Joint structure and protective member

Abstract

The present invention provides a joint structure that allows insertion of a pipe spigot into a pipe socket while preventing foreign matter from adhering to the surface of the sealing member, in which a sealing member seals the space between a pipe spigot and a pipe socket 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 of the sealing member 4.

Description

Technical Field

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

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 circumferential surface of a rubber ring arrangement recess of a receiving port, and a valve portion that is compressed between the circumferential 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, the joining of pipes has been carried out manually by workers entering an excavation trench. Therefore, from the viewpoints of cost reduction, construction period shortening, stabilization of construction quality, and improvement of construction safety, automation of pipe joining is required.

[0005] When the worker enters the excavation trench to perform the manual work, before joining the joined pipe to the pipe, cleaning work of a rubber ring or an insertion port attached in the receiving port in the excavation trench is required. This is because when the pipe and the joined pipe are suspended in the excavation trench or after being suspended, foreign matters such as earth and sand may adhere to the rubber ring in the receiving port or the insertion port.

[0006] If this cleaning procedure is not performed, foreign matter may adhere to the rubber ring and the insertion port inside the socket, potentially causing cracks to form on the surface of the rubber ring when the insertion port is inserted into the socket, leading to water leakage. Therefore, in order to automate the pipe joining process, there is a need for a joint structure that can prevent foreign matter from adhering to the rubber ring without performing a cleaning procedure in the excavated trench, and that allows the insertion port to be inserted into the socket while preventing foreign matter from adhering to the rubber ring.

[0007] The object of the present invention is to provide a joint structure and protective member that seals the space between the spigot of a pipe and the socket of a pipe to be joined, while preventing foreign matter from adhering to the surface of the sealing member, and allowing the spigot to be inserted into the socket. [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, wherein the receiving end has a groove extending in the circumferential direction on its inner circumferential surface, 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, and the protective member has a cover portion that covers at least the inner circumferential surface of the insertion support portion of the sealing member (first configuration).

[0009] In the above configuration, the cover portion of the protective member covers at least the inner circumferential surface of the insertion support portion of the sealing member. This prevents foreign matter from adhering to the inner circumferential surface of the insertion support portion of the sealing member. Therefore, it is possible to prevent cracks from occurring on the surface of the sealing member when the slit of the pipe is inserted into the socket of the pipe to be joined. Furthermore, the seal body portion, which is compressed by the outer circumferential surface of the slit and the inner circumferential surface of the socket, is not covered by the protective member. Therefore, the seal body portion can be compressed radially without being obstructed by the protective member. Moreover, the protective member covers the inner circumferential surface of the insertion support portion of the sealing member. Therefore, the insertion support portion can be protected.

[0010] Therefore, in a sealing member that seals the space between the spigot of a pipe and the socket of a pipe to be joined, it is possible to provide a joint structure that allows the spigot to be inserted into the socket while preventing foreign matter from adhering to the surface of the sealing member.

[0011] 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 (second configuration).

[0012] This allows the pipe's insertion end to be inserted into the receiving end of the pipe to be joined without applying lubricant to the sealing body of the sealing member. Therefore, the process of applying lubricant to the sealing body of the sealing member can be omitted, improving the work efficiency when joining the pipe's insertion end to the receiving end of the pipe to be joined.

[0013] 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 (third configuration).

[0014] In the above configuration, the inner circumferential surface of the insertion support portion of the sealing member is tapered, with the inner diameter decreasing towards the sealing body portion. Therefore, the protective member can be easily inserted into the sealing member along the inner circumferential surface of the insertion support portion. Furthermore, since the cover portion of the protective member is annular in shape and follows the inner circumferential surface of the insertion support portion, it has a tapered inner circumferential surface with the inner diameter increasing towards the opening side of the receiving port. The cover portion of the protective member facilitates the discharge of foreign matter to the opening side of the receiving port.

[0015] In any one of the first to third configurations described above, the protective member has a retaining portion that engages with and is held by a flange located on the outer circumference of the opening side of the receiving port (fourth configuration).

[0016] In the above configuration, the protective member engages with the flange on the opening side of the socket. Therefore, when inserting the spigot of the pipe into the socket of the pipe to be joined, axial movement of the protective member can be prevented. This makes it possible to more reliably prevent foreign matter from adhering to the sealing member by the protective member.

[0017] In the fourth configuration described above, the inner circumferential surface of the opening of the socket has an inclined surface whose inner diameter increases towards the opening of the socket, and the cover portion extends axially and radially along the inclined surface (fifth configuration).

[0018] In the above configuration, the inner circumferential surface of the opening of the receiving port has an inclined surface whose inner diameter increases towards the opening. Therefore, the protective member can be easily inserted into the opening along the inner circumferential surface of the opening of the receiving port. Furthermore, the cover portion extends axially and radially along the inclined surface. Therefore, foreign matter can be easily discharged to the opening side of the receiving port.

[0019] 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 spigot 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 spigot 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 (sixth configuration).

[0020] The protective member in the above configuration has a cover portion that extends from the holding portion along the inner circumferential surface of the sealing member and covers and protects at least a portion of the inner circumferential surface of the sealing member. This prevents foreign matter from adhering to the inner circumferential surface of the sealing member by the cover portion of the protective member. Therefore, it is possible to prevent cracks from occurring on the surface of the sealing member when the spigot of the pipe is inserted into the socket of the pipe to be joined.

[0021] Therefore, in a sealing member that seals the space between the spigot of a pipe and the socket of a pipe to be joined, it is possible to provide a protective member that prevents foreign matter from adhering to the surface of the sealing member while allowing the spigot to be inserted into the socket.

[0022] In the sixth configuration described above, the holding portion has a bent portion that bends to cover a flange located on the outer peripheral surface on the opening side of the receiving port, and a receiving port end face covering portion that extends radially inward from the opening side of the receiving port in the bent portion to cover the opening end face of the receiving port and is connected to the opening side of the receiving port in the cover portion (seventh configuration).

[0023] The holding portion of the protective member in the above configuration has a bent portion that bends to cover the flange. Therefore, the movement of the protective member can be prevented when inserting the slit of the pipe into the socket of the pipe to be joined. Furthermore, the protective member has a socket end face covering portion that extends radially inward from the opening side of the socket at the bent portion and covers the opening end face of the socket. Therefore, it can be easily positioned relative to the opening end face of the socket, and the movement of the protective member can be more reliably prevented when inserting the slit of the pipe into the socket of the pipe to be joined.

[0024] In the seventh configuration, the inner peripheral surface of the cover portion has a tapered shape with a smaller inner diameter toward the tip from the receiving port end surface covering portion (eighth configuration).

[0025] In the above configuration, the inner peripheral surface of the cover portion has a tapered shape with a smaller inner diameter toward the tip from the receiving port end surface covering portion. Therefore, the protective member can be easily inserted inward along the inner peripheral surface of the seal member. Further, since the inner diameter of the protective member increases toward the receiving port end surface covering portion, it is easy to discharge foreign matter to the opening side of the receiving port.

Effect of the Invention

[0026] The joint structure according to an embodiment of the present invention includes an insertion port of a pipe, a receiving port of a joined pipe joined to the pipe, a seal member configured by an elastic member for sealing between the outer peripheral surface of the insertion port of the pipe and the inner peripheral surface of the receiving port of the joined pipe, and a protective member for protecting the seal member. The receiving port has a groove portion extending in the circumferential direction on the inner peripheral surface, and the seal member has an annular seal main body portion compressed in the radial direction by the outer peripheral surface of the insertion port and the inner peripheral surface of the receiving port, and an insertion support portion connected to an end portion on the opening side of the receiving port in the seal main body portion and configured to be insertable into the groove portion of the receiving port. The protective member has a cover portion covering at least the inner peripheral surface of the insertion support portion of the seal member.

[0027] The protective member according to an embodiment of the present invention has a holding portion held by a receiving port of a joined pipe joined to an insertion port of a pipe, and a cover portion extending 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 joined pipe from the holding portion and covering and protecting at least a part of the inner peripheral surface of the seal member.

[0028] Thereby, in a seal member that seals between an insertion port of a pipe and a receiving port of a joined pipe, it is possible to provide a joint structure and a protective member that can prevent foreign matter from adhering to the surface of the seal member and allow the insertion port to be inserted into the receiving port.

Brief Description of the Drawings

[0029] [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 a joint structure according to a first modified example of the first embodiment. [Figure 9] Figure 9 is a partially enlarged view showing the schematic configuration of the joint structure according to the second embodiment. [Figure 10] Figure 10 is a partially enlarged view showing the schematic configuration of the joint structure according to the third embodiment. [Modes for carrying out the invention]

[0030] 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.

[0031] 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.

[0032] [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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] (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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] (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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] (Method of joining the socket and the receiving end) Next, with reference to Figures 4 to 7, a method for joining the Socket and the Receptacle to which the protective member 5 is attached will be described. Figure 4 is a flowchart showing the method for joining the Socket and the Receptacle. Figures 5 to 7 are diagrams illustrating the method for attaching the joint structure 1.

[0053] As shown in Figure 4, the method for joining the insertion port and the receiving port includes a sealing member placement step S1, a protective member placement step S2, a cleaning step S3, and an insertion port insertion step S4.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] In this embodiment, the cover portion 51 of the protective member 5 prevents foreign matter G from adhering to the surface of the sealing member 4. Therefore, when the insertion port 3 of the pipe W2 is inserted into the receiving port 2 of the pipe to be joined, it is possible to prevent cracks from occurring on the surface of the sealing member 4. Furthermore, the seal body portion 41, which is compressed by the outer circumferential surface 31 of the insertion port 3 and the inner circumferential surface 21 of the receiving port 2, does not have a cover portion 51. Therefore, the seal body portion 41 can be compressed radially without being obstructed by the protective member 5. Moreover, since the protective member 5 covers the area of ​​the sealing member 4 up to the seal body portion 41, it is possible to protect the area of ​​the sealing member 4 that is prone to foreign matter G adhering to it.

[0062] 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.

[0063] The protective member 5 has a cover portion 51 that extends from the holding portion 52 along the inner circumferential surface of the sealing member 4 and covers and protects at least a part of the sealing member 4. This prevents foreign matter G from adhering to the inner circumferential surface of the sealing member 4. Therefore, when inserting the insertion port 3 of the pipe W2 into the receiving port 2 of the pipe to be joined, it is possible to prevent cracks from occurring on the surface of the sealing member 4.

[0064] Therefore, in a sealing member 4 that seals the space between the insertion port 3 of pipe W2 and the receiving port 2 of the pipe to be joined W1, a protective member 5 can be provided that prevents foreign matter G from adhering to the surface of the sealing member 4 while allowing the insertion port 3 to be inserted into the receiving port 2.

[0065] 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.

[0066] 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. This cover portion 51 of the protective member 5 makes it easy to discharge foreign matter G towards the opening side of the receiving port 2.

[0067] The opening 27 of the receiving port 2 has an inclined surface 27b on its inner circumferential surface, with an inner diameter that increases towards the opening of the receiving port 2. Therefore, the protective member 5 can be easily inserted into the opening 27 along the inner circumferential surface of the opening 27 of the receiving port 2. In addition, since the cover portion 51 extends axially and radially along the inclined surface 27b, foreign matter G can be easily discharged towards the opening of the receiving port 2.

[0068] 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. This makes it possible to more reliably prevent foreign matter G from adhering to the sealing member 4 by the protective member 5.

[0069] The holding portion 52 according to the first embodiment has a bent portion 52a that bends to cover the flange 28. 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. Furthermore, the protective member 5 according to the first and second embodiments has a receiving port 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 port 2. Therefore, it can be easily positioned relative to the opening end surface of the receiving port 2, and movement of the protective member 5 can be reliably prevented when inserting the insertion port 3 into the receiving port 2.

[0070] (First modified example of the protective member according to the first embodiment) Figure 8 shows a modified example of the protective member 5 according to the first embodiment. As shown in Figure 8, in this modified example, the recess 421c is not formed on the inner circumferential surface of the insertion support portion 42 of the seal member 4 shown in Figure 2, and the engaging portion 51b is not formed on the outer circumferential surface of the cover portion 51. In other words, the outer circumferential surface of the extension portion 513A of the cover portion 51A of the protective member 5A is composed of tapered surfaces located on the same plane. Also, the seal member 4A does not have a recess formed between the seal body portion 41A and the insertion support portion 42A.

[0071] (Second 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 that engages with the protrusion is formed on the outer circumferential surface of the cover portion 51. In this modified example, the portion of the protrusion that engages with the concave engaging portion is formed in a curved shape.

[0072] [Second Embodiment] Figure 9 shows a protective member 5B according to the second embodiment. As shown in Figure 9, the protective member 5B according to this embodiment differs from the first modified example of the first embodiment in that the holding portion 52B 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 modified example of the first embodiment are denoted by the same reference numerals and their descriptions are omitted; only the differences will be described below.

[0073] The holding portion 52B of the protective member 5B has a receiving end surface covering portion 52Bb that extends radially inward so as to cover the opening end surface of the opening 27 of the receiving opening 2. The protective member 5B is held on the opening side of the receiving opening 2 by the holding portion 52B of the protective member 5B contacting the opening end surface of the opening 27 of the receiving opening 2.

[0074] [Third Embodiment] Figure 10 shows a protective member 5C according to the third embodiment. As shown in Figure 10, the protective member 5C according to this embodiment differs from the first modified example of the first embodiment in that it has a retaining portion 52C 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 modified example of the first embodiment are denoted by the same reference numerals and their descriptions are omitted, and only the differences will be described below.

[0075] 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 52C of the protective member 5C fits. The holding portion 52C of the protective member 5C rises vertically from the opening side end of the receiving port 2 in the extension portion 513C and is held on the opening side of the receiving port 2 of the pipe to be joined W1.

[0076] (Modified examples of protective members according to the second and third embodiments) Although not shown in the figures, similar to the first embodiment, recesses or protrusions may be formed on the inner circumferential surfaces of the insertion support portions 42A and 42B of the sealing members 4A and 4B, and engaging portions that engage with the recesses or protrusions may be formed on the outer circumferential surfaces of the protective members 5B and 5C.

[0077] As described above, the cover portions 51, 51A, 51B, and 51C of the protective members 5, 5A, 5B, and 5C cover at least the inner circumferential surface of the insertion support portions 42, 42A, and 42B of the sealing members 4, 4A, and 4B. That is, they cover the sealing members 4, 4A, and 4B from one end on the opening side of the receiving port 2 to the other end on the sealing body portion 41, 41A, and 41B side of the insertion support portions 42, 42A, and 42B. This prevents foreign matter G from adhering to the inner circumferential surface of the insertion support portions 42, 42A, and 42B of the sealing members 4, 4A, and 4B. Therefore, when inserting the insertion port 3 of the pipe W2 into the receiving port 2 of the pipe to be joined, it is possible to prevent cracks from occurring on the surface of the sealing members 4, 4A, and 4B.

[0078] Furthermore, the seal body portions 41, 41A, and 41B, which are compressed by the outer circumferential surface 31 of the insertion port 3 and the inner circumferential surface 21 of the receiving port 2, are not covered by the protective members 5, 5A, 5B, and 5C. Therefore, the seal body portions 41, 41A, and 41B can be compressed radially without being obstructed by the protective members 5, 5A, 5B, and 5C. In addition, the protective members 5, 5A, 5B, and 5C cover the inner circumferential surfaces of the insertion support portions 42, 42A, and 42B of the seal members 4, 4A, and 4B. Therefore, the insertion support portions 42, 42A, and 42B can be protected.

[0079] Therefore, in the sealing members 4, 4A, and 4B that seal the space between the spigot 3 of pipe W2 and the receiving 2 of the pipe to be joined, it is possible to provide a joint structure that allows the spigot 3 to be inserted into the receiving 2 while preventing foreign matter G from adhering to the surface of the sealing members 4, 4A, and 4B.

[0080] (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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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]

[0086] 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]

[0087] 1. Joint structure 2 socket 3. Insertion port 4, 4A sealing member 5, 5A, 5B, 5C Protective material 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 Seal body 42, 42A, 42B Insertion support section 42C Notch 51, 51A Cover section 51b Engagement part 52, 52B, 52C holding part 52a Bend part 52b, 52Bb Socket end covering part 411 Seal bulge 412 Outer circumference of seal 421a Tapered section 421b outer periphery 421c recess 422 Annular projection 513, 513A, 513C extension 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 has a cover portion that covers at least the inner circumferential surface of the insertion support portion, Joint structure.

2. 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.

3. 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 annular shape is such that it follows the inner circumferential surface of the insertion support portion. Joint structure.

4. In the joint structure according to any one of claims 1 to 3, The protective member is It has a retaining portion that engages with and is held by a flange located on the outer peripheral surface of the opening side of the receiving port, Joint structure.

5. In the joint structure described in claim 4, The inner circumferential surface of the opening of the aforementioned socket is The receiving opening has an inclined surface with a larger inner diameter towards the opening side, The aforementioned cover portion is Extending axially and radially along the aforementioned inclined surface, Joint structure.

6. 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, Having, Protective material.

7. A protective member according to claim 6, The aforementioned retaining part is A bent portion that bends to cover the flange located on the outer peripheral surface of the opening side of the socket, The bent portion includes a receiving end surface covering portion that extends radially inward from the opening side of the receiving end so as to cover the opening end surface of the receiving end, and is connected to the opening side of the receiving end in the cover portion. Protective material.

8. In the protective member according to claim 7, The inner circumferential surface of the cover portion is The inner diameter tapers from the receiving end surface covering portion towards the tip. Protective material.

Images