Pipe joint structure and support column

Abstract

To provide a pipe joint structure capable of easily joining both pipe bodies while suppressing bending between the pipe bodies, and a support column adopting the pipe joint structure.SOLUTION: A first flange 8 extending outward in a radial direction is formed at a position in a pipe axial direction where a length L in the pipe axial direction of a swallowing margin to a socket of a receiving side pipe body 7 of a spigot of a spigot side pipe body 2 becomes a predetermined length, and a second flange 9 extending outward in the radial direction is formed at a socket end of the receiving side pipe body 7, in a pipe joint structure 1, the first flange 8 and a second flange 9 abut on each other in the pipe axial direction, and a fitting part 12 for fitting both flanges 8 and 9 is formed in the first flange 8 and the second flange 9, and a support column adopts this pipe joint structure 1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pipe joint structure and a support column employing this pipe joint structure. [Background technology]

[0002] As shown in Patent Document 1 below, for example, a configuration is known for lighting poles installed on the side of roads such as streets and highways, and poles for installing road signs, in which a bolt 22 is embedded in a concrete base 18 formed on the ground, and a flange portion 20a formed on a pole 10 is fixed with the bolt 22 and a nut 23 (see Patent Document 1, especially paragraphs 0019 to 0021 and Figure 1).

[0003] Ductile cast iron pipes are joined using a joint in which the spigot of the spigot-side pipe is inserted into the socket of the receiving pipe. A rubber ring is installed in the gap between the inner surface of the socket and the outer surface of the socket, allowing bending at a predetermined angle between the two pipes. If bending would be inconvenient, for example, as shown in Patent Document 2 below, bending between the pipes 1 and 3 can be prevented by bringing the spigot tapered surface 5 at the tip of the socket 4 into contact with the socket tapered surface 6, and by pressing the spigot 4 radially with anti-bending bolts 17 arranged circumferentially on an anti-bending ring 14 fixed to the opening of the socket 2 (see Patent Document 2, particularly, page 4, line 11 to page 6, line 20, and Figure 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7357374 [Patent Document 2] Japanese Utility Model Application Publication No. 2-16895 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration disclosed in Patent Document 1, one end of the bolt 22 is exposed to different environments, that is, in the concrete foundation 18 and the other end is exposed to the air, making it prone to concrete macrocell corrosion and necessitating early replacement of the bolt 22 and other corrosion prevention measures. Furthermore, the configuration disclosed in Patent Document 2 has the problem of requiring time and effort to install the bend prevention ring 14.

[0006] Therefore, an object of the present invention is to provide a pipe joint structure that can easily join two pipe bodies while suppressing bending between the pipe bodies, and a support column that employs this pipe joint structure. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides: In a pipe joint structure in which an insertion port of an insertion-side pipe body is inserted into a receiving port of a receiving-side pipe body to join the two pipe bodies, A pipe fitting structure (first configuration) is constructed, characterized in that a first flange extending radially outward is formed at a pipe axis position where the pipe axis length of the insertion port's insertion gap into the receiving port is a predetermined length, and a second flange extending radially outward is formed at the receiving port end of the receiving side pipe body, the first flange and the second flange abutting in the pipe axis direction, and the first flange and the second flange are formed with fitting portions for fitting the two flanges together.

[0008] In this way, the two pipes can be easily joined without using bolts, by abutting the flanges formed on each pipe and fitting the mating portions formed on both flanges together, while suppressing bending between the pipes.

[0009] In the first configuration, the fitting portion may have a protrusion formed on one side of the first flange or the second flange, and a fitting hole formed on the other side of the first flange or the second flange into which the protrusion fits (second configuration). This more reliably prevents bending between the pipes and also prevents the two pipes from rotating relative to each other around the pipe axis.

[0010] The second configuration can be configured (third configuration) to include a sealing member that closes the gap between the protrusion and the fitting hole. This can further suppress bending between the pipe bodies and prevent foreign matter such as sand from accumulating in the gap, which could interfere with dismantling the pipe joint, or rainwater from entering and causing corrosion.

[0011] In the first to third configurations, a rubber ring may be provided in a circumferential groove formed on the inner surface of the receiving opening of the receiving tube, and one of the tubes may support the other via the rubber ring (fourth configuration). In this way, the rubber ring provides a centering effect when inserting the inserting tube into the receiving tube, allowing for smooth insertion, and the rubber ring fills the gap between the two tubes, further suppressing bending between the tubes.

[0012] In the first to fourth configurations, the length of the gap in the axial direction of the pipe can be set to a range of two to four times the nominal diameter of the insertion-side pipe body (fifth configuration). In this way, the tip of the insertion port abuts against the inner surface of the receiving port, thereby further suppressing bending between the pipe bodies.

[0013] In the first to fifth configurations, a sixth configuration (configuration) can be adopted in which the difference between the outer diameter of the insertion port of the insertion-side tube body and the inner diameter of the socket of the receiving-side tube body is smaller at both ends in the axial direction than at the center in the axial direction. In this way, it is only necessary to increase the dimensional accuracy of the inner diameter of the socket and the outer diameter of the insertion port only at both ends in the axial direction, thereby reducing the difficulty of processing.

[0014] The pipe joint structures according to the first to sixth configurations can be used in a manner such that one of the insertion side pipe body or the receiving side pipe body is buried in a concrete base, and the other of the insertion side pipe body or the receiving side pipe body is attached to a support pillar erected from the concrete base. [Effects of the Invention]

[0015] In this invention, the pipe joint structure and support are configured so that a first flange is formed at a pipe axis position where the pipe axis length of the insertion port of the insertion side pipe body that fits into the receiving port of the receiving side pipe body is a predetermined length, and a second flange is formed at the receiving port end of the receiving side pipe body that extends radially outward, the first flange and the second flange abut in the pipe axis direction, and the first flange and the second flange are formed with fitting portions for fitting the two flanges together.Therefore, by the abutment of the flanges formed on both pipe bodies and the fitting of the fitting portions formed on both flanges, the two pipe bodies can be easily joined while suppressing bending between the pipe bodies without using bolts. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view showing a first embodiment of a support column employing a pipe joint structure according to the present invention; [Figure 2] Cross-sectional view showing the main part of Figure 1 [Figure 3] 2A and 2B are cross-sectional views showing the fitting portion of the pipe joint structure shown in FIG. 1, in which (a) is a protrusion formed on the first flange side, and (b) is a fitting hole formed on the second flange side. [Figure 4] 1. It is a sectional view which shows another example of the fitting part of the pipe joint structure shown in FIG. 1, (a) before attachment of the protective cap, (b) after attachment of the protective cap. [Figure 5] FIG. 2 is a cross-sectional view showing another example of the fitting portion of the pipe joint structure shown in FIG. 1. [Figure 6] 5A is a cross-sectional view showing another example of the fitting portion shown in FIG. 2, and FIG. 5B is a cross-sectional view showing another example of the fitting portion shown in FIG. 5. [Figure 7] FIG. 10 is a cross-sectional view showing a main part of a second embodiment of a support column employing the pipe joint structure according to the present invention; [Figure 8] 8 is a cross-sectional view showing a main part of another example of the support column shown in FIG. 7. [Figure 9] A cross-sectional view showing the state in which fixing holes for installing the inserting pipe body are formed in the concrete base. DETAILED DESCRIPTION OF THE INVENTION

[0017] A first embodiment of a pipe joint structure 1 according to the present invention will be described with reference to the drawings. Fig. 1 shows an example of application of this pipe joint structure 1 to a lighting pole. The lower part of this pole (an insertion pipe body 2, described later) is vertically buried in a concrete base 3, which is formed by placing the lower part in the ground and then pouring concrete around it. A lighting base 4 is provided on the upper part of this pole, and a lighting device 5 is installed on this lighting base 4. A cable protection tube 6 is provided inside the pipe joint structure 1 and the concrete base 3, and a cable (not shown) for transmitting power to the lighting device 5 is routed inside this cable protection tube 6.

[0018] As shown in Figure 2, the support employs a pipe joint structure 1 in which the insertion port of the insertion-side pipe 2 is inserted into the reception port of the reception-side pipe 7 to join the two pipes 2, 7. The insertion-side pipe 2 and the reception-side pipe 7 employed in this embodiment are both cast iron pipes. Hereinafter, the extension direction of the two pipes 2, 7 will be referred to as the pipe axis direction, the direction perpendicular to the pipe axis direction will be referred to as the radial direction, and the direction along the arc centered on the pipe axis will be referred to as the circumferential direction.

[0019] A first flange 8 extending radially outward is formed around the entire circumferential direction at the insertion opening of the insertion-side tube 2 at a tube axial position where the axial length L of the insertion allowance into the receiving opening of the receiving-side tube 7 is a predetermined length. The axial end face of the first flange 8 (the surface facing the second flange 9, described later, when the two tubes 2, 7 are joined) is a flat surface with the tube axial direction as its surface normal. As shown in Figure 3(a), the first flange 8 is formed with protrusions 10 at predetermined angular intervals (180-degree intervals in this embodiment) in the circumferential direction, which extend in the tube axial direction toward the second flange 9 when the two tubes 2, 7 are joined.

[0020] A second flange 9 extending radially outward is formed around the entire circumferential circumference of the receiving end of the receiving-side tube 7. The axial end face of the second flange 9 (the face facing the first flange 8 when the two tubes 2, 7 are joined) is a plane with the tube axial direction as its surface normal. As shown in FIG. 3(b), the second flange 9 is formed with two mating holes 11 that penetrate the second flange 9 in the tube axial direction, spaced at the specified angular interval (180-degree interval) in the circumferential direction. The projections 10 formed on the first flange 8 and the mating holes 11 formed on the second flange 9 form a mating portion 12. The number of projections 10 and mating holes 11 is not limited to two and can be changed as appropriate.

[0021] When the two pipe bodies 2, 7 are joined, the axial end faces of the first flange 8 and the second flange 9 are in surface contact with each other, with the protrusion 10 fitted into the mating hole 11, so that the receiving side pipe body 7 joined to the inserting side pipe body 2 buried vertically in the concrete base 3 is also held vertically relative to the concrete base 3.

[0022] A circumferential groove 13 is formed on the inner surface of the receiving port of the receiving side pipe 7, and a rubber ring 14 is provided in this circumferential groove 13. In this embodiment, a T-shaped rubber ring for a general joint is used as the rubber ring 14, but since watertightness is not required for this support (pipe joint structure 1), a rubber ring 14 with a simple shape such as an O-ring can also be used. Furthermore, an elastic body having properties equivalent to those of rubber can also be used as the material.

[0023] The length L in the pipe axis direction of the insertion opening of the insertion-side pipe 2 that extends into the receiving opening of the receiving-side pipe 7 is approximately 2.5 times the nominal diameter D of the insertion-side pipe 2. The ratio (L / D) of the length L in the pipe axis direction of the extension to the nominal diameter D is preferably within a range of 2 to 4 times, and more preferably within a range of 2.1 to 3.5 times.

[0024] The above-mentioned pipe joint structure 1 and support are configured to join the two pipe bodies 2, 7 by abutting the flanges 8, 9 formed on both pipe bodies 2, 7 respectively and by fitting the fitting portions 12 formed on both flanges 8, 9 together. Therefore, the two pipe bodies 2, 7 can be easily joined while suppressing bending between the pipe bodies 2, 7 without using bolts.

[0025] Furthermore, the above-mentioned pipe joint structure 1 and support are configured such that the fitting portion 12 has a protrusion 10 formed on the first flange 8 and a fitting hole 11 formed on the second flange 9 into which the protrusion 10 fits, thereby more reliably suppressing bending between the pipe bodies 2, 7 and suppressing relative rotation of the two pipe bodies 2, 7 around the pipe axis.

[0026] Furthermore, the above-mentioned pipe joint structure 1 and support are configured such that a rubber ring 14 is provided in a circumferential groove 13 formed on the inner surface of the receiving-side pipe 7, and the insertion-side pipe 2 supports the receiving-side pipe 7 via the rubber ring 14. Therefore, when the insertion-side pipe 2 is inserted into the receiving-side pipe 7, the centering action of the rubber ring 14 is exerted, allowing for smooth insertion, and the rubber ring 14 fills the gap between the two pipes 2, 7, further suppressing bending between the pipes 2, 7. Note that instead of providing the rubber ring 14, a tapered surface can be formed on the insertion opening of the insertion-side pipe 2 and the receiving opening of the receiving-side pipe 7, thereby making it possible to configure the pipes to be easily centered when joined.

[0027] Furthermore, the above-mentioned pipe joint structure 1 and support pillar have an axial length L of the swallowing allowance that is approximately 2.5 times the nominal diameter D of the insertion side pipe body 2, which is within the range of 2 to 4 times. Therefore, the tip of the insertion port abuts against the inner surface of the receiving port, thereby further suppressing bending between the pipe bodies 2 and 7.

[0028] In the above embodiment, as shown in Figures 4(a) and 4(b), the gap between the outer surface of the protrusion 10 and the inner surface of the fitting hole 11 can be closed with a covered cylindrical protective cap that acts as a sealing member 15. By closing the gap in this way, bending between the pipe bodies 2 and 7 can be further suppressed, and it is also possible to prevent foreign matter such as sand from accumulating in the gap, which could interfere with dismantling the pipe joint structure 1, and to prevent rainwater from entering and causing corrosion. Note that a liquid sealant that hardens over time after being injected into the gap can also be used as the sealing member 15.

[0029] 5, the fitting portion 12 can also be configured to have a protrusion 10 formed on the first flange 8 and a bottomed recess 16 formed on the second flange 9 that opens toward the protrusion 10. In this configuration, it is possible to prevent foreign matter from accumulating between the outer surface of the protrusion 10 and the inner surface of the bottomed recess 16 and to prevent rainwater from entering, without using a sealing member 15. Even in this configuration, a sealing member 15 can be further provided in the gap between the protrusion 10 and the bottomed recess 16. In this configuration, bending between the pipes 2 and 7 can be further suppressed.

[0030] In the above, the protrusion 10 is formed on the first flange 8, and the fitting hole 11 or the bottomed recess 16 is formed on the second flange 9, but as shown in Figures 6(a) and 6(b), the same effect as above can be achieved even if the fitting hole 11 or the bottomed recess 16 is formed on the first flange 8, and the protrusion 10 is formed on the second flange 9.

[0031] A second embodiment of the pipe joint structure 1 according to the present invention is shown in Figure 7. The pipe joint structure 1 according to the second embodiment has the same basic configuration as the pipe joint structure 1 according to the first embodiment, but differs in that the difference between the outer diameter of the insertion port of the insertion-side pipe 2 and the inner diameter of the socket of the receiving-side pipe 7 (the size of the gap between the socket and the insertion port) is smaller at both ends in the axial direction of the pipe than at the center in the axial direction.

[0032] In general, it is difficult to ensure dimensional accuracy with cast iron pipes, and it is difficult to control the size of the gap between the outer surface of the spigot and the inner surface of the socket to a predetermined value or less throughout the entire axial direction of the spigot and the socket. This can result in a gap between the outer surface of the spigot and the inner surface of the socket, causing the spigot-side pipe body 2 and the receiving-side pipe body 7 to tilt relative to each other. Therefore, by reducing the size of the gap between the spigot and the socket only at both ends in the axial direction, as in the second embodiment, it is only necessary to increase the dimensional accuracy of the processing of the inner diameter of the socket and the outer diameter of the socket only at both ends in the axial direction, thereby reducing the difficulty of processing.

[0033] In the configuration shown in Fig. 7, the outer diameter of the insertion port is constant, but even if the outer diameter of the insertion port is changed in the axial direction of the tube as shown in Fig. 8, the same effect as the configuration in Fig. 7 can be obtained. In this case, by forming a tapered section 17 in which the outer diameter gradually increases from the tip of the insertion port toward the first flange 8, the insertion-side tube body 2 can be easily inserted into the receiving-side tube body 7.

[0034] In each of the above-described embodiments, the lower part of the support (insertion-side pipe 2) is vertically embedded in a concrete base 3 formed in the ground. Therefore, while the upper part of the support (receiving-side pipe 7) can be replaced as it deteriorates over time, the lower part of the support (insertion-side pipe 2) cannot be replaced without destroying the concrete base 3. Therefore, as shown in FIG. 9 , a form corresponding to the shape of the lower part of the support (insertion-side pipe 2) can be installed in the ground, concrete can be poured around the form, and after the concrete hardens, the form can be removed to form a fixing hole 18 in the concrete base 3 into which the lower part of the support (insertion-side pipe 2) can be fitted. In this way, when the lower part of the support (insertion-side pipe 2) fitted into the fixing hole 18 deteriorates over time, the lower part of the support (insertion-side pipe 2) can be easily replaced, thereby extending the life of the support as a whole.

[0035] In each of the above embodiments, the concrete base 3 can be formed so as to protrude above the ground, with only its lower part buried in the ground, or placed directly on the ground.

[0036] Furthermore, in each of the above-described embodiments, the entire first flange 8 (portion extending radially outward) is configured to be embedded in the concrete base 3, but it is also possible to configure the first flange 8 to be installed on the upper surface of the concrete base 3 with only the straight pipe portion of the insertion-side pipe body 2 embedded in the concrete base 3. In this way, when the concrete base 3 is formed in advance, for example as shown in Figure 9, it is only necessary to form a cylindrical hole into which the straight pipe portion of the insertion-side pipe body 2 is inserted, thereby improving workability.

[0037] The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. Therefore, the scope of the present invention is defined by the claims, not by the above description, and is intended to include the meaning equivalent to the claims and all modifications thereof. [Explanation of symbols]

[0038] 1 Pipe joint structure 2 Insertion tube 3 Concrete base 4 Lighting base 5. Lighting equipment 6 Cable protection tube 7 Receiving tube 8 First flange 9 Second flange 10 Protrusion 11 Mating hole 12 Fitting part 13 Circumferential groove 14 Rubber Rings 15 Sealing member 16 Bottomed recess 17 Tapered section 18 fixing hole L Length of the gap in the pipe axial direction D Nominal diameter of the insertion pipe

Claims

1. A pipe joint structure in which the insertion port of an insertion-side pipe body (2) is inserted into the receiving port of a receiving-side pipe body (7) to join the two pipe bodies (2, 7), A pipe fitting structure characterized in that a first flange (8) extending radially outward is formed at a pipe axis position where the pipe axis length (L) of the insertion port's insertion into the receiving port is a predetermined length, and a second flange (9) extending radially outward is formed at the receiving port end of the receiving side pipe body (7), the first flange (8) and the second flange (9) abut in the pipe axis direction, and fitting portions (12) are formed in the first flange (8) and the second flange (9) to fit together the two flanges (8, 9).

2. 2. The pipe joint structure according to claim 1, wherein the fitting portion (12) has a protrusion (10) formed on one side of the first flange (8) or the second flange (9), and a fitting hole (11) formed on the other side of the first flange (8) or the second flange (9) into which the protrusion (10) fits.

3. 3. The pipe joint structure according to claim 2, further comprising a sealing member (15) that closes a gap between the protrusion (10) and the fitting hole (11).

4. 2. A pipe joint structure according to claim 1, wherein a rubber ring (14) is provided in a circumferential groove (13) formed on the inner surface of the receiving opening of the receiving side pipe (7), and one of the pipes (2, 7) supports the other pipe (2, 7) via the rubber ring (14).

5. 2. The pipe joint structure according to claim 1, wherein the length (L) of the swallowing margin in the pipe axial direction is within a range of two to four times the nominal diameter (D) of the insertion side pipe body (2).

6. 2. A pipe fitting structure according to claim 1, wherein the difference between the outer diameter of the insertion opening of the insertion side pipe body (2) and the inner diameter of the receiving opening of the receiving side pipe body (7) is smaller at both ends in the pipe axis direction than at the center in the pipe axis direction.

7. A support pillar employing a pipe joint structure according to any one of claims 1 to 6, wherein one of the insertion side pipe body (2) or the receiving side pipe body (7) is buried in a concrete base (3), and the other of the insertion side pipe body (2) or the receiving side pipe body (7) is erected from the concrete base (3).

Images