JPH11167682A - Heat sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sensor which can sense the heat of fire with simple constitution without irregularity in a thermosensitive element by filling a thermosensitive element into the tip part of a metallic protection pipe and providing a heat collection mechanism in the protection pipe. SOLUTION: The thermosensitive element 60 is filled in the tip part of the metallic protection pipe 62 and the heat collection mechanism 7 is provided for the protection pipe 62. The heat sensor has the thermosensitive part 6 obtained by inserting the metallic protection pipe 62 where the thermosensitive element 60 is filled into the tip part into the through hole 65 of the hollow bolt 64 so as to fix it. The thermosensitive element 60 is brought into contact with the tip part in the protection pipe 62 and is filled and filler 63 is filled into a filing space. In the protection pipe 62 in which the thermosensitive element 60 is filled, the base part is inserted into the through hole 65, the tip part is made to protrude and it is air-tightly fixed to the hollow bolt 64 at a brazing part 67. In the heat collection mechanism 7, a heat collection board is constituted of a metallic and circular disk 71 with high heat conductivity such as aluminum and it is fixed to the vicinity of the tip of the protection pipe 62 with fusing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sensor, and more particularly, to a heat sensor for detecting a fire by utilizing a change in electrical characteristics of a heat sensing element such as a thermistor due to heat. is there.

[0002]

2. Description of the Related Art FIG. 11 is a sectional view of a conventional sensor of this type, and FIG. 12 is a sectional view of an element unit.
A drawing and a numerical symbol described in JP 0791 are shown.
In FIG. 11, 11 is an element unit, 12 is a fitting, 12a and 12d are horizontal and vertical parts of the fitting 12,
Reference numeral 13 denotes an outer cover, 14 denotes a mold main body having the element unit 11 protruded in the center, 15 denotes a circuit housing portion, 16 denotes a circuit board, 17 denotes a cover member, 24 denotes an O-ring, and 25 denotes a protective cover. In FIG. 12, reference numeral 1 denotes a temperature measuring element;
1 is the same element unit as above, 20 is a lead frame,
21 is a unit main body, 22 is a lead wire, and 23 is a coating material covering around the element unit 11.

In manufacturing the above-described conventional sensor, an element unit 11 shown in FIG. 12 and a fitting 12 bent in a predetermined shape are prepared in advance. The prepared element unit 11 and a pair of fittings 12 are set in a mold for resin-molding the mold body 14. In this state, insert molding is performed to form a mold body 14 in which the element unit 11 and the fitting 12 are embedded. A circuit board 16 on which circuit components have been mounted is placed in a circuit storage section 15 of the formed mold body 14. The lead frame 20 of the element unit 11 and the vertical portion 12d of the fitting 12 are inserted into predetermined positions of the arranged circuit board 16 and soldered to the circuit pattern.

Next, an O-ring 2 is
4 and cover the cover member 17, and fix the outer cover 13 with four screws (not shown), and the mold body 14 is assembled to the outer cover 13. The sensor main body composed of the outer cover 13 and the mold main body 14 joined by four screws fits the horizontal portion 12a of the fitting 12 into the fitting of the sensor base (not shown) and attaches it to the ceiling surface or the like. It is attached.
Then, the temperature measuring element 1 such as a thermistor in the element unit 11 electrically detects the temperature at the time of the occurrence of the fire, and the fire is sensed.

[0005]

Generally, the hot air flow generated by the occurrence of a fire rises rapidly by increasing the flow velocity while involving the air flow in the peripheral area. Therefore, the temperature of the hot air flow at the time of fire tends to be uneven, and the temperature gradient with respect to the time of the hot air flow at the time of fire tends to be remarkably large. On the other hand, the element unit 11 that constitutes the heat-sensitive part of the conventional sensor is configured to dissipate the heat of fire by the temperature measuring element 1 at the tip of the element unit 11 that is simply protruded outside from the outer cover 13 as described above. It is designed to sense. Therefore, if the temperature of the hot air flow that rises while entraining the surrounding air in the event of a fire is uneven, the responsiveness of heat sensing often decreases. In addition, since the entire temperature measuring element 1 is covered with the coating material 23, there has been a problem that heat responsiveness in a fire is further reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional sensor. The heat of the fire can be uniformly detected by the heat sensing element with a simple structure, and the heat can be changed rapidly. It is an object of the present invention to realize a heat sensor that senses a hot air flow to enhance responsiveness, and that is robust, has few failures and can withstand long-term use.

[0007]

SUMMARY OF THE INVENTION The present invention has a heat-sensitive portion in which a heat-sensing element for sensing a fire by utilizing a change in electrical characteristics due to heat is provided upright in a heat-sensing direction of a mounting surface of a container cover. In the heat sensor, a heat sensor is formed by enclosing a heat sensing element at the tip of a metal protective tube and providing a heat collecting mechanism in the protective tube. Further, the heat collecting mechanism constitutes a heat detector constituted by a disk attached in a direction perpendicular to the protective tube. In addition, a heat sensor in which a ventilation part is provided in the heat collecting mechanism is configured. In addition, a heat detector in which a heat collecting mechanism is provided with a three-dimensional heat receiving surface is provided. In addition, a heat sensor in which a heat collecting mechanism is detachable is configured. Further, a heat detector in which a heat collecting mechanism is fixed to a protection tube is formed.

[0008] After the protective tube enclosing the heat sensing element filled with the filler is inserted into the through hole of the hollow bolt,
The tip is projected and fixed to the hollow bolt by brazing. The heat-sensing portion, in which the heat collecting mechanism is assembled to the protection tube fixed to the hollow bolt, is screwed into the screw hole to stand upright at the center of the container cover. Next, the spacer is fixed to the inner surface of the container cover, and the printed circuit board is mounted thereon. The core wire of the lead wire of the heat sensing element pulled out from the insertion hole of the attached printed board is soldered to a connection point of the printed board. With the soldering connection of the core wire,
A thermal sensing element is connected to a sensor circuit mounted on a printed circuit board.

Subsequently, after connecting the internal wiring drawn out of the printed board to the screw terminal of the terminal block, the partition plate is connected to the container cover, and the printed board is housed in the housing chamber. Thereafter, the O-ring is fitted into the groove formed by the cutout on the outer periphery of the partition plate attached to the container cover while slightly extending it. Then, the outer periphery of the partition plate is fitted into the opening of the container base, and a bolt is tightened with a hexagon wrench to fix the container cover to the container base, thereby assembling the heat detector. The assembled heat sensor is installed on the ceiling to monitor fires in the monitoring area. Should a fire occur, the heat collecting mechanism senses the heat of the fire quickly and evenly and transmits it to the heat sensing element.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is an enlarged cross-sectional view showing the structure of a heat-sensitive part according to Embodiment 1 of the present invention, FIG. 2 is an exploded perspective view showing the structure near the heat-sensitive part of Embodiment 1, and FIG. Sectional view of the sensor, FIG.
Is a side view of the heat sensor of the first embodiment, FIG. 5 is a bottom view of the heat sensor of the first embodiment, and FIG. 6 is a top view of the terminal block. FIG.
In 1 to 6, 1 is a ceiling surface, and 2 is a heat detector attached to the ceiling surface 1. 3 is a container cover of the heat detector 2, 4
Is a hollow disk-shaped partition plate, and 5 is a thin closed cylindrical container base. The container 10 of the heat detector 2 is constituted by the container cover 3 and the container base 5.

A metal material is used for the container cover 3, the partition plate 4, and the container base 5, and is manufactured by, for example, die-casting aluminum. After molding, the surface and the like of the joint surface are finished through a processing step of a machine tool or the like, and are joined by a plurality of screws. In the container cover 3, reference numeral 31 denotes a protective frame protruding toward the bottom side of the container cover 3, and 32 denotes a protective frame 31.
The circular notch 33 formed on the back surface of the container cover 3
Is a screw hole that passes through the center part. As shown in the figure, the protection frame 31 has six inclined columns 3 whose protruding ends are connected by an annular portion 34.
5 is formed in a mortar shape. Reference numeral 36 denotes a display window of the confirmation light, and 37 denotes a connection hole provided in the outer ear. In the partition plate 4, reference numeral 41 denotes a mounting hole penetrating through the center of the partition plate 4, reference numeral 42 denotes a mounting base on the upper surface, reference numeral 43 denotes an annular wall protruding to the bottom surface side and having a circumferential joining surface, reference numeral 44 denotes an outer peripheral surface, and reference numeral 45 denotes an outer peripheral surface. Is an L-shaped notch formed around the periphery of the outer peripheral surface 44,
46 is an O-ring interposed in the notch 45.

In the container base 5, 51 is a circular opening formed on the bottom side of the container base 5, 52 is a screw hole through which external wiring is inserted from the left and right, and 53 and 54 are grounds provided inside and outside. Screws, 55 are bolt holes provided at four ears, and 57 is a connection hole. 4 bolt holes 5
A bolt (not shown) is inserted into 5, and the container base 5 is fixed to the ceiling surface 1 or the like. The left and right screw holes 52 are sealed by a conduit screw connection method or the like, so that crossover wiring, power supply lines, and the like are introduced into and led out of the container base 5. The connection hole 57 has a smaller diameter than the bolt hole 55 and is provided at a position corresponding to the connection hole 37 of the container cover 3.

Reference numeral 6 denotes a heat-sensitive part. The structure of the heat sensitive part 6 is shown in FIGS. 1 and 2 in an enlarged manner. Reference numeral 60 denotes a heat sensing element formed of a thermistor, 61 denotes two lead wires, 62 denotes a metal protective tube having a strength such as stainless steel, and 63 denotes a filler. Further, reference numeral 64 denotes a hollow bolt for mounting the heat-sensitive portion 6 having a through hole 65 provided in the shaft center, 66 denotes a packing, and 67 denotes an attachment portion. The heat sensing element 60 is sealed by contacting the front end inside the protection tube 62, and the sealing space is filled with the filler 63. Reference numeral 68 denotes a fastener for the heat-sensitive portion 6, 69
Is a set screw for locking the fastener 68.

The base of the protection tube 62 in which the heat sensing element 60 is sealed is inserted into the through-hole 65, and the hollow bolt 64 is formed by welding or soldering at the attachment portion 67 with the tip protruding.
To be fixed. The heat-sensitive part 6 assembled in this manner
The hollow bolt 64 is screwed into the screw hole 33 and is erected at the center of the container cover 3 as shown in FIG.

Reference numeral 7 denotes a heat collecting mechanism provided in the heat sensing section 6. Here, the heat collecting mechanism 7 is constituted by a ring-shaped circular plate 71 made of a metal having a high thermal conductivity such as aluminum, and is fixed to the vicinity of the tip of the protective tube 62 by welding. Then, the hollow bolt 64 is screwed into the screw hole 33 at the center of the container cover 3.
The heat-sensitive portion 6 erected by being screwed into is protected by a protective frame 31 so as to be mechanically protected. Reference numeral 8 denotes a printed circuit board. As shown in FIG. 7, 81 is an insertion hole penetrating near the center, 82 is a connection point of the lead wire 61, 83 is an internal wiring of the printed circuit board 8, and 84 is a hexagon made of resin. The spacer 85 is a resin screw. The hexagonal spacer 84 is provided with a screw in a leg portion, and a screw hole into which a resin screw 85 is screwed is provided in a head portion.

Reference numeral 9 denotes a terminal block fixed to the partition plate 4 with a plurality of screws 21. 90 is an insulating table having a T-shaped cross section, 9
1 is four conductive pillars, 92 is a terminal screw, 93 is a terminal screw 9
It is an insulating wall that partitions 2 etc. A conductive column 91 is provided on the insulating table 90.
Is inserted and molded with diallyl resin or the like. The partition plate 4 to which the terminal block 9 is fixed has an outer peripheral surface 44 and an annular wall 43 joined to the opening 51 of the container base 5 and the inner peripheral surface of the concave notch 32 of the container cover 3, respectively. Is fixed inside. The screw 95 is
The internal wiring 83 is connected to the conductive pillar 91.

The partition plate 4 constitutes a back cover for partitioning the container cover 3 and the container base 5, and a circuit storage room R1 for storing the printed circuit board 8 and a terminal storage room R2 for storing the external conductor terminals are vertically arranged. Separate into chambers. 21 is a screw for fixing the terminal block 9 to the partition plate 4, 22 is a screw for fixing the partition plate 4 to the container cover 3, 23 is a bolt for fixing the container cover 3 to the container base 5, and a hexagon wrench is used for the bolt 23. A hexagon socket head cap screw to be fitted is used.

An example of the assembling procedure of the heat detector of the present invention having the above-described configuration is as follows. FIG. 7 is also used to explain a part of the assembly procedure. The terminal block 9 is fixed to the partition plate 4 with screws 21 in advance, and the internal wiring 8 with some allowance is provided.
3 is connected to the printed circuit board 8 in advance. Further, the heat sensing element 60 is sealed in the inside of the protective tube 62 to which the annular disk 71 is fixed, and the filler 53 is filled therein, so that the heat sensitive portion 6 from which the lead wire 61 as shown in FIG. Assume that they are assembled.

First, the screws of the legs of the two hexagonal spacers 84 are screwed into the screw holes provided in the recess 32 of the container cover 3 and attached. Next, the lead wire 61 of the heat-sensitive portion 6 already assembled is connected to the screw hole 33 of the container cover 3.
Then, the hollow bolt 64 fitted with the packing 66 is screwed into the screw hole 33. The recessed recess 32 on the rear side by screwing
The fastener 68 is screwed onto the threaded portion of the tip of the hollow bolt 64 exposed at this point, and is then stopped by a set screw 69. In this way, the thin heat-sensitive portion 6 protruding from the mounting surface is erected at the center of the container cover 3, and the peripheral portion is surrounded by the protective frame 31 to be protected from external force and the like.

Subsequently, the lead wire 61 of the heat sensing element 60 drawn into the recess 32 of the container cover 3 is inserted into the insertion hole 81 of the printed circuit board 8, and then the printed circuit board 8 is placed on the hexagonal spacer 84. Then, the printed circuit board 8 is fixed using two resin screws 85. The core wires of the lead wires 61 are individually soldered to the fixed connection points 82 of the printed circuit board 8 through small holes penetrating the ends of the lead wires 61. The heat sensing element 60 is connected to a sensor circuit mounted on the printed circuit board 8 by soldering the core wire of the lead wire 61. After the connection of the lead wires 61, the slightly longer internal wiring 83 (the crimp terminal is provided at the tip in FIG. 3) drawn out from the printed circuit board 8 is connected to the conductive column 91 of the terminal block 9 by a screw 95. Then, the annular wall 43 is fitted into the concave notch 32, and the partition plate 4 is connected to the container cover 3 with the screws 22, and the printed circuit board 8 is housed in the chamber R1.

Thereafter, one set of container covers 3 before assembly
The container base 5 is transported to the installation place, and the container base 5 is first attached to the ceiling surface of the building using the bolt holes 55. Here, a grounding conductor (not shown) is
The inside of the container base 5 and the outside grounding screws 53 and 54 are connected. Subsequently, the external wires drawn from the screw holes 52 on both sides of the container base 5 are connected to the four terminal screws 92 of the terminal block 9. Further, the O-ring 46 is fitted into the groove formed by the notch 45 on the outer periphery of the partition plate 4 attached to the container cover 3 while slightly extending it. Then, the outer periphery 44 of the partition plate 4 is fitted into the opening 51 of the container base 5, and a hexagon wrench is tightened in accordance with the hexagon hole of the head of the bolt 23.

The container cover 3 is integrally fixed to the container base 5 by tightening a hexagon wrench, and the printed circuit board 8 and the terminal block 9 are stored in the circuit storage room R1 and the terminal storage room R2, respectively, so that the heat detector 2 is assembled. Can be Thus, the heat detector 2 composed of the container cover 3 and the container base 5 as described above.
The container 10 has a gap W and a gap depth L of all joint surfaces.
Is made in compliance with explosion-proof regulations. Therefore, even if this heat sensor 2 is installed in an explosive atmosphere like a chemical factory, the heat sensor 2
Is destroyed, or the flame generated by the internal explosion cannot be passed through the gap of the joint surface and is extinguished.

The heat-sensitive portion 6 is erected in the heat-sensitive direction so that the ceiling 1
The heat sensor 2 installed in the monitoring area always monitors the occurrence of a fire in the monitoring area. Then, when a horizontal airflow as shown in FIG. 8 flows along the ceiling surface 1, the disc 71 collects heat in the airflow and conducts the heat to the heat sensing element 60 of the heat sensing part 6. By any chance
When a fire occurs, the heat of the fire is quickly and uniformly collected by the disc 71 and transmitted to the heat sensing element 60. A sensing signal of the heat sensing element 60 that senses heat at the time of fire is output to a sensor circuit mounted on the printed circuit board 8 via the lead wire 61. Then, an input signal from the heat sensing section 6 is processed by a sensor circuit, and a fire signal is sent to a fire receiver or the like through a terminal board 9 and a crossover wiring derived from the container base 5 to perform necessary fire prevention and disaster prevention processing. Is done. At the same time, the confirmation light is turned on to illuminate the display window 36, and the alarm location in the monitoring area is confirmed.

FIGS. 10A and 10B show two modifications of the heat collecting mechanism 7 of the first embodiment, and FIGS. 10A and 10B show the respective structures. 10A and 10B, reference numeral 74 denotes a perforated disk provided with a large number of circular ventilation holes 75 through which air flows, and reference numeral 76 denotes a triangular heat collecting piece. In FIG. 10B, the lower portions of the plurality of triangular heat collecting pieces 75 are uniformly spread at an angle θ in a skirt shape, and the apex portions are protected as shown in the drawing.
The heat collecting mechanism 6 is connected to a position corresponding to the heat sensing element 60 inside the distal end of the heat collecting element 6. With the configuration as shown in FIGS. 10A and 10B, the contact area with the airflow increases, and the heat collecting effect is enhanced.

FIG. 9 is a perspective view showing the mounting operation of the heat collecting plate.
In FIG. 9A, 72 is a solder for soldering, 7 in FIG. 9B.
3 is a mounting groove. FIG. 9A shows a state in which the disk 71 is fixed to the vicinity of the tip of the heat-sensitive part by soldering. Further, in FIG. 9B in which the mounting groove 73 is provided in the protection tube 62,
1 is detachable. A detachable structure as shown in FIG. 9B is convenient because the disk 71 can be detached at any time during assembly, maintenance and inspection.

When the ascending airflow as shown by the arrow in FIG. 10A reaches the perforated disk 74, the airflow passes through the gap of the ventilation hole 75 while transmitting heat to the heat sensing element 60. . Therefore, as described above, the hot airflow having a high temperature gradient at the time of occurrence of a fire successively passes through the ventilation holes 75 to contact and transfer heat, so that the responsiveness of fire detection can be further enhanced. In particular, according to the skirt-shaped heat collecting mechanism 7 having the heat collecting pieces 76 inclined at the angle θ in FIG. 10B, the heat collecting pieces 76 face the airflow in the orthogonal direction as indicated by the dashed arrow. . Therefore, by selecting the inclination angle θ, it is possible to realize a heat sensor that has air permeability in the gap between the skirts and does not affect the directionality of the air flow.

In the above-described embodiment of the present invention, the case of a heat sensor using a heat sensing element of a thermistor has been described as an example. However, the present invention can be applied to other heat sensing elements. it can. In the embodiment, the case of the explosion-proof structure has been described. However, the present invention can be applied to an ordinary heat sensor. Further, in the modified example, the case where the circular ventilation holes are provided has been described. However, a heat collecting plate provided with ventilation holes such as a fan shape or an elliptical shape may be attached to the protective tube in multiple stages. Further, a detachable type in which a heat collecting plate is detachable from a protective tube, a rotating windmill type, or a three-dimensional type having a heat receiving surface in three axial directions may be configured. Is not necessarily limited to the embodiment.

[0028]

According to the present invention, there is provided a heat sensor having a heat sensing portion in which a heat sensing element for sensing a fire by utilizing a change in electrical characteristics due to heat is provided upright in a heat sensing direction of a mounting surface of a container cover. The heat sensing element was sealed at the tip of a metal protection tube, and a heat detector was provided with a heat collection mechanism in the protection tube. In addition, a heat detector was configured in which the heat collecting mechanism was a disk mounted in a direction perpendicular to the protective tube. In addition, a heat detector having a ventilation part in the heat collecting mechanism was configured. In addition, a heat detector in which a heat collecting mechanism was provided with a three-dimensional heat receiving surface was configured.
In addition, a heat detector having a detachable heat collecting mechanism was constructed. Furthermore, a heat detector in which a heat collecting mechanism was fixed to a protection tube was configured.

As a result, since the heat collecting mechanism is provided in the protruding heat sensitive portion, the heat collecting effect can be enhanced. In addition, since the heat collecting plate with a large heat receiving surface transfers the heat of the fire to the heat sensing element inside the protective tube while collecting heat, the unevenness of the heat of the hot air flow in the event of a fire is compensated, and the detection sensitivity and response of the heat sensing element Performance can be improved. In particular, according to the heat collecting mechanism provided with the ventilation section and having the heat receiving surface in the three axial directions, not only is the heat collecting direction independent of the direction of the air flow, but also the heat collecting operation follows a change in the hot air flow having a large temperature gradient. The responsiveness of the sensing element can be further improved.

Therefore, according to the present invention, it is possible to improve the detection sensitivity of the heat sensing element with a simple configuration and provide a highly accurate heat sensor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a heat-sensitive unit according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view illustrating a configuration in the vicinity of a heat-sensitive portion according to the first embodiment.

FIG. 3 is a cross-sectional view of the heat sensor according to the first embodiment.

FIG. 4 is a side view of the heat sensor according to the first embodiment.

FIG. 5 is a bottom view of the heat sensor according to the first embodiment.

FIG. 6 is a top view of the terminal block according to the first embodiment.

FIG. 7 is a perspective view showing an assembling operation of the first embodiment.

FIG. 8 is a perspective view illustrating an airflow sensing operation.

FIG. 9 is a perspective view showing an attaching operation of the heat collecting plate.

FIG. 10 is a perspective view illustrating an airflow sensing operation according to a modification.

FIG. 11 is a cross-sectional view of a conventional sensor.

FIG. 12 is a cross-sectional view of an element unit of a conventional sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceiling surface 2 Heat detector 3 Container cover 4 Partition plate 5 Container base 6 Heat sensitive part 7 Heat collection mechanism 8 Printed circuit board 9 Terminal block 10 Container 31 Protective frame 36 Display window 60 Heat sensing element 61 Lead wire 62 Protective tube 63 Filler 64 Hollow bolt 65 Through hole 66 Packing 67 Flanged part 68 Fastener 69 Set screw 71 Disk 72 Solder 73 Mounting groove 74 Open hole disk 75 Vent hole 76 Heat collecting piece R1 Circuit storage room R2 Terminal storage room θ Incline angle

Claims (6)

[Claims] 1. A heat sensor having a heat-sensing portion in which a heat-sensing element for sensing a fire by utilizing a change in electrical characteristics due to heat is provided upright in a heat sensing direction of a mounting surface of a container cover. A heat sensor, wherein the element is sealed in a tip portion of a metal protection tube, and a heat collection mechanism is provided in the protection tube. 2. The heat collecting mechanism according to claim 1, wherein the heat collecting mechanism comprises a disk mounted in a direction perpendicular to the protection tube.
The heat sensor as described. 3. The heat sensor according to claim 1, wherein a ventilation section is provided in the heat collecting mechanism. 4. The heat sensor according to claim 1, wherein the heat collecting mechanism is provided with a three-dimensional heat receiving surface. 5. The heat sensor according to claim 1, wherein said heat collecting mechanism is detachable. 6. The heat sensor according to claim 1, wherein the heat collecting mechanism is fixed to a protection tube.