JPH0547910Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a fire-resistant spiral tube.

[Conventional technology and its problems]

Conventionally, in order to protect cables wired indoors, on the ceiling, or on the side walls of buildings, from the spread of fire,
A spiral tube as shown in FIG. 5 is used. This spiral tube 10 is made by spirally winding a steel metal tape so that its longitudinal side edges overlap, and the upper and lower sides of the overlapping part are engaged with folded parts 1 and 2 in opposite directions. A cable accommodating hollow part 3 is formed.

The spiral tube 10 having such a structure has high strength against loads along the longitudinal direction because the metal tape is spirally wound while the folded portions 1 and 2 are engaged with each other. However, the engagement portion formed by the engagement of the folded portions 1 and 2 cannot maintain complete airtightness. Therefore, when exposed to high heat due to fire or the like, the metal tape expands and the gap between the engaged parts becomes even larger. As a result, when the high-temperature gas enters the cable accommodation hollow 3, the cable inside the pipe generates flammable decomposition gas due to the high temperature, and this flammable gas is easily released outside the pipe. However, there was a problem in that the cable could easily burn out.

The present invention was made in view of this point, and is strong against loads along the longitudinal direction, and
By sealing the engagement at high temperatures such as during a fire,
The present invention provides a fireproof spiral tube that can completely protect the cable.

[Means for solving problems]

In a helical tube formed by spirally winding a metal tape while engaging its longitudinal side edges to form a cable accommodation hollow part, the present invention provides a spiral tube in which only the side edges of the metal tape serving as the engaging part are wound. This is a helical tube with fireproof properties characterized by interposing a thermally foamable fireproofing material layer.

Here, the heat-foamable fireproof material used in the present invention is, for example, a flameproof material containing an expanding agent and a spherical or almost spherical filler described in JP-A No. 55-65284. Foaming composition or JP-A-Sho
A plastic material that is usually putty-like is used, such as a non-flammable foamable molding composition containing a catalyst of ethylene diammonium and phosphate as an expanding agent, as described in Japanese Patent No. 56-55434.
In addition, such a substance is manufactured by Bayer AG in West Germany.
A product called FOMOX is commercially available.

Further, the thermally foamable fireproof material layer is formed by applying the above composition directly to the portion of the metal tape that will become the engaging portion. Further, from the viewpoint of workability, etc., the above composition may be applied to the entire surface of one side of the metal tape including the engaging portion.

Moreover, as the material of the metal tape, steel, stainless steel, etc. can be used.

In addition, the shape of the engaging part of the metal tape is such that the upper and lower sides of the engaging part are reversed so that the engaged part does not shift or separate even when a force is applied in the longitudinal direction. It is preferable that the cross-sections are substantially U-shaped so that they engage with each other.

[Effect]

According to the spiral tube according to the present invention, the thermally foamable fireproof material layer is formed only on the side edge of the metal tape that becomes the engaging part, so if a fire breaks out, the spiral tube will be damaged by the high heat generated at that time. When heated, the heat-foamable refractory material layer expands and becomes airtight by filling the engaging portion of the metal tape without easily foaming and burning or flowing out. As a result, the cable accommodation hollow is hermetically sealed off from the outside.
The internal cables can be completely protected from hot gas. Furthermore, the adhesive strength of the engaging portion of the metal tape is increased, and the mechanical strength in the longitudinal direction can be increased.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1A, each of the front side and back side of the side edge along the longitudinal direction of the metal tape 11 made of steel has a thickness of 0.5 mm and a width of about 3 mm.
A thermally foamable refractory material layer 12 having the following composition of mm was formed. Next, these side edges were bent toward the surface on which the heat-foamable refractory material layer 12 was formed so as to have a substantially U-shaped cross section. Next, as shown in FIG. 1B, the folded part 1
3 and 14 so that the upper side edge and the lower side edge of the metal tape 11 are engaged with each other in a spiral manner, and as shown in FIGS.
A spiral tube 15 having the following was assembled. Next, a predetermined cable was accommodated in the cable accommodation hollow part 16.

After reacting a mixture consisting of 33 parts by weight of dicyandiamide, 33 parts of sutucarose, 33 parts of ammonium polyphosphate, and 9 parts of water at 120°C for 25 hours,
50 parts by weight of hollow aluminum silicate beads (5 to 300 μm in diameter) were added as a filler to obtain a heat-foamable fireproof material.

The spiral tube 15 configured in this manner has the heat-foamable fireproofing material layer 12 interposed in the engaged portion where the folded portions 13 and 14 engage, so that when exposed to high heat similar to that in the case of a fire, etc. , the thermally foamable fireproof material layer 1
2 foamed and filled the engagement portion of the metal tape 11 without burning or flowing out, making it airtight. As a result, the cable housing hollow portion 16 was hermetically sealed from the outside, and the housed cables could be completely protected from high temperature gas. Furthermore, it was confirmed that the adhesive strength of the engaging portion was increased, and the mechanical strength of the spiral tube 15 in the longitudinal direction was improved.

[Effect of idea]

As explained above, the fireproof spiral tube according to the present invention is strong against loads along the longitudinal direction, and has remarkable effects such as being able to completely protect the cable from high-temperature gas in the event of a fire. It is something that you have.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a method of assembling a helical tube according to an embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams showing a schematic structure of a helical tube according to the embodiment, and FIG. It is an explanatory view of a conventional spiral tube. 11... Metal tape, 12... Heat-foamable fireproof material layer, 13, 14... Folded portion, 15... Spiral tube,
16... Cable accommodation hollow part.

Claims (1)

[Scope of utility model registration request] In a helical tube formed by spirally winding a metal tape while engaging its longitudinal side edges to form a cable-accommodating hollow part, only the side edges of the metal tape constituting the engaging part are thermally foamable. A spiral pipe having fireproof properties characterized by having a fireproof material layer interposed therebetween.