JPH10162268A - Fire sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely sense the occurrence of fire without being affected by an air current from the ceiling in the detection output of physical quantity change for detecting the generation of fire by providing an air current shielding means for shielding the inflow of air current from a constructive material side through hole inserting an external wife to the fire sensor. SOLUTION: The external wire is inserted through an opening 21a corresponding to an external wire inserting hole formed at the central part of base body 21, and a shield panel 24 is provided corresponding to the air current shielding means for shielding the inflow of air current from the constructive material side through hole inserting the external wire to the side of smoke sensor. This shield panel 24 has a crossing-shaped opening part 24a for inserting the external wire at the almost center of sheet shape composed of synthetic rubber material, for example, having elasticity so as to easily insert the external wire in a different outer diameter size and to shield the inflow of air current from the constructive material side through hole as much as possible, and is formed while having an outer diameter form almost similar to the opening 21a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fire detector.

[0002]

2. Description of the Related Art Recently, a self-fire alarm system using an analog sensor capable of reliably detecting the occurrence of a fire in a room and reducing the number of non-fire alarms has been proposed. This self-fire alarm system is an analog sensor that outputs a continuous analog signal of the fire situation, ie, smoke density change, temperature change, etc., in order to reduce non-fire reports and to initiate fires earlier. Depending on the output level by the sensing signal from the "fire forecast", "fire alert",
It also reports "interlocking information" that interlocks smoke and smoke prevention equipment.

The above-mentioned self-fire alarm system uses an analog smoke detector which outputs an analog signal of the smoke density as shown in FIG. 4, for example. This analog smoke detector
A smoke detection chamber (not shown) for detecting the generation of smoke, which corresponds to detection means for detecting the occurrence of fire, and a connection means to which a smoke detection circuit which is an electric circuit forming the detection means is connected. And a locking piece 22 corresponding to a locking means in which a connecting portion 22a for connecting an external electric wire and a locking portion 22b for locking the sensor head 1 are formed. And a base 2 in which an electric wire insertion hole 21a for inserting an external electric wire connected to the connection portion 22a is formed.

[0004] As shown in FIG. 4B, the sensor head 1 has a cylindrical sensing unit 11 and a sensor head 1.
And a base 12 formed with an insertion hole (not shown) for inserting and locking the sensing unit 11 which is a sensing portion of the base unit 12. Are provided with connection springs 13, 13 which correspond to the connection means and engage with the locking pieces 22, 22 provided on the base 2. Then, the base 2 and the sensor head 1 are relatively rotated with respect to each other in a predetermined direction, so that the base 12 and the base body 2 are rotated.
1, a locking piece 22 detachably engaged,
22 and are electrically connected.

[0005] As shown in FIG.
A smoke introduction portion G is formed by an insect net 11c, not shown, provided on a unit body 11a having a labyrinth structure for preventing external light from entering the smoke sensing chamber C. And, to the smoke particles D introduced from the smoke introduction section G,
An infrared LED element T as a light projecting means for projecting infrared light, a condenser lens L for condensing infrared light reflected from the smoke particles D, and a condenser lens It has a well-known photoelectric smoke detection structure formed with a photodiode chip R as light receiving means for receiving infrared light condensed through L. The photodiode chip R is mounted on one surface of a printed circuit board B on which the infrared LED elements T are mounted, connected to circuit components forming a smoke detection circuit on the substrate by wire bonding wiring as appropriate, and transmits infrared light. The surface is sealed and protected by a possible sealing material. The printed circuit board B is provided with connection pieces P, P for supplying power to the smoke detection circuit formed on the board and obtaining a signal output.
a and is protected by a unit cover 11b corresponding to a case. Then, the infrared LED element T is provided in the smoke sensing room C whose surroundings are protected by the insect net 11c.
Is formed, and the amount of smoke particles D flowing into the airflow and flowing in is determined as a change in the amount of reflected infrared light. It is detected by the photodiode chip R as an electric analog signal.

[0006] In the sensing unit 11, the smoke introduction portion G is locked by pressing the edge portion of the insect repelling net 11c by the cap 11d, and the unit body 11a is integrally formed with a unit locking piece 11e. ing. Then, one end of each of the connection pieces P, P is inserted into and fixed to a through hole formed in the unit cover 11b by soldering or the like.
4 and the connection springs 13 provided on the base 12 are fixedly connected to each other and electrically connected to each other.
2, the unit locking pieces 11e are mechanically locked by locking means formed on the base 12 to form the sensor head 1.

[0007] The above-mentioned smoke detector is mounted directly on a building material or on a ceiling in a room or via a switch box. First, the base 2
The signal wiring is inserted into the central opening 21a of the base body 21 and connected to the engaging pieces 22, 22 by terminal screws 23, 23, and is fixed to a predetermined mounting portion of the building material by the mounting holes 21b, 21b. . Next, the sensor head 1 is mounted on the base 2 with the base 12 attached thereto, and is rotated relative to each other in a predetermined direction so as to be engaged and fixed as shown in FIG. When the sensor main body 2 is detached from the base 1, the sensor main body 2 can be rotated in a direction opposite to the direction in which the sensor main body is engaged to be detached. In this smoke detector, a heat detector is formed by changing the sensing unit 11 from, for example, a photoelectric smoke detection structure to a heat detection structure that detects a temperature change of a thermistor or the like as a resistance change. I can do it.

[0008]

However, there is generally a temperature difference between the ceiling and the room and a pressure difference. Therefore, when there is an opening in the ceiling surface, airflow is likely to occur through the opening, and even in the above-described installation state, when the pressure behind the ceiling is higher than that of the room, the external electric wire is penetrated as shown in FIG. From the building material side through hole H toward the room, an airflow F passing through an annular gap d formed on a contact surface between the sensing unit 11 and the base 12 is generated. As a result, due to the influence of the airflow F, the change in the smoke density from the analog smoke detector, that is, the change in the continuous change amount of the smoke particles D may be different from the change in the initial state of the fire. In addition, even in the case of the configuration of the heat sensor, the correct transition of the heat change may not be detected due to the influence of the hot airflow from above the ceiling. Further, the connection piece P provided on the printed circuit board B and the insertion hole (not shown) provided in the unit cover 11b for inserting the connection piece P are inserted with a gap. An airflow was generated from the gap toward the smoke sensing chamber C or the internal circuit having the sensing unit.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for detecting a change in physical quantity for detecting the occurrence of a fire under the influence of airflow from above and below a ceiling. Accordingly, it is an object of the present invention to provide a fire detector capable of reliably detecting the occurrence of a fire.

[0010]

According to a first aspect of the present invention, there is provided a fire detector, comprising: a detecting means for detecting the occurrence of a fire; and a connection to which an electric circuit forming the detecting means is connected. A sensor head having means, a connecting portion for connecting the external electric wire, and an external electric wire connected to the connecting portion having a locking means formed with a locking portion for locking the sensor head. A base formed with an electric wire insertion hole for inserting the electric wire, wherein the electric wire insertion hole is configured to detect an airflow from the building material side through hole through which the external electric wire is inserted and the external electric wire is penetrated. Airflow shielding means capable of shielding the inflow to the vessel side is provided. This allows
Airflow from the building material side through hole is blocked by the airflow shielding means in the external electric wire insertion hole.

Further, in the fire detector according to the second aspect, the shielding means according to the first aspect is formed such that a cutout portion through which an external electric wire is inserted is formed substantially at the center of a sheet material having elasticity. Thereby, the external electric wire pushes the incised portion and is inserted.

According to a third aspect of the present invention, there is provided a fire detector, comprising: a sensor head having detection means for detecting the occurrence of a fire; and connection means to which an electric circuit forming the detection means is connected; Having a connecting portion for connecting the sensor and a locking means formed with a locking portion for locking the sensor head, the base having an electric wire insertion hole for inserting an external electric wire connected to the connecting portion. Wherein the electric circuit and the connection means of the sensor head are connected by inserting a connection piece into a through hole formed in the case, wherein the through hole prevents an air flow from flowing into the inside of the sensor head. A through hole shielding means capable of shielding is provided. As a result, the airflow does not enter the inside of the sensor head.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a fire detector according to the present invention will be described below with reference to FIGS.

FIG. 1 is a perspective view of a smoke detector as an embodiment of a fire detector as viewed from below a base. FIG.
FIG. 3 is an explanatory view showing a side cross section of the above. FIG. 3 is a partial view showing a through hole shielding means, which is a main part of the above.

This smoke detector is an analog smoke detector similar to the conventional example, and as shown in FIG. 2, corresponds to a detection means for detecting the occurrence of a fire, and is a smoke detection chamber for detecting the generation of smoke. (Not shown), a sensor head 1 having a connection means to which a smoke detection circuit which is an electric circuit forming the detection means is connected, and a connection portion 22a for connecting an external electric wire.
And an electric wire for inserting an external electric wire connected to the connecting portion 22a, having locking pieces 22, 22 corresponding to locking means in which a locking portion 22b for locking the sensor head 1 is formed. And a base 2 having an insertion hole 21a formed therein. This is different from the conventional example only in the structure of a part of the sensor head 1 and the base 2, and the other parts are the same, and the detailed explanation of the inside is omitted.

The base 2 is different from the conventional example in that the external wire is inserted into the opening 21a corresponding to the external wire insertion hole formed in the center of the base body 21 and the external wire is penetrated. The point is that a shielding plate 24 corresponding to an airflow shielding means capable of shielding the inflow of the airflow from the material side through hole to the smoke detector side is provided. This shielding plate 24
Is made of an elastic synthetic rubber material or the like so that it can be easily inserted into external electric wires having different outer diameters and shield the airflow from the building material side through hole H as much as possible. It has a cross-shaped cutout 24a into which an external electric wire is inserted at substantially the center of a sheet-like shape, and is formed to have an outer diameter substantially similar to the above-mentioned opening 21a. And the opening 21
a at a predetermined position, an adhesive is applied to the periphery and the opening 21 is formed.
It is stuck so as to cover a.

The sensor head 1 differs from the conventional example in that the airflow into the sensor head is formed in a through hole 11f formed in a unit cover 11b corresponding to the case of the sensor head and penetrating through the connecting pieces P, P. Is provided with a through-hole shielding means capable of shielding the inflow of air. As shown in FIG. 3, the through hole shielding means includes connection plates 14, 14 fixed to connection springs 13, 13 engaged with locking pieces 22, 22 provided on the base 2, and the sensor head 1. Are provided so as to surround the through holes 11f penetrating through the connection pieces P, P for connecting to the printed circuit board B, which is an electric circuit inside. And in this case, O-ring 1
5 are provided. The O-ring 15 is formed of a silicon rubber material or the like having elasticity and heat resistance, and is inserted through the connection pieces P, P when soldering the connection pieces P, P to the connection plates 14, 14. Is arranged. Therefore, by performing the soldering while pressing the connection plate 14, the periphery of the through hole 11f can be reliably shielded.

The above-mentioned smoke detector is also attached directly to a building material or to a ceiling in a room or via a switch box. When mounting, the signal wiring is cut into the cutout 24 of the shielding plate 24 at the center of the base body 21.
Then, the sensor head 1 is fixed to a predetermined mounting portion of the building material through the mounting holes 21b, 21b.

According to the smoke detector described above, the air flow from the building material side through hole H is cut off by the shielding plate 24 in the external electric wire insertion hole 21a, and the fire current is affected by the air flow from behind the ceiling. The detection output of the physical quantity change such as the amount of the smoke particles D for detecting the occurrence is not affected, so that the occurrence of the fire can be reliably detected. Further, since the external electric wire is pushed through the cutout portion 24a and inserted, the airflow can be similarly blocked for external electric wires having different outer diameters. In addition, since the airflow does not enter the inside of the sensor head 1, the airflow to the smoke sensing chamber C does not pass. as a result,
The detection output of the change in the smoke density is not affected by the influence of the airflow from above the ceiling, so that the occurrence of a fire can be reliably detected.

Although the smoke detector has been exemplified and described in the above embodiment, the present invention is not limited to the smoke detector itself, and may be, for example, a heat detector. Further, in the above-described embodiment, the fire detector has been described as having the airflow shielding means and the through-hole shielding means, but the present invention is not limited to only the fire detector, for example, has only the airflow shielding means. It may be something.

[0021]

In the fire detector according to the first aspect, the airflow from the through hole on the building material side is cut off by the airflow shielding means in the insertion hole for the external electric wire.
The detection output of a change in physical quantity such as the amount of smoke particles for detecting the occurrence of a fire is not affected, so that the occurrence of a fire can be reliably detected.

The fire detector according to the second aspect has the same effects as those of the first aspect. In addition, since the external electric wire is inserted by pushing the incised portion, the external electric wire can be connected to external electric wires having different outer diameters. Similarly, the airflow can be blocked.

In the fire detector according to the third aspect, since the airflow does not enter the inside of the sensor head, the detection output of the change in the smoke density is not affected by the influence of the airflow from above and below the ceiling. It is possible to reliably detect the occurrence of a fire.

[Brief description of the drawings]

FIG. 1 is a perspective view seen from below a base of a smoke detector which is a main part of an embodiment of a fire detector according to the present invention.

FIG. 2 is an explanatory view showing a side cross section of the above.

FIG. 3 is a partial view showing a through-hole shielding means which is a main part of the same.

4A and 4B are perspective views showing a conventional smoke detector, wherein FIG. 4A shows a separated state viewed from below, and FIG. 4B shows a sensor head viewed from above.

FIG. 5 is an explanatory diagram of a sensing unit of the smoke detector. +

FIG. 6 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sensor head 12 Base 12a Through-hole 13 Connection spring (measured means) 15 O-ring (through-hole shielding means) P Connection piece 2 Base 21a Opening (external wire insertion hole) 22 Locking piece (locking means) 24 Shield plate (airflow shielding means) 24a incision H Construction material side through hole

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[Procedure amendment]

[Submission date] December 2, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (3)

[Claims] 1. A sensor head having a detecting means for detecting the occurrence of a fire and a connecting means to which an electric circuit forming the detecting means is connected, a connecting part for connecting an external electric wire, and the sensor head. A base having an electric wire insertion hole for inserting an external electric wire to be connected to the connection portion, the base having an engagement means having an engagement portion for stopping, and The electric wire insertion hole is provided with an airflow shielding means that can insert an external electric wire and shield airflow from a construction material side through hole through which the external electric wire penetrates into the fire detector side. sensor. 2. The fire detector according to claim 1, wherein said shielding means has elasticity in which a cutout portion through which an external electric wire is inserted is formed substantially at the center of a sheet. 3. A sensor head having detecting means for detecting the occurrence of a fire and a connecting means to which an electric circuit forming the detecting means is connected, a connecting part for connecting an external electric wire, and the sensor head. A base having an engagement portion formed with an engagement portion for stopping and having an electric wire insertion hole for inserting an external electric wire connected to the connection portion, the electric circuit of the sensor head. And a connecting means connected to the through hole formed in the case by inserting a connecting piece into the through hole, wherein the through hole is provided with a through hole shielding means capable of blocking inflow of airflow into the sensor head. A fire detector.