JPH0948491A - Double-shell tank, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency in the entire work of manufacturing by a method wherein both ends of an inner-shell tank are formed as closing parts in flatness (in the form of end plate) without requiring processing for forming spherical surface or the like. SOLUTION: Prior to forming an outer-shell tank 10 at the outside of an inner-shell tank 2, resin films are stuck to the circumferential surface of a cylindrical part 3 and the outer peripheral parts on end plates 4 of the inner- shell tank 2, and the outer-shell tank 10 is made up with warped plates 12A joined together, with ring bodies 11 joined to the circumferential drum part 12, and with the ring bodies 11 joined to flat plates 13 respectively with joining parts 12C, 13B or the like. The end plates 4 for closing both ends of the cylindrical part 3 of the inner-shell tank 2 are formed in flat disk shapes while both ends of the outer-shell tank 10 are formed likewise of the flat plates 13. Therefore, processing for forming spherical surface specially required in a conventional method becomes unnecessary, and works in manufacture and assemblage of the inner-shell tank 2 and the outer tank 10 can be simplified to a great extent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double shell tank preferably used as an underground tank buried underground such as a gasoline filling station and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, in a gasoline filling station or the like,
Multiple underground tanks (oil storage tanks) formed as a cylindrical closed container made of a rigid material such as iron are buried underground in the gas station, and oil liquids such as gasoline, light oil, and kerosene are individually stored in these underground tanks. I try to store it.

By the way, since oil liquid such as gasoline is a dangerous substance, it is obliged to take special measures against leakage of oil liquid. For example, a concrete frame or the like is provided around the underground tank. The so-called concrete pit type which is surrounded by is adopted.

However, in this concrete pit type,
Prior to burying an underground tank (oil storage tank) underground in a gas station, etc., it is necessary to assemble a concrete frame, etc., into a sturdy structure, which is a drawback that a great deal of labor and time are required to bury the underground tank. is there. Therefore, for example, JP-A-59-142982 and JP-A-6-34518.
In Japanese Patent Laid-Open No. 3 and the like, it is proposed that the underground tank has a double shell structure in order to simplify the burying work of the underground tank.

That is, an underground tank having a double shell structure is formed by a steel inner shell tank containing an oil liquid such as gasoline inside and a fiber reinforced resin material (FRP) and the like. It consists of an outer shell tank surrounded by
A detection space for detecting leakage of the oil liquid is defined between the outer shell tank and the inner shell tank with a small gap size of, for example, about 0.1 mm. In this case, the inner shell tank is composed of a cylindrical portion formed in a cylindrical shape and a pair of closing portions (end plate portions) for closing both end sides of the cylindrical portion, and each closing portion is a convex spherical surface. It has a shape to increase the strength of the inner shell tank.

Further, the inner shell tank or the outer shell tank is provided with a leak detection pipe whose lower end communicates with the detection space and whose upper end projects upward to the outside of the tank, and the leak detection pipe has a leak detection pipe. When a liquid is leaked from the inner shell tank into the detection space or groundwater or the like enters (leaks) into the detection space from the outside of the outer shell tank, this is detected by the leak detector. This is detected early to prevent oil liquid (dangerous substances) from leaking out around the underground tanks at gas stations.

On the other hand, a connection box for signal lines is provided on the upper end side of the leak detection tube via a tubular body with a flange, and the inside of the leak detection tube is located inside the detection space at the bottom side of the connection box. It has a structure that seals against the outside. The junction box is provided with an inspection port for airtightness inspection.When performing an airtightness inspection of the underground tank, this inspection port is connected to an external pressure air source, etc., and air is introduced into the leak detection pipe (detection space). It is inspected whether or not it is sealed and can secure the rise of pressure.

[0008]

By the way, in the above-mentioned prior art, an inner shell tank having a double shell structure together with an outer shell tank is provided with a tubular portion formed in a cylindrical shape and both end sides of the tubular portion. Since each of the closed portions is formed into a convex spherical shape, it is necessary to form each closed portion by spherical processing or the like. There is a problem that it takes time and effort to manufacture the (end plate part), the manufacturing cost increases, and the workability during manufacturing deteriorates.

Also, regarding the outer shell tank, it is necessary to form the end plate portions on both ends of the outer shell tank in a convex spherical shape so as to correspond to the closed portions (end plate portions) of the inner shell tank. When the side is formed, for example, a resin film (thin film) is covered on the closed portion (end plate portion) of the inner shell tank,
The fiber reinforced resin material is applied over this to solidify it so that it is molded so that the end plate part side of the outer shell tank is molded, and then this molded product (end plate part side of the outer shell tank) is molded into the inner shell tank. It is configured to form a detection space for leak detection between the end plate part of the outer shell tank and the end cover part (end plate part) of the inner shell tank by being attached to the closed part (end plate part).

As a result, even when molding the end plate portion side of the outer shell tank, it takes extra time and labor to form the convex spherical surface shape, the manufacturing cost is significantly increased, and each convex spherical surface shape is formed. There is a problem that it is difficult to form the detection space between the end plate portions of the formed outer shell tank and the inner shell tank, and the gap size of the detection space may increase to several mm (millimeters).

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention can eliminate the need for spherical processing by forming both ends of the inner shell tank as flat plate-shaped closed portions (end plate portions). A double-shell tank and a manufacturing method thereof, which can surely improve the overall workability including the outer-shell tank at the time of manufacturing (manufacturing), and can greatly simplify the outer-shell tank manufacturing and assembling work. Is intended to provide.

[0012]

In order to solve the above-mentioned problems, in the invention described in claim 1, the liquid is made to flow by a tubular portion and flat plate-shaped closing portions provided on both end sides of the tubular portion. An inner shell tank formed as a container for accommodating, and an outer shell tank formed of a fiber reinforced resin material and surrounding the inner shell tank from the outside so as to form a double shell structure leaving the upper side of the inner shell tank. And a space for leak detection defined between the outer shell tank and the inner shell tank.

In this case, in the invention as set forth in claim 2, in order to form a space between the inner shell tank and the outer shell tank, at least the vicinity of the boundary portion between the tubular portion and each closed portion is provided. A space forming member that covers from the outside is provided, and the outer shell tank is formed so that the portion corresponding to the upper side of the inner shell tank becomes a cutout portion so that the diameter can be reduced and expanded. A C-shaped ring body provided near the boundary with the closed part via the space forming material, and the space forming on the outer peripheral side of the cylindrical part of the inner shell tank. A curved plate portion joined on the material, and a flat plate portion disposed on the closed portion of the inner shell tank and having an outer peripheral side joined to the inner peripheral side of the ring body on the space forming material. .

Further, in the invention according to claim 3, an inner shell tank formed as a container for containing a liquid by a tubular portion and flat plate-shaped closed portions provided at both ends of the tubular portion, and a fiber. An outer shell tank formed of a reinforced resin material and surrounding the inner shell tank from the outside so as to form a double shell structure leaving the upper side of the inner shell tank, and the outer shell tank and the inner shell tank. A method for manufacturing a double-shell tank comprising a space for leakage detection defined between the inner shell tank and the outer shell tank for forming the space between the inner shell tank and the outer shell tank. The step of applying a release agent to the outer surface of the inner shell tank except the upper side, and the outer shell tank by applying a fiber reinforced resin material to the outer surface of the inner shell tank through the release agent. And a molding step.

[0015]

With the above construction, in the invention described in claim 1,
Since each closed portion located on both ends of the tubular portion of the inner shell tank is formed in a flat plate shape, the both end sides of the outer shell tank can be formed in a flat plate shape in the same manner as in the prior art. Since it is not necessary to perform spherical surface processing or the like, the gap size of the space formed between the outer shell tank and the inner shell tank can be reduced substantially evenly throughout.

In this case, according to the second aspect of the present invention, prior to disposing the ring body, the curved plate portion and the flat plate portion constituting the outer shell tank outside the inner shell tank, the inner shell tank and the outer shell tank are provided. A space forming material for forming a space portion between the shell tank and the shell tank is provided so as to cover at least a boundary portion between the tubular portion of the inner shell tank and each closed portion from the outside, and the space forming material is provided on the space forming material. While joining the curved plate part to the outer peripheral side of the ring body,
Since the flat plate portion is bonded to the inner peripheral side of the ring body, even if these bonding portions are bonded (bonded) to the space forming material, they are bonded (bonded) to the outer surface of the inner shell tank. The space forming member can surely prevent such a state, and a space portion for leak detection can be easily formed between the inner shell tank and the outer shell tank (ring body, curved plate portion and flat plate portion).

Further, since the ring body of the outer shell tank has a C shape as a whole, and the portion corresponding to the upper side of the inner shell tank is formed as a notch so that the diameter can be reduced and expanded. The ring body can be easily attached near the boundary portion between the tubular portion and the closed portion of the inner shell tank via the notch portion, and the curved plate portion and the flat plate are provided by the C-shaped ring body which covers the boundary portion. It is possible to join the parts with high strength in a stable state.

Further, in the invention according to claim 3, after the inner shell tank is manufactured as the container for containing the liquid from the cylindrical portion and the flat plate-shaped closed portions provided at both ends thereof, the inner shell tank is manufactured. Since a mold release agent is applied to the outer surface of the inner shell tank except for the upper side, the outer shell tank is formed by applying a fiber reinforced resin material to the outer surface of the inner shell tank from above. The release agent applied to the outer surface of the inner shell tank can prevent the fiber reinforced resin material for the outer shell tank from adhering to the outer surface of the inner shell tank, and thus the outer shell tank and the inner shell tank A space for leak detection can be easily formed between the two.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a case where a double shell tank according to an embodiment of the present invention is applied to an underground tank of a gas station will be described with reference to FIGS. 1 to 9.

1 to 5 show the first embodiment of the present invention.

In the figure, reference numeral 1 denotes an oil storage tank as an underground tank (double-shell tank) which is buried underground in a gas filling station. The oil storage tank 1 contains an oil liquid F such as gasoline therein and stores it therein. The inner shell tank 2 forming the main body and an outer shell tank 10 described later are formed as a double shell structure tank. The inner shell tank 2 of the oil storage tank 1 is formed by welding (making) a plurality of plate materials made of high-rigidity material such as steel, as shown in FIG. 4 and FIG. Formed as a container.

Here, the inner shell tank 2 has, for example, an inner diameter of 1 to 1.
About 2.5 m (meter), axial length 6-10 m
It is composed of a cylindrical portion 3 as a cylindrical portion having a certain degree, and end plate portions 4 and 4 as flat plate (disc) closed portions which are closed at both axial ends of the cylindrical portion 3. On the inner surface of the portion 4, as shown in FIG. 3, a reinforcing disc 5 is formed in order of decreasing diameter.
A and 5B are joined by means such as welding. The reinforcing discs 5A and 5B reinforce the end plate portion 4 formed in a flat plate shape from the inner side surface thereof, and the oil liquid F stored in the inner shell tank 2
The withstand pressure strength of the end plate portion 4 with respect to the like is increased.

The cylindrical portion 3 of the inner shell tank 2 is formed by axially joining (welding), for example, three cylindrical bodies 3A, 3A, ... Each end plate portion 4 is formed and is joined to both ends of the cylindrical portion 3 (cylindrical body 3A) by annular welding portions 6 and 6 formed by fillet welding or the like as shown in FIG. And the oil storage tank 1
Is supplied (supplemented) with an oil liquid F such as gasoline into the inner shell tank 2 through an oiling pipe 7 and a tank truck described later,
This oil liquid F is stored in the inner shell tank 2.

Reference numeral 7 denotes an oil injection pipe integrally provided on the upper end side of the cylindrical portion 3 of the inner shell tank 2, and 8 denotes an oil absorption pipe provided on the upper end side of the cylindrical portion 3 similarly to the oil injection pipe 7. 8 and the oiling pipe 7 project upward from the upper end of the inner shell tank 2 and
An oiling hose such as the tank truck is detachably connected to the tip end side of the. The tip end of the oil absorption pipe 8 is connected to a weighing machine (not shown) or the like at a gas station, and when the vehicle is filled with an oil liquid F such as gasoline, a pump (not shown) attached to the weighing machine is used. The oil liquid F is sucked up from the inside of the inner shell tank 2 via the above.

Reference numeral 9 denotes a leak detection pipe provided vertically penetrating the inner shell tank 2. The leak detection pipe 9 is formed by a metal pipe made of steel or the like, and the lower end side thereof is a cylindrical portion 3.
And a communication portion 9A which will be described later. Further, the upper end side of the leak detection pipe 9 projects upward from the inner shell tank 2, and a connection flange 9B for a leak detector (not shown) is integrally provided on the tip end side thereof. And
The inside of the leak detection pipe 9 is only communicated with the detection space 15, and the inside of the inner shell tank 2 is completely shut off, and whether or not liquid has leaked in the detection space 15 can be accurately determined by the leak detector. It is configured to be detected by.

Reference numeral 10 denotes an outer shell tank disposed on the outer surface of the inner shell tank 2 except for the upper side 2A of the inner shell tank 2. The outer shell tank 10 is made of, for example, glass fiber made of epoxy resin or the like. The impregnated fiber reinforced resin material (FRP) is formed as a container corresponding to the outer shape of the inner shell tank 2, and the inner shell tank 2 except for the upper side 2A of the inner shell tank 2 as shown in FIG. The cylindrical portion 3 and each end plate portion 4 are surrounded from the outside.

Here, the outer shell tank 10 is shown in FIGS.
As shown in FIG. 5, the portion corresponding to the upper side of the inner shell tank 2 is formed as a cutout portion 11A so as to be capable of contracting and expanding in diameter, and the boundary portion between the cylindrical portion 3 of the inner shell tank 2 and each end plate portion 4 (welding). A pair of left and right ring bodies 11 and 11 which are fitted onto a portion (in the vicinity of the portion 6) via a resin film 14 which will be described later, and the ring bodies disposed on the outer peripheral side of the cylindrical portion 3 of the inner shell tank 2. Outer part 1 of 11
The peripheral body portion 12 as a curved plate portion joined on each resin film 14 to the 1B side, and the outer peripheral side provided on each end plate portion 4 of the inner shell tank 2 is the inner peripheral side of the inner extending portion 11C of each ring body 11. It is composed of a flat plate portion 13 as an end plate portion joined on each resin film 14.

In this case, each ring body 1 of the outer shell tank 10
Reference numeral 1 denotes a C-shaped ring made of a fiber reinforced resin material, the outer peripheral side of which serves as an outer extending portion 11B and has a length about the thickness of the end plate portion 4 (see FIG. 2) in the axial direction of the inner shell tank 2 or the like. The inner diameter dimension is set to be slightly smaller than the outer diameter dimension of the end plate portion 4.

The inner extending portion 11C of each ring body 11 is radially inward from the base end side of the outer extending portion 11B, for example, 2 to 3.
It extends with a protruding dimension of about cm (centimeter),
Except for the cutout portion 11A, the whole is formed as an annular ring. Then, as shown by the arrows in FIG. 5, each ring body 11 is fitted to the outer peripheral side of each end plate portion 4 of the inner shell tank 2 from the outside in the radial direction via the notch portion 11A, and the elasticity of the ring body 11 is improved. Thus, the end plate portion 4 is held in a retaining state.

On the other hand, the peripheral body portion 12 of the outer shell tank 10 is composed of, for example, three curved plates 12A, 12A, ... Each of the curved plates 12A is a plate-shaped sheet made of a fiber reinforced resin material (FRP). The shell tank 2 is formed so as to be curved in a roll shape substantially corresponding to each cylinder 3A and its width dimension substantially corresponds to the length dimension of each cylinder 3A, and the upper end side of the ring body 11 is formed. It is a groove portion 12B corresponding to the cutout portion 11A.

Then, these curved plates 12A are provided in each cylindrical body 3
It is fitted on the outer peripheral side of A from each groove portion 12B side, and thereafter, the end portion of each curved plate 12A becomes each joint portion 12C shown in FIG. The peripheral body portion 12 of the outer shell tank 10 is formed by being joined to each other by means.

Further, the flat plate portion 13 of the outer shell tank 10 is
By cutting a plate-shaped sheet made of a fiber reinforced resin material (FRP) into a substantially disc shape, the inner extending portion 1 of the ring body 11 is cut.
It is formed with an outer diameter dimension substantially corresponding to the inner diameter of 1C, and a linear cutout 13A corresponding to the cutout 11A of the ring body 11 is provided on the upper end side thereof. Then, each flat plate portion 13 is arranged so as to be attached to each end plate portion 4 of the inner shell tank 2 on the radially inner side of each ring body 11, and the outer peripheral side thereof is formed into a ring-shaped joint portion 13B. It is joined to the inner peripheral side of the inner extending portion 11C of the ring body 11 on the film 14 using a means such as a hand layup method.

Reference numerals 14, 14, ... Denote resin films as space forming materials for forming the detection space 15 between the inner shell tank 2 and the outer shell tank 10.
Is formed as a strip-shaped film (thin film) made of a resin material having sufficiently high durability and heat resistance, like the film for wrapping food and tableware, and the width dimension thereof The width dimension is sufficient to cover the welded portion 3B between the bodies 3A.

As shown in FIG. 5 etc., each resin film 14 has a cylindrical body 3A with the upper side 2A of the inner shell tank 2 remaining.
The welded portion 3B between them, the welded portion 6 between the cylindrical portion 3 and each end plate portion 4, and the outer peripheral side portion of each end plate portion 4 corresponding to the joint portion 13B are attached so as to be extended, and the outer shell tank is attached. It is prevented that the respective joint portions 12C, 13B and the like of 10 are adhered (fixed) to the outer surface of the inner shell tank 2.

Reference numeral 15 denotes a detection space which is defined between the inner shell tank 2 and the outer shell tank 10 and serves as a space for leak detection. The detection space 15 is formed between the outer shell tank 10 and the inner shell. The tank 2 is surrounded by a minute gap of, for example, about 0.1 mm. In addition, in the detection space 15, a space 15A is formed between the cylindrical portion 3 (each cylindrical body 3A) of the inner shell tank 2 and the peripheral body portion 12 (each curved plate 12A) of the outer shell tank 10, and the end plate portion 4 is formed. A gap portion 15B is formed between the flat plate portion 13 and the gap portions 15A and 15B are communicated with each other at the positions of the resin films 14.

The inner shell tank 2 or the outer shell tank 1
The oil liquid F in the inner shell tank 2 is detected in the detection space 15 (voids 15A, 15B) due to damage, cracks, etc. occurring at any of the positions 0.
These liquids (oil liquid F, groundwater or rainwater) are detected when they leak into the interior or when groundwater, rainwater, etc. enter the detection space 15 (voids 15A, 15B) from the outside of the outer shell tank 10. The liquid is accumulated evenly in the space 15 as a whole, and the leak detector can detect the leak of the liquid at an early stage on the joint portion 9A side of the leak detecting tube 9 shown in FIG.

The oil storage tank 1 as a double-shell tank according to this embodiment has the above-described structure. Next, a method for manufacturing the same will be described.

First, when the inner shell tank 2 of the oil storage tank 1 is manufactured, the cylindrical portion 3 is formed by axially joining (welding) each cylindrical body 3A made of a steel plate or the like at each welding portion 3B between them. The flat plate (disk) -shaped end plate portions 4 are joined to both ends of the cylindrical portion 3 by means of annular welding portions 6 and 6 to close both axial ends of the cylindrical portion 3. In this case, as shown in FIG. 3, reinforcing discs 5A and 5B, which are successively formed to have a small diameter, are preliminarily joined to the inner surface of each end plate portion 4 by welding or the like, and the reinforcing discs 5A and 5B are respectively joined. Thus, each flat plate end plate portion 4 can be reinforced from its inner side surface.

Further, an oil-filling pipe 7, an oil-absorbing pipe 8 and the like are joined to the upper end of the cylindrical portion 3 of the inner shell tank 2 by welding, and a leak detecting pipe is formed so as to vertically penetrate through the inner shell tank 2. 9 is provided, and the lower end side of the leak detection tube 9 is connected to the cylindrical portion 3 at the joint 9A so that the leak can be communicated with the inside of the detection space 15. The upper end side of the leak detection pipe 9 is attached to the inner shell tank 2
From above, and a connecting flange 9B for a leak detector (not shown) is integrally provided on the protruding end side.

Next, the outer shell tank 1 is provided outside the inner shell tank 2.
Prior to arranging 0, each resin film 14 is attached to the outer peripheral surface of the cylindrical portion 3 of the inner shell tank 2 and the outer peripheral side of the end plate portion 4 as shown in FIG. In this case, the respective resin films 14 are attached so as to be extended to the outer peripheral surface of the inner shell tank 2 while leaving the upper side 2A of the inner shell tank 2 and the respective cylindrical bodies 3
The welded portions 3B between A and the portions in the vicinity of the welded portions 6 between the cylindrical portion 3 and the end plate portions 4 and the like are covered by utilizing the adhesive action (for example, surface tension) of the resin film 14.

Next, in this state, as shown by the arrows in FIG. 5, each C-shaped ring body 11 is radially outside via the notch portion 11A on the outer peripheral side of each end plate portion 4 of the inner shell tank 2. The respective ring bodies 11 are held in a state in which they are prevented from being pulled out from the respective end plate portions 4 by their elasticity, and the respective curved plates 12A constituting the peripheral body portion 12 of the outer shell tank 10 are attached to the respective cylindrical bodies 3A. To the outer peripheral side of each of the groove portions 12B.

Then, the end portions of the curved plates 12A are joined to each other on the resin film 14 by means of a hand lay-up method or the like, and the joined portions 12C are joined to the end portions of the curved plates 12A as shown in FIG. The curved plate 12A
The groove portion 12B side is joined to the outer peripheral surface on the upper side of the cylindrical portion 3 by a hand lay-up method or the like to form the peripheral body portion 12 of the outer shell tank 10.

Further, both ends in the lengthwise direction of the peripheral body portion 12 are joined to the outer extending portions 11B of the respective ring bodies 11 on the respective resin films 14 by the same means as the above-mentioned hand lay-up method or the like. Then, the outer extending portion 11B of the ring body 11 and the peripheral body portion 12
When a gap, a dent, or the like is formed between the two parts, these parts are filled with putty 16 or the like as shown in FIG. 2 so as to securely seal the two parts and to eliminate surface irregularities. It should be noted that a putty 16 or the like is also used for the joint portion 12C between the curved plates 12A, if necessary.

Further, the flat plate portions 13 of the outer shell tank 10 are arranged on the end plate portions 4 of the inner shell tank 2 radially inside the respective ring bodies 11 so as to be attached as shown in FIG. ,
The outer peripheral side of each flat plate portion 13 is joined to the inner peripheral side of the inner extending portion 11C of each ring body 11 on each resin film 14 by using the same means such as the hand layup method as described above to form an annular joint portion 13.
Form B. Then, the flat plate portion 13 is joined to the end plate portion 4 as shown in FIG. 4 by adhering a region near the cutout portion 13A located on the upper end side of each flat plate portion 13 to the upper end side of each end plate portion 4 of the inner shell tank 2. Then, the outer shell tank 10 is completed.

Thus, according to this embodiment, before forming the outer shell tank 10 on the outer side of the inner shell tank 2, first, the outer peripheral surface of the cylindrical portion 3 of the inner shell tank 2 and the outer peripheral side of the end plate portion 4 are respectively illustrated. As shown in FIG. 5, each resin film 14 is attached, and on each of these resin films 14, between the curved plates 12A of the outer shell tank 10, between the ring body 11 and the peripheral body portion 12, and between the ring body 11 and the flat plate portion 13. Between each joint 12
Since it is configured to be joined by C, 13B, etc., a detection space 15 having a minute gap of approximately 0.1 mm, which substantially corresponds to the thickness of the resin film 14, is provided between the inner shell tank 2 and the outer shell tank 10. It can be formed substantially uniformly over the whole.

In this case, the detection space 15 includes the cylindrical portion 3 (each cylindrical body 3A) of the inner shell tank 2 and the peripheral body portion 12 of the outer shell tank 10.
A space 15A is formed between each of the curved plates 12A, and a space 15B is formed between the end plate portion 4 and the flat plate portion 13.
It has become. However, the respective resin films 14 utilize the adhesion action (for example, surface tension) of the resin film 14 at the welded portions 3B between the cylindrical bodies 3A and the vicinity of the welded portions 6 between the cylindrical portion 3 and the end plate portions 4. Since it is only covered with the resin film 1 between the voids 15A and 15B.
When the liquid leaks into the detection space 15 by communicating with each other at the position of 4, the liquid smoothly flows between the voids 15A and 15B from one side to the other, and the liquid is entirely distributed in the detection space 15. The liquid will stay evenly.

Next, the function of the oil storage tank 1 will be described. For example, an oil liquid F such as gasoline that has been transported to a gas station by a tank truck or the like is injected (supplemented) into the inner shell tank 2.
In this case, the upper end side of the oiling pipe 7 whose lower end side extends into the inner shell tank 2 is connected to a hose (not shown) of a tank truck.
Etc., and the oil liquid F is injected into the inner shell tank 2 from the tank truck via the oiling pipe 7 and the like.

Further, an oil liquid F such as gasoline is applied to the vehicle through a fueling nozzle (not shown) by a weighing machine or the like provided at a fueling station.
When refueling, the inner shell tank 2 is
While sucking the oil liquid F therein through the oil suction pipe 8 or the like, the sucked oil liquid F is supplied to the vehicle from the oil supply nozzle.

By the way, when an unexpectedly large external force acts on the oil storage tank 1 due to an earthquake or the like, and the inner shell tank 2 is damaged or cracked, the oil liquid F in the inner shell tank 2 is detected in the detection space 15. May be leaked to. Even if the outer shell tank 10 is damaged or cracked, groundwater, rainwater, or the like may enter the detection space 15 from the outside of the outer shell tank 10. However, even in this case, since the oil storage tank 1 has the double shell structure, only one of the inner shell tank 2 and the outer shell tank 10 is damaged or cracked, and both are damaged. Such a situation can be reliably prevented.

When the liquid (oil liquid F, groundwater or rainwater) at this time gradually accumulates in the detection space 15, a leak detector provided on the upper end side of the leak detection pipe 9 via a connection flange 9B or the like. Thus, the liquid leakage into the detection space 15 can be detected early, and the liquid leakage can be notified early by an external notification means (not shown) or the like.

Therefore, according to the present embodiment, the inner shell tank 2
Since the end plate portions 4 for closing the cylindrical portion 3 from both ends are formed in a flat disk shape, the end portions of the outer shell tank 10 can be formed by the flat plate portions 13 in the same manner as in the prior art. There is no need to perform special spherical surface processing, etc. Then, the gap size of the detection space 15 formed between the outer shell tank 10 and the inner shell tank 2 can be made substantially even over the whole, and at the time of manufacturing the entire inner shell tank 2 and the outer shell tank 10. The workability in (manufacturing) can be surely improved, and the manufacturing and assembling work of the inner shell tank 2 and the outer shell tank 10 can be greatly simplified.

Further, the outer shell tank 10 is provided with each ring body 11,
It is composed of the peripheral body portion 12 (each curved plate 12A) and each flat plate portion 13, and prior to disposing them on the outside of the inner shell tank 2, the detection space 15 is provided between the inner shell tank 2 and the outer shell tank 10. Each resin film 14 (space forming material) for forming the outer peripheral surface of the cylindrical portion 3 of the inner shell tank 2 and the boundary portion (each welding portion 6) between the outer cylindrical portion 3 and each end plate portion 4 from the outside. The inner shell tank 2 and the outer shell tank 10 (each ring body 11, each curved plate portion 12) are attached so as to cover the inner shell tank 2 and the outer shell tank 10.
A detection space 15 for leak detection can be easily formed between A and each flat plate portion 13) with a uniform gap size.

That is, the peripheral body portion 12 is formed on each resin film 14.
Each of the curved plates 12A, the ring body 11 and the peripheral body portion 12 and the ring body 11 and the flat plate portion 13 are joined by the joint portions 12C and 13B, respectively. Even if the joint portions 12C, 13B and the like are respectively joined (adhered) to the respective resin films 14, the respective resin films 14 can reliably prevent the joined portions (adhesion) from being adhered to the outer surface of the inner shell tank 2. Between the shell tank 2 and the outer shell tank 10, a detection space 15 having a minute gap of approximately 0.1 mm, which substantially corresponds to the thickness of the resin film 14, can be formed substantially evenly over the whole.

Further, each ring body 11 of the outer shell tank 10
Has a C-shape as a whole, and the portion corresponding to the upper side of the inner shell tank 2 is formed as a cutout portion 11A so that the diameter can be reduced and expanded, so that the ring body 11 is cutout portion 11A.
It can be easily attached to the outer peripheral side of the end plate portion 4 of the inner shell tank 2 through the use of the ring body 11 and has a stable strength between the peripheral body portion 12 (curved plate 12A) and the flat plate portion 13 with high strength. And the welded portion 6 between the cylindrical portion 3 and the end plate portion 4 of the inner shell tank 2 reduces the joint strength between the peripheral body portion 12 and the flat plate portion 13 of the outer shell tank 10. Can be eliminated.

Further, each resin film 14 is provided on the welded portion 3B between the cylindrical bodies 3A, the welded portion 6 between the cylindrical portion 3 and each end plate portion 4, etc., while leaving the upper side 2A of the inner shell tank 2. In the attached state, between the curved plates 12A of the peripheral body portion 12 from above,
Since the ring body 11 and the peripheral body portion 12 are joined by the joint portion 12C or the like, the joint portion 12C of the outer shell tank 10 is formed.
It is possible to effectively increase the joint strength due to the above, and to significantly improve the reliability and durability of the double shell tank.

Next, FIGS. 6 and 7 show a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. The feature of the present embodiment is that the outer shell tank 21 is composed of a peripheral body portion 22 formed of a long curved plate, and a pair of flat plate portions 23, 23 joined to both ends of the peripheral body portion 22 in the longitudinal direction. Prior to disposing the peripheral body portion 22 and the flat plate portions 23 on the outer side of the inner shell tank 2, a release agent is applied to the outer surface of the inner shell tank 2 in advance.

Here, the peripheral body portion 22 of the outer shell tank 21 is constructed in substantially the same manner as each curved plate 12A of the peripheral body portion 12 described in the first embodiment, and the upper end side thereof is formed as a groove portion 22A. The peripheral body portion 22 is formed with a length (width dimension) substantially corresponding to the entire length of the inner shell tank 2. The peripheral body portion 22 is made of a single sheet of fiber reinforced resin, and surrounds the entire outer peripheral surface of the cylindrical portion 3 except the upper side 2A of the inner shell tank 2.

Further, each flat plate portion 23 of the outer shell tank 21 is constructed in the same manner as each flat plate portion 13 described in the first embodiment, and the cutout portion 23A is formed on the upper end side thereof. The outer peripheral side of each flat plate portion 23 is directly joined to both end sides in the length direction of the peripheral body portion 22 by each joint portion 24.

Next, the method of manufacturing the oil storage tank 1 according to the present embodiment will be described.
Of the inner shell tank 2 except for the upper side 2A of the inner shell tank 2 (below the release agent application level 25 shown by the phantom line in FIG. 7). Position) is coated with a release agent with a substantially uniform thickness over the entire surface.

Next, a fiber reinforced resin material is applied onto the outer surface of the inner shell tank 2 from above the release agent, and the peripheral body portion 22 is provided on the cylindrical portion 3 and each end plate portion 4 of the inner shell tank 2.
The outer shell tank 21 is formed by attaching the flat plate portions 23 and forming the joint portions 24 between the outer peripheral side of each flat plate portion 23 and both end sides of the peripheral body portion 22.

In this case, in the state shown in FIG. 7, the peripheral body portion 22 and each flat plate portion 23 are formed only from a glass fiber woven sheet, and the woven sheet is impregnated with an epoxy resin or the like to form an inner shell. The outer shell tank 21 may be formed by applying it on the cylindrical portion 3 and each end plate portion 4 of the tank 2.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same operation and effect as in the first embodiment. However, particularly in this embodiment, before the outer shell tank 21 is manufactured. By applying a release agent to the outer surface of the inner shell tank 2 in advance, the fiber reinforced resin material (the peripheral body portion 22 and each flat plate portion 23) of the outer shell tank 21 is adhered to the outer surface of the inner shell tank 2. It is possible to prevent the leakage, and a detection space 15 for leak detection is provided between the outer shell tank 21 and the inner shell tank 2.
Can be easily formed.

Next, FIG. 8 shows a third embodiment of the present invention. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. To do. However, the present embodiment is characterized in that the end plate portion 4 of the inner shell tank 2 is located on the inner surface side thereof and has a substantially cross-shaped reinforcing plate 31A,
31B is configured to be joined by means such as welding.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as the first embodiment, and the end plate portion 4 for the oil liquid F and the like contained in the inner shell tank 2 can be obtained. It is possible to reliably increase the pressure resistance of the.

Next, FIG. 9 shows a fourth embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. To do. However, the feature of this embodiment is that a plurality of reinforcing plates 41A, 41B, 41C, 41D that are located on the inner surface side of the end plate portion 4 of the inner shell tank 2 and extend parallel to each other in the vertical direction are provided with means such as welding. It is configured to be joined by using.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effects as the first embodiment, and the end plate portion 4 for the oil liquid F and the like contained in the inner shell tank 2 can be obtained. It is possible to reliably increase the pressure resistance of the.

In the first embodiment, the peripheral body 12 of the outer shell tank 10 is provided with three curved plates 12A, 12A, 12A.
Although it has been described as being constituted by A, instead of this, for example, as in the case of the circumferential body portion 22 used in the second embodiment,
It may be formed by one curved plate, or may be formed by two or four or more curved plates. Further, the peripheral body portion 22 described in the second embodiment may also be formed by two or more curved plates. In this case, the number of curved plates should correspond to the number of each cylindrical body 3A. Due to
The curved plates can be bonded to each other with high strength at the positions of the welded portions 3B via the resin films 14, respectively.

On the other hand, in each of the above-mentioned embodiments, the leak detection pipe 9 is described as being provided so as to penetrate through the inner shell tank 2 in the vertical direction, but instead of this, for example, Japanese Patent Laid-Open No. 59-1429.
As with the double tank described in Japanese Patent Publication No. 82, the outer shell tank 1
You may make it connect and provide a leak detection pipe on the upper side of 0 (21).

In each of the above embodiments, the oil supply pipe 7, the oil absorption pipe 8 and the leak detection pipe 9 are provided on the upper end side of the inner shell tank 2, but the present invention is not limited to this, and the inner shell tank is not limited to this. In addition to the oil injection pipe 7, the oil absorption pipe 8 and the leak detection pipe 9 on the upper end side of 2, a mounting pipe for a liquid level gauge for detecting the liquid level of the oil liquid F contained in the inner shell tank 2, and a vapor, for example. A configuration may be adopted in which a discharge pipe or the like is appropriately connected and provided.

Further, in each of the above-mentioned embodiments, the case where the double shell tank is applied to the oil storage tank 1 as an underground tank buried underground in the gas station has been described as an example, but the present invention is not limited to this. However, the present invention can be applied to, for example, an underground tank having a double shell structure that stores various oil liquids and liquids.

[0071]

As described in detail above, according to the invention as set forth in claim 1, since the closed portions located at both ends of the tubular portion of the inner shell tank are formed in a flat plate shape, the outer shell tank is formed. Both ends of the can be formed in a flat plate shape like this, and there is no need to perform special spherical processing, etc. as in the prior art, and when manufacturing the entire inner shell tank and outer shell tank (when manufacturing)
The workability of the outer shell tank can be reliably improved, and the gap size of the space formed between the outer shell tank and the inner shell tank can be reduced almost evenly over the whole, and the manufacturing and assembling work of the outer shell tank can be significantly improved. Can be simplified to

In this case, as in the invention described in claim 2, the outer shell tank is composed of each ring body, the curved plate portion and each flat plate portion, and prior to disposing these outside the inner shell tank, A space forming material for forming a space portion between the inner shell tank and the outer shell tank is provided so as to cover at least a boundary portion between the tubular portion of the inner shell tank and each closed portion from the outside, By joining the curved plate portion to the outer peripheral side of the ring body on the space forming material and the flat plate portion to the inner peripheral side of the ring body, these joint portions are joined (bonded) to the space forming material. ), The space forming material can surely prevent the inner shell tank from being bonded (bonded) to the outer surface of the inner shell tank.
A space for leak detection can be easily formed between the curved plate portion and the flat plate portion.

Further, since the ring body of the outer shell tank has a C shape as a whole, and the portion corresponding to the upper side of the inner shell tank is formed as a notch so that the diameter can be reduced and expanded. The ring body can be easily attached near the boundary portion between the tubular portion and the closed portion of the inner shell tank via the notch portion, and the curved plate portion and the flat plate are provided by the C-shaped ring body which covers the boundary portion. It is possible to join the parts with high strength in a stable state, and it is possible to solve problems such as a decrease in the joining strength between the curved plate part and the flat plate part of the outer shell tank, and reliability as a double shell tank. And durability can be significantly improved.

Further, in the invention described in claim 3, after the inner shell tank is manufactured as the container for containing the liquid from the cylindrical portion and the flat plate-shaped closing portions provided on both ends thereof, the inner shell tank is manufactured. Since a mold release agent is applied to the outer surface of the inner shell tank except for the upper side, the outer shell tank is formed by applying a fiber reinforced resin material to the outer surface of the inner shell tank from above. The release agent applied to the outer surface of the inner shell tank can prevent the fiber reinforced resin material for the outer shell tank from adhering to the outer surface of the inner shell tank, and thus the outer shell tank and the inner shell tank A space for leak detection can be easily formed between them, and the manufacturing process of the outer shell tank can be simplified, resulting in a significant cost reduction.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an oil storage tank according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 showing an enlarged main part such as a welded portion between the cylindrical portion and the end plate portion of the inner shell tank, the ring body and the peripheral body portion of the outer shell tank.

FIG. 3 is an explanatory view showing an inner surface side of an end plate portion provided in the inner shell tank.

FIG. 4 is an overall perspective view of the oil storage tank shown in FIG.

5 is an exploded perspective view of the oil storage tank shown in FIG.

FIG. 6 is an overall perspective view of an oil storage tank according to a second embodiment of the present invention.

FIG. 7 is an exploded perspective view of the oil storage tank shown in FIG.

FIG. 8 is an explanatory view similar to FIG. 3, showing a third embodiment of the present invention.

FIG. 9 is an explanatory view similar to FIG. 3, showing a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Oil storage tank (double shell tank) 2 Inner shell tank 2A Upper side 3 Cylindrical part (cylindrical part) 4 End plate part (closed part) 5A, 5B Reinforced disc 6 Weld part (boundary part) 9 Leakage detection tube 10, 21 Outer shell tank 11 Ring body 12,22 Circumferential body part (curved plate part) 12A Curved plates 12C, 13B, 24 Joint part 13,23 Flat plate part 14 Resin film (space forming material) 15 Detection space (space part) 25 Release agent Application level 31A, 31B, 41A to 41D Reinforcing plate F Oil liquid

Claims (3)

[Claims] 1. An inner shell tank formed as a container for containing a liquid by a tubular portion and flat plate-shaped closed portions provided at both ends of the tubular portion; and an inner shell tank made of a fiber reinforced resin material, An outer shell tank that surrounds the inner shell tank from the outside so as to form a double shell structure leaving the upper side of the shell tank, and for leak detection defined between the outer shell tank and the inner shell tank. A double-shell tank composed of the space part of 2. The inner shell tank is provided with a space forming member that covers at least a boundary portion between the tubular portion and each closed portion from the outside in order to form a space portion between the inner shell tank and the outer shell tank, In the outer shell tank, a portion corresponding to the upper side of the inner shell tank is formed as a cutout portion so that the diameter can be reduced and expanded, and the outer shell tank is provided in the vicinity of a boundary portion between the tubular portion and each closed portion of the inner shell tank. A C-shaped ring body provided via a space forming material, and a curved plate portion arranged on the outer peripheral side of the tubular portion of the inner shell tank and joined to the outer peripheral side of the ring body on the space forming material. The double shell according to claim 1, wherein the double shell includes a flat plate portion disposed on a closed portion of the inner shell tank and having an outer peripheral side joined to an inner peripheral side of the ring body on the space forming material. tank. 3. An inner shell tank formed as a container for containing a liquid by a tubular portion and flat plate-shaped closed portions provided at both ends of the tubular portion, and an inner shell tank made of a fiber reinforced resin material, An outer shell tank that surrounds the inner shell tank from the outside so as to form a double shell structure leaving the upper side of the shell tank, and for leak detection defined between the outer shell tank and the inner shell tank. A method of manufacturing a double-shell tank comprising a space part of the inner shell tank except the upper side of the inner shell tank for forming the space part between the inner shell tank and the outer shell tank. A step of applying a release agent to the outer surface of the outer shell tank and a step of forming the outer shell tank by applying a fiber reinforced resin material to the outer surface of the inner shell tank via the release agent. Heavy shell tank manufacturing method.