Pipe fittings

Abstract

To provide a piping joint which is easy in the construction of piping, is low in a cost, hardly causes aged deterioration, and is high in reliability.SOLUTION: A water piping joint 1 comprises: a pipe body 2 which has one end part provided with a metal-made sleeve 3 and the other end part provided with a metal-made socket 4 connectable with a sprinkler head 23, and which is provided with a communication pipe part 5 for making the sleeve 3 and the socket 4 communicate with each other; and a cylindrical joint body 8 which has one end part externally fit to the sleeve 3 and the other end part connectable with a resin pipe part 21a. The communication pipe part 5 is formed of a resin material. One end part of the joint body 8 is formed of a metal material, and the other end part of the joint body 8 is formed of a resin material.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a pipe joint used, for example, when connecting a pipe for transporting water to other pipes, sprinkler heads, or the like.

Background Art

[0002] Conventionally, pipes for transporting water, such as water supply pipes and sprinkler payout pipes, are generally connected to other pipes, water storage tanks, etc. using pipe joints. For example, the pipe joint disclosed in Patent Document 1 connects a fire protection pipe extending in the ceiling space of a building and a sprinkler head attached to the ceiling of the building when installing a sprinkler facility in the building, and includes an elongated pipe body. The pipe body has a bendable metal bellows portion, a metal sleeve integrally provided at one end side of the bellows portion, and a metal connection end portion provided at the other end side of the bellows portion and connectable to a sprinkler head. One end side of a substantially cylindrical metal joint body is externally fitted to the sleeve. And when a pipe fitter performs pipe work between the fire protection pipe and the sprinkler head, the male screw portion on the other end side of the joint body is screwed and connected to the female screw portion provided at a predetermined position of the fire protection pipe, while the connection end portion of the pipe body is connected to the sprinkler head.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the pipe fitting described in Patent Document 1, for example, if the male threaded portion of the joint body and the female threaded portion of the fire piping that are connected to each other are made of dissimilar metals, or if the connecting end of the pipe bodies and the sprinkler head are made of dissimilar metals, when water is introduced into the joint body from the fire piping, a galvanic cell is formed between the water and each of the aforementioned connecting parts, causing galvanic corrosion (collision between dissimilar metals) to occur at each of those connecting parts. In the case of the pipe fitting described in Patent Document 1, since the bellows section continuous with the connecting end of the pipe body is also made of metal, galvanic corrosion will occur in the bellows section as well, which may lead to corrosion of the entire pipe fitting, accelerating deterioration over time and potentially resulting in an unreliable device.

[0005] Furthermore, for example, in buildings where there are many piping installation points connecting numerous sprinkler heads to fire piping, the workload for piping installers increases, leading to a demand to reduce the burden on piping installation. Moreover, when there are many piping installation points, a large number of pipe fittings are required, so there is also a demand to lower the unit price of parts to achieve cost benefits.

[0006] This invention has been made in view of the above points, and its objective is to provide a highly reliable pipe fitting that is easy to install, low-cost, and resistant to deterioration over time. [Means for solving the problem]

[0007] To achieve the above objective, the present invention is characterized by incorporating ingenious materials for each region constituting the pipe joint.

[0008] Specifically, the present invention relates to a water pipe fitting comprising a pipe body having a metal sleeve at one end and a metal connecting end at the other end that can be connected to a first jointed member, and a connecting pipe section that connects the sleeve and the connecting end, and a cylindrical joint body having one end that fits externally into the sleeve and the other end that can be connected to a second jointed member, and the following solutions were implemented.

[0009] In other words, the first invention is characterized in that the connecting pipe portion is formed of a resin material, one end of the joint body is formed of a metal material, and the other end of the joint body is formed of a resin material.

[0010] The second invention is characterized in that, in the first invention, an electric heating wire for electrofusion bonding is embedded in the other end of the joint body.

[0011] In the third invention, in the first or second invention, one end of the connecting pipe portion is integrally provided inside the sleeve and covers the entire inside area of ​​the sleeve.

[0012] The fourth invention is characterized in that, in the first or second invention, the connecting pipe portion includes a first straight pipe portion that extends linearly and is connected to the sleeve at one end, a second straight pipe portion that extends linearly in a direction different from the direction of extension of the first straight pipe portion and is connected to the connecting end at one end, and a bent portion that is bent to connect the other end of the first straight pipe portion and the other end of the second straight pipe portion.

[0013] In the fifth invention, in the first or second invention, the connecting end is connectable to a sprinkler head as the first jointed member attached to the ceiling of the building, and the other end of the joint body is connected to the second jointed member disposed in the space above the ceiling of the building. component It is characterized by being able to be connected indirectly or directly to fire piping.

[0014] The sixth invention is characterized in that, in the first or second invention, the other end of the joint body has an inner cylinder portion and an outer cylinder portion whose cylinder centerlines coincide with each other, and a double pipe portion is provided between the inner cylinder portion and the outer cylinder portion into which the second jointed member can be fitted from the other end side to the one end side of the joint body.

[0015] The seventh invention is characterized in that, in the first or second invention, the outer circumferential surface of the sleeve is provided with a first circumferential groove that is concave on the inner side and extends in an annular shape, the inner circumferential surface of one end of the joint body is provided with a second circumferential groove that is concave on the outer side and extends in an annular shape, a snap ring is assembled in the first and second circumferential grooves, a first groove portion that is concave on the inner side is provided on the outer circumferential surface of the first circumferential groove on the connecting pipe portion side, a second groove portion that is concave on the inner side is provided on the outer circumferential surface of one end of the joint body, a first inspection jig for inspecting the assembly of the snap ring is configured to be attachable to the first groove portion, and a second inspection jig for inspecting the assembly of the snap ring is configured to be attachable to the second groove portion. [Effects of the Invention]

[0016] In the first invention, when the first jointed member and the connecting end connected to the first jointed member are made of dissimilar metals, for example, even if galvanic corrosion occurs at the connecting end, the connecting pipe section formed continuously with the connecting end is made of resin material, thus suppressing the occurrence of galvanic corrosion in the connecting pipe section. Therefore, it is possible to avoid a situation where galvanic corrosion affects the reliability of the entire pipe joint. Furthermore, since the other end of the joint body connected to the second jointed member is made of resin material, it is possible to prevent galvanic corrosion from occurring between the other end of the joint body and the second jointed member. In this way, corrosion due to galvanic corrosion becomes less likely to occur throughout the entire pipe joint, resulting in a highly reliable pipe joint that is less prone to deterioration over time. Moreover, since the connecting pipe section and the other end of the joint body are made of resin material, the cost can be reduced compared to metal pipe joints such as those described in Patent Document 1, and the entire pipe joint becomes lighter, making pipe installation easier and reducing the workload of pipe installers.

[0017] In the second invention, the other end of the joint body and the second jointed component By bringing the two into contact with each other and passing electricity through the contact area, the joint body and the second joined part componentThe two parts are welded together to form a single unit. Therefore, when a pipe installer uses a pipe fitting like the one described in Patent Document 1 to perform pipe installation, variations in the work, such as the amount the pipe installer screws into the female thread being insufficient against the pipe installer's intention, become less likely to occur. This prevents galvanic corrosion between the pipe fitting and the second joined member, while reliably preventing water leakage at the connection point between the other end of the fitting and the second joined member.

[0018] In the third invention, the inner surface of the sleeve is covered by one end of the connecting pipe made of resin material, so that even if the inside of the pipe fitting is filled with water, the inner surface of the sleeve will not come into direct contact with the water. Therefore, it is possible to suppress the occurrence of electrolytic corrosion in the metal sleeve, for example, by preventing electricity from flowing between the metal sleeve and other metal components via the water.

[0019] In the fourth invention, for example, even if the fire piping to which the other end of the joint body is connected and the sprinkler head to which the connecting end of the pipe body is connected are not arranged in a straight line, a bend exists in the pipe body, so the fire piping and the sprinkler head can be connected without providing a metal bellows section like in Patent Document 1.

[0020] In the fifth invention, even when the pipe fitting is connected to the fire piping and the sprinkler head respectively, and the pipe fitting is filled with water introduced from the fire piping, it is possible to suppress the occurrence of electrolytic corrosion in the pipe and fitting body of the pipe fitting.

[0021] In the sixth invention, when the second jointed member is fitted into the double-pipe portion of the joint body, the double-pipe portion of the joint body and the second jointed member are connected with the second jointed member sandwiched between the inner cylinder portion and the outer cylinder portion. Therefore, the joint body of the pipe joint and the second jointed member component The rigidity of the connection between the joint body and the second jointed body can be improved, for example, between the joint body and the second jointed body component This makes it possible to more reliably prevent water leaks from occurring at the connection points.

[0022] In the seventh invention, after the snap ring is assembled to the first groove portion and the second groove portion, for example, by pulling the first inspection jig attached to the first groove portion to one side and pulling the second inspection jig attached to the second groove portion to the other side, it becomes possible to inspect the assembled state of the snap ring. Thereby, it is possible to confirm whether or not there is a defective assembly of the snap ring.

Brief Description of the Drawings

[0023] [Figure 1] It is a plan view showing a pipe joint for water according to the first embodiment of the present invention. [Figure 2] It is a schematic explanatory view of a sprinkler device in which a pipe joint for water according to the first embodiment of the present invention is used. [Figure 3] It is a cross-sectional view taken along line III-III of FIG. 1. [Figure 4] It is a view corresponding to FIG. 3 according to a modification. [Figure 5] It is a view corresponding to FIG. 3 according to a modification. [Figure 6] It is a view corresponding to FIG. 3 according to the second embodiment of the present invention. [Figure 7] It is a view corresponding to FIG. 6 according to a modification. [Figure 8] It is a view corresponding to FIG. 6 according to a modification. <{

Modes for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature.

[0025] 《First Embodiment》 FIG. 1 shows a pipe joint 1 for water according to the first embodiment of the present invention. As shown in FIG. 2, the pipe joint 1 is used for a partial structure of a sprinkler device 20, and connects a fire protection pipe 21 extending horizontally and vertically in the ceiling space S1 of a building and a metal sprinkler head 23 (first joint member) attached to the ceiling 22 of the building.

[0026] The pipe fitting 1 comprises a pipe body 2 that is roughly L-shaped. As shown in Figure 3, the pipe body 2 is equipped with a metal sleeve 3 (for example, a metal material such as steel), a metal socket 4 (for example, a metal material such as steel), and a connecting pipe section 5 made of resin (for example, a resin material such as polyethylene).

[0027] As shown in Figure 3, sleeve 3 is provided at one end of pipe 2 and has a substantially cylindrical shape.

[0028] As shown in Figure 3, the socket 4 is provided at the other end of the pipe 2 and has a roughly rectangular shape. The inner surface 4a of the socket 4 has a female screw thread, and the female screw thread on the inner surface 4a is screwed into the male screw thread on the sprinkler head 23.

[0029] As shown in Figure 3, the connecting pipe section 5 is substantially L-shaped and comprises a first straight pipe section 5a, a second straight pipe section 5b, and a bent section 5c.

[0030] The first straight pipe section 5a extends linearly along the first cylinder centerline C1, with one end integrally provided inside the sleeve 3 and covering the entire inside area of ​​the sleeve 3. The first straight pipe section 5a and the sleeve 3 are integrally molded by insert molding.

[0031] The second straight pipe section 5b extends linearly along the second cylinder centerline C2, which is substantially perpendicular to the extension direction of the first straight pipe section 5a, and one end thereof is joined to the socket 4 by integral molding using insert molding. The second straight pipe section 5b is set to have a longer pipe length than the first straight pipe section 5a, and as shown in Figure 1, multiple protruding sections 5d are formed on its outer surface at predetermined intervals in the circumferential direction around the second cylinder centerline C2, with the protrusions extending radially outward and linearly along the second cylinder centerline C2.

[0032] The bent section 5c is shaped to connect the other end of the first straight pipe section 5a with the other end of the second straight pipe section 5b.

[0033] As shown in Figure 3, an annular projection 3a is formed on the outer surface of the sleeve 3 near the bent portion 5c in the middle, which protrudes radially outward and extends around the first cylinder centerline C1.

[0034] The annular protrusion 3a is composed of a first protrusion 3b on the side of the bent portion 5c and a second protrusion 3c on the side further from the bent portion 5c, with the first protrusion 3b having a shape that protrudes outward more than the second protrusion 3c. A first circumferential groove 3d is formed on the outer circumferential surface of the first protrusion 3b, which is concave on the inner circumferential side and extends in an annular shape with respect to the first cylinder centerline C1.

[0035] A first insulating ring 6a and a second insulating ring 6b made of resin are fitted onto the outer surface of the sleeve 3, starting from the side of the bent portion 5c, with one end facing the bent portion 5c side.

[0036] The first insulating ring 6a is positioned on the side of the first protruding portion 3b that is farther from the bent portion 5c and spaced apart from the first protruding portion 3b. The cross-section of the first insulating ring 6a in the direction along the first cylinder centerline C1 is substantially L-shaped, and the first insulating ring 6a extends around the first cylinder centerline C1 along the corner of the second protruding portion 3c.

[0037] The second insulating ring 6b is positioned at a location corresponding to the end of the sleeve 3 furthest from the bent portion 5c, and at a distance from the first insulating ring 6a. The cross-section of the second insulating ring 6b in the direction along the first cylinder centerline C1 is approximately L-shaped, and the second insulating ring 6b extends around the first cylinder centerline C1 along the end of the sleeve 3 furthest from the bent portion 5c.

[0038] A first annular sealing portion 7a made of rubber is fitted to the bent portion 5c side of the first insulating ring 6a in the second protruding portion 3c, and a second annular sealing portion 7b made of rubber, which is larger than the first annular sealing portion 7a, is fitted to the space between the first insulating ring 6a and the second insulating ring 6b of the sleeve 3.

[0039] A substantially cylindrical joint body 8 is provided on the outside of the sleeve 3, with the center line of the cylinder coinciding with the first cylinder center line C1. The joint body 8 is externally fitted onto the first protruding portion 3b, the first insulating ring 6a, and the second insulating ring 6b of the sleeve 3.

[0040] The joint body 8 has a metal component 9, with approximately half of one end made of a metal material (e.g., steel), and a resin component 10, with approximately half of the other end made of a resin material (e.g., polyethylene). In other words, the part of the joint body 8 excluding the resin component 10 is the metal component 9, and the resin component 10 is integrally molded with the metal component 9 by insert molding.

[0041] One end of the metal component 9 is provided with a first enlarged diameter portion 9b, which is larger in diameter than the first intermediate portion 9a located at the other end. On the inner circumferential surface of the first enlarged diameter portion 9b, in the area corresponding to the first circumferential groove 3d, a second circumferential groove 9c is formed, which is concave on the outer circumferential side and extends in an annular shape around the first cylinder centerline C1. Snap rings 15 are mounted in the first circumferential groove 3d and the second circumferential groove 9c in a state biased in the diameter-expanding direction.

[0042] On the other hand, the other end of the metal component 9 is provided with a second enlarged diameter portion 9d, which has a wall thickness greater than that of the first intermediate portion 9a and a larger diameter than that of the first intermediate portion 9a.

[0043] One end of the resin component 10 is provided with a third enlarged diameter portion 10b, which is larger in diameter than the second intermediate portion 10a located at the other end, and the third enlarged diameter portion 10b is joined to the second enlarged diameter portion 9d by integral molding using insert molding.

[0044] On the other hand, the other end of the resin component 10 is provided with a tapered portion 10c whose wall thickness is thinner than that of the second intermediate portion 10a and whose diameter is smaller than that of the second intermediate portion 10a.

[0045] A pair of terminal pins 11 that protrude outward are provided on the outer circumferential surfaces of the second intermediate section 10a and the tapered section 10c at predetermined intervals in a direction along the first cylinder centerline C1.

[0046] Inside the second intermediate section 10a, an electrofusion heating wire 12 is embedded, extending spirally around the first cylinder centerline C1. One end of the heating wire 12 is connected to one terminal pin 11, while the other end of the heating wire 12 is connected to the other terminal pin 11.

[0047] Then, with the resin pipe section 21a (second jointed member) of the fire piping 21 fitted into the resin component 10 of the joint body 8, electricity is passed through the heating wire 12 via a pair of terminal pins 11, causing the resin pipe section 21a of the fire piping 21 and the resin component 10 of the joint body 8 to be welded together by electrofusion bonding and become one unit, in other words, the resin pipe section 21a of the fire piping 21 and the resin component 10 of the joint body 8 are directly connected.

[0048] As described above, according to the first embodiment of the present invention, when the sprinkler head 23 and the socket 4 connected to the sprinkler head 23 are made of dissimilar metals, for example, even if galvanic corrosion occurs in the socket 4, the connecting pipe section 5, which is formed continuously with the socket 4, is made of resin material, so it is possible to suppress the occurrence of galvanic corrosion in the connecting pipe section 5. Therefore, it is possible to avoid a situation in which galvanic corrosion affects the reliability of the entire pipe joint 1. In addition, since the resin component 10 of the joint body 8 connected to the resin pipe section 21a is made of resin material, it is possible to prevent galvanic corrosion from occurring between the resin component 10 of the joint body 8 and the resin pipe section 21a. In this way, corrosion due to galvanic corrosion is less likely to occur throughout the entire pipe joint 1, making it possible to create a highly reliable pipe joint 1 that is less prone to deterioration over time. Furthermore, since the connecting pipe section 5 and the resin component 10 of the joint body 8 are made of resin material, it is possible to reduce the cost compared to a metal pipe joint 1 such as the one described in Patent Document 1, and the entire pipe joint 1 is lighter, making pipe installation easier and reducing the workload of pipe installers.

[0049] Furthermore, by bringing the resin component 10 and the resin pipe portion 21a of the joint body 8 into contact with each other and passing electricity through the contact area, the joint body 8 and the resin pipe portion 21a are welded together and become one unit. Therefore, when a pipe installer performs pipe installation using a pipe fitting like the one described in Patent Document 1, variations in the work, such as the amount of screwing the male screw portion into the female screw portion being insufficient against the installer's intention, become less likely to occur. Thus, it is possible to reliably prevent water leakage at the connection point between the resin component 10 and the resin pipe portion 21a of the joint body 8 while preventing electrolytic corrosion between the pipe fitting 1 and the resin pipe portion 21a.

[0050] Furthermore, since the inner surface of the sleeve 3 is covered by one end of the connecting pipe section 5 made of resin material, the inner surface of the sleeve 3 will not come into direct contact with the water even if the inside of the pipe fitting 1 is filled with water. Therefore, it is possible to suppress the occurrence of electrolytic corrosion in the metal sleeve 3, for example, by preventing electricity from flowing between the metal sleeve 3 and other metal components via the water.

[0051] Furthermore, even if, for example, the positions of the fire piping 21 to which the resin component 10 of the joint body 8 is connected and the sprinkler head 23 to which the socket 4 of the pipe body 2 is connected are not arranged in a straight line, the pipe body 2 has a bend 5c, so the fire piping 21 and the sprinkler head 23 can be connected without providing a metal bellows section like in Patent Document 1.

[0052] Furthermore, even when the pipe fitting 1 is connected to the fire piping 21 and the sprinkler head 23, and the pipe fitting 1 is filled with water introduced from the fire piping 21, it is possible to suppress the occurrence of electrolytic corrosion in the pipe body 2 and fitting body 8 of the pipe fitting 1.

[0053] Modified version of the first embodiment In the first embodiment of the present invention, the resin component 10 of the joint body 8 had a single-pipe structure. However, as shown in Figures 4 and 5, a double-pipe section 13 having an inner cylinder section 13a and an outer cylinder section 13b may be provided, and the resin pipe section 21a may be inserted between the inner cylinder section 13a and the outer cylinder section 13b of the double-pipe section 13, moving from the other end to the one end of the joint body 8. In this way, by making the resin pipe section 21a insertable into the double-pipe section 13 of the joint body 8, the double-pipe section 13 of the joint body 8 and the resin pipe section 21a are connected when the resin pipe section 21a is sandwiched between the inner cylinder section 13a and the outer cylinder section 13b. Therefore, the connection rigidity between the joint body 8 of the pipe joint 1 and the resin pipe section 21a can be improved, and for example, water leakage at the connection point between the joint body 8 and the resin pipe section 21a can be more reliably prevented.

[0054] Furthermore, in the first embodiment of the present invention, the length of the second straight pipe section 5b was set to be longer than that of the first straight pipe section 5a, but as shown in Figure 5, the length of the second straight pipe section 5b may be set to be shorter than that of the first straight pipe section 5a. This allows the sprinkler system 20 to be installed in a narrow space S1 above the ceiling, and the pipe joint 1 can connect the fire piping 21 and the sprinkler head 23 in a position where the second centerline C2 of the pipe body 2 is approximately aligned with the vertical direction.

[0055] 《Second Embodiment》 Next, a second embodiment of the present invention will be described with reference to Figure 6. Note that the parts common to the first embodiment will be omitted from the description, and only the parts that differ from the first embodiment will be described.

[0056] The pipe fitting 1 according to the second embodiment differs from the first embodiment in the structure of the sleeve 3, the first annular seal portion 7a, the second annular seal portion 7b, and the metal component 9 of the fitting body 8.

[0057] Furthermore, the pipe joint 1 according to the second embodiment differs from the first embodiment in that it does not have a first insulating ring 6a and a second insulating ring 6b. In other words, the metal component 9 of the joint body 8 according to the second embodiment is externally fitted to the first protruding portion 3b of the sleeve 3 and the portion of the first protruding portion 3b that is farther from the bent portion 5c (the portion that does not protrude radially outward).

[0058] In the second embodiment, the annular protrusion 3a of the sleeve 3 is provided only with the first protrusion 3b. In other words, the annular protrusion 3a of the sleeve 3 in the second embodiment is not provided with the second protrusion 3c.

[0059] On the bent portion 5c side (connecting pipe portion 5 side) of the first circumferential groove 3d in the first protruding portion 3b, a third circumferential groove 3e is provided, which is concave on the inner circumference side and extends in an annular shape with the first cylinder centerline C1 as the center. The third circumferential groove 3e is configured to allow attachment of the first inspection jig J1 for assembly inspection of the snap ring 15.

[0060] On the outer circumferential surface of the sleeve 3, the portion of the first protruding portion 3b furthest from the bent portion 5c is provided with a fourth circumferential groove 3f and a fifth circumferential groove 3g that are concave on the inner circumferential side and extend in an annular shape around the first cylinder centerline C1. The first annular seal portion 7a is fitted onto the fourth circumferential groove 3f, while the second annular seal portion 7b is fitted onto the fifth circumferential groove 3g. In the second embodiment, the first annular seal portion 7a and the second annular seal portion 7b are approximately the same size.

[0061] In the first embodiment, the metal component 9 of the joint body 8 was configured such that the second enlarged diameter portion 9d expanded in diameter towards the other end of the metal component 9. However, in the second embodiment, the metal component 9 of the joint body 8 expands in diameter in a stepped manner from the first intermediate portion 9a. As a result, the first intermediate portion 9a becomes concave on the inner circumference side and forms a sixth circumferential groove 9e that extends in an annular shape around the first cylinder centerline C1. The sixth circumferential groove 9e is configured to allow attachment of a second inspection jig J2 for assembly inspection of the snap ring 15.

[0062] In the second embodiment, after the snap ring 15 is installed in the third circumferential groove 3e of the sleeve 3 and the sixth circumferential groove 9e of the metal component 9 in the joint body 8, that is, after it has been assembled, an inspection process is performed to inspect the assembly state of the snap ring 15. In this inspection process, first, a first inspection jig J1 is attached to the third circumferential groove 3e of the sleeve 3, and a second inspection jig J2 is attached to the sixth circumferential groove 9e of the metal component 9. Next, the first inspection jig J1 is pulled to one side in the extension direction of the first cylinder centerline C1 (towards the bent portion 5c), and the second inspection jig J2 is pulled to the other side in the extension direction of the first cylinder centerline C1 (opposite side from the bent portion 5c), thereby inspecting the assembly state of the snap ring 15 (whether or not it is improperly assembled).

[0063] According to the second embodiment, by not providing the resin first insulating ring 6a and second insulating ring 6b, the contact area between the metal sleeve 3, which has superior heat resistance, and the metal component 9 of the joint body 8 can be increased. As a result, even if heat from a fire or the like acts on the fitting area between the sleeve 3 and the metal component 9 of the joint body 8, it becomes possible to more reliably prevent water leakage from the fitting area.

[0064] Furthermore, according to the second embodiment, after the snap rings 15 are assembled in the third circumferential groove 3e and the sixth circumferential groove 9e, for example, the assembly state of the snap rings 15 can be inspected by pulling the first inspection jig J1 attached to the third circumferential groove 3e to one side (one side in the direction of extension of the first cylinder centerline C1) and pulling the second inspection jig J2 attached to the sixth circumferential groove 9e to the other side (the other side in the direction of extension of the first cylinder centerline C1). This makes it possible to confirm whether or not there are any assembly defects in the snap rings 15.

[0065] Modified version of the second embodiment In the second embodiment of the present invention, the third circumferential groove 3e and the sixth circumferential groove 9e were provided to extend in an annular shape, but they may be provided only in a part of the outer surface, as long as the first inspection jig J1 and the second inspection jig J2 can be attached.

[0066] Furthermore, in the second embodiment of the present invention, an example was described in which the first inspection jig J1 is pulled to one side and the second inspection jig J2 is pulled to the other side during the inspection process. However, it is also possible to fix one of the inspection jigs so that it does not move while pulling only the other inspection jig.

[0067] Furthermore, in the second embodiment of the present invention, the resin component 10 of the joint body 8 was a single-tube structure, but as shown in Figures 7 and 8, a double-tube section 13 having an inner cylinder section 13a and an outer cylinder section 13b may be provided, and the resin tube section 21a may be fitted between the inner cylinder section 13a and the outer cylinder section 13b in the double-tube section 13 from the other end to the one end of the joint body 8. Also, in the second embodiment of the present invention, the length of the second straight tube section 5b was set to be longer than that of the first straight tube section 5a, but as shown in Figure 8, the length of the second straight tube section 5b may be set to be shorter than that of the first straight tube section 5a.

[0068] Modified versions of the first and second embodiments Furthermore, in the first and second embodiments of the present invention, the pipe joint 1 was substantially L-shaped, but it may also be straight.

[0069] Furthermore, in the first and second embodiments of the present invention, the joint body 8 was electrofusion-bonded to the resin pipe portion 21a of the fire piping 21, but it may also be heat-fusion-bonded.

[0070] Furthermore, in the first and second embodiments of the present invention, the joint body 8 was directly connected to the fire piping 21, but it may also be indirectly connected to the fire piping 21 via another pipe joint or the like. [Industrial applicability]

[0071] The present invention is suitable, for example, for pipe fittings used when connecting a water transport pipe to other pipes or sprinkler heads. [Explanation of Symbols]

[0072] 1. Pipe fittings 2. Body 3 sleeves 3d 1st circumferential groove 3e 3rd circumferential groove (1st groove) 4 Sockets (connecting ends) 5. Liaison Pipe Section 5a 1st straight pipe section 5b 2nd straight pipe section 5c Bend part 8 Joint Body 9. Metal component (one end of the joint body) 9c 2nd circumferential groove 9e 6th circumferential groove (2nd groove) 10. Resin component (other end of joint body) 12. Heating wire (heating wire for electrofusion bonding) 13 Double pipe section 13a Inner cylinder part 13b Outer cylinder 15 snap rings 21 Fire piping 21a Resin pipe section (second jointed member) 22 Ceiling 23. Sprinkler head (first jointed member) J1 First Inspection Jig J2 Second Inspection Jig

Claims

1. A pipe body having one end covered by a metal sleeve, the other end having a metal connecting end that can be connected to a first jointed member, and a connecting pipe section connecting the sleeve and the connecting end, A water pipe fitting comprising a cylindrical joint body having one end that fits externally into the sleeve and the other end that can be connected to a second jointed member, The aforementioned connecting pipe section is formed of a resin material, A pipe joint characterized in that one end of the joint body is formed of a metal material, while the other end of the joint body is formed of a resin material.

2. In the pipe fitting according to claim 1, A pipe joint characterized in that an electric heating wire for electrofusion bonding is embedded in the other end of the joint body.

3. In the pipe fitting according to claim 1 or 2, A pipe joint characterized in that one end of the connecting pipe portion is integrally provided inside the sleeve and covers the entire inside area of ​​the sleeve.

4. In the pipe fitting according to claim 1 or 2, The pipe joint is characterized in that the connecting pipe section includes a first straight pipe section that extends in a straight line and is connected to the sleeve at one end, a second straight pipe section that extends in a straight line in a direction different from the direction of extension of the first straight pipe section and is connected to the connecting end at one end, and a bent section that is bent to connect the other end of the first straight pipe section and the other end of the second straight pipe section.

5. In the pipe fitting according to claim 1 or 2, The aforementioned connecting end is connectable to the sprinkler head, which is the first jointed member attached to the ceiling of the building. The other end of the joint body is characterized in that it can be connected indirectly or directly to the fire piping, which is the second jointed member, installed in the ceiling space of the building.

6. In the pipe fitting according to claim 1 or 2, A pipe joint characterized in that the other end of the joint body has an inner cylinder portion and an outer cylinder portion whose cylindrical centerlines coincide, and a double pipe portion is provided between the inner cylinder portion and the outer cylinder portion, into which the second jointed member can be fitted from the other end to the one end of the joint body.

7. In the pipe fitting according to claim 1 or 2, The outer circumferential surface of the sleeve is provided with a first circumferential groove that is concave on the inner side and extends in an annular shape. A second circumferential groove is provided on the inner circumferential surface of one end of the aforementioned joint body, which is concave on the outer circumferential side and extends in an annular shape. Snap rings are fitted into the first and second circumferential grooves. On the outer circumferential surface of the sleeve, a first groove portion is provided on the side of the connecting pipe portion of the first circumferential groove, which is recessed on the inner circumferential side. A second groove is provided on the outer circumferential surface of one end of the aforementioned joint body, with a concave shape on the inner circumferential side. The first groove is configured to allow the attachment of a first inspection jig for inspecting the assembly of the snap ring. A pipe fitting characterized in that a second inspection jig for inspecting the assembly of the snap ring can be attached to the second groove.

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