JPS5818149A - Light depreciation type smoke detector - Google Patents

Abstract

PURPOSE:To make the maintenance and inspection easy, by clipping an optical reflection mirror forming an optical path of a sensor with a holder freely removably and inserting an external cover forming a smoke detection section to a sensor main body. CONSTITUTION:A sensor 1 and an external cover 13 inserted to the detector 1 form a smoke detection section 14, and a pair of optical reflection mirrors 10 forming an optical path 12 of light emitting and photodetection elements 2, 3 for sensing are clipped with projections 9a of reflection mirror holders 9 freely removably. Through this constitution, the optical reflecting mirrors which are easily adversely affected by dirt on the surface can easily be removed, allowing to make the maintenance and inspection of the depreciation type smoke detector easy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spot type dimming type smoke detector using an optical element and a light reflecting mirror.

Spot-type smoke detectors measure a predetermined attenuation rate of the amount of light that reaches the light-receiving element from the light-emitting element within the sensor housing.In order to accurately measure this attenuation rate, The optical path length must be greater than a certain value within the sensor housing, which is a small container, and a technique using a light reflecting mirror has been considered as a countermeasure to this problem. However, since the smoke sensor a detects the intrusion of smoke, the light reflecting mirror is exposed to the air containing a large amount of dust etc. in the smoke detecting part Kb. If the surface becomes dirty due to the adhesion of dust, the light reflection function will be significantly reduced and the sensor will no longer function as a sensor. Furthermore, since the light reflecting mirror described above reflects the light from the light emitting element back and forth multiple times to form an optical path, dirt on its surface is more likely to have a negative effect on performance than other optical elements. be.

The present invention has been made in view of the above points, and by adopting a mounting structure that allows the light reflecting mirror, which is most susceptible to the adverse effects of surface dirt, to be easily attached to and detached from the sensor body, it is possible to easily attach and detach the light reflecting mirror during maintenance and inspection. The object of the present invention is to propose a dimming type smoke detector in which the surface of the reflecting mirror can be polished to eliminate all of the above-mentioned conventional drawbacks.

The present invention will be described below based on embodiments shown in the drawings. Figure 1 is an exploded perspective view of the smoke detector of the present invention, Figure 2 is a vertical sectional view when assembled, and Figure 3 is a plan view of the main parts.

In each of the above figures, the dimming type smoke detector of the present invention has a reflecting mirror holding part 9.9 formed on one end surface of the sensor main body 1 equipped with an optical element, and a pair of light reflecting mirrors 10 in the holding part 9. .10 is detachably held to form an optical path 12, and an outer cover 13 is fitted to the sensor main body 1 to close the outer cover 1.
A smoke detection section 14 is formed between the sensor body 1 and the sensor body 1.

For example, the sensor main body 1us is formed by fitting the upper frame IA and the lower frame IB at their peripheries, and forming a sealed structure that prevents smoke from flowing into the inside.

Inside this sensing body l, a light emitting element 2 and a light receiving element wire are mounted on a circuit board 5, and the board 5 is fixed to the back side of the upper frame IA with screws 6. . Of course, each of the above-mentioned optical elements may be mounted on the lower frame IB inside the main body 1, or may be mounted on the surface outside the main body 1.

An inwardly recessed space 7 is formed on one end surface of the sensor body 1, and the reflecting mirror holder 9.9 is provided on the opposing wall surfaces 8.8 of this space 7. As shown in FIGS. 1 and 3, this reflector holding part 9 is constructed by providing a pair of L-shaped protrusions 9a, 9a at arbitrary intervals on both sides of the wall surface 8. 8 and are formed opposite to each other.

Each reflecting mirror holding part 9 consists of the above-mentioned set of protrusions 9m and 9m.
．． 9, a pair of light reflecting mirrors 10 and 1G are mounted and held in a manner such that they can be attached and detached from above by using protrusions 9m and 9aK on both sides of the mirrors. As a fixed punch for the light reflection fa10, a protrusion 18 provided on one wall fli8 as shown in FIG.
Alternatively, the protrusion 9a may be formed of an elastic member such as synthetic resin and a pressure bonding method may be used.

In the above embodiment, the mirror holding portion 9.9 is formed in a recessed state within the space 7 of the sensor main body 1, but is not limited to this, and may be formed in a protruding state on the surface of the main body 10. Of course, it is a good thing.

On each of the above wall surfaces 8.8: At the ends of the non-opposing parts,
A pair of light transmitting parts 11 and 11 through which light passes is provided, and the above-mentioned light emitting element 2 and light receiving element 3 are positioned on the inner front surface of the light transmitting parts 11 and '11. For example, this transparent part 11 has a through hole in the wall 11i8 so that light can pass therethrough, and the through hole is closed by a light reflecting mirror 10, and then a light reflecting mirror 10 is formed. A passage portion is provided by peeling off the reflective film on one back surface at a location corresponding to the through hole, and the light transmitting portion 11 is substantially constituted by this through hole and the passage portion.

An optical path 12 is formed between the light emitting element 2 and the light receiving element 3 by the light reflecting mirrors 10.10 facing each other via the light transmitting portion 11.11. That is, as shown in FIG. 3, the light emitted from the light emitting element 2 through the light transmitting part 15II at a certain angle is reflected back and forth multiple times through the pair of light reflections *lo and 1o, and then reaches the other light transmitting part 11. The light is received by the light receiving element 3 via the light receiving element 3. By using the light reflecting mirror 10.10 in this way, a particularly long optical path 12 can be arbitrarily formed, and a predetermined light attenuation rate due to smoke generation can be reliably obtained. The light reflecting mirror 10 is formed of a flat plate made of glass, resin, thin metal plate, or the like.

The optical path 12 described above can also be configured as shown in FIG. That is, in the case of the second embodiment, the light emitting element 2
and the light-receiving element 3 by light reflection [1
0, and the light from the light emitting element 2 is directly irradiated onto the light reflecting mirror 10 without going through a light-transmitting part, thereby forming an optical path 12.

Next, an outer cover 13 is fitted onto the end surface (surface portion) K of the sensor main body 1 so that a smoke detection portion 14 is formed between the outer cover 13 and the end surface portion of the main body 1 . This smoke detection section 1
4#i, the optical path 12 is positioned approximately at the center. A cylindrical rope portion 15'f is attached to the outer peripheral portion between the outer cover 1 and the sensor body 1 to prevent the center portion from entering the smoke detection portion 14.

The attenuation type smoke detector of the present invention described above has a sensing main body I having a light emitting element 2, a light receiving element 3, and an electric circuit 4, and is provided with a pair of light reflecting mirrors 10.10. An optical path 12 is formed, and when smoke enters a smoke detection section 14 including this optical path 12, the electric circuit 4 reads the attenuation rate of the amount of light. - For maintenance and inspection of the detector, remove the outer cover 13 from the main body 1, and remove the light reflecting mirror 10, 10f from the reflecting bell holding parts 92, 9,
Polish and clean the surface.

As described above, the dimming type smoke detector of the present invention adopts a configuration in which a pair of light reflecting mirrors forming an optical path are detachably attached to and held in a reflecting mirror holding part consisting of a pair of protrusions. Therefore, as a smoke detection optical device, the above-mentioned light reflecting mirror, which dislikes dirt on the electrically conductive surface, can be removed independently from the sensor body, making polishing and cleaning of the mirror surface extremely easy. .

Moreover, since the light reflecting mirror is mounted in a different structure from other optical elements, it can be taken out from the main body by removing the outer cover from the main body and then pulling it out from the holding part.
'c.It is extremely advantageous for the maintenance and inspection of the sensor because it can be easily removed and installed.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of the smoke detector of the present invention, FIG. 2 is a vertical sectional view when assembled, FIG. 3 is a plan view of the main part, and FIG. 4 is a plan view of the main part of another embodiment. l...Sensor body 2...Light emitting element 3...
Light receiving element 4...Electric circuit 5...Circuit board 6...Screw 7...Space 8
...Wall surface 9...Reflector holding part 10...Light reflector 11...Transparent part 12...Optical path 13
...Outer cover 14...Smoke detection section 15...
Tsunabe Applicant Hochiki Co., Ltd. 2

Claims (1)

[Claims] A pair of protrusions are provided on both sides of one end surface of the sensor body, which includes a light emitting element, a light receiving element, and a desired electric circuit, to form a reflecting mirror holder that faces each other. By holding a pair of light reflecting mirrors in a removable manner with their both sides sandwiched between them, an optical path is formed between the light emitting element and the light receiving element, and an outer cover is provided on one end surface of the sensor body. A dimming type characterized in that a smoke detection section is formed between the outer cover and the sensor body by fitting them together.