JP7458021B2 - Smoke detectors - Google Patents

Description

TECHNICAL FIELD This disclosure relates generally to smoke detectors. More particularly, the present disclosure relates to photoelectric smoke detectors.

Patent Document 1 discloses a smoke detector. This smoke detector includes a smoke sensing section that optically detects smoke using a light emitting section and a light receiving section. The smoke sensing section includes an optical base in which a light emitting section and a light receiving section are housed. The optical base is covered with insect netting.

Japanese Patent Application Publication No. 2010-257258

In the smoke detector described in Patent Document 1, there was a possibility that certain insects could invade the inside of the smoke detector through the insect screen. As a result, there was a possibility that this smoke detector would cause a false detection due to the invading insect.

The present disclosure aims to provide a smoke detector that easily reduces the possibility of false detection.

A smoke detector according to one aspect of the present disclosure includes a housing, a photoelectric sensing block, and a suppression structure. The casing has an opening through which smoke can flow in from the outside. The sensing block has a sensing space inside the housing and detects smoke within the sensing space. The suppression structure suppresses at least a specific insect from entering the sensing space. The suppression structure includes a wall that is provided in a region between the opening and the sensing space inside the housing and protrudes from a bottom wall of the housing.
A smoke detector according to one aspect of the present disclosure includes a housing, a photoelectric sensing block, and a suppression structure. The casing has an opening through which smoke can flow in from the outside. The sensing block has a sensing space inside the housing and detects smoke within the sensing space. The suppression structure suppresses at least a specific insect from entering the sensing space. The suppression structure includes the casing made of a material that has chargeability.
A smoke detector according to one aspect of the present disclosure includes a housing, a photoelectric sensing block, and a suppression structure. The casing has an opening through which smoke can flow in from the outside. The sensing block has a sensing space inside the housing and detects smoke within the sensing space. The suppression structure suppresses at least a specific insect from entering the sensing space. The suppressing structure includes a projecting wall that protrudes toward the outside of the housing from a periphery of the opening in an outer wall of the housing.

The present disclosure has an advantage in that the possibility of false detection is easily reduced.

FIG. 1 is an exploded perspective view from above of a smoke detector according to an embodiment of the present disclosure. FIG. 2 is a perspective view of the smoke detector as viewed from above. FIG. 3 is a schematic diagram of an insect screen in the above smoke detector. FIG. 4 is an external perspective view of the smoke detector according to Modification 1 of the embodiment of the present disclosure, viewed from above, with the second cover removed. FIG. 5 is a sectional view of a main part of the smoke detector same as above. FIG. 6 is an external perspective view of another configuration of the same smoke detector as seen from above, with the second cover removed. FIG. 7 is a sectional view of a main part of a smoke detector according to a second modification of an embodiment of the present disclosure. FIG. 8 is a sectional view of a main part of another structure of the smoke detector same as above. FIG. 9 is a cross-sectional view of a main portion of a smoke detector according to a third modification of an embodiment of the present disclosure. FIG. 10 is an external perspective view of a smoke detector according to a fourth modification of an embodiment of the present disclosure, with the second cover removed, as seen from above. FIG. 11 is a sectional view of a main part of a smoke detector according to a fifth modification of an embodiment of the present disclosure.

(1) Overview The smoke detector 100 (see FIG. 1) of this embodiment is a disaster prevention device that issues an alarm when smoke generated by a fire or the like is detected. In other words, when smoke occurs when a disaster such as a fire occurs, the smoke detector 100 detects the smoke and issues an alarm by, for example, outputting an alarm sound or linking with other equipment using a communication function. . The "disaster prevention equipment" referred to in the present disclosure is, for example, equipment installed in a facility for the purpose of preventing disasters such as fires, preventing the spread of damage caused by disasters, or recovering from disasters.

The smoke detector 100 is installed and used in a facility. This embodiment exemplifies a case where the smoke detector 100 is used in a non-residential facility such as a hotel, office building, school, welfare facility, commercial facility, theme park, hospital, or factory. Of course, the smoke detector 100 is not limited to this example, and may be used in facilities such as apartment complexes or single-family houses. The smoke detector 100 is installed in a facility by being attached to a ceiling or wall, for example, in a living room, a hallway, or a staircase of the facility.

As shown in FIGS. 1 and 2, the smoke detector 100 includes a housing 1, a photoelectric sensing block 2, and a suppression structure 3. Various components including a sensing block 2 are housed within the casing 1 .

The housing 1 has an opening 103 through which smoke can enter from the outside. That is, when smoke is generated due to a fire or the like, the generated smoke flows into the interior of the casing 1 through the opening 103.

The sensing block 2 has a sensing space Sp1 inside the housing 1, and detects smoke within the sensing space Sp1. That is, the smoke that has flowed into the interior of the housing 1 is taken into the sensing space Sp1 in the sensing block 2 provided inside the housing 1. Thereby, the photoelectric sensing block 2 detects smoke within the sensing space Sp1.

In the present disclosure, "photoelectric type" means that the light emitting section 22 and the light receiving section 23 of the sensing block 2 are used to control the amount of light reflected by smoke in the sensing space Sp1 or the light that passes through the sensing space Sp1. Refers to a method of detecting smoke based on changes. In this embodiment, the light emitting unit 22 outputs light toward the sensing space Sp1. The light receiving section 23 is arranged at a position where direct light from the light emitting section 22 does not enter, but where light scattered by smoke in the sensing space Sp1 enters. As a result, when there is no smoke in the sensing space Sp1, the light receiving section 23 does not receive the light output from the light emitting section 22, and when smoke is present in the sensing space Sp1, the light receiving section 23 does not receive the light output from the light emitting section 22. 22 and receives light scattered by smoke (scattered light). Therefore, the smoke detector 100 can detect smoke existing in the sensing space Sp1 depending on the light receiving state at the light receiving section 23.

The suppression structure 3 suppresses at least the invasion of a specific insect A1 (see FIG. 3) into the sensing space Sp1. The suppression structure 3 has a structure that suppresses the specific insect A1 from entering the sensing space Sp1 by suppressing the specific insect A1 from entering the inside of the casing 1, as well as a structure that suppresses the specific insect A1 that has entered the inside of the casing 1. It may include a structure that suppresses the invasion of insect A1 into sensing space Sp1.

The "specific insects" referred to in the present disclosure have a characteristic of moving by crawling or riding the wind because they lack the ability to fly by themselves. Specifically, the specific insect A1 has a long and slender body, and most have a body length of about 2 mm. The specific insect A1 includes winged species and wingless species. A specific winged insect A1, for example, has two pairs of elongated wings with long peripheral hairs. Certain insects A1 undergo incomplete metamorphosis. In addition, certain insects A1 basically suck the juices of plants, but saprophagous and carnivorous species are also known. In the example shown in FIG. 3, the specific insect A1 is a winged type, but wingless types are also known. Note that the specific insect A1 shown in FIG. 3 merely represents a general winged insect, and does not directly represent the actual specific insect A1.

The specific insect A1 may, for example, crawl or be carried by the wind, and attach to the ceiling or wall on which the smoke detector 100 is installed, or may invade the interior of the housing 1 through the opening 103. If the smoke detector 100 does not have a suppression structure 3, the specific insect A1 may invade the sensing space Sp1 by crawling along the ceiling, wall, or inner wall of the housing 1. When the specific insect A1 invades the sensing space Sp1, the light output from the light-emitting unit 22 may be reflected and scattered by the specific insect A1, and the light-receiving unit 23 may receive the scattered light. In this case, the smoke detector 100 may make a false detection even though there is no smoke in the sensing space Sp1.

On the other hand, in this embodiment, the smoke detector 100 includes a suppression structure 3 that suppresses entry of a specific insect A1 into the sensing space Sp1. Therefore, the suppression structure 3 can reduce the possibility that a specific insect A1 will invade the sensing space Sp1. Therefore, this embodiment has the advantage that the possibility of false detection due to the specific insect A1 can be easily reduced.

(2) Details Hereinafter, the configuration of the smoke detector 100 according to the present embodiment will be described in detail. In this embodiment, as an example, the smoke detector 100 will be described as being attached to the ceiling of a facility. Hereinafter, when the smoke detector 100 is attached to the ceiling, the direction perpendicular (orthogonal) to the horizontal plane will be referred to as the "vertical direction", the direction from the smoke detector 100 toward the ceiling will be referred to as "upward", and vice versa. is explained as "downward". The arrows indicating the "vertical direction" in the drawings are only shown for explanation and have no substance. However, these directions are not intended to limit the usage direction (installation direction) of the smoke detector 100.

Further, each of the drawings described below schematically represents the configuration of the smoke detector 100, and various dimensional relationships and the like in the drawings may differ from the actual product.

The smoke detector 100 includes a housing 1, a sensing block 2, and a sound output section 5, as shown in FIGS. 1 and 2. Moreover, in this embodiment, the smoke detector 100 further includes a circuit block 4 and a battery B1. The battery B1 is not necessarily included in the components of the smoke detector 100, and the battery B1 does not need to be included in the components of the smoke detector 100.

The housing 1 is disk-shaped and circular in plan view. The housing 1 is a molded product made of synthetic resin. The housing 1 has a main body 10, a first cover 11, and a second cover 12. The housing 1 is constructed by combining the first cover 11 and the second cover 12 with the main body 10. The second cover 12 is fixed to the construction surface (here, the ceiling surface 200 (see FIG. 5)). However, strictly speaking, the second cover 12 is not directly fixed to the construction surface, but is indirectly fixed to the construction surface by being fixed to a mounting base that is fixed to the construction surface.

The main body 10 is composed of a bottom wall 101 and a peripheral wall 102. The bottom wall 101 is circular in plan view and has a first through hole 104, a second through hole 105, and multiple (here, three) insertion holes 106. The first through hole 104 penetrates the bottom wall 101 in the thickness direction (vertical direction) and has the same circular shape as the outer shape of the sensing case 21 of the sensing block 2 in plan view. The sensing case 21 of the sensing block 2 is inserted into the first through hole 104 from below. The second through hole 105 penetrates the bottom wall 101 in the thickness direction (vertical direction) and has the same rectangular shape as the outer shape of the battery case 114 in plan view. The battery case 114 is inserted into the second through hole 105 from below. Each insertion hole 106 penetrates the bottom wall 101 in the thickness direction (vertical direction) and has a circular shape in plan view. When the first cover 11 and the second cover 12 are combined with the main body 10, each insertion hole 106 faces the corresponding first boss 111 (described later) of the first cover 11 and the corresponding screw hole 121 (described later) of the second cover 12.

The peripheral wall 102 includes a wall that protrudes from the outer periphery of the upper surface of the bottom wall 101 so as to increase in diameter upward, and a wall that protrudes from the outer periphery of the lower surface of the bottom wall 101 so as to increase the diameter downward. It consists of A plurality of (here, 12) openings 103 are provided in the peripheral wall 102 in the circumferential direction. Each opening 103 has a rectangular shape that is elongated in the circumferential direction of the peripheral wall 102 when viewed from the front, and penetrates the peripheral wall 102 in the thickness direction (radial direction). Each opening 103 connects the internal space of the housing 1 with the outside of the housing 1. Therefore, smoke can flow into the internal space of the casing 1 from the outside of the casing 1 through each opening 103. In the present embodiment, the internal space of the housing 1 is a space surrounded by the bottom wall 101, the peripheral wall 102, and the second cover 12 of the main body 10.

The first cover 11 has a disc shape that is circular in plan view, and has the same outer peripheral shape as the main body 10 in plan view. The first cover 11 includes a plurality of (here, three) first bosses 111, one second boss 112, an acoustic case 113, and a battery case 114. Further, in the first cover 11, the circuit block 4 is arranged in an area surrounded by a plurality of first bosses 111 and one second boss 112.

Each first boss 111 is a cylinder having a circular shape in a plan view, and is formed integrally with the first cover 11 so as to protrude upward from the upper surface of the first cover 11. Each first boss 111 is formed with a screw hole into which a first screw S1 is tightened. The second boss 112 is a cylindrical body having a circular shape in plan view, and is formed integrally with the first cover 11 so as to protrude upward from the upper surface of the first cover 11. The second boss 112 is formed with a screw hole into which the second screw S2 is tightened.

The acoustic case 113 is a cylindrical body having a circular shape in plan view, and is formed integrally with the first cover 11 so as to protrude upward from the upper surface of the first cover 11. The sound output section 5 is housed in the acoustic case 113. Furthermore, a sound hole is formed in the bottom surface of the acoustic case 113, passing through the first cover 11 in the thickness direction (vertical direction). Sound is output from the sound output unit 5 through this sound hole. Note that the sound hole is covered by a decorative plate provided on the lower surface of the first cover 11.

The battery case 114 is a rectangular box in plan view, and is formed integrally with the first cover 11 so as to protrude upward from the upper surface of the first cover 11. The battery case 114 houses a battery B1 that functions as a power source for operating the smoke detector 100. Battery B1 may be a primary battery or a secondary battery.

The second cover 12 has a disc shape that is circular in plan view, and has the same outer peripheral shape as the main body 10 in plan view. The second cover 12 has a plurality (here, three) of screw holes 121. Each screw hole 121 has a circular shape in plan view, and penetrates the second cover 12 in the thickness direction (vertical direction). A first screw S1 is inserted into each screw hole 121 from above the second cover 12.

The housing 1 is assembled as follows. First, the first cover 11 is assembled to the main body 10 so as to close the opening on the top surface of the main body 10. Next, the second cover 12 is assembled to the main body 10 so as to close the opening on the lower surface of the main body 10. Then, the plurality of insertion holes 106 of the main body 10, the plurality of corresponding first bosses 111 of the first cover 11, and the plurality of corresponding screw holes 121 of the second cover 12 are overlapped with each other. In this state, the main body 10, the first cover 11, and the second cover 12 are coupled to each other by inserting and tightening the plurality of first screws S1 from above the second cover 12 into the corresponding screw holes 121. .

The circuit block 4 includes a printed wiring board 41 and a plurality of electronic components including switches. A plurality of electronic components are mounted on printed wiring board 41. The light emitting section 22 and the light receiving section 23 of the sensing block 2 are electrically connected to the conductor section of the printed wiring board 41 . Further, the sound output section 5 and the battery B1 are further electrically connected to the conductor section of the printed wiring board 41.

The printed wiring board 41 is arranged below the sensing block 2, that is, between the sensing block 2 and the bottom wall 101 of the main body 10. The sensing block 2 is mounted on one surface (upper surface) of the printed wiring board 41 in the thickness direction. The printed wiring board 41 is provided with a through hole 42 that is circular in plan view and penetrates in the thickness direction (vertical direction). With the upper end of the second boss 112 of the first cover 11 inserted into the through hole 42, a second screw S2 whose shaft part passes through one end of the antenna 43 is inserted from above and tightened. Thereby, the antenna 43 is fixed and electrically connected to the printed wiring board 41. The antenna 43 is part of a communication module mounted on the printed wiring board 41 that performs wireless communication with other devices (for example, other smoke detectors, etc.).

Here, the circuit block 4 includes a control circuit composed of multiple electronic components. The control circuit is a circuit that controls the light emitting unit 22, the light receiving unit 23, the sound output unit 5, etc., and drives at least the light emitting unit 22 and performs signal processing on the output signal of the light receiving unit 23. In signal processing, the circuit block 4 judges the presence or absence of smoke in the sensing space Sp1 by comparing the amount of light received by the light receiving unit 23 (the magnitude of the output signal) with a threshold value. The amount of light received by the light receiving unit 23 varies depending on, for example, the concentration of smoke in the sensing space Sp1 and the type of smoke (white smoke, black smoke, etc.). Therefore, the circuit block 4 judges that "smoke is present" when smoke of a certain concentration or more is present in the sensing space Sp1 by comparing with the threshold value. When the circuit block 4 detects an amount of light received that is equal to or greater than a certain amount, it outputs an electrical signal to the sound output unit 5 to drive the sound output unit 5.

The sound output section 5 receives the electrical signal from the circuit block 4 and outputs sound (sound wave). The sound output section 5 is realized by a speaker, a buzzer, or the like that converts an electrical signal into sound. The sound output section 5 has a disk shape that is circular in plan view. The sound output section 5 is driven according to the state of the smoke detector 100. Specifically, the smoke detector 100 outputs a sound from the sound output unit 5 when detecting at least a certain amount of received light.

The sensing block 2 includes a sensing case 21, a light emitting section 22, and a light receiving section 23. The sensing case 21 has a disk shape that is circular in plan view. The sensing case 21 is a molded product made of synthetic resin, and has at least light blocking properties. The peripheral wall 211 of the sensing case 21 is provided with a plurality of window holes 212 extending in the circumferential direction of the sensing case 21 and having a rectangular shape when viewed from the front and penetrating the peripheral wall 211 in the thickness direction (radial direction). Therefore, smoke can flow from the outside of the sensing case 21 into the internal space of the sensing case 21 (that is, the sensing space Sp1) through the plurality of window holes 212. The sensing case 21 also houses a light emitting section 22 and a light receiving section 23.

In this embodiment, a labyrinth structure is provided inside the sensing case 21. The labyrinth structure is an assembly of a plurality of small pieces arranged in an annular shape inside the sensing case 21 so as to surround the sensing space Sp1 in the circumferential direction of the sensing case 21. The labyrinth structure allows smoke to be taken into the sensing space Sp1 from outside the sensing case 21 through gaps between the plurality of small pieces.

The sensing block 2 senses smoke present in the sensing space Sp1 within the sensing case 21. That is, the sensing block 2 is housed in the internal space of the casing 1, that is, the space surrounded by the bottom wall 101, the peripheral wall 102, and the second cover 12 of the main body 10. Since the interior space of the housing 1 is connected to the outside of the housing 1 through the opening 103 as described above, smoke can flow into the interior space of the housing 1 through the opening 103. The sensing block 2 takes in smoke that has flowed into the internal space of the housing 1 from the outside 9 of the sensing case 21 through the plurality of window holes 212 and the labyrinth structure into the sensing space Sp1. This allows the sensing block 2 to detect smoke.

The smoke detector 100 according to this embodiment configured as described above is included, for example, as a component of an automatic fire alarm system. In addition to the smoke detector 100, the automatic fire alarm system includes, for example, a receiver that receives an alarm signal (fire signal) from the smoke detector 100, and a push button for operating a push button when a person discovers a fire. It is equipped with a transmitter, etc. In an automatic fire alarm system, for example, when the smoke detector 100 detects the occurrence of a fire (smoke), the smoke detector 100 transmits an alarm signal (fire signal) to the receiver to notify the receiver of the occurrence of a fire. be done.

Here, the smoke detector 100 further includes a suppression structure 3. As already mentioned, the suppression structure 3 has the function of suppressing at least the invasion of a specific insect A1 into the sensing space Sp1. In this embodiment, the suppression structure 3 is a structure that suppresses a specific insect A1 that has entered the internal space of the housing 1 from entering the sensing space Sp1. Specifically, the suppression structure 3 is an insect repellent net 31 having a mesh having a width of 0.25 mm or less.

The insect net 31 has a rectangular shape when viewed from the front. The insect screen 31 is attached to the peripheral wall 211 inside the sensing case 21 so as to cover the plurality of window holes 212 . In this embodiment, all the window holes 212 are covered with a plurality of (here, two) insect screens 31. The insect screen 31 has a large number of rectangular meshes 311, as shown in FIG. Both the first width W1 and the second width W2 of each mesh 311 are 0.25 mm or less. Note that when the mesh 311 is circular, its width (diameter) may be 0.25 mm or less. Furthermore, all the meshes 311 of the insect repellent net 31 may not have the above dimensions, and some of the meshes 311 may have dimensions larger than the above dimensions.

Hereinafter, the advantages of the insect repellent net 31 of this embodiment will be explained with a comparison with an insect repellent net of a comparative example. The insect repellent net of the comparative example differs from the insect repellent net 31 of the present embodiment in that both the first width and the second width of the mesh are larger than 0.25 mm. As an example, in the insect repellent net of the comparative example, both the first width and the second width of the mesh are 0.3 mm. The comparative insect screen prevents insects whose maximum width is more than 0.3 mm from passing through (hereinafter also referred to as "common insects"), thereby preventing common insects from entering the sensing space. is prevented. Here, the specific insect A1 has a characteristic that if at least the head can pass through the mesh, the entire body can pass through the mesh. Therefore, even if the maximum width of the body of a specific insect A1 is larger than the first width and second width of the mesh of the comparative insect screen, the specific insect A1 will be There is a possibility that the insects may pass through the insect screen of the comparative example and enter the sensing space Sp1. In other words, the insect screen of the comparative example has a problem in that even if it can suppress the invasion of general insects into the sensing space Sp1, it cannot completely suppress the invasion of specific insects A1 into the sensing space Sp1.

In contrast, in the insect repellent net 31 of this embodiment, the width of the mesh 311 (first width W1 and second width W2) is 0.25 mm or less. That is, the size of the mesh 311 of the insect repellent net 31 of this embodiment is such that the head of the specific insect A1 cannot pass through. Therefore, in this embodiment, since the head of the specific insect A1 is difficult to pass through the mesh 311 of the insect net 31, it is also difficult for the entire body of the insect A1 to pass through the insect net 31. As a result, the insect repellent net 31 of the present embodiment has the advantage that it is easier to suppress the entry of specific insects A1 into the sensing space Sp1 than the insect repellent net of the comparative example.

(3) Summary As described above, in this embodiment, the smoke detector 100 includes the suppression structure 3 that suppresses the invasion of specific insects A1 into the sensing space Sp1. Therefore, the suppression structure 3 can reduce the possibility that a specific insect A1 will invade the sensing space Sp1. For example, assume that a specific insect A1 has moved into the internal space of the housing 1 through the opening 103 of the housing 1 by being carried by the wind or crawling on the ceiling surface 200. . In this case, a situation may occur in which the specific insect A1 crawls on the bottom wall 101 of the housing 1 and heads toward the sensing block 2 (that is, the sensing space Sp1), but even in such a situation, the suppression structure 3 (insect control net 31) can reduce the possibility that a specific insect A1 will invade the sensing space Sp1.

Therefore, in this embodiment, since the possibility that a specific insect A1 exists in the sensing space Sp1 can be reduced, the possibility that the light from the light emitting part 22 is reflected and scattered by the specific insect A1 is also reduced. can do. In other words, in this embodiment, it is possible to reduce the possibility that scattered light due to the specific insect A1 will reach the light receiving unit 23, so the possibility of false detection due to the specific insect A1 can be reduced. It has the advantage of being easy.

(4) Modifications The embodiment described above is just one of various embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved. Modifications of the above embodiment will be listed below. The modified examples described below can be applied in combination as appropriate. Further, in a modification described below, the smoke detector 100 may have an insect screen of a comparative example instead of the insect screen 31. Furthermore, in the modified example described below, the smoke detector 100 does not need to have either the insect screen 31 or the insect screen of the comparative example.

(4.1) Modification 1
The smoke detector 100 of the first modification is different from the smoke detector 100 of the above embodiment in that it includes a wall body 32 as the suppression structure 3, as shown in Figs. 4 and 5. The wall body 32 is rod-shaped in a front view and protrudes upward from the upper surface of the bottom wall 101 of the main body 10. In this modification, the wall body 32 is curved so as to follow the circumferential direction of the housing 1 in a plan view. As an example, the height (vertical dimension) of the wall body 32 is higher than the height of the specific insect A1 crawling on the bottom wall 101. In addition, the wall body 32 is provided in the area between the sensing block 2 and the opening 103 on the upper surface of the bottom wall 101. In other words, the suppression structure 3 includes the wall body 32. The wall body 32 is provided in the area between the opening 103 and the sensing space Sp1 inside the housing 1, and protrudes from the bottom wall 101 of the housing 1.

Here, assume that a situation has arisen in which a specific insect A1 has entered the internal space of the housing 1 and is crawling along the bottom wall 101 of the housing 1 toward the sensing block 2 (i.e., the sensing space Sp1). In this situation, in this modified example, since a wall 32 is provided in the area between the opening 103 and the sensing space Sp1, the specific insect A1 cannot reach the sensing space Sp1 without climbing over the wall 32. For this reason, in this modified example, the wall 32 is expected to have the effect of reducing the possibility that the specific insect A1 will reach the sensing space Sp1.

Here, as shown in FIG. 6, there may be multiple (four here) walls 32. The multiple walls 32 are lined up in a direction from the opening 103 toward the sensing space Sp1 (the radial direction of the housing 1). In this embodiment, in the above situation, the specific insect A1 cannot reach the sensing space Sp1 unless it climbs over all of the walls 32. Therefore, in this embodiment, compared to when there is one wall 32, it is expected to have the effect of further reducing the possibility that the specific insect A1 will reach the sensing space Sp1.

(4.2) Modification 2
As shown in Fig. 7, the smoke detector 100 of the second modification differs from the smoke detector 100 of the first modification in that the wall body 32 has a return portion 321. Fig. 7 and Figs. 8 and 9 described below are enlarged cross-sectional views of a portion (a portion including the wall body 32) of the bottom wall 101 of the main body 10. The return portion 321 is formed by the tip (upper end) of the wall body 32 protruding toward the opening 103. The amount of protrusion is, for example, higher than the height of a specific insect A1 crawling on the surface of the wall body 32 (the dimension in the left-right direction in Fig. 7).

In this modified example, even if the specific insect A1 crawls on the surface of the wall body 32 in an attempt to get over the wall body 32, it cannot reach the sensing space Sp1 unless it overcomes the return portion 321 against gravity. Then, when the specific insect A1 is crawling on the surface of the return portion 321, it is expected that the specific insect A1 will fall from the return portion 321. Therefore, in this embodiment, it is expected that the effect of further reducing the possibility of the specific insect A1 reaching the sensing space Sp1 can be achieved compared to a case in which the wall body 32 does not have the return portion 321.

As shown in FIG. 8, the return portion 321 may be formed so that the cross-sectional area increases (i.e., widens) from the bottom wall 101 toward the upper end. Even in this embodiment, it is expected to have the effect of further reducing the possibility of a specific insect A1 reaching the sensing space Sp1, compared to a case in which the wall body 32 does not have the return portion 321.

In the example shown in FIG. 8, the return portion 321 is provided on both sides of the wall body 32 when viewed from the front (the left and right sides in FIG. 8), but this is not limited to this embodiment. For example, the return portion 321 may be provided only on the opening 103 side (the left side of the wall body 32 in FIG. 8) of the both sides.

(4.3) Modification 3
The smoke detector 100 of the third modification is different from the smoke detector 100 of the first modification in that the tip (upper end) of the wall body 32 has a shape pointed upward, as shown in FIG. The tip of the wall 32 has a shape in which the angle θ formed by the two sides when viewed from the front is an acute angle. Further, the upper surface of the tip of the wall body 32 has an area that is such that a specific insect A1 cannot crawl thereon.

In this modification, even if a specific insect A1 crawls on the surface of the wall 32 in an attempt to climb over the wall 32, it can be expected that the insect will lose its posture at the tip of the wall 32 and fall. Therefore, in this aspect, compared to the case where the tip of the wall body 32 is not sharp, it can be expected that the effect of further reducing the possibility that the specific insect A1 will reach the sensing space Sp1 can be expected.

(4.4) Modification 4
As shown in FIG. 10, the smoke detector 100 of Modification 4 differs from the smoke detector 100 of the above-described embodiment in that it includes a region 33 (hatched region in FIG. 10) as the suppression structure 3. It differs from In other words, the restraining structure 3 includes the region 33 . The region 33 is a region between the sensing block 2 and the opening 103 on the upper surface of the bottom wall 101, that is, a region between the opening 103 and the sensing space Sp1 inside the housing 1. The region 33 is coated with a repellent that repels a specific insect A1, or is kneaded into the material that constitutes the housing 1 itself. The "repellent" in the present disclosure may include a drug containing a component that causes death of the specific insect A1, as well as a drug containing a component that is disliked by the specific insect A1.

Here, assume that a situation has arisen in which a specific insect A1 has entered the internal space of the housing 1 and is crawling along the bottom wall 101 of the housing 1 toward the sensing block 2 (i.e., the sensing space Sp1). In this situation, in this modified example, the presence of the area 33 to which the repellent is applied makes it difficult for the specific insect A1 to enter the area 33, or makes it more likely that the specific insect A1 will die if it does enter. For this reason, in this modified example, the area 33 is expected to have the effect of reducing the possibility that the specific insect A1 will reach the sensing space Sp1. The repellent may be applied to the insect screen 31, or may be kneaded into the material that constitutes the insect screen 31.

Here, as shown in FIG. 10, the inhibition structure 3 may have region 34 instead of region 33. The area occupied by region 34 is the same as the area occupied by region 33. In other words, region 34 is the area between the opening 103 and the sensing space Sp1 inside the housing 1. An adhesive material to which the specific insect A1 adheres is provided in region 34. In this embodiment, when the specific insect A1 enters region 34 in the above situation, the possibility that the specific insect A1 will be immobilized by the adhesive material can be increased. Therefore, in this embodiment, it is expected that region 34 will have the effect of reducing the possibility that the specific insect A1 will reach the sensing space Sp1.

(4.5) Modification 5
The smoke detector 100 of the fifth modification differs from the smoke detector 100 of the above-described embodiment in that it includes two projecting walls 35 as the suppression structure 3, as shown in FIG. The projecting wall 35 projects from each of the upper and lower edges of the opening 103 in the peripheral wall 102 of the main body 10 toward the outside of the housing 1 along the radial direction of the housing 1 . That is, the protruding wall 35 protrudes toward the outside of the housing 1 from the periphery of the opening 103 in the outer wall (peripheral wall 102) of the housing 1. Further, each projecting wall 35 is provided over the circumferential direction of the housing 1 . That is, each protruding wall 35 has an annular shape in plan view. The amount of protrusion of each projecting wall 35 is, for example, higher than the height (radial dimension of the housing 1) of the specific insect A1 crawling on the peripheral wall 102.

Here, a situation occurs in which a specific insect A1 crawls along the peripheral wall 102 of the housing 1 and heads toward the opening 103 by being carried by the wind or crawling on the ceiling surface 200. Assume that there is. In this situation, in this modification, since the projecting wall 35 is provided around the periphery of the opening 103, the specific insect A1 will pass through the opening 103 into the internal space of the casing 1 unless it climbs over the projecting wall 35. cannot be reached. That is, in this modification, the suppression structure 3 is a structure that suppresses the specific insect A1 from entering the sensing space Sp1 by suppressing the specific insect A1 from entering the inside of the housing 1. Therefore, in this modification, the projecting wall 35 can be expected to have the effect of reducing the possibility that the specific insect A1 will reach the sensing space Sp1.

(4.6) Other Modifications In the embodiments described above, the housing 1 may be made of a material that has chargeability. In other words, the suppression structure 3 may include the casing 1 made of a material that has chargeability. Here, it is assumed that a situation occurs in which a specific insect A1 crawls along the peripheral wall 102 of the housing 1 and heads toward the opening 103. In this situation, in this aspect, since the casing 1 is formed of a material that has an electrostatic property, a Coulomb force (electrostatic force) is generated between the casing 1 and the specific insect A1, and the specific insect A1 easily sticks to the casing 1. As a result, in this aspect, it becomes difficult for the specific insect A1 to enter the internal space of the housing 1 through the opening 103, and the effect of reducing the possibility that the specific insect A1 reaches the sensing space Sp1 can be expected. .

In the above-described modifications 1 to 3, the restraining structure 3 may be a labyrinth structure configured by combining a plurality of walls 32. This aspect can be expected to have the effect of reducing the possibility that the specific insect A1 that has entered the maze structure will reach the sensing space Sp1. Further, in this aspect, for example, by setting the exit of the maze structure at a location other than the sensing block 2, it is also possible to guide the specific insect A1 to a location different from the sensing space Sp1.

In the above-mentioned modifications 1 to 3, it is preferable that the wall 32 is formed of a material with a coefficient of friction small enough to allow the specific insect A1 to slide down. Similarly, in the fifth modification described above, the projecting wall 35 is preferably formed of a material with a coefficient of friction small enough to allow the specific insect A1 to slide down. In these aspects, when a specific insect A1 tries to climb over the wall 32 (or the projecting wall 35), it becomes easy to slide down, so an effect can be expected that makes it difficult for the insect to climb over the wall 32 (or the projecting wall 35).

In the above-described embodiment, the smaller the width of the mesh 311 of the insect screen 31, the more effective it can be expected to suppress intrusion of a specific insect A1 into the sensing space Sp1. However, the smaller the width of the mesh 311 of the insect screen 31, the more difficult it becomes for smoke to pass through the mesh 311, and there is a possibility that the function of taking smoke into the sensing space Sp1 may deteriorate. Considering the above points, it is preferable that the width of the mesh 311 of the insect screen 31 is about 0.2 mm. This aspect has the advantage that the function of suppressing entry of specific insects A1 into the sensing space Sp1 can be easily achieved without deteriorating the function of taking smoke into the sensing space Sp1.

In the above-described embodiment, the light-emitting unit 22 is not limited to a light-emitting diode, and may be, for example, an organic electroluminescence (EL) element or a laser diode (LD: Laser Diode). The light-receiving unit 23 is not limited to a photodiode, and may be, for example, a phototransistor.

(summary)
As described above, the smoke detector (100) according to the first aspect includes a housing (1), a photoelectric sensing block (2), and a suppression structure (3). The casing (1) has an opening (103) through which smoke can flow in from the outside. The sensing block (2) has a sensing space (Sp1) inside the housing (1) and detects smoke within the sensing space (Sp1). The suppression structure (3) suppresses at least the invasion of a specific insect (A1) into the sensing space (Sp1). The specific insect (A1) lacks the ability to fly by itself, so it moves by crawling or by riding the wind.

This has the advantage of making it easier to reduce the possibility of false detection.

In the smoke detector (100) according to the second aspect, in the first aspect, the suppression structure (3) includes an insect screen (31) having a mesh with a mesh width (311) of 0.25 mm or less.

This embodiment has the advantage that the movement of the specific insect (A1) into the detection space (Sp1) is restricted by the insect screen (31), making it difficult for the specific insect (A1) to enter the detection space (Sp1).

In the smoke detector (100) according to the third aspect, in the first or second aspect, the suppression structure (3) is provided in the area between the opening (103) inside the housing (1) and the sensing space (Sp1) and includes a wall body (32) protruding from the bottom wall (101) of the housing (1).

According to this aspect, by regulating the movement of a specific insect (A1) to the sensing space (Sp1) by the wall (32), it becomes difficult for the specific insect (A1) to invade the sensing space (Sp1). , there is an advantage.

In the smoke detector (100) according to the fourth aspect, in the third aspect, the wall bodies (32) are plural. The plurality of walls (32) are arranged in a direction from the opening (103) toward the sensing space (Sp1).

According to this aspect, since the specific insect (A1) cannot reach the sensing space (Sp1) unless it overcomes the plurality of walls (32), the specific insect (A1) is more likely to invade the sensing space (Sp1). It has the advantage of being less difficult.

In the smoke detector (100) according to the fifth aspect, in the third or fourth aspect, the wall (32) has a return portion (321) whose tip protrudes toward the opening (103).

According to this aspect, since the specific insect (A1) cannot reach the sensing space (Sp1) unless it overcomes the barbed part (321) against gravity, the specific insect (A1) can move closer to the sensing space (Sp1). It has the advantage of being difficult to infiltrate.

In the smoke detector (100) according to the sixth aspect, in any one of the first to fifth aspects, the suppression structure (3) includes an opening (103) inside the housing (1) and a sensing space ( Sp1) includes a region (33) where a repellent that repels a specific insect (A1) is applied or kneaded into the material itself constituting the casing (1).

According to this aspect, when the specific insect (A1) no longer approaches the area (33) or the specific insect (A1) that has invaded the area (33) dies, the specific insect (A1) There is an advantage that it becomes difficult to invade the sensing space (Sp1).

In the smoke detector (100) according to the seventh aspect, in any one of the first to sixth aspects, the suppression structure (3) includes an opening (103) inside the housing (1) and a sensing space ( Sp1) includes a region (34) provided with an adhesive material to which a specific insect (A1) adheres.

According to this aspect, since the movement of a specific insect (A1) that has invaded the area (34) can be blocked, there is an advantage that it becomes difficult for the specific insect (A1) to invade the sensing space (Sp1). .

In the smoke detector (100) according to the eighth aspect, in any one of the first to seventh aspects, the suppressing structure (3) includes a casing (1) made of a material that has chargeability.

This embodiment has the advantage that the specific insect (A1) sticks to the housing (1) due to Coulomb force (electrostatic force), making it difficult for the specific insect (A1) to enter the sensing space (Sp1).

In the smoke detector (100) according to the ninth aspect, in any of the first to eighth aspects, the suppression structure (3) includes a protruding wall (35) that protrudes from the periphery of the opening (103) in the outer wall (peripheral wall (102)) of the housing (1) toward the outside of the housing (1).

According to this aspect, since the specific insect (A1) cannot reach the inside of the casing (1) unless it climbs over the projecting wall (35), it is difficult for the specific insect (A1) to invade the sensing space (Sp1). It has the advantage of being.

The configurations according to the second to ninth aspects are not essential to the smoke detector (100) and can be omitted as appropriate.

100 Smoke detector 1 Housing 101 Bottom wall 102 Peripheral wall (outer wall)
103 Opening 2 Sensing block 3 Suppression structure 31 Insect screen 311 Mesh 32 Wall 321 Return portion 33, 34 Area 35 Projection wall A1 Specific insect Sp1 Sensing space

Claims (8)

A housing having an opening through which smoke can flow in from the outside;
A photoelectric sensing block having a sensing space inside the housing and detecting smoke in the sensing space;
and a suppression structure for suppressing the intrusion of at least a specific insect into the sensing space,
The suppression structure includes a wall provided in a region between the opening and the sensing space inside the housing and protruding from a bottom wall of the housing.
Smoke detectors. The wall bodies are plural,
The plurality of walls are arranged in a direction from the opening toward the sensing space.
The smoke detector according to claim 1. The wall body has a return portion whose tip protrudes toward the opening.
The smoke detector according to claim 1 or 2. a casing having an opening through which smoke can flow in from the outside;
a photoelectric sensing block having a sensing space inside the housing and detecting smoke within the sensing space;
a suppression structure that suppresses entry of specific insects into at least the sensing space;
The suppressing structure includes the casing made of a material that has chargeability.
Smoke detectors. a casing having an opening through which smoke can flow in from the outside;
a photoelectric sensing block having a sensing space inside the housing and detecting smoke within the sensing space;
a suppression structure that suppresses entry of specific insects into at least the sensing space;
The suppressing structure includes a protruding wall that protrudes from the periphery of the opening in the outer wall of the casing toward the outside of the casing.
Smoke detectors. The containment structure includes an insect screen having a mesh with a mesh width of 0.25 mm or less.
The smoke detector according to any one of claims 1 to 5. The suppressing structure includes a repellent that repels the specific insects applied between the opening and the sensing space inside the casing, or a repellent that is kneaded into the material itself constituting the casing. including areas where
The smoke detector according to any one of claims 1 to 6. The suppression structure includes an area provided with an adhesive material to which the specific insect adheres between the opening and the sensing space inside the casing.
The smoke detector according to any one of claims 1 to 7.

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