JP3191188B2 - Thermoelectric fire 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 thermoelectric fire detector having a thermal and photoelectric sensing function.

[0002]

2. Description of the Related Art In a conventional thermoelectric fire detector, a housing is formed by fitting a body and a cover, a printed circuit board is disposed on a bottom surface of the body, and an opening is formed on an upper surface of the housing. Is formed, and the optical chamber base is arranged in this opening,
A light projecting element and a light receiving element are arranged on the optical bench so that the optical axis is substantially parallel to the optical chamber base, and the upper plate with labyrinth is covered so as to cover the optical chamber base through the upper opening of the housing. ,
The outer periphery of the upper plate with labyrinth is covered with an insect net.
Then, a lead wire of the thermal element is fixed to the upper plate with an adhesive tape, and the thermal element is projected from a through hole of the cover.

[0003]

In the conventional thermoelectric fire detector, since many screws are used as fixing means, assembly and disassembly are extremely troublesome and time-consuming. or,
The optical chamber base in the opening of the housing is separated from the printed circuit board via the L-shaped bent leg to protect electric circuit components on the printed circuit board. The height of the housing increases accordingly. Therefore, when making the sensor thinner, it is conceivable to lower the height of the dark room,
This is not preferable because the performance of the sensor is deteriorated. Therefore, the height of the dark box is unavoidably set to the normal height. Therefore, the sensor itself becomes thick. In addition, it is troublesome to fix the thermal element at a predetermined position while aligning, and even if the thermal element is fixed at a predetermined position with an adhesive tape, if the lead wire is pulled, the thermal element moves and shifts in position. This makes accurate fire monitoring difficult.

[0004] In view of the above circumstances, it is an object of the present invention to easily set a thermal element at a predetermined position and maintain the position.

[0005]

According to the present invention, there is provided a holder having a positioning groove provided at a central portion of an upper surface of an optical bench cover;
A lead wire guide wall provided on the optical bench cover and extending from the holder to the edge of the cover; and a plurality of projections fitted into the positioning groove, which fits into the holder and is provided with the optical bench cover. A support sandwiched by the protective cover; a thermosensitive element provided upright on the support and having a lead wire connected to the printed circuit board through the guide wall; and an insertion hole provided in a top plate of the protective cover. And to achieve the above object.

[0006]

After placing the optical bench cover on the upper surface of the optical bench, the support of the thermosensitive element is fitted to the thermosensitive element holder of the optical bench cover, and the lead wire is fitted to the lead wire guide groove. afterwards,
The support is fitted into the insertion hole of the top plate, and the optical bench cover is covered with a protective cover. The protective cover is engaged with the main body while pressing the support and the optical bench cover, and fixed.

[0007]

An embodiment of the present invention will be described with reference to the accompanying drawings. The main body 1 is configured as shown in FIG. On the upper surface 1a of the main body 1, a support post 3 having an insertion hole 2 and a protruding post 9 for positioning the printed circuit board 10 are protruded, and a locking portion 4 is provided on the outer peripheral portion of the main body 1. Is provided. An annular groove 1R for drainage as shown in FIG. 2 is formed on the lower surface 1b of the main body 1, and the annular groove 1R communicates with a drainage hole 1H formed on the outer peripheral edge of the main body 1. . A blade fitting 5 as a conductive connection fitting shown in FIG. 12 is fixed to the lower surface 1b of the main body 1. The blade fitting 5 includes a fixed portion 5a and a blade portion 5b. In this fixed part 5a,
A screw hole 7 to be screwed with the terminal screw 6 shown in FIG. 9 is provided. Further, the blade portion 5b is engaged with a blade receiving member as a conductive connecting member of a base (not shown).

The printed circuit board 10 is configured as shown in FIG. On the upper surface 10a of the printed circuit board 10,
Cross-shaped shield part 11 and check terminal 12 having a large area
And an optical table mounting part 13 and an indicator lamp 14 formed on the shield part 11. A lower surface 10b of the printed circuit board 10 is provided with a surface mount type electric circuit component 10e. Also, the optical board 4 is provided on the printed circuit board 10.
0 is provided with a through hole 17 through which the hook 48 passes.
On the periphery of the insertion hole 17 on the b side, the locking portion 1 of the hook 48 is provided.
7a is provided.

The optical table holder 20 is configured as shown in FIGS. The optical bench holder 20 is formed in an L shape, and a light emitting element housing part 22, a lens housing part 23, and a light emitting window part 24 are sequentially formed at one end thereof toward the center of the holder 20, The other end is provided with the holder 2
A light-receiving element housing 25, a shield case housing 28, and a lower light-shielding wall 29 having a light-receiving window are sequentially formed toward the center of 0. Vertical insertion holes 22a and 25a continuous with the storage portions 22 and 25 are formed below the light emitting element storage portion 22 and the light receiving element storage portion 25, respectively. The bottom surface 20a of the holder 20 is horizontal, and the upper surfaces of the storage portions 22, 25 are open so that the light emitting element 30 and the light receiving element 35 can be inserted from above.

As shown in FIGS. 8 and 15, a light emitting element, for example, an LED 30, is a so-called side light emitting type light emitting element in which the optical axis is formed in a direction perpendicular to the axis. Are provided. Lens 3
Support portions 33 and 34 are provided on the upper and lower portions of 2 respectively. The light receiving element, for example, the PD 35 has an optical axis perpendicular to the axis, and a vertical lead terminal 36 is provided below the optical axis. The shield case 37 is unpainted, and a light receiving window 38 is formed on the front surface thereof. On the upper surfaces of the light emitting element 30, the lens support portion 33, and the shield case 37, contact portions 30a, 33a, and 37a that are pressed against the optical bench 40 are formed.

The optical table 40 is shown in FIGS. 7, 14, 17, and 1.
8 is configured. Bottom surface 40 of optical bench 40
In a, a light-emitting unit housing 41, a light-receiving unit housing 42, and a light-shielding column 43, whose lower surfaces are open, are provided. The two storage portions 41 and 42 are formed corresponding to the optical bench holder 20, and the inner surface of the light-emitting portion storage portion 41 has a contact portion 41 a for pressing the light-emitting element 30 and a lens 32.
Is provided with a groove portion 45 that is in pressure contact with. Light receiving section storage section 4
2 has an upper light-shielding wall 4 in contact with a lower light-shielding wall 29.
4 and a contact portion 42a that is in pressure contact with the shield case 37. A labyrinth 47 is annularly arranged on the bottom surface 40a of the optical bench so as to sandwich the light emitting unit housing 41 and the light receiving unit housing 42 therebetween. An insect screen 46 shown in FIG. 6 is provided on the outer periphery of the labyrinth 47,
The insect net 46 is supported by an annular wall 49. The annular wall 49 is provided on the side of the optical bench 40, and its tip 49 a is located below the labyrinth 47. On the side of the optical table 40, 3
A book hook 48 is provided.

The optical bench cover 50 is shown in FIGS.
9, and as shown in FIG. Optical stand cover 5
The holder 51 of the thermal element 70, the lead wire guide groove 55, and the cylindrical portion 52 are provided on the upper surface of the element 0. This holder 5
Reference numeral 1 denotes a cylindrical shape, in which three positioning grooves 51a are provided at equal intervals in the circumferential direction. The cylindrical portion 52 is provided on the outer peripheral edge of the optical bench cover 50, and has the same height as the holder 51. A plurality of protrusions 54 are formed on the lower surface of the cover 50, and the protrusions 54 are fitting holes formed on the respective upper surfaces of the labyrinth 47, the light emitting unit housing 41, and the light receiving unit housing 42. 47b, 41b, 42
b. The thermal element 70 is held by a support 71, and one end of the thermal element 70 is connected to a lead wire 72. An insertion hole 71a through which the lead wire 72 or the thermal element 70 passes is provided at the center of the support body 71, and a projection 71b fitted into the positioning groove 51a of the holder 51 is formed on the outer periphery thereof. .

The protective cover 60 is configured as shown in FIGS. 1, 3 and 4. The protective cover 60 is connected to a top plate 63 via a flange 61 and a connecting column 62. An insertion hole 63a for the thermal element 70 is provided at the center of the top plate 63, and a crimp portion 63b is provided on the lower surface thereof. The collar 61 is provided with a check rod insertion hole 64 and an indicator light hole 66, and a smoke inlet 65 is provided between the collar 61 and the top plate 63. The main body 1 is provided on the outer peripheral edge of the flange 61.
A hook is provided for engaging with the engaging portion 4 of the first embodiment. The top plate 63 is provided with a thermal element protection ring 69 via a support post 68. On the lower surface of the protection ring 69, a projection 69a is provided so that a finger or the like does not enter from between the columns 68 adjacent to each other.

Next, the operation of this embodiment will be described. After the lead terminal 31 is inserted into the insertion hole 22a of the optical bench holder 20 and the side light emitting type light emitting element 30 is stored in the light emitting element storage part 22, the support part 34 of the lens 32 is replaced with the lens storage part 2.
Store in 3. At this time, the light emitting element 30 and the lead terminal 31
Is held vertically. Lead terminal 3 in insertion hole 25a
6, the light receiving element 35 is housed in the light receiving element housing part 25. At this time, the light receiving element 35 and the lead terminal 36 are held vertically. Further, a shield case 37 is fitted into the shield case storage section 28, and is covered with the light receiving element 35 to shield.

The optical table holder 20 is placed on the bottom surface 40 of the optical table 40.
The light emitting element 30 is housed in the light emitting part housing part 41 and the light receiving element 35 is housed in the light receiving part housing part 42.

The hook 48 of the optical table 40 is inserted into the insertion hole 17 of the printed circuit board 10, and the hook 48 is
7a. Then, while the optical table 40 is centered by the three hooks 48, its bottom surface 40a
Are directly in contact with the printed circuit board 10. In this state, the optical bench 40 is accurately positioned on the optical bench mounting portion 13, and the optical bench holder 20 is sandwiched between the optical bench 40 and the printed circuit board 10.

At this time, the light emitting element 30 of the optical bench holder 20
Abutment portion 30a, abutment portion 33 of support portion 33 of lens 32
a, the abutting portion 37a of the shield case 37 is pressed by the abutting portion 41a, the groove 45, and the abutting portion 42a on the inner surface of the optical bench, so that they are accurately arranged at predetermined positions,
Even if there is vibration, the position does not go out of order. Therefore, the optical axis L of the light emitting element 30 and the light receiving element 35 is
Can always be kept parallel to the bottom surface 40a. The optical axis L is located at substantially the same height as the tip 49a of the annular wall 49.

An insect net 46 is provided on the outer periphery of the labyrinth 47, and the insect net 46 is supported by an annular wall 49. After that, the projection 54 of the optical bench cover 50 is fitted into the fitting hole 47b of the labyrinth 47, the fitting hole 41b of the light emitting unit housing 41, and the light receiving unit housing 42b. Thereby, the inside of the optical bench 40 becomes dark, and a so-called dark box is formed. At this time, the shield case 37 is not exposed to the smoke monitoring space S because the shield case 37 is surrounded by the light receiving section housing portion 42 of the optical bench 40, the upper light shielding wall 44, and the lower light shielding wall 29 of the optical bench holder 20. Therefore, even if the shield case 37 is unpainted, the scattered light in the dark box is not reflected by the shield case.

The lead wire 72 is inserted into the through hole 71a of the support 71.
To make the thermal element 70 vertical and to bend the lead wire 72 into an L-shape. Then, the support 71 is moved toward the holder 51 of the optical bench cover 50, the protrusion 71b is fitted into the positioning groove 51a, and the lead wire 72 is fitted and fixed in the lead wire guide groove 55. At this time, the support 7
1 is accurately held at the center of the optical bench cover 50 by the projection 71b and the positioning groove 51a. Note that the lead wire 72 is connected to the printed circuit board 10. The printed board 10 is placed on the support pillar 3 of the main body 1, and the tip of the protruding pillar 9 is inserted into the hole of the printed board 10, and the terminal screw 6 is inserted into the insertion holes 2 and 18. Thereafter, the fixing portion 5a of the blade fitting 5 is brought into contact with the lower surface 1b of the main body 1, and the terminal screw 6 is rotated to be mounted in the screw hole 7 and fixed. The protective cover 60 is moved toward the optical base cover 50, and the support 71 is inserted and fitted into the insertion hole 63 a of the top plate 63, and the support 71 and the optical base cover 50 are joined by the crimping portion 63 b of the top plate 63. While holding down, the hook 67 is engaged with the locking portion 4 of the main body 1 and fixed. In this state, the support 71 is securely fixed, and the heat-sensitive element 70 is set upright from the center of the top plate 63 at a predetermined position. The lead wire 72 is connected to the protective cover 6.
It is hidden inside the 0 connecting pillar 62 and is not exposed to the outside.

The embodiment of the present invention is not limited to the above. For example, instead of directly fixing the lower surface 40a of the optical bench 40 to the printed circuit board 10, an annular ring is provided on the lower surface and the ring is attached to the printed circuit board 10. You may make it contact. Also, instead of an annular ring, a plurality, for example, 3
The projections may be arranged at intervals in the circumferential direction. The check terminals 12 may be formed on the printed circuit board 10 in a printed pattern. The check rod insertion hole 64 of the protective cover 60 may be omitted. Further, a blade receiving member or the like may be used as the conductive connecting member.

[0021]

As described above, according to the present invention, the thermal element is always disposed at the design position, and the position is maintained. Therefore, the sensitivity of the thermal element can be made constant among the plurality of sensors. Also, since the lead wire of the thermal element is guided by the lead wire guide groove and is in a predetermined state,
Connection work to a printed circuit board becomes easy.

[Brief description of the drawings]

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

FIG. 2 is a bottom view showing the embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view taken along line AA of FIG. 1;

FIG. 4 is a perspective view showing a protective cover of the present invention.

FIG. 5 is a perspective view showing an optical bench cover and the like of the present invention.

FIG. 6 is a perspective view showing the insect net of the present invention.

FIG. 7 is a perspective view showing an optical bench of the present invention.

FIG. 8 is a perspective view showing an optical bench holder and the like of the present invention.

FIG. 9 is a perspective view showing a terminal screw of the present invention.

FIG. 10 is a perspective view showing a printed board of the present invention.

FIG. 11 is a perspective view showing a main body of the present invention.

FIG. 12 is a perspective view showing a blade fitting of the present invention.

13 is a cross-sectional view showing the optical bench cover taken along the line AA in FIG. 1 of the present invention.

FIG. 14 is a cross-sectional view showing the optical bench taken along the line AA of FIG. 1 of the present invention.

FIG. 15 is a cross-sectional view showing a shield case, a lens, a light emitting element, and a light receiving element in a cross section taken along line AA of FIG. 1 of the present invention.

FIG. 16 is a cross-sectional view showing the optical bench holder taken along the line AA of FIG. 1 of the present invention;

FIG. 17 is a plan view of the optical bench of the present invention.

FIG. 18 is a bottom view of the optical bench of the present invention.

FIG. 19 is an enlarged view of FIG. 5;

FIG. 20 is a sectional view taken along line BB of FIG. 19;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 5 Blade fitting (conductive fitting) 10 Printed circuit board 20 Optical stand holder 30 Light emitting element 35 Light receiving element 37 Shield case 40 Optical stand 46 Insect repellent net 47 Labyrinth 50 Optical stand cover 51 Holder 60 Protective cover 63 Top plate 63a insertion hole 67 Hook 70 Thermal element 71 Support 72 Lead wire

Claims (4)

(57) [Claims] An optical cover provided at a central portion of an upper surface of the optical bench cover;
With a positioning holder;
A support pinched between the optical bench cover and the protective cover
Holding member; provided upright on the support member, on a printed circuit board
A thermal element having a lead wire connected thereto;
Insertion hole, which is provided on the top plate of
And a thermo-electric fire detector. 2. A holder having a positioning groove provided at a central portion of an upper surface of the optical bench cover; a lead wire guide wall provided on the optical bench cover and extending from the holder to an edge of the cover;
A support that is provided with a plurality of protrusions fitted into the positioning groove, is fitted to the holder, and is sandwiched between the optical bench cover and the protective cover; A thermoelectric fire detector, comprising: a heat-sensitive element connected to a printed board through the guide wall; and an insertion hole provided in a top plate of the protective cover. 3. The thermoelectric fire detector according to claim 1, wherein a projection is formed on a lower surface of the optical bench cover to be fitted to the optical bench. 4. The thermoelectric fire detector according to claim 1, wherein a cylindrical portion is formed on an outer peripheral edge of the optical bench cover.