JPH1038175A - Electrofusion pipe joint and its manufacture - Google Patents
Electrofusion pipe joint and its manufactureInfo
- Publication number
- JPH1038175A JPH1038175A JP8196219A JP19621996A JPH1038175A JP H1038175 A JPH1038175 A JP H1038175A JP 8196219 A JP8196219 A JP 8196219A JP 19621996 A JP19621996 A JP 19621996A JP H1038175 A JPH1038175 A JP H1038175A
- Authority
- JP
- Japan
- Prior art keywords
- member layer
- groove
- heating wire
- resin
- inner member
- 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.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 12
- 238000001746 injection moulding Methods 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 14
- 229920005992 thermoplastic resin Polymers 0.000 claims abstract description 12
- 238000010438 heat treatment Methods 0.000 claims description 30
- 230000002093 peripheral effect Effects 0.000 claims description 8
- 238000004804 winding Methods 0.000 claims description 3
- 229920005989 resin Polymers 0.000 abstract description 23
- 239000011347 resin Substances 0.000 abstract description 23
- 238000000465 moulding Methods 0.000 abstract description 12
- 238000001816 cooling Methods 0.000 abstract description 6
- 239000011800 void material Substances 0.000 abstract description 6
- 229920001083 polybutene Polymers 0.000 abstract description 3
- 229920000915 polyvinyl chloride Polymers 0.000 abstract description 3
- 239000004800 polyvinyl chloride Substances 0.000 abstract description 3
- 230000002950 deficient Effects 0.000 abstract 2
- 239000000243 solution Substances 0.000 abstract 1
- 238000009825 accumulation Methods 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- -1 polypropylene Polymers 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 229920013716 polyethylene resin Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 238000009826 distribution Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5221—Joining tubular articles for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3404—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint
- B29C65/342—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint comprising at least a single wire, e.g. in the form of a winding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5229—Joining tubular articles involving the use of a socket
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3468—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special electrical connectors of windings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3472—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint
- B29C65/3476—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint being metallic
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/05—Particular design of joint configurations
- B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
- B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
- B29C66/112—Single lapped joints
- B29C66/1122—Single lap to lap joints, i.e. overlap joints
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Lining Or Joining Of Plastics Or The Like (AREA)
- Branch Pipes, Bends, And The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ガスや配水配管等
に用いられる熱可塑性樹脂製の管を電気融着接続するた
めの熱可塑性樹脂製管継手の内周面近傍に電熱線を巻回
埋設した電気融着式管継手と、この電気融着式管継手を
得る製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of winding a heating wire near an inner peripheral surface of a thermoplastic resin pipe joint for electrically welding and connecting a thermoplastic resin pipe used for gas or water distribution pipes. The present invention relates to a buried electrofusion type pipe joint and a manufacturing method for obtaining the electrofusion type pipe joint.
【０００２】[0002]
【従来の技術】従来、電気融着式管継手は、図４に示す
ように、熱可塑性樹脂（ポリエチレン樹脂、ポリプロピ
レン樹脂、ポリ塩化ビニル樹脂、ポリブテン樹脂など）
からなる継手本体１の内周面に電熱線２を螺旋状に埋設
し、その両端をコネクターピン３，３に接続したもので
ある。また、図５に巻回埋設された電熱線１と内方部材
層４と外方部材層５の拡大断面図を示す。ところで、電
熱線２にコネクターピン３，３より通電し、これを加熱
することにより同じ熱可塑性樹脂製の管（図示せず）を
電気的に融着し接続するものである。この電気融着継手
は軽くて施工性に優れ、地震等にも強いことからガス用
埋設配管を中心に近年急速に普及しており、現在では呼
び径200mmの大口径配管にまで及んでいる。2. Description of the Related Art Conventionally, as shown in FIG. 4, an electrofusion type pipe joint is made of a thermoplastic resin (polyethylene resin, polypropylene resin, polyvinyl chloride resin, polybutene resin, etc.).
A heating wire 2 is helically buried in the inner peripheral surface of a joint body 1 made of, and both ends thereof are connected to connector pins 3, 3. FIG. 5 is an enlarged cross-sectional view of the wound heating wire 1, the inner member layer 4, and the outer member layer 5. By the way, the heating wire 2 is energized from the connector pins 3 and 3 and is heated to electrically fuse and connect the same thermoplastic resin tube (not shown). These electrofusion joints are lightweight, have excellent workability, and are resistant to earthquakes and the like. Therefore, they have been rapidly spreading in recent years, mainly in buried pipes for gas, and now extend to large-diameter pipes having a nominal diameter of 200 mm.
【０００３】さて、この電気融着式管継手は、従来より
射出成形法で製造されており、例えば、インナー（図４
の符号４）と呼ばれる内方部材層にコアを挿通し、予め
内方部材層の外面に成形されている螺旋溝に電熱線２を
巻回し、この内方部材層をコアと共に成形用金型内にセ
ットし、この上にアウター（図４の符号５）と呼ばれる
外方部材層を射出成形して継手本体１を得るという方法
がとられてきた。[0003] This electrofusion type pipe joint has conventionally been manufactured by an injection molding method.
No. 4), the core is inserted into an inner member layer, and the heating wire 2 is wound around a spiral groove formed in advance on the outer surface of the inner member layer, and the inner member layer is molded together with the core into a molding die. And a joint body 1 is obtained by injection molding an outer member layer called an outer (reference numeral 5 in FIG. 4).
【０００４】また、呼び口径およそ100mm以上の大口径
の電気融着式管継手を限られた設備で能率的に製造する
方法として、本願発明者らが特願平７−６３７８３号に
おいて提案した多層成形法がある。この多層成形法は、
本来、厚肉の継手本体を略均等厚さの樹脂成形層に分割
し、例えば外方部材層５を二つに分割し（図示せず）、
下層の外方部材層の上に上層の外方部材層を重ねて射出
成形して積層することによって継手本体を成形すること
も行われている。これによって、各成形段階での金型内
冷却時間が短縮でき、且つ同時成形が可能となるため生
産性が大幅に向上する。As a method for efficiently manufacturing a large-diameter electro-fused pipe joint having a nominal diameter of about 100 mm or more with limited equipment, a multilayered structure proposed by the present inventors in Japanese Patent Application No. 7-63783 has been proposed. There is a molding method. This multilayer molding method
Originally, the thick joint body was divided into resin molding layers having a substantially uniform thickness, for example, the outer member layer 5 was divided into two (not shown),
In some cases, a joint main body is formed by stacking an upper outer member layer on a lower outer member layer by injection molding and laminating the outer member layer. As a result, the cooling time in the mold at each molding stage can be shortened, and simultaneous molding can be performed, so that productivity is greatly improved.
【０００５】[0005]
【発明が解決しようとする課題】ところが、上記の電気
融着式管継手およびその製造方法では、図６および図７
に示すごとく、内方部材層４の外周面に外方部材層を形
成するために、内方部材層４を成形金型６，６内にセッ
トし、溶融樹脂７が射出成形機の射出筒からゲートを介
して高圧で射出され（図示せず）、キャビティ８内部を
Ｘ方向に進んでいくに伴って（図６から図７の状態に移
行する）、射出方向に対して凹凸のある部分の背後や近
傍に気体の溜まり部が生じ易くなる。特に段差の後ろや
溝の後ろに気体の溜まり部９，９が生じる。気体の種類
として、射出成形時に溶融樹脂７が巻き込む金型内の空
気があり、射出した溶融樹脂から発生するガスも含まれ
る。この溜まり部の気体は、射出成形工程の溶融樹脂の
圧力保持過程および冷却過程の間に一ヶ所に集まって、
ボイドと呼ぶ空洞部１０を形成してしまう。However, in the above-mentioned electrofusion type pipe joint and its manufacturing method, FIGS.
As shown in the figure, the inner member layer 4 is set in molding dies 6 and 6 to form an outer member layer on the outer peripheral surface of the inner member layer 4, and the molten resin 7 is injected into an injection cylinder of an injection molding machine. Are injected at a high pressure through a gate (not shown), and as the inside of the cavity 8 advances in the X direction (transition from the state of FIG. 6 to the state of FIG. 7), a portion having irregularities in the injection direction The gas accumulation portion is likely to be generated behind and in the vicinity. In particular, gas reservoirs 9, 9 are formed behind the steps and behind the grooves. As the type of gas, there is air in a mold into which the molten resin 7 is involved during injection molding, and also includes gas generated from the injected molten resin. The gas in this reservoir collects in one place during the pressure holding process and the cooling process of the molten resin in the injection molding process,
A cavity 10 called a void is formed.
【０００６】このボイドを解消する一つの手段として、
射出圧力とその圧力保持時間および金型内冷却時間を増
せば良いことが分かっている。しかし、この方法では成
形歪みが益々ひどくなるし、また製造タクトが長くなる
という問題がある。As one means for eliminating the void,
It has been found that the injection pressure, the pressure holding time and the cooling time in the mold should be increased. However, in this method, there is a problem that the molding distortion is further increased and the manufacturing tact becomes longer.
【０００７】本発明は上記の問題を解決するもので、ボ
イドのような内部欠陥がなく成形歪みの少ない電気融着
式管継手およびその製造方法を提供することを目的とす
る。An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an electrofusion type pipe joint which has no internal defects such as voids and has less molding distortion, and a method of manufacturing the same.
【０００８】[0008]
【課題を解決するための手段】本発明は、電熱線を溝に
巻回埋設する熱可塑性樹脂製の内方部材層と、この内方
部材層の外面に熱可塑性樹脂製の外方部材層を成形する
電気融着式管継手において、前記溝の深さを前記電熱線
の線径より小さい寸法とする電気融着式管継手である。
尚、上記において、前記溝の深さを前記電熱線の線径の
半分以下の寸法にする方が望ましい。According to the present invention, there is provided an inner member layer made of a thermoplastic resin in which a heating wire is wound and embedded in a groove, and an outer member layer made of a thermoplastic resin is provided on an outer surface of the inner member layer. In the electro-fusion type pipe joint, the depth of the groove is smaller than the wire diameter of the heating wire.
In the above description, it is preferable that the depth of the groove is not more than half the diameter of the heating wire.
【０００９】さらに本発明では、内部に電熱線が巻回埋
設される熱可塑性樹脂からなる電気融着式管継手の製造
方法において、射出成形により溝を有する内方部材層を
形成する工程と、内方部材層の外周面に電熱線を巻回す
る工程と、コネクタピンに前記電熱線を係止する工程
と、電熱線を巻回した内方部材層の外周面に射出成形に
より外方部材層を形成する工程と、前記内方部材層を形
成する工程では前記溝の深さを前記電熱線の線径より小
さい寸法とする電気融着式管継手の製造方法である。
尚、上記において、前記溝の深さを前記電熱線の線径の
半分以下の寸法にする方が望ましい。Further, according to the present invention, there is provided a method of manufacturing an electrofusion type pipe joint made of a thermoplastic resin in which a heating wire is wound and embedded therein, wherein a step of forming an inner member layer having a groove by injection molding; A step of winding a heating wire around an outer peripheral surface of the inner member layer, a step of locking the heating wire to a connector pin, and an outer member formed by injection molding on an outer peripheral surface of the inner member layer around which the heating wire is wound. The step of forming a layer and the step of forming the inner member layer are a method for manufacturing an electro-fused pipe joint in which the depth of the groove is smaller than the diameter of the heating wire.
In the above description, it is preferable that the depth of the groove is not more than half the diameter of the heating wire.
【００１０】[0010]
【発明の実施の形態】以下、本発明の実施の形態を実施
例にもとづき図面を参照して説明する。図１は一実施例
を示す電気融着式管継手の縦断面図であり、図２は巻回
埋設された電熱線と内方部材層と外方部材層の拡大断面
図であり、図３は外方部材層を射出成形する状態を示す
拡大断面図である。本実施例では、熱可塑性樹脂製、例
えばポリエチレン樹脂製、ポリプロピレン樹脂製、ポリ
塩化ビニル樹脂製、ポリブテン樹脂製等で内方部材層４
を射出成形により形成するものとし、内方部材層４の溝
４ａの深さを電熱線２の線径より小さい寸法とし、特に
溝４ａの深さｈを電熱線４の線径ｄの半分以下にする。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments with reference to the drawings. FIG. 1 is a longitudinal sectional view of an electrofusion type pipe joint showing an embodiment, and FIG. 2 is an enlarged sectional view of a wound heating wire, an inner member layer, and an outer member layer. FIG. 4 is an enlarged sectional view showing a state in which an outer member layer is injection-molded. In this embodiment, the inner member layer 4 is made of a thermoplastic resin, for example, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polybutene resin, or the like.
Is formed by injection molding, the depth of the groove 4a of the inner member layer 4 is smaller than the wire diameter of the heating wire 2, and the depth h of the groove 4a is particularly equal to or less than half the wire diameter d of the heating wire 4. To
【００１１】次に図３に示すごとく、内方部材層４の外
周面に外方部材層５を形成するために、内方部材層４を
成形金型６，６内にセットし、溶融樹脂７が射出成形機
の射出筒からゲートを介して射出され（図示せず）、溶
融樹脂７はキャビティ８内部をＸ方向に進んで行く。そ
の際、溝の深さが小さく、電熱線２が溝４ａを埋め尽く
しているため、溶融樹脂７が巻き込む金型内の空気や溶
融樹脂から発生するガスが溝４ａの中に封じ込められる
ことはなくなり、気体の溜まり部が生じることはない。
延いては、気体の溜まり部が発生しないため、溜まり部
の気体が圧力保持過程および冷却過程の間に一ヶ所に集
まって、ボイドを形成することもない。Next, as shown in FIG. 3, in order to form the outer member layer 5 on the outer peripheral surface of the inner member layer 4, the inner member layer 4 is set in molding dies 6, 6, and the molten resin 7 is injected from the injection cylinder of the injection molding machine through a gate (not shown), and the molten resin 7 advances inside the cavity 8 in the X direction. At this time, since the depth of the groove is small and the heating wire 2 fills the groove 4a, the air in the mold in which the molten resin 7 is involved and the gas generated from the molten resin are not sealed in the groove 4a. Disappears, and no gas pool is generated.
As a result, since no gas accumulation portion is generated, the gas in the accumulation portion does not collect in one place during the pressure holding process and the cooling process and does not form a void.
【００１２】以上、本発明の実施例を図面により詳述し
てきたが、具体的な構成はこの実施例に限られるもので
はなく、本発明の要旨を逸脱しない範囲の設計変更等が
あっても本発明に含まれる。Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. Included in the present invention.
【００１３】[0013]
【発明の効果】以上の説明のごとく、本発明の電気融着
式管継手およびその製造方法にあっては、ボイド等の内
部欠陥を確実に無くし、圧力保持時間および金型内冷却
時間を短くして製造タクトを削減でき、延いては成形歪
みの少なくできる。As described above, in the electrofusion type pipe joint and the method of manufacturing the same according to the present invention, internal defects such as voids are surely eliminated, and the pressure holding time and the cooling time in the mold are shortened. As a result, the manufacturing tact can be reduced, and the molding distortion can be reduced.
【図１】 本発明の実施例を示す電気融着式管継手の縦
断面図である。FIG. 1 is a longitudinal sectional view of an electrofusion type pipe joint showing an embodiment of the present invention.
【図２】 本発明の実施例を示す電熱線と内方部材層お
よび外方部材層の拡大断面図である。FIG. 2 is an enlarged cross-sectional view of a heating wire, an inner member layer, and an outer member layer according to the embodiment of the present invention.
【図３】 本発明の実施例を外方部材層の射出成形状態
を示す拡大断面図である。FIG. 3 is an enlarged sectional view showing an injection molding state of an outer member layer according to the embodiment of the present invention.
【図４】 従来の電気融着式管継手の縦断面図である。FIG. 4 is a longitudinal sectional view of a conventional electrofusion type pipe joint.
【図５】 従来の電熱線と内方部材層および外方部材層
の拡大断面図である。FIG. 5 is an enlarged cross-sectional view of a conventional heating wire, an inner member layer, and an outer member layer.
【図６】 従来の外方部材層の射出成形状態を示す拡大
断面図である。FIG. 6 is an enlarged sectional view showing a state of injection molding of a conventional outer member layer.
【図７】 従来の外方部材層の射出成形状態を示す拡大
断面図である。FIG. 7 is an enlarged cross-sectional view showing a state of injection molding of a conventional outer member layer.
１…継手本体， ２…電熱線 ３…コネクターピン， ４…内方部材層 ４ａ…溝， ５…外方部材層 ６…樹脂金型， ７…溶融樹脂 ８…キャビティ， ９…気体の溜まり部 １０…ボイド DESCRIPTION OF SYMBOLS 1 ... Joint body, 2 ... Heating wire 3 ... Connector pin, 4 ... Inner member layer 4a ... Groove, 5 ... Outer member layer 6 ... Resin mold, 7 ... Molten resin 8 ... Cavity, 9 ... Gas accumulation part 10 ... void
Claims (4)
製の内方部材層と、この内方部材層の外面に熱可塑性樹
脂製の外方部材層を成形する電気融着式管継手におい
て、 前記溝の深さを前記電熱線の線径より小さい寸法とする
ことを特徴とする電気融着式管継手。1. An electrofusion tube for forming an inner member layer made of a thermoplastic resin in which a heating wire is wound and embedded in a groove, and an outer member layer made of a thermoplastic resin on an outer surface of the inner member layer. In the joint, the depth of the groove is smaller than the diameter of the heating wire.
以下の寸法にすることを特徴とする請求項１記載の電気
融着式管継手。2. The electro-fusing pipe joint according to claim 1, wherein the depth of the groove is set to be a half or less of a wire diameter of the heating wire.
樹脂からなる電気融着式管継手の製造方法において、 射出成形により溝を有する内方部材層を形成する工程
と、 内方部材層の外周面に電熱線を巻回する工程と、 コネクタピンに前記電熱線を係止する工程と、 電熱線を巻回した内方部材層の外周面に射出成形により
外方部材層を形成する工程と、 前記内方部材層を形成する工程では前記溝の深さを前記
電熱線の線径より小さい寸法とすることを特徴とする電
気融着式管継手の製造方法。3. A method for manufacturing an electro-fusion type pipe joint made of a thermoplastic resin in which a heating wire is wound and embedded inside, wherein a step of forming an inner member layer having a groove by injection molding; A step of winding a heating wire around an outer peripheral surface of the layer; a step of locking the heating wire to a connector pin; and forming an outer member layer by injection molding on an outer peripheral surface of the inner member layer around which the heating wire is wound. And a step of forming the inner member layer, wherein the depth of the groove is smaller than the wire diameter of the heating wire.
以下の寸法にすることを特徴とする請求項３記載の電気
融着式管継手の製造方法。4. The method according to claim 3, wherein the depth of the groove is less than half the diameter of the heating wire.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8196219A JPH1038175A (en) | 1996-07-25 | 1996-07-25 | Electrofusion pipe joint and its manufacture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8196219A JPH1038175A (en) | 1996-07-25 | 1996-07-25 | Electrofusion pipe joint and its manufacture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH1038175A true JPH1038175A (en) | 1998-02-13 |
Family
ID=16354191
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8196219A Pending JPH1038175A (en) | 1996-07-25 | 1996-07-25 | Electrofusion pipe joint and its manufacture |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH1038175A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000213683A (en) * | 1999-01-27 | 2000-08-02 | Nkk Corp | Manufacturing method of electric fusion joint |
-
1996
- 1996-07-25 JP JP8196219A patent/JPH1038175A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000213683A (en) * | 1999-01-27 | 2000-08-02 | Nkk Corp | Manufacturing method of electric fusion joint |
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