ELECTRO FUSION JOINT

To avoid troubles occurring during construction or difficulty in transportation in an electro fusion joint.SOLUTION: An electro fusion joint 250 includes a fusion part in which a heating wire 300 is inserted into a cut groove spirally formed on an inner peripheral surface of a thermoplastic resin pipe into which a resin pipe to be connected thereto is inserted. The fusion part is provided on at least one of axial ends (both ends in this example) of the electro fusion joint 250 so as to be able to energize the heating wire 300 (via a terminal pin). At the fusion part, an outward path in which the spiral proceeds in an outward direction from the opening side of the electro fusion joint 250 to the opening side opposite to the opening and a return path provided in a reverse direction are formed by one heating wire 300. The electro fusion joint 250 includes recessed parts 252, in each of which the inner peripheral surface is recessed, on the inner peripheral surface at the opening side relative to the fusion part.SELECTED DRAWING: Figure 14 【課題】電気融着継手における施工時のトラブルまたは運び辛さを回避する。【解決手段】電気融着継手２５０は、接続相手の樹脂管が挿入される熱可塑性の樹脂管の内周面に螺旋状で形成された切欠き溝に電熱線３００が挿入された融着部を備える。この融着部は、電気融着継手２５０の軸方向の少なくとも一方（ここでは両方）の端部側に、電熱線３００に（ターミナルピンを経由して）通電可能に設けられる。この融着部において、電気融着継手２５０の開口部側から開口部の逆側の開口部側への往路方向へ螺旋が進行する往路と往路方向と逆方向の復路とが１本の電熱線３００で形成されている。電気融着継手２５０は、融着部よりも開口部側の内周面に、内周面がへこんだ凹部２５２を備える。【選択図】図１４