JP3738402B2

JP3738402B2 - Pipe connecting end forming apparatus and pipe connecting end forming method

Info

Publication number: JP3738402B2
Application number: JP20529595A
Authority: JP
Inventors: 栄村田
Original assignee: 日本エア−テック株式会社
Priority date: 1995-07-19
Filing date: 1995-07-19
Publication date: 2006-01-25
Anticipated expiration: 2015-07-19
Also published as: JPH0929362A

Description

【０００１】
【産業上の利用分野】
本発明は、自動車用冷房装置の冷媒配管に用いるパイプの端部、特に、ユニオン継手により接続するパイプの端部を形成するためのパイプの接続端部の成形装置及びパイプの接続端部の成形方法に関するものである。
【０００２】
【従来の技術】
従来自動車用冷媒装置の冷媒配管に用いるパイプの端部をユニオン継手により結合するパイプの接続端部の構造は、管素材の軸方向一端から離れた位置に該管素材よりも大きな外径を有して形成したフランジ部と、前記フランジ部の前記軸方向一端部に隣接した位置に前記フランジ部よりも小さい外径を有して形成した第１筒部と、前記第１筒部の前記軸方向一端側に隣接した位置に前記第１筒部よりりも小さい外径を有して形成した第２筒部と、前記第２筒部の前記軸方向一端側に隣接した位置に前記フランジ部よりも小さく且つ前記第２筒部よりも大きい外径を有して形成された第３筒部を設けて形成されている。
【０００３】
前記のような構造のパイプの接続端部を形成する方法として，クランプに固定した管素材の軸方向一端及びその近傍部分に前記管素材の軸心に沿って前記管素材に対し相対的に可動な複数種のパンチにより複数回の塑性加工を施すことによって、前記フランジ部、前記第１筒部、前記第２筒部、及び前記第３筒部を形成している（特開平５−３３７５７６号公報参照）。
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の技術で述べた成形方法によると、前記フランジ部、前記第１筒部、前記第２筒部，及び前記第３筒部の各部の成形ごとに、予備成形加工を施す２工程加工方法により成形するものであり、それ故に、前記フランジ部、前記第１筒部，前記第２筒部，及び前記第３筒部を成形するまでに６工程を必要とし、更に、管素材の端部は、フランジ部の形成の際に拡管した後に前記第３筒部の形成において縮径し、この縮径された管端部を再び拡管するために、この再度の拡管加工に際して素管の端部に破壊を生じさせ易く、その結果、第３筒部を形成する素管の最端部の強度が弱められる等の問題点があった。
【０００５】
本発明は、従来の技術の有する問題点に鑑みてなされたものであって、その目的とするところは、ビート出し加工により成形工程を削減すると共に、拡管と縮径を繰り返すことにより生じる管素材の破壊等の発生を解消するパイプの接続端部の製造装置及びその成形方法を提供するものである。
【０００６】
【問題点を解決するための手段】
上記目的を達成するために、本発明に係るパイプの接続端部の成形装置は、管素材を挟んで固定するクランプと、円柱状の先端部とこの先端部よりも外径の太く且つ環状鍔部より太い大径部とこれらを連結するテーパ面を備えてなる第１パンチと、外部パンチの前面の開口部と奥部の小径部とこれらを連結するテーパ面を備える孔部を有すると共に小径部と内部パンチとで溝部を一連に有してなり前記孔部と溝部との軸方向の長さの比が略２：１である第２パンチと、外部パンチの前面の開口部と奥端の小径部とこれらを連結するテーパ面を備える孔部を有すると共に小径部と内部パンチとで溝部を一連に形成し且つ孔部と溝部との軸方向の長さの比が略１：２である第３パンチと、外部パンチの孔部を有すると共に小径部と内部パンチとで溝部を一連に有してなる第４パンチと、前記第４パンチにより成形加工された管素材の第１筒部と第２筒部を挟んで固定する補助クランプと、外部パンチの前面に突出する円柱状の先端軸部を有し且つ外部パンチの前面の先端軸部の周面に環状の浅い溝を有してなる第５パンチから構成する。
【０００７】
本発明に係るパイプの接続先端部の成形方法は、管素材をクランプにて固定し、管素材の軸方向一端側及びその近傍部分を拡張して大径筒部を形成する第１予備工程と、前記第１予備工程で形成した管素材側のテーパ部に接続する大径胴部と小径部とこれらを連結するテーパ部とを有する錐体筒状部とこの錐体筒状部と小径筒部の軸方向の長さの比率を略２：１として一連に有する形状に縮径する第２予備工程と、第２予備工程で形成された管素材の端部側のテーパ部を抑え込んで環状鍔部を張り出し成形すると共に前記環状鍔部の一端側にテーパ状とする錐体筒状部と小径筒部を軸方向の長さの比率が略１：２として一連に形成した第２筒部を形成する予備工程を含む環状鍔部の成形工程と、前記環状鍔部の一端側に接続する錐体筒状部を抑え込んで軸方向に垂直な段部を有する第１筒部の成形とこの段部から先端まで第２筒部を形成する第１筒部と第２筒部の成形工程と、前記第１筒部と第２筒部を補助クランプにより固定し、第２筒部の先端を抑え込んで環状隆起部を形成する環状隆起部を形成する環状隆起部成形工程とからなる。
【０００８】
なお、前記第１成形パンチで拡径する外径はクランプの溝より稍々大径とするのが好ましく、第２成形パンチで形成する錐体筒部の大径胴部の外径はクランプの溝とはほぼ同径にするのが好ましい。
【０００９】
【作用】
本発明において、管素材である素管の接続端部は、管素材をクランプにて固定し、第１パンチにより、管素材の軸方向一端側及びその近傍部分を拡張して大径筒部を形成する第１予備工程を施し、次いで、第２パンチにより、前記第１予備工程で形成した管素材側のテーパ部に接続する大径胴部と小径部とこれらを連結するテーパ部とを有する錐体筒状部とこの錐体筒状部と小径筒部の軸方向の長さの比率を略２：１として一連に有する形状に縮径する第２予備工程を施す。そして、第３パンチにより、第２予備工程で形成された管素材の端部側のテーパ部を抑え込んで環状鍔部を張り出し成形する。この成形工程において、前記環状鍔部の一端側にテーパ状とする錐体筒状部と小径筒部を軸方向の長さの比率が略１：２として一連に形成した第２筒部を形成する予備工程が施される。次に、第４パンチにより、前記環状鍔部の一端側に接続する錐体筒状部を抑え込んで軸方向に垂直な段部を有する第１筒部の成形とこの段部から先端まで第２筒部を形成する。この成形工程を終了した状態で、前記第１筒部と第２筒部を補助クランプにより固定し、第２筒部の先端を抑え込んで環状隆起部を形成し、管素材の端部には、図９に示すような、環状鍔部５と、環状鍔部５よりも小さな外径の第１筒部６と、この第１筒部６よりも小さな外径の第２筒部７と、前記環状鍔部５よりも小さく且つ前記第２筒部よりも大きい外径の環状隆起部８を有する形状の接続端部１ａが得られる。
【００１０】
このように、第１成形工程及び第２成形工程により連続的に予備工程を施して、次の第３工程で、環状鍔部を形成し、第４成形工程で第１筒部と第２筒部を形成し、第５成形工程で環状隆起部を形成するので、パイプの接続端部は５工程と少ない工程数で完成させることが可能となる。そして、第１成形工程により、拡管した後に、第２〜第５成形工程で築地しぼりながら縮径することにより各部を成形するので、各部の成形工程における加工部分に無理な応力を与えることなく各部の所望の形状を得ることができ、加工時の破壊から保護し、高い強度の接続端部を有する製品の提供を可能とする。
【００１１】
【実施例】
実施例について図面を参照して説明する．
図１は、パイプ１の接続端部１ａと相手側のパイプ２をハーフユニオン３とユニオンナット４とのユニオン継手によって結合して示し、前記ハーフユニオン３は、内筒の所定位置に環状段部３ａを有し、この環状段部３ａを境にして、基端側から環状段部３ａへ向けて相手側となるパイプ２が挿着されて一体に固着設置され、先端側に前記パイプ１の接続端部１ａを受け入れる受け口部３ｂを有し、先端に面３ｃ取りが施され、外周のネジ部３ｄにユニオンナット４を面３ｃの側から螺着自在にしてなる。
【００１２】
前記パイプ１の接続端部１ａは、ハーフユニオン３の先端の面３ｃとユニオンナット４の小径部４ａに狭着される鍔部５を有し、この鍔部５より先端側に、鍔部５より外径が小さい第１筒部６と、第１筒部６より小径の第２筒部７と、前記第１筒部６と略同径の環状隆起部８を有し、前記第１筒部６と環状隆起部８が前記ハーフユニオン３の受け口部３ｂの中に挿入される外径を有すると共に前記第２筒部７の底部が第１筒部６と環状隆起部８の間にOリング９を収容する凹溝となる構造に形成されている。
【００１３】
図２乃至図９は、本発明のパイプの接続端部の成形装置及びその成形方法を成形工程順に示すものである。
【００１４】
図２は、パイプの接続端部を成形するための素管を固定した状態のクランプを一部断面で示す正面図であり、該クランプは、第１クランプ部２１と第２クランプ部２２を重ね合わせて円形の溝２０をなし、それぞれの第１及び第２クランプ部２１，２２の端面には溝２０の周囲に沿って設けられた溝２１ａ，２２ａを有して形成される。
そして、接続端部を形成するための管素材である素管１０が、先端部分を溝２１ａ、２２ａの側から突出させて、第１及び第２クランプ２１，２２によって挟み込んで固定される。この素管１０は、以後の成形工程が終了するまでクランプ部２１，２２から外さないで固定される。
【００１５】
図３は、第１成形工程に用いるパンチ及び第１成形工程を終了した加工状態を示し、第１パンチ３０は丸い先端面３１を有する円柱状の先端部３２と、この先端部３２よりも外径の太い大径部３３と、これらを連結するテーパ面３４を備えて形成されている。
そして、前記クランプ２１及び２２に挟んだ素管１０に、第１パンチ３０で、図３では、右方から素管１０の開口部に押し当てると，素管１０を半径方向外方にテーパ部１１を介して外径がD１となるように拡管する。前記外径D１はクランプ部２１，２２の溝２１ａ，２２ａより稍々大径の拡管となる。
【００１６】
図４は、第２成形工程に用いるパンチ及び第２成形工程を終了した加工状態を示し、第２パンチ４０は、外部パンチ４１の前面に内径がD１である開口部４２と、内径がD２である奥部の小径部４３と、これらを連結するテーパ面４４を備える孔部４５を有すると共に小径部４３の内径D２と内部パンチ４６とで厚みｙを有する溝部４７を一連に有した構造になり、前記孔部４５と溝部４７との軸方向の長さの比率は、孔部：溝部＝２：１〜１．８：１．２として形成している。
そして、前記第１成形工程で外径D１に拡管した素管１０の端部に、第２パンチを押し付けて、第１成形工程で形成した素管１０の前記テーパ部１１に接続する外径がD３である大径胴部１２と、外径がD２である小径筒部１３とこれらを連結するテーパ部１４を有する錐体筒状部と、前記錐体筒状部の小径側に軸方向へ小径筒部１３が一連に形成される。前記大径胴部１２の外径D３はクランプ部２１，２２の溝２０とほぼ同径となるように縮小形成される。前記第１成形工程と第２成形工程は、次の工程の形状出しのための第１及び第２の予備工程である。
【００１７】
図５は、第３成形工程に用いるパンチ、及び第３成形工程を終了した加工状態を示し、第３パンチ５０は、外部パンチ５１の内径がD４である開口部５２と、内径がD２である奥部の小径部５３と、これらを連結するテーパ面５４を備える孔部５５を有すると共に小径部５３の内径D２と内部パンチ５６とで厚みｙを有する溝部５７を一連に有する構造になり、前記開口部５２の内径D４は、素管１０の外径より大きく、クランプ部２１，２２の円形の溝２０より小さく、また、第３パンチ５０の孔部５５と溝部５７との軸方向の長さの比率は、孔部：溝部＝１：２〜０．７：１．３として、第３パンチ５０の孔部５５を第２パンチ４０の孔部４５の略半分とし、第３パンチ５０の溝部５７を第２パンチ４０の溝部４７の略２倍の長さに形成する。
そして、第２成形工程で形成された素管１０の端部に、第３パンチ５０を押し付けて抑え込み工程を施す。第３パンチ５０を押し付けると、第３パンチ７０の内径D４の開口部５２と内径D２の小径部５３を連絡するテーパ面５４で第２工程で形成された素管１０の端部のテーパ部１４に押し付けてると，図５に示した素管１０の端部は、第１クランプ部２１，第２クランプ部２２の端面の円形の溝２１ａ，２２ａの中に鍔部５が張り出すように抑え込み形成され、この鍔部５の軸方向一端側に、テーパ部１５になる錐体筒状部と小径筒部１６とを一連に備えた形状に形成される。この第３成形工程は、鍔部５の成形工程と次の第１筒部６0を成形する予備工程を含むものである。
【００１８】
図６は、第４成形工程に用いるパンチ、及び第４成形工程を終了した加工状態を示し、第４パンチ６０は、外部パンチ６１の内径D４の孔部６２と、小径部６３の内径D２と内部パンチ６４とで厚みｙを有する溝部６５を一連に有した構造になる。前記外部パンチ６１の孔部６２の内径D４は、環状鍔部５の外径より小径とし、素管１０の外径より大きい径に形成される。
そして、第３成形工程で形成されたテーパ部１５と外径D２の小径筒部１６を有する素管１０の端部に、第４パンチ６０を押し付けると、図５で示した素管１０の端部は、図６で示すように、テーパ部１５から軸方向に垂直な段部１７を有する第１筒部６と，この段部１７から軸方向へ先端部まで第２筒部７が形成される。この第４成形工程は、第１筒部６と第２筒部７との成形工程となる。
【００１９】
図７は、第４成形工程に連続して行われるビード付け加工をする際に使用される補助クランプを示し、この補助クランプ７０は、第１補助クランプ部７１と第２補助クランプ部７２からなり、図６の第４成形工程で形成された素管１０の第１筒部６と第２筒部７を挟み込む第１内径面７３と、第２内径面７４と、この第２内径面７４の端面の周囲に沿って設けられた内径D４である第３内径面７５を有する孔部を備えて形成される。
そして、前記第４成形工程に連続して，次の第５成形工程のビート付け加工をする際に、素管１０の端部に補助クランプ７０を装着する。
【００２０】
図８は、第５成形工程に用いるパンチ、及び第５成形工程を終了した加工状態を示し、第５パンチ８０は、外部パンチ８１の前面の中心から突出する円柱状の先端軸部８２を有し、外部パンチ８１の前面の先端軸部８２の周面に環状の浅い溝８３を有する構造に形成してなる。
そして、第４成形工程で形成された段部１７の一端側に連続して有する外径D２の第２筒部７に前記補助クランプ７０で挟み付けて、第５パンチ８０を押しつける。溝８３に素管１０の端部をはめ込んで押しつけると、第２筒部７の先端側に、補助クランプ７０の第３内径面７５に抑え込むことで、第２筒部７に隣接して軸方向一端側に隆起する環状隆起部８を形成し、第１筒部６と環状隆起部８の間の底部にOリングを装着する溝を形成し、図９に示す素管１０の先端部には、図１のパイプ１に示す接続端部１ａの形状、即ち、素管１０の軸方向一端から離れた位置に素管１０の外径よりも大きな外径をもって形成された環状鍔部５と、この環状鍔部５の軸方向一端側に隣接した位置に環状鍔部５よりも小さな外径をもって形成された第１筒部６と、前記第１筒部６の軸方向一端側に隣接した位置に第１筒部６よりも小さな外径をもって形成された第２筒部７と、この第２筒部７の軸方向一端側に隣接した位置に前記環状鍔部５よりも小さく且つ前記第２筒部よりも大きい外径をもって形成された環状隆起部８を有する形状の接続端部１ａが得られる。そして、このパイプ１の接続端部１ａを図１に示すように、ユニオン継手により相手側のパイプ２に接続することができる。
【００２１】
【発明の効果】
本発明は上記のような発明であるから、パイプの接続端部の最後の工程をビード付け加工を採用することにより、光定数が従来に比較して減少することが可能となり、しかも、製造が容易で、量産に適したパイプの端部の構造を提供することができる等の利点がある。
【図面の簡単な説明】
【図１】本発明によって製造されたパイプの接続端部をユニオン継手により相手側のパイプと接続して示す断面図である。
【図２】素管を固定して示すクランプの断面図である。
【図３】第１成形工程に用いるパンチの形状及び第１成形工程を終了した加工状態を示す断面図である。、
【図４】第２成形工程に用いるパンチの形状及び第２成形工程を終了した加工状態を示す断面図である。、
【図５】第３成形工程に用いるパンチの形状及び第３成形工程を終了した加工状態を示す断面図である。、
【図６】第４成形工程に用いるパンチの形状及び第４成形工程を終了した加工状態を示す断面図である。、
【図７】第４成形工程を終えた素管の第１及び第２筒部を固定して示すクランプの断面図である。
【図８】第５成形工程に用いるパンチの形状及び第５成形工程を終了した加工状態を示す断面図である。、
【図９】本発明の全ての成形工程を完了したパイプの接続端部を示す正面図である。
【附合の説明】
１パイプ
５環状鍔部
６第１筒部
７第２筒部
８環状隆起部
１０素管
１１テーパ部
１２大径胴部
１３小径筒部
１４テーパ部
１５テーパ部
１６小径筒部
１７段部
２１第１クランプ部
２２第２クランプ部
３０第１パンチ
３１先端面
３２先端部
３３大径部
３４テーパ面
４０第２パンチ
４１外部パンチ
４２開口部
４３小径部
４４テーパ面
４５孔部
４６内部パンチ
４７溝部
５０第３パンチ
５１外部パンチ
５２開口部
５３小径部
５４テーパ面
５５孔部
５６内部パンチ
５７溝部
６０第４パンチ
６１外部パンチ
６２孔部
６３小径部
６４内部パンチ
６５溝部
７０補助クランプ
８０第５パンチ
８１外部パンチ
８２先端軸部
８３溝部[0001]
[Industrial application fields]
The present invention relates to a pipe connecting end forming apparatus for forming an end of a pipe used for refrigerant piping of an automobile air conditioner, particularly a pipe connecting end by a union joint, and a pipe connecting end forming. It is about the method.
[0002]
[Prior art]
The structure of the connecting end of the pipe that connects the end of the pipe used for the refrigerant piping of the conventional refrigerant system for automobiles with a union joint has a larger outer diameter than that of the pipe material at a position away from one end in the axial direction of the pipe material. A flange portion formed as a first cylindrical portion having a smaller outer diameter than the flange portion at a position adjacent to the one axial end portion of the flange portion, and the shaft of the first cylindrical portion. A second cylindrical portion formed with a smaller outer diameter than the first cylindrical portion at a position adjacent to one end side in the direction, and the flange portion at a position adjacent to the one axial end side of the second cylindrical portion. It is formed by providing a third cylinder portion having an outer diameter smaller than that of the second cylinder portion.
[0003]
As a method of forming the connection end portion of the pipe having the above-described structure, it is relatively movable with respect to the tube material along the axial center of the tube material at one axial end of the tube material fixed to the clamp and its vicinity. The flange portion, the first tube portion, the second tube portion, and the third tube portion are formed by performing a plurality of times of plastic working with a plurality of types of punches (Japanese Patent Laid-Open No. 5-337576). See the official gazette).
[0004]
[Problems to be solved by the invention]
However, according to the molding method described in the prior art, a two-step process for performing a preforming process for each molding of the flange part, the first cylinder part, the second cylinder part, and the third cylinder part. Therefore, six steps are required until the flange portion, the first tube portion, the second tube portion, and the third tube portion are formed. The portion is expanded at the time of forming the flange portion and then reduced in diameter at the time of forming the third cylindrical portion. As a result, there is a problem that the strength of the outermost portion of the raw tube forming the third cylindrical portion is weakened.
[0005]
The present invention has been made in view of the problems of the prior art, and the object of the present invention is to reduce the molding process by beat-out processing and to produce a tube material by repeating the expansion and contraction. An apparatus for manufacturing a connecting end portion of a pipe that eliminates the occurrence of breakage and the like and a method for forming the same are provided.
[0006]
[Means for solving problems]
In order to achieve the above object, a pipe connecting end forming apparatus according to the present invention comprises a clamp for holding a tube material in between, a columnar tip, an outer diameter larger than this tip and an annular flange. A first punch having a large diameter part thicker than the part and a tapered surface connecting them, an opening part on the front surface of the external punch, a small diameter part on the back part, and a hole part having a tapered surface connecting them, and a small diameter A second punch in which the ratio of the axial length of the hole and the groove is approximately 2: 1, and the opening and the rear end of the front of the external punch. The groove portion is formed by a series of the small diameter portion and the internal punch, and the axial length ratio of the hole portion and the groove portion is approximately 1: 2. A third punch, a hole of an external punch, and a small diameter portion and an internal punch. A fourth punch comprising a part in a series, an auxiliary clamp for fixing sandwich the first cylindrical portion of the molded processed tubeshell the second tubular portion by the fourth punch, protruding on the front of the outer punch It comprises a fifth punch having a cylindrical tip shaft portion and having an annular shallow groove on the peripheral surface of the tip shaft portion of the front surface of the external punch.
[0007]
A method for forming a connecting tip of a pipe according to the present invention includes a first preliminary step of fixing a pipe material with a clamp and expanding a first end side in the axial direction of the pipe material and its vicinity to form a large-diameter cylindrical portion. A cone-shaped cylindrical portion having a large-diameter barrel portion, a small-diameter portion connected to the tapered portion on the tube material side formed in the first preliminary step, and a tapered portion connecting them, and the cone-cylindrical portion and the small-diameter tube. The second preliminary step of reducing the diameter to a shape having a series of axial length ratios of about 2: 1, and the tapered portion on the end side of the tube material formed in the second preliminary step is held in an annular shape A second cylinder part in which a flange part is overhang-molded and a cylindrical cylinder part and a small diameter cylinder part that are tapered on one end side of the annular flange part are formed in series with an axial length ratio of approximately 1: 2. A step of forming the annular flange including a preliminary step of forming a cylindrical tube portion connected to one end of the annular flange Forming a first tube portion having a stepped portion perpendicular to the axial direction, forming steps of the first tube portion and the second tube portion forming the second tube portion from the step portion to the tip, and the first tube And an annular ridge forming step of forming an annular ridge that forms an annular bulge by holding the tip of the second cylinder and holding the tip of the second cylinder.
[0008]
The outer diameter expanded by the first forming punch is preferably larger than the groove of the clamp, and the outer diameter of the large-diameter barrel portion of the cone cylinder formed by the second forming punch is preferably It is preferable that the groove has substantially the same diameter.
[0009]
[Action]
In the present invention, the connection end portion of the raw material tube is fixed by clamping the tube material, and the first punch is used to expand the one end side in the axial direction of the tube material and the vicinity thereof to form the large-diameter cylindrical portion. The first preliminary step to be formed is then performed, and then the second punch has a large-diameter body portion and a small-diameter portion connected to the tapered portion on the tube material side formed in the first preliminary step, and a tapered portion that connects them. A second preliminary step of reducing the diameter to a shape having a series of cone cylinder portions and a ratio of axial lengths of the cone cylinder portions and the small diameter cylinder portions to about 2: 1 is performed. Then, the annular punching portion is stretched and formed by suppressing the taper portion on the end portion side of the tube material formed in the second preliminary process by the third punch. In this molding step, a second cylinder part is formed in which a conical cylinder part and a small-diameter cylinder part that are tapered at one end side of the annular flange part are formed in series with an axial length ratio of approximately 1: 2. A preliminary process is performed. Next, with a fourth punch, the first cylindrical portion having a step portion perpendicular to the axial direction is suppressed by holding down the conical cylindrical portion connected to one end side of the annular flange portion, and the second portion from the step portion to the tip is formed. A cylinder part is formed. In the state where this molding process is completed, the first tube portion and the second tube portion are fixed by an auxiliary clamp, the tip of the second tube portion is suppressed to form an annular ridge, and the end of the tube material is As shown in FIG. 9, the annular flange 5, the first cylindrical portion 6 having an outer diameter smaller than the annular flange 5, the second cylindrical portion 7 having an outer diameter smaller than the first cylindrical portion 6, A connecting end 1a having an annular raised portion 8 having an outer diameter smaller than the annular flange 5 and larger than the second cylindrical portion is obtained.
[0010]
As described above, the preliminary process is continuously performed by the first molding process and the second molding process, the annular flange is formed in the next third process, and the first cylinder part and the second cylinder are formed in the fourth molding process. Since the annular bulge is formed in the fifth molding step, the connection end of the pipe can be completed with a small number of steps of five steps. Then, after expanding the tube by the first molding process, each part is molded by reducing the diameter while squeezing the ground in the second to fifth molding processes, so that each part without applying excessive stress to the processed part in the molding process of each part The desired shape can be obtained, and it is possible to provide a product having a high-strength connection end portion, which is protected from breakage during processing.
[0011]
【Example】
Embodiments will be described with reference to the drawings.
FIG. 1 shows a connecting end 1a of a pipe 1 and a mating pipe 2 connected by a union joint of a half union 3 and a union nut 4. The half union 3 has an annular stepped portion at a predetermined position of an inner cylinder. 3a, with the annular stepped portion 3a serving as a boundary, a mating pipe 2 is inserted from the base end side toward the annular stepped portion 3a, and is fixedly installed integrally. It has a receiving port portion 3b for receiving the connecting end portion 1a, a surface 3c is cut at the tip, and the union nut 4 can be screwed to the outer thread portion 3d from the surface 3c side.
[0012]
The connecting end 1 a of the pipe 1 has a flange 5 that is narrowly attached to the front end surface 3 c of the half union 3 and the small-diameter portion 4 a of the union nut 4. A first cylindrical portion 6 having a smaller outer diameter; a second cylindrical portion 7 having a smaller diameter than the first cylindrical portion 6; and an annular raised portion 8 having substantially the same diameter as the first cylindrical portion 6; The portion 6 and the annular raised portion 8 have an outer diameter inserted into the receiving port 3 b of the half union 3, and the bottom of the second tubular portion 7 is between the first tubular portion 6 and the annular raised portion 8. It is formed in a structure that becomes a concave groove that accommodates the ring 9.
[0013]
2 to 9 show a forming apparatus and a forming method for a connecting end portion of a pipe according to the present invention in the order of forming steps.
[0014]
FIG. 2 is a front view showing a partial cross-sectional view of a clamp in a state where an element pipe for forming a connecting end portion of a pipe is fixed. The clamp overlaps a first clamp portion 21 and a second clamp portion 22. In addition, a circular groove 20 is formed, and end faces of the first and second clamp portions 21 and 22 are formed to have grooves 21 a and 22 a provided along the periphery of the groove 20.
And the raw tube 10 which is a pipe | tube raw material for forming a connection end part protrudes from the groove | channels 21a and 22a side, and is pinched | interposed and fixed by the 1st and 2nd clamps 21 and 22. FIG. The base tube 10 is fixed without being removed from the clamp portions 21 and 22 until the subsequent molding process is completed.
[0015]
FIG. 3 shows a punch used in the first molding step and a processed state after the first molding step. The first punch 30 has a cylindrical tip portion 32 having a round tip surface 31 and an outer side than the tip portion 32. A large-diameter portion 33 having a large diameter and a tapered surface 34 that connects them are formed.
Then, in FIG. 3, when the element tube 10 sandwiched between the clamps 21 and 22 is pressed against the opening of the element tube 10 from the right in FIG. 3, the element tube 10 is tapered outward in the radial direction. 11 is expanded so that the outer diameter becomes D1. The outer diameter D1 is an expanded tube whose diameter is often larger than the grooves 21a and 22a of the clamp portions 21 and 22.
[0016]
FIG. 4 shows the punch used in the second molding step and the processed state after the second molding step. The second punch 40 has an opening 42 with an inner diameter D1 on the front surface of the external punch 41 and an inner diameter D2. It has a structure having a series of grooves 47 having a thickness y with an inner diameter D2 of the small-diameter portion 43 and an internal punch 46, as well as a small-diameter portion 43 in the back and a hole 45 having a tapered surface 44 connecting them. The ratio of the length in the axial direction of the hole 45 and the groove 47 is formed as hole: groove = 2: 1-1: 1.8: 1.2.
And the outer diameter connected to the said taper part 11 of the element | tube 10 formed in the 1st shaping | molding process by pressing a 2nd punch against the edge part of the element | tube 10 expanded to the outer diameter D1 at the said 1st shaping | molding process. A large-diameter body portion 12 that is D3, a small-diameter tubular portion 13 that has an outer diameter D2 and a conical tubular portion that has a tapered portion 14 that connects them, and a small-diameter side of the conical tubular portion in the axial direction. The small diameter cylindrical portion 13 is formed in series. The outer diameter D3 of the large-diameter body portion 12 is reduced and formed so as to be substantially the same diameter as the groove 20 of the clamp portions 21 and 22. The first molding step and the second molding step are first and second preliminary steps for shaping the next step.
[0017]
FIG. 5 shows a punch used in the third molding step and a processed state after the third molding step. The third punch 50 has an opening 52 having an inner diameter D4 of the outer punch 51 and an inner diameter D2. The inner diameter D2 of the small-diameter portion 53 and the internal punch 56 have a series of grooves 57 having a thickness y, and the inner diameter D2 of the small-diameter portion 53 and the internal punch 56. The inner diameter D4 of the opening 52 is larger than the outer diameter of the raw tube 10 and smaller than the circular groove 20 of the clamp parts 21 and 22, and the axial length between the hole 55 and the groove part 57 of the third punch 50 is set. The ratio of the hole portion: groove portion is 1: 2 to 0.7: 1.3, the hole portion 55 of the third punch 50 is substantially half the hole portion 45 of the second punch 40, and the groove portion of the third punch 50 is 57 is formed to be twice as long as the groove 47 of the second punch 40.
And the 3rd punch 50 is pressed on the edge part of the raw tube 10 formed at the 2nd shaping | molding process, and the suppression process is given. When the third punch 50 is pressed, the tapered portion 14 at the end of the base tube 10 formed in the second step is formed by the tapered surface 54 that connects the opening 52 of the inner diameter D4 of the third punch 70 and the small diameter portion 53 of the inner diameter D2. 5, the end portion of the raw tube 10 shown in FIG. 5 is restrained so that the flange portion 5 protrudes into the circular grooves 21 a and 22 a on the end surfaces of the first clamp portion 21 and the second clamp portion 22. It is formed and formed in a shape including a series of conical cylindrical portions and small-diameter cylindrical portions 16 that become tapered portions 15 on one end side in the axial direction of the flange portion 5. The third forming step includes a forming step for the flange portion 5 and a preliminary step for forming the next first tube portion 60.
[0018]
FIG. 6 shows a punch used in the fourth molding step and a processed state after the fourth molding step. The fourth punch 60 includes a hole 62 having an inner diameter D4 of the external punch 61 and an inner diameter D2 of the small-diameter portion 63. The inner punch 64 has a structure having a series of groove portions 65 having a thickness y. The inner diameter D4 of the hole 62 of the external punch 61 is smaller than the outer diameter of the annular flange 5 and is larger than the outer diameter of the base tube 10.
When the fourth punch 60 is pressed against the end of the base tube 10 having the tapered portion 15 and the small-diameter cylindrical portion 16 having the outer diameter D2 formed in the third forming step, the end of the base tube 10 shown in FIG. As shown in FIG. 6, the first cylindrical portion 6 having a step portion 17 perpendicular to the axial direction from the tapered portion 15 and the second cylindrical portion 7 from the step portion 17 to the tip end portion in the axial direction are formed. The This fourth forming step is a forming step of the first tube portion 6 and the second tube portion 7.
[0019]
FIG. 7 shows an auxiliary clamp used when a beading process performed continuously in the fourth molding step. The auxiliary clamp 70 includes a first auxiliary clamp portion 71 and a second auxiliary clamp portion 72. 6, a first inner diameter surface 73 that sandwiches the first cylinder portion 6 and the second cylinder portion 7 of the base tube 10 formed in the fourth forming step in FIG. 6, a second inner diameter surface 74, and the second inner diameter surface 74. It is formed with a hole having a third inner diameter surface 75 which is an inner diameter D4 provided along the periphery of the end surface.
Then, the auxiliary clamp 70 is attached to the end portion of the raw tube 10 when performing the beating process in the next fifth molding step, following the fourth molding step.
[0020]
FIG. 8 shows a punch used in the fifth molding step and a processed state after the fifth molding step, and the fifth punch 80 has a cylindrical tip shaft portion 82 projecting from the center of the front surface of the external punch 81. The outer punch 81 is formed in a structure having an annular shallow groove 83 on the peripheral surface of the front end shaft portion 82 on the front surface.
Then, the fifth punch 80 is pressed against the second cylindrical portion 7 having an outer diameter D2 continuously provided on one end side of the step portion 17 formed in the fourth molding step with the auxiliary clamp 70. When the end portion of the element tube 10 is fitted and pressed into the groove 83, it is pressed against the third inner diameter surface 75 of the auxiliary clamp 70 on the distal end side of the second tube portion 7, so that it is adjacent to the second tube portion 7 in the axial direction. An annular raised portion 8 is formed on one end side, and a groove for mounting an O-ring is formed at the bottom between the first tubular portion 6 and the annular raised portion 8, and the tip of the element tube 10 shown in FIG. 1, the shape of the connecting end 1 a shown in the pipe 1 of FIG. 1, that is, an annular flange 5 formed with a larger outer diameter than the outer diameter of the element tube 10 at a position away from one axial end of the element tube 10; A first cylinder part 6 formed with a smaller outer diameter than the annular collar part 5 at a position adjacent to one end side of the annular collar part 5 in the axial direction, and a position adjacent to one axial end side of the first cylinder part 6 Adjacent to one end side in the axial direction of the second cylinder portion 7 and the second cylinder portion 7 formed with a smaller outer diameter than the first cylinder portion 6. A connecting end portion 1a having an annular raised portion 8 formed at a position having an outer diameter smaller than that of the annular flange portion 5 and larger than that of the second cylindrical portion is obtained. And the connection end part 1a of this pipe 1 can be connected to the other pipe 2 by a union joint as shown in FIG.
[0021]
【The invention's effect】
Since the present invention is an invention as described above, it is possible to reduce the optical constant compared to the prior art by adopting a beading process at the last step of the connecting end of the pipe, and the manufacturing process is There is an advantage that a pipe end structure that is easy and suitable for mass production can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a connecting end of a pipe manufactured according to the present invention connected to a mating pipe by a union joint.
FIG. 2 is a cross-sectional view of a clamp in which a raw tube is fixed.
FIG. 3 is a cross-sectional view showing the shape of the punch used in the first molding step and the processed state after the first molding step. ,
FIG. 4 is a cross-sectional view showing a shape of a punch used in a second molding step and a processed state after the second molding step. ,
FIG. 5 is a cross-sectional view showing a shape of a punch used in a third molding step and a processed state after the third molding step. ,
FIG. 6 is a cross-sectional view showing the shape of the punch used in the fourth forming step and the processed state after the fourth forming step. ,
FIG. 7 is a cross-sectional view of a clamp in which the first and second tube portions of the raw pipe after the fourth forming step are fixed.
FIG. 8 is a cross-sectional view showing the shape of the punch used in the fifth molding step and the processed state after the fifth molding step. ,
FIG. 9 is a front view showing a connecting end portion of a pipe that has completed all the forming steps of the present invention.
[Explanation of attachment]
DESCRIPTION OF SYMBOLS 1 Pipe 5 Annular collar part 6 1st cylinder part 7 2nd cylinder part 8 Annular protruding part 10 Elementary pipe 11 Taper part 12 Large diameter trunk | drum 13 Small diameter cylinder part 14 Tapered part 15 Tapered part 16 Small diameter cylinder part 17 Step part 21 1 clamp part 22 2nd clamp part 30 1st punch 31 tip surface 32 tip part 33 large diameter part 34 taper surface 40 2nd punch 41 external punch 42 opening part 43 small diameter part 44 taper surface 45 hole part 46 internal punch 47 groove part 50 Third punch 51 External punch 52 Opening 53 Small diameter portion 54 Tapered surface 55 Hole 56 Internal punch 57 Groove 60 Fourth punch 61 External punch 62 Hole 63 Small diameter 64 Internal punch 65 Groove 70 Auxiliary clamp 80 Fifth punch 81 External Punch 82 Tip shaft 83 Groove

Claims

A clamp that holds the tube material in between, a cylindrical tip, a first punch that has a larger outer diameter than the tip and a larger diameter that is thicker than the annular flange, and a tapered surface that connects them, The outer punch has an opening on the front surface, a small-diameter portion at the back, and a hole having a tapered surface connecting them, and has a series of grooves formed by the small-diameter portion and the internal punch. A second punch having a length ratio in the direction of about 2: 1; an opening on the front surface of the external punch; a small diameter portion on the back end; and a hole having a tapered surface connecting them; And a third punch having an axial length ratio between the hole and the groove of approximately 1: 2, a hole having an external punch, and a groove having a small diameter and an internal punch. a fourth punch made having a series of, is molded by the fourth punch An auxiliary clamp for securing sides of the first cylindrical portion and the second cylindrical portion of the tube material, the circumferential surface of the front surface of the tip end shaft portion of and external punch has a cylindrical tip shaft portion protruding to the front of the outer punch An apparatus for forming a connecting end portion of a pipe, comprising a fifth punch having an annular shallow groove.

A tube material is fixed by a clamp, and a first preliminary step for forming a large-diameter cylindrical portion by expanding one end side in the axial direction of the tube material and its vicinity, and a taper on the tube material side formed in the first preliminary step The ratio of the length in the axial direction of the conical cylindrical portion and the small diameter cylindrical portion is approximately 2: 1. A second preliminary step of reducing the diameter into a series of shapes, and a taper portion on the end side of the tube material formed in the second preliminary step is formed to project and form an annular flange, and one end side of the annular flange A step of forming an annular flange including a preliminary step of forming a second cylindrical portion in which a cylindrical cylindrical portion and a small-diameter cylindrical portion having a tapered shape are formed in a series with an axial length ratio of approximately 1: 2. The first tube portion having a step portion perpendicular to the axial direction while suppressing the conical tube-shaped portion connected to one end side of the annular flange portion The first cylinder part and the second cylinder part forming step, forming the second cylinder part from this step part to the tip, and fixing the first cylinder part and the second cylinder part with an auxiliary clamp, the second cylinder part A method for forming a connecting end portion of a pipe, comprising: an annular ridge forming step for forming an annular ridge portion that suppresses the tip of the annular ridge to form an annular ridge portion.