Photoelectric smoke fire alarm detection component and photoelectric smoke fire alarm

Abstract

The present invention belongs to the technical field of fire detection and alarm, and specifically relates to a detection component that can be applied to a photoelectric smoke fire alarm, and a fire alarm having the detection component. The detection component includes a base plate, on which a first transmitting tube, a second transmitting tube and a receiving tube are provided. The first and second transmitting tubes are both scatteredly matched with the receiving tube, and the central axis of the first transmitting tube does not overlap with the central axis of the second transmitting tube; the detection component also includes a scattering mechanism, so that the optical signals of the first transmitting tube and the second transmitting tube cannot be directly received by the receiving tube. The detection component of the present invention improves its detection accuracy and precision through structural innovation, and cooperates with the circuit detection system to realize the modulation of the emitted optical signal to adapt to the detection of different smoke, thereby greatly improving the detection accuracy. The fire alarm of the present invention includes the above-mentioned detection component, and in combination with the maze structure, it can further reduce the interference of external light on the detector.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire detection and alarm, and in particular relates to a detection component applicable to a photoelectric smoke fire alarm, and an alarm having the detection component. Background Art

[0002] A fire is a catastrophic, uncontrolled combustion phenomenon that occurs in time or space. It is one of the most frequent and widespread threats to public safety and social development. Once a fire or explosion occurs, it can result in significant casualties and economic losses. The fire process can generally be divided into five stages: initiation, development, intensity, decline, and extinction. In the initial stage, the burning area is generally small, the flames are not high, the radiant heat is not strong, the smoke and gas flow is slow, and the combustion rate is not fast, making it the optimal time for firefighting. At this stage, with timely detection, minimal manpower and firefighting equipment are required to extinguish the fire. Therefore, from a firefighting perspective, earlier detection and early warning facilitate fire extinguishing, making the initial and development stages critical for firefighting. Therefore, fire alarms (also known as smoke alarms) are of practical significance for preventing fires and reducing fire losses.

[0003] Fire alarms include smoke detectors (including ionization and photoelectric smoke detectors), temperature detectors (including fixed-temperature and differential-temperature detectors), gas detectors, and infrared detectors. Smoke detectors are the most commonly used type of fire alarm because they sense smoke and generate early warning signals, extinguishing fires before they become a disaster.

[0004] Photoelectric smoke alarms primarily consist of a light source, a photoelectric element, and an electronic switch. They utilize the principle of light scattering to detect smoke generated in the early stages of a fire and promptly issue a fire alarm signal. Photoelectric smoke alarms are generally categorized as either light-blocking or light-scattering types, depending on their structural characteristics. In light-scattering photoelectric smoke alarms, the light-emitting diode and photoelectric element (i.e., receiving tube) are positioned misaligned. In the absence of smoke, light cannot reach the photoelectric element, maintaining normal circuitry. When a fire occurs, smoke enters the detector, and light is reflected or scattered by smoke particles and received by the photoelectric element. The light signal is converted into an electrical signal, amplified by an amplifier circuit, and then the alarm signal is issued.

[0005] Therefore, it is necessary to innovate the structure of the existing photoelectric smoke fire alarm to improve its detection accuracy. Summary of the Invention

[0006] The object of the present invention is to provide a photoelectric smoke fire alarm detection component which has high fire detection accuracy and is easy to manufacture and assemble, and a photoelectric smoke fire alarm having the detection component.

[0007] As a first aspect of the present invention, a novel photoelectric smoke fire alarm detection assembly is provided, which is a detection assembly for a photoelectric smoke fire detection alarm and includes a base plate; a first transmitting tube, a second transmitting tube and a receiving tube are provided on the base plate, and the first transmitting tube and the second transmitting tube are both scatteredly matched with the receiving tube; and the central axes of the first transmitting tube and the second transmitting tube do not overlap, that is, the first transmitting tube, the second transmitting tube and the receiving tube are arranged in a triangular shape.

[0008] The detection assembly further includes a scattering mechanism to prevent the optical signals emitted by the first emitting tube and the second emitting tube from being directly received by the receiving tube.

[0009] Preferably, the scattering mechanism includes an angle control mechanism, which is a light-shielding tube and / or a refractor, which is arranged at the front end of the first transmitting tube and / or the second transmitting tube to control the transmission angle range of the optical signals of the two so that the transmission angle range is not too large and the optical signal of the transmitting tube is directly received by the receiving tube.

[0010] Preferably, the scattering mechanism includes a shield, which is arranged on the base plate and located between the first transmitting tube and / or the second transmitting tube and the receiving tube to control the transmission angle range of the optical signals of both, so that the transmission angle range is not too large so that the optical signal of the transmitting tube is directly received by the receiving tube.

[0011] Preferably, the first transmitting tube, the second transmitting tube, and the receiving tube are disposed on the base plate with their respective central axes horizontally arranged (i.e., disposed on the base plate with each central axis arranged horizontally). The horizontal arrangement is relative to a base plate reference plane, which can be the base plate's central plane, upper surface, lower surface, or other unique and defined reference plane. The three central axes can lie together on a reference plane parallel to the reference plane (i.e., coplanar arrangement), or separately on three reference planes parallel to the reference plane. In short, the transmitting tubes are generally relatively horizontal, without any pitch angle.

[0012] Preferably, the first transmitting tube, the second transmitting tube, and the receiving tube are arranged on the base plate with their respective central axes tilted (i.e., they are arranged on the base plate in a manner such that their central axes are tilted). This is another state corresponding to the above-mentioned horizontal arrangement, that is, the pitch of the transmitting / receiving tubes is adjusted accordingly so that they are tilted upward at a certain angle relative to the reference surface.

[0013] Obviously, by using at least one of the above technical means, the application of the detection component can be realized while the size of the fire alarm remains unchanged or substantially unchanged.

[0014] Furthermore, the first transmitting tube and the receiving tube have the same inclination angle relative to the base plate, while the second transmitting tube has a different inclination angle relative to the base plate, which can be greater or less than the first, to ensure that the actual angles of the two transmitting tubes and the receiving tube are different. Strictly speaking, it is sufficient to ensure that the inclination angles of the two transmitting tubes are different. There is no specific requirement for the inclination angles of the first transmitting tube and the receiving tube. However, changes in the inclination angles of the two will affect the overall size of the maze. Setting them greater or less than the first transmitting tube will make the overall size larger. For the sake of the overall size of the alarm, the inclination angles of the two are set to be the same.

[0015] Preferably, a shield is further provided on the bottom plate, and there are two shields; one of the shields is provided on a side of the front of the first transmitting tube, so that the optical axis of the side of the first transmitting tube is blocked by it and cannot be directly received by the receiving tube, and the other shield is provided on a side of the head of the second transmitting tube, so that the optical axis of the side of the second transmitting tube is blocked by it and cannot be directly received by the receiving tube.

[0016] Preferably, a shield is further provided on the bottom plate; the shield includes a first shielding portion and a second shielding portion, the first shielding portion shields part of the emission angle of the first transmitting tube so that its optical signal is not directly received by the receiving tube, and the first shielding portion and the second shielding portion jointly shield part of the emission angle of the second transmitting tube so that its optical signal is not directly received by the receiving tube.

[0017] Preferably, a shield is further provided on the bottom plate; the shield is in the shape of an elongated strip and is arranged in the common area between the first transmitting tube, the second transmitting tube and the receiving tube; and the shield is arranged obliquely in the horizontal direction, so that the optical signals emitted by the first transmitting tube and the second transmitting tube cannot be directly received by the receiving tube, but are scattered in the three-dimensional direction after passing over the top of the shield.

[0018] Preferably, the angle θ1 between the central axis of the first transmitting tube and the central axis of the receiving tube is 10-55°; and / or the angle θ2 between the central axis of the second transmitting tube and the central axis of the receiving tube is 70-140°.

[0019] As a second aspect of the present invention, a new type of photoelectric smoke fire alarm is provided, which is a photoelectric smoke fire detection alarm for fire alarm, which includes a detector and an optical maze. The optical maze includes a base, and a maze portion is provided on one side of the base. The detector is matched with the side to form a fire alarm.

[0020] The detector includes a detection component, which is a photoelectric smoke fire alarm detection component as described in any one of the above items.

[0021] The labyrinth portion has a labyrinth passage, which is formed by the cooperation of a first block portion and a second block portion. The first block portion includes a first ridge and a second ridge, and the second block portion includes a third ridge and a fourth ridge. The angle between the third ridge and the fourth ridge is an acute angle, and the fourth ridge extends into the area between the first ridge and the second ridge.

[0022] For photoelectric smoke alarms, external light entering the detector assembly inevitably interferes with detection accuracy. Therefore, photoelectric smoke alarms typically incorporate an optical maze to reduce this interference. This maze, with its unique channel shape, significantly reduces the interference of external light on the detector.

[0023] Preferably, the fourth conduit extends to the junction of the first conduit and the second conduit, forming a "Z"-shaped (including similar to "Z"-shaped) labyrinthine passage. More preferably, the end of the fourth conduit is arranged parallel to the second conduit to form a parallel portion.

[0024] Preferably, the detector also includes an upper cover, the interior of the upper cover is hollow to form a detection cavity, and at least a portion of the detection component is accommodated in the detection cavity; the upper cover has a first opening and a second opening, the second opening cooperates with the bottom plate, and the first opening cooperates with the optical maze to allow external smoke to pass through the optical maze and enter the detection cavity to be detected by the detection component.

[0025] Preferably, the cross-sectional shapes of the first, second, third and fourth humidities are straight, arc or wavy.

[0026] Preferably, the cross-section of the labyrinth portion is annular, polygonal or elliptical.

[0027] Furthermore, the optical maze also includes a chamber, which is connected to the detection component and is arranged at the center of the maze.

[0028] More preferably, a flow guide is provided in the chamber, and the flow guide includes a plurality of guide blades.

[0029] Preferably, the maze passage is formed by two adjacent maze blocks arranged at intervals, and the maze blocks include a head, a middle and a tail; the head and the tail are respectively arranged at the two ends of the middle, and the two are oriented in different directions; the angle between the middle and the tail is an acute angle, and each maze block is arranged on the base in the same direction.

[0030] Moreover, the tail end of the previous maze block extends into the area between the head end and the middle end of the next maze block; the middle end and the tail end of the previous maze block respectively form the third end and the fourth end of the second block, while the head end and the middle end of the next maze block respectively form the first block including the first end and the second end.

[0031] Furthermore, the cross-sectional shape of the labyrinth portion is annular, and the cross-sectional shape of the head is arc-shaped.

[0032] The photoelectric smoke fire alarm detection assembly of the present invention improves detection accuracy and precision through innovative structural design, effectively avoiding the adverse effects of interference sources and enabling precise detection of various fire types. Furthermore, in conjunction with the circuit detection system of the present invention, the optical signals emitted by the two transmitting tubes can be modulated, allowing the CPU to dynamically modulate the detection assembly to accommodate different smoke levels. For example, the current waveform of the detection optical signal can be dynamically adjusted based on smoke concentration or particle size, and the appropriate optical signal can be selected for detection, significantly improving detection accuracy.

[0033] The photoelectric smoke fire alarm of the present invention includes the above-mentioned detection component, so the detection accuracy and precision meet the requirements; and, in combination with the maze structure, the interference of external light on the detector can be further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a schematic diagram of the launch parameters of an existing launch tube; wherein, Figure 1a and Figure 1b Schematic diagrams of emission angles from two perspectives: front view and top view; Figure 1c This is a graph showing the relationship between relative gradient intensity and angular displacement for a transmitting tube with an 18° viewing angle. The arcs radiating outward from the transmitting point O represent nine relative gradient intensity reference lines ranging from 0.1 to 1.0. The straight lines radiating outward from the transmitting point O represent angular displacement value reference lines ranging from 0 to 90°. The closed solid line area between -10° and 10° represents the actual viewing angle range of the transmitting tube.

[0035] FIG2 is a schematic diagram of two emission angle range control structures of the present invention; wherein, Figure 2a This is a schematic diagram of the emission angle range control when using a light-shielding tube. Angle A is the original emission angle range of the emission tube, and angle A' is the emission angle range after control. Figure 2b This is a schematic diagram of the emission angle range control when a refractive lens is used. Angle A is the original emission angle range of the emission tube, and angle A' is the emission angle range after control.

[0036] Figure 3 1 is a schematic diagram of the three-dimensional structure of the detection assembly according to the first embodiment of the present invention;

[0037] Figure 4 yes Figure 3 A top view of an embodiment; wherein the center line is the central axis of the transmitting tube / receiving tube, and θ1 and θ2 are the angular relationships between the first transmitting tube and the second transmitting tube and the receiving tube respectively;

[0038] Figure 5 yes Figure 3 Schematic diagram of the actual transmission / reception angle range after the transmission / reception angle range is controlled by the shield in the embodiment;

[0039] Figure 6 is a schematic diagram of the three-dimensional structure of the detection assembly of the second embodiment of the present invention;

[0040] Figure 7 yes Figure 6 A side view of an embodiment;

[0041] Figure 8 yes Figure 6 Schematic diagram of the actual transmission / reception angle range after the transmission / reception angle range is controlled by the shield in the embodiment;

[0042] Figure 9 is a schematic diagram of the three-dimensional structure of the detection assembly of the third embodiment of the present invention;

[0043] Figure 10 yes Figure 9 A top view of an embodiment; wherein the center line is the central axis of the transmitting tube / receiving tube;

[0044] Figure 11 yes Figure 9 Schematic diagram of the actual transmission / reception angle range after the transmission / reception angle range is controlled by the shield in the embodiment;

[0045] Figure 12 1 is a schematic diagram of the overall system module structure of the embodiment;

[0046] Figure 13 is a schematic diagram of a central processing unit of an embodiment;

[0047] FIG14 is a diagram of two first optical signal modulation modules according to an embodiment; Figure 14a This is a schematic diagram of the structure of a first optical signal modulation module having three current control branches I1, I2, and I3; Figure 14b Schematic diagram of the structure of the first optical signal modulation module in which the current control branch is expanded to I1…In;

[0048] FIG15 is a diagram of two second optical signal modulation modules in an embodiment; Figure 15a This is a schematic diagram of the structure of a second optical signal modulation module having three current control branches I1, I2, and I3; Figure 15bSchematic diagram of the second optical signal modulation module structure in which the current control branch is expanded to I1…In;

[0049] FIG16 is a diagram of two third optical signal modulation modules in the embodiment; Figure 16a This is a schematic diagram of the structure of a third optical signal modulation module having three current control branches I1, I2, and I3; Figure 16b Schematic diagram of the structure of the third optical signal modulation module with the current control branch expanded to I1…In;

[0050] FIG17 is a diagram of two fourth optical signal modulation modules according to an embodiment; Figure 17a Schematic diagram of the structure of a fourth optical signal modulation module having three current control branches I1, I2, and I3; Figure 17b Schematic diagram of the structure of the fourth optical signal modulation module with the current control branch expanded to I1…In;

[0051] Figure 18a Schematic diagram of the circuit structure of the embodiment (I) in which the voltage divider module, the photoelectric conversion module, the signal distortion prevention module and the signal amplification module are combined;

[0052] Figure 18b Schematic diagram of the circuit structure of the embodiment (II) in which the voltage divider module, the photoelectric conversion module, the signal distortion prevention module and the signal amplification module are combined;

[0053] FIG19 is a schematic structural diagram of a photoelectric smoke fire alarm according to another embodiment of the present invention; wherein, Figure 19a This is a schematic diagram of its overall structure. Figure 19b It is a schematic diagram of the decomposition structure of the main components;

[0054] FIG20 is a schematic structural diagram of the upper cover in the embodiment of FIG19; wherein, Figure 20a is a schematic diagram of its three-dimensional structure. Figure 20b is its cross-sectional view;

[0055] Figure 21 Figure 1 is a schematic top view of the optical maze structure of an embodiment of the present invention. To ensure the closed effect of the labyrinth, a connecting portion is provided between the first and second blocking portions forming each labyrinth channel, so that the entire labyrinth is sealed except for the labyrinth channels. The black arrows represent a schematic diagram of the entry of external gas into the chamber.

[0056] Figure 22 20 is an enlarged schematic diagram of the structure of the maze channel; the black arrows indicate the flow direction of the external gas entering;

[0057] Figure 23 FIG19 is a schematic diagram of the three-dimensional structure of the optical maze in the embodiment;

[0058] Figure 24yes Figure 23 Schematic diagram of the back structure;

[0059] Figure 25 yes Figure 23 Schematic diagram of the structure from the front, where the black arrows indicate the schematic diagram of external gas entering the chamber;

[0060] Figure 26 yes Figure 23 sectional view of

[0061] Figure 27 19 is a cross-sectional schematic diagram of the optical maze and the detection assembly of the embodiment; wherein the upper half is the optical maze 1, and the lower half is the upper cover 2 and the detection assembly 3;

[0062] Figure 28 is a schematic diagram of a pulse current in an embodiment of the present invention;

[0063] FIG29 is a schematic diagram of pulse current in another embodiment of the present invention, Figure 29a 、 29b 29c are schematic diagrams of three types of pulse currents. DETAILED DESCRIPTION

[0064] In order to enable those skilled in the art to better understand the present invention, and thus to more clearly define the scope of protection claimed in the present invention, the present invention is described in detail with respect to certain specific embodiments of the present invention. It should be noted that the following are only certain specific embodiments of the present invention, which are only part of the embodiments of the present invention, wherein the specific and direct description of the relevant structures is only for the convenience of understanding the present invention, and the various specific features do not naturally and directly limit the scope of implementation of the present invention. The conventional selection and replacement made by those skilled in the art under the guidance of the present invention, as well as the reasonable arrangement and reorganization of the relevant technical features of the present invention, should all be deemed to be within the scope of protection claimed in the present invention.

[0065] A novel detection assembly of a photoelectric smoke fire detection alarm includes a base plate 400, on which are provided a first transmitting tube 401, a second transmitting tube 402 and a receiving tube 403. The first transmitting tube 401 and the second transmitting tube 402 are arranged on the base plate 400 in a scattered manner to cooperate with the receiving tube 403; that is, the light signals emitted by the first transmitting tube 401 and the second transmitting tube 402 cannot be directly received by the receiving tube 403, but need to be scattered or reflected by other media (such as the smoke to be detected).

[0066] The emission angle range of existing general-purpose transmitting tubes can reach 10-170°, but the viewing angle generally varies from 16°, 18°, 20°, 30°, and 40° (the viewing angle refers to the angle range of 60% of the central light intensity); the receiving angle range of receiving tubes is generally 0-180°. The size range of existing fire alarms is generally 100-120mm in diameter and 25-60cm in height. Figure 1a 、 1b As shown, for a given transmitting tube, the emission angle on any cross section passing through the central axis is the same, thus forming a cone-shaped optical signal emission range (i.e., viewing angle). Therefore, when a common transmitting tube is used as the first transmitting tube 401 and the second transmitting tube 402 of the detection assembly of the present invention in an existing fire alarm, it is difficult to achieve scattering coordination between the transmitting tube and the receiving tube, regardless of how the relative position or pitch angle of the transmitting tube and the receiving tube 403 changes.

[0067] If the fire alarm's dimensions are outside the existing size range (i.e., regardless of the alarm size limit), using existing transmitting and receiving tubes and arranging them on the base plate 400 in the aforementioned scattering coordination manner would likely result in the alarm exceeding the required thickness and a reduction in detection accuracy and precision. This would obviously cause the finished fire alarm's external dimensions to significantly exceed the existing size range, causing inconvenience in its installation and use.

[0068] Therefore, while the external dimensions of the fire alarm remain basically unchanged, the present invention starts from the aspects of controlling the emission angle range of the transmitting tube, controlling the receiving angle range of the receiving tube, setting the relative position of the transmitting tube and the receiving tube, and partial blocking by obstacles, and sets the component parameters, structure (including relative position) and other aspects of the detection assembly to meet the above requirements.

[0069] 1. Emission angle range control: customize a transmitting tube with a smaller emission angle range, or reduce the actual emission angle range of the transmitting tube through components such as a light-shielding tube and a refracting lens, so that the two transmitting tubes and the receiving tube can achieve scattering coordination even within the size limit of the existing fire alarm or within the allowable size variation range.

[0070] For example, Figure 2a As shown, a hollow and opaque light-shielding tube is placed on the transmitting tube, so that the transmitting angle range of the transmitting tube is reduced from the original angle A to angle A'. As can be seen from the figure, its angle range is significantly reduced and is controlled by the shape of the light-shielding tube. Figure 2bAs shown, a lens is set at the front end of the transmitting tube, which can reduce the emission angle range of the transmitting tube from the original angle A to angle A'. As can be seen from the figure, its angle range is significantly reduced and is controlled by the parameters of the lens and its setting position.

[0071] The light shielding tube and the refractor are two relatively simple and practical solutions for controlling the transmission (reception) angle. They can be used alone or in combination to adjust the transmission angle of the existing transmitting tube to meet the requirements of the detection assembly. Furthermore, the specific parameters of the light shielding tube and the lens can be set as needed and are not limited here.

[0072] Second, shielding: A shield 404 is additionally provided on the base plate 400. The shield 404 is disposed between the first transmitting tube 401 and / or the second transmitting tube 402 and the receiving tube 403 to prevent the optical signal emitted by the first transmitting tube 401 or the second transmitting tube 402, which has a larger emission angle range, from being directly received by the receiving tube 403. The specific shape and position of the shield 404 are not limited in principle, and any shape that can block direct communication between the transmitting tube and the receiving tube (i.e., prevent the optical signal from the transmitting tube from propagating in a straight line and then being received by the receiving tube) is acceptable.

[0073] For example, Figure 3-8 As shown, the number of shields 404 can be one, two or more, and their settings can be located between the first transmitting tube 401 and the second transmitting tube 402 and the receiving tube 403, or in the common area between the three, so as to achieve control of the emission angle of the two transmitting tubes so that the optical signal is not directly received by the receiving tube 403.

[0074] The above are two main ways to implement scattering coordination. For these two types of implementation, in order to make the central optical axes of the two transmitting tubes not overlap, the parts can be further arranged in two directions: plane dislocation and three-dimensional dislocation.

[0075] First, plane misalignment.

[0076] The structural layout is as follows Figure 3 、 4 As shown, the first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403 are arranged on the base plate 400 with their respective central axes coplanar or parallel. For example, their respective central axes are parallel to the surface or center plane of the base plate 400. In short, the central axes of the three tubes can be coplanar or parallel. Furthermore, the first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403 are arranged on the base plate 400 in a triangular shape to prevent the first transmitting tube 401 and the second transmitting tube 402 from aligning their emission angles.

[0077] At the same time, Figure 3 、4 In the embodiment, existing transmitting tubes are directly used without controlling their emission angles. Instead, two shields 404 are respectively provided between the first transmitting tube 401 and the second transmitting tube 402 and the receiving tube 403, so that the two transmitting tubes cooperate with the receiving tube in a scattered manner. Of course, if shields 404 are not provided, but the emission angles of the two transmitting tubes are controlled (the specific method is the same as above) and matched with a specific relative position relationship of the transmitting tubes and the receiving tubes, this is also feasible.

[0078] Second, three-dimensional dislocation.

[0079] The structural layout is as follows Figure 7 、 8 As shown, the first, second, and receiving tubes 401, 402, and 403 are arranged on the base plate 400 with their respective central axes tilted upward. The tilt angles of the three tubes are not limited in principle, but in practical applications, the tilt angles of the first and second tubes 401, 403 can be the same, while the tilt angle of the second tube 402 can be smaller (i.e., the tilt angle of either the first or second tubes 401, 403) to ensure controllable overall height. The first, second, and receiving tubes 401, 402, and 403 are arranged on the base plate 400 in a triangular shape to prevent the first and second tubes 401, 402 from having the same launch angle.

[0080] At the same time, Figure 5 、 6 In the embodiment, the existing transmitting tube is directly used without controlling its transmitting angle. Instead, a long strip-shaped shield 404 is set in the area between the first transmitting tube 401, the second transmitting tube 402 and the receiving tube 403, so that the two transmitting tubes and the receiving tube can cooperate with each other in a scattered manner. Of course, if the shield 404 is not set, but the transmitting angle of the two transmitting tubes is controlled (the specific method is the same as above), and the relative position relationship between the transmitting tube and the receiving tube is matched, it is also feasible. It is particularly important to note that for this structural layout, the light-shielding tube is a better angle control method (of course, this can also be understood as a variation of the shield 404).

[0081] In addition, for the above two structural layouts, although the scattering coordination is mainly achieved in the form of the existing transmitting tube + shield 404, this does not mean that the emission angle control cannot be combined and applied.

[0082] Example 1

[0083] like Figure 3 、 4As shown, a novel photoelectric smoke fire alarm detection assembly includes a base plate 400 in the shape of a flat cylinder. A first transmitting tube 401, a second transmitting tube 402, and a receiving tube 403 are disposed on the surface of the base plate 400. The first transmitting tube 401 and the second transmitting tube 402 are arranged on the base plate 400 in a scattered manner to cooperate with the receiving tube 403. In other words, the optical signals emitted by the first transmitting tube 401 and the second transmitting tube 402 cannot be directly received by the receiving tube 403, but must be scattered or reflected by other media (such as the smoke to be detected) before they can be received by the receiving tube 403.

[0084] To achieve scattering coordination between the two transmitting tubes and the receiving tube, two shields 404 are provided on the base plate 400. One shield 404 is provided on a side surface in front of the first transmitting tube 401 to block the optical axis of the first transmitting tube 401 from being directly received by the receiving tube 403. The other shield 404 is provided on a side surface at the head of the second transmitting tube 402 to block the optical axis of the second transmitting tube 402 from being directly received by the receiving tube 403. In other words, the two shields 404 are provided to prevent the optical signals detected by the first transmitting tube 401 and the second transmitting tube 402 from being directly received by the receiving tube 403. Any structural variations that meet this requirement are feasible and are not limited here.

[0085] The central optical axes of the first transmitting tube 401, the second transmitting tube 402 and the receiving tube 403 are located on the same plane and are parallel to the surface of the base plate 400; the shield 404 has a certain height so that its upper edge is higher than the effective transmitting height of the first transmitting tube 401 and the second transmitting tube 402, that is, the scattering coordination between the first transmitting tube 401 and the second transmitting tube 402 and the receiving tube 403 is completed within the plane (of course, also within a certain range above and below the plane), rather than a three-dimensional scattering coordination beyond the top of the shield 404.

[0086] The transmission and reception angle ranges of this embodiment are as follows: Figure 5 As shown, three angles are marked, A1, A2, and B are the actual transmission / reception angle ranges of the first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403. Obviously, the transmitting tube and the receiving tube do not directly cooperate.

[0087] Example 2

[0088] like Figure 6 、 7As shown, a novel photoelectric smoke fire alarm detection assembly includes a base plate 400 in the shape of a flat cylinder. A first transmitting tube 401, a second transmitting tube 402, and a receiving tube 403 are disposed on the surface of the base plate 400. The first transmitting tube 401 and the second transmitting tube 402 are arranged on the base plate 400 in a scattered manner to cooperate with the receiving tube 403. That is, the optical signals emitted by the first transmitting tube 401 and the second transmitting tube 402 cannot be directly received by the receiving tube 403, but must be scattered or reflected by other media (such as the smoke to be detected) before they can be received by the receiving tube 403. The first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403 are arranged on the base plate 400 in a triangular shape. The angle between the first transmitting tube 401 and the receiving tube 403 is 90 degrees, and the angle between the second transmitting tube 402 and the receiving tube 403 is 180 degrees.

[0089] To achieve scattering coordination between the two transmitting tubes and the receiving tube, a shield 404 is provided on the base plate 400. The shield 404 is long and strip-shaped and is located in the common area between the first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403. Furthermore, the first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403 are all arranged on the base plate 400 at an angle relative to the surface of the base plate 400. The angle between the central axis of the first transmitting tube 401 and the plane of the base plate 400 and the angle between the central axis of the receiving tube 403 and the plane of the base plate 400 can be the same, while the angle between the central axis of the second transmitting tube 402 and the plane of the base plate 400 can be smaller than the angle between the central axis of the receiving tube 403 and the plane of the base plate 400 (i.e., the angle between the central axis of the receiving tube 403 and the plane of the base plate 400). It should be noted that the surface of the base plate 400 is used as a reference surface to determine the tilt relationship between the first transmitting tube 401, the second transmitting tube 402 and the receiving tube 403. It can also be the bottom surface or center surface of the base plate 400, or other uniquely determined virtual reference surface.

[0090] To block the direct path between the transmitting and receiving tubes, shield 404 should be of an appropriate height. Furthermore, to provide shielding between the two transmitting tubes, shield 404 should be tilted horizontally. This prevents the optical signals emitted by first transmitting tube 401 and second transmitting tube 402 from being directly received by receiving tube 403. Instead, they pass over the top of shield 404 and are scattered in three dimensions.

[0091] It should be noted that in this embodiment, since the angle between the first transmitting tube 401 and the receiving tube 403 is 90°, in principle, the shield 404 has no effect on this. However, when the angle or distance between the two changes, allowing the optical signal emitted by the first transmitting tube 401 to be directly received by the receiving tube 403, the shield 404 needs to block this direct reception. The height and length of the shield 404 can be set as needed, and any method that can achieve direct blocking is not limited to the specific situation.

[0092] The transmission and reception angle ranges of this embodiment are as follows: Figure 8 As shown, the two marked angles are the actual transmission / reception angle ranges of the second transmitting tube 402 and the receiving tube 403. Obviously, in this case, the transmitting tube and the receiving tube do not directly cooperate.

[0093] Example 3

[0094] like Figure 9 、 10 As shown, a novel photoelectric smoke fire alarm detection assembly includes a base plate 400 in the shape of a flat cylinder. A first transmitting tube 401, a second transmitting tube 402, and a receiving tube 403 are disposed on the surface of the base plate 400. The first transmitting tube 401 and the second transmitting tube 402 are arranged on the base plate 400 in a scattered manner to cooperate with the receiving tube 403. In other words, the optical signals emitted by the first transmitting tube 401 and the second transmitting tube 402 cannot be directly received by the receiving tube 403, but must be scattered or reflected by other media (such as the smoke to be detected) before they can be received by the receiving tube 403.

[0095] To achieve scattering coordination between the two transmitting tubes and the receiving tube, a shield 404 is provided on the base plate 400. The shield 404 includes a first shielding portion 4041 and a second shielding portion 4041. The first shielding portion 4041 blocks part of the emission angle of the first transmitting tube 401 so that its optical signal is not directly received by the receiving tube 403. The first shielding portion 4041 and the second shielding portion 4041 jointly block part of the emission angle of the second transmitting tube 402 so that its optical signal is not directly received by the receiving tube 403. As a result, both the first transmitting tube 401 and the second transmitting tube 402 are scatteringly coordinated with the receiving tube 403.

[0096] The central optical axes of the first transmitting tube 401, the second transmitting tube 402 and the receiving tube 403 are located on the same plane and are parallel to the surface of the base plate 400; the shield 404 has a certain height so that its upper edge is higher than the effective transmitting height of the first transmitting tube 401 and the second transmitting tube 402, that is, the scattering coordination between the first transmitting tube 401 and the second transmitting tube 402 and the receiving tube 403 is completed within the plane (of course, also within a certain range above and below the plane), rather than a three-dimensional scattering coordination beyond the top of the shield 404.

[0097] The transmission and reception angle ranges of this embodiment are as follows: Figure 11 As shown, three angles are marked, A1, A2, and B are the actual transmission / reception angle ranges of the first transmitting tube 401, the second transmitting tube 402, and the receiving tube 403. Obviously, the transmitting tube and the receiving tube do not directly cooperate.

[0098] In addition, although in the above three embodiments, the conventional large-angle transmitting tube and the shield are used to achieve the scattering coordination between the transmitting tube and the receiving tube; however, the above-mentioned transmitting angle control can obviously be combined with any one of them.

[0099] Furthermore, the plane scattering angle and plane included angle described in the above embodiments do not mean that the relevant central optical axes need to be on the same plane, but refer to their angular relationship on a virtual plane referenced for measuring the included angle between the two optical axes.

[0100] To better implement fire alarms, the detection component, based on the above-mentioned physical structure, also includes a detection circuit system. The detection circuit system is used to modulate the optical signals emitted by the two emitting tubes (i.e., the first emitting tube 401 and the second emitting tube 402) so that the current waveforms of the two emitting tubes can each have at least one current pulse within the same modulation period. The current pulses emitted by the first emitting tube 401 and the second emitting tube 402 can be independent of each other or overlap with each other (independence means that the timing of the two is completely different and there is no overlap, while overlap includes being completely the same and at least partially overlapping. When there is partial overlap, the timing width of the overlap should meet the performance requirements of the receiving tube). When the current pulses of the two are independent of each other, the receiving tube 403 can respectively receive the scattered light signals of the two, thereby obtaining two light intensity data. When the two overlap, the receiving tube 403 can only receive one scattered light signal and obtain one light intensity data.

[0101] The plane scattering angle formed by the central optical axis of the first transmitting tube 401 and the central optical axis of the receiving tube 403 is called the scattering angle θ1, and the plane scattering angle formed by the central optical axis of the second transmitting tube 402 and the central optical axis of the receiving tube 403 is called the scattering angle θ2. The angle ranges of θ1 and θ2 can be 10°-55° and 70°-140°, respectively; therefore, the light intensity data obtained by the receiving tube 403 can be respectively counted as the scattered light intensity data at the scattering angle θ1, the scattered light intensity data at the scattering angle θ2, and the scattered light intensity data at the scattering angle θ12, which respectively represent the scattered light intensity data when the first transmitting tube 401 acts alone, the second transmitting tube 402 acts alone, and the first transmitting tube 401 and the second transmitting tube 402 act together.

[0102] In a preferred embodiment, the first emitting tube 401 and the second emitting tube 402 should each have at least two current pulses within the same modulation cycle, namely, a first current pulse and a second current pulse. The first current pulses of the two emitting tubes are independent of each other (i.e., their timings are different, or they partially overlap and the overlap is less than the detection requirements of the receiving tube 403, thereby effectively achieving the effect of the two current pulses being independent of each other), while the second current pulses at least overlap (i.e., their timings at least partially overlap and the overlap width meets the detection requirements of the receiving tube 403). Therefore, the scattered light intensities at scattering angles θ1 and θ2 are the scattered light intensities generated by the first current pulses of the first emitting tube 401 and the second emitting tube 402 acting alone, respectively, while the scattered light intensity at scattering angle θ12 is the scattered light intensity generated by the second current pulses of the first emitting tube 401 and the second emitting tube 402 acting together. That is, within a modulation cycle, the two emitting tubes 401 and 402 independently transmit according to a predetermined modulation method, and the receiving tube 403 can receive three scattered light intensity data within the modulation cycle.

[0103] like Figure 12 As shown in Figure 18, in certain preferred embodiments, the detection circuit system includes a signal modulation module 7, a photoelectric conversion module 4, and a signal amplification module 5. The input end of the photoelectric conversion module 4 is mounted with a light receiving module 3, and the signal modulation module 7 is mounted with a light emitting module 2. The output end of the photoelectric conversion module 4 is connected to the input end of the signal amplification module 5, and the output end of the signal amplification module is connected to the input end of the signal modulation module. The signal modulation module converts the received digital signal into an analog signal and then outputs it to modulate the light emission mode of the light emitting module. There are at least two light emitting modules 2, and other components are configured accordingly.

[0104] The analog signal emitted by the signal modulation module is received by the optical transmission module, and the light emitted by the transmission module is received by the optical receiving module. The photoelectric conversion module converts the light received by the optical receiving module into an electrical signal. The electrical signal is amplified by the signal amplification module and then output to the central processing module 6 of the fire detector. The light received by the optical receiving module is the light emitted by the optical transmission module and reflected or scattered by smoke particles or interference sources in the air. The central processing module 6 of the fire detector outputs a digital level signal (binary digital signal, varying from 0 to 1), which is input into the signal modulation module and converted into an analog signal to modulate the number of light emissions within a cycle, as well as the current pulse width (light emission time) and current value (light intensity) of each light emission. The digital level signal output by the central processing module 6 modulates the digital level signal (output 0 or 1) according to the signal output by the signal amplification module.

[0105] Among them, under certain conditions, it uses a signal modulation module to dynamically adjust the intensity of the light emitted by the light emitting module (light emitting tube TR). The dynamically modulated light is reflected and scattered by interference sources (small insects, hair, spider silk, dust, dirt, oil smoke, water vapor, dust and suspended particles) and smoke. The reflected light and scattered light are sensed and received by the light receiving module (light receiving tube PT). The received light signal is then used in conjunction with the photoelectric conversion module and the signal amplification circuit to obtain the reflected light and scattered light signals. The light intensity is a function of the particle diameter, shape, refractive index, wavelength of light and the geometric shape of the photoelectric sensor. The amplified signal is then passed through the central processing unit computing chip in the fire detector based on the Mie scattering theory operation method to establish a mathematical model and equation to solve the light intensity at the scattering angle, confirm the characteristics of the smoke particles, and thus identify interference sources such as small insects, hair, spider silk, dust, dirt, oil smoke, water vapor (salt spray), dust (suspended particles), effectively reducing the false alarms of the detector and improving the alarm accuracy of the detector.

[0106] The signal modulation module uses digital level control, and the optical transmitter module regulates current. This is achieved by controlling the current control branch (network numbers I1, I2, ..., In). When I1 is 0, the transmitter current increases; when I2 is 0, the transmitter current increases again. This increase in transmitter current corresponds to an increase in light intensity, while a decrease in transmitter current corresponds to a decrease in light intensity. In the figure, I1...In are extensions of the current control branches I1, I2, and I3. Furthermore, the CPU's P1, I11, I12, I13, P2, I21, I22, and I23 are two sets of transmitter circuit control pins connected to the current control branch and sending digital signals to the signal modulation module. The VOP pin is connected to VCC-OP, and the SKS pin is connected to OUT-OP.

[0107] In addition, the current pulse width is controlled by the level change time of the level change frequency control terminal P, that is, the time from 0 to 1 and from 1 to 0; the number of current pulses is controlled by the level change frequency of the level change frequency control terminal P, that is, the number of changes from 0 to 1 and from 1 to 0. In addition, the pulse width is adjusted to meet the signal bandwidth of the circuit and the distortion of the optical signal; the number of pulses is used to detect the dynamic change characteristics of the particles. In other words, the state and number of particles receiving scattered light and reflected light at the optical receiving module prompt the central processing unit to adjust the light emission time, number and light intensity through the signal modulation module. This results in three specific circuit structures, which are as follows:

[0108] A first embodiment of a signal modulation module includes a VCC power supply terminal 1, a resistor R1, a capacitor C1, a capacitor C2, a resistor R2, a transistor Q1, a transistor Q2, a resistor R3, a resistor R4, and a level change frequency control terminal P. The other end of the resistor R1 is connected to the positive electrode of the optical transmitter module, and the negative electrode of the optical transmitter module is connected to the collector of the transistor Q1. The capacitors C1 and C2 are connected to the connecting line connecting the other end of the resistor R1 to the positive electrode of the optical transmitter module. The collector of the transistor Q2 is respectively connected to the resistor R2 and the base of the transistor Q1. The emitter of the transistor Q1 is connected to one end of the resistor R3 and one end of the resistor R4, and its base is connected to one end of the resistor R2. The emitter of the transistor Q2 is connected to the other end of the resistor R4 and then to ground. The connecting line connecting the other end of the resistor R3 to the base of the transistor Q2 is connected to multiple current control branches. The other end of the resistor R2 is connected to the level change frequency control terminal P. Multiple current control branches are respectively connected by one end of resistors R21, R22, and R23 to the connecting line connected to the other end of the resistor R3 and the base of the transistor Q2, and the other ends of the resistors R21, R22, and R23 are marked I1, I2, and I3; the level change frequency control terminal P is connected to the digital level control terminal P1 and the digital level control terminal P2 of the central processor 6 in the fire detector.

[0109] When a high level is input to the level-changing frequency control terminal P, transistor Q1 conducts, and current I1c flows through resistor R4, causing the voltage across resistor R4 to rise to over 0.7V. This causes Q2 to conduct, causing the base voltage of transistor Q1 to drop, reducing current I1b and, consequently, current I1c, forming a negative feedback circuit in which Q1 and Q2 are in an amplified state. I1c ≈ 0.7 * [(R21 / / R22 / / R23) + R3] / (R21 / / R22 / / R23) / R4. At this point, I1, I2, and I3 are all 0. Signals of I1, I2, and I3 being 0 and I1, I2, and I3 being 1 are all controlled inputs by the fire detector's central processor 6.

[0110] The second embodiment of the signal modulation module includes a VCC power supply terminal 2, a resistor R1', a capacitor C1', a capacitor C2', a resistor R2', a resistor R8, a resistor R9, a transistor Q1', a transistor Q2', a transistor Q3, a transistor Q4, a resistor R3', a resistor R4' and a level change frequency control terminal P'. The VCC power supply terminal 2 is connected to one end of the resistor R1', and the capacitors C1' and C2' are connected to the connecting line connecting the other end of the resistor R1' to the positive electrode of the light emitting module; the negative electrode of the light emitting module is connected to one end of the resistor R8 and the emitter of the transistor Q3; the base of the transistor Q3 is connected to the positive electrode of the resistor R8, respectively. The other end is connected to the collector of transistor Q1', whose collector is respectively connected to one end of resistor R4', one end of resistor R3', and the emitter of transistor Q1. The base of transistor Q1' is respectively connected to one end of resistor R9, the emitter of transistor Q4, and resistor R2'. The base of transistor Q4 is respectively connected to the other end of resistor R9 and the collector of transistor Q2', and its collector, the emitter of transistor Q2', and the other end of resistor R4 are connected to ground. Multiple current control branches are connected to the connecting line connecting the base of transistor Q2' and the other end of resistor R3'. The other end of resistor R2' is connected to level change frequency control terminal P'. Multiple current control branches are connected by one end of resistors R21, R22, and R23 to the connecting line connecting the other end of resistor R3 and the base of transistor Q2, respectively. The other ends of resistors R21, R22, and R23 are labeled I1, I2, and I3. The level change frequency control terminal P' is connected to the digital level control terminal P1 and the digital level control terminal P2 of the central processor 6 in the fire detector.

[0111] This solves the technical problem that the first signal modulation module, which only has transistors Q1' and Q2', has a low amplification factor (β), resulting in poor dynamic characteristics of the circuit. Therefore, transistor Q3 is connected in parallel next to transistor Q1, and transistor Q4 is connected in parallel next to transistor Q2'. In addition, transistors Q1' and Q3 form a Darlington transistor, and transistors Q2' and Q4 also form a Darlington transistor. This improves the amplification factor (β) and improves the dynamic modulation performance. Its I1c ≈ 0.7*[(R21 / / R22 / / R23)+R3'] / (R21 / / R22 / / R23) / R4', at which time I1, I2, and I3 are 0;

[0112] The third embodiment of the signal modulation module includes a VCC power supply terminal 3, a resistor R1", a resistor R2", a resistor R3", a resistor R4", a resistor R5, a capacitor C1", a capacitor C2", a capacitor C3, a transistor Q1", a transistor Q2", a transistor Q3", a field effect transistor Q4, a diode D1, a diode D2 and a level change frequency control terminal P". The VCC power supply terminal 3 is connected to one end of the resistor R1", and the other end of the resistor R1 is connected to the positive electrode of the optical transmitter module. The capacitor C1" and the capacitor C2" are connected to the connecting line connected to the positive electrode of the light emitting module at the other end of the resistor R1", and the negative electrode of the light emitting module is connected to the drain of the field effect transistor Q4; the gate of the field effect transistor Q4 is respectively connected to one end of the capacitor C3, one end of the resistor R3 and the collector of the transistor Q2", and its source is connected to one end of the resistor R4; the emitter of the transistor Q2" is respectively connected to the emitter of the transistor Q1" and the level change frequency control terminal P", and its base is connected to the level change frequency control terminal P. They are respectively connected to the base and collector of transistor Q1"; the collector of transistor Q1" is also connected to the collector of transistor Q3"; the base of transistor Q3" is respectively connected to one end of resistor R2" and the positive electrode of diode D1, and its emitter is connected to the connecting line connected to one end of resistor R5, and multiple current control branches are connected to it; diode D1 and diode D2 are connected in series, and the cathode of diode D2 is respectively connected to the other end of resistor R5, the other end of resistor R3", the other end of capacitor C3 and the ground terminal, and resistor R4" is also connected to the ground terminal; the other end of resistor R2" is connected to the level change frequency control terminal P"; multiple current control branches are respectively connected by one end of resistors R21 and R22 to the connecting line connecting the other end of resistor R3" and the base of transistor Q2", and the other ends of resistors R21 and R22 are marked I1 and I2. The level change frequency control terminal P" is connected to the digital level control terminal P1 and digital level control terminal P2 of the central processor 6 in the fire detector.

[0113] Q1 and Q2 form a current mirror circuit, with Vb clamped in series by D1 and D2, creating a reference voltage of approximately 1.4V. Clearly, I2c ≈ I1c ≈ I3c; therefore, Ic ≈ [(Vb - 0.7) * R3 / (R21 / / R22) - Uon] / R4. At this point, I1 and I2 are 0, and Uon is Q4's minimum on-state voltage. Furthermore, the signals of I1 and I2 being 0 and I1 and I2 being 1 are both controlled by the fire detector's central processing unit (MCU).

[0114] The fourth signal modulation module uses pulse control to dynamically adjust the light emitted by the optical transmitter module. The specific structures are as follows:

[0115] 1) The signal modulation module includes a VCC power supply terminal 4, a digital-to-analog conversion module DAC, a capacitor C4, a capacitor C5, a resistor R6, a resistor R7, a resistor R8, and a Darlington transistor (composed of a transistor Q5 and a transistor Q5); the VCC power supply terminal 4 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to the positive electrode of the light emitting module, the capacitor C4 and the capacitor C5 are connected to the connecting line connecting the other end of the resistor R6 to the positive electrode of the light emitting module, and the negative electrode of the light emitting module is connected to the collector of the Darlington transistor; the base of the Darlington transistor is respectively connected to one end of the resistor R7 and the digital-to-analog conversion module DAC, and its emitter is connected to one end of the resistor R8; and the other end of the resistor R7 and the other end of the resistor R8 are interconnected and then grounded.

[0116] 2) The signal modulation module includes a VCC power supply terminal 4, a digital-to-analog conversion module DAC', a capacitor C4', a capacitor C5', a resistor R6', a resistor R7', a resistor R8', and a field-effect transistor Q5; the VCC power supply terminal 4 is connected to one end of the resistor R6', the other end of the resistor R6' is connected to the positive electrode of the light emitting module, the capacitor C4' and the capacitor C5' are connected to the connecting line connecting the other end of the resistor R6' to the positive electrode of the light emitting module, and the negative electrode of the light emitting module is connected to the drain of the field-effect transistor; the gate of the field-effect transistor is respectively connected to one end of the resistor R7' and the digital-to-analog conversion module DAC', and its source is connected to one end of the resistor R8'; and the other end of the resistor R7' and the other end of the resistor R8' are interconnected and then grounded.

[0117] The two signal modulation modules described above, through programs programmed into the central processing unit, cause the DAC module to generate different analog voltages (Vg), duty cycles, and frequencies, thereby adjusting the transmitting tube's current, pulse width, and pulse count. Therefore, Ic ≈ (Vg - 1.4) / R8; or Ic ≈ (Vg - Uon) / R8, where Uon is the minimum on-state voltage for Q4. Pulse width regulation ensures the circuit's signal bandwidth and maintains optical signal distortion, while pulse count determines the dynamic characteristics of particle detection. The digital-to-analog conversion module (DAC) is connected to digital level control terminals P1 and P2 of the central processing unit 6.

[0118] The structure and principle of the cooperation between the photoelectric conversion module and the signal amplification module are as follows:

[0119] The photoelectric conversion module includes an operational amplifier OP1, a resistor R15 and a capacitor C15; wherein, the input terminal I1- and the input terminal I1+ of the operational amplifier OP1 are respectively connected to the two ends of the optical receiving module; the two ends of the resistor R8 are respectively connected to the input terminal I1- and the output terminal O1 of the operational amplifier OP1, and the capacitor C15 is connected in parallel with the resistor R15.

[0120] The signal amplification module includes an operational amplifier OP2, a resistor R17, and a capacitor C16; wherein, the two ends of the resistor R17 are respectively connected to the output terminal I2- of the operational amplifier OP2 and the output terminal O2 of the operational amplifier OP2, the capacitor C16 is connected in parallel with the resistor R17, and the input terminal I2+ of the operational amplifier OP1 is connected to the voltage divider module.

[0121] It also includes an anti-signal distortion module, and the output end of the photoelectric conversion module is connected to the input end of the signal amplification module through the anti-signal distortion module; the anti-signal distortion module uses a diode D11 or a transistor Q11; wherein, the output end O1 of the operational amplifier OP1 is connected to a capacitor C14, and the input end I1- of the operational amplifier OP2 is connected to a resistor R18; the positive electrode of the diode D11 is connected to the connecting line connecting the capacitor C14 and the resistor R18, and its negative electrode is connected to one end of the capacitor C16; the collector of the transistor Q7 is connected to the connecting line connecting the capacitor C14 and the resistor R18, its emitter is connected to one end of the capacitor C16, and its base is connected to the emitter.

[0122] The device also includes a voltage divider module, the voltage divider circuit of which is connected to the photoelectric conversion module and the signal amplification module respectively. The voltage divider module includes a voltage input terminal VCC-OP, resistors R11, R12, R13, and R14. Resistors R11, R12, R13, and R14 are connected in series. The input terminal I1+ of the operational amplifier OP1 and the negative electrode of the optical receiving module are both connected to the connecting line connecting resistors R12 and R13. Resistor R14 is connected to the input terminal I2+ of the operational amplifier OP2. The voltage of the voltage input terminal VCC-OP is generally 3V or 3.3V, and the operating voltage is 1.8-3.6V.

[0123] The voltage divider module provides different input voltages to the non-inverting terminals I1+ and I2+ of the operational amplifiers OP1 and OP2. By adjusting the values ​​of the four resistors in the voltage divider, the voltage at I1+ is significantly greater than the voltage at I2+ (the voltage at I2+ is approximately the forward conduction voltage of D1 or the normal conduction voltage of Q1). Typically, I1+ is close to VCC-OP, while I2+ is between 0.2V and 0.5V, making the output voltage of O1 significantly greater than the voltage at I2-. Coupling capacitor C8 is rapidly charged unidirectionally through diode D11 or transistor Q11, resulting in a circuit stabilization time of approximately 2ms. Capacitor C14, R18, and R17 form the discharge circuit, and this discharge time determines the signal bandwidth. The signal pulse width lasts for over 200µs, ensuring undistorted optical signals. This resolves the conflict between circuit stabilization time and signal bandwidth, and also addresses the optical signal distortion caused by the increased photoelectric conversion time due to the capacitance characteristics of the photodiode's PN junction.

[0124] The above structure is designed to meet the detection requirements of novel optical mazes, enabling identification of particle size, density, and spatial distribution of particles such as dust, dirt, smoke, water vapor (salt spray), dust (suspended particulates), and smoke. After detection light is reflected or scattered by smoke particles, it passes through a photoelectric conversion module and a signal amplification module to obtain the intensity of the reflected and scattered light. This light intensity is a function of the particle diameter, shape, refractive index, wavelength, and the geometry of the photoelectric sensor. Based on the Mie scattering theory, the fire detector's central processing unit (MCU) then establishes a mathematical model and equation to solve the light intensity at two scattering angles, confirming the characteristics of the smoke particles. This allows identification of interference sources such as small insects, hair, spider silk, dust, dirt, smoke, water vapor (salt spray), and dust (suspended particulates), effectively reducing false alarms and improving the detector's alarm accuracy. Furthermore, the photoelectric conversion module and signal amplification module offer the advantages of fast circuit stabilization time, wide signal bandwidth, and undistorted optical signals.

[0125] As shown in Figures 19-27, a new type of photoelectric smoke fire alarm is mainly formed by the cooperation of two parts: a detector and an optical maze 1; the optical maze 1 includes a base 100, and a maze part is provided on the side of the base 100 close to the detector, and the detector is combined with this side to form a complete alarm.

[0126] As shown in Figures 19 and 20, the detector includes a detection component 3 for detection and an upper cover 2 for accommodating the detection component. The detection component adopts the photoelectric smoke fire alarm detection component as described in any of the above embodiments. The upper cover 2 is hollow inside to form a detection cavity 501, and at least a part of the detection component is accommodated in the detection cavity 501; the upper cover 2 has a first opening 502 and a second opening 503, and at least a part of the detection component is accommodated in the detection cavity 501 through the second opening 503. The second opening 503 cooperates with the bottom plate 400, and the first opening 502 cooperates with the optical maze 1 to allow external smoke to pass through the optical maze and enter the detection cavity 501 to be detected by the detection component. Although Figures 19 and 20 show that the detection component 3 except the base plate 400 is accommodated in the detection cavity 501 of the upper cover 2, and the alarm as a whole is fixed by the base plate 400 of the detection component 3, it does not mean that this is the only way; similar methods such as completely accommodating the detection component 3 in the detection cavity 501 and fixing the alarm as a whole through the upper cover 2 are also feasible.

[0127] As shown in Figures 19 and 20, the overall shape of the upper cover 2 can be a hollow cylinder, the lower surface of which is empty to form a second opening 503, the central area of ​​the upper surface is empty to form a first opening 502, and the internal hollow cavity is formed as a detection cavity 501; at the same time, an annular support platform 504 is provided on the outside of the first opening 502 on the upper surface for the labyrinth part of the base 100 to be set up, and the support platform 504 cooperates with the lower surface of the labyrinth part to avoid contact with the detection cavity to a large extent, so that external light or smoke can only pass through the labyrinth part and then enter the detection cavity 501 to be detected.

[0128] The labyrinth portion has a labyrinth channel 300. Without considering the connectivity of the labyrinth channel 300, the cross-sectional shape of the labyrinth portion can preferably be a shape with a closed boundary, such as a ring, polygon or ellipse; that is, the inside and outside of the labyrinth portion can only be connected through the labyrinth channel 300.

[0129] The labyrinth passage 300 is formed by the cooperation of the first stop 201 and the second stop 202, wherein the first stop 201 includes a first humidification 211 and a second humidification 212, and the second stop 202 includes a third humidification 213 and a fourth humidification 214; the angle between the third humidification 213 and the fourth humidification 214 is an acute angle, preferably 30-60°, and optimally 45°; the angle between the third humidification 213 and the fourth humidification 214 is 45-120°; and after the first stop 201 and the second stop 202 cooperate, the fourth humidification 214 extends into the area between the first humidification 211 and the second humidification 212.

[0130] Furthermore, preferably, the fourth ridge 214 extends to a position near or adjacent to the junction of the first ridge 211 and the second ridge 212, thereby forming a Z-shaped or similar maze-like passageway. In principle, the fourth ridge 214 can be positioned in a variety of locations within the region between the first ridge 211 and the second ridge 212. However, in practice, extending it to or near the junction of the two is the optimal solution, minimizing interference from external light on the detection assembly without affecting gas flow. In this case, the distal end of the fourth ridge 214 is preferably arranged parallel to the second ridge 212, forming a parallel portion 2141, to minimize adverse effects on the gas passageway.

[0131] The cross-sectional shapes of the first, second, third, and fourth ridges 211, 212, 213, and 214 can preferably be straight, arc-shaped, wavy, etc. The first and second stoppers 201, 202 can be manufactured separately and then attached to the base 100 by welding, gluing, snapping, etc., or they can be integrally formed with the base 100; the latter is preferred.

[0132] To ensure effective air exchange between the inside and outside of the fire alarm, the narrowest width of the labyrinth passage 300 should be no less than 1 mm. Specifically, the distance between the front end of the first ridge 211 and the third ridge 213, and the distance between the end of the fourth ridge 214 and either the first ridge 211 or the second ridge 212, should both be no less than 1 mm. This ensures adequate air exchange between the inside and outside of the fire alarm. More preferably, the narrowest width of the labyrinth passage 300 should be no less than 3 mm.

[0133] In addition, a connecting portion is provided between the first stopper 201 and the second stopper 202 of each labyrinth passage 300, so that the entire labyrinth portion except the labyrinth passage is sealed; for example Figure 21 As shown, the second stopper 202 of the preceding labyrinth passage 300 is connected to the first stopper 201 of the following labyrinth passage to close the gap therebetween, forming a basic component unit similar to a "π" shape.

[0134] In some embodiments, the optical maze also includes a chamber 101, which is connected to the detection component. The chamber 101 is arranged at the center position of the maze portion forming a closed shape (only refers to the relative position, not the "center point" or "center area" in the traditional sense), so that the chamber 101 can be connected to the outside world through the maze channel 300.

[0135] In order to prevent external gas (i.e., the environmental gas to be detected) from entering the maze channel 300 from one side of the maze and passing through the chamber 101 and then directly flowing out from the maze channel 300 on the other side (of course, it can also flow out from the maze channel 300 in other directions), thereby reducing the detection effect; a guide member 102 can be set in the chamber 101, and the guide member 102 includes a number of guide plates 1021, so that the external gas changes direction after entering the chamber 101 and flows along the axis direction of the optical maze toward the detection component; at the same time, such a turn can also greatly reduce the interference of external light on the detector.

[0136] In other preferred embodiments, the maze passage 300 is formed by interleaving two adjacent maze blocks 200. Each maze block 200 has the same structure, including a first shank 210, a middle shank 220, and a tail shank 230. The first shank 210 and the tail shank 230 are located at or near the ends of the middle shank 220, and have different orientations. For example, the first shank 210 extends from one end of the second shank 220 to the right, while the third shank 230 extends from the other end of the second shank 220 to the left.

[0137] The maze block 200 can be considered as a further optimization of the aforementioned basic component unit similar to the “π” shape, where the first ridge 211 of the first stopper 201 and the third ridge 213 of the second stopper 202 are overlapped into one part.

[0138] The maze blocks 200 are arranged in a circular pattern and spaced apart in a circumferential direction on one side surface of the base 100. Furthermore, the maze blocks 200 are arranged on the base 100 in the same orientation. Since the maze blocks 200 have a certain height, a ring-shaped protrusion structure is formed on the side surface of the base 100, with the center of the ring forming a chamber 101.

[0139] The angle between the middle ridge 220 and the tail ridge 230 is an acute angle, and the tail ridge 230 of the previous maze block 200 extends into the vicinity of the connection between the first ridge 210 and the middle ridge 220 of the subsequent maze block 200, thereby forming a maze passage 300 between the two; the middle ridge 220 and the tail ridge 230 of the previous maze block 200 are respectively formed as the third ridge 213 and the fourth ridge 214 of the second stopper 202, while the first ridge 210 and the middle ridge 220 of the subsequent maze block 200 are respectively formed as the first stopper 201 including the first ridge 211 and the second ridge 212.

[0140] The cross-section of the labyrinth portion is annular, the cross-section of the first ridge 210 is arc-shaped, and the cross-sections of the middle ridge 220 and the tail ridge 230 are both line segments.

[0141] Obviously, this preferred embodiment is a special case of the above embodiments, and the corresponding structures applicable to the above embodiments are also applicable to this embodiment.

[0142] Furthermore, although in the above embodiments, the first and second stoppers 201, 202, or adjacent maze blocks 200 forming the maze passage 300 are arranged in a circular manner to form a closed geometric shape excluding the maze passage 300, this does not necessarily mean that the optical maze must be arranged in this manner. Alternatively, the first and second stoppers 201, 202, or maze blocks 200 may be provided only in certain directions, and connected by connecting structures. This can also achieve the objectives of the present invention, but the ventilation efficiency may be reduced. For example, for a square-shaped maze portion, a maze passage group of a certain length may be provided only at the four vertices or at the centers of the four sides. Furthermore, the arrangement of the maze passage 300 is not limited to a circular arrangement and may also be in other arrangements such as an array.

Claims

1. A photoelectric smoke fire alarm, comprising a detector and an optical maze, wherein the optical maze comprises a base (100), a maze portion is provided on one side of the base (100), and the detector is fitted on the side to form a fire alarm; characterized in that: The labyrinth portion has a labyrinth passage (300), and the labyrinth passage (300) is formed by the cooperation of a first stopper (201) and a second stopper (202), wherein the first stopper (201) includes a first ridge (211) and a second ridge (212), and the second stopper (202) includes a third ridge (213) and a fourth ridge (214); the angle between the third ridge (213) and the fourth ridge (214) is an acute angle, and the fourth ridge (214) extends to the area between the first ridge (211) and the second ridge (212), and the fourth ridge (214) extends to the connection between the first ridge (211) and the second ridge (212), forming a "Z"-shaped labyrinth passage, and the narrowest width of the labyrinth passage (300) is not less than 1 mm; The maze passage (300) is formed by two adjacent maze blocks (200) arranged at intervals, and the maze blocks (200) include a head (210), a middle (220) and a tail (230); the head (210) and the tail (230) are respectively arranged at the two ends of the middle (220), and the two have different directions; the angle between the middle (220) and the tail (230) is an acute angle, and each maze block (200) is arranged on the base (100) in the same direction; and, The tail ridge (230) of the preceding maze block (200) extends into the area between the first ridge (210) and the middle ridge (220) of the following maze block (200); the middle ridge (220) and the tail ridge (230) of the preceding maze block (200) are respectively formed as the third ridge (213) and the fourth ridge (214) of the second stopper (202), while the first ridge (210) and the middle ridge (220) of the following maze block (200) are respectively formed as the first stopper (201) including the first ridge (211) and the second ridge (212); The detector is a photoelectric smoke fire alarm detection assembly, comprising a base plate (400), on which a first transmitting tube (401), a second transmitting tube (402) and a receiving tube (403) are provided. The first transmitting tube (401) and the second transmitting tube (402) are both matched with the receiving tube (403) in a scattered manner, and the central axes of the first transmitting tube (401) and the second transmitting tube (402) do not overlap. The detection assembly also includes a scattering mechanism, so that the light signals emitted by the first transmitting tube (401) and the second transmitting tube (402) cannot be directly received by the receiving tube (403). The detection component also includes a detection circuit system for modulating the optical signals emitted by the first emitting tube (401) and the second emitting tube (402), so that the current waveforms of the two emitting tubes have at least one current pulse in the same modulation cycle; the first emitting tube (401) and the second emitting tube (402) should respectively have a first current pulse and a second current pulse in the same modulation cycle, the first current pulses of the two emitting tubes are independent of each other, and the second current pulses of the two emitting tubes at least partially overlap; in one modulation cycle, the first emitting tube (401) and the second emitting tube (402) independently transmit according to a predetermined modulation method, and the receiving tube (403) can receive three scattered light intensity data in the modulation cycle.

2. The photoelectric smoke fire alarm according to claim 1, characterized in that: The detection circuit system comprises a signal modulation module (7), a photoelectric conversion module (4) and a signal amplification module (5); a light receiving module (3) is installed at the input end of the photoelectric conversion module (4); a light emitting module (2) is installed on the signal modulation module (7); the output end of the photoelectric conversion module (4) is connected to the input end of the signal amplification module (5); and the output end of the signal amplification module (5) is connected to the input end of the signal modulation module (7); the signal modulation module (7) converts the received digital signal into an analog signal and outputs the analog signal; there are at least two light emitting modules (2).

3. The photoelectric smoke fire alarm according to claim 2, characterized in that: The analog signal emitted by the signal modulation module (7) is received by the light emitting module (2), the light emitted by the light emitting module (2) is received by the light receiving module (3), the photoelectric conversion module (4) converts the light received by the light receiving module (3) into an electrical signal, the electrical signal is amplified by the signal amplification module (5) and then output to the central processing module (6) of the fire detector; the light received by the light receiving module (3) is the light emitted by the light emitting module (2) and reflected or scattered by smoke particles or interference sources in the air; the central processing module (6) of the fire detector outputs a digital level signal and inputs it into the signal modulation module (7) to convert it into an analog signal, so as to modulate the number of light emissions in one cycle, the current pulse width of each light emission number, and the current value.

4. The photoelectric smoke fire alarm according to any one of claims 1 to 3, characterized in that: The scattering mechanism includes an angle control mechanism, which is a light-shielding tube and / or a refractor, and is arranged at the front end of the first emitting tube (401) and / or the second emitting tube (402); or, The scattering mechanism comprises a shielding plate (404), which is arranged on the bottom plate (400) and located between the first transmitting tube (401) and / or the second transmitting tube (402) and the receiving tube (403).

5. The photoelectric smoke fire alarm according to any one of claims 1 to 3, characterized in that: The first launching tube (401), the second launching tube (402) and the receiving tube (403) are arranged on the bottom plate (400) with their respective central axes arranged horizontally.

6. The photoelectric smoke fire alarm according to any one of claims 1 to 3, characterized in that: The first launching tube (401), the second launching tube (402) and the receiving tube (403) are arranged on the bottom plate (400) with their respective central axes tilted.

7. The photoelectric smoke fire alarm according to claim 5, characterized in that: The bottom plate (400) is further provided with a shielding plate (404), and there are two shielding plates (404); one of the shielding plates (404) is provided on a side surface of the front portion of the first transmitting tube (401), so that the optical axis on the side surface of the first transmitting tube (401) is blocked by the shielding plate and is not directly received by the receiving tube (403); the other shielding plate (404) is provided on a side surface of the head portion of the second transmitting tube (402), so that the optical axis on the side surface of the second transmitting tube (402) is blocked by the shielding plate and is not directly received by the receiving tube (403); or, A shielding plate (404) is further provided on the bottom plate (400); the shielding plate (404) comprises a first shielding portion (4041) and a second shielding portion (4041); the first shielding portion (4041) shields part of the emission angle of the first emitting tube (401) so that its optical signal is not directly received by the receiving tube (403); the first shielding portion (4041) and the second shielding portion (4041) jointly shield part of the emission angle of the second emitting tube (402) so that its optical signal is not directly received by the receiving tube (403).

8. The photoelectric smoke fire alarm according to claim 6, characterized in that: The bottom plate (400) is further provided with a shielding plate (404); The shield (404) is in the shape of a long strip and is arranged in a common area between the first transmitting tube (401), the second transmitting tube (402) and the receiving tube (403); and the shield (404) is arranged obliquely in the horizontal direction, so that the optical signals emitted by the first transmitting tube (401) and the second transmitting tube (402) cannot be directly received by the receiving tube (403), but are scattered in a three-dimensional direction after passing over the top of the shield (404).

9. The photoelectric smoke fire alarm according to claim 1, characterized in that: The angle θ1 between the central axis of the first transmitting tube (401) and the central axis of the receiving tube (403) is 10-55°; the angle θ2 between the central axis of the second transmitting tube (402) and the central axis of the receiving tube (403) is 70-140°.

10. The photoelectric smoke fire alarm according to claim 1, characterized in that: The detector further comprises an upper cover (2), the interior of the upper cover (2) being hollow to form a detection cavity (501), and at least a portion of the detection component being accommodated in the detection cavity (501); the upper cover (2) having a first opening (502) and a second opening (503), the second opening (503) being matched with the bottom plate (400), and the first opening (502) being matched with the optical maze to allow external smoke to pass through the optical maze and enter the detection cavity (501) to be detected by the detection component; The optical maze further comprises a chamber (101), the chamber (101) is connected to the detection assembly, and the chamber (101) is arranged at the center of the maze; a flow guide (102) is provided in the chamber (101), and the flow guide (102) comprises a plurality of flow guide plates (1021).

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