Joints, pipe members, pipe structures, methods for connecting pipe members, and methods for manufacturing pipe structures.

Abstract

This design suppresses interference between the flange portion of the joint and the existing pipe while preventing the pipe component from becoming smaller. [Solution] The joint 40 is used in a pipe member 30 that is placed inside an existing pipe 90. The joint 40 includes a first pipe section 51, a second pipe section 52 that is thicker than the first pipe section 51, and a flange section 55 provided on the first pipe section 51. The outer width of the flange section 55 is less than or equal to the outer width of the second pipe section 52.

Description

Technical Field

[0005] ,

[0004] ,

[0001] The present invention relates to a joint, a pipe member, a pipe structure, a method for connecting pipe members, and a method for manufacturing a pipe structure.

Background Art

[0002] Existing pipes such as buried water pipes, gas pipes, and oil pipes can become obsolete. As a method for renewing an obsolete existing pipe, for example, as described in Patent Documents 1 to 3, the pipe-in-pipe method is known. In the pipe-in-pipe method, a new pipe structure is laid in the buried existing pipe without removing the buried existing pipe.

[0003] The pipe-in-pipe method is carried out as follows as an example. First, a manhole is created at the end of the existing pipe. Pipe members are sequentially carried into the manhole. Inside the manhole, the carried-in pipe members are connected to the previously carried-in pipe members. The existing pipe is exposed inside the manhole. The pipe members are inserted into the existing pipe inside the manhole. That is, a long pipe structure formed by connecting a plurality of pipe members advances through the existing pipe, and a new pipe structure is laid in the existing pipe. According to the pipe-in-pipe method, since it is not necessary to remove the existing pipe, the cost and the construction period can be reduced.

[0004] As a method for connecting pipe members, as described in Patent Document 1, electric fusion is known. In electric fusion, in many cases, an electric fusion device including a generator and a fusion machine is used. The fusion machine is installed on the fusion target of the pipe member. Therefore, the fusion machine is brought into the manhole. A voltage from the generator is applied to the fusion machine. When the size of the manhole is small or when the moisture inside the manhole cannot be sufficiently removed, it is difficult to connect the pipe members by electric fusion.

[0005] By using fittings with flanges, pipe members can be mechanically connected. Mechanical connection of pipe members does not require a large workspace, nor does it require removing water from the shaft. However, when using flanges that protrude radially outward, the pipe members as a whole become smaller in order to avoid interference between the flange and the existing pipe. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-100767 [Patent Document 2] Japanese Patent Publication No. 2016-8650 [Patent Document 3] Patent No. 6726813 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] This invention has been made in consideration of the above points, and aims to suppress interference between the flange portion of the joint and the existing pipe while suppressing the miniaturization of the pipe member. [Means for solving the problem]

[0008] This invention encompasses the following inventions. [1] A joint used in pipe members placed inside an existing pipe, The first pipe section and, A second pipe section which is thicker than the first pipe section, The device comprises a flange portion provided on the first pipe portion, A joint in which the outer width of the flange portion is less than or equal to the outer width of the second pipe portion. [2] Further comprising a tapered section located between the first pipe section and the second pipe section, The joint according to [1], wherein the outer width of the tapered portion decreases from the second pipe portion toward the first pipe portion. [3] The joint according to [2], wherein the outer surface of the tapered portion is inclined at an angle greater than 0° and less than or equal to 60° with respect to the axial direction in which the first pipe portion and the second pipe portion face each other. [4] Further comprising a tapered section located between the first pipe section and the second pipe section, The joint according to any one of [1] to [3], wherein the inner width of the tapered portion decreases from the second pipe portion toward the first pipe portion. [5] The joint according to [4], wherein the inner surface of the tapered portion is inclined at an angle greater than 0° and less than or equal to 60° with respect to the axial direction in which the first pipe portion and the second pipe portion face each other. [6] A pipe member that is placed inside an existing pipe, Joints and, The pipe is connected to the aforementioned joint, The aforementioned joint is the joint described in any one of claims 1 to 5. The pipe is connected to the second pipe section of the joint, A pipe member wherein the outer width of the pipe is greater than or equal to the outer width of the flange portion. [7] A pipe member that is placed inside an existing pipe, A first joint which is a joint described in any one of items [1] to [5], A second joint which is a joint described in any one of items [1] to [5], A pipe located between the first joint and the second joint, The second pipe section of the first joint and the first end of the pipe are connected, The second pipe section of the second joint and the second end of the pipe are connected. A pipe member wherein the outer width of the pipe is greater than or equal to the outer width of the flange portion of the first joint, and greater than or equal to the outer width of the flange portion of the second joint. [8] Further comprising a plate located on the first pipe section, The plate is located between the flange portion and the second pipe portion, The aforementioned plate is made of metal and is provided with bolt holes through which bolts pass. The pipe member according to [6] or [7], wherein the flange portion is made of resin and is provided with a bolt through hole through which the bolt passes. [9] The plate includes a first plate portion and a second plate portion, The plate is an annular shape that surrounds the first pipe section by a combination of the first plate section and the second plate section. The inner width of the plate is greater than or equal to the outer width of the first pipe section. The pipe member according to [8], wherein the outer width of the plate is less than or equal to the outer width of the second pipe section.

[10] Further comprising an annular plate including a through hole through which the first pipe section passes, The inner width of the plate is greater than or equal to the outer width of the first pipe section. The outer width of the plate is less than or equal to the outer width of the second pipe section. The aforementioned plate is made of metal, The pipe member according to [6] or [7], wherein the flange portion is made of resin.

[11] A pipe structure to be placed inside an existing pipe, The system comprises multiple pipe members as described in any one of items [6] to

[10] , The aforementioned plurality of pipe members are arranged in order in one direction, A pipe structure in which two pipe members adjacent to each other in one direction are connected by fixing the flange portion of the second joint of one pipe member to the flange portion of the first joint of the other pipe member with a fastener. A method for connecting two pipe members as described in any one of the items

[12] [6] to

[10] , The steps include arranging the two pipe members such that the flange portion of the second joint of one pipe member faces the flange portion of the first joint of the other pipe member, A method for connecting pipe members, comprising the step of connecting two pipe members by fixing the flange portion of the second joint of one pipe member and the flange portion of the first joint of the other pipe member with a fastener.

[13] In the step of connecting the two pipe members, the two pipe members are connected using bolts that sequentially pass through a plate positioned on the second joint of the one pipe member, the flange portion of the second joint of the one pipe member, the flange portion of the first joint of the other pipe member, and a plate positioned on the first joint of the other pipe member, according to the method for connecting pipe members described in

[12] .

[14] A method for manufacturing a pipe structure including a plurality of pipe members connected to each other inside an existing pipe,

[11] or by the method for connecting pipe members described in

[12] , a connecting step of connecting the two pipe members, and a moving step of feeding the two connected pipe members into the existing pipe, and repeating the connecting step and the moving step, a method for manufacturing a pipe structure.

Advantages of the Invention

[0009] According to the present invention, it is possible to suppress miniaturization of the pipe member while suppressing interference between the flange portion of the joint and the existing pipe.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a diagram for explaining an embodiment, and shows an example of a pipe structure. [Figure 2] FIG. 2 is a partial cross-sectional view showing a cross-section along the longitudinal direction of the pipe structure shown in FIG. 1. [Figure 3] FIG. 3 is a diagram showing an example of a pipe member included in the pipe structure shown in FIG. 1. [Figure 4] FIG. 4 is a plan view showing the pipe member shown in FIG. 3 from a direction orthogonal to its axial direction. [Figure 5] FIG. 5 is a plan view showing the pipe member shown in FIG. 3 from a direction parallel to its axial direction. [Figure 6] FIG. 6 is a cross-sectional view showing a cross-section along line A-A of FIG. 5. [Figure 7]Figure 7 is a plan view showing an example of a plate included in the pipe structure shown in Figure 1, viewed from the longitudinal direction of the pipe structure. [Figure 8A] Figure 8A shows an example of a method for manufacturing a pipe structure. [Figure 8B] Figure 8B shows an example of a method for manufacturing a pipe structure. [Figure 8C] Figure 8C shows an example of a method for manufacturing a pipe structure. [Figure 8D] Figure 8D shows an example of a method for manufacturing a pipe structure. [Figure 8E] Figure 8E shows an example of a method for manufacturing a pipe structure. [Figure 8F] Figure 8F shows an example of a method for manufacturing a pipe structure. [Figure 8G] Figure 8G shows an example of a method for manufacturing a pipe structure. [Figure 9] Figure 9 is a partial cross-sectional view corresponding to Figure 2, and shows a modified example of a pipe structure. [Figure 10] Figure 10 is a cross-sectional view showing an example of a cover included in the pipe structure shown in Figure 9, in a section perpendicular to the longitudinal direction of the pipe structure. [Figure 11] Figure 11 is a cross-sectional view, similar to Figure 10, showing another example of a cover included in the pipe structure shown in Figure 9. [Figure 12] Figure 12 is a cross-sectional view showing a modified example of a joint included in a pipe member, similar to Figure 6. [Modes for carrying out the invention]

[0011] An embodiment of the present invention will be described below with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios may be changed from those of the actual object as appropriate for ease of understanding. Some components shown in some drawings may be omitted in other drawings. In cross-sectional views, hatching may be omitted for ease of understanding. Some components shown in some drawings may be omitted in other drawings.

[0012] In this specification, terms such as "parallel," "orthogonal," and "identical," as well as values ​​of length and angle, which specify shapes, geometric conditions, and their degrees, shall not be limited to their strict meanings, but shall be interpreted to include a range that can be expected to function similarly.

[0013] To clarify directional relationships between drawings, some drawings use arrows with common reference numerals to indicate the common longitudinal direction DA, axial direction D1, circumferential direction D2, and radial direction D3. The tip of the arrow represents the first side in each direction. The opposite side of the arrow represents the second side in each direction.

[0014] Figures 1 to 12 are diagrams illustrating one embodiment. Figures 1 and 2 show a pipe structure 10. The pipe structure 10 is placed inside an existing pipe 90. The pipe structure 10 is elongated. The pipe structure 10 has a longitudinal direction DA. The pipe structure 10 has openings at both ends in the longitudinal direction DA. The pipe structure 10 is cylindrical.

[0015] As shown in Figures 1 and 2, the pipe structure 10 includes a plurality of pipe members 30. Each pipe member 30 has an axial direction D1. Each pipe member 30 has openings at both ends in the axial direction D1. The openings at both ends face the axial direction D1. Each pipe member 30 is cylindrical. As shown in Figure 1, in the pipe structure 10, the plurality of pipe members 30 are arranged in a straight line in the longitudinal direction DA. The longitudinal direction DA of the pipe members 30 is parallel to the axial direction D1 of the pipe structure 10.

[0016] As shown in Figure 2, the second opening of the pipe member 30 located on the first side (right side in Figure 2) in the longitudinal direction DA faces the first opening of the pipe member 30 located on the second side (left side in Figure 2) in the longitudinal direction DA. The second end of the pipe member 30 located on the first side (right side in Figure 2) in the longitudinal direction DA is connected to the first opening of the pipe member 30 located on the second side (left side in Figure 2) in the longitudinal direction DA. As a result, the interiors of the two adjacent pipe members 30 in the longitudinal direction DA of the pipe structure 10 are connected to each other.

[0017] The pipe structure 10 can be laid inside the existing pipe 90 using the pipe-in-pipe method. As will be described later, in the pipe-in-pipe method, pipe members 30 are sequentially brought into the vertical shaft 91. The pipe members 30 brought into the vertical shaft 91 are connected to another pipe member 30 that was brought into the vertical shaft 91 immediately before, within the first vertical shaft 91. At this time, the other pipe member 30 may be partially inserted into the existing pipe 90 that has opened into the vertical shaft 91. The pipe member 30 connected to the other pipe member 30 is also sent into the existing pipe 90 and then connected to the next pipe member 30 that is brought into the vertical shaft 91 next. In the pipe-in-pipe method, a long pipe structure 10, which is made up of multiple pipe members 30 connected together, moves inside the existing pipe 90 and is laid inside the existing pipe 90 as a new pipe structure 10. The pipe-in-pipe construction method eliminates the need to remove the existing pipe 90, thus reducing costs and construction time.

[0018] The use of the pipe structure 10 is not particularly limited. The pipe structure 10 may be a transport pipe for fluids or powders. The fluid may be a liquid or a gas. The liquid may be water. The gas may be air, an inert gas, or natural gas. Pressure may be applied inside the pipe structure 10.

[0019] In the example shown in Figure 2, fasteners 20 are used to connect adjacent pipe members 30 in the longitudinal direction DA. That is, the illustrated pipe structure 10 includes a plurality of pipe members 30 and fasteners 20 for connecting adjacent pipe members 30 to each other.

[0020] Figures 3 to 5 are perspective or plan views showing an example of a pipe member 30. Figure 6 is a cross-sectional view of the pipe member 30 along line AA in Figure 3. As shown in Figures 3 to 6, the pipe member 30 may include a pipe 35 and a fitting 40. The fitting 40 is connected to the pipe 35. The fitting 40 and the pipe 35 may be fixed together, and the pipe member 30 may be handled as a single unit.

[0021] A joint 40 is fixed to a joint 40 of a different pipe member 30 from the pipe member 30 containing the joint 40. That is, a joint 40 is used to connect to an adjacent joint 40. As shown in Figures 3 to 6, a pipe member 30 may contain two joints 40. The two joints 40 are connected to the pipe 35 from both ends in the axial direction D1. A pipe member 30 containing two joints 40 can be connected to other pipe members 30 on both sides in the axial direction D1 (longitudinal direction DA), as shown in Figure 1.

[0022] The pipe member 30 shown in Figures 3 to 6 includes a first joint 40A, the pipe member 30, and a second joint 40B in this order along the axial direction D1. The pipe member 30 is located between the first joint 40A and the second joint 40B. The first joint 40A and the second joint 40B may have the same configuration. The first joint 40A and the second joint 40B may have the same shape. The first joint 40A and the second joint 40B may be arranged symmetrically. The first joint 40A and the second joint 40B may have the same shape and be arranged symmetrically with respect to a plane perpendicular to the axial direction D1.

[0023] In this specification, any description using the term "joint 40" may refer to both the first joint 40A and the second joint 40B.

[0024] Unlike the illustrated example, the pipe member 30 may include only one joint 40. The joint 40 may be connected to the pipe 35 from either side in the axial direction D1. In other words, the joint 40 may be connected to either the first end 35a or the second end 35b of the pipe member 30. For example, in Figure 1, the pipe members 30 located at both ends in the longitudinal direction DA may include only one joint 40.

[0025] The pipe 35 is a cylindrical member. The pipe 35 has openings at both ends in the axial direction D1 of the pipe member 30 that includes the pipe 35. The pipe 35 includes a first end 35a and a second end 35b. The first end 35a and the second end 35b face each other in the axial direction D1. The first end 35a and the second end 35b are located at both ends of the pipe 35 in the axial direction D1. The pipe 35 opens at the first end 35a. The pipe 35 opens at the second end 35b.

[0026] The pipe 35 may be cylindrical, elliptical, or rectangular. The pipe 35 may be elongated in the axial direction D1 of the pipe member 30 containing the pipe 35. As shown in Figure 6, the inner width 35y or inner diameter 35y of the pipe 35 may be constant at each position in the axial direction D1. The outer width 35x or outer diameter 35x of the pipe 35 may be constant at each position in the axial direction D1.

[0027] The joint 40 is cylindrical. The joint 40 has openings at both ends in the axial direction D1 of the pipe member 30 that includes the joint 40. The joint 40 is aligned with the pipe 35 in the axial direction D1 of the pipe member 30. One opening of the joint 40 faces one opening of the pipe 35. One opening of the joint 40 is connected to one opening of the pipe 35. As a result, the interiors of adjacent pipes 35 and joints 40 in the axial direction D1 of the pipe member 30 are interconnected.

[0028] In the examples shown in Figures 3 to 6, the first joint 40A is connected to the first end 35a located on the first side in the axial direction D1 of the pipe member 30. The second joint 40B is connected to the second end 35b located on the second side in the axial direction D1 of the pipe member 30.

[0029] As shown in Figure 6, the joint 40 includes a first pipe section 51, a second pipe section 52, and a flange section 55. The first pipe section 51 is narrower than the second pipe section 52. The flange section 55 is located on the first pipe section 51. The outer width 55x of the flange section 55 is less than or equal to the outer width 52x of the second pipe section 52. The first pipe section 51 and the second pipe section 52 face each other in the axial direction D1.

[0030] The first pipe section 51 is cylindrical. The first pipe section 51 has openings at both ends in the axial direction D1 of the pipe member 30 including the first pipe section 51. The first pipe section 51 may be cylindrical, elliptical, or rectangular. As shown in Figure 6, the inner width 51y or inner diameter 51y of the first pipe section 51 may be constant at each position in the axial direction D1. The outer width 51x or outer diameter 51x of the first pipe section 51 may be constant at each position in the axial direction D1.

[0031] In the illustrated example, the first pipe section 51 is cylindrical. The first pipe section 51 constitutes the end of the joint 40 in the axial direction D1. The first pipe section 51 constitutes the end of the joint 40 that is away from the pipe 35 in the axial direction D1. The first pipe section 51 constitutes the end of the pipe member 30 in the axial direction D1. The first pipe section 51 constitutes the end of the pipe member 30 that is away from the pipe 35 in the axial direction D1. The first pipe section 51 constitutes the end of the pipe member 30 that is closest to another pipe member 30 adjacent in the axial direction D1.

[0032] The second pipe section 52 is cylindrical. The second pipe section 52 has openings at both ends in the axial direction D1 of the pipe member 30 including the second pipe section 52. The second pipe section 52 may be cylindrical, elliptical, or rectangular. As shown in Figure 6, the inner width 52y or inner diameter 52y of the second pipe section 52 may be constant at each position in the axial direction D1. The outer width 52x or outer diameter 52x of the second pipe section 52 may be constant at each position in the axial direction D1.

[0033] In the illustrated example, the second pipe section 52 is cylindrical. The second pipe section 52 constitutes the end of the joint 40 in the axial direction D1. The second pipe section 52 constitutes the end of the joint 40 in the axial direction D1 that is close to the pipe 35. The second pipe section 52 connects to one end of the pipe 35. The second pipe section 52 is in contact with one end of the pipe 35.

[0034] As shown in Figure 6, the flange portion 55 may be located on a portion of the first pipe portion 51 in the axial direction D1. As shown in Figure 3, the flange portion 55 may be located on the first pipe portion 51 and extend in the circumferential direction. As shown in Figure 3, the flange portion 55 may be annular. Unlike the illustrated example, multiple flange portions 55 may be provided at intervals in the circumferential direction. The width of the flange portion 55 along the axial direction D1 may be constant at each position in the circumferential direction. The height of the flange portion 55 protruding radially from the first pipe portion 51 may be constant at each position in the circumferential direction.

[0035] As shown in Figure 3, the circumferential direction D2 is the direction along the circumference of the pipe member 30 centered on the central axis 30C. As shown in Figure 4, the radial direction D3 is the direction perpendicular to the central axis 30C of the pipe member 30. The outer side in the radial direction D3 is the side away from the central axis 30C of the pipe member 30. The inner side in the radial direction D3 is the side close to the central axis 30C of the pipe member 30.

[0036] In the illustrated example, the flange portion 55 is annular. It is located on a portion of the first pipe portion 51 that is away from the pipe 35 in the axial direction D1. The flange portion 55 together with the first pipe portion 51 forms the end of the joint 40 in the axial direction D1. The flange portion 55 together with the first pipe portion 51 forms the end of the joint 40 that is away from the pipe 35 in the axial direction D1. The flange portion 55 together with the first pipe portion 51 forms the end of the pipe member 30 in the axial direction D1. The flange portion 55 together with the first pipe portion 51 forms the end of the pipe member 30 that is away from the pipe 35 in the axial direction D1. The flange portion 55 forms the end of the pipe member 30 that is closest to another pipe member 30 adjacent to it in the axial direction D1.

[0037] As shown in Figure 2, the flange portion 55 is fixed to the flange portion 55 of another pipe member 30 using a fastener 20. By fixing the flange portions 55 of two adjacent pipe members 30, the two adjacent pipe members 30 are connected.

[0038] The fastener 20 is not particularly limited. In the example shown in Figure 2, the fastener 20 includes a bolt 21 and a nut 22. As shown in Figures 3 and 5, the flange portion 55 may be provided with bolt through holes 56 through which the bolt 21 passes. The flange portion 55 may be provided with a plurality of bolt through holes 56 spaced apart in the circumferential direction. The bolt through holes 56 penetrate the flange portion 55 in the axial direction D1.

[0039] The outer width 52x of the second pipe section 52 may be greater than the outer width 51x of the first pipe section 51. The inner width 52y of the second pipe section 52 may be greater than the inner width 51y of the first pipe section 51. The outer width 51x of the first pipe section 51 may be less than the outer width 52x of the second pipe section 52. The inner width 51y of the first pipe section 51 may be less than the inner width 52y of the second pipe section 52.

[0040] The outer width and inner width are radial lengths (dimensions). When comparing the outer widths of two parts, compare the maximum outer dimensions in the same direction when observed from the axial direction D1. When comparing the inner widths of two parts, compare the maximum inner dimensions in the same direction when observed from the axial direction D1.

[0041] As shown in the illustrated example, when both the first pipe section 51 and the second pipe section 52 are cylindrical, the outer width is the outer diameter and the inner width is the inner diameter. The outer diameter 52x of the second pipe section 52 may be larger than the outer diameter 51x of the first pipe section 51. The inner diameter 52y of the second pipe section 52 may be larger than the inner diameter 51y of the first pipe section 51. The outer diameter 51x of the first pipe section 51 may be smaller than the outer diameter 52x of the second pipe section 52. The inner diameter 51y of the first pipe section 51 may be smaller than the inner diameter 52y of the second pipe section 52.

[0042] The outer width 52x of the second pipe section 52 may be greater than or equal to the outer width 55x of the flange section 55. The outer width 52x of the second pipe section 52 may be greater than the outer width 55x of the flange section 55. The outer width 55x of the flange section 55 may be less than or equal to the outer width 52x of the second pipe section 52. The outer width 55x of the flange section 55 may be less than the outer width 52x of the second pipe section 52.

[0043] As shown in the illustrated example, when both the first pipe section 51 and the second pipe section 52 are cylindrical, the outer width is the outer diameter and the inner width is the inner diameter. The outer diameter 52x of the second pipe section 52 may be greater than or equal to the outer diameter 55x of the flange section 55. The outer diameter 52x of the second pipe section 52 may be greater than the outer diameter 55x of the flange section 55. The outer diameter 55x of the flange section 55 may be less than or equal to the outer diameter 52x of the second pipe section 52. The outer diameter 55x of the flange section 55 may be less than the outer diameter 52x of the second pipe section 52.

[0044] The second pipe section 52 is connected to the pipe 35. The outer width 52x of the second pipe section 52 may be the same as or different from the outer width 35x of the pipe 35, as shown in the figure. The outer diameter 52x of the second pipe section 52 may be the same as or different from the outer diameter 35x of the pipe 35, as shown in the figure. The inner width 52y of the second pipe section 52 may be the same as or different from the inner width 35y of the pipe 35, as shown in the figure. The inner diameter 52y of the second pipe section 52 may be the same as or different from the inner diameter 35y of the pipe 35, as shown in the figure.

[0045] As shown in Figures 3, 4, and 6, the joint 40 may include a tapered section 53 located between the first pipe section 51 and the second pipe section 52. The tapered section 53 may connect the first pipe section 51 and the second pipe section 52. The tapered section 53 may also be connected by contact with each of the first pipe section 51 and the second pipe section 52.

[0046] The tapered portion 53 is cylindrical. The tapered portion 53 has openings at both ends in the axial direction D1 of the pipe member 30 including the tapered portion 53. The outer contour of the tapered portion 53 in a cross section perpendicular to the axial direction D1 may be circular, elliptical, or angular. The inner contour of the tapered portion 53 in a cross section perpendicular to the axial direction D1 may be circular, elliptical, or angular.

[0047] In the illustrated example, the outer contour of the tapered portion 53 in a cross-section perpendicular to the axial direction D1 is circular. The tapered portion 53 is connected to the first pipe portion 51. The tapered portion 53 is in contact with the first pipe portion 51. The tapered portion 53 is connected to the second pipe portion 52. The tapered portion 53 is in contact with the second pipe portion 52.

[0048] The outer width 53x of the tapered section 53 may decrease from the second pipe section 52 to the first pipe section 51 in the axial direction D1. The outer diameter 53x of the tapered section 53 may decrease in diameter from the second pipe section 52 to the first pipe section 51 in the axial direction D1. The inner width 53y of the tapered section 53 may decrease from the second pipe section 52 to the first pipe section 51 in the axial direction D1. The inner diameter 53y of the tapered section 53 may decrease in diameter from the second pipe section 52 to the first pipe section 51 in the axial direction D1.

[0049] As shown in Figure 6, the outer width of the tapered portion 53 at the end adjacent to the first pipe portion 51 in the axial direction D1 may be the same as or different from the outer width 51x of the first pipe portion 51, as shown. The outer diameter of the tapered portion 53 at the end adjacent to the first pipe portion 51 in the axial direction D1 may be the same as or different from the outer diameter 51x of the first pipe portion 51, as shown. The outer width of the tapered portion 53 at the end adjacent to the second pipe portion 52 in the axial direction D1 may be the same as or different from the outer width 52x of the second pipe portion 52, as shown. The outer diameter of the tapered portion 53 at the end adjacent to the second pipe portion 52 in the axial direction D1 may be the same as or different from the outer diameter 52x of the second pipe portion 52, as shown.

[0050] As shown in Figure 6, the inner width of the tapered portion 53 at the end adjacent to the first pipe portion 51 in the axial direction D1 may be the same as or different from the inner width 51y of the first pipe portion 51, as shown. The inner diameter of the tapered portion 53 at the end adjacent to the first pipe portion 51 in the axial direction D1 may be the same as or different from the inner diameter 51y of the first pipe portion 51, as shown. The inner width of the tapered portion 53 at the end adjacent to the second pipe portion 52 in the axial direction D1 may be the same as or different from the inner width 52y of the second pipe portion 52, as shown. The inner diameter of the tapered portion 53 at the end adjacent to the second pipe portion 52 in the axial direction D1 may be the same as or different from the inner diameter 52y of the second pipe portion 52, as shown.

[0051] As shown in Figure 6, the tapered portion 53 has an outer surface 53a and an inner surface 53b. The outer surface 53a and the inner surface 53b are inclined with respect to the axial direction D1. In the cross section (cross section in Figure 6) passing through the central axis 30C of the pipe member 30 (joint 50), the inclination angle θa between the outer surface 53a and the axial direction D1 is greater than 0°. The inclination angle θa may be 60° or less, 45° or less, or 30° or less. In the cross section (cross section in Figure 6) passing through the central axis of the pipe member 30 (joint 40), the inclination angle θb between the inner surface 53b and the axial direction D1 is greater than 0°. The inclination angle θb may be 60° or less, 45° or less, or 30° or less.

[0052] The material constituting the joint 40 is not particularly limited. The material constituting the joint 40 can be determined according to the application of the pipe member 30 and the pipe structure 10. The material constituting the joint 40 may be metal or resin. The metal constituting the joint 40 may be steel, copper, aluminum, or an alloy thereof. The resin constituting the joint 40 may be one or more of the following: polyolefin such as polyester or polypropylene, vinyl chloride such as rigid polyvinyl chloride, polyester such as polyethylene terephthalate, polycarbonate, and acrylonitrile-butadiene-styrene copolymer resin.

[0053] The joint 40 may be manufactured by injection molding of resin. The joint 40 may also be manufactured by cutting a block of resin. The entire joint 40, including the first pipe section 51, the second pipe section 52, and the flange section 55, may be integrally molded by injection molding or by machining.

[0054] One or more of the first pipe section 51, second pipe section 52, tapered section 53, and flange section 55 that constitute the joint 40 may be formed separately from the other parts and fixed to the other parts by fusion or the like. The fusion may be electrofusion as disclosed in Patent Document 1 (JP2023-140339A). The fusion may also be butt fusion. In butt fusion, the end faces of the two parts to be joined are heated and melted, and the end faces are pressed together to fuse them.

[0055] The material constituting the pipe 35 is not particularly limited. The material constituting the pipe 35 may be determined according to the application of the pipe member 30 and the pipe structure 10. The material constituting the pipe 35 may be selected from the materials constituting the joint 40. In the pipe member 30, the material constituting the pipe 35 and the material constituting the joint 40 may be the same or different.

[0056] The pipe 35 may be integrally formed with the pipe member 30 by injection molding, machining, or the like. The pipe 35 may be formed separately from the joint 40 using the same or different material as the joint 40 and fixed to the joint 40 by fusion or the like. The fusion may be electrofusion as disclosed in Patent Document 1 (JP2023-140339A). The fusion may also be butt fusion.

[0057] As shown in Figure 2, the pipe member 30 may further include a plate 60. The plate 60 is located on the first pipe portion 51 of the joint 40 in the radial direction of the pipe member 30. The plate 60 is located between the flange portion 55 and the second pipe portion 52 in the axial direction D1 of the pipe member 30.

[0058] As shown in Figure 2, the two flange portions 55 of adjacent pipe members 30 are fixed to each other using a fastener 20. The two flange portions 55 of adjacent pipe members 30 are sandwiched between two plates 60 included in the adjacent pipe members 30. The fastener 20 fixes the two flange portions 55 located between the pair of plates 60 by pushing the pair of plates 60 toward each other.

[0059] The material constituting the plate 60 may be metal. Examples of metals include iron, steel, and stainless steel. The hardness of the material constituting the plate 60 may be higher than the hardness of the material constituting the flange portion 55. For example, the material constituting the plate 60 may be metal, and the material constituting the flange portion 55 may be resin. By setting the material constituting the plate 60 in this way, the two flange portions 55 can be fixed more stably.

[0060] The fastener 20 is not particularly limited. In the example shown in Figure 2, the fastener 20 includes a bolt 21 and a nut 22. The plate 60 is provided with a bolt through hole 63 through which the bolt 21 passes. The plate 60 may be provided with a plurality of bolt through holes 63 spaced apart in the circumferential direction. The bolt through holes 63 penetrate the plate 60 in the axial direction D1.

[0061] Figure 7 is a plan view showing the plate 60 from the axial direction D1. The plate 60 may be annular in shape. The plate 60 may be provided with a through hole 65 through which the first pipe portion 51 of the joint 40 passes.

[0062] As shown by the dashed line in Figure 7, the plate 60 may include a first plate portion 61 and a second plate portion 62. The plate 60 may be divisible into the first plate portion 61 and the second plate portion 62. The plate 60 may be an annular shape surrounding the first pipe portion 51 by the combination of the first plate portion 61 and the second plate portion 62. The combination of the first plate portion 61 and the second plate portion 62 may form a through hole 65.

[0063] The inner width 60y of plate 60 is greater than or equal to the outer width 51x of the first pipe section 51 of fitting 40. The inner width 60y of plate 60 may be greater than the outer width 51x of the first pipe section 51 of fitting 40. The outer width 60x of plate 60 may be less than or equal to the outer width 52x of the second pipe section 52 of fitting 40. The outer width 60x of plate 60 may be less than the outer width 52x of the second pipe section 52 of fitting 40.

[0064] In the illustrated example, the plate 60 is annular. In the illustrated example, the first pipe section 51 is cylindrical, and the second pipe section 52 is cylindrical. The inner diameter 60y of the plate 60 is greater than or equal to the outer diameter 51x of the first pipe section 51 of the joint 40. The inner diameter 60y of the plate 60 may be greater than the outer diameter 51x of the first pipe section 51 of the joint 40. The outer diameter 60x of the plate 60 may be less than or equal to the outer diameter 52x of the second pipe section 52 of the joint 40. The outer diameter 60x of the plate 60 may be less than the outer diameter 52x of the second pipe section 52 of the joint 40.

[0065] The example of dividing the plate 60 into two parts shown in Figure 7 is not limited to this case; the plate 60 may be divided into three or more parts.

[0066] The plate 60 may be annular as a single component. For example, by connecting a tapered section 53, which is manufactured separately from the first pipe section 51, to the first pipe section 51 that passes through the through hole 65 of the plate 60, a combination of the joint 40 and the integrated plate 60 can be obtained. The combination of the joint 40 and the integrated plate 60 can be obtained by using a three-dimensional printer.

[0067] Unlike the illustrated example, multiple plates 60 may be provided at intervals in the circumferential direction.

[0068] A manufacturing method for producing a pipe structure 10 using a pipe member 30 having the above configuration will be explained, mainly with reference to Figures 8A to 8G.

[0069] The manufacturing method described below is used to manufacture a pipe structure 10, which includes multiple interconnected pipe members 30, within an existing pipe 90. The manufacturing method includes a connecting step of connecting two pipe members 30 and a moving step of feeding the two interconnected pipe members 30 into the existing pipe 90. By repeatedly performing the connecting step and the moving step, a pipe structure 10 consisting of three or more interconnected pipe members 30 can be manufactured.

[0070] The explanation will primarily refer to Figures 8A to 8G. Figures 8A to 8G are diagrams illustrating a specific example of a method for manufacturing the pipe structure 10 shown in Figure 1. In the example shown in Figures 8A to 8G, an existing pipe 90 extends between the first shaft 91 and the second shaft 92. One end of the existing pipe 90 opens into the first shaft 91. The other end of the existing pipe 90 opens into the second shaft 92.

[0071] The first shaft 91 and the second shaft 92 are vertically extending holes. A loading device 95 is installed in the first shaft 91. The loading device 95 can load pipe members 30 into the first shaft 91. The loading device 95 may also be a crane device 95a. A drive device 96 is installed in the second shaft 92. The drive device 96 moves the pipe members 30 in the longitudinal direction of the existing pipe 90 within the existing pipe 90. The drive device 96 may, as an example, include a cable 96b and a winch 96a for pulling in the cable 96b.

[0072] Furthermore, the longitudinal direction of the existing pipe 90 is parallel to the axial direction D1 of the pipe member 30 that will be brought into the first vertical shaft 91. The longitudinal direction of the existing pipe 90 is also parallel to the longitudinal direction DA of the pipe structure 10 that will be manufactured.

[0073] As shown in Figure 8A, first, an initial loading process is carried out in which the pipe member 30 is loaded into the first vertical shaft 91. In the initial loading process, the pipe member 30 may be loaded into the vertical shaft 91 using a crane device 95a.

[0074] Next, as shown in Figure 8B, an initial movement process is performed to feed the pipe member 30 into the existing pipe 90. Prior to the initial movement process, the cable 96b pulled out from the winch 96a is extended through the second shaft 92 and the existing pipe 90 to the first shaft 91 and attached to the pipe member 30. In the initial movement process, the pulling force from the winch 96a is transmitted to the pipe member 30 via the cable 96b, and the pipe member 30 may be pulled into the existing pipe 90. Unlike the illustrated example, the pipe member 30 may be pushed into the existing pipe 90 by the drive device 96.

[0075] After the initial moving process, or in parallel with the initial moving process, a loading process is carried out to load the pipe member 30 into the first vertical shaft 91, as shown in Figure 8B. In the loading process, the pipe member 30 may be loaded into the first vertical shaft 91 using a crane device 95a.

[0076] Next, a connection process is performed in which one pipe member 30 is connected to another pipe member 30. In the illustrated example, the pipe member 30 that was sent into the existing pipe 90 in the initial moving process is connected to the pipe member 30 that was brought into the first vertical shaft 91 after the said pipe member 30.

[0077] The connection process may include a placement process and a fixing process. In the placement process, the other pipe member 30, which is brought into the first vertical shaft 91 later, is positioned relative to the other pipe member 30, which is brought into the first vertical shaft 91 earlier. As shown in Figure 8B, the two pipe members 30 are positioned so that the flange portion 55 of the second joint 40B of one pipe member 30 and the flange portion 55 of the first joint 40A of the other pipe member 30 face each other.

[0078] As shown in Figure 8C, in the fixing process, the other pipe member 30, which is brought into the first vertical shaft 91 later, is fixed to the other pipe member 30, which is brought into the first vertical shaft 91 earlier. As shown in Figure 2, the flange portion 55 of the second joint 40B of one pipe member 30 and the flange 55 of the first joint 40A of the other pipe member 30 are fixed using a fixing device 20.

[0079] In the illustrated example, a plate 60 is used to fix the two flange portions 55. The first plate portion 61 and the second plate portion 62 shown in Figure 7 are placed on the first pipe portion 51 of the second joint 40B of one pipe member 30. The plate 60, consisting of the first plate portion 61 and the second plate portion 62, is located on the first pipe portion 51 of the second joint 40B and surrounds the first pipe portion 51 in a ring shape in the circumferential direction. The plate 60 is in surface contact with the flange portion 55 of the second joint 40B. Similarly, the first plate portion 61 and the second plate portion 62 are placed on the first pipe portion 51 of the first joint 40A of the other pipe member 30. The plate 60, consisting of the first plate portion 61 and the second plate portion 62, is located on the first pipe portion 51 of the first joint 40A and surrounds the first pipe portion 51 in a ring shape in the circumferential direction. The plate 60 is in surface contact with the flange portion 55 of the first joint 40A.

[0080] As shown in Figure 2, a plate 60 located on the second joint 40B of one pipe member 30, the flange portion 55 of the second joint 40B of one pipe member 30, the flange portion 55 of the first joint 40A of the other pipe member 30, and a plate 60 located on the first joint 40A of the other pipe member 30 are arranged in order along the longitudinal direction of the existing pipe 90. Bolt through holes 63 are formed in the plate 60, and bolt through holes 56 are formed in the flange portion 55. Bolts 21 are inserted into the bolt through holes 63 in the plate 60 of one pipe member 30, the bolt through holes 56 in the flange portion 55 of one pipe member 30, the bolt through holes 56 in the flange portion 55 of the other pipe member 30, and the bolt through holes 63 in the plate 60 of the other pipe member 30. The bolts 21 may be inserted from either the plate 60 of one pipe member 30 or the other pipe member 30. The flange portions 55 of the two pipe members 30 are fixed by tightening the nut 22 onto the bolt 21. By fixing the flange portions 55 of the two pipe members 30, the two pipe members 30 can be connected.

[0081] Since the fixing state of the two flange portions 55 can be easily confirmed, the two pipe members 30 can be connected more securely. The fixing process of mechanically fixing the two flange portions 55 using the fixing device 20 can significantly reduce the space required for the work compared to fusing the two pipe members 30. Therefore, the fixing process can be easily and stably carried out inside the first shaft 91. Furthermore, the fixing process of mechanically fixing the two flange portions 55 can be carried out regardless of the presence or absence of liquid such as water. Therefore, the fixing process can be carried out even inside the first shaft 91 where groundwater is seeping out or where it is not possible to remove liquid such as water.

[0082] A plate 60 is used on the two flange portions 55. The two flange portions 55 are held between a pair of plates 60. By interposing the plates 60, the fastening force from the fastener 20 is transmitted to the flanges 55 over a wider area. As the plates 60 press against the flange portions 55 over their surface, the two flange portions 55 are sealed not only in the vicinity of the fastener 20 but also in the area facing the plates 60. Therefore, leakage between the two pipe members 30 can be effectively suppressed.

[0083] Furthermore, a sealing member such as a sheet packing, gasket, or O-ring may be interposed between two adjacent pipe members 30. By using a sealing member, leakage between the two pipe members 30 can be effectively suppressed.

[0084] After the coupling process is completed, a moving process is performed as shown in Figure 8D. In the moving process, one pipe member 30 and the other pipe members 30, which are coupled together, are fed into the existing pipe 90. In the moving process, the pulling force from the winch 96a may be transmitted to the pipe members 30 via the cable 96b, causing the pipe members 30 to be pulled into the existing pipe 90. Unlike the illustrated example, the pipe members 30 may be pushed into the existing pipe 90 by the drive device 96.

[0085] The pipe member 30 has a flange portion 55 for mechanically fixing it to other pipe members 30. The flange portion 55 protrudes radially outward from the first pipe portion 51 of the joint 40. However, the outer width 55x of the flange portion 55 is less than or equal to the outer width 52x of the second pipe portion 52 of the joint 40. In the illustrated example, the outer width 55x of the flange portion 55 is less than or equal to the outer width 35x of the pipe 35. The outer width 55x of the flange portion 55 is less than the outer width 52x of the second pipe portion 52 of the joint 40. The outer width 55x of the flange portion 55 is less than the outer width 35x of the pipe 35. Therefore, the flange portion 55 can suppress an increase in the maximum outer diameter of the pipe member 30.

[0086] This configuration makes it possible to prevent the flange portion 55 of the joint 40 from coming into contact with the existing pipe 90 during the moving process. Therefore, it is possible to prevent the flange portion 55 of the pipe member 30 from getting caught on the existing pipe 90, and the pipe member 30 from moving smoothly within the existing pipe 90. The existing pipe 90 may have damage such as bends or cracks. When the pipe member 30 moves within the existing pipe 90 where damage has occurred, the pipe member 30 is very likely to get caught on the existing pipe 90. The configuration in which the outer width 55x of the flange portion 55 is less than or equal to the outer width 52x of the second pipe portion 52 of the joint 40 is suitable for laying the pipe structure 10 within the existing pipe 90 where damage has occurred.

[0087] On the other hand, the outer width 52x of the second pipe section 52 of the joint 40 is greater than or equal to the outer width 55x of the flange section 55. In the illustrated example, the outer width 35x of the pipe 35 is greater than or equal to the outer width 55x of the flange section 55. The outer width 52x of the second pipe section 52 of the joint 40 is greater than the outer width 55x of the flange section 55. The outer width 35x of the pipe 35 is greater than the outer width 55x of the flange section 55. Therefore, miniaturization of the pipe 35 can be suppressed. Therefore, the reduction in the amount of fluid transported using the pipe structure 10 can be suppressed.

[0088] The illustrated pipe member 30 includes a tapered section 53 between a first pipe section 51 and a second pipe section 52. The tapered section 53 connects the first pipe section 51 and the second pipe section 52. The outer width 55x of the tapered section 55 gradually decreases from the second pipe section 52 toward the first pipe section 51. The outer surface 53a of the tapered section 53 is inclined at an angle θa greater than 0° and less than or equal to 60° with respect to the axial direction D1 in which the first pipe section 51 and the second pipe section 52 face each other.

[0089] By providing the flange portion 55, it is possible to more effectively prevent the flange portion 55 from getting caught on the existing pipe 90 during the movement process. The movement of the pipe member 30 within the existing pipe 90 can be made smoother. Furthermore, during the movement process, external forces such as tensile force are applied to the pipe member 30. By providing the tapered portion 53, it is possible to suppress the occurrence of stress concentration points between the first pipe section and the second pipe section. Moreover, while the pipe structure 10 is in use, the fluid passing through the pipe structure 10 may be pressurized. In such cases as well, it is possible to suppress the occurrence of stress concentration points between the first pipe section and the second pipe section.

[0090] In the illustrated example, the inner width 55y of the tapered section 55 gradually decreases from the second pipe section 52 toward the first pipe section 51. The inner surface 53b of the tapered section 53 is inclined at an angle θb greater than 0° and less than or equal to 60° with respect to the axial direction D1 in which the first pipe section 51 and the second pipe section 52 face each other. With this configuration, it is possible to suppress the occurrence of stress concentration points between the first pipe section 51 and the second pipe section 52 during the moving process. Furthermore, it is possible to stabilize the fluid flow within the pipe structure 10 while the pipe structure 10 is in use.

[0091] The loading process, connection process, and movement process described above are repeated as shown in Figures 8E to 8G. By carrying out the loading process, connection process, and movement process, one pipe member 30 is loaded into the first vertical shaft 91, connected with another pipe member 30 within the first vertical shaft 91, and then sent into the existing pipe 90. As a result, the total length of the pipe structure 10 within the existing pipe 90 is increased by the length of the pipe member 30 loaded into the first vertical shaft 91. By repeatedly carrying out the loading process, connection process, and movement process, the pipe structure 10 can be laid within the existing pipe 90 as shown in Figure 1.

[0092] In the embodiment described above, the joint 40 is used in a pipe member 30 that is placed inside an existing pipe 90. The joint 40 includes a first pipe section 51, a second pipe section 52 that is thicker than the first pipe section 51, and a flange section 55 provided on the first pipe section 51. The outer width 55x of the flange section 55 is less than or equal to the outer width 52x of the second pipe section 52.

[0093] In the embodiment described above, the pipe member 30 is placed inside the existing pipe 90. The pipe member 30 includes a joint 40 and a pipe 35 connected to the joint 40A. The joint 40 includes a first pipe section 51, a second pipe section 52 which is thicker than the first pipe section 51, and a flange section 55 provided on the first pipe section 51. The outer width 55x of the flange section 55 is less than or equal to the outer width 52x of the second pipe section 52. The pipe 35 is connected to the second pipe section 52 of the joint 40. The outer width 35x of the pipe 35 is greater than or equal to the outer width 55x of the flange section 55.

[0094] In the embodiment described above, the pipe member 30 is placed inside the existing pipe 90. The pipe member 30 includes a first joint 40A, a second joint 40B, and a pipe 35 located between the first joint 40A and the second joint 40B. The first joint 40A and the second joint 40B each include a first pipe section 51, a second pipe section 52 which is thicker than the first pipe section 51, and a flange section 55 provided on the first pipe section 51. The outer width 55x of the flange section 55 is less than or equal to the outer width 52x of the second pipe section 52. The second pipe section 52 of the first joint 40A is connected to the first end 35a of the pipe 35. The second pipe section 52 of the second joint 40B is connected to the second end 35b of the pipe 35. The outer width 35x of pipe 35 is greater than or equal to the outer width 55x of the flange portion 55 of the first joint 40A, and also greater than or equal to the outer width 55x of the flange portion 55 of the second joint 40B.

[0095] In the embodiment described above, the pipe structure 10 is placed inside the existing pipe 90. The pipe structure 10 includes a plurality of pipe members 30. The pipe members 30 are the pipe members 30 according to the embodiment described above. The plurality of pipe members 30 are arranged in order in one direction DA. Two pipe members 30 adjacent to each other in one direction DA are connected by fixing the flange portion 55 of the second joint 40B of one pipe member 30 and the flange portion 55 of the first joint 40A of the other pipe member 30 with a fastener 20.

[0096] In the joint 40, pipe member 30, and pipe structure 10 according to this embodiment, the joint 40 includes a flange portion 55. Two pipe members 30 can be connected by mechanically fixing the flange portion 55 using the flange portion 55. Electrical equipment and the like can be eliminated for connecting the two pipe members 30. Therefore, the two pipe members 30 can be connected even in narrow places such as inside a vertical shaft 91 or underwater. In addition, in this embodiment, the outer width 55x of the flange portion 55 is less than or equal to the outer width 52x of the second pipe portion 52. Therefore, even if the existing pipe 90 is bent or damaged, the flange portion 55 can be prevented from getting caught on the existing pipe 90 when the pipe member 30 moves inside the existing pipe 90. The outer width 52x of the second pipe portion 52 is greater than or equal to the outer width 55x of the flange portion 55. Therefore, the miniaturization of the pipe member 30 can be suppressed while suppressing interference between the flange portion 55 of the joint 40 and the existing pipe 90. As a result, the newly constructed pipe structure 10, with its larger outer and inner widths, can be easily and stably laid inside the existing pipe 90.

[0097] In one specific example of the embodiment described above, the joint 40 may further include a tapered portion 53 located between the first pipe section 51 and the second pipe section 52. The outer width 53x of the tapered portion 53 decreases from the second pipe section 52 toward the first pipe section 51. The provision of the tapered portion 53 makes it possible to more effectively suppress the flange portion 55 from catching on the existing pipe 90 when moving the pipe member 30 within the existing pipe 90. It is possible to suppress the occurrence of a stress concentration point between the first pipe section 51 and the second pipe section 52 when moving the pipe member 30 including the joint 40 within the existing pipe 90. It is possible to suppress the occurrence of a stress concentration point between the first pipe section 51 and the second pipe section 52 when the fluid passing through the pipe structure 10 constructed using the pipe member 30 is pressurized.

[0098] In the above-described specific example of this embodiment, the outer surface 53a of the tapered portion 53 is inclined at an inclination angle θa greater than 0° and 60° or less with respect to the axial direction D1 in which the first pipe portion 51 and the second pipe portion 52 face each other. According to this specific example, when moving the pipe member 30 including the joint 40 within the existing pipe 90, the flange portion 55 can be more effectively prevented from catching on the existing pipe 90. The occurrence of stress concentration points between the first pipe portion 51 and the second pipe portion 52 can be more effectively prevented. When the fluid passing through the pipe structure 10 constructed using the pipe member 30 is pressurized, the occurrence of stress concentration points between the first pipe portion 51 and the second pipe portion 52 can be more effectively prevented. In order to expect the above effects, the inclination angle θa may be 60° or less, 45° or less, or 30° or less, as described above.

[0099] In one specific example of the above embodiment, the joint 40 may further include a tapered section 53 located between the first pipe section 51 and the second pipe section 52. The inner width 53y of the tapered section 53 decreases from the second pipe section 52 toward the first pipe section 51. By providing the tapered section 53, when fluid flows through the pipe member 30, it is possible to suppress the occurrence of flow turbulence and stagnation points between the first pipe section 51 and the second pipe section 52. When the pipe member 30 including the joint 40 is moved within the existing pipe 90, it is possible to suppress the occurrence of stress concentration points between the first pipe section 51 and the second pipe section 52. When the fluid passing through the pipe structure 10 constructed using the pipe member 30 is pressurized, it is possible to suppress the occurrence of stress concentration points between the first pipe section 51 and the second pipe section 52.

[0100] In the above-described specific example of this embodiment, the inner surface 53b of the tapered portion 53 of the joint 40 is inclined at an angle θb greater than 0° and less than or equal to 60° with respect to the axial direction D1 in which the first pipe portion 51 and the second pipe portion 52 face each other. According to this specific example, when fluid flows through the pipe member 30, it is possible to suppress the occurrence of flow turbulence and stagnation points between the first pipe portion 51 and the second pipe portion 52. When the pipe member 30 including the joint 40 is moved within the existing pipe 90, it is possible to suppress the occurrence of stress concentration points between the first pipe portion 51 and the second pipe portion 52. When the fluid passing through the pipe structure 10 constructed using the pipe member 30 is pressurized, it is possible to suppress the occurrence of stress concentration points between the first pipe portion 51 and the second pipe portion 52. In order to expect the above effects, the inclination angle θb may be 60° or less, 45° or less, or 30° or less, as described above.

[0101] In one specific example of the embodiment described above, the pipe member 30 may further include a plate 60 located on the first pipe section 51. The plate 60 is located between the flange section 55 and the second pipe section 52. The plate 60 is made of metal. The plate 60 is provided with bolt holes 63 through which the bolts 21 pass. The flange section 55 is made of resin. The flange section 55 is provided with bolt holes 56 through which the bolts 21 pass. In this specific example, the plate 60 presses against the flange section 55 in a planar manner, thereby sealing the flange section 55 and the other pipe member 30 not only in the vicinity of the bolts 21 but also in the area facing the plate 60. Therefore, leakage between the two pipe members 30 can be effectively suppressed.

[0102] In the above-described specific example of this embodiment, the plate 60 may include a first plate portion 61 and a second plate portion 62. The plate 60 is an annular shape that surrounds the first pipe portion 51 by the combination of the first plate portion 61 and the second plate portion 62. The inner width 60y of the plate is greater than or equal to the outer width 51x of the first pipe portion 51. The outer width 60x of the plate 60 is less than or equal to the outer width 52x of the second pipe portion 52. According to this specific example, the plate 60 presses against the flange portion 55 with its surface, thereby sealing the flange portion 55 and other pipe members not only in the vicinity of the bolt 21 but also in the annular region facing the plate 60. Therefore, leakage between the two pipe members 30 can be effectively suppressed. Furthermore, the outer width 60x of the annular plate 60 is less than or equal to the outer width 52x of the second pipe portion 52. Therefore, even if the existing pipe 90 is bent or damaged, the plate 60 can be prevented from getting caught on the existing pipe 90 when the pipe member 30 moves inside the existing pipe 90.

[0103] In one specific example of the above embodiment, the pipe member 30 may further include an annular plate 60 that includes a through hole 65 through which the first pipe section 51 passes. The inner width 60y of the plate 60 is greater than or equal to the outer width 51x of the first pipe section 51. The outer width 60x of the plate 60 is less than or equal to the outer width 52x of the second pipe section 52. The plate 60 is made of metal. The flange section 55 is made of resin. According to this specific example, the plate 60 presses against the flange section 55 with its surface, thereby sealing the flange section 55 and the other pipe members not only in the vicinity of the bolt 21 but also in the annular region facing the plate 60. Therefore, leakage between the two pipe members 30 can be effectively suppressed. Also, the outer width 60x of the annular plate 60 is less than or equal to the outer width 52x of the second pipe section 52. Therefore, even if the existing pipe 90 is bent or damaged, the plate 60 can be prevented from getting caught on the existing pipe 90 when the pipe member 30 moves inside the existing pipe 90.

[0104] In the embodiment described above, the method for connecting the pipe members is a method for connecting two pipe members 30 according to this embodiment. The connection method includes an arrangement step and a fixing step. In the arrangement step, the two pipe members 30 are arranged so that the flange portion 55 of the second joint 40B of one pipe member 30 faces the flange portion 55 of the first joint 40A of the other pipe member 30. In the fixing step, the two pipe members 30 are connected by fixing the flange portion 55 of the second joint 40B of one pipe member 30 and the flange portion 55 of the first joint 40A of the other pipe member 30 with a fixing device 20.

[0105] In the embodiment described above, the method for manufacturing the pipe structure is a method for manufacturing a pipe structure including a plurality of pipe members connected to each other inside an existing pipe. The manufacturing method includes a connection step of connecting two pipe members 30 and a moving step of feeding the two connected pipe members 30 into the existing pipe 90. In the connection step, the two pipe members 30 are connected by the pipe member connection method according to this embodiment. The connection step and the moving step are repeated.

[0106] According to the method for connecting pipe members and manufacturing a pipe structure according to this embodiment, two pipe members 30 can be mechanically connected by fixing the flange portions 55 of the two facing pipe members 30 with a fixing device 20. Electrical equipment and the like can be eliminated for connecting the two pipe members 30. Therefore, the two pipe members 30 can be connected even in narrow places such as inside a shaft or underwater. In addition, in this embodiment, the outer width 55x of the flange portion 55 is less than or equal to the outer width 52x of the second pipe portion 52. Therefore, even if the existing pipe 90 is bent or damaged, the flange portion 55 can be prevented from getting caught on the existing pipe 90 when the pipe member 30 moves inside the existing pipe 90. The outer width 52x of the second pipe portion 52 is greater than or equal to the outer width 55x of the flange portion 55. Therefore, the miniaturization of the pipe member 30 can be suppressed while suppressing interference between the flange portion 55 of the joint 40 and the existing pipe 90. As a result, the newly constructed pipe structure 10, with its larger outer and inner widths, can be easily and stably laid inside the existing pipe 90.

[0107] In one specific example of the above embodiment, in the process of connecting the pipe members 30, the two pipe members 30 may be connected using a bolt 21 that passes through, in order, a plate 60 located on the second joint 40B of one pipe member 30, the flange portion 55 of the second joint 40B of one pipe member 30, the flange portion 55 of the first joint 40A of the other pipe member 30, and a plate 60 located on the first joint 40A of the other pipe member 30. In this specific example, the flange portions 55 of the two pipe members 30 are sandwiched between the pair of plates 60. Therefore, the two flange portions 55 are sealed not only in the vicinity of the bolt 21 but also in a wider area facing the plate 60. Thus, leakage between the two pipe members 30 can be effectively suppressed.

[0108] This embodiment has been described with reference to specific examples, but the above-mentioned examples do not limit this embodiment. The above-described embodiment can be implemented in various other examples, and various omissions, substitutions, modifications, and additions can be made without departing from its essence.

[0109] An example of modification will be described below with reference to the drawings. In the following explanation and the drawings used therein, parts that can be configured in the same way as in the specific example described above will be given the same reference numerals as those used for the corresponding parts in the specific example described above, and redundant explanations will be omitted.

[0110] As shown in Figures 9 to 11, the pipe structure 10 may include a cover 70 that covers the joint portion of the two pipe members 30. As shown in Figure 9, the cover 70 covers the flange portion 55 of the joint 40 fixed to each other by the two pipe members 30. The cover 70 may cover the joint 40 along its entire length in the axial direction D1. The cover 70 may partially cover the joint 40 in the axial direction D1. The cover 70 may cover the joint 40 along its entire circumference in the circumferential direction. The cover 70 may partially cover the joint 40 in the circumferential direction.

[0111] The cover 70 can smooth out radial irregularities in the pipe member 30 caused by the joint 40. The cover 70 can cover and conceal radial irregularities in the pipe member 30 caused by the joint 40. The cover 70 allows the pipe member 30 to move more smoothly within the existing pipe 90. The surface of the cover 70 may be flat. The cover 70 may be a flexible sheet-like member made of resin or metal.

[0112] The pipe structure 10 may include a fixing member 71 for fixing the cover 70 to the pipe member 30. The fixing member 71 is not particularly limited. The fixing member 71 may be an adhesive sheet or bonding sheet, or an adhesive or bonding agent.

[0113] In the example shown in Figure 9, the cover 70 covers the second joint 40B of one pipe member 30 and the first joint 40A of the other pipe member 30 along their entire length in the longitudinal direction DA. The cover 70 covers the second joint 40B of one pipe member 30 and the first joint 40A of the other pipe member 30 along their entire circumference in the circumferential direction. The cover 70 is a sheet-like material. As shown in Figure 10, the cover 70, as a single sheet-like material, may be wrapped around the pipe structure 10. As shown in Figure 11, the sheet-like cover 70 wrapped around the pipe structure 10 may be divided into multiple sections in the circumferential direction.

[0114] The fixing member 71 secures the end of the cover 70 in the axial direction D1 to the pipe member 30. The fixing member 71 secures the end of the cover 70 in the longitudinal direction DA to the pipe member 30 along its entire circumference.

[0115] As another modification, the tapered portion 53 may be omitted from the joint 40, as shown in Figure 12. In the joint 40 shown in Figure 12, the first pipe portion 51 and the second pipe portion 52 are in contact in the axial direction D1 and are directly connected.

[0116] The outer width 51x and outer diameter 51x of the first pipe section 51 do not have to be constant in the axial direction D1. The inner width 51y and inner diameter 51y of the first pipe section 51 do not have to be constant in the axial direction D1. The outer width 52x and outer diameter 52x of the second pipe section 52 do not have to be constant in the axial direction D1. The inner width 52y and inner diameter 52y of the second pipe section 52 do not have to be constant in the axial direction D1. In the example shown in Figure 12, the inner width 52y and inner diameter 52y of the second pipe section 52 gradually decrease in a portion of the axial direction D1 as it approaches the first pipe section 51 in the axial direction D1. [Explanation of Symbols]

[0117] DA: longitudinal direction, D1: axial direction, D2: radial direction, D3: circumferential direction, 10: pipe structure, 20: fastener, 21: bolt, 22: nut, 30: pipe member, 35: pipe, 35a: first end, 35b: second end, 40A: first joint, 40B: second joint, 40: joint, 51: first pipe section, 52: second pipe section, 53: tapered section, 53a: outer surface, 53b: inner surface 55: Flange section, 56: Bolt through hole, 60: Plate, 61: First plate section, 62: Second plate section, 63: Bolt through hole, 65: Through hole, 70: Cover, 71: Fixing member, 90: Existing pipe, 91: First shaft, 92: Second shaft, 95: Loading device, 95a: Crane device, 96: Drive device, 96a: Winch, 96b: Cable

Claims

1. A joint used in pipe members placed inside an existing pipe, The first pipe section and, A second pipe section which is thicker than the first pipe section, The device comprises a flange portion provided on the first pipe portion, A joint in which the outer width of the flange portion is less than or equal to the outer width of the second pipe portion.

2. The structure further comprises a tapered section located between the first and second pipe sections, The joint according to claim 1, wherein the outer width of the tapered portion decreases from the second pipe portion toward the first pipe portion.

3. The joint according to claim 2, wherein the outer surface of the tapered portion is inclined at an angle greater than 0° and less than or equal to 60° with respect to the axial direction in which the first pipe portion and the second pipe portion face each other.

4. The structure further comprises a tapered section located between the first and second pipe sections, The joint according to claim 1, wherein the inner width of the tapered portion decreases from the second pipe portion toward the first pipe portion.

5. The joint according to claim 4, wherein the inner surface of the tapered portion is inclined at an angle greater than 0° and less than or equal to 60° with respect to the axial direction in which the first pipe portion and the second pipe portion face each other.

6. A pipe member that is placed inside an existing pipe, A first joint which is a joint described in any one of claims 1 to 5, A second joint which is a joint described in any one of claims 1 to 5, A pipe located between the first joint and the second joint, The second pipe section of the first joint and the first end of the pipe are connected, The second pipe section of the second joint and the second end of the pipe are connected, A pipe member wherein the outer width of the pipe is greater than or equal to the outer width of the flange portion of the first joint, and greater than or equal to the outer width of the flange portion of the second joint.

7. The first pipe section further comprises a plate located on the first pipe section, The plate is located between the flange portion and the second pipe portion, The aforementioned plate is made of metal and is provided with bolt holes through which bolts pass. The pipe member according to claim 6, wherein the flange portion is made of resin and is provided with a bolt through hole through which the bolt passes.

8. The plate includes a first plate portion and a second plate portion, The plate is an annular shape that surrounds the first pipe section by a combination of the first plate section and the second plate section. The inner width of the plate is greater than or equal to the outer width of the first pipe section. The pipe member according to claim 7, wherein the outer width of the plate is less than or equal to the outer width of the second pipe portion.

9. The device further comprises an annular plate including a through hole through which the first pipe section passes, The inner width of the plate is greater than or equal to the outer width of the first pipe section. The outer width of the plate is less than or equal to the outer width of the second pipe section. The aforementioned plate is made of metal, The pipe member according to claim 6, wherein the flange portion is made of resin.

10. A pipe structure to be placed inside an existing pipe, The plurality of pipe members described in claim 6, The aforementioned plurality of pipe members are arranged in order in one direction, A pipe structure in which two pipe members adjacent to each other in one direction are connected by fixing the flange portion of the second joint of one pipe member to the flange portion of the first joint of the other pipe member with a fastener.

11. A method for connecting two pipe members as described in claim 6, The process involves arranging the two pipe members such that the flange portion of the second joint of one pipe member faces the flange portion of the first joint of the other pipe member. A method for connecting pipe members, comprising the step of connecting two pipe members by fixing the flange portion of the second joint of one pipe member and the flange portion of the first joint of the other pipe member with a fastener.

12. The method for connecting pipe members according to claim 11, wherein in the step of connecting the two pipe members, the two pipe members are connected using a bolt that passes through, in order, a plate located on the second joint of one pipe member, the flange portion of the second joint of the one pipe member, the flange portion of the first joint of the other pipe member, and a plate located on the first joint of the other pipe member.

13. A method for manufacturing a pipe structure including multiple pipe members connected to each other within an existing pipe, A connection step of connecting the two pipe members by the method for connecting pipe members described in claim 11, The process includes a step of moving the two pipe members, which are connected to each other, into the existing pipe, A method for manufacturing a pipe structure, comprising repeatedly performing the aforementioned connecting step and the aforementioned moving step.

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