JPH06286005A - Production of bent pipe - Google Patents

Production of bent pipe

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Publication number
JPH06286005A
JPH06286005A JP7378093A JP7378093A JPH06286005A JP H06286005 A JPH06286005 A JP H06286005A JP 7378093 A JP7378093 A JP 7378093A JP 7378093 A JP7378093 A JP 7378093A JP H06286005 A JPH06286005 A JP H06286005A
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Prior art keywords
tube
cavity
mandrel
preform
pressure
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JP7378093A
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Japanese (ja)
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JP2910492B2 (en )
Inventor
Toshihiro Ito
Yasuhiro Nishi
Seiichi Tainaka
俊弘 伊藤
誠一 田井中
泰博 西
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Toray Ind Inc
東レ株式会社
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Abstract

PURPOSE:To produce a bent pipe such as a racket frame excellent not only in surface grade but also in physical properties. CONSTITUTION:A mandrel formed by bundling many fine CFRP wire rads is covered with a tube and a carbon fiber hellcally wound layer is formed to the periphery of the tube using a filament winding method and, subsequently, the mandrel is pulled out to form a preform. This preform is received in a lower mold having a cavity formed into a desired bent pipe shape to close the lower mold by an upper mold and a resin is injected in the cavity while pressure is applied to the interior of the tube and the cavity is reduced in pressure to be infiltrated in the helically wound layer to produce a bent pipe such as a racket frame.

Description

【発明の詳細な説明】 DETAILED DESCRIPTION OF THE INVENTION

【0001】 [0001]

【産業上の利用分野】この発明は、FRP(繊維強化プラスチック)の曲り管、特に、テニス等のラケットフレームを製造するのに適した方法に関する。 BACKGROUND OF THE INVENTION This invention, bent pipe of FRP (fiber reinforced plastics), in particular, to a method suitable for manufacturing the racquet frame of tennis and the like.

【0002】 [0002]

【従来の技術】FRPの曲り管、たとえばテニスのラケットフレームを製造する方法としては、米国特許第3, BACKGROUND ART FRP of bent pipe, as a method for producing, for example tennis racket frames, U.S. Patent No. 3,
755,037号明細書に記載されているような方法が知られている。 Methods are known as described in 755,037 Pat.

【0003】この従来の方法は、鋼線材を集束してなるマンドレルに可とう性チューブを被せ、そのチューブの周りに補強繊維のヘリカル巻層を形成した後上記マンドレルを引き抜いてプリフォームを形成し、そのプリフォームを所望のラケットフレーム形状をしたキャビティを有する下金型に入れ、上記ヘリカル巻層に樹脂を付与し、上金型を閉じた後、上記チューブ内を与圧しながら樹脂をヘリカル巻層に含浸するとともに成形するものである。 [0003] This conventional method is covered with a flexible tube to the mandrel formed by focusing the steel wire rod to form a preform withdrawn the mandrel after forming the helical wound layer of reinforcing fibers around the tube , place the preform in a lower mold having a cavity in which the desired racket frame shape, the resin was applied to the helical wound layer, after closing the upper die, the helical winding of the resin while pressurizing the inside of the tube it is intended to mold with impregnated into the layer. ところが、この方法は、下金型に入れたプリフォームのヘリカル巻層に樹脂を付与し、上金型を閉じた後、樹脂をヘリカル巻層に含浸するとともに成形するので、閉じ込められた空気が抜けきらず、得られるラケットフレームの表面にクレーター状の穴やピンホールができやすいという問題がある。 However, this method, the resin is applied to the helical wound layer of the preform, taking into lower mold, after closing the upper die, because the molded with impregnating resin in the helical winding layer, trapped air not completely missing, there is a problem of easily can crater-like holes or pinholes on the surface of the resulting racket frame. また、上金型側と下金型側とでラケットフレームの樹脂含有率に差ができやすいという問題もある。 Further, there is a problem that in the upper die side and a lower mold side easily be a difference in the resin content of the racket frame. しかるに、穴やピンホールができると表面品位が損われ、また、樹脂含有率に差ができると物性が低下したり重量バランスがくずれたりする。 However, the surface quality is impaired when it is a hole or a pin hole, also physical properties when it is a difference in the resin content or collapse the weight balance lowered.

【0004】 [0004]

【発明が解決しようとする課題】この発明の目的は、従来の方法の上述した問題点を解決し、表面品位に優れるばかりか、物性に優れた曲り管を製造する方法を提供するにある。 OBJECTS OF THE INVENTION It is an object of this invention is to solve the aforementioned problems of the conventional method, not only excellent surface quality, is to provide a method of manufacturing a bent pipe having excellent physical properties.

【0005】 [0005]

【課題を解決するための手段】上記目的を達成するために、この発明は、複数本のFRP線材を集束してなるマンドレルに可とう性チューブを被せ、そのチューブの周りにフィラメントワインディング法を用いて補強繊維のヘリカル巻層を形成した後上記マンドレルを引き抜いてプリフォームを形成し、そのプリフォームを所望の曲り管形状をしたキャビティを有する下金型に入れて上金型を閉じ、上記チューブ内を与圧しながら、かつ、上記キャビティ内を減圧しながらそのキャビティ内に樹脂を注入して上記ヘリカル巻層に含浸し、成形することを特徴とする、曲り管の製造方法を提供する。 To achieve the above object of the Invention The, present invention is covered with a flexible tube to the mandrel formed by focusing a plurality of FRP wire, using a filament winding process around the tube to form a preform withdrawn the mandrel after forming the helical wound layer of reinforcing fibers Te, close the upper mold and put the preform into a lower mold having a cavity in which the desired bent pipe shape, the tube while pressurizing the inner and by injecting resin into the cavity while reducing the pressure in the cavity is impregnated with the helical wound layer, characterized by forming, to provide a method of manufacturing a bent pipe.

【0006】また、この発明は、上述した方法を使用したラケットフレームの製造方法として、複数本のFRP Further, the present invention is, as a manufacturing method of the racket frame using the method described above, a plurality of FRP
線材を集束してなるマンドレルに可とう性チューブを被せ、そのチューブの周りにフィラメントワインディング法を用いて補強繊維のヘリカル巻層を形成した後上記マンドレルを引き抜いてプリフォームを形成し、そのプリフォームを所望のラケットフレーム形状をしたキャビティを有する下金型に入れて上金型を閉じ、上記チューブ内を与圧しながら、かつ、上記キャビティ内を減圧しながらそのキャビティ内に樹脂を注入して上記ヘリカル巻層に含浸し、成形することを特徴とする、ラケットフレームの製造方法を提供する。 Covered with a flexible tube to the mandrel formed by focusing the wire, to form a preform withdrawn the mandrel after forming the helical wound layer of reinforcing fibers with a filament winding process around the tube, the preform the closed upper die placed in a lower mold having a cavity in which the desired racket frame shape, while pressurized within the tube, and by injecting resin into the cavity while reducing the pressure in the cavity above impregnating the helical wound layer, characterized by forming, to provide a method of manufacturing a racquet frame.

【0007】上記いずれの方法においても、好ましくは、成形時にチューブ内の圧力をやや上昇させる。 [0007] In any of the above methods, preferably, slightly raise the pressure in the tube during molding.

【0008】この発明においては、FRP線材、好ましくは、CFRP(炭素繊維強化プラスチック)からなる太さ3〜5mm程度の線材を所望の本数集束してなるマンドレルを使用する。 [0008] In this invention, FRP wire, preferably using a mandrel CFRP a wire of about the thickness 3~5mm consisting (CFK) formed by focusing a desired number. 線材がばらばらにならないように、 So that the wire does not fall apart,
たとえば両端部を結えてもよい。 For example, it may be tied off at both ends. この発明が、フィラメントワインディング法において普通に使用されている棒状や筒状の鋼製マンドレル等を使用しないのは、そのようなマンドレルは引抜きが容易でないために引抜き時にマンドレルの端部でチューブに傷を付けやすいからである。 The present invention is, not to use the normal rod-like or tubular in use steel mandrel or the like in a filament winding method, scratches on the tube at the end of the mandrel during withdrawal for such mandrels are not easy pulling the it is because easy to attach. また、上述した米国特許第3,755,037号発明が使用しているような鋼線材を集束してなるマンドレルを使用しないのは、鋼線材は比剛性が低いためにマンドレルのたわみが大きく、マンドレルを緊張下に保持しなければヘリカル巻層の安定した形成が容易でないからである。 Also, not to use a mandrel which is formed by focusing the steel wires as described above U.S. Patent No. 3,755,037 invention is using the steel wire has a large deflection of the mandrel due to the low specific rigidity, if you are holding the mandrel under tension because stable formation of the helical wound layer is not easy.

【0009】この発明においては、次に、上記マンドレルに、可とう性のチューブ、たとえばゴムチューブやナイロンチューブを被せ、そのチューブの周りに、フィラメントワインディング法を用いて、補強繊維、たとえば炭素繊維やガラス繊維、ポリアラミド繊維を、その方向がマンドレルの軸方向に対して好ましくは±7〜75゜の範囲になるようにヘリカル巻し、任意の厚みのヘリカル巻層を形成する。 [0009] In this invention, then, to the said mandrel, flexible tubing, for example covered with a rubber tube or a nylon tube, around the tube, using a filament winding method, Ya reinforcing fibers, such as carbon fibers glass fibers, polyaramid fibers, that direction preferably helical winding to be ± seven to seventy-five DEG with respect to the axial direction of the mandrel to form the helical wound layer of arbitrary thickness. 補強繊維は、ストランドの形態であってもよく、テープの形態であってもよい。 Reinforcing fibers may be in the form of strands may be in the form of a tape. また、巻角度が7゜よりも小さいと補強繊維の配列の安定性が低下し、また、75゜を超えると締付け力が強くなって後のマンドレルの引抜きが難しくなる。 Moreover, decreased stability of the arrangement of reinforcing fibers and winding angle is less than 7 ° is also pulling the mandrel is difficult after so strong tightening force exceeding 75 °. さらに、補強繊維は50〜200gの力を加えながら巻き付けるのがよい。 Furthermore, the reinforcing fibers are good to wound while applying a force of 50 to 200 g.

【0010】ヘリカル巻層の形成が終わると、マンドレルを引き抜く。 [0010] the formation of the helical winding layer is finished, pull out the mandrel. これによって、可とう性チューブの周りに補強繊維のヘリカル巻層が形成されたプリフォームが得られる。 Thus, the preform helical wound layer of reinforcing fibers are formed around the flexible tube is obtained.

【0011】次に、上記プリフォームを、所望の曲り管形状、たとえばラケットフレームの形状をしたキャビティを有する下金型に曲げながら入れる。 [0011] Then, the preform is placed while bending desired bent pipe shape, for example, the lower mold having a cavity in the shape of the racquet frame. このとき、後のチューブ内の与圧の必要から、チューブの一端部を緊縛するなどして閉塞するとともに、他端部に圧力空気等の導入用カプラーを取り付けておく。 In this case, the need for pressurized in the tube after, as well as closed, such as by tied one end of the tube, have been installed for introduction couplers such as pressure air to the other end.

【0012】次に、上金型を閉じ、可とう性チューブ内に圧力1〜2kgf /cm 2の圧力空気を導入してチューブ内を与圧しながら、かつ、キャビティ内を減圧しながら、キャビティ内に、エポキシ樹脂や不飽和ポリエステル樹脂、ビニルエステル樹脂、フェノール樹脂等の熱硬化性樹脂や、ナイロン樹脂、ポリエステル樹脂、ポリエチレン樹脂等の熱可塑性樹脂を加圧注入し、ヘリカル巻層に含浸するとともに成形する。 [0012] Next, close the upper mold, while pressurized within the tube by introducing pressure air at a pressure 1~2kgf / cm 2 in the flexible tube, and while reducing the pressure in the cavity, the cavity to, epoxy resins and unsaturated polyester resins, vinyl ester resins, and thermosetting resins such as phenol resin, nylon resin, polyester resin, a thermoplastic resin such as polyethylene resin is injected under pressure, as well as impregnating the helical wound layer molding to. 樹脂は、成形品中のボイドを低減するために、注入前に脱泡処理しておくのが好ましい。 Resin, in order to reduce the voids in the molded article, preferably keep defoamed prior to injection. また、樹脂の注入圧力は、チューブ内の圧力と同じでは注入が難しいのでそれよりも高いほうがよいが、あまり高くすると補強繊維の配列が乱れることがあるので、チューブ内の圧力よりも1〜2kgf /cm 2ほど高い3〜4kgf /cm 2の範囲にするのが好ましい。 1~2kgf Further, the injection pressure of the resin is the same as the pressure in the tube is better higher than that because injection is difficult, because it may disturbed sequence of the reinforcing fibers is too high, than the pressure in the tube preferably in the range of / cm 2 higher 3~4Kgf / cm 2. さらに、成形時に可とう性チューブ内の圧力を5〜6kgf / Furthermore, the pressure in the flexible tube during molding 5~6Kgf /
cm 2に上げると、過剰の樹脂を絞り出すことができて補強繊維の含有率が上がったり、肉厚の均一性が向上して物性のより優れた曲り管を得ることができるようになる。 By lifting cm 2, go up the content of the reinforcing fibers are able to squeeze out excess resin, the uniformity of the wall thickness it is possible to obtain a better bend tubes with improved physical properties.

【0013】 [0013]

【実施例】太さ5mm、長さ2,000mmのCFRP線材8本を集束してなるマンドレルにナイロンチューブを被せ、そのナイロンチューブの周りにフィラメントワインディング法を用いて炭素繊維のヘリカル巻層(内層:± EXAMPLES thickness 5 mm, covered with a nylon tube to the mandrel formed by focusing the CFRP wires eight length 2,000 mm, the helical wound layer of carbon fibers with a filament winding process around the nylon tube (inner layer : ±
15゜層×3層、外層:±60゜層×1層、全体厚み: 15 ° layer × 3 layers, outer layer: ± 60 ° layers × 1 layer, total thickness:
1.2mm)を形成した後、マンドレルを引き抜いてプリフォームを得た。 After forming the 1.2 mm), to obtain a preform pull out the mandrel.

【0014】次に、このプリフォームをラケットフレームの形状をしたキャビティを有する割り金型の下金型に入れ、上金型を閉じ、ナイロンチューブ内に1kgf /cm [0014] Next, put this preform into the lower mold of the split mold having a cavity in the shape of the racquet frame, close the upper mold, 1 kgf / cm in the nylon tube
2の圧力空気を導入してそのナイロンチューブ内を与圧しながら、かつ、上金型に設けた吸引口から吸引してキャビティ内を700Torrに減圧しながら、上金型に設けた樹脂注入口から3kgf /cm 2の圧力でキャビティ内にビニルエステル樹脂を注入してヘリカル巻層に含浸し、 While pressurized within the nylon tube to introduce second pressure air, and was suction from a suction port provided in the upper mold cavity while reducing the pressure to 700 Torr, the resin injection port provided in the upper die at a pressure of 3 kgf / cm 2 by injecting vinyl ester resin into the cavity to impregnate the helical wound layer,
ビニルエステル樹脂が吸引口に達した時点で注入を止め、100℃で10分加熱してビニルエステル樹脂を硬化させた後脱型し、さらに130℃で2時間のアフターキュア処理を施してラケットフレームを得た。 Stopping the infusion at the time the vinyl ester resin has reached the suction port, and heated 10 minutes at 100 ° C. demolded after curing the vinyl ester resin, the racket frame is subjected to after-curing for 2 hours at 130 ° C. It was obtained.

【0015】このラケットフレームの表面を観察したところ、クレーター状の穴やピンホールは認められず、表面品位が大変優れていた。 [0015] The observation of the surface of the racket frame, crater-like hole and pin hole is not observed, the surface quality was very excellent. また、数か所について横断面を観察したが、炭素繊維やビニルエステル樹脂の分布、 Further, although the observed cross sections for several places, carbon fiber and vinyl ester resin distribution,
肉厚は極めて均一であった。 Wall thickness was very uniform.

【0016】 [0016]

【発明の効果】この発明は、複数本のFRP線材を集束してなるマンドレルに可とう性チューブを被せ、そのチューブの周りにフィラメントワインディング法を用いて補強繊維のヘリカル巻層を形成した後上記マンドレルを引き抜いてプリフォームを形成し、そのプリフォームを所望の曲り管形状をしたキャビティを有する下金型に入れて上金型を閉じ、上記チューブ内を与圧しながら、かつ、上記キャビティ内を減圧しながらそのキャビティ内に樹脂を注入して上記ヘリカル巻層に含浸し、成形するので、実施例にも示したように、表面品位に優れ、また、補強繊維や樹脂の分布が均一で、肉厚も均一な、物性に優れた曲り管を得ることができるようになる。 Effects of the Invention The present invention, covered with a flexible tube to the mandrel formed by focusing a plurality of FRP wire, the after forming a helical winding layer of the reinforcing fibers with a filament winding process around the tube to form a preform withdrawn mandrel, close the upper mold and put the preform into a lower mold having a cavity in which the desired bent pipe shape, while pressurized within the tube, and the inside of the cavity by injecting resin into the cavity while reducing the pressure impregnated with the helical wound layer, since the molding, as also shown in the examples, excellent surface quality, also has a uniform distribution of the reinforcing fibers and the resin, thicker uniform, it becomes possible to obtain a bent pipe having excellent physical properties. しかも、複数本のFRP線材を集束してなるマンドレルを使用するので、その抜取りが容易であるばかりか、FRP Moreover, because it uses a mandrel formed by focusing a plurality of FRP wire, not only that extraction is easy, FRP
線材は米国特許第3,755,037号発明が使用しているような鋼線材にくらべて比剛性が高いために緊張下に保持しなくてもヘリカル巻層の安定した形成が容易になり、この面からも補強繊維や樹脂の分布が均一で、肉厚も均一な、物性に優れた曲り管を得ることができるようになる。 Wire is easier to stably form the helical wound layer without holding under tension due to the high specific rigidity as compared with steel wires, such as those used by the invention U.S. Pat. No. 3,755,037, also uniform distribution of the reinforcing fibers and resin from the surface, thicker uniform, it becomes possible to obtain a bent pipe having excellent physical properties.

フロントページの続き (51)Int.Cl. 5識別記号 庁内整理番号 FI 技術表示箇所 // B29L 31:52 4F Front page continued (51) Int.Cl. 5 in identification symbol Agency Docket No. FI art display portion // B29L 31:52 4F

Claims (4)

    【特許請求の範囲】 [The claims]
  1. 【請求項1】複数本のFRP線材を集束してなるマンドレルに可とう性チューブを被せ、そのチューブの周りにフィラメントワインディング法を用いて補強繊維のヘリカル巻層を形成した後上記マンドレルを引き抜いてプリフォームを形成し、そのプリフォームを所望の曲り管形状をしたキャビティを有する下金型に入れて上金型を閉じ、上記チューブ内を与圧しながら、かつ、上記キャビティ内を減圧しながらそのキャビティ内に樹脂を注入して上記ヘリカル巻層に含浸し、成形することを特徴とする、曲り管の製造方法。 1. A covered with a flexible tube to the mandrel formed by focusing a plurality of FRP wire, pull out the said mandrel after forming a helical winding layer of the reinforcing fibers with a filament winding process around the tube forming a preform, closing the upper mold and put the preform into a lower mold having a cavity in which the desired bent pipe shape, while pressurized within the tube, and, while reducing the pressure in the cavity thereof the resin injection to impregnating the above helical winding layer in the cavity, wherein the molding method for manufacturing a bent pipe.
  2. 【請求項2】成形時にチューブ内の圧力を上昇させることを特徴とする、請求項1の曲り管の製造方法。 Wherein characterized in that to increase the pressure in the tube during molding method for producing a bent tube according to claim 1.
  3. 【請求項3】複数本のFRP線材を集束してなるマンドレルに可とう性チューブを被せ、そのチューブの周りにフィラメントワインディング法を用いて補強繊維のヘリカル巻層を形成した後上記マンドレルを引き抜いてプリフォームを形成し、そのプリフォームを所望のラケットフレーム形状をしたキャビティを有する下金型に入れて上金型を閉じ、上記チューブ内を与圧しながら、かつ、 3. A covered with a flexible tube to the mandrel formed by focusing a plurality of FRP wire, pull out the said mandrel after forming a helical winding layer of the reinforcing fibers with a filament winding process around the tube forming a preform, closing the upper mold and put the preform into a lower mold having a cavity in which the desired racket frame shape, while pressurized within the tube, and,
    上記キャビティ内を減圧しながらそのキャビティ内に樹脂を注入して上記ヘリカル巻層に含浸し、成形することを特徴とする、ラケットフレームの製造方法。 By injecting resin into the cavity while reducing the pressure in the cavity is impregnated with the helical wound layer, characterized by forming method of the racket frame.
  4. 【請求項4】成形時にチューブ内の圧力を上昇させることを特徴とする、請求項3のラケットフレームの製造方法。 4., characterized in that to increase the pressure in the tube during molding method for producing a racquet frame according to claim 3.
JP7378093A 1993-03-31 1993-03-31 Method of manufacturing a bent pipe Expired - Lifetime JP2910492B2 (en)

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JPH06286005A true true JPH06286005A (en) 1994-10-11
JP2910492B2 JP2910492B2 (en) 1999-06-23

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06182010A (en) * 1992-06-19 1994-07-05 Mizuno Corp Frp bat
US5897447A (en) * 1996-04-02 1999-04-27 Toray Industries, Inc. FRP racket and method for producing the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3755037A (en) * 1971-01-18 1973-08-28 Dayton Scale Model Co Method of making a fiber reinforced racket
JPS5432577A (en) * 1977-08-17 1979-03-09 Okayama Sekisui Kogyo Kk Molding of reinforced resin tube
JPS6292833A (en) * 1985-10-19 1987-04-28 Nitto Boseki Co Ltd Manufacture of bent continuous fiber reinforced resin tube

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3755037A (en) * 1971-01-18 1973-08-28 Dayton Scale Model Co Method of making a fiber reinforced racket
JPS5432577A (en) * 1977-08-17 1979-03-09 Okayama Sekisui Kogyo Kk Molding of reinforced resin tube
JPS6292833A (en) * 1985-10-19 1987-04-28 Nitto Boseki Co Ltd Manufacture of bent continuous fiber reinforced resin tube

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06182010A (en) * 1992-06-19 1994-07-05 Mizuno Corp Frp bat
US5897447A (en) * 1996-04-02 1999-04-27 Toray Industries, Inc. FRP racket and method for producing the same

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