JP2000064324A - Heat insulative inner cover for manhole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve functions by closely sticking and holding a circular heat insulation board in which a tube made of a flexible material is attached to the outer peripheral face and a drain hole is formed, in a manhole. SOLUTION: A ring-shaped tube 7 made of a flexible material such as rubber or the like is fitted in a groove 5B formed on the outer peripheral face of a circular heat insulation board 5 provided with drain holes 5A, and the heat insulation board 5 is inserted in the manhole 2 with a distance from an iron cover and held horizontally. Then, air is injected in the tube 7 from an air injection hole 7A to expand it, and the heat insulation board 5 is closely stuck on the inner peripheral face of the manhole 2 to insulate heat within the manhole 2 and prevent snow cover on the iron cover from melting. When necessary, a float type seal is fitted to the hole 5A and accumulated water on the heat insulation board 5 is drained into the manhole 2, and further, when there is no water on the heat insulation board 5, the hole 5A is closed to prevent dissipation of heat in the manhole. In this way, the heat insulation effect can be greatly improved and the heat insulation board can be prevented from being chipped off at the edge when fitting it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner lid for heat insulation of a manhole, and in particular, an excellent heat insulation effect is obtained as a result of always maintaining good adhesion with the inner peripheral surface of the manhole.
Moreover, there is no risk of the edge being damaged when it is installed in the manhole, and further, water can be drained naturally and the leakage of warm heat from the drain hole can be reliably prevented.
The present invention relates to an inner cover for insulating a manhole.

[0002]

2. Description of the Related Art In a snowy area, snow may be accumulated on a roadway even though snow is removed. This does not cause a big problem when snow accumulates on the roadway at a uniform depth, but the snow accumulated on the iron cover of the manhole is heated by the heat inside the manhole, so it is melted and the surface of that part is melted. A step has occurred, which has been a social problem that causes serious traffic obstacles.
The heat in the manhole is caused by the heat of the sewage flowing in the manhole, for example.

The above-mentioned problems can be solved by preventing heat in the manhole from being transferred to the iron cover of the manhole. Therefore, Japanese Utility Model Application Laid-Open No. 64-14246 discloses an inner lid for heat insulation of a manhole for preventing heat in the manhole from being transferred to an iron lid of the manhole. Hereinafter, the heat insulating inner lid of the manhole is referred to as a conventional inner lid, which will be described with reference to the drawings.

FIG. 5 is a sectional view showing a conventional inner lid, and FIG. 6 is a sectional view.
It is sectional drawing which shows the state which attached the conventional inner lid in the manhole. As shown in FIGS. 5 and 6, the conventional inner lid includes a circular heat insulating plate 1 made of synthetic resin foam.
The heat insulating plate 1 is provided with an insertion hole 1A for connecting the iron cover 3 of the manhole 2 or a wire 4 which serves as a handle of the heat insulating plate 1. The lower end diameter dimension R1 of the heat insulating plate 1 is
The upper end diameter dimension R2 is smaller than the upper end diameter dimension R2, that is, the upper end diameter dimension R2 is slightly larger than the inner diameter dimension of the manhole 2. This is because when the heat insulating plate 1 is fitted into the manhole 2, a pressing force is generated against the inner peripheral surface of the manhole 2 to improve the adhesion between the heat insulating plate 1 and the manhole 2.

According to the conventional inner lid thus constructed, as shown in FIG. 6, the heat insulating plate 1 is pushed into the manhole 2 below the iron lid 3 with a gap therebetween. As a result, it is possible to prevent the heat inside the manhole 2 from being transferred to the iron lid 3, and to prevent the snow accumulated on the iron lid 3 from melting.

[0006]

However, the above-mentioned conventional inner lid has the following problems. The heat insulating plate 1 is forcedly pushed into the manhole 2, and the pressing force is concentrated on the edge of the heat insulating plate 1 having the large-diameter dimension R2 during this pressing, so that the heat insulating plate 1 is easily deformed. When the heat insulating plate 1 is deformed, a gap is generated between the outer peripheral surface of the heat insulating plate 1 and the inner peripheral surface of the manhole 2, and the airtightness is lowered, so that a desired heat insulating effect cannot be obtained. Due to the secular change, the adhesion between the edge of the heat insulating plate 1 and the inner peripheral surface of the manhole 2 decreases, and the desired heat insulating effect cannot be obtained from this point as well. Since the heat insulating plate 1 is made of synthetic resin foam,
When the heat insulating plate 1 is pushed into the manhole 2, the thin edge of the heat insulating plate 1 is easily damaged. Since the heat insulating plate 1 is not provided with a drain hole, the snowmelt water flowing into the manhole 2 from the iron lid 3 is accumulated on the heat insulating plate 1 and is not discharged. The heat insulating plate 1 has a wire 4 for connecting to the iron lid 3 or serving as a handle of the heat insulating plate 1.
Although the insertion hole 1A of the wire 4 is formed, the insertion hole 1A of the wire 4
Small diameter holes do not serve as drainage holes.

Therefore, the object of the present invention is to maintain good adhesion to the inner peripheral surface of the manhole at all times, and as a result, an excellent heat insulating effect can be obtained, and moreover, there is a fear that the edge may be damaged when the manhole is attached. Another object of the present invention is to provide an inner lid for heat insulation of a manhole, which is free from drainage and can reliably prevent leakage of warm heat from the drainage hole.

[0008]

The invention according to claim 1 is
It is composed of a circular heat insulating plate having a water drainage hole, and a tube made of a flexible material attached to the outer peripheral surface of the heat insulating plate, and the heat insulating plate is a manhole through the expanded tube. It is characterized by being closely adhered and retained inside.

According to a second aspect of the invention, a float type seal is attached to the drain hole, and the seal is
It consists of a float that rises due to the buoyancy of water accumulated on the heat insulating plate, and a weight for pressing the float against the water draining hole to close the water draining hole when water is not accumulated on the heat insulating plate. It has a special feature.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a heat insulating inner lid for a manhole according to the present invention will be described with reference to the drawings.

FIG. 1 is an assembled perspective view of the heat insulating inner lid of the present invention, FIG. 2 is a sectional view showing the manner of attaching the heat insulating inner lid to a manhole, and FIG. 3 is the heat insulating inner lid of the present invention. FIG. 4 is a perspective view showing a float type stopper used for the inner lid.
FIG. 4 is a cross-sectional view showing a mounted state of a float type stopper used for the heat insulating inner lid of the present invention.

In FIGS. 1 to 4, 5 is a drainage hole 5.
It is a circular heat insulating plate in which A is formed. The heat insulating plate 5 is made of a synthetic resin foam having a high heat insulating property, such as polyethylene. A semicircular groove 5B into which a tube described later is fitted is formed on the entire outer peripheral surface of the heat insulating plate 5. A concave fitting portion 5C for accommodating the air inlet of the tube is formed at the edge of the heat insulating plate 5. 6
After fitting the tube into the groove 5B, the concave fitting portion 5
It is a cap for closing C. The cap 6 is made of the same material as the heat insulating plate 5.

Reference numeral 7 is a groove 5 formed on the outer peripheral surface of the heat insulating plate 5.
It is a ring-shaped tube made of a highly flexible material, such as rubber, which is fitted into B. Air can be injected into and discharged from the air inlet 7A in the tube 7. The fluid to be injected into the tube 7 may be a liquid such as an antifreezing liquid other than a gas such as air. By injecting such gas or liquid into the tube 7, it is possible to prevent the tube 7 from being frozen on the inner peripheral surface of the manhole 2 and preventing the heat insulating plate 5 from being removed from the manhole 2.

According to the heat-insulating inner lid of the present invention constructed as described above, the heat-insulating plate 5 in which the tube 7 is fitted is inserted into the manhole 2 at a distance from the iron lid 3,
Hold horizontally. Then, air is injected into the tube 7 from the air inlet 7A to inflate the tube 7. As a result, the heat insulating plate 5 is horizontally held in the manhole 2. As a result of the heat insulating plate 5 and the inner peripheral surface of the manhole 2 being in close contact with each other via the flexible tube 7 expanded by air, airtightness is improved. Therefore, since the heat inside the manhole 2 is effectively insulated by the heat insulating plate 5, the iron lid 3
It is possible to surely prevent the snow accumulated on the top from melting.

If a float type seal 9 as shown in FIG. 3 is attached to the drain hole 5A formed in the heat insulating plate 5, the water accumulated on the heat insulating plate 5 can be naturally drained into the manhole 2. . The seal 9 includes a float 10 that rises due to the buoyancy of water accumulated on the heat insulating plate 5 and a water drain hole 5A for removing the float 10 when water is not accumulated on the heat insulating plate 9.
It is composed of a weight 11 for pressing the upper end of the water drainage hole 5A to close the water drainage hole 5A and preventing heat in the manhole 2 from leaking from the water drainage hole 5A. When water accumulates on the heat insulating plate 5, the float 10 rises due to buoyancy. As a result, the drain hole 5A is opened and the water is drained into the manhole 2. On the other hand, when there is no water on the heat insulating plate 5, the float 10 is pressed against the upper end of the drain hole 5A by the load of the weight 11 to close the drain hole 5A. In this way, water is drained naturally and the manhole 2
It is possible to surely prevent the internal heat from leaking.

[0016]

As described above, according to the present invention, since the heat insulating plate is held in the manhole through the flexible tube which is expandable by the fluid, the outer peripheral surface of the heat insulating plate and the manhole are There is no gap between the inner surface and
As a result of improving the airtightness, an excellent heat insulating effect is obtained, and furthermore, the edge of the heat insulating plate is not damaged during mounting.
Further, the float type seal attached to the water draining hole has a useful effect that the water is naturally drained and the leakage of heat and heat in the manhole can be surely prevented.

[Brief description of drawings]

FIG. 1 is an assembled perspective view of an inner lid for heat insulation of the present invention.

FIG. 2 is a cross-sectional view showing how the heat insulating inner lid of the present invention is attached to a manhole.

FIG. 3 is a perspective view showing a float type stopper used for the heat insulating inner lid of the present invention.

FIG. 4 is a cross-sectional view showing a mounted state of a float type stopper used for the heat insulating inner lid of the present invention.

FIG. 5 is a cross-sectional view showing a conventional inner lid.

FIG. 6 is a cross-sectional view showing a state in which a conventional inner lid is attached inside a manhole.

[Explanation of symbols]

1: Insulation plate 1A: insertion hole 2: Manhole 3: Iron lid 4: Wire 5: Insulation plate 5A: Water drainage hole 5B: groove 5C: recessed portion 6: Cap 7: Tube 7A: Air inlet 8: Received frame 9: Seal 10: Float 11: Weight

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Kojima             3-16-9 Kanda, Uchikanda, Chiyoda-ku, Tokyo             Inside this cast iron pipe company F-term (reference) 2D047 BB24

Claims (2)

[Claims] 1. A circular heat insulating plate having a drain hole formed therein, and a tube made of a flexible material attached to the outer peripheral surface of the heat insulating plate, wherein the heat insulating plate is expanded. An inner lid for heat insulation of a manhole, which is adhered and held in the manhole via a tube. 2. A float type seal is attached to the water drain hole, and the seal rises due to the buoyancy of water accumulated on the heat insulating plate and when water is not accumulated on the heat insulating plate. The inner cover for insulating a manhole according to claim 1, further comprising a weight for pressing the float against the water drainage hole to close the water drainage hole.