Fittings and piping structures

Abstract

To provide a joint that adjusts a direction of a pipe conduit, and into which a cable or the like is easily inserted, and a pipe structure.SOLUTION: A joint 30 connects a first protection pipe 10 and a second protection pipe 20. The joint 30 comprises a first tubular member 31 that has at one end a first socket 31a through which a first protection pipe 10 is passed, and a first fitting part 33 at the other end, and that extends along a first pipe axis D1. The joint 30 comprises a tubular second member 32 that has at one end a second socket 32a through which a second protection pipe 20 is passed, and a second fitting part 34 at the other end, and the extends along a second pipe axis D2. The first fitting part 33 and the second fitting part 34 are fitted, and the first member 31 and the second member 32 are relatively rotatable at a predetermined bending angle θ around an intersection X between the first pipe axis D1 and the second pipe axis D2. A distance L1 from the intersection X to the end part of the first socket 31a and a distance L2 from the intersection X to the end part of the second socket 32a are 40 mm or more and 250 mm or less.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to joints and piping structures.

Background Art

[0002] Conventionally, in a piping structure of a protective pipe for protecting a cable, there has been a piping structure in which protective pipes are connected to each other by a joint and the piping direction can be adjusted (see Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The conventional piping structure with an adjustable piping direction has a structure in which protective pipes are connected to each other by a joint. Therefore, in a piping structure where the piping direction is bent, a step occurs between the ends of the protective pipes inside the joint, and it may be difficult to insert a test rod for a conduction test having a straight cylindrical shape with an outer diameter and length simulating a linear cable having a circular cross section or a cable to be inserted into the piping structure (hereinafter referred to as a cable or the like).

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a joint and a piping structure that can adjust the piping direction and are easy to insert a cable or the like.

Means for Solving the Problems

[0006] The means for solving the above problems are as follows. (1) A joint according to one aspect of the present invention is a joint for connecting a first protective pipe and a second protective pipe, comprising: a tubular first member extending along a first pipe axis, having a first socket at one end through which the first protective pipe passes and a first fitting portion at the other end; and a tubular second member extending along a second pipe axis, having a second socket at one end through which the second protective pipe passes and a second fitting portion at the other end, wherein the first fitting portion and the second fitting portion are fitted together, the first member and the second member are rotatable relative to each other at a predetermined bending angle about the intersection of the first pipe axis and the second pipe axis, and the distance from the intersection to the end of the first socket and the distance from the intersection to the end of the second socket are 40 mm or more and 250 mm or less. (2) The above (1) may have a restricting part that restricts the bending angle. (3) In (1) or (2) above, the first fitting portion has a first spherical surface on its outer circumferential surface, and the second fitting portion has a second spherical surface on its inner circumferential surface, and the first spherical surface and the second spherical surface may be in slidable contact. (4) In any of (1) to (3) above, the first fitting portion has a ring-shaped projection that extends in an annular shape along the circumferential direction centered on the first pipe axis and protrudes toward the second member along the first pipe axis, and the second fitting portion has an annular groove that extends in an annular shape along the circumferential direction centered on the second pipe axis and is recessed toward the direction away from the first member along the second pipe axis, and the ring-shaped projection and the annular groove can be fitted together. (5) In any of (1) to (4) above, the distance from the intersection to the end of the first socket and the distance from the intersection to the end of the second socket may be the same. (6) In any of (1) to (5) above, a stopper is provided to restrict relative movement of the joint toward the intersection of the first protective pipe and the second protective pipe, wherein the stopper may include a first stopper positioned on the first socket side of the intersection and at a distance of 40 mm or more from the end of the first socket, and a second stopper positioned on the second socket side of the intersection and at a distance of 40 mm or more from the end of the second socket. (7) In any of (1) to (6) above, there may be a first seal ring disposed between the first member and the first protective tube, and a second seal ring disposed between the second member and the second protective tube. (8) In (7) above, the distance from the intersection to the first seal ring and the distance from the intersection to the second seal ring may be 40 mm or more and 250 mm or less. (9) A piping structure according to one aspect of the present invention includes the first protective pipe, the second protective pipe, and any of the fittings described in (1) to (8) above, wherein the first protective pipe and the second protective pipe are provided, the other end of the first protective pipe is located on the first socket side of the intersection, and the other end of the second protective pipe is located on the second socket side of the intersection. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a joint and piping structure that allows for adjustment of the conduit direction and facilitates the insertion of cables and the like. [Brief explanation of the drawing]

[0008] [Figure 1] This is an explanatory diagram showing a joint according to the first embodiment in a state where the pipe direction is straight. [Figure 2] This is an explanatory diagram showing a joint according to the first embodiment in a state where the pipe direction is bent. [Figure 3] This is an explanatory diagram showing a piping structure according to the first embodiment in a state where the direction of the pipeline is bent. [Figure 4] This is an explanatory diagram showing a joint according to the second embodiment, where the pipe direction is straight. [Figure 5] This is an explanatory diagram showing a joint according to the second embodiment in a state where the pipe direction is bent. [Figure 6] This is a detailed explanatory diagram of section A in Figure 5. [Modes for carrying out the invention]

[0009] (First Embodiment) The joint 30 and piping structure 1 according to the first embodiment will be described below with reference to the drawings. Figure 1 is an explanatory diagram showing the joint 30 according to the first embodiment in a state where the pipe direction D is straight. Figure 2 is an explanatory diagram showing the joint 30 according to the first embodiment in a state where the pipe direction D is bent. Figure 3 is an explanatory diagram showing the piping structure 1 according to the first embodiment in a state where the pipe direction D is bent. Figures 1 to 3 show cross-sections including the pipe direction D (the first pipe axis D1 of the first member 31 and the second pipe axis D2 of the second member 32).

[0010] (Piping structure) As shown in Figures 1 to 3, the piping structure 1 according to the first embodiment includes a joint 30 comprising a first protective pipe 10 and a second protective pipe 20. The other end of the first protective pipe 10 is positioned on the side of the first socket 31a from intersection X. The other end of the second protective pipe 20 is positioned on the side of the second socket 32a from intersection X. This prevents the formation of a step between the first end 11 of the first protective pipe 10 and the second end 21 of the second protective pipe 20 that would hinder the conduction of cables, etc., when the joint 30 is bent.

[0011] The piping structure 1 may be a series of interconnected piping structures 1, each consisting of a first protective pipe 10 and a second protective pipe 20 connected by a joint 30. The piping structure 1 may also consist of protective pipes and joints 30 connected alternately. The lengths of the first protective pipe 10, the second protective pipe 20, and the joint 30 (dimensions along the pipe axis) are appropriately set according to the outer diameter, curvature, and angle of the cable, etc., that passes through the conduit (a cylindrical space formed inward along the pipe axis through which the cable, etc., passes) formed by the piping structure 1, as well as the inner diameter, curvature, and angle of the conduit. For example, as shown in Figure 3, the piping structure 1 may be constructed by connecting the second protective pipe 20, joint 30, first protective pipe 10, joint 30, and second protective pipe 20 in that order. This makes it possible to create a piping structure 1 that forms a conduit with a desired curvature and angle.

[0012] The first protective tube 10 or the second protective tube 20 may be a so-called straight tube with a uniform inner diameter, outer diameter, and wall thickness along the tube axis. The first protective tube 10 and the second protective tube 20 may have the same size. By connecting the first protective tube 10 and the second protective tube 20 via the joint 30, even if the first protective tube 10 or the second protective tube 20 is a straight tube, a bent pipeline can be formed inside the piping structure 1 through which a bent cable or the like can be inserted and arranged.

[0013] (Joint) As shown in FIGS. 1 to 3, the joint 30 according to the first embodiment is a joint 30 that connects the first protective tube 10 and the second protective tube 20. The joint 30 includes a tubular first member 31 extending along the first tube axis D1, having a first receiving port 31a through which the first protective tube 10 passes at one end and a first fitting portion 33 at the other end. The joint 30 includes a tubular second member 32 extending along the second tube axis D2, having a second receiving port 32a through which the second protective tube 20 passes at one end and a second fitting portion 34 at the other end. The first fitting portion 33 and the second fitting portion 34 are fitted together, and the first member 31 and the second member 32 are relatively rotatable about the intersection X of the first tube axis D1 and the second tube axis D2 at a predetermined bending angle θ. Here, the distance L1 from the intersection X to the end of the first receiving port 31a and the distance L2 from the intersection X to the end of the second receiving port 32a are 40 mm or more and 250 mm or less. Therefore, the first protective tube 10 and the second protective tube 20 can be inserted into the joint 30 by an appropriate amount and overlapped without exceeding the intersection X. Thereby, while ensuring the bonding strength by adhesion or the followability with respect to the displacement assumed during an earthquake between the joint 30 and the first protective tube 10 and the second protective tube 20, a pipeline along a curvature radius of about 5 m can be formed. Also, the pipeline direction D can be bent without generating a step that hinders the conduction of a cable or the like between the first end 11 of the first protective tube 10 and the second end 21 of the second protective tube 20. Therefore, a piping structure 1 with an adjustable pipeline direction D and easy to insert a cable or the like can be provided.

[0014] Preferably, the distance L1 from the intersection point X to the end of the first receiving port 31a and the distance L2 from the intersection point X to the end of the second receiving port 32a are the same. Thereby, when the lengths of the first member 31 and the second member 32 are the same, one of the first protective tube 10 and the second protective tube 20 will not exceed the intersection point X, and a step that may prevent the passage of a cable or the like will not occur at the portion where the first end 11 of the first protective tube 10 and the second end 21 of the second protective tube 20 face each other.

[0015] (First member) The first member 31 is a tubular body. The first member 31 is a rotating body that extends along the first tube axis D1 and is centered on the first tube axis D1. The first member 31 has a first receiving port 31a through which the first protective tube 10 passes at one end. The first member 31 has a first fitting portion 33 that fits into the second fitting portion 34 of the second member 32 at the other end. In this way, the first fitting portion 33 is rotatable in a state of being fitted to the second fitting portion 34. The joint 30 is rotatable by the first fitting portion 33 and the second fitting portion 34. Thereby, the joint 30 can change the bending angle θ formed by the first tube axis D1 of the first member 31 and the second tube axis D2 of the second member 32, and bend the pipeline direction D.

[0016] Here, the first fitting portion 33 may have a first spherical surface 33m on its outer peripheral surface. The first spherical surface 33m and the second spherical surface 34f are in slidable contact. Thereby, the first member 31 can be rotated three-dimensionally around the intersection point X with respect to the second member 32, and the pipeline direction D can be bent.

[0017] (Second member) The second member 32 is a tubular body. The second member 32 is a rotating body that extends along the second pipe axis D2 and is centered on the second pipe axis D2. The second member 32 has a second socket 32a at one end through which the second protective pipe 20 passes. The second member 32 has a second fitting portion 34 at the other end that fits into the first fitting portion 33 of the first member 31. In this way, the second fitting portion 34 is rotatable when fitted into the first fitting portion 33. The joint 30 is rotatable at the first fitting portion 33 and the second fitting portion 34. As a result, the joint 30 can change the bending angle θ between the first pipe axis D1 of the first member 31 and the second pipe axis D2 of the second member 32, thereby bending the pipeline direction D.

[0018] Here, the second fitting portion 34 may have a second spherical surface 34f on its inner circumferential surface. The first spherical surface 33m and the second spherical surface 34f are in slidable contact. This allows the second member 32 to rotate three-dimensionally around the intersection point X relative to the first member 31, and to bend the pipeline direction D. Furthermore, in order to prevent water and sand from entering the joint 30 from the outside, it is preferable to place a sealing member such as a rubber ring between the first spherical surface 33m and the second spherical surface 34f, and recesses for placing the sealing member may be provided on the first spherical surface 33m, which is the outer circumferential surface of the first fitting portion 33, or on the second spherical surface 34f, which is the inner circumferential surface of the second fitting portion 34.

[0019] (Regulatory Department) Preferably, the joint 30 has a restricting portion 40 that restricts the bending angle θ. As shown in Figure 2, the restricting portion 40 may be a projection that protrudes inward from the inner surface of the second member 32. The restricting portion 40 is located at the end of the second spherical surface 34f. When the second spherical surface 34f slides relative to the first spherical surface 33m and rotates, the end of the first member 31 (first fitting portion 33) comes into contact with the restricting portion 40, restricting further rotation. Due to the restricting portion 40, the angular range in which the first member 31 and the second member 32 can rotate relative to each other is equivalent to the bending angle θ. In this way, the joint 30 has a restricting portion 40 that restricts the bending angle θ. This prevents the joint 30 from bending at an angle so large that a step is created between the first end 11 of the first protective pipe 10 and the second end 21 of the second protective pipe 20 that would hinder the insertion of cables or the like. When the cable is a power cable, it is required that a continuity test rod with an outer diameter 10 mm smaller than the inner diameter of the conduit and a length of 400 mm be able to pass through. In this case, the upper limit of the bending angle θ is preferably 5.8°, and it is preferable that it bends within the range of 0° to 5.8°. By combining a protective tube with a length of 500 mm and a joint 30 bent at 5.75°, a piping structure 1 with a curvature of 5 mR can be made, and a continuity test rod can pass through without obstruction. When a piping structure 1 with a curvature of 5 mR is made, if multiple joints 30 are used for an effective length of 1 m, the upper limit of the bending angle θ may be less than 5.8°, and the range of the bending angle θ may be 0° to 3.9° or 0° to 2.9°. The restricting portion 40 can be arranged so as to be within the range of the bending angle θ described above, and its shape and position are not particularly limited.

[0020] (Stopper) The joint 30 may be equipped with a stopper 50 that restricts relative movement of the first protective pipe 10 and the second protective pipe 20 toward the intersection point X with respect to the joint 30. The stopper 50 may include a first stopper 51 positioned on the side of the first socket 31a from intersection X and at a distance of 40 mm or more from the end of the first socket 31a, and a second stopper 52 positioned on the side of the second socket 32a from intersection X and at a distance of 40 mm or more from the end of the second socket 32a. In particular, when the joint 30 and the first protective pipe 10 and the second protective pipe 20 are bonded together with adhesive, the bonding strength between the joint 30 and each protective pipe depends on the insertion length of the protective pipe into the socket of the joint 30 (i.e., the distance from the end of the socket to the stopper) and the nominal diameter of the protective pipe. Therefore, if the nominal diameter of the protective pipe is large, it is necessary to increase the insertion length of the protective pipe into the joint to which the adhesive is applied and bonded. Therefore, when the outer diameter of the protective tube is 90 mm or less, the distance from the end of the socket to the stopper 50 is preferably 40 mm or more; when the outer diameter of the protective tube is greater than 90 mm and 130 mm or less, the distance from the end of the socket to the stopper is preferably 50 mm or more; when the outer diameter of the protective tube is greater than 130 mm and 160 mm or less, the distance from the end of the socket to the stopper is preferably 65 mm or more; and when the outer diameter of the protective tube is greater than 160 mm and 200 mm or less, the distance from the end of the socket to the stopper is preferably 80 mm or more. If the joint 30 has seal rings 61 and 62, which will be described later, the stopper 50 may be positioned at a distance of 50 mm or more from the seal rings 61 and 62. This allows the first protective pipe 10 and the second protective pipe 20 to be inserted into the first member 31 and the second member 32 of the joint 30 by an appropriate amount, without exceeding the intersection X. Therefore, even if the joint 30 is bent, it is possible to prevent the creation of a step between the first end 11 of the first protective pipe 10 and the second end 21 of the second protective pipe 20 that would hinder the conduction of cables, etc. Furthermore, it becomes easier to manage the insertion amount of the first protective pipe 10 and the second protective pipe 20 into the joint 30 during construction.

[0021] (Seal ring) The joint 30 may have a first seal ring 61 positioned between the first member 31 and the first protective pipe 10, and a second seal ring 62 positioned between the second member 32 and the second protective pipe 20. The first seal ring 61 and the second seal ring 62 may be, for example, rubber rings. The first seal ring 61 and the second seal ring 62 may be positioned to fit into an annular groove formed in the first member 31 or the second member 32, respectively. This ensures a seal (watertight or airtight) between the joint 30 and the first protective pipe 10 and the second protective pipe 20. Furthermore, the first seal ring 61 and the second seal ring 62 may be arranged in a compressed state in the radial direction centered on the pipeline direction D. The elastic force of the compressed first seal ring 61 and the second seal ring 62 can create friction between the inner surface of the first member 31 and the outer surface of the first protective pipe 10, and between the inner surface of the second member 32 and the outer surface of the second protective pipe 20. Thus, the accidental detachment of the first protective pipe 10 or the second protective pipe 20 from the joint 30 can be suppressed.

[0022] As shown in Figure 1, the distance L3 from intersection X to the first seal ring 61 and the distance L4 from intersection X to the second seal ring 62 are preferably 40 mm or more and 250 mm or less. Distance L3 or distance L4 may be 50 mm or more and 250 mm or less. Therefore, the first protective pipe 10 and the second protective pipe 20 can be inserted into the joint 30 by an appropriate amount and overlapped without exceeding intersection X. This makes it possible to form a pipeline along a radius of curvature of about 5 m while ensuring the bonding strength by adhesion or the ability to follow displacement expected during an earthquake between the joint 30 and the first protective pipe 10 and the second protective pipe 20. In addition, the pipeline direction D can be bent without creating a step between the first end 11 of the first protective pipe 10 and the second end 21 of the second protective pipe 20 that would hinder the conduction of cables, etc. Therefore, a piping structure 1 can be provided in which the pipeline direction D is adjustable and cables, etc., can be easily inserted.

[0023] (action) As shown in Figure 3, the piping structure 1 is assembled by inserting the first protective pipe 10 and the second protective pipe 20 into the joint 30 to an appropriate length. At this time, the lengths of the connecting members (first protective pipe 10, second protective pipe 20, and joint 30), the order of the connecting members, the combination of connecting members, and the number of connecting members are set as appropriate according to the curvature and bending angle of the cables etc. that will be conducted through the piping structure 1.

[0024] As shown in Figure 1, the conduit (space along the conduit direction D) of the assembled piping structure 1 is straightened by aligning the first pipe axis D1 of the first protective pipe 10 and the second pipe axis D2 of the second protective pipe 20 on the same straight line. Then, as shown in Figure 3, the first pipe axis D1 of the first protective pipe 10 and the second pipe axis D2 of the second protective pipe 20 are intersected to bend the conduit direction D at a bending angle θ in order to form a conduit for passing cables, etc., that are bent at a predetermined curvature (for example, 5 m). As a result, the end of the first member 31 (first fitting portion 33) is locked to the restricting portion 40 formed on the second member 32, restricting further rotation. This eliminates the formation of steps in the conduit formed by the piping structure 1 that would be an obstacle when inserting cables, etc., making it easier to insert cables, etc.

[0025] (Second Embodiment) Next, the joint 30 and piping structure 1 according to the second embodiment will be described with reference to the drawings. In the description of the second embodiment, the same reference numerals may be used for characteristic parts that have a function common to the first embodiment. In the description of the second embodiment, the description of characteristic parts that have a function common to the first embodiment may be omitted. Figure 4 is an explanatory diagram showing the joint 30 according to the second embodiment in a state where the pipeline direction D is straight. Figure 5 is an explanatory diagram showing the joint 30 according to the second embodiment in a state where the pipeline direction D is bent. Figure 6 is a detailed explanatory diagram of part A in Figure 5. Figures 4 to 6 show cross-sections including the pipeline direction D (the first pipe axis D1 of the first protective pipe 10 and the second pipe axis D2 of the second protective pipe 20).

[0026] (Piping structure) As shown in Figures 4 and 5, the piping structure 1 according to the second embodiment includes a joint 30 comprising a first protective pipe 10 and a second protective pipe 20, similar to the piping structure 1 according to the first embodiment.

[0027] (joint shop) The joint 30 according to the second embodiment is a joint 30 that connects the first protective pipe 10 and the second protective pipe 20, similar to the joint 30 according to the first embodiment. The joint 30 includes a tubular first member 31 extending along the first pipe axis D1, having a first socket 31a at one end through which the first protective pipe 10 passes, and a first fitting portion 33 at the other end. The joint 30 also includes a tubular second member 32 extending along the second pipe axis D2, having a second socket 32a at one end through which the second protective pipe 20 passes, and a second fitting portion 34 at the other end. The first fitting portion 33 and the second fitting portion 34 are fitted together, and the first member 31 and the second member 32 are rotatable relative to each other at a predetermined bending angle θ around the intersection point X of the first pipe axis D1 and the second pipe axis D2. Here, the distance L1 from intersection X to the end of the first socket 31a, and the distance L2 from intersection X to the end of the second socket 32a are between 40 mm and 250 mm.

[0028] In this embodiment, the first fitting portion 33 extends in an annular shape along the circumferential direction centered on the first pipe axis D1 and has a ring-shaped projection 33P that protrudes toward the second member 32 along the first pipe axis D1. The second fitting portion 34 extends in an annular shape along the circumferential direction centered on the second pipe axis D2 and has an annular groove 34Q that is recessed in the direction away from the first member 31 along the second pipe axis D2. The ring-shaped projection 33P and the annular groove 34Q are fitted together. In this way, the joint 30 is rotatable at the first fitting portion 33 and the second fitting portion 34. This allows the joint 30 to change the bending angle θ between the first pipe axis D1 of the first member 31 and the second pipe axis D2 of the second member 32, thereby bending the pipeline direction D. In order to prevent water and sand from entering the joint 30 from the outside, it is preferable that a sealing member such as a rubber ring is placed between the inner and outer surfaces of the ring-shaped projection 33P and the surface of the annular groove 34Q, and recesses for placing a sealing member may be provided on the inner and outer surfaces of the second fitting portion 34 or on the surface of the annular groove 34Q of the second fitting portion 34.

[0029] (Regulatory Department) Preferably, the joint 30 has a restricting portion 40 that restricts the bending angle θ. Unlike the restricting portion 40 of the first embodiment, the restricting portion 40 of the second embodiment may be a projection that protrudes inward from the annular groove 34Q of the second member 32, as shown in Figure 6. The tip of the ring-shaped projection 33P of the first member 31 may have a corresponding constricted portion 33G between its head and base. As shown in Figure 4, when the first member 31 rotates relative to the second member 32 from a state where the pipeline direction D is straight, as shown in Figure 5, the ring-shaped projection 33P moves in a direction that causes it to disengage from the annular groove 34Q in a part of the circumferential direction. Then, as shown in Figure 6, the constricted portion 33G formed on the ring-shaped projection 33P is locked into the restricting portion 40 formed on the annular groove 34Q. Here, the formation of the restricting portion 40 and the constricted portion 33G increases the resistance to the force that would cause it to disengage further. As a result, the restricting portion 40 restricts further relative rotation between the first member 31 and the second member 32. Thus, the joint 30 has a restricting portion 40 that restricts the bending angle θ. This prevents the joint 30 from bending at an angle so large that a step is created between the first end 11 of the first protective pipe 10 and the second end 21 of the second protective pipe 20 that would hinder the insertion of cables or the like.

[0030] As described above, the joint 30 according to the embodiment connects the first protective pipe 10 and the second protective pipe 20. The joint 30 includes a tubular first member 31 extending along the first pipe axis D1, having a first socket 31a at one end through which the first protective pipe 10 passes, and a first fitting portion 33 at the other end. The joint 30 also includes a tubular second member 32 extending along the second pipe axis D2, having a second socket 32a at one end through which the second protective pipe 20 passes, and a second fitting portion 34 at the other end. The first fitting portion 33 and the second fitting portion 34 are fitted together, and the first member 31 and the second member 32 are rotatable relative to each other at a predetermined bending angle θ around the intersection X of the first pipe axis D1 and the second pipe axis D2. The distance L1 from intersection X to the end of the first socket 31a, and the distance L2 from intersection X to the end of the second socket 32a, are between 40 mm and 250 mm. This allows for the formation of a conduit along a radius of curvature of approximately 5 m while ensuring bonding strength between the joint 30 and the first protective pipe 10 and the second protective pipe 20, or the ability to follow displacements expected during an earthquake. Furthermore, the conduit direction D can be bent without creating a step between the first end 11 of the first protective pipe 10 and the second end 21 of the second protective pipe 20 that would hinder the conduction of cables, etc. Thus, a piping structure 1 is provided that allows for adjustable conduit direction D and easy insertion of cables, etc.

[0031] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

[0032] Furthermore, it is possible to replace the components in the above embodiments with well-known components as appropriate, without departing from the spirit of the present invention. Also, the above modifications may be combined as appropriate, without departing from the spirit of the present invention. [Explanation of Symbols]

[0033] 1 Piping structure 10 1st protection tube 11 First end 20 2nd protection tube 21 Second end 30 fittings 31 First Member 31a 1st socket 32 Second Member 32a 2nd socket 33 First mating section 33G Waist area 33m 1st sphere 33P Ring-shaped protrusion 34 Second mating section 34f 2nd sphere 34Q Ring groove 40 Regulatory Department 50 Stoppers 51 First Stopper 52 Second Stopper 61 First seal ring 62. Second seal ring D Pipe direction D1 1st tube shaft D2 2nd tube shaft L1,L2,L3,L4 distance X intersection θ bending angle

Claims

1. A joint connecting the first protective tube and the second protective tube, A tubular first member extending along the first pipe axis, having a first receiving opening at one end through which the first protective tube passes, and a first fitting portion at the other end, A tubular second member extending along the second pipe axis has a second receiving opening at one end through which the second protective tube passes, and a second fitting portion at the other end, The first fitting portion and the second fitting portion are fitted together. The first member and the second member are rotatable relative to each other at a predetermined bending angle about the intersection of the first pipe axis and the second pipe axis. The distance from the intersection to the end of the first socket, and the distance from the intersection to the end of the second socket, are 40 mm or more and 250 mm or less. The first fitting portion extends in an annular shape along the circumferential direction centered on the first pipe axis and has a ring-shaped projection that protrudes toward the second member along the first pipe axis. The second fitting portion extends in an annular shape along the circumferential direction centered on the second pipe axis and has an annular groove that is recessed in a direction away from the first member along the second pipe axis. A joint in which the ring-shaped projection and the annular groove engage with each other.

2. The joint according to claim 1, further comprising a restricting portion for restricting the bending angle.

3. The first fitting portion has a first spherical surface on its outer circumferential surface, The second fitting portion has a second spherical surface on its inner circumferential surface, The joint according to claim 1 or claim 2, wherein the first spherical surface and the second spherical surface are in slidable contact.

4. The joint according to claim 1 or claim 3, wherein the distance from the intersection to the end of the first socket and the distance from the intersection to the end of the second socket are the same.

5. The joint is equipped with a stopper that restricts the relative movement of the first protective pipe and the second protective pipe toward the intersection point, The joint according to claim 1 or claim 4, wherein the stopper comprises a first stopper positioned on the first socket side of the intersection and at a distance of 40 mm or more from the end of the first socket, and a second stopper positioned on the second socket side of the intersection and at a distance of 40 mm or more from the end of the second socket.

6. The joint according to any one of claims 1 to 5, further comprising a first seal ring disposed between the first member and the first protective tube, and a second seal ring disposed between the second member and the second protective tube.

7. The joint according to claim 6, wherein the distance from the intersection to the first seal ring and the distance from the intersection to the second seal ring are 40 mm or more and 250 mm or less.

8. The device comprises the first protective tube and the second protective tube, The other end of the first protective tube is positioned on the first socket side of the intersection, The other end of the second protective pipe is positioned on the second socket side of the intersection, the piping structure including the fitting according to any one of claims 1 to 7.

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