Pipe joint detachment prevention device and pipe joint detachment prevention structure

Abstract

The present invention provides a pipe joint detachment prevention device and detachment prevention structure that can provide a detachment prevention function even when a joint ring is used that does not have engagement points such as stepped sections or connecting points such as flanges. [Solution] The pipe joint 10, which is formed by externally fitting a joint ring 9 between a first Socket 1 and a second Socket 3 facing each other in the pipe axis direction, has a first retaining fitting 5 externally fitted to the first Socket 1, a second retaining fitting 6 externally fitted to the second Socket 2, and an intermediate fitting 7 positioned on the outer side of the joint ring 9 in the pipe diameter direction. The first retaining fitting 5 and the second retaining fitting 6 each have locking members 51 and 61 that can be locked to the outer surface of the pipe. The first retaining fitting 5 and the second retaining fitting 6 are engaged or connected to each other via the intermediate fitting 7 so that relative movement between the first retaining fitting 5 and the second retaining fitting 6 in the pipe axis direction is restricted when a detachment force is applied that causes the first Socket 1 or the second Socket 2 to detach from the joint ring 9.

Description

[[Technical Field]]

[0001] The present disclosure relates to a detachment prevention device and a detachment prevention structure for pipe joints. [[Background Art]]

[0002] Patent Document 1 describes a device for preventing detachment of a pipe joint. According to this device, the detachment prevention function is exerted when a detachment force that separates the socket part and the spigot part inserted into the socket part acts. This device is provided with a mechanism that engages with a stepped part provided on the socket part of a pipe, and it is assumed that the pipe joint to which the device is attached is of a type where the socket part has a stepped part, such as T-type, NS-type, or GX-type. Similar devices are also described in FIG. 10 of Patent Document 2 and Patent Document 3.

[0003] Patent Document 4 describes a device for preventing detachment of a pipe joint formed by connecting spigot parts to each other. The device includes an annular spigot ring externally fitted onto the spigot parts, and a lock ring locked to the outer peripheral surface of the pipe. In this pipe joint, a joint ring having flanges formed at both ends is used, and the spigot ring is connected via bolts and nuts attached to the flanges. Between the spigot ring and the joint ring, a pressing means having a pressing ring capable of pressing a sealing material mounted on the joint ring is disposed. [[Prior Art Documents]] [[Patent Documents]]

[0004] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2009-85376 [[Patent Document 2]] Japanese Unexamined Patent Publication No. 2010-261480 [[Patent Document 3]] Japanese Unexamined Patent Publication No. 2018-71762 [[Patent Document 4]] Japanese Unexamined Patent Publication No. 2016-156479 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0005] Incidentally, some joint rings used in pipe fittings that connect two Sockets do not have engagement points such as the stepped portion or connecting points such as the flange. In such cases, the above-mentioned device cannot be attached, and therefore the detachment prevention function cannot be performed.

[0006] This disclosure has been made in view of the above circumstances, and its purpose is to provide a pipe joint detachment prevention device and detachment prevention structure that can exhibit a detachment prevention function even when a joint ring is used that does not have engagement points such as stepped portions or connecting points such as flanges. [Means for solving the problem]

[0007] The pipe joint detachment prevention device of the present disclosure is a pipe joint detachment prevention device comprising a joint ring fitted externally between a first piton and a second piton that are opposite to each other in the pipe axial direction, and comprising a first retaining fitting fitted externally to the first piton, a second retaining fitting fitted externally to the second piton, and an intermediate fitting arranged on the outer side of the joint ring in the pipe radial direction. The first retaining fitting and the second retaining fitting each have a locking member that can be locked to the outer surface of the pipe. The first retaining fitting and the second retaining fitting are engaged or connected to each other via the intermediate fitting so as to restrict relative movement between them in the pipe axial direction when a detachment force is applied that causes the first piton or the second piton to detach from the joint ring.

[0008] The pipe joint detachment prevention structure of the present disclosure is a pipe joint in which the connecting ring is fitted externally between the first insertion portion and the second insertion portion, and the above-mentioned detachment prevention device is attached to the pipe joint. [Brief explanation of the drawing]

[0009] [Figure 1] Perspective view showing an example of a pipe joint detachment prevention structure related to this disclosure. [Figure 2] Side view of the detachment prevention structure shown in Figure 1. [Figure 3] Cross-sectional view taken along arrow AA in Figure 2 [Figure 4] Cross-sectional view taken along arrow BB in Figure 3. [Figure 5] (A) Plan view, (B) Front view section, and (C) DD line view showing the segmented pieces of the intermediate fitting. [Figure 6] Cross-sectional view showing the pipe joint detachment prevention structure in a modified example. [Figure 7] Cross-sectional view showing a pipe joint detachment prevention structure for another modified example. [Figure 8] A cross-sectional view showing a pipe joint detachment prevention structure related to yet another modified example. [Modes for carrying out the invention]

[0010] One embodiment of this disclosure will be described with reference to the drawings.

[0011] Figure 1 is a perspective view showing an example of a pipe joint detachment prevention structure according to this disclosure. Figure 2 is a side view of the detachment prevention structure. Figure 3 is a cross-sectional view taken along the arrow AA in Figure 2, where the intermediate fitting 7 is shown in a front view along the pipe axis direction. Figure 4 is a cross-sectional view taken along the arrow BB in Figure 3. In this pipe joint detachment prevention structure, a detachment prevention device 4 is attached to a pipe joint 10, which is formed by externally fitting a connecting ring 9 between a first spigot 1 (hereinafter referred to as spigot 1) and a second spigot 2 (hereinafter referred to as spigot 2) that face each other in the pipe axis direction. The detachment prevention device 4 is configured to prevent detachment when an external force (detachment force) acts on the connecting ring 9 to detach the spigot 1 or spigot 2.

[0012] The Socket 1 is formed at the end of the first pipe P1 (hereinafter referred to as pipe P1) on one side AD1 in the pipe axis direction. The Socket 1 is inserted into the joint ring 9, and the gap between them is sealed by an annular sealant 31. The AD1 on one side in the pipe axis direction corresponds to the direction in which the Socket 1 is inserted into the joint ring 9 (right direction in Figure 2). The Socket 2 is formed at the end of the second pipe P2 (hereinafter referred to as pipe P2) on the other side AD2 in the pipe axis direction. The Socket 2 is inserted into the joint ring 9, and the gap between them is sealed by an annular sealant 32. The AD2 on the other side in the pipe axis direction corresponds to the direction in which the Socket 2 is inserted into the joint ring 9 (left direction in Figure 2). Stoppers 11 and 21 are provided on the outer circumferential surfaces of the Socket 1 and Socket 2, respectively, facing the end face of the joint ring 9.

[0013] Pipe P1 is connected to pipe P2 in a sealed state via a connecting ring 9 and sealing materials 31 and 32. Pipes P1 and P2 are water pipes used as fluid pipes, but are not limited to these; they may also be fluid pipes used for fluids other than water, such as gas pipes or plant piping, or pipes containing gases. Furthermore, pipes P1 and P2 are made of metal, more specifically ductile cast iron, but are not limited to this. The connecting ring 9 and the intermediate fitting 7, which will be described later, are also made of ductile cast iron, but are not limited to this. In this embodiment, an example is shown in which the nominal diameters of pipes P1 and P2 are 800 mm, but it goes without saying that the embodiment is not limited to this.

[0014] In this embodiment, the joint ring 9 has a cylindrical outer surface that extends smoothly from the outer edge of AD1 on one side in the pipe axial direction to the outer edge of AD2 on the other side in the pipe axial direction. Here, "smoothly extended" means that it does not include steps or flanges that are intentionally provided in the design, but it may include minor roughness caused during casting or irregularities caused by the properties of the cast surface. The outer diameter of the joint ring 9 is substantially constant between the pair of outer edges. Many pipe fittings used in ductile cast iron pipes are standardized, and standardized pipe fittings that use such a joint ring 9 include U-shaped and UF-shaped fittings.

[0015] In the present embodiment, the pipe joint 10 is configured using spigot portions 1 and 2 of a U-shaped joint structure used for jacking methods, piping in shield tunnels, and the like. For this type of pipe joint, for example, pipes with a nominal diameter of 800 to 2600 mm are used. An annular accommodation space 93 is formed on the inner peripheral surface of the joint ring 9. The accommodation space 93 has accommodation portions 93a and 93b each having a wedge-shaped cross section whose inner diameter decreases toward each of both ends of the joint ring 9. The sealing material 31 accommodated in the accommodation portion 93a is compressed between the outer peripheral surface of the spigot portion 1 and the inner peripheral surface of the joint ring 9, and seals the gap therebetween. Similarly, the sealing material 32 accommodated in the accommodation portion 93b is compressed between the outer peripheral surface of the spigot portion 2 and the inner peripheral surface of the joint ring 9, and seals the gap therebetween. In addition to the sealing materials 31 and 32, split rings, pressing rings, bolts, and the like are also installed in the accommodation space 93, but illustration of these is omitted.

[0016] The detachment prevention device 4 includes a first retaining fitting 5 (hereinafter referred to as retaining fitting 5) externally fitted and attached to the spigot portion 1, a second retaining fitting 6 (hereinafter referred to as retaining fitting 6) externally fitted and attached to the spigot portion 2, and an intermediate fitting 7 arranged on the outer side of the joint ring 9 in the pipe diameter direction. The retaining fitting 5 and the retaining fitting 6 respectively have locking members 51 and 61 that can be locked to the outer peripheral surface of the pipe. When a detachment force that detaches the spigot portion 1 or the spigot portion 2 from the joint ring 9 acts, the retaining fitting 5 and the retaining fitting 6 are engaged or connected (engaged in the present embodiment) with each other via the intermediate fitting 7 such that relative movement of the retaining fitting 5 and the retaining fitting 6 in the pipe axial direction is restricted. Thereby, the detachment prevention function can be exerted in the pipe joint 10 using the joint ring 9 that does not have an engaging portion such as a stepped portion or a connecting portion such as a flange.

[0017] The pull-out prevention fitting 5 is formed of an annular member that is fitted over the spigot portion 1. As shown in Fig. 3, the pull-out prevention fitting 5 has a split structure formed by annularly connecting a plurality of split pieces, and is configured to be externally fittable onto an existing pipe. In the present embodiment, the pull-out prevention fitting 5 is composed of five split pieces 5A to 5E, but the number of splits can be appropriately changed depending on the application, size, and the like. The split pieces 5A to 5E each have the same shape as each other, and each of them holds a locking member 51. Adjacent split pieces are connected to each other by a connecting member 50 composed of a bolt and a nut. The pull-out prevention fitting 5 is neither engaged nor connected to the joint ring 9.

[0018] The pull-out prevention fitting 5 further comprises an accommodation groove 52 that accommodates the locking member 51, and a pressing bolt 53 serving as a pressing member capable of pressing the locking member 51 accommodated in the accommodation groove 52 toward the inner side in the pipe diameter direction. The locking member 51 is arranged on the opposite side to the side where the joint ring 9 is located (the other side AD2 in the pipe axial direction) with respect to the stopper 11. The locking member 51 is provided with a claw protruding toward the inner side in the pipe diameter direction. The claw is curved in an arc shape along the pipe circumferential direction, and is formed so as to be capable of biting into the outer peripheral surface of the pipe. On the outer peripheral surface of the locking member 51 with which the tip end of the pressing bolt 53 abuts, an inclined surface having a larger diameter toward the joint ring 9 is formed. For this reason, when a detachment force acts, a wedge effect is exerted, and the locking action of the locking member 51 is enhanced.

[0019] In the present embodiment, the pull-out prevention fitting 6 has the same configuration as the pull-out prevention fitting 5, so redundant description is omitted. The above description regarding the connecting member 50, locking member 51, accommodation groove 52 and pressing bolt 53 of the pull-out prevention fitting 5 also applies to the connecting member 60, locking member 61, accommodation groove 62 and pressing bolt 63 of the pull-out prevention fitting 6, respectively. The pull-out prevention fitting 6 can also have all of the configuration and functions of the pull-out prevention fitting 5 described hereinafter. Note that the pull-out prevention fitting 5 and the pull-out prevention fitting 6 may have configurations different from each other.

[0020] In this embodiment, the intermediate fitting 7 is formed by a cylindrical body that is fitted onto the connecting ring 9. The intermediate fitting 7 is positioned between the retaining fitting 5 and the retaining fitting 6. The retaining fitting 5 is engaged with the retaining fitting 6 via the intermediate fitting 7. By interposing the intermediate fitting 7, the retaining fittings 5 ​​and 6 can be engaged (or connected) to each other while maintaining a compact configuration. In this embodiment, the length of the intermediate fitting 7 in the pipe axis direction is smaller than the length of the connecting ring 9, but is not limited to this. The intermediate fitting 7 has a cylindrical inner surface that extends smoothly from the inner edge of one side AD1 in the pipe axis direction to the inner edge of the other side AD2 in the pipe axis direction. The inner diameter of the intermediate fitting 7 is substantially constant between the pair of inner edges.

[0021] The intermediate fitting 7 has a protrusion 71 that projects outward in the diameter direction of the pipe. At least one (both in this embodiment) of the retaining fitting 5 and the retaining fitting 6 has hooks 54, 64 that can engage with the protrusion 71 in the axial direction of the pipe when a release force is applied. When a release force is applied, the hooks 54, 64 engage with the protrusion 71, and consequently the retaining fitting 5 and the retaining fitting 6 engage with each other via the intermediate fitting 7, thereby providing a release prevention function. The outer diameter of the protrusion 71 is larger than the inner diameter of the tip of the hook 54, 64. The hooks 54, 64 are provided at multiple locations in the circumferential direction of the pipe, and are arranged so as to overlap the protrusion 71. Although not adopted in this embodiment to reduce weight, a structure in which the tips of adjacent hooks in the circumferential direction of the pipe are connected to each other may be used.

[0022] When attaching the detachment prevention device 4 to the pipe joint 10, the intermediate fitting 7 is fitted onto the connecting ring 9 which is installed between the insertion portion 1 and the insertion portion 2. Then, the retaining fitting 5 is attached so as to overlap one end of the intermediate fitting 7, and the retaining fitting 6 is attached so as to overlap the other end of the intermediate fitting 7. In this embodiment, the engagement between the retaining fitting 5 and the intermediate fitting 7, and the engagement between the retaining fitting 6 and the intermediate fitting 7, are both metal-to-metal contact, and there is no need to torque-control these engagement forces, thus reducing variations in performance due to the operator.

[0023] The intermediate fitting 7 is provided with a load-receiving surface 72 that receives the load from the hooks 54 and 64 when a detachment force is applied. The load-receiving surface 72 is included in the side surface of the convex portion 71 facing the center in the pipe axis direction of the intermediate fitting 7. In this embodiment, the load-receiving surface 72 is provided on the outer side in the pipe diameter direction of the joint ring 9, as shown in Figure 4. This allows the retaining fittings 5 ​​and 6 to be positioned close to the joint ring 9, making the overall length of the detachment prevention device 4 more compact. Therefore, for example, at a construction site where the detachment prevention device 4 is attached to the pipe joint 10, it is convenient to avoid interference between the detachment prevention device 4 and obstacles around the pipe joint 10.

[0024] The intermediate fitting 7 is formed by an annular member that is fitted over the connecting ring 9. As shown in Figures 1 to 3, the intermediate fitting 7 has a split structure in which a plurality of segmented pieces are connected in an annular shape. In this embodiment, the intermediate fitting 7 is composed of two segmented pieces 7A and 7B, but the number of segments can be changed as appropriate depending on the application and size. Figure 5 is (A) a plan view, (B) a partial front view section along the CC arrow, and (C) a cross-sectional view along the DD arrow of segmented piece 7A. The cross-sectional view along the EE arrow is omitted as it can be seen in Figure 4. The shape of segmented piece 5B is the same as segmented piece 5A. Adjacent segmented pieces are connected to each other by a connector 70 composed of bolts and nuts.

[0025] The intermediate fitting 7 is provided with multiple dividing sections 7s (two in this embodiment) that divide the intermediate fitting 7 in the circumferential direction of the pipe, and a flange-shaped boss section 73 is formed on each of them. The boss section 73 is provided in a position that interferes with the hooks 54 and 64 in the circumferential direction of the pipe (see Figure 4), but is not limited to this. For example, a part of the boss section 73 may be cut out so as not to interfere with the hooks 54 and 64 in the circumferential direction of the pipe. With this configuration, the intermediate fitting 7 can be rotated along the circumferential direction of the pipe even when the retaining fittings 5 ​​and 6 are attached. Therefore, if there is an obstacle around the pipe joint 10 that interferes with the boss section 73, it is possible to avoid interference with the obstacle by rotating the intermediate fitting 7 to adjust the position of the boss section 73.

[0026] In the illustrated example, the anti-detachment device 4 is installed with the hook 54 in contact with the protrusion 71 (the load-receiving surface 72), but it is not limited to this, and the hook 54 may be separated from the protrusion 71. In that case, when the insertion portion 1 attempts to come out of the joint ring 9 due to the action of the detachment force, the hook 54 moves relative to it and engages with the protrusion 71, thereby providing the anti-detachment function. The amount of movement of the hook 54 at that time becomes the expansion and contraction range of the pipe joint 10, so by utilizing this engagement of the hook 54, the pipe joint 10 can be given an expansion and contraction function and its seismic resistance can be improved. The same applies to the hook 64 of the retaining fitting 6.

[0027] In this embodiment, the intermediate fitting 7 is provided with a fastening member 74 that protrudes from the inner circumferential surface of the intermediate fitting 7 and can be locked onto the outer circumferential surface of the connecting ring 9 (see Figure 2). With this configuration, when attaching the intermediate fitting 7 to the pipe joint 10, misalignment of the intermediate fitting 7 with respect to the connecting ring 9 can be suppressed, thereby improving workability. The fastening member 74 is a screw member that is attached to a through hole 75 (see Figure 5) formed in the intermediate fitting 7, and its protrusion amount is adjustable. Multiple through holes 75 are formed in the circumferential direction of the pipe. The tip of the fastening member 74 may be provided with a claw that protrudes inward in the diameter direction of the pipe.

[0028] The outer circumferential surface of the intermediate fitting 7 is provided with reinforcing ribs 76 that contribute to improving the strength of the intermediate fitting 7. The reinforcing ribs 76 include reinforcing ribs 76a extending in the circumferential direction of the pipe and reinforcing ribs 76b extending in the axial direction of the pipe, intersecting with the reinforcing ribs 76a. The through hole 75 is formed on the reinforcing rib 76 (reinforcing rib 76b). At both ends of the intermediate fitting 7 in the axial direction of the pipe, protrusions 71 extending along the circumferential direction of the pipe are provided, and these also function as reinforcing ribs 76b. Therefore, the intermediate fitting 7 consists of reinforcing ribs 76a provided at three locations in the axial direction of the pipe (center and both ends) and divided piece 7A It has a reinforcing rib 76b provided in the center of the circumferential direction of the pipe (or divided piece 7B).

[0029] Modified examples of pipe joint detachment prevention devices and detachment prevention structures will be described with reference to Figures 6-8. Components already described will be denoted by the same reference numerals, and redundant explanations will be omitted.

[0030] Figure 6 is a cross-sectional view showing a modified pipe joint detachment prevention structure. Figures 6(A) and (B) show cross-sections at different positions in the circumferential direction of the pipe. In the above-described embodiment, an example was shown in which the hook 54 is formed from a component constituting the main body 55 that holds the locking member 51, but the invention is not limited to this. For example, as shown in Figure 6, the hook 54 may be formed from a component separate from the main body 55. The hook 54 and the main body 55 are connected and fixed to each other by a connector 56 consisting of a bolt and a nut. The same applies to the retaining clip 6, in this example, where the hook 64, formed from a component separate from the main body 65, is connected and fixed to the main body 65 by the connector 66.

[0031] Figure 7 is a cross-sectional view showing a pipe joint detachment prevention structure according to another modified example. Figures 7(A) and (B) show cross-sections at different positions in the circumferential direction of the pipe. The intermediate fitting 7 shown in Figure 7 has a flange 77 as a mounting portion to which connectors 56 and 66 are attached, and at least one (both in this embodiment) of the retaining fitting 5 and retaining fitting 6 is connected to the flange 77. In this way, the retaining fitting 5 and the retaining fitting 6 are connected to each other and are configured to restrict their relative movement in the axial direction of the pipe when a detachment force is applied. This enables the pipe joint 10 using a connecting ring 9 that does not have a step or flange to exhibit a detachment prevention function.

[0032] The flanges 77 are provided in pairs at both ends of the intermediate fitting 7. One flange is connected and fixed to the main body 55 of the retaining fitting 5 by a connector 56, and the other flange is connected and fixed to the main body 65 of the retaining fitting 6 by a connector 66. Such connecting and fixing parts are provided at multiple locations in the circumferential direction of the pipe. In this example, the length of the intermediate fitting 7 in the axial direction of the pipe is greater than the length of the connecting ring 9, but this is not limited to this. The same materials as in Figure 6 can be used for the main bodies 55 and 65. It is also possible to adopt the form in Figure 7 for one of the retaining fittings 5 ​​and 6, while adopting the form in Figure 4 or Figure 6 for the other.

[0033] Figure 8 is a cross-sectional view showing a pipe joint detachment prevention structure according to yet another modification. Figures 8(A) and (B) show cross-sections at different positions in the circumferential direction of the pipe. In the example shown in Figure 8, an intermediate fitting 8 is used, which is formed by an axial body extending from the retaining fitting 5 to the retaining fitting 6. The retaining fitting 5 and the retaining fitting 6 are connected to each other via the intermediate fitting 8, and are configured so that their relative movement in the axial direction of the pipe is restricted when a detachment force is applied. This enables a detachment prevention function to be achieved in a pipe joint 10 that uses a joint ring 9 without steps or flanges.

[0034] The intermediate fittings 8 are attached at multiple locations in the circumferential direction of the pipe. The intermediate fittings 8 are positioned to straddle the connecting ring 9 and are inserted through the main body 55 and the main body 65, respectively. The intermediate fittings 8 are made of threaded rods, with nuts 82 attached to both ends. The intermediate fittings 8 are inserted into cylindrical spacers 83 positioned between the retaining fittings 5 ​​and 6 to prevent the retaining fittings 5 ​​and 6 from moving due to the tightening of the nuts 82. The distance between the main body 55 and the main body 65 is defined by the spacers 83. The same materials as in Figure 6 can be used for the main body 55 and 65.

[0035] Those skilled in the art will understand that the embodiments described above are specific examples of the following embodiments.

[0036] [1] The pipe joint detachment prevention device of this disclosure is a pipe joint detachment prevention device comprising a joint ring fitted externally between a first piton and a second piton that are opposite to each other in the pipe axial direction, and comprises a first retaining fitting fitted externally to the first piton, a second retaining fitting fitted externally to the second piton, and an intermediate fitting arranged on the outer side of the joint ring in the pipe radial direction. The first retaining fitting and the second retaining fitting each have a locking member that can be locked to the outer surface of the pipe. The first retaining fitting and the second retaining fitting are engaged or connected to each other via the intermediate fitting so as to restrict relative movement between them in the pipe axial direction when a detachment force is applied that detaches the first piton or the second piton from the joint ring. With this configuration, the detachment prevention function can be performed even when a joint ring is used that does not have engagement points such as steps or connection points such as flanges.

[0037] [2] In the detachment prevention device described in [1] above, the intermediate fitting may be formed by a cylindrical body fitted onto the connecting ring. With this configuration, the first retaining fitting and the second retaining fitting can be made compact while still being able to engage or connect with each other.

[0038] [3] In the detachment prevention device described in [1] or [2] above, the intermediate fitting may have a protrusion that extends outward in the diameter direction of the pipe, and at least one of the first retaining fitting and the second retaining fitting may have a hook that can engage with the protrusion in the axial direction of the pipe when the detachment force is applied. When the detachment force is applied, the hook engages with the protrusion, and consequently the first retaining fitting and the second retaining fitting engage with each other via the intermediate fitting, thereby providing a detachment prevention function.

[0039] [4] In the detachment prevention device described in [3] above, the load-receiving surface that receives the load from the hook when the detachment force is applied may be provided on the outer side of the connecting ring in the diameter direction of the pipe. With this configuration, the first retaining fitting or the second retaining fitting can be positioned close to the connecting ring, so the overall length of the detachment prevention device becomes compact.

[0040] [5] In any one of the above [1] to [4] anti-detachment devices, the intermediate fitting may be provided with a fastening member that protrudes from the inner circumferential surface of the intermediate fitting and can be locked onto the outer circumferential surface of the connecting ring. With this configuration, when attaching the intermediate fitting to the pipe joint, misalignment of the intermediate fitting relative to the connecting ring can be suppressed, thereby improving workability.

[0041] [6] In any one of the above [1] to [5] anti-detachment devices, the intermediate fitting may have a mounting portion to which a connector is attached, and at least one of the first retaining fitting and the second retaining fitting may be connected to the mounting portion. With this configuration, the first retaining fitting and the second retaining fitting are connected to each other via the intermediate fitting, and their relative movement in the axial direction of the pipe is restricted when a detachment force is applied.

[0042] [7] In any one of the above [1] to [6] anti-detachment devices, the intermediate fitting may be formed by a shaft-like body extending from the first retaining fitting to the second retaining fitting, and the first retaining fitting and the second retaining fitting may be connected to each other via the intermediate fitting. With this configuration, the first retaining fitting and the second retaining fitting are connected to each other via the shaft member, and their relative movement in the axial direction of the pipe is restricted when a detachment force is applied.

[0043] [8] The pipe joint detachment prevention structure of the present disclosure is a pipe joint in which the connecting ring is fitted externally between the first insertion portion and the second insertion portion, and one of the above-mentioned detachment prevention devices [1] to [7] is attached to the pipe joint. With this configuration, the detachment prevention function can be performed even when a connecting ring that does not have engagement points such as steps or connecting points such as flanges is used.

[0044] [9] In the detachment prevention structure described in [8] above, the connecting ring may have a cylindrical outer surface that extends smoothly from the outer edge on one side in the pipe axis direction to the outer edge on the other side in the pipe axis direction. The detachment prevention function can be appropriately performed even in a pipe joint using such a connecting ring.

[0045] While embodiments of the pipe joint detachment prevention device and detachment prevention structure relating to this disclosure have been described with reference to the drawings, it should be understood that the specific configuration is not limited to these embodiments. The scope of this disclosure is indicated not only by the above-described embodiments but also by the claims, and furthermore, all modifications within the meaning and scope of equivalence to the claims.

[0046] The pipe joint detachment prevention device and detachment prevention structure described herein are not limited in any way to the embodiments described above, nor are they limited to the effects described above. The pipe joint detachment prevention device and detachment prevention structure described herein can be modified in various ways without departing from the spirit thereof. Furthermore, the various components adopted in the embodiments described above can be arbitrarily combined and adopted. [Explanation of Symbols]

[0047] 1 First insertion part, 2 Second insertion part, 4 Anti-detachment device, 5 First retaining fitting, 6 Second retaining fitting, 7 Intermediate fitting, 8 Intermediate fitting, 9 Joint ring, 10 Pipe joint, 31 Sealing material, 32 Sealing material, 51 Locking member, 54 Hook, 61 Locking member, 64 Hook, 71 Protrusion, 72 Load-receiving surface, 74 Retaining member, 77 Flange (example of mounting part), AD1 One side in the pipe axis direction, AD2 The other side in the pipe axis direction, P1 Pipe, P2 Pipe

Claims

1. A pipe joint detachment prevention device comprising a joint ring fitted externally between a first tubing portion and a second tubing portion that are opposite to each other in the pipe axis direction, The joint ring comprises a first retaining fitting fitted to the first insertion portion, a second retaining fitting fitted to the second insertion portion, and an intermediate fitting positioned on the outer side of the joint ring in the diameter direction of the pipe. The first retaining clip and the second retaining clip each have a locking member that can be locked to the outer surface of the pipe, A pipe joint detachment prevention device, wherein the first retaining fitting and the second retaining fitting are engaged or connected to each other via the intermediate fitting so as to restrict the relative movement of the first retaining fitting and the second retaining fitting in the pipe axis direction when a detachment force is applied that detaches the first or second detachment portion from the joint ring.

2. The pipe joint detachment prevention device according to claim 1, wherein the intermediate fitting is formed by a cylindrical body that is fitted onto the joint ring.

3. The aforementioned intermediate fitting has a protrusion that extends outward in the diameter direction of the pipe, The pipe joint detachment prevention device according to claim 1, wherein at least one of the first retaining fitting and the second retaining fitting has a hook that can engage with the protrusion in the pipe axis direction when the detachment force is applied.

4. The pipe joint detachment prevention device according to claim 3, wherein the load-receiving surface that receives the load from the hook when the aforementioned detachment force is applied is provided on the outer side of the joint ring in the pipe diameter direction.

5. The pipe joint detachment prevention device according to claim 1, wherein the intermediate fitting comprises a fastening member that protrudes from the inner circumferential surface of the intermediate fitting and can be locked to the outer circumferential surface of the joint ring.

6. The aforementioned intermediate fitting has a mounting portion to which a connector is attached, The pipe joint detachment prevention device according to claim 1, wherein at least one of the first retaining fitting and the second retaining fitting is connected to the mounting portion.

7. The intermediate fitting is formed by a shaft-like body extending from the first retaining fitting to the second retaining fitting. The pipe joint detachment prevention device according to claim 1, wherein the first retaining fitting and the second retaining fitting are connected to each other via the intermediate fitting.

8. A pipe joint detachment prevention structure, wherein the pipe joint is fitted with the connecting ring externally between the first insertion portion and the second insertion portion, and the detachment prevention device according to any one of claims 1 to 7 is attached to the pipe joint.

9. The pipe joint detachment prevention structure according to claim 8, wherein the joint ring has a cylindrical outer surface that extends smoothly from the outer edge on one side in the pipe axis direction to the outer edge on the other side in the pipe axis direction.

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