JPH08300504A - Fireproof double layer tube wherein inner tube and outer tube are fixed to each other and method for fixing outer tube of fireproof double layer tube to its inner tube - Google Patents

Abstract

PURPOSE: To provide a method for fixing an outer tube to an inner tube wherein a fireproof double layer tube is provided by fixing the outer tube to the inner tube without making any member stand in a gap between the inner tube and the outer tube of the fireproof double layer tube; and though the inner tuber of the fireproof double layer tube is fixed to the outer tube so as not to be easily separated therefrom, the fixed state can be easily released. CONSTITUTION: A stretched film 13 is wound around so that the whole from both end parts of an incombustible outer tube 11 extending over a synthetic resin-made inner tube 12 exposed from the end part can be surrounded. In that case, the stretched film 13 having a film width is wound on by pilling flatly. Further, it may be wound spirally with the stretched film 13 of a narrow width. In that case, even though the whole of the wound part 13 is not hidden with the stretched film 13, a part of the incombustible outer tube 11 and the synthetic resin-made inner tube 12 may be exposed by winding reticulately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire-resistant two-layer pipe in which an inner pipe made of synthetic resin is inserted and combined inside a non-combustible outer pipe, and the outer pipe and the inner pipe are not easily separated from each other. TECHNICAL FIELD The present invention relates to a fixing method for preventing separation of an outer pipe and an inner pipe of a layer pipe and a fire-resistant double-layer pipe.

[0002]

2. Description of the Related Art Conventionally, synthetic resin pipes such as vinyl chloride have excellent characteristics such as chemical resistance, corrosion resistance, inner surface smoothness and workability as compared with metal pipes, etc. Widely used for pipes and ventilation pipes. However, this synthetic resin pipe such as vinyl chloride has poor fire resistance and is easily burned off in the event of a fire, and has the drawback that it spreads fire and produces toxic gas. In particular, in an apartment house such as an apartment, there is a risk that the fire may be transferred to another section through the synthetic resin pipe, which has been a serious disaster prevention problem.

Therefore, in order to cover such a drawback, a fire-resistant double-layer pipe in which the outer peripheral surface of a synthetic resin pipe is coated with a non-combustible material, for example, a vinyl chloride pipe or an asbestos vinyl double-layer pipe coated with fiber reinforced mortar is used. It has become widely used in general. In such composite pipes (two-layer pipes), the degree of thermal expansion or contraction between the inner and outer pipes is reduced due to the shrinkage of the outer pipe due to drying or the thermal expansion of the synthetic resin pipe due to the passage of hot water in the inner pipe. One of the problems has been that stress is generated in the inner and outer pipes due to the difference, which causes cracks in the inner and outer pipes.

As a countermeasure against this, a protrusion is provided on the outer side of the inner pipe to absorb these stresses to form a gap between the inner pipe and the outer pipe, thereby preventing the inner and outer pipes from cracking. (Japanese Patent Publication No. 50-7770), or a method in which a layered body such as expanded polystyrene is interposed between the inner and outer tubes as an alternative to the protrusion (Japanese Patent Laid-Open No. 51-112).
No. 813) has been proposed. These inclusions also have a role of fixing the outer tube and the inner tube.

On the other hand, as a method in which an intermediate member is not interposed between the two pipes, a nonflammable outer pipe is formed into an elliptical shape, and the inner pipe made of synthetic resin is held on the short diameter side while the inner pipe is made on the long diameter side. Those that form a gap with (Japanese Patent Publication No. 57-178741)
No.) has been proposed, the easiest way to obtain the gap between the outer tube and the inner tube is to combine it with an outer tube having an inner diameter larger than the outer diameter of the inner tube. By the way, when using a fireproof double-layer pipe without such an intermediate member, the inner pipe may fall out during handling, for example, during transportation. It is necessary to fix them so as not to separate them, and it is desirable that these fixing means can be easily released at the site during construction.

Therefore, as a method of preventing the inner pipe from coming off, a rubber band or the like is attached to the outer peripheral surface of the synthetic resin inner pipe exposed from the outer pipe end portion near the outer pipe end portion, or incombustible. From the end of the flexible outer tube to the inner tube made of synthetic resin exposed at the end, the whole is surrounded by a heat-shrinkable film, then heated by applying hot air, etc. A method (Japanese Patent Publication No. 62-2194) of fixing the outer tube and the inner tube by a tightening force due to the shrinkage of the shrinkable film has been performed.

[0007]

However, in the method of fixing the inner tube with the rubber band, the inner tube is likely to come off, and the heat shrink film does not shrink unless it is heated by applying hot air. After fixing the inner tube and the inner tube, the film cannot be further shrunk in a storage state at normal temperature. Therefore, after fixing, if the outer tube contracts slightly due to drying, etc., or if the inner tube contracts slightly due to a drop in temperature, etc., the tightening force of the heat-shrinkable film is released. May leave.

Therefore, a first object of the present invention is to provide a fire-resistant double-layer pipe in which the outer pipe and the inner pipe are fixed without providing any intervening member in the gap between the inner pipe and the outer pipe of the fire-resistant double-layer pipe. To provide. A second object of the present invention is to provide a method for fixing an outer tube and an inner tube, in which the inner tube and the outer tube of the fire-resistant double-layer tube are fixed so as not to be easily separated, and the fixed state can be easily released. To provide.

[0009]

According to a first aspect of the present invention, a nonflammable outer tube is inserted into the outer tube and has an outer diameter slightly longer than the outer tube and smaller than the inner diameter of the outer tube. With the inner tube made of synthetic resin, the end of the inner tube made of synthetic resin protruding from one or both ends of the non-combustible outer tube and the end of the non-combustible outer tube, stretched The first object is achieved by constructing a fire-resistant double-layer tube from a film having a self-expanding adhesive force, which is wrapped around and surrounded by one or more layers and closely fixed.

According to a second aspect of the present invention, in a fire-resistant double-layer pipe having a non-combustible outer pipe and a synthetic resin inner pipe slightly longer than the outer pipe with a predetermined gap, one of the non-combustible outer pipes is provided. Alternatively, the end of the synthetic resin inner tube protruding from both ends and the end of the non-combustible outer tube are wrapped around the film having a self-expanding adhesive force to further surround and closely adhere. The second object is achieved by fixing the above. According to a third aspect of the present invention, in a fire-resistant double-layer pipe having a non-combustible outer pipe and a synthetic resin inner pipe slightly longer than the outer pipe with a predetermined gap, one or both of the non-combustible outer pipe and The end of the inner tube made of synthetic resin and the end of the nonflammable outer tube protruding from the end are spirally wound and fixed in a stretched state with a film having self-expanding sticking force. Achieve the purpose of 2.

According to a fourth aspect of the present invention, in a fire-resistant double-layer pipe having a non-combustible outer pipe and a synthetic resin inner pipe slightly longer than the outer pipe with a predetermined gap, one of the non-combustible outer pipes is provided. Alternatively, a film having a self-expanding adhesive force is stretched around the outer circumference of the end of the synthetic resin inner tube protruding from both ends, and the film is wound thicker than the above gap, and the non-combustible outer tube The second object is achieved by making the stopper contact with the end portion to prevent the inner tube made of synthetic resin from coming off. According to a fifth aspect of the present invention, in the fourth aspect of the present invention, a cord-like body is wound around the outer periphery of the end of the synthetic resin inner tube protruding from one or both ends of the noncombustible outer tube. The second object is achieved by winding a film having a self-expanding adhesive force on the outer surface of the film while the film is wound thicker than the gap.

[0012]

According to the first aspect of the present invention, there is provided a fireproof double-layered tube having an inner tube and an outer tube fixed to each other. One end of the nonflammable outer tube and one end of the synthetic resin inner tube protruding from the nonflammable outer tube. Alternatively, a film having a self-expanding adhesive force is stretched around both ends and is wrapped around one or more layers. Therefore, the non-combustible outer tube and the synthetic resin inner tube are fixed by the shrinkage force and the adhesive force of the film so as not to be easily separated.

According to a second aspect of the present invention, there is provided a method for fixing an outer tube and an inner tube of a refractory double-layer tube, wherein an end portion of a synthetic resin inner tube protruding from one or both end portions of a non-combustible outer tube. The end portion of the non-flammable outer tube is wrapped with and wrapped around one more layer in the state where the film having the self-stretching adhesive force is stretched to be tightly fixed. In the method for fixing the outer pipe and the inner pipe of the fire-resistant double-layer pipe according to claim 3, the end portion of the inner pipe made of synthetic resin protruding from one or both end portions of the non-combustible outer pipe and the non-combustible inner pipe. The end portion of the outer tube is spirally wound and fixed in a state where a film having a self-expanding adhesive force is stretched.

In the method of fixing the outer tube and the inner tube of the fire-resistant double-layer tube according to the fourth aspect, the end portion of the synthetic resin inner tube protruding from one or both ends of the non-combustible outer tube A film having a self-expanding adhesive force is stretched around the outer periphery and is wound thicker than the gap. The contact of this with the end of the non-combustible outer tube restricts the movement of the synthetic resin inner tube, and functions to prevent separation. In the method for fixing the outer pipe and the inner pipe of the fire-resistant double-layer pipe according to claim 5, a string is attached to the outer periphery of the end of the synthetic resin inner pipe protruding from one or both ends of the non-combustible outer pipe. Wrap the shape. Then, wrap the outer surface of the film with self-expanding adhesive force in a stretched state, and the end of the non-combustible outer tube comes into contact with it to limit the movement of the synthetic resin inner tube and prevent it from coming off. Fulfill the function of.

[0015]

Embodiments of the method for fixing the outer pipe and the inner pipe of the fireproof double-layer pipe of the present invention will be described in detail below with reference to FIGS. 1 to 4. FIG. 1 is a diagram showing an appearance of a refractory two-layer pipe 10 in which an inner pipe and an outer pipe are fixed to each other according to an embodiment of the present invention. In this figure, 11 is an incombustible outer tube, 12 is an inner tube made of synthetic resin,
13 is a film (stretch film) having a self-expanding adhesive force. Further, since the outer diameter of the synthetic resin inner tube 12 is slightly smaller than the inner diameter of the nonflammable outer tube 11, a gap 14 is formed between them. Due to the gap 14, for example, hot water or the like flows in the synthetic resin inner tube 12 so that even if the synthetic resin inner tube 12 thermally expands, the force does not reach the nonflammable outer tube 11. ing.
That is, the gap 14 plays a role of buffering the expansion and contraction of the nonflammable outer tube 11 and the synthetic resin inner tube 12. On the other hand, because of the gap 14, the inner tube 12 made of synthetic resin may fall off from the nonflammable outer tube 11 when the fire-resistant double-layer tube is transported.

The inner tube 12 made of synthetic resin is an incombustible outer tube 1.
Since it is slightly longer than 1, both ends 12a and 12b project from the nonflammable outer tube 11. The stretch film 13 having a self-stretching adhesive force has a width of 1 mm to 500 mm, usually 20 mm to 200 mm, and a thickness of 5 μ to 500 μm.
μ, usually 15 μ to 100 μ. In addition, the stretch ratio when the stretch film 13 is wound is 0.5.
% To 500%, usually 20% to 100%.
As the material of the stretch film 13, linear low-density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyester, etc. are appropriately used, and the adhesive is an adhesive such as vinyl acetate or polyolefin. In some cases, the agent may be applied to a film or mixed with an ethylene-vinyl acetate copolymer or the like to form a film having two or more layers with a film made of another material. This adhesive may be applied not only on one side of the film but also on both sides, and in the case of two or more layers with a film of another material, it may be a film layer in which a double-sided adhesive is mixed.

The stretch film 13 is usually wound around a paper tube having the same length as the film width, and the winding length is 300 m to 2000 m, but the winding length is also determined by the weight and the like. In addition, it may be used after being cut out into a predetermined size from a sheet-shaped one. The stretch film 13 is usually colorless and transparent, but it may be colored.

Next, how to wind the stretch film 13 will be described. Stretch film 13
As shown in FIG. 1, both ends of a nonflammable outer tube 11 and inner tubes 12a and 12b made of synthetic resin exposed from the ends are wound so as to be entirely enclosed. In this case, the stretch film 13 having a film width is wound in a flat layer. Moreover, as shown in FIG. 2, the non-combustible outer tube 11 may be wound around both ends (12a) of only one of the synthetic resin inner tubes 12 exposed from the both ends. In the example shown in FIG. 2, only one end is wound, so it is desirable to wind a plurality of times, for example, 2 to 5 times to increase the strength.

Since the stretch film 13 is wound in a stretched state, the non-combustible outer tube 11 contracts due to drying or the like, and the inner tube 12 made of synthetic resin contracts due to a decrease in temperature. In that case, the tightening force of the stretch film 13 is
It is held following by the contracting force of. Therefore, after fixing, the nonflammable outer tube 11 and the synthetic resin inner tube 12 are not easily separated. Therefore, even if the product is transported to cold regions, high temperature regions, and dry regions, the fixing does not loosen.

Further, this stretch film 13 is
Since it has a self-stretching adhesive force, it does not peel off naturally after being adhered to each other and fixed. In addition, the stretched film 13 that has been wound can be easily unwound and removed from the end of the film, which is the end of winding, by an external force, such as by hand, during construction. Also, since it can be cut off with a cutter knife or the like, the stretch film 13
The fixation by can be released by a simple work on site.

Further, as shown in FIG. 3, a narrow stretch film 13 may be wound in a spiral shape. In this case, even if the entire winding portion is not covered with the stretch film 13, the winding portion may be wound in a mesh shape and a part of the nonflammable outer tube 11 and the synthetic resin inner tube 12 may be exposed. Further, as shown in FIG. 4, the protrusion 12a of the inner tube 12 made of synthetic resin
In contact with the non-combustible outer tube 11, the stretch film 1
It is also possible to wind 3 into a thickness equal to or larger than the gap 14 and act as a stopper to prevent the inner tube 12 made of synthetic resin from coming off. In this embodiment, the above effect can be achieved by a simple operation of winding the stretch film 13 around the outer periphery of the protruding portion 12a of the cylindrical inner tube 12 made of synthetic resin. At this time, the stretch film 13 may have a narrow width. In this embodiment, the inner tube 1 made of synthetic resin is used.
Although it is wound around only the two protruding portions 12a, it is possible to achieve the above-described effect better when wound around both the protruding portions 12a and 12b of the synthetic resin inner tube 12.

As a modification of this embodiment, there is a method in which a string-like body is attached to the entire outer surface of the projecting portion 12a of the synthetic resin inner tube 12 in advance, and the outside thereof is surrounded by the stretch film 13. . In this example, the stopper effect of the stretch film 13 is increased, and the inner tube 12 made of synthetic resin is increased.
Becomes more difficult to detach. Alternatively, the stopper effect can be increased by inserting and attaching a string-like body between the winding layers of the stretch film 13.

[0023]

According to the fire-resistant double-layer pipe in which the inner pipe and the outer pipe are fixed to each other, the end portion of the noncombustible outer pipe and one or both ends of the synthetic resin inner pipe are self-expanding and sticking together. Since the film with the film is wrapped and wrapped more than once in the stretched state, it is fixed so that the non-combustible outer tube and the synthetic resin inner tube are not easily separated by the self-shrinking force and adhesive force of the film. ing. Since this film is stretchable to some extent, it can cope with the expansion and contraction of the refractory double-layered pipe due to changes in the temperature and the like, and the fixation does not loosen. Furthermore, since this film can be easily peeled off, no extra work is required at the construction site.

In the method for fixing the outer tube and the inner tube of the fireproof double-layer tube according to the second aspect of the present invention, there is no need to provide any intervening member in the gap between the noncombustible outer tube and the synthetic resin inner tube. Can be firmly fixed. Since this film is stretchable to some extent, it can cope with the expansion and contraction of the refractory double-layered pipe due to changes in the temperature and the like, and the fixation does not loosen. Furthermore, since this film can be easily peeled off, no extra work is required at the construction site. Claim 3
In the method of fixing the outer tube and the inner tube of the fire-resistant double-layered pipe described above, the two should be firmly fixed without providing any intervening member in the gap between the noncombustible outer tube and the inner tube made of synthetic resin. You can Since this film is stretchable to some extent, it can cope with the expansion and contraction of the refractory double-layered pipe due to changes in the temperature and the like, and the fixation does not loosen. Furthermore, since this film can be easily peeled off, no extra work is required at the construction site.

In the method for fixing the outer tube and the inner tube of the fire-resistant double-layer tube according to the fourth aspect, the inner tube made of a synthetic resin is internally stretched with a film having a self-expanding adhesive force on the outer periphery of the end section. It is possible to reliably prevent the inner tube made of synthetic resin from coming off by a simple work of winding the tube thicker than the gap between the tube and the outer tube. This film can be easily peeled off,
No extra effort is required at the construction site. In the method for fixing the outer pipe and the inner pipe of the fire-resistant double-layer pipe according to claim 5, a film having a self-expanding adhesive force is wound on the outer surface of a string-like body wrapped around the outer periphery of the end of the inner pipe made of synthetic resin. It is possible to reliably prevent the inner tube made of synthetic resin from coming off by a simple work of winding in a stretched state. Since this film can be easily peeled off, no extra work is required at the construction site.

[Brief description of drawings]

FIG. 1 is a diagram showing the appearance of a fire-resistant double-layer pipe in which an inner pipe and an outer pipe are fixed according to an embodiment of the present invention.

FIG. 2 is a view showing the appearance of a fire-resistant double-layer pipe in which one ends of an inner pipe and an outer pipe are fixed according to an embodiment of the present invention.

FIG. 3 is a view showing a state in which a film according to an embodiment of the present invention is spirally wound and an inner tube is fixed.

FIG. 4 is a view showing a state in which a film according to an embodiment of the present invention is wound around an end portion of an inner pipe to prevent the inner pipe from coming off.

[Explanation of symbols]

10 Fire-Resistant Two-Layered Pipe 11 Nonflammable Outer Pipe 12 Synthetic Resin Inner Pipe 12a, 12b Protruding Part (End) of Synthetic Resin Inner Pipe 13 Stretch Film (Self-Expanding Adhesive Film) 14 Gap

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technology display area // B29L 23:00

Claims (5)

[Claims] 1. A non-combustible outer tube, an inner tube made of synthetic resin, which is inserted into the outer tube and has an outer diameter slightly longer than the outer tube and smaller than the inner diameter of the outer tube, and a non-combustible outer tube. A self-fixing method in which the end of an inner tube made of synthetic resin and the end of an incombustible outer tube projecting from one or both ends of the tube are wrapped in a stretched state to surround and closely adhere to each other. A fire-resistant double-layer pipe having an inner pipe and an outer pipe fixed to each other, which is made of a film having a stretchable adhesive force. 2. A fire-resistant double-layer pipe comprising a nonflammable outer tube and a synthetic resin inner tube slightly longer than the outer tube with a predetermined gap, wherein one or both ends of the nonflammable outer tube are provided. Characterized by fixing the protruding end of the synthetic resin inner tube and the end of the non-combustible outer tube with a film having a self-expanding adhesive force by winding it more than one degree in a stretched state and closely surrounding it. The method of fixing the outer pipe and the inner pipe of the fireproof double-layer pipe. 3. A non-combustible outer tube and a synthetic resin inner tube, which are slightly longer than the outer tube, having a predetermined gap, wherein a non-combustible outer tube is provided from one or both ends of the outer tube. A fireproof two characterized in that the end of the protruding inner tube made of synthetic resin and the end of the nonflammable outer tube are spirally wound and fixed in a stretched state of a film having a self-expanding adhesive force. Method of fixing outer pipe and inner pipe of layered pipe. 4. A fireproof two-layer pipe comprising a nonflammable outer tube and a synthetic resin inner tube slightly longer than the outer tube with a predetermined gap, wherein one or both end portions of the nonflammable outer tube are provided. Wrap the film having self-expanding adhesive force around the outer periphery of the protruding inner tube made of synthetic resin in a state in which it is wound thicker than the above gap, and bring this into contact with the end of the non-combustible outer tube. A method for fixing an outer pipe and an inner pipe of a fire-resistant double-layer pipe, characterized by using a stopper for preventing the inner pipe made of synthetic resin from coming off. 5. A cord-like body is wound around the outer periphery of the end of the synthetic resin inner tube protruding from one or both ends of the nonflammable outer tube, and the outer surface of the inner tube further has a self-expanding adhesive force. The method for fixing an outer pipe and an inner pipe of a fire-resistant double-layer pipe according to claim 4, wherein the film is wound thicker than the gap in a stretched state.