JP3128638B2 - Ionized smoke detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ionization type smoke detector.

[0002]

2. Description of the Related Art In a conventional ionization type smoke detector, a blade fitting is provided on a lower surface of a main body, and a printed circuit board is fixed on an upper surface thereof. A shield case is provided on the lower surface of the printed circuit board, and an electrode mount is fixed on the upper surface. An internal electrode provided with a radiation source is provided inside the electrode mount, and an intermediate electrode is fixed on the upper surface thereof. This intermediate electrode is covered by an external electrode,
Further, the external electrode is surrounded by a windproof cover. An insect screen is provided between the windproof cover and the external electrode. The printed circuit board is covered with a protective cover. (See JP-A-1-93895)

[0003]

In the conventional ionization type smoke detector, the head of the internal electrode is disk-shaped, so that it is difficult to handle. Therefore, the fixing work of the internal electrodes is troublesome and requires a long time. Further, in order to obtain the performance of the sensor as designed, the electrode mount must be fixed at a predetermined position on the printed circuit board. However, in the conventional example, misalignment is likely to occur between the two, and accurate alignment is difficult. .

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to facilitate the work of fixing an internal electrode and to easily fix an electrode mount and a printed circuit board at a designed position.

[0005]

According to the present invention, a plurality of projections of an electrode mounting base are press-fitted into insertion holes of a printed circuit board and temporarily fixed, and legs of internal electrodes are inserted through the insertion holes of the electrode mounting base. The internal electrode receiving part is formed by forming a head of the internal electrode in a polygonal shape, and further storing the internal electrode.
Is provided on the electrode mounting base, and a cylindrical wall is provided around the internal electrode housing.
And an intermediate voltage at an edge of the cylindrical wall at circumferential intervals.
It is an object of the present invention to achieve the above object by using an ionization type smoke detector provided with a pole mounting hole and an FET storage section .

[0006]

After the protrusion of the electrode mounting base is pressed into the insertion hole of the printed circuit board and temporarily fixed, the legs of the internal electrodes are inserted into the insertion hole of the electrode mounting base and the printed circuit board to protrude toward the lower surface of the printed circuit board. Then, a nut is attached to the threaded portion of the leg and tightened.

[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 1 a of the main body 1, a support column 3 having an insertion hole 2, a projection 8 for locking a shield case 60, and a printed circuit board 10
The main body 1 is provided with a locking portion 4 on the outer periphery of the main body 1. 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. 18 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.
It is composed of The fixing portion 5a is provided with a screw hole 7 to be screwed with the terminal screw 6 shown in FIG.
The blade portion 5b is engaged with a blade receiving member, which is a base conductive connecting member (not shown).

The printed board 10 is configured as shown in FIG. At the center of the printed circuit board 10, an insertion hole 37 through which the leg 31 of the radiation source mount 30 passes is provided.
On the upper surface 10a, a shield portion 11 and a check terminal 1 are provided.
2, a source mounting base mounting portion 13, and an indicator lamp 14 are provided. The shield portion 11, insertion holes 38 for inserting the F ET are formed. On the lower surface 10b of the printed circuit board 10 , a surface mount type electric circuit component 10e is provided as shown in FIG. The printed board 10 has an insertion hole 17 through which the hook 108 of the windproof ring 100 is inserted.
Are provided, and a plurality of locking portions 17a of the hook 108 are provided on the periphery of the insertion hole 17 on the lower surface 10b side.
Further, the substrate 10 has an insertion hole 18 of the projection 21 formed on the electrode mounting base 20 and an insertion piece 41 provided on the external electrode 40.
And the insertion hole 15 of the engagement piece 61 of the shield case 60 are formed. The check terminal 12
May use a wiring pattern on the printed circuit board 10.

The electrode mount 20 is configured as shown in FIG. A plurality of cylindrical walls 23 are provided around the internal electrode housing portion 22 of the mounting base 20, and the housing portion 22 has
The insertion hole 24 of the leg 31 of the radiation source mount 30 is formed. An intermediate electrode mounting hole 25 and an FET accommodating portion 26 are provided at an edge of the central cylindrical wall 23 at intervals in the circumferential direction. The lower surface of the FET housing portion 26 is open, and a connection terminal 28 is provided on the upper surface. The connection terminal 28 has a bag-like shape and
Constitutes a first socket into which the gate electrode 81 can be inserted. In the outer peripheral surface and the side wall of the electrode mount 20, the insertion hole 1 is formed.
A plurality of projections 21 and 21a to be fitted into the projection 8 are provided at intervals in the circumferential direction.

The source mounting table 30 is shown in FIGS.
0, FIG. 21, FIG. 25, and FIG. The source mounting base 30 is an internal electrode whose head 30t is formed in a polygonal shape, and a leg 31 having a screw portion 31a on the lower surface thereof.
Is provided, also, a rectangular-shaped radiation source in the center portion of the upper surface of the beam source mount 30, for example, americium 241 radiation source 32
The radiation source 32 is covered with a radiation source protection cover 33. The source protection cover 33 includes a guide piece 34 and a bent piece 35.

The intermediate electrode 90 is formed in a bowl shape as shown in FIG. At the center of the bottom surface of the intermediate electrode 90, a radiation transmission hole 91 is provided.
8, an insertion hole 93 of the positioning projection 29 of the electrode mount 20, and a screw hole 9 of a screw 94 shown in FIG. 8.
5 are formed.

The external electrode 40 is configured as shown in FIG. The external electrode 40 has a continuous large-diameter cylindrical portion 42.
And a small-diameter cylindrical portion 43. In the large-diameter cylindrical portion 42,
A plurality of downward insertion pieces 41 are provided, and an engagement hole 44 is formed in a side wall thereof. A lid portion 45 is provided on the upper surface of the small-diameter cylindrical portion 43, and a smoke inlet 46 is provided on a side wall thereof. 39 is an external ion chamber.

The windbreak ring 100 is configured as shown in FIG. The windbreak ring 100 adjusts the inflow speed of the airflow flowing into the external ion chamber, and includes a large-diameter cylinder 101.
And a cylindrical body including an annular step portion 102 and a small-diameter cylinder 103. The large-diameter cylinder 101 has a slightly larger diameter than the large-diameter cylindrical portion 42 of the external electrode 40 and is configured to surround a side portion of the large-diameter cylindrical portion 42.
08 is formed. The small-diameter tube 103 is
The diameter of the small diameter cylindrical portion 43 is larger than that of the small diameter cylindrical portion 43
An airflow deceleration mechanism is provided in an upper portion surrounding the side portion of the airbag. The air flow deceleration mechanism is configured such that the upper portion of the small-diameter cylinder 103 has a smaller diameter than the small-diameter cylinder main body and a slightly larger diameter than the small-diameter cylindrical portion 43 of the external electrode 40. It is supported by a plurality of columns 106 projecting inward from the upper end of the main body. The annular step 102 is provided with the small-diameter cylinder 10.
3 and the large-diameter cylinder 101 such that the inner wall substantially contacts the step of the cylindrical body of the external electrode 40 or the surface of the inclined surface, and the outer wall substantially contacts the inner surface of the protective cover 120. It is configured.

The protective cover 120 is configured as shown in FIGS. The flange 121 of the protective cover 120 is connected to a top plate 123 via a support pillar 122. The flange 121 has a check rod insertion hole 124 and an indicator light hole 125.
Are formed. A plurality of smoke inlets 126 are provided between the flange 121 and the top plate 123. A hook 127 that engages with the locking portion 4 of the main body 1 is provided on the outer peripheral edge of the protective cover 120. Further, a plurality of smoke inlets 128 are provided in the top plate 123.
8 may not be provided. Also, the check rod insertion hole 124
May be omitted.

A printed circuit board piece 83 as shown in FIGS. 15 and 24 is brought into contact with the lower surface of the printed circuit board 10, and the drain electrode 82 and the drain electrode 82 of the FET 80 are formed on the upper surface of the printed circuit board 83 as shown in FIG. A second socket 84 into which the source electrode 86 is inserted is provided. In the second socket 84, a holding spring 85 for separately holding the drain electrode 82 and the source electrode 86 is provided.

Next, a method of assembling the present embodiment will be described. The projection 21 of the electrode mount 20 is fitted into the insertion hole 18 of the printed circuit board 10 and temporarily fixed. Then, since the mounting table 20 is centered by the projections 21, the mounting table 20 is accurately positioned on the electrode mounting table mounting section 13 of the printed circuit board 10. The radiation source 32 is placed on the radiation source mount 30, the radiation source cover 33 covers the radiation source 32, and the bent piece 35 is folded inward to fix the radiation source 32. In this state, the leg 31 of the source mount 30 is inserted into the insertion hole 24 of the electrode mount 20, and the screw portion 31 a projecting to the lower surface side through the insertion hole 37 of the printed circuit board 10 is connected to the nut 36 shown in FIG. Tighten with
Since the internal electrodes 30 are polygonal, the fixing operation is easy.
The intermediate electrode 90 is placed on the electrode mount 20, and the connection terminal 28 is
Is easily sandwiched between the spring holes 92 for easy electrical connection. The projection 29 is inserted into the insertion hole 93 and positioned. And
Screw 94 is screwed into mounting hole 25 to fix intermediate electrode 90.

After the external electrode 40 is placed on the printed circuit board 10 while covering the intermediate electrode 90, the insertion piece 41 is inserted into the insertion hole 19 of the printed circuit board 10, temporarily fixed, and then soldered. The insect net 130 of FIG.
Is disposed on the printed circuit board 10 while covering the external electrode 40 with the windproof ring 100, and the hook 108
Is locked to the locking portion 17a of the printed circuit board 10 and fixed. As described above, the windproof ring 100 is easily fixed, but has no backlash and can be easily attached and detached. Next, FE
After inserting the drain electrode 82 and the source electrode 86 of T80 into the second socket 84, the FET 80 is
The gate electrode 81 of the FET 80 is inserted into the first socket of the connection terminal 28, and the printed circuit board piece 83 is soldered to the lower surface of the printed circuit board 10. Thus, the FET 80 is connected to the socket 2
Since the fixing is carried out by 8, 84, the mounting work and the replacing work of the FET 80 become easy. Further, since the FET 80 is covered by the electrode mounting base 20, the printed circuit board 10, and the printed circuit board piece 83, there is no danger that electric components and the like will be contaminated by dust and the like, and the insulation will be reduced. It is.

After the projection 8 of the main body 1 is inserted into the insertion hole 62 of the shield case 60 shown in FIG. 16 and the shield case 60 is placed on the upper surface of the main body 1, the engaging piece 61 of the shield case 60 is printed. The printed circuit board 10 is projected to the upper surface side of the printed circuit board 10 while passing through the insertion hole 15 of the board 10, locked in the engaging hole 44 of the external electrode 40, and the printed circuit board 10 is placed on the support column 3. At this time, the printed circuit board 10 is accurately positioned by the tip of the protruding column 9 of the main body 1 entering a predetermined hole. After the fixing portion 5a of the blade fitting 5 is brought into contact with the lower surface of the main body 1, the insertion hole 2 of the support column 3 is formed.
Then, the terminal screw 6 is inserted and rotated, and screwed into the screw hole 7. Then, the printed circuit board 10 and the blade fitting 5 are simultaneously tightened and fixed to the main body 1. The protective cover 120 is put on the main body 1, the hook 127 is engaged with the locking portion 4, and the indicator lamp 14 is inserted into the indicator lamp hole 125.

[0019]

As described above, the present invention has the following remarkable effects. (1) Since the head of the internal electrode is formed in a polygonal shape, the handling of the internal electrode becomes easy, and the fixing of the internal electrode, that is, the fixing of the electrode mounting base becomes easy. (2) Since the plurality of projections of the electrode mounting base are press-fitted into the insertion holes of the printed circuit board and temporarily fixed, the two are integrated while the positional relationship with the electrode mounting base is regulated. Therefore, screwing by the internal electrodes becomes easy, and positioning of the electrode mounting base with respect to the printed circuit board becomes accurate.

[Brief description of the drawings]

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

FIG. 2 is a bottom view of FIG.

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

FIG. 4 is a component view of the embodiment of the present invention, and is a perspective view showing a protective cover.

FIG. 5 is a perspective view showing a windbreak ring 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 external electrode of the present invention.

FIG. 8 is a perspective view showing a screw of the present invention.

FIG. 9 is a perspective view showing an intermediate electrode of the present invention.

FIG. 10 is a perspective view showing a radiation source mount 30 of the present invention.

FIG. 11 is a perspective view showing an electrode mount of the present invention.

FIG. 12 is a perspective view showing a terminal screw of the present invention.

FIG. 13 is a perspective view showing a printed board of the present invention.

FIG. 14 is a perspective view showing a nut of the present invention.

FIG. 15 is a perspective view showing an FET and the like of the present invention.

FIG. 16 is a perspective view showing a shield case of the present invention.

FIG. 17 is a perspective view showing a main body of the present invention.

FIG. 18 is a perspective view of the blade fitting of the present invention.

FIG. 19 is an enlarged perspective view showing the radiation source cover of the present invention.

FIG. 20 is an enlarged perspective view showing the radiation source of the present invention.

FIG. 21 is an enlarged perspective view showing the radiation source mount of the present invention.

FIG. 22 is an enlarged perspective view showing the FET of the present invention.

FIG. 23 is an enlarged perspective view showing a second socket of the present invention.

FIG. 24 is an enlarged perspective view showing a printed circuit board piece of the present invention.

FIG. 25 is an enlarged plan view showing a radiation source mount according to the embodiment of the present invention.

26 is a sectional view taken along line BB of FIG. 25.

FIG. 27 is an enlarged view of a main part of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 5 Blade fitting 6 Terminal screw 10 Printed circuit board 20 Electrode mounting base 21 Projection part 22 Internal electrode storage part 28 Connection terminal (socket) 30 Source mounting base 32 Radiation source 40 External electrode 60 Shield case 80 FET 84 Socket 90 Intermediate electrode 91 Transmission hole 100 Windproof ring 108 Hook 120 Protective cover 124 Check rod insertion hole 127 Hook

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ikuhisa Hatanaka 4-73-3 Kudanminami, Chiyoda-ku, Tokyo Nomi Disaster Prevention Co., Ltd. (72) Inventor Kentaro Higashi 4-73 Kudanminami, Chiyoda-ku, Tokyo Nomi Disaster Prevention Co., Ltd. (72) Nobuo Hatori, Inventor No. 4-73, Kudanminami, Chiyoda-ku, Tokyo Nomi Disaster Prevention Co., Ltd. Inside the Disaster Prevention Co., Ltd. (72) Inventor Kazuyuki Koganemaru 4-73-3 Kudanminami, Chiyoda-ku, Tokyo Nomi Disaster Prevention Co., Ltd. (JP, U) JP-A 64-57593 (JP, U) JP-A 2-92594 (JP, U) JP-A 62-57893 (JP, U) (58) Fields surveyed (Int. Cl. ⁷⁾ , DB name) G08B 17/02-17 / 12

Claims (3)

(57) [Claims] 1. A plurality of projections of an electrode mounting base are press-fitted into insertion holes of a printed circuit board and temporarily fixed, and legs of internal electrodes are inserted into the insertion holes of the electrode mounting base and screwed into the mounting holes. The head of the electrode is formed in a polygonal shape , and the internal electrode is
An internal electrode storage part to be stored is provided on the electrode mounting base,
A cylindrical wall is provided around the electrode storage portion, and a peripheral wall is formed around an edge of the cylindrical wall.
The intermediate electrode mounting hole and the FET storage section are
Ionization smoke detector, characterized in that digit. 2. An interior in which an intermediate electrode having a transmission hole in the center is mounted on the upper surface, and a radiation source is provided on the upper surface and an internal electrode having a polygonal head is housed in the electrode mounting base. An electrode housing portion is provided, an insertion hole through which the leg portion of the internal electrode is inserted is provided at the center of the housing portion, and a plurality of protrusions are provided on the lower surface thereof. A plurality of insertion holes, and an insertion hole through which the leg portion is inserted. The electrode mounting base has a projection on a lower surface thereof pressed into an insertion hole provided on the substrate and an upper portion of the internal electrode. Is accommodated in the storage portion, the lower part of which is fixed to the substrate on the lower surface side of the substrate through the insertion hole of the mounting table and the insertion hole provided in the substrate ,
Furthermore, a cylindrical wall is provided around the internal electrode housing.
And an intermediate electrode is provided at an edge of the cylindrical wall at a circumferential interval.
An ionization type smoke detector characterized by having a perforated hole and an FET storage section . 3. The printed circuit board according to claim 1, wherein the plurality of protrusions of the electrode mounting base are provided on a printed circuit board.
Into the through hole of the electrode mounting base and temporarily fix it.
Insert and screw the legs of the internal electrode
The head of the electrode is formed in a polygonal shape,
On the upper surface of the shield, check terminal and source mounting base
And an ionization type smoke detector.