JPH09317979A - Manufacture of electrically welding joint - Google Patents
Manufacture of electrically welding jointInfo
- Publication number
- JPH09317979A JPH09317979A JP8132941A JP13294196A JPH09317979A JP H09317979 A JPH09317979 A JP H09317979A JP 8132941 A JP8132941 A JP 8132941A JP 13294196 A JP13294196 A JP 13294196A JP H09317979 A JPH09317979 A JP H09317979A
- Authority
- JP
- Japan
- Prior art keywords
- heating wire
- cylindrical body
- insulating sheet
- joint
- locking groove
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D23/00—Producing tubular articles
- B29D23/001—Pipes; Pipe joints
- B29D23/003—Pipe joints, e.g. straight joints
- B29D23/005—Pipe joints, e.g. straight joints provided with electrical wiring
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Branch Pipes, Bends, And The Like (AREA)
- Surface Heating Bodies (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、熱可塑性樹脂から
なる継手の接合面に電熱線が埋設された電気融着継手の
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 an electric fusion joint in which a heating wire is embedded in the joint surface of a joint made of a thermoplastic resin.
【０００２】[0002]
【従来の技術】従来からガス管や給水・給湯管等の合成
樹脂管の接続には、合成樹脂からなる継手本体の両端部
に受口を設け、それぞれの受口内周面に電熱線を埋設し
た電気融着継手が使用されている。この従来継手の製造
方法を図３に基づいて説明すると、次の通りである。2. Description of the Related Art Conventionally, for connecting synthetic resin pipes such as gas pipes and water / hot water supply pipes, sockets are provided at both ends of a joint body made of synthetic resin, and heating wires are embedded in inner surfaces of the sockets. The electric fusion-bonded joint is used. The manufacturing method of this conventional joint will be described below with reference to FIG.
【０００３】まず、熱可塑性樹脂からなる円筒体１ａの
表面に連続したスパイラル状の溝１１ａを刻設し、該ス
パイラル状の溝１１ａに沿って電熱線３ａを嵌入すると
共に、その端部に端子ピン４ａを固定する。次に、電熱
線３ａ及び端子ピン４ａが配設された円筒体１ａを金型
５ａ内にセットし、該金型５ａと円筒体１ａとの間に形
成されたキャビテイ内に溶融樹脂を射出して円筒体１ａ
の外周面に溶融樹脂を一体的に融着させる。First, a continuous spiral groove 11a is formed on the surface of a cylindrical body 1a made of a thermoplastic resin, a heating wire 3a is fitted along the spiral groove 11a, and a terminal is provided at the end thereof. Fix the pin 4a. Next, the cylindrical body 1a provided with the heating wire 3a and the terminal pin 4a is set in the mold 5a, and the molten resin is injected into the cavity formed between the mold 5a and the cylindrical body 1a. Cylinder 1a
The molten resin is integrally fused to the outer peripheral surface of the.
【０００４】[0004]
【発明が解決しようとする課題】ところが、この従来製
法の場合には、キャビテイ内に溶融樹脂を射出したとき
円筒体１ａの外周面が溶融すると共に電熱線３ａが熱膨
張するため、円筒体１ａの外周面に巻回した電熱線３ａ
同志が接近して短絡することがあった。また、この射出
成形の際に電熱線３ａが短絡しなくても、現場での配管
施工の際に電熱線３ａに通電して発熱させたとき、該電
熱線３ａが移動又はキンクすることによって短絡し、十
分な融着接合が得られないことがあった。However, in the case of this conventional manufacturing method, when the molten resin is injected into the cavity, the outer peripheral surface of the cylindrical body 1a is melted and the heating wire 3a is thermally expanded, so that the cylindrical body 1a is expanded. Heating wire 3a wound around the outer peripheral surface of
There was a case where comrades approached each other and short-circuited. Even if the heating wire 3a is not short-circuited during the injection molding, when the heating wire 3a is energized to generate heat during piping work on site, the heating wire 3a moves or kinks to cause a short circuit. However, there are cases where sufficient fusion bonding cannot be obtained.
【０００５】本発明はかかる課題を解決したものであっ
て、溶融樹脂を射出したとき電熱線の短縮を未然に防止
でき、また現場での配管施工の際に電熱線に通電して発
熱させたときにも短絡することがなく、充分な融着接合
が得られる電気融着継手の製造方法を提供するものであ
る。The present invention has been made to solve the above problems, and can prevent the heating wire from being shortened when a molten resin is injected, and the heating wire is energized to generate heat during piping work on site. It is intended to provide a method for manufacturing an electric fusion joint, in which sufficient fusion bonding can be obtained without causing a short circuit even at times.
【０００６】[0006]
【課題を解決するための手段】本発明は、熱可塑性樹脂
からなる継手の接合面に電熱線が埋設された電気融着継
手を製造するにあたり、まず熱可塑性樹脂からなる円筒
体の表面にスパイラル状に連続した係止溝を刻設する。
次に、前記円筒体の表面を絶縁シートで覆い、該円筒体
の外周に電熱線を巻回しつつ絶縁シートを介して係止溝
に電熱線を嵌入させる。そこで、電熱線が巻回された円
筒体を金型内にセットし、該金型と円筒体との間に形成
されたキャビテイ内に溶融樹脂を射出することを特徴と
する。According to the present invention, in producing an electric fusion joint in which a heating wire is embedded in a joint surface of a joint made of a thermoplastic resin, first, a spiral is formed on the surface of a cylindrical body made of the thermoplastic resin. A continuous locking groove.
Next, the surface of the cylindrical body is covered with an insulating sheet, and while the heating wire is wound around the outer periphery of the cylindrical body, the heating wire is fitted into the locking groove through the insulating sheet. Therefore, it is characterized in that a cylindrical body around which a heating wire is wound is set in a mold, and molten resin is injected into a cavity formed between the mold and the cylindrical body.
【０００７】[0007]
【発明の実施の形態】以下、本発明の実施の形態を図面
にて詳細に説明する。図１は本発明で使用する円筒体の
一実施例を示す正面図、図２は電熱線を巻回した円筒体
を金型内にセットした状態を示す要部断面図であって、
図中の符号１はポリエチレン、ポリブテン等の熱可塑性
樹脂からなる円筒体、２は絶縁シート、３は電熱線、４
は端子ピンである。Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view showing an embodiment of a cylindrical body used in the present invention, and FIG. 2 is a sectional view of an essential part showing a state in which a cylindrical body around which a heating wire is wound is set in a mold.
In the figure, reference numeral 1 is a cylinder made of a thermoplastic resin such as polyethylene or polybutene, 2 is an insulating sheet, 3 is a heating wire, and 4 is a heating wire.
Is a terminal pin.
【０００８】本発明では、まず円筒体１の外周面にスパ
イラル状に連続した係止溝１１を刻設する。そして、こ
の係止溝１１の終端と接近した円筒体１の両端外周に支
持リング１２を突設すると共に、該支持リング１２に端
子ピン４を垂直に立設できる嵌入孔１２１を設けてお
く。尚、円筒体１を射出成形によって製造する場合に
は、円筒体１の成形と同時に係止溝１１と支持リング１
２を一体的に成形し、該支持リング１２に嵌入孔１２１
を設けておくとよい。In the present invention, first, the outer peripheral surface of the cylindrical body 1 is engraved with a spirally continuous engagement groove 11. Then, supporting rings 12 are provided so as to project on the outer circumferences of both ends of the cylindrical body 1 which are close to the end of the locking groove 11, and fitting holes 121 for vertically erected the terminal pins 4 are provided in the supporting ring 12. When the cylindrical body 1 is manufactured by injection molding, the locking groove 11 and the support ring 1 are formed simultaneously with the molding of the cylindrical body 1.
2 is integrally molded, and the support ring 12 is fitted with a fitting hole 121.
Should be provided.
【０００９】前記円筒体１にコア６を挿入し、円筒体１
の外周面を絶縁シート２で覆う。絶縁シート２として
は、ポリエチレン、ポリブテン等よりも溶融温度が高い
ポリイミド樹脂、ポリエステル樹脂等からなるシートが
好適に使用できるが、この薄肉シート状に成形した絶縁
シート２を円筒体１の外周面に巻回するか、又は筒状に
成形した絶縁シート２を円筒体１に外挿する。この様に
して円筒体１の外周面を絶縁シート２で覆ってから、円
筒体１の外周に電熱線３を巻回しつつ絶縁シート２を介
して係止溝１１に電熱線３を嵌入させる。The core 6 is inserted into the cylindrical body 1 to
The outer peripheral surface of is covered with an insulating sheet 2. As the insulating sheet 2, a sheet made of polyimide resin, polyester resin, or the like having a higher melting temperature than polyethylene, polybutene, or the like can be suitably used. The insulating sheet 2 that is wound or formed into a tubular shape is externally attached to the cylindrical body 1. In this way, the outer peripheral surface of the cylindrical body 1 is covered with the insulating sheet 2, and then the heating wire 3 is fitted into the locking groove 11 via the insulating sheet 2 while winding the heating wire 3 around the outer periphery of the cylindrical body 1.
【００１０】尚、電熱線３は継手の径サイズに応じて線
径が０．２ｍｍ〜３．０ｍｍのニクロム線等が使用でき
るが、絶縁シート２を介して電熱線３を係止溝１１に嵌
め込んだとき、電熱線３が移動しないような幅と深さを
有する係止溝１１を形成しておくことが肝要である。As the heating wire 3, a nichrome wire or the like having a wire diameter of 0.2 mm to 3.0 mm can be used according to the diameter size of the joint, but the heating wire 3 is inserted into the locking groove 11 via the insulating sheet 2. It is important to form the locking groove 11 having a width and a depth so that the heating wire 3 does not move when fitted.
【００１１】次に、円筒体１の両端外周に設けた支持リ
ング１２の嵌入孔１２１に端子ピン４を嵌め込んで垂直
に立て、それぞれの端子ピン４、４の基部に電熱線３の
端部を接続する。そこで、電熱線３が巻回された円筒体
１を金型５内にセットし、該金型５と円筒体１の外周面
との間に形成されたキャビテイ内に溶融樹脂を射出す
る。すると、キャビテイ内に充満した溶融樹脂が絶縁シ
ート２の表面及び電熱線３と融着接合すると共に、絶縁
シート２の裏面が円筒体１と融着接合する。尚、この射
出成形の際に、円筒体１の外周に巻回された電熱線３は
絶縁シート２で区分されているため、移動又はキンクし
て電熱線３同志が短絡することもない。Next, the terminal pins 4 are fitted into the fitting holes 121 of the support ring 12 provided on the outer circumferences of both ends of the cylindrical body 1 to stand vertically, and the end portions of the heating wire 3 are attached to the bases of the terminal pins 4 and 4, respectively. Connect. Therefore, the cylindrical body 1 around which the heating wire 3 is wound is set in the mold 5, and the molten resin is injected into the cavity formed between the mold 5 and the outer peripheral surface of the cylindrical body 1. Then, the molten resin filled in the cavity is fusion-bonded to the surface of the insulating sheet 2 and the heating wire 3, and the back surface of the insulating sheet 2 is fusion-bonded to the cylindrical body 1. Since the heating wire 3 wound around the outer periphery of the cylindrical body 1 is divided by the insulating sheet 2 during this injection molding, the heating wires 3 do not move or kink and the heating wires 3 are not short-circuited.
【００１２】最後に、金型５を展開してからコア６を引
く抜くと、電熱線３が所定間隔でスパイラル状に巻回さ
れると共に、隣り合う電熱線３同志が絶縁シート２で区
分された電気融着継手が得られる。この電気融着継手を
用いて現場の配管施工を行なう場合、隣り合う電熱線３
同志が絶縁シート２で区分されているため、電熱線３が
発熱して熱膨張しても短絡することがなく、電熱線３へ
の通電時間が継手のサイズ等に応じて予め設定された一
定時間に保たれるため、強固な融着接合が得られる。Finally, when the mold 5 is developed and then the core 6 is pulled out, the heating wire 3 is spirally wound at a predetermined interval, and adjacent heating wires 3 are separated by the insulating sheet 2. An electric fusion-bonded joint is obtained. When performing on-site piping construction using this electric fusion-bonding joint, the adjacent heating wire 3
Since the comrades are separated by the insulating sheet 2, even if the heating wire 3 generates heat and does not expand due to thermal expansion, a short circuit does not occur, and the energization time to the heating wire 3 is set to a predetermined value according to the size of the joint. Since it is kept in time, a strong fusion bond is obtained.
【００１３】[0013]
【発明の効果】以上詳述した如く、本発明は絶縁シート
を介して係止溝に電熱線を嵌入させるので、電熱線が巻
回された円筒体を金型内にセットして溶融樹脂を射出し
ても電熱線同志が短絡することがない。また、本発明に
よって製造された電気融着継手を用いると、電熱線が発
熱したときに移動又はキンクして短絡することもないた
め、電熱線への通電時間が常に一定に保持され、強固な
融着接合が得られる。As described above in detail, according to the present invention, the heating wire is fitted into the locking groove through the insulating sheet. Therefore, the cylindrical body around which the heating wire is wound is set in the mold to melt the molten resin. Even if they are fired, the heating wires will not short-circuit. Further, when using the electric fusion splicing joint manufactured by the present invention, since the heating wire does not move or kink when short-circuited, the energization time to the heating wire is always kept constant, and it is strong. A fusion bond is obtained.
【図１】図１は本発明で使用する円筒体の一実施例を示
す正面図である。FIG. 1 is a front view showing an embodiment of a cylindrical body used in the present invention.
【図２】図２は電熱線を巻回した円筒体を金型内にセッ
トした状態を示す要部断面図である。FIG. 2 is a cross-sectional view of essential parts showing a state where a cylindrical body around which a heating wire is wound is set in a mold.
【図３】図３は従来の製造工程を示す要部断面図であ
る。FIG. 3 is a cross-sectional view of essential parts showing a conventional manufacturing process.
１ 円筒体 ２ 絶縁シート ３ 電熱線 ４ 端子ピン １１ 係止溝 1 cylindrical body 2 insulating sheet 3 heating wire 4 terminal pin 11 locking groove
Claims (1)
熱線が埋設された電気融着継手を製造するにあたり、次
の〜の各工程からなることを特徴とする電気融着継
手の製造方法。 熱可塑性樹脂からなる円筒体（１）の表面にスパイラ
ル状に連続した係止溝（１１）を刻設すること、 前記円筒体（１）の表面を絶縁シート（２）で覆い、
該円筒体（１）の外周に電熱線（３）を巻回しつつ絶縁
シート（２）を介して係止溝（１１）に電熱線（３）を
嵌入させること、 電熱線（３）が巻回された円筒体（１）を金型（５）
内にセットし、該金型（５）と円筒体（１）の外周面と
の間に形成されたキャビテイ内に溶融樹脂を射出するこ
と、1. A method for producing an electric fusion joint, which comprises the following steps (1) to (3) in producing an electric fusion joint in which a heating wire is embedded in a joint surface of a joint made of a thermoplastic resin. . Engraving a spirally continuous locking groove (11) on the surface of a cylindrical body (1) made of a thermoplastic resin, covering the surface of the cylindrical body (1) with an insulating sheet (2),
Fitting the heating wire (3) into the locking groove (11) through the insulating sheet (2) while winding the heating wire (3) around the outer periphery of the cylindrical body (1), the heating wire (3) is wound. The turned cylindrical body (1) is made into a mold (5)
And injecting molten resin into a cavity formed between the mold (5) and the outer peripheral surface of the cylindrical body (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13294196A JP3571849B2 (en) | 1996-05-28 | 1996-05-28 | Manufacturing method of electric fusion joint |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13294196A JP3571849B2 (en) | 1996-05-28 | 1996-05-28 | Manufacturing method of electric fusion joint |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09317979A true JPH09317979A (en) | 1997-12-12 |
| JP3571849B2 JP3571849B2 (en) | 2004-09-29 |
Family
ID=15093084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13294196A Expired - Fee Related JP3571849B2 (en) | 1996-05-28 | 1996-05-28 | Manufacturing method of electric fusion joint |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3571849B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4511683B2 (en) * | 2000-04-24 | 2010-07-28 | 積水化学工業株式会社 | Method for forming electrofusion joint |
-
1996
- 1996-05-28 JP JP13294196A patent/JP3571849B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4511683B2 (en) * | 2000-04-24 | 2010-07-28 | 積水化学工業株式会社 | Method for forming electrofusion joint |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3571849B2 (en) | 2004-09-29 |
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