JPH082796Y2 - Water drainage structure of sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a drainage structure of a sensor for discharging water accumulated in a main body cover of the sensor to the outside.

[Prior Art] Conventionally, in an ionization type or photoelectric type fire detector, a main body cover housing a detector circuit and a detection mechanism, and a smoke inlet provided to cover the detection mechanism portion of the main body cover. The sensor body is configured by fitting with an outer cover equipped with
This sensor body is detachably attached to the sensor base installed on the ceiling surface.

When the sensor is installed on the ceiling surface, etc., water may enter inside the sensor body cover along the ceiling surface, or water may accumulate in the sensor due to dew condensation inside the cover due to humidity. Since the sensor circuit may malfunction, a water drain hole is provided in the lower part of the main body cover so that the water accumulated in the cover is discharged to the outside.

[Problems to be Solved by the Invention] However, in such a conventional sensor drainage structure, since the drainage hole is formed in the lower surface of the main body cover, the drainage hole is formed when the sensor is installed. It was exposed to the outside, and the area around the drainage hole became dirty and blackened for a long time, causing a problem that the appearance of the sensor deteriorated.

The present invention has been made in view of the above conventional problems, and a drainage structure of a sensor capable of draining water without separately providing a drainage hole by effectively utilizing the mounting structure of the main body cover and the outer cover. The purpose is to provide.

[Means for Solving the Problem] In order to achieve this object, according to the present invention, in a sensor having a structure in which a main body cover and an outer cover are fitted to each other, a rectangular shape is formed around a fitting side edge of the outer cover. A plurality of fitting pieces having fitting holes opened on the lower side are projected, and a fitting receiving hole having a slit-shaped opening is formed at a fitting position of the main body cover facing the fitting piece, A water draining structure is provided in which an inner wall surface of the fitting receiving hole is provided with a wedge-shaped engaging projection that is tapered higher than an insertion side that engages the tip of the fitting hole of the fitting piece.

[Operation] In the water drainage structure of the sensor of the present invention having such a configuration, the water drainage passage is formed in the fitting portion of the body cover and the outer cover, so that the water drain hole is formed in the body cover. It is not necessary to provide it separately, and by integrating it with the cover fitting structure, the water draining structure can be simplified and the appearance of the sensor can be improved.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of an ionization type smoke detector having a drainage structure of the present invention.

In FIG. 1, reference numeral 1 denotes a sensor body, which is detachably attached to a sensor base 2 installed on a ceiling surface.

The sensor main body 1 has a sensor cover formed by fitting a main body cover 3 on the side of the sensor base 2 and an outer cover 5 having a smoke inlet 4 in the periphery, and an insulating plate 6 provided inside the sensor cover. An internal electrode 7 having a radiation source at its center, an intermediate electrode 8 having an opening hole for passing radiation from the radiation source, an external electrode provided so as to cover the outside of the intermediate electrode 8 and provided with a smoke inlet in the periphery. 9 is attached. A circuit housing portion provided with a shield case 11 is provided on the back surface side of the insulating plate 6, and a circuit board 10 having a sensor circuit mounted therein is housed in the circuit housing portion.
Further, the FET 12 is incorporated on the back surface side of the insulating plate 6, the electrode lead of the intermediate electrode 8 penetrating the insulating plate 6 is soldered to the lead of the FET 12, and the FET 1 is soldered with this electrode lead.
The housing of No. 2 is filled with a heat-melting synthetic resin and is in an insulating sealed state (potting state).

FIG. 2 shows an exploded view of the sensor body 1 shown in FIG.

In FIG. 2, a contact pin 13 for electrically connecting to the circuit board 10 is provided in the internal opening 3a of the main body cover 3, and the back side of the contact pin 13 is fitted to the sensor base 2. The fitting terminal 14 of is fixed. The shield case 11 is incorporated into the internal opening 3a of the body cover 3,
After the shield case 11, the circuit board 10 and the insulating plate 6 are assembled.

An internal electrode 7 made up of an assembly of an electrode member 7a, a radiation source 7b and an electrode cover 7c is attached to the center of the insulating plate 6,
An intermediate electrode 8 having a donut shape is attached to the outside of the internal electrode 7, and an external electrode 9 covering the intermediate electrode 8 and having a smoke inlet 9a in the periphery is attached. The attachment of the external electrode 9 to the side of the insulating plate 6 is performed by the contact fitting 15, and the contact fitting 15 connects the external electrode 9, the insulating plate 6 and the circuit board 10.
To the contact portion 16 of the shield case 11 and the tip of the contact fitting 15 of the circuit board 10 is soldered to the ground pattern thereof, thereby connecting the shield case 11 and the opening of the shield case 11 to each other. The external electrode 9 having a shielding function is electrically connected, and the shield side is electrically connected to the ground portion of the circuit board 10.

Following the outer electrode 9, an outer cover 5 having a smoke inlet 4 around the bottom plate 17 and an insect screen 18 is attached. The outer cover 5 has a plurality of fitting pieces 20 projecting from the periphery of the fitting side. The fitting pieces 20 are formed on the fitting position of the main body cover 3 as will be described later. The outer cover 5 can be attached to the main body cover 3 by being fitted into the holes.

FIG. 3 shows the body cover 3 and the outer cover 5 shown in FIGS.
FIG. 4 is a cross-sectional explanatory view showing a drainage structure of the present invention when taken out. The outer cover 5 is shown in a half cross section divided into right and left with respect to the center line.

In FIG. 3, four fitting pieces 20 are projected on the periphery of the fitting side (upper side) of the outer cover 5 in this embodiment, and the fitting piece 20 has a rectangular shape and a lower part. A fitting hole 22 that opens to the side is formed.

On the other hand, a fitting receiving hole 24 having a slit-shaped opening is formed at the fitting position on the body cover 3 side.
A wedge-shaped engagement projection 28, which is tapered higher than the insertion side, is integrally formed on the inner wall surface 26 of 24.

FIG. 4 shows a fitting structure of the outer cover 5 to the main body cover 3 in the IV-IV cross section of FIG.

In FIG. 4, the fitting piece 20 projecting to the fitting side of the outer cover 5 is rectangular and has a fitting hole 22 opened downward, and the body cover receiving the fitting piece 20 is fitted. Inner wall surface 26 inside the fitting receiving hole 24 having a slit-shaped opening on the 3 side
A wedge-shaped engaging projection 28 is formed on the upper surface of the wedge so as to be tapered higher than the insertion side.

FIG. 5 is a sectional view showing a fitting state of the fitting piece 20 of the outer cover shown in FIGS. 3 and 4 and the engaging projection 28 of the main body cover 3.

In FIG. 5, as shown in FIGS. 3 and 4, the fitting piece 20 of the outer cover 5 is inserted into the fitting receiving hole 24 of the body cover 3 from below.
, Insert the body cover 3 into the upper part of the fitting hole 22 of the fitting piece 20.
The engaging projection 28 formed on the inner wall surface 26 of the above is fitted as shown in the drawing to prevent the engagement from coming off. In such a fitted state, the fitting hole 22 formed in the fitting piece 20 of the outer cover 5 is rectangular and opens downward. Drainage passage 30 shown by the arrow that goes outside
Is formed.

Therefore, even if water flows into the main body cover 3 along the ceiling surface when the sensor main body is attached to the sensor base installed on the ceiling surface, or if water collects in the main body cover 3 due to dew condensation due to intrusion of moisture, Fitting hole for fitting piece 20 of outer cover 5
Water can be discharged from the inside of the body cover 3 to the outside through the drainage passage 30 formed by 22.
It is possible to reliably prevent the water accumulated inside from entering the storage portion of the circuit board 10 and causing a malfunction.

Since the drainage passage 30 is formed integrally with the fitting portion of the outer cover 5 with respect to the body cover 3, it is not necessary to separately provide a drainage hole in the lower portion of the body cover 3, and the drainage passage 30 is further formed in the fitting portion. The opening portion of the drainage passage 30 can hardly be recognized as a drainage hole from the outside, and it is possible to prevent the appearance of the sensor from being unattractive when a conventional drainage hole is separately provided.

In the embodiment described above, the fitting holes 22 that are rectangular and open downward are formed in all of the fitting pieces 20 projecting from the fitting side edge portion of the outer cover 5, so that The case where the water drainage passages 30 are formed in all the fitting portions in the mounted state has been taken as an example, but it is sufficient to provide the water drainage passages 30 at one location or two locations. The fitting piece 20 that does not have a rectangular fitting hole 22a that does not open downward as shown in FIG. 6, and the fitting hole that does not open downward in the fitting receiving hole 24 of the body cover 3 as shown in FIG. The fitting piece 20 with the 22a formed therein may be fitted into the fitting projection 28 to prevent the fitting piece 20 from coming off, and the fitting receiving hole 24 may be closed by fitting the fitting piece 20.

In addition, it is desirable that the drainage passages be provided at three or more locations in order to prevent the influence of inclination when the sensor is installed.

Further, although the above-mentioned embodiment has been described by taking the ionization type smoke detector as an example, any detector can be used as long as it is a detector having a fitting structure of the main body cover 3 and the outer cover 5 having a smoke inlet. The drainage structure of the present invention can be directly applied to the sensor having a structure.

[Effects of the Invention] As described above, according to the present invention, the water draining structure is integrally provided by effectively utilizing the fitting structure for fitting the main body cover and the outer cover. There is no need to provide a drainage hole, the water drainage structure can be simplified by integrating it with the fitting structure, and the opening of the water drainage passage can be made almost inconspicuous from the outside, so compared to a sensor with a separate drainage hole. The appearance of the sensor can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an ionization type smoke detector having a drainage structure of the present invention; FIG. 2 is an exploded view of the detector body of FIG. 1; and FIG. 3 is a body cover of FIGS. 4 is a sectional view showing the outer cover and the outer cover taken out; FIG. 4 is a sectional view taken along line IV-IV in FIG. 3; FIG. 5 shows a fitting structure of the main body cover and the outer cover for realizing the drainage structure of the present invention. Sectional drawing; FIG. 6 is an explanatory view of the fitting portion of the outer cover when the drainage structure is not provided; FIG. 7 is an explanatory view of the fitting structure of the main body cover and the outer cover where the drainage structure is not provided. is there. 1: Sensor body 2: Sensor base 3: Body cover 4: Smoke inlet 5: Outer cover 20: Mating piece 22, 22a: Mating hole 24: Mating receiving hole 26; Inner wall surface 28: Engagement protrusion

Claims (1)

[Scope of utility model registration request] 1. A sensor having a structure in which a main body cover and an outer cover are fitted to each other, wherein a plurality of fitting pieces each having a fitting hole that is rectangular and has a downward opening is provided on a periphery of a fitting side of the outer cover. A fitting receiving hole having a slit-shaped opening is formed at a fitting position of the main body cover protruding and facing the fitting piece, and the fitting piece is formed on an inner wall surface of the fitting receiving hole. A water draining structure for a sensor, characterized in that a wedge-shaped engaging protrusion is provided which is tapered higher than an insertion side for engaging the tip of the fitting hole.