Joint structure, protective member and sealing member

Abstract

The present invention provides a joint structure that can suppress the axial movement of the sealing member when inserting the pipe's spigot into the receiving end of the pipe to be joined. [Solution] The joint structure 1 comprises an insertion opening 3 of a pipe W2, a receiving opening 2 of a pipe to be joined W1, a sealing member 4, and a protective member 5 that protects the sealing member 4. The receiving opening 2 has a groove 23 extending in the circumferential direction on its inner circumferential surface 21. The sealing member 4 has a sealing body portion 41 and an insertion support portion 42. The protective member 5 has a cover portion 51 that covers at least the inner circumferential surface of the insertion support portion 42, and a holding portion 52 that is held on the opening side of the receiving opening 2. The cover portion 51 has an engaging portion 51b on its outer circumferential surface that engages with a recess 421c or protrusion formed on the inner circumferential surface of the sealing member 4.

Description

Technical Field

[0001] The present invention relates to a joint structure, a protective member, and a sealing member including an insertion port of a pipe and a receiving port of a joined pipe joined to the pipe.

Background Art

[0002] A sealing member is known that is used in a joint structure including an insertion port of a pipe and a receiving port of a joined pipe joined to the pipe, and seals between the inner peripheral surface of the receiving port and the outer peripheral surface of the insertion port. As such a sealing member, for example, Patent Document 1 discloses a rubber ring including a heel portion that fits and engages in a locking groove formed on the peripheral surface of a rubber ring arrangement recess of a receiving port, and a valve portion that is compressed between the peripheral surface of the rubber ring arrangement recess and the outer peripheral surface of an insertion port to generate a sealing surface pressure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, pipe joining has been carried out manually by workers entering an excavation trench. Therefore, automation of pipe joining is required from the viewpoints of cost reduction, shortening of the construction period, stabilization of construction quality, and improvement of construction safety.

[0005] In promoting the automation of the pipe joining, the application work of a lubricant to a rubber ring and an insertion port in the excavation trench is an issue. This application work needs to be carried out manually by the worker before joining a joined pipe to the pipe, and if joining is not performed immediately after applying the lubricant, the lubricant may dry out.

[0006] On the other hand, if the lubricant is applied on the ground, the lubricant may dry out, or foreign matter may adhere to the rubber ring inside the socket or the insertion opening. If the application of the lubricant is insufficient in this way, the rubber ring may be dragged along the insertion opening when the insertion opening is inserted into the socket, causing the sealing member to move axially and shift from its predetermined position, which may result in water leakage.

[0007] The object of the present invention is to provide a joint structure, a protective member, and a sealing member that can suppress axial movement of the sealing member when it is inserted into the spigot of a pipe and the socket of a pipe to be joined. [Means for solving the problem]

[0008] A joint structure according to one embodiment of the present invention comprises a pipe slit, a receiving end of a pipe to be joined to the pipe, a sealing member made of an elastic material that seals the space between the outer circumferential surface of the pipe slit and the inner circumferential surface of the receiving end of the pipe to be joined, and a protective member that protects the sealing member. The receiving end has a groove extending in the circumferential direction on its inner circumferential surface, and the sealing member has an annular sealing body portion that is compressed radially by the outer circumferential surface of the slit and the inner circumferential surface of the receiving end, and an insertion support portion that is connected to the opening end of the receiving end of the sealing body portion and is configured to be insertable into the groove of the receiving end. The protective member has a cover portion that covers at least the inner circumferential surface of the insertion support portion of the sealing member, and a holding portion that is connected to the opening end of the receiving end of the cover portion and is held on the opening side of the receiving end. The cover portion has an engaging portion on its outer circumferential surface that engages with a recess or protrusion formed on the inner circumferential surface of the sealing member (first configuration).

[0009] In the above configuration, the protective member has a holding portion that is held on the opening side of the receiving end, and a cover portion that has an engaging portion that engages with a recess or protrusion formed on the inner circumferential surface of the sealing member. This prevents the sealing member from being dragged along the receiving end when inserting the insert end of the pipe into the receiving end of the pipe to be joined.

[0010] Therefore, it is possible to provide a joint structure that can suppress the axial movement of the sealing member when inserting the spigot of the pipe into the socket of the pipe to be joined.

[0011] In the first configuration described above, the recess is formed in an annular shape along the circumferential direction on the inner circumferential surface of the sealing member, and the engaging portion has a projection that engages with the recess (second configuration).

[0012] In the above configuration, the engaging portion of the protective member has a projection that engages with a recess formed in an annular shape along the circumferential direction on the inner surface of the sealing member. Therefore, the engagement force between the sealing member and the protective member can be increased. As a result, when inserting the spigot of the pipe into the socket of the pipe to be joined, the sealing member can be more reliably prevented from being dragged by the spigot.

[0013] In the second configuration described above, the projection of the engaging portion is formed in a curved shape so as to engage with the recess (third configuration).

[0014] In the above configuration, the projection of the engaging portion that engages with the annular recess formed along the circumferential direction on the inner surface of the sealing member is formed in a curved shape so as to engage with the recess. Therefore, the projection can be smoothly engaged with the recess.

[0015] In the first configuration described above, the recess or the protrusion is provided in the portion of the sealing member between the sealing body and the insertion support portion, and the engaging portion is located at the tip of the cover portion of the protective member and engages with the recess or the protrusion (fourth configuration).

[0016] The seal body of the sealing member is compressed radially between the outer circumferential surface of the insertion port and the inner circumferential surface of the receiving port. Therefore, when inserting the insertion port of a pipe into the receiving port of the pipe to be joined, the sealing member is easily dragged by the movement of the insertion port. In the above configuration, the engaging portion located at the tip of the cover portion of the protective member engages with a recess or protrusion provided in the portion of the sealing member between the seal body and the insertion support portion. Thus, the movement of the insertion support portion of the sealing member in the axial direction can be suppressed. This makes it possible to more reliably suppress the axial dragging of the sealing member when the insertion port moves axially relative to the receiving port.

[0017] In the fourth configuration described above, the cover portion has a projection that protrudes radially outward at a position that is on the opening side of the receiving opening relative to the engaging portion and on the opening side of the receiving opening relative to the insertion support portion (fifth configuration).

[0018] In the above configuration, the sealing member has a protruding portion that extends radially outward from a position on the opening side of the receiving port relative to the insertion support portion of the sealing member. Therefore, when the axis of the insertion port is radially off-center relative to the receiving port, the protruding portion abuts against the opening side of the receiving port, thereby preventing damage to the protective member and preventing radial displacement of the protective member.

[0019] In the first configuration described above, the cover portion covers a part of the inner circumferential surface of the seal body portion of the seal member (sixth configuration).

[0020] This allows the insertion end of the pipe into the receiving end of the pipe to be joined without applying lubricant to the sealing body of the sealing member. Therefore, the work of applying lubricant to the sealing body can be omitted, and the work efficiency when joining the insertion end to the receiving end can be improved.

[0021] In the first configuration described above, the insertion support portion is annular, the inner circumferential surface of the insertion support portion is tapered with a smaller inner diameter towards the seal body portion, and the cover portion of the protective member is annular so as to follow the inner circumferential surface of the insertion support portion (seventh configuration).

[0022] The inner peripheral surface of the insertion support portion of the seal member in the above configuration is tapered such that the inner diameter decreases toward the seal body portion. Therefore, the protective member can be easily inserted inward of the seal member along the inner peripheral surface of the insertion support portion. Further, since the cover portion of the protective member is annular so as to follow the inner peripheral surface of the insertion support portion, it has an inner peripheral surface that is tapered such that the inner diameter increases toward the opening side of the receiving port. Therefore, it is easy to discharge foreign matter to the opening side of the receiving port by the cover portion of the protective member.

[0023] In the first configuration, the holding portion is engaged with and held by a flange located on the outer peripheral surface on the opening side of the receiving port (eighth configuration).

[0024] The protective member in the above configuration is engaged with the flange on the opening side of the receiving port. Therefore, axial movement of the protective member can be prevented when inserting the insertion port of the pipe into the receiving port of the mating pipe.

[0025] A protective member according to an embodiment of the present invention includes a holding portion held by a receiving port of a mating pipe joined to an insertion port of a pipe, and from the holding portion, along the inner peripheral surface of an annular seal member that seals between the outer peripheral surface of the insertion port of the pipe and the inner peripheral surface of the receiving port of the mating pipe, and a cover portion that covers and protects at least a part of the inner peripheral surface of the seal member, and the cover portion has an engaging portion on the outer peripheral surface that engages with a concave portion or a convex portion formed on the inner peripheral surface of the seal member (ninth configuration).

[0026] In the above configuration, the protective member has a holding portion held by the receiving port and an engaging portion on the cover portion that engages with a concave portion or a convex portion formed on the inner peripheral surface of the seal member. Thereby, the protective member can suppress the seal member from being dragged to the insertion port when inserting the insertion port of the pipe into the receiving port of the mating pipe.

[0027] Therefore, it is possible to provide a protective member that can suppress the seal member from moving in the axial direction when inserting into the insertion port of the pipe and the receiving port of the mating pipe.

[0028] A sealing member according to one embodiment of the present invention is annular in shape and has a recess or protrusion on its inner circumferential surface that engages with an engaging portion provided on the cover portion of the protective member (10th configuration).

[0029] In the above configuration, the sealing member has a recess or protrusion that engages with an engaging portion provided on the cover portion of the protective member. This prevents the sealing member from being dragged along the opening when the opening of the pipe is inserted into the receiving end of the pipe to be joined, and this can be prevented by the protective member.

[0030] Therefore, it is possible to provide a sealing member that can suppress axial movement of the sealing member when it is inserted into the spigot of the pipe and the socket of the pipe to be joined. [Effects of the Invention]

[0031] A joint structure according to one embodiment of the present invention comprises a pipe slit, a receiving end of a pipe to be joined to the pipe, a sealing member made of an elastic material that seals the space between the outer circumferential surface of the pipe slit and the inner circumferential surface of the receiving end of the pipe to be joined, and a protective member that protects the sealing member. The receiving end has a groove extending in the circumferential direction on its inner circumferential surface, and the sealing member has an annular sealing body portion that is compressed radially by the outer circumferential surface of the slit and the inner circumferential surface of the receiving end, and an insertion support portion that is connected to the opening end of the receiving end of the sealing body portion and is configured to be insertable into the groove of the receiving end. The protective member has a cover portion that covers at least the inner circumferential surface of the insertion support portion of the sealing member, and a holding portion that is connected to the opening end of the receiving end of the cover portion and is held on the opening side of the receiving end. The cover portion has an engaging portion on its outer circumferential surface that engages with a recess or protrusion formed on the inner circumferential surface of the sealing member.

[0032] A protective member according to one embodiment of the present invention has a holding portion that is held at the receiving end of the pipe to be joined, which is joined to the slit of the pipe, and a cover portion that extends from the holding portion along the inner surface of an annular sealing member that seals the space between the outer surface of the slit of the pipe and the inner surface of the receiving end of the pipe to be joined, and covers and protects at least a part of the inner surface of the sealing member, wherein the cover portion has an engaging portion on its outer surface that engages with a recess or protrusion formed on the inner surface of the sealing member.

[0033] A sealing member according to one embodiment of the present invention is annular in shape and has a recess or protrusion on its inner circumferential surface that engages with an engaging portion provided on the cover portion of a protective member.

[0034] This makes it possible to provide a joint structure, protective member, and sealing member that can suppress axial movement of the sealing member when inserting the pipe spigot into the socket of the pipe to be joined. [Brief explanation of the drawing]

[0035] [Figure 1] Figure 1 is an end view showing a schematic configuration of the joint structure according to the first embodiment. [Figure 2] Figure 2 is a partially enlarged end view of Figure 1. [Figure 3] Figure 3 is an end view showing the schematic configuration of the socket. [Figure 4] Figure 4 is a flowchart showing the method of joining the socket and the receptacle. [Figure 5] Figure 5 shows how the sealing member and protective member are attached to the receiving opening. [Figure 6] Figure 6 shows the insertion of the socket into the socket. [Figure 7] Figure 7 shows the state in which the socket is inserted into the socket. [Figure 8] Figure 8 is a partially enlarged view showing the schematic configuration of the joint structure according to the second embodiment. [Figure 9] Figure 9 is a partially enlarged view showing the schematic configuration of the joint structure according to the third embodiment. [Modes for carrying out the invention]

[0036] The following describes each embodiment with reference to the drawings. In each drawing, the same parts are denoted by the same reference numerals, and the description of those parts will not be repeated. Note that the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components or the dimensional ratios of each component.

[0037] Furthermore, in the following explanation, the terms “support,” “connection,” and “holding” (hereinafter referred to as “support, etc.”) include not only cases where members are directly supported, etc., by each other, but also cases where they are supported, etc., through other members. In other words, in the following explanation, the terms “support, etc.” include both direct and indirect support, etc., between members.

[0038] [First Embodiment] (Joint structure) Figure 1 is a cross-sectional view showing the schematic configuration of a joint structure 1 according to the first embodiment of the present invention. Figure 2 is a partially enlarged view of Figure 1. Figure 3 is a cross-sectional view showing the schematic configuration of the socket 2. Figure 5 shows the sealing member 4 and the protective member 5 being attached to the socket 2. Figure 6 shows the insertion opening 3 being inserted into the socket 2. Note that in Figure 6, the gap between the protective member 5 and the sealing member 4 is exaggerated, but in reality, they are in close contact without any gap.

[0039] As shown in Figure 1, the joint structure 1 comprises a socket 3 for the pipe W2, a receiving end 2 for the pipe to be joined W1, a sealing member 4, and a protective member 5. The sealing member 4 seals the space between the inner circumferential surface 21 of the receiving end 2 and the outer circumferential surface 31 of the socket 3.

[0040] The pipes to be joined, W1 and W2, are, for example, water pipes. However, W1 and W2 may be other types of pipes, such as sewer pipes, agricultural water pipes, or gas pipes. W1 and W2 may be ductile cast iron pipes, other metal pipes, or resin pipes.

[0041] As shown in Figure 2, the socket 2 has a lock ring groove 22 and a sealing member groove 23 on its inner circumferential surface 21. The sealing member groove 23 is located on the opening side of the socket 2, relative to the lock ring groove 22.

[0042] The locking ring groove 22 is an annular groove provided around the entire circumference. A locking ring 6 is positioned within the locking ring groove 22. The locking ring 6 positioned within the locking ring groove 22 restricts the insertion end 3 of the pipe W2, which is inserted into the receiving end 2 of the pipe to be joined, from coming out of the receiving end 2. The configuration of the locking ring groove 22 and the locking ring 6 is the same as that of a typical locking ring groove and locking ring. Therefore, a description of the locking ring groove 22 and the locking ring 6 is omitted.

[0043] The sealing member groove 23 is an annular groove extending circumferentially on the inner circumferential surface 21 of the receiving opening 2. The sealing member 4 is positioned within the sealing member groove 23. The sealing member groove 23 has a groove portion 24 into which the insertion support portion 42 of the sealing member 4 can be inserted, a compression projection 25 that protrudes radially inward from the groove portion 24, and a connecting portion 26 that connects the groove portion 24 and the compression projection 25. The insertion support portion 42 of the sealing member 4 is positioned radially inward from the groove portion 24 and the connecting portion 26. The sealing body portion 41 of the sealing member 4 is positioned radially inward from the compression projection 25.

[0044] As shown in Figure 3, the receiving end 2 according to this embodiment has an opening 27 at the end on the opening side. This opening 27 has an inner end surface 27a that connects to the radially inward end on the side surface of the groove 24, and an inclined surface 27b that has an inner diameter that increases from the end on the opening side of the inner end surface 27a toward the opening.

[0045] As shown in Figure 1, the Socket 3 has a Socket projection 32 at its end on the side of the opening 3a. The Socket projection 32 protrudes radially outward from the outer circumferential surface 31 of the Socket 3. When the pipe to be joined W1 and pipe W2 are joined, the Socket projection 32 of pipe W2 is located on the opposite side of the axial direction from the opening of the receiving port 2 with respect to the lock ring 6 attached to the inner circumferential surface 21 of the receiving port 2 of the pipe to be joined W1. The Socket projection 32 comes into contact with the lock ring 6 when pipe W2 moves axially toward the opening side of the pipe to be joined W1. This prevents the Socket 3 from coming out of the receiving port 2.

[0046] (Configuration of sealing member) The sealing member 4 is positioned between the inner circumferential surface 21 of the receiving opening 2 and the outer circumferential surface 31 of the insertion opening 3. More specifically, as shown in Figure 2, the sealing member 4 is positioned within a sealing member groove 23 provided on the inner circumferential surface 21 of the receiving opening 2. The sealing member 4 seals the space between the inner circumferential surface 21 of the receiving opening 2 and the outer circumferential surface 31 of the insertion opening 3.

[0047] The sealing member 4 has a sealing body portion 41 and an insertion support portion 42. The sealing member 4 is made of an annular elastic member. As shown in Figure 2, the sealing body portion 41 is configured to be positioned radially inward of the compression projection 25 of the receiving opening 2. The insertion support portion 42 is configured to be positioned radially inward of the groove portion 24 and the connecting portion 26 of the receiving opening 2. The sealing member 4 is an annular member in which the axis of the sealing member 4 and the axis P of the pipe to be joined W1 coincide or are parallel.

[0048] The seal body portion 41 is made of an elastic material such as rubber. As shown in Figure 5, the seal body portion 41 has a seal bulge portion 411 that bulges radially inward in its cross-sectional shape, and a seal outer circumference portion 412 that follows the compression projection portion 25 that extends in the axial direction of the pipe W1 to be joined.

[0049] The seal body 41, which is made of an elastic material, is elastically deformable. Therefore, when the insertion port 3 of the pipe W2 is inserted into the receiving port 2 of the pipe to be joined, with the seal member 4 positioned radially inward of the compression projection 25 of the seal member groove 23, the seal body 41 is compressed radially by the inner circumferential surface 21 of the receiving port 2 and the outer circumferential surface 31 of the insertion port 3 (see Figure 2). In other words, the compressed seal body 41 is positioned radially inward of the compression projection 25. The compressed seal body 41 seals the space between the inner circumferential surface 21 of the receiving port 2 and the outer circumferential surface 31 of the insertion port 3.

[0050] As shown in Figure 2, the insertion support portion 42 has a tapered portion 421a located radially inward and an outer peripheral portion 421b located radially outward. The insertion support portion 42 is connected to the opening end of the receiving port 2 in the seal body portion 41. A recess 421c is formed at the connection point between the insertion support portion 42 and the seal bulge portion 411 of the seal body portion 41, radially inward. The recess 421c is formed by recessing a part of the inner circumferential surface of the seal body portion 41 and a part of the inner circumferential surface of the insertion support portion 42 radially outward.

[0051] The tapered portion 421a, which is the inner circumferential surface of the insertion support portion 42, has a tapered shape in which the inner diameter decreases as it approaches the seal body portion 41. The cover portion 51 of the protective member 5 is in contact with this tapered portion 421a.

[0052] The insertion support portion 42 has an annular projection 422 extending radially outward at the opening end of the socket 2. The annular projection 422 is configured to be insertable into the groove 24. The insertion support portion 42, which is made of an elastic material, is elastically deformable. When inserting the socket 3 of the pipe W2 into the socket 2 of the pipe to be joined, as shown in Figure 7, the insertion support portion 42 is compressed radially by the inner circumferential surface 21 of the socket 2 and the cover portion 51 of the protective member 5, which will be described later and receives a radially outward force from the outer circumferential surface 31 of the socket 3, and the annular projection 422 moves radially outward within the groove 24.

[0053] (Configuration of the protective member according to the first embodiment) As shown in Figure 1, the protective member 5 has a cover portion 51 and a holding portion 52. The protective member 5 is made of an annular resin member. The cover portion 51 covers at least the inner circumferential surface of the insertion support portion 42 of the sealing member 4. The holding portion 52 is held in the receiving end 2 of the pipe to be joined W1.

[0054] As shown in Figure 2, the holding portion 52 in this embodiment is supported by engaging with a flange 28 located on the outer peripheral surface of the opening side of the receiving end 2 of the pipe W1 to be joined. The holding portion 52 has a U-shaped bent portion 52a that bends to cover the flange 28, and a receiving end surface covering portion 52b that extends radially inward from the opening side of the bent portion 52a to cover the opening end surface of the receiving end 2 and is connected to the opening side of the cover portion 51. The inner peripheral surface of the cover portion 51 is tapered, with the inner diameter decreasing from the receiving end surface covering portion 52b towards the tip.

[0055] The cover portion 51 extends along the inclined surface 27b of the opening 27 and continues to extend axially and radially along the inner circumferential surface of the tapered portion 421a of the insertion support portion 42 of the seal member 4, forming an annular shape. This cover portion 51 extends from the holding portion 52 along the inner circumferential surface of the insertion support portion 42 of the seal member 4, covering at least the insertion support portion 42 of the seal member 4 and covering the recess 421c formed on the inner circumferential surface of the seal body portion 41. In other words, the cover portion 51 covers from the opening side of the receiving port 2 in the insertion support portion 42 of the seal member 4 to the base end of the seal body portion 41.

[0056] The cover portion 51 has a base portion 511, a projection portion 514, and an extension portion 513. The base portion 511 has a tapered shape that follows the inclined surface 27b of the opening 27. The projection portion 514 protrudes radially outward from the tip of the base portion 511 and faces the inner end surface 27a of the opening 27. This projection portion 514 protrudes radially outward at a position that is closer to the opening of the receiving opening 2 than the engaging portion 51b of the extension portion 513 (described later) and closer to the opening of the receiving opening 2 than the insertion support portion 42. The extension portion 513 extends from the base portion 511 along the tapered portion 421a of the sealing member 4. The extension portion 513 has a smaller outer diameter than the base portion 511 and the projection portion 514.

[0057] As shown in Figure 2, the extension portion 513 has an engaging portion 51b that protrudes radially outward at its tip. This engaging portion 51b is a projection that engages with a recess 421c formed in an annular shape in the circumferential direction. That is, the cover portion 51 according to this embodiment has an engaging portion 51b on its outer circumferential surface that engages with the recess 421c formed on the inner circumferential surface of the insertion support portion 42 of the seal member 4 and the inner circumferential surface of the seal body portion 41. Specifically, the engaging portion 51b is provided at the tip portion of the extension portion 513 of the cover portion 51 and is in contact with the portion between the seal body portion 41 and the engaging portion 51b related to the seal member 4. In this embodiment, the engaging portion 51b is formed in a curved shape so as to engage with the recess 421c.

[0058] (Method of joining the socket and the receiving end) Next, with reference to Figures 4 to 7, a method for joining the insertion port 3 and the receiving port 2, to which the protective member 5 is attached, will be described. Figure 4 is a flowchart showing the method for joining the insertion port 3 and the receiving port 2. Figures 5 to 7 are diagrams schematically illustrating the method for attaching the joint structure 1.

[0059] As shown in Figure 4, the method for joining the insertion port 3 and the receiving port 2 includes a sealing member placement step S1, a protective member placement step S2, a cleaning step S3, and an insertion port insertion step S4.

[0060] The sealing member placement step S1 is the step of placing the sealing member 4 on the inner circumferential surface 21 of the receiving opening 2. Specifically, in the sealing member placement step S1, as shown in Figures 5 and 6, the sealing member 4 is inserted through the opening of the receiving opening 2 with the insertion support portion 42 bent radially inward so that it is engaged with the groove portion 24, and placed on the inner circumferential surface 21 of the receiving opening 2.

[0061] The protective member placement step S2 is the step of placing the cover portion 51 of the protective member 5 on the inner circumferential surface of the sealing member 4. Specifically, in the protective member placement step S2, as shown in Figures 5 and 6, the holding portion 52 of the protective member 5 is brought into contact with the flange 28 on the opening side of the receiving port 2, and the cover portion 51 of the protective member 5 is brought into contact with the inclined surface 27b of the opening 27, and is inserted from the opening of the receiving port 2 to be placed on the inner circumferential surface of the sealing member 4.

[0062] When the retaining portion 52 of the protective member 5 is brought into contact with the flange 28, the inclined surface at the tip of the bent portion 52a expands in diameter along the inclined surface of the outer circumference of the flange 28, then returns to its original shape and the retaining portion 52 engages with the flange 28. When the cover portion 51 of the protective member 5 is brought into contact with the inclined surface 27b of the opening 27, the engaging portion 51b contacts the inclined surface 27b and moves radially inward, sliding on the inner circumference of the insertion support portion 42 of the seal member 4, after which the engaging portion 51b engages with the recess 421c, and the protruding portion 514 is adjacent to the opening side of the receiving port 2 in the seal member 4.

[0063] As shown by the dotted line in Figure 6, the cleaning step S3 is a process of cleaning the outer surface 31 of the insertion end 3 of the pipe W2 with water before inserting it into the receiving end 2 of the pipe to be joined W1. When lowering the pipe W2 into the excavated trench or after it has been lowered, foreign matter G such as soil and sand adheres to the insertion end 3, so the outer surface 31 of the insertion end 3 is cleaned with water. Specifically, in the cleaning step S3, water is sprayed onto the outer surface 31 of the insertion end 3 of the pipe W2 placed in the excavated trench to clean it. Note that the cleaning step S3 may be omitted.

[0064] On the other hand, since the sealing member 4 is protected by the cover portion 51 of the protective member 5, the adhesion of foreign matter G is suppressed. Furthermore, since the protective member 5 is annular in shape with an outer circumferential surface that follows the tapered portion 421a of the sealing member 4, foreign matter G can be easily discharged to the opening side of the receiving port 2. For this reason, in this embodiment, the inner circumferential surface of the sealing member 4 is not cleaned.

[0065] The insertion step S4 is the step of inserting the insertion port 3 into the receiving port 2. Figure 6 shows the insertion of the insertion port 3 into the receiving port 2. Figure 7 shows the insertion of the insertion port 3 into the receiving port 2. As shown in Figure 6, the insertion port 3 is inserted into the receiving port 2 while the receiving port end face covering portion 52b of the protective member 5 is pressed against the opening end face of the opening 27 of the receiving port 2 by the holding jig T. This prevents the protective member 5 from shifting position. If the protective member 5 does shift position, it is highly likely that the sealing member 4 has shifted position, and therefore it can be determined that there is a construction defect.

[0066] When the insertion port 3 is inserted into the receiving port 2, as shown in Figure 7, the tip of the cover portion 51 of the protective member 5 moves radially outward, and the seal body portion 41 is compressed radially by the inner circumferential surface 21 of the receiving port 2 and the outer circumferential surface 31 of the insertion port 3. As a result, the space between the inner circumferential surface 21 of the receiving port 2 and the outer circumferential surface 31 of the insertion port 3 is sealed.

[0067] In this embodiment, the holding portion 52 of the protective member 5 is held on the opening side of the receiving port 2, and the cover portion 51 has an engaging portion 51b that engages with a recess 421c or protrusion formed on the inner circumferential surface of the sealing member 4. As a result, the protective member 5 can prevent the sealing member 4 from being dragged by the insertion port 3 when the insertion port 3 of the pipe W2 is inserted into the receiving port 2 of the pipe to be joined W1.

[0068] The protective member 5 according to the embodiment of the present invention having the above configuration includes a holding portion 52 that is held by the receiving end 2 of the pipe to be joined W1 which is joined to the insertion end 3 of the pipe W2, and a cover portion 51 that extends from the holding portion 52 along the inner surface of an annular sealing member 4 that seals the space between the outer surface 31 of the insertion end 3 of the pipe W2 and the inner surface 21 of the receiving end 2 of the pipe to be joined W1, and covers and protects at least a part of the sealing member 4, and the cover portion 51 has an engaging portion 51b on its outer surface that engages with a recess 421c or a protrusion formed on the inner surface of the sealing member 4.

[0069] The protective member 5 has a holding portion 52 that is held by the receiving end 2, and a cover portion 51 that has an engaging portion 51b that engages with a recess 421c or protrusion formed on the inner circumferential surface of the sealing member 4. This prevents the sealing member 4 from being dragged by the receiving end 3 when the insertion end 3 of the pipe W2 is inserted into the receiving end 2 of the pipe to be joined W1.

[0070] Therefore, when inserting the insertion port 3 of pipe W2 into the receiving port 2 of pipe W1 to be joined, a protective member 5 is provided that can suppress the axial movement of the sealing member 4.

[0071] The sealing member 4 according to the embodiment of the present invention having the above configuration is annular and has a recess 421c or a protrusion on its inner circumferential surface that engages with an engaging portion 51b provided on the cover portion 51 of the protective member 5.

[0072] The sealing member 4 has a recess 421c or a protrusion that engages with an engaging portion 51b provided on the cover portion 51 of the protective member 5. This prevents the sealing member 4 from being dragged by the insertion opening 3 when the insertion opening 3 of the pipe W2 is inserted into the receiving opening 2 of the pipe to be joined, and this can be prevented by the protective member 5.

[0073] Therefore, when inserting the insertion port 3 of pipe W2 into the receiving port 2 of pipe W1 to be joined, it is possible to provide a sealing member 4 that can suppress the axial movement of the sealing member 4.

[0074] The engaging portion 51b of the protective member 5 has a projection that engages with a recess 421c formed in an annular shape along the circumferential direction on the inner circumferential surface of the insertion support portion 42 of the sealing member 4. Therefore, the engagement force between the sealing member 4 and the protective member 5 can be increased. As a result, when the insertion opening 3 moves axially relative to the receiving opening 2, the axial dragging of the sealing member 4 can be more reliably suppressed.

[0075] The projection of the engaging portion 51b, which engages with the annular recess 421c formed along the circumferential direction on the inner surface of the sealing member 4, is formed in a curved shape so as to engage with the recess 421c. Therefore, the projection can be smoothly engaged with the recess 421c.

[0076] The seal body portion 41 of the seal member 4 is compressed radially by the outer circumferential surface 31 of the insertion port 3 and the inner circumferential surface 21 of the receiving port 2. Therefore, when inserting the insertion port 3 of the pipe W2 into the receiving port 2 of the pipe to be joined W1, the seal member 4 is easily dragged by the movement of the insertion port 3. In the above embodiment, the engaging portion 51b located at the tip of the cover portion 51 of the protective member 5 engages with a recess 421c or a protrusion provided in the portion of the seal member 4 between the seal body portion 41 and the insertion support portion 42. Therefore, the insertion support portion 42 of the seal member 4 can be prevented from moving in the axial direction. This makes it possible to more reliably prevent the seal member 4 from being dragged when the insertion port 3 moves in the axial direction.

[0077] The sealing member 4 has a protruding portion 514 that extends radially outward from a position on the opening side of the receiving port 2 relative to the insertion support portion 42 of the sealing member 4. Therefore, when the axis of the insertion port 3 relative to the receiving port 2 shifts to one side, the protruding portion 514 abuts against the opening side of the receiving port 2, thereby preventing damage to the protective member 5 and preventing radial displacement of the protective member 5.

[0078] The cover portion 51 covers a portion of the inner circumferential surface of the seal body portion 41 of the seal member 4. This allows the insertion port 3 of the pipe W2 to be inserted into the receiving port 2 of the pipe to be joined without applying lubricant to the seal body portion 41 of the seal member 4. Therefore, the work of applying lubricant to the seal body portion 41 of the seal member 4 can be omitted, improving the work efficiency when joining the insertion port 3 of the pipe W2 to the receiving port 2 of the pipe to be joined. Note that water may be used instead of lubricant when joining the pipe W2 and the pipe to be joined W1. By using water, the insertion port 3 of the pipe W2 becomes easier to insert into the receiving port 2 of the pipe to be joined W1, thus improving the work efficiency of joining the pipe W2 and the pipe to be joined W1.

[0079] The inner circumferential surface of the insertion support portion 42 of the sealing member 4 is tapered, with the inner diameter decreasing towards the sealing body portion 41. Therefore, the protective member 5 can be easily inserted into the sealing member 4 along its inner circumferential surface. Furthermore, the cover portion 51 of the protective member 5 is annular in shape, following the inner circumferential surface of the insertion support portion 42 of the sealing member 4, and has a tapered inner circumferential surface with an inner diameter increasing towards the opening side of the receiving port 2. Therefore, the cover portion 51 of the protective member 5 facilitates the discharge of foreign matter G to the opening side of the receiving port 2.

[0080] In the first embodiment, the protective member 5 engages with the flange 28 on the opening side of the receiving port 2. Therefore, when inserting the insertion port 3 of the pipe W2 into the receiving port 2 of the pipe to be joined, axial movement of the protective member 5 can be prevented.

[0081] (Modified example of the protective member according to the first embodiment) Although not shown in the figures, instead of the recess 421c formed on the inner circumferential surface of the insertion support portion 42 of the sealing member 4, a protrusion projecting radially inward may be formed on the inner circumferential surface of the insertion support portion 42. In this case, a concave engaging portion is formed on the outer circumferential surface of the cover portion 51 to engage with the protrusion. In this modified example, the protrusion is formed in a curved shape so as to engage with the concave engaging portion.

[0082] [Second Embodiment] Figure 8 shows a protective member 5A according to the second embodiment. As shown in Figure 8, the protective member 5A according to this embodiment differs from the first embodiment in that the holding portion 52A does not have a U-shaped bent portion 52a that bends to cover the flange 28 on the opening side of the receiving port 2 shown in Figure 2. Components similar to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and only the differences will be described below.

[0083] The retaining portion 52A of the protective member 5A has a receiving end surface covering portion 52Ab that extends radially inward so as to cover the opening end surface of the opening 27 of the receiving port 2. The protective member 5A is held on the opening side of the receiving port 2 by the retaining portion 52A of the protective member 5A contacting the opening end surface of the opening 27 of the receiving port 2. In addition, the engaging portion 51Ab of the protective member 5A in this embodiment is provided in multiple locations in the axial direction (two in this embodiment). Corresponding to these multiple engaging portions 51Ab, the sealing member 4A has multiple recesses 421Ac formed on its inner circumferential surface. In Figure 8, reference numeral 41A denotes the seal body portion.

[0084] [Third Embodiment] Figure 9 shows a protective member 5B according to the third embodiment. As shown in Figure 9, the protective member 5B according to this embodiment differs from the first embodiment in that it has a retaining portion 52B that is sandwiched between a sealing member groove 23 formed on the inner circumferential surface 21 of the receiving opening 2 and the sealing member 4B. Components similar to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and only the differences will be described below.

[0085] The insertion support portion 42B of the sealing member 4B is provided with a notch 42C cut out on the opening side, into which the holding portion 52B of the protective member 5B fits. The holding portion 52B of the protective member 5B rises vertically from the opening side end of the receiving port 2 in the extension portion 513B and is held on the opening side of the receiving port 2 of the pipe to be joined W1. In addition, multiple engaging portions 51Bb are provided in the axial direction (two in this embodiment). Corresponding to these multiple engaging portions 51Bb, multiple recesses 421Bc are formed on the inner circumferential surface of the sealing member 4B. In Figure 9, reference numeral 41B denotes the seal body portion.

[0086] (Modified examples of protective members according to the second and third embodiments) Although not shown in the figures, similar to the modification of the first embodiment, instead of the recesses 421Ac and 421Bc formed on the inner circumferential surfaces of the insertion support portions 42A and 42B of the sealing members 4A and 4B, protrusions projecting radially inward may be formed on the inner circumferential surfaces of the insertion support portions 42A and 42B. In this case, a concave engaging portion is formed on the outer circumferential surface of the cover portions 51A and 51B to engage with the protrusion. In this modification, the protrusion is formed in a curved shape, for example, to engage with the concave engaging portion.

[0087] As described above, the holding portions 52, 52A, and 52B of the protective members 5, 5A, and 5B are held on the opening side of the receiving port 2, and the cover portions 51, 51A, and 51B have engaging portions 51b, 51Ab, and 51Bb that engage with recesses 421c, 421Ac, and 421Bc or protrusions formed on the inner circumferential surface of the sealing members 4, 4A, and 4B. This prevents the sealing members 4, 4A, and 4B from being dragged by the insertion port 3 of the pipe W2 when the insertion port 3 of the pipe to be joined into the receiving port 2 of the pipe W1, and the protective members 5, 5A, and 5B can prevent this. Therefore, a joint structure 1 can be provided that can prevent the sealing members 4, 4A, and 4B from moving axially when the insertion port 3 of the pipe W2 is inserted into the receiving port 2 of the pipe to be joined.

[0088] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0089] In the above embodiment, the groove 23 for the sealing member has a connecting portion 26 on the inner circumferential surface 21 of the receiving opening 2. However, the groove for the sealing member does not have to have a connecting portion. In this case, the groove for the sealing member may have only a groove portion and a compression projection portion. In this case, the insertion support portion for the sealing member is composed only of an annular projection.

[0090] In the above embodiment, the insertion support portion 42 of the seal member 4 has a tapered portion 421a connected to the seal bulge portion 411 of the seal body portion 41 on its radially inward side. However, the insertion support portion does not have to have a tapered portion. In this case, the inner circumferential surface of the insertion support portion may be a surface aligned with the axial direction of the pipe to be joined.

[0091] In the above embodiment, the opening 27 of the socket 2 has an inclined surface 27b on its inner circumferential surface. However, the socket does not have to have an inclined surface. In this case, the inner circumferential surface of the socket may be a surface aligned with the axial direction of the pipe to be joined. In this case, the cover portion may extend along the axial direction of the pipe to be joined, or it may extend in a tapered shape.

[0092] In the above embodiment, the outer circumferential surface of the cover portion 51 has a curved engaging portion 51b that engages with a recess 421c formed on the inner circumferential surface of the insertion support portion 42 of the seal member 4. However, the engaging portion may be polygonal in shape, and the shape of the engaging portion is not particularly limited. Also, in the above embodiment, the engaging portion 51b is provided at the tip of the extension portion 513 of the cover portion 51. However, the engaging portion may be provided in the middle portion of the extension portion of the cover portion, etc., and the location of placement is not particularly limited as long as it is in a position where it can engage with the seal member.

[0093] In the above embodiment, a recess 421c or a protrusion is formed on the inner circumferential surface of the insertion support portion 42 of the sealing member 4, and an engaging portion 51b that engages with the recess 421c or the protrusion is formed on the inner circumferential surface of the insertion support portion 42 of the protective member 5. However, the engaging portion may be provided around the entire inner circumferential surface of the annular protective member, or it may be provided on a portion of the inner circumferential surface of the protective member. When the engaging portion is provided on a portion of the inner circumferential surface of the protective member, it is preferable that it is composed of a plurality of protrusions arranged at equal intervals along the circumferential direction. [Industrial applicability]

[0094] The present invention can be used in a joint structure comprising a pipe socket, a receiving end of a pipe to be joined to the pipe, and an annular sealing member that seals the space between the outer circumferential surface of the pipe socket and the inner circumferential surface of the pipe to be joined. [Explanation of symbols]

[0095] 1. Joint structure 2 socket 3. Insertion port 4, 4A, 4B sealing members 5, 5A, 5B Protective components 6 lock rings 21 Inner surface 22 grooves for lock rings 23 Grooves for sealing members 24 grooves 25 Compression protrusion 26 Connection part 27 Opening 27a Inner end surface 27b Slope 28 Flange 31 Outer surface 41, 41A, 41B Seal body 42, 42A, 42B Insertion support section 42C Notch 51, 51A, 51B Cover section 51b, 51Ab, 51Bb engaging part 52, 52A, 52B holding part 52a Bend part 52b, 52Ab Socket end cover part 411 Seal bulge 412 Outer circumference of seal 421a Tapered section 421b outer periphery 421c, 421Ac, 421Bc recess 422 Annular projection 513, 513B extension part 514 Protrusion W1 Joined pipe W2 tube

Claims

1. The opening of the tube, The receiving end of the pipe to be joined to the aforementioned pipe, A sealing member made of an elastic material seals the space between the outer circumferential surface of the insertion opening of the aforementioned pipe and the inner circumferential surface of the receiving opening of the pipe to be joined, A protective member that protects the sealing member, Equipped with, The aforementioned socket is, The inner surface has grooves that extend in the circumferential direction, The sealing member is An annular seal body portion that is compressed radially by the outer circumferential surface of the insertion opening and the inner circumferential surface of the receiving opening, The seal body portion includes an insertion support portion that is connected to the opening end of the receiving port and is configured to be insertable into the groove of the receiving port, The protective member is The sealing member comprises a cover portion that covers at least the inner circumferential surface of the insertion support portion, A holding portion connected to the opening end of the receiving opening in the cover portion and held on the opening side of the receiving opening, It has, The aforementioned cover portion is The outer circumferential surface has an engaging portion that engages with a recess or protrusion formed on the inner circumferential surface of the sealing member, Joint structure.

2. In the joint structure described in claim 1, The aforementioned recess is The sealing member is formed in an annular shape along the circumferential direction on its inner circumferential surface, The aforementioned engaging portion is Having a projection that engages with the recess, Joint structure.

3. In the joint structure described in claim 2, The projection of the engaging portion is formed in a curved shape so as to engage with the recess. Joint structure.

4. In the joint structure described in claim 1, The recess or the protrusion is The portion of the sealing member between the sealing body and the insertion support portion is provided, The aforementioned engaging portion is Located at the tip of the cover portion of the protective member, and engaged with the recess or the protrusion, Joint structure.

5. In the joint structure described in claim 4, The aforementioned cover portion is It has a projection that protrudes radially outward at a position that is on the opening side of the receiving opening relative to the engaging portion and on the opening side of the receiving opening relative to the insertion support portion. Joint structure.

6. In the joint structure described in claim 1, The cover portion covers a part of the inner circumferential surface of the seal body portion of the seal member. Joint structure.

7. In the joint structure described in claim 1, The aforementioned insertion support portion is annular, The inner circumferential surface of the insertion support portion is The seal body has a tapered shape, with the inner diameter becoming smaller towards the seal body. The cover portion of the protective member is The insertion support portion is annular in shape, along the inner circumferential surface. Joint structure.

8. In the joint structure described in claim 1, The retaining portion is held by engaging with a flange located on the outer peripheral surface of the opening side of the receiving port. Joint structure.

9. A retaining part that is held at the receiving end of the pipe to be joined, which is connected to the insertion end of the pipe, Extending from the holding portion along the inner surface of an annular sealing member that seals the space between the outer surface of the insertion opening of the pipe and the inner surface of the receiving opening of the pipe to be joined, a cover portion covers and protects at least a portion of the inner surface of the sealing member, It has, The aforementioned cover portion is The outer circumferential surface has an engaging portion that engages with a recess or protrusion formed on the inner circumferential surface of the sealing member, Protective material.

10. It is annular in shape and has a recess or protrusion on its inner circumferential surface that engages with an engaging portion provided on the cover portion of the protective member. Sealing component.

Images