Pipe joint

Abstract

The pipe joint 1 has an insertion opening 3 formed in a first pipe 2, a socket opening 5 formed in a second pipe 4, a lock ring groove 7 formed in the inner periphery of the socket opening 5, a lock ring 8 housed in the lock ring housing groove 7, and an insertion opening engagement part 10 formed in the outer periphery of the insertion opening 3. The insertion opening (3) can be prevented from disengaging from the socket (5) by hooking the insertion opening engagement part (10) to the lock ring (8) in a state in which the insertion opening (3) is inserted into the socket (5). The socket (5) has, on the inner circumference thereof, an inner tapered surface (30) that expands in diameter from the inner end of the socket (5) toward the open end of the socket (5), and a bend angle restricting section (34) that protrudes inward in the pipe diameter direction from the inner circumference of the socket (5). The inner tapered surface (30) is formed between the lock ring housing groove (7) of the socket (5) and the inner end (26). The bending angle restricting section 34 prevents the first pipe 2 from bending beyond an allowable angle with respect to the second pipe 4.

Description

Technical Field

[0001] The present invention relates to a pipe joint having a function of preventing an insertion port from being separated from a receiving port. Background Art

[0002] Conventionally, as such pipe joints, for example Fig.18 As shown, there is a pipe joint 205 for inserting the insertion port 202 of the first pipe 201 into the socket 204 of the second pipe 203. A locking ring receiving groove 206 is formed on the inner periphery of the socket 204. A locking ring 207 is received in the locking ring receiving groove 206. An insertion port protrusion 208 is formed on the outer periphery of the insertion port 202. By making the insertion port protrusion 208 hook on the locking ring 207 from the inner side of the socket 204 in the disengagement direction 209 of the insertion port 202, it is possible to prevent the insertion port 202 from being disengaged from the socket 204.

[0003] The sealing member 210 that seals between the inner periphery of the socket 204 and the outer periphery of the insertion port 202 is inserted from the opening of the opening end surface 211 of the socket 204 between the inner periphery of the socket 204 and the outer periphery of the insertion port 202. The pressing ring 212 into which the sealing member 210 is pressed is connected to the socket 204 via bolts 213 and nuts 214.

[0004] The first tube 201 and the second tube 203 are ductile iron tubes cast by centrifugal casting, for example. In order to extract these tubes 201 and 203 from the centrifugal casting mold during centrifugal casting, the socket 204 has an outer tapered surface 216 on the outer periphery that gradually expands from the position of the inner end surface 215 of the socket 204 toward the position of the opening end surface 211.

[0005] The inner circumferential surface 217 of the socket 204 is parallel to the tube axis of the second tube 203 between the position near the locking ring receiving groove 206 in the tube axis direction 218 and the inner end surface 215 of the socket 204. Thus, the inner diameter d of the socket 204 is constant between the position near the locking ring receiving groove 206 and the inner end surface 215 of the socket 204.

[0006] Note that the above-mentioned pipe joint 205 can be referred to Japanese Patent Application Laid-Open No. 2022-74980. Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the above-mentioned conventional form, since the tube thickness T of the socket 204 gradually increases from the inner end surface 215 of the socket 204 to the locking ring receiving groove 206, there is the following problem: the weight of the socket 204 increases, and thereby, the weight of the entire tube also increases.

[0009] In addition, it is possible to reduce the weight of the socket 204 by increasing the inner diameter d of the socket 204 and reducing the tube thickness T of the socket 204. However, in this case, the tube thickness T near the inner end surface 215 of the socket 204 becomes too thin, and the strength of this part may be insufficient.

[0010] The object of the present invention is to provide a pipe joint capable of achieving lightweight receiving end.

[0011] Means for solving problems

[0012] The pipe joint of the present invention has:

[0013] an insertion port formed in the first tube;

[0014] A receiving port, the receiving port being formed on the second pipe;

[0015] A locking ring groove, the locking ring groove being formed on the inner circumference of the receiving interface;

[0016] a locking ring received in a locking ring receiving groove; and

[0017] an insertion port engaging portion, wherein the insertion port engaging portion is formed on the outer periphery of the insertion port,

[0018] When the insertion port is inserted into the socket, the insertion port engaging portion is hooked on the locking ring from the inner side of the socket in the disengagement direction of the insertion port, thereby preventing the insertion port from being disengaged from the socket. The invention is characterized in that:

[0019] The socket has an inner conical surface on the inner circumference that expands from the inner end of the socket toward the open end of the socket and a bending angle limiting portion that protrudes inward from the inner circumference of the socket in the pipe diameter direction.

[0020] The inner conical surface is formed between the locking ring receiving groove and the inner end of the socket.

[0021] The bending angle restricting portion prevents the first tube from bending relative to the second tube beyond a permissible angle.

[0022] Thus, since the socket has an inner tapered surface on the inner circumference that expands from the inner end of the socket toward the open end of the socket, the thickness of the pipe of the socket becomes thinner between the locking ring receiving groove and the inner end of the socket, compared with a socket having an inner circumferential surface parallel to the pipe axis. Thus, the socket can be made lighter. Moreover, by making the socket have the inner tapered surface as described above, the thickness of the pipe at the position of the inner end of the socket is kept at a sufficient thickness, and the strength of the inner end of the socket will not be insufficient.

[0023] The inner tapered surface of the socket increases the bending angle of the insertion port relative to the socket, thereby improving the bending performance of the first pipe and the second pipe. Thus, the first pipe and the second pipe can be fully bent according to the shaking during an earthquake, thereby preventing the pipes from being damaged.

[0024] In this way, although the bending performance of the first tube and the second tube is improved, if the first tube and the second tube are bent excessively, water leakage may occur between the insertion port and the socket. In such a case, the bending angle of the insertion port relative to the socket is limited to below the allowable angle by making the insertion port abut against the bending angle limiting portion of the socket. Therefore, the insertion port can be prevented from being bent excessively relative to the socket, and water leakage can be prevented from occurring between the insertion port and the socket.

[0025] According to the pipe joint of the present invention, preferably, the socket has an outer tapered surface on the outer periphery thereof, the diameter of which increases from the inner side of the socket toward the opening end of the socket.

[0026] As a result, the pipe thickness of the socket can be made substantially uniform between the lock ring receiving groove and the inner end of the socket.

[0027] According to the pipe joint of the present invention, preferably, a spacer for limiting movement of the insertion port in the insertion direction toward the socket is provided between the front end of the insertion port and the inner end of the socket.

[0028] At a position closer to the inner side of the receiving interface than the bending angle limiting portion, a centering surface is formed between the inner conical surface of the receiving interface and the inner end portion.

[0029] The spacer has a first centering contact portion in contact with the inner peripheral surface of the bending angle restricting portion and a second centering contact portion in contact with the centering surface.

[0030] Thus, by providing a spacer between the front end of the insertion port and the inner end of the socket, the movement of the insertion port in the insertion direction toward the socket is limited. In addition, by hooking the insertion port engaging portion on the locking ring, the movement of the insertion port in the disengagement direction is limited. Therefore, the relative movement of the insertion port and the socket in the pipe axis direction is limited. Therefore, in the portion where the uneven force acts on the pipeline, the movement of the pipe joint is limited, and the telescopic function between the insertion port and the socket and the bending function of the insertion port and the socket are limited. Thus, it is possible to prevent the pipeline from telescoping or bending in the direction of the uneven force, which would adversely affect the sealing performance of the pipe joint.

[0031] When the spacer is set inside the socket, the first centering contact portion of the spacer is connected to the inner peripheral surface of the bending angle limiting portion, and the second centering contact portion is connected to the centering surface. Therefore, the installation position of the spacer will not be offset in the pipe diameter direction, and the centering operation of the spacer relative to the socket can be easily performed.

[0032] According to the pipe joint of the present invention, preferably, the spacer has a cylindrical spacer body arranged between the front end of the insertion port and the inner end of the receiving port, and is divided into a plurality of arc-shaped divided pieces in the pipe circumferential direction.

[0033] The ends of the adjacent split pieces in the circumferential direction of the tube are connected to each other.

[0034] The first centering contact portion is provided at one end of the spacer body in the tube axis direction.

[0035] The second centering contact portion is provided at the other end of the spacer body in the tube axis direction.

[0036] A space is formed between the first centering contact portion and the second centering contact portion in the tube axis direction and between the outer peripheral surface and the inner tapered surface of the spacer body in the tube diameter direction.

[0037] The distance between the outer peripheral surface of the spacer body and the inner tapered surface in the pipe diameter direction increases as it approaches the opening end of the receiving port.

[0038] Thus, when the plurality of split pieces are arranged inside the receiving port and the spacer is assembled, a space is formed between the outer peripheral surface of the spacer body and the inner conical surface, so there is no worry that the operator's hand will be caught between the outer peripheral surface of the spacer body and the inner conical surface. Therefore, the safety and workability of the spacer assembly operation are improved.

[0039] Effects of the Invention

[0040] As described above, according to the present invention, since the socket has an inner tapered surface on the inner circumference that expands from the inner end of the socket toward the open end of the socket, the thickness of the socket becomes thinner between the locking ring receiving groove and the inner end of the socket, compared with a socket having an inner circumferential surface parallel to the pipe axis. As a result, the socket can be made lighter, and the entire pipe can be made lighter. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a cross-sectional view of the pipe joint in the first embodiment of the present invention, and shows a state where the insertion port is inserted into the socket with a normal insertion amount and the insertion port is not bent relative to the socket.

[0042] Figure 2 It is a cross-sectional view of the pipe joint in the first embodiment, and shows a state in which the insertion port is inserted into the socket with a normal insertion amount and the insertion port is bent relative to the socket.

[0043] Figure 3 yes Figure 2 A partial enlarged cross-sectional view of a pipe joint.

[0044] Figure 4 It is a cross-sectional view of the pipe joint in the first reference example of the present invention, and shows a state where the insertion port is inserted into the socket with a normal insertion amount and the insertion port is bent relative to the socket.

[0045] Figure 5 yes Figure 4 A partial enlarged cross-sectional view of a pipe joint.

[0046] Figure 6 It is a cross-sectional view of a pipe joint in a second reference example of the present invention, and shows a state where the insertion port is inserted into the socket with a normal insertion amount and the insertion port is bent relative to the socket.

[0047] Figure 7 It is a cross-sectional view of the pipe joint in the first embodiment, and shows a state in which the insertion port is inserted into the socket by a greater insertion amount than a normal insertion amount and the insertion port is bent relative to the socket.

[0048] Figure 8 yes Figure 7 A partial enlarged cross-sectional view of a pipe joint.

[0049] Fig. 9 It is a cross-sectional view of a pipe joint in a third reference example of the present invention, and shows a state where the insertion port is inserted into the socket by a greater insertion amount than a normal insertion amount and the insertion port is bent relative to the socket.

[0050] Fig.10 yes Fig. 9 A partial enlarged cross-sectional view of a pipe joint.

[0051] Fig.11 It is a cross-sectional view of the pipe joint in the first embodiment, and shows a state in which the insertion port is bent relative to the receiving port in a state in which the insertion port is moved in the disengagement direction and the insertion port protrusion is engaged with the lock ring.

[0052] Fig.12 It is a diagram of a pipeline including a pipe joint according to a second embodiment of the present invention.

[0053] Fig.13 It is a cross-sectional view of the pipe joint in the second embodiment.

[0054] Fig.14 yes Fig.13 A front view of a spacer provided in the pipe joint shown.

[0055] Fig.15 It is a figure which shows the procedure when assembling a spacer.

[0056] Fig.16 It is a figure which shows the procedure when assembling a spacer.

[0057] Fig.17 It is a figure which shows the procedure when assembling a spacer.

[0058] Fig.18 This is a cross-sectional view of a conventional pipe joint. DETAILED DESCRIPTION

[0059] Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First embodiment)

[0060] In a first embodiment, if Figure 1 As shown, the pipe joint 1 has an insertion port 3 formed in a first pipe 2 and a socket 5 formed in a second pipe 4, and the insertion port 3 is inserted into the socket 5. For example, ductile iron pipes are used for these pipes 2 and 4. These pipes 2 and 4 are manufactured by centrifugal casting.

[0061] The inner circumference of the socket 5 is formed with a lock ring receiving groove 7 and an inner wall portion 32 over the entire circumference. The inner wall portion 32 protrudes inwardly from the inner circumference of the socket 5 in the pipe diameter direction 12 and faces the inner side of the lock ring receiving groove 7.

[0062] The lock ring 8 is accommodated in the lock ring accommodation groove 7. The lock ring 8 is a ring of a single cut structure in which one portion along the circumferential direction is cut.

[0063] An insertion port protrusion 10 (an example of an insertion port engaging portion) is formed all around the outer periphery of the insertion port 3. The insertion port protrusion 10 is provided at a position retreated by a predetermined length from the front end of the insertion port 3 along the disengagement direction 6 of the insertion port 3. By hooking the insertion port protrusion 10 on the locking ring 8 from the inner side of the socket 5 in the disengagement direction 6 of the insertion port 3, the insertion port 3 can be prevented from being disengaged from the socket 5.

[0064] A seal ring 13 is provided at a position closer to the opening end of the socket 5 than the lock ring 8. The seal ring 13 is compressed in the pipe diameter direction 12 to seal between the outer peripheral surface of the insertion port 3 and the inner peripheral surface of the socket 5. The seal ring 13 is a rubber ring.

[0065] A pressure ring 15 is provided at the open end of the socket 5 to press the sealing ring 13 into the inner side of the socket 5. The pressure ring 15 has a contact portion 18 that contacts the open end face 17 of the socket 5 in the insertion direction 16 of the sealing ring 13, and is connected to the open end of the socket 5 by a plurality of bolts 20 and nuts 21.

[0066] A support ring 24 is provided between the lock ring 8 and the seal ring 13 in the pipe axial direction 23. The support ring 24 is a ring for maintaining the distance between the outer peripheral surface of the insertion port 3 and the inner peripheral surface of the socket 5 in the pipe diameter direction 12 at a predetermined size.

[0067] The socket 5 has an outer tapered surface 29 on the outer periphery, and the outer tapered surface 29 gradually expands from the inner end surface 26 (an example of the inner end) of the socket 5 toward the open end of the socket 5. The socket 5 has an inner tapered surface 30 on the inner periphery, and the inner tapered surface 30 gradually expands from the inner end surface 26 of the socket 5 toward the open end of the socket 5.

[0068] By forming the outer tapered surface 29 on the socket 5 , when the pipe 4 is pulled out from the centrifugal casting mold during centrifugal casting, the pipe 4 can be pulled out from the side where the socket 5 is formed.

[0069] The inner tapered surface 30 is formed between the inner wall portion 32 and the vicinity of the inner end surface 26 of the receiving port 5. The outer tapered surface 29 and the inner tapered surface 30 are inclined at the same angle and are parallel to each other.

[0070] The inner tapered surface 30 has a bending angle restricting portion 34 formed around the entire circumference thereof, protruding inwardly in the tube diameter direction 12 from the inner tapered surface 30. The bending angle restricting portion 34 prevents the first tube 2 from bending relative to the second tube 4 beyond a maximum allowable angle (eg, 7°).

[0071] The inner peripheral surface 34a of the bending angle limiting portion 34 is parallel to the tube axis 4a of the second tube 4 and is formed straight in the tube axis direction 23. The inner peripheral surface 34a has a predetermined radius centered on the tube axis 4a of the second tube 4. Figure 2 As shown, the diameter of the inner circumferential surface 34a is set so that when the insertion port 3 is inserted into the socket 5 with a normal insertion amount and bent, the outer circumferential surface of the front end portion of the insertion port 3 is connected to the inner circumferential surface 34a of the bending angle limiting portion 34, thereby limiting the bending angle α of the insertion port 3 relative to the socket 5 to below the maximum allowable angle.

[0072] In addition, a centering surface 36 having an inner diameter d2 which is the same as the inner diameter d1 of the bending angle limiting portion 34 is formed over the entire circumference between the inner tapered surface 30 and the inner end surface 26 of the socket 5 at a position closer to the inner side of the socket 5 than the bending angle limiting portion 34. The centering surface 36 is aligned with the tube axis 4a of the second tube 4 (see Figure 2 ) and are formed straight in the tube axis direction 23.

[0073] The insertion port 3 is inserted into the socket 5 with a normal insertion amount. In this case, the insertion port protrusion 10 is at substantially the same position as the bending angle restriction portion 34 of the socket 5 in the pipe axial direction 23 .

[0074] Next, the function of the above-mentioned structure will be described.

[0075] Since the outer conical surface 29 and the inner conical surface 30 of the socket 5 are inclined at the same angle and are parallel to each other, the pipe thickness T of the socket 5 becomes uniform between the inner wall portion 32 of the locking ring receiving groove 7 and the inner end surface 26 of the socket 5. As a result, the socket 5 has a pipe axis 4a (refer to Figure 2 ) is parallel to the inner circumferential surface of the second tube 4, the tube thickness T is thinner between the inner wall portion 32 of the locking ring receiving groove 7 and the bending angle limiting portion 34 and between the bending angle limiting portion 34 and the inner end surface 26 of the receiving port 5. Therefore, the receiving port 5 can be made lighter, and the tube as a whole is made lighter. In addition, the tube thickness T in the bending angle limiting portion 34 and the receiving port 5 have a tube axis 4a (refer to Figure 2 ) The tube thickness T is the same thickness when the inner circumferential surfaces are parallel.

[0076] When the insertion port 3 is bent relative to the socket 5 in a state where it is inserted into the socket 5, since the socket 5 has an inner tapered surface 30, the bending angle α of the insertion port 3 relative to the socket 5 (refer to Figure 2 ) increases, and the bending performance of the first tube 2 and the second tube 4 is improved. Thus, by fully bending the first tube 2 and the second tube 4 according to the shaking during an earthquake, it is possible to prevent the tubes 2 and 4 from being damaged.

[0077] Figure 2 , Figure 3 The state where the insertion port 3 is inserted into the socket 5 with a normal insertion amount and bent is shown. In this case, the bending angle α is limited to less than the maximum allowable angle by making the outer peripheral surface of the front end of the insertion port 3 contact the inner peripheral surface 34a of the bending angle limiting portion 34. As a result, the insertion port 3 can be prevented from being bent too much relative to the socket 5, so that the sealing function of the sealing ring 13 can be fully maintained, and water leakage from the outer peripheral surface of the insertion port 3 and the inner peripheral surface of the socket 5 can be prevented.

[0078] In contrast, as a first reference example, Figure 4 , Figure 5 The socket 5 of the pipe joint 101 shown does not have an inner tapered surface 30 on the inner circumference, but has an inner circumferential surface 102 parallel to the pipe axis 4a of the second pipe 4. Figure 4 , Figure 5 In the position of the front end of the insertion port 3, the diameter of the inner peripheral surface 102 of the receiving port 5 is larger than the inner peripheral surface 34a of the bending angle limiting portion 34 (refer to Figure 3 )Small.

[0079] Thus, when the insertion port 3 is inserted into the socket 5 with a normal insertion amount, when the insertion port 3 is bent relative to the socket 5, the insertion port protrusion 10 is in contact with the inner peripheral surface 102 of the socket 5. Therefore, the bending angle α1 of the insertion port 3 relative to the socket 5 is smaller than the above Figure 2 Thus, in the pipe joint 101 of the first reference example, the bending angle α of the pipe joint 1 is Figure 2 Compared with the pipe joint 1 of the first embodiment shown, the bending performance of the first pipe 2 and the second pipe 4 is inferior.

[0080] In addition, as a second reference example, Figure 6 The receiving portion 5 of the pipe joint 111 shown has an inner tapered surface 30 , but does not form a bending angle limiting portion 34 .

[0081] According to the second reference example, when the insertion port 3 is inserted into the socket 5 with a normal insertion amount, when the insertion port 3 is bent relative to the socket 5, the outer peripheral surface of the front end of the insertion port 3 is in contact with the inner tapered surface 30. Therefore, the bending angle α2 of the insertion port 3 relative to the socket 5 is sometimes greater than the above Figure 2 Therefore, in the pipe joint 111 of the second reference example, the insertion port 3 may be bent too much relative to the socket 5, thereby reducing the sealing function of the sealing ring 13 and causing water leakage between the outer peripheral surface of the insertion port 3 and the inner peripheral surface of the socket 5.

[0082] Furthermore, in the first embodiment shown Figure 2 , Figure 3 , the insertion port 3 is shown to be bent relative to the socket 5 when the insertion port 3 is inserted into the socket 5 with a normal insertion amount, but in the first embodiment shown Figure 7 , Figure 8 , a state where the insertion port 3 is bent relative to the socket 5 in a state where the insertion port 3 is inserted into the socket 5 by a greater insertion amount than a normal insertion amount is shown.

[0083] Thus, although the outer peripheral surface of the front end portion of the insertion port 3 is not in contact with the bending angle limiting portion 34, it is in contact with the inner tapered surface 30 at a position closer to the inner side of the receiving port 5 than the bending angle limiting portion 34. Since the inner tapered surface 30 is reduced in diameter as it moves toward the inner side of the receiving port 5, the bending angle α of the insertion port 3 relative to the receiving port 5 increases within a range below the maximum allowable angle, and the bending performance of the first tube 2 and the second tube 4 is improved.

[0084] In contrast, as a third reference example, Fig. 9 , Fig.10 The socket 5 of the pipe joint 101 shown does not have an inner tapered surface 30 on the inner circumference, but has an inner circumferential surface 102 parallel to the pipe axis 4a of the second pipe 4. Fig. 9 , Fig.10 In the contact portion between the insertion port protrusion 10 and the inner peripheral surface 102 of the receiving port 5, the diameter of the inner peripheral surface 102 of the receiving port 5 is larger than the inner peripheral surface 34a of the bending angle limiting portion 34 (refer to Figure 3 )Small.

[0085] Thus, when the insertion port 3 is inserted into the socket 5 with a larger insertion amount than the normal insertion amount and the insertion port 3 is bent relative to the socket 5, the insertion port protrusion 10 is in contact with the inner peripheral surface 102 of the socket 5. Therefore, the bending angle α3 of the insertion port 3 relative to the socket 5 is smaller than the above Figure 7 Thus, in the pipe joint 101 of the third reference example, the bending angle α of the pipe joint 1 is Figure 7 Compared with the pipe joint 1 in the first embodiment shown, the bending performance of the first pipe 2 and the second pipe 4 is inferior.

[0086] Furthermore, in the first embodiment shown Fig.11 In the embodiment, when the insertion port 3 is bent relative to the socket 5 while the insertion port protrusion 10 is engaged with the locking ring 8 while the insertion port 3 is moved in the disengagement direction 6, the outer periphery of the insertion port protrusion 10 abuts against the inner periphery of the inner wall portion 32. Therefore, the bending angle of the insertion port 3 relative to the socket 5 is maintained at a predetermined angle α4 below the maximum allowable angle. In this case, for the first and third reference examples described above, Figure 4 , Fig. 9 In the pipe joint 101 shown in FIG. 1 , which has an inner peripheral surface 102 instead of the inner tapered surface 30, the bending angle of the insertion port 3 relative to the receiving port 5 is also maintained at the same predetermined angle α4 as described above. Figure 6 For the pipe joint 111 having the inner tapered surface 30 shown but without the bending angle limiting portion 34, the bending angle of the insertion port 3 relative to the receiving port 5 is also maintained at the same predetermined angle α4 as described above.

[0087] In the first embodiment described above, if Figure 1 As shown, the centering surface 36 is formed between the inner tapered surface 30 and the inner end surface 26 of the receiving port 5 , but it is also possible to have a structure in which the centering surface 36 is not formed and the inner tapered surface 30 reaches the inner end surface 26 of the receiving port 5 . (Second embodiment)

[0088] The following is based on Figure 12~Figure 17 The second embodiment will be described. The same components as those described in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0089] like Fig.12As shown, a pipeline 51 formed by joining a plurality of pipes has a bend 52, and an uneven force 53 acts on the bend 52 due to the fluid pressure in the pipeline 51. A pipe joint 54 is provided in such a pipeline 51. In the pipe joint 54, the insertion port 3 of the first pipe 2 is inserted into the receiving port 5 of the second pipe 4, and the first pipe 2 and the second pipe 4 are joined.

[0090] like Fig.13 As shown, the pipe joint 54 is provided with a spacer 61 for limiting the movement of the insertion port 3 in the insertion direction. The spacer 61 comprises: a cylindrical spacer body 62, which is arranged between the front end of the insertion port 3 and the inner end surface 26 of the socket 5; a first centering contact portion 63, which is in contact with the inner peripheral surface 34a of the bending angle limiting portion 34; and a second centering contact portion 64, which is in contact with the centering surface 36 in the socket 5.

[0091] The first centering contact portion 63 is provided over the entire circumference at one end of the spacer body 62 in the tube axial direction 23. The second centering contact portion 64 is provided over the entire circumference at the other end of the spacer body 62 in the tube axial direction 23. The first centering contact portion 63 and the second centering contact portion 64 are circular members protruding from the outer peripheral surface of the spacer body 62 to the outside in the tube diameter direction 12.

[0092] A space 66 is formed over the entire circumference between the first centering contact portion 63 and the second centering contact portion 64 in the tube axial direction 23 and between the outer peripheral surface of the spacer body 62 and the inner tapered surface 30 in the tube diameter direction 12. The space S between the outer peripheral surface of the spacer body 62 and the inner tapered surface 30 in the tube diameter direction 12 increases as it approaches the opening end of the socket 5.

[0093] like Fig.14 As shown, the spacer 61 is divided into a plurality of arc-shaped divided pieces 68a to 68f in the tube circumferential direction 67. That is, each divided piece 68a to 68f includes a spacer body 62 divided into a plurality of pieces in the tube circumferential direction 67 and first and second centering contact portions 63 and 64.

[0094] The ends of the lower half segments 68a to 68c adjacent in the tube circumferential direction 67 are joined together by a connecting member 69, and the ends of the upper half segments 68d to 68f are joined together by a connecting member 69. The connecting member 69 includes a connecting plate 70, bolts 71, and the like.

[0095] For example, the connecting plate 70 is brought into contact with the inner circumference of the adjacent split piece 68a on one side and the inner circumference of the split piece 68b on the other side. Then, one end of the connecting plate 70 is connected to the split piece 68a on one side using the bolt 71 on one side, and the other end of the connecting plate 70 is connected to the split piece 68b on the other side using the bolt 71 on the other side. Thus, the split piece 68a on one side is joined to the split piece 68b on the other side.

[0096] Similarly, the split pieces 68a and 68c, the split pieces 68d and 68f, and the split pieces 68e and 68f are joined together using the connecting member 69 .

[0097] like Fig.15 As shown in FIG. 1 , the lower half of the split pieces 68a to 68c are joined together via the connecting member 69 to form a lower semicircular body 74 corresponding to the lower half of the spacer 61. Fig.16 As shown in FIG. 1 , the upper half divided pieces 68 d to 68 f are joined to each other via the connecting member 69 , thereby forming an upper semicircular body 75 corresponding to the upper half of the spacer 61 .

[0098] Between both end surfaces of the lower semicircular body 74 and the upper semicircular body 75 in the tube circumferential direction 67 facing each other in the vertical direction, headless bolts 77 for centering and nuts 78 threadedly engaged with the headless bolts 77 are provided.

[0099] Hereinafter, a method of assembling the spacer 61 and disposing it inside the socket 5 before joining the first pipe 2 to the second pipe 4 will be described.

[0100] First, if Fig.15 As shown, the three segmentation pieces 68a to 68c occupying the lower half of the receiving port 5 are arranged inside the receiving port 5. Fig.17 As shown in FIG. 6 , a space 66 is formed between the outer peripheral surface of the spacer body 62 in each of the split pieces 68a to 68c and the inner tapered surface 30. Therefore, there is no worry that the operator's hand 80 or fingers will be caught between the outer peripheral surface of the spacer body 62 in each of the split pieces 68a to 68c and the inner tapered surface 30. Therefore, the safety and workability of the assembly operation of the spacer 61 can be ensured.

[0101] Afterwards, if Fig.15 As shown, the lower half of the split pieces 68 a to 68 c are joined together using the connecting plate 70 of the connecting member 69 and the bolts 71 , thereby forming a lower semicircular body 74 corresponding to the lower half of the spacer 61 .

[0102] Thereafter, the headless bolts 77 having nuts 78 screwed therein are attached to both end surfaces of the lower semicircular body 74 so that the upper portions of the headless bolts 77 protrude upward from both end surfaces of the lower semicircular body 74 .

[0103] like Fig.16 As shown, the remaining three segmentation pieces 68d to 68f occupying the upper half of the receiving port 5 are arranged inside the receiving port 5. Fig.17 Similarly, in the case of the split pieces 68a to 68c of the lower half shown, since the space 66 is formed between the outer peripheral surface of the spacer body 62 and the inner tapered surface 30 in each of the split pieces 68d to 68f, there is no worry that the operator's hand 80 or fingers will be caught between the outer peripheral surface of the spacer body 62 and the inner tapered surface 30 in each of the split pieces 68d to 68f. Therefore, the safety and workability of the assembly operation of the spacer 61 can be ensured.

[0104] After that, the upper half split pieces 68d to 68f are joined to each other by using the connecting plate 70 and the bolt 71 of the connecting member 69, thereby forming the upper semicircular body 75 corresponding to the upper half of the spacer 61. Then, the upper part of the headless bolt 77 is inserted into the hole formed in the both end surfaces of the upper semicircular body 75. Thus, the headless bolt 77 and the nut 78 are arranged between the both end surfaces of the lower semicircular body 74 and the both end surfaces of the upper semicircular body 75.

[0105] Next, the upper semicircular body 75 is lifted using a jack or the like so that the outer peripheral end of the first centering contact portion 63 of the upper semicircular body 75 contacts the inner peripheral surface 34 a of the bending angle limiting portion 34 , and the outer peripheral end of the second centering contact portion 64 contacts the centering surface 36 in the socket 5 .

[0106] In this state, if Fig.14 As shown, the spacer 61 is assembled by rotating the nut 78 of the headless bolt 77 to raise it and making the nut 78 contact the two end surfaces of the upper semicircular body 75. Afterwards, the spacer 61 is set inside the socket 5 by removing the jack.

[0107] At this time, if Fig.13 As shown, the outer peripheral end of the first centering contact portion 63 of the spacer 61 is in contact with the inner peripheral surface 34a of the bending angle limiting portion 34, and the outer peripheral end of the second centering contact portion 64 is in contact with the centering surface 36 in the socket 5. Therefore, the installation position of the spacer 61 will not be offset in the pipe diameter direction 12, and the centering operation of the spacer 61 relative to the socket 5 can be easily performed.

[0108] After that, the locking ring 8 is assembled in the locking ring receiving groove 7, and the insertion port 3 is inserted into the socket 5 until the front end of the insertion port 3 abuts against the spacer 61. Furthermore, the support ring 24 and the sealing ring 13 are respectively inserted from the open end of the socket 5 between the outer circumference of the insertion port 3 and the inner circumference of the socket 5, and the pressure ring 15 is connected to the open end of the socket 5 using the bolt 20 and the nut 21. Thus, the first tube 2 is joined to the second tube 4, and the spacer 61 is provided between the front end of the insertion port 3 and the inner end surface 26 of the socket 5.

[0109] In such a pipe joint 54, as described above, since the spacer 61 is provided between the front end of the insertion port 3 and the inner end surface 26 of the socket 5, the movement of the insertion port 3 in the insertion direction is restricted. In addition, the insertion port protrusion 10 is hooked on the locking ring 8, thereby restricting the movement of the insertion port 3 in the disengagement direction. Therefore, the relative movement of the insertion port 3 and the socket 5 in the pipe axis direction 23 is restricted. Therefore, Fig.12 As shown, in the portion where the uneven force 53 acts on the pipe 51, the movement of the pipe joint 54 is restricted, and the telescopic function between the insertion port 3 and the socket 5 and the bending function between the insertion port 3 and the socket 5 are restricted. Thus, it is possible to prevent the pipe 51 from telescoping or bending in the direction in which the uneven force 53 acts, thereby preventing the sealing performance of the pipe joint 54 from being adversely affected.

[0110] In the above second embodiment, if Fig.14 As shown in the figure, the spacer 61 is divided into six divided pieces 68a to 68f, but the number is not limited to six, and the spacer 61 may be divided into a plurality of pieces other than six.

[0111] In the first and second embodiments described above, Figure 1 , Fig.13 As shown, the bending angle limiting portion 34 is formed between the inner wall portion 32 and the inner end face 26 on the tube axis direction 23, and leaves from the inner wall portion 32 to the inner side of the socket 5. However, it can also be that the bending angle limiting portion 34 extends towards the open end of the socket 5 and is connected to the inner wall portion 32.

Claims

1. A pipe joint, comprising: an insertion port formed in the first tube; A receiving port, the receiving port being formed on the second pipe; A locking ring groove, the locking ring groove being formed on the inner circumference of the receiving interface; A locking ring, the locking ring being received in the locking ring receiving groove; as well as an insertion port engaging portion, wherein the insertion port engaging portion is formed on the outer periphery of the insertion port, When the insertion port is inserted into the socket, the insertion port engaging portion is hooked on the locking ring from the inner side of the socket in the disengagement direction of the insertion port, thereby preventing the insertion port from being disengaged from the socket. The invention is characterized in that: The socket has an inner conical surface on the inner circumference that expands from the inner end of the socket toward the open end of the socket and a bending angle limiting portion that protrudes inward from the inner circumference of the socket in the pipe diameter direction. The inner conical surface is formed between the locking ring receiving groove and the inner end of the socket. The bending angle restricting portion prevents the first tube from bending relative to the second tube beyond a permissible angle.

2. The pipe joint according to claim 1, characterized in that: The socket has an outer tapered surface on the outer periphery thereof, the diameter of which increases from the inner side of the socket toward the open end of the socket.

3. The pipe joint according to claim 1, characterized in that: A spacer is provided between the front end of the insertion port and the inner end of the receiving port for limiting the movement of the insertion port in the insertion direction toward the receiving port. At a position closer to the inner side of the receiving interface than the bending angle limiting portion, a centering surface is formed between the inner conical surface of the receiving interface and the inner end portion. The spacer has a first centering contact portion in contact with the inner peripheral surface of the bending angle restricting portion and a second centering contact portion in contact with the centering surface.

4. The pipe joint according to claim 3, characterized in that: The spacer has a cylindrical spacer body disposed between the front end of the insertion port and the inner end of the receiving port, and is divided into a plurality of arc-shaped divided pieces in the circumferential direction of the pipe. The ends of the adjacent split pieces in the circumferential direction of the tube are connected to each other. The first centering contact portion is provided at one end of the spacer body in the tube axis direction. The second centering contact portion is provided at the other end of the spacer body in the tube axis direction. A space is formed between the first centering contact portion and the second centering contact portion in the tube axis direction and between the outer peripheral surface and the inner tapered surface of the spacer body in the tube diameter direction. The distance between the outer peripheral surface of the spacer body and the inner tapered surface in the pipe diameter direction increases as it approaches the opening end of the receiving port.

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