JP2022191385A - fire detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire detection device in which gas inflow performance and a detection accuracy of the fire detection device can be maintained.

SOLUTION: The fire detection device includes: inflow space which is provided in the inside of the fire detection device; detection space which is provided closer to a position on an installation surface side than the inflow space in the inside of fire detection device; an outer cover and an inner cover for suppressing incidence of disturbance light to the detection space from the outside of the fire detection device; a first light emission part, a second light emission part and a light reception part which are provided in the inner cover; and a light-reception suppression part 110 which is provided in the inner cover. The light-reception suppression part 110 includes a plurality of light shielding ribs which are installed side by side while spacing each other along an incident direction of detection light. Each of third insertion ports 85a of the light shielding ribs is formed smaller toward a front side of the incident direction.

SELECTED DRAWING: Figure 6

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to fire detection devices.

Conventionally, a technique has been proposed for a smoke sensor that detects a fire in a monitoring area, and detects scattered light caused by the smoke by allowing smoke to flow into the smoke sensor. In this technique, for example, a housing, an inflow space provided inside the housing for allowing an external gas to flow in through an opening formed in the housing, and an interior of the housing A detection space provided in a detection space provided in parallel with the inflow space along the installation surface, a light emitting unit and a light receiving unit provided in the detection space, and a labyrinth provided inside the housing. and a labyrinth having a plurality of labyrinth members surrounding a detection space at intervals (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2006-267128

However, in the above conventional technology, as described above, the inflow space and the detection space are arranged side by side along the installation surface. Since there is a possibility that the ambient light may directly enter the detection space through the ambient light, it may become difficult to maintain the detection accuracy of a fire detection device such as a smoke sensor due to ambient light. Therefore, there is room for improvement from the viewpoint of maintaining the inflow of gas and the detection accuracy of the fire detection device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fire detection device capable of maintaining gas inflow and detection accuracy of the fire detection device.

In order to solve the above-described problems and achieve the object, the fire detection device according to claim 1 is a fire detection device that is attached to the installation surface of an installation target, and is a fire detection device for detecting a fire in a monitoring area. A detection device, which is an inflow space provided inside the fire detection device and into which gas from the outside of the fire detection device can flow; a detection space for detecting a detection target; Incidence suppressing means for suppressing ambient light from entering the detection space from the outside of the fire detection device, wherein the gas can flow into the detection space through the inflow space, and the ambient light and an incident suppression means for partitioning the inflow space and the detection space so that it is possible to suppress direct incidence of the light into the detection space through the inflow space; Light-emitting means for irradiating detection light into the detection space; and light-receiving means provided inside the incident suppressing means, wherein the detection light emitted from the light-emitting means is emitted into the detection space. light receiving means for receiving scattered light generated by being scattered by the detection target; and light receiving suppressing means provided inside the incident suppressing means, wherein the disturbance light incident on the detection space is received by the light receiving means. a light receiving suppressing means for suppressing the light to be received by the detection light, wherein the light receiving suppressing means is a plurality of light shielding ribs arranged side by side at intervals along the incident direction of the detection light, A plurality of light shielding ribs each having an insertion opening for inserting the detection light is provided, and the insertion openings of the plurality of light shielding ribs are made smaller toward the front side in the incident direction.

According to the fire detection device of claim 1, the detection space for detecting the detection target, the detection space provided in the interior of the fire detection device at a position closer to the installation surface than the inflow space. , an incident suppressing means for suppressing disturbance light from entering the detection space from the outside of the fire detection device, wherein the gas can flow into the detection space through the inflow space, and the disturbance light can flow into the inflow space; and an incident suppressing means that partitions the inflow space and the detection space so as to be able to suppress direct incidence into the detection space via the conventional technology (the detection space and the inflow space are on the installation surface technology installed side by side), it is possible to suppress the direct incidence of ambient light into the detection space through the inflow space while allowing the gas to reliably flow into the detection space. It becomes possible to maintain the detection accuracy of the fire detection device.
Further, since the light reception suppressing means is provided inside the incident suppression means and is for suppressing the disturbance light incident on the detection space from being received by the light receiving means, the detection is performed by the light reception suppressing means. It is possible to prevent the light-receiving means from receiving disturbance light that has entered the space, and it becomes even easier to maintain the detection accuracy of the fire detection device.
In addition, since the insertion openings of the plurality of light shielding ribs are made smaller toward the near side in the incident direction, the light through these insertion openings is smaller than when the insertion openings of the plurality of light blocking ribs are made larger toward the near side in the incident direction. It is possible to suppress the detection light that has entered through these insertion openings from exiting to the outside, making it even easier to maintain the detection accuracy of the fire detection device.

It is a side view which shows the attachment condition of the fire detection apparatus which concerns on embodiment. It is a bottom view which shows the fire detection apparatus of the state which removed the mounting base. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2; It is a bottom view which shows a detection part main body. FIG. 4 is a diagram showing a situation in which disturbance light is incident on the detection space from the outside of the fire detection device through the inflow space, and is a diagram showing the region corresponding to FIG. 3 ; 5 is an enlarged view of a region of a light reception suppressing portion in FIG. 4; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a fire detection device according to the present invention will be described in detail below with reference to the drawings. First, [I] the basic concept of the embodiment will be described, then [II] the specific contents of the embodiment will be described, and finally [III] modifications of the embodiment will be described. However, the present invention is not limited by the embodiment.

[I] Basic concept of the embodiment First, the basic concept of the embodiment will be described. The embodiment is generally a fire detection device attached to an installation surface of an installation object, and relates to a fire detection device for detecting fire in a monitoring area.

Here, the "fire detection device" is a device that optically detects and reports a fire in the monitored area, and is a concept that includes, for example, an optical fire detector and a fire alarm. . In addition, "installation object" is the object on which the fire detection device is installed, and is a concept that includes, for example, the ceiling and walls of a building. In addition, although the specific structure and type of "building" is arbitrary, for example, the concept includes detached houses, collective housing such as apartments and condominiums, office buildings, event facilities, commercial facilities, public facilities, etc. is. A "monitored area" is an area to be monitored, and is a concept including, for example, an area inside a building, an area outside the building, and the like. In addition, "notify" is a concept including, for example, outputting predetermined information to an external device, displaying or outputting predetermined information via output means (display means or audio output means), etc. be. Hereinafter, in the embodiments, the "fire detection device" is the "optical fire detector", the "installation object" is the "ceiling of the office building", and the "monitoring area" is the "office building A case of "internal area" will be described.

[II] Specific contents of the embodiment Next, specific contents of the embodiment will be described.

(composition)
First, the configuration of the fire detection device according to the embodiment will be described. FIG. 1 is a side view showing how the fire detection device according to the embodiment is mounted. FIG. 2 is a bottom view showing the fire detection device with a mounting base, which will be described later, removed. 3 is a cross-sectional view taken along line AA of FIG. 2. FIG. In the following description, the X direction in FIG. 1 is the horizontal direction of the fire detection device (+X direction is the left direction of the fire detection device, -X direction is the right direction of the fire detection device), and the Y direction in FIG. 2 is the fire detection device. The front and back direction (+Y direction is the front direction of the fire detection device, -Y direction is the rear direction of the fire detection device), the Z direction in FIG. The direction is referred to as the downward direction of the fire detector). Further, with reference to the center position of the detection space described later in FIG. 3, the direction away from the detection space described later will be referred to as "outside", and the direction approaching the detection space described later will be referred to as "inside".

The fire detection device 1 is a device that detects and reports a detection target (for example, smoke) contained in gas. This fire detection device 1 is installed indoors in a building on an installation surface 2 on the lower surface of the ceiling of the building. As shown in FIGS. It has an inflow space 40 , an insect screen 50 , a detection space 60 , a detection section cover 70 , a detection section main body 80 , a terminal board 90 and a substrate 100 .

(Configuration - Mounting base)
Returning to FIG. 1 , the mounting base 10 is mounting means for mounting the outer cover 20 on the installation surface 2 . The mounting base 10 is configured using, for example, a known mounting base for a fire detection device (for example, a substantially plate-shaped mounting base made of resin) or the like, and as shown in FIG. It is fixed with a fixture or the like.

(Configuration - outer cover)
The outer cover 20 is an incident suppression means for suppressing the incidence of ambient light into the detection space 60, and includes the inner cover 30, the inflow space 40, the insect screen 50, the detection space 60, the detection unit cover 70, and the detection unit. It is a cover that covers the main body 80 , the terminal board 90 and the substrate 100 . Here, the "disturbance light" is, for example, light other than the first detection light described later and the second detection light described later among the lights incident on the detection space 60, and specifically includes sunlight, lighting, and the like. Equipment light and the like correspond to this. The outer cover 20 is made of, for example, a light-shielding resin material. As shown in FIGS. 24.

Out of these, the outer cover main body 21 is the basic structure of the outer cover 20 . The outer cover main body 21 is formed of, for example, a substantially hollow columnar body whose upper and lower surfaces are open, and as shown in FIG. and fixed to the mounting base 10 by a fitting structure (or fixture) or the like.

Also, the top surface portion 22 is a partitioning means for partitioning the inflow space 40 . The top surface portion 22 is formed of, for example, a substantially circular plate-like body, and is provided substantially horizontally below the outer cover main body 21 as shown in FIGS. 1 to 3 . Further, as shown in FIG. 2, the top surface portion 22 is provided with a display hole 22a. The display hole 22a is a through hole for guiding light emitted from a display unit, which will be described later, to the outside of the fire detection device 1 through the light guide 104a and the display hole 22a shown in FIG.

Also, the first rib portion 23 and the second rib 24 are ribs for partitioning the inflow space 40 . These first ribs 23 and second ribs 24 are each formed of a substantially plate-like body, and as shown in FIG. It is connected to the cover main body 21 or the top surface portion 22 . The "outer cover 20" described above corresponds to the "second incident suppressing means" in the scope of claims.

(Configuration - inflow space)
Returning to FIG. 1 , the inflow space 40 is a space for causing the gas outside the fire detection device 1 to flow into the fire detection device 1 . A plurality of inflow spaces 40 are formed inside the outer cover 20. Specifically, as shown in FIGS. , the second rib portion 24 , and the inner cover 30 form an inflow space 40 .

(Configuration - inner cover)
The inner cover 30 is an incident suppressing means for suppressing the entry of ambient light into the detection space 60. The inner cover 30 covers the detection space 60, the detection section cover 70, the detection section main body 80, and the substrate 100, and covers the inflow space. 40 is a cover for partitioning. The inner cover 30 is, for example, a substantially hollow cylindrical body with an open upper surface, and is made of a light-shielding resin material. As shown in FIG. 30 is provided so as to face the top surface portion 22 of the outer cover 20 with the inflow space 40 interposed therebetween. Further, as shown in FIG. 3, a first opening 30a is provided in the lower side portion of the inner cover 30. As shown in FIG. The first opening 30a is an opening for sending the gas that has flowed into the inflow space 40 to the detection space 60 (that is, an opening for flowing into the inner cover 30). The first opening portion 30a is formed to be smaller than the planar shape of the top surface portion 22, and as shown in FIG. are placed. The above-mentioned "inner cover 30" corresponds to the "first incident suppression means" in the claims, and the above-mentioned "first opening 30a" corresponds to the "opening" in the claims. do.

(configuration - detection space)
The detection space 60 is a space for detecting a detection target, and as shown in FIG. is formed as

(Construction - detector cover)
The detection unit cover 70 is partitioning means for partitioning the detection space 60 and is incident suppressing means for suppressing disturbance light from entering the detection space 60 . The detector cover 70 is a substantially hollow columnar body with an open upper surface, and is made of a light-blocking resin material. Moreover, as shown in FIG. 3, the detection section cover 70 is located inside the inner cover 30 so that the lower side portion of the detection section cover 70 extends from the top of the outer cover 20 via the first opening 30a and the inflow space 40 . It is arranged so as to face the surface portion 22 and is fixed to the detection portion main body 80 . Further, as shown in FIG. 3, a second opening 70a is formed in the lower side portion of the detection section cover 70. As shown in FIG. The second opening 70a is an opening for allowing the gas sent from the first opening 30a to flow into the detection space 60. As shown in FIG. It is provided in a portion corresponding to one opening 30a.

(Composition - insect screen)
The insect net 50 is a net for preventing insects outside the fire detection device 1 from entering the detection space 60 . The insect screen 50 is constructed using a mesh-like circular net, and is attached to the detection section cover 70 as shown in FIG.

(Construction - detector body)
The detector main body 80 is mounting means for mounting the detector cover 70 , and is incident suppressing means for suppressing disturbance light from entering the detection space 60 . The detector main body 80 is a thick plate-shaped body (for example, a substantially circular plate-shaped body) made of, for example, a light-shielding resin material, and is closer to the substrate 100 than the detector cover 70 ( Specifically, as shown in FIG. 3, it is arranged so as to cover the upper surface of the detection unit cover 70, and is fixed to the substrate 100 by a fixture or the like. It is

(Configuration - terminal board)
Returning to FIG. 3 , the terminal board 90 is housing means for housing the inner cover 30 , the detection section cover 70 , the detection section main body 80 , and the board 100 . The terminal board 90 has a substantially hollow columnar shape with an open lower surface, and is made of, for example, a light-shielding resin material. 3, the terminal board 90 is provided so as to cover the inner cover 30, the detection section cover 70, the detection section main body 80, and the substrate 100 from above, and has a fitting structure with respect to the outer cover 20. etc., and is fixed to the mounting base 10 by a fixture or the like through a first mounting hole (not shown) formed in the mounting member 91 .

(Configuration - substrate)
The substrate 100 is mounting means on which various electric circuits (not shown) are mounted. The board 100 is configured using, for example, a known flat circuit board or the like, and as shown in FIG. It is arranged substantially horizontally and fixed to the terminal board 90 by a fixture through a mounting hole (not shown) formed in the terminal board 90 and a second mounting hole (not shown) formed in the mounting member 91. there is

In addition to mounting known components (electrical components) used in the conventional fire detection device 1 on the substrate 100, the substrate 100 also includes a first light emitting unit, a second light emitting unit, a light receiving unit, a display unit, and a communication device. , a power supply unit, a control unit, and a storage unit (all not shown).

(Configuration - substrate - first light emitting part, second light emitting part, light receiving part)
Among these, the first light emitting unit is light emitting means for irradiating detection light (hereinafter referred to as “first detection light”) into the detection space 60, and for example, a known light emitting element (an example of which is an infrared LED) is used. configured as follows. The second light emitting unit is light emitting means for irradiating the detection space 60 with detection light having a wavelength different from that of the first detection light (hereinafter referred to as "second detection light"). as a blue LED, etc.). Further, the light receiving unit receives scattered light due to smoke of the first detection light emitted from the first light emitting unit, outputs a first light receiving signal according to the received scattered light, and emits light from the second light emitting unit. light receiving means for receiving the scattered light of the second detection light from the smoke and outputting a second light receiving signal corresponding to the received scattered light, for example, using a known light receiving element (such as a photodiode as an example) It is configured. In addition, the method of installing the first light emitting unit, the second light emitting unit, and the light receiving unit is arbitrary, but in the embodiment, the first detection light emitted from the first light emitting unit or the second light emitting unit or the second It is installed so that the detected light can be prevented from directly entering the light receiving section through various prism lens sections described later. For example, the angle between the optical axis of the first light emitting section (hereinafter referred to as "first light emitting side optical axis") and the optical axis of the light receiving section (hereinafter referred to as "light receiving side optical axis") is about 135°. A first light emitting unit and a light receiving unit are installed at the positions. Further, the second light emitting unit and the light receiving unit are installed at a position where the angle between the optical axis of the second light emitting unit (hereinafter referred to as "second light emitting side optical axis") and the light receiving side optical axis is about 90°. ing.

(Configuration - board - display part, communication part, power supply part)
In addition, the display unit emits light (hereinafter referred to as “display light”) toward the outside of the fire detection device 1 to display predetermined information (for example, information indicating whether or not a fire has been detected). This is display means, and is configured using, for example, known display means (LED, etc.). The method of projecting light from the display unit is arbitrary, but for example, insertion holes (not shown) provided in each of the detection unit cover 70, the detection unit main body 80, and the inner cover 30, and an outer cover described later. 20 through a light guide 104a inserted into the display hole 22a of the display unit 20, and directing the display light from the display unit toward the outside of the fire detection device 1 to project the light. Also, the communication unit is communication means for communicating with an external device (for example, a receiver, etc.). The power supply unit is power supply means for supplying electric power supplied from a commercial power supply or a battery (not shown) to each unit of the fire detection apparatus 1 .

(Configuration - substrate - control unit, storage unit)
Also, the control unit is control means for controlling the fire detection device 1 . Specifically, this control unit includes a CPU, various programs interpreted and executed on the CPU (including a basic control program such as an OS, and an application program that is started on the OS and realizes a specific function), programs, and It is a computer configured with an internal memory such as a RAM for storing various data. The storage unit is storage means for storing programs and various data necessary for the operation of the fire detection device 1 . This storage unit is configured using a rewritable recording medium, and can use, for example, a non-volatile recording medium such as a flash memory.

(Structure - details of the structure of the main body of the detection unit)
Next, the details of the configuration of the detector main body 80 will be described. FIG. 4 is a bottom view showing the detector main body 80. As shown in FIG. However, the detection unit main body 80 can be manufactured with any shape, method, and material, unless otherwise specified.

In the embodiment, as shown in FIG. 4, the detector main body 80 is provided with a first prism lens portion 81a, a second prism lens portion 81b, a third prism lens portion 81c, and a chamber portion 82. .

(Structure-details of structure of main body of detection unit-first prism lens unit, second prism lens unit, third prism lens unit)
The first prism lens section 81a is for changing the direction of the first detection light from the first light emitting section so that the first detection light enters the detection space 60 (specifically, the first The direction of the detection light is changed so as to be substantially parallel to the side surface of the detection unit main body 80 on the side of the detection space 60). The first prism lens portion 81a is configured using, for example, a known prism lens (the same applies to the second prism lens portion 81b and the third prism lens portion 81c), and as shown in FIG. , are provided in a first chamber portion 83 which will be described later. The second prism lens portion 81b is for changing the direction of the second detection light from the second light emitting portion so that the second detection light is incident on the detection space 60, as shown in FIG. , is provided in a second chamber portion 84 to be described later. The third prism lens portion 81c is for changing the direction of the scattered light received from the detection space 60 so that the scattered light enters the light receiving portion. It is provided in the third chamber part 85 .

(Structure-details of structure of main body of detection unit-chamber)
Returning to FIG. 3, the chamber section 82 is for supporting the first prism lens section 81a, the second prism lens section 81b, the third prism lens section 81c, and the detection section cover . As shown in FIGS. 3 and 4, the chamber section 82 is provided on the lower surface of the detection section main body 80, and includes a first chamber section 83, a second chamber section 84, and a third chamber section 85. .

Among these, the first chamber portion 83 supports a part of the first prism lens portion 81a and the detection portion cover 70, and is formed of, for example, a hollow body having an open top surface and a bottom surface. , the second chamber portion 84 and the third chamber portion 85) are provided at positions corresponding to the first light emitting portions, as shown in FIG. Further, as shown in FIG. 4, the first chamber portion 83 includes a first incident port (not shown) for causing the first detection light emitted from the first light emitting portion to enter the prism lens portion 81a, a first A first insertion opening 83b is provided for allowing the first detection light whose direction has been changed by the 1-prism lens portion 81a to enter the detection space 60 by passing the first detection light.

The second chamber portion 84 supports the second prism lens portion 81b and another part of the detection portion cover 70, and is provided at a position corresponding to the second light emitting portion as shown in FIG. ing. As shown in FIG. 4, the second chamber section 84 has a second entrance (not shown) for allowing the second detection light emitted from the second light emitting section to enter the second prism lens section 81b. , and a second insertion opening 84b for allowing the second detection light whose direction is changed by the second prism lens portion 81b to enter the detection space 60 by passing through the second detection light.

The third chamber portion 85 supports the third prism lens portion 81c and another part of the detection portion cover 70, and is provided at a position corresponding to the light receiving portion as shown in FIG. . In addition, as shown in FIG. 4, the third chamber portion 85 includes a third insertion opening 85a for allowing scattered light from the detection space 60 to enter the third prism lens portion 81c, and a third prism. A third entrance (not shown) is provided for causing the scattered light whose direction has been changed by the lens portion 81c to enter the light receiving portion.

Although the method of forming the chamber portion 82 is arbitrary, for example, the chamber portion 82 and the detection portion main body 80 may be integrally formed by injection molding a resin material having a light blocking effect.

The first prism lens portion 81a, the second prism lens portion 81b, the third prism lens portion 81c, and the detection portion cover 70 may be attached by any method. After the lens portion 81c is vertically inserted into each of the first chamber portion 83 to the third chamber portion 85, a part of the upper portion of the detection portion cover 70 is fitted into the first chamber portion 83 to the third chamber portion 85. It corresponds to attaching by

(Construction-incident suppression structure)
Next, the incident suppression structure of the fire detection device 1 will be described. FIG. 5 is a diagram showing a situation in which disturbance light is incident on the detection space 60 from the outside of the fire detection device 1 through the inflow space 40, and shows the area corresponding to FIG. In FIG. 5, disturbance lights L1 and L2, which will be described later, are indicated by imaginary lines. Features of the incident suppression structure for suppressing direct incidence of disturbance light into the detection space 60 are as follows in the embodiment.

(Configuration-Incident Suppressing Structure-First Feature)
First, with respect to the first feature of the incident suppression structure, at least the outer cover 20 and the inner cover 30 allow gas from the outside of the fire detection device 1 to flow into the detection space 60 through the inflow space 40, and fire detection The inflow space 40 and the detection space 60 are partitioned so that disturbance light from the outside of the apparatus 1 can be prevented from directly entering the detection space 60 via the inflow space 40 . Specifically, as shown in FIG. 5 , the outer cover 20 and the inner cover 30 are designed to prevent disturbance light L1 and L2 from entering the detection space 60 through the inflow space 40 and the first opening 30a. L1 and L2 are configured to be able to reflect multiple times with respect to the outer cover 20 or the inner cover 30 . 5 is reflected by the outer cover 20 and the inner cover 30 to enter the detection space 60, and the disturbance light L2 shown on the right side of FIG. , and reflected by the inner cover 30 to go out of the fire detection apparatus 1. FIG. However, the disturbance light is not limited to this, and may be disturbance light having a predetermined incident angle different from the incident angles of the disturbance lights L1 and L2. In the embodiment, the outer cover 20 and the inner cover 30 are configured so that the ambient light can be reflected multiple times on the outer cover 20 or the inner cover 30 .

In this case, the specific configuration of the outer cover 20 is arbitrary, but in the embodiment, it is as follows. That is, first, in the configuration of the top surface portion 22, the size of the planar shape of the top surface portion 22 is set to a length that allows disturbance light incident on the inflow space 40 at a predetermined angle to be reflected by the top surface portion 22 multiple times. For example, it is set slightly smaller than the planar size of the outer cover main body 21 . In addition, regarding the installation method of the top surface part 22, it is installed at a position corresponding to the open end on the lower side of the outer cover main body 21, and a predetermined amount of gas from the outside of the fire detection device 1 flows through the inflow space 40. It is installed with a gap from the lower side portion of the inner cover 30 so that it can flow into the detection space 60 . The length of this gap may be set based on, for example, experimental results (the same applies to the length of gaps between first rib portions 23, which will be described later).

Also, the configurations of the first rib portion 23 and the second rib portion 24 are as follows.

That is, first, as shown in FIGS. 3 and 5, the first rib portion 23 and the second rib portion 24 are arranged in the inflow space 40 along a direction perpendicular to the installation surface 2 (vertical direction in the drawings). placed respectively. With such a configuration, when disturbance light enters the detection space 60 through the inflow space 40, the disturbance light can be reflected multiple times against the first rib portion 23 and the second rib portion 24, thereby detecting Ambient light entering the space 60 can be attenuated. In particular, disturbance light incident in a direction substantially parallel to the installation surface 2 can be prevented from being reflected multiple times and entering the first opening 30a.

Further, the first rib portion 23 and the second rib portion 24 are arranged so that the gas flowing into the inflow space 40 is not prevented from flowing into the first opening portion 30a by the first rib portion 23 and the second rib portion 24. It is configured. Specifically, the first rib portion 23 and the second rib portion 24 are arranged radially from the vicinity of the center of the inner cover 30 . In this case, at least one of the first rib portion 23 and the second rib portion 24 may be spaced apart from each other or may be in contact with each other, In the embodiment, the first rib portions 23 are arranged at intervals from each other, and the second rib portions 24 are arranged so as to contact each other (specifically, the first opening of the second rib portion 24). are arranged so that the ends on the side of the portion 30a are in contact with each other). Further, the size of the second rib portion 24 is set to a size that allows disturbance light entering the inflow space 40 at a predetermined angle to be reflected by the second rib portion 24 . For example, as shown in FIG. 5, the length of the second rib portion 24 in the vertical direction is set so that the tip portion of the second rib portion 24 is located near the first opening 30a. Further, the length of the second rib portion 24 in the front-rear direction is set shorter than the diameter of the top surface portion 22 . Moreover, it is desirable to set the thickness of the second rib portion 24 as thin as possible so as not to narrow the first opening portion 30a. With the configuration described above, it is possible to ensure the inflow of the gas that has flowed into the inflow space 40 into the first opening 30a, and the detection accuracy of the fire detection device 1 can be easily maintained.

Moreover, although the specific configuration of the inner cover 30 is arbitrary, it is as follows in the embodiment. That is, first, the shape and size of the lower side portion of the inner cover 30 are determined so that disturbance light incident on the inflow space 40 at a predetermined angle can be reflected by the lower side portion of the inner cover 30 multiple times. have set. For example, the size of the planar shape of the lower side portion of the inner cover 30 is set to substantially the same size as the size of the planar shape of the top surface portion 22 . 5, at least part of the lower side portion of the inner cover 30 (in FIG. 5, the lower side portion of the inner cover 30 is , a portion corresponding to the outer portion of the inflow space 40 to be described later) are set in an upwardly inclined shape toward the outside of the inner cover 30 . In addition, the inner cover 30 is installed at a position where disturbance light entering the inflow space 40 at a predetermined angle can be reflected multiple times by the lower side portion of the inner cover 30 and the top surface portion 22 . For example, as shown in FIG. 5, the inner cover 30 is installed at a position where the entire lower side portion of the inner cover 30 substantially overlaps the top surface portion 22 when viewed in the planar direction.

Due to such a first feature, compared to the conventional technology (technology in which the detection space and the inflow space are arranged side by side along the installation surface), disturbance light is allowed to flow into the detection space 60 while reliably flowing the gas into the detection space 60. Directly entering the detection space 60 via the space 40 can be suppressed, and the detection accuracy of the fire detection device 1 can be maintained. Further, when the disturbance light enters the detection space 60 through the inflow space 40, the disturbance light is applied to the inner cover 30 (specifically, the lower side portion of the inner cover 30) or the outer cover 20 (specifically, , top surface portion 22 and second rib portion 24). Therefore, disturbance light entering the detection space 60 can be effectively attenuated, making it easier to maintain the inflow of gas and the detection accuracy of the fire detection device 1 .

(Configuration-Incident Suppressing Structure-Second Feature)
Returning to FIG. 3, next, the second feature of the incident suppression structure is that the length of the inner portion of the inflow space 40 in the direction perpendicular to the installation surface 2 (vertical direction) is uniform, and the length of the inflow space 40 is uniform. The inner cover 30 and the outer cover 20 are configured such that the length in the direction perpendicular to the installation surface 2 at the outer portion of the cover increases toward the outside. Here, the "inner portion of the inflow space 40" refers to a portion of the inflow space 40 located outside the outer edge of the first opening 30a from the central portion (in FIG. A portion corresponding to a portion slightly outside the intermediate portion between the central portion and the outer edge portion of the face portion 22). In addition, in the embodiment, the "outside portion of the inflow space 40" is explained as a portion extending from a portion of the inflow space 40 outside the outer edge of the first opening 30a to the outer edge. .

Specifically, as shown in FIG. 3, the top surface portion 22 of the outer cover 20 is formed of a flat plate-like body. A portion of the lower side portion of the inner cover 30 that corresponds to the inner portion of the inflow space 40 is formed flat and parallel to the top surface portion 22 . In addition, the outer portion of the inflow space 40 of the lower side portion of the inner cover 30 is formed in an inclined shape that slopes upward toward the outside of the inner cover 30 as described above. In this case, the first opening portion 30a is arranged so that the entire first opening portion 30a faces the inner portion of the inflow space 40, and the top surface portion 22 and the lower side portion of the inner cover 30 are arranged. , is arranged in parallel with the portion corresponding to the inner portion of the inflow space 40 .

Due to this second feature, the length of the inner portion of the inflow space 40 in the direction perpendicular to the installation surface 2 becomes shorter toward the inside, thereby allowing the gas to flow into the first opening 30a. Easier to ensure reliability. In addition, compared to the case where the length of the inner portion of the inflow space 40 in the direction perpendicular to the installation surface 2 increases toward the inside, disturbance light passes through the inflow space 40 and the first opening 30a to the detection space. Direct incidence on 60 can be suppressed. Therefore, it becomes easier to maintain the inflow of gas and the detection accuracy of the fire detection device 1 .

(Construction-Light reception suppression structure)
Next, the light receiving suppression structure of the fire detection device 1 will be described. FIG. 6 is an enlarged view of the region of the light reception suppressing portion 110 described later in FIG. In FIG. 6, the light receiving side optical axis LL is indicated by an imaginary line. The features of the light receiving suppression structure for suppressing the light receiving section from receiving disturbance light that has entered the detection space 60 are as described below in the embodiment.

That is, as shown in FIG. 6, a light reception suppressing portion 110 is provided inside the inner cover 30 . Here, the light reception suppressing section 110 is light reception suppression means for suppressing the light receiving section from receiving disturbance light incident on the detection space 60 . As shown in FIGS. 4 and 6, the light reception suppressing portion 110 is provided in the third chamber portion (specifically, a portion inside the third prism lens portion 81c in the third chamber portion). A first light shielding rib 111 , a second light shielding rib 112 and a third light shielding rib 113 are provided.

Among these, the first light-shielding rib 111 , the second light-shielding rib 112 , and the third light-shielding rib 113 are ribs for configuring the light reception suppressing section 110 . The first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113 are, as shown in FIG. They are arranged side by side at intervals along the incident direction of the scattered light (the first detection light or the second detection light) (that is, the axial direction of the light-receiving side optical axis LL). Specifically, the first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113 are arranged in order from the front side toward the back side in the incident direction. As for the length of the interval, in the embodiment, it is assumed that disturbance light having a predetermined incident angle is received by the light receiving portion by the first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113. It is set to a length that can be suppressed, and may be set based on, for example, experimental results. The "third insertion opening 85a" described above corresponds to the "insertion opening" in the claims.

Further, the specific configuration of the third insertion openings 85a of the first light shielding ribs 111, the second light shielding ribs 112, and the third light shielding ribs 113 is arbitrary, but in the embodiment, the front side in the incident direction It is set so that it becomes smaller as it goes. That is, the third insertion opening 85a of the second light shielding rib 112 is set smaller than the third insertion opening 85a of the third light shielding rib 113, and the third insertion opening 85a of the first light shielding rib 111 is set to be smaller than the third insertion opening 85a of the second light shielding rib 112. It is set to be smaller than the third insertion opening 85a. As a result, compared to the case where the third insertion openings 85a of the first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113 are made larger toward the near side in the incident direction, the third insertion openings 85a are It is possible to suppress the detection light incident through the third insertion opening 85a from exiting to the outside, and it becomes easier to maintain the detection accuracy of the fire detection device 1 .

The light reception suppressing portion 110 may be formed by any method, but for example, the light reception suppressing portion 110 and the detection portion main body 80 may be integrally formed by injection molding a resin material having light blocking properties. . However, the present invention is not limited to this, and for example, after forming the light reception suppression unit 110 and the detection unit main body 80 separately, the light reception suppression unit 110 may be fixed to the detection unit main body 80 with a fixture or the like.

With such a light reception suppression structure, the light reception suppression section 110 can suppress the disturbance light incident on the detection space 60 from being received by the light reception section, and the detection accuracy of the fire detection device 1 can be more easily maintained.

(About the action of the fire detection device)
Returning to FIG. 5, the operation of the fire detection device 1 configured in this way will be described next. The action of the fire detection device 1 includes action corresponding to ambient light (hereinafter referred to as "disturbance light action") and action corresponding to gas outside the fire detection device 1 (hereinafter referred to as "gas action"). and The disturbance light effect and the gas effect will be described below.

(About the action of the fire detection device - Ambient light action)
First, the disturbance light effect will be described.

That is, for example, in a state where the fire detection device 1 is attached to the installation surface 2, if the disturbance lights L1 and L2 try to enter the detection space 60 through the inflow space 40, the disturbance lights L1 and L2 are reflected multiple times by the inner cover 30 (specifically, the lower side portion of the inner cover 30) or the outer cover 20 (specifically, the top surface portion 22 and the second rib portion 24). As a result, these disturbance lights L1 and L2 are suppressed from directly entering the detection space 60, so compared to the conventional technology (the technology in which the detection space and the inflow space are arranged side by side along the installation surface) Therefore, the detection accuracy of the fire detection device 1 can be maintained. Further, even if the disturbance light L1 reflected multiple times flows into the detection space 60, the disturbance light L1 is attenuated by the reflection. It is possible to reduce the influence on the detection accuracy of

Further, for example, even if the ambient light that is not reflected by the inner cover 30 or the outer cover 20 (or the ambient light that has been reflected multiple times) flows into the detection space 60, the light reception suppression unit 110 (specifically, the second Since the first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113 suppress the disturbance light from entering the light receiving section, the detection accuracy of the fire detection device 1 can be easily maintained.

(About the action of the fire detection device - gas action)
Next, gas action will be described.

That is, for example, in a state where the fire detection device 1 is attached to the installation surface 2, if the gas outside the fire detection device 1 tries to flow into the detection space 60 through the inflow space 40, the inner cover 30 (specifically, is the lower side portion of the inner cover 30) and the outer cover 20 (specifically, the top surface portion 22, the first rib portion 23, and the second rib portion 24). A predetermined amount of gas flows into the detection space 60 through the second opening 70a. As a result, it becomes possible to maintain the inflow of gas into the detection space 60, as in the conventional technique.

(Effect of Embodiment)
As described above, according to the embodiment, the detection space 60 for detecting the detection target is provided at a position closer to the installation surface 2 than the inflow space 40 inside the fire detection device 1. 60, an incident suppressing means for suppressing ambient light from entering the detection space 60 from the outside of the fire detection device 1, the gas can flow into the detection space 60 through the inflow space 40, and an incidence suppressing means for partitioning the inflow space 40 and the detection space 60 so as to be able to suppress the disturbance light from directly entering the detection space 60 via the inflow space 40. (Technology in which the detection space and the inflow space are arranged side by side along the installation surface), while allowing the gas to reliably flow into the detection space 60, the ambient light is directly directed to the detection space 60 via the inflow space 40. can be suppressed, and the inflow of gas and the detection accuracy of the fire detection device 1 can be maintained. Further, when disturbance light is incident on the detection space 60 through the inflow space 40 and the first opening 30a, the inner cover is arranged so that the disturbance light can be reflected multiple times with respect to the inner cover 30 or the outer cover 20. Since 30 and the outer cover 20 are configured, when the ambient light enters the detection space 60 through the inflow space 40, the ambient light can be reflected multiple times against the inner cover 30 or the outer cover 20. FIG. Therefore, disturbance light entering the detection space 60 can be effectively attenuated, and the detection accuracy of the fire detection device 1 can be easily maintained.

Further, the plate-like first rib portion 23 and the plate-like second rib portion 24 provided on the outer cover 20 are arranged along the direction orthogonal to the installation surface 2 in the inflow space 40 . Since the portion 23 and the second rib portion 24 are provided, when the disturbance light enters the detection space 60 through the inflow space 40, the disturbance light is directed to the first rib portion 23 and the second rib portion 24 a plurality of times. It can be reflected and can attenuate the disturbance light incident on the detection space 60 . In particular, disturbance light incident in a direction substantially parallel to the installation surface 2 can be prevented from being reflected multiple times and entering the first opening 30a. Further, the first rib portion 23 and the second rib portion 24 are arranged so that the gas flowing into the inflow space 40 is not prevented from flowing into the first opening portion 30a by the first rib portion 23 and the second rib portion 24. With this configuration, it is possible to ensure the inflow of the gas that has flowed into the inflow space 40 into the first opening 30a, and it becomes easier to maintain the detection accuracy of the fire detection device 1 .

Further, the first opening 30a is arranged so that the entire first opening 30a faces the inner portion of the inflow space 40, and the length of the inner portion of the inflow space 40 in the direction orthogonal to the installation surface 2 is Since the inner cover 30 and the outer cover 20 are configured so that the length in the direction orthogonal to the installation surface 2 in the outer portion of the inflow space 40 becomes longer toward the outside, the inside of the inflow space 40 Compared to the case where the length of the portion in the direction perpendicular to the installation surface 2 decreases toward the inside, it becomes easier to ensure the inflow of the gas to the first opening 30a. In addition, compared to the case where the length of the inner portion of the inflow space 40 in the direction perpendicular to the installation surface 2 increases toward the inside, disturbance light passes through the inflow space 40 and the first opening 30a to the detection space. Direct incidence on 60 can be suppressed. Therefore, it becomes easier to maintain the inflow of gas and the detection accuracy of the fire detection device 1 .

Further, since the light reception suppressing portion 110 provided inside the inner cover 30 is provided for suppressing the light receiving portion from receiving the disturbance light incident on the detection space 60, the light reception suppression portion 110 is provided. The unit 110 can prevent the light receiving unit from receiving disturbance light that has entered the detection space 60 , making it easier to maintain the detection accuracy of the fire detection device 1 .

Further, since the third insertion openings 85a of the first light shielding ribs 111, the second light shielding ribs 112, and the third light shielding ribs 113 are made smaller toward the near side in the incident direction, the first light shielding ribs 111 and the second light shielding ribs 112 and third light shielding ribs 113, and the third light shielding ribs 113, the detection light incident through the third insertion openings 85a increases toward the front side in the incident direction. It is possible to suppress going out through the fire detection device 1, and it becomes easier to maintain the detection accuracy of the fire detection device 1.

[III] Modifications to the Embodiments Although the embodiments according to the present invention have been described above, specific configurations and means of the present invention are within the scope of the technical ideas of each invention described in the claims. In can be optionally modified and improved. Such modifications will be described below.

(Problem to be solved and effect of invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the contents described above, and may differ depending on the details of the implementation environment and configuration of the invention. or only part of the effects described above.

(About fire detection device)
Although the fire detection device 1 has the inner cover 30 in the above embodiment, the present invention is not limited to this, and the inner cover 30 may be omitted, for example. In this case, for example, a portion of the lower side portion of the outer cover 20 may be configured to function similarly to the lower side portion of the inner cover 30 . That is, the shape and size of a portion of the lower side portion of the outer cover 20 is substantially the same as that of the lower side portion of the inner cover 30, and the disturbance light incident on the inflow space 40 at a predetermined angle is projected onto the outer cover 20. It may be configured to allow multiple reflections by the lower side.

Further, in the above-described embodiment, the fire detection device 1 is described as including the light reception suppressing section 110, but the present invention is not limited to this, and the light reception suppressing section 110 may be omitted, for example.

Further, in the above embodiment, the fire detection device 1 has been described as including the first light emitting unit and the second light emitting unit. or one may be omitted.

(Regarding the first rib portion and the second rib portion)
Although the first rib portion 23 and the second rib portion 24 are provided on the outer cover 20 in the above embodiment, they may be provided on the inner cover 30, for example.

(About the detector body)
In the above embodiment, the detector body 80 is provided with the first prism lens portion 81a, the second prism lens portion 81b, the third prism lens portion 81c, and the chamber portion 82. However, the present invention is limited to this. Instead, for example, the first prism lens portion 81a, the second prism lens portion 81b, the third prism lens portion 81c, and the chamber portion 82 may be omitted. In this case, the specific configuration of the detection unit main body 80 is arbitrary. may be provided respectively. Further, optical path holes for forming optical paths between each of the first light emitting section, the second light emitting section, and the light receiving section and the detection space 60 may be formed in the detection section main body 80 . With such a configuration, it is possible to detect the detection target in substantially the same manner as in the above-described embodiment.

(Regarding the light reception suppression part)
In the above-described embodiment, light reception suppressing section 110 has three light shielding ribs (first light shielding rib 111, second light shielding rib 112, and third light shielding rib 113), but the present invention is not limited to this. For example, two or less light shielding ribs may be provided, or four or more light shielding ribs may be provided.

Further, in the above embodiment, the third insertion openings 85a of the first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113 are set to become smaller toward the front side in the incident direction. However, the present invention is not limited to this. For example, the third insertion openings 85a of the first light shielding ribs 111, the second light shielding ribs 112, and the third light shielding ribs 113 may be set to increase toward the front side in the incident direction. Alternatively, the third insertion openings 85a of the first light shielding rib 111, the second light shielding rib 112, and the third light shielding rib 113 may be set uniformly large.

(Appendix)
The fire detection device of Supplementary Note 1 is a fire detection device that is attached to the installation surface of an installation target, is a fire detection device for detecting fire in a monitoring area, and is a fire detection device that is provided inside the fire detection device. A space, which is an inflow space into which gas from the outside of the fire detection device can flow, and a detection space for detecting a detection target, wherein the installation surface is located inside the fire detection device rather than the inflow space. and an incident suppression means for suppressing disturbance light from entering the detection space from the outside of the fire detection device, wherein the gas is introduced into the detection space through the inflow space. Incidence suppressing means for partitioning the inflow space and the detection space so that the ambient light can enter the detection space and can be suppressed from directly entering the detection space through the inflow space. and, the incident suppressing means is a first incident suppressing means for accommodating the detection space, the first incident suppressing means configured to partition a part of the inflow space; A second incidence suppression means for accommodating an incidence suppression means, the second incidence suppression means configured to partition another part of the inflow space; an opening provided on a side portion opposite to the side portion on the installation surface side, the opening portion for allowing the gas that has flowed into the inflow space to flow into the interior of the first incident suppressing means; and when the disturbance light enters the detection space through the inflow space and the opening, the disturbance light can be reflected multiple times to the first incidence suppressing means or the second incidence suppressing means. The first incident suppressing means and the second incident suppressing means are configured so as to be the following.

Further, in the fire detection device according to Supplementary Note 2, in the fire detection device according to Supplementary Note 1, a plurality of plate-shaped ribs provided in the first incident suppressing means or the second incident suppressing means are provided in the inflow space. a plurality of ribs arranged along a direction orthogonal to the installation surface, so that the gas flowed into the inflow space is not blocked by the plurality of ribs from flowing into the opening, The plurality of ribs were configured.

Further, the fire detection device according to Supplementary Note 3 is the fire detection device according to Supplementary Note 1 or 2, wherein the opening is arranged so that the entire opening faces the inner portion of the inflow space. The length of the inner portion in the direction orthogonal to the installation surface is uniform, and the length of the outer portion of the inflow space in the direction orthogonal to the installation surface increases toward the outside. The first incident suppressing means and the second incident suppressing means are configured.

Further, the fire detection device of Appendix 4 is the fire detection device according to any one of Appendixes 1 to 3, wherein the light emitting means is provided inside the first incident suppressing means, and detects in the detection space. light emitting means for emitting light; and light receiving means provided inside the first incident suppressing means, wherein the detection light emitted from the light emitting means is scattered by the detection object in the detection space. and a light receiving suppressing means provided inside the first incident suppressing means for suppressing the disturbance light incident on the detection space from being received by the light receiving means. and light reception suppressing means for.

Further, the fire detection device of appendix 5 is the fire detection device of appendix 4, wherein the light reception suppressing means is a plurality of light shielding ribs arranged side by side at intervals along the incident direction of the detection light. A plurality of light shielding ribs each having an insertion opening for inserting the detection light is provided, and the insertion openings of the plurality of light shielding ribs are made smaller toward the front side in the incident direction.

(Effect of Supplementary Note)
According to the fire detection device according to appendix 1, the detection space for detecting the detection target, the detection space provided in the interior of the fire detection device at a position closer to the installation surface than the inflow space; An incident suppressing means for suppressing disturbance light from entering the detection space from the outside of the fire detection device, wherein gas can flow into the detection space through the inflow space, and disturbance light passes through the inflow space. and an incident suppressing means for partitioning the inflow space and the detection space so as to be able to suppress direct incidence into the detection space through the conventional technology (detection space and inflow space along the installation surface Compared to the technology that is installed side by side), it is possible to suppress the direct incidence of ambient light into the detection space through the inflow space while allowing the gas to flow into the detection space. It becomes possible to maintain the detection accuracy of the detection device. Further, when disturbance light enters the detection space through the inflow space and the opening, the disturbance light can be reflected multiple times with respect to the first incidence suppressing means or the second incidence suppressing means. Since the suppressing means and the second incident suppressing means are configured, the ambient light is reflected multiple times to the first incident suppressing means or the second incident suppressing means when the ambient light enters the detection space through the inflow space. be able to. Therefore, disturbance light entering the detection space can be effectively attenuated, and the detection accuracy of the fire detection device can be easily maintained.

According to the fire detection device described in Supplementary Note 2, there are a plurality of plate-shaped ribs provided on the first incident suppression means or the second incident suppression means, along the direction orthogonal to the installation surface in the inflow space Since a plurality of ribs are arranged respectively, when disturbance light enters the detection space via the inflow space, the disturbance light can be reflected multiple times by the plurality of ribs, and enters the detection space. Ambient light can be attenuated. In particular, disturbance light incident in a direction substantially parallel to the installation surface can be prevented from being reflected multiple times and entering the opening. In addition, since a plurality of ribs are formed so that the flow of the gas flowing into the inflow space into the opening is not blocked by the plurality of ribs, the flow of the gas flowing into the inflow space into the opening is ensured. This makes it easier to maintain the detection accuracy of the fire detection device.

According to the fire detection device described in Supplementary Note 3, the opening is arranged so that the entire opening faces the inner portion of the inflow space, and the length in the direction orthogonal to the installation surface in the inner portion of the inflow space is is uniform, and the length in the direction perpendicular to the installation surface in the outer portion of the inflow space increases toward the outside. As compared with the case where the length in the direction perpendicular to the installation surface in the inner portion of the opening becomes shorter toward the inside, it becomes easier to secure the inflow of the gas into the opening. In addition, disturbance light directly enters the detection space through the inflow space and the opening, compared to the case where the length of the inner portion of the inflow space in the direction orthogonal to the installation surface increases toward the inside. can be suppressed. Therefore, it becomes easier to maintain the inflow of gas and the detection accuracy of the fire detection device.

According to the fire detection device described in Supplementary Note 4, the light reception suppressing means provided inside the first incident suppressing means receives light for suppressing the disturbance light incident on the detection space from being received by the light receiving means. Since the suppressing means is provided, it is possible to suppress the ambient light incident on the detection space from being received by the light receiving means by the light receiving suppressing means, thereby further facilitating maintenance of the detection accuracy of the fire detection apparatus.

According to the fire detection device described in Supplementary Note 5, since the insertion openings of the plurality of light shielding ribs are made smaller toward the front side in the incident direction, the insertion openings of the plurality of light shielding ribs are made larger toward the front side in the incident direction. As compared with the case, detection light incident through these insertion openings can be suppressed from exiting to the outside through these insertion openings, making it easier to maintain the detection accuracy of the fire detection device.

Reference Signs List 1 fire detection device 2 installation surface 10 mounting base 20 outer cover 21 outer cover body 22 top surface 22a display hole 23 first rib 24 second rib 30 inner cover 30a first opening 40 inflow space 50 insect screen 60 detection space 70 detection section cover 70a second opening 80 detection section main body 81a first prism lens section 81b second prism lens section 81c third prism lens section 82 chamber section 83 first chamber section 83b first insertion opening 84 second chamber section 84b Second insertion port 85 Third chamber portion 85a Third insertion port 90 Terminal board 91 Mounting member 100 Substrate 104a Light guide 110 Light reception suppressing portion 111 First light shielding rib 112 Second light shielding rib 113 Third light shielding rib L1, L2 Ambient light LL Light-receiving side optical axis

Claims (1)

A fire detection device that is attached to an installation surface of an installation target, and is a fire detection device for detecting a fire in a monitoring area,
an inflow space provided inside the fire detection device, the inflow space into which gas from the outside of the fire detection device can flow;
a detection space for detecting a detection target;
Incidence suppression means for suppressing disturbance light from entering the detection space from the outside of the fire detection device, wherein the gas can flow into the detection space via the inflow space, and the disturbance light an incidence suppressing means for partitioning the inflow space and the detection space so as to be able to suppress direct incidence of light into the detection space through the inflow space;
a light emitting means provided inside the incident suppressing means for irradiating the detection space with detection light;
a light-receiving means provided inside the incident suppressing means for receiving scattered light generated when the detection light emitted from the light-emitting means is scattered by the detection object in the detection space; ,
light reception suppression means provided inside the incident suppression means for suppressing the disturbance light incident on the detection space from being received by the light reception means;
The light-receiving suppressing means includes a plurality of light-shielding ribs arranged side by side at intervals along the direction of incidence of the detection light, the plurality of light-shielding ribs each having an insertion opening through which the detection light passes. ,
The insertion openings of the plurality of light shielding ribs are made smaller toward the front side in the incident direction,
Fire detection device.

Images