JP7787935B2 - sensor - Google Patents

Description

The present invention relates to fire detectors (hereinafter referred to as detectors), such as heat detectors and smoke detectors that detect heat and smoke during a fire, and in particular to detectors equipped with speakers.

Conventional detectors have been proposed that include a head cover attached to the bottom of the housing and a speaker housed in the head cover (see, for example, Patent Document 1). The head cover of the smoke detector in Patent Document 1 is a bottomed, cylindrical member with a bottom surface and a peripheral wall. The peripheral wall of the head cover has an air window through which smoke can pass, and the bottom of the head cover has a sound vent hole through which sound waves generated by the speaker can pass.

Japanese Patent Application Laid-Open No. 2005-352932 (for example, paragraphs 0066-0069 and FIG. 7)

In Patent Document 1, sound waves generated by vibrations of the speaker's underside (front surface) pass through sound holes in the bottom surface of the head cover and propagate into the living space, while sound waves generated by vibrations of the speaker's top surface (back surface) pass through air windows in the peripheral wall of the head cover and propagate into the living space. Here, the sound waves generated by vibrations of the speaker's underside and the sound waves generated by vibrations of the speaker's top surface are out of phase with each other. As a result, the sound waves propagating into the living space through the air windows in the peripheral wall of the head cover are weakened by the sound waves propagating into the living space through sound holes in the bottom surface of the head cover. Therefore, when the speaker in the smoke detector of Patent Document 1 generates sound, the range in which a certain level of sound pressure can be maintained is narrowed.

The present invention was made to solve the above-mentioned problems, and aims to provide a detector that can expand the range in which sound pressure can be maintained at a certain level or higher.

The detector of the present invention comprises a housing with a cylindrical side portion and an opening through which smoke can flow; a fire detection unit located within the housing for detecting smoke and heat; a speaker located within the housing for emitting sound when the fire detection unit detects smoke or heat; and a plate-shaped partition member located within the housing that separates a first space, which is a passageway from the opening to the fire detection unit, from a second space in which the speaker is located. The partition member has an opening, and the housing is configured so that sound waves from the speaker radiated from the second space to the first space through the opening propagate toward the opening. The housing has a flat, plate-shaped opposing surface that faces the partition member. The opposing surface faces the portion of the partition member where the opening is formed, and has a reflective surface that reflects sound waves and propagates them toward the opening.

The detector according to the present invention has the above configuration, which makes it possible to expand the range in which sound pressure can be maintained above a certain level.

1 is a diagram showing the appearance of a smoke detector 100 according to an embodiment. FIG. 2 is an exploded perspective view of the components of the smoke detector 100. 1A shows a cross section of the first cover 11 taken along the line AA shown in FIG. 1B is a cross-sectional view taken along the line BB in FIG. 4. The base portion 3 and the lid portion 4 are shown at the DD end faces shown in FIG. 1(a) is a cross-sectional view taken along the line CC shown in FIG. 1 shows a modified example (smoke detector 101) of the smoke detector 100 according to the embodiment.

Embodiment
Hereinafter, an embodiment of a sensor according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below. Also, the size relationships of the components in the following drawings, including FIG. 1, may differ from the actual size relationships.

Figure 1 is a diagram showing the appearance of a smoke detector 100 according to an embodiment. Figure 1(a) is a side view showing the appearance of the smoke detector 100, and Figure 1(b) is a bottom view showing the appearance of the smoke detector 100. Figure 2 is a perspective view showing the components of the smoke detector 100 in an exploded state. Figure 3 shows a cross section of the first cover 11 taken along line A-A in Figure 1(a). Figure 4 is a cross section of the first cover 11 taken along line B-B in Figure 1(b). The configuration of the smoke detector 100 will be described with reference to Figures 1 to 4.

The smoke detector 100 is installed in a monitored space, such as the interior of a house. As shown in FIG. 1, the smoke detector 100 is attached to the ceiling 200, for example. As shown in FIGS. 1 and 2, the smoke detector 100 includes a housing 10 including a cylindrical first cover 11 with a bottom and a second cover 12 that serves as a lid for the first cover 11. As shown in FIGS. 2 and 4, the smoke detector 100 includes a partition member 30 housed in the housing 10 and dividing the space within the housing 10 into upper and lower sections, and a fire detection unit Det provided in the partition member 30. The fire detection unit Det includes a darkroom section Drm with a light-blocking function and a light-receiving unit and a light-emitting unit on a substrate 6, which will be described later. The darkroom section Drm includes an optical bench cover 5 housed in the housing 10 and with a light-blocking function, a labyrinth wall Lb housed in the optical bench cover 5 and with a light-blocking function, and an optical bench 4A6 formed on the lid section 4, which will be described later. As shown in Figures 2 and 4, the smoke detector 100 includes a circuit board 6 housed in a partition member 30, a battery 7 that supplies operating power to the various circuits provided on the circuit board 6, and a speaker 8 that is housed in the partition member 30 and produces sound. Furthermore, as shown in Figure 2, the smoke detector 100 includes a push-in member 20 that is provided on the first cover 11 and that is pushed by an inspector when inspecting the smoke detector 100.

1(a) and 2, an opening 1 extending in the circumferential direction is formed in the first cover 11 of the housing 10. A plate-shaped partition member 1a is provided in the opening 1 of the housing 10. The opening 1 has an upper opening 1A and a lower opening 1B. The upper opening 1A is provided above the partition member 1a, and the lower opening 1B is provided below the partition member 1a. The first cover 11 has a flat opposing surface portion 11A and a cylindrical side surface portion 11B. The opposing surface portion 11A has an opening 11A1 that is closed by a push-in member 20. As shown in FIGS. 1 and 3, the opposing surface portion 11A has an outer surface Sf1 that serves as a design surface, and an inner surface Sf2 that is the back surface of the outer surface Sf1 and faces the partition member 30. 2 and 3, the facing surface 11A includes a circular recess 11A2 in which the lid portion 5A of the optical bench cover 5 is disposed, and a support portion 11A3 in which the shaft portion 21 of the pushing member 20 is disposed. The facing surface 11A also includes guide plates a1-a4 that guide smoke that has flowed into the housing 10 from the opening 1 to the optical bench cover 5, and cylindrical insertion portions b into which screws inserted into each insertion portion 3B1 are fastened.

The recessed portion 11A2 is recessed from the base portion 3 toward the opposing surface portion 11A to prevent interference with the optical bench cover 5. The side surface portion 11B includes main ribs 13 extending vertically, sub-ribs 14 extending vertically between adjacent main ribs 13, and a cylindrical portion 15 located on the periphery of the partition member 30. The lower ends of the main ribs 13 are connected to the opposing surface portion 11A, and the upper ends of the main ribs 13 are connected to the cylindrical portion 15. The sub-ribs 14 are thinner than the main ribs 13. The lower ends of the sub-ribs 14 are connected to the opposing surface portion 11A, and the upper ends of the sub-ribs 14 are connected to the cylindrical portion 15. The central angle at the center O1 of a pair of adjacent main ribs 13 is 90 degrees. Here, the opposing surface portion 11A has a circular shape in a plan view, and the center O1 corresponds to the center of the opposing surface portion 11A. Eight sub-ribs 14 are formed on the first cover 11. The central angle between a pair of adjacent sub-ribs 14 at their centers O1 is 30 degrees. The tubular portion 15 is a member that surrounds the partition member 30 and can be configured, for example, in a cylindrical shape. The second cover 12 is provided on top of the first cover 11.

Introduction plates a1 to a4 protrude from the opposing surface portion 11A toward the partition member 30. Introduction plates a1 and a2 are arranged parallel to the longitudinal direction of the battery 7. Introduction plates a3 and a4 are arranged radially around the recessed portion 11A2. As shown in FIG. 3, an imaginary plane passing through the centers O2 and O1 of the recessed portion 11A2 is referred to as plane Pr. One portion of the smoke detector 100 divided by plane Pr is referred to as region Rg1, and the other portion of the smoke detector 100 divided by plane Pr is referred to as region Rg2. A battery accommodating portion 3C and a battery 7 are provided on plane Pr. Region Rg1 contains introduction plate a1, a speaker hole forming portion 4A1, a speaker 8, and other components. Introduction plates a2 and a3 are provided in region Rg2. Nine introduction plates a4 are provided. Four introduction plates a4 are provided in region Rg1, four introduction plates a4 are provided in region Rg2, and one introduction plate a4 is provided on surface Pr.

An opening 11A1 is formed in the opposing surface 11A, but the rest of the surface is closed. The opening 11A1 is also closed by a push-in member 20. As shown in Figures 2 and 3, the opposing surface 11A has a reflecting surface Rf located below the speaker hole 4A8. The reflecting surface Rf is included in the inner surface Sf2. The reflecting surface Rf reflects sound waves from the speaker 8 and propagates the sound waves radially from the speaker hole 4A8 side toward the opening 1 side. No holes are formed in the reflecting surface Rf. In other words, no speaker hole is formed in the first cover 11. This contributes to improving the aesthetic appearance of the smoke detector 100's design. It also has the effect of preventing the insertion or intrusion of foreign objects.

As shown in FIG. 2, the partition member 30 comprises a base portion 3 having a wall portion 3A and a lid portion 4 covering the circuit board 6 and speaker 8. A smoke detection space 3A3 is formed inside the wall portion 3A of the base portion 3. The base portion 3 comprises an annular edge portion 3B, a recessed battery housing portion 3C that houses a battery 7, and a recessed speaker housing portion 3D that houses a speaker 8. The base portion 3 also comprises a circuit board placement portion 3E on which the circuit board 6 is provided, and a support portion 3F formed on the edge portion 3B and protruding toward the opposing surface portion 11A. The circuit board 6 is provided around the periphery of the wall portion 3A. The edge portion 3B is provided along the inner circumferential surface of the tubular portion 15 of the first cover 11. The edge portion 3B is formed with two insertion portions 3B1 into which screws (not shown) are inserted to secure the base portion 3 and the first cover 11. The battery housing section 3C has a partition wall 3E1 that separates the side where the battery 7 is located from the side where the circuit board 6 is provided. The battery 7 is located on the upper side of the battery housing section 3C. The speaker housing section 3D is a wall that surrounds the speaker 8. The speaker housing section 3D is formed in an arc shape. The base section 3 also has a surface section 3D1 that faces the top surface of the speaker 8. The circuit board placement section 3E faces the edge of the circuit board 6. The support section 3F rotatably supports the shaft section 21 of the pushing member 20.

As shown in FIG. 2, the lid 4 includes a lid body 4A, a flange 4B attached to the edge of the lid body 4A, and a columnar guide member 4C that guides smoke that has flowed into the housing 10 from the opening 1 to the optical base cover 5. The lid body 4A includes a plate-shaped speaker hole forming portion 4A1 in which a speaker hole 4A8 is formed, a wall portion 4A2 formed around the periphery of the speaker hole forming portion 4A1, a wall portion 4A3 (described later in FIG. 5), and an insertion portion 4A4 into which a screw (not shown) provided in one of the two insertion portions 3B1 is inserted. The lid body 4A also includes an LED hole 4A5 exposing an LED (not shown) on the circuit board 6 that lights up when the switch 6A on the circuit board 6 is pressed, an optical base 4A6 on which the optical base cover 5 is attached, a speaker hole 4A8 through which sound waves generated by the speaker 8 pass, and a switch hole 4A9 into which the switch 6A on the circuit board 6 is inserted. As shown in Figure 4, the optical bench 4A6 has a through-hole 4A7 that connects the darkroom section Drm with the smoke detection space 3A3.

The optical bench cover 5 is a bowl-shaped member. It is provided on the opposing surface 11A of the first cover 11 and comprises a lid-shaped portion 5A attached to the lid portion 4, and a cylindrical mesh portion 5B with multiple holes through which smoke can pass. The lid-shaped portion 5A and mesh portion 5B have a light-blocking function similar to the labyrinth wall Lb. The mesh portion 5B also prevents dust, insects, etc. from entering the darkroom portion Drm.

The substrate 6 is arranged parallel to the horizontal direction. As shown in FIG. 2, the substrate 6 is provided with a light-emitting section, which may be composed of an LED or the like, and a light-receiving section that receives light from the light-emitting section. The substrate 6 is also provided with a shielding case 6B that protects the circuitry of the light-receiving section. Furthermore, the substrate 6 is formed with an optical system arrangement section 6C, which is a cutout formed to match the peripheral shape of the wall section 3A of the base section 3. The above-mentioned light-emitting section and light-receiving section are provided in the optical system arrangement section 6C.

As shown in FIG. 2, the speaker 8 is provided between the base 3 and the lid 4. Specifically, the speaker 8 is housed by the speaker housing 3D of the base 3, the surface 3D1 of the base 3, and the speaker hole forming portion 4A1 of the lid 4. A diaphragm is provided on the underside of the speaker 8.

As shown in Figures 2 and 3, the pushing member 20 includes a rotatable shaft portion 21 sandwiched between the support portion 3F of the base portion 3 and the support portion 11A3 of the opposing surface portion 11A of the first cover 11, and a pushing surface portion 22 connected to the shaft portion 21 and closing the opening 11A1 of the first cover 11.

Figure 5 shows the D-D end faces of the base portion 3 and the lid portion 4 shown in Figure 4. The configuration of the smoke detector 100 will be explained further with reference to Figure 5. The wall portion 3A has a hole 3A1 through which the light-emitting portion for smoke detection faces, a hole 3A2 through which the light-receiving portion for smoke detection faces, and a protrusion 3A4 that constantly prevents light from the light-emitting portion from entering the light-receiving portion. A smoke detection space 3A3 is formed inside the wall portion 3A. The smoke detection space 3A3 is connected to the darkroom portion Drm described above.

A wall portion 4A2 of the lid portion 4 is provided around the speaker housing portion 3D. Furthermore, a wall portion 4A3 of the lid portion 4 is provided around the wall portion 3A and the board placement portion 3E. Although the wall portion 4A3 is hidden and not visible in Figure 2, as already explained, it is formed on the back side of the surface on which the optical bench 4A6 is formed.

As shown in FIG. 4, a first space SP1 is formed within the housing 10, which is a passageway for smoke from the opening 1 to the optical base cover 5. Also, as shown in FIG. 2, a second space SP2 in which a speaker 8 is provided is formed within the housing 10. The second space SP2 is provided above the first space SP1. The first space SP1 and the second space SP2 are separated vertically by the speaker hole forming portion 4A1.

Figure 6 is a cross-sectional view taken along the line CC shown in Figure 1(a). Next, the operation of the smoke detector 100 will be described with reference to Figure 6 and the above-mentioned Figures 1 to 5. When a fire or other incident occurs, smoke flows into the first space SP1 through the opening 1 in the housing 10. The smoke that flows into the first space SP1 is guided by the guide plate a1 or the like to the optical bench cover 5 of the darkroom section Drm of the fire detection unit Det. The smoke that reaches the periphery of the optical bench cover 5 then flows into the space within the optical bench cover 5 (the darkroom section Drm of the fire detection unit Det) through the holes in the mesh section 5B. The smoke that flows into the space within the optical bench cover 5 passes through the labyrinth wall Lb and then flows into the through-hole 4A7 in the lid section 4. The smoke that flows into the through-hole 4A7 flows into the smoke detection space 3A3. Note that the smoke contains fine particles. These particles are heavier than smoke and therefore do not rise easily. As a result, these particles remain on the optical bench cover 5, and smoke flows into the smoke detection space 3A3. This improves the fire detection accuracy of the smoke detector 100. When smoke flows into the smoke detection space 3A3, the light from the light-emitting element of the substrate 6 is scattered in the smoke detection space 3A3. The light-receiving element of the substrate 6 detects this scattered light, allowing the smoke detector 100 to detect a fire.

When the light receiving section of the substrate 6 detects this scattered light, the control circuit of the substrate 6 causes the speaker 8 to generate sound. When the speaker 8 generates sound, the diaphragm of the speaker 8 vibrates. As the diaphragm of the speaker 8 vibrates, the diaphragm of the speaker 8 generates sound waves, which are compressional waves. The sound waves generated by the speaker 8 propagate through the air and pass through the speaker hole 4A8. A portion of the sound waves that pass through the speaker hole 4A8 are reflected by the reflecting surface Rf of the opposing surface portion 11A. As shown in FIG. 6, the sound waves Sw reflected by the reflecting surface Rf of the opposing surface portion 11A propagate radially from the speaker hole 4A8 side toward the opening 1 side. The remaining portion of the sound waves that pass through the speaker hole 4A8 are diffracted by the speaker hole 4A8 and then propagate, for example, directly to the opening 1, or propagate to the opening 1 while being reflected by the partition member 30 or the opposing surface portion 11A.

The sound waves Sw that reach the opening 1 spread radially from the smoke detector 100 as the center. Furthermore, the sound waves Sw that reach the opening 1 are diffracted at the opening 1 and also propagate below the smoke detector 100. Furthermore, the sound waves generated on the upper surface of the speaker 8's diaphragm are in opposite phase to the sound waves generated on the lower surface of the speaker 8's diaphragm, but the sound waves generated on the upper surface of the speaker 8's diaphragm are attenuated by vibrating the surface portion 3D1, etc. Therefore, the sound waves generated on the upper surface of the speaker 8's diaphragm are prevented from attenuating the sound waves generated on the lower surface of the speaker 8's diaphragm.

Next, the effects of the embodiment will be explained. The housing 10 of the smoke detector 100 is configured so that sound waves Sw emitted from the speaker hole 4A8 into the first space SP1 propagate from the speaker hole 4A8 side to the opening 1 side. In other words, the sound waves Sw that pass through the speaker hole 4A8 are reflected by the housing 10, and the reflected sound waves Sw propagate radially from the speaker hole 4A8 side to the opening 1 side, and the sound waves Sw that reach the opening 1 spread radially with the smoke detector 100 as their center. Therefore, when the speaker 8 generates sound, the smoke detector 100 can expand the range over which a certain level of sound pressure can be maintained.

Furthermore, as explained in the operation of the smoke detector 100, sound waves generated on the underside of the diaphragm of the speaker 8 are prevented from being attenuated by sound waves generated on the upper surface of the diaphragm of the speaker 8. Therefore, the smoke detector 100 can further expand the range in which a certain level of sound pressure can be maintained when the speaker 8 generates sound.

The opposing surface portion 11A of the smoke detector 100 faces the portion of the partition member 30 where the speaker hole 4A8 is formed, and has a reflecting surface Rf that reflects sound waves Sw emitted from the speaker hole 4A8 into the first space SP1 and propagates the sound waves Sw toward the opening 1. The reflecting surface Rf is a closed surface with no holes formed therein so that it can effectively reflect the sound waves Sw. In other words, the reflecting surface Rf more reliably reflects sound waves propagating from the speaker hole 4A8 and more reliably propagates them toward the opening 1.

Because the facing surface 11A of the smoke detector 100 is a flat plate-shaped member, the outer surface Sf1 of the facing surface 11A, i.e., the design surface, is flat. Because the design surface of the facing surface 11A of the smoke detector 100 is flat, the smoke detector 100 has an excellent aesthetic appearance. Furthermore, because the facing surface 11A of the smoke detector 100 is a flat plate-shaped member, sound waves Sw emitted from the speaker hole 4A8 into the first space SP1 are reflected by the facing surface 11A and more reliably reach the opening 1. Therefore, the smoke detector 100 easily spreads sound waves radially from the smoke detector 100 as the center, and the smoke detector 100 is more effective in expanding the range in which a certain level of sound pressure can be maintained when the speaker 8 generates sound.

Furthermore, although an opening 11A1 is formed in the facing surface 11A of the smoke detector 100, it is blocked by the push-in member 20. Therefore, there are no open areas on the facing surface 11A of the smoke detector 100. Therefore, even though the smoke detector 100 is provided with the opening 11A1 and the push-in member 20, etc., to make it easier to inspect the smoke detector 100, the smoke detector 100 still has the aforementioned effects of excellent aesthetics and the effect of expanding the range in which a certain level of sound pressure can be maintained.

Figure 7 shows a modified example (smoke detector 101) of the smoke detector 100 according to the embodiment. In this modified example, the vertical relationship between the first space SP1 and the second space SP2 is reversed from that in the embodiment. In other words, the first space SP1 is located above the second space SP2. The configuration of the smoke detector 101 according to the modified example will now be described.

The smoke detector 101 comprises a housing 71, a partition member 74 separating the first space SP1 and the second space SP2, an optical base cover 75 provided on the partition member 74, a circuit board 76 provided below the partition member 74, and a speaker 78 provided below the partition member 74. The housing 71 houses the partition member 74, the optical base cover 75, the circuit board 76, and the speaker 78. The housing 71 comprises a cylindrical side portion 71b having an opening 71A formed therein, an opposing surface portion 71a provided above the partition member 30, and a flat design surface 71c. A reflective surface Rf is formed on the underside of the opposing surface portion 71a.

The partition member 74 includes a flat speaker hole forming portion 74A and an optical base 74C on which an optical base cover 75 is provided. A speaker hole 74B is formed in the speaker hole forming portion 74A. The optical base cover 75 includes a lid-shaped portion 75A facing the opposing surface portion 71a and a cylindrical mesh portion 75B with multiple holes through which smoke passes. The optical base cover 75 also includes a labyrinth wall 75C with a light-blocking function. The optical base cover 75, labyrinth wall 75C, and optical base 74C form the darkroom portion Drm. The board 76 includes a light-emitting portion 76A composed of an LED or the like and a light-receiving portion 76B composed of a light-receiving element or the like. Two holes are formed in the partition member 74, and the light-emitting portion 76A and the light-receiving portion 76B face the darkroom portion Drm through these two holes. A speaker 78 is located directly below the speaker hole forming portion 74A.

Although not shown in Figure 7, the smoke detector 101 also includes a battery. In a modified example, the partition member 74 may have a configuration corresponding to the battery storage section 3C of the partition member 30. Also, in a modified example, the battery can be placed in the second space SP2.

The smoke detector 101 according to the modified example has the same effect as the smoke detector 100 according to the embodiment. While the above description has been given using the example of a smoke detector as the detector, this is not limiting. The configurations of the embodiment and modified example can also be applied to a heat detector. A heat detector is a detector that detects the occurrence of a fire by the heat generated when a fire occurs. For example, in the case of a differential heat detector, the fire detection unit corresponds to a thermistor or other similar configuration, and in the case of a constant temperature heat detector, the fire detection unit corresponds to a bimetal or other similar configuration.

In the embodiment, an example is described in which the first space SP1 and the second space SP2 are separated vertically by a partition member 30, and in the modified example, an example is described in which the first space SP1 and the second space SP2 are separated vertically by a partition member 74. In other words, in the embodiment and modified example, an example is described in which the first space SP1 and the second space SP2 are separated vertically, but this is not limited to a vertical separation. Detectors that are not separated vertically, such as sensors separated horizontally or diagonally by a partition member, can also be used, and even sensors in which a single space is divided into two or more spaces can achieve the same effects as those in the embodiment and modified example.

1 Opening, 1A Upper opening, 1B Lower opening, 1a Partition member, 3 Base portion, 3A Wall portion, 3A1 Hole portion, 3A2 Hole portion, 3A3 Smoke detection space, 3A4 Protrusion portion, 3B Edge portion, 3B1 Insertion portion, 3C Battery storage portion, 3D Speaker storage portion, 3D1 Surface portion, 3E Board placement portion, 3E1 Partition wall, 3F Support portion, 4 Lid portion, 4A Lid main body, 4A1 Speaker hole forming portion, 4A2 Wall portion, 4A3 Wall portion, 4A4 Insertion portion, 4A6 Optical base, 4A7 Through hole, 4A8 Speaker hole, 4A9 Switch hole, 4B Flange portion, 4C Introduction member, 4D5 LED hole, 5 Optical base cover, 5A Lid-shaped portion, 5B Mesh portion, 6 Board, 6A Switch, 6B Shield case, 6C optical system arrangement portion, 7 battery, 8 speaker, 10 housing, 11 first cover, 11A opposing surface portion, 11A1 opening, 11A2 concave portion, 11A3 support portion, 11B side portion, 12 second cover, 13 main rib, 14 sub-rib, 15 cylindrical portion, 20 pushing member, 21 shaft portion, 22 pushing surface portion, 30 partition member, 71 housing, 71A opening, 71a opposing surface portion, 71b side portion, 71c design surface, 74 partition member, 74A speaker hole forming portion, 74B speaker hole, 74C optical base, 75 optical base cover, 75A lid-shaped portion, 75B mesh portion, 75C labyrinth wall, 76 substrate, 76A light-emitting portion, 76B light-receiving portion, 78 Speaker, 100 smoke detector, 101 smoke detector, 200 ceiling, Det fire detection section, Drm darkroom section, Lb labyrinth wall, O1 center, O2 center, Pr surface, Rf reflecting surface, Rg1 area, Rg2 area, SP1 first space, SP2 second space, Sf1 outer surface, Sf2 inner surface, Sw sound wave, a1 introduction plate, a2 introduction plate, a3 introduction plate, a4 introduction plate, b insertion section.

Claims (2)

a housing having a cylindrical side portion with an opening through which smoke flows;
a fire detection unit provided in the housing and configured to detect smoke and heat;
a speaker provided in the housing, which generates a sound when the fire detection unit detects smoke or heat;
a plate-shaped partition member provided in the housing, which partitions a first space that is a passage from the opening to the fire detection unit and a second space in which the speaker is provided;
Equipped with
An opening is formed in the partition member,
the housing is configured so that sound waves from the speaker radiated from the second space to the first space through the opening propagate toward the opening,
the housing has a flat-plate-shaped opposing surface portion facing the partition member,
The opposing surface portion faces the portion of the partition member where the opening is formed, and has a reflective surface that reflects the sound waves and propagates them toward the opening. a housing having an opening formed on a side thereof through which smoke can flow;
a fire detection unit provided in the housing and configured to detect smoke and heat;
a speaker provided in the housing, which generates a sound when the fire detection unit detects smoke or heat;
a partition member provided in the housing, the partition member separating a first space that is a passage from the opening to the fire detection unit and a second space in which the speaker is provided;
Equipped with
An opening is formed in the partition member,
The housing is configured so that sound waves emitted from the speaker into the first space from the opening propagate toward the opening.