Fire detector, disaster prevention facility, and fire detection method

Abstract

To provide a fire detector, a disaster prevention facility, and a fire detection method that enable rapid and appropriate fire detection according to an identified type of smoke.SOLUTION: In a disaster prevention facility, a signal detection unit 16 of a detector 12 detects multiple signals as optical effects, such as scattering caused by detection targets like smoke or steam within a monitored area, using multiple optical settings. An identification unit 18 identifies a type or cause of detection targets, such as white smoke, black smoke, or steam, based on the ratio of the multiple signals. A fire detection unit 20 detects a fire when predetermined fire detection conditions are met based on at least one of the multiple signals. Furthermore, fire detection conditions are modified according to the identification results such as white smoke, black smoke, and steam determined by the identification unit 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fire detection device such as a smoke detector that detects a fire from the optical effect of smoke, a disaster prevention facility, and a fire detection method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, fire detection devices such as smoke detectors that receive scattered light with different scattering angles and different wavelengths to identify the type of smoke are known.

[0003] For example, by varying the scattering angle of two light-emitting elements relative to the light-receiving element, differences in scattered light depending on the type of smoke can be created, and at the same time, by varying the wavelength of the light emitted from the two light-emitting elements, differences in scattering characteristics due to wavelength can be created.The synergistic effect of these differences in scattering angle and wavelength creates a significant difference in the light intensity of the scattered light depending on the type of smoke, thereby increasing the accuracy of smoke identification and preventing false fire alarms caused by cooking steam, etc., and also making it possible to reliably identify the type of burning material, such as black smoke fires and white smoke fires, when it comes to smoke from fires. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-325211 [Patent Document 2] Japanese Patent Publication No. 2020-035029 [Patent Document 3] Japanese Patent Publication No. 2020-135263 [Patent Document 4] US Patent Application Publication No. 2001 / 0020899 [Patent Document 5] Japanese Patent Application Publication No. 05-081578 [Patent Document 6] Japanese Patent Application Publication No. 11-160238 [Patent Document 7] Japanese Patent Application Laid-Open No. 2013-109751 [Patent Document 8] Japanese Patent Application Laid-Open No. 2016-114959 [Patent Document 9] Japanese Patent Application Publication No. 2019-220113 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while such conventional fire detection devices that distinguish between types of smoke can distinguish between black smoke fires and white smoke fires, there is room for improvement in terms of appropriate fire detection according to the type of smoke. For example, for black smoke fires, which are expected to spread more rapidly than white smoke fires, the devices cannot be said to have sufficient performance in terms of quickly detecting them as fires and quickly outputting a fire signal.

[0006] An object of the present invention is to provide a fire detection device, disaster prevention equipment, and fire detection method that enable quick and appropriate fire detection according to the type of smoke identified. [Means for solving the problem]

[0007] (Fire detection equipment) The present invention provides a fire detection device, A signal detection means for detecting a signal associated with the optical action of a detection target in a monitoring area by a plurality of optical settings, the signal detection means detecting a plurality of signals obtained by the plurality of optical settings; an identification means for identifying the type of detection target or the type of cause of the detection target based on the plurality of signals detected by the signal detection means; a fire detection means for detecting a fire when a predetermined fire detection condition is satisfied based on at least one of the plurality of signals detected by the signal detection means; Equipped with The fire detection condition is changed depending on the identification result by the identification means. It is characterized by:

[0008] Here, "identifying the type of detection target based on a plurality of signals" is a concept that includes, for example, identification by comparing a plurality of signals, and more specifically, identification based on the magnitude relationship of a plurality of signals, identification based on a plurality of ratios, etc.

[0009] (Identification of detection target) the identification means identifies a type of detection target as a fire detection target and a non-fire detection target; The fire detection conditions are: When a fire detection target is identified by the identification means, the fire detection means is changed so that the fire detection condition is more likely to be detected as a fire than the fire detection condition initially set by the fire detection means, When the discrimination means discriminates a non-fire detection target, the fire detection means changes the fire detection conditions so that the non-fire detection target is less likely to be detected as a fire than the initially set fire detection conditions.

[0010] Here, "fire detection targets" refer to particles and the like that should be detected as fires in the monitored area, such as smoke generated by a fire. Examples of types of smoke include white smoke and black smoke. White smoke is whitish smoke generated by, for example, wood or cloth smoldering, while black smoke is darkish smoke generated by, for example, an object igniting and burning. Known combustion materials for fires primarily accompanied by white smoke (white smoke fires) include wood and cotton wicks, while known combustion materials for fires primarily accompanied by black smoke (black smoke fires) include kerosene. Furthermore, "non-fire detection targets" refer to particles and the like that should not be detected as fires, such as oil smoke, steam, vapor, dust, and cigarette smoke that are generated by factors other than fires (non-fire factors). Factors that generate oil smoke, steam, and steam that are non-fire detection targets include cooking, boiling water, and using the bathroom, while dust factors include cleaning and dust, and cigarette smoke is generated by smoking.

[0011] Here, "making it easier to detect a fire" means, for example, that a fire will be detected under looser (relaxed) conditions, which will result in, for example, a fire being detected sooner. Also, "making it harder to detect a fire" means, for example, that a fire will be detected under stricter (strengthened) conditions, which will result in, for example, a fire being detected later. In other words, "changing the fire detection conditions" means, in the former case, relaxing the conditions for detecting a fire, and in the latter case, strengthening the conditions for detecting a fire.

[0012] (Distinguishing between white and black smoke) The discrimination means discriminates between white smoke and black smoke as fire detection targets, The fire detection conditions are: When white smoke is identified by the identification means, the fire detection means is changed to be more likely to detect a fire than the initial fire detection conditions, When the discrimination means discriminates black smoke, the fire detection means changes the fire detection conditions so that the fire is more likely to be detected as a fire than the changed fire detection conditions resulting from the discrimination of white smoke.

[0013] (Detecting growth rate) further comprising an increase rate detection means for detecting an increase rate of at least one of the plurality of signals; The fire detection condition is changed based on the identification result by the identification means and the increase rate by the increase rate detection means.

[0014] (Change of fire detection conditions according to the rate of increase) The fire detection conditions are changed so that when the identification means identifies a fire detection target as a type of detection target and the increase rate detected by the increase rate detection means satisfies a predetermined increase rate threshold condition, the fire detection means is more likely to detect a fire than before the change.

[0015] (First disaster prevention equipment) The present invention is a disaster prevention system using the above-mentioned fire detection device, a receiver and a detector that detects a fire and transmits a fire signal to the receiver; The detector is characterized by comprising a signal detection means, a discrimination means and a fire detection means, or a signal detection means, a discrimination means, a fire detection means and an increase rate detection means.

[0016] (Second disaster prevention equipment) The present invention is a disaster prevention system using the above-mentioned fire detection device, a receiver and a detector that detects a fire and transmits a fire signal to the receiver; The sensor comprises a signal detection means; The receiver is characterized by comprising an identification means and a fire detection means, or an identification means, a fire detection means and an increase rate detection means.

[0017] (Fire detection method) The present invention provides a fire detection method for detecting a fire in a monitored area, comprising: A signal detection means detects signals associated with optical actions of a detection target in a monitoring area by a plurality of optical settings, and detects a plurality of signals obtained by the plurality of optical settings; The discrimination means discriminates between a fire detection target and a non-fire detection target as the type of detection target based on the plurality of signals detected by the signal detection means, and discriminates between white smoke and black smoke as the type of fire detection target; a fire detection means for detecting a fire when a predetermined fire detection condition is satisfied based on at least one of the plurality of signals detected by the signal detection means; Fire detection conditions are: When the discrimination means discriminates white smoke as a fire detection target, the fire detection means changes the fire detection conditions so that the fire detection conditions are more likely to be detected as a fire than the initial settings of the fire detection conditions, When the discrimination means discriminates black smoke as a fire detection target, the fire detection means changes the fire detection conditions so that the black smoke is more likely to be detected as a fire than the changed fire detection conditions associated with the discrimination of white smoke; When the discrimination means discriminates a non-fire detection target, the fire detection means changes the fire detection conditions so that the fire detection condition becomes less likely to be detected as a fire than the initially set fire detection conditions.

[0018] (Detection of increase rate and change of fire detection conditions) 1. A fire detection method comprising: detecting an increase rate of at least one of the plurality of signals by an increase rate detection means; The fire detection conditions are changed based on the identification result by the identification means and the increase rate by the increase rate detection means. [Effects of the Invention]

[0019] (Effectiveness of fire detection devices) According to the fire detection device of the present invention, by changing the fire detection conditions according to the type of detection target, such as white smoke, black smoke, or steam, or the type of cause of these detection targets, fires caused by smoke that are more dangerous and have the potential to spread quickly and become large in scale are detected as fires more quickly, while false fire alarms can be reliably prevented for steam and other non-fire-related causes.

[0020] (Effect of identifying the detection target) Furthermore, when a fire detection target such as white smoke or black smoke is identified, the fire detection conditions are changed to make it easier to detect a fire, enabling prompt fire detection and response. Furthermore, when a non-fire detection target such as steam or dust is identified, the fire detection conditions are changed to make it harder to detect a fire, ensuring the prevention of false fire alarms.

[0021] (Effect of distinguishing between white and black smoke) Furthermore, when white smoke is identified, the fire detection conditions are changed to make it easier to detect a fire than before the change, enabling prompt fire detection and response.On the other hand, when black smoke is identified, the fire detection conditions are changed to make it easier to detect a fire than the changed fire detection conditions associated with white smoke, enabling more rapid detection and response of highly dangerous black smoke fires than white smoke fires.

[0022] (Detection of the increase rate and the effect of changing the fire detection conditions according to the increase rate) In addition, by changing the fire detection conditions so that they are more likely to be detected as fires than before the change, depending on the rate of increase in the signal (at least one of multiple signals) from the fire detection target in the monitored area due to the action of light, fires that are likely to become larger in scale and whose smoke spreads (rises) quickly can be detected more quickly.

[0023] (Effect of changes to fire detection conditions) Furthermore, if the fire detection conditions are changed so that fires are more easily detected than before, the specified threshold conditions and / or accumulation conditions can be made more lenient than before, i.e., the fire detection conditions can be changed to increase detection sensitivity, thereby enabling appropriate fire detection for low-risk white smoke fires and high-risk black smoke fires.On the other hand, if the fire detection conditions are changed so that fires are more difficult to detect than before, the fire threshold conditions and / or accumulation conditions can be made stricter than before, i.e., the fire detection conditions can be changed to lower detection sensitivity, thereby reliably preventing false fire alarms caused by steam from cooking or dust from cleaning.

[0024] (Effect of the first disaster prevention equipment) The present invention is a disaster prevention facility that uses the above-mentioned fire detection device, and comprises a receiver and a detector that detects a fire and transmits a fire signal to the receiver. By providing the detector with a signal detection means, an identification means, and a fire detection means, or a signal detection means, an identification means, a fire detection means, and an increase rate detection means, the problem can be addressed by simply changing the detector. Even in the case of existing equipment, the problem can be easily addressed by removing the detector attached to the detector base and replacing it with a detector that is equipped with a signal detection means, an identification means, and a fire detection means, or a detector that is also equipped with an increase rate detection means.

[0025] (Effect of the second disaster prevention equipment) The present invention is a disaster prevention facility that uses the above-mentioned fire detection device, and comprises a receiver and a detector that detects a fire and transmits a fire signal to the receiver, and the detector is provided with a signal detection means, and the receiver is provided with an identification means and a fire detection means, or an identification means, a fire detection means and an increase rate detection means, thereby eliminating the need to modify the detector and allowing the problem to be addressed by modifying only the receiver.

[0026] (Effectiveness of fire detection methods) The present invention, as a fire detection method, can provide the same effects as the above-described fire detection device. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is an explanatory diagram showing the basic concept of a fire detection device, a disaster prevention facility, and a fire detection method according to the present invention. [Figure 2] 2 is an explanatory diagram of a disaster prevention facility showing a specific embodiment of the present invention targeted at a P-type disaster prevention facility corresponding to FIG. 1. FIG. [Figure 3] FIG. 2 is an explanatory diagram showing a smoke detector unit equipped with a signal detector. [Figure 4] This is an explanatory diagram showing in list form the type of detection target based on the first detection value and the second detection value, the cause of occurrence, the identification conditions, changes to fire detection conditions according to the identification results, and changes to fire detection conditions based on the detection of the increase rate. [Figure 5] 10 is a time chart showing the characteristics of the change over time in smoke concentration with different increase rates. [Figure 6] 3 is a flowchart illustrating a control operation according to an embodiment of the sensor of FIG. 2. [Figure 7] FIG. 10 is an explanatory diagram showing another basic concept of the fire detection device, disaster prevention equipment, and fire detection method of the present invention, which detects a fire on the receiver side. [Figure 8] 8 is an explanatory diagram of a disaster prevention facility showing a specific embodiment of the present invention that is directed to an R-type disaster prevention facility corresponding to FIG. 7. [Figure 9] 9 is a flowchart showing, in the form of a time chart, a control operation according to the embodiment of the R-type disaster prevention equipment of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fire detection device, a disaster prevention system, and a fire detection method according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to these embodiments.

[0029] [Basic concept of the embodiment] Fig. 1 is an explanatory diagram showing the basic concept of an embodiment of the present invention corresponding to the first disaster prevention facility, and the basic concept of the embodiment will be described with reference to Fig. 1. This embodiment generally relates to a fire detection device, a first disaster prevention facility, and a fire detection method. Note that an embodiment corresponding to the second disaster prevention facility will be described separately.

[0030] The term "fire detection device" refers to a device that detects fires in a monitored area, and is a concept that includes, for example, smoke detectors, fire detectors, fire alarms, and the like.

[0031] Here, the term "monitored area" refers to an area that is monitored by a fire detection device, and is an outdoor or indoor space with a certain extent, and is a concept that includes spaces such as rooms, corridors, and staircases in a building.

[0032] An example of a fire detection device is a detector 12 of a disaster prevention facility that is composed of a receiver 10 and a detector 12, and is basically equipped with a signal detection unit 16 that functions as a signal detection means, an identification unit 18 that functions as an identification means, and a fire detection unit 20 that functions as a fire detection means, and further equipped with an increase rate detection unit 22 that functions as an increase rate detection means.

[0033] The "signal detection unit 16" detects signals associated with the optical action of the detection object in the monitoring area using at least a first optical setting and a second optical setting, and detects a first signal obtained by the first optical setting and a second signal obtained by the second optical setting.

[0034] Here, the term "detection target in the monitoring area" refers to a detection target that generates a signal due to the action of light, for example, a detection target that generates scattered light when irradiated with light, and is a concept that includes smoke from a fire, steam or vapor from cooking which are non-fire factors, dust from cleaning, and cigarette smoke from smoking.

[0035] The term "first optical setting" includes, for example, a method of irradiating a detection target in a monitoring area with light of a first wavelength, receiving scattered light at a first scattering angle, and detecting, as a first signal, a light-receiving signal obtained by such irradiation. The term "second optical setting" includes, for example, a method of irradiating a detection target in a monitoring area with light of a second wavelength different from the first wavelength, receiving scattered light at a second scattering angle different from the first scattering angle, and detecting, as a second signal, a light-receiving signal obtained by such irradiation. The first and second optical settings, for example, can create differences in scattered light depending on the type of smoke by differentiating the scattering angles of two light-emitting elements relative to the light-receiving elements, and at the same time, create differences in scattering characteristics due to wavelength by differentiating the wavelengths of light emitted from the two light-emitting elements, and detect first and second signals that have significant differences in the light intensity of scattered light depending on the type of smoke due to the synergistic effect of the differences in scattering angles and wavelengths.

[0036] The “identification unit 18” identifies the type of the detection target or the type of the cause of the detection target based on the first signal and the second signal detected by the signal detection unit 16.

[0037] Here, the "type of detection target" is a concept that includes white smoke and black smoke that are fire detection targets, and steam (vapor), dust, etc. that are non-fire detection targets. Also, the "type of cause of detection target" is a concept that includes, for example, white smoke fire, black smoke fire, and non-fire (such as cooking as mentioned above) that correspond to each detection target.

[0038] The "fire detection unit 20" is a unit that detects a fire when a predetermined fire detection condition is met based on at least one of the first signal and the second signal detected by the signal detection unit 16, and is a concept that includes, for example, a unit that detects a fire when at least one of the first signal and the second signal meets a predetermined threshold condition, or when at least one of the first signal and the second signal meets a predetermined accumulation condition while meeting a predetermined threshold condition.

[0039] Here, "based on at least one of the first signal and the second signal" is a concept that includes, for example, identifying by comparing the first signal and the second signal, and more specifically, identifying based on the magnitude relationship between the first signal and the second signal, or identifying based on the ratio between the first signal and the second signal, etc.

[0040] Here, the "fire detection conditions" are conditions for detecting a fire based on at least one of the first signal and the second signal detected by the signal detection unit 16, and are changed depending on the identification result by the identification unit 18.

[0041] Furthermore, "changed according to the identification result by the identification unit 18" means that the fire detection conditions are changed according to the type of detection target or the type of cause of the detection target obtained as the identification result.

[0042] The change of the fire detection conditions according to the identification result of the identification unit 18 is optional, but as an example, the concept includes the identification unit 18 identifying the types of detection targets as fire detection targets and non-fire detection targets, and when a fire detection target is identified, the fire detection conditions are changed so that it is easier to detect as a fire than before, and on the other hand, when a non-fire detection target is identified, the fire detection conditions are changed so that it is harder to detect as a fire than before.

[0043] As another example, the fire detection conditions are changed so that when white smoke is identified by the identification unit 18, it is easier to detect a fire than before the change, and when black smoke is identified by the identification unit 18, the fire detection conditions are changed so that it is easier to detect a fire than the fire detection conditions after the change associated with the identification of white smoke, and this concept includes enabling more rapid fire detection for black smoke fires, which are more dangerous, than for white smoke fires.

[0044] Here, "changed to make it easier to detect fires than before the change" means changing the fire detection conditions to conditions that are more lenient and increase the detection sensitivity. As an example, if at least one of the first signal and the second signal has a predetermined threshold condition and / or accumulation condition, this includes changing the threshold condition and / or accumulation condition before the change to a more lenient condition (loose condition) so that fires can be more easily detected and the detection sensitivity can be increased.

[0045] Furthermore, "changed so that it is more difficult to detect a fire than before the change" means changing the fire detection conditions to conditions that are stricter and the detection sensitivity is lowered. As an example, if at least one of the first signal and the second signal has a predetermined threshold condition and / or accumulation condition set, this includes lowering the detection sensitivity by making the smoke value threshold condition and / or accumulation condition before the change stricter (to a stricter condition) so that it is more difficult to detect a fire.

[0046] The "increase rate detection unit 22" detects the increase rate of at least one of the first signal and the second signal detected by the signal detection unit 16. Here, "detecting the increase rate" is a concept that includes detecting the amount of change in the detected value (e.g., smoke concentration) of at least one of the first signal and the second signal per predetermined unit time.

[0047] Furthermore, with the inclusion of the increase rate detection unit 22, the fire detection conditions are changed based on the identification result by the identification unit 18 and the increase rate by the increase rate detection unit 22. The change in the fire detection conditions in this case is arbitrary, but as an example, the concept includes changing the fire detection conditions so that a fire is more likely to be detected than before the change when a fire detection target is identified as the type of detection target and the increase rate satisfies a predetermined increase rate threshold condition. For example, when white smoke or black smoke, which is a fire detection target, is identified, the initially set fire detection conditions are changed so that a fire is more likely to be detected depending on whether the smoke is white or black. However, when a predetermined increase rate threshold condition is satisfied, the changed fire detection conditions are changed so that a fire is even more likely to be detected. As a result, even if the fire is the same as white smoke or black smoke, the higher the increase rate of at least one of the first signal and the second signal, for example, the increase rate of the detection value (smoke density), the more quickly the fire can be detected.

[0048] In the following description, the "monitoring area" is a "room in a building," the "signal detection unit 16" is a "scattered light type smoke detector that detects a first signal and a second signal using different wavelengths and different scattering angles," the "identification unit 18" is "a unit that identifies the type of detection target or the type of cause of the detection target based on the ratio between the first detection value A1 and the second detection value A2 corresponding to the smoke density of the first signal and the second signal," and the "fire detection unit 20" is "a unit that detects a fire when a predetermined threshold condition of the smoke density is satisfied," We will explain the case where the ``increase rate detection unit 22'' ``detects the increase rate α1, α2 of at least one of the first detection value A1 and the second detection value A2'' and the ``change in fire detection conditions'' is ``performed by the fire detection unit 20.''

[0049] [Specific details of the embodiment] The specific contents of the embodiments of the fire detection device, the disaster prevention equipment, and the fire detection method will be described in more detail below. aP-type disaster prevention equipment a1.Receiver a2.Sensor a3. Signal detection section a4. Light emission drive and light reception detection a5. Sensor control section a6. Fire detection section b. Identifying the type of detection target and changing the fire detection conditions b1.Identification part b2. Identifying white smoke b3. Identification of black smoke b4. Identification of non-fire detection targets c. Detection of increase rate and change of fire detection conditions c1. Increase rate detection section c2. Changing the fire detection criteria based on the rate of increase d. Sensor control operation e. Basic Concept of Other Embodiments fR-type disaster prevention equipment f1.sensor f2.Receiver f3.Transmission control f4. Control operation of R-type disaster prevention equipment g. Modifications of the present invention

[0050] [aP-type disaster prevention equipment] Fig. 2 is an explanatory diagram showing a specific embodiment of the present invention targeted at a proprietary-type (P-type) disaster prevention facility corresponding to Fig. 1. Here, the "P-type disaster prevention facility" refers to a facility in which a receiver 10 monitors fires for each signal line (each signal line) to which a detector 12 is connected.

[0051] As shown in Fig. 2, the P-type disaster prevention equipment of this embodiment includes a receiver 10 and multiple sensors 12. Note that Fig. 2 shows only one sensor 12 as a representative. The receiver 10 is installed in a manager's office, a disaster prevention center, or the like, and multiple sensors 12 are connected to a signal line 14 that is drawn from the receiver 10 to a monitored area such as a room in a building. The signal line 14 drawn from the receiver 10 includes a positive signal line 14a and a negative signal line (common signal line) 14b, and supplies power from the receiver 10 to the sensors 12 and transmits a fire alert signal from the sensors 12 to the receiver 10.

[0052] (a1. Receiver) The receiver 10 comprises a receiver control unit 40, a line receiving unit 42, a display unit 44, an operation unit 46, an alarm unit 48, and a report transfer unit 50. The line receiving units 42 are provided for each signal line 14 drawn out in a monitored area, for example, for each floor of a building, and receive fire alert signals from the detectors 12 and output them to the receiver control unit 40.

[0053] The receiver control unit 40 is composed of a computer circuit equipped with a CPU, memory, and various input / output ports, and performs a fire alarm operation when it detects the reception of a fire alarm signal by any of the line receiving units 42. The fire alarm operation of the receiver control unit 40 activates the fire representative light on the display unit 44 and activates the district indicator light that indicates the district where the fire has occurred, outputs a main sound alarm including an alarm voice message by the alarm unit 48, and performs a district sound alarm by activating the district sounding device installed in the monitored area where the fire has occurred, and also instructs the reporting unit 50 to perform interlocking control of smoke prevention and exhaust equipment, etc.

[0054] (a2.sensor) The configuration of the sensor 12 that functions as a fire detection device will be described in more detail below. The sensor 12 includes a signal detection unit 16, a sensor control unit 24, an alarm circuit unit 26, a power supply unit 28, a light-emitting driver unit 36, and a light-receiving amplifier unit 38.

[0055] (a3. Signal detection section) The signal detection unit 16 detects a first detection value A1 based on a first signal obtained by irradiating smoke, steam, dust, etc., which are to be detected in the monitored area, with light of a first wavelength λ1 and receiving the scattered light obtained at a first scattering angle θ1 using a first optical setting, and detects a second detection value A2 based on a second signal obtained by irradiating light of a second wavelength λ2, which is different from the first wavelength λ1, with a second optical setting and receiving the scattered light obtained at a second scattering angle θ2, which is different from the first scattering angle θ1.The configuration and structure of the signal detection unit 16 are arbitrary, but for example, the first light-emitting element 30, the second light-emitting element 32, and the light-receiving element 34 are arranged in a smoke detection unit, which is a space provided inside the sensor into which outside air flows but which is blocked from outside light.

[0056] 3A and 3B are explanatory diagrams showing the smoke detection section of the signal detection section 16, with FIG. 3A showing a first embodiment and FIG. 3B showing a second embodiment.

[0057] As shown in Figure 3(A), in this embodiment, a first light-emitting element 30, a second light-emitting element 32, and a light-receiving element 34 are arranged in a smoke detection section 31 into which smoke from the outside flows in and which is shielded from light from the outside, and this embodiment has a planar arrangement structure in which the respective optical axes 30a, 32a, 34a are arranged in the same plane.

[0058] A near-infrared LED is used as the first light-emitting element 30, and emits light with a center wavelength of 600 nm or more, for example, λ1=900 nm, as light with a first wavelength λ1. The first light-emitting element 30 has a first scattering angle θ1 with respect to an intersection P between its optical axis 30a and the optical axis 34a of the light-receiving element 34, which is set to a predetermined angle in the range of 20° to 70°, for example, θ1=30°.

[0059] The second light-emitting element 32 is a visible light LED, and emits light with a center wavelength of 500 nm or less, for example, λ2=500 nm, as light of the second wavelength λ2. The second light-emitting element 32 has a second scattering angle θ2 relative to an intersection P between its optical axis 32a and the optical axis 34a of the light-receiving element 34, which is set to a predetermined angle in the range of 110° to 150° that is larger than the first scattering angle θ1 of the first light-emitting element 30 and the light-receiving element 34, for example, θ2=120°.

[0060] A photodiode having sensitivity in the infrared to visible light range is used for the light receiving element 34. The first light emitting element 30 and the second light emitting element 32 are driven to emit light alternately. When the first light emitting element 30 emits light of a first wavelength λ1, the smoke that has flowed into point P is irradiated with light, and the scattered light (forward scattered light) from the smoke corresponding to a first scattering angle θ1 is incident on and received by the light receiving element 34, a first signal is output as a light receiving signal, and a first detection value A1 corresponding to the smoke concentration is detected.

[0061] Furthermore, when the light of the second wavelength λ2 is emitted by the second light-emitting element 32 and irradiated onto the smoke that has flowed into point P, the scattered light (backscattered light) from the smoke corresponding to the second scattering angle θ2 is incident on and received by the light-receiving element 34, a second signal is output as a received light signal, and a second detection value A2 corresponding to the smoke concentration is detected.

[0062] Here, based on the difference in scattering efficiency, there is a difference between a first detection value A1 of scattered light received at a first scattering angle θ1 = 30° when light of a first wavelength λ1 = 900 nm is irradiated onto the same smoke, and a first detection value A2 of scattered light received at a second scattering angle θ2 = 120° when light of a second wavelength λ2 = 500 nm is irradiated onto the same smoke, as follows: A1>A2 It is known that the relationship

[0063] Furthermore, the first detection value A1 and the second detection value A2 will be different depending on the type of smoke that has flowed into the smoke detector 31, for example, white smoke, black smoke, steam, etc., and the type of smoke can be identified by comparing the first detection value A1 and the second detection value A2. The type of smoke can be identified by comparing the first detection value A1 and the second detection value A2 in any way, but for example, the ratio R of the two can be set as follows: R=A1 / A2 It can be identified by finding

[0064] For example, for white smoke (smoldering smoke), which is whitish smoke when a cotton wick is burned, the ratio R between the first detection value A1 and the second detection value A2 is, for example, R = 8.0. On the other hand, for black smoke (combustion smoke), which is dark smoke when kerosene is burned, the ratio R between the first detection value A1 and the second detection value A2 is, for example, R = 2.3.

[0065] For this reason, there is a sufficient difference between the ratio R of the first detection value A1 and the second detection value A2 for white smoke (smoldering smoke) and black smoke (combustion smoke). For example, by setting a value in the range of 5 to 6 as the first discrimination threshold Rth1 for discriminating the type of smoke for the ratio R, for example Rth1=5, it is possible to discriminate between white smoke if the ratio R is Rth1 or greater, and black smoke if it is less than Rth1.

[0066] On the other hand, in the case of steam or vapor, the particle diameter is sufficiently larger than that of smoke particles, and therefore the scattering efficiency at small scattering angles is sufficiently higher than that of smoke during a fire, and the first detection value A1 caused by scattered light irradiated with light of the first wavelength λ1 at a first scattering angle θ1 = 30° is sufficiently large, and the ratio R to the second detection value A2 caused by scattered light irradiated with light of the second wavelength λ2 at a second scattering angle θ2 = 120° is a large value of 10 or more.

[0067] For this reason, a second discrimination threshold Rth2 for discriminating steam or vapor is set to a value in the range of 10 to 12, for example Rth2=12, and values ​​above this can be discriminated as non-fire detection targets such as steam or vapor.

[0068] The same is true for cigarette smoke and dust, and since a large value of the ratio R of 10 or more is obtained, when the second discrimination threshold Rth2 is 12 or more, it can be discriminated as a non-fire detection target.

[0069] Next, a second embodiment of the smoke detector unit shown in Fig. 3(B) will be described. As shown in Fig. 3(B), in this embodiment, a light-emitting element 35, a first light-receiving element 34 (34-1), and a second light-receiving element 34 (34-2) are arranged in the smoke detector unit 31, and this example has a planar arrangement structure in which the respective optical axes 35a, 34-1a, 34-2a are arranged in the same plane.

[0070] The light-emitting element 35 simultaneously emits light including a first wavelength λ1 and a second wavelength λ2, and the light of the first wavelength λ1 emitted from the light-emitting element 35 is set to have a central wavelength of 600 nm or more, and the light of the second wavelength λ2 is set to have a central wavelength of 500 nm or less.In this embodiment, the first wavelength λ1 is set to, for example, 700 nm, and the second wavelength λ2 is set to, for example, 450 nm.

[0071] The light emitting element 35 emits light in the infrared to visible light range, and may have any structure or type, but may be, for example, a white LED (white light emitting diode). The white LED may be, for example, a combination of a blue LED and a phosphor, and emits white light by passing the light from the blue LED through the phosphor. This emitted light contains light with a first wavelength λ1=700 nm and light with a second wavelength λ2=450 nm, and the light with the first wavelength λ1 and the second wavelength λ2 can be emitted simultaneously into the smoke detection unit 31.

[0072] Furthermore, a two-color LED (two-color light-emitting diode) can also be used as the light-emitting element 35 of this embodiment. The two-color LED includes a first light-emitting chip that emits light with a first wavelength λ1=700 nm and a second light-emitting chip that emits light with a second wavelength λ2=450 nm, and by driving both chips simultaneously, the smoke detecting unit 31 can be simultaneously irradiated with light of the first wavelength λ1 and the second wavelength λ2.

[0073] The first light receiving element 34 (34-1) uses a photodiode (PD) sensitive to the first wavelength λ1, and the second light receiving element 34 (34-2) uses a photodiode (PD) sensitive to the second wavelength λ2.

[0074] Furthermore, the first light receiving element 34 (34-1) and the second light receiving element 34 (34-2) may be a wideband photodiode sensitive to the visible light wavelength band, with a filter layer that receives only the first wavelength λ1 and the second wavelength λ2 provided on the PD molding (transparent cover member), or a filter that transmits the first wavelength λ1 and the second wavelength λ2 may be placed in front of the wideband photodiode.

[0075] The first light-receiving element 34 (34-1) has a first scattering angle θ1 with respect to an intersection P of its optical axis 34-1a and the optical axis 35a of the light-emitting element 35 set to a predetermined angle in the range of 20° to 70°, for example θ1 = 30°. When light including a first wavelength λ1 is irradiated from the light-emitting element 35 to the smoke that has flowed into point P, scattered light (forward scattered light) from the smoke corresponding to the first scattering angle θ1 is incident on and received by the first light-receiving element 34 (34-1), a first signal is output as a light-receiving signal, and a first detection value A1 corresponding to the smoke concentration is detected.

[0076] The second light-receiving element 34 (34-2) has a second scattering angle θ2 with respect to an intersection P between its optical axis 34-2a and the optical axis 35a of the light-emitting element 35, which is set to a predetermined angle in the range of 110° to 160°, for example, θ2 = 120°, which is larger than the first scattering angle θ1 of the first light-receiving element 34 (34-1) and the light-emitting element 35. When light including the second wavelength λ2 is irradiated from the light-emitting element 35 to the smoke that has flowed into point P, scattered light (backscattered light) from the smoke corresponding to the second scattering angle θ2 is incident on and received by the second light-receiving element 34 (34-2), a second signal is output as a light-receiving signal, and a second detection value A2 corresponding to the smoke concentration is detected.

[0077] In this embodiment, the first detection value A1 of scattered light received at a first scattering angle θ1=30° when light of a first wavelength λ1=700 nm is irradiated onto the same smoke, and the first detection value A2 of scattered light received at a second scattering angle θ2=120° when light of a second wavelength λ2=450 nm is irradiated onto the same smoke, are calculated based on the difference in scattering efficiency. A1>A2 The first discrimination threshold Rth1 is set to, for example, Rth1=5, and smoke equal to or greater than Rth1 can be discriminated as white smoke, and smoke less than Rth1 can be discriminated as black smoke.

[0078] In addition, for steam, vapor, dust, cigarette smoke, etc., a second discrimination threshold Rth2 is set, for example, to Rth2=12, and anything above this can be identified as a non-fire detection target such as steam, vapor, dust, cigarette smoke, etc.

[0079] (a4. Light emission drive and light reception detection) 2 is provided with the first embodiment of the smoke detector shown in Fig. 3(A), and is therefore provided with a first light-emitting element 30, a second light-emitting element 32, and a light-receiving element 34. The first light-emitting element 30 and the second light-emitting element 32 are driven to emit light alternately at predetermined intervals by a light-emitting drive unit 36, and the first and second signals output sequentially from the first light-emitting element 30 and the second light-emitting element 32 as received light signals are amplified by a received light amplifier unit 38 and read into the sensor control unit 24, where a first detection value A1 and a second detection value A2 corresponding to the smoke density are detected.

[0080] (a5. Sensor control section) The detector control unit 24 is composed of a computer circuit equipped with a CPU, memory, and various input / output ports, and has the functions of an identification unit 18, a fire detection unit 20, and an increase rate detection unit 22, which are components of the fire detection device of this embodiment, as functions realized by executing a program.

[0081] The sensor control unit 24 acquires a first detection value A1 and a second detection value A2 corresponding to the smoke concentration by reading the signal from the light receiving amplifier unit 38 through A / D conversion synchronized with the timing of the light emission drive of the first light emitting element 30 and the second light emitting element 32, and when the fire detection unit 20 detects a fire based on the acquired first detection value A1 and second detection value A2, it activates the alarm circuit unit 26, short-circuits the positive signal line 14a and the negative signal line 14b to a low impedance, passes a fire alarm current, and transmits a fire alarm signal to the receiver 10.

[0082] (a6. Fire detection section) The fire detection unit 20 provided as fire detection means in the sensor control unit 24 detects a fire when at least one of the acquired first detection value A1 and second detection value A2 satisfies a predetermined fire detection condition. Here, fire detection based on the first detection value A1 will be described as an example, but the same applies to the case where fire detection is based on both the first detection value A1 and the second detection value A2.

[0083] The fire detection conditions of the fire detection unit 20 are arbitrary, but as an example, a fire is detected when the first detection value A1 satisfies a predetermined smoke density threshold condition. Here, the smoke density threshold condition is a condition under which a fire is detected when the first detection value A1 is equal to or greater than a predetermined smoke density threshold Dth0. For example, if the detector 12 is a type 2 sensitivity detector, a fire is detected when the first detection value A1 is equal to or greater than the smoke density threshold Dth0=10 (% / m) corresponding to the type 2 sensitivity.

[0084] A "Class 2 sensitivity detector" refers to a detector with a legally mandated nominal activation concentration K of 10% / m. When tested for activation, the detector activates within 30 seconds when placed in an airflow of 20-40 cm / sec containing smoke at a concentration of (nominal activation concentration K) x 1.5 = 10% / m x 1.5 = 15% / m. Furthermore, when tested for deactivation, the detector fails to activate within 5 minutes when placed in an airflow of 20-40 cm / sec containing smoke at a concentration of (nominal activation concentration K) x 0.5 = 10% / m x 0.5 = 5% / m, for example, in the case of a non-accumulation detector. In addition to such Class 2 sensitivity detectors with K = 10% / m, "Class 1 sensitivity detectors" with a nominal activation concentration K = 5% / m or "Class 3 sensitivity detectors" with a nominal activation sensitivity K = 15% / m are also acceptable.

[0085] Alternatively, as another fire detection condition, a fire may be detected when a predetermined smoke density threshold condition is met and a predetermined accumulation condition is met. For example, if detector 12 is a type 2 sensitivity detector, a fire is detected when the first detection value A1 is equal to or greater than the smoke density threshold Dth0=10 (% / m) corresponding to type 2 sensitivity for a predetermined accumulation time T0, for example, T0=20 seconds or more.

[0086] Such fire detection conditions, for example, the smoke density threshold Dth0 and the accumulation time T0, are initially set, and in this embodiment, the initially set fire detection conditions, for example, the smoke density threshold Dth0 and the accumulation time T0, are characterized in that they are changed based on the type of smoke being detected.

[0087] [b. Identification of the type of detection target and change of fire detection conditions] (b1. Identification unit) The identification unit 18 provided as an identification means in the sensor control unit 24 identifies the type of the detection target or the type of the cause of occurrence of the detection target based on the first detection value A1 and the second detection value A2 acquired from the signal detection unit 16. Accordingly, the fire detection unit 20 changes the fire detection conditions based on the identification result of the identification unit 18.

[0088] Fig. 4 shows an example of the identification of the detection target and the change of the fire detection conditions according to the identification result, and also shows the increase rate of the detection value and the change of the fire detection conditions.

[0089] As shown in Fig. 4, the types of detection targets identified by the identification unit 18 are roughly classified into, for example, fire detection targets and non-fire detection targets. The types of fire detection targets include white smoke and black smoke. The types of causes of white smoke generation include white smoke fire, smoldering fire, combustion of cotton wicks used in fire tests, etc. The causes of black smoke generation include black smoke fire, combustion fire, combustion of kerosene used in fire tests, etc.

[0090] (b2. Identification of white smoke) The identification unit 18 identifies white smoke when the ratio R = A1 / A2 of the first detection value A1 and the second detection value A2 obtained from the signal detection unit 16 is, for example, not less than the first identification threshold value Rth1 = 5 and less than the second identification threshold value Rth2 = 12 (Rth1 ≤ R < Rth2). When white smoke is identified by the identification unit 18, the fire detection unit 20 changes the initially set fire detection conditions so that fire can be detected more easily than before the change. Note that the identification unit 18 may identify the types such as white smoke fire and smoldering fire that are the causes of white smoke generation.

[0091] The initially set fire detection conditions are, for example, a smoke concentration threshold Dth0 = 10 (% / m) and accumulation time T0 = 20 (seconds) corresponding to a detector with type 2 sensitivity, and when white smoke is identified, the initially set threshold Dth0 = 10 (% / m) is changed to a first threshold Dth1 = 7.5 (% / m) which makes it easier to detect a fire than before the change, and the initially set accumulation time T0 = 20 (seconds) is changed to a first accumulation time T1 = 15 (seconds) which makes it easier to detect a fire than before the change.

[0092] Therefore, when white smoke is identified, a fire is detected when at least one of the first detection value A1 and the second detection value A2 obtained from the signal detection unit 16 reaches the changed first threshold value Dth1=7.5(% / m), for example, and a fire can be detected earlier than when the threshold value before the change was Dth0=10(% / / m).

[0093] (b3. Identification of black smoke) The identification unit 18 identifies the smoke as black smoke when the ratio R=A1 / A2 of the first detection value A1 to the second detection value A2 obtained from the signal detection unit 16 is smaller than, for example, a first identification threshold Rth1=5 (R<5). Note that the identification unit 18 may also identify the type of fire, such as a black smoke fire or a combustion fire, which is a cause of black smoke generation.

[0094] When the identification unit 18 identifies black smoke, the fire detection unit 20 changes the initially set threshold value Dth0 = 10 (% / m) and accumulation time T0 = 20 (seconds) to fire detection conditions that are changed in response to the identification of white smoke, such as the first threshold value Dth1 = 7.5 (% / m) and the first accumulation time T1 = 15 (seconds), which make it easier to detect a fire, such as the second threshold value Dth2 = 5.0 (% / m) and the second accumulation time T2 = 10 (seconds).

[0095] Therefore, when black smoke is identified, a fire is detected when at least one of the first detection value A1 and the second detection value A2 obtained from the signal detection unit 16 reaches the changed second threshold value Dth2=5.0 (% / m), for example, and a fire can be detected earlier than the threshold value before the change Dth0=10 (% / m), and furthermore, a fire can be detected earlier than the first threshold value Dth1=7.5 (% / m), which is changed when white smoke is identified.

[0096] (b4. Identification of non-fire detection targets) When the ratio R=A1 / A2 of the first detection value A1 to the second detection value A2 acquired from the signal detection unit 16 is equal to or greater than, for example, a second discrimination threshold Rth2=12 (R≧12), the discrimination unit 18 discriminates the object as a non-fire detection target, including steam (vapor), dust, cigarette smoke, etc. When the discrimination unit 18 discriminates a non-fire detection target such as steam, the fire detection unit 20 changes the initially set threshold Dth0=10 (% / m) and accumulation time T0=20 (seconds) to a third threshold Dth3=15 (% / m) and a third accumulation time T3=30 (seconds), which make it less likely to be detected as a fire.

[0097] Therefore, when a non-fire detection target such as steam is identified, the first detection value A1 and second detection value A2 of the non-fire detection target such as steam obtained from the signal detection unit 16 cannot reach the changed third threshold Dth3 = 15 (% / m), making it possible to reliably prevent non-fire alarms.

[0098] The values ​​of the threshold values ​​Dth1 to Dth3 and the accumulation times T1 to T3 shown in FIG. 4 are examples. Dth3>Dth0>Dth1>Dth2 T3>T0>T1>T2 can be any value that satisfies the following relationship:

[0099] [c. Detection of Increase Rate and Change of Fire Detection Conditions] Next, the detection of the increase rate based on at least one of the first detection value A1 and the second detection value A2 acquired from the signal detection unit 16 and the change of the fire detection condition based on the increase rate will be described in detail.

[0100] (c1. Increase rate detection section) The increase rate detection unit 22 provided as an increase rate detection means in the sensor control unit 24 of the sensor 12 shown in Figure 2 detects at least one of the increase amounts ΔD1 and ΔD2 of the first detection value A1 and the second detection value A2 acquired from the signal detection unit 16 per predetermined unit time, for example, per minute, as a first increase rate α1 [(% / m) / sec] and a second increase rate α2 [(% / m) / sec].

[0101] The first increase rate α1 of the first detection value A1 and the second increase rate α2 of the second detection value A2, which correspond to the smoke density associated with a fire, depend on the smoke diffusion speed (rising speed) according to the scale of the fire. For example, in a fire involving polyurethane or the like that involves black smoke, a large amount of smoke is generated due to the fast combustion speed, and the first increase rate α1 of the first detection value A1 and the second increase rate α2 of the second detection value A2 detected by the signal detection unit 16 become large.

[0102] On the other hand, in a smoldering fire or the like accompanied by white smoke, the amount of smoke generated is small due to the slow combustion rate, and the first increase rate α1 of the first detection value A1 and the second increase rate α2 of the second detection value A2 obtained from the signal detection unit 16 are small. Furthermore, when non-fire detection targets such as smoke or steam associated with cooking or cigarette smoke occur, the first increase rate α1 of the first detection value A1 and the second increase rate α2 of the second detection value A2 obtained from the signal detection unit 16 exhibit increase rates lower than those of a smoldering fire or the like.

[0103] Fig. 5 is a time chart showing the characteristics of temporal changes in smoke density at different linear growth rates over time, taking as an example the smoke density corresponding to the first detection value A1. As shown in Fig. 5, characteristic a has the highest growth rate, representing, for example, an explosive oil fire, while characteristic e represents, for example, a smoldering fire in which a futon or other object smolders, with characteristics b to d representing fires of a scale between these two. Characteristic f represents the occurrence of non-fire detection targets, such as smoke or steam from cooking or cigarette smoke. Note that the growth rate of smoke density in an actual fire is not linear (constant growth rate), and as is well known, the growth rate changes randomly over time.

[0104] (c2. Changing the fire detection conditions based on the rate of increase) When the increase rate detection unit 22 detects that at least one of the first increase rate α1 of the first detection value A1 and the second increase rate α2 of the second detection value A2 satisfies a predetermined increase rate threshold condition, for example, when the increase rate is equal to or greater than a predetermined increase rate threshold αth, the fire detection unit 20 changes the fire detection conditions to make it easier to detect a fire than before the change and detects a fire.

[0105] Here, the increase rate threshold αth of the smoke concentration increase rate α for changing the fire detection conditions is arbitrary, but for example, in Figure 5, the increase rate of characteristic g, which is approximately halfway between characteristic e due to smoldering fire, which has the lowest increase rate among the fire detection targets, and characteristic f due to smoldering fire, is set as the increase rate threshold αth.

[0106] The fire detection unit 20 changes the fire detection conditions based on the discrimination result between white smoke and black smoke discriminated by the discrimination unit 18 and the increase rate detected by the increase rate detection unit 22, and the degree to which the fire detection conditions are changed based on the increase rate differs between when white smoke is discriminated and when black smoke is discriminated.

[0107] When white smoke is identified by the identification unit 18, the fire detection unit 20 changes the fire detection conditions based on the detection of the increase rate so that a fire is more likely to be detected than the fire detection conditions changed when white smoke is identified. For example, as shown in Fig. 4, when white smoke is identified and the increase rate (at least one of α1 and α2) is equal to or greater than a predetermined increase rate threshold αth, the fire detection conditions before the change, which were initially set to a threshold Dth0 of 10 (% / m) and an accumulation time T0 of 20 (seconds), are changed to a fourth threshold Dth4 of 5.0 (% / m) and a fourth accumulation time T4 of 10 (seconds), which are fire detection conditions that make it easier to detect a fire.

[0108] The fire detection conditions changed based on this increase rate are conditions that make it even easier to detect a fire than the fire detection conditions changed to identify white smoke, which were the first threshold Dth1 = 7.5 (% / m) and the first accumulation time T1 = 15 (seconds).

[0109] Furthermore, when the identification unit 18 identifies black smoke, the fire detection unit 20 changes the fire detection conditions based on the detection of the increase rate so that a fire is more likely to be detected than the fire detection conditions changed when black smoke is identified. For example, as shown in Fig. 4, when black smoke is identified and the increase rate (at least one of α1 and α2) is equal to or greater than a predetermined increase rate threshold αth, the fire detection conditions before the change, which were initially set to a threshold Dth0 of 10 (% / m) and an initial accumulation time T0 of 20 (seconds), are changed to fire detection conditions of a fifth threshold Dth5 of 2.5 (% / m) and a fifth accumulation time T5 of 5 (seconds), so that a fire is more likely to be detected.

[0110] The fire detection conditions changed based on this increase rate are conditions that make it easier to detect a fire than the fire detection conditions changed to identify black smoke, which are the second threshold Dth2 = 5.0 (% / m) and the second accumulation time T2 = 10 (seconds).

[0111] The values ​​of the threshold values ​​Dth1 to Dth5 and the accumulation times T1 to T5 shown in FIG. 4 are examples. Dth3>Dth0>Dth1>Dth2 Dth1>Dth4 Dth2>Dth5 T3>T0>T1>T25 T1>T4 T2>T5 can be any value that satisfies the following relationship:

[0112] [d. Sensor control operation] FIG. 6 is a flow chart showing the control operation according to the embodiment of the sensor of FIG. 2, which is the control operation of the sensor control unit 24.

[0113] As shown in Fig. 6, in step S1, the sensor control unit 24 obtains a first detection value A1 and a second detection value A2 corresponding to the smoke concentration from the first signal and the second signal detected by the signal detection unit 16. Taking the smoke detection unit 31 in Fig. 3(A) as an example, the light-emitting drive unit 36 ​​sequentially drives the first light-emitting element 30 and the second light-emitting element 32 to emit light at predetermined intervals, and the light-receiving element 34 receives scattered light of different wavelengths and scattering angles from smoke, steam, etc. The first and second signals amplified by the light-receiving amplifier unit 38 are read in by A / D conversion in synchronization with each light emission to obtain the first detection value A1 and the second detection value A2 corresponding to the smoke concentration.

[0114] Next, in step S2, the ratio R = A1 / A2 of the first detection value A1 and the second detection value A2 obtained is calculated, and in step S3, at least one of the first increase rate α1 of the first detection value A1 and the second increase rate α2 of the second detection value A2 is detected. Next, in step S4, if the ratio R is equal to or greater than the first discrimination threshold Rth1 = 5 and less than the second discrimination threshold Rth2 = 12, it is identified as white smoke, and the process proceeds to step S5. In step S5, if the increase rate detected in step S3 is less than the increase rate threshold αth, the process proceeds to step S6, where the initially set fire detection conditions of threshold Dth0 = 10 (% / m) and accumulation time T0 = 20 (seconds) are changed to first threshold Dth1 = 7.5 (% / m) and first accumulation time T1 = 15 (seconds), which are fire detection conditions based on the white smoke identified in step S4, to make it easier to detect a fire, and the process proceeds to step S14.

[0115] In step S14, if at least one of the first detection value A1 and the second detection value A2 acquired in step S1 satisfies the changed fire detection condition, a fire is detected and the process proceeds to step S15, instructing the alarm circuit unit 26 to send a fire alarm signal, activating the alarm circuit unit 26 and transmitting the fire alarm signal to the receiver 10. Next, in step S16, recovery is determined from the interruption of the power supply to the signal line 14 due to a recovery operation in the receiver 10, and the process returns to the initial detector control in step S1.

[0116] On the other hand, in step S5, if the increase rate detected in step S3 is equal to or greater than the predetermined increase rate threshold αth, the process proceeds to step S7, where the pre-change fire detection conditions, which were the initially set threshold Dth0 = 10 (% / m) and accumulation time T0 = 20 (seconds), are changed to a fourth threshold Dth4 = 5.0 (% / m) and a fourth accumulation time T4 = 10 (seconds) to make it easier to detect a fire, and the process proceeds to step S14, where the process of detecting a fire is performed.

[0117] Furthermore, if white smoke is not identified in step S4, the process proceeds to step S8, and if the ratio R is smaller than the first identification threshold Rth1=5, black smoke is identified and the process proceeds to step S9. If in step S9 the increase rate detected in step S3 is smaller than the increase rate threshold αth, the process proceeds to step S10, where the initial threshold Dth0=10 (% / m) and accumulation time T0=20 (seconds), which are the fire detection conditions before the change, are changed to second threshold Dth2=5.0 (% / m) and second accumulation time T2=10 (seconds), which are fire detection conditions based on the black smoke identified in step S8, so that a fire is more likely to be detected, and the process proceeds to step S14 to perform processing to detect a fire.

[0118] On the other hand, if the increase rate detected in step S3 is equal to or greater than the predetermined increase rate threshold αth in step S9, the process proceeds to step S11, where the pre-change fire detection conditions, which were the initially set threshold Dth0 = 10 (% / m) and accumulation time T0 = 20 (seconds), are changed to a fifth threshold Dth5 = 2.5 (% / m) and a fifth accumulation time T5 = 5 (seconds), making it easier to detect a fire, and the process proceeds to step S14 to perform the fire detection process.

[0119] Furthermore, if black smoke is not identified in step S8, the process proceeds to step S12, and if the ratio R is equal to or greater than the second identification threshold Rth2=12, it is identified as a non-fire detection target such as steam, and the process proceeds to step S13, where the pre-change fire detection conditions, which were the initial threshold Dth0=10 (% / m) and accumulation time T0=20 (seconds), are changed to a third threshold Dth3=15 (% / m) and a third accumulation time T3=30 (seconds), making it less likely to be detected as a fire, and the process proceeds to step S14 to perform the fire detection process.

[0120] Furthermore, if a non-fire detection target such as steam is not identified in step S12, the process proceeds to step S14 to perform fire detection processing while maintaining the initially set fire detection conditions of threshold Dth0 = 10 (% / m) and accumulation time T0 = 20 (seconds).

[0121] [e. Other basic concepts of the embodiment] FIG. 7 is an explanatory diagram showing another basic concept of an embodiment corresponding to the second disaster prevention equipment, and is a fire alarm equipment as an example of the second disaster prevention equipment equipped with a receiver 10 and a detector 12. The detector 12 is provided with a signal detection unit 16 that functions as a signal detection means of the fire detection device, and the receiver 10 is provided with an identification unit 18 that functions as an identification means of the fire detection device and a fire detection unit 20 that functions as a fire detection means, and further the receiver 10 is provided with an increase rate detection unit 22 that functions as an increase rate detection means.

[0122] The signal detection unit 16 provided in the detector 12 and the identification unit 18, fire detection unit 20 and increase rate detection unit 22 provided in the receiver 10 are basically the same as the signal detection unit 16, identification unit 18, fire detection unit 20 and increase rate detection unit 22 provided in the detector 12 in Figure 1, but differ in that the first detection value A1 and the second detection value A2 obtained from the first signal and the second signal detected by the signal detection unit 16 of the detector 12 are transmitted to the receiver 10 via the transmission line 114, and the receiver 10 performs the following operations: identify the type of detection object, detect a fire when the fire detection conditions are met, change the fire detection conditions based on the identification result of the detection object, and change the fire detection conditions based on the increase rate.

[0123] Next, the specific content of the embodiment corresponding to FIG. 7 will be described in more detail.

[0124] [fR-type disaster prevention equipment] Fig. 8 is an explanatory diagram of an R-type (Record-type) disaster prevention system showing specific details of an embodiment corresponding to Fig. 7. Here, the "R-type disaster prevention system" is a system that monitors fires for each detector 12 (for each detector) by transmitting between a receiver 10 and a detector 12.

[0125] As shown in Fig. 8, the R-type disaster prevention equipment of this embodiment includes a receiver 10 and sensors 12, with multiple sensors 12 connected to a transmission line 114 drawn from the receiver 10 to a monitored area such as a room in a building. The transmission line 114 drawn from the receiver 10 includes a positive transmission line 114a and a negative transmission line (common transmission line) 114b, and supplies power from the receiver 10 to the sensors 12 and transmits and receives signals between the receiver 10 and the sensors 12 using a predetermined transmission method. A dedicated power supply line may also be provided.

[0126] (f1.sensor) 2, the detector 12 comprises a signal detection section 16 having a smoke detection structure, for example, as shown in Fig. 3(A), a detector control section 24, a power supply section 28, a light emission drive section 36, and a light reception amplifier section 38, but differs in that a transmission section 60 is provided to transmit and receive signals to and from the receiver 10 using a predetermined transmission method. Also, the detector control section 24 does not have the functions of the identification section 18, fire detection section 20, and increase rate detection section 22, which are components of the fire detection device of the present invention shown in Fig. 2, and these functions are provided on the receiver 10 side.

[0127] (f2. Receiver) 2, the receiver 10 comprises a receiver control unit 40, a display unit 44, an operation unit 46, an alarm unit 48, and a reporting unit 50, but differs in that a transmission unit 62 is provided to send and receive signals to and from the detector 12 using a predetermined transmission method, and in that the receiver control unit 40 is provided with the functions of an identification unit 18, a fire detection unit 20, and an increase rate detection unit 22, which are components of the fire detection device of the present invention, as functions realized by executing a program. The identification unit 18, fire detection unit 20, and increase rate detection unit 22 provided in the receiver 10 are basically the same as when provided in the detector 12 in the embodiment of FIG. 2.

[0128] (f3. Transmission Control) In the R-type disaster prevention equipment, a unique address is assigned to the detectors 12, and the receiver 10 transmits a batch A / D conversion command signal at a predetermined cycle, for example, every minute. All detectors 12 that receive the batch A / D conversion command signal A / D convert and hold (store) the first detection value A1 and the second detection value A2 corresponding to the first signal and the second signal obtained by receiving scattered light of different wavelengths and different scattering angles in their signal detection units 16. Next, the receiver 10 transmits a call signal sequentially specifying the detector addresses, thereby performing polling to have each detector 12 return a response signal including the first detection value A1 and the second detection value A2.

[0129] When the first detection value A1 or the second detection value A2 corresponding to the smoke concentration reaches a predetermined fire warning level (preliminary fire detection level), for example, 1 (% / m), the detector 12 detects a fire warning and transmits a fire interrupt signal to the receiver 10.

[0130] When the receiver 10 receives a fire interrupt signal from a detector 12, it transmits a group search command signal specifying a group address, performs a group search to identify the group address to which the detector 12 that responded with the fire interrupt signal belongs, and then transmits an intra-group search command signal specifying the detector addresses within the searched group address in sequence, and identifies the addresses of the detectors 12 that responded with the fire interrupt signal, i.e., the addresses of the detectors 12 that detected a fire precursor.

[0131] Next, the receiver 10 transmits an A / D conversion command signal and a call signal specifying the address of the detector 12 that has detected a fire precursor at a predetermined cycle that is shorter than normal, and intensively acquires the first detection value A1 and the second detection value A2 from the detector 12 that has detected a fire precursor, and performs control to detect a fire using the identification unit 18, fire detection unit 20, and increase rate detection unit 22 provided in the receiver control unit 40. Note that the transmission control between the receiver 10 and the detector 12 is one example, and any known transmission control can be applied.

[0132] (f4.R-type disaster prevention equipment control operation) FIG. 9 is a flowchart showing the control operation of the embodiment of the R-type disaster prevention equipment of FIG. 8 in the form of a time chart.

[0133] 9, in step S21, the receiver 10 performs a fire monitoring transmission process by transmitting a batch A / D conversion command signal at a predetermined cycle, for example, at one-minute cycles, then transmitting a call signal specifying the detector address, and receiving a response signal from the detector 12. Meanwhile, in step S22, the detector 12 performs a fire monitoring response process by receiving the batch A / D conversion command signal from the receiver 10, storing and holding the first detection value A1 and second detection value A2 obtained at that time, and then transmitting a response signal including the first detection value A1 and second detection value A2 when it receives a call signal specifying its own address.

[0134] Next, when the detector 12 determines in step S23 that the smoke density of the acquired first detection value A1 or second detection value A2 has reached a predetermined fire precursor level, for example, 1 (% / m), the process proceeds to step S24, where it transmits a fire interrupt signal to the receiver 10 as a fire precursor transmission process. In step S25, the receiver 10 searches for and identifies the address of the detector that transmitted the fire interrupt signal based on the fire interrupt signal received from the detector 12 as a fire precursor reception process.

[0135] In step S26, the receiver 10 determines whether or not a fire interruption signal has been received from the detector 12, and if no fire interruption signal has been received, the receiver 10 returns to step S21; if a fire interruption signal has been received, the receiver 10 proceeds to the following step S27; on the other hand, if a fire interruption signal has been transmitted, the receiver 10 proceeds to step S27.

[0136] In step S27, the receiver 10 repeatedly transmits a batch A / D conversion command signal and a call signal specifying the address of the detector 12 that transmitted the fire interrupt signal at short intervals as a process for receiving the detection values ​​A1 and A2, and causes the detector 12 to perform a process for transmitting the detection values ​​A1 and A2 in step S28, thereby intensively receiving the first detection value A1 and the second detection value A2 from the detector 12 that has detected a fire precursor.

[0137] Next, the receiver 10 proceeds to step S29, where it calculates the ratio R=A1 / A2 based on the acquired first detection value A1 and second detection value A2, and detects the increase rate of at least one of the first detection value A1 and the second detection value A2 using the increase rate detection unit 22. Next, in step S30, the identification unit 18 identifies the type of detection target, such as white smoke, black smoke, or steam, based on the ratio R, and changes the fire detection conditions based on the identification result. The changes in the fire detection conditions are, for example, the same as those shown in the list in FIG. 4.

[0138] Next, the receiver 10 proceeds to step S31 and changes the fire detection conditions based on the detected increase rate. This change in fire detection conditions based on the increase rate is, for example, the same as the list shown in Figure 4. Next, the receiver 10 proceeds to step S32, and if it determines that at least one of the first detection value A1 and the second detection value A2 satisfies the initially set fire detection conditions or the changed fire detection conditions, it detects a fire and proceeds to step S33, where it performs fire alarm processing including sounding the main acoustic alarm and district acoustic alarm, displaying the location of the fire based on the address of the detector that detected the fire, and interlocking control of smoke control equipment.

[0139] Next, if the receiver 10 determines in step S34 that the restoration is due to a restoration operation following the extinguishing of the fire, it transmits a restoration signal to the detector 12 in step S35 and returns to the fire monitoring transmission processing in step S21. Also, if the detector 12 determines in step S36 that it has received a restoration signal, it returns to the fire monitoring response processing in step S22.

[0140] [g. Modifications of the present invention] An alternative embodiment of the present invention will now be described in more detail.

[0141] (Fire detection equipment) The fire detection device of the above embodiment is exemplified as having a signal detection unit 16, an identification unit 18, a fire detection unit 20, and an amplification factor detection unit 22, but is not limited to this and includes a fire detection device whose basic configuration is the signal detection unit 16, the identification unit 18, and the fire detection unit 20 excluding the amplification factor detection unit 22.

[0142] (fire alarm) Although the above embodiment has been described as an example of a fire detection device for disaster prevention equipment equipped with a receiver and a sensor, a residential fire alarm, for example, equipped with a means for detecting a fire from smoke density and a means for issuing an alarm about the fire, may also be configured as a fire detection device. In the case of a fire alarm, the fire alarm will be provided with the functions of a signal detection unit 16, a discrimination unit 18, a fire detection unit 20, and an increase rate detection unit 22 that constitute a fire detection device, similar to the sensor 12 of the disaster prevention equipment shown in Figures 1 and 2.

[0143] (Fire detection conditions) In the fire detection device of the above embodiment, the fire detection unit 20 changes the fire detection conditions in accordance with the identification result by the identification unit 18, but this is not limited to this, and for example, the identification unit 18 may change the fire detection conditions in accordance with the identification result, and the fire detection unit 20 may detect a fire under the changed fire detection conditions. The same applies when the fire detection conditions are changed based on the increase rate detected by the increase rate detection unit 22.

[0144] (others) Furthermore, the present invention includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited to the numerical values ​​shown in the above embodiments. [Explanation of symbols]

[0145] 10: Receiver 12: Sensor 14: Signal line 16: Signal detection unit 18: Identification unit 20: Fire detection unit 22: Increase rate detection unit 24: Sensor control unit 26: Alarm circuit section 28: Power supply section 30: First light-emitting element 32: Second light-emitting element 34: Light receiving element 34(34-1): First light receiving element 34(34-2): Second light receiving element 35: Light-emitting element 36: Light emitting drive unit 38: Photoreceiving amplifier 40: Receiver control unit 42: Line receiving unit 44: Display section 46:Operation unit 48:Alarm section 50:Transfer Department 60, 62: Transmission section 114: Transmission line

Claims

1. A signal detection means for detecting signals associated with optical actions of a detection target in a monitoring area by a plurality of optical settings, the signal detection means detecting a plurality of signals obtained by the plurality of optical settings; a discrimination means for discriminating between a fire detection target and a non-fire detection target as the type of the detection target based on the plurality of signals detected by the signal detection means, and for discriminating between white smoke and black smoke as the type of the fire detection target; a fire detection means for detecting a fire when a predetermined fire detection condition is satisfied based on at least one of the plurality of signals detected by the signal detection means; Equipped with The fire detection condition is: When the discrimination means discriminates the white smoke as the fire detection target, the fire detection conditions are changed so that the fire detection conditions are more likely to be detected as a fire than the initially set fire detection conditions of the fire detection means, When the discrimination means discriminates the black smoke as the fire detection target, the fire detection means changes the fire detection conditions so that the black smoke is more likely to be detected as a fire than the fire detection conditions after the change associated with the discrimination of the white smoke, A fire detection device characterized in that, when the identification means identifies a non-fire detection target, the fire detection conditions initially set in the fire detection means are changed to make it less likely to be detected as a fire.

2. 2. The fire detection device according to claim 1, an increase rate detection means for detecting an increase rate of at least one of the plurality of signals; The fire detection device is characterized in that the fire detection conditions are changed based on the identification result by the identification means and the increase rate by the increase rate detection means.

3. A signal detection means for detecting signals associated with optical actions of a detection target in a monitoring area by a plurality of optical settings, the signal detection means detecting a plurality of signals obtained by the plurality of optical settings; a discrimination means for discriminating between a fire detection target and a non-fire detection target as the type of the detection target based on the plurality of signals detected by the signal detection means, and for discriminating between white smoke and black smoke as the type of the fire detection target; a fire detection means for detecting a fire when a predetermined fire detection condition is satisfied based on at least one of the plurality of signals detected by the signal detection means; Equipped with The fire detection condition is: When the discrimination means discriminates the white smoke as the fire detection target, the fire detection conditions are changed so that the fire detection conditions are more likely to be detected as a fire than the initially set fire detection conditions of the fire detection means, When the discrimination means discriminates the black smoke as the fire detection target, the fire detection means changes the fire detection conditions so that the black smoke is more likely to be detected as a fire than the fire detection conditions after the change associated with the discrimination of the white smoke, This disaster prevention equipment is characterized in that, when the identification means identifies a non-fire detection target, the fire detection conditions are changed so that the non-fire detection target is less likely to be detected as a fire than the fire detection conditions initially set in the fire detection means.

4. The disaster prevention equipment according to claim 3, an increase rate detection means for detecting an increase rate of at least one of the plurality of signals; The fire detection condition is changed based on the identification result by the identification means and the increase rate detected by the increase rate detection means.

5. The disaster prevention equipment according to claim 4, a receiver and a detector that detects a fire and transmits a fire signal to the receiver; The detector is characterized in that it is equipped with the signal detection means, the identification means, and the fire detection means, or the signal detection means, the identification means, the fire detection means, and the increase rate detection means.

6. The disaster prevention equipment according to claim 4, a receiver and a detector that detects a fire and transmits a fire signal to the receiver; The sensor comprises the signal detection means, The disaster prevention equipment is characterized in that the receiver is equipped with the identification means and the fire detection means, or the identification means, the fire detection means and the increase rate detection means.

7. 1. A fire detection method for detecting a fire in a monitored area, comprising: a signal detection means for detecting a signal associated with an optical action of a detection target in the monitoring area by at least a first optical setting and a second optical setting, and detecting a first signal obtained by the first optical setting and a second signal obtained by the second optical setting; an identification means for identifying the types of detection targets as fire detection targets and non-fire detection targets based on the plurality of signals detected by the signal detection means, and for identifying the types of fire detection targets as white smoke and black smoke; a fire detection means for detecting a fire when a predetermined fire detection condition is satisfied based on at least one of the plurality of signals detected by the signal detection means; The fire detection condition is When the discrimination means discriminates the white smoke as the fire detection target, the fire detection means changes the fire detection conditions so that the fire detection conditions are more likely to be detected as a fire than the initially set fire detection conditions, When the discrimination means discriminates the black smoke as the fire detection target, the fire detection means changes the fire detection conditions so that the black smoke is more likely to be detected as a fire than the fire detection conditions after the change associated with the discrimination of the white smoke, A fire detection method characterized in that, when the identification means identifies a non-fire detection target, the fire detection conditions initially set in the fire detection means are changed so that the non-fire detection target is less likely to be detected as a fire.

8. 8. The fire detection method according to claim 7, an increase rate detection means for detecting an increase rate of at least one of the first signal and the second signal; A fire detection method, characterized in that the fire detection conditions are changed based on the identification result by the identification means and the increase rate by the increase rate detection means.

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