smoke sensor

Abstract

To provide a smoke detector capable of preventing an erroneous detection by preventing steam from flowing into a smoke detection unit.SOLUTION: In a smoke detector 1 comprising: a smoke detection unit 4 having a light emitting element and a light receiving element; and a smoke flow path 5 for conducting smoke into the smoke detection unit 4, in which smoke is detected by that the light receiving element receives light of the light emitting element scattered by the smoke conducted into the smoke detection unit 4, the smoke detector further comprises a Peltier element 7 for cooling and heating the smoke flow path 5; and the smoke detector is configured such that when the Peltier element 7 is controlled to a cooling side, a water content of the steam flowing into the smoke flow path 5 can be condensed or frozen, and when the Peltier element 7 is controlled to a heating side, the water produced by the condensation is evaporated, or the ice produced by the freezing is melted or evaporated after melting so that it can be discharged from the smoke flow path.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a smoke detector. [Background technology]

[0002] Conventionally, there have been smoke detectors. Smoke detectors have a smoke detection unit provided as a dark box, and a light-emitting element and a light-receiving element provided within the smoke detection unit. Smoke that has entered the smoke detection unit scatters the light from the light-emitting element, generating scattered light that is received by the light-receiving element, thereby detecting smoke. Such smoke detectors are primarily used as fire detectors, and are configured to sound a fire alarm when they detect smoke caused by a fire (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-168832 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the causes of false detection in smoke detectors is steam entering the smoke detector. Steam, like smoke, is a type of aerosol, and when steam enters the smoke detector, it scatters the light from the light-emitting element, just like smoke. The scattered light is then received by the light-receiving element, resulting in false detection.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a smoke detector that can prevent steam from entering the smoke detection section and prevent false detections. [Means for solving the problem]

[0006] The present invention relates to a smoke detector comprising a housing, an opening for taking smoke into the housing, a smoke detection unit having a light-emitting element and a light-receiving element, and a smoke flow path for introducing smoke into the smoke detection unit, and detecting smoke by the light-receiving element receiving light from the light-emitting element that is scattered by the smoke introduced into the smoke detection unit. The smoke detector further comprises a Peltier element for cooling and heating the smoke flow path, and the smoke flow path is provided with an inclined portion, and the Peltier element is disposed on the inclined portion. A water receiving portion is provided between the inclined portion and the opening, and the water receiving portion has a bottom on which the Peltier element is disposed. P A heater separate from the Peltier element is provided, and when the Peltier element is controlled to the cooling side, it is capable of condensing or freezing the water in the steam that has flowed into the smoke flow path, and when the Peltier element is controlled to the heating side, it is capable of evaporating the water that has been condensed, or melting or melting and then evaporating the ice that has been produced by the freezing, and discharging it from the smoke flow path. The water receiving section is provided to collect the water that has been produced by the condensation or melting and that has flowed down the inclined section, and the water that has collected in the water receiving section is heated by the heater, and the water that has flowed down the inclined section is discharged from the opening to the smoke flow path. feeling This smoke detector is characterized by the fact that the smoke is emitted outside the detector.

[0007] still , Book The invention can control the Peltier element to the cooling side when the ambient temperature of the smoke detector exceeds a predetermined value, and can control the Peltier element to the heating side when the ambient temperature falls below the predetermined value. Also, the invention can make it possible to arbitrarily control the Peltier element to the heating side. [Effects of the Invention]

[0008] The present invention provides a Peltier element for cooling and heating the smoke flow path, and when the Peltier element is controlled to the cooling side, it can condense or freeze steam that flows into the smoke flow path, and when the Peltier element is controlled to the heating side, it can evaporate the water produced by the condensation or melt the ice produced by the freezing, or melt and then evaporate it, and discharge it from the smoke flow path. This prevents steam from flowing into the smoke detector and prevents false detection. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a first embodiment of the present invention. [Figure 2] 1 is a schematic diagram of a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] A first embodiment of the present invention will be described with reference to Fig. 1. The smoke detector 1 includes a housing 2. The housing 2 is provided with an opening 3 for introducing smoke into the housing 2, and the housing 2 is provided with a smoke detection unit 4 and a smoke flow path 5 for introducing the smoke into the smoke detection unit 4.

[0011] The smoke detection unit 4 can be configured as appropriate to have the same structure as a known smoke detector, and is a dark box with a labyrinth formed around its periphery, inside which a light-emitting element (not shown) and a light-receiving element (not shown) are provided. In this embodiment, the light-receiving element is disposed in a position where it does not directly receive light from the light-emitting element, and smoke introduced into the smoke detection unit 4 scatters the light from the light-receiving element, generating scattered light that the light-receiving element receives, thereby enabling smoke detection. For example, a light-emitting diode can be used as the light-emitting element, and a photodiode can be used as the light-receiving element.

[0012] The smoke flow path 5 has an inclined portion 6 that slopes inward and upward, and a Peltier element 7 is disposed on the top surface of the inclined portion 6. In this embodiment, the smoke flow path 5 further has a folded portion 8 that extends from the tip of the inclined portion 6 to the smoke detection unit 4, and an insect screen 9 is attached to the folded portion 8 to prevent insects and other foreign objects from entering the smoke detection unit 4. The presence of the folded portion 8 prevents aerosols that are heavier than smoke, such as steam, from flowing into the smoke detection unit 4, and also allows the steam to remain in the inclined portion 6.

[0013] A groove-shaped water receiving portion 10 is provided between the opening 3 and the inclined portion 6. The water receiving portion 10 is provided to collect water derived from steam and prevent it from leaking out of the smoke detector 1 as a liquid, and in this embodiment, a heater 11 is provided at the bottom. The heater 11 is provided to evaporate the water collected in the water receiving portion 10 and release it as water vapor from the opening 3.

[0014] The Peltier element 7 is provided to cool and heat the smoke flow path 5, and is therefore connected to a power source (not shown) so that the polarity of the current flowing therethrough can be reversed. When controlled on the cooling side, the Peltier element 7 used has a cooling performance sufficient to freeze the water in the steam. In this embodiment, the Peltier element 7 used has a cooling performance sufficient to freeze the water in the steam.

[0015] As will be described later, the Peltier element 7 is controlled to the cooling side or the heating side based on the ambient temperature of the smoke detector 1. The temperature can be detected based on the electromotive force of the Peltier element 7. If the ambient temperature is measured by the smoke detector 1, the temperature can also be detected based on the detected value of the smoke detector 1.

[0016] When the ambient temperature of the smoke detector 1 exceeds a predetermined value, for example, a temperature at which the use of hot water in a shower or the like is suspected, the polarity of the current flowing through the Peltier element 7 is controlled so that the surface of the Peltier element 7 on the smoke flow path 5 side absorbs heat, i.e., so as to cool the smoke flow path 5. In this state, when steam flows into the smoke flow path 5 from the opening 3, the steam is cooled by the Peltier element 7 and the water condenses, and the condensed water freezes on the Peltier element 7. If there is water that does not freeze completely, it flows down the inclined portion 6 and accumulates in the water receiving portion 10.

[0017] In this case, it is preferable that a turning portion 8 is provided in the smoke flow path 5. By providing the turning portion 8, the steam, which is heavier than the smoke, will remain in the inclined portion 6, and the moisture in the steam can be more reliably condensed and frozen on the Peltier element 7.

[0018] Furthermore, if it is smoke that flows into the smoke flow path 5, unlike steam, smoke contains solid components such as soot, so even if it is cooled by the Peltier element 7, at least these solid components can pass through the smoke flow path 5 and flow into the smoke detection unit 4, and the light from the light-emitting element is scattered by the solid components that flow into the smoke detection unit 4, making it possible to detect smoke without any problems.

[0019] When the ambient temperature of the smoke detector 1 is below the predetermined value, i.e., when it is at a temperature at which it can be determined that hot water is not being used and steam is not being generated, the polarity of the current flowing through the Peltier element 7 is controlled so that the surface of the Peltier element 7 facing the smoke flow path 5 generates heat, i.e., so as to heat the smoke flow path 5, in the opposite manner to the above. As a result, the ice adhering to the surface of the Peltier element 7 melts due to the freezing, flows down the inclined portion 6, and accumulates in the water receiver 10. The water accumulated in the water receiver 10 is heated by the heater 11 and is released outside the smoke detector 1 through the opening 3.

[0020] At this time, the smoke detector 1 is designed to suspend smoke monitoring or not issue an alarm even if the light-receiving element receives the scattered light, to prevent false detections due to steam generated by heating the water with the Peltier element 7, etc. Also, if necessary, it is possible to set the device to issue a warning when the light-receiving element receives the scattered light. If a fire breaks out at this time, the ambient temperature will rise, so the Peltier element 7 will be controlled to the cooling side and will enter smoke monitoring mode.

[0021] Therefore, in this embodiment, even if steam flows into the smoke flow path 5, the water in the steam will be frozen by the Peltier element 7, preventing the steam from flowing into the smoke detection unit 4 and preventing the smoke detector 1 from making a false detection.

[0022] A second embodiment of the present invention will be described with reference to Fig. 2. The difference between this embodiment and the first embodiment is that the water content of the steam is not frozen on the Peltier element 7 but is instead condensed to form condensation. Components denoted by the same reference numerals as those in the first embodiment are the same as those in the first embodiment, and therefore will not be described here.

[0023] In this embodiment, Peltier elements 7 are disposed on both the top and bottom surfaces of the sloped portion 6 of the smoke flow path 5, and the Peltier elements 7 have at least the cooling performance to condense the water in the steam and the heating performance to evaporate the condensed water. In this embodiment, since the smoke flow path 5 does not have a folding portion 8, an insect screen 9 is attached to the opening 3.

[0024] In this embodiment, when steam flows into the smoke flow path 5 while the ambient temperature is above the predetermined value, the steam is cooled and condensed by the upper and lower Peltier elements 7, which are controlled to the cooling side, and condenses onto the Peltier elements 7. The condensation gradually flows down the inclined portion 6 and is drained into the water receiving portion 10. The water drained into the water receiving portion 10 is released outside the smoke detector 1 through the opening 3 by natural evaporation or the like.

[0025] Conversely, when the ambient temperature is below the predetermined value, the Peltier element 7 is controlled to the heating side, and the water remaining on the Peltier element 7 is heated and evaporated, and then released outside the smoke detector 1 through the opening 3.

[0026] Therefore, in this embodiment, even if steam flows into the smoke flow path 5, the moisture in the steam condenses and forms condensation due to the Peltier element 7, so that the steam can be prevented from flowing into the smoke detection unit 4, and false detection by the smoke detector 1 can be prevented.

[0027] Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment and can be modified as appropriate within the scope of the invention.

[0028] (1) In the first embodiment, when the Peltier element 7 is controlled to the heating side, water adhering to the Peltier element 7 may be evaporated and discharged, as in the second embodiment.

[0029] (2) The heater 11 and the folded portion 8 of the first embodiment can also be provided in the second embodiment.

[0030] (3) In the above embodiment, the Peltier element 7 is switched between the cooling side and the heating side depending on the ambient temperature of the smoke detector 1, but it is also possible to control the Peltier element 9 to the heating side at any timing. For example, if the smoke detector 1 is installed in a guest room of a lodging facility, it is possible to remove condensed water when a facility manager, such as a room cleaner, is in the room, and to constantly monitor for smoke when there are guests in the room.

[0031] (4) It is also possible to switch the Peltier element 7 between the cooling side and the heating side based on the humidity around the smoke detector 1. In this case, the Peltier element 7 is controlled to the cooling side when the humidity around the smoke detector 1 increases, and to the heating side when the humidity around the smoke detector 1 decreases.

[0032] (5) It is also possible to separately provide a thermometer or thermo-hygrometer for measuring the temperature around the smoke detector 1.

[0033] (6) In the above embodiment, the Peltier element 7 is used to directly cool or heat the smoke flow path 5. However, it is also possible to indirectly cool or heat the smoke flow path 5 by forming the wall surface of the smoke flow path 5 from a material with high thermal conductivity such as metal and cooling or heating the wall surface. [Explanation of symbols]

[0034] 1 smoke detector 2 housing 3 opening 4 Smoke detection section 5 Smoke flow path 6 Inclined section 7 Peltier element 8 Folded portion 9 Insect screen 10 water receiving portion 11 heater

Claims

1. The housing and an opening for introducing smoke into the enclosure; a smoke detection unit having a light emitting element and a light receiving element; a smoke flow path for introducing smoke into the smoke detection unit, In a smoke detector that detects smoke by having a light receiving element receive light from the light emitting element that is scattered by smoke introduced into the smoke detecting unit, a Peltier element for cooling and heating the smoke flow path; The smoke flow path is provided with an inclined portion, the Peltier element is disposed on the inclined portion, a water receiving portion is provided between the inclined portion and the opening, and a heater separate from the Peltier element is provided at the bottom of the water receiving portion; When the Peltier element is controlled to the cooling side, the water in the steam that has flowed into the smoke flow path can be condensed or frozen, and when the Peltier element is controlled to the heating side, the water produced by the condensation can be evaporated or the ice produced by the freezing can be melted or evaporated after melting and discharged from the smoke flow path. The water receiving section is provided to collect the water generated by the condensation or melting and that flows down the inclined section, and the water collected in the water receiving section is heated by the heater and released outside the smoke detector through the opening.

2. 2. The smoke detector according to claim 1, wherein the Peltier element is controlled to a cooling side when the ambient temperature of the smoke detector exceeds a predetermined value, and is controlled to a heating side when the ambient temperature falls below the predetermined value.

3. 3. The smoke detector according to claim 1, wherein the Peltier element can be controlled to a heating side as desired.

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