JP2883676B2 - Scattered light smoke detector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scattering type smoke detector, and more particularly, to a scattering type smoker which has a reduced overall shape and an improved smoke detection operation. The present invention relates to an optical smoke detector.

[Prior Art and Problems to be Solved by the Invention] Generally, a scattered light type smoke detector (hereinafter, simply referred to as a “smoke detector”) includes a light source that emits light and smoke from the light source as described later. A light-receiving unit for receiving light via the particles is arranged on a disk-shaped support, for example, and for this support,
A smoke detection member, also called a dark box, is attached, and light from the light source is applied to smoke particles that enter inside from a gap between side wall pieces of the smoke detection member, and reflected light is received by the light receiving unit. The presence of smoke is detected as an electrical signal.

By the way, in recent years, there has been an increasing demand for thinner smoke detectors, and in order to cope with this, attempts have been made to reduce the thickness of both the support and the smoke detection member. There are certain limitations on the relationship.

 For this reason, the main problem to be solved is to reduce the thickness of the smoke detection member.

FIG. 6 shows a conventional example in which such a smoke detecting member is made thinner.

The smoke detector 50 shown in FIG.
Attaching the 52 and the light receiving section 53 at a predetermined angle arrangement,
A substantially rectangular shaped side wall pieces 54 are arranged in a substantially circular arrangement around the periphery of the support body 51, and a gap 55 is formed between the side wall pieces 54 as a smoke flow path. The upper end of each side wall piece 54 is covered by a top plate (not shown), and the space surrounded by this top plate and each side wall piece 54 functions as a smoke detection space.

A so-called labyrinth structure is constituted by the side wall pieces 54 described above.

However, in the case of the smoke detector 50, since the gap 55 between the side wall pieces 54 is bent in a rectangular shape, the purpose of thinning the smoke detection space can be achieved to some extent.
Due to the shape of the smoke detector, the state of invasion of smoke into the smoke detection space is not always sufficient, and there is a problem that the smoke detection operation by the smoke detector 50 lacks certainty.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a smoke detector capable of reducing the thickness of a smoke detection member and improving the reliability of a smoke detection operation.

[Means for Solving the Problems] The present invention provides a support having a light source that emits light and a light receiving unit that is arranged so that light from the light source does not directly enter,
Scattered light smoke having a substantially cylindrical shape and a smoke detection member including a side wall group having a gap through which smoke can pass and a top plate closing a protruding end of the side wall group. In the sensor, the side wall piece group is arranged along the periphery of the top plate portion and in a state in which a gap is sandwiched inwardly, and is directed substantially in the direction of the center of the smoke detection member at the inner end portion. A peripheral side wall piece group having a bent portion, and a smoke branch flow path between each bent portion arranged in a row near each bent portion of each peripheral side wall piece in a direction crossing the bent portion. And a group of inner side walls that guide the light from the light source toward the branch flow path.

[Operation] According to the smoke detector having the above-described configuration, when light from the outside of the smoke detection member enters the gap that is a narrow interval as it reaches the inside between the peripheral side wall pieces, it is reflected by each peripheral side wall piece, It is absorbed and is prevented from entering the light receiving portion in the smoke detection member.

Further, the light from the light source or the light reflected from the light source and hitting the top plate portion hits each inner side wall piece and is reflected toward the branch flow path, so that the light is also prevented from entering the light receiving portion.

On the other hand, the smoke from the outside of the smoke detection member enters through the gap between the peripheral side wall pieces, is diverted by the inner side wall pieces, and is quickly led to the irradiation area of the light from the light source to be subjected to smoke detection.

[Example] Hereinafter, an example of the present invention will be described in detail.

The smoke detector 1 shown in FIG. 1 is in the form of a disk and closely adheres to the upper surface of the support 2 in FIG. And a smoke detection member 4 having a substantially cylindrical shape and a top plate portion 5 mounted in a state where the smoke detection member is mounted.

The support 2 is provided with first and second receiving holes 6 and 7 each having a substantially C shape, and a light source 8 for emitting light is provided in the first receiving hole 6. A light receiving unit 11 composed of a lens 9 and a photoelectric conversion element 10 is arranged in the housed light 7.

As shown in FIGS. 2 and 3,
It is formed in a substantially cylindrical shape having a relatively thin disk-shaped top plate portion 5 and a side habit piece group 12 integrated with the top plate portion 5.

As shown in FIG. 1 and FIG. 2, a reflecting portion 15 is provided at the center of the top plate portion 5 so as to protrude toward the support 2 in a generally conical shape by connecting a concave curved surface 16 as a whole. . The vertex 17 of the reflecting portion 15 corresponds to a substantially intermediate position between the light source 8 and the lens 9. Further, the concave curved surface 16 of the reflecting portion 15 is in a polished state.

As shown in FIGS. 2 and 3,
A peripheral wall piece group 12A composed of a number of peripheral side wall pieces 13 arranged in a row along the outer peripheral portion of the top plate portion 5, and a number of inner side wall pieces arranged in a circle inside each peripheral side wall piece 13
And an inner side wall piece group 12B composed of fourteen.

The peripheral side wall piece 13 is an outer side portion 13a along the periphery of the top plate portion 5.
A linear guide piece 13b, and a bent portion that is provided at an inner end of the guide piece 13b and that is directed substantially in the direction of the center of the top plate 5.
13c is integrally formed with the adjacent guide piece 13b.
The spaces between the guide pieces 13b are arranged in rows so that the distance between the guide pieces 13b becomes narrower toward the inside of the top plate 5, and a gap 19 is formed between the guide pieces 13b.

Further, each of the inner side wall pieces 14 has a small gap 20a between each of the bent portions 13c at a position between the adjacent bent portions 13c,
20b.

As shown in FIG. 3, the arrangement direction of each inner side wall piece 14 is such that the direction of the extension game crosses the guide piece 13b with one gap 20b therebetween, and the extension of the adjacent guide piece 13b is The direction intersects the inner side wall piece 14 via the other gap 20b.

The two gaps 20a and 20b form a branch flow path (shown by a dotted line in FIG. 3) R for smoke entering from the gap 19.

In FIG. 1, 18A is a lead wire for the light source 8 and 18B is a lead wire for the light source conversion element 10.

Next, the operation of the smoke detector 1 having the above configuration will be described mainly with respect to the operation of the smoke detection member 4 on light and the operation on smoke.

The smoke entering the gap 19 from the outside of the smoke detection member 4 reaches the branch flow path R formed by the inner side wall piece 14 as shown in FIG. 3, where it is divided into the gaps 20a and 20b and the concave shape is formed. Curved surface 16
The light source 8 and the light receiving unit 11 are used for smoke detection.

As a result, as compared with the conventional labyrinth structure, the intrusion state of the smoke is more reliable, and the reliability of the smoke detection operation can be improved.

Further, light entering the gap 19 from the outside of the smoke detection member 4 is, for example, a guide piece of the peripheral side wall piece 13 as shown in FIG.
13b, the adjacent guide piece 13b, the inner side wall piece 14, and the bent portion 13c are successively reflected and attenuated in this order. As a result,
Scattered light from the outside does not reach the light receiving area of the light receiving unit 11, and even if the dimension L of the side wall piece group 12 is reduced, there is no influence on the smoke sensing operation.

On the other hand, the light from the light source 8 is reflected by hitting the polished concave curved surface 16 of the reflecting portion 15, and at this time, the light hitting the concave curved surface 16 close to the light source 8 with the vertex 17 as a boundary is reflected by the concave curved surface 16.
Since the incident angle with respect to the light source 16 is relatively small, the reflected light almost returns to the light source 8 or its vicinity, and the inner side wall piece 14
And the bent portion 13c.

Light incident on the concave curved surface 16 close to the lens 9 at the vertex 17 has a relatively large incident angle on the concave curved surface 16 as shown in FIG. And hit the inner side wall piece 14 and the bent portion 13c.

In this way, the reflected light hitting the inner side wall piece 14 and the bent portion 13c is referred to as the adjacent inner side wall piece 14, the guide piece portion 13b, and the bent portion 13c as shown by the dotted line in FIG. As described above, the light is repeatedly reflected and guided to the gap 19 side, so that the light does not reach the light receiving area of the light receiving unit 11 and the smoke sensing operation is not affected even if the dimension L of the side wall piece group 12 is reduced. .

FIG. 5 shows another example of the embodiment of the present invention.
In the smoke detector 1A shown in the figure, those having the same functions as those shown in FIG. 1 are denoted by the same reference numerals, and the detailed description thereof will be omitted.

The difference between this smoke detector 1A and that shown in FIG.
That is, the reflecting portion 15 of the top plate portion 5 has a conical shape.

By adopting such a configuration, the same operation as in the case described above can be exerted.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

[Effects of the Invention] According to the present invention described in detail above, with the above configuration, any of the scattered light inside and outside the smoke detection member does not reach the light receiving region of the light receiving portion due to the action of the side wall piece group. Accordingly, the thickness of the smoke detection member can be reduced.

Further, since the branch flow path of the smoke is formed by the peripheral side wall group and the inner side wall group, the invasion of the smoke from the outside into the smoke detection member is performed promptly and without any trouble. In addition, the reliability of the smoke sensing operation can be improved.

[Brief description of the drawings]

1 is a longitudinal sectional view of a smoke detector according to an embodiment of the present invention, FIG. 2 is a partially cutaway sectional view of a smoke detecting member of the smoke detector, FIG. 3 is a bottom view of the same, and FIG. Explanatory drawing of the same light reflection operation,
FIG. 5 is a longitudinal sectional view of another embodiment of the present invention, and FIG. 6 is a schematic plan view of a conventional example. 1 ... smoke detector, 2 ... support, 4 ... smoke detection member, 5 ...
… Top plate part, 8… Light source, 11… Light receiving part, 15… Side wall piece group, 12A… Peripheral side wall piece group, 12B… Inner side wall piece group, 13…
… Surrounding side wall piece, 14 …… Inner side wall piece, 13c …… Bending part, 1
9, 20a, 20b ... gap.

Claims (1)

(57) [Claims] 1. A support having a light source for emitting light and a light receiving portion arranged so that light from the light source is not directly incident on the support.
Scattered light smoke having a substantially cylindrical shape and a smoke detection member including a side wall group having a gap through which smoke can pass and a top plate closing a protruding end of the side wall group. In the sensor, the side wall piece group is arranged along the periphery of the top plate portion and in a state in which a gap is sandwiched inwardly, and is directed substantially in the direction of the center of the smoke detection member at the inner end portion. A peripheral side wall piece group having a bent portion, and a smoke branch flow path between each bent portion arranged in a row near each bent portion of each peripheral side wall piece in a direction crossing the bent portion. And a group of inner side walls that guide the light from the light source toward the branch flow path.