Smoke sensor

Abstract

To provide a vertically mounted smoke detector that reduces foreign matter within the smoke detection section, making false detections due to foreign matter less likely. [Solution] The smoke detector 100 is a vertically mounted smoke detector installed on a wall 200, comprising a housing 1 provided with an opening 10 which is a smoke inlet, and a smoke detection unit 3 provided inside the housing 1, in which a smoke detection space for detecting smoke is formed, and an electrostatic member (electrostatic structure S) is arranged between the opening 10 and the entrance 31 of the smoke detection unit 3.

Description

[Technical Field]

[0001] The present invention relates to a vertically installed smoke detector installed on a wall. [Background Art]

[0002] Conventionally, some vertically installed smoke detectors installed on walls include a housing provided with an opening, and a smoke detection part in which a smoke detection space for detecting smoke is formed. Some of such smoke detectors are provided with a structure that adsorbs foreign matter such as dust (see, for example, Patent Document 1). [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2009-110433 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] However, in the smoke detector disclosed in Patent Document 1, the pocket portion provided in the smoke detection space in the smoke detection part is formed of a chargeable member to adsorb foreign matter, so foreign matter accumulates in the smoke detection space. Further, in the smoke detector disclosed in Patent Document 1, the smoke detection part is arranged so as to protrude forward from the opening on the front surface of the housing, and the outer peripheral portion of the smoke detection part serves as a smoke inflow port of the smoke detector. Therefore, dust and the like, which tends to accumulate particularly on the upper side of the smoke detector, easily enters the interior of the smoke detector through the smoke inflow port. When foreign matter enters and accumulates in the smoke detection part, false detection caused by the foreign matter occurs.

[0005] The present invention solves the above-described problems, and provides a vertically installed smoke detector that reduces foreign matter in a smoke detection part and is less prone to false detection caused by foreign matter. [Means for Solving the Problem]

[0006] The smoke detector according to the present invention is a vertically mounted smoke detector installed on a wall, comprising a housing provided with an opening which serves as a smoke inlet, and a smoke detection unit provided inside the housing, which has a smoke detection space formed inside where the smoke is detected, wherein an electrostatically charged member is arranged between the opening and the entrance to the smoke detection unit. [Effects of the Invention]

[0007] The smoke detector according to the present invention is a vertically mounted smoke detector installed on a wall, with a detection unit provided inside the housing and an electrostatically charged member positioned between the opening and the entrance to the smoke detection unit. This suppresses the entry of foreign matter into the smoke detection unit, making false detections due to foreign matter less likely. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic longitudinal cross-sectional view showing the internal configuration of the smoke detector according to Embodiment 1. [Figure 2] This is a schematic top view showing a smoke detector according to Embodiment 1. [Figure 3] This is a schematic longitudinal cross-sectional view showing the internal configuration of the smoke detector according to Embodiment 2. [Figure 4] This is a schematic top view showing a smoke detector according to Embodiment 2. [Figure 5] This is a schematic longitudinal cross-sectional view showing a modified example of the smoke detector shown in Figure 3. [Modes for carrying out the invention]

[0009] Embodiment 1. Hereinafter, embodiments of the smoke detector 100 according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below. Also, the size relationships of the components in the drawings may differ from those of the actual components. Furthermore, in the following description, terms indicating direction (e.g., "up," "down," "right," "left," "front," "back") will be used as appropriate to facilitate understanding, but these are for illustrative purposes only and do not limit the present invention. Also, in each figure, components with the same reference numerals are the same or equivalent components, and this is common throughout the entire specification.

[0010] Embodiment 1. Figure 1 is a schematic longitudinal cross-sectional view showing the internal structure of the smoke detector 100 according to Embodiment 1. Figure 2 is a schematic top view showing the smoke detector 100 according to Embodiment 1. In the figures, the white arrows indicate the flow of smoke. Based on Figures 1 and 2, the configuration of the smoke detector 100 of Embodiment 1 will be described.

[0011] The smoke detector 100 is installed in a monitoring space, such as inside a house, and constantly monitors the smoke concentration in the air, outputting an electrical signal or the like when the smoke concentration exceeds a certain value. The smoke detector 100 is a vertically mounted smoke detector that is attached to the wall 200 of a room.

[0012] As shown in Figures 1 and 2, the smoke detector 100 comprises a hollow housing 1 with an opening 10 that serves as a smoke inlet, and a detection mechanism 2 provided inside the housing 1 for detecting smoke in the air that flows into the housing 1 through the opening 10. The detection mechanism 2 includes a smoke detection unit 3 with a smoke detection space 30 formed inside into which smoke can flow, and a detection means 4 for detecting smoke in the smoke detection space 30. That is, the smoke detection space 30 is the space in which smoke is detected by the detection means 4. The detection means 4 consists of a light-emitting unit 4A and a light-receiving unit 4B and is mounted on a circuit board (not shown) provided inside the housing 1.

[0013] Furthermore, the smoke detector 100 has a chargeable structure S made of a chargeable material that suppresses the entry of foreign matter (e.g., dust and insects) into the smoke detection section 3. The chargeable structure S is positioned between the opening 10 and the entrance to the smoke detection section 3. The chargeable material is, for example, a chargeable resin. The specific configuration of the chargeable structure S will be described later.

[0014] The housing 1 has a rear panel 12 that is attached to the wall 200, a front panel 11 on the side opposite to the wall 200, and an outer peripheral surface 13 that connects the rear panel 12 and the front panel 11. In the examples in Figures 1 and 2, the outer peripheral surface 13 is cylindrical. The central part of the front panel 11 of the housing 1 is a circular opening 10, and the outer peripheral part of the front panel 11 is a tapered annular shape that slopes forward from the outer peripheral surface 13 towards the opening 10. The rear panel 12 is fixed to the wall 200 with screws or the like.

[0015] As shown in Figures 1 and 2, the opening 10, which is the smoke inlet for the smoke detector 100, is positioned so that the inside of the housing 1 cannot be seen through the opening 10 when the housing 1 is viewed from above while the smoke detector 100 is installed on the wall 200. In other words, the opening 10 is positioned so that it cannot be seen when the housing 1 is viewed from above (from the ceiling side). In Figure 1, as described above, the front surface 11 of the housing 1 has an opening 10 that is not visible from above but can be seen from the front.

[0016] The configuration of the housing 1 is not limited to the above configuration. For example, the front surface 11 may be a surface parallel to the rear surface 12. Also, for example, the shape of the housing 1 may be box-shaped. Furthermore, the housing 1 may be composed of multiple parts so that the rear surface 12 or the front surface 11 can be detached. Also, for example, the opening 10 may be provided on the lower side of the front surface 11 of the housing 1, extending from the front surface 11 to the lower front side of the housing 1.

[0017] The housing 1 may be formed of any material, but is generally formed of a flame-retardant resin (for example, ABS resin and ACS resin, etc.). The housing 1 may be formed of either a chargeable material or a non-chargeable material. The following description is given on the definition that the housing 1 is formed of a non-chargeable material (for example, ABS resin or ACS resin).

[0018] The smoke detection unit 3 is provided inside the housing 1. The smoke detection unit 3 includes a smoke detection unit wall 3w that partitions the space outside the smoke detection unit 3 inside the housing 1 and the internal smoke detection space 30. An inlet 31 leading to the smoke detection space 30 is provided on the smoke detection unit wall 3w. In the examples of FIG. 1 and FIG. 2, the inlet 31 leading to the smoke detection space 30 is provided on the front side of the smoke detection unit 3 facing the opening 10 of the housing 1. Further, a detection means 4 for detecting smoke in the smoke detection space 30 is installed on the smoke detection unit wall 3w.

[0019] The light-emitting unit 4A and the light-receiving unit 4B, which serve as the detection means 4, are mounted at predetermined respective positions on a substrate (not shown) such that their orientations are set to predetermined directions. The light-emitting unit 4A irradiates light into the smoke detection space 30, and the light-receiving unit 4B receives light irradiated from the light-emitting unit 4A and scattered in the smoke detection space 30. The light-emitting unit 4A is formed of, for example, an LED or the like. The detection means 4 irradiates light onto the air flowing into the smoke detection space 30, and detects smoke in the air by detecting the received scattered light. Although the scattered light method has been described here, smoke may also be detected by the extinction method.

[0020] The smoke detector 100 according to Embodiment 1 includes a mesh 7 that prevents foreign matter from entering through the opening 10. This mesh 7 is disposed between the opening 10 and the inlet 31 of the smoke detection unit 3, inside the opening 10, and is formed of a chargeable material. That is, in Embodiment 1, the mesh 7 disposed inside the opening 10 is the aforementioned chargeable structure S, which suppresses intrusion of foreign matter into the smoke detection unit 3 by adsorbing foreign matter such as dust and insects by Coulomb force.

[0021] As shown in FIG. 1 and FIG. 2, for example, the mesh 7 is in a flat plate shape, and is disposed in the opening 10 provided on the front face 11 of the housing 1, substantially parallel to the back face 12.

[0022] Note that the shape and arrangement of the mesh 7 are not limited to the above-described shape and arrangement, and may be appropriately set according to the position and orientation of the opening 10. A part of the mesh 7 may be made of a chargeable member, and for example, the chargeable member may be arranged concentrically or in a lattice shape.

[0023] <Operation of Smoke Detector 100> When smoke is generated in the monitored space, smoke-containing air flows into the housing 1 through the opening 10 on the front face 11. At this time, this air flows into the housing 1 through the mesh 7 formed of the chargeable member disposed inside the opening 10. The air that flows into the housing 1 through the mesh 7 flows into the smoke detection space 30 from the inlet 31 of the smoke detection unit 3. In the smoke detection unit 3, the detection means 4 irradiates light to the air that has flowed into the smoke detection space 30, and detects the received scattered light to detect smoke in the air. The smoke detector 100 outputs, as an electrical signal or the like, information that the smoke concentration in the air has reached or exceeded a predetermined value.

[0024] Note that when the smoke detector 100 is a type of smoke detector generally called a fire alarm equipped with a speaker, it may be configured such that the speaker notifies a user that the smoke concentration in the air has reached or exceeded a predetermined value.

[0025] <Effects of Chargeable Structure S> In the smoke detector 100 of the present invention, the chargeable structure S (in the first embodiment, the mesh 7) is disposed between the opening 10 and the inlet 31 of the smoke detection unit 3. This allows foreign matter to be adsorbed before the smoke detection unit 3, so that compared to the conventional case where the chargeable member is provided in the smoke detection space 30, the intrusion of foreign matter into the smoke detection space 30 is suppressed, and false detection is suppressed.

[0026] In the smoke detector 100 of Embodiment 1, the electrostatic structure S is a mesh 7 made of an electrostatic member, positioned between the opening 10 and the inlet 31 of the smoke detection section 3, and located inside the opening 10. In this case, foreign matter in the air attempting to enter the housing 1 through the opening 10 is prevented from passing through the periphery of the holes in the mesh 7 and is also attracted to the mesh 7 by Coulomb force. Therefore, the entry of foreign matter is prevented near the opening 10, making it difficult for foreign matter to reach the smoke detection section 3.

[0027] <Effects of restricting the position of opening 10> Furthermore, the opening 10, which is the smoke inlet of the smoke detector 100, is positioned so that the inside of the housing 1 cannot be seen from the opening 10 when the housing 1 is viewed from above (from the ceiling side), as shown in Figure 2. Specifically, the opening 10 is located in the center of the front surface 11 of the housing 1. In other words, the opening 10 is positioned so that it cannot be seen when the housing 1 is viewed from above. The smoke detection unit 3 is located inside the housing 1. Therefore, the entry of foreign matter into the housing 1 where the smoke detection unit 3 is located, through the opening 10 in the direction of gravity, is suppressed.

[0028] In general, with vertically mounted smoke detectors 100 installed on walls 200, dust and other foreign matter tend to accumulate on the part of the housing 1 that is visible from above. Therefore, in conventional configurations, where the smoke detection unit 3 is provided so as to protrude forward from the front surface 11 of the housing 1, and a smoke inlet is provided on the outer periphery of the smoke detection unit 3 together with an insect screen, clogging due to the accumulation of foreign matter is likely to occur in the upper part of the insect screen (i.e., the opening provided in a position visible from above). Consequently, conventional configurations cannot ensure airflow and may lead to false detections.

[0029] In contrast, in the smoke detector 100 of Embodiment 1, the opening 10, which serves as the smoke inlet, is located in a position that is not visible when the housing 1 is viewed from above (from the ceiling), the smoke detection unit 3 is located inside the housing 1, and a mesh 7 made of an electrostatically charged material is provided inside the opening 10. By restricting the position of the opening 10 to a location that is not visible from above (in Figures 1 and 2, the central part of the front surface 11), the amount of foreign matter entering the housing 1 is reduced, and any foreign matter that does enter the housing 1 is attracted by the mesh 7 made of an electrostatically charged material, further suppressing the entry of foreign matter into the smoke detection unit 3 and reducing false detections. Furthermore, since the mesh 7 is located inside the opening 10, which is not visible from above, the mesh 7 is not exposed from the opening 10 when the housing 1 is viewed from above. Therefore, even if foreign matter such as dust accumulated on the housing 1 moves downward along the front surface 11, it is difficult to touch the mesh 7 inside, minimizing the amount of foreign matter attracted to the mesh 7, suppressing clogging of the mesh 7, and ensuring airflow. As a result, the effect of improving smoke collection performance is further enhanced.

[0030] In other words, the smoke detector 100 of the present invention provides a synergistic effect between the positional restriction of the opening 10 and the electrostatic structure S arranged between the opening 10 and the inlet 31 of the smoke detection unit 3, resulting in the suppression of foreign matter intrusion and improved smoke collection performance.

[0031] As described above, the smoke detector 100 according to Embodiment 1 is a vertically mounted smoke detector installed on a wall 200. The smoke detector 100 comprises a housing 1 provided with an opening 10 which is a smoke inlet, and a smoke detection unit 3 provided inside the housing 1, in which a smoke detection space 30 in which smoke is detected is formed. In the smoke detector 100, an electrostatically charged member (electrostatically charged structure S) is arranged between the opening 10 and the inlet 31 of the smoke detection unit 3.

[0032] As described above, the smoke detector 100 according to Embodiment 1 is a vertically mounted smoke detector installed on a wall 200, with a smoke detection unit 3 provided inside the housing 1, and an electrostatically charged member positioned between the opening 10 and the entrance 31 of the smoke detection unit 3. This causes foreign matter that enters the housing 1 to be attracted by the electrostatically charged member before it reaches the smoke detection unit 3. Therefore, compared to conventional models, the entry of foreign matter into the smoke detection unit 3 is suppressed, and false detections due to foreign matter are less likely to occur.

[0033] Furthermore, the smoke detector 100 of Embodiment 1 is equipped with a mesh 7 to prevent foreign matter from entering through the opening 10. This mesh 7 is located between the opening 10 and the entrance 31 of the smoke detection section 3, and is positioned inside the opening 10, and is made of the electrostatically charged material described above. In other words, in the smoke detector 100 of Embodiment 1, the mesh 7 positioned inside the opening 10 is the electrostatically charged structure S described above.

[0034] As a result, any foreign matter that enters the housing 1 is attracted by the mesh 7 made of an electrostatic material, thus preventing foreign matter from entering the smoke detection unit 3, especially near the opening 10. Therefore, the arrival of foreign matter at the inlet 31 of the smoke detection unit 3 is also suppressed, making it particularly difficult for foreign matter to enter the smoke detection unit 3 and for false detections to occur as a result.

[0035] Furthermore, the opening 10 is positioned so that it is not visible when the housing 1 is viewed from above (from the ceiling). By restricting the position of the opening 10 to a location that is not visible from above, the amount of foreign matter entering the housing 1 can be reduced. In addition, if a mesh 7 made of the electrostatic material described above is placed inside such an opening 10, the mesh 7 will suppress the entry of foreign matter into the housing 1 and will also prevent foreign matter from remaining near the mesh 7 and the opening 10. Therefore, clogging is suppressed and airflow is ensured, which enhances the effect of improving smoke collection performance.

[0036] Embodiment 2. Figure 3 is a schematic longitudinal cross-sectional view showing the internal configuration of the smoke detector 100 according to Embodiment 2. Figure 4 is a schematic top view showing the smoke detector 100 according to Embodiment 2. In the figures, the white arrows indicate the flow of smoke. Based on Figures 3 and 4, the configuration of the smoke detector 100 of Embodiment 2 will be described.

[0037] The smoke detector 100 in Embodiment 2 is a vertically mounted smoke detector attached to a wall 200, similar to the one in Embodiment 1. The detection mechanism 2 is provided inside the housing 1 and is equipped with an electrostatic structure S. In Embodiment 2, the configuration of the electrostatic structure S mainly differs from that of Embodiment 1. The specific configuration of the electrostatic structure S will be described later.

[0038] The housing 1 has a rear panel 12 that is attached to the wall 200, a front panel 11 on the side opposite to the wall 200, and an outer peripheral surface 13 that connects the rear panel 12 and the front panel 11. In the examples in Figures 3 and 4, the housing 1 is box-shaped, and the outer peripheral surface 13 is composed of a top surface 14, a bottom surface 15, a left surface 16, and a right surface 17. The rear panel 12 is fixed to the wall 200 with screws or the like.

[0039] As shown in Figures 3 and 4, the opening 10, which is the smoke inlet for the smoke detector 100, is positioned so that it is not visible when the housing 1 is viewed from above (from the ceiling) while the smoke detector 100 is installed on the wall 200. In other words, the opening 10 is positioned so that the inside of the housing 1 cannot be seen through the opening 10 when the housing 1 is viewed from above. In Figure 3, the opening 10 is provided on the front 11 side of the housing 1, more specifically, on the lower side of the front 11 side of the housing 1, including the lower side of the front 11 and the front side of the bottom surface 15 of the housing 1.

[0040] The configuration of the housing 1 is not limited to the above configuration. For example, the shape of the housing 1 may be a cylindrical outer surface 13, as in the first embodiment. The housing 1 may also be composed of multiple parts so that the rear surface 12 or the front surface 11 is detachable. Alternatively, the housing 1 may be configured so that the top surface 14 or the bottom surface 15 is detachable. Furthermore, for example, the opening 10 may be formed only on the front surface 11 of the housing 1.

[0041] The enclosure 1 may be made of any material, but is generally made of flame-retardant resin (e.g., ABS resin and ACS resin). The enclosure 1 may be made of electrostatic or non-electrostatic material. In the following explanation, the enclosure 1 will be defined as being made of non-electrostatic material (e.g., ABS resin or ACS resin).

[0042] The smoke detection unit 3 is located inside the housing 1. The smoke detection unit 3 has a smoke detection wall 3w that separates the space outside the smoke detection unit 3 from the smoke detection space 30 inside the housing 1. The smoke detection wall 3w is provided with an inlet 31 to the smoke detection space 30. In the examples of Figures 3 and 4, the inlet 31 to the smoke detection space 30 is provided at the lower part of the smoke detection unit 3 facing the opening 10 of the housing 1. Furthermore, a detection means 4 for detecting smoke in the smoke detection space 30 is installed on the smoke detection wall 3w. The detection means 4 is the same as in the first embodiment.

[0043] The smoke detector 100 of Embodiment 2 is provided inside the housing 1 and includes a flow path section 6 that guides smoke entering through the opening 10 to the inlet 31 of the smoke detection section 3. The flow path section 6 forms an airflow path 60 inside the housing 1 from the opening 10 to the inlet 31 of the smoke detection section 3. In Embodiment 2, the flow path section 6 is made of an electrostatically charged material and is configured to attract foreign matter by Coulomb force. In other words, in Embodiment 2, the flow path section 6 is the electrostatically charged structure S described above that suppresses the entry of foreign matter into the smoke detection section 3.

[0044] In the example shown in Figure 3, the opening 10, which serves as the smoke inlet for the smoke detector 100, is located on the lower front side of the housing 1. The smoke detection unit 3 is positioned above and behind the opening 10 within the housing 1, and an inlet 31 for the smoke detection unit 3 is provided at the bottom of the smoke detection unit 3. The flow path section 6 constitutes a flow path 60 that guides smoke from the opening 10 of the housing 1 to the inlet 31 of the smoke detection unit 3, moving backward and upward. Specifically, the flow path section 6 is designed so that there is no downward section between the opening 10 and the inlet 31 of the smoke detection unit 3.

[0045] In the example shown in Figure 3, the portion of the flow path 6 on the side of the opening 10 (hereinafter referred to as the opening-side flow path 6a) and the portion on the side of the smoke detection unit 3 (hereinafter referred to as the smoke detection unit-side flow path 6c) constitute a horizontal flow path 60, while the portion connecting the opening-side flow path 6a and the smoke detection unit-side flow path 6c (hereinafter referred to as the connecting flow path 6b) constitutes a flow path 60 that is inclined rearward and upward. In the opening-side flow path 6a, the upper flow path wall 61 facing the lower opening of the opening 10 is provided horizontally, and in the smoke detection unit-side flow path 6c, the lower flow path wall 62 facing the inlet 31 of the smoke detection unit 3 is provided horizontally.

[0046] The shape of the flow path section 6 is not limited to the shape described above. It can be set appropriately depending on the positional relationship between the opening 10 and the smoke detection section 3.

[0047] Incidentally, the narrower the channel width W of the channel section 6, the easier it is for foreign matter passing through the channel 60 to come into contact with the charged wall surface. The channel width W is the length of the shortest diameter in the cross-section of the channel. From the viewpoint of balancing the effect of adsorption and ensuring airflow, it is preferable that the channel width W is about 4 mm. Alternatively, as shown in Figure 3, a narrowed section 6n may be provided in a part of the channel section 6 in which the channel width W is narrowed, and the channel width W of this narrowed section 6n may be about 4 mm. In the example in Figure 3, the connecting channel section 6b between the opening-side channel section 6a and the smoke detection section-side channel section 6c is the narrowed section 6n.

[0048] <Operation of smoke detector 100> When smoke is generated in the monitoring space, the smoke-containing air flows into the housing 1 through the opening 10 and into the smoke detection space 30 through the flow path 60 and the inlet 31 of the smoke detection unit 3. In the smoke detection unit 3, the detection means 4 irradiates light onto the air flowing into the smoke detection space 30 and detects the scattered light received to detect smoke in the air. The smoke detector 100 outputs an electrical signal or the like when the smoke concentration in the air exceeds a certain value.

[0049] <Effects of the electrostatic structure S (channel section 6)> In Embodiment 2, since the flow channel section 6 provided inside the housing 1 is made of an electrostatically charged material, foreign matter in the air that enters the housing 1 through the opening 10 is attracted to the wall surface of the flow channel section 6 as it passes through the flow channel 60. Therefore, as in Embodiment 1, foreign matter is attracted before it reaches the smoke detection section 3, so compared to the conventional case where an electrostatically charged material is provided in the smoke detection space 30, the intrusion of foreign matter into the smoke detection space 30 is suppressed, and false detections are suppressed.

[0050] Furthermore, the flow path 60 from the opening 10 to the inlet 31 of the smoke detection unit 3 is a space formed by the flow path section 6 provided inside the housing 1. Therefore, compared to a configuration where smoke flows into the smoke detection space 30 through the space inside the housing 1 without the flow path section 6, the flow path 6 is narrower, the distance between foreign matter and the wall surface is shorter, and foreign matter is more likely to come into contact with the wall surface. Consequently, foreign matter is more easily adsorbed onto the wall surface of the flow path section 6, and the amount of foreign matter in the air heading towards the smoke detection unit 3 can be reduced.

[0051] Furthermore, as explained using Figure 3, by not providing a downward-sloping section in the flow path 60, or by making the flow path 60 on the opening 10 or the smoke detection section 3 side horizontal, the following effects can also be expected. That is, assuming smoke gradually accumulates from the ceiling surface, i.e., the upper side, of the room which is the monitoring space, the above configuration of the flow path 60 makes it less likely for the inflow of air from the opening 10 or the inflow of air from the inlet 31 into the smoke detection space 30 to be obstructed.

[0052] <Effects of restricting the position of opening 10> Furthermore, the opening 10, which is the smoke inlet of the smoke detector 100, is positioned so that the inside of the housing 1 cannot be seen from the opening 10 when the housing 1 is viewed from above, as shown in Figure 4. Specifically, the opening 10 is provided on a surface other than the top surface 14 of the housing 1. In other words, the opening 10 is positioned so that it is not visible when the housing 1 is viewed from above. The smoke detection unit 3 is located inside the housing 1. Therefore, the entry of foreign matter into the flow path 60 from the opening 10 in the direction of gravity is suppressed.

[0053] If the opening 10 is located in a position visible from above, such as the top surface 14 of the housing 1, foreign matter that should accumulate on the top surface 14 may accumulate in the flow path 60 or the smoke detection section 3, or foreign matter accumulated on the edge of the opening 10 on the top surface 14 may fall into the flow path 60 due to airflow. In that case, there is a concern that the inlet 31 of the flow path 60 or the smoke detection section 3 may be blocked by the foreign matter. Furthermore, if the foreign matter that has entered the housing 1 in this way further enters the smoke detection space 30, or blocks the inlet 31 of the smoke detection section 3 and obstructs the inflow of smoke (i.e., airflow), there is a possibility of false detection.

[0054] For example, even if the smoke detection unit 3 is placed inside the housing 1 and the opening 10 of the housing 1 and the inlet 31 are connected by a flow channel 6, if the opening 10 is provided on the outer peripheral surface 13 including the top surface 14 of the housing 1, foreign matter will easily fall into the flow channel 6 due to gravity and reach the smoke detection unit 3. In such a case, even if the flow channel 6 is made of an electrostatically charged material, it will be difficult to retain foreign matter falling into the flow channel 6 due to gravity, and the adsorption effect due to Coulomb force by the electrostatically charged walls will not be fully realized.

[0055] In contrast, the smoke detector 100 of the present invention restricts the position of the opening 10, which is the smoke inlet, as described above. This reduces the amount of foreign matter entering the flow path 60 and prevents foreign matter from falling through the flow path 60 in the direction of gravity and penetrating deep inside. Reducing the amount of foreign matter entering the flow path 60, that is, suppressing the entry of foreign matter into the flow path 60 itself, prevents foreign matter from entering the smoke detection space 30. Furthermore, reducing the amount of foreign matter entering the flow path 60 suppresses the reduction in the flow path area due to foreign matter, thus preventing foreign matter in the flow path 60 from obstructing the flow of smoke into the smoke detection space 30. Foreign matter that enters the flow path 60 through the opening 10 provided on a surface other than the top surface 14 of the housing 1 is effectively attracted by the flow path section 6, which is made of an electrostatically charged material.

[0056] In other words, the smoke detector 100 of the present invention provides a synergistic effect between the positional restriction of the opening 10 and the electrostatic structure S arranged between the opening 10 and the inlet 31 of the smoke detection unit 3, resulting in the suppression of foreign matter intrusion and improved smoke collection performance.

[0057] Furthermore, while the opening 10 can be provided on any surface other than the top surface 14 of the housing 1, if we consider smoke gradually accumulating from the ceiling surface, i.e., from above, of the room which is the monitoring space, providing the opening 10 on at least a portion of the sides (front 11, back 12, right side 17, and left side 16) rather than only on the bottom surface 15 of the housing 1 will enable smoke detection at an earlier stage. Also, since the back surface 12 is located on the wall 200 side, it is preferable from the viewpoint of improving smoke collection performance that the opening 10 be provided on at least a portion of the sides other than the back surface 12 (front 11, right side 17, and left side 16).

[0058] <Variation> Figure 5 is a schematic longitudinal cross-sectional view showing a modified example of the smoke detector 100 in Figure 3. Here, the smoke detector 100 is defined as one installed in a highly airtight building (e.g., a house) where 24-hour air conditioning is provided. The housing 1 of the smoke detector 100 is provided with an opening 10 (smoke inlet) and a smoke outlet 19. The wall 200 to which the smoke detector 100 is attached is provided with a hole 201 (hereinafter also referred to as a wall smoke outlet) that connects the outdoors and the indoors (i.e., the monitoring space) at a position opposite the smoke outlet 19. The wall 200 is, for example, a partition wall made by sandwiching wood or the like between gypsum boards, and in this case, the space inside the partition wall, i.e., the space sandwiched between gypsum boards, is the outdoors as described above.

[0059] In the smoke detector 100 shown in Figure 5, as in the examples in Figures 3 and 4, the opening 10, which is the smoke inlet, is provided in such a way that the inside of the housing 1 cannot be seen through the opening 10 when the housing 1 is viewed from above. In the smoke detector 100 of Figure 5, the opening 10, which is the smoke inlet, is provided on the front 11 side of the housing 1, and the smoke outlet 19 is provided on the rear 12 side of the housing 1.

[0060] When a smoke detector 100 is installed in a highly airtight building, smoke from inside the building flows into the housing 1 through the opening 10, moves within the housing 1 from the opening 10 towards the smoke outlet 19, and then flows out to the outside through the smoke outlet 19. Within the housing 1, the smoke is detected as it passes through the smoke detection space 30 as it moves from the opening 10 towards the smoke outlet 19. In this way, when a smoke detector 100 with an opening 10 (smoke inlet) and a smoke outlet 19 is installed in a highly airtight building, an improvement in inflow characteristics can be expected due to the difference between the internal and external pressure, i.e., the differential pressure between the inside and outside.

[0061] Note that the wall 200 is not limited to the partition wall described above. Also, since buildings generally have a configuration that allows air to pass between the interior and exterior, even if the wall 200 does not have a hole 201, the effect of improving the inflow characteristics described above can be obtained if the smoke detector 100 is provided with a smoke outlet hole 19.

[0062] As described above, the smoke detector 100 according to Embodiment 2 is a vertically mounted smoke detector installed on a wall 200, similar to Embodiment 1. The smoke detector 100 comprises a housing 1 provided with an opening 10 which is a smoke inlet, and a smoke detection unit 3 provided inside the housing, with a smoke detection space 30 formed inside where smoke is detected. In the smoke detector 100, an electrostatically charged member (electrostatically charged structure S) is arranged between the opening 10 and the inlet 31 of the smoke detection unit 3.

[0063] Furthermore, the smoke detector 100 of Embodiment 2 is located inside the housing 1 and includes a flow path section 6 that guides smoke flowing in from the opening 10 to the inlet 31 of the smoke detection section 3. The flow path section 6 is made of the electrostatic material described above. In other words, in Embodiment 2, the flow path section 6 is an electrostatic structure S located between the opening 10 and the inlet 31 of the smoke detection section 3.

[0064] As a result, a flow path 60 is formed by the flow path section 6 located inside the housing 1. Compared to a configuration where smoke flows into the smoke detection space 30 through the space inside the housing 1 without a flow path section 6, a narrower flow path 60 can be formed, making it easier for foreign matter to come into contact with the electrostatically charged wall surface. Therefore, foreign matter is more easily adsorbed onto the wall surface of the flow path section 6, effectively reducing foreign matter in the air heading towards the smoke detection section 3.

[0065] Furthermore, the opening 10 may be positioned so that it is not visible when the housing 1 is viewed from above (from the ceiling). By restricting the position of the opening 10 to a position that is not visible from above, the amount of foreign matter entering the housing 1 can be reduced. In addition, if the flow channel 6, which is made of the electrostatic material described above, is provided inside the housing 1 with such an opening 10, the amount of foreign matter entering the housing 1 itself can be reduced by restricting the position of the opening 10. Therefore, even in a configuration where foreign matter is adsorbed onto the flow channel 6 to suppress its entry into the smoke detection unit 3, the amount of foreign matter in the flow channel 6 can be reduced, and airflow can be ensured, thus enhancing the effect of improving smoke collection performance.

[0066] Alternatively, the wall 200 may be provided with a wall-mounted smoke outlet (hole 201) for releasing smoke to the outside, and the smoke detector 100 (see Figure 5) may be configured such that the housing 1 is equipped with a smoke outlet 19 located opposite the wall-mounted smoke outlet (hole 201), and the smoke moves from the opening 10 towards the smoke outlet 19 and the wall-mounted smoke outlet.

[0067] In this way, by providing a smoke outlet 19 in the housing 1 in addition to the opening 10 which is the smoke inlet, the smoke inflow characteristics are improved, especially when the smoke detector 100 is installed in a highly airtight house where 24-hour air conditioning is in place.

[0068] The shape of the housing 1, the position of the opening 10 in the housing 1, and the position of the inlet 31 in the smoke detection section 3 are not limited to the shapes and positions described above. In the housing 1, it is preferable that the opening 10 is provided in such a way that the inside of the housing 1 cannot be seen through the opening 10 when the housing 1 is viewed from above, as shown in Figure 2. Although not shown, a labyrinth wall with a light-shielding function may be provided at the inlet 31 of the smoke detection section 3. The labyrinth wall is composed of a bent plate-shaped member.

[0069] In Embodiment 2, although it was defined and explained that a flow channel section 6 is provided instead of the mesh 7 (see Figure 1) of Embodiment 1, both the flow channel section 6 and the mesh 7 may be provided. Furthermore, when both the flow channel section 6 and the mesh 7 are provided, it is sufficient that one of the flow channel section 6 and the mesh 7 is made of an electrostatically charged material, while the other is made of a non-electrostatically charged material. [Explanation of symbols]

[0070] 1 Housing, 2 Detection mechanism, 3 Smoke detection section, 3w Smoke detection section wall, 4 Detection means, 4A Light-emitting section, 4B Light-receiving section, 6 Flow path section, 6a Opening-side flow path section, 6b Connecting flow path section, 6c Smoke detection section-side flow path section, 6n Reducing section, 7 Mesh, 10 Opening, 11 Front, 12 Back, 13 Outer surface, 14 Top, 15 Bottom, 16 Left side, 17 Right side, 19 Smoke outlet hole, 30 Smoke detection space, 31 Inlet, 60 Flow path, 61 Flow path wall, 62 Flow path wall, 100 Smoke detector, 200 Wall, 201 Hole, S Electrostatic structure, W Flow path width.

Claims

1. A vertically mounted smoke detector that is installed on a wall, A housing with an opening that serves as a smoke inlet, The system includes a smoke detection unit provided within the housing, which has a smoke detection space formed inside where the smoke is detected, A chargeable member is positioned between the opening and the entrance to the smoke detection section. Smoke detector.

2. The opening is equipped with a mesh to prevent foreign objects from entering, The mesh is located between the opening and the entrance of the smoke detection section, and is positioned inside the opening, and is made of the electrostatic member, The smoke detector according to claim 1.

3. The enclosure is equipped with a flow path section that guides the smoke flowing in from the opening to the inlet of the smoke detection section, The flow channel portion is composed of the electrostatic member, The smoke detector according to claim 1.

4. The aforementioned opening is located in a position that is not visible when the housing is viewed from above. The smoke detector according to claim 1.

5. The aforementioned wall is provided with a wall-surface smoke outlet for releasing the smoke to the outside. The housing is provided with a smoke outlet located opposite the wall smoke outlet, The smoke moves from the opening toward the smoke outlet and the wall smoke outlet. A smoke detector according to any one of claims 1 to 4.

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