JP3193640B2 - Fire detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a system ceiling T
The present invention relates to a fire detector attached to an air-conditioning inlet such as a bar slit for detecting smoke caused by a fire.

[0002]

2. Description of the Related Art FIG. 13 shows a known fire detector installed in a T-bar slit on a system ceiling. In FIG. 13, a fire detector 102 is attached to a T-bar slit 100 formed as an air-conditioning suction port on the system ceiling by disposing a T-shaped angle member by using an appropriate mounting bracket. The fire detector 102 includes a detector main body case 104 having a built-in smoke detector 108 and a smoke inlet outer cover 106 having an open smoke inlet 110.

[0003] The smoke detector 108 housed in the sensor body case 102 is, for example, a thin cylindrical body, has a smoke inlet opening around the light detector, and a light emitting element and a light receiving element arranged inside thereof with their optical axes shifted. The light receiving element receives the scattered light when the light falls on the inflowing smoke particles to detect a fire.
The sensor main body case 104 disposed above the ceiling is provided with an opening 112 communicating with the internal smoke detection unit 108, for example, at the top, and forcibly restricts the flow of air through the smoke detection unit 108 by using the suction pressure of the air conditioner. Is being produced.

[0004]

By the way, in such a fire detector that detects smoke by using the suction pressure of the air conditioner, the detector main body case 104 and the outer cover 106 are used.
Is made of a bright plastic material such as white or beige according to the ceiling surface. Also, the sensor body case 10
The smoke detection unit 108 housed inside 4 is made of a black or near-black gray plastic material in order to block light from entering from outside and reduce disturbance light due to internal reflection of light from a built-in light emitting element. Have been.

However, the sensor main body case 104 has a bright color such as white or beige, and the black or gray smoke detecting section 108 is housed therein, so that light entering from the outside is a bright case such as white or beige. Light reflected from the inner surface and incident on the smoke detection unit 108 from outside increases. For this reason, the labyrinth structure for shielding the light from the outside provided in the smoke inflow path of the smoke detection unit 108 must be considerably complicated. By complicating the labyrinth structure in this way, the light-shielding property is improved, but at the same time, it is difficult for smoke to pass through, and there is a problem that the smoke inflow characteristics are deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in consideration of the above problems, and has a system ceiling capable of simultaneously shielding external light and ensuring smoke inflow characteristics without complicating a labyrinth structure. It is an object of the present invention to provide a fire detector attached to a T-bar slit or the like.

[0007]

In order to achieve this object, a fire detector according to the present invention is configured as follows. First, the present invention is directed to a fire detector that is attached to a suction port of an air conditioner that is opened like a slit and detects smoke caused by a fire. In the fire detector of the present invention, a sensor body case arranged behind the ceiling with a downward cover mounting opening positioned near a slit-shaped opening of the system ceiling, and a cover mounting opening of the sensor body case from the ceiling surface. The outer cover, which is mounted in a state protruding from the lower part and forms a smoke inlet so that smoke from all directions around it can flow in, and a part of the outer cover is located at a position protruding from a ceiling surface. sensor incorporated into the main body case, and a smoke detection portion formed smoke inlet corresponding to each of all directions of the smoke inlet around the outer cover, the slit opening of the system ceiling sensor body case Formed of a black or gray material that is inconspicuous when viewed through,
The smoke detector is also formed of the same black or gray material of the sensor body case.

[0008] For example, each of the sensor body case and the smoke detector is formed of a black or low-gray synthetic resin material having a low brightness. According to such a fire detector of the present invention, since both the sensor main body case and the smoke detection section are formed of a black or gray material having low brightness, the inside of the case in which the smoke detection section is housed is sufficient. The light entering from the lower part is absorbed and attenuated by the inner surface of the case, and the reflection on the smoke detector can be sufficiently suppressed. In addition, since the intrusion of light due to reflection from the inner surface of the case can be reduced, the light-absorbing labyrinth structure provided in the smoke inflow passage of the smoke detector can be simplified, and as a result, the smoke inflow characteristics can be improved. Can be.

Further, since the sensor case main body and the smoke detector are made of the same black or gray material, the sensor case main body is divided into two parts in the left-right direction, and the smoke case is provided inside one of the case main bodies. The detection unit can be integrally molded, so that the number of assembling steps and cost can be reduced. Furthermore, when installed in a slit-shaped opening in the system ceiling,
In the conventional fire detector, the main body of the detector was a bright color such as white or beige, so that the main body of the detector case in the ceiling could be seen through the slit opening, which was not preferable in terms of the design of the building. Since the sensor body case located behind the ceiling is black or dark gray, it can hardly be seen from the slit-shaped opening, and the problem in design can be solved.

[0010]

FIG. 1A is a front view of a fire detector according to the present invention, FIG. 1B is a side view, and FIG. 1C is a plan view seen from below. 1 (A) to 1 (C), reference numeral 2 denotes a sensor main body case of the fire detector 1. A cover mounting opening 2a is opened at a lower end portion of the sensor main body case 2, and a white color is provided on the cover mounting opening 2a. The outer cover 3 is detachably attached. That is, a pair of protrusions 2b are formed on the lower side surface of the sensor body case 2, and a pair of engagement pieces formed on the upper end of the white outer cover 3 are formed on the engagement portions formed on the back side of these protrusions 2b. It is designed to engage.

The white outer cover 3 is provided with four smoke inlets 4 so that smoke from all directions can flow in. The insect inlet net 4 prevents insects from entering the smoke inlets 4. 4a are attached respectively. The smoke inlet 4 has four smoke inlets, a smoke inlet opening left and front, a smoke inlet opening left and rear, a smoke inlet opening right and front, and a smoke inlet opening right and rear. It consists of an inlet.

An opening 6 is formed in the side surface of the sensor main body case 2 and communicates with an internal smoke detecting portion. The opening 6 allows the air flow from the smoke detecting portion by the suction pressure of the air conditioner. . A locking piece 5 that is locked to a mounting bracket for mounting the sensor body case 2 is incorporated in the opening hole 6. That is, the sensor body case 2 is used as the opening hole 6.
The mounting hole of the locking piece 5 that is locked to the mounting bracket for mounting the is used. For this reason, the opening area for forced introduction using the air-conditioning suction pressure is limited.

The sensor main body case 2 is formed of a material having a low brightness that is inconspicuous when viewed through a slit-shaped opening in the system ceiling. In this embodiment, the sensor main body case 2 is formed of a black or gray synthetic resin material. Note that gray is gray with low brightness close to black.
That is, the sensor body case 2 is constituted by the black cases 11 and 12 divided into two in the left-right direction.

The smoke detecting portion accommodated in the sensor body case 2 is also made of the same black or gray synthetic resin material as the sensor body case 2. For this reason, the inside of the sensor main body case 2 in which the smoke detection unit is housed is sufficiently dark, and light that has entered from the outside is absorbed and attenuated by the inner surface of the sensor main body case 2, so that reflection on the smoke detection unit can be sufficiently suppressed. .

Further, since the invasion of light due to the reflection from the inner surface of the sensor main body case 2 can be reduced, the light-shielding labyrinth structure provided in the smoke inflow passage of the smoke detector can be simplified. As a result, smoke inflow characteristics can be improved. On the other hand, the outer cover 3 mounted on the front side of the ceiling is formed of a synthetic resin material such as white beige according to the color of the ceiling.

FIG. 2 is an explanatory view of a mounted state of the fire detector of the present invention. In FIG. 2, a T-shaped angle member 7 is arranged on the ceiling with a predetermined slit width, supports the ceiling boards 10, and a slit-like opening 36 serving as an air-conditioning suction port is formed therebetween. The sensor main body case 2 of the fire detector 1 is attached to the slit-shaped opening 36 by mounting brackets 8 and 9.

The sensor body case 2 has a cover mounting opening 2a.
Is mounted above the ceiling board 10 above the ceiling board 10 so as to be positioned near the opening of the slit-shaped opening 36. In other words, the first mounting bracket 8 is located behind the ceiling, and the second mounting bracket 9 is located outside the ceiling. In this state, the sensor main body case 2 includes the first and second mounting brackets 8, 8. 9 and at this time the lower second mounting bracket 9
The locking piece 5 of the sensor body case 2 is locked in the locking hole 43 of the sensor body.

A screw member 51 is inserted into the lower second mounting member 9, and the screw member 51 is screwed into the upper first mounting member 8, so that lower ends on both sides of the first and second mounting members 8, 9. The T-shaped angle member 7 is sandwiched and fixed between the first mounting edge 40 and the second mounting edge 41. The sensor main body case 2 arranged behind the ceiling is a black case 11,1.
2 and hardly visible from the slit-shaped opening 36, there is no problem in the design of the ceiling.

FIG. 3 is an exploded view of the sensor body case 2, FIG. 3 (A) shows one body cover of the sensor body case 2, FIG. 3 (B) shows a printed circuit board, and FIG.
(C) shows the other body cover of the sensor body case 2. In FIG. 3A, reference numeral 11 denotes one black case as a main body cover obtained by dividing the sensor main body case 2 in the left-right direction, and the black case 11 is formed of a black or gray synthetic resin material.

The black case 11 has a partition wall 17 formed of a curved portion and an L-shaped portion slightly below the center of the inside. A circuit storage portion 11a for storing circuit components mounted on a printed circuit board is defined above the partition wall 17, and a smoke detection portion storage portion 11b for storing a smoke detection portion is defined below the partition 17.
Is defined. A unit housing portion 11c for housing the insertion terminal unit mounted on the printed circuit board is formed on the upper part of the black case 11, boss portions 18a are formed on both sides of the unit housing portion 11c, and screw holes are formed in the boss portions 18a. 18b is drilled. At the lower end of the black case 11, a cover mounting port 2a for detachably mounting the white outer cover 3 is formed.

A boss 18b having a screw hole 18a formed therein is formed on both sides of the partition wall 17, and a holding portion 11d for holding the plate portion 5a of the locking piece 5 integrally with the boss 18b is formed. . The locking piece 5 is made of a plate-like spring member.
The plate-like portion 5a is formed with a slit hole 1 formed in the holding portion 11d.
The bent protruding portion 5b of the locking piece 5 which is held by 1c and protrudes from the slit hole 11c protrudes outward from the opening hole 6 formed on the side surface of the sensor main body 2.

An insertion terminal unit 15 is mounted on the printed circuit board 13 shown in FIG. 3B so as to protrude therefrom, and various circuit components (not shown) are mounted on the printed circuit board 13 below the insertion terminal unit 15. Is done. Plug-in terminal unit 15
Screw holes 13a are formed in the printed circuit boards 13 on both sides of the printed circuit board. A notch 14 is provided on the lower side of the printed circuit board 13.
The smoke detection unit 14 which is formed of a thin cylindrical body having a and having a protruding introduction portion 16 protruding downward is mounted. The smoke detection unit 14 projects from a part of the cylindrical body in a state of being attached to the lower side of the printed circuit board 13 and projects the introduction unit 16 in a half-moon shape. The half-moon-shaped projection introduction unit 16 is assembled as shown in FIG. In this state, it is located inside the white outer cover 2, and the smoke introduced from the smoke inlet 4 is introduced into the smoke detector 14.

The smoke detector 14 is provided in the sensor body case 2
And the same black or gray synthetic resin material. The smoke detector 14 has a screw hole 14b penetrating the printed circuit board 13. FIG. 3C shows the other black case 12 as a main body cover obtained by dividing the sensor main body case 2 in the left-right direction. The black case 12 is formed of a black or gray synthetic resin material.

A boss 19b is formed at the upper end of the black case 12 to project a pair of screw holes 19a.
Further, a boss 19b having a screw through hole 19a protruding therefrom is formed below the center. A notch 12 a is formed below the black case 12, and the notch 12 a forms a part of the opening 6. Further, at the lower end of the black case 12, a cover mounting port 2a is formed. The printed circuit board 13 is housed in the black case 12, and the black case 11 is inserted into the screw holes 13 a of the printed circuit board 13.
With the screw holes 18a of the
The sensor main body case 2 is assembled by screwing screws into a, 13a, 14a and screw holes 18a.

3 (A) to 3 (C), the sensor body case 2 is a black case 1 divided into two parts in the left-right direction.
1 and 12, and the smoke detector 14 is also made of the same black or gray material as the black cases 11 and 12, so that the inside of the sensor main body case 2 housing the smoke detector 14 is sufficiently dark. Has become. Even if light enters from the lower side of the sensor body case 2, the light is absorbed and attenuated by the inner surface of the sensor body case 2, and is not reflected to the smoke detector 14. For this reason, the labyrinth structure for light shielding provided in the smoke inflow path of the smoke detection unit 14 can be simplified.
As a result, smoke inflow characteristics can be improved.

FIG. 4 is an exploded view of another embodiment in which the labyrinth cover 24 is integrated with the sensor main body case 2. FIG. 4A shows one black case 11 as a divided case obtained by dividing the sensor main body 2 in the left-right direction. A labyrinth cover 24 is formed integrally with the black case 11. That is, the black case 11 is formed of a black or gray synthetic resin material.

FIG. 4B shows a printed circuit board 13. A smoke detection base 22 is fixed to a lower portion of the printed circuit board 13, and the light emitting element 20 and the light receiving element 21
And is fixed to the printed circuit board 13 by soldering.
FIG. 4C shows the other black case as a main body cover obtained by dividing the sensor main body case 2 in the left-right direction. The black case 12 is formed of a black or gray synthetic resin material.

The smoke detector 14 is also made of the same black or gray synthetic resin material as the black case 12. Therefore, the number of assembly steps and cost can be reduced.
FIG. 5 is an explanatory diagram of the internal structure on the black cover 12 side with the black case 11 removed. In FIG.
In the black cover 12, a printed circuit board 13 on which an insertion terminal unit 15 and a smoke detector 14 are mounted is housed. The white outer cover 3 is attached to the cover mounting opening 2 a of the black cover 12 in a state of protruding downward from the ceiling surface 50. Note that the white outer cover 3 is an aa cross section slightly deviated from the center of FIG.

The smoke detecting section 14 has a projecting introduction section 16 which is a part thereof from the cover mounting opening 2a and projects downward. That is, the smoke detection unit 14 is attached to the sensor main body 2 such that the protrusion introduction unit 16 is located at a position inside the white outer cover 4 protruding from the ceiling surface 50, and the smoke detection unit 14 is provided with respect to the air flow from all directions of the white outer cover 3. In order to obtain uniform smoke inflow characteristics, the front, rear, left and right smoke introduction ports 27 and 30 are separately formed in the protruding introduction section 16 located in the white outer cover 3.

Further, inside the white outer cover 3, a partition wall 31 for independently separating the smoke inlets 27 and 30 of the protruding introduction portion 16 of the smoke detector 14 located inside the white outer cover 3.
Are formed. Therefore, the smoke introduced from the front side or the rear side of the white outer cover 3 is guided to the inside of the smoke detector 14 by the partition wall 31 without passing through the rear side or the front side as it is.

For this reason, a uniform smoke characteristic that enables the introduction and discharge from the outer cover 3 to the internal smoke detection unit 14 with respect to the airflow from all directions of front, rear, left and right, which is horizontal around the ceiling surface, is obtained. And is not restricted by the direction of airflow.
6A, 6B, and 6C show the printed circuit board 13 shown in FIG.
It is explanatory drawing of the smoke detection part 14 mounted like this.

In FIG. 6A, reference numeral 22 denotes the smoke detector 14.
The base 22 is fixed to the printed circuit board 13. The light emitting element 20 and the light receiving element 2
1 are arranged with their optical axes shifted from each other, and scattered light generated when light strikes smoke particles entering the smoke detection space 25 is received by the light receiving element 21.
Receive the light and detect the fire. Base 22
The light-shielding plate 22a provided on the light-receiving element 21 restricts light from the light-emitting element 20 so that light does not directly enter the light-receiving element 21.

The base 22 has three engaging portions 22 in the circumferential direction.
The labyrinth cover 24 is mounted on the base 22 by turning the locking pieces 24a formed on the labyrinth cover 24 into these engaging portions 22b by turning them. The state in which the labyrinth cover 24 is attached to the base 22 is shown in FIGS. 6A and 6B, and the protrusion introduction part 16 of the smoke detector 14 protrudes downward from the base 22.

FIG. 6C shows the labyrinth cover 24. Locking pieces 24a for locking to the engaging portions 22b of the base 22 are formed at three locations in the circumferential direction of the labyrinth cover 24. The center of the labyrinth cover 24 is a smoke detection space 25
The smoke detection space 25 is surrounded by a plurality of labyrinths 26. FIG. 7 is a sectional view taken along the line AA of FIG.

In FIG. 7, the engaging portion 22b of the base 22
The locking piece 24a of the labyrinth cover 24 is locked to
A labyrinth cover 24 is mounted on the base 22.
The light emitting element 20 is attached to the base 22, and the light emitting element 20 emits light to the smoke detection space 25. Also, the base 22
The light receiving element 21 is attached to the smoke detector, and when smoke is introduced into the smoke detection space 25 and the smoke particles are irradiated with light, scattered light is generated. The scattered light is received by the light receiving element 21 and a fire is detected.

FIG. 8A is a sectional view taken along the line BB of FIG.
FIG. 8B is a cross-sectional view taken along line CC of FIG. 6B. FIG.
In (A), a plurality of smoke outlets 28 a to 28 e are formed on the outer periphery of the upper smoke detection unit 14 except for the protrusion introduction unit 16, and these smoke outlets 28 a to 28 e are connected to the protrusion introduction unit 16.
The smoke introduced into the smoke detection space 25 from the side is discharged to the outside.
In addition, the labyrinths 26a and 26b allow the smoke discharge space 3
The smoke entering the smoke discharge spaces 32a and 32b is discharged from the smoke discharge openings 28a and 28b.

The protrusion introduction part 16 which is a part of the smoke detection part 14
A plurality of smoke inlets 27a to 27c are formed in the outer periphery of the white outer cover 3, and these smoke inlets 27a to 27c introduce smoke from the left and right directions on the paper surface of the white outer cover 3. The smoke introduced from the smoke inlets 27a to 27c is separated from the smoke inlets 30a to 30e by the labyrinths 26c to 26e.
Through c, it is introduced into the smoke detection space 25.

As shown in FIG. 8B, the projecting introduction portion 16
Is formed with a partition wall 29 in the left-right direction orthogonal to the paper surface. Therefore, the smoke inlets 27a to 27c, 30a to
30c is divided into two in the front and back. For this reason, the smoke introduced from the front and rear into the smoke inlets 30a to 30c is guided from the partition wall 29 to the smoke detection space 25, and then discharged from the opposite side.

FIG. 9 is an explanatory diagram of the smoke inflow characteristic during the air conditioning operation. It is assumed that smoke flows from left to right as indicated by arrow A during the air conditioning operation. The smoke flowing from left to right as shown by arrow A enters the smoke inlet 4 on the left side of the white outer cover 3 as shown by arrow B, and the smoke inlet 27 c formed on the outer periphery of the projecting inlet 16 of the smoke detector 14. , Through the smoke inlet 30c formed by the labyrinth 26e, etc., enters the smoke detector 14, and is introduced into the smoke detection space 25.

A part of the smoke introduced into the smoke detector 14 receives a suction pressure by air conditioning in the ceiling as indicated by an arrow E,
Smoke discharge units 28e and 28f formed on the outer periphery of the smoke detection unit 14.
From the opening 33, and is discharged from the opening hole 6 to the space above the ceiling as indicated by an arrow D1. On the other hand, the smoke introduced into the smoke detection space 25 is, as indicated by an arrow C, the smoke discharge space 32b and the smoke detection unit 1.
4 enters the white outer cover 3 through the space 33b from the smoke outlet 28a, and the smoke inlet 4 on the right side of the white outer cover 3
Is discharged to the outside.

The smoke discharged from the smoke discharge space 32a and the smoke discharge port 28b of the smoke detector 14 into the space 33b is subjected to the air-conditioning suction pressure indicated by an arrow E, and is passed from the opening hole 6 to the space above the ceiling as indicated by an arrow D2. Is discharged. The smoke entering the space 33b is
Due to the presence of the partition wall 17, it does not flow above the sensor body case 2. FIG. 10 is an explanatory diagram of smoke inflow characteristics when air conditioning is stopped. When the air-conditioning is stopped, as shown in FIG. 9, when the smoke flows from left to right, the smoke enters the smoke inlet 4 on the left side of the white outer cover 3 as shown by the arrow A, and the smoke detection unit 14 projects. The arrow B1 passes through a smoke inlet 27c formed on the outer periphery of the portion 16 and a smoke inlet 30c partitioned by a labyrinth 26e or the like.
As described above, the air enters the smoke detection unit 14 and is introduced into the smoke detection space 25. Further, as indicated by an arrow B2, the smoke that has entered the smoke inlet 4 on the left side of the white outer cover 3 is introduced into the smoke detection space 25 via the smoke inlet 30b from the smoke inlet 27b on the outer periphery of the protruding inlet 16. You.

The smoke introduced into the smoke detection space 25 is indicated by an arrow C1.
As described above, the air is discharged to the outside from the smoke inlet 4 on the left side of the white outer cover 3 via the smoke inlet 30a and the smoke inlet 27a. The smoke introduced into the smoke detection space 25 is indicated by an arrow C
As shown in FIG. 2, the smoke enters the space 33b from the smoke detection space 25 via the smoke discharge space 32b and the smoke discharge port 28a, and is also discharged to the outside from the smoke inlet 4 on the right side of the white outer cover 3.

At this time, since the air conditioning is stopped, the suction pressure by the air conditioning does not act on the space 33b through the opening hole 6, and the smoke entering the space 33b is not exhausted from the opening hole 6 to the outside. The smoke is discharged from the smoke inlet 4 on the right side of the white outer cover 3 to the outside. Since the opening hole 6 uses the mounting hole of the locking piece 5 which is locked to the mounting brackets 8 and 9 attached to the sensor body case 2, the opening area for forced introduction using the air-conditioning suction pressure is as follows. Limited.

For this reason, even if the air conditioning is stopped, the smoke detection unit 1
The smoke inflow characteristics for 4 are not significantly reduced. As described above, since the protruding introduction portion 16 of the smoke detection section 14 is located inside the white outer cover 3 below the ceiling surface, smoke along the ceiling surface is directly smoked via the white outer cover 3. Introduced to the detection unit 14, it is possible to quickly detect a fire even if there is no air conditioning suction pressure for stopping air conditioning.

FIG. 11 is an explanatory diagram of smoke inflow characteristics at the time of backflow blowout due to the stop of air conditioning. In FIG. 11, it is assumed that smoke flows from left to right in the reverse flow blowout due to the stoppage of air conditioning as in FIGS. 9 and 10. As shown by the arrow A, the smoke passes through the smoke inlet 4 on the left side of the white outer cover 3, passes through the smoke inlet 27 c of the projecting inlet 16 of the smoke detector 14, and passes through the smoke inlet 30 c, as shown by the arrow B 1. It enters the inside of the detection unit 14 and is introduced into the smoke detection space 25.

Further, as shown by the arrow B2, the smoke entering from the smoke inlet 4 on the left side of the white outer cover 3 is
Through the smoke inlet 27b and the smoke inlet 30b. In this case, even if the blowing pressure F of the backflow caused by the stop of the air conditioning acts on the space 33a through the opening hole 6 as shown by the arrow G1, the opening area is limited by the incorporation of the locking piece 5, so that the backflow is prevented. Can be suppressed.

Therefore, even if the air blows back pressure F due to the stoppage of air conditioning, smoke is introduced into the smoke detection space 25 as indicated by arrows B1 and B2. The smoke introduced into the smoke detection space 25 includes a smoke inlet 30a and a smoke inlet 27a as indicated by an arrow C1.
Through the smoke inlet 4 on the right side of the white outer cover 3. Also, as indicated by arrow C2, the smoke detection space 25
The smoke introduced into the smoke outlet 32b and the smoke outlet 28a
Through the space 33b to the outside through the smoke inlet 4 on the right side of the white outer cover 3.

As described above, even if there is a blowout pressure F due to the backflow, the backflow can be suppressed because the opening area of the opening hole 6 is limited, and the influence of the stop of the air conditioning can be suppressed to the minimum. . FIG. 12 is an explanatory diagram of the smoke inflow characteristics in the front-back direction. 12, it is assumed that the smoke flows from the front side of the white outer cover 3 to the rear side as indicated by an arrow H. At this time, the smoke flows in from the smoke inlet 4 of the white outer cover 3 as indicated by an arrow I. Inside the white outer cover 3, the protruding introduction part 16 of the smoke detection part 14 which forms the front and rear partition wall 29 is located, and the labyrinths 26c to 26
The gas enters from the smoke inlets 30 a to 30 c partitioned by e and is guided to the smoke detection space 25 by the partition wall 29. Smoke detection space 25
Introduced through the white outer cover 3 as shown by the arrow J into the smoke inlets 30a to 30c on the opposite side of the partition wall 29.
Is discharged outside through the smoke inlet 4.

[0049]

As described above, according to the present invention, since the sensor main body case and the smoke detector are formed of the same low-brightness material, light entering from the lower part of the sensor main body case is absorbed and attenuated. Since the light does not reflect off the smoke detecting section, the labyrinth structure can be simplified, and the smoke inflow characteristics can be improved.

Further, since both the sensor body case and the smoke detector are made of a material having low brightness, that is, a black or gray material, the inside of the sensor body case in which the smoke detector is housed is sufficiently dark. Light that has entered from the outside is absorbed and attenuated by the inner surface of the sensor body case, so that reflection on the smoke detector can be sufficiently suppressed. Sensor body case 2
Because the intrusion of light due to reflection from the inner surface of the smoke detector can be reduced, the labyrinth structure for shading provided in the smoke inflow passage of the smoke detector can be simplified, and as a result, the smoke inflow characteristics can be improved. it can.

Further, since the sensor case main body and the smoke detecting portion are made of the same black or gray material, the sensor case main body is divided into two parts in the left-right direction, and the inside of one sensor main body case is formed. The smoke detector can be integrally molded, and the number of assembling steps and cost can be reduced. In addition, when installed in a slit-shaped opening in the system ceiling, the conventional fire detector has a bright color such as white or beige, so the sensor case body in the ceiling can be seen through the slit-shaped opening. It is not preferable in terms of the design of the building, but in the present invention,
Since the sensor body case located behind the ceiling is black,
Almost invisible from the slit-shaped opening, eliminating the design problem of the building.

[Brief description of the drawings]

FIG. 1 is a three side view of an embodiment of a fire detector of the present invention.

FIG. 2 is an explanatory view of a mounting state of a fire detector according to the present invention.

FIG. 3 is an exploded view of a main body case and an internal printed circuit board of the fire detector according to the present invention.

FIG. 4 is an exploded view of another embodiment in which the smoke detector is integrated into the fire detector main body case.

FIG. 5 is an explanatory view of an internal structure in which one of the covers of FIG. 1 is removed.

FIG. 6 is an explanatory diagram of a smoke detector provided on the printed circuit board of FIG. 3;

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is a sectional view taken along line BB and CC of FIG. 6;

FIG. 9 is an explanatory diagram of smoke inflow characteristics during an air conditioning operation.

FIG. 10 is an explanatory diagram of smoke inflow characteristics when air conditioning is stopped.

FIG. 11 is an explanatory diagram of smoke inflow characteristics at the time of backflow blowing due to the stop of air conditioning.

FIG. 12 is an explanatory diagram of smoke inflow characteristics in the front-rear direction.

FIG. 13 is a schematic explanatory view of a related art.

[Explanation of symbols]

 1: Fire detector 2: Detector body case 3: White outer cover 4, 27, 30: Smoke inlet 5: Locking piece 6: Opening hole 7: T-angle member 8, 9: Mounting bracket 10: Ceiling board 11 , 12: Black case 36: Slit-shaped opening

Claims (2)

(57) [Claims] 1. A fire detector for detecting smoke due to a fire, which is attached to a suction opening of a slit-shaped air conditioner of a system ceiling, wherein a downwardly facing cover mounting opening is provided with a slit opening of the system ceiling. A sensor body case located near the ceiling and located in the vicinity, mounted on the cover mounting opening of the sensor body case so as to protrude below the ceiling surface, so that smoke from all directions around the sensor can flow in An outer cover having a smoke inlet formed therein, and a smoke flow in all directions around the outer cover, which is incorporated in the sensor body so that a part thereof is located at a position protruding from a ceiling surface in the outer cover. A smoke detector formed with a smoke inlet corresponding to each of the inlets, wherein the sensor body case is made of a black or gray material that is inconspicuous when viewed through the slit-shaped opening of the system ceiling. The smoke detector, wherein the smoke detector is also formed of the same black or gray material of the sensor body case. 2. A fire detector according to claim 1, wherein each of said sensor body case and said smoke detector is made of a black synthetic resin material.