JPH0512881U - Metal flexible tube reinforcement structure - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent fatigue damage by preventing displacement due to pressurization of the connecting end pipe wall of metal flexible pipe and thermal deterioration due to welding heating. A reinforcing ring 2 having a corrugated portion 2b fitted to a corrugated trough portion 1b of an outer peripheral surface of a pipe wall in the vicinity 1a of an end portion of a metal flexible tube 1 is mounted, and a blade 3 mounted on the outer surface thereof, Each end of the mounting ring 4 and the reinforcing ring 2 is welded 5 and connected to the end of the metal fitting 6 by welding 7 to prevent displacement and heat deterioration of the pipe wall near the metal flexible pipe end 1a and fatigue damage. Prevent.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of a connecting end of a flexible metal tube, and particularly stress concentration or end generated by displacement of a pipe wall due to working pressure or bending of the connecting end of the flexible metal tube or pressure change. The present invention relates to a reinforcing structure of a metal flexible tube capable of preventing fatigue damage and the like due to heat deterioration during welding of parts.

[0002]

[Prior Art]

 Conventionally, a metal flexible tube such as a flexible tube is connected to a metal fitting or connected to a device. At the time of this connection, as shown in FIG. 7, a stainless steel blade 12 is first placed on the outer surface of the flexible tube 11, and a stainless steel ring 13 is attached to the end of the flexible tube 11. Then, the flexible tube 11, the blade 12 and the ring 13 are joined by welding 14 on the end surface of the flexible tube 11 having the ring 13 mounted thereon. Next, the end portion of the flexible tube 11 having the above structure and the metal fitting 15 made of stainless steel or mild steel are connected by welding 16.

By the way, in the above-mentioned conventional technique and structure, as shown in FIG. 8, by applying pressure to the tube wall near the end of the flexible tube 11, particularly, two to three ridges from the tube end, the pressure is increased during use. Alternatively, the tube wall is displaced (arrow B) due to bending or vibration, and the strength of the end portion of the tube 11 is reduced due to the stress concentration caused by this displacement. In addition, the end portion of the tube 11 is thermally deteriorated by heating at high temperature during welding and its strength is reduced. As described above, in the vicinity of the end of the flexible tube 1, due to the synergistic effects of displacement due to pressurization and bending change and strength deterioration due to thermal deterioration as described above, strength decrease near the end of the tube 11 occurs early, This is a problem because the tube 11 may crack and fatigue damage may occur frequently, causing leakage of internal fluid and fluid pressure. By the way, more than 50% of the breakage during use of the flexible tube is fatigue damage at the tube end, and most of the cracks are in the range from the weld to two or three ridges.

[0004]

[Problems to be solved by the device]

 The present invention has been made to solve the above-mentioned problems, and changes in pressure near the end of a flexible metal tube, displacement of the pipe wall due to bending, etc., and strength reduction due to stress concentration caused by operating pressure, etc. This prevents heat deterioration during welding, prevents fatigue damage to the flexible metal tube, and improves the durability of the flexible metal tube.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a structure in which a reinforcing member that is fitted to the corrugations of the metal flexible tube and prevents displacement of the wall is attached to the tube wall near the end of the metal flexible tube. ..

[0006]

【Example】

 Hereinafter, a first embodiment of a metal flexible tube reinforcing structure according to the present invention will be described with reference to FIG. FIG. 1 is a half sectional side view of a reinforcing structure for a metal flexible tube according to a first embodiment of the present invention. In the figure, reference numeral 1 is a flexible tube which is a kind of metal flexible tube. A reinforcing ring 2, which is a reinforcing member, is attached to the outer surface of the flexible tube 1 near the end portion 1a.

The reinforcing ring 2 is made of stainless steel or the like, and is divided into two parts in the axial direction as shown in FIG. 2. After being attached to the flexible tube 1, the two parts of the reinforcing ring 2 are provided on the opening side. The seams are spot welded 2a. On the inner peripheral surface of the reinforcing ring 2, there is formed a corrugated section 2b which fits into a trough section 1b on the outer surface of the corrugated tube wall of the flexible tube 1.

On the outer surface of the flexible tube 1, a blade 3 made of stainless steel or the like is mounted from the outer surface of the end portion of the reinforcing ring 2 to the outer surface of the other end portion (right side in FIG. 1) of the flexible tube 1. Has been done.

A mounting ring 4 is mounted on the outer surface of the blade 3 in the vicinity 1 a of the end of the flexible tube 1 having the reinforcing ring 2 mounted thereon, and the flexible tube 1, the reinforcing ring 2, the blade 3 and the mounting The ends of the ring 4 are joined by welds 5.

To connect the flexible tube 1 configured as described above to the metal fitting 6, the end of the mounting ring 4 on the metal fitting 6 side and the end of the metal fitting 6 are connected by welding 7.

According to the reinforcing structure of the metal flexible tube of the first embodiment, the reinforcing ring 2 having the corrugated 2b fitted in the corrugated valley 1b of the flexible tube 1 is provided in the vicinity of the end 1a of the flexible tube 1. Since it is mounted, it is possible to prevent the displacement of the tube wall near the end 1a of the flexible tube 1 due to pressure, bending, vibration, or the like. Therefore, the strength is not reduced due to displacement such as pressurization, and fatigue damage can be prevented.

Further, since the mounting ring 4 and the metal fitting 6 are connected by the welding 7, the heating by the welding 7 does not directly affect the end portion 1a of the flexible tube 1 and the flexible tube 1 end portion 1a is close. Fatigue damage can be prevented without lowering the strength due to heating.

As described above, since it is possible to prevent the strength decrease due to the displacement of the end portion 1a of the flexible tube 1 and the strength decrease due to welding heating, the synergistic effect of both preventions further deteriorates the strength of the flexible tube 1 near the end portion 1a. It is prevented and the durability of the flexible tube 1 is significantly improved as compared with the conventional product. Even if the adjacent portion 1c near the end 1a of the flexible tube 1 is deformed to some extent due to use or the like, the deformation is not large, and the strength is not directly deteriorated by the heating as described above. The original strength can be maintained, so that fatigue damage does not occur.

Next, a second embodiment of the present invention will be described with reference to FIG. The same components are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 1 in the figure is a flexible tube. On the outer surface of the end of the flexible tube 1, a reinforcing ring 2 having the same structure as in the first embodiment is mounted.

The outer surface of the flexible tube 1 is covered with a blade 3 made of stainless steel or the like from the outer surface of the metal fitting 6 to the other end of the flexible tube 1 through the outer surface of the reinforcing ring 2. The ends of the flexible tube 1, the reinforcing ring 2 and the blade 3 are joined by welding 5.

An attachment ring 8 is attached to the outer surface of the metal fitting 6 slightly separated from the end of the flexible tube 1 via the blade 3.

The connecting means between the flexible tube 1 and the metal fitting 6 connects the blade 3 on the end side of the flexible tube 1 and the end of the metal fitting 6 by welding 9, and at the same time, the flexible tube 1 of the mounting ring 8 is connected. The end on the opposite side and the metal fitting 6 are connected by welding 10 via the blade 3.

According to the reinforcing structure of the metal flexible tube of the second embodiment, the reinforcing ring 2 does not cause displacement of the vicinity 1a of the flexible tube 1 and the blade 3 is disposed at the end of the flexible tube 1. Since the metal fitting 6 and the metal fitting 6 are connected by welding 9, heat deterioration due to welding does not occur in the vicinity 1a of the end portion of the flexible tube 1. Furthermore, since the mounting ring 8 and the metal fitting 6 are connected by welding 10 via the blade 3 at a position separated from the flexible tube 1, heat deterioration due to welding is caused in the vicinity 1a of the end of the flexible tube 1. It does not occur at all.

As described above, according to the reinforcing structure of the metal flexible tube of the second embodiment, in addition to the displacement prevention by the reinforcing ring 2, the welding of the connection between the blade 3 and the metal fitting 6 at the end of the flexible tube 1 is performed. The heat deterioration is prevented by 9 and the heat deterioration of the vicinity 1a of the end of the flexible tube 1 is prevented by the welding 10 between the mounting ring 8 and the metal fitting 6 at a position separated from the end of the flexible tube 1. In this way, the synergistic effect of the above three factors can further prevent the strength reduction in the vicinity 1a of the end portion of the flexible tube 1, so that fatigue damage in the vicinity 1a of the end portion of the flexible tube 1 can be further prevented and the durability of the flexible tube 1 can be improved. The performance is further improved compared to conventional products. The other effects are the same as in the first embodiment.

In the first and second embodiments, the reinforcing ring 2 is divided into two, but depending on the corrugated structure of the flexible tube 1, for example, one mountain (discontinuous mountain) or spiral shape is used. The structure is not limited to two divisions, but may be divided into a plurality of divisions such as three divisions. Further, the spiral shape may not be divided and may be a screw type as shown in FIG. 4, or as shown in FIG. 5, the inner peripheral surface of the pipe wall, or as shown in FIG. It may be attached to both sides of the outer peripheral surface and the inner peripheral surface of the pipe wall. In short, any material can be used as long as it can be fitted into the corrugated concave portion or convex portion of the tube pipe wall by the reinforcing ring 2 to prevent displacement of the pipe wall near the tube end portion.

The location of the welding 10 of the attachment ring 8 of the second embodiment may be on the end side of the flexible tube 1 as long as it is not subject to thermal deterioration. Also in the second embodiment, it is of course possible to attach a tightening ring or the like to the outside of the reinforcing ring 2.

The materials such as the reinforcing ring 2 and the attachment rings 4 and 8 used in the embodiment of the present invention are not limited to those of the embodiment.

Further, in the embodiment, the example of connecting the flexible tube 1 and the metal fitting 6 has been described, but it is also applicable to the connection between the flexible tubes or the connection with other equipment, and the connecting means. Is applicable not only to welding but also to other means.

[0024]

[Effect of the device]

 As described above, the reinforcing structure for a metal flexible tube according to the present invention is a reinforcement for fitting the pipe wall near the end of the metal flexible pipe to the waveform of the metal flexible pipe to prevent displacement of the pipe wall. Since the member is attached, displacement of the pipe wall near the end of the metal flexible pipe due to pressure, etc. can be prevented, and strength deterioration due to heat deterioration that occurs during welding etc. does not occur. Fatigue damage can be prevented, and the durability of the metal flexible tube is significantly improved compared to the conventional one.

[Brief description of drawings]

FIG. 1 is a half sectional side view of a reinforcing structure for a metal flexible tube according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a two-divided reinforcing ring.

FIG. 3 is a half cross-sectional side view of a reinforcing structure for a metal flexible tube according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a modified example of a reinforcing ring.

FIG. 5 is a partial half sectional view showing a modified example of the reinforcing structure.

FIG. 6 is a partial half cross-sectional view showing a modified example of the reinforcing structure.

FIG. 7 is a half cross-sectional side view showing a conventional example.

FIG. 8 is a partial cross-sectional view of a conventional example.

[Explanation of symbols]

 1 flexible tube (metal flexible tube) 1a near end of flexible tube 2 reinforcing ring (reinforcing member) 4 mounting ring 6 metal fittings 8 mounting ring

Claims (1)

[Scope of utility model registration request] 1. A metal flexible tube characterized in that a reinforcing member fitted to a corrugated shape of the metal flexible tube to prevent displacement of the wall is attached to a tube wall near the end of the metal flexible tube. Reinforced structure.