JPWO2013021821A1 - Side wall unit and manufacturing method thereof, and liquid storage tank provided with the side wall unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a side wall unit constituting at least a part of a liquid storage tank in which liquid leakage from a joint portion between units does not occur even when a large volume of liquid is accommodated. A method for manufacturing a side wall unit includes a first bonded structure forming step, a strain removing step, a second bonded structure forming step, and a side wall unit assembling step. A distortion removal process is a process of removing distortion resulting from heat at the time of welding a member. In this step, before the joining structure and the side wall plate are joined, a force in a direction substantially perpendicular to the flange surface and / or a force in a direction substantially horizontal to the flange surface is applied to the joining structure. The liquid storage tank using the side wall unit according to the present invention can reliably prevent liquid leakage even when a large volume of liquid is accommodated. [Selection] Figure 3

Description

  The present invention relates to a prefabricated liquid storage tank. More specifically, the present invention is an assembly-type liquid storage tank composed of a plurality of units so that liquid leakage does not occur from the joint between the units even when a large volume of liquid is accommodated therein. The present invention relates to a side wall unit and a manufacturing method thereof.

  As a liquid storage tank having a space for storing a liquid therein, an assembly type tank is generally adopted unless a seamless structure can be adopted. The assembly-type liquid storage tank is manufactured in advance as a plurality of units having a predetermined size suitable for transportation in a manufacturing factory or the like. The manufactured units are usually transported to the installation site by a vehicle and assembled. At the installation site, the liquid storage tank can be assembled by joining a plurality of units in the circumferential direction to form a cylindrical member and overlapping the plurality of cylindrical members in the height direction. Here, in this specification, the “circumferential direction” means a direction parallel to the ground in the liquid storage tank, and the “height direction” means a direction crossing the circumferential direction. As such an assembly-type liquid storage tank, various tanks including a cylindrical storage tank described in, for example, Japanese Patent Application Laid-Open No. 2009-12849 have been proposed.

  In such an assembly-type liquid storage tank, it is important how to prevent leakage of liquid from a joint portion between units. In the existing assembly-type liquid storage tank, for example, the following techniques have been proposed in order to prevent liquid leakage.

  The technique described in Patent Document 2 (Japanese Patent Publication No. 63-6432) prevents leakage by devising the structure of the joint portion between the units. The technique described in Patent Document 2 is to devise the edge structure of each unit as shown in the claims and FIGS. 5 and 6, and a trough is attached to the joint portion of the two units. It has been proposed to form and fill the trough with a pasty seal member. Many other techniques for preventing liquid leakage by devising the structure of the joint portion, such as the technique described in Patent Document 2, have been proposed.

  The technique described in Patent Document 3 (Japanese Patent Application Laid-Open No. 2010-13155) prevents leakage by devising a construction method of a sealing material at a joint portion. In the technique described in Patent Document 3, a moisture-curing sealing material is applied to the joint portion between the units from the side corresponding to the inside of the tank. Thereafter, when the surface of the sealing agent is cured, the tank is filled with water. When the tank is filled with water, the joint portion is opened by the pressure of the water, and the uncured sealing agent enters the inside of the joint portion, thereby increasing the water stoppage of the joint portion.

  The technique described in Patent Document 4 (Japanese Patent Application Laid-Open No. 2005-105083) prevents leakage by combining the idea of the joint filling adhesive itself with the idea of the structure of the joint portion. In the technique described in Patent Document 4, an adhesive for filling a tank joint is used, which includes a one-component moisture-curable resin as a main component, a silane coupling agent as an adhesion-imparting agent, and a fiber filler. Prevent leakage from the joint between the units. Further, a metal pressing member is placed over the flange filled with the joint filling adhesive so as to cover the entire flange.

  In Patent Document 5 (Japanese Patent Application Laid-Open No. 8-26381), in a liquid storage tank configured by joining edge portions of a plurality of plate-like bodies to each other, the storage performance is not deteriorated, and assembling is not performed. There has been proposed a liquid storage tank capable of improving workability and reducing cost. In the assembly-type liquid storage tank, it is necessary to consider the workability when the liquid storage tank is assembled by joining the units.

JP 2009-12849 A Japanese Examined Patent Publication No. 63-6432 JP 2010-13155 A JP 2005-105083 A JP-A-8-26381

  In an assembly-type liquid storage tank, it is naturally assumed that liquid leakage from the joint is surely prevented, but from the viewpoint of ease of assembly and disassembly at the installation site and manufacturing cost. In addition, it is also required to simplify the structure of the joining portion between the units constituting the liquid storage tank and the joining method in the field as much as possible. Therefore, in order to simplify the assembly process at the installation site, large-capacity liquid storage tank units are simply made so that the joining flanges face each other at the time of joining the units, and the joining flanges are mechanically arranged such as nuts and bolts. It is preferable that the tank is configured to be assembled only by joining using a fastener. Such a simple structure unit is advantageous from the viewpoint of manufacturing cost.

  In addition, there is an advantage that the liquid storage tank can be easily disassembled by employing such a joining structure and method. Large-capacity liquid storage tanks may be in the form of lease supply from a leasing company that owns the tank, rather than being owned by the company that needs the tank. Such a tank is advantageous from the viewpoint of construction period and cost if it can be easily disassembled when returned to the leasing company after use.

However, in a large-capacity liquid storage tank of 1,000 m ³ or more, for example, the internal pressure acting on the units located at the bottom of the tank becomes extremely large, so that there is only a slight distortion on the joint flange surface of these units. However, there was a problem that the liquid inside leaked from the joint between the units.

  Various conventional techniques including the above-described techniques have been proposed in order to prevent liquid leakage. However, these conventional techniques can eliminate distortion at the joint caused by welding heat during tank assembly. In particular, it is extremely difficult to solve the leakage problem in a large-capacity liquid storage tank containing a certain volume or more of liquid, and in view of the ease of assembly and disassembly on the installation site and the manufacturing cost. In many cases, it was difficult to adopt a large-capacity liquid storage tank.

  The present invention relates to a side wall unit constituting at least a part of a liquid storage tank that does not cause liquid leakage from a joint portion between units even when a large volume of liquid of a certain level or more is accommodated, and a liquid storage using such a side wall unit The purpose is to provide a tank.

  The above-described problem is a process of accurately eliminating distortion caused by welding heat at a joint portion for joining with another side wall unit during the process of manufacturing each of the side wall units constituting at least a part of the liquid storage tank. And in the side wall unit, the structure of the joint portion including the joint flange is made to be a structure that does not cause distortion of the joint portion even during long-term use while ensuring workability at the time of joining. Can do.

  According to a first aspect, the present invention provides a method of manufacturing a side wall unit used in the manufacture of a liquid storage tank having at least a bottom wall and a side wall. The side wall is configured by one cylindrical member or by stacking a plurality of cylindrical members in the height direction, and at least one of the cylindrical members is configured by joining a plurality of side wall units in the circumferential direction. The The method includes a step of preparing a member constituting the side wall unit, a first bonded structure forming step, a first strain removing step, a second bonded structure forming step, and a side wall unit assembling step. In the step of preparing the member, a rectangular side wall plate and a member included in the joint structure attached to each of the two circumferential edges facing the side wall plate are prepared. And a base member having a short side, a circumferential joint flange having a long side and a short side, and a plurality of reinforcing members having two adjacent edges intersecting at a predetermined angle.

  In the first joint structure forming step, the long side of the circumferential joint flange is such that the non-flange surface opposite to the flange surface of the circumferential joint flange intersects one surface of the base member at a predetermined angle. And the long side of the base member are parallel to each other, and the circumferential joining flange and the base member are coupled to each other, and a plurality of reinforcing members are mutually connected to the inner corner formed by the non-flange surface and one surface. The first joint structure is formed by joining at least a part of each of the two adjacent edges with the non-flange surface and the one surface so as to stand up at intervals. For the first joint structure formed in this way, in the first strain step, a force directed from the non-flange surface to the flange surface respectively at the longitudinal central portion and both longitudinal end portions of the first joint structure. And the force from the flange surface toward the non-flange surface are simultaneously applied to remove the distortion of the first joint structure.

  The method further includes a second bonding structure forming step of preparing a member, forming a first bonding structure, and forming a second bonding structure by a process similar to the process of removing the distortion. , One of the opposed circumferential edges of the curved side wall plate is coupled to the long side of the base member of the first joint structure, and the other of the circumferential edge and the long side of the base member of the second joint structure And a side wall unit assembly process.

  Also in the second aspect of the present invention, as in the first aspect, the present invention provides a method for manufacturing a side wall unit used in the manufacture of a liquid storage tank having at least a bottom wall and a side wall. The side wall is configured by one cylindrical member or by stacking a plurality of cylindrical members in the height direction, and at least one of the cylindrical members is configured by joining a plurality of side wall units in the circumferential direction. The In the first aspect, this method replaces the first bonded structure forming step and the first strain removing step performed as separate steps in the first aspect, and forms the first bonded structure while removing the strain. And a first bonded body forming step.

  In the first strain removal and first joined body forming step, first, the circumferential flange is formed such that the non-flange surface opposite to the flange surface of the circumferential joint flange intersects one surface of the base member at a predetermined angle. In a positional relationship in which the long side of the directional joining flange and the long side of the base member are parallel, the circumferential joining flange and the base member are temporarily joined, and at the inner angle formed by the non-flange surface and one surface The first intermediate body is created by temporarily joining at least a part of each of the two adjacent edges to the non-flange surface and the one surface so that the plurality of reinforcing members stand up at intervals from each other. . Subsequently, a 2nd intermediate body is created by the same process as the process of creating a 1st intermediate body. Next, in a state where the first intermediate body and the second intermediate body are temporarily assembled and constrained via the respective flange surfaces, at least the circumferential joint flange of the first intermediate body, the base member, and each of the plurality of reinforcing members, Are finally coupled to each other, and finally the temporary assembly of the first intermediate body and the second intermediate body is released to obtain the first bonded structure. The second bonding structure may be formed from a second intermediate.

  In one embodiment of the second aspect, after the first strain removal and the first bonded structure forming step, the longitudinal center portion and both longitudinal ends of the first bonded structure with respect to the first bonded structure. A second strain removal that removes the strain of the first joint structure by simultaneously applying a force in the direction from the non-flange surface to the flange surface and a force in the direction from the flange surface to the non-flange surface. A process can be further included.

  In one embodiment of the first and second aspects, with respect to the first joint structure, the one side of the base member from the one surface of the base member is disposed at the longitudinal central portion and both longitudinal ends of the first joint structure. A third strain that eliminates the strain of the first joint structure by simultaneously applying a force in the direction of the other surface opposite to the first surface and a force in the direction of the first surface from the other surface. A removal step can be further included.

  In one embodiment, the joining of the members and / or the temporary joining includes joining the circumferential joining flange and each of the plurality of reinforcing members, joining the circumferential joining flange and the base member, and joining the plurality of reinforcing members and the base. The step of joining the members can be performed in this order. In another embodiment, the joining of the members and / or the temporary joining includes a step of joining the circumferential joining flange and the base member, and joining each of the plurality of reinforcing members to the circumferential joining flange and the base member. This can also be done in this order. In addition, the circumferential joining flange, the base member, and the plurality of reinforcing members are joined and / or temporarily joined from the joining portion near the center to the joining portion in the short side direction with respect to the long side direction of the circumferential joining flange. Are preferably performed sequentially.

  According to the present invention, in the manufacturing process of the side wall unit constituting at least a part of the liquid storage tank, the distortion of the circumferential joint flange caused by the welding heat when the members constituting the side wall unit are joined together is effectively prevented. Since it can be removed, the sidewall units can be joined with high accuracy. Further, instead of directly coupling the circumferential joining flange and the side wall plate, a base member as a rigid body having a short side of a predetermined length is interposed between the circumferential joining flange and the side wall plate. Further, it is possible to reduce the occurrence of distortion of the circumferential joining flange due to the welding heat between the base member and the side wall plate. Furthermore, when a high internal pressure is applied by the liquid in the tank, the conventional technology in which the joint flange and the side wall plate are directly coupled cannot maintain the angle between the two, and the flange surface of the adjacent joint flange opens from the inside. In some cases, according to the present invention, by interposing a base member as a rigid body thicker than the side wall plate between them, the angle between the base member and the circumferential joining flange is maintained, so that The flange surfaces of the circumferential joining flanges do not open, and the joining property between the circumferential joining flanges can be improved.

  In another embodiment of the present invention, it is preferable that the plurality of reinforcing members are coupled with a narrower interval in the central portion in the long side direction compared to the interval in the end portion in the long side direction of the circumferential joining flange. The reinforcing member is a plate-like body, is longer than the short side of the base member, and intersects the first edge coupled to the base member and the side wall plate at a predetermined angle with respect to the first edge. A second edge coupled to the flange surface, a first edge opposite the third edge having a length corresponding to the short side of the base member, and a second edge; A fourth edge portion connecting one end of the first edge portion and one end of the third edge portion may be included. In the plurality of reinforcing members, either one of the portion corresponding to the intersection of the first edge and the second edge and the portion corresponding to the coupling position of the base member and the side wall plate in the first edge or It is more preferable that notches are formed on both.

  By adopting such an installation position and shape of the reinforcing member, it is possible to weld the two while maintaining the angle between the circumferential joining flange and the base member. In addition, since the angle between the circumferential joint flange and the base member is maintained even when a high internal pressure is applied by the liquid in the tank, the plurality of reinforcing members do not open the flange surface of the adjacent circumferential joint flange. Liquid leakage can be prevented.

  In another embodiment of the present invention, the method preferably further comprises the step of forming a plurality of holes for passing mechanical fasteners over the long sides of the circumferential joining flange, wherein the plurality of holes are It is preferable that the diameter in the central part in the long side direction is larger than the diameter in the long side direction end part of the circumferential joining flange. Moreover, it is preferable that this method further includes the process of forming the groove | channel for putting a sealing layer in the flange surface of a circumferential direction joining flange.

  As described above, by changing the strength of the mechanical fastener used for joining the circumferential joining flanges in the height direction, the joining strength between the circumferential joining flanges can be further increased. In addition, by providing a groove on the flange surface for forming a seal layer on the flange surface, it is possible to further prevent the leakage of the liquid inside, and to prevent the position of the seal layer from shifting when the liquid storage tank is assembled. It can be avoided.

  According to the third aspect of the present invention, at least a bottom wall and a side wall constituted by one cylindrical member or a side wall constituted by stacking a plurality of cylindrical members in the height direction are provided. A side wall unit constituting a cylindrical member is provided that is used in a liquid storage tank in which at least one of the cylindrical members is formed by joining a plurality of side wall units in the circumferential direction. The side wall unit includes a curved rectangular side wall plate and a pair of joint structures attached to each of two opposing circumferential edges of the side wall plate, each of the pair of joint structures having a short side and It includes a base member having a long side, a circumferential joining flange having a short side and a long side, and a plurality of reinforcing members having two adjacent edges that intersect at a predetermined angle.

  The circumferential joining flange and the base member are arranged so that the non-flange surface opposite to the flange surface of the circumferential joining flange and one surface of the base member intersect at a predetermined angle with the long side of the circumferential joining flange. The base members are coupled in a positional relationship in which the long sides of the base members are parallel to each other. The plurality of reinforcing members are arranged such that each of the two adjacent edges has a non-flange surface and one surface, respectively, so that they stand up at an inner angle side formed by the non-flange surface and one surface of the base member. And is bound to. Furthermore, the long side of the base member in each of a pair of joining structure bodies is couple | bonded with each of the circumferential direction edge part which a side wall board opposes.

  By using the side wall unit having such a structure, the angle between the circumferential joining flange and the base member can be maintained, and even when the internal pressure is applied by the liquid in the tank, the circumferential joining flange and the base member are separated from each other. Since the angle between them is maintained, the flange surfaces of adjacent circumferential joining flanges do not open, and liquid leakage can be prevented.

  According to a fourth aspect, the present invention provides a liquid storage tank comprising a sidewall unit manufactured using the method according to any of claims 1-16.

  According to a fifth aspect, the present invention provides a liquid storage tank comprising the side wall unit according to any one of claims 17 to 25.

  According to the present invention, it is possible to obtain a liquid storage tank capable of reliably preventing liquid leakage even when a large volume of liquid is accommodated.

FIG. 4 is a perspective view of a large-capacity liquid storage tank assembled using a side wall unit according to an embodiment of the present invention. It is a perspective view of the mass liquid storage tank assembled using the side wall unit by another embodiment of the present invention. It is a perspective view of the side wall unit by one Embodiment of this invention. FIG. 4 is a perspective view of a part of a joining structure and a side wall plate included in the side wall unit shown in FIG. 3. It is a perspective view which shows another embodiment of a joining structure. It is a perspective view which shows another embodiment of a joining structure. (A) It is a perspective view which shows the shape of the reinforcement member shown by FIG. (B) It is a perspective view which shows another shape of a reinforcement member. It is a figure for demonstrating the method of removing the distortion of a joining structure body. It is a figure for demonstrating the method of removing the distortion | strain of the joining structure in a direction different from FIG. It is a figure for demonstrating the method to form a joining structure, removing the distortion of a joining structure. It is a figure for demonstrating the method to form a joining structure, removing the distortion of a joining structure. It is a perspective view which shows the recessed part for arrange | positioning the sealing layer provided in the joining flange surface. It is a perspective view of the side wall unit provided with the height direction joining flange.

Embodiments of the present invention will be described below with reference to the drawings.
1. Side Wall Unit Structure FIG. 1 shows an example of a large-capacity liquid storage tank assembled using a side wall unit according to an embodiment of the present invention. The side wall unit includes a joint structure at both circumferential ends, and the joint structure includes a circumferential joint flange. The liquid storage tank includes a plurality of cylindrical members formed by joining a plurality of side wall units in the circumferential direction by joining the joined structures to each other via a circumferential joining flange, and joining the plurality of side wall units together. It is assembled by stacking in the height direction on a separately manufactured bottom wall. In the present specification, the “tubular member” is not limited to a circular cylindrical body, and may include a polygonal cylindrical body. The number of side wall units and the number of cylindrical members used are not limited, and can be appropriately selected according to the size and application of the liquid storage tank. The side wall unit according to the present invention is more preferably used for a large-capacity liquid storage tank having a capacity of at least 1,000 m ³ , for example, an inner diameter of 12 m or more, a height of 10 m or more, and a capacity of 1, Even if it is a case where it is used for a liquid storage tank of 200 m ³ or more, it is possible to reliably prevent liquid leakage from the joint portion between the side wall units.

  The side wall unit according to the present invention is manufactured by a manufacturing process including a process of removing the thermal strain of the joint structure generated by welding, and even if a high internal pressure is applied to the liquid storage tank due to the presence of this strain removing process, A side wall unit in which liquid does not leak can be obtained from a joint portion between the side wall unit and the side wall unit. Further, the joined structure of the side wall unit according to the present invention has a special structure as will be described in detail below. With this structure, even when a high internal pressure is applied, the circumferential joining flange and the base member Therefore, the joint structure can be prevented from being deformed. Furthermore, this structure does not deform the joint portion between the joined structure and the side wall plate, and therefore, as a matter of course in the short term, even when a high internal pressure is applied over a long period of time, the liquid leakage preventing effect is achieved. Extremely high. In the large-capacity liquid storage tank, the internal pressure applied to the side wall becomes extremely large particularly under the tank. Therefore, it is not considered to remove the thermal strain at the time of manufacturing at the joint portion between the units. In a conventional unit that does not have such a special structure, liquid leakage from the joint portion cannot be reliably prevented.

  The following two forms are mainly conceivable for the liquid storage tank using the sidewall unit, and the sidewall unit according to the present invention can be used in any form of liquid storage tank including these forms. One of the two forms is a cylindrical member stacking type liquid storage tank 1 as shown in FIG. 1, for example. This is a cylindrical member 2 by joining a plurality of side wall units 10 each having a joining structure attached to each of the circumferential edges of the laterally long side wall plate (that is, the short side of the side wall plate), A plurality of cylindrical members 2 are stacked in the height direction on the bottom wall, and the plurality of cylindrical members 2 are used as side walls. Since the internal pressure applied to the upper side of the liquid storage tank 1 is lower than that of the lower side, in this case, it is not always necessary to use the side wall unit 10 according to the present invention for the cylindrical member 2 constituting the upper side wall. Absent. That is, the side wall unit according to the present invention can be used as a unit located below the liquid storage tank 1, and a conventional unit can be used as a unit located above.

  The second form is a single cylindrical member type liquid storage tank 1 'as shown in FIG. 2, for example. This is because a plurality of side wall units 10 ′ each having a joining structure attached to each of circumferential edges (ie, long sides of the side wall plate) of the vertically long side wall plate are joined in the circumferential direction to form a cylindrical shape on the bottom wall. The member 2 ′ is made, and this one cylindrical member is used as the side wall of the liquid storage tank 1 ′. In the case of this form, it is necessary to make all the units side wall units according to the present invention.

  Here, the structure of the side wall unit 10 according to an embodiment of the present invention will be described using the stacked liquid storage tank 1 shown in FIG. 1 as an example. FIG. 3 shows a side wall unit 10 according to one embodiment of the present invention. The side wall unit 10 includes a side wall plate 12 and two joining structures 22 and 24 attached to each of two opposing circumferential edges 14 and 16 of the side wall plate 12. In the following, as shown in FIG. 1, the present invention will be described based on an example in which one cylindrical member 2 is constituted by four horizontally long side wall units.

[Joint structure]
FIG. 4A shows the joint structure 22 attached to the circumferential edge 14 of the side wall plate 12. In general, the bonding structure 24 also has the same structure as the bonding structure 22, and therefore, only the structure of the bonding structure 22 will be described below in detail. The joint structure 22 includes a base member 26, a circumferential joint flange 28, and a plurality of reinforcing members 30. In FIG. 4A, the side wall plate 12 attached to the joint structure 22 is also shown.

  The base member 26 and the circumferential joint flange 28 are arranged such that a non-flange surface 28A opposite to the flange surface 28B of the circumferential joint flange 28 and one surface 26A of the base member 26 intersect at a predetermined angle. Combined. This predetermined angle is an angle determined according to the diameter of the liquid storage tank 1, and is preferably 90 degrees or larger. That is, in the liquid storage tank 1, the base member 26 is disposed along the wall surface of the cylindrical tank 1 with the main surface (that is, the surface 26 </ b> A), whereas the flange surface 28 </ b> B of the circumferential joint flange 28 is The liquid storage tank 1 needs to be arranged perpendicular to the wall surface. Therefore, the intersection angle between the non-flange surface 28A of the circumferential joining flange 28 and the one surface 26A of the base member 26 is 90 degrees or larger. This angle can approach 90 degrees as the diameter of the assembled liquid storage tank 1 increases, and can be increased as the diameter decreases. The positional relationship between the long side 28L of the circumferential joining flange 28 and the long side 26L of the base member 26 can be substantially parallel. In FIG. 4A, the base member 26 is shown to stand up from the short-side end of the non-flange surface 28 </ b> A of the circumferential joint flange 28, but other than the end of the non-flange surface 28 </ b> A of the circumferential joint flange 28. For example, the base member 26 may stand up from the position near the center with respect to the short side direction. In this case, as shown in FIG. 4B, the circumferential joining flange 28 of the side wall unit 10 also enters the inside of the liquid storage tank 1, and the adjacent circumferential joining flange also in this inner portion. By joining 28 using, for example, a mechanical fastener, the joining strength between adjacent circumferential joining flanges can be further increased, and a higher liquid leakage prevention effect can be achieved.

  In FIG. 4A, the base member 26 is shown to stand up from the non-flange surface 28A, but the circumferential joining flange 28 stands up from the short-side end of one surface 26A of the base member 26. It may be. However, in such a configuration, by welding the joint portion between the circumferential joint flange 28 and the base member 26 at the joint surface when the joint structure 22 is joined to another joint structure. Since a process for flattening the coupling surface is essential, not only the number of processes is increased, but as a result of the process, the flange surface 28B of the circumferential joint flange 28 and the end surface of the long side 26L of the base member 26 There may be a step between the two. In such a case, there is a risk of liquid leakage from the joint surface of the joint structure 22 with the adjacent structure, so that it is necessary to sufficiently ensure the flatness accuracy.

  The plurality of reinforcing members 30 are at least a part of each of the adjacent two edge portions 30A and 30B so as to stand up at a predetermined distance from each other on the inner angle side formed by the non-flange surface 28A and the one surface 26A. Are respectively coupled to one surface 26A and the non-flange surface 28A.

[Sidewall]
The side wall plate 12 may be a rectangular metal plate in which the two circumferential edges 14 and 16 facing each other are short sides and the two opposing height direction edges 18 and 20 are long sides. The side wall plate 12 can be made of any material such as iron or stainless steel according to the type of liquid stored in the liquid storage tank 1 and the service life of the liquid storage tank. The shape of the side wall plate 12 may be any of a horizontally long rectangular shape, a vertically long rectangular shape, or a square shape depending on the shape of the liquid storage tank 1 and the number of side wall units 10 constituting one cylindrical member 2. it can. The thickness of the side wall plate 12, the lengths of the circumferential edges 14 and 16, and the lengths of the height edges 18 and 20 are not limited and are appropriately selected according to the size of the liquid storage tank 1. can do. The side wall plate 12 can be curved according to the curvature of the wall surface of the liquid storage tank 1 at any point before the joining structure is attached to the circumferential edges 14 and 16.

[Base member]
The base member 26 in the present embodiment can be a metal plate having two long sides 26L and two short sides 26S. The base member 26 can be made of any material such as iron or stainless steel depending on the type of liquid stored in the liquid storage tank 1 and the service life of the liquid storage tank. One of the long sides 26 </ b> L is an edge joined by welding to the circumferential edge 14 of the side wall plate 12, and therefore, the length is preferably equal to the length of the circumferential edge 14. It is preferable that the length of the short side 26 </ b> S be a length that can secure a distance that the influence of welding heat when the base member 26 and the side wall plate 12 are welded does not reach the circumferential joining flange 28 described later.

  The thickness of the base member 26 is not limited and can be appropriately selected according to the size of the liquid storage tank 1. The base member 26 is preferably thicker than the side wall plate 12. By using the base member 26 that is thicker than the side wall plate 12, the predetermined angle between the base member 26 and the circumferential joining flange 28 can be maintained more firmly. When the side wall plate and the circumferential joining flange are directly coupled as in the prior art, the angle between the side wall plate and the flange surface cannot be maintained when a high pressure of liquid is applied from the inside, so that the adjacent In some cases, the flange surfaces facing each other open from the direction corresponding to the inside of the tank, and the liquid inside leaks.

[Circumferential joining flange]
The circumferential joining flange 28 in the present embodiment can be a metal plate having two long sides 28L and two short sides 28S. The circumferential joining flange 28 can be made of any material such as iron or stainless steel depending on the type of liquid contained in the liquid storage tank 1 and the service life of the liquid storage tank. The length of the long side 28L is preferably equal to the length of the long side 26L of the base member 26. Although the thickness of the circumferential joining flange 28 and the length of the short side 28S are not particularly limited, the thickness and the length are sufficient to ensure the joining strength with the circumferential joining flange 28 of the adjacent side wall unit 10. Preferably there is.

  The circumferential joint flange 28 may be provided with a hole 32 through which a bolt, such as a nut and a bolt, for mechanically joining with the circumferential joint flange 28 of the adjacent side wall unit 10 is passed. The holes 32 do not need to be provided at regular intervals with respect to the long side direction of the circumferential joining flange 28, and can be provided at arbitrary intervals as necessary. For example, in a large-capacity liquid storage tank, an internal pressure that deforms so as to bulge outward is applied near the center of the side wall unit 10 in the height direction far from the joint portion in the height direction. Therefore, the spacing between adjacent holes 32 is intended to increase the joint strength of the corresponding portion of the circumferential joint flange 28, as shown in FIG. It is also possible to make it narrower (ie, increase the number of holes 32) as it goes from the end to the center with respect to the vertical direction. In order to further increase the joining strength of the circumferential joining flange 28, the diameter of the hole 32 is increased so that a bolt having a large diameter can be passed in addition to changing the spacing of the holes 32 or changing the spacing. May be. It is more preferable that the position of the hole 32 in the short side direction is as close to the base member as possible.

[Reinforcing member]
Each of the plurality of reinforcing members 30 can be a metal plate-like body, and as shown in FIG. 4A, a first edge portion 30A at least partially welded to one surface 26A of the base member 26. And at least a second edge 30B that intersects the first edge 30A at a predetermined angle and is welded to at least a part of the non-flange surface 28A. Therefore, a predetermined angle between the base member 26 and the circumferential joining flange 28 can be maintained by the first edge 30A and the second edge 30B. The predetermined angle is an angle that can be determined according to the diameter of the liquid storage tank 1 as described above. The lengths of the first edge 30A and the second edge 30B are not limited. The first edge 30 </ b> A preferably has at least the same length as the short side 26 </ b> S of the base member 26. In another embodiment, it is more preferable that the first edge portion 30 </ b> A is longer than the short side 26 </ b> S of the base member 26 and is also welded to the surface 12 </ b> A of the side wall plate 12. By making the first edge portion 30A to extend from one surface 26A of the base member 26 to the surface 12A of the side wall plate 12, the joint between the base member 26 and the side wall plate 12 is not deformed with respect to the internal pressure. Furthermore, the strength of the side wall plate 12 against the internal pressure can be reinforced.

  As shown in FIG. 5A, the reinforcing member 30 is further opposed to the first edge 30A and has a third edge 30C having a length corresponding to the short side 26S of the base member 26, and It may have a fourth edge 30D that faces the second edge 30B and connects one end of the first edge 30A and one end of the third edge 30C. More preferably, the length of the third edge 30C is the same length as the short side 26S of the base member. In the case of this shape, the reinforcing member 30 includes the side wall plate 12 of the first edge 30A and the quadrangle formed by the first edge 30A, the second edge 30B, and the third edge 30C. This is a shape in which a portion coupled to the surface 12A and a triangle having the four edges 30D adjacent to each other are combined. By forming the reinforcing member 30 in such a shape, the quadrangular portion plays a role of maintaining the angle between the base member 26 and the circumferential joining flange 28, and the triangular portion increases the strength against the internal pressure of the side wall plate 12. As a result, even in a large-capacity liquid storage tank having a high internal pressure, it is possible to reliably prevent leakage of liquid from a joint portion between adjacent side wall units 10.

  In the plurality of reinforcing members 30, as shown in FIG. 5B, a notch 31 may be formed at a portion corresponding to the intersection of the first edge 30 </ b> A and the second edge 30 </ b> B. More preferred. In the reinforcing member 30 having the shape without the notch 31, stress is concentrated at the intersection of the first edge 30 </ b> A and the second edge 30 </ b> B when internal pressure is applied to the joint structure 22, and the portion breaks from the portion. However, the occurrence of this problem can be prevented by providing the notch 31. In addition, when there is no notch 31, the welding of the base member 26 and the circumferential joining flange 28 is discontinuous at the intersection of the first edge 30A and the second edge 30B. By forming the notch 31, there is an advantage that both can be continuously welded.

  In the present embodiment, the first edge 30A is more preferably provided with a step in the middle as shown in FIG. 5 (a). In this embodiment, the thickness of the base member 26 is thicker than that of the side wall plate 12, and the other surface 26B of the base member 26 and the inner surface 12B of the side wall plate 12 are substantially as shown in FIG. 4A. By being joined so as to be flush with each other, there is a step between one surface 26A of the base member 26 and the outer surface 12A of the side wall plate 12, so that the reinforcing member 30 is formed corresponding to this. Because. Therefore, when used in an embodiment in which one surface 26A of the base member 26 and the outer surface 12A of the side wall plate 12 are joined so as to be substantially flush with each other, there is no need to provide a step on the first edge 30A. . In another embodiment, as shown in FIG. 5B, a portion corresponding to the step of the first edge 30A, that is, a portion corresponding to the coupling position of the side wall plate 12 and the base member 26 is used. More preferably, the notch 34 is formed. By forming the notch 34, the effect of preventing stress concentration in the stepped portion and preventing discontinuity of welding between the side wall plate 12 and the base member 26 is achieved as in the effect of the notch 31. Can bring.

  The intervals between the plurality of reinforcing members 30 are equal in the present embodiment, but are not limited thereto, and may be provided at arbitrary intervals as necessary. In another embodiment, as shown in FIG. 4C, the plurality of reinforcing members 30 have a narrower interval in the vicinity of the center in the long side direction compared to the interval in the end portion in the long side direction of the circumferential joint flange 28. Can be combined. By coupling the reinforcing members 30 at such intervals, it is possible to more effectively counter the internal pressure applied near the center in the height direction of the side wall unit 10.

2. 3. Side Wall Unit Manufacturing Method Next, the side wall unit manufacturing method according to the present invention will be described with reference to FIGS. 6 to 9, taking the side wall unit 10 shown in FIG. 3 as an example.

[Preparation of parts]
In this method, first, members constituting the side wall unit 10 are prepared. As described above, one side wall unit 10 includes at least one side wall plate 12 and two joint structures 22 and 24, and each of the joint structures 22 and 24 includes at least one base member 26. And one circumferential joining flange 26 and a plurality of reinforcing members 30. The number of reinforcing members 30 is not limited, and can be appropriately selected according to the pressure applied to the inner wall of the liquid storage tank 1. The number of the side wall units 10 used in the liquid storage tank 1 is appropriately selected according to the size, application, internal pressure, etc. of the liquid storage tank 1, and is a member prepared for manufacturing one liquid storage tank 1, that is, The number of the side wall plate 12, the base member 26, the circumferential joint flange 28, and the reinforcing member 30 varies depending on the number of the side wall units 10 used. For example, as shown in FIG. 1, when the liquid storage tank 10 is configured using four cylindrical members 2, and one cylindrical member 2 is configured using four side wall units 10, it is used. The number of side wall units 10 to be used is sixteen.

(1) 1st Embodiment (manufacturing process without temporary assembly)
The manufacturing method according to the first embodiment of the present invention may include a first joint structure forming step, a first strain removing step, a second joint structure forming step, and a sidewall unit assembly step. Moreover, a 3rd distortion removal process and / or an auxiliary | assistant distortion removal process can be included as needed. Unlike the manufacturing method according to the second embodiment described later, the manufacturing method according to the first embodiment is a method of forming a bonded structure without temporarily assembling the bonded structures.

[First bonded structure forming step]
The first bonded structure forming step is a step of forming the bonded structure 22 or 24. Here, the joining structure 22 shown in FIG. 4A will be described as a first joining structure. In this step, first, the non-flange surface 28A, which is the surface opposite to the flange surface 28B of the circumferential joining flange 28, and one end surface of the two long sides 26L of the base member 26 are aligned. The respective members are arranged at predetermined positions. At this time, the one surface 26A of the base member 26 and the non-flange surface 28A are arranged so as to intersect at a predetermined angle. Further, a plurality of reinforcing members 30 are arranged at predetermined intervals on the inner corner formed by the one surface 26A and the non-flange surface 28A. The plurality of reinforcing members 30 are preferably arranged such that the main surface of the reinforcing member 30 is orthogonal to both the surface 26A and the surface 28A. The positional relationship between the long side 28L of the circumferential joining flange 28 and the long side 26L of the base member 26 can be substantially parallel.

  Next, between the long side 26 </ b> L of the base member 26 and the non-flange surface 28 </ b> A, between the surface 26 </ b> A and at least a part of the first edge 30 </ b> A of the reinforcing member 30, and between the surface 28 </ b> A and the second of the reinforcing member 30. All of the edges 30B are joined to each other by welding. The connection here is different from the temporary connection used in the second embodiment to be described later, and the base member 26, the circumferential joining flange 28 and the plurality of reinforcing members 30 are assembled together as a liquid storage tank. Sometimes welding with sufficient strength to ensure resistance to internal pressure. In this specification, this may be called this coupling | bonding.

  Generally, the welded portion undergoes thermal shrinkage of the material when the welded portion is cooled. Therefore, when the surface 26A side of the long side 26L and the surface 28A are welded, the inner angle formed by the surface 26A and the surface 28A with respect to the base member 26 and the circumferential joining flange 28 is smaller than a predetermined angle. The force which acts as will be added. However, in the present invention, the reinforcing member 30 whose angle between the first edge 30A and the second edge 30B is a predetermined angle is raised between the surface 26A and the surface 28A in advance. This allows the angle between these surfaces to be maintained against shrinkage during cooling of the welding heat.

  The order of coupling among the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 is not particularly limited. In one embodiment, the base member 26, the circumferential joining flange 28 and the plurality of reinforcing members 30 are joined by first joining the circumferential joining flange 28 and each of the plurality of reinforcing members 30, and then the circumferential joining flange 28. And the base member 26, and finally the step of joining the plurality of reinforcing members and the base member 26 can be performed in this order. In another embodiment, the base member 26, the circumferential joining flange 28 and the plurality of reinforcing members 30 are joined by first joining the base member 26 and the circumferential joining flange 28 and then each of the plurality of reinforcing members 30. The steps of joining the base member 26 and the circumferential joining flange 28 can be performed in this order. From the viewpoint of minimizing the occurrence of distortion due to welding heat, the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 are joined from the joining portion near the center in the long side direction of the circumferential joining flange 28 to the long side It is more preferable that the steps are sequentially performed toward the joining portion at the direction end.

[First distortion removing step]
In the method for manufacturing the side wall unit according to the present invention, it is most important to remove the distortion of the joint structure so as to withstand the high internal pressure of the liquid storage tank to which the side wall unit is joined. For this purpose, the method includes a step of removing distortion of the joint structure caused by welding during the manufacturing process of the side wall unit. FIG. 6 shows a first distortion step for removing the distortion of the created bonded structure 22.

  The shrinkage amount of the member to be welded due to welding heat increases as the welding amount increases. Therefore, the joining structure 22 is formed on the side of the one surface 26A of the base member 26 due to the effect of welding between the base member 26 and the circumferential joining flange 28 and welding heat between the circumferential joining flange 28 and the plurality of reinforcing members 30. As shown in FIG. 6A when viewed from above, the center portion in the long side (28L) direction of the circumferential joining flange 28 is distorted so as to protrude toward the non-flange surface 28A. It should be noted that FIG. 6A is exaggerated in the amount of protrusion for explaining the process of the present invention. The same applies to FIG. 7A described later.

  Therefore, in the first strain removal step, the bonding structure 22 is mutually opposite in the longitudinal direction both ends and the longitudinal center part as shown by the arrows in FIG. By applying a force in the opposite direction, the distortion of the bonded structure 22 can be removed. The force applied to the central portion in the longitudinal direction is a force directed from the non-flange surface 28A to the flange surface 28B, and the force applied to both ends in the longitudinal direction is a force directed from the flange surface 28B to the non-flange surface 28A. it can. Specifically, in the first distortion removing step, for example, both ends in the long side direction of the flange surface 28B of the joint structure 22 are held by a locking tool, and the base member 26 is placed near the center of the long side 26L, for example, This can be realized by applying a force toward the flange surface 28B using a hydraulic jack or the like. In this way, as shown in FIG. 6B, it is possible to obtain the joint structure 22 in which the flange surface 28B is not distorted, that is, the flange surface 28B is accurately flat. This strain removing process is substantially impossible after the joining structure 22 and the side wall plate 12 are joined, and thus is performed before the joining structure 22 and the side wall plate 12 are joined. It will be.

  In FIG. 6, the force is applied in a direction perpendicular to the non-flange surface 28 </ b> A and the flange surface 28 </ b> B, but the direction in which the force is applied is not limited to this. Depending on the state of distortion of the bonded structure 22, for example, a force may be applied in a direction at an appropriate angle from a direction perpendicular to the non-flange surface 28A and / or the flange surface 28B.

[Third strain removing step]
FIG. 7 shows a third strain removing process for removing strain in another direction of the created bonded structure 22. As shown in FIG. 7A when the joining structure 22 is viewed from the non-flange surface 28A side of the circumferential joining flange 28 due to the shrinkage caused by the welding heat as described above, The long side (26L) direction center part may be distorted so that it may protrude to the circumferential direction joining flange 28 side.

  Therefore, in the third strain removing step, as shown by the arrows in FIG. 7A, the longitudinal direction both ends and the longitudinal direction center of the joined structure 22 with respect to the joined structure 22. By applying forces in directions opposite to each other, the distortion of the bonded structure 22 can be removed. The force applied to the central portion in the longitudinal direction is a force applied from one surface 26A of the base member 26 toward the other surface 26B, which is the surface opposite to the one surface 26A, and is applied to both ends in the longitudinal direction. Can be a force from the other surface 26B toward the one surface 26A. Specifically, for example, the third strain removing step is performed by, for example, holding both ends in the long side direction of the other surface 26B of the base member 26 of the joining structure 22 with a locking tool, and by moving the long side of the circumferential joining flange 28 This can be realized by applying a force in the direction of the other surface 26B using a hydraulic jack or the like near the center of 28L. In this way, as shown in FIG. 7B, it is possible to obtain the joint structure 22 in which the other surface 26B of the base member 26 is not distorted, that is, the other surface 26B is exactly flat.

  In FIG. 7, the force is shown to be applied in a direction perpendicular to the one surface 26 </ b> A and the other surface 26 </ b> B of the base member 26, but the direction in which the force is applied is not limited to this. Depending on the state of distortion of the bonded structure 22, for example, a force may be applied in a direction at an appropriate angle from a direction perpendicular to the one surface 26A and / or the other surface 26B.

  Note that when considering only the viewpoint of preventing liquid leakage in the large-capacity liquid storage tank 1, the third distortion removing step is not necessarily performed. That is, the occurrence of liquid leakage in the large-capacity liquid storage tank 1 is generally a problem when the flange surface 28B of the circumferential joining flange 28 is not accurately flat. Therefore, if the flange surface 28B is flat, even if the joint structure 22 is distorted so as to protrude in a direction perpendicular to the one surface 26A or the other surface 26B of the base member 26, for example, This is not a problem for liquid leakage from the large-capacity liquid storage tank 1. Therefore, the third distortion removing step can be omitted.

[Second bonded structure forming step]
Next, the second bonded structure can be formed by the same process as the first bonded structure forming process, the first strain removing process, and, if necessary, the third strain removing process. Here, the joined structure 24 shown in FIG. 3 is a second joined structure.

[Bending side wall plate]
The side wall plate 12 can be curved so as to have a predetermined curvature according to the number of the side wall units 10 used for manufacturing the liquid storage tank 1. When the side wall plate 12 is used, for example, in the cylindrical member stacking type liquid storage tank 1 shown in FIG. 1, the side plate 12 is bent so that the long side becomes an arc shape, for example, a single cylindrical shape shown in FIG. 2. When used in the member-type liquid storage tank 1 ′, it can be curved so that the short side is arcuate. A method known to those skilled in the art can be used as a method of bending the side wall plate 12.

[Sidewall unit assembly process]
Next, in the side wall unit assembling step, the side wall plate 12 and the first joint structure 22 and the second joint structure 24 can be coupled. In the side wall unit assembling step, one of the opposed circumferential edges 14 and 16 of the curved side wall plate 12 and the long side 26L of the base member 26 of the first joint structure 22 are joined by welding to form a circumferential edge. The other side 16 of the part and the long side 26L of the base member 26 of the second joint structure 24 are joined by welding. From the viewpoint of resistance to the internal pressure of the liquid storage tank 1, the connection between the circumferential edges 14 and 16 of the side wall plate 12 and the joining structures 22 and 24, as described above, is the other surface 26 </ b> B of the base member 26. The surface facing the inside of the liquid storage tank 1 and the surface 12B facing the inside of the liquid storage tank 1 in the side wall plate 12 are preferably joined so as to be substantially flush with each other.

[Auxiliary distortion removal process]
In the side wall unit according to the present invention, for example, the length of the short side 26S of the base member 26 in the joint structure 22 shown in FIG. 4A is the same as that of the long side 26L of the base member 26 of the joint structure 22 and the side wall plate 12. It is preferable that the length is such that the heat at the time of welding the circumferential edge portion 14 is not transmitted to the circumferential joining flange 28. This is because if the heat at the time of welding is transmitted to the circumferential joining flange 28, the flange surface 28B of the circumferential joining flange 28 may be distorted. However, in practice, it may be unavoidable that heat at the time of welding is transferred to the circumferential joining flange 28. In this case, the side wall unit 10 after the side wall plate 12 and the joined structure are joined together. In this case, distortion may remain in the circumferential joining flange 28. Even when the distortion due to the coupling between the side wall plate and the bonded structure does not occur, the distortion in the process before the coupling may not be completely removed.

  In one embodiment of the present invention, the side wall unit manufacturing method may include an auxiliary distortion removing step for removing these distortions. This step can be either one or both of the first strain removal step and the third strain removal step described above, depending on the state of the strain generated in the bonded structure.

(2) Second embodiment (manufacturing process with provisional assembly)
The manufacturing method according to the second embodiment of the present invention may include a first strain removal and first joining structure forming step, a second joining structure forming step, and a side wall unit assembly step. In addition, a second distortion removing process, a third distortion removing process, and / or an auxiliary distortion removing process may be included as necessary. In the manufacturing method according to the second embodiment, unlike the manufacturing method according to the first embodiment, an intermediate body in which the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 are temporarily coupled to each other is created. After temporarily assembling and constraining one of the intermediate bodies, the respective members are coupled (this can also be referred to as main coupling for the temporary coupling). The members of the intermediate body are welded together while the two intermediate bodies are constrained, and the welded portion is cooled as it is, so that distortion generated during cooling is suppressed by the constrained state, and as a result, the distortion is removed. A bonded structure can be manufactured.

[First Strain Removal and First Bonding Structure Forming Step]
The first strain removal and first bonding structure forming step is a step of forming the first bonding structure while removing the strain. Here, the joined structure 22 shown in FIG. 4A is the first joined structure, and the intermediates in the process are the first intermediate 22 ′ and the second intermediate 22 ″. FIG. 8 shows the first intermediate. FIG. 9 shows a state in which the first intermediate body 22 ′ and the second intermediate body 22 ″ are temporarily assembled and restrained.

  In this step, as in the first embodiment, first, the non-flange surface 28A, which is the surface opposite to the flange surface 28B of the circumferential joint flange 28, and the two long sides 26L of the base member 26 are used. Each member is arranged at a predetermined position so that one of the end faces is aligned. At this time, the one surface 26A of the base member 26 and the non-flange surface 28A are arranged so as to intersect at a predetermined angle. Further, a plurality of reinforcing members 30 are arranged at predetermined intervals on the inner corner formed by the one surface 26A and the non-flange surface 28A. The plurality of reinforcing members 30 are preferably arranged such that the main surface of the reinforcing member 30 is orthogonal to both the surface 26A and the surface 28A. The positional relationship between the long side 28L of the circumferential joining flange 28 and the long side 26L of the base member 26 can be substantially parallel.

  Next, between the long side 26L of the base member 26 and the non-flange surface 28A, between the surface 26A and the first edge 30A of the reinforcing member 30, and between the surface 28A and the second edge 30B of the reinforcing member 30 As shown in FIG. 8, both are temporarily joined by welding. Here, the temporary coupling means that the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 are arranged so as to have a desired positional relationship with each other, but maintain the positional relationship with each other. A state where welding is performed with a sufficient minimum strength. Temporary joining can be realized by performing welding having a length of about 2 cm, for example, at a place to be joined. In this way, the first intermediate 22 'shown in FIG. 8 is formed.

  The order of temporary coupling among the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 is not particularly limited. In one embodiment, the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 are temporarily joined by first temporarily joining the circumferential joining flange 28 and each of the plurality of reinforcing members 30, and then circumferential joining. The steps of temporarily joining the flange 28 and the base member 26 and finally temporarily joining the plurality of reinforcing members and the base member 26 can be performed in this order. In another embodiment, the base member 26, the circumferential joining flange 28 and the plurality of reinforcing members 30 are temporarily joined by first temporarily joining the base member 26 and the circumferential joining flange 28, and then the plurality of reinforcing members 30. The steps of temporarily joining the base member 26 and the circumferential joining flange 28 to each other can be performed in this order. From the viewpoint of minimizing the occurrence of distortion due to welding heat, the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 are temporarily joined to the central portion with respect to the direction of the long side 28L of the circumferential joining flange 28. It is more preferable that the steps are sequentially performed from a nearby joint location toward a joint location in the short side 28S direction.

  Next, the second intermediate 22 ″ is formed by the same process as the formation of the first intermediate 22 ′. In the present embodiment, the second intermediate 22 ″ is finally formed with the bonding structure 24. Is described on the assumption that it is a separate joint structure. In another embodiment, the intermediate body that becomes the joint structure 24 may be the intermediate body 22 ″. In still another embodiment, when the liquid storage tank 1 is assembled, the joint structure body 22 and the circumferential joint flange are used. The intermediate body which becomes the mating bonded structure of the other party through the intermediate body 22 ″ may be used as the intermediate body 22 ″.

  Next, as shown in FIG. 9, the formed first intermediate body 22 ′ and second intermediate body 22 ″ are constrained by being temporarily assembled via the flange surface 28 </ b> B of the circumferential joining flange 28. Can be performed by joining the first intermediate body 22 ′ and the second intermediate body 22 ″ using a mechanical fastener.

  Next, at least in the first intermediate body 22 ′, the base member 26, the circumferential joining flange 28, and each of the plurality of reinforcing members 30 are coupled to each other (that is, main coupling). As already mentioned, the parts to be joined by welding undergo material shrinkage. When the respective members are joined in a state of one joining structure alone without being temporarily assembled and restrained as in the first embodiment, the circumferential joining flange as shown in FIG. Distortion occurs so that the central part in the long side direction of 28 protrudes toward the non-flange surface 28A. In the first embodiment, after the first bonded structure is formed, the generated distortion can be removed by applying the force indicated by the arrow in FIG. 6A to the first bonded structure. On the other hand, in the second embodiment, the force indicated by the arrow in FIG. 6A is obtained by connecting (mainly connecting) the intermediate body 22 ′ and the intermediate body 22 ″ in a constrained state. The members are welded together and then cooled in a state where they are always applied to both the first intermediate 22 ′ and the second intermediate 22 ″. Distortion of the circumferential joint flange generally occurs during cooling, but the two intermediates are constrained even during cooling. As a result, distortion is eliminated (or the generation of distortion is suppressed). The first bonded structure can be formed.

  Similarly to the first embodiment, when the surface 26A side of the long side 26L and the surface 28A are welded, the surface 26A and the surface 28A are formed with respect to the base member 26 and the circumferential joining flange 28. A force acting so that the inner angle becomes smaller than a predetermined angle is applied. However, in the present invention, the reinforcing member 30 having the predetermined angle between the first edge 30A and the second edge 30B stands between the surface 26A and the surface 28A. Thereby maintaining the angle between these faces against shrinkage during cooling of the welding heat.

  Furthermore, as in the first embodiment, the order of coupling (main coupling) among the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 is not particularly limited. In one embodiment, the base member 26, the circumferential joining flange 28 and the plurality of reinforcing members 30 are joined by first joining the circumferential joining flange 28 and each of the plurality of reinforcing members 30, and then the circumferential joining flange 28. And the base member 26, and finally the step of joining the plurality of reinforcing members and the base member 26 can be performed in this order. In another embodiment, the base member 26, the circumferential joining flange 28 and the plurality of reinforcing members 30 are joined by first joining the base member 26 and the circumferential joining flange 28 and then each of the plurality of reinforcing members 30. The steps of joining the base member 26 and the circumferential joining flange 28 can be performed in this order. From the viewpoint of minimizing the occurrence of distortion due to heat, the base member 26, the circumferential joining flange 28, and the plurality of reinforcing members 30 are coupled in the vicinity of the central portion with respect to the direction of the long side 28 </ b> L of the circumferential joining flange 28. It is more preferable that the steps are sequentially performed from the joining portion toward the joining portion in the direction of the short side 28S.

  Finally, in the first intermediate body 22 ′ and the second intermediate body 22 ″ in the temporarily assembled state, by releasing the temporary assembly by releasing the restraint by the mechanical fastener, the first intermediate body 22 ′ Thus, the first bonded structure 22 is obtained.

[Second distortion removing step]
In the above-described first strain removal and first joint structure forming step, while removing the strain in which the vicinity of the center in the long side direction of the circumferential joint flange 28 protrudes toward the non-flange surface 28A at the time of joining the members, The first bonding structure 22 can be formed. However, there are cases where the distortion of the first bonded structure cannot be removed only by this process. In such a case, the force directed from the non-flange surface 28A to the flange surface 28B and the flange surface 28B to the non-flange surface 28A are applied to the longitudinal central portion and both longitudinal ends of the first joint structure 22, respectively. The second strain removing step of further removing the strain of the first joint structure can be performed by simultaneously applying a force directed in the direction of. The second distortion removal step can be performed by the same method as the first distortion removal step in the first embodiment.

  In the formed first joint structure 22, distortion occurs so that, for example, the vicinity of the center in the long side direction of the circumferential joint flange 28 protrudes toward the flange surface 28 </ b> B in accordance with the welding state during temporary assembly. Sometimes it is. In this case, the second strain removing step includes a force directed from the flange surface 28B toward the non-flange surface 28A with respect to the longitudinal center portion and both longitudinal end portions of the first joint structure 22, respectively. It is good also as a process of removing further distortion of the 1st joined structure by applying simultaneously the force which goes to the direction of non-flange surface 28A from flange surface 28B.

[Third strain removing step]
FIG. 7 shows the first joint structure 22 in the second embodiment when viewed from the non-flange surface 28A side of the circumferential joint flange 28 after the first strain removal and first joint structure forming step. As shown in (a), the distortion that has occurred so that the central portion of the long side direction of the base member 26 protrudes toward the circumferential joining flange 28 is not removed. Therefore, when such a distortion occurs, a third distortion removing step can be further performed. The third distortion removal step can be performed by the same method as the third distortion removal step in the first embodiment.

[Second bonded structure forming step]
Next, the second bonded structure is obtained by the same process as the above-described first strain removing and first bonded structure forming process (the second strain removing process and the third strain removing process may be performed if necessary). Can be formed. Here, the joined structure 24 shown in FIG. 3 is a second joined structure.

[Other processes]
Next, as in the first embodiment, the side wall plate 12 is curved, and the side wall plate 12 is coupled to the first bonding structure 22 and the second bonding structure 24, and auxiliary strain removal is performed as necessary. By going through the steps, the side wall unit 10 is formed.

3. Manufacture of liquid storage tank The liquid storage tank 1 can be manufactured using the plurality of side wall units 10 manufactured by the manufacturing method according to the present invention and / or the plurality of side wall units 10 having the structure according to the present invention. it can. A liquid storage tank 1 shown in FIG. 1 is formed by stacking and joining cylindrical members 2 formed by joining a plurality of side wall units 10 in a circumferential direction on a separately prepared bottom wall 3 (not shown). Further, it can be manufactured by sequentially stacking the necessary number of cylindrical members 2 similarly formed thereon and joining them together. Further, the liquid storage tank 1 ′ shown in FIG. 2 has a tubular member 2 ′ formed by joining a plurality of side wall units 10 ′ in the circumferential direction on a separately prepared bottom wall 3 ′ (not shown). It can be manufactured by forming. Although not shown, the liquid storage tank 1 or 1 ′ may be provided with a stairway portion where a human can walk and a ladder for climbing the corridor portion. This corridor can also be used as a temporary scaffold during assembly of the liquid storage tank. Below, manufacture of the liquid storage tank 1 shown by FIG. 1 is demonstrated.

  In the case where the cylindrical member 2 obtained by joining a plurality of side wall units 10 in the circumferential direction is stacked to form the liquid storage tank 1, the positions of the joining structures 22 and 24 of each side wall unit 10 are as shown in FIG. Moreover, it is preferable that the cylindrical members 2 are stacked so as to be staggered in the height direction. For example, when four side wall units 10 are used in one cylindrical member 2 as in the liquid storage tank 1 of FIG. 1, the second-stage cylindrical member 2 is the first-stage cylindrical member from the bottom. The third cylindrical member 2 is stacked in a state of being rotated by 45 degrees with respect to the member 2 at a plane angle, and the third-stage tubular member 2 is rotated at a flat angle of 45 degrees with respect to the second-stage tubular member 2. It is preferable to stack. The same applies to the fourth stage relative to the third-stage tubular member 2. Thus, the liquid storage tank 1 having a well-balanced structure can be obtained by stacking the cylindrical members 2 so that the joined portions of the joined structure do not concentrate in a line in the height direction.

[Bottom wall]
The bottom wall 3 used in the liquid storage tank 1 is not particularly limited in terms of structure, thickness, material, etc., and when used in the large-capacity liquid storage tank 1, the internal liquid does not leak. Any structure, thickness, material, etc. can be accommodated. In one embodiment, the bottom wall 3 is manufactured in advance as a plurality of units of a predetermined size suitable for transport in a manufacturing factory or the like, and the plurality of manufactured units are transported to the installation site by a vehicle, for example, bolts And preferably assembled using mechanical fasteners such as nuts. A joint portion for joining the cylindrical member 2 can be provided on the outermost periphery of the bottom wall.

[Mechanical fasteners]
One cylindrical member 2 is formed by facing the flange surfaces 28B of the circumferential joining flanges 28 in the joining structure of the adjacent side wall units 10 and joining each other using, for example, a mechanical fastener. Joining between adjacent joint structures may be performed by providing a hole 32 in the circumferential joint flange 28 in each joint structure, passing a bolt through the provided hole 32, and fastening the bolt with a nut. preferable.

  In the liquid storage tank 1, the internal pressure applied to the wall surface generally increases as the tank is located below. Therefore, it is preferable that the lower tubular member 2 has a higher strength for joining adjacent joint structures than the upper tubular member 2. As a method for realizing this, one or both of the following two methods can be mainly employed. One is a method in which the lower cylindrical member 2 uses a mechanical fastener whose strength is higher, and the other is a method in which the lower cylindrical member 2 uses a larger number of mechanical fasteners. Is the method.

  In the former case, the bonding strength can be increased by increasing the diameter of the bolt used as the mechanical fastener. Therefore, in this case, it is preferable that the size of the hole 32 provided in the circumferential joining flange 28 of the side wall unit 10 is larger as it is used below the liquid storage tank 1. Alternatively, a fastener made of a material having higher mechanical strength can be used for the lower cylindrical member 2.

  On the other hand, in the latter case, it is preferable that the number of holes 32 provided in the circumferential joining flange 28 of the side wall unit 10 increases as the number of holes 32 used below the liquid storage tank 1 increases. In this case, in the liquid storage tank 1 manufactured by stacking the cylindrical members 2 in the height direction, it is preferable to increase the number of the reinforcing members 30 in the lower side wall unit 10.

[Seal layer]
When the flange surfaces 28B of the circumferential joining flanges 28 in the adjacent side wall units 10 face each other and are joined to each other, a seal layer for preventing leakage of the internal liquid is disposed between the facing flange surfaces 28B. It is more preferable. The seal layer is preferably, but not limited to, a water-expandable elastic seal layer. On the flange surface 28, either the region corresponding to the inside of the tank or the region corresponding to the outside of the tank with the hole 32 interposed therebetween. It can be placed on one or both. Further, on the flange surface 28, another seal layer such as a silicone seal layer may be further disposed in one or both of a region corresponding to the inside of the tank and a region corresponding to the outside of the tank with the seal layer interposed therebetween. .

  For the purpose of obtaining a more reliable effect of preventing liquid leakage, for example, as shown in FIG. 10, grooves 40 and / or 41 for arranging a seal layer are provided on the flange surface 28 </ b> B of the circumferential joint flange 28. You can also By disposing the seal layer inside the grooves 40 and 41 thus provided, there is an advantage that the seal layer does not collapse even when the adjacent circumferential joining flanges 28 are strongly joined to each other. If the seal layer is disposed on the flange surface 28B without providing the grooves 40 and 41, the seal layer may be crushed when the circumferential joining flange 28 is strongly joined, and the effect of preventing liquid leakage may be reduced. Further, as another advantage, by providing the grooves 40 and 41 for disposing the seal layer, it is possible to avoid the positional deviation of the seal layer when assembling the liquid storage tank, and the adjacent periphery. The effect that alignment of the direction joining flange 28 can be performed more easily is also acquired.

[Height direction flange]
In the case of the liquid storage tank 1 manufactured by stacking a plurality of cylindrical members 2 obtained by joining a plurality of side wall units 10 in the circumferential direction in the height direction, the opposing height of each side wall unit 10 is It is possible to stack the tubular member 2 by providing a height direction joining flange at the lengthwise end and joining the opposing flange surfaces of adjacent height direction joining flanges using, for example, a mechanical fastener. it can. When the cylindrical member 2 is stacked in the height direction, the flange surface is closed by the weight of the cylindrical member 2, but the force of closing the flange surface by the weight of the cylindrical member 2 is much larger than the water pressure. Therefore, it is sufficient for the height direction joining flange to use a joining flange having a normal form in the prior art. The joint flange for this purpose can be formed by welding a metal plate so as to stand vertically from the side wall unit 10 over the entire length of the end portion in the height direction of the side wall unit 10.

  However, for the purpose of further increasing the joining strength in the height direction, as shown in FIG. 11, it is more preferable to use an angle steel material having an L-shaped cross section (also referred to as an angle steel material) as the height direction joining flange. This is mainly due to the following reasons. First, in the height direction joining flange 50 made of angle steel, one plate portion 51 is welded to the side wall unit 10 over the entire two opposing long sides of the plate portion 51. Therefore, the joint portion between the height direction joining flange 50 and the side wall unit 10 is divided into two portions (that is, the joint portion between the two long sides and the unit), and stress can be dispersed. There is an advantage that the welding heat of the height direction joining flange 50 is difficult to be transmitted to the flange itself. On the other hand, in the case of the height direction joint flange in which the plate-like body is welded to the side wall unit 10, since the joint portion is located at one place or a close place, the stress is easily concentrated, and the welding heat is generated by the flange. There is a drawback in that there is a possibility of generating distortion by transmitting to the.

  Secondly, the height direction joining flange 50 made of angle steel can maintain the same strength even if the thickness of the plate portion 52 of the flange surface is made thinner than the joining flange of the plate-like body. Thus, the height direction joining flange 50 with a thin flange surface can further improve the adhesion when the opposing flange surfaces are joined using a mechanical fastener. On the other hand, in the case of a plate-like joined flange, the thickness of the flange surface is increased, and therefore it is difficult to improve the adhesion when joined using a mechanical fastener.

  Although not shown in FIG. 11, it is more preferable to provide a seal layer for preventing liquid leakage also on the flange surface 52 of the height direction joining flange 50. The details of the kind of the sealing layer, the arrangement method, the position, and the like are the same as those of the circumferential joining flange 28. Also, the flange surface 52 may be provided with a groove for disposing a seal layer, similarly to the flange surface 28B of the circumferential joining flange 28.

1, 1 'Liquid storage tank 2, 2' Cylindrical member 10, 10 'Side wall unit 12 Side wall plate 14, 16 Circumferential edge 18, 20 Height direction edge 22, 24 Joint structure 22', 22 "intermediate Body 26 Base member 28 Circumferential joining flange 30 Reinforcing member 32 Hole 40, 41 Groove 50 Height joining flange

Claims (27)

At least a bottom wall and a side wall constituted by one cylindrical member or a side wall constituted by stacking a plurality of cylindrical members in the height direction, wherein at least one of the cylindrical members is a plurality of side walls. A method of manufacturing the side wall unit used in the manufacture of a liquid storage tank constituted by joining units in the circumferential direction,
(A) A step of preparing a member constituting the side wall unit,
A rectangular side wall plate;
A base member having a long side and a short side, a circumferential joint flange having a long side and a short side, included in a joint structure attached to each of two opposing circumferential edges of the side wall plate, and A plurality of reinforcing members having two adjacent edges intersecting at a predetermined angle;
A preparation process to prepare,
(B) A long side of the circumferential joint flange and the base so that a non-flange surface opposite to the flange surface of the circumferential joint flange and one surface of the base member intersect at the predetermined angle. The circumferential reinforcing flange and the base member are coupled in a positional relationship in which the long sides of the member are parallel to each other, and the plurality of reinforcing members are formed on the inner angle side formed by the non-flange surface and the one surface. The first joining structure is formed by joining at least a part of each of the two adjacent edges to the non-flange surface and the one surface so that each of the two adjacent edges rises from each other. A first bonded structure forming step;
(C) With respect to the first joint structure, a force and a flange directed from the non-flange surface toward the flange surface respectively at a longitudinal center portion and both longitudinal end portions of the first joint structure A first strain removing step of removing strain of the first joint structure by simultaneously applying a force from a surface toward the non-flange surface;
(D) a second bonding structure forming step of forming a second bonding structure by the same steps as (A) to (C);
(E) One of the opposing circumferential edges of the curved side wall plate is coupled to the long side of the base member of the first joint structure, and the other circumferential edge is joined to the second joint. A side wall unit assembling step for joining the long side of the base member of the structure;
The manufacturing method of the side wall unit characterized by including. At least a bottom wall and a side wall constituted by one cylindrical member or a side wall constituted by stacking a plurality of cylindrical members in the height direction, wherein at least one of the cylindrical members is a plurality of side walls. A method of manufacturing the side wall unit used in the manufacture of a liquid storage tank constituted by joining units in the circumferential direction,
(A) A step of preparing a member constituting the side wall unit,
A rectangular side wall plate;
A base member having a long side and a short side, a circumferential joint flange having a long side and a short side, included in a joint structure attached to each of two opposing circumferential edges of the side wall plate, and A plurality of reinforcing members having two adjacent edges intersecting at a predetermined angle;
A preparation process to prepare,
(B) a first strain removing and first joined body forming step of forming a first joined structure while removing strain;
The long side of the circumferential joining flange and the length of the base member are such that the non-flange surface opposite to the flange surface of the circumferential joining flange and one surface of the base member intersect at the predetermined angle. The circumferential joining flange and the base member are temporarily joined in a positional relationship in which the sides are parallel to each other, and the plurality of reinforcing members are mutually connected to an inner corner formed by the non-flange surface and the one surface. A first intermediate body by temporarily joining at least a part of each of the two adjacent edges to the non-flange surface and the one surface so as to stand up at a distance from each other,
Creating a second intermediate by the same step as the step of producing the first intermediate,
In a state where the first intermediate body and the second intermediate body are temporarily assembled and restrained via the flange surfaces, at least the circumferential joint flange, the base member, and the plurality of the first intermediate body Connecting each of the reinforcing members to each other;
Releasing the temporary assembly of the first intermediate and the second intermediate to obtain the first bonded structure;
A first strain removal and first bonding structure forming step;
(C) a second bonded structure forming step of forming a second bonded structure by the same process as (A) to (B);
(D) The long side of the base member of the first joint structure is coupled to one of the opposed circumferential edges of the curved side wall plate, and the second joint structure is coupled to the other circumferential edge. A side wall unit assembly step for joining the long sides of the base member of the body;
The manufacturing method of the side wall unit characterized by including.   The method of claim 2, wherein the second bonding structure is formed from the second intermediate.   After the first strain removal and the first bonded structure forming step, the non-flange surface is respectively formed in the longitudinal center portion and both longitudinal ends of the first bonded structure with respect to the first bonded structure. A second strain removing step of removing strain of the first joint structure by simultaneously applying a force directed from the flange surface toward the flange surface and a force directed from the flange surface toward the non-flange surface. The method according to claim 2, wherein:   The other side of the base member opposite to the one surface from the one surface of the base member to the longitudinal central portion and both longitudinal ends of the first joint structure, respectively, with respect to the first joint structure It further includes a third strain removing step of removing strain of the first joint structure by simultaneously applying a force directed to the surface and a force directed from the other surface toward the one surface. 5. A method according to any one of claims 1 to 4, characterized in that:   The coupling and / or the temporary coupling of the circumferential joining flange, the base member, and the plurality of reinforcing members couples the circumferential joining flange and each of the plurality of reinforcing members, and the circumferential joining flange, The method according to any one of claims 1 to 5, wherein the steps of joining the base member and joining the plurality of reinforcing members and the base member are performed in this order. .   The coupling and / or the temporary coupling of the circumferential joining flange, the base member, and the plurality of reinforcing members couples the circumferential joining flange and the base member, and each of the plurality of reinforcing members and the circumference. The method according to any one of claims 1 to 5, wherein the steps of joining the direction joining flange and the base member are performed in this order.   The coupling and / or the temporary coupling of the circumferential joining flange, the base member, and the plurality of reinforcing members is performed in a short side direction from a coupling location near a central portion with respect to a long side direction of the circumferential joining flange. 6. A method according to any one of claims 1 to 5, characterized in that it is carried out sequentially towards the joining point.   The plurality of reinforcing members are coupled to each other by narrowing the interval at the central portion in the long side direction compared to the interval at the end portion in the long side direction of the circumferential joint flange. 6. The method according to any one of 5 above. The plurality of reinforcing members are plate-like bodies,
A first edge that is longer than the short side of the base member and is coupled to the base member and the sidewall plate;
A second edge that intersects the first edge at the predetermined angle and is coupled to the non-flange surface;
A third edge facing the first edge and having a length corresponding to the short side of the base member;
A fourth edge facing the second edge and connecting one end of the first edge and one end of the third edge;
The method according to any one of claims 1 to 5, characterized by comprising:   In the plurality of reinforcing members, a step of forming a notch at a portion corresponding to an intersection of the first edge and the second edge, and the base member and the side wall plate at the first edge The method according to claim 10, further comprising one or both of forming a notch in a portion corresponding to a position where the first and second portions are coupled to each other.   The said base member is couple | bonded with the said circumferential joining flange so that it may stand up from parts other than the short side direction edge part of the non-flange surface of the said circumferential joining flange. The method of any one of these.   6. The method according to claim 1, further comprising forming a plurality of holes for passing a mechanical fastener over a long side direction of the circumferential joining flange. Method.   The method according to claim 13, wherein the plurality of holes are formed so that a diameter in a central portion in the long side direction is larger than a diameter in a long side end portion of the circumferential joining flange.   The method according to any one of claims 1 to 5, further comprising forming a groove for inserting a seal layer in the flange surface of the circumferential joining flange.   The method according to any one of claims 1 to 5, further comprising the step of joining a height joining flange having an L-shaped cross section to two opposing height ends. . At least a bottom wall and a side wall constituted by one cylindrical member or a side wall constituted by stacking a plurality of cylindrical members in the height direction, wherein at least one of the cylindrical members is a plurality of side walls. A side wall unit constituting the tubular member used in a liquid storage tank constituted by joining units in the circumferential direction,
A curved rectangular side wall plate;
A pair of joined structures attached to each of two opposing circumferential edges of the side wall plate;
With
Each of the pair of joined structures is
A base member having a short side and a long side;
A circumferential joining flange having a short side and a long side;
A plurality of reinforcing members having two adjacent edges intersecting at a predetermined angle;
Including
The circumferential joint flange and the base member are arranged so that the non-flange surface opposite to the flange surface of the circumferential joint flange and one surface of the base member intersect at the predetermined angle. In a positional relationship in which the long side of the direction joining flange and the long side of the base member are parallel to each other,
Each of the adjacent two edge portions is spaced apart from the non-flange surface and the one of the plurality of reinforcing members so as to stand up at an interval from each other on an inner corner formed by the non-flange surface and the one surface. Connected to one side,
Long sides of the base member in each of the pair of joined structures are coupled to each of the circumferential edge portions of the side wall plate facing each other,
A side wall unit characterized by that.   18. The side wall according to claim 17, wherein the interval between the plurality of reinforcing members is narrower in a central portion in the long side direction than in a long side direction end portion of the circumferential joining flange. unit. The plurality of reinforcing members are plate-like bodies,
A first edge that is longer than the short side of the base member and is coupled to the base member and the sidewall plate;
A second edge that intersects the first edge at the predetermined angle and is coupled to the non-flange surface;
A third edge facing the first edge and having a length corresponding to the short side of the base member;
A fourth edge facing the second edge and connecting one end of the first edge and one end of the third edge;
The side wall unit according to claim 17, comprising:   In the plurality of reinforcing members, a portion corresponding to an intersection of the first edge and the second edge, and a portion corresponding to a coupling position of the base member and the side wall plate in the first edge. The side wall unit according to claim 19, wherein a cutout portion is formed in one or both of the above.   The side wall according to claim 17, wherein the base member is coupled to the circumferential joining flange so as to stand up from a position other than a short-side end of the non-flange surface of the circumferential joining flange. unit.   The side wall unit according to claim 17, wherein a plurality of holes for passing mechanical fasteners are formed along a long side direction of the circumferential joining flange.   23. The side wall unit according to claim 22, wherein the plurality of holes have a diameter in a central portion in the long side direction that is larger than a diameter in an end portion in the long side direction of the circumferential joining flange.   The side wall unit according to claim 17, wherein a groove for inserting a seal layer is formed on the flange surface of the circumferential joining flange.   18. The side wall unit according to claim 17, wherein a height direction joint flange having an L-shaped cross section is coupled to two opposing end portions in the height direction.   A liquid storage tank comprising a side wall unit manufactured using the method according to claim 1.   A liquid storage tank comprising the side wall unit according to any one of claims 17 to 25.

Images