RU66577U1 - FIRST OPTICAL ELECTRONIC FIRE DETECTOR - Google Patents

Abstract

The utility model relates to the field of fire alarms, namely, devices for detecting fires that are accompanied by the appearance of smoke in enclosed spaces by detecting optical radiation reflected from smoke particles. The technical result is an increase in detector reliability, manufacturability and maintainability achieved by the modular design of the light source and the light receiver, made in the form of lodges, consisting of two parts, fastened together by means of latches, shielding the outputs of the photodiode. The upper and lower protective covers of the electronic board are additionally introduced into the detector, on which the detector cover is fixed.

Description

The inventive utility model relates to the field of fire alarm, namely, devices for detecting fires, accompanied by the appearance of smoke in enclosed spaces, by detecting optical radiation reflected from smoke particles.

Known патент G08B 17/10, 1997.07.15, containing a fixed insert with an optical module consisting of a light source, a light detector, a measuring chamber, a central hood, a bottom and a labyrinth system with blends located on the periphery of the measuring chamber . The details of the optical module have a shiny surface and are capable of reflecting background light. This device is difficult to manufacture, install and repair.

Closest to the claimed utility model is selected as a prototype содержащий containing a housing mounted in the housing of an optical module including a light source, a light detector, a labyrinth system . The detector housing contains a socket, base, cover. The socket and the base are equipped with a set of protrusions for their mutual connection. The socket and the base are equipped with contacts, the interaction of which ensures the electrical contact of the detector with the fire alarm loop. The labyrinth system is formed by the articulation of the plates of the upper and lower parts of the smoke chamber. The optical module is shielded from above by a metal plate, its side surface is covered with a protective grid. The disadvantage of the prototype is the design complexity of the optical module, in which the smoke chamber is made as one unit with a light source and a light receiver. This design of the optical module is difficult to manufacture and repair, leads to an increase in material consumption and complexity, and as a result, to increase

device cost. With this design of the optical module, it is difficult to accurately install and align the optical system, which reduces the reliability of the detector. The shielding of the optical module made by a metal plate mounted on top also increases the material consumption of the device and the complexity of installation.

The technical result provided by the claimed utility model is to increase the reliability of the detector, manufacturability and maintainability.

This goal is achieved by the fact that the light source and the light detector installed in the detector housing are made in the form of separate modules mounted on a printed circuit board and not rigidly connected to the smoke chamber. The modules of the light source and the light receiver are made in the form of lodgements with an LED and a photodiode installed on them and mounted on a printed circuit board, the outputs of the photodiode are closed from the outside by a metal screen mounted on the printed circuit board. The lodgements are made of two parts fastened together by means of latches. The upper and lower protective covers of the electronic board are additionally introduced into the detector. The protective covers are fastened together so that they close the electronic board, and the upper cover of the detector is fixed to the protective covers.

In the device claimed in the utility model, the modular design of the light source and the light receiver are not rigidly connected to the smoke chamber, as was done on the prototype, but are made in the form of separate lodgements with an LED and a photodiode installed on them and mounted on a printed circuit board. Each lodgement consists of two parts, fastened together by means of latches. This design of the light source and the light receiver simplifies the technology of installation, assembly work, as well as repair. The lodges allow for accurate alignment of the LED and photodiode, which increases the reliability of fire detection. The screening of the photodiode, on which the reliability of fire detection depends, in the inventive model is made by a screen covering only the conclusions of the photodiode. Such a solution, in comparison with the prototype, provides more effective shielding, which allows to maintain the detector's operability under the influence of electromagnetic interference and to save material in the manufacture of the screen. Upper and lower protective covers fastened together

reliably protect the printed circuit board with electronic elements mounted on it from dust and dirt, moisture, shock and deformation, provide convenient fastening of the detector's top cover.

The essence of the device is as follows.

In Fig.1, 2 presents a General view of the device, Fig.3 - module of the light source (light receiver).

The detector housing contains a socket 1 and a cover 2. In the detector housing on the electronic board 3, a light source module 4, a light detector module 5, a smoke chamber 6 are closed and closed by a protective net installed on the outside of the perimeter 7. The housing of the light source module 4 and the module housing the light receiver 5 is made in the form of lodgements consisting of two parts — part 8 with holes and part 9 with latches 10. An infrared LED 11 is installed in the lodgement of the light source 4, and a photodiode 12 is installed in the lodgement of the light receiver 5, both parts are the pallets are fastened together by latches 10. The terminals of the LED 11 and the photodiode 12 are mounted on the electronic circuit board 3, and the terminals of the photodiode 12 are closed externally by a metal screen 13 mounted on the electronic circuit board 3. The electronic circuit board 3 is closed by the upper 14 and lower 15 protective covers fastened between the latches 16. The cover of the detector 2 is mounted on the protective covers 14 and 15. The protective covers 14 and 15 with the electronic board 3 and the cover 2 are installed in a certain way (not shown) in the socket 1, while the electrical contact ics board 3 and the socket 1.

The device operates as follows.

When a room ignites, smoke enters the smoke chamber 6. Light pulses emitted from the infrared LED 11, reflected from the smoke particles, enter the photodiode 12, generating an electrical signal that is processed by the electronic circuit board 3 and enters the fire alarm system as a fire signal.

The advantage of the inventive detector is to increase reliability, improve manufacturability, maintainability and reduce material consumption by simplifying its design.

The performance of the claimed device is confirmed by tests of the developed sample.

Claims (5)

1. Optical-smoke optical smoke detector comprising a housing including a socket and a cover, a light source, a light detector, a smoke chamber installed in the housing, characterized in that the light source and the light detector are made as separate modules mounted on an electronic circuit board, the upper one is additionally introduced and lower protective covers of the electronic board. 2. The detector according to claim 1, characterized in that the casing of the light source and the casing of the light detector are made in the form of lodgements consisting of two parts fastened together by means of latches. 4. The detector according to claim 1, characterized in that the light detector is protected from electromagnetic interference by a metal screen mounted on an electronic board on the outside of the light receiver. 5. The detector according to claim 1, characterized in that the upper and lower protective covers are fastened together by means of latches so that they close the electronic circuit board. 6. The detector according to claim 1, characterized in that the detector cover is mounted on protective covers.