Fire sensor

Abstract

To provide a fire sensor having a simple function capable of avoiding a non-fire alarm accompanying a cleaning work.SOLUTION: In a fire sensor installed in a fire monitoring area and comprising a sensing unit which senses occurrence of a fire, the fire sensor further comprises: a mode setting unit which can switch settings between a monitoring mode and a non-monitoring mode in order to prevent a false detection occurrence of a fire due to a cleaning work. The sensing unit executes a non-monitoring control that does not output a sensing result when the non-monitoring mode is set.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a fire detector, and more particularly to a fire detector for preventing false fire alarms from occurring during cleaning work. [Background technology]

[0002] Fire alarm systems use various types of fire detectors to detect fires, including heat detectors, flame detectors, and smoke detectors, which include photoelectric split detectors and photoelectric spot detectors.

[0003] Regardless of the type, there is a risk of false alarms or failure to alarm due to factors such as dirt. Here, "false alarms" refers to the fire detector being activated by a cause other than fire and issuing an alarm even though there is no fire, i.e., falsely detecting that a fire has occurred. "Failure to alarm" refers to the failure to issue an alarm even though a fire has occurred.

[0004] Therefore, fire detectors are cleaned to prevent deterioration of detection accuracy and to prevent false fire alarms and missed alarms (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-156127 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional techniques have the following problems. When cleaning detectors, it is effective to put the detectors into an unmonitored state to avoid false fire alarms during the cleaning work. However, currently there is no easy function to put the detectors into an unmonitored state during cleaning work.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a fire detector with simple functions that can avoid false fire alarms that occur during cleaning work. [Means for solving the problem]

[0008] The fire detector according to the present disclosure is a fire detector provided in a fire monitoring area and having a detection unit that detects the occurrence of a fire, The fire detector is a photoelectric separation type detector in which a light-transmitting unit and a light-receiving unit are arranged opposite each other, and detects the occurrence of a fire by detecting a decrease in the amount of light received by the light-receiving unit when the light emitted from the light-transmitting unit is blocked, In order to prevent false detection of a fire occurring during cleaning work, a mode setting unit is further provided which can switch between a monitoring mode and a non-monitoring mode, and when the non-monitoring mode is set, the detection unit executes non-monitoring control which does not output the detection result. The light receiving level at the light receiving unit immediately after switching from the monitoring mode to the non-monitoring mode is stored as the light receiving level before cleaning, and in the non-monitoring mode, cleaning of the light transmitting unit window and the light receiving unit window is performed as a cleaning work, and the light receiving level after the cleaning work is completed is compared with the light receiving level before cleaning, and the following formula is used: Light reception level before cleaning < Light reception level after cleaning If the above is true, the cleaning work is judged to have been carried out normally, and the following formula is applied: Light reception level before cleaning ≥ Light reception level after cleaning If this is true, it is determined that the dirt on the window could not be completely removed or that the optical axis has shifted, making it impossible to monitor properly. It is something. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to obtain a fire detector with a simple function that can avoid false fire alarms that occur during cleaning work. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an overall configuration diagram of a fire alarm system including a fire detector according to a first embodiment of the present disclosure. [Figure 2] 1 is an explanatory diagram showing a first configuration of a fire detector according to a first embodiment of the present disclosure, the fire detector having a function of avoiding false fire alarms associated with cleaning work. FIG. [Figure 3]FIG. 10 is an explanatory diagram showing a second configuration of the fire detector according to the first embodiment of the present disclosure, which has a function of avoiding false fire alarms associated with cleaning work. [Figure 4] FIG. 2 is an explanatory diagram relating to a cleaning operation of the flame detector according to the first embodiment of the present disclosure. [Figure 5] FIG. 2 is an explanatory diagram relating to a cleaning operation of the separated photoelectric sensor according to the first embodiment of the present disclosure. [Figure 6] FIG. 2 is an explanatory diagram relating to a cleaning operation of the photoelectric spot type sensor according to the first embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, preferred embodiments of the fire detector of the present disclosure will be described with reference to the drawings. The fire detector according to the present disclosure has a technical feature of being provided with a simple configuration that can be changed to a non-monitoring mode in which the detection result is not output for a desired period of time.

[0012] Embodiment 1 First, we will explain the overall picture of the system including the fire detector. Fig. 1 is a diagram illustrating the overall configuration of a fire alarm system including fire detectors according to the first embodiment of the present disclosure. Specifically, the fire alarm system illustrated in Fig. 1 includes, as main components, a fire receiver 10 and a plurality of fire detectors.

[0013] The fire control receiver 10 is connected to the addressable transmitter 20, fire detectors 31 and 32, detector repeater 40, and smoke control repeater 50 via a signal line SG.

[0014] A plurality of fire detectors are connected to the detector repeater 40. In Fig. 1, four fire detectors 41 to 44 are shown as an example. In addition, a fire door 51, a smoke exhaust machine 52, a shutter 53, and a hanging wall 54 are connected to the smoke prevention and exhaust control repeater 50.

[0015] Here, the fire detectors 31, 32 and the fire detectors 41 to 44 correspond to a plurality of fire detectors that detect the occurrence of a fire in each of the preset fire monitoring areas. A plurality of fire detectors constitutes a detector group.

[0016] The fire detectors 41 to 44 may be so-called general-type detectors, and an address is assigned to the detector repeater 40, and communication is carried out between the fire receiver 10 and the detector repeater 40. When the detector repeater 40 is used, the fire detectors 41 to 44 can be grouped together and set to a monitoring mode or a non-monitoring mode, which will be described later.

[0017] In addition, the fire door 51, the smoke exhauster 52, the shutter 53, and the hanging wall 54 correspond to a plurality of terminal equipment that operate in conjunction with the detection results of the plurality of fire detectors and function to prevent the spread of fire, smoke, etc. A terminal equipment group is made up of a plurality of terminal equipment.

[0018] Address information for identifying each individual fire detector is assigned in advance to each of the multiple fire detectors. Each of the multiple fire detectors can transmit fire-related information including the address information assigned to it to the fire control panel 10. Meanwhile, the fire control panel 10 can transmit required information to a desired fire detector by adding address information to the information.

[0019] Furthermore, each of the multiple terminal devices is assigned address information in advance to identify the individual terminal device. Therefore, the fire control device 10 can transmit a command to operate the desired terminal device by adding the address information and transmitting the information.

[0020] With this configuration, the fire receiving device 10 collects fire-related information from a plurality of fire detectors installed in various predetermined fire monitoring areas and the addressable transmitter 20. Then, the fire receiving device 10 can issue a fire alarm and activate a group of terminal equipment based on the collected fire-related information.

[0021] It is to be noted that each terminal equipment included in the terminal equipment group is specified in advance as to which fire detector detection result it should operate in conjunction with. For example, by setting in advance the correspondence between the interlocking operations of multiple fire detectors and multiple terminal equipment as an interlocking table, the fire receiving device 10 can identify the appropriate terminal equipment from the interlocking table based on the detection results of each of the multiple fire detectors and perform interlocking operations.

[0022] Also, although not shown in the figure, the fire receiver 10 can output an alarm signal based on the collected fire-related information, activate fire extinguishing equipment to begin fire extinguishing operations, issue a fire alarm or provide evacuation guidance using an emergency broadcast device, and transmit fire-related information to a higher-level device via a network.

[0023] In the above explanation, an example has been given in which address information for identifying each of a plurality of fire detectors is assigned in advance, and information is transmitted between the fire receiver 10 and each of the fire detectors via a communication function, but the fire detectors according to the present disclosure are not limited to this type.Fire detectors according to the present disclosure also include fire detectors of a type that do not have a communication function for receiving information from the fire receiver 10 and that are configured to output a contact signal when a fire is detected.

[0024] In any type of fire detector, cleaning is performed to prevent a deterioration in detection accuracy and to prevent false fire alarms and missed alarms. Therefore, the following describes in detail the function of preventing false fire alarms that accompanies cleaning work, using flame detector 110, photoelectric separate detector 120, and photoelectric spot detector 130 as specific examples of fire detectors.

[0025] In the following explanation, the flame detector 110, the photoelectric separate detector 120, and the photoelectric spot detector 130 will be collectively referred to as the fire detector 100, and the concept of the function to avoid false fire alarms during cleaning work will be explained using Figures 2 and 3.

[0026] 2 is an explanatory diagram showing a first configuration of the fire detector 100 according to the first embodiment of the present disclosure, which has a function of avoiding false fire alarms associated with cleaning work. The fire detector 100 shown in FIG. 2 includes a mode setting unit 101 and a sensing unit 102.

[0027] The mode setting unit 101 has a function of being able to switch between a monitoring mode and a non-monitoring mode in order to prevent erroneous detection of a fire occurring during cleaning work. The mode setting unit 101 outputs a trigger signal for switching to the non-monitoring mode upon receiving an external signal for switching from the monitoring mode to the non-monitoring mode. The mode setting unit 101 is provided with a timer for measuring a set time, which will be described later.

[0028] The sensing unit 102 is installed in a fire monitoring area, and in normal monitoring mode, executes sensing control to output a sensing result when it detects the occurrence of a fire. Furthermore, when the sensing unit 102 receives a trigger signal from the mode setting unit 101, it switches the setting from the monitoring mode to the non-monitoring mode and executes non-monitoring control to not output a sensing result.

[0029] The sensing unit 102 performs unmonitored control from the time it receives the trigger signal until a predetermined set time has elapsed, and after the set time has elapsed, it switches the setting from unmonitored mode to monitored mode and can return to normal monitored control.

[0030] It is also possible to adopt a configuration in which the mode setting unit 101 switches the setting from monitoring mode to non-monitoring mode between receiving an external signal and the time a predetermined set time has elapsed, and the sensing unit 102 receives a non-monitoring mode signal from the mode setting unit 101.

[0031] By providing a configuration capable of executing such unmonitored control, a fire detector with a simple function that can avoid false fire alarms during cleaning work can be realized. In particular, the first configuration shown in Fig. 2 can be adopted even if the fire detector 100 does not have the function of receiving a signal from the fire receiver 10. For example, the mode setting unit 101 can be realized as a magnetic switch that receives magnetic force as an external signal and can switch from an OFF state to an ON state by this magnetic force.

[0032] 3 is an explanatory diagram showing a second configuration of the fire detector according to the first embodiment of the present disclosure, which has a function of avoiding false fire alarms associated with cleaning work. The fire detector 100 shown in FIG. 3 includes a mode setting unit 101a and a sensing unit 102.

[0033] The mode setting unit 101a has a function of being able to switch between a monitoring mode and a non-monitoring mode to prevent erroneous detection of a fire occurring during cleaning work. However, compared to the mode setting unit 101 in Fig. 2, the mode setting unit 101a in Fig. 3 receives an external signal for switching the setting from the monitoring mode to the non-monitoring mode as a non-monitoring mode setting command output from the fire control device 10. Upon receiving the external signal from the fire control device 10, the mode setting unit 101a outputs a trigger signal for switching to the non-monitoring mode.

[0034] The sensing unit 102 is installed in a fire monitoring area, and in normal monitoring mode, executes a sensing control to output a sensing result when it detects the occurrence of a fire. Furthermore, when the sensing unit 102 receives a trigger signal from the mode setting unit 101a, it switches the setting from the monitoring mode to the non-monitoring mode and executes a non-monitoring control to not output a sensing result.

[0035] The sensing unit 102 performs unmonitored control from the time it receives the trigger signal until a predetermined set time has elapsed, and after the set time has elapsed, it switches the setting from unmonitored mode to monitored mode and can return to normal monitored control.

[0036] It is also possible to adopt a configuration in which the mode setting unit 101a switches the setting from monitoring mode to non-monitoring mode between receiving an external signal and the time a predetermined set time has elapsed, and the sensing unit 102 receives a non-monitoring mode signal from the mode setting unit 101a.

[0037] By providing a configuration capable of executing such unmonitored control, a fire detector with a simple function that can avoid false fire alarms that occur during cleaning work can be realized. In particular, the second configuration shown in Figure 3 can be adopted when the fire detector 100 has a function that can receive signals from the fire receiver 10. In this case, the setting to the unmonitored mode and mode management can be performed on the fire receiver 10 side.

[0038] Next, the unmonitored control function of the present disclosure will be described in detail using a specific example in which the flame detector 110, the photoelectric separate detector 120, and the photoelectric spot detector 130 are used as the fire detector 100.

[0039] <1> When the flame detector 110 is used as the fire detector 100 4 is an explanatory diagram relating to the cleaning work of flame detector 110 according to the first embodiment of the present disclosure. As shown in FIG. 4, existing flame detector 110 is provided with test light source 111 and test light receiving element 112 for monitoring for contamination of light receiving window 113. Light emitted from test light source 111 is received by test light receiving element 112 to detect contamination of light receiving window 113.

[0040] The flame detector 110 detects infrared rays and flame fluctuations specific to a flame to determine whether a fire has occurred. However, if the light receiving window 113 becomes dirty, the fire monitoring area cannot be monitored properly, which may result in a false alarm.

[0041] Therefore, when a contamination alarm is issued because the amount of light received by the test light receiving element 112 falls below a predetermined value, the confirmation light 114 is turned on or flashes to notify the user that the light receiving window 113 needs to be cleaned.

[0042] Here, the flame detector 110 is generally mounted at a high location. For this reason, scaffolding is required to remove the flame detector 110 for cleaning. Therefore, in order to reduce the effort required for scaffolding, a rag is wrapped around the end of a stick and used to wipe the light receiving window 113 of the flame detector 110 mounted at a high location. However, when wiping is performed using a rag in this way, light blocking and light receiving are repeated, and if this cycle meets certain conditions, there is a risk that the cleaning operation will be erroneously determined to be a fire.

[0043] Therefore, in order to prevent such erroneous judgments, the flame detector 110 according to the first embodiment can be set to an unmonitored mode, thereby performing unmonitored control so that the detection result is not output during cleaning work.

[0044] Specifically, the flame detector 110 receives an external signal from the fire receiver 10 to switch the setting from monitoring mode to non-monitoring mode, thereby stopping fire monitoring by the flame detector 110 for a certain period of time and executing non-monitoring control in which the detection results are not output.

[0045] In actual operation using a plurality of flame detectors 110, in order to prevent the entire system from going unmonitored, it may be possible to specify an address and place each flame detector 110 in unmonitored mode one by one.

[0046] In addition, to prevent the non-monitoring mode from continuing even after the cleaning work has been completed, it is possible to switch to the monitoring mode after a certain period of time has passed, but to add a function that immediately returns to the monitoring mode after the cleaning work has been completed.

[0047] <2> When the photoelectric separated detector 120 is used as the fire detector 100 Fig. 5 is an explanatory diagram relating to the cleaning work of photoelectric separated sensor 120 according to the first embodiment of the present disclosure. As shown in Fig. 5, in the existing photoelectric separated sensor 120, light transmitting unit 121 and light receiving unit 122 are arranged opposite each other, and when smoke is generated between light transmitting unit 121 and light receiving unit 122, the light emitted from light transmitting unit 121 is blocked, and a decrease in the amount of light received by light receiving unit 122 is detected to determine whether a fire has occurred.

[0048] When performing such detection, if the window of light-transmitting unit 121 or the window of light-receiving unit 122 becomes dirty, the output will decrease and smoke will not be detected properly, which may result in a false fire alarm or a missed alarm. Therefore, cleaning of the windows of light-transmitting unit 121 and light-receiving unit 122 is required.

[0049] When window cleaning work is performed, the cleaning may cause the orientation of light-transmitting unit 121 or the orientation of light-receiving unit 122 to shift, causing the optical axis of light-transmitting unit 121 and the optical axis of light-receiving unit 122 to shift, which may prevent normal monitoring after the cleaning work. Furthermore, because the light emitted from light-transmitting unit 121 is blocked during cleaning, there is a risk that dimming caused by the cleaning work may be erroneously determined to be a fire or malfunction.

[0050] Therefore, in order to prevent such erroneous judgments, the photoelectric separated sensor 120 according to the first embodiment can be set to an unmonitored mode, thereby performing unmonitored control so that the detection result is not output during cleaning work.

[0051] Specifically, the photoelectric separated detector 120 receives an external signal from the fire receiver 10 to switch the setting from monitoring mode to non-monitoring mode, thereby stopping fire monitoring by the photoelectric separated detector 120 for a certain period of time and executing non-monitoring control in which the detection results are not output.

[0052] In addition, the photoelectric separated sensor 120 according to the first embodiment also has the function of storing the light receiving level at the light receiving unit 122 immediately after switching from monitoring mode to non-monitoring mode as the light receiving level before cleaning, and comparing it with the light receiving level after the cleaning work is completed.

[0053] By having such functions, the photoelectric separated sensor 120 according to the first embodiment can: Light reception level before cleaning < Light reception level after cleaning If so, it can be determined that the cleaning work was carried out properly. Light reception level before cleaning ≥ Light reception level after cleaning If this is the case, it can be determined that the dirt on the window was not completely removed, or that the optical axis has shifted, making it impossible to monitor properly.

[0054] In actual operation using multiple photoelectric separated sensors 120, in order to prevent the entire system from going unmonitored, it is possible to specify an address and put each photoelectric separated sensor 120 into unmonitored mode one by one.

[0055] In addition, to prevent the non-monitoring mode from continuing even after the cleaning work has been completed, it is possible to switch to the monitoring mode after a certain period of time has passed, but to add a function that immediately returns to the monitoring mode after the cleaning work has been completed.

[0056] As a means for automatically detecting whether the cleaning work has been completed, a pressure sensor or the like may be provided in the fire detector itself so that it can detect the external force caused by the cleaning work, and when it is detected that the specified external force has ceased to be applied for a certain period of time, it may be determined that the cleaning work has been completed.

[0057] <3> When the photoelectric spot detector 130 is used as the fire detector 100 6 is an explanatory diagram relating to cleaning work of the photoelectric spot type sensor 130 according to the first embodiment of the present disclosure. As shown in FIG. 6, in the existing photoelectric spot type sensor 130, light emitted from the light-emitting unit 131 inside the optical stand is scattered by smoke and received by the light-receiving unit 132, thereby determining whether a fire has occurred.

[0058] The photoelectric spot detector 130 determines whether the sensor of the light receiving unit 132 is dirty by comparing the light receiving level at the time of monitoring with the light receiving level at the time of factory setting in a smokeless state.

[0059] Cleaning work is carried out by removing dust with a vacuum cleaner or air spray, but during this cleaning work, dust inside the optical table becomes airborne, increasing scattered light and potentially leading to a false detection of a fire.

[0060] Therefore, in order to prevent such erroneous judgments, the photoelectric spot-type sensor 130 according to the first embodiment can be set to an unmonitored mode, thereby performing unmonitored control so that the detection result is not output during cleaning work.

[0061] Specifically, the photoelectric spot type detector 130 receives an external signal from the fire receiver 10 to switch the setting from monitoring mode to non-monitoring mode, thereby stopping fire monitoring by the photoelectric spot type detector 130 for a certain period of time and executing non-monitoring control in which the detection results are not output from the light receiving unit 132.

[0062] When using the photoelectric spot detector 130, a sudden change in the light reception level is judged to be a fire. However, dirt accumulates gradually, and it usually takes time to judge the dirt level, so the effect of cleaning cannot be confirmed in a short time after cleaning.

[0063] Therefore, the photoelectric spot type sensor 130 according to the first embodiment has the function of checking the sensitivity after cleaning using the received light output for a short period of time (for example, one minute) by performing a specific operation after the cleaning work is completed while the non-monitoring mode is set.

[0064] As an example, when the cleaning mode ends, the sensing unit 102 can be provided with a function to calculate the average light reception level for one minute from the time indicating the completion of cleaning by a specific operation as the light reception level after cleaning and determine whether the light reception level has reached the factory-set light reception level. Furthermore, the sensing unit 102 can also transmit the result of the determination of the light reception level to the fire control signal 10. As a result, the effectiveness of the cleaning work can be confirmed simply and easily in a short time.

[0065] In actual operation using multiple photoelectric spot type sensors 130, in order to prevent the entire system from going unmonitored, it is possible to specify an address and put each photoelectric spot type sensor 130 into unmonitored mode one by one.

[0066] In addition, to prevent the non-monitoring mode from continuing even after the cleaning work has been completed, it is possible to switch to the monitoring mode after a certain period of time has passed, but to add a function that immediately returns to the monitoring mode after the cleaning work has been completed.

[0067] As described above, according to the first embodiment, the setting of the fire detector can be changed to an unmonitored state, and unmonitored control can be executed so that the detection result is not output. As a result, a fire detector with a simple function that can avoid false fire alarms caused by cleaning work can be realized. Furthermore, it is possible to avoid a situation where a false fire alarm is output from the fire detector, causing the terminal equipment group to erroneously operate in conjunction with each other. [Explanation of symbols]

[0068] 10 Fire receiver, 31, 41, 100 Fire detector, 101, 101a Mode setting unit, 102 Detection unit, 110 Flame detector, 111 Test light source, 112 Test light receiving element, 113 Light receiving window, 114 Confirmation light, 120 Photoelectric separated type detector, 121 Light transmitting unit, 122 Light receiving unit, 130 Photoelectric spot type detector, 131 Light emitting unit, 132 Light receiving unit.

Claims

1. A fire detector that is installed in a fire monitoring area and has a detection unit that detects the occurrence of a fire, The fire detector is a photoelectric separation type detector in which a light transmitting unit and a light receiving unit are arranged opposite each other, and detects the occurrence of a fire by detecting a decrease in the amount of light received by the light receiving unit when light emitted from the light transmitting unit is blocked, In order to prevent erroneous detection of a fire occurring during cleaning work, a mode setting unit is further provided which can switch between a monitoring mode and a non-monitoring mode, The sensing unit When the non-monitoring mode is set, non-monitoring control is performed in which the detection result is not output; a light receiving level at the light receiving unit immediately after switching from the monitoring mode to the non-monitoring mode is stored as a light receiving level before cleaning; In the non-monitoring mode, cleaning of the window of the light transmitting unit and the window of the light receiving unit is carried out as the cleaning work, and the light receiving level after the cleaning work is completed is compared with the light receiving level before cleaning, and the following formula is used: Light reception level before cleaning < Light reception level after cleaning If the above formula is satisfied, it is determined that the cleaning work has been carried out normally. Light reception level before cleaning ≥ Light reception level after cleaning If this is true, it is determined that the dirt on the window could not be completely removed or that the optical axis has shifted, making it impossible to monitor properly. fire detector.

2. the mode setting unit is configured with a magnetic switch that can be switched from an OFF state to an ON state by an external magnetic force, The sensing unit determines that the non-monitoring mode is in effect until a predetermined set time has elapsed since the magnet switch was switched to the ON state, and executes the non-monitoring control.

2. The fire detector of claim 1.

3. when receiving a non-monitoring mode setting command from a fire receiver that issues a fire alarm based on the detection results of a plurality of fire detectors, the mode setting unit sets the non-monitoring mode for a predetermined set time period from when the non-monitoring mode setting command is received, The sensing unit executes the unmonitored control when the unmonitored mode is set by the mode setting unit.

2. The fire detector of claim 1.

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