JP2001076549A - Fire-resistant electric cable and its manufacturing method - Google Patents
Fire-resistant electric cable and its manufacturing methodInfo
- Publication number
- JP2001076549A JP2001076549A JP24670299A JP24670299A JP2001076549A JP 2001076549 A JP2001076549 A JP 2001076549A JP 24670299 A JP24670299 A JP 24670299A JP 24670299 A JP24670299 A JP 24670299A JP 2001076549 A JP2001076549 A JP 2001076549A
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- Japan
- Prior art keywords
- layer
- fire
- extruded insulator
- tape
- resistant
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、部分放電特性等の
電気特性に優れた耐火電線およびその製造方法に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refractory wire having excellent electrical characteristics such as partial discharge characteristics and a method for producing the same.
【０００２】[0002]
【従来の技術】ビル用配線、各種消防設備や警報設備の
給電線等に耐火電線が多く用いられている。代表的な耐
火電線は、図６に示すように、導体１上にガラスマイカ
テープ等の耐火テープを巻付けてなる耐火層２、押え巻
層３、押出絶縁体４、半導電層５、遮蔽層６、押え巻層
７およびシース８を順に設けて構成される（３芯構造の
場合は、これを３芯撚合せて構成される）。そのうち、
押え巻層３は、耐火層２の外表面のけばだち、押出絶縁
体４との界面不整を防止するために、耐火層２の上にポ
リエステルテープを１／２ラップ巻きして形成され、押
出絶縁体４は例えば有機過酸化物等の架橋剤を配合した
未架橋ポリエチレン材料を加圧下で押出被覆すると共
に、加圧下で２００℃以上の高温に加熱して架橋処理
し、加圧冷却する化学架橋方式により形成されるもので
ある。2. Description of the Related Art Fireproof electric wires are often used for wiring for buildings, power supply lines for various firefighting equipment and alarm equipment, and the like. As shown in FIG. 6, a typical fire-resistant electric wire includes a fire-resistant layer 2 formed by winding a fire-resistant tape such as a glass mica tape on a conductor 1, a holding layer 3, an extruded insulator 4, a semiconductive layer 5, and a shield. It is configured by sequentially providing the layer 6, the presser winding layer 7, and the sheath 8 (in the case of a three-core structure, it is configured by twisting three cores). Of which
The presser winding layer 3 is formed by winding a polyester tape on the refractory layer 2 in a 1/2 wrap manner in order to prevent fuzz on the outer surface of the refractory layer 2 and irregular interface with the extruded insulator 4. The extruded insulator 4 is, for example, extruded and coated with an uncrosslinked polyethylene material containing a crosslinking agent such as an organic peroxide under pressure, and is heated to a high temperature of 200 ° C. or more under pressure to perform a crosslinking treatment, It is formed by the chemical crosslinking method described below.
【０００３】[0003]
【発明が解決しようとする課題】耐火電線の押出絶縁体
４を化学架橋方式で架橋して形成した場合には、架橋設
備が大型化して、電線の製造コストが高くなるという問
題がある。この問題を解決するため、最近、耐火電線の
押出絶縁体４をシラン架橋方式、即ち、有機シラン化合
物及び有機過酸化物を配合した未架橋ポリエチレン材料
を大気圧下で押出被覆して冷却し、その後、これを６０
〜８０℃の温水中で触媒の作用のもとに架橋処理する方
式により形成し、設備の小型化、電線製造コストの低減
化を図ろうとする試みが進んでいる。When the extruded insulator 4 of a fire-resistant wire is formed by crosslinking by a chemical crosslinking method, there is a problem that the crosslinking equipment becomes large and the manufacturing cost of the wire increases. In order to solve this problem, recently, the extruded insulator 4 of the refractory wire is cooled by extruding an uncrosslinked polyethylene material containing an organic silane compound and an organic peroxide under atmospheric pressure, and cooling it. Then, add this to 60
Attempts have been made to form the structure by a method of performing a crosslinking treatment under the action of a catalyst in warm water of up to 80 ° C. to reduce the size of equipment and the cost of manufacturing electric wires.
【０００４】しかしながら、このようなシラン架橋方式
により電線の押出絶縁体４を形成すると、上記押出被覆
材料の押出時の熱で、耐火層２内に含まれる空気その他
の気体が熱膨張して、押えテープ巻層３を構成する押え
テープの重ね合せ目を通って押出絶縁体４の内面に達
し、一部は加熱軟化状態の押出絶縁体４内に侵入する。
そして、上記加熱軟化状態の押出絶縁体４が固化する
と、この気体が押え巻層３と押出絶縁体４との界面や押
出絶縁体４内部に閉じ込められてボイドを形成する。押
え巻層３と押出絶縁体４との界面にボイドが閉じ込めら
れると、さらにこの界面の密着性および押出絶縁体４内
面の平滑性が損なわれる。このように、押え巻層と押出
絶縁体との界面や押出絶縁体の内部にボイドが形成さ
れ、またこの界面の密着性および押出絶縁体４内面の平
滑性が損なわれて欠陥が生じると、高電圧印加によっ
て、これらの欠陥部位に電界が集中し、電線に要求され
る規格値以下の課電圧で該部位から微弱な放電、即ち、
部分放電が発生し、長期間にわたって部分放電が繰り返
されると、押出絶縁体４が絶縁劣化を起こして電気特性
が悪化し、遂には絶縁破壊に到るという問題がある。[0004] However, when the extruded insulator 4 of the electric wire is formed by such a silane crosslinking method, the air or other gas contained in the refractory layer 2 thermally expands due to the heat at the time of extruding the extruded coating material. It reaches the inner surface of the extruded insulator 4 through the overlapping portion of the press tape constituting the press tape winding layer 3, and a part thereof enters the extruded insulator 4 in a heat-softened state.
When the extruded insulator 4 in the heat-softened state is solidified, this gas is confined in the interface between the presser winding layer 3 and the extruded insulator 4 or inside the extruded insulator 4 to form a void. If the void is confined at the interface between the presser winding layer 3 and the extruded insulator 4, the adhesion at this interface and the smoothness of the inner surface of the extruded insulator 4 are further impaired. As described above, voids are formed at the interface between the presser winding layer and the extruded insulator or inside the extruded insulator, and when the adhesion at this interface and the smoothness of the inner surface of the extruded insulator 4 are impaired, defects occur. By applying a high voltage, an electric field is concentrated on these defective portions, and a weak discharge from the portions at a voltage imposed below the standard value required for the wire, that is,
When a partial discharge occurs and the partial discharge is repeated for a long period of time, there is a problem that the extruded insulator 4 is deteriorated in insulation, and the electrical characteristics are deteriorated, eventually leading to dielectric breakdown.
【０００５】このような問題は、シラン架橋方式以外の
常圧架橋方式で押出絶縁体を形成する耐火電線の場合に
も当てはまる。さらに、最近は、火災時における安全性
の要求が強くなり、低電圧電線の分野でも耐火電線を採
用しようとする試みがされている。この電線の押出絶縁
体は架橋処理を行わず、導体上に高分子絶縁材料を大気
圧下で押出被覆し、冷却することにより形成される。従
って、このような低電圧電線の場合にも同様な問題があ
る。[0005] Such a problem also applies to a refractory wire in which an extruded insulator is formed by an atmospheric pressure crosslinking method other than the silane crosslinking method. Furthermore, recently, the demand for safety in the event of fire has increased, and attempts have been made to employ fire-resistant electric wires even in the field of low-voltage electric wires. The extruded insulator of the electric wire is formed by extruding a polymer insulating material onto the conductor under atmospheric pressure without cooling, and cooling. Therefore, there is a similar problem in the case of such a low-voltage electric wire.
【０００６】本発明は、このような問題を解決し、押え
巻層と押出絶縁体との界面や押出絶縁体の内部にボイド
が形成されないようにして、部分放電の発生を押さえ、
電線の電気特性を向上させるようにした耐火電線および
その製造方法を提供することを目的とする。The present invention solves such a problem and suppresses the occurrence of partial discharge by preventing voids from being formed at the interface between the presser winding layer and the extruded insulator or inside the extruded insulator.
It is an object of the present invention to provide a fire-resistant wire and a method for manufacturing the same, which improve the electrical characteristics of the wire.
【０００７】[0007]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明の耐火電線は、導体上に耐火層、押え巻層
および高分子絶縁材料からなる押出絶縁体を備え、押え
巻層が通気性を有する押えテープを巻付けて形成してな
るものである。また、本発明の耐火電線の製造方法は、
導体上に耐火層および押え巻層を形成し、この周囲に高
分子絶縁材料を押出被覆して押出絶縁体を形成する際、
押え巻層と高分子絶縁材料間の隙間を減圧しながら、押
え巻層の周囲に高分子絶縁材料を押出被覆することを特
徴とするものである。In order to achieve the above object, a refractory electric wire according to the present invention comprises a fireproof layer, a holding layer and an extruded insulator made of a polymer insulating material on a conductor. Is formed by winding a press tape having air permeability. Further, the method for producing a fire-resistant wire of the present invention,
When forming a refractory layer and a presser winding layer on a conductor and extruding a polymer insulating material around this to form an extruded insulator,
The present invention is characterized in that a polymer insulating material is extrusion-coated around the presser winding layer while reducing the pressure between the presser winding layer and the polymer insulating material.
【０００８】上記のように、押え巻層が通気性を有する
押えテープを巻付けて形成されているので、押え巻層の
周囲に高分子絶縁材料を押出被覆するときの熱で耐火層
が加熱され、層内に含まれる空気その他の気体が熱膨張
して耐火層の外表面に滲出してくるが、押え巻層が通気
性を有するため、この層内を比較的容易に通り抜けて押
え巻層の周囲に高分子絶縁材料を押出被覆する前に押え
巻層の外表面に放出される。このため、押え巻層の周囲
に高分子絶縁材料を押出被覆する際、前記気体が後方
（導体の走行方向と反対方向）に締め出され、押え巻層
と押出絶縁体との界面に閉じ込められたり、押出絶縁体
の内部に侵入することがない。従って、本発明の耐火電
線では、押え巻層と押出絶縁体との界面や押出絶縁体の
内部にボイドが形成されず、また、その界面の密着性お
よび押出絶縁体内面の平滑性を損なうこともなくなり、
これらの欠陥部分に電界が集中しないから、部分放電の
発生を押さえ、電線の電気特性を向上させることがで
き、長期間にわたり安定した絶縁特性を保持し、電線の
耐寿命性を高めることができる。As described above, since the presser winding layer is formed by wrapping a presser tape having air permeability, the refractory layer is heated by the heat generated when the polymer insulating material is extrusion-coated around the presser winding layer. Air and other gas contained in the layer are thermally expanded and exude to the outer surface of the refractory layer. However, since the holding layer has air permeability, it passes through this layer relatively easily, and the holding layer passes through the layer. Before extrusion coating of the polymeric insulating material around the layer, it is released to the outer surface of the hold down layer. For this reason, when the polymer insulating material is extrusion-coated around the presser winding layer, the gas is shut out backward (in the direction opposite to the running direction of the conductor) and is confined at the interface between the presser winding layer and the extruded insulator. , Does not enter the interior of the extruded insulator. Therefore, in the fire-resistant wire of the present invention, no void is formed at the interface between the presser winding layer and the extruded insulator or inside the extruded insulator, and the adhesion at the interface and the smoothness of the inner surface of the extruded insulator are impaired. Disappears,
Since the electric field is not concentrated on these defective portions, the occurrence of partial discharge can be suppressed, the electric characteristics of the electric wire can be improved, stable insulation characteristics can be maintained over a long period of time, and the service life of the electric wire can be increased. .
【０００９】さらに、本発明では、押え巻層の周囲に高
分子絶縁材料を押出被覆する際、押え巻層と高分子絶縁
材料間の隙間を減圧しながら押出被覆するので、押出被
覆直前に押え巻層の外表面に放出された耐火層内に含ま
れる空気その他の気体を確実に、また速やかに押出機外
へ排出させながら、押出被覆することができる。従っ
て、押出絶縁体の内面や内部にボイドが形成されず、押
え巻層と押出絶縁体間の密着性も良好で電気特性の優れ
た耐火電線を能率よく製造することができる。Further, in the present invention, when the polymer insulating material is extrusion-coated around the presser winding layer, the extrusion coating is performed while depressurizing the gap between the presser winding layer and the polymer insulating material. Extrusion coating can be performed while reliably discharging the air or other gas contained in the refractory layer discharged to the outer surface of the winding layer out of the extruder. Therefore, voids are not formed on the inner surface or inside of the extruded insulator, and a fire-resistant electric wire having good electrical properties and good adhesion between the presser winding layer and the extruded insulator can be efficiently manufactured.
【００１０】[0010]
【発明の実施の形態】次に本発明の実施の形態を図面に
基づき詳細に説明する。図１は本発明に係る耐火電線１
０Ａ、１０Ｂ、１０Cを３芯撚合わせて構成された耐火
電線１０を示す側面図である。各芯の耐火電線１０Ａ、
１０Ｂ、１０Cは同じ構成のものなので、代表として耐
火電線１０Ａについて説明する。図２は図１に示す耐火
電線１０ＡのＸ領域部分を拡大して示す部分拡大側面図
である。耐火電線１０Ａは、導体１１上に順次耐火層１
２、押え巻層１３、押出絶縁体１４を備えている。耐火
層１２は、例えば、ガラステープにマイカ箔を接着剤で
貼り合わせてなるガラスマイカテープを重ね巻きして複
数層に積層させて形成される。Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a refractory wire 1 according to the present invention.
It is a side view which shows the refractory electric wire 10 comprised by twisting three cores of 0A, 10B, and 10C. Fireproof electric wire 10A of each core,
Since 10B and 10C have the same configuration, the fireproof electric wire 10A will be described as a representative. FIG. 2 is a partially enlarged side view showing, in an enlarged manner, an X region portion of the fireproof electric wire 10A shown in FIG. The refractory electric wire 10A is formed on the conductor 11 sequentially by the refractory layer 1
2, a presser winding layer 13 and an extruded insulator 14 are provided. The refractory layer 12 is formed, for example, by laminating a glass mica tape formed by laminating a mica foil on a glass tape with an adhesive, and laminating a plurality of layers.
【００１１】押え巻層１３は、通気性を有するテープ、
例えば、短繊維間に通気穴１３ａを有する不織布テープ
１３Ａ（図５参照）又は多数の通気用の微***を設けた
ポリエステルテープ等を重ね巻きして形成される。例え
ば、通気性を有するテープとして、短繊維間に多数の通
気穴１３ａを有し、単位面積当り重量が４５ｇ／ｍ2で
約２０ｃｍ3／ｃｍ2・ｓｅｃ（フラジール法・１枚重ね
・ノズル４φで測定）の通気性を有する不織布テープ１
３Ａを重ね巻きで１層巻付けることにより形成される。
不織布テープ１３Ａの通気性は、単位面積当り重量（目
付量）によって変化し、重量が軽くなると増加し、重量
が重くなると減少する。耐火層内に含まれる空気その他
の気体の層外への抜け易さという点では、通気性の大き
い方が好ましいが、該テープの引張り強度が弱くなり押
え巻層の形成に支障を来す恐れがある。一方、引張り強
度を大きくすれば、そのような問題は解消するが、通気
性が小さくなり、上記気体の抜けが悪くなったり、強制
的に減圧して気体を抜く場合の真空度を高める必要があ
り、設備上の限界がある。このようなことを考慮し、不
織布テープ１３Ａとしては、単位面積当り重量が２５〜
５５ｇ／ｍ2で通気性が６０〜１０ｃｍ3／ｃｍ2・ｓｅ
ｃ（フラジール法・１枚重ね・ノズル４φで測定）程度
のものを用いるのが実用的である。なお、通気性を有す
るテープとして不織布テープ以外の繊維布テープ、多数
の微***を設けたポリエステルテープ等を用いた場合に
も、同様な範囲の通気性を有するものを用いることがで
きる。本発明においては、この押え巻層１３が通気性を
有するテープを巻付けて構成されるので、その周囲に高
分子絶縁材料を押出被覆するときの熱で耐火層１２内の
気体が熱膨張したとき、この気体を比較的容易に押え巻
層１３を通過して外表面に放出させることができる。The presser winding layer 13 is made of a tape having air permeability,
For example, it is formed by overlapping and winding a nonwoven fabric tape 13A having ventilation holes 13a between short fibers (see FIG. 5) or a polyester tape having a large number of ventilation fine holes. For example, as a tape having air permeability, a large number of air holes 13a are provided between short fibers, and the weight per unit area is 45 g / m 2 and is about 20 cm 3 / cm 2 · sec (Fragile method / single-layer / nozzle 4φ). Nonwoven tape 1 having air permeability
3A is formed by winding one layer by lap winding.
The air permeability of the nonwoven fabric tape 13A changes depending on the weight per unit area (weight per unit area), and increases as the weight decreases and decreases as the weight increases. From the viewpoint that air and other gases contained in the refractory layer can easily escape to the outside of the layer, it is preferable that the air permeability is large, but the tensile strength of the tape is weakened, which may hinder the formation of the holding roll layer. There is. On the other hand, if the tensile strength is increased, such a problem is solved, but the air permeability is reduced, and the escape of the gas is deteriorated, or it is necessary to increase the degree of vacuum when forcibly depressurizing and extracting the gas. Yes, there are limitations on facilities. In consideration of this, the weight per unit area of the nonwoven fabric tape 13A is 25 to
55 g / m 2 and air permeability of 60 to 10 cm 3 / cm 2 · se
It is practical to use a material having a size of about c (Fragile method, single-sheet superposition, measured with a nozzle 4φ). It should be noted that even when a fiber cloth tape other than the nonwoven fabric tape, a polyester tape provided with a large number of minute holes, or the like is used as the tape having air permeability, a tape having a similar range of air permeability can be used. In the present invention, since the press-winding layer 13 is formed by winding a tape having air permeability, the gas in the refractory layer 12 thermally expands due to heat generated when the polymer insulating material is extrusion-coated therearound. At this time, the gas can be relatively easily discharged to the outer surface through the presser winding layer 13.
【００１２】押出絶縁体１４は、例えば、ポリエチレン
１００重量部に対してビニルトリメトキシシラン等の有
機シラン化合物を１．０〜３．０重量部、有機過酸化物
を０．０５〜０．３０重量部の割合で配合した未架橋ポ
リエチレンコンパウンドを押出機（設定温度１８０〜２
２０℃、クロスヘッド部２１０℃）により、押え巻層１
３の周囲に押出被覆し、冷却後、６０〜８０℃の温水槽
内でジブチル錫ラウレート等のシラノール縮合触媒の存
在下でシラン架橋処理を施すことにより形成する。本発
明における押出絶縁体１４は、シラン架橋方式で形成す
るものばかりでなく、電子線若しくは放射線照射架橋方
式、又は超音波架橋方式で架橋処理して形成するもの、
或いは化学架橋方式であるが常圧下で架橋処理したり、
架橋処理を施さずに単に押出被覆することにより形成す
るものでもよい。なお、１５は半導電性テープを巻付け
て形成された半導電層、１６は銅テープを巻付けて形成
された遮蔽層、１７は不織布テープを巻付けて形成され
た押え巻層、１８は難燃性ポリエチレン材料からなるシ
ースである。The extruded insulator 14 is formed, for example, by adding 1.0 to 3.0 parts by weight of an organic silane compound such as vinyltrimethoxysilane and 0.05 to 0.30 parts by weight of an organic peroxide to 100 parts by weight of polyethylene. An uncrosslinked polyethylene compound compounded in a ratio of parts by weight is fed into an extruder (set temperature: 180 to 2).
20 ° C., cross head 210 ° C.)
Extrusion coating around 3 and cooling, followed by silane cross-linking treatment in the presence of a silanol condensation catalyst such as dibutyltin laurate in a hot water bath at 60 to 80 ° C. The extruded insulator 14 in the present invention is not only formed by a silane cross-linking method, but also formed by a cross-linking treatment using an electron beam or radiation irradiation cross-linking method, or an ultrasonic cross-linking method,
Or it is a chemical cross-linking method, but cross-linking treatment under normal pressure,
It may be formed simply by extrusion coating without performing a crosslinking treatment. In addition, 15 is a semiconductive layer formed by winding a semiconductive tape, 16 is a shielding layer formed by winding a copper tape, 17 is a presser winding layer formed by winding a nonwoven fabric tape, 18 is A sheath made of a flame-retardant polyethylene material.
【００１３】次に本発明の耐火電線の製造方法を説明す
る。先ず、前工程において、導体１１上に順次耐火層１
２および押え巻層１３を形成する。この形成作業は、耐
火層を形成するためのテープ巻ヘッド又はテープ巻機お
よび押え巻層を形成するためのテープ巻ヘッド又はテー
プ巻機をタンデムに配列し、耐火層１２および押え巻層
１３を連続的に形成することにより一工程で行う（図示
せず）。Next, a method for manufacturing a fire-resistant wire according to the present invention will be described. First, in the pre-process, the refractory layer 1
2 and the presser winding layer 13 are formed. In this forming operation, the tape winding head or the tape winding machine for forming the refractory layer and the tape winding head or the tape winding machine for forming the holding layer are arranged in tandem, and the refractory layer 12 and the holding layer 13 are formed. It is performed in one step by forming continuously (not shown).
【００１４】次に、このようにして導体１１上に耐火層
１２および押え巻層１３を形成してなる電線コア１９
を、図３に示すように、押出成形装置２０に供給して、
電線コア１９の周囲に高分子絶縁材料を押出被覆する。
押出成形装置２０は、押出機２１とその先端に設けられ
たクロスヘッド２２により構成される。クロスヘッド２
２は、図４に詳細に示すように、ヘッド本体２３と、ヘ
ッド本体２３内に設けられたダイス２４と、ニップル２
５と、真空吸引手段２６により構成される。真空吸引手
段２６は、内部を通す電線コア１９の供給口にパッキン
２７Ａと、側部に真空吸引口２７Ｂを有し、クロスヘッ
ド２２の後部に取付けられた真空吸引管体２７と、真空
吸引管体２７内を真空吸引する真空ポンプ２８（図３参
照）と、真空吸引口２７Ｂと真空ポンプ２８とを連結す
る配管２９により構成される。なお、図３において、３
０は真空ゲージである。そして、前記電線コア１９を図
４、５に示すように、押出成形装置２０のクロスヘッド
２２の真空吸引管体２７、ニップル２５およびダイス２
４の内部に通してクロスヘッド外へ引き出して走行させ
ると共に、押出機２１で押出成形可能に加熱された高分
子絶縁材料、例えば、有機シラン化合物を配合した未架
橋ポリエチレン材料Ａをクロスヘッド２２内に供給し、
ダイス２４、ニップル２５間の押出流路を通して電線コ
ア１９の周囲に押出被覆して押出絶縁体１４を形成す
る。Next, an electric wire core 19 having the refractory layer 12 and the presser winding layer 13 formed on the conductor 11 in this manner.
Is supplied to the extrusion molding device 20 as shown in FIG.
A polymer insulating material is extrusion-coated around the wire core 19.
The extruder 20 includes an extruder 21 and a crosshead 22 provided at a tip of the extruder 21. Crosshead 2
2, a head body 23, a die 24 provided in the head body 23, and a nipple 2 as shown in detail in FIG.
5 and vacuum suction means 26. The vacuum suction means 26 has a packing 27A at a supply port of the electric wire core 19 passing therethrough, a vacuum suction port 27B at a side portion, and a vacuum suction pipe 27 attached to a rear portion of the crosshead 22; It comprises a vacuum pump 28 (see FIG. 3) for vacuum-sucking the inside of the body 27 and a pipe 29 connecting the vacuum suction port 27B and the vacuum pump 28. In FIG. 3, 3
0 is a vacuum gauge. Then, as shown in FIGS. 4 and 5, the wire core 19 is connected to the vacuum suction tube 27, the nipple 25 and the die 2 of the crosshead 22 of the extrusion molding apparatus 20.
4, a polymer insulating material, such as an uncrosslinked polyethylene material A containing an organic silane compound, heated to be extrudable by the extruder 21 while being drawn out of the crosshead and run. Supply to
The extruded insulator 14 is formed by extrusion coating around the wire core 19 through an extrusion flow path between the die 24 and the nipple 25.
【００１５】本発明では、この作業を行うと同時に、図
５に示すように、真空吸引手段２６の真空ポンプ２８
（図３参照）を駆動して真空吸引管体２７内を絶対圧力
５００ｍｍＨｇ以下に真空吸引することにより、電線コ
ア１９の押え巻層１３と押出成形可能に加熱軟化された
未架橋ポリエチレン材料Ａ間の先細り筒状の隙間３１を
減圧しながら、押え巻層１３の周囲に未架橋ポリエチレ
ン材料Ａを押出被覆する。この隙間３１を減圧すること
により、この隙間３１と押え巻層１３との間に圧力差が
生じ、未架橋ポリエチレン材料Ａの押出時の熱で、熱膨
張した耐火層１２内に含まれる空気その他の気体を、図
５に示すように、押え巻層１３を構成する通気性を有す
るテープ、例えば不織布テープ１３の通気穴１３ａを通
して吸出して速やかに押え巻層１３の外表面に放出さ
せ、さらに真空吸引管体２７を通して押出成形装置２０
の外方へ排出させる。このような気体の処理を行うの
で、前記材料の押出被覆の際、押え巻層１３と押出絶縁
体１４との界面や押出絶縁体１４内にボイドが形成され
る不具合を確実に防止することができる。In the present invention, at the same time as performing this operation, as shown in FIG.
By driving (see FIG. 3) and vacuum-suctioning the inside of the vacuum suction tube 27 to an absolute pressure of 500 mmHg or less, the space between the press-wrapping layer 13 of the wire core 19 and the extrudable heat-softened uncrosslinked polyethylene material A is formed. While the pressure in the tapered cylindrical gap 31 is reduced, the periphery of the presser winding layer 13 is extrusion-coated with the uncrosslinked polyethylene material A. By reducing the pressure in the gap 31, a pressure difference is generated between the gap 31 and the presser winding layer 13, and the air and the like contained in the refractory layer 12 thermally expanded by the heat generated during the extrusion of the uncrosslinked polyethylene material A. As shown in FIG. 5, this gas is sucked out through a ventilation hole 13a of a permeable tape, for example, a non-woven fabric tape 13 that forms the press-winding layer 13, and is quickly released to the outer surface of the press-winding layer 13. Extruder 20 through suction tube 27
To the outside. Since such a gas treatment is performed, it is possible to reliably prevent a problem that voids are formed in the interface between the presser winding layer 13 and the extruded insulator 14 and in the extruded insulator 14 during the extrusion coating of the material. it can.
【００１６】このようにして、押え巻層１３の周囲に未
架橋ポリエチレン材料Ａを押出被覆し、その後に、押出
成形装置２０の後段に配置された冷却水槽（図示せず）
に通して水冷し、ドラム等に巻き取る。この後は、これ
をシラン架橋用の温水槽（図示せず）に入れて、シラン
架橋処理を施して押出絶縁体１４を形成する。押出絶縁
体１４を形成した後は、公知の方法で、この周囲に順次
半導電層１５、遮蔽層１６、押え巻層１７およびシース
１８を形成し、耐火電線１０Ａを製造する。他の耐火電
線１０Ｂ、１０Ｃも同様な方法で製造し、３芯撚合せて
耐火電線１０を製造する。In this manner, the uncrosslinked polyethylene material A is extrusion-coated around the presser winding layer 13, and thereafter, a cooling water tank (not shown) arranged at the subsequent stage of the extrusion molding device 20.
And water-cooled and wound up on a drum or the like. After that, the extruded insulator 14 is formed by placing it in a hot water tank (not shown) for silane crosslinking and performing silane crosslinking treatment. After the extruded insulator 14 is formed, a semiconductive layer 15, a shielding layer 16, a presser winding layer 17 and a sheath 18 are sequentially formed around the extruded insulator 14 to manufacture a fire-resistant electric wire 10A. The other refractory wires 10B and 10C are manufactured in the same manner, and the three cores are twisted to manufacture the refractory wire 10.
【００１７】[0017]
【実施例】本発明の具体的な実施例について説明する。
先ず、導体断面積が３８ｍｍ2の銅撚線の導体１１上
に、０．１８ｍｍ厚さのガラスマイカテープを１／２重
ね巻きで６層に巻付けることにより、耐火層１２を形成
し、その上に単位面積当り重量が４５ｇ／ｍ2で通気性
が約２０ｃｍ3／ｃｍ2・ｓｅｃ（フラジール法）の不織
布テープを１／５重ね巻きで１層巻付けることにより押
え巻層１３を形成し、電線コア１９を得た。次に、この
電線コア１９を押出成形装置２０のクロスヘッド２２内
に走行させると共に、クロスヘッド２２内を絶対圧力２
００ｍｍＨｇに減圧しながら、電線コア１９の周囲に、
有機シラン化合物を配合させた未架橋ポリエチレン材料
Ａを４ｍｍ厚さに押出被覆し、冷却水槽で冷却し、ドラ
ムに巻き取った。その後、この電線コア１９をドラム
毎、大気圧下で７０℃の温水中に浸し、シラン架橋処理
を施し押出絶縁体１４を形成した。EXAMPLES Specific examples of the present invention will be described.
First, a 0.18 mm-thick glass mica tape is wound on a copper stranded conductor 11 having a conductor cross-sectional area of 38 mm 2 in six layers by 重 ね lap winding to form a refractory layer 12. A non-woven tape having a weight per unit area of 45 g / m 2 and air permeability of about 20 cm 3 / cm 2 · sec (Fragile method) is wound on one layer in a 1/5 lap winding to form a holding roll layer 13. Thus, an electric wire core 19 was obtained. Next, the electric wire core 19 is caused to travel into the crosshead 22 of the extrusion molding device 20 and the inside of the crosshead 22 is subjected to an absolute pressure of 2.
While reducing the pressure to 00 mmHg, around the wire core 19,
An uncrosslinked polyethylene material A containing an organosilane compound was extrusion-coated to a thickness of 4 mm, cooled in a cooling water bath, and wound around a drum. Thereafter, the wire core 19 was immersed in warm water at 70 ° C. under atmospheric pressure for each drum, and subjected to silane crosslinking treatment to form an extruded insulator 14.
【００１８】この後、この押出絶縁体１４の上に、半導
電テープを１／６重ね巻きで１層巻付けることにより、
半導電層１５を形成し、その上に銅テープを１／６重ね
巻きで１層巻付けることにより遮蔽層１６を形成し、そ
の上に不織布テープを１／５重ね巻きで巻付けることに
より押え巻層１７を形成し、さらにその上にノンハロゲ
ン難燃材を配合したポリエチレン材料を２．３ｍｍの厚
さに押出被覆してシース１８を形成し、６．６ｋＶ用の
高電圧耐火電線を試作した。Thereafter, a semiconductive tape is wound on the extruded insulator 14 by one-sixteenth lap winding.
A semiconductive layer 15 is formed, a copper tape is wrapped thereon by 1/6 lap winding to form a shielding layer 16, and a nonwoven fabric tape is wrapped thereon by １ ／ lap winding to hold down. A winding layer 17 was formed, and a polyethylene material containing a halogen-free flame retardant was further formed thereon by extrusion coating to a thickness of 2.3 mm to form a sheath 18, and a high-voltage fire-resistant electric wire for 6.6 kV was prototyped. .
【００１９】またこの耐火電線と電気性能を比較するた
め、従来の耐火電線、即ち、押え巻層として、通気用の
通気穴が設けられていない厚さ３５μｍのポリエステル
テープを１／２重ね巻きで１層巻付けて形成したものを
用い、他の構造は試作電線と同材質、同サイズの耐火電
線（比較例、内部にボイド有り）を製作した。これらの
耐火電線について電気特性を比較した結果を表１に示
す。In order to compare the electric performance with this fire-resistant electric wire, a conventional fire-resistant electric wire, that is, a 35 μm-thick polyester tape having no ventilation hole for ventilation as a press-winding layer was formed by 重 ね lap winding. A fire-resistant electric wire having the same material and the same size as the prototype electric wire (comparative example, with a void inside) was manufactured using the one formed by winding one layer. Table 1 shows the results of comparing the electrical characteristics of these refractory wires.
【００２０】[0020]
【表１】 [Table 1]
【００２１】上記表から分かるように、本発明のシラン
架橋耐火電線（内部にボイドなし）は、部分放電発生電
圧（平均値）が１０．５ｋＶで、規格値の６．９ｋＶよ
り高くなり、試験に合格した。このため、部分放電特性
が向上し、長期絶縁特性が確保される。これに対して、
通気性のないポリエステルテープを押え巻層とする耐火
電線（比較例、内部にボイド有り）は、部分放電発生電
圧（平均値）が５．９ｋＶで、規格値より低くなり不合
格となった。このため、部分放電特性が悪く、長期絶縁
特性を確保することが難しい。As can be seen from the above table, the silane-crosslinked refractory wire of the present invention (without voids inside) had a partial discharge generation voltage (average value) of 10.5 kV, which was higher than the standard value of 6.9 kV. Passed. Therefore, partial discharge characteristics are improved, and long-term insulation characteristics are secured. On the contrary,
The fire-resistant electric wire (comparative example, having voids inside) using a non-breathable polyester tape as the holding layer had a partial discharge generation voltage (average value) of 5.9 kV, which was lower than the standard value, and was rejected. Therefore, the partial discharge characteristics are poor, and it is difficult to secure long-term insulation characteristics.
【００２２】[0022]
【発明の効果】上記したように、本発明の耐火電線は、
導体上に耐火層、押え巻層および高分子絶縁材料からな
る押出絶縁体を備え、押え巻層が通気性を有する押えテ
ープを巻付けて形成してなるから、押え巻層の周囲に高
分子絶縁材料を押出被覆するときの熱で耐火層が加熱さ
れ、層内に含まれる空気その他の気体が熱膨張すると、
押え巻層内を容易に通り抜け、押え巻層の周囲に高分子
絶縁材料を押出被覆する前に押え巻層の外表面に放出さ
れるから、該気体が押え巻層と押出絶縁体との界面に閉
じ込められたり、押出絶縁体の内部に侵入することがな
い。従って、押え巻層と押出絶縁体との界面や押出絶縁
体の内部にボイドが形成されず、また、その界面の密着
性および押出絶縁体内面の平滑性も損なわれず、これら
の欠陥部分に電界が集中しないから、部分放電の発生を
押さえ、電線の電気特性を向上させることができ、長期
間にわたり安定した絶縁特性を保持し、電線の耐寿命性
を高めることができる。As described above, the fire-resistant electric wire of the present invention comprises:
A fireproof layer, a presser winding layer, and an extruded insulator made of a polymer insulating material are provided on the conductor, and the presser winding layer is formed by winding a presser tape having air permeability. When the refractory layer is heated by the heat of extrusion coating the insulating material, and the air and other gases contained in the layer thermally expand,
Since the gas easily passes through the inside of the presser winding layer and is released to the outer surface of the presser winding layer before extrusion-coating the insulating polymer layer around the presser winding layer, the gas is released from the interface between the presser winding layer and the extruded insulator. It does not get trapped in or extrude inside the extruded insulator. Therefore, voids are not formed at the interface between the presser winding layer and the extruded insulator or inside the extruded insulator, and the adhesion at the interface and the smoothness of the inner surface of the extruded insulator are not impaired. Is not concentrated, the occurrence of partial discharge can be suppressed, the electric characteristics of the electric wire can be improved, stable insulation characteristics can be maintained for a long period, and the life resistance of the electric wire can be increased.
【００２３】また、本発明の耐火電線の製造方法は、導
体上に耐火層および押え巻層を形成し、この周囲に高分
子絶縁材料を押出被覆して押出絶縁体を形成する際、押
え巻層と高分子絶縁材料間の隙間を減圧しながら、押え
巻層の周囲に高分子絶縁材料を押出被覆するので、押出
被覆前に耐火層内に含まれる空気その他の気体を確実
に、また速やかにその隙間から排除することができ、押
出絶縁体の内面や内部にボイドが形成されず、また押え
巻層と押出絶縁体間の密着性が良好で界面に不整のない
電気特性の優れた耐火電線を能率よく製造することがで
きる。Further, the method for producing a fire-resistant wire according to the present invention is characterized in that a fire-resistant layer and a presser-winding layer are formed on a conductor, and a polymer insulating material is extrusion-coated around the layer to form an extruded insulator. Extrusion coating of the polymer insulating material around the presser winding layer while reducing the pressure between the layer and the polymer insulating material ensures that air and other gases contained in the refractory layer are promptly and promptly before extrusion coating. The voids are not formed on the inner surface or inside of the extruded insulator, and the adhesion between the presser winding layer and the extruded insulator is good and the interface has no irregularity. Electric wires can be manufactured efficiently.
【図１】本発明の耐火電線（３芯構造）を示す側面図で
ある。FIG. 1 is a side view showing a fireproof electric wire (three-core structure) of the present invention.
【図２】図１に示す耐火電線のＸ領域部分を拡大して示
す部分拡大側面図である。FIG. 2 is a partially enlarged side view showing an X region of the refractory wire shown in FIG. 1 in an enlarged manner.
【図３】本発明の耐火電線の押出絶縁体を形成する押出
成形装置を示す概要図である。FIG. 3 is a schematic diagram showing an extrusion molding apparatus for forming an extruded insulator of a fire-resistant wire of the present invention.
【図４】押出成形装置のクロスヘッドを示す断面図であ
る。FIG. 4 is a sectional view showing a crosshead of the extrusion molding apparatus.
【図５】押出成形装置を用いて押え巻層の周囲に押出絶
縁体を押出被覆する状態を示す断面図である。FIG. 5 is a cross-sectional view showing a state where an extruded insulator is extrusion-coated around a presser winding layer using an extrusion molding apparatus.
【図６】従来の耐火電線を示す側面図である。FIG. 6 is a side view showing a conventional fireproof electric wire.
１０ 耐火電線（３芯構造） １０Ａ 耐火電線 １０Ｂ 耐火電線 １０Ｃ 耐火電線 １１ 導体 １２ 耐火層 １３ 押え巻層 １３Ａ 不織布テープ １３ａ 通気穴 １４ 押出絶縁体 １５ 半導電層 １６ 遮蔽層 １７ 押え巻層 １８ シース １９ 電線コア ２０ 押出成形装置 ２１ 押出機 ２２ クロスヘッド ２３ ヘッド本体 ２４ ダイス ２５ ニップル ２６ 真空吸引手段 ２７Ａ パッキン ２７Ｂ 真空吸引口 ２８ 真空ポンプ ２９ 配管 ３０ 真空ゲージ ３１ 隙間 Ａ 未架橋ポリエチレン材料 DESCRIPTION OF SYMBOLS 10 Fire-resistant electric wire (3-core structure) 10A Fire-resistant electric wire 10B Fire-resistant electric wire 10C Fire-resistant electric wire 11 Conductor 12 Fireproof layer 13 Holding winding layer 13A Nonwoven fabric tape 13a Vent hole 14 Extrusion insulator 15 Semiconductive layer 16 Shielding layer 17 Holding winding layer 18 Sheath 19 Electric wire core 20 Extruder 21 Extruder 22 Crosshead 23 Head body 24 Dice 25 Nipple 26 Vacuum suction means 27A Packing 27B Vacuum suction port 28 Vacuum pump 29 Piping 30 Vacuum gauge 31 Gap A Non-crosslinked polyethylene material
Claims (2)
絶縁材料からなる押出絶縁体を備え、押え巻層が通気性
を有する押えテープを巻付けて形成してなることを特徴
とする耐火電線。An extruded insulator made of a refractory layer, a presser winding layer and a polymer insulating material is provided on a conductor, and the presser winding layer is formed by winding a presser tape having air permeability. Fire resistant wires.
し、この周囲に高分子絶縁材料を押出被覆して押出絶縁
体を形成する際、押え巻層と高分子絶縁材料間の隙間を
減圧しながら、押え巻層の周囲に高分子絶縁材料を押出
被覆することを特徴とする耐火電線の製造方法。2. When a refractory layer and a holding layer are formed on a conductor and a polymer insulating material is extrusion-coated therearound to form an extruded insulator, a gap between the holding layer and the polymer insulating material is formed. A method for manufacturing a refractory wire, comprising extruding a polymer insulating material around a presser winding layer while reducing pressure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24670299A JP3813389B2 (en) | 1999-08-31 | 1999-08-31 | Refractory wire and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24670299A JP3813389B2 (en) | 1999-08-31 | 1999-08-31 | Refractory wire and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001076549A true JP2001076549A (en) | 2001-03-23 |
| JP3813389B2 JP3813389B2 (en) | 2006-08-23 |
Family
ID=17152374
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24670299A Expired - Lifetime JP3813389B2 (en) | 1999-08-31 | 1999-08-31 | Refractory wire and manufacturing method thereof |
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| Country | Link |
|---|---|
| JP (1) | JP3813389B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100952160B1 (en) | 2008-01-30 | 2010-04-09 | 김백규 | A production way of silicon flame resisting fireproof cable |
| JP2014159113A (en) * | 2013-02-19 | 2014-09-04 | Sumitomo Wiring Syst Ltd | Method for manufacturing a water-crosslinked long object |
| JP2015149145A (en) * | 2014-02-05 | 2015-08-20 | 東日本旅客鉄道株式会社 | power distribution cable and signal system |
-
1999
- 1999-08-31 JP JP24670299A patent/JP3813389B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100952160B1 (en) | 2008-01-30 | 2010-04-09 | 김백규 | A production way of silicon flame resisting fireproof cable |
| JP2014159113A (en) * | 2013-02-19 | 2014-09-04 | Sumitomo Wiring Syst Ltd | Method for manufacturing a water-crosslinked long object |
| JP2015149145A (en) * | 2014-02-05 | 2015-08-20 | 東日本旅客鉄道株式会社 | power distribution cable and signal system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3813389B2 (en) | 2006-08-23 |
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