JPS6020679Y2 - Iron cover for underground structures - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of iron covers for underground structures.The purpose of this invention is to prevent gas from occurring in underground structures such as manholes and when the internal pressure rises. The aim is to prevent accidents such as the iron lid being blown off due to pressure, and specifically, a ventilation plate made of a porous material that becomes breathable only when the internal pressure rises is fitted into a part of the iron lid. There is a particular thing.

The gist of the present invention is to form one or more cylindrical holes 2 at appropriate locations on the iron lid 1, and to form a diameter-reducing hole in the upper part of the hole 2, either integrally with the iron lid 1 or separately. The ventilation plate 4 is fitted into the hole 2 so that the upper surface 4' of the ventilation plate 4, which is made of a porous material that forms the stepped portion 3 and becomes breathable when internal pressure is applied to the reduced diameter stepped portion 3, is in contact with the upper surface 4' of the ventilation plate 4. This is an iron lid for an underground structure in which a receiving member 5 for receiving the lower surface 4'' of the ventilation plate 4 is fixed to iron M1.

The illustrated embodiment was implemented on a bolt-tight manhole iron cover designed to withstand internal pressure.
The first embodiment shown in the figure has a small hole 2' on the front side of the iron lid 1.
, 2' are bored around the circumference of the screw hole 1a, and a receiving step concentric with the hole 2 is formed on the back side of the iron lid 1 so as to form a diameter-reducing step 3 on the lower side. 1', and drill small holes 5', 5' and a screw hole 5a in corresponding positions of the small holes 2', 2' and screw hole 1a in the receiving step 1', respectively;
Insert the bolt 6 from the screw hole 1a through the screw insertion hole 4a of the circular ventilation hole 4 into the screw hole 5a of the receiving member 5, and tighten it with the nut 7, so that the ventilation plate 4 is received with the diameter-reduced step 3. It is designed to be held between members 5.

Next, in the second embodiment shown in FIGS. 5 and 6, the iron lid 1
By forming a large-diameter step 1'' concentric with the hole 2 on the front side of the disk, and fitting a disk 8 having small holes 2', 2' and a screw hole 1a into the large-diameter step 1'', A diameter-reducing stepped portion 3 is formed.
The other configurations are the same as in the first embodiment.

In addition, in the third embodiment shown in FIGS. 7 and 8, the opening 2'' of the hole 2 is made smaller in diameter than the inverted truncated conical portion 2'', thereby forming a diameter-reducing step at the top of the hole 2. A receiving member 5 for receiving and holding the circular ventilation plate 4 is formed of a ring-shaped soft material such as a rubber material and is shaped to be forcefully fitted into the inverted truncated conical portion 2''.

The fourth embodiment shown in Figs. 9 and 10 has bolt holes 5a', 5a' on the left and right sides of the ring-shaped receiving member 5, and the bolts wound into the bolt holes 5a', 5a/. 6', 6
By screwing directly into the iron lid 1, the ventilation plate 4 is held between the diameter-reduced step part 3.

Furthermore, in the fifth embodiment shown in FIGS. 11 and 12, a screw 9 is formed on the outer periphery of the ring-shaped receiving member 5 on the inner surface of the lower part of the hole 2 of the iron cover 1, and is screwed into an internal thread 10. According to
The ventilation plate 4 is designed to be stopped.

The ventilation plate 4 is made of a breathable porous material such as ABS resin, polyethylene, acrylic resin, or other resin with very fine particles, such as silicone or polyethylene emulsion, and a lubricant, admixture, preservative, leveling agent, etc. The material is immersed in a resin solution containing a fungicide, a penetrating water repellent, and a rust preventive agent, with water added as a solvent, and the resin solution is sufficiently filled into the many micropores of the porous material. Although it was made by taking it out and air drying it, it is also possible to make it by other methods.

Since the present invention has the above-mentioned structure, even if gas is generated inside an underground structure such as a manhole and the internal pressure increases, the gas will flow outside through the ventilation plate 4 made of a porous material that becomes breathable when the internal pressure is applied. Since the gas is discharged, accidents such as gas popping out of manholes can be prevented.

Moreover, since the ventilation plate 4 has the characteristic that it becomes breathable only when internal pressure is applied, there is no risk of rainwater entering underground structures such as manholes from the ventilation plate 4 even if it accumulates on the surface of the iron lid 1. The function of the closed iron lid can be fully demonstrated.

In particular, with the configuration of the present invention, the ventilation plate 4 is held between the diameter-reducing step portion 3 and the receiving member 5, so the structure is simple, it can be held securely, and the ventilation plate 4 can be easily replaced. It has a certain effect.

[Brief explanation of drawings]

The drawings relate to the iron cover for underground structures according to the present invention.
Fig. 1 is a plan view of the first embodiment, Fig. 2 is a longitudinal sectional front view of the main parts of the same, Fig. 3 is a plan view of the same, Fig. 4 is a bottom view of the same, and Fig. 5 is a main part of the second embodiment. 6 is a plan view of the same as above, FIG. 7 is a longitudinal sectional front view of the main part of the third embodiment, FIG. 8 is a bottom view of the same, and FIG. 9 is a main part of the fourth embodiment. 10 is a top and bottom view of the same, FIG. 11 is a longitudinal sectional front view of essential parts of the fifth embodiment, and FIG. 12 is a top view of the same. 1... Iron lid, 2... Hole, 3...
・Reducing diameter step, 4... Ventilation plate, 4'...
Top surface, 4″...Bottom surface, 5...Reception member.

Claims (1)

[Scope of utility model registration request] One or more cylindrical holes 2 are formed at appropriate locations in the iron M1, and a diameter-reducing stepped portion 3 is formed on the upper part of the hole 2, either integrally with the iron lid 1 or separately. The upper surface 4 of the ventilation plate 4 prevents the porous material from becoming breathable when internal pressure is applied to the reduced diameter step 3.
This iron cover for an underground structure is constructed by fitting the ventilation plate 4 into the hole 2 so that the two sides are in contact with each other, and fixing a receiving member 5 to the iron cover 1 to receive the lower surface 4'' of the ventilation plate 4.