12c increases, so that the surplus thickness 22 increases. Further, the position of the seating surface 23 can be appropriately adjusted depending on the positional relationship between the pressing surface 15 and the cavity surface 18.
[0032]
As described above, in the hole drilling method having the seating surface 23 on the cylindrical member 19 of the present invention, the convex protrusion 20 is once formed in the direction opposite to the hole drilling direction. The hole processing punch 11 can be advanced from the front end side to continuously perform drilling, hole enlargement, and pressing of the extra portion 22 of the peripheral portion of the hole in the outer peripheral direction of the hole. Moreover, since the pressing member 15 of the punch 11 for hole machining has the pressing surface 15 having the same outer shape as the shape of the seating surface 23, the shape and height of the seating surface 23 are adjusted according to the shape and position of the pressing surface 15. be able to. The hole and the seating surface to be processed by this method are preferably round, but may be any shape such as a square shape or an irregular shape, and the hole processing having the punching member 12 and the pressing member 13 suitable for the desired shape. The punch 11 for use can be used. Therefore, for example, when the hole and the seating surface are round, both the hole-piercing member and the pressing member are round.
[0033]
FIG. 3 is a front cross-sectional view showing another example of the punch for punching holes according to the present invention. This punching punch 31 includes a punching member 32 and a pressing member 33 that is supported by the punching member 32 so as to be slidable in the axial direction. The perforating member 32 has a perforated part 32a, a diameter determining part 32c, and an enlarged diameter part 32b obtained by smoothly connecting these parts, and the pressing member 33 has a pressing surface 35 having the same outer shape as the seating surface. Have. The perforated portion 32a, the enlarged diameter portion 32b, and the determined diameter portion 32c of the drilling member 32 are similar to the above-described punch 11 for drilling, in the drilling, expansion of the hole, and the peripheral portion of the hole in the outer circumferential direction of the hole. The surplus meat can be pressed continuously. Similarly to the above, a shear edge 34 can be provided at the tip of the perforating member 32. In the punching punch 31 shown in FIG. 3, since the pressing member 33 is supported so as to be slidable in the axial direction independently of the punching member 32, the shape and height of the seating surface can be easily changed. At the same time, only the perforating member 32 can be changed. The hole drilling method using the hole punching punch 31 can more accurately control the seating surface forming process for moving the surplus, so that when drilling holes in cylindrical members having different plate thicknesses, This is convenient when adjusting the wall thickness and height from the cavity surface as appropriate.
[0034]
As shown in FIG. 3, the pressing member 33 has a structure supported by an elastic body 39 such as a spring and can be controlled independently of the punching member 32. Further, a double hydraulic cylinder structure in which the pressing member 33 and the punching member 32 are respectively controlled by a hydraulic cylinder can be employed.
[0035]
Moreover, although the aluminum alloy is normally used for the cylindrical member used by this invention, the kind of alloy is not specifically limited. Furthermore, the hole machining method of the present invention can be applied to a generally used internal hydraulic machining method. Therefore, the conditions, that is, the type of fluid and the internal hydraulic pressure are performed within the range of general conditions of the internal hydraulic forming apparatus. For example, the internal fluid pressure is performed in a pressure range of about 500 to 1500 atmospheres.
[0036]
【The invention's effect】
As described above, according to the hole drilling method having a seating surface on the tubular member of the present invention and the hole punching punch used therefor, the convex protrusions once formed are formed by shape effects and accumulation of machining distortion. Since it has rigidity, a hole can be accurately formed at the tip of the projection by a punch for punching holes. Then, the hole can be enlarged, the surplus portion of the peripheral portion of the hole can be pressed in the outer peripheral direction, and a seating surface whose shape is regulated can be formed by the internal hydraulic pressure and the hole processing punch. By arranging the position of the pressing surface of the punch for hole machining at a position retracted from the cavity surface of the hydraulic bulge forming die, the peripheral part of the hole is thick and uniform in the outer direction of the tubular member. A hole having a seating surface formed into a shape can be processed. Since the obtained seating surface is thick, it is possible to secure a sufficient threading length and press against the pressing surface with internal hydraulic pressure, so that the shape and position of the seating surface are formed with high accuracy. Even if it is used as a hole for a locate pin, the accuracy does not decrease.
[0037]
By adopting the hole machining method having a seating surface of the present invention and the hole machining punch used therefor, when molding a pipe-shaped hollow cylindrical member by an internal pressure molding method, the molding process and the hole machining, It can be performed simultaneously in a series of steps of the internal hydroforming process. As a result, it is possible to obtain a vehicle body and a chassis component that are excellent in economic efficiency.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing an example of a drilling method having a seating surface for a cylindrical member of the present invention.
FIG. 2 is a front sectional view showing an example of a hole shape having a seating surface processed by the hole processing method of the present invention.
FIG. 3 is a front sectional view showing another example of the punch for hole drilling according to the present invention.
[Explanation of symbols]
11, 31 Hole punching punch 12, 32 Hole punching member 12 a, 32 a Drilling part 12 b, 32 b Diameter expansion part 12 c, 32 c Diameter determination part 13, 33 Press member 14, 34 Shear edge 15, 35 Press surface 16, 36 Mold 17, 37 Inner peripheral surface 18, 38 Cavity surface 19 Cylindrical member 20 Protrusion 22 Extra wall 23 Seat surface 24 Peripheral portion 39 of hole Elastic body P Internal fluid pressure Pc Pressure of driving means of punch for punching hole

Claims

筒状部材の内部に内液圧を負荷しつつ、穴加工用パンチにより前記筒状部材に穴抜き加工を行う加工方法において、
一旦、穴抜き加工する方向とは逆方向に、座面と略同一外形で凸形状となる突起を形成し、
その後、先端にシャーエッジを有する穴加工用パンチを前進させて、前記突起の先端側から加圧して穴をあけ、
さらに引き続き前記穴加工用パンチを前進させて、前記穴を拡大しつつ当該穴の周辺部の余肉を外周方向に押し付けるとともに、前記穴の周辺部の余肉を前記内液圧と前記穴加工用パンチの進行方向に当該穴の周辺部の余肉を押し付ける前記穴加工用パンチの押圧面との間で加圧して、座面を有する穴を成形することを特徴とする筒状部材への座面を有する穴加工方法。In the processing method of performing a hole punching process on the cylindrical member with a punch for hole processing while loading an internal hydraulic pressure inside the cylindrical member,
Once, in the direction opposite to the direction of punching, a protrusion having a convex shape with substantially the same outer shape as the seat surface is formed,
Then, advance the punch for hole processing having a shear edge at the tip, pressurize from the tip side of the projection to make a hole,
Further continue to advance the drilling punch Rutotomoni pressed against the hole in the outer circumferential direction of the excess thickness of the peripheral portion of the hole while expanding, and the inner pressure of the excess thickness of the peripheral portion of the hole the A cylindrical member characterized in that a hole having a seating surface is formed by pressing between the pressing surface of the punch for punching holes that presses the surplus portion of the peripheral portion of the hole in the advancing direction of the punch for punching holes. Drilling method having a seating surface.

前記穴加工用パンチは、穴開け部材と押圧部材とが一体に形成されてなり、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる前記押圧面を有することを特徴とする請求項１に記載の筒状部材への座面を有する穴加工方法。 The punch for punching is formed by integrally forming a punching member and a pressing member, and the punching member has a perforated part, a diameter determining part, and a diameter expanding part in which these are smoothly continued, 2. The hole machining method having a seating surface for a cylindrical member according to claim 1, wherein the pressing member has the pressing surface having the same outer shape as the shape of the seating surface.

前記穴加工用パンチは、穴開け部材と、当該穴開け部材に独立して軸方向に摺動自在に支持される押圧部材とで構成され、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる前記押圧面を有することを特徴とする請求項１に記載の筒状部材への座面を有する穴加工方法。 The punch for punching is composed of a punching member and a pressing member that is slidably supported in the axial direction independently of the punching member, and the punching member includes a punching portion and a diameter determining portion. The cylindrical member according to claim 1, further comprising an enlarged-diameter portion in which these are smoothly continuous, wherein the pressing member has the pressing surface having the same outer shape as the seating surface. Drilling method having a seating surface.

前記穴加工用パンチの押圧面が、前記筒状部材の外側表面に配置された液圧バルジ成形型のキャビティ面よりも後退した位置に配置されて、前記座面を有する穴が成形されることを特徴とする請求項１乃至請求項３の何れかに記載の筒状部材への座面を有する穴加工方法。 The pressing surface of the punch for punching holes is arranged at a position retracted from the cavity surface of the hydraulic bulge forming die arranged on the outer surface of the cylindrical member, and the hole having the seating surface is formed. A hole drilling method having a seating surface on the tubular member according to any one of claims 1 to 3.

請求項１に記載の筒状部材への座面を有する穴加工方法に用いる穴加工用パンチであって、
前記穴加工用パンチは、前記穴を拡大しつつ当該穴の周辺部の余肉を外周方向に押し付ける穴開け部材と前記穴の周辺部の余肉を前記穴加工用パンチの進行方向に押し付ける押圧部材とが一体に成形されてなり、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる前記押圧面を有することを特徴とする穴加工用パンチ。A punch for drilling used in a drilling method having a seating surface on the tubular member according to claim 1,
The punch for punching holes is a pressing member that presses the surplus part of the peripheral part of the hole in the advancing direction of the punch part for punching and the punching member that presses the surplus part of the peripheral part of the hole in the outer peripheral direction while expanding the hole The member is formed integrally, the perforating member has a perforated part, a diameter determining part, and an enlarged diameter part in which these are smoothly continuous, and the pressing member has the same shape as the seating surface A punch for hole machining, comprising the pressing surface having an outer shape.

請求項１に記載の筒状部材への座面を有する穴加工方法に用いる穴加工用パンチであって、
前記穴加工用パンチは、前記穴を拡大しつつ当該穴の周辺部の余肉を外周方向に押し付ける穴開け部材と、当該穴開け部材に独立して軸方向に摺動自在に支持され、前記穴の周辺部の余肉を前記穴加工用パンチの進行方向に押し付ける押圧部材とで構成され、当該穴開け部材が、穿孔部と口径決定部とこれらを滑らかに連続させた口径拡大部とを有し、当該押圧部材が、前記座面の形状と同じ外形形状からなる押圧面を有することを特徴とする穴加工用パンチ。A punch for drilling used in a drilling method having a seating surface on the tubular member according to claim 1,
The drilling punch includes a piercing member for pressing the excess thickness of the peripheral portion in the outer circumferential direction of the hole expanding the bore, is slidably supported independently of the drilling member in the axial direction, the A pressing member that presses the surplus portion of the peripheral portion of the hole in the advancing direction of the punch for punching the hole, and the perforating member includes a perforated portion, a diameter determining portion, and an enlarged diameter portion that smoothly connects these. A punch for hole processing, characterized in that the pressing member has a pressing surface having the same outer shape as the shape of the seating surface.