JPH06265067A - Metallic flexible hose - Google Patents

Abstract

PURPOSE:To facilitate manufacture, to prevent the occurrence of corrosion, and to facilitate bending piping by a method wherein a protection cylinder made of resin is mounted on the outer periphery of a thin stainless bellows pipe, the end part thereof is fixed to the bellows pipe by means of a retainer ring, a coupling is mounted on the end part of the bellows pipe through a rubber packing, and the coupling and the retainer ring are nipped by a box nut. CONSTITUTION:Two O-rings 24 are mounted in the respective annular grooves of the two ends of a thin stainless bellows pipe 21. A protection cylinder 22 made of resin is mounted on an outer periphery except an O-ring 24 mounted part, and securely caulked to the bellows pipe 21 by means of the end part of the bellows pipe and the retainer ring 25. An annular protrusion part 26 is formed in a protruding manner on the outer peripheral surface of the retainer ring 25 and a gap between the end part of a coupling body 23 and the annular protrusion part is securely nipped by means of a box nut 27. The coupling body 23 is mounted on the end of the bellows pipe 21 through the O-ring 24. The protection cylinder 22 is formed by braiding, for example, polyester fibers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible metal flexible hose having joints connected to both ends of a thin-walled stainless steel bellows tube.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional metal flexible hose, including a thin-walled stainless steel bellows tube 1, a metal blade 2 having an outer circumference braided with stainless steel wires, an inner ring 3 and an outer ring 4. Fitting 5 and cap nut 6 for connecting to equipment
It consists of and. At the time of production, the end of the bellows tube 1 is subjected to a stretching machine to finish it into a straight tube, and the inner ring 3
Is inserted into the straight tubular end portion 1a, the outer ring 4 is fitted around the end of the metal blade 2, and the outer ring 4 is compressed and reduced by a press machine so that the metal ring between the inner ring 3 and the outer ring 4 is compressed. -Fix the cord 2, then fit the straight tubular end 1a with the cap nut 6, and open the end of the straight tubular end 1a with the flare machine along the taper surface 6a in the cap nut. At the time of connection, the female screw 6b of the cap nut 6 is screwed into the joint 5 connected to the device, and the expanded portion 1b of the bellows tube 1 is connected to the joint tape.
The surface 5a is brought into close contact with and bonded.

FIG. 4 shows another conventional technique.
This is disclosed in Japanese Patent No. 755. This metal flexible hose has a bellows tube 8, a non-ferrous metal sleeve 9, a metal blade 10 and a metal socket 1 on the outer surface of an annular groove provided in the joint 7.
1 is attached, the diameter of the socket 11 is reduced by compression from the outside of the socket 11 by a press, and the joint 7, the bellows tube 8 and the metal blade 10 are integrally connected.

Generally, on the outside of the thin-walled stainless steel bellows pipes 1 and 8, there are provided metal braids 2 and 10 in the form of braided fine wires made of mild steel or stainless steel, and metal rings from the outer surface of the braid. The bellows tubes 1 and 8 or the joints 5 and 7 at both ends are caulked and fixed to the bellows tubes 4 and 11. This blade 2, 10
Is provided for the purpose of protecting the inner thin-walled stainless steel bellows tube from being damaged from the outside and preventing the bellows tubes 1 and 8 from extending due to the internal inflow fluid pressure in the bellows tube.

[0005]

In the former of the above-mentioned conventional techniques, the straight tubular end portion 1a and the expansion portion 1 are provided at the end portion of the bellows tube 1.
Since b must be provided after cutting the bellows tube, complicated processing steps and various equipment are required. Further, depending on the screwed state of the cap nut 6 at the time of connection, there is a drawback that the connection state is unstable and the sealing property cannot be maintained. Further, in the latter prior art, since the joint 7, the bellows tube 8 and the metal blade 10 are integrated, the bellows tube 8 also rotates when the joint 7 is screwed and connected to a device or the like, so that both sides of the bellows tube 8 are the same. In a flexible hose having a one-piece structure, the joint at the other end cannot be connected to the device, and another joint that allows rotation is necessarily provided between the device and the flexible hose.

Further, in the above-mentioned conventional metal flexible hose, since the metal blade is provided on the outer side of the thin-walled stainless steel bellows tube, when a stray current flows while the electric conductor is in contact with the blade. , There is a problem that the thin-walled stainless steel bellows tube inside is electrolytically corroded and a hole is opened in the bellows tube. Further, due to the bending of the metal flexible hose, the outer surface of the thin-walled bellows tube comes into contact with the outer metal blade, and the outer surface of the bellows tube is scratched, causing local corrosion peculiar to stainless steel from the scratched surface. . Further, when the metal flexible hose is bent and bent, a large bending force is required because the outer stainless steel blade is hard. Further, as a result of using the metal blade, the weight of the entire metal flexible hose is also large.

The present invention solves the above problems, and provides a metal flexible hose which is easy to manufacture, can protect the internal thin-walled stainless steel bellows tube from corrosion, and can be easily connected, and can be easily bent. To do.

[0008]

The gist of the present invention is, in a metal flexible hose in which joints are connected to both ends of a thin-walled stainless steel bellows tube, a resin protective cylinder mounted on the outer circumference of the stainless steel bellows tube, and A rubber packing attached to the annular groove at the end of the bellows tube, a joint body having an end inner surface with a receiving port for receiving the end of the bellows tube fitted with the rubber packing, a protrusion on the outer peripheral surface, and the resin protection A retainer ring having a resin protective cylinder and a bellows tube integrally caulked and fixed on the outer surface of the end of the cylinder, and a cap nut for sandwiching the convex portion of the retainer ring to the end of the joint body. Is a metal flexible hose.

[0009]

The present invention has the above-mentioned structure. When the end of the bellows tube is attached to the receiving port of the joint body screwed into the device to be connected, and the convex portion of the retainer ring is clamped to the joint body with the cap nut. The rubber packing installed in the annular groove at the end of the bellows tube seals the joint body and the bellows tube, and the bellows tube and the resin protective tube are fixed by the retainer ring, and the cap nut is clamped. It is fixed together with the joint body. Therefore, the resistance force of the resin protective cylinder against the force that the bellows tube expands due to the fluid pressure is more reliable than that when the protective tube is covered and fixed only to the bellows tube.

The internal bellows tube made of stainless steel does not need to be provided with a straight tubular portion or a widened portion at the end like a conventional metal flexible hose, and can be assembled in a corrugated shape obtained by cutting the bellows tube. Is easy. Further, as compared with the conventional one in which the expansion taper surface is sealed, a reliable seal can be achieved regardless of the degree to which the cap nut is screwed and tightened.

As a resin protective cylinder mounted on the outer circumference of a stainless steel bellows tube, there is a resin blade formed by knitting polyethylene terephthalate (hereinafter referred to as polyester) fiber. Due to its characteristics, polyester fiber has excellent electrical insulation, heat resistance, weather resistance, and impact resistance, and also has excellent mechanical properties, so even if the inner bellows tube is likely to stretch due to internal fluid pressure, it will be sufficient. Restrain the growth of.

Further, since the resin blade is a tubular body formed by knitting fine fibers, it is sufficiently softer than metal and can flexibly cope with the bending of the inner stainless steel bellows tube and damage the outer surface of the bellows tube. Absent. Further, since the polyester fiber has an electric insulation property, it is electrically insulated even if it comes into contact with a poorly insulated conductor through which a stray current flows, so that the inner bellows tube is not electrically corroded. Polyester fiber is lighter in weight than metal, and it is easy to handle pipes in narrow places such as in-ceiling pipes. Furthermore, since the polyester fiber is flame-retardant and has excellent heat resistance, it can sufficiently withstand the heat of the internal fluid and the place of piping. A braid of polyamide fiber or a glass tube reinforced with glass fiber is also effective.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a metal flexible hose showing an embodiment of the present invention. Reference numeral 21 denotes a thin-walled stainless steel bellows tube. Two O-rings 24 are attached to the annular grooves of the bellows tube 21 at both end portions, and 500 is provided on the outer peripheral surface of the bellows tube 21 excluding the portion where the O-rings 24 are attached. A blade 22 made of polyester fiber, which is formed by knitting polyester fibers of 2,000 denier (weight g per 1 m of length × 9000) into a tubular shape, is attached. At both ends of the blade 22, a metal retainer ring 25 is attached to the outer surface of the blade 22 and is bent into both annular grooves of the two ridges of the bellows tube 21 and caulked to integrally fix the bellows tube 21 and the blade 22. I am doing it.

On the outer peripheral surface of the retainer ring 25, there is provided an annular convex portion 26 projecting outward, and the convex portion 26 is pinched and fixed to the cap nut 27 at the end of the joint body 23. Joint 2
The receiving port 28 of No. 3 is a cylindrical inner surface, and a taper surface 29 is provided at the inlet. The bellows tube 21 having the O-ring 24 is attached to the receiving port 28, and the joint body 23 and the bellows tube 21 are sealed and sealed by the O-ring 24. When the convex portion 26 of the retainer ring is not securely tightened with the cap nut 27, the joint body 23 and the bellows pipe 21 freely rotate in the receiving port 28. Therefore, with the cap nut 27 slightly loosened, the joint body is slightly loosened. Can be screwed into the device to be connected and can be connected.

The resin blade 22 is formed by bundling polyester fibers having a weight g × 9000 of 500 to 2000 per 1 m in a bundle and knitting into a tubular shape, and has high tensile strength and flexibility. It has heat resistance, weather resistance, electrical insulation and is light. When the thickness of the polyester fiber exceeds the above range, the strength performance is deteriorated and the material efficiency is deteriorated. A thin fiber having a thickness less than the above range is excellent in flexibility, but a large number of fibers must be bundled, which is expensive in manufacturing.
The resin blade 22 may be fixed by the retainer ring 25 while being pulled so as to be in close contact with the outer surface of the bellows tube 21, or may be attached with some allowance. Another example of the resin protective cylinder is a braided polyamide fiber braid.
A tube made of polyamide or glass fiber reinforced polyamide is also effective as a protective cylinder.

The inner stainless bellows tube 21 has an inner diameter 21.
The thickness of the stainless steel plate forming the bellows tube is 0.4m
m. The bellows tube 1 has sufficient strength to withstand a fluid pressure of 21 Kg / Cmm when the sprinkler is actuated, and the bellows tube 21 itself formed in this manner has an elongation of 1% compared to that before the internal pressure is applied. It is flexible within the range and can be easily bent. Therefore, even if the outer protective cylinder made of resin is damaged, the flexible hose does not extend. Since the present embodiment has the above-mentioned characteristics, it is suitable for use of a sprinkler pipe in a narrow ceiling space.

[0017]

As described above, the metal flexible hose of the present invention can be easily manufactured without the need for complicated manufacturing steps and equipment unlike the conventional metal flexible hose. Also, it prevents the problems of electrical corrosion and pitting corrosion of the stainless steel bellows tube, has excellent flexibility, and can be formed more lightly. Therefore, it is also suitable for use in a sprinkler-connecting pipe.

[Brief description of drawings]

FIG. 1 is a semi-longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of FIG.

FIG. 3 is a partial sectional view of a flexible hose showing a conventional technique.

FIG. 4 is a partial cross-sectional view showing another conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stainless steel bellows tube 2 Hayama 3 Straight tube part 4 Flare part 5 Cylindrical body 11 Retainer band 21 Bellows tube 22 Resin protective cylinder 23 Joint 24 O-ring 25 Retainer

Claims (1)

[Claims] 1. A metal flexible hose in which joints are connected to both ends of a thin-walled stainless steel bellows tube, wherein a resin protective cylinder mounted on the outer circumference of the stainless steel bellows tube and an end annular groove of the bellows tube. A rubber packing, a joint main body having a receiving opening on the inner surface of the end for receiving the end of the bellows tube equipped with the rubber packing, a convex portion on the outer peripheral surface, and a resin protective tube on the outer surface of the resin protective tube. And a bellows tube by caulking together to fix the retainer ring, and a cap nut that clamps the convex portion of the retainer ring to the end of the joint body.
Su.