sprinkler head

Abstract

To facilitate a structure in which water release is started by operation of both of a thermo sensitive operation part using a shape memory alloy, and a thermo sensitive operation part using a fusible alloy, for enhancing productivity and reducing continuous stress applied to the fusible alloy for surely preventing operation error.SOLUTION: A sprinkler head 10 has a first thermo sensitive operation part 25 and a second thermo sensitive operation part. The first thermo sensitive operation part 25 supports a valve body 20 to a position closing a channel 16 of a head main body 12 in a state of assembling to the first thermo sensitive operation part, a heat collecting part comprising a fusible alloy 42 which is fused at a first temperature, the second thermo sensitive operation part is a ring shaped shape memory alloy 48 whose part is cut, and shifts to a memory shape in which a ring diameter is reduced at a second temperature lower than the first temperature, for increasing an assembly load and a decomposition load of the first thermo sensitive operation part 25. When receiving a hot air flow due to fire disaster, by shift to a memory shape for reducing the ring diameter of the shape memory alloy 48 of the second thermo sensitive operation part and by fusion of the fusible alloy 42 of the first thermo sensitive operation part 25, holding of the valve body 20 is released for opening the channel 16 and releasing water for fire fighting.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a closed-type sprinkler head that is activated by hot air currents from a fire to spray water. [Background technology]

[0002] Conventionally, when a closed sprinkler head is exposed to the hot air current of a fire, the fusible alloy in the heat-sensitive operating part melts, causing the heat-sensitive operating part to thermally decompose, opening the valve body and dropping the deflector downward to spray fire-extinguishing water.

[0003] FIG. 5 is an explanatory diagram showing an axial cross section of a conventional closed-type sprinkler head (Patent Document 1).

[0004] In the description of FIG. 5, the X, Y, and Z directions are perpendicular to each other. Specifically, when looking at the sprinkler head installed on the ceiling, the X direction is the left-right direction, the Y direction is the up-down direction, and the Z direction is the front-to-back direction. The +X side of the X direction is the right side, the -X side is the left side, the +Y side of the Y direction is the top side, the -Y side is the bottom side, and the +Z side of the Z direction is the front side, and the -Z side is the rear side. Because the sprinkler head is cylindrical, the X and Z directions are arbitrary. The same applies to the X, Y, and Z directions in FIGS. 1, 2, and 4, which illustrate embodiments of the present invention, and in FIGS. 6 and 7, which illustrate conventional examples.

[0005] 5, a closed sprinkler head 100 is composed of a head body 101a and a frame 101b. The head body 101a has a threaded portion at the top that connects to a water supply pipe, a flow path 102 that penetrates vertically inside, and a nozzle 104 that opens below the flow path 102, and the frame 101b is screwed and fixed to the outside of the opening of the nozzle 104. A valve body 103 is housed in the nozzle 104 from below, and the valve body 103 is fixed to the underside of a deflector 108 provided on a guide ring 109 and is held in the closed position by a heat-sensitive operating unit.

[0006] The heat-sensitive operating part is composed of a sleeve 110, a screw member 112 for pushing up the valve body, a washer-shaped spring member 113, a ring-shaped locking member 115 that is elastically deformable and can expand and contract in diameter, an upper clamping body 116, a lower clamping body 117, a tightening screw member 123, a fusible alloy 125, a heat-sensitive plate 127, and an insulating ring 128.

[0007] The upper clamping body 116 and the lower clamping body 117 clamp a ring-shaped locking member 115 between tapered surfaces formed on the outer periphery, and the outer periphery of the locking member 115 is exposed, and this exposed part is held by an inner diameter engaging portion 120 formed by protruding from the inner periphery of the lower end of the frame 101b.

[0008] The sleeve 110 is slidably fitted into a cylindrical housing portion that opens on the upper surface side of the upper clamping body 116, and a valve body pushing-up screw member 112 that urges the valve body 103 in the closing direction is screwed into the sleeve 110.

[0009] The washer-shaped spring member 113 is fixed to the sleeve 110 at the central hole-forming portion, and its peripheral edge abuts against the upper clamping body 116, urging the valve body 103 in the closing direction against the upper clamping body 116 via the sleeve 110.

[0010] A heat-sensitive plate 127 is abutted against the lower end of the cylindrical portion extending below the lower clamping body 117 via an insulating ring 128, and the lower clamping body 117 is connected to the upper clamping body 116 by screwing a fastening screw member 123 from below, via a fusible alloy 125 and a heat-sensitive plate 127, into a screw hole opening at the lower end of a cylindrical storage portion formed in the upper clamping body 116.

[0011] When the sprinkler head 100 is assembled in this manner, an elastic deformation force that tends to shrink inward of the ring-shaped locking member 115 is applied to the tapered surfaces formed on the outer periphery of the upper clamping body 116 and the lower clamping body 117, causing the upper clamping body 116 and the lower clamping body 117 to be subjected to an assembly load that pushes them apart vertically, and this assembly load is applied to the fusible alloy 125 as a force that crushes it from above and below.

[0012] When the sprinkler head 100 is exposed to a hot air current caused by a fire, the fusible alloy 125 is overheated and melted through the heat-sensitive plate 127, and is pushed out, widening the gap between the upper clamping body 116 and the lower clamping body 117. As a result, the diameter of the ring-shaped locking member 115 decreases and it disengages from the inner diameter engaging portion 120 of the frame 101b, causing the heat-sensitive operating part to fall. When the heat-sensitive operating part falls, the valve body 103, deflector 108, and guide ring 109 also fall, and the guide ring 109 is held by the inner diameter engaging portion 120 of the frame 101b, and the fire-extinguishing water discharged from the nozzle 104 hits the valve body 103 and deflector 108 and is sprayed around.

[0013] However, in the case of such conventional sprinkler heads, there is a possibility that the heat-sensitive operating part will come apart when subjected to external impact, causing a water damage accident. Therefore, as shown in Figure 6, a sprinkler head has been provided in which the heat-sensitive part will not shift or break when subjected to external impact (Patent Document 2).

[0014] The sprinkler head shown in Figure 6 is characterized by the use of a leaf spring 280 as a means for maintaining and releasing the blocked state of the nozzle. When a load is applied in the axial direction of the sprinkler head, the leaf spring deforms in both the axial direction and the direction perpendicular to the axial direction, and when the axial load is released, the leaf spring returns to its original shape by its own elasticity.

[0015] 6(A), sprinkler head 200 is composed of main body 202, cover 203, valve body 204, and heat-sensitive operating unit 205. Heat-sensitive operating unit 205 is composed of leaf spring 280, pressing piece 220, cylinder 221, plunger 222, low-melting-point alloy 223, helical spring 224, etc.

[0016] When a fire breaks out, the low-melting-point alloy 223 in the cylinder 221 melts, and the leaf spring 280 that had been holding the valve body 204 in place is disengaged. As a result, as shown in Figure 6(B), the valve body 204 comes out of the nozzle 206, and the valve body 204, leaf spring 280, retaining piece 220, cylinder 221, plunger 222, helical spring 224, etc. fall downward and stop, and water in the piping sprays out from the nozzle 206 and is sprayed into the surrounding area from the numerous spray holes 212 drilled in the cover 203.

[0017] Furthermore, a leaf spring 208 is used in the portion that receives the force of the valve body 204, and the entire circumference of the leaf spring 208 is engaged, so that even if an external impact is applied to the heat-sensitive actuation part 205, the assembly of the heat-sensitive actuation part 205 will not shift or be destroyed.

[0018] On the other hand, conventional sprinkler heads, once activated by the hot air currents caused by a fire and opening their flow paths, continue to spray water even after the fire is extinguished until the supply of fire-fighting water from the water source runs out or until a staff member checks the scene and manually closes the valve, causing significant damage. Therefore, a sprinkler head has been proposed that uses a shape-memory alloy or the like to automatically open a valve to spray fire-fighting water when the temperature rises due to a fire, and closes the valve to automatically stop spraying water when the temperature drops after the fire is extinguished (Patent Document 3).

[0019] However, such automatic opening and closing sprinkler heads using shape memory alloys have the problem that they cannot reliably open and operate the valve at a predetermined specified temperature in the event of a fire. To address this problem, an automatic opening and closing sprinkler head shown in Figure 7 has been proposed that uses a shape memory alloy to accurately open and operate the valve at a predetermined temperature in the event of a fire to spray fire-extinguishing water (Patent Document 4).

[0020] As shown in FIG. 7, the automatic opening / closing sprinkler head 300 includes a first heat-sensitive actuating portion 306 and a second heat-sensitive actuating portion 322 .

[0021] The first heat-sensitive operating unit 306 arranges a shape memory alloy 310 and a recovery spring 314 opposite each other, and when the temperature is lower than a predetermined memory recovery temperature T1, the recovery spring 314 deforms the shape memory alloy 310 to its initial shape, holding the pilot valve 312 in a water-discharge stop position, and when the memory recovery temperature T1 is reached, the force of the shape memory alloy 310 restoring to its memorized shape makes the pilot valve 315 operable to the water-discharge position.

[0022] The second heat-sensitive operating unit 322 sets a predetermined water-discharge start temperature T2 higher than the memory recovery temperature T1 by using a fusible alloy 330, and when the temperature is lower than the water-discharge start temperature T2, it keeps the pilot valve 312 closed regardless of the operating state of the first heat-sensitive operating unit 306, and when the water-discharge start temperature T2 is reached, the fusible alloy 330 melts and decomposes, releasing the closed state of the pilot valve 312 and allowing the fire-extinguishing water to be discharged.

[0023] When the temperature of the first heat-sensitive operating unit 306 drops below the memory recovery temperature T1 during water discharge caused by the operation of the second heat-sensitive operating unit 322, the recovery spring 314 deforms the shape memory alloy 310 to its initial shape, thereby operating the pilot valve 312 to a closed state and stopping the discharge of water.

[0024] As described above, the sprinkler head of Figure 7 is designed so that water discharge begins only when both the first heat-sensitive operating unit 306 and the second heat-sensitive operating unit 322 are activated. Therefore, even if the sprinkler head is damaged, for example, by being hit by an object during monitoring, it is highly unlikely that both units will be activated due to damage, and water discharge due to damage can be reliably prevented.

[0025] Furthermore, even if there is a range in the memory recovery temperature T1 of the shape memory alloy 310, the water discharge start temperature T2 can be set to a specified temperature by the fusible alloy 330 provided in the second heat-sensitive operating part 322, and this ensures the reliability of sprinkler heads using the shape memory alloy 310 and enables mass production. [Prior art documents] [Patent documents]

[0026] [Patent Document 1] Japanese Utility Model Application Publication No. 02-109661 [Patent Document 2] Japanese Patent Application Publication No. 10-071215 [Patent Document 3] Japanese Patent Application Publication No. 05-123419 [Patent Document 4] Japanese Patent Application Publication No. 11-042294 Summary of the Invention [Problem to be solved by the invention]

[0027] However, in sprinkler heads that are designed so that water discharge begins only when both the conventional heat-sensitive operating part using a shape memory alloy and the heat-sensitive operating part using a fusible alloy are activated, the heat-sensitive operating part using a shape memory alloy is provided with a valve structure using a pilot valve, which results in a complex structure that is time-consuming and labor-intensive to manufacture, and is also costly.

[0028] Furthermore, in the heat-sensitive operating part using a fusible alloy provided in a conventional sprinkler head, for example, in the case of Figure 5, the force of ring-shaped locking member 115 displacing inward is constantly applied to fusible alloy 125, and in the case of Figure 6, the force of leaf spring 280 and helical spring 224 is applied to fusible alloy 223, and continuous stress acts on the fusible alloy, so that the fusible alloy will creep and deform when installed over a long period of time, and there is a possibility that the heat-sensitive operating part will disintegrate if it is subjected to a sudden change in room temperature or an external shock, causing a water damage accident.

[0029] The present invention aims to provide a closed sprinkler head that increases productivity by simplifying the structure in which water discharge begins only when both a heat-sensitive operating part using a shape memory alloy and a heat-sensitive operating part using a fusible alloy are activated, and that reduces the sustained stress applied to the fusible alloy to reliably prevent malfunction. [Means for solving the problem]

[0030] (Sprinkler head) The present invention is a closed-type sprinkler head that is activated by the hot air current of a fire and sprays fire-extinguishing water, a head body having a flow path formed therein that communicates in the vertical direction; a valve body that closes a flow path in the head body; a first heat-sensitive actuation unit that holds the valve body in a position that closes the flow path in a state in which a heat collecting unit having a fusible alloy that melts at a predetermined first temperature is assembled; a second heat-sensitive actuation unit made of a shape memory alloy that increases an assembly load of the first heat-sensitive actuation unit to exceed a predetermined disassembly load by transitioning to a predetermined memorized shape at a predetermined second temperature that is lower than the first temperature; Equipped with When exposed to hot airflow caused by a fire, the shape memory alloy in the second heat-sensitive operating section transitions to a memorized shape and the fusible alloy in the first heat-sensitive operating section melts, releasing the valve body's hold, opening the flow path and releasing fire-fighting water.

[0031] (First heat-sensitive operating unit and second heat-sensitive operating unit) The shape memory alloy of the second heat-sensitive actuation unit is a ring-shaped member with a portion cut out, the memorized shape transitioned to at the second temperature is a shape in which the ring diameter of the ring-shaped member is reduced; The first heat-sensitive operating unit is a cylindrical frame disposed below the head body and opening downward; a pair of upper and lower clamping bodies that clamp a ring-shaped shape memory alloy in a state where a part of the outer periphery of the ring-shaped shape memory alloy is exposed; an inner diameter engaging portion formed on the inner periphery of the lower end of the frame, which engages with and holds an exposed portion of the outer periphery of the ring-shaped shape memory alloy clamped between the pair of upper and lower clamping bodies; a sleeve that is slidably fitted into a cylindrical housing portion that opens on the upper surface side of the upper holding body and into which a valve body pushing-up screw member that urges the valve body in a closing direction is fitted; a washer-shaped spring member that is fixed to the sleeve at the central hole-forming portion and has its peripheral edge abutted against the upper clamping body, and that biases the valve body in a closing direction against the upper clamping body via the sleeve; a heat-sensitive plate abutting against the lower end of a cylindrical portion extending downward from the lower clamping body; a fastening screw member that connects the lower clamping body to the upper clamping body by being screwed from below through a fusible alloy and a heat-sensitive plate into a screw hole that opens at the lower end of a cylindrical housing portion formed in the upper clamping body; will be established. [Effects of the Invention]

[0032] (Basic effect) The present invention is a closed-type sprinkler head that is activated by the hot air current of a fire and sprays fire-extinguishing water, and comprises: a head body having a flow path formed therein that communicates in the vertical direction; a valve body that closes the flow path of the head body; a first heat-sensitive operating unit that holds the valve body in a position that closes the flow path when a heat collection unit having a fusible alloy that melts at a predetermined first temperature is assembled; and a second heat-sensitive operating unit made of a shape-memory alloy that transitions to a predetermined memorized shape at a predetermined second temperature that is lower than the first temperature, thereby increasing the assembly load of the first heat-sensitive operating unit so that it exceeds a predetermined disassembly load.When exposed to the hot air current of a fire, the shape-memory alloy of the second heat-sensitive operating unit transitions to its memorized shape and the fusible alloy of the first heat-sensitive operating unit melts, releasing the hold of the valve body and opening the flow path to spray fire-extinguishing water.Since water spraying begins only when both the first and second heat-sensitive operating units are activated, even if the first and second heat-sensitive operating units are damaged, for example by hitting an object during monitoring, it is highly unlikely that both will be activated due to damage, and water spraying due to damage can be reliably prevented.

[0033] In addition, the shape memory alloy of the second heat-sensitive operating unit transitions to its memorized shape when exposed to a hot air current caused by a fire, increasing the assembly load of the first heat-sensitive operating unit to exceed the specified disassembly load.Since the shape memory alloy of the second heat-sensitive operating unit does not transition to its memorized shape during normal monitoring, the assembly load applied to the first heat-sensitive operating unit by the shape memory alloy is kept low, which reduces the sustained stress applied to the fusible alloy of the first heat-sensitive operating unit, reduces creep deformation, and makes it possible to reliably prevent the heat-sensitive operating unit from malfunctioning due to creep deformation during long-term installation.

[0034] In addition, the shape memory alloy of the second heat-sensitive operating part transitions to a memorized shape when exposed to hot air currents caused by a fire, increasing the assembly load of the first heat-sensitive operating part, thereby ensuring reliable operation of the first heat-sensitive operating part in the event of a fire.

[0035] (Effects of the first and second heat-sensitive operating units) The shape memory alloy of the second heat-sensitive actuation unit is a ring-shaped member with a portion cut out, and the memory shape that transitions at the second temperature is a shape obtained by reducing the ring diameter of the ring-shaped member. The first heat-sensitive actuation unit comprises a cylindrical frame that is disposed below the head body and opens downward, a pair of upper and lower clamping bodies that clamp the ring-shaped shape memory alloy with a portion of the outer periphery exposed, an inner diameter engaging portion formed by projecting from the inner periphery of the lower end of the frame that engages and holds the exposed portion of the outer periphery of the ring-shaped shape memory alloy clamped between the pair of upper and lower clamping bodies, and a valve body pushing-up screw member that is slidably fitted into a cylindrical housing portion that opens on the upper surface side of the upper clamping body and biases the valve body in the closing direction. The second heat-sensitive operating part is provided with a fitted sleeve, a washer-shaped spring member that is fixed to the sleeve at the central hole forming portion and has its peripheral edge abutting against the upper clamping body, and that urges the valve body in the closing direction against the upper clamping body via the sleeve, a heat-sensitive plate abutting against the lower end of the cylindrical portion extending below the lower clamping body, and a tightening screw member that connects the lower clamping body to the upper clamping body by screwing it from below through the fusible alloy and heat-sensitive plate into a screw hole that opens at the lower end of the cylindrical storage portion formed in the upper clamping body.As a result, the second heat-sensitive operating part only requires the provision of a ring-shaped shape memory alloy with a portion cut out, making the structure extremely simple, thereby reducing costs and increasing productivity.

[0036] Furthermore, the first heat-sensitive operating unit can utilize the structure of a conventional heat-sensitive operating unit that uses a fusible alloy, and even when combined with a second heat-sensitive operating unit that uses a shape memory alloy, the structure becomes extremely simple, reducing costs and increasing productivity. [Brief explanation of the drawings]

[0037] [Figure 1]1 is an explanatory diagram showing an embodiment of a sprinkler head according to the present invention. [Figure 2] FIG. 2 is an explanatory diagram showing the shape memory alloy of FIG. 1. [Figure 3] 3 is a graph showing the change in elastic modulus with respect to temperature of the shape memory alloy of FIG. 2. [Figure 4] FIG. 2 is an explanatory diagram showing the sprinkler head of FIG. 1 activated by hot air currents caused by a fire. [Figure 5] FIG. 1 is an explanatory diagram showing a conventional closed-type sprinkler head. [Figure 6] FIG. 1 is an explanatory diagram showing a conventional closed-type sprinkler head that does not malfunction due to external impact. [Figure 7] FIG. 1 is an explanatory diagram showing a conventional sprinkler head in which water discharge is initiated by the activation of both a heat-sensitive actuating element using a shape memory alloy and a heat-sensitive actuating element using a fusible alloy. DETAILED DESCRIPTION OF THE INVENTION

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sprinkler head according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0039] [Basic concept of the embodiment] First, the basic concept of the embodiment will be described. The embodiment generally relates to a closed sprinkler head that is activated by hot air currents from a fire to spray water for extinguishing a fire.

[0040] Here, a "sprinkler head" is a device used in a sprinkler system to spray water for fire extinguishing. Also, a "sprinkler system" is a fire extinguishing system that automatically performs everything from detecting a fire to spraying water using sprinkler heads installed in the ceiling or under the roof of a fire-resistant structure.

[0041] Sprinkler systems can be broadly classified into closed sprinkler systems, open sprinkler systems, and water discharge sprinkler systems depending on the sprinkler heads used.

[0042] A "closed sprinkler system" is a sprinkler system that uses the "closed sprinkler head" of the present invention, in which the water outlet is always closed. There are three types of "closed sprinkler systems": "wet sprinkler systems," "dry sprinkler systems," and "pre-action sprinkler systems," and all of these systems use "closed sprinkler heads."

[0043] A "wet sprinkler system" is a system in which the piping from a pressurized water supply device (fire pump) through a water flow detection device to a sprinkler head is constantly filled with pressurized water, and water is automatically sprayed when the sprinkler head is heat-sensitive and opens in response to the hot air currents of a fire.

[0044] A "dry sprinkler system" is one in which the piping from the water flow detection device to the sprinkler head is not filled with water, but instead is filled with compressed air.When the sprinkler head is activated by heat from the hot air current of a fire and the compressed air in the piping is discharged, the water flow detection device opens due to the pressure difference, and water is filled in the piping and sprayed.

[0045] A "pre-action sprinkler system" is a dry sprinkler system that is linked to a fire detector. When the fire detector is activated, the pre-action valve opens, filling the pipes with water, and then the sprinkler head opens when it is heat-sensitive, automatically spraying water. Even if the sprinkler head is damaged for reasons other than fire, it will not spray water unless the fire detector is activated.

[0046] An "open sprinkler system" is a fire extinguishing system that uses open sprinkler heads that do not have a heat-sensitive operating part and are always open. A "water sprinkler system" is a system that is installed in a large space or with a high ceiling and sprays water from fixed sprinkler heads fixed to the wall or ceiling, and a system that sprays water from movable sprinkler heads known as water cannons. Neither system uses the "closed sprinkler head" of this embodiment.

[0047] The closed sprinkler head of this embodiment is comprised of a head body, a valve body, a first heat-sensitive actuation part, and a second heat-sensitive actuation part.

[0048] Here, the "head body" refers to a part that has a threaded portion at the top for connecting to a pipe and has a flow path formed inside that communicates in the vertical direction. The "valve body" is a part that closes the flow path in the head body.

[0049] The "first heat-sensitive actuation unit" is a unit that holds the valve body in a position that closes the flow path of the head body when a heat collecting unit equipped with a fusible alloy that melts at a predetermined first temperature, for example, 74°C, is attached. As an example, the first heat-sensitive actuation unit corresponds to a conventional heat-sensitive actuation unit equipped with a fusible alloy.

[0050] In addition, the "second heat-sensitive operating part" is composed of a shape memory alloy that increases the assembly load of the first heat-sensitive operating part to exceed a predetermined disassembly load by transitioning to a predetermined memory shape at a predetermined second temperature, for example 50°C, which is lower than the first temperature at which the fusible alloy melts.

[0051] The sprinkler head of this embodiment, configured in this manner, will only begin to spray water when it is exposed to a hot air current caused by a fire if both the first heat-sensitive operating unit and the second heat-sensitive operating unit are activated.Therefore, even if the sprinkler head is damaged, for example by being hit by an object, during normal monitoring, it is highly unlikely that both units will be activated due to damage, and water spraying due to damage can be reliably prevented.

[0052] In addition, since the shape memory alloy of the second heat-sensitive operating part does not transition to its memorized shape during normal monitoring, the assembly load applied to the first heat-sensitive operating part by the shape memory alloy is kept low, which reduces the sustained stress applied to the fusible alloy of the first heat-sensitive operating part, thereby reducing creep deformation and reliably preventing the heat-sensitive operating part from malfunctioning due to creep deformation during long-term installation.

[0053] In addition, the shape memory alloy of the second heat-sensitive operating part transitions to a memorized shape when exposed to hot air currents caused by a fire, increasing the assembly load of the first heat-sensitive operating part, thereby ensuring reliable operation of the first heat-sensitive operating part in the event of a fire.

[0054] Specific embodiments will be described below. In the specific embodiments shown below, the "shape memory alloy constituting the second heat-sensitive operation unit" is, for example, a "ring-shaped member with a portion cut out," and the "memorized shape to which it transitions at a second temperature" is a "shape in which the ring-shaped member contracts toward its inner diameter," and when subjected to a hot air flow due to a fire, it transitions to a memorized shape that contracts toward its inner diameter, thereby increasing the assembly load of the first heat-sensitive operation unit to exceed a predetermined disassembly load.

[0055] [Specific details of the embodiment] We will now explain sprinkler heads in more detail. The details will be divided into the following sections: a. Sprinkler head structure b. Shape memory constituting the second heat-sensitive actuation part alloy c. Water discharge due to thermal decomposition of the first heat-sensitive operating part d. Modifications of the present invention]

[0056] [a. Structure of sprinkler head] The structure of the sprinkler head will now be described in more detail with reference to Figure 1, which shows an embodiment of the sprinkler head according to the present invention.

[0057] As shown in FIG. 1, a closed sprinkler head 10 according to this embodiment is composed of a head body 12 and a frame 14, and the cylindrical frame 14 is screwed and fixed to the protruding portion of the head body 12.

[0058] Head body 12 has a threaded portion 12a at the top for connection to a water supply pipe, and a flow path 16 penetrating vertically inside, with a nozzle 18 opening below flow path 16. Nozzle 18 houses a valve element 20 with a seal 22 attached from below, and valve element 20 is fixed to the underside of a deflector 26 provided on a guide ring 24, and is held in the closed position by a first heat-sensitive operating part 25 using a fusible alloy 42.

[0059] The first heat-sensitive operating part 25 is composed of an upper clamping body 28 formed in a funnel shape, a lower clamping body 30 also formed in a funnel shape, a sleeve 32, a valve body pushing-up screw member 34, a washer-shaped spring member 36, an insulating ring 38, a heat-sensitive plate 40, a fusible alloy 42, and a tightening screw member 46.

[0060] The upper clamping body 28 and the lower clamping body 30 have tapered surfaces 28a, 30a formed on their outer peripheries that open in a "L" shape toward the outer periphery, and the inner periphery of a ring-shaped shape memory alloy 48 with a portion cut out that constitutes the second heat-sensitive operating part is clamped between the tapered surfaces 28a, 30a, with the outer periphery of the shape memory alloy 48 exposed, and this exposed portion is held by an inner diameter engagement portion 14a formed by protruding from the inner periphery of the lower end of the frame 14.

[0061] Here, if the inner diameter of the inner peripheral end of the inner diameter engaging portion 14a of the frame 14 is D0 and the outer diameter of the shape memory alloy 48 in its initial shape is D1, then: D0 <D1 By setting this relationship, the exposed portion on the outer periphery of the shape memory alloy 48 is held by the inner diameter engaging portion 14a formed by protruding from the inner periphery of the lower end of the frame 14. Note that the "initial shape of the shape memory alloy 48" refers to the predetermined shape that is memorized at a predetermined memorization temperature and then deformed by returning to a low temperature state (room temperature).

[0062] The sleeve 32 is slidably fitted into a cylindrical housing portion that opens on the upper surface side of the upper clamping body 28, and a valve body pushing-up screw member 34 that urges the valve body 20 in the closing direction is screwed into the sleeve 32.

[0063] The washer-shaped spring member 36 is fixed to the upper side of the sleeve 32 at the central hole forming portion, and the lower edge of its outer periphery abuts on the upper clamping body 28, urging the valve body 20 in the closing direction (upward) against the upper clamping body 28 via the sleeve 32.

[0064] A heat-sensitive plate 40 is abutted against the lower end of the cylindrical portion extending downward of the lower clamping body 30 via an insulating ring 38, and by screwing a tightening screw member 46 from below into a screw hole opening at the lower end of the cylindrical storage portion formed in the upper clamping body 28, the lower clamping body 30 is connected to the upper clamping body 28 with the fusible alloy 42 and heat-sensitive plate 40 sandwiched between the flange portion 46a.

[0065] The structure of the first heat-sensitive actuation portion 25 is basically the same as the conventional structure shown in FIG. 5, except that the shape memory alloy 48 that constitutes the second heat-sensitive actuation portion is provided.

[0066] [b. Shape memory alloy constituting the second heat-sensitive operating portion] The shape memory alloy constituting the second heat-sensitive operating part will be described in more detail below. In this description, reference will be made to Figure 2, which shows the shape memory alloy of Figure 1, and Figure 3, which is a graph showing the change in elastic modulus with temperature of the shape memory alloy of Figure 2. Note that Figure 2(A) shows a plan view, and Figure 2(B) shows a side view.

[0067] As shown in Figure 2, the shape memory alloy 48 constituting the second heat-sensitive operating part is a ring-shaped member with a circular cross section and a cutout, and a ring split part 50 with a pin hole is formed in the cutout part of the ring, and the outer diameter is set to D1 as the initial shape.

[0068] Any material may be used for the shape memory alloy 48, but for example, a unidirectional material with high corrosion resistance, such as a NiTi alloy, is used. Here, "unidirectional shape memory alloy" means that after a predetermined shape is memorized at a predetermined memory temperature, the alloy is deformed to its initial shape at a low temperature (room temperature), and then when heated to a memory temperature equal to or higher than the transformation point, it transitions to the memorized shape, but does not transition to the initial shape even when returned to a low temperature state thereafter.

[0069] The memorized shape of such a one-way shape memory alloy 48 is set as follows: First, a pinhole provided in the ring divided portion 50a of the shape memory alloy 48 is used to reduce the ring diameter in the inward direction to set the shape of the shape memory alloy 48a so that the outer diameter is D2, as shown by the imaginary line, and then the shape of the shape memory alloy 48a is memorized by heating it to a predetermined memorization temperature.

[0070] Next, after the shape memory alloy 10a that has completed shape memory is returned to a low temperature state (room temperature state), the pinholes provided in the ring divided portion 50a are used to expand the shape memory alloy 48 to an outer diameter D1, and this is set to its initial shape. Then, the shape memory alloy 48 that has been set to its initial shape after shape memory is clamped between the tapered surfaces 28a, 30a of the upper clamping body 28 and the lower clamping body 30 shown in Figure 1, and the outer exposed portion of the shape memory alloy 48 is held by the inner diameter engaging portion 14a of the frame 14.

[0071] Here, the inner diameter D0 of the inner peripheral end of the inner diameter engaging portion 14a of the frame 14 in which the shape memory alloy 48 shown in FIG. 1 is placed, the outer diameter D1 of the initial shape of the shape memory alloy 48 shown in FIG. 2, and the outer diameter D2 of the shape memory alloy 48a after shape memory are as follows: D1>D0>D2 The relationship is set.

[0072] The transition force (restoring force) of the shape memory alloy 48 from its initial shape to its memorized shape at low temperatures is sufficiently low, and when it is clamped between the tapered surfaces 28a, 30a of the upper clamping body 28 and the lower clamping body 30, it hardly acts as a decomposing load that pushes the upper clamping body 28 and the lower clamping body 30 apart vertically.

[0073] Therefore, in a low-temperature state in which the shape memory alloy 48 is in its initial shape, the fusible alloy 42 is only subjected to the assembly load from the tightening screw member 46, and as in the conventional sprinkler head 100 shown in Figure 5, the elastic deformation force that tries to shrink inward of the ring-shaped locking member 115 pushes the upper clamping body 116 and the lower clamping body 117 apart, and this is not applied as a continuous stress to the fusible alloy 42, reducing the creep deformation of the fusible alloy 42 and reliably preventing malfunction of the first heat-sensitive operating part 25.

[0074] In contrast, when the sprinkler head 10 receives the hot air flow caused by a fire and the shape memory alloy 48 incorporated in the first heat-sensitive operating part 25 becomes heated, the shape memory alloy 48 shrinks in the inner diameter direction and attempts to transition to the memorized shape of the outer diameter D2, generating a force that pushes the upper clamping body 28 and the lower clamping body 30 apart in the vertical direction, thereby increasing the decomposition load.

[0075] Here, if the predetermined water discharge start temperature (first temperature) determined by the melting temperature of the fusible alloy 42 at which the first heat-sensitive operating unit 25 operates is T1, and the predetermined memory temperature (second temperature) of the shape memory alloy 10 that constitutes the second heat-sensitive operating unit is T2, the memory temperature T2 of the shape memory alloy 10 is set to a lower predetermined temperature than the water discharge start temperature T1.

[0076] Therefore, when exposed to a hot air current caused by a fire, the temperature first rises to a predetermined memory temperature T2 of the shape memory alloy 10, and the shape memory alloy 48 shrinks in the inner diameter direction and attempts to transition to its memory shape, generating a force that pushes the upper clamping body 28 and the lower clamping body 30 apart in the vertical direction, thereby increasing the decomposition load.

[0077] Next, when the fusible alloy 42 reaches the water discharge start temperature T1, the first heat-sensitive operating part 25 is decomposed and the shape memory is formed during the decomposition process. alloy 48 shrinks from the outer diameter D1 of the initial shape to the outer diameter D2 of the memorized shape, becoming smaller than the inner diameter D0 of the inner peripheral end of the inner diameter engagement portion 14a of the frame 14, causing the first heat-sensitive operating portion 25 to fall away from the inner diameter engagement portion 14a, releasing the hold on the valve body 20 and starting to discharge water.

[0078] The water discharge start temperature T1 of the fusible alloy 42 at which this water discharge begins is precisely determined by the material of the fusible alloy 42. On the other hand, as shown in Figure 3, the crystal structure of the shape memory alloy 48 transitions from the martensite phase to the austenite phase in response to an increase in temperature T from the low temperature range to the high temperature range, and a two-phase region where the martensite phase and the austenite phase coexist exists as a shape memory region between them, and the elastic modulus G, which corresponds to the transition force (restoring force) to the memorized shape, has the characteristic of increasing over a certain range in response to an increase in temperature in the shape memory region.

[0079] Therefore, since the memory temperature T2 of the shape memory alloy 48 is the temperature before the start of water discharge, even if the transition force (restoring force) corresponding to the elastic coefficient G at which the shape memory alloy 10 transitions to its memory shape increases over a certain range in response to an increase in temperature, as shown in Figure 3, water can be reliably discharged at the specified water discharge start temperature T1 determined by the material of the fusible alloy 42 without being affected by this.

[0080] The water discharge start temperature T1 and the memory temperature T2 of the shape memory alloy 48, which are determined by the fusible alloy 42 of the first heat-sensitive operating part 25, are arbitrary, but for example, if the water discharge start temperature T1 is 74°C and the temperature range of the shape memory region where the decomposition load is increased by the transition of the shape memory alloy 48 to its memory shape is 30 to 60°C, the memory temperature T2 is set to 50°C, for example.

[0081] 3 is 50°C, the transition force (restoring force) of the shape memory alloy 48 based on the elastic modulus G2 exceeds a predetermined decomposition load required to decompose the first heat-sensitive actuation unit 25. As a result, when the temperature of the shape memory alloy 48 reaches the memory temperature T2=50°C, the transition force (restoring force) of the shape memory alloy 48 increases the decomposition load of the first heat-sensitive actuation unit 25, bringing it into a state where water can be discharged, and then, when the water discharge start temperature T1=74°C is reached, the fusible alloy 42 melts, causing the first heat-sensitive actuation unit 25 to decompose and start discharging water.

[0082] [c. Water release due to thermal decomposition of the first heat-sensitive operating part] The discharge of water by thermal decomposition of the first heat-sensitive actuation element will now be described in more detail with reference to Figure 4, which shows the sprinkler head of Figure 1 actuated by the hot air current caused by a fire.

[0083] When the temperature of the shape memory alloy 48 provided as a second heat-sensitive operating part in the sprinkler head 10 exposed to the hot air current caused by a fire reaches a predetermined memory temperature T2, the shape memory alloy 48, which was in its initial shape of outer diameter D1, shrinks in the inner diameter direction and attempts to transition to the memory shape of outer diameter D2, thereby increasing the decomposition load that pushes the upper clamping body 28 and the lower clamping body 30 apart vertically, and increasing the force that crushes the fusible alloy 42 from above and below.

[0084] Subsequently, when the temperature of the fusible alloy 42 reaches the water discharge start temperature T1, the fusible alloy 42 melts and is pushed out, widening the vertical gap between the upper clamping body 28 and the lower clamping body 30. As a result, the diameter of the shape-memory metal 48, which was in its initial shape with outer diameter D1, shrinks and transitions to a memorized shape with outer diameter D2, disengaging from the inner diameter engaging portion 14a of the frame 14, and the first heat-sensitive operating portion 25 drops, as shown in FIG.

[0085] When the first heat-sensitive operating part 25 falls, the valve body 20, deflector 26 and guide ring 24 also fall, and the guide ring 24 is held by the inner diameter engagement part 14a of the frame 14, and the fire-extinguishing water discharged from the nozzle 18 hits the valve body 20 and deflector 26 and is sprayed around.

[0086] [d. Modifications of the present invention]

[0087] Modifications of the sprinkler head according to the present invention will now be described. In addition to the above-described embodiment, the sprinkler head according to the present invention includes the following modifications.

[0088] The structure of the first heat-sensitive operating part of the present invention is not limited to the above embodiment, and can be applied to any appropriate heat-sensitive operating part as long as it has a structure in which a heat collection part equipped with a fusible alloy is attached to an integrated part on the frame side via an insulating member.

[0089] In the above embodiment, the shape memory alloy 48 is a ring-shaped member with a circular cross section and a cutout portion, but the cross section is not limited to a circular one, and may be a tapered surface. 28a,30a The cross section may be any shape that abuts or contacts with the three points of the inner diameter engaging portion 14a, and may be, for example, an ellipse, a polygon having more than a rectangle, or the like.

[0090] Furthermore, the present invention is not limited to the above-described embodiments, but includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited by the numerical values ​​shown in the above-described embodiments. [Explanation of symbols]

[0091] 10: Sprinkler head 12: Head body 14: Frame 14a: Inner diameter engagement part 16: Flow path 18: Nozzle 20: Valve body 22: Seal 24: Guide ring 25: First heat-sensitive operating unit 26: Deflector 28: Upper clamping body 28a, 30a: Tapered surface 30: Lower clamping body 32: Sleeve 34: Valve body push-up for Screw material 36: Spring material 38: Insulation ring 40: Thermal plate 42: Fusible alloy 46: Fastening screw member 46a: Flange part 48:Shape memory alloy 50: Ring division section

Claims

1. A closed sprinkler head that is activated by the hot air current of a fire and sprays fire-extinguishing water, a head body having a flow path formed therein that communicates in the vertical direction; a valve body that closes the flow path of the head body; a first heat-sensitive actuation unit that holds the valve body at a position that closes the flow path in a state in which a heat collecting unit having a fusible alloy that melts at a predetermined first temperature is attached; a second thermally sensitive actuating unit made of a shape memory alloy that transitions to a predetermined memorized shape at a second predetermined temperature lower than the first temperature, thereby increasing an assembly load of the first thermally sensitive actuating unit to exceed a predetermined disassembly load; Equipped with the shape memory alloy is a ring-shaped member with a portion cut out, the memorized shape is a shape obtained by reducing the ring diameter of the ring-shaped member, A sprinkler head characterized by the fact that, when exposed to a hot air current caused by a fire, the shape memory alloy of the second heat-sensitive operating part transitions to the memorized shape and the fusible alloy of the first heat-sensitive operating part melts, thereby releasing the retention of the valve body and opening the flow path to release fire-extinguishing water.

2. 2. The sprinkler head of claim 1, The first heat-sensitive actuation unit is a cylindrical frame disposed below the head body and opening downward; a pair of upper and lower clamping bodies that clamp the ring-shaped shape memory alloy in a state where a part of the outer periphery of the ring-shaped shape memory alloy is exposed; an inner diameter engaging portion formed on the inner periphery of the lower end of the frame, which engages with and holds an exposed portion of the outer periphery of the ring-shaped shape memory alloy sandwiched between the pair of upper and lower sandwiching bodies; a sleeve that is slidably fitted into a cylindrical housing portion that opens on the upper surface side of the upper holding body, and into which a valve body pushing-up screw member that urges the valve body in a closing direction is fitted; a washer-shaped spring member that is fixed to the sleeve at a central hole-forming portion and has a peripheral edge that abuts against the upper clamping body, and that biases the valve body in a closing direction against the upper clamping body via the sleeve; a heat-sensitive plate abutting against the lower end of a cylindrical portion extending downward from the lower clamping body; a fastening screw member that connects the lower clamping body to the upper clamping body by being screwed from below through the fusible alloy and the heat-sensitive plate into a screw hole that opens at the lower end of the cylindrical housing portion formed in the upper clamping body; A sprinkler head characterized by being provided with:

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