JPS60190311A - Manufacture of frp pipe - Google Patents

Abstract

PURPOSE:To obtain an FRP pipe without causing any interlayer cracks by a method in which a laminated resin wound around an iron core is hardened by heating with a temperature gradient in the thickwise direction from the inside to the outside of the laminated resin by electrically energizing the iron core with an induction coil. CONSTITUTION:For example, a pre-preg or a reinforcing material is wound around an iron core 4 and impregnated with a resin under vacuum condition to form a laminate. The laminate is put in a cylindrical induction coil 6, and AC voltage of commercial frequency is applied to the induction coil terminal 7 to energize the coil electrically. The resin of the laminate is hardened by heating with a temperature gradient in the thickwise direction of the laminate by the heat of the iron core 4 in such a way that the inside of the laminate becomes higher temperatures and the outside becomes lower temperatures in order to obtain an aimed product.

Description

【発明の詳細な説明】 本発明はＦＲＰバイブの製造法に関する。ＦＲＰバイブ
は鉄芯に熱硬化性樹脂を用いたプリプレグを巻きつけた
積層物を外部から加熱して硬化させるか又は鉄芯に補強
材を巻きつけてから熱硬化性樹脂を真空含浸してから外
部から加熱硬化して製造するのが普通である。このよう
な積層物の樹脂の硬化方法では樹脂の硬化が外周部から
起こるため肉厚のＦＲＰパイプを製造すると樹脂の硬化
収縮により応力が発生し第１図に示すようなりラック３
が発生しやすい欠点がある。これを防止するには積層物
の樹脂硬化をゆるやかにして内部応力の低減をはかるこ
とが必要である。そのため加熱硬化温度を低くし長時間
加熱する手段を取っている。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an FRP vibe. FRP vibes are made by wrapping a laminate of prepreg made of thermosetting resin around an iron core and curing it by heating from the outside, or by wrapping a reinforcing material around the iron core and vacuum impregnating it with thermosetting resin. It is usually manufactured by heating and curing from the outside. In this method of curing resin for laminates, the resin hardens from the outer periphery, so when a thick FRP pipe is manufactured, stress is generated due to curing and shrinkage of the resin, resulting in rack 3 as shown in Figure 1.
There is a drawback that it is easy to occur. To prevent this, it is necessary to slow down the resin curing of the laminate to reduce internal stress. Therefore, measures are taken to lower the heat curing temperature and heat for a long time.

また、ＦＲＰパイプを製造する際積層物の樹脂硬化を外
部加熱によシおこなうと層間にクラック３が発生するの
は樹脂の硬化が内外部から起こるため第２図に示すよう
にＦＲＰパイプの半径方向で外へ向う応力５と内へ向か
う応力５′が発生し。In addition, when manufacturing FRP pipes, when the resin of the laminate is cured by external heating, cracks 3 occur between the layers because the resin hardens from the inside and outside, and as shown in Figure 2, the radius of the FRP pipe An outward stress 5 and an inward stress 5' are generated in the direction.

そのため層間でクラック３が発生しやすくなる。Therefore, cracks 3 are likely to occur between the layers.

これを防止するためには成形時に、外部加熱をやめ内部
加熱をすればよいが、内部加熱をすると第３図に示すよ
うに樹脂の硬化収縮によりＦＲ，Ｐパイプ半径方向で内
へ向う応力５′が発生する。To prevent this, it is possible to stop external heating and start internal heating during molding, but if internal heating is used, as shown in Figure 3, the stress 5 will be directed inward in the radial direction of the FR and P pipes due to curing and shrinkage of the resin. ' occurs.

第１〜３図において１はＦＲ，Ｐパイプ、２は積層物、
４は鉄芯である。また補強材は鉄芯に巻きつけているの
で半径方向で内へ向う応力には追従して動くことができ
るので層間方向のクラックを発生させる応力にはならな
い。In Figures 1 to 3, 1 is FR, P pipe, 2 is laminate,
4 is an iron core. In addition, since the reinforcing material is wrapped around the iron core, it can move inwardly in the radial direction to follow the stress, so the stress does not cause cracks in the interlayer direction.

本発明は、ＰＲ，Ｐパイプを製造する際に誘導加熱性に
より内部加熱をおこない層間クラックを防止することを
目的とするものである。The present invention aims to prevent interlayer cracks by performing internal heating by induction heating when manufacturing PR and P pipes.

本発明は、鉄芯に巻いた積層物の樹脂の硬化をおこなう
際に、誘導コイルを用いて鉄芯にうず電流を流しこれに
よる発熱を利用して積層物の厚さ方向に温度勾配をつけ
て、積層物の樹脂の硬化を行なうＦＲＰバイブの製造法
に関する。In the present invention, when curing the resin of a laminate wound around an iron core, an eddy current is passed through the iron core using an induction coil, and the resulting heat is used to create a temperature gradient in the thickness direction of the laminate. The present invention relates to a method for manufacturing an FRP vibe in which resin of a laminate is cured.

鉄芯のうず電流の発生は、誘導が熱性によって行なわれ
る。誘導加熱法は第４図に示す円筒状の誘導コイル６を
用いる。７は誘導コイルの端子である。このコイル内に
鉄芯にプリプレグ又は補強材を巻き樹脂を真空含浸した
積層物を第５図に示すように入れる。その後コイルに商
用周波の交流電圧を印加しコイルに電流を流す。コイル
に電流を流すと電磁誘導作用によりコイルの中に入れた
鉄芯にうず電流が流れ鉄芯の抵抗によるオーム損失が発
生し鉄芯が発熱する。この発熱により積層物の内側が高
温、外側が低温となり、積層物に温度勾配ができ積層物
の樹脂の硬化が鉄芯の表面（ＦＲＰパイプの内面）から
起こり前記の効果が発揮されて層間クラックを防止でき
る。積層物の厚さ方向の温度勾配は例えば第６図の曲線
９のようにされる。横軸は積層物の厚さを示す。The generation of eddy currents in the iron core is caused by thermal induction. The induction heating method uses a cylindrical induction coil 6 shown in FIG. 7 is the terminal of the induction coil. A laminate in which prepreg or reinforcing material is wrapped around an iron core and vacuum impregnated with resin is placed inside this coil as shown in FIG. After that, a commercial frequency AC voltage is applied to the coil, causing current to flow through the coil. When a current is passed through the coil, an eddy current flows through the iron core placed inside the coil due to electromagnetic induction, causing ohmic loss due to the resistance of the iron core, causing the iron core to generate heat. This heat generation causes the inside of the laminate to be high temperature and the outside to be low temperature, creating a temperature gradient in the laminate, causing the resin in the laminate to harden from the surface of the iron core (inner surface of the FRP pipe), producing the above effect and causing interlayer cracks. can be prevented. The temperature gradient in the thickness direction of the laminate is, for example, as shown by curve 9 in FIG. The horizontal axis indicates the thickness of the laminate.

本発明の積層物には熱硬化性樹脂組成物が用いられるが
、その材料９組成等には制限はない。Although a thermosetting resin composition is used in the laminate of the present invention, there are no restrictions on the material 9 composition, etc.

本発明の詳細な説明する。The present invention will be described in detail.

実施例１ 第４図に示す形状の２ｋＶＡの誘導コイル（内径１００
薗、長さ１０００ｍ、巻数２５０ターン）を用いこのコ
イル内に第５図に示すように、エポキシ樹脂組成物を含
浸した厚さ０．２　ｍｍ　、幅１０００ｍｍ、長さ１０
００ｍｍのガラスクロス（日東紡製、目抜平織ガラスク
ロスＷＥ−３５ＢＸ’）のプリプレグを直径３０口の鉄
芯に１００回きつく巻き外径７０ｍｍにした積層物２を
入れた。これに５０Ｈｚの交流電圧を印加して鉄芯にう
ず電流を発生させた。印加電圧を調節して鉄芯表面の温
度（ＦＴＬＰパイプ内面の温度）を１２０℃に保ち３時
間放置してプリプレグを硬化させた。この時のＰＲ，Ｐ
パイプ内面の温度は１２０℃外面の温度は１０８℃で積
層物の温度勾配は第６図の９のようになり、プリプレグ
の硬化は内面から起こり層間クラックは発生しなかった
。積層物内の内部温度は、所定の位置に直径０．２ｗｎ
の熱電対（銅−コンスタンタン）を埋め込んで測定した
。用いたエポキシ樹脂組成物は、ビスフェノール系エポ
キシ樹脂、エビコー）１００１（シェル石油社製）１０
０重Ｉ・部、三弗化ホウ素モノエチルアミン、　ＢＦｓ
　４００　（橋本化学社製）３重量部およびメチルエチ
ルケトン３０重量部の混合物とした。Example 1 A 2 kVA induction coil (inner diameter 100
As shown in Fig. 5, a coil with a thickness of 0.2 mm, a width of 1000 mm, and a length of 10 is impregnated with an epoxy resin composition.
A laminate 2 in which a prepreg of glass cloth (manufactured by Nittobo, open weave glass cloth WE-35BX') of 0.00 mm was tightly wound 100 times around an iron core with a diameter of 30 to give an outer diameter of 70 mm was placed. An alternating current voltage of 50 Hz was applied to this to generate an eddy current in the iron core. The applied voltage was adjusted to keep the temperature of the iron core surface (temperature of the inner surface of the FTLP pipe) at 120° C., and the prepreg was left to stand for 3 hours to cure the prepreg. PR at this time, P
The temperature of the inner surface of the pipe was 120° C. The temperature of the outer surface was 108° C., and the temperature gradient of the laminate was as shown in 9 in FIG. 6. The prepreg hardening occurred from the inner surface and no interlayer cracks occurred. The internal temperature within the laminate is 0.2wn in diameter in place.
Measurements were made by embedding a thermocouple (copper-constantan). The epoxy resin composition used was a bisphenol-based epoxy resin, Ebicor) 1001 (manufactured by Shell Oil Company) 10
0 parts I, boron trifluoride monoethylamine, BFs
A mixture of 3 parts by weight of 400 (manufactured by Hashimoto Chemical Co., Ltd.) and 30 parts by weight of methyl ethyl ketone was prepared.

比較例１ 実施例１と同じ誘導コイル内に実施例１と同じプリプレ
グを用いて実施例１と同様にして積層物を入れ、これを
１２０℃の恒温槽に入れ３時間加熱硬化させた。その結
果ＦＲ，Ｐバイブに層間クラックが発生した。なおＰＲ
，Ｐバイブの加熱硬化時の温度分布はＦＲ，Ｐパイプ内
面は１１５℃ＦＲＰパイプ外面１１９℃であり積層物の
温度勾配は第６図の８のようになり、内面、外面の温度
差が少なくプリプレグの硬化が外面と内面両方から起と
５− りＦＲＰバイブの厚さ方向中央部分でクラックが発生す
る原因となった。Comparative Example 1 A laminate was placed in the same induction coil as in Example 1 using the same prepreg as in Example 1 in the same manner as in Example 1, and the laminate was placed in a thermostat at 120° C. and cured by heating for 3 hours. As a result, interlayer cracks occurred in the FR and P vibes. Furthermore, PR
, The temperature distribution during heat curing of the P-vib is 115°C for the inner surface of the FR P pipe and 119°C for the outer surface of the FRP pipe, and the temperature gradient of the laminate is as shown in 8 in Figure 6, with little temperature difference between the inner and outer surfaces. The prepreg hardened from both the outer and inner surfaces, causing cracks to occur in the center of the FRP vibrator's thickness.

本発明の製造法により、ＦＲＰパイプを内部から加熱す
ると層間クラックを発生させることなくかつ従来法より
短時間で成形できる。さらに従来法よりも肉厚のパイプ
（内径に外径の比が４）を製造することも可能である。According to the manufacturing method of the present invention, when an FRP pipe is heated from the inside, it can be formed in a shorter time than conventional methods without generating interlayer cracks. Furthermore, it is also possible to manufacture thicker pipes (ratio of inner diameter to outer diameter of 4) than with conventional methods.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はＦＲ，Ｐバイブの断面図でクラックの発生を示
す図、第２図は従来法により加熱硬化したときの樹脂硬
化収縮により内外に向かう応力を示す図、第３図は本発
明により内部から加熱したときの樹脂収縮により内に向
かう応力を示す図、第４図は本発明に使用する誘導コイ
ルの外形図、第５図は本発明の実施方法を示す図及び第
６図は実施例、比較例における積層物の温度勾配を示す
図である。 符号の説明 １・・・ＦＢ、Ｐバイブ　２・・・積層物３・・・クラ
ック　４・・・鉄芯 ６一 ５．５′・・・樹脂硬化により発生する応力６・・・誘
導コイル　７・・・誘導コイルの端子７−Fig. 1 is a cross-sectional view of the FR, P vibe, showing the occurrence of cracks, Fig. 2 is a drawing showing the stress directed inward and outward due to resin curing shrinkage when heated and cured by the conventional method, and Fig. 3 is a diagram showing the stress directed inward and outward due to resin curing shrinkage when heated and cured by the conventional method. A diagram showing inward stress due to resin contraction when heated from the inside, Figure 4 is an outline diagram of the induction coil used in the present invention, Figure 5 is a diagram showing the method of implementing the present invention, and Figure 6 is a diagram showing the method of implementation It is a figure which shows the temperature gradient of the laminated material in an example and a comparative example. Explanation of symbols 1...FB, P vibe 2...Laminated product 3...Crack 4...Iron core 6-5.5'...Stress generated by resin curing 6...Induction coil 7 ...Induction coil terminal 7-

Claims (1)

【特許請求の範囲】[Claims] １、鉄芯に巻いた積層物の樹脂の硬化をおこなう際に、
誘導コイルを用いて鉄芯にうず電流を流し、これによる
発熱を利用して積層物の厚さ方向に温度勾配をつけて、
積層物の樹脂の硬化を行なうことを特徴とするＦＲＰパ
イプの製造法。1. When curing the resin of the laminate wrapped around the iron core,
An eddy current is passed through the iron core using an induction coil, and the heat generated by this is used to create a temperature gradient in the thickness direction of the laminate.
A method for producing an FRP pipe, characterized by curing the resin of the laminate.