JP3836520B2 - Catheter tube and method and apparatus for manufacturing the same - Google Patents

Description

【０００７】
設定温度が７０℃未満の場合には軟化しないため拡張が不可能であり、７０〜８５℃の場合には軟化が不十分なため拡張時に亀裂が発生する。反対に、設定温度が１１５℃を越えると、フレアー拡張体１に触れた先から半溶融状態になって拡張せず、その場で団子状態になってしまう。
従って、フレアー加工可能領域は約８７〜１１５℃となるが、８７℃及び１１５℃付近の温度は実際上は不安定領域であり、安定してフレアー加工できる温度範囲は９０〜１０５℃である。更に、９０〜１０３℃で成形したフレアー部７は、離型時に残留応力のために収縮し、成形時の形状を完全に保てない欠点がある。従って、ある程度満足のいくフレアー部７を得るための温度範囲は約１０４〜１０５℃となるが、この場合でも僅かながら収縮が生じた。
【０００８】
上記のように、成形温度条件が極めて狭く、また離型時の収縮が避けられないという問題は、結晶性の高い樹脂、即ち温度上昇に対し融点付近で急に軟化し溶融する特性を示す樹脂、例えばポリエチレン、ポリプロピレン、ポリエチレンテレフタレート、ポリビニルアルコール、ポリアミド等において、より顕著に現れる。
【０００９】
次に、成形されたフレアー部７の外観形状の品質が必ずしも十分ではないという問題がある。即ち、この第１の方法では、図１０に示したように、一定肉厚のチューブ４の一端をフレアー拡張体１により強制的に円錐状に拡張させるので、表面積の拡大によりフレアー部７の肉厚は図１１（従来品）に示すようにフレアー拡張始端Ａから末端Ｂに向かって薄肉化が生じるとともに、図１４に示すようにフレアー部７の先端に丸味８が形成される。尚、従来のカテーテル用チューブのフレアー拡張始端Ａ及び末端Ｂを図１２に図示した。
【００１０】
前記肉厚の薄肉化により、図１４に示すように、フレアー部７の外側円錐面の円錐角αが内側円錐面の円錐角βよりも小さくなるので、チューブ接続用締め付け金具９、１０の間でのフレアー部７の締め付けにむらを生じ、シール性が低下する。
【００１１】
また、前記フレアー部７の先端の丸味８により、図１５に示すように、両締め付け金具９、１０により挟まれる面積ｆが、台形エツジ状のフレアー部（図中の点線で示す）の面積Ｆよりも減少し、より一層シール性が低下する。
【００１２】
更に、フレアー部７の肉厚の変化量や先端の丸味８は制御されて成形されているわけではないので、同一条件下で成形されてもフレアー部の形状は微妙に異なり、安定した形状のものを得にくい。そのため、締め付け金具９、１０による対応が困難である。
【００１３】
次に、第２のフレアー加工方法においては、射出成形機の金型部分が高価であり、装置も大がかりとなるので生産コストが飛躍的に増大する上、フレアー部がパーツ化されるのでチューブとの接続工程が必要になるという問題がある。
特に、チューブとの接続については、材質により接着が困難な場合があり、例えば材質がポリエチレンの場合には、良好な接着剤がないために熱溶着による接続方法が採られている。しかし、架橋のかかったチューブや、アイオノマーのようなイオン基による凝集力の強い樹脂においては、熱溶着でも十分な接着力が得られにくく、パーツ化されたフレアー部をチューブに接続するのは容易ではない。また、何らかの方法で接続できたとしても、前記第１のフレアー加工方法によりチューブの一端にフレアー部を一体的に成形したものに比べて、接続個所の信頼性に劣ることは避けられない。
【００１４】
本発明は、以上のような従来の技術の問題点を解決して、低コストで信頼性が高く、しかもフレアー部の外観形状の品質が高いカテーテル用チューブを提供することを目的とする。
【００１５】
【課題を解決するための手段】
上記目的を達成するために、第１の発明のカテーテル用チューブは、熱可塑性合成樹脂からなり、チューブの一端に円錐状のフレアー部を有するカテーテル用チューブにおいて、前記フレアー部が均一の厚さに且つその内外両円錐面が互いに平行に形成され、その断面形状は台形エッジ状を呈するとともに、前記フレアー部が接続部を介することなく前記チューブに一体的に形成されてなる構成としたものである。そして前記フレアー部の先端には、チューブ接続用締め付け金具への装着性を増すために、円筒状の鍔部を形成してもよい。
【００１６】
また、第２の発明のカテーテル用チューブの製造方法は、第１の発明のカテーテル用チューブを製造するための方法であって、円錐状のフレアー成形面の頂部から軸方向にチューブ案内棒を突設してなるフレアー拡張体の外周に外金型を嵌装して、これらフレアー拡張体と外金型との間に断面形状が台形エッジ状のフレアー成形空間を形成する第１工程と、熱可塑性合成樹脂からなるチューブを前記チューブ案内棒の外周に挿入して前記フレアー成形空間内に導入する第２工程と、導入された前記チューブの端末を加熱溶融しながら前記フレアー成形空間内に充填してフレアー部を成形して行く第３工程と、充填完了後に冷却固化により前記フレアー部の形状を定着させる第４工程と、端末に前記フレアー部が成形されたチューブを前記外金型及びフレアー拡張体から離型する第５工程とからなる構成になっている。
【００１７】
更に、第３の発明のカテーテル用チューブの製造装置は、第２の発明の製造方法を実施するための装置であって、外周に円錐状のフレアー成形面を有し、該フレアー成形面の頂部から軸方向にチューブ案内棒が突設され、内部にチューブ加熱用ヒーターと加熱温度調節用センサーとが埋設されてなる、カテーテル用チューブの端末を加熱溶融しながら後記フレアー成形空間内に充填するためのフレアー拡張体と、開閉自在の中空割り型で、中空部にフレアー成形凹窩を有し、前記フレアー拡張体の外周を抱恃して前記フレアー成形凹窩と前記フレアー成形面との間に断面形状が台形エッジ状のフレアー成形空間を形成する外金型と、チューブを前記チューブ案内棒の外周に挿入して前記フレアー成形空間内に押し込むスライドテーブルとを具備してなる構成になっている。
【００１８】
【作用】
本発明では、フレアー部をフレアー拡張体と外金型との間に形成した円錐状のフレアー成形空間内で射出成形の要領で成形するので、フレアー部は均一の厚さに且つその内外両円錐面が互いに平行に形成され、その断面形状はフレアー成形空間と同じ台形エッジ状を呈する（後述の実施例に対応する図１及び図２参照）。
【００１９】
従って、図２に示すようにフレアー部をチューブ接続用締め付け金具に装着したときは、締め付け金具の締め付けにむらがなく、両締め付け金具により挟まれる面積Ｆが従来のフレアー部における面積（図１２（ｂ）中のｆ）よりも広い。そのため、シール性は従来のフレアー部より優れている。
【００２０】
また、フレアー部が接続部を介することなくチューブの一端に一体的に形成されるので、チューブの信頼性が高い。
更に、フレアー部が射出成形の要領で形成されるので、フレアー部の外観形状の品質は射出成形品と同様に極めて高い。
【００２１】
【実施例】
以下、本発明の一実施例を図１〜図８に基づいて説明する。
図１は本発明の一実施例を示すカテーテル用チューブの断面図である。図１に示すように、カテーテル用チューブ１１は、低密度ポリエチレン等の熱可塑性合成樹脂からなるチューブ１２の一端に、円錐状のフレアー部１３が接続部を介することなく一体的に成形されている。
【００２２】
フレアー部１３は、均一の厚さに且つその内外両円錐面１４、１５が互いに平行に成形されている。従って、両円錐面１４、１５の円錐角は相等しく、θとなっている。そして、フレアー部１３の断面形状は後述するフレアー成形空間３４（図４、図５）と同じ台形エッジ状を呈している。
【００２３】
このカテーテル用チューブ１１は、フレアー部１３がチューブ１２に一体的に成形されるので信頼性が極めて高い。また、図２に示すように、フレアー部１３をチューブ接続用締め付け金具９、１０に装着したとき、フレアー部１３が均一の厚さに且つ両円錐面１４、１５が互いに平行に成形されているので、締め付けにむらがなく、両締め付け金具９、１０に挟まれる面積Ｆが広いのでシール性が良好である。
【００２４】
上記カテーテル用チューブ１１は、図３に示すような製造装置により製造することができる。この製造装置は、支持台２１にフレアー拡張体２２、外金型２３及びスライドテーブル２４を組み付けてなるものである。
【００２５】
支持台２１には、前部軸受２５及び後部軸受２６が立設され、これら両軸受２５、２６の間に支軸２７が架設されている。
フレアー拡張体２２は、チューブ加熱用ヒーター２８及び加熱温度調節用センサー２９を内蔵した伝熱性の良い黄銅製棒状体で、基部が前部軸受２５の上部に植設されている。このフレアー拡張体２２は、図４に拡大して示すように先端部外周に円錐角がθの円錐状フレアー成形面３０を有し、フレアー成形面３０の頂部から軸方向にステンレス製のチューブ案内棒３１が突設されている。フレアー成形面３０には、離型性を良くするためにテフロン（ｄｕ Ｐｏｎｔ社の登録商標）等フッソ系樹脂コーティング又は離型剤塗布が施されている。
【００２６】
外金型２３は、開閉自在の中空割り型で、離型性及耐熱性の良好なテフロンからなり、フレアー拡張体２２に対する位置調整可能に支持体３２を介して支軸２７上に取り付けられている。この外金型２３は、図４に拡大して示すように、中空部に円錐角がθの円錐状フレアー成形凹窩３３を有し、フレアー拡張体２２の外周を抱恃したとき、フレアー成形凹窩３３とフレアー成形面３０との間に円錐角がθの円錐状フレアー成形空間３４を形成する。このフレアー成形空間３４の断面形状は台形エッジ状にしてある。
スライドテーブル２４は、チューブ１２をチューブ案内棒３１の外周に挿入してフレアー成形空間３４内に押し込むためのもので、支軸２７上に軸方向移動可能に取り付けられている。
【００２７】
上記製造装置によりカテーテル用チューブ１１を製造するには、まず第１工程で図４に示すように、外金型２３を閉じてフレアー拡張体２２に対し所定位置に位置決めすることにより、外金型２３でフレアー拡張体２２の外周を抱恃し、フレアー成形空間３４を形成する。なお、前記外金型２３の位置決め及び芯出しは、図示のように、外金型２３の中空部にフレアー拡張体２２の円柱部に嵌合可能な凹窩を設けることにより容易に達成される。
【００２８】
次に第２工程で、図３に示すように、チューブ１２をスライドテーブル２４にセットするとともに、ヒーター２８及びセンサー２９によりフレアー拡張体２２を１５０℃に加熱しておく。続いて、図５に示すように、スライドテーブル２４を移動させてチューブ１２の端末をチューブ案内棒３１の外周に挿入し、溶融代を２０mmにセットした後、チューブ１２を４０mm／分の速度でフレアー成形空間３４内に導入して行く。
【００２９】
次の第３工程では、図６に示すように、導入されたチューブ１２の端末がフレアー成形面３０に接触し、ヒーター２８からの伝熱で溶融し始める。溶融した樹脂は、引き続き導入されてくるチューブ１２によりフレアー成形空間３４内に押し込まれ、更なる加熱により流動性を増すとともに、引き続き押し込まれてくる溶融樹脂の圧力でフレアー成形空間３４内に充填され、図７に示すようなフレアー部１３を成形して行く。
【００３０】
次に第４工程で、図７に示すように、充填完了と同時にチューブ１２の導入を停止し、風冷により８０℃まで冷却して、フレアー成形空間３４内のフレアー部１３を固化し、その形状を定着させる。
【００３１】
最終の第５工程で、図８に示すように、外金型２３を開き、チューブ１２の端末にフレアー部１３が成形されたカテーテル用チューブ１１を外金型２３及びフレアー拡張体２２から離型して取り出す。
得られたカテーテル用チューブ１１のフレアー部の肉厚は、図１１（本発明品）に示すように、フレアー拡張始端Ａから末端Ｂまで均一であった。尚、本発明のカテーテル用チューブのフレアー拡張始端Ａ及び末端Ｂを図１３に示した。
【００３２】
本発明者らは、上記操作を６０回繰り返したが、同じ品質のカテーテル用チューブ１１を再現性良く得ることができた。しかも、射出成形品に匹敵する品質を持ったフレアー部１３を得ることができた。また、温度条件についても、１３５〜１６５℃の広い範囲でフレアー部１３の成形が可能であった。
【００３３】
なお、フレアー部１３の形状は、本実施例では図１に示すような形状としたが、必ずしもこれに限定するものではなく、他の実施例として図９に示すように、フレアー部１３の先端に円筒状の鍔部１６を一体成形してもよい。これにより、締め付け金具９、１０への装着性が増す。
【００３４】
更に、本発明をより効果的にするために、ヒーター２８による加熱の代わりに外金型２３を発熱させたり、これらを併用してもよい。また、チューブ案内棒３１は、チューブ１２の挿入を容易にするために先端にテーパーを付してもよく、またフレアー拡張体２２からの伝熱を少なくするために材質をセラミックにしたり、中空管にして熱を逃がすようにしてもよい。更にまた、チューブ１２のフレアー成形空間３４内への導入に際してチューブ１２の挫屈を防止するために、冷却機構を設けてチューブを冷却し、その腰を強くしてもよい。
【００３５】
【発明の効果】
以上説明したように、本発明では、フレアー成形空間内に導入したチューブの端末を融点まで加熱し、射出成形の要領でフレアー部を形成する。従って、フレアー部の冷却固化に際しては残留応力が残らず、フレアー部は均一の厚さに且つその内外両円錐面が互いに平行に形成され、その断面形状はフレアー成形空間と同じ形状（台形エッジ状）を呈する。
【００３６】
このようにして得たフレアー部は、チューブ接続用締め付け金具に装着したとき、締め付け金具の締め付けにむらがなく、また両締め付け金具により挟まれる面積が従来のフレアー部における面積よりも広いので、優れたシール性を発揮する。
【００３７】
また、フレアー部が接続部を介することなくチューブの一端に一体的に形成されるので、カテーテル用チューブの信頼性が高まる。
【００３８】
更に、フレアー部が射出成形の要領で形成されるので、フレアー部の外観形状のばらつきは飛躍的に改善される。
【００３９】
更にまた、製造装置の構造が簡易であるので、カテーテル用チューブの製造コストが低くてすむ。
【００４０】
なお、フレアー部の先端に円筒状の鍔部を形成すれば、フレアー部のチューブ接続用締め付け金具への装着性が向上する。
【図面の簡単な説明】
【図１】本発明のカテーテル用チューブの一実施例を示す断面図である。
【図２】本発明のカテーテル用チューブのフレアー部を締め付け金具に装着した状態を示す断面図である。
【図３】本発明の製造装置の全体構成図である。
【図４】本発明の製造方法の第１工程を示す説明図である。
【図５】本発明の製造方法の第２工程を示す説明図である。
【図６】本発明の製造方法の第３工程を示す説明図である。
【図７】本発明の製造方法の第４工程を示す説明図である。
【図８】本発明の製造方法の第５工程を示す説明図である。
【図９】本発明のカテーテル用チューブの他の実施例を示す断面図である。
【図１０】従来の製造方法の一例を説明するための断面図である。
【図１１】従来のカテーテル用チューブ及び本発明のカテーテル用チューブのフレアー部の拡張始端から末端までの肉厚変化を示す図である。
【図１２】従来のカテーテル用チューブのフレアー部の拡張始端Ａから末端Ｂを示す図である。
【図１３】本発明のカテーテル用チューブのフレアー部の拡張始端Ａから末端Ｂを示す図である。
【図１４】従来のカテーテル用チューブのフレアー部を締め付け金具に装着した状態を示す断面図である。
【図１５】従来のカテーテル用チューブのフレアー部を締め付け金具に装着した状態を示す断面図である。
【符号の説明】
１１ カテーテル用チューブ １２ チューブ
１３ フレアー部 １４ 内側円錐面
１５ 外側円錐面 １６ 鍔部
２２ フレアー拡張体 ２３ 外金型
２４ スライドテーブル ２８ ヒーター
２９ センサー ３０ フレアー成形面
３１ チューブ案内棒 ３３ フレアー成形凹窩
３４ フレアー成形空間[0001]
[Industrial application fields]
The present invention relates to a catheter tube made of a thermoplastic synthetic resin and having a conical flared portion at one end, and a method and apparatus for manufacturing the same.
[0002]
[Prior art]
Usually, many medical catheters are composed of inner and outer double tubes, and each tube is connected to a tube for supplying a drug, a contrast agent, or the like via a conical flare provided at one end thereof. Therefore, certainty and good sealing properties are required for connecting the tubes. For this reason, the flare portion is required to have high quality and high accuracy. And the following two methods are conventionally employ | adopted for the process of such a flare part.
[0003]
As shown in FIG. 10, the first flare processing method presses one end of a tube 4 made of a thermoplastic synthetic resin by a slide table 3 against a conical flare molding surface 2 provided at the tip of the flare extension 1. The flare portion is obtained by appropriately heating and softening one end of the tube 4 with the tube heating heater 5 and the heating temperature adjusting sensor 6 embedded in the flare expansion body 1 and conically extending along the flare molding surface 2. 7 is a method of molding 7. This method has a low production cost because the apparatus is simple, and is highly reliable because the flare portion 7 is integrally formed at one end of the tube 4.
[0004]
Although the second flare processing method is not shown in the figure, it uses an injection molding method, in which a pellet-shaped thermoplastic synthetic resin is melted and fed into an injection mold at a high pressure. In this method, after forming the part, the flare part is connected to one end of the tube by an adhesive or heat welding. This method is suitable for the case where the flare appearance shape is complicated or the quality of the appearance is important because the desired flare shape can be obtained with high accuracy depending on the shape of the mold.
[0005]
[Problems to be solved by the invention]
However, the conventional flare processing method has the following problems.
In the first flare processing method, first, there is a problem that the molding temperature condition of the flare part 7 is very narrow. This will be described based on the results of a flaring experiment using the polyethylene tube shown in Table 1.
[0006]
[Table 1]

[0007]
When the set temperature is less than 70 ° C., expansion is impossible because it does not soften, and when it is 70-85 ° C., cracking occurs during expansion because of insufficient softening. On the other hand, when the set temperature exceeds 115 ° C., the flare expansion body 1 touches the flare expansion body 1 so that it is in a semi-molten state and does not expand, and becomes a dumpling on the spot.
Accordingly, the flared region is approximately 87 to 115 ° C., but the temperatures around 87 ° C. and 115 ° C. are practically unstable regions, and the temperature range in which flaring can be performed stably is 90 to 105 ° C. Further, the flare portion 7 molded at 90 to 103 ° C. has a drawback that it cannot be kept in its shape at the time of molding because it shrinks due to residual stress at the time of mold release. Therefore, the temperature range for obtaining the flare portion 7 that is satisfactory to some extent is about 104 to 105 ° C., but even in this case, the shrinkage occurred slightly.
[0008]
As described above, the problem that the molding temperature condition is extremely narrow and the shrinkage at the time of mold release is unavoidable is a highly crystalline resin, that is, a resin that rapidly softens and melts near the melting point as the temperature rises. For example, it appears more prominently in polyethylene, polypropylene, polyethylene terephthalate, polyvinyl alcohol, polyamide and the like.
[0009]
Next, there is a problem that the quality of the external shape of the molded flare portion 7 is not always sufficient. That is, in this first method, as shown in FIG. 10, one end of the tube 4 having a constant thickness is forcibly expanded into a conical shape by the flare expansion body 1, so that the flare portion 7 can be increased by increasing the surface area. As shown in FIG. 11 (conventional product), the thickness decreases from the flare expansion start end A toward the end B, and a roundness 8 is formed at the tip of the flare portion 7 as shown in FIG. The flare expansion start end A and end B of the conventional catheter tube are shown in FIG.
[0010]
As the thickness is reduced, as shown in FIG. 14, the cone angle α of the outer cone surface of the flare portion 7 is smaller than the cone angle β of the inner cone surface. This causes unevenness in the tightening of the flare portion 7 and lowers the sealing performance.
[0011]
In addition, due to the roundness 8 at the tip of the flare portion 7, as shown in FIG. 15, the area f sandwiched between the two fastening fittings 9 and 10 is the area F of the trapezoidal edge flare portion (indicated by the dotted line in the figure). The sealing performance is further reduced.
[0012]
Further, since the amount of change in the thickness of the flare portion 7 and the roundness 8 at the tip are not controlled, the shape of the flare portion is slightly different even when molded under the same conditions, and the shape of the flare is stable. It's hard to get things. Therefore, it is difficult to deal with the fastening hardware 9 and 10.
[0013]
Next, in the second flare processing method, the mold part of the injection molding machine is expensive, and the apparatus becomes large, so the production cost increases dramatically, and the flare part is made into parts. There is a problem that a connecting process is required.
In particular, the connection to the tube may be difficult to bond depending on the material. For example, when the material is polyethylene, a connection method by heat welding is employed because there is no good adhesive. However, it is difficult to obtain a sufficient adhesive force even by heat welding in a crosslinked tube or a resin with strong cohesion due to ion groups such as ionomer, and it is easy to connect the parted flare part to the tube is not. Even if the connection can be made by some method, it is inevitable that the reliability of the connection point is inferior to that in which the flare portion is integrally formed at one end of the tube by the first flare processing method.
[0014]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a catheter tube that is low in cost, high in reliability, and high in appearance quality of the flare portion.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the catheter tube of the first invention is made of a thermoplastic synthetic resin, and the catheter tube has a conical flared portion at one end of the tube. The flare portion has a uniform thickness. and the inner and outer conical surfaces are formed in parallel with each other, the cross-sectional shape is obtained by said tube formed by integrally formed with the configuration without Rutotomoni to Teisu trapezoidal edge shape, in which the flare portion through a connecting portion is there. In addition, a cylindrical flange may be formed at the tip of the flare portion in order to increase the mounting property to the tube connection fastening bracket.
[0016]
The catheter tube manufacturing method of the second invention is a method for manufacturing the catheter tube of the first invention, wherein the tube guide rod protrudes in the axial direction from the top of the conical flare molding surface. A first step in which an outer mold is fitted on the outer periphery of the flare extension body provided to form a flare molding space having a trapezoidal edge in cross section between the flare extension body and the outer mold; A second step of inserting a tube made of a plastic synthetic resin into the outer periphery of the tube guide rod and introducing it into the flare molding space; and filling the flare molding space while heating and melting the end of the introduced tube. A third step of forming the flare portion, a fourth step of fixing the shape of the flare portion by cooling and solidification after filling, and a tube having the flare portion formed at the terminal as the outer metal And it has a configuration comprising a fifth step of releasing the flare expandable body.
[0017]
Furthermore, the manufacturing apparatus for a catheter tube of the third invention is an apparatus for carrying out the manufacturing method of the second invention, and has a conical flare molding surface on the outer periphery, and the top of the flare molding surface A tube guide rod is projected in the axial direction from the inside, and a tube heating heater and a heating temperature adjustment sensor are embedded therein, so that the end of the catheter tube is filled in the flare molding space described below while heating and melting. And a hollow split mold that can be freely opened and closed, and has a flare molding recess in the hollow portion, and hugs the outer periphery of the flare extension between the flare molding recess and the flare molding surface. ingredients and outer die cross-sectional shape to form a trapezoidal edges shaped flare forming space, and a slide table which is inserted the tube on an outer periphery of the tube guide rod pushed into the flare molding space It has become to become a configuration.
[0018]
[Action]
In the present invention, since the flare portion is molded in the manner of injection molding in a conical flare molding space formed between the flare extension body and the outer mold, the flare portion has a uniform thickness and both inner and outer cones. The surfaces are formed in parallel with each other, and the cross-sectional shape thereof has the same trapezoidal edge shape as the flare molding space (see FIGS. 1 and 2 corresponding to the embodiments described later).
[0019]
Therefore, as shown in FIG. 2, when the flare portion is attached to the tube-connecting clamp, there is no uneven tightening of the clamp, and the area F sandwiched between the two clamps is the area of the conventional flare (FIG. 12 ( It is wider than f) in b). Therefore, the sealing performance is superior to the conventional flare portion.
[0020]
Moreover, since the flare part is integrally formed at one end of the tube without passing through the connection part, the reliability of the tube is high.
Furthermore, since the flare part is formed in the manner of injection molding, the quality of the external shape of the flare part is extremely high as in the case of the injection molded product.
[0021]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of a catheter tube showing an embodiment of the present invention. As shown in FIG. 1, a catheter tube 11 is integrally formed with one end of a tube 12 made of a thermoplastic synthetic resin such as low-density polyethylene without a conical flared portion 13 via a connecting portion. .
[0022]
The flare portion 13 is formed to have a uniform thickness and its inner and outer conical surfaces 14 and 15 are parallel to each other. Accordingly, the conical angles of both conical surfaces 14 and 15 are equal to each other and θ. And the cross-sectional shape of the flare part 13 is exhibiting the same trapezoid edge shape as the flare shaping | molding space 34 (FIG. 4, FIG. 5) mentioned later.
[0023]
The catheter tube 11 is extremely reliable because the flare portion 13 is formed integrally with the tube 12. Further, as shown in FIG. 2, when the flare portion 13 is mounted on the tube connecting fastening fittings 9 and 10, the flare portion 13 is formed to have a uniform thickness and the conical surfaces 14 and 15 are formed in parallel to each other. Therefore, there is no unevenness in tightening, and since the area F sandwiched between both the tightening brackets 9 and 10 is wide, the sealing performance is good.
[0024]
The catheter tube 11 can be manufactured by a manufacturing apparatus as shown in FIG. In this manufacturing apparatus, a flare extension body 22, an outer mold 23, and a slide table 24 are assembled to a support base 21.
[0025]
A front bearing 25 and a rear bearing 26 are erected on the support base 21, and a support shaft 27 is installed between the bearings 25 and 26.
The flare expansion body 22 is a brass rod-shaped body having good heat conductivity and incorporating a tube heating heater 28 and a heating temperature adjustment sensor 29, and a base portion is implanted above the front bearing 25. As shown in an enlarged view in FIG. 4, the flare extension 22 has a conical flare molding surface 30 having a cone angle θ on the outer periphery of the tip portion, and a tube guide made of stainless steel in the axial direction from the top of the flare molding surface 30. A rod 31 is projected. The flare molding surface 30 is coated with a fluorinated resin coating such as Teflon (registered trademark of du Pont) or a release agent in order to improve releasability.
[0026]
The outer mold 23 is a hollow split mold that can be freely opened and closed, and is made of Teflon that has good releasability and heat resistance. Yes. As shown in an enlarged view in FIG. 4, the outer mold 23 has a conical flare molding recess 33 having a conical angle θ in the hollow portion, and when the outer periphery of the flare expansion body 22 is held, flare molding is performed. A conical flare molding space 34 having a cone angle θ is formed between the recess 33 and the flare molding surface 30. The cross-sectional shape of the flare molding space 34 is a trapezoidal edge.
The slide table 24 is for inserting the tube 12 into the outer periphery of the tube guide rod 31 and pushing it into the flare molding space 34, and is mounted on the support shaft 27 so as to be movable in the axial direction.
[0027]
In order to manufacture the catheter tube 11 by the manufacturing apparatus, first, as shown in FIG. 4, the outer mold 23 is closed and positioned at a predetermined position with respect to the flare extension body 22 in the first step. 23 embraces the outer periphery of the flare extension 22 to form a flare molding space 34. The positioning and centering of the outer mold 23 can be easily achieved by providing a hollow in the hollow portion of the outer mold 23 that can be fitted into the cylindrical portion of the flare extension 22 as shown in the figure. .
[0028]
Next, in the second step, as shown in FIG. 3, the tube 12 is set on the slide table 24, and the flare expansion body 22 is heated to 150 ° C. by the heater 28 and the sensor 29. Subsequently, as shown in FIG. 5, the slide table 24 is moved to insert the end of the tube 12 into the outer periphery of the tube guide rod 31, and after setting the melting allowance to 20 mm, the tube 12 is moved at a speed of 40 mm / min. It is introduced into the flare molding space 34.
[0029]
In the next third step, as shown in FIG. 6, the end of the introduced tube 12 comes into contact with the flare molding surface 30 and starts to melt by heat transfer from the heater 28. The molten resin is pushed into the flare molding space 34 by the tube 12 that is continuously introduced, and the fluidity is increased by further heating, and the flare molding space 34 is filled with the pressure of the molten resin that is continuously pushed in. Then, the flare portion 13 as shown in FIG. 7 is formed.
[0030]
Next, in the fourth step, as shown in FIG. 7, the introduction of the tube 12 is stopped at the same time as the filling is completed, the tube 12 is cooled to 80 ° C. by air cooling, and the flare portion 13 in the flare molding space 34 is solidified. Fix the shape.
[0031]
In the final fifth step, as shown in FIG. 8, the outer mold 23 is opened, and the catheter tube 11 in which the flare portion 13 is formed at the end of the tube 12 is released from the outer mold 23 and the flare expansion body 22. And take it out.
The thickness of the flare portion of the obtained catheter tube 11 was uniform from the flare expansion start end A to the end B as shown in FIG. 11 (product of the present invention). The flare expansion start end A and end B of the catheter tube of the present invention are shown in FIG.
[0032]
The present inventors repeated the above operation 60 times, but were able to obtain the same quality catheter tube 11 with good reproducibility. Moreover, the flare portion 13 having a quality comparable to that of an injection molded product could be obtained. Moreover, also about temperature conditions, shaping | molding of the flare part 13 was possible in the wide range of 135-165 degreeC.
[0033]
In addition, although the shape of the flare part 13 was made into the shape as shown in FIG. 1 in a present Example, it is not necessarily limited to this, As shown in FIG. 9 as another Example, the front-end | tip of the flare part 13 is shown. Alternatively, the cylindrical flange 16 may be integrally formed. Thereby, the mounting property to the fastening fittings 9 and 10 increases.
[0034]
Furthermore, in order to make the present invention more effective, the outer mold 23 may generate heat instead of being heated by the heater 28, or these may be used in combination. The tube guide rod 31 may be tapered at the tip to facilitate insertion of the tube 12, and the material may be ceramic or hollow to reduce heat transfer from the flare extension 22. A tube may be used to release heat. Furthermore, in order to prevent the tube 12 from buckling when the tube 12 is introduced into the flare molding space 34, a cooling mechanism may be provided to cool the tube and strengthen the waist.
[0035]
【The invention's effect】
As described above, in the present invention, the end of the tube introduced into the flare molding space is heated to the melting point, and the flare portion is formed in the manner of injection molding. Thus, not leaving residual stress upon cooling and solidification of the flared portion, flared portion and the inner and outer conical surfaces in the thickness of the uniform are formed in parallel with each other, the same shape (trapezoidal edge and its cross-sectional shape flared molding space Present).
[0036]
The flare part obtained in this way is excellent because there is no uneven tightening of the tightening metal fitting when mounted on the tube fitting, and the area sandwiched between the two metal fittings is wider than the area of the conventional flare part. Excellent sealing performance.
[0037]
Moreover, since the flare part is integrally formed at one end of the tube without passing through the connection part, the reliability of the catheter tube is increased.
[0038]
Furthermore, since the flare portion is formed by injection molding, the variation in the external shape of the flare portion is dramatically improved.
[0039]
Furthermore, since the structure of the manufacturing apparatus is simple, the manufacturing cost of the catheter tube can be reduced.
[0040]
In addition, if the cylindrical collar part is formed at the tip of the flare part, the mountability of the flare part to the tube-connecting fastening metal fitting is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a catheter tube of the present invention.
FIG. 2 is a cross-sectional view showing a state in which the flared portion of the catheter tube of the present invention is attached to a fastening fitting.
FIG. 3 is an overall configuration diagram of a manufacturing apparatus according to the present invention.
FIG. 4 is an explanatory view showing a first step of the production method of the present invention.
FIG. 5 is an explanatory view showing a second step of the production method of the present invention.
FIG. 6 is an explanatory view showing a third step of the production method of the present invention.
FIG. 7 is an explanatory diagram showing a fourth step of the manufacturing method of the present invention.
FIG. 8 is an explanatory diagram showing a fifth step of the production method of the present invention.
FIG. 9 is a cross-sectional view showing another embodiment of the catheter tube of the present invention.
FIG. 10 is a cross-sectional view for explaining an example of a conventional manufacturing method.
FIG. 11 is a view showing a change in wall thickness from the start of expansion to the end of a flare portion of a conventional catheter tube and the catheter tube of the present invention.
FIG. 12 is a view showing a flared portion of a conventional catheter tube from an expansion start end A to a terminal end B.
FIG. 13 is a view showing a flared portion of the catheter tube according to the present invention from an expansion start end A to a terminal end B.
FIG. 14 is a cross-sectional view showing a state in which a flare portion of a conventional catheter tube is attached to a fastening fitting.
FIG. 15 is a cross-sectional view showing a state in which a flared portion of a conventional catheter tube is attached to a fastening fitting.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Catheter tube 12 Tube 13 Flare part 14 Inner conical surface 15 Outer conical surface 16 Ridge part 22 Flare extension body 23 Outer metal mold 24 Slide table 28 Heater 29 Sensor 30 Flare molding surface 31 Tube guide rod 33 Flare molding recess 30 Flare Molding space

Claims (4)

The catheter tube is made of a thermoplastic synthetic resin and has a conical flared portion at one end of the tube. The flare portion has a uniform thickness and both inner and outer conical surfaces are formed in parallel with each other , and the cross-sectional shape thereof is a trapezoid. It edged the Teisu Rutotomoni, catheter tube, characterized by comprising integrally formed on the tube without the flare portion through the connecting portion.   The catheter tube according to claim 1, wherein a cylindrical flange is formed at the tip of the flare portion. An outer mold is fitted on the outer periphery of a flare extension body that is formed by projecting a tube guide rod in the axial direction from the top of the conical flare molding surface, and a cross-sectional shape between the flare extension body and the outer mold Has a first step of forming a trapezoidal edge-shaped flare molding space, a second step of inserting a tube made of a thermoplastic synthetic resin into the outer periphery of the tube guide rod and introducing it into the flare molding space, and A third step of filling the flare molding space while heating and melting the end of the tube to form a flare portion; a fourth step of fixing the shape of the flare portion by cooling and solidifying after completion of filling; and a terminal And a fifth step of releasing the tube formed with the flare portion from the outer mold and the flare expansion body. A catheter having a conical flare molding surface on the outer periphery, a tube guide rod protruding in the axial direction from the top of the flare molding surface, and a tube heating heater and a heating temperature adjusting sensor embedded therein A flare expansion body for filling the later-described flare molding space while heating and melting the tube end, and a hollow split mold that can be freely opened and closed, and has a flare molding recess in the hollow portion, and the outer periphery of the flare expansion body is An outer die that forms a flare molding space having a trapezoidal edge in cross section between the flare molding recess and the flare molding surface, and a tube is inserted into the outer periphery of the tube guide rod. An apparatus for manufacturing a catheter tube, comprising: a slide table that is pushed into a forming space.

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