| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a coupling fitting for improving sealing properties without changing a machining method for the coupling fitting and a tube. SOLUTION: An inner cylinder 12 inserted into and fixed to a communication hole 26 of a coupling fitting 10 project to a bowl-like seal surface 34 side, and a projecting part 12a is formed. When an external thread part 30 of a tube nut 14 is screwed to an internal thread part 32, a tapered tube seal surface 16b formed on the tip of a brake tube 16 is pressed to the seal surface 34. When the tube seal surface 16B is slid along the seal surface 34 after the external thread part 30 is further screwed, the tip of the brake tube 16 is brought in contact with the outer peripheral surface of the projecting part 12A, sliding is stopped, a new seal part is constituted between the tip of the brake tube 16 and the projecting part 12A, and sealing properties are improved.</p> |
