JP2004278544A - Flexible pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-weight flexible pipe joint made of titanium having excellent durability against chemicals and sea water, flexibility, expansion property, and torsion absorptivity. <P>SOLUTION: An end of a flexible metallic pipe 20 presses and crashes in an axial direction an angular part of a pipe wall to form a flange shape locking part 21. A coupling member 24 of a flange 22 is held between the flange shape locking part 21 and the angular part 25, and a flange body 23 of the flange 22 is prevented from being disengaged by the coupling member 24. The pipe wall of the flexible metallic pipe 20 is made of titanium. An annular member 26 of titanium having a packing seat surface 27 is overlapped to the flange shape locking part 21, whereby padding of a welding 34 is performed over an outer peripheral part of the flange shape locking part 21 and an outer peripheral part of the annular member 26. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flexible fitting, and more particularly to a flexible fitting in which a flange is rotatably attached to an end of a flexible metal pipe having a corrugated pipe wall.
[0002]
[Prior art]
As a conventional example of a flexible pipe joint of this type, a corrugated pipe wall is made of stainless steel, and an angled portion at the end of the flexible metal pipe is crushed in the axial direction and overlapped with the flexible metal pipe to form a flange-shaped lock. It has been known that a flange is provided so that a flange rotatably fitted to an end of a flexible metal tube is prevented from being pulled out by a flange-shaped locking portion. This has the advantage that the process of crushing the end of the flexible metal tube to form a flange-shaped locking portion can be easily performed without causing cracks or the like due to the bending characteristics unique to stainless steel. On the other hand, stainless steel may not exhibit satisfactory properties in terms of durability against chemicals and seawater, which limits its use in harsh environments handling chemicals and seawater, and is flexible due to the heavy weight of stainless steel itself. There is a problem that the pipe joint is heavy and inconvenient to handle. Therefore, an attempt was made to improve the durability against chemicals and seawater by lining a flexible metal pipe whose corrugated pipe wall is made of stainless steel with fluorocarbon resin. It has been found that a decrease in durability due to the above-mentioned phenomenon occurs relatively early.
[0003]
Under such circumstances, a flexible pipe joint having the structure shown in FIG. 3 has been conventionally proposed. In this flexible pipe joint, the corrugated pipe wall of the flexible metal pipe 10 is made of titanium, and a straight section 11 having no chevron is formed at an end of the flexible metal pipe 10 over a predetermined length. An annular member 13 called a loose collar is fixed together with the straight portion 11 by welding (TIG welding) 14 to the end of a titanium sleeve 12 fitted to the outside of the sleeve 11, and the sleeve 12 is rotated by the annular member 13. The flange 15 that is freely fitted outside is prevented from coming off, and the outer end surface of the annular member 13 is formed as a packing seat surface 16. Reference numeral 17 denotes a protective jacket made of a stainless steel wire blade having flexibility, the end of which is fixed to the root of the sleeve 12 using a fixing ring 18.
[0004]
According to the flexible pipe fitting having this configuration, the stainless steel flexible metal pipe having the above-mentioned durability under the harsh environment of handling chemicals, seawater, and the like is formed by forming the corrugated pipe wall of the flexible metal pipe 10 from titanium. Since the pipe wall is corrugated and the flange 15 is rotatable with respect to the flexible metal pipe 10, it is required for a flexible pipe joint interposed in a bent pipe. Performance such as flexibility, elasticity, torsional absorption, and light weight during handling is also satisfied.
[0005]
On the other hand, as a prior example, a straight portion is provided at the end of a flexible metal pipe having a corrugated pipe wall similarly to the flexible pipe joint described in FIG. 3, and a flange body having a packing seat surface is attached to the straight portion, In addition, there is a description of a flexible pipe joint in which a flange is rotatably attached to a straight portion (for example, see Patent Document 1).
[0006]
[Patent Document 1]
Japanese Utility Model Registration No. 3074303
[Problems to be solved by the invention]
However, in the conventional flexible pipe joint described with reference to FIG. 3, the pipe wall of the flexible metal pipe 10 is made of titanium, and the end of the straight portion 11 of the pipe wall is joined to the sleeve 12 together with the annular member 13 by welding. Since the configuration is adopted, it is indispensable that the annular member 13 and the sleeve 12 are made of titanium in order to secure the connection reliability of the welded portion. For this reason, it is inevitable to use titanium, which is more expensive than stainless steel, as the material of the annular member 13 and the sleeve 12. In addition, the sleeve 12 is manufactured by cutting even though the sleeve 12 is cylindrical. There has been a problem that the cost of the product as a flexible pipe joint is extremely high due to the synergistic effect thereof, and the use thereof is often restricted due to such cost.
[0008]
Then, the inventor of the present application prototyped a flexible pipe joint having the structure shown in FIG. 4 or FIG. In this flexible fitting, the sleeve 12 of the flexible fitting described with reference to FIG. 3 is omitted, and instead, a plurality of chevron portions at the end of the flexible metal pipe 20 having a corrugated pipe wall made of titanium are crushed in the axial direction. The flange 22 is divided into a flange main body 23 and an annular connecting body 24, and the annular connecting body 24 is divided into the flange-shaped engaging part 21. It is sandwiched by the chevron 25 adjacent thereto and fixed to the flexible metal tube 20, and the flange body 23 fitted to the flexible metal tube 20 so as to be movable and rotatable in the axial direction is engaged with the connecting body 23 so as to be pulled out. I'm stopping. Further, an annular member 26 made of titanium having a diameter larger than that of the flange-shaped engaging portion 21 and having an outer end surface formed as a packing seat surface 27 is concentrically superimposed on the flange-shaped engaging portion 21, and the annular member is formed. The inner peripheral portion of the flange 26 is fixed to the flange-shaped engaging portion 21 by welding (TIG welding) 28 by welding (TIG welding). Is closing the gap. Reference numeral 32 denotes a protective jacket made of stainless steel, which is fixed to an end of the flexible metal tube 20 using a tightening band 33.
[0009]
According to the flexible pipe joint described with reference to FIG. 4 or FIG. 5, since the sleeve 12 made of titanium described with reference to FIG. 3 is not required, the cost can be easily reduced. However, in this case, since the tube wall of the flexible metal tube 20 is made of titanium, when forming the flange-shaped locking portion 21 at the end of the flexible metal tube 20, the top of the chevron that is crushed in the axial direction is formed. Was bent, and a gap due to a crack was generated at the bent portion, and the fact that fluid leaked from the gap was found. Therefore, a countermeasure has been taken in which the outer peripheral portion of the collar-shaped engaging portion 21 is also overlaid by welding 29 to close the gap due to the crack. According to such a flexible pipe joint, it is lightweight, has excellent durability against chemicals and seawater, and satisfies the flexibility, elasticity, and torsional absorption required for a flexible pipe joint interposed in a bent pipe. I was able to.
[0010]
However, when the inner peripheral portion of the annular member 26 is welded to the inner peripheral portion of the flange-shaped engaging portion 21, the valley portion 31 of the tube wall near the welded portion, that is, the valley shape in which the connecting body 24 is fitted. It has been found that the influence of the welding heat on the portion 31 is remarkable, and that thermal stress may remain in the valley portion 31 to cause a decrease in the strength of the flexible metal tube. When a flexible pipe joint having such a decrease in strength is used at a bent portion of a pipeline, a bending load is concentrated on the valley portion 31 and a crack or a crack occurs in the valley portion 31. It was also found to cause fluid leakage. This point cannot be solved by the technology disclosed in the above-mentioned prior art.
[0011]
The present invention has been made in view of the above problems and circumstances, is lightweight, has excellent durability against chemicals and seawater, and has the flexibility required for a flexible pipe joint interposed in a bent pipe. 4 or 5, while satisfying the elasticity and the elasticity and the torsion absorbency, that is, the build-up by welding 29 on the outer peripheral portion of the flange-shaped engaging portion 21. In addition, after performing the welding work of closing the gap by the crack, the inner peripheral portion of the annular member 26 is fixed to the flange-shaped engaging portion 21 by welding (TIG welding) 28 to the inner peripheral portion. This solves the problem that the welding operation of closing the gap between the two must be performed and the problem that the thermal stress remains in the valley portion 31 in which the connecting body 24 is fitted, resulting in a decrease in the strength of the flexible metal pipe. Can do And to provide a Rekishiburu fitting.
[0012]
[Means for Solving the Problems]
A flexible pipe joint according to the present invention has a flange-shaped locking portion formed by crushing an angle portion of a tube wall in an axial direction at an end portion of a flexible metal tube having a corrugated tube wall and overlapping them, and a flange thereof. A flange is attached to the end of the flexible metal tube while being sandwiched between the chevron and the chevron.
[0013]
The tubular wall is made of titanium, and an annular member made of titanium, whose outer end surface is formed as a packing seat surface, is concentrically superimposed on the flange-shaped locking portion, and the outer peripheral portion of the flange-shaped locking portion. The annular member is coupled to the flange-shaped engaging portion by welding performed over the outer peripheral portion of the annular member, and the welded portion is overlaid to form a bent portion of the outer peripheral portion of the flange-shaped engaging portion. The gap created by the crack generated at the overlapping portion between the annular member and the flange-shaped locking portion is closed.
[0014]
With this configuration, only one welding point is required between the outer peripheral portion of the flange-shaped locking portion and the outer peripheral portion of the annular member, and the welding location is the outer peripheral portion of the flange-shaped locking portion and the annular member. Therefore, the influence of welding heat does not reach the valleys of the pipe wall, and there is no possibility that the flexible metal pipe is accompanied by a reduction in strength due to residual thermal stress. Therefore, it is possible to provide a flexible pipe joint which is low in manufacturing cost, lightweight, excellent in durability against chemicals and seawater, and which satisfies flexibility, stretchability, and torsional absorption.
[0015]
In the present invention, it is preferable that the diameter of the annular member is determined to be equal to the diameter of the flange-shaped locking portion, and the outer peripheral portions of both are arranged in the axial direction of the flexible metal tube. According to this, there is an advantage that welding can be easily and reliably performed over the outer peripheral portion of the flange-shaped locking portion and the outer peripheral portion of the annular member, and the appearance of the welded portion can be easily finished.
[0016]
In the present invention, the flange is fixed to an end of the flexible metal tube by being sandwiched between the flange-shaped locking portion and the chevron portion adjacent to the flange-shaped locking portion; It is preferable that the flexible metal tube is divided into an annular flange main body which is fitted to the flexible metal tube so as to be movable and rotatable in the axial direction, and is prevented from being removed by engaging with the connecting body. According to this, as compared with the case where the undivided flange is attached to the flexible metal pipe, the attaching operation can be performed easily, and when the flexible pipe joint is interposed in the bent pipe, Even if the flange body rotates when absorbing the torsion, there is an advantage that an excessive force due to the rotation of the flange body is less likely to be applied to the flexible metal pipe, and the durability is improved accordingly.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a partially cutaway side view showing a main part of a flexible pipe joint according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a part II in FIG.
[0018]
As can be seen from FIG. 1, this flexible fitting is an improvement on the flexible fitting as the prototype described in FIG. 4 or FIG.
[0019]
That is, the flange-shaped locking portion 21 is formed by crushing a plurality of chevron portions at the ends of the flexible metal tube 20 having the corrugated tube wall made of titanium in the axial direction and overlapping them. In addition, the flange 22 is divided into a flange main body 23 and an annular connecting body 24, and the annular connecting body 24 is sandwiched between the flange-shaped engaging portion 21 and the chevron 25 adjacent thereto to form the flexible metal tube 20. The flange body 23 is fixed so as not to be rotatable, and is fitted to the flexible metal tube 20 so as to be movable and rotatable in the axial direction.
[0020]
In addition, the diameter of a flat annular member 26 made of titanium whose outer end surface is formed as a packing seat surface 27 is set to be equal to the diameter of the flange-shaped engaging portion 21, and then the tubular member 26 is formed into a flange shape. The outer peripheral portions of both are superposed concentrically on the engaging portion 21 and the outer peripheral portions thereof are arranged in the axial direction of the flexible metal tube 20, and the outer peripheral portion of the flange-shaped engaging portion 21 and the outer peripheral portion of the annular member 26 are welded (TIG welding). ) 34 to connect the annular member 26 to the flange-shaped locking portion 21 and to build up the welded portion, thereby reducing the gap caused by the crack generated at the bent portion of the outer peripheral portion of the flange-shaped locking portion 21. The gap formed at the overlapping portion between the annular member 26 and the flange-shaped locking portion 21 is closed. Reference numeral 32 denotes a protective jacket made of stainless steel, which is fixed to the end of the flexible metal tube 20 using a tightening band 33.
[0021]
With this configuration, the sleeve 12 made of titanium described with reference to FIG. 3 becomes unnecessary, and cost reduction is achieved. Also, when forming the flange-shaped locking portion 21 at the end of the flexible metal tube 20, the top of the angled portion that is crushed in the axial direction is bent and a gap caused by a crack generated at the bent portion, the annular member 26 and the flange are formed. Since the gap formed in the overlapping portion with the shape locking portion 21 is closed by the buildup of the welding portion, no fluid leakage occurred. Furthermore, it was lightweight, excellent in durability against chemicals and seawater, and could satisfy the flexibility, elasticity, and torsional absorption required for a flexible pipe joint interposed in a bent pipe.
[0022]
In addition, only one welding point is required between the outer peripheral portion of the flange-shaped locking portion 21 and the outer peripheral portion of the annular member 26, and the welding location is the outer circumference of the flange-shaped locking portion 21 and the annular member 26. In this case, the influence of welding heat does not reach the valley portion 31 of the pipe wall in which the connecting body 24 is fitted, so that thermal stress remains in the valley portion 31 and the flexible metal The situation where the strength of the tube is reduced has disappeared.
[0023]
Although FIG. 1 shows only one end of the flexible pipe joint, the flexible pipe joint of the embodiment has the same structure at the other end as that shown in FIG.
[0024]
【The invention's effect】
As described above, according to the present invention, it is lightweight, has excellent durability against chemicals and seawater, and has the flexibility, elasticity, and torsional absorption required for a flexible pipe joint interposed in a bent pipe. It is possible to provide a satisfactory flexible pipe joint. In particular, it is only necessary to perform welding at one place, and the flexible metal pipe does not deteriorate in strength due to the effect of welding heat. Therefore, a flexible pipe using a titanium flexible metal pipe with excellent durability is used. The joint can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing a main part of a flexible pipe joint according to an embodiment of the present invention.
FIG. 2 is an enlarged view of a portion II in FIG.
FIG. 3 is a partially cutaway side view showing a main part of a conventional flexible pipe joint.
FIG. 4 is a partially broken side view showing a main part of a flexible pipe joint as a prototype.
FIG. 5 is an enlarged view of a portion V in FIG. 4;
[Explanation of symbols]
Reference Signs List 20 flexible metal pipe 21 flange-shaped locking portion 22 flange 23 flange body 24 connecting body 25 chevron 26 annular member 27 packing seat surface 34 welding

Claims (3)

A flange-shaped engaging portion formed by axially crushing and overlapping a chevron portion of the tube wall at an end of a flexible metal tube having a corrugated tube wall, and a chevron portion adjacent to the flange-shaped engaging portion In the state of being clamped by the above, in a flexible pipe joint having a flange attached to the end of the flexible metal pipe,
An annular member made of titanium, in which the pipe wall is made of titanium and whose outer end surface is formed as a packing seat surface, is concentrically superimposed on the flange-shaped engaging portion, and an outer peripheral portion of the flange-shaped engaging portion and the annular portion are formed. The annular member is coupled to the flange-shaped locking portion by welding performed over the outer peripheral portion of the member, and the welded portion is formed at the bent portion of the outer peripheral portion of the flange-shaped locking portion due to the buildup of the welded portion. A flexible pipe joint, wherein a gap formed by a crack and an overlapping portion between the annular member and the flange-shaped locking portion is closed. 2. The flexible pipe joint according to claim 1, wherein a diameter dimension of the annular member is determined to be equal to a diameter dimension of the flange-shaped locking portion, and outer peripheral portions of both are arranged in the axial direction of the flexible metal tube. 3. The flange is fixed to the end of the flexible metal tube by being sandwiched between the flange-shaped locking portion and the chevron portion adjacent to the flange-shaped locking portion, and the flexible metal tube The flexible pipe joint according to claim 1, wherein the flexible pipe joint is divided into an annular flange main body which is fitted so as to be movable in the axial direction and rotatable, and is prevented from being removed by engaging with the connecting body.

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