Pipe fittings

Abstract

To provide a pipe joint which can reduce the weight of a receptacle.SOLUTION: In a pipe joint 1, a spigot 3 of one pipe 2 is inserted into a receptacle 5 of the other pipe 4, a lock ring 8 is accommodated in a lock ring accommodation groove 7 which is formed at an internal periphery of the receptacle 5, and a spigot engagement part 10 formed at an external periphery of the spigot 3 prevents the release of the spigot 3 by being engaged with the lock ring 8. The receptacle 5 has an inside tapered face 30 which is expanded in a diameter toward an opening end part from a depth end side at an internal periphery, the inside tapered face 30 is formed between the lock ring accommodation groove 7 and a depth end part 26 of the receptacle 5, a bending angle limit protrusion 34 protruding inside a pipe diameter direction is arranged at the inside tapered face 30, and the bending angle limit protrusion 34 prohibits the bending of one pipe 2 to the other pipe 4 while exceeding an allowable angle.SELECTED DRAWING: Figure 1

Description

Technical Field

[0005] ,

[0004] , , , , , ,

[0003] ,

[0006]

[0001] The present invention relates to a pipe joint with a detachment prevention function for preventing the insertion port from detaching from the receiving port.

Background Art

[0002] Conventionally, as this type of pipe joint, for example, as shown in FIG. 18, a pipe joint 205 in which the insertion port of one pipe 201 is inserted into the receiving port of the other pipe 203 is known. A lock ring accommodation groove 206 is formed on the inner circumference of the receiving port 204, and a lock ring 207 is accommodated in the lock ring accommodation groove 206. An insertion port protrusion 208 is formed on the outer circumference of the insertion port 202, and by engaging the insertion port protrusion 208 with the lock ring 207 from the back side of the receiving port 204 in the detachment direction 209 of the insertion port 202, it is possible to prevent the insertion port 202 from detaching from the receiving port 204. <00000"11> A seal member 210 for sealing between the inner circumference of the receiving port 204 and the outer circumference of the insertion port 202 is inserted from the opening end surface 211 of the receiving port 204 between the inner circumference of the receiving port 204 and the outer circumference of the insertion port 202. Further, a pressing ring 212 for pressing the seal member 210 is connected to the receiving port 204 via bolts 213 and nuts 214. [[ID=1"8]]

[0004] The pipes 201 and 203 are, for example, ductile iron pipes cast by a centrifugal casting method. During centrifugal casting, in order to pull out the pipes 201 and 203 from the mold for centrifugal casting, the receiving port 204 has an outer tapered surface 216 on the outer circumference that gradually increases in diameter from the back end surface 215 of the receiving port 204 toward the opening end surface 211.

[0005] Further, the receiving port 204 has an inner straight surface 217 on the inner circumference, and the inner straight surface 217 is parallel to the pipe axis of the other pipe 203 between the lock ring accommodation groove 206 and the back end surface 215 of the receiving port 204 in the pipe axis direction 218. Thereby, the inner diameter d of the receiving port 204 is constant between the lock ring accommodation groove 206 and the back end surface 215 of the receiving port 204.

[0006] Furthermore, the pipe joint 205 described above is, for example, described in Patent Document 1 below. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-74980 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in the conventional design described above, the pipe thickness T of the socket 204 increases as it approaches the lock ring housing groove 206 from the inner end face 215 of the socket 204. This increases the weight of the socket 204, which in turn increases the weight of the entire pipe.

[0009] The present invention aims to provide a pipe joint that can reduce the weight of the socket. [Means for solving the problem]

[0010] To achieve the above objective, the first invention is such that the insertion end of one pipe is inserted into the receiving end of the other pipe. A lock ring receiving groove is formed on the inner circumference of the socket. The lock ring is housed in the lock ring housing groove. An insertion engagement portion is formed on the outer circumference of the insertion opening. A pipe fitting with a detachment prevention function, wherein the detachment engagement portion engages with the lock ring from the inner side of the socket in the direction of detachment of the detachment of the detachment, thereby preventing the detachment of the detachment from the socket. The socket engagement portion is provided protruding from the outer surface of the socket at a point where it is retracted by a predetermined length from the tip of the socket in the direction of separation from the socket, and a tip portion is formed on the tip side of the socket engagement portion that extends in the direction of the pipe axis by the predetermined length. The socket has an inner tapered surface on its inner circumference that widens in diameter from the inner end of the socket towards the open end of the socket. The inner tapered surface is formed between the lock ring receiving groove of the socket and the inner end. On the inner tapered surface Between the lock ring housing groove and the inner end of the receiving opening A bending angle limiting projection is provided that protrudes inward in the diameter direction from the inner tapered surface. Between the bending angle limiting projection and the lock ring housing groove, an annular recess is formed with the inner tapered surface as its bottom surface. The bending angle limiting projection is 、 One pipe to the other pipe When bent, The outer surface of the tip of the insertion port comes into contact with the inner surface of the bending angle limiting projection, and the insertion port engagement portion fits into the annular recess, so that one pipe is connected to the other pipe. Prevents bending beyond the allowable angle. death, The outer surface of the tip of the insertion opening contacts the inner tapered surface without contacting the inner surface of the bending angle limiting projection, further inside the receiving opening than the bending angle limiting projection, thereby ensuring that one pipe and the other pipe are sufficiently bent to achieve the required bending performance. It is.

[0011] According to this design, the socket has an inner tapered surface on its inner circumference that widens from the inner end of the socket towards the open end. As a result, the thickness of the socket is thinner between the lock ring receiving groove and the inner end of the socket compared to a case with an inner straight surface. This makes it possible to reduce the weight of the socket.

[0012] Furthermore, the tapered inner surface of the socket increases the bending angle of the insertion end relative to the socket, improving the bending performance of one pipe and the other pipe. As a result, the pipes can bend sufficiently in response to shaking during an earthquake, preventing damage to the pipes.

[0013] Furthermore, because the spigot abuts against the bending angle limiting projection of the socket, the bending angle of the spigot relative to the socket is limited to below the allowable angle. This prevents the spigot from bending excessively relative to the socket, thus preventing water leakage from between the spigot and the socket.

[0014] In the pipe joint of this second invention, the socket has an outer tapered surface on its outer circumference that widens in diameter from the inner end of the socket toward the open end of the socket.

[0015] According to this, the pipe thickness of the socket can be made almost uniform between the lock ring housing groove and the inner end of the socket.

[0016] In the pipe joint of this third invention, a spacer is provided between the tip of the spigot and the back of the socket to restrict the relative movement of the spigot and the socket in the pipe axis direction. A contact surface having an inner diameter the same as that of the inner diameter of the bending angle limiting protrusion is formed between the inner tapered surface and the inner end portion of the receiving port on the inner side of the receiving port further back than the bending angle limiting protrusion. The spacer has a first centering contact portion that contacts the inner peripheral surface of the bending angle limiting protrusion and a second centering contact portion that contacts the contact surface.

[0017] According to this, by providing a spacer between the tip of the insertion port and the inner end of the receiving port, relative movement in the pipe axis direction between the insertion port and the receiving port is restricted. For this reason, in a portion where an uneven force acts on the pipeline, the pipe joint is restrained so as not to move, and the expansion and contraction function and the bending function between the insertion port and the receiving port are regulated. Thereby, it is possible to prevent the pipeline from expanding, contracting, or bending in the direction in which the uneven force acts and adversely affecting the sealing performance of the pipe joint.

[0018] Also, when the spacer is provided inside the receiving port, since the first centering contact portion of the spacer contacts the inner peripheral surface of the bending angle limiting protrusion and the second centering contact portion contacts the contact surface, the mounting position of the spacer does not shift in the pipe diameter direction, and the centering operation of the spacer with respect to the receiving port can be facilitated.

[0019] In the pipe joint according to the fourth invention, the spacer has a cylindrical spacer body disposed between the tip 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 adjacent divided pieces in the circumferential direction of the pipe are connected to each other. [[ID=1'])) The first centering contact portion and the second centering contact portion are provided at both ends of the spacer body in the pipe axis direction. A space is formed between the first centering contact portion and the second centering contact portion in the pipe axis direction and between the outer peripheral surface and the inner tapered surface of the spacer body in the pipe diameter direction. The distance between the outer peripheral surface and the inner tapered surface of the spacer body in the pipe diameter direction expands toward the opening end of the receiving port.

[0020] According to this, when assembling a spacer by setting multiple segmented pieces inside the socket, a space is formed between the outer surface and the inner tapered surface of the spacer body. Therefore, there is no need to worry about the worker's hand getting caught between the outer surface and the inner tapered surface of the spacer body, improving the safety and work efficiency of the spacer assembly process. [Effects of the Invention]

[0021] As described above, according to the present invention, the socket has an inner tapered surface on its inner circumference that widens from the inner end of the socket towards the open end of the socket. Therefore, compared to the case where there is an inner straight surface, the pipe thickness of the socket is thinner between the lock ring receiving groove and the inner end of the socket. This makes it possible to lighten the weight of the socket, and the weight of the entire pipe is reduced. [Brief explanation of the drawing]

[0022] [Figure 1] This is a cross-sectional view of a pipe joint according to the first embodiment of the present invention, showing the state when the spigot is inserted into the socket by the normal insertion amount and is not bent relative to the socket. [Figure 2] This is a cross-sectional view of the pipe joint in the first embodiment, showing the state when the spigot is inserted into the socket by the normal insertion amount and is bent relative to the socket. [Figure 3] Figure 2 is an enlarged cross-sectional view of a portion of the pipe joint. [Figure 4] This is a cross-sectional view of a pipe fitting in a first reference example of the present invention, showing the spigot being inserted into the socket by the normal insertion amount and bent relative to the socket. [Figure 5] Figure 4 is an enlarged cross-sectional view of a portion of the pipe joint. [Figure 6] This is a cross-sectional view of a pipe joint in a second reference example of the present invention, showing the state when the spigot is inserted into the socket by the normal insertion amount and is bent relative to the socket. [Figure 7] This is a cross-sectional view of the pipe joint in the first embodiment, showing the state when the spigot is inserted into the socket by a larger insertion amount than the normal insertion amount and is bent relative to the socket. [Figure 8]Figure 7 is an enlarged cross-sectional view of a portion of the pipe joint. [Figure 9] This is a cross-sectional view of a pipe fitting in a third reference example of the present invention, showing the case where the spigot is inserted into the socket by a larger insertion amount than the normal insertion amount and is bent relative to the socket. [Figure 10] Figure 9 is an enlarged cross-sectional view of a portion of the pipe joint. [Figure 11] This is a cross-sectional view of the pipe joint in the first embodiment, showing the state when the spigot is moving in the detachment direction and the spigot projection is engaged with the lock ring, and the spigot is bent relative to the socket. [Figure 12] This is a diagram of a pipeline equipped with a pipe joint according to a second embodiment of the present invention. [Figure 13] This is a cross-sectional view of the pipe joint in the second embodiment. [Figure 14] This is a front view of the spacer provided in the pipe fitting. [Figure 15] This diagram shows the procedure for assembling the spacers. [Figure 16] This diagram shows the procedure for assembling the spacers. [Figure 17] This diagram shows the procedure for assembling the spacers. [Figure 18] This is a cross-sectional view of a conventional pipe fitting. [Modes for carrying out the invention]

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0024] (First Embodiment) In the first embodiment, as shown in Figure 1, 1 is a pipe fitting with an anti-detachment function, in which the socket 3 of one pipe 2 is inserted into the socket 5 of the other pipe 4. These pipes 2 and 4 are made of, for example, ductile iron pipes and are manufactured by centrifugal casting.

[0025] A lock ring housing groove 7 is formed around the entire inner circumference of the socket 5. A lock ring 8 is housed in the lock ring housing groove 7. The lock ring 8 is a one-piece ring with a cut in one place.

[0026] A projection 10 (an example of a socket engagement portion) is formed around the entire circumference of the socket 3. The projection 10 is located at a point where it recedes by a predetermined length in the disengagement direction 6 from the tip of the socket 3. The projection 10 engages with the lock ring 8 from the back of the socket in the disengagement direction 6 of the socket 3, thereby preventing the socket 3 from disengaging from the socket 5.

[0027] A seal ring 13 is provided on the opening end side of the socket 5, relative to the lock ring 8, which is compressed in the radial direction 12 of the pipe to seal the space between the outer surface of the insertion port 3 and the inner surface of the socket 5. The seal ring 13 is a rubber ring (rubber ring).

[0028] A push ring 15 is provided at the open end of the socket 5 to push the seal ring 13 toward the back of the socket. The push ring 15 has a contact portion 18 that abuts against the open end surface 17 of the socket 5 in the insertion direction 16 of the seal ring 13, and is connected to the open end of the socket 5 by a plurality of bolts 20 and nuts 21.

[0029] A backup ring 24 is provided between the lock ring 8 and the seal ring 13 in the axial direction 23 of the pipe. The backup ring 24 is a ring that maintains a predetermined distance between the outer surface of the insertion port 3 and the inner surface of the receiving port 5 in the radial direction 12 of the pipe.

[0030] The socket 5 has an outer tapered surface 29 on its outer circumference that widens in diameter from the inner end surface 26 (an example of the inner end) toward the open end of the socket 5, and an inner tapered surface 30 on its inner circumference that widens in diameter from the inner end surface 26 toward the open end of the socket 5.

[0031] Furthermore, by forming an outer tapered surface 29 on the socket 5, when withdrawing the tube 4 from the centrifugal casting mold during centrifugal casting, it can be withdrawn from the socket 5 side.

[0032] The inner tapered surface 30 is formed between the groove back wall 32 that constitutes the lock ring housing groove 7 and the back end surface 26 of the receiving opening 5. The outer tapered surface 29 and the inner tapered surface 30 are inclined at the same angle and are parallel to each other.

[0033] The inner tapered surface 30 has a bending angle limiting projection 34 that protrudes inward in the pipe diameter direction 12 from the inner tapered surface 30, extending around its entire circumference. The bending angle limiting projection 34 prevents one pipe 2 from bending beyond the maximum allowable angle (e.g., 7°) relative to the other pipe 4.

[0034] The inner circumferential surface 34a of the bending angle limiting projection 34 is parallel to the pipe axis 4a of the other pipe 4 and is a straight surface formed in the pipe axis direction 23.

[0035] Furthermore, a contact surface 36 having an inner diameter d2 that is the same as the inner diameter d1 of the bending angle limiting projection 34 is formed around the entire circumference between the inner tapered surface 30 and the inner end surface 26 of the receiving opening 5, on the inner side of the receiving opening 5 beyond the bending angle limiting projection 34. The contact surface 36 is parallel to the pipe axis 4a of the other pipe 4 and is a straight surface formed straight in the pipe axis direction 23.

[0036] The insertion port 3 is inserted into the receiving port 5 with the correct insertion amount, and in this case, the insertion port projection 10 is in approximately the same position as the bending angle limiting projection 34 of the receiving port 5 in the pipe axis direction 23.

[0037] The operation of the above configuration will be explained below.

[0038] Since the outer tapered surface 29 and the inner tapered 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 almost uniform between the lock ring housing groove 7 and the inner end surface 26 of the socket 5. Compared to the case where the socket 5 has an inner straight surface (see inner straight surface 217 in Figure 18), the pipe thickness T becomes thinner between the lock ring housing groove 7 and the inner end surface 26 of the socket 5. This makes it possible to lighten the weight of the socket 5, and the weight of the entire pipe is reduced.

[0039] Furthermore, when the Socket 3 is inserted into the Receptacle 5 and bent relative to the Receptacle 5, the Receptacle 5 has an inner tapered surface 30, which increases the bending angle α of the Socket 3 relative to the Receptacle 5, improving the bending performance of one pipe 2 and the other pipe 4. As a result, the pipes 2 and 4 can bend sufficiently in response to shaking during an earthquake, preventing damage to the pipes 2 and 4.

[0040] Figures 2 and 3 show the state in which the insertion port 3 is inserted into the receiving port 5 by the normal insertion amount and bent. In this case, the outer circumferential surface of the tip of the insertion port 3 abuts against the inner circumferential surface 34a of the bending angle limiting projection 34, thereby limiting the bending angle α to less than or equal to the maximum allowable angle, preventing the insertion port 3 from bending excessively relative to the receiving port 5. This ensures that the sealing function of the seal ring 13 is sufficiently maintained and prevents water leakage from occurring between the outer circumferential surface of the insertion port 3 and the inner circumferential surface of the receiving port 5.

[0041] In contrast, as a first reference example, the socket 5 of the pipe joint 101 shown in Figures 4 and 5 does not have an inner tapered surface 30 on its inner circumference, but has an inner straight surface 102 parallel to the pipe axis 4a of the other pipe 4.

[0042] According to this, when the Socket 3 is inserted into the Receptacle 5 by the normal insertion amount, and the Socket 3 bends relative to the Receptacle 5, the Socket projection 10 comes into contact with the inner straight surface 102 of the Receptacle 5. As a result, the bending angle α1 of the Socket 3 relative to the Receptacle 5 becomes smaller than the bending angle α of the pipe joint 1 shown in Figure 2. Consequently, the pipe joint 101 of the first reference example has inferior bending performance between one pipe 2 and the other pipe 4 compared to the pipe joint 1 shown in Figure 2.

[0043] As a second example, the socket 5 of the pipe joint 111 shown in Figure 6 has an inner tapered surface 30, but does not have a bending angle limiting projection 34.

[0044] According to this, when the Socket 3 is inserted into the Receptacle 5 by the correct insertion amount, and the Socket 3 bends relative to the Receptacle 5, the outer circumferential surface of the tip of the Socket 3 comes into contact with the inner tapered surface 30. As a result, the bending angle α2 of the Socket 3 relative to the Receptacle 5 may become larger than the bending angle α of the pipe fitting 1 shown in Figure 2, exceeding the maximum allowable angle. Consequently, in the pipe fitting 111 of the second reference example, the Socket 3 bends excessively relative to the Receptacle 5, reducing the sealing function of the seal ring 13, and there is a risk of water leakage occurring between the outer circumferential surface of the Socket 3 and the inner circumferential surface of the Receptacle 5.

[0045] Furthermore, in Figures 2 and 3 of the first embodiment, the insertion port 3 is shown bent relative to the receiving port 5 when it is inserted into the receiving port 5 by the normal insertion amount. However, in Figures 7 and 8 of the first embodiment, the insertion port 3 is shown bent relative to the receiving port 5 when it is inserted into the receiving port 5 by an insertion amount greater than the normal insertion amount.

[0046] According to this, the outer surface of the tip of the insertion opening 3 abuts against the inner tapered surface 30 and does not abut against the bending angle limiting projection 34. As a result, the bending angle α of the insertion opening 3 relative to the receiving opening 5 increases within a range less than or equal to the maximum allowable angle, improving the bending performance between one pipe 2 and the other pipe 4.

[0047] In contrast, as a third reference example, the socket 5 of the pipe joint 101 shown in Figures 9 and 10 does not have an inner tapered surface 30 on its inner circumference, but has an inner straight surface 102 parallel to the pipe axis 4a of the other pipe 4.

[0048] According to this, when the Socket 3 is inserted into the Receptacle 5 by a larger insertion amount than the normal insertion amount, and the Socket 3 bends relative to the Receptacle 5, the Socket projection 10 comes into contact with the inner straight surface 102 of the Receptacle 5. As a result, the bending angle α3 of the Socket 3 relative to the Receptacle 5 becomes smaller than the bending angle α of the pipe joint 1 shown in Figure 7. Consequently, the pipe joint 101 of the third reference example has inferior bending performance between one pipe 2 and the other pipe 4 compared to the pipe joint 1 shown in Figure 7.

[0049] Furthermore, as shown in Figure 11 in the first embodiment, when the insertion port 3 moves in the detachment direction 6 and the insertion port projection 10 engages with the lock ring 8, and the insertion port 3 bends relative to the receiving port 5, the outer circumference of the insertion port projection 10 abuts against the inner circumference of the groove back wall 32, so that the bending angle of the insertion port 3 relative to the receiving port 5 is maintained at a predetermined angle α4 which is less than or equal to the maximum allowable angle. In this case, even for pipe fittings 101 which have an inner straight surface 102 instead of the inner tapered surface 30 shown as the reference example above, and pipe fittings 111 which have an inner tapered surface 30 but do not have a bending angle limiting projection 34, the bending angle of the insertion port 3 relative to the receiving port 5 is maintained at the same predetermined angle α4 as above.

[0050] (Second Embodiment) The second embodiment will be described below with reference to Figures 12 to 17. Note that components identical to those described in the first embodiment will be denoted by the same reference numerals, and detailed explanations will be omitted.

[0051] As shown in Figure 12, 51 is a pipeline formed by joining multiple pipes, and this pipeline 51 has a bend 52, at which an unequal force 53 acts. A pipe joint 54 is provided in such a pipeline 51, and in the pipe joint 54, the insertion port 3 of one pipe 2 is inserted into the receiving port 5 of the other pipe 4, thereby joining the pipes 2 and 4 together.

[0052] As shown in Figure 13, the pipe joint 54 is provided with a spacer 61 to restrict the relative movement of the spigot 3 and the socket 5 in the pipe axis direction 23. The spacer 61 has a cylindrical spacer body 62 positioned between the tip of the spigot 3 and the inner end face 26 of the socket 5, a first centering contact portion 63 that abuts against the inner circumferential surface 34a of the bending angle limiting projection 34, and a second centering contact portion 64 that abuts against the contact surface 36 inside the socket 5.

[0053] The first centering contact portion 63 and the second centering contact portion 64 are provided around the entire circumference of both ends of the spacer body 62 in the pipe axis direction 23, and are annular members that protrude outward in the pipe diameter direction 12 from the outer circumferential surface of the spacer body 62.

[0054] A space 66 is formed around the entire circumference between the first centering contact portion 63 and the second centering contact portion 64 in the axial direction 23 of the pipe, and between the outer circumferential surface of the spacer body 62 and the inner tapered surface 30 in the radial direction 12 of the pipe. The distance S between the outer circumferential surface of the spacer body 62 and the inner tapered surface 30 in the radial direction 12 of the pipe increases towards the opening end of the socket 5.

[0055] Furthermore, as shown in Figure 14, the spacer 61 is divided into a plurality of arc-shaped segments 68a to 68f in the circumferential direction 67 of the pipe. That is, each segment 68a to 68f has a spacer body 62 that is divided into multiple parts in the circumferential direction 67 of the pipe, and first and second centering contact portions 63, 64.

[0056] In the circumferential direction 67 of the pipe, the ends of adjacent segmented pieces 68a to 68f are connected by a connecting member 69. The connecting member 69 includes a connecting plate 70 and bolts 71, etc.

[0057] For example, a connecting plate 70 is placed across the inner circumference of one adjacent segment 68a and the inner circumference of the other segment 68b. One end of the connecting plate 70 is fastened to the segment 68a using one bolt 71, and the other end of the connecting plate 70 is fastened to the other segment 68b using the other bolt 71, thereby connecting one segment 68a to the other segment 68b.

[0058] Similarly, the dividing pieces 68a and 68c, 68d and 68f, and 68e and 68f are joined together using the connecting member 69.

[0059] As shown in Figure 15, the lower half of the divided pieces 68a to 68c are connected via the connecting member 69 to form the lower semicircular body 74, which corresponds to the lower half of the spacer 61. As shown in Figure 16, the upper half of the divided pieces 68d to 68f are connected via the connecting member 69 to form the upper semicircular body 75, which corresponds to the upper half of the spacer 61.

[0060] Between the end faces of the lower semicircular body 74 and the end faces of the upper semicircular body 75, which are opposite each other in the vertical direction, are provided a centering bolt 77 and a nut 78 screwed onto the centering bolt 77.

[0061] The following describes how to assemble the spacer 61 and set it inside the socket 5 before joining one pipe 2 to the other pipe 4.

[0062] First, as shown in Figure 15, the three divided pieces 68a to 68c, which occupy the lower half of the socket 5, are set inside the socket 5. At this time, as shown in Figure 17, a space 66 is formed between the outer circumferential surface of the spacer body 62 and the inner tapered surface 30 of each divided piece 68a to 68c, so there is no need to worry about the worker's hand 80 or fingers getting caught between the outer circumferential surface of the spacer body 62 and the inner tapered surface 30 of each divided piece 68a to 68c, thus improving the safety and workability of the spacer 61 assembly work.

[0063] Subsequently, as shown in Figure 15, the lower half of the divided pieces 68a to 68c are joined together using the connecting plate 70 and bolt 71 of the connecting member 69 to form the lower semicircular body 74, which corresponds to the lower half of the spacer 61.

[0064] Subsequently, centering bolts 77 with nuts 78 screwed onto them are erected on both end faces of the lower semicircular body 74.

[0065] Then, as shown in Figure 16, the remaining three segmented pieces 68d to 68f, which occupy the upper half of the receiving opening 5, are set inside the receiving opening 5. At this time, a space 66 is formed between the outer circumferential surface of the spacer body 62 and the inner tapered surface 30 of each segmented piece 68d to 68f, so there is no need to worry about the worker's hand 80 or fingers getting caught between the outer circumferential surface of the spacer body 62 and the inner tapered surface 30 of each segmented piece 68d to 68f, thus improving the safety and workability of the spacer 61 assembly work.

[0066] Subsequently, the upper halves of the divided pieces 68d to 68f are joined together using the connecting plate 70 and bolt 71 of the connecting member 69 to form the upper semicircular body 75, which corresponds to the upper half of the spacer 61. As a result, the centering bolt 77 and nut 78 are provided between the end faces of the lower semicircular body 74 and the end faces of the upper semicircular body 75.

[0067] Next, the upper semicircular body 75 is lifted using a jack or the like, and the outer peripheral end of the first centering contact portion 63 of the upper semicircular body 75 is brought into contact with the inner peripheral surface 34a of the bending angle limiting projection 34, while the outer peripheral end of the second centering contact portion 64 is brought into contact with the contact surface 36 inside the receiving opening 5.

[0068] In this state, as shown in Figure 14, the nut 78 of the centering bolt 77 is turned to raise it, and the nut 78 is brought into contact with both end faces of the upper semicircular body 75, thereby assembling the spacer 61. After that, the jack is removed, and the spacer 61 is set inside the socket 5.

[0069] In this case, as shown in Figure 13, the outer peripheral end of the first centering contact portion 63 of the spacer 61 abuts against the inner peripheral surface 34a of the bending angle limiting projection 34, and the outer peripheral end of the second centering contact portion 64 abuts against the contact surface 36 inside the socket 5. As a result, the mounting position of the spacer 61 does not shift in the diameter direction 12 of the pipe, and the centering work of the spacer 61 with respect to the socket 5 can be easily performed.

[0070] Next, the lock ring 8 is placed in the lock ring housing groove 7, and the insertion port 3 is inserted into the receiving port 5 until the tip of the insertion port 3 abuts against the spacer 61. Furthermore, the backup ring 24 and the seal ring 13 are inserted from the open end of the receiving port 5 between the outer surface of the insertion port 3 and the inner surface of the receiving port 5, and the thrust ring 15 is connected to the open end of the receiving port 5 using the bolt 20 and nut 21. As a result, one pipe 2 is joined to the other pipe 4, and the spacer 61 is provided between the tip of the insertion port 3 and the inner end surface 26 of the receiving port 5.

[0071] In such a pipe joint 54, as described above, the spacer 61 is provided between the tip of the spigot 3 and the inner end face 26 of the socket 5, thereby restricting the relative movement of the spigot 3 and the socket 5 in the pipe axis direction 23. Therefore, as shown in Figure 12, in the portion where an unbalanced force 53 acts on the pipe 51, the pipe joint 54 is constrained to not move, and the expansion and contraction function between the spigot 3 and the socket 5, as well as the bending function between the spigot 3 and the socket 5, are restricted. This prevents the pipe 51 from expanding or contracting or bending in the direction in which the unbalanced force 53 acts, thereby preventing adverse effects on the sealing performance of the pipe joint 54.

[0072] In the second embodiment described above, as shown in Figure 14, the spacer 61 is divided into six segments 68a to 68f, but it is not limited to six segments, and may be divided into more than six segments.

[0073] In the first and second embodiments described above, as shown in Figures 1 and 13, the bending angle limiting projection 34 is formed between the groove back wall 32 and the back end face 26 in the pipe axis direction 23 and is spaced apart from the groove back wall 32 toward the back of the receiving opening 5. However, the bending angle limiting projection 34 may also be extended toward the opening end of the receiving opening 5 and connected to the groove back wall 32. [Explanation of symbols]

[0074] 1.54 Pipe fittings 2 One pipe 3. Insertion port 4 The other pipe 5 socket 6. Direction of departure 7. Lock ring housing groove 8 lock rings 10. Socket protrusion (Socket engagement part) 12 Pipe diameter direction 23 Tube axis direction 26 Back end surface (back end) 29 Outer tapered surface 30 Inner tapered surface 34 Bending angle limiting projection 34a Inner circumferential surface of the bending angle limiting projection 36 Contact surface 61 Spacer 62 Spacer body 63 First centering contact part 64 Second centering contact section 66 Space 67 Circumferential direction 68a~68f split piece d1 Inner diameter of the bending angle limiting projection d2 Inner diameter of the contact surface S Spacer body distance between outer surface and inner tapered surface

Claims

1. The socket of one pipe is inserted into the socket of the other pipe. A lock ring receiving groove is formed on the inner circumference of the socket. The lock ring is housed in the lock ring housing groove. An insertion engagement portion is formed on the outer circumference of the insertion opening. A pipe fitting with a detachment prevention function, wherein the detachment engagement portion engages with the lock ring from the inner side of the socket in the direction of detachment of the detachment of the detachment, thereby preventing the detachment of the detachment from the socket. The socket engagement portion is provided protruding from the outer surface of the socket at a point where it is retracted by a predetermined length from the tip of the socket in the direction of separation from the socket, and a tip portion is formed on the tip side of the socket engagement portion that extends in the direction of the pipe axis by the predetermined length. The socket has an inner tapered surface on its inner circumference that widens in diameter from the inner end of the socket towards the open end of the socket. The inner tapered surface is formed between the lock ring receiving groove of the socket and the inner end. Between the lock ring receiving groove of the socket on the inner tapered surface and the inner end, a bending angle limiting projection is provided that protrudes inward in the diameter direction from the inner tapered surface. Between the bending angle limiting projection and the lock ring housing groove, an annular recess is formed with the inner tapered surface as its bottom surface. The bending angle limiting projection is such that when one pipe is bent relative to the other pipe, The outer circumferential surface of the tip of the insertion port contacts the inner circumferential surface of the bending angle limiting projection, and the insertion port engagement portion engages with the annular recess, thereby preventing one pipe from bending beyond the allowable angle relative to the other pipe. A pipe joint characterized in that the outer surface of the tip of the insertion opening contacts the inner tapered surface without contacting the inner surface of the bending angle limiting projection, further inside the receiving opening than the bending angle limiting projection, thereby ensuring that one pipe and the other pipe are sufficiently bent to achieve the required bending performance.

2. The pipe fitting according to claim 1, characterized in that the socket has an outer tapered surface on its outer circumference that widens in diameter from the inner end of the socket toward the open end of the socket.

3. A spacer is provided between the tip of the spigot and the back of the socket to restrict the relative movement of the spigot and the socket in the axial direction of the pipe. A contact surface having the same inner diameter as the inner diameter of the bending angle limiting projection is formed between the inner tapered surface of the socket and the inner end of the socket, further inside the socket than the bending angle limiting projection. The pipe joint according to claim 1, characterized in that the spacer has a first centering contact portion that abuts against the inner circumferential surface of the bending angle limiting projection and a second centering contact portion that abuts against the contact surface.

4. The spacer has a cylindrical spacer body positioned between the tip of the insertion opening and the inner end of the receiving opening, and is divided into a plurality of arc-shaped segments in the circumferential direction of the pipe. The ends of adjacent segmented pieces are connected in the circumferential direction of the pipe. The first centering contact portion and the second centering contact portion are provided at both ends of the spacer body in the pipe axis direction. A space is formed between the first centering contact portion and the second centering contact portion in the axial direction of the pipe, and between the outer circumferential surface of the spacer body and the inner tapered surface in the radial direction of the pipe. The pipe joint according to claim 3, characterized in that the distance between the outer surface and the inner tapered surface of the spacer body in the radial direction of the pipe increases towards the opening end of the socket.

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