JP2506305Y2 - Scattered light smoke detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a scattered light smoke detector that detects a fire by utilizing light scattering.

2. Description of the Related Art In a conventional scattered light smoke detector, a light emitting element and a light receiving element are arranged in the smoke detecting section inside the detector with a predetermined angle offset from the facing position. Is scattered by smoke particles, and a fire is generated when the received light output of the light receiving element due to the scattered light exceeds a value corresponding to a predetermined concentration.

In the smoke detector, a test lamp for detecting the detector and adjusting the sensitivity is provided facing the light emitting element.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The conventional scattered light type smoke sensor has a drawback in that the light from the light emitting element collides with the window surface of the test lamp and causes irregular reflection, resulting in a large amount of noise light. In particular, when the smoke detecting section is made small, the test lamp and the light receiving element are close to each other, which has a great influence.

Therefore, in order to reduce the noise light, a method of embedding a test lamp between the peripheral walls of the labyrinth structure provided around the smoke detector and in the optical stand is used. However, although this method can reduce noise light, on the other hand, the former method makes it difficult for smoke to flow into the smoke detection section, and in the latter method, the height on the optical bench is the height of the test lamp. Since it becomes high, the whole sensor becomes large.

In view of the above situation, the present invention is to prevent the test lamp from increasing the noise level. Another object is to facilitate the flow of smoke into the smoke detector and to reduce the size.

Means for Solving the Problems The present invention provides a scattering device including a light emitting element, a light receiving element, a peripheral wall of a labyrinth structure surrounding a smoke detector, and a test lamp provided immediately before a light receiving window of a light receiving element holder. An optical smoke sensor, wherein the optical axes of the light emitting element, the light receiving element, and the test lamp are formed parallel to the bottom surface of the sensor, the test lamp is provided to face the peripheral wall, and the light receiving element is provided. In order to achieve the above-mentioned object, a scattered light smoke detector located outside the monitoring range of

When smoke enters the smoke detection section between the peripheral walls of the labyrinth structure, the direct light of the light emitting element collides with the smoke and becomes scattered light,
Enter the light receiving element of the light receiving unit holder. At this time, since the test lamp is provided outside the monitoring range of the light receiving element, the scattered light does not collide with the test lamp, so that diffused reflected light does not occur. Further, since the test lamp is not arranged between the peripheral walls, the smoke can be smoothly distributed to the smoke detecting section.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings, in which the same reference numerals have the same names and functions.

The smoke detecting section 20 is formed by a combination of the optical base 3 and the optical base cover 6, and the light emitting element holder 9 and the light receiving element holder 10 are provided in a position where the light emitting element 4 and the light receiving element 5 do not face each other. Around the smoke detector 20, there is provided a peripheral wall 11 that forms a labyrinth structure formed by combining the substantially "J" shapes.

A light shielding wall 12 having a V-shaped cross section is provided between the holders 9 and 10 so that the light of the light emitting element 4 does not directly enter the light receiving element 5.

On the front surface of the light emitting element 4, there are provided a reflection wall 13 having an arrow-shaped cross section that directly reflects light to the left and right, and defense walls 14 and 15 having a V-shaped cross section for preventing the reflected light from returning to the inside of the smoke detector 20. There is.

A test lamp 17 facing the peripheral wall 11 is provided directly above the light receiving window 16 of the light receiving element holder 10. The test lamp 17 is installed immediately before the light receiving window 16 and in a position other than the monitoring range S of the light receiving element 5 so that scattered light does not collide with the test lamp 17 and irradiate the light receiving element 5. However, this test light 17
It may be fixed to the holder 10 or may be provided separately from the holder 10.

As the test lamp 17, for example, a light emitting diode is used. The light emitting element 4, the light receiving element 5, and the test lamp 17 are
Each optical axis is formed parallel to the bottom surface of the sensor body 1.

In addition, 1 is a sensor main body, 2 is a printed circuit board having a circuit element provided on the upper surface, 3 is a smoke detector 20, and an optical stand having a light emitting element 4 and a light receiving element 5 therein, and 6 is an optical stand cover. , 7 are insect screens, and 8 is a sensor cover.

The circuit diagram of this scattered light smoke detector is constructed as shown in FIG. 3, in which 18 is a pulse lighting circuit having an oscillator for pulse lighting the light emitting element 4 and 19 is a light receiving device. Amplifying circuit that amplifies the output of element 5, 20 is SC
A switching circuit for R or the like, 21 is a test switch provided in a sensor or a receiver, and 22 is a test power supply.

 Next, the operation of this embodiment will be described.

The direct light of the light emitting element 4 collides with the reflection wall 13 while always illuminating the inside of the smoke detecting section 20, becomes primary reflected light, and its traveling direction is changed to collide with the defense walls 14 and 15. Then, this reflected light is reflected by the defense walls 14 and 15 to become secondary reflected light and is emitted to the outside.

Therefore, almost no scattered light is generated within the monitoring range S of the light receiving element 5, so there is almost no output from the light receiving element 5 to the amplifier circuit 19.

When a smoke causes smoke having a predetermined concentration or more to pass through the peripheral wall 11 of the labyrinth structure and enter the smoke detector 20, the light emitting element 4
The direct light emitted from is scattered by smoke and becomes scattered light, enters the monitoring range S of the light receiving element 5, and is detected by the light receiving element 5. Then, the light receiving element 5 outputs and the amplifier circuit
The switching circuit 20 operates via 19 to send a fire signal to a receiver or the like (not shown).

At this time, since the test lamp 17 is located outside the monitoring range S of the light receiving element 5, the scattered light becomes diffused reflected light by the test lamp 17 and does not illuminate the light receiving element 5.

Further, smoke can be smoothly introduced into and discharged from the smoke detecting section because the test lamp 17 does not exist between the peripheral walls 11.

When performing the operation test or sensitivity test of this sensor,
The test switch (21) is closed, and the test light emitting diode (test lamp) (17) is turned on with a predetermined brightness to generate the test light. This test light collides with the front peripheral wall 11 to become scattered light and enters the monitoring range S of the light receiving element 5, but this pseudo scattered light is equivalent to the scattered light generated by smoke of a predetermined concentration. If the detector is normal, the output of the light receiving element 5 causes the switching circuit 20 to operate via the amplifier circuit 19, and a fire signal is sent to a receiver or the like (not shown) to confirm the state of the detector. . If the output of the amplifier circuit 19 can be read, the sensitivity of the sensor can be known correspondingly.

Effect of the Invention The scattered light type smoke detector according to the present invention is as follows.
The optical axes of the light emitting element, the light receiving element, and the test lamp are formed in parallel with the bottom surface of the sensor, and are provided in front of the light receiving window of the light receiving element holder so as to face the peripheral wall, and the light emitting element monitoring range is provided. Since the test lamp located outside is provided, the scattered light generated in the smoke detector does not collide with the test lamp and diffusely reflect to irradiate the light receiving element.

Therefore, since the noise level can be made lower than that of the conventional example, the performance of the sensor can be improved, and the sensor can be made smaller than the conventional example.

Further, unlike the conventional example, since the test lamp is not provided between the peripheral walls of the labyrinth structure, the smoke flow to the smoke detecting section is not obstructed.

Therefore, since the smoke can be smoothly distributed to the smoke detector,
The fire can be detected accurately.

[Brief description of drawings]

1 to 4 are views showing an embodiment of the present invention, respectively.
1 is a sectional view taken along the line II of FIG. 2, and FIG. 2 is II of FIG.
-II line sectional drawing, FIG. 3 is a block diagram showing an electric circuit, and FIG. 4 is a vertical sectional view showing a usage state. 10 …… Receiving element holder 11 …… Surrounding wall 16 …… Receiving window 17 …… Test lamp 20 …… Smoke detector S …… Receiving element monitoring range

Claims (3)

(57) [Scope of utility model registration request] 1. A scattered light type smoke detector comprising a light emitting element, a light receiving element, a peripheral wall of a labyrinth structure surrounding a smoke detecting section, and a test lamp provided immediately before a light receiving window of a light receiving element holder. The optical axes of the light emitting element, the light receiving element, and the test lamp are formed parallel to the bottom surface of the sensor, the test lamp is provided so as to face the peripheral wall, and is located outside the monitoring range of the light receiving element. The scattered light type smoke detector characterized by being. 2. The scattered light type smoke detector according to claim 1, wherein the test lamp is arranged right above the light receiving window. 3. The scattered light smoke detector according to claim 1, wherein the test lamp is provided in the light receiving element holder.