JP7789031B2 - Pipe fitting, piping assembly kit and construction method using same - Google Patents

Description

The present invention relates to pipe fittings, piping assembly kits, and installation methods using the same.

When wiring power generation equipment that uses renewable energy sources such as solar power, or outdoor wiring in buildings, road facilities, railway facilities, etc., cables are protected by being inserted inside metal piping.

However, metal piping is heavy and requires a lot of work to install, so it is being considered to construct the piping out of lightweight resin, thereby improving workability during installation. In this case, constructing the piping out of lightweight resin also has the advantage of preventing corrosion of the piping.

As an example of a pipe fitting for such resin piping, Non-Patent Document 1 describes a pipe fitting in which the portion that accommodates the end of the piping is elongated to take into account the thermal expansion and contraction of the piping.

"2022 Electrical Materials General Catalog", [online], Mirai Kogyo Co., Ltd., [searched March 18, 2023], Internet <URL: https://sun-dbook.meclib.jp/denzai_mirai_2022/book/#target/page_no=970>

The pipes that house cables tend to expand and contract thermally due to fluctuations in outside temperature and exposure to sunlight. In particular, outdoor wiring, where outside temperature fluctuations are large and cables are prone to direct sunlight, tends to experience greater amounts of thermal expansion and contraction.

In particular, plastic piping has a higher thermal expansion rate than metal piping, and also a higher thermal expansion rate than the concrete and metal used to install the piping. As a result, in the summer, plastic pipes expand thermally along their length (the direction the cable is inserted), causing problems such as damage to the pipe fittings and fixtures that support and secure the pipe. Thermal expansion can also cause the pipe to buckle at the pipe fittings and fixtures, distorting the pipe itself and the connections between the pipe and the pipe fittings or fixtures, thereby damaging the aesthetic appearance. Furthermore, because plastic piping has a higher thermal expansion rate than the conductor part of the cable, there is also the problem that the cable can be pulled by the pipe when the plastic pipe expands thermally along its length.

In this regard, the pipe fitting described in Non-Patent Document 1 has a long section that accommodates the end of the pipe, taking into account the thermal expansion and contraction of the pipe. However, when the plastic pipe thermally expands along its length, the connection between the plastic pipe and the pipe fitting distorts, preventing the pipe fitting from fully absorbing the thermal expansion and contraction of the pipe. Furthermore, because the pipe fitting described in Non-Patent Document 1 has a simple structure in which the end of the pipe is simply inserted into the opening of the cylindrical pipe fitting, there is a problem in that the end of the pipe easily falls off the pipe fitting, particularly when the plastic pipe shrinks due to thermal contraction.

The present invention aims to provide a pipe fitting and piping assembly kit, as well as an installation method using the same, that are less likely to cause distortion due to thermal expansion and contraction in the pipe itself or the connection part with the pipe, even when using resin piping, and that are less likely to cause the end of the pipe to fall off the pipe fitting.

The inventors have discovered that by providing a sliding member at the end of the piping and using a pipe fitting configured so that this sliding member slides in and out of the open end position of the outer tubular member in response to the thermal expansion and contraction of the piping, the sliding member slides relative to the outer tubular member in response to the thermal expansion and contraction of the piping, allowing the pipe fitting to absorb the thermal expansion and contraction of the piping and reducing the likelihood of distortion due to thermal expansion and contraction occurring in the piping itself or the connection portion to the piping. Furthermore, the inventors have discovered that by providing a retaining means in the pipe fitting to prevent the sliding member from falling off the outer tubular member, the positional relationship between the outer tubular member and the sliding member can be defined within a range in which the sliding member can slide due to displacement of the end portion caused by thermal expansion and contraction of the piping.

(1) A pipe fitting for connecting the ends of multiple pipes through which cables are inserted, comprising: a cylindrical outer tube member extending in the direction in which the cables are inserted; a sliding member attached to the end of the pipe, located within the outer tube member, and configured to slide in and out of the open end position of the outer tube member in response to thermal expansion and contraction of the pipe; and a retaining means for preventing the sliding member from falling off the outer tube member.

(2) The pipe fitting described in (1) above, wherein the outer tubular member has a fixing means for fixing it to an object to be installed.

(3) A pipe fitting as described in (1) or (2) above, wherein the sliding member is a ring-shaped member having an outer surface on which at least two first engagement portions, each consisting of a convex or concave portion, are formed; the outer cylindrical member has an inner surface on which at least two second engagement portions, each consisting of a concave or convex portion, are formed to engage with the first engagement portions and extend along the insertion direction; and the sliding member restricts rotation by sliding the first engagement portions and the second engagement portions in an engaged state.

(4) A pipe fitting according to any one of (1) to (3) above, wherein the outer tubular member has a plurality of through holes at positions offset in the cable insertion direction, for discharging water that has entered the internal space of the outer tubular member.

(5) A piping assembly kit having the pipe fitting described in any one of (1) to (4) above, comprising: a plurality of pipes connected by the pipe fittings and having outer surfaces formed by alternatingly connecting ring-shaped recesses and ring-shaped protrusions; and a piping fixture made of an elastic material, having a bottom portion with mounting means, and a pair of gripping portions extending upright from both ends of the bottom portion and having inner surfaces shaped to correspond to the recesses and protrusions that make up the outer surfaces of the pipes.

(6) The piping assembly kit described in (5) above, wherein the piping is a cable protection tube made of polyethylene.

(7) A piping assembly kit according to (5) or (6) above, in which the piping has, in order from the inside out, at least an inner layer, an intermediate layer, and an outer layer, one or both of the inner layer and the intermediate layer containing a flame retardant, and the outer layer containing a weather resistant agent.

(8) An installation method using the piping assembly kit described in any one of (5) to (7) above, comprising the steps of: fixing the outer tubular member of the pipe fitting and the piping fixture to an object to be installed; connecting the sliding member to the end of the piping; inserting the sliding member, to which the piping is connected, into the outer tubular member fixed to the object to be installed; and inserting the piping connected to the outer tubular member by pushing the piping connected to the outer tubular member into a pair of gripping portions of the piping fixture, and fitting the inner surfaces of the gripping portions into the concave and convex portions on the outer surface of the piping.

The present invention provides a pipe fitting and piping assembly kit, as well as an installation method using the same, that are less likely to cause distortion due to thermal expansion and contraction in the pipe itself or the connection part with the pipe, even when using resin piping, and that are less likely to cause the end of the pipe to fall off the pipe fitting.

1A and 1B are diagrams showing the structure of a pipe joint according to an embodiment of the present invention, in which FIG. 1A is a longitudinal cross-sectional view taken along the cable insertion direction, and FIG. 1B is a transverse cross-sectional view taken along a plane perpendicular to the cable insertion direction in FIG. 1A. FIG. 2 is an exploded perspective view showing the arrangement of the components when assembling the pipe joint according to the embodiment of the present invention. FIG. 3 is a cross-sectional view taken along a plane perpendicular to the cable insertion direction, schematically illustrating the structure of a pipe joint according to another embodiment of the present invention, in which the first engagement portion is constituted by a recess and the second engagement portion is constituted by a protrusion. FIG. 4 is a perspective view schematically showing the structure of a pipe joint according to another embodiment of the present invention, in which a retaining means formed by a bent portion of the second engaging portion is provided near the open end of the outer tubular member. 5A and 5B are diagrams showing an example of piping used in the piping assembly kit of the present invention, in which FIG. 5A is a perspective view and FIG. 5B is a cross-sectional view taken along an imaginary plane P shown in FIG. 5A. FIG. 6 is a perspective view showing an example of a piping fixture used in the piping assembly kit of the present invention. 7A and 7B are diagrams showing the process of attaching the pipe to the pipe fixture by pushing the pipe into a pair of gripping portions of the pipe fixture to insert the pipe, in a construction method using the pipe assembly kit of the present invention. FIG. 7A shows the state before the pipe is inserted into the pipe fixture, and FIG. 7B shows the state after the pipe has been inserted into the pipe fixture.

Specific embodiments of the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present invention.

1. Regarding the pipe joint Figure 1 is a diagram that schematically shows the structure of a pipe joint according to an embodiment of the present invention, with Figure 1(a) being a longitudinal cross-sectional view along the cable insertion direction, and Figure 1(b) being a transverse cross-sectional view along a plane perpendicular to the cable insertion direction in Figure 1(a). Here, Figure 1(b) is a cross-sectional view taken along the a-a line of the cable in Figure 1(a). Figure 2 is an exploded perspective view showing the arrangement of each part when assembling a pipe joint according to an embodiment of the present invention.

As shown in Figure 1(a), the pipe fitting 1 connects the ends 21, 21 of multiple pipes 2, 2 through which a cable 3 is inserted. It comprises a cylindrical outer tube member 11 extending along the insertion direction D of the cable 3, a sliding member 12 attached to the end 21 of the pipe 2 and positioned within the outer tube member 11, and configured to slide in and out of the position of the open end 11a of the outer tube member 11 in response to thermal expansion and contraction of the pipe 2, and a retaining means 13 that prevents the sliding member 12 from falling off the outer tube member 11.

Here, a sliding member 12 is provided at the end 21 of the pipe 2, and is configured to slide in and out of the position of the open end 11a of the outer tubular member 11 in response to thermal expansion and contraction of the pipe 2. This allows the sliding member 12 to slide relative to the outer tubular member 11 in response to expansion and contraction of the pipe 2, allowing the pipe fitting 1 to absorb the thermal expansion and contraction of the pipe 2 and making it less likely that distortion will occur in the pipe 2 itself or in the connection between the pipe fitting 1 and the pipe 2 due to thermal expansion and contraction. Furthermore, by providing the pipe fitting 1 with a retaining means 13 that prevents the sliding member 12 from falling off the outer tubular member 11, the sliding range of the sliding member 12 can be restricted, thereby preventing the sliding member 12 from falling off the open end 11a of the outer tubular member 11 when an external force is applied to the pipe 2, for example. Therefore, even when using a resin pipe 2, this pipe fitting 1 makes it difficult for the pipe 2 itself or the connection part with the pipe 2 to be distorted due to thermal expansion and thermal contraction, and the end 21 of the pipe 2 is unlikely to fall off the pipe fitting 1. This makes it possible to provide a pipe fitting 1 and pipe assembly kit 10, as well as an installation method using the same.

The pipe fitting 1 according to this embodiment is configured to connect the ends 21 of multiple pipes 2 through which cables 3 are inserted, and includes at least an outer tubular member 11, a sliding member 12, and a retaining means 13. In Figures 1(a) and 1(b), the pipe fitting 1 is configured to connect the ends 21 of two pipes 2, but this is not limited to this, and the pipe fitting 1 may also be configured to connect the ends of three or more pipes. For example, the pipe fitting 1 may be configured so that the portions where the ends 21 of two pipes 2 are connected are arranged in parallel (not shown).

[Outer cylinder member]
The outer tube member 11 is a cylindrical member extending along the insertion direction D of the cable 3. The outer tube member 11 is disposed so that the cylindrical portion covers the cable 3 and the ends 21 of the two pipes 2, and serves to protect the portions of the cable 3 that are not covered by the two pipes 2.

The inner surface of the outer tube member 11 forms the inner surface of a tube extending along the insertion direction D of the cable 3, contacts the outer surface of the sliding member 12 (described below), and forms the sliding surface along which the sliding member 12 slides. As a result, the outer tube member 11 guides the position along which the sliding member 12 slides when the piping 2 expands or contracts, making it easier for the sliding member 12 to slide in and out of the position of the open end 11a of the outer tube member 11 (i.e., along the insertion direction D) in response to the expansion or contraction of the piping 2, reducing the likelihood of distortion in the piping or its connections.

Here, as described below, when the sliding member 12 has at least two first engagement portions 15a-15d each consisting of a convex portion, the outer tube member 11 preferably has an inner surface formed so that the first engagement portions 15a-15d engage with the second engagement portions 16a-16d each consisting of a concave portion extend along the insertion direction D. In this case, the second engagement portions 16a-16d each consisting of a concave portion of the outer tube member 11 preferably have grooves extending along the insertion direction D so as to continuously engage with the first engagement portions 15a-15d over a range that includes at least the sliding range of the sliding member 12. In this way, by engaging the second engagement portions 16a-16d of the outer tube member 11 with the first engagement portions 15a-15d of the sliding member 12, the sliding member 12 can be guided to a desired position on the outer tube member 11 even if the shape of the inner surface of the outer tube member 11 varies along the insertion direction D. In this case, the shape and size of the inner surface of the outer tube member 11 may be constant along the insertion direction D, or may vary.

The second engagement portions 16a-16d of the outer tube member 11 are preferably configured with the same number of recesses as the first engagement portions 15a-15d at positions where they engage with the first engagement portions 15a-15d of the sliding member 12. Note that Figure 1(b) shows an example in which four second engagement portions 16a-16d of the outer tube member 11 and four first engagement portions 15a-15d of the sliding member 12 are provided, but this is not limiting.

In the pipe fitting 1 according to this embodiment, the outer tubular member 11 preferably has a fixing means 17 for fixing it to the installation object. This prevents the outer tubular member 11 from following the end 21 of the piping 2 when the piping 2 expands or contracts, making it easier for the sliding member 12 to slide in and out of the position of the open end 11a of the outer tubular member 11.

Here, the fixing means 17 may be fixed to the installation object by screwing. For example, as shown in Figure 1(b), a mounting hole 17a made of a through hole may be provided at a position that does not intersect with the inner surface of the outer tubular member 11, and the outer tubular member 11 may be fixed by passing a screw through this mounting hole 17a and screwing it to the installation object.

The fixing means 17 may also have a flat installation surface 17b, which may include a protrusion (not shown) that engages with the installation object. By providing the installation surface 17b on the outer tubular member 11 in this way, the contact area between the outer tubular member 11 and the installation object increases, making it less likely that the outer tubular member 11 will follow the end 21 of the piping 2 when the piping 2 expands and contracts due to thermal expansion and contraction.

The outer tube member 11 preferably has multiple through holes 18 at positions offset from the insertion direction D of the cable 3 to drain water that has entered the internal space S of the outer tube member 11. This allows water to be drained from at least one of the through holes 18 even if it does enter the internal space S, thereby reducing the likelihood of deterioration of the cable 3 due to submersion. Furthermore, since submersion of the cable 3 can be reduced without the need for a waterproofing mechanism such as an O-ring adjacent to the internal space S, the sliding member 12 can be configured to slide in and out of the open end 11a of the outer tube member 11 with small forces due to thermal expansion and contraction of the piping 2. From the perspective of allowing outside air to enter the internal space S and efficiently draining water from the internal space S, the multiple through holes 18 are preferably positioned at different heights when installed on the installation object.

The cylindrical inner surface of the outer tube member 11 is preferably configured so that the central axis C of the tube is linear along the insertion direction D of the cable 3. This allows the sliding member 12, described below, to slide easily along the insertion direction D of the cable 3, making it less likely that distortion due to thermal expansion and contraction will occur in the piping itself or in the connection part with the piping.

The material of the outer tube member 11 is not particularly limited, but it is preferable that it be made of a highly rigid resin such as polyethylene in order to facilitate installation and prevent corrosion.

[Sliding member]
The sliding member 12 is attached to the end 21 of the pipe 2, is positioned within the outer tube member 11, and is configured to slide in and out of the position of the open end 11a of the outer tube member 11 in response to thermal expansion and contraction of the pipe 2. The sliding member 12 is disposed at the end 21 of the pipe 2 and slides along the cylindrical inner surface of the outer tube member 11. As a result, the sliding member 12 slides along the insertion direction D of the cable 3 in the direction of moving in and out of the position of the open end 11a of the outer tube member 11 in response to expansion and contraction of the pipe 2. Therefore, even if thermal expansion and contraction occur in the pipe 2, this does not affect the positioning of the cable 3, and distortion of the pipe 2 itself or the connection portion between the pipe fitting 1 and the pipe 2 is unlikely to occur.

The sliding member 12 is ring-shaped or cylindrical and extends along the insertion direction D of the cable 3, with its outer surface contacting the inner surface of the outer tube member 11. When the piping 2 expands or contracts, the sliding member 12's sliding position is guided by the outer tube member 11, and it slides along the insertion direction D in response to the expansion or contraction of the piping 2.

In this embodiment, the sliding member 12 is a ring-shaped member having an outer surface on which at least two first engagement portions 15a-15d consisting of convex portions are formed. Here, the inner surface of the outer tube member 11 preferably engages with the first engagement portions 15a-15d, respectively, and is formed with at least two second engagement portions 16a-16d consisting of concave portions that extend along the insertion direction D. By sliding the sliding member 12 with the first engagement portions 15a-15d and the second engagement portions 16a-16d engaged, rotation of the sliding member 12, particularly rotation about the insertion direction D, can be restricted.

If the outer tubular member 11 has two open ends 11a, the sliding member 12 is provided at one or both of the open ends 11a. Furthermore, if the outer tubular member 11 has three or more open ends 11a, some open ends 11a may not be provided with a sliding member 12. In particular, among the outer tubular members 11 located at the start or end of multiple pipes 2 connected by the pipe fitting 1, the open end 11a on the side to which the pipe 2 is not connected may not be provided with a sliding member 12.

The ring-shaped or cylindrical outer surface of the sliding member 12 is preferably configured so that its central axis C is linear along the insertion direction D of the cable 3, from the viewpoint of smoothing the sliding of the sliding member 12 due to thermal expansion and contraction and reducing the likelihood of distortion of the piping itself or the connection portion with the piping. From the same viewpoint, the outer surface of the sliding member 12 is preferably configured as a smooth flat or curved surface.

The material of the sliding member 12 is not particularly limited, but from the standpoint of ease of installation and corrosion prevention, it is preferable that it be made of a highly rigid resin such as polyethylene. Furthermore, from the standpoint of preventing unilateral wear of the inner surface of the outer tubular member 11 or the outer surface of the sliding member 12 due to the sliding of the sliding member 12, it is preferable that both the outer tubular member 11 and the sliding member 12 be made of the same material, and as an example, it is preferable that both be made of polyethylene.

A cable 3 is inserted into the cylindrical interior of the sliding member 12. The end 21 of the pipe 2 is connected directly or indirectly to the end of the sliding member 12 that exits the open end 11a of the outer cylindrical member 11 (outer side). Here, the end 21 of the pipe 2 can be connected to the sliding member 12 via a connector 14 provided on the end 21 of the pipe 2, as shown in FIG. 1(a), for example. In this case, the inner surface of the cylindrical sliding member 12 may be threaded so that the outer surface of the connector 14 can be threadedly engaged with the inner surface of the sliding member 12.

1(a) and 1(b) show an embodiment in which the outer surface of the sliding member 12 has at least two first engaging portions 15a-15d formed by convex portions, and the inner surface of the outer tubular member 11 has at least two second engaging portions 16a-16d formed by concave portions. However, the first engaging portions and second engaging portions may have different configurations. For example, as shown in the pipe fitting 1A in FIG. 3, the sliding member 12A may have an outer surface on which at least two first engaging portions 15a'-15d' formed by concave portions are formed, and the outer tubular member 11A may have an inner surface on which at least two second engaging portions 16a'-16d' formed by convex portions are formed so as to extend along the insertion direction D. In another embodiment, the first engaging portions may be a combination of engaging portions formed by convex portions and engaging portions formed by concave portions, as long as the second engaging portions are configured to engage with the first engaging portions.

[Prevention means]
The retaining means 13 is provided to prevent the sliding member 12 from falling off from the outer tubular member 11. This makes it possible to restrict the sliding range of the sliding member 12, and therefore to prevent the sliding member 12 from falling off from the open end 11 a of the outer tubular member 11 when, for example, an external force is applied to the pipe 2.

The retaining means 13 preferably uses a means for blocking or bending the sliding path of the sliding member 12 near the open end 11a of the outer tubular member 11. For example, if the sliding path of the sliding member 12 is blocked by blocking a portion of the open end 11a of the outer tubular member 11, a configuration can be used in which a portion of the sliding member 12 moves in and out through the portion of the open end 11a that is not blocked by the retaining means 13. In particular, from the perspective of reducing the overall size of the pipe fitting 1 by miniaturizing the retaining means 13, it is more preferable to use a means for blocking or bending the portion of the second engaging portions 16a to 16d of the outer tubular member 11 near the open end 11a as the retaining means 13.

As shown in Figures 1(a) and 1(b), the retaining means 13 may be formed as a separate member from the outer tubular member 11. Alternatively, to simplify assembly of the pipe fitting 1, a retaining means 13 formed by integral molding with the outer tubular member 11 may be used. For example, as shown in Figure 4, a retaining means 13B formed by the bent portions of the second engaging portions 16a-16d of the outer tubular member 11B may be provided near the open end 11a. In a pipe fitting 1B having this retaining means 13B, the first engaging portions 15a-15d of the sliding member 12 are engaged with the second engaging portions 16a-16d facing the open end 11a of the outer tubular member 11B. The pipe fitting 1B can be easily assembled by inserting the sliding member 12 into the outer tubular member 11B while rotating it to match the bend of the retaining means 13B, which is the bent portion of the second engaging portions 16a-16d.

2. Piping Assembly Kit The piping assembly kit of the present invention is a piping assembly kit having the above-described pipe fitting 1 , and includes a plurality of pipes 2 and a piping fixture 4 .

Of these, the pipes 2 are connected using pipe fittings 1, and include multiple pipes with outer surfaces 22 formed by alternatingly connecting ring-shaped recesses 22a and ring-shaped protrusions 22b, as shown in Figure 5.

The material of the pipe 2 is not particularly limited, but it is preferably made of a highly rigid resin such as polyethylene, from the standpoint of facilitating processing such as cutting and installation, and preventing corrosion. In particular, it is preferable that the pipe 2 be a cable protection tube made of polyethylene.

The pipe 2 has, from the inside out, at least an inner layer 23, an intermediate layer 24, and an outer layer 25. Preferably, one or both of the inner layer 23 and the intermediate layer 24 contain a flame retardant, and the outer layer 25 contains a weather-resistant agent. By including a flame retardant in one or both of the inner layer 23 and the intermediate layer 24, the cables inserted inside the pipe 2 can be protected from fires and other fires, even when the pipe 2 is made of resin. At the same time, the outer layer 25 contains a weather-resistant agent, making it less susceptible to resin degradation due to exposure to sunlight and other factors. In particular, using a metal powder such as aluminum powder as a weather-resistant agent creates a metallic appearance, thereby improving the reliability of the pipe 2 in terms of appearance.

6, the piping fixture 4 is made of an elastic material and has a bottom 41 with an attachment means 44, and a pair of gripping portions 42a, 42b that extend upright from both ends of the bottom 41 and have inner surfaces 43 shaped to correspond to the recessed and protruding portions 22a and 22b that make up the outer surface of the piping 2. This allows the bottom 41 of the piping fixture 4 to be attached to the installation object by the attachment means 44, and because the piping fixture 4 is made of an elastic material, it can hold the piping 2 between the pair of gripping portions 42a, 42b. Furthermore, the piping fixture 4 is configured so that the inner surfaces 43 of the gripping portions 42a, 42b fit into the recessed and protruding portions 22a and 22b on the outer surface 22 of the piping 2, respectively, thereby limiting movement of the piping 2 along the insertion direction D of the cable 3 at the inner surfaces 43 of the gripping portions 42a, 42b. Therefore, when thermal expansion and contraction occurs in the pipe 2, the portion of the pipe 2 whose movement is restricted by the pipe fixing device 4 acts as a fulcrum, allowing the sliding force of the sliding member 12 to act on the pipe fitting 1. As a result, the number of points where the pipe 2 is supported by the pipe fixing device 4 is reduced, and even if one pipe 2 is supported by one pipe fixing device 4, for example, distortion of the pipe is less likely to occur.

All of the piping assembly kits of the present invention can be constructed from lightweight materials such as polyethylene, and the piping 2 can be easily secured to the piping fixture 4 by simply clamping it between the pair of gripping portions 42a, 42b. Therefore, the piping assembly kit of the present invention can shorten the time required to attach the piping 2 to the installation object.

3. Regarding the Installation Method Using the Pipe Assembly Kit An installation method using the pipe assembly kit of the present invention is an installation method using the above-mentioned pipe assembly kit 10, and one example thereof can be a method including the steps of fixing the outer tubular member 11 of the pipe fitting 1 and the pipe fixing device 4 to an installation object, connecting the sliding member 12 to the end 21 of the pipe 2, inserting the sliding member 12, to which the pipe 2 is connected, into the outer tubular member 11 fixed to the installation object, and inserting the pipe 2 connected to the outer tubular member 11 by pressing the pipe 2 between the pair of gripping portions 42 a, 42 b of the pipe fixing device 4, and fitting the inner surfaces 43 of the gripping portions 42 a, 42 b into the recessed portion 22 a and the protruding portion 22 b on the outer surface 22 of the pipe 2.

In the process of fixing the outer tubular member 11 of the pipe fitting 1 and the piping fixture 4 to the installation object, a screw is passed through the mounting hole 17a provided in the outer tubular member 11 of the pipe fitting 1 to screw the outer tubular member 11 to the installation object. At the same time, a screw is passed through the through-hole, which serves as the mounting means 44 provided in the bottom 41 of the piping fixture 4, to screw the piping fixture 4 to the installation object. This determines the placement of each component that makes up the piping assembly kit on the installation object.

Furthermore, in the process of connecting the sliding member 12 to the end 21 of the pipe 2, the sliding member 12 can be connected directly or indirectly to the end 21 of the pipe 2. Here, the end 21 of the pipe 2 may be indirectly connected to the sliding member 12 by providing a connector 14 at the end 21 of the pipe 2 and threading the outer surface of this connector 14 onto the inner surface of the sliding member 12, as shown in FIG. 1(a), for example.

The process of inserting the sliding member 12, to which the piping 2 is connected, into the outer tubular member 11 fixed to the installation object can be performed by engaging the first engagement portions 15a-15d of the sliding member 12 with the second engagement portions 16a-16d facing the open end 11a of the outer tubular member 11, and then inserting these engaged portions into the outer tubular member 11.

Here, if the outer tubular member 11 or sliding member 12 does not have a retaining means 13, it is preferable to carry out a step of attaching a retaining means 13 to the outer tubular member 11 into which the sliding member 12 is inserted. This prevents the sliding member 12 from falling off the open end 11a of the outer tubular member 11 when an external force is applied to the piping 2, thereby preventing the sliding member 12 from falling off when the piping 2 is installed.

The pipe 2 connected to the outer tubular member 11 can be attached to the pipe fixing device 4 by inserting the pipe 2 between the pair of gripping portions 42a, 42b of the pipe fixing device 4 and fitting the inner surfaces 43 of the gripping portions 42a, 42b into the recessed portions 22a and protruding portions 22b on the outer surface 22 of the pipe 2. For example, when the pipe 2 shown in Figure 7(a) is installed in the pipe fixing device 4, the positional relationship between the pipe 2 and the pipe fixing device 4 is as shown in Figure 7(b).

The installation method using the pipe assembly kit of the present invention uses a pipe assembly kit made of a lightweight material such as polyethylene, which makes it easy to perform processes such as cutting and installation. Furthermore, the pipe 2 can be easily secured to the pipe fixing device 4 by simply clamping it between the pair of gripping portions 42a, 42b of the pipe fixing device 4, allowing the empty pipe with the cable 3 inserted inside to be installed on the target object in a shorter amount of time.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and includes all aspects encompassed by the concept of the present invention and the scope of the claims, and various modifications can be made within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Pipe joint 11, 11A, 11B Outer tubular member 11a Open end of outer tubular member 12, 12A Sliding member 13, 13B Anti-slip means 14 Connector 15a to 15d, 15a' to 15d' First engaging portion 16a to 16d, 16a' to 16d' Second engaging portion 17 Fixing means 17a Mounting hole 17b Installation surface 18 Through hole 2 Pipe 21 End of pipe 22 Outer surface of pipe 22a Concave portion 22b Convex portion 23 Inner layer 24 Intermediate layer 25 Outer layer 3 Cable 4 Pipe fixing tool 41 Bottom portion 42a, 42b Grip portion 43 Inner surface of grip portion 44 Mounting means C Central axis of outer tubular member D Cable insertion direction S Internal space of the outer cylinder member

Claims (7)

A pipe joint for connecting the ends of a plurality of pipes through which cables are inserted,
a cylindrical outer tube member extending along the cable insertion direction;
a sliding member attached to an end of the pipe, positioned within the outer tubular member, and configured to slide in and out of an open end position of the outer tubular member in response to thermal expansion and contraction of the pipe;
a retaining means for preventing the sliding member from falling off from the outer cylindrical member;
and
The outer tube member has a plurality of through holes at positions offset in the cable insertion direction, for discharging water that has entered the internal space of the outer tube member . The pipe fitting according to claim 1, wherein the outer tubular member has a fixing means for fixing it to an object to be installed. the sliding member is a ring-shaped member having an outer surface on which at least two first engagement portions each consisting of a convex portion or a concave portion are formed,
the outer cylindrical member has an inner surface on which at least two second engaging portions, each of which is formed as a recess or a protrusion and engages with the first engaging portion, extend along the insertion direction;
2. The pipe joint according to claim 1, wherein the sliding member is slidable in an engaged state between the first engaging portion and the second engaging portion, thereby restricting rotation of the sliding member. A pipe joint that connects the ends of multiple pipes through which cables are inserted,
a cylindrical outer tube member extending along the cable insertion direction;
a sliding member attached to an end of the pipe, positioned within the outer tubular member, and configured to slide in and out of an open end position of the outer tubular member in response to thermal expansion and contraction of the pipe;
A retaining means for preventing the sliding member from falling off from the outer cylindrical member.
Pipe fitting having
and ,
a plurality of pipes connected by the pipe joints, each having an outer surface formed by alternately connecting ring-shaped recesses and ring-shaped protrusions;
A piping assembly kit comprising: a bottom portion made of an elastic material and having an attachment means; and a piping fixture having a pair of gripping portions extending upright from both ends of the bottom portion and having inner surfaces shaped to correspond to the concave and convex portions that constitute the outer surface of the piping. 5. The piping assembly kit according to claim 4 , wherein the piping is a cable protection tube made of polyethylene. The pipe has, in order from the inside, at least an inner layer, an intermediate layer, and an outer layer,
one or both of the inner layer and the intermediate layer contains a flame retardant;
The piping assembly kit according to claim 4 , wherein the outer layer contains a weathering agent. A construction method using the piping assembly kit according to claim 4 ,
a step of fixing the outer tubular member of the pipe joint and the piping fixing tool to an object to be installed;
connecting the sliding member to an end of the pipe;
inserting the sliding member, to which the piping is connected, into an outer tubular member fixed to the installation object;
an installation method comprising the steps of inserting a pipe connected to the outer tube member by pushing the pipe into a pair of gripping portions of the pipe fixing device, and engaging the inner surfaces of the gripping portions with the concave and convex portions on the outer surface of the pipe.