JP3097009B2 - 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, when an external electrode is attached to a printed circuit board, it is difficult to solder it to an accurate position because the external electrode moves. Also, the shield case is soldered to the printed circuit board, and furthermore, the shield case is indirectly connected to the external electrodes via the printed circuit board. Occurs.

[0004] In view of the above circumstances, it is an object of the present invention to enable an external electrode to be easily and accurately arranged. Another object is to ensure the electrical connection between the shield case and the external electrodes.

[0005]

According to the present invention, an engagement hole is provided in each of upper side walls of a plurality of insertion pieces of an external electrode, and a plurality of through holes of a printed circuit board are penetrated at an upper end thereof. A bowl-shaped shield case having an engagement piece engaged with the mating hole is provided, and the plurality of engagement pieces are passed through the through-hole from the lower surface side of the substrate. An ionization type smoke detector characterized by being engaged with a mating hole,
Thus, the above object is achieved.

[0006]

After inserting and temporarily fixing a plurality of insertion pieces of the external electrode on the upper surface of the printed circuit board, the insertion pieces are soldered. A shield case is provided on the back side of the printed circuit board, and an engagement piece of the shield case is projected from the printed circuit board and locked in an engagement hole of an external electrode.

[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. An insertion hole 38 for inserting an FET is formed in the shield portion 11. On the lower surface 10b of the printed circuit board 10, an electric circuit component 10e of a surface mount type as shown in FIG. 3 is provided. 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. Insertion holes 1 are provided on the outer peripheral surface and side
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 is 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 airflow 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 section 43 of the external electrode 40, and the reduced-diameter section 105 is formed by the small-diameter cylinder 103. 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 a plurality of insertion pieces are provided at the lower end of the external electrode, when the external electrode is attached to the printed circuit board, it can be temporarily fixed. Therefore, the alignment is more accurate than in the conventional example, and the fixing operation and the subsequent soldering of the external electrodes to the printed circuit board are also facilitated. (2) Since the engagement piece of the shield case is locked in the engagement hole of the external electrode, the two are directly connected and the attachment work is easier and easier than in the conventional example.

[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 an 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 Disaster Prevention Co., Ltd. (72) Inventor Kazuyuki Koganemaru 4-73 Kudanminami, Chiyoda-ku, Tokyo Nomi Disaster Prevention Co., Ltd. (56) References JP-A-55-143696 (JP, A) (JP, U) JitsuHiraku flat 1-116893 (JP, U) JitsuHiraku Akira 64-57592 (JP, U) JitsuHiraku Akira 56-73096 (JP, U) (58 ) investigated the field (Int.Cl. ⁷ , DB name) G08B 17/02-1 7/12

Claims (4)

(57) [Claims] 1. A cylindrical external electrode having a lid portion and having a smoke inlet on a side wall, a lower end of which is provided with a plurality of downwardly projecting insertion pieces, and a printed board is provided with a plurality of insertion pieces corresponding to the insertion pieces. A plurality of insertion holes are provided so as to lock the insertion piece at its edge, and the insertion piece is inserted through the insertion hole from the upper surface side of the board and locked, and the insertion piece is inserted into the lower surface side of the board. An ionization type smoke detector characterized in that pieces are soldered to printed wiring. 2. An ionization type smoke detector wherein a plurality of insertion pieces are provided at a lower end of an external electrode, and a plurality of engagement holes are provided on a side wall of the external electrode. 3. The ionization method according to claim 1, wherein said shield case is formed in a bowl shape, and said shield case is provided with an engagement piece for engaging with an engagement hole of an external electrode and an insertion hole for press-fitting a projection of a main body. Type smoke detector. 4. An engaging hole is provided in each of the upper side walls of the plurality of insertion pieces of the external electrode, and the upper end thereof penetrates the plurality of through holes of the printed circuit board and engages with the engaging holes. A bowl-shaped shield case provided with a plurality of engagement pieces, the plurality of engagement pieces of the shield case are passed through the through holes from the lower surface side of the substrate, and the engagement pieces are engaged with the engagement holes. An ionization type smoke detector characterized by the following.