JP2001159478A - Flexible expansion pipe and flexible expansion joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible expansion pipe, having superior expansiveness and eccentric characteristic and improved durability and vibration preventive characteristic, while maintaining superior characteristics including heat resistance of a bellows metal pipe, and a flexible expansion joint using the same. SOLUTION: This flexible expansion pipe comprises the bellows metal pipe 1, a heat resistant rubber layer 2 covering the outer periphery thereof and a reinforcing layer 3 embedded in the heat resistant rubber layer 2 and formed with a group of metal wire rods 3a, 3b which are arranged in mutually opposite directions without being spirally woven. The flexible expansion joint comprises using the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible expansion tube and a flexible expansion joint using a bellows-like metal tube.

[0002]

2. Description of the Related Art Conventionally, various flexible expansion joints have been used for the purpose of preventing damage to connection pipes or their connection parts due to displacement during construction and uneven settlement of the ground. As such flexible expansion joints, those using a bellows-like metal tube or rubber hose for the flexible expansion and contraction portion are known, but the former is used for applications requiring heat resistance, chemical resistance, oil resistance, etc. Type has been mainly used.

In the above-mentioned metal bellows type, a SUS bellows tube is generally used. As shown in FIG. 5 (a), a SUS blade 20 is woven into a cylindrical shape for the purpose of reinforcing internal and external pressures. The reinforcing layer 21 was provided on the outer peripheral portion of the bellows tube. In addition, as shown in FIG. 5B, a reinforcing layer 23 in which a plurality of SUS wire rods 22 are woven in a cylindrical shape instead of the blade 20 is provided. The reinforcing layer restrains the diameter expansion and the axial elongation of the SUS bellows tube, and there is no adhesive layer or filler layer interposed between the two.

[0004]

However, in the metal bellows type described above, the reinforcing layer is formed by weaving a metal blade or the like, and the angle between the intersecting blades can be slightly changed. The joints were not easily deformed when the pipes were expanded or contracted or eccentric, and thus the connection pipes and their connection parts were easily damaged. In the case of using a SUS wire in place of the blade, although this phenomenon is somewhat improved, the point in which the interval between a plurality of arranged wires does not change is the same as in the case of the blade. The joint deformation during eccentricity was not sufficient.

Further, due to the structure of the bellows-like metal tube, stress tends to concentrate locally, and the portion is liable to breakage due to metal fatigue. Further, the combination of the bellows-shaped metal pipe and the above-mentioned reinforcing layer cannot attenuate the vibration (particularly high-frequency vibration) transmitted through the fluid or the connection pipe, and is therefore unsuitable as a vibration-proof joint. Problems such as metal fatigue occurring in a short period of time by joints used therearound are likely to occur.

On the other hand, Japanese Patent Application Laid-Open No. 11-294658 discloses a flexible expansion joint in which a bellows-like metal tube is provided inside a rubber hose having a reinforcing structure, and a foamed rubber layer having heat insulation is interposed between the two. It has been disclosed. However, since the heat resistance of the rubber hose itself has not been improved, the heat resistance cannot be sufficiently improved only by the interposition of the foamed rubber layer.

Accordingly, an object of the present invention is to provide a flexible telescopic tube which has excellent elasticity and eccentricity, and further has improved durability and vibration-proofing characteristics while utilizing the characteristics of the bellows-like metal tube such as excellent heat resistance. , And a flexible expansion joint using the same.

[0008]

The above object can be achieved by the present invention as described below. That is, the flexible telescopic tube of the present invention is a bellows-like metal tube, a heat-resistant rubber layer covering the outer periphery thereof, and embedded in the heat-resistant rubber layer, and are arranged without being woven in a spiral shape in the opposite direction. And a reinforcing layer composed of a group of metal wires. Here, the heat-resistant rubber refers to a rubber that is more excellent in heat resistance than a general-purpose rubber used in a conventional rubber hose, and has a usable temperature range of 100 ° C.
Including those that exceed

In the above, it is preferable that the heat resistant rubber layer is formed of silicone rubber.

It is preferable that an inner peripheral portion of the heat-resistant rubber layer is filled in a concave portion on an outer peripheral surface of the bellows-like metal tube.

On the other hand, a flexible expansion joint according to the present invention is a flexible expansion joint comprising a flexible expansion part and a connection part of a mating pipe provided at both ends thereof, wherein the flexible expansion part is any one of the above flexible parts. It is characterized by being formed by a telescopic tube.

Further, according to the present invention, there is provided a flexible expansion joint having a flexible expansion part and a connection part of a mating pipe provided at both ends thereof, wherein the flexible expansion part is any one of the above-mentioned ones. It is formed of a flexible telescopic tube, and is locked by a locking member that can be folded in the vicinity of the end of the metal wire into an annular concave portion at the end of the bellows-shaped metal tube and arranged annularly. Is preferred.

According to the flexible telescopic tube of the present invention, since the outer circumference of the bellows-like metal tube is covered with the heat-resistant rubber layer, the vibration generated in the bellows-like metal tube can be attenuated. Since the heat-resistant rubber is used, the heat resistance of the bellows-like metal tube is not easily damaged. In addition, since the metal wire groups embedded in the heat-resistant rubber layer are arranged without being woven in a spiral in the opposite direction, the angle of the intersecting metal wires can be easily changed, and the parallel metal wires can be changed. Since the spacing between the wires can be easily changed, sufficient reinforcement and eccentricity are possible while the reinforcing layer performs internal and external pressure reinforcement. The heat-resistant rubber layer reinforced in this manner restrains the bellows-shaped metal tube from the outer periphery, so that the durability can be improved. As a result, it was possible to provide a flexible telescopic tube having excellent elasticity and eccentricity, and further improved durability and vibration-proof characteristics, while utilizing the characteristics of the bellows-like metal tube such as excellent heat resistance.

When the heat-resistant rubber layer is formed of silicone rubber, the heat resistance of silicone rubber is much higher than that of other rubber materials, so that the heat resistance can be further improved. For this reason, it can be used at 200 ° C. or higher, and is particularly useful for flexible expansion joints and the like used in sanitary facilities and hot water facilities used at high temperatures (70 to 120 ° C.). Moreover, silicone rubber is not so expensive, and various raw materials are available from liquid to solid.
There are many advantages in manufacturing.

When the inner peripheral portion of the heat-resistant rubber layer is filled in the concave portion on the outer peripheral surface of the bellows-like metal tube, the heat-resistant rubber present in the concave portion on the outer peripheral surface of the bellows-like metal tube is:
Since the local stress concentration generated in the bellows-like metal pipe is dispersed, breakage due to metal fatigue hardly occurs, and the durability can be further improved.

On the other hand, according to the flexible expansion joint of the present invention,
Since the flexible expansion and contraction portion is formed of the flexible expansion and contraction tube of the present invention, the above-described effects provide excellent elasticity and eccentricity while utilizing the characteristics of the bellows-like metal tube such as excellent heat resistance. In addition, durability and vibration-proof characteristics are further improved.

Further, the flexible expansion and contraction portion is formed of the flexible expansion and contraction tube according to any one of the above, and the vicinity of the end of the metal wire is formed in an annular concave portion at the end of the bellows-like metal tube. If it is locked by a locking member that can be folded and arranged in a ring, use the annular recess of the bellows-like metal tube,
With a simple structure in which the metal wire is folded and locked by the locking member, high strength is obtained with respect to the pull-out force, and the strength and durability of the joint end can be efficiently increased.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in the order of a flexible telescopic tube and a flexible expansion joint.

[Flexible Telescopic Tube] As shown in FIG. 1, a flexible telescopic tube of the present invention comprises a bellows-like metal tube 1, a heat-resistant rubber layer 2 covering the outer periphery thereof, and a heat-resistant rubber layer 2 And a reinforcing layer 3 composed of metal wire groups 3a and 3b, which are arranged without being woven in a spiral shape in the opposite direction.

The bellows-like metal tube 1 is called a bellows tube, a corrugated tube, or the like, and is a metal tube in which thin portions (recesses 1a) and thick portions (projections 1b) are provided alternately in the longitudinal direction. As shown in FIG. 1, other than the one in which the concave portion 1a is formed in an annular shape, the one in which the concave portion 1a is formed in a spiral shape can be used. The material constituting the bellows-like metal tube 1 is appropriately selected according to the fluid to be passed, but stainless steel, plated iron, aluminum, brass, and the like can be used, and generally, stainless steel is used. Are preferred in terms of corrosion resistance.

The thickness of the bellows-like metal tube 1 is appropriately set in consideration of the internal pressure and the like, but a thickness of 0.2 to 1.0 mm is preferably used. Further, the inner diameter and length are appropriately set according to the application.
About 2 to 0.6 mm is preferable.

The heat-resistant rubber layer 2 covers the outer periphery of the bellows-like metal tube 1, and its inner peripheral portion does not necessarily need to be filled in the concave portion 1 a on the outer peripheral surface of the bellows-like metal tube 1. However, for the above-mentioned reason, it is preferable that the concave portion 1a is filled as shown in FIG.

As the rubber material forming the heat-resistant rubber layer 2, any rubber material can be used as long as the usable temperature range exceeds 100 ° C., but silicone rubber (including fluorinated silicone rubber) can be used. ), Fluorine rubber and the like are particularly preferred because of their high heat resistance, and silicone rubber is most preferred. The hardness of the heat-resistant rubber layer 2 is determined according to JIS.
The A hardness is preferably 60 ° or less. The heat-resistant rubber layer 2
May be formed of foamed heat-resistant rubber.

As the raw material of the silicone rubber, various raw materials from liquid to solid are commercially available, and these can be heated and vulcanized to form the heat-resistant rubber layer 2. At that time, when the sheet-like raw material is used for the inner and outer layers, the production of a flexible telescopic tube becomes easy as described later. In addition, using a liquid or near liquid material, a suitable mold (outer mold)
It is also possible to inject the raw material by using.

The reinforcing layer 3 comprises a spirally arranged metal wire group 3a and a spirally arranged metal wire group 3b in the opposite direction. In the example shown in FIG. 1, each of the metal wire groups 3a and 3b is composed of a large number of metal wires arranged substantially in parallel and at substantially equal intervals, and the gap between each metal wire, and the metal wire groups 3a and 3b. Are filled with heat-resistant rubber. By filling the heat-resistant rubber between the metal wires as described above, it is possible to effectively prevent abrasion or the like due to sliding between the wires when the tube is deformed or when an internal pressure is applied.

As the metal wire, stainless steel, steel wire,
Or these stranded wires are preferable, and the diameter is 0.1-2.
A material of about 0 mm is selected according to the material, the outer diameter of the pipe, and the like. In addition, the interval between the metal wires only needs to have a gap enough for the rubber material to enter, and it is preferable to provide an interval equal to or larger than the diameter of the metal wire.

When the reinforcing angle θ with respect to the axis line in the helical arrangement is closer to the so-called stationary angle (about 55 ° C.), the pressure resistance increases, but in order to reduce the amount of retreat (retraction) during eccentricity. It is preferable that the angle is slightly larger than the static angle.

The heat-resistant rubber layer 2 and the metal wire or the bellows-like metal tube 1 may be adhered or non-adhered. However, even if they are not adhered, separation from the metal wire or the bellows-like metal tube 1 hardly occurs. . For example, when bonding with silicone rubber, the metal wire and the bellows-shaped metal tube 1 may be subjected to a primer treatment and then vulcanized and bonded.

The flexible telescopic tube of the present invention is manufactured as follows. As shown in FIG. 2, first, a sheet-shaped raw rubber (for example, Toray Silicon SH52U, etc.) is wound around the outer periphery of the bellows-like metal tube 1, and if necessary, the outer periphery is tightened with a tape or the like. Layer 2
a is formed on the outer periphery of the bellows-like metal tube 1. At that time, when the raw rubber is heated, the filling of the concave portion 1a becomes easy. Next, a metal wire cylindrical body 3A having substantially the same inner diameter as the outer diameter of the inner layer 2a and having the metal wire groups 3a arranged in a helical manner is applied to the inner layer 2a while applying a rotational force from both ends in the direction of expanding the diameter. After extrapolation to the inner layer 2a, the metal wire group 3a can be embedded in the inner layer 2a by sequentially applying a rotational force in a direction of reducing the diameter from one end to the other end. If necessary, after winding a thin sheet of raw rubber, the metal wire group 3b
The outer layer 2b of the heat-resistant rubber layer 2 is formed by winding a metal wire cylindrical body 3B arranged in a spiral shape and then further winding a sheet-shaped raw rubber. afterwards,
By performing sufficient tightening from the outer periphery using a cloth tape or the like, the raw rubber can be filled between the metal wires. This is put in an outer mold that can be divided as necessary, and steam vulcanization or air vulcanization at a high temperature is performed. When a silicone rubber is used, the temperature is relatively low (for example, 140 to 16).
0 ° C.) and relatively high temperatures (e.g.
By performing the secondary vulcanization at 60 ° C.), various physical properties can be improved.

As shown in FIG. 2, the metal wire cylinders 3A and 3B are formed by spirally winding the metal wire groups 3a and 3b around the surface of a column or the like to form a cylindrical shape, and then maintaining the arrangement. (For example, resistance welding)
What has been used can be suitably used. By rotating the annular holding member 4 in the opposite direction, the metal wire cylindrical bodies 3A, 3
B can be easily expanded or reduced in diameter.

[Other Embodiments of Flexible Telescopic Tube] (1) In the above-described embodiment, an example is shown in which the metal wire group 3a and the metal wire group 3b are arranged at two-layer intervals.
The number of layers may be further increased. In this case, it is preferable to balance the reinforcement of the metal wire group arranged in a spiral shape in the opposite direction, and it is preferable to use an even number of layers. Further, the metal wire group 3a and the metal wire group 3b may be arranged without any gap.

(2) In the above-described embodiment, an example is shown in which the reinforcing layer 3 is formed using the metal wire cylinders 3A and 3B prepared in advance, but the inner layer 2a of the heat-resistant rubber layer 2 is formed in a bellows shape. After being formed on the outer periphery of the metal tube 1, its inner layer 2a
The inner layer 2a of the bellows-shaped metal tube 1 is wound around a metal wire while reciprocating in the axial direction, thereby forming a reinforcing layer composed of a group of metal wires arranged without being spirally woven in opposite directions. May be. In that case, one or a few metal wires are used. That is, the metal wire group referred to in the present invention refers to a set of metal wire portions arranged in a spiral,
It includes the case where it is formed of one metal wire.

(3) In the above embodiment, the metal wire group 3
Although the example in which both a and the metal wire group 3b are buried in the heat-resistant rubber layer 2 has been described, a part of the metal wire arranged on the outermost side may be partially exposed. Therefore, the step of winding the sheet-like raw rubber as the outer layer of the heat-resistant rubber layer can be omitted.

[Flexible expansion joint] A flexible expansion joint according to the present invention is a flexible expansion joint comprising a flexible expansion section and connecting sections of mating pipes provided at both ends thereof, wherein the flexible expansion section has the above-mentioned configuration. It is characterized by being formed of such a flexible telescopic tube.

In this embodiment, as shown in FIG. 3, the connecting portion is formed by a flange member 10 having a bolt hole 10b for connection, a flat ring-shaped gasket member 11, and a split ring 12 in two. The example formed is shown.

The end 1c of the bellows-shaped metal tube 1 of the flexible telescopic tube is flattened at its end face and joined to the gasket member 11 by welding or bonding. At that time, the end 1
What c was flared beforehand may be used. In the annular concave portion 1a at the end of the bellows-shaped metal tube 1, the vicinity of the end of the metal wire is folded and locked by a split ring 12, which is a locking member that can be annularly arranged. Although the split ring 12 is joined to the flange member 10 so as not to come off, the inner circumference of the flange member 10 at the joint end side may be cut out so that the split ring 12 can be fitted and held.

Note that the cylindrical annular holding member 4 is disposed near the inner periphery of the flange member 10, and the flange member 1
The stress concentration at the boundary between 0 and the flexible telescopic tube is reduced.
For the flange member 10 and the split ring 12, various metals such as steel and stainless steel can be used. For the gasket member 11, for example, a heat-resistant resin such as Teflon or a composite of such a metal can be used.

The performance of the flexible expansion joint of the present invention as described above was evaluated by comparing a conventional SUS bellows tube with a reinforcing layer (see FIG. 5A) in which a SUS blade was woven in a cylindrical shape on the outer periphery. Table 1 below shows a comparison with the flexible expansion joint.

[0039]

[Table 1] * 1) The amount of retraction refers to the amount of reduction when the distance between the mounting surfaces is reduced by the amount that the shaft length does not change when the flexible expansion joint is eccentric. If this retreat is large, the pipe will be pulled.

The flexible expansion joint of the present invention is manufactured, for example, as follows. When the flexible telescopic tube is manufactured as described above, the end face of the end portion 1c of the bellows-shaped metal tube 1 is flattened in advance, and the metal wire groups 3a and 3b are left slightly longer than the end portion 1c. Then, the heat-resistant rubber layer 2 is formed leaving the annular concave portion 1a at the end of the bellows-like metal tube 1. Next, the vicinity of the end of the metal wire is folded into the annular concave portion 1 a by an appropriate jig or the like or the split ring 12, and the metal wire is locked by the split ring 12. Thereafter, the flange member 10 inserted from the other side is joined to the split ring 12, and the gasket member 11 is joined to the end 1 c of the bellows-like metal tube 1 by welding or bonding. The other connecting portion is manufactured in the same manner, but the flange member 10 may be inserted in advance through a flexible telescopic tube. Thereafter, if necessary, using an appropriate outer mold, heat vulcanization may be performed in the same manner as in the case of the flexible telescopic tube.

[Other Embodiments of Flexible Expansion Joint] (1) In the above-mentioned embodiment, the vicinity of the end of the metal wire rod is folded into the annular concave portion at the end of the bellows-shaped metal pipe so that the arrangement can be arranged in a ring. Although the example in which it is locked by the stop member is shown, as shown in FIG. 4, a metal wire may be joined to the connection portion by welding or the like. In this case, the end of the metal wire group 3a on the inner peripheral side is butted against the split ring 12 and welded, and the end of the metal wire group 3b on the outer peripheral side is connected to the inner peripheral portion 10a of the flange member 10.
Welding or the like. At that time, the flange member 10 has the function as the annular holding member 4, and the annular holding member 4 of the metal wire group 3b can be omitted.

(2) In the above-described embodiment, the example of the flexible expansion joint of the flange type in which the connecting portion of the mating pipe is used has been described.
As the connection part of the mating pipe, any of known connection parts such as a bevel type, a mechanical type, a victor type, a nipple type, and a female screw type can be used.

In this case, it is preferable that the metal wire groups 3a and 3b of the flexible telescopic tube are firmly held at the connecting portions by joining or locking at any connecting portions. In addition, it is preferable that the gasket member 11 be joined to the end of the bellows-like metal tube 1 or the like for a connection portion using the gasket member 11.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing an example of a flexible telescopic tube of the present invention.

FIG. 2 is an assembly view showing an example of a flexible telescopic tube according to the present invention.

FIG. 3 is a sectional view of a main part showing an example of a flexible expansion joint of the present invention.

FIG. 4 is a sectional view of a main part showing another example of the flexible expansion joint of the present invention.

FIG. 5 is an enlarged view of a main part showing a conventional flexible expansion joint.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 bellows-like metal pipe 1 a recess 2 heat-resistant rubber layer 3 reinforcing layer 3 a, 3 b metal wire group 12 split ring (locking member)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16L 27/10 F16L 27/10 A 33/00 33/26 33/28 33/00 B 33/26 F term (Ref.) EA10

Claims (5)

[Claims] 1. A reinforcement comprising a bellows-like metal tube, a heat-resistant rubber layer covering the outer periphery thereof, and a metal wire group embedded in the heat-resistant rubber layer and arranged in a reverse spiral without being woven. A flexible telescopic tube comprising a layer. 2. A flexible telescopic tube according to claim 1, wherein said heat-resistant rubber layer is formed of silicone rubber. 3. An inner peripheral portion of the heat-resistant rubber layer is filled in a concave portion on an outer peripheral surface of the bellows-like metal tube.
Or the flexible telescopic tube according to 2. 4. A flexible telescopic joint comprising a flexible telescopic part and connecting parts of mating pipes provided at both ends thereof, wherein the flexible telescopic part is the flexible telescopic pipe according to claim 1. A flexible expansion joint characterized in that it is formed with a flexible expansion joint. 5. A flexible telescopic joint comprising a flexible telescopic part and connecting parts of mating pipes provided at both ends thereof, wherein the flexible telescopic part is a flexible telescopic pipe according to claim 1. And at the same time, the vicinity of the end of the metal wire is folded into an annular concave portion at the end of the bellows-shaped metal tube and locked by a locking member that can be annularly arranged. Toe expansion joint.