JP3014600B2 - Assembly structure of 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 assembling structure of a smoke detector having a structure in which a smoke detection unit cover is detachably mounted over a smoke detection unit of a smoke detection unit main body.

[0002]

2. Description of the Related Art Conventionally, in a scattered light type smoke detector,
A smoke detector cover is formed to cover the smoke detector provided with the light emitting element and the light receiving element to form a smoke detector room. The smoke detection section cover has a labyrinth structure and an insect repellent that function as a trap that absorbs noise from the outside, blocks the incidence of external light, and at the same time absorbs noise light from the light emitting element provided in the smoke detection section. A net is provided. An outer cover having a smoke inlet is attached to the outside of the smoke detection unit cover.

In such a scattered light type smoke detector, it is necessary to clean dust adhering to a smoke detector provided with a light emitting element and a light receiving element at the time of periodic inspection and the like.
For this reason, the smoke detector cover provided to cover the smoke detector of the sensor body has a detachable structure, and the cover is removed so that the smoke detector can be cleaned.

[0004]

However, in the structure of a smoke detector provided with a smoke detector cover detachable from the smoke detector of the sensor body, the smoke detector cover is detachable. In the mounted state, it is easy for a small gap to be formed between the detector and the sensor body. Through this gap, external light enters the smoke detection section and becomes noise light when there is no inflow of smoke. There is a problem that the S / N of the light receiving element to be detected is reduced, and the detection sensitivity is reduced.

Further, the sensor body and the smoke detection unit cover are formed of plastic, and there is a problem that the attachment and detachment are repeated, and rattling is apt to occur due to aging, which causes light leakage. SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem. Even if a smoke detection unit cover is detachably provided to a smoke detection unit main body, the smoke detection does not cause a gap or rattling in an assembled state. An object of the present invention is to provide an assembling structure of a container.

[0006]

In order to achieve this object, in the assembly structure of a smoke detector according to the present invention, a cover fitting having a tapered step formed on a mounting surface of a smoke detector is provided. A smoke detection section main body having a recess formed therein; and a smoke detection section cover having a tapered peripheral portion formed opposite to a tapered step of a cover fitting recess formed in the smoke detection section main body. In a state where the smoke detection section cover is fitted to the joint section, a tapered peripheral edge portion with respect to the tapered step is pressed and fixed to be in close contact.

In the smoke detector assembling structure of the present invention, the surface on the opposite side of the smoke detecting portion main body having the cover fitting concave portion is formed in an inverted convex shape so that the thickness of the smoke detecting portion main body is uniform. It is characterized by having Further, a stepped portion having the opposite convex shape is used as a sponge storage section, and a rubber sponge for waterproofing is arranged in the sponge storage section.

[0008]

According to the assembling structure of the smoke detector of the present invention, the tapered peripheral portion of the smoke detector cover is pressed by being turned into the taper step of the cover fitting concave portion formed in the smoke detector main body. It is fixed detachably. For this reason, the taper step acts like a wedge as a conical hole and the tapered peripheral edge as a conical part, and the taper surfaces adhere to each other with vertical pressing force, and the smoke detection unit cover is assembled without generating gaps or play. Fixed.

Further, the thickness of the surface formed with the cover fitting concave portion of the smoke detecting portion main body is made uniform, and the inverted convex shape formed on the opposite surface is used for the sponge storage portion of the rubber sponge for waterproofing. Thus, the thickness of the sensor can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded view showing an embodiment of a photoelectric smoke sensor according to the present invention, which constitutes a sensor main body. In FIG. 1, a fitting 10 is connected to a terminal board 11 on a sensor main body side with respect to a sensor base (not shown) mounted on a ceiling.
Are used to electrically and mechanically connect
It is configured to be electrically connected to the conductive pattern of the substrate 13 by the screw 24.

To the terminal board 11, a shield case 12, a printed circuit board 13, a rubber sponge 14, a smoke detection section main body 15, a smoke detection section cover 16, and an outer cover 17 are attached in order from the sensor base side. The base and each of the members 11 to 17 from the terminal board 11 to the outer cover 17 are formed in a substantially cylindrical or circular shape so that they can be fitted to each other. Here, by attaching the smoke detection section main body 11 to the terminal board 11, a circuit storage section including the shield case 12 is formed therebetween. A printed circuit board 13 on which electronic components of the sensor circuit are mounted is incorporated in the circuit housing portion. In addition, by incorporating the rubber sponge 14, a waterproof structure to be described later will be realized.

Subsequently, the smoke detection section main body 15 and the smoke detection section cover 16
The space enclosed by the smoke detector constitutes a smoke detector room, and the smoke detector main body 1
5 has a smoke detection LED on the lower surface (the smoke detection unit cover 16 side).
18, a test LED 19 and a light receiving element (PD) 20 are attached. The smoke detection unit body 15 also has a smoke detection LE
The light-emitting unit cover 21 is attached after the D18 is attached, the light-receiving unit cover 22 is attached after the test LED 19 and the PD 20 are attached in close proximity, and the shield cap 2 is placed on the light-receiving unit cover 22.
3 is attached.

The lead wires of the LEDs 18, 19 and PD 20 and the shield cap 23 penetrate through the smoke detector main body 15, the rubber sponge 14, and the printed circuit board 13 and are soldered on the upper surface side of the printed circuit board 13. Also, terminal board 1
1, the shield case 12, the printed circuit board 13, and the rubber sponge 14 are attached therebetween by attaching the smoke detection unit main body 15 with the screw 24, and the rubber sponge 14 is used between the terminal board 11 and the smoke detection unit main body 15. The periphery is sealed. The smoke detection unit cover 16 is detachably attached to the smoke detection unit main body 15 by rotating and fitting, and the outer cover 17 is attached to the terminal board 11 so as to cover the entire sensor.

First, the waterproof structure will be described in detail with reference to FIGS. FIG. 2 shows the sponge 1 with respect to the smoke detection section main body 15.
4 and the assembly of the printed circuit board 13 are shown. In FIG. 2, the smoke detection unit main body 15 is a disk-shaped member, and has a peripheral wall 15a formed around the upper side of the circuit storage unit. A sponge storage section 15c is formed inside the peripheral wall 15a. The sponge accommodating portion 15c is formed by using an inverted convex shape accompanying a formation of a cover fitting concave portion of the smoke detecting portion cover 16 with respect to a surface opposite to the smoke detecting portion main body 15 described later.

The inside of the sponge storage section 15c is partitioned by a step 15b formed on the center side of the smoke detection section main body 15.
The step of the sponge accommodating portion 15c with respect to the step 15b is made smaller than the thickness before the rubber sponge 14 is assembled. For this reason, the sponge storage unit 15
When the rubber sponge 14 is incorporated into the portion c, the surface of the rubber sponge 14 slightly protrudes from the central step 15b.

Further, protrusions 15d for positioning the rubber sponge 14 extend radially at three positions from the center side step portion 15b to the sponge storage portion 15c. Although not shown in the drawings, the protrusion 15d has L
Holes for penetrating the lead wires of the EDs 18, 19 and PD 20 are formed. Further, a positioning projection 15e used for positioning the rubber sponge 14 is provided on the center side step 15b. Further, a boss 15f for fixing the printed board 13 by welding and a boss 15g for positioning the printed board 13 are formed at appropriate positions of the sponge storage section 15c.

The outer periphery of the rubber sponge 14 has a smoke detection section main body 15.
Has a ring shape large enough to fit into the sponge storage portion 15c. The rubber sponge 14 also has a smoke detection section main body 15.
Four radial notches 14d fitted into the three positioning projections 15d, and positioning projections 15e of the smoke detection section main body 15.
Positioning notch 14e fitted to
The two bosses 15f and 15g are formed with two long holes 14f and through holes 14g.

Notch 14 formed in rubber sponge 14
As shown in FIG. 3, each of d, the long hole 14f, and the hole 14g is formed symmetrically with respect to a center line passing through the positioning notch 14e. Therefore, the rubber sponge 14 has no front and back surfaces, and can be incorporated into the sponge storage portion 15c of the smoke detection unit main body 15 without considering the front and back.
For this reason, the mounting mistake of the rubber sponge 14 does not occur, and the waterproofing can be surely performed.

FIG. 4 is a sectional view of the waterproof structure of the present invention in an assembled state. The peripheral edge of the lower surface of the terminal board 11 forms a double annular peripheral wall so that the peripheral wall 15a of the smoke detection section main body 15 is fitted. Here, the step of the sponge storage section 15c of the smoke detection section main body 15 is about 1 mm, and the thickness of the rubber sponge 14 is about 1.1 mm. For this reason, in the assembled state of FIG. 4, the printed circuit board 13 presses the rubber sponge 14 against the sponge accommodating portion 15c and compresses the rubber sponge.
Contact surfaces are sufficiently adhered to each other.

The peripheral wall portion 11 inside the peripheral edge of the terminal board 11
When the terminal board 11 and the smoke detection section main body 15 are fitted together,
The smoke detector main body 15 is formed to have a length slightly protruding into the sponge storage portion 15c from the surface of the step portion 15b. For this reason, in the assembled state of FIG. 4, the tip of the peripheral wall portion 11a presses the rubber sponge 14, and the rubber sponge 14 is
Closely fix to the 5 side.

The smoke detection unit cover for the smoke detection unit body 15
The mounting of the engagement piece 1 is performed by rotating the smoke detection section main body 16.
66 is fitted to the engagement receiving portion 151. Where go
As the sponge 14, for example, Hashimoto Rubber Co., Ltd.
C-4305 can be used. This rubber sponge
The density is 190 ± 30kg / m ^Three, Tensile strength
5kg / cm^ThreeElongation is 150% or more, heat shrinkage
Is 1.5% or less, compression set is 30% or less, 25% pressure
Shrink load is 631-950 g / cm^Three, Water absorption rate is less than 5%
Below, thermal conductivity is 0.0505Kcal / mH ° C, hardness is
It has a characteristic of 25 ± 5.

In FIG. 4, there are three possible routes for corrosive gas or moisture to enter the circuit housing in which the printed circuit board 13 is incorporated. First, the intrusion path is to inject corrosive gas or moisture from outside the periphery of the terminal board 11 through the periphery of the smoke detection section main body 15. However, the rubber sponge 14 is thicker than the step of the sponge accommodating portion 15c formed in the smoke detector main body 15, and the terminal board 11
A rubber sponge 14 is formed at the tip of the peripheral wall portion 11a inside the peripheral edge of
Is pressed, and the space between the smoke detection unit main bodies 15 is sealed, so that the invasion path can be reliably shut off.

The intrusion path is such that corrosive gas or moisture tends to flow through the fitting portion between the smoke detection unit cover 16 and the smoke detection unit main body 15. However, rubber sponge 14
Is pressed by the mounting and fixing of the printed circuit board 13 and is in close contact with the sponge storage section 15c, so that the intrusion path can be reliably blocked. Further, the intrusion path is such that corrosive gas or the like in the smoke detection chamber tries to flow from the gap with the printed circuit board 13 through the hole of the smoke detection section main body 15. However, since the rubber sponge 14 is pressed and closely adhered to the sponge accommodating portion 15c when the printed circuit board 13 is fixed, the intrusion path can be reliably blocked.

Next, a description will be given of a detachable assembly structure of the smoke detection section main body 15 and the smoke detection section cover 16 according to the present invention. FIG.
Indicates a state in which the smoke detection unit cover 16 is attached to the smoke detection unit main body 15. The smoke detection unit cover 16 is a cylindrical cap-shaped member opened to the detection unit main body 15 side, has a flange portion 161 on the fitting side, and has a leading edge of the flange portion 161 as a tapered peripheral portion 162. A cover fitting recess 153 is formed on the cover mounting surface of the smoke detection unit main body 15, and the cover fitting recess 153 is formed on the outer surface 1 by a taper step 155.
It is lowered to 54.

The tapered step 155 of the cover fitting recess 153
Is a tapered surface having the same conical surface as the tapered peripheral edge 162 of the smoke detection unit cover 16, but when the tapered peripheral edge 162 is pushed into the tapered step 155, the front end surface of the smoke detection unit cover 16 is fitted with the cover. The dimensional difference is made to have a small gap with the mounting surface of the joint recess 153. That is, when the smoke detection section cover 16 is incorporated into the cover fitting king section 153, first, the tapered peripheral edge 162 of the smoke detection section cover 16
5, the dimensional relationship is created such that the tip surface of the smoke detection unit cover 16 is pressed against the surface of the cover fitting recess 153 when the smoke detection unit cover 16 is further pushed in. Conversely, the tip surface of the smoke detection unit cover 16 must not first contact the surface of the cover fitting recess 153.

Further, even when the cover fitting concave portion 153 is formed, the smoke detecting portion main body 15 has a uniform thickness as a whole and does not have an unnecessary thick portion. The reverse convex shape is formed. This inverted convex shape is the same as the rubber sponge 14 that realizes the waterproof structure of the circuit housing described above.
It is used to form the sponge housing portion 15c, and is made thinner.

Next, a description will be given of a detachable fitting structure of the smoke detector cover 16 with respect to the smoke detector main body 15. FIG. 6 is an explanatory view showing the smoke detection unit cover 16 in a state of being assembled to the smoke detection unit main body 15 in a cross section taken along line AA of FIG. 5. Smoke detector cover 16
Has an opening 163 at a plurality of positions on a cylindrical peripheral wall, and an insect repellent net 164 is mounted around the periphery. Each opening 16
A plurality of labyrinths 165 are arranged inside 3.

With the installation of the smoke detection section cover 16, a smoke detection chamber 30 is formed inside. The LED arranged in the smoke detection room 30 is in the light emitting unit cover 21 mounted on the smoke detection unit main body 15 side, and the PD is in the light receiving unit cover 22. Engagement receiving portions 151 are arranged at three locations around the cover mounting fitting concave portion 153 of the smoke detection portion main body 15, and engagement pieces 166 formed at the three locations on the smoke detection portion cover 16 are turned around. Has been fitted.

FIG. 7 shows the engagement structure. The engagement receiving portion 151 formed in the smoke detection portion main body 15 has a rectangular engagement groove 156 opened to the side and the inside, into which the engagement piece 166 of the smoke detection portion cover 16 is fitted by being turned. Combine.
A fitting groove 167 is formed at the tip of the engagement piece 166,
Correspondingly, a fitting projection 157 is formed in the engagement groove 156 of the engagement receiving portion 151 so that a click feeling can be obtained when the two members are turned together to perform positioning and fixing. ing.

Further, the engagement receiving portion 151 of the smoke detecting portion main body 15 is provided.
In contrast, a stopper 158 is formed at an interval at which the engaging piece 167 on the cover side enters from above, and determines the relative position at which the smoke detection unit cover 16 is incorporated to start turning. This is because a large number of labyrinths 165 are formed inside the smoke detection unit cover 16 as shown in FIG. 6, and the rotatable range is limited with respect to the members on the smoke detection unit main body 15 side.

Therefore, when assembling the smoke detecting section cover 16, as shown in FIG. 8, first, the engaging piece 166 is aligned along the stopper 158 and is inserted between the engaging receiving section 151 and then. The smoke detector cover 16 is turned clockwise to fit the engagement piece 166 into the engagement receiver 151. In such assembling of the smoke detector cover 16, as shown in FIG. 5, the taper peripheral portion 162 of the smoke detector cover 16 is turned while being in contact with the tapered step 155 of the cover fitting recess 153 of the smoke detector main body. And are fixed by being pressed together, and are joined in a close contact state by being fitted to each other with the tapered surfaces, so that there is no gap or play.

If it is desired to remove the smoke detection section cover 16 during cleaning or the like, it is sufficient to turn it counterclockwise in FIG. 8. In this case, the engaging piece 167 hits the stopper 158 and stops. It does not damage the labyrinth. Next, the procedure for assembling the photoelectric smoke detector of the present invention will be described. In FIG. 1, first, L
The EDs 18, 19 and PD 20 are incorporated, and then the smoke detecting LED 18 is provided with the light emitting unit cover 21 and the test LED.
A light receiving unit cover 22 is attached to 19 and the PD 20, and a shield cap 23 is attached to the light receiving unit cover 22. In this state, the smoke detection unit cover 16 is assembled.

Next, the rubber sponge 14 is put into the sponge accommodating portion 15c of the smoke detection section main body 15, and the lead wires of the LEDs 18, 19 and the PD 20 penetrating the smoke detection section main body 15 and the shield cap 23 are attached to the printed circuit board 13. Let through. In this state, since the rubber sponge 14 is thicker than the step of the step 15b of the smoke detection section main body 15, the lower surface of the printed board 13 is floating above the step 15b above the smoke detection section main body 15. Then, the boss 15f of the smoke detection unit main body 15 is welded while pressing the printed circuit board 13 to compress the rubber sponge 14,
The printed circuit board 13 is fixed to the smoke detection unit main body 15.

Next, the respective lead wires of the LEDs 18, 19 and the PD 20 and the shield cap 23 are soldered onto the substrate 13, and then the smoke detection section cover 16 is assembled into an assembly such as the smoke detection section main body 15, and then the smoke detection section. Shielding case 12, terminal board 11, fitting 1
0 is incorporated and fixed with screws 24. In this case, the conductive pattern of the printed circuit board 13 and the fitting 10 are electrically connected by the screw 24. Rubber sponge 14
Is installed in a state where it is pressed by the tip of the peripheral wall portion 11 a inside the peripheral edge of the terminal board 11. Finally, the outer cover is fitted to the terminal board 11, and the assembly of the sensor main body is completed.

Although the above embodiment describes the structural positional relationship between the top, bottom, left and right with the sensor mounted on the ceiling, this is a relative one and the orientation of the sensor is If it is reversed, it goes without saying that the relationship is reversed accordingly.

[0036]

As described above, according to the present invention, the tapered peripheral portion of the smoke detection section cover is pressed against the taper step of the cover fitting concave portion formed in the smoke detection section main body.
Since it is assembled and fixed detachably by turning it in, the taper step acts like a wedge with a conical hole and the tapered peripheral edge part as a conical part. Without this, the smoke detection unit cover is assembled and fixed.

Also, the thickness of the surface formed with the cover fitting concave portion of the smoke detecting portion main body is made uniform, and the inverted convex shape formed on the opposite surface is used for the sponge storage portion of the rubber sponge for waterproofing. Thus, the thickness of the sensor can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded view showing an embodiment of a photoelectric smoke detector according to the present invention.

FIG. 2 is an exploded view of the printed circuit board, the rubber sponge and the smoke detection unit main body of FIG. 1;

FIG. 3 is a plan view of a symmetrical relationship between the rubber sponge and the smoke detection unit main body of FIG. 1;

FIG. 4 is a sectional view of a portion having a waterproof structure according to the present invention.

FIG. 5 is an explanatory view of an assembling structure of the smoke detection unit cover of the present invention.

FIG. 6 is an explanatory diagram of an assembled state of a smoke detection unit cover with respect to a smoke detection unit main body.

FIG. 7 is an explanatory view of an engagement structure by turning a smoke detection unit cover in;

FIG. 8 is an explanatory diagram of attachment / detachment of the smoke detection unit cover by turning it around.

[Explanation of symbols]

 10: Fitting fitting 11: Terminal board 11a: Barrier part 12: Shield case 13: Printed circuit board 13a: Hole 14: Rubber sponge 14d: Notch part 14e: Positioning notch part 14f: Long hole 14g: Through hole 15: Smoke detector Main body 15a: Peripheral wall 15b: Step 15c: Sponge storage 15d: Projection 15e: Positioning projection 15f: Boss (welding) 15g: Boss (for positioning) 16: Smoke detector cover 17: Outer cover 18, 19 : LED 20: Light receiving element (PD) 21: Light emitting unit cover 22: Light receiving unit cover 23: Shield cap 24: Screw 30: Smoke detection room 151: Engagement receiving unit 153: Cover fitting king 154: Outer surface 155: Taper step 156: Engagement groove 157: Fitting protrusion 161: Flange part 162: Tapered peripheral part 163: Opening part 164: Insect repellent net 65: Labyrinth 166: engaging piece 167: engaging groove

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G08B 17/10 H05K 5/02

Claims (3)

(57) [Claims] 1. A smoke detector main body having a cover fitting concave portion having a tapered step formed on a mounting surface of a smoke detector, and the cover fitting concave portion formed in the smoke detector main body. And a smoke detection section cover having a tapered peripheral portion formed opposite to the tapered step, wherein the smoke detection section cover is fitted to a cover fitting section of the smoke detection section main body, and the An assembling structure of a smoke detector, wherein a tapered peripheral portion is pressed and fixed to make close contact. 2. The smoke detector according to claim 1, wherein an opposite surface of the smoke detector main body, in which the cover fitting concave portion is formed, has an inverted convex shape. An assembling structure of a smoke detector, characterized in that the thickness of the main body is made uniform. 3. The assembly structure for a smoke detector according to claim 2, wherein said stepped portion having said inverted convex shape is a sponge storage portion, and a rubber sponge for waterproofing is disposed in said sponge storage portion. A smoke detector assembly structure characterized by the following.