JP2023148602A - Smoke sensor - Google Patents

Abstract

To provide a smoke sensor capable of appropriately determining whether or not a concentration of smoke exceeds a predetermined threshold regardless of whether or not sounding means such as a speaker is operating.SOLUTION: A smoke sensor 100 comprises: smoke sensing means 2 for detecting smoke; sounding means 3 which generates sound during operation; sounding determination means 4 for determining whether or not the sounding means 3 is operating; and control means 1 for controlling a warning operation by determining whether or not a smoke concentration exceeds a threshold based on a predetermined determination method. The control means 1 detects the concentration from smoke detected by the smoke sensing means 2, changes the determination method of the smoke concentration depending on whether the sounding means 3 is operating or not based on a determination result of the sounding determination means 4, and determines whether one or more of detected concentrations, detected within a predetermined period, exceed a predetermined threshold in the case where the sounding means 3 is operating.SELECTED DRAWING: Figure 1

Description

FIELD OF THE INVENTION The present invention relates to smoke detectors.

2. Description of the Related Art Smoke detectors have been used in the past to monitor the concentration of smoke indoors, such as in houses, and to notify users when the concentration exceeds a certain level to urge them to take action or evacuate. Smoke detectors are also used in various alarm devices such as fire alarms as a means of determining the occurrence of abnormal conditions such as fire, and are also a complex alarm system that also includes means for detecting toxic gases such as carbon monoxide. It is also used in utensils. In such smoke detectors, smoke that flows into the housing from the inlet provided on the side is introduced into the smoke detection space between the light emitting part and the light receiving part, and the introduced smoke causes the light to emit light. Light traveling from the sensor through the detection space to the light receiving section is scattered, and the light receiving section detects the scattered light according to the concentration of smoke, thereby detecting the concentration of smoke (see, for example, Patent Document 1).

Patent No. 7001397

Various types of alarms, such as individual smoke detectors or fire alarms that include smoke detectors, are often equipped with a sound system to notify the user of the occurrence of a detected abnormal situation such as a fire or gas leak. , a means of pronunciation is provided. For example, speakers can emit not only monotonous warning sounds but also sounds that include information such as specific abnormal situations and countermeasures. Alarm devices equipped with

However, with alarms that include smoke detectors and are equipped with sounding means such as speakers, the introduction of smoke from the outside of the alarm to the detection space may be inhibited by vibrations in the air caused by the operation of the speakers. be. In particular, in order to meet the demand for miniaturization of alarm devices, if the sounding means such as a speaker and the smoke introduction path from the smoke inlet to the detection space are placed close to each other, the spatial It is thought that it will become difficult to separate smoke, and the influence of the operation of speakers etc. on the introduction of smoke will increase. If the proper introduction of smoke is obstructed, alarms based on smoke concentration, such as fire alarms, will be issued immediately, even if the area around the alarm is filled with smoke at a concentration that is judged to be abnormal. It may also mean that they are not emitted.

In view of such problems, the present invention provides a smoke sensor that can appropriately determine whether the concentration of smoke exceeds a predetermined threshold regardless of whether or not an internal sound generating means such as a speaker is operating. The purpose is to provide equipment.

The smoke detector of the present invention includes a smoke sensing means for detecting smoke, a sounding means for emitting a sound when activated, a sounding determination means for determining whether the sounding means is activated, and a smoke detector that detects smoke when the smoke concentration exceeds a threshold value. control means for controlling alarm operation by determining based on a predetermined determination method whether or not the smoke is detected by the smoke sensing means; Based on the determination result, the determination method is changed depending on whether the sounding means is operating or not, and if the sounding means is operating, it is detected within a predetermined period of time. It is determined whether any one or more of the detected concentrations exceeds the threshold value.

The control means may determine whether the detected concentration exceeds the threshold value at a predetermined timing when the sound generation means is not operating.

The control means determines that the smoke concentration exceeds the threshold value when the detected concentration detected at the predetermined timing exceeds the threshold value a predetermined number of times when the sound generation means is not operating. Good too.

The control means determines that the smoke concentration exceeds the threshold when any one or more of the detected concentrations detected within one predetermined period exceeds the threshold when the sound generation means is operating. It is determined that the smoke concentration exceeds the threshold when the detected concentration detected at the predetermined timing exceeds the threshold several times in a row. Good too.

The control means detects the concentration from the smoke detected by the smoke sensing means at regular intervals when the sounding means is not operating, and detects the concentration from the smoke detected by the smoke sensing means when the sounding means is operating. The concentration may be detected from the detected smoke at a cycle shorter than the fixed cycle.

The smoke detector of the present invention may further include a CO detection means for detecting carbon monoxide concentration, and the control means determines whether the carbon monoxide concentration exceeds a threshold value based on a predetermined determination method. Even if the method for determining whether the carbon monoxide concentration exceeds the threshold value is the same when the sounding means is operating and when the sounding means is not operating, good.

The smoke detector of the present invention may further include a storage means for storing all or the maximum value of the detected concentrations detected within the predetermined period.

The smoke detector of the present invention may further include storage means for storing information regarding whether or not the sound generation means is operating.

According to the present invention, there is provided a smoke detector that can appropriately determine whether the concentration of smoke exceeds a predetermined threshold regardless of whether or not an internal sound generating means such as a speaker is operating. Ru.

FIG. 1 is a block diagram showing an example of the configuration of a smoke detector according to an embodiment of the present invention. FIG. 1 is a perspective view showing an example of an alarm device including a smoke detector according to an embodiment of the present invention. FIG. 3 is a schematic diagram showing the state of gas flow within the casing of the alarm device of FIG. 2. FIG. FIG. 4 is a timing chart showing an example of density determination when no sound is generated in an embodiment of the present invention. FIG. 6 is a timing chart showing an example of density determination while smoke density is rising during sound generation in an embodiment of the present invention. FIG. 6 is a timing chart showing an example of density determination during a fall in smoke density during sound generation in an embodiment of the present invention. It is a flowchart which shows an example of the operation|movement of the smoke detector of one embodiment of this invention at the time of non-sounding. It is a flowchart which shows an example of the operation|movement at the time of sound of the smoke detector of one embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A smoke detector according to an embodiment of the present invention will be described below with reference to the accompanying drawings. However, the embodiments described below and the accompanying drawings merely show an example of the smoke detector according to the present invention. The configuration and operation of the smoke detector according to the present invention are not limited to the configuration and operation illustrated in the embodiments described below and the accompanying drawings.

<Basic configuration>
FIG. 1 shows a block diagram of the main components of a smoke detector 100 according to an embodiment of the present invention. The smoke detector 100 monitors the environment around the installation location of the smoke detector 100, such as indoors of a residence or various buildings, and turns on the light when it is determined that the concentration of surrounding smoke is equal to or higher than a predetermined threshold. It performs an alarm operation to notify the user by sound or sound.

As shown in FIG. 1, the smoke detector 100 of the present embodiment includes a smoke sensing means 2 for detecting smoke, a sounding means 3 for emitting a sound when activated, and a determination as to whether or not the sounding means 3 is operating. and a control means 1 that controls the alarm operation. The smoke detector 100 in the example of FIG. 1 further includes a storage means 5 and a CO detection means 6 for detecting carbon monoxide concentration. The smoke detector 100 has a housing 101, and the housing 101 is equipped with a smoke sensing means 2, a sounding means 3, a sounding determining means 4, a control means 1, a storage means 5, and a CO detection means 6. ing. The storage means 5 stores various information generated and/or used in a series of alarm operations by the smoke detector 100, such as the concentration of detected smoke. In the example of FIG. 1, the control means 1 is connected to all the others, namely the smoke detection means 2, the sound generation means 3, the sound generation determination means 4, the storage means 5, and the CO detection means 6. Therefore, the control means 1 may be able to control all of these other means. Further, the control means 1 may be able to exchange information possessed by each means and signals generated by each means with all of these other means. In the example of FIG. 1, the smoke sensing means 2 and the storage means 5 are also connected to each other. In addition, the pronunciation determining means 4 and the sounding means 3 are connected via a medium such as a sound wave, which is a vibration of gas, which conveys that the sounding means 3 is emitting sound, as shown by the dashed arrow. may have been done.

The control means 1 detects the concentration of smoke detected by the smoke sensing means 2. That is, the control means 1 detects the concentration of smoke in the gas actually surrounding the smoke sensing means 2 in the vicinity of the smoke sensing means 2. In addition, the control means 1 determines whether the smoke concentration in the installation environment of the smoke detector 100 exceeds a threshold value based on a predetermined determination method (hereinafter, this determination method is also simply referred to as a "concentration determination method"). is configured to make a determination. In the following, in order to make the distinction clear using concise terms, the smoke concentration of the installation environment of the smoke detector 100 to be monitored by the smoke detector 100 is also simply referred to as "ambient concentration", The concentration of smoke actually detected by the control means 1 from the smoke detected by is also simply referred to as "detected concentration."

In this embodiment, the control means 1 determines whether or not the sound generation means 3 is operating based on the judgment result of the pronunciation judgment means 4, and determines whether the sound generation means 3 is operating or not. The concentration determination method described above is changed depending on whether or not it is present. Then, when the sound generation means 3 is operating, the control means 1 determines whether any one or more of the one or more detected concentrations detected by the control means 1 within a predetermined period exceeds a predetermined threshold value. It is configured as follows. In this embodiment, when the sounding means 3 is operating, the control means 1 controls whether at least one of the detected concentrations detected from the smoke detected by the smoke sensing means 2 within a predetermined period is It is determined whether a predetermined threshold value is exceeded. Therefore, as will be described in detail below, even in a situation where smoke is difficult to reach the detectable area of the smoke sensing means 2 due to the operation of the sounding means 3, it is possible to determine whether the ambient concentration exceeds a predetermined threshold value. It may be possible to make an appropriate judgment and promptly inform the user.

<Basic operation of each component and smoke detector>
The smoke sensing means 2 detects smoke in the space around the smoke sensing means 2, specifically, smoke in a smoke sensing area within the smoke sensing means 2 that communicates with the surroundings, and detects the amount of smoke, that is, within the smoke sensing area. Outputs sensing results using electrical signals (voltage and current) whose size corresponds to the concentration of smoke. Therefore, the smoke sensing means 2 outputs a sensing result according to the concentration of smoke that has flowed from around the smoke sensor 100 into the smoke sensing area of the smoke sensing means 2 together with the surrounding air. Another example of the smoke sensing means 2 is a photoelectric spot sensing mechanism, but the smoke sensing means 2 is not limited thereto.

For example, a photoelectric spot-type sensing mechanism is equipped with a light-emitting element that emits light toward a smoke-sensing area, and a light-receiving element that receives light propagating within the smoke-sensing area is shifted from the optical axis of the light from the light-emitting element. A light shielding wall is provided between the light emitting element and the light emitting element. When smoke is present within the smoke sensing area, light from the light emitting element is scattered to an extent that depends on the concentration of smoke within the smoke sensing area, and the scattered light is received by the light receiving element. The light-receiving element outputs an output signal (sensing signal) such as a voltage or current having a magnitude corresponding to the amount of scattered light received, that is, according to the density of smoke. In the photoelectric separation type sensing mechanism, a light emitting element and a light receiving element are provided to face each other on the optical axis, similar to the photoelectric spot type, and the smoke is weakened by the smoke in the smoke sensing area to an extent corresponding to its concentration. Light is received by a light receiving element. Based on the received light, the light receiving element outputs a sensing signal having a magnitude corresponding to the density of smoke.

As shown in FIG. 1, the smoke sensing means 2 is connected to the control means 1, and the output of the smoke sensing means 2 is input to the control means 1. Information obtained from the output results of the smoke sensing means 2 that are input to the control means 1 may be stored in the storage means 5. In the example of FIG. 1, the smoke sensing means 2 and the storage means 5 are connected, so the sensing result of the smoke sensing means 2 may be sent directly from the smoke sensing means 2 to the storage means 5.

The sound generating means 3 may be any element capable of emitting sound according to control information such as an electrical signal from outside the sound generating means 3. Examples of the sound generation means 3 include a speaker capable of emitting a sound of any frequency and volume, a buzzer that emits a monotonous continuous sound or an intermittent sound, but the sound generation means 3 is not limited to these. The sound generating means 3 emits sound by vibrating surrounding gas such as air when in operation. In other words, the sound generating means 3 can emit any sound by making a sound during operation. The sounding means 3 can emit an alarm sound when the smoke detector 100 issues an alarm regarding the detection of smoke. For example, when the sounding means 3 is a speaker, the sounding means 3 may emit a warning sound as well as a message urging appropriate measures such as evacuation and ventilation. Further, the sounding means 3 may emit an alarm sound for any alarm other than the alarm when smoke is detected, such as an alarm sound when carbon monoxide gas is detected or a message urging ventilation, and may emit an alarm sound for any alarm other than the alarm when smoke is detected. You can also emit any notification sound or notification message below. For example, when a fire is detected based on the detection of smoke at a predetermined concentration or higher, and/or when an abnormal condition is detected based on the temperature and humidity of the surrounding environment such as flammable gas at a predetermined concentration or higher or excessively high temperature or low humidity, and when the remaining battery level is detected. The sound generating means 3 may emit a sound or voice suitable for each state, such as when notifying the user or the self-inspection results. The operation of the sounding means 3 may be controlled by the control means 1 or by any component of the smoke detector 100 other than the control means 1.

As described above, the control means 1 detects the concentration (detected concentration) of smoke detected by the smoke sensing means 2 and controls the alarm operation. For example, the control means 1 has a calibration curve between the sensing signal output from the smoke sensing means 2 and the smoke concentration, and uses the calibration curve to perform detection based on the signal currently input from the smoke sensing means 2. Detect concentration. Furthermore, it is determined whether the detected concentration exceeds a predetermined threshold value. Then, based on the determination result regarding the detected concentration and the concentration determination method, it is determined whether the ambient concentration exceeds a predetermined threshold value.

The control means 1 may be configured to not only determine the ambient concentration but also control the entire alarm operation in the smoke detector 100. For example, the control means 1 may control the sensing operation of the smoke sensing means 2, such as the intensity and emission timing of the light for smoke detection, and the output timing of the sensing signal, and the operation of the sounding means 3, for example, The timing of the sound, its volume, frequency, duration of sound, and the content of the message to be emitted may be controlled. Further, the control means 1 may control the storage means 5, for example, the operation of writing and reading various information to the storage means. For example, the control means 1 may select information to be written to the storage means 5 or information to be read from the storage means 5, or a storage space (address) to be written and read within the storage means 5 may be selected. .

Furthermore, the control means 1 may control the operation of the CO detection means 6. Similarly to the control of the smoke sensing means 2 described above, the control means 1 may control, for example, the timing of detecting carbon monoxide gas in the CO detecting means 6 and the timing of outputting the detection signal. The judgment operation by the pronunciation judgment means 4 may be controlled. For example, the timing at which the sound generation means 2 determines whether or not a sound is generated may be controlled by the control means 1, and the determination criteria for the sound generation determination means 4 may be provided from the control means 1 to the sound generation means 4. In addition, when the control means 1 controls the operation of the sound generation means 3, information for determining whether or not sound is generated, and electrical signals such as voltage or current indicating the information are transmitted from the control means 1 to the sound generation determination means 4. may be provided.

The control means 1 may be constituted by, for example, a semiconductor device such as a microcomputer or an ASIC, and its peripheral components as hardware. The control means 1 may be constituted by these hardware and software such as a control program that operates a semiconductor device such as a microcomputer or an ASIC according to a predetermined procedure. Such software may be built into the hardware constituting the control means 1 or may be stored within the storage means 5. The control means 1 has a calculation function, a comparison function, a memory function, a timekeeping function, etc. in order to control the entire alarm operation from monitoring the surrounding environment by the smoke sensing means 2 to issuing an alarm by the sounding means 3 etc. obtain. For example, the pronunciation determining means 4 may be built into the semiconductor device constituting the control means 1.

As described above, the storage means 5 stores various information such as the detected concentration. The storage means 5 may store all of the detected concentrations detected at any time by the control means 1 each time they are detected, and a plurality of detected concentrations detected during a certain period may be statistically processed by the control means 1. Statistical values, such as maximum value, minimum value, average value, median value, mode value, etc., may be stored. Further, the storage means 5 may store information as to whether or not the pronunciation means 3 is operating, which is determined by the pronunciation determining means 4 or is known by the control means 1 itself. As the storage means 5, various memory devices such as random access memory (RAM) are exemplified, but any storage element capable of writing and reading information such as detected concentration may be used as the storage means 5. Further, the storage means 5 may be included in the control means 1, and in that case, the storage means 5 may be a RAM built into a microcomputer or the like that mainly constitutes the control means 1, various registers, or registers, memory, etc. It may also be various identification flags set in the storage space of.

The pronunciation determining means 4 determines whether the pronunciation means 3 is operating, that is, whether the pronunciation means 3 is ringing and a sound is being emitted from the pronunciation means 3. For example, when the control means 1 sends a control signal for the operation of the sound generation means 3, the control signal is monitored by the sound generation determination means 4. If the voltage or current constituting the control signal is greater than or equal to a predetermined value or less than a predetermined value, it is determined that the sound generating means 3 is in operation or in non-operation. Therefore, the pronunciation determining means 4 may be a voltage or current comparison element such as a comparator. Furthermore, when the pronunciation determining means 4 is included in the control means 1, the pronunciation determining means 4 may be a comparison function included in a semiconductor device such as a microcomputer that constitutes the control means 1. In addition, an identification flag (for example, a sound generation identification flag Fs (see FIG. 5), which will be described later), indicates whether or not the sound generation means 3 is in operation using two logical values (high level, low level, etc.) in the control means 1 or storage means 5. )), the pronunciation determining means 4 may be a logic gate element into which the logical value of the identification flag is input.

The CO sensing means 6 detects the presence, preferably the concentration, of carbon monoxide in the surrounding environment. The CO detection means 6 is exemplified by any type of carbon monoxide sensor such as a semiconductor type, an electrochemical type, a catalytic combustion type, or a non-dispersive infrared type. It is sufficient that the presence of carbon monoxide can be detected, and the sensor is not limited to the above-mentioned types of carbon monoxide sensors. In the example of FIG. 1, the CO detection means 6 outputs a detection result, which may be an electrical signal, to the control means 1. In addition to controlling smoke-related alarms, the control means 1 determines whether the detected concentration of carbon monoxide exceeds a predetermined threshold value regarding carbon monoxide based on a predetermined determination method, and makes a decision based on the determination result. Based on this, the alarm operation regarding carbon monoxide may be controlled. In addition to or in place of the CO detection means 6, the smoke detector 100 may include a combustible gas detection means, a temperature detection means, and/or a humidity detection means. In that case, the control means 1 may control the alarm operation regarding the detection target of each of these detection means.

FIG. 2 shows an example of the appearance of an alarm device 200 including the smoke detector 100 of this embodiment. The alarm 200 may be a fire alarm that detects the occurrence of a fire based on the concentration and temperature of surrounding smoke and issues an alarm. The alarm 200 is a composite alarm that issues an alarm by detecting carbon monoxide gas and combustible gases other than carbon monoxide gas, or by detecting the intrusion of outsiders into the room. It's okay. As shown in FIG. 2, in the alarm 200, the components of the smoke detector 100, such as the smoke sensing means 2 and the sounding means 3, are housed in a housing 201. Although not shown in FIG. 2, the housing 201 also houses other components of the smoke detector 100 (for example, the pronunciation determining means 4 and the control means 1 illustrated in FIG. 1). The housing 201 includes an opening 202 and an opening 203 that communicate with the inside of the housing.

The opening 202 is provided over the entire side surface of the casing 201 and functions as an inlet for taking gas such as air around the alarm device 200 into the vicinity of each detection element within the alarm device 200. The opening 203 is formed in a portion of the housing 201 facing the sounding means 3, and the sound emitted from the sounding means 3 is mainly emitted to the outside through the opening 203. The sound generating means 3 emits a sound when smoke with a concentration equal to or higher than a predetermined threshold is detected, when a fire is detected based on the detected smoke, and/or when carbon monoxide gas is detected with a concentration equal to or higher than a predetermined threshold. In addition, as mentioned above, when detecting abnormal conditions based on the temperature and humidity of the surrounding environment, such as flammable gas exceeding a predetermined concentration or excessively high temperature or low humidity, and when notifying the remaining battery power or self-inspection results, etc. Sounds and voices suitable for each state may be emitted from the sound generating means 3 to the outside of the alarm device 200.

FIG. 3 schematically shows how gas such as air flows within the casing 201 of the alarm device 200 of FIG. 2. Air flowing into the interior of the housing 201 from the opening 202 of the housing 201 passes through the smoke inlet 21 provided in the smoke sensing means 2 and flows into the smoke sensing area 22 therein. When the gas flowing into the smoke sensing region 22 contains smoke S, the smoke S is detected by the smoke sensing means 2, and its concentration is detected by the control means 1 (see FIG. 1).

However, when the sounding means 3 operates, the vibration of the air caused by the sounding of the sounding means 3 causes smoke detection to be detected from outside the alarm 200 in the vicinity of the smoke sensing means 2 and around the smoke detector 100 or around the alarm 200. The airflow leading to means 2 may be affected. In particular, the flow of smoke S, which may be present in particulate form in the gas towards the smoke sensing means 2, may be inhibited to a higher degree than the surrounding gas. For example, in the example of FIG. 3, it is considered that the smoke S flowing in from below the sounding means 3 is likely to be affected by the operation of the sounding means 3. In addition, since the sound emitted from the sound generating means 3 may be repeatedly reflected on the inner wall of the housing 201, it is considered that the flow of the smoke S flowing in from any direction may also be obstructed. In particular, as the alarm device 200 becomes smaller, it becomes difficult to spatially separate the flow path to the smoke sensing means 2 and the sounding means 3 regarding the gas that has flowed into the alarm device 200 or the smoke detector 100. Therefore, it becomes difficult to prevent the operation of the sound generating means 3 from affecting the flow of smoke. Even if a partition or the like is provided between the smoke flow path and the sounding means 3, if the partition is vibrated by the sound waves from the sounding means 3, a sufficient prevention effect may not be obtained.

When the flow of smoke is obstructed, the concentration of smoke within the smoke detection area 22, which should normally be at the same concentration as the concentration of smoke around the smoke detector 100 or around the alarm 200, becomes unstable. , the smoke detector 100 may not properly detect the concentration of smoke in its surrounding environment. Specifically, when the flow of smoke to the smoke sensing means 2 is obstructed, the smoke detector 100 is considered to detect a concentration lower than the actual smoke concentration around the smoke detector 100. As a result, even though the area monitored by the smoke detector 100 is actually filled with smoke at a concentration exceeding a predetermined threshold, an alarm based on the smoke concentration, such as a fire alarm, may not be issued in a timely manner. obtain.

In this regard, if smoke detection is always performed in the smoke detector 100, even if the concentration of the detected smoke becomes unstable due to the operation of the sound generating means 3, it will not flow into the smoke sensing area 22 between the vibrations of the gas. By capturing the smoke and detecting its concentration, a predetermined alarm may be issued without noticeable delay. However, if the light-emitting element and the light-receiving element are constantly operated in order to constantly detect smoke in the photoelectric type smoke sensing means 2 as described above, it is thought that the power consumption of the smoke detector 100 will increase unnecessarily. Especially when the alarm device 200 is battery-powered, wasting power is extremely undesirable. Therefore, it is preferable to detect or determine the smoke concentration at intervals that are sufficient to issue an alarm within a delay time defined by laws and regulations, for example.

Therefore, in the smoke detector 100 of this embodiment, as described above, the control means 1 is configured to change the density determination method depending on whether the sounding means 3 is operating or not. ing. Then, when the sounding means 3 is operating, that is, under a situation where the flow of smoke to the smoke sensing means 2 is likely to be obstructed, the control means 1 determines that any one or more of the detected concentrations detected within a predetermined period of time is It is determined whether or not a predetermined threshold value is exceeded. For example, when the sound generating means 3 is operating, the control means 1 detects one or more smoke concentrations (detected concentrations) at time intervals shorter than the length of the predetermined period, and detects one or more smoke concentrations (detected concentrations) within the predetermined period. It is determined whether any one of the preferably plurality of detected concentrations exceeds a predetermined threshold value. Then, the control means 1 determines that the ambient concentration exceeds a predetermined threshold value if at least one of the one or more detected concentrations exceeds a predetermined threshold value every predetermined period. In other words, the control means 1 determines that the ambient concentration exceeds the predetermined threshold even if only the maximum value of the one or more detected concentrations exceeds the predetermined threshold. Therefore, in this embodiment, even if the concentration of smoke within the smoke sensing region 22 is unstable, it is more effective than detecting the concentration of smoke in a predetermined surrounding area and determining whether it exceeds a threshold value. It can be reliably determined that the ambient concentration exceeds the predetermined threshold.

Furthermore, since the influence of the operation of the sounding means 3 on the determination of the ambient concentration can be reduced, the sounding means 3 and the smoke sensing means 2 can be placed close to each other. It may be possible to simplify the smoke detector 100 or realize a smaller smoke detector 100.

On the other hand, when the sound generating means 3 is not operating, it is determined whether the ambient concentration exceeds a predetermined threshold value based on a concentration determination method different from this concentration determination method. For example, when the sound generating means 3 is not operating, the control means 1 detects the concentration of smoke at a predetermined timing, and determines whether the detected concentration exceeds a predetermined threshold value. For example, the concentration of smoke is detected every predetermined period, and it is determined whether the detected concentration exceeds a predetermined threshold value. In this case, smoke concentration detection is not performed at time intervals shorter than the predetermined period. Therefore, even though the sounding means 3 is not operating, that is, even though the flow of smoke to the smoke sensing area 22 is not easily obstructed, the concentration of smoke is frequently detected. unnecessary consumption of power can be avoided. As described above, according to the present embodiment, it is possible to appropriately determine whether the ambient concentration exceeds a predetermined threshold value while avoiding unnecessary power consumption, regardless of whether or not the sound generating means 3 is operating. I can do it.

<Concentration determination method according to the presence or absence of operation of the sound generating means>
The concentration determination method in the smoke detector of this embodiment will be further described with reference to FIGS. 4 to 6. FIG. 4 shows a timing diagram of an example of the operation of the smoke detector of this embodiment based on the concentration determination method in a state where the sound generating means 3 (see FIG. 1) is not operating. In FIG. 4, the ambient concentration Ca is shown in a solid line at the top, and a dashed line indicates a predetermined threshold value Cth, which is a criterion for determining whether to issue an alarm based on the smoke concentration, for example, a fire alarm. It is shown in Immediately below the ambient concentration Ca, the timing of smoke detection by the smoke sensing means 2 (see FIG. 1) and the timing of detection of the detected smoke concentration by the control means 1 (see FIG. 1) are determined by the smoke detection pulse Pd. It is shown. At the time when the smoke detection pulse Pd is generated, for example, a light emitting element and a light receiving element operate in the smoke sensing means 2 to detect smoke within the smoke sensing area 22 (see FIG. 3), and the concentration of the smoke is determined by the control means 1. detected by. Immediately below the smoke detection pulse Pd, a determination pulse Pj indicates the timing for concentration determination by the control means 1 based on the concentration determination method. At the time when the determination pulse Pj is generated, it is determined whether the detected smoke concentration exceeds the threshold value Cth, and if it does, the ambient concentration Ca is assumed to exceed the threshold value Cth, and, for example, Alarms such as fire alarms are issued.

In the example of FIG. 4, as shown by the smoke detection pulse Pd and the determination pulse Pj, each time the control means 1 detects the concentration of smoke detected by the smoke sensing means 2, the control means 1 determines the detected concentration. It is being done. The detection of smoke concentration and the determination of the detected concentration by the control means 1 are performed synchronously at a predetermined timing, and in the example of FIG. 4, these detections and determinations are performed periodically at a predetermined period P1. ing. In this way, the control means 1 may detect the concentration of smoke detected by the smoke detection means 2 at regular intervals when the sound generation means 3 is not operating.

Furthermore, immediately below the determination pulse Pj shown in FIG. 4, an alarm status Sa indicating whether or not an alarm based on the concentration of smoke, for example, a fire alarm, is issued is indicated by a binary value of low level and high level. ing. A low-level alarm state Sa indicates that a smoke-based alarm has not been issued, and a high-level alarm state Sa indicates that a smoke-based alarm has been issued. Note that when it is determined that the ambient concentration Ca exceeds a predetermined threshold value Cth, a sound may be emitted by the sounding means 3 as a fire alarm, for example. However, since FIG. 4 shows the concentration determination method in a state where the sounding means 3 is not operating, even if an alarm based on the smoke density is issued, the sounding means 3 does not operate and other sources such as light It is assumed that the alarm is issued by the alarm means.

Immediately below the alarm status Sa, there is also information indicating when the CO detection means 6 detects carbon monoxide and whether or not the detected concentration of carbon monoxide exceeds a predetermined threshold (not shown). The determination timing is indicated by the CO detection/determination pulse Pco. At the time when the CO detection/judgment pulse Pco is generated, the presence and concentration of carbon monoxide is detected in the CO detection means 6, and it is determined whether the detected concentration exceeds a predetermined threshold value. . Then, depending on the determination result, a warning regarding carbon monoxide is issued. In the example of FIG. 4, the CO detection means 6 detects carbon monoxide and determines its concentration at a constant predetermined period P2. In the example of FIG. 4, the predetermined period P2 is shorter than the predetermined period P1 in which the smoke concentration is detected and determined, but the predetermined period P2 may be longer than the predetermined period P1, and may be the same as the predetermined period P1. Good too.

In FIG. 4, the smoke concentration is detected at time T1 and time T2, and it is determined whether or not it exceeds the threshold value Cth, but at these times, no fire has occurred, and the ambient concentration Ca is also fluctuating. Since the smoke density is not higher than the threshold value Cth, no alarm such as a fire alarm based on the smoke density has been issued, as indicated by the alarm status Sa.

Thereafter, a fire occurs at time T3, and the ambient concentration Ca begins to rise accordingly, exceeding the threshold value Cth at time T4. Since time T4 is not the time to detect and judge the smoke concentration, a fire alarm etc. is not issued at time T4, but at time T5, which is the time to detect and judge the smoke density immediately after, smoke with a concentration exceeding the threshold value Cth is detected. It is detected by the smoke sensing means 2, and its concentration is detected by the control means 1 as a detected concentration. Then, it is determined whether the detected concentration exceeds a predetermined threshold value Cth, and since the detected concentration exceeds the threshold value Cth, an alarm based on smoke concentration such as a fire alarm is issued at a certain time, as indicated by the alarm status Sa. Emitted at T5. At time T6, which is the next smoke concentration detection and determination time after time T5, the alarm continues because the ambient concentration Ca exceeds the threshold value Cth.

Note that since FIG. 4 shows an example in which the concentration of carbon monoxide is below the threshold value regarding the concentration of carbon monoxide, the detection of carbon monoxide by the CO detection means 6 and the determination of its concentration are repeated at a predetermined period P2. However, no warnings regarding carbon monoxide have been issued.

In the example of FIG. 4, as described above, once it is determined that the detected concentration exceeds the predetermined threshold value Cth at time T5, an alarm is immediately issued at time T5. However, even when the sound generating means 3 is not operating, the concentration of smoke in the smoke sensing area 22 temporarily increases due to, for example, cigarette smoke, and by detecting the smoke concentration, the ambient concentration Ca becomes the threshold value Cth. It is also conceivable that it may be mistakenly determined that it exceeds . In that case, a false alarm will be issued by the alarm device 200 (see FIG. 2).

In order to avoid such false alarms, the control means 1 controls, if the detected concentration detected at a predetermined timing exceeds a predetermined threshold value Cth for a predetermined number of times when the sound generation means 3 is not operating. In addition, it may be configured to determine that the surrounding smoke concentration Ca exceeds a predetermined threshold value Cth. By doing so, it may be possible to prevent false alarms due to temporary or instantaneous increases in smoke concentration. The predetermined number of times is preferably a plurality of times, such as two or three times. For example, if the predetermined number of times is two, the alarm based on the smoke density is issued at time T6 instead of time T5 in the example of FIG.

In addition, in order to avoid the above-mentioned false alarm, when the sound generation means 1 is not operating, the control means 1 controls whether the surrounding It may be configured to determine that the smoke concentration Ca exceeds a predetermined threshold value Cth. For example, the concentration of smoke generated by a fire is unlikely to decrease immediately after once exceeding the threshold value Cth, so even when determining in this way, false alarms due to a temporary or instantaneous increase in smoke concentration may occur. There are some things that can be prevented.

FIG. 5 is a timing diagram showing an example of the operation of the smoke detector of this embodiment based on the concentration determination method in a state where the sound generating means 3 (see FIG. 1) is operating. In FIG. 5, the top row shows a sound generation state Ss indicating whether or not the sound generation means 3 is operating with a binary value of low level and high level. A low level sound generation state Ss indicates that the sound generation means 3 is not operating, that is, no sound is being produced, and a high level sound production state Ss indicates that the sound production means 3 is operating, that is, no sound is produced. It shows that there is. Immediately below the sound generation state Ss, as in FIG. 4, the ambient concentration Ca is shown as a solid line, and the predetermined threshold value Cth is shown as a dashed line. Furthermore, along with the ambient concentration Ca, the smoke concentration Cd within the smoke sensing area 22 (see FIG. 3) is also indicated by a broken line. Since the concentration of smoke within the smoke sensing region 22 is the detected concentration detected by the control means 1 (see FIG. 1), the smoke concentration Cd within the smoke sensing region 22 is hereinafter also referred to as "detected concentration Cd". . Similar to FIG. 4, below the ambient concentration Ca, a smoke detection pulse Pd, a determination pulse Pj, an alarm state Sa, and a CO detection/determination pulse Pco are shown in this order.

In FIG. 5, as shown by the sound generation state Ss, the sound generation means 3 starts operating and emits sound at time T10. The sound generation means 3 may start operating based on sound generation factors other than the detection of smoke, for example on the detection of a concentration of carbon monoxide or combustible gas exceeding a predetermined threshold, or on the detection of excessive temperature and humidity. In the example of FIG. 5, at the CO detection/judgment pulse Pco at time T10, a concentration of carbon monoxide exceeding a predetermined threshold value for carbon monoxide is detected, and the sounding means 3 issues a predetermined message to issue an alarm regarding carbon monoxide. An alarm is being sounded. The operation of the sound generating means 3 obstructs the flow of smoke to the smoke sensing area 22, and after time T10, the smoke concentration Cd within the smoke sensing area 22 cannot follow the surrounding concentration Ca and becomes unstable. It undergoes repeated fluctuations. Therefore, if the control means 1 detects and judges the smoke concentration at the predetermined period P1 as in FIG. 4 without changing the concentration determination method, the ambient concentration Ca exceeds the predetermined threshold Cth at time T12. Nevertheless, it is not determined that the ambient concentration Ca exceeds the predetermined threshold value Cth until time point T15 when the detected concentration Cd exceeds the predetermined threshold value Cth while the determination pulse Pj is occurring. That is, although the smoke concentration is detected and determined at time T13 and time T14, neither the detected concentration Cd at time T13 nor the detected concentration Cd at time T14 exceeds the threshold value Cth. No warning will be issued.

However, as shown by the smoke detection pulse Pd in FIG. 5, in the present embodiment, when the sound generating means 3 starts operating at time T10, the detected concentration Cd exceeds the predetermined period P1 for determining whether or not it exceeds the threshold value Cth. The concentration of smoke is detected by the control means 1 at short intervals P3. Then, as described above, when the sound generating means 3 is operating, the control means 1 determines whether one or more of the detected concentrations detected within a predetermined period exceeds a predetermined threshold value. It is configured. In the example of FIG. 5, the signal is detected within the predetermined period P1, which is the same length period as the predetermined period P1, which is the period of detecting and determining the smoke concentration when the sound generating means 3 shown in FIG. 4 is not operating. It is determined whether one or more detected concentrations exceed a predetermined threshold Cth. If any one or more of the one or more detected concentrations exceeds the threshold value Cth, it is determined that the ambient concentration Ca exceeds the predetermined threshold value Cth, and an alarm based on the smoke concentration is issued. Therefore, in the example of FIG. 5, for the ambient concentration Ca exceeding the threshold value Cth at time T12, an alarm is issued at time T13, as indicated by the alarm status Sa.

That is, a detected concentration exceeding the threshold value Cth is detected at least at time T121 between time T11 and time T13 when the determination pulse Pj occurs before time T13. Therefore, even if the detected concentration Cd is below the threshold value Cth at time T13, an alarm is issued. For example, as an alarm, a different alarm sound or alarm message than that up to the time T13 may be emitted from the sounding means 3.

Even after the alarm is issued at time T13, as long as the sounding means 3 is operating as indicated by the sounding state Ss, the control means 1 detects the smoke concentration at the period P3, and detects it within the predetermined period P1. It is determined whether any one or more of the detected concentrations exceeds the threshold value Cth. Therefore, even at time T14, which is the time for determining the smoke concentration after time T13, the detected concentration exceeding the threshold Cth is detected at least at time T131 between time T13 and time T14, so that the detected concentration Cd is the threshold value at time T14. The alarm continues even if it is below Cth. Thereafter, in the period up to time T15, the detected concentration Cd exceeds the threshold value Cth for almost the entire period, so the alarm continues even at time T15.

As described above, in this embodiment, when the sound generating means 3 is operating, control is performed to determine whether any one or more of the detected concentrations detected within a predetermined period exceeds a predetermined threshold value Cth. Since the means 1 is configured, it is possible to immediately issue a smoke-related alarm such as a fire alarm after the ambient concentration Ca exceeds the threshold value Cth. In addition, so that the excess of the threshold value Cth in the ambient concentration Ca is quickly determined in this way, the control means 1 controls the smoke concentration when the sounding means 3 is operating, and when the sounding means 3 is not operating. The concentration may be detected from the smoke detected by the smoke sensing means 2 (see FIG. 1) at a cycle P3 shorter than a fixed cycle (predetermined cycle P1) for detecting the smoke.

In the examples shown in FIGS. 4 and 5, the detection frequency of the smoke concentration is changed depending on whether the sound generating means 3 is operating or not, but the ambient concentration Ca remains at the predetermined threshold Cth. The determination as to whether or not the value exceeds the value is made every predetermined cycle P1 or every predetermined period P1, and the frequency of the decision has not been changed. For example, as long as laws and regulations are complied with, it may be preferable not to change the frequency of determining the ambient concentration in order to prevent an increase in power consumption. In addition, in FIG. 5, when the sound generation means 3 starts operating at time T10, the predetermined period P1 is not newly started, and the predetermined period P1 is changed from time T11, which is the timing for determining the ambient concentration Ca when the sound generation means 3 is not operating. A time point T13, which is when the period P1 has elapsed, is the first time to determine the ambient concentration Ca after the sound generating means 3 starts operating. However, in this embodiment, the control means 1 may start a new predetermined period P1 from the time when the start of operation of the sound generation means 3 is detected. For example, in FIG. 5, whether the ambient concentration exceeds the threshold value Cth may be determined every time a predetermined period P1 elapses from time T10 based on the determination of the detected concentration Cd during the predetermined period P1 with respect to the threshold value Cth. Therefore, the determination cycle of the ambient concentration Ca may change temporarily before and after the start of the operation of the sound generating means 3.

An example of the predetermined period (predetermined period) P1 is a time of 3 seconds or more and 20 seconds or less, and preferably, the predetermined period (predetermined period) P1 may be 6 seconds or more and 12 seconds or less. Moreover, the period P3 may be 0.3 seconds or more and 5 seconds or less, and preferably, the period P3 may be 0.5 seconds or more and 2 seconds or less.

Note that when the sound generating means 3 is operating, by lowering the threshold Cth without changing the concentration determination method as in this embodiment, it is possible to suppress the delay in determining whether the ambient concentration Ca exceeds the threshold. be. However, if the threshold value Cth is simply lowered, there is a risk that an alarm may be issued at an ambient concentration at which an alarm should not be issued, or conversely, an alarm may not be stopped at an ambient concentration at which an alarm should be stopped. Therefore, in this embodiment, the density determination method is changed as described above. Note that after the alarm regarding smoke is issued at time T13 or the like, the threshold value Cth may be lowered by an appropriate reduction width so that the alarm is not issued and stopped repeatedly due to slight fluctuations in the ambient concentration.

Furthermore, in the example of FIG. 5, an alarm is immediately issued at time T13 just because any of the detected concentrations Cd during the predetermined period P1 from time T11 to time T13 exceeds the threshold value Cth. That is, regardless of whether or not the detected concentration Cd exceeds the threshold value Cth during the subsequent predetermined period P1 from time T13 to time T14, an alarm is issued based on the determination of the detected concentration Cd in one predetermined period P1. On the other hand, when the sound generating means 3 is not operating, as described above, it is preferable to determine whether the ambient concentration Ca exceeds the threshold Cth based on the detection concentration Cd exceeding the threshold Cth multiple times. be.

However, when the sound generating means 3 is operating, the flow of smoke toward the smoke sensing area is likely to be obstructed by the sound waves as described above, and as shown in FIG. 5, the detected concentration Cd is not stable and the ambient concentration It decreases more easily than Ca. Therefore, even if the excess of the threshold Cth at the ambient concentration Ca is determined based on the multiple excesses of the threshold Cth at the detected concentration Cd when the sound generating means 3 is not operating, when the sound generating means 3 is operating, the detected concentration Cd is It may be preferable to determine that the ambient concentration Ca exceeds the threshold value Cth only if at least one exceeds the threshold value Cth within one predetermined period P1. In this manner, in the present embodiment, if any one or more of the detected concentrations Cd detected within one predetermined period P1 exceeds the threshold value Cth, it may be determined that the ambient concentration Ca exceeds the threshold value Cth. . In this embodiment, when the sound generating means 3 operates, if two or more of the detected concentrations Cd exceed the threshold Cth within one predetermined period P1, or if the detected concentrations Cd continuously exceed the threshold Cth, the ambient concentration It may be determined that Ca exceeds the threshold value Cth. By doing so, unnecessary alarms due to accidental increases in smoke concentration may be avoided.

In the example of FIG. 5, as indicated by the CO detection/judgment pulse Pco, the predetermined period P2 regarding the detection of the carbon monoxide concentration by the CO detection means 6 (see FIG. 1) and the determination regarding the carbon monoxide concentration by the control means 1 is as follows: There is no change between the non-operating state and the operating state of the sound generating means 3 shown in FIGS. 4 and 5, respectively. That is, in the examples shown in FIGS. 4 and 5, the method for determining whether or not the concentration of carbon monoxide exceeds the threshold value is not changed depending on the operation of the sound generating means 3. In this way, the method for determining whether the carbon monoxide concentration exceeds the threshold value may be the same whether the sounding means 3 is operating or not. Since the flow of carbon monoxide is less affected by sound waves than smoke, it is preferable in terms of suppressing an increase in power consumption to not change the determination method for determining whether the threshold has been exceeded depending on whether or not the sound generating means 3 is activated. be.

In FIG. 5, below the CO detection/judgment pulse Pco, a sound generation identification flag Fs indicating whether the sound generation means 3 is operating or not, and a storage means 5 for the detected concentration detected by the control means 1 (see FIG. A detected concentration write pulse Pw indicating writing to the data (see) and a maximum value update pulse Pr indicating updating of the maximum detected concentration within each predetermined period P1 stored in the storage means 5 are shown in order. The pronunciation identification flag Fs is provided, for example, in a specific storage area in the storage means 5 or in a storage device that has a storage function of the control means 1, and is set in a specific storage area in the storage means 5 or in a storage device that has a storage function of the control means 1. 3 is set to a high level (“true (1)”) or low level (“false (0)”) when it is operating, and vice versa when it is not operating. In FIG. 5, as shown by the sound generation state Ss, when the sound generation means 3 is not operating, it is set to a low level, and when it is operating, it is set to a high level. The control means 1 may grasp whether the sound generation means 3 is in operation by referring to the sound generation identification flag Fs set in the storage means 5 or the control means 1 in this way.

The detected concentration write pulse Pw indicates that the detected concentration Cd is written into the storage means 5, and the detected concentration Cd is written into the storage means 5 at the time when the detected concentration write pulse Pw is generated. That is, in the example of FIG. 5, a detected concentration writing pulse Pw is generated every time a smoke detection pulse Pd is generated, and all detected concentrations detected in each predetermined period P1 are stored. The control means 1 reads out these stored detected concentrations from the storage means 5 at the time of determining the ambient concentration such as time T13 or time T14, and determines whether any of the detected concentrations Cd exceeds the threshold value Cth. You may judge. The detected concentration stored in the storage means 5 for each predetermined period P1 may be erased every time each predetermined period P1 elapses, or may be overwritten by the detected concentration detected in the next predetermined period P1.

The maximum value update pulse Pr is such that the maximum value of the detected concentration Cd in each predetermined period P1 is stored in the storage means 5, and the detected concentration Cd stored as the maximum value is updated every time a larger detected concentration Cd is detected. (overwritten). That is, each time the smoke concentration is detected in cycle P3, the detected concentration is compared with the detected concentration stored as the maximum value in the storage means 5, and if the detected concentration is higher, it is set as the maximum value. The stored concentration is updated. In the example of FIG. 5, the density stored as the maximum value has been updated at the time when the maximum value update pulse Pr is occurring. For example, at time T111, the detected concentration Cd at time T11, which was stored as the maximum value at time T11, is overwritten by the detected concentration Cd at time T111. Note that the concentration stored as the maximum value is cleared every time the predetermined period P1 elapses.

In this way, the maximum value of the detected concentration Cd in each predetermined period P1 may be stored in the storage means 5. Then, the control means 1 reads out the concentration stored as the maximum value from the storage means 5 at the time of determining the ambient concentration such as time T13 or time T14, and determines whether the read concentration exceeds the threshold value Cth. It may also be determined whether or not there is one.

Similar to FIG. 5, FIG. 6 shows a timing diagram of an example of the operation of the smoke detector of this embodiment based on the concentration determination method when the sound generating means 3 (see FIG. 1) is operating. There is. FIG. 6 shows an example of the operation of the smoke sensor in a situation where the ambient concentration Ca decreases to below the threshold value Cth due to natural extinguishment of a small fire, for example, and the smoke alarm is stopped. Similar to FIG. 5, FIG. 6 shows the ambient concentration Ca, the detected concentration Cd, the threshold value Cth, the smoke detection pulse Pd, the determination pulse Pj, and the alarm state Sa. The sound generation state Ss, CO detection/judgment pulse Pco, sound generation identification flag Fs, detected density writing pulse Pw, and maximum value update pulse Pr are omitted. In FIG. 6, during the period up to time T24, as indicated by the alarm status Sa, an alarm such as a fire alarm based on the concentration of smoke is issued.

Also in FIG. 6, since the sound generating means 3 is operating, the detected concentration Cd deviates from the ambient concentration Ca and repeats fluctuations. Therefore, also in FIG. 6, it is determined whether the ambient concentration Ca exceeds the threshold value Cth based on the same concentration determination method as that described with reference to FIG. That is, the control means 1 (see FIG. 1) detects the concentration of smoke in a period P3, and determines that the ambient concentration Ca is higher than the threshold value Cth if any one or more of the detected concentrations Cd detected within the predetermined period P1 exceeds the threshold value Cth. It is determined that the threshold value Cth is exceeded. Therefore, at time T22, the detected concentration Cd is lower than the threshold Cth, but during the predetermined period P1 from time T21 to time T22, for example, the detected concentration Cd at time T211 exceeds the threshold Cth, so the alarm state Sa is As shown, the alarm continues without being stopped. At time T23, the ambient concentration Ca is already below the threshold Cth at time T222, but the alarm is not stopped because the detected concentration Cd at time T221 exceeds the threshold Cth during the predetermined period P1 from time T22.

Thereafter, at time T231, the ambient concentration Ca decreases to a steady state, and at time T24, which is the time for determining the subsequent ambient concentration Ca, all detected concentrations Cd during the predetermined period P1 from time T23 are below the threshold Cth. , as indicated by the alarm status Sa, alarms such as fire alarms based on the concentration of smoke are stopped. In FIG. 6, the detected concentration Cd continues to fluctuate after the time T24, but the operation of the sounding means 3 may also be stopped when the alarm stops at the time T24. In that case, the detected concentration Cd is equal to the ambient concentration. It is considered to be stable at approximately the same concentration as Ca.

In this way, in the example of FIG. 6, when the alarm based on the smoke concentration is issued and the sounding means 3 is operating, the control means 1 controls a part of the detected concentration Cd detected within the predetermined period P1 to reach the threshold value Cth. The alarm will not stop even if the following occurs. In this embodiment, when an alarm based on smoke concentration is issued and the sounding means 3 is operating, the control means 1 controls such that all detected concentrations Cd within the predetermined period P1 exceed the threshold value Cth. It may be configured to stop issuing the alarm when the temperature drops below the threshold. The flow of smoke is obstructed by the sounding of the sounding means 3, and as a result, it may be possible to prevent the alarm being issued from being stopped hastily.

<Example of operation flow of the smoke detector of this embodiment>
FIGS. 7A and 7B show flowcharts of an example of the operation of the smoke detector of this embodiment. FIG. 7A illustrates the operation of the smoke detector when the sounding means 3 (see FIG. 1) is not operating, and FIG. 7B illustrates the operation of the smoke detector when the sounding means 3 is operating. There is. In particular, FIG. 7A shows an example of the operation of a smoke detector that determines that the ambient concentration exceeds a predetermined threshold when the detected concentration exceeds the predetermined threshold for a predetermined number of times N. . Note that, in parallel with the operations shown in FIGS. 7A and 7B, the sound generation determination means 4 (see FIG. 1) determines whether or not the sound generation means 3 is operating, and based on that determination, the control means 1 (see FIG. 1), the control shown in FIG. 7A or FIG. 7B is executed.

As shown in FIG. 7A, when it is determined that the sound generating means is inactive (step S0), a count value n that is counted each time a detected concentration exceeding a predetermined threshold is detected is cleared ( Step S1). The count value n is counted by, for example, an element of the control means 1 that has a memory function or an arithmetic function. Further, the count value n may be stored in the storage means 5 (see FIG. 1), and counted and cleared under the control of the control means 1. Thereafter, in step S2, it is determined whether a predetermined timing for detecting the smoke density has arrived. For example, it is determined whether a predetermined period P1 (see FIG. 4) has elapsed since the previous smoke density detection. If the predetermined timing has not arrived (“N” in step S2), the determination in step S2 is repeated.

If the predetermined timing has arrived ("Y" in step S2), the density of smoke detected by the smoke sensing means 2 (see FIG. 1) is detected (step S3). Subsequently, it is determined whether the detected concentration exceeds a predetermined threshold (step S4). If the detected concentration exceeds the threshold (“Y” in step S4), the count value n is incremented by 1 (step S5), and it is determined whether the count value n has reached a predetermined number of times N. (Step S6). If the count value n is less than the predetermined number of times N (“N” in step S6), the control is returned to step S2, and the detection of the smoke density according to the arrival of the predetermined timing is repeated. If the count value n has reached the predetermined number of times N in step S6 (“Y” in step S6), an alarm based on the smoke concentration, such as a fire alarm, is issued (step S7), and then the control returns to step S1. .

On the other hand, if the detected smoke concentration does not exceed the predetermined threshold ("N" in step S4), it is determined whether or not an alarm is already being issued (step S8); (“N” in step S8), the control is returned to step S2, and detection of the smoke density according to the arrival of a predetermined timing is repeated. If the alarm is already being issued ("Y" in step S8), the alarm is stopped (step S9), and then control is returned to step S2.

Note that if an alarm is issued when a detected concentration exceeding a predetermined threshold is detected only once, steps S1, S5, and S6 are omitted. Further, if an alarm is issued when a detected concentration exceeding a predetermined threshold is detected N times in a row, the count value n is cleared between steps S4 and S8.

On the other hand, as shown in FIG. 7B, when the sound generating means 3 starts operating (step S10), a predetermined smoke concentration detection period (for example, period P3 in the example of FIG. 5) is set from the previous smoke concentration detection timing. ) has elapsed (step S11). If the detection cycle time has not elapsed (“N” in step S11), the determination in step S11 is repeated.

If the detection period has elapsed (“Y” in step S11), the concentration of smoke detected by the smoke sensing means 2 is detected (step S3). The detected concentration detected in step S3 may be stored in the storage means 5 (see FIG. 1), and if the storage means 5 stores the maximum value of the detected concentration during a predetermined period, the detected concentration detected in step S3 is The maximum value stored in the storage means 5 may be updated according to the comparison result between the detected concentration and the stored maximum value.

Next, it is determined whether a predetermined period (for example, the predetermined period P1 in FIG. 5) has elapsed since the previous ambient concentration determination time (step S12), and if the predetermined period has not elapsed (in step S12, " N''), the control is returned to step S11 and detection of the smoke concentration according to the passage of the detection period is repeated. On the other hand, if the predetermined period has elapsed (“Y” in step S12), it is determined whether one or more of the detected concentrations during the predetermined period exceed a predetermined threshold (step S13). In the determination in step S13, the detected concentration or its maximum value during a predetermined period stored in the storage means 5 may be referred to.

If at least one of the detected concentrations during the predetermined period exceeds the threshold (“Y” in step S13), an alarm such as a fire alarm based on the smoke concentration is issued (step S7), and then the control returns to step S11. be returned. On the other hand, if none of the detected concentrations during the predetermined period exceeds the predetermined threshold value ("N" in step S13), it is determined whether or not an alarm is already being issued (step S8), and it is determined that the alarm is not being issued. If so (“N” in step S8), the control returns to step S11, and detection of the smoke concentration according to the elapse of the detection period is repeated. If the alarm is already being issued ("Y" in step S8), the alarm is stopped (step S9), and then control is returned to step S11.

Note that the embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments described above, and further includes all changes (modifications) within the meaning and range equivalent to the claims.

For example, the frequency of detecting the smoke density while the sounding means is operating may be changed depending on the frequency and volume of the sound emitted from the sounding means. For example, the higher the frequency and/or the louder the volume, the more frequently the smoke concentration may be detected. Further, when a plurality of sounding means such as a buzzer and a speaker are provided, the density determination method during operation of each sounding means may be selected depending on the position of the plurality of sounding means. For example, the smoke density may be detected more frequently when the sounding means disposed closer to the smoke sensing means is operated. Furthermore, in the smoke detector of this embodiment, the sound generating means may emit a sound that includes the resonance frequency of the casing in which the smoke detector is housed. In this embodiment, since the determination of the ambient concentration is not easily influenced by sound waves, it is considered that even if the sound of the sound generating means resonates, the determination that the ambient concentration exceeds the predetermined threshold value is unlikely to be delayed. By emitting a sound that resonates with the housing, it may be possible to notify users further away of the occurrence of an abnormal situation such as a fire.

In the above embodiment, for convenience of explanation, the processing operation of the smoke detector of the embodiment has been explained using a flow-driven flowchart in which the processing is performed sequentially along the processing flow, but the present invention is not limited to this. In the present invention, the processing operation of the smoke detector may be performed by event-driven processing in which processing is executed on an event-by-event basis. In this case, it may be completely event-driven, or it may be a combination of event-driven and flow-driven.

100 Smoke detector 1 Control means 2 Smoke detection means 22 Smoke detection area 3 Sound generation means 4 Sound generation determination means 5 Storage means 6 CO detection means 200 Alarm Ca Ambient concentration Cd Smoke concentration in the smoke detection area (detected concentration)
Cth Predetermined threshold value Fs Sound generation identification flag Pd Smoke detection pulse Pj Judgment pulse P1 Predetermined period (predetermined period)
P3 Concentration detection cycle Sa during sound generation Alarm status Ss Sound generation status

Claims (8)

a smoke sensing means for detecting smoke;
A sounding means that emits a sound when operating;
pronunciation determining means for determining whether or not the pronunciation means is operating;
A control means for determining whether the smoke concentration exceeds a threshold value based on a predetermined determination method and controlling an alarm operation;
A smoke detector comprising:
The control means includes:
Detecting the concentration from the smoke detected by the smoke sensing means,
Based on the determination result of the pronunciation determining means, changing the determination method depending on whether the pronunciation means is operating or not;
when the sounding means is operating, determining whether any one or more of the detected concentrations detected within a predetermined period exceeds the threshold;
Smoke detectors. The control means determines whether the detected concentration exceeds the threshold value at a predetermined timing when the sound generation means is not operating.
The smoke detector according to claim 1. The control means determines that the smoke concentration exceeds the threshold value when the detected concentration detected at the predetermined timing exceeds the threshold value a predetermined number of times when the sound generation means is not operating.
The smoke detector according to claim 2. The control means includes:
When the sounding means is operating, determining that the smoke concentration exceeds the threshold if any one or more of the detected concentrations detected within one predetermined period exceeds the threshold;
When the sounding means is not operating, determining that the smoke concentration exceeds the threshold if the detected concentration detected at the predetermined timing exceeds the threshold several times in a row;
The smoke detector according to claim 2 or 3. The control means includes:
When the sounding means is not operating, detecting the concentration of smoke detected by the smoke sensing means at regular intervals;
When the sounding means is operating, detecting the concentration from the smoke detected by the smoke sensing means at a cycle shorter than the fixed cycle;
The smoke detector according to any one of claims 1 to 4. further comprising a CO detection means for detecting carbon monoxide concentration,
The control means controls an alarm operation by determining whether the carbon monoxide concentration exceeds a threshold value based on a predetermined determination method,
Any one of claims 1 to 5, wherein the method for determining whether the carbon monoxide concentration exceeds the threshold is the same when the sounding means is operating and when the sounding means is not operating. Smoke detectors listed in . The smoke detector according to any one of claims 1 to 6, further comprising storage means for storing all or the maximum value of the detected concentrations detected within the predetermined period. The smoke detector according to any one of claims 1 to 7, further comprising storage means for storing information regarding whether or not the sound generation means is operating.

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