JPH08182143A - Manufacture of reinforced insulator used for connecting section of power cable - Google Patents

Abstract

PURPOSE: To reduce the electric field impressed in the direction parallel to the boundaries between a reinforced insulator and two rods so that the insulator can be welded to the rods under a wider range of welding conditions by burying high-voltage shield electrodes between the recessed and projecting sections of the two rods and machining the rods after the rods are integrated into one body by welding. CONSTITUTION: After putting burying sections and high-voltage shield electrodes 5 between the projecting and recessed sections of two rods, the rods are integrated into one body by putting the projecting sections in the recessed sections and welding the rods to each other. Then a reinforced insulator 10 is manufactured by machining the integrated rod. This insulator 10 is heated and pressurized after the conductors 12 of power cables 11 are connected. When the insulator 10 is manufactured in such a way, the occurrence of dielectric breakdown which is caused by the boundary is eliminated, because the welded boundary of the two rods forms an angle of 15 deg. to 45 deg. against the direction of electric field and the electric field impressed upon the boundary becomes 26-70% less than the case where the electric field is impressed in the vertical direction. In addition, the range of the welding conditions of the rods can be widened.

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、ケーブル等の電力ケ
ーブル接続部に使用する補強絶縁体の製造方法に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a reinforced insulator used in a power cable connecting portion such as a cable.

【０００２】[0002]

【従来の技術】電力ケーブルの接続部の接続手段の中
で、前処理した接続用ケーブルを予め作成された補強絶
縁体に挿入，熱処理し、溶融着することで接続する接続
方法（ＢＭＪ）において、補強絶縁体の出来具合は、ケ
ーブル接続部の性能に大きな影響を及ぼす。従来は、補
強絶縁体の最終形状に設計された金型内に押出機より、
溶融した樹脂を注入し、作成されていた。2. Description of the Related Art In a connection method (BMJ) in which a pre-processed connecting cable is inserted into a reinforced insulating body prepared in advance among the connecting means of a connecting portion of a power cable, heat-treated, and melted to be connected. The performance of the reinforced insulator greatly affects the performance of the cable connection part. Conventionally, from the extruder in the mold designed to the final shape of the reinforced insulator,
It was made by injecting molten resin.

【０００３】[0003]

【発明が解決しようとする課題】従来の成形方法では、
金型内で溶融した樹脂を冷却固化させるため、樹脂の引
けなど溶融時と固化時の寸法の変化を予め考慮した金型
設計が必要になるが、冷却方法によっても最終寸法が異
なるため、特に超高電圧電力ケーブルの接続部に使用す
る補強絶縁体については、設計が難しい。また、補強絶
縁体は、ケーブル挿入部が設けられるため、金型には中
子が必要となる。特に超高電圧電力ケーブルの場合、補
強絶縁体の絶縁厚さが厚くなり、固化による収縮力によ
って、中子には大きな締め付け力が加わるためこれを抜
くために特殊な工夫、あるいは表面の処理などが必要と
なる。そこで、ロッド状に押出し成形されたものを切削
加工することにより、専用の金型を必要とせず、容易に
様々な寸法の補強絶縁体を製造することを試みたが、こ
の方法では、高圧シールド電極を埋め込むために、最終
的な補強絶縁体を長手方向に垂直に２分割している。分
割部分はシールド電極埋め込み後融着されるが、使用時
の電界がこの融着界面と水平方向にかかるため、融着条
件を誤ると界面から電気絶縁破壊を生じる恐れがある。SUMMARY OF THE INVENTION In the conventional molding method,
In order to cool and solidify the resin melted in the mold, it is necessary to design the mold in consideration of the change in dimensions during melting and solidification, such as shrinkage of the resin, but the final dimensions differ depending on the cooling method. It is difficult to design the reinforced insulator used for the connection part of the ultra high voltage power cable. Further, since the reinforcing insulator is provided with the cable insertion portion, the mold requires a core. Especially in the case of ultra-high-voltage power cables, the insulation thickness of the reinforcing insulator becomes thicker, and the shrinking force due to solidification applies a large tightening force to the core, so special measures are taken to remove this, or surface treatment, etc. Is required. Therefore, we tried to easily manufacture reinforced insulators of various sizes by cutting the rod-shaped extruded product without the need for a dedicated mold. In order to embed the electrodes, the final reinforced insulator is divided into two perpendicular to the longitudinal direction. The divided portions are fused after embedding the shield electrode, but the electric field during use is applied to the fusion interface in the horizontal direction, and therefore, if the fusion conditions are incorrect, there is a risk of electrical breakdown from the interface.

【０００４】そこで、この発明は、２本のロッドの融着
界面を凸凹なかみ合う錘状に切削することによって、使
用時の界面と水平な方向にかかる電界を小さくすること
ができ、より広範囲な融着条件での融着が可能となり、
補強絶縁体の製造がより容易になるようにした補強絶縁
体の製造方法を提供することを目的とする。Therefore, according to the present invention, an electric field applied in a horizontal direction to the interface during use can be reduced by cutting the fusion-bonded interface of two rods into a conical shape that engages with each other in an uneven shape, and thus a wider range can be obtained. Fusing under fusion conditions is possible,
It is an object of the present invention to provide a method for manufacturing a reinforced insulator, which makes it easier to manufacture the reinforced insulator.

【０００５】[0005]

【課題を解決するための手段】上述の目的を達成するた
め、この発明は、樹脂材料を押出し成形して中実のロッ
ドを成形し、このロッドを融点以下の温度で熱処理して
残留歪みを開放し、熱処理後の２本のロッドの１本の一
端を凸錐状の凸部に切削形成するとともに他の１本の一
端を凹錘状の凹部に切削形成し、これら凹凸部に高圧シ
ールド電極を埋め込むための埋め込み用部を切削形成
し、この埋め込み用部に高圧シールド電極を埋め込むと
ともに２本のロッドを融着し、融着され一体化されたロ
ッドを切削して補強絶縁体を形成するものである。In order to achieve the above-mentioned object, according to the present invention, a resin material is extruded to form a solid rod, and the rod is heat-treated at a temperature below its melting point to remove residual strain. After opening and heat-treating, one end of the two rods is cut and formed into a convex cone-shaped convex portion, and the other one end is cut and formed into a concave cone-shaped concave portion. An embedding portion for embedding the electrode is cut and formed, the high-voltage shield electrode is embedded in the embedding portion, two rods are fused, and the fused and integrated rod is cut to form a reinforcing insulator. To do.

【０００６】[0006]

【作用】２本のロッドの凹部と凸部との間に高圧シール
ド電極を埋め込み、その後融着してロッドを一体化し、
補強絶縁体の形状に切削加工するので、専用の金型を必
要とせず、容易に様々な寸法に形成でき、接続部の性能
も向上し、特に２本のロッドの融着界面が電線の長手方
向に垂直ではなく傾斜（錘状の凹凸）しているので、使
用時の界面と水平な方向にかかる電界を小さくすること
ができる。[Operation] A high-voltage shield electrode is embedded between the concave and convex portions of two rods and then fused to integrate the rods,
Since it is machined into the shape of a reinforced insulator, it does not require a dedicated mold and can be easily formed into various dimensions, and the performance of the connection part is also improved. Especially, the fusion interface of two rods is the length of the wire. Since it is not perpendicular to the direction but is inclined (concave and convex like a cone), it is possible to reduce the electric field applied to the interface and the horizontal direction during use.

【０００７】[0007]

【実施例】以下にこの発明の好適な実施例を図面に基づ
き説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

【０００８】最初に、樹脂材料、例えばポリエチレンを
押出機から押出して図１に示す中実のロッド１を成形す
る。このロッド１は成形される補強絶縁体１０（後述す
る）の外径より外径が大きい。このロッド１を成形した
後に補強絶縁体１０の融点以下の温度、望ましくは融点
に対し−５〜−１０℃の範囲で熱処理を行い、ロッド１
の残留歪みを開放する。熱処理時間は、ロッド１のすべ
ての部分が上記温度範囲になってから１時間以上２４時
間以内が望ましい。このようなロッド１を２本用意し、
その内の１本について長手方向についてケーブル長手方
向に対し一定の角度を有した凸錘状に切削形成して凸部
２を形成する。もう１本は図２に示すロッド１とかみ合
うように一定の角度（１８０°−凸部２の角度）を有し
た凹錘状の凹部３に切削形成する（図３参照）。切削の
角度は特に規定されるものではないが、角度が小さすぎ
ると次の工程が難しくなり、角度が９０°に近くなると
界面が電界方向と水平に近づいていくため効果が薄れ
る。したがって、望ましくは１５〜４５°の角度に切削
形成する。First, a resin material such as polyethylene is extruded from an extruder to form a solid rod 1 shown in FIG. The rod 1 has an outer diameter larger than the outer diameter of a reinforcing insulator 10 (described later) to be molded. After molding this rod 1, heat treatment is performed at a temperature equal to or lower than the melting point of the reinforced insulator 10, preferably in the range of -5 to -10 ° C with respect to the melting point.
Release the residual strain of. The heat treatment time is preferably 1 hour or more and 24 hours or less after all the parts of the rod 1 are in the above temperature range. Prepare two such rods 1,
One of them is cut into a convex cone shape having a constant angle in the longitudinal direction with respect to the cable longitudinal direction to form the convex portion 2. The other is cut and formed in a concave cone-shaped concave portion 3 having a constant angle (180 ° −angle of the convex portion 2) so as to be engaged with the rod 1 shown in FIG. 2 (see FIG. 3). The cutting angle is not particularly specified, but if the angle is too small, the next step becomes difficult, and if the angle approaches 90 °, the interface approaches the horizontal direction of the electric field, and the effect diminishes. Therefore, it is desirable to cut and form at an angle of 15 to 45 °.

【０００９】凸部２や凹部３を形成した２本のロッド１
のそれぞれ凸部２や凹部３が形成された側に、図４及び
図５に示すように、高圧シールド電極５を埋め込むため
の埋め込み用部４を切削形成する。また、凸部２を高圧
シールド電極５の形状に合わせて切削加工してある。Two rods 1 having a convex portion 2 and a concave portion 3 formed therein
As shown in FIGS. 4 and 5, the embedding portion 4 for embedding the high-voltage shield electrode 5 is cut and formed on the side where the convex portion 2 and the concave portion 3 are formed. The convex portion 2 is cut according to the shape of the high-voltage shield electrode 5.

【００１０】２本のロッド１に形成された埋め込み用部
４に高圧シールド電極５を埋め込み凹部３に凸部２をか
み合せ、２本のロッド１を融着する（図６参照）。高圧
シールド電極５を埋め込み融着して一体化されたロッド
１は図７に示すように切削加工されて補強絶縁体１０と
する。The high voltage shield electrode 5 is embedded in the embedding portion 4 formed on the two rods 1, and the convex portion 2 is engaged with the concave portion 3 to fuse the two rods 1 (see FIG. 6). The rod 1 in which the high-voltage shield electrode 5 is embedded and fused and integrated is cut and processed into a reinforcing insulator 10 as shown in FIG.

【００１１】このようにして製造された補強絶縁体１０
は、図８に示すように、電力ケーブル１１の導体１２を
接続した後に加熱，加圧される。Reinforced insulator 10 manufactured in this way
Is heated and pressurized after connecting the conductor 12 of the power cable 11 as shown in FIG.

【００１２】このようにして製造された補強絶縁体１０
は２本のロッド１を融着した界面が電界方向と１５〜４
５°の角度を有することとなり、電界も垂直の場合の２
６〜７０％になり、この界面が原因となる電気絶縁破壊
は生じなくなる。Reinforced insulator 10 manufactured in this way
Is 15 to 4 when the interface where the two rods 1 are fused is in the direction of the electric field.
It has an angle of 5 ° and the electric field is 2
It becomes 6 to 70%, and electric insulation breakdown caused by this interface does not occur.

【００１３】なお、高圧シールド電極５を埋め込んで２
本のロッド１を融着する工程はロッド１を補強絶縁体１
０の形状に成形した後に行ってもよく、この場合は２本
のロッド１を組合せた時に補強絶縁体１０の最終形状と
なるようにそれぞれ切削形成する。The high-voltage shield electrode 5 is embedded and
In the step of fusing the rod 1 of the book, the rod 1 is reinforced with the insulator 1.
It may be carried out after forming into the shape of 0, and in this case, it is cut and formed so that the final shape of the reinforcing insulator 10 is obtained when the two rods 1 are combined.

【００１４】以下に実施例と比較例とを示す。この実施
例では、１０種類の補強絶縁体１０を作成し、１〜１０
と番号が大きくなるにつれて、高圧シールド電極５を埋
め込んだ時の融着温度を徐々に長くしていったものを示
す。なお錘状に切削する時の角度は１５°，３０°，４
５°とした。また、比較例についても実施例と同様の工
程に沿って同様の１０種類の補強絶縁体を作成したが、
錘状に切削する時の角度は６０°とした。またこの融着
面を９０°としたものも比較例として１０種類用意し
た。これらの実施例及び比較例について電気性能試験を
実施した結果は次の表の通りである。Examples and comparative examples are shown below. In this embodiment, 10 kinds of reinforcing insulators 10 are prepared, and 1 to 10 are prepared.
Indicates that the fusing temperature when the high-voltage shield electrode 5 is embedded is gradually increased as the number increases. In addition, the angles when cutting in a cone shape are 15 °, 30 °, 4
It was set to 5 °. Further, for the comparative example, the same 10 kinds of reinforced insulators were prepared along the same steps as those of the example.
The angle when cutting into a conical shape was 60 °. In addition, 10 kinds of those having a fusion-bonding surface of 90 ° were prepared as comparative examples. The following table shows the results of the electrical performance tests performed on these examples and comparative examples.

【００１５】[0015]

【表１】 [Table 1]

【００１６】上記表中の電気性能試験は、２４時間８０
℃の水に浸した後８時間、２４時間、３２時間の課電冷
却を行った（１５ＫＶ）ものである。The electrical performance test in the above table is 80 hours for 24 hours.
After immersion in water at ℃ for 8 hours, 24 hours, and 32 hours, voltage cooling was performed (15 KV).

【００１７】[0017]

【発明の効果】以上説明したように、この発明によれ
ば、２本のロッドの融着界面を凸凹なかみ合う錘状に切
削することによって、使用時の界面と水平な方向にかか
る電界を小さくすることができ、より広範囲な融着条件
での融着が可能となり、補強絶縁体の製造がより容易に
なる。また、補強絶縁体の形状に切削加工するので、専
用の金型を必要とせず、容易に様々な寸法に形成でき、
接続部の性能も向上する。As described above, according to the present invention, the electric field applied in the horizontal direction to the interface during use is reduced by cutting the fused interface of the two rods into the shape of a cone that meshes with the uneven surface. It is possible to perform fusion under a wider range of fusion conditions, and it becomes easier to manufacture the reinforcing insulator. Also, since it is cut into the shape of the reinforced insulator, it does not require a dedicated mold and can be easily formed into various dimensions.
The performance of the connection is also improved.

【図面の簡単な説明】[Brief description of drawings]

【図１】押出し成形されたロッドの斜視図。FIG. 1 is a perspective view of an extruded rod.

【図２】一方のロッドに凸部を形成した状態の斜視図。FIG. 2 is a perspective view showing a state where a convex portion is formed on one rod.

【図３】他方のロッドに凹部を形成した状態の斜視図。FIG. 3 is a perspective view showing a state in which a recess is formed on the other rod.

【図４】凸部が形成されたロッドに埋め込み用部を形成
した状態の斜視図。FIG. 4 is a perspective view showing a state where an embedding portion is formed on a rod on which a convex portion is formed.

【図５】凹部が形成されたロッドに埋め込み用部を形成
した状態の斜視図。FIG. 5 is a perspective view showing a state in which an embedding portion is formed on a rod having a recess.

【図６】高圧シールド電極を埋め込む際の斜視図。FIG. 6 is a perspective view when a high-voltage shield electrode is embedded.

【図７】２本のロッドを融着し切削加工して補強絶縁体
を形成した斜視図。FIG. 7 is a perspective view in which two rods are fused and cut to form a reinforcing insulator.

【図８】補強絶縁体を用いて電力ケーブル接続部を形成
した断面図。FIG. 8 is a cross-sectional view in which a power cable connecting portion is formed using a reinforced insulator.

【符号の説明】[Explanation of symbols]

１ ロッド ２ 凸部 ３ 凹部 ４ 埋め込み用部 ５ 高圧シールド電極 １０ 補強絶縁体 1 rod 2 convex part 3 concave part 4 embedding part 5 high-voltage shield electrode 10 reinforced insulator

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 樹脂材料を押出し成形して中実のロッド
を成形し、 このロッドを融点以下の温度で熱処理して残留歪みを開
放し、 熱処理後の２本のロッドの１本の一端を凸錐状の凸部に
切削形成するとともに他の１本の一端を凹錘状の凹部に
切削形成し、 これら凹凸部に高圧シールド電極を埋め込むための埋め
込み用部を切削形成し、 この埋め込み用部に高圧シールド電極を埋め込むととも
に２本のロッドを融着し、 融着され一体化されたロッドを切削して補強絶縁体を形
成することを特徴とする電力ケーブル接続部に使用する
補強絶縁体の製造方法。1. A solid rod is formed by extruding a resin material, and the rod is heat-treated at a temperature equal to or lower than a melting point to release residual strain, and one end of one of the two rods after the heat treatment is released. A convex cone-shaped convex portion is cut and the other one end is cut and formed into a concave cone-shaped concave portion, and an embedding portion for embedding the high-voltage shield electrode in these concave and convex portions is formed by cutting. Reinforcing insulator used in a power cable connecting portion, characterized in that a high-voltage shield electrode is embedded in the portion, two rods are fused, and the fused and integrated rod is cut to form a reinforcing insulator. Manufacturing method.