smoke sensor

Abstract

To provide a smoke detector capable of reducing bias in inflow performance of smoke into a smoke detection unit caused depending on an inflow direction.SOLUTION: A smoke detector 1 detects, by a smoke detecting unit 7, smoke flowing into a housing from an outside through flow ports, and comprises: flow path walls 10 forming smoke flow paths 11 between the flow ports and the smoke detecting unit 7, respectively, in the housing; and rectifying plates 12 which are objects each positioned within the smoke flow path 11, and lower than the flow path wall 10, and rectify flow of smoke flowing outward in the smoke paths 11 toward flow ports, or rectify flow of smoke flowing inward in the smoke paths 11 toward the smoke detecting unit 7.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Photoelectric smoke detectors are configured such that a light-receiving element receives scattered light within a smoke detection section into which smoke is introduced, and detects smoke based on the amount of light received. They are primarily used as fire detectors, and are installed on the ceilings or walls of buildings to be monitored. Specific examples include residential fire alarms and fire detectors for automatic fire alarm systems. Some residential fire alarms are configured as combined alarms that also detect gas leaks (such as city gas leaks) and CO (carbon monoxide).

[0003] Among these types of smoke detectors, there are some that have a flat, thin housing with no protruding portion for the smoke detector at the center of the front face of the housing. In such thin smoke detectors, the smoke detector is provided at an eccentric position in a plan view within the housing, and a flow path wall is provided around the smoke detector to form a smoke flow path that guides smoke from a smoke outlet on the outer periphery of the housing toward the smoke detector (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-226657 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the smoke detector is located at an eccentric position as described above, the smoke inflow performance into the smoke detector varies depending on the direction of inflow. This causes a problem of smoke detection sensitivity varying depending on the direction of inflow. For example, smoke from the side farther from the smoke detector on the outer periphery of the housing is less likely to flow to the smoke detector than smoke from the side closer to the smoke detector, resulting in a variation in smoke detection sensitivity depending on the direction of inflow.

[0006] SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a smoke detector that can reduce the bias in the performance of smoke flowing into the smoke detection section depending on the direction of flow. [Means for solving the problem]

[0007] This invention is a smoke detector that detects smoke flowing into a housing from the outside through a flow port by a smoke detection unit, wherein a flow path wall that forms a smoke flow path between the flow port and the smoke detection unit is provided in the housing, and is positioned within the smoke flow path, and the flow of smoke flowing outward within the smoke flow path is detected by the flow path wall. mouth a flow straightening plate having a height lower than the flow path wall, which straightens the flow of smoke flowing inward in the smoke flow path toward the smoke detecting unit, or straightens the flow of smoke flowing inward in the smoke flow path toward the smoke detecting unit. or a smoke detector that detects smoke flowing into a housing from the outside through a circulation port using a smoke detecting unit, wherein a flow path wall that forms a smoke flow path between the circulation port and the smoke detecting unit is provided within the housing, and a rectifying plate is provided within the smoke flow path to rectify the flow of smoke flowing outward in the smoke flow path toward the circulation port or to rectify the flow of smoke flowing inward in the smoke flow path toward the smoke detecting unit, the circulation port is provided on the outer periphery of the housing, the smoke detecting unit is provided inside the circulation port and at a position eccentric to the center of the housing in a plan view, and the rectifying plate is provided biased to the side where the distance between the smoke detecting unit and the circulation port is shorter. .

[0008] In this invention, the straightening vane may be oriented to extend along a straight line connecting the flow port and the smoke detector in a plan view. The flow port may be provided on the outer periphery of the housing, the smoke detector may be located inside the flow port and eccentrically relative to the center of the housing in a plan view, and the straightening vane may be located unevenly within the smoke flow path on the side where the distance between the smoke detector and the flow port is shorter. The straightening vane may also be located near the flow port. The flow port may be provided with a horizontal plate that divides the flow port in the height direction, and the height of the straightening vane may be approximately the same as the height at which the horizontal plate is provided. In addition, the housing has a middle plate portion on the front side where the smoke detection unit and the smoke flow path are arranged, and a circuit board on the rear side, and the circuit board is fixed by a fixing screw that passes through a position near the smoke detection unit on the middle plate portion with the head of the fixing screw positioned on the front side of the middle plate portion, and the head of the fixing screw can be positioned between the flow path wall and the smoke detection unit, or within the smoke flow path. [Effects of the Invention]

[0009] In this invention, when the straightening plate straightens the flow of smoke flowing outward within the smoke flow path toward the flow port, the straightening plate improves the flow of smoke within the smoke flow path on the smoke outflow side toward the flow port, making it easier for the smoke to flow from the flow port to the outside of the housing, thereby improving the overall flow of smoke and improving the flow of smoke within the smoke flow path on the smoke inflow side toward the smoke detector. Conversely, when the straightening plate straightens the flow of smoke flowing inward within the smoke flow path toward the smoke detector, if the straightening plate offers great resistance to the smoke flow, it may obstruct the flow of smoke toward the smoke detector. However, by making the straightening plate shorter in height than the flow path wall, the resistance of the straightening plate to the smoke flow can be reduced, preventing the flow of smoke toward the smoke detector from being adversely affected by the smoke detector. As a result, for example, even if the smoke detector is disposed in a position that causes a bias in the smoke inflow performance depending on the inflow direction, if the rectifying plate is disposed on the side where the smoke flow toward the smoke detector is good, when the rectifying plate rectifies the flow of smoke flowing outward within the smoke flow path toward the circulation port, the rectifying plate makes it easier for smoke to flow from the circulation port to the outside of the housing on the side where the smoke flow toward the smoke detector is good, thereby improving the flow of smoke toward the smoke detector on the side where the smoke flow toward the smoke detector is poor, thereby reducing the bias in the smoke inflow performance depending on the inflow direction.And while doing so, the resistance of the rectifying plate to the smoke flow can be reduced, so when the rectifying plate rectifies the flow of smoke flowing outward within the smoke flow path toward the circulation port, it is possible to prevent the rectifying plate from actually impairing the flow of smoke toward the smoke detector.

[0010] In addition, in this invention , the smoke detection department , provided at a position eccentric to the center of the housing in a plan view, The smoke inflow performance is biased depending on the inflow direction. In the case , rectifier plate The distance between the smoke detector and the outlet is short. The side with good smoke flow to the smoke detector unevenly distributed Established By making it When the straightening plate straightens the flow of smoke flowing outward in the smoke flow path toward the circulation port, the straightening plate makes it easier for smoke to flow out of the housing from the circulation port on the side where the flow of smoke to the smoke detector is good, The distance between the smoke detector and the outlet is long. The flow of smoke to the smoke detector can be improved on the side where the flow of smoke to the smoke detector is poor, thereby reducing the bias in smoke inflow performance due to the direction of inflow.

[0011] Therefore, according to the present invention, a smoke detector can be obtained that can reduce the bias in the performance of smoke flowing into the smoke detection section depending on the direction of flow. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a front perspective view of an entire smoke detector according to an embodiment of the present invention; FIG. [Figure 2] FIG. 2 is a perspective view of the front side of the housing body in the above example with the front cover removed. [Figure 3] FIG. 3 is an enlarged view of a main part of FIG. 2. [Figure 4] FIG. 2 is a plan view of the front side of the housing body in the example shown in FIG. [Figure 5] FIG. 2 is a side view of the entire sensor in the same example. [Figure 6] FIG. 2 is an exploded perspective view of the entire sensor of the above example. DETAILED DESCRIPTION OF THE INVENTION

[0013] An example of an embodiment of the present invention will be described below with reference to Figures 1 to 6, as a smoke detector 1 that can also detect CO. The smoke detector of the present invention can be used as a fire detector installed to monitor the interior of a building, etc., and specifically, can be used, for example, as a residential fire alarm (including a combined type having a function of detecting gas leaks, CO, etc.), a fire detector for an automatic fire alarm system, etc.

[0014] Here, terms such as "front" and "back" used to describe the present invention that indicate position and direction are in accordance with the position and direction when the smoke detector 1 is installed.

[0015] [Overall configuration] Smoke detector 1 has a housing 2 that is flat and thin overall, with no protruding portion for the smoke detector on the front, and is used as a combined residential fire alarm that can detect both smoke and CO. Housing 2 consists of main body 3 and front cover 4 attached to its front side. Main body 3 consists of base 5 and middle plate 6 attached to its front side. More specifically, front cover 4 is attached to the front side of middle plate 6 of main body 2.

[0016] A circuit board 9 on which a smoke detector 7 and a CO detector 8 are mounted is provided on the rear side of the middle plate 6 (see FIG. 6). When the middle plate 6 is attached to the base 5, the smoke detector 7 and the CO detector 8 are exposed from the rear side to the front side through through-holes provided in the middle plate 6, and are located in a space on the front side of the middle plate 6, where a smoke flow path 10 (described below) is formed between the middle plate 6 and the front cover 4 (see FIG. 6). A circulation port 4a through which smoke and CO flow in is provided on the outer periphery of the front cover 4 surrounding the space.

[0017] The smoke detector 7 is provided on the front surface of the middle plate 6, eccentrically positioned from the center in a plan view (see FIG. 4 ). This is provided so that a battery case and the like can be accommodated within the housing 2. A plurality of flow path walls 10 are provided around the smoke detector 7, standing in the height direction on the front surface of the middle plate 6. These flow path walls 10 form a plurality of smoke flow paths 11 between the smoke detector 7 and the smoke flow path 11, which guide smoke flowing into the housing 2 from the flow path 4a toward the smoke detector 7. The CO detector 8 is provided in another smoke flow path 11 near the smoke flow path 11 in which the smoke detector 7 is provided. The smoke detector 7 and the CO detector 8 detect smoke and CO that flow into the housing 2 through the flow path 4a and reach the housing 2 after flowing through the smoke flow path 11.

[0018] More specifically, in the illustrated example, the front cover 4 has a front wall 4b, a peripheral wall 4c, and multiple support columns 4d, and the front wall 4b is supported on the front end of the peripheral wall 4c by the multiple support columns 4d (see FIG. 5). The circulation port 4a is provided circumferentially between the front wall 4b and the front end of the peripheral wall 4c, and is partitioned vertically (front-rear) by the multiple support columns 4d and horizontally (circumferentially) by horizontal plates 4e provided between the support columns 4d (see FIG. 5). That is, the circulation port 4a is partitioned vertically and horizontally by the multiple support columns 4d and the multiple horizontal plates 4e. The circulation port 4a is provided between the front wall 4b and the peripheral wall 4c of the front cover 4, and is provided with a smoke detector 7, a CO detector 8, and multiple flow path walls 10 forming multiple smoke flow paths 11 inside (see FIG. 5). As a result, smoke and CO flowing in from the flow port 4a flows into the smoke flow path 11 on the inside.

[0019] The smoke detector 1 is attached to the ceiling, wall, etc. of the building to be monitored via a mounting base (not shown) to which the rear side of the housing 2 is attached, and when it detects smoke or CO exceeding a predetermined concentration occurring within the building to be monitored, it issues an alarm.

[0020] [Rectifier plate] Smoke detector 1 is installed in the smoke flow path 11, standing in the height direction on the front surface of middle plate 6, and is provided with a straightening plate 12 whose height (height of its top) is shorter than flow path wall 10, which straightens the flow of smoke flowing outward within smoke flow path 11 toward outlet 4a, or straightens the flow of smoke flowing inward within smoke flow path 11 toward smoke detector 7. Straightening plate 12 is installed in smoke flow path 11 on the side closer to peripheral wall 4c than smoke detector 7, which is installed eccentrically with respect to housing 2.

[0021] Here, smoke flows into the interior of the housing 2 from all directions around it through the flow ports 4a. Smoke that flows into the interior of the housing 2 from the flow ports 4a on either side flows inward through the smoke flow path 11 that is continuous with the flow port 4a and into the smoke detection unit 7. After passing through the smoke detection unit 7, the smoke that flows into the smoke detection unit 7 flows outward through the smoke flow path 11 on the opposite side from which it flowed, and then flows out of the housing 2 through the flow ports 4a that are continuous with the smoke flow path 11. Whether the rectifying plate 12 rectifies the flow of smoke flowing outward within the smoke flow path 11 toward the flow ports 4a or rectifies the flow of smoke flowing inward within the smoke flow path 11 toward the smoke detection unit 7 depends on the direction in which the smoke flows.

[0022] Effect of the rectifier plate In smoke detector 1, when rectifying plate 12 rectifies the flow of smoke flowing outward in smoke flow path 11 toward outlet 4a, rectifying plate 12 improves the flow of smoke toward outlet 4a in smoke flow path 11, which is the smoke outflow side, making it easier for the smoke to flow from outlet 4a to the outside of housing 2. This improves the overall flow of smoke, and improves the flow of smoke toward smoke detection unit 7 in smoke flow path 11, which is the smoke inflow side.

[0023] Conversely, when the rectifying plate 12 rectifies the flow of smoke flowing inward within the smoke flow path 11 toward the smoke detection unit 7, a rectifying effect toward the smoke detection unit 7 can be expected, but if the rectifying plate 12 offers great resistance to the flow of smoke, it may obstruct the flow of smoke toward the smoke detection unit 7. However, by making the height (height of the top) of the rectifying plate 12 lower than the flow path wall 10, it is possible to reduce resistance to the flow of smoke, and therefore it is possible to prevent the rectifying plate 12 from actually impeding the flow of smoke toward the smoke detection unit 7.

[0024] As a result, for example, if smoke detector 7 is provided at an eccentric position as in smoke detector 1, the smoke inflow performance into smoke detector 7 would normally be biased depending on the direction of inflow, but if rectifying plate 12 is provided in smoke flow path 11 on the side where smoke flow toward smoke detector 7 is good, rectifying plate 12 rectifies the flow of smoke flowing outward within smoke flow path 11 toward outlet 4a, and thereby rectifies the flow of smoke toward smoke detector 7 on the side where smoke flow toward smoke detector 7 is poor by making it easier for smoke to flow from outlet 4a to the outside of the housing on the side where smoke flow toward smoke detector 7 is good, thereby improving the flow of smoke toward smoke detector 7 on the side where smoke flow toward smoke detector 7 is poor, thereby reducing the bias in the smoke inflow performance into smoke detector 7 due to the direction of inflow. Furthermore, while achieving this, rectifying plate 12's resistance to the smoke flow can be reduced, and therefore, when rectifying plate 12 rectifies the flow of smoke flowing inward within smoke flow path 11 toward smoke detector 7, rectifying plate 12 can prevent the flow of smoke toward smoke detector 7 from being adversely affected by rectifying plate 12.

[0025] -Example of the placement of the air flow rectifier (uneven placement on the side with good flow to the smoke detector) The straightening plate 12 is located unevenly within the smoke flow path 11 on the side where the smoke detector 7 is eccentrically located, that is, on the side where the distance between the smoke detector 7 and the flow port 4a is shorter (see FIG. 4). In the example shown, the straightening plate 12 is located only within the smoke flow path 11 on the side where the distance between the smoke detector 7 and the flow port 4a is shorter. In the case of a device where the smoke detector 7 is located eccentrically, such as smoke detector 1, if the straightening plate 12 is not provided, the flow of smoke flowing in from the flow port 4a on the side where the distance to the smoke detector 7 is longer will be more turbulent than the flow of smoke flowing in from the flow port 4a on the side where the distance to the smoke detector 7 is shorter, since the length of the smoke flow path 11 is longer, which is not good. Therefore, the smoke inflow performance will be biased depending on the direction of inflow, but if the straightening plate 12 is installed in the smoke flow path 11 on the side where the flow of smoke to the smoke detection unit 7 is good (the side where the distance between the smoke detection unit 7 and the flow port 4a is short), the straightening plate 12 can improve the flow of smoke to the smoke detection unit 7 on the side where the flow of smoke to the smoke detection unit 7 is poor (the side where the distance between the smoke detection unit 7 and the flow port 4a is long), as described above, and the bias in the smoke inflow performance to the smoke detection unit 7 depending on the direction of inflow can be reduced.

[0026] -Specific examples of the shape of the rectifier plate ·Shape, arrangement, etc. The straightening plates 12 are provided with a shape, thickness, height, length, number, arrangement, etc. suitable for straightening the flow of smoke toward the outlet 4a or the smoke detector 7 while minimizing resistance to the smoke flow. For example, in the illustrated example, each straightening plate has a thin, flat shape and is located within the smoke flow path 11. In a plan view, the straightening plates are arranged radially with the flow path walls 10 and the like relative to the smoke detector 7, and are oriented to extend along a straight line connecting the smoke detector 7 and the outlet 4a (see FIG. 4). The thinner the thickness of the straightening plates 12 is than the flow path walls 10, the more effective they are; however, a thickness similar to that of the flow path walls 10 can also be sufficient. The straightening plates 12 have a height (height of their tops) shorter than the flow path walls 10. Details of the height will be explained further below. The length (the length between both ends of the smoke detector 7 and the outlet 4a) is also shorter than the length of the flow path walls 10. More specifically, each of the flow path walls 10 has a short length of approximately 1 / 2 or 1 / 3 the length of the adjacent flow path wall 10 (see FIG. 4). The number of the flow path walls 10 in each smoke flow path 11 may be one or more depending on the width of the smoke flow path 11. The flow path walls 10 are located close to the flow paths 4a in each smoke flow path 11, while being biased toward the smoke detection unit 7 and the flow paths 4a. This allows the flow path walls 12 to rectify the flow of smoke flowing outward in the smoke flow path 11 toward the flow paths 4a, thereby facilitating the flow of smoke from the flow paths 4a to the outside of the housing 2. Furthermore, the flow path walls 10 are spaced apart from adjacent flow path walls 12 and flow path walls 10, as well as support members 14 for antennas 13 (described later), in the circumferential direction (see FIG. 4). Furthermore, more specifically, the shape of the straightening plate 12 is such that both end faces in the lengthwise direction, which face the smoke detector 7 and the outlet 4a, respectively, and which face the direction of the smoke flow, are slightly inclined in a V-shape (see FIG. 3). This allows smoke to flow toward the smoke detector 7. The shape, thickness, height (including the relationship with the height of the horizontal plates of the outlet, which will be explained later), length, number, arrangement, etc. of the straightening plate 12 are not limited to those exemplified here, and may of course be changed as appropriate.

[0027] Relationship between the height of the straightening plate and the installation height of the side plate of the flow port In the illustrated example, the flow port 4a is divided into two sections, front and rear, at a midpoint in the height direction by a horizontal plate 4e on the outer periphery of the front cover 4 (see FIG. 5). The height (height of the top) of the flow rectifying plate 12 is approximately the same as the installation height of the horizontal plate 4e (see FIG. 5). If the flow rectifying plate 12 is provided in a position near the flow port 4a, the flow rectifying plate 12 may obstruct the inflow of smoke through the flow port 4a. However, if the height of the flow rectifying plate 12 is not only lower than the flow path wall 10 but also approximately the same as the installation height of the horizontal plate 4e, and the flow rectifying plate 11 is not positioned near the inside of the opening on the front side of the flow port 4a (the opening on the lower side when attached to the ceiling surface, i.e., the opening on the upper side in FIG. 5), the opening on the front side can be secured as an opening where the inflow of smoke is not obstructed by the flow rectifying plate 12.

[0028] [Antenna support member] The smoke detector 1 is configured such that an antenna 13 for wireless communication is provided within the housing 2 (see FIG. 3). The antenna 13 is supported circumferentially at a height above the flow port 4a by a support member 14 erected on the front surface of the middle plate portion 6. The support member 14 has a thin, flat plate shape and is positioned within the smoke flow path 11, oriented in the same direction as the flow rectifier plate 12 (see FIG. 4). In other words, it is expected to have a rectifying effect on the flow of smoke toward the flow port 4a or toward the smoke detector 7.

[0029] [Circuit board fixing screws] The circuit board 9 provided on the back side of the middle plate 6 is oriented with its head facing the front side of the middle plate 6 and is fixed by a fixing screw 15 which penetrates the middle plate 6 near the smoke detector 7, then penetrates the circuit board 9 and is screwed into a screw hole 16 provided in the base 5 (see FIG. 6). More specifically, the fixing position of the fixing screw 15 is provided near the smoke detector 7 on the side where the distance between the smoke detector 7 and the outer periphery of the front cover 4 is greater (see FIG. 4). When the smoke detector 7 is provided in an eccentric position, a large space is formed on the side where the distance to the outer periphery of the front cover 4 is greater, and therefore the middle plate 6 is prone to deformation (warping, bending, etc.) over time, etc. However, if the fixing position of the fixing screw 15 is located near the smoke detector 7 on the side where the distance between the smoke detector 7 and the outer periphery of the front cover 4 is longer, the side of the middle plate 6 where a large space is formed can be fixed with the fixing screw 15, and the middle plate 6 can be stably fixed to the base 5 together with the circuit board 9 while preventing deformation of the middle plate 6 due to aging, etc.

[0030] Furthermore, in the illustrated example, the fixing position of the fixing screw 15 is between the smoke detector 7 and the flow path wall 10, on an extension of the flow path wall 10 (see FIG. 4). That is, the position is such that the head of the fixing screw 15 does not obstruct the flow of smoke, and more specifically, the position is such that the head of the fixing screw 15, together with the flow path wall 10, can be expected to have a smoke flow guiding effect. Note that the fixing position of the fixing screw 15 may be a position within the smoke flow path 11 instead of on an extension of the flow path wall 10. That is, the position may be such that the head of the fixing screw 15 can have a smoke flow straightening effect. Note that the shape of the head of the fixing screw 15 can be a low-head type, such as a dish-shaped type, so as not to obstruct the flow of smoke, or a type that protrudes above the fixing surface, such as a pan-shaped type, if a smoke flow guiding effect or straightening effect is expected.

[0031] [Configuration change example] The embodiments of the present invention have been described above with reference to FIGS. 1 to 6. However, the specific configuration is not limited to the above-described embodiments, and design modifications and the like are also included within the scope of the gist of the present invention. [Explanation of symbols]

[0032] 1: Smoke detector 2: Housing 3: Main body 4: Front cover 4a: Ventilation port 4b: Front wall 4c: Peripheral wall 4d: Support column 4e: Horizontal plate 5: Base section 6: Middle plate section 7: Smoke detector section 8: CO detector section 9: Circuit board 10: Channel wall 11: Smoke channel 12: Rectifier plate 12a: Top 13: Antenna 14: Support member 15: Fixing screw 16: Screw hole

Claims

1. A smoke detector that detects smoke flowing into a housing from the outside through a flow port using a smoke detection unit, A smoke detector characterized in that a flow path wall is provided within the housing to form a smoke flow path between the circulation port and the smoke detection unit, and a straightening plate is provided within the smoke flow path and is shorter in height than the flow path wall to straighten the flow of smoke flowing outward within the smoke flow path toward the circulation port, or to straighten the flow of smoke flowing inward within the smoke flow path toward the smoke detection unit.

2. A smoke detector that detects smoke flowing into a housing from the outside through a circulation port using a smoke detection unit, A flow path wall is provided within the housing to form a smoke flow path between the flow port and the smoke detector, and a flow straightening plate is provided within the smoke flow path to straighten the flow of smoke flowing outward within the smoke flow path toward the flow port, or to straighten the flow of smoke flowing inward within the smoke flow path toward the smoke detector, A smoke detector characterized in that the circulation port is provided on the outer periphery of the housing, the smoke detection unit is located inside the circulation port and eccentrically relative to the center of the housing when viewed in a plane, and the straightening plate is located biased toward the side where the distance between the smoke detection unit and the circulation port is shorter.

3. 3. The smoke detector according to claim 1, wherein the rectifying plate is provided at a position near the flow port.

4. A smoke detector as described in any one of claims 1 to 3, characterized in that the flow port is provided with a horizontal plate that divides the flow port in the vertical direction, and the height of the straightening plate is approximately the same as the height at which the horizontal plate is provided.

5. A smoke detector as described in any one of claims 1 to 4, characterized in that the housing has a middle plate portion on the front side where the smoke detection unit and the smoke flow path are arranged, and a circuit board on the back side where the circuit board is arranged, the circuit board being fixed by a fixing screw that passes through a position near the smoke detection unit on the middle plate portion with its head positioned on the front side of the middle plate portion, and the head of the fixing screw being positioned between the flow path wall and the smoke detection unit or within the smoke flow path.

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