JP5154528B2 - Photoelectric smoke detector - Google Patents

Description

  The present invention relates to a photoelectric smoke detector that detects smoke by detecting scattered light of light emitted from a light emitter with a light receiver.

For example, as described in Patent Document 1, the photoelectric smoke detector includes a labyrinth structure that allows inflow of smoke from the outside, blocks light from outside, and attenuates internal stray light. And a light emitter that emits light toward the smoke detection space formed by being surrounded by the labyrinth structure, and a light receiver that receives light scattered by the smoke particles in the smoke detection space. .
In addition, an insect net is installed on the outside of the labyrinth structure in order to prevent foreign matters such as insects from entering and generating false alarms.

Although the labyrinth structure needs to reliably block the incidence of external light, it is desirable that the smoke enters as smoothly as possible. In addition, the insect net that covers the outer periphery of the labyrinth structure also effectively prevents foreign substances such as insects from entering, but it is desirable that the smoke enters as smoothly as possible.
However, since the conventional insect screen is formed by a punching metal in which a large number of small holes are formed in a thin metal plate, the amount of smoke flowing along the peripheral surface and flowing into the insect screen is small. There is a problem of poor responsiveness.
Therefore, Patent Document 1 employs a configuration in which a blocking plate that blocks the flow of smoke along the insect screen and guides it to the labyrinth structure is provided outside the insect screen.

JP 2009-199518 A

  However, in the structure in which the shielding plate is provided outside the insect screen, the smoke blocked by the shielding plate is not necessarily guided to the labyrinth structure side. On the other hand, the presence of the shielding plate inhibits the flow along the insect screen after the shielding plate, so that the smoke does not travel all around the smoke detector, and as a result, the amount of smoke flowing into the labyrinth structure is reduced. On the contrary, it may be possible to deteriorate the responsiveness of the sensor.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a photoelectric smoke detector that is smooth in the flow of smoke from the outside and excellent in responsiveness.

In order to achieve the above object, it is necessary to make it possible for the smoke to flow smoothly both in the insect screen and in the labyrinth structure disposed inside thereof.
The inventor examined the labyrinth structure, and the labyrinth structure that has already been devised has various shapes for the constituent members, all of which are installed with the labyrinth structure member fixed. This is based on the idea of smoothing inflow of smoke and blocking light by devising the shape of the constituent members on the premise of doing so.
However, it has been found that there is a limit to smooth inflow of smoke simply by fixing the labyrinth structure and devising the shape of the constituent members constituting it.
Therefore, the inventor removes the fixed idea that such a labyrinth structure is fixed and installs the labyrinth structure so that it can freely rotate. We thought that the smoke could be actively guided into the labyrinth structure by rotation.

Insect repellent nets also conventionally use punching metal, and Patent Document 1 also attempts to allow smoke to flow in by adding a blocking plate on the premise of punching metal.
However, in a shape like punching metal, smoke flows so as to lick its peripheral surface, and it is difficult for it to actively flow into the inside. It may be disadvantageous from the viewpoint of inflow.
Therefore, the inventor does not have a shape like a punching metal, but in order to allow smooth air inflow with less air resistance, a thin donut-like plate is laminated through a minute gap that does not allow insects to enter. I thought of a new configuration.

  The present invention is based on a completely different idea from the prior art, and specifically comprises the following configuration.

(1) A photoelectric smoke detector according to the present invention is formed by a labyrinth structure that allows inflow of smoke from the outside and blocks light from outside to form a smoke detection space, and the labyrinth structure. A photoelectric smoke detector comprising: a light emitter that emits light toward the smoke detection space; and a light receiver that receives light scattered from the light emitter by smoke particles in the smoke detection space.
The labyrinth structure is installed rotatably.

(2) Further, in the above-described (1), the labyrinth structure is formed by arranging a plurality of labyrinth members having a substantially square cross section on the same circumference at regular intervals, It is characterized in that it is rotatably installed by providing a rotating shaft supported by a bearing at its center.

(3) In the above (2), the rotation shaft is supported by a light shielding column installed in the smoke detection space.

(4) Further, in any of the above (1) to (3), an insect repellent member provided along the outer peripheral portion of the labyrinth structure is provided, and the insect repellent member has a flat plate, a minute It is characterized by being laminated by a gap.

In the present invention, since the labyrinth structure is rotatably installed, the labyrinth structure is rotated by the air flow in the event of a fire, and the smoke is guided into the labyrinth structure. A sensitive smoke detector can be realized.
In addition, since the insect repellent member is laminated through a minute gap and the aperture ratio is increased, the outside air easily flows in and the responsiveness to smoke is improved.

It is explanatory drawing of the external appearance of the photoelectric smoke detector which concerns on one embodiment of this invention. It is explanatory drawing of the internal structure of the photoelectric smoke detector which concerns on one embodiment of this invention. It is explanatory drawing of the labyrinth structure installed in the photoelectric smoke detector which concerns on one embodiment of this invention, the state which looked at the labyrinth structure from the side surface (Fig.3 (a)), and removes a lower cover The state seen from the lower surface (FIG. 3B) is shown. It is explanatory drawing of the labyrinth structure installed in the photoelectric smoke sensor which concerns on one embodiment of this invention, and has shown the state seen from diagonally, disassembling a part of labyrinth structure.

[Embodiment 1]
The photoelectric smoke detector according to the present embodiment will be described with reference to FIGS. In the following, first, the external shape of the photoelectric smoke detector will be described with reference to FIG. 1, and then the internal structure of the photoelectric smoke detector will be described with reference to FIGS.
The photoelectric smoke detector 1 according to the present embodiment includes a base 3 attached to a ceiling or the like, and a main body 5 installed on the upper portion of the base 3 in the state shown in FIG.
The main body 5 is provided with an insect repellent member 7 formed by laminating doughnut-shaped thin disks separated by a predetermined distance along the outer periphery of a labyrinth structure 17 described later.

As shown in FIG. 2, the photoelectric smoke detector 1 includes a circuit board 9 installed on the main body 5, an optical bench 11 installed on the circuit board 9, and a light emitter installed on the optical bench 11. 13 and a light receiver 15 and a labyrinth structure 17 installed so as to surround the optical bench 11, and an internal space surrounded by the labyrinth structure 17 is a smoke detection space 19.
Hereinafter, the main parts constituting the photoelectric smoke detector 1 will be described in more detail.

<Optical stand>
On the optical bench 11, a light emitter housing portion 11 a for housing the light emitter 13, a light receiver housing portion 11 b for housing the light receiver 15, and the light emitted from the light emitter 13 is blocked and the light is directly received by the light receiver 15. A light shielding column 11c is provided to prevent the light from entering the light.
As shown in FIG. 2, the light emitter housing portion 11a and the light receiver housing portion 11b are installed such that the light emitter 13 and the light receiver 15 housed therein are arranged at a predetermined angle. A light shielding column 11 c is installed in the vicinity of an intermediate position between the light emitter 13 and the light receiver 15, and the installation position of the light shielding column 11 c is the center of the smoke detection space 19. An inner bearing 31 that rotatably supports an inner rotating shaft 27 installed in a labyrinth structure 17 described later is provided on the top of the light shielding column 11c.

<Labyrinth structure>
The labyrinth structure 17 has a function of blocking light from the outside and attenuating light emitted from the light emitter 13.
The labyrinth structure 17 having such a function has a donut shape as shown in FIGS. 2 and 3, and the optical bench 11 is placed in the smoke detection space 19 formed at the center thereof. Has been placed. As shown in FIGS. 3 and 4, the labyrinth structure 17 has a disk-shaped upper cover 21 on the upper side and a lower cover 23 having a donut plate shape on the lower side. At the center of the upper cover 21, an external rotation shaft 25 protruding outward and an internal rotation shaft 27 protruding inward are formed. The external rotary shaft 25 is supported by an external bearing 29 provided at the center of the main body 5, and the internal rotary shaft 27 is supported by an internal bearing 31 provided at the top of the light shielding column 11 c, thereby the labyrinth structure 17. It is supported rotatably.

In such a labyrinth structure 17, a plurality of labyrinth members 33 (see FIGS. 2 to 4) having a shape similar to a blade cross-sectional shape with a substantially square cross section in the axial direction are arranged on the same circumference at regular intervals. It is formed by.
Since the labyrinth structure 17 is rotatably installed and the labyrinth member 33 has a cross section similar to the blade cross-sectional shape, the air flow caused by the fire is caused by the labyrinth member 33 as shown in FIG. The labyrinth structure 17 rotates by hitting and positively guides smoke inside. This makes it easy for smoke to flow into the smoke detection space 19 and improves the response as a sensor.

<Insect repellent>
The insect repellent member 7 is composed of a plurality of donut-shaped disks 35, and the donut-shaped disks 35 are supported by support columns 37 along the outer periphery of the labyrinth structure 17 and are laminated through a minute gap. Yes.
In the insect screen of the conventional example, smoke flows so as to lick the peripheral surface and the inflow thereof is insufficient. However, by configuring the insect repellent member 7 as described above, the air resistance is low and the smoke is reduced to the labyrinth structure 17. It can flow smoothly into.
Therefore, a smooth introduction of smoke is realized by a synergistic effect with the rotation of the labyrinth structure 17, and the photoelectric smoke detector 1 having excellent response to smoke is obtained.

In the above embodiment, the shape of the labyrinth member 33 constituting the labyrinth structure 17 is exemplified as a shape similar to the substantially cross-sectional shape of the blade, but the present invention is not limited thereto. Instead, any other shape may be used as long as the shape can be rotated by the airflow during a fire.
In the example shown in FIG. 2, the support 37 is formed by forming protrusions having a very small height on the donut-shaped disk 35. However, if the donut-shaped disks 35 are stacked with a predetermined minute gap, the support 37. May have other configurations.
In the above embodiment, a donut-shaped disk is shown as a member constituting the insect-control member of the present invention. However, a curved flat plate is continuously arranged in the circumferential direction instead of the donut-shaped disk. At the same time, it may be laminated in the vertical direction through a minute gap.

DESCRIPTION OF SYMBOLS 1 Photoelectric smoke detector 3 Base 5 Main part 7 Insect-proof member 9 Circuit board 11 Optical stand 11a Light emitter accommodating part 11b Light receiver accommodating part 11c Light-shielding pillar 13 Light emitter 15 Light receiver 17 Labyrinth structure 19 Smoke detection space 21 Upper cover 23 Lower cover 25 External rotating shaft 27 Internal rotating shaft 29 External bearing 31 Internal bearing 33 Labyrinth member 35 Donut-shaped disk 37 Post

Claims (4)

A labyrinth structure that allows inflow of smoke from the outside and blocks light from the outside to form a smoke detection space; and a light emitter that emits light toward the smoke detection space formed by the labyrinth structure; In a photoelectric smoke detector comprising a light receiver that receives light scattered from the light emitter by smoke particles in the smoke detection space,
A photoelectric smoke detector, wherein the labyrinth structure is rotatably installed.   The labyrinth structure is formed by arranging a plurality of labyrinth members having a substantially square cross section on the same circumference at regular intervals, and rotating by providing a rotation shaft supported by a bearing at the center. 2. The photoelectric smoke detector according to claim 1, wherein the photoelectric smoke detector is installed freely.   The photoelectric smoke detector according to claim 2, wherein the rotation shaft is supported by a light shielding column installed in the smoke detection space.   4. An insect repellent member installed along the outer periphery of the labyrinth structure, wherein the insect repellent member is formed by laminating flat plates with minute gaps. The photoelectric smoke detector according to any one of the above.