JPH1163336A - Reinforced rubber flexible joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide sufficient flexibility and to satisfy water quality standard as drinking water in usage for hot water supply by loading a thin synthetic resin cylindrical body on the inside of a flexible cylindrical body without any adhesion to the inside face between its both ends. SOLUTION: In a flange type reinforced rubber flexible joint 1 for hot water supply, flanges 12, 12 are arranged in both ends of a flexible cylindrical body 11. In the flexible cylindrical body 11 made of rubber which is reinforced by embedding a reinforcing code 111, collar parts 11a, 11a are arranged in both end parts of a bellows-shaped cylindrical part, 11b, and the flanges 12, 12 are fixed to the collar parts 11a, 11a. In a thin cylindrical body 13 made of synthetic resin, collar return parts 13a, 13a are arranged in both ends of a cylindrical part 13b. Without any adhesion on the inside face between both end parts of the flexible cylindrical body 11 excepting connection between the collar parts 11a, 11a and the collar return parts 13a, 13a, the thin cylindrical body 13 is loaded loosely on the inside of the flexible cylindrical body 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced rubber flexible joint that can be used for hot water supply pipes for beverages.

[0002]

2. Description of the Related Art Reinforced rubber flexible joints have conventionally been used in the fields of drainage pipes and water supply pipes as connections between pipes having different levels, expansion joints, and vibration-proof joints. This is a joint that has attracted attention as a vibration joint.

[0003] The flexibility of the reinforced rubber flexible joint is derived from the flexibility of the rubber itself, which is deformed or broken by internal water pressure at the time of water supply or earth pressure at the time of burying. Usually, the rubber forming the tube is used in a state reinforced by a reinforcing material such as a metal wire, a synthetic resin ring or a wire, a synthetic fiber, or a glass fiber cord.

The connecting portion of the reinforced rubber flexible joint with the pipe is generally of a flange type, but may be appropriately changed according to the type of pipe to be connected. For example, when connecting a vinyl chloride resin pipe, the pipe may be bonded with an adhesive by a tapered sleeve-structured receiving port in addition to the flange type pipe.

[0005] As described above, the seismic performance of reinforced rubber flexible joints has been re-recognized, and there has been a demand for use in fields other than conventional drainage and water supply piping. One such field is hot water supply piping for drinking water, but when the rubber material comes into contact with hot water, crosslinking aids and deterioration inhibitors contained in the rubber material are eluted into the hot water, resulting in water quality for drinking water. There was a problem that the standard could not be met, and it could not be used.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, exhibits sufficient flexibility, and can satisfy the water quality standard as drinking water even when used for hot water supply. It has been made for the purpose of providing a reinforced rubber flexible joint.

[0007]

The invention according to claim 1 of the present application (the present invention 1) provides a flexible tubular body made of rubber reinforced with a reinforcing material, at both ends with a flange or a socket. In the reinforcing rubber flexible joint provided with a connecting portion, a thin tubular body made of a synthetic resin is loaded inside the flexible tubular body without being in close contact with an inner surface between both ends thereof. It is a rubber flexible joint.

The invention described in claim 2 of the present application (Invention 2)
Means that the cylindrical thin body made of the above synthetic resin has a glass transition temperature of 110 ° C. or more or a crystal melting point of 120 ° C. or more, and is a standard for drinking water in a dissolution test at 90 ° C. specified by JIS K 6777. The reinforced rubber flexible joint according to the first aspect of the present invention, which has a performance satisfying the following.

In the present invention, as the rubber forming the flexible tubular body, any rubber which can generally form a tubular body within the category of rubber can be used as appropriate. For example, ethylene-propylene rubber, Synthetic rubbers such as acrylonitrile-butadiene rubber and styrene-butadiene rubber are exemplified.

In the present invention, as the reinforcing material for reinforcing the rubber forming the flexible tubular body, those conventionally used as rubber reinforcing materials can be appropriately used. Rings or wires made of synthetic resin, synthetic fibers, cords made of glass fiber, and the like are included.

In the present invention, the synthetic resin forming the thin cylindrical body needs to have heat resistance exceeding 85 ° C., which is a commonly used hot water temperature, and has a glass transition temperature of 1 ° C.
10 ° C. or higher or crystal melting point of 120 ° C. or higher;
What has the performance which satisfies the standard as drinking water in the dissolution test at 90 ° C. specified by IS K 6777 is suitably used, for example, polyethylene, polypropylene,
Examples include polyethylene terephthalate, polyamide, and tetrafluoroethylene.

In the present invention, the thin cylindrical body made of synthetic resin is slack inside the flexible cylindrical body without adhering to the inner surface between both ends thereof, that is, it can follow the bending and expansion and contraction of the joint. It needs to be loaded in a state of being. If it is loaded in a state in which it is in close contact with the inner surface between both ends of the thin cylindrical body, the joint will be broken without being able to follow when bending or expanding and contracting, and as a result, the rubber will come into direct contact with hot water, Crosslinking aids, deterioration inhibitors and the like contained in the material are eluted in the hot water.

[0013]

The reinforced rubber flexible joint according to the first aspect of the present invention is such that a thin cylindrical body made of a synthetic resin is loaded inside the flexible cylindrical body without making close contact with an inner surface between both ends thereof. As a result, the thin cylindrical body can follow the bending or expansion and contraction of the flexible cylindrical body without being damaged, and the hot water directly contacts the flexible cylindrical body mainly composed of a rubber material. Therefore, the crosslinking aid, the deterioration inhibitor and the like contained in the rubber material do not elute into the hot water.

The reinforced rubber flexible joint according to the second aspect of the present invention is the same as the first aspect.
In the above, the cylindrical thin body made of the above synthetic resin has a glass transition temperature of 110 ° C. or more or a crystal melting point of 120 ° C. or more, and a standard as drinking water in a dissolution test at 90 ° C. specified by JIS K 6777 Can satisfy water quality standards as drinking water even when used for hot water supply.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of the present invention. In FIG. 1, reference numeral 1 denotes a flange-type reinforcing rubber flexible joint for hot water supply, and flanges 12 and 12 are provided at both ends of a flexible tubular body 11.

The flexible tubular body 11 is made of rubber reinforced by embedding a reinforcing cord (reinforcing material) 111, and has flanges 11a and 11a at both ends of a bellows-shaped tubular portion 11b. 11a is provided, and flanges 12, 12 are fixed to the flanges 11a, 11a.

The thin cylindrical body 13 is made of a synthetic resin, and is provided with flange return portions 13a and 12a at both ends of a cylindrical portion 13b. Inside the flexible tubular body 11, both flanges 11a, 1
The thin tubular body 13 is loaded without being in close contact with the inner surface between both ends thereof, that is, in a sagging state, except that the flange return portions 13a are connected to 1a.

FIG. 2 is a sectional view showing another example of the present invention. In FIG. 2, reference numeral 2 denotes a socket-type reinforcing rubber flexible joint for hot water supply, and receiving ports 211 are provided at both ends of the flexible tubular body 21 (only one end is shown in FIG. 2). In the receiving port 211, a concave groove 211a for packing is provided along the circumferential direction.

The flexible tubular body 21 is made of rubber reinforced by embedding a reinforcing cord (reinforcing material) 21a over the entire length, and an annular rubber 21b as a reinforcing material is also buried in the center portion. The part is bulged outwardly along the circumferential direction.

The thin cylindrical body 22 is made of a synthetic resin, and is provided with enlarged diameter ends 22a at both ends of a cylindrical part 22b.
In the inside of the flexible tubular body 21, the concave grooves 2 of the receiving ports 211 at both ends are provided.
Except that the enlarged diameter end portion 22a is connected to 11a, the thin cylindrical body 22 is loaded without being in close contact with the inner surface between both ends thereof, that is, in a slack state.

The present invention will be described below with reference to examples.Example 1 Flange type reinforcing rubber flexible joint for hot water supply as shown in FIG.
1 was produced. Poly (p-phenyleneterephthalamide)
Do) (Kepler) Reinforcement cord (reinforcement) 111
Embedded ethylene-propylene-diene copolymer
(Hereinafter referred to as EPDM), length L = 175m
m, outer diameter φA = 96mm, inner diameter φd = 50mm flexibility
A cylindrical body 11 was obtained, and JIS 10 kgf /
cm ^TwoAre mounted.

On the other hand, the ends of a film made of polyethylene terephthalate (hereinafter referred to as PET) having a thickness of 0.2 mm are heat-sealed and joined to form a cylindrical shape. 195mm, 48m outside diameter of cylindrical part
m, a thin-walled cylindrical body 13 having an outer diameter of 76 mm at the flange turning portion was produced.

Inside the flexible tubular body 11, both flanges 11
The thin tubular body 13 is loaded without contacting the inner surface between both ends thereof, that is, in a slack state, except that the flange return portions 13a, 13a are connected to the a, 11a. A reinforced rubber flexible joint 1 was obtained.

With respect to the obtained flange-type reinforcing rubber flexible joint 1 for hot water supply, eccentricity 20 mm, elongation 10 mm, shrinkage 2
After applying a displacement of 0 mm 10 times, it was examined whether an abnormality occurred in the joint. Table 1 shows the results. The obtained flange type flexible rubber flexible joint 1 for hot water supply is
Table 2 shows the results of a dissolution test at 90 ° C. specified in IS K6777.

Example 2 A socket type reinforcing rubber flexible joint for hot water supply as shown in FIG. 2 was produced. Poly (p-phenylene terephthalamide)
(Kepler) Reinforcing cord (reinforcing material) 21a and E
A flexible tubular body 21 made of EPDM with an annular rubber 21b made of PDM embedded therein and having 50A receiving ports 211 at both ends was produced.

At the inside of the flexible tubular body 21, the receiving ports 2 at both ends are provided.
11 except that the enlarged-diameter end portion 22a is connected to the concave groove 211a without contacting the inner surface between both ends thereof, that is, in a slack state, a thin cylindrical body 22 made of PET having a thickness of 0.2 mm. To obtain a socket-type reinforcing rubber flexible joint 2 for hot water supply.

With respect to the obtained socket-type reinforcing rubber flexible joint 2 for hot water supply, eccentricity 20 mm, elongation 10 mm, shrinkage 2
After applying a displacement of 0 mm 10 times, it was examined whether an abnormality occurred in the joint. Table 1 shows the results. The obtained socket type reinforcing rubber flexible joint 2 for hot water supply is
Table 2 shows the results of a dissolution test at 90 ° C. specified in IS K6777.

[0027] Comparative Example 1 except that no provided a thin tubular body Interested flanged hot water supply reinforcing rubber flexible joint as in Example 1, Example 1
A dissolution test at 90 ° C. was performed in the same manner as described above. Table 2 shows the results.
Shown in

Comparative Example 2 A socket-type reinforcing rubber flexible for hot water supply was prepared in the same manner as in Example 2 except that the flexible tubular body and the thin tubular body were adhered in close contact using an adhesive. A joint was obtained. The obtained socket type reinforcing rubber flexible joint for hot water supply has an eccentricity of 20 m.
After giving a displacement amount of m, an elongation of 10 mm, and a contraction of 20 mm ten times, it was examined whether an abnormality occurred in the joint. Table 1 shows the results.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

As described above, the reinforced rubber flexible joint of the present invention exhibits sufficient flexibility and can meet the quality standard of drinking water even when used for hot water supply. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a reinforced rubber flexible joint of the present invention.

FIG. 2 is a sectional view showing another example of the reinforced rubber flexible joint of the present invention.

[Explanation of symbols]

 1, 2 Reinforced rubber flexible joint 13, 22 Flexible tubular body 11a Flange 11b, 21a Reinforcement cord (reinforcing material) 12 Flange 13a Flange return 21b Annular rubber 22a Large diameter end 221 Receptacle

Claims (2)

[Claims] 1. A reinforced rubber flexible joint in which a connecting portion comprising a flange or a receiving port is provided at both ends of a flexible tubular body made of rubber reinforced with a reinforcing material. Without sticking to the inside of the body, the inner surface between its both ends,
A reinforced rubber flexible joint characterized by being loaded with a thin cylindrical body made of a synthetic resin. 2. The thin cylindrical body made of the above synthetic resin has a glass transition temperature of 110 ° C. or more or a crystal melting point of 120 ° C.
° C or higher and 90 as defined in JIS K 6777.
The reinforced rubber flexible joint according to claim 1, wherein the reinforced rubber flexible joint has a performance satisfying a standard as drinking water in a dissolution test at a temperature of ° C.