JPS5850478Y2 - photoelectric smoke detector - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a photoelectric smoke detector.

A photoelectric smoke detector has a light-emitting element and a light-receiving element placed inside a dark box that blocks outside light and only allows smoke to enter.The light-emitting element is periodically turned on to detect smoke inside the dark box. When the smoke particles flow in, a light receiving element detects the scattered light caused by the smoke particles, and this detection signal sounds an alarm buzzer to generate a fire alarm.

As mentioned above, such a photoelectric smoke detector includes a dark box, a sensor part consisting of a pair of light emitting and light receiving elements, a signal processing circuit that processes signals from this sensor part, a drive circuit that sounds an alarm buzzer, etc. These are assembled into a case.

The present invention aims to simplify assembly by efficiently arranging all of the above-mentioned components on both the upper and lower main surfaces of a single intermediate plate, and to form a simple structure that is a dark box into which smoke can enter. This is what I did.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 indicates a photoelectric smoke detector, which includes an upper cover 2, an intermediate plate 3, and a lower cover 4.

The top cover 2 is fixed to a ceiling surface 6 with mounting brackets 5.

Further, the intermediate plate 3 and the lower cover 4 are each fixed to the upper cover 2.

The mounting structure of the smoke detector 1 to the mounting bracket 5 is as shown in FIG.

That is, bending keys 7, 7 are formed at both ends in the longitudinal direction of the approximately diamond-shaped mounting bracket 5, and a circular protrusion guide part 8 is provided in the center. It is screwed to a wall surface such as a ceiling through the holes 9, 9.

Reference numeral 10 denotes a presser portion provided in the short axis direction of the mounting bracket 5, and reference numeral 11 denotes an adhesive layer that facilitates attachment to a ceiling surface.

On the other hand, the top cover 2 of the smoke detector 1 is provided with engaging grooves 13 at positions corresponding to the key portion T and the guided portion 12 having a circular recess that fits into the guide portion 8 of the mounting bracket 5. It is being

Therefore, by pressing the guided portion 12 of the top cover 2 against the guide portion 8 of the mounting bracket 5 and further rotating it,
The key parts 7, 7 are slid into the engagement grooves 13, 13 from the lateral direction.

At this time, a microprotrusion 14 is provided in each of the key parts 7, 7, and a microgroove 15 is provided in the corresponding retaining groove 13.13,
If the microprotrusion 14 is engaged with the microgroove 15,
Fixation of the smoke detector body becomes more secure.

When attaching the main body, if the key parts 7, 7 are configured to be slightly bent toward the main body, the holding part 10 will push the main body downward, and the key parts 7, 7 will pull the main body upward. Therefore, the main body is fixed even more strongly.

FIG. 3 shows the inner surface of the top cover 2, and shows the retaining groove 13.1.
A large number of windows 16, 16, . . . 3 are formed near both ends and on the side walls for allowing smoke to flow in.

Reference numeral 17 corresponds to one wall of a dark box, which will be described later, and is painted black.

FIG. 4 shows the structure of the upper surface of the intermediate plate 3, in which two windows 18, 18 are formed adjacent to each other approximately in the intermediate plate, and these windows constitute a part of the sensor part 19, which will be described later. Furthermore, a plurality of light shielding plates 20, 20, etc. are arranged approximately circularly around this.
・is provided.

The light shielding plates 20, 2 (L-... are formed by cutting out a part of a circle, and are arranged so as to overlap each other alternately, so that they are surrounded by the light shielding plates 20, 20... No light from the outside enters the dark box 21, and only smoke can enter.

Reference numeral 22 is a smoke guide plate formed integrally with these light shielding plates 20, 20, and at the same height, and is arranged radially outward from the measurement area portion of the dark box 21, that is, the sensor portion 19. It is set up.

As a result, smoke flowing in from the windows 16, 16, . . . of the smoke detector 1 is introduced into the dark box 21 along the smoke guide plate 22.

Reference numeral 23 denotes a dust removal filter provided between the light shielding plates 20, which prevents malfunctions due to intrusion of dust other than minute particles such as smoke particles into the dark box 21.

This intermediate plate 3 is screwed to the top cover 2 through screw holes 24.

An engaging piece 25 (FIG. 5) is formed on the side surface of the intermediate plate 3 facing the screw hole 24, and this retaining piece 25
It is engaged with and fixed to the window 16 of the top cover 2.

At this time, the light shielding plates 20, 20... and the smoke guide plate 22
The upper end is in contact with the lower surface of the upper cover 2, and the incidence of external light into the dark box 21 is completely blocked.

Here, it goes without saying that it is preferable that the upper surfaces of the light shielding plate 20 and the intermediate plate 3 are made of black plates.

26 is an element fixing frame constituting the sensor part 19, and four retaining pieces 27 provided in the center are connected to the window 18.1 of the intermediate plate 3.
8 side walls respectively.

Furthermore, grooves 28.28 are provided at both ends of the fixed frame 26, each inclined at a predetermined angle, and in these grooves 28.28, as shown in FIG. A photodiode is arranged respectively.

The light emitting and receiving optical paths of the light emitting element 29 and the light receiving element 30 intersect at a predetermined angle, and a shielding plate 31 is provided in the center of the fixed frame 26 so that the light from the light emitting element 29 is directly transmitted to the light receiving element. It is configured so that it does not enter the 30.

Therefore, the near-infrared light emitted from the light emitting element 29 is
The inside of the dark box 21 is irradiated through the window 18.

When there is no smoke in the dark box 21, the light receiving element 3
At zero, this light does not enter, but smoke is present, and when smoke particles are located on the emission optical path, the light is scattered by the smoke particles, and a part of it is incident on the light receiving element 30.

In addition, in Fig. 4, 32 is an inspection switch for the intermediate plate 3.
It is placed adjacent to the dark box 21 on the top surface.

A light reflecting needle 33 is attached to the tip of this switch 32, and when the switch 32 is moved downward in the figure against the spring 34, the center of the dark box 21, that is, the light emitting optical path of 2°9 of the light emitting element and the light receiving element. The needle 33 is configured to reach approximately the intersection of the light receiving optical paths 30.

That is, this check switch 32 is used to check whether the smoke detector is operating normally. By pulling this switch 32, the needle 33 is positioned within the light emitting path, scattering the light, and detecting the smoke detector. A part of the scattered light is made incident on the light receiving element 30.

On the other hand, this inspection switch 32 is provided with an operating piece 35 on the opposite side of the needle 33, and this operating piece 35 is connected to the intermediate plate 3.
A switching element, such as a microswitch 31 (FIG. 5), housed in a recess 36 formed in the opening is operated.

This microswitch 31 is driven by the suppression of the operating piece 35 and generates an alarm buzzer signal for a certain period of time.

Therefore, when the inspection switch 32 is pulled and the microswitch 3T is in the activated state, if the light reflected by the needle 33 is incident on the light receiving element 30, an alarm buzzer will sound for about 1 to 2 seconds thereafter.

This buzzer generation can utilize the discharge voltage of the capacitor.

That is, in the alert state, the capacitor is charged with a predetermined charge, and by driving the microswitch 37,
When the charging of this capacitor is stopped and light is detected by the light receiving element in this state, the above-mentioned capacitor is discharged by this detection signal, and this discharge causes an alarm buzzer to sound for an appropriate period of time, for example, 1 to 2 seconds. In addition, in this kind of photoelectric smoke detector, the light emitting element 29 is about 1
It is often configured to emit pulsed light for about 0 seconds,
In such a case, it is necessary to keep pulling the inspection switch 32 for a maximum of about 10 seconds.

FIG. 5 shows the structure of the other main surface, ie, the lower surface, of the intermediate plate 3, where 19 is a part of the sensor and is formed at a position corresponding to the window 18.18.

38 is a circuit board, which includes a light emitting element 29 and a light receiving element 30.
Other necessary electrical parts 39, 39... are packed away.

This substrate 38 is fitted into the sensor part 19 of the intermediate plate 3, and the bent light emitting element 29 and light receiving element 30 are positioned opposite the window 18.18.

With this board 38 attached, the element fixing frame 26 is pushed into this sensor part 19, and the engaging piece 27 is attached to the window 18.
is engaged and fixed.

As a result, the light emitting element 29 and the light receiving element 30 are fixed in a state facing a predetermined direction as shown in FIG. 1, and the fixing frame 26 prevents external light from entering the dark box 21 from the substrate 38 side. .

This board 38 further includes engagement pieces 40 and 40 of the intermediate plate 3.
By engaging the side surfaces thereof and screwing them to the intermediate plate 3 through the screw holes 41, more secure fixation can be achieved.

42 is an alarm buzzer attached to this intermediate plate 3;
Reference numeral 3 denotes a battery case, which is arranged on the intermediate plate 3 in parallel with the substrate 38.

A microswitch 37 constitutes a part of the inspection switch 32 mounted on the lower surface of the board 3, and is housed in the recess 36 of the intermediate board 3 when the board is fixed.

The battery case 43 has a hinge portion 44 formed at one end, and after the battery is housed, an engagement piece 45 provided at the other end engages with a hole 46 provided in the intermediate plate 3 to fix the battery case.

FIG. 6 shows the bottom cover 4, which is provided with four locking portions 47, which are locked and held by the top cover 2 (FIG. 1).

48 is a hole for taking out the inspection switch 32, and 49 is a buzzer 4.
This is a hole provided at a position opposite to 2.

As described above, the photoelectric smoke detector of the present invention has a light shielding plate integrally formed on the upper surface of the intermediate plate to form a dark box, and a part of the sensor, a circuit board, and an alarm buzzer are attached to the lower surface of this intermediate plate. Therefore, when assembling the smoke detector,
First, after fixing the intermediate plate and the top cover with screws, it is sufficient to hook and hold the bottom cover on the locking portion of the top cover, making the assembly extremely simple.

Further, according to the present invention, when the intermediate plate is attached to the top cover, the light shielding plate and the smoke guiding plate serve as spacers between the two, and a dark box is formed at the same time as both are fixed.
The assembly work efficiency is high, and since the smoke guide plate extends radially from a part of the sensor, smoke inflow is ensured, and highly accurate smoke detection is possible.

Furthermore, since the inspection switch is configured to move the needle and drive the microswitch in one operation, inspection operations are easy.

[Brief explanation of drawings]

Fig. 1 is a sectional view of one embodiment of the photoelectric smoke detector of the present invention, Fig. 2 is a perspective view showing the mounting structure of the same side smoke detector, Fig. 3 is a perspective view of the inner surface of the top cover, and Fig. The figure is a top perspective view of the intermediate plate, FIG. 5 is a bottom exploded perspective view of the intermediate plate, and FIG. 6 is an inner perspective view of the top cover. 1...Photoelectric smoke detector, 2...Top cover, 3...Intermediate plate, 4...Bottom cover, 5... Mounting bracket, 20...Light shielding plate, 22...Light guide plate, 21...Dark box, 19...Sensor, part, 29... ...Light emitting element, 30... Light receiving element, 32...
Inspection switch.

Claims (1)

[Scope of utility model registration request] an intermediate plate, a plurality of light shielding plates formed on the main surface side of the intermediate plate so as to surround a predetermined space and intersecting with each other; a top cover formed on the dark box having the predetermined space, a part of the sensor formed on the intermediate plate in a portion corresponding to the predetermined space, and a top cover attached to the main surface side of the intermediate plate. A photoelectric smoke detector comprising a circuit board and a lower cover that covers the circuit board and the intermediate plate and is fixed to the upper cover.