JP2001173034A - Simplified water storage tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simplified water storage tank of which the cylindrical container can be assembled easily, eliminating a fear of damage from a through- hole, and preventing the stored water inside the tank from overflowing through the upper end of the cylindrical container. SOLUTION: In this tank, a watertight bag body 3 is stored in a cylindrical container 2 assembled by connecting vertically and circumferentially a number of metal wall elements 20 and 21 curved in arc shape, and a light-shielded cover body 4 is put on the upper end opening of the cylindrical container 2. A water feed pipe 9 feeding water to the bag body 3, a water intake pipe 10 taking stored water out of the bag body 3, and an overflow pipe 15 allowing the stored water from overflowing when the level of the stored water exceeds a specified level are disposed through the lower end opening of the cylindrical container 2. No through-hole is formed in the peripheral walls of the container in the range from the lower end to at least 2/3 of the overall height of the cylindrical container 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive relatively large and simple water storage tank suitable for storing rainwater falling on the roof of a house or an agricultural and horticultural house.

[0002]

2. Description of the Related Art Conventionally, groundwater is frequently used for solution cultivation and irrigation of plants, and groundwater is also frequently used for roof watering (watering for cooling) in summer.

However, groundwater may contain a large amount of salt and chemical fertilizers. If such groundwater is used for solution cultivation or irrigation, plants may be adversely affected,
There is a problem that fertilizer design does not go well. However, there is a problem that using tap water increases the cost and is not very good for plants because it contains a large amount of chlorine.

On the other hand, rainwater does not contain salt, chemical fertilizer, chlorine, etc., and is therefore most suitable as water for plant cultivation. Attempts have been made to use it.

As such a tank for storing rainwater, the present applicant has previously proposed a simple assembling tank which is easy to assemble and can be constructed at low cost (Japanese Patent Application No. 11-91580). This simple assembling tank has a volume equal to or slightly larger than the inner volume of the cylindrical container inside a cylindrical container assembled by joining a large number of metal wall elements curved in an arc shape in the vertical and circumferential directions. A watertight bag having an inner volume is accommodated therein, and a lid is attached to an upper end opening of the cylindrical container so that rainwater is stored in the bag.

[0006]

However, in the above-mentioned simple assembling tank, a water supply pipe or an intake pipe is inserted through a through hole formed in the cylindrical container and connected to the bag body. As a result, concentrated stress acts on the through-hole forming portion of the cylindrical container, and there is a possibility that the cylindrical container is broken from that portion. In particular, as the formation position of the through hole is closer to the lower end of the cylindrical container, and as the water level of the stored water becomes higher, the water pressure increases, the concentrated stress acting on the through hole formation portion increases, and the risk of breakage increases. It is impossible to ignore this.

Such a problem can be solved to some extent by reinforcing the through hole forming portion by welding a reinforcing patch or the like, but such a reinforcing operation takes time and effort and increases the cost. It is not preferable.

Further, in the above-mentioned simple assembly tank, the amount of stored water and the level of the stored water cannot be known unless the lid is opened and the inside of the tank is opened. There was also the problem of overflowing.

SUMMARY OF THE INVENTION The present invention has been made to address the above-described problems, and it is a first object of the present invention to provide a simple water storage tank which is free from a possibility that a cylindrical container is broken from a through-hole forming portion or that stored water overflows. It is a second object of the present invention to provide a simple water storage tank in which the level of the stored water can be determined without opening the lid.

[0010]

In order to achieve the first object, a simple water storage tank according to the first aspect of the present invention comprises a plurality of metal wall elements which are curved in an arc shape and which are arranged vertically and circumferentially. Inside the cylindrical container assembled with
A tank containing a water-tight bag having an inner volume equal to or slightly larger than the inner volume of the cylindrical container and having a light-shielding lid attached to an upper end opening of the cylindrical container, A water supply pipe for supplying water to the body and a water intake pipe for taking out stored water from the bag body are provided through the lower end opening of the cylindrical container, and the water is stored when the level of the stored water in the bag body exceeds a predetermined water level. An overflow pipe for overflowing water is provided through the lower end opening of the cylindrical container, and at least two overflow pipes are provided from the lower end of the cylindrical container.
A through hole is not formed in the peripheral wall of the container up to a height of / 3.

In such a simple water storage tank, a water supply pipe, an intake pipe, and an overflow pipe are all disposed through a lower end opening of a cylindrical container, and a container is provided at least 2/3 of the height from the lower end of the cylindrical container. Since the through-hole is not formed in the peripheral wall at all, there is no fear that concentrated stress due to the water pressure of the stored water acts on the through-hole forming portion of the cylindrical container and breaks like a conventional tank. Even if a through hole is formed in the container peripheral wall from the upper end of the cylindrical container to a height of 1/3, concentrated stress due to water pressure acting on the through hole forming portion is small.
Don't worry about destroying.

Further, in the simple water storage tank, when the level of the stored water in the bag body exceeds a predetermined level, the stored water is drained through the overflow pipe, and the level of the stored water is always maintained at a predetermined level or less. There is no fear that the stored water overflows from the upper end opening of the cylindrical container unlike the conventional tank. The cylindrical container is a light-shielding container assembled by joining metal wall elements in the vertical and circumferential directions, and the lid is also light-shielding, so that algae are generated in the stored water when exposed to sunlight. Nothing to do.

[0013] Next, a simplified water storage tank according to a second aspect of the present invention is the water storage tank according to the first aspect, wherein an overflow pipe is connected in the middle of the water supply pipe or the middle of the intake pipe to the outside of the cylindrical container. It is characterized by being erected on

In such a simple water storage tank, there is no need to provide a pipe for directly drawing out the overflow pipe from the bag body to the outside of the cylindrical container through the lower end opening of the cylindrical container. And the number of connection points between the bag body and the pipe is reduced by one, so that the risk of water leakage due to poor connection is reduced.

Next, a simple water storage tank according to a third aspect of the present invention is provided inside a cylindrical container assembled by joining a large number of metal wall elements curved in an arc shape in the vertical and circumferential directions. A tank in which a watertight bag having an inner volume equal to or slightly larger than the inner volume of the cylindrical container is housed, and a light-shielding lid is attached to an upper end opening of the cylindrical container, A water supply pipe for supplying water to the bag body is provided through the cutout portion of the lid body, and an intake pipe for taking out stored water from the bag body, and when a water level of the stored water in the bag body exceeds a predetermined water level. An overflow pipe for overflowing the stored water is provided through a lower end opening of the cylindrical container, and a through hole is not formed in a peripheral wall of the container at a height of at least 2/3 from a lower end of the cylindrical container. It is characterized in that so.

In such a simple water storage tank as well, the intake pipe and the overflow pipe are provided through the lower end opening of the cylindrical container, and the water supply pipe is provided through the cutout portion of the lid, so that the lower end of the cylindrical container can be provided. At least 2 /
Since no through-hole is formed in the container peripheral wall up to the height of 3, concentrated stress due to the water pressure of the stored water acts on the through-hole forming portion of the cylindrical container and breaks as in a conventional tank. Worries are eliminated. And, since the water level of the stored water is kept below a predetermined level by the overflow pipe, there is no fear that the stored water overflows from the upper end opening of the cylindrical container, and light is blocked by the lid or the cylindrical container. Therefore, no algae are generated in the stored water.

Next, a simple water storage tank according to a fourth aspect of the present invention is the water storage tank according to the third aspect, wherein the overflow pipe is connected in the middle of the water intake pipe and is provided outside the cylindrical container. It is characterized by having done.

This simple water storage tank also eliminates the need for piping for drawing out the overflow pipe, and simplifies the piping, thereby improving workability and reducing the number of connection points between the bag and the pipe by one. In addition, concerns about water leakage due to poor connection are reduced.

Next, a simple water storage tank according to a fifth aspect of the present invention for achieving the second object is the water storage tank according to any one of the first to fourth aspects, wherein the bag body is provided outside the cylindrical container. And a water level gauge for indicating the water level of the stored water is provided.

In such a simple water storage tank, the level of the stored water can be known by looking at the water level meter without opening the lid and looking inside the tank.

Next, a simple water storage tank according to a sixth aspect of the present invention is the water storage tank according to the fifth aspect, wherein a narrow band-shaped transparent portion in the pipe length direction is formed on the overflow pipe. It is a feature.

In such a simple water storage tank, since the water level of the stored water is equal to the water level of the overflow pipe, the water level inside the overflow pipe can be determined by observing the water level inside the overflow pipe through a narrow band-shaped transparent portion of the overflow pipe. Since the water level can be immediately known, and it is not necessary to separately provide a special water level gauge, an increase in cost can be prevented.

Next, a simple water storage tank according to a seventh aspect of the present invention is the simple water storage tank according to the sixth aspect, wherein the simple water storage tank has an approximately 2/3 arc-shaped cross-sectional shape covering the transparent portion of the overflow pipe. The cover body is rotatably fitted to the overflow pipe.

In such a simple water storage tank, the transparent body of the overflow pipe is exposed by turning the cover only when checking the water level of the stored water, and at other times, the transparent part is covered with the cover and light is emitted. Since light can be shielded from entering the overflow pipe from the transparent part, it is possible to prevent algae from being generated in the water in the overflow pipe.

Next, in the simple water storage tank according to claim 8 of the present invention, in the water storage tank according to any one of claims 1 to 7, a downspout is connected to a water supply pipe thereof, and filtration is performed in the middle of the downspout. A device is provided.

In such a simple water storage tank, since rainwater flowing down the downspout is filtered by a filtration device to remove dust and the like, clean rainwater can be supplied to and stored in the bag in the cylindrical container. it can.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing a simplified water storage tank according to an embodiment of the present invention, FIG. 2 is a schematic sectional view of the water storage tank, and FIG. 3 (a) is a wall element used for a cylindrical container of the water storage tank. FIG. 3B is a perspective view of a lowermost wall element used in the cylindrical container, FIG. 4 is an enlarged perspective view of an end of the wall element, and FIG. 5 is a circle of a wall element in the cylindrical container. FIG. 6 is an enlarged cross-sectional view of a vertical joining portion of a wall element in the cylindrical container. FIG. 6A is an enlarged sectional view of a joining portion in a vertical direction, and FIG. (b) shows a state after the inside is bent. 7 is an explanatory view showing an attached state of an upper end portion of the bag body, FIG. 8 is an exploded partial perspective view of the overflow pipe and its cover body, and FIG. 9 is a cross-sectional view of the overflow pipe with the cover body fitted outside. (A) shows a state in which the transparent portion of the overflow tube is covered with a cover body, (b)
Shows a state in which the transparent body of the overflow tube is exposed by rotating the cover body.

1 and 2, reference numeral 1 denotes a doughnut-shaped concrete foundation, on which a cylindrical container 2 is installed. A watertight bag 3 is accommodated inside the cylindrical container 2, and a lid 4 is provided.
Is detachably attached to the upper end opening of the cylindrical container 2.

The cylindrical container 2 is assembled by joining the metal wall elements 20 curved in an arc shape shown in FIG. 3A in the vertical direction and in the circumferential direction. FIG. 3 (b) shows the bottom of the container 2.
The wall element 21 shown in FIG. Each of these wall elements 20 and 21 is manufactured by bending a metal plate such as a zinc steel plate, an aluminum-plated steel plate, or a stainless steel plate having a thickness of about 0.4 to 1 mm which is easily bent at a construction site or in a factory. It was done.

That is, the wall element 20 shown in FIG.
Is formed by bending the upper and lower ends of a metal plate curved into an arc shape obtained by dividing the circumference into three parts at right angles outwardly, thereby forming an upper end flange portion 20.
a and the lower end flange portion 20b, respectively,
The distal ends of the flange portions 20a and 20b are further bent at a right angle downward, and a short hanging edge 20c having a short vertical dimension is provided at the distal end of the upper flange portion 20a, and a hanging edge 20d having a vertical dimension longer than the vertical edge 20c is provided at the lower flange portion. As shown in FIGS. 3A and 4, a U-shaped folded portion 20 e is formed at both left and right ends of the wall element 20 so as to be folded outward in a U-shape. hand,
A joining member 5 having a substantially C-shaped cross section is attached to the U-shaped folded portion 20e.
Are engaged with each other.

The specific dimensions of the wall element 20 are not particularly limited, and may be appropriately determined in consideration of the size of the cylindrical container 2 to be assembled and the weight of the wall element. Container 2 has a diameter of 2.5
Since a size of about 8.0 m is appropriate, the radius of curvature of the wall element 20 is desirably set to about 1.25 to 4.0 m, and the vertical dimension is set to about 20 to 50 cm. desirable.

The wall element 21 shown in FIG. 3B, which is used at the lowermost stage of the cylindrical container 2, is formed by bending the upper end flange portion 21a and the wall element 21 in the same manner as the wall element 20 shown in FIG. A short hanging edge 21 with a short top and bottom dimension
c, a wide lower end flange portion 21b, and a U-shaped folded portion 21e at both left and right ends, but a drooping edge is not formed at the tip of the lower end flange portion 21b. Is different from the wall element 20 of FIG.

As shown in FIG. 6 (a), the vertical joining of the wall element 20 is performed by connecting the lower end flange portion 20b of the upper wall element 20 to the upper end flange of the lower wall element 20. 6B, the lower portion of the hanging edge 20d of the lower end flange portion 20b is folded upward so that the hanging edge 20c of the upper end flange portion 20a is embraced, and further, as shown in FIG. It is performed by bending and crimping. The wall element 20 and the lowermost wall element 2
1 is also vertically joined in the same manner as described above.

As shown in FIG. 5, the wall elements 20 are joined in the circumferential direction by connecting the wall elements 20 with each other in the circumferential direction.
0e, the edge 5 of the joining member 5 having a substantially C-shaped cross section described above.
a and 5a are engaged to caulk the engaging portion, or the engaging portion is adhered and fixed with an adhesive. Then, joining of the lowermost wall element 21 in the circumferential direction is performed in the same manner.

As described above, this cylindrical container 2
While the wall elements 20 and 21 are not welded to each other in a watertight manner, the respective hanging edges 20c and 20d of the upper flange portion 20a and the lower flange portion 20b are bent, and
The wall element 2 is formed by a simple operation of simply connecting and fixing the U-shaped folded portions 20e, 20e using the joining member 5.
0 and 21 are joined in the vertical direction and the circumferential direction, so that they can be assembled in a shorter time and at a lower cost than in the case of welding. Moreover, the wall elements 20, 21
Is curved in an arc shape divided into three, so that it can be statically settled and held in the same shape as the three-link mechanism, and can maintain the shape of the cylindrical container. It is strong enough to withstand water pressure.

As shown in FIGS. 1 and 2, the cylindrical container 2 is mounted on a concrete foundation 1 by fixing the lower end flange portion 21 b of the lowermost wall element 21 at several places with anchor bolts 6. Therefore, there is no fear that the cylindrical container 2 will fall even if a typhoon comes or an earthquake occurs.

The lid 4 attached to the upper end opening of the cylindrical container 2 is made of a light-shielding material, and is stored in the bag 3 inside the container 2 because it does not transmit light. Algae can be prevented from being generated in the storage water W. Preferred specific examples of such a lid 4 include:
A lid in the form of a jin-kasa made by stretching a flexible, lightweight and tough opaque light-shielding covering material 4a such as canvas on a lid frame (frame) can be given.

The bag 3 accommodated in the cylindrical container 2 is
A cylindrical synthetic resin film having a diameter substantially equal to the inner diameter of the cylindrical container 2 is water-tightly fused and integrated with a peripheral portion of a circular bottom sheet made of synthetic resin or synthetic rubber. In addition, it has an internal volume equal to or slightly larger than the internal volume of the cylindrical container. Therefore, even when the bag 3 is full with the stored water W, there is no gap between the bag 3 and the cylindrical container 2. Since the water pressure is applied to the cylindrical container 2, there is no fear that the bag body 3 will burst due to the water pressure.

The cylindrical synthetic resin film constituting the bag 3 is made of polyethylene having high flexibility and tear strength.
A tubular inflation film (thickness of about 0.1 to 0.3 mm) of polypropylene, polyvinyl chloride, nylon, or the like, an EVA sheet, a laminated film of various resins, a meshed film for reinforcement, and the like are preferably used. You. These films may be used in a state where two films are stacked, and when such two films are stacked, even if one film is torn, the other film can prevent water leakage. Further, as the circular bottom sheet constituting the bag body 3, a sheet having a thickness of about 0.5 to 1.5 mm made of the same synthetic resin as the above synthetic resin film or a synthetic rubber such as EPDM having good weather resistance is used. 0.5-1.5mm thickness
Degree sheets are preferably used.

At the upper end of the bag 3, eyelets (not shown) are provided at intervals of 50 to 100 cm, and a string is passed through the eyelets and fixed to the peripheral wall of the cylindrical container 2 or, as shown in FIG. The upper end of the bag body 3 is wound around the flange portion 20a at the upper end of the mold container 2, and the packer 31 is fitted thereon by fitting the packer 31 thereon. As shown in FIG. 2, the bag body 3 is placed on a foam plate 7 laid on the bottom of the tank and housed inside the cylindrical container 2. In FIG. 2, reference numeral 8 denotes a sand layer for leveling the foam board 7.

As shown in FIG. 2, a water supply pipe 9 and a water intake pipe 10 are connected to the circular bottom sheet of the bag body 3 in a watertight manner, and both the water supply pipe 9 and the water intake pipe 10 are The pipe extends through the foam plate 7 and the sand layer 8 at the bottom of the tank, and is drawn out of the container 2 through the lower end opening of the cylindrical container 2. Therefore, no through hole is formed in the cylindrical container 2 for passing a water supply pipe or an intake pipe. Thus, the cylindrical container 2
If there is no through hole in the container, even if the water pressure of the stored water W in the bag body 3 is applied to the inner surface of the container, concentrated stress cannot be applied to the portion where the through hole is formed as in the related art. The fear of inviting is resolved.

The part where the through-hole should not be formed is the container peripheral wall from the lower end of the cylindrical container 2 on which high water pressure acts to at least 2/3 of the height,
Since a large water pressure does not act on the peripheral wall of the container above, even if the through hole is formed, the cylindrical container 2 will not be broken.

As shown in FIG. 2, the water supply pipe 9 is connected to a downspout 11, and a filtration device 12 is attached in the middle of the downspout 11. Therefore, rainwater that has fallen on the roof 13 of the house flows down the downspout 11 from the eaves gutter 14 and is filtered by the filtering device 12 to remove dust and the like. Therefore, only clean rainwater is supplied from the water supply pipe 9 into the cylindrical container 2. And stored in the bag 3.

In the middle of the water supply pipe 9, the upper end 15
a is connected to an overflow pipe 15 bent in an inverted U-shape.
a stands up to the outside of the cylindrical container 2 so as to reach near the upper end of the cylindrical container 2. Therefore, the bag 3
When the water level of the stored water W exceeds the upper end 15 a of the overflow pipe 15, the stored water W naturally flows out from the tip opening 15 b of the overflow pipe 15, and the water level of the stored water W is higher than the upper end 15 a of the overflow pipe 15. When lowered, the outflow of the stored water W stops. Therefore, the water level of the stored water W is always the upper end 15a of the overflow pipe 15.
Since the water level is maintained at the following level, the stored water W does not overflow from the upper end opening of the cylindrical container 2.

The overflow pipe 15 may be connected to another pipe drawn from the circular bottom sheet of the bag body 3 through the lower end opening of the cylindrical container 2, and may be erected, but as in this embodiment, the supply pipe 9 is provided. When the overflow pipe 15 is connected in the middle of the pipe, the number of pipes drawn out from the bag body 3 through the lower end opening of the cylindrical container 2 is reduced by one, so that the pipe is simplified and the workability is reduced by that much. And the number of connection points between the bag and the pipe is reduced by one, so that there is less concern about water leakage due to poor connection.

As shown in FIG. 8, the overflow pipe 15 is configured to also serve as a water level gauge by forming a narrow strip-shaped transparent portion 15c in the pipe length direction except for an inverted U-shaped upper end 15a. ing. And this transparent part 15
cover 1 having a substantially 2/3 arc-shaped cross-sectional shape that covers c.
5 d is rotatably fitted to the overflow pipe 15.

Therefore, by turning the cover body 15d, as shown in FIG.
If the water level of the stored water W can be immediately known by exposing the water level of the storage water W by exposing the water 5c and turning the cover body 15d back to cover the transparent part 15c as shown in FIG. Since the water does not enter the overflow pipe 15 from the portion 15c, the generation of algae in the water in the overflow pipe 15 can be prevented.

Although a water level gauge may be separately provided, if the overflow pipe 15 is used in combination with the water level gauge as in this embodiment, a dedicated water level gauge is not required.
There is an advantage that an increase in cost can be prevented.

On the other hand, a water faucet post 16 is connected to the water intake pipe 10, and the water faucet post 16 is erected from the foundation 1. Therefore, when the faucet 16a of the faucet column 16 is opened,
Since the stored water W stored in the bag body 3 inside the cylindrical container 2 can be taken, the stored water W can be effectively used for watering garden trees, watering the roof, and the like, thereby saving tap water.

FIG. 10 is a perspective view of a simple water storage tank according to another embodiment of the present invention, and FIG. 11 is a schematic sectional view of the water storage tank.

In this simple water storage tank, the water supply pipe 9 is inserted into the bag 3 inside the cylindrical container 2 from above through the notch 4a formed at the edge of the lid 4, and the water supply pipe 9 is inserted into the cylindrical shape. The container 2 is mounted and fixed by a mounting piece 22 protruding inward from an opening edge of the upper end of the container 2. Then, the overflow pipe 15 also serving as the water level gauge is connected in the middle of the water intake pipe 10 piped so as to be drawn out through the lower end opening of the cylindrical container 2, and the upper end 15 a reaches near the upper end of the cylindrical container 2. The overflow pipe 15 is erected as described above.

The other structure of this simple water storage tank is the same as that of the above-mentioned simple water storage tank. Therefore, in FIGS. 10 and 11, the same members are denoted by the same reference numerals, and description thereof will be omitted.

In such a simple water storage tank as well, since no through hole is formed in the cylindrical container 2, there is no fear that the cylindrical container is broken by the concentrated stress acting on the portion where the through hole is formed. Overflow pipe 15
In addition to knowing the water level of the stored water W, the stored water W can be prevented from overflowing from the upper end opening of the cylindrical container 2.

When the water supply pipe 9 is inserted into the bag 3 inside the cylindrical container 2 from above through the notch 4a of the lid 4 like this simple water storage tank, the tip of the water supply pipe 9 is inserted into the bag 3. There is no need to connect in a watertight manner, so that piping work is easier than in the case of piping through the lower end opening of the cylindrical container 2, and there is an advantage that there is no danger of water leakage from the connection point between the water supply pipe and the bag body. . The mounting piece 22 for mounting and fixing the water supply pipe 9 also serves as a light-shielding plate that blocks light entering from the cutout portion of the lid 4, so that the stored water W
No algae are generated.

Although the simplified water storage tank of the present invention has been described with reference to two representative embodiments, the present invention is not limited to only these embodiments, and various design changes are allowed. What you get.

[0057]

According to the simple water storage tank of the present invention, the assembling work of the cylindrical container can be easily performed at a low cost, and the water supply pipe, the intake pipe and the overflow pipe are all arranged through the lower end opening of the cylindrical container. Or by disposing a water supply pipe through a notch in the lid and arranging an intake pipe and an overflow pipe through a lower end opening of the cylindrical container, so that at least two
Since the through-hole is not formed in the container peripheral wall up to the height of / 3, concentrated stress due to the water pressure of the stored water acts on the through-hole forming portion of the cylindrical container and breaks as in a conventional tank. It has a remarkable effect of eliminating concerns. And since the water level of the stored water is always kept below the predetermined water level by the overflow pipe, there is no fear that the stored water overflows from the upper end opening of the cylindrical container unlike a conventional tank, and in particular, it also serves as a water level gauge. A simple water storage tank equipped with an overflow pipe allows the level of the stored water to be immediately known without opening the lid, and because the light is blocked by the light-shielding lid and the cylindrical container, the algae can be stored. There are many effects such as no occurrence of

[Brief description of the drawings]

FIG. 1 is a perspective view showing a simple water storage tank according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of the water storage tank.

3 (a) is a perspective view of a wall element used for a cylindrical container of the water storage tank, and FIG. 3 (b) is a perspective view of a lowermost wall element used for the cylindrical container.

FIG. 4 is an enlarged perspective view of an end of the wall element.

FIG. 5 is an enlarged sectional view of a circumferentially joined portion of a wall element in the cylindrical container.

6A and 6B are enlarged cross-sectional views of a vertical joining portion of a wall element in the cylindrical container, wherein FIG. 6A is a state before being bent inward, and FIG. This shows a later state.

FIG. 7 is an explanatory view showing an attached state of an upper end portion of the bag body.

FIG. 8 is an exploded partial perspective view of an overflow pipe and a cover body thereof.

FIGS. 9A and 9B are cross-sectional views of the overflow pipe with the cover body externally fitted thereto, wherein FIG. 9A shows a state in which the transparent portion of the overflow pipe is covered with the cover body, and FIG. 3 shows a state in which the transparent portion is exposed.

FIG. 10 is a perspective view showing a simplified water storage tank according to another embodiment of the present invention.

FIG. 11 is a schematic sectional view of the water storage tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concrete foundation 2 Cylindrical container 20, 21 Wall element 3 Bag 4 Lid 4a Notch 9 Water supply pipe 10 Intake pipe 11 Downspout 12 Filtration device 15 Overflow pipe 15c Narrow band transparent part 15d Cover body

Claims (8)

[Claims] 1. Inside a cylindrical container assembled by joining a large number of metal wall elements curved in an arc shape in a vertical direction and a circumferential direction, a content equal to or slightly larger than the inner volume of the cylindrical container. A tank in which a water-tight bag having a volume is accommodated, and a light-shielding lid is attached to an upper end opening of the cylindrical container, wherein a water supply pipe for supplying water to the bag and the bag are provided. An intake pipe for taking out stored water is provided through a lower end opening of the cylindrical container, and an overflow pipe for overflowing the stored water when the level of the stored water in the bag exceeds a predetermined level is provided at the lower end of the cylindrical container. A simple water storage tank disposed through an opening, wherein a through hole is not formed in a peripheral wall of the container from a lower end of the cylindrical container to a height of at least 2/3. . 2. The simple water storage tank according to claim 1, wherein the overflow pipe is connected to the middle of the water supply pipe or the middle of the water intake pipe and is provided upright outside the cylindrical container. 3. The inside of a cylindrical container assembled by joining a large number of metal wall elements curved in an arc shape in the vertical direction and the circumferential direction, the contents being equal to or slightly larger than the internal volume of the cylindrical container. A tank in which a water-tight bag having a volume is accommodated and a light-shielding lid is attached to an upper end opening of the cylindrical container, and a water supply pipe for supplying water to the bag is provided with a water supply pipe of the lid. The cylindrical container includes a water intake pipe provided through the notch portion, for taking out stored water from the bag body, and an overflow pipe for overflowing the stored water when the level of the stored water in the bag body exceeds a predetermined water level. A simple water storage tank, which is provided through a lower end opening of the container and has no through hole formed in a peripheral wall of the container from the lower end of the cylindrical container to a height of at least 2/3. 4. The simple water storage tank according to claim 3, wherein the overflow pipe is connected in the middle of the water intake pipe and is provided upright outside the cylindrical container. 5. The simple water storage tank according to claim 1, further comprising a water level meter for indicating a water level of the stored water in the bag inside the cylindrical container. 6. A simple water storage tank according to claim 5, wherein a narrow band-shaped transparent portion in the pipe length direction is formed in said overflow pipe to form a water level gauge. 7. An approximately 2 covering a transparent portion of said overflow tube.
The simple water storage tank according to claim 6, wherein an opaque cover body having a / 3 arc-shaped cross section is rotatably fitted to the overflow pipe. 8. The simple water storage tank according to claim 1, wherein a vertical gutter is connected to the water supply pipe, and a filtration device is provided in the middle of the vertical gutter.