Method for assembling telescopic pipe joint and temporary fixing structure of locking ring

Abstract

Provided is a method for assembling a telescopic pipe joint (10) in which a pipe body (1) and a pipe body (2) inserted therein are connected so as to be capable of moving relative to each other within a certain range in the axial direction, and the function of preventing detachment is performed by a lock ring (4) attached to the outer peripheral surface of the pipe body (2), the method comprising: a temporary fixing step in which an assembly (48) is fitted into the pipe body (1), and the assembly (48) is fixed to the pipe body (1); an assembly (48) which is formed by assembling the locking ring (4), the diameter of which is expanded by elastic deformation, on the temporary fixing jig (8), and which holds the locking ring (4) in the expanded state in a state of being concentric with the pipe body (1); and an attachment step in which the pipe body (2) is inserted into the lock ring (4) in the expanded-diameter state, and the temporary fixing jig (8) is removed from the lock ring (4) by the insertion and movement of the pipe body (2), thereby attaching the lock ring (4) to the outer peripheral surface of the pipe body (2).

Description

Technical Field The present disclosure relates to an assembling method of a telescopic pipe joint and a temporary fixing structure of a locking ring used in the method. Background Art Patent documents 1 and 2 respectively describe a telescopic pipe joint with a telescopic function. According to the telescopic pipe joint, a first pipe body and a second pipe body inserted therein are connected so as to be relatively movable within a certain range along the axial direction. A locking ring (annular member) extending in the circumferential direction is installed on the outer peripheral surface of the second pipe body. When the second pipe body attempts to move relative to the first pipe body beyond a certain range in the direction of separation, the locking ring will engage with the engaged portion formed inside the first pipe body, thereby limiting the relative movement and preventing separation. In order to be able to exert the above-mentioned anti-separation function, the outer diameter of the locking ring is set to be larger than the inner diameter of the engaged portion. Therefore, as shown in Patent Documents 1 and 2, the operation of installing the locking ring on the outer circumferential surface of the second tube body is performed in a state where it is set inside the first tube body. Patent Document 1 proposes a method of rotating the locking ring using a tool, and screwing the internal thread formed on the inner circumferential surface of the locking ring onto the external thread formed on the outer circumferential surface of the second tube body. Patent Document 2 also proposes a method of expanding the diameter of the locking ring using a tool, and embedding the expanded locking ring on the second tube body. In the above methods described in Patent Documents 1 and 2, a relatively complicated operation is required: inserting a tool from the opening on the opposite side of the opening for inserting the second tube into the pair of openings formed at both ends of the first tube body, and operating the tool to rotate or expand the locking ring. Furthermore, if the opening for inserting the tool is located at a socket extending in the axial direction (for example, referring to Figure 1 ) end, and / or the tube body is of small diameter (e.g., a nominal diameter of less than 100), it is necessary to pass a tool through a narrow space to operate the locking ring, and therefore, it is difficult to process using existing tools. Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 2-271192 Patent Document 2: Japanese Patent Application Laid-Open No. 10-54487 Summary of the invention Problem that the invention aims to solve The present disclosure is made in view of the above situation, and an object of the present disclosure is to provide an assembly method of a telescopic pipe joint and a temporary fixing structure of a lock ring, which can improve the installation operability of the lock ring. Solutions for solving problems

[0001] The present disclosure provides an assembly method for a telescopic pipe joint, in which a first pipe body and a second pipe body inserted therein are connected so as to be relatively movably connected within a certain range along an axial core direction, and a locking ring installed on the outer peripheral surface of the second pipe body plays a role in preventing separation. The assembly method for the telescopic pipe joint comprises: a temporary fixing process, in which an assembly body is embedded in the first pipe body, the assembly body is formed by assembling the locking ring, which is expanded in diameter by elastic deformation, on a temporary fixing fixture, and the locking ring in the expanded diameter state is maintained in a posture coaxial with the first pipe body; and an installation process, in which the second pipe body is inserted into the locking ring in the expanded diameter state, the temporary fixing fixture is removed from the locking ring by the insertion and movement of the second pipe body, and the locking ring is installed on the outer peripheral surface of the second pipe body. According to this method, the locking ring in the expanded state is temporarily fixed in a coaxial posture with the first tube body inside the first tube body, and the second tube body is inserted into the locking ring in the expanded state, so that the locking ring is installed on the outer peripheral surface of the second tube body. Therefore, it is not necessary to insert a tool from the opening on the opposite side of the opening for inserting the second tube body in a pair of openings formed at both ends of the first tube body to operate the locking ring, which can improve the installation operability of the locking ring.

[0002] In the above-mentioned expansion joint assembly method [1], the lock ring has a split portion that splits the lock ring in the circumferential direction, and the temporary fixing jig has: a main body formed to be embedded in the first tube body; and a first protrusion protruding from the main body. In the temporary fixing step, the first protrusion is preferably inserted into the split portion whose gap is enlarged by elastic deformation, so that the lock ring is maintained in an expanded state. According to this method, the lock ring in the expanded state can be maintained in a predetermined posture using a temporary fixing jig with a simple structure.

[0003] In the assembly method of the expansion joint of the above [1] or [2], the temporary fixing jig has: a main body formed to be embedded in the first tube body; and a second protrusion protruding from the main body. In the temporary fixing process, the locking ring is preferably mounted on the temporary fixing jig in a state of being abutted against the second protrusion. By abutting the locking ring against the second protrusion, it can be used for positioning when the locking ring is assembled on the temporary fixing jig. In addition, since the relative position of the locking ring assembled on the temporary fixing jig is relatively stable, the operability is improved.

[0004] In any of the above expansion joint assembly methods [1] to [3], in the installation step, the locking ring is preferably engaged with the engaged portion formed inside the first tube body in the insertion direction of the second tube body, and in the engaged state, the temporary fixing jig is pressed by the second tube body to be removed from the locking ring. According to this method, the temporary fixing jig can be smoothly removed from the locking ring by inserting and moving the second tube body, thereby improving operability.

[0005] In any of the telescopic pipe joint assembly methods of [1] to [4] above, the first pipe body includes: an outer shell including a spherical inner peripheral surface; and an intermediate sleeve including a spherical outer peripheral surface, the spherical outer peripheral surface and the spherical inner peripheral surface can be relatively freely slidably engaged, and in the temporary fixing process, the assembly can be embedded in the intermediate sleeve. In this case, when assembling a telescopic pipe joint having both telescopic and bending functions (telescopic flexible pipe joint), the installation operability of the locking ring can be improved. In addition, before the intermediate sleeve is engaged with the outer shell, the assembly can be pre-embedded in the intermediate sleeve, which can improve operability.

[0006] In the above-mentioned expansion joint assembly method of [5], a notch is formed in the intermediate sleeve, and the notch allows the locking ring to pass through in a posture where the axial direction and radial direction of the intermediate sleeve are consistent. In the temporary fixing step, the temporary fixing jig is preferably embedded in the notch. According to this method, the assembly body can be embedded in the intermediate sleeve by using the notch formed in the intermediate sleeve.

[0007] The temporary fixing structure of the locking ring disclosed in the present invention is used for assembling a telescopic pipe joint, in which a first tube body and a second tube body inserted therein are connected so as to be relatively movably connected within a certain range along the axial core direction, and a locking ring installed on the outer peripheral surface of the second tube body plays a role in preventing separation. The temporary fixing structure of the locking ring is configured as follows: an assembly body is embedded in the first tube body, and the assembly body is formed by assembling the locking ring, which is expanded in diameter by elastic deformation, on a temporary fixing fixture. The locking ring in the expanded state is maintained in a posture coaxial with the first tube body. When the second tube body is inserted into the locking ring in the expanded state, the insertion and movement of the second tube body causes the temporary fixing fixture to be removed from the locking ring, thereby allowing the locking ring to be installed on the outer peripheral surface of the second tube body. According to such a structure, the locking ring in the expanded state is temporarily fixed in a coaxial posture with the first tube body inside the first tube body, and the second tube body is inserted into the locking ring in the expanded state, so that the locking ring is installed on the outer peripheral surface of the second tube body. Therefore, it is not necessary to insert a tool from the opening on the opposite side of the opening for inserting the second tube body in a pair of openings formed at both ends of the first tube body to operate the locking ring, and the installation operability of the locking ring can be improved.

[0008] In the temporary fixing structure of the locking ring of the above-mentioned [7], the locking ring has a dividing portion that divides the locking ring in the circumferential direction, and the temporary fixing fixture has: a main body formed to be embedded in the first tube body; and a first protrusion protruding from the main body, and the first protrusion is preferably inserted into the dividing portion whose gap is enlarged by elastic deformation, so that the locking ring is maintained in an expanded diameter state. According to such a structure, the locking ring in the expanded diameter state can be maintained in a predetermined posture using a temporary fixing fixture with a simple structure.

[0009] In the temporary fixing structure of the locking ring of [7] or [8] above, the temporary fixing fixture comprises: a main body formed to be embedded in the first tube; and a second protrusion protruding from the main body, and the locking ring is preferably mounted on the temporary fixing fixture in a state of being abutted against the second protrusion. By abutting the locking ring against the second protrusion, it can be used for positioning when the locking ring is mounted on the temporary fixing fixture. In addition, since the relative position of the locking ring mounted on the temporary fixing fixture is relatively stable, the operability is improved.

[0010] In any of the temporary fixing structures of the locking ring described in [7] to [9] above, a clamped portion is preferably formed inside the first tube, and the locking ring in the expanded diameter state is opposite to the clamped portion in the insertion direction of the second tube. According to such a structure, the temporary fixing fixture can be smoothly removed from the locking ring by inserting and moving the second tube, thereby improving operability.

[0011] In any of the temporary fixing structures of the locking ring described in [7] to

[10] above, the first tube body includes: an outer shell including a spherical inner peripheral surface; and an intermediate sleeve including a spherical outer peripheral surface, wherein the spherical outer peripheral surface and the spherical inner peripheral surface can be relatively freely slidably engaged, and the assembly can be embedded in the intermediate sleeve. In this case, when assembling a telescopic pipe joint (telescopic flexible pipe joint) having both telescopic and bending functions, the installation operability of the locking ring can be improved. In addition, before the intermediate sleeve is engaged with the outer shell, the assembly can be pre-embedded in the intermediate sleeve, which can improve operability.

[0012] In the temporary fixing structure of the locking ring of the above-mentioned

[11] , a cutout is formed in the intermediate sleeve, the cutout allows the locking ring to pass through in a posture where the axial direction and radial direction of the intermediate sleeve are consistent, and the temporary fixing jig is preferably embedded in the cutout. According to such a structure, the assembly can be embedded in the intermediate sleeve by utilizing the cutout formed in the intermediate sleeve. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing an example of the structure of a telescopic pipe joint; Figure 2 (A) front view and (B) AA arrow cross-sectional view of the locking ring in a natural state; Figure 3 A diagram for explaining a problem when assembling an expansion joint in a conventional method; Figure 4 A cross-sectional view for explaining the temporary fixing process; Figure 5 A cross-sectional view for explaining the installation process; Figure 6 A cross-sectional view showing the operation of embedding the assembly in the intermediate casing; Figure 7 (A) rear view and (B) BB arrow cross-sectional view of the intermediate casing; Figure 8 (A) front view and (B) side view of the temporary fixing fixture; Fig. 9 It is the front view of the assembly; Fig.10 A front view showing a modified example of the temporary fixing jig; Fig.11 for Fig.10 (A) exploded front view and (B) exploded side view of the main body shown; Fig.12 A cross-sectional view showing other embodiments of the telescopic pipe joint; Fig.13 A cross-sectional view showing other embodiments of the telescopic pipe joint; Fig.14 It is a longitudinal cross-sectional view of the expansion joint in a normal state; Fig.15 is a longitudinal cross-sectional view of the expansion joint in the minimum contraction state; Fig.16 is a longitudinal cross-sectional view of the expansion joint in the maximum extension state; Fig.17 (A) is a longitudinal cross-sectional view of the second sleeve; (B) is Fig.17 (A) is an arrow view at line BB; (C) is a diagram showing a third locking ring; Fig.18 Middle (A) Fig.17 (B) is a transverse cross-sectional view at the V(A)-V(A) line; (B) is Fig.17 (B) is a transverse cross-sectional view at the line V(B)-V(B); Fig.19 A perspective view showing the fitting groove portion and the insertion groove portion of the seal setting portion; Fig. 20 (A) is a diagram showing the operation of the insertion process in the first process; (B) is a diagram showing the operation of the posture change process in the first process; Fig.21 (A) is a diagram showing the operation of the third process; (B) is a diagram showing the third locking ring and the installation tool; Fig. 22 (A) is a diagram showing the operation of the locking ring insertion process in the fourth process; (B) is a diagram showing the operation of the inner joint body installation process in the fourth process; Fig.23 (A) is a diagram showing the operation of the sleeve inserting process in the fourth process; (B) is a diagram showing the operation of the locking ring installing process in the fourth process; Fig.24 (A) is a diagram showing a state in which the second connection step in the fourth step is being performed; (B) is a diagram showing a state in which the first connection step in the fourth step is being performed. DETAILED DESCRIPTION Embodiments of an assembly method of a telescopic pipe joint and a temporary fixing structure of a lock ring according to the present disclosure will be described. [Construction of expansion joint] Reference Figure 1 , 2 The structure of the expansion pipe joint will be described. Figure 1 The telescopic pipe joint 10 shown comprises: a pipe body 1 (first pipe body); a pipe body 2 (second pipe body) inserted therein; and an annular sealing gasket 3 sealed between the two. The pipe body 1 and the pipe body 2 are arranged along the axial direction ( Figure 1 The pipe bodies 1 and 2 are connected so as to be relatively movable within a certain range (in the left and right directions). In this embodiment, an example is shown in which the pipe body 1 and the pipe body 2 are cast iron pipes with a nominal diameter of 75 and are used as water pipes. However, the pipe bodies 1 and 2 may also be fluid pipes for liquids other than water, gases, or gas-liquid mixtures. In addition, the specifications such as the pipe size may be appropriately changed according to the conditions of use. The tube body 1 has a pair of openings 1a and 1b formed at both ends of the tube body 1. The opening 1a is formed at the end of the entrance of the tube body 1. The opening 1b is formed at the end of the insertion opening of the tube body 1 extending in the axial direction. The tube body 2 is inserted into the tube body 1 through the opening 1a. The opening 1a includes an opening 6a of the intermediate sleeve 6 described later (see Figure 6 , 7 ). Insertion direction D1 is the direction in which tube 2 is inserted into tube 1, which is equivalent to Figure 1 The detachment direction D2 is the direction in which the tube body 2 detaches from the tube body 1, which is equivalent to Figure 1 In addition, the figure observed along the insertion direction D1 is regarded as a front view, and the figure observed along the removal direction D2 is regarded as a rear view. A locking ring 4 is installed on the outer peripheral surface of the tube body 2. The locking ring 4 extends in a circumferential direction centered on the shaft core. The locking ring 4 is formed of a metal such as steel. An annular groove 25 for installing the locking ring 4 is formed on the outer peripheral surface of the tube body 2. The locking ring 4 is fixed to the tube body 2 by being embedded in the annular groove 25. The annular groove 25 is formed at a position away from the front end of the tube body 2 in the disengagement direction D2. Since the depth of the annular groove 25 is less than the thickness of the locking ring 4, the locking ring 4 can be installed and fixed in a state of protruding from the annular groove 25. like Figure 2 As shown, the locking ring 4 has a dividing portion 45 that divides the locking ring 4 in the circumferential direction. In the present embodiment, the locking ring 4 is formed by a C-shaped ring member, and the dividing portion 45 is provided at one place in the circumferential direction. The inner diameter of the locking ring 4 in a natural state without external force applied is smaller than the outer diameter of the tube body 2. Therefore, when the locking ring 4 is externally embedded on the tube body 2, the gap between the dividing portions 45 will increase due to elastic deformation, thereby expanding the diameter of the locking ring 4. Insertion holes 46 are respectively provided at a pair of end portions separated by the dividing portion 45. A tool 34 (see Figure 6 (B) in the figure. The inner circumferential surface of the locking ring 4 is provided with a cutout 43 so that the locking ring 4 can expand smoothly through elastic deformation. The cutout 43 is formed by partially reducing the thickness of the locking ring 4. The cutout 43 extends in the circumferential direction within a predetermined angle range, and the two ends of its inner surface are curved in an arc shape. The cutout 43 is formed at multiple locations (three locations in this embodiment) in the circumferential direction. The smaller the diameter size of the locking ring 4, the greater the force required to expand the diameter of the locking ring 4. Therefore, when the pipe body 2 is of small diameter (for example, the nominal diameter is less than 100), the shape of the locking ring 4 with such a cutout 43 is particularly useful. The locking ring 4 installed on the outer circumference of the tube body 2 has a function of preventing the telescopic pipe joint 10 from disengaging. When the tube body 2 attempts to move relative to the direction of disengagement from the tube body 1 beyond a certain range, the locking ring 4 will engage with the engaged portion 17 formed inside the tube body 1, thereby limiting the relative movement and preventing disengagement. The engaged portion 17 is formed by an annular wall portion, and the mounting groove 18 on which the sealing gasket 3 is installed is divided by the annular wall portion, and the engaged portion 17 protrudes toward the inner circumference. The inner diameter of the engaged portion 17 (annular wall portion) is larger than the outer diameter of the tube body 2, and smaller than the outer diameter of the locking ring 4 installed on the outer circumference of the tube body 2. In this embodiment, the telescopic pipe joint 10 is shown as an example of a telescopic pipe joint (telescopic flexible pipe joint) having both telescopic and bending functions. The pipe body 1 includes: an outer shell 5 including a spherical inner peripheral surface; an intermediate sleeve 6 including a spherical outer peripheral surface, the spherical outer peripheral surface and the spherical inner peripheral surface can be relatively freely slidably engaged; and an annular sealing gasket 7 sealed between the two. The telescopic pipe joint 10 is freely telescopic by sliding between the intermediate sleeve 6 and the pipe body 2, and is freely bendable by sliding between the outer shell 5 and the intermediate sleeve 6. However, as shown in the modified examples below, the telescopic pipe joints to which the present disclosure is applicable are not limited to telescopic pipe joints with bending functions. The operation of installing the locking ring 4 on the outer peripheral surface of the tube body 2 needs to be performed in a state where the locking ring 4 and the portion of the tube body 2 where the locking ring 4 is installed are both located inside the tube body 1. However, according to the method described in Patent Document 2, Figure 3 As shown in FIG. 1 , the tool 35 must be inserted from the opening 1b to operate the locking ring 4, which is very cumbersome. In particular, when the opening 1b is formed at the end of the socket, or the pipe body 1 has a small diameter, it is very difficult to insert the tool 35 through a narrow space to operate the locking ring 4. Therefore, in the present embodiment, the telescopic pipe joint 10 is assembled according to the method described below to facilitate the installation of the locking ring 4. [How to assemble the expansion joint] Reference Figures 4 to 9 , the assembly method of the expansion joint 10 is described. The assembly method of the expansion joint 10 of this embodiment includes: a temporary fixing step, in which the assembly 48 is embedded in the pipe body 1, and the assembly 48 is formed by assembling the locking ring 4 that has been expanded by elastic deformation on the temporary fixing fixture 8, and the locking ring 4 in the expanded state is maintained in a posture coaxial with the pipe body 1 (refer to Figure 4 ); and an installation step, in which the locking ring 4 is inserted into the tube body 2 in the expanded state, and the temporary fixing fixture 8 is removed from the locking ring 4 by inserting and moving the tube body 2, thereby installing the locking ring 4 on the outer peripheral surface of the tube body 2 (reference Figure 5 ). According to this method, Figure 4As shown in FIG. 1 , the locking ring 4 in the expanded state is temporarily fixed in a coaxial posture with the tube body 1. Then, as shown in FIG. Figure 5 As shown, by inserting the locking ring 4 in the expanded state into the pipe body 2, the locking ring 4 is installed on the outer peripheral surface of the pipe body 2. Therefore, it is not necessary to insert a tool from the opening 1b of the pipe body 1 to operate the locking ring 4. Therefore, whether the opening 1b is formed at the end of the socket or the pipe body 1 is small in diameter, the above-mentioned undesirable situation will not occur. Therefore, the installation operability of the locking ring 4 can be improved. When the pipe body 1 is small in diameter (for example, the nominal diameter is less than 100), such an improvement effect is particularly significant. In this assembly method, a temporary fixing jig 8 is used to temporarily fix the locking ring 4 after the diameter expansion. The temporary fixing jig 8 can be embedded in the tube body 1. In addition, when embedded in the tube body 1, the temporary fixing jig 8 can keep the locking ring 4 after the diameter expansion in a posture coaxial with the tube body 1. Here, "embedded" means embedded in the inner side of the corresponding component (the tube body 1 in this embodiment), and a gap can be left between them. Figure 5 As shown in (B) in FIG. 1 , during the installation process, the temporary fixing jig 8 is removed from the lock ring 4 and then recovered. In this embodiment, the pipe body 1 includes an outer shell 5 and an intermediate sleeve 6. Figure 4 As shown, the assembly 48 is embedded in the middle sleeve 6 of the pipe body 1. Figure 6 As shown, before the intermediate sleeve 6 is fitted with the housing 5, the assembly 48 can be pre-embedded in the intermediate sleeve 6. In this way, by inserting the intermediate sleeve 6 (refer to Figure 6 (C)) is engaged with the housing 5, as shown Figure 4 As shown, the pipe body 1 in which the assembly 48 is embedded can be obtained. According to this method, compared with the case where the assembly 48 is embedded in the intermediate sleeve 6 after being fitted with the outer shell 5, the workability is better. To embed the assembly 48 in the intermediate sleeve 6, first, Figure 6 In (A), the lock ring 4 is provided inside the intermediate sleeve 6. The lock ring 4 is provided in the annular circumferential groove 13, which is formed on the insertion direction D1 side of the engaged portion 17. The inner diameter of the annular circumferential groove 13 is set larger than the outer diameter of the lock ring 4. As described above, since the inner diameter of the engaged portion 17 is smaller than the outer diameter of the lock ring 4, the lock ring 4 is inserted into the intermediate sleeve 6 from the opening 6b located on the insertion direction D1 side of a pair of openings 6a and 6b formed at both ends of the intermediate sleeve 6. like Figure 7 As shown, a cutout portion 65 is provided at the opening 6b of the intermediate sleeve 6, and the cutout portion 65 partially increases the diameter of the opening 6b. The diameter size D65 of the cutout portion 65 is set to be greater than or equal to the outer diameter D4 of the locking ring 4 (refer to Figure 2). Therefore, a cutout portion 65 is formed in the intermediate sleeve 6, and the cutout portion 65 allows the locking ring 4 (see Figure 7 The dotted line in (A) in the figure passes through the intermediate sleeve 6 in a posture where the axial direction and radial direction are consistent. After the lock ring 4 passes through the cutout portion 65 and is set inside the intermediate sleeve 6, the lock ring 4 is rotated in the annular groove 13, as shown in FIG. Figure 6 As shown in (A) in FIG. 1 , the lock ring 4 can be changed to a posture coaxial with the intermediate sleeve 6 . Then, if Figure 6 As shown in (B) in FIG. 1 , a temporary fixing fixture 8 is installed in the intermediate sleeve 6. In this embodiment, the temporary fixing fixture 8 is installed at a position closer to the insertion direction D1 side than the annular circumferential groove 13, and more specifically, is installed at the opening 6b on the insertion direction D1 side of the intermediate sleeve 6. Figure 8 As shown, the temporary fixing jig 8 has a main body 80 formed to be embedded in the intermediate sleeve 6 (and further in the tube body 1). The main body 80 is formed in a plate shape, but is not limited to this. The main body 80 has a shape that can be embedded in the cutout portion 65 (refer to Figure 7 Thereby, the temporary fixing jig 8 can be prevented from moving around the axis. In the present embodiment, the temporary fixing jig 8 has a protrusion 81 (first protrusion) protruding from the main body 80. In addition, the temporary fixing jig 8 also has a protrusion 82 (second protrusion) protruding from the main body 80. The protrusions 81 and 82 protrude toward the disengagement direction D2, respectively, and are arranged at radial positions that can be opposite to the locking ring 4 assembled on the temporary fixing jig 8. The protrusions 81 and 82 are both formed into a circular arc shape extending in the circumferential direction, but are not limited to this. In addition, the temporary fixing jig 8 is formed of a resin such as Duracon, but is not limited to this. Then, if Figure 6 As shown in (B) and (C) in FIG. 1 , the locking ring 4, which is enlarged by elastic deformation, is assembled on the temporary fixing fixture 8, and the assembly 48 is embedded in the intermediate sleeve 6. The locking ring 4 is assembled adjacent to the side of the temporary fixing fixture 8 in the direction of separation D2. The locking ring 4 can be enlarged by using a tool 34. The tool 34 can be an existing tool such as a snap ring pliers, and its front end is inserted into the insertion hole 46 (refer to FIG. Figure 2 The diameter expansion operation of the locking ring 4 using such a tool 34 does not need to be performed through the opening 1b of the tube body 1, so it does not lead to a decrease in operability. In the temporary fixing process, Fig. 9As shown, the protrusion 81 is inserted into the dividing portion 45 whose gap is enlarged by elastic deformation so that the locking ring 4 is kept in an expanded state. In this way, the locking ring 4 in the expanded state can be kept in a predetermined posture using the temporary fixing jig 8 with a simple structure. In addition, it is only necessary to make the expanded locking ring 4 adjacent to the temporary fixing jig 8, so the operability is excellent. The locking ring 4 is kept in a state where its inner diameter is expanded to be larger than the outer diameter of the tube body 2. The width W81 of the protrusion 81 is greater than or equal to the gap of the dividing portion 45, which is necessary to ensure the inner diameter of the locking ring 4 as described above. In this embodiment, in the temporary fixing process, as Fig. 9 As shown, the locking ring 4 is assembled on the temporary fixing jig 8 in a state of being in contact with the protrusion 82. By abutting the locking ring 4 on the protrusion 82, it can be used for positioning when the locking ring 4 is assembled on the temporary fixing jig 8. In addition, since the relative position of the locking ring 4 assembled on the temporary fixing jig 8 is relatively stable, the operability is good. Here, the "abutting state" refers to a state of being in close contact with the corresponding component (the protrusion 82 in this embodiment), or a state of being basically in close contact with a small gap. In this embodiment, the inner circumference of the lock ring 4, that is, the portion opposite to the dividing portion 45 across the center of the lock ring 4, abuts against the protrusion 82. When the lock ring 4 in the expanded diameter state supported by the tool 34 is assembled on the temporary fixing jig 8 (refer to Figure 6 In (B)), by abutting the portion against the protrusion 82, the initial position of the locking ring 4 relative to the temporary fixing jig 8 can be determined, making the operability better. In addition, in this example, the radially recessed cutout 43 also abuts against the protrusion 82, thereby preventing the locking ring 4 from being displaced circumferentially relative to the temporary fixing jig 8. like Figure 6 As shown in (C) in the figure, after the assembly 48 is embedded in the intermediate sleeve 6, the intermediate sleeve 6 is fitted into the housing 5 equipped with the sealing gasket 7. A cutout portion is formed at the opening on the side of the housing 5 in the direction of separation D2, which is not shown, and allows the intermediate sleeve 6 to pass through in a posture where the axial direction and radial direction of the housing 5 are consistent. After the intermediate sleeve 6 passes through the cutout portion and is set inside the housing 5, as shown in FIG. Figure 4 As shown, by rotating the intermediate sleeve 6, it can be changed into a coaxial posture with the housing 5. Lubricant can be applied between the inner peripheral surface of the sealing gasket 7 and the outer peripheral surface of the intermediate sleeve 6, so that the intermediate sleeve 6 can be rotated smoothly. By fitting the intermediate sleeve 6 with the housing 5 as described above and installing the sealing gasket 3 in the intermediate sleeve 6, as shown in FIG. Figure 4As shown, the pipe body 1 with the assembly 48 embedded therein can be obtained. The sealing gasket 3 can also be installed in the intermediate sleeve 6 before being fitted with the housing 5. After the pipe body 2 is inserted into the locking ring 4 in the expanded state, the temporary fixing fixture 8 in the assembly 48 embedded in the pipe body 1 is in a position where it can interfere with the pipe body 2. In this embodiment, as shown in FIG. Fig. 9 As shown, in the assembly 48 viewed from the insertion direction D1 , (the main body 80 of) the temporary fixing jig 8 is disposed so as to penetrate the locking ring 4 longitudinally or transversely. like Figure 4 or Figure 7 As shown, a clamped portion 14 is formed inside the tube body 1, and the locking ring 4 in the expanded state is opposite to the clamped portion 14 in the insertion direction D1 of the tube body 2. The clamped portion 14 is formed by an annular wall portion that forms an opening (opening 6b of the intermediate sleeve 6) for installing the temporary fixing fixture 8, and protrudes toward the inner peripheral side. An allowable space 15 for the locking ring 4 in the expanded state can be formed adjacent to the side of the disengagement direction D2 of the clamped portion 14 (annular wall portion). The diameter dimension D15 of the allowable space 15 is set to be larger than the diameter dimension D65 of the cutout portion 65, and is greater than or equal to the outer diameter of the locking ring 4 in the expanded state. After the locking ring 4 is temporarily fixed by the temporary fixing process, Figure 5 As shown, the tube body 2 is inserted into the tube body 1. Inside the tube body 1, since the locking ring 4 in the expanded state is maintained in a coaxial posture with the tube body 1, the tube body 2 inserted into the tube body 1 is automatically inserted into the locking ring 4. The axis of the locking ring 4 temporarily fixed inside the tube body 1 does not need to be completely consistent with the axis of the tube body 1, as long as the degree of insertion of the tube body 2 into the locking ring 4 is basically consistent after the tube body 2 is inserted into the tube body 1. In this embodiment, during the installation process, the locking ring 4 is engaged with the engaged portion 14 formed inside the tube body 1 in the insertion direction D1 of the tube body 2. In the engaged state, the temporary fixing fixture 8 is pressed by the tube body 2 to remove it from the locking ring 4. As a result, the temporary fixing fixture 8 can be smoothly removed from the locking ring 4 by inserting and moving the tube body 2, thereby improving operability. After the temporary fixing fixture 8 is removed, the locking ring 4 is reduced in diameter due to the recovery of elastic deformation, and is thus installed on the outer peripheral surface of the tube body 2. Confirm that the locking ring 4 has been embedded in the annular groove 25, and the temporary fixing fixture 8 is recovered, and the locking ring 4 is obtained. Figure 1 The telescopic pipe joint 10 is shown. [Temporary fixing structure of the locking ring] Since the temporary fixing structure of the locking ring 4 has been shown in the description of the assembly method, only a brief description thereof will be given here. Figure 4As shown, in the temporary fixing structure of this embodiment, the assembly 48 is embedded in the tube body 1, and the assembly 48 is formed by assembling the locking ring 4 that has been expanded by elastic deformation on the temporary fixing fixture 8, and the locking ring 4 in the expanded state is maintained in a posture coaxial with the tube body 1. Figure 5 As shown, when the locking ring 4 in the expanded state is inserted into the pipe body 2 , the insertion and movement of the pipe body 2 causes the temporary fixing fixture 8 to be removed from the locking ring 4 , so that the locking ring 4 is installed on the outer peripheral surface of the pipe body 2 . like Figure 4 and Fig. 9 As shown, the temporary fixing structure of this embodiment inserts the protrusion 81 into the dividing portion 45 whose gap is enlarged by elastic deformation so that the locking ring 4 is kept in an expanded state. In addition, the locking ring 4 is assembled on the temporary fixing jig 8 in a state of being close to the protrusion 82. The inside of the tube body 1 is formed with a clamped portion 14, and the locking ring 4 in the expanded state is opposite to the clamped portion 14 in the insertion direction D1 of the tube body 2. Therefore, the locking ring 4 is clamped with the clamped portion 14 in the insertion direction D1 of the tube body 2, and in the clamped state, the temporary fixing jig 8 can be pressed by the tube body 2 to be removed from the locking ring 4. [Other embodiments] Reference Fig.10 , 11 A modified example of the temporary fixing jig is described. In addition to the configuration described below, Fig.10 The temporary fixing fixture 9 shown can be constructed in the same manner as the temporary fixing fixture 8 described above, so the common points will not be described here, and the differences will be mainly introduced. The temporary fixing fixture 9 includes a main body 90 that can be embedded in the tube body 1 and a protrusion 91 and a protrusion 92 protruding from the main body 90. These have the same functions as the main body 80, the protrusion 81 and the protrusion 82 included in the temporary fixing fixture 8. The temporary fixing fixture 9 is formed of metal such as steel, but it is not limited to this. When the pipe body 1 (the intermediate sleeve 6) is formed by casting, the difference in the inner diameter and other dimensions is often large, so there is a risk that the temporary fixing fixture 9 (or the assembly) embedded in the pipe body 1 will loosen or fall off from the temporarily fixed position. In view of this, the temporary fixing fixture 9 is configured to be adjustable in the radial direction ( Fig.10 According to such a configuration, by adjusting the length of the temporary fixing fixture 9 in combination with the size of the tube body 1, the temporary fixing fixture 9 (or the assembly) embedded in the tube body 1 can be stabilized, further improving operability. The temporary fixing jig 9 includes a turnbuckle 93 as a length adjusting member and a pair of supporting portions 94a, 94b supporting the turnbuckle 93. The main body 90 is composed of a plurality of split pieces, including a split piece 90a formed with a supporting portion 94a and a split piece 90b formed with a supporting portion 94b. Fig.11 As shown, the segmentation piece 90a and the segmentation piece 90b are provided with mutually fitting and complementary concave and convex parts, which can slide freely relative to each other in the radial direction. The concave and convex parts are composed of a concave part 95 formed on the segmentation piece 90a and a convex part 96 formed on the segmentation piece 90b, but the concave and convex relationship can be opposite to this. In addition, the temporary fixing fixture 9 also includes an elastic member 97 installed on the outer periphery. By locating the elastic member 97 between the tube body 1 and the temporary fixing fixture 9, the temporary fixing fixture 9 can be embedded therein in a state adapted to the tube body 1. The elastic member 97 is formed of rubber such as ethylene propylene rubber (EPDM). The elastic member 97 can be a sponge material formed by foaming rubber or synthetic resin. The outer periphery of the main body 90 is formed with a mounting groove 98 for mounting the elastic member 97. It is also possible to use only one of the above-mentioned length adjustment mechanism and the elastic member 97. In the above-mentioned embodiment, an example is shown in which the tube body 1 (the outer shell 5) has a socket extending in the axial direction, but it is not limited to this. For example, it can also be Fig.12 The pipe body 1 shown in the figure has a flange 16. Even in this form, the locking ring 4 can be installed on the outer peripheral surface of the pipe body 2 according to the above steps. However, when the pipe body 1 has a socket extending in the axial direction, the improvement effect of the installation workability of the locking ring 4 will be particularly obvious. As mentioned above, this is because the pipe body 1 has such a socket, which leads to various disadvantages, such as the tool 35 cannot reach the locking ring 4, etc. (refer to Figure 3 ), operability is likely to deteriorate. In the aforementioned embodiment, when the temporary fixing process or the installation process is implemented, the standard of the axial direction of the tube body 1 is to face the horizontal direction. However, it is not limited to this. For example, the axial direction of the tube body 1 can face the vertical direction so that the opening 1a faces upward. When the tube body 1 has a small diameter, it is not difficult to operate in this longitudinal posture because it is not heavy. In addition, the clamping portion 14 is formed inside the tube body 1 to prevent the assembly 48 from falling off from the temporarily fixed position. The above embodiment shows the assembly method of the telescopic pipe joint 10 as a telescopic flexible pipe joint, but the telescopic pipe joint to which the present disclosure is applicable is not limited to the telescopic pipe joint with bending function (flexibility function). In addition, the pipe body 1 may not include the structure including the outer shell 5 and the intermediate sleeve 6 fitted therewith. Fig.13This is an example of applying the present disclosure to a telescopic pipe joint without a bending function. Except for the configuration described below, this embodiment can be configured in the same manner as the aforementioned embodiment, so the common points will not be described here, and the differences will be mainly introduced. The configurations that have been described are marked with the same reference numerals, and repeated descriptions are omitted. Fig.13 The state before the temporary fixing fixture 8 is removed from the locking ring 4 after the pipe body 2 is inserted into the locking ring 4 in the expanded state during the installation process (refer to Figure 5 (A) in the figure). The tube body 2 is further inserted so that the locking ring 4 is mounted on the outer peripheral surface of the tube body 2, so that the telescopic pipe joint can be properly assembled. In the assembled telescopic pipe joint, the tube body 1 and the tube body 2 inserted therein are connected so as to be relatively movable along the axial direction. The ends of the tube bodies 1 and 2, not shown, are provided with, for example, Fig.12 The telescopic flexible pipe joint shown in the figure can extend the telescopic amount of the telescopic pipe joint in the pipeline between a pair of telescopic flexible pipe joints. exist Fig.13 In the embodiment, the assembly 48 is embedded in the tube body 1 through a temporary fixing process. However, unlike the aforementioned embodiment, the assembly 48 is not embedded through an intermediate sleeve. Therefore, it is necessary to set the temporary fixing fixture 8 inside the tube body 1 from the opening 1a on the side of the disengagement direction D2. A notched portion, not shown, is formed in the opening 1a of the tube body 1 or the engaged portion 17, and the notched portion allows the locking ring 4 to pass through in a posture in which the axial core direction and the radial direction of the tube body 1 are consistent. After the locking ring 4 passes through the notched portion and is set inside the tube body 1, the locking ring 4 can be changed to a posture that is coaxial with the tube body 1 by rotating the locking ring 4 in the annular circumferential groove 13. The embodiments of the present disclosure are described above, but the specific configuration is not limited to these embodiments. The present disclosure is not limited to the above embodiments in any way, and various improvements and changes can be made within the scope of the present disclosure. In addition, the various configurations used in the above embodiments can be used in any combination. As described above, the embodiment of the present disclosure utilizes a temporary fixing jig to install the locking ring on the outer peripheral surface of the tube body, while the reference example which does not use such a temporary fixing jig is based on Figures 14 to 24 Provide explanation. [Reference example] The invention of this reference example relates to a telescopic pipe joint with a telescopic structure and an assembling method of the telescopic pipe joint. The telescopic pipe joint includes: a docking head having a first joint part and a second joint part; and a connecting sleeve connected to the first joint part and the second joint part. The above-mentioned expansion joint is used as a joint of a water pipe, etc., and includes an expansion structure to absorb the external force when an earthquake or the like occurs. Such an expansion joint, for example, includes a connecting sleeve and a first joint part and a second joint part that are engaged and connected, and a joint-side expansion structure is provided between a pair of butt joints and the connecting sleeve (for example, refer to Japanese Patent No. 3184481 (hereinafter referred to as Patent Document 3)). In the telescopic pipe joint described in Patent Document 3, the joint side connecting portion of the connecting sleeve is embedded in the first joint portion and the second joint portion in a manner that the joint portion can move relative to each other along the pipe axial direction, so that the joint side has a joint side telescopic structure. However, the telescopic range of the joint side telescopic structure is limited to the length of the joint portion in the pipe axial direction, and in some cases, it may be necessary to expand the telescopic range of the telescopic structure. Therefore, a telescopic pipe joint is proposed, which not only has a joint-side telescopic structure between the joint part and the connecting sleeve, but also includes an inner sleeve and an outer sleeve as a connecting sleeve, and also has a sleeve-side telescopic structure between the inner sleeve and the outer sleeve (for example, refer to Japanese Patent Gazette No. 4409668 (hereinafter referred to as Patent Document 4)). In the telescopic pipe joint described in Patent Document 4, a sleeve-side connection portion on the opposite side of the joint-side connection portion in the inner sleeve is relatively movably embedded in a sleeve-side connection portion on the opposite side of the joint-side connection portion in the outer sleeve along the pipe axial direction, thereby providing a sleeve-side telescopic structure between the inner sleeve and the outer sleeve. The sleeve-side connection portion of the outer sleeve is enlarged to a diameter larger than the joint-side connection portion, so that the sleeve-side connection portion of the inner sleeve can be freely embedded in the sleeve-side connection portion of the outer sleeve. As described above, the telescopic pipe joint described in Patent Document 4 has not only a joint-side telescopic structure but also a sleeve-side telescopic structure, thereby satisfying the requirement of expanding the telescopic range of the telescopic structure. However, in the telescopic pipe joint described in Patent Document 4, complicated work must be performed when assembling the telescopic pipe joint, resulting in cumbersome and complicated assembly work. In the telescopic pipe joint described in patent document 4, a locking mechanism and a seal are provided between the sleeve side connection portion of the inner sleeve and the sleeve side connection portion of the outer sleeve to limit the relative movement range between the inner sleeve and the outer sleeve, and the locking mechanism is arranged at a position closer to the side (inner side) having the inner sleeve than the seal in the axial direction of the pipe. Therefore, when assembling the expansion joint, when the sleeve-side connection part of the inner sleeve is inserted into the sleeve-side connection part of the outer sleeve, a process of setting a locking mechanism is performed, and then a process of installing a seal between the sleeve-side connection part of the inner sleeve and the sleeve-side connection part of the outer sleeve is performed. Therefore, in the process of installing the seal, a complicated operation is required, such as fitting the sleeve component into the gap between the sleeve-side connection parts while the sleeve-side connection part of the inner sleeve is inserted into the sleeve-side connection part of the outer sleeve, etc., which increases the number of parts and makes the assembly operation cumbersome and complicated. In view of this situation, the main problem of the invention of this reference example is to provide a telescopic pipe joint and an assembling method of the telescopic pipe joint, which can expand the telescopic range of the telescopic structure and simplify the assembly work. The first characteristic configuration of the invention of the reference example is that a telescopic pipe joint with a telescopic structure comprises: a butt joint having a first joint part and a second joint part; and a connecting sleeve connected to the first joint part and the second joint part. As the connecting sleeve, it includes: A first sleeve, wherein the joint-side connecting portion is embedded in the first joint portion in a relatively movable manner along the axial direction of the tube, and a joint-side telescopic structure is provided between the first joint portion and the first joint portion; and The second sleeve has a joint-side connecting portion which is embedded in the second joint portion in a relatively movable manner along the axial direction of the tube, and has a joint-side telescopic structure between the second joint portion and the second joint portion. A sleeve side telescopic structure is provided between the first sleeve and the second sleeve, which is configured such that the sleeve side connection part on the side opposite to the joint side connection part in the first sleeve is embedded in the sleeve side connection part on the side opposite to the joint side connection part in the second sleeve in a relatively movable manner along the tube axial direction. The end portion of the sleeve-side connecting portion of the second sleeve into which the first sleeve is inserted has a sealing member, which seals between the inner circumference of the second sleeve and the outer circumference of the first sleeve. The end portion of the sleeve-side connecting portion of the first sleeve inserted into the second sleeve has a locking ring, which abuts against the inner circumference of the second sleeve to limit the relative movement range of the second sleeve and the first sleeve in the axial direction of the tube to a predetermined range. The interior of the second sleeve has a moving-in operation space, and the locking ring can be moved in an expanded diameter state from the side where the joint side connecting part of the second sleeve is located into the locking ring setting part where the locking ring is provided in the axial direction of the tube. According to this configuration, not only the joint side telescopic structure is provided between the first sleeve and the first joint part, and between the second sleeve and the second joint part, but also the sleeve side telescopic structure is provided between the first sleeve and the second sleeve by fitting the first sleeve as the inner side and the second sleeve as the outer side. Thus, the requirement of expanding the telescopic range of the telescopic structure can be met. Moreover, since the end portion of the sleeve-side connecting portion of the second sleeve into which the first sleeve is inserted has a seal and the end portion of the sleeve-side connecting portion of the first sleeve inserted into the second sleeve has a locking ring, a sealing function between the first sleeve and the second sleeve and a mechanism for limiting the relative movement range within a predetermined range can be appropriately provided. Furthermore, since the second sleeve has a moving-in operation space inside, the locking ring can be moved into the locking ring setting portion of the locking ring in an expanded state from the side where the joint side connection portion of the second sleeve is located in the axial direction of the tube. Therefore, when setting the locking ring inserted into the second sleeve, the installation tool can be inserted into the second sleeve from the side where the joint side connection portion of the second sleeve is located in the axial direction of the tube, and the locking ring can be set in the locking ring setting portion in an expanded state by using the moving-in operation space. Thus, the moving-in operation space can be effectively utilized, and the locking ring can be easily set, which can simplify the assembly work. The second characteristic configuration of the invention of this reference example is that, in the telescopic pipe joint described in the first characteristic configuration, The second sleeve has a movement-allowing space inside to allow the locking ring to move in the axial direction of the tube. The second sleeve has an expanded diameter portion, the expanded diameter portion is expanded to a diameter larger than the end portion of the sleeve side connecting portion, The movement-allowing space and the moving-in operation space are formed by the enlarged diameter portion. According to this configuration, the second sleeve has only an expanded diameter portion that is expanded to a larger diameter than the end portion of the sleeve-side connecting portion, so that a movement allowance space and a moving-in operation space can be formed in the expanded diameter portion, thereby simplifying the structure. The third characteristic configuration of the invention of the reference example is that, in the telescopic pipe joint described in the second characteristic configuration, The second sleeve has: a reduced diameter portion whose diameter is reduced to be smaller than that of the expanded diameter portion; and a connecting portion extending in the radial direction of the second sleeve and connecting the expanded diameter portion and the reduced diameter portion. The end of the sleeve-side connecting portion of the first sleeve abuts against the inner peripheral portion of the connecting portion of the second sleeve to limit the relative movement range of the second sleeve and the first sleeve in the tube axial direction to a predetermined range. According to this configuration, since the second sleeve has a reduced diameter portion whose diameter is reduced to a smaller diameter than the enlarged diameter portion, the reduced diameter portion can be placed on the joint side connection portion of the second sleeve by making the outer diameter of the reduced diameter portion the same or substantially the same as the outer diameter of the first sleeve. Thus, the diameter of the joint side connection portion of the first sleeve and the joint side connection portion of the second sleeve can be made the same or substantially the same, and therefore, the same joint portion can be used as the first joint portion and the second joint portion to be connected, which can simplify the joint portion structure and reduce costs. Moreover, in the second sleeve, when the reduced diameter portion is provided, not only a connecting portion can be simply provided, but the inner peripheral portion of the connecting portion can also be made to abut against the end portion of the sleeve side connecting portion of the first sleeve, and used as a component for limiting the relative movement range within a predetermined range, thereby achieving structural simplification. The fourth characteristic configuration of the invention of the reference example is that in the expansion joint described in any one of the first to third characteristic configurations, The inner circumference of the end portion of the sleeve-side connecting portion of the second sleeve has a seal setting portion for setting the seal. The seal setting portion has an insertion groove portion, and the lock ring having an outer diameter larger than an inner diameter of the seal setting portion can be freely inserted into the interior of the second sleeve in an insertion posture different from a mounting posture. When assembling the expansion joint, the lock ring needs to be inserted into the second sleeve. However, if the seal setting portion and the lock ring interfere with each other, the lock ring cannot be inserted into the second sleeve. Therefore, according to this configuration, since the seal setting portion has the insertion groove, the lock ring can be correctly inserted into the second sleeve by passing the lock ring in the insertion posture through the insertion groove. The fifth characteristic configuration of the invention of the reference example is that, in the telescopic pipe joint described in the fourth characteristic configuration, The seal member installation portion has a fitting groove portion for fitting the seal member. The groove depths of the fitting groove and the insertion groove are set so that the groove bottom is located on the outer side of the fitting groove relative to the insertion groove in the radial direction of the second sleeve. According to this configuration, since the groove depths of the fitting groove and the insertion groove are set so that the bottom of the groove is located on the radially outer side of the fitting groove than the insertion groove, the seal can be fitted in the fitting groove at the position where the insertion groove is formed. Therefore, even if the insertion groove is formed in the seal setting portion, the seal can be properly fitted in the fitting groove, so that, for example, the occurrence of an undesirable situation such as a part of the seal popping out of the fitting groove due to fluid pressure such as water pressure can be prevented, so that the original sealing function can be properly exerted. The sixth characteristic configuration of the invention of the reference example is that a method for assembling a telescopic pipe joint of any one of the first to fifth characteristic configurations is performed by the following steps: The first step is to insert the locking ring into the second sleeve; The second step is to insert the first sleeve into the second sleeve while the seal is installed at the end of the sleeve-side connecting portion of the second sleeve; A third step is to provide the locking ring inserted into the second sleeve at the end portion of the sleeve-side connecting portion of the first sleeve inserted into the second sleeve; and The fourth step is to embed the joint side connection part of the first sleeve into the first joint part, connect the first sleeve to the first joint part, embed the joint side connection part of the second sleeve into the second joint part, and connect the second sleeve to the second joint part. In the third step, the installation tool is inserted into the interior of the second sleeve from the side where the joint side connection part of the second sleeve is located in the axial direction of the pipe, and the locking ring is set at the end part of the sleeve side connection part of the first sleeve using the moving operation space. According to this configuration, the expansion joint can be assembled in an orderly manner by performing the first to fourth steps. Furthermore, in the third step, since the installation tool is inserted into the second sleeve from the side where the joint-side connection portion of the second sleeve is located in the axial direction, and the lock ring is set using the insertion operation space, the insertion operation space can be effectively used and the lock ring can be easily set. The seventh characteristic configuration of the invention of the reference example is that, in the assembling method of the expansion joint described in the sixth characteristic configuration, The inner circumference of the end portion of the sleeve-side connecting portion of the second sleeve has a seal setting portion for setting the seal. The seal setting part has an insertion groove part so that the locking ring having an outer diameter larger than the inner diameter of the seal setting part can be freely inserted into the interior of the second sleeve. In the first step, the following steps are performed: an insertion step of placing the lock ring in an insertion posture with its axial direction being orthogonal to the axial direction of the second sleeve, and inserting the lock ring in the insertion posture through the insertion groove into the second sleeve; and The posture changing step is to change the posture of the locking ring in the insertion posture to a mounting posture inside the second sleeve, wherein the axial direction of the locking ring is consistent with the axial direction of the second sleeve. In the first step, the lock ring needs to be inserted into the second sleeve. However, if, for example, the seal setting portion interferes with the lock ring, the lock ring cannot be inserted into the second sleeve. Therefore, according to this configuration, since the seal setting portion has the insertion groove, the insertion groove can be effectively used in the insertion step of the first step, so that the lock ring in the insertion posture passes through the insertion groove and is correctly inserted into the second sleeve. Then, by performing the posture changing step, the posture can be changed to the installation posture, so that the axial direction of the lock ring is consistent with the tube axial direction of the second sleeve, and the lock ring is installed in the correct posture. Embodiments of the expansion pipe joint of the present reference example invention will be described based on the drawings. like Figures 14 to 16 As shown, the telescopic pipe joint 100 is used as a joint for a water pipe, etc., and includes: a butt joint, a first joint part 101 ( Figures 14 to 16 The left side of the figure) and the second joint portion 102 ( Figures 14 to 16 and a cast iron connecting sleeve 103 connected to the first joint portion 101 and the second joint portion 102. The connecting sleeve 103 includes a cylindrical first sleeve 104 engaged with the first joint portion 101 and a cylindrical second sleeve 105 engaged with the second joint portion 102. like Figures 14 to 16 As shown, the joint side connection portion 41 of the first sleeve 104 is moved along the pipe axial direction ( Figures 14 to 16 The first sleeve 104 is freely embedded in the first joint part 101 in a relatively movable manner (in the left and right directions), so that a joint-side telescopic structure 106 is provided between the first joint part 101 and the first sleeve 104. Similarly, the joint-side connecting part 51 of the second sleeve 105 is freely embedded in the second joint part 102 in a relatively movable manner along the axial direction of the tube, so that a joint-side telescopic structure 107 is provided between the second joint part 102 and the second sleeve 105. The sleeve-side connecting part 42 on the opposite side of the joint-side connecting part 41 in the first sleeve 104 is freely embedded in the sleeve-side connecting part 52 on the opposite side of the joint-side connecting part 51 in the second sleeve 105 in a relatively movable manner along the axial direction of the tube, so that a sleeve-side telescopic structure 108 is provided between the first sleeve 104 and the second sleeve 105. In this way, not only are there joint-side telescopic structures 106 and 107 between the first joint part 101 and the first sleeve 104, and between the second joint part 102 and the second sleeve 105, but the first sleeve 104 is used as the inner side and the second sleeve 105 is used as the outer side for interlocking, so that there is also a sleeve-side telescopic structure 108 between the first sleeve 104 and the second sleeve 105, thereby fully meeting the requirement of expanding the telescopic range of the telescopic structure. Fig.14The figure shows a standard state in which the telescopic pipe joint 100 is located at a middle position in the telescopic range in the telescopic structures of the joint-side telescopic structures 106 and 107 and the sleeve-side telescopic structure 108 . Fig.15 The telescopic structure of the joint-side telescopic structures 106 and 107 and the sleeve-side telescopic structure 108 is shown in the minimum contraction state where the telescopic pipe joint 100 is located at the minimum position in the telescopic range. Fig.16 The telescopic structure of the joint-side telescopic structures 106 and 107 and the sleeve-side telescopic structure 108 is shown in the maximum extended state where the telescopic pipe joint 100 is located at the maximum position in the telescopic range. The following is mainly based on Fig.14 Each structure of the expansion pipe joint 100 will be described. 〔First joint〕 Fig.14 The first joint part 101 on the left side includes: a cylindrical outer joint body 11, having a water pipe side connection part 11a, which can be freely connected to a water pipe, etc.; and a spherical (a hollow sphere after both sides of the pipe axis direction are cut) inner joint body 12, having a spherical outer peripheral surface 12a, which can be freely slidably embedded in the spherical inner peripheral surface 11b of the outer joint body 11. The spherical inner surface 11b of the outer joint body 11 is embedded in the spherical outer surface 12a of the inner joint body 12 embedded in the first sleeve 104 in a manner that can be freely bent in three-dimensional directions, thereby having a bending structure so that the first sleeve 104 can be freely bent relative to the first joint part 101. The water pipe side connection part 11a of the outer joint body 11 has an annular connection flange 11c. It is configured so that a water pipe or the like can be freely fixedly connected to the connection flange 11c in the pipe axial direction by fasteners such as bolts and nuts. A connection opening 11d is provided on the side opposite to the water pipe side connection part 11a of the outer joint body 11 in the pipe axial direction, and the inner joint body 12 and the first sleeve 104 can be freely inserted and removed from the connection opening 11d. The outer joint body 11 has a tie rod mounting portion 11f at the maximum inner diameter portion on the spherical inner peripheral surface 11b, which is extended radially outward from the outer joint body 11. The tie rod mounting portion 11f is not shown, and is used to mount the tie rod in a state spanning the first joint portion 101 and the second joint portion 102. By mounting the tie rod across the first joint portion 101 and the second joint portion 102, the telescopic pipe joint 100 can be made unable to expand and contract and unable to bend during transportation. A first rubber ring G1 serving as a seal is installed in the annular seal installation groove 11g formed at the maximum inner diameter portion on the spherical inner peripheral surface 11b of the outer joint body 11 so as to freely slide between the rubber ring G1 and the spherical outer peripheral surface 12a of the inner joint body 12 to provide a watertight seal. The inner circumferential side of the inner joint body 12 is formed with: a fitting inner circumferential surface 12b that can be freely slidably fitted into the outer circumferential surface of the first sleeve 104, and a radially outer side ( Fig.14 The second rubber ring G2 as a seal is installed in the annular seal installation groove 12d formed on the chimeric inner peripheral surface 12b of the inner joint body 12, so as to freely slide between the outer peripheral surface of the first sleeve 104 to perform watertight sealing. The end portion of the outer peripheral surface of the joint-side connecting portion 41 of the first sleeve 104 is formed with a circular locking ring installation groove 41a, in which the first locking ring R1 is fitted. Fig.14 As shown, the first locking ring R1 is arranged at a position spaced apart from and opposite to the annular recess 12c formed on the inner circumference of the inner joint body 12, and the annular recess 12c forms a first movement allowable space K1, allowing the first locking ring R1 to move in the axial direction of the tube. Fig.15 and at maximum extension Fig.16 As shown, the end portion of the annular recess 12c in the pipe axial direction is brought into contact with the first lock ring R1, thereby limiting the telescopic range of the joint-side telescopic structure 106 to a predetermined range. 〔Second joint〕 Fig.14 The second joint part 102 on the right side is the same joint part as the first joint part 101 and has the same structure as the first joint part 101. Therefore, the same names as the names of the various structures of the first joint part 101 are given, and detailed description is omitted, and a brief description is given. It should be noted that, regarding the markings, the various structures of the first joint part 101 are marked as 11, 11a~g, 12, 12a~d, and the various structures of the second joint part 102 are marked as 21, 21a~g, 22, 22a~d. Similar to the first joint part 101, the second joint part 102 also includes an outer joint body 21 and an inner joint body 22. Similar to the outer joint body 11 of the first joint part 101, the outer joint body 21 has a water pipe side connection part 21a, a spherical inner peripheral surface 21b, a connecting flange 21c, a connection opening 21d, a tie rod mounting part 21f, and a sealing mounting groove 21g. Similar to the inner joint body 12 of the first joint part 101, the inner joint body 22 has a spherical outer peripheral surface 22a, a fitting inner peripheral surface 22b, an annular recess 22c, and a sealing mounting groove 22d. A third rubber ring G3 serving as a seal is installed in the sealing installation groove 21g of the outer joint body 21, so as to be able to slide freely between the spherical inner peripheral surface 21b of the outer joint body 21 and the spherical outer peripheral surface 22a of the inner joint body 22 to perform a watertight seal. A fourth rubber ring G4 serving as a seal is installed in the sealing installation groove 22d of the inner joint body 22, so as to be able to slide freely between the mating inner peripheral surface 22b of the inner joint body 12 and the outer peripheral surface of the second sleeve 105 to perform a watertight seal. The end portion of the outer peripheral surface of the joint-side connecting portion 51 of the second sleeve 105 is formed with a circular locking ring installation groove 51a, and the second locking ring R2 is embedded in the locking ring installation groove 51a. Fig.14 As shown, the second locking ring R2 is arranged at a position spaced apart from the annular recess 22c formed on the inner circumference of the inner joint body 22, and the annular recess 22c forms a second movement allowable space K2, allowing the second locking ring R2 to move in the axial direction of the tube. Fig.15 and at maximum extension Fig.16 As shown, by causing the end of the annular recess 22c in the pipe axial direction to abut against the second lock ring R2, the telescopic range of the joint-side telescopic structure 107 is restricted within a predetermined range. [Connection structure between the first sleeve and the second sleeve] The sleeve-side connecting portion 42 of the first sleeve 104 is relatively movably embedded in the sleeve-side connecting portion 52 of the second sleeve 105 along the tube axis direction, and the first sleeve 104 is placed inside and the second sleeve 105 is placed outside for fitting connection. The first sleeve 104 is composed of a cylindrical tube with the same outer diameter and extending linearly in the axial direction of the tube. The second sleeve 105 is composed of a cylindrical tube with a varying outer diameter in the axial direction of the tube. The second sleeve 105 includes: a fitting portion 53, which is freely slidably fitted on the outer circumference of the first sleeve 104 from the sleeve side connection portion 52 side toward the joint side connection portion 51 side in the axial direction of the tube; an expanding portion 54, which is expanded to a diameter larger than the embedding portion 53; and a reducing portion 55, which is reduced to a diameter smaller than the expanding portion 54. The reduced diameter portion 55 of the second sleeve 105 is formed so that its outer diameter A1 is the same as or substantially the same as the outer diameter A2 of the first sleeve 104, and the reduced diameter portion 55 is provided as the joint-side connection portion 51 of the second sleeve 105. Thus, the joint-side connection portion 41 of the first sleeve 104 and the reduced diameter portion 55 as the joint-side connection portion 51 of the second sleeve 105 can be made to have the same diameter or substantially the same diameter, and therefore, the same joint portion can be used as the first joint portion 101 and the second joint portion 102 to be connected. The fitting portion 53 of the sleeve-side connecting portion 52 of the second sleeve 105 has a seal setting portion 56 for setting a seal. The seal setting portion 56 is provided with a fifth rubber ring G5 as a seal, and performs a watertight seal in a manner that can freely slide between the seal and the outer peripheral surface of the first sleeve 104. The seal setting portion 56 has a fitting groove portion 57 in which the fifth rubber ring G5 can be freely fitted, and the fifth rubber ring G5 is fitted and installed in the fitting groove portion 57. The outer peripheral surface of the sleeve side connecting portion 42 of the first sleeve 104 has an annular locking ring installation groove 42a at the end portion thereof, and a third locking ring R3 is fitted and installed in the locking ring installation groove 42a. The third locking ring R3 abuts against the inner peripheral portion of the second sleeve 105 to limit the relative movement range of the first sleeve 104 and the second sleeve 105 in the axial direction of the tube within a predetermined range. As standard Fig.14 As shown, the third locking ring R3 is arranged at a position opposite to the inner circumference of the enlarged diameter portion 54 of the second sleeve 105 with a spacing therebetween. The enlarged diameter portion 54 forms a third movement allowable space K3, allowing the third locking ring R3 to move in the axial direction of the tube. The end portion of the fitting portion 53 on the inner circumference of the second sleeve 105 is arranged in the radial direction of the second sleeve 105 ( Fig.14 The position in the vertical direction in the middle) that can abut against the third locking ring R3. Fig.16 As shown, by abutting the inner end portion of the fitting portion 53 with the third lock ring R3, the range of the extension side of the relative movement range of the first sleeve 104 and the second sleeve 105 in the tube axial direction is restricted. The second sleeve 105 has a connecting portion 58 between the expanded diameter portion 54 and the reduced diameter portion 55, which extends in the radial direction of the second sleeve 105 and connects the expanded diameter portion 54 and the reduced diameter portion 55. The connecting portion 58 is formed in an inclined shape that gradually decreases in diameter from the expanded diameter portion 54 to the reduced diameter portion 55 in the axial direction of the tube. The end portion of the reduced diameter portion 55 side on the inner circumference of the connecting portion 58 is provided in the radial direction of the second sleeve 105 ( Fig.14 The position in the vertical direction in the middle (in the vertical direction in the middle) that can abut against the end portion of the sleeve side connecting portion 42 of the first sleeve 104. By abutting the end portion of the sleeve side connecting portion 42 of the first sleeve 104 against the end portion of the inner circumferential upper reduced diameter portion 55 side of the connecting portion 58, the range of the contraction side in the relative movement range of the first sleeve 104 and the second sleeve 105 in the tube axial direction is limited. In this way, the length of the enlarged diameter portion 54 in the tube axial direction corresponds to the size of the predetermined range of relative movement of the sleeve side telescopic structure 108. In this embodiment, by making the length of the enlarged diameter portion 54 in the tube axial direction longer than the reduced diameter portion 55, as the sleeve side telescopic structure 108, a larger relative movement range can be ensured. Next, a method of assembling the expansion pipe joint 100 will be described. In this embodiment, the expansion joint 100 is assembled by performing four steps, namely, the first step to the fourth step. Fig. 20 As shown, the first step is to insert the third locking ring R3 into the second sleeve 105. Fig.21 As shown, the second process is to insert the first sleeve 104 into the second sleeve 105. Fig.21 As shown, the third step is to set the third locking ring R3 on the sleeve side connecting portion 42 of the first sleeve 104. Figures 22 to 24 As shown, the fourth step is to connect the first sleeve 104 to the first joint part 101 , and to connect the second sleeve 105 to the second joint part 102 . 〔First process〕 In the first step, Fig. 20 As shown, the third locking ring R3 is inserted into the interior of the second sleeve 105 . Fig. 20 (A) is a diagram showing a process of inserting the third locking ring R3 into the interior of the second sleeve 105, Fig. 20 (B) in FIG. 1 is a diagram showing a state where the third lock ring R3 is inserted into the second sleeve 105 . like Fig. 20 As shown in (A), when the third locking ring R3 is inserted into the interior of the second sleeve 105, an insertion process is performed to make the third locking ring R3 in an insertion posture, and its axial direction (direction perpendicular to the paper surface) is orthogonal to the axial direction of the second sleeve 105, and the third locking ring R3 in the insertion posture is inserted into the interior of the second sleeve 105. Here, the third locking ring R3 is further described as follows: Fig. 20 As shown in (A) of FIG. 1 , the third locking ring R3 is C-shaped and can be elastically deformed on the diameter expansion side after being cut and separated at one point in the circumferential direction. The two ends after the cutting and separation are formed with engaging holes R3a, and the installation tool 810 (refer to FIG. 1 ) for performing the diameter expansion operation on the third locking ring R3 is used. Fig.21 The two locking parts of (B)) can be engaged and disengaged. In the insertion process, the third lock ring R3 in the insertion posture needs to be inserted into the second sleeve 105 from the end side of the sleeve side connection part 52 provided with the seal setting part 56 in the second sleeve 105. At this time, the size relationship between the inner diameter of the seal setting part 56 of the second sleeve 105 and the outer diameter of the third lock ring R3 is that the inner diameter B1 of the end opening of the seal setting part 56 is formed to be smaller than the outer diameter B2 of the third lock ring R3, as shown in FIG. Fig.17Therefore, even if the third locking ring R3 is in the insertion posture, the movement into the interior of the second sleeve 105 will be blocked by the seal setting portion 56, resulting in the inability to insert the third locking ring R3 in the insertion posture into the interior of the second sleeve 105. It should be noted that Fig.17 (A) is a longitudinal cross-sectional view of the second sleeve 105, Fig.17 (B) is when the end of the sleeve side connecting portion 52 of the second sleeve 105 is observed from the direction along the axial direction of the tube. Fig.17 The arrow view at line BB in (A) is shown below. Fig.17 (C) in FIG. 1 is a diagram showing the third lock ring R3 . Therefore, if Fig.17 As shown in (B) in FIG. 1 , the seal setting portion 56 has an insertion groove 71, which allows the third lock ring R3 in the inserted posture to be freely inserted into the second sleeve 105. The insertion groove 71 is formed at two opposite locations in the radial direction of the second sleeve 105, and allows the upper end and the lower end of the third lock ring R3 in the inserted posture to pass freely. The insertion groove 71 is formed so that the lateral width C2 of the second sleeve 105 in the circumferential direction is larger than the lateral width C1 of the third lock ring R3 by a predetermined width (for example, 5 mm). like Fig.18 and Fig.19 As shown, the seal setting portion 56 is formed with an engagement groove portion 57 in which the fifth rubber ring G5 is engaged and installed. The first protrusion 56a, the second protrusion 56b and the third protrusion 56c protruding radially inward in the second sleeve 105 form the engagement groove portion 57 into a concave-convex shape. Fig.18 As shown in (A) in FIG. 1 , the fifth rubber ring G5 is fitted in the fitting groove 57 in a state where the concavo-convex fifth rubber ring G5 is fitted between the first protrusion 56a and the second protrusion 56b or between the second protrusion 56b and the third protrusion 56c. like Fig.18 (B) and Fig.19 As shown, the insertion groove 71 is formed by cutting off a predetermined amount of the first protrusion 56a, the second protrusion 56b, and the third protrusion 56c. Fig.17 (B) and Fig.18 As shown in (B) in FIG. 1 , the groove depths of the fitting groove portion 57 and the insertion groove portion 71 of the seal setting portion 56 are set so that the flat groove bottom 57a of the fitting groove portion 57 is closer to the radial outside of the second sleeve 105 than the flat groove bottom 71a of the insertion groove portion 71 ( Fig.18 (B) in the upper side). It should be noted that Fig.17In (B), the fifth rubber ring G5 is indicated by a dotted line, and the radially outer end portion of the fifth rubber ring G5 serves as a sealing surface that contacts the groove bottom 57 a of the fitting groove portion 57 . Thus, the groove bottom 57a of the fitting groove portion 57 that contacts the fifth rubber ring G5 to form a sealing surface is located radially outward of the second sleeve 105 relative to the groove bottom 71a of the insertion groove portion 71 located radially outward of the second sleeve 105. Therefore, the fitting amount (fitting length) between the fifth rubber ring G5 and the fitting groove portion 57 in the radial direction of the second sleeve 105 can be ensured to a greater extent, so even if the insertion groove portion 71 is formed in the fitting groove portion 57, it is possible to prevent a part of the fifth rubber ring G5 from being ejected from the fitting groove portion 57 due to fluid pressure such as water pressure. Returns a description of the first process's operations, such as Fig. 20 As shown in (A) in FIG. 1 , the insertion process is performed, and the third locking ring R3 in the insertion posture is passed through the insertion groove 71 and inserted into the interior of the second sleeve 105, and then, as shown in FIG. Fig. 20 As shown in (B) in the figure, a posture changing step is performed to change the posture of the third lock ring R3 in the insertion posture to the installation posture inside the second sleeve 105 so that its axial direction is consistent with the tube axial direction of the second sleeve 105. In this way, in the first step, the third lock ring R3 is set inside the second sleeve 105 in the installation posture by performing the insertion step and the posture changing step. 〔Second process〕 In the second step, Fig.21 As shown in (A) of FIG. 1 , the first sleeve 104 is inserted into the second sleeve 105 while the fifth rubber ring G5 is mounted on the seal setting portion 56 of the sleeve side connecting portion 52 of the second sleeve 105. At this time, after applying a proper amount of lubricant to the outer periphery of the first sleeve 104 or the fifth rubber ring G5, the outer periphery of the first sleeve 104 and the fifth rubber ring G5 are slid, and the first sleeve 104 is inserted into the second sleeve 105, so that the first sleeve 104 is embedded in the second sleeve 105. 〔Third process〕 In the third step, Fig.21 As shown in (A) in FIG. 1 , a third lock ring R3 inserted into the second sleeve 105 is provided in the lock ring installation groove 42 a of the sleeve-side connecting portion 42 of the first sleeve 104 inserted into the second sleeve 105 . In the third step, if Fig.21 As shown in (A) in the figure, first, the installation tool 810 is inserted into the second sleeve 105 from the side where the joint side connection portion 51 of the second sleeve 105 is located in the axial direction of the pipe, as shown in FIG. Fig.21As shown in (B) in FIG. 1 , the installation tool 810 is engaged in the engagement hole R3a of the third locking ring R3 to overcome the elastic restoring force and expand the diameter of the third locking ring R3. Fig.21 As shown in (A), the third locking ring R3 is moved (moved) into the space between the inner circumference of the second sleeve 105 and the outer circumference of the first sleeve 104 after the diameter expansion operation, and the diameter expansion operation force is released at the position corresponding to the locking ring mounting groove 42a, so that the third locking ring R3 is reduced in diameter due to the elastic restoring force and is embedded and retained in the locking ring mounting groove 42a. Thus, in order to place the third locking ring R3 in the locking ring installation groove 42a, the interior of the second sleeve 105 has a moving-in operation space 61, such as Fig.14 and Fig.21 As shown in (A), the third locking ring R3 can be moved into the locking ring installation groove 42a (equivalent to the locking ring setting part) in the axial direction of the tube in an expanded state from the side where the joint side connecting part 51 of the second sleeve 105 is located. like Fig.14 and Fig.21 As shown in (A) in FIG. 1 , the moving-in operation space 61 is formed by the enlarged diameter portion 54 of the second sleeve 105 as a space that is expanded to the radial outside relative to the outer periphery of the first sleeve 104. The moving-in operation space 61 includes: a radially extending space 61a that is connected to and extends in communication with the locking ring mounting groove 42a; and a tube axial direction extending space 61b that is connected to and extends in communication with the joint side connection portion 51 side of the second sleeve 105 in the tube axial direction relative to the radially extending space 61a. The moving-in operation space 61 is a series of spaces that extend from a space that is expanded to the radial outside relative to the outer periphery of the first sleeve 104 at a position corresponding to the locking ring mounting groove 42a in the tube axial direction to a side where the joint side connection portion 51 of the second sleeve 105 is located. By forming the moving-in operation space 61 in this way, when setting the third locking ring R3 to be inserted into the interior of the second sleeve 105, the third locking ring R3 that has been expanded using the installation tool 810 can be smoothly moved in (moved) to a position corresponding to the locking ring installation groove 51a through the axial extension space 61b and the radial extension space 61a in the moving-in operation space 61, thereby simplifying the setting operation of the third locking ring R3. [Fourth process] In the fourth step, if Figure 22 to Figure 24As shown, the following processes are performed: a first connection process, embedding the joint side connection part 41 of the first sleeve 104 into the first joint part 101 to connect the first sleeve 104 with the first joint part 101; and a second connection process, embedding the joint side connection part 51 of the second sleeve 105 into the second joint part 102 to connect the second sleeve 105 with the second joint part 102. The operations of the first connection process and the second connection process are basically the same, and the only difference is whether the connected parts are connecting the first sleeve 104 and the first joint part 101, or connecting the second sleeve 105 and the second joint part 102. Fig. 22 and Fig.23 , the second connection process of connecting the second sleeve 105 to the second joint part 102 is described, and the detailed description of the first connection process of connecting the first sleeve 104 to the first joint part 101 is omitted. In the second connection process, the following steps are performed: Fig. 22 The locking ring insertion process shown in (A) Fig. 22 The inner joint body installation process shown in (B) Fig.23 The cannula insertion step shown in (A) and Fig.23 The locking ring installation process shown in (B) in FIG. During the locking ring insertion process, Fig. 22 As shown in (A) in FIG. 1 , the second lock ring R2 is placed in an insertion posture with its axial direction being orthogonal to the tube axial direction of the inner joint body 22 of the second joint portion 102 , so that the second lock ring R2 in the insertion posture is inserted into the inner joint body 22 . With the third locking ring R3 (refer to Fig. 20 The second locking ring R2 is similar to (A) in FIG. 1 , and is also C-shaped and can be elastically deformed on the expanded diameter side after being cut and separated at one point in the circumferential direction. The two ends after the cutting and separation are formed with engaging holes R2a, and the installation tool 810 (refer to FIG. 1 ) for expanding the diameter of the second locking ring R2 is used. Fig.21 The two locking parts of (B)) can be engaged and disengaged. The inner diameter of the opening of the inner joint body 22 on the side where the second locking ring R2 is inserted is formed to be smaller than the outer diameter of the second locking ring R2. Fig. 22 As shown on the left side of (B), the second locking ring R2 in the inserted posture can be freely inserted into the inner joint body 22. The cutout portion 22e is formed at two radially opposite locations in the inner joint body 22, so that the upper end and the lower end of the second locking ring R2 in the inserted posture can pass freely. So, like Fig. 22As shown in (A), when the second locking ring R2 in the insertion posture is inserted through the cutout portion 22e to the inside of the inner joint body 22, the second locking ring R2 in the insertion posture is transformed into a mounting posture inside the inner joint body 22, and its axial direction is consistent with the axial direction of the tube of the inner joint body 22. Fig. 22 In (A), the second lock ring R2 in the inserted posture is indicated by a dashed line, and the second lock ring R2 after the posture is changed to the mounted posture is indicated by a solid line. During the installation process of the inner joint body, Fig. 22 As shown in (B) in FIG. 1 , the inner joint body 22 is placed in an insertion posture with its axial direction being orthogonal to the tube axial direction of the outer joint body 21 of the second joint portion 102, so that the inner joint body 22 in the insertion posture is inserted into the inner part of the outer joint body 21. When the inner joint body 22 in the insertion posture is inserted into the inner part of the outer joint body 21, an appropriate amount of lubricant is applied to the outer periphery of the third rubber ring G3 and the inner joint body 22 in a state where the third rubber ring G3 is installed in the seal installation groove 21g of the outer joint body 21, and the third rubber ring G3 and the outer periphery of the inner joint body 22 are slid, thereby fitting the inner joint body 22 into the outer joint body 21. The inner diameter of the opening of the outer joint body 21 on the side where the inner joint body 22 is inserted is formed to be smaller than the outer diameter of the inner joint body 22. The opening of the outer joint body 21 on the side where the inner joint body 22 is inserted has a cutout portion 21h, such as Fig. 22 As shown in the lower side of (B), the inner joint body 22 in the insertion posture can be freely inserted into the inner part of the outer joint body 21. The cutout portion 21h is formed at two radially opposite locations in the inner joint body 22, and the upper end and the lower end of the inner joint body 22 in the insertion posture can be freely passed through. So, like Fig. 22 As shown in (B), when the inner joint body 22 in the insertion posture is inserted through the cutout portion 22e to the inside of the outer joint body 21, the posture of the inner joint body 22 in the insertion posture is transformed into the installation posture inside the outer joint body 21, and its axial direction is consistent with the tube axial direction of the outer joint body 21. Fig. 22 In (B), the inner joint body 22 in the insertion posture is indicated by a dashed line, and the inner joint body 22 after the posture is changed to the mounting posture is indicated by a solid line. During the cannula insertion process, Fig.23As shown in (A), in the state where the fourth rubber ring G4 is installed in the sealing installation groove 22d of the inner joint body 22, a proper amount of lubricant is applied to the outer periphery of the fourth rubber ring G4 and the second sleeve 105, so that the fourth rubber ring G4 and the outer periphery of the second sleeve 105 slide, thereby embedding the second sleeve 105 in the inner joint body 22. It should be noted that a rubber cover 109 is connected to the outer periphery of the second sleeve 105, and the cover 109 is connected to the outer periphery of the outer joint body 21 of the second joint part 102, as shown in FIG. Fig.14 As shown, the cover body 109 is installed in a state of covering the connection portion between the second joint part 102 and the second sleeve 105 and the like. During the locking ring installation process, Fig.23 As shown in (B) in the figure, the second locking ring R2 is installed in the locking ring installation groove 51a of the joint side connection part 51 of the second sleeve 105 inserted into the inner joint body 22. The installation tool 810 is inserted into the inner joint body 22 from the end openings of the outer joint body 21 and the inner joint body 22 of the second joint part 102 in the axial direction of the pipe. Fig.21 The same as (A) in FIG. 1 is to engage the installation tool 810 in the engagement hole R2a of the second locking ring R2 (see Fig. 22 In (A)), the second locking ring R2 is expanded by overcoming the elastic restoring force, and the second locking ring R2 is moved in (moved) to a position corresponding to the locking ring mounting groove 51a of the second sleeve 105, and the expansion operation force is released, so that the second locking ring R2 is reduced in diameter due to the elastic restoring force and is embedded and retained in the locking ring mounting groove 51a. Thus, in the second connection step, by Fig. 22 The locking ring insertion process shown in (A) Fig. 22 The inner joint body installation process shown in (B) Fig.23 The cannula insertion step shown in (A) and Fig.23 The locking ring installation process shown in (B) is as follows: Fig.24 As shown in (A) in the figure, the joint-side connecting portion 51 of the second sleeve 105 is embedded in the second joint portion 102, thereby connecting the second sleeve 105 to the second joint portion 102. The first connection process is omitted in the figure, but is the same as the second connection process, by performing the locking ring insertion process, the inner joint body installation process, the sleeve insertion process, and the locking ring installation process. Fig.24 As shown in (B) in the figure, the joint-side connecting portion 41 of the first sleeve 104 is embedded in the first joint portion 101, thereby connecting the first sleeve 104 to the first joint portion 101. As described above, in this embodiment, by performing the first to fourth steps in sequence, the sealing function of the fifth rubber ring G between the first sleeve 104 and the second sleeve 105 is properly ensured, and not only can the third locking ring R3 be inserted into the second sleeve 105, but also the setting operation of the third locking ring R3 can be simplified, and the telescopic pipe joint 100 can be assembled in an orderly manner in a suitable manner. [Other implementation methods] Other embodiments of the invention of this reference example will be described. It should be noted that the configuration of each embodiment described below is not limited to being used alone, and can also be used in combination with the configuration of other embodiments. (1) In the above embodiment, the enlarged diameter portion 54 is formed in the second sleeve 105 from a position adjacent to the fitting portion 53 in the tube axial direction, and the width of the third movement-allowing space K3 of the second sleeve 105 in the radial direction is substantially the same width regardless of the formation position of the moving-in operation space 61. Alternatively, for example, the enlarged diameter portion may be formed from a position away from the fitting portion 53 in the tube axial direction, and the width of the third movement-allowing space K3 of the second sleeve 105 in the radial direction may be changed. The width of the third radial allowable movement space K3 of the second sleeve 105 can be changed according to the formation position of the moving-in operation space 61. For example, the width of the portion that is more deviated from the side where the interlocking portion 53 is located than the moving-in operation space 61 is made narrower, and the width of the portion corresponding to the formation position of the moving-in operation space 61 is made wider. (2) In the above embodiment, in the second sleeve 105, the connecting portion 58 connecting the enlarged diameter portion 54 and the reduced diameter portion 55 is inclined so as to gradually reduce the diameter in the axial direction of the tube. For example, the connecting portion may be a straight connecting portion extending in the radial direction of the second sleeve 105 (extending in a direction orthogonal to the axial direction of the tube). (3) In the above embodiment, as the method for assembling the expansion pipe joint 100, an example is shown in which the second connecting step is performed first and then the first connecting step in the fourth step. However, the first connecting step may be performed first and then the second connecting step. The order in which the steps of the assembly method of the expansion pipe joint 100 are performed can be changed appropriately. For example, the first connection step in the fourth step may be performed first, then the third step, and then the second connection step in the fourth step. Description of Reference Numerals 1: The first tube body; 2: Second tube body; 4: Locking ring; 5: Shell; 6: Intermediate casing; 8: Temporary fixing fixture; 10: Telescopic pipe joint; 45: segmentation; 48: assembly; 65: incision; 80: Main body; 81: first protrusion; 82: second protrusion; D1: insertion direction; D2: Disengagement direction.

Claims

1. An assembly method of a telescopic pipe joint, in which a first pipe body and a second pipe body inserted into the first pipe body are connected so as to be relatively movable within a certain range along an axial direction, and a locking ring installed on the outer peripheral surface of the second pipe body plays a role in preventing separation, the assembly method of the telescopic pipe joint is characterized by comprising: A temporary fixing step, embedding an assembly into the first tube, wherein the assembly is formed by assembling the locking ring, which is expanded in diameter by elastic deformation, on a temporary fixing fixture, and holding the locking ring in the expanded state in a coaxial posture with the first tube; as well as The installation process includes inserting the second tube body into the locking ring in the expanded state, removing the temporary fixing fixture from the locking ring by inserting and moving the second tube body, and installing the locking ring on the outer peripheral surface of the second tube body.

2. The method for assembling a telescopic pipe joint according to claim 1, wherein: The locking ring has a dividing portion for dividing the locking ring in a circumferential direction. The temporary fixing fixture comprises: a main body portion formed to be embedded in the first tube body; and a first protrusion protruding from the main body, In the temporary fixing step, the first protrusion is inserted into the divided portion whose gap is enlarged by elastic deformation, so that the lock ring is maintained in the expanded diameter state.

3. The method for assembling a telescopic pipe joint according to claim 1, wherein: The temporary fixing jig comprises: a main body portion formed to be embedded in the first tube body; and a second protrusion portion protruding from the main body portion. In the temporary fixing step, the lock ring is mounted on the temporary fixing jig in a state of being abutted against the second protrusion.

4. The method for assembling a telescopic pipe joint according to claim 1, wherein: In the installation process, the locking ring is engaged with the engaged portion formed inside the first tube in the insertion direction of the second tube. In the engaged state, the temporary fixing fixture is pressed by the second tube to remove the temporary fixing fixture from the locking ring.

5. The method for assembling a telescopic pipe joint according to any one of claims 1 to 4, wherein: The first tube body comprises: an outer shell, comprising a spherical inner peripheral surface; and an intermediate sleeve, comprising a spherical outer peripheral surface, wherein the spherical outer peripheral surface and the spherical inner peripheral surface can be relatively freely slidably engaged. In the temporary fixing process, the assembly is embedded in the intermediate sleeve.

6. The method for assembling a telescopic pipe joint according to claim 5, wherein: A cutout is formed in the intermediate sleeve, and the cutout allows the locking ring to pass through the intermediate sleeve in a posture where the axial direction and radial direction of the intermediate sleeve are consistent. In the temporary fixing step, the temporary fixing jig is fitted into the cutout portion.

7. A temporary fixing structure of a locking ring, used for assembling a telescopic pipe joint, in which a first pipe body and a second pipe body inserted into the first pipe body are connected to each other so as to be relatively movable within a certain range along the axial direction, and a locking ring installed on the outer peripheral surface of the second pipe body plays a role in preventing separation, wherein the temporary fixing structure is characterized in that it is configured as follows: The assembly is embedded in the first tube body, and the assembly is formed by assembling the locking ring, which is expanded by elastic deformation, on a temporary fixing fixture, and the locking ring in the expanded state is maintained in a coaxial posture with the first tube body. When the second tube body is inserted into the locking ring in the expanded state, the temporary fixing jig is removed from the locking ring by the insertion and movement of the second tube body, so that the locking ring is installed on the outer peripheral surface of the second tube body.

8. The temporary fixing structure of the locking ring according to claim 7, wherein: The locking ring has a dividing portion for dividing the locking ring in a circumferential direction. The temporary fixing fixture comprises: a main body portion formed to be embedded in the first tube body; and a first protrusion protruding from the main body, The first protrusion is inserted into the divided portion whose gap is enlarged by elastic deformation, so that the lock ring is maintained in an expanded diameter state.

9. The temporary fixing structure of the locking ring according to claim 7, wherein: The temporary fixing jig comprises: a main body portion formed to be embedded in the first tube body; and a second protrusion portion protruding from the main body portion. The locking ring is mounted on the temporary fixing jig in a state of being abutted against the second protrusion.

10. The temporary fixing structure of the locking ring according to claim 7, wherein: An engaged portion is formed inside the first tube, and the locking ring in the expanded diameter state is opposite to the engaged portion in the insertion direction of the second tube.

11. The temporary fixing structure of the locking ring according to any one of claims 7 to 10, wherein: The first tube body comprises: an outer shell, comprising a spherical inner peripheral surface; and an intermediate sleeve, comprising a spherical outer peripheral surface, wherein the spherical outer peripheral surface and the spherical inner peripheral surface can be relatively freely slidably engaged. The assembly is embedded in the intermediate sleeve.

12. The temporary fixing structure of the locking ring according to claim 11, wherein: A cutout is formed in the intermediate sleeve, and the cutout allows the locking ring to pass through the intermediate sleeve in a posture where the axial direction and radial direction of the intermediate sleeve are consistent. The temporary fixing jig is embedded in the cutout portion.

Images