Patent Publication Number: US-2022213712-A1

Title: Structure reinforcing material, method for manufacturing reinforcing material, and method for manufacturing structure

Description:
FIELD 
     The present invention relates to a structure, a reinforcement member, a reinforcement member manufacturing method, and a structure manufacturing method. 
     BACKGROUND 
     A column-shaped structure is used in various use applications such as an antenna support pole for supporting an antenna in a base station of a mobile phone or the like, a power pole, a telephone pole, and a street lamp pole. An antenna in a base station of a mobile phone or the like is fixed to a structure called an antenna support pole (e.g., see Patent Document 1). Conventionally, there has been known a structure in which rigidity is increased by filling reinforcement materials such as polystyrene foam into a cylinder having an antenna mounting portion (e.g., see Patent Document 2). 
     LIST OF DOCUMENTS 
     Patent Documents 
     
         
         Patent Document 1: Japanese Patent Application Publication No. 2005-318077 
         Patent Document 2: Japanese Patent Application Publication No. H08-316713 
       
    
     SUMMARY 
     Technical Problem 
     In order to cope with an increase in the load applied to the structure, it is preferable to increase the rigidity of the structure without further change of the structure. 
     Solution to Problem 
     According to an aspect of the present invention, a structure is provided. The structure may include a main body portion. The structure may include a plurality of reinforcement members arranged in the main body portion. Each of the reinforcement members may include a base material formed of resin or metal. Each of the reinforcement members may include the base material formed of fiber reinforced resin. Each of the reinforcement members may include the base material formed of fiber reinforced resin, and a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. Each of the reinforcement members may include the base material formed of foamed synthetic resin, and a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. 
     The main body portion may include at least one fixing portion which fixes the plurality of reinforcement members into the main body portion. 
     The main body portion may have a hollow configuration surrounding an internal space thereof. The plurality of reinforcement members may be arranged at the internal space. 
     The plurality of reinforcement members may include reinforcement members having different sizes. 
     The plurality of reinforcement members may be arranged in a plurality of layers in the main body portion. 
     The fixing portion may include a filler material. The filler material is filled in at least a part of the inside of the hollow configuration so as to be in contact with at least some reinforcement members among the plurality of reinforcement members and an inner surface of the hollow configuration. 
     The internal space may be separated into a plurality of regions by the filler material. 
     Sizes of the plurality of arranged reinforcement members may be different in correspondence to the separated regions. 
     The main body portion may have a hollow configuration surrounding an internal space thereof. The plurality of reinforcement members may be arranged at the internal space. The main body portion may include at least one fixing portion which fixes the plurality of reinforcement members into the main body portion. The internal space may be separated into a plurality of regions by the fixing portion. Elasticity of the coating layers of the plurality of arranged reinforcement members may be different in correspondence to the separated regions. 
     The filler material may include polyurea resin. 
     The main body portion may have a hollow configuration surrounding an internal space thereof. The plurality of reinforcement members may be arranged at the internal space. The main body portion may include at least one fixing portion which fixes the plurality of reinforcement members into the main body portion. The fixing portion may include a filler material which is filled in at least a part of the inside of the hollow configuration so as to be in contact with at least some reinforcement members among the plurality of reinforcement members and an inner surface of the hollow configuration. The filler material may include polyurea resin. The polyurea resin included in the filler material may have higher viscosity than polyurea resin in the coating layer. 
     The fixing portion may include a connection portion and an extension portion. The connection portion may have a side surface connected to an inner surface of the hollow configuration. The extension portion may extend from a main surface of the connection portion along an extension direction of the hollow configuration. 
     The main body portion may include a cover portion which closes an opening. 
     The main body portion may include at least one material selected from a group consisting of metal, ceramic, wood, and resin. A foamed synthetic resin may be arranged at the internal space. The plurality of reinforcement members may be embedded in the foamed synthetic resin at the internal space. 
     The plurality of reinforcement members may be embedded in the material of the main body portion. 
     The material of the main body portion may be resin or concrete. 
     Each of the reinforcement members may have a spherical shape, a polyhedron shape, or a columnar shape. 
     The main body portion may include a cylindrical portion as the hollow configuration. The plurality of reinforcement members may be arranged in the cylindrical portion. The fixing portion may fix the plurality of reinforcement members into the cylindrical portion. 
     Each of the reinforcement members may have a spherical shape. An inner diameter of the cylindrical portion may not be less than 2 times and not be more than 20 times a diameter of each of the reinforcement members. 
     The plurality of reinforcement members may be arranged in a plurality of layers in an axial direction of the cylindrical portion. 
     The fixing portion may include a filler material which is filled in at least a part of the inside of the cylindrical portion so as to be in contact with at least some reinforcement members among the plurality of reinforcement members and an inner surface of the cylindrical portion. 
     The fixing portion may include the filler material at a plurality of positions spaced apart from each other in an axial direction of the cylindrical portion. 
     The plurality of reinforcement members may be arranged in a partial region at a base end in an axial direction of the cylindrical portion. 
     The cylindrical portion may be configured such that a plurality of cylinders communicate with each other. The plurality of reinforcement members may be arranged in a partial region at a base end of each of the cylinders in an axial direction of the cylindrical portion. 
     The cylindrical portion may be configured such that a plurality of cylinders communicate with each other. Each of the cylinders may have a flange portion on at least one end. The flange portions of the adjacent cylinders are connected to each other. A rib may be arranged as being connected between a main surface of the flange portion and a side surface of the cylindrical portion. An external reinforcement portion may be arranged on an outer surface of the cylindrical portion so as to cover a pair of the connected flange portions and the ribs each corresponding thereto. The external reinforcement portion may be formed of polyurea resin. 
     The fixing portion may include a filler material. The filler material may be filled in at least a part of the inside of the cylindrical portion so as to be in contact with at least some reinforcement members among the plurality of reinforcement members and an inner surface of the cylindrical portion. The filler material may include polyurea resin having higher viscosity than polyurea resin applied on the outer surface of the cylindrical portion. 
     The structure may be an antenna support pole which supports an antenna. The structure may be a power pole which supports a power transmission line. The structure may be a telephone pole which supports a communication line. The structure may be a street lamp pole to which a street lamp is attached. 
     The structure may be a pallet on which an article is placed. The structure may be a box body having a space therein. The structure may be an airframe of a manned or unmanned aircraft. The structure may be a component of a vehicle. The structure may be a scaffold plank for construction. 
     The structure may be a panel as a building material. The structure may further include a fastening portion. One end of the fastening portion may be embedded in the main body portion. The other end of the fastening portion may be exposed. 
     The structure may be an impact absorbing member, a corrosion inhibitor, or a thermal insulator. 
     The structure may be a pipe body to be inserted as a new pipe into an aged existing pipe. The structure may be a container to be used as a packaging container. The structure may be a rail tie for railroad. 
     According to another aspect of the present invention, a reinforcement member is provided. A plurality of the reinforcement members may be arranged in a structure so as to reinforce the structure. The reinforcement member may include a base material formed of resin or metal. The reinforcement member may include the base material formed of fiber reinforced resin. The reinforcement member may further include a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. The reinforcement member may include the base material formed of foamed synthetic resin, and a coating layer formed of polyurea resin. The coating layer may cover an outer surface of the base material. 
     The reinforcement member may have a spherical shape. The reinforcement member may have a polyhedron shape or a columnar shape. 
     A foaming magnification A of the foamed synthetic resin in the base material and a thickness T1 of the coating layer may satisfy (A/20)−1≤T1≤(A/20)+1 [mm]. 
     According to another aspect of the present invention, a manufacturing method of a reinforcement member is provided as a plurality of reinforcement members being arranged in a structure so as to reinforce the structure. The manufacturing method of the reinforcement member may include a molding step of molding a base material formed of foamed synthetic resin into a spherical shape, a polyhedral shape, or a columnar shape. In the molding step, the base material formed of fiber reinforced resin may be molded into a spherical shape, a polyhedral shape, or a columnar shape. The manufacturing method may further include an injecting step of injecting a coating material of polyurea resin onto a surface of the molded base material. In the molding step, the base material formed of foamed synthetic resin may be formed into a spherical shape, a polyhedral shape, or a columnar shape. Further, the base material may be changed in size. In the molding step, the maximum size of the base material formed of fiber reinforced resin (the diameter when the base material is spherical) may be 10 mm or larger. The maximum size of the base material may be not less than 1 time and not more than 20 times the maximum size of a cross-section of the hollow configuration of the structure sectioned in a direction perpendicular to the axial direction. The manufacturing method may further include an injecting step of injecting a coating material of polyurea resin onto a surface of the molded base material. 
     A thickness of the coating layer to be formed on a surface of the base material in the injecting step may be set in accordance with a foaming magnification of the foamed synthetic resin in the base material. The thickness T1 of the coating layer may be set to satisfy (A/20)−1≤T1≤(A/20)+1 [mm], while A represents the foaming magnification of the foamed synthetic resin in the base material. 
     In another aspect of the present invention, a manufacturing method of a structure is provided. The structure may have a hollow configuration surrounding an internal space thereof. The manufacturing method may include a preparation step, a carrying-in step, and a step of arranging a fixing portion. In the preparation step, a plurality of reinforcement members may be prepared. Each reinforcement member may include at least a base material formed of resin or metal. Each reinforcement member may include a base material formed of foamed synthetic resin, and a coating layer formed of polyurea resin. The coating layer may cover an outer surface of the base material. In a carrying-in step, the plurality of reinforcement members may be carried into the internal space from an opening arranged at the main body portion. In a step of arranging a fixing portion, the fixing portion which fixes the plurality of reinforcement members may be fixed into the main body portion. Each of the reinforcement members may include the base material formed of fiber reinforced resin. Each of the reinforcement members may include the base material formed of fiber reinforced resin, and a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. Each of the reinforcement members may include the base material formed of foamed synthetic resin, and a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. 
     The manufacturing method may further include a pressing step of pressing the plurality of reinforcement members into the internal space. After the pressing step, the plurality of reinforcement members may be fixed into the main body portion by the fixing portion. 
     The step of arranging the fixing portion may include a filling step of filling at least a part of the internal space with a filler material as the fixing portion. 
     In the carrying-in step, the reinforcement members having different sizes may be carried into the internal space. 
     The plurality of reinforcement members may be arranged in a plurality of layers in the main body portion. The carrying-in step may be performed before and after the step of arranging the fixing portion, respectively. The internal space may be separated into a plurality of regions by the fixing portion. The carrying-in step may be performed before and after the filling step, respectively. The internal space may be separated into a plurality of regions by the filler material. The carrying-in step and the filling step may be repeated plural times. In each of plural times of the carrying-in steps, sizes of the plurality of reinforcement members may be different in correspondence to the separated regions. In each of the plural times of carrying-in steps, elasticity of the coating layers of the plurality of arranged reinforcement members may be different in correspondence to the separated regions. 
     The fixing portion may include a connection portion having a side surface connected to an inner surface of the hollow configuration, and an extension portion extending from a main surface of the connection portion along an extension direction of the hollow configuration. In the carrying-in step, the plurality of reinforcement members may be carried into a space between the extension portion and an inner surface of the main body portion. 
     The filler material may include polyurea resin. Each of the reinforcement members may have a spherical shape, a polyhedron shape, or a columnar shape. 
     The main body portion may include a cylindrical portion as the hollow configuration. In the carrying-in step, the plurality of reinforcement members may be arranged in the cylindrical portion. The fixing portion may fix the plurality of reinforcement members into the cylindrical portion. 
     Each of the reinforcement members may have a spherical shape. An inner diameter of the cylindrical portion may not be less than 2 times and not be more than 20 times a diameter of the reinforcement member. 
     The cylindrical portion may be configured such that a plurality of cylinders communicate with each other. Each of the cylinders may have a flange portion on at least one end. The flange portions of the adjacent cylinders may be connected to each other. A rib may be arranged as being connected between a main surface of the flange portion and a side surface of the cylindrical portion. The manufacturing method may further include an external reinforcement portion forming step of forming an external reinforcement portion on an outer surface of the cylindrical portion so as to cover a pair of the connected flange portions and the ribs. The external reinforcement portion forming step may further include an application step of applying polyurea resin on the outer surface of the cylindrical portion so as to cover a pair of the connected flange portions and the ribs. 
     The plurality of reinforcement members may be arranged in a partial region at a base end in an axial direction of the cylindrical portion. 
     The cylindrical portion may be configured such that a plurality of cylinders communicate with each other. The plurality of reinforcement members may be arranged in a partial region at a base end of each of the cylinders in an axial direction of the cylindrical portion. 
     According to another aspect of the present invention, a manufacturing method of a structure which includes a main body portion is provided. The manufacturing method may include a preparation step and a step of forming the main body portion. In the preparation step, a plurality of reinforcement members may be prepared. Each of the reinforcement members may include a base material formed of resin. In the step of forming the main body portion, the main body portion may be formed by molding a material of the main body portion such that the plurality of reinforcement members are embedded therein. Each of the reinforcement members may include the base material formed of fiber reinforced resin. Each of the reinforcement members may include the base material formed of fiber reinforced resin, and a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. Each of the reinforcement members may include the base material formed of foamed synthetic resin, and a coating layer which is formed of polyurea resin and which covers an outer surface of the base material. 
     The material of the main body portion may be resin or concrete. 
     The material of the main body portion may be foamed synthetic resin for the main body portion. The step of forming the main body portion may include a step of molding the foamed synthetic resin for the main body portion such that the plurality of reinforcement members are embedded therein. The manufacturing method may further include a main body portion application step of applying polyurea resin to an outside of the foamed synthetic resin for the main body portion. 
     It should be noted that the summary of the present invention described above does not list all of the necessary features of the present invention. The present invention may also include a sub-combination of the features described above. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view showing an example of an antenna support pole  1  in a first embodiment of the present invention. 
         FIG. 2  shows an example of a flange portion  14  and ribs  15  arranged at one end of a cylinder  12 . 
         FIG. 3  is a sectional view showing as enlarging a part of a cylindrical portion  10  in the antenna support pole  1  of  FIG. 1 . 
         FIG. 4A  is a sectional view showing an example of a reinforcement member  20  arranged in the cylindrical portion  10 . 
         FIG. 4B  is a view showing the relationship between the foaming magnification of foamed synthetic resin which forms a base material  22  and a thickness T1 of a coating layer  24 . 
         FIG. 4C  is a flowchart showing an example of a manufacturing process of the reinforcement member  20 . 
         FIG. 4D  is a sectional view showing another example of the reinforcement member  20  arranged in the cylindrical portion  10 . 
         FIG. 4D  is a sectional view showing another example of the reinforcement member  20  arranged in the cylindrical portion  10 . 
         FIG. 5  is a plan view showing an arrangement example of the reinforcement members  20  in the cylinder  12 . 
         FIG. 6  is a view showing an example of a layer configuration of the reinforcement members  20  in the cylinder  12 . 
         FIG. 7  is a plan view showing an arrangement example of the reinforcement members  20  in a cylinder  11 . 
         FIG. 8  is a plan view showing an arrangement example of the reinforcement members  20  in a cylinder  13 . 
         FIG. 9  is a partial sectional view showing an example of the antenna support pole  1  in a second embodiment of the present invention. 
         FIG. 10  is a partial sectional view showing an example of the antenna support pole  1  in a third embodiment of the present invention. 
         FIG. 11  is a partial sectional view showing an example of the antenna support pole  1  in a fourth embodiment of the present invention. 
         FIG. 12  is a partial sectional view showing an example of the antenna support pole  1  in a fifth embodiment of the present invention. 
         FIG. 13  is a view showing an example of a manufacturing method of a structure of the present invention. 
         FIG. 14  is a view showing an example of a carrying-in device  90 . 
         FIG. 15  is a partial sectional view showing an example of the antenna support pole  1  in a sixth embodiment of the present invention. 
         FIG. 16  is a partial sectional view showing an example of the antenna support pole  1  in a seventh embodiment of the present invention. 
         FIG. 17  is a sectional view showing an example of the antenna support pole  1  in an eighth embodiment of the present invention. 
         FIG. 18  is a view showing another example of the reinforcement member  20 . 
         FIG. 19  is a view showing another example of the reinforcement member  20 . 
         FIG. 20  is a view for explaining conditions of a simulation test. 
         FIG. 21  is a view showing a modification example of the antenna support pole  1 . 
         FIG. 22  is a view showing a modification example of the antenna support pole  1 . 
         FIG. 23  is a view showing a modification example of the antenna support pole  1 . 
         FIG. 24  is a view showing a modification example of the antenna support pole  1 . 
         FIG. 25  is a view showing an example of a power pole  4 . 
         FIG. 26  is a view showing an example of a street lamp pole  6 . 
         FIG. 27  is a perspective view showing an example of the structure  100  in a ninth embodiment of the present invention. 
         FIG. 28  is a sectional view showing an example of a cross-section of the structure  100  shown in  FIG. 27 . 
         FIG. 29  is a sectional view showing an example of the structure  100  in a tenth embodiment of the present invention. 
         FIG. 30  is a sectional view showing an example of the structure  100  in an eleventh embodiment of the present invention. 
         FIG. 31  is a sectional view showing an example of the structure  100  in a twelfth embodiment of the present invention. 
         FIG. 32  is a perspective view showing an example of a pallet  210  in a thirteenth embodiment of the present invention. 
         FIG. 33  is a sectional view showing an example of a cross-section of the pallet  210  shown in  FIG. 32 . 
         FIG. 34  is a perspective view showing an example of a box body  220  in a fourteenth embodiment of the present invention. 
         FIG. 35  is a sectional view showing an example of the box body  220  shown in  FIG. 34 . 
         FIG. 36  is a view showing an example of an airframe  230  of an aircraft in a fifteenth embodiment of the present invention. 
         FIG. 37  is a view showing an example of a component of a vehicle in a sixteenth embodiment of the present invention. 
         FIG. 38  is a view showing an example of a scaffold plank  250  for construction in a seventeenth embodiment of the present invention. 
         FIG. 39  is a view showing an example of a panel  260  as a building material in an eighteenth embodiment of the present invention. 
         FIG. 40  is a view showing an example of an impact absorbing member  270  in a nineteenth embodiment of the present invention. 
         FIG. 41  is a view showing another example of the impact absorbing member  270 . 
         FIG. 42  is a sectional view showing an example of a pipe body  280  in a twentieth embodiment of the present invention. 
         FIG. 43  is a sectional view showing an example of a packaging container  300  in a twenty-first embodiment of the present invention. 
         FIG. 44  is a sectional view showing an example of a rail tie  410  in a twenty-second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Further, all the combinations of the features described in the embodiments are not necessarily essential to solutions of the present invention. 
     In this specification, when a structure is a support pole, one side in a direction parallel to the height direction of the support pole is referred to as “upper” and the other side is referred to as “lower”. One of two main surfaces of a layer or another member is referred to as an upper surface, and the other surface is referred to as a lower surface. The directions of “upper” and “lower” are not limited to the direction of gravity or the direction of attachment of the support pole. 
     In this specification, technical matters may be described by using orthogonal coordinate axes of an X axis, a Y axis, and a Z axis. In this specification, when the structure has a cylindrical portion, an axial direction of the cylindrical portion is defined as a Z axis, and a plane perpendicular to the Z axis is defined as an XY plane. 
       FIG. 1  is a side view showing an example of an antenna support pole  1  for antenna support in a first embodiment of the present invention. The antenna support pole  1  may be a column or a tower-like structure for installing an antenna  2 . The antenna support pole  1  is an example of a column body which is the structure of the present invention. The antenna  2  may be an antenna for various types of communication such as a mobile phone, a wireless LAN, and a wireless sign. In one example, the antenna  2  may be an antenna for a fifth generation mobile communication system (5G). The antenna  2  may include both an antenna for a fourth generation mobile communication system (4G) and an antenna for 5G. 
     The antenna support pole  1  has rigidity to withstand the weight of the antenna  2 . In particular, the antenna support pole  1  of the present embodiment may be formed by reinforcing an existing column body. The expansion of the antenna base station is approaching the limit, and there is the case in which an antenna is expanded by using an existing support pole in an existing antenna base station. In particular, the weight of an antenna for the fifth generation mobile communication system (5G) is heavy compared with the previous antenna weight. Therefore, when an antenna for 5G is added to an existing column body, it is desirable to further increase the rigidity of the antenna support pole  1  on which the antenna for 5G is to be installed. Here, the type of the antenna  2  is not limited to the cases described above. In the antenna support pole  1  of the present embodiment, a plurality of reinforcement members each including a base material formed of metal or resin are provided in a cylindrical portion constituting the pole to cope with an increase in weight due to an increase in the number of antennas  2  or the like. 
     The antenna support pole  1  includes a cylindrical portion  10  which supports the antenna  2 . The cylindrical portion  10  is an example of a main body portion. The main body portion may have a hollow configuration in which an internal space is surrounded. In the present example, the main body portion includes the cylindrical portion  10  as the hollow configuration. In the present example, the cylindrical portion  10  is configured such that a plurality of cylinders (a cylinder  11  (first cylinder), a cylinder  12  (second cylinder), and a cylinder  13  (third cylinder)) communicate with each other. Each cylinder  11 ,  12 ,  13  includes a flange portion  14  on at least one end. The cylinder  11  may have a flange portion  14   a  on one end and a flange portion  14   b  on the other end. The cylinder  12  may have a flange portion  14   c  on one end and a flange portion  14   d  on the other end. The cylinder  13  may have a flange portion  14   e  on one end and a flange portion  14   f  on the other end. 
     The flange portions  14   b ,  14   c  of the adjacent cylinders  11 ,  12  are connected, and the flange portions  14   d ,  14   e  of the adjacent cylinders  12 ,  13  are connected. In this manner, the flange portions  14  of adjacent cylinders may be connected to each other to form the cylindrical portion  10 . The cylinder  11  is arranged at the lowermost position (in a direction close to a base end of the cylindrical portion  10 ) among the plurality of cylinders, and the cylinder  12  and the cylinder  13  may be connected in this order upward from the cylinder  11  (toward a top end of the cylindrical portion  10 ). The cylinder  11  may have the largest inner diameter and the largest outer diameter among the plurality of cylinders, and the inner diameter and the outer diameter may decrease in the order of the cylinder  12  and the cylinder  13  as the cylinder is arranged on the upper side. Each of the cylinders  11 ,  12 ,  13  may have an inner diameter and an outer diameter constant in a predetermined range from one end to the other end. 
     Each of the cylinders  11 ,  12 ,  13  configuring the cylindrical portion  10  may be formed of metal such as steel, and may be further subjected to a surface treatment such as hot dip galvanizing. Here, the cylindrical portion  10  may be formed of fiber reinforced resin (FRP). The cylindrical portion  10  as the main body portion may include at least one material selected from the group consisting of metal, ceramic, wood, and resin. 
     The flange portion  14   a  arranged at a lower end of the cylinder  11  may be used when the antenna support pole  1  is attached to a structural object such as a building. Instead of the flange portion  14   a , a separate mounting configuration may be arranged. A lightning rod  16  may be attached to a flange portion  14  arranged at an upper end of the cylinder  13 . 
       FIG. 2  shows an example of the flange portion  14  and ribs  15  arranged at one end of the cylinder  12 . The flange portions  14  and the ribs  15  at the other cylinders  11 ,  13  may have the similar configuration. Ribs  15   c  extending in the axial direction may be arranged between a main surface  18  of each flange portion  14  (upper surface or lower surface) and a side surface  17  of the corresponding cylinder. The rigidity of the cylindrical portion  10  can be increased by the ribs  15   c . A plurality of the ribs  15   c  may be arranged per one flange portion  14 . The plurality of ribs  15   c  may be arranged to extend radially from the axis center in a top view. The top view refers to a view from the positive direction of the Z axis. The other flange portions  14  and ribs  15  may have the similar configuration. The main surface of each rib  15   c  may have a triangular shape. 
       FIG. 3  is a conceptual view showing an enlarged cross-section of a part of the cylindrical portion  10  in the antenna support pole  1  of  FIG. 1 .  FIG. 3  schematically shows a cross-section of the section A of  FIG. 1  taken along the ZX plane. The antenna support pole  1  includes a plurality of reinforcement members  20  arranged in the cylindrical portion  10 . In  FIG. 3 , the arrangement of the plurality of reinforcement members  20  in the cylindrical portion  10  is schematically shown. The plurality of reinforcement members  20  are arranged in the may body portion. As in the present example, when the main body portion has the hollow configuration in which the internal space is surrounded, the plurality of reinforcement members  20  are arranged at the internal space. In the present example, the plurality of reinforcement members  20  are arranged at the internal space which is surrounded by the cylindrical portion  10 . 
     The main body portion of the antenna support pole  1  includes at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the main body portion. In the present example, the main body portion includes at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the cylindrical portion  10 . In the present example, the fixing portion  30  includes a filler material  32 . The filler material  32  is filled in at least a part of the inside of the hollow configuration so as to be in contact with at least some reinforcement members  20  among the plurality of reinforcement members  20  and the inner surface of the hollow configuration. In the present example, the filler material  32  is filled in at least a part of the inside of the cylindrical portion  10  so as to be in contact with at least some reinforcement members  20  among the plurality of reinforcement members  20  and the inner surface of the cylindrical portion  10 . 
     In the present example, a plurality of the filler materials  32   a ,  32   b  are formed. The filler material  32   a  is in contact with the reinforcement members  20  arranged in the cylinder  11  and the inner surface of the cylinder  11 . The filler material  32   b  is in contact with the reinforcement members  20  arranged in the cylinder  12  and the inner surface of the cylinder  12 . Although not shown in  FIG. 3 , another filler material  32  in contact with the reinforcement members  20  arranged in the cylinder  13  and the inner surface of the cylinder  13  may also be arranged. 
     The filler material  32   a  may be arranged in the range of a thickness d1 in the axial direction of the cylindrical portion  10 . The filler material  32   b  may be arranged in the range of a thickness d2 in the axial direction of the cylindrical portion  10 . Thus, in the present example, each of the filler materials  32  is arranged at a part of the inside of the cylindrical portion  10 . The filler material  32   a  and the filler material  32   b  may be spaced apart from each other by a length L1. In other words, the fixing portion  30  may include the filler materials  32  at a plurality of positions spaced apart from each other in the axial direction of the cylindrical portion  10 . Thicknesses d1, d2 of the filler material  32   a  and the filler material  32   b  may be smaller than the spaced distance L1 therebetween, respectively. The thickness d1 and the thickness d2 may be the same or different. 
     In particular, it is preferable that the filler material  32   a  is arranged so as to be overlapped with a section where the pair of flange portions  14   b ,  14   c  are arranged in the axial direction of the cylindrical portion  10 . Similarly, it is preferable that the filler material  32   b  is arranged so as to be overlapped with a section where the pair of flange portions  14   d ,  14   e  are arranged in the axial direction of the cylindrical portion  10 . Since stresses are likely to be applied to the sections where the flange portions  14  and the ribs  15  are arranged, the rigidity of the cylindrical portion  10  can be increased particularly by arranging the filler materials  32   a ,  32   b . However, the filler materials  32   a ,  32   b  may be arranged at positions different from the connecting positions of the cylinder  11  and the cylinder  12 . 
     The filler material  32   a  and the filler material  32   b  separate the internal space of the hollow configuration into a plurality of regions. In the present example, the filler material  32   a  and the filler material  32   b  separate the internal space of the cylindrical portion  10  into a plurality of regions. The filler material  32   a  and the filler material  32   b  fill the space so as to surround the reinforcement members  20  in the cylindrical portion  10  in the range of the thickness d1 and the thickness d2, respectively. The inside of the cylindrical portion  10  is divided into a region  41 , a region  42 , and a region  43  in the axial direction of the cylindrical portion  10 . The region  41  is a first region located below the position where the filler material  32   a  is arranged. The region  42  is a second region sandwiched between the position where the filler material  32   a  is arranged and the position where the filler material  32   b  is arranged. The region  43  is a third region  43  located above the position where the filler material  32   b  is arranged. The filler materials  32  may be formed of resin. In particular, the filler materials  32  may be formed of polyurea resin. 
     Polyurea resin is, for example, resin having urea bond formed by a chemical reaction between isocyanate and an amino group. As an example, polyurea resin is formed through a reaction between polyisocyanate and polyamine. 
     In the antenna support pole  1  of the present embodiment, an external reinforcement portion  52  is arranged on the outer surface of the cylindrical portion  10  so as to cover the pair of flange portions  14   b ,  14   c  connected to each other. The external reinforcement portion  52  may cover the ribs  15   b ,  15   c  as well as the flange portions  14   b ,  14   c . The external reinforcement portion  52  may cover a part of the side surface of the cylinder  11  and a part of the side surface of the cylinder  12  in the Z-axis direction. Similarly, an external reinforcement portion  54  is arranged on the outer surface of the cylindrical portion  10  so as to cover the pair of flange portions  14   d ,  14   e  connected to each other. The external reinforcement portion  54  may cover the ribs  15   d ,  15   e  as well as the flange portions  14   d ,  14   e . The external reinforcement portion  54  may cover a part of the side surface of the cylinder  12  and a part of the side surface of the cylinder  13  in the Z-axis direction. The external reinforcement portions  52 ,  54  may each be a protective film formed of polyurea resin. 
     The viscosity of polyurea resin forming the filler material  32  may be higher than that of polyurea resin contained in the external reinforcement portions  52 ,  54 . Accordingly, the fluidity of the external reinforcement portions  52 ,  54  is suppressed, and the external reinforcement portions  52 ,  54  are easily formed in specific regions in the cylindrical portion  10 . However, the present invention is not limited to this case, and depending on the use application, the viscosity of polyurea resin forming the filler material  32  may be lower than that of polyurea resin contained in the external reinforcement portions  52 ,  54 . In one example, in order to enlarge the range in which the filler material  32  is filled in the cylindrical portion  10 , the viscosity of polyurea resin used as the filler material  32  may be equal to or lower than that of polyurea resin contained in the external reinforcement portions  52 ,  54 . Here, the external reinforcement portions  52 ,  54  each are not limited to a protective film formed of polyurea resin. 
     Each reinforcement member  20  may be spherical in shape. However, as will be described later, the shape of each reinforcement member  20  is not limited to a spherical shape. In this specification, the spherical shape is not limited to a true spherical shape, and includes a spherical shape and an ellipsoid exhibiting surface unevenness or sphericity caused by a production process. The plurality of reinforcement members  20  may be arranged in a plurality of layers in the axial direction (Z-axis direction) of the cylindrical portion  10 , or may be arranged by being arbitrarily filled without forming layers. 
       FIG. 4A  is a sectional view showing an exemplary reinforcement member  20  arranged in the cylindrical portion  10 . Each reinforcement member  20  includes a base material  22  and a coating layer  24  which covers the outer surface of the base material  22 . The base material  22  may be spherical in shape. The thickness of the coating layer  24  is less than the diameter of the base material  22 . In one example, the diameter of the base material  22  may be 10 mm or more, and the thickness of the coating layer  24  may be 0.5 mm or more and 6 mm or less. In one example, the diameter of the base material  22  is 40 mm, the thickness of the coating layer  24  is 4 mm, and the overall diameter of the reinforcement member  20  is 48 mm. 
     In the present example, the base material  22  is formed of foamed synthetic resin. As an example, synthetic resin forming the base material  22  is a polymer compound. As a more specific example, synthetic resin forming the base material  22  is formed of one or more materials selected from polystyrene, polyethylene, polypropylene, and polyurethane. Foamed synthetic resin refers to synthetic resin described above in which fine bubbles are dispersed. 
     In one example, the base material  22  is formed of foamed styrene (foamed polystyrene). 
     The coating layer  24  is arranged so as to cover the entire outer surface of the base material  22 . The coating layer  24  is formed of polyurea resin. Polyurea resin is, for example, resin having urea bond formed by a chemical reaction between isocyanate and an amino group. As an example, polyurea resin is formed through a reaction between polyisocyanate and polyamine. In one example, as the content ratio of “diethyltoluenediamine” which is a constituent solution of an amine solution and “diphenylmethane diisocyanate” which is a constituent solution of an isocyanate solution increases, the hardness of polyurea resin increases and the elasticity thereof decreases. Thus, depending on the use application of the structure, the elasticity of the coating layer  24  of the reinforcement member  20  can be changed. Note that polyurea resin contained in the filler material  32  may have higher viscosity than polyurea resin in the coating layer  24 . However, it is not limited thereto. 
       FIG. 4B  is a view showing the relationship between the foaming magnification of the foamed synthetic resin which forms the base material  22  and a thickness T1 of the coating layer  24 . In the present example, the thickness T1 of the coating layer  24  is determined according to the foaming magnification of the base material  22 . The foaming magnification indicates an expansion ratio (volume ratio) when, for example, particles of synthetic resin (raw material beads) are expanded by heating with steam or the like. More specifically, in foamed synthetic resin having the foaming magnification of 50, air accounts for 98% of the total product (volume) and synthetic resin accounts for 2%. Generally, the foaming magnification and the strength of foamed synthetic resin are inversely proportional. For example, foamed synthetic resin having the foaming magnification of 30 has strength twice as high as that of foamed synthetic resin having the foaming magnification of 60, but has a volume of about half thereof. 
     The foaming magnification is selected according to the use application of the structure in which the reinforcement member  20  is used. Depending on the use application, the thickness that the base material  22  should have is determined. The foaming magnification is determined according to the strength of the base material  22 . 
     The thickness T1 of the coating layer  24  is set so as to be substantially proportional to the foaming magnification. Normally, the thickness T1 of the coating layer  24  is about A/20 mm, where A denotes the foaming magnification. For example, in a normal cylindrical body, when the foaming magnification is 40, the thickness T1 of the coating layer  24  is preferably about 2 mm. In addition, when the foaming magnification is 60, the thickness T1 of the coating layer  24  is preferably about 3 mm. By making the thickness T1 of the coating layer  24  proportional to the foaming magnification A, the thickness T1 of the coating layer  24  is increased as the strength of the base material  22  is lowered, so that the strength of the entire structure can be maintained. 
     However, the thickness T1 of the coating layer  24  may be increased or decreased with respect to a normal thickness. As an example, the thickness T1 of the coating layer  24  is increased to increase the strength, and the thickness T1 of the coating layer  24  is decreased to reduce the cost. As an example, the thickness T1 of the coating layer  24  may be in the range indicated by dotted lines in  FIG. 4B . 
       ( A/ 20)−1≤ T 1≤( A/ 20)+1 [mm]
 
     Note that the foaming magnification of foamed synthetic resin can be estimated from the material type of synthetic resin and the weight per unit volume of foamed synthetic resin. That is, the volume of synthetic resin before foaming is estimated from the weight per unit volume of foamed synthetic resin and the material of synthetic resin. Then, the foaming magnification is calculated from the estimated volume of the synthetic resin before foaming and the unit volume of foamed synthetic resin. 
       FIG. 4C  is a flowchart showing an example of a manufacturing process of the reinforcement member  20 . First, in an application selecting step S 11 , a use application of the structure (type of structure) in which the reinforcement member  20  is used is selected. 
     Next, in a foaming magnification selecting step S 12 , the foaming magnification of foamed synthetic resin used for the reinforcement member  20  is selected. The foaming magnification may be determined according to the use application of the structure selected in S 11 . 
     Next, in a base material molding step S 13 , the base material of foamed synthetic resin is molded into a predetermined shape. For example, the base material  22  formed of foamed synthetic resin is formed into a spherical shape, a polyhedral shape, or a columnar shape. 
     Next, in a parameter setting step S 14 , respective parameters for injecting a coating material are set. The parameters include, for example, the injection amount of the coating material per unit time with respect to the unit area of the base material  22 . 
     In a heating-pressing step S 15 , the base material  22  may be heated and pressed. However, the heating-pressing step S 15  may be omitted. 
     Next, in an injecting step S 16 , the coating material is injected onto the base material  22 . In S 16 , it is preferable to inject the coating material onto the entire surface of each base material  22 . 
     Next, in a drying step S 17 , the coating material is dried. Thus, the coating layer  24  is formed on the surface of the base material  22 . 
       FIG. 4D  is a sectional view showing another example of the reinforcement member  20  arranged in the cylindrical portion  10 . In the example shown in  FIGS. 1 to 4C , the reinforcement member  20  includes the base material  22  formed of foamed synthetic resin and the coating layer  24  which is formed of polyurea resin and which covers the outer surface of the base material  22 . However, the present invention is not limited thereto. 
     In the example shown in  FIG. 4D , each reinforcement member  20  includes a base material  23 . In the present example, the base material  23  is formed of fiber reinforced resin (FRP). Specifically, the base material  23  may be formed of glass fiber reinforced resin (GFRP) or carbon fiber reinforced resin (CFRP). Glass fiber reinforced resin (GFPR) is obtained by consolidating glass fibers with polyester resin, vinyl ester resin, epoxy resin, phenolic resin, or other thermoplastic resin. Carbon fiber reinforced resin (CFRP) is obtained by consolidating carbon fibers with polyester resin, vinyl ester resin, epoxy resin, phenolic resin, or other thermoplastic resin. However, fiber reinforced resin (FRP) is not limited to glass fiber reinforced resin (GFRP) and carbon fiber reinforced resin (CFRP). For example, fiber reinforced resin (FRP) may be aramid fiber (Kevlar fiber) reinforced resin, polyethylene fiber (Dynema fiber) reinforced resin, zylon fiber reinforced resin, or boron fiber reinforced resin. 
     Each reinforcement member  20  may include the coating layer  24  which is formed of polyurea resin and which covers the outer surface of the base material  23 . However, the reinforcement member  20  may not necessarily include the coating layer  24 . 
       FIG. 4E  is a sectional view showing another example of the reinforcement member  20  arranged in the cylindrical portion  10 . In  FIG. 4E , the reinforcement member  20  includes the base material  23  formed of fiber reinforced resin (FRP), but does not include the coating layer  24  formed of polyurea resin. Note that, in  FIGS. 4D and 4E , a base material formed of metal may also be used instead of the base material  23  formed of fiber reinforced resin (FRP). However, from a viewpoint of specific gravity and the like, it is preferable to use the base material  23  formed of fiber reinforced resin (FRP) rather than metal. 
     The rigidity of the structure can be increased in the example using the reinforcement member  20  in which the base material  23  is formed of glass fiber reinforced resin (GFRP) or carbon fiber reinforced resin (CFRP) ( FIG. 4D  or  FIG. 4E ) compared with the case using the reinforcement member  20  in which the base material  22  is formed of foamed synthetic resin ( FIG. 4A ). In particular, in order to further enhance rigidity when the rigidity of the main body portion of the structure is relatively high, it is preferable to use the reinforcement member  20  in which the base material  23  is formed of glass fiber reinforced resin (GFRP) or carbon fiber reinforced resin (CFRP). On the other hand, when the rigidity of the main body portion of the structure is relatively low, the effect of increasing the rigidity is likely to be manifested even when the reinforcement member  20  in which the base material  22  is formed of foamed synthetic resin is used. Depending on the use application, the material of the base material can be selected. 
     In the manufacturing process of the reinforcement member  20  shown in  FIG. 4D , S 11 , S 12 , and S 15  in  FIG. 4C  are omitted. In the base material molding step S 13  in  FIG. 4C , the base material  23  of the fiber reinforced resin (FRP) is molded into a predetermined shape. For example, in the base material molding step S 13 , the base material  23  of the fiber reinforced resin FRP is molded into a spherical shape, a polyhedron shape, or a columnar shape. In the parameter setting step S 14 , respective parameters for injecting the coating material are set. Next, in the injecting step S 16 , the coating material is injected onto the base material  23 . In S 16 , it is preferable to inject the coating material onto the entire surface of each base material  23 . Next, in the drying step S 17 , the coating material is dried. Thus, the coating layer  24  is formed on the surface of the base material  23 . On the other hand, in the manufacturing process of the reinforcement member  20  shown in  FIG. 4E , S 14 , S 16 , and S 17  are further omitted. Since the other steps are similar to the manufacturing process of the reinforcement member  20  shown in  FIG. 4D , the description thereof will not be repeated. 
       FIG. 5  is a plan view showing an arrangement example of the reinforcement members  20  in the cylinder  12 . The plurality of reinforcement members  20  are arranged in a plurality of layers in the axial direction of the cylindrical portion  10 . In  FIG. 5 , the inner diameter of the cylinder  12  is 180 mm, and the diameter of each reinforcement member  20  is 48 mm. In  FIG. 5 , a plurality of reinforcement members  20 - 1  configure a first layer, and a plurality of reinforcement members  20 - 2  configure a second layer. In the example of  FIG. 5 , a total of nine reinforcement members  20 - 1  configure the first layer. Specifically, in a top view, the first layer includes eight reinforcement members  20 - 1  located so that points of the respective reinforcement members  20 - 1  coincide with the apexes of a substantially regular octagon while being in contact with the inner surface of the cylinder  12 , and one reinforcement member  20 - 1  located at the center of the cylinder  12 . 
     On the other hand, a total of four reinforcement members  20 - 2  configure the second layer. The second layer includes four reinforcement members  20 - 2  located such that points of the reinforcement members  20 - 2  coincide with the apexes of a substantially regular quadrangle in a top view. 
       FIG. 6  is a view showing an example of a layer configuration of the reinforcement members  20  in the cylinder  12 . As shown in  FIG. 6 , a third layer formed by a plurality of reinforcement members  20 - 3  may be arranged in the same manner as the first layer. A fourth layer formed by a plurality of reinforcement members  20 - 4  has a configuration in which the arrangement in the second layer is rotated by 45 degrees in a plane parallel to the XY plane. The configurations of the first to fourth layers are repeated for the fifth and subsequent layers. 
       FIG. 7  is a plan view showing an arrangement example of the reinforcement members  20  in the cylinder  11 . The plurality of reinforcement members  20  may be arranged in a plurality of layers in the main body portion. In the present example, the plurality of reinforcement members  20  are arranged in the plurality of layers in the axial direction of the cylindrical portion  10 . In  FIG. 7 , the inner diameter of the cylinder  11  is 204.5 mm, and the diameter of each reinforcement member  20  is 48 mm. In  FIG. 7 , the plurality of reinforcement members  20 - 1  configure the first layer, and the plurality of reinforcement members  20 - 2  configure the second layer. In the example of  FIG. 7 , a total of 11 reinforcement members  20 - 1  configure the first layer. Specifically, in a top view, the first layer includes ten reinforcement members  20 - 1  located so that points of the respective reinforcement members  20 - 1  coincide with the apexes of a substantially regular decagon while being in contact with the inner surface of the cylinder  11 , and one reinforcement member  20 - 1  located at the center of the cylinder  11 . 
     On the other hand, a total of five reinforcement members  20 - 2  configure the second layer. The second layer includes five reinforcement members  20 - 2  located such that points of the reinforcement members  20 - 2  coincide with the apexes of a substantially regular pentagon in a top view. Thus, in each layer, in a top view, it may have a configuration in which the reinforcement members  20  are arranged at the apexes of substantially regular decagon while being in contact with the inner surface of the cylinder  11 . Note that the third layer and the fourth layer and thereafter may be similar to the first layer and the second layer. 
       FIG. 8  is a plan view showing an arrangement example of the reinforcement members  20  in the cylinder  13 . In  FIG. 8 , the inner diameter of the cylinder  13  is 106 mm, and the diameter of each reinforcement member  20  is 48 mm. In the cylinder  13 , in a top view, the first layer includes three reinforcement members  20 - 1  located so that points of the respective reinforcement members  20 - 1  coincide with the apexes of a substantially regular triangle while being in contact with the inner surface of the cylinder  13 . The second layer includes one reinforcement member  20 - 2  located at the center of on the cylinder  13  in top view. 
     In the arrangement of the reinforcement members  20  in the cylinder  12  shown in  FIGS. 5 and 6 , the diameter (48 mm) of each reinforcement member  20  is 33% of the inner diameter (180 mm) of the cylinder  12 , and is included in the range of 20% or more and 40% or less. In the arrangement of the reinforcement members  20  in the cylinder  11  shown in  FIG. 7 , the diameter of each reinforcement member  20  (48 mm) is 23% of the inner diameter (204.5 mm) of the cylinder  12 , and is included in the range of 20% or more and 30% or less. In the arrangement of the reinforcement members  20  in the cylinder  13  shown in  FIG. 8 , the diameter (48 mm) of each reinforcement member  20  is 45% of the inner diameter (106 mm) of the cylinder  13 , and is included in the range of 20% or more and 50% or less. 
     In other words, the inner diameter (180 mm) of the cylinder  12  is 3.75 times the diameter of the reinforcement member  20 , the inner diameter (204.5 mm) of the cylinder  11  is 4.26 times the diameter of the reinforcement member  20 , and the inner diameter (106 mm) of the cylinder  13  is 2.2 times the diameter of the reinforcement member  20 . The inner diameter of the cylindrical portion  10  is preferably not less than 1 time and not more than 20 times the diameter of the reinforcement member  20 , and more preferably not less than 1 time and not more than 10 times the diameter of the reinforcement member  20 , or not less than 2 times and not more than 10 times the diameter of the reinforcement member  20 . Thus, it is possible to effectively increase the rigidity of the antenna support pole  1 . 
     However, the arrangement of the reinforcement members  20  in the cylindrical portion  10  is not limited to the cases of  FIGS. 5, 6, 7, and 8 . In the cylindrical portion  10 , the reinforcement members  20  are not necessarily arranged in layers. In particular, when manufacturing the rigidity-enhanced antenna support pole  1  using the existing cylindrical portion  10 , the plurality of reinforcement members  20  are carried into the internal space from an opening formed in the main body portion of the cylindrical portion  10 , and the plurality of reinforcement members  20  are not necessarily arranged in layers. Even in the case in which the plurality of reinforcement members  20  are randomly arranged without being arranged in layers, the inner diameter of the cylindrical portion  10  is preferably not less than 1 time and not more than 20 times the diameter of the reinforcement member  20 , and more preferably not less than 1 time and not more than 10 times the diameter of the reinforcement member  20 . The diameter of the reinforcement member  20  is preferably 10 mm or more. The rigidity of the structure can be highest with the reinforcement members  20  each having the diameter of 60 mm among diameters of 10 mm, 20 mm, 40 mm, and 60 mm placed in the cylinder having the inner diameter of 300 mm. When the size of the reinforcement members  20  increases, it is possible to prevent the reinforcement members  20  from moving to a space generated when the structure such as the cylinder is bent by receiving external force, so that the rigidity thereof can be increased. 
     As shown in  FIGS. 1 to 8 , according to the antenna support pole  1  of the present embodiment, the reinforcement members  20  are arranged in the cylindrical portion  10 . The rigidity in the cylindrical portion  10  can be increased by the reinforcement members  20 , and displacement thereof can be suppressed. Therefore, it is possible to suppress the stress generated in the antenna support pole  1 . In particular, by setting the inner diameter of the cylindrical portion  10  to be not less than 2 times and not more than 20 times, particularly not less than 2 times and not more than 10 times the diameter of the reinforcement members  20 , it is possible to suppress the stress generated in the antenna support pole  1 . In particular, according to the results of the simulation and the actual experimental test, it is possible to increase the rigidity in the cylindrical portion  10  by using the reinforcement members  20  in which the base materials  23  are formed of fiber reinforced resin. Depending on the rigidity of the cylindrical portion  10 , the reinforcement members  20  including the base materials  22  formed of foamed synthetic resin can be used, and the weight of the antenna support pole  1  can be reduced. 
     Further, according to the antenna support pole  1  of the present embodiment, the external reinforcement portions  52 ,  54  are arranged on the outer surface of the cylindrical portion  10  so as to cover a pair of the connected flange portions  14  and ribs  15 . As a result, it is possible to cover from the outside a section where local stress is likely to be generated, so that the stress to be generated can be reduced. 
     Further, the antenna support pole  1  of the present embodiment may include the filler materials arranged at a plurality of positions spaced apart from each other in the axial direction of the cylindrical portion  10 . The filler materials having higher curing speed can be used as compared with the case in which the filler materials are filled in the entire inner region of the cylindrical portion  10 . 
     Since the structure of the present example includes the cylindrical portion  10  as the hollow configuration, the structure exhibits flexibility compared with a solid structure having the same sectional area, and generates several times the strength. Further, in the present embodiment, since the filler materials  32  formed of strong polyurea resin are arranged at the plurality of positions spaced apart from each other in the axial direction of the cylindrical portion  10 , the filler materials  32  serve as lateral members and the strength as a whole against bending stress can be increased. The above exhibits similar effects as a bamboo nodal structure of a plant. 
       FIG. 9  is a partial sectional view showing an example of the antenna support pole  1  of a second embodiment of the present invention. In the first embodiment, description has been provided on the case in which one filler material  32  is arranged as the fixing portion  30  in one cylinder, but the present invention is not limited thereto. As shown in  FIG. 9 , a plurality of filler materials  32   b ,  32   c  may be arranged in one cylinder  12 . In the present example, three or more filler materials  32   a ,  32   b ,  32   c  are arranged in the entire cylindrical portion  10 . 
       FIG. 10  is a partial sectional view showing an example of the antenna support pole  1  of a third embodiment of the present invention. The plurality of reinforcement members  20  may include reinforcement members  20   a ,  20   b ,  20   c  having different sizes. In this example, the diameters of the reinforcement members  20   a ,  20   b ,  20   c  increase as the inner diameters of the cylinders  11 ,  12 ,  13  increase. In particular, the sizes of the plurality of arranged reinforcement members  20   a ,  20   b ,  20   c  t may be different from each other in correspondence to regions separated by the fixing portion  30  (in the present example, the filler materials  32   a ,  32   b ). In the present example, the sizes of the plurality of reinforcement members  20   a ,  20   b ,  20   c  arranged in a region  41 , a region  42 , and a region  43  are different from each other. By setting positions of the filler material  32   a  and the filler material  32   b  in accordance with the inner diameters and shapes of the cylinders, the sizes of the reinforcement members  20   a ,  20   b ,  20   c  can be changed in accordance with the inner diameter of the cylinder. Therefore, it is easy to densely arrange the reinforcement members  20   a ,  20   b ,  20   c  in the cylinder. As a result, it is possible to increase the strength of the antenna support pole  1 . Further, the elasticity (rigidity) of each coating layer  24  of the plurality of arranged reinforcement members  20   a ,  20   b ,  20   c  may be different in correspondence to the region separated by the filler material  32   a  and the filler material  32   b . In one example, the reinforcement member  20   a  may be more rigid (less elastic) than the reinforcement member  20   b  and the reinforcement member  20   b  may be more rigid (less elastic) than the reinforcement member  20   c , or vice versa. 
       FIG. 11  is a partial sectional view showing an example of the antenna support pole  1  in a fourth embodiment of the present invention. The plurality of reinforcement members  20  may include reinforcement members  20 ,  21  having different sizes. The reinforcement members  20  and the reinforcement members  21  may be mixed in a region in the cylindrical portion  10 . As shown in  FIG. 11 , the reinforcement members  20 ,  21  are not necessarily arranged in layers, but may be arranged randomly. 
     As shown in  FIG. 11 , the reinforcement members  20  and the reinforcement members  21  having diameters different from each other are mixed in the cylindrical portion  10 , so that the filling rate of the reinforcement members  20 ,  21  in the cylindrical portion  10  can be increased. Therefore, it is easy to densely arrange the reinforcement members  20 ,  21  in the cylinder. As a result, it is possible to increase the strength of the antenna support pole  1 . 
       FIG. 12  is a partial sectional view showing an example of the column body for antenna support in a fifth embodiment of the present invention. As shown in  FIG. 12 , the filler materials  32  filled over the entire inside of the cylindrical portion  10  may be used as the fixing portion  30 . In this case, the filler materials  32  having lower curing speed than polyurea resin may be used. 
       FIG. 13  is a view showing an example of a manufacturing method of the structure of the present invention. In the present example, a manufacturing method of an antenna support pole is shown as an example of the structure. In the present example, the structure includes the main body portion having the hollow configuration surrounding the internal space. The manufacturing method of the structure includes a preparation step (step S 101 ). In the preparation step (step S 101 ), the plurality of reinforcement members  20  are prepared. As shown in  FIG. 4A , the reinforcement member  20  may include the base material  22  formed of foamed synthetic resin and the coating layer  24  which is formed of polyurea resin and which covers the outer surface of the base material  22 . However, the reinforcement member  20  may include the base material  23  formed of fiber reinforced resin and the coating layer  24  which is formed of polyurea resin and which covers the outer surface of the base material  23  as shown in  FIG. 4D , and may include the base material  23  formed of fiber reinforced resin without including the coating layer  24  as shown in  FIG. 4E . 
     The manufacturing method includes a carrying-in step in which a plurality of reinforcement members  20  are carried into the internal space through an opening formed in the main body portion (step S 102 ). For example, taking the cylindrical portion  10  shown in  FIG. 1  as an example, first, the portion of the lightning rod  16  is detached, and one end (upper end) of the cylindrical portion  10  with which the cylinder  13 , the cylinder  12 , and the cylinder  11  communicate is exposed. That is, in the cylindrical portion  10  shown in  FIG. 1 , the opening is arranged at one end of the cylindrical portion  10 , and the portion of the lightning rod  16  functions as a cover portion for closing the opening. Then, using a supply unit  62  for the reinforcement members  20 , a plurality of the reinforcement members  20  is carried into the cylindrical portion  10  from the one end of the cylindrical portion  10 . The carried-in reinforcement members  20  are sequentially arranged from the bottom of the cylindrical portion  10 . 
     The manufacturing method includes a step of arranging the fixing portion  30  for fixing the plurality of reinforcement members  20  into the main body portion. In the present example, the step of arranging the fixing portion  30  includes a filling step of filling, to at least a part of the inside of the cylindrical portion  10 , the filler material  32  for fixing the plurality of reinforcement members  20  into the cylindrical portion  10  (step S 103 ). In the filling step S 103 , the filler material  32  is filled so as to be in contact with at least some reinforcement members  20  among the plurality of reinforcement members  20  and the inner surface of the cylindrical portion  10 . The filler material  32  may be formed of polyurea resin. 
     In one example, when a predetermined amount of the reinforcement members  20  is carried into the cylindrical portion  10 , the carrying-in of the reinforcement members  20  is stopped. Then, the filler material  32   a  is filled through a nozzle  64  or the like inserted into the cylindrical portion  10 . Since the reinforcement members  20  are arranged in the cylindrical portion  10 , the process can be completed in a short period of time as compared with the case in which the space in the cylindrical portion  10  is filled with only the filler material  32   a . Further, unlike the case in which the space in the cylindrical portion  10  is filled with only the filler material  32   a , polyurea resin having relatively low curing speed can be used as the filler material  32   a , and the rigidity of the antenna support pole  1  can be increased. 
     The carrying-in step (step S 102 ) and the filling step (step S 103 ) are repeatedly performed a plurality of times. In other words, the carrying-in step (step S 102 ) is performed before and after the step of arranging the fixing portion  30 , respectively. In the present example, the carrying-in step (step S 102 ) is performed before and after the filling step (step S 103 ), respectively. As a result, the internal space of the main body portion is separated into a plurality of regions. In the present example, the filler materials  32   a ,  32   b  are arranged at a plurality of positions spaced apart from each other in the axial direction of the cylindrical portion  10 . Note that an insertion device inserted into the cylindrical portion  10  may alternately supply the reinforcement members  20  and the filler material  32  at predetermined time intervals. The sizes of the plurality of arranged reinforcement members  20  may be different from each other in correspondence to the separated regions. Further, the elasticity of the coating layer  24  of the plurality of arranged reinforcement members  20  may be different in correspondence to the separated regions. 
     In the carrying-in step S 102 , as shown in  FIGS. 10 and 11 , the reinforcement members  20  having different sizes may be carried into the cylindrical portion  10 . Further, in the carrying-in step S 102 , the plurality of reinforcement members  20  may be arranged in a plurality of layers in the main body portion, or may be arbitrarily filled and arranged without forming layers. For example, the plurality of reinforcement members  20  may be arranged in a plurality of layers in the axial direction of the cylindrical portion  10 . 
     Further, the manufacturing method may include an application step (step S 104 ). The cylindrical portion  10  includes the cylinder  11 , the cylinder  12 , and the cylinder  13 . Each cylinder has the flange portion  14  for connection with the adjacent cylinder. The cylindrical portion  10  is configured with the flange portions  14  of the adjacent cylinders connected to each other. Then, in the application step (step S 104 ), polyurea resin is applied to the outer surface of the cylindrical portion  10  so that polyurea resin covers the pair of connected flange portions  14 . Thus, the external reinforcement portions  52 ,  54  containing polyurea resin are formed on the outer surface of the cylindrical portion  10 . For example, the external reinforcement portions  52 ,  54  containing polyurea resin may be formed through a nozzle  66   a , a nozzle  66   b , or the like arranged toward a side surface of the cylindrical portion  10 . 
     According to the manufacturing method described above, it is possible to manufacture the antenna support pole  1  having enhanced rigidity while using the existing cylindrical portion  10  having been installed in a base station or the like. In other words, the manufacturing method of the present embodiment can also be used as a reinforcing method of the existing antenna support pole  1 . Naturally, the manufacturing method of the present embodiment can also be utilized as a manufacturing method of the antenna support pole  1  which is completely new without using the existing cylindrical portion  10 . 
     The manufacturing method is not limited to the case shown in  FIG. 13 , and various modifications can be adopted. 
       FIG. 14  is a view showing an example of a carrying-in device  90 . The carrying-in device  90  includes a storage tank  91 , a supply pipe  92 , a motor  93 , an alignment supply device  94 , a conveyance pipe  95 , a blower  96 , and a control unit  97 . The reinforcement members  20  stored in the storage tank  91  is supplied through the supply pipe  92  into the conveyance pipe  95  having an inner diameter slightly larger than the reinforcement members  20  by the alignment supply device  94  driven by the motor  93 . Compressed air discharged from the blower  96  flows into the conveyance pipe  95  to convey the reinforcement members  20  in the conveyance pipe  95 . The plurality of reinforcement members  20  may be carried into the internal space of the main body portion using the carrying-in device  90  described above. The control unit  97  controls the blower  96  and the motor  93 . According to the carrying-in device  90  described above, it is possible to increase the number of the reinforcement members  20  to be carried-in in per unit time. Further, since the reinforcement members  20  are fed into the internal space by applying pressure into the conveyance pipe  95 , it is easy to arrange the plurality of reinforcement members  20  at the internal space. In other words, the manufacturing method of the structure of the present invention may further include a pressing step of pressing the plurality of reinforcement members  20  into the internal space, and after the pressing step, the plurality of reinforcement members  20  may be fixed in the main body portion by the fixing portion  30 . Here, means for pressing the plurality of reinforcement members  20  into the internal space is not limited to compressed air. The pressing may be performed by a pressing rod or the like. In particular, when the plurality of reinforcement members  20  are arbitrarily filled and arranged without forming layers, the density of the filled reinforcement members  20  is increased and positioning thereof is performed by the pressing. As a result, the effect of increasing the strength of the structure is increased. 
     In the first to fifth embodiments described above, the filler material  32  is mainly described as the fixing portion  30  for fixing the plurality of reinforcement members  20  into the main body portion. However, the fixing portion  30  is not limited to the filler material  32 . 
       FIG. 15  is a partial sectional view showing an example of the antenna support pole  1  in a sixth embodiment of the present invention. The overall configuration in the sixth embodiment is similar to that in the first embodiment shown in  FIGS. 1 to 8 .  FIG. 15  schematically shows a cross-section of the section A of  FIG. 1  taken along the ZX plane. 
     The main body portion of the antenna support pole  1  includes at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the main body portion. The fixing portion  30  fixes the plurality of reinforcement members  20  into the cylindrical portion  10 . In the present example, the fixing portion  30  includes a connection portion  33  and an extension portion  34 . The fixing portion  30  may be formed of metal or resin. For example, glass fiber reinforced resin (GFRP) or carbon fiber reinforced resin (CFRP) is used as the resin. The connection portion  33  and the extension portion  34  may be integrally formed. The side surface of the connection portion  33  is connected to the inner surface of the hollow configuration. The connection portion  33  may have a plate shape. In one example, the connection portion  33  includes two main surfaces and a side surface which connects the two main surfaces. The side surface of the plate-shaped connection portion  33  may be connected to the inner surface of the hollow configuration. In the present example, the connection portion  33  is connected to the inner surface of the cylindrical portion  10 . In one example, the connection portion  33  may be connected to the inner surface of the hollow configuration by being press-fitted into the hollow configuration, or may be connected to the inner surface of the hollow configuration by an adhesive, welding, or the like. The shape of the connection portion  33  may correspond to the shape of the internal space of the hollow configuration. In one example, the shape of the connection portion  33  may be a disc shape corresponding to the inner diameter shape of the cylindrical portion  10 . The connection portion  33  may separate the internal space into a plurality of regions. In the present example, the inside of the cylindrical portion  10  is separated into a plurality of regions. 
     The extension portion  34  may extend from the main surface of the connection portion  33  along the extension direction of the hollow configuration. When the hollow configuration is the cylindrical portion  10  as in the present example, the extension portion  34  may extend along the axial direction of the cylindrical portion  10 . The extension portion  34  may extend from the vicinity of the center of one main surface of the connection portion  33 . The diameter of the extension portion  34  may be 10% or more and 80% or less of the inner diameter of the cylindrical portion  10 . 
     The inside of the cylindrical portion  10  may be separated into the region  41 , the region  42 , and the region  43  in the axial direction of the cylindrical portion  10 . The three cylinders  11 ,  12 ,  13  are connected to form the cylindrical portion  10 . One fixing portion  30  may be arranged in one cylinder. Taking the region  42  as an example, the extension portion  34   b  of the fixing portion  30   b  is arranged in the cylinder  12 . An end part of the extension portion  34   b  is in contact with the main surface (front surface or back surface) of the connection portion  33   c  of the other adjacent fixing portion  30   c  in the vicinity of the connection region between the cylinder  12  and the cylinder  13 . The plurality of reinforcement members  20  may be arranged in the space between the extension portion  34   b  and the inner surface of the hollow configuration. In the present example, the plurality of reinforcement members  20  are arranged in the space between the extension portion  34   b  and the inner surface of the cylindrical portion  10 . Then, positions of the plurality of reinforcement members  20  are fixed by the connection portion  33   b , the connection portion  33   c , the extension portion  34   b , and the inner surface of the cylindrical portion  10  (hollow configuration). 
     According to the structure of the present example, since the extension portion  34  is arranged, the number of the reinforcement members  20  required to be arranged at the internal space can be reduced. In the present example, the rigidity of the cylindrical portion  10  can be increased while reducing the number of the reinforcement members  20  arranged in the cylindrical portion  10 . 
       FIG. 16  is a partial sectional view showing an example of the antenna support pole  1  in a seventh embodiment of the present invention. In the sixth embodiment shown in  FIG. 15 , description has been provided on the case in which one fixing portion  30  is arranged in one cylinder, but the present invention is not limited thereto. As shown in  FIG. 16 , a plurality of fixing portions  30   b ,  30   c  may be arranged in one cylinder  12 . The fixing portion  30   b  is arranged at a position closer to the vicinity of the connection region between the cylinder  12  and the cylinder  11  than the fixing portion  30   c . In contrast, the fixing portion  30   c  is arranged at a position closer to the vicinity of the connection region between the cylinder  12  and the cylinder  13  than the fixing portion  30   b.    
     The fixing portion  30   b  includes a connection portion  33   b  arranged in the vicinity of the connection region between the cylinder  12  and the cylinder  11 , and an extension portion  34   b  extending from the connection portion  33   b . The fixing portion  30   c  includes a connection portion  33   c  arranged in the vicinity of the center portion in the longitudinal direction of the cylinder  12 , and an extension portion  34   c  extending from the connection portion  33   c . According to the present embodiment as well, the rigidity of the cylindrical portion  10  can be increased while reducing the number of the reinforcement members  20  arranged in the cylindrical portion  10 . 
     In the example shown in  FIGS. 15 and 16 , the fixing portion  30  includes the connection portion  33  and the extension portion  34 , but the fixing portion  30  may include the connection portion  33  without including the extension portion  34 . In this case, the connection portions  33  may be metal plates which cover ends of the cylinders  11 ,  12 ,  13 . 
       FIG. 17  is a sectional view showing an example of the antenna support pole  1  in an eighth embodiment of the present invention. In  FIG. 17 , an opening is arranged at a part of the cylindrical portion  10 . In the present example, the opening is arranged at the top end of the cylindrical portion  10 . Then, the main body portion of the cylindrical portion  10  includes a cover portion  55  which closes the opening. In the present example, the cover portion  55  is connected to a flange portion  14   f . By closing the opening with the cover portion  55 , the plurality of reinforcement members  20  are fixed into the main body portion. Thus, in the present example, the cover portion  55  functions as the fixing portion  30 . The cover portion  55  is, for example, a metal plate. The lightning rod  16  or the like may be attached to the cover portion  55 . In the present example, the filler material  32  may not be arranged as the fixing portion  30 . In the present example as well, the configurations of the external reinforcement portions  51 ,  52 ,  54  and the like are similar to those of the first embodiment shown in  FIG. 3 . 
     According to the present example, since the cover portion  55  functions as the fixing portion  30 , construction is facilitated when manufacturing the antenna support pole  1  or the like using the existing pipe. 
     In the first to eighth embodiments, description has been provided mainly on the case in which the reinforcement member  20  has a spherical shape. However, the shape of the reinforcement member  20  is not limited to the spherical shape. 
       FIG. 18  is a view showing another example of the reinforcement member  20 . As shown in  FIG. 18 , the reinforcement member  20  may have a polyhedral shape. In the example shown in  FIG. 18 , the reinforcement member  20  has a regular tetrahedron shape, but the shape of the reinforcement member  20  is not limited to the regular tetrahedron shape. The reinforcement member  20  shown in  FIG. 18  may also include the base material  22  and the coating layer  24  which covers the outer surface of the base material  22 . The base material  22  may have a polyhedron shape corresponding to the shape of the reinforcement member  20 . 
       FIG. 19  is a view showing another example of the reinforcement member  20 . As shown in  FIG. 19 , the reinforcement member  20  may have a columnar shape. In the example shown in  FIG. 19 , the reinforcement member  20  has a regular hexagonal prism shape. The regular hexagonal prism having a regular hexagonal bottom surface can be most densely arranged in the plane. However, not limited to the regular hexagonal prism shape, the reinforcement member  20  may be another polygonal prism or it may be a column. The reinforcement member  20  shown in  FIG. 18  may also include the base material  22  and the coating layer  24  which covers the outer surface of the base material  22 . The base material  22  may have a columnar shape corresponding to the shape of the reinforcement member  20 . 
     Owing to that the reinforcement members  20  each having a shape other than a spherical shape, as shown in  FIG. 18  or  FIG. 19 , are arranged in the hollow configuration, a virtual frame structure is formed in the hollow configuration due to the coating layers  24  each covering the outer surfaces of the reinforcement members  20 . Therefore, according to the reinforcement members  20 , the strength of the hollow configuration can be increased from the inside. In the case in which the reinforcement member  20  has a columnar shape or a polyhedral shape, the maximum size of the shape may be one time or more and 20 times or less, or one time or more and 10 times or less of the maximum size of the cross-section of the hollow configuration taken perpendicularly to the axial direction. When the reinforcement member  20  has a columnar shape or a polyhedral shape, the maximum size of the shape may be 10 mm or more. 
     Also in the reinforcement member  20  shown in  FIGS. 18 and 19 , as described with reference to  FIGS. 4D and 4E , the base material  23  formed of fiber reinforced resin (FRP) may be employed instead of the base material  22  formed of foamed synthetic resin. In the case in which the reinforcement member  20  includes the base material  23  formed of fiber reinforced plastic (FRP), the coating layer  24  which covers the outer surface of the base material  23  may be omitted. 
       FIG. 20  is a view for explaining conditions of a simulation test. As the cylinder  12 , a cylinder having an outer diameter of 190.7 mm, an inner diameter of 180.1 mm, and a length of 2.3 m was used. The reinforcement member  20  of a plurality of spherical shapes were arranged inside the cylinder  12 , so as to form a layer configuration shown in  FIGS. 5 and 6 . In the vicinity of one end and the other end of the cylinder  12 , the filler material  32   a  and the filler material  32   b  were arranged as the fixing portions  30 , and positions of the spherical reinforcement members  20  were fixed. The thickness of the filler material  32   a  and the filler material  32   b  in the axial direction (Z-axis direction) was about 30 mm. 
     The spherical reinforcement member  20  having a diameter of 48 mm was used. Specifically, the reinforcement member  20  which includes the base material  22  having a diameter of 40 mm and the coating layer  24  formed of polyurea resin having a film thickness of 4 mm was used. The external reinforcement portion  52  which covers the flange portion  14   c  and the ribs  15   c  at one end of the cylinder  12  was arranged. The external reinforcement portion  52  has a film thickness of 4 mm, and a part thereof extends along the side surface of the cylinder  12 . Similarly, the external reinforcement portion  54  which covers the flange portion  14   d  and the ribs  15   d  at the other end of the cylinder  12  was arranged. The external reinforcement portion  54  has a film thickness of 4 mm, and a part thereof extends along the side surface of the cylinder  12 . 
     On the other hand, as a comparative example, a simulation test was also performed on a support pole having a similar configuration except that the reinforcement members  20 , the filler materials  32   a ,  32   b , the external reinforcement portion  52 , and the external reinforcement portion  54  were not arranged. 
     In the simulation test, a force of 10000 (N) was applied in the X-axis direction from the side surface at the upper end (top end) of the cylinder  12 . As a result, it was found that the maximum stress was applied to the rib  15   c  arranged at the lower end (base end) of the cylinder  12 , as shown by the point P in  FIG. 20 , in both the present example and the comparative example. In the present example, the maximum stress at the rib  15   c  was 156.1 (N/mm 2 ). On the other hand, in the comparative example, the maximum stress at the ribs  15   c  was 249.7 (N/mm 2 ). From the results described above, it was found that the stress concentration on the ribs  15   c  was alleviated by arranging the reinforcement members  20 , the filler material  32   a , the filler material  32   b , the external reinforcement portion  52 , and the external reinforcement portion  54  as in the present example. Similar effects were obtained as well in the cylinder  11  and the cylinder  13 . 
     In the following, the simulation results are verified. The height h of the antenna support pole  1  is 2.3 m, the outer diameter D 1  thereof is 190.7 mm, and the inner diameter D 2  thereof is 180.1 mm. When a force of F (N) is applied in the X-axis direction from the side surface at the upper end of the antenna support pole  1 , the action moment M applied to the bottom surface of the antenna support pole  1  is obtained as M=F·h=23000 (N·m). The stress σ at the bottom surface is given by σ=M/Z. Here, Z is a sectional coefficient and given by Z=I(moment of inertia)/e(distance of the center of gravity). Assuming that I=(π(D 1   4 −D 2   4 )/64)/(D 1 /2)=1328 (cm 4 ) and e=14.4 (mm), Z=1328/14.4=92.2 (cm 3 ) is obtained. From the above, the stress is obtained as σ=M/Z=23000/92.2=250 (N/mm 2 ). Next, assuming that the inner diameter is equivalently decreased by arranging the reinforcement members  20 , the filler material  32   a , the filler material  32   b , the external reinforcement portion  52 , and the external reinforcement portion  54 , and D 2 =172.7 (mm), similar calculation provides the followings:
         I=2125.4 (cm 4 );   e=14.4 (mm);   Z=147.6; and   σ=M/Z=23000/147.6=156 (N/mm 2 ).       

     The above agrees with the measurement results. That is, the thickness of the member of the antenna support pole  1 , which is 5.3 mm (=(190.7−180.1)/2) without implementing the present invention, is equivalent to 9 mm (=(190.7−172.7)/2), which is equivalently increased by 3.7 mm. 
     Since the reinforcement members  20  coated with polyurea resin are arranged in the cylindrical portion  10 , the rigidity of the cylindrical portion  10  can be increased, and the displacement of the cylindrical portion  10  can be suppressed, so that the stress generated at the point P is suppressed. Further, by arranging the external reinforcement portions  52 ,  54 , a portion where stress is likely to increase is coated from the outside, and thus stress to be generated is suppressed. 
     Further, a three-point bending test was performed using a cylinder having an outer diameter of 190.7 mm, an inner diameter of 180.1 mm, a thickness of 5.3 mm, and a length of 800 mm. Two receiving round rods were separated by a center-to-center distance of 600 mm, and a sample was placed thereon. Then, the middle point of the center-to-center distance 600 mm of the two receiving round rods were pushed by a pushing round rod, and breaking load was measured. The receiving round rods and the pushing round rod were 50 mm in diameter. As a result, by arranging, at the internal space of the cylinder, the reinforcement members  20  of a diameter of 40 mm, including the base material  22  formed of foamed synthetic resin and the coating layer  24  which covers the outer surface of the base material  22 , the breaking load (N) was increased by about 15% compared with the case in which the reinforcement members  20  were not arranged. In the case in which the reinforcement members  20  were arranged in the internal space of the cylinder through the pressing step of pressing the plurality of reinforcement members  20  at the internal space, the breaking load (N) was higher by about 20% compared with the case in which the reinforcement members  20  were not arranged. 
     Further, in the simulations, when the reinforcement members  20  each having a diameter of 40 mm or 20 mm including the base material  23  of glass fiber reinforced resin (GFRP) or carbon fiber reinforced resin (CFRP) were arranged in the internal space of the cylinder (see  FIG. 4D  and  FIG. 4E ), although affected by the rigidity of the cylinder itself, the displacement amount was reduced by 23.8% as compared with the case in which the reinforcement members  20  each having a diameter of 40 mm including the base material  22  formed of foamed synthetic resin and the coating layer  24  which covers the outer surface of the base material  22  were arranged at the internal space of the cylinder. 
     Further, in the simulations, when the reinforcement members  20  formed of glass fiber reinforced resin (GFRP) or carbon fiber reinforced resin (CFRP) were arranged and fixed in the cylinder and the external reinforcement portion  52  was arranged, the rigidity was improved by 17.8% compared with the case in which the reinforcement members  20  and the external reinforcement portion  52  were not arranged. At this time, the stress applied to the base end was reduced by about 65%. Further, the effects of rigidity improvement and stress reduction were confirmed to the same extent in an actual antenna support pole in which the cylindrical portion  10  is configured by connecting the three cylinders  11 ,  12 ,  13 . 
     Although description has been provided on the antenna support pole  1 , the configuration of the cylindrical portion  10  is not limited to the example shown in  FIG. 1 . In the above description of the first to eighth embodiments, the reinforcement members  20  or the filler materials  32   a ,  32   b  are arranged at the internal space of the cylindrical portion  10  in the region from the base end to the top end of the cylindrical portion  10 . Specifically, description has been provided on the case in which the reinforcement members  20  are arranged at the internal space of the cylindrical portion  10  in the region from the base end to the top end of the cylindrical portion  10  except for the region filled with the filler materials  32   a ,  32   b . However, the present invention is not limited thereto. 
       FIG. 21  is a view showing a modification example of the antenna support pole  1 . As shown in  FIG. 21 , in the axial direction of the cylindrical portion  10  (Z-axis direction), a plurality of reinforcement members  20  are arranged in a partial region at the base end (−Z side end). Except for the partial region at the base end, the reinforcement members  20  are not arranged at the internal space of the cylindrical portion  10 . According to the simulation results under the conditions shown in  FIG. 20 , the maximum stress is applied to the ribs  15   a  arranged at the base end of the cylindrical portion  10  (the lower end). Therefore, the partial region at the base end is arranged so as to correspond to the portion where the maximum stress is applied in the axial direction of the cylindrical portion  10  (Z-axis direction). Assuming that the length of the cylindrical portion  10  is L, the partial region at the base end may be in the range of L/3 or in the range of L/5 from the end of the base end of the cylindrical portion  10 . 
     In the modification example shown in  FIG. 21 , the cylindrical portion  10  includes the plurality of cylinders  11 ,  12 ,  13 . Among the plurality of cylinders  11 ,  12 ,  13 , the cylinder  11  is arranged at a position closest to the base end of the cylindrical portion  10 , the cylinder  13  is arranged at a position closest to the top end of the cylindrical portion  10 , and the cylinder  12  is arranged between the cylinder  11  and the cylinder  13 . In the present modification example, the reinforcement members  20  are arranged at the internal space of the cylinder  11  arranged at the position closest to the base end of the cylindrical portion  10  among the plurality of cylinders  11 ,  12 ,  13 . 
     The present modification example includes at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the cylindrical portion  10  in a partial region at the base end. In the present modification example, the fixing portion  30  includes the filler materials  32   a ,  32   b . The filler materials  32   a ,  32   b  are filled in at least a part of the inside of the hollow configuration so as to be in contact with at least some reinforcement members  20  among the plurality of reinforcement members  20  and an inner surface of the hollow configuration. 
     In the present modification example, the plurality of filler materials  32   a ,  32   b  are formed as the filler material  32 . The filler material  32   a  is arranged at a position closer to the base end than the filler material  32   b . The positions of the plurality of reinforcement members  20  may be fixed by sandwiching the plurality of reinforcement members  20  between the filler material  32   a  and the filler material  32   b  in the axial direction of the cylindrical portion  10 . 
     According to the present modification example, in the region at the base end, the plurality of reinforcement members  20  are arranged at the internal space of the cylindrical portion  10 . Therefore, it is possible to effectively increase the rigidity of the cylindrical portion  10 . Further, since the plurality of reinforcement members  20  are arranged in a concentrated manner in the partial region at the base end, it is possible to reduce the use amount of the plurality of reinforcement members  20 , and shorten the carrying-in step of carrying the plurality of reinforcement members  20  into the cylindrical portion  10 . 
       FIG. 22  is a view showing a modification example of the column body for antenna support. The cylindrical portion  10  includes the plurality of cylinders  11 ,  12 ,  13 . In the axial direction of the cylindrical portion  10  (Z-axis direction), the plurality of reinforcement members  20  are arranged in a partial region at the base end of each of the cylinders  11 ,  12 ,  13 . In the axial direction of the cylindrical portion  10  (Z-axis direction), the plurality of reinforcement members  20  are arranged in the partial region at the base end (−Z side end) of the cylinder  11 . Except for the partial region at the base end, the reinforcement members  20  are not arranged at the internal space of the cylinder  11 . Similarly, the plurality of reinforcement members  20  are arranged in the partial region at the base end (−Z side end) of the cylinder  12 . The plurality of reinforcement members  20  are arranged in the partial region at the base end of the cylinder  13 . Assuming that the length of the cylinder  11  is L, the partial region at the base end may be in the range of L/3 or in the range of L/5 from the end of the base end of the cylinder  11 . The partial regions at the base ends of the cylinder  12  and the cylinder  13  may be the same as in the case of the cylinder  11 . 
     The present modification example includes at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the cylinder  11  in the partial region at the base end of the cylinder  11 . In the present modification example, the fixing portion  30  includes the filler materials  32   a ,  32   b . The filler materials  32   a ,  32   b  are filled in at least a part of the inside of the hollow configuration so as to be in contact with at least some reinforcement members  20  among the plurality of reinforcement members  20  and an internal surface of the hollow configuration. 
     In the present modification example, in the cylinder  11 , the filler material  32   a  is arranged at a position closer to the base end of the cylinder  11  than the filler material  32   b . The plurality of reinforcement members  20  may be fixed in the cylinder  11  by sandwiching the plurality of reinforcement members  20  between the filler material  32   a  and the filler material  32   b  in the axial direction of the cylindrical portion  10 . 
     Similarly, in the cylinder  12 , the filler material  32   c  is arranged at a position closer to the base end of the cylinder  12  than a filler material  32   d . The plurality of reinforcement members  20  may be fixed in the cylinder  12  by sandwiching the plurality of reinforcement members  20  between the filler material  32   c  and the filler material  32   d  in the axial direction of the cylindrical portion  10 . Similarly, in the cylinder  13 , a filler material  32   e  is arranged at a position closer to the base end of the cylinder  13  than a filler material  32   f . The plurality of reinforcement members  20  may be fixed in the cylinder  13  by sandwiching the plurality of reinforcement members  20  between the filler material  32   e  and the filler material  32   f  in the axial direction of the cylindrical portion  10 . 
     According to the present modification example, even in the case in which a plurality of cylinders are connected, the plurality of reinforcement members  20  are arranged at the internal space of each of the cylinders  11 ,  12 ,  13  in the region at the base end of each of the cylinders  11 ,  12 ,  13 . Therefore, it is possible to effectively increase the rigidity of the cylindrical portion  10 . Further, since the plurality of reinforcement members  20  are arranged in a concentrated manner in the partial region at the base end of each of the cylinders  11 ,  12 ,  13 , it is possible to reduce the use amount of the plurality of reinforcement members  20 , and shorten the carrying-in step of carrying the plurality of reinforcement members  20  into the cylindrical portion  10 . 
       FIG. 23  is a view showing a modification example of the column body for antenna support. In the first to eighth embodiments, the cylindrical portion  10  is arranged with the cylinder  11 , the cylinder  12 , and the cylinder  13  having different diameters communicating with each other. However, the present invention can also be applied to the antenna support pole  1  having the cylindrical portion  10  including one cylinder instead of a plurality of cylinders as shown in  FIG. 23 . 
       FIG. 24  is a view showing a modification example of the column body for antenna support. In the first to eighth embodiments, the inner diameter and the outer diameter of each of the cylinder  11 , the cylinder  12 , and the cylinder  13  having different diameters are constant regardless of the position in the axial direction, but the present invention is not limited thereto. At least one of the cylinder  11 , the cylinder  12 , and the cylinder  13  may be configured such that the diameter thereof is decreased toward the positive direction (upward) along the Z-axis direction. In the present example, in each of the cylinders  11 ,  12 ,  13 , the diameter thereof is decreased toward the positive direction (upward) along the Z-axis direction. The present invention can be applied to such a variety of cylindrical portions  10 . 
       FIG. 25  is a view showing an example of a power pole  4  for power transmission. The power pole  4  is another example of the column body which is the structure of the present invention. The power pole  4  has the cylindrical portion  10  formed of concrete and steel frame or the like. Therefore, the rigidity can be enhanced by supplying the reinforcement members  20  from the opening  72  at the end of the cylindrical portion  10  and arranging and fixing the reinforcement members  20  in the cylindrical portion  10 . The configurations of the reinforcement members  20  and the fixing portion  30  may be the same as those described with reference to  FIGS. 1 to 24 . Therefore, detailed description thereof will be omitted. 
       FIG. 26  is a view showing an example of a street lamp pole  6 . The street lamp pole  6  is another example of the column body which is the structure of the present invention. The street lamp pole  6  is provided with a street lamp. The street lamp pole  6  has the cylindrical portion  10  formed of metal. Therefore, the rigidity can be enhanced by supplying the reinforcement members  20  from the opening  82  at the end of the cylindrical portion  10  and arranging and fixing the reinforcement members  20  in the cylindrical portion  10 . The configurations of the reinforcement members  20  and the fixing portion  30  may be the same as those described with reference to  FIGS. 1 to 24 . Therefore, detailed description thereof will be omitted. In particular, in the street lamp pole  6 , the rigidity of the cylindrical portion  10  is low as compared with the antenna support pole  1 . Therefore, even when the reinforcement members  20  each including the base material  22  formed of foamed synthetic resin as shown in  FIG. 4A  is used, the effect of sufficiently improving rigidity can be obtained. 
     In the above, description has been provided on the case in which the structure of the present invention is a cylindrical body including the cylindrical portion  10 . However, the structure of the present invention is not limited to the case of the cylindrical body. The structure of the present invention may be configured with the plurality of reinforcement members  20  as described above arranged in the main body portion of the structure. 
       FIG. 27  is a perspective view showing an example of a structure  100  in a ninth embodiment of the present invention. The structure  100  includes a main body portion  101 . In the present example, the main body portion  101  has a hollow configuration surrounding an internal space. In the present example, the main body portion  101  has a rectangular parallelepiped shape, but the main body portion  101  is only required to have a hollow configuration and is not limited to a rectangular parallelepiped shape. 
     The main body portion  101  may include an outer shell portion  102  and a cover portion  104 . The cover portion  104  closes an opening formed at a part of the outer shell portion  102  of the main body portion  101 . The main body portion  101  may be formed of at least one material selected from the group consisting of metal, ceramic, wood, and resin. The outer shell portion  102  and the cover portion  104  of the main body portion  101  may be formed of the same material, or may be formed of different materials. The outer shell portion  102  and the cover portion  104  may be joined by welding or the like. Further, the outer shell portion  102  may be configured of a plurality of components as a first outer shell portion and a second outer shell portion. In this case, the hollow configuration is formed by joining the plurality of components to each other by welding or the like. The cover portion  104  may also serve as at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the main body portion  101 . In this case, only with the cover portion  104  of the main body portion  101 , the fixing portion  30  is not required to be separately arranged. 
       FIG. 28  is a sectional view showing an example of a cross-section of the structure  100  shown in  FIG. 27 . The structure  100  includes a plurality of reinforcement members  20  arranged in the main body portion  101 . In the present example, the main body portion  101  has a hollow configuration surrounding an internal space thereof. The plurality of reinforcement members  20  are arranged at the internal space. 
     The main body portion  101  includes at least one fixing portion  30  which fixes the plurality of reinforcement members  20  into the main body portion  101 . In the present example, the fixing portion  30  may be a filler material which is filled in at least a part of the inside of the hollow configuration so as to be in contact with at least some reinforcement members  20  among the plurality of reinforcement members  20  and an inner surface of the hollow configuration. The filler material may be similar to the filler material  32  described in the first to fifth embodiments shown in  FIGS. 1 to 12 . Therefore, detailed description of the filler material will be omitted. On the other hand, as described with reference to  FIGS. 15 and 16 , the fixing portion  30  may include a connection portion having a side surface connected to an inner surface of the hollow configuration and an extension portion extending from a main surface of the connection portion along an extension direction of the hollow configuration. The connection portion and the extension portion may be similar to the connection portion  33  and the extension portion  34  in  FIGS. 15 and 16 . The extension direction of the hollow configuration may be a direction intersecting with the main surface of the connection portion. 
     In the present example, the space  25  between the adjacent reinforcement members  20  at the internal space may be unfilled except for the region filled with the filler material. The configuration of the structure  100  of the present example may be similar to the configuration in the first to eighth embodiments described with reference to  FIGS. 1 to 26  except that the hollow configuration of the structure  100  is not the cylindrical portion  10 . Therefore, description thereof will not be repeated. 
     The manufacturing method of the structure  100  of the present embodiment includes a preparation step, a carrying-in step, and a step of arranging the fixing portion  30  for fixing the plurality of reinforcement members  20  into the main body portion  101 . In the preparation step, the plurality of reinforcement members  20  are prepared. In the carrying-in step, the plurality of reinforcement members  20  are carried into the internal space from the opening arranged in the main body portion  101 . The step of arranging the fixing portion  30  may include a filling step. In the filling step, the filler material for fixing the plurality of reinforcement members  20  into the main body portion  101  may be filled into at least a part of the internal space. The opening may be blocked by the cover portion  104 . The outer shell portion  102  and the cover portion  104  may be joined by welding or the like. Here, the manufacturing method of the structure  100  may not necessarily include the filling step. The positions of the plurality of reinforcement members  20  may be fixed by blocking the opening with the cover portion  104  which functions as the fixing portion  30 . 
     As in the present embodiment, even when the structure  100  is not a cylindrical body, the rigidity of the hollow configuration can be enhanced. By arranging the plurality of reinforcement members  20  at the internal space of the main body portion  101  having the hollow configuration, the coating layer  24  formed of polyurea resin generates the similar configuration as a mesh configuration in the internal space. Thus, it is considered that the rigidity of the structure  100  is increased. Here, the coating layer  24  formed of polyurea resin may be omitted, and the plurality of reinforcement members  20  each including the base material formed of fiber reinforced resin (FRP) may be arranged at the internal space of the structure  100 . 
       FIG. 29  is a sectional view showing an example of the structure  100  in a tenth embodiment of the present invention. In the ninth embodiment shown in  FIGS. 27 and 28 , description has been provided on the case in which the main body portion  101  includes the outer shell portion  102 , the cover portion  104 , and the fixing portion  30 , but the present invention is not limited thereto. As shown in  FIG. 29 , the cover portion  104  may not be arranged. In the present example, the fixing portion  30  closes the opening of the main body portion  101 . The fixing portion  30  is, for example, the filler material formed of polyurea resin. 
       FIG. 30  is a sectional view showing an example of the structure  100  in an eleventh embodiment of the present invention. The upper stage of  FIG. 30  shows a state before the outer shell portion  102  is arranged, and the lower stage of  FIG. 30  shows a state after the outer shell portion  102  is arranged. 
     In the present embodiment, the main body portion  101  may include at least one material selected from the group consisting of metal, ceramic, wood, and resin. The outer shell portion  102  of the main body portion  101  has a hollow configuration surrounding the internal space. The main body portion  101  has a foamed synthetic resin  26  at the internal space. The plurality of reinforcement members  20  are embedded in the foamed synthetic resin  26  at the internal space. In other words, a region other than the plurality of reinforcement members  20  at the internal space is filled with the foamed synthetic resin  26 . 
     The manufacturing method of the structure  100  of the present embodiment may include a preparation step and a step of forming the main body portion  101 . In the preparation step, the plurality of reinforcement members  20  are prepared. The reinforcement members  20  may be similar to those in the first to tenth embodiments. The manufacturing method includes the step of forming the main body portion  101  by molding a material of the main body portion  101  such that the plurality of reinforcement members  20  are embedded therein. In the present example, the main body portion  101  may be formed such that the plurality of reinforcement members  20  are embedded in the foamed synthetic resin  26  (foamed synthetic resin for the main body portion) forming a part of the main body portion  101 . Specifically, a technique of insert molding may be used. Note that, instead of the foamed synthetic resin  26 , other resin, concrete, or the like may be used as a material arranged at the internal space. 
     Then, after the foamed synthetic resin  26  for the main body portion  101  is molded, the outer surface of the molded foamed synthetic resin  26  is covered with the outer shell portion  102 . The manufacturing method of the structure  100  in the present example may include a main body portion application step of applying polyurea resin to the outside of the foamed synthetic resin  26  for the main body portion  101 . Thus, the outer shell portion  102  can be formed of polyurea resin. Here, the outer shell portion  102  may be formed by a method other than applying. In one example, the outer shell portion  102  may be configured of a plurality of components as a first outer shell portion and a second outer shell portion. The first outer shell portion and the second outer shell portion may be joined with a method such as welding in a state in which the molded foamed synthetic resin  26  is sandwiched between the first outer shell portion and the second outer shell portion. 
     According to the present example, it is possible to omit the carrying-in step of carrying the plurality of reinforcement members  20  into the internal space. Further, when the outer shell portion  102  is formed by applying polyurea resin to the outside of the foamed synthetic resin  26  for the main body portion  101 , it is not necessary to arrange the opening for carrying-in the plurality of reinforcement members  20  to the internal space of the main body portion  101 , and it is not necessary to arrange the cover portion  104  for closing the opening. Therefore, it is possible to improve the sealing property of the structure  100 . Since the outer shell portion  102  can be formed of polyurea resin, it is possible to realize the structure  100  which is excellent in weight reduction and corrosion resistance. 
     The structure  100  may not necessarily have a hollow configuration. The present invention is simply required to have a configuration in which the plurality of reinforcement members  20  are arranged as each including the base material  22  described above and the coating layer  24  formed of polyurea resin and the plurality of reinforcement members  20  are arranged in the main body portion  101 , and is not necessarily limited to the structure  100  having a hollow configuration. 
       FIG. 31  is a sectional view showing an example of the structure  100  in a twelfth embodiment of the present invention. In the present example, the main body portion  101  does not include the outer shell portion  102  and the cover portion  104 . The main body portion  101  is formed by molding a material  27  of the main body portion  101  into the shape of the main body portion  101 . The material  27  of the main body portion  101  may be resin or concrete. The plurality of reinforcement members  20  are embedded in the material  27  of the main body portion  101 . 
     The manufacturing method of the structure  100  of the present embodiment may be similar to the preparation step and the step of forming the main body portion  101  in the eleventh embodiment shown in  FIG. 30 . The manufacturing method may include the step of forming the main body portion  101  by molding the material  27  of the main body portion  101  such that the plurality of reinforcement members  20  are embedded therein. 
     In the present example as well, unlike the case in which the structure  100  is configured only by the main body portion  101 , the plurality of reinforcement members  20  each including polyurea resin as the coating layer  24  are arranged in the main body portion  101 , so that the rigidity of the structure  100  can be increased. 
     The structures  100  shown in the ninth to twelfth embodiments shown in  FIGS. 27 to 31  can be used for various products. Examples in which the structures  100  are used for various products will be described below. 
       FIG. 32  is a perspective view showing an example of a pallet  210  in a thirteenth embodiment of the present invention. The pallet  210  is an example of the structure  100 . The pallet  210  allows articles to be placed thereon. The pallet  210  is used, for example, in physical distribution, and is used for storing and transporting articles. 
     The pallet  210  of the present example includes a pallet main body  211  and a plurality of legs  216 . The pallet main body  211  of the present example has a plate shape. In the pallet main body  211 , a surface on which an article is placed is referred to as a placement surface  212 , and a surface opposite to the placement surface  212  is referred to as a back surface  214 . 
     The plurality of legs  216  are arranged on the back surface  214 . The plurality of legs  216  may be formed integrally with the pallet main body  211  or may be bonded to the pallet main body  211 . The respective legs  216  are arranged at predetermined intervals. It is preferable that the legs  216  are arranged in a grid manner so that a fork of a forklift or the like can pass between the legs  216 . 
       FIG. 33  is a view showing a partial cross-section of the pallet  210  shown in  FIG. 32 .  FIG. 33  shows a cross-section of a part of the main body portion  101 . The pallet  210  may include the main body portion  101 . Specifically, the main body portion  101  may include the outer shell portion  102  formed of a material selected from the group consisting of metal, ceramic, wood, and resin. The outer shell portion  102  may be formed of polyurea resin. The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102 . The plurality of reinforcement members  20  each include the base material  22  and the coating layer  24 . The space  25  may be filled with foamed synthetic resin or may not be filled. Other configurations of the pallet  210  of the present embodiment may be similar to those of any structure  100  of the eighth to eleventh embodiments shown in  FIGS. 27 to 31 . 
       FIG. 34  is a perspective view showing an example of a box body  220  in a fourteenth embodiment of the present invention. The box body  220  has a storage space  226 . The box body  220  of the present example has a storage portion  224  and a lid portion  222 . A recess serving as the storage space  226  is formed in the storage portion  224 . The lid portion  222  is placed on the storage portion  224  to seal the storage space  226 . It is also possible that the lid portion  222  is fixed to the storage portion  224  by a part of the lid portion  222  being inserted to the storage space  226 . The box body  220  is used as, for example, a cold insulation box for storing fresh food and the like, but the use application of the box body  220  is not limited thereto. Other configurations of the box body  220  of the present embodiment may be similar to those of any of the structures  100  in the ninth to twelfth embodiments shown in  FIGS. 27 to 31 . 
       FIG. 35  is a view showing a partial cross-section of the lid portion  222  and the storage portion  224  shown in  FIG. 34 . Similarly to the pallet  210  shown in  FIG. 33 , the lid portion  222  and the storage portion  224  may each include the main body portion  101 . Specifically, the main body portion  101  may include the outer shell portion  102  formed of a material selected from the group consisting of metal, ceramic, wood, and resin. In particular, the outer shell portion  102  may be formed of polyurea resin. The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102 . The plurality of reinforcement members  20  each include the base material  22  and the coating layer  24 . The space  25  may be filled with foamed synthetic resin or may not be filled. Other configurations of the box body  220  of the present embodiment may be similar to those of any of the structures  100  in the ninth to twelfth embodiments shown in  FIGS. 27 to 31 . 
       FIG. 36  is a view showing an example of an airframe  230  of an aircraft in a fifteenth embodiment of the present invention. The aircraft may be a manned or unmanned aircraft. The airframe  230  of the aircraft is an example of the structure  100 . In the present example, a main wing portion is shown as the airframe  230 . The airframe  230  may include upper and lower outer shell portions  102  as the main body portion  101 . The main body portion  101  is formed by joining the upper and lower outer shell portions  102 . Beam portions  232  and rib portions  234  may be arranged at the internal space of the main body portion  101 . The plurality of reinforcement members  20  are arranged at the internal space. The plurality of reinforcement members  20  each include the base material  22  and the coating layer  24 . The plurality of reinforcement members  20  may be fixed to the main body portion  101  by a filler material. 
       FIG. 37  is a view showing an example of a component of a vehicle in a sixteenth embodiment of the present invention. In the present example, a bumper  240  is shown as a component of a vehicle. The bumper  240  of the present example may include an impact absorbing portion  241  for absorbing an impact, a beam portion  242 , and an attachment portion  243 . The impact absorbing portion  241  may include an exterior portion  244  and a resin material  245 . The exterior portion  244  and the resin material  245  may be integrally formed. 
     The beam portion  242  of the bumper  240  of the vehicle is an example of the structure  100 . The beam portion  242  includes the main body portion  101 . The main body portion  101  has a hollow configuration surrounding an internal space thereof. The main body portion  101  may include an outer shell portion  102  formed of a material selected from the group consisting of metal, ceramic, wood, and resin. In the present example, the outer shell portion  102  is formed in a cylindrical shape having a rectangular cross-section. The plurality of reinforcement members  20  are arranged at the internal space. 
     The beam portion  242  may be arranged along the rear side of the impact absorbing portion  241 . The beam portion  242  and the impact absorbing portion  241  may be connected to each other. The attachment portion  243  is arranged at the beam portion  242 . The bumper  240  may be connected to the frame of the vehicle via the attachment portion  243 . 
     In the example of  FIG. 37 , description has been provided on the case of applying the structure of the present invention to the beam portion  242 , but the present invention is not limited thereto. In one example, the structure of the present invention may be applied as well to the impact absorbing portion  241 . The structure of the present invention can be applied not only to the bumper  240  but also to various components such as exterior components or interior components of a vehicle such as an automobile or a train. 
       FIG. 38  is a view showing an example of a scaffold plank  250  for construction in a seventeenth embodiment of the present invention.  FIG. 38  also shows a partially enlarged cross-section of a side surface portion of the scaffold plank  250  for the sake of description. The scaffold plank  250  is an example of the structure  100 . The scaffold plank  250  has the main body portion  101 . The main body portion  101  may include an outer shell portion  102  formed of a material selected from the group consisting of metal, ceramic, wood, and resin. In particular, the outer shell portion  102  may be a polyurea resin layer. The outer shell portion  102  is formed in a cylindrical shape having a rectangular cross-section. The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102 . At the internal space, a region other than the plurality of reinforcement members  20  may be filled with the foamed synthetic resin  26 . 
     The manufacturing method of the scaffold plank  250  of the present embodiment may be similar to the manufacturing method of the structure in  FIG. 30 . The manufacturing method may include the step of forming the main body portion  101  by molding a material of the main body portion  101  such that the plurality of reinforcement members  20  are embedded therein. The manufacturing method may include a main body portion application step of applying polyurea resin on the outer surface of the molded foamed synthetic resin  26  for the main body portion  101  after the foamed synthetic resin  26  is molded. Thus, the outer shell portion  102  can be formed of polyurea resin. 
     To secure the scaffold plank  250  to an external scaffolding structure, both ends of the scaffold plank  250  may be provided with hook members  252  formed of metal or reinforced plastic. As an example, the hook member  252  may be attached to the scaffold plank  250  via a connection member which cramps and is fixed to a front surface  256  and a back surface  257  of the scaffold plank  250  formed of foamed synthetic resin. In this case, the polyurea resin layer may cover the connection member from the above. 
     According to such a configuration, it is possible to provide the scaffold plank  250  with increased rigidity while achieving weight reduction. 
       FIG. 39  is a view showing an example of a panel  260  as a building material in an eighteenth embodiment of the present invention. The panel  260  may be a building material for a house. The panel  260  may be an exterior wall material of a house, a floor material of a house, or an interior material of a house. The panel  260  is an example of the structure  100 . 
     The external shape of the panel  260  of the present example may be a plate shape. However, the external shape of the panel  260  is not limited thereto. The panel  260  includes the main body portion  101  having a hollow configuration. The main body portion  101  may include an outer shell portion  102  formed of a material selected from the group consisting of metal, ceramic, wood, and resin. In particular, the outer shell portion  102  may be a polyurea resin layer. In the present example, the outer shell portion  102  is formed as a hollow configuration having a rectangular cross-section. The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102 . At the internal space, gaps other than the reinforcement members  20  may be filled with the foamed synthetic resin  26 . However, the foamed synthetic resin  26  may not be filled thereto. 
     The panel  260  of the present example may include a fastening portion  261 . The fastening portion  261  may connect the panel  260  to another member or another panel  260 . The fastening portion  261  may be formed of metal, reinforced plastic, wood, or the like. The fastening portion  261  may be an insertion portion providing connection by being inserted into an insertion hole formed in another member or another panel  260 . In this case, the insertion portion may be provided with a stopper mechanism for locking the insertion portion in the insertion hole so as not to come out of the inserted insertion hole. Alternatively, the fastening portion  261  may be a male screw. Not limited specifically to the above, any of various fastening mechanisms can be employed as the fastening mechanism of the fastening portion  261 . 
     One end  262  of the fastening portion  261  is embedded in the main body portion  101 . Another end  264  of the fastening portion  261  is exposed from the main body portion  101 . The one end  262  of the fastening portion  261  may have a bent portion  266 . The bent portion  266  is a portion extending in a direction intersecting with a direction extending from one end  262  to the other end  264  of the fastening portion  261 . The bent portion  266  can function as an anchor portion which prevents the fastening portion  261  from coming out of the main body portion  101 . Here, not limited to have the fastening portion  261 , the panel  260  may not have the fastening portion  261 . 
     The manufacturing method of the panel  260  of the present embodiment may be similar to the manufacturing method of the structure in  FIG. 30 . The manufacturing method may include the step of forming the main body portion  101  by molding a material of the main body portion  101  such that the plurality of reinforcement members  20  and the one end  262  of the fastening portion  261  are embedded therein. The manufacturing method may include a main body portion application step of applying polyurea resin on the outer surface of the molded foamed synthetic resin  26  for the main body portion  101  after the foamed synthetic resin  26  is molded. Thus, the outer shell portion  102  can be formed of the polyurea resin. According to the panel  260  as a building material of the present embodiment, it is possible to increase the rigidity while achieving weight reduction. 
       FIG. 40  is a view illustrating an example of an impact absorbing member  270  in a nineteenth embodiment of the present invention. The impact absorbing member  270  may be cut into an appropriate size according to an object and attached to the surface of the object whose impact resistance is to be increased. For example, the impact absorbing member  270  is affixed on the surface of a moving device. Examples of the moving device include various devices such as vehicles, in-hospital moving support systems, electric carts for the elderly, and golf carts. 
     Further, the impact absorbing member  270  may be affixed on the inner surface or the outer surface of a box body such as a container. The impact absorbing member  270  may be affixed to the bottom surface or the front surface of footwear such as slippers. The impact absorbing member  270  may be affixed to the surface of a wearing article such as a helmet. However, the object to which the impact absorbing member  270  is affixed is not limited to these moving devices, box bodies, footwear, and wearing articles. 
     The impact absorbing member  270  may include an adhesive tape portion  271  and the structure  100 . The adhesive tape portion  271  includes a tape body  272 , a first adhesive layer  273 , and a second adhesive layer  274 . The first adhesive layer  273  is an adhesive layer applied on one surface of the tape body  272 , and serves as an adhesive surface for affixing the impact absorbing member  270  to an object. The second adhesive layer  274  fixes the adhesive tape portion  271  and the structure  100  to each other. The tape body  272  may be formed of a flexible material. A plurality of the structures  100  may be arranged on one adhesive tape portion  271 , or one structure  100  may be arranged thereon. Not limited to the arrangement shown in  FIG. 40 , a plurality of the structures  100  may be arranged on the adhesive tape portion  271  two-dimensionally along the XY plane. Thus, a user can cut out and use the impact absorbing member  270  in a necessary range. 
     The configuration of the structure  100  may be similar to that of any of the structures  100  in the ninth to twelfth embodiments shown in  FIGS. 27 to 31 . Therefore, description thereof will not be repeated. Receiving input of use application of the impact absorbing member  270 , the elasticity of the coating layer  24  may be changed in accordance with the use application. In one example, each use application and the content ratio between “diethyltoluenediamine” which is a constituent solution of an amine solution and “diphenylmethane diisocyanate” which is a constituent solution of an isocyanate solution may be stored as table data, and a computer may determine the content ratio with reference to the table data. 
       FIG. 41  is a view showing another example of the impact absorbing member  270 . In the present example, a base member  275  is added to the impact absorbing member  270  shown in  FIG. 40 . The base member  275  is laminated on the adhesive tape portion  271 . In the present example, the base member  275  is laminated on the upper surface of the adhesive tape portion  271 . Specifically, the base member  275  is fixed to the adhesive tape portion  271  by the second adhesive layer  274  of the adhesive tape portion  271 . The base member  275  may include one or more types of materials selected from the group consisting of foamed synthetic resin, carbon fibers, polyamide-based synthetic fibers, silicate fibers, basalt fibers, an inorganic material powder highly-blended thin film sheet, and cellulose nanofibers. 
     When the base member  275  is foamed synthetic resin, synthetic resin which forms the base member  275  may be a polymer compound. As a more specific example, synthetic resin forming the base member  275  is formed of one or more materials selected from polystyrene, polyethylene, polypropylene, and polyurethane. Foamed synthetic resin refers to synthetic resin described above in which fine bubbles are dispersed. In one example, the base member  275  is formed of foamed styrene (foamed polystyrene). One or more of the structures  100  described above are arranged on the base member  275 . The base member  275  and the structure  100  may be bonded by a third adhesive layer  276 . 
     As shown in the present example, the structure of the present invention may also be used as a part of a composite material laminated on another base member  275 . 
     Although the impact absorbing member  270  has been described with reference to  FIGS. 40 and 41 , the structures shown in  FIGS. 40 and 41  may be a corrosion inhibitor or a thermal insulator. 
       FIG. 42  is a sectional view showing an example of a pipe body  280  in a twentieth embodiment of the present invention. The pipe body  280  of the present example is inserted as a new pipe into an aged existing pipe  282 . The existing pipe  282  may be an existing water pipe or another pipe. The existing pipe  282  functions as a sheath pipe. The pipe body  280  is an example of the structure  100 . 
     The outer shape of the pipe body  280  may be a cylindrical shape. The pipe body  280  has the main body portion  101 . The main body portion  101  may include an outer shell portion  102  formed of a material selected from the group consisting of metal, ceramic, and resin. In particular, the outer shell portion  102  may be a polyurea resin layer. The outer shell portion  102  is a hollow member surrounding a hollow space. Thus, the portion of the pipe body  280  having an annular cross-section is formed as a hollow configuration rather than a solid configuration. The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102 . At the internal space, gaps other than the reinforcement members  20  may be filled with the foamed synthetic resin  26 . However, the foamed synthetic resin  26  may not be filled thereto. 
     The manufacturing method of the pipe body  280  of the present embodiment may be similar to the manufacturing method of the structure in  FIG. 30 . The manufacturing method may include the step of forming the main body portion  101  by molding the foamed synthetic resin  26  for the main body portion  101 , which is the material of the main body portion  101 , into a pipe shape such that the plurality of reinforcement members  20  are embedded therein. The manufacturing method may include a main body portion application step of applying polyurea resin on the outer surface of the molded foamed synthetic resin  26  for the main body portion  101  after the foamed synthetic resin  26  is molded into a pipe shape. Thus, the outer shell portion  102  can be formed of polyurea resin. According to the pipe body  280  of the present embodiment, it is possible to increase the rigidity while achieving weight reduction. 
       FIG. 43  is a sectional view showing an example of a packaging container  300  in a twenty-first embodiment of the present invention. A packaging container  300  packs an object to be packaged  302 . In particular, the packaging container  300  may be airborne and dropped from the sky to be delivered to a destination. The object to be packaged  302  is not particularly limited, but is suitable for air transportation of pharmaceuticals and the like such as various vaccines. 
     The packaging container  300  includes a first container half body  310 , a second container half body  320 , and at least one pair of films  340 . The open ends of the first container half body  310  and the second container half body  320  are closed as being abut against each other to form a container ( 310 ,  320 ). In the present example, the first container half body  310  and the second container half body  320  are combined to form an accommodation space  330 . Note that the first container half body  310  and the second container half body  320  may not necessarily have the same size. 
     The container ( 310 ,  320 ) of the present example has a spheroidal shape (prolate spheroid shape) in which the major axis is the axis of rotation as a whole. That is, the container ( 310 ,  320 ) has a rugby ball shape. In the present example, the container ( 310 ,  320 ) may be divided into the first container half body  310  and the second container half body  320  in the plane of separation along the major axis. 
     In the container ( 310 ,  320 ) of the present example, the first container half body  310  and the second container half body  320  are examples of the structure  100 , respectively. The first container half body  310  has a main body portion  101   a . The main body portion  101   a  may include an outer shell portion  102   a  formed of a material selected from the group consisting of metal, ceramic, and resin. In particular, the outer shell portion  102   a  may be a polyurea resin layer. The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102   a . The plurality of reinforcement members  20  may include reinforcement members  20  having different sizes. At the internal space, gaps other than the reinforcement members  20  may be filled with the foamed synthetic resin  26   a.    
     The second container half body  320  has the main body portion  101 . The main body portion  101  may include an outer shell portion  102   b . The plurality of reinforcement members  20  are arranged at the internal space surrounded by the outer shell portion  102   b . At the internal space, gaps other than the reinforcement members  20  may be filled with the foamed synthetic resin  26   b.    
     The pair of films  340  include a first film  340   a  and a second film  340   b . The first film  340   a  is fixed in a stretched state along the open end of the first container half body  310 . The second film  340   b  is fixed in a stretched state along the open end of the second container half body  320 . 
     The first film  340   a  and the second film  340   b  are fixed to be faced to each other in a state in which the first film  340   a  and the second film  340   b  are stretched in the accommodation space  330  formed in the container ( 310 ,  320 ). The packaging container  300  of the present embodiment holds the object to be packaged  302  between the pair of films  340 . The object to be packaged  302  may be sandwiched between a pair of films  340  in a state of being further wrapped with a cushioning material. 
     The packaging container  300  may have a coupling portion  350 . The coupling portion  350  couples the first container half body  310  and the second container half body  320 . The coupling portion  350  of the present example includes a protrusion portion  351 , a support portion  353 , and a clamp portion  355 . One end of the protrusion portion  351  may be embedded in the main body portion  101   a  of the first container half body  310 , and the other end thereof may protrude outward from the surface. The one end of the protrusion portion  351  of the present example has a bent portion  352  which is bent in the main body portion  101   a  so as not to be easily pulled out. One end of the support portion  353  is embedded in the main body portion  101   b  of the second container half body  320 , and the clamp portion  355  is rotatably connected to the other end thereof. The clamp portion  355  is fixed by being fitted with the protrusion portion  351 . The one end of the support portion  353  has a bent portion  354  which is bent in the main body portion  101   b  so as not to be easily pulled out. Here, the coupling portion  350  is not particularly limited as long as it couples the first container half body  310  and the second container half body  320 . 
     One end of the container ( 310 ,  320 ) may be provided with a parachute portion  360  which reduces the falling speed of the packaging container  300  when the packaging container  300  falls from the sky. Further, the packaging container  300  may be arranged with a GPS transmitter  358 . 
       FIG. 44  is a sectional view showing an example of a rail tie  410  for railroad in a twenty-second embodiment of the present invention. In the present example, the rail tie  410  for railroad formed of prestressed concrete (PS concrete) is shown. However, the rail tie  410  may have a plate shape having a trapezoidal cross-section. The rail tie  410  is an example of the structure  100 . 
     The rail tie  410  of the present example may not have the outer shell portion  102 . The main body portion  101  is formed by molding a material  27  of the main body portion  101  into the shape of the main body portion  101 . The material  27  of the main body portion  101  may be concrete. The plurality of reinforcement members  20  are embedded in the material  27  of the main body portion  101 . 
     The manufacturing method of the structure  100  of the present embodiment may include a preparation step and a step of forming the main body portion  101 . In the preparation step, the plurality of reinforcement members  20  are prepared. The reinforcement members  20  may be similar to those in the first to tenth embodiments. The manufacturing method includes the step of forming the main body portion  101  by molding the material  27  of the main body portion  101  such that the plurality of reinforcement members  20  are embedded therein. In this example, concrete which is the material  27  of the main body portion  101  is poured into a mold. At that time, the reinforcement members  20  are arranged in the mold so that the plurality of reinforcement members  20  are embedded in the material  27 . Specifically, a technique of insert molding may be used. 
     According to the present example, the rigidity of the rail tie  410  can be increased, the material of the concrete to be used can be saved, and weight reduction can be achieved. In the example shown in  FIG. 44 , description has been provided on the case in which the outer shell portion  102  is not provided similarly to the structure  100  shown in  FIG. 31 , but the rail tie  410  is not limited thereto. The configuration and manufacturing method similar to those of the structure  100  in the eighth to twelfth embodiments shown in  FIGS. 27 to 31  can be applied to the rail tie  410 . In other words, the main body portion  101  of the rail tie  410  may be formed of at least one material selected from the group consisting of metal, ceramic, wood, and resin. 
     Further, the rail tie  410  may include the main body portion  101  having a hollow configuration surrounding the internal space. 
     Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the embodiments described above. It will be apparent to those skilled in the art that various modifications and improvements can be made to the embodiments described above. It is also apparent from the scope of the claims that the embodiments added with such modifications or improvements are also included in the technical scope of the present invention. 
     It should be noted that the order of execution of processes, such as operations, procedures, steps, and stages in the devices, systems, programs, and methods described in the claims, specification, and figures may be implemented in any order unless otherwise specified as “before”, “prior to”, or the like, and unless otherwise an output of a previous process is used in a later process. Even if operation flow in the claims, specification, or drawings is described using “first”, “next”, and the like for convenience, it does not mean that the operation flow is necessarily performed in the order. 
     REFERENCE SIGNS LIST 
     
         
           1  Antenna support pole 
           2  Antenna 
           4  Power pole 
           6  Street lamp pole 
           10  Cylindrical portion 
           11  Cylinder 
           12  Cylinder 
           13  Cylinder 
           14  Flange portion 
           15  Rib 
           16  Lightning rod 
           17  Side surface 
           18  Main surface 
           20  Reinforcement member 
           21  Reinforcement member 
           22  Base material 
           24  Coating layer 
           25  Space 
           26  Foamed synthetic resin 
           27  Material 
           30  Fixing portion 
           32  Filling material 
           33  Connection portion 
           34  Extension portion 
           41  Region 
           42  Region 
           43  Region 
           51  External reinforcement portion 
           52  External reinforcement portion 
           54  External reinforcement portion 
           55  Cover portion 
           62  Supply unit 
           64  Nozzle 
           66  Nozzle 
           72  Opening 
           82  Opening 
           90  Carrying-in device 
           91  Storage tank 
           92  Supply pipe 
           93  Motor 
           94  Alignment supply device 
           95  Conveyance pipe 
           96  Blower 
           97  Control unit 
           100  Structure 
           101  Main body portion 
           102  Outer shell portion 
           104  Cover portion 
           210  Pallet 
           211  Pallet main body 
           212  Placement surface 
           214  Back surface 
           216  Leg 
           220  Box body 
           222  Lid portion 
           224  Storage portion 
           226  Storage space 
           230  Airframe 
           232  Beam portion 
           234  Rib 
           240  Bumper 
           241  Impact absorbing portion 
           242  Beam portion 
           243  Attachment portion 
           244  Exterior portion 
           245  Resin material 
           250  Scaffold plank 
           252  Hook member 
           256  Front surface 
           257  Back surface 
           260  Panel 
           261  Fastening portion 
           262  One end 
           264  Other end 
           266  Bent portion 
           270  Impact absorbing member 
           271  Adhesive tape portion 
           272  Tape body 
           273  First adhesive layer 
           274  Second adhesive layer 
           275  Base member 
           276  Third adhesive layer 
           280  Pipe body 
           282  Existing pipe 
           300  Packaging container 
           302  Object to be packaged 
           310  First container half body 
           320  Second container half body 
           330  Accommodation space 
           340  Film 
           350  Coupling portion 
           351  Protrusion portion 
           352  Bent portion 
           353  Support portion 
           354  Bent portion 
           355  Clamp portion 
           358  GPS transmitter 
           360  Parachute portion 
           410  Rail tie