JP3740964B2 - Fire detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fire detector that senses heat generated by a fire using heat sensing means such as a thermistor.
[0002]
[Prior art]
As a first conventional fire detector having a waterproof structure related to the present invention, a circuit board on which electrical components are mounted is arranged in an enclosure in the detector body, and the inside of the enclosure is filled with a filler such as urethane resin. Some circuit boards and their electrical components are waterproof. Such a conventional fire detector includes a sensor circuit having a circuit board on which electrical components are mounted, a sensor body having a peripheral wall forming a circuit storage space for storing the circuit board, and a circuit storage space filled with the circuit. And a filler that protects the sensing circuit from moisture and mechanical damage. In such a fire sensor, the outer surface of the electrical component on the circuit board is covered with the filler, for example, by direct contact with the filler.
[0003]
Further, as a second conventional fire detector having a waterproof structure, a circuit storage space for storing a circuit board on which an electrical component is mounted is formed by a peripheral wall of the sensor body, and a component such as a lid member is formed on the peripheral wall. There is one that secures waterproofness by applying and adhering with a UV curable filler to seal the joint and forming a sealed space around the sensing circuit.
[0004]
[Problems to be solved by the invention]
In the first conventional fire detector described above, when an electrical component such as an electrolytic capacitor or a reed switch is provided, since the filler directly contacts the outer surface, the electrical characteristics as the electrical component change. In such a case, the performance of the fire detector may be adversely affected.
[0005]
In the second conventional fire detector described above, since the filler is not in contact with an electrical component that is inconvenient for the filler to directly contact the outer surface of an electrolytic capacitor or a reed switch, Does not adversely affect the performance of the fire detector. However, it is necessary to apply an ultraviolet curable filler selectively to a necessary portion of the joint between the peripheral wall and the lid member and cure it by irradiation with ultraviolet rays, which requires a large number of steps. In addition, since the internal shape of the fire detector is complicated, it is difficult and troublesome to apply the filler.
[0006]
Accordingly, the present invention has been made to solve the above-described problems, and its purpose is a simple and reliable structure that is easy to assemble, and is inconvenient for direct contact of the filler with the outer surface. It is an object of the present invention to provide a fire sensor that can be easily waterproofed without directly contacting a filler with a component.
[0007]
[Means for Solving the Problems]
(1) A fire detector according to the present invention includes a sensing circuit having a circuit board on which an electrical component including parts that are inconvenient to cover the outer surface is mounted, and a sensing having a peripheral wall that forms a circuit housing space for housing the circuit board A fire detector comprising a main body and a filler filled in the circuit housing space to protect the sensing circuit, provided in the circuit housing space and covering the outer surface in cooperation with the circuit board In this case, a partition wall is formed that surrounds a part that is inconvenient, and forms a space not filled with a filler around the part that is inconvenient to cover the outer surface.
[0008]
(2) The partition may be an enclosure that extends integrally from the sensor body and contacts the circuit board.
[0009]
(3) The peripheral wall may be provided with a cover for closing the open end of the peripheral wall, and the partition may be an enclosure that extends integrally from the cover and contacts the circuit board.
[0010]
(4) The filler may be a urethane resin, a silicone resin or an epoxy resin.
[0011]
(5) A component that is inconvenient to cover the outer surface may be at least one of an electrolytic capacitor and a reed switch.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a configuration of a fire detector according to a first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view taken along line AA in FIG. 1 and 2, the fire sensor of the present invention includes a sensor body 1, a sensor circuit 2 provided in the sensor body 1, and a filler that covers and protects the sensor circuit 2 in the sensor body 1. 3 is provided.
[0013]
The sensor body 1 includes a base 4 that is attached to the ceiling with a fixing screw (not shown), and a case 5 that is detachably attached to the base 4 and forms the sensor body 1 in cooperation with the base 4. . A peripheral wall 6 having an open end that extends integrally from the center of the inner surface of the case 5 and extending toward the base 4 circulates, and a circuit storage space 7 for storing the sensing circuit 2 is formed inside the peripheral wall 6. A support member 8 is provided in the circuit storage space 7 to support the sensing circuit 2 at a predetermined position in the circuit storage space 7. In the circuit storage space 7, a space 10 is formed on the inner side for accommodating a component 9 that extends integrally from the inner surface of the case 5 toward the base 4 and that is difficult to cover the outer surface, which will be described later. A partition wall 11 is provided.
[0014]
The sensing circuit 2 includes a circuit board 14 and electrical components such as an electrolytic capacitor, a reed switch, a thermistor 16 and a lead wire 17 mounted on the circuit board 14. Among these electrical components, the electrolytic capacitor is not described in detail, but a pressure valve for venting the inside is provided, and in order to maintain the original function of the electrolytic capacitor, a predetermined space is provided around the pressure valve. It is necessary to provide it. Although the reed switch will not be described in detail, if the outside is covered with a glass tube and the glass tube part is covered with the filler 3, when the filler 3 is cured, the outside temperature changes after curing, etc. Due to compression, expansion, etc., stress is applied to the glass tube portion, and the glass tube may crack and may not have its original function. As described above, in the electrolytic capacitor and the reed switch, when the outer surface is directly covered by the filler 3 coming into contact with the outer surface, the electrical characteristics may be affected. The performance may be adversely affected, and in this respect, electrolytic capacitors, reed switches, and the like are components 9 that are inconvenient to cover the outer surface.
[0015]
According to the present invention, the component 9 that is inconvenient to cover the outer surface can be at least one of an electrolytic capacitor and a reed switch. The sensing circuit 2 has a circuit board 14 supported and supported by a support member 8 in a circuit housing space 7 in the sensor body 1. Of the electrical components of the sensing circuit 2, the thermistor 16 is electrically connected and fixed to the sensing circuit 2 on the circuit board 14 and mechanically connected, and penetrates through the center hole 18 of the case 5 to the bottom surface. And is protected by a protector 19. Of the electrical components of the sensing circuit 2, the lead wire 17 extends upward from the circuit board 14 through the base 4 and can be connected to a circuit on the installation surface (not shown) such as a ceiling. . The first embodiment of the present invention is described as a fire detector that detects heat generated by a fire using the heat detection means of the thermistor 16, but may be configured as a smoke / flame detector or the like. It is.
[0016]
A gap 20 is formed between the circuit board 14 supported at a predetermined position in the circuit storage space 7 by the support member 8 and the peripheral wall 6, and the circuit storage space 7 is left above and below the circuit board 14. Yes. In such a circuit storage space 7, a filler 3 such as urethane resin, silicone resin or epoxy resin is filled from above the circuit storage space 7, and is in direct contact except for a portion of the thermistor 16 and the lead wire 17. The sensor circuit 2 is completely covered and protected. However, the component 9 that is inconvenient to cover the outer surface such as an electrolytic capacitor and a reed switch is provided between the circuit board 14 and the case 5 and extends integrally from the case 5 toward the circuit board 14. It is surrounded by a cylindrical partition wall 11 in contact with the circuit board 14 at the tip. Accordingly, since the partition wall 11 closes the internal space in cooperation with the circuit board 14, the filler 3 in the circuit storage space 7 cannot enter the space 10 in the partition wall 11 and covers the outer surface. The inconvenient part 9 is surrounded by a space 10 that is not filled with the filler 3. Although not shown, a cover for closing the open end of the peripheral wall 6 that forms the circuit housing space 7 may be provided. In this case, it is desirable that the cover be engaged with the open end of the peripheral wall 6 at the peripheral edge thereof so as not to be displaced and have a hole for allowing the lead wire 17 to pass therethrough.
[0017]
According to the fire detector having such a configuration, the filler 3 is injected into the circuit storage space 7 from the upper side of the circuit storage space 7 without affecting the assembling work with a structure in which the simple partition wall 11 is provided. Therefore, the assembling work is easy, and the waterproof treatment of the sensing circuit 2 can be easily performed without directly contacting the filler 3 with the component 9 which is inconvenient to cover the outer surface. Further, it is not necessary to use an ultraviolet curable filler as the filler 3. And since the filling operation | work of the filler 3 only needs once, workability | operativity is good and can reduce the number of manufacturing processes and cost.
[0018]
Embodiment 2. FIG.
FIG. 3 is a sectional view showing the structure of a fire detector according to the second embodiment of the present invention. The fire sensor includes a cover 34 that closes an open end of a peripheral wall 33 that forms a circuit housing space 32 in the sensor body 1. The cover 34 is engaged with the open end of the peripheral wall 33 at its peripheral edge portion 35 so as not to be displaced, and has a hole 36 through which the lead wire 17 is passed. A sensing circuit 2 in which a circuit board 37 is supported at a predetermined position by a support member 8 is provided in the circuit storage space 32. From the inner surface of the cover 34, a cylinder surrounding a component 9 that is inconvenient to cover the outer surface. A shaped partition wall 38 extends integrally toward the circuit board 37 and is in contact with the circuit board 37 at its tip. Further, the component 9 that is inconvenient to cover the outer surface is provided on the upper surface of the circuit board 37 in FIG. 3, that is, the side facing the cover 34. Accordingly, the component 9 that is inconvenient to cover the outer surface is accommodated in the space 39 surrounded by the cover 34, the circuit board 37, and the partition wall 38 without being directly contacted by the filler 3. The other structure is the same as that of the fire detector of FIG. 1 and FIG.
[0019]
According to the fire detector having such a structure, the cover 34 is simply provided with the partition wall 38 and does not affect the assembling work, and is filled from the hole 36 through which the lead wire 17 provided in the cover 34 is passed. Since the agent 3 is simply injected into the circuit storage space 32, the assembling work is easy, and the sensing circuit 2 is easily waterproofed without directly contacting the filler 3 with the component 9 that is inconvenient to cover the outer surface. Can be done. Further, it is not necessary to use an ultraviolet curable filler as the filler 3. And since the filling operation | work of the filler 3 only needs once, workability | operativity is good and can reduce the number of manufacturing processes and cost. Further, an injection port (not shown) may be provided in the cover 34 to inject the filler 3 into the circuit storage space 7.
[0020]
【The invention's effect】
(1) As is clear from the above description, the fire detector of the present invention includes a sensing circuit having a circuit board on which an electrical component including a component that is inconvenient to cover the outer surface is mounted, and a circuit housing that houses the circuit board. A fire sensor comprising a sensor body having a peripheral wall forming a space and a filler that is filled in the circuit housing space to protect the sensing circuit, is provided in the circuit housing space and cooperates with the circuit board. It is provided with a partition wall that encloses a part that is inconvenient to cover the outer surface and forms an unfilled space around the part that is inconvenient to cover the outer surface. (2) The partition may be an enclosure that extends integrally from the sensor body and contacts the circuit board. Further, (4) the filler may be a urethane resin, a silicone resin or an epoxy resin, and (5) the part which is inconvenient to cover the outer surface may be at least one of an electrolytic capacitor and a reed switch.
[0021]
Therefore, the structure with a simple partition is provided, and the assembly work is easy because the filler is only injected into the circuit storage space without affecting the assembly work, and the filler comes into direct contact with the outer surface. Thus, the sensing circuit can be easily waterproofed without directly contacting the filler with the inconvenient electrical component. Further, it is not necessary to use an ultraviolet curable filler as the filler. And since the filling operation | work of a filler is sufficient once, workability | operativity is good and can reduce the number of manufacturing processes and cost.
[0022]
(3) If the peripheral wall is provided with a cover that closes the open end of the peripheral wall and the partition wall extends integrally from the cover and is in contact with the circuit board, it has a structure in which a simple partition wall is provided on the cover, which affects the assembly work. Without applying the filler, the waterproof treatment of the sensing circuit can be easily performed without bringing the filler into direct contact with an electrical component that is inconvenient for the filler to come into direct contact with the outer surface.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a fire detector according to Embodiment 1 of the present invention.
FIG. 2 is a partial cross-sectional view taken along line AA in FIG.
FIG. 3 is a cross-sectional view showing a fire detector according to Embodiment 2 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sensor main body, 2 Sensing circuit, 3 Filler, 6, 33 Perimeter wall, 7, 32 Circuit storage space, 9 Parts where it is inconvenient to cover the outer surface, 9, 16, 17 Electrical parts, 10, 39 With filler Unfilled space, 11, 38 Bulkhead, 14, 37 Circuit board, 34 Cover.

Claims (1)

A sensing circuit having a circuit board on which electrical components including parts that are inconvenient to cover the outer surface are mounted, a sensor body having a peripheral wall that forms a circuit housing space for housing the circuit board, and the circuit housing space a filler filled to protect the sensing circuit provided in the circuit housing space, in cooperation with the circuit board, surrounds the inconvenience parts that cover the outer surface, to cover the outer surface In a fire detector comprising a partition wall that forms a space not filled with the above-mentioned filler around an inconvenient part ,
The fire detector, wherein the peripheral wall includes a cover that closes an open end of the peripheral wall, and the partition wall is an enclosure that extends integrally from the cover and contacts the circuit board .

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