JP2562895Y2 - Flame detector - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detector, and more particularly, to an ultraviolet detector tube (Ultra Violet Detective Tube).
.., Hereinafter referred to as a UV tube) and a flame detector that detects a fire by detecting ultraviolet rays emitted from the flame.

[0002]

2. Description of the Related Art FIG. 9 is an explanatory view of the structure of a conventional flame detector, and FIG. 10 is a sectional view of a main part of FIG. 9 and 10, 2 is a main body, 3 is a cover, 4 is a base, and 6 is a printed circuit board. Reference numeral 20 denotes a partition wall of the main body 2, reference numerals 21 and 22 denote a plurality of fixing screws and terminal pieces, respectively, and reference numeral 32 denotes a sensing window provided at the center of the cover 3. 7 is a UV tube, 70 is a glass tube in the UV tube 7, 71 and 72 are lead legs, and 8 is a buffer material.

In the conventional flame detector as described above, the lead legs 71 and 72 led out of the UV tube 7 are bent at a right angle near the lead-out end, inserted into a through hole of the printed circuit board 6, and the tip is soldered. Is done. The UV tube 7 is supported by the bent lead legs 71 and 72 in parallel with the printed circuit board 6, and the middle of the glass tube 70 is in contact with the buffer material 8. The printed circuit board 6 to which the UV tube 7 is attached is the main body 2
The main body 2 to which the cover 3 is fixed is connected to a receiving blade 42 as an external terminal. A high voltage is applied to the electrodes of the UV tube 7 of the flame detector mounted on the ceiling in the operating state. By any chance
When a fire occurs, ultraviolet rays are projected from the flame and the sensing window 32
UV light is applied to the UV tube 7 through the. UV is UV
When entering the tube 7, a discharge phenomenon occurs due to the photoelectric effect,
This discharge current is taken out by an electronic circuit, and an alarm or the like of a fire alarm is issued.

[0004]

As described above, in the conventional flame detector, a high voltage is applied to the electrode of the UV tube 7 in the operating state. Accordingly, the surface of the glass tube 70 of the UV tube 7 is charged with static electricity, and dust and dirt are likely to adhere thereto. If dust or dust adheres to the surface of the glass tube 70, transmission of ultraviolet rays is hindered, and the detection sensitivity of the UV tube is reduced. Therefore, the surface of the glass tube is periodically cleaned using a cloth impregnated with alcohol or the like. Cleaning is performed with the stepladder reaching the ceiling on the floor or removed from the ceiling, which is an enormous task for buildings with many flame detectors. In addition, when dust and dirt attached to the glass tube 70 absorb moisture,
Condensation may form on the attached part. UV tube 7 due to condensation
When the insulation between the terminals of the lead legs 71 and 72 is reduced, there is a problem that not only the insulation is deteriorated and the sensitivity is further reduced, but also a short circuit accident may be caused.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the conventional apparatus as described above, and it is easy to clean the glass tube of the UV tube and to reduce the detection sensitivity accompanying the adhesion of dust and dust. It is intended to realize a flame detector without any.

[0006]

According to the present invention, there is provided a printed circuit board comprising a main body, a cover fixed to the main body and having a sensing window penetrating therethrough, wherein electronic parts are mounted in the case,
In a flame detector equipped with a UV tube connected to a printed circuit board and allowing a glass tube to be seen through a sensing window of a cover, a recess recessed inward at the center of the cover, and a sensing window penetrating the center of the recess, The flame detector has a concave notch on both sides of the sensing window with a continuous flat portion.

[0007]

[Function] When the body fitted with the cover is joined to the base,
A flame detector in which the glass tube of the UV tube is exposed from the sensing window toward the floor is attached to a ceiling or the like. A high voltage is applied to the electrodes of the UV tube of the flame detector mounted on the ceiling or the like in the operating state. If a fire occurs, ultraviolet rays are projected from the flame, and the UV tubes are irradiated through the sensing window. When ultraviolet rays enter the UV tube, a discharge phenomenon occurs due to a photoelectric effect, and this discharge current is taken out by an electronic circuit, and an alarm or the like of a fire alarm is issued. At the time of periodic inspection, the glass tube is cleaned together with the operation test. On both sides of the sensing window where the glass tube of the UV tube is exposed, a concave portion provided on the concave side is formed. Therefore, dust and dirt adhering to the surface of the glass tube can be easily wiped off by rubbing with a cloth or the like, so that the surface of the glass tube can be kept clean and the detection sensitivity can be prevented from lowering.

[0008]

1 is a top view of an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a bottom view of FIG. 1, FIG. 4 is an enlarged cross-sectional view of FIG. 3, and FIG. FIG. 4 is an enlarged Y-Y cross-sectional view of FIG. In the drawings of the present invention, portions having the same functions as those of the conventional device are denoted by the same reference numerals, and the description thereof may be duplicated.

1 to 5, reference numeral 1 denotes a case of a flame detector. The case 1 is formed by resin molding. 2 is a case main body, and 3 is a cover. The main body 2 is formed in a thin cylindrical shape provided with a partition wall 20 for separating the upper and lower portions near the upper portion, and the cover 3 is formed in a shallow bowl shape. Reference numeral 21 denotes four fixing screws inserted into the main body 2;
Is a terminal piece screwed to each fixing screw 21 and fixed to the upper surface of the main body 2, and 23 is a mounting stud into which the fixing screw 21 is inserted. The fixing screw 21 and the terminal strip 22 constitute an input / output terminal.

Reference numeral 31 denotes a conical recess which is recessed inward at the center of the cover 3, and reference numeral 32 denotes a rectangular sensing window provided through the center of the recess 31. Numeral 33 denotes a flat portion formed by a concave notch 34 on the concave portion 31 side of the sensing window 32, and 35 denotes a holding claw. The flat portions 33 are provided on both sides of the long side of the sensing window 32, and the holding claws 3
Reference numeral 5 denotes three pairs of claws protruding inside the long side of the sensing window 32 and provided symmetrically with each other. The length of the long side of the sensing window 32 is substantially equal to the length L of the cylindrical portion 70b of the UV tube 7 described later. Also, 36 and 37 are square-shaped pedestals formed on the inner surface side of the cover 3 along the short side of the sensing window 32, 38 is a circular display window penetrating the cover 3, and 39 is a reinforcing window. Fins.

4 is a base, 5 is a lead wire, 6 is a printed circuit board, 7 is a UV tube, and 81 and 82 are cushioning materials. 41 is an electric wire insertion hole provided in the base 4, and 42 is a receiving blade corresponding to the terminal piece 22. The base 4 is attached to, for example, a ceiling in a room by a mounting bracket such as a mounting screw (not shown), and the receiving blade 42 sandwiches the terminal piece 22 to electrically connect the main body 2 to the base 4 and mechanically fixes the base 2. I do. The lead wire 5 is composed of two lead wires 51 using a slightly longer stranded wire,
52 is used, and one end is soldered to the lead legs 71 and 72 of the UV tube 7. The end surfaces of the stranded wires at the other ends of the lead wires 51 and 52 are solidified by solder and are detachably connected to a socket 61 of a through hole provided on the printed circuit board 6. Reference numeral 62 denotes an L provided on the printed circuit board 6.
ED and 63 are inductance elements, and 64 is a resistance element. The LED 62 is provided at a position corresponding to the display window 38 of the cover 3. The cushioning material is large 81 and small 8
It is made of, for example, a sponge that has two cushion functions. Large cushioning material 81 and small cushioning material 82
Are bonded to the receiving bases 36 and 37 of the cover 3 by, for example, an adhesive.

Reference numeral 70 denotes a glass tube of the UV tube 7, reference numerals 71 and 72 denote lead legs bent on the same plane, and reference numerals 73 and 74 denote cathodes and anodes constituting discharge electrodes. As shown in FIGS. 7 and 8, the glass tube 70 is composed of a solid flat portion 70a, a hollow cylindrical portion 70b, and a pointed head 70c. The cathode 73 is rectangular and has a wide photocathode, and the anode 74 is formed by forming a conductive wire substantially in the shape of a "". Then, a light receiving surface is formed by a surface formed by the opposed cathode 73 and anode 74,
It is enclosed in the cylindrical portion 70b together with the special gas. W is a ceiling.

[0013] The flame detector of the present invention having the above-described structure is as follows.
For example, it is assembled as follows. Electronic components such as the LED 62, the inductance element 63, and the resistance element 64 are soldered and mounted at predetermined positions on the printed circuit board 6. The printed circuit board 6 on which the electronic components are mounted is inserted into the main body 2, and the fixing screw 21 is inserted into the stud 23 and screwed into the terminal piece 22 applied to the outlet side to fix. With the same operation, the printed circuit board 6 is firmly fixed to the partition wall 20 in the main body 2 using four fixing screws 21. Subsequently, the UV tube 7 to which the two lead wires 51 and 52 are already connected is taken out, and the glass tube 70 is inserted while the holding claw 35 is slightly opened while being opened from the inside of the cover 3. Works and the flat part 70a and the pointed head 70c
, And are pressed onto the receiving tables 36 and 37 via the small cushioning material 82. As a result, the cylindrical portion 70b of the UV tube 7 is
The cover 2 is exposed to the concave portion 31 side and detachably attached to the cover 3. The exposed state of the UV tube 7 is shown in FIGS. In this case, the angle of the light receiving surface of the UV tube 7 with respect to the concave portion 31 can be adjusted by rotating the UV tube 7 elastically held by the holding claws 35 about an axis. By this angle adjustment, the light receiving surface is set accurately toward the horizontal floor.

After mounting the UV tube 7, two lead wires 51,
When the tip of 52 is inserted into the socket 61 through the through hole of the printed circuit board 6, the UV tube 7 is connected to the printed circuit board 6. Thereafter, the cover 3 is integrally fitted to the main body 2 from below by an engagement mechanism (not shown).
The main body 2 integrated with the cover 3 is fixed to the ceiling W, pressed against the base 4 connected to the electric wire / signal line, and then slightly rotated to be attached. The flame detector in which the main body 2 with the cover 3 fitted thereto is thus attached to the base 4 is attached to the ceiling W or the like with the light receiving surface of the UV tube 7 facing the floor, and the flame detector can be operated. Is set to.

Here, when a fire occurs, ultraviolet rays are projected from the flame, and a detection window 32 of a flame detector attached to the ceiling W is provided.
UV light is applied to the UV tube 7 through the. On the other hand, a cathode 73 sealed in the UV tube 7 and having sensitivity to only ultraviolet rays
Between the anode and the anode 74 at all times or intermittently
A high voltage of about V is applied. And the cathode 7
When ultraviolet rays are incident on the pole surface of No. 3, photoelectrons are emitted by the photoelectric effect, and a discharge phenomenon occurs between the cathode 73 and the anode 74. The cathode 73 and the anode 7
The discharge current generated between the four is taken out by an electronic circuit, the occurrence of a fire is sensed, and an alarm of a fire alarm is issued.

In general, the air in a building is convected by air.
A circulating airflow including dust is constantly generated in the room. For this reason, since a high voltage is used for the UV tube 7 as described above, static electricity is charged to the glass tube 70 and dust adheres. Since the adhered dust hinders the transmission of ultraviolet rays, cleaning is performed together with sensitivity adjustment at the time of regular maintenance and inspection. If the attached dust contains moisture, it induces dew condensation and causes insulation failure.

In the above embodiment, the conical recess 31 is used.
Part 3 formed as a concave notch 34 penetrating through the center of
A rectangular sensing window 32 sandwiched between 3 is provided, and a glass tube 70 of the UV tube 7 is exposed from the sensing window 32. Moreover, the glass tube 70 is elastically held by the holding claws 35 formed of a plurality of symmetric claws. Therefore, the cleaning of the glass tube 70, which is periodically performed, is easy and not only reaches the corners, but also the inclination of the cleaning operation is not changed, and the electrical connection is not hindered. Also, if necessary, remove the cover 3 from the main body 2,
Pull out the lead wires 51 and 52 from the socket 61 and UV
The tube 7 can be removed from the cover 3 and wiped.

In the embodiment of the present invention described above, the case where the long side of the rectangular sensing window 32 is sandwiched by the flat portion 33 formed by the concave portion 34 on the side of the conical concave portion 31 has been described. However, a concave notch may be provided on the short side, and the shape of the sensing window 32 does not necessarily need to be formed in a rectangular shape. Further, the concave portion may be formed in a spherical shape or a planar shape.

[0019]

According to the present invention, a case is constituted by a main body and a cover locked to the main body and penetrating a sensing window, a printed circuit board having electronic components mounted in the case, and a cover connected to the printed circuit board. In a flame detector equipped with a UV tube that allows a glass tube to be seen through a sensing window, a concave portion that is recessed inward at the center of the cover, and a sensing window is provided at the center of the concave portion,
A flame sensor was formed in which a concave portion having a continuous flat portion was formed on both sides of the sensing window. As a result, even though the glass tube of the UV tube is exposed from the sensing window penetrating the concave portion, it is easy to wipe, and the cleaning operation is easy and reliable. Therefore, there is no unwiped residue, and the surface of the glass tube can be kept clean, so that a decrease in sensitivity can be prevented.

Therefore, according to the present invention, it is possible to provide a flame detector which can thoroughly maintain cleaning and keep the glass tube clean at all times, does not lower the detection sensitivity of ultraviolet rays, and is easy to maintain. Can be.

[Brief description of the drawings]

FIG. 1 is a top view of an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a bottom view of FIG. 1;

FIG. 4 is an enlarged sectional view taken along line XX of FIG. 3;

FIG. 5 is an enlarged YY side view of FIG. 4;

FIG. 6 is a sectional view of a main part of the embodiment of the present invention.

FIG. 7 is a top view of a UV tube.

FIG. 8 is a bottom view of the UV tube.

FIG. 9 is a diagram illustrating a configuration of a conventional flame detector.

FIG. 10 is a sectional view of a main part of a conventional flame detector.

[Explanation of symbols]

 2 Body 3 Cover 5 Lead wire 6 Printed circuit board 7 UV tube 31 Concave part 32 Sensing window 33 Flat part 34 Depressed part 35 Holding claw (holding mechanism) 36, 37 Receiving stand 51, 52 Lead wire 61 Socket 70 Glass tube 70a Flat part 71, 72 Lead leg 73 Cathode 74 Anode 8, 81, 82 Buffer material (contact member) W Ceiling

Claims (1)

(57) [Scope of request for utility model registration] 1. A case comprising a main body and a cover locked to the main body and having a sensing window penetrating therethrough, a printed circuit board having electronic components mounted in the case, and the cover connected to the printed circuit board. A flame detector provided with a UV tube that allows a glass tube to be seen through a sensing window, wherein a recess recessed inward at the center of the cover, and the sensing window is provided at the center of the recess,
A flame detector characterized in that a recessed portion having a continuous flat portion is formed on both sides of the window .