JP2002106770A - Coupling structure of flexible tube and tube joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupling structure of a flexible tube and a tube joint capable of repairing at a low cost by repairing or replacing only a damaged part even when a damage occurs by restricting a part to be brought into contact with fluid to a flexible tube while removing a clearance between a metal fitting and the flexible tube with the fluid to remove a cause of corrosion. SOLUTION: This coupling structure of the flexible tube and the tube joint is constituted by a tube joint metal fitting fixed on a tip part of a flexible tube covered with a blade on an outer periphery thereof, an inside large diameter step part formed on an end of the tube joint metal fitting, a sealing material fitted in the inside large diameter step part while extending a forward extending part of the flexible tube to the inside large diameter step, and a caulking ring caulking an end of the blade covered on the outer periphery of the flexible tube with a backward protruding part of the tube joint metal fitting along the shape thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coupling structure between a flexible tube and a pipe joint.

[0002]

2. Description of the Related Art A conventional connection structure between a non-welded flexible tube and a pipe joint is disclosed in, for example, Japanese Patent Laid-Open No.
As shown in No. 92 "Method of connecting flexible tube and pipe joint", when connecting the inner diameter of the pipe joint and the inner diameter of the flexible tube, O
The ring was inserted, the distal end of the flexible tube was inserted, and internal pressure was applied to the distal end to fix the O-ring.

[0003]

However, the above-mentioned conventional structure has the following problems.

[0004] That is, such a conventional connection structure between a flexible tube and a pipe joint has a drawback in that when the O-ring is damaged, the replacement is not limited to the O-ring but the entire product must be replaced.

[0005] In addition, fluid accumulates in the gap between the fitting and the flexible tube and easily corrodes.

Further, since the fluid comes into contact with the fitting, it is necessary to select a material of the flexible tube which is homogeneous with respect to the corrosive property of the fitting, so that the material of the flexible tube is necessarily expensive.

Accordingly, the object of the present invention is to
Solving the above problems, eliminating the cause of corrosion by eliminating the gap between the fluid and the metal fittings and the flexible tube, and limiting the parts where the fluid comes into contact with the flexible tube, for example, the occurrence of damaged parts Even if this is done, the joint structure of the flexible tube and the pipe joint can be repaired at low cost by repairing or replacing only the damaged part.

[0008]

In order to achieve the object of the present invention, a pipe fitting which is fixed to a distal end of a flexible tube having an outer periphery covered with a blade, and a pipe fitting formed at the tip of the pipe fitting are provided. The inner large-diameter stepped portion, the sealing member fitted into the inner large-diameter stepped portion while extending the front extending portion of the flexible tube to the inner large-diameter stepped portion, and the outer periphery of the flexible tube were covered. The end portion of the blade is formed by caulking along the shape of the fitting together with the rear projecting portion of the fitting. Also, the rear protruding portion of the fitting is higher than the peak of the flexible tube.

[0009]

Embodiments and examples of the present invention will be described below with reference to the drawings.

The present invention relates to a pipe fitting 3 fixed to the tip of a flexible tube 2 having an outer circumference covered with a blade 1, an inner large-diameter step 4 formed at the tip of the pipe fitting 3. And a sealing member 6 fitted on the inner periphery of the inner large-diameter step portion 4 while extending the front extension portion 5 of the flexible tube 2 to the inner large-diameter step portion 4. The end of the coated blade 1 is formed by a caulking ring 8 which is caulked along its shape together with the projection 7 of the fitting.

The projecting portion 7 at the rear of the fitting 3 is
As shown in FIG. 3 and FIG. 4, it is necessary to make a projecting portion 7 by erecting the flat portion 12 at the rear end of the joint fitting 3 which is generally commercially available in a press operation in advance. That is, in FIG. 3 and FIG. 4, when the pressing body 16 of the press machine formed in a predetermined shape in advance is pressed in the direction of the arrow in FIG. 3 toward the rear flat part 13 of the fitting 3, the flat part 13 is pressed. The protruding portion 7 is formed along the shape of the pressing portion 17. The height of the protrusion 7 formed at this time is higher than the height of the peak 11 of the flexible tube 2 at the rear of the fitting 3. Therefore, by forming the protruding portion 7 at the rear of the fitting 3, the concave groove 12 is necessarily formed at the rear of the fitting 3. The caulking ring 8 covers the entire area including the end of the blade 1 covered on the outer periphery of the front and rear flexible tube 2 of the protruding portion 7 behind the fitting 3 so that the blade and the fitting 3 are covered with each other. It will be integrated with the rear projection 7.

Moreover, the front extending portion 5 of the flexible tube 2 reaches the inner large-diameter step portion 4 formed at the tip of the fitting 3, and the sealing material 6 is fitted into the inner periphery of the inner large-diameter step portion 4. Therefore, the fluid is limited only to the seal member 6 and the inner periphery of the flexible tube 2. Since the influence of corrosion by the fluid is the flexible tube 2 and the sealing material 6, the material of the flexible tube 2 can be selected from corrosion-resistant stainless steel from the viewpoint of preventing corrosion. Further, when the sealing material 6 is damaged, the fitting position of the sealing material 6 is the tip end of the fitting 3 so that replacement thereof is easy. As the sealing material 6, an annular sealing material such as an O-ring or rubber packing is used. In addition, FIG.
Although an O-ring is shown in FIGS. 2 and 5 as the sealing material, rubber packing may be used instead of the O-ring.

Another pipe 9 is provided in front of the pipe joint through a stub nut 10. A owl nut 10 is screwed onto the outer periphery of the front of the fitting. The bulging portion of the tubular body 9 is engaged with the inner periphery of the owl nut 10 at a position corresponding to the tapered portion 14, thereby preventing the other tubular body 9 from being detached and adjoining the bulging portion 15 of the tubular body 9. A sealing material 6 fitted to the front end of the pipe fitting is sealed around the outer periphery of the pipe 9.

According to the first aspect of the present invention, there is provided a joint structure between a flexible tube and a pipe joint which is fixed to a distal end portion of a flexible tube having an outer periphery covered with a blade, and which is formed at a distal end of the tube joint. An inner large-diameter step portion, a sealing material fitted into the inner large-diameter step portion while extending a front extension portion of the tube constituting the flexible tube to the inner large-diameter step portion, and an outer periphery of the flexible tube. Since the end portion of the coated blade is formed by caulking formed by caulking the end portion of the fitting together with the protrusion of the fitting, the fluid only flows through the inner diameter of the tube made of a single material except for the sealing material, By selecting a corrosion-resistant stainless steel for the material of this tube, it is possible to make the joint structure of the flexible tube and the pipe joint that have corrosion resistance as a whole Kill. Also, since the sealing material is fitted into the inlet of the fitting, it can be easily replaced if it is damaged. In the connecting structure of the flexible tube and the pipe joint according to the second aspect, since the rear protruding portion of the pipe fitting is higher than the ridge of the flexible tube, the blade can be securely fixed to the pipe fitting by the caulking ring. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a connection state between a flexible tube and a fitting.

FIG. 2 is an enlarged sectional view of a distal end extension of a flexible tube.

FIG. 3 is a cross-sectional view showing a state before the rear protruding portion of the fitting is formed by a pressing step.

FIG. 4 is a cross-sectional view showing a state in which a rear protruding portion of the fitting is formed by a pressing process.

FIG. 5 is a cross-sectional view showing a state in which another pipe is piped in the present invention.

[Explanation of symbols]

 1. . Blade 2. . Flexible tube 3. . Pipe fitting 4. . Inside large diameter step 5. . Extension part 6. . Seal material 7. . Protrusion 8. . Caulking ring 9. . Tubular body 10. Owl nut 11. Yamabe 12. Groove 13. Flat part 14. Tapered part 15. Bulge 16. Pressed body 17. Pressing part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G004 DA15 EA03 FA04 GA04 3H017 CA03

Claims (2)

[Claims] 1. A fitting which is fixed to a tip of a flexible tube having an outer periphery covered with a blade, an inner large-diameter step formed at the tip of the fitting, and a front extension of the flexible tube. The sealing member fitted into the inner large-diameter step portion and the end of the blade coated on the outer periphery of the flexible tube together with the rearward projecting portion of the pipe joint fitting are attached to the inner large-diameter step portion. A coupling structure of a flexible tube and a pipe joint, comprising caulking formed along a shape. 2. The joint structure of a flexible tube and a pipe joint according to claim 1, wherein the rear projecting portion of the pipe fitting is higher than the peak of the flexible tube.