Fire alarm, spraying pollution self-checking method and fire alarm system

Abstract

The invention provides a fire alarm, a spraying pollution self-checking method and a fire alarm system. The fire alarm comprises a bottom shell, a surface shell, a button and a sounder. The face shell is installed on the bottom shell, a through hole is formed in the face shell, the button is arranged in the through hole in a pressing mode, the sounder is installed on the side, facing the bottom shell, of the face shell, and a sounding hole is formed in the sounder; wherein a sound producing gap is formed between the hole wall surface of the through hole and the outer peripheral surface of the button, and the sound producing gap is communicated with the sound producing hole. The sounder of the fire alarm can make a sound by means of the gap between the button and the face shell, no sound hole needs to be additionally arranged, the design cost and the processing cost are reduced, the risk that pollutants enter the alarm main body can be reduced, and the alarm effect of the fire alarm is improved.

Description

Technical Field

[0001] This invention relates to the field of fire alarm technology, and in particular to a fire alarm device, a fire alarm system including the fire alarm device, and a self-inspection method for spray contamination of the fire alarm device. Background Technology

[0002] A fire alarm is a fire alarm device that monitors the concentration of smoke in the environment in real time through photoelectric or ion sensing principles and issues an audible and visual alarm in the early stages of a fire. As the front-end sensing node of a building fire protection system, it is easy to install and has a sensitive response. It has become a basic fire early warning device that is required to be equipped in homes, shopping malls, warehouses and industrial sites, providing critical golden time for personnel evacuation and fire fighting.

[0003] In related technologies, fire alarms have buttons on their casings to activate functions such as testing the fire alarm. The casings also have sound holes, and a buzzer is installed inside the fire alarm at the position corresponding to the sound holes to enable the fire alarm to sound. However, the installation of sound holes increases the structural design and manufacturing costs, and also increases the risk of contaminant intrusion. Summary of the Invention

[0004] In view of the above problems, the present invention provides a fire alarm in which the sounder can emit sound through the gap between the button and the front cover, eliminating the need for additional sound outlets, reducing design and manufacturing costs, and reducing the risk of contaminants entering the main body of the alarm, thereby improving the alarm effect of the fire alarm.

[0005] In a first aspect, according to an embodiment of the present application, the fire alarm includes a bottom shell, a front shell, a button, and a sounder. The front shell is mounted on the bottom shell and has a through hole. The button is pressably disposed in the through hole. The sounder is mounted on the side of the front shell facing the bottom shell and has a sound-emitting hole. A sound-emitting gap is formed between the wall surface of the through hole and the outer peripheral surface of the button, and the sound-emitting gap communicates with the sound-emitting hole.

[0006] According to the fire alarm according to the embodiments of this application, the sounder can use the sound gap formed between the button and the front cover as a sound outlet. The sound of the sounder is emitted from the sound outlet and propagates to the outside of the fire alarm through the sound gap, so as to realize the sound alarm of the fire alarm. There is no need to open a sound outlet on the front cover, which reduces the design cost and processing cost of designing a sound outlet according to the location of the sounder, and reduces the connection structure between the inside and outside of the alarm body, reducing the risk of dust entering the alarm body.

[0007] In some embodiments, the sound generator includes a bracket and a buzzer plate. The bracket is mounted on the side of the front shell facing the bottom shell. A resonant cavity is formed inside the bracket. A sound-emitting hole is disposed on the bracket and communicates with the resonant cavity. The buzzer plate is mounted on the bracket and closes the opening of the resonant cavity away from the sound-emitting hole.

[0008] In the above embodiments, the installation of the sound generator can be realized and the sound output effect of the sound generator can be ensured.

[0009] In some embodiments, an indicator light is also included, which is disposed inside the bottom housing; the bracket is a transparent component, a portion of which extends between the wall of the through hole and the outer peripheral surface of the button, and is disposed opposite to the indicator light.

[0010] In the above embodiments, the sound generator can be used for both sound generation and light guiding, offering multi-functional integration at a low cost.

[0011] In some embodiments, the bracket includes a base plate and a first light guide portion. The first light guide portion is disposed on the surface of the base plate away from the bottom shell. The first light guide portion is located between the hole wall surface of the through hole and the outer peripheral surface of the button. The first light guide portion extends circumferentially along the button and has opposite ends. The opposite ends of the first light guide portion are spaced apart to form a sound emission gap.

[0012] In the above embodiments, the bracket can be used for sound resonance or for guiding light, so as to realize the sound and light alarm of the fire alarm.

[0013] In some embodiments, the bracket further includes a sound-concentrating part and a base plate; the sound-concentrating part is disposed on the surface of the base plate opposite to the bottom shell, and the sound-concentrating part is disposed around the sound-emitting hole.

[0014] In the above embodiments, the sound emitted from the sound-emitting hole can be integrated through a sound-concentrating part to improve the sound alarm effect of the fire alarm.

[0015] In some embodiments, the bracket further includes a sound-focusing part; the sound-focusing part is disposed on the surface of the base plate away from the bottom shell, the sound-focusing part is disposed around the sound-emitting hole, the shape of the sound-focusing part is configured as a ring, the two ends of the first light guide part are connected to the outer peripheral surface of the sound-focusing part, and the sound outlet gap is located inside the sound-focusing part. In the above embodiments, both the sound-emitting function of the fire alarm and the triggering function of the button can be taken into account.

[0016] In some embodiments, the bracket further includes a sound-concentrating part; the sound-concentrating part is disposed on the surface of the base plate away from the bottom shell, the sound-concentrating part is disposed around the sound-emitting hole, the shape of the sound-concentrating part is constructed to be arc-shaped, and the two ends of the sound-concentrating part are connected to the outer peripheral surface of the first light guide part along the circumference of the sound-concentrating part.

[0017] In the above embodiments, both the sound-emitting function of the fire alarm and the triggering function of the button can be taken into account.

[0018] In some embodiments, the side of the face shell that is away from the bottom shell is the first surface, and the side of the first light guide that is away from the bottom shell is the second surface; The second surface is flush with the first surface, or the second surface protrudes from the bottom shell relative to the first surface.

[0019] In some embodiments, the control panel is also provided with a light emitter and a light receiver; The bracket also includes a second light guide section, which is disposed on the surface of the base plate facing the bottom shell. The light emitter and the light receiver are both disposed opposite to the second light guide section and are separated from each other.

[0020] In the above embodiments, the cooperation of the light emitter, the light receiver, and the second light guide can detect whether the bracket is contaminated by spray coating, thereby improving the reliability of use.

[0021] In some embodiments, a smoke guide plate is also included, which is installed between the bottom shell and the top shell and has a light inlet channel and a light outlet channel, with a light emitter disposed in the light inlet channel and a light receiver disposed in the light outlet channel.

[0022] In the above embodiments, the light transmitter and the light receiver are physically isolated by the light input channel and the light output channel, so as to prevent the light from the light transmitter from being directly received by the light receiver, which would affect the accuracy of the detection.

[0023] In some embodiments, the second light guide includes a light inlet pin and a light outlet pin, wherein the light inlet pin extends into the light inlet channel and the light outlet pin extends into the light outlet channel.

[0024] In the above embodiments, the accuracy of the fire alarm's coating self-test can be improved, thereby increasing its reliability.

[0025] In some embodiments, the fire alarm also includes a partition disposed within the base housing and between the light emitter and the light receiver, the partition being configured to block the light beam emitted by the light emitter to the light receiver.

[0026] In the above embodiments, a partition is used to physically block the light emitter and the light receiver, preventing the light from the light emitter from being directly received by the light receiver, which would affect the accuracy of the detection.

[0027] In some embodiments, the bracket is provided with a resilient arm, which is configured to drive the button to reset.

[0028] In the above embodiments, ease of use is improved, and the structure is integrated into the bracket, reducing space occupation.

[0029] In some embodiments, in the radial projection of the first light guide portion, the two end edges of the first light guide portion gradually move away from each other in the direction from the sound hole to the shell to form a horn-shaped structure.

[0030] In the above embodiments, the sound output effect of the speaker can be improved.

[0031] In some embodiments, the bracket includes a base plate and a third light guide, the third light guide being disposed on the surface of the base shell facing the point, and the third light guide being disposed opposite to the indicator light.

[0032] In some embodiments, the sound-emitting hole and the sound-emitting gap are arranged opposite each other along the axial direction of the sound-emitting hole.

[0033] In the above embodiments, the sound emitted by the transmitter can be transmitted directly through the sound outlet gap, the sound transmission path is simple, and sound attenuation is avoided, which would result in a weak alarm effect.

[0034] In a second aspect, according to an embodiment of this application, the fire alarm includes a bottom shell, a front shell, a button, an indicator light, and a sounder. The front shell is mounted on the bottom shell and has a through hole. The button is pressably disposed in the through hole, and the indicator light is disposed in the bottom shell. The sounder includes a bracket and a buzzer. The bracket is mounted on the side of the front shell facing the bottom shell, and the buzzer is mounted on the bracket. The bracket is a transparent part and has a light guide portion that extends between the hole wall surface of the through hole and the outer peripheral surface of the button, and is disposed opposite to the indicator light.

[0035] In a third aspect, according to the fire alarm according to the embodiments of this application, the fire alarm includes a bottom shell, a light emitter, a light receiver, a front shell, a button, and a bracket. The light emitter and the light receiver are both disposed inside the bottom shell, the front shell is installed on the bottom shell, the front shell is provided with a through hole, the button is pressably disposed in the through hole, the bracket is a transparent part, the bracket includes a base plate, a first light guide part and a second light guide part, the base plate is installed on the side of the front shell facing the bottom shell, the first light guide part is disposed on the surface of the base plate facing away from the bottom shell and extends to the space between the hole wall surface of the through hole and the outer peripheral surface of the button, the second light guide part is disposed on the surface facing the bottom shell, the light emitter and the light receiver are both disposed opposite to the second light guide part, and the light emitter and the light receiver are spaced apart from each other.

[0036] In a fourth aspect, a self-inspection method for spray coating contamination of a fire alarm device used in the above embodiments includes: Control the light emitter to emit light; The fire alarm is determined to be contaminated by spray paint based on changes in the electrical signal received from the optical receiver.

[0037] In a fifth aspect, the fire alarm system according to the embodiments of this application includes the fire alarm device of the foregoing embodiments, and the fire alarm device includes a plurality of fire alarm devices that are interconnected.

[0038] Other features and advantages disclosed in this application will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the above-described technology disclosed in this application.

[0039] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of a fire alarm in some embodiments of this application.

[0041] Figure 2 This is an exploded view of a fire alarm device in some embodiments of this application.

[0042] Figure 3 yes Figure 2 An enlarged view of part B in the embodiment.

[0043] Figure 4 yes Figure 1 A partial structural cross-sectional view (including the button, faceplate, and speaker) cut along section AA in the embodiment.

[0044] Figure 5 yes Figure 4 Exploded view of an embodiment.

[0045] Figure 6 yes Figure 1 A partial structural cross-sectional view (including the bracket and smoke guide plate) cut along section AA in the embodiment.

[0046] Figure 7 yes Figure 1 A partial structural cross-sectional view (including brackets and buttons) cut along section AA in the embodiment.

[0047] Figure 8 This is a schematic diagram (top view) of the bracket in some embodiments of this application.

[0048] Figure 9 This is a schematic diagram (bottom view) of the bracket in some embodiments of this application.

[0049] Figure 10 This is a schematic diagram of a smoke guide plate, a smoke sensor, and an indicator light in some embodiments of this application.

[0050] Figure 11 This is a bottom view of the smoke guide plate in some embodiments of this application.

[0051] The reference numerals in the detailed embodiments are as follows: Fire alarm 100, base shell 10; Control board 20, control switch 21, light transmitter 22, light receiver 23; Smoke guide plate 30, light inlet channel 31, light outlet channel 32, smoke guide cavity 33, lamp cover 34, channel 35, partition 36; Faceplate 40, through hole 41, first surface 42, first slot 43; Button 50, second card slot 51; The components include: a sound generator 60, a bracket 61, a base plate 611, a resonant cavity 6111, an elastic arm 6112, a first locking protrusion 6113, a second locking protrusion 6114, a first light guide 612, a second surface 6121, a sound focusing part 613, a second light guide 614, a light inlet pin 6141, a light outlet pin 6142, a sound hole 615, a positioning post 617, a third light guide 616, and a buzzer 62. Sound outlet gap 70, indicator light 80, smoke sensor 90. Detailed Implementation

[0052] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0053] In related technologies, fire alarms have buttons on their casings to activate functions such as testing. The casings also have sound outlets, and a buzzer is located inside the fire alarm at the corresponding position to trigger an audible alarm. However, the inventors discovered that to achieve an audible alarm, a dedicated sound outlet needs to be added to the casing. This requires additional design and manufacturing, and the added sound outlet also increases the risk of dust and other contaminants entering the alarm body, contaminating the internal smoke sensor, affecting the buzzer's decibel level, and thus impacting the alarm's effectiveness.

[0054] Therefore, the present invention provides a fire alarm 100 in which the sounder 60 can emit sound through the gap between the button 50 and the faceplate 40, without the need to add a sound outlet, reducing design and processing costs, and reducing the risk of pollutants entering the main body of the alarm, thereby improving the reliability and alarm effect of the fire alarm 100.

[0055] Among them, the appendix Figure 1 In this context, AA is the section symbol; cutting along the direction of AA yields the same result as... Figure 1Cross-sectional views related to the embodiments Figure 4 To the anatomical view Figure 6 Additionally, for clear demonstration Figure 2 The structure of part B is enlarged to a local magnification. Figure 3 .

[0056] Specifically, when the fire alarm 100 includes a smoke sensor, the fire alarm 100 is a smoke alarm. When the fire alarm 100 includes multiple fire sensors, the fire alarm 100 is a composite fire alarm. The fire sensors can be carbon monoxide sensors, temperature sensors, smoke sensors, etc.

[0057] Clearly, a composite fire alarm can include smoke sensors and other fire sensors. Furthermore, the smoke sensor 90 can specifically be a photoelectric smoke sensor.

[0058] Reference Figures 1 to 6 The fire alarm 100 of this application embodiment includes a base shell 10, a control board 20, a smoke guide plate 30, a front shell 40, a button 50, and a sounder 60. Obviously, in other embodiments of the fire alarm 100 without a smoke sensor, the smoke guide plate 30 may not be included, and the front shell 40 may be mounted on the base shell 10.

[0059] The base shell 10 can be understood as the supporting housing of the fire alarm 100. Most of the structural components of the fire alarm 100 can be installed on the base shell 10, which can be installed in the ceiling or in a pre-embedded box in the ceiling to realize the installation of the fire alarm 100. In addition, the front shell 40 can be directly installed on the base shell 10.

[0060] The control board 20 is a circuit board equipped with various electrical components. The control board 20 is housed within the base shell 10 and may include a control switch 21 and a smoke sensor 90. The control switch 21 can be used to activate functions such as testing and silencing the fire alarm 100. The smoke sensor 90 is used to detect the concentration of smoke entering the fire alarm 100. In one embodiment, the control board 20 is electrically connected to the control switch 21 and the smoke sensor 90 to realize the smoke detection and testing functions of the fire alarm 100.

[0061] A smoke guide plate 30 is mounted on the bottom shell 10. A smoke guide cavity 33 is formed within the smoke guide plate 30, and a first clearance hole and a second clearance hole are provided on the side of the smoke guide cavity 33 facing the control plate 20. A smoke sensor 90 can be accommodated within the smoke guide plate 30 through the first clearance hole. A smoke guide channel is provided on the peripheral wall of the smoke guide plate 30. The smoke guide channel connects the inner and outer spaces of the smoke guide plate 30 and is used to guide smoke flow to the smoke sensor 90, facilitating the detection of smoke concentration by the smoke sensor 90.

[0062] The pressing post on button 50 passes through or is housed in the second clearance hole and abuts against control switch 21 to trigger control switch 21. In addition, multiple mutually compatible pressing posts and multiple control switches 21 can be arranged at intervals along the circumference of button 50, so that button 50 can trigger functions such as test and mute regardless of the angle from which it is pressed.

[0063] The front cover 40 can be understood as a housing that covers the internal components of the fire alarm 100, used to conceal the internal components of the fire alarm 100. The front cover 40 and the bottom cover 10 constitute the main housing of the fire alarm 100. The front cover 40 is mounted on the smoke guide plate 30, and the front cover 40 is provided with a through hole 41. The shape of the through hole 41 can be circular, elliptical, or polygonal, etc., to adapt to the shape of the button 50.

[0064] Of course, the shape of the through hole 41 may not match the shape of the button 50, as long as the button 50 can be pressed. Specifically, there is a gap between the outer peripheral surface of the button 50 and the inner peripheral surface of the through hole 41, so that the button 50 can be pressed and positioned within the through hole 41. Alternatively, the button 50 can be polygonal in shape, and the through hole 41 can be circular in shape. In the projection along the axis of the through hole 41, there is a gap between the circumcircle of the polygonal button 50 and the inner peripheral surface of the through hole 41.

[0065] For ease of understanding, the following description assumes that both the through hole 41 and the button 50 are circular.

[0066] Button 50 is pressable within through hole 41 and is used to trigger control switch 21. For example, when button 50 is pressed, button 50 abuts against control switch 21 to trigger control switch 21.

[0067] The sound generator 60 serves as the sound source for the fire alarm 100, enabling the fire alarm 100 to emit a sound alarm. The sound generator 60 is installed on the side of the front cover 40 facing the bottom cover 10 and is electrically connected to the control board 20. The sound generator 60 has a sound-emitting hole 615 to emit sound.

[0068] It should be noted that the fire alarm 100 includes an alarm body and a mounting plate. The alarm body includes a base shell 10, a control panel 20, a smoke guide plate 30, a front shell 40, a button 50, and a sounder 60. The mounting plate can be directly installed on the ceiling or installed in a pre-embedded box in the ceiling, and the base shell 10 can be installed on the mounting plate to realize the installation of the fire alarm 100.

[0069] Based on the aforementioned related technologies, in order to reduce design and processing costs, and also to reduce the risk of dust entering the alarm body, an embodiment of this application forms a sound-emitting gap 70 between the wall surface of the through hole 41 and the outer peripheral surface of the button 50, and the sound-emitting gap 70 communicates with the sound-emitting hole 615. With this configuration, the sounder 60 can use the sound-emitting gap 70 formed between the button 50 and the housing 40 as a sound-emitting hole. The sound of the sounder 60 is emitted from the sound-emitting hole 615 and propagates to the outside of the fire alarm 100 through the sound-emitting gap 70, thus achieving sound alarm of the fire alarm 100. This eliminates the need to additionally open a sound-emitting hole on the housing 40, reducing the design and processing costs of designing a sound-emitting hole based on the location of the sounder 60, and reducing unnecessary communication channels between the alarm body and the outside world, thereby reducing the risk of dust entering the alarm body.

[0070] Understandably, in order to ensure that the speaker 60 can produce sound through the sound outlet gap 70, the relative position of the speaker 60 and the sound outlet gap 70 needs to be fixed, that is, the position of the speaker 60 relative to the faceplate 40 or the button 50 is fixed to ensure the sound output effect of the speaker 60.

[0071] Based on this, refer to Figure 2 , Figure 4 , Figure 5 and Figure 7 In some embodiments of this application, the sound generator 60 includes a bracket 61 and a buzzer 62.

[0072] The bracket 61 is installed on the side of the front shell 40 facing the bottom shell 10. A resonant cavity 6111 is formed inside the bracket 61. The sound-emitting hole 615 is set on the bracket 61 and communicates with the resonant cavity 6111. The buzzer 62 is installed on the bracket 61 and seals the opening of the resonant cavity 6111 away from the sound-emitting hole 615. In this way, the sound generator 60 can be installed and the sound output effect of the sound generator 60 can be ensured.

[0073] Specifically, the bracket 61 is mounted on the faceplate 40 and can be installed by means of adhesive, snap-fit, and / or fasteners. For example, the bracket 61 is constructed as an annular shape to fit the through hole 41. The bracket 61 can be correspondingly disposed on the periphery of the through hole 41, and the periphery of the through hole 41 is provided with a plurality of first slots 43 arranged at intervals. The outer periphery of the bracket 61 is provided with a plurality of first protrusions 6113 arranged at intervals. The plurality of first protrusions 6113 are engaged with the plurality of first slots 43 one by one to realize the installation of the sound generator 60. In addition, the button 50 is provided with a plurality of second slots 51 arranged at intervals in the circumferential direction, and the bracket 61 is provided with a plurality of second protrusions 6114 arranged at intervals in the circumferential direction. The plurality of second protrusions 6114 are engaged with the plurality of second slots 51 one by one to realize the assembly of the button 50 and the bracket 61.

[0074] Furthermore, a resonant cavity 6111 is formed inside the support 61. The sound-emitting hole 615 can be located at one end of the resonant cavity 6111 near the sound outlet gap 70, and the buzzer 62 can be located at the end of the resonant cavity 6111 away from the sound-emitting hole 615. Specifically, the resonant cavity 6111 can be formed by the base plate 611 extending away from the sound-emitting hole 615 at the relative position of the sound-emitting hole 615, and the resonant cavity 6111 is annular. When the alarm is triggered, the buzzer 62 can vibrate to generate sound waves. After the sound waves are resonated and amplified by the resonant cavity 6111, they are emitted through the sound-emitting hole 615, thereby realizing the sound output of the speaker 60.

[0075] Reference Figure 1 , Figure 2 , Figure 4 and Figure 5 In some embodiments of this application, the fire alarm 100 also includes an indicator light 80, which is capable of emitting a visible light beam. The indicator light 80 is disposed inside the bottom housing 10, specifically on the control panel 20. The bracket 61 is a transparent component, and a portion of the bracket 61 extends between the hole wall of the through hole 41 and the outer peripheral surface of the button 50, and is disposed opposite to the indicator light 80; thus, the sound generator 60 can be used for both sound generation and light guiding, achieving multi-functional integration and low cost.

[0076] In some examples, the bracket 61 may be made of transparent light guide materials such as PMMA (acrylic / plexiglass), PC (polycarbonate), PS (polystyrene).

[0077] Understandably, the control panel 20 is also equipped with an indicator light 80. The indicator light 80 is opposite to the bracket 61. Since the bracket 61 is a transparent part, the light emitted by the indicator light 80 can pass through the bracket 61 and be displayed outside the fire alarm 100, so as to realize the luminous alarm of the fire alarm 100.

[0078] Furthermore, referring to Figure 2 , Figures 4 to 6 In some embodiments of this application, the bracket 61 includes a base plate 611 and a first light guide 612. The base plate 611 can be used to receive the light emitted by the indicator light 80, and the first light guide 612 can guide the light received by the base plate 611 to the external environment.

[0079] The first light guide portion 612 is disposed on the surface of the base plate 611 facing away from the bottom shell 10. The first light guide portion 612 is located between the hole wall of the through hole 41 and the outer peripheral surface of the button 50. The first light guide portion 612 extends circumferentially along the button 50 and has two opposing ends. The opposing ends of the first light guide portion 612 are spaced apart to form a sound gap 70. In this way, the bracket 61 can be used for sound resonance and light guiding to realize the sound and light alarm of the fire alarm 100. At the same time, the first light guide portion 612 can also fill the gap between the through hole 41 and the button 50, reducing unnecessary communication channels between the alarm body and the outside world, and reducing the risk of environmental dust, flying insects, etc. entering the alarm body. Obviously, the first light guide portion 612 can have one or more opposing ends.

[0080] Understandably, both the base plate 611 and the first light guide 612 are transparent. The base plate 611 is positioned opposite the indicator light 80 on the control panel 20, and the first light guide 612 is located between the wall of the through hole 41 and the outer peripheral surface of the button 50. When the fire alarm 100 is activated, the indicator light 80 emits light towards the base plate 611. After passing through the base plate 611, the light enters the first light guide 612 and emits a luminous alarm signal to the external environment.

[0081] The first light guide portion 612 extends circumferentially along the button 50 and has two opposing ends along the circumferential direction. A predetermined distance is spaced between the opposing ends of the first light guide portion 612. A sound-emitting hole 615 can be formed on the base plate 611 and located between the two ends of the first light guide portion 612, while a sound-emitting gap 70 is formed between the two ends of the first light guide portion 612. This facilitates communication between the sound-emitting hole and the sound-emitting gap 70, enabling the fire alarm 100 to sound. Of course, the resonant cavity 6111 can be formed on the base plate 611, and the buzzer 62 can be mounted on the base plate 611.

[0082] The inner peripheral surface of the first light guide 612 can be adapted to the shape of the outer peripheral surface of the button 50, and the outer peripheral surface of the first light guide 612 can be adapted to the shape of the inner peripheral surface of the through hole 41.

[0083] Furthermore, in the radial projection of the first light guide 612, the two ends of the first light guide 612 gradually move away from each other in the direction from the sound hole 615 to the face shell 40 to form a horn-shaped structure, so as to improve the effect of sound alarm.

[0084] Additionally, multiple positioning posts 617 can be provided on the base plate 611. These positioning posts 617 can be arranged around the axis of the opening at the end of the resonant cavity 6111 away from the sound-emitting hole 615. During installation, the buzzer 62 can be constrained among the multiple positioning posts 617, ensuring that the buzzer 62 is aligned with the opening of the resonant cavity 6111. Subsequently, the buzzer 62 can be glued to the opening of the resonant cavity 6111 to seal the opening, thus completing the installation of the buzzer 62. After installation, the multiple positioning posts 617 are cut off to prevent interference between the positioning posts 617 and the buzzer 62.

[0085] Reference Figure 2 , Figure 4 and Figure 5 In some embodiments of this application, the bracket 61 further includes a sound-focusing part 613, which is disposed on the surface of the base plate 611 opposite to the bottom shell 10, and surrounds the sound-emitting hole 615. In this way, the sound emitted from the sound-emitting hole 615 can be focused by the sound-focusing part 613 to improve the sound alarm effect of the fire alarm 100.

[0086] There are various configurations for the sound-focusing part 613, all of which can improve the effectiveness of the audible alarm. In some embodiments of the sound-focusing part 613, a corresponding avoidance design can be added to prevent interference between the button 50 and the sound-focusing part 613. For ease of understanding, the following embodiments are provided for illustration.

[0087] In some embodiments of this application, the sound-focusing part 613 is configured in a ring shape, with both ends of the first light guide part 612 connected to the outer peripheral surface of the sound-focusing part 613, and the sound emission gap 70 located inside the sound-focusing part 613 to improve the effect of the audible alarm. Specifically, the sound-focusing part 613 is located in the inner space between the hole wall surface of the through hole 41 and the outer peripheral surface of the button 50, forming the sound emission gap 70.

[0088] Based on this structure, the annular sound-gathering part 613 partially overlaps with the pressing trajectory of some button 50 embodiments, which can easily lead to structural interference. Therefore, in some examples, to avoid interference between the button 50 and the sound-gathering part 613 when the button 50 triggers the control switch 21, the button 50 needs to avoid the sound-gathering part 613; that is, a clearance part is provided on the button 50. When the button 50 is pressed, the sound-gathering part 613 can be located within the clearance part, achieving clearance between the button 50 and the sound-gathering part 613; after the button 50 is released, the clearance part disengages from the sound-gathering part 613. Specifically, the annular sound-gathering part 613 can be circular, polygonal, or similar shapes.

[0089] In other examples, button 50 is pressed in the vertical direction. Therefore, the size of the portion of the sound-concentrating part 613 that overlaps with the pressing trajectory of button 50 can be reduced to achieve avoidance. That is, the sound-concentrating part 613 is located below button 50, and the height of the sound-concentrating part 613 is low, so that button 50 will not structurally interfere with the sound-concentrating part 613 throughout its entire stroke.

[0090] Reference Figure 2 , Figure 4 and Figure 5 In some other embodiments of this application, the sound-focusing part 613 is constructed in an arc shape and is arranged circumferentially along the sound-emitting hole 615, and the two ends of the sound-focusing part 613 are connected to the outer peripheral surface of the first light guide part 612 to improve the effect of sound alarm.

[0091] Based on this structure, since the button 50 is located inside the first light guide 612, and the arc-shaped sound focusing part 613 is connected to the outside of the first light guide 612, the pressing trajectory of the button 50 does not coincide with that of the arc-shaped sound focusing part 613. Therefore, when the button 50 is pressed, there will be no structural interference with the sound focusing part 613.

[0092] Reference Figure 2 and Figure 4 In some embodiments of this application, the side of the face shell 40 facing away from the bottom shell 10 is a first surface 42, and the side of the first light guide 612 facing away from the bottom shell 10 is a second surface 6121, with the second surface 6121 flush with the first surface 42. This arrangement ensures that the appearance of the first light guide 612 and the face shell 40 is flat, reduces interference between the first light guide 612 and external structures, and also ensures the light guiding effect of the first light guide 612.

[0093] In some other embodiments of this application, the second surface 6121 protrudes from the bottom shell 10 relative to the first surface 42. This arrangement allows the first light guide 612 to protrude outward relative to the top shell 40, increasing the surface area of ​​the first light guide 612 extending outside the fire alarm 100, making the light more conspicuous during the luminous alarm and improving the luminous alarm effect.

[0094] According to relevant standards, when the fire alarm 100 is contaminated with paint, it can obstruct smoke from entering the smoke sensor 90 and contaminate the smoke sensor 90 itself, severely affecting its smoke detection capability and reducing its alarm reliability, potentially causing it to malfunction or generate false alarms. Clearly, other types of fire alarms 100 will also be affected to some extent by paint contamination. Furthermore, paint contamination of the bracket 61 will also affect its luminous alarm alert function during a fire.

[0095] Reference Figure 3 and Figure 6 In some embodiments of this application, the control board 20 is further provided with a light emitter 22 and a light receiver 23; the bracket 61 also includes a second light guide 614, which is disposed on the surface of the base plate 611 facing the bottom shell 10. The light emitter 22 and the light receiver 23 are both disposed opposite to the second light guide 614 and are spaced apart from each other. The fire alarm 100 has a self-detection function for spray paint contamination, which can detect whether the fire alarm 100 is contaminated by spray paint.

[0096] The working principle of this paint contamination self-detection function or method is as follows: The light emitter 22 emits light to the second light guide 614. After the light is conducted inside the bracket 61, a portion is reflected back to the second light guide 614 and then received by the light receiver 23. When the bracket 61 is contaminated by paint, the light received by the light receiver 23 will change compared to when the bracket 61 is not contaminated. Therefore, after receiving the electrical signal from the light receiver 23, the control board 20 can determine whether the bracket 61 is contaminated by paint based on the change in the electrical signal, thereby determining whether the fire alarm 100 is contaminated by paint.

[0097] The control board 20 may also include a controller. The controller can be a microcontroller unit (MCU), which can perform functions such as program execution and logical judgment to implement smoke detection and testing functions. Clearly, the controller can also be used to implement a self-inspection function for spray paint contamination or to execute a self-inspection method for spray paint contamination.

[0098] More specifically, in some embodiments, the second surface 6121 of the first light guide 612 is flush with or protrudes from the first surface 42 of the housing 40. Furthermore, after the fire alarm 100 is installed on the ceiling, the housing 40 is away from the ceiling and faces outwards. Therefore, when the fire alarm 100 is contaminated by spray paint, both the housing 40 and the second surface 6121 of the first light guide 612 will be covered by the paint. When the paint contamination self-check function is activated, the control light emitter 22 emits light. This light is conducted through the second light guide 614 to the second surface 6121 of the first light guide 612. Because the second surface 6121 is covered by the paint, more of the light is reflected back to the second light guide 614, allowing the light receiver 23 to receive more light and feed back a stronger electrical signal to the control board 20. Obviously, this electrical signal can be a current signal or a voltage signal.

[0099] In one embodiment of the self-detection method for spray paint contamination, the control board 20 can determine whether the fire alarm 100 is contaminated by spray paint based on whether the intensity of the electrical signal received from the light receiver 23 reaches a first preset contamination value. In another embodiment of the self-detection method for spray paint contamination, the control board 20 first obtains an electrical signal difference based on the electrical signal received from the light receiver 23 and a preset background electrical signal, and then determines whether the fire alarm 100 is contaminated by spray paint based on whether the electrical signal difference reaches a second preset contamination value. Obviously, after the control board 20 receives the electrical signal fed back by the light receiver 23, there are other methods to determine whether the fire alarm 100 is contaminated by spray paint based on changes in the electrical signal.

[0100] Furthermore, the light emitter 22 and the light receiver 23 are separated from each other to prevent the light emitted by the light emitter 22 from being directly received by the light receiver 23, thus avoiding any impact on the accuracy of the self-test function. Additionally, the light emitter 22 and the light receiver 23 are arranged adjacent to each other so that the light receiver 23 can receive sufficient light to perform the self-test function; this light is emitted by the light emitter 22 and transmitted from the second light guide section 614 to the light receiver 23.

[0101] Therefore, by cooperating with the light emitter 22, the light receiver 23, and the second light guide 614, it is possible to detect whether the fire alarm 100 is contaminated by spray paint, ensuring that the reliability of the fire alarm and the light alarm function are not affected.

[0102] Furthermore, the light emitter 22 can emit visible light or invisible light, and this application does not limit this.

[0103] Furthermore, referring to Figure 6 In some embodiments of this application, the smoke guide plate 30 has a light inlet channel 31 and a light outlet channel 32. A light emitter 22 is disposed in the light inlet channel 31, and a light receiver 23 is disposed in the light outlet channel 32. The second light guide portion 614 includes a light inlet pin 6141 and a light outlet pin 6142. The light inlet pin 6141 extends into the light inlet channel 31, and the light outlet pin 6142 extends into the light outlet channel 32. Furthermore, the light inlet channel 31 and the light outlet channel 32 are spaced apart from each other at least at the light emitter 22 and the light receiver 23.

[0104] The light inlet channel 31 facilitates the light emitter 22 to direct the light source to the second light guide 614, and the light outlet channel 32 facilitates the second light guide 614 to direct the light to the light receiver 23. The light inlet channel 31 and the light outlet channel 32 achieve physical isolation between the light emitter 22 and the light receiver 23, preventing the light from the light emitter 22 from being directly received by the light receiver 23, which would affect the accuracy of the detection.

[0105] The light guide pin 6141 of the second light guide 614 can extend into the light guide channel 31, so that the light guide pin 6141 is closer to the light emitter 22; during detection, more light can be emitted towards the second light guide 614. The light guide pin 6142 can extend into the light guide channel 32, so that the light guide pin 6142 is closer to the light receiver 23; during detection, more light can be guided to the light receiver 23. In this way, the accuracy of the paint contamination self-test of the fire alarm 100 can be improved. In addition, by setting the light guide pin 6141 and the light guide pin 6142 in the light guide channel 31 and the light guide channel 32 respectively, the light guide pin 6141 and the light guide pin 6142 are separated from each other.

[0106] In some embodiments of this application, the fire alarm 100 further includes a partition 36 disposed within the bottom housing 10 and located between the light emitter 22 and the light receiver 23. The partition 36 is configured to block the light beam emitted directly from the light emitter 22 to the light receiver 23. Thus, the partition 36 physically isolates the light emitter 22 and the light receiver 23, preventing the light from the light emitter 22 from being directly received by the light receiver 23, thus avoiding any impact on detection accuracy. In one embodiment, the partition 36 may be disposed on the smoke guide plate 30. In another embodiment, the partition 36 is a common channel wall of adjacent light guide channels 31 and light outlet channels 32.

[0107] Reference Figure 2 , Figure 4 and Figure 5 In some embodiments of this application, the bracket 61 is provided with an elastic arm 6112, which is configured to drive the button 50 to reset, and the elastic arm 6112 is integrated into the bracket 61 to reduce space occupation.

[0108] For example, the elastic arm 6112 can be disposed on the base plate 611 of the bracket 61. The elastic arm 6112 is integrally formed with the base plate 611. The elastic arm 6112 itself can be constructed as an elastic structure, and the base plate 611 can also be provided with a second clearance groove, which corresponds to the elastic arm 6112. When the button 50 is pressed, the button 50 can trigger the control switch 21 and press against the free end of the elastic arm 6112. At this time, at least a portion of the elastic arm 6112 is pressed into the second clearance groove, providing sufficient space for the downward movement of the button 50. When the button 50 is released, the elastic arm 6112, under its own elastic force, drives the button 50 to return to its original position, and at the same time, the free end of the elastic arm 6112 disengages from the second clearance groove.

[0109] Reference Figure 2 , Figure 4 and Figure 5In some embodiments of this application, multiple elastic arms 6112 are provided, and the multiple elastic arms 6112 are arranged at intervals along the circumference of the button 50. This allows the button 50 to be pressed evenly and avoids structural jamming. Correspondingly, multiple second clearance grooves may be provided on the base plate 611, and the multiple second clearance grooves correspond one-to-one with the multiple elastic arms 6112.

[0110] Reference Figure 1 and Figure 2 In some embodiments of this application, the sound-emitting hole 615 is positioned opposite to the sound outlet gap 70 along the axial direction of the sound-emitting hole 615. Thus, the sound emitted by the sound generator 60 can be directly transmitted through the sound outlet gap 70, simplifying the sound transmission path and avoiding sound attenuation that could lead to a weak alarm effect.

[0111] Reference Figure 8 and Figure 9 In some embodiments of this application, the light guide portion includes at least one of a first light guide portion 612, a second light guide portion 614, and a third light guide portion 616. The first light guide portion 612, the sound focusing portion 613, the second light guide portion 614, the positioning post 617, and the third light guide portion 616 are all integrally formed with the base plate 611 of the bracket 61. This makes the bracket 61 compact, reliable in quality, easy to install, and improves production efficiency.

[0112] Specifically, the bracket 61 is a transparent part, and the structural parts formed on the bracket 61 can be used for light guiding. That is, the first light guiding part 612, the second light guiding part 614, the third light guiding part 616 and the base plate 611 have light guiding functions.

[0113] Reference Figures 9 to 11 In some embodiments of this application, the control board 20 is provided with an indicator light 80; the bracket 61 also includes a base plate 611 and a third light guide 616. The third light guide 616 is disposed on the surface of the base plate 611 facing the bottom shell 10 (i.e. facing the control board 20). The third light guide 616 is disposed opposite to the indicator light 80 and is used to guide the light beam emitted by the indicator light 80 to the outside of the fire alarm 100 to realize the indication function.

[0114] Furthermore, the control panel 20 is also equipped with a light emitter 22 and a light receiver 23, and the fire alarm 100 also includes a lampshade 34 and a channel 35; one end of the lampshade 34 can be fitted onto the indicator light 80, and the other end of the lampshade 34 is fitted onto the third light guide 616 to concentrate light and thus increase the light intensity incident on the third light guide 616.

[0115] One end of channel 35 can be fitted onto light emitter 22 and light receiver 23, and a partition 36 is provided inside channel 35. The partition 36 separates light emitter 22 and light receiver 23 to form light guide channel 31 and light exit channel 32. Light guide channel 31 and light exit channel 32 respectively serve to focus light, which can increase the electrical signal intensity of sprayed paint contaminants, thereby improving detection accuracy.

[0116] The lampshade 34, channel 35 and partition 36 are all integrally formed and installed on the smoke guide plate 30.

[0117] The fire alarm system according to the embodiments of this application includes the fire alarm 100 of the aforementioned embodiments. Multiple fire alarms 100 are interconnected and can communicate with each other to trigger mutual alarms in the event of a fire, thereby improving safety. The interconnection of the multiple fire alarms 100 can be wired and / or wireless.

[0118] For example, the office building is divided into multiple areas, and multiple fire alarms 100 can be installed in the corresponding areas. When a fire occurs in one area, the fire alarm 100 in the corresponding area detects that the smoke concentration is greater than or equal to a preset value, thereby triggering an alarm signal. At this time, the fire alarm 100 can issue an audible and visual warning to remind people in the area to evacuate. Since there is a risk of fire spreading, multiple fire alarms 100 can communicate with each other, so that the fire alarms 100 in other areas can also issue audible and visual warnings to ensure the safety of people in the office building.

[0119] In this application, the terms "installation," "setup," "equipped with," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or a point connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0120] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0121] In all embodiments of this application, "large" and "small" are relative terms, "more" and "less" are relative terms, and "upper" and "lower" are relative terms. The embodiments of this application will not elaborate further on the expression of such relative terms.

[0122] It should be understood that the phrases "in this embodiment," "in this application embodiment," or "as an optional implementation" throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, the phrases "in this embodiment," "in this application embodiment," or "as an optional implementation" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0123] In the various embodiments of this application, it should be understood that the sequence number of each process does not necessarily imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0124] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations, combinations, or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

Claims

1. A fire alarm device, characterized in that, include: Bottom shell (10); A face shell (40) is installed on the bottom shell (10), and the face shell (40) is provided with a through hole (41); A button (50) is pressably disposed within the through hole (41); A sound generator (60) is installed on the side of the face shell (40) facing the bottom shell (10), and the sound generator (60) has a sound hole (615) and a bracket (61), the sound hole (615) being disposed on the bracket (61); A sound-emitting gap (70) is formed between the wall surface of the through hole (41) and the outer peripheral surface of the button (50), and the sound-emitting gap (70) is connected to the sound-emitting hole (615).

2. The fire alarm device according to claim 1, characterized in that, The sound generator (60) also includes a buzzer (62), and the bracket (61) is mounted on the side of the face shell (40) facing the bottom shell (10); The bracket (61) has a resonant cavity (6111) inside, and the sound-emitting hole (615) is disposed on the bracket (61) and communicates with the resonant cavity (6111); The buzzer (62) is mounted on the bracket (61) and closes the opening of the resonant cavity (6111) away from the sound-emitting hole (615).

3. The fire alarm device according to claim 1, characterized in that, It also includes an indicator light (80), which is disposed inside the bottom shell (10); The bracket (61) is a transparent part, and a portion of the bracket (61) extends between the hole wall of the through hole (41) and the outer peripheral surface of the button (50), and is disposed opposite to the indicator light (80).

4. The fire alarm device according to claim 1, characterized in that, The bracket (61) includes a base plate (611) and a first light guide (612). The first light guide (612) is disposed on the surface of the base plate (611) away from the bottom shell (10). The first light guide (612) is located between the hole wall surface of the through hole (41) and the outer peripheral surface of the button (50). The first light guide (612) extends circumferentially along the button (50) and has opposite ends, the opposite ends of the first light guide (612) being spaced apart to form the sound outlet gap (70).

5. The fire alarm device according to claim 1, characterized in that, The bracket (61) further includes a sound-concentrating part (613) and a base plate (611); the sound-concentrating part (613) is disposed on the surface of the base plate (611) away from the bottom shell (10), and the sound-concentrating part (613) is disposed around the sound-emitting hole (615).

6. The fire alarm device according to claim 4, characterized in that, The bracket (61) further includes a sound-concentrating part (613); the sound-concentrating part (613) is disposed on the surface of the base plate (611) away from the bottom shell (10), and the sound-concentrating part (613) is disposed around the sound-emitting hole (615); The sound-gathering part (613) is constructed in an annular shape, and the two ends of the first light guide part (612) are connected to the outer peripheral surface of the sound-gathering part (613), and the sound outlet gap (70) is located on the inner side of the sound-gathering part (613); or, the sound-gathering part (613) is constructed in an arc shape, and the two ends of the sound-gathering part (613) are connected to the outer peripheral surface of the first light guide part (612).

7. The fire alarm device according to claim 4, characterized in that, The side of the face shell (40) facing away from the bottom shell (10) is the first surface (42), and the side of the first light guide (612) facing away from the bottom shell (10) is the second surface (6121). The second surface (6121) is flush with the first surface (42), or the second surface (6121) protrudes from the shell (40) relative to the first surface (42).

8. The fire alarm device according to claim 4, characterized in that, It also includes a light emitter (22) and a light receiver (23); The bracket (61) further includes a second light guide (614), which is disposed on the surface of the base plate (611) facing the bottom shell (10). The light emitter (22) and the light receiver (23) are both disposed opposite to the second light guide (614) and are spaced apart from each other.

9. The fire alarm device according to claim 8, characterized in that, It also includes a smoke guide plate (30), which is installed between the bottom shell (10) and the front shell (40) and has a light guide channel (31) and a light outlet channel (32). The light emitter (22) is disposed in the light guide channel (31) and the light receiver (23) is disposed in the light outlet channel (32).

10. The fire alarm device according to claim 9, characterized in that, The second light guide (614) includes a light guide pin (6141) and a light guide pin (6142), wherein the light guide pin (6141) extends into the light guide channel (31) and the light guide pin (6142) extends into the light guide channel (32).

11. The fire alarm device according to claim 8, characterized in that, It also includes a partition (36) disposed inside the bottom shell (10) and located between the light emitter (22) and the light receiver (23), the partition (36) being configured to block the light beam emitted directly from the light emitter (22) to the light receiver (23).

12. The fire alarm device according to claim 2, characterized in that, The bracket (61) is provided with an elastic arm (6112) configured to drive the button (50) to reset.

13. The fire alarm device according to claim 4, characterized in that, In the radial projection of the first light guide (612), the two ends of the first light guide (612) gradually move away from each other in the direction from the sound hole (615) to the shell (40) to form a horn-shaped structure.

14. The fire alarm device according to claim 3, characterized in that, The bracket (61) includes a base plate (611) and a third light guide (616). The third light guide (616) is disposed on the surface of the base plate (611) facing the bottom shell (10), and the third light guide (616) is disposed opposite to the indicator light (80).

15. The fire alarm device according to any one of claims 1-14, characterized in that, Along the axial direction of the sound-emitting hole (615), the sound-emitting hole (615) is disposed opposite to the sound-emitting gap (70).

16. A fire alarm device, characterized in that, include: Bottom shell (10); A face shell (40) is installed on the bottom shell (10), and the face shell (40) is provided with a through hole (41); A button (50) is pressably disposed within the through hole (41); An indicator light (80) is disposed inside the bottom shell (10); A sound generator (60) includes a bracket (61) and a buzzer (62). The bracket (61) is mounted on the side of the front shell (40) facing the bottom shell (10), and the buzzer (62) is mounted on the bracket (61). The bracket (61) is a transparent part. The bracket (61) has a light guide that extends between the hole wall of the through hole (41) and the outer peripheral surface of the button (50); the light guide is disposed opposite to the indicator light (80).

17. A fire alarm device, characterized in that, include: Bottom shell (10); The light emitter (22) and the light receiver (23) are both disposed inside the bottom shell (10); A face shell (40) is installed on the bottom shell (10), and the face shell (40) is provided with a through hole (41); A button (50) is pressably disposed within the through hole (41); The bracket (61) is a transparent component. The bracket (61) includes a base plate (611), a first light guide (612), and a second light guide (614). The base plate (611) is installed on the side of the face shell (40) facing the base shell (10). The first light guide (612) is disposed on the surface of the base plate (611) facing away from the bottom shell (10) and extends to the space between the hole wall of the through hole (41) and the outer peripheral surface of the button (50); The second light guide (614) is disposed on the surface facing the bottom shell (10), and the light emitter (22) and the light receiver (23) are disposed opposite to the second light guide (614), and the light emitter (22) and the light receiver (23) are spaced apart from each other.

18. A method for self-inspection of spray coating contamination, characterized in that, For use in a fire alarm, the fire alarm comprising: Bottom shell (10); The light emitter (22) and the light receiver (23) are both disposed inside the bottom shell (10), and the light emitter (22) and the light receiver (23) are separated from each other; A face shell (40) is installed on the bottom shell (10), and the face shell (40) is provided with a through hole (41); A light guide portion, one end of which extends to the through hole (41), and the other end of which is disposed opposite to both the light emitter (22) and the light receiver (23); The self-inspection method for spray coating contamination includes: Control the light emitter to emit light; The fire alarm is determined to be contaminated by spray paint based on changes in the electrical signal received from the optical receiver.

19. A fire alarm system, characterized in that, include: Fire alarm according to any one of claims 1-17; The fire alarm includes multiple devices, and the multiple fire alarms are interconnected and communicate with each other.

Images