JP5606123B2 - Photoelectric smoke detector - Google Patents

Description

  The present invention relates to a smoke detector insect screen for detecting a fire and a photoelectric smoke detector.

  The conventional smoke detector flows in smoke from outside, blocks light from outside, forms a dark box, a light emitting unit for irradiating light inside the dark box, and flows from the outside A light receiving unit that receives light scattered by smoke, a smoke detecting unit in which optical axes of the light emitting unit and the light receiving unit intersect at a predetermined angle, and a fire determination unit that determines a fire based on an output signal of the smoke detecting unit And an insect screen that surrounds the outer periphery of the labyrinth wall and prevents insects from entering from the outside (see, for example, Patent Document 1).

  In the smoke detector, normally, the light emitted from the light emitting unit does not enter the light receiving unit (when monitoring a fire), but if smoke flows into the dark box due to a fire, the light from the light emitting unit collides with the smoke. It becomes scattered light and enters the light receiving part. And if the said light-receiving part sends out a light reception output to a fire discrimination | determination part, this fire discrimination | determination part will judge fire.

JP-A-9-231485

  Steam generated in a bath or the like has a particle size larger than that of smoke, for example, 10 μm in diameter, about 10 times larger than the particle size of smoke, and its mass is about 1000 times that of smoke. , May rise inside the room and flow into the smoke detector. Then, since this steam collides with the light of the light emitting part and generates scattered light, the light receiving part that has received the scattered light outputs it to the fire determining part. For this reason, the fire determination unit determines a fire regardless of the fact that no smoke (fire) is generated.

  In view of the above circumstances, an object of the present invention is to prevent malfunction due to steam.

The present invention includes a labyrinth wall that allows smoke to flow in from the outside and blocks light from the outside to form a dark box, a light emitting unit that irradiates light inside the dark box, and scattered light from smoke that flows in from the outside A light receiving unit that receives light, a smoke detecting unit in which optical axes of the light emitting unit and the light receiving unit intersect at a predetermined angle, a fire determining unit that determines a fire based on an output signal of the smoke detecting unit, and the labyrinth In the photoelectric smoke detector, which surrounds the outer periphery of the wall and prevents insects from entering from the outside, the smoke detector is on the upper side of the dark box, and the insect screen has a belt shape when placed over the labyrinth walls of the black box is a cylindrical shape not covered with the outer periphery of said labyrinth wall comprises a nonporous portion having no pore at a position opposed to the smoke detection portion, the lower side of the dark box Fine pores at positions facing the portion without the smoke detector. Includes a section, steam that has entered from the smoke inlet section formed by the pore portion in the dark box, without rising in the dark box, characterized in that it is discharged advanced unit outside of it.

The present invention has a labyrinth wall that allows smoke to flow in from the outside and blocks light from the outside to form a dark box, a light emitting unit that irradiates light inside the dark box, and reduced light due to smoke that flows from the outside A light receiving unit that receives light, a smoke detecting unit in which optical axes of the light emitting unit and the light receiving unit are located on the same straight line, a fire determination unit that determines a fire based on an output signal of the light receiving unit, and the labyrinth wall In the photoelectric smoke detector comprising an insect net that surrounds the outer periphery of the insect and prevents insects from entering from the outside, the smoke detector is on the upper side of the dark box, and the insect net has a belt shape, when placed over the labyrinth walls of the black box is a cylindrical shape not covered with the outer periphery of said labyrinth wall comprises a nonporous portion having no pore at a position opposed to the smoke detection portion, wherein the lower side of the dark box A pore with a pore at a position facing the part without the smoke detector For example, steam that has entered from the smoke inlet section formed by the pore portion in the dark box, without rising in the dark box, characterized in that it is directly discharged advanced unit outside of.

In the insect net of the present invention, the pores are provided symmetrically at both ends of the band-like width direction, and when attached to the photoelectric smoke sensor, the pores on the upper end side It is a position which does not oppose the opening window of a type | formula smoke sensor, The said smoke inflow part is not formed, but only the pore part of a lower end side forms the said smoke inflow part, It is characterized by the above-mentioned .

  Since the present invention is configured as described above, smoke and steam flow into the smoke inflow section below the smoke detection section, and the smoke rises to reach the smoke detection section, but steam is heavier than smoke. It flows in the horizontal direction and cannot reach the smoke detector. Therefore, since the steam does not enter the irradiation range of the light emitting part of the smoke detector, it is possible to prevent malfunction of the smoke detector due to steam.

It is a figure which shows embodiment of this invention and is a front view which shows an insect screen. It is the perspective view which made the insect repellent net cylindrical. It is a front view which shows a use condition. It is a cross-sectional view which shows the inside of the smoke detector part of FIG. It is a partial longitudinal cross-sectional enlarged view which shows a use condition. It is a longitudinal cross-sectional view which shows the flow in the dark box of smoke. It is a longitudinal cross-sectional view which shows the flow in the dark box of steam.

  The present inventor said that when smoke and steam enter the dark box through the gap between the labyrinth walls, the smoke rises in the dark box, but steam heavier than smoke does not rise and goes straight in the horizontal direction. noticed. Therefore, the inside of the dark box is separated into upper and lower parts, the lower part of the smoke detection part (the tip side of the labyrinth wall) is used as the smoke inflow part, and the smoke detection part disposed above the smoke inflow part by the smoke inflow restriction means The direct smoke did not enter. For this reason, smoke and steam only enter the smoke inflow part, but even if the steam enters the dark box, it does not rise, so it cannot reach the smoke detection part. The present invention has been made based on the above findings.

  An embodiment of the present invention will be described with reference to FIGS. A labyrinth wall 3 is erected in a cylindrical shape on the optical stage 2 of the photoelectric smoke detector 1. The labyrinth wall 3 is a wall formed by arranging pillar portions 3p having a “<” shape or a “J” shape in a plan view on the optical bench 2 at an arbitrary interval. Although it flows into the inside through the gap of 3p, outside light does not enter the inside because it cannot pass through the gap.

  A tip 3 a of the labyrinth wall 3 is closed by a canopy 4, and the inside of the labyrinth wall 3 is a dark room, which is a so-called dark box 5. The dark box 5 is a space into which smoke flows but external light does not enter.

  The optical bench 2 is provided with a light emitting unit 7 that emits pulses in the dark box 5 and a light receiving unit 8 that receives scattered light generated by the smoke particles S flowing from the outside. In the dark box 5, the optical axes L1 and L2 of the light emitting element of the light emitting unit 7 and the light receiving element of the light receiving unit 8 intersect at a predetermined intersection angle on the same horizontal plane. 120 degrees.

  The light emitting element and the light receiving element are mounted on the circuit board 12. A light shielding wall 6 is provided in the vicinity of the intersection of the two optical axes L1 and L2. The wall 6 prevents light from the light emitting unit 7 from directly entering the light receiving unit 8.

  The inside of the dark box 5 is separated into upper and lower sides, and the upper side thereof, that is, the fixed end side (circuit board 12 side) of the labyrinth wall 3 is a smoke detecting section 10, and the lower side thereof, that is, the labyrinth wall 3. The tip 3 a side (the side opposite to the circuit board 12) is a smoke inflow portion 11. The smoke detector 10 is a portion where the optical axes L1 and L2 of the light emitter 7 and the light receiver 8 are located and detects smoke, and the smoke inlet 11 is below the optical axes L1 and L2. It is located on the side of the labyrinth wall 3 (on the side of the tip 3a) where smoke and steam come in and out.

  The outer periphery of the labyrinth wall 3 is surrounded by an insect screen 15. This insect net 15 is formed in a band shape (rectangular shape), and hook-shaped locking portions 16 that are engaged with each other are provided at both ends (both end portions) in the longitudinal direction. A non-hole portion 15a having a width X is provided at the center in the width direction of the insect repellent net 15, and the upper end portion and the lower end portion on both sides thereof are pore portions 15b having a width W having a large number of pores 15p. ing. Since both the pores 15b and 15b are formed symmetrically with respect to the central axis C, the pore 15b on the lower side can be smoked as designed even if it is mounted on the labyrinth wall 3 upside down. Opposite the inflow part 11. For this reason, even if the top and bottom of the insect screen 15 are reversed, no functional failure occurs.

  This insect net 15 is formed in a cylindrical shape to engage and fix the locking portions 16 and 16 (see FIG. 2), and is put on the labyrinth wall 3. The non-hole portion 15a is formed on the upper side of the labyrinth wall 3. Opposite to the portion forming the smoke detecting section 10, the fine pore portion 15b is opposed to the portion forming the smoke inflow portion 11 on the lower side of the labyrinth wall 3, and the fine pore portion 15b is It is located at a height that avoids the smoke detector 10. Accordingly, since the outer peripheral portion of the smoke detector 10 is closed, the intrusion of smoke is blocked and the smoke inflow portion 11 is opened, so that the smoke flows into the dark box 5 only from the smoke inflow portion 11.

  The smoke detector 1 is provided with a fire discriminating unit (not shown) that determines a fire based on the output signal of the smoke detecting unit 10. The optical bench 2, the labyrinth wall 3, the insect net 15 and the like are built in the housing 20. The housing 20 includes a cover 21 having an opening window 22 so as to face the smoke inflow portion 11.

Next, the operation of this embodiment will be described.
"When a fire occurs"
When smoke particles S are generated by a fire, the smoke particles S rise toward the ceiling surface to which the photoelectric smoke detector 1 is attached and flow along the ceiling surface. Then, the smoke particles S pass through the insect screen 15 and the lower side of the labyrinth wall 3 and flow into the smoke inflow portion 11 in the dark box 5.

  Since the smoke particles S in the smoke inflow part 11 are light, a part of the smoke particles S rises in the dark box 5 in the direction of arrow A10 and enters the smoke detection part 10, and the light emission part 7 Collides with light to generate scattered light (see FIG. 6). The scattered light is received by the light receiving unit 8, and the light receiving unit 8 sends an output signal to the fire determining unit, so that the fire determining unit determines a fire.

"Normal"
When steam Y is generated in a bath or the like, the steam Y rises toward the ceiling and tries to enter the photoelectric smoke detector 1.

The steam Y is insect screen 15, but flows into the smoke inlet section 11 of the dark box 5 through the lower labyrinth wall 3, the steam Y is rather heavy than smoke particles S that occur during a fire, dark box 5 Without moving up, the air travels in the horizontal direction A11 and is discharged outside the container (see FIG. 7).

  Therefore, the steam Y does not reach the smoke detector 10 and therefore does not collide with the optical axis L1 of the light emitting unit 7. Therefore, even if steam enters the dark box, the light receiving unit 8 does not send an output signal to the fire determining unit, so that the fire determining unit does not determine a fire. Therefore, malfunction due to steam can be prevented.

  The embodiment of the present invention is not limited to the above. For example, instead of intersecting the optical axes of the light emitting unit and the light receiving unit at a predetermined angle, the optical axes of the light emitting unit and the light receiving unit are the same. It is good also as a structure which is located on a straight line and judges that it is a fire when the light-receiving amount of the light-receiving part 8 reduces only a predetermined ratio.

DESCRIPTION OF SYMBOLS 1 Optical smoke detector 2 Optical stand 3 Labyrinth wall 5 Dark box 7 Light emission part 8 Light reception part 10 Smoke detection part 11 Smoke inflow part 15 Insect net 15a Non-hole part 15b Fine hole part 15p Fine hole 20 Case 21 Cover L1 Optical axis L2 Optical axis S Smoke Y Steam

Claims (3)

A labyrinth wall that allows smoke to flow from the outside and blocks light from the outside to form a dark box, a light emitting unit that irradiates light inside the dark box, and a light receiving unit that receives scattered light from the smoke that flows from the outside A smoke detection unit in which optical axes of the light emitting unit and the light receiving unit intersect at a predetermined angle, a fire determination unit that determines a fire based on an output signal of the smoke detection unit, and an outer periphery of the labyrinth wall In a photoelectric smoke detector with an enclosure and an insect screen that prevents insects from entering the outside,
The smoke detector is on the upper side of the dark box,
The insect screen is of a beltlike shape, when placed over the labyrinth walls of the black box is a cylindrical shape not covered with the outer periphery of said labyrinth wall, the imperforate portion having no pore at a position opposed to the smoke detection portion Comprising a pore portion having a pore at a position facing a portion where the smoke detection portion on the lower side of the dark box is not present,
The photoelectric smoke detector is characterized in that the steam that has entered the dark box from the smoke inflow part formed by the pores proceeds as it is and does not rise in the dark box and is discharged to the outside . A labyrinth wall that blocks smoke from the outside and forms a dark box, a light emitting unit that emits light to the inside of the dark box, and a light receiving unit that receives reduced light due to the smoke that flows from the outside A smoke detecting unit in which optical axes of the light emitting unit and the light receiving unit are located on the same straight line, a fire determining unit that determines a fire based on an output signal of the light receiving unit, and an outer periphery of the labyrinth wall In a photoelectric smoke detector equipped with an insect screen that prevents insects from entering from the outside,
The smoke detector is on the upper side of the dark box,
The insect screen is of a beltlike shape, when placed over the labyrinth walls of the black box is a cylindrical shape not covered with the outer periphery of said labyrinth wall, the imperforate portion having no pore at a position opposed to the smoke detection portion Comprising a pore portion having a pore at a position facing a portion where the smoke detection portion on the lower side of the dark box is not present,
The photoelectric smoke detector is characterized in that the steam that has entered the dark box from the smoke inflow part formed by the pores proceeds as it is and does not rise in the dark box and is discharged to the outside . In the insect net, the pores are provided symmetrically at both ends in the band-like width direction, and when attached to the photoelectric smoke detector, the pores on the upper end side are the photoelectric smoke detectors. 3. The photoelectric smoke according to claim 1, wherein the photoelectric smoke is a position that does not face the opening window of the vessel, does not form the smoke inflow portion, and only the pore portion on the lower end side forms the smoke inflow portion. sensor.

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