Rotary fusion fittings for piping

Abstract

Provided is a rotary fusion joint for piping that connects dissimilar pipes, such as resin piping components and metal piping components, which ensures workability at the construction site, distributes bending loads acting on the connection, and maintains liquid-tightness and durability over the long term. [Solution] A rotary fusion joint for piping (100) comprises a resin heat fusion joint (10), a threaded metal connector (20), and a metal incore (30). A first angled protrusion (10c) is formed on the outer peripheral wall of the other end of the heat fusion joint (10), and engages with a second angled protrusion (20b) formed on the inner peripheral wall of the threaded metal connector (20), thereby connecting the two so that they cannot be removed axially and can rotate freely relative to each other. The metal incore (30) is housed across the internal passages (10a, 20a) of the heat fusion joint (10) and the threaded metal connector (20), and is sealed and maintained at both ends via first and second water stop rings (30b, 30c).

Description

[Technical Field]

[0001] The present invention relates to the field of piping technology, and more particularly to a rotary fusion joint for piping used to connect dissimilar pipes, such as a resin piping member and a metal piping member. [Background technology]

[0002] Conventionally, electrofusion resin joints have been widely used to connect resin piping components to each other. Such electrofusion resin joints have an electric heating coil installed in the socket of the joint, and when an electric current is applied to the coil, the resin on the inner circumferential surface of the socket melts and is thermally fused to the outer circumferential surface of the piping component inserted therein.

[0003] Meanwhile, in building facilities and water supply facilities, the end of a plastic piping component is often connected to a metal piping component of a water supply fixture. Conventionally, to connect such dissimilar pipes, such as a plastic piping component and a metal piping component, a piping joint that integrates an electrofusion joint and a threaded metal connector has been used. However, in this structure, because the electrofusion joint and the threaded metal connector are fixed together, the piping joint itself cannot be rotated during installation, and the metal piping component on the water supply fixture side must be rotated and screwed together. As a result, there was a problem of poor installation workability, particularly in confined spaces, which reduced work efficiency.

[0004] Furthermore, as a piping joint used to connect different types of pipes, prior art document 1 (JP 2015-152064 A) discloses a conversion joint in which a plastic pipe connection part is provided at one end of a metal joint body, and a metal ring is fitted onto the outside of the plastic pipe fitted onto the plastic pipe connection part and pressed to fix it in place.

[0005] Furthermore, prior art document 2 (JP 2020-133805 A) describes a piping joint used to connect dissimilar pipes. The outer peripheral surface of the insertion end of a cylindrical incore is tapered, with the diameter decreasing toward the tip. Furthermore, the inner peripheral surface is made smaller in diameter than the remaining portions. This reduces insertion resistance and prevents scraping of the inner peripheral surface of the piping component. Furthermore, in this piping joint equipped with the incore, a first flow path member (outer cylindrical portion) and a second flow path member (inner cylindrical portion) are snap-engaged together. The incore is inserted into the inner cylindrical portion, preventing the snap engagement by the claws from releasing over a long period of time. Furthermore, the inner peripheral surface of the inner cylindrical portion is provided with multiple recesses and temporary holding portions sandwiched between them, allowing for easy assembly even when the incore is temporarily inserted. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-152064 [Patent Document 2] Japanese Patent Publication No. 2020-133805 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the conversion joint in Prior Art Document 1 (see Patent Document 1) can be rotated and connected to a metal pipe member using a union nut, which makes it easy to work with at the construction site and allows for the handling of twisting. However, the joining of the plastic pipe and the metal joint relies on locking by ring pressure and protrusions, and there is room for improvement in terms of the number of parts and long-term sealing reliability.

[0008] Furthermore, the configuration disclosed in Prior Document 2 (see Patent Document 2) uses an in-core that firmly holds the snap engagement and also allows for a rotational connection using a nut, so workability and resistance to twisting were achieved to a certain extent. However, although this technology is effective in reducing resistance during insertion and preventing scraping of the inner circumferential surface, it cannot be said to be sufficient in dealing with the bending load acting on the connection point between the first flow path member (outer tubular portion) and the second flow path member (inner tubular portion).

[0009] Therefore, the purpose of this invention is to provide a rotary fusion joint for piping that connects dissimilar pipes, such as plastic piping components and metal piping components, by ensuring workability at the construction site and ability to handle twisting, while also distributing the bending load acting on the rotary fusion joint and mitigating stress concentration, and by providing a connection that has stable sealing properties and is highly reliable over the long term. [Means for solving the problem]

[0010] In order to achieve the above object, the rotary fusion joint for piping according to the present invention is a rotary fusion joint for piping that is connected to a plastic piping component and a metal piping component as mating elements, and the rotary fusion joint for piping comprises a plastic heat fusion joint, a threaded metal connector, and a metal in-core, the plastic heat fusion joint having an internal passage and a receptacle at one end into which the insertion end of the plastic piping component as the mating element is inserted, the inner peripheral surface of the receptacle being heat fused to the outer peripheral surface of the insertion end, and a first angled protrusion formed on the outer peripheral wall of the other end, the threaded metal connector having an internal passage and a second angled protrusion formed on the inner peripheral wall of the one end, a threaded portion at the other end, and a nut portion formed on the outer peripheral wall, and the threaded metal connector is connected to the other end of the plastic heat fusion joint. and a first angled protrusion and a second angled protrusion are fitted onto the outside of the metal fitting, and the first angled protrusion and the second angled protrusion are engaged, thereby connecting the threaded metal fitting and the plastic heat fusion joint so that they cannot be detached and can rotate freely relative to each other; the metal incore has an internal passage and is housed within the internal passage of the plastic heat fusion joint and the internal passage of the threaded metal fitting, and is arranged across both of these internal passages; the outer peripheral wall of one end of the metal incore is held in a liquid-tight seal against the inner peripheral wall of the plastic heat fusion joint via a first water-stop ring, and the outer peripheral wall of the other end is held in a liquid-tight seal against the inner peripheral wall of the threaded metal fitting via a second water-stop ring; and the other end of the plastic heat fusion joint is clamped by the threaded metal fitting and the metal incore from both the outer peripheral wall side and the inner peripheral wall side.

[0011] With this rotary fusion joint for piping, the resin heat fusion joint and the threaded metal connector are axially and non-detachably connected by the interlocking of their angled protrusions, and the threaded metal connector is circumferentially rotatably held relative to the resin heat fusion joint. This allows the threaded metal connector to be rotated and threadedly connected to the metal piping component at the construction site, improving workability. Furthermore, the other end of the resin heat fusion joint is clamped by the threaded metal connector and the incore from both the outer and inner peripheral wall sides, preventing deformation of the other end. Furthermore, because the incore is positioned across the internal passage of the resin heat fusion joint and the threaded metal connector, even if a bending load acts on the connection between the resin heat fusion joint and the threaded metal connector, the load is not concentrated at the connection point but is distributed to the threaded metal connector via the incore. As a result, the durability of the connection between the resin heat fusion joint and the threaded metal connector is improved, improving the long-term reliability of the entire piping system.

[0012] In this device, a stepped portion is provided on the inner wall of the threaded metal connector, and a small diameter portion and a large diameter portion are formed at the stepped portion; the outer wall of the other end of the metal core is liquid-tightly sealed to the threaded metal connector via a second watertight ring on the inner wall of the small diameter portion; the other end of the resin heat-fused joint is located between the outer wall of the metal core and the inner wall of the large diameter portion, and the end face of the other end of the resin heat-fused joint is located opposite the stepped portion.

[0013] This allows the other end of the resin heat-sealed joint to be securely clamped between the metal in-core and the inner peripheral wall of the large-diameter portion. Furthermore, since the end face of the other end of the resin heat-sealed joint is positioned opposite the step portion, the axial position of the resin heat-sealed joint is restricted, preventing misalignment and deformation during assembly and use.

[0014] In this invention, a configuration can be adopted in which a rib is formed on the outer periphery of the metal core, and the rib is interposed between the other end face of the resin heat fusion joint and the step portion of the threaded metal connector.

[0015] According to this, the rib is interposed between the other end face of the resin heat-fused joint and the step portion of the threaded metal connector, thereby suppressing axial movement of the metal core and preventing deviation or tilt in the radial or inclined direction.

[0016] In the present invention, a configuration can be adopted in which the first water stop ring and the second water stop ring are mounted in a first outer peripheral groove and a second outer peripheral groove formed in the metal inner core.

[0017] According to this, by forming the groove of the water stop ring on the outer periphery of the metal in-core, processing and manufacturing become easier, which also contributes to reducing manufacturing costs. [Effects of the Invention]

[0018] The metal fitting is then tightened to the metal piping, and the metal fitting is then tightened to the metal piping. The ... [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a side view showing a first embodiment of a rotary fusion joint for piping according to the present invention; [Figure 2] Arrow II view of Figure 1 [Figure 3] III-III cross section of Figure 2 [Figure 4] FIG. 1 is a cross-sectional view showing a second embodiment of a rotary fusion joint for piping according to the present invention. [Figure 5] FIG. 3 is a cross-sectional view showing a third embodiment of the rotary fusion joint for piping according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] FIG. 1 is a side view showing a first embodiment of a rotary fusion joint for piping 100 according to the present invention, FIG. 2 is a view taken along the arrow II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

[0021] As can be seen in Figures 1, 2 and 3, the rotary fusion joint for piping 100 according to the first embodiment comprises a resin heat fusion joint 10, a threaded metal connector 20, and a metal core 30 (Figure 3).

[0022] The resin heat fusion joint 10 will now be described. As shown in Figure 3, the resin heat fusion joint 10 has an internal passage 10a, one end of which is formed with a socket 10b into which an insertion port (not shown) of a resin piping member (not shown), which is the mating element, is inserted. The inner circumferential surface of the socket 10b is fitted with a molten resin portion 12 that melts and becomes integrated with the resin piping member when joined, and an electric heating coil 11 that heats this molten resin portion 12. When electricity is applied to the electric heating coil 11 during construction, the molten resin portion 12 is heated and is heat-fused to the outer circumferential surface of the resin piping member inserted into the socket 10b.

[0023] The electric heating coil 11 is provided with a terminal 13 for supplying electric power from an external power source. The terminal 13 is disposed on the outer periphery of the resin heat fusion joint 10, and during construction, a power supply device is connected to the terminal 13, causing an electric current to flow through the electric heating coil 11 and heating the molten resin portion 12.

[0024] On the other hand, a first angled protrusion 10c is formed on the outer peripheral wall of the other end of the resin heat-sealed joint 10 as shown in Fig. 3. In the first embodiment, the first angled protrusion 10c is formed as an annular protrusion extending around the entire circumference in the circumferential direction, and is provided in three stages along the axial direction.

[0025] Next, the threaded metal connector 20 will be described. The threaded metal connector 20 according to the first embodiment has an internal passage 20a, and a second angled protrusion 20b is formed on the inner peripheral wall of one end of the connector. The second angled protrusion 20b is formed as an annular protrusion extending around the entire circumference, and is provided in three stages along the axial direction. A threaded portion 20x1 is provided on the outer periphery of the other end for threaded connection to a metal piping member (not shown), which is the mating element, and a nut portion 20x2 is formed on the outer peripheral wall, protruding outward. This allows a tool to be applied to the nut portion 20x2 for tightening during installation.

[0026] In the rotary fusion joint for piping 100 according to the first embodiment, the threaded metal connector 20 is fitted onto the other end of the plastic heat fusion joint 10. That is, a first angled projection 10c formed on the outer peripheral wall of the plastic heat fusion joint 10 and a second angled projection 20b formed on the inner peripheral wall of the threaded metal connector 20 are engaged with each other, thereby connecting the two. The first angled projection 10c and the second angled projection 20b have introduction surfaces that are gently inclined in the mating direction, allowing the threaded metal connector 20 to be easily pushed into the plastic heat fusion joint 10. On the other hand, because they have a return shape that is steeply inclined in the removal direction, the engagement portions reliably interlock when the two are mated, forming a retaining structure that prevents disengagement in the axial direction. As a result, the resin heat-sealed joint 10 and the threaded metal connector 20 are held in an axially inaccessible state, while being connected so as to be rotatable relative to each other in the circumferential direction, and the threaded metal connector 20 can be rotated at the construction site to threadably connect to the metal piping component.

[0027] Next, the metal inner core 30 will be described. The metal inner core 30 is a cylindrical member having an internal passage 30a. As shown in Fig. 3, the metal inner core 30 is housed across the internal passage 10a of the resin heat fusion joint 10 and the internal passage 20a of the threaded metal connector 20. As a result, it is disposed between the resin heat fusion joint 10 and the threaded metal connector 20.

[0028] Furthermore, a first outer circumferential groove 30e for accommodating the first water stop ring 30b and a second outer circumferential groove 30f for accommodating the second water stop ring 30c are formed on the outer circumferential wall of the metal in-core 30. By fitting the water stop rings 30b, 30c into these outer circumferential grooves 30e, 30f, respectively, a liquid-tight seal is ensured.

[0029] The metal incore 30 configured in this manner plays a role in reliably ensuring the continuity and liquid-tightness of the fluid passage at the connection point between the resin heat fusion joint 10 and the threaded metal connector 20. In addition, the other end of the resin heat fusion joint 10 is sandwiched from both the outer peripheral wall side and the inner peripheral wall side by the threaded metal connector 20 and the metal incore 30, preventing deformation of that portion. Furthermore, because the metal incore 30 is arranged across the internal passage, even if a bending load is applied, the load is not concentrated only at the connection point between the resin heat fusion joint 10 and the threaded metal connector 20, but is distributed to the threaded metal connector 20 via the metal incore 30, improving the durability of the rotary fusion joint for piping 100 and the reliability of the piping system as a whole.

[0030] As shown in Figure 3, a step 20c1 is provided in the internal passage 20a of the threaded metal connector 20, and a small diameter section 20a1 is formed on the other end side of this step 20c1, and a large diameter section 20a2 is formed on one end side. The outer peripheral wall of the other end of the metal incore 30 is liquid-tightly sealed to the threaded metal connector 20 via a second watertight ring 30c on the inner peripheral wall of the small diameter section 20a1. Meanwhile, the other end of the resin heat-sealed joint 10 is located between the outer peripheral wall of the metal incore 30 and the inner peripheral wall of the large diameter section 20a2, and the other end face 10d of the resin heat-sealed joint 10 is located opposite the step 20c1.

[0031] An annular rib 30d extending circumferentially around the entire outer periphery of the metal incore 30 is formed, and this rib 30d is provided at a position interposed between the other end face 10d of the resin heat fusion joint 10 and the step portion 20c1 of the threaded metal connector 20. This restricts axial movement of the metal incore 30. Furthermore, the rib 30d not only suppresses axial movement of the metal incore 30, but also prevents deviation or tilt in the radial or inclined directions. As a result, the coaxiality of the metal incore 30, the resin heat fusion joint 10, and the threaded metal connector 20 is maintained, the compressive force applied to the waterstop rings 30b and 30c is uniform, and the liquid-tightness is further stabilized.

[0032] Next, a second embodiment of the present invention will be described with reference to Figure 4. Figure 4 is a cross-sectional view showing a second embodiment of a rotary fusion fitting for piping 100 according to the present invention. While the first embodiment had a configuration in which threaded portion 20x1 was provided on the outer periphery of the other end of threaded metal connector 20, rotary fusion fitting for piping 100 of this embodiment has a configuration in which threaded portion 20x1 is provided on the inner periphery of internal passage 20a of threaded metal connector 20. Also in this embodiment, a nut portion 20x2 is formed on the outer periphery wall of threaded metal connector 20, allowing for easy tightening by applying a tool during installation.

[0033] Next, a third embodiment of the present invention will be described with reference to Fig. 5. Fig. 5 is a cross-sectional view showing a third embodiment of a rotary fusion joint for piping 100 according to the present invention. The rotary fusion joint for piping 100 of this embodiment is characterized in that the metal in-core 30 in the first embodiment does not have a rib 30d.

[0034] 5, two steps are provided in the internal passage 20a of the threaded metal connector 20. Specifically, a first step 20c1 is formed at the boundary between the small diameter portion 20a1 and the large diameter portion 20a2, and the outer peripheral wall of the metal incore 30 is liquid-tightly sealed in the small diameter portion 20a1 via a second watertight ring 30c. Furthermore, a second step 20c2 is formed in the internal passage 20a on the other end side, and the other end face 30g of the metal incore 30 is positioned opposite this second step 20c2.

[0035] Meanwhile, a step 10e is also provided in the internal passage 10a of the resin heat fusion joint 10, and one end face 30h of the metal incore 30 is positioned opposite this step 10e. Therefore, the metal incore 30 is positioned in the axial direction by having both end faces 30h, 30g opposite the step 10e on the resin heat fusion joint 10 side and the second step 20c2 on the threaded metal connector 20 side, respectively, and axial movement of the metal incore 30 is suppressed. [Explanation of symbols]

[0036] 100 Rotary fusion fitting for piping 10. Resin heat-sealed joints 10a Internal passage 10b Underbite 10c 1st chevron protrusion 10d Other end face (other end face of resin heat fusion joint) 10e Stepped part (stepped part of resin heat fusion joint) 11 Electric heating coil 12 Molten resin section 13 terminals 20 Threaded metal connectors 20a Internal Passage 20a1 Small diameter section 20a2 Large diameter part 20b 2nd chevron protrusion 20c1 Step 20c2 Step portion (second step portion) 20x1 threaded section 20x2 nut part 30 Metallic In-core 30a Internal passage 30b First water stop ring 30c Second water stop ring 30d rib 30e First peripheral groove 30f 2nd outer circumferential groove 30g Other end face (other end face of metal core) 30h One end face (One end face of the metal in-core)

Claims

1. A rotary fusion joint for piping that is connected to a resin piping member and a metal piping member as counterpart elements, The rotary fusion joint for piping comprises a resin heat fusion joint, a threaded metal connector, and a metal in-core; The resin heat-sealed joint has an internal passage, a socket at one end into which the insertion port of the resin piping member, which is the mating element, is inserted, and the inner peripheral surface of the socket can be heat-sealed to the outer peripheral surface of the insertion port, and a first angle-shaped protrusion is formed on the outer peripheral wall of the other end, the threaded metal connector has an internal passage, a second angled projection formed on an inner peripheral wall of one end, a threaded portion formed on the other end, and a nut portion formed on an outer peripheral wall; The threaded metal connector is fitted onto the other end of the resin heat fusion joint, and the first angled protrusion and the second angled protrusion are engaged, thereby connecting the threaded metal connector and the resin heat fusion joint in an undetachable manner and relatively rotatable, the metal core has an internal passage, is accommodated in the internal passage of the resin heat fusion joint and the internal passage of the threaded metal connector, and is disposed across both of these internal passages; an outer peripheral wall of one end of the metal in-core is liquid-tightly sealed and held against the inner peripheral wall of the resin heat-sealed joint via a first water-stop ring, and an outer peripheral wall of the other end of the metal in-core is liquid-tightly sealed and held against the inner peripheral wall of the threaded metal connector via a second water-stop ring; A rotary fusion joint for piping, characterized in that the other end of the resin heat fusion joint is clamped from both the outer wall side and the inner wall side by the threaded metal connector and the metal incore.

2. 2. The rotary fusion joint for piping according to claim 1, a step portion is provided on the inner peripheral wall of the threaded metal connector, and a small diameter portion and a large diameter portion are formed with the step portion as a boundary; an outer peripheral wall of the other end of the metal in-core is held in a liquid-tight seal to the threaded metal connector via a second watertight ring at an inner peripheral wall of the small diameter portion; a rotary fusion joint for piping, characterized in that the other end of the resin heat fusion joint is located between the outer peripheral wall of the metal in-core and the inner peripheral wall of the large diameter portion, and the end face of the other end of the resin heat fusion joint is located opposite the step portion.

3. 3. The rotary fusion joint for piping according to claim 2, A rib is formed on the outer periphery of the metal in-core, A rotary fusion joint for piping, characterized in that the rib is interposed between the other end face of the resin heat fusion joint and the stepped portion of the threaded metal connector.

4. The rotary fusion joint for piping according to any one of claims 1 to 3, A rotary fusion joint for piping, characterized in that the first water stop ring and the second water stop ring are mounted in first and second outer peripheral grooves formed on the outer periphery of the metal inner core.

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