JP7408293B2 - smoke alarm - Google Patents

Description

The present invention relates to a smoke alarm with a built-in battery.

A conventional smoke alarm will be explained using the diagram of Patent Document 1. FIG. 3 is a schematic diagram showing a longitudinal section of the smoke alarm.
Reference numeral 100 denotes an alarm main body, and the distal end side of this main body is provided with a smoke detection section 101 having an opening through which outside air flows. The smoke detection unit 101 houses therein a light emitting element LD that emits light and a light receiving element PD that receives scattered light from the light emitting element LD, and the space inside the smoke detection unit 101 functions as a smoke detection space. .
The light emitting element LD and the light receiving element PD each have their lead terminals connected to a circuit board 102 built into the alarm main body 100, and are electrically connected to an arithmetic circuit mounted on the circuit board 102. Power is supplied to this circuit board 102 by a battery 103 provided in a battery case 104. This smoke detector has a speaker (not shown) that is driven by a battery 103, and issues a fire alarm from the speaker in the event of a fire, and is generally called a house alarm or a fire alarm.
In such an alarm, since the smoke detection section 101 protrudes from the alarm main body 100, the smoke flows smoothly into the smoke detection section 101 no matter which direction the smoke comes from in 360 degrees. However, in recent years, there has been a demand for thinner alarms, and alarms of a type in which the smoke detection portion does not protrude from the ceiling have been developed. This thin type smoke alarm will be explained using Patent Document 2.
FIG. 4 is a longitudinal cross-sectional view of the smoke alarm, in which a case 2 of the smoke alarm is attached to a ceiling 900, which is an installation surface, via a mounting base 1. This case 2 is composed of a back case 21 and a front case 22, and has a thin structure in which the smoke detection section 34 is provided inside the case 2 so that the smoke detection section does not protrude from the case 2.
FIG. 5 is a horizontal sectional view of the smoke alarm, taken at the middle of the back case 21 in the height direction. In FIG. 5, a pair of light emitting element and light receiving element are provided inside the smoke detection section 34. In the drawing, a battery case 616 containing a battery is provided above the smoke detection section.

Japanese Patent Application Publication No. 2010-271894 WO2017/073562 publication

Although such a thin smoke alarm is aesthetically pleasing due to its low height, it is inferior in smoke inflow characteristics to the type shown in FIG. 3 in which the smoke detection section protrudes. This is because the battery (battery case) and the smoke detection section are located on the same horizontal plane, making it difficult for smoke to flow into the detection section from the direction in which the battery case is arranged.
To explain in more detail, the battery case 616 is installed horizontally with respect to the smoke detection unit 34, so when smoke flows from the top to the bottom in the paper, the smoke hits the battery case and the smoke This becomes an obstacle that restricts the flow to the detection section. For this reason, in a thin smoke alarm, it is necessary to provide a plurality of smoke guiding members 632 and the like to improve the characteristics of smoke flowing into the smoke detection section, and the structure inside the main body becomes complicated.

It has a housing in which a smoke inlet for smoke inflow is formed on the side, and a smoke detection unit and a battery provided inside the housing and equipped with an optical element consisting of a pair of light emitting elements and a light receiving element. In a smoke alarm in which the detection part and the battery are arranged on a horizontal plane, there is a space between the optical element and the outer peripheral wall of the housing so that the optical axis of the optical element and the central axis in the longitudinal direction of the battery are almost parallel. The battery is disposed on the back side of the optical element so that the optical axis of the optical element and the central axis of the battery in the longitudinal direction coincide with each other .

According to the present invention, the battery is not placed horizontally in the housing of the smoke alarm with respect to the smoke detection unit, but the battery is arranged so that the central axis in the longitudinal direction of the battery and the optical axis of the optical element are almost parallel. was placed. Therefore, the flow of smoke regulated by the battery can be reduced compared to when the battery is placed horizontally. In particular, since the battery is placed on the back side of the optical element, which is a part where smoke inflow characteristics are poor, it is possible to minimize the poor smoke inflow characteristics due to the battery.

FIG. 1 is a longitudinal cross-sectional view of a smoke alarm according to an embodiment of the present invention. FIG. 1 is a horizontal cross-sectional view of a smoke alarm according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a vertical cross section of a conventional smoke alarm. FIG. 2 is a vertical cross-sectional view of a conventional thin smoke alarm. FIG. 1 is a horizontal cross-sectional view of a conventional thin smoke alarm.

A smoke alarm according to an embodiment of the present invention will be described using FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view of the smoke alarm, and FIG. 2 is a horizontal sectional view of the smoke alarm.
A housing 3 of the smoke alarm 1 is composed of a main body 5 and a protective cover 7. The main body 5 is approximately disk-shaped, and by attaching a bottomed cylindrical protective cover 7 to the main body 5, the casing 3 is configured as a thin cylindrical body with a low height. A smoke inlet 7C for inflowing smoke is formed on the side of the housing 3, that is, on the outer peripheral wall that constitutes the side wall of the protective cover 7. Incidentally, the main body 5 may be formed into a cylindrical shape with a bottom, and a smoke inlet may be formed in the outer peripheral wall of the main body 5. A main body 5 constituting the housing 3 is attached to the ceiling via a base 9.
Inside the housing 3, a smoke detection section, a battery, a circuit board, a speaker (not shown), and the like are provided. Here, the internal arrangement of batteries and the like will be explained using the horizontal sectional view of the smoke alarm shown in FIG. In addition, FIG. 2 is a diagram cut around the middle smoke inlet 7C among the three smoke alarms 1 shown in FIG.
The circular smoke detection section 11 is provided approximately at the center of the housing 3. The smoke detection unit 11 includes an optical element consisting of a pair of light emitting elements LED and a light receiving element PD. A plurality of J-shaped labyrinth members are formed around the optical element.
A space is provided between the smoke detection section 11 and the outer peripheral wall of the housing 3, and a battery 13 and a speaker (not shown) are provided on this space. Note that, as shown in FIG. 1, the smoke detection unit 11 and the battery 13 are arranged at the same position in the height direction, in other words, at the same position on the horizontal plane.
If a battery is installed horizontally with respect to the smoke detection unit in the space between the smoke detection unit 11 and the outer peripheral wall of the casing 3 as shown in the conventional example in FIG. In this embodiment, the battery 13 is installed vertically with respect to the smoke detection unit 11 because the flow is obstructed. Here, vertical placement refers to a placement that is perpendicular to horizontal placement, and is a placement where the longitudinal direction of the battery 13 does not face the smoke detection unit 11.
More specifically, the battery is placed in the space between the optical element (LED, PD) and the outer peripheral wall of the housing 3 so that the optical axis of the optical element and the central axis 13A in the longitudinal direction of the battery 13 coincide with each other. 13 is placed. Note that the optical axis of the optical element and the central axis in the longitudinal direction of the battery 13 do not have to be exactly aligned, and the battery may be arranged so that these axes are substantially parallel.

According to the present invention, the battery is not placed horizontally in the housing of the smoke alarm with respect to the smoke detection unit 11, but is arranged such that the central axis in the longitudinal direction of the battery 13 and the optical axis of the optical element almost coincide with each other. A battery 13 was placed. For this reason, even if smoke flows from the side where the battery 13 is located, the smoke will only hit the narrow lateral part of the battery, and will not obstruct the flow of smoke much. Therefore, the flow of smoke regulated by the battery 13 can be reduced compared to when the battery 13 is placed horizontally.
Note that it is sufficient that the number of batteries 13 is one, but when two batteries 13 are provided in the housing 3, one battery is placed on the back side of the light receiving element PD so that it is aligned with the optical axis of the light receiving element PD. The battery 13 is provided so that the longitudinal central axis 13A of the battery 13 coincides with the battery 13. It is preferable to arrange the other battery 13 on the back side of the light emitting element LED so that the optical axis of the light emitting element LED and the central axis 13A in the longitudinal direction of the battery 13 coincide with each other.

The battery 13 may be provided anywhere in the space between the smoke detection unit 11 and the outer circumferential wall of the housing 3 as long as it is placed vertically, but it is particularly desirable to place it on the back side of the optical element. This is because the smoke detection unit 11 does not have the same smoke inflow characteristics from any 360-degree direction, and in particular, smoke flows from the direction of the light-emitting part with the light-emitting element and the light-receiving part with the light-receiving element. This is because the inflow characteristics deteriorate. This is because in the smoke detection unit 13, the part where the light emitting part and the light receiving part are located is a part where the light emitting part and the light receiving part are blocked, and the shape makes it difficult for smoke to flow in compared to other surrounding parts. It is.
In this way, by arranging the battery 13 in a part where the smoke inflow characteristics are poor from the back side of the optical element, it is possible to minimize the deterioration of the smoke inflow characteristics due to the presence of the battery 13. . Therefore, there is no need to arrange a plurality of smoke introducing members in a complicated manner within the housing.

Note that when two batteries 13 are provided, the size of the batteries themselves can be reduced. In particular, if you use a battery whose width (length in the width direction) is the same as or smaller than the width of the light-emitting part or light-receiving part, it is possible to almost eliminate the restriction of smoke flow by the battery. Become.

Furthermore, when the batteries are arranged as in the present invention, depending on the size of the batteries, there is a possibility that the casing 3 itself becomes larger. Therefore, by increasing the number of batteries, the length of the batteries ( For example, three or more such batteries may be provided in the casing so that the casing itself does not become large. Although the battery is shown as it is, it may of course be installed in a battery storage case.

Further, since there is a part of space behind the light receiving part of the smoke detection part, the tip of the battery may be located in that space to prevent the casing from becoming larger.

As described above, by arranging the battery accommodating portion and the optical element, which are factors that deteriorate the smoke inflow characteristics, in the same direction, it is possible to stabilize the smoke inflow characteristics in all directions.

1 smoke alarm, 3 housing, 5 main body, 7 protective cover, 7C smoke inlet,
9 base, 11 smoke detection unit, 13 battery, 13A central axis,

Claims (2)

It has a casing in which a smoke inlet for smoke inflow is formed in a side part, and a smoke detection section and a battery provided in the casing and equipped with an optical element consisting of a pair of light emitting elements and a light receiving element, In a smoke alarm in which a smoke detection section and the battery are arranged on a horizontal plane, an optical axis of the optical element and a central axis in the longitudinal direction of the battery are arranged between the optical element and the outer peripheral wall of the housing. the batteries are arranged so that they are almost parallel;
A smoke alarm, characterized in that the battery is provided on the back side of the optical element so that the optical axis of the optical element and the central axis in the longitudinal direction of the battery coincide . Two of the batteries are provided in the housing, one battery is provided on the back side of the light-receiving element so that the optical axis of the light-receiving element and the central axis in the longitudinal direction of the battery coincide, and the other battery is provided on the back side of the light-emitting element. 2. The smoke alarm according to claim 1, wherein the light emitting element is provided on the back side thereof so that the optical axis of the light emitting element and the central axis in the longitudinal direction of the battery coincide with each other.

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