TW201607583A - Sprinkler head - Google Patents

Abstract

The present invention addresses the problem of providing a sprinkler head that has strength, durability or thermal conductivity and has been made lighter. A sprinkler head, which is provided with a main body inside which a nozzle for passing fire-extinguishing water is formed, a valve for closing the outlet of the nozzle, and a heat-sensitive decomposing section secured to the main body for holding the valve on the outlet of the nozzle and in which the heat-sensitive decomposing section comprises a low melting point alloy that melts due to the heat of a fire. In the sprinkler head, a material comprising carbon nanotubes is used for a constituent part of the heat-sensitive decomposing section. As a result, it is possible to configure a part that is lighter than prior metal parts and for which strength and thermal conductivity performance have been improved over prior resins.

Description

Sprinkler head

The present invention relates to a sprinkler head for fire fighting.

The sprinkler head is placed on the ceiling or wall of the building. The sprinkler head has a nozzle that can be connected to a pipe laid in the ceiling or inside the wall on one end side, and a thermal decomposition part is provided on the other end side. In normal times, the thermal decomposition portion supports the valve that locks the nozzle. A deflector is provided on the extension of the discharge direction of the nozzle, and the baffle plate scatters the fire extinguishing liquid discharged from the nozzle.

Such a well-known sprinkler head, when a fire occurs, first decomposes the thermal decomposition part due to the heat of the fire. The valve supported by the thermal decomposition unit loses its supporting force, receives the water pressure in the pipe, and is detached from the valve seat, and is detached from the outside of the body. The water in the piping is discharged from the opened nozzle, and the discharged water collides with the baffle and is dispersed to the outside to extinguish the fire. An example of a conventional sprinkler head is described in Patent Document 1.

The sprinkler head is mainly made of a metal material because it is required to be durable for several decades, or heat resistance in a fire, heat that absorbs fire, and heat transfer to the thermal decomposition portion.

On the other hand, in recent years, the labor-saving and short-term housing period of the construction work in the construction industry has continued to progress, and the sprinkler head is also required to reduce the burden on the operator, or the transportation cost and construction cost, by means of small size and light weight. The cut.

As a means for reducing the weight of the sprinkler head, a resin component is considered. However, the use of the resin material has problems in strength, durability, heat resistance, thermal conductivity, and the like, and cannot be put into practical use.

Patent Document 1: Japanese Patent Laid-Open No. Hei 7-284545

In view of the above problems, in the present invention, an object of the invention is to provide a sprinkler head having strength or durability, or thermal conductivity and being lightweight.

In order to achieve the above object, the present invention provides the following sprinkler heads. That is, a sprinkler head having a body having a nozzle through which the fire extinguishing water passes, a valve closing the outlet of the nozzle, and a sensible thermal decomposition portion that is locked to the body and holds the valve at the outlet of the nozzle, in the thermal decomposition portion A low-melting alloy that can be melted by the heat of fire is used, and a material including a carbon nanotube is used as a component of the thermal decomposition portion.

By using a material containing a carbon nanotube in the components of the sprinkler head, it is possible to obtain both durability and weight reduction, and an effect of improving heat conductivity. Examples of the effect of the carbon nanotubes include improvement of heat conduction performance, improvement of mechanical strength, and improvement of corrosion resistance. In a specific embodiment of the carbon nanotube, the coating film formed by coating the carbon nanotubes on the part is in direct contact with the low melting point alloy, and a coating film of the carbon nanotube is formed on the surface of the component. It is possible to improve the efficiency of absorbing heat during a fire, and to reduce the heat transfer loss between a plurality of parts.

Further, when the sprinkler head is placed in the building for a long period of time and corrosion is generated on the surface of the component of the thermosensitive decomposition portion, there is a fear that the components are fixed to each other and the decomposition operation of the thermosensitive decomposition portion is hindered. On the other hand, by carrying out the coating film of a carbon nanotube, it is possible to prevent the occurrence of corrosion products, and it is possible to maintain the operation reliability of the sprinkler head for a long period of time.

Further, since the load for closing the nozzle is always applied to the thermal decomposition portion, it is necessary to have mechanical strength capable of withstanding the load. Therefore, although conventionally used metal parts, the present invention is used by using the present invention. The resin material of the carbon nanotubes enables the strength and weight to be established (compatible). Further, in order to increase the strength, the resin material may contain a fine metal. When a low melting point alloy is used as the fine metal, the low melting point alloy is melted by the heat during molding to form a liquid, so that the fluidity of the material inside the mold is improved, and a part having good moldability and high dimensional accuracy can be produced.

On the other hand, when a material having good heat conductivity such as copper, brass or aluminum is mixed as the fine metal contained in the above resin material, the thermal conductivity is improved. Further, when the material having good thermal conductivity described above is buried in a metal plate and formed into a part, heat absorbed on the surface of the part can be conducted to the metal plate. Further, a part of the metal plate may be exposed on the surface of the part, and the exposed portion may be joined to the other parts by the low melting point alloy.

Alternatively, if stainless steel or glass fiber or the like of the fine small pieces is mixed as the metal contained in the above-mentioned resin material, the strength of the parts can be improved. In addition, stainless steel or glass fiber has a lower heat conductivity than iron or copper, and therefore has a heat insulating effect.

When a coating film having thermal conductivity is formed on the surface of the member having the above heat insulating effect, heat absorbed on the surface of the coating film can be hardly transmitted to the component. As a specific example of the coating film, a coating film of copper plating or a carbon nanotube can be used.

The parts of the coated film coated with the carbon nanotubes described above or the parts made of the resin material containing the carbon nanotubes are not only the constituents of the sprinkler head, but also the sprinklers attached to the sprinkler head. Head cover or ceiling plate, etc. As a specific example, the sprinkler head attached to the sprinkler head includes a retainer coupled to the sprinkler head, and covers and hides the sprinkler head. In the cover plate, since the cover plate and the fastener are joined by a low melting point alloy which can be melted by the heat of fire, the heat conductivity of the low melting point alloy can be improved by using a material containing a carbon nanotube in the cover plate. Or the weight of the cover.

According to the sprinkler head described above, by using a material including a carbon nanotube for a sprinkler head, it is possible to realize a sprinkler having strength, durability, or thermal conductivity and being lightweight.

S1, S2, S3‧‧‧ sprinkler head

1, 61, 101‧‧‧ ontology

2, 63, 103‧‧‧ valve

3, 50, 65, 105‧‧‧ Thermal decomposition

4‧‧‧Holding

5‧‧‧Flexible components

6‧‧‧ movable gap

7‧‧‧ Covering Department

32‧‧‧Connecting board

33, 51, 75, 112‧‧‧ low melting point alloy

34‧‧‧Leverage

35‧‧‧ pillar

52, 110‧‧‧ cylinder

53‧‧‧ Cover

54‧‧‧heating plate

62, 102‧‧‧ frame

64, 104‧‧‧ Baffle Department

66‧‧‧Support cover

71‧‧‧ Cover

72‧‧‧fasteners

73‧‧‧Metal plates

74‧‧‧ feet

76‧‧‧ claws

77‧‧‧Flange

106‧‧‧Pressing tablets

111‧‧‧Plunger

121‧‧‧Upper film

122‧‧‧Next film

123‧‧‧ plate spring

130‧‧‧coated film

Fig. 1 is a cross-sectional view showing a sprinkler head according to a first embodiment.

Figure 2 is an exploded cross-sectional view of the valve, holder, and elastic member.

Fig. 3(a) is an exploded perspective view of the connecting member; Fig. 3(b) is a perspective view of the connecting member (attached with a low melting point alloy).

Fig. 4 is a cross-sectional view showing a sprinkler head according to a second embodiment.

Figure 5 is a cross-sectional view of the main part of Figure 4.

Figure 6 is an exploded cross-sectional view of Figure 5.

Fig. 7 is a cross-sectional view showing an embodiment in which a coating film is provided on the surface of the lower sheet.

Fig. 8 is a cross-sectional view showing a sprinkler head according to a modification of the second embodiment.

Fig. 9 is a cross-sectional view showing a sprinkler head according to a third embodiment.

Figure 10 is a plan view of the cover of the sprinkler head of Figure 9.

Figure 11 is a cross-sectional view of the cover portion of the sprinkler head of Figure 9 before being joined.

First embodiment (Fig. 1 to Fig. 3)

The sprinkler head S1 of the present invention comprises a main body 1, a valve 2, a thermal decomposition unit 3, a holder 4, and an elastic member 5.

The body 1 is cylindrical and has a nozzle 11 inside. A male thread 12 is formed on the outside of the body 1, and the male thread 12 is screwed to a female screw of a fire extinguishing device pipe (not shown). The valve seat 13 is formed at the discharge side end portion 11a of the nozzle 11. The valve seat 13 is formed as a recess 13 recessed toward the nozzle 11, and is constituted by a bottom surface 13a and an inner circumferential surface 13b.

In the main body 1, two arms 14, 14 extending from the vicinity of the valve seat 13 to the discharge direction of the water which is discharged from the nozzle 11 as the "extinguishing liquid" are provided. The arms 14 and 14 are bent and extended from the vicinity of the valve seat 13 and connected to the extension line of the central axis of the nozzle 11, and the connecting portion is a boss 15. The boss 15 has a female thread 16 formed on the center axis of the nozzle 11, that is, the line A-A. A fixing screw 17 having no screw head is screwed to the female thread 16.

At the front end of the boss 15, a disk-shaped baffle 18 is provided. A claw that is wavy continuous is formed in the peripheral edge portion 18a of the baffle 18.

The valve 2 has a disk shape, and a sealing material 21 is provided on the surface of the nozzle 11 side. In the present embodiment, the sealing material 21 formed of a fluororesin sheet is adhered to the valve 2 by an adhesive to be integrated with the valve 2.

On the opposite side of the surface on which the sealing material 21 is provided, the step portion 22 and the hole portion 23 are formed. The bullet body 5 is placed on the step portion 22. A hole portion 23 is bored in the surface of the step portion 22, and the convex portion 42 of the holder 4 described below is inserted into the hole portion 23.

The thermosensitive decomposition unit 3 is composed of a connection plate 32, a low melting point alloy 33, a lever 34, and a support 35.

The connecting plate 32 is formed by bonding two thin metal plates 22a with a low melting point alloy 33. Composition. The connecting plate 32 has two holes 32b in a state of being attached (refer to Fig. 3(b)). The lever 32 is inserted into the lever 34 and the post 35, and is engaged with the edge of the hole 32b.

A coating containing a carbon nanotube is applied to the surface of the connecting plate 32 to apply a coating film 130. Since the heat transfer performance is improved by the coating film 130, the low melting point alloy 33 can be melted at an early stage after the fire occurs, and the sprinkler head S1 can be actuated. Further, since the corrosion resistance is improved by the coating film 130, it is possible to prevent the occurrence of corrosion products on the connecting plate 32.

The lever 34 is formed in an L shape, and one of the front ends is bent and engages with the hole 32b of the connecting plate 32. The fixing screw 17 is engaged with the groove 34a formed at the front end of the other end, and the groove 35 is engaged with the groove 34b formed on the opposite side of the groove 34a.

The stay 35 is formed in a rectangular shape, the upper end is engaged with the groove 34b of the lever 34, and the lower end is engaged with the recess 41 of the holder 4 provided on the valve 2. A projection (not shown) for locking the hole 32b of the connecting plate 32 is provided at an intermediate portion of the stay 35. In Fig. 1, the fixing screw 17 and the groove 34a of the lever 34, the holder 4, and the valve 2 are disposed on the central axis of the nozzle, that is, the line AA, and the position of the groove 34b is slightly separated from the groove 34a of the lever 34. The struts 35 are disposed slightly inclined with respect to the line AA.

When the fixing screw 17 is moved toward the lever 34 side, the stay 35 presses the holder 4 and the valve 2 to the nozzle 11 side through the lever 34 to close the nozzle 11. Further, the lever 34 acts to rotate the groove 34 of the engaging post 35 as a fulcrum in a clockwise direction. Thereby, the force of the rotational movement of the lever 34 at the end where the connecting plate 32 is engaged is applied to the upper left direction, but since the lever 34 is engaged with the connecting plate 32, the lever 34 does not rotate.

Once the low melting point alloy 33 is melted due to the heat of the fire, the two metal plates 32a, 32a constituting the connecting plate 32 become movable, and the lever 34 rotates in the clockwise direction to the metal plate. 32a, 32a pulled away. Thereby, the thermosensitive decomposition unit 3 is decomposed and the valve 2 is separated from the nozzle 11, thereby opening the nozzle 11.

The holder 4 has a disk shape and is disposed between the valve 2 and the thermal decomposition unit 3. A concave portion 41 supported on one end side of the thermal decomposition portion 3 is formed on one side of the holder (upper side in the drawing). A convex portion 42 that is inserted into the hole portion 23 of the valve 2 is formed on a surface opposite to the surface on which the concave portion 41 is formed. In the figure, the convex portion 42 is inserted into the hole portion 23, and a movable gap 6 is provided between the front end of the convex portion 42 and the bottom surface of the hole portion 23.

The elastic member 5 is a disc spring and has a function of pressing the valve 2 toward the nozzle 11 side and pressing the holder 4 toward the thermal decomposition portion 3 side. The elastic member 5 is loaded by a fixing screw 17. In other words, when the fixing screw 17 is screwed in the direction of the nozzle 11, the elastic member 5 is pressed from the front end of the fixing screw 17 through the thermal decomposition unit 3 and the holder 4, and the elastic member 5 is not completely flattened due to elastic deformation, but It is in a state of being crushed by the predetermined pressure remaining in the movable gap 6. By the state in which the elastic member 5 is crushed in the above-described manner, it is possible to obtain a state in which the closing load is applied to the valve 2 and the discharge-side end portion 11a of the nozzle 11 is closed by the valve 2.

Further, since the disk spring constituting the elastic member 5 is small in size, it is easy to be incorporated in the sprinkler head S1, and has an advantage that it can be elastically deformed with a large load. Specifically, when the pressure receiving area of the valve 2 from the nozzle 11 is 1 cm ² , when the load for displacing the disk spring 5 is about 500 N, the water pressure in the nozzle 11 reaches approximately 5 MPa. The disc spring 5 is deformed in a bullet shape and the valve 2 is separated from the valve seat 13, so that the fire extinguishing liquid in the nozzle 11 can be discharged to the outside.

Second embodiment (Fig. 4 to Fig. 7)

In the second embodiment, the constituents of the thermosensitive decomposition unit are coated with a carbon nanotube. The sprinkler head of the membrane. The sprinkler head S2 of the second embodiment shown in FIG. 4 is composed of a frame body 102, a valve 103, a baffle plate portion 104, a thermal decomposition portion 105, and a pressing piece 106. It is to be noted that the same components as those in the first embodiment are designated by the same reference numerals and will not be described.

The configuration of the sprinkler head S2 of the second embodiment is the same as that described in Japanese Laid-Open Patent Publication No. 2000-79182, and the description of the portions that are not related to the present invention will be omitted. In the sprinkler head S2, only the thermal decomposition unit 105 and the pressing piece 106 protrude from the ceiling toward the indoor side.

The thermal decomposition unit 105 is composed of a cylinder 110, a plunger 111, and a low melting point alloy 112. The cylinder block 110 is formed in a cylindrical shape, and the upper end is closed in a plane. The low melting point alloy 112 is housed inside the cylinder 110. A hole 113 penetrating through the low melting point alloy 112 is formed at the center of the upper end surface of the cylinder block 110.

The plunger 111 is formed with a shaft portion 114 and a disk-shaped crotch portion 115 at a lower end thereof. The shaft portion 114 is inserted into the hole 113, and the upper surface of the flange portion 115 is in contact with the surface of the low melting point alloy 112. A male thread 116 is disposed at an upper end of the shaft portion 114.

The pressing piece 106 is composed of an upper piece 121, a lower piece 122, and a blade spring 123.

The circular upper piece 121 and the circular lower piece 122 have the same diameter, and are slightly smaller than the inner side of the inner flange 124 formed at the lower end of the cylindrical frame 102. A female screw 125 that is screwed into the male thread 116 of the shaft portion 114 of the plunger 111 is screwed into the center of the upper piece 121.

A hole through which the shaft portion 114 can be easily inserted is formed in the center of the lower piece 122. The upper portion of the lower piece 122 is a groove, and the plate spring 123 is housed inside. A circular groove 126 for accommodating the cylinder 110 is formed at the lower portion.

The leaf spring 123 has a hole through which the shaft portion 114 can be inserted at the center of the disk-shaped bottom surface 127. A plurality of spring portions 128 extending in the oblique direction are provided at equal intervals from the periphery of the bottom surface 127. The spring portions 128 are separated by a gap. In the no-load state, the front end of the spring portion 128 is disposed on the inner side of the outer edges of the upper piece 121 and the lower piece 122.

The leaf spring 123 is disposed between the upper piece 121 and the lower piece 122, and is inserted into the shaft portion 114 of the plunger 111 at each center hole. When the male thread 116 of the shaft portion 114 is screwed to the female thread 125 of the upper piece 121, the spring portion 128 of the leaf spring 123 is crushed so as to be sandwiched between the upper piece 121 and the lower piece 122 to become the spring portion 128. The front end is exposed from the outer edges of the upper sheet 121 and the lower sheet 122. The exposed spring portion 128 is engaged with the inner flange 124 of the frame 102 as shown in FIGS. 4 and 5 .

The lower sheet 122 is formed of a resin in which a resin such as stainless steel or glass fiber of a fine carbon nanotube is mixed with a resin. Thereby, the strength or heat resistance can be improved compared with the general resin. Although the lower piece 122 is always subjected to the load by the plate spring 123, it is more durable than the general resin by improving the strength.

Further, by forming the coating film 130 on the surface of the lower sheet 122 and the inner surface of the groove 126, a heat conduction portion can be provided. The heat absorbed by the coating film 130 can be transmitted to the low melting point alloy 112 through the cylinder 110 to improve the heat conduction performance. As a specific example of the coating film 130, a copper plating or a carbon nanotube layer can be used.

Further, as shown in FIG. 7, if the coating film 130 having thermal conductivity is formed on the inner surface of the groove 126 of the lower sheet 122 and the periphery thereof, and the low melting point alloy 112 is filled inside the groove 126, the coating film can be removed from the coating film. The 130 conducts heat directly to the low melting point alloy 112 and transfers the heat to the low melting point alloy 122 efficiently. Thereby, the cylinder 110 can be eliminated by the groove 126 and the coating film 130.

Modification of the second embodiment (Fig. 8)

A water sprinkler described in Japanese Laid-Open Patent Publication No. Hei 11-299921 is a modification of the second embodiment shown in FIG. In Fig. 8, the carbon nanotube coating is applied to the surface of the cylinder 52 containing the low melting point alloy 51 contained in the thermal decomposition portion 50 or the lid 53 and the heat collecting plate 54 connected to the cylinder 52. The film 130 (not shown) improves heat transfer performance. In particular, by adhering the coating film 130 of each component to the connection portion between the cylinder 52 and the lid body 53 and the heat collecting plate 54, the heat conduction loss can be reduced.

Further, when the low melting point alloy 51 is formed in a cylindrical shape and housed inside the cylinder 52, a coating film 130 made of a carbon nanotube is formed on the surface of the low melting point alloy 51, and The heat conduction loss between the low melting point alloy 51 and the cylinder block 52 can be reduced.

Third embodiment (Fig. 9 to Fig. 11)

The sprinkler head according to the third embodiment shown in Fig. 9 is composed of a main body 61, a frame body 62, a valve 63, a baffle plate portion 64, a thermal decomposition portion 65, a support cover 66, and a cover portion 7.

The configuration of the sprinkler head according to the third embodiment is the same as the configuration described in Japanese Laid-Open Patent Publication No. 2011-218062, and the description of the parts that are not related to the present invention will be omitted. It is to be noted that the same components as those in the first embodiment are designated by the same reference numerals and will not be described.

The sprinkler head S3 of Fig. 9 is provided with a cover portion 7. The cover portion 7 is composed of a disk-shaped cover 71 and a cylindrical fastener 72. The cover plate 71 is formed of a resin material in which a carbon nanotube is mixed with a fine metal.

The above-mentioned resin material may be a method in which a carbon nanotube or a metal is mixed in a state of a resin pellet, or a method in which a resin pellet and a carbon nanotube or a metal powder are mixed and molded by a mold. In any method, carbon nanotubes are mixed inside the resin after forming. The state of the metal.

In addition, when a low melting point alloy is used as the above-mentioned resin material, since the low melting point alloy is melted by heat during molding, the fluidity of the material inside the mold is improved, and the moldability is improved. On the other hand, if a material having good heat conductivity such as copper, brass or aluminum is mixed, the thermal conductivity is improved. The cover plate 71 made of such a material has a thickness larger than that of a conventional one made of a metal plate, and is difficult to be deformed, so that it is possible to prevent the cover plate 71 from being deformed at the time of mounting. Further, the shape of the cover plate 71 can be arbitrarily formed by a mold, and in addition to the general disk shape, it can be a rectangular or hexagonal shape, a polygonal cover plate, or a dome shape or the like. shape.

The surface of the cover 71 is disposed to be exposed to the room. Therefore, the cover 71 colored in any color can be produced by molding with a mixed pigment at the time of molding.

On the back surface of the cover 71, a metal plate 73 is provided in a buried manner. Copper or brass may be used as the metal plate 73, and in the figure, three places are disposed at equal intervals in the vicinity of the periphery of the cover plate 71. The metal plate 73 is joined to the leg 74 formed at the lower end of the fastener 72 by the low melting point alloy 75.

By providing the metal plate 73, the heat absorbed on the surface of the cover plate 71 can be transmitted to the metal plate 73 through the metal component inside the cover plate 71, and the melting of the low-melting-point alloy 75 bonded to the surface of the metal plate 73 can be promoted.

The fastener 72 has a tubular shape as described above, and a leg 74 that is joined to the low melting point alloy 75 by the metal plate 73 of the cover plate 71 is provided at the lower end. The leg 74 is provided so as to correspond to the position of the metal plate 73, and the respective portions are arranged at equal intervals in the same manner as the cover plate 71 of Fig. 10 .

On the outside of the cylindrical portion of the fastener 72, a plurality of protrusions can be formed on the support cover The spiral groove 68 on the side of the 66 engages the claw 76. The claw 76 is engaged with the spiral groove 68 by inserting the claw 76 into the inside of the support cover 66. When the cover portion 7 is rotated in this state, the claws 76 are moved along the spiral groove 68, whereby the fastener 72 is housed inside the support cover 66.

A flange 77 that expands outward is formed between the leg 74 of the fastener 72 and the pawl 76. A slight gap is provided between the flange 77 and the edge of the cover plate 71. The cover portion 7 is rotated to adjust the position with the flange 77 approaching the underside of the ceiling C.

The cover portion 7 configured as described above is provided in the sprinkler head S3. When a fire occurs, the low-melting alloy 75 conducts heat absorbed from the surface thereof and heat absorbed from the surface of the cover 71 through the carbon nanotubes or metal components inside the cover 71 to the metal plate 73, and promotes Melting of the low melting point alloy 75.

When the low melting point alloy 75 is melted, the cover 71 is detached, and the baffle portion 64 and the thermal decomposition portion 65 of the sprinkler head S3 are exposed. The thermal decomposition unit 65 is accelerated by exposure to the heat of the fire, and the thermal decomposition unit 65 performs the decomposition operation. As a result, the valve 63 supported by the thermal decomposition unit 65 is detached, and water is discharged from the nozzle 11 inside the main body 61 connected to the water supply pipe, and the water collides with the baffle portion 64 to scatter in all directions to suppress the fire.

In the above embodiment, the cover 71 is made of a resin material containing a carbon nanotube, but the coating film 130 may be applied to the components of the thermal decomposition unit 65.

S1‧‧‧ sprinkler head

1‧‧‧ Ontology

2‧‧‧ valve

4‧‧‧Holding

5‧‧‧Flexible components

6‧‧‧ movable gap

11‧‧‧Nozzles

12‧‧‧ male thread

13‧‧‧Valve (recess)

14‧‧‧ Arm

15‧‧‧Seat

16‧‧‧Female thread

17‧‧‧ fixing screws

18‧‧‧ baffles

21‧‧‧ Sealing material

32‧‧‧Connecting board

34‧‧‧Leverage

34a‧‧‧ Groove

34b‧‧‧ trench

35‧‧‧ pillar

Claims (10)

A sprinkler head characterized by comprising: a body having a nozzle through which fire extinguishing water passes; a valve closing an outlet of the nozzle; and a thermal decomposition portion locked to the body and holding the valve at the nozzle The sensible thermal decomposition portion includes a low-melting-point alloy that can be melted by the heat of fire, and a material including a carbon nanotube is used as a component of the thermal decomposition portion. A sprinkler head characterized by comprising: a body having a nozzle through which fire extinguishing water passes; a valve closing an outlet of the nozzle; and a thermal decomposition portion locked to the body and holding the valve at the nozzle An sprinkler head that is detachably attached to the sprinkler head; the sprinkler head cover includes a fastener coupled to the sprinkler head, and a cover that covers and hides the sprinkler head; the cover plate and The fastener is joined by a low melting point alloy that can be melted by the heat of the fire; a material comprising a carbon nanotube is used in the cover. A sprinkler head according to claim 1 or 2, wherein the material containing the carbon nanotube is coated with a coating comprising a carbon nanotube on a surface of a heat conducting member for conducting heat to the low melting point alloy. In this way, a coating film is applied to the surface. The sprinkler head according to claim 3, wherein the coating film is applied to a surface of the connecting sheet joined by the low melting point alloy contained in the thermal decomposition portion. For example, in the sprinkler head of claim 3, wherein the heat-sensitive decomposition part is accommodated The surface of the part containing the low melting point alloy is applied to the coating film. A sprinkler head according to claim 1 or 2, wherein the coating film is applied to the surface of the low melting point alloy. A sprinkler head according to claim 1 or 2, wherein the material containing the carbon nanotubes contains a carbon nanotube and a fine metal in the resin. A sprinkler head according to claim 7, wherein a low melting point alloy is used as the metal. For example, the sprinkler head of claim 2, wherein the cover plate is embedded in the metal plate. The sprinkler head of claim 9, wherein one of the metal plates is partially exposed on a surface of the cover.