JPH0442995A - Air tight housing having safety plug - Google Patents

Abstract

PURPOSE:To prevent damage of a hermetically sealing housing by clamping together with an outer wall of a housing having a hermetically sealing structure a plate member of a shape larger than an opening formed partly at the wall of the housing in a state covering the opening by a nut and a bolt having a head of a size smaller than the opening. CONSTITUTION:A plate member 11 of a shape larger than an opening 5 formed partly at an outer wall of a housing 1 having a hermetically sealing structure is formed in a structure clamped together with the wall in a state covering the opening by a nut 13 and a bolt 12 having a head of a size smaller than the opening. If a pressure difference between the interior and the exterior of the housing 1 exceeds a predetermined pressure, the member 11 is deformed to a substantially cup state, and removed through the opening together with the bolt and the nut.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a safety plug that can be applied to an airtight enclosure such as a wireless repeater installed outdoors, and aims to prevent the airtight enclosure from being destroyed. A plate member having a shape larger than an opening formed in a part of the outer wall of the structure's casing is connected to the outer wall by a nut and a bolt having a head smaller than the opening while covering the opening. It has a structure in which they are fastened together, and when the pressure difference between the inside and outside of the airtight casing exceeds a predetermined pressure, the plate member is deformed into a substantially bowl shape and passes through the opening together with the bolt and nut. It is configured to include a safety stopper that can be pulled out.

[Industrial application field]

TECHNICAL FIELD The present invention relates to a safety plug that can be applied to an airtight casing of a wireless repeater or the like installed outdoors.

Wireless repeaters installed outdoors have a waterproof structure to prevent raindrops from penetrating inside, and therefore the housing has a completely airtight structure with no air vent holes.

If the casing is made to have an airtight structure in this way, there is a risk that the casing may be destroyed, for example, when the temperature rises under the scorching sun, the air expands, and the internal pressure rises.

Therefore, the airtight casing needs to have a structure that also takes into consideration the above pressure increase.

[Conventional technology]

Conventional wireless repeater casings were not designed to prevent damage due to pressure rise.

[Problem to be solved by the invention]

Therefore, there is a risk of an accident in which the casing breaks down due to an abnormal increase in internal pressure under the scorching sun, which poses a safety problem.

In view of the above, an object of the present invention is to provide an airtight casing having a safety plug that can prevent destruction of the airtight casing.

[Means to solve the problem]

The present invention includes a plate member having a larger shape than an opening formed in a part of the outer wall of a housing having an airtight structure, and a nut and a bolt having a head smaller than the opening while covering the opening. It has a structure in which it is fastened together with the outer wall, and when the pressure difference between the inside and outside of the airtight casing exceeds a predetermined pressure, the plate member is deformed into a substantially bowl shape, and the plate member is deformed together with the bolt and nut. The safety plug is configured to come out through the opening.

[Effect]

The structure in which the plate members are fastened together with the outer wall using bolts and nuts does not impair the airtight structure of the housing.

The structure in which the head of the bolt is smaller than the opening allows the safety plate to deform into a bowl shape, and allows the safety plate, bolt, and nut to slip out of the opening.

〔Example〕

FIG. 1 shows a wireless repeater housing l according to an embodiment of the present invention.

A wireless relay electronic circuit unit 2 is built in this housing 1.

The housing l has an airtight structure consisting of a box-shaped housing main body 3 and a bottom cover 4 fixed to cover this opening.
It is installed outdoors in the orientation shown in Figure 1 with the top facing down.

The bottom cover 4 has a circular opening 5 in its center, in which a safety plug 1o, which is an important part of the present invention, is provided.

The safety plug 10 has a structure consisting of an annular safety plate 11, a bolt 12, and a nut 13, as shown enlarged in FIGS. 2 to 4.

The diameter d of the safety plate 11 and the diameter d2 of the opening 5 are d,
The relationship is slightly larger, ie, d,>d.

The diameter d2 of the head 12a of the bolt 12 is set to be slightly smaller than the diameter d of the opening 5. That is, d<d2.

Diameter dl+ d2n d3 Which relationship is d, > d2
>d.

If the thickness of the safety plate is t, the diameters d and d2 are the diameters d,
It is determined that the dimension is approximately d2, which is the sum of 2Xt and 2Xt.

Here, the thickness t of the safety plate 11 is determined by the pressure P set as the pressure inside the housing 2 when the safety plug 1o comes out. In this embodiment, the safety plug 1o is set to come off when the pressure P exceeds 1.4 atmospheres.

The nut I3 consists of a main body portion 13a fitted into the opening 5 and a flange portion 13b on this end side.

The safety plate 11 is arranged on the top surface 4a side of the bottom cover 4, and is screwed into the nut 13 fitted into the opening 5 from the bottom surface 4b side of the bottom cover 4 and from the top surface 4a side of the bottom cover 4. The bolts 12 are tightened together with the bottom cover 4, and the bottom cover 4 is pressed against the top surface 4a of the bottom cover 4 and fixed in a state where the opening 5 is closed.

15, 16, and 17 are all seal members.

As a result, the safety plug 10 also has an airtight structure, and the casing l has a completely airtight structure as a whole, so that raindrops do not enter inside.

Next, the operation of the safety plug 10 will be explained with reference to FIGS. 5 and 6.

Under the scorching sun, when the temperature of the air inside the casing 1 rises and expands, and the pressure of the casing 1 rises, the head 12 of the bolt 12
A pressure P is applied to a to push it into the opening 5.

If this pressure P exceeds 1.4 atmospheres, the bolt head 12a
is a punch of a press drawing machine, and the bottom cover 4 functions similarly to a goo, as shown in FIG. The bolt head 12a sinks into the opening 5 with upward bending. The safety plate 11 is deformed into a substantially bowl shape.

In this state, the safety plate 11 is pushed into the opening 5 together with the bolt head 12a, passes through the opening 5, and comes out of the opening 5 as shown in FIG.

As a result, the inside of the casing 1 is communicated with the atmosphere through the opening 5, the pressure inside the casing 1 is released, and damage to the casing 1 is prevented.

Additionally, the safety plug 10 may be installed upside down.
Wear. This configuration is effective when applied in an environment where the external pressure of the housing is abnormally higher than the internal pressure (for example, when a radio buoy is on the ocean and is submerged in the sea).

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to prevent the airtight casing itself from being destroyed by pressure without impairing the airtightness of the airtight casing, and to ensure safety.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an airtight casing having a safety plug according to an embodiment of the present invention, Fig. 2 is an enlarged view of the safety plug part in Fig. 1, and Fig. 3 is a safety plug shown in Fig. 2. Figure 4 is a plan view of the safety plug shown in Figure 2. Figure 5 is a diagram showing the initial state in which the safety plug has come out of the opening. Figure 6 shows the state in which the safety plug has come out of the opening. FIG. 11a is an outer circumference side part, 11b is an upwardly bent outer circumference side part, 12 is a bolt, 12a is a head, 13 is a nut, 13a is a main body part, and 13b is a flange part. Patent applicant Fujitsu Ltd. In the diagram, is the wireless repeater housing, is the wireless relay electronic circuit unit, is the main body of the housing, is the bottom cover opening, 0 is the safety plug, 1 is the safety plate, 1 color Tanchu Securities Book 1 Figure 13a

Claims (2)

[Claims] (1) A plate member (11) having a larger shape than the opening (5) formed in a part of the outer wall (4) of the airtight housing (1),
With the opening (5) covered, the bolt (12) is tightened together with the outer wall (4) using a nut (13) and a bolt (12) having a head (12a) smaller in size than the opening (5). When the pressure difference between the inside and outside of the airtight casing exceeds a predetermined pressure, the plate member is deformed into a substantially bowl shape (Fig. 5), and the bolt (12) and nut ( 13) An airtight housing having a safety plug, characterized in that the safety plug is configured to exit through the opening (5). (2) The above outer wall is a bottom cover (
4) The airtight casing having a safety plug according to claim 1, wherein the safety plug (10) is provided on the bottom cover.