| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an excellent junction between a small diameter hot water supplying polybutene tube and a tube coupling. SOLUTION: In a tube coupling made up of a coupling main body 2 provided with a tube insertion part 6 having both a mounting part 3 at is one end side, and a volute groove 5 at the other end side, and with a screw part 8 threadedly fastening a presser nut 7 in between the aforesaid part and groove, and of a cap nut 17 threadedly engaged with the presser nut 7, a space in a V shape at its depth is formed between the tube insertion part 6 and the presser nut 27. A core 19 which is inwardly fitted in the cap nut 17, has the insertion part of a polybutene tube 22 fitted in, and has projections 21 in its circumference, is formed out of a diameter contracting ring C. When the cap nut is tightened, the core 19 and the polybutene tube 22 are integrally pushed in to the V shaped space 16 so as to be held between the volute groove 5 and each projection 21, sealing and retaining performance for the whole of the insertion part of the tube 22 can thereby be excellent.</p> |
