JP2001037045A - Fire-proof treatment element for outlet box and fire- proof outlet box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire-proof element which can surely exhibit its fire-proof function, without reducing the inner volume of an outlet box. SOLUTION: A fire-proof element 30 comprises a cylinder 32, which has an attaching part 38 to an outlet box 14 on its one end side, a thermally foamimg heat-resistant material 34 inserted into the cylinder 32 and a shape- memory alloy spring 36, which is provided in a compressed state between the thermally foamimg heat-resistant material 34 and a spring stop part 40 on the other end side of the cylinder 32. If the temperature of the shape-memory alloy spring 36 exceeds a certain value due to the heat of fire, the spring extends and pushes the thermally foamimg heat-resistant material 34 out of the cylinder 32 into the outlet box 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire prevention member for providing a fire prevention function to an outlet box used for indoor wiring, and a fire prevention type outlet box using the same.

[0002]

2. Description of the Related Art A general use state of an outlet box is shown in FIG. In the figure, 10 is a column (light steel frame) for partitioning a building, 12 and 12 are fire-resistant boards attached to both sides of the column 10, 14 is an outlet box attached to the column 10, and 16 is fire-resistant boards 12, 12 The conduit piped in the space between, 18 is an electric wire inserted into the conduit 16, 20 is an opening formed at a position corresponding to the outlet box 14 of the fireproof board 12, and 22 is an outlet box by means not shown. Fixed outlet, 24 is fireproof board
An outlet cover attached to the surface of 12 so as to close the opening 20.

[0003] Outlets and switches attached to indoor walls often use plastic parts. Therefore, if a fire occurs in a room, the outlet and the switch may be melted and deformed, causing a fire in the outlet box. If a fire enters the outlet box, the electric wire drawn into the outlet box may burn. When one portion of the electric wire burns, it spreads in the longitudinal direction, so that there is a risk of transmitting flame or smoke to the adjacent room. Also, if a fire enters the outlet box, there is a risk that fire or smoke may enter the interior space of the partition wall from the hole of the outlet box, and heat transfer may proceed to spread fire.

As an improvement on this point, the present inventor has previously proposed a fireproof type outlet box in which a heat-foamable refractory material is attached to the inner surface of the outlet box (Japanese Patent Application Laid-Open No. 7-298449). This is such that when the outlet box is heated by heat at the time of fire, the thermo-foamable refractory material foams and fills the outlet box to prevent the intrusion of flames and smoke. However, since the size of the outlet box is fixed, it has been found that there is a problem in that when the heat-expandable refractory material is attached to the inner surface, the inner volume is reduced, and wiring work becomes difficult.

It has also been proposed to attach a thermally foamable refractory material to the outer surface of the outlet box (the same publication). However, this structure expands into the outer space of the outlet box when the thermally foamable refractory material foams. Therefore, it was found that fire prevention performance as expected may not always be obtained.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a fire protection member for an outlet box capable of reliably exhibiting a fire prevention function without reducing the inner volume of the outlet box, and a fire protection type using the same. To provide an outlet box.

[0007]

According to the present invention, there is provided a fire prevention member for an outlet box, comprising: a tubular body having an attachment portion to an outlet box at one end side; a thermally foamable refractory material inserted into the tubular body; A shape memory alloy spring inserted in a state of being contracted in the axial direction between the thermally foamable refractory material and the spring stopper at the other end of the cylindrical body. The heat-expandable refractory material expands when the temperature reaches a certain temperature or more by heat, and is extruded from the cylindrical body.

In the fireproof type outlet box according to the present invention, the fireproofing member as described above is located outside the outlet box, and the mounting portion on one end side of the cylinder of the fireproofing member is connected to the electric wire of the outlet box. Is mounted in a hole that does not pass through.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show an embodiment of an outlet box fire prevention member according to the present invention. The fire prevention treatment member 30 includes a tubular body 32, a thermally foamable refractory material 34 and a shape memory alloy spring 36 inserted into the tubular body 32.

The cylindrical body 32 has a structure in which a portion 38 for attaching to the outlet box 14 is provided on the outer periphery of one end and a spring stopper 40 is provided on the other end. The shape memory alloy spring 36 is arranged between the spring stopper 40 and the thermally foamable refractory material 34 in a state of being contracted in the axial direction. A disc made of a heat-resistant material such as metal is provided between the shape memory alloy spring 36 and the heat-expandable refractory material 34 so that the repulsive force of the shape memory alloy spring 36 is uniformly applied to the end face of the heat-expandable refractory material 34. 42 is interposed.

The mounting portion 38 of the cylindrical body 32 includes a male screw portion 38a and a flange portion.
The spring stopper 40 is formed by an end wall of the cylindrical body 32. However, these may have other structures as described later.

The heat-expandable refractory material 34 expands by 3 to 50 times when heated by the heat of a fire, and expands 3 to 50 times, and retains the fire resistance in the expanded state. For example, a composition comprising a base resin such as butyl rubber, an expanding agent such as thermally expandable graphite, and a resin such as polycarbonate which leaves a residue such as a carbide after being heated is known. Commercial products include Danseal D (trade name) manufactured by Furukawa Techno Material Co., Ltd. The amount of the heat-expandable refractory material 34 is sufficient to fill the interior space of the outlet box when foamed.

The shape memory alloy spring 36 is heated by the heat of a fire, and when it reaches a certain temperature (for example, 70 ° C.) or more, it attempts to restore its memory shape (spring expanded shape) and exerts a large repulsive force. Since there is no restoring force, there is no force to push out the thermally foamable refractory material 34 even if it is housed in the cylindrical body 32 in a state where it is contracted in the axial direction as shown in FIG. Thermal foaming refractory
Numeral 34 is maintained at the position shown in the figure by frictional force with the inner surface of the cylindrical body 32 (it may be temporarily fixed to the cylindrical body 32 by bonding or other means).

A plurality of windows 44 are formed in a portion of the cylindrical body 32 in which the shape memory alloy spring 36 is housed. This is to make it easier for the heat of the fire to be transmitted to the shape memory alloy spring 36. The tubular body 32 is preferably formed of a metal having good thermal conductivity, for example, aluminum so that heat of a fire is easily transmitted to the shape memory alloy spring 36.

FIG. 3 shows a fireproof type outlet box in which the fireproofing member 30 configured as described above is attached to the outlet box 14. Outlet box
14 is formed with a large number of circular cuts 46 that are partially discontinuous in the circumferential direction, and a disk hole 48 in the cut 46 is lifted up with a screwdriver or the like to easily remove a hole for a wire. It can be formed. Circular cut 46
Are distributed on each side of the outlet box 14 so that the wires can be drawn in from any direction,
Only a few are actually used as through holes, and many are not used as through holes. The fire protection member 30 is attached by selecting a hole that does not pass through the wire. As shown in FIGS. 1 and 2, the outlet box 14 can be attached to the hole by inserting a male screw into the hole of the outlet box 14 and tightening the nut 50 from the inside.

When the fire prevention member 30 is attached to the outlet box 14 as shown in FIG. 3, when a fire occurs and the temperature of the fire prevention member 30 rises to a certain temperature or more, the shape memory alloy spring is used. 36 generates a large repulsive force in an attempt to restore (elongate) to the memory shape. For this reason, the heat-expandable refractory material 34 is pushed out of the tubular body 32 into the outlet box 14 as shown in FIG.

Thereafter, when the temperature further rises, the heat-expandable refractory material 34 expands and expands to fill the outlet box 14, thereby preventing the outlet box 14 from entering a flame or smoke. Therefore, the spread of the fire from the outlet box 14 can be prevented. Also, since the fire protection member 30 is attached to the outside of the outlet box 14,
The wiring operation can be performed without hindrance without reducing the inner volume of the outlet box 14.

Next, the trial production and test results will be described. Outer diameter 20m
m, an aluminum cylinder with a length of 100 mm, a shape memory alloy spring extending at 70 ° C, a 0.5 mm thick metal disk, an outer diameter of 18 mm,
A fire-resistant material having a length of 75 mm (Dan Seal D manufactured by Furukawa Techno Material Co., Ltd.) was inserted into the fire-resistant material. This fire prevention member was attached to the upper surface of the outlet box as shown in FIG. Attach the outlet box to the lightweight steel column and insert F into the outlet box.
Two cables were pulled in, and a 100 V, two-port outlet was attached. Placing a 12 mm thick gypsum board on both sides of the support,
An opening is formed at a position corresponding to the outlet box,
A plastic outlet cover was attached there. A fire resistance test was performed in this state. Test conditions are JIS
A1304 is 2 hours. After the test was completed, it was confirmed that the heat-foamable refractory foamed inside the outlet box and was sufficiently filled, and that the fire-retardant and smoke-proof properties were sufficient.

In the above embodiment, the mounting portion of the cylindrical body 32
38 comprises an external thread 38a and a flange 38b, and a spring stopper 40
Has been described as being constituted by the end wall of the cylindrical body 32, but these may be other forms. For example, as shown in FIGS.
The elastic locking piece 54 having a claw portion 54a hooked inside the edge of the fourteenth hole 52, and a flange-shaped stopper 56 abutting on the outside of the edge of the hole 52 may be used. Spring stop
40 can also be constituted by a claw piece or the like obtained by bending a part of the end of the cylindrical body 32 inward.

[0020]

As described above, when the fire-resistant treatment member of the present invention is used, the inner volume of the outlet box can be reduced because the heat-expandable refractory material is normally located outside the outlet box. In addition, wiring work can be easily performed, and when a fire occurs, the heat-foamable refractory material is extruded into the outlet box to expand and expand, so that the inside of the outlet box can be reliably fireproof. Therefore, the spread of the fire through the outlet box can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of an outlet box fire protection member according to the present invention.

FIG. 2 is a cross-sectional view of the fire prevention treatment member of FIG.

FIG. 3 is a perspective view showing one embodiment of a fireproof outlet box according to the present invention.

FIG. 4 is a cross-sectional view showing a state in which the fire-resistant treatment member of FIG.

FIG. 5 shows another example of the structure of the attachment portion of the tubular body to the outlet box in the fire prevention treatment member of the present invention.
(A) is a plan view, (b) is a front view, and (c) is a bottom view.

FIG. 6 is a sectional view showing a general use state of the outlet box.

[Explanation of symbols]

 14: Outlet box 18: Electric wire 22: Outlet 30: Fire protection material for outlet box 32: Cylindrical body 34: Thermal foaming refractory material 36: Shape memory alloy spring 38: Mounting part 40: Spring stop part 42: Disk 44: Window 46: Notch 48: Disc 50: Nut

Claims (2)

[Claims] 1. A cylindrical body (32) having an attachment portion (38) to an outlet box (14) on one end side, and the cylindrical body (32).
A heat-expandable refractory material (34) inserted in the inside, and an axially shrinkage between the heat-expandable refractory material (34) and the spring stopper (40) at the other end of the tubular body (32). And a shape memory alloy spring (36) interposed in a state where the heat is generated by a fire. A fire protection member for an outlet box, which is extruded from a body (32). 2. The fire prevention member (30) according to claim 1, which is located outside the outlet box (14), and a mounting portion (38) on one end side of a cylinder (32) of the fire prevention member (30). )
A fireproof outlet box, which is attached to a hole of the outlet box (14) through which a wire is not inserted.